head 1.4; access; symbols netbsd-11-0-RELEASE:1.3 netbsd-11-0-RC7:1.3 netbsd-11-0-RC6:1.3 netbsd-11-0-RC5:1.3 netbsd-11-0-RC4:1.3 netbsd-11-0-RC3:1.3 netbsd-11-0-RC2:1.3 netbsd-11-0-RC1:1.3 perseant-exfatfs-base-20250801:1.3 netbsd-11:1.3.0.2 netbsd-11-base:1.3; locks; strict; comment @# @; 1.4 date 2025.08.27.23.52.30; author christos; state Exp; branches; next 1.3; commitid WC24MHlsaVjzxq8G; 1.3 date 2024.08.27.17.10.36; author christos; state Exp; branches; next 1.2; commitid mDtya9zLCs0g3unF; 1.2 date 2024.08.27.17.07.03; author christos; state Exp; branches; next 1.1; commitid iTMpb5UIkvcW1unF; 1.1 date 2024.08.18.03.52.40; author rin; state Exp; branches; next ; commitid xNJry68WCd1eVfmF; desc @@ 1.4 log @regen and fix the build for amd64 @ text @This is gdb.info, produced by makeinfo version 4.8 from /usr/src/tools/gdb/../../external/gpl3/gdb/dist/gdb/doc/gdb.texinfo. INFO-DIR-SECTION Software development START-INFO-DIR-ENTRY * Gdb: (gdb). The GNU debugger. * gdbserver: (gdb) Server. The GNU debugging server. END-INFO-DIR-ENTRY Copyright (C) 1988-2024 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "Free Software" and "Free Software Needs Free Documentation", with the Front-Cover Texts being "A GNU Manual," and with the Back-Cover Texts as in (a) below. (a) The FSF's Back-Cover Text is: "You are free to copy and modify this GNU Manual. Buying copies from GNU Press supports the FSF in developing GNU and promoting software freedom." This file documents the GNU debugger GDB. This is the Tenth Edition, of `Debugging with GDB: the GNU Source-Level Debugger' for GDB (GDB) Version 15.1. Copyright (C) 1988-2024 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "Free Software" and "Free Software Needs Free Documentation", with the Front-Cover Texts being "A GNU Manual," and with the Back-Cover Texts as in (a) below. (a) The FSF's Back-Cover Text is: "You are free to copy and modify this GNU Manual. Buying copies from GNU Press supports the FSF in developing GNU and promoting software freedom."  File: gdb.info, Node: Top, Next: Summary Debugging with GDB ****************** This file describes GDB, the GNU symbolic debugger. This is the Tenth Edition, for GDB (GDB) Version 15.1. Copyright (C) 1988-2024 Free Software Foundation, Inc. This edition of the GDB manual is dedicated to the memory of Fred Fish. Fred was a long-standing contributor to GDB and to Free software in general. We will miss him. * Menu: * Summary:: Summary of GDB * Sample Session:: A sample GDB session * Invocation:: Getting in and out of GDB * Commands:: GDB commands * Running:: Running programs under GDB * Stopping:: Stopping and continuing * Reverse Execution:: Running programs backward * Process Record and Replay:: Recording inferior's execution and replaying it * Stack:: Examining the stack * Source:: Examining source files * Data:: Examining data * Optimized Code:: Debugging optimized code * Macros:: Preprocessor Macros * Tracepoints:: Debugging remote targets non-intrusively * Overlays:: Debugging programs that use overlays * Languages:: Using GDB with different languages * Symbols:: Examining the symbol table * Altering:: Altering execution * GDB Files:: GDB files * Targets:: Specifying a debugging target * Remote Debugging:: Debugging remote programs * Configurations:: Configuration-specific information * Controlling GDB:: Controlling GDB * Extending GDB:: Extending GDB * Interpreters:: Command Interpreters * TUI:: GDB Text User Interface * Emacs:: Using GDB under GNU Emacs * GDB/MI:: GDB's Machine Interface. * Annotations:: GDB's annotation interface. * Debugger Adapter Protocol:: The Debugger Adapter Protocol. * JIT Interface:: Using the JIT debugging interface. * In-Process Agent:: In-Process Agent * GDB Bugs:: Reporting bugs in GDB * Command Line Editing:: Command Line Editing * Using History Interactively:: Using History Interactively * In Memoriam:: In Memoriam * Formatting Documentation:: How to format and print GDB documentation * Installing GDB:: Installing GDB * Maintenance Commands:: Maintenance Commands * Remote Protocol:: GDB Remote Serial Protocol * Agent Expressions:: The GDB Agent Expression Mechanism * Target Descriptions:: How targets can describe themselves to GDB * Operating System Information:: Getting additional information from the operating system * Trace File Format:: GDB trace file format * Index Section Format:: .gdb_index section format * Debuginfod:: Download debugging resources with `debuginfod' * Man Pages:: Manual pages * Copying:: GNU General Public License says how you can copy and share GDB * GNU Free Documentation License:: The license for this documentation * Concept Index:: Index of GDB concepts * Command and Variable Index:: Index of GDB commands, variables, functions, and Python data types  File: gdb.info, Node: Summary, Next: Sample Session, Prev: Top, Up: Top Summary of GDB ************** The purpose of a debugger such as GDB is to allow you to see what is going on "inside" another program while it executes--or what another program was doing at the moment it crashed. GDB can do four main kinds of things (plus other things in support of these) to help you catch bugs in the act: * Start your program, specifying anything that might affect its behavior. * Make your program stop on specified conditions. * Examine what has happened, when your program has stopped. * Change things in your program, so you can experiment with correcting the effects of one bug and go on to learn about another. You can use GDB to debug programs written in C and C++. For more information, see *Note Supported Languages: Supported Languages. For more information, see *Note C and C++: C. Support for D is partial. For information on D, see *Note D: D. Support for Modula-2 is partial. For information on Modula-2, see *Note Modula-2: Modula-2. Support for OpenCL C is partial. For information on OpenCL C, see *Note OpenCL C: OpenCL C. Debugging Pascal programs which use sets, subranges, file variables, or nested functions does not currently work. GDB does not support entering expressions, printing values, or similar features using Pascal syntax. GDB can be used to debug programs written in Fortran, although it may be necessary to refer to some variables with a trailing underscore. GDB can be used to debug programs written in Objective-C, using either the Apple/NeXT or the GNU Objective-C runtime. * Menu: * Free Software:: Freely redistributable software * Free Documentation:: Free Software Needs Free Documentation * Contributors:: Contributors to GDB  File: gdb.info, Node: Free Software, Next: Free Documentation, Up: Summary Free Software ============= GDB is "free software", protected by the GNU General Public License (GPL). The GPL gives you the freedom to copy or adapt a licensed program--but every person getting a copy also gets with it the freedom to modify that copy (which means that they must get access to the source code), and the freedom to distribute further copies. Typical software companies use copyrights to limit your freedoms; the Free Software Foundation uses the GPL to preserve these freedoms. Fundamentally, the General Public License is a license which says that you have these freedoms and that you cannot take these freedoms away from anyone else.  File: gdb.info, Node: Free Documentation, Next: Contributors, Prev: Free Software, Up: Summary Free Software Needs Free Documentation ====================================== The biggest deficiency in the free software community today is not in the software--it is the lack of good free documentation that we can include with the free software. Many of our most important programs do not come with free reference manuals and free introductory texts. Documentation is an essential part of any software package; when an important free software package does not come with a free manual and a free tutorial, that is a major gap. We have many such gaps today. Consider Perl, for instance. The tutorial manuals that people normally use are non-free. How did this come about? Because the authors of those manuals published them with restrictive terms--no copying, no modification, source files not available--which exclude them from the free software world. That wasn't the first time this sort of thing happened, and it was far from the last. Many times we have heard a GNU user eagerly describe a manual that he is writing, his intended contribution to the community, only to learn that he had ruined everything by signing a publication contract to make it non-free. Free documentation, like free software, is a matter of freedom, not price. The problem with the non-free manual is not that publishers charge a price for printed copies--that in itself is fine. (The Free Software Foundation sells printed copies of manuals, too.) The problem is the restrictions on the use of the manual. Free manuals are available in source code form, and give you permission to copy and modify. Non-free manuals do not allow this. The criteria of freedom for a free manual are roughly the same as for free software. Redistribution (including the normal kinds of commercial redistribution) must be permitted, so that the manual can accompany every copy of the program, both on-line and on paper. Permission for modification of the technical content is crucial too. When people modify the software, adding or changing features, if they are conscientious they will change the manual too--so they can provide accurate and clear documentation for the modified program. A manual that leaves you no choice but to write a new manual to document a changed version of the program is not really available to our community. Some kinds of limits on the way modification is handled are acceptable. For example, requirements to preserve the original author's copyright notice, the distribution terms, or the list of authors, are ok. It is also no problem to require modified versions to include notice that they were modified. Even entire sections that may not be deleted or changed are acceptable, as long as they deal with nontechnical topics (like this one). These kinds of restrictions are acceptable because they don't obstruct the community's normal use of the manual. However, it must be possible to modify all the _technical_ content of the manual, and then distribute the result in all the usual media, through all the usual channels. Otherwise, the restrictions obstruct the use of the manual, it is not free, and we need another manual to replace it. Please spread the word about this issue. Our community continues to lose manuals to proprietary publishing. If we spread the word that free software needs free reference manuals and free tutorials, perhaps the next person who wants to contribute by writing documentation will realize, before it is too late, that only free manuals contribute to the free software community. If you are writing documentation, please insist on publishing it under the GNU Free Documentation License or another free documentation license. Remember that this decision requires your approval--you don't have to let the publisher decide. Some commercial publishers will use a free license if you insist, but they will not propose the option; it is up to you to raise the issue and say firmly that this is what you want. If the publisher you are dealing with refuses, please try other publishers. If you're not sure whether a proposed license is free, write to . You can encourage commercial publishers to sell more free, copylefted manuals and tutorials by buying them, and particularly by buying copies from the publishers that paid for their writing or for major improvements. Meanwhile, try to avoid buying non-free documentation at all. Check the distribution terms of a manual before you buy it, and insist that whoever seeks your business must respect your freedom. Check the history of the book, and try to reward the publishers that have paid or pay the authors to work on it. The Free Software Foundation maintains a list of free documentation published by other publishers, at `http://www.fsf.org/doc/other-free-books.html'.  File: gdb.info, Node: Contributors, Prev: Free Documentation, Up: Summary Contributors to GDB =================== Richard Stallman was the original author of GDB, and of many other GNU programs. Many others have contributed to its development. This section attempts to credit major contributors. One of the virtues of free software is that everyone is free to contribute to it; with regret, we cannot actually acknowledge everyone here. The file `ChangeLog' in the GDB distribution approximates a blow-by-blow account. Changes much prior to version 2.0 are lost in the mists of time. _Plea:_ Additions to this section are particularly welcome. If you or your friends (or enemies, to be evenhanded) have been unfairly omitted from this list, we would like to add your names! So that they may not regard their many labors as thankless, we particularly thank those who shepherded GDB through major releases: Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0); Jim Blandy (release 4.18); Jason Molenda (release 4.17); Stan Shebs (release 4.14); Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); Jim Kingdon (releases 3.5, 3.4, and 3.3); and Randy Smith (releases 3.2, 3.1, and 3.0). Richard Stallman, assisted at various times by Peter TerMaat, Chris Hanson, and Richard Mlynarik, handled releases through 2.8. Michael Tiemann is the author of most of the GNU C++ support in GDB, with significant additional contributions from Per Bothner and Daniel Berlin. James Clark wrote the GNU C++ demangler. Early work on C++ was by Peter TerMaat (who also did much general update work leading to release 3.0). GDB uses the BFD subroutine library to examine multiple object-file formats; BFD was a joint project of David V. Henkel-Wallace, Rich Pixley, Steve Chamberlain, and John Gilmore. David Johnson wrote the original COFF support; Pace Willison did the original support for encapsulated COFF. Brent Benson of Harris Computer Systems contributed DWARF 2 support. Adam de Boor and Bradley Davis contributed the ISI Optimum V support. Per Bothner, Noboyuki Hikichi, and Alessandro Forin contributed MIPS support. Jean-Daniel Fekete contributed Sun 386i support. Chris Hanson improved the HP9000 support. Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. David Johnson contributed Encore Umax support. Jyrki Kuoppala contributed Altos 3068 support. Jeff Law contributed HP PA and SOM support. Keith Packard contributed NS32K support. Doug Rabson contributed Acorn Risc Machine support. Bob Rusk contributed Harris Nighthawk CX-UX support. Chris Smith contributed Convex support (and Fortran debugging). Jonathan Stone contributed Pyramid support. Michael Tiemann contributed SPARC support. Tim Tucker contributed support for the Gould NP1 and Gould Powernode. Pace Willison contributed Intel 386 support. Jay Vosburgh contributed Symmetry support. Marko Mlinar contributed OpenRISC 1000 support. Andreas Schwab contributed M68K GNU/Linux support. Rich Schaefer and Peter Schauer helped with support of SunOS shared libraries. Jay Fenlason and Roland McGrath ensured that GDB and GAS agree about several machine instruction sets. Patrick Duval, Ted Goldstein, Vikram Koka and Glenn Engel helped develop remote debugging. Intel Corporation, Wind River Systems, AMD, and ARM contributed remote debugging modules for the i960, VxWorks, A29K UDI, and RDI targets, respectively. Brian Fox is the author of the readline libraries providing command-line editing and command history. Andrew Beers of SUNY Buffalo wrote the language-switching code, the Modula-2 support, and contributed the Languages chapter of this manual. Fred Fish wrote most of the support for Unix System Vr4. He also enhanced the command-completion support to cover C++ overloaded symbols. Hitachi America (now Renesas America), Ltd. sponsored the support for H8/300, H8/500, and Super-H processors. NEC sponsored the support for the v850, Vr4xxx, and Vr5xxx processors. Mitsubishi (now Renesas) sponsored the support for D10V, D30V, and M32R/D processors. Toshiba sponsored the support for the TX39 Mips processor. Matsushita sponsored the support for the MN10200 and MN10300 processors. Fujitsu sponsored the support for SPARClite and FR30 processors. Kung Hsu, Jeff Law, and Rick Sladkey added support for hardware watchpoints. Michael Snyder added support for tracepoints. Stu Grossman wrote gdbserver. Jim Kingdon, Peter Schauer, Ian Taylor, and Stu Grossman made nearly innumerable bug fixes and cleanups throughout GDB. The following people at the Hewlett-Packard Company contributed support for the PA-RISC 2.0 architecture, HP-UX 10.20, 10.30, and 11.0 (narrow mode), HP's implementation of kernel threads, HP's aC++ compiler, and the Text User Interface (nee Terminal User Interface): Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann, Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase provided HP-specific information in this manual. DJ Delorie ported GDB to MS-DOS, for the DJGPP project. Robert Hoehne made significant contributions to the DJGPP port. Cygnus Solutions has sponsored GDB maintenance and much of its development since 1991. Cygnus engineers who have worked on GDB fulltime include Mark Alexander, Jim Blandy, Per Bothner, Kevin Buettner, Edith Epstein, Chris Faylor, Fred Fish, Martin Hunt, Jim Ingham, John Gilmore, Stu Grossman, Kung Hsu, Jim Kingdon, John Metzler, Fernando Nasser, Geoffrey Noer, Dawn Perchik, Rich Pixley, Zdenek Radouch, Keith Seitz, Stan Shebs, David Taylor, and Elena Zannoni. In addition, Dave Brolley, Ian Carmichael, Steve Chamberlain, Nick Clifton, JT Conklin, Stan Cox, DJ Delorie, Ulrich Drepper, Frank Eigler, Doug Evans, Sean Fagan, David Henkel-Wallace, Richard Henderson, Jeff Holcomb, Jeff Law, Jim Lemke, Tom Lord, Bob Manson, Michael Meissner, Jason Merrill, Catherine Moore, Drew Moseley, Ken Raeburn, Gavin Romig-Koch, Rob Savoye, Jamie Smith, Mike Stump, Ian Taylor, Angela Thomas, Michael Tiemann, Tom Tromey, Ron Unrau, Jim Wilson, and David Zuhn have made contributions both large and small. Andrew Cagney, Fernando Nasser, and Elena Zannoni, while working for Cygnus Solutions, implemented the original GDB/MI interface. Jim Blandy added support for preprocessor macros, while working for Red Hat. Andrew Cagney designed GDB's architecture vector. Many people including Andrew Cagney, Stephane Carrez, Randolph Chung, Nick Duffek, Richard Henderson, Mark Kettenis, Grace Sainsbury, Kei Sakamoto, Yoshinori Sato, Michael Snyder, Andreas Schwab, Jason Thorpe, Corinna Vinschen, Ulrich Weigand, and Elena Zannoni, helped with the migration of old architectures to this new framework. Andrew Cagney completely re-designed and re-implemented GDB's unwinder framework, this consisting of a fresh new design featuring frame IDs, independent frame sniffers, and the sentinel frame. Mark Kettenis implemented the DWARF 2 unwinder, Jeff Johnston the libunwind unwinder, and Andrew Cagney the dummy, sentinel, tramp, and trad unwinders. The architecture-specific changes, each involving a complete rewrite of the architecture's frame code, were carried out by Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich Weigand. Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from Tensilica, Inc. contributed support for Xtensa processors. Others who have worked on the Xtensa port of GDB in the past include Steve Tjiang, John Newlin, and Scott Foehner. Michael Eager and staff of Xilinx, Inc., contributed support for the Xilinx MicroBlaze architecture. Initial support for the FreeBSD/mips target and native configuration was developed by SRI International and the University of Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme. Initial support for the FreeBSD/riscv target and native configuration was developed by SRI International and the University of Cambridge Computer Laboratory (Department of Computer Science and Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the DARPA SSITH research programme. The original port to the OpenRISC 1000 is believed to be due to Alessandro Forin and Per Bothner. More recent ports have been the work of Jeremy Bennett, Franck Jullien, Stefan Wallentowitz and Stafford Horne. Weimin Pan, David Faust and Jose E. Marchesi contributed support for the Linux kernel BPF virtual architecture. This work was sponsored by Oracle.  File: gdb.info, Node: Sample Session, Next: Invocation, Prev: Summary, Up: Top 1 A Sample GDB Session ********************** You can use this manual at your leisure to read all about GDB. However, a handful of commands are enough to get started using the debugger. This chapter illustrates those commands. One of the preliminary versions of GNU `m4' (a generic macro processor) exhibits the following bug: sometimes, when we change its quote strings from the default, the commands used to capture one macro definition within another stop working. In the following short `m4' session, we define a macro `foo' which expands to `0000'; we then use the `m4' built-in `defn' to define `bar' as the same thing. However, when we change the open quote string to `' and the close quote string to `', the same procedure fails to define a new synonym `baz': $ cd gnu/m4 $ ./m4 define(foo,0000) foo 0000 define(bar,defn(`foo')) bar 0000 changequote(,) define(baz,defn(foo)) baz Ctrl-d m4: End of input: 0: fatal error: EOF in string Let us use GDB to try to see what is going on. $ gdb m4 GDB is free software and you are welcome to distribute copies of it under certain conditions; type "show copying" to see the conditions. There is absolutely no warranty for GDB; type "show warranty" for details. GDB 15.1, Copyright 1999 Free Software Foundation, Inc... (gdb) GDB reads only enough symbol data to know where to find the rest when needed; as a result, the first prompt comes up very quickly. We now tell GDB to use a narrower display width than usual, so that examples fit in this manual. (gdb) set width 70 We need to see how the `m4' built-in `changequote' works. Having looked at the source, we know the relevant subroutine is `m4_changequote', so we set a breakpoint there with the GDB `break' command. (gdb) break m4_changequote Breakpoint 1 at 0x62f4: file builtin.c, line 879. Using the `run' command, we start `m4' running under GDB control; as long as control does not reach the `m4_changequote' subroutine, the program runs as usual: (gdb) run Starting program: /work/Editorial/gdb/gnu/m4/m4 define(foo,0000) foo 0000 To trigger the breakpoint, we call `changequote'. GDB suspends execution of `m4', displaying information about the context where it stops. changequote(,) Breakpoint 1, m4_changequote (argc=3, argv=0x33c70) at builtin.c:879 879 if (bad_argc(TOKEN_DATA_TEXT(argv[0]),argc,1,3)) Now we use the command `n' (`next') to advance execution to the next line of the current function. (gdb) n 882 set_quotes((argc >= 2) ? TOKEN_DATA_TEXT(argv[1])\ : nil, `set_quotes' looks like a promising subroutine. We can go into it by using the command `s' (`step') instead of `next'. `step' goes to the next line to be executed in _any_ subroutine, so it steps into `set_quotes'. (gdb) s set_quotes (lq=0x34c78 "", rq=0x34c88 "") at input.c:530 530 if (lquote != def_lquote) The display that shows the subroutine where `m4' is now suspended (and its arguments) is called a stack frame display. It shows a summary of the stack. We can use the `backtrace' command (which can also be spelled `bt'), to see where we are in the stack as a whole: the `backtrace' command displays a stack frame for each active subroutine. (gdb) bt #0 set_quotes (lq=0x34c78 "", rq=0x34c88 "") at input.c:530 #1 0x6344 in m4_changequote (argc=3, argv=0x33c70) at builtin.c:882 #2 0x8174 in expand_macro (sym=0x33320) at macro.c:242 #3 0x7a88 in expand_token (obs=0x0, t=209696, td=0xf7fffa30) at macro.c:71 #4 0x79dc in expand_input () at macro.c:40 #5 0x2930 in main (argc=0, argv=0xf7fffb20) at m4.c:195 We step through a few more lines to see what happens. The first two times, we can use `s'; the next two times we use `n' to avoid falling into the `xstrdup' subroutine. (gdb) s 0x3b5c 532 if (rquote != def_rquote) (gdb) s 0x3b80 535 lquote = (lq == nil || *lq == '\0') ? \ def_lquote : xstrdup(lq); (gdb) n 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ : xstrdup(rq); (gdb) n 538 len_lquote = strlen(rquote); The last line displayed looks a little odd; we can examine the variables `lquote' and `rquote' to see if they are in fact the new left and right quotes we specified. We use the command `p' (`print') to see their values. (gdb) p lquote $1 = 0x35d40 "" (gdb) p rquote $2 = 0x35d50 "" `lquote' and `rquote' are indeed the new left and right quotes. To look at some context, we can display ten lines of source surrounding the current line with the `l' (`list') command. (gdb) l 533 xfree(rquote); 534 535 lquote = (lq == nil || *lq == '\0') ? def_lquote\ : xstrdup (lq); 536 rquote = (rq == nil || *rq == '\0') ? def_rquote\ : xstrdup (rq); 537 538 len_lquote = strlen(rquote); 539 len_rquote = strlen(lquote); 540 } 541 542 void Let us step past the two lines that set `len_lquote' and `len_rquote', and then examine the values of those variables. (gdb) n 539 len_rquote = strlen(lquote); (gdb) n 540 } (gdb) p len_lquote $3 = 9 (gdb) p len_rquote $4 = 7 That certainly looks wrong, assuming `len_lquote' and `len_rquote' are meant to be the lengths of `lquote' and `rquote' respectively. We can set them to better values using the `p' command, since it can print the value of any expression--and that expression can include subroutine calls and assignments. (gdb) p len_lquote=strlen(lquote) $5 = 7 (gdb) p len_rquote=strlen(rquote) $6 = 9 Is that enough to fix the problem of using the new quotes with the `m4' built-in `defn'? We can allow `m4' to continue executing with the `c' (`continue') command, and then try the example that caused trouble initially: (gdb) c Continuing. define(baz,defn(foo)) baz 0000 Success! The new quotes now work just as well as the default ones. The problem seems to have been just the two typos defining the wrong lengths. We allow `m4' exit by giving it an EOF as input: Ctrl-d Program exited normally. The message `Program exited normally.' is from GDB; it indicates `m4' has finished executing. We can end our GDB session with the GDB `quit' command. (gdb) quit  File: gdb.info, Node: Invocation, Next: Commands, Prev: Sample Session, Up: Top 2 Getting In and Out of GDB *************************** This chapter discusses how to start GDB, and how to get out of it. The essentials are: * type `gdb' to start GDB. * type `quit', `exit' or `Ctrl-d' to exit. * Menu: * Invoking GDB:: How to start GDB * Quitting GDB:: How to quit GDB * Shell Commands:: How to use shell commands inside GDB * Logging Output:: How to log GDB's output to a file  File: gdb.info, Node: Invoking GDB, Next: Quitting GDB, Up: Invocation 2.1 Invoking GDB ================ Invoke GDB by running the program `gdb'. Once started, GDB reads commands from the terminal until you tell it to exit. You can also run `gdb' with a variety of arguments and options, to specify more of your debugging environment at the outset. The command-line options described here are designed to cover a variety of situations; in some environments, some of these options may effectively be unavailable. The most usual way to start GDB is with one argument, specifying an executable program: gdb PROGRAM You can also start with both an executable program and a core file specified: gdb PROGRAM CORE You can, instead, specify a process ID as a second argument or use option `-p', if you want to debug a running process: gdb PROGRAM 1234 gdb -p 1234 would attach GDB to process `1234'. With option `-p' you can omit the PROGRAM filename. Taking advantage of the second command-line argument requires a fairly complete operating system; when you use GDB as a remote debugger attached to a bare board, there may not be any notion of "process", and there is often no way to get a core dump. GDB will warn you if it is unable to attach or to read core dumps. You can optionally have `gdb' pass any arguments after the executable file to the inferior using `--args'. This option stops option processing. gdb --args gcc -O2 -c foo.c This will cause `gdb' to debug `gcc', and to set `gcc''s command-line arguments (*note Arguments::) to `-O2 -c foo.c'. You can run `gdb' without printing the front material, which describes GDB's non-warranty, by specifying `--silent' (or `-q'/`--quiet'): gdb --silent You can further control how GDB starts up by using command-line options. GDB itself can remind you of the options available. Type gdb -help to display all available options and briefly describe their use (`gdb -h' is a shorter equivalent). All options and command line arguments you give are processed in sequential order. The order makes a difference when the `-x' option is used. * Menu: * File Options:: Choosing files * Mode Options:: Choosing modes * Startup:: What GDB does during startup * Initialization Files:: Initialization Files  File: gdb.info, Node: File Options, Next: Mode Options, Up: Invoking GDB 2.1.1 Choosing Files -------------------- When GDB starts, it reads any arguments other than options as specifying an executable file and core file (or process ID). This is the same as if the arguments were specified by the `-se' and `-c' (or `-p') options respectively. (GDB reads the first argument that does not have an associated option flag as equivalent to the `-se' option followed by that argument; and the second argument that does not have an associated option flag, if any, as equivalent to the `-c'/`-p' option followed by that argument.) If the second argument begins with a decimal digit, GDB will first attempt to attach to it as a process, and if that fails, attempt to open it as a corefile. If you have a corefile whose name begins with a digit, you can prevent GDB from treating it as a pid by prefixing it with `./', e.g. `./12345'. If GDB has not been configured to included core file support, such as for most embedded targets, then it will complain about a second argument and ignore it. For the `-s', `-e', and `-se' options, and their long form equivalents, the method used to search the file system for the symbol and/or executable file is the same as that used by the `file' command. *Note file: Files. Many options have both long and short forms; both are shown in the following list. GDB also recognizes the long forms if you truncate them, so long as enough of the option is present to be unambiguous. (If you prefer, you can flag option arguments with `--' rather than `-', though we illustrate the more usual convention.) `-symbols FILE' `-s FILE' Read symbol table from file FILE. `-exec FILE' `-e FILE' Use file FILE as the executable file to execute when appropriate, and for examining pure data in conjunction with a core dump. `-se FILE' Read symbol table from file FILE and use it as the executable file. `-core FILE' `-c FILE' Use file FILE as a core dump to examine. `-pid NUMBER' `-p NUMBER' Connect to process ID NUMBER, as with the `attach' command. `-command FILE' `-x FILE' Execute commands from file FILE. The contents of this file is evaluated exactly as the `source' command would. *Note Command files: Command Files. `-eval-command COMMAND' `-ex COMMAND' Execute a single GDB command. This option may be used multiple times to call multiple commands. It may also be interleaved with `-command' as required. gdb -ex 'target sim' -ex 'load' \ -x setbreakpoints -ex 'run' a.out `-init-command FILE' `-ix FILE' Execute commands from file FILE before loading the inferior (but after loading gdbinit files). *Note Startup::. `-init-eval-command COMMAND' `-iex COMMAND' Execute a single GDB command before loading the inferior (but after loading gdbinit files). *Note Startup::. `-early-init-command FILE' `-eix FILE' Execute commands from FILE very early in the initialization process, before any output is produced. *Note Startup::. `-early-init-eval-command COMMAND' `-eiex COMMAND' Execute a single GDB command very early in the initialization process, before any output is produced. `-directory DIRECTORY' `-d DIRECTORY' Add DIRECTORY to the path to search for source and script files. `-r' `-readnow' Read each symbol file's entire symbol table immediately, rather than the default, which is to read it incrementally as it is needed. This makes startup slower, but makes future operations faster. `--readnever' Do not read each symbol file's symbolic debug information. This makes startup faster but at the expense of not being able to perform symbolic debugging. DWARF unwind information is also not read, meaning backtraces may become incomplete or inaccurate. One use of this is when a user simply wants to do the following sequence: attach, dump core, detach. Loading the debugging information in this case is an unnecessary cause of delay.  File: gdb.info, Node: Mode Options, Next: Startup, Prev: File Options, Up: Invoking GDB 2.1.2 Choosing Modes -------------------- You can run GDB in various alternative modes--for example, in batch mode or quiet mode. `-nx' `-n' Do not execute commands found in any initialization files (*note Initialization Files::). `-nh' Do not execute commands found in any home directory initialization file (*note Home directory initialization file: Initialization Files.). The system wide and current directory initialization files are still loaded. `-quiet' `-silent' `-q' "Quiet". Do not print the introductory and copyright messages. These messages are also suppressed in batch mode. This can also be enabled using `set startup-quietly on'. The default is `off'. Use `show startup-quietly' to see the current setting. Place `set startup-quietly on' into your early initialization file (*note Initialization Files: Initialization Files.) to have future GDB sessions startup quietly. `-batch' Run in batch mode. Exit with status `0' after processing all the command files specified with `-x' (and all commands from initialization files, if not inhibited with `-n'). Exit with nonzero status if an error occurs in executing the GDB commands in the command files. Batch mode also disables pagination, sets unlimited terminal width and height *note Screen Size::, and acts as if `set confirm off' were in effect (*note Messages/Warnings::). Batch mode may be useful for running GDB as a filter, for example to download and run a program on another computer; in order to make this more useful, the message Program exited normally. (which is ordinarily issued whenever a program running under GDB control terminates) is not issued when running in batch mode. `-batch-silent' Run in batch mode exactly like `-batch', but totally silently. All GDB output to `stdout' is prevented (`stderr' is unaffected). This is much quieter than `-silent' and would be useless for an interactive session. This is particularly useful when using targets that give `Loading section' messages, for example. Note that targets that give their output via GDB, as opposed to writing directly to `stdout', will also be made silent. `-return-child-result' The return code from GDB will be the return code from the child process (the process being debugged), with the following exceptions: * GDB exits abnormally. E.g., due to an incorrect argument or an internal error. In this case the exit code is the same as it would have been without `-return-child-result'. * The user quits with an explicit value. E.g., `quit 1'. * The child process never runs, or is not allowed to terminate, in which case the exit code will be -1. This option is useful in conjunction with `-batch' or `-batch-silent', when GDB is being used as a remote program loader or simulator interface. `-nowindows' `-nw' "No windows". If GDB comes with a graphical user interface (GUI) built in, then this option tells GDB to only use the command-line interface. If no GUI is available, this option has no effect. `-windows' `-w' If GDB includes a GUI, then this option requires it to be used if possible. `-cd DIRECTORY' Run GDB using DIRECTORY as its working directory, instead of the current directory. `-data-directory DIRECTORY' `-D DIRECTORY' Run GDB using DIRECTORY as its data directory. The data directory is where GDB searches for its auxiliary files. *Note Data Files::. `-fullname' `-f' GNU Emacs sets this option when it runs GDB as a subprocess. It tells GDB to output the full file name and line number in a standard, recognizable fashion each time a stack frame is displayed (which includes each time your program stops). This recognizable format looks like two `\032' characters, followed by the file name, line number and character position separated by colons, and a newline. The Emacs-to-GDB interface program uses the two `\032' characters as a signal to display the source code for the frame. `-annotate LEVEL' This option sets the "annotation level" inside GDB. Its effect is identical to using `set annotate LEVEL' (*note Annotations::). The annotation LEVEL controls how much information GDB prints together with its prompt, values of expressions, source lines, and other types of output. Level 0 is the normal, level 1 is for use when GDB is run as a subprocess of GNU Emacs, level 3 is the maximum annotation suitable for programs that control GDB, and level 2 has been deprecated. The annotation mechanism has largely been superseded by GDB/MI (*note GDB/MI::). `--args' Change interpretation of command line so that arguments following the executable file are passed as command line arguments to the inferior. This option stops option processing. `-baud BPS' `-b BPS' Set the line speed (baud rate or bits per second) of any serial interface used by GDB for remote debugging. `-l TIMEOUT' Set the timeout (in seconds) of any communication used by GDB for remote debugging. `-tty DEVICE' `-t DEVICE' Run using DEVICE for your program's standard input and output. `-tui' Activate the "Text User Interface" when starting. The Text User Interface manages several text windows on the terminal, showing source, assembly, registers and GDB command outputs (*note GDB Text User Interface: TUI.). Do not use this option if you run GDB from Emacs (*note Using GDB under GNU Emacs: Emacs.). `-interpreter INTERP' Use the interpreter INTERP for interface with the controlling program or device. This option is meant to be set by programs which communicate with GDB using it as a back end. *Note Command Interpreters: Interpreters. `--interpreter=mi' (or `--interpreter=mi3') causes GDB to use the "GDB/MI interface" version 3 (*note The GDB/MI Interface: GDB/MI.) included since GDB version 9.1. GDB/MI version 2 (`mi2'), included in GDB 6.0 and version 1 (`mi1'), included in GDB 5.3, are also available. Earlier GDB/MI interfaces are no longer supported. `-write' Open the executable and core files for both reading and writing. This is equivalent to the `set write on' command inside GDB (*note Patching::). `-statistics' This option causes GDB to print statistics about time and memory usage after it completes each command and returns to the prompt. `-version' This option causes GDB to print its version number and no-warranty blurb, and exit. `-configuration' This option causes GDB to print details about its build-time configuration parameters, and then exit. These details can be important when reporting GDB bugs (*note GDB Bugs::).  File: gdb.info, Node: Startup, Next: Initialization Files, Prev: Mode Options, Up: Invoking GDB 2.1.3 What GDB Does During Startup ---------------------------------- Here's the description of what GDB does during session startup: 1. Performs minimal setup required to initialize basic internal state. 2. Reads commands from the early initialization file (if any) in your home directory. Only a restricted set of commands can be placed into an early initialization file, see *Note Initialization Files::, for details. 3. Executes commands and command files specified by the `-eiex' and `-eix' command line options in their specified order. Only a restricted set of commands can be used with `-eiex' and `eix', see *Note Initialization Files::, for details. 4. Sets up the command interpreter as specified by the command line (*note interpreter: Mode Options.). 5. Reads the system wide initialization file and the files from the system wide initialization directory, *note System Wide Init Files::. 6. Reads the initialization file (if any) in your home directory and executes all the commands in that file, *note Home Directory Init File::. 7. Executes commands and command files specified by the `-iex' and `-ix' options in their specified order. Usually you should use the `-ex' and `-x' options instead, but this way you can apply settings before GDB init files get executed and before inferior gets loaded. 8. Processes command line options and operands. 9. Reads and executes the commands from the initialization file (if any) in the current working directory as long as `set auto-load local-gdbinit' is set to `on' (*note Init File in the Current Directory::). This is only done if the current directory is different from your home directory. Thus, you can have more than one init file, one generic in your home directory, and another, specific to the program you are debugging, in the directory where you invoke GDB. *Note Init File in the Current Directory during Startup::. 10. If the command line specified a program to debug, or a process to attach to, or a core file, GDB loads any auto-loaded scripts provided for the program or for its loaded shared libraries. *Note Auto-loading::. If you wish to disable the auto-loading during startup, you must do something like the following: $ gdb -iex "set auto-load python-scripts off" myprogram Option `-ex' does not work because the auto-loading is then turned off too late. 11. Executes commands and command files specified by the `-ex' and `-x' options in their specified order. *Note Command Files::, for more details about GDB command files. 12. Reads the command history recorded in the "history file". *Note Command History::, for more details about the command history and the files where GDB records it.  File: gdb.info, Node: Initialization Files, Prev: Startup, Up: Invoking GDB 2.1.4 Initialization Files -------------------------- During startup (*note Startup::) GDB will execute commands from several initialization files. These initialization files use the same syntax as "command files" (*note Command Files::) and are processed by GDB in the same way. To display the list of initialization files loaded by GDB at startup, in the order they will be loaded, you can use `gdb --help'. The "early initialization" file is loaded very early in GDB's initialization process, before the interpreter (*note Interpreters::) has been initialized, and before the default target (*note Targets::) is initialized. Only `set' or `source' commands should be placed into an early initialization file, and the only `set' commands that can be used are those that control how GDB starts up. Commands that can be placed into an early initialization file will be documented as such throughout this manual. Any command that is not documented as being suitable for an early initialization file should instead be placed into a general initialization file. Command files passed to `--early-init-command' or `-eix' are also early initialization files, with the same command restrictions. Only commands that can appear in an early initialization file should be passed to `--early-init-eval-command' or `-eiex'. In contrast, the "general initialization" files are processed later, after GDB has finished its own internal initialization process, any valid command can be used in these files. Throughout the rest of this document the term "initialization file" refers to one of the general initialization files, not the early initialization file. Any discussion of the early initialization file will specifically mention that it is the early initialization file being discussed. As the system wide and home directory initialization files are processed before most command line options, changes to settings (e.g. `set complaints') can affect subsequent processing of command line options and operands. The following sections describe where GDB looks for the early initialization and initialization files, and the order that the files are searched for. 2.1.4.1 Home directory early initialization files ................................................. GDB initially looks for an early initialization file in the users home directory(1). There are a number of locations that GDB will search in the home directory, these locations are searched in order and GDB will load the first file that it finds, and subsequent locations will not be checked. On non-macOS hosts the locations searched are: * The file `gdb/gdbearlyinit' within the directory pointed to by the environment variable `XDG_CONFIG_HOME', if it is defined. * The file `.config/gdb/gdbearlyinit' within the directory pointed to by the environment variable `HOME', if it is defined. * The file `.gdbearlyinit' within the directory pointed to by the environment variable `HOME', if it is defined. By contrast, on macOS hosts the locations searched are: * The file `Library/Preferences/gdb/gdbearlyinit' within the directory pointed to by the environment variable `HOME', if it is defined. * The file `.gdbearlyinit' within the directory pointed to by the environment variable `HOME', if it is defined. It is possible to prevent the home directory early initialization file from being loaded using the `-nx' or `-nh' command line options, *note Choosing Modes: Mode Options. 2.1.4.2 System wide initialization files ........................................ There are two locations that are searched for system wide initialization files. Both of these locations are always checked: ``system.gdbinit'' This is a single system-wide initialization file. Its location is specified with the `--with-system-gdbinit' configure option (*note System-wide configuration::). It is loaded first when GDB starts, before command line options have been processed. ``system.gdbinit.d'' This is the system-wide initialization directory. Its location is specified with the `--with-system-gdbinit-dir' configure option (*note System-wide configuration::). Files in this directory are loaded in alphabetical order immediately after `system.gdbinit' (if enabled) when GDB starts, before command line options have been processed. Files need to have a recognized scripting language extension (`.py'/`.scm') or be named with a `.gdb' extension to be interpreted as regular GDB commands. GDB will not recurse into any subdirectories of this directory. It is possible to prevent the system wide initialization files from being loaded using the `-nx' command line option, *note Choosing Modes: Mode Options. 2.1.4.3 Home directory initialization file .......................................... After loading the system wide initialization files GDB will look for an initialization file in the users home directory(2). There are a number of locations that GDB will search in the home directory, these locations are searched in order and GDB will load the first file that it finds, and subsequent locations will not be checked. On non-Apple hosts the locations searched are: `$XDG_CONFIG_HOME/gdb/gdbinit' `$HOME/.config/gdb/gdbinit' `$HOME/.gdbinit' While on Apple hosts the locations searched are: `$HOME/Library/Preferences/gdb/gdbinit' `$HOME/.gdbinit' It is possible to prevent the home directory initialization file from being loaded using the `-nx' or `-nh' command line options, *note Choosing Modes: Mode Options. The DJGPP port of GDB uses the name `gdb.ini' instead of `.gdbinit' or `gdbinit', due to the limitations of file names imposed by DOS filesystems. The Windows port of GDB uses the standard name, but if it finds a `gdb.ini' file in your home directory, it warns you about that and suggests to rename the file to the standard name. 2.1.4.4 Local directory initialization file ........................................... GDB will check the current directory for a file called `.gdbinit'. It is loaded last, after command line options other than `-x' and `-ex' have been processed. The command line options `-x' and `-ex' are processed last, after `.gdbinit' has been loaded, *note Choosing Files: File Options. If the file in the current directory was already loaded as the home directory initialization file then it will not be loaded a second time. It is possible to prevent the local directory initialization file from being loaded using the `-nx' command line option, *note Choosing Modes: Mode Options. ---------- Footnotes ---------- (1) On DOS/Windows systems, the home directory is the one pointed to by the `HOME' environment variable. (2) On DOS/Windows systems, the home directory is the one pointed to by the `HOME' environment variable.  File: gdb.info, Node: Quitting GDB, Next: Shell Commands, Prev: Invoking GDB, Up: Invocation 2.2 Quitting GDB ================ `quit [EXPRESSION]' `exit [EXPRESSION]' `q' To exit GDB, use the `quit' command (abbreviated `q'), the `exit' command, or type an end-of-file character (usually `Ctrl-d'). If you do not supply EXPRESSION, GDB will terminate normally; otherwise it will terminate using the result of EXPRESSION as the error code. An interrupt (often `Ctrl-c') does not exit from GDB, but rather terminates the action of any GDB command that is in progress and returns to GDB command level. It is safe to type the interrupt character at any time because GDB does not allow it to take effect until a time when it is safe. If you have been using GDB to control an attached process or device, you can release it with the `detach' command (*note Debugging an Already-running Process: Attach.).  File: gdb.info, Node: Shell Commands, Next: Logging Output, Prev: Quitting GDB, Up: Invocation 2.3 Shell Commands ================== If you need to execute occasional shell commands during your debugging session, there is no need to leave or suspend GDB; you can just use the `shell' command. `shell COMMAND-STRING' `!COMMAND-STRING' Invoke a shell to execute COMMAND-STRING. Note that no space is needed between `!' and COMMAND-STRING. On GNU and Unix systems, the environment variable `SHELL', if it exists, determines which shell to run. Otherwise GDB uses the default shell (`/bin/sh' on GNU and Unix systems, `cmd.exe' on MS-Windows, `COMMAND.COM' on MS-DOS, etc.). You may also invoke shell commands from expressions, using the `$_shell' convenience function. *Note $_shell convenience function::. The utility `make' is often needed in development environments. You do not have to use the `shell' command for this purpose in GDB: `make MAKE-ARGS' Execute the `make' program with the specified arguments. This is equivalent to `shell make MAKE-ARGS'. `pipe [COMMAND] | SHELL_COMMAND' `| [COMMAND] | SHELL_COMMAND' `pipe -d DELIM COMMAND DELIM SHELL_COMMAND' `| -d DELIM COMMAND DELIM SHELL_COMMAND' Executes COMMAND and sends its output to SHELL_COMMAND. Note that no space is needed around `|'. If no COMMAND is provided, the last command executed is repeated. In case the COMMAND contains a `|', the option `-d DELIM' can be used to specify an alternate delimiter string DELIM that separates the COMMAND from the SHELL_COMMAND. Example: (gdb) p var $1 = { black = 144, red = 233, green = 377, blue = 610, white = 987 } (gdb) pipe p var|wc 7 19 80 (gdb) |p var|wc -l 7 (gdb) p /x var $4 = { black = 0x90, red = 0xe9, green = 0x179, blue = 0x262, white = 0x3db } (gdb) ||grep red red => 0xe9, (gdb) | -d ! echo this contains a | char\n ! sed -e 's/|/PIPE/' this contains a PIPE char (gdb) | -d xxx echo this contains a | char!\n xxx sed -e 's/|/PIPE/' this contains a PIPE char! (gdb) The convenience variables `$_shell_exitcode' and `$_shell_exitsignal' can be used to examine the exit status of the last shell command launched by `shell', `make', `pipe' and `|'. *Note Convenience Variables: Convenience Vars.  File: gdb.info, Node: Logging Output, Prev: Shell Commands, Up: Invocation 2.4 Logging Output ================== You may want to save the output of GDB commands to a file. There are several commands to control GDB's logging. `set logging enabled [on|off]' Enable or disable logging. `set logging file FILE' Change the name of the current logfile. The default logfile is `gdb.txt'. `set logging overwrite [on|off]' By default, GDB will append to the logfile. Set `overwrite' if you want `set logging enabled on' to overwrite the logfile instead. `set logging redirect [on|off]' By default, GDB output will go to both the terminal and the logfile. Set `redirect' if you want output to go only to the log file. `set logging debugredirect [on|off]' By default, GDB debug output will go to both the terminal and the logfile. Set `debugredirect' if you want debug output to go only to the log file. `show logging' Show the current values of the logging settings. You can also redirect the output of a GDB command to a shell command. *Note pipe::.  File: gdb.info, Node: Commands, Next: Running, Prev: Invocation, Up: Top 3 GDB Commands ************** You can abbreviate a GDB command to the first few letters of the command name, if that abbreviation is unambiguous; and you can repeat certain GDB commands by typing just . You can also use the key to get GDB to fill out the rest of a word in a command (or to show you the alternatives available, if there is more than one possibility). * Menu: * Command Syntax:: How to give commands to GDB * Command Settings:: How to change default behavior of commands * Completion:: Command completion * Filename Arguments:: Filenames As Command Arguments * Command Options:: Command options * Help:: How to ask GDB for help  File: gdb.info, Node: Command Syntax, Next: Command Settings, Up: Commands 3.1 Command Syntax ================== A GDB command is a single line of input. There is no limit on how long it can be. It starts with a command name, which is followed by arguments whose meaning depends on the command name. For example, the command `step' accepts an argument which is the number of times to step, as in `step 5'. You can also use the `step' command with no arguments. Some commands do not allow any arguments. GDB command names may always be truncated if that abbreviation is unambiguous. Other possible command abbreviations are listed in the documentation for individual commands. In some cases, even ambiguous abbreviations are allowed; for example, `s' is specially defined as equivalent to `step' even though there are other commands whose names start with `s'. You can test abbreviations by using them as arguments to the `help' command. A blank line as input to GDB (typing just ) means to repeat the previous command. Certain commands (for example, `run') will not repeat this way; these are commands whose unintentional repetition might cause trouble and which you are unlikely to want to repeat. User-defined commands can disable this feature; see *Note dont-repeat: Define. The `list' and `x' commands, when you repeat them with , construct new arguments rather than repeating exactly as typed. This permits easy scanning of source or memory. GDB can also use in another way: to partition lengthy output, in a way similar to the common utility `more' (*note Screen Size: Screen Size.). Since it is easy to press one too many in this situation, GDB disables command repetition after any command that generates this sort of display. Any text from a `#' to the end of the line is a comment; it does nothing. This is useful mainly in command files (*note Command Files: Command Files.). The `Ctrl-o' binding is useful for repeating a complex sequence of commands. This command accepts the current line, like , and then fetches the next line relative to the current line from the history for editing.  File: gdb.info, Node: Command Settings, Next: Completion, Prev: Command Syntax, Up: Commands 3.2 Command Settings ==================== Many commands change their behavior according to command-specific variables or settings. These settings can be changed with the `set' subcommands. For example, the `print' command (*note Examining Data: Data.) prints arrays differently depending on settings changeable with the commands `set print elements NUMBER-OF-ELEMENTS' and `set print array-indexes', among others. You can change these settings to your preference in the gdbinit files loaded at GDB startup. *Note Startup::. The settings can also be changed interactively during the debugging session. For example, to change the limit of array elements to print, you can do the following: (gdb) set print elements 10 (gdb) print some_array $1 = {0, 10, 20, 30, 40, 50, 60, 70, 80, 90...} The above `set print elements 10' command changes the number of elements to print from the default of 200 to 10. If you only intend this limit of 10 to be used for printing `some_array', then you must restore the limit back to 200, with `set print elements 200'. Some commands allow overriding settings with command options. For example, the `print' command supports a number of options that allow overriding relevant global print settings as set by `set print' subcommands. *Note print options::. The example above could be rewritten as: (gdb) print -elements 10 -- some_array $1 = {0, 10, 20, 30, 40, 50, 60, 70, 80, 90...} Alternatively, you can use the `with' command to change a setting temporarily, for the duration of a command invocation. `with SETTING [VALUE] [-- COMMAND]' `w SETTING [VALUE] [-- COMMAND]' Temporarily set SETTING to VALUE for the duration of COMMAND. SETTING is any setting you can change with the `set' subcommands. VALUE is the value to assign to `setting' while running `command'. If no COMMAND is provided, the last command executed is repeated. If a COMMAND is provided, it must be preceded by a double dash (`--') separator. This is required because some settings accept free-form arguments, such as expressions or filenames. For example, the command (gdb) with print array on -- print some_array is equivalent to the following 3 commands: (gdb) set print array on (gdb) print some_array (gdb) set print array off The `with' command is particularly useful when you want to override a setting while running user-defined commands, or commands defined in Python or Guile. *Note Extending GDB: Extending GDB. (gdb) with print pretty on -- my_complex_command To change several settings for the same command, you can nest `with' commands. For example, `with language ada -- with print elements 10' temporarily changes the language to Ada and sets a limit of 10 elements to print for arrays and strings.  File: gdb.info, Node: Completion, Next: Filename Arguments, Prev: Command Settings, Up: Commands 3.3 Command Completion ====================== GDB can fill in the rest of a word in a command for you, if there is only one possibility; it can also show you what the valid possibilities are for the next word in a command, at any time. This works for GDB commands, GDB subcommands, command options, and the names of symbols in your program. Press the key whenever you want GDB to fill out the rest of a word. If there is only one possibility, GDB fills in the word, and waits for you to finish the command (or press to enter it). For example, if you type (gdb) info bre GDB fills in the rest of the word `breakpoints', since that is the only `info' subcommand beginning with `bre': (gdb) info breakpoints You can either press at this point, to run the `info breakpoints' command, or backspace and enter something else, if `breakpoints' does not look like the command you expected. (If you were sure you wanted `info breakpoints' in the first place, you might as well just type immediately after `info bre', to exploit command abbreviations rather than command completion). If there is more than one possibility for the next word when you press , GDB sounds a bell. You can either supply more characters and try again, or just press a second time; GDB displays all the possible completions for that word. For example, you might want to set a breakpoint on a subroutine whose name begins with `make_', but when you type `b make_' GDB just sounds the bell. Typing again displays all the function names in your program that begin with those characters, for example: (gdb) b make_ GDB sounds bell; press again, to see: make_a_section_from_file make_environ make_abs_section make_function_type make_blockvector make_pointer_type make_cleanup make_reference_type make_command make_symbol_completion_list (gdb) b make_ After displaying the available possibilities, GDB copies your partial input (`b make_' in the example) so you can finish the command. If the command you are trying to complete expects either a keyword or a number to follow, then `NUMBER' will be shown among the available completions, for example: (gdb) print -elements NUMBER unlimited (gdb) print -elements Here, the option expects a number (e.g., `100'), not literal `NUMBER'. Such metasyntactical arguments are always presented in uppercase. If you just want to see the list of alternatives in the first place, you can press `M-?' rather than pressing twice. `M-?' means ` ?'. You can type this either by holding down a key designated as the shift on your keyboard (if there is one) while typing `?', or as followed by `?'. If the number of possible completions is large, GDB will print as much of the list as it has collected, as well as a message indicating that the list may be truncated. (gdb) b m main <... the rest of the possible completions ...> *** List may be truncated, max-completions reached. *** (gdb) b m This behavior can be controlled with the following commands: `set max-completions LIMIT' `set max-completions unlimited' Set the maximum number of completion candidates. GDB will stop looking for more completions once it collects this many candidates. This is useful when completing on things like function names as collecting all the possible candidates can be time consuming. The default value is 200. A value of zero disables tab-completion. Note that setting either no limit or a very large limit can make completion slow. `show max-completions' Show the maximum number of candidates that GDB will collect and show during completion. Sometimes the string you need, while logically a "word", may contain parentheses or other characters that GDB normally excludes from its notion of a word. To permit word completion to work in this situation, you may enclose words in `'' (single quote marks) in GDB commands. A likely situation where you might need this is in typing an expression that involves a C++ symbol name with template parameters. This is because when completing expressions, GDB treats the `<' character as word delimiter, assuming that it's the less-than comparison operator (*note C and C++ Operators: C Operators.). For example, when you want to call a C++ template function interactively using the `print' or `call' commands, you may need to distinguish whether you mean the version of `name' that was specialized for `int', `name()', or the version that was specialized for `float', `name()'. To use the word-completion facilities in this situation, type a single quote `'' at the beginning of the function name. This alerts GDB that it may need to consider more information than usual when you press or `M-?' to request word completion: (gdb) p 'func() func() (gdb) p 'func< When setting breakpoints however (*note Location Specifications::), you don't usually need to type a quote before the function name, because GDB understands that you want to set a breakpoint on a function: (gdb) b func() func() (gdb) b func< This is true even in the case of typing the name of C++ overloaded functions (multiple definitions of the same function, distinguished by argument type). For example, when you want to set a breakpoint you don't need to distinguish whether you mean the version of `name' that takes an `int' parameter, `name(int)', or the version that takes a `float' parameter, `name(float)'. (gdb) b bubble(M-? bubble(int) bubble(double) (gdb) b bubble(douM-? bubble(double) See *Note quoting names:: for a description of other scenarios that require quoting. For more information about overloaded functions, see *Note C++ Expressions: C Plus Plus Expressions. You can use the command `set overload-resolution off' to disable overload resolution; see *Note GDB Features for C++: Debugging C Plus Plus. When completing in an expression which looks up a field in a structure, GDB also tries(1) to limit completions to the field names available in the type of the left-hand-side: (gdb) p gdb_stdout.M-? magic to_fputs to_rewind to_data to_isatty to_write to_delete to_put to_write_async_safe to_flush to_read This is because the `gdb_stdout' is a variable of the type `struct ui_file' that is defined in GDB sources as follows: struct ui_file { int *magic; ui_file_flush_ftype *to_flush; ui_file_write_ftype *to_write; ui_file_write_async_safe_ftype *to_write_async_safe; ui_file_fputs_ftype *to_fputs; ui_file_read_ftype *to_read; ui_file_delete_ftype *to_delete; ui_file_isatty_ftype *to_isatty; ui_file_rewind_ftype *to_rewind; ui_file_put_ftype *to_put; void *to_data; } ---------- Footnotes ---------- (1) The completer can be confused by certain kinds of invalid expressions. Also, it only examines the static type of the expression, not the dynamic type.  File: gdb.info, Node: Filename Arguments, Next: Command Options, Prev: Completion, Up: Commands 3.4 Filenames As Command Arguments ================================== When passing filenames (or directory names) as arguments to a command, if the filename argument does not include any whitespace, double quotes, or single quotes, then for all commands the filename can be written as a simple string, for example: (gdb) file /path/to/some/file If the filename does include whitespace, double quotes, or single quotes, then GDB has two approaches for how these filenames should be formatted; which format to use depends on which command is being used. Most GDB commands don't require, or support, quoting and escaping. These commands treat any text after the command name, that is not a command option (*note Command Options::), as the filename, even if the filename contains whitespace or quote characters. In the following example the user is adding `/path/that contains/two spaces/' to the auto-load safe-path (*note add-auto-load-safe-path::): (gdb) add-auto-load-safe-path /path/that contains/two spaces/ A small number of commands require that filenames containing whitespace or quote characters are either quoted, or have the special characters escaped with a backslash. Commands that support this style are marked as such in the manual, any command not marked as accepting quoting and escaping of its filename argument, does not accept this filename argument style. For example, to load the file `/path/with spaces/to/a file' with the `file' command (*note Commands to Specify Files: Files.), you can escape the whitespace characters with a backslash: (gdb) file /path/with\ spaces/to/a\ file Alternatively the entire filename can be wrapped in either single or double quotes, in which case no backlsashes are needed, for example: (gdb) symbol-file "/path/with spaces/to/a file" (gdb) exec-file '/path/with spaces/to/a file' It is possible to include a quote character within a quoted filename by escaping it with a backslash, for example, within a filename surrounded by double quotes, a double quote character should be escaped with a backslash, but a single quote character should not be escaped. Within a single quoted string a single quote character needs to be escaped, but a double quote character does not. A literal backslash character can also be included by escaping it with a backslash.  File: gdb.info, Node: Command Options, Next: Help, Prev: Filename Arguments, Up: Commands 3.5 Command options =================== Some commands accept options starting with a leading dash. For example, `print -pretty'. Similarly to command names, you can abbreviate a GDB option to the first few letters of the option name, if that abbreviation is unambiguous, and you can also use the key to get GDB to fill out the rest of a word in an option (or to show you the alternatives available, if there is more than one possibility). Some commands take raw input as argument. For example, the print command processes arbitrary expressions in any of the languages supported by GDB. With such commands, because raw input may start with a leading dash that would be confused with an option or any of its abbreviations, e.g. `print -p' (short for `print -pretty' or printing negative `p'?), if you specify any command option, then you must use a double-dash (`--') delimiter to indicate the end of options. Some options are described as accepting an argument which can be either `on' or `off'. These are known as "boolean options". Similarly to boolean settings commands--`on' and `off' are the typical values, but any of `1', `yes' and `enable' can also be used as "true" value, and any of `0', `no' and `disable' can also be used as "false" value. You can also omit a "true" value, as it is implied by default. For example, these are equivalent: (gdb) print -object on -pretty off -element unlimited -- *myptr (gdb) p -o -p 0 -e u -- *myptr You can discover the set of options some command accepts by completing on `-' after the command name. For example: (gdb) print - -address -max-depth -object -static-members -array -memory-tag-violations -pretty -symbol -array-indexes -nibbles -raw-values -union -elements -null-stop -repeats -vtbl Completion will in some cases guide you with a suggestion of what kind of argument an option expects. For example: (gdb) print -elements NUMBER unlimited Here, the option expects a number (e.g., `100'), not literal `NUMBER'. Such metasyntactical arguments are always presented in uppercase. (For more on using the `print' command, see *Note Examining Data: Data.)  File: gdb.info, Node: Help, Prev: Command Options, Up: Commands 3.6 Getting Help ================ You can always ask GDB itself for information on its commands, using the command `help'. `help' `h' You can use `help' (abbreviated `h') with no arguments to display a short list of named classes of commands: (gdb) help List of classes of commands: aliases -- User-defined aliases of other commands breakpoints -- Making program stop at certain points data -- Examining data files -- Specifying and examining files internals -- Maintenance commands obscure -- Obscure features running -- Running the program stack -- Examining the stack status -- Status inquiries support -- Support facilities tracepoints -- Tracing of program execution without stopping the program user-defined -- User-defined commands Type "help" followed by a class name for a list of commands in that class. Type "help" followed by command name for full documentation. Command name abbreviations are allowed if unambiguous. (gdb) `help CLASS' Using one of the general help classes as an argument, you can get a list of the individual commands in that class. If a command has aliases, the aliases are given after the command name, separated by commas. If an alias has default arguments, the full definition of the alias is given after the first line. For example, here is the help display for the class `status': (gdb) help status Status inquiries. List of commands: info, inf, i -- Generic command for showing things about the program being debugged info address, iamain -- Describe where symbol SYM is stored. alias iamain = info address main info all-registers -- List of all registers and their contents, for selected stack frame. ... show, info set -- Generic command for showing things about the debugger Type "help" followed by command name for full documentation. Command name abbreviations are allowed if unambiguous. (gdb) `help COMMAND' With a command name as `help' argument, GDB displays a short paragraph on how to use that command. If that command has one or more aliases, GDB will display a first line with the command name and all its aliases separated by commas. This first line will be followed by the full definition of all aliases having default arguments. When asking the help for an alias, the documentation for the aliased command is shown. A user-defined alias can optionally be documented using the `document' command (*note document: Define.). GDB then considers this alias as different from the aliased command: this alias is not listed in the aliased command help output, and asking help for this alias will show the documentation provided for the alias instead of the documentation of the aliased command. `apropos [-v] REGEXP' The `apropos' command searches through all of the GDB commands and aliases, and their documentation, for the regular expression specified in ARGS. It prints out all matches found. The optional flag `-v', which stands for `verbose', indicates to output the full documentation of the matching commands and highlight the parts of the documentation matching REGEXP. For example: apropos alias results in: alias -- Define a new command that is an alias of an existing command aliases -- User-defined aliases of other commands while apropos -v cut.*thread apply results in the below output, where `cut for 'thread apply' is highlighted if styling is enabled. taas -- Apply a command to all threads (ignoring errors and empty output). Usage: taas COMMAND shortcut for 'thread apply all -s COMMAND' tfaas -- Apply a command to all frames of all threads (ignoring errors and empty output). Usage: tfaas COMMAND shortcut for 'thread apply all -s frame apply all -s COMMAND' `complete ARGS' The `complete ARGS' command lists all the possible completions for the beginning of a command. Use ARGS to specify the beginning of the command you want completed. For example: complete i results in: if ignore info inspect This is intended for use by GNU Emacs. In addition to `help', you can use the GDB commands `info' and `show' to inquire about the state of your program, or the state of GDB itself. Each command supports many topics of inquiry; this manual introduces each of them in the appropriate context. The listings under `info' and under `show' in the Command, Variable, and Function Index point to all the sub-commands. *Note Command and Variable Index::. `info' This command (abbreviated `i') is for describing the state of your program. For example, you can show the arguments passed to a function with `info args', list the registers currently in use with `info registers', or list the breakpoints you have set with `info breakpoints'. You can get a complete list of the `info' sub-commands with `help info'. `set' You can assign the result of an expression to an environment variable with `set'. For example, you can set the GDB prompt to a $-sign with `set prompt $'. `show' In contrast to `info', `show' is for describing the state of GDB itself. You can change most of the things you can `show', by using the related command `set'; for example, you can control what number system is used for displays with `set radix', or simply inquire which is currently in use with `show radix'. To display all the settable parameters and their current values, you can use `show' with no arguments; you may also use `info set'. Both commands produce the same display. Here are several miscellaneous `show' subcommands, all of which are exceptional in lacking corresponding `set' commands: `show version' Show what version of GDB is running. You should include this information in GDB bug-reports. If multiple versions of GDB are in use at your site, you may need to determine which version of GDB you are running; as GDB evolves, new commands are introduced, and old ones may wither away. Also, many system vendors ship variant versions of GDB, and there are variant versions of GDB in GNU/Linux distributions as well. The version number is the same as the one announced when you start GDB. `show copying' `info copying' Display information about permission for copying GDB. `show warranty' `info warranty' Display the GNU "NO WARRANTY" statement, or a warranty, if your version of GDB comes with one. `show configuration' Display detailed information about the way GDB was configured when it was built. This displays the optional arguments passed to the `configure' script and also configuration parameters detected automatically by `configure'. When reporting a GDB bug (*note GDB Bugs::), it is important to include this information in your report.  File: gdb.info, Node: Running, Next: Stopping, Prev: Commands, Up: Top 4 Running Programs Under GDB **************************** When you run a program under GDB, you must first generate debugging information when you compile it. You may start GDB with its arguments, if any, in an environment of your choice. If you are doing native debugging, you may redirect your program's input and output, debug an already running process, or kill a child process. * Menu: * Compilation:: Compiling for debugging * Starting:: Starting your program * Arguments:: Your program's arguments * Environment:: Your program's environment * Working Directory:: Your program's working directory * Input/Output:: Your program's input and output * Attach:: Debugging an already-running process * Kill Process:: Killing the child process * Inferiors Connections and Programs:: Debugging multiple inferiors connections and programs * Threads:: Debugging programs with multiple threads * Forks:: Debugging forks * Checkpoint/Restart:: Setting a _bookmark_ to return to later  File: gdb.info, Node: Compilation, Next: Starting, Up: Running 4.1 Compiling for Debugging =========================== In order to debug a program effectively, you need to generate debugging information when you compile it. This debugging information is stored in the object file; it describes the data type of each variable or function and the correspondence between source line numbers and addresses in the executable code. To request debugging information, specify the `-g' option when you run the compiler. Programs that are to be shipped to your customers are compiled with optimizations, using the `-O' compiler option. However, some compilers are unable to handle the `-g' and `-O' options together. Using those compilers, you cannot generate optimized executables containing debugging information. GCC, the GNU C/C++ compiler, supports `-g' with or without `-O', making it possible to debug optimized code. We recommend that you _always_ use `-g' whenever you compile a program. You may think your program is correct, but there is no sense in pushing your luck. For more information, see *Note Optimized Code::. Older versions of the GNU C compiler permitted a variant option `-gg' for debugging information. GDB no longer supports this format; if your GNU C compiler has this option, do not use it. GDB knows about preprocessor macros and can show you their expansion (*note Macros::). Most compilers do not include information about preprocessor macros in the debugging information if you specify the `-g' flag alone. Version 3.1 and later of GCC, the GNU C compiler, provides macro information if you are using the DWARF debugging format, and specify the option `-g3'. *Note Options for Debugging Your Program or GCC: (gcc)Debugging Options, for more information on GCC options affecting debug information. You will have the best debugging experience if you use the latest version of the DWARF debugging format that your compiler supports. DWARF is currently the most expressive and best supported debugging format in GDB.  File: gdb.info, Node: Starting, Next: Arguments, Prev: Compilation, Up: Running 4.2 Starting your Program ========================= `run' `r' Use the `run' command to start your program under GDB. You must first specify the program name with an argument to GDB (*note Getting In and Out of GDB: Invocation.), or by using the `file' or `exec-file' command (*note Commands to Specify Files: Files.). If you are running your program in an execution environment that supports processes, `run' creates an inferior process and makes that process run your program. In some environments without processes, `run' jumps to the start of your program. Other targets, like `remote', are always running. If you get an error message like this one: The "remote" target does not support "run". Try "help target" or "continue". then use `continue' to run your program. You may need `load' first (*note load::). The execution of a program is affected by certain information it receives from its superior. GDB provides ways to specify this information, which you must do _before_ starting your program. (You can change it after starting your program, but such changes only affect your program the next time you start it.) This information may be divided into four categories: The _arguments._ Specify the arguments to give your program as the arguments of the `run' command. If a shell is available on your target, the shell is used to pass the arguments, so that you may use normal conventions (such as wildcard expansion or variable substitution) in describing the arguments. In Unix systems, you can control which shell is used with the `SHELL' environment variable. If you do not define `SHELL', GDB uses the default shell (`/bin/sh'). You can disable use of any shell with the `set startup-with-shell' command (see below for details). The _environment._ Your program normally inherits its environment from GDB, but you can use the GDB commands `set environment' and `unset environment' to change parts of the environment that affect your program. *Note Your Program's Environment: Environment. The _working directory._ You can set your program's working directory with the command `set cwd'. If you do not set any working directory with this command, your program will inherit GDB's working directory if native debugging, or the remote server's working directory if remote debugging. *Note Your Program's Working Directory: Working Directory. The _standard input and output._ Your program normally uses the same device for standard input and standard output as GDB is using. You can redirect input and output in the `run' command line, or you can use the `tty' command to set a different device for your program. *Note Your Program's Input and Output: Input/Output. _Warning:_ While input and output redirection work, you cannot use pipes to pass the output of the program you are debugging to another program; if you attempt this, GDB is likely to wind up debugging the wrong program. When you issue the `run' command, your program begins to execute immediately. *Note Stopping and Continuing: Stopping, for discussion of how to arrange for your program to stop. Once your program has stopped, you may call functions in your program, using the `print' or `call' commands. *Note Examining Data: Data. If the modification time of your symbol file has changed since the last time GDB read its symbols, GDB discards its symbol table, and reads it again. When it does this, GDB tries to retain your current breakpoints. `start' The name of the main procedure can vary from language to language. With C or C++, the main procedure name is always `main', but other languages such as Ada do not require a specific name for their main procedure. The debugger provides a convenient way to start the execution of the program and to stop at the beginning of the main procedure, depending on the language used. The `start' command does the equivalent of setting a temporary breakpoint at the beginning of the main procedure and then invoking the `run' command. Some programs contain an "elaboration" phase where some startup code is executed before the main procedure is called. This depends on the languages used to write your program. In C++, for instance, constructors for static and global objects are executed before `main' is called. It is therefore possible that the debugger stops before reaching the main procedure. However, the temporary breakpoint will remain to halt execution. Specify the arguments to give to your program as arguments to the `start' command. These arguments will be given verbatim to the underlying `run' command. Note that the same arguments will be reused if no argument is provided during subsequent calls to `start' or `run'. It is sometimes necessary to debug the program during elaboration. In these cases, using the `start' command would stop the execution of your program too late, as the program would have already completed the elaboration phase. Under these circumstances, either insert breakpoints in your elaboration code before running your program or use the `starti' command. `starti' The `starti' command does the equivalent of setting a temporary breakpoint at the first instruction of a program's execution and then invoking the `run' command. For programs containing an elaboration phase, the `starti' command will stop execution at the start of the elaboration phase. `set exec-wrapper WRAPPER' `show exec-wrapper' `unset exec-wrapper' When `exec-wrapper' is set, the specified wrapper is used to launch programs for debugging. GDB starts your program with a shell command of the form `exec WRAPPER PROGRAM'. Quoting is added to PROGRAM and its arguments, but not to WRAPPER, so you should add quotes if appropriate for your shell. The wrapper runs until it executes your program, and then GDB takes control. You can use any program that eventually calls `execve' with its arguments as a wrapper. Several standard Unix utilities do this, e.g. `env' and `nohup'. Any Unix shell script ending with `exec "$@@"' will also work. For example, you can use `env' to pass an environment variable to the debugged program, without setting the variable in your shell's environment: (gdb) set exec-wrapper env 'LD_PRELOAD=libtest.so' (gdb) run This command is available when debugging locally on most targets, excluding DJGPP, Cygwin, MS Windows, and QNX Neutrino. `set startup-with-shell' `set startup-with-shell on' `set startup-with-shell off' `show startup-with-shell' On Unix systems, by default, if a shell is available on your target, GDB) uses it to start your program. Arguments of the `run' command are passed to the shell, which does variable substitution, expands wildcard characters and performs redirection of I/O. In some circumstances, it may be useful to disable such use of a shell, for example, when debugging the shell itself or diagnosing startup failures such as: (gdb) run Starting program: ./a.out During startup program terminated with signal SIGSEGV, Segmentation fault. which indicates the shell or the wrapper specified with `exec-wrapper' crashed, not your program. Most often, this is caused by something odd in your shell's non-interactive mode initialization file--such as `.cshrc' for C-shell, $`.zshenv' for the Z shell, or the file specified in the `BASH_ENV' environment variable for BASH. `set auto-connect-native-target' `set auto-connect-native-target on' `set auto-connect-native-target off' `show auto-connect-native-target' By default, if the current inferior is not connected to any target yet (e.g., with `target remote'), the `run' command starts your program as a native process under GDB, on your local machine. If you're sure you don't want to debug programs on your local machine, you can tell GDB to not connect to the native target automatically with the `set auto-connect-native-target off' command. If `on', which is the default, and if the current inferior is not connected to a target already, the `run' command automatically connects to the native target, if one is available. If `off', and if the current inferior is not connected to a target already, the `run' command fails with an error: (gdb) run Don't know how to run. Try "help target". If the current inferior is already connected to a target, GDB always uses it with the `run' command. In any case, you can explicitly connect to the native target with the `target native' command. For example, (gdb) set auto-connect-native-target off (gdb) run Don't know how to run. Try "help target". (gdb) target native (gdb) run Starting program: ./a.out [Inferior 1 (process 10421) exited normally] In case you connected explicitly to the `native' target, GDB remains connected even if all inferiors exit, ready for the next `run' command. Use the `disconnect' command to disconnect. Examples of other commands that likewise respect the `auto-connect-native-target' setting: `attach', `info proc', `info os'. `set disable-randomization' `set disable-randomization on' This option (enabled by default in GDB) will turn off the native randomization of the virtual address space of the started program. This option is useful for multiple debugging sessions to make the execution better reproducible and memory addresses reusable across debugging sessions. This feature is implemented only on certain targets, including GNU/Linux. On GNU/Linux you can get the same behavior using (gdb) set exec-wrapper setarch `uname -m` -R `set disable-randomization off' Leave the behavior of the started executable unchanged. Some bugs rear their ugly heads only when the program is loaded at certain addresses. If your bug disappears when you run the program under GDB, that might be because GDB by default disables the address randomization on platforms, such as GNU/Linux, which do that for stand-alone programs. Use `set disable-randomization off' to try to reproduce such elusive bugs. On targets where it is available, virtual address space randomization protects the programs against certain kinds of security attacks. In these cases the attacker needs to know the exact location of a concrete executable code. Randomizing its location makes it impossible to inject jumps misusing a code at its expected addresses. Prelinking shared libraries provides a startup performance advantage but it makes addresses in these libraries predictable for privileged processes by having just unprivileged access at the target system. Reading the shared library binary gives enough information for assembling the malicious code misusing it. Still even a prelinked shared library can get loaded at a new random address just requiring the regular relocation process during the startup. Shared libraries not already prelinked are always loaded at a randomly chosen address. Position independent executables (PIE) contain position independent code similar to the shared libraries and therefore such executables get loaded at a randomly chosen address upon startup. PIE executables always load even already prelinked shared libraries at a random address. You can build such executable using `gcc -fPIE -pie'. Heap (malloc storage), stack and custom mmap areas are always placed randomly (as long as the randomization is enabled). `show disable-randomization' Show the current setting of the explicit disable of the native randomization of the virtual address space of the started program.  File: gdb.info, Node: Arguments, Next: Environment, Prev: Starting, Up: Running 4.3 Your Program's Arguments ============================ The arguments to your program can be specified by the arguments of the `run' command. They are passed to a shell, which expands wildcard characters and performs redirection of I/O, and thence to your program. Your `SHELL' environment variable (if it exists) specifies what shell GDB uses. If you do not define `SHELL', GDB uses the default shell (`/bin/sh' on Unix). On non-Unix systems, the program is usually invoked directly by GDB, which emulates I/O redirection via the appropriate system calls, and the wildcard characters are expanded by the startup code of the program, not by the shell. `run' with no arguments uses the same arguments used by the previous `run', or those set by the `set args' command. `set args' Specify the arguments to be used the next time your program is run. If `set args' has no arguments, `run' executes your program with no arguments. Once you have run your program with arguments, using `set args' before the next `run' is the only way to run it again without arguments. `show args' Show the arguments to give your program when it is started.  File: gdb.info, Node: Environment, Next: Working Directory, Prev: Arguments, Up: Running 4.4 Your Program's Environment ============================== The "environment" consists of a set of environment variables and their values. Environment variables conventionally record such things as your user name, your home directory, your terminal type, and your search path for programs to run. Usually you set up environment variables with the shell and they are inherited by all the other programs you run. When debugging, it can be useful to try running your program with a modified environment without having to start GDB over again. `path DIRECTORY' Add DIRECTORY to the front of the `PATH' environment variable (the search path for executables) that will be passed to your program. The value of `PATH' used by GDB does not change. You may specify several directory names, separated by whitespace or by a system-dependent separator character (`:' on Unix, `;' on MS-DOS and MS-Windows). If DIRECTORY is already in the path, it is moved to the front, so it is searched sooner. You can use the string `$cwd' to refer to whatever is the current working directory at the time GDB searches the path. If you use `.' instead, it refers to the directory where you executed the `path' command. GDB replaces `.' in the DIRECTORY argument (with the current path) before adding DIRECTORY to the search path. `show paths' Display the list of search paths for executables (the `PATH' environment variable). `show environment [VARNAME]' Print the value of environment variable VARNAME to be given to your program when it starts. If you do not supply VARNAME, print the names and values of all environment variables to be given to your program. You can abbreviate `environment' as `env'. `set environment VARNAME [=VALUE]' Set environment variable VARNAME to VALUE. The value changes for your program (and the shell GDB uses to launch it), not for GDB itself. The VALUE may be any string; the values of environment variables are just strings, and any interpretation is supplied by your program itself. The VALUE parameter is optional; if it is eliminated, the variable is set to a null value. For example, this command: set env USER = foo tells the debugged program, when subsequently run, that its user is named `foo'. (The spaces around `=' are used for clarity here; they are not actually required.) Note that on Unix systems, GDB runs your program via a shell, which also inherits the environment set with `set environment'. If necessary, you can avoid that by using the `env' program as a wrapper instead of using `set environment'. *Note set exec-wrapper::, for an example doing just that. Environment variables that are set by the user are also transmitted to `gdbserver' to be used when starting the remote inferior. *note QEnvironmentHexEncoded::. `unset environment VARNAME' Remove variable VARNAME from the environment to be passed to your program. This is different from `set env VARNAME ='; `unset environment' removes the variable from the environment, rather than assigning it an empty value. Environment variables that are unset by the user are also unset on `gdbserver' when starting the remote inferior. *note QEnvironmentUnset::. _Warning:_ On Unix systems, GDB runs your program using the shell indicated by your `SHELL' environment variable if it exists (or `/bin/sh' if not). If your `SHELL' variable names a shell that runs an initialization file when started non-interactively--such as `.cshrc' for C-shell, $`.zshenv' for the Z shell, or the file specified in the `BASH_ENV' environment variable for BASH--any variables you set in that file affect your program. You may wish to move setting of environment variables to files that are only run when you sign on, such as `.login' or `.profile'.  File: gdb.info, Node: Working Directory, Next: Input/Output, Prev: Environment, Up: Running 4.5 Your Program's Working Directory ==================================== Each time you start your program with `run', the inferior will be initialized with the current working directory specified by the `set cwd' command. If no directory has been specified by this command, then the inferior will inherit GDB's current working directory as its working directory if native debugging, or it will inherit the remote server's current working directory if remote debugging. `set cwd [DIRECTORY]' Set the inferior's working directory to DIRECTORY, which will be `glob'-expanded in order to resolve tildes (`~'). If no argument has been specified, the command clears the setting and resets it to an empty state. This setting has no effect on GDB's working directory, and it only takes effect the next time you start the inferior. The `~' in DIRECTORY is a short for the "home directory", usually pointed to by the `HOME' environment variable. On MS-Windows, if `HOME' is not defined, GDB uses the concatenation of `HOMEDRIVE' and `HOMEPATH' as fallback. You can also change GDB's current working directory by using the `cd' command. *Note cd command::. `show cwd' Show the inferior's working directory. If no directory has been specified by `set cwd', then the default inferior's working directory is the same as GDB's working directory. `cd [DIRECTORY]' Set the GDB working directory to DIRECTORY. If not given, DIRECTORY uses `'~''. The GDB working directory serves as a default for the commands that specify files for GDB to operate on. *Note Commands to Specify Files: Files. *Note set cwd command::. `pwd' Print the GDB working directory. It is generally impossible to find the current working directory of the process being debugged (since a program can change its directory during its run). If you work on a system where GDB supports the `info proc' command (*note Process Information::), you can use the `info proc' command to find out the current working directory of the debuggee.  File: gdb.info, Node: Input/Output, Next: Attach, Prev: Working Directory, Up: Running 4.6 Your Program's Input and Output =================================== By default, the program you run under GDB does input and output to the same terminal that GDB uses. GDB switches the terminal to its own terminal modes to interact with you, but it records the terminal modes your program was using and switches back to them when you continue running your program. `info terminal' Displays information recorded by GDB about the terminal modes your program is using. You can redirect your program's input and/or output using shell redirection with the `run' command. For example, run > outfile starts your program, diverting its output to the file `outfile'. Another way to specify where your program should do input and output is with the `tty' command. This command accepts a file name as argument, and causes this file to be the default for future `run' commands. It also resets the controlling terminal for the child process, for future `run' commands. For example, tty /dev/ttyb directs that processes started with subsequent `run' commands default to do input and output on the terminal `/dev/ttyb' and have that as their controlling terminal. An explicit redirection in `run' overrides the `tty' command's effect on the input/output device, but not its effect on the controlling terminal. When you use the `tty' command or redirect input in the `run' command, only the input _for your program_ is affected. The input for GDB still comes from your terminal. `tty' is an alias for `set inferior-tty'. You can use the `show inferior-tty' command to tell GDB to display the name of the terminal that will be used for future runs of your program. `set inferior-tty [ TTY ]' Set the tty for the program being debugged to TTY. Omitting TTY restores the default behavior, which is to use the same terminal as GDB. `show inferior-tty' Show the current tty for the program being debugged.  File: gdb.info, Node: Attach, Next: Kill Process, Prev: Input/Output, Up: Running 4.7 Debugging an Already-running Process ======================================== `attach PROCESS-ID' This command attaches to a running process--one that was started outside GDB. (`info files' shows your active targets.) The command takes as argument a process ID. The usual way to find out the PROCESS-ID of a Unix process is with the `ps' utility, or with the `jobs -l' shell command. `attach' does not repeat if you press a second time after executing the command. To use `attach', your program must be running in an environment which supports processes; for example, `attach' does not work for programs on bare-board targets that lack an operating system. You must also have permission to send the process a signal. When you use `attach', the debugger finds the program running in the process first by looking in the current working directory, then (if the program is not found) by using the source file search path (*note Specifying Source Directories: Source Path.). You can also use the `file' command to load the program. *Note Commands to Specify Files: Files. If the debugger can determine that the executable file running in the process it is attaching to does not match the current exec-file loaded by GDB, the option `exec-file-mismatch' specifies how to handle the mismatch. GDB tries to compare the files by comparing their build IDs (*note build ID::), if available. `set exec-file-mismatch `ask|warn|off'' Whether to detect mismatch between the current executable file loaded by GDB and the executable file used to start the process. If `ask', the default, display a warning and ask the user whether to load the process executable file; if `warn', just display a warning; if `off', don't attempt to detect a mismatch. If the user confirms loading the process executable file, then its symbols will be loaded as well. `show exec-file-mismatch' Show the current value of `exec-file-mismatch'. The first thing GDB does after arranging to debug the specified process is to stop it. You can examine and modify an attached process with all the GDB commands that are ordinarily available when you start processes with `run'. You can insert breakpoints; you can step and continue; you can modify storage. If you would rather the process continue running, you may use the `continue' command after attaching GDB to the process. `detach' When you have finished debugging the attached process, you can use the `detach' command to release it from GDB control. Detaching the process continues its execution. After the `detach' command, that process and GDB become completely independent once more, and you are ready to `attach' another process or start one with `run'. `detach' does not repeat if you press again after executing the command. If you exit GDB while you have an attached process, you detach that process. If you use the `run' command, you kill that process. By default, GDB asks for confirmation if you try to do either of these things; you can control whether or not you need to confirm by using the `set confirm' command (*note Optional Warnings and Messages: Messages/Warnings.).  File: gdb.info, Node: Kill Process, Next: Inferiors Connections and Programs, Prev: Attach, Up: Running 4.8 Killing the Child Process ============================= `kill' Kill the child process in which your program is running under GDB. This command is useful if you wish to debug a core dump instead of a running process. GDB ignores any core dump file while your program is running. On some operating systems, a program cannot be executed outside GDB while you have breakpoints set on it inside GDB. You can use the `kill' command in this situation to permit running your program outside the debugger. The `kill' command is also useful if you wish to recompile and relink your program, since on many systems it is impossible to modify an executable file while it is running in a process. In this case, when you next type `run', GDB notices that the file has changed, and reads the symbol table again (while trying to preserve your current breakpoint settings).  File: gdb.info, Node: Inferiors Connections and Programs, Next: Threads, Prev: Kill Process, Up: Running 4.9 Debugging Multiple Inferiors Connections and Programs ========================================================= GDB lets you run and debug multiple programs in a single session. In addition, GDB on some systems may let you run several programs simultaneously (otherwise you have to exit from one before starting another). On some systems GDB may even let you debug several programs simultaneously on different remote systems. In the most general case, you can have multiple threads of execution in each of multiple processes, launched from multiple executables, running on different machines. GDB represents the state of each program execution with an object called an "inferior". An inferior typically corresponds to a process, but is more general and applies also to targets that do not have processes. Inferiors may be created before a process runs, and may be retained after a process exits. Inferiors have unique identifiers that are different from process ids. Usually each inferior will also have its own distinct address space, although some embedded targets may have several inferiors running in different parts of a single address space. Each inferior may in turn have multiple threads running in it. The commands `info inferiors' and `info connections', which will be introduced below, accept a space-separated "ID list" as their argument specifying one or more elements on which to operate. A list element can be either a single non-negative number, like `5', or an ascending range of such numbers, like `5-7'. A list can consist of any combination of such elements, even duplicates or overlapping ranges are valid. E.g. `1 4-6 5 4-4' or `1 2 4-7'. To find out what inferiors exist at any moment, use `info inferiors': `info inferiors' Print a list of all inferiors currently being managed by GDB. By default all inferiors are printed, but the ID list ID... can be used to limit the display to just the requested inferiors. GDB displays for each inferior (in this order): 1. the inferior number assigned by GDB 2. the target system's inferior identifier 3. the target connection the inferior is bound to, including the unique connection number assigned by GDB, and the protocol used by the connection. 4. the name of the executable the inferior is running. An asterisk `*' preceding the GDB inferior number indicates the current inferior. For example, (gdb) info inferiors Num Description Connection Executable * 1 process 3401 1 (native) goodbye 2 process 2307 2 (extended-remote host:10000) hello To get information about the current inferior, use `inferior': `inferior' Shows information about the current inferior. For example, (gdb) inferior [Current inferior is 1 [process 3401] (helloworld)] To find out what open target connections exist at any moment, use `info connections': `info connections' Print a list of all open target connections currently being managed by GDB. By default all connections are printed, but the ID list ID... can be used to limit the display to just the requested connections. GDB displays for each connection (in this order): 1. the connection number assigned by GDB. 2. the protocol used by the connection. 3. a textual description of the protocol used by the connection. An asterisk `*' preceding the connection number indicates the connection of the current inferior. For example, (gdb) info connections Num What Description * 1 extended-remote host:10000 Extended remote serial target in gdb-specific protocol 2 native Native process 3 core Local core dump file To switch focus between inferiors, use the `inferior' command: `inferior INFNO' Make inferior number INFNO the current inferior. The argument INFNO is the inferior number assigned by GDB, as shown in the first field of the `info inferiors' display. The debugger convenience variable `$_inferior' contains the number of the current inferior. You may find this useful in writing breakpoint conditional expressions, command scripts, and so forth. *Note Convenience Variables: Convenience Vars, for general information on convenience variables. You can get multiple executables into a debugging session via the `add-inferior' and `clone-inferior' commands. On some systems GDB can add inferiors to the debug session automatically by following calls to `fork' and `exec'. To remove inferiors from the debugging session use the `remove-inferiors' command. `add-inferior [ -copies N ] [ -exec EXECUTABLE ] [-no-connection ]' Adds N inferiors to be run using EXECUTABLE as the executable; N defaults to 1. If no executable is specified, the inferiors begins empty, with no program. You can still assign or change the program assigned to the inferior at any time by using the `file' command with the executable name as its argument. By default, the new inferior begins connected to the same target connection as the current inferior. For example, if the current inferior was connected to `gdbserver' with `target remote', then the new inferior will be connected to the same `gdbserver' instance. The `-no-connection' option starts the new inferior with no connection yet. You can then for example use the `target remote' command to connect to some other `gdbserver' instance, use `run' to spawn a local program, etc. `clone-inferior [ -copies N ] [ INFNO ]' Adds N inferiors ready to execute the same program as inferior INFNO; N defaults to 1, and INFNO defaults to the number of the current inferior. This command copies the values of the ARGS, INFERIOR-TTY and CWD properties from the current inferior to the new one. It also propagates changes the user made to environment variables using the `set environment' and `unset environment' commands. This is a convenient command when you want to run another instance of the inferior you are debugging. (gdb) info inferiors Num Description Connection Executable * 1 process 29964 1 (native) helloworld (gdb) clone-inferior Added inferior 2. 1 inferiors added. (gdb) info inferiors Num Description Connection Executable * 1 process 29964 1 (native) helloworld 2 1 (native) helloworld You can now simply switch focus to inferior 2 and run it. `remove-inferiors INFNO...' Removes the inferior or inferiors INFNO.... It is not possible to remove an inferior that is running with this command. For those, use the `kill' or `detach' command first. To quit debugging one of the running inferiors that is not the current inferior, you can either detach from it by using the `detach inferior' command (allowing it to run independently), or kill it using the `kill inferiors' command: `detach inferior INFNO...' Detach from the inferior or inferiors identified by GDB inferior number(s) INFNO.... Note that the inferior's entry still stays on the list of inferiors shown by `info inferiors', but its Description will show `'. `kill inferiors INFNO...' Kill the inferior or inferiors identified by GDB inferior number(s) INFNO.... Note that the inferior's entry still stays on the list of inferiors shown by `info inferiors', but its Description will show `'. After the successful completion of a command such as `detach', `detach inferiors', `kill' or `kill inferiors', or after a normal process exit, the inferior is still valid and listed with `info inferiors', ready to be restarted. To be notified when inferiors are started or exit under GDB's control use `set print inferior-events': `set print inferior-events' `set print inferior-events on' `set print inferior-events off' The `set print inferior-events' command allows you to enable or disable printing of messages when GDB notices that new inferiors have started or that inferiors have exited or have been detached. By default, these messages will be printed. `show print inferior-events' Show whether messages will be printed when GDB detects that inferiors have started, exited or have been detached. Many commands will work the same with multiple programs as with a single program: e.g., `print myglobal' will simply display the value of `myglobal' in the current inferior. Occasionally, when debugging GDB itself, it may be useful to get more info about the relationship of inferiors, programs, address spaces in a debug session. You can do that with the `maint info program-spaces' command. `maint info program-spaces' Print a list of all program spaces currently being managed by GDB. GDB displays for each program space (in this order): 1. the program space number assigned by GDB 2. the name of the executable loaded into the program space, with e.g., the `file' command. 3. the name of the core file loaded into the program space, with e.g., the `core-file' command. An asterisk `*' preceding the GDB program space number indicates the current program space. In addition, below each program space line, GDB prints extra information that isn't suitable to display in tabular form. For example, the list of inferiors bound to the program space. (gdb) maint info program-spaces Id Executable Core File * 1 hello 2 goodbye Bound inferiors: ID 1 (process 21561) Here we can see that no inferior is running the program `hello', while `process 21561' is running the program `goodbye'. On some targets, it is possible that multiple inferiors are bound to the same program space. The most common example is that of debugging both the parent and child processes of a `vfork' call. For example, (gdb) maint info program-spaces Id Executable Core File * 1 vfork-test Bound inferiors: ID 2 (process 18050), ID 1 (process 18045) Here, both inferior 2 and inferior 1 are running in the same program space as a result of inferior 1 having executed a `vfork' call. * Menu: * Inferior-Specific Breakpoints:: Controlling breakpoints  File: gdb.info, Node: Inferior-Specific Breakpoints, Up: Inferiors Connections and Programs 4.9.1 Inferior-Specific Breakpoints ----------------------------------- When debugging multiple inferiors, you can choose whether to set breakpoints for all inferiors, or for a particular inferior. `break LOCSPEC inferior INFERIOR-ID' `break LOCSPEC inferior INFERIOR-ID if ...' LOCSPEC specifies a code location or locations in your program. *Note Location Specifications::, for details. Use the qualifier `inferior INFERIOR-ID' with a breakpoint command to specify that you only want GDB to stop when a particular inferior reaches this breakpoint. The INFERIOR-ID specifier is one of the inferior identifiers assigned by GDB, shown in the first column of the `info inferiors' output. If you do not specify `inferior INFERIOR-ID' when you set a breakpoint, the breakpoint applies to _all_ inferiors of your program. You can use the `inferior' qualifier on conditional breakpoints as well; in this case, place `inferior INFERIOR-ID' before or after the breakpoint condition, like this: (gdb) break frik.c:13 inferior 2 if bartab > lim Inferior-specific breakpoints are automatically deleted when the corresponding inferior is removed from GDB. For example: (gdb) remove-inferiors 2 Inferior-specific breakpoint 3 deleted - inferior 2 has been removed. A breakpoint can't be both inferior-specific and thread-specific (*note Thread-Specific Breakpoints::), or task-specific (*note Ada Tasks::); using more than one of the `inferior', `thread', or `task' keywords when creating a breakpoint will give an error.  File: gdb.info, Node: Threads, Next: Forks, Prev: Inferiors Connections and Programs, Up: Running 4.10 Debugging Programs with Multiple Threads ============================================= In some operating systems, such as GNU/Linux and Solaris, a single program may have more than one "thread" of execution. The precise semantics of threads differ from one operating system to another, but in general the threads of a single program are akin to multiple processes--except that they share one address space (that is, they can all examine and modify the same variables). On the other hand, each thread has its own registers and execution stack, and perhaps private memory. GDB provides these facilities for debugging multi-thread programs: * automatic notification of new threads * `thread THREAD-ID', a command to switch among threads * `info threads', a command to inquire about existing threads * `thread apply [THREAD-ID-LIST | all] ARGS', a command to apply a command to a list of threads * thread-specific breakpoints * `set print thread-events', which controls printing of messages on thread start and exit. * `set libthread-db-search-path PATH', which lets the user specify which `libthread_db' to use if the default choice isn't compatible with the program. The GDB thread debugging facility allows you to observe all threads while your program runs--but whenever GDB takes control, one thread in particular is always the focus of debugging. This thread is called the "current thread". Debugging commands show program information from the perspective of the current thread. Whenever GDB detects a new thread in your program, it displays the target system's identification for the thread with a message in the form `[New SYSTAG]', where SYSTAG is a thread identifier whose form varies depending on the particular system. For example, on GNU/Linux, you might see [New Thread 0x41e02940 (LWP 25582)] when GDB notices a new thread. In contrast, on other systems, the SYSTAG is simply something like `process 368', with no further qualifier. For debugging purposes, GDB associates its own thread number --always a single integer--with each thread of an inferior. This number is unique between all threads of an inferior, but not unique between threads of different inferiors. You can refer to a given thread in an inferior using the qualified INFERIOR-NUM.THREAD-NUM syntax, also known as "qualified thread ID", with INFERIOR-NUM being the inferior number and THREAD-NUM being the thread number of the given inferior. For example, thread `2.3' refers to thread number 3 of inferior 2. If you omit INFERIOR-NUM (e.g., `thread 3'), then GDB infers you're referring to a thread of the current inferior. Until you create a second inferior, GDB does not show the INFERIOR-NUM part of thread IDs, even though you can always use the full INFERIOR-NUM.THREAD-NUM form to refer to threads of inferior 1, the initial inferior. Some commands accept a space-separated "thread ID list" as argument. A list element can be: 1. A thread ID as shown in the first field of the `info threads' display, with or without an inferior qualifier. E.g., `2.1' or `1'. 2. A range of thread numbers, again with or without an inferior qualifier, as in INF.THR1-THR2 or THR1-THR2. E.g., `1.2-4' or `2-4'. 3. All threads of an inferior, specified with a star wildcard, with or without an inferior qualifier, as in INF.`*' (e.g., `1.*') or `*'. The former refers to all threads of the given inferior, and the latter form without an inferior qualifier refers to all threads of the current inferior. For example, if the current inferior is 1, and inferior 7 has one thread with ID 7.1, the thread list `1 2-3 4.5 6.7-9 7.*' includes threads 1 to 3 of inferior 1, thread 5 of inferior 4, threads 7 to 9 of inferior 6 and all threads of inferior 7. That is, in expanded qualified form, the same as `1.1 1.2 1.3 4.5 6.7 6.8 6.9 7.1'. In addition to a _per-inferior_ number, each thread is also assigned a unique _global_ number, also known as "global thread ID", a single integer. Unlike the thread number component of the thread ID, no two threads have the same global ID, even when you're debugging multiple inferiors. From GDB's perspective, a process always has at least one thread. In other words, GDB assigns a thread number to the program's "main thread" even if the program is not multi-threaded. The debugger convenience variables `$_thread' and `$_gthread' contain, respectively, the per-inferior thread number and the global thread number of the current thread. You may find this useful in writing breakpoint conditional expressions, command scripts, and so forth. The convenience variable `$_inferior_thread_count' contains the number of live threads in the current inferior. *Note Convenience Variables: Convenience Vars, for general information on convenience variables. When running in non-stop mode (*note Non-Stop Mode::), where new threads can be created, and existing threads exit, at any time, `$_inferior_thread_count' could return a different value each time it is evaluated. If GDB detects the program is multi-threaded, it augments the usual message about stopping at a breakpoint with the ID and name of the thread that hit the breakpoint. Thread 2 "client" hit Breakpoint 1, send_message () at client.c:68 Likewise when the program receives a signal: Thread 1 "main" received signal SIGINT, Interrupt. `info threads [-gid] [THREAD-ID-LIST]' Display information about one or more threads. With no arguments displays information about all threads. You can specify the list of threads that you want to display using the thread ID list syntax (*note thread ID lists::). GDB displays for each thread (in this order): 1. the per-inferior thread number assigned by GDB 2. the global thread number assigned by GDB, if the `-gid' option was specified 3. the target system's thread identifier (SYSTAG) 4. the thread's name, if one is known. A thread can either be named by the user (see `thread name', below), or, in some cases, by the program itself. 5. the current stack frame summary for that thread An asterisk `*' to the left of the GDB thread number indicates the current thread. For example, (gdb) info threads Id Target Id Frame * 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) 2 process 35 thread 23 0x34e5 in sigpause () 3 process 35 thread 27 0x34e5 in sigpause () at threadtest.c:68 If you're debugging multiple inferiors, GDB displays thread IDs using the qualified INFERIOR-NUM.THREAD-NUM format. Otherwise, only THREAD-NUM is shown. If you specify the `-gid' option, GDB displays a column indicating each thread's global thread ID: (gdb) info threads Id GId Target Id Frame 1.1 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8) 1.2 3 process 35 thread 23 0x34e5 in sigpause () 1.3 4 process 35 thread 27 0x34e5 in sigpause () * 2.1 2 process 65 thread 1 main (argc=1, argv=0x7ffffff8) On Solaris, you can display more information about user threads with a Solaris-specific command: `maint info sol-threads' Display info on Solaris user threads. `thread THREAD-ID' Make thread ID THREAD-ID the current thread. The command argument THREAD-ID is the GDB thread ID, as shown in the first field of the `info threads' display, with or without an inferior qualifier (e.g., `2.1' or `1'). GDB responds by displaying the system identifier of the thread you selected, and its current stack frame summary: (gdb) thread 2 [Switching to thread 2 (Thread 0xb7fdab70 (LWP 12747))] #0 some_function (ignore=0x0) at example.c:8 8 printf ("hello\n"); As with the `[New ...]' message, the form of the text after `Switching to' depends on your system's conventions for identifying threads. `thread apply [THREAD-ID-LIST | all [-ascending]] [FLAG]... COMMAND' The `thread apply' command allows you to apply the named COMMAND to one or more threads. Specify the threads that you want affected using the thread ID list syntax (*note thread ID lists::), or specify `all' to apply to all threads. To apply a command to all threads in descending order, type `thread apply all COMMAND'. To apply a command to all threads in ascending order, type `thread apply all -ascending COMMAND'. The FLAG arguments control what output to produce and how to handle errors raised when applying COMMAND to a thread. FLAG must start with a `-' directly followed by one letter in `qcs'. If several flags are provided, they must be given individually, such as `-c -q'. By default, GDB displays some thread information before the output produced by COMMAND, and an error raised during the execution of a COMMAND will abort `thread apply'. The following flags can be used to fine-tune this behavior: `-c' The flag `-c', which stands for `continue', causes any errors in COMMAND to be displayed, and the execution of `thread apply' then continues. `-s' The flag `-s', which stands for `silent', causes any errors or empty output produced by a COMMAND to be silently ignored. That is, the execution continues, but the thread information and errors are not printed. `-q' The flag `-q' (`quiet') disables printing the thread information. Flags `-c' and `-s' cannot be used together. `taas [OPTION]... COMMAND' Shortcut for `thread apply all -s [OPTION]... COMMAND'. Applies COMMAND on all threads, ignoring errors and empty output. The `taas' command accepts the same options as the `thread apply all' command. *Note thread apply all::. `tfaas [OPTION]... COMMAND' Shortcut for `thread apply all -s -- frame apply all -s [OPTION]... COMMAND'. Applies COMMAND on all frames of all threads, ignoring errors and empty output. Note that the flag `-s' is specified twice: The first `-s' ensures that `thread apply' only shows the thread information of the threads for which `frame apply' produces some output. The second `-s' is needed to ensure that `frame apply' shows the frame information of a frame only if the COMMAND successfully produced some output. It can for example be used to print a local variable or a function argument without knowing the thread or frame where this variable or argument is, using: (gdb) tfaas p some_local_var_i_do_not_remember_where_it_is The `tfaas' command accepts the same options as the `frame apply' command. *Note frame apply: Frame Apply. `thread name [NAME]' This command assigns a name to the current thread. If no argument is given, any existing user-specified name is removed. The thread name appears in the `info threads' display. On some systems, such as GNU/Linux, GDB is able to determine the name of the thread as given by the OS. On these systems, a name specified with `thread name' will override the system-give name, and removing the user-specified name will cause GDB to once again display the system-specified name. `thread find [REGEXP]' Search for and display thread ids whose name or SYSTAG matches the supplied regular expression. As well as being the complement to the `thread name' command, this command also allows you to identify a thread by its target SYSTAG. For instance, on GNU/Linux, the target SYSTAG is the LWP id. (gdb) thread find 26688 Thread 4 has target id 'Thread 0x41e02940 (LWP 26688)' (gdb) info thread 4 Id Target Id Frame 4 Thread 0x41e02940 (LWP 26688) 0x00000031ca6cd372 in select () `set print thread-events' `set print thread-events on' `set print thread-events off' The `set print thread-events' command allows you to enable or disable printing of messages when GDB notices that new threads have started or that threads have exited. By default, these messages will be printed if detection of these events is supported by the target. Note that these messages cannot be disabled on all targets. `show print thread-events' Show whether messages will be printed when GDB detects that threads have started and exited. *Note Stopping and Starting Multi-thread Programs: Thread Stops, for more information about how GDB behaves when you stop and start programs with multiple threads. *Note Setting Watchpoints: Set Watchpoints, for information about watchpoints in programs with multiple threads. `set libthread-db-search-path [PATH]' If this variable is set, PATH is a colon-separated list of directories GDB will use to search for `libthread_db'. If you omit PATH, `libthread-db-search-path' will be reset to its default value (`$sdir:$pdir' on GNU/Linux and Solaris systems). Internally, the default value comes from the `LIBTHREAD_DB_SEARCH_PATH' macro. On GNU/Linux and Solaris systems, GDB uses a "helper" `libthread_db' library to obtain information about threads in the inferior process. GDB will use `libthread-db-search-path' to find `libthread_db'. GDB also consults first if inferior specific thread debugging library loading is enabled by `set auto-load libthread-db' (*note libthread_db.so.1 file::). A special entry `$sdir' for `libthread-db-search-path' refers to the default system directories that are normally searched for loading shared libraries. The `$sdir' entry is the only kind not needing to be enabled by `set auto-load libthread-db' (*note libthread_db.so.1 file::). A special entry `$pdir' for `libthread-db-search-path' refers to the directory from which `libpthread' was loaded in the inferior process. For any `libthread_db' library GDB finds in above directories, GDB attempts to initialize it with the current inferior process. If this initialization fails (which could happen because of a version mismatch between `libthread_db' and `libpthread'), GDB will unload `libthread_db', and continue with the next directory. If none of `libthread_db' libraries initialize successfully, GDB will issue a warning and thread debugging will be disabled. Setting `libthread-db-search-path' is currently implemented only on some platforms. `show libthread-db-search-path' Display current libthread_db search path. `set debug libthread-db' `show debug libthread-db' Turns on or off display of `libthread_db'-related events. Use `1' to enable, `0' to disable. `set debug threads [on|off]' `show debug threads' When `on' GDB will print additional messages when threads are created and deleted.  File: gdb.info, Node: Forks, Next: Checkpoint/Restart, Prev: Threads, Up: Running 4.11 Debugging Forks ==================== On most systems, GDB has no special support for debugging programs which create additional processes using the `fork' function. When a program forks, GDB will continue to debug the parent process and the child process will run unimpeded. If you have set a breakpoint in any code which the child then executes, the child will get a `SIGTRAP' signal which (unless it catches the signal) will cause it to terminate. However, if you want to debug the child process there is a workaround which isn't too painful. Put a call to `sleep' in the code which the child process executes after the fork. It may be useful to sleep only if a certain environment variable is set, or a certain file exists, so that the delay need not occur when you don't want to run GDB on the child. While the child is sleeping, use the `ps' program to get its process ID. Then tell GDB (a new invocation of GDB if you are also debugging the parent process) to attach to the child process (*note Attach::). From that point on you can debug the child process just like any other process which you attached to. On some systems, GDB provides support for debugging programs that create additional processes using the `fork' or `vfork' functions. On GNU/Linux platforms, this feature is supported with kernel version 2.5.46 and later. The fork debugging commands are supported in native mode and when connected to `gdbserver' in either `target remote' mode or `target extended-remote' mode. By default, when a program forks, GDB will continue to debug the parent process and the child process will run unimpeded. If you want to follow the child process instead of the parent process, use the command `set follow-fork-mode'. `set follow-fork-mode MODE' Set the debugger response to a program call of `fork' or `vfork'. A call to `fork' or `vfork' creates a new process. The MODE argument can be: `parent' The original process is debugged after a fork. The child process runs unimpeded. This is the default. `child' The new process is debugged after a fork. The parent process runs unimpeded. `show follow-fork-mode' Display the current debugger response to a `fork' or `vfork' call. On Linux, if you want to debug both the parent and child processes, use the command `set detach-on-fork'. `set detach-on-fork MODE' Tells gdb whether to detach one of the processes after a fork, or retain debugger control over them both. `on' The child process (or parent process, depending on the value of `follow-fork-mode') will be detached and allowed to run independently. This is the default. `off' Both processes will be held under the control of GDB. One process (child or parent, depending on the value of `follow-fork-mode') is debugged as usual, while the other is held suspended. `show detach-on-fork' Show whether detach-on-fork mode is on/off. If you choose to set `detach-on-fork' mode off, then GDB will retain control of all forked processes (including nested forks). You can list the forked processes under the control of GDB by using the `info inferiors' command, and switch from one fork to another by using the `inferior' command (*note Debugging Multiple Inferiors Connections and Programs: Inferiors Connections and Programs.). To quit debugging one of the forked processes, you can either detach from it by using the `detach inferiors' command (allowing it to run independently), or kill it using the `kill inferiors' command. *Note Debugging Multiple Inferiors Connections and Programs: Inferiors Connections and Programs. If you ask to debug a child process and a `vfork' is followed by an `exec', GDB executes the new target up to the first breakpoint in the new target. If you have a breakpoint set on `main' in your original program, the breakpoint will also be set on the child process's `main'. On some systems, when a child process is spawned by `vfork', you cannot debug the child or parent until an `exec' call completes. If you issue a `run' command to GDB after an `exec' call executes, the new target restarts. To restart the parent process, use the `file' command with the parent executable name as its argument. By default, after an `exec' call executes, GDB discards the symbols of the previous executable image. You can change this behaviour with the `set follow-exec-mode' command. `set follow-exec-mode MODE' Set debugger response to a program call of `exec'. An `exec' call replaces the program image of a process. `follow-exec-mode' can be: `new' GDB creates a new inferior and rebinds the process to this new inferior. The program the process was running before the `exec' call can be restarted afterwards by restarting the original inferior. For example: (gdb) info inferiors (gdb) info inferior Id Description Executable * 1 prog1 (gdb) run process 12020 is executing new program: prog2 Program exited normally. (gdb) info inferiors Id Description Executable 1 prog1 * 2 prog2 `same' GDB keeps the process bound to the same inferior. The new executable image replaces the previous executable loaded in the inferior. Restarting the inferior after the `exec' call, with e.g., the `run' command, restarts the executable the process was running after the `exec' call. This is the default mode. For example: (gdb) info inferiors Id Description Executable * 1 prog1 (gdb) run process 12020 is executing new program: prog2 Program exited normally. (gdb) info inferiors Id Description Executable * 1 prog2 `follow-exec-mode' is supported in native mode and `target extended-remote' mode. You can use the `catch' command to make GDB stop whenever a `fork', `vfork', or `exec' call is made. *Note Setting Catchpoints: Set Catchpoints.  File: gdb.info, Node: Checkpoint/Restart, Prev: Forks, Up: Running 4.12 Setting a _Bookmark_ to Return to Later ============================================ On certain operating systems(1), GDB is able to save a "snapshot" of a program's state, called a "checkpoint", and come back to it later. Returning to a checkpoint effectively undoes everything that has happened in the program since the `checkpoint' was saved. This includes changes in memory, registers, and even (within some limits) system state. Effectively, it is like going back in time to the moment when the checkpoint was saved. Thus, if you're stepping thru a program and you think you're getting close to the point where things go wrong, you can save a checkpoint. Then, if you accidentally go too far and miss the critical statement, instead of having to restart your program from the beginning, you can just go back to the checkpoint and start again from there. This can be especially useful if it takes a lot of time or steps to reach the point where you think the bug occurs. To use the `checkpoint'/`restart' method of debugging: `checkpoint' Save a snapshot of the debugged program's current execution state. The `checkpoint' command takes no arguments, but each checkpoint is assigned a small integer id, similar to a breakpoint id. `info checkpoints' List the checkpoints that have been saved in the current debugging session. For each checkpoint, the following information will be listed: `Checkpoint ID' `Process ID' `Code Address' `Source line, or label' `restart CHECKPOINT-ID' Restore the program state that was saved as checkpoint number CHECKPOINT-ID. All program variables, registers, stack frames etc. will be returned to the values that they had when the checkpoint was saved. In essence, gdb will "wind back the clock" to the point in time when the checkpoint was saved. Note that breakpoints, GDB variables, command history etc. are not affected by restoring a checkpoint. In general, a checkpoint only restores things that reside in the program being debugged, not in the debugger. `delete checkpoint CHECKPOINT-ID' Delete the previously-saved checkpoint identified by CHECKPOINT-ID. Returning to a previously saved checkpoint will restore the user state of the program being debugged, plus a significant subset of the system (OS) state, including file pointers. It won't "un-write" data from a file, but it will rewind the file pointer to the previous location, so that the previously written data can be overwritten. For files opened in read mode, the pointer will also be restored so that the previously read data can be read again. Of course, characters that have been sent to a printer (or other external device) cannot be "snatched back", and characters received from eg. a serial device can be removed from internal program buffers, but they cannot be "pushed back" into the serial pipeline, ready to be received again. Similarly, the actual contents of files that have been changed cannot be restored (at this time). However, within those constraints, you actually can "rewind" your program to a previously saved point in time, and begin debugging it again -- and you can change the course of events so as to debug a different execution path this time. Finally, there is one bit of internal program state that will be different when you return to a checkpoint -- the program's process id. Each checkpoint will have a unique process id (or PID), and each will be different from the program's original PID. If your program has saved a local copy of its process id, this could potentially pose a problem. 4.12.1 A Non-obvious Benefit of Using Checkpoints ------------------------------------------------- On some systems such as GNU/Linux, address space randomization is performed on new processes for security reasons. This makes it difficult or impossible to set a breakpoint, or watchpoint, on an absolute address if you have to restart the program, since the absolute location of a symbol will change from one execution to the next. A checkpoint, however, is an _identical_ copy of a process. Therefore if you create a checkpoint at (eg.) the start of main, and simply return to that checkpoint instead of restarting the process, you can avoid the effects of address randomization and your symbols will all stay in the same place. ---------- Footnotes ---------- (1) Currently, only GNU/Linux.  File: gdb.info, Node: Stopping, Next: Reverse Execution, Prev: Running, Up: Top 5 Stopping and Continuing ************************* The principal purposes of using a debugger are so that you can stop your program before it terminates; or so that, if your program runs into trouble, you can investigate and find out why. Inside GDB, your program may stop for any of several reasons, such as a signal, a breakpoint, or reaching a new line after a GDB command such as `step'. You may then examine and change variables, set new breakpoints or remove old ones, and then continue execution. Usually, the messages shown by GDB provide ample explanation of the status of your program--but you can also explicitly request this information at any time. `info program' Display information about the status of your program: whether it is running or not, what process it is, and why it stopped. * Menu: * Breakpoints:: Breakpoints, watchpoints, tracepoints, and catchpoints * Continuing and Stepping:: Resuming execution * Skipping Over Functions and Files:: Skipping over functions and files * Signals:: Signals * Thread Stops:: Stopping and starting multi-thread programs  File: gdb.info, Node: Breakpoints, Next: Continuing and Stepping, Up: Stopping 5.1 Breakpoints, Watchpoints, and Catchpoints ============================================= A "breakpoint" makes your program stop whenever a certain point in the program is reached. For each breakpoint, you can add conditions to control in finer detail whether your program stops. You can set breakpoints with the `break' command and its variants (*note Setting Breakpoints: Set Breaks.), to specify the place where your program should stop by line number, function name or exact address in the program. On some systems, you can set breakpoints in shared libraries before the executable is run. A "watchpoint" is a special breakpoint that stops your program when the value of an expression changes. The expression may be a value of a variable, or it could involve values of one or more variables combined by operators, such as `a + b'. This is sometimes called "data breakpoints". You must use a different command to set watchpoints (*note Setting Watchpoints: Set Watchpoints.), but aside from that, you can manage a watchpoint like any other breakpoint: you enable, disable, and delete both breakpoints and watchpoints using the same commands. You can arrange to have values from your program displayed automatically whenever GDB stops at a breakpoint. *Note Automatic Display: Auto Display. A "catchpoint" is another special breakpoint that stops your program when a certain kind of event occurs, such as the throwing of a C++ exception or the loading of a library. As with watchpoints, you use a different command to set a catchpoint (*note Setting Catchpoints: Set Catchpoints.), but aside from that, you can manage a catchpoint like any other breakpoint. (To stop when your program receives a signal, use the `handle' command; see *Note Signals: Signals.) GDB assigns a number to each breakpoint, watchpoint, or catchpoint when you create it; these numbers are successive integers starting with one. In many of the commands for controlling various features of breakpoints you use the breakpoint number to say which breakpoint you want to change. Each breakpoint may be "enabled" or "disabled"; if disabled, it has no effect on your program until you enable it again. Some GDB commands accept a space-separated list of breakpoints on which to operate. A list element can be either a single breakpoint number, like `5', or a range of such numbers, like `5-7'. When a breakpoint list is given to a command, all breakpoints in that list are operated on. * Menu: * Set Breaks:: Setting breakpoints * Set Watchpoints:: Setting watchpoints * Set Catchpoints:: Setting catchpoints * Delete Breaks:: Deleting breakpoints * Disabling:: Disabling breakpoints * Conditions:: Break conditions * Break Commands:: Breakpoint command lists * Dynamic Printf:: Dynamic printf * Save Breakpoints:: How to save breakpoints in a file * Static Probe Points:: Listing static probe points * Error in Breakpoints:: ``Cannot insert breakpoints'' * Breakpoint-related Warnings:: ``Breakpoint address adjusted...''  File: gdb.info, Node: Set Breaks, Next: Set Watchpoints, Up: Breakpoints 5.1.1 Setting Breakpoints ------------------------- Breakpoints are set with the `break' command (abbreviated `b'). The debugger convenience variable `$bpnum' records the number of the breakpoint you've set most recently: (gdb) b main Breakpoint 1 at 0x11c6: file zeoes.c, line 24. (gdb) p $bpnum $1 = 1 A breakpoint may be mapped to multiple code locations for example with inlined functions, Ada generics, C++ templates or overloaded function names. GDB then indicates the number of code locations in the breakpoint command output: (gdb) b some_func Breakpoint 2 at 0x1179: some_func. (3 locations) (gdb) p $bpnum $2 = 2 (gdb) When your program stops on a breakpoint, the convenience variables `$_hit_bpnum' and `$_hit_locno' are respectively set to the number of the encountered breakpoint and the number of the breakpoint's code location: Thread 1 "zeoes" hit Breakpoint 2.1, some_func () at zeoes.c:8 8 printf("some func\n"); (gdb) p $_hit_bpnum $5 = 2 (gdb) p $_hit_locno $6 = 1 (gdb) Note that `$_hit_bpnum' and `$bpnum' are not equivalent: `$_hit_bpnum' is set to the breakpoint number last hit, while `$bpnum' is set to the breakpoint number last set. If the encountered breakpoint has only one code location, `$_hit_locno' is set to 1: Breakpoint 1, main (argc=1, argv=0x7fffffffe018) at zeoes.c:24 24 if (argc > 1) (gdb) p $_hit_bpnum $3 = 1 (gdb) p $_hit_locno $4 = 1 (gdb) The `$_hit_bpnum' and `$_hit_locno' variables can typically be used in a breakpoint command list. (*note Breakpoint Command Lists: Break Commands.). For example, as part of the breakpoint command list, you can disable completely the encountered breakpoint using `disable $_hit_bpnum' or disable the specific encountered breakpoint location using `disable $_hit_bpnum.$_hit_locno'. If a breakpoint has only one location, `$_hit_locno' is set to 1 and the commands `disable $_hit_bpnum' and `disable $_hit_bpnum.$_hit_locno' both disable the breakpoint. You can also define aliases to easily disable the last hit location or last hit breakpoint: (gdb) alias lld = disable $_hit_bpnum.$_hit_locno (gdb) alias lbd = disable $_hit_bpnum `break LOCSPEC' Set a breakpoint at all the code locations in your program that result from resolving the given LOCSPEC. LOCSPEC can specify a function name, a line number, an address of an instruction, and more. *Note Location Specifications::, for the various forms of LOCSPEC. The breakpoint will stop your program just before it executes the instruction at the address of any of the breakpoint's code locations. When using source languages that permit overloading of symbols, such as C++, a function name may refer to more than one symbol, and thus more than one place to break. *Note Ambiguous Expressions: Ambiguous Expressions, for a discussion of that situation. It is also possible to insert a breakpoint that will stop the program only if a specific thread (*note Thread-Specific Breakpoints::), specific inferior (*note Inferior-Specific Breakpoints::), or a specific task (*note Ada Tasks::) hits that breakpoint. `break' When called without any arguments, `break' sets a breakpoint at the next instruction to be executed in the selected stack frame (*note Examining the Stack: Stack.). In any selected frame but the innermost, this makes your program stop as soon as control returns to that frame. This is similar to the effect of a `finish' command in the frame inside the selected frame--except that `finish' does not leave an active breakpoint. If you use `break' without an argument in the innermost frame, GDB stops the next time it reaches the current location; this may be useful inside loops. GDB normally ignores breakpoints when it resumes execution, until at least one instruction has been executed. If it did not do this, you would be unable to proceed past a breakpoint without first disabling the breakpoint. This rule applies whether or not the breakpoint already existed when your program stopped. `break ... if COND' Set a breakpoint with condition COND; evaluate the expression COND each time the breakpoint is reached, and stop only if the value is nonzero--that is, if COND evaluates as true. `...' stands for one of the possible arguments described above (or no argument) specifying where to break. *Note Break Conditions: Conditions, for more information on breakpoint conditions. The breakpoint may be mapped to multiple locations. If the breakpoint condition COND is invalid at some but not all of the locations, the locations for which the condition is invalid are disabled. For example, GDB reports below that two of the three locations are disabled. (gdb) break func if a == 10 warning: failed to validate condition at location 0x11ce, disabling: No symbol "a" in current context. warning: failed to validate condition at location 0x11b6, disabling: No symbol "a" in current context. Breakpoint 1 at 0x11b6: func. (3 locations) Locations that are disabled because of the condition are denoted by an uppercase `N' in the output of the `info breakpoints' command: (gdb) info breakpoints Num Type Disp Enb Address What 1 breakpoint keep y stop only if a == 10 1.1 N* 0x00000000000011b6 in ... 1.2 y 0x00000000000011c2 in ... 1.3 N* 0x00000000000011ce in ... (*): Breakpoint condition is invalid at this location. If the breakpoint condition COND is invalid in the context of _all_ the locations of the breakpoint, GDB refuses to define the breakpoint. For example, if variable `foo' is an undefined variable: (gdb) break func if foo No symbol "foo" in current context. `break ... -force-condition if COND' There may be cases where the condition COND is invalid at all the current locations, but the user knows that it will be valid at a future location; for example, because of a library load. In such cases, by using the `-force-condition' keyword before `if', GDB can be forced to define the breakpoint with the given condition expression instead of refusing it. (gdb) break func -force-condition if foo warning: failed to validate condition at location 1, disabling: No symbol "foo" in current context. warning: failed to validate condition at location 2, disabling: No symbol "foo" in current context. warning: failed to validate condition at location 3, disabling: No symbol "foo" in current context. Breakpoint 1 at 0x1158: test.c:18. (3 locations) This causes all the present locations where the breakpoint would otherwise be inserted, to be disabled, as seen in the example above. However, if there exist locations at which the condition is valid, the `-force-condition' keyword has no effect. `tbreak ARGS' Set a breakpoint enabled only for one stop. The ARGS are the same as for the `break' command, and the breakpoint is set in the same way, but the breakpoint is automatically deleted after the first time your program stops there. *Note Disabling Breakpoints: Disabling. `hbreak ARGS' Set a hardware-assisted breakpoint. The ARGS are the same as for the `break' command and the breakpoint is set in the same way, but the breakpoint requires hardware support and some target hardware may not have this support. The main purpose of this is EPROM/ROM code debugging, so you can set a breakpoint at an instruction without changing the instruction. This can be used with the new trap-generation provided by SPARClite DSU and most x86-based targets. These targets will generate traps when a program accesses some data or instruction address that is assigned to the debug registers. However the hardware breakpoint registers can take a limited number of breakpoints. For example, on the DSU, only two data breakpoints can be set at a time, and GDB will reject this command if more than two are used. Delete or disable unused hardware breakpoints before setting new ones (*note Disabling Breakpoints: Disabling.). *Note Break Conditions: Conditions. For remote targets, you can restrict the number of hardware breakpoints GDB will use, see *Note set remote hardware-breakpoint-limit::. `thbreak ARGS' Set a hardware-assisted breakpoint enabled only for one stop. The ARGS are the same as for the `hbreak' command and the breakpoint is set in the same way. However, like the `tbreak' command, the breakpoint is automatically deleted after the first time your program stops there. Also, like the `hbreak' command, the breakpoint requires hardware support and some target hardware may not have this support. *Note Disabling Breakpoints: Disabling. See also *Note Break Conditions: Conditions. `rbreak REGEX' Set breakpoints on all functions matching the regular expression REGEX. This command sets an unconditional breakpoint on all matches, printing a list of all breakpoints it set. Once these breakpoints are set, they are treated just like the breakpoints set with the `break' command. You can delete them, disable them, or make them conditional the same way as any other breakpoint. In programs using different languages, GDB chooses the syntax to print the list of all breakpoints it sets according to the `set language' value: using `set language auto' (see *Note Set Language Automatically: Automatically.) means to use the language of the breakpoint's function, other values mean to use the manually specified language (see *Note Set Language Manually: Manually.). The syntax of the regular expression is the standard one used with tools like `grep'. Note that this is different from the syntax used by shells, so for instance `foo*' matches all functions that include an `fo' followed by zero or more `o's. There is an implicit `.*' leading and trailing the regular expression you supply, so to match only functions that begin with `foo', use `^foo'. When debugging C++ programs, `rbreak' is useful for setting breakpoints on overloaded functions that are not members of any special classes. The `rbreak' command can be used to set breakpoints in *all* the functions in a program, like this: (gdb) rbreak . `rbreak FILE:REGEX' If `rbreak' is called with a filename qualification, it limits the search for functions matching the given regular expression to the specified FILE. This can be used, for example, to set breakpoints on every function in a given file: (gdb) rbreak file.c:. The colon separating the filename qualifier from the regex may optionally be surrounded by spaces. `info breakpoints [LIST...]' `info break [LIST...]' Print a table of all breakpoints, watchpoints, tracepoints, and catchpoints set and not deleted. Optional argument N means print information only about the specified breakpoint(s) (or watchpoint(s) or tracepoint(s) or catchpoint(s)). For each breakpoint, following columns are printed: _Breakpoint Numbers_ _Type_ Breakpoint, watchpoint, tracepoint, or catchpoint. _Disposition_ Whether the breakpoint is marked to be disabled or deleted when hit. _Enabled or Disabled_ Enabled breakpoints are marked with `y'. `n' marks breakpoints that are not enabled. _Address_ Where the breakpoint is in your program, as a memory address. For a pending breakpoint whose address is not yet known, this field will contain `'. Such breakpoint won't fire until a shared library that has the symbol or line referred by breakpoint is loaded. See below for details. A breakpoint with several locations will have `' in this field--see below for details. _What_ Where the breakpoint is in the source for your program, as a file and line number. For a pending breakpoint, the original string passed to the breakpoint command will be listed as it cannot be resolved until the appropriate shared library is loaded in the future. If a breakpoint is conditional, there are two evaluation modes: "host" and "target". If mode is "host", breakpoint condition evaluation is done by GDB on the host's side. If it is "target", then the condition is evaluated by the target. The `info break' command shows the condition on the line following the affected breakpoint, together with its condition evaluation mode in between parentheses. Breakpoint commands, if any, are listed after that. A pending breakpoint is allowed to have a condition specified for it. The condition is not parsed for validity until a shared library is loaded that allows the pending breakpoint to resolve to a valid location. `info break' with a breakpoint number N as argument lists only that breakpoint. The convenience variable `$_' and the default examining-address for the `x' command are set to the address of the last breakpoint listed (*note Examining Memory: Memory.). `info break' displays a count of the number of times the breakpoint has been hit. This is especially useful in conjunction with the `ignore' command. You can ignore a large number of breakpoint hits, look at the breakpoint info to see how many times the breakpoint was hit, and then run again, ignoring one less than that number. This will get you quickly to the last hit of that breakpoint. For a breakpoints with an enable count (xref) greater than 1, `info break' also displays that count. GDB allows you to set any number of breakpoints at the same place in your program. There is nothing silly or meaningless about this. When the breakpoints are conditional, this is even useful (*note Break Conditions: Conditions.). It is possible that a single logical breakpoint is set at several code locations in your program. *Note Location Specifications::, for examples. A breakpoint with multiple code locations is displayed in the breakpoint table using several rows--one header row, followed by one row for each code location. The header row has `' in the address column. Each code location row contains the actual address, source file, source line and function of its code location. The number column for a code location is of the form BREAKPOINT-NUMBER.LOCATION-NUMBER. For example: Num Type Disp Enb Address What 1 breakpoint keep y stop only if i==1 breakpoint already hit 1 time 1.1 y 0x080486a2 in void foo() at t.cc:8 1.2 y 0x080486ca in void foo() at t.cc:8 You cannot delete the individual locations from a breakpoint. However, each location can be individually enabled or disabled by passing BREAKPOINT-NUMBER.LOCATION-NUMBER as argument to the `enable' and `disable' commands. It's also possible to `enable' and `disable' a range of LOCATION-NUMBER locations using a BREAKPOINT-NUMBER and two LOCATION-NUMBERs, in increasing order, separated by a hyphen, like `BREAKPOINT-NUMBER.LOCATION-NUMBER1-LOCATION-NUMBER2', in which case GDB acts on all the locations in the range (inclusive). Disabling or enabling the parent breakpoint (*note Disabling::) affects all of the locations that belong to that breakpoint. Locations that are enabled while their parent breakpoint is disabled won't trigger a break, and are denoted by `y-' in the `Enb' column. For example: (gdb) info breakpoints Num Type Disp Enb Address What 1 breakpoint keep n 1.1 y- 0x00000000000011b6 in ... 1.2 y- 0x00000000000011c2 in ... 1.3 n 0x00000000000011ce in ... It's quite common to have a breakpoint inside a shared library. Shared libraries can be loaded and unloaded explicitly, and possibly repeatedly, as the program is executed. To support this use case, GDB updates breakpoint locations whenever any shared library is loaded or unloaded. Typically, you would set a breakpoint in a shared library at the beginning of your debugging session, when the library is not loaded, and when the symbols from the library are not available. When you try to set breakpoint, GDB will ask you if you want to set a so called "pending breakpoint"--breakpoint whose address is not yet resolved. After the program is run, whenever a new shared library is loaded, GDB reevaluates all the breakpoints. When a newly loaded shared library contains the symbol or line referred to by some pending breakpoint, that breakpoint is resolved and becomes an ordinary breakpoint. When a library is unloaded, all breakpoints that refer to its symbols or source lines become pending again. This logic works for breakpoints with multiple locations, too. For example, if you have a breakpoint in a C++ template function, and a newly loaded shared library has an instantiation of that template, a new location is added to the list of locations for the breakpoint. Except for having unresolved address, pending breakpoints do not differ from regular breakpoints. You can set conditions or commands, enable and disable them and perform other breakpoint operations. GDB provides some additional commands for controlling what happens when the `break' command cannot resolve the location spec to any code location in your program (*note Location Specifications::): `set breakpoint pending auto' This is the default behavior. When GDB cannot resolve the location spec, it queries you whether a pending breakpoint should be created. `set breakpoint pending on' This indicates that when GDB cannot resolve the location spec, it should create a pending breakpoint without confirmation. `set breakpoint pending off' This indicates that pending breakpoints are not to be created. If GDB cannot resolve the location spec, it aborts the breakpoint creation with an error. This setting does not affect any pending breakpoints previously created. `show breakpoint pending' Show the current behavior setting for creating pending breakpoints. The settings above only affect the `break' command and its variants. Once a breakpoint is set, it will be automatically updated as shared libraries are loaded and unloaded. For some targets, GDB can automatically decide if hardware or software breakpoints should be used, depending on whether the breakpoint address is read-only or read-write. This applies to breakpoints set with the `break' command as well as to internal breakpoints set by commands like `next' and `finish'. For breakpoints set with `hbreak', GDB will always use hardware breakpoints. You can control this automatic behaviour with the following commands: `set breakpoint auto-hw on' This is the default behavior. When GDB sets a breakpoint, it will try to use the target memory map to decide if software or hardware breakpoint must be used. `set breakpoint auto-hw off' This indicates GDB should not automatically select breakpoint type. If the target provides a memory map, GDB will warn when trying to set software breakpoint at a read-only address. GDB normally implements breakpoints by replacing the program code at the breakpoint address with a special instruction, which, when executed, given control to the debugger. By default, the program code is so modified only when the program is resumed. As soon as the program stops, GDB restores the original instructions. This behaviour guards against leaving breakpoints inserted in the target should gdb abrubptly disconnect. However, with slow remote targets, inserting and removing breakpoint can reduce the performance. This behavior can be controlled with the following commands:: `set breakpoint always-inserted off' All breakpoints, including newly added by the user, are inserted in the target only when the target is resumed. All breakpoints are removed from the target when it stops. This is the default mode. `set breakpoint always-inserted on' Causes all breakpoints to be inserted in the target at all times. If the user adds a new breakpoint, or changes an existing breakpoint, the breakpoints in the target are updated immediately. A breakpoint is removed from the target only when breakpoint itself is deleted. GDB handles conditional breakpoints by evaluating these conditions when a breakpoint breaks. If the condition is true, then the process being debugged stops, otherwise the process is resumed. If the target supports evaluating conditions on its end, GDB may download the breakpoint, together with its conditions, to it. This feature can be controlled via the following commands: `set breakpoint condition-evaluation host' This option commands GDB to evaluate the breakpoint conditions on the host's side. Unconditional breakpoints are sent to the target which in turn receives the triggers and reports them back to GDB for condition evaluation. This is the standard evaluation mode. `set breakpoint condition-evaluation target' This option commands GDB to download breakpoint conditions to the target at the moment of their insertion. The target is responsible for evaluating the conditional expression and reporting breakpoint stop events back to GDB whenever the condition is true. Due to limitations of target-side evaluation, some conditions cannot be evaluated there, e.g., conditions that depend on local data that is only known to the host. Examples include conditional expressions involving convenience variables, complex types that cannot be handled by the agent expression parser and expressions that are too long to be sent over to the target, specially when the target is a remote system. In these cases, the conditions will be evaluated by GDB. `set breakpoint condition-evaluation auto' This is the default mode. If the target supports evaluating breakpoint conditions on its end, GDB will download breakpoint conditions to the target (limitations mentioned previously apply). If the target does not support breakpoint condition evaluation, then GDB will fallback to evaluating all these conditions on the host's side. GDB itself sometimes sets breakpoints in your program for special purposes, such as proper handling of `longjmp' (in C programs). These internal breakpoints are assigned negative numbers, starting with `-1'; `info breakpoints' does not display them. You can see these breakpoints with the GDB maintenance command `maint info breakpoints' (*note maint info breakpoints::).  File: gdb.info, Node: Set Watchpoints, Next: Set Catchpoints, Prev: Set Breaks, Up: Breakpoints 5.1.2 Setting Watchpoints ------------------------- You can use a watchpoint to stop execution whenever the value of an expression changes, without having to predict a particular place where this may happen. (This is sometimes called a "data breakpoint".) The expression may be as simple as the value of a single variable, or as complex as many variables combined by operators. Examples include: * A reference to the value of a single variable. * An address cast to an appropriate data type. For example, `*(int *)0x12345678' will watch a 4-byte region at the specified address (assuming an `int' occupies 4 bytes). * An arbitrarily complex expression, such as `a*b + c/d'. The expression can use any operators valid in the program's native language (*note Languages::). You can set a watchpoint on an expression even if the expression can not be evaluated yet. For instance, you can set a watchpoint on `*global_ptr' before `global_ptr' is initialized. GDB will stop when your program sets `global_ptr' and the expression produces a valid value. If the expression becomes valid in some other way than changing a variable (e.g. if the memory pointed to by `*global_ptr' becomes readable as the result of a `malloc' call), GDB may not stop until the next time the expression changes. Depending on your system, watchpoints may be implemented in software or hardware. GDB does software watchpointing by single-stepping your program and testing the variable's value each time, which is hundreds of times slower than normal execution. (But this may still be worth it, to catch errors where you have no clue what part of your program is the culprit.) On some systems, such as most PowerPC or x86-based targets, GDB includes support for hardware watchpoints, which do not slow down the running of your program. `watch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE] [task TASK-ID]' Set a watchpoint for an expression. GDB will break when the expression EXPR is written into by the program and its value changes. The simplest (and the most popular) use of this command is to watch the value of a single variable: (gdb) watch foo If the command includes a `[thread THREAD-ID]' argument, GDB breaks only when the thread identified by THREAD-ID changes the value of EXPR. If any other threads change the value of EXPR, GDB will not break. Note that watchpoints restricted to a single thread in this way only work with Hardware Watchpoints. Similarly, if the `task' argument is given, then the watchpoint will be specific to the indicated Ada task (*note Ada Tasks::). Ordinarily a watchpoint respects the scope of variables in EXPR (see below). The `-location' argument tells GDB to instead watch the memory referred to by EXPR. In this case, GDB will evaluate EXPR, take the address of the result, and watch the memory at that address. The type of the result is used to determine the size of the watched memory. If the expression's result does not have an address, then GDB will print an error. The `[mask MASKVALUE]' argument allows creation of masked watchpoints, if the current architecture supports this feature (e.g., PowerPC Embedded architecture, see *Note PowerPC Embedded::.) A "masked watchpoint" specifies a mask in addition to an address to watch. The mask specifies that some bits of an address (the bits which are reset in the mask) should be ignored when matching the address accessed by the inferior against the watchpoint address. Thus, a masked watchpoint watches many addresses simultaneously--those addresses whose unmasked bits are identical to the unmasked bits in the watchpoint address. The `mask' argument implies `-location'. Examples: (gdb) watch foo mask 0xffff00ff (gdb) watch *0xdeadbeef mask 0xffffff00 `rwatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]' Set a watchpoint that will break when the value of EXPR is read by the program. `awatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]' Set a watchpoint that will break when EXPR is either read from or written into by the program. `info watchpoints [LIST...]' This command prints a list of watchpoints, using the same format as `info break' (*note Set Breaks::). If you watch for a change in a numerically entered address you need to dereference it, as the address itself is just a constant number which will never change. GDB refuses to create a watchpoint that watches a never-changing value: (gdb) watch 0x600850 Cannot watch constant value 0x600850. (gdb) watch *(int *) 0x600850 Watchpoint 1: *(int *) 6293584 GDB sets a "hardware watchpoint" if possible. Hardware watchpoints execute very quickly, and the debugger reports a change in value at the exact instruction where the change occurs. If GDB cannot set a hardware watchpoint, it sets a software watchpoint, which executes more slowly and reports the change in value at the next _statement_, not the instruction, after the change occurs. You can force GDB to use only software watchpoints with the `set can-use-hw-watchpoints 0' command. With this variable set to zero, GDB will never try to use hardware watchpoints, even if the underlying system supports them. (Note that hardware-assisted watchpoints that were set _before_ setting `can-use-hw-watchpoints' to zero will still use the hardware mechanism of watching expression values.) `set can-use-hw-watchpoints' Set whether or not to use hardware watchpoints. `show can-use-hw-watchpoints' Show the current mode of using hardware watchpoints. For remote targets, you can restrict the number of hardware watchpoints GDB will use, see *Note set remote hardware-breakpoint-limit::. When you issue the `watch' command, GDB reports Hardware watchpoint NUM: EXPR if it was able to set a hardware watchpoint. Currently, the `awatch' and `rwatch' commands can only set hardware watchpoints, because accesses to data that don't change the value of the watched expression cannot be detected without examining every instruction as it is being executed, and GDB does not do that currently. If GDB finds that it is unable to set a hardware breakpoint with the `awatch' or `rwatch' command, it will print a message like this: Expression cannot be implemented with read/access watchpoint. Sometimes, GDB cannot set a hardware watchpoint because the data type of the watched expression is wider than what a hardware watchpoint on the target machine can handle. For example, some systems can only watch regions that are up to 4 bytes wide; on such systems you cannot set hardware watchpoints for an expression that yields a double-precision floating-point number (which is typically 8 bytes wide). As a work-around, it might be possible to break the large region into a series of smaller ones and watch them with separate watchpoints. If you set too many hardware watchpoints, GDB might be unable to insert all of them when you resume the execution of your program. Since the precise number of active watchpoints is unknown until such time as the program is about to be resumed, GDB might not be able to warn you about this when you set the watchpoints, and the warning will be printed only when the program is resumed: Hardware watchpoint NUM: Could not insert watchpoint If this happens, delete or disable some of the watchpoints. Watching complex expressions that reference many variables can also exhaust the resources available for hardware-assisted watchpoints. That's because GDB needs to watch every variable in the expression with separately allocated resources. If you call a function interactively using `print' or `call', any watchpoints you have set will be inactive until GDB reaches another kind of breakpoint or the call completes. GDB automatically deletes watchpoints that watch local (automatic) variables, or expressions that involve such variables, when they go out of scope, that is, when the execution leaves the block in which these variables were defined. In particular, when the program being debugged terminates, _all_ local variables go out of scope, and so only watchpoints that watch global variables remain set. If you rerun the program, you will need to set all such watchpoints again. One way of doing that would be to set a code breakpoint at the entry to the `main' function and when it breaks, set all the watchpoints. In multi-threaded programs, watchpoints will detect changes to the watched expression from every thread. _Warning:_ In multi-threaded programs, software watchpoints have only limited usefulness. If GDB creates a software watchpoint, it can only watch the value of an expression _in a single thread_. If you are confident that the expression can only change due to the current thread's activity (and if you are also confident that no other thread can become current), then you can use software watchpoints as usual. However, GDB may not notice when a non-current thread's activity changes the expression. (Hardware watchpoints, in contrast, watch an expression in all threads.) *Note set remote hardware-watchpoint-limit::.  File: gdb.info, Node: Set Catchpoints, Next: Delete Breaks, Prev: Set Watchpoints, Up: Breakpoints 5.1.3 Setting Catchpoints ------------------------- You can use "catchpoints" to cause the debugger to stop for certain kinds of program events, such as C++ exceptions or the loading of a shared library. Use the `catch' command to set a catchpoint. `catch EVENT' Stop when EVENT occurs. The EVENT can be any of the following: `throw [REGEXP]' `rethrow [REGEXP]' `catch [REGEXP]' The throwing, re-throwing, or catching of a C++ exception. If REGEXP is given, then only exceptions whose type matches the regular expression will be caught. The convenience variable `$_exception' is available at an exception-related catchpoint, on some systems. This holds the exception being thrown. There are currently some limitations to C++ exception handling in GDB: * The support for these commands is system-dependent. Currently, only systems using the `gnu-v3' C++ ABI (*note ABI::) are supported. * The regular expression feature and the `$_exception' convenience variable rely on the presence of some SDT probes in `libstdc++'. If these probes are not present, then these features cannot be used. These probes were first available in the GCC 4.8 release, but whether or not they are available in your GCC also depends on how it was built. * The `$_exception' convenience variable is only valid at the instruction at which an exception-related catchpoint is set. * When an exception-related catchpoint is hit, GDB stops at a location in the system library which implements runtime exception support for C++, usually `libstdc++'. You can use `up' (*note Selection::) to get to your code. * If you call a function interactively, GDB normally returns control to you when the function has finished executing. If the call raises an exception, however, the call may bypass the mechanism that returns control to you and cause your program either to abort or to simply continue running until it hits a breakpoint, catches a signal that GDB is listening for, or exits. This is the case even if you set a catchpoint for the exception; catchpoints on exceptions are disabled within interactive calls. *Note Calling::, for information on controlling this with `set unwind-on-terminating-exception'. * You cannot raise an exception interactively. * You cannot install an exception handler interactively. `exception [NAME]' An Ada exception being raised. If an exception name is specified at the end of the command (eg `catch exception Program_Error'), the debugger will stop only when this specific exception is raised. Otherwise, the debugger stops execution when any Ada exception is raised. When inserting an exception catchpoint on a user-defined exception whose name is identical to one of the exceptions defined by the language, the fully qualified name must be used as the exception name. Otherwise, GDB will assume that it should stop on the pre-defined exception rather than the user-defined one. For instance, assuming an exception called `Constraint_Error' is defined in package `Pck', then the command to use to catch such exceptions is `catch exception Pck.Constraint_Error'. The convenience variable `$_ada_exception' holds the address of the exception being thrown. This can be useful when setting a condition for such a catchpoint. `exception unhandled' An exception that was raised but is not handled by the program. The convenience variable `$_ada_exception' is set as for `catch exception'. `handlers [NAME]' An Ada exception being handled. If an exception name is specified at the end of the command (eg `catch handlers Program_Error'), the debugger will stop only when this specific exception is handled. Otherwise, the debugger stops execution when any Ada exception is handled. When inserting a handlers catchpoint on a user-defined exception whose name is identical to one of the exceptions defined by the language, the fully qualified name must be used as the exception name. Otherwise, GDB will assume that it should stop on the pre-defined exception rather than the user-defined one. For instance, assuming an exception called `Constraint_Error' is defined in package `Pck', then the command to use to catch such exceptions handling is `catch handlers Pck.Constraint_Error'. The convenience variable `$_ada_exception' is set as for `catch exception'. `assert' A failed Ada assertion. Note that the convenience variable `$_ada_exception' is _not_ set by this catchpoint. `exec' A call to `exec'. `syscall' `syscall [NAME | NUMBER | group:GROUPNAME | g:GROUPNAME] ...' A call to or return from a system call, a.k.a. "syscall". A syscall is a mechanism for application programs to request a service from the operating system (OS) or one of the OS system services. GDB can catch some or all of the syscalls issued by the debuggee, and show the related information for each syscall. If no argument is specified, calls to and returns from all system calls will be caught. NAME can be any system call name that is valid for the underlying OS. Just what syscalls are valid depends on the OS. On GNU and Unix systems, you can find the full list of valid syscall names on `/usr/include/asm/unistd.h'. Normally, GDB knows in advance which syscalls are valid for each OS, so you can use the GDB command-line completion facilities (*note command completion: Completion.) to list the available choices. You may also specify the system call numerically. A syscall's number is the value passed to the OS's syscall dispatcher to identify the requested service. When you specify the syscall by its name, GDB uses its database of syscalls to convert the name into the corresponding numeric code, but using the number directly may be useful if GDB's database does not have the complete list of syscalls on your system (e.g., because GDB lags behind the OS upgrades). You may specify a group of related syscalls to be caught at once using the `group:' syntax (`g:' is a shorter equivalent). For instance, on some platforms GDB allows you to catch all network related syscalls, by passing the argument `group:network' to `catch syscall'. Note that not all syscall groups are available in every system. You can use the command completion facilities (*note command completion: Completion.) to list the syscall groups available on your environment. The example below illustrates how this command works if you don't provide arguments to it: (gdb) catch syscall Catchpoint 1 (syscall) (gdb) r Starting program: /tmp/catch-syscall Catchpoint 1 (call to syscall 'close'), \ 0xffffe424 in __kernel_vsyscall () (gdb) c Continuing. Catchpoint 1 (returned from syscall 'close'), \ 0xffffe424 in __kernel_vsyscall () (gdb) Here is an example of catching a system call by name: (gdb) catch syscall chroot Catchpoint 1 (syscall 'chroot' [61]) (gdb) r Starting program: /tmp/catch-syscall Catchpoint 1 (call to syscall 'chroot'), \ 0xffffe424 in __kernel_vsyscall () (gdb) c Continuing. Catchpoint 1 (returned from syscall 'chroot'), \ 0xffffe424 in __kernel_vsyscall () (gdb) An example of specifying a system call numerically. In the case below, the syscall number has a corresponding entry in the XML file, so GDB finds its name and prints it: (gdb) catch syscall 252 Catchpoint 1 (syscall(s) 'exit_group') (gdb) r Starting program: /tmp/catch-syscall Catchpoint 1 (call to syscall 'exit_group'), \ 0xffffe424 in __kernel_vsyscall () (gdb) c Continuing. Program exited normally. (gdb) Here is an example of catching a syscall group: (gdb) catch syscall group:process Catchpoint 1 (syscalls 'exit' [1] 'fork' [2] 'waitpid' [7] 'execve' [11] 'wait4' [114] 'clone' [120] 'vfork' [190] 'exit_group' [252] 'waitid' [284] 'unshare' [310]) (gdb) r Starting program: /tmp/catch-syscall Catchpoint 1 (call to syscall fork), 0x00007ffff7df4e27 in open64 () from /lib64/ld-linux-x86-64.so.2 (gdb) c Continuing. However, there can be situations when there is no corresponding name in XML file for that syscall number. In this case, GDB prints a warning message saying that it was not able to find the syscall name, but the catchpoint will be set anyway. See the example below: (gdb) catch syscall 764 warning: The number '764' does not represent a known syscall. Catchpoint 2 (syscall 764) (gdb) If you configure GDB using the `--without-expat' option, it will not be able to display syscall names. Also, if your architecture does not have an XML file describing its system calls, you will not be able to see the syscall names. It is important to notice that these two features are used for accessing the syscall name database. In either case, you will see a warning like this: (gdb) catch syscall warning: Could not open "syscalls/i386-linux.xml" warning: Could not load the syscall XML file 'syscalls/i386-linux.xml'. GDB will not be able to display syscall names. Catchpoint 1 (syscall) (gdb) Of course, the file name will change depending on your architecture and system. Still using the example above, you can also try to catch a syscall by its number. In this case, you would see something like: (gdb) catch syscall 252 Catchpoint 1 (syscall(s) 252) Again, in this case GDB would not be able to display syscall's names. `fork' A call to `fork'. `vfork' A call to `vfork'. `load [REGEXP]' `unload [REGEXP]' The loading or unloading of a shared library. If REGEXP is given, then the catchpoint will stop only if the regular expression matches one of the affected libraries. `signal [SIGNAL... | `all']' The delivery of a signal. With no arguments, this catchpoint will catch any signal that is not used internally by GDB, specifically, all signals except `SIGTRAP' and `SIGINT'. With the argument `all', all signals, including those used by GDB, will be caught. This argument cannot be used with other signal names. Otherwise, the arguments are a list of signal names as given to `handle' (*note Signals::). Only signals specified in this list will be caught. One reason that `catch signal' can be more useful than `handle' is that you can attach commands and conditions to the catchpoint. When a signal is caught by a catchpoint, the signal's `stop' and `print' settings, as specified by `handle', are ignored. However, whether the signal is still delivered to the inferior depends on the `pass' setting; this can be changed in the catchpoint's commands. `tcatch EVENT' Set a catchpoint that is enabled only for one stop. The catchpoint is automatically deleted after the first time the event is caught. Use the `info break' command to list the current catchpoints.  File: gdb.info, Node: Delete Breaks, Next: Disabling, Prev: Set Catchpoints, Up: Breakpoints 5.1.4 Deleting Breakpoints -------------------------- It is often necessary to eliminate a breakpoint, watchpoint, or catchpoint once it has done its job and you no longer want your program to stop there. This is called "deleting" the breakpoint. A breakpoint that has been deleted no longer exists; it is forgotten. With the `clear' command you can delete breakpoints according to where they are in your program. With the `delete' command you can delete individual breakpoints, watchpoints, or catchpoints by specifying their breakpoint numbers. It is not necessary to delete a breakpoint to proceed past it. GDB automatically ignores breakpoints on the first instruction to be executed when you continue execution without changing the execution address. `clear' Delete any breakpoints at the next instruction to be executed in the selected stack frame (*note Selecting a Frame: Selection.). When the innermost frame is selected, this is a good way to delete a breakpoint where your program just stopped. `clear LOCSPEC' Delete any breakpoint with a code location that corresponds to LOCSPEC. *Note Location Specifications::, for the various forms of LOCSPEC. Which code locations correspond to LOCSPEC depends on the form used in the location specification LOCSPEC: `LINENUM' `FILENAME:LINENUM' `-line LINENUM' `-source FILENAME -line LINENUM' If LOCSPEC specifies a line number, with or without a file name, the command deletes any breakpoint with a code location that is at or within the specified line LINENUM in files that match the specified FILENAME. If FILENAME is omitted, it defaults to the current source file. `*ADDRESS' If LOCSPEC specifies an address, the command deletes any breakpoint with a code location that is at the given ADDRESS. `FUNCTION' `-function FUNCTION' If LOCSPEC specifies a function, the command deletes any breakpoint with a code location that is at the entry to any function whose name matches FUNCTION. Ambiguity in names of files and functions can be resolved as described in *Note Location Specifications::. `delete [breakpoints] [LIST...]' Delete the breakpoints, watchpoints, tracepoints, or catchpoints of the breakpoint list specified as argument. If no argument is specified, delete all breakpoints, watchpoints, tracepoints, and catchpoints (GDB asks confirmation, unless you have `set confirm off'). You can abbreviate this command as `d'.  File: gdb.info, Node: Disabling, Next: Conditions, Prev: Delete Breaks, Up: Breakpoints 5.1.5 Disabling Breakpoints --------------------------- Rather than deleting a breakpoint, watchpoint, or catchpoint, you might prefer to "disable" it. This makes the breakpoint inoperative as if it had been deleted, but remembers the information on the breakpoint so that you can "enable" it again later. You disable and enable breakpoints, watchpoints, tracepoints, and catchpoints with the `enable' and `disable' commands, optionally specifying one or more breakpoint numbers as arguments. Use `info break' to print a list of all breakpoints, watchpoints, tracepoints, and catchpoints if you do not know which numbers to use. Disabling and enabling a breakpoint that has multiple locations affects all of its locations. A breakpoint, watchpoint, or catchpoint can have any of several different states of enablement: * Enabled. The breakpoint stops your program. A breakpoint set with the `break' command starts out in this state. * Disabled. The breakpoint has no effect on your program. * Enabled once. The breakpoint stops your program, but then becomes disabled. * Enabled for a count. The breakpoint stops your program for the next N times, then becomes disabled. * Enabled for deletion. The breakpoint stops your program, but immediately after it does so it is deleted permanently. A breakpoint set with the `tbreak' command starts out in this state. You can use the following commands to enable or disable breakpoints, watchpoints, tracepoints, and catchpoints: `disable [breakpoints] [LIST...]' Disable the specified breakpoints--or all breakpoints, if none are listed. A disabled breakpoint has no effect but is not forgotten. All options such as ignore-counts, conditions and commands are remembered in case the breakpoint is enabled again later. You may abbreviate `disable' as `dis'. `enable [breakpoints] [LIST...]' Enable the specified breakpoints (or all defined breakpoints). They become effective once again in stopping your program. `enable [breakpoints] once LIST...' Enable the specified breakpoints temporarily. GDB disables any of these breakpoints immediately after stopping your program. `enable [breakpoints] count COUNT LIST...' Enable the specified breakpoints temporarily. GDB records COUNT with each of the specified breakpoints, and decrements a breakpoint's count when it is hit. When any count reaches 0, GDB disables that breakpoint. If a breakpoint has an ignore count (*note Break Conditions: Conditions.), that will be decremented to 0 before COUNT is affected. `enable [breakpoints] delete LIST...' Enable the specified breakpoints to work once, then die. GDB deletes any of these breakpoints as soon as your program stops there. Breakpoints set by the `tbreak' command start out in this state. Except for a breakpoint set with `tbreak' (*note Setting Breakpoints: Set Breaks.), breakpoints that you set are initially enabled; subsequently, they become disabled or enabled only when you use one of the commands above. (The command `until' can set and delete a breakpoint of its own, but it does not change the state of your other breakpoints; see *Note Continuing and Stepping: Continuing and Stepping.)  File: gdb.info, Node: Conditions, Next: Break Commands, Prev: Disabling, Up: Breakpoints 5.1.6 Break Conditions ---------------------- The simplest sort of breakpoint breaks every time your program reaches a specified place. You can also specify a "condition" for a breakpoint. A condition is just a Boolean expression in your programming language (*note Expressions: Expressions.). A breakpoint with a condition evaluates the expression each time your program reaches it, and your program stops only if the condition is _true_. This is the converse of using assertions for program validation; in that situation, you want to stop when the assertion is violated--that is, when the condition is false. In C, if you want to test an assertion expressed by the condition ASSERT, you should set the condition `! ASSERT' on the appropriate breakpoint. Conditions are also accepted for watchpoints; you may not need them, since a watchpoint is inspecting the value of an expression anyhow--but it might be simpler, say, to just set a watchpoint on a variable name, and specify a condition that tests whether the new value is an interesting one. Break conditions can have side effects, and may even call functions in your program. This can be useful, for example, to activate functions that log program progress, or to use your own print functions to format special data structures. The effects are completely predictable unless there is another enabled breakpoint at the same address. (In that case, GDB might see the other breakpoint first and stop your program without checking the condition of this one.) Note that breakpoint commands are usually more convenient and flexible than break conditions for the purpose of performing side effects when a breakpoint is reached (*note Breakpoint Command Lists: Break Commands.). Breakpoint conditions can also be evaluated on the target's side if the target supports it. Instead of evaluating the conditions locally, GDB encodes the expression into an agent expression (*note Agent Expressions::) suitable for execution on the target, independently of GDB. Global variables become raw memory locations, locals become stack accesses, and so forth. In this case, GDB will only be notified of a breakpoint trigger when its condition evaluates to true. This mechanism may provide faster response times depending on the performance characteristics of the target since it does not need to keep GDB informed about every breakpoint trigger, even those with false conditions. Break conditions can be specified when a breakpoint is set, by using `if' in the arguments to the `break' command. *Note Setting Breakpoints: Set Breaks. They can also be changed at any time with the `condition' command. You can also use the `if' keyword with the `watch' command. The `catch' command does not recognize the `if' keyword; `condition' is the only way to impose a further condition on a catchpoint. `condition BNUM EXPRESSION' Specify EXPRESSION as the break condition for breakpoint, watchpoint, or catchpoint number BNUM. After you set a condition, breakpoint BNUM stops your program only if the value of EXPRESSION is true (nonzero, in C). When you use `condition', GDB checks EXPRESSION immediately for syntactic correctness, and to determine whether symbols in it have referents in the context of your breakpoint. If EXPRESSION uses symbols not referenced in the context of the breakpoint, GDB prints an error message: No symbol "foo" in current context. GDB does not actually evaluate EXPRESSION at the time the `condition' command (or a command that sets a breakpoint with a condition, like `break if ...') is given, however. *Note Expressions: Expressions. `condition -force BNUM EXPRESSION' When the `-force' flag is used, define the condition even if EXPRESSION is invalid at all the current locations of breakpoint BNUM. This is similar to the `-force-condition' option of the `break' command. `condition BNUM' Remove the condition from breakpoint number BNUM. It becomes an ordinary unconditional breakpoint. A special case of a breakpoint condition is to stop only when the breakpoint has been reached a certain number of times. This is so useful that there is a special way to do it, using the "ignore count" of the breakpoint. Every breakpoint has an ignore count, which is an integer. Most of the time, the ignore count is zero, and therefore has no effect. But if your program reaches a breakpoint whose ignore count is positive, then instead of stopping, it just decrements the ignore count by one and continues. As a result, if the ignore count value is N, the breakpoint does not stop the next N times your program reaches it. `ignore BNUM COUNT' Set the ignore count of breakpoint number BNUM to COUNT. The next COUNT times the breakpoint is reached, your program's execution does not stop; other than to decrement the ignore count, GDB takes no action. To make the breakpoint stop the next time it is reached, specify a count of zero. When you use `continue' to resume execution of your program from a breakpoint, you can specify an ignore count directly as an argument to `continue', rather than using `ignore'. *Note Continuing and Stepping: Continuing and Stepping. If a breakpoint has a positive ignore count and a condition, the condition is not checked. Once the ignore count reaches zero, GDB resumes checking the condition. You could achieve the effect of the ignore count with a condition such as `$foo-- <= 0' using a debugger convenience variable that is decremented each time. *Note Convenience Variables: Convenience Vars. Ignore counts apply to breakpoints, watchpoints, tracepoints, and catchpoints.  File: gdb.info, Node: Break Commands, Next: Dynamic Printf, Prev: Conditions, Up: Breakpoints 5.1.7 Breakpoint Command Lists ------------------------------ You can give any breakpoint (or watchpoint or catchpoint) a series of commands to execute when your program stops due to that breakpoint. For example, you might want to print the values of certain expressions, or enable other breakpoints. `commands [LIST...]' `... COMMAND-LIST ...' `end' Specify a list of commands for the given breakpoints. The commands themselves appear on the following lines. Type a line containing just `end' to terminate the commands. To remove all commands from a breakpoint, type `commands' and follow it immediately with `end'; that is, give no commands. With no argument, `commands' refers to the last breakpoint, watchpoint, or catchpoint set (not to the breakpoint most recently encountered). If the most recent breakpoints were set with a single command, then the `commands' will apply to all the breakpoints set by that command. This applies to breakpoints set by `rbreak', and also applies when a single `break' command creates multiple breakpoints (*note Ambiguous Expressions: Ambiguous Expressions.). Pressing as a means of repeating the last GDB command is disabled within a COMMAND-LIST. Inside a command list, you can use the command `disable $_hit_bpnum' to disable the encountered breakpoint. If your breakpoint has several code locations, the command `disable $_hit_bpnum.$_hit_locno' will disable the specific breakpoint code location encountered. If the breakpoint has only one location, this command will disable the encountered breakpoint. You can use breakpoint commands to start your program up again. Simply use the `continue' command, or `step', or any other command that resumes execution. Any other commands in the command list, after a command that resumes execution, are ignored. This is because any time you resume execution (even with a simple `next' or `step'), you may encounter another breakpoint--which could have its own command list, leading to ambiguities about which list to execute. If the first command you specify in a command list is `silent', the usual message about stopping at a breakpoint is not printed. This may be desirable for breakpoints that are to print a specific message and then continue. If none of the remaining commands print anything, you see no sign that the breakpoint was reached. `silent' is meaningful only at the beginning of a breakpoint command list. The commands `echo', `output', and `printf' allow you to print precisely controlled output, and are often useful in silent breakpoints. *Note Commands for Controlled Output: Output. For example, here is how you could use breakpoint commands to print the value of `x' at entry to `foo' whenever `x' is positive. break foo if x>0 commands silent printf "x is %d\n",x cont end One application for breakpoint commands is to compensate for one bug so you can test for another. Put a breakpoint just after the erroneous line of code, give it a condition to detect the case in which something erroneous has been done, and give it commands to assign correct values to any variables that need them. End with the `continue' command so that your program does not stop, and start with the `silent' command so that no output is produced. Here is an example: break 403 commands silent set x = y + 4 cont end  File: gdb.info, Node: Dynamic Printf, Next: Save Breakpoints, Prev: Break Commands, Up: Breakpoints 5.1.8 Dynamic Printf -------------------- The dynamic printf command `dprintf' combines a breakpoint with formatted printing of your program's data to give you the effect of inserting `printf' calls into your program on-the-fly, without having to recompile it. In its most basic form, the output goes to the GDB console. However, you can set the variable `dprintf-style' for alternate handling. For instance, you can ask to format the output by calling your program's `printf' function. This has the advantage that the characters go to the program's output device, so they can recorded in redirects to files and so forth. If you are doing remote debugging with a stub or agent, you can also ask to have the printf handled by the remote agent. In addition to ensuring that the output goes to the remote program's device along with any other output the program might produce, you can also ask that the dprintf remain active even after disconnecting from the remote target. Using the stub/agent is also more efficient, as it can do everything without needing to communicate with GDB. `dprintf LOCSPEC,TEMPLATE,EXPRESSION[,EXPRESSION...]' Whenever execution reaches a code location that results from resolving LOCSPEC, print the values of one or more EXPRESSIONS under the control of the string TEMPLATE. To print several values, separate them with commas. `set dprintf-style STYLE' Set the dprintf output to be handled in one of several different styles enumerated below. A change of style affects all existing dynamic printfs immediately. (If you need individual control over the print commands, simply define normal breakpoints with explicitly-supplied command lists.) `gdb' Handle the output using the GDB `printf' command. When using this style, it is possible to use the `%V' format specifier (*note %V Format Specifier::). `call' Handle the output by calling a function in your program (normally `printf'). When using this style the supported format specifiers depend entirely on the function being called. Most of GDB's format specifiers align with those supported by the `printf' function, however, GDB's `%V' format specifier extension is not supported by `printf'. When using `call' style dprintf, care should be taken to ensure that only format specifiers supported by the output function are used, otherwise the results will be undefined. `agent' Have the remote debugging agent (such as `gdbserver') handle the output itself. This style is only available for agents that support running commands on the target. This style does not support the `%V' format specifier. `set dprintf-function FUNCTION' Set the function to call if the dprintf style is `call'. By default its value is `printf'. You may set it to any expression that GDB can evaluate to a function, as per the `call' command. `set dprintf-channel CHANNEL' Set a "channel" for dprintf. If set to a non-empty value, GDB will evaluate it as an expression and pass the result as a first argument to the `dprintf-function', in the manner of `fprintf' and similar functions. Otherwise, the dprintf format string will be the first argument, in the manner of `printf'. As an example, if you wanted `dprintf' output to go to a logfile that is a standard I/O stream assigned to the variable `mylog', you could do the following: (gdb) set dprintf-style call (gdb) set dprintf-function fprintf (gdb) set dprintf-channel mylog (gdb) dprintf 25,"at line 25, glob=%d\n",glob Dprintf 1 at 0x123456: file main.c, line 25. (gdb) info break 1 dprintf keep y 0x00123456 in main at main.c:25 call (void) fprintf (mylog,"at line 25, glob=%d\n",glob) continue (gdb) Note that the `info break' displays the dynamic printf commands as normal breakpoint commands; you can thus easily see the effect of the variable settings. `set disconnected-dprintf on' `set disconnected-dprintf off' Choose whether `dprintf' commands should continue to run if GDB has disconnected from the target. This only applies if the `dprintf-style' is `agent'. `show disconnected-dprintf off' Show the current choice for disconnected `dprintf'. GDB does not check the validity of function and channel, relying on you to supply values that are meaningful for the contexts in which they are being used. For instance, the function and channel may be the values of local variables, but if that is the case, then all enabled dynamic prints must be at locations within the scope of those locals. If evaluation fails, GDB will report an error.  File: gdb.info, Node: Save Breakpoints, Next: Static Probe Points, Prev: Dynamic Printf, Up: Breakpoints 5.1.9 How to save breakpoints to a file --------------------------------------- To save breakpoint definitions to a file use the `save breakpoints' command. `save breakpoints [FILENAME]' This command saves all current breakpoint definitions together with their commands and ignore counts, into a file `FILENAME' suitable for use in a later debugging session. This includes all types of breakpoints (breakpoints, watchpoints, catchpoints, tracepoints). To read the saved breakpoint definitions, use the `source' command (*note Command Files::). Note that watchpoints with expressions involving local variables may fail to be recreated because it may not be possible to access the context where the watchpoint is valid anymore. Because the saved breakpoint definitions are simply a sequence of GDB commands that recreate the breakpoints, you can edit the file in your favorite editing program, and remove the breakpoint definitions you're not interested in, or that can no longer be recreated.  File: gdb.info, Node: Static Probe Points, Next: Error in Breakpoints, Prev: Save Breakpoints, Up: Breakpoints 5.1.10 Static Probe Points -------------------------- GDB supports "SDT" probes in the code. SDT stands for Statically Defined Tracing, and the probes are designed to have a tiny runtime code and data footprint, and no dynamic relocations. Currently, the following types of probes are supported on ELF-compatible systems: * `SystemTap' (`http://sourceware.org/systemtap/') SDT probes(1). `SystemTap' probes are usable from assembly, C and C++ languages(2). * `DTrace' (`http://oss.oracle.com/projects/DTrace') USDT probes. `DTrace' probes are usable from C and C++ languages. Some `SystemTap' probes have an associated semaphore variable; for instance, this happens automatically if you defined your probe using a DTrace-style `.d' file. If your probe has a semaphore, GDB will automatically enable it when you specify a breakpoint using the `-probe-stap' notation. But, if you put a breakpoint at a probe's location by some other method (e.g., `break file:line'), then GDB will not automatically set the semaphore. `DTrace' probes do not support semaphores. You can examine the available static static probes using `info probes', with optional arguments: `info probes [TYPE] [PROVIDER [NAME [OBJFILE]]]' If given, TYPE is either `stap' for listing `SystemTap' probes or `dtrace' for listing `DTrace' probes. If omitted all probes are listed regardless of their types. If given, PROVIDER is a regular expression used to match against provider names when selecting which probes to list. If omitted, probes by all probes from all providers are listed. If given, NAME is a regular expression to match against probe names when selecting which probes to list. If omitted, probe names are not considered when deciding whether to display them. If given, OBJFILE is a regular expression used to select which object files (executable or shared libraries) to examine. If not given, all object files are considered. `info probes all' List the available static probes, from all types. Some probe points can be enabled and/or disabled. The effect of enabling or disabling a probe depends on the type of probe being handled. Some `DTrace' probes can be enabled or disabled, but `SystemTap' probes cannot be disabled. You can enable (or disable) one or more probes using the following commands, with optional arguments: `enable probes [PROVIDER [NAME [OBJFILE]]]' If given, PROVIDER is a regular expression used to match against provider names when selecting which probes to enable. If omitted, all probes from all providers are enabled. If given, NAME is a regular expression to match against probe names when selecting which probes to enable. If omitted, probe names are not considered when deciding whether to enable them. If given, OBJFILE is a regular expression used to select which object files (executable or shared libraries) to examine. If not given, all object files are considered. `disable probes [PROVIDER [NAME [OBJFILE]]]' See the `enable probes' command above for a description of the optional arguments accepted by this command. A probe may specify up to twelve arguments. These are available at the point at which the probe is defined--that is, when the current PC is at the probe's location. The arguments are available using the convenience variables (*note Convenience Vars::) `$_probe_arg0'...`$_probe_arg11'. In `SystemTap' probes each probe argument is an integer of the appropriate size; types are not preserved. In `DTrace' probes types are preserved provided that they are recognized as such by GDB; otherwise the value of the probe argument will be a long integer. The convenience variable `$_probe_argc' holds the number of arguments at the current probe point. These variables are always available, but attempts to access them at any location other than a probe point will cause GDB to give an error message. ---------- Footnotes ---------- (1) See `http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps' for more information on how to add `SystemTap' SDT probes in your applications. (2) See `http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation' for a good reference on how the SDT probes are implemented.  File: gdb.info, Node: Error in Breakpoints, Next: Breakpoint-related Warnings, Prev: Static Probe Points, Up: Breakpoints 5.1.11 "Cannot insert breakpoints" ---------------------------------- If you request too many active hardware-assisted breakpoints and watchpoints, you will see this error message: Stopped; cannot insert breakpoints. You may have requested too many hardware breakpoints and watchpoints. This message is printed when you attempt to resume the program, since only then GDB knows exactly how many hardware breakpoints and watchpoints it needs to insert. When this message is printed, you need to disable or remove some of the hardware-assisted breakpoints and watchpoints, and then continue.  File: gdb.info, Node: Breakpoint-related Warnings, Prev: Error in Breakpoints, Up: Breakpoints 5.1.12 "Breakpoint address adjusted..." --------------------------------------- Some processor architectures place constraints on the addresses at which breakpoints may be placed. For architectures thus constrained, GDB will attempt to adjust the breakpoint's address to comply with the constraints dictated by the architecture. One example of such an architecture is the Fujitsu FR-V. The FR-V is a VLIW architecture in which a number of RISC-like instructions may be bundled together for parallel execution. The FR-V architecture constrains the location of a breakpoint instruction within such a bundle to the instruction with the lowest address. GDB honors this constraint by adjusting a breakpoint's address to the first in the bundle. It is not uncommon for optimized code to have bundles which contain instructions from different source statements, thus it may happen that a breakpoint's address will be adjusted from one source statement to another. Since this adjustment may significantly alter GDB's breakpoint related behavior from what the user expects, a warning is printed when the breakpoint is first set and also when the breakpoint is hit. A warning like the one below is printed when setting a breakpoint that's been subject to address adjustment: warning: Breakpoint address adjusted from 0x00010414 to 0x00010410. Such warnings are printed both for user settable and GDB's internal breakpoints. If you see one of these warnings, you should verify that a breakpoint set at the adjusted address will have the desired affect. If not, the breakpoint in question may be removed and other breakpoints may be set which will have the desired behavior. E.g., it may be sufficient to place the breakpoint at a later instruction. A conditional breakpoint may also be useful in some cases to prevent the breakpoint from triggering too often. GDB will also issue a warning when stopping at one of these adjusted breakpoints: warning: Breakpoint 1 address previously adjusted from 0x00010414 to 0x00010410. When this warning is encountered, it may be too late to take remedial action except in cases where the breakpoint is hit earlier or more frequently than expected.  File: gdb.info, Node: Continuing and Stepping, Next: Skipping Over Functions and Files, Prev: Breakpoints, Up: Stopping 5.2 Continuing and Stepping =========================== "Continuing" means resuming program execution until your program completes normally. In contrast, "stepping" means executing just one more "step" of your program, where "step" may mean either one line of source code, or one machine instruction (depending on what particular command you use). Either when continuing or when stepping, your program may stop even sooner, due to a breakpoint or a signal. (If it stops due to a signal, you may want to use `handle', or use `signal 0' to resume execution (*note Signals: Signals.), or you may step into the signal's handler (*note stepping and signal handlers::).) `continue [IGNORE-COUNT]' `c [IGNORE-COUNT]' `fg [IGNORE-COUNT]' Resume program execution, at the address where your program last stopped; any breakpoints set at that address are bypassed. The optional argument IGNORE-COUNT allows you to specify a further number of times to ignore a breakpoint at this location; its effect is like that of `ignore' (*note Break Conditions: Conditions.). The argument IGNORE-COUNT is meaningful only when your program stopped due to a breakpoint. At other times, the argument to `continue' is ignored. The synonyms `c' and `fg' (for "foreground", as the debugged program is deemed to be the foreground program) are provided purely for convenience, and have exactly the same behavior as `continue'. To resume execution at a different place, you can use `return' (*note Returning from a Function: Returning.) to go back to the calling function; or `jump' (*note Continuing at a Different Address: Jumping.) to go to an arbitrary location in your program. A typical technique for using stepping is to set a breakpoint (*note Breakpoints; Watchpoints; and Catchpoints: Breakpoints.) at the beginning of the function or the section of your program where a problem is believed to lie, run your program until it stops at that breakpoint, and then step through the suspect area, examining the variables that are interesting, until you see the problem happen. `step' Continue running your program until control reaches a different source line, then stop it and return control to GDB. This command is abbreviated `s'. _Warning:_ If you use the `step' command while control is within a function that was compiled without debugging information, execution proceeds until control reaches a function that does have debugging information. Likewise, it will not step into a function which is compiled without debugging information. To step through functions without debugging information, use the `stepi' command, described below. The `step' command only stops at the first instruction of a source line. This prevents the multiple stops that could otherwise occur in `switch' statements, `for' loops, etc. `step' continues to stop if a function that has debugging information is called within the line. In other words, `step' _steps inside_ any functions called within the line. Also, the `step' command only enters a function if there is line number information for the function. Otherwise it acts like the `next' command. This avoids problems when using `cc -gl' on MIPS machines. Previously, `step' entered subroutines if there was any debugging information about the routine. `step COUNT' Continue running as in `step', but do so COUNT times. If a breakpoint is reached, or a signal not related to stepping occurs before COUNT steps, stepping stops right away. `next [COUNT]' Continue to the next source line in the current (innermost) stack frame. This is similar to `step', but function calls that appear within the line of code are executed without stopping. Execution stops when control reaches a different line of code at the original stack level that was executing when you gave the `next' command. This command is abbreviated `n'. An argument COUNT is a repeat count, as for `step'. The `next' command only stops at the first instruction of a source line. This prevents multiple stops that could otherwise occur in `switch' statements, `for' loops, etc. `set step-mode' `set step-mode on' The `set step-mode on' command causes the `step' command to stop at the first instruction of a function which contains no debug line information rather than stepping over it. This is useful in cases where you may be interested in inspecting the machine instructions of a function which has no symbolic info and do not want GDB to automatically skip over this function. `set step-mode off' Causes the `step' command to step over any functions which contains no debug information. This is the default. `show step-mode' Show whether GDB will stop in or step over functions without source line debug information. `finish' Continue running until just after function in the selected stack frame returns. Print the returned value (if any). This command can be abbreviated as `fin'. Contrast this with the `return' command (*note Returning from a Function: Returning.). `set print finish [on|off]' `show print finish' By default the `finish' command will show the value that is returned by the function. This can be disabled using `set print finish off'. When disabled, the value is still entered into the value history (*note Value History::), but not displayed. `until' `u' Continue running until a source line past the current line, in the current stack frame, is reached. This command is used to avoid single stepping through a loop more than once. It is like the `next' command, except that when `until' encounters a jump, it automatically continues execution until the program counter is greater than the address of the jump. This means that when you reach the end of a loop after single stepping though it, `until' makes your program continue execution until it exits the loop. In contrast, a `next' command at the end of a loop simply steps back to the beginning of the loop, which forces you to step through the next iteration. `until' always stops your program if it attempts to exit the current stack frame. `until' may produce somewhat counterintuitive results if the order of machine code does not match the order of the source lines. For example, in the following excerpt from a debugging session, the `f' (`frame') command shows that execution is stopped at line `206'; yet when we use `until', we get to line `195': (gdb) f #0 main (argc=4, argv=0xf7fffae8) at m4.c:206 206 expand_input(); (gdb) until 195 for ( ; argc > 0; NEXTARG) { This happened because, for execution efficiency, the compiler had generated code for the loop closure test at the end, rather than the start, of the loop--even though the test in a C `for'-loop is written before the body of the loop. The `until' command appeared to step back to the beginning of the loop when it advanced to this expression; however, it has not really gone to an earlier statement--not in terms of the actual machine code. `until' with no argument works by means of single instruction stepping, and hence is slower than `until' with an argument. `until LOCSPEC' `u LOCSPEC' Continue running your program until either it reaches a code location that results from resolving LOCSPEC, or the current stack frame returns. LOCSPEC is any of the forms described in *Note Location Specifications::. This form of the command uses temporary breakpoints, and hence is quicker than `until' without an argument. The specified location is actually reached only if it is in the current frame. This implies that `until' can be used to skip over recursive function invocations. For instance in the code below, if the current location is line `96', issuing `until 99' will execute the program up to line `99' in the same invocation of factorial, i.e., after the inner invocations have returned. 94 int factorial (int value) 95 { 96 if (value > 1) { 97 value *= factorial (value - 1); 98 } 99 return (value); 100 } `advance LOCSPEC' Continue running your program until either it reaches a code location that results from resolving LOCSPEC, or the current stack frame returns. LOCSPEC is any of the forms described in *Note Location Specifications::. This command is similar to `until', but `advance' will not skip over recursive function calls, and the target code location doesn't have to be in the same frame as the current one. `stepi' `stepi ARG' `si' Execute one machine instruction, then stop and return to the debugger. It is often useful to do `display/i $pc' when stepping by machine instructions. This makes GDB automatically display the next instruction to be executed, each time your program stops. *Note Automatic Display: Auto Display. An argument is a repeat count, as in `step'. `nexti' `nexti ARG' `ni' Execute one machine instruction, but if it is a function call, proceed until the function returns. An argument is a repeat count, as in `next'. By default, and if available, GDB makes use of target-assisted "range stepping". In other words, whenever you use a stepping command (e.g., `step', `next'), GDB tells the target to step the corresponding range of instruction addresses instead of issuing multiple single-steps. This speeds up line stepping, particularly for remote targets. Ideally, there should be no reason you would want to turn range stepping off. However, it's possible that a bug in the debug info, a bug in the remote stub (for remote targets), or even a bug in GDB could make line stepping behave incorrectly when target-assisted range stepping is enabled. You can use the following command to turn off range stepping if necessary: `set range-stepping' `show range-stepping' Control whether range stepping is enabled. If `on', and the target supports it, GDB tells the target to step a range of addresses itself, instead of issuing multiple single-steps. If `off', GDB always issues single-steps, even if range stepping is supported by the target. The default is `on'.  File: gdb.info, Node: Skipping Over Functions and Files, Next: Signals, Prev: Continuing and Stepping, Up: Stopping 5.3 Skipping Over Functions and Files ===================================== The program you are debugging may contain some functions which are uninteresting to debug. The `skip' command lets you tell GDB to skip a function, all functions in a file or a particular function in a particular file when stepping. For example, consider the following C function: 101 int func() 102 { 103 foo(boring()); 104 bar(boring()); 105 } Suppose you wish to step into the functions `foo' and `bar', but you are not interested in stepping through `boring'. If you run `step' at line 103, you'll enter `boring()', but if you run `next', you'll step over both `foo' and `boring'! One solution is to `step' into `boring' and use the `finish' command to immediately exit it. But this can become tedious if `boring' is called from many places. A more flexible solution is to execute `skip boring'. This instructs GDB never to step into `boring'. Now when you execute `step' at line 103, you'll step over `boring' and directly into `foo'. Functions may be skipped by providing either a function name, linespec (*note Location Specifications::), regular expression that matches the function's name, file name or a `glob'-style pattern that matches the file name. On Posix systems the form of the regular expression is "Extended Regular Expressions". See for example `man 7 regex' on GNU/Linux systems. On non-Posix systems the form of the regular expression is whatever is provided by the `regcomp' function of the underlying system. See for example `man 7 glob' on GNU/Linux systems for a description of `glob'-style patterns. `skip [OPTIONS]' The basic form of the `skip' command takes zero or more options that specify what to skip. The OPTIONS argument is any useful combination of the following: `-file FILE' `-fi FILE' Functions in FILE will be skipped over when stepping. `-gfile FILE-GLOB-PATTERN' `-gfi FILE-GLOB-PATTERN' Functions in files matching FILE-GLOB-PATTERN will be skipped over when stepping. (gdb) skip -gfi utils/*.c `-function LINESPEC' `-fu LINESPEC' Functions named by LINESPEC or the function containing the line named by LINESPEC will be skipped over when stepping. *Note Location Specifications::. `-rfunction REGEXP' `-rfu REGEXP' Functions whose name matches REGEXP will be skipped over when stepping. This form is useful for complex function names. For example, there is generally no need to step into C++ `std::string' constructors or destructors. Plus with C++ templates it can be hard to write out the full name of the function, and often it doesn't matter what the template arguments are. Specifying the function to be skipped as a regular expression makes this easier. (gdb) skip -rfu ^std::(allocator|basic_string)<.*>::~?\1 *\( If you want to skip every templated C++ constructor and destructor in the `std' namespace you can do: (gdb) skip -rfu ^std::([a-zA-z0-9_]+)<.*>::~?\1 *\( If no options are specified, the function you're currently debugging will be skipped. `skip function [LINESPEC]' After running this command, the function named by LINESPEC or the function containing the line named by LINESPEC will be skipped over when stepping. *Note Location Specifications::. If you do not specify LINESPEC, the function you're currently debugging will be skipped. (If you have a function called `file' that you want to skip, use `skip function file'.) `skip file [FILENAME]' After running this command, any function whose source lives in FILENAME will be skipped over when stepping. (gdb) skip file boring.c File boring.c will be skipped when stepping. If you do not specify FILENAME, functions whose source lives in the file you're currently debugging will be skipped. Skips can be listed, deleted, disabled, and enabled, much like breakpoints. These are the commands for managing your list of skips: `info skip [RANGE]' Print details about the specified skip(s). If RANGE is not specified, print a table with details about all functions and files marked for skipping. `info skip' prints the following information about each skip: _Identifier_ A number identifying this skip. _Enabled or Disabled_ Enabled skips are marked with `y'. Disabled skips are marked with `n'. _Glob_ If the file name is a `glob' pattern this is `y'. Otherwise it is `n'. _File_ The name or `glob' pattern of the file to be skipped. If no file is specified this is `'. _RE_ If the function name is a `regular expression' this is `y'. Otherwise it is `n'. _Function_ The name or regular expression of the function to skip. If no function is specified this is `'. `skip delete [RANGE]' Delete the specified skip(s). If RANGE is not specified, delete all skips. `skip enable [RANGE]' Enable the specified skip(s). If RANGE is not specified, enable all skips. `skip disable [RANGE]' Disable the specified skip(s). If RANGE is not specified, disable all skips. `set debug skip [on|off]' Set whether to print the debug output about skipping files and functions. `show debug skip' Show whether the debug output about skipping files and functions is printed.  File: gdb.info, Node: Signals, Next: Thread Stops, Prev: Skipping Over Functions and Files, Up: Stopping 5.4 Signals =========== A signal is an asynchronous event that can happen in a program. The operating system defines the possible kinds of signals, and gives each kind a name and a number. For example, in Unix `SIGINT' is the signal a program gets when you type an interrupt character (often `Ctrl-c'); `SIGSEGV' is the signal a program gets from referencing a place in memory far away from all the areas in use; `SIGALRM' occurs when the alarm clock timer goes off (which happens only if your program has requested an alarm). Some signals, including `SIGALRM', are a normal part of the functioning of your program. Others, such as `SIGSEGV', indicate errors; these signals are "fatal" (they kill your program immediately) if the program has not specified in advance some other way to handle the signal. `SIGINT' does not indicate an error in your program, but it is normally fatal so it can carry out the purpose of the interrupt: to kill the program. GDB has the ability to detect any occurrence of a signal in your program. You can tell GDB in advance what to do for each kind of signal. Normally, GDB is set up to let the non-erroneous signals like `SIGALRM' be silently passed to your program (so as not to interfere with their role in the program's functioning) but to stop your program immediately whenever an error signal happens. You can change these settings with the `handle' command. `info signals' `info handle' Print a table of all the kinds of signals and how GDB has been told to handle each one. You can use this to see the signal numbers of all the defined types of signals. `info signals SIG' Similar, but print information only about the specified signal number. `info handle' is an alias for `info signals'. `catch signal [SIGNAL... | `all']' Set a catchpoint for the indicated signals. *Note Set Catchpoints::, for details about this command. `handle SIGNAL [ SIGNAL ... ] [KEYWORDS...]' Change the way GDB handles each SIGNAL. Each SIGNAL can be the number of a signal or its name (with or without the `SIG' at the beginning); a list of signal numbers of the form `LOW-HIGH'; or the word `all', meaning all the known signals, except `SIGINT' and `SIGTRAP', which are used by GDB. Optional argument KEYWORDS, described below, say what changes to make to all of the specified signals. The keywords allowed by the `handle' command can be abbreviated. Their full names are: `nostop' GDB should not stop your program when this signal happens. It may still print a message telling you that the signal has come in. `stop' GDB should stop your program when this signal happens. This implies the `print' keyword as well. `print' GDB should print a message when this signal happens. `noprint' GDB should not mention the occurrence of the signal at all. This implies the `nostop' keyword as well. `pass' `noignore' GDB should allow your program to see this signal; your program can handle the signal, or else it may terminate if the signal is fatal and not handled. `pass' and `noignore' are synonyms. `nopass' `ignore' GDB should not allow your program to see this signal. `nopass' and `ignore' are synonyms. When a signal stops your program, the signal is not visible to the program until you continue. Your program sees the signal then, if `pass' is in effect for the signal in question _at that time_. In other words, after GDB reports a signal, you can use the `handle' command with `pass' or `nopass' to control whether your program sees that signal when you continue. The default is set to `nostop', `noprint', `pass' for non-erroneous signals such as `SIGALRM', `SIGWINCH' and `SIGCHLD', and to `stop', `print', `pass' for the erroneous signals. You can also use the `signal' command to prevent your program from seeing a signal, or cause it to see a signal it normally would not see, or to give it any signal at any time. For example, if your program stopped due to some sort of memory reference error, you might store correct values into the erroneous variables and continue, hoping to see more execution; but your program would probably terminate immediately as a result of the fatal signal once it saw the signal. To prevent this, you can continue with `signal 0'. *Note Giving your Program a Signal: Signaling. GDB optimizes for stepping the mainline code. If a signal that has `handle nostop' and `handle pass' set arrives while a stepping command (e.g., `stepi', `step', `next') is in progress, GDB lets the signal handler run and then resumes stepping the mainline code once the signal handler returns. In other words, GDB steps over the signal handler. This prevents signals that you've specified as not interesting (with `handle nostop') from changing the focus of debugging unexpectedly. Note that the signal handler itself may still hit a breakpoint, stop for another signal that has `handle stop' in effect, or for any other event that normally results in stopping the stepping command sooner. Also note that GDB still informs you that the program received a signal if `handle print' is set. If you set `handle pass' for a signal, and your program sets up a handler for it, then issuing a stepping command, such as `step' or `stepi', when your program is stopped due to the signal will step _into_ the signal handler (if the target supports that). Likewise, if you use the `queue-signal' command to queue a signal to be delivered to the current thread when execution of the thread resumes (*note Giving your Program a Signal: Signaling.), then a stepping command will step into the signal handler. Here's an example, using `stepi' to step to the first instruction of `SIGUSR1''s handler: (gdb) handle SIGUSR1 Signal Stop Print Pass to program Description SIGUSR1 Yes Yes Yes User defined signal 1 (gdb) c Continuing. Program received signal SIGUSR1, User defined signal 1. main () sigusr1.c:28 28 p = 0; (gdb) si sigusr1_handler () at sigusr1.c:9 9 { The same, but using `queue-signal' instead of waiting for the program to receive the signal first: (gdb) n 28 p = 0; (gdb) queue-signal SIGUSR1 (gdb) si sigusr1_handler () at sigusr1.c:9 9 { (gdb) On some targets, GDB can inspect extra signal information associated with the intercepted signal, before it is actually delivered to the program being debugged. This information is exported by the convenience variable `$_siginfo', and consists of data that is passed by the kernel to the signal handler at the time of the receipt of a signal. The data type of the information itself is target dependent. You can see the data type using the `ptype $_siginfo' command. On Unix systems, it typically corresponds to the standard `siginfo_t' type, as defined in the `signal.h' system header. Here's an example, on a GNU/Linux system, printing the stray referenced address that raised a segmentation fault. (gdb) continue Program received signal SIGSEGV, Segmentation fault. 0x0000000000400766 in main () 69 *(int *)p = 0; (gdb) ptype $_siginfo type = struct { int si_signo; int si_errno; int si_code; union { int _pad[28]; struct {...} _kill; struct {...} _timer; struct {...} _rt; struct {...} _sigchld; struct {...} _sigfault; struct {...} _sigpoll; } _sifields; } (gdb) ptype $_siginfo._sifields._sigfault type = struct { void *si_addr; } (gdb) p $_siginfo._sifields._sigfault.si_addr $1 = (void *) 0x7ffff7ff7000 Depending on target support, `$_siginfo' may also be writable. On some targets, a `SIGSEGV' can be caused by a boundary violation, i.e., accessing an address outside of the allowed range. In those cases GDB may displays additional information, depending on how GDB has been told to handle the signal. With `handle stop SIGSEGV', GDB displays the violation kind: "Upper" or "Lower", the memory address accessed and the bounds, while with `handle nostop SIGSEGV' no additional information is displayed. The usual output of a segfault is: Program received signal SIGSEGV, Segmentation fault 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68 68 value = *(p + len); While a bound violation is presented as: Program received signal SIGSEGV, Segmentation fault Upper bound violation while accessing address 0x7fffffffc3b3 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3] 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68 68 value = *(p + len);  File: gdb.info, Node: Thread Stops, Prev: Signals, Up: Stopping 5.5 Stopping and Starting Multi-thread Programs =============================================== GDB supports debugging programs with multiple threads (*note Debugging Programs with Multiple Threads: Threads.). There are two modes of controlling execution of your program within the debugger. In the default mode, referred to as "all-stop mode", when any thread in your program stops (for example, at a breakpoint or while being stepped), all other threads in the program are also stopped by GDB. On some targets, GDB also supports "non-stop mode", in which other threads can continue to run freely while you examine the stopped thread in the debugger. * Menu: * All-Stop Mode:: All threads stop when GDB takes control * Non-Stop Mode:: Other threads continue to execute * Background Execution:: Running your program asynchronously * Thread-Specific Breakpoints:: Controlling breakpoints * Interrupted System Calls:: GDB may interfere with system calls * Observer Mode:: GDB does not alter program behavior  File: gdb.info, Node: All-Stop Mode, Next: Non-Stop Mode, Up: Thread Stops 5.5.1 All-Stop Mode ------------------- In all-stop mode, whenever your program stops under GDB for any reason, _all_ threads of execution stop, not just the current thread. This allows you to examine the overall state of the program, including switching between threads, without worrying that things may change underfoot. Conversely, whenever you restart the program, _all_ threads start executing. _This is true even when single-stepping_ with commands like `step' or `next'. In particular, GDB cannot single-step all threads in lockstep. Since thread scheduling is up to your debugging target's operating system (not controlled by GDB), other threads may execute more than one statement while the current thread completes a single step. Moreover, in general other threads stop in the middle of a statement, rather than at a clean statement boundary, when the program stops. You might even find your program stopped in another thread after continuing or even single-stepping. This happens whenever some other thread runs into a breakpoint, a signal, or an exception before the first thread completes whatever you requested. Whenever GDB stops your program, due to a breakpoint or a signal, it automatically selects the thread where that breakpoint or signal happened. GDB alerts you to the context switch with a message such as `[Switching to Thread N]' to identify the thread. On some OSes, you can modify GDB's default behavior by locking the OS scheduler to allow only a single thread to run. `set scheduler-locking MODE' Set the scheduler locking mode. It applies to normal execution, record mode, and replay mode. MODE can be one of the following: `off' There is no locking and any thread may run at any time. `on' Only the current thread may run when the inferior is resumed. New threads created by the resumed thread are held stopped at their entry point, before they execute any instruction. `step' Behaves like `on' when stepping, and `off' otherwise. Threads other than the current never get a chance to run when you step, and they are completely free to run when you use commands like `continue', `until', or `finish'. This mode optimizes for single-stepping; it prevents other threads from preempting the current thread while you are stepping, so that the focus of debugging does not change unexpectedly. However, unless another thread hits a breakpoint during its timeslice, GDB does not change the current thread away from the thread that you are debugging. `replay' Behaves like `on' in replay mode, and `off' in either record mode or during normal execution. This is the default mode. `show scheduler-locking' Display the current scheduler locking mode. By default, when you issue one of the execution commands such as `continue', `next' or `step', GDB allows only threads of the current inferior to run. For example, if GDB is attached to two inferiors, each with two threads, the `continue' command resumes only the two threads of the current inferior. This is useful, for example, when you debug a program that forks and you want to hold the parent stopped (so that, for instance, it doesn't run to exit), while you debug the child. In other situations, you may not be interested in inspecting the current state of any of the processes GDB is attached to, and you may want to resume them all until some breakpoint is hit. In the latter case, you can instruct GDB to allow all threads of all the inferiors to run with the `set schedule-multiple' command. `set schedule-multiple' Set the mode for allowing threads of multiple processes to be resumed when an execution command is issued. When `on', all threads of all processes are allowed to run. When `off', only the threads of the current process are resumed. The default is `off'. The `scheduler-locking' mode takes precedence when set to `on', or while you are stepping and set to `step'. `show schedule-multiple' Display the current mode for resuming the execution of threads of multiple processes.  File: gdb.info, Node: Non-Stop Mode, Next: Background Execution, Prev: All-Stop Mode, Up: Thread Stops 5.5.2 Non-Stop Mode ------------------- For some multi-threaded targets, GDB supports an optional mode of operation in which you can examine stopped program threads in the debugger while other threads continue to execute freely. This minimizes intrusion when debugging live systems, such as programs where some threads have real-time constraints or must continue to respond to external events. This is referred to as "non-stop" mode. In non-stop mode, when a thread stops to report a debugging event, _only_ that thread is stopped; GDB does not stop other threads as well, in contrast to the all-stop mode behavior. Additionally, execution commands such as `continue' and `step' apply by default only to the current thread in non-stop mode, rather than all threads as in all-stop mode. This allows you to control threads explicitly in ways that are not possible in all-stop mode -- for example, stepping one thread while allowing others to run freely, stepping one thread while holding all others stopped, or stepping several threads independently and simultaneously. To enter non-stop mode, use this sequence of commands before you run or attach to your program: # If using the CLI, pagination breaks non-stop. set pagination off # Finally, turn it on! set non-stop on You can use these commands to manipulate the non-stop mode setting: `set non-stop on' Enable selection of non-stop mode. `set non-stop off' Disable selection of non-stop mode. `show non-stop' Show the current non-stop enablement setting. Note these commands only reflect whether non-stop mode is enabled, not whether the currently-executing program is being run in non-stop mode. In particular, the `set non-stop' preference is only consulted when GDB starts or connects to the target program, and it is generally not possible to switch modes once debugging has started. Furthermore, since not all targets support non-stop mode, even when you have enabled non-stop mode, GDB may still fall back to all-stop operation by default. In non-stop mode, all execution commands apply only to the current thread by default. That is, `continue' only continues one thread. To continue all threads, issue `continue -a' or `c -a'. You can use GDB's background execution commands (*note Background Execution::) to run some threads in the background while you continue to examine or step others from GDB. The MI execution commands (*note GDB/MI Program Execution::) are always executed asynchronously in non-stop mode. Suspending execution is done with the `interrupt' command when running in the background, or `Ctrl-c' during foreground execution. In all-stop mode, this stops the whole process; but in non-stop mode the interrupt applies only to the current thread. To stop the whole program, use `interrupt -a'. Other execution commands do not currently support the `-a' option. In non-stop mode, when a thread stops, GDB doesn't automatically make that thread current, as it does in all-stop mode. This is because the thread stop notifications are asynchronous with respect to GDB's command interpreter, and it would be confusing if GDB unexpectedly changed to a different thread just as you entered a command to operate on the previously current thread.  File: gdb.info, Node: Background Execution, Next: Thread-Specific Breakpoints, Prev: Non-Stop Mode, Up: Thread Stops 5.5.3 Background Execution -------------------------- GDB's execution commands have two variants: the normal foreground (synchronous) behavior, and a background (asynchronous) behavior. In foreground execution, GDB waits for the program to report that some thread has stopped before prompting for another command. In background execution, GDB immediately gives a command prompt so that you can issue other commands while your program runs. If the target doesn't support async mode, GDB issues an error message if you attempt to use the background execution commands. To specify background execution, add a `&' to the command. For example, the background form of the `continue' command is `continue&', or just `c&'. The execution commands that accept background execution are: `run' *Note Starting your Program: Starting. `attach' *Note Debugging an Already-running Process: Attach. `step' *Note step: Continuing and Stepping. `stepi' *Note stepi: Continuing and Stepping. `next' *Note next: Continuing and Stepping. `nexti' *Note nexti: Continuing and Stepping. `continue' *Note continue: Continuing and Stepping. `finish' *Note finish: Continuing and Stepping. `until' *Note until: Continuing and Stepping. Background execution is especially useful in conjunction with non-stop mode for debugging programs with multiple threads; see *Note Non-Stop Mode::. However, you can also use these commands in the normal all-stop mode with the restriction that you cannot issue another execution command until the previous one finishes. Examples of commands that are valid in all-stop mode while the program is running include `help' and `info break'. You can interrupt your program while it is running in the background by using the `interrupt' command. `interrupt' `interrupt -a' Suspend execution of the running program. In all-stop mode, `interrupt' stops the whole process, but in non-stop mode, it stops only the current thread. To stop the whole program in non-stop mode, use `interrupt -a'.  File: gdb.info, Node: Thread-Specific Breakpoints, Next: Interrupted System Calls, Prev: Background Execution, Up: Thread Stops 5.5.4 Thread-Specific Breakpoints --------------------------------- When your program has multiple threads (*note Debugging Programs with Multiple Threads: Threads.), you can choose whether to set breakpoints on all threads, or on a particular thread. `break LOCSPEC thread THREAD-ID' `break LOCSPEC thread THREAD-ID if ...' LOCSPEC specifies a code location or locations in your program. *Note Location Specifications::, for details. Use the qualifier `thread THREAD-ID' with a breakpoint command to specify that you only want GDB to stop the program when a particular thread reaches this breakpoint. The THREAD-ID specifier is one of the thread identifiers assigned by GDB, shown in the first column of the `info threads' display. If you do not specify `thread THREAD-ID' when you set a breakpoint, the breakpoint applies to _all_ threads of your program. You can use the `thread' qualifier on conditional breakpoints as well; in this case, place `thread THREAD-ID' before or after the breakpoint condition, like this: (gdb) break frik.c:13 thread 28 if bartab > lim Thread-specific breakpoints are automatically deleted when GDB detects the corresponding thread is no longer in the thread list. For example: (gdb) c Thread-specific breakpoint 3 deleted - thread 28 no longer in the thread list. There are several ways for a thread to disappear, such as a regular thread exit, but also when you detach from the process with the `detach' command (*note Debugging an Already-running Process: Attach.), or if GDB loses the remote connection (*note Remote Debugging::), etc. Note that with some targets, GDB is only able to detect a thread has exited when the user explicitly asks for the thread list with the `info threads' command. A breakpoint can't be both thread-specific and inferior-specific (*note Inferior-Specific Breakpoints::), or task-specific (*note Ada Tasks::); using more than one of the `thread', `inferior', or `task' keywords when creating a breakpoint will give an error.  File: gdb.info, Node: Interrupted System Calls, Next: Observer Mode, Prev: Thread-Specific Breakpoints, Up: Thread Stops 5.5.5 Interrupted System Calls ------------------------------ There is an unfortunate side effect when using GDB to debug multi-threaded programs. If one thread stops for a breakpoint, or for some other reason, and another thread is blocked in a system call, then the system call may return prematurely. This is a consequence of the interaction between multiple threads and the signals that GDB uses to implement breakpoints and other events that stop execution. To handle this problem, your program should check the return value of each system call and react appropriately. This is good programming style anyways. For example, do not write code like this: sleep (10); The call to `sleep' will return early if a different thread stops at a breakpoint or for some other reason. Instead, write this: int unslept = 10; while (unslept > 0) unslept = sleep (unslept); A system call is allowed to return early, so the system is still conforming to its specification. But GDB does cause your multi-threaded program to behave differently than it would without GDB. Also, GDB uses internal breakpoints in the thread library to monitor certain events such as thread creation and thread destruction. When such an event happens, a system call in another thread may return prematurely, even though your program does not appear to stop.  File: gdb.info, Node: Observer Mode, Prev: Interrupted System Calls, Up: Thread Stops 5.5.6 Observer Mode ------------------- If you want to build on non-stop mode and observe program behavior without any chance of disruption by GDB, you can set variables to disable all of the debugger's attempts to modify state, whether by writing memory, inserting breakpoints, etc. These operate at a low level, intercepting operations from all commands. When all of these are set to `off', then GDB is said to be "observer mode". As a convenience, the variable `observer' can be set to disable these, plus enable non-stop mode. Note that GDB will not prevent you from making nonsensical combinations of these settings. For instance, if you have enabled `may-insert-breakpoints' but disabled `may-write-memory', then breakpoints that work by writing trap instructions into the code stream will still not be able to be placed. `set observer on' `set observer off' When set to `on', this disables all the permission variables below (except for `insert-fast-tracepoints'), plus enables non-stop debugging. Setting this to `off' switches back to normal debugging, though remaining in non-stop mode. `show observer' Show whether observer mode is on or off. `set may-write-registers on' `set may-write-registers off' This controls whether GDB will attempt to alter the values of registers, such as with assignment expressions in `print', or the `jump' command. It defaults to `on'. `show may-write-registers' Show the current permission to write registers. `set may-write-memory on' `set may-write-memory off' This controls whether GDB will attempt to alter the contents of memory, such as with assignment expressions in `print'. It defaults to `on'. `show may-write-memory' Show the current permission to write memory. `set may-insert-breakpoints on' `set may-insert-breakpoints off' This controls whether GDB will attempt to insert breakpoints. This affects all breakpoints, including internal breakpoints defined by GDB. It defaults to `on'. `show may-insert-breakpoints' Show the current permission to insert breakpoints. `set may-insert-tracepoints on' `set may-insert-tracepoints off' This controls whether GDB will attempt to insert (regular) tracepoints at the beginning of a tracing experiment. It affects only non-fast tracepoints, fast tracepoints being under the control of `may-insert-fast-tracepoints'. It defaults to `on'. `show may-insert-tracepoints' Show the current permission to insert tracepoints. `set may-insert-fast-tracepoints on' `set may-insert-fast-tracepoints off' This controls whether GDB will attempt to insert fast tracepoints at the beginning of a tracing experiment. It affects only fast tracepoints, regular (non-fast) tracepoints being under the control of `may-insert-tracepoints'. It defaults to `on'. `show may-insert-fast-tracepoints' Show the current permission to insert fast tracepoints. `set may-interrupt on' `set may-interrupt off' This controls whether GDB will attempt to interrupt or stop program execution. When this variable is `off', the `interrupt' command will have no effect, nor will `Ctrl-c'. It defaults to `on'. `show may-interrupt' Show the current permission to interrupt or stop the program.  File: gdb.info, Node: Reverse Execution, Next: Process Record and Replay, Prev: Stopping, Up: Top 6 Running programs backward *************************** When you are debugging a program, it is not unusual to realize that you have gone too far, and some event of interest has already happened. If the target environment supports it, GDB can allow you to "rewind" the program by running it backward. A target environment that supports reverse execution should be able to "undo" the changes in machine state that have taken place as the program was executing normally. Variables, registers etc. should revert to their previous values. Obviously this requires a great deal of sophistication on the part of the target environment; not all target environments can support reverse execution. When a program is executed in reverse, the instructions that have most recently been executed are "un-executed", in reverse order. The program counter runs backward, following the previous thread of execution in reverse. As each instruction is "un-executed", the values of memory and/or registers that were changed by that instruction are reverted to their previous states. After executing a piece of source code in reverse, all side effects of that code should be "undone", and all variables should be returned to their prior values(1). On some platforms, GDB has built-in support for reverse execution, activated with the `record' or `record btrace' commands. *Note Process Record and Replay::. Some remote targets, typically full system emulators, support reverse execution directly without requiring any special command. If you are debugging in a target environment that supports reverse execution, GDB provides the following commands. `reverse-continue [IGNORE-COUNT]' `rc [IGNORE-COUNT]' Beginning at the point where your program last stopped, start executing in reverse. Reverse execution will stop for breakpoints and synchronous exceptions (signals), just like normal execution. Behavior of asynchronous signals depends on the target environment. `reverse-step [COUNT]' Run the program backward until control reaches the start of a different source line; then stop it, and return control to GDB. Like the `step' command, `reverse-step' will only stop at the beginning of a source line. It "un-executes" the previously executed source line. If the previous source line included calls to debuggable functions, `reverse-step' will step (backward) into the called function, stopping at the beginning of the _last_ statement in the called function (typically a return statement). Also, as with the `step' command, if non-debuggable functions are called, `reverse-step' will run thru them backward without stopping. `reverse-stepi [COUNT]' Reverse-execute one machine instruction. Note that the instruction to be reverse-executed is _not_ the one pointed to by the program counter, but the instruction executed prior to that one. For instance, if the last instruction was a jump, `reverse-stepi' will take you back from the destination of the jump to the jump instruction itself. `reverse-next [COUNT]' Run backward to the beginning of the previous line executed in the current (innermost) stack frame. If the line contains function calls, they will be "un-executed" without stopping. Starting from the first line of a function, `reverse-next' will take you back to the caller of that function, _before_ the function was called, just as the normal `next' command would take you from the last line of a function back to its return to its caller (2). `reverse-nexti [COUNT]' Like `nexti', `reverse-nexti' executes a single instruction in reverse, except that called functions are "un-executed" atomically. That is, if the previously executed instruction was a return from another function, `reverse-nexti' will continue to execute in reverse until the call to that function (from the current stack frame) is reached. `reverse-finish' Just as the `finish' command takes you to the point where the current function returns, `reverse-finish' takes you to the point where it was called. Instead of ending up at the end of the current function invocation, you end up at the beginning. `set exec-direction' Set the direction of target execution. `set exec-direction reverse' GDB will perform all execution commands in reverse, until the exec-direction mode is changed to "forward". Affected commands include `step, stepi, next, nexti, continue, and finish'. The `return' command cannot be used in reverse mode. `set exec-direction forward' GDB will perform all execution commands in the normal fashion. This is the default. ---------- Footnotes ---------- (1) Note that some side effects are easier to undo than others. For instance, memory and registers are relatively easy, but device I/O is hard. Some targets may be able undo things like device I/O, and some may not. The contract between GDB and the reverse executing target requires only that the target do something reasonable when GDB tells it to execute backwards, and then report the results back to GDB. Whatever the target reports back to GDB, GDB will report back to the user. GDB assumes that the memory and registers that the target reports are in a consistent state, but GDB accepts whatever it is given. (2) Unless the code is too heavily optimized.  File: gdb.info, Node: Process Record and Replay, Next: Stack, Prev: Reverse Execution, Up: Top 7 Recording Inferior's Execution and Replaying It ************************************************* On some platforms, GDB provides a special "process record and replay" target that can record a log of the process execution, and replay it later with both forward and reverse execution commands. When this target is in use, if the execution log includes the record for the next instruction, GDB will debug in "replay mode". In the replay mode, the inferior does not really execute code instructions. Instead, all the events that normally happen during code execution are taken from the execution log. While code is not really executed in replay mode, the values of registers (including the program counter register) and the memory of the inferior are still changed as they normally would. Their contents are taken from the execution log. If the record for the next instruction is not in the execution log, GDB will debug in "record mode". In this mode, the inferior executes normally, and GDB records the execution log for future replay. The process record and replay target supports reverse execution (*note Reverse Execution::), even if the platform on which the inferior runs does not. However, the reverse execution is limited in this case by the range of the instructions recorded in the execution log. In other words, reverse execution on platforms that don't support it directly can only be done in the replay mode. When debugging in the reverse direction, GDB will work in replay mode as long as the execution log includes the record for the previous instruction; otherwise, it will work in record mode, if the platform supports reverse execution, or stop if not. Currently, process record and replay is supported on ARM, Aarch64, Moxie, PowerPC, PowerPC64, S/390, and x86 (i386/amd64) running GNU/Linux. Process record and replay can be used both when native debugging, and when remote debugging via `gdbserver'. For architecture environments that support process record and replay, GDB provides the following commands: `record METHOD' This command starts the process record and replay target. The recording method can be specified as parameter. Without a parameter the command uses the `full' recording method. The following recording methods are available: `full' Full record/replay recording using GDB's software record and replay implementation. This method allows replaying and reverse execution. `btrace FORMAT' Hardware-supported instruction recording, supported on Intel processors. This method does not record data. Further, the data is collected in a ring buffer so old data will be overwritten when the buffer is full. It allows limited reverse execution. Variables and registers are not available during reverse execution. In remote debugging, recording continues on disconnect. Recorded data can be inspected after reconnecting. The recording may be stopped using `record stop'. The recording format can be specified as parameter. Without a parameter the command chooses the recording format. The following recording formats are available: `bts' Use the "Branch Trace Store" (BTS) recording format. In this format, the processor stores a from/to record for each executed branch in the btrace ring buffer. `pt' Use the "Intel Processor Trace" recording format. In this format, the processor stores the execution trace in a compressed form that is afterwards decoded by GDB. The trace can be recorded with very low overhead. The compressed trace format also allows small trace buffers to already contain a big number of instructions compared to BTS. Decoding the recorded execution trace, on the other hand, is more expensive than decoding BTS trace. This is mostly due to the increased number of instructions to process. You should increase the buffer-size with care. Not all recording formats may be available on all processors. The process record and replay target can only debug a process that is already running. Therefore, you need first to start the process with the `run' or `start' commands, and then start the recording with the `record METHOD' command. Displaced stepping (*note displaced stepping: Maintenance Commands.) will be automatically disabled when process record and replay target is started. That's because the process record and replay target doesn't support displaced stepping. If the inferior is in the non-stop mode (*note Non-Stop Mode::) or in the asynchronous execution mode (*note Background Execution::), not all recording methods are available. The `full' recording method does not support these two modes. `record stop' Stop the process record and replay target. When process record and replay target stops, the entire execution log will be deleted and the inferior will either be terminated, or will remain in its final state. When you stop the process record and replay target in record mode (at the end of the execution log), the inferior will be stopped at the next instruction that would have been recorded. In other words, if you record for a while and then stop recording, the inferior process will be left in the same state as if the recording never happened. On the other hand, if the process record and replay target is stopped while in replay mode (that is, not at the end of the execution log, but at some earlier point), the inferior process will become "live" at that earlier state, and it will then be possible to continue the usual "live" debugging of the process from that state. When the inferior process exits, or GDB detaches from it, process record and replay target will automatically stop itself. `record goto' Go to a specific location in the execution log. There are several ways to specify the location to go to: `record goto begin' `record goto start' Go to the beginning of the execution log. `record goto end' Go to the end of the execution log. `record goto N' Go to instruction number N in the execution log. `record save FILENAME' Save the execution log to a file `FILENAME'. Default filename is `gdb_record.PROCESS_ID', where PROCESS_ID is the process ID of the inferior. This command may not be available for all recording methods. `record restore FILENAME' Restore the execution log from a file `FILENAME'. File must have been created with `record save'. `set record full insn-number-max LIMIT' `set record full insn-number-max unlimited' Set the limit of instructions to be recorded for the `full' recording method. Default value is 200000. If LIMIT is a positive number, then GDB will start deleting instructions from the log once the number of the record instructions becomes greater than LIMIT. For every new recorded instruction, GDB will delete the earliest recorded instruction to keep the number of recorded instructions at the limit. (Since deleting recorded instructions loses information, GDB lets you control what happens when the limit is reached, by means of the `stop-at-limit' option, described below.) If LIMIT is `unlimited' or zero, GDB will never delete recorded instructions from the execution log. The number of recorded instructions is limited only by the available memory. `show record full insn-number-max' Show the limit of instructions to be recorded with the `full' recording method. `set record full stop-at-limit' Control the behavior of the `full' recording method when the number of recorded instructions reaches the limit. If ON (the default), GDB will stop when the limit is reached for the first time and ask you whether you want to stop the inferior or continue running it and recording the execution log. If you decide to continue recording, each new recorded instruction will cause the oldest one to be deleted. If this option is OFF, GDB will automatically delete the oldest record to make room for each new one, without asking. `show record full stop-at-limit' Show the current setting of `stop-at-limit'. `set record full memory-query' Control the behavior when GDB is unable to record memory changes caused by an instruction for the `full' recording method. If ON, GDB will query whether to stop the inferior in that case. If this option is OFF (the default), GDB will automatically ignore the effect of such instructions on memory. Later, when GDB replays this execution log, it will mark the log of this instruction as not accessible, and it will not affect the replay results. `show record full memory-query' Show the current setting of `memory-query'. The `btrace' record target does not trace data. As a convenience, when replaying, GDB reads read-only memory off the live program directly, assuming that the addresses of the read-only areas don't change. This for example makes it possible to disassemble code while replaying, but not to print variables. In some cases, being able to inspect variables might be useful. You can use the following command for that: `set record btrace replay-memory-access' Control the behavior of the `btrace' recording method when accessing memory during replay. If `read-only' (the default), GDB will only allow accesses to read-only memory. If `read-write', GDB will allow accesses to read-only and to read-write memory. Beware that the accessed memory corresponds to the live target and not necessarily to the current replay position. `set record btrace cpu IDENTIFIER' Set the processor to be used for enabling workarounds for processor errata when decoding the trace. Processor errata are defects in processor operation, caused by its design or manufacture. They can cause a trace not to match the specification. This, in turn, may cause trace decode to fail. GDB can detect erroneous trace packets and correct them, thus avoiding the decoding failures. These corrections are known as "errata workarounds", and are enabled based on the processor on which the trace was recorded. By default, GDB attempts to detect the processor automatically, and apply the necessary workarounds for it. However, you may need to specify the processor if GDB does not yet support it. This command allows you to do that, and also allows to disable the workarounds. The argument IDENTIFIER identifies the CPU and is of the form: `VENDOR:PROCESSOR IDENTIFIER'. In addition, there are two special identifiers, `none' and `auto' (default). The following vendor identifiers and corresponding processor identifiers are currently supported: `intel' FAMILY/MODEL[/STEPPING] On GNU/Linux systems, the processor FAMILY, MODEL, and STEPPING can be obtained from `/proc/cpuinfo'. If IDENTIFIER is `auto', enable errata workarounds for the processor on which the trace was recorded. If IDENTIFIER is `none', errata workarounds are disabled. For example, when using an old GDB on a new system, decode may fail because GDB does not support the new processor. It often suffices to specify an older processor that GDB supports. (gdb) info record Active record target: record-btrace Recording format: Intel Processor Trace. Buffer size: 16kB. Failed to configure the Intel Processor Trace decoder: unknown cpu. (gdb) set record btrace cpu intel:6/158 (gdb) info record Active record target: record-btrace Recording format: Intel Processor Trace. Buffer size: 16kB. Recorded 84872 instructions in 3189 functions (0 gaps) for thread 1 (...). `show record btrace replay-memory-access' Show the current setting of `replay-memory-access'. `show record btrace cpu' Show the processor to be used for enabling trace decode errata workarounds. `set record btrace bts buffer-size SIZE' `set record btrace bts buffer-size unlimited' Set the requested ring buffer size for branch tracing in BTS format. Default is 64KB. If SIZE is a positive number, then GDB will try to allocate a buffer of at least SIZE bytes for each new thread that uses the btrace recording method and the BTS format. The actually obtained buffer size may differ from the requested SIZE. Use the `info record' command to see the actual buffer size for each thread that uses the btrace recording method and the BTS format. If LIMIT is `unlimited' or zero, GDB will try to allocate a buffer of 4MB. Bigger buffers mean longer traces. On the other hand, GDB will also need longer to process the branch trace data before it can be used. `show record btrace bts buffer-size SIZE' Show the current setting of the requested ring buffer size for branch tracing in BTS format. `set record btrace pt buffer-size SIZE' `set record btrace pt buffer-size unlimited' Set the requested ring buffer size for branch tracing in Intel Processor Trace format. Default is 16KB. If SIZE is a positive number, then GDB will try to allocate a buffer of at least SIZE bytes for each new thread that uses the btrace recording method and the Intel Processor Trace format. The actually obtained buffer size may differ from the requested SIZE. Use the `info record' command to see the actual buffer size for each thread. If LIMIT is `unlimited' or zero, GDB will try to allocate a buffer of 4MB. Bigger buffers mean longer traces. On the other hand, GDB will also need longer to process the branch trace data before it can be used. `show record btrace pt buffer-size SIZE' Show the current setting of the requested ring buffer size for branch tracing in Intel Processor Trace format. `info record' Show various statistics about the recording depending on the recording method: `full' For the `full' recording method, it shows the state of process record and its in-memory execution log buffer, including: * Whether in record mode or replay mode. * Lowest recorded instruction number (counting from when the current execution log started recording instructions). * Highest recorded instruction number. * Current instruction about to be replayed (if in replay mode). * Number of instructions contained in the execution log. * Maximum number of instructions that may be contained in the execution log. `btrace' For the `btrace' recording method, it shows: * Recording format. * Number of instructions that have been recorded. * Number of blocks of sequential control-flow formed by the recorded instructions. * Whether in record mode or replay mode. For the `bts' recording format, it also shows: * Size of the perf ring buffer. For the `pt' recording format, it also shows: * Size of the perf ring buffer. `record delete' When record target runs in replay mode ("in the past"), delete the subsequent execution log and begin to record a new execution log starting from the current address. This means you will abandon the previously recorded "future" and begin recording a new "future". `record instruction-history' Disassembles instructions from the recorded execution log. By default, ten instructions are disassembled. This can be changed using the `set record instruction-history-size' command. Instructions are printed in execution order. It can also print mixed source+disassembly if you specify the the `/m' or `/s' modifier, and print the raw instructions in hex as well as in symbolic form by specifying the `/r' or `/b' modifier. The behaviour of the `/m', `/s', `/r', and `/b' modifiers are the same as for the `disassemble' command (*note `disassemble': disassemble.). The current position marker is printed for the instruction at the current program counter value. This instruction can appear multiple times in the trace and the current position marker will be printed every time. To omit the current position marker, specify the `/p' modifier. To better align the printed instructions when the trace contains instructions from more than one function, the function name may be omitted by specifying the `/f' modifier. Speculatively executed instructions are prefixed with `?'. This feature is not available for all recording formats. There are several ways to specify what part of the execution log to disassemble: `record instruction-history INSN' Disassembles ten instructions starting from instruction number INSN. `record instruction-history INSN, +/-N' Disassembles N instructions around instruction number INSN. If N is preceded with `+', disassembles N instructions after instruction number INSN. If N is preceded with `-', disassembles N instructions before instruction number INSN. `record instruction-history' Disassembles ten more instructions after the last disassembly. `record instruction-history -' Disassembles ten more instructions before the last disassembly. `record instruction-history BEGIN, END' Disassembles instructions beginning with instruction number BEGIN until instruction number END. The instruction number END is included. This command may not be available for all recording methods. `set record instruction-history-size SIZE' `set record instruction-history-size unlimited' Define how many instructions to disassemble in the `record instruction-history' command. The default value is 10. A SIZE of `unlimited' means unlimited instructions. `show record instruction-history-size' Show how many instructions to disassemble in the `record instruction-history' command. `record function-call-history' Prints the execution history at function granularity. For each sequence of instructions that belong to the same function, it prints the name of that function, the source lines for this instruction sequence (if the `/l' modifier is specified), and the instructions numbers that form the sequence (if the `/i' modifier is specified). The function names are indented to reflect the call stack depth if the `/c' modifier is specified. The `/l', `/i', and `/c' modifiers can be given together. (gdb) list 1, 10 1 void foo (void) 2 { 3 } 4 5 void bar (void) 6 { 7 ... 8 foo (); 9 ... 10 } (gdb) record function-call-history /ilc 1 bar inst 1,4 at foo.c:6,8 2 foo inst 5,10 at foo.c:2,3 3 bar inst 11,13 at foo.c:9,10 By default, ten functions are printed. This can be changed using the `set record function-call-history-size' command. Functions are printed in execution order. There are several ways to specify what to print: `record function-call-history FUNC' Prints ten functions starting from function number FUNC. `record function-call-history FUNC, +/-N' Prints N functions around function number FUNC. If N is preceded with `+', prints N functions after function number FUNC. If N is preceded with `-', prints N functions before function number FUNC. `record function-call-history' Prints ten more functions after the last ten-function print. `record function-call-history -' Prints ten more functions before the last ten-function print. `record function-call-history BEGIN, END' Prints functions beginning with function number BEGIN until function number END. The function number END is included. This command may not be available for all recording methods. `set record function-call-history-size SIZE' `set record function-call-history-size unlimited' Define how many functions to print in the `record function-call-history' command. The default value is 10. A size of `unlimited' means unlimited functions. `show record function-call-history-size' Show how many functions to print in the `record function-call-history' command.  File: gdb.info, Node: Stack, Next: Source, Prev: Process Record and Replay, Up: Top 8 Examining the Stack ********************* When your program has stopped, the first thing you need to know is where it stopped and how it got there. Each time your program performs a function call, information about the call is generated. That information includes the location of the call in your program, the arguments of the call, and the local variables of the function being called. The information is saved in a block of data called a "stack frame". The stack frames are allocated in a region of memory called the "call stack". When your program stops, the GDB commands for examining the stack allow you to see all of this information. One of the stack frames is "selected" by GDB and many GDB commands refer implicitly to the selected frame. In particular, whenever you ask GDB for the value of a variable in your program, the value is found in the selected frame. There are special GDB commands to select whichever frame you are interested in. *Note Selecting a Frame: Selection. When your program stops, GDB automatically selects the currently executing frame and describes it briefly, similar to the `frame' command (*note Information about a Frame: Frame Info.). * Menu: * Frames:: Stack frames * Backtrace:: Backtraces * Selection:: Selecting a frame * Frame Info:: Information on a frame * Frame Apply:: Applying a command to several frames * Frame Filter Management:: Managing frame filters  File: gdb.info, Node: Frames, Next: Backtrace, Up: Stack 8.1 Stack Frames ================ The call stack is divided up into contiguous pieces called "stack frames", or "frames" for short; each frame is the data associated with one call to one function. The frame contains the arguments given to the function, the function's local variables, and the address at which the function is executing. When your program is started, the stack has only one frame, that of the function `main'. This is called the "initial" frame or the "outermost" frame. Each time a function is called, a new frame is made. Each time a function returns, the frame for that function invocation is eliminated. If a function is recursive, there can be many frames for the same function. The frame for the function in which execution is actually occurring is called the "innermost" frame. This is the most recently created of all the stack frames that still exist. Inside your program, stack frames are identified by their addresses. A stack frame consists of many bytes, each of which has its own address; each kind of computer has a convention for choosing one byte whose address serves as the address of the frame. Usually this address is kept in a register called the "frame pointer register" (*note $fp: Registers.) while execution is going on in that frame. GDB labels each existing stack frame with a "level", a number that is zero for the innermost frame, one for the frame that called it, and so on upward. These level numbers give you a way of designating stack frames in GDB commands. The terms "frame number" and "frame level" can be used interchangeably to describe this number. Some compilers provide a way to compile functions so that they operate without stack frames. (For example, the GCC option `-fomit-frame-pointer' generates functions without a frame.) This is occasionally done with heavily used library functions to save the frame setup time. GDB has limited facilities for dealing with these function invocations. If the innermost function invocation has no stack frame, GDB nevertheless regards it as though it had a separate frame, which is numbered zero as usual, allowing correct tracing of the function call chain. However, GDB has no provision for frameless functions elsewhere in the stack.  File: gdb.info, Node: Backtrace, Next: Selection, Prev: Frames, Up: Stack 8.2 Backtraces ============== A backtrace is a summary of how your program got where it is. It shows one line per frame, for many frames, starting with the currently executing frame (frame zero), followed by its caller (frame one), and on up the stack. To print a backtrace of the entire stack, use the `backtrace' command, or its alias `bt'. This command will print one line per frame for frames in the stack. By default, all stack frames are printed. You can stop the backtrace at any time by typing the system interrupt character, normally `Ctrl-c'. `backtrace [OPTION]... [QUALIFIER]... [COUNT]' `bt [OPTION]... [QUALIFIER]... [COUNT]' Print the backtrace of the entire stack. The optional COUNT can be one of the following: `N' `N' Print only the innermost N frames, where N is a positive number. `-N' `-N' Print only the outermost N frames, where N is a positive number. Options: `-full' Print the values of the local variables also. This can be combined with the optional COUNT to limit the number of frames shown. `-no-filters' Do not run Python frame filters on this backtrace. *Note Frame Filter API::, for more information. Additionally use *Note disable frame-filter all:: to turn off all frame filters. This is only relevant when GDB has been configured with `Python' support. `-hide' A Python frame filter might decide to "elide" some frames. Normally such elided frames are still printed, but they are indented relative to the filtered frames that cause them to be elided. The `-hide' option causes elided frames to not be printed at all. The `backtrace' command also supports a number of options that allow overriding relevant global print settings as set by `set backtrace' and `set print' subcommands: `-past-main [`on'|`off']' Set whether backtraces should continue past `main'. Related setting: *Note set backtrace past-main::. `-past-entry [`on'|`off']' Set whether backtraces should continue past the entry point of a program. Related setting: *Note set backtrace past-entry::. `-entry-values `no'|`only'|`preferred'|`if-needed'|`both'|`compact'|`default'' Set printing of function arguments at function entry. Related setting: *Note set print entry-values::. `-frame-arguments `all'|`scalars'|`none'' Set printing of non-scalar frame arguments. Related setting: *Note set print frame-arguments::. `-raw-frame-arguments [`on'|`off']' Set whether to print frame arguments in raw form. Related setting: *Note set print raw-frame-arguments::. `-frame-info `auto'|`source-line'|`location'|`source-and-location'|`location-and-address'|`short-location'' Set printing of frame information. Related setting: *Note set print frame-info::. The optional QUALIFIER is maintained for backward compatibility. It can be one of the following: `full' Equivalent to the `-full' option. `no-filters' Equivalent to the `-no-filters' option. `hide' Equivalent to the `-hide' option. The names `where' and `info stack' (abbreviated `info s') are additional aliases for `backtrace'. In a multi-threaded program, GDB by default shows the backtrace only for the current thread. To display the backtrace for several or all of the threads, use the command `thread apply' (*note thread apply: Threads.). For example, if you type `thread apply all backtrace', GDB will display the backtrace for all the threads; this is handy when you debug a core dump of a multi-threaded program. Each line in the backtrace shows the frame number and the function name. The program counter value is also shown--unless you use `set print address off'. The backtrace also shows the source file name and line number, as well as the arguments to the function. The program counter value is omitted if it is at the beginning of the code for that line number. Here is an example of a backtrace. It was made with the command `bt 3', so it shows the innermost three frames. #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) at builtin.c:993 #1 0x6e38 in expand_macro (sym=0x2b600, data=...) at macro.c:242 #2 0x6840 in expand_token (obs=0x0, t=177664, td=0xf7fffb08) at macro.c:71 (More stack frames follow...) The display for frame zero does not begin with a program counter value, indicating that your program has stopped at the beginning of the code for line `993' of `builtin.c'. The value of parameter `data' in frame 1 has been replaced by `...'. By default, GDB prints the value of a parameter only if it is a scalar (integer, pointer, enumeration, etc). See command `set print frame-arguments' in *Note Print Settings:: for more details on how to configure the way function parameter values are printed. The command `set print frame-info' (*note Print Settings::) controls what frame information is printed. If your program was compiled with optimizations, some compilers will optimize away arguments passed to functions if those arguments are never used after the call. Such optimizations generate code that passes arguments through registers, but doesn't store those arguments in the stack frame. GDB has no way of displaying such arguments in stack frames other than the innermost one. Here's what such a backtrace might look like: #0 m4_traceon (obs=0x24eb0, argc=1, argv=0x2b8c8) at builtin.c:993 #1 0x6e38 in expand_macro (sym=) at macro.c:242 #2 0x6840 in expand_token (obs=0x0, t=, td=0xf7fffb08) at macro.c:71 (More stack frames follow...) The values of arguments that were not saved in their stack frames are shown as `'. If you need to display the values of such optimized-out arguments, either deduce that from other variables whose values depend on the one you are interested in, or recompile without optimizations. Most programs have a standard user entry point--a place where system libraries and startup code transition into user code. For C this is `main'(1). When GDB finds the entry function in a backtrace it will terminate the backtrace, to avoid tracing into highly system-specific (and generally uninteresting) code. If you need to examine the startup code, or limit the number of levels in a backtrace, you can change this behavior: `set backtrace past-main' `set backtrace past-main on' Backtraces will continue past the user entry point. `set backtrace past-main off' Backtraces will stop when they encounter the user entry point. This is the default. `show backtrace past-main' Display the current user entry point backtrace policy. `set backtrace past-entry' `set backtrace past-entry on' Backtraces will continue past the internal entry point of an application. This entry point is encoded by the linker when the application is built, and is likely before the user entry point `main' (or equivalent) is called. `set backtrace past-entry off' Backtraces will stop when they encounter the internal entry point of an application. This is the default. `show backtrace past-entry' Display the current internal entry point backtrace policy. `set backtrace limit N' `set backtrace limit 0' `set backtrace limit unlimited' Limit the backtrace to N levels. A value of `unlimited' or zero means unlimited levels. `show backtrace limit' Display the current limit on backtrace levels. You can control how file names are displayed. `set filename-display' `set filename-display relative' Display file names relative to the compilation directory. This is the default. `set filename-display basename' Display only basename of a filename. `set filename-display absolute' Display an absolute filename. `show filename-display' Show the current way to display filenames. ---------- Footnotes ---------- (1) Note that embedded programs (the so-called "free-standing" environment) are not required to have a `main' function as the entry point. They could even have multiple entry points.  File: gdb.info, Node: Selection, Next: Frame Info, Prev: Backtrace, Up: Stack 8.3 Selecting a Frame ===================== Most commands for examining the stack and other data in your program work on whichever stack frame is selected at the moment. Here are the commands for selecting a stack frame; all of them finish by printing a brief description of the stack frame just selected. `frame [ FRAME-SELECTION-SPEC ]' `f [ FRAME-SELECTION-SPEC ]' The `frame' command allows different stack frames to be selected. The FRAME-SELECTION-SPEC can be any of the following: `NUM' `level NUM' Select frame level NUM. Recall that frame zero is the innermost (currently executing) frame, frame one is the frame that called the innermost one, and so on. The highest level frame is usually the one for `main'. As this is the most common method of navigating the frame stack, the string `level' can be omitted. For example, the following two commands are equivalent: (gdb) frame 3 (gdb) frame level 3 `address STACK-ADDRESS' Select the frame with stack address STACK-ADDRESS. The STACK-ADDRESS for a frame can be seen in the output of `info frame', for example: (gdb) info frame Stack level 1, frame at 0x7fffffffda30: rip = 0x40066d in b (amd64-entry-value.cc:59); saved rip 0x4004c5 tail call frame, caller of frame at 0x7fffffffda30 source language c++. Arglist at unknown address. Locals at unknown address, Previous frame's sp is 0x7fffffffda30 The STACK-ADDRESS for this frame is `0x7fffffffda30' as indicated by the line: Stack level 1, frame at 0x7fffffffda30: `function FUNCTION-NAME' Select the stack frame for function FUNCTION-NAME. If there are multiple stack frames for function FUNCTION-NAME then the inner most stack frame is selected. `view STACK-ADDRESS [ PC-ADDR ]' View a frame that is not part of GDB's backtrace. The frame viewed has stack address STACK-ADDR, and optionally, a program counter address of PC-ADDR. This is useful mainly if the chaining of stack frames has been damaged by a bug, making it impossible for GDB to assign numbers properly to all frames. In addition, this can be useful when your program has multiple stacks and switches between them. When viewing a frame outside the current backtrace using `frame view' then you can always return to the original stack using one of the previous stack frame selection instructions, for example `frame level 0'. `up N' Move N frames up the stack; N defaults to 1. For positive numbers N, this advances toward the outermost frame, to higher frame numbers, to frames that have existed longer. `down N' Move N frames down the stack; N defaults to 1. For positive numbers N, this advances toward the innermost frame, to lower frame numbers, to frames that were created more recently. You may abbreviate `down' as `do'. All of these commands end by printing two lines of output describing the frame. The first line shows the frame number, the function name, the arguments, and the source file and line number of execution in that frame. The second line shows the text of that source line. For example: (gdb) up #1 0x22f0 in main (argc=1, argv=0xf7fffbf4, env=0xf7fffbfc) at env.c:10 10 read_input_file (argv[i]); After such a printout, the `list' command with no arguments prints ten lines centered on the point of execution in the frame. You can also edit the program at the point of execution with your favorite editing program by typing `edit'. *Note Printing Source Lines: List, for details. `select-frame [ FRAME-SELECTION-SPEC ]' The `select-frame' command is a variant of `frame' that does not display the new frame after selecting it. This command is intended primarily for use in GDB command scripts, where the output might be unnecessary and distracting. The FRAME-SELECTION-SPEC is as for the `frame' command described in *Note Selecting a Frame: Selection. `up-silently N' `down-silently N' These two commands are variants of `up' and `down', respectively; they differ in that they do their work silently, without causing display of the new frame. They are intended primarily for use in GDB command scripts, where the output might be unnecessary and distracting.  File: gdb.info, Node: Frame Info, Next: Frame Apply, Prev: Selection, Up: Stack 8.4 Information About a Frame ============================= There are several other commands to print information about the selected stack frame. `frame' `f' When used without any argument, this command does not change which frame is selected, but prints a brief description of the currently selected stack frame. It can be abbreviated `f'. With an argument, this command is used to select a stack frame. *Note Selecting a Frame: Selection. `info frame' `info f' This command prints a verbose description of the selected stack frame, including: * the address of the frame * the address of the next frame down (called by this frame) * the address of the next frame up (caller of this frame) * the language in which the source code corresponding to this frame is written * the address of the frame's arguments * the address of the frame's local variables * the program counter saved in it (the address of execution in the caller frame) * which registers were saved in the frame The verbose description is useful when something has gone wrong that has made the stack format fail to fit the usual conventions. `info frame [ FRAME-SELECTION-SPEC ]' `info f [ FRAME-SELECTION-SPEC ]' Print a verbose description of the frame selected by FRAME-SELECTION-SPEC. The FRAME-SELECTION-SPEC is the same as for the `frame' command (*note Selecting a Frame: Selection.). The selected frame remains unchanged by this command. `info args [-q]' Print the arguments of the selected frame, each on a separate line. The optional flag `-q', which stands for `quiet', disables printing header information and messages explaining why no argument have been printed. `info args [-q] [-t TYPE_REGEXP] [REGEXP]' Like `info args', but only print the arguments selected with the provided regexp(s). If REGEXP is provided, print only the arguments whose names match the regular expression REGEXP. If TYPE_REGEXP is provided, print only the arguments whose types, as printed by the `whatis' command, match the regular expression TYPE_REGEXP. If TYPE_REGEXP contains space(s), it should be enclosed in quote characters. If needed, use backslash to escape the meaning of special characters or quotes. If both REGEXP and TYPE_REGEXP are provided, an argument is printed only if its name matches REGEXP and its type matches TYPE_REGEXP. `info locals [-q]' Print the local variables of the selected frame, each on a separate line. These are all variables (declared either static or automatic) accessible at the point of execution of the selected frame. The optional flag `-q', which stands for `quiet', disables printing header information and messages explaining why no local variables have been printed. `info locals [-q] [-t TYPE_REGEXP] [REGEXP]' Like `info locals', but only print the local variables selected with the provided regexp(s). If REGEXP is provided, print only the local variables whose names match the regular expression REGEXP. If TYPE_REGEXP is provided, print only the local variables whose types, as printed by the `whatis' command, match the regular expression TYPE_REGEXP. If TYPE_REGEXP contains space(s), it should be enclosed in quote characters. If needed, use backslash to escape the meaning of special characters or quotes. If both REGEXP and TYPE_REGEXP are provided, a local variable is printed only if its name matches REGEXP and its type matches TYPE_REGEXP. The command `info locals -q -t TYPE_REGEXP' can usefully be combined with the commands `frame apply' and `thread apply'. For example, your program might use Resource Acquisition Is Initialization types (RAII) such as `lock_something_t': each local variable of type `lock_something_t' automatically places a lock that is destroyed when the variable goes out of scope. You can then list all acquired locks in your program by doing thread apply all -s frame apply all -s info locals -q -t lock_something_t or the equivalent shorter form tfaas i lo -q -t lock_something_t  File: gdb.info, Node: Frame Apply, Next: Frame Filter Management, Prev: Frame Info, Up: Stack 8.5 Applying a Command to Several Frames. ========================================= `frame apply [all | COUNT | -COUNT | level LEVEL...] [OPTION]... COMMAND' The `frame apply' command allows you to apply the named COMMAND to one or more frames. ``all'' Specify `all' to apply COMMAND to all frames. `COUNT' Use COUNT to apply COMMAND to the innermost COUNT frames, where COUNT is a positive number. `-COUNT' Use -COUNT to apply COMMAND to the outermost COUNT frames, where COUNT is a positive number. ``level'' Use `level' to apply COMMAND to the set of frames identified by the LEVEL list. LEVEL is a frame level or a range of frame levels as LEVEL1-LEVEL2. The frame level is the number shown in the first field of the `backtrace' command output. E.g., `2-4 6-8 3' indicates to apply COMMAND for the frames at levels 2, 3, 4, 6, 7, 8, and then again on frame at level 3. Note that the frames on which `frame apply' applies a command are also influenced by the `set backtrace' settings such as `set backtrace past-main' and `set backtrace limit N'. *Note Backtraces: Backtrace. The `frame apply' command also supports a number of options that allow overriding relevant `set backtrace' settings: `-past-main [`on'|`off']' Whether backtraces should continue past `main'. Related setting: *Note set backtrace past-main::. `-past-entry [`on'|`off']' Whether backtraces should continue past the entry point of a program. Related setting: *Note set backtrace past-entry::. By default, GDB displays some frame information before the output produced by COMMAND, and an error raised during the execution of a COMMAND will abort `frame apply'. The following options can be used to fine-tune these behaviors: `-c' The flag `-c', which stands for `continue', causes any errors in COMMAND to be displayed, and the execution of `frame apply' then continues. `-s' The flag `-s', which stands for `silent', causes any errors or empty output produced by a COMMAND to be silently ignored. That is, the execution continues, but the frame information and errors are not printed. `-q' The flag `-q' (`quiet') disables printing the frame information. The following example shows how the flags `-c' and `-s' are working when applying the command `p j' to all frames, where variable `j' can only be successfully printed in the outermost `#1 main' frame. (gdb) frame apply all p j #0 some_function (i=5) at fun.c:4 No symbol "j" in current context. (gdb) frame apply all -c p j #0 some_function (i=5) at fun.c:4 No symbol "j" in current context. #1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11 $1 = 5 (gdb) frame apply all -s p j #1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11 $2 = 5 (gdb) By default, `frame apply', prints the frame location information before the command output: (gdb) frame apply all p $sp #0 some_function (i=5) at fun.c:4 $4 = (void *) 0xffffd1e0 #1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11 $5 = (void *) 0xffffd1f0 (gdb) If the flag `-q' is given, no frame information is printed: (gdb) frame apply all -q p $sp $12 = (void *) 0xffffd1e0 $13 = (void *) 0xffffd1f0 (gdb) `faas COMMAND' Shortcut for `frame apply all -s COMMAND'. Applies COMMAND on all frames, ignoring errors and empty output. It can for example be used to print a local variable or a function argument without knowing the frame where this variable or argument is, using: (gdb) faas p some_local_var_i_do_not_remember_where_it_is The `faas' command accepts the same options as the `frame apply' command. *Note frame apply: Frame Apply. Note that the command `tfaas COMMAND' applies COMMAND on all frames of all threads. See *Note Threads: Threads.  File: gdb.info, Node: Frame Filter Management, Prev: Frame Apply, Up: Stack 8.6 Management of Frame Filters. ================================ Frame filters are Python based utilities to manage and decorate the output of frames. *Note Frame Filter API::, for further information. Managing frame filters is performed by several commands available within GDB, detailed here. `info frame-filter' Print a list of installed frame filters from all dictionaries, showing their name, priority and enabled status. `disable frame-filter FILTER-DICTIONARY FILTER-NAME' Disable a frame filter in the dictionary matching FILTER-DICTIONARY and FILTER-NAME. The FILTER-DICTIONARY may be `all', `global', `progspace', or the name of the object file where the frame filter dictionary resides. When `all' is specified, all frame filters across all dictionaries are disabled. The FILTER-NAME is the name of the frame filter and is used when `all' is not the option for FILTER-DICTIONARY. A disabled frame-filter is not deleted, it may be enabled again later. `enable frame-filter FILTER-DICTIONARY FILTER-NAME' Enable a frame filter in the dictionary matching FILTER-DICTIONARY and FILTER-NAME. The FILTER-DICTIONARY may be `all', `global', `progspace' or the name of the object file where the frame filter dictionary resides. When `all' is specified, all frame filters across all dictionaries are enabled. The FILTER-NAME is the name of the frame filter and is used when `all' is not the option for FILTER-DICTIONARY. Example: (gdb) info frame-filter global frame-filters: Priority Enabled Name 1000 No PrimaryFunctionFilter 100 Yes Reverse progspace /build/test frame-filters: Priority Enabled Name 100 Yes ProgspaceFilter objfile /build/test frame-filters: Priority Enabled Name 999 Yes BuildProgramFilter (gdb) disable frame-filter /build/test BuildProgramFilter (gdb) info frame-filter global frame-filters: Priority Enabled Name 1000 No PrimaryFunctionFilter 100 Yes Reverse progspace /build/test frame-filters: Priority Enabled Name 100 Yes ProgspaceFilter objfile /build/test frame-filters: Priority Enabled Name 999 No BuildProgramFilter (gdb) enable frame-filter global PrimaryFunctionFilter (gdb) info frame-filter global frame-filters: Priority Enabled Name 1000 Yes PrimaryFunctionFilter 100 Yes Reverse progspace /build/test frame-filters: Priority Enabled Name 100 Yes ProgspaceFilter objfile /build/test frame-filters: Priority Enabled Name 999 No BuildProgramFilter `set frame-filter priority FILTER-DICTIONARY FILTER-NAME PRIORITY' Set the PRIORITY of a frame filter in the dictionary matching FILTER-DICTIONARY, and the frame filter name matching FILTER-NAME. The FILTER-DICTIONARY may be `global', `progspace' or the name of the object file where the frame filter dictionary resides. The PRIORITY is an integer. `show frame-filter priority FILTER-DICTIONARY FILTER-NAME' Show the PRIORITY of a frame filter in the dictionary matching FILTER-DICTIONARY, and the frame filter name matching FILTER-NAME. The FILTER-DICTIONARY may be `global', `progspace' or the name of the object file where the frame filter dictionary resides. Example: (gdb) info frame-filter global frame-filters: Priority Enabled Name 1000 Yes PrimaryFunctionFilter 100 Yes Reverse progspace /build/test frame-filters: Priority Enabled Name 100 Yes ProgspaceFilter objfile /build/test frame-filters: Priority Enabled Name 999 No BuildProgramFilter (gdb) set frame-filter priority global Reverse 50 (gdb) info frame-filter global frame-filters: Priority Enabled Name 1000 Yes PrimaryFunctionFilter 50 Yes Reverse progspace /build/test frame-filters: Priority Enabled Name 100 Yes ProgspaceFilter objfile /build/test frame-filters: Priority Enabled Name 999 No BuildProgramFilter  File: gdb.info, Node: Source, Next: Data, Prev: Stack, Up: Top 9 Examining Source Files ************************ GDB can print parts of your program's source, since the debugging information recorded in the program tells GDB what source files were used to build it. When your program stops, GDB spontaneously prints the line where it stopped. Likewise, when you select a stack frame (*note Selecting a Frame: Selection.), GDB prints the line where execution in that frame has stopped. You can print other portions of source files by explicit command. If you use GDB through its GNU Emacs interface, you may prefer to use Emacs facilities to view source; see *Note Using GDB under GNU Emacs: Emacs. * Menu: * List:: Printing source lines * Location Specifications:: How to specify code locations * Edit:: Editing source files * Search:: Searching source files * Source Path:: Specifying source directories * Machine Code:: Source and machine code * Disable Reading Source:: Disable Reading Source Code  File: gdb.info, Node: List, Next: Location Specifications, Up: Source 9.1 Printing Source Lines ========================= To print lines from a source file, use the `list' command (abbreviated `l'). By default, ten lines are printed. There are several ways to specify what part of the file you want to print; see *Note Location Specifications::, for the full list. Here are the forms of the `list' command most commonly used: `list LINENUM' Print lines centered around line number LINENUM in the current source file. `list FUNCTION' Print lines centered around the beginning of function FUNCTION. `list' Print more lines. If the last lines printed were printed with a `list' command, this prints lines following the last lines printed; however, if the last line printed was a solitary line printed as part of displaying a stack frame (*note Examining the Stack: Stack.), this prints lines centered around that line. If no `list' command has been used and no solitary line was printed, it prints the lines around the function `main'. `list +' Same as using with no arguments. `list -' Print lines just before the lines last printed. `list .' Print the lines surrounding the point of execution within the currently selected frame. If the inferior is not running, print lines around the start of the main function instead. By default, GDB prints ten source lines with any of these forms of the `list' command. You can change this using `set listsize': `set listsize COUNT' `set listsize unlimited' Make the `list' command display COUNT source lines (unless the `list' argument explicitly specifies some other number). Setting COUNT to `unlimited' or 0 means there's no limit. `show listsize' Display the number of lines that `list' prints. Repeating a `list' command with discards the argument, so it is equivalent to typing just `list'. This is more useful than listing the same lines again. An exception is made for an argument of `-'; that argument is preserved in repetition so that each repetition moves up in the source file. In general, the `list' command expects you to supply zero, one or two location specs. These location specs are interpreted to resolve to source code lines; there are several ways of writing them (*note Location Specifications::), but the effect is always to resolve to some source lines to display. Here is a complete description of the possible arguments for `list': `list LOCSPEC' Print lines centered around the line or lines of all the code locations that result from resolving LOCSPEC. `list FIRST,LAST' Print lines from FIRST to LAST. Both arguments are location specs. When a `list' command has two location specs, and the source file of the second location spec is omitted, this refers to the same source file as the first location spec. If either FIRST or LAST resolve to more than one source line in the program, then the list command shows the list of resolved source lines and does not proceed with the source code listing. `list ,LAST' Print lines ending with LAST. Likewise, if LAST resolves to more than one source line in the program, then the list command prints the list of resolved source lines and does not proceed with the source code listing. `list FIRST,' Print lines starting with FIRST. `list +' Print lines just after the lines last printed. `list -' Print lines just before the lines last printed. `list' As described in the preceding table.  File: gdb.info, Node: Location Specifications, Next: Edit, Prev: List, Up: Source 9.2 Location Specifications =========================== Several GDB commands accept arguments that specify a location or locations of your program's code. Many times locations are specified using a source line number, but they can also be specified by a function name, an address, a label, etc. The different forms of specifying a location that GDB recognizes are collectively known as forms of "location specification", or "location spec". This section documents the forms of specifying locations that GDB recognizes. When you specify a location, GDB needs to find the place in your program, known as "code location", that corresponds to the given location spec. We call this process of finding actual code locations corresponding to a location spec "location resolution". A concrete code location in your program is uniquely identifiable by a set of several attributes: its source line number, the name of its source file, the fully-qualified and prototyped function in which it is defined, and an instruction address. Because each inferior has its own address space, the inferior number is also a necessary part of these attributes. By contrast, location specs you type will many times omit some of these attributes. For example, it is customary to specify just the source line number to mean a line in the current source file, or specify just the basename of the file, omitting its directories. In other words, a location spec is usually incomplete, a kind of blueprint, and GDB needs to complete the missing attributes by using the implied defaults, and by considering the source code and the debug information available to it. This is what location resolution is about. The resolution of an incomplete location spec can produce more than a single code location, if the spec doesn't allow distinguishing between them. Here are some examples of situations that result in a location spec matching multiple code locations in your program: * The location spec specifies a function name, and there are several functions in the program which have that name. (To distinguish between them, you can specify a fully-qualified and prototyped function name, such as `A::func(int)' instead of just `func'.) * The location spec specifies a source file name, and there are several source files in the program that share the same name, for example several files with the same basename in different subdirectories. (To distinguish between them, specify enough leading directories with the file name.) * For a C++ constructor, the GCC compiler generates several instances of the function body, used in different cases, but their source-level names are identical. * For a C++ template function, a given line in the function can correspond to any number of instantiations. * For an inlined function, a given source line can correspond to several actual code locations with that function's inlined code. Resolution of a location spec can also fail to produce a complete code location, or even fail to produce any code location. Here are some examples of such situations: * Some parts of the program lack detailed enough debug info, so the resolved code location lacks some attributes, like source file name and line number, leaving just the instruction address and perhaps also a function name. Such an incomplete code location is only usable in contexts that work with addresses and/or function names. Some commands can only work with complete code locations. * The location spec specifies a function name, and there are no functions in the program by that name, or they only exist in a yet-unloaded shared library. * The location spec specifies a source file name, and there are no source files in the program by that name, or they only exist in a yet-unloaded shared library. * The location spec specifies both a source file name and a source line number, and even though there are source files in the program that match the file name, none of those files has the specified line number. Locations may be specified using three different formats: linespec locations, explicit locations, or address locations. The following subsections describe these formats. * Menu: * Linespec Locations:: Linespec locations * Explicit Locations:: Explicit locations * Address Locations:: Address locations  File: gdb.info, Node: Linespec Locations, Next: Explicit Locations, Up: Location Specifications 9.2.1 Linespec Locations ------------------------ A "linespec" is a colon-separated list of source location parameters such as file name, function name, etc. Here are all the different ways of specifying a linespec: `LINENUM' Specifies the line number LINENUM of the current source file. `-OFFSET' `+OFFSET' Specifies the line OFFSET lines before or after the "current line". For the `list' command, the current line is the last one printed; for the breakpoint commands, this is the line at which execution stopped in the currently selected "stack frame" (*note Frames: Frames, for a description of stack frames.) When used as the second of the two linespecs in a `list' command, this specifies the line OFFSET lines up or down from the first linespec. `FILENAME:LINENUM' Specifies the line LINENUM in the source file FILENAME. If FILENAME is a relative file name, then it will match any source file name with the same trailing components. For example, if FILENAME is `gcc/expr.c', then it will match source file name of `/build/trunk/gcc/expr.c', but not `/build/trunk/libcpp/expr.c' or `/build/trunk/gcc/x-expr.c'. `FUNCTION' Specifies the line that begins the body of the function FUNCTION. For example, in C, this is the line with the open brace. By default, in C++ and Ada, FUNCTION is interpreted as specifying all functions named FUNCTION in all scopes. For C++, this means in all namespaces and classes. For Ada, this means in all packages. For example, assuming a program with C++ symbols named `A::B::func' and `B::func', both commands `break func' and `break B::func' set a breakpoint on both symbols. Commands that accept a linespec let you override this with the `-qualified' option. For example, `break -qualified func' sets a breakpoint on a free-function named `func' ignoring any C++ class methods and namespace functions called `func'. *Note Explicit Locations::. `FUNCTION:LABEL' Specifies the line where LABEL appears in FUNCTION. `FILENAME:FUNCTION' Specifies the line that begins the body of the function FUNCTION in the file FILENAME. You only need the file name with a function name to avoid ambiguity when there are identically named functions in different source files. `LABEL' Specifies the line at which the label named LABEL appears in the function corresponding to the currently selected stack frame. If there is no current selected stack frame (for instance, if the inferior is not running), then GDB will not search for a label. `-pstap|-probe-stap [OBJFILE:[PROVIDER:]]NAME' The GNU/Linux tool `SystemTap' provides a way for applications to embed static probes. *Note Static Probe Points::, for more information on finding and using static probes. This form of linespec specifies the location of such a static probe. If OBJFILE is given, only probes coming from that shared library or executable matching OBJFILE as a regular expression are considered. If PROVIDER is given, then only probes from that provider are considered. If several probes match the spec, GDB will insert a breakpoint at each one of those probes.  File: gdb.info, Node: Explicit Locations, Next: Address Locations, Prev: Linespec Locations, Up: Location Specifications 9.2.2 Explicit Locations ------------------------ "Explicit locations" allow the user to directly specify the source location's parameters using option-value pairs. Explicit locations are useful when several functions, labels, or file names have the same name (base name for files) in the program's sources. In these cases, explicit locations point to the source line you meant more accurately and unambiguously. Also, using explicit locations might be faster in large programs. For example, the linespec `foo:bar' may refer to a function `bar' defined in the file named `foo' or the label `bar' in a function named `foo'. GDB must search either the file system or the symbol table to know. The list of valid explicit location options is summarized in the following table: `-source FILENAME' The value specifies the source file name. To differentiate between files with the same base name, prepend as many directories as is necessary to uniquely identify the desired file, e.g., `foo/bar/baz.c'. Otherwise GDB will use the first file it finds with the given base name. This option requires the use of either `-function' or `-line'. `-function FUNCTION' The value specifies the name of a function. Operations on function locations unmodified by other options (such as `-label' or `-line') refer to the line that begins the body of the function. In C, for example, this is the line with the open brace. By default, in C++ and Ada, FUNCTION is interpreted as specifying all functions named FUNCTION in all scopes. For C++, this means in all namespaces and classes. For Ada, this means in all packages. For example, assuming a program with C++ symbols named `A::B::func' and `B::func', both commands `break -function func' and `break -function B::func' set a breakpoint on both symbols. You can use the `-qualified' flag to override this (see below). `-qualified' This flag makes GDB interpret a function name specified with `-function' as a complete fully-qualified name. For example, assuming a C++ program with symbols named `A::B::func' and `B::func', the `break -qualified -function B::func' command sets a breakpoint on `B::func', only. (Note: the `-qualified' option can precede a linespec as well (*note Linespec Locations::), so the particular example above could be simplified as `break -qualified B::func'.) `-label LABEL' The value specifies the name of a label. When the function name is not specified, the label is searched in the function of the currently selected stack frame. `-line NUMBER' The value specifies a line offset for the location. The offset may either be absolute (`-line 3') or relative (`-line +3'), depending on the command. When specified without any other options, the line offset is relative to the current line. Explicit location options may be abbreviated by omitting any non-unique trailing characters from the option name, e.g., `break -s main.c -li 3'.  File: gdb.info, Node: Address Locations, Prev: Explicit Locations, Up: Location Specifications 9.2.3 Address Locations ----------------------- "Address locations" indicate a specific program address. They have the generalized form *ADDRESS. For line-oriented commands, such as `list' and `edit', this specifies a source line that contains ADDRESS. For `break' and other breakpoint-oriented commands, this can be used to set breakpoints in parts of your program which do not have debugging information or source files. Here ADDRESS may be any expression valid in the current working language (*note working language: Languages.) that specifies a code address. In addition, as a convenience, GDB extends the semantics of expressions used in locations to cover several situations that frequently occur during debugging. Here are the various forms of ADDRESS: `EXPRESSION' Any expression valid in the current working language. `FUNCADDR' An address of a function or procedure derived from its name. In C, C++, Objective-C, Fortran, minimal, and assembly, this is simply the function's name FUNCTION (and actually a special case of a valid expression). In Pascal and Modula-2, this is `&FUNCTION'. In Ada, this is `FUNCTION'Address' (although the Pascal form also works). This form specifies the address of the function's first instruction, before the stack frame and arguments have been set up. `'FILENAME':FUNCADDR' Like FUNCADDR above, but also specifies the name of the source file explicitly. This is useful if the name of the function does not specify the function unambiguously, e.g., if there are several functions with identical names in different source files.  File: gdb.info, Node: Edit, Next: Search, Prev: Location Specifications, Up: Source 9.3 Editing Source Files ======================== To edit the lines in a source file, use the `edit' command. The editing program of your choice is invoked with the current line set to the active line in the program. Alternatively, there are several ways to specify what part of the file you want to print if you want to see other parts of the program: `edit LOCSPEC' Edit the source file of the code location that results from resolving `locspec'. Editing starts at the source file and source line `locspec' resolves to. *Note Location Specifications::, for all the possible forms of the LOCSPEC argument. If `locspec' resolves to more than one source line in your program, then the command prints the list of resolved source lines and does not proceed with the editing. Here are the forms of the `edit' command most commonly used: `edit NUMBER' Edit the current source file with NUMBER as the active line number. `edit FUNCTION' Edit the file containing FUNCTION at the beginning of its definition. 9.3.1 Choosing your Editor -------------------------- You can customize GDB to use any editor you want (1). By default, it is `/bin/ex', but you can change this by setting the environment variable `EDITOR' before using GDB. For example, to configure GDB to use the `vi' editor, you could use these commands with the `sh' shell: EDITOR=/usr/bin/vi export EDITOR gdb ... or in the `csh' shell, setenv EDITOR /usr/bin/vi gdb ... ---------- Footnotes ---------- (1) The only restriction is that your editor (say `ex'), recognizes the following command-line syntax: ex +NUMBER file The optional numeric value +NUMBER specifies the number of the line in the file where to start editing.  File: gdb.info, Node: Search, Next: Source Path, Prev: Edit, Up: Source 9.4 Searching Source Files ========================== There are two commands for searching through the current source file for a regular expression. `forward-search REGEXP' `search REGEXP' The command `forward-search REGEXP' checks each line, starting with the one following the last line listed, for a match for REGEXP. It lists the line that is found. You can use the synonym `search REGEXP' or abbreviate the command name as `fo'. `reverse-search REGEXP' The command `reverse-search REGEXP' checks each line, starting with the one before the last line listed and going backward, for a match for REGEXP. It lists the line that is found. You can abbreviate this command as `rev'.  File: gdb.info, Node: Source Path, Next: Machine Code, Prev: Search, Up: Source 9.5 Specifying Source Directories ================================= Executable programs sometimes do not record the directories of the source files from which they were compiled, just the names. Even when they do, the directories could be moved between the compilation and your debugging session. GDB has a list of directories to search for source files; this is called the "source path". Each time GDB wants a source file, it tries all the directories in the list, in the order they are present in the list, until it finds a file with the desired name. For example, suppose an executable references the file `/usr/src/foo-1.0/lib/foo.c', does not record a compilation directory, and the "source path" is `/mnt/cross'. GDB would look for the source file in the following locations: 1. `/usr/src/foo-1.0/lib/foo.c' 2. `/mnt/cross/usr/src/foo-1.0/lib/foo.c' 3. `/mnt/cross/foo.c' If the source file is not present at any of the above locations then an error is printed. GDB does not look up the parts of the source file name, such as `/mnt/cross/src/foo-1.0/lib/foo.c'. Likewise, the subdirectories of the source path are not searched: if the source path is `/mnt/cross', and the binary refers to `foo.c', GDB would not find it under `/mnt/cross/usr/src/foo-1.0/lib'. Plain file names, relative file names with leading directories, file names containing dots, etc. are all treated as described above, except that non-absolute file names are not looked up literally. If the "source path" is `/mnt/cross', the source file is recorded as `../lib/foo.c', and no compilation directory is recorded, then GDB will search in the following locations: 1. `/mnt/cross/../lib/foo.c' 2. `/mnt/cross/foo.c' The "source path" will always include two special entries `$cdir' and `$cwd', these refer to the compilation directory (if one is recorded) and the current working directory respectively. `$cdir' causes GDB to search within the compilation directory, if one is recorded in the debug information. If no compilation directory is recorded in the debug information then `$cdir' is ignored. `$cwd' is not the same as `.'--the former tracks the current working directory as it changes during your GDB session, while the latter is immediately expanded to the current directory at the time you add an entry to the source path. If a compilation directory is recorded in the debug information, and GDB has not found the source file after the first search using "source path", then GDB will combine the compilation directory and the filename, and then search for the source file again using the "source path". For example, if the executable records the source file as `/usr/src/foo-1.0/lib/foo.c', the compilation directory is recorded as `/project/build', and the "source path" is `/mnt/cross:$cdir:$cwd' while the current working directory of the GDB session is `/home/user', then GDB will search for the source file in the following locations: 1. `/usr/src/foo-1.0/lib/foo.c' 2. `/mnt/cross/usr/src/foo-1.0/lib/foo.c' 3. `/project/build/usr/src/foo-1.0/lib/foo.c' 4. `/home/user/usr/src/foo-1.0/lib/foo.c' 5. `/mnt/cross/project/build/usr/src/foo-1.0/lib/foo.c' 6. `/project/build/project/build/usr/src/foo-1.0/lib/foo.c' 7. `/home/user/project/build/usr/src/foo-1.0/lib/foo.c' 8. `/mnt/cross/foo.c' 9. `/project/build/foo.c' 10. `/home/user/foo.c' If the file name in the previous example had been recorded in the executable as a relative path rather than an absolute path, then the first look up would not have occurred, but all of the remaining steps would be similar. When searching for source files on MS-DOS and MS-Windows, where absolute paths start with a drive letter (e.g. `C:/project/foo.c'), GDB will remove the drive letter from the file name before appending it to a search directory from "source path"; for instance if the executable references the source file `C:/project/foo.c' and "source path" is set to `D:/mnt/cross', then GDB will search in the following locations for the source file: 1. `C:/project/foo.c' 2. `D:/mnt/cross/project/foo.c' 3. `D:/mnt/cross/foo.c' Note that the executable search path is _not_ used to locate the source files. Whenever you reset or rearrange the source path, GDB clears out any information it has cached about where source files are found and where each line is in the file. When you start GDB, its source path includes only `$cdir' and `$cwd', in that order. To add other directories, use the `directory' command. The search path is used to find both program source files and GDB script files (read using the `-command' option and `source' command). In addition to the source path, GDB provides a set of commands that manage a list of source path substitution rules. A "substitution rule" specifies how to rewrite source directories stored in the program's debug information in case the sources were moved to a different directory between compilation and debugging. A rule is made of two strings, the first specifying what needs to be rewritten in the path, and the second specifying how it should be rewritten. In *Note set substitute-path::, we name these two parts FROM and TO respectively. GDB does a simple string replacement of FROM with TO at the start of the directory part of the source file name, and uses that result instead of the original file name to look up the sources. Using the previous example, suppose the `foo-1.0' tree has been moved from `/usr/src' to `/mnt/cross', then you can tell GDB to replace `/usr/src' in all source path names with `/mnt/cross'. The first lookup will then be `/mnt/cross/foo-1.0/lib/foo.c' in place of the original location of `/usr/src/foo-1.0/lib/foo.c'. To define a source path substitution rule, use the `set substitute-path' command (*note set substitute-path::). To avoid unexpected substitution results, a rule is applied only if the FROM part of the directory name ends at a directory separator. For instance, a rule substituting `/usr/source' into `/mnt/cross' will be applied to `/usr/source/foo-1.0' but not to `/usr/sourceware/foo-2.0'. And because the substitution is applied only at the beginning of the directory name, this rule will not be applied to `/root/usr/source/baz.c' either. In many cases, you can achieve the same result using the `directory' command. However, `set substitute-path' can be more efficient in the case where the sources are organized in a complex tree with multiple subdirectories. With the `directory' command, you need to add each subdirectory of your project. If you moved the entire tree while preserving its internal organization, then `set substitute-path' allows you to direct the debugger to all the sources with one single command. `set substitute-path' is also more than just a shortcut command. The source path is only used if the file at the original location no longer exists. On the other hand, `set substitute-path' modifies the debugger behavior to look at the rewritten location instead. So, if for any reason a source file that is not relevant to your executable is located at the original location, a substitution rule is the only method available to point GDB at the new location. You can configure a default source path substitution rule by configuring GDB with the `--with-relocated-sources=DIR' option. The DIR should be the name of a directory under GDB's configured prefix (set with `--prefix' or `--exec-prefix'), and directory names in debug information under DIR will be adjusted automatically if the installed GDB is moved to a new location. This is useful if GDB, libraries or executables with debug information and corresponding source code are being moved together. `directory DIRNAME ...' `dir DIRNAME ...' Add directory DIRNAME to the front of the source path. Several directory names may be given to this command, separated by `:' (`;' on MS-DOS and MS-Windows, where `:' usually appears as part of absolute file names) or whitespace. You may specify a directory that is already in the source path; this moves it forward, so GDB searches it sooner. The special strings `$cdir' (to refer to the compilation directory, if one is recorded), and `$cwd' (to refer to the current working directory) can also be included in the list of directories DIRNAME. Though these will already be in the source path they will be moved forward in the list so GDB searches them sooner. `directory' Reset the source path to its default value (`$cdir:$cwd' on Unix systems). This requires confirmation. `set directories PATH-LIST' Set the source path to PATH-LIST. `$cdir:$cwd' are added if missing. `show directories' Print the source path: show which directories it contains. `set substitute-path FROM TO' Define a source path substitution rule, and add it at the end of the current list of existing substitution rules. If a rule with the same FROM was already defined, then the old rule is also deleted. For example, if the file `/foo/bar/baz.c' was moved to `/mnt/cross/baz.c', then the command (gdb) set substitute-path /foo/bar /mnt/cross will tell GDB to replace `/foo/bar' with `/mnt/cross', which will allow GDB to find the file `baz.c' even though it was moved. In the case when more than one substitution rule have been defined, the rules are evaluated one by one in the order where they have been defined. The first one matching, if any, is selected to perform the substitution. For instance, if we had entered the following commands: (gdb) set substitute-path /usr/src/include /mnt/include (gdb) set substitute-path /usr/src /mnt/src GDB would then rewrite `/usr/src/include/defs.h' into `/mnt/include/defs.h' by using the first rule. However, it would use the second rule to rewrite `/usr/src/lib/foo.c' into `/mnt/src/lib/foo.c'. `unset substitute-path [path]' If a path is specified, search the current list of substitution rules for a rule that would rewrite that path. Delete that rule if found. A warning is emitted by the debugger if no rule could be found. If no path is specified, then all substitution rules are deleted. `show substitute-path [path]' If a path is specified, then print the source path substitution rule which would rewrite that path, if any. If no path is specified, then print all existing source path substitution rules. If your source path is cluttered with directories that are no longer of interest, GDB may sometimes cause confusion by finding the wrong versions of source. You can correct the situation as follows: 1. Use `directory' with no argument to reset the source path to its default value. 2. Use `directory' with suitable arguments to reinstall the directories you want in the source path. You can add all the directories in one command.  File: gdb.info, Node: Machine Code, Next: Disable Reading Source, Prev: Source Path, Up: Source 9.6 Source and Machine Code =========================== You can use the command `info line' to map source lines to program addresses (and vice versa), and the command `disassemble' to display a range of addresses as machine instructions. You can use the command `set disassemble-next-line' to set whether to disassemble next source line when execution stops. When run under GNU Emacs mode, the `info line' command causes the arrow to point to the line specified. Also, `info line' prints addresses in symbolic form as well as hex. `info line' `info line LOCSPEC' Print the starting and ending addresses of the compiled code for the source lines of the code locations that result from resolving LOCSPEC. *Note Location Specifications::, for the various forms of LOCSPEC. With no LOCSPEC, information about the current source line is printed. For example, we can use `info line' to discover the location of the object code for the first line of function `m4_changequote': (gdb) info line m4_changequote Line 895 of "builtin.c" starts at pc 0x634c and \ ends at 0x6350 . We can also inquire, using `*ADDR' as the form for LOCSPEC, what source line covers a particular address ADDR: (gdb) info line *0x63ff Line 926 of "builtin.c" starts at pc 0x63e4 and \ ends at 0x6404 . After `info line', the default address for the `x' command is changed to the starting address of the line, so that `x/i' is sufficient to begin examining the machine code (*note Examining Memory: Memory.). Also, this address is saved as the value of the convenience variable `$_' (*note Convenience Variables: Convenience Vars.). After `info line', using `info line' again without specifying a location will display information about the next source line. `disassemble' `disassemble /m' `disassemble /s' `disassemble /r' `disassemble /b' This specialized command dumps a range of memory as machine instructions. It can also print mixed source+disassembly by specifying the `/m' or `/s' modifier and print the raw instructions in hex as well as in symbolic form by specifying the `/r' or `/b' modifier. Only one of `/m' and `/s' can be used, attempting to use both flag will give an error. Only one of `/r' and `/b' can be used, attempting to use both flag will give an error. The default memory range is the function surrounding the program counter of the selected frame. A single argument to this command is a program counter value; GDB dumps the function surrounding this value. When two arguments are given, they should be separated by a comma, possibly surrounded by whitespace. The arguments specify a range of addresses to dump, in one of two forms: `START,END' the addresses from START (inclusive) to END (exclusive) `START,+LENGTH' the addresses from START (inclusive) to `START+LENGTH' (exclusive). When 2 arguments are specified, the name of the function is also printed (since there could be several functions in the given range). The argument(s) can be any expression yielding a numeric value, such as `0x32c4', `&main+10' or `$pc - 8'. If the range of memory being disassembled contains current program counter, the instruction at that location is shown with a `=>' marker. The following example shows the disassembly of a range of addresses of HP PA-RISC 2.0 code: (gdb) disas 0x32c4, 0x32e4 Dump of assembler code from 0x32c4 to 0x32e4: 0x32c4 : addil 0,dp 0x32c8 : ldw 0x22c(sr0,r1),r26 0x32cc : ldil 0x3000,r31 0x32d0 : ble 0x3f8(sr4,r31) 0x32d4 : ldo 0(r31),rp 0x32d8 : addil -0x800,dp 0x32dc : ldo 0x588(r1),r26 0x32e0 : ldil 0x3000,r31 End of assembler dump. The following two examples are for RISC-V, and demonstrates the difference between the `/r' and `/b' modifiers. First with `/b', the bytes of the instruction are printed, in hex, in memory order: (gdb) disassemble /b 0x00010150,0x0001015c Dump of assembler code from 0x10150 to 0x1015c: 0x00010150 : 22 dc sw s0,56(sp) 0x00010152 : 80 00 addi s0,sp,64 0x00010154 : 23 26 a4 fe sw a0,-20(s0) 0x00010158 : 23 24 b4 fe sw a1,-24(s0) End of assembler dump. In contrast, with `/r' the bytes of the instruction are displayed in the instruction order, for RISC-V this means that the bytes have been swapped to little-endian order: (gdb) disassemble /r 0x00010150,0x0001015c Dump of assembler code from 0x10150 to 0x1015c: 0x00010150 : dc22 sw s0,56(sp) 0x00010152 : 0080 addi s0,sp,64 0x00010154 : fea42623 sw a0,-20(s0) 0x00010158 : feb42423 sw a1,-24(s0) End of assembler dump. Here is an example showing mixed source+assembly for Intel x86 with `/m' or `/s', when the program is stopped just after function prologue in a non-optimized function with no inline code. (gdb) disas /m main Dump of assembler code for function main: 5 { 0x08048330 <+0>: push %ebp 0x08048331 <+1>: mov %esp,%ebp 0x08048333 <+3>: sub $0x8,%esp 0x08048336 <+6>: and $0xfffffff0,%esp 0x08048339 <+9>: sub $0x10,%esp 6 printf ("Hello.\n"); => 0x0804833c <+12>: movl $0x8048440,(%esp) 0x08048343 <+19>: call 0x8048284 7 return 0; 8 } 0x08048348 <+24>: mov $0x0,%eax 0x0804834d <+29>: leave 0x0804834e <+30>: ret End of assembler dump. The `/m' option is deprecated as its output is not useful when there is either inlined code or re-ordered code. The `/s' option is the preferred choice. Here is an example for AMD x86-64 showing the difference between `/m' output and `/s' output. This example has one inline function defined in a header file, and the code is compiled with `-O2' optimization. Note how the `/m' output is missing the disassembly of several instructions that are present in the `/s' output. `foo.h': int foo (int a) { if (a < 0) return a * 2; if (a == 0) return 1; return a + 10; } `foo.c': #include "foo.h" volatile int x, y; int main () { x = foo (y); return 0; } (gdb) disas /m main Dump of assembler code for function main: 5 { 6 x = foo (y); 0x0000000000400400 <+0>: mov 0x200c2e(%rip),%eax # 0x601034 0x0000000000400417 <+23>: mov %eax,0x200c13(%rip) # 0x601030 7 return 0; 8 } 0x000000000040041d <+29>: xor %eax,%eax 0x000000000040041f <+31>: retq 0x0000000000400420 <+32>: add %eax,%eax 0x0000000000400422 <+34>: jmp 0x400417 End of assembler dump. (gdb) disas /s main Dump of assembler code for function main: foo.c: 5 { 6 x = foo (y); 0x0000000000400400 <+0>: mov 0x200c2e(%rip),%eax # 0x601034 foo.h: 4 if (a < 0) 0x0000000000400406 <+6>: test %eax,%eax 0x0000000000400408 <+8>: js 0x400420 6 if (a == 0) 7 return 1; 8 return a + 10; 0x000000000040040a <+10>: lea 0xa(%rax),%edx 0x000000000040040d <+13>: test %eax,%eax 0x000000000040040f <+15>: mov $0x1,%eax 0x0000000000400414 <+20>: cmovne %edx,%eax foo.c: 6 x = foo (y); 0x0000000000400417 <+23>: mov %eax,0x200c13(%rip) # 0x601030 7 return 0; 8 } 0x000000000040041d <+29>: xor %eax,%eax 0x000000000040041f <+31>: retq foo.h: 5 return a * 2; 0x0000000000400420 <+32>: add %eax,%eax 0x0000000000400422 <+34>: jmp 0x400417 End of assembler dump. Here is another example showing raw instructions in hex for AMD x86-64, (gdb) disas /r 0x400281,+10 Dump of assembler code from 0x400281 to 0x40028b: 0x0000000000400281: 38 36 cmp %dh,(%rsi) 0x0000000000400283: 2d 36 34 2e 73 sub $0x732e3436,%eax 0x0000000000400288: 6f outsl %ds:(%rsi),(%dx) 0x0000000000400289: 2e 32 00 xor %cs:(%rax),%al End of assembler dump. Note that the `disassemble' command's address arguments are specified using expressions in your programming language (*note Expressions: Expressions.), not location specs (*note Location Specifications::). So, for example, if you want to disassemble function `bar' in file `foo.c', you must type `disassemble 'foo.c'::bar' and not `disassemble foo.c:bar'. Some architectures have more than one commonly-used set of instruction mnemonics or other syntax. For programs that were dynamically linked and use shared libraries, instructions that call functions or branch to locations in the shared libraries might show a seemingly bogus location--it's actually a location of the relocation table. On some architectures, GDB might be able to resolve these to actual function names. `set disassembler-options OPTION1[,OPTION2...]' This command controls the passing of target specific information to the disassembler. For a list of valid options, please refer to the `-M'/`--disassembler-options' section of the `objdump' manual and/or the output of `objdump --help' (*note objdump: (binutils)objdump.). The default value is the empty string. If it is necessary to specify more than one disassembler option, then multiple options can be placed together into a comma separated list. Currently this command is only supported on targets ARC, ARM, MIPS, PowerPC and S/390. `show disassembler-options' Show the current setting of the disassembler options. `set disassembly-flavor INSTRUCTION-SET' Select the instruction set to use when disassembling the program via the `disassemble' or `x/i' commands. Currently this command is only defined for the Intel x86 family. You can set INSTRUCTION-SET to either `intel' or `att'. The default is `att', the AT&T flavor used by default by Unix assemblers for x86-based targets. `show disassembly-flavor' Show the current setting of the disassembly flavor. `set disassemble-next-line' `show disassemble-next-line' Control whether or not GDB will disassemble the next source line or instruction when execution stops. If ON, GDB will display disassembly of the next source line when execution of the program being debugged stops. This is _in addition_ to displaying the source line itself, which GDB always does if possible. If the next source line cannot be displayed for some reason (e.g., if GDB cannot find the source file, or there's no line info in the debug info), GDB will display disassembly of the next _instruction_ instead of showing the next source line. If AUTO, GDB will display disassembly of next instruction only if the source line cannot be displayed. This setting causes GDB to display some feedback when you step through a function with no line info or whose source file is unavailable. The default is OFF, which means never display the disassembly of the next line or instruction.  File: gdb.info, Node: Disable Reading Source, Prev: Machine Code, Up: Source 9.7 Disable Reading Source Code =============================== In some cases it can be desirable to prevent GDB from accessing source code files. One case where this might be desirable is if the source code files are located over a slow network connection. The following command can be used to control whether GDB should access source code files or not: `set source open [on|off]' `show source open' When this option is `on', which is the default, GDB will access source code files when needed, for example to print source lines when GDB stops, or in response to the `list' command. When this option is `off', GDB will not access source code files.  File: gdb.info, Node: Data, Next: Optimized Code, Prev: Source, Up: Top 10 Examining Data ***************** The usual way to examine data in your program is with the `print' command (abbreviated `p'), or its synonym `inspect'. It evaluates and prints the value of an expression of the language your program is written in (*note Using GDB with Different Languages: Languages.). It may also print the expression using a Python-based pretty-printer (*note Pretty Printing::). `print [[OPTIONS] --] EXPR' `print [[OPTIONS] --] /F EXPR' EXPR is an expression (in the source language). By default the value of EXPR is printed in a format appropriate to its data type; you can choose a different format by specifying `/F', where F is a letter specifying the format; see *Note Output Formats: Output Formats. The `print' command supports a number of options that allow overriding relevant global print settings as set by `set print' subcommands: `-address [`on'|`off']' Set printing of addresses. Related setting: *Note set print address::. `-array [`on'|`off']' Pretty formatting of arrays. Related setting: *Note set print array::. `-array-indexes [`on'|`off']' Set printing of array indexes. Related setting: *Note set print array-indexes::. `-characters NUMBER-OF-CHARACTERS|`elements'|`unlimited'' Set limit on string characters to print. The value `elements' causes the limit on array elements to print to be used. The value `unlimited' causes there to be no limit. Related setting: *Note set print characters::. `-elements NUMBER-OF-ELEMENTS|`unlimited'' Set limit on array elements and optionally string characters to print. See *Note set print characters::, and the `-characters' option above for when this option applies to strings. The value `unlimited' causes there to be no limit. *Note set print elements::, for a related CLI command. `-max-depth DEPTH|`unlimited'' Set the threshold after which nested structures are replaced with ellipsis. Related setting: *Note set print max-depth::. `-nibbles [`on'|`off']' Set whether to print binary values in groups of four bits, known as "nibbles". *Note set print nibbles::. `-memory-tag-violations [`on'|`off']' Set printing of additional information about memory tag violations. *Note set print memory-tag-violations::. `-null-stop [`on'|`off']' Set printing of char arrays to stop at first null char. Related setting: *Note set print null-stop::. `-object [`on'|`off']' Set printing C++ virtual function tables. Related setting: *Note set print object::. `-pretty [`on'|`off']' Set pretty formatting of structures. Related setting: *Note set print pretty::. `-raw-values [`on'|`off']' Set whether to print values in raw form, bypassing any pretty-printers for that value. Related setting: *Note set print raw-values::. `-repeats NUMBER-OF-REPEATS|`unlimited'' Set threshold for repeated print elements. `unlimited' causes all elements to be individually printed. Related setting: *Note set print repeats::. `-static-members [`on'|`off']' Set printing C++ static members. Related setting: *Note set print static-members::. `-symbol [`on'|`off']' Set printing of symbol names when printing pointers. Related setting: *Note set print symbol::. `-union [`on'|`off']' Set printing of unions interior to structures. Related setting: *Note set print union::. `-vtbl [`on'|`off']' Set printing of C++ virtual function tables. Related setting: *Note set print vtbl::. Because the `print' command accepts arbitrary expressions which may look like options (including abbreviations), if you specify any command option, then you must use a double dash (`--') to mark the end of option processing. For example, this prints the value of the `-p' expression: (gdb) print -p While this repeats the last value in the value history (see below) with the `-pretty' option in effect: (gdb) print -p -- Here is an example including both on option and an expression: (gdb) print -pretty -- *myptr $1 = { next = 0x0, flags = { sweet = 1, sour = 1 }, meat = 0x54 "Pork" } `print [OPTIONS]' `print [OPTIONS] /F' If you omit EXPR, GDB displays the last value again (from the "value history"; *note Value History: Value History.). This allows you to conveniently inspect the same value in an alternative format. If the architecture supports memory tagging, the `print' command will display pointer/memory tag mismatches if what is being printed is a pointer or reference type. *Note Memory Tagging::. A more low-level way of examining data is with the `x' command. It examines data in memory at a specified address and prints it in a specified format. *Note Examining Memory: Memory. If you are interested in information about types, or about how the fields of a struct or a class are declared, use the `ptype EXPR' command rather than `print'. *Note Examining the Symbol Table: Symbols. Another way of examining values of expressions and type information is through the Python extension command `explore' (available only if the GDB build is configured with `--with-python'). It offers an interactive way to start at the highest level (or, the most abstract level) of the data type of an expression (or, the data type itself) and explore all the way down to leaf scalar values/fields embedded in the higher level data types. `explore ARG' ARG is either an expression (in the source language), or a type visible in the current context of the program being debugged. The working of the `explore' command can be illustrated with an example. If a data type `struct ComplexStruct' is defined in your C program as struct SimpleStruct { int i; double d; }; struct ComplexStruct { struct SimpleStruct *ss_p; int arr[10]; }; followed by variable declarations as struct SimpleStruct ss = { 10, 1.11 }; struct ComplexStruct cs = { &ss, { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 } }; then, the value of the variable `cs' can be explored using the `explore' command as follows. (gdb) explore cs The value of `cs' is a struct/class of type `struct ComplexStruct' with the following fields: ss_p = arr = Enter the field number of choice: Since the fields of `cs' are not scalar values, you are being prompted to chose the field you want to explore. Let's say you choose the field `ss_p' by entering `0'. Then, since this field is a pointer, you will be asked if it is pointing to a single value. From the declaration of `cs' above, it is indeed pointing to a single value, hence you enter `y'. If you enter `n', then you will be asked if it were pointing to an array of values, in which case this field will be explored as if it were an array. `cs.ss_p' is a pointer to a value of type `struct SimpleStruct' Continue exploring it as a pointer to a single value [y/n]: y The value of `*(cs.ss_p)' is a struct/class of type `struct SimpleStruct' with the following fields: i = 10 .. (Value of type `int') d = 1.1100000000000001 .. (Value of type `double') Press enter to return to parent value: If the field `arr' of `cs' was chosen for exploration by entering `1' earlier, then since it is as array, you will be prompted to enter the index of the element in the array that you want to explore. `cs.arr' is an array of `int'. Enter the index of the element you want to explore in `cs.arr': 5 `(cs.arr)[5]' is a scalar value of type `int'. (cs.arr)[5] = 4 Press enter to return to parent value: In general, at any stage of exploration, you can go deeper towards the leaf values by responding to the prompts appropriately, or hit the return key to return to the enclosing data structure (the higher level data structure). Similar to exploring values, you can use the `explore' command to explore types. Instead of specifying a value (which is typically a variable name or an expression valid in the current context of the program being debugged), you specify a type name. If you consider the same example as above, your can explore the type `struct ComplexStruct' by passing the argument `struct ComplexStruct' to the `explore' command. (gdb) explore struct ComplexStruct By responding to the prompts appropriately in the subsequent interactive session, you can explore the type `struct ComplexStruct' in a manner similar to how the value `cs' was explored in the above example. The `explore' command also has two sub-commands, `explore value' and `explore type'. The former sub-command is a way to explicitly specify that value exploration of the argument is being invoked, while the latter is a way to explicitly specify that type exploration of the argument is being invoked. `explore value EXPR' This sub-command of `explore' explores the value of the expression EXPR (if EXPR is an expression valid in the current context of the program being debugged). The behavior of this command is identical to that of the behavior of the `explore' command being passed the argument EXPR. `explore type ARG' This sub-command of `explore' explores the type of ARG (if ARG is a type visible in the current context of program being debugged), or the type of the value/expression ARG (if ARG is an expression valid in the current context of the program being debugged). If ARG is a type, then the behavior of this command is identical to that of the `explore' command being passed the argument ARG. If ARG is an expression, then the behavior of this command will be identical to that of the `explore' command being passed the type of ARG as the argument. * Menu: * Expressions:: Expressions * Ambiguous Expressions:: Ambiguous Expressions * Variables:: Program variables * Arrays:: Artificial arrays * Output Formats:: Output formats * Memory:: Examining memory * Memory Tagging:: Memory Tagging * Auto Display:: Automatic display * Print Settings:: Print settings * Pretty Printing:: Python pretty printing * Value History:: Value history * Convenience Vars:: Convenience variables * Convenience Funs:: Convenience functions * Registers:: Registers * Floating Point Hardware:: Floating point hardware * Vector Unit:: Vector Unit * OS Information:: Auxiliary data provided by operating system * Memory Region Attributes:: Memory region attributes * Dump/Restore Files:: Copy between memory and a file * Core File Generation:: Cause a program dump its core * Character Sets:: Debugging programs that use a different character set than GDB does * Caching Target Data:: Data caching for targets * Searching Memory:: Searching memory for a sequence of bytes * Value Sizes:: Managing memory allocated for values  File: gdb.info, Node: Expressions, Next: Ambiguous Expressions, Up: Data 10.1 Expressions ================ `print' and many other GDB commands accept an expression and compute its value. Any kind of constant, variable or operator defined by the programming language you are using is valid in an expression in GDB. This includes conditional expressions, function calls, casts, and string constants. It also includes preprocessor macros, if you compiled your program to include this information; see *Note Compilation::. GDB supports array constants in expressions input by the user. The syntax is {ELEMENT, ELEMENT...}. For example, you can use the command `print {1, 2, 3}' to create an array of three integers. If you pass an array to a function or assign it to a program variable, GDB copies the array to memory that is `malloc'ed in the target program. Because C is so widespread, most of the expressions shown in examples in this manual are in C. *Note Using GDB with Different Languages: Languages, for information on how to use expressions in other languages. In this section, we discuss operators that you can use in GDB expressions regardless of your programming language. Casts are supported in all languages, not just in C, because it is so useful to cast a number into a pointer in order to examine a structure at that address in memory. GDB supports these operators, in addition to those common to programming languages: `@@' `@@' is a binary operator for treating parts of memory as arrays. *Note Artificial Arrays: Arrays, for more information. `::' `::' allows you to specify a variable in terms of the file or function where it is defined. *Note Program Variables: Variables. `{TYPE} ADDR' Refers to an object of type TYPE stored at address ADDR in memory. The address ADDR may be any expression whose value is an integer or pointer (but parentheses are required around binary operators, just as in a cast). This construct is allowed regardless of what kind of data is normally supposed to reside at ADDR.  File: gdb.info, Node: Ambiguous Expressions, Next: Variables, Prev: Expressions, Up: Data 10.2 Ambiguous Expressions ========================== Expressions can sometimes contain some ambiguous elements. For instance, some programming languages (notably Ada, C++ and Objective-C) permit a single function name to be defined several times, for application in different contexts. This is called "overloading". Another example involving Ada is generics. A "generic package" is similar to C++ templates and is typically instantiated several times, resulting in the same function name being defined in different contexts. In some cases and depending on the language, it is possible to adjust the expression to remove the ambiguity. For instance in C++, you can specify the signature of the function you want to break on, as in `break FUNCTION(TYPES)'. In Ada, using the fully qualified name of your function often makes the expression unambiguous as well. When an ambiguity that needs to be resolved is detected, the debugger has the capability to display a menu of numbered choices for each possibility, and then waits for the selection with the prompt `>'. The first option is always `[0] cancel', and typing `0 ' aborts the current command. If the command in which the expression was used allows more than one choice to be selected, the next option in the menu is `[1] all', and typing `1 ' selects all possible choices. For example, the following session excerpt shows an attempt to set a breakpoint at the overloaded symbol `String::after'. We choose three particular definitions of that function name: (gdb) b String::after [0] cancel [1] all [2] file:String.cc; line number:867 [3] file:String.cc; line number:860 [4] file:String.cc; line number:875 [5] file:String.cc; line number:853 [6] file:String.cc; line number:846 [7] file:String.cc; line number:735 > 2 4 6 Breakpoint 1 at 0xb26c: file String.cc, line 867. Breakpoint 2 at 0xb344: file String.cc, line 875. Breakpoint 3 at 0xafcc: file String.cc, line 846. Multiple breakpoints were set. Use the "delete" command to delete unwanted breakpoints. (gdb) `set multiple-symbols MODE' This option allows you to adjust the debugger behavior when an expression is ambiguous. By default, MODE is set to `all'. If the command with which the expression is used allows more than one choice, then GDB automatically selects all possible choices. For instance, inserting a breakpoint on a function using an ambiguous name results in a breakpoint inserted on each possible match. However, if a unique choice must be made, then GDB uses the menu to help you disambiguate the expression. For instance, printing the address of an overloaded function will result in the use of the menu. When MODE is set to `ask', the debugger always uses the menu when an ambiguity is detected. Finally, when MODE is set to `cancel', the debugger reports an error due to the ambiguity and the command is aborted. `show multiple-symbols' Show the current value of the `multiple-symbols' setting.  File: gdb.info, Node: Variables, Next: Arrays, Prev: Ambiguous Expressions, Up: Data 10.3 Program Variables ====================== The most common kind of expression to use is the name of a variable in your program. Variables in expressions are understood in the selected stack frame (*note Selecting a Frame: Selection.); they must be either: * global (or file-static) or * visible according to the scope rules of the programming language from the point of execution in that frame This means that in the function foo (a) int a; { bar (a); { int b = test (); bar (b); } } you can examine and use the variable `a' whenever your program is executing within the function `foo', but you can only use or examine the variable `b' while your program is executing inside the block where `b' is declared. There is an exception: you can refer to a variable or function whose scope is a single source file even if the current execution point is not in this file. But it is possible to have more than one such variable or function with the same name (in different source files). If that happens, referring to that name has unpredictable effects. If you wish, you can specify a static variable in a particular function or file by using the colon-colon (`::') notation: FILE::VARIABLE FUNCTION::VARIABLE Here FILE or FUNCTION is the name of the context for the static VARIABLE. In the case of file names, you can use quotes to make sure GDB parses the file name as a single word--for example, to print a global value of `x' defined in `f2.c': (gdb) p 'f2.c'::x The `::' notation is normally used for referring to static variables, since you typically disambiguate uses of local variables in functions by selecting the appropriate frame and using the simple name of the variable. However, you may also use this notation to refer to local variables in frames enclosing the selected frame: void foo (int a) { if (a < 10) bar (a); else process (a); /* Stop here */ } int bar (int a) { foo (a + 5); } For example, if there is a breakpoint at the commented line, here is what you might see when the program stops after executing the call `bar(0)': (gdb) p a $1 = 10 (gdb) p bar::a $2 = 5 (gdb) up 2 #2 0x080483d0 in foo (a=5) at foobar.c:12 (gdb) p a $3 = 5 (gdb) p bar::a $4 = 0 These uses of `::' are very rarely in conflict with the very similar use of the same notation in C++. When they are in conflict, the C++ meaning takes precedence; however, this can be overridden by quoting the file or function name with single quotes. For example, suppose the program is stopped in a method of a class that has a field named `includefile', and there is also an include file named `includefile' that defines a variable, `some_global'. (gdb) p includefile $1 = 23 (gdb) p includefile::some_global A syntax error in expression, near `'. (gdb) p 'includefile'::some_global $2 = 27 _Warning:_ Occasionally, a local variable may appear to have the wrong value at certain points in a function--just after entry to a new scope, and just before exit. You may see this problem when you are stepping by machine instructions. This is because, on most machines, it takes more than one instruction to set up a stack frame (including local variable definitions); if you are stepping by machine instructions, variables may appear to have the wrong values until the stack frame is completely built. On exit, it usually also takes more than one machine instruction to destroy a stack frame; after you begin stepping through that group of instructions, local variable definitions may be gone. This may also happen when the compiler does significant optimizations. To be sure of always seeing accurate values, turn off all optimization when compiling. Another possible effect of compiler optimizations is to optimize unused variables out of existence, or assign variables to registers (as opposed to memory addresses). Depending on the support for such cases offered by the debug info format used by the compiler, GDB might not be able to display values for such local variables. If that happens, GDB will print a message like this: No symbol "foo" in current context. To solve such problems, either recompile without optimizations, or use a different debug info format, if the compiler supports several such formats. *Note Compilation::, for more information on choosing compiler options. *Note C and C++: C, for more information about debug info formats that are best suited to C++ programs. If you ask to print an object whose contents are unknown to GDB, e.g., because its data type is not completely specified by the debug information, GDB will say `'. *Note incomplete type: Symbols, for more about this. If you try to examine or use the value of a (global) variable for which GDB has no type information, e.g., because the program includes no debug information, GDB displays an error message. *Note unknown type: Symbols, for more about unknown types. If you cast the variable to its declared type, GDB gets the variable's value using the cast-to type as the variable's type. For example, in a C program: (gdb) p var 'var' has unknown type; cast it to its declared type (gdb) p (float) var $1 = 3.14 If you append `@@entry' string to a function parameter name you get its value at the time the function got called. If the value is not available an error message is printed. Entry values are available only with some compilers. Entry values are normally also printed at the function parameter list according to *Note set print entry-values::. Breakpoint 1, d (i=30) at gdb.base/entry-value.c:29 29 i++; (gdb) next 30 e (i); (gdb) print i $1 = 31 (gdb) print i@@entry $2 = 30 Strings are identified as arrays of `char' values without specified signedness. Arrays of either `signed char' or `unsigned char' get printed as arrays of 1 byte sized integers. `-fsigned-char' or `-funsigned-char' GCC options have no effect as GDB defines literal string type `"char"' as `char' without a sign. For program code char var0[] = "A"; signed char var1[] = "A"; You get during debugging (gdb) print var0 $1 = "A" (gdb) print var1 $2 = {65 'A', 0 '\0'}  File: gdb.info, Node: Arrays, Next: Output Formats, Prev: Variables, Up: Data 10.4 Artificial Arrays ====================== It is often useful to print out several successive objects of the same type in memory; a section of an array, or an array of dynamically determined size for which only a pointer exists in the program. You can do this by referring to a contiguous span of memory as an "artificial array", using the binary operator `@@'. The left operand of `@@' should be the first element of the desired array and be an individual object. The right operand should be the desired length of the array. The result is an array value whose elements are all of the type of the left argument. The first element is actually the left argument; the second element comes from bytes of memory immediately following those that hold the first element, and so on. Here is an example. If a program says int *array = (int *) malloc (len * sizeof (int)); you can print the contents of `array' with p *array@@len The left operand of `@@' must reside in memory. Array values made with `@@' in this way behave just like other arrays in terms of subscripting, and are coerced to pointers when used in expressions. Artificial arrays most often appear in expressions via the value history (*note Value History: Value History.), after printing one out. Another way to create an artificial array is to use a cast. This re-interprets a value as if it were an array. The value need not be in memory: (gdb) p/x (short[2])0x12345678 $1 = {0x1234, 0x5678} As a convenience, if you leave the array length out (as in `(TYPE[])VALUE') GDB calculates the size to fill the value (as `sizeof(VALUE)/sizeof(TYPE)': (gdb) p/x (short[])0x12345678 $2 = {0x1234, 0x5678} Sometimes the artificial array mechanism is not quite enough; in moderately complex data structures, the elements of interest may not actually be adjacent--for example, if you are interested in the values of pointers in an array. One useful work-around in this situation is to use a convenience variable (*note Convenience Variables: Convenience Vars.) as a counter in an expression that prints the first interesting value, and then repeat that expression via . For instance, suppose you have an array `dtab' of pointers to structures, and you are interested in the values of a field `fv' in each structure. Here is an example of what you might type: set $i = 0 p dtab[$i++]->fv ...  File: gdb.info, Node: Output Formats, Next: Memory, Prev: Arrays, Up: Data 10.5 Output Formats =================== By default, GDB prints a value according to its data type. Sometimes this is not what you want. For example, you might want to print a number in hex, or a pointer in decimal. Or you might want to view data in memory at a certain address as a character string or as an instruction. To do these things, specify an "output format" when you print a value. The simplest use of output formats is to say how to print a value already computed. This is done by starting the arguments of the `print' command with a slash and a format letter. The format letters supported are: `x' Print the binary representation of the value in hexadecimal. `d' Print the binary representation of the value in decimal. `u' Print the binary representation of the value as an decimal, as if it were unsigned. `o' Print the binary representation of the value in octal. `t' Print the binary representation of the value in binary. The letter `t' stands for "two". (1) `a' Print as an address, both absolute in hexadecimal and as an offset from the nearest preceding symbol. You can use this format used to discover where (in what function) an unknown address is located: (gdb) p/a 0x54320 $3 = 0x54320 <_initialize_vx+396> The command `info symbol 0x54320' yields similar results. *Note info symbol: Symbols. `c' Cast the value to an integer (unlike other formats, this does not just reinterpret the underlying bits) and print it as a character constant. This prints both the numerical value and its character representation. The character representation is replaced with the octal escape `\nnn' for characters outside the 7-bit ASCII range. Without this format, GDB displays `char', `unsigned char', and `signed char' data as character constants. Single-byte members of vectors are displayed as integer data. `f' Regard the bits of the value as a floating point number and print using typical floating point syntax. `s' Regard as a string, if possible. With this format, pointers to single-byte data are displayed as null-terminated strings and arrays of single-byte data are displayed as fixed-length strings. Other values are displayed in their natural types. Without this format, GDB displays pointers to and arrays of `char', `unsigned char', and `signed char' as strings. Single-byte members of a vector are displayed as an integer array. `z' Like `x' formatting, the value is treated as an integer and printed as hexadecimal, but leading zeros are printed to pad the value to the size of the integer type. `r' Print using the `raw' formatting. By default, GDB will use a Python-based pretty-printer, if one is available (*note Pretty Printing::). This typically results in a higher-level display of the value's contents. The `r' format bypasses any Python pretty-printer which might exist. For example, to print the program counter in hex (*note Registers::), type p/x $pc Note that no space is required before the slash; this is because command names in GDB cannot contain a slash. To reprint the last value in the value history with a different format, you can use the `print' command with just a format and no expression. For example, `p/x' reprints the last value in hex. ---------- Footnotes ---------- (1) `b' cannot be used because these format letters are also used with the `x' command, where `b' stands for "byte"; see *Note Examining Memory: Memory.  File: gdb.info, Node: Memory, Next: Memory Tagging, Prev: Output Formats, Up: Data 10.6 Examining Memory ===================== You can use the command `x' (for "examine") to examine memory in any of several formats, independently of your program's data types. `x/NFU ADDR' `x ADDR' `x' Use the `x' command to examine memory. N, F, and U are all optional parameters that specify how much memory to display and how to format it; ADDR is an expression giving the address where you want to start displaying memory. If you use defaults for NFU, you need not type the slash `/'. Several commands set convenient defaults for ADDR. N, the repeat count The repeat count is a decimal integer; the default is 1. It specifies how much memory (counting by units U) to display. If a negative number is specified, memory is examined backward from ADDR. F, the display format The display format is one of the formats used by `print' (`x', `d', `u', `o', `t', `a', `c', `f', `s'), `i' (for machine instructions) and `m' (for displaying memory tags). The default is `x' (hexadecimal) initially. The default changes each time you use either `x' or `print'. U, the unit size The unit size is any of `b' Bytes. `h' Halfwords (two bytes). `w' Words (four bytes). This is the initial default. `g' Giant words (eight bytes). Each time you specify a unit size with `x', that size becomes the default unit the next time you use `x'. For the `i' format, the unit size is ignored and is normally not written. For the `s' format, the unit size defaults to `b', unless it is explicitly given. Use `x /hs' to display 16-bit char strings and `x /ws' to display 32-bit strings. The next use of `x /s' will again display 8-bit strings. Note that the results depend on the programming language of the current compilation unit. If the language is C, the `s' modifier will use the UTF-16 encoding while `w' will use UTF-32. The encoding is set by the programming language and cannot be altered. ADDR, starting display address ADDR is the address where you want GDB to begin displaying memory. The expression need not have a pointer value (though it may); it is always interpreted as an integer address of a byte of memory. *Note Expressions: Expressions, for more information on expressions. The default for ADDR is usually just after the last address examined--but several other commands also set the default address: `info breakpoints' (to the address of the last breakpoint listed), `info line' (to the starting address of a line), and `print' (if you use it to display a value from memory). For example, `x/3uh 0x54320' is a request to display three halfwords (`h') of memory, formatted as unsigned decimal integers (`u'), starting at address `0x54320'. `x/4xw $sp' prints the four words (`w') of memory above the stack pointer (here, `$sp'; *note Registers: Registers.) in hexadecimal (`x'). You can also specify a negative repeat count to examine memory backward from the given address. For example, `x/-3uh 0x54320' prints three halfwords (`h') at `0x5431a', `0x5431c', and `0x5431e'. Since the letters indicating unit sizes are all distinct from the letters specifying output formats, you do not have to remember whether unit size or format comes first; either order works. The output specifications `4xw' and `4wx' mean exactly the same thing. (However, the count N must come first; `wx4' does not work.) Even though the unit size U is ignored for the formats `s' and `i', you might still want to use a count N; for example, `3i' specifies that you want to see three machine instructions, including any operands. For convenience, especially when used with the `display' command, the `i' format also prints branch delay slot instructions, if any, beyond the count specified, which immediately follow the last instruction that is within the count. The command `disassemble' gives an alternative way of inspecting machine instructions; see *Note Source and Machine Code: Machine Code. If a negative repeat count is specified for the formats `s' or `i', the command displays null-terminated strings or instructions before the given address as many as the absolute value of the given number. For the `i' format, we use line number information in the debug info to accurately locate instruction boundaries while disassembling backward. If line info is not available, the command stops examining memory with an error message. All the defaults for the arguments to `x' are designed to make it easy to continue scanning memory with minimal specifications each time you use `x'. For example, after you have inspected three machine instructions with `x/3i ADDR', you can inspect the next seven with just `x/7'. If you use to repeat the `x' command, the repeat count N is used again; the other arguments default as for successive uses of `x'. When examining machine instructions, the instruction at current program counter is shown with a `=>' marker. For example: (gdb) x/5i $pc-6 0x804837f : mov %esp,%ebp 0x8048381 : push %ecx 0x8048382 : sub $0x4,%esp => 0x8048385 : movl $0x8048460,(%esp) 0x804838c : call 0x80482d4 If the architecture supports memory tagging, the tags can be displayed by using `m'. *Note Memory Tagging::. The information will be displayed once per granule size (the amount of bytes a particular memory tag covers). For example, AArch64 has a granule size of 16 bytes, so it will display a tag every 16 bytes. Due to the way GDB prints information with the `x' command (not aligned to a particular boundary), the tag information will refer to the initial address displayed on a particular line. If a memory tag boundary is crossed in the middle of a line displayed by the `x' command, it will be displayed on the next line. The `m' format doesn't affect any other specified formats that were passed to the `x' command. The addresses and contents printed by the `x' command are not saved in the value history because there is often too much of them and they would get in the way. Instead, GDB makes these values available for subsequent use in expressions as values of the convenience variables `$_' and `$__'. After an `x' command, the last address examined is available for use in expressions in the convenience variable `$_'. The contents of that address, as examined, are available in the convenience variable `$__'. If the `x' command has a repeat count, the address and contents saved are from the last memory unit printed; this is not the same as the last address printed if several units were printed on the last line of output. Most targets have an addressable memory unit size of 8 bits. This means that to each memory address are associated 8 bits of data. Some targets, however, have other addressable memory unit sizes. Within GDB and this document, the term "addressable memory unit" (or "memory unit" for short) is used when explicitly referring to a chunk of data of that size. The word "byte" is used to refer to a chunk of data of 8 bits, regardless of the addressable memory unit size of the target. For most systems, addressable memory unit is a synonym of byte. When you are debugging a program running on a remote target machine (*note Remote Debugging::), you may wish to verify the program's image in the remote machine's memory against the executable file you downloaded to the target. Or, on any target, you may want to check whether the program has corrupted its own read-only sections. The `compare-sections' command is provided for such situations. `compare-sections [SECTION-NAME|`-r']' Compare the data of a loadable section SECTION-NAME in the executable file of the program being debugged with the same section in the target machine's memory, and report any mismatches. With no arguments, compares all loadable sections. With an argument of `-r', compares all loadable read-only sections. Note: for remote targets, this command can be accelerated if the target supports computing the CRC checksum of a block of memory (*note qCRC packet::).  File: gdb.info, Node: Memory Tagging, Next: Auto Display, Prev: Memory, Up: Data 10.7 Memory Tagging =================== Memory tagging is a memory protection technology that uses a pair of tags to validate memory accesses through pointers. The tags are integer values usually comprised of a few bits, depending on the architecture. There are two types of tags that are used in this setup: logical and allocation. A logical tag is stored in the pointers themselves, usually at the higher bits of the pointers. An allocation tag is the tag associated with particular ranges of memory in the physical address space, against which the logical tags from pointers are compared. The pointer tag (logical tag) must match the memory tag (allocation tag) for the memory access to be valid. If the logical tag does not match the allocation tag, that will raise a memory violation. Allocation tags cover multiple contiguous bytes of physical memory. This range of bytes is called a memory tag granule and is architecture-specific. For example, AArch64 has a tag granule of 16 bytes, meaning each allocation tag spans 16 bytes of memory. If the underlying architecture supports memory tagging, like AArch64 MTE or SPARC ADI do, GDB can make use of it to validate pointers against memory allocation tags. The `print' (*note Data::) and `x' (*note Memory::) commands will display tag information when appropriate, and a command prefix of `memory-tag' gives access to the various memory tagging commands. The `memory-tag' commands are the following: `memory-tag print-logical-tag POINTER_EXPRESSION' Print the logical tag stored in POINTER_EXPRESSION. `memory-tag with-logical-tag POINTER_EXPRESSION TAG_BYTES' Print the pointer given by POINTER_EXPRESSION, augmented with a logical tag of TAG_BYTES. `memory-tag print-allocation-tag ADDRESS_EXPRESSION' Print the allocation tag associated with the memory address given by ADDRESS_EXPRESSION. `memory-tag setatag STARTING_ADDRESS LENGTH TAG_BYTES' Set the allocation tag(s) for memory range [STARTING_ADDRESS, STARTING_ADDRESS + LENGTH) to TAG_BYTES. `memory-tag check POINTER_EXPRESSION' Check if the logical tag in the pointer given by POINTER_EXPRESSION matches the allocation tag for the memory referenced by the pointer. This essentially emulates the hardware validation that is done when tagged memory is accessed through a pointer, but does not cause a memory fault as it would during hardware validation. It can be used to inspect potential memory tagging violations in the running process, before any faults get triggered.  File: gdb.info, Node: Auto Display, Next: Print Settings, Prev: Memory Tagging, Up: Data 10.8 Automatic Display ====================== If you find that you want to print the value of an expression frequently (to see how it changes), you might want to add it to the "automatic display list" so that GDB prints its value each time your program stops. Each expression added to the list is given a number to identify it; to remove an expression from the list, you specify that number. The automatic display looks like this: 2: foo = 38 3: bar[5] = (struct hack *) 0x3804 This display shows item numbers, expressions and their current values. As with displays you request manually using `x' or `print', you can specify the output format you prefer; in fact, `display' decides whether to use `print' or `x' depending your format specification--it uses `x' if you specify either the `i' or `s' format, or a unit size; otherwise it uses `print'. `display EXPR' Add the expression EXPR to the list of expressions to display each time your program stops. *Note Expressions: Expressions. `display' does not repeat if you press again after using it. `display/FMT EXPR' For FMT specifying only a display format and not a size or count, add the expression EXPR to the auto-display list but arrange to display it each time in the specified format FMT. *Note Output Formats: Output Formats. `display/FMT ADDR' For FMT `i' or `s', or including a unit-size or a number of units, add the expression ADDR as a memory address to be examined each time your program stops. Examining means in effect doing `x/FMT ADDR'. *Note Examining Memory: Memory. For example, `display/i $pc' can be helpful, to see the machine instruction about to be executed each time execution stops (`$pc' is a common name for the program counter; *note Registers: Registers.). `undisplay DNUMS...' `delete display DNUMS...' Remove items from the list of expressions to display. Specify the numbers of the displays that you want affected with the command argument DNUMS. It can be a single display number, one of the numbers shown in the first field of the `info display' display; or it could be a range of display numbers, as in `2-4'. `undisplay' does not repeat if you press after using it. (Otherwise you would just get the error `No display number ...'.) `disable display DNUMS...' Disable the display of item numbers DNUMS. A disabled display item is not printed automatically, but is not forgotten. It may be enabled again later. Specify the numbers of the displays that you want affected with the command argument DNUMS. It can be a single display number, one of the numbers shown in the first field of the `info display' display; or it could be a range of display numbers, as in `2-4'. `enable display DNUMS...' Enable display of item numbers DNUMS. It becomes effective once again in auto display of its expression, until you specify otherwise. Specify the numbers of the displays that you want affected with the command argument DNUMS. It can be a single display number, one of the numbers shown in the first field of the `info display' display; or it could be a range of display numbers, as in `2-4'. `display' Display the current values of the expressions on the list, just as is done when your program stops. `info display' Print the list of expressions previously set up to display automatically, each one with its item number, but without showing the values. This includes disabled expressions, which are marked as such. It also includes expressions which would not be displayed right now because they refer to automatic variables not currently available. If a display expression refers to local variables, then it does not make sense outside the lexical context for which it was set up. Such an expression is disabled when execution enters a context where one of its variables is not defined. For example, if you give the command `display last_char' while inside a function with an argument `last_char', GDB displays this argument while your program continues to stop inside that function. When it stops elsewhere--where there is no variable `last_char'--the display is disabled automatically. The next time your program stops where `last_char' is meaningful, you can enable the display expression once again.  File: gdb.info, Node: Print Settings, Next: Pretty Printing, Prev: Auto Display, Up: Data 10.9 Print Settings =================== GDB provides the following ways to control how arrays, structures, and symbols are printed. These settings are useful for debugging programs in any language: `set print address' `set print address on' GDB prints memory addresses showing the location of stack traces, structure values, pointer values, breakpoints, and so forth, even when it also displays the contents of those addresses. The default is `on'. For example, this is what a stack frame display looks like with `set print address on': (gdb) f #0 set_quotes (lq=0x34c78 "<<", rq=0x34c88 ">>") at input.c:530 530 if (lquote != def_lquote) `set print address off' Do not print addresses when displaying their contents. For example, this is the same stack frame displayed with `set print address off': (gdb) set print addr off (gdb) f #0 set_quotes (lq="<<", rq=">>") at input.c:530 530 if (lquote != def_lquote) You can use `set print address off' to eliminate all machine dependent displays from the GDB interface. For example, with `print address off', you should get the same text for backtraces on all machines--whether or not they involve pointer arguments. `show print address' Show whether or not addresses are to be printed. When GDB prints a symbolic address, it normally prints the closest earlier symbol plus an offset. If that symbol does not uniquely identify the address (for example, it is a name whose scope is a single source file), you may need to clarify. One way to do this is with `info line', for example `info line *0x4537'. Alternately, you can set GDB to print the source file and line number when it prints a symbolic address: `set print symbol-filename on' Tell GDB to print the source file name and line number of a symbol in the symbolic form of an address. `set print symbol-filename off' Do not print source file name and line number of a symbol. This is the default. `show print symbol-filename' Show whether or not GDB will print the source file name and line number of a symbol in the symbolic form of an address. Another situation where it is helpful to show symbol filenames and line numbers is when disassembling code; GDB shows you the line number and source file that corresponds to each instruction. Also, you may wish to see the symbolic form only if the address being printed is reasonably close to the closest earlier symbol: `set print max-symbolic-offset MAX-OFFSET' `set print max-symbolic-offset unlimited' Tell GDB to only display the symbolic form of an address if the offset between the closest earlier symbol and the address is less than MAX-OFFSET. The default is `unlimited', which tells GDB to always print the symbolic form of an address if any symbol precedes it. Zero is equivalent to `unlimited'. `show print max-symbolic-offset' Ask how large the maximum offset is that GDB prints in a symbolic address. If you have a pointer and you are not sure where it points, try `set print symbol-filename on'. Then you can determine the name and source file location of the variable where it points, using `p/a POINTER'. This interprets the address in symbolic form. For example, here GDB shows that a variable `ptt' points at another variable `t', defined in `hi2.c': (gdb) set print symbol-filename on (gdb) p/a ptt $4 = 0xe008 _Warning:_ For pointers that point to a local variable, `p/a' does not show the symbol name and filename of the referent, even with the appropriate `set print' options turned on. You can also enable `/a'-like formatting all the time using `set print symbol on': `set print symbol on' Tell GDB to print the symbol corresponding to an address, if one exists. `set print symbol off' Tell GDB not to print the symbol corresponding to an address. In this mode, GDB will still print the symbol corresponding to pointers to functions. This is the default. `show print symbol' Show whether GDB will display the symbol corresponding to an address. Other settings control how different kinds of objects are printed: `set print array' `set print array on' Pretty print arrays. This format is more convenient to read, but uses more space. The default is off. `set print array off' Return to compressed format for arrays. `show print array' Show whether compressed or pretty format is selected for displaying arrays. `set print array-indexes' `set print array-indexes on' Print the index of each element when displaying arrays. May be more convenient to locate a given element in the array or quickly find the index of a given element in that printed array. The default is off. `set print array-indexes off' Stop printing element indexes when displaying arrays. `show print array-indexes' Show whether the index of each element is printed when displaying arrays. `set print nibbles' `set print nibbles on' Print binary values in groups of four bits, known as "nibbles", when using the print command of GDB with the option `/t'. For example, this is what it looks like with `set print nibbles on': (gdb) print val_flags $1 = 1230 (gdb) print/t val_flags $2 = 0100 1100 1110 `set print nibbles off' Don't printing binary values in groups. This is the default. `show print nibbles' Show whether to print binary values in groups of four bits. `set print characters NUMBER-OF-CHARACTERS' `set print characters elements' `set print characters unlimited' Set a limit on how many characters of a string GDB will print. If GDB is printing a large string, it stops printing after it has printed the number of characters set by the `set print characters' command. This equally applies to multi-byte and wide character strings, that is for strings whose character type is `wchar_t', `char16_t', or `char32_t' it is the number of actual characters rather than underlying bytes the encoding uses that this setting controls. Setting NUMBER-OF-CHARACTERS to `elements' means that the limit on the number of characters to print follows one for array elements; see *Note set print elements::. Setting NUMBER-OF-CHARACTERS to `unlimited' means that the number of characters to print is unlimited. When GDB starts, this limit is set to `elements'. `show print characters' Display the number of characters of a large string that GDB will print. `set print elements NUMBER-OF-ELEMENTS' `set print elements unlimited' Set a limit on how many elements of an array GDB will print. If GDB is printing a large array, it stops printing after it has printed the number of elements set by the `set print elements' command. By default this limit also applies to the display of strings; see *Note set print characters::. When GDB starts, this limit is set to 200. Setting NUMBER-OF-ELEMENTS to `unlimited' or zero means that the number of elements to print is unlimited. When printing very large arrays, whose size is greater than `max-value-size' (*note max-value-size: set max-value-size.), if the `print elements' is set such that the size of the elements being printed is less than or equal to `max-value-size', then GDB will print the array (up to the `print elements' limit), and only `max-value-size' worth of data will be added into the value history (*note Value History: Value History.). `show print elements' Display the number of elements of a large array that GDB will print. `set print frame-arguments VALUE' This command allows to control how the values of arguments are printed when the debugger prints a frame (*note Frames::). The possible values are: `all' The values of all arguments are printed. `scalars' Print the value of an argument only if it is a scalar. The value of more complex arguments such as arrays, structures, unions, etc, is replaced by `...'. This is the default. Here is an example where only scalar arguments are shown: #1 0x08048361 in call_me (i=3, s=..., ss=0xbf8d508c, u=..., e=green) at frame-args.c:23 `none' None of the argument values are printed. Instead, the value of each argument is replaced by `...'. In this case, the example above now becomes: #1 0x08048361 in call_me (i=..., s=..., ss=..., u=..., e=...) at frame-args.c:23 `presence' Only the presence of arguments is indicated by `...'. The `...' are not printed for function without any arguments. None of the argument names and values are printed. In this case, the example above now becomes: #1 0x08048361 in call_me (...) at frame-args.c:23 By default, only scalar arguments are printed. This command can be used to configure the debugger to print the value of all arguments, regardless of their type. However, it is often advantageous to not print the value of more complex parameters. For instance, it reduces the amount of information printed in each frame, making the backtrace more readable. Also, it improves performance when displaying Ada frames, because the computation of large arguments can sometimes be CPU-intensive, especially in large applications. Setting `print frame-arguments' to `scalars' (the default), `none' or `presence' avoids this computation, thus speeding up the display of each Ada frame. `show print frame-arguments' Show how the value of arguments should be displayed when printing a frame. `set print raw-frame-arguments on' Print frame arguments in raw, non pretty-printed, form. `set print raw-frame-arguments off' Print frame arguments in pretty-printed form, if there is a pretty-printer for the value (*note Pretty Printing::), otherwise print the value in raw form. This is the default. `show print raw-frame-arguments' Show whether to print frame arguments in raw form. `set print entry-values VALUE' Set printing of frame argument values at function entry. In some cases GDB can determine the value of function argument which was passed by the function caller, even if the value was modified inside the called function and therefore is different. With optimized code, the current value could be unavailable, but the entry value may still be known. The default value is `default' (see below for its description). Older GDB behaved as with the setting `no'. Compilers not supporting this feature will behave in the `default' setting the same way as with the `no' setting. This functionality is currently supported only by DWARF 2 debugging format and the compiler has to produce `DW_TAG_call_site' tags. With GCC, you need to specify `-O -g' during compilation, to get this information. The VALUE parameter can be one of the following: `no' Print only actual parameter values, never print values from function entry point. #0 equal (val=5) #0 different (val=6) #0 lost (val=) #0 born (val=10) #0 invalid (val=) `only' Print only parameter values from function entry point. The actual parameter values are never printed. #0 equal (val@@entry=5) #0 different (val@@entry=5) #0 lost (val@@entry=5) #0 born (val@@entry=) #0 invalid (val@@entry=) `preferred' Print only parameter values from function entry point. If value from function entry point is not known while the actual value is known, print the actual value for such parameter. #0 equal (val@@entry=5) #0 different (val@@entry=5) #0 lost (val@@entry=5) #0 born (val=10) #0 invalid (val@@entry=) `if-needed' Print actual parameter values. If actual parameter value is not known while value from function entry point is known, print the entry point value for such parameter. #0 equal (val=5) #0 different (val=6) #0 lost (val@@entry=5) #0 born (val=10) #0 invalid (val=) `both' Always print both the actual parameter value and its value from function entry point, even if values of one or both are not available due to compiler optimizations. #0 equal (val=5, val@@entry=5) #0 different (val=6, val@@entry=5) #0 lost (val=, val@@entry=5) #0 born (val=10, val@@entry=) #0 invalid (val=, val@@entry=) `compact' Print the actual parameter value if it is known and also its value from function entry point if it is known. If neither is known, print for the actual value `'. If not in MI mode (*note GDB/MI::) and if both values are known and identical, print the shortened `param=param@@entry=VALUE' notation. #0 equal (val=val@@entry=5) #0 different (val=6, val@@entry=5) #0 lost (val@@entry=5) #0 born (val=10) #0 invalid (val=) `default' Always print the actual parameter value. Print also its value from function entry point, but only if it is known. If not in MI mode (*note GDB/MI::) and if both values are known and identical, print the shortened `param=param@@entry=VALUE' notation. #0 equal (val=val@@entry=5) #0 different (val=6, val@@entry=5) #0 lost (val=, val@@entry=5) #0 born (val=10) #0 invalid (val=) For analysis messages on possible failures of frame argument values at function entry resolution see *Note set debug entry-values::. `show print entry-values' Show the method being used for printing of frame argument values at function entry. `set print frame-info VALUE' This command allows to control the information printed when the debugger prints a frame. See *Note Frames::, *Note Backtrace::, for a general explanation about frames and frame information. Note that some other settings (such as `set print frame-arguments' and `set print address') are also influencing if and how some frame information is displayed. In particular, the frame program counter is never printed if `set print address' is off. The possible values for `set print frame-info' are: `short-location' Print the frame level, the program counter (if not at the beginning of the location source line), the function, the function arguments. `location' Same as `short-location' but also print the source file and source line number. `location-and-address' Same as `location' but print the program counter even if located at the beginning of the location source line. `source-line' Print the program counter (if not at the beginning of the location source line), the line number and the source line. `source-and-location' Print what `location' and `source-line' are printing. `auto' The information printed for a frame is decided automatically by the GDB command that prints a frame. For example, `frame' prints the information printed by `source-and-location' while `stepi' will switch between `source-line' and `source-and-location' depending on the program counter. The default value is `auto'. `set print repeats NUMBER-OF-REPEATS' `set print repeats unlimited' Set the threshold for suppressing display of repeated array elements. When the number of consecutive identical elements of an array exceeds the threshold, GDB prints the string `""', where N is the number of identical repetitions, instead of displaying the identical elements themselves. Setting the threshold to `unlimited' or zero will cause all elements to be individually printed. The default threshold is 10. `show print repeats' Display the current threshold for printing repeated identical elements. `set print max-depth DEPTH' `set print max-depth unlimited' Set the threshold after which nested structures are replaced with ellipsis, this can make visualising deeply nested structures easier. For example, given this C code typedef struct s1 { int a; } s1; typedef struct s2 { s1 b; } s2; typedef struct s3 { s2 c; } s3; typedef struct s4 { s3 d; } s4; s4 var = { { { { 3 } } } }; The following table shows how different values of DEPTH will effect how `var' is printed by GDB: DEPTH setting Result of `p var' --------------------------------------------------------------------- unlimited `$1 = {d = {c = {b = {a = 3}}}}' `0' `$1 = {...}' `1' `$1 = {d = {...}}' `2' `$1 = {d = {c = {...}}}' `3' `$1 = {d = {c = {b = {...}}}}' `4' `$1 = {d = {c = {b = {a = 3}}}}' To see the contents of structures that have been hidden the user can either increase the print max-depth, or they can print the elements of the structure that are visible, for example (gdb) set print max-depth 2 (gdb) p var $1 = {d = {c = {...}}} (gdb) p var.d $2 = {c = {b = {...}}} (gdb) p var.d.c $3 = {b = {a = 3}} The pattern used to replace nested structures varies based on language, for most languages `{...}' is used, but Fortran uses `(...)'. `show print max-depth' Display the current threshold after which nested structures are replaces with ellipsis. `set print memory-tag-violations' `set print memory-tag-violations on' Cause GDB to display additional information about memory tag violations when printing pointers and addresses. `set print memory-tag-violations off' Stop printing memory tag violation information. `show print memory-tag-violations' Show whether memory tag violation information is displayed when printing pointers and addresses. `set print null-stop' Cause GDB to stop printing the characters of an array when the first NULL is encountered. This is useful when large arrays actually contain only short strings. The default is off. `show print null-stop' Show whether GDB stops printing an array on the first NULL character. `set print pretty on' Cause GDB to print structures in an indented format with one member per line, like this: $1 = { next = 0x0, flags = { sweet = 1, sour = 1 }, meat = 0x54 "Pork" } `set print pretty off' Cause GDB to print structures in a compact format, like this: $1 = {next = 0x0, flags = {sweet = 1, sour = 1}, \ meat = 0x54 "Pork"} This is the default format. `show print pretty' Show which format GDB is using to print structures. `set print raw-values on' Print values in raw form, without applying the pretty printers for the value. `set print raw-values off' Print values in pretty-printed form, if there is a pretty-printer for the value (*note Pretty Printing::), otherwise print the value in raw form. The default setting is "off". `show print raw-values' Show whether to print values in raw form. `set print sevenbit-strings on' Print using only seven-bit characters; if this option is set, GDB displays any eight-bit characters (in strings or character values) using the notation `\'NNN. This setting is best if you are working in English (ASCII) and you use the high-order bit of characters as a marker or "meta" bit. `set print sevenbit-strings off' Print full eight-bit characters. This allows the use of more international character sets, and is the default. `show print sevenbit-strings' Show whether or not GDB is printing only seven-bit characters. `set print union on' Tell GDB to print unions which are contained in structures and other unions. This is the default setting. `set print union off' Tell GDB not to print unions which are contained in structures and other unions. GDB will print `"{...}"' instead. `show print union' Ask GDB whether or not it will print unions which are contained in structures and other unions. For example, given the declarations typedef enum {Tree, Bug} Species; typedef enum {Big_tree, Acorn, Seedling} Tree_forms; typedef enum {Caterpillar, Cocoon, Butterfly} Bug_forms; struct thing { Species it; union { Tree_forms tree; Bug_forms bug; } form; }; struct thing foo = {Tree, {Acorn}}; with `set print union on' in effect `p foo' would print $1 = {it = Tree, form = {tree = Acorn, bug = Cocoon}} and with `set print union off' in effect it would print $1 = {it = Tree, form = {...}} `set print union' affects programs written in C-like languages and in Pascal. These settings are of interest when debugging C++ programs: `set print demangle' `set print demangle on' Print C++ names in their source form rather than in the encoded ("mangled") form passed to the assembler and linker for type-safe linkage. The default is on. `show print demangle' Show whether C++ names are printed in mangled or demangled form. `set print asm-demangle' `set print asm-demangle on' Print C++ names in their source form rather than their mangled form, even in assembler code printouts such as instruction disassemblies. The default is off. `show print asm-demangle' Show whether C++ names in assembly listings are printed in mangled or demangled form. `set demangle-style STYLE' Choose among several encoding schemes used by different compilers to represent C++ names. If you omit STYLE, you will see a list of possible formats. The default value is AUTO, which lets GDB choose a decoding style by inspecting your program. `show demangle-style' Display the encoding style currently in use for decoding C++ symbols. `set print object' `set print object on' When displaying a pointer to an object, identify the _actual_ (derived) type of the object rather than the _declared_ type, using the virtual function table. Note that the virtual function table is required--this feature can only work for objects that have run-time type identification; a single virtual method in the object's declared type is sufficient. Note that this setting is also taken into account when working with variable objects via MI (*note GDB/MI::). `set print object off' Display only the declared type of objects, without reference to the virtual function table. This is the default setting. `show print object' Show whether actual, or declared, object types are displayed. `set print static-members' `set print static-members on' Print static members when displaying a C++ object. The default is on. `set print static-members off' Do not print static members when displaying a C++ object. `show print static-members' Show whether C++ static members are printed or not. `set print pascal_static-members' `set print pascal_static-members on' Print static members when displaying a Pascal object. The default is on. `set print pascal_static-members off' Do not print static members when displaying a Pascal object. `show print pascal_static-members' Show whether Pascal static members are printed or not. `set print vtbl' `set print vtbl on' Pretty print C++ virtual function tables. The default is off. (The `vtbl' commands do not work on programs compiled with the HP ANSI C++ compiler (`aCC').) `set print vtbl off' Do not pretty print C++ virtual function tables. `show print vtbl' Show whether C++ virtual function tables are pretty printed, or not.  File: gdb.info, Node: Pretty Printing, Next: Value History, Prev: Print Settings, Up: Data 10.10 Pretty Printing ===================== GDB provides a mechanism to allow pretty-printing of values using Python code. It greatly simplifies the display of complex objects. This mechanism works for both MI and the CLI. * Menu: * Pretty-Printer Introduction:: Introduction to pretty-printers * Pretty-Printer Example:: An example pretty-printer * Pretty-Printer Commands:: Pretty-printer commands  File: gdb.info, Node: Pretty-Printer Introduction, Next: Pretty-Printer Example, Up: Pretty Printing 10.10.1 Pretty-Printer Introduction ----------------------------------- When GDB prints a value, it first sees if there is a pretty-printer registered for the value. If there is then GDB invokes the pretty-printer to print the value. Otherwise the value is printed normally. Pretty-printers are normally named. This makes them easy to manage. The `info pretty-printer' command will list all the installed pretty-printers with their names. If a pretty-printer can handle multiple data types, then its "subprinters" are the printers for the individual data types. Each such subprinter has its own name. The format of the name is PRINTER-NAME;SUBPRINTER-NAME. Pretty-printers are installed by "registering" them with GDB. Typically they are automatically loaded and registered when the corresponding debug information is loaded, thus making them available without having to do anything special. There are three places where a pretty-printer can be registered. * Pretty-printers registered globally are available when debugging all inferiors. * Pretty-printers registered with a program space are available only when debugging that program. *Note Progspaces In Python::, for more details on program spaces in Python. * Pretty-printers registered with an objfile are loaded and unloaded with the corresponding objfile (e.g., shared library). *Note Objfiles In Python::, for more details on objfiles in Python. *Note Selecting Pretty-Printers::, for further information on how pretty-printers are selected, *Note Writing a Pretty-Printer::, for implementing pretty printers for new types.  File: gdb.info, Node: Pretty-Printer Example, Next: Pretty-Printer Commands, Prev: Pretty-Printer Introduction, Up: Pretty Printing 10.10.2 Pretty-Printer Example ------------------------------ Here is how a C++ `std::string' looks without a pretty-printer: (gdb) print s $1 = { static npos = 4294967295, _M_dataplus = { > = { <__gnu_cxx::new_allocator> = { }, }, members of std::basic_string, std::allocator >::_Alloc_hider: _M_p = 0x804a014 "abcd" } } With a pretty-printer for `std::string' only the contents are printed: (gdb) print s $2 = "abcd"  File: gdb.info, Node: Pretty-Printer Commands, Prev: Pretty-Printer Example, Up: Pretty Printing 10.10.3 Pretty-Printer Commands ------------------------------- `info pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]' Print the list of installed pretty-printers. This includes disabled pretty-printers, which are marked as such. OBJECT-REGEXP is a regular expression matching the objects whose pretty-printers to list. Objects can be `global', the program space's file (*note Progspaces In Python::), and the object files within that program space (*note Objfiles In Python::). *Note Selecting Pretty-Printers::, for details on how GDB looks up a printer from these three objects. NAME-REGEXP is a regular expression matching the name of the printers to list. `disable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]' Disable pretty-printers matching OBJECT-REGEXP and NAME-REGEXP. A disabled pretty-printer is not forgotten, it may be enabled again later. `enable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]' Enable pretty-printers matching OBJECT-REGEXP and NAME-REGEXP. Example: Suppose we have three pretty-printers installed: one from library1.so named `foo' that prints objects of type `foo', and another from library2.so named `bar' that prints two types of objects, `bar1' and `bar2'. (gdb) info pretty-printer library1.so: foo library2.so: bar bar1 bar2 (gdb) info pretty-printer library2 library2.so: bar bar1 bar2 (gdb) disable pretty-printer library1 1 printer disabled 2 of 3 printers enabled (gdb) info pretty-printer library1.so: foo [disabled] library2.so: bar bar1 bar2 (gdb) disable pretty-printer library2 bar;bar1 1 printer disabled 1 of 3 printers enabled (gdb) info pretty-printer library2 library2.so: bar bar1 [disabled] bar2 (gdb) disable pretty-printer library2 bar 1 printer disabled 0 of 3 printers enabled (gdb) info pretty-printer library1.so: foo [disabled] library2.so: bar [disabled] bar1 [disabled] bar2 Note that for `bar' the entire printer can be disabled, as can each individual subprinter. Printing values and frame arguments is done by default using the enabled pretty printers. The print option `-raw-values' and GDB setting `set print raw-values' (*note set print raw-values::) can be used to print values without applying the enabled pretty printers. Similarly, the backtrace option `-raw-frame-arguments' and GDB setting `set print raw-frame-arguments' (*note set print raw-frame-arguments::) can be used to ignore the enabled pretty printers when printing frame argument values.  File: gdb.info, Node: Value History, Next: Convenience Vars, Prev: Pretty Printing, Up: Data 10.11 Value History =================== Values printed by the `print' command are saved in the GDB "value history". This allows you to refer to them in other expressions. Values are kept until the symbol table is re-read or discarded (for example with the `file' or `symbol-file' commands). When the symbol table changes, the value history is discarded, since the values may contain pointers back to the types defined in the symbol table. The values printed are given "history numbers" by which you can refer to them. These are successive integers starting with one. `print' shows you the history number assigned to a value by printing `$NUM = ' before the value; here NUM is the history number. To refer to any previous value, use `$' followed by the value's history number. The way `print' labels its output is designed to remind you of this. Just `$' refers to the most recent value in the history, and `$$' refers to the value before that. `$$N' refers to the Nth value from the end; `$$2' is the value just prior to `$$', `$$1' is equivalent to `$$', and `$$0' is equivalent to `$'. For example, suppose you have just printed a pointer to a structure and want to see the contents of the structure. It suffices to type p *$ If you have a chain of structures where the component `next' points to the next one, you can print the contents of the next one with this: p *$.next You can print successive links in the chain by repeating this command--which you can do by just typing . Note that the history records values, not expressions. If the value of `x' is 4 and you type these commands: print x set x=5 then the value recorded in the value history by the `print' command remains 4 even though the value of `x' has changed. `show values' Print the last ten values in the value history, with their item numbers. This is like `p $$9' repeated ten times, except that `show values' does not change the history. `show values N' Print ten history values centered on history item number N. `show values +' Print ten history values just after the values last printed. If no more values are available, `show values +' produces no display. Pressing to repeat `show values N' has exactly the same effect as `show values +'.  File: gdb.info, Node: Convenience Vars, Next: Convenience Funs, Prev: Value History, Up: Data 10.12 Convenience Variables =========================== GDB provides "convenience variables" that you can use within GDB to hold on to a value and refer to it later. These variables exist entirely within GDB; they are not part of your program, and setting a convenience variable has no direct effect on further execution of your program. That is why you can use them freely. Convenience variables are prefixed with `$'. Any name preceded by `$' can be used for a convenience variable, unless it is one of the predefined machine-specific register names (*note Registers: Registers.). (Value history references, in contrast, are _numbers_ preceded by `$'. *Note Value History: Value History.) You can save a value in a convenience variable with an assignment expression, just as you would set a variable in your program. For example: set $foo = *object_ptr would save in `$foo' the value contained in the object pointed to by `object_ptr'. Using a convenience variable for the first time creates it, but its value is `void' until you assign a new value. You can alter the value with another assignment at any time. Convenience variables have no fixed types. You can assign a convenience variable any type of value, including structures and arrays, even if that variable already has a value of a different type. The convenience variable, when used as an expression, has the type of its current value. `show convenience' Print a list of convenience variables used so far, and their values, as well as a list of the convenience functions. Abbreviated `show conv'. `init-if-undefined $VARIABLE = EXPRESSION' Set a convenience variable if it has not already been set. This is useful for user-defined commands that keep some state. It is similar, in concept, to using local static variables with initializers in C (except that convenience variables are global). It can also be used to allow users to override default values used in a command script. If the variable is already defined then the expression is not evaluated so any side-effects do not occur. One of the ways to use a convenience variable is as a counter to be incremented or a pointer to be advanced. For example, to print a field from successive elements of an array of structures: set $i = 0 print bar[$i++]->contents Repeat that command by typing . Some convenience variables are created automatically by GDB and given values likely to be useful. `$_' The variable `$_' is automatically set by the `x' command to the last address examined (*note Examining Memory: Memory.). Other commands which provide a default address for `x' to examine also set `$_' to that address; these commands include `info line' and `info breakpoint'. The type of `$_' is `void *' except when set by the `x' command, in which case it is a pointer to the type of `$__'. `$__' The variable `$__' is automatically set by the `x' command to the value found in the last address examined. Its type is chosen to match the format in which the data was printed. `$_exitcode' When the program being debugged terminates normally, GDB automatically sets this variable to the exit code of the program, and resets `$_exitsignal' to `void'. `$_exitsignal' When the program being debugged dies due to an uncaught signal, GDB automatically sets this variable to that signal's number, and resets `$_exitcode' to `void'. To distinguish between whether the program being debugged has exited (i.e., `$_exitcode' is not `void') or signalled (i.e., `$_exitsignal' is not `void'), the convenience function `$_isvoid' can be used (*note Convenience Functions: Convenience Funs.). For example, considering the following source code: #include int main (int argc, char *argv[]) { raise (SIGALRM); return 0; } A valid way of telling whether the program being debugged has exited or signalled would be: (gdb) define has_exited_or_signalled Type commands for definition of ``has_exited_or_signalled''. End with a line saying just ``end''. >if $_isvoid ($_exitsignal) >echo The program has exited\n >else >echo The program has signalled\n >end >end (gdb) run Starting program: Program terminated with signal SIGALRM, Alarm clock. The program no longer exists. (gdb) has_exited_or_signalled The program has signalled As can be seen, GDB correctly informs that the program being debugged has signalled, since it calls `raise' and raises a `SIGALRM' signal. If the program being debugged had not called `raise', then GDB would report a normal exit: (gdb) has_exited_or_signalled The program has exited `$_exception' The variable `$_exception' is set to the exception object being thrown at an exception-related catchpoint. *Note Set Catchpoints::. `$_ada_exception' The variable `$_ada_exception' is set to the address of the exception being caught or thrown at an Ada exception-related catchpoint. *Note Set Catchpoints::. `$_probe_argc' `$_probe_arg0...$_probe_arg11' Arguments to a static probe. *Note Static Probe Points::. `$_sdata' The variable `$_sdata' contains extra collected static tracepoint data. *Note Tracepoint Action Lists: Tracepoint Actions. Note that `$_sdata' could be empty, if not inspecting a trace buffer, or if extra static tracepoint data has not been collected. `$_siginfo' The variable `$_siginfo' contains extra signal information (*note extra signal information::). Note that `$_siginfo' could be empty, if the application has not yet received any signals. For example, it will be empty before you execute the `run' command. `$_tlb' The variable `$_tlb' is automatically set when debugging applications running on MS-Windows in native mode or connected to gdbserver that supports the `qGetTIBAddr' request. *Note General Query Packets::. This variable contains the address of the thread information block. `$_inferior' The number of the current inferior. *Note Debugging Multiple Inferiors Connections and Programs: Inferiors Connections and Programs. `$_thread' The thread number of the current thread. *Note thread numbers::. `$_gthread' The global number of the current thread. *Note global thread numbers::. `$_inferior_thread_count' The number of live threads in the current inferior. *Note Threads::. `$_gdb_major' `$_gdb_minor' The major and minor version numbers of the running GDB. Development snapshots and pretest versions have their minor version incremented by one; thus, GDB pretest 9.11.90 will produce the value 12 for `$_gdb_minor'. These variables allow you to write scripts that work with different versions of GDB without errors caused by features unavailable in some of those versions. `$_shell_exitcode' `$_shell_exitsignal' GDB commands such as `shell' and `|' are launching shell commands. When a launched command terminates, GDB automatically maintains the variables `$_shell_exitcode' and `$_shell_exitsignal' according to the exit status of the last launched command. These variables are set and used similarly to the variables `$_exitcode' and `$_exitsignal'.  File: gdb.info, Node: Convenience Funs, Next: Registers, Prev: Convenience Vars, Up: Data 10.13 Convenience Functions =========================== GDB also supplies some "convenience functions". These have a syntax similar to convenience variables. A convenience function can be used in an expression just like an ordinary function; however, a convenience function is implemented internally to GDB. These functions do not require GDB to be configured with `Python' support, which means that they are always available. `$_isvoid (EXPR)' Return one if the expression EXPR is `void'. Otherwise it returns zero. A `void' expression is an expression where the type of the result is `void'. For example, you can examine a convenience variable (see *Note Convenience Variables: Convenience Vars.) to check whether it is `void': (gdb) print $_exitcode $1 = void (gdb) print $_isvoid ($_exitcode) $2 = 1 (gdb) run Starting program: ./a.out [Inferior 1 (process 29572) exited normally] (gdb) print $_exitcode $3 = 0 (gdb) print $_isvoid ($_exitcode) $4 = 0 In the example above, we used `$_isvoid' to check whether `$_exitcode' is `void' before and after the execution of the program being debugged. Before the execution there is no exit code to be examined, therefore `$_exitcode' is `void'. After the execution the program being debugged returned zero, therefore `$_exitcode' is zero, which means that it is not `void' anymore. The `void' expression can also be a call of a function from the program being debugged. For example, given the following function: void foo (void) { } The result of calling it inside GDB is `void': (gdb) print foo () $1 = void (gdb) print $_isvoid (foo ()) $2 = 1 (gdb) set $v = foo () (gdb) print $v $3 = void (gdb) print $_isvoid ($v) $4 = 1 `$_gdb_setting_str (SETTING)' Return the value of the GDB SETTING as a string. SETTING is any setting that can be used in a `set' or `show' command (*note Controlling GDB::). (gdb) show print frame-arguments Printing of non-scalar frame arguments is "scalars". (gdb) p $_gdb_setting_str("print frame-arguments") $1 = "scalars" (gdb) p $_gdb_setting_str("height") $2 = "30" (gdb) `$_gdb_setting (SETTING)' Return the value of the GDB SETTING. The type of the returned value depends on the setting. The value type for boolean and auto boolean settings is `int'. The boolean values `off' and `on' are converted to the integer values `0' and `1'. The value `auto' is converted to the value `-1'. The value type for integer settings is either `unsigned int' or `int', depending on the setting. Some integer settings accept an `unlimited' value. Depending on the setting, the `set' command also accepts the value `0' or the value `-1' as a synonym for `unlimited'. For example, `set height unlimited' is equivalent to `set height 0'. Some other settings that accept the `unlimited' value use the value `0' to literally mean zero. For example, `set history size 0' indicates to not record any GDB commands in the command history. For such settings, `-1' is the synonym for `unlimited'. See the documentation of the corresponding `set' command for the numerical value equivalent to `unlimited'. The `$_gdb_setting' function converts the unlimited value to a `0' or a `-1' value according to what the `set' command uses. (gdb) p $_gdb_setting_str("height") $1 = "30" (gdb) p $_gdb_setting("height") $2 = 30 (gdb) set height unlimited (gdb) p $_gdb_setting_str("height") $3 = "unlimited" (gdb) p $_gdb_setting("height") $4 = 0 (gdb) p $_gdb_setting_str("history size") $5 = "unlimited" (gdb) p $_gdb_setting("history size") $6 = -1 (gdb) p $_gdb_setting_str("disassemble-next-line") $7 = "auto" (gdb) p $_gdb_setting("disassemble-next-line") $8 = -1 (gdb) Other setting types (enum, filename, optional filename, string, string noescape) are returned as string values. `$_gdb_maint_setting_str (SETTING)' Like the `$_gdb_setting_str' function, but works with `maintenance set' variables. `$_gdb_maint_setting (SETTING)' Like the `$_gdb_setting' function, but works with `maintenance set' variables. `$_shell (COMMAND-STRING)' Invoke a shell to execute COMMAND-STRING. COMMAND-STRING must be a string. The shell runs on the host machine, the machine GDB is running on. Returns the command's exit status. On Unix systems, a command which exits with a zero exit status has succeeded, and non-zero exit status indicates failure. When a command terminates on a fatal signal whose number is N, GDB uses the value 128+N as the exit status, as is standard in Unix shells. Note that N is a host signal number, not a target signal number. If you're native debugging, they will be the same, but if cross debugging, the host vs target signal numbers may be completely unrelated. Please consult your host operating system's documentation for the mapping between host signal numbers and signal names. The shell to run is determined in the same way as for the `shell' command. *Note Shell Commands: Shell Commands. (gdb) print $_shell("true") $1 = 0 (gdb) print $_shell("false") $2 = 1 (gdb) p $_shell("echo hello") hello $3 = 0 (gdb) p $_shell("foobar") bash: line 1: foobar: command not found $4 = 127 This may also be useful in breakpoint conditions. For example: (gdb) break function if $_shell("some command") == 0 In this scenario, you'll want to make sure that the shell command you run in the breakpoint condition takes the least amount of time possible. For example, avoid running a command that may block indefinitely, or that sleeps for a while before exiting. Prefer a command or script which analyzes some state and exits immediately. This is important because the debugged program stops for the breakpoint every time, and then GDB evaluates the breakpoint condition. If the condition is false, the program is re-resumed transparently, without informing you of the stop. A quick shell command thus avoids significantly slowing down the debugged program unnecessarily. Note: unlike the `shell' command, the `$_shell' convenience function does not affect the `$_shell_exitcode' and `$_shell_exitsignal' convenience variables. The following functions require GDB to be configured with `Python' support. `$_memeq(BUF1, BUF2, LENGTH)' Returns one if the LENGTH bytes at the addresses given by BUF1 and BUF2 are equal. Otherwise it returns zero. `$_regex(STR, REGEX)' Returns one if the string STR matches the regular expression REGEX. Otherwise it returns zero. The syntax of the regular expression is that specified by `Python''s regular expression support. `$_streq(STR1, STR2)' Returns one if the strings STR1 and STR2 are equal. Otherwise it returns zero. `$_strlen(STR)' Returns the length of string STR. `$_caller_is(NAME[, NUMBER_OF_FRAMES])' Returns one if the calling function's name is equal to NAME. Otherwise it returns zero. If the optional argument NUMBER_OF_FRAMES is provided, it is the number of frames up in the stack to look. The default is 1. Example: (gdb) backtrace #0 bottom_func () at testsuite/gdb.python/py-caller-is.c:21 #1 0x00000000004005a0 in middle_func () at testsuite/gdb.python/py-caller-is.c:27 #2 0x00000000004005ab in top_func () at testsuite/gdb.python/py-caller-is.c:33 #3 0x00000000004005b6 in main () at testsuite/gdb.python/py-caller-is.c:39 (gdb) print $_caller_is ("middle_func") $1 = 1 (gdb) print $_caller_is ("top_func", 2) $1 = 1 `$_caller_matches(REGEXP[, NUMBER_OF_FRAMES])' Returns one if the calling function's name matches the regular expression REGEXP. Otherwise it returns zero. If the optional argument NUMBER_OF_FRAMES is provided, it is the number of frames up in the stack to look. The default is 1. `$_any_caller_is(NAME[, NUMBER_OF_FRAMES])' Returns one if any calling function's name is equal to NAME. Otherwise it returns zero. If the optional argument NUMBER_OF_FRAMES is provided, it is the number of frames up in the stack to look. The default is 1. This function differs from `$_caller_is' in that this function checks all stack frames from the immediate caller to the frame specified by NUMBER_OF_FRAMES, whereas `$_caller_is' only checks the frame specified by NUMBER_OF_FRAMES. `$_any_caller_matches(REGEXP[, NUMBER_OF_FRAMES])' Returns one if any calling function's name matches the regular expression REGEXP. Otherwise it returns zero. If the optional argument NUMBER_OF_FRAMES is provided, it is the number of frames up in the stack to look. The default is 1. This function differs from `$_caller_matches' in that this function checks all stack frames from the immediate caller to the frame specified by NUMBER_OF_FRAMES, whereas `$_caller_matches' only checks the frame specified by NUMBER_OF_FRAMES. `$_as_string(VALUE)' This convenience function is considered deprecated, and could be removed from future versions of GDB. Use the `%V' format specifier instead (*note %V Format Specifier::). Return the string representation of VALUE. This function is useful to obtain the textual label (enumerator) of an enumeration value. For example, assuming the variable NODE is of an enumerated type: (gdb) printf "Visiting node of type %s\n", $_as_string(node) Visiting node of type NODE_INTEGER `$_cimag(VALUE)' `$_creal(VALUE)' Return the imaginary (`$_cimag') or real (`$_creal') part of the complex number VALUE. The type of the imaginary or real part depends on the type of the complex number, e.g., using `$_cimag' on a `float complex' will return an imaginary part of type `float'. GDB provides the ability to list and get help on convenience functions. `help function' Print a list of all convenience functions.  File: gdb.info, Node: Registers, Next: Floating Point Hardware, Prev: Convenience Funs, Up: Data 10.14 Registers =============== You can refer to machine register contents, in expressions, as variables with names starting with `$'. The names of registers are different for each machine; use `info registers' to see the names used on your machine. `info registers' Print the names and values of all registers except floating-point and vector registers (in the selected stack frame). `info all-registers' Print the names and values of all registers, including floating-point and vector registers (in the selected stack frame). `info registers REGGROUP ...' Print the name and value of the registers in each of the specified REGGROUPs. The REGGROUP can be any of those returned by `maint print reggroups' (*note Maintenance Commands::). `info registers REGNAME ...' Print the "relativized" value of each specified register REGNAME. As discussed in detail below, register values are normally relative to the selected stack frame. The REGNAME may be any register name valid on the machine you are using, with or without the initial `$'. GDB has four "standard" register names that are available (in expressions) on most machines--whenever they do not conflict with an architecture's canonical mnemonics for registers. The register names `$pc' and `$sp' are used for the program counter register and the stack pointer. `$fp' is used for a register that contains a pointer to the current stack frame, and `$ps' is used for a register that contains the processor status. For example, you could print the program counter in hex with p/x $pc or print the instruction to be executed next with x/i $pc or add four to the stack pointer(1) with set $sp += 4 Whenever possible, these four standard register names are available on your machine even though the machine has different canonical mnemonics, so long as there is no conflict. The `info registers' command shows the canonical names. For example, on the SPARC, `info registers' displays the processor status register as `$psr' but you can also refer to it as `$ps'; and on x86-based machines `$ps' is an alias for the EFLAGS register. GDB always considers the contents of an ordinary register as an integer when the register is examined in this way. Some machines have special registers which can hold nothing but floating point; these registers are considered to have floating point values. There is no way to refer to the contents of an ordinary register as floating point value (although you can _print_ it as a floating point value with `print/f $REGNAME'). Some registers have distinct "raw" and "virtual" data formats. This means that the data format in which the register contents are saved by the operating system is not the same one that your program normally sees. For example, the registers of the 68881 floating point coprocessor are always saved in "extended" (raw) format, but all C programs expect to work with "double" (virtual) format. In such cases, GDB normally works with the virtual format only (the format that makes sense for your program), but the `info registers' command prints the data in both formats. Some machines have special registers whose contents can be interpreted in several different ways. For example, modern x86-based machines have SSE and MMX registers that can hold several values packed together in several different formats. GDB refers to such registers in `struct' notation: (gdb) print $xmm1 $1 = { v4_float = {0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044}, v2_double = {9.92129282474342e-303, 2.7585945287983262e-313}, v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000", v8_int16 = {0, 0, 14072, 315, 11, 0, 13, 0}, v4_int32 = {0, 20657912, 11, 13}, v2_int64 = {88725056443645952, 55834574859}, uint128 = 0x0000000d0000000b013b36f800000000 } To set values of such registers, you need to tell GDB which view of the register you wish to change, as if you were assigning value to a `struct' member: (gdb) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF Normally, register values are relative to the selected stack frame (*note Selecting a Frame: Selection.). This means that you get the value that the register would contain if all stack frames farther in were exited and their saved registers restored. In order to see the true contents of hardware registers, you must select the innermost frame (with `frame 0'). Usually ABIs reserve some registers as not needed to be saved by the callee (a.k.a.: "caller-saved", "call-clobbered" or "volatile" registers). It may therefore not be possible for GDB to know the value a register had before the call (in other words, in the outer frame), if the register value has since been changed by the callee. GDB tries to deduce where the inner frame saved ("callee-saved") registers, from the debug info, unwind info, or the machine code generated by your compiler. If some register is not saved, and GDB knows the register is "caller-saved" (via its own knowledge of the ABI, or because the debug/unwind info explicitly says the register's value is undefined), GDB displays `' as the register's value. With targets that GDB has no knowledge of the register saving convention, if a register was not saved by the callee, then its value and location in the outer frame are assumed to be the same of the inner frame. This is usually harmless, because if the register is call-clobbered, the caller either does not care what is in the register after the call, or has code to restore the value that it does care about. Note, however, that if you change such a register in the outer frame, you may also be affecting the inner frame. Also, the more "outer" the frame is you're looking at, the more likely a call-clobbered register's value is to be wrong, in the sense that it doesn't actually represent the value the register had just before the call. ---------- Footnotes ---------- (1) This is a way of removing one word from the stack, on machines where stacks grow downward in memory (most machines, nowadays). This assumes that the innermost stack frame is selected; setting `$sp' is not allowed when other stack frames are selected. To pop entire frames off the stack, regardless of machine architecture, use `return'; see *Note Returning from a Function: Returning.  File: gdb.info, Node: Floating Point Hardware, Next: Vector Unit, Prev: Registers, Up: Data 10.15 Floating Point Hardware ============================= Depending on the configuration, GDB may be able to give you more information about the status of the floating point hardware. `info float' Display hardware-dependent information about the floating point unit. The exact contents and layout vary depending on the floating point chip. Currently, `info float' is supported on the ARM and x86 machines.  File: gdb.info, Node: Vector Unit, Next: OS Information, Prev: Floating Point Hardware, Up: Data 10.16 Vector Unit ================= Depending on the configuration, GDB may be able to give you more information about the status of the vector unit. `info vector' Display information about the vector unit. The exact contents and layout vary depending on the hardware.  File: gdb.info, Node: OS Information, Next: Memory Region Attributes, Prev: Vector Unit, Up: Data 10.17 Operating System Auxiliary Information ============================================ GDB provides interfaces to useful OS facilities that can help you debug your program. Some operating systems supply an "auxiliary vector" to programs at startup. This is akin to the arguments and environment that you specify for a program, but contains a system-dependent variety of binary values that tell system libraries important details about the hardware, operating system, and process. Each value's purpose is identified by an integer tag; the meanings are well-known but system-specific. Depending on the configuration and operating system facilities, GDB may be able to show you this information. For remote targets, this functionality may further depend on the remote stub's support of the `qXfer:auxv:read' packet, see *Note qXfer auxiliary vector read::. `info auxv' Display the auxiliary vector of the inferior, which can be either a live process or a core dump file. GDB prints each tag value numerically, and also shows names and text descriptions for recognized tags. Some values in the vector are numbers, some bit masks, and some pointers to strings or other data. GDB displays each value in the most appropriate form for a recognized tag, and in hexadecimal for an unrecognized tag. On some targets, GDB can access operating system-specific information and show it to you. The types of information available will differ depending on the type of operating system running on the target. The mechanism used to fetch the data is described in *Note Operating System Information::. For remote targets, this functionality depends on the remote stub's support of the `qXfer:osdata:read' packet, see *Note qXfer osdata read::. `info os INFOTYPE' Display OS information of the requested type. On GNU/Linux, the following values of INFOTYPE are valid: `cpus' Display the list of all CPUs/cores. For each CPU/core, GDB prints the available fields from /proc/cpuinfo. For each supported architecture different fields are available. Two common entries are processor which gives CPU number and bogomips; a system constant that is calculated during kernel initialization. `files' Display the list of open file descriptors on the target. For each file descriptor, GDB prints the identifier of the process owning the descriptor, the command of the owning process, the value of the descriptor, and the target of the descriptor. `modules' Display the list of all loaded kernel modules on the target. For each module, GDB prints the module name, the size of the module in bytes, the number of times the module is used, the dependencies of the module, the status of the module, and the address of the loaded module in memory. `msg' Display the list of all System V message queues on the target. For each message queue, GDB prints the message queue key, the message queue identifier, the access permissions, the current number of bytes on the queue, the current number of messages on the queue, the processes that last sent and received a message on the queue, the user and group of the owner and creator of the message queue, the times at which a message was last sent and received on the queue, and the time at which the message queue was last changed. `processes' Display the list of processes on the target. For each process, GDB prints the process identifier, the name of the user, the command corresponding to the process, and the list of processor cores that the process is currently running on. (To understand what these properties mean, for this and the following info types, please consult the general GNU/Linux documentation.) `procgroups' Display the list of process groups on the target. For each process, GDB prints the identifier of the process group that it belongs to, the command corresponding to the process group leader, the process identifier, and the command line of the process. The list is sorted first by the process group identifier, then by the process identifier, so that processes belonging to the same process group are grouped together and the process group leader is listed first. `semaphores' Display the list of all System V semaphore sets on the target. For each semaphore set, GDB prints the semaphore set key, the semaphore set identifier, the access permissions, the number of semaphores in the set, the user and group of the owner and creator of the semaphore set, and the times at which the semaphore set was operated upon and changed. `shm' Display the list of all System V shared-memory regions on the target. For each shared-memory region, GDB prints the region key, the shared-memory identifier, the access permissions, the size of the region, the process that created the region, the process that last attached to or detached from the region, the current number of live attaches to the region, and the times at which the region was last attached to, detach from, and changed. `sockets' Display the list of Internet-domain sockets on the target. For each socket, GDB prints the address and port of the local and remote endpoints, the current state of the connection, the creator of the socket, the IP address family of the socket, and the type of the connection. `threads' Display the list of threads running on the target. For each thread, GDB prints the identifier of the process that the thread belongs to, the command of the process, the thread identifier, and the processor core that it is currently running on. The main thread of a process is not listed. `info os' If INFOTYPE is omitted, then list the possible values for INFOTYPE and the kind of OS information available for each INFOTYPE. If the target does not return a list of possible types, this command will report an error.  File: gdb.info, Node: Memory Region Attributes, Next: Dump/Restore Files, Prev: OS Information, Up: Data 10.18 Memory Region Attributes ============================== "Memory region attributes" allow you to describe special handling required by regions of your target's memory. GDB uses attributes to determine whether to allow certain types of memory accesses; whether to use specific width accesses; and whether to cache target memory. By default the description of memory regions is fetched from the target (if the current target supports this), but the user can override the fetched regions. Defined memory regions can be individually enabled and disabled. When a memory region is disabled, GDB uses the default attributes when accessing memory in that region. Similarly, if no memory regions have been defined, GDB uses the default attributes when accessing all memory. When a memory region is defined, it is given a number to identify it; to enable, disable, or remove a memory region, you specify that number. `mem LOWER UPPER ATTRIBUTES...' Define a memory region bounded by LOWER and UPPER with attributes ATTRIBUTES..., and add it to the list of regions monitored by GDB. Note that UPPER == 0 is a special case: it is treated as the target's maximum memory address. (0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.) `mem auto' Discard any user changes to the memory regions and use target-supplied regions, if available, or no regions if the target does not support. `delete mem NUMS...' Remove memory regions NUMS... from the list of regions monitored by GDB. `disable mem NUMS...' Disable monitoring of memory regions NUMS.... A disabled memory region is not forgotten. It may be enabled again later. `enable mem NUMS...' Enable monitoring of memory regions NUMS.... `info mem' Print a table of all defined memory regions, with the following columns for each region: _Memory Region Number_ _Enabled or Disabled._ Enabled memory regions are marked with `y'. Disabled memory regions are marked with `n'. _Lo Address_ The address defining the inclusive lower bound of the memory region. _Hi Address_ The address defining the exclusive upper bound of the memory region. _Attributes_ The list of attributes set for this memory region. 10.18.1 Attributes ------------------ 10.18.1.1 Memory Access Mode ............................ The access mode attributes set whether GDB may make read or write accesses to a memory region. While these attributes prevent GDB from performing invalid memory accesses, they do nothing to prevent the target system, I/O DMA, etc. from accessing memory. `ro' Memory is read only. `wo' Memory is write only. `rw' Memory is read/write. This is the default. 10.18.1.2 Memory Access Size ............................ The access size attribute tells GDB to use specific sized accesses in the memory region. Often memory mapped device registers require specific sized accesses. If no access size attribute is specified, GDB may use accesses of any size. `8' Use 8 bit memory accesses. `16' Use 16 bit memory accesses. `32' Use 32 bit memory accesses. `64' Use 64 bit memory accesses. 10.18.1.3 Data Cache .................... The data cache attributes set whether GDB will cache target memory. While this generally improves performance by reducing debug protocol overhead, it can lead to incorrect results because GDB does not know about volatile variables or memory mapped device registers. `cache' Enable GDB to cache target memory. `nocache' Disable GDB from caching target memory. This is the default. 10.18.2 Memory Access Checking ------------------------------ GDB can be instructed to refuse accesses to memory that is not explicitly described. This can be useful if accessing such regions has undesired effects for a specific target, or to provide better error checking. The following commands control this behaviour. `set mem inaccessible-by-default [on|off]' If `on' is specified, make GDB treat memory not explicitly described by the memory ranges as non-existent and refuse accesses to such memory. The checks are only performed if there's at least one memory range defined. If `off' is specified, make GDB treat the memory not explicitly described by the memory ranges as RAM. The default value is `on'. `show mem inaccessible-by-default' Show the current handling of accesses to unknown memory.  File: gdb.info, Node: Dump/Restore Files, Next: Core File Generation, Prev: Memory Region Attributes, Up: Data 10.19 Copy Between Memory and a File ==================================== You can use the commands `dump', `append', and `restore' to copy data between target memory and a file. The `dump' and `append' commands write data to a file, and the `restore' command reads data from a file back into the inferior's memory. Files may be in binary, Motorola S-record, Intel hex, Tektronix Hex, or Verilog Hex format; however, GDB can only append to binary files, and cannot read from Verilog Hex files. `dump [FORMAT] memory FILENAME START_ADDR END_ADDR' `dump [FORMAT] value FILENAME EXPR' Dump the contents of memory from START_ADDR to END_ADDR, or the value of EXPR, to FILENAME in the given format. The FORMAT parameter may be any one of: `binary' Raw binary form. `ihex' Intel hex format. `srec' Motorola S-record format. `tekhex' Tektronix Hex format. `verilog' Verilog Hex format. GDB uses the same definitions of these formats as the GNU binary utilities, like `objdump' and `objcopy'. If FORMAT is omitted, GDB dumps the data in raw binary form. `append [binary] memory FILENAME START_ADDR END_ADDR' `append [binary] value FILENAME EXPR' Append the contents of memory from START_ADDR to END_ADDR, or the value of EXPR, to the file FILENAME, in raw binary form. (GDB can only append data to files in raw binary form.) `restore FILENAME [binary] BIAS START END' Restore the contents of file FILENAME into memory. The `restore' command can automatically recognize any known BFD file format, except for raw binary. To restore a raw binary file you must specify the optional keyword `binary' after the filename. If BIAS is non-zero, its value will be added to the addresses contained in the file. Binary files always start at address zero, so they will be restored at address BIAS. Other bfd files have a built-in location; they will be restored at offset BIAS from that location. If START and/or END are non-zero, then only data between file offset START and file offset END will be restored. These offsets are relative to the addresses in the file, before the BIAS argument is applied.  File: gdb.info, Node: Core File Generation, Next: Character Sets, Prev: Dump/Restore Files, Up: Data 10.20 How to Produce a Core File from Your Program ================================================== A "core file" or "core dump" is a file that records the memory image of a running process and its process status (register values etc.). Its primary use is post-mortem debugging of a program that crashed while it ran outside a debugger. A program that crashes automatically produces a core file, unless this feature is disabled by the user. *Note Files::, for information on invoking GDB in the post-mortem debugging mode. Occasionally, you may wish to produce a core file of the program you are debugging in order to preserve a snapshot of its state. GDB has a special command for that. `generate-core-file [FILE]' `gcore [FILE]' Produce a core dump of the inferior process. The optional argument FILE specifies the file name where to put the core dump. If not specified, the file name defaults to `core.PID', where PID is the inferior process ID. If supported by the filesystem where the core is written to, GDB generates a sparse core dump file. Note that this command is implemented only for some systems (as of this writing, GNU/Linux, FreeBSD, Solaris, and S390). On GNU/Linux, this command can take into account the value of the file `/proc/PID/coredump_filter' when generating the core dump (*note set use-coredump-filter::), and by default honors the `VM_DONTDUMP' flag for mappings where it is present in the file `/proc/PID/smaps' (*note set dump-excluded-mappings::). `set use-coredump-filter on' `set use-coredump-filter off' Enable or disable the use of the file `/proc/PID/coredump_filter' when generating core dump files. This file is used by the Linux kernel to decide what types of memory mappings will be dumped or ignored when generating a core dump file. PID is the process ID of a currently running process. To make use of this feature, you have to write in the `/proc/PID/coredump_filter' file a value, in hexadecimal, which is a bit mask representing the memory mapping types. If a bit is set in the bit mask, then the memory mappings of the corresponding types will be dumped; otherwise, they will be ignored. This configuration is inherited by child processes. For more information about the bits that can be set in the `/proc/PID/coredump_filter' file, please refer to the manpage of `core(5)'. By default, this option is `on'. If this option is turned `off', GDB does not read the `coredump_filter' file and instead uses the same default value as the Linux kernel in order to decide which pages will be dumped in the core dump file. This value is currently `0x33', which means that bits `0' (anonymous private mappings), `1' (anonymous shared mappings), `4' (ELF headers) and `5' (private huge pages) are active. This will cause these memory mappings to be dumped automatically. `set dump-excluded-mappings on' `set dump-excluded-mappings off' If `on' is specified, GDB will dump memory mappings marked with the `VM_DONTDUMP' flag. This flag is represented in the file `/proc/PID/smaps' with the acronym `dd'. The default value is `off'.  File: gdb.info, Node: Character Sets, Next: Caching Target Data, Prev: Core File Generation, Up: Data 10.21 Character Sets ==================== If the program you are debugging uses a different character set to represent characters and strings than the one GDB uses itself, GDB can automatically translate between the character sets for you. The character set GDB uses we call the "host character set"; the one the inferior program uses we call the "target character set". For example, if you are running GDB on a GNU/Linux system, which uses the ISO Latin 1 character set, but you are using GDB's remote protocol (*note Remote Debugging::) to debug a program running on an IBM mainframe, which uses the EBCDIC character set, then the host character set is Latin-1, and the target character set is EBCDIC. If you give GDB the command `set target-charset EBCDIC-US', then GDB translates between EBCDIC and Latin 1 as you print character or string values, or use character and string literals in expressions. GDB has no way to automatically recognize which character set the inferior program uses; you must tell it, using the `set target-charset' command, described below. Here are the commands for controlling GDB's character set support: `set target-charset CHARSET' Set the current target character set to CHARSET. To display the list of supported target character sets, type `set target-charset '. `set host-charset CHARSET' Set the current host character set to CHARSET. By default, GDB uses a host character set appropriate to the system it is running on; you can override that default using the `set host-charset' command. On some systems, GDB cannot automatically determine the appropriate host character set. In this case, GDB uses `UTF-8'. GDB can only use certain character sets as its host character set. If you type `set host-charset ', GDB will list the host character sets it supports. `set charset CHARSET' Set the current host and target character sets to CHARSET. As above, if you type `set charset ', GDB will list the names of the character sets that can be used for both host and target. `show charset' Show the names of the current host and target character sets. `show host-charset' Show the name of the current host character set. `show target-charset' Show the name of the current target character set. `set target-wide-charset CHARSET' Set the current target's wide character set to CHARSET. This is the character set used by the target's `wchar_t' type. To display the list of supported wide character sets, type `set target-wide-charset '. `show target-wide-charset' Show the name of the current target's wide character set. Here is an example of GDB's character set support in action. Assume that the following source code has been placed in the file `charset-test.c': #include char ascii_hello[] = {72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33, 10, 0}; char ibm1047_hello[] = {200, 133, 147, 147, 150, 107, 64, 166, 150, 153, 147, 132, 90, 37, 0}; main () { printf ("Hello, world!\n"); } In this program, `ascii_hello' and `ibm1047_hello' are arrays containing the string `Hello, world!' followed by a newline, encoded in the ASCII and IBM1047 character sets. We compile the program, and invoke the debugger on it: $ gcc -g charset-test.c -o charset-test $ gdb -nw charset-test GNU gdb 2001-12-19-cvs Copyright 2001 Free Software Foundation, Inc. ... (gdb) We can use the `show charset' command to see what character sets GDB is currently using to interpret and display characters and strings: (gdb) show charset The current host and target character set is `ISO-8859-1'. (gdb) For the sake of printing this manual, let's use ASCII as our initial character set: (gdb) set charset ASCII (gdb) show charset The current host and target character set is `ASCII'. (gdb) Let's assume that ASCII is indeed the correct character set for our host system -- in other words, let's assume that if GDB prints characters using the ASCII character set, our terminal will display them properly. Since our current target character set is also ASCII, the contents of `ascii_hello' print legibly: (gdb) print ascii_hello $1 = 0x401698 "Hello, world!\n" (gdb) print ascii_hello[0] $2 = 72 'H' (gdb) GDB uses the target character set for character and string literals you use in expressions: (gdb) print '+' $3 = 43 '+' (gdb) The ASCII character set uses the number 43 to encode the `+' character. GDB relies on the user to tell it which character set the target program uses. If we print `ibm1047_hello' while our target character set is still ASCII, we get jibberish: (gdb) print ibm1047_hello $4 = 0x4016a8 "\310\205\223\223\226k@@\246\226\231\223\204Z%" (gdb) print ibm1047_hello[0] $5 = 200 '\310' (gdb) If we invoke the `set target-charset' followed by , GDB tells us the character sets it supports: (gdb) set target-charset ASCII EBCDIC-US IBM1047 ISO-8859-1 (gdb) set target-charset We can select IBM1047 as our target character set, and examine the program's strings again. Now the ASCII string is wrong, but GDB translates the contents of `ibm1047_hello' from the target character set, IBM1047, to the host character set, ASCII, and they display correctly: (gdb) set target-charset IBM1047 (gdb) show charset The current host character set is `ASCII'. The current target character set is `IBM1047'. (gdb) print ascii_hello $6 = 0x401698 "\110\145%%?\054\040\167?\162%\144\041\012" (gdb) print ascii_hello[0] $7 = 72 '\110' (gdb) print ibm1047_hello $8 = 0x4016a8 "Hello, world!\n" (gdb) print ibm1047_hello[0] $9 = 200 'H' (gdb) As above, GDB uses the target character set for character and string literals you use in expressions: (gdb) print '+' $10 = 78 '+' (gdb) The IBM1047 character set uses the number 78 to encode the `+' character.  File: gdb.info, Node: Caching Target Data, Next: Searching Memory, Prev: Character Sets, Up: Data 10.22 Caching Data of Targets ============================= GDB caches data exchanged between the debugger and a target. Each cache is associated with the address space of the inferior. *Note Inferiors Connections and Programs::, about inferior and address space. Such caching generally improves performance in remote debugging (*note Remote Debugging::), because it reduces the overhead of the remote protocol by bundling memory reads and writes into large chunks. Unfortunately, simply caching everything would lead to incorrect results, since GDB does not necessarily know anything about volatile values, memory-mapped I/O addresses, etc. Furthermore, in non-stop mode (*note Non-Stop Mode::) memory can be changed _while_ a gdb command is executing. Therefore, by default, GDB only caches data known to be on the stack(1) or in the code segment. Other regions of memory can be explicitly marked as cacheable; *note Memory Region Attributes::. `set remotecache on' `set remotecache off' This option no longer does anything; it exists for compatibility with old scripts. `show remotecache' Show the current state of the obsolete remotecache flag. `set stack-cache on' `set stack-cache off' Enable or disable caching of stack accesses. When `on', use caching. By default, this option is `on'. `show stack-cache' Show the current state of data caching for memory accesses. `set code-cache on' `set code-cache off' Enable or disable caching of code segment accesses. When `on', use caching. By default, this option is `on'. This improves performance of disassembly in remote debugging. `show code-cache' Show the current state of target memory cache for code segment accesses. `info dcache [line]' Print the information about the performance of data cache of the current inferior's address space. The information displayed includes the dcache width and depth, and for each cache line, its number, address, and how many times it was referenced. This command is useful for debugging the data cache operation. If a line number is specified, the contents of that line will be printed in hex. `set dcache size SIZE' Set maximum number of entries in dcache (dcache depth above). `set dcache line-size LINE-SIZE' Set number of bytes each dcache entry caches (dcache width above). Must be a power of 2. `show dcache size' Show maximum number of dcache entries. *Note info dcache: Caching Target Data. `show dcache line-size' Show default size of dcache lines. `maint flush dcache' Flush the contents (if any) of the dcache. This maintainer command is useful when debugging the dcache implementation. ---------- Footnotes ---------- (1) In non-stop mode, it is moderately rare for a running thread to modify the stack of a stopped thread in a way that would interfere with a backtrace, and caching of stack reads provides a significant speed up of remote backtraces.  File: gdb.info, Node: Searching Memory, Next: Value Sizes, Prev: Caching Target Data, Up: Data 10.23 Search Memory =================== Memory can be searched for a particular sequence of bytes with the `find' command. `find [/SN] START_ADDR, +LEN, VAL1 [, VAL2, ...]' `find [/SN] START_ADDR, END_ADDR, VAL1 [, VAL2, ...]' Search memory for the sequence of bytes specified by VAL1, VAL2, etc. The search begins at address START_ADDR and continues for either LEN bytes or through to END_ADDR inclusive. S and N are optional parameters. They may be specified in either order, apart or together. S, search query size The size of each search query value. `b' bytes `h' halfwords (two bytes) `w' words (four bytes) `g' giant words (eight bytes) All values are interpreted in the current language. This means, for example, that if the current source language is C/C++ then searching for the string "hello" includes the trailing '\0'. The null terminator can be removed from searching by using casts, e.g.: `{char[5]}"hello"'. If the value size is not specified, it is taken from the value's type in the current language. This is useful when one wants to specify the search pattern as a mixture of types. Note that this means, for example, that in the case of C-like languages a search for an untyped 0x42 will search for `(int) 0x42' which is typically four bytes. N, maximum number of finds The maximum number of matches to print. The default is to print all finds. You can use strings as search values. Quote them with double-quotes (`"'). The string value is copied into the search pattern byte by byte, regardless of the endianness of the target and the size specification. The address of each match found is printed as well as a count of the number of matches found. The address of the last value found is stored in convenience variable `$_'. A count of the number of matches is stored in `$numfound'. For example, if stopped at the `printf' in this function: void hello () { static char hello[] = "hello-hello"; static struct { char c; short s; int i; } __attribute__ ((packed)) mixed = { 'c', 0x1234, 0x87654321 }; printf ("%s\n", hello); } you get during debugging: (gdb) find &hello[0], +sizeof(hello), "hello" 0x804956d 1 pattern found (gdb) find &hello[0], +sizeof(hello), 'h', 'e', 'l', 'l', 'o' 0x8049567 0x804956d 2 patterns found. (gdb) find &hello[0], +sizeof(hello), {char[5]}"hello" 0x8049567 0x804956d 2 patterns found. (gdb) find /b1 &hello[0], +sizeof(hello), 'h', 0x65, 'l' 0x8049567 1 pattern found (gdb) find &mixed, +sizeof(mixed), (char) 'c', (short) 0x1234, (int) 0x87654321 0x8049560 1 pattern found (gdb) print $numfound $1 = 1 (gdb) print $_ $2 = (void *) 0x8049560  File: gdb.info, Node: Value Sizes, Prev: Searching Memory, Up: Data 10.24 Value Sizes ================= Whenever GDB prints a value memory will be allocated within GDB to hold the contents of the value. It is possible in some languages with dynamic typing systems, that an invalid program may indicate a value that is incorrectly large, this in turn may cause GDB to try and allocate an overly large amount of memory. `set max-value-size BYTES' `set max-value-size unlimited' Set the maximum size of memory that GDB will allocate for the contents of a value to BYTES, trying to display a value that requires more memory than that will result in an error. Setting this variable does not effect values that have already been allocated within GDB, only future allocations. There's a minimum size that `max-value-size' can be set to in order that GDB can still operate correctly, this minimum is currently 16 bytes. The limit applies to the results of some subexpressions as well as to complete expressions. For example, an expression denoting a simple integer component, such as `x.y.z', may fail if the size of X.Y is dynamic and exceeds BYTES. On the other hand, GDB is sometimes clever; the expression `A[i]', where A is an array variable with non-constant size, will generally succeed regardless of the bounds on A, as long as the component size is less than BYTES. The default value of `max-value-size' is currently 64k. `show max-value-size' Show the maximum size of memory, in bytes, that GDB will allocate for the contents of a value.  File: gdb.info, Node: Optimized Code, Next: Macros, Prev: Data, Up: Top 11 Debugging Optimized Code *************************** Almost all compilers support optimization. With optimization disabled, the compiler generates assembly code that corresponds directly to your source code, in a simplistic way. As the compiler applies more powerful optimizations, the generated assembly code diverges from your original source code. With help from debugging information generated by the compiler, GDB can map from the running program back to constructs from your original source. GDB is more accurate with optimization disabled. If you can recompile without optimization, it is easier to follow the progress of your program during debugging. But, there are many cases where you may need to debug an optimized version. When you debug a program compiled with `-g -O', remember that the optimizer has rearranged your code; the debugger shows you what is really there. Do not be too surprised when the execution path does not exactly match your source file! An extreme example: if you define a variable, but never use it, GDB never sees that variable--because the compiler optimizes it out of existence. Some things do not work as well with `-g -O' as with just `-g', particularly on machines with instruction scheduling. If in doubt, recompile with `-g' alone, and if this fixes the problem, please report it to us as a bug (including a test case!). *Note Variables::, for more information about debugging optimized code. * Menu: * Inline Functions:: How GDB presents inlining * Tail Call Frames:: GDB analysis of jumps to functions  File: gdb.info, Node: Inline Functions, Next: Tail Call Frames, Up: Optimized Code 11.1 Inline Functions ===================== "Inlining" is an optimization that inserts a copy of the function body directly at each call site, instead of jumping to a shared routine. GDB displays inlined functions just like non-inlined functions. They appear in backtraces. You can view their arguments and local variables, step into them with `step', skip them with `next', and escape from them with `finish'. You can check whether a function was inlined by using the `info frame' command. For GDB to support inlined functions, the compiler must record information about inlining in the debug information -- GCC using the DWARF 2 format does this, and several other compilers do also. GDB only supports inlined functions when using DWARF 2. Versions of GCC before 4.1 do not emit two required attributes (`DW_AT_call_file' and `DW_AT_call_line'); GDB does not display inlined function calls with earlier versions of GCC. It instead displays the arguments and local variables of inlined functions as local variables in the caller. The body of an inlined function is directly included at its call site; unlike a non-inlined function, there are no instructions devoted to the call. GDB still pretends that the call site and the start of the inlined function are different instructions. Stepping to the call site shows the call site, and then stepping again shows the first line of the inlined function, even though no additional instructions are executed. This makes source-level debugging much clearer; you can see both the context of the call and then the effect of the call. Only stepping by a single instruction using `stepi' or `nexti' does not do this; single instruction steps always show the inlined body. There are some ways that GDB does not pretend that inlined function calls are the same as normal calls: * Setting breakpoints at the call site of an inlined function may not work, because the call site does not contain any code. GDB may incorrectly move the breakpoint to the next line of the enclosing function, after the call. This limitation will be removed in a future version of GDB; until then, set a breakpoint on an earlier line or inside the inlined function instead. * GDB cannot locate the return value of inlined calls after using the `finish' command. This is a limitation of compiler-generated debugging information; after `finish', you can step to the next line and print a variable where your program stored the return value.  File: gdb.info, Node: Tail Call Frames, Prev: Inline Functions, Up: Optimized Code 11.2 Tail Call Frames ===================== Function `B' can call function `C' in its very last statement. In unoptimized compilation the call of `C' is immediately followed by return instruction at the end of `B' code. Optimizing compiler may replace the call and return in function `B' into one jump to function `C' instead. Such use of a jump instruction is called "tail call". During execution of function `C', there will be no indication in the function call stack frames that it was tail-called from `B'. If function `A' regularly calls function `B' which tail-calls function `C', then GDB will see `A' as the caller of `C'. However, in some cases GDB can determine that `C' was tail-called from `B', and it will then create fictitious call frame for that, with the return address set up as if `B' called `C' normally. This functionality is currently supported only by DWARF 2 debugging format and the compiler has to produce `DW_TAG_call_site' tags. With GCC, you need to specify `-O -g' during compilation, to get this information. `info frame' command (*note Frame Info::) will indicate the tail call frame kind by text `tail call frame' such as in this sample GDB output: (gdb) x/i $pc - 2 0x40066b : jmp 0x400640 (gdb) info frame Stack level 1, frame at 0x7fffffffda30: rip = 0x40066d in b (amd64-entry-value.cc:59); saved rip 0x4004c5 tail call frame, caller of frame at 0x7fffffffda30 source language c++. Arglist at unknown address. Locals at unknown address, Previous frame's sp is 0x7fffffffda30 The detection of all the possible code path executions can find them ambiguous. There is no execution history stored (possible *Note Reverse Execution:: is never used for this purpose) and the last known caller could have reached the known callee by multiple different jump sequences. In such case GDB still tries to show at least all the unambiguous top tail callers and all the unambiguous bottom tail callees, if any. `set debug entry-values' When set to on, enables printing of analysis messages for both frame argument values at function entry and tail calls. It will show all the possible valid tail calls code paths it has considered. It will also print the intersection of them with the final unambiguous (possibly partial or even empty) code path result. `show debug entry-values' Show the current state of analysis messages printing for both frame argument values at function entry and tail calls. The analysis messages for tail calls can for example show why the virtual tail call frame for function `c' has not been recognized (due to the indirect reference by variable `x'): static void __attribute__((noinline, noclone)) c (void); void (*x) (void) = c; static void __attribute__((noinline, noclone)) a (void) { x++; } static void __attribute__((noinline, noclone)) c (void) { a (); } int main (void) { x (); return 0; } Breakpoint 1, DW_OP_entry_value resolving cannot find DW_TAG_call_site 0x40039a in main a () at t.c:3 3 static void __attribute__((noinline, noclone)) a (void) { x++; } (gdb) bt #0 a () at t.c:3 #1 0x000000000040039a in main () at t.c:5 Another possibility is an ambiguous virtual tail call frames resolution: int i; static void __attribute__((noinline, noclone)) f (void) { i++; } static void __attribute__((noinline, noclone)) e (void) { f (); } static void __attribute__((noinline, noclone)) d (void) { f (); } static void __attribute__((noinline, noclone)) c (void) { d (); } static void __attribute__((noinline, noclone)) b (void) { if (i) c (); else e (); } static void __attribute__((noinline, noclone)) a (void) { b (); } int main (void) { a (); return 0; } tailcall: initial: 0x4004d2(a) 0x4004ce(b) 0x4004b2(c) 0x4004a2(d) tailcall: compare: 0x4004d2(a) 0x4004cc(b) 0x400492(e) tailcall: reduced: 0x4004d2(a) | (gdb) bt #0 f () at t.c:2 #1 0x00000000004004d2 in a () at t.c:8 #2 0x0000000000400395 in main () at t.c:9 Frames #0 and #2 are real, #1 is a virtual tail call frame. The code can have possible execution paths `main->a->b->c->d->f' or `main->a->b->e->f', GDB cannot find which one from the inferior state. `initial:' state shows some random possible calling sequence GDB has found. It then finds another possible calling sequence - that one is prefixed by `compare:'. The non-ambiguous intersection of these two is printed as the `reduced:' calling sequence. That one could have many further `compare:' and `reduced:' statements as long as there remain any non-ambiguous sequence entries. For the frame of function `b' in both cases there are different possible `$pc' values (`0x4004cc' or `0x4004ce'), therefore this frame is also ambiguous. The only non-ambiguous frame is the one for function `a', therefore this one is displayed to the user while the ambiguous frames are omitted. There can be also reasons why printing of frame argument values at function entry may fail: int v; static void __attribute__((noinline, noclone)) c (int i) { v++; } static void __attribute__((noinline, noclone)) a (int i); static void __attribute__((noinline, noclone)) b (int i) { a (i); } static void __attribute__((noinline, noclone)) a (int i) { if (i) b (i - 1); else c (0); } int main (void) { a (5); return 0; } (gdb) bt #0 c (i=i@@entry=0) at t.c:2 #1 0x0000000000400428 in a (DW_OP_entry_value resolving has found function "a" at 0x400420 can call itself via tail calls i=) at t.c:6 #2 0x000000000040036e in main () at t.c:7 GDB cannot find out from the inferior state if and how many times did function `a' call itself (via function `b') as these calls would be tail calls. Such tail calls would modify the `i' variable, therefore GDB cannot be sure the value it knows would be right - GDB prints `' instead.  File: gdb.info, Node: Macros, Next: Tracepoints, Prev: Optimized Code, Up: Top 12 C Preprocessor Macros ************************ Some languages, such as C and C++, provide a way to define and invoke "preprocessor macros" which expand into strings of tokens. GDB can evaluate expressions containing macro invocations, show the result of macro expansion, and show a macro's definition, including where it was defined. You may need to compile your program specially to provide GDB with information about preprocessor macros. Most compilers do not include macros in their debugging information, even when you compile with the `-g' flag. *Note Compilation::. A program may define a macro at one point, remove that definition later, and then provide a different definition after that. Thus, at different points in the program, a macro may have different definitions, or have no definition at all. If there is a current stack frame, GDB uses the macros in scope at that frame's source code line. Otherwise, GDB uses the macros in scope at the current listing location; see *Note List::. Whenever GDB evaluates an expression, it always expands any macro invocations present in the expression. GDB also provides the following commands for working with macros explicitly. `macro expand EXPRESSION' `macro exp EXPRESSION' Show the results of expanding all preprocessor macro invocations in EXPRESSION. Since GDB simply expands macros, but does not parse the result, EXPRESSION need not be a valid expression; it can be any string of tokens. `macro expand-once EXPRESSION' `macro exp1 EXPRESSION' (This command is not yet implemented.) Show the results of expanding those preprocessor macro invocations that appear explicitly in EXPRESSION. Macro invocations appearing in that expansion are left unchanged. This command allows you to see the effect of a particular macro more clearly, without being confused by further expansions. Since GDB simply expands macros, but does not parse the result, EXPRESSION need not be a valid expression; it can be any string of tokens. `info macro [-a|-all] [--] MACRO' Show the current definition or all definitions of the named MACRO, and describe the source location or compiler command-line where that definition was established. The optional double dash is to signify the end of argument processing and the beginning of MACRO for non C-like macros where the macro may begin with a hyphen. `info macros LOCSPEC' Show all macro definitions that are in effect at the source line of the code location that results from resolving LOCSPEC, and describe the source location or compiler command-line where those definitions were established. `macro define MACRO REPLACEMENT-LIST' `macro define MACRO(ARGLIST) REPLACEMENT-LIST' Introduce a definition for a preprocessor macro named MACRO, invocations of which are replaced by the tokens given in REPLACEMENT-LIST. The first form of this command defines an "object-like" macro, which takes no arguments; the second form defines a "function-like" macro, which takes the arguments given in ARGLIST. A definition introduced by this command is in scope in every expression evaluated in GDB, until it is removed with the `macro undef' command, described below. The definition overrides all definitions for MACRO present in the program being debugged, as well as any previous user-supplied definition. `macro undef MACRO' Remove any user-supplied definition for the macro named MACRO. This command only affects definitions provided with the `macro define' command, described above; it cannot remove definitions present in the program being debugged. `macro list' List all the macros defined using the `macro define' command. Here is a transcript showing the above commands in action. First, we show our source files: $ cat sample.c #include #include "sample.h" #define M 42 #define ADD(x) (M + x) main () { #define N 28 printf ("Hello, world!\n"); #undef N printf ("We're so creative.\n"); #define N 1729 printf ("Goodbye, world!\n"); } $ cat sample.h #define Q < $ Now, we compile the program using the GNU C compiler, GCC. We pass the `-gdwarf-2'(1) _and_ `-g3' flags to ensure the compiler includes information about preprocessor macros in the debugging information. $ gcc -gdwarf-2 -g3 sample.c -o sample $ Now, we start GDB on our sample program: $ gdb -nw sample GNU gdb 2002-05-06-cvs Copyright 2002 Free Software Foundation, Inc. GDB is free software, ... (gdb) We can expand macros and examine their definitions, even when the program is not running. GDB uses the current listing position to decide which macro definitions are in scope: (gdb) list main 3 4 #define M 42 5 #define ADD(x) (M + x) 6 7 main () 8 { 9 #define N 28 10 printf ("Hello, world!\n"); 11 #undef N 12 printf ("We're so creative.\n"); (gdb) info macro ADD Defined at /home/jimb/gdb/macros/play/sample.c:5 #define ADD(x) (M + x) (gdb) info macro Q Defined at /home/jimb/gdb/macros/play/sample.h:1 included at /home/jimb/gdb/macros/play/sample.c:2 #define Q < (gdb) macro expand ADD(1) expands to: (42 + 1) (gdb) macro expand-once ADD(1) expands to: once (M + 1) (gdb) In the example above, note that `macro expand-once' expands only the macro invocation explicit in the original text -- the invocation of `ADD' -- but does not expand the invocation of the macro `M', which was introduced by `ADD'. Once the program is running, GDB uses the macro definitions in force at the source line of the current stack frame: (gdb) break main Breakpoint 1 at 0x8048370: file sample.c, line 10. (gdb) run Starting program: /home/jimb/gdb/macros/play/sample Breakpoint 1, main () at sample.c:10 10 printf ("Hello, world!\n"); (gdb) At line 10, the definition of the macro `N' at line 9 is in force: (gdb) info macro N Defined at /home/jimb/gdb/macros/play/sample.c:9 #define N 28 (gdb) macro expand N Q M expands to: 28 < 42 (gdb) print N Q M $1 = 1 (gdb) As we step over directives that remove `N''s definition, and then give it a new definition, GDB finds the definition (or lack thereof) in force at each point: (gdb) next Hello, world! 12 printf ("We're so creative.\n"); (gdb) info macro N The symbol `N' has no definition as a C/C++ preprocessor macro at /home/jimb/gdb/macros/play/sample.c:12 (gdb) next We're so creative. 14 printf ("Goodbye, world!\n"); (gdb) info macro N Defined at /home/jimb/gdb/macros/play/sample.c:13 #define N 1729 (gdb) macro expand N Q M expands to: 1729 < 42 (gdb) print N Q M $2 = 0 (gdb) In addition to source files, macros can be defined on the compilation command line using the `-DNAME=VALUE' syntax. For macros defined in such a way, GDB displays the location of their definition as line zero of the source file submitted to the compiler. (gdb) info macro __STDC__ Defined at /home/jimb/gdb/macros/play/sample.c:0 -D__STDC__=1 (gdb) ---------- Footnotes ---------- (1) This is the minimum. Recent versions of GCC support `-gdwarf-3' and `-gdwarf-4'; we recommend always choosing the most recent version of DWARF.  File: gdb.info, Node: Tracepoints, Next: Overlays, Prev: Macros, Up: Top 13 Tracepoints ************** In some applications, it is not feasible for the debugger to interrupt the program's execution long enough for the developer to learn anything helpful about its behavior. If the program's correctness depends on its real-time behavior, delays introduced by a debugger might cause the program to change its behavior drastically, or perhaps fail, even when the code itself is correct. It is useful to be able to observe the program's behavior without interrupting it. Using GDB's `trace' and `collect' commands, you can specify locations in the program, called "tracepoints", and arbitrary expressions to evaluate when those tracepoints are reached. Later, using the `tfind' command, you can examine the values those expressions had when the program hit the tracepoints. The expressions may also denote objects in memory--structures or arrays, for example--whose values GDB should record; while visiting a particular tracepoint, you may inspect those objects as if they were in memory at that moment. However, because GDB records these values without interacting with you, it can do so quickly and unobtrusively, hopefully not disturbing the program's behavior. The tracepoint facility is currently available only for remote targets. *Note Targets::. In addition, your remote target must know how to collect trace data. This functionality is implemented in the remote stub; however, none of the stubs distributed with GDB support tracepoints as of this writing. The format of the remote packets used to implement tracepoints are described in *Note Tracepoint Packets::. It is also possible to get trace data from a file, in a manner reminiscent of corefiles; you specify the filename, and use `tfind' to search through the file. *Note Trace Files::, for more details. This chapter describes the tracepoint commands and features. * Menu: * Set Tracepoints:: * Analyze Collected Data:: * Tracepoint Variables:: * Trace Files::  File: gdb.info, Node: Set Tracepoints, Next: Analyze Collected Data, Up: Tracepoints 13.1 Commands to Set Tracepoints ================================ Before running such a "trace experiment", an arbitrary number of tracepoints can be set. A tracepoint is actually a special type of breakpoint (*note Set Breaks::), so you can manipulate it using standard breakpoint commands. For instance, as with breakpoints, tracepoint numbers are successive integers starting from one, and many of the commands associated with tracepoints take the tracepoint number as their argument, to identify which tracepoint to work on. For each tracepoint, you can specify, in advance, some arbitrary set of data that you want the target to collect in the trace buffer when it hits that tracepoint. The collected data can include registers, local variables, or global data. Later, you can use GDB commands to examine the values these data had at the time the tracepoint was hit. Tracepoints do not support every breakpoint feature. Ignore counts on tracepoints have no effect, and tracepoints cannot run GDB commands when they are hit. Tracepoints may not be thread-specific either. Some targets may support "fast tracepoints", which are inserted in a different way (such as with a jump instead of a trap), that is faster but possibly restricted in where they may be installed. Regular and fast tracepoints are dynamic tracing facilities, meaning that they can be used to insert tracepoints at (almost) any location in the target. Some targets may also support controlling "static tracepoints" from GDB. With static tracing, a set of instrumentation points, also known as "markers", are embedded in the target program, and can be activated or deactivated by name or address. These are usually placed at locations which facilitate investigating what the target is actually doing. GDB's support for static tracing includes being able to list instrumentation points, and attach them with GDB defined high level tracepoints that expose the whole range of convenience of GDB's tracepoints support. Namely, support for collecting registers values and values of global or local (to the instrumentation point) variables; tracepoint conditions and trace state variables. The act of installing a GDB static tracepoint on an instrumentation point, or marker, is referred to as "probing" a static tracepoint marker. `gdbserver' supports tracepoints on some target systems. *Note Tracepoints support in `gdbserver': Server. This section describes commands to set tracepoints and associated conditions and actions. * Menu: * Create and Delete Tracepoints:: * Enable and Disable Tracepoints:: * Tracepoint Passcounts:: * Tracepoint Conditions:: * Trace State Variables:: * Tracepoint Actions:: * Listing Tracepoints:: * Listing Static Tracepoint Markers:: * Starting and Stopping Trace Experiments:: * Tracepoint Restrictions::  File: gdb.info, Node: Create and Delete Tracepoints, Next: Enable and Disable Tracepoints, Up: Set Tracepoints 13.1.1 Create and Delete Tracepoints ------------------------------------ `trace LOCSPEC' The `trace' command is very similar to the `break' command. Its argument LOCSPEC can be any valid location specification. *Note Location Specifications::. The `trace' command defines a tracepoint, which is a point in the target program where the debugger will briefly stop, collect some data, and then allow the program to continue. Setting a tracepoint or changing its actions takes effect immediately if the remote stub supports the `InstallInTrace' feature (*note install tracepoint in tracing::). If remote stub doesn't support the `InstallInTrace' feature, all these changes don't take effect until the next `tstart' command, and once a trace experiment is running, further changes will not have any effect until the next trace experiment starts. In addition, GDB supports "pending tracepoints"--tracepoints whose address is not yet resolved. (This is similar to pending breakpoints.) Pending tracepoints are not downloaded to the target and not installed until they are resolved. The resolution of pending tracepoints requires GDB support--when debugging with the remote target, and GDB disconnects from the remote stub (*note disconnected tracing::), pending tracepoints can not be resolved (and downloaded to the remote stub) while GDB is disconnected. Here are some examples of using the `trace' command: (gdb) trace foo.c:121 // a source file and line number (gdb) trace +2 // 2 lines forward (gdb) trace my_function // first source line of function (gdb) trace *my_function // EXACT start address of function (gdb) trace *0x2117c4 // an address You can abbreviate `trace' as `tr'. `trace LOCSPEC if COND' Set a tracepoint with condition COND; evaluate the expression COND each time the tracepoint is reached, and collect data only if the value is nonzero--that is, if COND evaluates as true. *Note Tracepoint Conditions: Tracepoint Conditions, for more information on tracepoint conditions. `ftrace LOCSPEC [ if COND ]' The `ftrace' command sets a fast tracepoint. For targets that support them, fast tracepoints will use a more efficient but possibly less general technique to trigger data collection, such as a jump instruction instead of a trap, or some sort of hardware support. It may not be possible to create a fast tracepoint at the desired location, in which case the command will exit with an explanatory message. GDB handles arguments to `ftrace' exactly as for `trace'. On 32-bit x86-architecture systems, fast tracepoints normally need to be placed at an instruction that is 5 bytes or longer, but can be placed at 4-byte instructions if the low 64K of memory of the target program is available to install trampolines. Some Unix-type systems, such as GNU/Linux, exclude low addresses from the program's address space; but for instance with the Linux kernel it is possible to let GDB use this area by doing a `sysctl' command to set the `mmap_min_addr' kernel parameter, as in sudo sysctl -w vm.mmap_min_addr=32768 which sets the low address to 32K, which leaves plenty of room for trampolines. The minimum address should be set to a page boundary. `strace [LOCSPEC | -m MARKER] [ if COND ]' The `strace' command sets a static tracepoint. For targets that support it, setting a static tracepoint probes a static instrumentation point, or marker, found at the code locations that result from resolving LOCSPEC. It may not be possible to set a static tracepoint at the desired code location, in which case the command will exit with an explanatory message. GDB handles arguments to `strace' exactly as for `trace', with the addition that the user can also specify `-m MARKER' instead of a location spec. This probes the marker identified by the MARKER string identifier. This identifier depends on the static tracepoint backend library your program is using. You can find all the marker identifiers in the `ID' field of the `info static-tracepoint-markers' command output. *Note Listing Static Tracepoint Markers: Listing Static Tracepoint Markers. For example, in the following small program using the UST tracing engine: main () { trace_mark(ust, bar33, "str %s", "FOOBAZ"); } the marker id is composed of joining the first two arguments to the `trace_mark' call with a slash, which translates to: (gdb) info static-tracepoint-markers Cnt Enb ID Address What 1 n ust/bar33 0x0000000000400ddc in main at stexample.c:22 Data: "str %s" [etc...] so you may probe the marker above with: (gdb) strace -m ust/bar33 Static tracepoints accept an extra collect action -- `collect $_sdata'. This collects arbitrary user data passed in the probe point call to the tracing library. In the UST example above, you'll see that the third argument to `trace_mark' is a printf-like format string. The user data is then the result of running that formatting string against the following arguments. Note that `info static-tracepoint-markers' command output lists that format string in the `Data:' field. You can inspect this data when analyzing the trace buffer, by printing the $_sdata variable like any other variable available to GDB. *Note Tracepoint Action Lists: Tracepoint Actions. The convenience variable `$tpnum' records the tracepoint number of the most recently set tracepoint. `delete tracepoint [NUM]' Permanently delete one or more tracepoints. With no argument, the default is to delete all tracepoints. Note that the regular `delete' command can remove tracepoints also. Examples: (gdb) delete trace 1 2 3 // remove three tracepoints (gdb) delete trace // remove all tracepoints You can abbreviate this command as `del tr'.  File: gdb.info, Node: Enable and Disable Tracepoints, Next: Tracepoint Passcounts, Prev: Create and Delete Tracepoints, Up: Set Tracepoints 13.1.2 Enable and Disable Tracepoints ------------------------------------- These commands are deprecated; they are equivalent to plain `disable' and `enable'. `disable tracepoint [NUM]' Disable tracepoint NUM, or all tracepoints if no argument NUM is given. A disabled tracepoint will have no effect during a trace experiment, but it is not forgotten. You can re-enable a disabled tracepoint using the `enable tracepoint' command. If the command is issued during a trace experiment and the debug target has support for disabling tracepoints during a trace experiment, then the change will be effective immediately. Otherwise, it will be applied to the next trace experiment. `enable tracepoint [NUM]' Enable tracepoint NUM, or all tracepoints. If this command is issued during a trace experiment and the debug target supports enabling tracepoints during a trace experiment, then the enabled tracepoints will become effective immediately. Otherwise, they will become effective the next time a trace experiment is run.  File: gdb.info, Node: Tracepoint Passcounts, Next: Tracepoint Conditions, Prev: Enable and Disable Tracepoints, Up: Set Tracepoints 13.1.3 Tracepoint Passcounts ---------------------------- `passcount [N [NUM]]' Set the "passcount" of a tracepoint. The passcount is a way to automatically stop a trace experiment. If a tracepoint's passcount is N, then the trace experiment will be automatically stopped on the N'th time that tracepoint is hit. If the tracepoint number NUM is not specified, the `passcount' command sets the passcount of the most recently defined tracepoint. If no passcount is given, the trace experiment will run until stopped explicitly by the user. Examples: (gdb) passcount 5 2 // Stop on the 5th execution of `// tracepoint 2' (gdb) passcount 12 // Stop on the 12th execution of the `// most recently defined tracepoint.' (gdb) trace foo (gdb) pass 3 (gdb) trace bar (gdb) pass 2 (gdb) trace baz (gdb) pass 1 // Stop tracing when foo has been `// executed 3 times OR when bar has' `// been executed 2 times' `// OR when baz has been executed 1 time.'  File: gdb.info, Node: Tracepoint Conditions, Next: Trace State Variables, Prev: Tracepoint Passcounts, Up: Set Tracepoints 13.1.4 Tracepoint Conditions ---------------------------- The simplest sort of tracepoint collects data every time your program reaches a specified place. You can also specify a "condition" for a tracepoint. A condition is just a Boolean expression in your programming language (*note Expressions: Expressions.). A tracepoint with a condition evaluates the expression each time your program reaches it, and data collection happens only if the condition is true. Tracepoint conditions can be specified when a tracepoint is set, by using `if' in the arguments to the `trace' command. *Note Setting Tracepoints: Create and Delete Tracepoints. They can also be set or changed at any time with the `condition' command, just as with breakpoints. Unlike breakpoint conditions, GDB does not actually evaluate the conditional expression itself. Instead, GDB encodes the expression into an agent expression (*note Agent Expressions::) suitable for execution on the target, independently of GDB. Global variables become raw memory locations, locals become stack accesses, and so forth. For instance, suppose you have a function that is usually called frequently, but should not be called after an error has occurred. You could use the following tracepoint command to collect data about calls of that function that happen while the error code is propagating through the program; an unconditional tracepoint could end up collecting thousands of useless trace frames that you would have to search through. (gdb) trace normal_operation if errcode > 0  File: gdb.info, Node: Trace State Variables, Next: Tracepoint Actions, Prev: Tracepoint Conditions, Up: Set Tracepoints 13.1.5 Trace State Variables ---------------------------- A "trace state variable" is a special type of variable that is created and managed by target-side code. The syntax is the same as that for GDB's convenience variables (a string prefixed with "$"), but they are stored on the target. They must be created explicitly, using a `tvariable' command. They are always 64-bit signed integers. Trace state variables are remembered by GDB, and downloaded to the target along with tracepoint information when the trace experiment starts. There are no intrinsic limits on the number of trace state variables, beyond memory limitations of the target. Although trace state variables are managed by the target, you can use them in print commands and expressions as if they were convenience variables; GDB will get the current value from the target while the trace experiment is running. Trace state variables share the same namespace as other "$" variables, which means that you cannot have trace state variables with names like `$23' or `$pc', nor can you have a trace state variable and a convenience variable with the same name. `tvariable $NAME [ = EXPRESSION ]' The `tvariable' command creates a new trace state variable named `$NAME', and optionally gives it an initial value of EXPRESSION. The EXPRESSION is evaluated when this command is entered; the result will be converted to an integer if possible, otherwise GDB will report an error. A subsequent `tvariable' command specifying the same name does not create a variable, but instead assigns the supplied initial value to the existing variable of that name, overwriting any previous initial value. The default initial value is 0. `info tvariables' List all the trace state variables along with their initial values. Their current values may also be displayed, if the trace experiment is currently running. `delete tvariable [ $NAME ... ]' Delete the given trace state variables, or all of them if no arguments are specified.  File: gdb.info, Node: Tracepoint Actions, Next: Listing Tracepoints, Prev: Trace State Variables, Up: Set Tracepoints 13.1.6 Tracepoint Action Lists ------------------------------ `actions [NUM]' This command will prompt for a list of actions to be taken when the tracepoint is hit. If the tracepoint number NUM is not specified, this command sets the actions for the one that was most recently defined (so that you can define a tracepoint and then say `actions' without bothering about its number). You specify the actions themselves on the following lines, one action at a time, and terminate the actions list with a line containing just `end'. So far, the only defined actions are `collect', `teval', and `while-stepping'. `actions' is actually equivalent to `commands' (*note Breakpoint Command Lists: Break Commands.), except that only the defined actions are allowed; any other GDB command is rejected. To remove all actions from a tracepoint, type `actions NUM' and follow it immediately with `end'. (gdb) collect DATA // collect some data (gdb) while-stepping 5 // single-step 5 times, collect data (gdb) end // signals the end of actions. In the following example, the action list begins with `collect' commands indicating the things to be collected when the tracepoint is hit. Then, in order to single-step and collect additional data following the tracepoint, a `while-stepping' command is used, followed by the list of things to be collected after each step in a sequence of single steps. The `while-stepping' command is terminated by its own separate `end' command. Lastly, the action list is terminated by an `end' command. (gdb) trace foo (gdb) actions Enter actions for tracepoint 1, one per line: > collect bar,baz > collect $regs > while-stepping 12 > collect $pc, arr[i] > end end `collect[/MODS] EXPR1, EXPR2, ...' Collect values of the given expressions when the tracepoint is hit. This command accepts a comma-separated list of any valid expressions. In addition to global, static, or local variables, the following special arguments are supported: `$regs' Collect all registers. `$args' Collect all function arguments. `$locals' Collect all local variables. `$_ret' Collect the return address. This is helpful if you want to see more of a backtrace. _Note:_ The return address location can not always be reliably determined up front, and the wrong address / registers may end up collected instead. On some architectures the reliability is higher for tracepoints at function entry, while on others it's the opposite. When this happens, backtracing will stop because the return address is found unavailable (unless another collect rule happened to match it). `$_probe_argc' Collects the number of arguments from the static probe at which the tracepoint is located. *Note Static Probe Points::. `$_probe_argN' N is an integer between 0 and 11. Collects the Nth argument from the static probe at which the tracepoint is located. *Note Static Probe Points::. `$_sdata' Collect static tracepoint marker specific data. Only available for static tracepoints. *Note Tracepoint Action Lists: Tracepoint Actions. On the UST static tracepoints library backend, an instrumentation point resembles a `printf' function call. The tracing library is able to collect user specified data formatted to a character string using the format provided by the programmer that instrumented the program. Other backends have similar mechanisms. Here's an example of a UST marker call: const char master_name[] = "$your_name"; trace_mark(channel1, marker1, "hello %s", master_name) In this case, collecting `$_sdata' collects the string `hello $yourname'. When analyzing the trace buffer, you can inspect `$_sdata' like any other variable available to GDB. You can give several consecutive `collect' commands, each one with a single argument, or one `collect' command with several arguments separated by commas; the effect is the same. The optional MODS changes the usual handling of the arguments. `s' requests that pointers to chars be handled as strings, in particular collecting the contents of the memory being pointed at, up to the first zero. The upper bound is by default the value of the `print characters' variable; if `s' is followed by a decimal number, that is the upper bound instead. So for instance `collect/s25 mystr' collects as many as 25 characters at `mystr'. The command `info scope' (*note info scope: Symbols.) is particularly useful for figuring out what data to collect. `teval EXPR1, EXPR2, ...' Evaluate the given expressions when the tracepoint is hit. This command accepts a comma-separated list of expressions. The results are discarded, so this is mainly useful for assigning values to trace state variables (*note Trace State Variables::) without adding those values to the trace buffer, as would be the case if the `collect' action were used. `while-stepping N' Perform N single-step instruction traces after the tracepoint, collecting new data after each step. The `while-stepping' command is followed by the list of what to collect while stepping (followed by its own `end' command): > while-stepping 12 > collect $regs, myglobal > end > Note that `$pc' is not automatically collected by `while-stepping'; you need to explicitly collect that register if you need it. You may abbreviate `while-stepping' as `ws' or `stepping'. `set default-collect EXPR1, EXPR2, ...' This variable is a list of expressions to collect at each tracepoint hit. It is effectively an additional `collect' action prepended to every tracepoint action list. The expressions are parsed individually for each tracepoint, so for instance a variable named `xyz' may be interpreted as a global for one tracepoint, and a local for another, as appropriate to the tracepoint's location. `show default-collect' Show the list of expressions that are collected by default at each tracepoint hit.  File: gdb.info, Node: Listing Tracepoints, Next: Listing Static Tracepoint Markers, Prev: Tracepoint Actions, Up: Set Tracepoints 13.1.7 Listing Tracepoints -------------------------- `info tracepoints [NUM...]' Display information about the tracepoint NUM. If you don't specify a tracepoint number, displays information about all the tracepoints defined so far. The format is similar to that used for `info breakpoints'; in fact, `info tracepoints' is the same command, simply restricting itself to tracepoints. A tracepoint's listing may include additional information specific to tracing: * its passcount as given by the `passcount N' command * the state about installed on target of each location (gdb) info trace Num Type Disp Enb Address What 1 tracepoint keep y 0x0804ab57 in foo() at main.cxx:7 while-stepping 20 collect globfoo, $regs end collect globfoo2 end pass count 1200 2 tracepoint keep y collect $eip 2.1 y 0x0804859c in func4 at change-loc.h:35 installed on target 2.2 y 0xb7ffc480 in func4 at change-loc.h:35 installed on target 2.3 y set_tracepoint 3 tracepoint keep y 0x080485b1 in foo at change-loc.c:29 not installed on target (gdb) This command can be abbreviated `info tp'.  File: gdb.info, Node: Listing Static Tracepoint Markers, Next: Starting and Stopping Trace Experiments, Prev: Listing Tracepoints, Up: Set Tracepoints 13.1.8 Listing Static Tracepoint Markers ---------------------------------------- `info static-tracepoint-markers' Display information about all static tracepoint markers defined in the program. For each marker, the following columns are printed: _Count_ An incrementing counter, output to help readability. This is not a stable identifier. _ID_ The marker ID, as reported by the target. _Enabled or Disabled_ Probed markers are tagged with `y'. `n' identifies marks that are not enabled. _Address_ Where the marker is in your program, as a memory address. _What_ Where the marker is in the source for your program, as a file and line number. If the debug information included in the program does not allow GDB to locate the source of the marker, this column will be left blank. In addition, the following information may be printed for each marker: _Data_ User data passed to the tracing library by the marker call. In the UST backend, this is the format string passed as argument to the marker call. _Static tracepoints probing the marker_ The list of static tracepoints attached to the marker. (gdb) info static-tracepoint-markers Cnt ID Enb Address What 1 ust/bar2 y 0x0000000000400e1a in main at stexample.c:25 Data: number1 %d number2 %d Probed by static tracepoints: #2 2 ust/bar33 n 0x0000000000400c87 in main at stexample.c:24 Data: str %s (gdb)  File: gdb.info, Node: Starting and Stopping Trace Experiments, Next: Tracepoint Restrictions, Prev: Listing Static Tracepoint Markers, Up: Set Tracepoints 13.1.9 Starting and Stopping Trace Experiments ---------------------------------------------- `tstart' This command starts the trace experiment, and begins collecting data. It has the side effect of discarding all the data collected in the trace buffer during the previous trace experiment. If any arguments are supplied, they are taken as a note and stored with the trace experiment's state. The notes may be arbitrary text, and are especially useful with disconnected tracing in a multi-user context; the notes can explain what the trace is doing, supply user contact information, and so forth. `tstop' This command stops the trace experiment. If any arguments are supplied, they are recorded with the experiment as a note. This is useful if you are stopping a trace started by someone else, for instance if the trace is interfering with the system's behavior and needs to be stopped quickly. *Note*: a trace experiment and data collection may stop automatically if any tracepoint's passcount is reached (*note Tracepoint Passcounts::), or if the trace buffer becomes full. `tstatus' This command displays the status of the current trace data collection. Here is an example of the commands we described so far: (gdb) trace gdb_c_test (gdb) actions Enter actions for tracepoint #1, one per line. > collect $regs,$locals,$args > while-stepping 11 > collect $regs > end > end (gdb) tstart [time passes ...] (gdb) tstop You can choose to continue running the trace experiment even if GDB disconnects from the target, voluntarily or involuntarily. For commands such as `detach', the debugger will ask what you want to do with the trace. But for unexpected terminations (GDB crash, network outage), it would be unfortunate to lose hard-won trace data, so the variable `disconnected-tracing' lets you decide whether the trace should continue running without GDB. `set disconnected-tracing on' `set disconnected-tracing off' Choose whether a tracing run should continue to run if GDB has disconnected from the target. Note that `detach' or `quit' will ask you directly what to do about a running trace no matter what this variable's setting, so the variable is mainly useful for handling unexpected situations, such as loss of the network. `show disconnected-tracing' Show the current choice for disconnected tracing. When you reconnect to the target, the trace experiment may or may not still be running; it might have filled the trace buffer in the meantime, or stopped for one of the other reasons. If it is running, it will continue after reconnection. Upon reconnection, the target will upload information about the tracepoints in effect. GDB will then compare that information to the set of tracepoints currently defined, and attempt to match them up, allowing for the possibility that the numbers may have changed due to creation and deletion in the meantime. If one of the target's tracepoints does not match any in GDB, the debugger will create a new tracepoint, so that you have a number with which to specify that tracepoint. This matching-up process is necessarily heuristic, and it may result in useless tracepoints being created; you may simply delete them if they are of no use. If your target agent supports a "circular trace buffer", then you can run a trace experiment indefinitely without filling the trace buffer; when space runs out, the agent deletes already-collected trace frames, oldest first, until there is enough room to continue collecting. This is especially useful if your tracepoints are being hit too often, and your trace gets terminated prematurely because the buffer is full. To ask for a circular trace buffer, simply set `circular-trace-buffer' to on. You can set this at any time, including during tracing; if the agent can do it, it will change buffer handling on the fly, otherwise it will not take effect until the next run. `set circular-trace-buffer on' `set circular-trace-buffer off' Choose whether a tracing run should use a linear or circular buffer for trace data. A linear buffer will not lose any trace data, but may fill up prematurely, while a circular buffer will discard old trace data, but it will have always room for the latest tracepoint hits. `show circular-trace-buffer' Show the current choice for the trace buffer. Note that this may not match the agent's current buffer handling, nor is it guaranteed to match the setting that might have been in effect during a past run, for instance if you are looking at frames from a trace file. `set trace-buffer-size N' `set trace-buffer-size unlimited' Request that the target use a trace buffer of N bytes. Not all targets will honor the request; they may have a compiled-in size for the trace buffer, or some other limitation. Set to a value of `unlimited' or `-1' to let the target use whatever size it likes. This is also the default. `show trace-buffer-size' Show the current requested size for the trace buffer. Note that this will only match the actual size if the target supports size-setting, and was able to handle the requested size. For instance, if the target can only change buffer size between runs, this variable will not reflect the change until the next run starts. Use `tstatus' to get a report of the actual buffer size. `set trace-user TEXT' `show trace-user' `set trace-notes TEXT' Set the trace run's notes. `show trace-notes' Show the trace run's notes. `set trace-stop-notes TEXT' Set the trace run's stop notes. The handling of the note is as for `tstop' arguments; the set command is convenient way to fix a stop note that is mistaken or incomplete. `show trace-stop-notes' Show the trace run's stop notes.  File: gdb.info, Node: Tracepoint Restrictions, Prev: Starting and Stopping Trace Experiments, Up: Set Tracepoints 13.1.10 Tracepoint Restrictions ------------------------------- There are a number of restrictions on the use of tracepoints. As described above, tracepoint data gathering occurs on the target without interaction from GDB. Thus the full capabilities of the debugger are not available during data gathering, and then at data examination time, you will be limited by only having what was collected. The following items describe some common problems, but it is not exhaustive, and you may run into additional difficulties not mentioned here. * Tracepoint expressions are intended to gather objects (lvalues). Thus the full flexibility of GDB's expression evaluator is not available. You cannot call functions, cast objects to aggregate types, access convenience variables or modify values (except by assignment to trace state variables). Some language features may implicitly call functions (for instance Objective-C fields with accessors), and therefore cannot be collected either. * Collection of local variables, either individually or in bulk with `$locals' or `$args', during `while-stepping' may behave erratically. The stepping action may enter a new scope (for instance by stepping into a function), or the location of the variable may change (for instance it is loaded into a register). The tracepoint data recorded uses the location information for the variables that is correct for the tracepoint location. When the tracepoint is created, it is not possible, in general, to determine where the steps of a `while-stepping' sequence will advance the program--particularly if a conditional branch is stepped. * Collection of an incompletely-initialized or partially-destroyed object may result in something that GDB cannot display, or displays in a misleading way. * When GDB displays a pointer to character it automatically dereferences the pointer to also display characters of the string being pointed to. However, collecting the pointer during tracing does not automatically collect the string. You need to explicitly dereference the pointer and provide size information if you want to collect not only the pointer, but the memory pointed to. For example, `*ptr@@50' can be used to collect the 50 element array pointed to by `ptr'. * It is not possible to collect a complete stack backtrace at a tracepoint. Instead, you may collect the registers and a few hundred bytes from the stack pointer with something like `*(unsigned char *)$esp@@300' (adjust to use the name of the actual stack pointer register on your target architecture, and the amount of stack you wish to capture). Then the `backtrace' command will show a partial backtrace when using a trace frame. The number of stack frames that can be examined depends on the sizes of the frames in the collected stack. Note that if you ask for a block so large that it goes past the bottom of the stack, the target agent may report an error trying to read from an invalid address. * If you do not collect registers at a tracepoint, GDB can infer that the value of `$pc' must be the same as the address of the tracepoint and use that when you are looking at a trace frame for that tracepoint. However, this cannot work if the tracepoint has multiple locations (for instance if it was set in a function that was inlined), or if it has a `while-stepping' loop. In those cases GDB will warn you that it can't infer `$pc', and default it to zero.  File: gdb.info, Node: Analyze Collected Data, Next: Tracepoint Variables, Prev: Set Tracepoints, Up: Tracepoints 13.2 Using the Collected Data ============================= After the tracepoint experiment ends, you use GDB commands for examining the trace data. The basic idea is that each tracepoint collects a trace "snapshot" every time it is hit and another snapshot every time it single-steps. All these snapshots are consecutively numbered from zero and go into a buffer, and you can examine them later. The way you examine them is to "focus" on a specific trace snapshot. When the remote stub is focused on a trace snapshot, it will respond to all GDB requests for memory and registers by reading from the buffer which belongs to that snapshot, rather than from _real_ memory or registers of the program being debugged. This means that *all* GDB commands (`print', `info registers', `backtrace', etc.) will behave as if we were currently debugging the program state as it was when the tracepoint occurred. Any requests for data that are not in the buffer will fail. * Menu: * tfind:: How to select a trace snapshot * tdump:: How to display all data for a snapshot * save tracepoints:: How to save tracepoints for a future run  File: gdb.info, Node: tfind, Next: tdump, Up: Analyze Collected Data 13.2.1 `tfind N' ---------------- The basic command for selecting a trace snapshot from the buffer is `tfind N', which finds trace snapshot number N, counting from zero. If no argument N is given, the next snapshot is selected. Here are the various forms of using the `tfind' command. `tfind start' Find the first snapshot in the buffer. This is a synonym for `tfind 0' (since 0 is the number of the first snapshot). `tfind none' Stop debugging trace snapshots, resume _live_ debugging. `tfind end' Same as `tfind none'. `tfind' No argument means find the next trace snapshot or find the first one if no trace snapshot is selected. `tfind -' Find the previous trace snapshot before the current one. This permits retracing earlier steps. `tfind tracepoint NUM' Find the next snapshot associated with tracepoint NUM. Search proceeds forward from the last examined trace snapshot. If no argument NUM is given, it means find the next snapshot collected for the same tracepoint as the current snapshot. `tfind pc ADDR' Find the next snapshot associated with the value ADDR of the program counter. Search proceeds forward from the last examined trace snapshot. If no argument ADDR is given, it means find the next snapshot with the same value of PC as the current snapshot. `tfind outside ADDR1, ADDR2' Find the next snapshot whose PC is outside the given range of addresses (exclusive). `tfind range ADDR1, ADDR2' Find the next snapshot whose PC is between ADDR1 and ADDR2 (inclusive). `tfind line [FILE:]N' Find the next snapshot associated with the source line N. If the optional argument FILE is given, refer to line N in that source file. Search proceeds forward from the last examined trace snapshot. If no argument N is given, it means find the next line other than the one currently being examined; thus saying `tfind line' repeatedly can appear to have the same effect as stepping from line to line in a _live_ debugging session. The default arguments for the `tfind' commands are specifically designed to make it easy to scan through the trace buffer. For instance, `tfind' with no argument selects the next trace snapshot, and `tfind -' with no argument selects the previous trace snapshot. So, by giving one `tfind' command, and then simply hitting repeatedly you can examine all the trace snapshots in order. Or, by saying `tfind -' and then hitting repeatedly you can examine the snapshots in reverse order. The `tfind line' command with no argument selects the snapshot for the next source line executed. The `tfind pc' command with no argument selects the next snapshot with the same program counter (PC) as the current frame. The `tfind tracepoint' command with no argument selects the next trace snapshot collected by the same tracepoint as the current one. In addition to letting you scan through the trace buffer manually, these commands make it easy to construct GDB scripts that scan through the trace buffer and print out whatever collected data you are interested in. Thus, if we want to examine the PC, FP, and SP registers from each trace frame in the buffer, we can say this: (gdb) tfind start (gdb) while ($trace_frame != -1) > printf "Frame %d, PC = %08X, SP = %08X, FP = %08X\n", \ $trace_frame, $pc, $sp, $fp > tfind > end Frame 0, PC = 0020DC64, SP = 0030BF3C, FP = 0030BF44 Frame 1, PC = 0020DC6C, SP = 0030BF38, FP = 0030BF44 Frame 2, PC = 0020DC70, SP = 0030BF34, FP = 0030BF44 Frame 3, PC = 0020DC74, SP = 0030BF30, FP = 0030BF44 Frame 4, PC = 0020DC78, SP = 0030BF2C, FP = 0030BF44 Frame 5, PC = 0020DC7C, SP = 0030BF28, FP = 0030BF44 Frame 6, PC = 0020DC80, SP = 0030BF24, FP = 0030BF44 Frame 7, PC = 0020DC84, SP = 0030BF20, FP = 0030BF44 Frame 8, PC = 0020DC88, SP = 0030BF1C, FP = 0030BF44 Frame 9, PC = 0020DC8E, SP = 0030BF18, FP = 0030BF44 Frame 10, PC = 00203F6C, SP = 0030BE3C, FP = 0030BF14 Or, if we want to examine the variable `X' at each source line in the buffer: (gdb) tfind start (gdb) while ($trace_frame != -1) > printf "Frame %d, X == %d\n", $trace_frame, X > tfind line > end Frame 0, X = 1 Frame 7, X = 2 Frame 13, X = 255  File: gdb.info, Node: tdump, Next: save tracepoints, Prev: tfind, Up: Analyze Collected Data 13.2.2 `tdump' -------------- This command takes no arguments. It prints all the data collected at the current trace snapshot. (gdb) trace 444 (gdb) actions Enter actions for tracepoint #2, one per line: > collect $regs, $locals, $args, gdb_long_test > end (gdb) tstart (gdb) tfind line 444 #0 gdb_test (p1=0x11, p2=0x22, p3=0x33, p4=0x44, p5=0x55, p6=0x66) at gdb_test.c:444 444 printp( "%s: arguments = 0x%X 0x%X 0x%X 0x%X 0x%X 0x%X\n", ) (gdb) tdump Data collected at tracepoint 2, trace frame 1: d0 0xc4aa0085 -995491707 d1 0x18 24 d2 0x80 128 d3 0x33 51 d4 0x71aea3d 119204413 d5 0x22 34 d6 0xe0 224 d7 0x380035 3670069 a0 0x19e24a 1696330 a1 0x3000668 50333288 a2 0x100 256 a3 0x322000 3284992 a4 0x3000698 50333336 a5 0x1ad3cc 1758156 fp 0x30bf3c 0x30bf3c sp 0x30bf34 0x30bf34 ps 0x0 0 pc 0x20b2c8 0x20b2c8 fpcontrol 0x0 0 fpstatus 0x0 0 fpiaddr 0x0 0 p = 0x20e5b4 "gdb-test" p1 = (void *) 0x11 p2 = (void *) 0x22 p3 = (void *) 0x33 p4 = (void *) 0x44 p5 = (void *) 0x55 p6 = (void *) 0x66 gdb_long_test = 17 '\021' (gdb) `tdump' works by scanning the tracepoint's current collection actions and printing the value of each expression listed. So `tdump' can fail, if after a run, you change the tracepoint's actions to mention variables that were not collected during the run. Also, for tracepoints with `while-stepping' loops, `tdump' uses the collected value of `$pc' to distinguish between trace frames that were collected at the tracepoint hit, and frames that were collected while stepping. This allows it to correctly choose whether to display the basic list of collections, or the collections from the body of the while-stepping loop. However, if `$pc' was not collected, then `tdump' will always attempt to dump using the basic collection list, and may fail if a while-stepping frame does not include all the same data that is collected at the tracepoint hit.  File: gdb.info, Node: save tracepoints, Prev: tdump, Up: Analyze Collected Data 13.2.3 `save tracepoints FILENAME' ---------------------------------- This command saves all current tracepoint definitions together with their actions and passcounts, into a file `FILENAME' suitable for use in a later debugging session. To read the saved tracepoint definitions, use the `source' command (*note Command Files::). The `save-tracepoints' command is a deprecated alias for `save tracepoints'  File: gdb.info, Node: Tracepoint Variables, Next: Trace Files, Prev: Analyze Collected Data, Up: Tracepoints 13.3 Convenience Variables for Tracepoints ========================================== `(int) $trace_frame' The current trace snapshot (a.k.a. "frame") number, or -1 if no snapshot is selected. `(int) $tracepoint' The tracepoint for the current trace snapshot. `(int) $trace_line' The line number for the current trace snapshot. `(char []) $trace_file' The source file for the current trace snapshot. `(char []) $trace_func' The name of the function containing `$tracepoint'. Note: `$trace_file' is not suitable for use in `printf', use `output' instead. Here's a simple example of using these convenience variables for stepping through all the trace snapshots and printing some of their data. Note that these are not the same as trace state variables, which are managed by the target. (gdb) tfind start (gdb) while $trace_frame != -1 > output $trace_file > printf ", line %d (tracepoint #%d)\n", $trace_line, $tracepoint > tfind > end  File: gdb.info, Node: Trace Files, Prev: Tracepoint Variables, Up: Tracepoints 13.4 Using Trace Files ====================== In some situations, the target running a trace experiment may no longer be available; perhaps it crashed, or the hardware was needed for a different activity. To handle these cases, you can arrange to dump the trace data into a file, and later use that file as a source of trace data, via the `target tfile' command. `tsave [ -r ] FILENAME' `tsave [-ctf] DIRNAME' Save the trace data to FILENAME. By default, this command assumes that FILENAME refers to the host filesystem, so if necessary GDB will copy raw trace data up from the target and then save it. If the target supports it, you can also supply the optional argument `-r' ("remote") to direct the target to save the data directly into FILENAME in its own filesystem, which may be more efficient if the trace buffer is very large. (Note, however, that `target tfile' can only read from files accessible to the host.) By default, this command will save trace frame in tfile format. You can supply the optional argument `-ctf' to save data in CTF format. The "Common Trace Format" (CTF) is proposed as a trace format that can be shared by multiple debugging and tracing tools. Please go to to get more information. `target tfile FILENAME' `target ctf DIRNAME' Use the file named FILENAME or directory named DIRNAME as a source of trace data. Commands that examine data work as they do with a live target, but it is not possible to run any new trace experiments. `tstatus' will report the state of the trace run at the moment the data was saved, as well as the current trace frame you are examining. Both FILENAME and DIRNAME must be on a filesystem accessible to the host. (gdb) target ctf ctf.ctf (gdb) tfind Found trace frame 0, tracepoint 2 39 ++a; /* set tracepoint 1 here */ (gdb) tdump Data collected at tracepoint 2, trace frame 0: i = 0 a = 0 b = 1 '\001' c = {"123", "456", "789", "123", "456", "789"} d = {{{a = 1, b = 2}, {a = 3, b = 4}}, {{a = 5, b = 6}, {a = 7, b = 8}}} (gdb) p b $1 = 1  File: gdb.info, Node: Overlays, Next: Languages, Prev: Tracepoints, Up: Top 14 Debugging Programs That Use Overlays *************************************** If your program is too large to fit completely in your target system's memory, you can sometimes use "overlays" to work around this problem. GDB provides some support for debugging programs that use overlays. * Menu: * How Overlays Work:: A general explanation of overlays. * Overlay Commands:: Managing overlays in GDB. * Automatic Overlay Debugging:: GDB can find out which overlays are mapped by asking the inferior. * Overlay Sample Program:: A sample program using overlays.  File: gdb.info, Node: How Overlays Work, Next: Overlay Commands, Up: Overlays 14.1 How Overlays Work ====================== Suppose you have a computer whose instruction address space is only 64 kilobytes long, but which has much more memory which can be accessed by other means: special instructions, segment registers, or memory management hardware, for example. Suppose further that you want to adapt a program which is larger than 64 kilobytes to run on this system. One solution is to identify modules of your program which are relatively independent, and need not call each other directly; call these modules "overlays". Separate the overlays from the main program, and place their machine code in the larger memory. Place your main program in instruction memory, but leave at least enough space there to hold the largest overlay as well. Now, to call a function located in an overlay, you must first copy that overlay's machine code from the large memory into the space set aside for it in the instruction memory, and then jump to its entry point there. Data Instruction Larger Address Space Address Space Address Space +-----------+ +-----------+ +-----------+ | | | | | | +-----------+ +-----------+ +-----------+<-- overlay 1 | program | | main | .----| overlay 1 | load address | variables | | program | | +-----------+ | and heap | | | | | | +-----------+ | | | +-----------+<-- overlay 2 | | +-----------+ | | | load address +-----------+ | | | .-| overlay 2 | | | | | | | mapped --->+-----------+ | | +-----------+ address | | | | | | | overlay | <-' | | | | area | <---' +-----------+<-- overlay 3 | | <---. | | load address +-----------+ `--| overlay 3 | | | | | +-----------+ | | +-----------+ | | +-----------+ A code overlay The diagram (*note A code overlay::) shows a system with separate data and instruction address spaces. To map an overlay, the program copies its code from the larger address space to the instruction address space. Since the overlays shown here all use the same mapped address, only one may be mapped at a time. For a system with a single address space for data and instructions, the diagram would be similar, except that the program variables and heap would share an address space with the main program and the overlay area. An overlay loaded into instruction memory and ready for use is called a "mapped" overlay; its "mapped address" is its address in the instruction memory. An overlay not present (or only partially present) in instruction memory is called "unmapped"; its "load address" is its address in the larger memory. The mapped address is also called the "virtual memory address", or "VMA"; the load address is also called the "load memory address", or "LMA". Unfortunately, overlays are not a completely transparent way to adapt a program to limited instruction memory. They introduce a new set of global constraints you must keep in mind as you design your program: * Before calling or returning to a function in an overlay, your program must make sure that overlay is actually mapped. Otherwise, the call or return will transfer control to the right address, but in the wrong overlay, and your program will probably crash. * If the process of mapping an overlay is expensive on your system, you will need to choose your overlays carefully to minimize their effect on your program's performance. * The executable file you load onto your system must contain each overlay's instructions, appearing at the overlay's load address, not its mapped address. However, each overlay's instructions must be relocated and its symbols defined as if the overlay were at its mapped address. You can use GNU linker scripts to specify different load and relocation addresses for pieces of your program; see *Note Overlay Description: (ld.info)Overlay Description. * The procedure for loading executable files onto your system must be able to load their contents into the larger address space as well as the instruction and data spaces. The overlay system described above is rather simple, and could be improved in many ways: * If your system has suitable bank switch registers or memory management hardware, you could use those facilities to make an overlay's load area contents simply appear at their mapped address in instruction space. This would probably be faster than copying the overlay to its mapped area in the usual way. * If your overlays are small enough, you could set aside more than one overlay area, and have more than one overlay mapped at a time. * You can use overlays to manage data, as well as instructions. In general, data overlays are even less transparent to your design than code overlays: whereas code overlays only require care when you call or return to functions, data overlays require care every time you access the data. Also, if you change the contents of a data overlay, you must copy its contents back out to its load address before you can copy a different data overlay into the same mapped area.  File: gdb.info, Node: Overlay Commands, Next: Automatic Overlay Debugging, Prev: How Overlays Work, Up: Overlays 14.2 Overlay Commands ===================== To use GDB's overlay support, each overlay in your program must correspond to a separate section of the executable file. The section's virtual memory address and load memory address must be the overlay's mapped and load addresses. Identifying overlays with sections allows GDB to determine the appropriate address of a function or variable, depending on whether the overlay is mapped or not. GDB's overlay commands all start with the word `overlay'; you can abbreviate this as `ov' or `ovly'. The commands are: `overlay off' Disable GDB's overlay support. When overlay support is disabled, GDB assumes that all functions and variables are always present at their mapped addresses. By default, GDB's overlay support is disabled. `overlay manual' Enable "manual" overlay debugging. In this mode, GDB relies on you to tell it which overlays are mapped, and which are not, using the `overlay map-overlay' and `overlay unmap-overlay' commands described below. `overlay map-overlay OVERLAY' `overlay map OVERLAY' Tell GDB that OVERLAY is now mapped; OVERLAY must be the name of the object file section containing the overlay. When an overlay is mapped, GDB assumes it can find the overlay's functions and variables at their mapped addresses. GDB assumes that any other overlays whose mapped ranges overlap that of OVERLAY are now unmapped. `overlay unmap-overlay OVERLAY' `overlay unmap OVERLAY' Tell GDB that OVERLAY is no longer mapped; OVERLAY must be the name of the object file section containing the overlay. When an overlay is unmapped, GDB assumes it can find the overlay's functions and variables at their load addresses. `overlay auto' Enable "automatic" overlay debugging. In this mode, GDB consults a data structure the overlay manager maintains in the inferior to see which overlays are mapped. For details, see *Note Automatic Overlay Debugging::. `overlay load-target' `overlay load' Re-read the overlay table from the inferior. Normally, GDB re-reads the table GDB automatically each time the inferior stops, so this command should only be necessary if you have changed the overlay mapping yourself using GDB. This command is only useful when using automatic overlay debugging. `overlay list-overlays' `overlay list' Display a list of the overlays currently mapped, along with their mapped addresses, load addresses, and sizes. Normally, when GDB prints a code address, it includes the name of the function the address falls in: (gdb) print main $3 = {int ()} 0x11a0
When overlay debugging is enabled, GDB recognizes code in unmapped overlays, and prints the names of unmapped functions with asterisks around them. For example, if `foo' is a function in an unmapped overlay, GDB prints it this way: (gdb) overlay list No sections are mapped. (gdb) print foo $5 = {int (int)} 0x100000 <*foo*> When `foo''s overlay is mapped, GDB prints the function's name normally: (gdb) overlay list Section .ov.foo.text, loaded at 0x100000 - 0x100034, mapped at 0x1016 - 0x104a (gdb) print foo $6 = {int (int)} 0x1016 When overlay debugging is enabled, GDB can find the correct address for functions and variables in an overlay, whether or not the overlay is mapped. This allows most GDB commands, like `break' and `disassemble', to work normally, even on unmapped code. However, GDB's breakpoint support has some limitations: * You can set breakpoints in functions in unmapped overlays, as long as GDB can write to the overlay at its load address. * GDB can not set hardware or simulator-based breakpoints in unmapped overlays. However, if you set a breakpoint at the end of your overlay manager (and tell GDB which overlays are now mapped, if you are using manual overlay management), GDB will re-set its breakpoints properly.  File: gdb.info, Node: Automatic Overlay Debugging, Next: Overlay Sample Program, Prev: Overlay Commands, Up: Overlays 14.3 Automatic Overlay Debugging ================================ GDB can automatically track which overlays are mapped and which are not, given some simple co-operation from the overlay manager in the inferior. If you enable automatic overlay debugging with the `overlay auto' command (*note Overlay Commands::), GDB looks in the inferior's memory for certain variables describing the current state of the overlays. Here are the variables your overlay manager must define to support GDB's automatic overlay debugging: `_ovly_table': This variable must be an array of the following structures: struct { /* The overlay's mapped address. */ unsigned long vma; /* The size of the overlay, in bytes. */ unsigned long size; /* The overlay's load address. */ unsigned long lma; /* Non-zero if the overlay is currently mapped; zero otherwise. */ unsigned long mapped; } `_novlys': This variable must be a four-byte signed integer, holding the total number of elements in `_ovly_table'. To decide whether a particular overlay is mapped or not, GDB looks for an entry in `_ovly_table' whose `vma' and `lma' members equal the VMA and LMA of the overlay's section in the executable file. When GDB finds a matching entry, it consults the entry's `mapped' member to determine whether the overlay is currently mapped. In addition, your overlay manager may define a function called `_ovly_debug_event'. If this function is defined, GDB will silently set a breakpoint there. If the overlay manager then calls this function whenever it has changed the overlay table, this will enable GDB to accurately keep track of which overlays are in program memory, and update any breakpoints that may be set in overlays. This will allow breakpoints to work even if the overlays are kept in ROM or other non-writable memory while they are not being executed.  File: gdb.info, Node: Overlay Sample Program, Prev: Automatic Overlay Debugging, Up: Overlays 14.4 Overlay Sample Program =========================== When linking a program which uses overlays, you must place the overlays at their load addresses, while relocating them to run at their mapped addresses. To do this, you must write a linker script (*note Overlay Description: (ld.info)Overlay Description.). Unfortunately, since linker scripts are specific to a particular host system, target architecture, and target memory layout, this manual cannot provide portable sample code demonstrating GDB's overlay support. However, the GDB source distribution does contain an overlaid program, with linker scripts for a few systems, as part of its test suite. The program consists of the following files from `gdb/testsuite/gdb.base': `overlays.c' The main program file. `ovlymgr.c' A simple overlay manager, used by `overlays.c'. `foo.c' `bar.c' `baz.c' `grbx.c' Overlay modules, loaded and used by `overlays.c'. `d10v.ld' `m32r.ld' Linker scripts for linking the test program on the `d10v-elf' and `m32r-elf' targets. You can build the test program using the `d10v-elf' GCC cross-compiler like this: $ d10v-elf-gcc -g -c overlays.c $ d10v-elf-gcc -g -c ovlymgr.c $ d10v-elf-gcc -g -c foo.c $ d10v-elf-gcc -g -c bar.c $ d10v-elf-gcc -g -c baz.c $ d10v-elf-gcc -g -c grbx.c $ d10v-elf-gcc -g overlays.o ovlymgr.o foo.o bar.o \ baz.o grbx.o -Wl,-Td10v.ld -o overlays The build process is identical for any other architecture, except that you must substitute the appropriate compiler and linker script for the target system for `d10v-elf-gcc' and `d10v.ld'.  File: gdb.info, Node: Languages, Next: Symbols, Prev: Overlays, Up: Top 15 Using GDB with Different Languages ************************************* Although programming languages generally have common aspects, they are rarely expressed in the same manner. For instance, in ANSI C, dereferencing a pointer `p' is accomplished by `*p', but in Modula-2, it is accomplished by `p^'. Values can also be represented (and displayed) differently. Hex numbers in C appear as `0x1ae', while in Modula-2 they appear as `1AEH'. Language-specific information is built into GDB for some languages, allowing you to express operations like the above in your program's native language, and allowing GDB to output values in a manner consistent with the syntax of your program's native language. The language you use to build expressions is called the "working language". * Menu: * Setting:: Switching between source languages * Show:: Displaying the language * Checks:: Type and range checks * Supported Languages:: Supported languages * Unsupported Languages:: Unsupported languages  File: gdb.info, Node: Setting, Next: Show, Up: Languages 15.1 Switching Between Source Languages ======================================= There are two ways to control the working language--either have GDB set it automatically, or select it manually yourself. You can use the `set language' command for either purpose. On startup, GDB defaults to setting the language automatically. The working language is used to determine how expressions you type are interpreted, how values are printed, etc. In addition to the working language, every source file that GDB knows about has its own working language. For some object file formats, the compiler might indicate which language a particular source file is in. However, most of the time GDB infers the language from the name of the file. The language of a source file controls whether C++ names are demangled--this way `backtrace' can show each frame appropriately for its own language. There is no way to set the language of a source file from within GDB, but you can set the language associated with a filename extension. *Note Displaying the Language: Show. This is most commonly a problem when you use a program, such as `cfront' or `f2c', that generates C but is written in another language. In that case, make the program use `#line' directives in its C output; that way GDB will know the correct language of the source code of the original program, and will display that source code, not the generated C code. * Menu: * Filenames:: Filename extensions and languages. * Manually:: Setting the working language manually * Automatically:: Having GDB infer the source language  File: gdb.info, Node: Filenames, Next: Manually, Up: Setting 15.1.1 List of Filename Extensions and Languages ------------------------------------------------ If a source file name ends in one of the following extensions, then GDB infers that its language is the one indicated. `.ada' `.ads' `.adb' `.a' Ada source file. `.c' C source file `.C' `.cc' `.cp' `.cpp' `.cxx' `.c++' C++ source file `.d' D source file `.m' Objective-C source file `.f' `.F' Fortran source file `.mod' Modula-2 source file `.s' `.S' Assembler source file. This actually behaves almost like C, but GDB does not skip over function prologues when stepping. In addition, you may set the language associated with a filename extension. *Note Displaying the Language: Show.  File: gdb.info, Node: Manually, Next: Automatically, Prev: Filenames, Up: Setting 15.1.2 Setting the Working Language ----------------------------------- If you allow GDB to set the language automatically, expressions are interpreted the same way in your debugging session and your program. If you wish, you may set the language manually. To do this, issue the command `set language LANG', where LANG is the name of a language, such as `c' or `modula-2'. For a list of the supported languages, type `set language'. Setting the language manually prevents GDB from updating the working language automatically. This can lead to confusion if you try to debug a program when the working language is not the same as the source language, when an expression is acceptable to both languages--but means different things. For instance, if the current source file were written in C, and GDB was parsing Modula-2, a command such as: print a = b + c might not have the effect you intended. In C, this means to add `b' and `c' and place the result in `a'. The result printed would be the value of `a'. In Modula-2, this means to compare `a' to the result of `b+c', yielding a `BOOLEAN' value.  File: gdb.info, Node: Automatically, Prev: Manually, Up: Setting 15.1.3 Having GDB Infer the Source Language ------------------------------------------- To have GDB set the working language automatically, use `set language local' or `set language auto'. GDB then infers the working language. That is, when your program stops in a frame (usually by encountering a breakpoint), GDB sets the working language to the language recorded for the function in that frame. If the language for a frame is unknown (that is, if the function or block corresponding to the frame was defined in a source file that does not have a recognized extension), the current working language is not changed, and GDB issues a warning. This may not seem necessary for most programs, which are written entirely in one source language. However, program modules and libraries written in one source language can be used by a main program written in a different source language. Using `set language auto' in this case frees you from having to set the working language manually.  File: gdb.info, Node: Show, Next: Checks, Prev: Setting, Up: Languages 15.2 Displaying the Language ============================ The following commands help you find out which language is the working language, and also what language source files were written in. `show language' Display the current working language. This is the language you can use with commands such as `print' to build and compute expressions that may involve variables in your program. `info frame' Display the source language for this frame. This language becomes the working language if you use an identifier from this frame. *Note Information about a Frame: Frame Info, to identify the other information listed here. `info source' Display the source language of this source file. *Note Examining the Symbol Table: Symbols, to identify the other information listed here. In unusual circumstances, you may have source files with extensions not in the standard list. You can then set the extension associated with a language explicitly: `set extension-language EXT LANGUAGE' Tell GDB that source files with extension EXT are to be assumed as written in the source language LANGUAGE. `info extensions' List all the filename extensions and the associated languages.  File: gdb.info, Node: Checks, Next: Supported Languages, Prev: Show, Up: Languages 15.3 Type and Range Checking ============================ Some languages are designed to guard you against making seemingly common errors through a series of compile- and run-time checks. These include checking the type of arguments to functions and operators and making sure mathematical overflows are caught at run time. Checks such as these help to ensure a program's correctness once it has been compiled by eliminating type mismatches and providing active checks for range errors when your program is running. By default GDB checks for these errors according to the rules of the current source language. Although GDB does not check the statements in your program, it can check expressions entered directly into GDB for evaluation via the `print' command, for example. * Menu: * Type Checking:: An overview of type checking * Range Checking:: An overview of range checking  File: gdb.info, Node: Type Checking, Next: Range Checking, Up: Checks 15.3.1 An Overview of Type Checking ----------------------------------- Some languages, such as C and C++, are strongly typed, meaning that the arguments to operators and functions have to be of the correct type, otherwise an error occurs. These checks prevent type mismatch errors from ever causing any run-time problems. For example, int klass::my_method(char *b) { return b ? 1 : 2; } (gdb) print obj.my_method (0) $1 = 2 but (gdb) print obj.my_method (0x1234) Cannot resolve method klass::my_method to any overloaded instance The second example fails because in C++ the integer constant `0x1234' is not type-compatible with the pointer parameter type. For the expressions you use in GDB commands, you can tell GDB to not enforce strict type checking or to treat any mismatches as errors and abandon the expression; When type checking is disabled, GDB successfully evaluates expressions like the second example above. Even if type checking is off, there may be other reasons related to type that prevent GDB from evaluating an expression. For instance, GDB does not know how to add an `int' and a `struct foo'. These particular type errors have nothing to do with the language in use and usually arise from expressions which make little sense to evaluate anyway. GDB provides some additional commands for controlling type checking: `set check type on' `set check type off' Set strict type checking on or off. If any type mismatches occur in evaluating an expression while type checking is on, GDB prints a message and aborts evaluation of the expression. `show check type' Show the current setting of type checking and whether GDB is enforcing strict type checking rules.  File: gdb.info, Node: Range Checking, Prev: Type Checking, Up: Checks 15.3.2 An Overview of Range Checking ------------------------------------ In some languages (such as Modula-2), it is an error to exceed the bounds of a type; this is enforced with run-time checks. Such range checking is meant to ensure program correctness by making sure computations do not overflow, or indices on an array element access do not exceed the bounds of the array. For expressions you use in GDB commands, you can tell GDB to treat range errors in one of three ways: ignore them, always treat them as errors and abandon the expression, or issue warnings but evaluate the expression anyway. A range error can result from numerical overflow, from exceeding an array index bound, or when you type a constant that is not a member of any type. Some languages, however, do not treat overflows as an error. In many implementations of C, mathematical overflow causes the result to "wrap around" to lower values--for example, if M is the largest integer value, and S is the smallest, then M + 1 => S This, too, is specific to individual languages, and in some cases specific to individual compilers or machines. *Note Supported Languages: Supported Languages, for further details on specific languages. GDB provides some additional commands for controlling the range checker: `set check range auto' Set range checking on or off based on the current working language. *Note Supported Languages: Supported Languages, for the default settings for each language. `set check range on' `set check range off' Set range checking on or off, overriding the default setting for the current working language. A warning is issued if the setting does not match the language default. If a range error occurs and range checking is on, then a message is printed and evaluation of the expression is aborted. `set check range warn' Output messages when the GDB range checker detects a range error, but attempt to evaluate the expression anyway. Evaluating the expression may still be impossible for other reasons, such as accessing memory that the process does not own (a typical example from many Unix systems). `show check range' Show the current setting of the range checker, and whether or not it is being set automatically by GDB.  File: gdb.info, Node: Supported Languages, Next: Unsupported Languages, Prev: Checks, Up: Languages 15.4 Supported Languages ======================== GDB supports C, C++, D, Go, Objective-C, Fortran, OpenCL C, Pascal, Rust, assembly, Modula-2, and Ada. Some GDB features may be used in expressions regardless of the language you use: the GDB `@@' and `::' operators, and the `{type}addr' construct (*note Expressions: Expressions.) can be used with the constructs of any supported language. The following sections detail to what degree each source language is supported by GDB. These sections are not meant to be language tutorials or references, but serve only as a reference guide to what the GDB expression parser accepts, and what input and output formats should look like for different languages. There are many good books written on each of these languages; please look to these for a language reference or tutorial. * Menu: * C:: C and C++ * D:: D * Go:: Go * Objective-C:: Objective-C * OpenCL C:: OpenCL C * Fortran:: Fortran * Pascal:: Pascal * Rust:: Rust * Modula-2:: Modula-2 * Ada:: Ada  File: gdb.info, Node: C, Next: D, Up: Supported Languages 15.4.1 C and C++ ---------------- Since C and C++ are so closely related, many features of GDB apply to both languages. Whenever this is the case, we discuss those languages together. The C++ debugging facilities are jointly implemented by the C++ compiler and GDB. Therefore, to debug your C++ code effectively, you must compile your C++ programs with a supported C++ compiler, such as GNU `g++', or the HP ANSI C++ compiler (`aCC'). * Menu: * C Operators:: C and C++ operators * C Constants:: C and C++ constants * C Plus Plus Expressions:: C++ expressions * C Defaults:: Default settings for C and C++ * C Checks:: C and C++ type and range checks * Debugging C:: GDB and C * Debugging C Plus Plus:: GDB features for C++ * Decimal Floating Point:: Numbers in Decimal Floating Point format  File: gdb.info, Node: C Operators, Next: C Constants, Up: C 15.4.1.1 C and C++ Operators ............................ Operators must be defined on values of specific types. For instance, `+' is defined on numbers, but not on structures. Operators are often defined on groups of types. For the purposes of C and C++, the following definitions hold: * _Integral types_ include `int' with any of its storage-class specifiers; `char'; `enum'; and, for C++, `bool'. * _Floating-point types_ include `float', `double', and `long double' (if supported by the target platform). * _Pointer types_ include all types defined as `(TYPE *)'. * _Scalar types_ include all of the above. The following operators are supported. They are listed here in order of increasing precedence: `,' The comma or sequencing operator. Expressions in a comma-separated list are evaluated from left to right, with the result of the entire expression being the last expression evaluated. `=' Assignment. The value of an assignment expression is the value assigned. Defined on scalar types. `OP=' Used in an expression of the form `A OP= B', and translated to `A = A OP B'. `OP=' and `=' have the same precedence. The operator OP is any one of the operators `|', `^', `&', `<<', `>>', `+', `-', `*', `/', `%'. `?:' The ternary operator. `A ? B : C' can be thought of as: if A then B else C. The argument A should be of an integral type. `||' Logical OR. Defined on integral types. `&&' Logical AND. Defined on integral types. `|' Bitwise OR. Defined on integral types. `^' Bitwise exclusive-OR. Defined on integral types. `&' Bitwise AND. Defined on integral types. `==, !=' Equality and inequality. Defined on scalar types. The value of these expressions is 0 for false and non-zero for true. `<, >, <=, >=' Less than, greater than, less than or equal, greater than or equal. Defined on scalar types. The value of these expressions is 0 for false and non-zero for true. `<<, >>' left shift, and right shift. Defined on integral types. `@@' The GDB "artificial array" operator (*note Expressions: Expressions.). `+, -' Addition and subtraction. Defined on integral types, floating-point types and pointer types. `*, /, %' Multiplication, division, and modulus. Multiplication and division are defined on integral and floating-point types. Modulus is defined on integral types. `++, --' Increment and decrement. When appearing before a variable, the operation is performed before the variable is used in an expression; when appearing after it, the variable's value is used before the operation takes place. `*' Pointer dereferencing. Defined on pointer types. Same precedence as `++'. `&' Address operator. Defined on variables. Same precedence as `++'. For debugging C++, GDB implements a use of `&' beyond what is allowed in the C++ language itself: you can use `&(&REF)' to examine the address where a C++ reference variable (declared with `&REF') is stored. `-' Negative. Defined on integral and floating-point types. Same precedence as `++'. `!' Logical negation. Defined on integral types. Same precedence as `++'. `~' Bitwise complement operator. Defined on integral types. Same precedence as `++'. `., ->' Structure member, and pointer-to-structure member. For convenience, GDB regards the two as equivalent, choosing whether to dereference a pointer based on the stored type information. Defined on `struct' and `union' data. `.*, ->*' Dereferences of pointers to members. `[]' Array indexing. `A[I]' is defined as `*(A+I)'. Same precedence as `->'. `()' Function parameter list. Same precedence as `->'. `::' C++ scope resolution operator. Defined on `struct', `union', and `class' types. `::' Doubled colons also represent the GDB scope operator (*note Expressions: Expressions.). Same precedence as `::', above. If an operator is redefined in the user code, GDB usually attempts to invoke the redefined version instead of using the operator's predefined meaning.  File: gdb.info, Node: C Constants, Next: C Plus Plus Expressions, Prev: C Operators, Up: C 15.4.1.2 C and C++ Constants ............................ GDB allows you to express the constants of C and C++ in the following ways: * Integer constants are a sequence of digits. Octal constants are specified by a leading `0' (i.e. zero), and hexadecimal constants by a leading `0x' or `0X'. Constants may also end with a letter `l', specifying that the constant should be treated as a `long' value. * Floating point constants are a sequence of digits, followed by a decimal point, followed by a sequence of digits, and optionally followed by an exponent. An exponent is of the form: `e[[+]|-]NNN', where NNN is another sequence of digits. The `+' is optional for positive exponents. A floating-point constant may also end with a letter `f' or `F', specifying that the constant should be treated as being of the `float' (as opposed to the default `double') type; or with a letter `l' or `L', which specifies a `long double' constant. * Enumerated constants consist of enumerated identifiers, or their integral equivalents. * Character constants are a single character surrounded by single quotes (`''), or a number--the ordinal value of the corresponding character (usually its ASCII value). Within quotes, the single character may be represented by a letter or by "escape sequences", which are of the form `\NNN', where NNN is the octal representation of the character's ordinal value; or of the form `\X', where `X' is a predefined special character--for example, `\n' for newline. Wide character constants can be written by prefixing a character constant with `L', as in C. For example, `L'x'' is the wide form of `x'. The target wide character set is used when computing the value of this constant (*note Character Sets::). * String constants are a sequence of character constants surrounded by double quotes (`"'). Any valid character constant (as described above) may appear. Double quotes within the string must be preceded by a backslash, so for instance `"a\"b'c"' is a string of five characters. Wide string constants can be written by prefixing a string constant with `L', as in C. The target wide character set is used when computing the value of this constant (*note Character Sets::). * Pointer constants are an integral value. You can also write pointers to constants using the C operator `&'. * Array constants are comma-separated lists surrounded by braces `{' and `}'; for example, `{1,2,3}' is a three-element array of integers, `{{1,2}, {3,4}, {5,6}}' is a three-by-two array, and `{&"hi", &"there", &"fred"}' is a three-element array of pointers.  File: gdb.info, Node: C Plus Plus Expressions, Next: C Defaults, Prev: C Constants, Up: C 15.4.1.3 C++ Expressions ........................ GDB expression handling can interpret most C++ expressions. _Warning:_ GDB can only debug C++ code if you use the proper compiler and the proper debug format. Currently, GDB works best when debugging C++ code that is compiled with the most recent version of GCC possible. The DWARF debugging format is preferred; GCC defaults to this on most popular platforms. Other compilers and/or debug formats are likely to work badly or not at all when using GDB to debug C++ code. *Note Compilation::. 1. Member function calls are allowed; you can use expressions like count = aml->GetOriginal(x, y) 2. While a member function is active (in the selected stack frame), your expressions have the same namespace available as the member function; that is, GDB allows implicit references to the class instance pointer `this' following the same rules as C++. `using' declarations in the current scope are also respected by GDB. 3. You can call overloaded functions; GDB resolves the function call to the right definition, with some restrictions. GDB does not perform overload resolution involving user-defined type conversions, calls to constructors, or instantiations of templates that do not exist in the program. It also cannot handle ellipsis argument lists or default arguments. It does perform integral conversions and promotions, floating-point promotions, arithmetic conversions, pointer conversions, conversions of class objects to base classes, and standard conversions such as those of functions or arrays to pointers; it requires an exact match on the number of function arguments. Overload resolution is always performed, unless you have specified `set overload-resolution off'. *Note GDB Features for C++: Debugging C Plus Plus. You must specify `set overload-resolution off' in order to use an explicit function signature to call an overloaded function, as in p 'foo(char,int)'('x', 13) The GDB command-completion facility can simplify this; see *Note Command Completion: Completion. 4. GDB understands variables declared as C++ lvalue or rvalue references; you can use them in expressions just as you do in C++ source--they are automatically dereferenced. In the parameter list shown when GDB displays a frame, the values of reference variables are not displayed (unlike other variables); this avoids clutter, since references are often used for large structures. The _address_ of a reference variable is always shown, unless you have specified `set print address off'. 5. GDB supports the C++ name resolution operator `::'--your expressions can use it just as expressions in your program do. Since one scope may be defined in another, you can use `::' repeatedly if necessary, for example in an expression like `SCOPE1::SCOPE2::NAME'. GDB also allows resolving name scope by reference to source files, in both C and C++ debugging (*note Program Variables: Variables.). 6. GDB performs argument-dependent lookup, following the C++ specification.  File: gdb.info, Node: C Defaults, Next: C Checks, Prev: C Plus Plus Expressions, Up: C 15.4.1.4 C and C++ Defaults ........................... If you allow GDB to set range checking automatically, it defaults to `off' whenever the working language changes to C or C++. This happens regardless of whether you or GDB selects the working language. If you allow GDB to set the language automatically, it recognizes source files whose names end with `.c', `.C', or `.cc', etc, and when GDB enters code compiled from one of these files, it sets the working language to C or C++. *Note Having GDB Infer the Source Language: Automatically, for further details.  File: gdb.info, Node: C Checks, Next: Debugging C, Prev: C Defaults, Up: C 15.4.1.5 C and C++ Type and Range Checks ........................................ By default, when GDB parses C or C++ expressions, strict type checking is used. However, if you turn type checking off, GDB will allow certain non-standard conversions, such as promoting integer constants to pointers. Range checking, if turned on, is done on mathematical operations. Array indices are not checked, since they are often used to index a pointer that is not itself an array.  File: gdb.info, Node: Debugging C, Next: Debugging C Plus Plus, Prev: C Checks, Up: C 15.4.1.6 GDB and C .................. The `set print union' and `show print union' commands apply to the `union' type. When set to `on', any `union' that is inside a `struct' or `class' is also printed. Otherwise, it appears as `{...}'. The `@@' operator aids in the debugging of dynamic arrays, formed with pointers and a memory allocation function. *Note Expressions: Expressions.  File: gdb.info, Node: Debugging C Plus Plus, Next: Decimal Floating Point, Prev: Debugging C, Up: C 15.4.1.7 GDB Features for C++ ............................. Some GDB commands are particularly useful with C++, and some are designed specifically for use with C++. Here is a summary: `breakpoint menus' When you want a breakpoint in a function whose name is overloaded, GDB has the capability to display a menu of possible breakpoint locations to help you specify which function definition you want. *Note Ambiguous Expressions: Ambiguous Expressions. `rbreak REGEX' Setting breakpoints using regular expressions is helpful for setting breakpoints on overloaded functions that are not members of any special classes. *Note Setting Breakpoints: Set Breaks. `catch throw' `catch rethrow' `catch catch' Debug C++ exception handling using these commands. *Note Setting Catchpoints: Set Catchpoints. `ptype TYPENAME' Print inheritance relationships as well as other information for type TYPENAME. *Note Examining the Symbol Table: Symbols. `info vtbl EXPRESSION.' The `info vtbl' command can be used to display the virtual method tables of the object computed by EXPRESSION. This shows one entry per virtual table; there may be multiple virtual tables when multiple inheritance is in use. `demangle NAME' Demangle NAME. *Note Symbols::, for a more complete description of the `demangle' command. `set print demangle' `show print demangle' `set print asm-demangle' `show print asm-demangle' Control whether C++ symbols display in their source form, both when displaying code as C++ source and when displaying disassemblies. *Note Print Settings: Print Settings. `set print object' `show print object' Choose whether to print derived (actual) or declared types of objects. *Note Print Settings: Print Settings. `set print vtbl' `show print vtbl' Control the format for printing virtual function tables. *Note Print Settings: Print Settings. (The `vtbl' commands do not work on programs compiled with the HP ANSI C++ compiler (`aCC').) `set overload-resolution on' Enable overload resolution for C++ expression evaluation. The default is on. For overloaded functions, GDB evaluates the arguments and searches for a function whose signature matches the argument types, using the standard C++ conversion rules (see *Note C++ Expressions: C Plus Plus Expressions, for details). If it cannot find a match, it emits a message. `set overload-resolution off' Disable overload resolution for C++ expression evaluation. For overloaded functions that are not class member functions, GDB chooses the first function of the specified name that it finds in the symbol table, whether or not its arguments are of the correct type. For overloaded functions that are class member functions, GDB searches for a function whose signature _exactly_ matches the argument types. `show overload-resolution' Show the current setting of overload resolution. `Overloaded symbol names' You can specify a particular definition of an overloaded symbol, using the same notation that is used to declare such symbols in C++: type `SYMBOL(TYPES)' rather than just SYMBOL. You can also use the GDB command-line word completion facilities to list the available choices, or to finish the type list for you. *Note Command Completion: Completion, for details on how to do this. `Breakpoints in template functions' Similar to how overloaded symbols are handled, GDB will ignore template parameter lists when it encounters a symbol which includes a C++ template. This permits setting breakpoints on families of template functions or functions whose parameters include template types. The `-qualified' flag may be used to override this behavior, causing GDB to search for a specific function or type. The GDB command-line word completion facility also understands template parameters and may be used to list available choices or finish template parameter lists for you. *Note Command Completion: Completion, for details on how to do this. `Breakpoints in functions with ABI tags' The GNU C++ compiler introduced the notion of ABI "tags", which correspond to changes in the ABI of a type, function, or variable that would not otherwise be reflected in a mangled name. See `https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/' for more detail. The ABI tags are visible in C++ demangled names. For example, a function that returns a std::string: std::string function(int); when compiled for the C++11 ABI is marked with the `cxx11' ABI tag, and GDB displays the symbol like this: function[abi:cxx11](int) You can set a breakpoint on such functions simply as if they had no tag. For example: (gdb) b function(int) Breakpoint 2 at 0x40060d: file main.cc, line 10. (gdb) info breakpoints Num Type Disp Enb Address What 1 breakpoint keep y 0x0040060d in function[abi:cxx11](int) at main.cc:10 On the rare occasion you need to disambiguate between different ABI tags, you can do so by simply including the ABI tag in the function name, like: (gdb) b ambiguous[abi:other_tag](int)  File: gdb.info, Node: Decimal Floating Point, Prev: Debugging C Plus Plus, Up: C 15.4.1.8 Decimal Floating Point format ...................................... GDB can examine, set and perform computations with numbers in decimal floating point format, which in the C language correspond to the `_Decimal32', `_Decimal64' and `_Decimal128' types as specified by the extension to support decimal floating-point arithmetic. There are two encodings in use, depending on the architecture: BID (Binary Integer Decimal) for x86 and x86-64, and DPD (Densely Packed Decimal) for PowerPC and S/390. GDB will use the appropriate encoding for the configured target. Because of a limitation in `libdecnumber', the library used by GDB to manipulate decimal floating point numbers, it is not possible to convert (using a cast, for example) integers wider than 32-bit to decimal float. In addition, in order to imitate GDB's behaviour with binary floating point computations, error checking in decimal float operations ignores underflow, overflow and divide by zero exceptions. In the PowerPC architecture, GDB provides a set of pseudo-registers to inspect `_Decimal128' values stored in floating point registers. See *Note PowerPC: PowerPC. for more details.  File: gdb.info, Node: D, Next: Go, Prev: C, Up: Supported Languages 15.4.2 D -------- GDB can be used to debug programs written in D and compiled with GDC, LDC or DMD compilers. Currently GDB supports only one D specific feature -- dynamic arrays.  File: gdb.info, Node: Go, Next: Objective-C, Prev: D, Up: Supported Languages 15.4.3 Go --------- GDB can be used to debug programs written in Go and compiled with `gccgo' or `6g' compilers. Here is a summary of the Go-specific features and restrictions: `The current Go package' The name of the current package does not need to be specified when specifying global variables and functions. For example, given the program: package main var myglob = "Shall we?" func main () { // ... } When stopped inside `main' either of these work: (gdb) p myglob (gdb) p main.myglob `Builtin Go types' The `string' type is recognized by GDB and is printed as a string. `Builtin Go functions' The GDB expression parser recognizes the `unsafe.Sizeof' function and handles it internally. `Restrictions on Go expressions' All Go operators are supported except `&^'. The Go `_' "blank identifier" is not supported. Automatic dereferencing of pointers is not supported.  File: gdb.info, Node: Objective-C, Next: OpenCL C, Prev: Go, Up: Supported Languages 15.4.4 Objective-C ------------------ This section provides information about some commands and command options that are useful for debugging Objective-C code. See also *Note info classes: Symbols, and *Note info selectors: Symbols, for a few more commands specific to Objective-C support. * Menu: * Method Names in Commands:: * The Print Command with Objective-C::  File: gdb.info, Node: Method Names in Commands, Next: The Print Command with Objective-C, Up: Objective-C 15.4.4.1 Method Names in Commands ................................. The following commands have been extended to accept Objective-C method names as line specifications: * `clear' * `break' * `info line' * `jump' * `list' A fully qualified Objective-C method name is specified as -[CLASS METHODNAME] where the minus sign is used to indicate an instance method and a plus sign (not shown) is used to indicate a class method. The class name CLASS and method name METHODNAME are enclosed in brackets, similar to the way messages are specified in Objective-C source code. For example, to set a breakpoint at the `create' instance method of class `Fruit' in the program currently being debugged, enter: break -[Fruit create] To list ten program lines around the `initialize' class method, enter: list +[NSText initialize] In the current version of GDB, the plus or minus sign is required. In future versions of GDB, the plus or minus sign will be optional, but you can use it to narrow the search. It is also possible to specify just a method name: break create You must specify the complete method name, including any colons. If your program's source files contain more than one `create' method, you'll be presented with a numbered list of classes that implement that method. Indicate your choice by number, or type `0' to exit if none apply. As another example, to clear a breakpoint established at the `makeKeyAndOrderFront:' method of the `NSWindow' class, enter: clear -[NSWindow makeKeyAndOrderFront:]  File: gdb.info, Node: The Print Command with Objective-C, Prev: Method Names in Commands, Up: Objective-C 15.4.4.2 The Print Command With Objective-C ........................................... The print command has also been extended to accept methods. For example: print -[OBJECT hash] will tell GDB to send the `hash' message to OBJECT and print the result. Also, an additional command has been added, `print-object' or `po' for short, which is meant to print the description of an object. However, this command may only work with certain Objective-C libraries that have a particular hook function, `_NSPrintForDebugger', defined.  File: gdb.info, Node: OpenCL C, Next: Fortran, Prev: Objective-C, Up: Supported Languages 15.4.5 OpenCL C --------------- This section provides information about GDBs OpenCL C support. * Menu: * OpenCL C Datatypes:: * OpenCL C Expressions:: * OpenCL C Operators::  File: gdb.info, Node: OpenCL C Datatypes, Next: OpenCL C Expressions, Up: OpenCL C 15.4.5.1 OpenCL C Datatypes ........................... GDB supports the builtin scalar and vector datatypes specified by OpenCL 1.1. In addition the half- and double-precision floating point data types of the `cl_khr_fp16' and `cl_khr_fp64' OpenCL extensions are also known to GDB.  File: gdb.info, Node: OpenCL C Expressions, Next: OpenCL C Operators, Prev: OpenCL C Datatypes, Up: OpenCL C 15.4.5.2 OpenCL C Expressions ............................. GDB supports accesses to vector components including the access as lvalue where possible. Since OpenCL C is based on C99 most C expressions supported by GDB can be used as well.  File: gdb.info, Node: OpenCL C Operators, Prev: OpenCL C Expressions, Up: OpenCL C 15.4.5.3 OpenCL C Operators ........................... GDB supports the operators specified by OpenCL 1.1 for scalar and vector data types.  File: gdb.info, Node: Fortran, Next: Pascal, Prev: OpenCL C, Up: Supported Languages 15.4.6 Fortran -------------- GDB can be used to debug programs written in Fortran. Note, that not all Fortran language features are available yet. Some Fortran compilers (GNU Fortran 77 and Fortran 95 compilers among them) append an underscore to the names of variables and functions. When you debug programs compiled by those compilers, you will need to refer to variables and functions with a trailing underscore. Fortran symbols are usually case-insensitive, so GDB by default uses case-insensitive matching for Fortran symbols. You can change that with the `set case-insensitive' command, see *Note Symbols::, for the details. * Menu: * Fortran Types:: Fortran builtin types * Fortran Operators:: Fortran operators and expressions * Fortran Intrinsics:: Fortran intrinsic functions * Special Fortran Commands:: Special GDB commands for Fortran  File: gdb.info, Node: Fortran Types, Next: Fortran Operators, Up: Fortran 15.4.6.1 Fortran Types ...................... In Fortran the primitive data-types have an associated `KIND' type parameter, written as `TYPE*KINDPARAM', `TYPE*KINDPARAM', or in the GDB-only dialect `TYPE_KINDPARAM'. A concrete example would be ``Real*4'', ``Real(kind=4)'', and ``Real_4''. The kind of a type can be retrieved by using the intrinsic function `KIND', see *Note Fortran Intrinsics::. Generally, the actual implementation of the `KIND' type parameter is compiler specific. In GDB the kind parameter is implemented in accordance with its use in the GNU `gfortran' compiler. Here, the kind parameter for a given TYPE specifies its size in memory -- a Fortran `Integer*4' or `Integer(kind=4)' would be an integer type occupying 4 bytes of memory. An exception to this rule is the `Complex' type for which the kind of the type does not specify its entire size, but the size of each of the two `Real''s it is composed of. A `Complex*4' would thus consist of two `Real*4's and occupy 8 bytes of memory. For every type there is also a default kind associated with it, e.g. `Integer' in GDB will internally be an `Integer*4' (see the table below for default types). The default types are the same as in GNU compilers but note, that the GNU default types can actually be changed by compiler flags such as `-fdefault-integer-8' and `-fdefault-real-8'. Not every kind parameter is valid for every type and in GDB the following type kinds are available. `Integer' `Integer*1', `Integer*2', `Integer*4', `Integer*8', and `Integer' = `Integer*4'. `Logical' `Logical*1', `Logical*2', `Logical*4', `Logical*8', and `Logical' = `Logical*4'. `Real' `Real*4', `Real*8', `Real*16', and `Real' = `Real*4'. `Complex' `Complex*4', `Complex*8', `Complex*16', and `Complex' = `Complex*4'.  File: gdb.info, Node: Fortran Operators, Next: Fortran Intrinsics, Prev: Fortran Types, Up: Fortran 15.4.6.2 Fortran Operators and Expressions .......................................... Operators must be defined on values of specific types. For instance, `+' is defined on numbers, but not on characters or other non- arithmetic types. Operators are often defined on groups of types. `**' The exponentiation operator. It raises the first operand to the power of the second one. `:' The range operator. Normally used in the form of array(low:high) to represent a section of array. `%' The access component operator. Normally used to access elements in derived types. Also suitable for unions. As unions aren't part of regular Fortran, this can only happen when accessing a register that uses a gdbarch-defined union type. `::' The scope operator. Normally used to access variables in modules or to set breakpoints on subroutines nested in modules or in other subroutines (internal subroutines).  File: gdb.info, Node: Fortran Intrinsics, Next: Special Fortran Commands, Prev: Fortran Operators, Up: Fortran 15.4.6.3 Fortran Intrinsics ........................... Fortran provides a large set of intrinsic procedures. GDB implements an incomplete subset of those procedures and their overloads. Some of these procedures take an optional `KIND' parameter, see *Note Fortran Types::. `ABS(A)' Computes the absolute value of its argument A. Currently not supported for `Complex' arguments. `ALLOCATE(ARRAY)' Returns whether ARRAY is allocated or not. `ASSOCIATED(POINTER [, TARGET])' Returns the association status of the pointer POINTER or, if TARGET is present, whether POINTER is associated with the target TARGET. `CEILING(A [, KIND])' Computes the least integer greater than or equal to A. The optional parameter KIND specifies the kind of the return type `Integer(KIND)'. `CMPLX(X [, Y [, KIND]])' Returns a complex number where X is converted to the real component. If Y is present it is converted to the imaginary component. If Y is not present then the imaginary component is set to `0.0' except if X itself is of `Complex' type. The optional parameter KIND specifies the kind of the return type `Complex(KIND)'. `FLOOR(A [, KIND])' Computes the greatest integer less than or equal to A. The optional parameter KIND specifies the kind of the return type `Integer(KIND)'. `KIND(A)' Returns the kind value of the argument A, see *Note Fortran Types::. `LBOUND(ARRAY [, DIM [, KIND]])' Returns the lower bounds of an ARRAY, or a single lower bound along the DIM dimension if present. The optional parameter KIND specifies the kind of the return type `Integer(KIND)'. `LOC(X)' Returns the address of X as an `Integer'. `MOD(A, P)' Computes the remainder of the division of A by P. `MODULO(A, P)' Computes the A modulo P. `RANK(A)' Returns the rank of a scalar or array (scalars have rank `0'). `SHAPE(A)' Returns the shape of a scalar or array (scalars have shape `()'). `SIZE(ARRAY[, DIM [, KIND]])' Returns the extent of ARRAY along a specified dimension DIM, or the total number of elements in ARRAY if DIM is absent. The optional parameter KIND specifies the kind of the return type `Integer(KIND)'. `UBOUND(ARRAY [, DIM [, KIND]])' Returns the upper bounds of an ARRAY, or a single upper bound along the DIM dimension if present. The optional parameter KIND specifies the kind of the return type `Integer(KIND)'.  File: gdb.info, Node: Special Fortran Commands, Prev: Fortran Intrinsics, Up: Fortran 15.4.6.4 Special Fortran Commands ................................. GDB has some commands to support Fortran-specific features, such as displaying common blocks. `info common [COMMON-NAME]' This command prints the values contained in the Fortran `COMMON' block whose name is COMMON-NAME. With no argument, the names of all `COMMON' blocks visible at the current program location are printed. `set fortran repack-array-slices [on|off]' `show fortran repack-array-slices' When taking a slice from an array, a Fortran compiler can choose to either produce an array descriptor that describes the slice in place, or it may repack the slice, copying the elements of the slice into a new region of memory. When this setting is on, then GDB will also repack array slices in some situations. When this setting is off, then GDB will create array descriptors for slices that reference the original data in place. GDB will never repack an array slice if the data for the slice is contiguous within the original array. GDB will always repack string slices if the data for the slice is non-contiguous within the original string as GDB does not support printing non-contiguous strings. The default for this setting is `off'.  File: gdb.info, Node: Pascal, Next: Rust, Prev: Fortran, Up: Supported Languages 15.4.7 Pascal ------------- Debugging Pascal programs which use sets, subranges, file variables, or nested functions does not currently work. GDB does not support entering expressions, printing values, or similar features using Pascal syntax. The Pascal-specific command `set print pascal_static-members' controls whether static members of Pascal objects are displayed. *Note pascal_static-members: Print Settings.  File: gdb.info, Node: Rust, Next: Modula-2, Prev: Pascal, Up: Supported Languages 15.4.8 Rust ----------- GDB supports the Rust Programming Language (https://www.rust-lang.org/). Type- and value-printing, and expression parsing, are reasonably complete. However, there are a few peculiarities and holes to be aware of. * Linespecs (*note Location Specifications::) are never relative to the current crate. Instead, they act as if there were a global namespace of crates, somewhat similar to the way `extern crate' behaves. That is, if GDB is stopped at a breakpoint in a function in crate `A', module `B', then `break B::f' will attempt to set a breakpoint in a function named `f' in a crate named `B'. As a consequence of this approach, linespecs also cannot refer to items using `self::' or `super::'. * Because GDB implements Rust name-lookup semantics in expressions, it will sometimes prepend the current crate to a name. For example, if GDB is stopped at a breakpoint in the crate `K', then `print ::x::y' will try to find the symbol `K::x::y'. However, since it is useful to be able to refer to other crates when debugging, GDB provides the `extern' extension to circumvent this. To use the extension, just put `extern' before a path expression to refer to the otherwise unavailable "global" scope. In the above example, if you wanted to refer to the symbol `y' in the crate `x', you would use `print extern x::y'. * The Rust expression evaluator does not support "statement-like" expressions such as `if' or `match', or lambda expressions. * Tuple expressions are not implemented. * The Rust expression evaluator does not currently implement the `Drop' trait. Objects that may be created by the evaluator will never be destroyed. * GDB does not implement type inference for generics. In order to call generic functions or otherwise refer to generic items, you will have to specify the type parameters manually. * GDB currently uses the C++ demangler for Rust. In most cases this does not cause any problems. However, in an expression context, completing a generic function name will give syntactically invalid results. This happens because Rust requires the `::' operator between the function name and its generic arguments. For example, GDB might provide a completion like `crate::f', where the parser would require `crate::f::'. * As of this writing, the Rust compiler (version 1.8) has a few holes in the debugging information it generates. These holes prevent certain features from being implemented by GDB: * Method calls cannot be made via traits. * Operator overloading is not implemented. * When debugging in a monomorphized function, you cannot use the generic type names. * The type `Self' is not available. * `use' statements are not available, so some names may not be available in the crate.  File: gdb.info, Node: Modula-2, Next: Ada, Prev: Rust, Up: Supported Languages 15.4.9 Modula-2 --------------- The extensions made to GDB to support Modula-2 only support output from the GNU Modula-2 compiler (which is currently being developed). Other Modula-2 compilers are not currently supported, and attempting to debug executables produced by them is most likely to give an error as GDB reads in the executable's symbol table. * Menu: * M2 Operators:: Built-in operators * Built-In Func/Proc:: Built-in functions and procedures * M2 Constants:: Modula-2 constants * M2 Types:: Modula-2 types * M2 Defaults:: Default settings for Modula-2 * Deviations:: Deviations from standard Modula-2 * M2 Checks:: Modula-2 type and range checks * M2 Scope:: The scope operators `::' and `.' * GDB/M2:: GDB and Modula-2  File: gdb.info, Node: M2 Operators, Next: Built-In Func/Proc, Up: Modula-2 15.4.9.1 Operators .................. Operators must be defined on values of specific types. For instance, `+' is defined on numbers, but not on structures. Operators are often defined on groups of types. For the purposes of Modula-2, the following definitions hold: * _Integral types_ consist of `INTEGER', `CARDINAL', and their subranges. * _Character types_ consist of `CHAR' and its subranges. * _Floating-point types_ consist of `REAL'. * _Pointer types_ consist of anything declared as `POINTER TO TYPE'. * _Scalar types_ consist of all of the above. * _Set types_ consist of `SET' and `BITSET' types. * _Boolean types_ consist of `BOOLEAN'. The following operators are supported, and appear in order of increasing precedence: `,' Function argument or array index separator. `:=' Assignment. The value of VAR `:=' VALUE is VALUE. `<, >' Less than, greater than on integral, floating-point, or enumerated types. `<=, >=' Less than or equal to, greater than or equal to on integral, floating-point and enumerated types, or set inclusion on set types. Same precedence as `<'. `=, <>, #' Equality and two ways of expressing inequality, valid on scalar types. Same precedence as `<'. In GDB scripts, only `<>' is available for inequality, since `#' conflicts with the script comment character. `IN' Set membership. Defined on set types and the types of their members. Same precedence as `<'. `OR' Boolean disjunction. Defined on boolean types. `AND, &' Boolean conjunction. Defined on boolean types. `@@' The GDB "artificial array" operator (*note Expressions: Expressions.). `+, -' Addition and subtraction on integral and floating-point types, or union and difference on set types. `*' Multiplication on integral and floating-point types, or set intersection on set types. `/' Division on floating-point types, or symmetric set difference on set types. Same precedence as `*'. `DIV, MOD' Integer division and remainder. Defined on integral types. Same precedence as `*'. `-' Negative. Defined on `INTEGER' and `REAL' data. `^' Pointer dereferencing. Defined on pointer types. `NOT' Boolean negation. Defined on boolean types. Same precedence as `^'. `.' `RECORD' field selector. Defined on `RECORD' data. Same precedence as `^'. `[]' Array indexing. Defined on `ARRAY' data. Same precedence as `^'. `()' Procedure argument list. Defined on `PROCEDURE' objects. Same precedence as `^'. `::, .' GDB and Modula-2 scope operators. _Warning:_ Set expressions and their operations are not yet supported, so GDB treats the use of the operator `IN', or the use of operators `+', `-', `*', `/', `=', , `<>', `#', `<=', and `>=' on sets as an error.  File: gdb.info, Node: Built-In Func/Proc, Next: M2 Constants, Prev: M2 Operators, Up: Modula-2 15.4.9.2 Built-in Functions and Procedures .......................................... Modula-2 also makes available several built-in procedures and functions. In describing these, the following metavariables are used: A represents an `ARRAY' variable. C represents a `CHAR' constant or variable. I represents a variable or constant of integral type. M represents an identifier that belongs to a set. Generally used in the same function with the metavariable S. The type of S should be `SET OF MTYPE' (where MTYPE is the type of M). N represents a variable or constant of integral or floating-point type. R represents a variable or constant of floating-point type. T represents a type. V represents a variable. X represents a variable or constant of one of many types. See the explanation of the function for details. All Modula-2 built-in procedures also return a result, described below. `ABS(N)' Returns the absolute value of N. `CAP(C)' If C is a lower case letter, it returns its upper case equivalent, otherwise it returns its argument. `CHR(I)' Returns the character whose ordinal value is I. `DEC(V)' Decrements the value in the variable V by one. Returns the new value. `DEC(V,I)' Decrements the value in the variable V by I. Returns the new value. `EXCL(M,S)' Removes the element M from the set S. Returns the new set. `FLOAT(I)' Returns the floating point equivalent of the integer I. `HIGH(A)' Returns the index of the last member of A. `INC(V)' Increments the value in the variable V by one. Returns the new value. `INC(V,I)' Increments the value in the variable V by I. Returns the new value. `INCL(M,S)' Adds the element M to the set S if it is not already there. Returns the new set. `MAX(T)' Returns the maximum value of the type T. `MIN(T)' Returns the minimum value of the type T. `ODD(I)' Returns boolean TRUE if I is an odd number. `ORD(X)' Returns the ordinal value of its argument. For example, the ordinal value of a character is its ASCII value (on machines supporting the ASCII character set). The argument X must be of an ordered type, which include integral, character and enumerated types. `SIZE(X)' Returns the size of its argument. The argument X can be a variable or a type. `TRUNC(R)' Returns the integral part of R. `TSIZE(X)' Returns the size of its argument. The argument X can be a variable or a type. `VAL(T,I)' Returns the member of the type T whose ordinal value is I. _Warning:_ Sets and their operations are not yet supported, so GDB treats the use of procedures `INCL' and `EXCL' as an error.  File: gdb.info, Node: M2 Constants, Next: M2 Types, Prev: Built-In Func/Proc, Up: Modula-2 15.4.9.3 Constants .................. GDB allows you to express the constants of Modula-2 in the following ways: * Integer constants are simply a sequence of digits. When used in an expression, a constant is interpreted to be type-compatible with the rest of the expression. Hexadecimal integers are specified by a trailing `H', and octal integers by a trailing `B'. * Floating point constants appear as a sequence of digits, followed by a decimal point and another sequence of digits. An optional exponent can then be specified, in the form `E[+|-]NNN', where `[+|-]NNN' is the desired exponent. All of the digits of the floating point constant must be valid decimal (base 10) digits. * Character constants consist of a single character enclosed by a pair of like quotes, either single (`'') or double (`"'). They may also be expressed by their ordinal value (their ASCII value, usually) followed by a `C'. * String constants consist of a sequence of characters enclosed by a pair of like quotes, either single (`'') or double (`"'). Escape sequences in the style of C are also allowed. *Note C and C++ Constants: C Constants, for a brief explanation of escape sequences. * Enumerated constants consist of an enumerated identifier. * Boolean constants consist of the identifiers `TRUE' and `FALSE'. * Pointer constants consist of integral values only. * Set constants are not yet supported.  File: gdb.info, Node: M2 Types, Next: M2 Defaults, Prev: M2 Constants, Up: Modula-2 15.4.9.4 Modula-2 Types ....................... Currently GDB can print the following data types in Modula-2 syntax: array types, record types, set types, pointer types, procedure types, enumerated types, subrange types and base types. You can also print the contents of variables declared using these type. This section gives a number of simple source code examples together with sample GDB sessions. The first example contains the following section of code: VAR s: SET OF CHAR ; r: [20..40] ; and you can request GDB to interrogate the type and value of `r' and `s'. (gdb) print s {'A'..'C', 'Z'} (gdb) ptype s SET OF CHAR (gdb) print r 21 (gdb) ptype r [20..40] Likewise if your source code declares `s' as: VAR s: SET ['A'..'Z'] ; then you may query the type of `s' by: (gdb) ptype s type = SET ['A'..'Z'] Note that at present you cannot interactively manipulate set expressions using the debugger. The following example shows how you might declare an array in Modula-2 and how you can interact with GDB to print its type and contents: VAR s: ARRAY [-10..10] OF CHAR ; (gdb) ptype s ARRAY [-10..10] OF CHAR Note that the array handling is not yet complete and although the type is printed correctly, expression handling still assumes that all arrays have a lower bound of zero and not `-10' as in the example above. Here are some more type related Modula-2 examples: TYPE colour = (blue, red, yellow, green) ; t = [blue..yellow] ; VAR s: t ; BEGIN s := blue ; The GDB interaction shows how you can query the data type and value of a variable. (gdb) print s $1 = blue (gdb) ptype t type = [blue..yellow] In this example a Modula-2 array is declared and its contents displayed. Observe that the contents are written in the same way as their `C' counterparts. VAR s: ARRAY [1..5] OF CARDINAL ; BEGIN s[1] := 1 ; (gdb) print s $1 = {1, 0, 0, 0, 0} (gdb) ptype s type = ARRAY [1..5] OF CARDINAL The Modula-2 language interface to GDB also understands pointer types as shown in this example: VAR s: POINTER TO ARRAY [1..5] OF CARDINAL ; BEGIN NEW(s) ; s^[1] := 1 ; and you can request that GDB describes the type of `s'. (gdb) ptype s type = POINTER TO ARRAY [1..5] OF CARDINAL GDB handles compound types as we can see in this example. Here we combine array types, record types, pointer types and subrange types: TYPE foo = RECORD f1: CARDINAL ; f2: CHAR ; f3: myarray ; END ; myarray = ARRAY myrange OF CARDINAL ; myrange = [-2..2] ; VAR s: POINTER TO ARRAY myrange OF foo ; and you can ask GDB to describe the type of `s' as shown below. (gdb) ptype s type = POINTER TO ARRAY [-2..2] OF foo = RECORD f1 : CARDINAL; f2 : CHAR; f3 : ARRAY [-2..2] OF CARDINAL; END  File: gdb.info, Node: M2 Defaults, Next: Deviations, Prev: M2 Types, Up: Modula-2 15.4.9.5 Modula-2 Defaults .......................... If type and range checking are set automatically by GDB, they both default to `on' whenever the working language changes to Modula-2. This happens regardless of whether you or GDB selected the working language. If you allow GDB to set the language automatically, then entering code compiled from a file whose name ends with `.mod' sets the working language to Modula-2. *Note Having GDB Infer the Source Language: Automatically, for further details.  File: gdb.info, Node: Deviations, Next: M2 Checks, Prev: M2 Defaults, Up: Modula-2 15.4.9.6 Deviations from Standard Modula-2 .......................................... A few changes have been made to make Modula-2 programs easier to debug. This is done primarily via loosening its type strictness: * Unlike in standard Modula-2, pointer constants can be formed by integers. This allows you to modify pointer variables during debugging. (In standard Modula-2, the actual address contained in a pointer variable is hidden from you; it can only be modified through direct assignment to another pointer variable or expression that returned a pointer.) * C escape sequences can be used in strings and characters to represent non-printable characters. GDB prints out strings with these escape sequences embedded. Single non-printable characters are printed using the `CHR(NNN)' format. * The assignment operator (`:=') returns the value of its right-hand argument. * All built-in procedures both modify _and_ return their argument.  File: gdb.info, Node: M2 Checks, Next: M2 Scope, Prev: Deviations, Up: Modula-2 15.4.9.7 Modula-2 Type and Range Checks ....................................... _Warning:_ in this release, GDB does not yet perform type or range checking. GDB considers two Modula-2 variables type equivalent if: * They are of types that have been declared equivalent via a `TYPE T1 = T2' statement * They have been declared on the same line. (Note: This is true of the GNU Modula-2 compiler, but it may not be true of other compilers.) As long as type checking is enabled, any attempt to combine variables whose types are not equivalent is an error. Range checking is done on all mathematical operations, assignment, array index bounds, and all built-in functions and procedures.  File: gdb.info, Node: M2 Scope, Next: GDB/M2, Prev: M2 Checks, Up: Modula-2 15.4.9.8 The Scope Operators `::' and `.' ......................................... There are a few subtle differences between the Modula-2 scope operator (`.') and the GDB scope operator (`::'). The two have similar syntax: MODULE . ID SCOPE :: ID where SCOPE is the name of a module or a procedure, MODULE the name of a module, and ID is any declared identifier within your program, except another module. Using the `::' operator makes GDB search the scope specified by SCOPE for the identifier ID. If it is not found in the specified scope, then GDB searches all scopes enclosing the one specified by SCOPE. Using the `.' operator makes GDB search the current scope for the identifier specified by ID that was imported from the definition module specified by MODULE. With this operator, it is an error if the identifier ID was not imported from definition module MODULE, or if ID is not an identifier in MODULE.  File: gdb.info, Node: GDB/M2, Prev: M2 Scope, Up: Modula-2 15.4.9.9 GDB and Modula-2 ......................... Some GDB commands have little use when debugging Modula-2 programs. Five subcommands of `set print' and `show print' apply specifically to C and C++: `vtbl', `demangle', `asm-demangle', `object', and `union'. The first four apply to C++, and the last to the C `union' type, which has no direct analogue in Modula-2. The `@@' operator (*note Expressions: Expressions.), while available with any language, is not useful with Modula-2. Its intent is to aid the debugging of "dynamic arrays", which cannot be created in Modula-2 as they can in C or C++. However, because an address can be specified by an integral constant, the construct `{TYPE}ADREXP' is still useful. In GDB scripts, the Modula-2 inequality operator `#' is interpreted as the beginning of a comment. Use `<>' instead.  File: gdb.info, Node: Ada, Prev: Modula-2, Up: Supported Languages 15.4.10 Ada ----------- The extensions made to GDB for Ada only support output from the GNU Ada (GNAT) compiler. Other Ada compilers are not currently supported, and attempting to debug executables produced by them is most likely to be difficult. * Menu: * Ada Mode Intro:: General remarks on the Ada syntax and semantics supported by Ada mode in GDB. * Omissions from Ada:: Restrictions on the Ada expression syntax. * Additions to Ada:: Extensions of the Ada expression syntax. * Overloading support for Ada:: Support for expressions involving overloaded subprograms. * Stopping Before Main Program:: Debugging the program during elaboration. * Ada Exceptions:: Ada Exceptions * Ada Tasks:: Listing and setting breakpoints in tasks. * Ada Tasks and Core Files:: Tasking Support when Debugging Core Files * Ravenscar Profile:: Tasking Support when using the Ravenscar Profile * Ada Source Character Set:: Character set of Ada source files. * Ada Glitches:: Known peculiarities of Ada mode.  File: gdb.info, Node: Ada Mode Intro, Next: Omissions from Ada, Up: Ada 15.4.10.1 Introduction ...................... The Ada mode of GDB supports a fairly large subset of Ada expression syntax, with some extensions. The philosophy behind the design of this subset is * That GDB should provide basic literals and access to operations for arithmetic, dereferencing, field selection, indexing, and subprogram calls, leaving more sophisticated computations to subprograms written into the program (which therefore may be called from GDB). * That type safety and strict adherence to Ada language restrictions are not particularly important to the GDB user. * That brevity is important to the GDB user. Thus, for brevity, the debugger acts as if all names declared in user-written packages are directly visible, even if they are not visible according to Ada rules, thus making it unnecessary to fully qualify most names with their packages, regardless of context. Where this causes ambiguity, GDB asks the user's intent. The debugger will start in Ada mode if it detects an Ada main program. As for other languages, it will enter Ada mode when stopped in a program that was translated from an Ada source file. While in Ada mode, you may use `-' for comments. This is useful mostly for documenting command files. The standard GDB comment (`#') still works at the beginning of a line in Ada mode, but not in the middle (to allow based literals).  File: gdb.info, Node: Omissions from Ada, Next: Additions to Ada, Prev: Ada Mode Intro, Up: Ada 15.4.10.2 Omissions from Ada ............................ Here are the notable omissions from the subset: * Only a subset of the attributes are supported: - 'First, 'Last, and 'Length on array objects (not on types and subtypes). - 'Min and 'Max. - 'Pos and 'Val. - 'Tag. - 'Range on array objects (not subtypes), but only as the right operand of the membership (`in') operator. - 'Access, 'Unchecked_Access, and 'Unrestricted_Access (a GNAT extension). - 'Address. * The names in `Characters.Latin_1' are not available. * Equality tests (`=' and `/=') on arrays test for bitwise equality of representations. They will generally work correctly for strings and arrays whose elements have integer or enumeration types. They may not work correctly for arrays whose element types have user-defined equality, for arrays of real values (in particular, IEEE-conformant floating point, because of negative zeroes and NaNs), and for arrays whose elements contain unused bits with indeterminate values. * The other component-by-component array operations (`and', `or', `xor', `not', and relational tests other than equality) are not implemented. * There is limited support for array and record aggregates. They are permitted only on the right sides of assignments, as in these examples: (gdb) set An_Array := (1, 2, 3, 4, 5, 6) (gdb) set An_Array := (1, others => 0) (gdb) set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6) (gdb) set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9)) (gdb) set A_Record := (1, "Peter", True); (gdb) set A_Record := (Name => "Peter", Id => 1, Alive => True) Changing a discriminant's value by assigning an aggregate has an undefined effect if that discriminant is used within the record. However, you can first modify discriminants by directly assigning to them (which normally would not be allowed in Ada), and then performing an aggregate assignment. For example, given a variable `A_Rec' declared to have a type such as: type Rec (Len : Small_Integer := 0) is record Id : Integer; Vals : IntArray (1 .. Len); end record; you can assign a value with a different size of `Vals' with two assignments: (gdb) set A_Rec.Len := 4 (gdb) set A_Rec := (Id => 42, Vals => (1, 2, 3, 4)) As this example also illustrates, GDB is very loose about the usual rules concerning aggregates. You may leave out some of the components of an array or record aggregate (such as the `Len' component in the assignment to `A_Rec' above); they will retain their original values upon assignment. You may freely use dynamic values as indices in component associations. You may even use overlapping or redundant component associations, although which component values are assigned in such cases is not defined. * Calls to dispatching subprograms are not implemented. * The overloading algorithm is much more limited (i.e., less selective) than that of real Ada. It makes only limited use of the context in which a subexpression appears to resolve its meaning, and it is much looser in its rules for allowing type matches. As a result, some function calls will be ambiguous, and the user will be asked to choose the proper resolution. * The `new' operator is not implemented. * Entry calls are not implemented. * Aside from printing, arithmetic operations on the native VAX floating-point formats are not supported. * It is not possible to slice a packed array. * The names `True' and `False', when not part of a qualified name, are interpreted as if implicitly prefixed by `Standard', regardless of context. Should your program redefine these names in a package or procedure (at best a dubious practice), you will have to use fully qualified names to access their new definitions. * Based real literals are not implemented.  File: gdb.info, Node: Additions to Ada, Next: Overloading support for Ada, Prev: Omissions from Ada, Up: Ada 15.4.10.3 Additions to Ada .......................... As it does for other languages, GDB makes certain generic extensions to Ada (*note Expressions::): * If the expression E is a variable residing in memory (typically a local variable or array element) and N is a positive integer, then `E@@N' displays the values of E and the N-1 adjacent variables following it in memory as an array. In Ada, this operator is generally not necessary, since its prime use is in displaying parts of an array, and slicing will usually do this in Ada. However, there are occasional uses when debugging programs in which certain debugging information has been optimized away. * `B::VAR' means "the variable named VAR that appears in function or file B." When B is a file name, you must typically surround it in single quotes. * The expression `{TYPE} ADDR' means "the variable of type TYPE that appears at address ADDR." * A name starting with `$' is a convenience variable (*note Convenience Vars::) or a machine register (*note Registers::). In addition, GDB provides a few other shortcuts and outright additions specific to Ada: * The assignment statement is allowed as an expression, returning its right-hand operand as its value. Thus, you may enter (gdb) set x := y + 3 (gdb) print A(tmp := y + 1) * The semicolon is allowed as an "operator," returning as its value the value of its right-hand operand. This allows, for example, complex conditional breaks: (gdb) break f (gdb) condition 1 (report(i); k += 1; A(k) > 100) * An extension to based literals can be used to specify the exact byte contents of a floating-point literal. After the base, you can use from zero to two `l' characters, followed by an `f'. The number of `l' characters controls the width of the resulting real constant: zero means `Float' is used, one means `Long_Float', and two means `Long_Long_Float'. (gdb) print 16f#41b80000# $1 = 23.0 * Rather than use catenation and symbolic character names to introduce special characters into strings, one may instead use a special bracket notation, which is also used to print strings. A sequence of characters of the form `["XX"]' within a string or character literal denotes the (single) character whose numeric encoding is XX in hexadecimal. The sequence of characters `["""]' also denotes a single quotation mark in strings. For example, "One line.["0a"]Next line.["0a"]" contains an ASCII newline character (`Ada.Characters.Latin_1.LF') after each period. * The subtype used as a prefix for the attributes 'Pos, 'Min, and 'Max is optional (and is ignored in any case). For example, it is valid to write (gdb) print 'max(x, y) * When printing arrays, GDB uses positional notation when the array has a lower bound of 1, and uses a modified named notation otherwise. For example, a one-dimensional array of three integers with a lower bound of 3 might print as (3 => 10, 17, 1) That is, in contrast to valid Ada, only the first component has a `=>' clause. * You may abbreviate attributes in expressions with any unique, multi-character subsequence of their names (an exact match gets preference). For example, you may use a'len, a'gth, or a'lh in place of a'length. * Since Ada is case-insensitive, the debugger normally maps identifiers you type to lower case. The GNAT compiler uses upper-case characters for some of its internal identifiers, which are normally of no interest to users. For the rare occasions when you actually have to look at them, enclose them in angle brackets to avoid the lower-case mapping. For example, (gdb) print [0] * Printing an object of class-wide type or dereferencing an access-to-class-wide value will display all the components of the object's specific type (as indicated by its run-time tag). Likewise, component selection on such a value will operate on the specific type of the object.  File: gdb.info, Node: Overloading support for Ada, Next: Stopping Before Main Program, Prev: Additions to Ada, Up: Ada 15.4.10.4 Overloading support for Ada ..................................... The debugger supports limited overloading. Given a subprogram call in which the function symbol has multiple definitions, it will use the number of actual parameters and some information about their types to attempt to narrow the set of definitions. It also makes very limited use of context, preferring procedures to functions in the context of the `call' command, and functions to procedures elsewhere. If, after narrowing, the set of matching definitions still contains more than one definition, GDB will display a menu to query which one it should use, for instance: (gdb) print f(1) Multiple matches for f [0] cancel [1] foo.f (integer) return boolean at foo.adb:23 [2] foo.f (foo.new_integer) return boolean at foo.adb:28 > In this case, just select one menu entry either to cancel expression evaluation (type `0' and press ) or to continue evaluation with a specific instance (type the corresponding number and press ). Here are a couple of commands to customize GDB's behavior in this case: `set ada print-signatures' Control whether parameter types and return types are displayed in overloads selection menus. It is `on' by default. *Note Overloading support for Ada::. `show ada print-signatures' Show the current setting for displaying parameter types and return types in overloads selection menu. *Note Overloading support for Ada::.  File: gdb.info, Node: Stopping Before Main Program, Next: Ada Exceptions, Prev: Overloading support for Ada, Up: Ada 15.4.10.5 Stopping at the Very Beginning ........................................ It is sometimes necessary to debug the program during elaboration, and before reaching the main procedure. As defined in the Ada Reference Manual, the elaboration code is invoked from a procedure called `adainit'. To run your program up to the beginning of elaboration, simply use the following two commands: `tbreak adainit' and `run'.  File: gdb.info, Node: Ada Exceptions, Next: Ada Tasks, Prev: Stopping Before Main Program, Up: Ada 15.4.10.6 Ada Exceptions ........................ A command is provided to list all Ada exceptions: `info exceptions' `info exceptions REGEXP' The `info exceptions' command allows you to list all Ada exceptions defined within the program being debugged, as well as their addresses. With a regular expression, REGEXP, as argument, only those exceptions whose names match REGEXP are listed. Below is a small example, showing how the command can be used, first without argument, and next with a regular expression passed as an argument. (gdb) info exceptions All defined Ada exceptions: constraint_error: 0x613da0 program_error: 0x613d20 storage_error: 0x613ce0 tasking_error: 0x613ca0 const.aint_global_e: 0x613b00 (gdb) info exceptions const.aint All Ada exceptions matching regular expression "const.aint": constraint_error: 0x613da0 const.aint_global_e: 0x613b00 It is also possible to ask GDB to stop your program's execution when an exception is raised. For more details, see *Note Set Catchpoints::.  File: gdb.info, Node: Ada Tasks, Next: Ada Tasks and Core Files, Prev: Ada Exceptions, Up: Ada 15.4.10.7 Extensions for Ada Tasks .................................. Support for Ada tasks is analogous to that for threads (*note Threads::). GDB provides the following task-related commands: `info tasks' This command shows a list of current Ada tasks, as in the following example: (gdb) info tasks ID TID P-ID Pri State Name 1 8088000 0 15 Child Activation Wait main_task 2 80a4000 1 15 Accept Statement b 3 809a800 1 15 Child Activation Wait a * 4 80ae800 3 15 Runnable c In this listing, the asterisk before the last task indicates it to be the task currently being inspected. ID Represents GDB's internal task number. TID The Ada task ID. P-ID The parent's task ID (GDB's internal task number). Pri The base priority of the task. State Current state of the task. `Unactivated' The task has been created but has not been activated. It cannot be executing. `Runnable' The task is not blocked for any reason known to Ada. (It may be waiting for a mutex, though.) It is conceptually "executing" in normal mode. `Terminated' The task is terminated, in the sense of ARM 9.3 (5). Any dependents that were waiting on terminate alternatives have been awakened and have terminated themselves. `Child Activation Wait' The task is waiting for created tasks to complete activation. `Accept or Select Term' The task is waiting on an accept or selective wait statement. `Waiting on entry call' The task is waiting on an entry call. `Async Select Wait' The task is waiting to start the abortable part of an asynchronous select statement. `Delay Sleep' The task is waiting on a select statement with only a delay alternative open. `Child Termination Wait' The task is sleeping having completed a master within itself, and is waiting for the tasks dependent on that master to become terminated or waiting on a terminate Phase. `Wait Child in Term Alt' The task is sleeping waiting for tasks on terminate alternatives to finish terminating. `Asynchronous Hold' The task has been held by `Ada.Asynchronous_Task_Control.Hold_Task'. `Activating' The task has been created and is being made runnable. `Selective Wait' The task is waiting in a selective wait statement. `Accepting RV with TASKNO' The task is accepting a rendez-vous with the task TASKNO. `Waiting on RV with TASKNO' The task is waiting for a rendez-vous with the task TASKNO. Name Name of the task in the program. `info task TASKNO' This command shows detailed information on the specified task, as in the following example: (gdb) info tasks ID TID P-ID Pri State Name 1 8077880 0 15 Child Activation Wait main_task * 2 807c468 1 15 Runnable task_1 (gdb) info task 2 Ada Task: 0x807c468 Name: "task_1" Thread: 0 LWP: 0x1fac Parent: 1 ("main_task") Base Priority: 15 State: Runnable `task' This command prints the ID and name of the current task. (gdb) info tasks ID TID P-ID Pri State Name 1 8077870 0 15 Child Activation Wait main_task * 2 807c458 1 15 Runnable some_task (gdb) task [Current task is 2 "some_task"] `task TASKNO' This command is like the `thread THREAD-ID' command (*note Threads::). It switches the context of debugging from the current task to the given task. (gdb) info tasks ID TID P-ID Pri State Name 1 8077870 0 15 Child Activation Wait main_task * 2 807c458 1 15 Runnable some_task (gdb) task 1 [Switching to task 1 "main_task"] #0 0x8067726 in pthread_cond_wait () (gdb) bt #0 0x8067726 in pthread_cond_wait () #1 0x8056714 in system.os_interface.pthread_cond_wait () #2 0x805cb63 in system.task_primitives.operations.sleep () #3 0x806153e in system.tasking.stages.activate_tasks () #4 0x804aacc in un () at un.adb:5 `task apply [TASK-ID-LIST | all] [FLAG]... COMMAND' The `task apply' command is the Ada tasking analogue of `thread apply' (*note Threads::). It allows you to apply the named COMMAND to one or more tasks. Specify the tasks that you want affected using a list of task IDs, or specify `all' to apply to all tasks. The FLAG arguments control what output to produce and how to handle errors raised when applying COMMAND to a task. FLAG must start with a `-' directly followed by one letter in `qcs'. If several flags are provided, they must be given individually, such as `-c -q'. By default, GDB displays some task information before the output produced by COMMAND, and an error raised during the execution of a COMMAND will abort `task apply'. The following flags can be used to fine-tune this behavior: `-c' The flag `-c', which stands for `continue', causes any errors in COMMAND to be displayed, and the execution of `task apply' then continues. `-s' The flag `-s', which stands for `silent', causes any errors or empty output produced by a COMMAND to be silently ignored. That is, the execution continues, but the task information and errors are not printed. `-q' The flag `-q' (`quiet') disables printing the task information. Flags `-c' and `-s' cannot be used together. `break LOCSPEC task TASKNO' `break LOCSPEC task TASKNO if ...' These commands are like the `break ... thread ...' command (*note Thread Stops::). *Note Location Specifications::, for the various forms of LOCSPEC. Use the qualifier `task TASKNO' with a breakpoint command to specify that you only want GDB to stop the program when a particular Ada task reaches this breakpoint. The TASKNO is one of the numeric task identifiers assigned by GDB, shown in the first column of the `info tasks' display. If you do not specify `task TASKNO' when you set a breakpoint, the breakpoint applies to _all_ tasks of your program. You can use the `task' qualifier on conditional breakpoints as well; in this case, place `task TASKNO' before the breakpoint condition (before the `if'). For example, (gdb) info tasks ID TID P-ID Pri State Name 1 140022020 0 15 Child Activation Wait main_task 2 140045060 1 15 Accept/Select Wait t2 3 140044840 1 15 Runnable t1 * 4 140056040 1 15 Runnable t3 (gdb) b 15 task 2 Breakpoint 5 at 0x120044cb0: file test_task_debug.adb, line 15. (gdb) cont Continuing. task # 1 running task # 2 running Breakpoint 5, test_task_debug () at test_task_debug.adb:15 15 flush; (gdb) info tasks ID TID P-ID Pri State Name 1 140022020 0 15 Child Activation Wait main_task * 2 140045060 1 15 Runnable t2 3 140044840 1 15 Runnable t1 4 140056040 1 15 Delay Sleep t3  File: gdb.info, Node: Ada Tasks and Core Files, Next: Ravenscar Profile, Prev: Ada Tasks, Up: Ada 15.4.10.8 Tasking Support when Debugging Core Files ................................................... When inspecting a core file, as opposed to debugging a live program, tasking support may be limited or even unavailable, depending on the platform being used. For instance, on x86-linux, the list of tasks is available, but task switching is not supported. On certain platforms, the debugger needs to perform some memory writes in order to provide Ada tasking support. When inspecting a core file, this means that the core file must be opened with read-write privileges, using the command `"set write on"' (*note Patching::). Under these circumstances, you should make a backup copy of the core file before inspecting it with GDB.  File: gdb.info, Node: Ravenscar Profile, Next: Ada Source Character Set, Prev: Ada Tasks and Core Files, Up: Ada 15.4.10.9 Tasking Support when using the Ravenscar Profile .......................................................... The "Ravenscar Profile" is a subset of the Ada tasking features, specifically designed for systems with safety-critical real-time requirements. `set ravenscar task-switching on' Allows task switching when debugging a program that uses the Ravenscar Profile. This is the default. `set ravenscar task-switching off' Turn off task switching when debugging a program that uses the Ravenscar Profile. This is mostly intended to disable the code that adds support for the Ravenscar Profile, in case a bug in either GDB or in the Ravenscar runtime is preventing GDB from working properly. To be effective, this command should be run before the program is started. `show ravenscar task-switching' Show whether it is possible to switch from task to task in a program using the Ravenscar Profile. When Ravenscar task-switching is enabled, Ravenscar tasks are announced by GDB as if they were threads: (gdb) continue [New Ravenscar Thread 0x2b8f0] Both Ravenscar tasks and the underlying CPU threads will show up in the output of `info threads': (gdb) info threads Id Target Id Frame 1 Thread 1 (CPU#0 [running]) simple () at simple.adb:10 2 Thread 2 (CPU#1 [running]) 0x0000000000003d34 in __gnat_initialize_cpu_devices () 3 Thread 3 (CPU#2 [running]) 0x0000000000003d28 in __gnat_initialize_cpu_devices () 4 Thread 4 (CPU#3 [halted ]) 0x000000000000c6ec in system.task_primitives.operations.idle () * 5 Ravenscar Thread 0x2b8f0 simple () at simple.adb:10 6 Ravenscar Thread 0x2f150 0x000000000000c6ec in system.task_primitives.operations.idle () One known limitation of the Ravenscar support in GDB is that it isn't currently possible to single-step through the runtime initialization sequence. If you need to debug this code, you should use `set ravenscar task-switching off'.  File: gdb.info, Node: Ada Source Character Set, Next: Ada Glitches, Prev: Ravenscar Profile, Up: Ada 15.4.10.10 Ada Source Character Set ................................... The GNAT compiler supports a number of character sets for source files. *Note Character Set Control: (gnat_ugn)Character Set Control. GDB includes support for this as well. `set ada source-charset CHARSET' Set the source character set for Ada. The character set must be supported by GNAT. Because this setting affects the decoding of symbols coming from the debug information in your program, the setting should be set as early as possible. The default is `ISO-8859-1', because that is also GNAT's default. `show ada source-charset' Show the current source character set for Ada.  File: gdb.info, Node: Ada Glitches, Prev: Ada Source Character Set, Up: Ada 15.4.10.11 Known Peculiarities of Ada Mode .......................................... Besides the omissions listed previously (*note Omissions from Ada::), we know of several problems with and limitations of Ada mode in GDB, some of which will be fixed with planned future releases of the debugger and the GNU Ada compiler. * Static constants that the compiler chooses not to materialize as objects in storage are invisible to the debugger. * Named parameter associations in function argument lists are ignored (the argument lists are treated as positional). * Many useful library packages are currently invisible to the debugger. * Fixed-point arithmetic, conversions, input, and output is carried out using floating-point arithmetic, and may give results that only approximate those on the host machine. * The GNAT compiler never generates the prefix `Standard' for any of the standard symbols defined by the Ada language. GDB knows about this: it will strip the prefix from names when you use it, and will never look for a name you have so qualified among local symbols, nor match against symbols in other packages or subprograms. If you have defined entities anywhere in your program other than parameters and local variables whose simple names match names in `Standard', GNAT's lack of qualification here can cause confusion. When this happens, you can usually resolve the confusion by qualifying the problematic names with package `Standard' explicitly. Older versions of the compiler sometimes generate erroneous debugging information, resulting in the debugger incorrectly printing the value of affected entities. In some cases, the debugger is able to work around an issue automatically. In other cases, the debugger is able to work around the issue, but the work-around has to be specifically enabled. `set ada trust-PAD-over-XVS on' Configure GDB to strictly follow the GNAT encoding when computing the value of Ada entities, particularly when `PAD' and `PAD___XVS' types are involved (see `ada/exp_dbug.ads' in the GCC sources for a complete description of the encoding used by the GNAT compiler). This is the default. `set ada trust-PAD-over-XVS off' This is related to the encoding using by the GNAT compiler. If GDB sometimes prints the wrong value for certain entities, changing `ada trust-PAD-over-XVS' to `off' activates a work-around which may fix the issue. It is always safe to set `ada trust-PAD-over-XVS' to `off', but this incurs a slight performance penalty, so it is recommended to leave this setting to `on' unless necessary. Internally, the debugger also relies on the compiler following a number of conventions known as the `GNAT Encoding', all documented in `gcc/ada/exp_dbug.ads' in the GCC sources. This encoding describes how the debugging information should be generated for certain types. In particular, this convention makes use of "descriptive types", which are artificial types generated purely to help the debugger. These encodings were defined at a time when the debugging information format used was not powerful enough to describe some of the more complex types available in Ada. Since DWARF allows us to express nearly all Ada features, the long-term goal is to slowly replace these descriptive types by their pure DWARF equivalent. To facilitate that transition, a new maintenance option is available to force the debugger to ignore those descriptive types. It allows the user to quickly evaluate how well GDB works without them. `maintenance ada set ignore-descriptive-types [on|off]' Control whether the debugger should ignore descriptive types. The default is not to ignore descriptives types (`off'). `maintenance ada show ignore-descriptive-types' Show if descriptive types are ignored by GDB.  File: gdb.info, Node: Unsupported Languages, Prev: Supported Languages, Up: Languages 15.5 Unsupported Languages ========================== In addition to the other fully-supported programming languages, GDB also provides a pseudo-language, called `minimal'. It does not represent a real programming language, but provides a set of capabilities close to what the C or assembly languages provide. This should allow most simple operations to be performed while debugging an application that uses a language currently not supported by GDB. If the language is set to `auto', GDB will automatically select this language if the current frame corresponds to an unsupported language.  File: gdb.info, Node: Symbols, Next: Altering, Prev: Languages, Up: Top 16 Examining the Symbol Table ***************************** The commands described in this chapter allow you to inquire about the symbols (names of variables, functions and types) defined in your program. This information is inherent in the text of your program and does not change as your program executes. GDB finds it in your program's symbol table, in the file indicated when you started GDB (*note Choosing Files: File Options.), or by one of the file-management commands (*note Commands to Specify Files: Files.). Occasionally, you may need to refer to symbols that contain unusual characters, which GDB ordinarily treats as word delimiters. The most frequent case is in referring to static variables in other source files (*note Program Variables: Variables.). File names are recorded in object files as debugging symbols, but GDB would ordinarily parse a typical file name, like `foo.c', as the three words `foo' `.' `c'. To allow GDB to recognize `foo.c' as a single symbol, enclose it in single quotes; for example, p 'foo.c'::x looks up the value of `x' in the scope of the file `foo.c'. `set case-sensitive on' `set case-sensitive off' `set case-sensitive auto' Normally, when GDB looks up symbols, it matches their names with case sensitivity determined by the current source language. Occasionally, you may wish to control that. The command `set case-sensitive' lets you do that by specifying `on' for case-sensitive matches or `off' for case-insensitive ones. If you specify `auto', case sensitivity is reset to the default suitable for the source language. The default is case-sensitive matches for all languages except for Fortran, for which the default is case-insensitive matches. `show case-sensitive' This command shows the current setting of case sensitivity for symbols lookups. `set print type methods' `set print type methods on' `set print type methods off' Normally, when GDB prints a class, it displays any methods declared in that class. You can control this behavior either by passing the appropriate flag to `ptype', or using `set print type methods'. Specifying `on' will cause GDB to display the methods; this is the default. Specifying `off' will cause GDB to omit the methods. `show print type methods' This command shows the current setting of method display when printing classes. `set print type nested-type-limit LIMIT' `set print type nested-type-limit unlimited' Set the limit of displayed nested types that the type printer will show. A LIMIT of `unlimited' or `-1' will show all nested definitions. By default, the type printer will not show any nested types defined in classes. `show print type nested-type-limit' This command shows the current display limit of nested types when printing classes. `set print type typedefs' `set print type typedefs on' `set print type typedefs off' Normally, when GDB prints a class, it displays any typedefs defined in that class. You can control this behavior either by passing the appropriate flag to `ptype', or using `set print type typedefs'. Specifying `on' will cause GDB to display the typedef definitions; this is the default. Specifying `off' will cause GDB to omit the typedef definitions. Note that this controls whether the typedef definition itself is printed, not whether typedef names are substituted when printing other types. `show print type typedefs' This command shows the current setting of typedef display when printing classes. `set print type hex' `set print type hex on' `set print type hex off' When GDB prints sizes and offsets of struct members, it can use either the decimal or hexadecimal notation. You can select one or the other either by passing the appropriate flag to `ptype', or by using the `set print type hex' command. `show print type hex' This command shows whether the sizes and offsets of struct members are printed in decimal or hexadecimal notation. `info address SYMBOL' Describe where the data for SYMBOL is stored. For a register variable, this says which register it is kept in. For a non-register local variable, this prints the stack-frame offset at which the variable is always stored. Note the contrast with `print &SYMBOL', which does not work at all for a register variable, and for a stack local variable prints the exact address of the current instantiation of the variable. `info symbol ADDR' Print the name of a symbol which is stored at the address ADDR. If no symbol is stored exactly at ADDR, GDB prints the nearest symbol and an offset from it: (gdb) info symbol 0x54320 _initialize_vx + 396 in section .text This is the opposite of the `info address' command. You can use it to find out the name of a variable or a function given its address. For dynamically linked executables, the name of executable or shared library containing the symbol is also printed: (gdb) info symbol 0x400225 _start + 5 in section .text of /tmp/a.out (gdb) info symbol 0x2aaaac2811cf __read_nocancel + 6 in section .text of /usr/lib64/libc.so.6 `demangle [-l LANGUAGE] [-] NAME' Demangle NAME. If LANGUAGE is provided it is the name of the language to demangle NAME in. Otherwise NAME is demangled in the current language. The `--' option specifies the end of options, and is useful when NAME begins with a dash. The parameter `demangle-style' specifies how to interpret the kind of mangling used. *Note Print Settings::. `whatis[/FLAGS] [ARG]' Print the data type of ARG, which can be either an expression or a name of a data type. With no argument, print the data type of `$', the last value in the value history. If ARG is an expression (*note Expressions: Expressions.), it is not actually evaluated, and any side-effecting operations (such as assignments or function calls) inside it do not take place. If ARG is a variable or an expression, `whatis' prints its literal type as it is used in the source code. If the type was defined using a `typedef', `whatis' will _not_ print the data type underlying the `typedef'. If the type of the variable or the expression is a compound data type, such as `struct' or `class', `whatis' never prints their fields or methods. It just prints the `struct'/`class' name (a.k.a. its "tag"). If you want to see the members of such a compound data type, use `ptype'. If ARG is a type name that was defined using `typedef', `whatis' "unrolls" only one level of that `typedef'. Unrolling means that `whatis' will show the underlying type used in the `typedef' declaration of ARG. However, if that underlying type is also a `typedef', `whatis' will not unroll it. For C code, the type names may also have the form `class CLASS-NAME', `struct STRUCT-TAG', `union UNION-TAG' or `enum ENUM-TAG'. FLAGS can be used to modify how the type is displayed. Available flags are: `r' Display in "raw" form. Normally, GDB substitutes template parameters and typedefs defined in a class when printing the class' members. The `/r' flag disables this. `m' Do not print methods defined in the class. `M' Print methods defined in the class. This is the default, but the flag exists in case you change the default with `set print type methods'. `t' Do not print typedefs defined in the class. Note that this controls whether the typedef definition itself is printed, not whether typedef names are substituted when printing other types. `T' Print typedefs defined in the class. This is the default, but the flag exists in case you change the default with `set print type typedefs'. `o' Print the offsets and sizes of fields in a struct, similar to what the `pahole' tool does. This option implies the `/tm' flags. `x' Use hexadecimal notation when printing offsets and sizes of fields in a struct. `d' Use decimal notation when printing offsets and sizes of fields in a struct. For example, given the following declarations: struct tuv { int a1; char *a2; int a3; }; struct xyz { int f1; char f2; void *f3; struct tuv f4; }; union qwe { struct tuv fff1; struct xyz fff2; }; struct tyu { int a1 : 1; int a2 : 3; int a3 : 23; char a4 : 2; int64_t a5; int a6 : 5; int64_t a7 : 3; }; Issuing a `ptype /o struct tuv' command would print: (gdb) ptype /o struct tuv /* offset | size */ type = struct tuv { /* 0 | 4 */ int a1; /* XXX 4-byte hole */ /* 8 | 8 */ char *a2; /* 16 | 4 */ int a3; /* total size (bytes): 24 */ } Notice the format of the first column of comments. There, you can find two parts separated by the `|' character: the _offset_, which indicates where the field is located inside the struct, in bytes, and the _size_ of the field. Another interesting line is the marker of a _hole_ in the struct, indicating that it may be possible to pack the struct and make it use less space by reorganizing its fields. It is also possible to print offsets inside an union: (gdb) ptype /o union qwe /* offset | size */ type = union qwe { /* 24 */ struct tuv { /* 0 | 4 */ int a1; /* XXX 4-byte hole */ /* 8 | 8 */ char *a2; /* 16 | 4 */ int a3; /* total size (bytes): 24 */ } fff1; /* 40 */ struct xyz { /* 0 | 4 */ int f1; /* 4 | 1 */ char f2; /* XXX 3-byte hole */ /* 8 | 8 */ void *f3; /* 16 | 24 */ struct tuv { /* 16 | 4 */ int a1; /* XXX 4-byte hole */ /* 24 | 8 */ char *a2; /* 32 | 4 */ int a3; /* total size (bytes): 24 */ } f4; /* total size (bytes): 40 */ } fff2; /* total size (bytes): 40 */ } In this case, since `struct tuv' and `struct xyz' occupy the same space (because we are dealing with an union), the offset is not printed for them. However, you can still examine the offset of each of these structures' fields. Another useful scenario is printing the offsets of a struct containing bitfields: (gdb) ptype /o struct tyu /* offset | size */ type = struct tyu { /* 0:31 | 4 */ int a1 : 1; /* 0:28 | 4 */ int a2 : 3; /* 0: 5 | 4 */ int a3 : 23; /* 3: 3 | 1 */ signed char a4 : 2; /* XXX 3-bit hole */ /* XXX 4-byte hole */ /* 8 | 8 */ int64_t a5; /* 16: 0 | 4 */ int a6 : 5; /* 16: 5 | 8 */ int64_t a7 : 3; /* XXX 7-byte padding */ /* total size (bytes): 24 */ } Note how the offset information is now extended to also include the first bit of the bitfield. `ptype[/FLAGS] [ARG]' `ptype' accepts the same arguments as `whatis', but prints a detailed description of the type, instead of just the name of the type. *Note Expressions: Expressions. Contrary to `whatis', `ptype' always unrolls any `typedef's in its argument declaration, whether the argument is a variable, expression, or a data type. This means that `ptype' of a variable or an expression will not print literally its type as present in the source code--use `whatis' for that. `typedef's at the pointer or reference targets are also unrolled. Only `typedef's of fields, methods and inner `class typedef's of `struct's, `class'es and `union's are not unrolled even with `ptype'. For example, for this variable declaration: typedef double real_t; struct complex { real_t real; double imag; }; typedef struct complex complex_t; complex_t var; real_t *real_pointer_var; the two commands give this output: (gdb) whatis var type = complex_t (gdb) ptype var type = struct complex { real_t real; double imag; } (gdb) whatis complex_t type = struct complex (gdb) whatis struct complex type = struct complex (gdb) ptype struct complex type = struct complex { real_t real; double imag; } (gdb) whatis real_pointer_var type = real_t * (gdb) ptype real_pointer_var type = double * As with `whatis', using `ptype' without an argument refers to the type of `$', the last value in the value history. Sometimes, programs use opaque data types or incomplete specifications of complex data structure. If the debug information included in the program does not allow GDB to display a full declaration of the data type, it will say `'. For example, given these declarations: struct foo; struct foo *fooptr; but no definition for `struct foo' itself, GDB will say: (gdb) ptype foo $1 = "Incomplete type" is C terminology for data types that are not completely specified. Othertimes, information about a variable's type is completely absent from the debug information included in the program. This most often happens when the program or library where the variable is defined includes no debug information at all. GDB knows the variable exists from inspecting the linker/loader symbol table (e.g., the ELF dynamic symbol table), but such symbols do not contain type information. Inspecting the type of a (global) variable for which GDB has no type information shows: (gdb) ptype var type = *Note no debug info variables: Variables, for how to print the values of such variables. `info types [-q] [REGEXP]' Print a brief description of all types whose names match the regular expression REGEXP (or all types in your program, if you supply no argument). Each complete typename is matched as though it were a complete line; thus, `i type value' gives information on all types in your program whose names include the string `value', but `i type ^value$' gives information only on types whose complete name is `value'. In programs using different languages, GDB chooses the syntax to print the type description according to the `set language' value: using `set language auto' (see *Note Set Language Automatically: Automatically.) means to use the language of the type, other values mean to use the manually specified language (see *Note Set Language Manually: Manually.). This command differs from `ptype' in two ways: first, like `whatis', it does not print a detailed description; second, it lists all source files and line numbers where a type is defined. The output from `into types' is proceeded with a header line describing what types are being listed. The optional flag `-q', which stands for `quiet', disables printing this header information. `info type-printers' Versions of GDB that ship with Python scripting enabled may have "type printers" available. When using `ptype' or `whatis', these printers are consulted when the name of a type is needed. *Note Type Printing API::, for more information on writing type printers. `info type-printers' displays all the available type printers. `enable type-printer NAME...' `disable type-printer NAME...' These commands can be used to enable or disable type printers. `info scope LOCSPEC' List all the variables local to the lexical scope of the code location that results from resolving LOCSPEC. *Note Location Specifications::, for details about supported forms of LOCSPEC. For example: (gdb) info scope command_line_handler Scope for command_line_handler: Symbol rl is an argument at stack/frame offset 8, length 4. Symbol linebuffer is in static storage at address 0x150a18, length 4. Symbol linelength is in static storage at address 0x150a1c, length 4. Symbol p is a local variable in register $esi, length 4. Symbol p1 is a local variable in register $ebx, length 4. Symbol nline is a local variable in register $edx, length 4. Symbol repeat is a local variable at frame offset -8, length 4. This command is especially useful for determining what data to collect during a "trace experiment", see *Note collect: Tracepoint Actions. `info source' Show information about the current source file--that is, the source file for the function containing the current point of execution: * the name of the source file, and the directory containing it, * the directory it was compiled in, * its length, in lines, * which programming language it is written in, * if the debug information provides it, the program that compiled the file (which may include, e.g., the compiler version and command line arguments), * whether the executable includes debugging information for that file, and if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and * whether the debugging information includes information about preprocessor macros. `info sources [-dirname | -basename] [--] [REGEXP]' With no options `info sources' prints the names of all source files in your program for which there is debugging information. The source files are presented based on a list of object files (executables and libraries) currently loaded into GDB. For each object file all of the associated source files are listed. Each source file will only be printed once for each object file, but a single source file can be repeated in the output if it is part of multiple object files. If the optional REGEXP is provided, then only source files that match the regular expression will be printed. The matching is case-sensitive, except on operating systems that have case-insensitive filesystem (e.g., MS-Windows). `--' can be used before REGEXP to prevent GDB interpreting REGEXP as a command option (e.g. if REGEXP starts with `-'). By default, the REGEXP is used to match anywhere in the filename. If `-dirname', only files having a dirname matching REGEXP are shown. If `-basename', only files having a basename matching REGEXP are shown. It is possible that an object file may be printed in the list with no associated source files. This can happen when either no source files match REGEXP, or, the object file was compiled without debug information and so GDB is unable to find any source file names. `info functions [-q] [-n]' Print the names and data types of all defined functions. Similarly to `info types', this command groups its output by source files and annotates each function definition with its source line number. In programs using different languages, GDB chooses the syntax to print the function name and type according to the `set language' value: using `set language auto' (see *Note Set Language Automatically: Automatically.) means to use the language of the function, other values mean to use the manually specified language (see *Note Set Language Manually: Manually.). The `-n' flag excludes "non-debugging symbols" from the results. A non-debugging symbol is a symbol that comes from the executable's symbol table, not from the debug information (for example, DWARF) associated with the executable. The optional flag `-q', which stands for `quiet', disables printing header information and messages explaining why no functions have been printed. `info functions [-q] [-n] [-t TYPE_REGEXP] [REGEXP]' Like `info functions', but only print the names and data types of the functions selected with the provided regexp(s). If REGEXP is provided, print only the functions whose names match the regular expression REGEXP. Thus, `info fun step' finds all functions whose names include `step'; `info fun ^step' finds those whose names start with `step'. If a function name contains characters that conflict with the regular expression language (e.g. `operator*()'), they may be quoted with a backslash. If TYPE_REGEXP is provided, print only the functions whose types, as printed by the `whatis' command, match the regular expression TYPE_REGEXP. If TYPE_REGEXP contains space(s), it should be enclosed in quote characters. If needed, use backslash to escape the meaning of special characters or quotes. Thus, `info fun -t '^int ('' finds the functions that return an integer; `info fun -t '(.*int.*'' finds the functions that have an argument type containing int; `info fun -t '^int (' ^step' finds the functions whose names start with `step' and that return int. If both REGEXP and TYPE_REGEXP are provided, a function is printed only if its name matches REGEXP and its type matches TYPE_REGEXP. `info variables [-q] [-n]' Print the names and data types of all variables that are defined outside of functions (i.e. excluding local variables). The printed variables are grouped by source files and annotated with their respective source line numbers. In programs using different languages, GDB chooses the syntax to print the variable name and type according to the `set language' value: using `set language auto' (see *Note Set Language Automatically: Automatically.) means to use the language of the variable, other values mean to use the manually specified language (see *Note Set Language Manually: Manually.). The `-n' flag excludes non-debugging symbols from the results. The optional flag `-q', which stands for `quiet', disables printing header information and messages explaining why no variables have been printed. `info variables [-q] [-n] [-t TYPE_REGEXP] [REGEXP]' Like `info variables', but only print the variables selected with the provided regexp(s). If REGEXP is provided, print only the variables whose names match the regular expression REGEXP. If TYPE_REGEXP is provided, print only the variables whose types, as printed by the `whatis' command, match the regular expression TYPE_REGEXP. If TYPE_REGEXP contains space(s), it should be enclosed in quote characters. If needed, use backslash to escape the meaning of special characters or quotes. If both REGEXP and TYPE_REGEXP are provided, an argument is printed only if its name matches REGEXP and its type matches TYPE_REGEXP. `info modules [-q] [REGEXP]' List all Fortran modules in the program, or all modules matching the optional regular expression REGEXP. The optional flag `-q', which stands for `quiet', disables printing header information and messages explaining why no modules have been printed. `info module functions [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]' `info module variables [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]' List all functions or variables within all Fortran modules. The set of functions or variables listed can be limited by providing some or all of the optional regular expressions. If MODULE-REGEXP is provided, then only Fortran modules matching MODULE-REGEXP will be searched. Only functions or variables whose type matches the optional regular expression TYPE-REGEXP will be listed. And only functions or variables whose name matches the optional regular expression REGEXP will be listed. The optional flag `-q', which stands for `quiet', disables printing header information and messages explaining why no functions or variables have been printed. `info main' Print the name of the starting function of the program. This serves primarily Fortran programs, which have a user-supplied name for the main subroutine. `info classes' `info classes REGEXP' Display all Objective-C classes in your program, or (with the REGEXP argument) all those matching a particular regular expression. `info selectors' `info selectors REGEXP' Display all Objective-C selectors in your program, or (with the REGEXP argument) all those matching a particular regular expression. `set opaque-type-resolution on' Tell GDB to resolve opaque types. An opaque type is a type declared as a pointer to a `struct', `class', or `union'--for example, `struct MyType *'--that is used in one source file although the full declaration of `struct MyType' is in another source file. The default is on. A change in the setting of this subcommand will not take effect until the next time symbols for a file are loaded. `set opaque-type-resolution off' Tell GDB not to resolve opaque types. In this case, the type is printed as follows: {} `show opaque-type-resolution' Show whether opaque types are resolved or not. `set print symbol-loading' `set print symbol-loading full' `set print symbol-loading brief' `set print symbol-loading off' The `set print symbol-loading' command allows you to control the printing of messages when GDB loads symbol information. By default a message is printed for the executable and one for each shared library, and normally this is what you want. However, when debugging apps with large numbers of shared libraries these messages can be annoying. When set to `brief' a message is printed for each executable, and when GDB loads a collection of shared libraries at once it will only print one message regardless of the number of shared libraries. When set to `off' no messages are printed. `show print symbol-loading' Show whether messages will be printed when a GDB command entered from the keyboard causes symbol information to be loaded. `maint print symbols [-pc ADDRESS] [FILENAME]' `maint print symbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]' `maint print psymbols [-objfile OBJFILE] [-pc ADDRESS] [--] [FILENAME]' `maint print psymbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]' `maint print msymbols [-objfile OBJFILE] [--] [FILENAME]' Write a dump of debugging symbol data into the file FILENAME or the terminal if FILENAME is unspecified. If `-objfile OBJFILE' is specified, only dump symbols for that objfile. If `-pc ADDRESS' is specified, only dump symbols for the file with code at that address. Note that ADDRESS may be a symbol like `main'. If `-source SOURCE' is specified, only dump symbols for that source file. These commands are used to debug the GDB symbol-reading code. These commands do not modify internal GDB state, therefore `maint print symbols' will only print symbols for already expanded symbol tables. You can use the command `info sources' to find out which files these are. If you use `maint print psymbols' instead, the dump shows information about symbols that GDB only knows partially--that is, symbols defined in files that GDB has skimmed, but not yet read completely. Finally, `maint print msymbols' just dumps "minimal symbols", e.g., "ELF symbols". *Note Commands to Specify Files: Files, for a discussion of how GDB reads symbols (in the description of `symbol-file'). `maint info symtabs [ REGEXP ]' `maint info psymtabs [ REGEXP ]' List the `struct symtab' or `struct partial_symtab' structures whose names match REGEXP. If REGEXP is not given, list them all. The output includes expressions which you can copy into a GDB debugging this one to examine a particular structure in more detail. For example: (gdb) maint info psymtabs dwarf2read { objfile /home/gnu/build/gdb/gdb ((struct objfile *) 0x82e69d0) { psymtab /home/gnu/src/gdb/dwarf2read.c ((struct partial_symtab *) 0x8474b10) readin no fullname (null) text addresses 0x814d3c8 -- 0x8158074 globals (* (struct partial_symbol **) 0x8507a08 @@ 9) statics (* (struct partial_symbol **) 0x40e95b78 @@ 2882) dependencies (none) } } (gdb) maint info symtabs (gdb) We see that there is one partial symbol table whose filename contains the string `dwarf2read', belonging to the `gdb' executable; and we see that GDB has not read in any symtabs yet at all. If we set a breakpoint on a function, that will cause GDB to read the symtab for the compilation unit containing that function: (gdb) break dwarf2_psymtab_to_symtab Breakpoint 1 at 0x814e5da: file /home/gnu/src/gdb/dwarf2read.c, line 1574. (gdb) maint info symtabs { objfile /home/gnu/build/gdb/gdb ((struct objfile *) 0x82e69d0) { symtab /home/gnu/src/gdb/dwarf2read.c ((struct symtab *) 0x86c1f38) dirname (null) fullname (null) blockvector ((struct blockvector *) 0x86c1bd0) (primary) linetable ((struct linetable *) 0x8370fa0) debugformat DWARF 2 } } (gdb) `maint info line-table [ REGEXP ]' List the `struct linetable' from all `struct symtab' instances whose name matches REGEXP. If REGEXP is not given, list the `struct linetable' from all `struct symtab'. For example: (gdb) maint info line-table objfile: /home/gnu/build/a.out ((struct objfile *) 0x6120000e0d40) compunit_symtab: simple.cpp ((struct compunit_symtab *) 0x6210000ff450) symtab: /home/gnu/src/simple.cpp ((struct symtab *) 0x6210000ff4d0) linetable: ((struct linetable *) 0x62100012b760): INDEX LINE ADDRESS IS-STMT PROLOGUE-END EPILOGUE-BEGIN 0 3 0x0000000000401110 Y 1 4 0x0000000000401114 Y Y Y 2 9 0x0000000000401120 Y 3 10 0x0000000000401124 Y Y 4 10 0x0000000000401129 Y Y 5 15 0x0000000000401130 Y 6 16 0x0000000000401134 Y Y 7 16 0x0000000000401139 8 21 0x0000000000401140 Y Y 9 22 0x000000000040114f Y Y 10 22 0x0000000000401154 Y 11 END 0x000000000040115a Y The `IS-STMT' column indicates if the address is a recommended breakpoint location to represent a line or a statement. The `PROLOGUE-END' column indicates that a given address is an adequate place to set a breakpoint at the first instruction following a function prologue. The `EPILOGUE-BEGIN' column indicates that a given address marks the point where a block's frame is destroyed, making local variables hard or impossible to find. `set always-read-ctf [on|off]' `show always-read-ctf' When off, CTF debug info is only read if DWARF debug info is not present. When on, CTF debug info is read regardless of whether DWARF debug info is present. The default value is off. `maint set symbol-cache-size SIZE' Set the size of the symbol cache to SIZE. The default size is intended to be good enough for debugging most applications. This option exists to allow for experimenting with different sizes. `maint show symbol-cache-size' Show the size of the symbol cache. `maint print symbol-cache' Print the contents of the symbol cache. This is useful when debugging symbol cache issues. `maint print symbol-cache-statistics' Print symbol cache usage statistics. This helps determine how well the cache is being utilized. `maint flush symbol-cache' `maint flush-symbol-cache' Flush the contents of the symbol cache, all entries are removed. This command is useful when debugging the symbol cache. It is also useful when collecting performance data. The command `maint flush-symbol-cache' is deprecated in favor of `maint flush symbol-cache'.. `maint set ignore-prologue-end-flag [on|off]' Enable or disable the use of the `PROLOGUE-END' flag from the line-table. When `off' (the default), GDB uses the `PROLOGUE-END' flag to place breakpoints past the end of a function prologue. When `on', GDB ignores the flag and relies on prologue analyzers to skip function prologues. `maint show ignore-prologue-end-flag' Show whether GDB will ignore the `PROLOGUE-END' flag.  File: gdb.info, Node: Altering, Next: GDB Files, Prev: Symbols, Up: Top 17 Altering Execution ********************* Once you think you have found an error in your program, you might want to find out for certain whether correcting the apparent error would lead to correct results in the rest of the run. You can find the answer by experiment, using the GDB features for altering execution of the program. For example, you can store new values into variables or memory locations, give your program a signal, restart it at a different address, or even return prematurely from a function. * Menu: * Assignment:: Assignment to variables * Jumping:: Continuing at a different address * Signaling:: Giving your program a signal * Returning:: Returning from a function * Calling:: Calling your program's functions * Patching:: Patching your program * Compiling and Injecting Code:: Compiling and injecting code in GDB  File: gdb.info, Node: Assignment, Next: Jumping, Up: Altering 17.1 Assignment to Variables ============================ To alter the value of a variable, evaluate an assignment expression. *Note Expressions: Expressions. For example, print x=4 stores the value 4 into the variable `x', and then prints the value of the assignment expression (which is 4). *Note Using GDB with Different Languages: Languages, for more information on operators in supported languages. If you are not interested in seeing the value of the assignment, use the `set' command instead of the `print' command. `set' is really the same as `print' except that the expression's value is not printed and is not put in the value history (*note Value History: Value History.). The expression is evaluated only for its effects. If the beginning of the argument string of the `set' command appears identical to a `set' subcommand, use the `set variable' command instead of just `set'. This command is identical to `set' except for its lack of subcommands. For example, if your program has a variable `width', you get an error if you try to set a new value with just `set width=13', because GDB has the command `set width': (gdb) whatis width type = double (gdb) p width $4 = 13 (gdb) set width=47 Invalid syntax in expression. The invalid expression, of course, is `=47'. In order to actually set the program's variable `width', use (gdb) set var width=47 Because the `set' command has many subcommands that can conflict with the names of program variables, it is a good idea to use the `set variable' command instead of just `set'. For example, if your program has a variable `g', you run into problems if you try to set a new value with just `set g=4', because GDB has the command `set gnutarget', abbreviated `set g': (gdb) whatis g type = double (gdb) p g $1 = 1 (gdb) set g=4 (gdb) p g $2 = 1 (gdb) r The program being debugged has been started already. Start it from the beginning? (y or n) y Starting program: /home/smith/cc_progs/a.out "/home/smith/cc_progs/a.out": can't open to read symbols: Invalid bfd target. (gdb) show g The current BFD target is "=4". The program variable `g' did not change, and you silently set the `gnutarget' to an invalid value. In order to set the variable `g', use (gdb) set var g=4 GDB allows more implicit conversions in assignments than C; you can freely store an integer value into a pointer variable or vice versa, and you can convert any structure to any other structure that is the same length or shorter. To store values into arbitrary places in memory, use the `{...}' construct to generate a value of specified type at a specified address (*note Expressions: Expressions.). For example, `{int}0x83040' refers to memory location `0x83040' as an integer (which implies a certain size and representation in memory), and set {int}0x83040 = 4 stores the value 4 into that memory location.  File: gdb.info, Node: Jumping, Next: Signaling, Prev: Assignment, Up: Altering 17.2 Continuing at a Different Address ====================================== Ordinarily, when you continue your program, you do so at the place where it stopped, with the `continue' command. You can instead continue at an address of your own choosing, with the following commands: `jump LOCSPEC' `j LOCSPEC' Resume execution at the address of the code location that results from resolving LOCSPEC. *Note Location Specifications::, for a description of the different forms of LOCSPEC. If LOCSPEC resolves to more than one address, those outside the current compilation unit are ignored. If considering just the addresses in the current compilation unit still doesn't yield a unique address, the command aborts before jumping. Execution stops again immediately if there is a breakpoint there. It is common practice to use the `tbreak' command in conjunction with `jump'. *Note Setting Breakpoints: Set Breaks. The `jump' command does not change the current stack frame, or the stack pointer, or the contents of any memory location or any register other than the program counter. If LOCSPEC resolves to an address in a different function from the one currently executing, the results may be bizarre if the two functions expect different patterns of arguments or of local variables. For this reason, the `jump' command requests confirmation if the jump address is not in the function currently executing. However, even bizarre results are predictable if you are well acquainted with the machine-language code of your program. On many systems, you can get much the same effect as the `jump' command by storing a new value into the register `$pc'. The difference is that this does not start your program running; it only changes the address of where it _will_ run when you continue. For example, set $pc = 0x485 makes the next `continue' command or stepping command execute at address `0x485', rather than at the address where your program stopped. *Note Continuing and Stepping: Continuing and Stepping. However, writing directly to `$pc' will only change the value of the program-counter register, while using `jump' will ensure that any additional auxiliary state is also updated. For example, on SPARC, `jump' will update both `$pc' and `$npc' registers prior to resuming execution. When using the approach of writing directly to `$pc' it is your job to also update the `$npc' register. The most common occasion to use the `jump' command is to back up--perhaps with more breakpoints set--over a portion of a program that has already executed, in order to examine its execution in more detail.  File: gdb.info, Node: Signaling, Next: Returning, Prev: Jumping, Up: Altering 17.3 Giving your Program a Signal ================================= `signal SIGNAL' Resume execution where your program is stopped, but immediately give it the signal SIGNAL. The SIGNAL can be the name or the number of a signal. For example, on many systems `signal 2' and `signal SIGINT' are both ways of sending an interrupt signal. Alternatively, if SIGNAL is zero, continue execution without giving a signal. This is useful when your program stopped on account of a signal and would ordinarily see the signal when resumed with the `continue' command; `signal 0' causes it to resume without a signal. _Note:_ When resuming a multi-threaded program, SIGNAL is delivered to the currently selected thread, not the thread that last reported a stop. This includes the situation where a thread was stopped due to a signal. So if you want to continue execution suppressing the signal that stopped a thread, you should select that same thread before issuing the `signal 0' command. If you issue the `signal 0' command with another thread as the selected one, GDB detects that and asks for confirmation. Invoking the `signal' command is not the same as invoking the `kill' utility from the shell. Sending a signal with `kill' causes GDB to decide what to do with the signal depending on the signal handling tables (*note Signals::). The `signal' command passes the signal directly to your program. `signal' does not repeat when you press a second time after executing the command. `queue-signal SIGNAL' Queue SIGNAL to be delivered immediately to the current thread when execution of the thread resumes. The SIGNAL can be the name or the number of a signal. For example, on many systems `signal 2' and `signal SIGINT' are both ways of sending an interrupt signal. The handling of the signal must be set to pass the signal to the program, otherwise GDB will report an error. You can control the handling of signals from GDB with the `handle' command (*note Signals::). Alternatively, if SIGNAL is zero, any currently queued signal for the current thread is discarded and when execution resumes no signal will be delivered. This is useful when your program stopped on account of a signal and would ordinarily see the signal when resumed with the `continue' command. This command differs from the `signal' command in that the signal is just queued, execution is not resumed. And `queue-signal' cannot be used to pass a signal whose handling state has been set to `nopass' (*note Signals::). *Note stepping into signal handlers::, for information on how stepping commands behave when the thread has a signal queued.  File: gdb.info, Node: Returning, Next: Calling, Prev: Signaling, Up: Altering 17.4 Returning from a Function ============================== `return' `return EXPRESSION' You can cancel execution of a function call with the `return' command. If you give an EXPRESSION argument, its value is used as the function's return value. When you use `return', GDB discards the selected stack frame (and all frames within it). You can think of this as making the discarded frame return prematurely. If you wish to specify a value to be returned, give that value as the argument to `return'. This pops the selected stack frame (*note Selecting a Frame: Selection.), and any other frames inside of it, leaving its caller as the innermost remaining frame. That frame becomes selected. The specified value is stored in the registers used for returning values of functions. The `return' command does not resume execution; it leaves the program stopped in the state that would exist if the function had just returned. In contrast, the `finish' command (*note Continuing and Stepping: Continuing and Stepping.) resumes execution until the selected stack frame returns naturally. GDB needs to know how the EXPRESSION argument should be set for the inferior. The concrete registers assignment depends on the OS ABI and the type being returned by the selected stack frame. For example it is common for OS ABI to return floating point values in FPU registers while integer values in CPU registers. Still some ABIs return even floating point values in CPU registers. Larger integer widths (such as `long long int') also have specific placement rules. GDB already knows the OS ABI from its current target so it needs to find out also the type being returned to make the assignment into the right register(s). Normally, the selected stack frame has debug info. GDB will always use the debug info instead of the implicit type of EXPRESSION when the debug info is available. For example, if you type `return -1', and the function in the current stack frame is declared to return a `long long int', GDB transparently converts the implicit `int' value of -1 into a `long long int': Breakpoint 1, func () at gdb.base/return-nodebug.c:29 29 return 31; (gdb) return -1 Make func return now? (y or n) y #0 0x004004f6 in main () at gdb.base/return-nodebug.c:43 43 printf ("result=%lld\n", func ()); (gdb) However, if the selected stack frame does not have a debug info, e.g., if the function was compiled without debug info, GDB has to find out the type to return from user. Specifying a different type by mistake may set the value in different inferior registers than the caller code expects. For example, typing `return -1' with its implicit type `int' would set only a part of a `long long int' result for a debug info less function (on 32-bit architectures). Therefore the user is required to specify the return type by an appropriate cast explicitly: Breakpoint 2, 0x0040050b in func () (gdb) return -1 Return value type not available for selected stack frame. Please use an explicit cast of the value to return. (gdb) return (long long int) -1 Make selected stack frame return now? (y or n) y #0 0x00400526 in main () (gdb)  File: gdb.info, Node: Calling, Next: Patching, Prev: Returning, Up: Altering 17.5 Calling Program Functions ============================== `print EXPR' Evaluate the expression EXPR and display the resulting value. The expression may include calls to functions in the program being debugged. `call EXPR' Evaluate the expression EXPR without displaying `void' returned values. You can use this variant of the `print' command if you want to execute a function from your program that does not return anything (a.k.a. "a void function"), but without cluttering the output with `void' returned values that GDB will otherwise print. If the result is not void, it is printed and saved in the value history. It is possible for the function you call via the `print' or `call' command to generate a signal (e.g., if there's a bug in the function, or if you passed it incorrect arguments). What happens in that case is controlled by the `set unwind-on-signal' command. Similarly, with a C++ program it is possible for the function you call via the `print' or `call' command to generate an exception that is not handled due to the constraints of the dummy frame. In this case, any exception that is raised in the frame, but has an out-of-frame exception handler will not be found. GDB builds a dummy-frame for the inferior function call, and the unwinder cannot seek for exception handlers outside of this dummy-frame. What happens in that case is controlled by the `set unwind-on-terminating-exception' command. `set unwind-on-signal' Set unwinding of the stack if a signal is received while in a function that GDB called in the program being debugged. If set to on, GDB unwinds the stack it created for the call and restores the context to what it was before the call. If set to off (the default), GDB stops in the frame where the signal was received. The command `set unwindonsignal' is an alias for this command, and is maintained for backward compatibility. `show unwind-on-signal' Show the current setting of stack unwinding in the functions called by GDB. The command `show unwindonsignal' is an alias for this command, and is maintained for backward compatibility. `set unwind-on-terminating-exception' Set unwinding of the stack if a C++ exception is raised, but left unhandled while in a function that GDB called in the program being debugged. If set to on (the default), GDB unwinds the stack it created for the call and restores the context to what it was before the call. If set to off, GDB the exception is delivered to the default C++ exception handler and the inferior terminated. `show unwind-on-terminating-exception' Show the current setting of stack unwinding in the functions called by GDB. `set unwind-on-timeout' Set unwinding of the stack if a function called from GDB times out. If set to `off' (the default), GDB stops in the frame where the timeout occurred. If set to `on', GDB unwinds the stack it created for the call and restores the context to what it was before the call. `show unwind-on-timeout' Show whether GDB will unwind the stack if a function called from GDB times out. `set may-call-functions' Set permission to call functions in the program. This controls whether GDB will attempt to call functions in the program, such as with expressions in the `print' command. It defaults to `on'. To call a function in the program, GDB has to temporarily modify the state of the inferior. This has potentially undesired side effects. Also, having GDB call nested functions is likely to be erroneous and may even crash the program being debugged. You can avoid such hazards by forbidding GDB from calling functions in the program being debugged. If calling functions in the program is forbidden, GDB will throw an error when a command (such as printing an expression) starts a function call in the program. `show may-call-functions' Show permission to call functions in the program. When calling a function within a program, it is possible that the program could enter a state from which the called function may never return. If this happens then it is possible to interrupt the function call by typing the interrupt character (often `Ctrl-c'). If a called function is interrupted for any reason, including hitting a breakpoint, or triggering a watchpoint, and the stack is not unwound due to `set unwind-on-terminating-exception on', `set unwind-on-timeout on', or `set unwind-on-signal on' (*note stack unwind settings::), then the dummy-frame, created by GDB to facilitate the call to the program function, will be visible in the backtrace, for example frame `#3' in the following backtrace: (gdb) backtrace #0 0x00007ffff7b3d1e7 in nanosleep () from /lib64/libc.so.6 #1 0x00007ffff7b3d11e in sleep () from /lib64/libc.so.6 #2 0x000000000040113f in deadlock () at test.cc:13 #3 #4 breakpt () at test.cc:20 #5 0x0000000000401151 in main () at test.cc:25 At this point it is possible to examine the state of the inferior just like any other stop. Depending on why the function was interrupted then it may be possible to resume the inferior (using commands like `continue', `step', etc). In this case, when the inferior finally returns to the dummy-frame, GDB will once again halt the inferior. On targets that support asynchronous execution (*note Background Execution::) GDB can place a timeout on any functions called from GDB. If the timeout expires and the function call is still ongoing, then GDB will interrupt the program. If a function called from GDB is interrupted by a timeout, then by default the inferior is left in the frame where the timeout occurred, this behaviour can be adjusted with `set unwind-on-timeout' (*note set unwind-on-timeout::). For targets that don't support asynchronous execution (*note Background Execution::) then timeouts for functions called from GDB are not supported, the timeout settings described below will be treated as `unlimited', meaning GDB will wait indefinitely for function call to complete, unless interrupted by the user using `Ctrl-C'. `set direct-call-timeout SECONDS' Set the timeout used when calling functions in the program to SECONDS, which should be an integer greater than zero, or the special value `unlimited', which indicates no timeout should be used. The default for this setting is `unlimited'. This setting is used when the user calls a function directly from the command prompt, for example with a `call' or `print' command. This setting only works for targets that support asynchronous execution (*note Background Execution::), for any other target the setting is treated as `unlimited'. `show direct-call-timeout' Show the timeout used when calling functions in the program with a `call' or `print' command. It is also possible to call functions within the program from the condition of a conditional breakpoint (*note Break Conditions: Conditions.). A different setting controls the timeout used for function calls made from a breakpoint condition. `set indirect-call-timeout SECONDS' Set the timeout used when calling functions in the program from a breakpoint or watchpoint condition to SECONDS, which should be an integer greater than zero, or the special value `unlimited', which indicates no timeout should be used. The default for this setting is `30' seconds. This setting only works for targets that support asynchronous execution (*note Background Execution::), for any other target the setting is treated as `unlimited'. If a function called from a breakpoint or watchpoint condition times out, then GDB will stop at the point where the timeout occurred. The breakpoint condition evaluation will be abandoned. `show indirect-call-timeout' Show the timeout used when calling functions in the program from a breakpoint or watchpoint condition. 17.5.1 Calling functions with no debug info ------------------------------------------- Sometimes, a function you wish to call is missing debug information. In such case, GDB does not know the type of the function, including the types of the function's parameters. To avoid calling the inferior function incorrectly, which could result in the called function functioning erroneously and even crash, GDB refuses to call the function unless you tell it the type of the function. For prototyped (i.e. ANSI/ISO style) functions, there are two ways to do that. The simplest is to cast the call to the function's declared return type. For example: (gdb) p getenv ("PATH") 'getenv' has unknown return type; cast the call to its declared return type (gdb) p (char *) getenv ("PATH") $1 = 0x7fffffffe7ba "/usr/local/bin:/"... Casting the return type of a no-debug function is equivalent to casting the function to a pointer to a prototyped function that has a prototype that matches the types of the passed-in arguments, and calling that. I.e., the call above is equivalent to: (gdb) p ((char * (*) (const char *)) getenv) ("PATH") and given this prototyped C or C++ function with float parameters: float multiply (float v1, float v2) { return v1 * v2; } these calls are equivalent: (gdb) p (float) multiply (2.0f, 3.0f) (gdb) p ((float (*) (float, float)) multiply) (2.0f, 3.0f) If the function you wish to call is declared as unprototyped (i.e. old K&R style), you must use the cast-to-function-pointer syntax, so that GDB knows that it needs to apply default argument promotions (promote float arguments to double). *Note float promotion: ABI. For example, given this unprototyped C function with float parameters, and no debug info: float multiply_noproto (v1, v2) float v1, v2; { return v1 * v2; } you call it like this: (gdb) p ((float (*) ()) multiply_noproto) (2.0f, 3.0f)  File: gdb.info, Node: Patching, Next: Compiling and Injecting Code, Prev: Calling, Up: Altering 17.6 Patching Programs ====================== By default, GDB opens the file containing your program's executable code (or the corefile) read-only. This prevents accidental alterations to machine code; but it also prevents you from intentionally patching your program's binary. If you'd like to be able to patch the binary, you can specify that explicitly with the `set write' command. For example, you might want to turn on internal debugging flags, or even to make emergency repairs. `set write on' `set write off' If you specify `set write on', GDB opens executable and core files for both reading and writing; if you specify `set write off' (the default), GDB opens them read-only. If you have already loaded a file, you must load it again (using the `exec-file' or `core-file' command) after changing `set write', for your new setting to take effect. `show write' Display whether executable files and core files are opened for writing as well as reading.  File: gdb.info, Node: Compiling and Injecting Code, Prev: Patching, Up: Altering 17.7 Compiling and injecting code in GDB ======================================== GDB supports on-demand compilation and code injection into programs running under GDB. GCC 5.0 or higher built with `libcc1.so' must be installed for this functionality to be enabled. This functionality is implemented with the following commands. `compile code SOURCE-CODE' `compile code -raw - SOURCE-CODE' Compile SOURCE-CODE with the compiler language found as the current language in GDB (*note Languages::). If compilation and injection is not supported with the current language specified in GDB, or the compiler does not support this feature, an error message will be printed. If SOURCE-CODE compiles and links successfully, GDB will load the object-code emitted, and execute it within the context of the currently selected inferior. It is important to note that the compiled code is executed immediately. After execution, the compiled code is removed from GDB and any new types or variables you have defined will be deleted. The command allows you to specify SOURCE-CODE in two ways. The simplest method is to provide a single line of code to the command. E.g.: compile code printf ("hello world\n"); If you specify options on the command line as well as source code, they may conflict. The `--' delimiter can be used to separate options from actual source code. E.g.: compile code -r -- printf ("hello world\n"); Alternatively you can enter source code as multiple lines of text. To enter this mode, invoke the `compile code' command without any text following the command. This will start the multiple-line editor and allow you to type as many lines of source code as required. When you have completed typing, enter `end' on its own line to exit the editor. compile code >printf ("hello\n"); >printf ("world\n"); >end Specifying `-raw', prohibits GDB from wrapping the provided SOURCE-CODE in a callable scope. In this case, you must specify the entry point of the code by defining a function named `_gdb_expr_'. The `-raw' code cannot access variables of the inferior. Using `-raw' option may be needed for example when SOURCE-CODE requires `#include' lines which may conflict with inferior symbols otherwise. `compile file FILENAME' `compile file -raw FILENAME' Like `compile code', but take the source code from FILENAME. compile file /home/user/example.c `compile print [[OPTIONS] --] EXPR' `compile print [[OPTIONS] --] /F EXPR' Compile and execute EXPR with the compiler language found as the current language in GDB (*note Languages::). By default the value of EXPR is printed in a format appropriate to its data type; you can choose a different format by specifying `/F', where F is a letter specifying the format; see *Note Output Formats: Output Formats. The `compile print' command accepts the same options as the `print' command; see *Note print options::. `compile print [[OPTIONS] --]' `compile print [[OPTIONS] --] /F' Alternatively you can enter the expression (source code producing it) as multiple lines of text. To enter this mode, invoke the `compile print' command without any text following the command. This will start the multiple-line editor. The process of compiling and injecting the code can be inspected using: `set debug compile' Turns on or off display of GDB process of compiling and injecting the code. The default is off. `show debug compile' Displays the current state of displaying GDB process of compiling and injecting the code. `set debug compile-cplus-types' Turns on or off the display of C++ type conversion debugging information. The default is off. `show debug compile-cplus-types' Displays the current state of displaying debugging information for C++ type conversion. 17.7.1 Compilation options for the `compile' command ---------------------------------------------------- GDB needs to specify the right compilation options for the code to be injected, in part to make its ABI compatible with the inferior and in part to make the injected code compatible with GDB's injecting process. The options used, in increasing precedence: target architecture and OS options (`gdbarch') These options depend on target processor type and target operating system, usually they specify at least 32-bit (`-m32') or 64-bit (`-m64') compilation option. compilation options recorded in the target GCC (since version 4.7) stores the options used for compilation into `DW_AT_producer' part of DWARF debugging information according to the GCC option `-grecord-gcc-switches'. One has to explicitly specify `-g' during inferior compilation otherwise GCC produces no DWARF. This feature is only relevant for platforms where `-g' produces DWARF by default, otherwise one may try to enforce DWARF by using `-gdwarf-4'. compilation options set by `set compile-args' You can override compilation options using the following command: `set compile-args' Set compilation options used for compiling and injecting code with the `compile' commands. These options override any conflicting ones from the target architecture and/or options stored during inferior compilation. `show compile-args' Displays the current state of compilation options override. This does not show all the options actually used during compilation, use *Note set debug compile:: for that. 17.7.2 Caveats when using the `compile' command ----------------------------------------------- There are a few caveats to keep in mind when using the `compile' command. As the caveats are different per language, the table below highlights specific issues on a per language basis. C code examples and caveats When the language in GDB is set to `C', the compiler will attempt to compile the source code with a `C' compiler. The source code provided to the `compile' command will have much the same access to variables and types as it normally would if it were part of the program currently being debugged in GDB. Below is a sample program that forms the basis of the examples that follow. This program has been compiled and loaded into GDB, much like any other normal debugging session. void function1 (void) { int i = 42; printf ("function 1\n"); } void function2 (void) { int j = 12; function1 (); } int main(void) { int k = 6; int *p; function2 (); return 0; } For the purposes of the examples in this section, the program above has been compiled, loaded into GDB, stopped at the function `main', and GDB is awaiting input from the user. To access variables and types for any program in GDB, the program must be compiled and packaged with debug information. The `compile' command is not an exception to this rule. Without debug information, you can still use the `compile' command, but you will be very limited in what variables and types you can access. So with that in mind, the example above has been compiled with debug information enabled. The `compile' command will have access to all variables and types (except those that may have been optimized out). Currently, as GDB has stopped the program in the `main' function, the `compile' command would have access to the variable `k'. You could invoke the `compile' command and type some source code to set the value of `k'. You can also read it, or do anything with that variable you would normally do in `C'. Be aware that changes to inferior variables in the `compile' command are persistent. In the following example: compile code k = 3; the variable `k' is now 3. It will retain that value until something else in the example program changes it, or another `compile' command changes it. Normal scope and access rules apply to source code compiled and injected by the `compile' command. In the example, the variables `j' and `k' are not accessible yet, because the program is currently stopped in the `main' function, where these variables are not in scope. Therefore, the following command compile code j = 3; will result in a compilation error message. Once the program is continued, execution will bring these variables in scope, and they will become accessible; then the code you specify via the `compile' command will be able to access them. You can create variables and types with the `compile' command as part of your source code. Variables and types that are created as part of the `compile' command are not visible to the rest of the program for the duration of its run. This example is valid: compile code int ff = 5; printf ("ff is %d\n", ff); However, if you were to type the following into GDB after that command has completed: compile code printf ("ff is %d\n'', ff); a compiler error would be raised as the variable `ff' no longer exists. Object code generated and injected by the `compile' command is removed when its execution ends. Caution is advised when assigning to program variables values of variables created by the code submitted to the `compile' command. This example is valid: compile code int ff = 5; k = ff; The value of the variable `ff' is assigned to `k'. The variable `k' does not require the existence of `ff' to maintain the value it has been assigned. However, pointers require particular care in assignment. If the source code compiled with the `compile' command changed the address of a pointer in the example program, perhaps to a variable created in the `compile' command, that pointer would point to an invalid location when the command exits. The following example would likely cause issues with your debugged program: compile code int ff = 5; p = &ff; In this example, `p' would point to `ff' when the `compile' command is executing the source code provided to it. However, as variables in the (example) program persist with their assigned values, the variable `p' would point to an invalid location when the command exists. A general rule should be followed in that you should either assign `NULL' to any assigned pointers, or restore a valid location to the pointer before the command exits. Similar caution must be exercised with any structs, unions, and typedefs defined in `compile' command. Types defined in the `compile' command will no longer be available in the next `compile' command. Therefore, if you cast a variable to a type defined in the `compile' command, care must be taken to ensure that any future need to resolve the type can be achieved. (gdb) compile code static struct a { int a; } v = { 42 }; argv = &v; (gdb) compile code printf ("%d\n", ((struct a *) argv)->a); gdb command line:1:36: error: dereferencing pointer to incomplete type ‘struct a’ Compilation failed. (gdb) compile code struct a { int a; }; printf ("%d\n", ((struct a *) argv)->a); 42 Variables that have been optimized away by the compiler are not accessible to the code submitted to the `compile' command. Access to those variables will generate a compiler error which GDB will print to the console. 17.7.3 Compiler search for the `compile' command ------------------------------------------------ GDB needs to find GCC for the inferior being debugged which may not be obvious for remote targets of different architecture than where GDB is running. Environment variable `PATH' on GDB host is searched for GCC binary matching the target architecture and operating system. This search can be overridden by `set compile-gcc' GDB command below. `PATH' is taken from shell that executed GDB, it is not the value set by GDB command `set environment'). *Note Environment::. Specifically `PATH' is searched for binaries matching regular expression `ARCH(-[^-]*)?-OS-gcc' according to the inferior target being debugged. ARCH is processor name -- multiarch is supported, so for example both `i386' and `x86_64' targets look for pattern `(x86_64|i.86)' and both `s390' and `s390x' targets look for pattern `s390x?'. OS is currently supported only for pattern `linux(-gnu)?'. On Posix hosts the compiler driver GDB needs to find also shared library `libcc1.so' from the compiler. It is searched in default shared library search path (overridable with usual environment variable `LD_LIBRARY_PATH'), unrelated to `PATH' or `set compile-gcc' settings. Contrary to it `libcc1plugin.so' is found according to the installation of the found compiler -- as possibly specified by the `set compile-gcc' command. `set compile-gcc' Set compilation command used for compiling and injecting code with the `compile' commands. If this option is not set (it is set to an empty string), the search described above will occur -- that is the default. `show compile-gcc' Displays the current compile command GCC driver filename. If set, it is the main command `gcc', found usually for example under name `x86_64-linux-gnu-gcc'.  File: gdb.info, Node: GDB Files, Next: Targets, Prev: Altering, Up: Top 18 GDB Files ************ GDB needs to know the file name of the program to be debugged, both in order to read its symbol table and in order to start your program. To debug a core dump of a previous run, you must also tell GDB the name of the core dump file. * Menu: * Files:: Commands to specify files * File Caching:: Information about GDB's file caching * Separate Debug Files:: Debugging information in separate files * MiniDebugInfo:: Debugging information in a special section * Index Files:: Index files speed up GDB * Debug Names:: Extensions to .debug_names * Symbol Errors:: Errors reading symbol files * Data Files:: GDB data files  File: gdb.info, Node: Files, Next: File Caching, Up: GDB Files 18.1 Commands to Specify Files ============================== You may want to specify executable and core dump file names. The usual way to do this is at start-up time, using the arguments to GDB's start-up commands (*note Getting In and Out of GDB: Invocation.). Occasionally it is necessary to change to a different file during a GDB session. Or you may run GDB and forget to specify a file you want to use. Or you are debugging a remote target via `gdbserver' (*note file: Server.). In these situations the GDB commands to specify new files are useful. `file FILENAME' Use FILENAME as the program to be debugged. It is read for its symbols and for the contents of pure memory. It is also the program executed when you use the `run' command. If you do not specify a directory and the file is not found in the GDB working directory, GDB uses the environment variable `PATH' as a list of directories to search, just as the shell does when looking for a program to run. You can change the value of this variable, for both GDB and your program, using the `path' command. The FILENAME argument supports escaping and quoting, see *Note Filenames As Command Arguments: Filename Arguments. You can load unlinked object `.o' files into GDB using the `file' command. You will not be able to "run" an object file, but you can disassemble functions and inspect variables. Also, if the underlying BFD functionality supports it, you could use `gdb -write' to patch object files using this technique. Note that GDB can neither interpret nor modify relocations in this case, so branches and some initialized variables will appear to go to the wrong place. But this feature is still handy from time to time. `file' `file' with no argument makes GDB discard any information it has on both executable file and the symbol table. `exec-file [ FILENAME ]' Specify that the program to be run (but not the symbol table) is found in FILENAME. GDB searches the environment variable `PATH' if necessary to locate your program. Omitting FILENAME means to discard information on the executable file. The FILENAME argument supports escaping and quoting, see *Note Filenames As Command Arguments: Filename Arguments. `symbol-file [ FILENAME [ -o OFFSET ]]' Read symbol table information from file FILENAME. `PATH' is searched when necessary. Use the `file' command to get both symbol table and program to run from the same file. If an optional OFFSET is specified, it is added to the start address of each section in the symbol file. This is useful if the program is relocated at runtime, such as the Linux kernel with kASLR enabled. `symbol-file' with no argument clears out GDB information on your program's symbol table. The `symbol-file' command causes GDB to forget the contents of some breakpoints and auto-display expressions. This is because they may contain pointers to the internal data recording symbols and data types, which are part of the old symbol table data being discarded inside GDB. `symbol-file' does not repeat if you press again after executing it once. The FILENAME argument supports escaping and quoting, see *Note Filenames As Command Arguments: Filename Arguments. When GDB is configured for a particular environment, it understands debugging information in whatever format is the standard generated for that environment; you may use either a GNU compiler, or other compilers that adhere to the local conventions. Best results are usually obtained from GNU compilers; for example, using `GCC' you can generate debugging information for optimized code. For most kinds of object files, with the exception of old SVR3 systems using COFF, the `symbol-file' command does not normally read the symbol table in full right away. Instead, it scans the symbol table quickly to find which source files and which symbols are present. The details are read later, one source file at a time, as they are needed. The purpose of this two-stage reading strategy is to make GDB start up faster. For the most part, it is invisible except for occasional pauses while the symbol table details for a particular source file are being read. (The `set verbose' command can turn these pauses into messages if desired. *Note Optional Warnings and Messages: Messages/Warnings.) We have not implemented the two-stage strategy for COFF yet. When the symbol table is stored in COFF format, `symbol-file' reads the symbol table data in full right away. Note that "stabs-in-COFF" still does the two-stage strategy, since the debug info is actually in stabs format. `symbol-file [ -readnow ] FILENAME' `file [ -readnow ] FILENAME' You can override the GDB two-stage strategy for reading symbol tables by using the `-readnow' option with any of the commands that load symbol table information, if you want to be sure GDB has the entire symbol table available. `symbol-file [ -readnever ] FILENAME' `file [ -readnever ] FILENAME' You can instruct GDB to never read the symbolic information contained in FILENAME by using the `-readnever' option. *Note --readnever::. `core-file [FILENAME]' `core' Specify the whereabouts of a core dump file to be used as the "contents of memory". Traditionally, core files contain only some parts of the address space of the process that generated them; GDB can access the executable file itself for other parts. `core-file' with no argument specifies that no core file is to be used. Note that the core file is ignored when your program is actually running under GDB. So, if you have been running your program and you wish to debug a core file instead, you must kill the subprocess in which the program is running. To do this, use the `kill' command (*note Killing the Child Process: Kill Process.). `add-symbol-file FILENAME [ -readnow | -readnever ] [ -o OFFSET ] [ TEXTADDRESS ] [ -s SECTION ADDRESS ... ]' The `add-symbol-file' command reads additional symbol table information from the file FILENAME. You would use this command when FILENAME has been dynamically loaded (by some other means) into the program that is running. The TEXTADDRESS parameter gives the memory address at which the file's text section has been loaded. You can additionally specify the base address of other sections using an arbitrary number of `-s SECTION ADDRESS' pairs. If a section is omitted, GDB will use its default addresses as found in FILENAME. Any ADDRESS or TEXTADDRESS can be given as an expression. If an optional OFFSET is specified, it is added to the start address of each section, except those for which the address was specified explicitly. The symbol table of the file FILENAME is added to the symbol table originally read with the `symbol-file' command. You can use the `add-symbol-file' command any number of times; the new symbol data thus read is kept in addition to the old. The FILENAME argument supports escaping and quoting, see *Note Filenames As Command Arguments: Filename Arguments. Changes can be reverted using the command `remove-symbol-file'. Although FILENAME is typically a shared library file, an executable file, or some other object file which has been fully relocated for loading into a process, you can also load symbolic information from relocatable `.o' files, as long as: * the file's symbolic information refers only to linker symbols defined in that file, not to symbols defined by other object files, * every section the file's symbolic information refers to has actually been loaded into the inferior, as it appears in the file, and * you can determine the address at which every section was loaded, and provide these to the `add-symbol-file' command. Some embedded operating systems, like Sun Chorus and VxWorks, can load relocatable files into an already running program; such systems typically make the requirements above easy to meet. However, it's important to recognize that many native systems use complex link procedures (`.linkonce' section factoring and C++ constructor table assembly, for example) that make the requirements difficult to meet. In general, one cannot assume that using `add-symbol-file' to read a relocatable object file's symbolic information will have the same effect as linking the relocatable object file into the program in the normal way. `add-symbol-file' does not repeat if you press after using it. `remove-symbol-file FILENAME' `remove-symbol-file -a ADDRESS' Remove a symbol file added via the `add-symbol-file' command. The file to remove can be identified by its FILENAME or by an ADDRESS that lies within the boundaries of this symbol file in memory. Example: (gdb) add-symbol-file /home/user/gdb/mylib.so 0x7ffff7ff9480 add symbol table from file "/home/user/gdb/mylib.so" at .text_addr = 0x7ffff7ff9480 (y or n) y Reading symbols from /home/user/gdb/mylib.so... (gdb) remove-symbol-file -a 0x7ffff7ff9480 Remove symbol table from file "/home/user/gdb/mylib.so"? (y or n) y (gdb) `remove-symbol-file' does not repeat if you press after using it. The FILENAME argument supports escaping and quoting, see *Note Filenames As Command Arguments: Filename Arguments. `add-symbol-file-from-memory ADDRESS' Load symbols from the given ADDRESS in a dynamically loaded object file whose image is mapped directly into the inferior's memory. For example, the Linux kernel maps a `syscall DSO' into each process's address space; this DSO provides kernel-specific code for some system calls. The argument can be any expression whose evaluation yields the address of the file's shared object file header. For this command to work, you must have used `symbol-file' or `exec-file' commands in advance. `section SECTION ADDR' The `section' command changes the base address of the named SECTION of the exec file to ADDR. This can be used if the exec file does not contain section addresses, (such as in the `a.out' format), or when the addresses specified in the file itself are wrong. Each section must be changed separately. The `info files' command, described below, lists all the sections and their addresses. `info files' `info target' `info files' and `info target' are synonymous; both print the current target (*note Specifying a Debugging Target: Targets.), including the names of the executable and core dump files currently in use by GDB, and the files from which symbols were loaded. The command `help target' lists all possible targets rather than current ones. `maint info sections [-all-objects] [FILTER-LIST]' Another command that can give you extra information about program sections is `maint info sections'. In addition to the section information displayed by `info files', this command displays the flags and file offset of each section in the executable and core dump files. When `-all-objects' is passed then sections from all loaded object files, including shared libraries, are printed. The optional FILTER-LIST is a space separated list of filter keywords. Sections that match any one of the filter criteria will be printed. There are two types of filter: `SECTION-NAME' Display information about any section named SECTION-NAME. `SECTION-FLAG' Display information for any section with SECTION-FLAG. The section flags that GDB currently knows about are: `ALLOC' Section will have space allocated in the process when loaded. Set for all sections except those containing debug information. `LOAD' Section will be loaded from the file into the child process memory. Set for pre-initialized code and data, clear for `.bss' sections. `RELOC' Section needs to be relocated before loading. `READONLY' Section cannot be modified by the child process. `CODE' Section contains executable code only. `DATA' Section contains data only (no executable code). `ROM' Section will reside in ROM. `CONSTRUCTOR' Section contains data for constructor/destructor lists. `HAS_CONTENTS' Section is not empty. `NEVER_LOAD' An instruction to the linker to not output the section. `COFF_SHARED_LIBRARY' A notification to the linker that the section contains COFF shared library information. `IS_COMMON' Section contains common symbols. `maint info target-sections' This command prints GDB's internal section table. For each target GDB maintains a table containing the allocatable sections from all currently mapped objects, along with information about where the section is mapped. `set trust-readonly-sections on' Tell GDB that readonly sections in your object file really are read-only (i.e. that their contents will not change). In that case, GDB can fetch values from these sections out of the object file, rather than from the target program. For some targets (notably embedded ones), this can be a significant enhancement to debugging performance. The default is off. `set trust-readonly-sections off' Tell GDB not to trust readonly sections. This means that the contents of the section might change while the program is running, and must therefore be fetched from the target when needed. `show trust-readonly-sections' Show the current setting of trusting readonly sections. All file-specifying commands allow both absolute and relative file names as arguments. GDB always converts the file name to an absolute file name and remembers it that way. GDB supports GNU/Linux, MS-Windows, SunOS, Darwin/Mach-O, SVr4, IBM RS/6000 AIX, QNX Neutrino, FDPIC (FR-V), and DSBT (TIC6X) shared libraries. On MS-Windows GDB must be linked with the Expat library to support shared libraries. *Note Expat::. GDB automatically loads symbol definitions from shared libraries when you use the `run' command, or when you examine a core file. (Before you issue the `run' command, GDB does not understand references to a function in a shared library, however--unless you are debugging a core file). There are times, however, when you may wish to not automatically load symbol definitions from shared libraries, such as when they are particularly large or there are many of them. To control the automatic loading of shared library symbols, use the commands: `set auto-solib-add MODE' If MODE is `on', symbols from all shared object libraries will be loaded automatically when the inferior begins execution, you attach to an independently started inferior, or when the dynamic linker informs GDB that a new library has been loaded. If MODE is `off', symbols must be loaded manually, using the `sharedlibrary' command. The default value is `on'. If your program uses lots of shared libraries with debug info that takes large amounts of memory, you can decrease the GDB memory footprint by preventing it from automatically loading the symbols from shared libraries. To that end, type `set auto-solib-add off' before running the inferior, then load each library whose debug symbols you do need with `sharedlibrary REGEXP', where REGEXP is a regular expression that matches the libraries whose symbols you want to be loaded. `show auto-solib-add' Display the current autoloading mode. To explicitly load shared library symbols, use the `sharedlibrary' command: `info share REGEX' `info sharedlibrary REGEX' Print the names of the shared libraries which are currently loaded that match REGEX. If REGEX is omitted then print all shared libraries that are loaded. `info dll REGEX' This is an alias of `info sharedlibrary'. `sharedlibrary REGEX' `share REGEX' Load shared object library symbols for files matching a Unix regular expression. As with files loaded automatically, it only loads shared libraries required by your program for a core file or after typing `run'. If REGEX is omitted all shared libraries required by your program are loaded. `nosharedlibrary' Unload all shared object library symbols. This discards all symbols that have been loaded from all shared libraries. Symbols from shared libraries that were loaded by explicit user requests are not discarded. Sometimes you may wish that GDB stops and gives you control when any of shared library events happen. The best way to do this is to use `catch load' and `catch unload' (*note Set Catchpoints::). GDB also supports the `set stop-on-solib-events' command for this. This command exists for historical reasons. It is less useful than setting a catchpoint, because it does not allow for conditions or commands as a catchpoint does. `set stop-on-solib-events' This command controls whether GDB should give you control when the dynamic linker notifies it about some shared library event. The most common event of interest is loading or unloading of a new shared library. `show stop-on-solib-events' Show whether GDB stops and gives you control when shared library events happen. Shared libraries are also supported in many cross or remote debugging configurations. GDB needs to have access to the target's libraries; this can be accomplished either by providing copies of the libraries on the host system, or by asking GDB to automatically retrieve the libraries from the target. If copies of the target libraries are provided, they need to be the same as the target libraries, although the copies on the target can be stripped as long as the copies on the host are not. For remote debugging, you need to tell GDB where the target libraries are, so that it can load the correct copies--otherwise, it may try to load the host's libraries. GDB has two variables to specify the search directories for target libraries. `set sysroot PATH' Use PATH as the system root for the program being debugged. Any absolute shared library paths will be prefixed with PATH; many runtime loaders store the absolute paths to the shared library in the target program's memory. When starting processes remotely, and when attaching to already-running processes (local or remote), their executable filenames will be prefixed with PATH if reported to GDB as absolute by the operating system. If you use `set sysroot' to find executables and shared libraries, they need to be laid out in the same way that they are on the target, with e.g. a `/bin', `/lib' and `/usr/lib' hierarchy under PATH. If PATH starts with the sequence `target:' and the target system is remote then GDB will retrieve the target binaries from the remote system. This is only supported when using a remote target that supports the `remote get' command (*note Sending files to a remote system: File Transfer.). The part of PATH following the initial `target:' (if present) is used as system root prefix on the remote file system. If PATH starts with the sequence `remote:' this is converted to the sequence `target:' by `set sysroot'(1). If you want to specify a local system root using a directory that happens to be named `target:' or `remote:', you need to use some equivalent variant of the name like `./target:'. For targets with an MS-DOS based filesystem, such as MS-Windows, GDB tries prefixing a few variants of the target absolute file name with PATH. But first, on Unix hosts, GDB converts all backslash directory separators into forward slashes, because the backslash is not a directory separator on Unix: c:\foo\bar.dll => c:/foo/bar.dll Then, GDB attempts prefixing the target file name with PATH, and looks for the resulting file name in the host file system: c:/foo/bar.dll => /path/to/sysroot/c:/foo/bar.dll If that does not find the binary, GDB tries removing the `:' character from the drive spec, both for convenience, and, for the case of the host file system not supporting file names with colons: c:/foo/bar.dll => /path/to/sysroot/c/foo/bar.dll This makes it possible to have a system root that mirrors a target with more than one drive. E.g., you may want to setup your local copies of the target system shared libraries like so (note `c' vs `z'): `/path/to/sysroot/c/sys/bin/foo.dll' `/path/to/sysroot/c/sys/bin/bar.dll' `/path/to/sysroot/z/sys/bin/bar.dll' and point the system root at `/path/to/sysroot', so that GDB can find the correct copies of both `c:\sys\bin\foo.dll', and `z:\sys\bin\bar.dll'. If that still does not find the binary, GDB tries removing the whole drive spec from the target file name: c:/foo/bar.dll => /path/to/sysroot/foo/bar.dll This last lookup makes it possible to not care about the drive name, if you don't want or need to. The `set solib-absolute-prefix' command is an alias for `set sysroot'. You can set the default system root by using the configure-time `--with-sysroot' option. If the system root is inside GDB's configured binary prefix (set with `--prefix' or `--exec-prefix'), then the default system root will be updated automatically if the installed GDB is moved to a new location. `show sysroot' Display the current executable and shared library prefix. `set solib-search-path PATH' If this variable is set, PATH is a colon-separated list of directories to search for shared libraries. `solib-search-path' is used after `sysroot' fails to locate the library, or if the path to the library is relative instead of absolute. If you want to use `solib-search-path' instead of `sysroot', be sure to set `sysroot' to a nonexistent directory to prevent GDB from finding your host's libraries. `sysroot' is preferred; setting it to a nonexistent directory may interfere with automatic loading of shared library symbols. `show solib-search-path' Display the current shared library search path. `set target-file-system-kind KIND' Set assumed file system kind for target reported file names. Shared library file names as reported by the target system may not make sense as is on the system GDB is running on. For example, when remote debugging a target that has MS-DOS based file system semantics, from a Unix host, the target may be reporting to GDB a list of loaded shared libraries with file names such as `c:\Windows\kernel32.dll'. On Unix hosts, there's no concept of drive letters, so the `c:\' prefix is not normally understood as indicating an absolute file name, and neither is the backslash normally considered a directory separator character. In that case, the native file system would interpret this whole absolute file name as a relative file name with no directory components. This would make it impossible to point GDB at a copy of the remote target's shared libraries on the host using `set sysroot', and impractical with `set solib-search-path'. Setting `target-file-system-kind' to `dos-based' tells GDB to interpret such file names similarly to how the target would, and to map them to file names valid on GDB's native file system semantics. The value of KIND can be `"auto"', in addition to one of the supported file system kinds. In that case, GDB tries to determine the appropriate file system variant based on the current target's operating system (*note Configuring the Current ABI: ABI.). The supported file system settings are: `unix' Instruct GDB to assume the target file system is of Unix kind. Only file names starting the forward slash (`/') character are considered absolute, and the directory separator character is also the forward slash. `dos-based' Instruct GDB to assume the target file system is DOS based. File names starting with either a forward slash, or a drive letter followed by a colon (e.g., `c:'), are considered absolute, and both the slash (`/') and the backslash (`\\') characters are considered directory separators. `auto' Instruct GDB to use the file system kind associated with the target operating system (*note Configuring the Current ABI: ABI.). This is the default. When processing file names provided by the user, GDB frequently needs to compare them to the file names recorded in the program's debug info. Normally, GDB compares just the "base names" of the files as strings, which is reasonably fast even for very large programs. (The base name of a file is the last portion of its name, after stripping all the leading directories.) This shortcut in comparison is based upon the assumption that files cannot have more than one base name. This is usually true, but references to files that use symlinks or similar filesystem facilities violate that assumption. If your program records files using such facilities, or if you provide file names to GDB using symlinks etc., you can set `basenames-may-differ' to `true' to instruct GDB to completely canonicalize each pair of file names it needs to compare. This will make file-name comparisons accurate, but at a price of a significant slowdown. `set basenames-may-differ' Set whether a source file may have multiple base names. `show basenames-may-differ' Show whether a source file may have multiple base names. ---------- Footnotes ---------- (1) Historically the functionality to retrieve binaries from the remote system was provided by prefixing PATH with `remote:'  File: gdb.info, Node: File Caching, Next: Separate Debug Files, Prev: Files, Up: GDB Files 18.2 File Caching ================= To speed up file loading, and reduce memory usage, GDB will reuse the `bfd' objects used to track open files. *Note BFD: (bfd)Top. The following commands allow visibility and control of the caching behavior. `maint info bfds' This prints information about each `bfd' object that is known to GDB. `maint set bfd-sharing' `maint show bfd-sharing' Control whether `bfd' objects can be shared. When sharing is enabled GDB reuses already open `bfd' objects rather than reopening the same file. Turning sharing off does not cause already shared `bfd' objects to be unshared, but all future files that are opened will create a new `bfd' object. Similarly, re-enabling sharing does not cause multiple existing `bfd' objects to be collapsed into a single shared `bfd' object. `set debug bfd-cache LEVEL' Turns on debugging of the bfd cache, setting the level to LEVEL. `show debug bfd-cache' Show the current debugging level of the bfd cache.  File: gdb.info, Node: Separate Debug Files, Next: MiniDebugInfo, Prev: File Caching, Up: GDB Files 18.3 Debugging Information in Separate Files ============================================ GDB allows you to put a program's debugging information in a file separate from the executable itself, in a way that allows GDB to find and load the debugging information automatically. Since debugging information can be very large--sometimes larger than the executable code itself--some systems distribute debugging information for their executables in separate files, which users can install only when they need to debug a problem. GDB supports two ways of specifying the separate debug info file: * The executable contains a "debug link" that specifies the name of the separate debug info file. The separate debug file's name is usually `EXECUTABLE.debug', where EXECUTABLE is the name of the corresponding executable file without leading directories (e.g., `ls.debug' for `/usr/bin/ls'). In addition, the debug link specifies a 32-bit "Cyclic Redundancy Check" (CRC) checksum for the debug file, which GDB uses to validate that the executable and the debug file came from the same build. * The executable contains a "build ID", a unique bit string that is also present in the corresponding debug info file. (This is supported only on some operating systems, when using the ELF or PE file formats for binary files and the GNU Binutils.) For more details about this feature, see the description of the `--build-id' command-line option in *Note Command Line Options: (ld)Options. The debug info file's name is not specified explicitly by the build ID, but can be computed from the build ID, see below. Depending on the way the debug info file is specified, GDB uses two different methods of looking for the debug file: * For the "debug link" method, GDB looks up the named file in the directory of the executable file, then in a subdirectory of that directory named `.debug', and finally under each one of the global debug directories, in a subdirectory whose name is identical to the leading directories of the executable's absolute file name. (On MS-Windows/MS-DOS, the drive letter of the executable's leading directories is converted to a one-letter subdirectory, i.e. `d:/usr/bin/' is converted to `/d/usr/bin/', because Windows filesystems disallow colons in file names.) * For the "build ID" method, GDB looks in the `.build-id' subdirectory of each one of the global debug directories for a file named `NN/NNNNNNNN.debug', where NN are the first 2 hex characters of the build ID bit string, and NNNNNNNN are the rest of the bit string. (Real build ID strings are 32 or more hex characters, not 10.) GDB can automatically query `debuginfod' servers using build IDs in order to download separate debug files that cannot be found locally. For more information see *Note Debuginfod::. So, for example, suppose you ask GDB to debug `/usr/bin/ls', which has a debug link that specifies the file `ls.debug', and a build ID whose value in hex is `abcdef1234'. If the list of the global debug directories includes `/usr/lib/debug', then GDB will look for the following debug information files, in the indicated order: - `/usr/lib/debug/.build-id/ab/cdef1234.debug' - `/usr/bin/ls.debug' - `/usr/bin/.debug/ls.debug' - `/usr/lib/debug/usr/bin/ls.debug'. If the debug file still has not been found and `debuginfod' (*note Debuginfod::) is enabled, GDB will attempt to download the file from `debuginfod' servers. Global debugging info directories default to what is set by GDB configure option `--with-separate-debug-dir' and augmented by the colon-separated list of directories provided via GDB configure option `--additional-debug-dirs'. During GDB run you can also set the global debugging info directories, and view the list GDB is currently using. `set debug-file-directory DIRECTORIES' Set the directories which GDB searches for separate debugging information files to DIRECTORY. Multiple path components can be set concatenating them by a path separator. `show debug-file-directory' Show the directories GDB searches for separate debugging information files. A debug link is a special section of the executable file named `.gnu_debuglink'. The section must contain: * A filename, with any leading directory components removed, followed by a zero byte, * zero to three bytes of padding, as needed to reach the next four-byte boundary within the section, and * a four-byte CRC checksum, stored in the same endianness used for the executable file itself. The checksum is computed on the debugging information file's full contents by the function given below, passing zero as the CRC argument. Any executable file format can carry a debug link, as long as it can contain a section named `.gnu_debuglink' with the contents described above. The build ID is a special section in the executable file (and in other ELF binary files that GDB may consider). This section is often named `.note.gnu.build-id', but that name is not mandatory. It contains unique identification for the built files--the ID remains the same across multiple builds of the same build tree. The default algorithm SHA1 produces 160 bits (40 hexadecimal characters) of the content for the build ID string. The same section with an identical value is present in the original built binary with symbols, in its stripped variant, and in the separate debugging information file. The debugging information file itself should be an ordinary executable, containing a full set of linker symbols, sections, and debugging information. The sections of the debugging information file should have the same names, addresses, and sizes as the original file, but they need not contain any data--much like a `.bss' section in an ordinary executable. The GNU binary utilities (Binutils) package includes the `objcopy' utility that can produce the separated executable / debugging information file pairs using the following commands: objcopy --only-keep-debug foo foo.debug strip -g foo These commands remove the debugging information from the executable file `foo' and place it in the file `foo.debug'. You can use the first, second or both methods to link the two files: * The debug link method needs the following additional command to also leave behind a debug link in `foo': objcopy --add-gnu-debuglink=foo.debug foo Ulrich Drepper's `elfutils' package, starting with version 0.53, contains a version of the `strip' command such that the command `strip foo -f foo.debug' has the same functionality as the two `objcopy' commands and the `ln -s' command above, together. * Build ID gets embedded into the main executable using `ld --build-id' or the GCC counterpart `gcc -Wl,--build-id'. Build ID support plus compatibility fixes for debug files separation are present in GNU binary utilities (Binutils) package since version 2.18. The CRC used in `.gnu_debuglink' is the CRC-32 defined in IEEE 802.3 using the polynomial: x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1 The function is computed byte at a time, taking the least significant bit of each byte first. The initial pattern `0xffffffff' is used, to ensure leading zeros affect the CRC and the final result is inverted to ensure trailing zeros also affect the CRC. _Note:_ This is the same CRC polynomial as used in handling the "Remote Serial Protocol" `qCRC' packet (*note qCRC packet::). However in the case of the Remote Serial Protocol, the CRC is computed _most_ significant bit first, and the result is not inverted, so trailing zeros have no effect on the CRC value. To complete the description, we show below the code of the function which produces the CRC used in `.gnu_debuglink'. Inverting the initially supplied `crc' argument means that an initial call to this function passing in zero will start computing the CRC using `0xffffffff'. unsigned long gnu_debuglink_crc32 (unsigned long crc, unsigned char *buf, size_t len) { static const unsigned long crc32_table[256] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d }; unsigned char *end; crc = ~crc & 0xffffffff; for (end = buf + len; buf < end; ++buf) crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); return ~crc & 0xffffffff; } This computation does not apply to the "build ID" method.  File: gdb.info, Node: MiniDebugInfo, Next: Index Files, Prev: Separate Debug Files, Up: GDB Files 18.4 Debugging information in a special section =============================================== Some systems ship pre-built executables and libraries that have a special `.gnu_debugdata' section. This feature is called "MiniDebugInfo". This section holds an LZMA-compressed object and is used to supply extra symbols for backtraces. The intent of this section is to provide extra minimal debugging information for use in simple backtraces. It is not intended to be a replacement for full separate debugging information (*note Separate Debug Files::). The example below shows the intended use; however, GDB does not currently put restrictions on what sort of debugging information might be included in the section. GDB has support for this extension. If the section exists, then it is used provided that no other source of debugging information can be found, and that GDB was configured with LZMA support. This section can be easily created using `objcopy' and other standard utilities: # Extract the dynamic symbols from the main binary, there is no need # to also have these in the normal symbol table. nm -D BINARY --format=posix --defined-only \ | awk '{ print $1 }' | sort > dynsyms # Extract all the text (i.e. function) symbols from the debuginfo. # (Note that we actually also accept "D" symbols, for the benefit # of platforms like PowerPC64 that use function descriptors.) nm BINARY --format=posix --defined-only \ | awk '{ if ($2 == "T" || $2 == "t" || $2 == "D") print $1 }' \ | sort > funcsyms # Keep all the function symbols not already in the dynamic symbol # table. comm -13 dynsyms funcsyms > keep_symbols # Separate full debug info into debug binary. objcopy --only-keep-debug BINARY debug # Copy the full debuginfo, keeping only a minimal set of symbols and # removing some unnecessary sections. objcopy -S --remove-section .gdb_index --remove-section .comment \ --keep-symbols=keep_symbols debug mini_debuginfo # Drop the full debug info from the original binary. strip --strip-all -R .comment BINARY # Inject the compressed data into the .gnu_debugdata section of the # original binary. xz mini_debuginfo objcopy --add-section .gnu_debugdata=mini_debuginfo.xz BINARY  File: gdb.info, Node: Index Files, Next: Debug Names, Prev: MiniDebugInfo, Up: GDB Files 18.5 Index Files Speed Up GDB ============================= When GDB finds a symbol file, it scans the symbols in the file in order to construct an internal symbol table. This lets most GDB operations work quickly--at the cost of a delay early on. For large programs, this delay can be quite lengthy, so GDB provides a way to build an index, which speeds up startup. For convenience, GDB comes with a program, `gdb-add-index', which can be used to add the index to a symbol file. It takes the symbol file as its only argument: $ gdb-add-index symfile *Note gdb-add-index::. It is also possible to do the work manually. Here is what `gdb-add-index' does behind the curtains. The index is stored as a section in the symbol file. GDB can write the index to a file, then you can put it into the symbol file using `objcopy'. To create an index file, use the `save gdb-index' command: `save gdb-index [-dwarf-5] DIRECTORY' Create index files for all symbol files currently known by GDB. For each known SYMBOL-FILE, this command by default creates it produces a single file `SYMBOL-FILE.gdb-index'. If you invoke this command with the `-dwarf-5' option, it produces 2 files: `SYMBOL-FILE.debug_names' and `SYMBOL-FILE.debug_str'. The files are created in the given DIRECTORY. Once you have created an index file you can merge it into your symbol file, here named `symfile', using `objcopy': $ objcopy --add-section .gdb_index=symfile.gdb-index \ --set-section-flags .gdb_index=readonly symfile symfile Or for `-dwarf-5': $ objcopy --dump-section .debug_str=symfile.debug_str.new symfile $ cat symfile.debug_str >>symfile.debug_str.new $ objcopy --add-section .debug_names=symfile.gdb-index \ --set-section-flags .debug_names=readonly \ --update-section .debug_str=symfile.debug_str.new symfile symfile GDB will normally ignore older versions of `.gdb_index' sections that have been deprecated. Usually they are deprecated because they are missing a new feature or have performance issues. To tell GDB to use a deprecated index section anyway specify `set use-deprecated-index-sections on'. The default is `off'. This can speed up startup, but may result in some functionality being lost. *Note Index Section Format::. _Warning:_ Setting `use-deprecated-index-sections' to `on' must be done before gdb reads the file. The following will not work: $ gdb -ex "set use-deprecated-index-sections on" Instead you must do, for example, $ gdb -iex "set use-deprecated-index-sections on" Indices only work when using DWARF debugging information, not stabs. 18.5.1 Automatic symbol index cache ----------------------------------- It is possible for GDB to automatically save a copy of this index in a cache on disk and retrieve it from there when loading the same binary in the future. This feature can be turned on with `set index-cache enabled on'. The following commands can be used to tweak the behavior of the index cache. `set index-cache enabled on' `set index-cache enabled off' Enable or disable the use of the symbol index cache. `set index-cache directory DIRECTORY' `show index-cache directory' Set/show the directory where index files will be saved. The default value for this directory depends on the host platform. On most systems, the index is cached in the `gdb' subdirectory of the directory pointed to by the `XDG_CACHE_HOME' environment variable, if it is defined, else in the `.cache/gdb' subdirectory of your home directory. However, on some systems, the default may differ according to local convention. There is no limit on the disk space used by index cache. It is perfectly safe to delete the content of that directory to free up disk space. `show index-cache stats' Print the number of cache hits and misses since the launch of GDB.  File: gdb.info, Node: Debug Names, Next: Symbol Errors, Prev: Index Files, Up: GDB Files 18.6 Extensions to `.debug_names' ================================= The DWARF specification documents an optional index section called `.debug_names'. GDB can both read and create this section. However, in order to work with GDB, some extensions were necessary. GDB uses the augmentation string `GDB2'. Earlier versions used the string `GDB', but these versions of the index are no longer supported. GDB does not use the specified hash table. Therefore, because this hash table is optional, GDB also does not write it. GDB also generates and uses some extra index attributes: `DW_IDX_GNU_internal' This has the value `0x2000'. It is a flag that, when set, indicates that the associated entry has `static' linkage. `DW_IDX_GNU_main' This has the value `0x2002'. It is a flag that, when set, indicates that the associated entry is the program's `main'. `DW_IDX_GNU_language' This has the value `0x2003'. It is `DW_LANG_' constant, indicating the language of the associated entry. `DW_IDX_GNU_linkage_name' This has the value `0x2004'. It is a flag that, when set, indicates that the associated entry is a linkage name, and not a source name.  File: gdb.info, Node: Symbol Errors, Next: Data Files, Prev: Debug Names, Up: GDB Files 18.7 Errors Reading Symbol Files ================================ While reading a symbol file, GDB occasionally encounters problems, such as symbol types it does not recognize, or known bugs in compiler output. By default, GDB does not notify you of such problems, since they are relatively common and primarily of interest to people debugging compilers. If you are interested in seeing information about ill-constructed symbol tables, you can either ask GDB to print only one message about each such type of problem, no matter how many times the problem occurs; or you can ask GDB to print more messages, to see how many times the problems occur, with the `set complaints' command (*note Optional Warnings and Messages: Messages/Warnings.). The messages currently printed, and their meanings, include: `inner block not inside outer block in SYMBOL' The symbol information shows where symbol scopes begin and end (such as at the start of a function or a block of statements). This error indicates that an inner scope block is not fully contained in its outer scope blocks. GDB circumvents the problem by treating the inner block as if it had the same scope as the outer block. In the error message, SYMBOL may be shown as "`(don't know)'" if the outer block is not a function. `block at ADDRESS out of order' The symbol information for symbol scope blocks should occur in order of increasing addresses. This error indicates that it does not do so. GDB does not circumvent this problem, and has trouble locating symbols in the source file whose symbols it is reading. (You can often determine what source file is affected by specifying `set verbose on'. *Note Optional Warnings and Messages: Messages/Warnings.) `bad block start address patched' The symbol information for a symbol scope block has a start address smaller than the address of the preceding source line. This is known to occur in the SunOS 4.1.1 (and earlier) C compiler. GDB circumvents the problem by treating the symbol scope block as starting on the previous source line. `bad string table offset in symbol N' Symbol number N contains a pointer into the string table which is larger than the size of the string table. GDB circumvents the problem by considering the symbol to have the name `foo', which may cause other problems if many symbols end up with this name. `unknown symbol type `0xNN'' The symbol information contains new data types that GDB does not yet know how to read. `0xNN' is the symbol type of the uncomprehended information, in hexadecimal. GDB circumvents the error by ignoring this symbol information. This usually allows you to debug your program, though certain symbols are not accessible. If you encounter such a problem and feel like debugging it, you can debug `gdb' with itself, breakpoint on `complain', then go up to the function `read_dbx_symtab' and examine `*bufp' to see the symbol. `stub type has NULL name' GDB could not find the full definition for a struct or class. `const/volatile indicator missing (ok if using g++ v1.x), got...' The symbol information for a C++ member function is missing some information that recent versions of the compiler should have output for it. `info mismatch between compiler and debugger' GDB could not parse a type specification output by the compiler.  File: gdb.info, Node: Data Files, Prev: Symbol Errors, Up: GDB Files 18.8 GDB Data Files =================== GDB will sometimes read an auxiliary data file. These files are kept in a directory known as the "data directory". You can set the data directory's name, and view the name GDB is currently using. `set data-directory DIRECTORY' Set the directory which GDB searches for auxiliary data files to DIRECTORY. `show data-directory' Show the directory GDB searches for auxiliary data files. You can set the default data directory by using the configure-time `--with-gdb-datadir' option. If the data directory is inside GDB's configured binary prefix (set with `--prefix' or `--exec-prefix'), then the default data directory will be updated automatically if the installed GDB is moved to a new location. The data directory may also be specified with the `--data-directory' command line option. *Note Mode Options::.  File: gdb.info, Node: Targets, Next: Remote Debugging, Prev: GDB Files, Up: Top 19 Specifying a Debugging Target ******************************** A "target" is the execution environment occupied by your program. Often, GDB runs in the same host environment as your program; in that case, the debugging target is specified as a side effect when you use the `file' or `core' commands. When you need more flexibility--for example, running GDB on a physically separate host, or controlling a standalone system over a serial port or a realtime system over a TCP/IP connection--you can use the `target' command to specify one of the target types configured for GDB (*note Commands for Managing Targets: Target Commands.). It is possible to build GDB for several different "target architectures". When GDB is built like that, you can choose one of the available architectures with the `set architecture' command. `set architecture ARCH' This command sets the current target architecture to ARCH. The value of ARCH can be `"auto"', in addition to one of the supported architectures. `show architecture' Show the current target architecture. `set processor' `processor' These are alias commands for, respectively, `set architecture' and `show architecture'. * Menu: * Active Targets:: Active targets * Target Commands:: Commands for managing targets * Byte Order:: Choosing target byte order  File: gdb.info, Node: Active Targets, Next: Target Commands, Up: Targets 19.1 Active Targets =================== There are multiple classes of targets such as: processes, executable files or recording sessions. Core files belong to the process class, making core file and process mutually exclusive. Otherwise, GDB can work concurrently on multiple active targets, one in each class. This allows you to (for example) start a process and inspect its activity, while still having access to the executable file after the process finishes. Or if you start process recording (*note Reverse Execution::) and `reverse-step' there, you are presented a virtual layer of the recording target, while the process target remains stopped at the chronologically last point of the process execution. Use the `core-file' and `exec-file' commands to select a new core file or executable target (*note Commands to Specify Files: Files.). To specify as a target a process that is already running, use the `attach' command (*note Debugging an Already-running Process: Attach.).  File: gdb.info, Node: Target Commands, Next: Byte Order, Prev: Active Targets, Up: Targets 19.2 Commands for Managing Targets ================================== `target TYPE PARAMETERS' Connects the GDB host environment to a target machine or process. A target is typically a protocol for talking to debugging facilities. You use the argument TYPE to specify the type or protocol of the target machine. Further PARAMETERS are interpreted by the target protocol, but typically include things like device names or host names to connect with, process numbers, and baud rates. The `target' command does not repeat if you press again after executing the command. `help target' Displays the names of all targets available. To display targets currently selected, use either `info target' or `info files' (*note Commands to Specify Files: Files.). `help target NAME' Describe a particular target, including any parameters necessary to select it. `set gnutarget ARGS' GDB uses its own library BFD to read your files. GDB knows whether it is reading an "executable", a "core", or a ".o" file; however, you can specify the file format with the `set gnutarget' command. Unlike most `target' commands, with `gnutarget' the `target' refers to a program, not a machine. _Warning:_ To specify a file format with `set gnutarget', you must know the actual BFD name. *Note Commands to Specify Files: Files. `show gnutarget' Use the `show gnutarget' command to display what file format `gnutarget' is set to read. If you have not set `gnutarget', GDB will determine the file format for each file automatically, and `show gnutarget' displays `The current BFD target is "auto"'. Here are some common targets (available, or not, depending on the GDB configuration): `target exec PROGRAM' An executable file. `target exec PROGRAM' is the same as `exec-file PROGRAM'. `target core FILENAME' A core dump file. `target core FILENAME' is the same as `core-file FILENAME'. `target remote MEDIUM' A remote system connected to GDB via a serial line or network connection. This command tells GDB to use its own remote protocol over MEDIUM for debugging. *Note Remote Debugging::. For example, if you have a board connected to `/dev/ttya' on the machine running GDB, you could say: target remote /dev/ttya `target remote' supports the `load' command. This is only useful if you have some other way of getting the stub to the target system, and you can put it somewhere in memory where it won't get clobbered by the download. `target sim [SIMARGS] ...' Builtin CPU simulator. GDB includes simulators for most architectures. In general, target sim load run works; however, you cannot assume that a specific memory map, device drivers, or even basic I/O is available, although some simulators do provide these. For info about any processor-specific simulator details, see the appropriate section in *Note Embedded Processors: Embedded Processors. `target native' Setup for local/native process debugging. Useful to make the `run' command spawn native processes (likewise `attach', etc.) even when `set auto-connect-native-target' is `off' (*note set auto-connect-native-target::). Different targets are available on different configurations of GDB; your configuration may have more or fewer targets. Many remote targets require you to download the executable's code once you've successfully established a connection. You may wish to control various aspects of this process. `set hash' This command controls whether a hash mark `#' is displayed while downloading a file to the remote monitor. If on, a hash mark is displayed after each S-record is successfully downloaded to the monitor. `show hash' Show the current status of displaying the hash mark. `set debug monitor' Enable or disable display of communications messages between GDB and the remote monitor. `show debug monitor' Show the current status of displaying communications between GDB and the remote monitor. `load FILENAME OFFSET' Depending on what remote debugging facilities are configured into GDB, the `load' command may be available. Where it exists, it is meant to make FILENAME (an executable) available for debugging on the remote system--by downloading, or dynamic linking, for example. `load' also records the FILENAME symbol table in GDB, like the `add-symbol-file' command. If your GDB does not have a `load' command, attempting to execute it gets the error message "`You can't do that when your target is ...'" The file is loaded at whatever address is specified in the executable. For some object file formats, you can specify the load address when you link the program; for other formats, like a.out, the object file format specifies a fixed address. It is also possible to tell GDB to load the executable file at a specific offset described by the optional argument OFFSET. When OFFSET is provided, FILENAME must also be provided. Depending on the remote side capabilities, GDB may be able to load programs into flash memory. `load' does not repeat if you press again after using it. `flash-erase' Erases all known flash memory regions on the target.  File: gdb.info, Node: Byte Order, Prev: Target Commands, Up: Targets 19.3 Choosing Target Byte Order =============================== Some types of processors, such as the MIPS, PowerPC, and Renesas SH, offer the ability to run either big-endian or little-endian byte orders. Usually the executable or symbol will include a bit to designate the endian-ness, and you will not need to worry about which to use. However, you may still find it useful to adjust GDB's idea of processor endian-ness manually. `set endian big' Instruct GDB to assume the target is big-endian. `set endian little' Instruct GDB to assume the target is little-endian. `set endian auto' Instruct GDB to use the byte order associated with the executable. `show endian' Display GDB's current idea of the target byte order. If the `set endian auto' mode is in effect and no executable has been selected, then the endianness used is the last one chosen either by one of the `set endian big' and `set endian little' commands or by inferring from the last executable used. If no endianness has been previously chosen, then the default for this mode is inferred from the target GDB has been built for, and is `little' if the name of the target CPU has an `el' suffix and `big' otherwise. Note that these commands merely adjust interpretation of symbolic data on the host, and that they have absolutely no effect on the target system.  File: gdb.info, Node: Remote Debugging, Next: Configurations, Prev: Targets, Up: Top 20 Debugging Remote Programs **************************** If you are trying to debug a program running on a machine that cannot run GDB in the usual way, it is often useful to use remote debugging. For example, you might use remote debugging on an operating system kernel, or on a small system which does not have a general purpose operating system powerful enough to run a full-featured debugger. Some configurations of GDB have special serial or TCP/IP interfaces to make this work with particular debugging targets. In addition, GDB comes with a generic serial protocol (specific to GDB, but not specific to any particular target system) which you can use if you write the remote stubs--the code that runs on the remote system to communicate with GDB. Other remote targets may be available in your configuration of GDB; use `help target' to list them. * Menu: * Connecting:: Connecting to a remote target * File Transfer:: Sending files to a remote system * Server:: Using the gdbserver program * Remote Configuration:: Remote configuration * Remote Stub:: Implementing a remote stub  File: gdb.info, Node: Connecting, Next: File Transfer, Up: Remote Debugging 20.1 Connecting to a Remote Target ================================== This section describes how to connect to a remote target, including the types of connections and their differences, how to set up executable and symbol files on the host and target, and the commands used for connecting to and disconnecting from the remote target. 20.1.1 Types of Remote Connections ---------------------------------- GDB supports two types of remote connections, `target remote' mode and `target extended-remote' mode. Note that many remote targets support only `target remote' mode. There are several major differences between the two types of connections, enumerated here: Result of detach or program exit *With target remote mode:* When the debugged program exits or you detach from it, GDB disconnects from the target. When using `gdbserver', `gdbserver' will exit. *With target extended-remote mode:* When the debugged program exits or you detach from it, GDB remains connected to the target, even though no program is running. You can rerun the program, attach to a running program, or use `monitor' commands specific to the target. When using `gdbserver' in this case, it does not exit unless it was invoked using the `--once' option. If the `--once' option was not used, you can ask `gdbserver' to exit using the `monitor exit' command (*note Monitor Commands for gdbserver::). Specifying the program to debug For both connection types you use the `file' command to specify the program on the host system. If you are using `gdbserver' there are some differences in how to specify the location of the program on the target. *With target remote mode:* You must either specify the program to debug on the `gdbserver' command line or use the `--attach' option (*note Attaching to a Running Program: Attaching to a program.). *With target extended-remote mode:* You may specify the program to debug on the `gdbserver' command line, or you can load the program or attach to it using GDB commands after connecting to `gdbserver'. You can start `gdbserver' without supplying an initial command to run or process ID to attach. To do this, use the `--multi' command line option. Then you can connect using `target extended-remote' and start the program you want to debug (see below for details on using the `run' command in this scenario). Note that the conditions under which `gdbserver' terminates depend on how GDB connects to it (`target remote' or `target extended-remote'). The `--multi' option to `gdbserver' has no influence on that. The `run' command *With target remote mode:* The `run' command is not supported. Once a connection has been established, you can use all the usual GDB commands to examine and change data. The remote program is already running, so you can use commands like `step' and `continue'. *With target extended-remote mode:* The `run' command is supported. The `run' command uses the value set by `set remote exec-file' (*note set remote exec-file::) to select the program to run. Command line arguments are supported, except for wildcard expansion and I/O redirection (*note Arguments::). If you specify the program to debug on the command line, then the `run' command is not required to start execution, and you can resume using commands like `step' and `continue' as with `target remote' mode. Attaching *With target remote mode:* The GDB command `attach' is not supported. To attach to a running program using `gdbserver', you must use the `--attach' option (*note Running gdbserver::). *With target extended-remote mode:* To attach to a running program, you may use the `attach' command after the connection has been established. If you are using `gdbserver', you may also invoke `gdbserver' using the `--attach' option (*note Running gdbserver::). Some remote targets allow GDB to determine the executable file running in the process the debugger is attaching to. In such a case, GDB uses the value of `exec-file-mismatch' to handle a possible mismatch between the executable file name running in the process and the name of the current exec-file loaded by GDB (*note set exec-file-mismatch::). 20.1.2 Host and Target Files ---------------------------- GDB, running on the host, needs access to symbol and debugging information for your program running on the target. This requires access to an unstripped copy of your program, and possibly any associated symbol files. Note that this section applies equally to both `target remote' mode and `target extended-remote' mode. Some remote targets (*note qXfer executable filename read::, and *note Host I/O Packets::) allow GDB to access program files over the same connection used to communicate with GDB. With such a target, if the remote program is unstripped, the only command you need is `target remote' (or `target extended-remote'). If the remote program is stripped, or the target does not support remote program file access, start up GDB using the name of the local unstripped copy of your program as the first argument, or use the `file' command. Use `set sysroot' to specify the location (on the host) of target libraries (unless your GDB was compiled with the correct sysroot using `--with-sysroot'). Alternatively, you may use `set solib-search-path' to specify how GDB locates target libraries. The symbol file and target libraries must exactly match the executable and libraries on the target, with one exception: the files on the host system should not be stripped, even if the files on the target system are. Mismatched or missing files will lead to confusing results during debugging. On GNU/Linux targets, mismatched or missing files may also prevent `gdbserver' from debugging multi-threaded programs. 20.1.3 Remote Connection Commands --------------------------------- GDB can communicate with the target over a serial line, a local Unix domain socket, or over an IP network using TCP or UDP. In each case, GDB uses the same protocol for debugging your program; only the medium carrying the debugging packets varies. The `target remote' and `target extended-remote' commands establish a connection to the target. Both commands accept the same arguments, which indicate the medium to use: `target remote SERIAL-DEVICE' `target extended-remote SERIAL-DEVICE' Use SERIAL-DEVICE to communicate with the target. For example, to use a serial line connected to the device named `/dev/ttyb': target remote /dev/ttyb If you're using a serial line, you may want to give GDB the `--baud' option, or use the `set serial baud' command (*note set serial baud: Remote Configuration.) before the `target' command. `target remote LOCAL-SOCKET' `target extended-remote LOCAL-SOCKET' Use LOCAL-SOCKET to communicate with the target. For example, to use a local Unix domain socket bound to the file system entry `/tmp/gdb-socket0': target remote /tmp/gdb-socket0 Note that this command has the same form as the command to connect to a serial line. GDB will automatically determine which kind of file you have specified and will make the appropriate kind of connection. This feature is not available if the host system does not support Unix domain sockets. `target remote `HOST:PORT'' `target remote `[HOST]:PORT'' `target remote `tcp:HOST:PORT'' `target remote `tcp:[HOST]:PORT'' `target remote `tcp4:HOST:PORT'' `target remote `tcp6:HOST:PORT'' `target remote `tcp6:[HOST]:PORT'' `target extended-remote `HOST:PORT'' `target extended-remote `[HOST]:PORT'' `target extended-remote `tcp:HOST:PORT'' `target extended-remote `tcp:[HOST]:PORT'' `target extended-remote `tcp4:HOST:PORT'' `target extended-remote `tcp6:HOST:PORT'' `target extended-remote `tcp6:[HOST]:PORT'' Debug using a TCP connection to PORT on HOST. The HOST may be either a host name, a numeric IPv4 address, or a numeric IPv6 address (with or without the square brackets to separate the address from the port); PORT must be a decimal number. The HOST could be the target machine itself, if it is directly connected to the net, or it might be a terminal server which in turn has a serial line to the target. For example, to connect to port 2828 on a terminal server named `manyfarms': target remote manyfarms:2828 To connect to port 2828 on a terminal server whose address is `2001:0db8:85a3:0000:0000:8a2e:0370:7334', you can either use the square bracket syntax: target remote [2001:0db8:85a3:0000:0000:8a2e:0370:7334]:2828 or explicitly specify the IPv6 protocol: target remote tcp6:2001:0db8:85a3:0000:0000:8a2e:0370:7334:2828 This last example may be confusing to the reader, because there is no visible separation between the hostname and the port number. Therefore, we recommend the user to provide IPv6 addresses using square brackets for clarity. However, it is important to mention that for GDB there is no ambiguity: the number after the last colon is considered to be the port number. If your remote target is actually running on the same machine as your debugger session (e.g. a simulator for your target running on the same host), you can omit the hostname. For example, to connect to port 1234 on your local machine: target remote :1234 Note that the colon is still required here. `target remote `udp:HOST:PORT'' `target remote `udp:[HOST]:PORT'' `target remote `udp4:HOST:PORT'' `target remote `udp6:[HOST]:PORT'' `target extended-remote `udp:HOST:PORT'' `target extended-remote `udp:HOST:PORT'' `target extended-remote `udp:[HOST]:PORT'' `target extended-remote `udp4:HOST:PORT'' `target extended-remote `udp6:HOST:PORT'' `target extended-remote `udp6:[HOST]:PORT'' Debug using UDP packets to PORT on HOST. For example, to connect to UDP port 2828 on a terminal server named `manyfarms': target remote udp:manyfarms:2828 When using a UDP connection for remote debugging, you should keep in mind that the `U' stands for "Unreliable". UDP can silently drop packets on busy or unreliable networks, which will cause havoc with your debugging session. `target remote | COMMAND' `target extended-remote | COMMAND' Run COMMAND in the background and communicate with it using a pipe. The COMMAND is a shell command, to be parsed and expanded by the system's command shell, `/bin/sh'; it should expect remote protocol packets on its standard input, and send replies on its standard output. You could use this to run a stand-alone simulator that speaks the remote debugging protocol, to make net connections using programs like `ssh', or for other similar tricks. If COMMAND closes its standard output (perhaps by exiting), GDB will try to send it a `SIGTERM' signal. (If the program has already exited, this will have no effect.) Whenever GDB is waiting for the remote program, if you type the interrupt character (often `Ctrl-c'), GDB attempts to stop the program. This may or may not succeed, depending in part on the hardware and the serial drivers the remote system uses. If you type the interrupt character once again, GDB displays this prompt: Interrupted while waiting for the program. Give up (and stop debugging it)? (y or n) In `target remote' mode, if you type `y', GDB abandons the remote debugging session. (If you decide you want to try again later, you can use `target remote' again to connect once more.) If you type `n', GDB goes back to waiting. In `target extended-remote' mode, typing `n' will leave GDB connected to the target. `detach' When you have finished debugging the remote program, you can use the `detach' command to release it from GDB control. Detaching from the target normally resumes its execution, but the results will depend on your particular remote stub. After the `detach' command in `target remote' mode, GDB is free to connect to another target. In `target extended-remote' mode, GDB is still connected to the target. `disconnect' The `disconnect' command closes the connection to the target, and the target is generally not resumed. It will wait for GDB (this instance or another one) to connect and continue debugging. After the `disconnect' command, GDB is again free to connect to another target. `monitor CMD' This command allows you to send arbitrary commands directly to the remote monitor. Since GDB doesn't care about the commands it sends like this, this command is the way to extend GDB--you can add new commands that only the external monitor will understand and implement.  File: gdb.info, Node: File Transfer, Next: Server, Prev: Connecting, Up: Remote Debugging 20.2 Sending files to a remote system ===================================== Some remote targets offer the ability to transfer files over the same connection used to communicate with GDB. This is convenient for targets accessible through other means, e.g. GNU/Linux systems running `gdbserver' over a network interface. For other targets, e.g. embedded devices with only a single serial port, this may be the only way to upload or download files. Not all remote targets support these commands. `remote put HOSTFILE TARGETFILE' Copy file HOSTFILE from the host system (the machine running GDB) to TARGETFILE on the target system. `remote get TARGETFILE HOSTFILE' Copy file TARGETFILE from the target system to HOSTFILE on the host system. `remote delete TARGETFILE' Delete TARGETFILE from the target system.  File: gdb.info, Node: Server, Next: Remote Configuration, Prev: File Transfer, Up: Remote Debugging 20.3 Using the `gdbserver' Program ================================== `gdbserver' is a control program for Unix-like systems, which allows you to connect your program with a remote GDB via `target remote' or `target extended-remote'--but without linking in the usual debugging stub. `gdbserver' is not a complete replacement for the debugging stubs, because it requires essentially the same operating-system facilities that GDB itself does. In fact, a system that can run `gdbserver' to connect to a remote GDB could also run GDB locally! `gdbserver' is sometimes useful nevertheless, because it is a much smaller program than GDB itself. It is also easier to port than all of GDB, so you may be able to get started more quickly on a new system by using `gdbserver'. Finally, if you develop code for real-time systems, you may find that the tradeoffs involved in real-time operation make it more convenient to do as much development work as possible on another system, for example by cross-compiling. You can use `gdbserver' to make a similar choice for debugging. GDB and `gdbserver' communicate via either a serial line or a TCP connection, using the standard GDB remote serial protocol. _Warning:_ `gdbserver' does not have any built-in security. Do not run `gdbserver' connected to any public network; a GDB connection to `gdbserver' provides access to the target system with the same privileges as the user running `gdbserver'. 20.3.1 Running `gdbserver' -------------------------- Run `gdbserver' on the target system. You need a copy of the program you want to debug, including any libraries it requires. `gdbserver' does not need your program's symbol table, so you can strip the program if necessary to save space. GDB on the host system does all the symbol handling. To use the server, you must tell it how to communicate with GDB; the name of your program; and the arguments for your program. The usual syntax is: target> gdbserver COMM PROGRAM [ ARGS ... ] COMM is either a device name (to use a serial line), or a TCP hostname and portnumber, or `-' or `stdio' to use stdin/stdout of `gdbserver'. For example, to debug Emacs with the argument `foo.txt' and communicate with GDB over the serial port `/dev/com1': target> gdbserver /dev/com1 emacs foo.txt `gdbserver' waits passively for the host GDB to communicate with it. To use a TCP connection instead of a serial line: target> gdbserver host:2345 emacs foo.txt The only difference from the previous example is the first argument, specifying that you are communicating with the host GDB via TCP. The `host:2345' argument means that `gdbserver' is to expect a TCP connection from machine `host' to local TCP port 2345. (Currently, the `host' part is ignored.) You can choose any number you want for the port number as long as it does not conflict with any TCP ports already in use on the target system (for example, `23' is reserved for `telnet').(1) You must use the same port number with the host GDB `target remote' command. The `stdio' connection is useful when starting `gdbserver' with ssh: (gdb) target remote | ssh -T hostname gdbserver - hello The `-T' option to ssh is provided because we don't need a remote pty, and we don't want escape-character handling. Ssh does this by default when a command is provided, the flag is provided to make it explicit. You could elide it if you want to. Programs started with stdio-connected gdbserver have `/dev/null' for `stdin', and `stdout',`stderr' are sent back to gdb for display through a pipe connected to gdbserver. Both `stdout' and `stderr' use the same pipe. 20.3.1.1 Attaching to a Running Program ....................................... On some targets, `gdbserver' can also attach to running programs. This is accomplished via the `--attach' argument. The syntax is: target> gdbserver --attach COMM PID PID is the process ID of a currently running process. It isn't necessary to point `gdbserver' at a binary for the running process. In `target extended-remote' mode, you can also attach using the GDB attach command (*note Attaching in Types of Remote Connections::). You can debug processes by name instead of process ID if your target has the `pidof' utility: target> gdbserver --attach COMM `pidof PROGRAM` In case more than one copy of PROGRAM is running, or PROGRAM has multiple threads, most versions of `pidof' support the `-s' option to only return the first process ID. 20.3.1.2 TCP port allocation lifecycle of `gdbserver' ..................................................... This section applies only when `gdbserver' is run to listen on a TCP port. `gdbserver' normally terminates after all of its debugged processes have terminated in `target remote' mode. On the other hand, for `target extended-remote', `gdbserver' stays running even with no processes left. GDB normally terminates the spawned debugged process on its exit, which normally also terminates `gdbserver' in the `target remote' mode. Therefore, when the connection drops unexpectedly, and GDB cannot ask `gdbserver' to kill its debugged processes, `gdbserver' stays running even in the `target remote' mode. When `gdbserver' stays running, GDB can connect to it again later. Such reconnecting is useful for features like *Note disconnected tracing::. For completeness, at most one GDB can be connected at a time. By default, `gdbserver' keeps the listening TCP port open, so that subsequent connections are possible. However, if you start `gdbserver' with the `--once' option, it will stop listening for any further connection attempts after connecting to the first GDB session. This means no further connections to `gdbserver' will be possible after the first one. It also means `gdbserver' will terminate after the first connection with remote GDB has closed, even for unexpectedly closed connections and even in the `target extended-remote' mode. The `--once' option allows reusing the same port number for connecting to multiple instances of `gdbserver' running on the same host, since each instance closes its port after the first connection. 20.3.1.3 Other Command-Line Arguments for `gdbserver' ..................................................... You can use the `--multi' option to start `gdbserver' without specifying a program to debug or a process to attach to. Then you can attach in `target extended-remote' mode and run or attach to a program. For more information, *note --multi Option in Types of Remote Connnections::. The `--debug[=option1,option2,...]' option tells `gdbserver' to display extra diagnostic information about the debugging process. The options (OPTION1, OPTION2, etc) control for which areas of `gdbserver' additional information will be displayed, possible values are: `all' This enables all available diagnostic output. `threads' This enables diagnostic output related to threading. Currently other general diagnostic output is included in this category, but this could change in future releases of `gdbserver'. `event-loop' This enables event-loop specific diagnostic output. `remote' This enables diagnostic output related to the transfer of remote protocol packets too and from the debugger. If no options are passed to `--debug' then this is treated as equivalent to `--debug=threads'. This could change in future releases of `gdbserver'. The options passed to `--debug' are processed left to right, and individual options can be prefixed with the `-' (minus) character to disable diagnostic output from this area, so it is possible to use: target> gdbserver --debug=all,-event-loop In order to enable all diagnostic output except that for the event-loop. The `--debug-file=FILENAME' option tells `gdbserver' to write any debug output to the given FILENAME. These options are intended for `gdbserver' development and for bug reports to the developers. The `--debug-format=option1[,option2,...]' option tells `gdbserver' to include additional information in each output. Possible options are: `none' Turn off all extra information in debugging output. `all' Turn on all extra information in debugging output. `timestamps' Include a timestamp in each line of debugging output. Options are processed in order. Thus, for example, if `none' appears last then no additional information is added to debugging output. The `--wrapper' option specifies a wrapper to launch programs for debugging. The option should be followed by the name of the wrapper, then any command-line arguments to pass to the wrapper, then `--' indicating the end of the wrapper arguments. `gdbserver' runs the specified wrapper program with a combined command line including the wrapper arguments, then the name of the program to debug, then any arguments to the program. The wrapper runs until it executes your program, and then GDB gains control. You can use any program that eventually calls `execve' with its arguments as a wrapper. Several standard Unix utilities do this, e.g. `env' and `nohup'. Any Unix shell script ending with `exec "$@@"' will also work. For example, you can use `env' to pass an environment variable to the debugged program, without setting the variable in `gdbserver''s environment: $ gdbserver --wrapper env LD_PRELOAD=libtest.so -- :2222 ./testprog The `--selftest' option runs the self tests in `gdbserver': $ gdbserver --selftest Ran 2 unit tests, 0 failed These tests are disabled in release. 20.3.2 Connecting to `gdbserver' -------------------------------- The basic procedure for connecting to the remote target is: * Run GDB on the host system. * Make sure you have the necessary symbol files (*note Host and target files::). Load symbols for your application using the `file' command before you connect. Use `set sysroot' to locate target libraries (unless your GDB was compiled with the correct sysroot using `--with-sysroot'). * Connect to your target (*note Connecting to a Remote Target: Connecting.). For TCP connections, you must start up `gdbserver' prior to using the `target' command. Otherwise you may get an error whose text depends on the host system, but which usually looks something like `Connection refused'. Don't use the `load' command in GDB when using `target remote' mode, since the program is already on the target. 20.3.3 Monitor Commands for `gdbserver' --------------------------------------- During a GDB session using `gdbserver', you can use the `monitor' command to send special requests to `gdbserver'. Here are the available commands. `monitor help' List the available monitor commands. `monitor set debug off' Disable all internal logging from gdbserver. `monitor set debug on' Enable some general logging from within gdbserver. Currently this is equivalent to `monitor set debug threads on', but this might change in future releases of gdbserver. `monitor set debug threads off' `monitor set debug threads on' Disable or enable specific logging messages associated with thread handling in gdbserver. Currently this category also includes additional output not specifically related to thread handling, this could change in future releases of gdbserver. `monitor set debug remote off' `monitor set debug remote on' Disable or enable specific logging messages associated with the remote protocol (*note Remote Protocol::). `monitor set debug event-loop off' `monitor set debug event-loop on' Disable or enable specific logging messages associated with gdbserver's event-loop. `monitor set debug-file filename' `monitor set debug-file' Send any debug output to the given file, or to stderr. `monitor set debug-format option1[,option2,...]' Specify additional text to add to debugging messages. Possible options are: `none' Turn off all extra information in debugging output. `all' Turn on all extra information in debugging output. `timestamps' Include a timestamp in each line of debugging output. Options are processed in order. Thus, for example, if `none' appears last then no additional information is added to debugging output. `monitor set libthread-db-search-path [PATH]' When this command is issued, PATH is a colon-separated list of directories to search for `libthread_db' (*note set libthread-db-search-path: Threads.). If you omit PATH, `libthread-db-search-path' will be reset to its default value. The special entry `$pdir' for `libthread-db-search-path' is not supported in `gdbserver'. `monitor exit' Tell gdbserver to exit immediately. This command should be followed by `disconnect' to close the debugging session. `gdbserver' will detach from any attached processes and kill any processes it created. Use `monitor exit' to terminate `gdbserver' at the end of a multi-process mode debug session. 20.3.4 Tracepoints support in `gdbserver' ----------------------------------------- On some targets, `gdbserver' supports tracepoints, fast tracepoints and static tracepoints. For fast or static tracepoints to work, a special library called the "in-process agent" (IPA), must be loaded in the inferior process. This library is built and distributed as an integral part of `gdbserver'. In addition, support for static tracepoints requires building the in-process agent library with static tracepoints support. At present, the UST (LTTng Userspace Tracer, `http://lttng.org/ust') tracing engine is supported. This support is automatically available if UST development headers are found in the standard include path when `gdbserver' is built, or if `gdbserver' was explicitly configured using `--with-ust' to point at such headers. You can explicitly disable the support using `--with-ust=no'. There are several ways to load the in-process agent in your program: `Specifying it as dependency at link time' You can link your program dynamically with the in-process agent library. On most systems, this is accomplished by adding `-linproctrace' to the link command. `Using the system's preloading mechanisms' You can force loading the in-process agent at startup time by using your system's support for preloading shared libraries. Many Unixes support the concept of preloading user defined libraries. In most cases, you do that by specifying `LD_PRELOAD=libinproctrace.so' in the environment. See also the description of `gdbserver''s `--wrapper' command line option. `Using GDB to force loading the agent at run time' On some systems, you can force the inferior to load a shared library, by calling a dynamic loader function in the inferior that takes care of dynamically looking up and loading a shared library. On most Unix systems, the function is `dlopen'. You'll use the `call' command for that. For example: (gdb) call dlopen ("libinproctrace.so", ...) Note that on most Unix systems, for the `dlopen' function to be available, the program needs to be linked with `-ldl'. On systems that have a userspace dynamic loader, like most Unix systems, when you connect to `gdbserver' using `target remote', you'll find that the program is stopped at the dynamic loader's entry point, and no shared library has been loaded in the program's address space yet, including the in-process agent. In that case, before being able to use any of the fast or static tracepoints features, you need to let the loader run and load the shared libraries. The simplest way to do that is to run the program to the main procedure. E.g., if debugging a C or C++ program, start `gdbserver' like so: $ gdbserver :9999 myprogram Start GDB and connect to `gdbserver' like so, and run to main: $ gdb myprogram (gdb) target remote myhost:9999 0x00007f215893ba60 in ?? () from /lib64/ld-linux-x86-64.so.2 (gdb) b main (gdb) continue The in-process tracing agent library should now be loaded into the process; you can confirm it with the `info sharedlibrary' command, which will list `libinproctrace.so' as loaded in the process. You are now ready to install fast tracepoints, list static tracepoint markers, probe static tracepoints markers, and start tracing. ---------- Footnotes ---------- (1) If you choose a port number that conflicts with another service, `gdbserver' prints an error message and exits.  File: gdb.info, Node: Remote Configuration, Next: Remote Stub, Prev: Server, Up: Remote Debugging 20.4 Remote Configuration ========================= This section documents the configuration options available when debugging remote programs. For the options related to the File I/O extensions of the remote protocol, see *Note system-call-allowed: system. `set remoteaddresssize BITS' Set the maximum size of address in a memory packet to the specified number of bits. GDB will mask off the address bits above that number, when it passes addresses to the remote target. The default value is the number of bits in the target's address. `show remoteaddresssize' Show the current value of remote address size in bits. `set serial baud N' Set the baud rate for the remote serial I/O to N baud. The value is used to set the speed of the serial port used for debugging remote targets. `show serial baud' Show the current speed of the remote connection. `set serial parity PARITY' Set the parity for the remote serial I/O. Supported values of PARITY are: `even', `none', and `odd'. The default is `none'. `show serial parity' Show the current parity of the serial port. `set remotebreak' If set to on, GDB sends a `BREAK' signal to the remote when you type `Ctrl-c' to interrupt the program running on the remote. If set to off, GDB sends the `Ctrl-C' character instead. The default is off, since most remote systems expect to see `Ctrl-C' as the interrupt signal. `show remotebreak' Show whether GDB sends `BREAK' or `Ctrl-C' to interrupt the remote program. `set remoteflow on' `set remoteflow off' Enable or disable hardware flow control (`RTS'/`CTS') on the serial port used to communicate to the remote target. `show remoteflow' Show the current setting of hardware flow control. `set remotelogbase BASE' Set the base (a.k.a. radix) of logging serial protocol communications to BASE. Supported values of BASE are: `ascii', `octal', and `hex'. The default is `ascii'. `show remotelogbase' Show the current setting of the radix for logging remote serial protocol. `set remotelogfile FILE' Record remote serial communications on the named FILE. The default is not to record at all. `show remotelogfile' Show the current setting of the file name on which to record the serial communications. `set remotetimeout NUM' Set the timeout limit to wait for the remote target to respond to NUM seconds. The default is 2 seconds. `show remotetimeout' Show the current number of seconds to wait for the remote target responses. `set remote hardware-watchpoint-limit LIMIT' `set remote hardware-breakpoint-limit LIMIT' Restrict GDB to using LIMIT remote hardware watchpoints or breakpoints. The LIMIT can be set to 0 to disable hardware watchpoints or breakpoints, and `unlimited' for unlimited watchpoints or breakpoints. `show remote hardware-watchpoint-limit' `show remote hardware-breakpoint-limit' Show the current limit for the number of hardware watchpoints or breakpoints that GDB can use. `set remote hardware-watchpoint-length-limit LIMIT' Restrict GDB to using LIMIT bytes for the maximum length of a remote hardware watchpoint. A LIMIT of 0 disables hardware watchpoints and `unlimited' allows watchpoints of any length. `show remote hardware-watchpoint-length-limit' Show the current limit (in bytes) of the maximum length of a remote hardware watchpoint. `set remote exec-file FILENAME' `show remote exec-file' Select the file used for `run' with `target extended-remote'. This should be set to a filename valid on the target system. If it is not set, the target will use a default filename (e.g. the last program run). `set remote interrupt-sequence' Allow the user to select one of `Ctrl-C', a `BREAK' or `BREAK-g' as the sequence to the remote target in order to interrupt the execution. `Ctrl-C' is a default. Some system prefers `BREAK' which is high level of serial line for some certain time. Linux kernel prefers `BREAK-g', a.k.a Magic SysRq g. It is `BREAK' signal followed by character `g'. `show remote interrupt-sequence' Show which of `Ctrl-C', `BREAK' or `BREAK-g' is sent by GDB to interrupt the remote program. `BREAK-g' is BREAK signal followed by `g' and also known as Magic SysRq g. `set remote interrupt-on-connect' Specify whether interrupt-sequence is sent to remote target when GDB connects to it. This is mostly needed when you debug Linux kernel. Linux kernel expects `BREAK' followed by `g' which is known as Magic SysRq g in order to connect GDB. `show remote interrupt-on-connect' Show whether interrupt-sequence is sent to remote target when GDB connects to it. `set tcp auto-retry on' Enable auto-retry for remote TCP connections. This is useful if the remote debugging agent is launched in parallel with GDB; there is a race condition because the agent may not become ready to accept the connection before GDB attempts to connect. When auto-retry is enabled, if the initial attempt to connect fails, GDB reattempts to establish the connection using the timeout specified by `set tcp connect-timeout'. `set tcp auto-retry off' Do not auto-retry failed TCP connections. `show tcp auto-retry' Show the current auto-retry setting. `set tcp connect-timeout SECONDS' `set tcp connect-timeout unlimited' Set the timeout for establishing a TCP connection to the remote target to SECONDS. The timeout affects both polling to retry failed connections (enabled by `set tcp auto-retry on') and waiting for connections that are merely slow to complete, and represents an approximate cumulative value. If SECONDS is `unlimited', there is no timeout and GDB will keep attempting to establish a connection forever, unless interrupted with `Ctrl-c'. The default is 15 seconds. `show tcp connect-timeout' Show the current connection timeout setting. The GDB remote protocol autodetects the packets supported by your debugging stub. If you need to override the autodetection, you can use these commands to enable or disable individual packets. Each packet can be set to `on' (the remote target supports this packet), `off' (the remote target does not support this packet), or `auto' (detect remote target support for this packet). They all default to `auto'. For more information about each packet, see *Note Remote Protocol::. During normal use, you should not have to use any of these commands. If you do, that may be a bug in your remote debugging stub, or a bug in GDB. You may want to report the problem to the GDB developers. For each packet NAME, the command to enable or disable the packet is `set remote NAME-packet'. If you configure a packet, the configuration will apply for all future remote targets if no target is selected. In case there is a target selected, only the configuration of the current target is changed. All other existing remote targets' features are not affected. The command to print the current configuration of a packet is `show remote NAME-packet'. It displays the current remote target's configuration. If no remote target is selected, the default configuration for future connections is shown. The available settings are: Command Name Remote Packet Related Features `fetch-register' `p' `info registers' `set-register' `P' `set' `binary-download' `X' `load', `set' `read-aux-vector' `qXfer:auxv:read' `info auxv' `symbol-lookup' `qSymbol' Detecting multiple threads `attach' `vAttach' `attach' `verbose-resume' `vCont' Stepping or resuming multiple threads `run' `vRun' `run' `software-breakpoint'`Z0' `break' `hardware-breakpoint'`Z1' `hbreak' `write-watchpoint' `Z2' `watch' `read-watchpoint' `Z3' `rwatch' `access-watchpoint' `Z4' `awatch' `pid-to-exec-file' `qXfer:exec-file:read' `attach', `run' `target-features' `qXfer:features:read' `set architecture' `library-info' `qXfer:libraries:read' `info sharedlibrary' `memory-map' `qXfer:memory-map:read' `info mem' `read-sdata-object' `qXfer:sdata:read' `print $_sdata' `read-siginfo-object'`qXfer:siginfo:read' `print $_siginfo' `write-siginfo-object'`qXfer:siginfo:write' `set $_siginfo' `threads' `qXfer:threads:read' `info threads' `get-thread-local- `qGetTLSAddr' Displaying storage-address' `__thread' variables `get-thread-information-block-address'`qGetTIBAddr' Display MS-Windows Thread Information Block. `search-memory' `qSearch:memory' `find' `supported-packets' `qSupported' Remote communications parameters `catch-syscalls' `QCatchSyscalls' `catch syscall' `pass-signals' `QPassSignals' `handle SIGNAL' `program-signals' `QProgramSignals' `handle SIGNAL' `hostio-close-packet'`vFile:close' `remote get', `remote put' `hostio-open-packet' `vFile:open' `remote get', `remote put' `hostio-pread-packet'`vFile:pread' `remote get', `remote put' `hostio-pwrite-packet'`vFile:pwrite' `remote get', `remote put' `hostio-unlink-packet'`vFile:unlink' `remote delete' `hostio-readlink-packet'`vFile:readlink' Host I/O `hostio-fstat-packet'`vFile:fstat' Host I/O `hostio-setfs-packet'`vFile:setfs' Host I/O `noack-packet' `QStartNoAckMode' Packet acknowledgment `osdata' `qXfer:osdata:read' `info os' `query-attached' `qAttached' Querying remote process attach state. `trace-buffer-size' `QTBuffer:size' `set trace-buffer-size' `trace-status' `qTStatus' `tstatus' `traceframe-info' `qXfer:traceframe-info:read'Traceframe info `install-in-trace' `InstallInTrace' Install tracepoint in tracing `disable-randomization'`QDisableRandomization' `set disable-randomization' `startup-with-shell' `QStartupWithShell' `set startup-with-shell' `environment-hex-encoded'`QEnvironmentHexEncoded'`set environment' `environment-unset' `QEnvironmentUnset' `unset environment' `environment-reset' `QEnvironmentReset' `Reset the inferior environment (i.e., unset user-set variables)' `set-working-dir' `QSetWorkingDir' `set cwd' `conditional-breakpoints-packet'`Z0 and Z1' `Support for target-side breakpoint condition evaluation' `multiprocess-extensions'`multiprocess Debug multiple extensions' processes and remote process PID awareness `swbreak-feature' `swbreak stop reason' `break' `hwbreak-feature' `hwbreak stop reason' `hbreak' `fork-event-feature' `fork stop reason' `fork' `vfork-event-feature'`vfork stop reason' `vfork' `exec-event-feature' `exec stop reason' `exec' `thread-events' `QThreadEvents' Tracking thread lifetime. `thread-options' `QThreadOptions' Set thread event reporting options. `no-resumed-stop-reply'`no resumed thread Tracking thread left stop reply' lifetime. The number of bytes per memory-read or memory-write packet for a remote target can be configured using the commands `set remote memory-read-packet-size' and `set remote memory-write-packet-size'. If set to `0' (zero) the default packet size will be used. The actual limit is further reduced depending on the target. Specify `fixed' to disable the target-dependent restriction and `limit' to enable it. Similar to the enabling and disabling of remote packets, the command applies to the currently selected target (if available). If no remote target is selected, it applies to all future remote connections. The configuration of the selected target can be displayed using the commands `show remote memory-read-packet-size' and `show remote memory-write-packet-size'. If no remote target is selected, the default configuration for future connections is shown.  File: gdb.info, Node: Remote Stub, Prev: Remote Configuration, Up: Remote Debugging 20.5 Implementing a Remote Stub =============================== The stub files provided with GDB implement the target side of the communication protocol, and the GDB side is implemented in the GDB source file `remote.c'. Normally, you can simply allow these subroutines to communicate, and ignore the details. (If you're implementing your own stub file, you can still ignore the details: start with one of the existing stub files. `sparc-stub.c' is the best organized, and therefore the easiest to read.) To debug a program running on another machine (the debugging "target" machine), you must first arrange for all the usual prerequisites for the program to run by itself. For example, for a C program, you need: 1. A startup routine to set up the C runtime environment; these usually have a name like `crt0'. The startup routine may be supplied by your hardware supplier, or you may have to write your own. 2. A C subroutine library to support your program's subroutine calls, notably managing input and output. 3. A way of getting your program to the other machine--for example, a download program. These are often supplied by the hardware manufacturer, but you may have to write your own from hardware documentation. The next step is to arrange for your program to use a serial port to communicate with the machine where GDB is running (the "host" machine). In general terms, the scheme looks like this: _On the host,_ GDB already understands how to use this protocol; when everything else is set up, you can simply use the `target remote' command (*note Specifying a Debugging Target: Targets.). _On the target,_ you must link with your program a few special-purpose subroutines that implement the GDB remote serial protocol. The file containing these subroutines is called a "debugging stub". On certain remote targets, you can use an auxiliary program `gdbserver' instead of linking a stub into your program. *Note Using the `gdbserver' Program: Server, for details. The debugging stub is specific to the architecture of the remote machine; for example, use `sparc-stub.c' to debug programs on SPARC boards. These working remote stubs are distributed with GDB: `i386-stub.c' For Intel 386 and compatible architectures. `m68k-stub.c' For Motorola 680x0 architectures. `sh-stub.c' For Renesas SH architectures. `sparc-stub.c' For SPARC architectures. `sparcl-stub.c' For Fujitsu SPARCLITE architectures. The `README' file in the GDB distribution may list other recently added stubs. * Menu: * Stub Contents:: What the stub can do for you * Bootstrapping:: What you must do for the stub * Debug Session:: Putting it all together  File: gdb.info, Node: Stub Contents, Next: Bootstrapping, Up: Remote Stub 20.5.1 What the Stub Can Do for You ----------------------------------- The debugging stub for your architecture supplies these three subroutines: `set_debug_traps' This routine arranges for `handle_exception' to run when your program stops. You must call this subroutine explicitly in your program's startup code. `handle_exception' This is the central workhorse, but your program never calls it explicitly--the setup code arranges for `handle_exception' to run when a trap is triggered. `handle_exception' takes control when your program stops during execution (for example, on a breakpoint), and mediates communications with GDB on the host machine. This is where the communications protocol is implemented; `handle_exception' acts as the GDB representative on the target machine. It begins by sending summary information on the state of your program, then continues to execute, retrieving and transmitting any information GDB needs, until you execute a GDB command that makes your program resume; at that point, `handle_exception' returns control to your own code on the target machine. `breakpoint' Use this auxiliary subroutine to make your program contain a breakpoint. Depending on the particular situation, this may be the only way for GDB to get control. For instance, if your target machine has some sort of interrupt button, you won't need to call this; pressing the interrupt button transfers control to `handle_exception'--in effect, to GDB. On some machines, simply receiving characters on the serial port may also trigger a trap; again, in that situation, you don't need to call `breakpoint' from your own program--simply running `target remote' from the host GDB session gets control. Call `breakpoint' if none of these is true, or if you simply want to make certain your program stops at a predetermined point for the start of your debugging session.  File: gdb.info, Node: Bootstrapping, Next: Debug Session, Prev: Stub Contents, Up: Remote Stub 20.5.2 What You Must Do for the Stub ------------------------------------ The debugging stubs that come with GDB are set up for a particular chip architecture, but they have no information about the rest of your debugging target machine. First of all you need to tell the stub how to communicate with the serial port. `int getDebugChar()' Write this subroutine to read a single character from the serial port. It may be identical to `getchar' for your target system; a different name is used to allow you to distinguish the two if you wish. `void putDebugChar(int)' Write this subroutine to write a single character to the serial port. It may be identical to `putchar' for your target system; a different name is used to allow you to distinguish the two if you wish. If you want GDB to be able to stop your program while it is running, you need to use an interrupt-driven serial driver, and arrange for it to stop when it receives a `^C' (`\003', the control-C character). That is the character which GDB uses to tell the remote system to stop. Getting the debugging target to return the proper status to GDB probably requires changes to the standard stub; one quick and dirty way is to just execute a breakpoint instruction (the "dirty" part is that GDB reports a `SIGTRAP' instead of a `SIGINT'). Other routines you need to supply are: `void exceptionHandler (int EXCEPTION_NUMBER, void *EXCEPTION_ADDRESS)' Write this function to install EXCEPTION_ADDRESS in the exception handling tables. You need to do this because the stub does not have any way of knowing what the exception handling tables on your target system are like (for example, the processor's table might be in ROM, containing entries which point to a table in RAM). The EXCEPTION_NUMBER specifies the exception which should be changed; its meaning is architecture-dependent (for example, different numbers might represent divide by zero, misaligned access, etc). When this exception occurs, control should be transferred directly to EXCEPTION_ADDRESS, and the processor state (stack, registers, and so on) should be just as it is when a processor exception occurs. So if you want to use a jump instruction to reach EXCEPTION_ADDRESS, it should be a simple jump, not a jump to subroutine. For the 386, EXCEPTION_ADDRESS should be installed as an interrupt gate so that interrupts are masked while the handler runs. The gate should be at privilege level 0 (the most privileged level). The SPARC and 68k stubs are able to mask interrupts themselves without help from `exceptionHandler'. `void flush_i_cache()' On SPARC and SPARCLITE only, write this subroutine to flush the instruction cache, if any, on your target machine. If there is no instruction cache, this subroutine may be a no-op. On target machines that have instruction caches, GDB requires this function to make certain that the state of your program is stable. You must also make sure this library routine is available: `void *memset(void *, int, int)' This is the standard library function `memset' that sets an area of memory to a known value. If you have one of the free versions of `libc.a', `memset' can be found there; otherwise, you must either obtain it from your hardware manufacturer, or write your own. If you do not use the GNU C compiler, you may need other standard library subroutines as well; this varies from one stub to another, but in general the stubs are likely to use any of the common library subroutines which `GCC' generates as inline code.  File: gdb.info, Node: Debug Session, Prev: Bootstrapping, Up: Remote Stub 20.5.3 Putting it All Together ------------------------------ In summary, when your program is ready to debug, you must follow these steps. 1. Make sure you have defined the supporting low-level routines (*note What You Must Do for the Stub: Bootstrapping.): `getDebugChar', `putDebugChar', `flush_i_cache', `memset', `exceptionHandler'. 2. Insert these lines in your program's startup code, before the main procedure is called: set_debug_traps(); breakpoint(); On some machines, when a breakpoint trap is raised, the hardware automatically makes the PC point to the instruction after the breakpoint. If your machine doesn't do that, you may need to adjust `handle_exception' to arrange for it to return to the instruction after the breakpoint on this first invocation, so that your program doesn't keep hitting the initial breakpoint instead of making progress. 3. For the 680x0 stub only, you need to provide a variable called `exceptionHook'. Normally you just use: void (*exceptionHook)() = 0; but if before calling `set_debug_traps', you set it to point to a function in your program, that function is called when `GDB' continues after stopping on a trap (for example, bus error). The function indicated by `exceptionHook' is called with one parameter: an `int' which is the exception number. 4. Compile and link together: your program, the GDB debugging stub for your target architecture, and the supporting subroutines. 5. Make sure you have a serial connection between your target machine and the GDB host, and identify the serial port on the host. 6. Download your program to your target machine (or get it there by whatever means the manufacturer provides), and start it. 7. Start GDB on the host, and connect to the target (*note Connecting to a Remote Target: Connecting.).  File: gdb.info, Node: Configurations, Next: Controlling GDB, Prev: Remote Debugging, Up: Top 21 Configuration-Specific Information ************************************* While nearly all GDB commands are available for all native and cross versions of the debugger, there are some exceptions. This chapter describes things that are only available in certain configurations. There are three major categories of configurations: native configurations, where the host and target are the same, embedded operating system configurations, which are usually the same for several different processor architectures, and bare embedded processors, which are quite different from each other. * Menu: * Native:: * Embedded OS:: * Embedded Processors:: * Architectures::  File: gdb.info, Node: Native, Next: Embedded OS, Up: Configurations 21.1 Native =========== This section describes details specific to particular native configurations. * Menu: * BSD libkvm Interface:: Debugging BSD kernel memory images * Process Information:: Process information * DJGPP Native:: Features specific to the DJGPP port * Cygwin Native:: Features specific to the Cygwin port * Hurd Native:: Features specific to GNU Hurd * Darwin:: Features specific to Darwin * FreeBSD:: Features specific to FreeBSD  File: gdb.info, Node: BSD libkvm Interface, Next: Process Information, Up: Native 21.1.1 BSD libkvm Interface --------------------------- BSD-derived systems (FreeBSD/NetBSD/OpenBSD) have a kernel memory interface that provides a uniform interface for accessing kernel virtual memory images, including live systems and crash dumps. GDB uses this interface to allow you to debug live kernels and kernel crash dumps on many native BSD configurations. This is implemented as a special `kvm' debugging target. For debugging a live system, load the currently running kernel into GDB and connect to the `kvm' target: (gdb) target kvm For debugging crash dumps, provide the file name of the crash dump as an argument: (gdb) target kvm /var/crash/bsd.0 Once connected to the `kvm' target, the following commands are available: `kvm pcb' Set current context from the "Process Control Block" (PCB) address. `kvm proc' Set current context from proc address. This command isn't available on modern FreeBSD systems.  File: gdb.info, Node: Process Information, Next: DJGPP Native, Prev: BSD libkvm Interface, Up: Native 21.1.2 Process Information -------------------------- Some operating systems provide interfaces to fetch additional information about running processes beyond memory and per-thread register state. If GDB is configured for an operating system with a supported interface, the command `info proc' is available to report information about the process running your program, or about any process running on your system. One supported interface is a facility called `/proc' that can be used to examine the image of a running process using file-system subroutines. This facility is supported on GNU/Linux and Solaris systems. On FreeBSD and NetBSD systems, system control nodes are used to query process information. In addition, some systems may provide additional process information in core files. Note that a core file may include a subset of the information available from a live process. Process information is currently available from cores created on GNU/Linux and FreeBSD systems. `info proc' `info proc PROCESS-ID' Summarize available information about a process. If a process ID is specified by PROCESS-ID, display information about that process; otherwise display information about the program being debugged. The summary includes the debugged process ID, the command line used to invoke it, its current working directory, and its executable file's absolute file name. On some systems, PROCESS-ID can be of the form `[PID]/TID' which specifies a certain thread ID within a process. If the optional PID part is missing, it means a thread from the process being debugged (the leading `/' still needs to be present, or else GDB will interpret the number as a process ID rather than a thread ID). `info proc cmdline' Show the original command line of the process. This command is supported on GNU/Linux, FreeBSD and NetBSD. `info proc cwd' Show the current working directory of the process. This command is supported on GNU/Linux, FreeBSD and NetBSD. `info proc exe' Show the name of executable of the process. This command is supported on GNU/Linux, FreeBSD and NetBSD. `info proc files' Show the file descriptors open by the process. For each open file descriptor, GDB shows its number, type (file, directory, character device, socket), file pointer offset, and the name of the resource open on the descriptor. The resource name can be a file name (for files, directories, and devices) or a protocol followed by socket address (for network connections). This command is supported on FreeBSD. This example shows the open file descriptors for a process using a tty for standard input and output as well as two network sockets: (gdb) info proc files 22136 process 22136 Open files: FD Type Offset Flags Name text file - r-------- /usr/bin/ssh ctty chr - rw------- /dev/pts/20 cwd dir - r-------- /usr/home/john root dir - r-------- / 0 chr 0x32933a4 rw------- /dev/pts/20 1 chr 0x32933a4 rw------- /dev/pts/20 2 chr 0x32933a4 rw------- /dev/pts/20 3 socket 0x0 rw----n-- tcp4 10.0.1.2:53014 -> 10.0.1.10:22 4 socket 0x0 rw------- unix stream:/tmp/ssh-FIt89oAzOn5f/agent.2456 `info proc mappings' Report the memory address space ranges accessible in a process. On Solaris, FreeBSD and NetBSD systems, each memory range includes information on whether the process has read, write, or execute access rights to each range. On GNU/Linux, FreeBSD and NetBSD systems, each memory range includes the object file which is mapped to that range. `info proc stat' `info proc status' Show additional process-related information, including the user ID and group ID; virtual memory usage; the signals that are pending, blocked, and ignored; its TTY; its consumption of system and user time; its stack size; its `nice' value; etc. These commands are supported on GNU/Linux, FreeBSD and NetBSD. For GNU/Linux systems, see the `proc' man page for more information (type `man 5 proc' from your shell prompt). For FreeBSD and NetBSD systems, `info proc stat' is an alias for `info proc status'. `info proc all' Show all the information about the process described under all of the above `info proc' subcommands. `set procfs-trace' This command enables and disables tracing of `procfs' API calls. `show procfs-trace' Show the current state of `procfs' API call tracing. `set procfs-file FILE' Tell GDB to write `procfs' API trace to the named FILE. GDB appends the trace info to the previous contents of the file. The default is to display the trace on the standard output. `show procfs-file' Show the file to which `procfs' API trace is written. `proc-trace-entry' `proc-trace-exit' `proc-untrace-entry' `proc-untrace-exit' These commands enable and disable tracing of entries into and exits from the `syscall' interface. `info pidlist' For QNX Neutrino only, this command displays the list of all the processes and all the threads within each process. `info meminfo' For QNX Neutrino only, this command displays the list of all mapinfos.  File: gdb.info, Node: DJGPP Native, Next: Cygwin Native, Prev: Process Information, Up: Native 21.1.3 Features for Debugging DJGPP Programs -------------------------------------------- DJGPP is a port of the GNU development tools to MS-DOS and MS-Windows. DJGPP programs are 32-bit protected-mode programs that use the "DPMI" (DOS Protected-Mode Interface) API to run on top of real-mode DOS systems and their emulations. GDB supports native debugging of DJGPP programs, and defines a few commands specific to the DJGPP port. This subsection describes those commands. `info dos' This is a prefix of DJGPP-specific commands which print information about the target system and important OS structures. `info dos sysinfo' This command displays assorted information about the underlying platform: the CPU type and features, the OS version and flavor, the DPMI version, and the available conventional and DPMI memory. `info dos gdt' `info dos ldt' `info dos idt' These 3 commands display entries from, respectively, Global, Local, and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor tables are data structures which store a descriptor for each segment that is currently in use. The segment's selector is an index into a descriptor table; the table entry for that index holds the descriptor's base address and limit, and its attributes and access rights. A typical DJGPP program uses 3 segments: a code segment, a data segment (used for both data and the stack), and a DOS segment (which allows access to DOS/BIOS data structures and absolute addresses in conventional memory). However, the DPMI host will usually define additional segments in order to support the DPMI environment. These commands allow to display entries from the descriptor tables. Without an argument, all entries from the specified table are displayed. An argument, which should be an integer expression, means display a single entry whose index is given by the argument. For example, here's a convenient way to display information about the debugged program's data segment: `(gdb) info dos ldt $ds' `0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up)' This comes in handy when you want to see whether a pointer is outside the data segment's limit (i.e. "garbled"). `info dos pde' `info dos pte' These two commands display entries from, respectively, the Page Directory and the Page Tables. Page Directories and Page Tables are data structures which control how virtual memory addresses are mapped into physical addresses. A Page Table includes an entry for every page of memory that is mapped into the program's address space; there may be several Page Tables, each one holding up to 4096 entries. A Page Directory has up to 4096 entries, one each for every Page Table that is currently in use. Without an argument, `info dos pde' displays the entire Page Directory, and `info dos pte' displays all the entries in all of the Page Tables. An argument, an integer expression, given to the `info dos pde' command means display only that entry from the Page Directory table. An argument given to the `info dos pte' command means display entries from a single Page Table, the one pointed to by the specified entry in the Page Directory. These commands are useful when your program uses "DMA" (Direct Memory Access), which needs physical addresses to program the DMA controller. These commands are supported only with some DPMI servers. `info dos address-pte ADDR' This command displays the Page Table entry for a specified linear address. The argument ADDR is a linear address which should already have the appropriate segment's base address added to it, because this command accepts addresses which may belong to _any_ segment. For example, here's how to display the Page Table entry for the page where a variable `i' is stored: `(gdb) info dos address-pte __djgpp_base_address + (char *)&i' `Page Table entry for address 0x11a00d30:' `Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30' This says that `i' is stored at offset `0xd30' from the page whose physical base address is `0x02698000', and shows all the attributes of that page. Note that you must cast the addresses of variables to a `char *', since otherwise the value of `__djgpp_base_address', the base address of all variables and functions in a DJGPP program, will be added using the rules of C pointer arithmetic: if `i' is declared an `int', GDB will add 4 times the value of `__djgpp_base_address' to the address of `i'. Here's another example, it displays the Page Table entry for the transfer buffer: `(gdb) info dos address-pte *((unsigned *)&_go32_info_block + 3)' `Page Table entry for address 0x29110:' `Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110' (The `+ 3' offset is because the transfer buffer's address is the 3rd member of the `_go32_info_block' structure.) The output clearly shows that this DPMI server maps the addresses in conventional memory 1:1, i.e. the physical (`0x00029000' + `0x110') and linear (`0x29110') addresses are identical. This command is supported only with some DPMI servers. In addition to native debugging, the DJGPP port supports remote debugging via a serial data link. The following commands are specific to remote serial debugging in the DJGPP port of GDB. `set com1base ADDR' This command sets the base I/O port address of the `COM1' serial port. `set com1irq IRQ' This command sets the "Interrupt Request" (`IRQ') line to use for the `COM1' serial port. There are similar commands `set com2base', `set com3irq', etc. for setting the port address and the `IRQ' lines for the other 3 COM ports. The related commands `show com1base', `show com1irq' etc. display the current settings of the base address and the `IRQ' lines used by the COM ports. `info serial' This command prints the status of the 4 DOS serial ports. For each port, it prints whether it's active or not, its I/O base address and IRQ number, whether it uses a 16550-style FIFO, its baudrate, and the counts of various errors encountered so far.  File: gdb.info, Node: Cygwin Native, Next: Hurd Native, Prev: DJGPP Native, Up: Native 21.1.4 Features for Debugging MS Windows PE Executables ------------------------------------------------------- GDB supports native debugging of MS Windows programs, including DLLs with and without symbolic debugging information. MS-Windows programs that call `SetConsoleMode' to switch off the special meaning of the `Ctrl-C' keystroke cannot be interrupted by typing `C-c'. For this reason, GDB on MS-Windows supports `C-' as an alternative interrupt key sequence, which can be used to interrupt the debuggee even if it ignores `C-c'. There are various additional Cygwin-specific commands, described in this section. Working with DLLs that have no debugging symbols is described in *Note Non-debug DLL Symbols::. `info w32' This is a prefix of MS Windows-specific commands which print information about the target system and important OS structures. `info w32 selector' This command displays information returned by the Win32 API `GetThreadSelectorEntry' function. It takes an optional argument that is evaluated to a long value to give the information about this given selector. Without argument, this command displays information about the six segment registers. `info w32 thread-information-block' This command displays thread specific information stored in the Thread Information Block (readable on the X86 CPU family using `$fs' selector for 32-bit programs and `$gs' for 64-bit programs). `signal-event ID' This command signals an event with user-provided ID. Used to resume crashing process when attached to it using MS-Windows JIT debugging (AeDebug). To use it, create or edit the following keys in `HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug' and/or `HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\AeDebug' (for x86_64 versions): - `Debugger' (REG_SZ) -- a command to launch the debugger. Suggested command is: `FULLY-QUALIFIED-PATH-TO-GDB.EXE -ex "attach %ld" -ex "signal-event %ld" -ex "continue"'. The first `%ld' will be replaced by the process ID of the crashing process, the second `%ld' will be replaced by the ID of the event that blocks the crashing process, waiting for GDB to attach. - `Auto' (REG_SZ) -- either `1' or `0'. `1' will make the system run debugger specified by the Debugger key automatically, `0' will cause a dialog box with "OK" and "Cancel" buttons to appear, which allows the user to either terminate the crashing process (OK) or debug it (Cancel). `set cygwin-exceptions MODE' If MODE is `on', GDB will break on exceptions that happen inside the Cygwin DLL. If MODE is `off', GDB will delay recognition of exceptions, and may ignore some exceptions which seem to be caused by internal Cygwin DLL "bookkeeping". This option is meant primarily for debugging the Cygwin DLL itself; the default value is `off' to avoid annoying GDB users with false `SIGSEGV' signals. `show cygwin-exceptions' Displays whether GDB will break on exceptions that happen inside the Cygwin DLL itself. `set new-console MODE' If MODE is `on' the debuggee will be started in a new console on next start. If MODE is `off', the debuggee will be started in the same console as the debugger. `show new-console' Displays whether a new console is used when the debuggee is started. `set new-group MODE' This boolean value controls whether the debuggee should start a new group or stay in the same group as the debugger. This affects the way the Windows OS handles `Ctrl-C'. `show new-group' Displays current value of new-group boolean. `set debugevents' This boolean value adds debug output concerning kernel events related to the debuggee seen by the debugger. This includes events that signal thread and process creation and exit, DLL loading and unloading, console interrupts, and debugging messages produced by the Windows `OutputDebugString' API call. `set debugexec' This boolean value adds debug output concerning execute events (such as resume thread) seen by the debugger. `set debugexceptions' This boolean value adds debug output concerning exceptions in the debuggee seen by the debugger. `set debugmemory' This boolean value adds debug output concerning debuggee memory reads and writes by the debugger. `set shell' This boolean values specifies whether the debuggee is called via a shell or directly (default value is on). `show shell' Displays if the debuggee will be started with a shell. * Menu: * Non-debug DLL Symbols:: Support for DLLs without debugging symbols  File: gdb.info, Node: Non-debug DLL Symbols, Up: Cygwin Native 21.1.4.1 Support for DLLs without Debugging Symbols ................................................... Very often on windows, some of the DLLs that your program relies on do not include symbolic debugging information (for example, `kernel32.dll'). When GDB doesn't recognize any debugging symbols in a DLL, it relies on the minimal amount of symbolic information contained in the DLL's export table. This section describes working with such symbols, known internally to GDB as "minimal symbols". Note that before the debugged program has started execution, no DLLs will have been loaded. The easiest way around this problem is simply to start the program -- either by setting a breakpoint or letting the program run once to completion. 21.1.4.2 DLL Name Prefixes .......................... In keeping with the naming conventions used by the Microsoft debugging tools, DLL export symbols are made available with a prefix based on the DLL name, for instance `KERNEL32!CreateFileA'. The plain name is also entered into the symbol table, so `CreateFileA' is often sufficient. In some cases there will be name clashes within a program (particularly if the executable itself includes full debugging symbols) necessitating the use of the fully qualified name when referring to the contents of the DLL. Use single-quotes around the name to avoid the exclamation mark ("!") being interpreted as a language operator. Note that the internal name of the DLL may be all upper-case, even though the file name of the DLL is lower-case, or vice-versa. Since symbols within GDB are _case-sensitive_ this may cause some confusion. If in doubt, try the `info functions' and `info variables' commands or even `maint print msymbols' (*note Symbols::). Here's an example: (gdb) info function CreateFileA All functions matching regular expression "CreateFileA": Non-debugging symbols: 0x77e885f4 CreateFileA 0x77e885f4 KERNEL32!CreateFileA (gdb) info function ! All functions matching regular expression "!": Non-debugging symbols: 0x6100114c cygwin1!__assert 0x61004034 cygwin1!_dll_crt0@@0 0x61004240 cygwin1!dll_crt0(per_process *) [etc...] 21.1.4.3 Working with Minimal Symbols ..................................... Symbols extracted from a DLL's export table do not contain very much type information. All that GDB can do is guess whether a symbol refers to a function or variable depending on the linker section that contains the symbol. Also note that the actual contents of the memory contained in a DLL are not available unless the program is running. This means that you cannot examine the contents of a variable or disassemble a function within a DLL without a running program. Variables are generally treated as pointers and dereferenced automatically. For this reason, it is often necessary to prefix a variable name with the address-of operator ("&") and provide explicit type information in the command. Here's an example of the type of problem: (gdb) print 'cygwin1!__argv' 'cygwin1!__argv' has unknown type; cast it to its declared type (gdb) x 'cygwin1!__argv' 'cygwin1!__argv' has unknown type; cast it to its declared type And two possible solutions: (gdb) print ((char **)'cygwin1!__argv')[0] $2 = 0x22fd98 "/cygdrive/c/mydirectory/myprogram" (gdb) x/2x &'cygwin1!__argv' 0x610c0aa8 : 0x10021608 0x00000000 (gdb) x/x 0x10021608 0x10021608: 0x0022fd98 (gdb) x/s 0x0022fd98 0x22fd98: "/cygdrive/c/mydirectory/myprogram" Setting a break point within a DLL is possible even before the program starts execution. However, under these circumstances, GDB can't examine the initial instructions of the function in order to skip the function's frame set-up code. You can work around this by using "*&" to set the breakpoint at a raw memory address: (gdb) break *&'python22!PyOS_Readline' Breakpoint 1 at 0x1e04eff0 The author of these extensions is not entirely convinced that setting a break point within a shared DLL like `kernel32.dll' is completely safe.  File: gdb.info, Node: Hurd Native, Next: Darwin, Prev: Cygwin Native, Up: Native 21.1.5 Commands Specific to GNU Hurd Systems -------------------------------------------- This subsection describes GDB commands specific to the GNU Hurd native debugging. `set signals' `set sigs' This command toggles the state of inferior signal interception by GDB. Mach exceptions, such as breakpoint traps, are not affected by this command. `sigs' is a shorthand alias for `signals'. `show signals' `show sigs' Show the current state of intercepting inferior's signals. `set signal-thread' `set sigthread' This command tells GDB which thread is the `libc' signal thread. That thread is run when a signal is delivered to a running process. `set sigthread' is the shorthand alias of `set signal-thread'. `show signal-thread' `show sigthread' These two commands show which thread will run when the inferior is delivered a signal. `set stopped' This commands tells GDB that the inferior process is stopped, as with the `SIGSTOP' signal. The stopped process can be continued by delivering a signal to it. `show stopped' This command shows whether GDB thinks the debuggee is stopped. `set exceptions' Use this command to turn off trapping of exceptions in the inferior. When exception trapping is off, neither breakpoints nor single-stepping will work. To restore the default, set exception trapping on. `show exceptions' Show the current state of trapping exceptions in the inferior. `set task pause' This command toggles task suspension when GDB has control. Setting it to on takes effect immediately, and the task is suspended whenever GDB gets control. Setting it to off will take effect the next time the inferior is continued. If this option is set to off, you can use `set thread default pause on' or `set thread pause on' (see below) to pause individual threads. `show task pause' Show the current state of task suspension. `set task detach-suspend-count' This command sets the suspend count the task will be left with when GDB detaches from it. `show task detach-suspend-count' Show the suspend count the task will be left with when detaching. `set task exception-port' `set task excp' This command sets the task exception port to which GDB will forward exceptions. The argument should be the value of the "send rights" of the task. `set task excp' is a shorthand alias. `set noninvasive' This command switches GDB to a mode that is the least invasive as far as interfering with the inferior is concerned. This is the same as using `set task pause', `set exceptions', and `set signals' to values opposite to the defaults. `info send-rights' `info receive-rights' `info port-rights' `info port-sets' `info dead-names' `info ports' `info psets' These commands display information about, respectively, send rights, receive rights, port rights, port sets, and dead names of a task. There are also shorthand aliases: `info ports' for `info port-rights' and `info psets' for `info port-sets'. `set thread pause' This command toggles current thread suspension when GDB has control. Setting it to on takes effect immediately, and the current thread is suspended whenever GDB gets control. Setting it to off will take effect the next time the inferior is continued. Normally, this command has no effect, since when GDB has control, the whole task is suspended. However, if you used `set task pause off' (see above), this command comes in handy to suspend only the current thread. `show thread pause' This command shows the state of current thread suspension. `set thread run' This command sets whether the current thread is allowed to run. `show thread run' Show whether the current thread is allowed to run. `set thread detach-suspend-count' This command sets the suspend count GDB will leave on a thread when detaching. This number is relative to the suspend count found by GDB when it notices the thread; use `set thread takeover-suspend-count' to force it to an absolute value. `show thread detach-suspend-count' Show the suspend count GDB will leave on the thread when detaching. `set thread exception-port' `set thread excp' Set the thread exception port to which to forward exceptions. This overrides the port set by `set task exception-port' (see above). `set thread excp' is the shorthand alias. `set thread takeover-suspend-count' Normally, GDB's thread suspend counts are relative to the value GDB finds when it notices each thread. This command changes the suspend counts to be absolute instead. `set thread default' `show thread default' Each of the above `set thread' commands has a `set thread default' counterpart (e.g., `set thread default pause', `set thread default exception-port', etc.). The `thread default' variety of commands sets the default thread properties for all threads; you can then change the properties of individual threads with the non-default commands.  File: gdb.info, Node: Darwin, Next: FreeBSD, Prev: Hurd Native, Up: Native 21.1.6 Darwin ------------- GDB provides the following commands specific to the Darwin target: `set debug darwin NUM' When set to a non zero value, enables debugging messages specific to the Darwin support. Higher values produce more verbose output. `show debug darwin' Show the current state of Darwin messages. `set debug mach-o NUM' When set to a non zero value, enables debugging messages while GDB is reading Darwin object files. ("Mach-O" is the file format used on Darwin for object and executable files.) Higher values produce more verbose output. This is a command to diagnose problems internal to GDB and should not be needed in normal usage. `show debug mach-o' Show the current state of Mach-O file messages. `set mach-exceptions on' `set mach-exceptions off' On Darwin, faults are first reported as a Mach exception and are then mapped to a Posix signal. Use this command to turn on trapping of Mach exceptions in the inferior. This might be sometimes useful to better understand the cause of a fault. The default is off. `show mach-exceptions' Show the current state of exceptions trapping.  File: gdb.info, Node: FreeBSD, Prev: Darwin, Up: Native 21.1.7 FreeBSD -------------- When the ABI of a system call is changed in the FreeBSD kernel, this is implemented by leaving a compatibility system call using the old ABI at the existing number and allocating a new system call number for the version using the new ABI. As a convenience, when a system call is caught by name (*note catch syscall::), compatibility system calls are also caught. For example, FreeBSD 12 introduced a new variant of the `kevent' system call and catching the `kevent' system call by name catches both variants: (gdb) catch syscall kevent Catchpoint 1 (syscalls 'freebsd11_kevent' [363] 'kevent' [560]) (gdb)  File: gdb.info, Node: Embedded OS, Next: Embedded Processors, Prev: Native, Up: Configurations 21.2 Embedded Operating Systems =============================== This section describes configurations involving the debugging of embedded operating systems that are available for several different architectures. GDB includes the ability to debug programs running on various real-time operating systems.  File: gdb.info, Node: Embedded Processors, Next: Architectures, Prev: Embedded OS, Up: Configurations 21.3 Embedded Processors ======================== This section goes into details specific to particular embedded configurations. Whenever a specific embedded processor has a simulator, GDB allows to send an arbitrary command to the simulator. `sim COMMAND' Send an arbitrary COMMAND string to the simulator. Consult the documentation for the specific simulator in use for information about acceptable commands. * Menu: * ARC:: Synopsys ARC * ARM:: ARM * BPF:: eBPF * M68K:: Motorola M68K * MicroBlaze:: Xilinx MicroBlaze * MIPS Embedded:: MIPS Embedded * OpenRISC 1000:: OpenRISC 1000 (or1k) * PowerPC Embedded:: PowerPC Embedded * AVR:: Atmel AVR * CRIS:: CRIS * Super-H:: Renesas Super-H  File: gdb.info, Node: ARC, Next: ARM, Up: Embedded Processors 21.3.1 Synopsys ARC ------------------- GDB provides the following ARC-specific commands: `set debug arc' Control the level of ARC specific debug messages. Use 0 for no messages (the default), 1 for debug messages, and 2 for even more debug messages. `show debug arc' Show the level of ARC specific debugging in operation. `maint print arc arc-instruction ADDRESS' Print internal disassembler information about instruction at a given address.  File: gdb.info, Node: ARM, Next: BPF, Prev: ARC, Up: Embedded Processors 21.3.2 ARM ---------- GDB provides the following ARM-specific commands: `set arm disassembler' This commands selects from a list of disassembly styles. The `"std"' style is the standard style. `show arm disassembler' Show the current disassembly style. `set arm apcs32' This command toggles ARM operation mode between 32-bit and 26-bit. `show arm apcs32' Display the current usage of the ARM 32-bit mode. `set arm fpu FPUTYPE' This command sets the ARM floating-point unit (FPU) type. The argument FPUTYPE can be one of these: `auto' Determine the FPU type by querying the OS ABI. `softfpa' Software FPU, with mixed-endian doubles on little-endian ARM processors. `fpa' GCC-compiled FPA co-processor. `softvfp' Software FPU with pure-endian doubles. `vfp' VFP co-processor. `show arm fpu' Show the current type of the FPU. `set arm abi' This command forces GDB to use the specified ABI. `show arm abi' Show the currently used ABI. `set arm fallback-mode (arm|thumb|auto)' GDB uses the symbol table, when available, to determine whether instructions are ARM or Thumb. This command controls GDB's default behavior when the symbol table is not available. The default is `auto', which causes GDB to use the current execution mode (from the `T' bit in the `CPSR' register). `show arm fallback-mode' Show the current fallback instruction mode. `set arm force-mode (arm|thumb|auto)' This command overrides use of the symbol table to determine whether instructions are ARM or Thumb. The default is `auto', which causes GDB to use the symbol table and then the setting of `set arm fallback-mode'. `show arm force-mode' Show the current forced instruction mode. `set arm unwind-secure-frames' This command enables unwinding from Non-secure to Secure mode on Cortex-M with Security extension. This can trigger security exceptions when unwinding the exception stack. It is enabled by default. `show arm unwind-secure-frames' Show whether unwinding from Non-secure to Secure mode is enabled. `set debug arm' Toggle whether to display ARM-specific debugging messages from the ARM target support subsystem. `show debug arm' Show whether ARM-specific debugging messages are enabled. `target sim [SIMARGS] ...' The GDB ARM simulator accepts the following optional arguments. `--swi-support=TYPE' Tell the simulator which SWI interfaces to support. The argument TYPE may be a comma separated list of the following values. The default value is `all'. `none' `demon' `angel' `redboot' `all'  File: gdb.info, Node: BPF, Next: M68K, Prev: ARM, Up: Embedded Processors 21.3.3 BPF ---------- `target sim [SIMARGS] ...' The GDB BPF simulator accepts the following optional arguments. `--skb-data-offset=OFFSET' Tell the simulator the offset, measured in bytes, of the `skb_data' field in the kernel `struct sk_buff' structure. This offset is used by some BPF specific-purpose load/store instructions. Defaults to 0.  File: gdb.info, Node: M68K, Next: MicroBlaze, Prev: BPF, Up: Embedded Processors 21.3.4 M68k ----------- The Motorola m68k configuration includes ColdFire support.  File: gdb.info, Node: MicroBlaze, Next: MIPS Embedded, Prev: M68K, Up: Embedded Processors 21.3.5 MicroBlaze ----------------- The MicroBlaze is a soft-core processor supported on various Xilinx FPGAs, such as Spartan or Virtex series. Boards with these processors usually have JTAG ports which connect to a host system running the Xilinx Embedded Development Kit (EDK) or Software Development Kit (SDK). This host system is used to download the configuration bitstream to the target FPGA. The Xilinx Microprocessor Debugger (XMD) program communicates with the target board using the JTAG interface and presents a `gdbserver' interface to the board. By default `xmd' uses port `1234'. (While it is possible to change this default port, it requires the use of undocumented `xmd' commands. Contact Xilinx support if you need to do this.) Use these GDB commands to connect to the MicroBlaze target processor. `target remote :1234' Use this command to connect to the target if you are running GDB on the same system as `xmd'. `target remote XMD-HOST:1234' Use this command to connect to the target if it is connected to `xmd' running on a different system named XMD-HOST. `load' Use this command to download a program to the MicroBlaze target. `set debug microblaze N' Enable MicroBlaze-specific debugging messages if non-zero. `show debug microblaze N' Show MicroBlaze-specific debugging level.  File: gdb.info, Node: MIPS Embedded, Next: OpenRISC 1000, Prev: MicroBlaze, Up: Embedded Processors 21.3.6 MIPS Embedded -------------------- GDB supports these special commands for MIPS targets: `set mipsfpu double' `set mipsfpu single' `set mipsfpu none' `set mipsfpu auto' `show mipsfpu' If your target board does not support the MIPS floating point coprocessor, you should use the command `set mipsfpu none' (if you need this, you may wish to put the command in your GDB init file). This tells GDB how to find the return value of functions which return floating point values. It also allows GDB to avoid saving the floating point registers when calling functions on the board. If you are using a floating point coprocessor with only single precision floating point support, as on the R4650 processor, use the command `set mipsfpu single'. The default double precision floating point coprocessor may be selected using `set mipsfpu double'. In previous versions the only choices were double precision or no floating point, so `set mipsfpu on' will select double precision and `set mipsfpu off' will select no floating point. As usual, you can inquire about the `mipsfpu' variable with `show mipsfpu'.  File: gdb.info, Node: OpenRISC 1000, Next: PowerPC Embedded, Prev: MIPS Embedded, Up: Embedded Processors 21.3.7 OpenRISC 1000 -------------------- The OpenRISC 1000 provides a free RISC instruction set architecture. It is mainly provided as a soft-core which can run on Xilinx, Altera and other FPGA's. GDB for OpenRISC supports the below commands when connecting to a target: `target sim' Runs the builtin CPU simulator which can run very basic programs but does not support most hardware functions like MMU. For more complex use cases the user is advised to run an external target, and connect using `target remote'. Example: `target sim' `set debug or1k' Toggle whether to display OpenRISC-specific debugging messages from the OpenRISC target support subsystem. `show debug or1k' Show whether OpenRISC-specific debugging messages are enabled.  File: gdb.info, Node: PowerPC Embedded, Next: AVR, Prev: OpenRISC 1000, Up: Embedded Processors 21.3.8 PowerPC Embedded ----------------------- GDB supports using the DVC (Data Value Compare) register to implement in hardware simple hardware watchpoint conditions of the form: (gdb) watch ADDRESS|VARIABLE \ if ADDRESS|VARIABLE == CONSTANT EXPRESSION The DVC register will be automatically used when GDB detects such pattern in a condition expression, and the created watchpoint uses one debug register (either the `exact-watchpoints' option is on and the variable is scalar, or the variable has a length of one byte). This feature is available in native GDB running on a Linux kernel version 2.6.34 or newer. When running on PowerPC embedded processors, GDB automatically uses ranged hardware watchpoints, unless the `exact-watchpoints' option is on, in which case watchpoints using only one debug register are created when watching variables of scalar types. You can create an artificial array to watch an arbitrary memory region using one of the following commands (*note Expressions::): (gdb) watch *((char *) ADDRESS)@@LENGTH (gdb) watch {char[LENGTH]} ADDRESS PowerPC embedded processors support masked watchpoints. See the discussion about the `mask' argument in *Note Set Watchpoints::. PowerPC embedded processors support hardware accelerated "ranged breakpoints". A ranged breakpoint stops execution of the inferior whenever it executes an instruction at any address within the range it was set at. To set a ranged breakpoint in GDB, use the `break-range' command. GDB provides the following PowerPC-specific commands: `break-range START-LOCSPEC, END-LOCSPEC' Set a breakpoint for an address range given by START-LOCSPEC and END-LOCSPEC, which are location specs. *Note Location Specifications::, for a list of all the possible forms of location specs. GDB resolves both START-LOCSPEC and END-LOCSPEC, and uses the addresses of the resolved code locations as start and end addresses of the range to break at. The breakpoint will stop execution of the inferior whenever it executes an instruction at any address between the start and end addresses, inclusive. If either START-LOCSPEC or END-LOCSPEC resolve to multiple code locations in the program, then the command aborts with an error without creating a breakpoint. `set powerpc soft-float' `show powerpc soft-float' Force GDB to use (or not use) a software floating point calling convention. By default, GDB selects the calling convention based on the selected architecture and the provided executable file. `set powerpc vector-abi' `show powerpc vector-abi' Force GDB to use the specified calling convention for vector arguments and return values. The valid options are `auto'; `generic', to avoid vector registers even if they are present; `altivec', to use AltiVec registers; and `spe' to use SPE registers. By default, GDB selects the calling convention based on the selected architecture and the provided executable file. `set powerpc exact-watchpoints' `show powerpc exact-watchpoints' Allow GDB to use only one debug register when watching a variable of scalar type, thus assuming that the variable is accessed through the address of its first byte.  File: gdb.info, Node: AVR, Next: CRIS, Prev: PowerPC Embedded, Up: Embedded Processors 21.3.9 Atmel AVR ---------------- When configured for debugging the Atmel AVR, GDB supports the following AVR-specific commands: `info io_registers' This command displays information about the AVR I/O registers. For each register, GDB prints its number and value.  File: gdb.info, Node: CRIS, Next: Super-H, Prev: AVR, Up: Embedded Processors 21.3.10 CRIS ------------ When configured for debugging CRIS, GDB provides the following CRIS-specific commands: `set cris-version VER' Set the current CRIS version to VER, either `10' or `32'. The CRIS version affects register names and sizes. This command is useful in case autodetection of the CRIS version fails. `show cris-version' Show the current CRIS version. `set cris-dwarf2-cfi' Set the usage of DWARF-2 CFI for CRIS debugging. The default is `on'. Change to `off' when using `gcc-cris' whose version is below `R59'. `show cris-dwarf2-cfi' Show the current state of using DWARF-2 CFI. `set cris-mode MODE' Set the current CRIS mode to MODE. It should only be changed when debugging in guru mode, in which case it should be set to `guru' (the default is `normal'). `show cris-mode' Show the current CRIS mode.  File: gdb.info, Node: Super-H, Prev: CRIS, Up: Embedded Processors 21.3.11 Renesas Super-H ----------------------- For the Renesas Super-H processor, GDB provides these commands: `set sh calling-convention CONVENTION' Set the calling-convention used when calling functions from GDB. Allowed values are `gcc', which is the default setting, and `renesas'. With the `gcc' setting, functions are called using the GCC calling convention. If the DWARF-2 information of the called function specifies that the function follows the Renesas calling convention, the function is called using the Renesas calling convention. If the calling convention is set to `renesas', the Renesas calling convention is always used, regardless of the DWARF-2 information. This can be used to override the default of `gcc' if debug information is missing, or the compiler does not emit the DWARF-2 calling convention entry for a function. `show sh calling-convention' Show the current calling convention setting.  File: gdb.info, Node: Architectures, Prev: Embedded Processors, Up: Configurations 21.4 Architectures ================== This section describes characteristics of architectures that affect all uses of GDB with the architecture, both native and cross. * Menu: * AArch64:: * x86:: * Alpha:: * MIPS:: * HPPA:: HP PA architecture * PowerPC:: * Nios II:: * Sparc64:: * S12Z:: * AMD GPU:: AMD GPU architectures  File: gdb.info, Node: AArch64, Next: x86, Up: Architectures 21.4.1 AArch64 -------------- When GDB is debugging the AArch64 architecture, it provides the following special commands: `set debug aarch64' This command determines whether AArch64 architecture-specific debugging messages are to be displayed. `show debug aarch64' Show whether AArch64 debugging messages are displayed. 21.4.1.1 AArch64 SVE. ..................... When GDB is debugging the AArch64 architecture, if the Scalable Vector Extension (SVE) is present, then GDB will provide the vector registers `$z0' through `$z31', vector predicate registers `$p0' through `$p15', and the `$ffr' register. In addition, the pseudo register `$vg' will be provided. This is the vector granule for the current thread and represents the number of 64-bit chunks in an SVE `z' register. If the vector length changes, then the `$vg' register will be updated, but the lengths of the `z' and `p' registers will not change. This is a known limitation of GDB and does not affect the execution of the target process. For SVE, the following definitions are used throughout GDB's source code and in this document: * VL: The vector length, in bytes. It defines the size of each `Z' register. * VQ: The number of 128 bit units in VL. This is mostly used internally by GDB and the Linux Kernel. * VG: The number of 64 bit units in VL. This is mostly used internally by GDB and the Linux Kernel. 21.4.1.2 AArch64 SME. ..................... The Scalable Matrix Extension (SME (https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/scalable-matrix-extension-armv9-a-architecture)) is an AArch64 architecture extension that expands on the concept of the Scalable Vector Extension (SVE (https://developer.arm.com/documentation/101726/4-0/Learn-about-the-Scalable-Vector-Extension--SVE-/What-is-the-Scalable-Vector-Extension-)) by providing a 2-dimensional register `ZA', which is a square matrix of variable size, just like SVE provides a group of vector registers of variable size. Similarly to SVE, where the size of each `Z' register is directly related to the vector length (VL for short), the SME `ZA' matrix register's size is directly related to the streaming vector length (SVL for short). *Note vl::. *Note svl::. The `ZA' register state can be either active or inactive, if it is not in use. SME also introduces a new execution mode called streaming SVE mode (streaming mode for short). When streaming mode is enabled, the program supports execution of SVE2 instructions and the SVE registers will have vector length SVL. When streaming mode is disabled, the SVE registers have vector length VL. For more information about SME and SVE, please refer to official architecture documentation (https://developer.arm.com/documentation/ddi0487/latest). The following definitions are used throughout GDB's source code and in this document: * SVL: The streaming vector length, in bytes. It defines the size of each dimension of the 2-dimensional square `ZA' matrix. The total size of `ZA' is therefore SVL by SVL. When streaming mode is enabled, it defines the size of the SVE registers as well. * SVQ: The number of 128 bit units in SVL, also known as streaming vector granule. This is mostly used internally by GDB and the Linux Kernel. * SVG: The number of 64 bit units in SVL. This is mostly used internally by GDB and the Linux Kernel. When GDB is debugging the AArch64 architecture, if the Scalable Matrix Extension (SME) is present, then GDB will make the `ZA' register available. GDB will also make the `SVG' register and `SVCR' pseudo-register available. The `ZA' register is a 2-dimensional square SVL by SVL matrix of bytes. To simplify the representation and access to the `ZA' register in GDB, it is defined as a vector of SVLxSVL bytes. If the user wants to index the `ZA' register as a matrix, it is possible to reference `ZA' as `ZA[I][J]', where I is the row number and J is the column number. The `SVG' register always contains the streaming vector granule (SVG) for the current thread. From the value of register `SVG' we can easily derive the SVL value. The `SVCR' pseudo-register (streaming vector control register) is a status register that holds two state bits: SM in bit 0 and ZA in bit 1. If the SM bit is 1, it means the current thread is in streaming mode, and the SVE registers will use SVL for their sizes. If the SM bit is 0, the current thread is not in streaming mode, and the SVE registers will use VL for their sizes. *Note vl::. If the ZA bit is 1, it means the `ZA' register is being used and has meaningful contents. If the ZA bit is 0, the `ZA' register is unavailable and its contents are undefined. For convenience and simplicity, if the ZA bit is 0, the `ZA' register and all of its pseudo-registers will read as zero. If SVL changes during the execution of a program, then the `ZA' register size and the bits in the `SVCR' pseudo-register will be updated to reflect it. It is possible for users to change SVL during the execution of a program by modifying the `SVG' register value. Whenever the `SVG' register is modified with a new value, the following will be observed: * The ZA and SM bits will be cleared in the `SVCR' pseudo-register. * The `ZA' register will have a new size and its state will be cleared, forcing its contents and the contents of all of its pseudo-registers back to zero. * If the SM bit was 1, the SVE registers will be reset to having their sizes based on VL as opposed to SVL. If the SM bit was 0 prior to modifying the `SVG' register, there will be no observable effect on the SVE registers. The possible values for the `SVG' register are 2, 4, 8, 16, 32. These numbers correspond to streaming vector length (SVL) values of 16 bytes, 32 bytes, 64 bytes, 128 bytes and 256 bytes respectively. The minimum size of the `ZA' register is 16 x 16 (256) bytes, and the maximum size is 256 x 256 (65536) bytes. In streaming mode, with bit SM set, the size of the `ZA' register is the size of all the SVE `Z' registers combined. The `ZA' register can also be accessed using tiles and tile slices. Tile pseudo-registers are square, 2-dimensional sub-arrays of elements within the `ZA' register. The tile pseudo-registers have the following naming pattern: `ZA'. There is a total of 31 `ZA' tile pseudo-registers. They are `ZA0B', `ZA0H' through `ZA1H', `ZA0S' through `ZA3S', `ZA0D' through `ZA7D' and `ZA0Q' through `ZA15Q'. Tile slice pseudo-registers are vectors of horizontally or vertically contiguous elements within the `ZA' register. The tile slice pseudo-registers have the following naming pattern: `ZA '. There are up to 16 tiles (0 ~ 15), the direction can be either `v' (vertical) or `h' (horizontal), the qualifiers can be `b' (byte), `h' (halfword), `s' (word), `d' (doubleword) and `q' (quadword) and there are up to 256 slices (0 ~ 255) depending on the value of SVL. The number of slices is the same as the value of SVL. The number of available tile slice pseudo-registers can be large. For a minimum SVL of 16 bytes, there are 5 (number of qualifiers) x 2 (number of directions) x 16 (SVL) pseudo-registers. For the maximum SVL of 256 bytes, there are 5 x 2 x 256 pseudo-registers. When listing all the available registers, users will see the currently-available `ZA' pseudo-registers. Pseudo-registers that don't exist for a given SVL value will not be displayed. For more information on SME and its terminology, please refer to the Arm Architecture Reference Manual Supplement (https://developer.arm.com/documentation/ddi0616/aa/), The Scalable Matrix Extension (SME), for Armv9-A. Some features are still under development and rely on ACLE (https://github.com/ARM-software/acle/releases/latest) and ABI (https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst) definitions, so there are known limitations to the current SME support in GDB. One such example is calling functions in the program being debugged by GDB. Such calls are not SME-aware and thus don't take into account the `SVCR' pseudo-register bits nor the `ZA' register contents. *Note Calling::. The lazy saving scheme (https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#the-za-lazy-saving-scheme) involving the `TPIDR2' register is not yet supported by GDB, though the `TPIDR2' register is known and supported by GDB. Lastly, an important limitation for `gdbserver' is its inability to communicate SVL changes to GDB. This means `gdbserver', even though it is capable of adjusting its internal caches to reflect a change in the value of SVL mid-execution, will operate with a potentially different SVL value compared to GDB. This can lead to GDB showing incorrect values for the `ZA' register and incorrect values for SVE registers (when in streaming mode). This is the same limitation we have for the SVE registers, and there are plans to address this limitation going forward. 21.4.1.3 AArch64 SME2. ...................... The Scalable Matrix Extension 2 is an AArch64 architecture extension that further expands the SME extension with the following: * The ability to address the `ZA' array through groups of one-dimensional `ZA' array vectors, as opposed to `ZA' tiles with 2 dimensions. * Instructions to operate on groups of SVE `Z' registers and `ZA' array vectors. * A new 512 bit `ZT0' lookup table register, for data decompression. When GDB is debugging the AArch64 architecture, if the Scalable Matrix Extension 2 (SME2) is present, then GDB will make the `ZT0' register available. The `ZT0' register is only considered active when the `ZA' register state is active, therefore when the ZA bit of the `SVCR' is 1. When the ZA bit of `SVCR' is 0, that means the `ZA' register state is not active, which means the `ZT0' register state is also not active. When `ZT0' is not active, it is comprised of zeroes, just like `ZA'. Similarly to the `ZA' register, if the `ZT0' state is not active and the user attempts to modify its value such that any of its bytes is non-zero, then GDB will initialize the `ZA' register state as well, which means the `SVCR' ZA bit gets set to 1. For more information about SME2, please refer to the official architecture documentation (https://developer.arm.com/documentation/ddi0487/latest). 21.4.1.4 AArch64 Pointer Authentication. ........................................ When GDB is debugging the AArch64 architecture, and the program is using the v8.3-A feature Pointer Authentication (PAC), then whenever the link register `$lr' is pointing to an PAC function its value will be masked. When GDB prints a backtrace, any addresses that required unmasking will be postfixed with the marker [PAC]. When using the MI, this is printed as part of the `addr_flags' field. 21.4.1.5 AArch64 Memory Tagging Extension. .......................................... When GDB is debugging the AArch64 architecture, the program is using the v8.5-A feature Memory Tagging Extension (MTE) and there is support in the kernel for MTE, GDB will make memory tagging functionality available for inspection and editing of logical and allocation tags. *Note Memory Tagging::. To aid debugging, GDB will output additional information when SIGSEGV signals are generated as a result of memory tag failures. If the tag violation is synchronous, the following will be shown: Program received signal SIGSEGV, Segmentation fault Memory tag violation while accessing address 0x0500fffff7ff8000 Allocation tag 0x1 Logical tag 0x5. If the tag violation is asynchronous, the fault address is not available. In this case GDB will show the following: Program received signal SIGSEGV, Segmentation fault Memory tag violation Fault address unavailable. A special register, `tag_ctl', is made available through the `org.gnu.gdb.aarch64.mte' feature. This register exposes some options that can be controlled at runtime and emulates the `prctl' option `PR_SET_TAGGED_ADDR_CTRL'. For further information, see the documentation in the Linux kernel. GDB supports dumping memory tag data to core files through the `gcore' command and reading memory tag data from core files generated by the `gcore' command or the Linux kernel. When a process uses memory-mapped pages protected by memory tags (for example, AArch64 MTE), this additional information will be recorded in the core file in the event of a crash or if GDB generates a core file from the current process state. The memory tag data will be used so developers can display the memory tags from a particular memory region (using the `m' modifier to the `x' command, using the `print' command or using the various `memory-tag' subcommands. In the case of a crash, GDB will attempt to retrieve the memory tag information automatically from the core file, and will show one of the above messages depending on whether the synchronous or asynchronous mode is selected. *Note Memory Tagging::. *Note Memory::.  File: gdb.info, Node: x86, Next: Alpha, Prev: AArch64, Up: Architectures 21.4.2 x86 ---------- `set struct-convention MODE' Set the convention used by the inferior to return `struct's and `union's from functions to MODE. Possible values of MODE are `"pcc"', `"reg"', and `"default"' (the default). `"default"' or `"pcc"' means that `struct's are returned on the stack, while `"reg"' means that a `struct' or a `union' whose size is 1, 2, 4, or 8 bytes will be returned in a register. `show struct-convention' Show the current setting of the convention to return `struct's from functions. 21.4.2.1 Intel "Memory Protection Extensions" (MPX). .................................................... Memory Protection Extension (MPX) adds the bound registers `BND0' (1) through `BND3'. Bound registers store a pair of 64-bit values which are the lower bound and upper bound. Bounds are effective addresses or memory locations. The upper bounds are architecturally represented in 1's complement form. A bound having lower bound = 0, and upper bound = 0 (1's complement of all bits set) will allow access to the entire address space. `BND0' through `BND3' are represented in GDB as `bnd0raw' through `bnd3raw'. Pseudo registers `bnd0' through `bnd3' display the upper bound performing the complement of one operation on the upper bound value, i.e. when upper bound in `bnd0raw' is 0 in the GDB `bnd0' it will be `0xfff...'. In this sense it can also be noted that the upper bounds are inclusive. As an example, assume that the register BND0 holds bounds for a pointer having access allowed for the range between 0x32 and 0x71. The values present on bnd0raw and bnd registers are presented as follows: bnd0raw = {0x32, 0xffffffff8e} bnd0 = {lbound = 0x32, ubound = 0x71} : size 64 This way the raw value can be accessed via bnd0raw...bnd3raw. Any change on bnd0...bnd3 or bnd0raw...bnd3raw is reflect on its counterpart. When the bnd0...bnd3 registers are displayed via Python, the display includes the memory size, in bits, accessible to the pointer. Bounds can also be stored in bounds tables, which are stored in application memory. These tables store bounds for pointers by specifying the bounds pointer's value along with its bounds. Evaluating and changing bounds located in bound tables is therefore interesting while investigating bugs on MPX context. GDB provides commands for this purpose: `show mpx bound POINTER' Display bounds of the given POINTER. `set mpx bound POINTER, LBOUND, UBOUND' Set the bounds of a pointer in the bound table. This command takes three parameters: POINTER is the pointers whose bounds are to be changed, LBOUND and UBOUND are new values for lower and upper bounds respectively. Both commands are deprecated and will be removed in future versions of GDB. MPX itself was listed as removed by Intel in 2019. When you call an inferior function on an Intel MPX enabled program, GDB sets the inferior's bound registers to the init (disabled) state before calling the function. As a consequence, bounds checks for the pointer arguments passed to the function will always pass. This is necessary because when you call an inferior function, the program is usually in the middle of the execution of other function. Since at that point bound registers are in an arbitrary state, not clearing them would lead to random bound violations in the called function. You can still examine the influence of the bound registers on the execution of the called function by stopping the execution of the called function at its prologue, setting bound registers, and continuing the execution. For example: $ break *upper Breakpoint 2 at 0x4009de: file i386-mpx-call.c, line 47. $ print upper (a, b, c, d, 1) Breakpoint 2, upper (a=0x0, b=0x6e0000005b, c=0x0, d=0x0, len=48).... $ print $bnd0 {lbound = 0x0, ubound = ffffffff} : size -1 At this last step the value of bnd0 can be changed for investigation of bound violations caused along the execution of the call. In order to know how to set the bound registers or bound table for the call consult the ABI. 21.4.2.2 x87 registers ...................... GDB provides access to the x87 state through the following registers: * `$st0' to `st7': `ST(0)' to `ST(7)' floating-point registers * `$fctrl': control word register (`FCW') * `$fstat': status word register (`FSW') * `$ftag': tag word (`FTW') * `$fiseg': last instruction pointer segment * `$fioff': last instruction pointer * `$foseg': last data pointer segment * `$fooff': last data pointer * `$fop': last opcode ---------- Footnotes ---------- (1) The register named with capital letters represent the architecture registers.  File: gdb.info, Node: Alpha, Next: MIPS, Prev: x86, Up: Architectures 21.4.3 Alpha ------------ See the following section.  File: gdb.info, Node: MIPS, Next: HPPA, Prev: Alpha, Up: Architectures 21.4.4 MIPS ----------- Alpha- and MIPS-based computers use an unusual stack frame, which sometimes requires GDB to search backward in the object code to find the beginning of a function. To improve response time (especially for embedded applications, where GDB may be restricted to a slow serial line for this search) you may want to limit the size of this search, using one of these commands: `set heuristic-fence-post LIMIT' Restrict GDB to examining at most LIMIT bytes in its search for the beginning of a function. A value of 0 (the default) means there is no limit. However, except for 0, the larger the limit the more bytes `heuristic-fence-post' must search and therefore the longer it takes to run. You should only need to use this command when debugging a stripped executable. `show heuristic-fence-post' Display the current limit. These commands are available _only_ when GDB is configured for debugging programs on Alpha or MIPS processors. Several MIPS-specific commands are available when debugging MIPS programs: `set mips abi ARG' Tell GDB which MIPS ABI is used by the inferior. Possible values of ARG are: `auto' The default ABI associated with the current binary (this is the default). `o32' `o64' `n32' `n64' `eabi32' `eabi64' `show mips abi' Show the MIPS ABI used by GDB to debug the inferior. `set mips compression ARG' Tell GDB which MIPS compressed ISA (Instruction Set Architecture) encoding is used by the inferior. GDB uses this for code disassembly and other internal interpretation purposes. This setting is only referred to when no executable has been associated with the debugging session or the executable does not provide information about the encoding it uses. Otherwise this setting is automatically updated from information provided by the executable. Possible values of ARG are `mips16' and `micromips'. The default compressed ISA encoding is `mips16', as executables containing MIPS16 code frequently are not identified as such. This setting is "sticky"; that is, it retains its value across debugging sessions until reset either explicitly with this command or implicitly from an executable. The compiler and/or assembler typically add symbol table annotations to identify functions compiled for the MIPS16 or microMIPS ISAs. If these function-scope annotations are present, GDB uses them in preference to the global compressed ISA encoding setting. `show mips compression' Show the MIPS compressed ISA encoding used by GDB to debug the inferior. `set mipsfpu' `show mipsfpu' *Note set mipsfpu: MIPS Embedded. `set mips mask-address ARG' This command determines whether the most-significant 32 bits of 64-bit MIPS addresses are masked off. The argument ARG can be `on', `off', or `auto'. The latter is the default setting, which lets GDB determine the correct value. `show mips mask-address' Show whether the upper 32 bits of MIPS addresses are masked off or not. `set remote-mips64-transfers-32bit-regs' This command controls compatibility with 64-bit MIPS targets that transfer data in 32-bit quantities. If you have an old MIPS 64 target that transfers 32 bits for some registers, like SR and FSR, and 64 bits for other registers, set this option to `on'. `show remote-mips64-transfers-32bit-regs' Show the current setting of compatibility with older MIPS 64 targets. `set debug mips' This command turns on and off debugging messages for the MIPS-specific target code in GDB. `show debug mips' Show the current setting of MIPS debugging messages.  File: gdb.info, Node: HPPA, Next: PowerPC, Prev: MIPS, Up: Architectures 21.4.5 HPPA ----------- When GDB is debugging the HP PA architecture, it provides the following special commands: `set debug hppa' This command determines whether HPPA architecture-specific debugging messages are to be displayed. `show debug hppa' Show whether HPPA debugging messages are displayed. `maint print unwind ADDRESS' This command displays the contents of the unwind table entry at the given ADDRESS.  File: gdb.info, Node: PowerPC, Next: Nios II, Prev: HPPA, Up: Architectures 21.4.6 PowerPC -------------- When GDB is debugging the PowerPC architecture, it provides a set of pseudo-registers to enable inspection of 128-bit wide Decimal Floating Point numbers stored in the floating point registers. These values must be stored in two consecutive registers, always starting at an even register like `f0' or `f2'. The pseudo-registers go from `$dl0' through `$dl15', and are formed by joining the even/odd register pairs `f0' and `f1' for `$dl0', `f2' and `f3' for `$dl1' and so on. For POWER7 processors, GDB provides a set of pseudo-registers, the 64-bit wide Extended Floating Point Registers (`f32' through `f63').  File: gdb.info, Node: Nios II, Next: Sparc64, Prev: PowerPC, Up: Architectures 21.4.7 Nios II -------------- When GDB is debugging the Nios II architecture, it provides the following special commands: `set debug nios2' This command turns on and off debugging messages for the Nios II target code in GDB. `show debug nios2' Show the current setting of Nios II debugging messages.  File: gdb.info, Node: Sparc64, Next: S12Z, Prev: Nios II, Up: Architectures 21.4.8 Sparc64 -------------- 21.4.8.1 ADI Support .................... The M7 processor supports an Application Data Integrity (ADI) feature that detects invalid data accesses. When software allocates memory and enables ADI on the allocated memory, it chooses a 4-bit version number, sets the version in the upper 4 bits of the 64-bit pointer to that data, and stores the 4-bit version in every cacheline of that data. Hardware saves the latter in spare bits in the cache and memory hierarchy. On each load and store, the processor compares the upper 4 VA (virtual address) bits to the cacheline's version. If there is a mismatch, the processor generates a version mismatch trap which can be either precise or disrupting. The trap is an error condition which the kernel delivers to the process as a SIGSEGV signal. Note that only 64-bit applications can use ADI and need to be built with ADI-enabled. Values of the ADI version tags, which are in granularity of a cacheline (64 bytes), can be viewed or modified. `adi (examine | x) [ / N ] ADDR' The `adi examine' command displays the value of one ADI version tag per cacheline. N is a decimal integer specifying the number in bytes; the default is 1. It specifies how much ADI version information, at the ratio of 1:ADI block size, to display. ADDR is the address in user address space where you want GDB to begin displaying the ADI version tags. Below is an example of displaying ADI versions of variable "shmaddr". (gdb) adi x/100 shmaddr 0xfff800010002c000: 0 0 `adi (assign | a) [ / N ] ADDR = TAG' The `adi assign' command is used to assign new ADI version tag to an address. N is a decimal integer specifying the number in bytes; the default is 1. It specifies how much ADI version information, at the ratio of 1:ADI block size, to modify. ADDR is the address in user address space where you want GDB to begin modifying the ADI version tags. TAG is the new ADI version tag. For example, do the following to modify then verify ADI versions of variable "shmaddr": (gdb) adi a/100 shmaddr = 7 (gdb) adi x/100 shmaddr 0xfff800010002c000: 7 7  File: gdb.info, Node: S12Z, Next: AMD GPU, Prev: Sparc64, Up: Architectures 21.4.9 S12Z ----------- When GDB is debugging the S12Z architecture, it provides the following special command: `maint info bdccsr' This command displays the current value of the microprocessor's BDCCSR register.  File: gdb.info, Node: AMD GPU, Prev: S12Z, Up: Architectures 21.4.10 AMD GPU --------------- GDB supports debugging programs offloaded to AMD GPU devices using the AMD ROCm (https://docs.amd.com/) platform. GDB presents host threads alongside GPU wavefronts, allowing debugging both the host and device parts of the program simultaneously. 21.4.10.1 AMD GPU Architectures ............................... The list of AMD GPU architectures supported by GDB depends on the version of the AMD Debugger API library used. See its documentation (https://docs.amd.com/bundle/ROCDebugger_User_and_API) for more details. 21.4.10.2 AMD GPU Device Driver and AMD ROCm Runtime .................................................... GDB requires a compatible AMD GPU device driver to be installed. A warning message is displayed if either the device driver version or the version of the debug support it implements is unsupported. GDB will continue to function except no AMD GPU debugging will be possible. GDB requires each agent to have compatible firmware installed by the device driver. A warning message is displayed if unsupported firmware is detected. GDB will continue to function except no AMD GPU debugging will be possible on the agent. GDB requires a compatible AMD ROCm runtime to be loaded in order to detect AMD GPU code objects and wavefronts. A warning message is displayed if an unsupported AMD ROCm runtime is detected, or there is an error or restriction that prevents debugging. GDB will continue to function except no AMD GPU debugging will be possible. 21.4.10.3 AMD GPU Wavefronts ............................ An AMD GPU wavefront is represented in GDB as a thread. Note that some AMD GPU architectures may have restrictions on providing information about AMD GPU wavefronts created when GDB is not attached (*note AMD GPU Attaching Restrictions: AMD GPU Attaching Restrictions.). When scheduler-locking is in effect (*note set scheduler-locking::), new wavefronts created by the resumed thread (either CPU thread or GPU wavefront) are held in the halt state. 21.4.10.4 AMD GPU Code Objects .............................. The `info sharedlibrary' command will show the AMD GPU code objects as file or memory URIs, together with the host's shared libraries. For example: (gdb) info sharedlibrary From To Syms Read Shared Object Library 0x1111 0x2222 Yes (*) /lib64/ld-linux-x86-64.so.2 ... 0x3333 0x4444 Yes (*) /opt/rocm-4.5.0/.../libamd_comgr.so 0x5555 0x6666 Yes (*) /lib/x86_64-linux-gnu/libtinfo.so.5 0x7777 0x8888 Yes file:///tmp/a.out#offset=6477&size=10832 0x9999 0xaaaa Yes (*) memory://95557/mem#offset=0x1234&size=100 (*): Shared library is missing debugging information. (gdb) For a `file' URI, the path portion is the file on disk containing the code object. The OFFSET parameter is a 0-based offset in this file, to the start of the code object. If omitted, it defaults to 0. The SIZE parameter is the size of the code object in bytes. If omitted, it defaults to the size of the file. For a `memory' URI, the path portion is the process id of the process owning the memory containing the code object. The OFFSET parameter is the memory address where the code object is found, and the SIZE parameter is its size in bytes. AMD GPU code objects are loaded into each AMD GPU device separately. The `info sharedlibrary' command may therefore show the same code object loaded multiple times. As a consequence, setting a breakpoint in AMD GPU code will result in multiple breakpoint locations if there are multiple AMD GPU devices. 21.4.10.5 AMD GPU Entity Target Identifiers and Convenience Variables ..................................................................... The AMD GPU entities have the following target identifier formats: Thread Target ID The AMD GPU thread target identifier (SYSTAG) string has the following format: AMDGPU Wave AGENT-ID:QUEUE-ID:DISPATCH-ID:WAVE-ID (WORK-GROUP-X,WORK-GROUP-Y,WORK-GROUP-Z)/WORK-GROUP-THREAD-INDEX 21.4.10.6 AMD GPU Signals ......................... For AMD GPU wavefronts, GDB maps target conditions to stop signals in the following way: `SIGILL' Execution of an illegal instruction. `SIGTRAP' Execution of a `S_TRAP' instruction other than: * `S_TRAP 1' which is used by GDB to insert breakpoints. * `S_TRAP 2' which raises `SIGABRT'. `SIGABRT' Execution of a `S_TRAP 2' instruction. `SIGFPE' Execution of a floating point or integer instruction detects a condition that is enabled to raise a signal. The conditions include: * Floating point operation is invalid. * Floating point operation had subnormal input that was rounded to zero. * Floating point operation performed a division by zero. * Floating point operation produced an overflow result. The result was rounded to infinity. * Floating point operation produced an underflow result. A subnormal result was rounded to zero. * Floating point operation produced an inexact result. * Integer operation performed a division by zero. By default, these conditions are not enabled to raise signals. The `set $mode' command can be used to change the AMD GPU wavefront's register that has bits controlling which conditions are enabled to raise signals. The `print $trapsts' command can be used to inspect which conditions have been detected even if they are not enabled to raise a signal. `SIGBUS' Execution of an instruction that accessed global memory using an address that is outside the virtual address range. `SIGSEGV' Execution of an instruction that accessed a global memory page that is either not mapped or accessed with incompatible permissions. If a single instruction raises more than one signal, they will be reported one at a time each time the wavefront is continued. 21.4.10.7 AMD GPU Memory Violation Reporting ............................................ A wavefront can report memory violation events. However, the program location at which they are reported may be after the machine instruction that caused them. This can result in the reported source statement being incorrect. The following commands can be used to control this behavior: `set amdgpu precise-memory MODE' Controls how AMD GPU devices detect memory violations, where MODE can be: `off' The program location may not be immediately after the instruction that caused the memory violation. This is the default. `on' Requests that the program location will be immediately after the instruction that caused a memory violation. Enabling this mode may make the AMD GPU device execution significantly slower as it has to wait for each memory operation to complete before executing the next instruction. The `amdgpu precise-memory' parameter is per-inferior. When an inferior forks or execs, or the user uses the `clone-inferior' command, and an inferior is created as a result, the newly created inferior inherits the parameter value of the original inferior. `show amdgpu precise-memory' Displays the currently requested AMD GPU precise memory setting. 21.4.10.8 AMD GPU Logging ......................... The `set debug amd-dbgapi' command can be used to enable diagnostic messages in the `amd-dbgapi' target. The `show debug amd-dbgapi' command displays the current setting. *Note set debug amd-dbgapi::. The `set debug amd-dbgapi-lib log-level LEVEL' command can be used to enable diagnostic messages from the `amd-dbgapi' library (which GDB uses under the hood). The `show debug amd-dbgapi-lib log-level' command displays the current `amd-dbgapi' library log level. *Note set debug amd-dbgapi-lib::. 21.4.10.9 AMD GPU Restrictions .............................. 1. When in non-stop mode, wavefronts may not hit breakpoints inserted while not stopped, nor see memory updates made while not stopped, until the wavefront is next stopped. Memory updated by non-stopped wavefronts may not be visible until the wavefront is next stopped. 2. The HIP runtime performs deferred code object loading by default. AMD GPU code objects are not loaded until the first kernel is launched. Before then, all breakpoints have to be set as pending breakpoints. If source line positions are used that only correspond to source lines in unloaded code objects, then GDB may not set pending breakpoints, and instead set breakpoints on the next following source line that maps to host code. This can result in unexpected breakpoint hits being reported. When the code object containing the source lines is loaded, the incorrect breakpoints will be removed and replaced by the correct ones. This problem can be avoided by only setting breakpoints in unloaded code objects using symbol or function names. Setting the `HIP_ENABLE_DEFERRED_LOADING' environment variable to `0' can be used to disable deferred code object loading by the HIP runtime. This ensures all code objects will be loaded when the inferior reaches the beginning of the `main' function. 3. If no CPU thread is running, then `Ctrl-C' is not able to stop AMD GPU threads. This can happen for example if you enable `scheduler-locking' after the whole program stopped, and then resume an AMD GPU thread. The only way to unblock the situation is to kill the GDB process. 4. By default, for some architectures, the AMD GPU device driver causes all AMD GPU wavefronts created when GDB is not attached to be unable to report the dispatch associated with the wavefront, or the wavefront's work-group position. The `info threads' command will display this missing information with a `?'. This does not affect wavefronts created while GDB is attached which are always capable of reporting this information. If the `HSA_ENABLE_DEBUG' environment variable is set to `1' when the AMD ROCm runtime is initialized, then this information will be available for all architectures even for wavefronts created when GDB was not attached.  File: gdb.info, Node: Controlling GDB, Next: Extending GDB, Prev: Configurations, Up: Top 22 Controlling GDB ****************** You can alter the way GDB interacts with you by using the `set' command. For commands controlling how GDB displays data, see *Note Print Settings: Print Settings. Other settings are described here. * Menu: * Prompt:: Prompt * Editing:: Command editing * Command History:: Command history * Screen Size:: Screen size * Output Styling:: Output styling * Numbers:: Numbers * ABI:: Configuring the current ABI * Auto-loading:: Automatically loading associated files * Messages/Warnings:: Optional warnings and messages * Debugging Output:: Optional messages about internal happenings * Other Misc Settings:: Other Miscellaneous Settings  File: gdb.info, Node: Prompt, Next: Editing, Up: Controlling GDB 22.1 Prompt =========== GDB indicates its readiness to read a command by printing a string called the "prompt". This string is normally `(gdb)'. You can change the prompt string with the `set prompt' command. For instance, when debugging GDB with GDB, it is useful to change the prompt in one of the GDB sessions so that you can always tell which one you are talking to. _Note:_ `set prompt' does not add a space for you after the prompt you set. This allows you to set a prompt which ends in a space or a prompt that does not. `set prompt NEWPROMPT' Directs GDB to use NEWPROMPT as its prompt string henceforth. `show prompt' Prints a line of the form: `Gdb's prompt is: YOUR-PROMPT' Versions of GDB that ship with Python scripting enabled have prompt extensions. The commands for interacting with these extensions are: `set extended-prompt PROMPT' Set an extended prompt that allows for substitutions. *Note gdb.prompt::, for a list of escape sequences that can be used for substitution. Any escape sequences specified as part of the prompt string are replaced with the corresponding strings each time the prompt is displayed. For example: set extended-prompt Current working directory: \w (gdb) Note that when an extended-prompt is set, it takes control of the PROMPT_HOOK hook. *Note prompt_hook::, for further information. `show extended-prompt' Prints the extended prompt. Any escape sequences specified as part of the prompt string with `set extended-prompt', are replaced with the corresponding strings each time the prompt is displayed.  File: gdb.info, Node: Editing, Next: Command History, Prev: Prompt, Up: Controlling GDB 22.2 Command Editing ==================== GDB reads its input commands via the "Readline" interface. This GNU library provides consistent behavior for programs which provide a command line interface to the user. Advantages are GNU Emacs-style or "vi"-style inline editing of commands, `csh'-like history substitution, and a storage and recall of command history across debugging sessions. You may control the behavior of command line editing in GDB with the command `set'. `set editing' `set editing on' Enable command line editing (enabled by default). `set editing off' Disable command line editing. `show editing' Show whether command line editing is enabled. *Note Command Line Editing::, for more details about the Readline interface. Users unfamiliar with GNU Emacs or `vi' are encouraged to read that chapter. GDB sets the Readline application name to `gdb'. This is useful for conditions in `.inputrc'. GDB defines a bindable Readline command, `operate-and-get-next'. This is bound to `C-o' by default. This command accepts the current line for execution and fetches the next line relative to the current line from the history for editing. Any argument is ignored.  File: gdb.info, Node: Command History, Next: Screen Size, Prev: Editing, Up: Controlling GDB 22.3 Command History ==================== GDB can keep track of the commands you type during your debugging sessions, so that you can be certain of precisely what happened. Use these commands to manage the GDB command history facility. GDB uses the GNU History library, a part of the Readline package, to provide the history facility. *Note Using History Interactively::, for the detailed description of the History library. To issue a command to GDB without affecting certain aspects of the state which is seen by users, prefix it with `server ' (*note Server Prefix::). This means that this command will not affect the command history, nor will it affect GDB's notion of which command to repeat if is pressed on a line by itself. The server prefix does not affect the recording of values into the value history; to print a value without recording it into the value history, use the `output' command instead of the `print' command. Here is the description of GDB commands related to command history. `set history filename [FNAME]' Set the name of the GDB command history file to FNAME. This is the file where GDB reads an initial command history list, and where it writes the command history from this session when it exits. You can access this list through history expansion or through the history command editing characters listed below. This file defaults to the value of the environment variable `GDBHISTFILE', or to `./.gdb_history' (`./_gdb_history' on MS-DOS) if this variable is not set. The `GDBHISTFILE' environment variable is read after processing any GDB initialization files (*note Startup::) and after processing any commands passed using command line options (for example, `-ex'). If the FNAME argument is not given, or if the `GDBHISTFILE' is the empty string then GDB will neither try to load an existing history file, nor will it try to save the history on exit. `set history save' `set history save on' Record command history in a file, whose name may be specified with the `set history filename' command. By default, this option is disabled. The command history will be recorded when GDB exits. If `set history filename' is set to the empty string then history saving is disabled, even when `set history save' is `on'. `set history save off' Don't record the command history into the file specified by `set history filename' when GDB exits. `set history size SIZE' `set history size unlimited' Set the number of commands which GDB keeps in its history list. This defaults to the value of the environment variable `GDBHISTSIZE', or to 256 if this variable is not set. Non-numeric values of `GDBHISTSIZE' are ignored. If SIZE is `unlimited' or if `GDBHISTSIZE' is either a negative number or the empty string, then the number of commands GDB keeps in the history list is unlimited. The `GDBHISTSIZE' environment variable is read after processing any GDB initialization files (*note Startup::) and after processing any commands passed using command line options (for example, `-ex'). `set history remove-duplicates COUNT' `set history remove-duplicates unlimited' Control the removal of duplicate history entries in the command history list. If COUNT is non-zero, GDB will look back at the last COUNT history entries and remove the first entry that is a duplicate of the current entry being added to the command history list. If COUNT is `unlimited' then this lookbehind is unbounded. If COUNT is 0, then removal of duplicate history entries is disabled. Only history entries added during the current session are considered for removal. This option is set to 0 by default. History expansion assigns special meaning to the character `!'. *Note Event Designators::, for more details. Since `!' is also the logical not operator in C, history expansion is off by default. If you decide to enable history expansion with the `set history expansion on' command, you may sometimes need to follow `!' (when it is used as logical not, in an expression) with a space or a tab to prevent it from being expanded. The readline history facilities do not attempt substitution on the strings `!=' and `!(', even when history expansion is enabled. The commands to control history expansion are: `set history expansion on' `set history expansion' Enable history expansion. History expansion is off by default. `set history expansion off' Disable history expansion. `show history' `show history filename' `show history save' `show history size' `show history expansion' These commands display the state of the GDB history parameters. `show history' by itself displays all four states. `show commands' Display the last ten commands in the command history. `show commands N' Print ten commands centered on command number N. `show commands +' Print ten commands just after the commands last printed.  File: gdb.info, Node: Screen Size, Next: Output Styling, Prev: Command History, Up: Controlling GDB 22.4 Screen Size ================ Certain commands to GDB may produce large amounts of information output to the screen. To help you read all of it, GDB pauses and asks you for input at the end of each page of output. Type when you want to see one more page of output, `q' to discard the remaining output, or `c' to continue without paging for the rest of the current command. Also, the screen width setting determines when to wrap lines of output. Depending on what is being printed, GDB tries to break the line at a readable place, rather than simply letting it overflow onto the following line. Normally GDB knows the size of the screen from the terminal driver software. For example, on Unix GDB uses the termcap data base together with the value of the `TERM' environment variable and the `stty rows' and `stty cols' settings. If this is not correct, you can override it with the `set height' and `set width' commands: `set height LPP' `set height unlimited' `show height' `set width CPL' `set width unlimited' `show width' These `set' commands specify a screen height of LPP lines and a screen width of CPL characters. The associated `show' commands display the current settings. If you specify a height of either `unlimited' or zero lines, GDB does not pause during output no matter how long the output is. This is useful if output is to a file or to an editor buffer. Likewise, you can specify `set width unlimited' or `set width 0' to prevent GDB from wrapping its output. `set pagination on' `set pagination off' Turn the output pagination on or off; the default is on. Turning pagination off is the alternative to `set height unlimited'. Note that running GDB with the `--batch' option (*note -batch: Mode Options.) also automatically disables pagination. `show pagination' Show the current pagination mode.  File: gdb.info, Node: Output Styling, Next: Numbers, Prev: Screen Size, Up: Controlling GDB 22.5 Output Styling =================== GDB can style its output on a capable terminal. This is enabled by default on most systems, but disabled by default when in batch mode (*note Mode Options::). Various style settings are available; and styles can also be disabled entirely. `set style enabled `on|off'' Enable or disable all styling. The default is host-dependent, with most hosts defaulting to `on'. If the `NO_COLOR' environment variable is set to a non-empty value, then GDB will change this to `off' at startup. `show style enabled' Show the current state of styling. `set style sources `on|off'' Enable or disable source code styling. This affects whether source code, such as the output of the `list' command, is styled. The default is `on'. Note that source styling only works if styling in general is enabled, and if a source highlighting library is available to GDB. There are two ways that highlighting can be done. First, if GDB was linked with the GNU Source Highlight library, then it is used. Otherwise, if GDB was configured with Python scripting support, and if the Python Pygments package is available, then it will be used. `show style sources' Show the current state of source code styling. `set style tui-current-position `on|off'' Enable or disable styling of the source and assembly code highlighted by the TUI's current position indicator. The default is `off'. *Note GDB Text User Interface: TUI. `show style tui-current-position' Show whether the source and assembly code highlighted by the TUI's current position indicator is styled. `set style disassembler enabled `on|off'' Enable or disable disassembler styling. This affects whether disassembler output, such as the output of the `disassemble' command, is styled. Disassembler styling only works if styling in general is enabled (with `set style enabled on'), and if a source highlighting library is available to GDB. The two source highlighting libraries that GDB could use to style disassembler output are; GDB's builtin disassembler, or the Python Pygments package. GDB's first choice will be to use the builtin disassembler for styling, this usually provides better results, being able to style different types of instruction operands differently. However, the builtin disassembler is not able to style all architectures. For architectures that the builtin disassembler is unable to style, GDB will fall back to use the Python Pygments package where possible. In order to use the Python Pygments package, GDB must be built with Python support, and the Pygments package must be installed. If neither of these options are available then GDB will produce unstyled disassembler output, even when this setting is `on'. To discover if the current architecture supports styling using the builtin disassembler library see *Note `maint show libopcodes-styling enabled': maint_libopcodes_styling. `show style disassembler enabled' Show the current state of disassembler styling. Subcommands of `set style' control specific forms of styling. These subcommands all follow the same pattern: each style-able object can be styled with a foreground color, a background color, and an intensity. For example, the style of file names can be controlled using the `set style filename' group of commands: `set style filename background COLOR' Set the background to COLOR. Valid colors are `none' (meaning the terminal's default color), `black', `red', `green', `yellow', `blue', `magenta', `cyan', and`white'. `set style filename foreground COLOR' Set the foreground to COLOR. Valid colors are `none' (meaning the terminal's default color), `black', `red', `green', `yellow', `blue', `magenta', `cyan', and`white'. `set style filename intensity VALUE' Set the intensity to VALUE. Valid intensities are `normal' (the default), `bold', and `dim'. The `show style' command and its subcommands are styling a style name in their output using its own style. So, use `show style' to see the complete list of styles, their characteristics and the visual aspect of each style. The style-able objects are: `filename' Control the styling of file names and URLs. By default, this style's foreground color is green. `function' Control the styling of function names. These are managed with the `set style function' family of commands. By default, this style's foreground color is yellow. This style is also used for symbol names in styled disassembler output if GDB is using its builtin disassembler library for styling (*note `set style disassembler enabled': style_disassembler_enabled.). `variable' Control the styling of variable names. These are managed with the `set style variable' family of commands. By default, this style's foreground color is cyan. `address' Control the styling of addresses. These are managed with the `set style address' family of commands. By default, this style's foreground color is blue. This style is also used for addresses in styled disassembler output if GDB is using its builtin disassembler library for styling (*note `set style disassembler enabled': style_disassembler_enabled.). `version' Control the styling of GDB's version number text. By default, this style's foreground color is magenta and it has bold intensity. The version number is displayed in two places, the output of `show version', and when GDB starts up. In order to control how GDB styles the version number at startup, add the `set style version' family of commands to the early initialization command file (*note Initialization Files::). `title' Control the styling of titles. These are managed with the `set style title' family of commands. By default, this style's intensity is bold. Commands are using the title style to improve the readability of large output. For example, the commands `apropos' and `help' are using the title style for the command names. `highlight' Control the styling of highlightings. These are managed with the `set style highlight' family of commands. By default, this style's foreground color is red. Commands are using the highlight style to draw the user attention to some specific parts of their output. For example, the command `apropos -v REGEXP' uses the highlight style to mark the documentation parts matching REGEXP. `metadata' Control the styling of data annotations added by GDB to data it displays. By default, this style's intensity is dim. Metadata annotations include the `repeats N times' annotation for suppressed display of repeated array elements (*note Print Settings::), `' and `' annotations for errors and `' annotations for optimized-out values in displaying stack frame information in backtraces (*note Backtrace::), etc. `tui-border' Control the styling of the TUI border. Note that, unlike other styling options, only the color of the border can be controlled via `set style'. This was done for compatibility reasons, as TUI controls to set the border's intensity predated the addition of general styling to GDB. *Note TUI Configuration::. `tui-active-border' Control the styling of the active TUI border; that is, the TUI window that has the focus. `disassembler comment' Control the styling of comments in the disassembler output. These are managed with the `set style disassembler comment' family of commands. This style is only used when GDB is styling using its builtin disassembler library (*note `set style disassembler enabled': style_disassembler_enabled.). By default, this style's intensity is dim, and its foreground color is white. `disassembler immediate' Control the styling of numeric operands in the disassembler output. These are managed with the `set style disassembler immediate' family of commands. This style is not used for instruction operands that represent addresses, in that case the `disassembler address' style is used. This style is only used when GDB is styling using its builtin disassembler library. By default, this style's foreground color is blue. `disassembler address' Control the styling of address operands in the disassembler output. This is an alias for the `address' style. `disassembler symbol' Control the styling of symbol names in the disassembler output. This is an alias for the `function' style. `disassembler mnemonic' Control the styling of instruction mnemonics in the disassembler output. These are managed with the `set style disassembler mnemonic' family of commands. This style is also used for assembler directives, e.g. `.byte', `.word', etc. This style is only used when GDB is styling using its builtin disassembler library. By default, this style's foreground color is green. `disassembler register' Control the styling of register operands in the disassembler output. These are managed with the `set style disassembler register' family of commands. This style is only used when GDB is styling using its builtin disassembler library. By default, this style's foreground color is red.  File: gdb.info, Node: Numbers, Next: ABI, Prev: Output Styling, Up: Controlling GDB 22.6 Numbers ============ You can always enter numbers in octal, decimal, or hexadecimal in GDB by the usual conventions: octal numbers begin with `0', decimal numbers end with `.', and hexadecimal numbers begin with `0x'. Numbers that neither begin with `0' or `0x', nor end with a `.' are, by default, entered in base 10; likewise, the default display for numbers--when no particular format is specified--is base 10. You can change the default base for both input and output with the commands described below. `set input-radix BASE' Set the default base for numeric input. Supported choices for BASE are decimal 8, 10, or 16. The base must itself be specified either unambiguously or using the current input radix; for example, any of set input-radix 012 set input-radix 10. set input-radix 0xa sets the input base to decimal. On the other hand, `set input-radix 10' leaves the input radix unchanged, no matter what it was, since `10', being without any leading or trailing signs of its base, is interpreted in the current radix. Thus, if the current radix is 16, `10' is interpreted in hex, i.e. as 16 decimal, which doesn't change the radix. `set output-radix BASE' Set the default base for numeric display. Supported choices for BASE are decimal 8, 10, or 16. The base must itself be specified either unambiguously or using the current input radix. `show input-radix' Display the current default base for numeric input. `show output-radix' Display the current default base for numeric display. `set radix [BASE]' `show radix' These commands set and show the default base for both input and output of numbers. `set radix' sets the radix of input and output to the same base; without an argument, it resets the radix back to its default value of 10.  File: gdb.info, Node: ABI, Next: Auto-loading, Prev: Numbers, Up: Controlling GDB 22.7 Configuring the Current ABI ================================ GDB can determine the "ABI" (Application Binary Interface) of your application automatically. However, sometimes you need to override its conclusions. Use these commands to manage GDB's view of the current ABI. One GDB configuration can debug binaries for multiple operating system targets, either via remote debugging or native emulation. GDB will autodetect the "OS ABI" (Operating System ABI) in use, but you can override its conclusion using the `set osabi' command. One example where this is useful is in debugging of binaries which use an alternate C library (e.g. UCLIBC for GNU/Linux) which does not have the same identifying marks that the standard C library for your platform provides. When GDB is debugging the AArch64 architecture, it provides a "Newlib" OS ABI. This is useful for handling `setjmp' and `longjmp' when debugging binaries that use the NEWLIB C library. The "Newlib" OS ABI can be selected by `set osabi Newlib'. `show osabi' Show the OS ABI currently in use. `set osabi' With no argument, show the list of registered available OS ABI's. `set osabi ABI' Set the current OS ABI to ABI. Generally, the way that an argument of type `float' is passed to a function depends on whether the function is prototyped. For a prototyped (i.e. ANSI/ISO style) function, `float' arguments are passed unchanged, according to the architecture's convention for `float'. For unprototyped (i.e. K&R style) functions, `float' arguments are first promoted to type `double' and then passed. Unfortunately, some forms of debug information do not reliably indicate whether a function is prototyped. If GDB calls a function that is not marked as prototyped, it consults `set coerce-float-to-double'. `set coerce-float-to-double' `set coerce-float-to-double on' Arguments of type `float' will be promoted to `double' when passed to an unprototyped function. This is the default setting. `set coerce-float-to-double off' Arguments of type `float' will be passed directly to unprototyped functions. `show coerce-float-to-double' Show the current setting of promoting `float' to `double'. GDB needs to know the ABI used for your program's C++ objects. The correct C++ ABI depends on which C++ compiler was used to build your application. GDB only fully supports programs with a single C++ ABI; if your program contains code using multiple C++ ABI's or if GDB can not identify your program's ABI correctly, you can tell GDB which ABI to use. Currently supported ABI's include "gnu-v2", for `g++' versions before 3.0, "gnu-v3", for `g++' versions 3.0 and later, and "hpaCC" for the HP ANSI C++ compiler. Other C++ compilers may use the "gnu-v2" or "gnu-v3" ABI's as well. The default setting is "auto". `show cp-abi' Show the C++ ABI currently in use. `set cp-abi' With no argument, show the list of supported C++ ABI's. `set cp-abi ABI' `set cp-abi auto' Set the current C++ ABI to ABI, or return to automatic detection.  File: gdb.info, Node: Auto-loading, Next: Messages/Warnings, Prev: ABI, Up: Controlling GDB 22.8 Automatically loading associated files =========================================== GDB sometimes reads files with commands and settings automatically, without being explicitly told so by the user. We call this feature "auto-loading". While auto-loading is useful for automatically adapting GDB to the needs of your project, it can sometimes produce unexpected results or introduce security risks (e.g., if the file comes from untrusted sources). There are various kinds of files GDB can automatically load. In addition to these files, GDB supports auto-loading code written in various extension languages. *Note Auto-loading extensions::. Note that loading of these associated files (including the local `.gdbinit' file) requires accordingly configured `auto-load safe-path' (*note Auto-loading safe path::). For these reasons, GDB includes commands and options to let you control when to auto-load files and which files should be auto-loaded. `set auto-load off' Globally disable loading of all auto-loaded files. You may want to use this command with the `-iex' option (*note Option -init-eval-command::) such as: $ gdb -iex "set auto-load off" untrusted-executable corefile Be aware that system init file (*note System-wide configuration::) and init files from your home directory (*note Home Directory Init File::) still get read (as they come from generally trusted directories). To prevent GDB from auto-loading even those init files, use the `-nx' option (*note Mode Options::), in addition to `set auto-load no'. `show auto-load' Show whether auto-loading of each specific `auto-load' file(s) is enabled or disabled. (gdb) show auto-load gdb-scripts: Auto-loading of canned sequences of commands scripts is on. libthread-db: Auto-loading of inferior specific libthread_db is on. local-gdbinit: Auto-loading of .gdbinit script from current directory is on. python-scripts: Auto-loading of Python scripts is on. safe-path: List of directories from which it is safe to auto-load files is $debugdir:$datadir/auto-load. scripts-directory: List of directories from which to load auto-loaded scripts is $debugdir:$datadir/auto-load. `info auto-load' Print whether each specific `auto-load' file(s) have been auto-loaded or not. (gdb) info auto-load gdb-scripts: Loaded Script Yes /home/user/gdb/gdb-gdb.gdb libthread-db: No auto-loaded libthread-db. local-gdbinit: Local .gdbinit file "/home/user/gdb/.gdbinit" has been loaded. python-scripts: Loaded Script Yes /home/user/gdb/gdb-gdb.py These are GDB control commands for the auto-loading: *Note set auto-load off::. Disable auto-loading globally. *Note show auto-load::. Show setting of all kinds of files. *Note info auto-load::. Show state of all kinds of files. *Note set auto-load gdb-scripts::. Control for GDB command scripts. *Note show auto-load gdb-scripts::. Show setting of GDB command scripts. *Note info auto-load gdb-scripts::. Show state of GDB command scripts. *Note set auto-load Control for GDB Python scripts. python-scripts::. *Note show auto-load Show setting of GDB Python scripts. python-scripts::. *Note info auto-load Show state of GDB Python scripts. python-scripts::. *Note set auto-load guile-scripts::. Control for GDB Guile scripts. *Note show auto-load Show setting of GDB Guile scripts. guile-scripts::. *Note info auto-load Show state of GDB Guile scripts. guile-scripts::. *Note set auto-load Control for GDB auto-loaded scripts scripts-directory::. location. *Note show auto-load Show GDB auto-loaded scripts scripts-directory::. location. *Note Add directory for auto-loaded add-auto-load-scripts-directory::. scripts location list. *Note set auto-load local-gdbinit::. Control for init file in the current directory. *Note show auto-load Show setting of init file in the local-gdbinit::. current directory. *Note info auto-load Show state of init file in the local-gdbinit::. current directory. *Note set auto-load libthread-db::. Control for thread debugging library. *Note show auto-load libthread-db::. Show setting of thread debugging library. *Note info auto-load libthread-db::. Show state of thread debugging library. *Note set auto-load safe-path::. Control directories trusted for automatic loading. *Note show auto-load safe-path::. Show directories trusted for automatic loading. *Note add-auto-load-safe-path::. Add directory trusted for automatic loading. * Menu: * Init File in the Current Directory:: `set/show/info auto-load local-gdbinit' * libthread_db.so.1 file:: `set/show/info auto-load libthread-db' * Auto-loading safe path:: `set/show/info auto-load safe-path' * Auto-loading verbose mode:: `set/show debug auto-load'  File: gdb.info, Node: Init File in the Current Directory, Next: libthread_db.so.1 file, Up: Auto-loading 22.8.1 Automatically loading init file in the current directory --------------------------------------------------------------- By default, GDB reads and executes the canned sequences of commands from init file (if any) in the current working directory, see *Note Init File in the Current Directory during Startup::. Note that loading of this local `.gdbinit' file also requires accordingly configured `auto-load safe-path' (*note Auto-loading safe path::). `set auto-load local-gdbinit [on|off]' Enable or disable the auto-loading of canned sequences of commands (*note Sequences::) found in init file in the current directory. `show auto-load local-gdbinit' Show whether auto-loading of canned sequences of commands from init file in the current directory is enabled or disabled. `info auto-load local-gdbinit' Print whether canned sequences of commands from init file in the current directory have been auto-loaded.  File: gdb.info, Node: libthread_db.so.1 file, Next: Auto-loading safe path, Prev: Init File in the Current Directory, Up: Auto-loading 22.8.2 Automatically loading thread debugging library ----------------------------------------------------- This feature is currently present only on GNU/Linux native hosts. GDB reads in some cases thread debugging library from places specific to the inferior (*note set libthread-db-search-path::). The special `libthread-db-search-path' entry `$sdir' is processed without checking this `set auto-load libthread-db' switch as system libraries have to be trusted in general. In all other cases of `libthread-db-search-path' entries GDB checks first if `set auto-load libthread-db' is enabled before trying to open such thread debugging library. Note that loading of this debugging library also requires accordingly configured `auto-load safe-path' (*note Auto-loading safe path::). `set auto-load libthread-db [on|off]' Enable or disable the auto-loading of inferior specific thread debugging library. `show auto-load libthread-db' Show whether auto-loading of inferior specific thread debugging library is enabled or disabled. `info auto-load libthread-db' Print the list of all loaded inferior specific thread debugging libraries and for each such library print list of inferior PIDs using it.  File: gdb.info, Node: Auto-loading safe path, Next: Auto-loading verbose mode, Prev: libthread_db.so.1 file, Up: Auto-loading 22.8.3 Security restriction for auto-loading -------------------------------------------- As the files of inferior can come from untrusted source (such as submitted by an application user) GDB does not always load any files automatically. GDB provides the `set auto-load safe-path' setting to list directories trusted for loading files not explicitly requested by user. Each directory can also be a shell wildcard pattern. If the path is not set properly you will see a warning and the file will not get loaded: $ ./gdb -q ./gdb Reading symbols from /home/user/gdb/gdb... warning: File "/home/user/gdb/gdb-gdb.gdb" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load". warning: File "/home/user/gdb/gdb-gdb.py" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load". To instruct GDB to go ahead and use the init files anyway, invoke GDB like this: $ gdb -q -iex "set auto-load safe-path /home/user/gdb" ./gdb The list of trusted directories is controlled by the following commands: `set auto-load safe-path [DIRECTORIES]' Set the list of directories (and their subdirectories) trusted for automatic loading and execution of scripts. You can also enter a specific trusted file. Each directory can also be a shell wildcard pattern; wildcards do not match directory separator - see `FNM_PATHNAME' for system function `fnmatch' (*note fnmatch: (libc)Wildcard Matching.). If you omit DIRECTORIES, `auto-load safe-path' will be reset to its default value as specified during GDB compilation. The list of directories uses path separator (`:' on GNU and Unix systems, `;' on MS-Windows and MS-DOS) to separate directories, similarly to the `PATH' environment variable. `show auto-load safe-path' Show the list of directories trusted for automatic loading and execution of scripts. `add-auto-load-safe-path' Add an entry (or list of entries) to the list of directories trusted for automatic loading and execution of scripts. Multiple entries may be delimited by the host platform path separator in use. This variable defaults to what `--with-auto-load-dir' has been configured to (*note with-auto-load-dir::). `$debugdir' and `$datadir' substitution applies the same as for *Note set auto-load scripts-directory::. The default `set auto-load safe-path' value can be also overridden by GDB configuration option `--with-auto-load-safe-path'. Setting this variable to `/' disables this security protection, corresponding GDB configuration option is `--without-auto-load-safe-path'. This variable is supposed to be set to the system directories writable by the system superuser only. Users can add their source directories in init files in their home directories (*note Home Directory Init File::). See also deprecated init file in the current directory (*note Init File in the Current Directory during Startup::). To force GDB to load the files it declined to load in the previous example, you could use one of the following ways: `~/.gdbinit': `add-auto-load-safe-path ~/src/gdb' Specify this trusted directory (or a file) as additional component of the list. You have to specify also any existing directories displayed by by `show auto-load safe-path' (such as `/usr:/bin' in this example). `gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" ...' Specify this directory as in the previous case but just for a single GDB session. `gdb -iex "set auto-load safe-path /" ...' Disable auto-loading safety for a single GDB session. This assumes all the files you debug during this GDB session will come from trusted sources. `./configure --without-auto-load-safe-path' During compilation of GDB you may disable any auto-loading safety. This assumes all the files you will ever debug with this GDB come from trusted sources. On the other hand you can also explicitly forbid automatic files loading which also suppresses any such warning messages: `gdb -iex "set auto-load no" ...' You can use GDB command-line option for a single GDB session. `~/.gdbinit': `set auto-load no' Disable auto-loading globally for the user (*note Home Directory Init File::). While it is improbable, you could also use system init file instead (*note System-wide configuration::). This setting applies to the file names as entered by user. If no entry matches GDB tries as a last resort to also resolve all the file names into their canonical form (typically resolving symbolic links) and compare the entries again. GDB already canonicalizes most of the filenames on its own before starting the comparison so a canonical form of directories is recommended to be entered.  File: gdb.info, Node: Auto-loading verbose mode, Prev: Auto-loading safe path, Up: Auto-loading 22.8.4 Displaying files tried for auto-load ------------------------------------------- For better visibility of all the file locations where you can place scripts to be auto-loaded with inferior -- or to protect yourself against accidental execution of untrusted scripts -- GDB provides a feature for printing all the files attempted to be loaded. Both existing and non-existing files may be printed. For example the list of directories from which it is safe to auto-load files (*note Auto-loading safe path::) applies also to canonicalized filenames which may not be too obvious while setting it up. (gdb) set debug auto-load on (gdb) file ~/src/t/true auto-load: Loading canned sequences of commands script "/tmp/true-gdb.gdb" for objfile "/tmp/true". auto-load: Updating directories of "/usr:/opt". auto-load: Using directory "/usr". auto-load: Using directory "/opt". warning: File "/tmp/true-gdb.gdb" auto-loading has been declined by your `auto-load safe-path' set to "/usr:/opt". `set debug auto-load [on|off]' Set whether to print the filenames attempted to be auto-loaded. `show debug auto-load' Show whether printing of the filenames attempted to be auto-loaded is turned on or off.  File: gdb.info, Node: Messages/Warnings, Next: Debugging Output, Prev: Auto-loading, Up: Controlling GDB 22.9 Optional Warnings and Messages =================================== By default, GDB is silent about its inner workings. If you are running on a slow machine, you may want to use the `set verbose' command. This makes GDB tell you when it does a lengthy internal operation, so you will not think it has crashed. Currently, the messages controlled by `set verbose' are those which announce that the symbol table for a source file is being read; see `symbol-file' in *Note Commands to Specify Files: Files. `set verbose on' Enables GDB output of certain informational messages. `set verbose off' Disables GDB output of certain informational messages. `show verbose' Displays whether `set verbose' is on or off. By default, if GDB encounters bugs in the symbol table of an object file, it is silent; but if you are debugging a compiler, you may find this information useful (*note Errors Reading Symbol Files: Symbol Errors.). `set complaints LIMIT' Permits GDB to output LIMIT complaints about each type of unusual symbols before becoming silent about the problem. Set LIMIT to zero to suppress all complaints; set it to a large number to prevent complaints from being suppressed. `show complaints' Displays how many symbol complaints GDB is permitted to produce. By default, GDB is cautious, and asks what sometimes seems to be a lot of stupid questions to confirm certain commands. For example, if you try to run a program which is already running: (gdb) run The program being debugged has been started already. Start it from the beginning? (y or n) If you are willing to unflinchingly face the consequences of your own commands, you can disable this "feature": `set confirm off' Disables confirmation requests. Note that running GDB with the `--batch' option (*note -batch: Mode Options.) also automatically disables confirmation requests. `set confirm on' Enables confirmation requests (the default). `show confirm' Displays state of confirmation requests. If you need to debug user-defined commands or sourced files you may find it useful to enable "command tracing". In this mode each command will be printed as it is executed, prefixed with one or more `+' symbols, the quantity denoting the call depth of each command. `set trace-commands on' Enable command tracing. `set trace-commands off' Disable command tracing. `show trace-commands' Display the current state of command tracing.  File: gdb.info, Node: Debugging Output, Next: Other Misc Settings, Prev: Messages/Warnings, Up: Controlling GDB 22.10 Optional Messages about Internal Happenings ================================================= GDB has commands that enable optional debugging messages from various GDB subsystems; normally these commands are of interest to GDB maintainers, or when reporting a bug. This section documents those commands. `set exec-done-display' Turns on or off the notification of asynchronous commands' completion. When on, GDB will print a message when an asynchronous command finishes its execution. The default is off. `show exec-done-display' Displays the current setting of asynchronous command completion notification. `set debug aarch64' Turns on or off display of debugging messages related to ARM AArch64. The default is off. `show debug aarch64' Displays the current state of displaying debugging messages related to ARM AArch64. `set debug arch' Turns on or off display of gdbarch debugging info. The default is off `show debug arch' Displays the current state of displaying gdbarch debugging info. `set debug aix-thread' Display debugging messages about inner workings of the AIX thread module. `show debug aix-thread' Show the current state of AIX thread debugging info display. `set debug amd-dbgapi-lib' `show debug amd-dbgapi-lib' The `set debug amd-dbgapi-lib log-level LEVEL' command can be used to enable diagnostic messages from the `amd-dbgapi' library, where LEVEL can be: `off' no logging is enabled `error' fatal errors are reported `warning' fatal errors and warnings are reported `info' fatal errors, warnings, and info messages are reported `verbose' all messages are reported The `show debug amd-dbgapi-lib log-level' command displays the current amd-dbgapi library log level. `set debug amd-dbgapi' `show debug amd-dbgapi' The `set debug amd-dbgapi' command can be used to enable diagnostic messages in the `amd-dbgapi' target. The `show debug amd-dbgapi' command displays the current setting. *Note set debug amd-dbgapi::. `set debug check-physname' Check the results of the "physname" computation. When reading DWARF debugging information for C++, GDB attempts to compute each entity's name. GDB can do this computation in two different ways, depending on exactly what information is present. When enabled, this setting causes GDB to compute the names both ways and display any discrepancies. `show debug check-physname' Show the current state of "physname" checking. `set debug coff-pe-read' Control display of debugging messages related to reading of COFF/PE exported symbols. The default is off. `show debug coff-pe-read' Displays the current state of displaying debugging messages related to reading of COFF/PE exported symbols. `set debug dwarf-die' Dump DWARF DIEs after they are read in. The value is the number of nesting levels to print. A value of zero turns off the display. `show debug dwarf-die' Show the current state of DWARF DIE debugging. `set debug dwarf-line' Turns on or off display of debugging messages related to reading DWARF line tables. The default is 0 (off). A value of 1 provides basic information. A value greater than 1 provides more verbose information. `show debug dwarf-line' Show the current state of DWARF line table debugging. `set debug dwarf-read' Turns on or off display of debugging messages related to reading DWARF debug info. The default is 0 (off). A value of 1 provides basic information. A value greater than 1 provides more verbose information. `show debug dwarf-read' Show the current state of DWARF reader debugging. `set debug displaced' Turns on or off display of GDB debugging info for the displaced stepping support. The default is off. `show debug displaced' Displays the current state of displaying GDB debugging info related to displaced stepping. `set debug event' Turns on or off display of GDB event debugging info. The default is off. `show debug event' Displays the current state of displaying GDB event debugging info. `set debug event-loop' Controls output of debugging info about the event loop. The possible values are `off', `all' (shows all debugging info) and `all-except-ui' (shows all debugging info except those about UI-related events). `show debug event-loop' Shows the current state of displaying debugging info about the event loop. `set debug expression' Turns on or off display of debugging info about GDB expression parsing. The default is off. `show debug expression' Displays the current state of displaying debugging info about GDB expression parsing. `set debug fbsd-lwp' Turns on or off debugging messages from the FreeBSD LWP debug support. `show debug fbsd-lwp' Show the current state of FreeBSD LWP debugging messages. `set debug fbsd-nat' Turns on or off debugging messages from the FreeBSD native target. `show debug fbsd-nat' Show the current state of FreeBSD native target debugging messages. `set debug fortran-array-slicing' Turns on or off display of GDB Fortran array slicing debugging info. The default is off. `show debug fortran-array-slicing' Displays the current state of displaying GDB Fortran array slicing debugging info. `set debug frame' Turns on or off display of GDB frame debugging info. The default is off. `show debug frame' Displays the current state of displaying GDB frame debugging info. `set debug gnu-nat' Turn on or off debugging messages from the GNU/Hurd debug support. `show debug gnu-nat' Show the current state of GNU/Hurd debugging messages. `set debug infrun' Turns on or off display of GDB debugging info for running the inferior. The default is off. `infrun.c' contains GDB's runtime state machine used for implementing operations such as single-stepping the inferior. `show debug infrun' Displays the current state of GDB inferior debugging. `set debug infcall' Turns on or off display of debugging info related to inferior function calls made by GDB. `show debug infcall' Displays the current state of GDB inferior function call debugging. `set debug jit' Turn on or off debugging messages from JIT debug support. `show debug jit' Displays the current state of GDB JIT debugging. `set debug linux-nat [on|off]' Turn on or off debugging messages from the Linux native target debug support. `show debug linux-nat' Show the current state of Linux native target debugging messages. `set debug linux-namespaces' Turn on or off debugging messages from the Linux namespaces debug support. `show debug linux-namespaces' Show the current state of Linux namespaces debugging messages. `set debug mach-o' Control display of debugging messages related to Mach-O symbols processing. The default is off. `show debug mach-o' Displays the current state of displaying debugging messages related to reading of COFF/PE exported symbols. `set debug notification' Turn on or off debugging messages about remote async notification. The default is off. `show debug notification' Displays the current state of remote async notification debugging messages. `set debug observer' Turns on or off display of GDB observer debugging. This includes info such as the notification of observable events. `show debug observer' Displays the current state of observer debugging. `set debug overload' Turns on or off display of GDB C++ overload debugging info. This includes info such as ranking of functions, etc. The default is off. `show debug overload' Displays the current state of displaying GDB C++ overload debugging info. `set debug parser' Turns on or off the display of expression parser debugging output. Internally, this sets the `yydebug' variable in the expression parser. *Note Tracing Your Parser: (bison)Tracing, for details. The default is off. `show debug parser' Show the current state of expression parser debugging. `set debug remote' Turns on or off display of reports on all packets sent back and forth across the serial line to the remote machine. The info is printed on the GDB standard output stream. The default is off. `show debug remote' Displays the state of display of remote packets. `set debug remote-packet-max-chars' Sets the maximum number of characters to display for each remote packet when `set debug remote' is on. This is useful to prevent GDB from displaying lengthy remote packets and polluting the console. The default value is `512', which means GDB will truncate each remote packet after 512 bytes. Setting this option to `unlimited' will disable truncation and will output the full length of the remote packets. `show debug remote-packet-max-chars' Displays the number of bytes to output for remote packet debugging. `set debug separate-debug-file' Turns on or off display of debug output about separate debug file search. `show debug separate-debug-file' Displays the state of separate debug file search debug output. `set debug serial' Turns on or off display of GDB serial debugging info. The default is off. `show debug serial' Displays the current state of displaying GDB serial debugging info. `set debug solib' Turns on or off display of debugging messages related to shared libraries. The default is off. `show debug solib' Show the current state of solib debugging messages. `set debug symbol-lookup' Turns on or off display of debugging messages related to symbol lookup. The default is 0 (off). A value of 1 provides basic information. A value greater than 1 provides more verbose information. `show debug symbol-lookup' Show the current state of symbol lookup debugging messages. `set debug symfile' Turns on or off display of debugging messages related to symbol file functions. The default is off. *Note Files::. `show debug symfile' Show the current state of symbol file debugging messages. `set debug symtab-create' Turns on or off display of debugging messages related to symbol table creation. The default is 0 (off). A value of 1 provides basic information. A value greater than 1 provides more verbose information. `show debug symtab-create' Show the current state of symbol table creation debugging. `set debug target' Turns on or off display of GDB target debugging info. This info includes what is going on at the target level of GDB, as it happens. The default is 0. Set it to 1 to track events, and to 2 to also track the value of large memory transfers. `show debug target' Displays the current state of displaying GDB target debugging info. `set debug timestamp' Turns on or off display of timestamps with GDB debugging info. When enabled, seconds and microseconds are displayed before each debugging message. `show debug timestamp' Displays the current state of displaying timestamps with GDB debugging info. `set debug varobj' Turns on or off display of GDB variable object debugging info. The default is off. `show debug varobj' Displays the current state of displaying GDB variable object debugging info. `set debug xml' Turn on or off debugging messages for built-in XML parsers. `show debug xml' Displays the current state of XML debugging messages. `set debug breakpoints' Turns on or off display of GDB debugging info for breakpoint insertion and removal. The default is off. `show debug breakpoints' Displays the current state of displaying GDB debugging info for breakpoint insertion and removal.  File: gdb.info, Node: Other Misc Settings, Prev: Debugging Output, Up: Controlling GDB 22.11 Other Miscellaneous Settings ================================== `set interactive-mode' If `on', forces GDB to assume that GDB was started in a terminal. In practice, this means that GDB should wait for the user to answer queries generated by commands entered at the command prompt. If `off', forces GDB to operate in the opposite mode, and it uses the default answers to all queries. If `auto' (the default), GDB tries to determine whether its standard input is a terminal, and works in interactive-mode if it is, non-interactively otherwise. In the vast majority of cases, the debugger should be able to guess correctly which mode should be used. But this setting can be useful in certain specific cases, such as running a MinGW GDB inside a cygwin window. `show interactive-mode' Displays whether the debugger is operating in interactive mode or not. `set suppress-cli-notifications' If `on', command-line-interface (CLI) notifications that are printed by GDB are suppressed. If `off', the notifications are printed as usual. The default value is `off'. CLI notifications occur when you change the selected context or when the program being debugged stops, as detailed below. _User-selected context changes:_ When you change the selected context (i.e. the current inferior, thread and/or the frame), GDB prints information about the new context. For example, the default behavior is below: (gdb) inferior 1 [Switching to inferior 1 [process 634] (/tmp/test)] [Switching to thread 1 (process 634)] #0 main () at test.c:3 3 return 0; (gdb) When the notifications are suppressed, the new context is not printed: (gdb) set suppress-cli-notifications on (gdb) inferior 1 (gdb) _The program being debugged stops:_ When the program you are debugging stops (e.g. because of hitting a breakpoint, completing source-stepping, an interrupt, etc.), GDB prints information about the stop event. For example, below is a breakpoint hit: (gdb) break test.c:3 Breakpoint 2 at 0x555555555155: file test.c, line 3. (gdb) continue Continuing. Breakpoint 2, main () at test.c:3 3 return 0; (gdb) When the notifications are suppressed, the output becomes: (gdb) break test.c:3 Breakpoint 2 at 0x555555555155: file test.c, line 3. (gdb) set suppress-cli-notifications on (gdb) continue Continuing. (gdb) Suppressing CLI notifications may be useful in scripts to obtain a reduced output from a list of commands. `show suppress-cli-notifications' Displays whether printing CLI notifications is suppressed or not.  File: gdb.info, Node: Extending GDB, Next: Interpreters, Prev: Controlling GDB, Up: Top 23 Extending GDB **************** GDB provides several mechanisms for extension. GDB also provides the ability to automatically load extensions when it reads a file for debugging. This allows the user to automatically customize GDB for the program being debugged. To facilitate the use of extension languages, GDB is capable of evaluating the contents of a file. When doing so, GDB can recognize which extension language is being used by looking at the filename extension. Files with an unrecognized filename extension are always treated as a GDB Command Files. *Note Command files: Command Files. You can control how GDB evaluates these files with the following setting: `set script-extension off' All scripts are always evaluated as GDB Command Files. `set script-extension soft' The debugger determines the scripting language based on filename extension. If this scripting language is supported, GDB evaluates the script using that language. Otherwise, it evaluates the file as a GDB Command File. `set script-extension strict' The debugger determines the scripting language based on filename extension, and evaluates the script using that language. If the language is not supported, then the evaluation fails. `show script-extension' Display the current value of the `script-extension' option. * Menu: * Sequences:: Canned Sequences of GDB Commands * Aliases:: Command Aliases * Python:: Extending GDB using Python * Guile:: Extending GDB using Guile * Auto-loading extensions:: Automatically loading extensions * Multiple Extension Languages:: Working with multiple extension languages  File: gdb.info, Node: Sequences, Next: Aliases, Up: Extending GDB 23.1 Canned Sequences of Commands ================================= Aside from breakpoint commands (*note Breakpoint Command Lists: Break Commands.), GDB provides two ways to store sequences of commands for execution as a unit: user-defined commands and command files. * Menu: * Define:: How to define your own commands * Hooks:: Hooks for user-defined commands * Command Files:: How to write scripts of commands to be stored in a file * Output:: Commands for controlled output * Auto-loading sequences:: Controlling auto-loaded command files  File: gdb.info, Node: Define, Next: Hooks, Up: Sequences 23.1.1 User-defined Commands ---------------------------- A "user-defined command" is a sequence of GDB commands to which you assign a new name as a command. This is done with the `define' command. User commands may accept an unlimited number of arguments separated by whitespace. Arguments are accessed within the user command via `$arg0...$argN'. A trivial example: define adder print $arg0 + $arg1 + $arg2 end To execute the command use: adder 1 2 3 This defines the command `adder', which prints the sum of its three arguments. Note the arguments are text substitutions, so they may reference variables, use complex expressions, or even perform inferior functions calls. In addition, `$argc' may be used to find out how many arguments have been passed. define adder if $argc == 2 print $arg0 + $arg1 end if $argc == 3 print $arg0 + $arg1 + $arg2 end end Combining with the `eval' command (*note eval::) makes it easier to process a variable number of arguments: define adder set $i = 0 set $sum = 0 while $i < $argc eval "set $sum = $sum + $arg%d", $i set $i = $i + 1 end print $sum end `define COMMANDNAME' Define a command named COMMANDNAME. If there is already a command by that name, you are asked to confirm that you want to redefine it. The argument COMMANDNAME may be a bare command name consisting of letters, numbers, dashes, dots, and underscores. It may also start with any predefined or user-defined prefix command. For example, `define target my-target' creates a user-defined `target my-target' command. The definition of the command is made up of other GDB command lines, which are given following the `define' command. The end of these commands is marked by a line containing `end'. `document COMMANDNAME' Document the user-defined command COMMANDNAME, so that it can be accessed by `help'. The command COMMANDNAME must already be defined. This command reads lines of documentation just as `define' reads the lines of the command definition, ending with `end'. After the `document' command is finished, `help' on command COMMANDNAME displays the documentation you have written. You may use the `document' command again to change the documentation of a command. Redefining the command with `define' does not change the documentation. It is also possible to document user-defined aliases. The alias documentation will then be used by the `help' and `apropos' commands instead of the documentation of the aliased command. Documenting a user-defined alias is particularly useful when defining an alias as a set of nested `with' commands (*note Command aliases default args::). `define-prefix COMMANDNAME' Define or mark the command COMMANDNAME as a user-defined prefix command. Once marked, COMMANDNAME can be used as prefix command by the `define' command. Note that `define-prefix' can be used with a not yet defined COMMANDNAME. In such a case, COMMANDNAME is defined as an empty user-defined command. In case you redefine a command that was marked as a user-defined prefix command, the subcommands of the redefined command are kept (and GDB indicates so to the user). Example: (gdb) define-prefix abc (gdb) define-prefix abc def (gdb) define abc def Type commands for definition of "abc def". End with a line saying just "end". >echo command initial def\n >end (gdb) define abc def ghi Type commands for definition of "abc def ghi". End with a line saying just "end". >echo command ghi\n >end (gdb) define abc def Keeping subcommands of prefix command "def". Redefine command "def"? (y or n) y Type commands for definition of "abc def". End with a line saying just "end". >echo command def\n >end (gdb) abc def ghi command ghi (gdb) abc def command def (gdb) `dont-repeat' Used inside a user-defined command, this tells GDB that this command should not be repeated when the user hits (*note repeat last command: Command Syntax.). `help user-defined' List all user-defined commands and all python commands defined in class COMMAND_USER. The first line of the documentation or docstring is included (if any). `show user' `show user COMMANDNAME' Display the GDB commands used to define COMMANDNAME (but not its documentation). If no COMMANDNAME is given, display the definitions for all user-defined commands. This does not work for user-defined python commands. `show max-user-call-depth' `set max-user-call-depth' The value of `max-user-call-depth' controls how many recursion levels are allowed in user-defined commands before GDB suspects an infinite recursion and aborts the command. This does not apply to user-defined python commands. In addition to the above commands, user-defined commands frequently use control flow commands, described in *Note Command Files::. When user-defined commands are executed, the commands of the definition are not printed. An error in any command stops execution of the user-defined command. If used interactively, commands that would ask for confirmation proceed without asking when used inside a user-defined command. Many GDB commands that normally print messages to say what they are doing omit the messages when used in a user-defined command.  File: gdb.info, Node: Hooks, Next: Command Files, Prev: Define, Up: Sequences 23.1.2 User-defined Command Hooks --------------------------------- You may define "hooks", which are a special kind of user-defined command. Whenever you run the command `foo', if the user-defined command `hook-foo' exists, it is executed (with no arguments) before that command. A hook may also be defined which is run after the command you executed. Whenever you run the command `foo', if the user-defined command `hookpost-foo' exists, it is executed (with no arguments) after that command. Post-execution hooks may exist simultaneously with pre-execution hooks, for the same command. It is valid for a hook to call the command which it hooks. If this occurs, the hook is not re-executed, thereby avoiding infinite recursion. In addition, a pseudo-command, `stop' exists. Defining (`hook-stop') makes the associated commands execute every time execution stops in your program: before breakpoint commands are run, displays are printed, or the stack frame is printed. For example, to ignore `SIGALRM' signals while single-stepping, but treat them normally during normal execution, you could define: define hook-stop handle SIGALRM nopass end define hook-run handle SIGALRM pass end define hook-continue handle SIGALRM pass end As a further example, to hook at the beginning and end of the `echo' command, and to add extra text to the beginning and end of the message, you could define: define hook-echo echo <<<--- end define hookpost-echo echo --->>>\n end (gdb) echo Hello World <<<---Hello World--->>> (gdb) You can define a hook for any single-word command in GDB, but not for command aliases; you should define a hook for the basic command name, e.g. `backtrace' rather than `bt'. You can hook a multi-word command by adding `hook-' or `hookpost-' to the last word of the command, e.g. `define target hook-remote' to add a hook to `target remote'. If an error occurs during the execution of your hook, execution of GDB commands stops and GDB issues a prompt (before the command that you actually typed had a chance to run). If you try to define a hook which does not match any known command, you get a warning from the `define' command.  File: gdb.info, Node: Command Files, Next: Output, Prev: Hooks, Up: Sequences 23.1.3 Command Files -------------------- A command file for GDB is a text file made of lines that are GDB commands. Comments (lines starting with `#') may also be included. An empty line in a command file does nothing; it does not mean to repeat the last command, as it would from the terminal. You can request the execution of a command file with the `source' command. Note that the `source' command is also used to evaluate scripts that are not Command Files. The exact behavior can be configured using the `script-extension' setting. *Note Extending GDB: Extending GDB. `source [-s] [-v] FILENAME' Execute the command file FILENAME. The lines in a command file are generally executed sequentially, unless the order of execution is changed by one of the _flow-control commands_ described below. The commands are not printed as they are executed. An error in any command terminates execution of the command file and control is returned to the console. GDB first searches for FILENAME in the current directory. If the file is not found there, and FILENAME does not specify a directory, then GDB also looks for the file on the source search path (specified with the `directory' command); except that `$cdir' is not searched because the compilation directory is not relevant to scripts. If `-s' is specified, then GDB searches for FILENAME on the search path even if FILENAME specifies a directory. The search is done by appending FILENAME to each element of the search path. So, for example, if FILENAME is `mylib/myscript' and the search path contains `/home/user' then GDB will look for the script `/home/user/mylib/myscript'. The search is also done if FILENAME is an absolute path. For example, if FILENAME is `/tmp/myscript' and the search path contains `/home/user' then GDB will look for the script `/home/user/tmp/myscript'. For DOS-like systems, if FILENAME contains a drive specification, it is stripped before concatenation. For example, if FILENAME is `d:myscript' and the search path contains `c:/tmp' then GDB will look for the script `c:/tmp/myscript'. If `-v', for verbose mode, is given then GDB displays each command as it is executed. The option must be given before FILENAME, and is interpreted as part of the filename anywhere else. Commands that would ask for confirmation if used interactively proceed without asking when used in a command file. Many GDB commands that normally print messages to say what they are doing omit the messages when called from command files. GDB also accepts command input from standard input. In this mode, normal output goes to standard output and error output goes to standard error. Errors in a command file supplied on standard input do not terminate execution of the command file--execution continues with the next command. gdb < cmds > log 2>&1 (The syntax above will vary depending on the shell used.) This example will execute commands from the file `cmds'. All output and errors would be directed to `log'. Since commands stored on command files tend to be more general than commands typed interactively, they frequently need to deal with complicated situations, such as different or unexpected values of variables and symbols, changes in how the program being debugged is built, etc. GDB provides a set of flow-control commands to deal with these complexities. Using these commands, you can write complex scripts that loop over data structures, execute commands conditionally, etc. `if' `else' This command allows to include in your script conditionally executed commands. The `if' command takes a single argument, which is an expression to evaluate. It is followed by a series of commands that are executed only if the expression is true (its value is nonzero). There can then optionally be an `else' line, followed by a series of commands that are only executed if the expression was false. The end of the list is marked by a line containing `end'. `while' This command allows to write loops. Its syntax is similar to `if': the command takes a single argument, which is an expression to evaluate, and must be followed by the commands to execute, one per line, terminated by an `end'. These commands are called the "body" of the loop. The commands in the body of `while' are executed repeatedly as long as the expression evaluates to true. `loop_break' This command exits the `while' loop in whose body it is included. Execution of the script continues after that `while's `end' line. `loop_continue' This command skips the execution of the rest of the body of commands in the `while' loop in whose body it is included. Execution branches to the beginning of the `while' loop, where it evaluates the controlling expression. `end' Terminate the block of commands that are the body of `if', `else', or `while' flow-control commands.  File: gdb.info, Node: Output, Next: Auto-loading sequences, Prev: Command Files, Up: Sequences 23.1.4 Commands for Controlled Output ------------------------------------- During the execution of a command file or a user-defined command, normal GDB output is suppressed; the only output that appears is what is explicitly printed by the commands in the definition. This section describes three commands useful for generating exactly the output you want. `echo TEXT' Print TEXT. Nonprinting characters can be included in TEXT using C escape sequences, such as `\n' to print a newline. *No newline is printed unless you specify one.* In addition to the standard C escape sequences, a backslash followed by a space stands for a space. This is useful for displaying a string with spaces at the beginning or the end, since leading and trailing spaces are otherwise trimmed from all arguments. To print ` and foo = ', use the command `echo \ and foo = \ '. A backslash at the end of TEXT can be used, as in C, to continue the command onto subsequent lines. For example, echo This is some text\n\ which is continued\n\ onto several lines.\n produces the same output as echo This is some text\n echo which is continued\n echo onto several lines.\n `output EXPRESSION' Print the value of EXPRESSION and nothing but that value: no newlines, no `$NN = '. The value is not entered in the value history either. *Note Expressions: Expressions, for more information on expressions. `output/FMT EXPRESSION' Print the value of EXPRESSION in format FMT. You can use the same formats as for `print'. *Note Output Formats: Output Formats, for more information. `printf TEMPLATE, EXPRESSIONS...' Print the values of one or more EXPRESSIONS under the control of the string TEMPLATE. To print several values, make EXPRESSIONS be a comma-separated list of individual expressions, which may be either numbers or pointers. Their values are printed as specified by TEMPLATE, exactly as a C program would do by executing the code below: printf (TEMPLATE, EXPRESSIONS...); As in `C' `printf', ordinary characters in TEMPLATE are printed verbatim, while "conversion specification" introduced by the `%' character cause subsequent EXPRESSIONS to be evaluated, their values converted and formatted according to type and style information encoded in the conversion specifications, and then printed. For example, you can print two values in hex like this: printf "foo, bar-foo = 0x%x, 0x%x\n", foo, bar-foo `printf' supports all the standard `C' conversion specifications, including the flags and modifiers between the `%' character and the conversion letter, with the following exceptions: * The argument-ordering modifiers, such as `2$', are not supported. * The modifier `*' is not supported for specifying precision or width. * The `'' flag (for separation of digits into groups according to `LC_NUMERIC'') is not supported. * The type modifiers `hh', `j', `t', and `z' are not supported. * The conversion letter `n' (as in `%n') is not supported. * The conversion letters `a' and `A' are not supported. Note that the `ll' type modifier is supported only if the underlying `C' implementation used to build GDB supports the `long long int' type, and the `L' type modifier is supported only if `long double' type is available. As in `C', `printf' supports simple backslash-escape sequences, such as `\n', `\t', `\\', `\"', `\a', and `\f', that consist of backslash followed by a single character. Octal and hexadecimal escape sequences are not supported. Additionally, `printf' supports conversion specifications for DFP ("Decimal Floating Point") types using the following length modifiers together with a floating point specifier. letters: * `H' for printing `Decimal32' types. * `D' for printing `Decimal64' types. * `DD' for printing `Decimal128' types. If the underlying `C' implementation used to build GDB has support for the three length modifiers for DFP types, other modifiers such as width and precision will also be available for GDB to use. In case there is no such `C' support, no additional modifiers will be available and the value will be printed in the standard way. Here's an example of printing DFP types using the above conversion letters: printf "D32: %Hf - D64: %Df - D128: %DDf\n",1.2345df,1.2E10dd,1.2E1dl Additionally, `printf' supports a special `%V' output format. This format prints the string representation of an expression just as GDB would produce with the standard `print' command (*note Examining Data: Data.): (gdb) print array $1 = {0, 1, 2, 3, 4, 5} (gdb) printf "Array is: %V\n", array Array is: {0, 1, 2, 3, 4, 5} It is possible to include print options with the `%V' format by placing them in `[...]' immediately after the `%V', like this: (gdb) printf "Array is: %V[-array-indexes on]\n", array Array is: {[0] = 0, [1] = 1, [2] = 2, [3] = 3, [4] = 4, [5] = 5} If you need to print a literal `[' directly after a `%V', then just include an empty print options list: (gdb) printf "Array is: %V[][Hello]\n", array Array is: {0, 1, 2, 3, 4, 5}[Hello] `eval TEMPLATE, EXPRESSIONS...' Convert the values of one or more EXPRESSIONS under the control of the string TEMPLATE to a command line, and call it.  File: gdb.info, Node: Auto-loading sequences, Prev: Output, Up: Sequences 23.1.5 Controlling auto-loading native GDB scripts -------------------------------------------------- When a new object file is read (for example, due to the `file' command, or because the inferior has loaded a shared library), GDB will look for the command file `OBJFILE-gdb.gdb'. *Note Auto-loading extensions::. Auto-loading can be enabled or disabled, and the list of auto-loaded scripts can be printed. `set auto-load gdb-scripts [on|off]' Enable or disable the auto-loading of canned sequences of commands scripts. `show auto-load gdb-scripts' Show whether auto-loading of canned sequences of commands scripts is enabled or disabled. `info auto-load gdb-scripts [REGEXP]' Print the list of all canned sequences of commands scripts that GDB auto-loaded. If REGEXP is supplied only canned sequences of commands scripts with matching names are printed.  File: gdb.info, Node: Aliases, Next: Python, Prev: Sequences, Up: Extending GDB 23.2 Command Aliases ==================== Aliases allow you to define alternate spellings for existing commands. For example, if a new GDB command defined in Python (*note Python::) has a long name, it is handy to have an abbreviated version of it that involves less typing. GDB itself uses aliases. For example `s' is an alias of the `step' command even though it is otherwise an ambiguous abbreviation of other commands like `set' and `show'. Aliases are also used to provide shortened or more common versions of multi-word commands. For example, GDB provides the `tty' alias of the `set inferior-tty' command. You can define a new alias with the `alias' command. `alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS]' ALIAS specifies the name of the new alias. Each word of ALIAS must consist of letters, numbers, dashes and underscores. COMMAND specifies the name of an existing command that is being aliased. COMMAND can also be the name of an existing alias. In this case, COMMAND cannot be an alias that has default arguments. The `-a' option specifies that the new alias is an abbreviation of the command. Abbreviations are not used in command completion. The `--' option specifies the end of options, and is useful when ALIAS begins with a dash. You can specify DEFAULT-ARGS for your alias. These DEFAULT-ARGS will be automatically added before the alias arguments typed explicitly on the command line. For example, the below defines an alias `btfullall' that shows all local variables and all frame arguments: (gdb) alias btfullall = backtrace -full -frame-arguments all For more information about DEFAULT-ARGS, see *Note Default Arguments: Command aliases default args. Here is a simple example showing how to make an abbreviation of a command so that there is less to type. Suppose you were tired of typing `disas', the current shortest unambiguous abbreviation of the `disassemble' command and you wanted an even shorter version named `di'. The following will accomplish this. (gdb) alias -a di = disas Note that aliases are different from user-defined commands. With a user-defined command, you also need to write documentation for it with the `document' command. An alias automatically picks up the documentation of the existing command. Here is an example where we make `elms' an abbreviation of `elements' in the `set print elements' command. This is to show that you can make an abbreviation of any part of a command. (gdb) alias -a set print elms = set print elements (gdb) alias -a show print elms = show print elements (gdb) set p elms 200 (gdb) show p elms Limit on string chars or array elements to print is 200. Note that if you are defining an alias of a `set' command, and you want to have an alias for the corresponding `show' command, then you need to define the latter separately. Unambiguously abbreviated commands are allowed in COMMAND and ALIAS, just as they are normally. (gdb) alias -a set pr elms = set p ele Finally, here is an example showing the creation of a one word alias for a more complex command. This creates alias `spe' of the command `set print elements'. (gdb) alias spe = set print elements (gdb) spe 20 * Menu: * Command aliases default args:: Default arguments for aliases  File: gdb.info, Node: Command aliases default args, Up: Aliases 23.2.1 Default Arguments ------------------------ You can tell GDB to always prepend some default arguments to the list of arguments provided explicitly by the user when using a user-defined alias. If you repeatedly use the same arguments or options for a command, you can define an alias for this command and tell GDB to automatically prepend these arguments or options to the list of arguments you type explicitly when using the alias(1). For example, if you often use the command `thread apply all' specifying to work on the threads in ascending order and to continue in case it encounters an error, you can tell GDB to automatically preprend the `-ascending' and `-c' options by using: (gdb) alias thread apply asc-all = thread apply all -ascending -c Once you have defined this alias with its default args, any time you type the `thread apply asc-all' followed by `some arguments', GDB will execute `thread apply all -ascending -c some arguments'. To have even less to type, you can also define a one word alias: (gdb) alias t_a_c = thread apply all -ascending -c As usual, unambiguous abbreviations can be used for ALIAS and DEFAULT-ARGS. The different aliases of a command do not share their default args. For example, you define a new alias `bt_ALL' showing all possible information and another alias `bt_SMALL' showing very limited information using: (gdb) alias bt_ALL = backtrace -entry-values both -frame-arg all \ -past-main -past-entry -full (gdb) alias bt_SMALL = backtrace -entry-values no -frame-arg none \ -past-main off -past-entry off (For more on using the `alias' command, see *Note Aliases::.) Default args are not limited to the arguments and options of COMMAND, but can specify nested commands if COMMAND accepts such a nested command as argument. For example, the below defines `faalocalsoftype' that lists the frames having locals of a certain type, together with the matching local vars: (gdb) alias faalocalsoftype = frame apply all info locals -q -t (gdb) faalocalsoftype int #1 0x55554f5e in sleeper_or_burner (v=0xdf50) at sleepers.c:86 i = 0 ret = 21845 This is also very useful to define an alias for a set of nested `with' commands to have a particular combination of temporary settings. For example, the below defines the alias `pp10' that pretty prints an expression argument, with a maximum of 10 elements if the expression is a string or an array: (gdb) alias pp10 = with print pretty -- with print elements 10 -- print This defines the alias `pp10' as being a sequence of 3 commands. The first part `with print pretty --' temporarily activates the setting `set print pretty', then launches the command that follows the separator `--'. The command following the first part is also a `with' command that temporarily changes the setting `set print elements' to 10, then launches the command that follows the second separator `--'. The third part `print' is the command the `pp10' alias will launch, using the temporary values of the settings and the arguments explicitly given by the user. For more information about the `with' command usage, see *Note Command Settings::. By default, asking the help for an alias shows the documentation of the aliased command. When the alias is a set of nested commands, `help' of an alias shows the documentation of the first command. This help is not particularly useful for an alias such as `pp10'. For such an alias, it is useful to give a specific documentation using the `document' command (*note document: Define.). ---------- Footnotes ---------- (1) GDB could easily accept default arguments for pre-defined commands and aliases, but it was deemed this would be confusing, and so is not allowed.  File: gdb.info, Node: Python, Next: Guile, Prev: Aliases, Up: Extending GDB 23.3 Extending GDB using Python =============================== You can extend GDB using the Python programming language (http://www.python.org/). This feature is available only if GDB was configured using `--with-python'. Python scripts used by GDB should be installed in `DATA-DIRECTORY/python', where DATA-DIRECTORY is the data directory as determined at GDB startup (*note Data Files::). This directory, known as the "python directory", is automatically added to the Python Search Path in order to allow the Python interpreter to locate all scripts installed at this location. Additionally, GDB commands and convenience functions which are written in Python and are located in the `DATA-DIRECTORY/python/gdb/command' or `DATA-DIRECTORY/python/gdb/function' directories are automatically imported when GDB starts. * Menu: * Python Commands:: Accessing Python from GDB. * Python API:: Accessing GDB from Python. * Python Auto-loading:: Automatically loading Python code. * Python modules:: Python modules provided by GDB.  File: gdb.info, Node: Python Commands, Next: Python API, Up: Python 23.3.1 Python Commands ---------------------- GDB provides two commands for accessing the Python interpreter, and one related setting: `python-interactive [COMMAND]' `pi [COMMAND]' Without an argument, the `python-interactive' command can be used to start an interactive Python prompt. To return to GDB, type the `EOF' character (e.g., `Ctrl-D' on an empty prompt). Alternatively, a single-line Python command can be given as an argument and evaluated. If the command is an expression, the result will be printed; otherwise, nothing will be printed. For example: (gdb) python-interactive 2 + 3 5 `python [COMMAND]' `py [COMMAND]' The `python' command can be used to evaluate Python code. If given an argument, the `python' command will evaluate the argument as a Python command. For example: (gdb) python print 23 23 If you do not provide an argument to `python', it will act as a multi-line command, like `define'. In this case, the Python script is made up of subsequent command lines, given after the `python' command. This command list is terminated using a line containing `end'. For example: (gdb) python >print 23 >end 23 `set python print-stack' By default, GDB will print only the message component of a Python exception when an error occurs in a Python script. This can be controlled using `set python print-stack': if `full', then full Python stack printing is enabled; if `none', then Python stack and message printing is disabled; if `message', the default, only the message component of the error is printed. `set python ignore-environment [on|off]' By default this option is `off', and, when GDB initializes its internal Python interpreter, the Python interpreter will check the environment for variables that will effect how it behaves, for example `PYTHONHOME', and `PYTHONPATH'(1). If this option is set to `on' before Python is initialized then Python will ignore all such environment variables. As Python is initialized early during GDB's startup process, then this option must be placed into the early initialization file (*note Initialization Files::) to have the desired effect. This option is equivalent to passing `-E' to the real `python' executable. `set python dont-write-bytecode [auto|on|off]' When this option is `off', then, once GDB has initialized the Python interpreter, the interpreter will byte-compile any Python modules that it imports and write the byte code to disk in `.pyc' files. If this option is set to `on' before Python is initialized then Python will no longer write the byte code to disk. As Python is initialized early during GDB's startup process, then this option must be placed into the early initialization file (*note Initialization Files::) to have the desired effect. By default this option is set to `auto'. In this mode, provided the `python ignore-environment' setting is `off', the environment variable `PYTHONDONTWRITEBYTECODE' is examined to see if it should write out byte-code or not. `PYTHONDONTWRITEBYTECODE' is considered to be off/disabled either when set to the empty string or when the environment variable doesn't exist. All other settings, including those which don't seem to make sense, indicate that it's on/enabled. This option is equivalent to passing `-B' to the real `python' executable. It is also possible to execute a Python script from the GDB interpreter: `source `script-name'' The script name must end with `.py' and GDB must be configured to recognize the script language based on filename extension using the `script-extension' setting. *Note Extending GDB: Extending GDB. The following commands are intended to help debug GDB itself: `set debug py-breakpoint on|off' `show debug py-breakpoint' When `on', GDB prints debug messages related to the Python breakpoint API. This is `off' by default. `set debug py-unwind on|off' `show debug py-unwind' When `on', GDB prints debug messages related to the Python unwinder API. This is `off' by default. ---------- Footnotes ---------- (1) See the ENVIRONMENT VARIABLES section of `man 1 python' for a comprehensive list.  File: gdb.info, Node: Python API, Next: Python Auto-loading, Prev: Python Commands, Up: Python 23.3.2 Python API ----------------- You can get quick online help for GDB's Python API by issuing the command `python help (gdb)'. Functions and methods which have two or more optional arguments allow them to be specified using keyword syntax. This allows passing some optional arguments while skipping others. Example: `gdb.some_function ('foo', bar = 1, baz = 2)'. * Menu: * Basic Python:: Basic Python Functions. * Threading in GDB:: Using Python threads in GDB. * Exception Handling:: How Python exceptions are translated. * Values From Inferior:: Python representation of values. * Types In Python:: Python representation of types. * Pretty Printing API:: Pretty-printing values. * Selecting Pretty-Printers:: How GDB chooses a pretty-printer. * Writing a Pretty-Printer:: Writing a Pretty-Printer. * Type Printing API:: Pretty-printing types. * Frame Filter API:: Filtering Frames. * Frame Decorator API:: Decorating Frames. * Writing a Frame Filter:: Writing a Frame Filter. * Unwinding Frames in Python:: Writing frame unwinder. * Xmethods In Python:: Adding and replacing methods of C++ classes. * Xmethod API:: Xmethod types. * Writing an Xmethod:: Writing an xmethod. * Inferiors In Python:: Python representation of inferiors (processes) * Events In Python:: Listening for events from GDB. * Threads In Python:: Accessing inferior threads from Python. * Recordings In Python:: Accessing recordings from Python. * CLI Commands In Python:: Implementing new CLI commands in Python. * GDB/MI Commands In Python:: Implementing new GDB/MI commands in Python. * GDB/MI Notifications In Python:: Implementing new GDB/MI notifications in Python. * Parameters In Python:: Adding new GDB parameters. * Functions In Python:: Writing new convenience functions. * Progspaces In Python:: Program spaces. * Objfiles In Python:: Object files. * Frames In Python:: Accessing inferior stack frames from Python. * Blocks In Python:: Accessing blocks from Python. * Symbols In Python:: Python representation of symbols. * Symbol Tables In Python:: Python representation of symbol tables. * Line Tables In Python:: Python representation of line tables. * Breakpoints In Python:: Manipulating breakpoints using Python. * Finish Breakpoints in Python:: Setting Breakpoints on function return using Python. * Lazy Strings In Python:: Python representation of lazy strings. * Architectures In Python:: Python representation of architectures. * Registers In Python:: Python representation of registers. * Connections In Python:: Python representation of connections. * TUI Windows In Python:: Implementing new TUI windows. * Disassembly In Python:: Instruction Disassembly In Python * Missing Debug Info In Python:: Handle missing debug info from Python.  File: gdb.info, Node: Basic Python, Next: Threading in GDB, Up: Python API 23.3.2.1 Basic Python ..................... At startup, GDB overrides Python's `sys.stdout' and `sys.stderr' to print using GDB's output-paging streams. A Python program which outputs to one of these streams may have its output interrupted by the user (*note Screen Size::). In this situation, a Python `KeyboardInterrupt' exception is thrown. Some care must be taken when writing Python code to run in GDB. Two things worth noting in particular: * GDB installs handlers for `SIGCHLD' and `SIGINT'. Python code must not override these, or even change the options using `sigaction'. If your program changes the handling of these signals, GDB will most likely stop working correctly. Note that it is unfortunately common for GUI toolkits to install a `SIGCHLD' handler. When creating a new Python thread, you can use `gdb.block_signals' or `gdb.Thread' to handle this correctly; see *Note Threading in GDB::. * GDB takes care to mark its internal file descriptors as close-on-exec. However, this cannot be done in a thread-safe way on all platforms. Your Python programs should be aware of this and should both create new file descriptors with the close-on-exec flag set and arrange to close unneeded file descriptors before starting a child process. GDB introduces a new Python module, named `gdb'. All methods and classes added by GDB are placed in this module. GDB automatically `import's the `gdb' module for use in all scripts evaluated by the `python' command. Some types of the `gdb' module come with a textual representation (accessible through the `repr' or `str' functions). These are offered for debugging purposes only, expect them to change over time. -- Variable: gdb.PYTHONDIR A string containing the python directory (*note Python::). -- Function: gdb.execute (command [, from_tty [, to_string]]) Evaluate COMMAND, a string, as a GDB CLI command. If a GDB exception happens while COMMAND runs, it is translated as described in *Note Exception Handling: Exception Handling. The FROM_TTY flag specifies whether GDB ought to consider this command as having originated from the user invoking it interactively. It must be a boolean value. If omitted, it defaults to `False'. By default, any output produced by COMMAND is sent to GDB's standard output (and to the log output if logging is turned on). If the TO_STRING parameter is `True', then output will be collected by `gdb.execute' and returned as a string. The default is `False', in which case the return value is `None'. If TO_STRING is `True', the GDB virtual terminal will be temporarily set to unlimited width and height, and its pagination will be disabled; *note Screen Size::. -- Function: gdb.breakpoints () Return a sequence holding all of GDB's breakpoints. *Note Breakpoints In Python::, for more information. In GDB version 7.11 and earlier, this function returned `None' if there were no breakpoints. This peculiarity was subsequently fixed, and now `gdb.breakpoints' returns an empty sequence in this case. -- Function: gdb.rbreak (regex [, minsyms [, throttle, [, symtabs ]]]) Return a Python list holding a collection of newly set `gdb.Breakpoint' objects matching function names defined by the REGEX pattern. If the MINSYMS keyword is `True', all system functions (those not explicitly defined in the inferior) will also be included in the match. The THROTTLE keyword takes an integer that defines the maximum number of pattern matches for functions matched by the REGEX pattern. If the number of matches exceeds the integer value of THROTTLE, a `RuntimeError' will be raised and no breakpoints will be created. If THROTTLE is not defined then there is no imposed limit on the maximum number of matches and breakpoints to be created. The SYMTABS keyword takes a Python iterable that yields a collection of `gdb.Symtab' objects and will restrict the search to those functions only contained within the `gdb.Symtab' objects. -- Function: gdb.parameter (parameter) Return the value of a GDB PARAMETER given by its name, a string; the parameter name string may contain spaces if the parameter has a multi-part name. For example, `print object' is a valid parameter name. If the named parameter does not exist, this function throws a `gdb.error' (*note Exception Handling::). Otherwise, the parameter's value is converted to a Python value of the appropriate type, and returned. -- Function: gdb.set_parameter (name, value) Sets the gdb parameter NAME to VALUE. As with `gdb.parameter', the parameter name string may contain spaces if the parameter has a multi-part name. -- Function: gdb.with_parameter (name, value) Create a Python context manager (for use with the Python `with' statement) that temporarily sets the gdb parameter NAME to VALUE. On exit from the context, the previous value will be restored. This uses `gdb.parameter' in its implementation, so it can throw the same exceptions as that function. For example, it's sometimes useful to evaluate some Python code with a particular gdb language: with gdb.with_parameter('language', 'pascal'): ... language-specific operations -- Function: gdb.history (number) Return a value from GDB's value history (*note Value History::). The NUMBER argument indicates which history element to return. If NUMBER is negative, then GDB will take its absolute value and count backward from the last element (i.e., the most recent element) to find the value to return. If NUMBER is zero, then GDB will return the most recent element. If the element specified by NUMBER doesn't exist in the value history, a `gdb.error' exception will be raised. If no exception is raised, the return value is always an instance of `gdb.Value' (*note Values From Inferior::). -- Function: gdb.add_history (value) Takes VALUE, an instance of `gdb.Value' (*note Values From Inferior::), and appends the value this object represents to GDB's value history (*note Value History::), and return an integer, its history number. If VALUE is not a `gdb.Value', it is is converted using the `gdb.Value' constructor. If VALUE can't be converted to a `gdb.Value' then a `TypeError' is raised. When a command implemented in Python prints a single `gdb.Value' as its result, then placing the value into the history will allow the user convenient access to those values via CLI history facilities. -- Function: gdb.history_count () Return an integer indicating the number of values in GDB's value history (*note Value History::). -- Function: gdb.convenience_variable (name) Return the value of the convenience variable (*note Convenience Vars::) named NAME. NAME must be a string. The name should not include the `$' that is used to mark a convenience variable in an expression. If the convenience variable does not exist, then `None' is returned. -- Function: gdb.set_convenience_variable (name, value) Set the value of the convenience variable (*note Convenience Vars::) named NAME. NAME must be a string. The name should not include the `$' that is used to mark a convenience variable in an expression. If VALUE is `None', then the convenience variable is removed. Otherwise, if VALUE is not a `gdb.Value' (*note Values From Inferior::), it is is converted using the `gdb.Value' constructor. -- Function: gdb.parse_and_eval (expression [, global_context]) Parse EXPRESSION, which must be a string, as an expression in the current language, evaluate it, and return the result as a `gdb.Value'. GLOBAL_CONTEXT, if provided, is a boolean indicating whether the parsing should be done in the global context. The default is `False', meaning that the current frame or current static context should be used. This function can be useful when implementing a new command (*note CLI Commands In Python::, *note GDB/MI Commands In Python::), as it provides a way to parse the command's argument as an expression. It is also useful simply to compute values. -- Function: gdb.find_pc_line (pc) Return the `gdb.Symtab_and_line' object corresponding to the PC value. *Note Symbol Tables In Python::. If an invalid value of PC is passed as an argument, then the `symtab' and `line' attributes of the returned `gdb.Symtab_and_line' object will be `None' and 0 respectively. This is identical to `gdb.current_progspace().find_pc_line(pc)' and is included for historical compatibility. -- Function: gdb.write (string [, stream]) Print a string to GDB's paginated output stream. The optional STREAM determines the stream to print to. The default stream is GDB's standard output stream. Possible stream values are: `gdb.STDOUT' GDB's standard output stream. `gdb.STDERR' GDB's standard error stream. `gdb.STDLOG' GDB's log stream (*note Logging Output::). Writing to `sys.stdout' or `sys.stderr' will automatically call this function and will automatically direct the output to the relevant stream. -- Function: gdb.flush ([, stream]) Flush the buffer of a GDB paginated stream so that the contents are displayed immediately. GDB will flush the contents of a stream automatically when it encounters a newline in the buffer. The optional STREAM determines the stream to flush. The default stream is GDB's standard output stream. Possible stream values are: `gdb.STDOUT' GDB's standard output stream. `gdb.STDERR' GDB's standard error stream. `gdb.STDLOG' GDB's log stream (*note Logging Output::). Flushing `sys.stdout' or `sys.stderr' will automatically call this function for the relevant stream. -- Function: gdb.target_charset () Return the name of the current target character set (*note Character Sets::). This differs from `gdb.parameter('target-charset')' in that `auto' is never returned. -- Function: gdb.target_wide_charset () Return the name of the current target wide character set (*note Character Sets::). This differs from `gdb.parameter('target-wide-charset')' in that `auto' is never returned. -- Function: gdb.host_charset () Return a string, the name of the current host character set (*note Character Sets::). This differs from `gdb.parameter('host-charset')' in that `auto' is never returned. -- Function: gdb.solib_name (address) Return the name of the shared library holding the given ADDRESS as a string, or `None'. This is identical to `gdb.current_progspace().solib_name(address)' and is included for historical compatibility. -- Function: gdb.decode_line ([expression]) Return locations of the line specified by EXPRESSION, or of the current line if no argument was given. This function returns a Python tuple containing two elements. The first element contains a string holding any unparsed section of EXPRESSION (or `None' if the expression has been fully parsed). The second element contains either `None' or another tuple that contains all the locations that match the expression represented as `gdb.Symtab_and_line' objects (*note Symbol Tables In Python::). If EXPRESSION is provided, it is decoded the way that GDB's inbuilt `break' or `edit' commands do (*note Location Specifications::). -- Function: gdb.prompt_hook (current_prompt) If PROMPT_HOOK is callable, GDB will call the method assigned to this operation before a prompt is displayed by GDB. The parameter `current_prompt' contains the current GDB prompt. This method must return a Python string, or `None'. If a string is returned, the GDB prompt will be set to that string. If `None' is returned, GDB will continue to use the current prompt. Some prompts cannot be substituted in GDB. Secondary prompts such as those used by readline for command input, and annotation related prompts are prohibited from being changed. -- Function: gdb.architecture_names () Return a list containing all of the architecture names that the current build of GDB supports. Each architecture name is a string. The names returned in this list are the same names as are returned from `gdb.Architecture.name' (*note Architecture.name: gdbpy_architecture_name.). -- Function: gdb.connections Return a list of `gdb.TargetConnection' objects, one for each currently active connection (*note Connections In Python::). The connection objects are in no particular order in the returned list. -- Function: gdb.format_address (address [, progspace, architecture]) Return a string in the format `ADDR ', where ADDR is ADDRESS formatted in hexadecimal, SYMBOL is the symbol whose address is the nearest to ADDRESS and below it in memory, and OFFSET is the offset from SYMBOL to ADDRESS in decimal. If no suitable SYMBOL was found, then the part is not included in the returned string, instead the returned string will just contain the ADDRESS formatted as hexadecimal. How far GDB looks back for a suitable symbol can be controlled with `set print max-symbolic-offset' (*note Print Settings::). Additionally, the returned string can include file name and line number information when `set print symbol-filename on' (*note Print Settings::), in this case the format of the returned string is `ADDR at FILENAME:LINE-NUMBER'. The PROGSPACE is the gdb.Progspace in which SYMBOL is looked up, and ARCHITECTURE is used when formatting ADDR, e.g. in order to determine the size of an address in bytes. If neither PROGSPACE or ARCHITECTURE are passed, then by default GDB will use the program space and architecture of the currently selected inferior, thus, the following two calls are equivalent: gdb.format_address(address) gdb.format_address(address, gdb.selected_inferior().progspace, gdb.selected_inferior().architecture()) It is not valid to only pass one of PROGSPACE or ARCHITECTURE, either they must both be provided, or neither must be provided (and the defaults will be used). This method uses the same mechanism for formatting address, symbol, and offset information as core GDB does in commands such as `disassemble'. Here are some examples of the possible string formats: 0x00001042 0x00001042 0x00001042 -- Function: gdb.current_language () Return the name of the current language as a string. Unlike `gdb.parameter('language')', this function will never return `auto'. If a `gdb.Frame' object is available (*note Frames In Python::), the `language' method might be preferable in some cases, as that is not affected by the user's language setting.  File: gdb.info, Node: Threading in GDB, Next: Exception Handling, Prev: Basic Python, Up: Python API 23.3.2.2 Threading in GDB ......................... GDB is not thread-safe. If your Python program uses multiple threads, you must be careful to only call GDB-specific functions in the GDB thread. GDB provides some functions to help with this. -- Function: gdb.block_signals () As mentioned earlier (*note Basic Python::), certain signals must be delivered to the GDB main thread. The `block_signals' function returns a context manager that will block these signals on entry. This can be used when starting a new thread to ensure that the signals are blocked there, like: with gdb.block_signals(): start_new_thread() -- class: gdb.Thread This is a subclass of Python's `threading.Thread' class. It overrides the `start' method to call `block_signals', making this an easy-to-use drop-in replacement for creating threads that will work well in GDB. -- Function: gdb.interrupt () This causes GDB to react as if the user had typed a control-C character at the terminal. That is, if the inferior is running, it is interrupted; if a GDB command is executing, it is stopped; and if a Python command is running, `KeyboardInterrupt' will be raised. Unlike most Python APIs in GDB, `interrupt' is thread-safe. -- Function: gdb.post_event (event) Put EVENT, a callable object taking no arguments, into GDB's internal event queue. This callable will be invoked at some later point, during GDB's event processing. Events posted using `post_event' will be run in the order in which they were posted; however, there is no way to know when they will be processed relative to other events inside GDB. Unlike most Python APIs in GDB, `post_event' is thread-safe. For example: (gdb) python >import threading > >class Writer(): > def __init__(self, message): > self.message = message; > def __call__(self): > gdb.write(self.message) > >class MyThread1 (threading.Thread): > def run (self): > gdb.post_event(Writer("Hello ")) > >class MyThread2 (threading.Thread): > def run (self): > gdb.post_event(Writer("World\n")) > >MyThread1().start() >MyThread2().start() >end (gdb) Hello World  File: gdb.info, Node: Exception Handling, Next: Values From Inferior, Prev: Threading in GDB, Up: Python API 23.3.2.3 Exception Handling ........................... When executing the `python' command, Python exceptions uncaught within the Python code are translated to calls to GDB error-reporting mechanism. If the command that called `python' does not handle the error, GDB will terminate it and print an error message. Exactly what will be printed depends on `set python print-stack' (*note Python Commands::). Example: (gdb) python print foo Traceback (most recent call last): File "", line 1, in NameError: name 'foo' is not defined GDB errors that happen in GDB commands invoked by Python code are converted to Python exceptions. The type of the Python exception depends on the error. `gdb.error' This is the base class for most exceptions generated by GDB. It is derived from `RuntimeError', for compatibility with earlier versions of GDB. If an error occurring in GDB does not fit into some more specific category, then the generated exception will have this type. `gdb.MemoryError' This is a subclass of `gdb.error' which is thrown when an operation tried to access invalid memory in the inferior. `KeyboardInterrupt' User interrupt (via `C-c' or by typing `q' at a pagination prompt) is translated to a Python `KeyboardInterrupt' exception. In all cases, your exception handler will see the GDB error message as its value and the Python call stack backtrace at the Python statement closest to where the GDB error occurred as the traceback. When implementing GDB commands in Python via `gdb.Command', or functions via `gdb.Function', it is useful to be able to throw an exception that doesn't cause a traceback to be printed. For example, the user may have invoked the command incorrectly. GDB provides a special exception class that can be used for this purpose. `gdb.GdbError' When thrown from a command or function, this exception will cause the command or function to fail, but the Python stack will not be displayed. GDB does not throw this exception itself, but rather recognizes it when thrown from user Python code. Example: (gdb) python >class HelloWorld (gdb.Command): > """Greet the whole world.""" > def __init__ (self): > super (HelloWorld, self).__init__ ("hello-world", gdb.COMMAND_USER) > def invoke (self, args, from_tty): > argv = gdb.string_to_argv (args) > if len (argv) != 0: > raise gdb.GdbError ("hello-world takes no arguments") > print ("Hello, World!") >HelloWorld () >end (gdb) hello-world 42 hello-world takes no arguments  File: gdb.info, Node: Values From Inferior, Next: Types In Python, Prev: Exception Handling, Up: Python API 23.3.2.4 Values From Inferior ............................. GDB provides values it obtains from the inferior program in an object of type `gdb.Value'. GDB uses this object for its internal bookkeeping of the inferior's values, and for fetching values when necessary. Inferior values that are simple scalars can be used directly in Python expressions that are valid for the value's data type. Here's an example for an integer or floating-point value `some_val': bar = some_val + 2 As result of this, `bar' will also be a `gdb.Value' object whose values are of the same type as those of `some_val'. Valid Python operations can also be performed on `gdb.Value' objects representing a `struct' or `class' object. For such cases, the overloaded operator (if present), is used to perform the operation. For example, if `val1' and `val2' are `gdb.Value' objects representing instances of a `class' which overloads the `+' operator, then one can use the `+' operator in their Python script as follows: val3 = val1 + val2 The result of the operation `val3' is also a `gdb.Value' object corresponding to the value returned by the overloaded `+' operator. In general, overloaded operators are invoked for the following operations: `+' (binary addition), `-' (binary subtraction), `*' (multiplication), `/', `%', `<<', `>>', `|', `&', `^'. Inferior values that are structures or instances of some class can be accessed using the Python "dictionary syntax". For example, if `some_val' is a `gdb.Value' instance holding a structure, you can access its `foo' element with: bar = some_val['foo'] Again, `bar' will also be a `gdb.Value' object. Structure elements can also be accessed by using `gdb.Field' objects as subscripts (*note Types In Python::, for more information on `gdb.Field' objects). For example, if `foo_field' is a `gdb.Field' object corresponding to element `foo' of the above structure, then `bar' can also be accessed as follows: bar = some_val[foo_field] If a `gdb.Value' has array or pointer type, an integer index can be used to access elements. result = some_array[23] A `gdb.Value' that represents a function can be executed via inferior function call. Any arguments provided to the call must match the function's prototype, and must be provided in the order specified by that prototype. For example, `some_val' is a `gdb.Value' instance representing a function that takes two integers as arguments. To execute this function, call it like so: result = some_val (10,20) Any values returned from a function call will be stored as a `gdb.Value'. The following attributes are provided: -- Variable: Value.address If this object is addressable, this read-only attribute holds a `gdb.Value' object representing the address. Otherwise, this attribute holds `None'. -- Variable: Value.is_optimized_out This read-only boolean attribute is true if the compiler optimized out this value, thus it is not available for fetching from the inferior. -- Variable: Value.type The type of this `gdb.Value'. The value of this attribute is a `gdb.Type' object (*note Types In Python::). -- Variable: Value.dynamic_type The dynamic type of this `gdb.Value'. This uses the object's virtual table and the C++ run-time type information (RTTI) to determine the dynamic type of the value. If this value is of class type, it will return the class in which the value is embedded, if any. If this value is of pointer or reference to a class type, it will compute the dynamic type of the referenced object, and return a pointer or reference to that type, respectively. In all other cases, it will return the value's static type. Note that this feature will only work when debugging a C++ program that includes RTTI for the object in question. Otherwise, it will just return the static type of the value as in `ptype foo' (*note ptype: Symbols.). -- Variable: Value.is_lazy The value of this read-only boolean attribute is `True' if this `gdb.Value' has not yet been fetched from the inferior. GDB does not fetch values until necessary, for efficiency. For example: myval = gdb.parse_and_eval ('somevar') The value of `somevar' is not fetched at this time. It will be fetched when the value is needed, or when the `fetch_lazy' method is invoked. -- Variable: Value.bytes The value of this attribute is a `bytes' object containing the bytes that make up this `Value''s complete value in little endian order. If the complete contents of this value are not available then accessing this attribute will raise an exception. This attribute can also be assigned to. The new value should be a buffer object (e.g. a `bytes' object), the length of the new buffer must exactly match the length of this `Value''s type. The bytes values in the new buffer should be in little endian order. As with `Value.assign' (*note Value.assign::), if this value cannot be assigned to, then an exception will be thrown. The following methods are provided: -- Function: Value.__init__ (val) Many Python values can be converted directly to a `gdb.Value' via this object initializer. Specifically: Python boolean A Python boolean is converted to the boolean type from the current language. Python integer A Python integer is converted to the C `long' type for the current architecture. Python long A Python long is converted to the C `long long' type for the current architecture. Python float A Python float is converted to the C `double' type for the current architecture. Python string A Python string is converted to a target string in the current target language using the current target encoding. If a character cannot be represented in the current target encoding, then an exception is thrown. `gdb.Value' If `val' is a `gdb.Value', then a copy of the value is made. `gdb.LazyString' If `val' is a `gdb.LazyString' (*note Lazy Strings In Python::), then the lazy string's `value' method is called, and its result is used. -- Function: Value.__init__ (val, type) This second form of the `gdb.Value' constructor returns a `gdb.Value' of type TYPE where the value contents are taken from the Python buffer object specified by VAL. The number of bytes in the Python buffer object must be greater than or equal to the size of TYPE. If TYPE is `None' then this version of `__init__' behaves as though TYPE was not passed at all. -- Function: Value.assign (rhs) Assign RHS to this value, and return `None'. If this value cannot be assigned to, or if the assignment is invalid for some reason (for example a type-checking failure), an exception will be thrown. -- Function: Value.cast (type) Return a new instance of `gdb.Value' that is the result of casting this instance to the type described by TYPE, which must be a `gdb.Type' object. If the cast cannot be performed for some reason, this method throws an exception. -- Function: Value.dereference () For pointer data types, this method returns a new `gdb.Value' object whose contents is the object pointed to by the pointer. For example, if `foo' is a C pointer to an `int', declared in your C program as int *foo; then you can use the corresponding `gdb.Value' to access what `foo' points to like this: bar = foo.dereference () The result `bar' will be a `gdb.Value' object holding the value pointed to by `foo'. A similar function `Value.referenced_value' exists which also returns `gdb.Value' objects corresponding to the values pointed to by pointer values (and additionally, values referenced by reference values). However, the behavior of `Value.dereference' differs from `Value.referenced_value' by the fact that the behavior of `Value.dereference' is identical to applying the C unary operator `*' on a given value. For example, consider a reference to a pointer `ptrref', declared in your C++ program as typedef int *intptr; ... int val = 10; intptr ptr = &val; intptr &ptrref = ptr; Though `ptrref' is a reference value, one can apply the method `Value.dereference' to the `gdb.Value' object corresponding to it and obtain a `gdb.Value' which is identical to that corresponding to `val'. However, if you apply the method `Value.referenced_value', the result would be a `gdb.Value' object identical to that corresponding to `ptr'. py_ptrref = gdb.parse_and_eval ("ptrref") py_val = py_ptrref.dereference () py_ptr = py_ptrref.referenced_value () The `gdb.Value' object `py_val' is identical to that corresponding to `val', and `py_ptr' is identical to that corresponding to `ptr'. In general, `Value.dereference' can be applied whenever the C unary operator `*' can be applied to the corresponding C value. For those cases where applying both `Value.dereference' and `Value.referenced_value' is allowed, the results obtained need not be identical (as we have seen in the above example). The results are however identical when applied on `gdb.Value' objects corresponding to pointers (`gdb.Value' objects with type code `TYPE_CODE_PTR') in a C/C++ program. -- Function: Value.referenced_value () For pointer or reference data types, this method returns a new `gdb.Value' object corresponding to the value referenced by the pointer/reference value. For pointer data types, `Value.dereference' and `Value.referenced_value' produce identical results. The difference between these methods is that `Value.dereference' cannot get the values referenced by reference values. For example, consider a reference to an `int', declared in your C++ program as int val = 10; int &ref = val; then applying `Value.dereference' to the `gdb.Value' object corresponding to `ref' will result in an error, while applying `Value.referenced_value' will result in a `gdb.Value' object identical to that corresponding to `val'. py_ref = gdb.parse_and_eval ("ref") er_ref = py_ref.dereference () # Results in error py_val = py_ref.referenced_value () # Returns the referenced value The `gdb.Value' object `py_val' is identical to that corresponding to `val'. -- Function: Value.reference_value () Return a `gdb.Value' object which is a reference to the value encapsulated by this instance. -- Function: Value.const_value () Return a `gdb.Value' object which is a `const' version of the value encapsulated by this instance. -- Function: Value.dynamic_cast (type) Like `Value.cast', but works as if the C++ `dynamic_cast' operator were used. Consult a C++ reference for details. -- Function: Value.reinterpret_cast (type) Like `Value.cast', but works as if the C++ `reinterpret_cast' operator were used. Consult a C++ reference for details. -- Function: Value.format_string (...) Convert a `gdb.Value' to a string, similarly to what the `print' command does. Invoked with no arguments, this is equivalent to calling the `str' function on the `gdb.Value'. The representation of the same value may change across different versions of GDB, so you shouldn't, for instance, parse the strings returned by this method. All the arguments are keyword only. If an argument is not specified, the current global default setting is used. `raw' `True' if pretty-printers (*note Pretty Printing::) should not be used to format the value. `False' if enabled pretty-printers matching the type represented by the `gdb.Value' should be used to format it. `pretty_arrays' `True' if arrays should be pretty printed to be more convenient to read, `False' if they shouldn't (see `set print array' in *Note Print Settings::). `pretty_structs' `True' if structs should be pretty printed to be more convenient to read, `False' if they shouldn't (see `set print pretty' in *Note Print Settings::). `array_indexes' `True' if array indexes should be included in the string representation of arrays, `False' if they shouldn't (see `set print array-indexes' in *Note Print Settings::). `symbols' `True' if the string representation of a pointer should include the corresponding symbol name (if one exists), `False' if it shouldn't (see `set print symbol' in *Note Print Settings::). `unions' `True' if unions which are contained in other structures or unions should be expanded, `False' if they shouldn't (see `set print union' in *Note Print Settings::). `address' `True' if the string representation of a pointer should include the address, `False' if it shouldn't (see `set print address' in *Note Print Settings::). `nibbles' `True' if binary values should be displayed in groups of four bits, known as nibbles. `False' if it shouldn't (*note set print nibbles: Print Settings.). `deref_refs' `True' if C++ references should be resolved to the value they refer to, `False' (the default) if they shouldn't. Note that, unlike for the `print' command, references are not automatically expanded when using the `format_string' method or the `str' function. There is no global `print' setting to change the default behaviour. `actual_objects' `True' if the representation of a pointer to an object should identify the _actual_ (derived) type of the object rather than the _declared_ type, using the virtual function table. `False' if the _declared_ type should be used. (See `set print object' in *Note Print Settings::). `static_members' `True' if static members should be included in the string representation of a C++ object, `False' if they shouldn't (see `set print static-members' in *Note Print Settings::). `max_characters' Number of string characters to print, `0' to follow `max_elements', or `UINT_MAX' to print an unlimited number of characters (see `set print characters' in *Note Print Settings::). `max_elements' Number of array elements to print, or `0' to print an unlimited number of elements (see `set print elements' in *Note Print Settings::). `max_depth' The maximum depth to print for nested structs and unions, or `-1' to print an unlimited number of elements (see `set print max-depth' in *Note Print Settings::). `repeat_threshold' Set the threshold for suppressing display of repeated array elements, or `0' to represent all elements, even if repeated. (See `set print repeats' in *Note Print Settings::). `format' A string containing a single character representing the format to use for the returned string. For instance, `'x'' is equivalent to using the GDB command `print' with the `/x' option and formats the value as a hexadecimal number. `styling' `True' if GDB should apply styling to the returned string. When styling is applied, the returned string might contain ANSI terminal escape sequences. Escape sequences will only be included if styling is turned on, see *Note Output Styling::. Additionally, GDB only styles some value contents, so not every output string will contain escape sequences. When `False', which is the default, no output styling is applied. `summary' `True' when just a summary should be printed. In this mode, scalar values are printed in their entirety, but aggregates such as structures or unions are omitted. This mode is used by `set print frame-arguments scalars' (*note Print Settings::). -- Function: Value.to_array () If this value is array-like (*note Type.is_array_like::), then this method converts it to an array, which is returned. If this value is already an array, it is simply returned. Otherwise, an exception is throw. -- Function: Value.string ([encoding[, errors[, length]]]) If this `gdb.Value' represents a string, then this method converts the contents to a Python string. Otherwise, this method will throw an exception. Values are interpreted as strings according to the rules of the current language. If the optional length argument is given, the string will be converted to that length, and will include any embedded zeroes that the string may contain. Otherwise, for languages where the string is zero-terminated, the entire string will be converted. For example, in C-like languages, a value is a string if it is a pointer to or an array of characters or ints of type `wchar_t', `char16_t', or `char32_t'. If the optional ENCODING argument is given, it must be a string naming the encoding of the string in the `gdb.Value', such as `"ascii"', `"iso-8859-6"' or `"utf-8"'. It accepts the same encodings as the corresponding argument to Python's `string.decode' method, and the Python codec machinery will be used to convert the string. If ENCODING is not given, or if ENCODING is the empty string, then either the `target-charset' (*note Character Sets::) will be used, or a language-specific encoding will be used, if the current language is able to supply one. The optional ERRORS argument is the same as the corresponding argument to Python's `string.decode' method. If the optional LENGTH argument is given, the string will be fetched and converted to the given length. -- Function: Value.lazy_string ([encoding [, length]]) If this `gdb.Value' represents a string, then this method converts the contents to a `gdb.LazyString' (*note Lazy Strings In Python::). Otherwise, this method will throw an exception. If the optional ENCODING argument is given, it must be a string naming the encoding of the `gdb.LazyString'. Some examples are: `ascii', `iso-8859-6' or `utf-8'. If the ENCODING argument is an encoding that GDB does recognize, GDB will raise an error. When a lazy string is printed, the GDB encoding machinery is used to convert the string during printing. If the optional ENCODING argument is not provided, or is an empty string, GDB will automatically select the encoding most suitable for the string type. For further information on encoding in GDB please see *Note Character Sets::. If the optional LENGTH argument is given, the string will be fetched and encoded to the length of characters specified. If the LENGTH argument is not provided, the string will be fetched and encoded until a null of appropriate width is found. -- Function: Value.fetch_lazy () If the `gdb.Value' object is currently a lazy value (`gdb.Value.is_lazy' is `True'), then the value is fetched from the inferior. Any errors that occur in the process will produce a Python exception. If the `gdb.Value' object is not a lazy value, this method has no effect. This method does not return a value.  File: gdb.info, Node: Types In Python, Next: Pretty Printing API, Prev: Values From Inferior, Up: Python API 23.3.2.5 Types In Python ........................ GDB represents types from the inferior using the class `gdb.Type'. The following type-related functions are available in the `gdb' module: -- Function: gdb.lookup_type (name [, block]) This function looks up a type by its NAME, which must be a string. If BLOCK is given, then NAME is looked up in that scope. Otherwise, it is searched for globally. Ordinarily, this function will return an instance of `gdb.Type'. If the named type cannot be found, it will throw an exception. Integer types can be found without looking them up by name. *Note Architectures In Python::, for the `integer_type' method. If the type is a structure or class type, or an enum type, the fields of that type can be accessed using the Python "dictionary syntax". For example, if `some_type' is a `gdb.Type' instance holding a structure type, you can access its `foo' field with: bar = some_type['foo'] `bar' will be a `gdb.Field' object; see below under the description of the `Type.fields' method for a description of the `gdb.Field' class. An instance of `Type' has the following attributes: -- Variable: Type.alignof The alignment of this type, in bytes. Type alignment comes from the debugging information; if it was not specified, then GDB will use the relevant ABI to try to determine the alignment. In some cases, even this is not possible, and zero will be returned. -- Variable: Type.code The type code for this type. The type code will be one of the `TYPE_CODE_' constants defined below. -- Variable: Type.dynamic A boolean indicating whether this type is dynamic. In some situations, such as Rust `enum' types or Ada variant records, the concrete type of a value may vary depending on its contents. That is, the declared type of a variable, or the type returned by `gdb.lookup_type' may be dynamic; while the type of the variable's value will be a concrete instance of that dynamic type. For example, consider this code: int n; int array[n]; Here, at least conceptually (whether your compiler actually does this is a separate issue), examining `gdb.lookup_symbol("array", ...).type' could yield a `gdb.Type' which reports a size of `None'. This is the dynamic type. However, examining `gdb.parse_and_eval("array").type' would yield a concrete type, whose length would be known. -- Variable: Type.name The name of this type. If this type has no name, then `None' is returned. -- Variable: Type.sizeof The size of this type, in target `char' units. Usually, a target's `char' type will be an 8-bit byte. However, on some unusual platforms, this type may have a different size. A dynamic type may not have a fixed size; in this case, this attribute's value will be `None'. -- Variable: Type.tag The tag name for this type. The tag name is the name after `struct', `union', or `enum' in C and C++; not all languages have this concept. If this type has no tag name, then `None' is returned. -- Variable: Type.objfile The `gdb.Objfile' that this type was defined in, or `None' if there is no associated objfile. -- Variable: Type.is_scalar This property is `True' if the type is a scalar type, otherwise, this property is `False'. Examples of non-scalar types include structures, unions, and classes. -- Variable: Type.is_signed For scalar types (those for which `Type.is_scalar' is `True'), this property is `True' if the type is signed, otherwise this property is `False'. Attempting to read this property for a non-scalar type (a type for which `Type.is_scalar' is `False'), will raise a `ValueError'. -- Variable: Type.is_array_like A boolean indicating whether this type is array-like. Some languages have array-like objects that are represented internally as structures. For example, this is true for a Rust slice type, or for an Ada unconstrained array. GDB may know about these types. This determination is done based on the language from which the type originated. -- Variable: Type.is_string_like A boolean indicating whether this type is string-like. Like `Type.is_array_like', this is determined based on the originating language of the type. The following methods are provided: -- Function: Type.fields () Return the fields of this type. The behavior depends on the type code: * For structure and union types, this method returns the fields. * Enum types have one field per enum constant. * Function and method types have one field per parameter. The base types of C++ classes are also represented as fields. * Array types have one field representing the array's range. * If the type does not fit into one of these categories, a `TypeError' is raised. Each field is a `gdb.Field' object, with some pre-defined attributes: `bitpos' This attribute is not available for `enum' or `static' (as in C++) fields. The value is the position, counting in bits, from the start of the containing type. Note that, in a dynamic type, the position of a field may not be constant. In this case, the value will be `None'. Also, a dynamic type may have fields that do not appear in a corresponding concrete type. `enumval' This attribute is only available for `enum' fields, and its value is the enumeration member's integer representation. `name' The name of the field, or `None' for anonymous fields. `artificial' This is `True' if the field is artificial, usually meaning that it was provided by the compiler and not the user. This attribute is always provided, and is `False' if the field is not artificial. `is_base_class' This is `True' if the field represents a base class of a C++ structure. This attribute is always provided, and is `False' if the field is not a base class of the type that is the argument of `fields', or if that type was not a C++ class. `bitsize' If the field is packed, or is a bitfield, then this will have a non-zero value, which is the size of the field in bits. Otherwise, this will be zero; in this case the field's size is given by its type. `type' The type of the field. This is usually an instance of `Type', but it can be `None' in some situations. `parent_type' The type which contains this field. This is an instance of `gdb.Type'. -- Function: Type.array (n1 [, n2]) Return a new `gdb.Type' object which represents an array of this type. If one argument is given, it is the inclusive upper bound of the array; in this case the lower bound is zero. If two arguments are given, the first argument is the lower bound of the array, and the second argument is the upper bound of the array. An array's length must not be negative, but the bounds can be. -- Function: Type.vector (n1 [, n2]) Return a new `gdb.Type' object which represents a vector of this type. If one argument is given, it is the inclusive upper bound of the vector; in this case the lower bound is zero. If two arguments are given, the first argument is the lower bound of the vector, and the second argument is the upper bound of the vector. A vector's length must not be negative, but the bounds can be. The difference between an `array' and a `vector' is that arrays behave like in C: when used in expressions they decay to a pointer to the first element whereas vectors are treated as first class values. -- Function: Type.const () Return a new `gdb.Type' object which represents a `const'-qualified variant of this type. -- Function: Type.volatile () Return a new `gdb.Type' object which represents a `volatile'-qualified variant of this type. -- Function: Type.unqualified () Return a new `gdb.Type' object which represents an unqualified variant of this type. That is, the result is neither `const' nor `volatile'. -- Function: Type.range () Return a Python `Tuple' object that contains two elements: the low bound of the argument type and the high bound of that type. If the type does not have a range, GDB will raise a `gdb.error' exception (*note Exception Handling::). -- Function: Type.reference () Return a new `gdb.Type' object which represents a reference to this type. -- Function: Type.pointer () Return a new `gdb.Type' object which represents a pointer to this type. -- Function: Type.strip_typedefs () Return a new `gdb.Type' that represents the real type, after removing all layers of typedefs. -- Function: Type.target () Return a new `gdb.Type' object which represents the target type of this type. For a pointer type, the target type is the type of the pointed-to object. For an array type (meaning C-like arrays), the target type is the type of the elements of the array. For a function or method type, the target type is the type of the return value. For a complex type, the target type is the type of the elements. For a typedef, the target type is the aliased type. If the type does not have a target, this method will throw an exception. -- Function: Type.template_argument (n [, block]) If this `gdb.Type' is an instantiation of a template, this will return a new `gdb.Value' or `gdb.Type' which represents the value of the Nth template argument (indexed starting at 0). If this `gdb.Type' is not a template type, or if the type has fewer than N template arguments, this will throw an exception. Ordinarily, only C++ code will have template types. If BLOCK is given, then NAME is looked up in that scope. Otherwise, it is searched for globally. -- Function: Type.optimized_out () Return `gdb.Value' instance of this type whose value is optimized out. This allows a frame decorator to indicate that the value of an argument or a local variable is not known. Each type has a code, which indicates what category this type falls into. The available type categories are represented by constants defined in the `gdb' module: `gdb.TYPE_CODE_PTR' The type is a pointer. `gdb.TYPE_CODE_ARRAY' The type is an array. `gdb.TYPE_CODE_STRUCT' The type is a structure. `gdb.TYPE_CODE_UNION' The type is a union. `gdb.TYPE_CODE_ENUM' The type is an enum. `gdb.TYPE_CODE_FLAGS' A bit flags type, used for things such as status registers. `gdb.TYPE_CODE_FUNC' The type is a function. `gdb.TYPE_CODE_INT' The type is an integer type. `gdb.TYPE_CODE_FLT' A floating point type. `gdb.TYPE_CODE_VOID' The special type `void'. `gdb.TYPE_CODE_SET' A Pascal set type. `gdb.TYPE_CODE_RANGE' A range type, that is, an integer type with bounds. `gdb.TYPE_CODE_STRING' A string type. Note that this is only used for certain languages with language-defined string types; C strings are not represented this way. `gdb.TYPE_CODE_BITSTRING' A string of bits. It is deprecated. `gdb.TYPE_CODE_ERROR' An unknown or erroneous type. `gdb.TYPE_CODE_METHOD' A method type, as found in C++. `gdb.TYPE_CODE_METHODPTR' A pointer-to-member-function. `gdb.TYPE_CODE_MEMBERPTR' A pointer-to-member. `gdb.TYPE_CODE_REF' A reference type. `gdb.TYPE_CODE_RVALUE_REF' A C++11 rvalue reference type. `gdb.TYPE_CODE_CHAR' A character type. `gdb.TYPE_CODE_BOOL' A boolean type. `gdb.TYPE_CODE_COMPLEX' A complex float type. `gdb.TYPE_CODE_TYPEDEF' A typedef to some other type. `gdb.TYPE_CODE_NAMESPACE' A C++ namespace. `gdb.TYPE_CODE_DECFLOAT' A decimal floating point type. `gdb.TYPE_CODE_INTERNAL_FUNCTION' A function internal to GDB. This is the type used to represent convenience functions. `gdb.TYPE_CODE_XMETHOD' A method internal to GDB. This is the type used to represent xmethods (*note Writing an Xmethod::). `gdb.TYPE_CODE_FIXED_POINT' A fixed-point number. `gdb.TYPE_CODE_NAMESPACE' A Fortran namelist. Further support for types is provided in the `gdb.types' Python module (*note gdb.types::).  File: gdb.info, Node: Pretty Printing API, Next: Selecting Pretty-Printers, Prev: Types In Python, Up: Python API 23.3.2.6 Pretty Printing API ............................ A pretty-printer is just an object that holds a value and implements a specific interface, defined here. An example output is provided (*note Pretty Printing::). Because GDB did not document extensibility for pretty-printers, by default GDB will assume that only the basic pretty-printer methods may be available. The basic methods are marked as such, below. To allow extensibility, GDB provides the `gdb.ValuePrinter' base class. This class does not provide any attributes or behavior, but instead serves as a tag that can be recognized by GDB. For such printers, GDB reserves all attributes starting with a lower-case letter. That is, in the future, GDB may add a new method or attribute to the pretty-printer protocol, and `gdb.ValuePrinter'-based printers are expected to handle this gracefully. A simple way to do this would be to use a leading underscore (or two, following the Python name-mangling scheme) to any attributes local to the implementation. -- Function: pretty_printer.children (self) GDB will call this method on a pretty-printer to compute the children of the pretty-printer's value. This method must return an object conforming to the Python iterator protocol. Each item returned by the iterator must be a tuple holding two elements. The first element is the "name" of the child; the second element is the child's value. The value can be any Python object which is convertible to a GDB value. This is a basic method, and is optional. If it does not exist, GDB will act as though the value has no children. For efficiency, the `children' method should lazily compute its results. This will let GDB read as few elements as necessary, for example when various print settings (*note Print Settings::) or `-var-list-children' (*note GDB/MI Variable Objects::) limit the number of elements to be displayed. Children may be hidden from display based on the value of `set print max-depth' (*note Print Settings::). -- Function: pretty_printer.display_hint (self) The CLI may call this method and use its result to change the formatting of a value. The result will also be supplied to an MI consumer as a `displayhint' attribute of the variable being printed. This is a basic method, and is optional. If it does exist, this method must return a string or the special value `None'. Some display hints are predefined by GDB: `array' Indicate that the object being printed is "array-like". The CLI uses this to respect parameters such as `set print elements' and `set print array'. `map' Indicate that the object being printed is "map-like", and that the children of this value can be assumed to alternate between keys and values. `string' Indicate that the object being printed is "string-like". If the printer's `to_string' method returns a Python string of some kind, then GDB will call its internal language-specific string-printing function to format the string. For the CLI this means adding quotation marks, possibly escaping some characters, respecting `set print elements', and the like. The special value `None' causes GDB to apply the default display rules. -- Function: pretty_printer.to_string (self) GDB will call this method to display the string representation of the value passed to the object's constructor. This is a basic method, and is optional. When printing from the CLI, if the `to_string' method exists, then GDB will prepend its result to the values returned by `children'. Exactly how this formatting is done is dependent on the display hint, and may change as more hints are added. Also, depending on the print settings (*note Print Settings::), the CLI may print just the result of `to_string' in a stack trace, omitting the result of `children'. If this method returns a string, it is printed verbatim. Otherwise, if this method returns an instance of `gdb.Value', then GDB prints this value. This may result in a call to another pretty-printer. If instead the method returns a Python value which is convertible to a `gdb.Value', then GDB performs the conversion and prints the resulting value. Again, this may result in a call to another pretty-printer. Python scalars (integers, floats, and booleans) and strings are convertible to `gdb.Value'; other types are not. Finally, if this method returns `None' then no further operations are performed in this method and nothing is printed. If the result is not one of these types, an exception is raised. -- Function: pretty_printer.num_children () This is not a basic method, so GDB will only ever call it for objects derived from `gdb.ValuePrinter'. If available, this method should return the number of children. `None' may be returned if the number can't readily be computed. -- Function: pretty_printer.child (n) This is not a basic method, so GDB will only ever call it for objects derived from `gdb.ValuePrinter'. If available, this method should return the child item (that is, a tuple holding the name and value of this child) indicated by N. Indices start at zero. GDB provides a function which can be used to look up the default pretty-printer for a `gdb.Value': -- Function: gdb.default_visualizer (value) This function takes a `gdb.Value' object as an argument. If a pretty-printer for this value exists, then it is returned. If no such printer exists, then this returns `None'. Normally, a pretty-printer can respect the user's print settings (including temporarily applied settings, such as `/x') simply by calling `Value.format_string' (*note Values From Inferior::). However, these settings can also be queried directly: -- Function: gdb.print_options () Return a dictionary whose keys are the valid keywords that can be given to `Value.format_string', and whose values are the user's settings. During a `print' or other operation, the values will reflect any flags that are temporarily in effect. (gdb) python print (gdb.print_options ()['max_elements']) 200  File: gdb.info, Node: Selecting Pretty-Printers, Next: Writing a Pretty-Printer, Prev: Pretty Printing API, Up: Python API 23.3.2.7 Selecting Pretty-Printers .................................. GDB provides several ways to register a pretty-printer: globally, per program space, and per objfile. When choosing how to register your pretty-printer, a good rule is to register it with the smallest scope possible: that is prefer a specific objfile first, then a program space, and only register a printer globally as a last resort. -- Variable: gdb.pretty_printers The Python list `gdb.pretty_printers' contains an array of functions or callable objects that have been registered via addition as a pretty-printer. Printers in this list are called `global' printers, they're available when debugging all inferiors. Each `gdb.Progspace' contains a `pretty_printers' attribute. Each `gdb.Objfile' also contains a `pretty_printers' attribute. Each function on these lists is passed a single `gdb.Value' argument and should return a pretty-printer object conforming to the interface definition above (*note Pretty Printing API::). If a function cannot create a pretty-printer for the value, it should return `None'. GDB first checks the `pretty_printers' attribute of each `gdb.Objfile' in the current program space and iteratively calls each enabled lookup routine in the list for that `gdb.Objfile' until it receives a pretty-printer object. If no pretty-printer is found in the objfile lists, GDB then searches the pretty-printer list of the current program space, calling each enabled function until an object is returned. After these lists have been exhausted, it tries the global `gdb.pretty_printers' list, again calling each enabled function until an object is returned. The order in which the objfiles are searched is not specified. For a given list, functions are always invoked from the head of the list, and iterated over sequentially until the end of the list, or a printer object is returned. For various reasons a pretty-printer may not work. For example, the underlying data structure may have changed and the pretty-printer is out of date. The consequences of a broken pretty-printer are severe enough that GDB provides support for enabling and disabling individual printers. For example, if `print frame-arguments' is on, a backtrace can become highly illegible if any argument is printed with a broken printer. Pretty-printers are enabled and disabled by attaching an `enabled' attribute to the registered function or callable object. If this attribute is present and its value is `False', the printer is disabled, otherwise the printer is enabled.  File: gdb.info, Node: Writing a Pretty-Printer, Next: Type Printing API, Prev: Selecting Pretty-Printers, Up: Python API 23.3.2.8 Writing a Pretty-Printer ................................. A pretty-printer consists of two parts: a lookup function to detect if the type is supported, and the printer itself. Here is an example showing how a `std::string' printer might be written. *Note Pretty Printing API::, for details on the API this class must provide. Note that this example uses the `gdb.ValuePrinter' base class, and is careful to use a leading underscore for its local state. class StdStringPrinter(gdb.ValuePrinter): "Print a std::string" def __init__(self, val): self.__val = val def to_string(self): return self.__val['_M_dataplus']['_M_p'] def display_hint(self): return 'string' And here is an example showing how a lookup function for the printer example above might be written. def str_lookup_function(val): lookup_tag = val.type.tag if lookup_tag is None: return None regex = re.compile("^std::basic_string$") if regex.match(lookup_tag): return StdStringPrinter(val) return None The example lookup function extracts the value's type, and attempts to match it to a type that it can pretty-print. If it is a type the printer can pretty-print, it will return a printer object. If not, it returns `None'. We recommend that you put your core pretty-printers into a Python package. If your pretty-printers are for use with a library, we further recommend embedding a version number into the package name. This practice will enable GDB to load multiple versions of your pretty-printers at the same time, because they will have different names. You should write auto-loaded code (*note Python Auto-loading::) such that it can be evaluated multiple times without changing its meaning. An ideal auto-load file will consist solely of `import's of your printer modules, followed by a call to a register pretty-printers with the current objfile. Taken as a whole, this approach will scale nicely to multiple inferiors, each potentially using a different library version. Embedding a version number in the Python package name will ensure that GDB is able to load both sets of printers simultaneously. Then, because the search for pretty-printers is done by objfile, and because your auto-loaded code took care to register your library's printers with a specific objfile, GDB will find the correct printers for the specific version of the library used by each inferior. To continue the `std::string' example (*note Pretty Printing API::), this code might appear in `gdb.libstdcxx.v6': def register_printers(objfile): objfile.pretty_printers.append(str_lookup_function) And then the corresponding contents of the auto-load file would be: import gdb.libstdcxx.v6 gdb.libstdcxx.v6.register_printers(gdb.current_objfile()) The previous example illustrates a basic pretty-printer. There are a few things that can be improved on. The printer doesn't have a name, making it hard to identify in a list of installed printers. The lookup function has a name, but lookup functions can have arbitrary, even identical, names. Second, the printer only handles one type, whereas a library typically has several types. One could install a lookup function for each desired type in the library, but one could also have a single lookup function recognize several types. The latter is the conventional way this is handled. If a pretty-printer can handle multiple data types, then its "subprinters" are the printers for the individual data types. The `gdb.printing' module provides a formal way of solving these problems (*note gdb.printing::). Here is another example that handles multiple types. These are the types we are going to pretty-print: struct foo { int a, b; }; struct bar { struct foo x, y; }; Here are the printers: class fooPrinter(gdb.ValuePrinter): """Print a foo object.""" def __init__(self, val): self.__val = val def to_string(self): return ("a=<" + str(self.__val["a"]) + "> b=<" + str(self.__val["b"]) + ">") class barPrinter(gdb.ValuePrinter): """Print a bar object.""" def __init__(self, val): self.__val = val def to_string(self): return ("x=<" + str(self.__val["x"]) + "> y=<" + str(self.__val["y"]) + ">") This example doesn't need a lookup function, that is handled by the `gdb.printing' module. Instead a function is provided to build up the object that handles the lookup. import gdb.printing def build_pretty_printer(): pp = gdb.printing.RegexpCollectionPrettyPrinter( "my_library") pp.add_printer('foo', '^foo$', fooPrinter) pp.add_printer('bar', '^bar$', barPrinter) return pp And here is the autoload support: import gdb.printing import my_library gdb.printing.register_pretty_printer( gdb.current_objfile(), my_library.build_pretty_printer()) Finally, when this printer is loaded into GDB, here is the corresponding output of `info pretty-printer': (gdb) info pretty-printer my_library.so: my_library foo bar  File: gdb.info, Node: Type Printing API, Next: Frame Filter API, Prev: Writing a Pretty-Printer, Up: Python API 23.3.2.9 Type Printing API .......................... GDB provides a way for Python code to customize type display. This is mainly useful for substituting canonical typedef names for types. A "type printer" is just a Python object conforming to a certain protocol. A simple base class implementing the protocol is provided; see *Note gdb.types::. A type printer must supply at least: -- Instance Variable of type_printer: enabled A boolean which is True if the printer is enabled, and False otherwise. This is manipulated by the `enable type-printer' and `disable type-printer' commands. -- Instance Variable of type_printer: name The name of the type printer. This must be a string. This is used by the `enable type-printer' and `disable type-printer' commands. -- Method on type_printer: instantiate (self) This is called by GDB at the start of type-printing. It is only called if the type printer is enabled. This method must return a new object that supplies a `recognize' method, as described below. When displaying a type, say via the `ptype' command, GDB will compute a list of type recognizers. This is done by iterating first over the per-objfile type printers (*note Objfiles In Python::), followed by the per-progspace type printers (*note Progspaces In Python::), and finally the global type printers. GDB will call the `instantiate' method of each enabled type printer. If this method returns `None', then the result is ignored; otherwise, it is appended to the list of recognizers. Then, when GDB is going to display a type name, it iterates over the list of recognizers. For each one, it calls the recognition function, stopping if the function returns a non-`None' value. The recognition function is defined as: -- Method on type_recognizer: recognize (self, type) If TYPE is not recognized, return `None'. Otherwise, return a string which is to be printed as the name of TYPE. The TYPE argument will be an instance of `gdb.Type' (*note Types In Python::). GDB uses this two-pass approach so that type printers can efficiently cache information without holding on to it too long. For example, it can be convenient to look up type information in a type printer and hold it for a recognizer's lifetime; if a single pass were done then type printers would have to make use of the event system in order to avoid holding information that could become stale as the inferior changed.  File: gdb.info, Node: Frame Filter API, Next: Frame Decorator API, Prev: Type Printing API, Up: Python API 23.3.2.10 Filtering Frames .......................... Frame filters are Python objects that manipulate the visibility of a frame or frames when a backtrace (*note Backtrace::) is printed by GDB. Only commands that print a backtrace, or, in the case of GDB/MI commands (*note GDB/MI::), those that return a collection of frames are affected. The commands that work with frame filters are: `backtrace' (*note The backtrace command: backtrace-command.), `-stack-list-frames' (*note The -stack-list-frames command: -stack-list-frames.), `-stack-list-variables' (*note The -stack-list-variables command: -stack-list-variables.), `-stack-list-arguments' *note The -stack-list-arguments command: -stack-list-arguments.) and `-stack-list-locals' (*note The -stack-list-locals command: -stack-list-locals.). A frame filter works by taking an iterator as an argument, applying actions to the contents of that iterator, and returning another iterator (or, possibly, the same iterator it was provided in the case where the filter does not perform any operations). Typically, frame filters utilize tools such as the Python's `itertools' module to work with and create new iterators from the source iterator. Regardless of how a filter chooses to apply actions, it must not alter the underlying GDB frame or frames, or attempt to alter the call-stack within GDB. This preserves data integrity within GDB. Frame filters are executed on a priority basis and care should be taken that some frame filters may have been executed before, and that some frame filters will be executed after. An important consideration when designing frame filters, and well worth reflecting upon, is that frame filters should avoid unwinding the call stack if possible. Some stacks can run very deep, into the tens of thousands in some cases. To search every frame when a frame filter executes may be too expensive at that step. The frame filter cannot know how many frames it has to iterate over, and it may have to iterate through them all. This ends up duplicating effort as GDB performs this iteration when it prints the frames. If the filter can defer unwinding frames until frame decorators are executed, after the last filter has executed, it should. *Note Frame Decorator API::, for more information on decorators. Also, there are examples for both frame decorators and filters in later chapters. *Note Writing a Frame Filter::, for more information. The Python dictionary `gdb.frame_filters' contains key/object pairings that comprise a frame filter. Frame filters in this dictionary are called `global' frame filters, and they are available when debugging all inferiors. These frame filters must register with the dictionary directly. In addition to the `global' dictionary, there are other dictionaries that are loaded with different inferiors via auto-loading (*note Python Auto-loading::). The two other areas where frame filter dictionaries can be found are: `gdb.Progspace' which contains a `frame_filters' dictionary attribute, and each `gdb.Objfile' object which also contains a `frame_filters' dictionary attribute. When a command is executed from GDB that is compatible with frame filters, GDB combines the `global', `gdb.Progspace' and all `gdb.Objfile' dictionaries currently loaded. All of the `gdb.Objfile' dictionaries are combined, as several frames, and thus several object files, might be in use. GDB then prunes any frame filter whose `enabled' attribute is `False'. This pruned list is then sorted according to the `priority' attribute in each filter. Once the dictionaries are combined, pruned and sorted, GDB creates an iterator which wraps each frame in the call stack in a `FrameDecorator' object, and calls each filter in order. The output from the previous filter will always be the input to the next filter, and so on. Frame filters have a mandatory interface which each frame filter must implement, defined here: -- Function: FrameFilter.filter (iterator) GDB will call this method on a frame filter when it has reached the order in the priority list for that filter. For example, if there are four frame filters: Name Priority Filter1 5 Filter2 10 Filter3 100 Filter4 1 The order that the frame filters will be called is: Filter3 -> Filter2 -> Filter1 -> Filter4 Note that the output from `Filter3' is passed to the input of `Filter2', and so on. This `filter' method is passed a Python iterator. This iterator contains a sequence of frame decorators that wrap each `gdb.Frame', or a frame decorator that wraps another frame decorator. The first filter that is executed in the sequence of frame filters will receive an iterator entirely comprised of default `FrameDecorator' objects. However, after each frame filter is executed, the previous frame filter may have wrapped some or all of the frame decorators with their own frame decorator. As frame decorators must also conform to a mandatory interface, these decorators can be assumed to act in a uniform manner (*note Frame Decorator API::). This method must return an object conforming to the Python iterator protocol. Each item in the iterator must be an object conforming to the frame decorator interface. If a frame filter does not wish to perform any operations on this iterator, it should return that iterator untouched. This method is not optional. If it does not exist, GDB will raise and print an error. -- Variable: FrameFilter.name The `name' attribute must be Python string which contains the name of the filter displayed by GDB (*note Frame Filter Management::). This attribute may contain any combination of letters or numbers. Care should be taken to ensure that it is unique. This attribute is mandatory. -- Variable: FrameFilter.enabled The `enabled' attribute must be Python boolean. This attribute indicates to GDB whether the frame filter is enabled, and should be considered when frame filters are executed. If `enabled' is `True', then the frame filter will be executed when any of the backtrace commands detailed earlier in this chapter are executed. If `enabled' is `False', then the frame filter will not be executed. This attribute is mandatory. -- Variable: FrameFilter.priority The `priority' attribute must be Python integer. This attribute controls the order of execution in relation to other frame filters. There are no imposed limits on the range of `priority' other than it must be a valid integer. The higher the `priority' attribute, the sooner the frame filter will be executed in relation to other frame filters. Although `priority' can be negative, it is recommended practice to assume zero is the lowest priority that a frame filter can be assigned. Frame filters that have the same priority are executed in unsorted order in that priority slot. This attribute is mandatory. 100 is a good default priority.  File: gdb.info, Node: Frame Decorator API, Next: Writing a Frame Filter, Prev: Frame Filter API, Up: Python API 23.3.2.11 Decorating Frames ........................... Frame decorators are sister objects to frame filters (*note Frame Filter API::). Frame decorators are applied by a frame filter and can only be used in conjunction with frame filters. The purpose of a frame decorator is to customize the printed content of each `gdb.Frame' in commands where frame filters are executed. This concept is called decorating a frame. Frame decorators decorate a `gdb.Frame' with Python code contained within each API call. This separates the actual data contained in a `gdb.Frame' from the decorated data produced by a frame decorator. This abstraction is necessary to maintain integrity of the data contained in each `gdb.Frame'. Frame decorators have a mandatory interface, defined below. GDB already contains a frame decorator called `FrameDecorator'. This contains substantial amounts of boilerplate code to decorate the content of a `gdb.Frame'. It is recommended that other frame decorators inherit and extend this object, and only to override the methods needed. `FrameDecorator' is defined in the Python module `gdb.FrameDecorator', so your code can import it like: from gdb.FrameDecorator import FrameDecorator -- Function: FrameDecorator.elided (self) The `elided' method groups frames together in a hierarchical system. An example would be an interpreter, where multiple low-level frames make up a single call in the interpreted language. In this example, the frame filter would elide the low-level frames and present a single high-level frame, representing the call in the interpreted language, to the user. The `elided' function must return an iterable and this iterable must contain the frames that are being elided wrapped in a suitable frame decorator. If no frames are being elided this function may return an empty iterable, or `None'. Elided frames are indented from normal frames in a `CLI' backtrace, or in the case of GDB/MI, are placed in the `children' field of the eliding frame. It is the frame filter's task to also filter out the elided frames from the source iterator. This will avoid printing the frame twice. -- Function: FrameDecorator.function (self) This method returns the name of the function in the frame that is to be printed. This method must return a Python string describing the function, or `None'. If this function returns `None', GDB will not print any data for this field. -- Function: FrameDecorator.address (self) This method returns the address of the frame that is to be printed. This method must return a Python numeric integer type of sufficient size to describe the address of the frame, or `None'. If this function returns a `None', GDB will not print any data for this field. -- Function: FrameDecorator.filename (self) This method returns the filename and path associated with this frame. This method must return a Python string containing the filename and the path to the object file backing the frame, or `None'. If this function returns a `None', GDB will not print any data for this field. -- Function: FrameDecorator.line (self): This method returns the line number associated with the current position within the function addressed by this frame. This method must return a Python integer type, or `None'. If this function returns a `None', GDB will not print any data for this field. -- Function: FrameDecorator.frame_args (self) This method must return an iterable, or `None'. Returning an empty iterable, or `None' means frame arguments will not be printed for this frame. This iterable must contain objects that implement two methods, described here. This object must implement a `symbol' method which takes a single `self' parameter and must return a `gdb.Symbol' (*note Symbols In Python::), or a Python string. The object must also implement a `value' method which takes a single `self' parameter and must return a `gdb.Value' (*note Values From Inferior::), a Python value, or `None'. If the `value' method returns `None', and the `argument' method returns a `gdb.Symbol', GDB will look-up and print the value of the `gdb.Symbol' automatically. A brief example: class SymValueWrapper(): def __init__(self, symbol, value): self.sym = symbol self.val = value def value(self): return self.val def symbol(self): return self.sym class SomeFrameDecorator() ... ... def frame_args(self): args = [] try: block = self.inferior_frame.block() except: return None # Iterate over all symbols in a block. Only add # symbols that are arguments. for sym in block: if not sym.is_argument: continue args.append(SymValueWrapper(sym,None)) # Add example synthetic argument. args.append(SymValueWrapper(``foo'', 42)) return args -- Function: FrameDecorator.frame_locals (self) This method must return an iterable or `None'. Returning an empty iterable, or `None' means frame local arguments will not be printed for this frame. The object interface, the description of the various strategies for reading frame locals, and the example are largely similar to those described in the `frame_args' function, (*note The frame filter frame_args function: frame_args.). Below is a modified example: class SomeFrameDecorator() ... ... def frame_locals(self): vars = [] try: block = self.inferior_frame.block() except: return None # Iterate over all symbols in a block. Add all # symbols, except arguments. for sym in block: if sym.is_argument: continue vars.append(SymValueWrapper(sym,None)) # Add an example of a synthetic local variable. vars.append(SymValueWrapper(``bar'', 99)) return vars -- Function: FrameDecorator.inferior_frame (self): This method must return the underlying `gdb.Frame' that this frame decorator is decorating. GDB requires the underlying frame for internal frame information to determine how to print certain values when printing a frame.  File: gdb.info, Node: Writing a Frame Filter, Next: Unwinding Frames in Python, Prev: Frame Decorator API, Up: Python API 23.3.2.12 Writing a Frame Filter ................................ There are three basic elements that a frame filter must implement: it must correctly implement the documented interface (*note Frame Filter API::), it must register itself with GDB, and finally, it must decide if it is to work on the data provided by GDB. In all cases, whether it works on the iterator or not, each frame filter must return an iterator. A bare-bones frame filter follows the pattern in the following example. import gdb class FrameFilter(): def __init__(self): # Frame filter attribute creation. # # 'name' is the name of the filter that GDB will display. # # 'priority' is the priority of the filter relative to other # filters. # # 'enabled' is a boolean that indicates whether this filter is # enabled and should be executed. self.name = "Foo" self.priority = 100 self.enabled = True # Register this frame filter with the global frame_filters # dictionary. gdb.frame_filters[self.name] = self def filter(self, frame_iter): # Just return the iterator. return frame_iter The frame filter in the example above implements the three requirements for all frame filters. It implements the API, self registers, and makes a decision on the iterator (in this case, it just returns the iterator untouched). The first step is attribute creation and assignment, and as shown in the comments the filter assigns the following attributes: `name', `priority' and whether the filter should be enabled with the `enabled' attribute. The second step is registering the frame filter with the dictionary or dictionaries that the frame filter has interest in. As shown in the comments, this filter just registers itself with the global dictionary `gdb.frame_filters'. As noted earlier, `gdb.frame_filters' is a dictionary that is initialized in the `gdb' module when GDB starts. What dictionary a filter registers with is an important consideration. Generally, if a filter is specific to a set of code, it should be registered either in the `objfile' or `progspace' dictionaries as they are specific to the program currently loaded in GDB. The global dictionary is always present in GDB and is never unloaded. Any filters registered with the global dictionary will exist until GDB exits. To avoid filters that may conflict, it is generally better to register frame filters against the dictionaries that more closely align with the usage of the filter currently in question. *Note Python Auto-loading::, for further information on auto-loading Python scripts. GDB takes a hands-off approach to frame filter registration, therefore it is the frame filter's responsibility to ensure registration has occurred, and that any exceptions are handled appropriately. In particular, you may wish to handle exceptions relating to Python dictionary key uniqueness. It is mandatory that the dictionary key is the same as frame filter's `name' attribute. When a user manages frame filters (*note Frame Filter Management::), the names GDB will display are those contained in the `name' attribute. The final step of this example is the implementation of the `filter' method. As shown in the example comments, we define the `filter' method and note that the method must take an iterator, and also must return an iterator. In this bare-bones example, the frame filter is not very useful as it just returns the iterator untouched. However this is a valid operation for frame filters that have the `enabled' attribute set, but decide not to operate on any frames. In the next example, the frame filter operates on all frames and utilizes a frame decorator to perform some work on the frames. *Note Frame Decorator API::, for further information on the frame decorator interface. This example works on inlined frames. It highlights frames which are inlined by tagging them with an "[inlined]" tag. By applying a frame decorator to all frames with the Python `itertools imap' method, the example defers actions to the frame decorator. Frame decorators are only processed when GDB prints the backtrace. This introduces a new decision making topic: whether to perform decision making operations at the filtering step, or at the printing step. In this example's approach, it does not perform any filtering decisions at the filtering step beyond mapping a frame decorator to each frame. This allows the actual decision making to be performed when each frame is printed. This is an important consideration, and well worth reflecting upon when designing a frame filter. An issue that frame filters should avoid is unwinding the stack if possible. Some stacks can run very deep, into the tens of thousands in some cases. To search every frame to determine if it is inlined ahead of time may be too expensive at the filtering step. The frame filter cannot know how many frames it has to iterate over, and it would have to iterate through them all. This ends up duplicating effort as GDB performs this iteration when it prints the frames. In this example decision making can be deferred to the printing step. As each frame is printed, the frame decorator can examine each frame in turn when GDB iterates. From a performance viewpoint, this is the most appropriate decision to make as it avoids duplicating the effort that the printing step would undertake anyway. Also, if there are many frame filters unwinding the stack during filtering, it can substantially delay the printing of the backtrace which will result in large memory usage, and a poor user experience. class InlineFilter(): def __init__(self): self.name = "InlinedFrameFilter" self.priority = 100 self.enabled = True gdb.frame_filters[self.name] = self def filter(self, frame_iter): frame_iter = itertools.imap(InlinedFrameDecorator, frame_iter) return frame_iter This frame filter is somewhat similar to the earlier example, except that the `filter' method applies a frame decorator object called `InlinedFrameDecorator' to each element in the iterator. The `imap' Python method is light-weight. It does not proactively iterate over the iterator, but rather creates a new iterator which wraps the existing one. Below is the frame decorator for this example. class InlinedFrameDecorator(FrameDecorator): def __init__(self, fobj): super(InlinedFrameDecorator, self).__init__(fobj) def function(self): frame = self.inferior_frame() name = str(frame.name()) if frame.type() == gdb.INLINE_FRAME: name = name + " [inlined]" return name This frame decorator only defines and overrides the `function' method. It lets the supplied `FrameDecorator', which is shipped with GDB, perform the other work associated with printing this frame. The combination of these two objects create this output from a backtrace: #0 0x004004e0 in bar () at inline.c:11 #1 0x00400566 in max [inlined] (b=6, a=12) at inline.c:21 #2 0x00400566 in main () at inline.c:31 So in the case of this example, a frame decorator is applied to all frames, regardless of whether they may be inlined or not. As GDB iterates over the iterator produced by the frame filters, GDB executes each frame decorator which then makes a decision on what to print in the `function' callback. Using a strategy like this is a way to defer decisions on the frame content to printing time. Eliding Frames -------------- It might be that the above example is not desirable for representing inlined frames, and a hierarchical approach may be preferred. If we want to hierarchically represent frames, the `elided' frame decorator interface might be preferable. This example approaches the issue with the `elided' method. This example is quite long, but very simplistic. It is out-of-scope for this section to write a complete example that comprehensively covers all approaches of finding and printing inlined frames. However, this example illustrates the approach an author might use. This example comprises of three sections. class InlineFrameFilter(): def __init__(self): self.name = "InlinedFrameFilter" self.priority = 100 self.enabled = True gdb.frame_filters[self.name] = self def filter(self, frame_iter): return ElidingInlineIterator(frame_iter) This frame filter is very similar to the other examples. The only difference is this frame filter is wrapping the iterator provided to it (`frame_iter') with a custom iterator called `ElidingInlineIterator'. This again defers actions to when GDB prints the backtrace, as the iterator is not traversed until printing. The iterator for this example is as follows. It is in this section of the example where decisions are made on the content of the backtrace. class ElidingInlineIterator: def __init__(self, ii): self.input_iterator = ii def __iter__(self): return self def next(self): frame = next(self.input_iterator) if frame.inferior_frame().type() != gdb.INLINE_FRAME: return frame try: eliding_frame = next(self.input_iterator) except StopIteration: return frame return ElidingFrameDecorator(eliding_frame, [frame]) This iterator implements the Python iterator protocol. When the `next' function is called (when GDB prints each frame), the iterator checks if this frame decorator, `frame', is wrapping an inlined frame. If it is not, it returns the existing frame decorator untouched. If it is wrapping an inlined frame, it assumes that the inlined frame was contained within the next oldest frame, `eliding_frame', which it fetches. It then creates and returns a frame decorator, `ElidingFrameDecorator', which contains both the elided frame, and the eliding frame. class ElidingInlineDecorator(FrameDecorator): def __init__(self, frame, elided_frames): super(ElidingInlineDecorator, self).__init__(frame) self.frame = frame self.elided_frames = elided_frames def elided(self): return iter(self.elided_frames) This frame decorator overrides one function and returns the inlined frame in the `elided' method. As before it lets `FrameDecorator' do the rest of the work involved in printing this frame. This produces the following output. #0 0x004004e0 in bar () at inline.c:11 #2 0x00400529 in main () at inline.c:25 #1 0x00400529 in max (b=6, a=12) at inline.c:15 In that output, `max' which has been inlined into `main' is printed hierarchically. Another approach would be to combine the `function' method, and the `elided' method to both print a marker in the inlined frame, and also show the hierarchical relationship.  File: gdb.info, Node: Unwinding Frames in Python, Next: Xmethods In Python, Prev: Writing a Frame Filter, Up: Python API 23.3.2.13 Unwinding Frames in Python .................................... In GDB terminology "unwinding" is the process of finding the previous frame (that is, caller's) from the current one. An unwinder has three methods. The first one checks if it can handle given frame ("sniff" it). For the frames it can sniff an unwinder provides two additional methods: it can return frame's ID, and it can fetch registers from the previous frame. A running GDB maintains a list of the unwinders and calls each unwinder's sniffer in turn until it finds the one that recognizes the current frame. There is an API to register an unwinder. The unwinders that come with GDB handle standard frames. However, mixed language applications (for example, an application running Java Virtual Machine) sometimes use frame layouts that cannot be handled by the GDB unwinders. You can write Python code that can handle such custom frames. You implement a frame unwinder in Python as a class with which has two attributes, `name' and `enabled', with obvious meanings, and a single method `__call__', which examines a given frame and returns an object (an instance of `gdb.UnwindInfo class)' describing it. If an unwinder does not recognize a frame, it should return `None'. The code in GDB that enables writing unwinders in Python uses this object to return frame's ID and previous frame registers when GDB core asks for them. An unwinder should do as little work as possible. Some otherwise innocuous operations can cause problems (even crashes, as this code is not well-hardened yet). For example, making an inferior call from an unwinder is unadvisable, as an inferior call will reset GDB's stack unwinding process, potentially causing re-entrant unwinding. Unwinder Input -------------- An object passed to an unwinder (a `gdb.PendingFrame' instance) provides a method to read frame's registers: -- Function: PendingFrame.read_register (register) This method returns the contents of REGISTER in the frame as a `gdb.Value' object. For a description of the acceptable values of REGISTER see *Note Frame.read_register: gdbpy_frame_read_register. If REGISTER does not name a register for the current architecture, this method will throw an exception. Note that this method will always return a `gdb.Value' for a valid register name. This does not mean that the value will be valid. For example, you may request a register that an earlier unwinder could not unwind--the value will be unavailable. Instead, the `gdb.Value' returned from this method will be lazy; that is, its underlying bits will not be fetched until it is first used. So, attempting to use such a value will cause an exception at the point of use. The type of the returned `gdb.Value' depends on the register and the architecture. It is common for registers to have a scalar type, like `long long'; but many other types are possible, such as pointer, pointer-to-function, floating point or vector types. It also provides a factory method to create a `gdb.UnwindInfo' instance to be returned to GDB: -- Function: PendingFrame.create_unwind_info (frame_id) Returns a new `gdb.UnwindInfo' instance identified by given FRAME_ID. The FRAME_ID is used internally by GDB to identify the frames within the current thread's stack. The attributes of FRAME_ID determine what type of frame is created within GDB: `sp, pc' The frame is identified by the given stack address and PC. The stack address must be chosen so that it is constant throughout the lifetime of the frame, so a typical choice is the value of the stack pointer at the start of the function--in the DWARF standard, this would be the "Call Frame Address". This is the most common case by far. The other cases are documented for completeness but are only useful in specialized situations. `sp, pc, special' The frame is identified by the stack address, the PC, and a "special" address. The special address is used on architectures that can have frames that do not change the stack, but which are still distinct, for example the IA-64, which has a second stack for registers. Both SP and SPECIAL must be constant throughout the lifetime of the frame. `sp' The frame is identified by the stack address only. Any other stack frame with a matching SP will be considered to match this frame. Inside gdb, this is called a "wild frame". You will never need this. Each attribute value should either be an instance of `gdb.Value' or an integer. A helper class is provided in the `gdb.unwinder' module that can be used to represent a frame-id (*note gdb.unwinder.FrameId::). -- Function: PendingFrame.architecture () Return the `gdb.Architecture' (*note Architectures In Python::) for this `gdb.PendingFrame'. This represents the architecture of the particular frame being unwound. -- Function: PendingFrame.level () Return an integer, the stack frame level for this frame. *Note Stack Frames: Frames. -- Function: PendingFrame.name () Returns the function name of this pending frame, or `None' if it can't be obtained. -- Function: PendingFrame.is_valid () Returns true if the `gdb.PendingFrame' object is valid, false if not. A pending frame object becomes invalid when the call to the unwinder, for which the pending frame was created, returns. All `gdb.PendingFrame' methods, except this one, will raise an exception if the pending frame object is invalid at the time the method is called. -- Function: PendingFrame.pc () Returns the pending frame's resume address. -- Function: PendingFrame.block () Return the pending frame's code block (*note Blocks In Python::). If the frame does not have a block - for example, if there is no debugging information for the code in question - then this will raise a `RuntimeError' exception. -- Function: PendingFrame.function () Return the symbol for the function corresponding to this pending frame. *Note Symbols In Python::. -- Function: PendingFrame.find_sal () Return the pending frame's symtab and line object (*note Symbol Tables In Python::). -- Function: PendingFrame.language () Return the language of this frame, as a string, or None. Unwinder Output: UnwindInfo --------------------------- Use `PendingFrame.create_unwind_info' method described above to create a `gdb.UnwindInfo' instance. Use the following method to specify caller registers that have been saved in this frame: -- Function: gdb.UnwindInfo.add_saved_register (register, value) REGISTER identifies the register, for a description of the acceptable values see *Note Frame.read_register: gdbpy_frame_read_register. VALUE is a register value (a `gdb.Value' object). The `gdb.unwinder' Module ------------------------- GDB comes with a `gdb.unwinder' module which contains the following classes: -- class: gdb.unwinder.Unwinder The `Unwinder' class is a base class from which user created unwinders can derive, though it is not required that unwinders derive from this class, so long as any user created unwinder has the required `name' and `enabled' attributes. -- Function: gdb.unwinder.Unwinder.__init__(name) The NAME is a string used to reference this unwinder within some GDB commands (*note Managing Registered Unwinders::). -- Variable: gdb.unwinder.name A read-only attribute which is a string, the name of this unwinder. -- Variable: gdb.unwinder.enabled A modifiable attribute containing a boolean; when `True', the unwinder is enabled, and will be used by GDB. When `False', the unwinder has been disabled, and will not be used. -- class: gdb.unwinder.FrameId This is a class suitable for being used as the frame-id when calling `gdb.PendingFrame.create_unwind_info'. It is not required to use this class, any class with the required attribute (*note gdb.PendingFrame.create_unwind_info::) will be accepted, but in most cases this class will be sufficient. `gdb.unwinder.FrameId' has the following method: -- Function: gdb.unwinder.FrameId.__init__(sp, pc, special = `None') The SP and PC arguments are required and should be either a `gdb.Value' object, or an integer. The SPECIAL argument is optional; if specified, it should be a `gdb.Value' object, or an integer. `gdb.unwinder.FrameId' has the following read-only attributes: -- Variable: gdb.unwinder.sp The SP value passed to the constructor. -- Variable: gdb.unwinder.pc The PC value passed to the constructor. -- Variable: gdb.unwinder.special The SPECIAL value passed to the constructor, or `None' if no such value was passed. Registering an Unwinder ----------------------- Object files and program spaces can have unwinders registered with them. In addition, you can register unwinders globally. The `gdb.unwinders' module provides the function to register an unwinder: -- Function: gdb.unwinder.register_unwinder (locus, unwinder, replace=False) LOCUS specifies to which unwinder list to prepend the UNWINDER. It can be either an object file (*note Objfiles In Python::), a program space (*note Progspaces In Python::), or `None', in which case the unwinder is registered globally. The newly added UNWINDER will be called before any other unwinder from the same locus. Two unwinders in the same locus cannot have the same name. An attempt to add an unwinder with an already existing name raises an exception unless REPLACE is `True', in which case the old unwinder is deleted and the new unwinder is registered in its place. GDB first calls the unwinders from all the object files in no particular order, then the unwinders from the current program space, then the globally registered unwinders, and finally the unwinders builtin to GDB. Unwinder Skeleton Code ---------------------- Here is an example of how to structure a user created unwinder: from gdb.unwinder import Unwinder, FrameId class MyUnwinder(Unwinder): def __init__(self): super().__init___("MyUnwinder_Name") def __call__(self, pending_frame): if not : return None # Create a FrameID. Usually the frame is identified by a # stack pointer and the function address. sp = ... compute a stack address ... pc = ... compute function address ... unwind_info = pending_frame.create_unwind_info(FrameId(sp, pc)) # Find the values of the registers in the caller's frame and # save them in the result: unwind_info.add_saved_register(, ) .... # Return the result: return unwind_info gdb.unwinder.register_unwinder(, MyUnwinder(), ) Managing Registered Unwinders ----------------------------- GDB defines 3 commands to manage registered unwinders. These are: `info unwinder [ LOCUS [ NAME-REGEXP ] ]' Lists all registered unwinders. Arguments LOCUS and NAME-REGEXP are both optional and can be used to filter which unwinders are listed. The LOCUS argument should be either `global', `progspace', or the name of an object file. Only unwinders registered for the specified locus will be listed. The NAME-REGEXP is a regular expression used to match against unwinder names. When trying to match against unwinder names that include a string enclose NAME-REGEXP in quotes. `disable unwinder [ LOCUS [ NAME-REGEXP ] ]' The LOCUS and NAME-REGEXP are interpreted as in `info unwinder' above, but instead of listing the matching unwinders, all of the matching unwinders are disabled. The `enabled' field of each matching unwinder is set to `False'. `enable unwinder [ LOCUS [ NAME-REGEXP ] ]' The LOCUS and NAME-REGEXP are interpreted as in `info unwinder' above, but instead of listing the matching unwinders, all of the matching unwinders are enabled. The `enabled' field of each matching unwinder is set to `True'.  File: gdb.info, Node: Xmethods In Python, Next: Xmethod API, Prev: Unwinding Frames in Python, Up: Python API 23.3.2.14 Xmethods In Python ............................ "Xmethods" are additional methods or replacements for existing methods of a C++ class. This feature is useful for those cases where a method defined in C++ source code could be inlined or optimized out by the compiler, making it unavailable to GDB. For such cases, one can define an xmethod to serve as a replacement for the method defined in the C++ source code. GDB will then invoke the xmethod, instead of the C++ method, to evaluate expressions. One can also use xmethods when debugging with core files. Moreover, when debugging live programs, invoking an xmethod need not involve running the inferior (which can potentially perturb its state). Hence, even if the C++ method is available, it is better to use its replacement xmethod if one is defined. The xmethods feature in Python is available via the concepts of an "xmethod matcher" and an "xmethod worker". To implement an xmethod, one has to implement a matcher and a corresponding worker for it (more than one worker can be implemented, each catering to a different overloaded instance of the method). Internally, GDB invokes the `match' method of a matcher to match the class type and method name. On a match, the `match' method returns a list of matching _worker_ objects. Each worker object typically corresponds to an overloaded instance of the xmethod. They implement a `get_arg_types' method which returns a sequence of types corresponding to the arguments the xmethod requires. GDB uses this sequence of types to perform overload resolution and picks a winning xmethod worker. A winner is also selected from among the methods GDB finds in the C++ source code. Next, the winning xmethod worker and the winning C++ method are compared to select an overall winner. In case of a tie between a xmethod worker and a C++ method, the xmethod worker is selected as the winner. That is, if a winning xmethod worker is found to be equivalent to the winning C++ method, then the xmethod worker is treated as a replacement for the C++ method. GDB uses the overall winner to invoke the method. If the winning xmethod worker is the overall winner, then the corresponding xmethod is invoked via the `__call__' method of the worker object. If one wants to implement an xmethod as a replacement for an existing C++ method, then they have to implement an equivalent xmethod which has exactly the same name and takes arguments of exactly the same type as the C++ method. If the user wants to invoke the C++ method even though a replacement xmethod is available for that method, then they can disable the xmethod. *Note Xmethod API::, for API to implement xmethods in Python. *Note Writing an Xmethod::, for implementing xmethods in Python.  File: gdb.info, Node: Xmethod API, Next: Writing an Xmethod, Prev: Xmethods In Python, Up: Python API 23.3.2.15 Xmethod API ..................... The GDB Python API provides classes, interfaces and functions to implement, register and manipulate xmethods. *Note Xmethods In Python::. An xmethod matcher should be an instance of a class derived from `XMethodMatcher' defined in the module `gdb.xmethod', or an object with similar interface and attributes. An instance of `XMethodMatcher' has the following attributes: -- Variable: name The name of the matcher. -- Variable: enabled A boolean value indicating whether the matcher is enabled or disabled. -- Variable: methods A list of named methods managed by the matcher. Each object in the list is an instance of the class `XMethod' defined in the module `gdb.xmethod', or any object with the following attributes: `name' Name of the xmethod which should be unique for each xmethod managed by the matcher. `enabled' A boolean value indicating whether the xmethod is enabled or disabled. The class `XMethod' is a convenience class with same attributes as above along with the following constructor: -- Function: XMethod.__init__ (self, name) Constructs an enabled xmethod with name NAME. The `XMethodMatcher' class has the following methods: -- Function: XMethodMatcher.__init__ (self, name) Constructs an enabled xmethod matcher with name NAME. The `methods' attribute is initialized to `None'. -- Function: XMethodMatcher.match (self, class_type, method_name) Derived classes should override this method. It should return a xmethod worker object (or a sequence of xmethod worker objects) matching the CLASS_TYPE and METHOD_NAME. CLASS_TYPE is a `gdb.Type' object, and METHOD_NAME is a string value. If the matcher manages named methods as listed in its `methods' attribute, then only those worker objects whose corresponding entries in the `methods' list are enabled should be returned. An xmethod worker should be an instance of a class derived from `XMethodWorker' defined in the module `gdb.xmethod', or support the following interface: -- Function: XMethodWorker.get_arg_types (self) This method returns a sequence of `gdb.Type' objects corresponding to the arguments that the xmethod takes. It can return an empty sequence or `None' if the xmethod does not take any arguments. If the xmethod takes a single argument, then a single `gdb.Type' object corresponding to it can be returned. -- Function: XMethodWorker.get_result_type (self, *args) This method returns a `gdb.Type' object representing the type of the result of invoking this xmethod. The ARGS argument is the same tuple of arguments that would be passed to the `__call__' method of this worker. -- Function: XMethodWorker.__call__ (self, *args) This is the method which does the _work_ of the xmethod. The ARGS arguments is the tuple of arguments to the xmethod. Each element in this tuple is a gdb.Value object. The first element is always the `this' pointer value. For GDB to lookup xmethods, the xmethod matchers should be registered using the following function defined in the module `gdb.xmethod': -- Function: register_xmethod_matcher (locus, matcher, replace=False) The `matcher' is registered with `locus', replacing an existing matcher with the same name as `matcher' if `replace' is `True'. `locus' can be a `gdb.Objfile' object (*note Objfiles In Python::), or a `gdb.Progspace' object (*note Progspaces In Python::), or `None'. If it is `None', then `matcher' is registered globally.  File: gdb.info, Node: Writing an Xmethod, Next: Inferiors In Python, Prev: Xmethod API, Up: Python API 23.3.2.16 Writing an Xmethod ............................ Implementing xmethods in Python will require implementing xmethod matchers and xmethod workers (*note Xmethods In Python::). Consider the following C++ class: class MyClass { public: MyClass (int a) : a_(a) { } int geta (void) { return a_; } int operator+ (int b); private: int a_; }; int MyClass::operator+ (int b) { return a_ + b; } Let us define two xmethods for the class `MyClass', one replacing the method `geta', and another adding an overloaded flavor of `operator+' which takes a `MyClass' argument (the C++ code above already has an overloaded `operator+' which takes an `int' argument). The xmethod matcher can be defined as follows: class MyClass_geta(gdb.xmethod.XMethod): def __init__(self): gdb.xmethod.XMethod.__init__(self, 'geta') def get_worker(self, method_name): if method_name == 'geta': return MyClassWorker_geta() class MyClass_sum(gdb.xmethod.XMethod): def __init__(self): gdb.xmethod.XMethod.__init__(self, 'sum') def get_worker(self, method_name): if method_name == 'operator+': return MyClassWorker_plus() class MyClassMatcher(gdb.xmethod.XMethodMatcher): def __init__(self): gdb.xmethod.XMethodMatcher.__init__(self, 'MyClassMatcher') # List of methods 'managed' by this matcher self.methods = [MyClass_geta(), MyClass_sum()] def match(self, class_type, method_name): if class_type.tag != 'MyClass': return None workers = [] for method in self.methods: if method.enabled: worker = method.get_worker(method_name) if worker: workers.append(worker) return workers Notice that the `match' method of `MyClassMatcher' returns a worker object of type `MyClassWorker_geta' for the `geta' method, and a worker object of type `MyClassWorker_plus' for the `operator+' method. This is done indirectly via helper classes derived from `gdb.xmethod.XMethod'. One does not need to use the `methods' attribute in a matcher as it is optional. However, if a matcher manages more than one xmethod, it is a good practice to list the xmethods in the `methods' attribute of the matcher. This will then facilitate enabling and disabling individual xmethods via the `enable/disable' commands. Notice also that a worker object is returned only if the corresponding entry in the `methods' attribute of the matcher is enabled. The implementation of the worker classes returned by the matcher setup above is as follows: class MyClassWorker_geta(gdb.xmethod.XMethodWorker): def get_arg_types(self): return None def get_result_type(self, obj): return gdb.lookup_type('int') def __call__(self, obj): return obj['a_'] class MyClassWorker_plus(gdb.xmethod.XMethodWorker): def get_arg_types(self): return gdb.lookup_type('MyClass') def get_result_type(self, obj): return gdb.lookup_type('int') def __call__(self, obj, other): return obj['a_'] + other['a_'] For GDB to actually lookup a xmethod, it has to be registered with it. The matcher defined above is registered with GDB globally as follows: gdb.xmethod.register_xmethod_matcher(None, MyClassMatcher()) If an object `obj' of type `MyClass' is initialized in C++ code as follows: MyClass obj(5); then, after loading the Python script defining the xmethod matchers and workers into GDB, invoking the method `geta' or using the operator `+' on `obj' will invoke the xmethods defined above: (gdb) p obj.geta() $1 = 5 (gdb) p obj + obj $2 = 10 Consider another example with a C++ template class: template class MyTemplate { public: MyTemplate () : dsize_(10), data_ (new T [10]) { } ~MyTemplate () { delete [] data_; } int footprint (void) { return sizeof (T) * dsize_ + sizeof (MyTemplate); } private: int dsize_; T *data_; }; Let us implement an xmethod for the above class which serves as a replacement for the `footprint' method. The full code listing of the xmethod workers and xmethod matchers is as follows: class MyTemplateWorker_footprint(gdb.xmethod.XMethodWorker): def __init__(self, class_type): self.class_type = class_type def get_arg_types(self): return None def get_result_type(self): return gdb.lookup_type('int') def __call__(self, obj): return (self.class_type.sizeof + obj['dsize_'] * self.class_type.template_argument(0).sizeof) class MyTemplateMatcher_footprint(gdb.xmethod.XMethodMatcher): def __init__(self): gdb.xmethod.XMethodMatcher.__init__(self, 'MyTemplateMatcher') def match(self, class_type, method_name): if (re.match('MyTemplate<[ \t\n]*[_a-zA-Z][ _a-zA-Z0-9]*>', class_type.tag) and method_name == 'footprint'): return MyTemplateWorker_footprint(class_type) Notice that, in this example, we have not used the `methods' attribute of the matcher as the matcher manages only one xmethod. The user can enable/disable this xmethod by enabling/disabling the matcher itself.  File: gdb.info, Node: Inferiors In Python, Next: Events In Python, Prev: Writing an Xmethod, Up: Python API 23.3.2.17 Inferiors In Python ............................. Programs which are being run under GDB are called inferiors (*note Inferiors Connections and Programs::). Python scripts can access information about and manipulate inferiors controlled by GDB via objects of the `gdb.Inferior' class. The following inferior-related functions are available in the `gdb' module: -- Function: gdb.inferiors () Return a tuple containing all inferior objects. -- Function: gdb.selected_inferior () Return an object representing the current inferior. A `gdb.Inferior' object has the following attributes: -- Variable: Inferior.num ID of inferior, as assigned by GDB. You can use this to make Python breakpoints inferior-specific, for example (*note The Breakpoint.inferior attribute: python_breakpoint_inferior.). -- Variable: Inferior.connection The `gdb.TargetConnection' for this inferior (*note Connections In Python::), or `None' if this inferior has no connection. -- Variable: Inferior.connection_num ID of inferior's connection as assigned by GDB, or None if the inferior is not connected to a target. *Note Inferiors Connections and Programs::. This is equivalent to `gdb.Inferior.connection.num' in the case where `gdb.Inferior.connection' is not `None'. -- Variable: Inferior.pid Process ID of the inferior, as assigned by the underlying operating system. -- Variable: Inferior.was_attached Boolean signaling whether the inferior was created using `attach', or started by GDB itself. -- Variable: Inferior.main_name A string holding the name of this inferior's "main" function, if it can be determined. If the name of main is not known, this is `None'. -- Variable: Inferior.progspace The inferior's program space. *Note Progspaces In Python::. -- Variable: Inferior.arguments The inferior's command line arguments, if known. This corresponds to the `set args' and `show args' commands. *Note Arguments::. When accessed, the value is a string holding all the arguments. The contents are quoted as they would be when passed to the shell. If there are no arguments, the value is `None'. Either a string or a sequence of strings can be assigned to this attribute. When a string is assigned, it is assumed to have any necessary quoting for the shell; when a sequence is assigned, the quoting is applied by GDB. A `gdb.Inferior' object has the following methods: -- Function: Inferior.is_valid () Returns `True' if the `gdb.Inferior' object is valid, `False' if not. A `gdb.Inferior' object will become invalid if the inferior no longer exists within GDB. All other `gdb.Inferior' methods will throw an exception if it is invalid at the time the method is called. -- Function: Inferior.threads () This method returns a tuple holding all the threads which are valid when it is called. If there are no valid threads, the method will return an empty tuple. -- Function: Inferior.architecture () Return the `gdb.Architecture' (*note Architectures In Python::) for this inferior. This represents the architecture of the inferior as a whole. Some platforms can have multiple architectures in a single address space, so this may not match the architecture of a particular frame (*note Frames In Python::). -- Function: Inferior.read_memory (address, length) Read LENGTH addressable memory units from the inferior, starting at ADDRESS. Returns a `memoryview' object, which behaves much like an array or a string. It can be modified and given to the `Inferior.write_memory' function. -- Function: Inferior.write_memory (address, buffer [, length]) Write the contents of BUFFER to the inferior, starting at ADDRESS. The BUFFER parameter must be a Python object which supports the buffer protocol, i.e., a string, an array or the object returned from `Inferior.read_memory'. If given, LENGTH determines the number of addressable memory units from BUFFER to be written. -- Function: Inferior.search_memory (address, length, pattern) Search a region of the inferior memory starting at ADDRESS with the given LENGTH using the search pattern supplied in PATTERN. The PATTERN parameter must be a Python object which supports the buffer protocol, i.e., a string, an array or the object returned from `gdb.read_memory'. Returns a Python `Long' containing the address where the pattern was found, or `None' if the pattern could not be found. -- Function: Inferior.thread_from_handle (handle) Return the thread object corresponding to HANDLE, a thread library specific data structure such as `pthread_t' for pthreads library implementations. The function `Inferior.thread_from_thread_handle' provides the same functionality, but use of `Inferior.thread_from_thread_handle' is deprecated. The environment that will be passed to the inferior can be changed from Python by using the following methods. These methods only take effect when the inferior is started - they will not affect an inferior that is already executing. -- Function: Inferior.clear_env () Clear the current environment variables that will be passed to this inferior. -- Function: Inferior.set_env (name, value) Set the environment variable NAME to have the indicated value. Both parameters must be strings. -- Function: Inferior.unset_env (name) Unset the environment variable NAME. NAME must be a string. One may add arbitrary attributes to `gdb.Inferior' objects in the usual Python way. This is useful if, for example, one needs to do some extra record keeping associated with the inferior. When selecting a name for a new attribute, avoid starting the new attribute name with a lower case letter; future attributes added by GDB will start with a lower case letter. Additionally, avoid starting attribute names with two underscore characters, as these could clash with Python builtin attribute names. In this contrived example we record the time when an inferior last stopped: (gdb) python import datetime def thread_stopped(event): if event.inferior_thread is not None: thread = event.inferior_thread else: thread = gdb.selected_thread() inferior = thread.inferior inferior._last_stop_time = datetime.datetime.today() gdb.events.stop.connect(thread_stopped) (gdb) file /tmp/hello Reading symbols from /tmp/hello... (gdb) start Temporary breakpoint 1 at 0x401198: file /tmp/hello.c, line 18. Starting program: /tmp/hello Temporary breakpoint 1, main () at /tmp/hello.c:18 18 printf ("Hello World\n"); (gdb) python print(gdb.selected_inferior()._last_stop_time) 2024-01-04 14:48:41.347036  File: gdb.info, Node: Events In Python, Next: Threads In Python, Prev: Inferiors In Python, Up: Python API 23.3.2.18 Events In Python .......................... GDB provides a general event facility so that Python code can be notified of various state changes, particularly changes that occur in the inferior. An "event" is just an object that describes some state change. The type of the object and its attributes will vary depending on the details of the change. All the existing events are described below. In order to be notified of an event, you must register an event handler with an "event registry". An event registry is an object in the `gdb.events' module which dispatches particular events. A registry provides methods to register and unregister event handlers: -- Function: EventRegistry.connect (object) Add the given callable OBJECT to the registry. This object will be called when an event corresponding to this registry occurs. -- Function: EventRegistry.disconnect (object) Remove the given OBJECT from the registry. Once removed, the object will no longer receive notifications of events. Here is an example: def exit_handler (event): print ("event type: exit") if hasattr (event, 'exit_code'): print ("exit code: %d" % (event.exit_code)) else: print ("exit code not available") gdb.events.exited.connect (exit_handler) In the above example we connect our handler `exit_handler' to the registry `events.exited'. Once connected, `exit_handler' gets called when the inferior exits. The argument "event" in this example is of type `gdb.ExitedEvent'. As you can see in the example the `ExitedEvent' object has an attribute which indicates the exit code of the inferior. Some events can be thread specific when GDB is running in non-stop mode. When represented in Python, these events all extend `gdb.ThreadEvent'. This event is a base class and is never emitted directly; instead, events which are emitted by this or other modules might extend this event. Examples of these events are `gdb.BreakpointEvent' and `gdb.ContinueEvent'. `gdb.ThreadEvent' holds the following attributes: -- Variable: ThreadEvent.inferior_thread In non-stop mode this attribute will be set to the specific thread which was involved in the emitted event. Otherwise, it will be set to `None'. The following is a listing of the event registries that are available and details of the events they emit: `events.cont' Emits `gdb.ContinueEvent', which extends `gdb.ThreadEvent'. This event indicates that the inferior has been continued after a stop. For inherited attribute refer to `gdb.ThreadEvent' above. `events.exited' Emits `events.ExitedEvent', which indicates that the inferior has exited. `events.ExitedEvent' has two attributes: -- Variable: ExitedEvent.exit_code An integer representing the exit code, if available, which the inferior has returned. (The exit code could be unavailable if, for example, GDB detaches from the inferior.) If the exit code is unavailable, the attribute does not exist. -- Variable: ExitedEvent.inferior A reference to the inferior which triggered the `exited' event. `events.stop' Emits `gdb.StopEvent', which extends `gdb.ThreadEvent'. Indicates that the inferior has stopped. All events emitted by this registry extend `gdb.StopEvent'. As a child of `gdb.ThreadEvent', `gdb.StopEvent' will indicate the stopped thread when GDB is running in non-stop mode. Refer to `gdb.ThreadEvent' above for more details. `gdb.StopEvent' has the following additional attributes: -- Variable: StopEvent.details A dictionary holding any details relevant to the stop. The exact keys and values depend on the type of stop, but are identical to the corresponding MI output (*note GDB/MI Async Records::). A dictionary was used for this (rather than adding attributes directly to the event object) so that the MI keys could be used unchanged. When a `StopEvent' results from a `finish' command, it will also hold the return value from the function, if that is available. This will be an entry named `return-value' in the `details' dictionary. The value of this entry will be a `gdb.Value' object. Emits `gdb.SignalEvent', which extends `gdb.StopEvent'. This event indicates that the inferior or one of its threads has received a signal. `gdb.SignalEvent' has the following attributes: -- Variable: SignalEvent.stop_signal A string representing the signal received by the inferior. A list of possible signal values can be obtained by running the command `info signals' in the GDB command prompt. Also emits `gdb.BreakpointEvent', which extends `gdb.StopEvent'. `gdb.BreakpointEvent' event indicates that one or more breakpoints have been hit, and has the following attributes: -- Variable: BreakpointEvent.breakpoints A sequence containing references to all the breakpoints (type `gdb.Breakpoint') that were hit. *Note Breakpoints In Python::, for details of the `gdb.Breakpoint' object. -- Variable: BreakpointEvent.breakpoint A reference to the first breakpoint that was hit. This attribute is maintained for backward compatibility and is now deprecated in favor of the `gdb.BreakpointEvent.breakpoints' attribute. `events.new_objfile' Emits `gdb.NewObjFileEvent' which indicates that a new object file has been loaded by GDB. `gdb.NewObjFileEvent' has one attribute: -- Variable: NewObjFileEvent.new_objfile A reference to the object file (`gdb.Objfile') which has been loaded. *Note Objfiles In Python::, for details of the `gdb.Objfile' object. `events.free_objfile' Emits `gdb.FreeObjFileEvent' which indicates that an object file is about to be removed from GDB. One reason this can happen is when the inferior calls `dlclose'. `gdb.FreeObjFileEvent' has one attribute: -- Variable: FreeObjFileEvent.objfile A reference to the object file (`gdb.Objfile') which will be unloaded. *Note Objfiles In Python::, for details of the `gdb.Objfile' object. `events.clear_objfiles' Emits `gdb.ClearObjFilesEvent' which indicates that the list of object files for a program space has been reset. `gdb.ClearObjFilesEvent' has one attribute: -- Variable: ClearObjFilesEvent.progspace A reference to the program space (`gdb.Progspace') whose objfile list has been cleared. *Note Progspaces In Python::. `events.inferior_call' Emits events just before and after a function in the inferior is called by GDB. Before an inferior call, this emits an event of type `gdb.InferiorCallPreEvent', and after an inferior call, this emits an event of type `gdb.InferiorCallPostEvent'. ``gdb.InferiorCallPreEvent'' Indicates that a function in the inferior is about to be called. -- Variable: InferiorCallPreEvent.ptid The thread in which the call will be run. -- Variable: InferiorCallPreEvent.address The location of the function to be called. ``gdb.InferiorCallPostEvent'' Indicates that a function in the inferior has just been called. -- Variable: InferiorCallPostEvent.ptid The thread in which the call was run. -- Variable: InferiorCallPostEvent.address The location of the function that was called. `events.memory_changed' Emits `gdb.MemoryChangedEvent' which indicates that the memory of the inferior has been modified by the GDB user, for instance via a command like `set *addr = value'. The event has the following attributes: -- Variable: MemoryChangedEvent.address The start address of the changed region. -- Variable: MemoryChangedEvent.length Length in bytes of the changed region. `events.register_changed' Emits `gdb.RegisterChangedEvent' which indicates that a register in the inferior has been modified by the GDB user. -- Variable: RegisterChangedEvent.frame A gdb.Frame object representing the frame in which the register was modified. -- Variable: RegisterChangedEvent.regnum Denotes which register was modified. `events.breakpoint_created' This is emitted when a new breakpoint has been created. The argument that is passed is the new `gdb.Breakpoint' object. `events.breakpoint_modified' This is emitted when a breakpoint has been modified in some way. The argument that is passed is the new `gdb.Breakpoint' object. `events.breakpoint_deleted' This is emitted when a breakpoint has been deleted. The argument that is passed is the `gdb.Breakpoint' object. When this event is emitted, the `gdb.Breakpoint' object will already be in its invalid state; that is, the `is_valid' method will return `False'. `events.before_prompt' This event carries no payload. It is emitted each time GDB presents a prompt to the user. `events.new_inferior' This is emitted when a new inferior is created. Note that the inferior is not necessarily running; in fact, it may not even have an associated executable. The event is of type `gdb.NewInferiorEvent'. This has a single attribute: -- Variable: NewInferiorEvent.inferior The new inferior, a `gdb.Inferior' object. `events.inferior_deleted' This is emitted when an inferior has been deleted. Note that this is not the same as process exit; it is notified when the inferior itself is removed, say via `remove-inferiors'. The event is of type `gdb.InferiorDeletedEvent'. This has a single attribute: -- Variable: InferiorDeletedEvent.inferior The inferior that is being removed, a `gdb.Inferior' object. `events.new_thread' This is emitted when GDB notices a new thread. The event is of type `gdb.NewThreadEvent', which extends `gdb.ThreadEvent'. This has a single attribute: -- Variable: NewThreadEvent.inferior_thread The new thread. `events.thread_exited' This is emitted when GDB notices a thread has exited. The event is of type `gdb.ThreadExitedEvent' which extends `gdb.ThreadEvent'. This has a single attribute: -- Variable: ThreadExitedEvent.inferior_thread The exiting thread. `events.gdb_exiting' This is emitted when GDB exits. This event is not emitted if GDB exits as a result of an internal error, or after an unexpected signal. The event is of type `gdb.GdbExitingEvent', which has a single attribute: -- Variable: GdbExitingEvent.exit_code An integer, the value of the exit code GDB will return. `events.connection_removed' This is emitted when GDB removes a connection (*note Connections In Python::). The event is of type `gdb.ConnectionEvent'. This has a single read-only attribute: -- Variable: ConnectionEvent.connection The `gdb.TargetConnection' that is being removed. `events.executable_changed' Emits `gdb.ExecutableChangedEvent' which indicates that the `gdb.Progspace.executable_filename' has changed. This event is emitted when either the value of `gdb.Progspace.executable_filename ' has changed to name a different file, or the executable file named by `gdb.Progspace.executable_filename' has changed on disk, and GDB has therefore reloaded it. -- Variable: ExecutableChangedEvent.progspace The `gdb.Progspace' in which the current executable has changed. The file name of the updated executable will be visible in `gdb.Progspace.executable_filename' (*note Progspaces In Python::). -- Variable: ExecutableChangedEvent.reload This attribute will be `True' if the value of `gdb.Progspace.executable_filename' didn't change, but the file it names changed on disk instead, and GDB reloaded it. When this attribute is `False', the value in `gdb.Progspace.executable_filename' was changed to name a different file. Remember that GDB tracks the executable file and the symbol file separately, these are visible as `gdb.Progspace.executable_filename' and `gdb.Progspace.filename' respectively. When using the `file' command, GDB updates both of these fields, but the executable file is updated first, so when this event is emitted, the executable filename will have changed, but the symbol filename might still hold its previous value. `events.new_progspace' This is emitted when GDB adds a new program space (*note Program Spaces In Python: Progspaces In Python.). The event is of type `gdb.NewProgspaceEvent', and has a single read-only attribute: -- Variable: NewProgspaceEvent.progspace The `gdb.Progspace' that was added to GDB. No `NewProgspaceEvent' is emitted for the very first program space, which is assigned to the first inferior. This first program space is created within GDB before any Python scripts are sourced. `events.free_progspace' This is emitted when GDB removes a program space (*note Program Spaces In Python: Progspaces In Python.), for example as a result of the `remove-inferiors' command (*note `remove-inferiors': remove_inferiors_cli.). The event is of type `gdb.FreeProgspaceEvent', and has a single read-only attribute: -- Variable: FreeProgspaceEvent.progspace The `gdb.Progspace' that is about to be removed from GDB.  File: gdb.info, Node: Threads In Python, Next: Recordings In Python, Prev: Events In Python, Up: Python API 23.3.2.19 Threads In Python ........................... Python scripts can access information about, and manipulate inferior threads controlled by GDB, via objects of the `gdb.InferiorThread' class. The following thread-related functions are available in the `gdb' module: -- Function: gdb.selected_thread () This function returns the thread object for the selected thread. If there is no selected thread, this will return `None'. To get the list of threads for an inferior, use the `Inferior.threads()' method. *Note Inferiors In Python::. A `gdb.InferiorThread' object has the following attributes: -- Variable: InferiorThread.name The name of the thread. If the user specified a name using `thread name', then this returns that name. Otherwise, if an OS-supplied name is available, then it is returned. Otherwise, this returns `None'. This attribute can be assigned to. The new value must be a string object, which sets the new name, or `None', which removes any user-specified thread name. -- Variable: InferiorThread.num The per-inferior number of the thread, as assigned by GDB. -- Variable: InferiorThread.global_num The global ID of the thread, as assigned by GDB. You can use this to make Python breakpoints thread-specific, for example (*note The Breakpoint.thread attribute: python_breakpoint_thread.). -- Variable: InferiorThread.ptid ID of the thread, as assigned by the operating system. This attribute is a tuple containing three integers. The first is the Process ID (PID); the second is the Lightweight Process ID (LWPID), and the third is the Thread ID (TID). Either the LWPID or TID may be 0, which indicates that the operating system does not use that identifier. -- Variable: InferiorThread.ptid_string This read-only attribute contains a string representing `InferiorThread.ptid'. This is the string that GDB uses in the `Target Id' column in the `info threads' output (*note `info threads': info_threads.). -- Variable: InferiorThread.inferior The inferior this thread belongs to. This attribute is represented as a `gdb.Inferior' object. This attribute is not writable. -- Variable: InferiorThread.details A string containing target specific thread state information. The format of this string varies by target. If there is no additional state information for this thread, then this attribute contains `None'. For example, on a GNU/Linux system, a thread that is in the process of exiting will return the string `Exiting'. For remote targets the `details' string will be obtained with the `qThreadExtraInfo' remote packet, if the target supports it (*note `qThreadExtraInfo': qThreadExtraInfo.). GDB displays the `details' string as part of the `Target Id' column, in the `info threads' output (*note `info threads': info_threads.). A `gdb.InferiorThread' object has the following methods: -- Function: InferiorThread.is_valid () Returns `True' if the `gdb.InferiorThread' object is valid, `False' if not. A `gdb.InferiorThread' object will become invalid if the thread exits, or the inferior that the thread belongs is deleted. All other `gdb.InferiorThread' methods will throw an exception if it is invalid at the time the method is called. -- Function: InferiorThread.switch () This changes GDB's currently selected thread to the one represented by this object. -- Function: InferiorThread.is_stopped () Return a Boolean indicating whether the thread is stopped. -- Function: InferiorThread.is_running () Return a Boolean indicating whether the thread is running. -- Function: InferiorThread.is_exited () Return a Boolean indicating whether the thread is exited. -- Function: InferiorThread.handle () Return the thread object's handle, represented as a Python `bytes' object. A `gdb.Value' representation of the handle may be constructed via `gdb.Value(bufobj, type)' where BUFOBJ is the Python `bytes' representation of the handle and TYPE is a `gdb.Type' for the handle type. One may add arbitrary attributes to `gdb.InferiorThread' objects in the usual Python way. This is useful if, for example, one needs to do some extra record keeping associated with the thread. *Note choosing attribute names::, for guidance on selecting a suitable name for new attributes. In this contrived example we record the time when a thread last stopped: (gdb) python import datetime def thread_stopped(event): if event.inferior_thread is not None: thread = event.inferior_thread else: thread = gdb.selected_thread() thread._last_stop_time = datetime.datetime.today() gdb.events.stop.connect(thread_stopped) (gdb) file /tmp/hello Reading symbols from /tmp/hello... (gdb) start Temporary breakpoint 1 at 0x401198: file /tmp/hello.c, line 18. Starting program: /tmp/hello Temporary breakpoint 1, main () at /tmp/hello.c:18 18 printf ("Hello World\n"); (gdb) python print(gdb.selected_thread()._last_stop_time) 2024-01-04 14:48:41.347036  File: gdb.info, Node: Recordings In Python, Next: CLI Commands In Python, Prev: Threads In Python, Up: Python API 23.3.2.20 Recordings In Python .............................. The following recordings-related functions (*note Process Record and Replay::) are available in the `gdb' module: -- Function: gdb.start_recording ([method], [format]) Start a recording using the given METHOD and FORMAT. If no FORMAT is given, the default format for the recording method is used. If no METHOD is given, the default method will be used. Returns a `gdb.Record' object on success. Throw an exception on failure. The following strings can be passed as METHOD: * `"full"' * `"btrace"': Possible values for FORMAT: `"pt"', `"bts"' or leave out for default format. -- Function: gdb.current_recording () Access a currently running recording. Return a `gdb.Record' object on success. Return `None' if no recording is currently active. -- Function: gdb.stop_recording () Stop the current recording. Throw an exception if no recording is currently active. All record objects become invalid after this call. A `gdb.Record' object has the following attributes: -- Variable: Record.method A string with the current recording method, e.g. `full' or `btrace'. -- Variable: Record.format A string with the current recording format, e.g. `bt', `pts' or `None'. -- Variable: Record.begin A method specific instruction object representing the first instruction in this recording. -- Variable: Record.end A method specific instruction object representing the current instruction, that is not actually part of the recording. -- Variable: Record.replay_position The instruction representing the current replay position. If there is no replay active, this will be `None'. -- Variable: Record.instruction_history A list with all recorded instructions. -- Variable: Record.function_call_history A list with all recorded function call segments. A `gdb.Record' object has the following methods: -- Function: Record.goto (instruction) Move the replay position to the given INSTRUCTION. The common `gdb.Instruction' class that recording method specific instruction objects inherit from, has the following attributes: -- Variable: Instruction.pc An integer representing this instruction's address. -- Variable: Instruction.data A `memoryview' object holding the raw instruction data. -- Variable: Instruction.decoded A human readable string with the disassembled instruction. -- Variable: Instruction.size The size of the instruction in bytes. Additionally `gdb.RecordInstruction' has the following attributes: -- Variable: RecordInstruction.number An integer identifying this instruction. `number' corresponds to the numbers seen in `record instruction-history' (*note Process Record and Replay::). -- Variable: RecordInstruction.sal A `gdb.Symtab_and_line' object representing the associated symtab and line of this instruction. May be `None' if no debug information is available. -- Variable: RecordInstruction.is_speculative A boolean indicating whether the instruction was executed speculatively. If an error occurred during recording or decoding a recording, this error is represented by a `gdb.RecordGap' object in the instruction list. It has the following attributes: -- Variable: RecordGap.number An integer identifying this gap. `number' corresponds to the numbers seen in `record instruction-history' (*note Process Record and Replay::). -- Variable: RecordGap.error_code A numerical representation of the reason for the gap. The value is specific to the current recording method. -- Variable: RecordGap.error_string A human readable string with the reason for the gap. A `gdb.RecordFunctionSegment' object has the following attributes: -- Variable: RecordFunctionSegment.number An integer identifying this function segment. `number' corresponds to the numbers seen in `record function-call-history' (*note Process Record and Replay::). -- Variable: RecordFunctionSegment.symbol A `gdb.Symbol' object representing the associated symbol. May be `None' if no debug information is available. -- Variable: RecordFunctionSegment.level An integer representing the function call's stack level. May be `None' if the function call is a gap. -- Variable: RecordFunctionSegment.instructions A list of `gdb.RecordInstruction' or `gdb.RecordGap' objects associated with this function call. -- Variable: RecordFunctionSegment.up A `gdb.RecordFunctionSegment' object representing the caller's function segment. If the call has not been recorded, this will be the function segment to which control returns. If neither the call nor the return have been recorded, this will be `None'. -- Variable: RecordFunctionSegment.prev A `gdb.RecordFunctionSegment' object representing the previous segment of this function call. May be `None'. -- Variable: RecordFunctionSegment.next A `gdb.RecordFunctionSegment' object representing the next segment of this function call. May be `None'. The following example demonstrates the usage of these objects and functions to create a function that will rewind a record to the last time a function in a different file was executed. This would typically be used to track the execution of user provided callback functions in a library which typically are not visible in a back trace. def bringback (): rec = gdb.current_recording () if not rec: return insn = rec.instruction_history if len (insn) == 0: return try: position = insn.index (rec.replay_position) except: position = -1 try: filename = insn[position].sal.symtab.fullname () except: filename = None for i in reversed (insn[:position]): try: current = i.sal.symtab.fullname () except: current = None if filename == current: continue rec.goto (i) return Another possible application is to write a function that counts the number of code executions in a given line range. This line range can contain parts of functions or span across several functions and is not limited to be contiguous. def countrange (filename, linerange): count = 0 def filter_only (file_name): for call in gdb.current_recording ().function_call_history: try: if file_name in call.symbol.symtab.fullname (): yield call except: pass for c in filter_only (filename): for i in c.instructions: try: if i.sal.line in linerange: count += 1 break; except: pass return count  File: gdb.info, Node: CLI Commands In Python, Next: GDB/MI Commands In Python, Prev: Recordings In Python, Up: Python API 23.3.2.21 CLI Commands In Python ................................ You can implement new GDB CLI commands in Python. A CLI command is implemented using an instance of the `gdb.Command' class, most commonly using a subclass. -- Function: Command.__init__ (name, command_class [, completer_class [, prefix]]) The object initializer for `Command' registers the new command with GDB. This initializer is normally invoked from the subclass' own `__init__' method. NAME is the name of the command. If NAME consists of multiple words, then the initial words are looked for as prefix commands. In this case, if one of the prefix commands does not exist, an exception is raised. There is no support for multi-line commands. COMMAND_CLASS should be one of the `COMMAND_' constants defined below. This argument tells GDB how to categorize the new command in the help system. COMPLETER_CLASS is an optional argument. If given, it should be one of the `COMPLETE_' constants defined below. This argument tells GDB how to perform completion for this command. If not given, GDB will attempt to complete using the object's `complete' method (see below); if no such method is found, an error will occur when completion is attempted. PREFIX is an optional argument. If `True', then the new command is a prefix command; sub-commands of this command may be registered. The help text for the new command is taken from the Python documentation string for the command's class, if there is one. If no documentation string is provided, the default value "This command is not documented." is used. -- Function: Command.dont_repeat () By default, a GDB command is repeated when the user enters a blank line at the command prompt. A command can suppress this behavior by invoking the `dont_repeat' method at some point in its `invoke' method (normally this is done early in case of exception). This is similar to the user command `dont-repeat', see *Note dont-repeat: Define. -- Function: Command.invoke (argument, from_tty) This method is called by GDB when this command is invoked. ARGUMENT is a string. It is the argument to the command, after leading and trailing whitespace has been stripped. FROM_TTY is a boolean argument. When true, this means that the command was entered by the user at the terminal; when false it means that the command came from elsewhere. If this method throws an exception, it is turned into a GDB `error' call. Otherwise, the return value is ignored. To break ARGUMENT up into an argv-like string use `gdb.string_to_argv'. This function behaves identically to GDB's internal argument lexer `buildargv'. It is recommended to use this for consistency. Arguments are separated by spaces and may be quoted. Example: print gdb.string_to_argv ("1 2\ \\\"3 '4 \"5' \"6 '7\"") ['1', '2 "3', '4 "5', "6 '7"] -- Function: Command.complete (text, word) This method is called by GDB when the user attempts completion on this command. All forms of completion are handled by this method, that is, the and key bindings (*note Completion::), and the `complete' command (*note complete: Help.). The arguments TEXT and WORD are both strings; TEXT holds the complete command line up to the cursor's location, while WORD holds the last word of the command line; this is computed using a word-breaking heuristic. The `complete' method can return several values: * If the return value is a sequence, the contents of the sequence are used as the completions. It is up to `complete' to ensure that the contents actually do complete the word. A zero-length sequence is allowed, it means that there were no completions available. Only string elements of the sequence are used; other elements in the sequence are ignored. * If the return value is one of the `COMPLETE_' constants defined below, then the corresponding GDB-internal completion function is invoked, and its result is used. * All other results are treated as though there were no available completions. When a new command is registered, it must be declared as a member of some general class of commands. This is used to classify top-level commands in the on-line help system; note that prefix commands are not listed under their own category but rather that of their top-level command. The available classifications are represented by constants defined in the `gdb' module: `gdb.COMMAND_NONE' The command does not belong to any particular class. A command in this category will not be displayed in any of the help categories. `gdb.COMMAND_RUNNING' The command is related to running the inferior. For example, `start', `step', and `continue' are in this category. Type `help running' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_DATA' The command is related to data or variables. For example, `call', `find', and `print' are in this category. Type `help data' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_STACK' The command has to do with manipulation of the stack. For example, `backtrace', `frame', and `return' are in this category. Type `help stack' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_FILES' This class is used for file-related commands. For example, `file', `list' and `section' are in this category. Type `help files' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_SUPPORT' This should be used for "support facilities", generally meaning things that are useful to the user when interacting with GDB, but not related to the state of the inferior. For example, `help', `make', and `shell' are in this category. Type `help support' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_STATUS' The command is an `info'-related command, that is, related to the state of GDB itself. For example, `info', `macro', and `show' are in this category. Type `help status' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_BREAKPOINTS' The command has to do with breakpoints. For example, `break', `clear', and `delete' are in this category. Type `help breakpoints' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_TRACEPOINTS' The command has to do with tracepoints. For example, `trace', `actions', and `tfind' are in this category. Type `help tracepoints' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_TUI' The command has to do with the text user interface (*note TUI::). Type `help tui' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_USER' The command is a general purpose command for the user, and typically does not fit in one of the other categories. Type `help user-defined' at the GDB prompt to see a list of commands in this category, as well as the list of gdb macros (*note Sequences::). `gdb.COMMAND_OBSCURE' The command is only used in unusual circumstances, or is not of general interest to users. For example, `checkpoint', `fork', and `stop' are in this category. Type `help obscure' at the GDB prompt to see a list of commands in this category. `gdb.COMMAND_MAINTENANCE' The command is only useful to GDB maintainers. The `maintenance' and `flushregs' commands are in this category. Type `help internals' at the GDB prompt to see a list of commands in this category. A new command can use a predefined completion function, either by specifying it via an argument at initialization, or by returning it from the `complete' method. These predefined completion constants are all defined in the `gdb' module: `gdb.COMPLETE_NONE' This constant means that no completion should be done. `gdb.COMPLETE_FILENAME' This constant means that filename completion should be performed. `gdb.COMPLETE_LOCATION' This constant means that location completion should be done. *Note Location Specifications::. `gdb.COMPLETE_COMMAND' This constant means that completion should examine GDB command names. `gdb.COMPLETE_SYMBOL' This constant means that completion should be done using symbol names as the source. `gdb.COMPLETE_EXPRESSION' This constant means that completion should be done on expressions. Often this means completing on symbol names, but some language parsers also have support for completing on field names. The following code snippet shows how a trivial CLI command can be implemented in Python: class HelloWorld (gdb.Command): """Greet the whole world.""" def __init__ (self): super (HelloWorld, self).__init__ ("hello-world", gdb.COMMAND_USER) def invoke (self, arg, from_tty): print ("Hello, World!") HelloWorld () The last line instantiates the class, and is necessary to trigger the registration of the command with GDB. Depending on how the Python code is read into GDB, you may need to import the `gdb' module explicitly.  File: gdb.info, Node: GDB/MI Commands In Python, Next: GDB/MI Notifications In Python, Prev: CLI Commands In Python, Up: Python API 23.3.2.22 GDB/MI Commands In Python ................................... It is possible to add GDB/MI (*note GDB/MI::) commands implemented in Python. A GDB/MI command is implemented using an instance of the `gdb.MICommand' class, most commonly using a subclass. -- Function: MICommand.__init__ (name) The object initializer for `MICommand' registers the new command with GDB. This initializer is normally invoked from the subclass' own `__init__' method. NAME is the name of the command. It must be a valid name of a GDB/MI command, and in particular must start with a hyphen (`-'). Reusing the name of a built-in GDB/MI is not allowed, and a `RuntimeError' will be raised. Using the name of an GDB/MI command previously defined in Python is allowed, the previous command will be replaced with the new command. -- Function: MICommand.invoke (arguments) This method is called by GDB when the new MI command is invoked. ARGUMENTS is a list of strings. Note, that `--thread' and `--frame' arguments are handled by GDB itself therefore they do not show up in `arguments'. If this method raises an exception, then it is turned into a GDB/MI `^error' response. Only `gdb.GdbError' exceptions (or its sub-classes) should be used for reporting errors to users, any other exception type is treated as a failure of the `invoke' method, and the exception will be printed to the error stream according to the `set python print-stack' setting (*note `set python print-stack': set_python_print_stack.). If this method returns `None', then the GDB/MI command will return a `^done' response with no additional values. Otherwise, the return value must be a dictionary, which is converted to a GDB/MI RESULT-RECORD (*note GDB/MI Output Syntax::). The keys of this dictionary must be strings, and are used as VARIABLE names in the RESULT-RECORD, these strings must comply with the naming rules detailed below. The values of this dictionary are recursively handled as follows: * If the value is Python sequence or iterator, it is converted to GDB/MI LIST with elements converted recursively. * If the value is Python dictionary, it is converted to GDB/MI TUPLE. Keys in that dictionary must be strings, which comply with the VARIABLE naming rules detailed below. Values are converted recursively. * Otherwise, value is first converted to a Python string using `str ()' and then converted to GDB/MI CONST. The strings used for VARIABLE names in the GDB/MI output must follow the following rules; the string must be at least one character long, the first character must be in the set `[a-zA-Z]', while every subsequent character must be in the set `[-_a-zA-Z0-9]'. An instance of `MICommand' has the following attributes: -- Variable: MICommand.name A string, the name of this GDB/MI command, as was passed to the `__init__' method. This attribute is read-only. -- Variable: MICommand.installed A boolean value indicating if this command is installed ready for a user to call from the command line. Commands are automatically installed when they are instantiated, after which this attribute will be `True'. If later, a new command is created with the same name, then the original command will become uninstalled, and this attribute will be `False'. This attribute is read-write, setting this attribute to `False' will uninstall the command, removing it from the set of available commands. Setting this attribute to `True' will install the command for use. If there is already a Python command with this name installed, the currently installed command will be uninstalled, and this command installed in its stead. The following code snippet shows how some trivial MI commands can be implemented in Python: class MIEcho(gdb.MICommand): """Echo arguments passed to the command.""" def __init__(self, name, mode): self._mode = mode super(MIEcho, self).__init__(name) def invoke(self, argv): if self._mode == 'dict': return { 'dict': { 'argv' : argv } } elif self._mode == 'list': return { 'list': argv } else: return { 'string': ", ".join(argv) } MIEcho("-echo-dict", "dict") MIEcho("-echo-list", "list") MIEcho("-echo-string", "string") The last three lines instantiate the class three times, creating three new GDB/MI commands `-echo-dict', `-echo-list', and `-echo-string'. Each time a subclass of `gdb.MICommand' is instantiated, the new command is automatically registered with GDB. Depending on how the Python code is read into GDB, you may need to import the `gdb' module explicitly. The following example shows a GDB session in which the above commands have been added: (gdb) -echo-dict abc def ghi ^done,dict={argv=["abc","def","ghi"]} (gdb) -echo-list abc def ghi ^done,list=["abc","def","ghi"] (gdb) -echo-string abc def ghi ^done,string="abc, def, ghi" (gdb) Conversely, it is possible to execute GDB/MI commands from Python, with the results being a Python object and not a specially-formatted string. This is done with the `gdb.execute_mi' function. -- Function: gdb.execute_mi (command [, arg ]...) Invoke a GDB/MI command. COMMAND is the name of the command, a string. The arguments, ARG, are passed to the command. Each argument must also be a string. This function returns a Python dictionary whose contents reflect the corresponding GDB/MI command's output. Refer to the documentation for these commands for details. Lists are represented as Python lists, and tuples are represented as Python dictionaries. If the command fails, it will raise a Python exception. Here is how this works using the commands from the example above: (gdb) python print(gdb.execute_mi("-echo-dict", "abc", "def", "ghi")) {'dict': {'argv': ['abc', 'def', 'ghi']}} (gdb) python print(gdb.execute_mi("-echo-list", "abc", "def", "ghi")) {'list': ['abc', 'def', 'ghi']} (gdb) python print(gdb.execute_mi("-echo-string", "abc", "def", "ghi")) {'string': 'abc, def, ghi'}  File: gdb.info, Node: GDB/MI Notifications In Python, Next: Parameters In Python, Prev: GDB/MI Commands In Python, Up: Python API 23.3.2.23 GDB/MI Notifications In Python ........................................ It is possible to emit GDB/MI notifications from Python. Use the `gdb.notify_mi' function to do that. -- Function: gdb.notify_mi (name [, data]) Emit a GDB/MI asynchronous notification. NAME is the name of the notification, consisting of alphanumeric characters and a hyphen (`-'). DATA is any additional data to be emitted with the notification, passed as a Python dictionary. This argument is optional. The dictionary is converted to a GDB/MI RESULT records (*note GDB/MI Output Syntax::) the same way as result of Python MI command (*note GDB/MI Commands In Python::). If DATA is `None' then no additional values are emitted. While using existing notification names (*note GDB/MI Async Records::) with `gdb.notify_mi' is allowed, users are encouraged to prefix user-defined notification with a hyphen (`-') to avoid possible conflict. GDB will never introduce notification starting with hyphen. Here is how to emit `=-connection-removed' whenever a connection to remote GDB server is closed (*note Connections In Python::): def notify_connection_removed(event): data = {"id": event.connection.num, "type": event.connection.type} gdb.notify_mi("-connection-removed", data) gdb.events.connection_removed.connect(notify_connection_removed) Then, each time a connection is closed, there will be a notification on MI channel: =-connection-removed,id="1",type="remote"  File: gdb.info, Node: Parameters In Python, Next: Functions In Python, Prev: GDB/MI Notifications In Python, Up: Python API 23.3.2.24 Parameters In Python .............................. You can implement new GDB parameters using Python. A new parameter is implemented as an instance of the `gdb.Parameter' class. Parameters are exposed to the user via the `set' and `show' commands. *Note Help::. There are many parameters that already exist and can be set in GDB. Two examples are: `set follow fork' and `set charset'. Setting these parameters influences certain behavior in GDB. Similarly, you can define parameters that can be used to influence behavior in custom Python scripts and commands. -- Function: Parameter.__init__ (name, command_class, parameter_class [, enum_sequence]) The object initializer for `Parameter' registers the new parameter with GDB. This initializer is normally invoked from the subclass' own `__init__' method. NAME is the name of the new parameter. If NAME consists of multiple words, then the initial words are looked for as prefix parameters. An example of this can be illustrated with the `set print' set of parameters. If NAME is `print foo', then `print' will be searched as the prefix parameter. In this case the parameter can subsequently be accessed in GDB as `set print foo'. If NAME consists of multiple words, and no prefix parameter group can be found, an exception is raised. COMMAND_CLASS should be one of the `COMMAND_' constants (*note CLI Commands In Python::). This argument tells GDB how to categorize the new parameter in the help system. PARAMETER_CLASS should be one of the `PARAM_' constants defined below. This argument tells GDB the type of the new parameter; this information is used for input validation and completion. If PARAMETER_CLASS is `PARAM_ENUM', then ENUM_SEQUENCE must be a sequence of strings. These strings represent the possible values for the parameter. If PARAMETER_CLASS is not `PARAM_ENUM', then the presence of a fourth argument will cause an exception to be thrown. The help text for the new parameter includes the Python documentation string from the parameter's class, if there is one. If there is no documentation string, a default value is used. The documentation string is included in the output of the parameters `help set' and `help show' commands, and should be written taking this into account. -- Variable: Parameter.set_doc If this attribute exists, and is a string, then its value is used as the first part of the help text for this parameter's `set' command. The second part of the help text is taken from the documentation string for the parameter's class, if there is one. The value of `set_doc' should give a brief summary specific to the set action, this text is only displayed when the user runs the `help set' command for this parameter. The class documentation should be used to give a fuller description of what the parameter does, this text is displayed for both the `help set' and `help show' commands. The `set_doc' value is examined when `Parameter.__init__' is invoked; subsequent changes have no effect. -- Variable: Parameter.show_doc If this attribute exists, and is a string, then its value is used as the first part of the help text for this parameter's `show' command. The second part of the help text is taken from the documentation string for the parameter's class, if there is one. The value of `show_doc' should give a brief summary specific to the show action, this text is only displayed when the user runs the `help show' command for this parameter. The class documentation should be used to give a fuller description of what the parameter does, this text is displayed for both the `help set' and `help show' commands. The `show_doc' value is examined when `Parameter.__init__' is invoked; subsequent changes have no effect. -- Variable: Parameter.value The `value' attribute holds the underlying value of the parameter. It can be read and assigned to just as any other attribute. GDB does validation when assignments are made. There are two methods that may be implemented in any `Parameter' class. These are: -- Function: Parameter.get_set_string (self) If this method exists, GDB will call it when a PARAMETER's value has been changed via the `set' API (for example, `set foo off'). The `value' attribute has already been populated with the new value and may be used in output. This method must return a string. If the returned string is not empty, GDB will present it to the user. If this method raises the `gdb.GdbError' exception (*note Exception Handling::), then GDB will print the exception's string and the `set' command will fail. Note, however, that the `value' attribute will not be reset in this case. So, if your parameter must validate values, it should store the old value internally and reset the exposed value, like so: class ExampleParam (gdb.Parameter): def __init__ (self, name): super (ExampleParam, self).__init__ (name, gdb.COMMAND_DATA, gdb.PARAM_BOOLEAN) self.value = True self.saved_value = True def validate(self): return False def get_set_string (self): if not self.validate(): self.value = self.saved_value raise gdb.GdbError('Failed to validate') self.saved_value = self.value return "" -- Function: Parameter.get_show_string (self, svalue) GDB will call this method when a PARAMETER's `show' API has been invoked (for example, `show foo'). The argument `svalue' receives the string representation of the current value. This method must return a string. When a new parameter is defined, its type must be specified. The available types are represented by constants defined in the `gdb' module: `gdb.PARAM_BOOLEAN' The value is a plain boolean. The Python boolean values, `True' and `False' are the only valid values. `gdb.PARAM_AUTO_BOOLEAN' The value has three possible states: true, false, and `auto'. In Python, true and false are represented using boolean constants, and `auto' is represented using `None'. `gdb.PARAM_UINTEGER' The value is an unsigned integer. The value of `None' should be interpreted to mean "unlimited" (literal `'unlimited'' can also be used to set that value), and the value of 0 is reserved and should not be used. `gdb.PARAM_INTEGER' The value is a signed integer. The value of `None' should be interpreted to mean "unlimited" (literal `'unlimited'' can also be used to set that value), and the value of 0 is reserved and should not be used. `gdb.PARAM_STRING' The value is a string. When the user modifies the string, any escape sequences, such as `\t', `\f', and octal escapes, are translated into corresponding characters and encoded into the current host charset. `gdb.PARAM_STRING_NOESCAPE' The value is a string. When the user modifies the string, escapes are passed through untranslated. `gdb.PARAM_OPTIONAL_FILENAME' The value is a either a filename (a string), or `None'. `gdb.PARAM_FILENAME' The value is a filename. This is just like `PARAM_STRING_NOESCAPE', but uses file names for completion. `gdb.PARAM_ZINTEGER' The value is a signed integer. This is like `PARAM_INTEGER', except that 0 is allowed and the value of `None' is not supported. `gdb.PARAM_ZUINTEGER' The value is an unsigned integer. This is like `PARAM_UINTEGER', except that 0 is allowed and the value of `None' is not supported. `gdb.PARAM_ZUINTEGER_UNLIMITED' The value is a signed integer. This is like `PARAM_INTEGER' including that the value of `None' should be interpreted to mean "unlimited" (literal `'unlimited'' can also be used to set that value), except that 0 is allowed, and the value cannot be negative, except the special value -1 is returned for the setting of "unlimited". `gdb.PARAM_ENUM' The value is a string, which must be one of a collection string constants provided when the parameter is created.  File: gdb.info, Node: Functions In Python, Next: Progspaces In Python, Prev: Parameters In Python, Up: Python API 23.3.2.25 Writing new convenience functions ........................................... You can implement new convenience functions (*note Convenience Vars::) in Python. A convenience function is an instance of a subclass of the class `gdb.Function'. -- Function: Function.__init__ (name) The initializer for `Function' registers the new function with GDB. The argument NAME is the name of the function, a string. The function will be visible to the user as a convenience variable of type `internal function', whose name is the same as the given NAME. The documentation for the new function is taken from the documentation string for the new class. -- Function: Function.invoke (*args) When a convenience function is evaluated, its arguments are converted to instances of `gdb.Value', and then the function's `invoke' method is called. Note that GDB does not predetermine the arity of convenience functions. Instead, all available arguments are passed to `invoke', following the standard Python calling convention. In particular, a convenience function can have default values for parameters without ill effect. The return value of this method is used as its value in the enclosing expression. If an ordinary Python value is returned, it is converted to a `gdb.Value' following the usual rules. The following code snippet shows how a trivial convenience function can be implemented in Python: class Greet (gdb.Function): """Return string to greet someone. Takes a name as argument.""" def __init__ (self): super (Greet, self).__init__ ("greet") def invoke (self, name): return "Hello, %s!" % name.string () Greet () The last line instantiates the class, and is necessary to trigger the registration of the function with GDB. Depending on how the Python code is read into GDB, you may need to import the `gdb' module explicitly. Now you can use the function in an expression: (gdb) print $greet("Bob") $1 = "Hello, Bob!"  File: gdb.info, Node: Progspaces In Python, Next: Objfiles In Python, Prev: Functions In Python, Up: Python API 23.3.2.26 Program Spaces In Python .................................. A program space, or "progspace", represents a symbolic view of an address space. It consists of all of the objfiles of the program. *Note Objfiles In Python::. *Note program spaces: Inferiors Connections and Programs, for more details about program spaces. The following progspace-related functions are available in the `gdb' module: -- Function: gdb.current_progspace () This function returns the program space of the currently selected inferior. *Note Inferiors Connections and Programs::. This is identical to `gdb.selected_inferior().progspace' (*note Inferiors In Python::) and is included for historical compatibility. -- Function: gdb.progspaces () Return a sequence of all the progspaces currently known to GDB. Each progspace is represented by an instance of the `gdb.Progspace' class. -- Variable: Progspace.filename The file name, as a string, of the main symbol file (from which debug symbols have been loaded) for the progspace, e.g. the argument to the `symbol-file' or `file' commands. If there is no main symbol table currently loaded, then this attribute will be `None'. -- Variable: Progspace.symbol_file The `gdb.Objfile' representing the main symbol file (from which debug symbols have been loaded) for the `gdb.Progspace'. This is the symbol file set by the `symbol-file' or `file' commands. This will be the `gdb.Objfile' representing `Progspace.filename' when `Progspace.filename' is not `None'. If there is no main symbol table currently loaded, then this attribute will be `None'. If the `Progspace' is invalid, i.e., when `Progspace.is_valid()' returns `False', then attempting to access this attribute will raise a `RuntimeError' exception. -- Variable: Progspace.executable_filename The file name, as a string, of the executable file in use by this program space. The executable file is the file that GDB will invoke in order to start an inferior when using a native target. The file name within this attribute is updated by the `exec-file' and `file' commands. If no executable is currently set within this `Progspace' then this attribute contains `None'. If the `Progspace' is invalid, i.e., when `Progspace.is_valid()' returns `False', then attempting to access this attribute will raise a `RuntimeError' exception. -- Variable: Progspace.pretty_printers The `pretty_printers' attribute is a list of functions. It is used to look up pretty-printers. A `Value' is passed to each function in order; if the function returns `None', then the search continues. Otherwise, the return value should be an object which is used to format the value. *Note Pretty Printing API::, for more information. -- Variable: Progspace.type_printers The `type_printers' attribute is a list of type printer objects. *Note Type Printing API::, for more information. -- Variable: Progspace.frame_filters The `frame_filters' attribute is a dictionary of frame filter objects. *Note Frame Filter API::, for more information. -- Variable: Progspace.missing_debug_handlers The `missing_debug_handlers' attribute is a list of the missing debug handler objects for this program space. *Note Missing Debug Info In Python::, for more information. A program space has the following methods: -- Function: Progspace.block_for_pc (pc) Return the innermost `gdb.Block' containing the given PC value. If the block cannot be found for the PC value specified, the function will return `None'. -- Function: Progspace.find_pc_line (pc) Return the `gdb.Symtab_and_line' object corresponding to the PC value. *Note Symbol Tables In Python::. If an invalid value of PC is passed as an argument, then the `symtab' and `line' attributes of the returned `gdb.Symtab_and_line' object will be `None' and 0 respectively. -- Function: Progspace.is_valid () Returns `True' if the `gdb.Progspace' object is valid, `False' if not. A `gdb.Progspace' object can become invalid if the program space file it refers to is not referenced by any inferior. All other `gdb.Progspace' methods will throw an exception if it is invalid at the time the method is called. -- Function: Progspace.objfiles () Return a sequence of all the objfiles referenced by this program space. *Note Objfiles In Python::. -- Function: Progspace.solib_name (address) Return the name of the shared library holding the given ADDRESS as a string, or `None'. -- Function: Progspace.objfile_for_address (address) Return the `gdb.Objfile' holding the given address, or `None' if no objfile covers it. One may add arbitrary attributes to `gdb.Progspace' objects in the usual Python way. This is useful if, for example, one needs to do some extra record keeping associated with the program space. *Note choosing attribute names::, for guidance on selecting a suitable name for new attributes. In this contrived example, we want to perform some processing when an objfile with a certain symbol is loaded, but we only want to do this once because it is expensive. To achieve this we record the results with the program space because we can't predict when the desired objfile will be loaded. (gdb) python def clear_objfiles_handler(event): event.progspace.expensive_computation = None def expensive(symbol): """A mock routine to perform an "expensive" computation on symbol.""" print ("Computing the answer to the ultimate question ...") return 42 def new_objfile_handler(event): objfile = event.new_objfile progspace = objfile.progspace if not hasattr(progspace, 'expensive_computation') or \ progspace.expensive_computation is None: # We use 'main' for the symbol to keep the example simple. # Note: There's no current way to constrain the lookup # to one objfile. symbol = gdb.lookup_global_symbol('main') if symbol is not None: progspace.expensive_computation = expensive(symbol) gdb.events.clear_objfiles.connect(clear_objfiles_handler) gdb.events.new_objfile.connect(new_objfile_handler) end (gdb) file /tmp/hello Reading symbols from /tmp/hello... Computing the answer to the ultimate question ... (gdb) python print(gdb.current_progspace().expensive_computation) 42 (gdb) run Starting program: /tmp/hello Hello. [Inferior 1 (process 4242) exited normally]  File: gdb.info, Node: Objfiles In Python, Next: Frames In Python, Prev: Progspaces In Python, Up: Python API 23.3.2.27 Objfiles In Python ............................ GDB loads symbols for an inferior from various symbol-containing files (*note Files::). These include the primary executable file, any shared libraries used by the inferior, and any separate debug info files (*note Separate Debug Files::). GDB calls these symbol-containing files "objfiles". The following objfile-related functions are available in the `gdb' module: -- Function: gdb.current_objfile () When auto-loading a Python script (*note Python Auto-loading::), GDB sets the "current objfile" to the corresponding objfile. This function returns the current objfile. If there is no current objfile, this function returns `None'. -- Function: gdb.objfiles () Return a sequence of objfiles referenced by the current program space. *Note Objfiles In Python::, and *Note Progspaces In Python::. This is identical to `gdb.selected_inferior().progspace.objfiles()' and is included for historical compatibility. -- Function: gdb.lookup_objfile (name [, by_build_id]) Look up NAME, a file name or build ID, in the list of objfiles for the current program space (*note Progspaces In Python::). If the objfile is not found throw the Python `ValueError' exception. If NAME is a relative file name, then it will match any source file name with the same trailing components. For example, if NAME is `gcc/expr.c', then it will match source file name of `/build/trunk/gcc/expr.c', but not `/build/trunk/libcpp/expr.c' or `/build/trunk/gcc/x-expr.c'. If BY_BUILD_ID is provided and is `True' then NAME is the build ID of the objfile. Otherwise, NAME is a file name. This is supported only on some operating systems, notably those which use the ELF format for binary files and the GNU Binutils. For more details about this feature, see the description of the `--build-id' command-line option in *Note Command Line Options: (ld)Options. Each objfile is represented by an instance of the `gdb.Objfile' class. -- Variable: Objfile.filename The file name of the objfile as a string, with symbolic links resolved. The value is `None' if the objfile is no longer valid. See the `gdb.Objfile.is_valid' method, described below. -- Variable: Objfile.username The file name of the objfile as specified by the user as a string. The value is `None' if the objfile is no longer valid. See the `gdb.Objfile.is_valid' method, described below. -- Variable: Objfile.is_file An objfile often comes from an ordinary file, but in some cases it may be constructed from the contents of memory. This attribute is `True' for file-backed objfiles, and `False' for other kinds. -- Variable: Objfile.owner For separate debug info objfiles this is the corresponding `gdb.Objfile' object that debug info is being provided for. Otherwise this is `None'. Separate debug info objfiles are added with the `gdb.Objfile.add_separate_debug_file' method, described below. -- Variable: Objfile.build_id The build ID of the objfile as a string. If the objfile does not have a build ID then the value is `None'. This is supported only on some operating systems, notably those which use the ELF format for binary files and the GNU Binutils. For more details about this feature, see the description of the `--build-id' command-line option in *Note Command Line Options: (ld)Options. -- Variable: Objfile.progspace The containing program space of the objfile as a `gdb.Progspace' object. *Note Progspaces In Python::. -- Variable: Objfile.pretty_printers The `pretty_printers' attribute is a list of functions. It is used to look up pretty-printers. A `Value' is passed to each function in order; if the function returns `None', then the search continues. Otherwise, the return value should be an object which is used to format the value. *Note Pretty Printing API::, for more information. -- Variable: Objfile.type_printers The `type_printers' attribute is a list of type printer objects. *Note Type Printing API::, for more information. -- Variable: Objfile.frame_filters The `frame_filters' attribute is a dictionary of frame filter objects. *Note Frame Filter API::, for more information. One may add arbitrary attributes to `gdb.Objfile' objects in the usual Python way. This is useful if, for example, one needs to do some extra record keeping associated with the objfile. *Note choosing attribute names::, for guidance on selecting a suitable name for new attributes. In this contrived example we record the time when GDB loaded the objfile. (gdb) python import datetime def new_objfile_handler(event): # Set the time_loaded attribute of the new objfile. event.new_objfile.time_loaded = datetime.datetime.today() gdb.events.new_objfile.connect(new_objfile_handler) end (gdb) file ./hello Reading symbols from ./hello... (gdb) python print(gdb.objfiles()[0].time_loaded) 2014-10-09 11:41:36.770345 A `gdb.Objfile' object has the following methods: -- Function: Objfile.is_valid () Returns `True' if the `gdb.Objfile' object is valid, `False' if not. A `gdb.Objfile' object can become invalid if the object file it refers to is not loaded in GDB any longer. All other `gdb.Objfile' methods will throw an exception if it is invalid at the time the method is called. -- Function: Objfile.add_separate_debug_file (file) Add FILE to the list of files that GDB will search for debug information for the objfile. This is useful when the debug info has been removed from the program and stored in a separate file. GDB has built-in support for finding separate debug info files (*note Separate Debug Files::), but if the file doesn't live in one of the standard places that GDB searches then this function can be used to add a debug info file from a different place. -- Function: Objfile.lookup_global_symbol (name [, domain]) Search for a global symbol named NAME in this objfile. Optionally, the search scope can be restricted with the DOMAIN argument. The DOMAIN argument must be a domain constant defined in the `gdb' module and described in *Note Symbols In Python::. This function is similar to `gdb.lookup_global_symbol', except that the search is limited to this objfile. The result is a `gdb.Symbol' object or `None' if the symbol is not found. -- Function: Objfile.lookup_static_symbol (name [, domain]) Like `Objfile.lookup_global_symbol', but searches for a global symbol with static linkage named NAME in this objfile.  File: gdb.info, Node: Frames In Python, Next: Blocks In Python, Prev: Objfiles In Python, Up: Python API 23.3.2.28 Accessing inferior stack frames from Python ..................................................... When the debugged program stops, GDB is able to analyze its call stack (*note Stack frames: Frames.). The `gdb.Frame' class represents a frame in the stack. A `gdb.Frame' object is only valid while its corresponding frame exists in the inferior's stack. If you try to use an invalid frame object, GDB will throw a `gdb.error' exception (*note Exception Handling::). Two `gdb.Frame' objects can be compared for equality with the `==' operator, like: (gdb) python print gdb.newest_frame() == gdb.selected_frame () True The following frame-related functions are available in the `gdb' module: -- Function: gdb.selected_frame () Return the selected frame object. (*note Selecting a Frame: Selection.). -- Function: gdb.newest_frame () Return the newest frame object for the selected thread. -- Function: gdb.frame_stop_reason_string (reason) Return a string explaining the reason why GDB stopped unwinding frames, as expressed by the given REASON code (an integer, see the `unwind_stop_reason' method further down in this section). -- Function: gdb.invalidate_cached_frames GDB internally keeps a cache of the frames that have been unwound. This function invalidates this cache. This function should not generally be called by ordinary Python code. It is documented for the sake of completeness. A `gdb.Frame' object has the following methods: -- Function: Frame.is_valid () Returns true if the `gdb.Frame' object is valid, false if not. A frame object can become invalid if the frame it refers to doesn't exist anymore in the inferior. All `gdb.Frame' methods will throw an exception if it is invalid at the time the method is called. -- Function: Frame.name () Returns the function name of the frame, or `None' if it can't be obtained. -- Function: Frame.architecture () Returns the `gdb.Architecture' object corresponding to the frame's architecture. *Note Architectures In Python::. -- Function: Frame.type () Returns the type of the frame. The value can be one of: `gdb.NORMAL_FRAME' An ordinary stack frame. `gdb.DUMMY_FRAME' A fake stack frame that was created by GDB when performing an inferior function call. `gdb.INLINE_FRAME' A frame representing an inlined function. The function was inlined into a `gdb.NORMAL_FRAME' that is older than this one. `gdb.TAILCALL_FRAME' A frame representing a tail call. *Note Tail Call Frames::. `gdb.SIGTRAMP_FRAME' A signal trampoline frame. This is the frame created by the OS when it calls into a signal handler. `gdb.ARCH_FRAME' A fake stack frame representing a cross-architecture call. `gdb.SENTINEL_FRAME' This is like `gdb.NORMAL_FRAME', but it is only used for the newest frame. -- Function: Frame.unwind_stop_reason () Return an integer representing the reason why it's not possible to find more frames toward the outermost frame. Use `gdb.frame_stop_reason_string' to convert the value returned by this function to a string. The value can be one of: `gdb.FRAME_UNWIND_NO_REASON' No particular reason (older frames should be available). `gdb.FRAME_UNWIND_NULL_ID' The previous frame's analyzer returns an invalid result. This is no longer used by GDB, and is kept only for backward compatibility. `gdb.FRAME_UNWIND_OUTERMOST' This frame is the outermost. `gdb.FRAME_UNWIND_UNAVAILABLE' Cannot unwind further, because that would require knowing the values of registers or memory that have not been collected. `gdb.FRAME_UNWIND_INNER_ID' This frame ID looks like it ought to belong to a NEXT frame, but we got it for a PREV frame. Normally, this is a sign of unwinder failure. It could also indicate stack corruption. `gdb.FRAME_UNWIND_SAME_ID' This frame has the same ID as the previous one. That means that unwinding further would almost certainly give us another frame with exactly the same ID, so break the chain. Normally, this is a sign of unwinder failure. It could also indicate stack corruption. `gdb.FRAME_UNWIND_NO_SAVED_PC' The frame unwinder did not find any saved PC, but we needed one to unwind further. `gdb.FRAME_UNWIND_MEMORY_ERROR' The frame unwinder caused an error while trying to access memory. `gdb.FRAME_UNWIND_FIRST_ERROR' Any stop reason greater or equal to this value indicates some kind of error. This special value facilitates writing code that tests for errors in unwinding in a way that will work correctly even if the list of the other values is modified in future GDB versions. Using it, you could write: reason = gdb.selected_frame().unwind_stop_reason () reason_str = gdb.frame_stop_reason_string (reason) if reason >= gdb.FRAME_UNWIND_FIRST_ERROR: print ("An error occurred: %s" % reason_str) -- Function: Frame.pc () Returns the frame's resume address. -- Function: Frame.block () Return the frame's code block. *Note Blocks In Python::. If the frame does not have a block - for example, if there is no debugging information for the code in question - then this will throw an exception. -- Function: Frame.function () Return the symbol for the function corresponding to this frame. *Note Symbols In Python::. -- Function: Frame.older () Return the frame that called this frame. If this is the oldest frame, return `None'. -- Function: Frame.newer () Return the frame called by this frame. If this is the newest frame, return `None'. -- Function: Frame.find_sal () Return the frame's symtab and line object. *Note Symbol Tables In Python::. -- Function: Frame.read_register (register) Return the value of REGISTER in this frame. Returns a `Gdb.Value' object. Throws an exception if REGISTER does not exist. The REGISTER argument must be one of the following: 1. A string that is the name of a valid register (e.g., `'sp'' or `'rax''). 2. A `gdb.RegisterDescriptor' object (*note Registers In Python::). 3. A GDB internal, platform specific number. Using these numbers is supported for historic reasons, but is not recommended as future changes to GDB could change the mapping between numbers and the registers they represent, breaking any Python code that uses the platform-specific numbers. The numbers are usually found in the corresponding `PLATFORM-tdep.h' file in the GDB source tree. Using a string to access registers will be slightly slower than the other two methods as GDB must look up the mapping between name and internal register number. If performance is critical consider looking up and caching a `gdb.RegisterDescriptor' object. -- Function: Frame.read_var (variable [, block]) Return the value of VARIABLE in this frame. If the optional argument BLOCK is provided, search for the variable from that block; otherwise start at the frame's current block (which is determined by the frame's current program counter). The VARIABLE argument must be a string or a `gdb.Symbol' object; BLOCK must be a `gdb.Block' object. -- Function: Frame.select () Set this frame to be the selected frame. *Note Examining the Stack: Stack. -- Function: Frame.static_link () In some languages (e.g., Ada, but also a GNU C extension), a nested function can access the variables in the outer scope. This is done via a "static link", which is a reference from the nested frame to the appropriate outer frame. This method returns this frame's static link frame, if one exists. If there is no static link, this method returns `None'. -- Function: Frame.level () Return an integer, the stack frame level for this frame. *Note Stack Frames: Frames. -- Function: Frame.language () Return a string, the source language for this frame.  File: gdb.info, Node: Blocks In Python, Next: Symbols In Python, Prev: Frames In Python, Up: Python API 23.3.2.29 Accessing blocks from Python ...................................... In GDB, symbols are stored in blocks. A block corresponds roughly to a scope in the source code. Blocks are organized hierarchically, and are represented individually in Python as a `gdb.Block'. Blocks rely on debugging information being available. A frame has a block. Please see *Note Frames In Python::, for a more in-depth discussion of frames. The outermost block is known as the "global block". The global block typically holds public global variables and functions. The block nested just inside the global block is the "static block". The static block typically holds file-scoped variables and functions. GDB provides a method to get a block's superblock, but there is currently no way to examine the sub-blocks of a block, or to iterate over all the blocks in a symbol table (*note Symbol Tables In Python::). Here is a short example that should help explain blocks: /* This is in the global block. */ int global; /* This is in the static block. */ static int file_scope; /* 'function' is in the global block, and 'argument' is in a block nested inside of 'function'. */ int function (int argument) { /* 'local' is in a block inside 'function'. It may or may not be in the same block as 'argument'. */ int local; { /* 'inner' is in a block whose superblock is the one holding 'local'. */ int inner; /* If this call is expanded by the compiler, you may see a nested block here whose function is 'inline_function' and whose superblock is the one holding 'inner'. */ inline_function (); } } A `gdb.Block' is iterable. The iterator returns the symbols (*note Symbols In Python::) local to the block. Python programs should not assume that a specific block object will always contain a given symbol, since changes in GDB features and infrastructure may cause symbols move across blocks in a symbol table. You can also use Python's "dictionary syntax" to access variables in this block, e.g.: symbol = some_block['variable'] # symbol is of type gdb.Symbol The following block-related functions are available in the `gdb' module: -- Function: gdb.block_for_pc (pc) Return the innermost `gdb.Block' containing the given PC value. If the block cannot be found for the PC value specified, the function will return `None'. This is identical to `gdb.current_progspace().block_for_pc(pc)' and is included for historical compatibility. A `gdb.Block' object has the following methods: -- Function: Block.is_valid () Returns `True' if the `gdb.Block' object is valid, `False' if not. A block object can become invalid if the block it refers to doesn't exist anymore in the inferior. All other `gdb.Block' methods will throw an exception if it is invalid at the time the method is called. The block's validity is also checked during iteration over symbols of the block. A `gdb.Block' object has the following attributes: -- Variable: Block.start The start address of the block. This attribute is not writable. -- Variable: Block.end One past the last address that appears in the block. This attribute is not writable. -- Variable: Block.function The name of the block represented as a `gdb.Symbol'. If the block is not named, then this attribute holds `None'. This attribute is not writable. For ordinary function blocks, the superblock is the static block. However, you should note that it is possible for a function block to have a superblock that is not the static block - for instance this happens for an inlined function. -- Variable: Block.superblock The block containing this block. If this parent block does not exist, this attribute holds `None'. This attribute is not writable. -- Variable: Block.global_block The global block associated with this block. This attribute is not writable. -- Variable: Block.static_block The static block associated with this block. This attribute is not writable. -- Variable: Block.is_global `True' if the `gdb.Block' object is a global block, `False' if not. This attribute is not writable. -- Variable: Block.is_static `True' if the `gdb.Block' object is a static block, `False' if not. This attribute is not writable.  File: gdb.info, Node: Symbols In Python, Next: Symbol Tables In Python, Prev: Blocks In Python, Up: Python API 23.3.2.30 Python representation of Symbols .......................................... GDB represents every variable, function and type as an entry in a symbol table. *Note Examining the Symbol Table: Symbols. Similarly, Python represents these symbols in GDB with the `gdb.Symbol' object. The following symbol-related functions are available in the `gdb' module: -- Function: gdb.lookup_symbol (name [, block [, domain]]) This function searches for a symbol by name. The search scope can be restricted to the parameters defined in the optional domain and block arguments. NAME is the name of the symbol. It must be a string. The optional BLOCK argument restricts the search to symbols visible in that BLOCK. The BLOCK argument must be a `gdb.Block' object. If omitted, the block for the current frame is used. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the `gdb' module and described later in this chapter. The result is a tuple of two elements. The first element is a `gdb.Symbol' object or `None' if the symbol is not found. If the symbol is found, the second element is `True' if the symbol is a field of a method's object (e.g., `this' in C++), otherwise it is `False'. If the symbol is not found, the second element is `False'. -- Function: gdb.lookup_global_symbol (name [, domain]) This function searches for a global symbol by name. The search scope can be restricted to by the domain argument. NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the `gdb' module and described later in this chapter. The result is a `gdb.Symbol' object or `None' if the symbol is not found. -- Function: gdb.lookup_static_symbol (name [, domain]) This function searches for a global symbol with static linkage by name. The search scope can be restricted to by the domain argument. NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the `gdb' module and described later in this chapter. The result is a `gdb.Symbol' object or `None' if the symbol is not found. Note that this function will not find function-scoped static variables. To look up such variables, iterate over the variables of the function's `gdb.Block' and check that `block.addr_class' is `gdb.SYMBOL_LOC_STATIC'. There can be multiple global symbols with static linkage with the same name. This function will only return the first matching symbol that it finds. Which symbol is found depends on where GDB is currently stopped, as GDB will first search for matching symbols in the current object file, and then search all other object files. If the application is not yet running then GDB will search all object files in the order they appear in the debug information. -- Function: gdb.lookup_static_symbols (name [, domain]) Similar to `gdb.lookup_static_symbol', this function searches for global symbols with static linkage by name, and optionally restricted by the domain argument. However, this function returns a list of all matching symbols found, not just the first one. NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the `gdb' module and described later in this chapter. The result is a list of `gdb.Symbol' objects which could be empty if no matching symbols were found. Note that this function will not find function-scoped static variables. To look up such variables, iterate over the variables of the function's `gdb.Block' and check that `block.addr_class' is `gdb.SYMBOL_LOC_STATIC'. A `gdb.Symbol' object has the following attributes: -- Variable: Symbol.type The type of the symbol or `None' if no type is recorded. This attribute is represented as a `gdb.Type' object. *Note Types In Python::. This attribute is not writable. -- Variable: Symbol.symtab The symbol table in which the symbol appears. This attribute is represented as a `gdb.Symtab' object. *Note Symbol Tables In Python::. This attribute is not writable. -- Variable: Symbol.line The line number in the source code at which the symbol was defined. This is an integer. -- Variable: Symbol.name The name of the symbol as a string. This attribute is not writable. -- Variable: Symbol.linkage_name The name of the symbol, as used by the linker (i.e., may be mangled). This attribute is not writable. -- Variable: Symbol.print_name The name of the symbol in a form suitable for output. This is either `name' or `linkage_name', depending on whether the user asked GDB to display demangled or mangled names. -- Variable: Symbol.addr_class The address class of the symbol. This classifies how to find the value of a symbol. Each address class is a constant defined in the `gdb' module and described later in this chapter. -- Variable: Symbol.needs_frame This is `True' if evaluating this symbol's value requires a frame (*note Frames In Python::) and `False' otherwise. Typically, local variables will require a frame, but other symbols will not. -- Variable: Symbol.is_argument `True' if the symbol is an argument of a function. -- Variable: Symbol.is_constant `True' if the symbol is a constant. -- Variable: Symbol.is_function `True' if the symbol is a function or a method. -- Variable: Symbol.is_variable `True' if the symbol is a variable, as opposed to something like a function or type. Note that this also returns `False' for arguments. A `gdb.Symbol' object has the following methods: -- Function: Symbol.is_valid () Returns `True' if the `gdb.Symbol' object is valid, `False' if not. A `gdb.Symbol' object can become invalid if the symbol it refers to does not exist in GDB any longer. All other `gdb.Symbol' methods will throw an exception if it is invalid at the time the method is called. -- Function: Symbol.value ([frame]) Compute the value of the symbol, as a `gdb.Value'. For functions, this computes the address of the function, cast to the appropriate type. If the symbol requires a frame in order to compute its value, then FRAME must be given. If FRAME is not given, or if FRAME is invalid, then this method will throw an exception. The available domain categories in `gdb.Symbol' are represented as constants in the `gdb' module: `gdb.SYMBOL_UNDEF_DOMAIN' This is used when a domain has not been discovered or none of the following domains apply. This usually indicates an error either in the symbol information or in GDB's handling of symbols. `gdb.SYMBOL_VAR_DOMAIN' This domain contains variables. `gdb.SYMBOL_FUNCTION_DOMAIN' This domain contains functions. `gdb.SYMBOL_TYPE_DOMAIN' This domain contains types. In a C-like language, types using a tag (the name appearing after a `struct', `union', or `enum' keyword) will not appear here; in other languages, all types are in this domain. `gdb.SYMBOL_STRUCT_DOMAIN' This domain holds struct, union and enum tag names. This domain is only used for C-like languages. For example, in this code: struct type_one { int x; }; typedef struct type_one type_two; Here `type_one' will be in `SYMBOL_STRUCT_DOMAIN', but `type_two' will be in `SYMBOL_TYPE_DOMAIN'. `gdb.SYMBOL_LABEL_DOMAIN' This domain contains names of labels (for gotos). `gdb.SYMBOL_MODULE_DOMAIN' This domain contains names of Fortran module types. `gdb.SYMBOL_COMMON_BLOCK_DOMAIN' This domain contains names of Fortran common blocks. When searching for a symbol, the desired domain constant can be passed verbatim to the lookup function. For example: symbol = gdb.lookup_symbol ("name", domain=gdb.SYMBOL_VAR_DOMAIN) For more complex searches, there is a corresponding set of constants, each named after one of the preceding constants, but with the `SEARCH' prefix replacing the `SYMBOL' prefix; for example, `SEARCH_LABEL_DOMAIN'. These may be or'd together to form a search constant, e.g.: symbol = gdb.lookup_symbol ("name", domain=gdb.SEARCH_VAR_DOMAIN | gdb.SEARCH_TYPE_DOMAIN) The available address class categories in `gdb.Symbol' are represented as constants in the `gdb' module: `gdb.SYMBOL_LOC_UNDEF' If this is returned by address class, it indicates an error either in the symbol information or in GDB's handling of symbols. `gdb.SYMBOL_LOC_CONST' Value is constant int. `gdb.SYMBOL_LOC_STATIC' Value is at a fixed address. `gdb.SYMBOL_LOC_REGISTER' Value is in a register. `gdb.SYMBOL_LOC_ARG' Value is an argument. This value is at the offset stored within the symbol inside the frame's argument list. `gdb.SYMBOL_LOC_REF_ARG' Value address is stored in the frame's argument list. Just like `LOC_ARG' except that the value's address is stored at the offset, not the value itself. `gdb.SYMBOL_LOC_REGPARM_ADDR' Value is a specified register. Just like `LOC_REGISTER' except the register holds the address of the argument instead of the argument itself. `gdb.SYMBOL_LOC_LOCAL' Value is a local variable. `gdb.SYMBOL_LOC_TYPEDEF' Value not used. Symbols in the domain `SYMBOL_STRUCT_DOMAIN' all have this class. `gdb.SYMBOL_LOC_LABEL' Value is a label. `gdb.SYMBOL_LOC_BLOCK' Value is a block. `gdb.SYMBOL_LOC_CONST_BYTES' Value is a byte-sequence. `gdb.SYMBOL_LOC_UNRESOLVED' Value is at a fixed address, but the address of the variable has to be determined from the minimal symbol table whenever the variable is referenced. `gdb.SYMBOL_LOC_OPTIMIZED_OUT' The value does not actually exist in the program. `gdb.SYMBOL_LOC_COMPUTED' The value's address is a computed location. `gdb.SYMBOL_LOC_COMMON_BLOCK' The value's address is a symbol. This is only used for Fortran common blocks.  File: gdb.info, Node: Symbol Tables In Python, Next: Line Tables In Python, Prev: Symbols In Python, Up: Python API 23.3.2.31 Symbol table representation in Python ............................................... Access to symbol table data maintained by GDB on the inferior is exposed to Python via two objects: `gdb.Symtab_and_line' and `gdb.Symtab'. Symbol table and line data for a frame is returned from the `find_sal' method in `gdb.Frame' object. *Note Frames In Python::. For more information on GDB's symbol table management, see *Note Examining the Symbol Table: Symbols, for more information. A `gdb.Symtab_and_line' object has the following attributes: -- Variable: Symtab_and_line.symtab The symbol table object (`gdb.Symtab') for this frame. This attribute is not writable. -- Variable: Symtab_and_line.pc Indicates the start of the address range occupied by code for the current source line. This attribute is not writable. -- Variable: Symtab_and_line.last Indicates the end of the address range occupied by code for the current source line. This attribute is not writable. -- Variable: Symtab_and_line.line Indicates the current line number for this object. This attribute is not writable. A `gdb.Symtab_and_line' object has the following methods: -- Function: Symtab_and_line.is_valid () Returns `True' if the `gdb.Symtab_and_line' object is valid, `False' if not. A `gdb.Symtab_and_line' object can become invalid if the Symbol table and line object it refers to does not exist in GDB any longer. All other `gdb.Symtab_and_line' methods will throw an exception if it is invalid at the time the method is called. A `gdb.Symtab' object has the following attributes: -- Variable: Symtab.filename The symbol table's source filename. This attribute is not writable. -- Variable: Symtab.objfile The symbol table's backing object file. *Note Objfiles In Python::. This attribute is not writable. -- Variable: Symtab.producer The name and possibly version number of the program that compiled the code in the symbol table. The contents of this string is up to the compiler. If no producer information is available then `None' is returned. This attribute is not writable. A `gdb.Symtab' object has the following methods: -- Function: Symtab.is_valid () Returns `True' if the `gdb.Symtab' object is valid, `False' if not. A `gdb.Symtab' object can become invalid if the symbol table it refers to does not exist in GDB any longer. All other `gdb.Symtab' methods will throw an exception if it is invalid at the time the method is called. -- Function: Symtab.fullname () Return the symbol table's source absolute file name. -- Function: Symtab.global_block () Return the global block of the underlying symbol table. *Note Blocks In Python::. -- Function: Symtab.static_block () Return the static block of the underlying symbol table. *Note Blocks In Python::. -- Function: Symtab.linetable () Return the line table associated with the symbol table. *Note Line Tables In Python::.  File: gdb.info, Node: Line Tables In Python, Next: Breakpoints In Python, Prev: Symbol Tables In Python, Up: Python API 23.3.2.32 Manipulating line tables using Python ............................................... Python code can request and inspect line table information from a symbol table that is loaded in GDB. A line table is a mapping of source lines to their executable locations in memory. To acquire the line table information for a particular symbol table, use the `linetable' function (*note Symbol Tables In Python::). A `gdb.LineTable' is iterable. The iterator returns `LineTableEntry' objects that correspond to the source line and address for each line table entry. `LineTableEntry' objects have the following attributes: -- Variable: LineTableEntry.line The source line number for this line table entry. This number corresponds to the actual line of source. This attribute is not writable. -- Variable: LineTableEntry.pc The address that is associated with the line table entry where the executable code for that source line resides in memory. This attribute is not writable. As there can be multiple addresses for a single source line, you may receive multiple `LineTableEntry' objects with matching `line' attributes, but with different `pc' attributes. The iterator is sorted in ascending `pc' order. Here is a small example illustrating iterating over a line table. symtab = gdb.selected_frame().find_sal().symtab linetable = symtab.linetable() for line in linetable: print ("Line: "+str(line.line)+" Address: "+hex(line.pc)) This will have the following output: Line: 33 Address: 0x4005c8L Line: 37 Address: 0x4005caL Line: 39 Address: 0x4005d2L Line: 40 Address: 0x4005f8L Line: 42 Address: 0x4005ffL Line: 44 Address: 0x400608L Line: 42 Address: 0x40060cL Line: 45 Address: 0x400615L In addition to being able to iterate over a `LineTable', it also has the following direct access methods: -- Function: LineTable.line (line) Return a Python `Tuple' of `LineTableEntry' objects for any entries in the line table for the given LINE, which specifies the source code line. If there are no entries for that source code LINE, the Python `None' is returned. -- Function: LineTable.has_line (line) Return a Python `Boolean' indicating whether there is an entry in the line table for this source line. Return `True' if an entry is found, or `False' if not. -- Function: LineTable.source_lines () Return a Python `List' of the source line numbers in the symbol table. Only lines with executable code locations are returned. The contents of the `List' will just be the source line entries represented as Python `Long' values.  File: gdb.info, Node: Breakpoints In Python, Next: Finish Breakpoints in Python, Prev: Line Tables In Python, Up: Python API 23.3.2.33 Manipulating breakpoints using Python ............................................... Python code can manipulate breakpoints via the `gdb.Breakpoint' class. A breakpoint can be created using one of the two forms of the `gdb.Breakpoint' constructor. The first one accepts a string like one would pass to the `break' (*note Setting Breakpoints: Set Breaks.) and `watch' (*note Setting Watchpoints: Set Watchpoints.) commands, and can be used to create both breakpoints and watchpoints. The second accepts separate Python arguments similar to *Note Explicit Locations::, and can only be used to create breakpoints. -- Function: Breakpoint.__init__ (spec [, type ][, wp_class ][, internal ][, temporary ][, qualified ]) Create a new breakpoint according to SPEC, which is a string naming the location of a breakpoint, or an expression that defines a watchpoint. The string should describe a location in a format recognized by the `break' command (*note Setting Breakpoints: Set Breaks.) or, in the case of a watchpoint, by the `watch' command (*note Setting Watchpoints: Set Watchpoints.). The optional TYPE argument specifies the type of the breakpoint to create, as defined below. The optional WP_CLASS argument defines the class of watchpoint to create, if TYPE is `gdb.BP_WATCHPOINT'. If WP_CLASS is omitted, it defaults to `gdb.WP_WRITE'. The optional INTERNAL argument allows the breakpoint to become invisible to the user. The breakpoint will neither be reported when created, nor will it be listed in the output from `info breakpoints' (but will be listed with the `maint info breakpoints' command). The optional TEMPORARY argument makes the breakpoint a temporary breakpoint. Temporary breakpoints are deleted after they have been hit. Any further access to the Python breakpoint after it has been hit will result in a runtime error (as that breakpoint has now been automatically deleted). The optional QUALIFIED argument is a boolean that allows interpreting the function passed in `spec' as a fully-qualified name. It is equivalent to `break''s `-qualified' flag (*note Linespec Locations:: and *Note Explicit Locations::). -- Function: Breakpoint.__init__ ([ source ][, function ][, label ][, line ], ][ internal ][, temporary ][, qualified ]) This second form of creating a new breakpoint specifies the explicit location (*note Explicit Locations::) using keywords. The new breakpoint will be created in the specified source file SOURCE, at the specified FUNCTION, LABEL and LINE. INTERNAL, TEMPORARY and QUALIFIED have the same usage as explained previously. The available types are represented by constants defined in the `gdb' module: `gdb.BP_BREAKPOINT' Normal code breakpoint. `gdb.BP_HARDWARE_BREAKPOINT' Hardware assisted code breakpoint. `gdb.BP_WATCHPOINT' Watchpoint breakpoint. `gdb.BP_HARDWARE_WATCHPOINT' Hardware assisted watchpoint. `gdb.BP_READ_WATCHPOINT' Hardware assisted read watchpoint. `gdb.BP_ACCESS_WATCHPOINT' Hardware assisted access watchpoint. `gdb.BP_CATCHPOINT' Catchpoint. Currently, this type can't be used when creating `gdb.Breakpoint' objects, but will be present in `gdb.Breakpoint' objects reported from `gdb.BreakpointEvent's (*note Events In Python::). The available watchpoint types are represented by constants defined in the `gdb' module: `gdb.WP_READ' Read only watchpoint. `gdb.WP_WRITE' Write only watchpoint. `gdb.WP_ACCESS' Read/Write watchpoint. -- Function: Breakpoint.stop (self) The `gdb.Breakpoint' class can be sub-classed and, in particular, you may choose to implement the `stop' method. If this method is defined in a sub-class of `gdb.Breakpoint', it will be called when the inferior reaches any location of a breakpoint which instantiates that sub-class. If the method returns `True', the inferior will be stopped at the location of the breakpoint, otherwise the inferior will continue. If there are multiple breakpoints at the same location with a `stop' method, each one will be called regardless of the return status of the previous. This ensures that all `stop' methods have a chance to execute at that location. In this scenario if one of the methods returns `True' but the others return `False', the inferior will still be stopped. You should not alter the execution state of the inferior (i.e., step, next, etc.), alter the current frame context (i.e., change the current active frame), or alter, add or delete any breakpoint. As a general rule, you should not alter any data within GDB or the inferior at this time. Example `stop' implementation: class MyBreakpoint (gdb.Breakpoint): def stop (self): inf_val = gdb.parse_and_eval("foo") if inf_val == 3: return True return False -- Function: Breakpoint.is_valid () Return `True' if this `Breakpoint' object is valid, `False' otherwise. A `Breakpoint' object can become invalid if the user deletes the breakpoint. In this case, the object still exists, but the underlying breakpoint does not. In the cases of watchpoint scope, the watchpoint remains valid even if execution of the inferior leaves the scope of that watchpoint. -- Function: Breakpoint.delete () Permanently deletes the GDB breakpoint. This also invalidates the Python `Breakpoint' object. Any further access to this object's attributes or methods will raise an error. -- Variable: Breakpoint.enabled This attribute is `True' if the breakpoint is enabled, and `False' otherwise. This attribute is writable. You can use it to enable or disable the breakpoint. -- Variable: Breakpoint.silent This attribute is `True' if the breakpoint is silent, and `False' otherwise. This attribute is writable. Note that a breakpoint can also be silent if it has commands and the first command is `silent'. This is not reported by the `silent' attribute. -- Variable: Breakpoint.pending This attribute is `True' if the breakpoint is pending, and `False' otherwise. *Note Set Breaks::. This attribute is read-only. -- Variable: Breakpoint.thread If the breakpoint is thread-specific (*note Thread-Specific Breakpoints::), this attribute holds the thread's global id. If the breakpoint is not thread-specific, this attribute is `None'. This attribute is writable. Only one of `Breakpoint.thread' or `Breakpoint.inferior' can be set to a valid id at any time, that is, a breakpoint can be thread specific, or inferior specific, but not both. -- Variable: Breakpoint.inferior If the breakpoint is inferior-specific (*note Inferior-Specific Breakpoints::), this attribute holds the inferior's id. If the breakpoint is not inferior-specific, this attribute is `None'. This attribute can be written for breakpoints of type `gdb.BP_BREAKPOINT' and `gdb.BP_HARDWARE_BREAKPOINT'. -- Variable: Breakpoint.task If the breakpoint is Ada task-specific, this attribute holds the Ada task id. If the breakpoint is not task-specific (or the underlying language is not Ada), this attribute is `None'. This attribute is writable. -- Variable: Breakpoint.ignore_count This attribute holds the ignore count for the breakpoint, an integer. This attribute is writable. -- Variable: Breakpoint.number This attribute holds the breakpoint's number -- the identifier used by the user to manipulate the breakpoint. This attribute is not writable. -- Variable: Breakpoint.type This attribute holds the breakpoint's type -- the identifier used to determine the actual breakpoint type or use-case. This attribute is not writable. -- Variable: Breakpoint.visible This attribute tells whether the breakpoint is visible to the user when set, or when the `info breakpoints' command is run. This attribute is not writable. -- Variable: Breakpoint.temporary This attribute indicates whether the breakpoint was created as a temporary breakpoint. Temporary breakpoints are automatically deleted after that breakpoint has been hit. Access to this attribute, and all other attributes and functions other than the `is_valid' function, will result in an error after the breakpoint has been hit (as it has been automatically deleted). This attribute is not writable. -- Variable: Breakpoint.hit_count This attribute holds the hit count for the breakpoint, an integer. This attribute is writable, but currently it can only be set to zero. -- Variable: Breakpoint.location This attribute holds the location of the breakpoint, as specified by the user. It is a string. If the breakpoint does not have a location (that is, it is a watchpoint) the attribute's value is `None'. This attribute is not writable. -- Variable: Breakpoint.locations Get the most current list of breakpoint locations that are inserted for this breakpoint, with elements of type `gdb.BreakpointLocation' (described below). This functionality matches that of the `info breakpoint' command (*note Set Breaks::), in that it only retrieves the most current list of locations, thus the list itself when returned is not updated behind the scenes. This attribute is not writable. -- Variable: Breakpoint.expression This attribute holds a breakpoint expression, as specified by the user. It is a string. If the breakpoint does not have an expression (the breakpoint is not a watchpoint) the attribute's value is `None'. This attribute is not writable. -- Variable: Breakpoint.condition This attribute holds the condition of the breakpoint, as specified by the user. It is a string. If there is no condition, this attribute's value is `None'. This attribute is writable. -- Variable: Breakpoint.commands This attribute holds the commands attached to the breakpoint. If there are commands, this attribute's value is a string holding all the commands, separated by newlines. If there are no commands, this attribute is `None'. This attribute is writable. Breakpoint Locations -------------------- A breakpoint location is one of the actual places where a breakpoint has been set, represented in the Python API by the `gdb.BreakpointLocation' type. This type is never instantiated by the user directly, but is retrieved from `Breakpoint.locations' which returns a list of breakpoint locations where it is currently set. Breakpoint locations can become invalid if new symbol files are loaded or dynamically loaded libraries are closed. Accessing the attributes of an invalidated breakpoint location will throw a `RuntimeError' exception. Access the `Breakpoint.locations' attribute again to retrieve the new and valid breakpoints location list. -- Variable: BreakpointLocation.source This attribute returns the source file path and line number where this location was set. The type of the attribute is a tuple of STRING and LONG. If the breakpoint location doesn't have a source location, it returns None, which is the case for watchpoints and catchpoints. This will throw a `RuntimeError' exception if the location has been invalidated. This attribute is not writable. -- Variable: BreakpointLocation.address This attribute returns the address where this location was set. This attribute is of type long. This will throw a `RuntimeError' exception if the location has been invalidated. This attribute is not writable. -- Variable: BreakpointLocation.enabled This attribute holds the value for whether or not this location is enabled. This attribute is writable (boolean). This will throw a `RuntimeError' exception if the location has been invalidated. -- Variable: BreakpointLocation.owner This attribute holds a reference to the `gdb.Breakpoint' owner object, from which this `gdb.BreakpointLocation' was retrieved from. This will throw a `RuntimeError' exception if the location has been invalidated. This attribute is not writable. -- Variable: BreakpointLocation.function This attribute gets the name of the function where this location was set. If no function could be found this attribute returns `None'. This will throw a `RuntimeError' exception if the location has been invalidated. This attribute is not writable. -- Variable: BreakpointLocation.fullname This attribute gets the full name of where this location was set. If no full name could be found, this attribute returns `None'. This will throw a `RuntimeError' exception if the location has been invalidated. This attribute is not writable. -- Variable: BreakpointLocation.thread_groups This attribute gets the thread groups it was set in. It returns a `List' of the thread group ID's. This will throw a `RuntimeError' exception if the location has been invalidated. This attribute is not writable.  File: gdb.info, Node: Finish Breakpoints in Python, Next: Lazy Strings In Python, Prev: Breakpoints In Python, Up: Python API 23.3.2.34 Finish Breakpoints ............................ A finish breakpoint is a temporary breakpoint set at the return address of a frame, based on the `finish' command. `gdb.FinishBreakpoint' extends `gdb.Breakpoint'. The underlying breakpoint will be disabled and deleted when the execution will run out of the breakpoint scope (i.e. `Breakpoint.stop' or `FinishBreakpoint.out_of_scope' triggered). Finish breakpoints are thread specific and must be create with the right thread selected. -- Function: FinishBreakpoint.__init__ ([frame] [, internal]) Create a finish breakpoint at the return address of the `gdb.Frame' object FRAME. If FRAME is not provided, this defaults to the newest frame. The optional INTERNAL argument allows the breakpoint to become invisible to the user. *Note Breakpoints In Python::, for further details about this argument. -- Function: FinishBreakpoint.out_of_scope (self) In some circumstances (e.g. `longjmp', C++ exceptions, GDB `return' command, ...), a function may not properly terminate, and thus never hit the finish breakpoint. When GDB notices such a situation, the `out_of_scope' callback will be triggered. You may want to sub-class `gdb.FinishBreakpoint' and override this method: class MyFinishBreakpoint (gdb.FinishBreakpoint) def stop (self): print ("normal finish") return True def out_of_scope (): print ("abnormal finish") -- Variable: FinishBreakpoint.return_value When GDB is stopped at a finish breakpoint and the frame used to build the `gdb.FinishBreakpoint' object had debug symbols, this attribute will contain a `gdb.Value' object corresponding to the return value of the function. The value will be `None' if the function return type is `void' or if the return value was not computable. This attribute is not writable.  File: gdb.info, Node: Lazy Strings In Python, Next: Architectures In Python, Prev: Finish Breakpoints in Python, Up: Python API 23.3.2.35 Python representation of lazy strings ............................................... A "lazy string" is a string whose contents is not retrieved or encoded until it is needed. A `gdb.LazyString' is represented in GDB as an `address' that points to a region of memory, an `encoding' that will be used to encode that region of memory, and a `length' to delimit the region of memory that represents the string. The difference between a `gdb.LazyString' and a string wrapped within a `gdb.Value' is that a `gdb.LazyString' will be treated differently by GDB when printing. A `gdb.LazyString' is retrieved and encoded during printing, while a `gdb.Value' wrapping a string is immediately retrieved and encoded on creation. A `gdb.LazyString' object has the following functions: -- Function: LazyString.value () Convert the `gdb.LazyString' to a `gdb.Value'. This value will point to the string in memory, but will lose all the delayed retrieval, encoding and handling that GDB applies to a `gdb.LazyString'. -- Variable: LazyString.address This attribute holds the address of the string. This attribute is not writable. -- Variable: LazyString.length This attribute holds the length of the string in characters. If the length is -1, then the string will be fetched and encoded up to the first null of appropriate width. This attribute is not writable. -- Variable: LazyString.encoding This attribute holds the encoding that will be applied to the string when the string is printed by GDB. If the encoding is not set, or contains an empty string, then GDB will select the most appropriate encoding when the string is printed. This attribute is not writable. -- Variable: LazyString.type This attribute holds the type that is represented by the lazy string's type. For a lazy string this is a pointer or array type. To resolve this to the lazy string's character type, use the type's `target' method. *Note Types In Python::. This attribute is not writable.  File: gdb.info, Node: Architectures In Python, Next: Registers In Python, Prev: Lazy Strings In Python, Up: Python API 23.3.2.36 Python representation of architectures ................................................ GDB uses architecture specific parameters and artifacts in a number of its various computations. An architecture is represented by an instance of the `gdb.Architecture' class. A `gdb.Architecture' class has the following methods: -- Function: Architecture.name () Return the name (string value) of the architecture. -- Function: Architecture.disassemble (start_pc [, end_pc [, count]]) Return a list of disassembled instructions starting from the memory address START_PC. The optional arguments END_PC and COUNT determine the number of instructions in the returned list. If both the optional arguments END_PC and COUNT are specified, then a list of at most COUNT disassembled instructions whose start address falls in the closed memory address interval from START_PC to END_PC are returned. If END_PC is not specified, but COUNT is specified, then COUNT number of instructions starting from the address START_PC are returned. If COUNT is not specified but END_PC is specified, then all instructions whose start address falls in the closed memory address interval from START_PC to END_PC are returned. If neither END_PC nor COUNT are specified, then a single instruction at START_PC is returned. For all of these cases, each element of the returned list is a Python `dict' with the following string keys: `addr' The value corresponding to this key is a Python long integer capturing the memory address of the instruction. `asm' The value corresponding to this key is a string value which represents the instruction with assembly language mnemonics. The assembly language flavor used is the same as that specified by the current CLI variable `disassembly-flavor'. *Note Machine Code::. `length' The value corresponding to this key is the length (integer value) of the instruction in bytes. -- Function: Architecture.integer_type (size [, signed]) This function looks up an integer type by its SIZE, and optionally whether or not it is signed. SIZE is the size, in bits, of the desired integer type. Only certain sizes are currently supported: 0, 8, 16, 24, 32, 64, and 128. If SIGNED is not specified, it defaults to `True'. If SIGNED is `False', the returned type will be unsigned. If the indicated type cannot be found, this function will throw a `ValueError' exception. -- Function: Architecture.registers ([ reggroup ]) Return a `gdb.RegisterDescriptorIterator' (*note Registers In Python::) for all of the registers in REGGROUP, a string that is the name of a register group. If REGGROUP is omitted, or is the empty string, then the register group `all' is assumed. -- Function: Architecture.register_groups () Return a `gdb.RegisterGroupsIterator' (*note Registers In Python::) for all of the register groups available for the `gdb.Architecture'.  File: gdb.info, Node: Registers In Python, Next: Connections In Python, Prev: Architectures In Python, Up: Python API 23.3.2.37 Registers In Python ............................. Python code can request from a `gdb.Architecture' information about the set of registers available (*note `Architecture.registers': gdbpy_architecture_registers.). The register information is returned as a `gdb.RegisterDescriptorIterator', which is an iterator that in turn returns `gdb.RegisterDescriptor' objects. A `gdb.RegisterDescriptor' does not provide the value of a register (*note `Frame.read_register': gdbpy_frame_read_register. for reading a register's value), instead the `RegisterDescriptor' is a way to discover which registers are available for a particular architecture. A `gdb.RegisterDescriptor' has the following read-only properties: -- Variable: RegisterDescriptor.name The name of this register. It is also possible to lookup a register descriptor based on its name using the following `gdb.RegisterDescriptorIterator' function: -- Function: RegisterDescriptorIterator.find (name) Takes NAME as an argument, which must be a string, and returns a `gdb.RegisterDescriptor' for the register with that name, or `None' if there is no register with that name. Python code can also request from a `gdb.Architecture' information about the set of register groups available on a given architecture (*note `Architecture.register_groups': gdbpy_architecture_reggroups.). Every register can be a member of zero or more register groups. Some register groups are used internally within GDB to control things like which registers must be saved when calling into the program being debugged (*note Calling Program Functions: Calling.). Other register groups exist to allow users to easily see related sets of registers in commands like `info registers' (*note `info registers REGGROUP': info_registers_reggroup.). The register groups information is returned as a `gdb.RegisterGroupsIterator', which is an iterator that in turn returns `gdb.RegisterGroup' objects. A `gdb.RegisterGroup' object has the following read-only properties: -- Variable: RegisterGroup.name A string that is the name of this register group.  File: gdb.info, Node: Connections In Python, Next: TUI Windows In Python, Prev: Registers In Python, Up: Python API 23.3.2.38 Connections In Python ............................... GDB lets you run and debug multiple programs in a single session. Each program being debugged has a connection, the connection describes how GDB controls the program being debugged. Examples of different connection types are `native' and `remote'. *Note Inferiors Connections and Programs::. Connections in GDB are represented as instances of `gdb.TargetConnection', or as one of its sub-classes. To get a list of all connections use `gdb.connections' (*note gdb.connections: gdbpy_connections.). To get the connection for a single `gdb.Inferior' read its `gdb.Inferior.connection' attribute (*note gdb.Inferior.connection: gdbpy_inferior_connection.). Currently there is only a single sub-class of `gdb.TargetConnection', `gdb.RemoteTargetConnection', however, additional sub-classes may be added in future releases of GDB. As a result you should avoid writing code like: conn = gdb.selected_inferior().connection if type(conn) is gdb.RemoteTargetConnection: print("This is a remote target connection") as this may fail when more connection types are added. Instead, you should write: conn = gdb.selected_inferior().connection if isinstance(conn, gdb.RemoteTargetConnection): print("This is a remote target connection") A `gdb.TargetConnection' has the following method: -- Function: TargetConnection.is_valid () Return `True' if the `gdb.TargetConnection' object is valid, `False' if not. A `gdb.TargetConnection' will become invalid if the connection no longer exists within GDB, this might happen when no inferiors are using the connection, but could be delayed until the user replaces the current target. Reading any of the `gdb.TargetConnection' properties will throw an exception if the connection is invalid. A `gdb.TargetConnection' has the following read-only properties: -- Variable: TargetConnection.num An integer assigned by GDB to uniquely identify this connection. This is the same value as displayed in the `Num' column of the `info connections' command output (*note info connections: Inferiors Connections and Programs.). -- Variable: TargetConnection.type A string that describes what type of connection this is. This string will be one of the valid names that can be passed to the `target' command (*note target command: Target Commands.). -- Variable: TargetConnection.description A string that gives a short description of this target type. This is the same string that is displayed in the `Description' column of the `info connection' command output (*note info connections: Inferiors Connections and Programs.). -- Variable: TargetConnection.details An optional string that gives additional information about this connection. This attribute can be `None' if there are no additional details for this connection. An example of a connection type that might have additional details is the `remote' connection, in this case the details string can contain the `HOSTNAME:PORT' that was used to connect to the remote target. The `gdb.RemoteTargetConnection' class is a sub-class of `gdb.TargetConnection', and is used to represent `remote' and `extended-remote' connections. In addition to the attributes and methods available from the `gdb.TargetConnection' base class, a `gdb.RemoteTargetConnection' has the following method: -- Function: RemoteTargetConnection.send_packet (packet) This method sends PACKET to the remote target and returns the response. The PACKET should either be a `bytes' object, or a `Unicode' string. If PACKET is a `Unicode' string, then the string is encoded to a `bytes' object using the ASCII codec. If the string can't be encoded then an `UnicodeError' is raised. If PACKET is not a `bytes' object, or a `Unicode' string, then a `TypeError' is raised. If PACKET is empty then a `ValueError' is raised. The response is returned as a `bytes' object. If it is known that the response can be represented as a string then this can be decoded from the buffer. For example, if it is known that the response is an ASCII string: remote_connection.send_packet("some_packet").decode("ascii") The prefix, suffix, and checksum (as required by the remote serial protocol) are automatically added to the outgoing packet, and removed from the incoming packet before the contents of the reply are returned. This is equivalent to the `maintenance packet' command (*note maint packet::).  File: gdb.info, Node: TUI Windows In Python, Next: Disassembly In Python, Prev: Connections In Python, Up: Python API 23.3.2.39 Implementing new TUI windows ...................................... New TUI (*note TUI::) windows can be implemented in Python. -- Function: gdb.register_window_type (name, factory) Because TUI windows are created and destroyed depending on the layout the user chooses, new window types are implemented by registering a factory function with GDB. NAME is the name of the new window. It's an error to try to replace one of the built-in windows, but other window types can be replaced. The NAME should match the regular expression `[a-zA-Z][-_.a-zA-Z0-9]*', it is an error to try and create a window with an invalid name. FUNCTION is a factory function that is called to create the TUI window. This is called with a single argument of type `gdb.TuiWindow', described below. It should return an object that implements the TUI window protocol, also described below. As mentioned above, when a factory function is called, it is passed an object of type `gdb.TuiWindow'. This object has these methods and attributes: -- Function: TuiWindow.is_valid () This method returns `True' when this window is valid. When the user changes the TUI layout, windows no longer visible in the new layout will be destroyed. At this point, the `gdb.TuiWindow' will no longer be valid, and methods (and attributes) other than `is_valid' will throw an exception. When the TUI is disabled using `tui disable' (*note tui disable: TUI Commands.) the window is hidden rather than destroyed, but `is_valid' will still return `False' and other methods (and attributes) will still throw an exception. -- Variable: TuiWindow.width This attribute holds the width of the window. It is not writable. -- Variable: TuiWindow.height This attribute holds the height of the window. It is not writable. -- Variable: TuiWindow.title This attribute holds the window's title, a string. This is normally displayed above the window. This attribute can be modified. -- Function: TuiWindow.erase () Remove all the contents of the window. -- Function: TuiWindow.write (string [, full_window]) Write STRING to the window. STRING can contain ANSI terminal escape styling sequences; GDB will translate these as appropriate for the terminal. If the FULL_WINDOW parameter is `True', then STRING contains the full contents of the window. This is similar to calling `erase' before `write', but avoids the flickering. The factory function that you supply should return an object conforming to the TUI window protocol. These are the method that can be called on this object, which is referred to below as the "window object". The methods documented below are optional; if the object does not implement one of these methods, GDB will not attempt to call it. Additional new methods may be added to the window protocol in the future. GDB guarantees that they will begin with a lower-case letter, so you can start implementation methods with upper-case letters or underscore to avoid any future conflicts. -- Function: Window.close () When the TUI window is closed, the `gdb.TuiWindow' object will be put into an invalid state. At this time, GDB will call `close' method on the window object. After this method is called, GDB will discard any references it holds on this window object, and will no longer call methods on this object. -- Function: Window.render () In some situations, a TUI window can change size. For example, this can happen if the user resizes the terminal, or changes the layout. When this happens, GDB will call the `render' method on the window object. If your window is intended to update in response to changes in the inferior, you will probably also want to register event listeners and send output to the `gdb.TuiWindow'. -- Function: Window.hscroll (num) This is a request to scroll the window horizontally. NUM is the amount by which to scroll, with negative numbers meaning to scroll right. In the TUI model, it is the viewport that moves, not the contents. A positive argument should cause the viewport to move right, and so the content should appear to move to the left. -- Function: Window.vscroll (num) This is a request to scroll the window vertically. NUM is the amount by which to scroll, with negative numbers meaning to scroll backward. In the TUI model, it is the viewport that moves, not the contents. A positive argument should cause the viewport to move down, and so the content should appear to move up. -- Function: Window.click (x, y, button) This is called on a mouse click in this window. X and Y are the mouse coordinates inside the window (0-based, from the top left corner), and BUTTON specifies which mouse button was used, whose values can be 1 (left), 2 (middle), or 3 (right). When TUI mouse events are disabled by turning off the `tui mouse-events' setting (*note set tui mouse-events: tui-mouse-events.), then `click' will not be called.  File: gdb.info, Node: Disassembly In Python, Next: Missing Debug Info In Python, Prev: TUI Windows In Python, Up: Python API 23.3.2.40 Instruction Disassembly In Python ........................................... GDB's builtin disassembler can be extended, or even replaced, using the Python API. The disassembler related features are contained within the `gdb.disassembler' module: -- class: gdb.disassembler.DisassembleInfo Disassembly is driven by instances of this class. Each time GDB needs to disassemble an instruction, an instance of this class is created and passed to a registered disassembler. The disassembler is then responsible for disassembling an instruction and returning a result. Instances of this type are usually created within GDB, however, it is possible to create a copy of an instance of this type, see the description of `__init__' for more details. This class has the following properties and methods: -- Variable: DisassembleInfo.address A read-only integer containing the address at which GDB wishes to disassemble a single instruction. -- Variable: DisassembleInfo.architecture The `gdb.Architecture' (*note Architectures In Python::) for which GDB is currently disassembling, this property is read-only. -- Variable: DisassembleInfo.progspace The `gdb.Progspace' (*note Program Spaces In Python: Progspaces In Python.) for which GDB is currently disassembling, this property is read-only. -- Function: DisassembleInfo.is_valid () Returns `True' if the `DisassembleInfo' object is valid, `False' if not. A `DisassembleInfo' object will become invalid once the disassembly call for which the `DisassembleInfo' was created, has returned. Calling other `DisassembleInfo' methods, or accessing `DisassembleInfo' properties, will raise a `RuntimeError' exception if it is invalid. -- Function: DisassembleInfo.__init__ (info) This can be used to create a new `DisassembleInfo' object that is a copy of INFO. The copy will have the same `address', `architecture', and `progspace' values as INFO, and will become invalid at the same time as INFO. This method exists so that sub-classes of `DisassembleInfo' can be created, these sub-classes must be initialized as copies of an existing `DisassembleInfo' object, but sub-classes might choose to override the `read_memory' method, and so control what GDB sees when reading from memory (*note builtin_disassemble::). -- Function: DisassembleInfo.read_memory (length, offset) This method allows the disassembler to read the bytes of the instruction to be disassembled. The method reads LENGTH bytes, starting at OFFSET from `DisassembleInfo.address'. It is important that the disassembler read the instruction bytes using this method, rather than reading inferior memory directly, as in some cases GDB disassembles from an internal buffer rather than directly from inferior memory, calling this method handles this detail. Returns a buffer object, which behaves much like an array or a string, just as `Inferior.read_memory' does (*note Inferior.read_memory: gdbpy_inferior_read_memory.). The length of the returned buffer will always be exactly LENGTH. If GDB is unable to read the required memory then a `gdb.MemoryError' exception is raised (*note Exception Handling::). This method can be overridden by a sub-class in order to control what GDB sees when reading from memory (*note builtin_disassemble::). When overriding this method it is important to understand how `builtin_disassemble' makes use of this method. While disassembling a single instruction there could be multiple calls to this method, and the same bytes might be read multiple times. Any single call might only read a subset of the total instruction bytes. If an implementation of `read_memory' is unable to read the requested memory contents, for example, if there's a request to read from an invalid memory address, then a `gdb.MemoryError' should be raised. Raising a `MemoryError' inside `read_memory' does not automatically mean a `MemoryError' will be raised by `builtin_disassemble'. It is possible the GDB's builtin disassembler is probing to see how many bytes are available. When `read_memory' raises the `MemoryError' the builtin disassembler might be able to perform a complete disassembly with the bytes it has available, in this case `builtin_disassemble' will not itself raise a `MemoryError'. Any other exception type raised in `read_memory' will propagate back and be re-raised by `builtin_disassemble'. -- Function: DisassembleInfo.text_part (style, string) Create a new `DisassemblerTextPart' representing a piece of a disassembled instruction. STRING should be a non-empty string, and STYLE should be an appropriate style constant (*note Disassembler Style Constants::). Disassembler parts are used when creating a `DisassemblerResult' in order to represent the styling within an instruction (*note DisassemblerResult Class::). -- Function: DisassembleInfo.address_part (address) Create a new `DisassemblerAddressPart'. ADDRESS is the value of the absolute address this part represents. A `DisassemblerAddressPart' is displayed as an absolute address and an associated symbol, the address and symbol are styled appropriately. -- class: gdb.disassembler.Disassembler This is a base class from which all user implemented disassemblers must inherit. -- Function: Disassembler.__init__ (name) The constructor takes NAME, a string, which should be a short name for this disassembler. -- Function: Disassembler.__call__ (info) The `__call__' method must be overridden by sub-classes to perform disassembly. Calling `__call__' on this base class will raise a `NotImplementedError' exception. The INFO argument is an instance of `DisassembleInfo', and describes the instruction that GDB wants disassembling. If this function returns `None', this indicates to GDB that this sub-class doesn't wish to disassemble the requested instruction. GDB will then use its builtin disassembler to perform the disassembly. Alternatively, this function can return a `DisassemblerResult' that represents the disassembled instruction, this type is described in more detail below. The `__call__' method can raise a `gdb.MemoryError' exception (*note Exception Handling::) to indicate to GDB that there was a problem accessing the required memory, this will then be displayed by GDB within the disassembler output. Ideally, the only three outcomes from invoking `__call__' would be a return of `None', a successful disassembly returned in a `DisassemblerResult', or a `MemoryError' indicating that there was a problem reading memory. However, as an implementation of `__call__' could fail due to other reasons, e.g. some external resource required to perform disassembly is temporarily unavailable, then, if `__call__' raises a `GdbError', the exception will be converted to a string and printed at the end of the disassembly output, the disassembly request will then stop. Any other exception type raised by the `__call__' method is considered an error in the user code, the exception will be printed to the error stream according to the `set python print-stack' setting (*note `set python print-stack': set_python_print_stack.). -- class: gdb.disassembler.DisassemblerResult This class represents the result of disassembling a single instruction. An instance of this class will be returned from `builtin_disassemble' (*note builtin_disassemble::), and an instance of this class should be returned from `Disassembler.__call__' (*note Disassembler Class::) if an instruction was successfully disassembled. It is not possible to sub-class the `DisassemblerResult' class. The `DisassemblerResult' class has the following properties and methods: -- Function: DisassemblerResult.__init__ (length, string, parts) Initialize an instance of this class, LENGTH is the length of the disassembled instruction in bytes, which must be greater than zero. Only one of STRING or PARTS should be used to initialize a new `DisassemblerResult'; the other one should be passed the value `None'. Alternatively, the arguments can be passed by name, and the unused argument can be ignored. The STRING argument, if not `None', is a non-empty string that represents the entire disassembled instruction. Building a result object using the STRING argument does not allow for any styling information to be included in the result. GDB will style the result as a single `DisassemblerTextPart' with `STYLE_TEXT' style (*note Disassembler Styling Parts::). The PARTS argument, if not `None', is a non-empty sequence of `DisassemblerPart' objects. Each part represents a small part of the disassembled instruction along with associated styling information. A result object built using PARTS can be displayed by GDB with full styling information (*note `set style disassembler enabled': style_disassembler_enabled.). -- Variable: DisassemblerResult.length A read-only property containing the length of the disassembled instruction in bytes, this will always be greater than zero. -- Variable: DisassemblerResult.string A read-only property containing a non-empty string representing the disassembled instruction. The STRING is a representation of the disassembled instruction without any styling information. To see how the instruction will be styled use the PARTS property. If this instance was initialized using separate `DisassemblerPart' objects, the STRING property will still be valid. The STRING value is created by concatenating the `DisassemblerPart.string' values of each component part (*note Disassembler Styling Parts::). -- Variable: DisassemblerResult.parts A read-only property containing a non-empty sequence of `DisassemblerPart' objects. Each `DisassemblerPart' object contains a small part of the instruction along with information about how that part should be styled. GDB uses this information to create styled disassembler output (*note `set style disassembler enabled': style_disassembler_enabled.). If this instance was initialized using a single string rather than with a sequence of `DisassemblerPart' objects, the PARTS property will still be valid. In this case the PARTS property will hold a sequence containing a single `DisassemblerTextPart' object, the string of which will represent the entire instruction, and the style of which will be `STYLE_TEXT'. -- class: gdb.disassembler.DisassemblerPart This is a parent class from which the different part sub-classes inherit. Only instances of the sub-classes detailed below will be returned by the Python API. It is not possible to directly create instances of either this parent class, or any of the sub-classes listed below. Instances of the sub-classes listed below are created by calling `builtin_disassemble' (*note builtin_disassemble::) and are returned within the `DisassemblerResult' object, or can be created by calling the `text_part' and `address_part' methods on the `DisassembleInfo' class (*note DisassembleInfo Class::). The `DisassemblerPart' class has a single property: -- Variable: DisassemblerPart.string A read-only property that contains a non-empty string representing this part of the disassembled instruction. The string within this property doesn't include any styling information. -- class: gdb.disassembler.DisassemblerTextPart The `DisassemblerTextPart' class represents a piece of the disassembled instruction and the associated style for that piece. Instances of this class can't be created directly, instead call `DisassembleInfo.text_part' to create a new instance of this class (*note DisassembleInfo Class::). As well as the properties of its parent class, the `DisassemblerTextPart' has the following additional property: -- Variable: DisassemblerTextPart.style A read-only property that contains one of the defined style constants. GDB will use this style when styling this part of the disassembled instruction (*note Disassembler Style Constants::). -- class: gdb.disassembler.DisassemblerAddressPart The `DisassemblerAddressPart' class represents an absolute address within a disassembled instruction. Using a `DisassemblerAddressPart' instead of a `DisassemblerTextPart' with `STYLE_ADDRESS' is preferred, GDB will display the address as both an absolute address, and will look up a suitable symbol to display next to the address. Using `DisassemblerAddressPart' also ensures that user settings such as `set print max-symbolic-offset' are respected. Here is an example of an x86-64 instruction: call 0x401136 In this instruction the `0x401136 ' was generated from a single `DisassemblerAddressPart'. The `0x401136' will be styled with `STYLE_ADDRESS', and `foo' will be styled with `STYLE_SYMBOL'. The `<' and `>' will be styled as `STYLE_TEXT'. If the inclusion of the symbol name is not required then a `DisassemblerTextPart' with style `STYLE_ADDRESS' can be used instead. Instances of this class can't be created directly, instead call `DisassembleInfo.address_part' to create a new instance of this class (*note DisassembleInfo Class::). As well as the properties of its parent class, the `DisassemblerAddressPart' has the following additional property: -- Variable: DisassemblerAddressPart.address A read-only property that contains the ADDRESS passed to this object's `__init__' method. The following table lists all of the disassembler styles that are available. GDB maps these style constants onto its style settings (*note Output Styling::). In some cases, several style constants produce the same style settings, and thus will produce the same visual effect on the screen. This could change in future releases of GDB, so care should be taken to select the correct style constant to ensure correct output styling in future releases of GDB. `gdb.disassembler.STYLE_TEXT' This is the default style used by GDB when styling disassembler output. This style should be used for any parts of the instruction that don't fit any of the other styles listed below. GDB styles text with this style using its default style. `gdb.disassembler.STYLE_MNEMONIC' This style is used for styling the primary instruction mnemonic, which usually appears at, or near, the start of the disassembled instruction string. GDB styles text with this style using the `disassembler mnemonic' style setting. `gdb.disassembler.STYLE_SUB_MNEMONIC' This style is used for styling any sub-mnemonics within a disassembled instruction. A sub-mnemonic is any text within the instruction that controls the function of the instruction, but which is disjoint from the primary mnemonic (which will have styled `STYLE_MNEMONIC'). As an example, consider this AArch64 instruction: add w16, w7, w1, lsl #1 The `add' is the primary instruction mnemonic, and would be given style `STYLE_MNEMONIC', while `lsl' is the sub-mnemonic, and would be given the style `STYLE_SUB_MNEMONIC'. GDB styles text with this style using the `disassembler mnemonic' style setting. `gdb.disassembler.STYLE_ASSEMBLER_DIRECTIVE' Sometimes a series of bytes doesn't decode to a valid instruction. In this case the disassembler may choose to represent the result of disassembling using an assembler directive, for example: .word 0x1234 In this case, the `.word' would be give the `STYLE_ASSEMBLER_DIRECTIVE' style. An assembler directive is similar to a mnemonic in many ways but is something that is not part of the architecture's instruction set. GDB styles text with this style using the `disassembler mnemonic' style setting. `gdb.disassembler.STYLE_REGISTER' This style is used for styling any text that represents a register name, or register number, within a disassembled instruction. GDB styles text with this style using the `disassembler register' style setting. `gdb.disassembler.STYLE_ADDRESS' This style is used for styling numerical values that represent absolute addresses within the disassembled instruction. When creating a `DisassemblerTextPart' with this style, you should consider if a `DisassemblerAddressPart' would be more appropriate. See *Note Disassembler Styling Parts:: for a description of what each part offers. GDB styles text with this style using the `disassembler address' style setting. `gdb.disassembler.STYLE_ADDRESS_OFFSET' This style is used for styling numerical values that represent offsets to addresses within the disassembled instruction. A value is considered an address offset when the instruction itself is going to access memory, and the value is being used to offset which address is accessed. For example, an architecture might have an instruction that loads from memory using an address within a register. If that instruction also allowed for an immediate offset to be encoded into the instruction, this would be an address offset. Similarly, a branch instruction might jump to an address in a register plus an address offset that is encoded into the instruction. GDB styles text with this style using the `disassembler immediate' style setting. `gdb.disassembler.STYLE_IMMEDIATE' Use `STYLE_IMMEDIATE' for any numerical values within a disassembled instruction when those values are not addresses, address offsets, or register numbers (The styles `STYLE_ADDRESS', `STYLE_ADDRESS_OFFSET', or `STYLE_REGISTER' can be used in those cases). GDB styles text with this style using the `disassembler immediate' style setting. `gdb.disassembler.STYLE_SYMBOL' This style is used for styling the textual name of a symbol that is included within a disassembled instruction. A symbol name is often included next to an absolute address within a disassembled instruction to make it easier for the user to understand what the address is referring too. For example: call 0x401136 Here `foo' is the name of a symbol, and should be given the `STYLE_SYMBOL' style. Adding symbols next to absolute addresses like this is handled automatically by the `DisassemblerAddressPart' class (*note Disassembler Styling Parts::). GDB styles text with this style using the `disassembler symbol' style setting. `gdb.disassembler.STYLE_COMMENT_START' This style is used to start a line comment in the disassembly output. Unlike other styles, which only apply to the single `DisassemblerTextPiece' to which they are applied, the comment style is sticky, and overrides the style of any further pieces within this instruction. This means that, after a `STYLE_COMMENT_START' piece has been seen, GDB will apply the comment style until the end of the line, ignoring the specific style within a piece. GDB styles text with this style using the `disassembler comment' style setting. The following functions are also contained in the `gdb.disassembler' module: -- Function: register_disassembler (disassembler, architecture) The DISASSEMBLER must be a sub-class of `gdb.disassembler.Disassembler' or `None'. The optional ARCHITECTURE is either a string, or the value `None'. If it is a string, then it should be the name of an architecture known to GDB, as returned either from `gdb.Architecture.name' (*note gdb.Architecture.name: gdbpy_architecture_name.), or from `gdb.architecture_names' (*note gdb.architecture_names: gdb_architecture_names.). The DISASSEMBLER will be installed for the architecture named by ARCHITECTURE, or if ARCHITECTURE is `None', then DISASSEMBLER will be installed as a global disassembler for use by all architectures. GDB only records a single disassembler for each architecture, and a single global disassembler. Calling `register_disassembler' for an architecture, or for the global disassembler, will replace any existing disassembler registered for that ARCHITECTURE value. The previous disassembler is returned. If DISASSEMBLER is `None' then any disassembler currently registered for ARCHITECTURE is deregistered and returned. When GDB is looking for a disassembler to use, GDB first looks for an architecture specific disassembler. If none has been registered then GDB looks for a global disassembler (one registered with ARCHITECTURE set to `None'). Only one disassembler is called to perform disassembly, so, if there is both an architecture specific disassembler, and a global disassembler registered, it is the architecture specific disassembler that will be used. GDB tracks the architecture specific, and global disassemblers separately, so it doesn't matter in which order disassemblers are created or registered; an architecture specific disassembler, if present, will always be used in preference to a global disassembler. You can use the `maint info python-disassemblers' command (*note maint info python-disassemblers::) to see which disassemblers have been registered. -- Function: builtin_disassemble (info) This function calls back into GDB's builtin disassembler to disassemble the instruction identified by INFO, an instance, or sub-class, of `DisassembleInfo'. When the builtin disassembler needs to read memory the `read_memory' method on INFO will be called. By sub-classing `DisassembleInfo' and overriding the `read_memory' method, it is possible to intercept calls to `read_memory' from the builtin disassembler, and to modify the values returned. It is important to understand that, even when `DisassembleInfo.read_memory' raises a `gdb.MemoryError', it is the internal disassembler itself that reports the memory error to GDB. The reason for this is that the disassembler might probe memory to see if a byte is readable or not; if the byte can't be read then the disassembler may choose not to report an error, but instead to disassemble the bytes that it does have available. If the builtin disassembler is successful then an instance of `DisassemblerResult' is returned from `builtin_disassemble', alternatively, if something goes wrong, an exception will be raised. A `MemoryError' will be raised if `builtin_disassemble' is unable to read some memory that is required in order to perform disassembly correctly. Any exception that is not a `MemoryError', that is raised in a call to `read_memory', will pass through `builtin_disassemble', and be visible to the caller. Finally, there are a few cases where GDB's builtin disassembler can fail for reasons that are not covered by `MemoryError'. In these cases, a `GdbError' will be raised. The contents of the exception will be a string describing the problem the disassembler encountered. Here is an example that registers a global disassembler. The new disassembler invokes the builtin disassembler, and then adds a comment, `## Comment', to each line of disassembly output: class ExampleDisassembler(gdb.disassembler.Disassembler): def __init__(self): super().__init__("ExampleDisassembler") def __call__(self, info): result = gdb.disassembler.builtin_disassemble(info) length = result.length text = result.string + "\t## Comment" return gdb.disassembler.DisassemblerResult(length, text) gdb.disassembler.register_disassembler(ExampleDisassembler()) The following example creates a sub-class of `DisassembleInfo' in order to intercept the `read_memory' calls, within `read_memory' any bytes read from memory have the two 4-bit nibbles swapped around. This isn't a very useful adjustment, but serves as an example. class MyInfo(gdb.disassembler.DisassembleInfo): def __init__(self, info): super().__init__(info) def read_memory(self, length, offset): buffer = super().read_memory(length, offset) result = bytearray() for b in buffer: v = int.from_bytes(b, 'little') v = (v << 4) & 0xf0 | (v >> 4) result.append(v) return memoryview(result) class NibbleSwapDisassembler(gdb.disassembler.Disassembler): def __init__(self): super().__init__("NibbleSwapDisassembler") def __call__(self, info): info = MyInfo(info) return gdb.disassembler.builtin_disassemble(info) gdb.disassembler.register_disassembler(NibbleSwapDisassembler())  File: gdb.info, Node: Missing Debug Info In Python, Prev: Disassembly In Python, Up: Python API 23.3.2.41 Missing Debug Info In Python ...................................... When GDB encounters a new objfile (*note Objfiles In Python::), e.g. the primary executable, or any shared libraries used by the inferior, GDB will attempt to load the corresponding debug information for that objfile. The debug information might be found within the objfile itself, or within a separate objfile which GDB will automatically locate and load. Sometimes though, GDB might not find any debug information for an objfile, in this case the debugging experience will be restricted. If GDB fails to locate any debug information for a particular objfile, there is an opportunity for a Python extension to step in. A Python extension can potentially locate the missing debug information using some platform- or project-specific steps, and inform GDB of its location. Or a Python extension might provide some platform- or project-specific advice to the user about how to obtain the missing debug information. A missing debug information Python extension consists of a handler object which has the `name' and `enabled' attributes, and implements the `__call__' method. When GDB encounters an objfile for which it is unable to find any debug information, it invokes the `__call__' method. Full details of how handlers are written can be found below. The `gdb.missing_debug' Module ------------------------------ GDB comes with a `gdb.missing_debug' module which contains the following class and global function: -- class: gdb.missing_debug.MissingDebugHandler `MissingDebugHandler' is a base class from which user-created handlers can derive, though it is not required that handlers derive from this class, so long as any user created handler has the `name' and `enabled' attributes, and implements the `__call__' method. -- Function: MissingDebugHandler.__init__ (name) The NAME is a string used to reference this missing debug handler within some GDB commands. Valid names consist of the characters `[-_a-zA-Z0-9]', creating a handler with an invalid name raises a `ValueError' exception. -- Function: MissingDebugHandler.__call__ (objfile) Sub-classes must override the `__call__' method. The OBJFILE argument will be a `gdb.Objfile', this is the objfile for which GDB was unable to find any debug information. The return value from the `__call__' method indicates what GDB should do next. The possible return values are: * `None' This indicates that this handler could not help with OBJFILE, GDB should call any other registered handlers. * `True' This indicates that this handler has installed the debug information into a location where GDB would normally expect to find it when looking for separate debug information files (*note Separate Debug Files::). GDB will repeat the normal lookup process, which should now find the separate debug file. If GDB still doesn't find the separate debug information file after this second attempt, then the Python missing debug information handlers are not invoked a second time, this prevents a badly behaved handler causing GDB to get stuck in a loop. GDB will continue without any debug information for OBJFILE. * `False' This indicates that this handler has done everything that it intends to do with OBJFILE, but no separate debug information can be found. GDB will not call any other registered handlers for OBJFILE. GDB will continue without debugging information for OBJFILE. * A string The returned string should contain a filename. GDB will not call any further registered handlers, and will instead load the debug information from the file identified by the returned filename. Invoking the `__call__' method from this base class will raise a `NotImplementedError' exception. -- Variable: MissingDebugHandler.name A read-only attribute which is a string, the name of this handler passed to the `__init__' method. -- Variable: MissingDebugHandler.enabled A modifiable attribute containing a boolean; when `True', the handler is enabled, and will be used by GDB. When `False', the handler has been disabled, and will not be used. -- Function: gdb.missing_debug.register_handler (locus, handler, replace=`False') Register a new missing debug handler with GDB. HANDLER is an instance of a sub-class of `MissingDebugHandler', or at least an instance of an object that has the same attributes and methods as `MissingDebugHandler'. LOCUS specifies to which handler list to prepend HANDLER. It can be either a `gdb.Progspace' (*note Progspaces In Python::) or `None', in which case the handler is registered globally. The newly registered HANDLER will be called before any other handler from the same locus. Two handlers in the same locus cannot have the same name, an attempt to add a handler with an already existing name raises an exception unless REPLACE is `True', in which case the old handler is deleted and the new handler is prepended to the selected handler list. GDB first calls the handlers for the current program space, and then the globally registered handlers. As soon as a handler returns a value other than `None', no further handlers are called for this objfile.  File: gdb.info, Node: Python Auto-loading, Next: Python modules, Prev: Python API, Up: Python 23.3.3 Python Auto-loading -------------------------- When a new object file is read (for example, due to the `file' command, or because the inferior has loaded a shared library), GDB will look for Python support scripts in several ways: `OBJFILE-gdb.py' and `.debug_gdb_scripts' section. *Note Auto-loading extensions::. The auto-loading feature is useful for supplying application-specific debugging commands and scripts. Auto-loading can be enabled or disabled, and the list of auto-loaded scripts can be printed. `set auto-load python-scripts [on|off]' Enable or disable the auto-loading of Python scripts. `show auto-load python-scripts' Show whether auto-loading of Python scripts is enabled or disabled. `info auto-load python-scripts [REGEXP]' Print the list of all Python scripts that GDB auto-loaded. Also printed is the list of Python scripts that were mentioned in the `.debug_gdb_scripts' section and were either not found (*note dotdebug_gdb_scripts section::) or were not auto-loaded due to `auto-load safe-path' rejection (*note Auto-loading::). This is useful because their names are not printed when GDB tries to load them and fails. There may be many of them, and printing an error message for each one is problematic. If REGEXP is supplied only Python scripts with matching names are printed. Example: (gdb) info auto-load python-scripts Loaded Script Yes py-section-script.py full name: /tmp/py-section-script.py No my-foo-pretty-printers.py When reading an auto-loaded file or script, GDB sets the "current objfile". This is available via the `gdb.current_objfile' function (*note Objfiles In Python::). This can be useful for registering objfile-specific pretty-printers and frame-filters.  File: gdb.info, Node: Python modules, Prev: Python Auto-loading, Up: Python 23.3.4 Python modules --------------------- GDB comes with several modules to assist writing Python code. * Menu: * gdb.printing:: Building and registering pretty-printers. * gdb.types:: Utilities for working with types. * gdb.prompt:: Utilities for prompt value substitution.  File: gdb.info, Node: gdb.printing, Next: gdb.types, Up: Python modules 23.3.4.1 gdb.printing ..................... This module provides a collection of utilities for working with pretty-printers. `PrettyPrinter (NAME, SUBPRINTERS=None)' This class specifies the API that makes `info pretty-printer', `enable pretty-printer' and `disable pretty-printer' work. Pretty-printers should generally inherit from this class. `SubPrettyPrinter (NAME)' For printers that handle multiple types, this class specifies the corresponding API for the subprinters. `RegexpCollectionPrettyPrinter (NAME)' Utility class for handling multiple printers, all recognized via regular expressions. *Note Writing a Pretty-Printer::, for an example. `FlagEnumerationPrinter (NAME)' A pretty-printer which handles printing of `enum' values. Unlike GDB's built-in `enum' printing, this printer attempts to work properly when there is some overlap between the enumeration constants. The argument NAME is the name of the printer and also the name of the `enum' type to look up. `register_pretty_printer (OBJ, PRINTER, REPLACE=False)' Register PRINTER with the pretty-printer list of OBJ. If REPLACE is `True' then any existing copy of the printer is replaced. Otherwise a `RuntimeError' exception is raised if a printer with the same name already exists.  File: gdb.info, Node: gdb.types, Next: gdb.prompt, Prev: gdb.printing, Up: Python modules 23.3.4.2 gdb.types .................. This module provides a collection of utilities for working with `gdb.Type' objects. `get_basic_type (TYPE)' Return TYPE with const and volatile qualifiers stripped, and with typedefs and C++ references converted to the underlying type. C++ example: typedef const int const_int; const_int foo (3); const_int& foo_ref (foo); int main () { return 0; } Then in gdb: (gdb) start (gdb) python import gdb.types (gdb) python foo_ref = gdb.parse_and_eval("foo_ref") (gdb) python print gdb.types.get_basic_type(foo_ref.type) int `has_field (TYPE, FIELD)' Return `True' if TYPE, assumed to be a type with fields (e.g., a structure or union), has field FIELD. `make_enum_dict (ENUM_TYPE)' Return a Python `dictionary' type produced from ENUM_TYPE. `deep_items (TYPE)' Returns a Python iterator similar to the standard `gdb.Type.iteritems' method, except that the iterator returned by `deep_items' will recursively traverse anonymous struct or union fields. For example: struct A { int a; union { int b0; int b1; }; }; Then in GDB: (gdb) python import gdb.types (gdb) python struct_a = gdb.lookup_type("struct A") (gdb) python print struct_a.keys () {['a', '']} (gdb) python print [k for k,v in gdb.types.deep_items(struct_a)] {['a', 'b0', 'b1']} `get_type_recognizers ()' Return a list of the enabled type recognizers for the current context. This is called by GDB during the type-printing process (*note Type Printing API::). `apply_type_recognizers (recognizers, type_obj)' Apply the type recognizers, RECOGNIZERS, to the type object TYPE_OBJ. If any recognizer returns a string, return that string. Otherwise, return `None'. This is called by GDB during the type-printing process (*note Type Printing API::). `register_type_printer (locus, printer)' This is a convenience function to register a type printer PRINTER. The printer must implement the type printer protocol. The LOCUS argument is either a `gdb.Objfile', in which case the printer is registered with that objfile; a `gdb.Progspace', in which case the printer is registered with that progspace; or `None', in which case the printer is registered globally. `TypePrinter' This is a base class that implements the type printer protocol. Type printers are encouraged, but not required, to derive from this class. It defines a constructor: -- Method on TypePrinter: __init__ (self, name) Initialize the type printer with the given name. The new printer starts in the enabled state.  File: gdb.info, Node: gdb.prompt, Prev: gdb.types, Up: Python modules 23.3.4.3 gdb.prompt ................... This module provides a method for prompt value-substitution. `substitute_prompt (STRING)' Return STRING with escape sequences substituted by values. Some escape sequences take arguments. You can specify arguments inside "{}" immediately following the escape sequence. The escape sequences you can pass to this function are: `\\' Substitute a backslash. `\e' Substitute an ESC character. `\f' Substitute the selected frame; an argument names a frame parameter. `\n' Substitute a newline. `\p' Substitute a parameter's value; the argument names the parameter. `\r' Substitute a carriage return. `\t' Substitute the selected thread; an argument names a thread parameter. `\v' Substitute the version of GDB. `\w' Substitute the current working directory. `\[' Begin a sequence of non-printing characters. These sequences are typically used with the ESC character, and are not counted in the string length. Example: "\[\e[0;34m\](gdb)\[\e[0m\]" will return a blue-colored "(gdb)" prompt where the length is five. `\]' End a sequence of non-printing characters. For example: substitute_prompt ("frame: \f, args: \p{print frame-arguments}") will return the string: "frame: main, args: scalars"  File: gdb.info, Node: Guile, Next: Auto-loading extensions, Prev: Python, Up: Extending GDB 23.4 Extending GDB using Guile ============================== You can extend GDB using the Guile implementation of the Scheme programming language (http://www.gnu.org/software/guile/). This feature is available only if GDB was configured using `--with-guile'. * Menu: * Guile Introduction:: Introduction to Guile scripting in GDB * Guile Commands:: Accessing Guile from GDB * Guile API:: Accessing GDB from Guile * Guile Auto-loading:: Automatically loading Guile code * Guile Modules:: Guile modules provided by GDB  File: gdb.info, Node: Guile Introduction, Next: Guile Commands, Up: Guile 23.4.1 Guile Introduction ------------------------- Guile is an implementation of the Scheme programming language and is the GNU project's official extension language. Guile support in GDB follows the Python support in GDB reasonably closely, so concepts there should carry over. However, some things are done differently where it makes sense. GDB requires Guile version 3.0, 2.2, or 2.0. Guile scripts used by GDB should be installed in `DATA-DIRECTORY/guile', where DATA-DIRECTORY is the data directory as determined at GDB startup (*note Data Files::). This directory, known as the "guile directory", is automatically added to the Guile Search Path in order to allow the Guile interpreter to locate all scripts installed at this location.  File: gdb.info, Node: Guile Commands, Next: Guile API, Prev: Guile Introduction, Up: Guile 23.4.2 Guile Commands --------------------- GDB provides two commands for accessing the Guile interpreter: `guile-repl' `gr' The `guile-repl' command can be used to start an interactive Guile prompt or "repl". To return to GDB, type `,q' or the `EOF' character (e.g., `Ctrl-D' on an empty prompt). These commands do not take any arguments. `guile [SCHEME-EXPRESSION]' `gu [SCHEME-EXPRESSION]' The `guile' command can be used to evaluate a Scheme expression. If given an argument, GDB will pass the argument to the Guile interpreter for evaluation. (gdb) guile (display (+ 20 3)) (newline) 23 The result of the Scheme expression is displayed using normal Guile rules. (gdb) guile (+ 20 3) 23 If you do not provide an argument to `guile', it will act as a multi-line command, like `define'. In this case, the Guile script is made up of subsequent command lines, given after the `guile' command. This command list is terminated using a line containing `end'. For example: (gdb) guile >(display 23) >(newline) >end 23 It is also possible to execute a Guile script from the GDB interpreter: `source `script-name'' The script name must end with `.scm' and GDB must be configured to recognize the script language based on filename extension using the `script-extension' setting. *Note Extending GDB: Extending GDB. `guile (load "script-name")' This method uses the `load' Guile function. It takes a string argument that is the name of the script to load. See the Guile documentation for a description of this function. (*note Loading: (guile)Loading.).  File: gdb.info, Node: Guile API, Next: Guile Auto-loading, Prev: Guile Commands, Up: Guile 23.4.3 Guile API ---------------- You can get quick online help for GDB's Guile API by issuing the command `help guile', or by issuing the command `,help' from an interactive Guile session. Furthermore, most Guile procedures provided by GDB have doc strings which can be obtained with `,describe PROCEDURE-NAME' or `,d PROCEDURE-NAME' from the Guile interactive prompt. * Menu: * Basic Guile:: Basic Guile Functions * Guile Configuration:: Guile configuration variables * GDB Scheme Data Types:: Scheme representations of GDB objects * Guile Exception Handling:: How Guile exceptions are translated * Values From Inferior In Guile:: Guile representation of values * Arithmetic In Guile:: Arithmetic in Guile * Types In Guile:: Guile representation of types * Guile Pretty Printing API:: Pretty-printing values with Guile * Selecting Guile Pretty-Printers:: How GDB chooses a pretty-printer * Writing a Guile Pretty-Printer:: Writing a pretty-printer * Commands In Guile:: Implementing new commands in Guile * Parameters In Guile:: Adding new GDB parameters * Progspaces In Guile:: Program spaces * Objfiles In Guile:: Object files in Guile * Frames In Guile:: Accessing inferior stack frames from Guile * Blocks In Guile:: Accessing blocks from Guile * Symbols In Guile:: Guile representation of symbols * Symbol Tables In Guile:: Guile representation of symbol tables * Breakpoints In Guile:: Manipulating breakpoints using Guile * Lazy Strings In Guile:: Guile representation of lazy strings * Architectures In Guile:: Guile representation of architectures * Disassembly In Guile:: Disassembling instructions from Guile * I/O Ports in Guile:: GDB I/O ports * Memory Ports in Guile:: Accessing memory through ports and bytevectors * Iterators In Guile:: Basic iterator support  File: gdb.info, Node: Basic Guile, Next: Guile Configuration, Up: Guile API 23.4.3.1 Basic Guile .................... At startup, GDB overrides Guile's `current-output-port' and `current-error-port' to print using GDB's output-paging streams. A Guile program which outputs to one of these streams may have its output interrupted by the user (*note Screen Size::). In this situation, a Guile `signal' exception is thrown with value `SIGINT'. Guile's history mechanism uses the same naming as GDB's, namely the user of dollar-variables (e.g., $1, $2, etc.). The results of evaluations in Guile and in GDB are counted separately, `$1' in Guile is not the same value as `$1' in GDB. GDB is not thread-safe. If your Guile program uses multiple threads, you must be careful to only call GDB-specific functions in the GDB thread. Some care must be taken when writing Guile code to run in GDB. Two things are worth noting in particular: * GDB installs handlers for `SIGCHLD' and `SIGINT'. Guile code must not override these, or even change the options using `sigaction'. If your program changes the handling of these signals, GDB will most likely stop working correctly. Note that it is unfortunately common for GUI toolkits to install a `SIGCHLD' handler. * GDB takes care to mark its internal file descriptors as close-on-exec. However, this cannot be done in a thread-safe way on all platforms. Your Guile programs should be aware of this and should both create new file descriptors with the close-on-exec flag set and arrange to close unneeded file descriptors before starting a child process. GDB introduces a new Guile module, named `gdb'. All methods and classes added by GDB are placed in this module. GDB does not automatically `import' the `gdb' module, scripts must do this themselves. There are various options for how to import a module, so GDB leaves the choice of how the `gdb' module is imported to the user. To simplify interactive use, it is recommended to add one of the following to your ~/.gdbinit. guile (use-modules (gdb)) guile (use-modules ((gdb) #:renamer (symbol-prefix-proc 'gdb:))) Which one to choose depends on your preference. The second one adds `gdb:' as a prefix to all module functions and variables. The rest of this manual assumes the `gdb' module has been imported without any prefix. See the Guile documentation for `use-modules' for more information (*note Using Guile Modules: (guile)Using Guile Modules.). Example: (gdb) guile (value-type (make-value 1)) ERROR: Unbound variable: value-type Error while executing Scheme code. (gdb) guile (use-modules (gdb)) (gdb) guile (value-type (make-value 1)) int (gdb) The `(gdb)' module provides these basic Guile functions. -- Scheme Procedure: execute command [#:from-tty boolean] [#:to-string boolean] Evaluate COMMAND, a string, as a GDB CLI command. If a GDB exception happens while COMMAND runs, it is translated as described in *Note Guile Exception Handling: Guile Exception Handling. FROM-TTY specifies whether GDB ought to consider this command as having originated from the user invoking it interactively. It must be a boolean value. If omitted, it defaults to `#f'. By default, any output produced by COMMAND is sent to GDB's standard output (and to the log output if logging is turned on). If the TO-STRING parameter is `#t', then output will be collected by `execute' and returned as a string. The default is `#f', in which case the return value is unspecified. If TO-STRING is `#t', the GDB virtual terminal will be temporarily set to unlimited width and height, and its pagination will be disabled; *note Screen Size::. -- Scheme Procedure: history-ref number Return a value from GDB's value history (*note Value History::). The NUMBER argument indicates which history element to return. If NUMBER is negative, then GDB will take its absolute value and count backward from the last element (i.e., the most recent element) to find the value to return. If NUMBER is zero, then GDB will return the most recent element. If the element specified by NUMBER doesn't exist in the value history, a `gdb:error' exception will be raised. If no exception is raised, the return value is always an instance of `' (*note Values From Inferior In Guile::). _Note:_ GDB's value history is independent of Guile's. `$1' in GDB's value history contains the result of evaluating an expression from GDB's command line and `$1' from Guile's history contains the result of evaluating an expression from Guile's command line. -- Scheme Procedure: history-append! value Append VALUE, an instance of `', to GDB's value history. Return its index in the history. Putting into history values returned by Guile extensions will allow the user convenient access to those values via CLI history facilities. -- Scheme Procedure: parse-and-eval expression Parse EXPRESSION as an expression in the current language, evaluate it, and return the result as a `'. The EXPRESSION must be a string. This function can be useful when implementing a new command (*note Commands In Guile::), as it provides a way to parse the command's arguments as an expression. It is also is useful when computing values. For example, it is the only way to get the value of a convenience variable (*note Convenience Vars::) as a `'.  File: gdb.info, Node: Guile Configuration, Next: GDB Scheme Data Types, Prev: Basic Guile, Up: Guile API 23.4.3.2 Guile Configuration ............................ GDB provides these Scheme functions to access various configuration parameters. -- Scheme Procedure: data-directory Return a string containing GDB's data directory. This directory contains GDB's ancillary files. -- Scheme Procedure: guile-data-directory Return a string containing GDB's Guile data directory. This directory contains the Guile modules provided by GDB. -- Scheme Procedure: gdb-version Return a string containing the GDB version. -- Scheme Procedure: host-config Return a string containing the host configuration. This is the string passed to `--host' when GDB was configured. -- Scheme Procedure: target-config Return a string containing the target configuration. This is the string passed to `--target' when GDB was configured.  File: gdb.info, Node: GDB Scheme Data Types, Next: Guile Exception Handling, Prev: Guile Configuration, Up: Guile API 23.4.3.3 GDB Scheme Data Types .............................. The values exposed by GDB to Guile are known as "GDB objects". There are several kinds of GDB object, and each is disjoint from all other types known to Guile. -- Scheme Procedure: gdb-object-kind object Return the kind of the GDB object, e.g., `', as a symbol. GDB defines the following object types: `' *Note Architectures In Guile::. `' *Note Blocks In Guile::. `' *Note Blocks In Guile::. `' *Note Breakpoints In Guile::. `' *Note Commands In Guile::. `' *Note Guile Exception Handling::. `' *Note Frames In Guile::. `' *Note Iterators In Guile::. `' *Note Lazy Strings In Guile::. `' *Note Objfiles In Guile::. `' *Note Parameters In Guile::. `' *Note Guile Pretty Printing API::. `' *Note Guile Pretty Printing API::. `' *Note Progspaces In Guile::. `' *Note Symbols In Guile::. `' *Note Symbol Tables In Guile::. `' *Note Symbol Tables In Guile::. `' *Note Types In Guile::. `' *Note Types In Guile::. `' *Note Values From Inferior In Guile::. The following GDB objects are managed internally so that the Scheme function `eq?' may be applied to them. `' `' `' `' `' `' `' `' `'  File: gdb.info, Node: Guile Exception Handling, Next: Values From Inferior In Guile, Prev: GDB Scheme Data Types, Up: Guile API 23.4.3.4 Guile Exception Handling ................................. When executing the `guile' command, Guile exceptions uncaught within the Guile code are translated to calls to the GDB error-reporting mechanism. If the command that called `guile' does not handle the error, GDB will terminate it and report the error according to the setting of the `guile print-stack' parameter. The `guile print-stack' parameter has three settings: `none' Nothing is printed. `message' An error message is printed containing the Guile exception name, the associated value, and the Guile call stack backtrace at the point where the exception was raised. Example: (gdb) guile (display foo) ERROR: In procedure memoize-variable-access!: ERROR: Unbound variable: foo Error while executing Scheme code. `full' In addition to an error message a full backtrace is printed. (gdb) set guile print-stack full (gdb) guile (display foo) Guile Backtrace: In ice-9/boot-9.scm: 157: 10 [catch #t # ...] In unknown file: ?: 9 [apply-smob/1 #] In ice-9/boot-9.scm: 157: 8 [catch #t # ...] In unknown file: ?: 7 [apply-smob/1 #] ?: 6 [call-with-input-string "(display foo)" ...] In ice-9/boot-9.scm: 2320: 5 [save-module-excursion #] In ice-9/eval-string.scm: 44: 4 [read-and-eval # #:lang ...] 37: 3 [lp (display foo)] In ice-9/eval.scm: 387: 2 [eval # ()] 393: 1 [eval # ()] In unknown file: ?: 0 [memoize-variable-access! # ...] ERROR: In procedure memoize-variable-access!: ERROR: Unbound variable: foo Error while executing Scheme code. GDB errors that happen in GDB commands invoked by Guile code are converted to Guile exceptions. The type of the Guile exception depends on the error. Guile procedures provided by GDB can throw the standard Guile exceptions like `wrong-type-arg' and `out-of-range'. User interrupt (via `C-c' or by typing `q' at a pagination prompt) is translated to a Guile `signal' exception with value `SIGINT'. GDB Guile procedures can also throw these exceptions: `gdb:error' This exception is a catch-all for errors generated from within GDB. `gdb:invalid-object' This exception is thrown when accessing Guile objects that wrap underlying GDB objects have become invalid. For example, a `' object becomes invalid if the user deletes it from the command line. The object still exists in Guile, but the object it represents is gone. Further operations on this breakpoint will throw this exception. `gdb:memory-error' This exception is thrown when an operation tried to access invalid memory in the inferior. `gdb:pp-type-error' This exception is thrown when a Guile pretty-printer passes a bad object to GDB. The following exception-related procedures are provided by the `(gdb)' module. -- Scheme Procedure: make-exception key args Return a `' object given by its KEY and ARGS, which are the standard Guile parameters of an exception. See the Guile documentation for more information (*note Exceptions: (guile)Exceptions.). -- Scheme Procedure: exception? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: exception-key exception Return the ARGS field of a `' object. -- Scheme Procedure: exception-args exception Return the ARGS field of a `' object.  File: gdb.info, Node: Values From Inferior In Guile, Next: Arithmetic In Guile, Prev: Guile Exception Handling, Up: Guile API 23.4.3.5 Values From Inferior In Guile ...................................... GDB provides values it obtains from the inferior program in an object of type `'. GDB uses this object for its internal bookkeeping of the inferior's values, and for fetching values when necessary. GDB does not memoize `' objects. `make-value' always returns a fresh object. (gdb) guile (eq? (make-value 1) (make-value 1)) $1 = #f (gdb) guile (equal? (make-value 1) (make-value 1)) $1 = #t A `' that represents a function can be executed via inferior function call with `value-call'. Any arguments provided to the call must match the function's prototype, and must be provided in the order specified by that prototype. For example, `some-val' is a `' instance representing a function that takes two integers as arguments. To execute this function, call it like so: (define result (value-call some-val 10 20)) Any values returned from a function call are `' objects. Note: Unlike Python scripting in GDB, inferior values that are simple scalars cannot be used directly in Scheme expressions that are valid for the value's data type. For example, `(+ (parse-and-eval "int_variable") 2)' does not work. And inferior values that are structures or instances of some class cannot be accessed using any special syntax, instead `value-field' must be used. The following value-related procedures are provided by the `(gdb)' module. -- Scheme Procedure: value? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: make-value value [#:type type] Many Scheme values can be converted directly to a `' with this procedure. If TYPE is specified, the result is a value of this type, and if VALUE can't be represented with this type an exception is thrown. Otherwise the type of the result is determined from VALUE as described below. *Note Architectures In Guile::, for a list of the builtin types for an architecture. Here's how Scheme values are converted when TYPE argument to `make-value' is not specified: Scheme boolean A Scheme boolean is converted the boolean type for the current language. Scheme integer A Scheme integer is converted to the first of a C `int', `unsigned int', `long', `unsigned long', `long long' or `unsigned long long' type for the current architecture that can represent the value. If the Scheme integer cannot be represented as a target integer an `out-of-range' exception is thrown. Scheme real A Scheme real is converted to the C `double' type for the current architecture. Scheme string A Scheme string is converted to a string in the current target language using the current target encoding. Characters that cannot be represented in the current target encoding are replaced with the corresponding escape sequence. This is Guile's `SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE' conversion strategy (*note Strings: (guile)Strings.). Passing TYPE is not supported in this case, if it is provided a `wrong-type-arg' exception is thrown. `' If VALUE is a `' object (*note Lazy Strings In Guile::), then the `lazy-string->value' procedure is called, and its result is used. Passing TYPE is not supported in this case, if it is provided a `wrong-type-arg' exception is thrown. Scheme bytevector If VALUE is a Scheme bytevector and TYPE is provided, VALUE must be the same size, in bytes, of values of type TYPE, and the result is essentially created by using `memcpy'. If VALUE is a Scheme bytevector and TYPE is not provided, the result is an array of type `uint8' of the same length. -- Scheme Procedure: value-optimized-out? value Return `#t' if the compiler optimized out VALUE, thus it is not available for fetching from the inferior. Otherwise return `#f'. -- Scheme Procedure: value-address value If VALUE is addressable, returns a `' object representing the address. Otherwise, `#f' is returned. -- Scheme Procedure: value-type value Return the type of VALUE as a `' object (*note Types In Guile::). -- Scheme Procedure: value-dynamic-type value Return the dynamic type of VALUE. This uses C++ run-time type information (RTTI) to determine the dynamic type of the value. If the value is of class type, it will return the class in which the value is embedded, if any. If the value is of pointer or reference to a class type, it will compute the dynamic type of the referenced object, and return a pointer or reference to that type, respectively. In all other cases, it will return the value's static type. Note that this feature will only work when debugging a C++ program that includes RTTI for the object in question. Otherwise, it will just return the static type of the value as in `ptype foo'. *Note ptype: Symbols. -- Scheme Procedure: value-cast value type Return a new instance of `' that is the result of casting VALUE to the type described by TYPE, which must be a `' object. If the cast cannot be performed for some reason, this method throws an exception. -- Scheme Procedure: value-dynamic-cast value type Like `value-cast', but works as if the C++ `dynamic_cast' operator were used. Consult a C++ reference for details. -- Scheme Procedure: value-reinterpret-cast value type Like `value-cast', but works as if the C++ `reinterpret_cast' operator were used. Consult a C++ reference for details. -- Scheme Procedure: value-dereference value For pointer data types, this method returns a new `' object whose contents is the object pointed to by VALUE. For example, if `foo' is a C pointer to an `int', declared in your C program as int *foo; then you can use the corresponding `' to access what `foo' points to like this: (define bar (value-dereference foo)) The result `bar' will be a `' object holding the value pointed to by `foo'. A similar function `value-referenced-value' exists which also returns `' objects corresponding to the values pointed to by pointer values (and additionally, values referenced by reference values). However, the behavior of `value-dereference' differs from `value-referenced-value' by the fact that the behavior of `value-dereference' is identical to applying the C unary operator `*' on a given value. For example, consider a reference to a pointer `ptrref', declared in your C++ program as typedef int *intptr; ... int val = 10; intptr ptr = &val; intptr &ptrref = ptr; Though `ptrref' is a reference value, one can apply the method `value-dereference' to the `' object corresponding to it and obtain a `' which is identical to that corresponding to `val'. However, if you apply the method `value-referenced-value', the result would be a `' object identical to that corresponding to `ptr'. (define scm-ptrref (parse-and-eval "ptrref")) (define scm-val (value-dereference scm-ptrref)) (define scm-ptr (value-referenced-value scm-ptrref)) The `' object `scm-val' is identical to that corresponding to `val', and `scm-ptr' is identical to that corresponding to `ptr'. In general, `value-dereference' can be applied whenever the C unary operator `*' can be applied to the corresponding C value. For those cases where applying both `value-dereference' and `value-referenced-value' is allowed, the results obtained need not be identical (as we have seen in the above example). The results are however identical when applied on `' objects corresponding to pointers (`' objects with type code `TYPE_CODE_PTR') in a C/C++ program. -- Scheme Procedure: value-referenced-value value For pointer or reference data types, this method returns a new `' object corresponding to the value referenced by the pointer/reference value. For pointer data types, `value-dereference' and `value-referenced-value' produce identical results. The difference between these methods is that `value-dereference' cannot get the values referenced by reference values. For example, consider a reference to an `int', declared in your C++ program as int val = 10; int &ref = val; then applying `value-dereference' to the `' object corresponding to `ref' will result in an error, while applying `value-referenced-value' will result in a `' object identical to that corresponding to `val'. (define scm-ref (parse-and-eval "ref")) (define err-ref (value-dereference scm-ref)) ;; error (define scm-val (value-referenced-value scm-ref)) ;; ok The `' object `scm-val' is identical to that corresponding to `val'. -- Scheme Procedure: value-reference-value value Return a new `' object which is a reference to the value encapsulated by `' object VALUE. -- Scheme Procedure: value-rvalue-reference-value value Return a new `' object which is an rvalue reference to the value encapsulated by `' object VALUE. -- Scheme Procedure: value-const-value value Return a new `' object which is a `const' version of `' object VALUE. -- Scheme Procedure: value-field value field-name Return field FIELD-NAME from `' object VALUE. -- Scheme Procedure: value-subscript value index Return the value of array VALUE at index INDEX. The VALUE argument must be a subscriptable `' object. -- Scheme Procedure: value-call value arg-list Perform an inferior function call, taking VALUE as a pointer to the function to call. Each element of list ARG-LIST must be a object or an object that can be converted to a value. The result is the value returned by the function. -- Scheme Procedure: value->bool value Return the Scheme boolean representing `' VALUE. The value must be "integer like". Pointers are ok. -- Scheme Procedure: value->integer Return the Scheme integer representing `' VALUE. The value must be "integer like". Pointers are ok. -- Scheme Procedure: value->real Return the Scheme real number representing `' VALUE. The value must be a number. -- Scheme Procedure: value->bytevector Return a Scheme bytevector with the raw contents of `' VALUE. No transformation, endian or otherwise, is performed. -- Scheme Procedure: value->string value [#:encoding encoding] [#:errors errors] [#:length length] If VALUE> represents a string, then this method converts the contents to a Guile string. Otherwise, this method will throw an exception. Values are interpreted as strings according to the rules of the current language. If the optional length argument is given, the string will be converted to that length, and will include any embedded zeroes that the string may contain. Otherwise, for languages where the string is zero-terminated, the entire string will be converted. For example, in C-like languages, a value is a string if it is a pointer to or an array of characters or ints of type `wchar_t', `char16_t', or `char32_t'. If the optional ENCODING argument is given, it must be a string naming the encoding of the string in the `', such as `"ascii"', `"iso-8859-6"' or `"utf-8"'. It accepts the same encodings as the corresponding argument to Guile's `scm_from_stringn' function, and the Guile codec machinery will be used to convert the string. If ENCODING is not given, or if ENCODING is the empty string, then either the `target-charset' (*note Character Sets::) will be used, or a language-specific encoding will be used, if the current language is able to supply one. The optional ERRORS argument is one of `#f', `error' or `substitute'. `error' and `substitute' must be symbols. If ERRORS is not specified, or if its value is `#f', then the default conversion strategy is used, which is set with the Scheme function `set-port-conversion-strategy!'. If the value is `'error' then an exception is thrown if there is any conversion error. If the value is `'substitute' then any conversion error is replaced with question marks. *Note Strings: (guile)Strings. If the optional LENGTH argument is given, the string will be fetched and converted to the given length. The length must be a Scheme integer and not a `' integer. -- Scheme Procedure: value->lazy-string value [#:encoding encoding] [#:length length] If this `' represents a string, then this method converts VALUE to a `' integer. -- Scheme Procedure: value-lazy? value Return `#t' if VALUE has not yet been fetched from the inferior. Otherwise return `#f'. GDB does not fetch values until necessary, for efficiency. For example: (define myval (parse-and-eval "somevar")) The value of `somevar' is not fetched at this time. It will be fetched when the value is needed, or when the `fetch-lazy' procedure is invoked. -- Scheme Procedure: make-lazy-value type address Return a `' that will be lazily fetched from the target. The object of type `' whose value to fetch is specified by its TYPE and its target memory ADDRESS, which is a Scheme integer. -- Scheme Procedure: value-fetch-lazy! value If VALUE is a lazy value (`(value-lazy? value)' is `#t'), then the value is fetched from the inferior. Any errors that occur in the process will produce a Guile exception. If VALUE is not a lazy value, this method has no effect. The result of this function is unspecified. -- Scheme Procedure: value-print value Return the string representation (print form) of `' VALUE.  File: gdb.info, Node: Arithmetic In Guile, Next: Types In Guile, Prev: Values From Inferior In Guile, Up: Guile API 23.4.3.6 Arithmetic In Guile ............................ The `(gdb)' module provides several functions for performing arithmetic on `' objects. The arithmetic is performed as if it were done by the target, and therefore has target semantics which are not necessarily those of Scheme. For example operations work with a fixed precision, not the arbitrary precision of Scheme. Wherever a function takes an integer or pointer as an operand, GDB will convert appropriate Scheme values to perform the operation. -- Scheme Procedure: value-add a b -- Scheme Procedure: value-sub a b -- Scheme Procedure: value-mul a b -- Scheme Procedure: value-div a b -- Scheme Procedure: value-rem a b -- Scheme Procedure: value-mod a b -- Scheme Procedure: value-pow a b -- Scheme Procedure: value-not a -- Scheme Procedure: value-neg a -- Scheme Procedure: value-pos a -- Scheme Procedure: value-abs a -- Scheme Procedure: value-lsh a b -- Scheme Procedure: value-rsh a b -- Scheme Procedure: value-min a b -- Scheme Procedure: value-max a b -- Scheme Procedure: value-lognot a -- Scheme Procedure: value-logand a b -- Scheme Procedure: value-logior a b -- Scheme Procedure: value-logxor a b -- Scheme Procedure: value=? a b -- Scheme Procedure: value? a b -- Scheme Procedure: value>=? a b Scheme does not provide a `not-equal' function, and thus Guile support in GDB does not either.  File: gdb.info, Node: Types In Guile, Next: Guile Pretty Printing API, Prev: Arithmetic In Guile, Up: Guile API 23.4.3.7 Types In Guile ....................... GDB represents types from the inferior in objects of type `'. The following type-related procedures are provided by the `(gdb)' module. -- Scheme Procedure: type? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: lookup-type name [#:block block] This function looks up a type by its NAME, which must be a string. If BLOCK is given, it is an object of type `', and NAME is looked up in that scope. Otherwise, it is searched for globally. Ordinarily, this function will return an instance of `'. If the named type cannot be found, it will throw an exception. -- Scheme Procedure: type-code type Return the type code of TYPE. The type code will be one of the `TYPE_CODE_' constants defined below. -- Scheme Procedure: type-tag type Return the tag name of TYPE. The tag name is the name after `struct', `union', or `enum' in C and C++; not all languages have this concept. If this type has no tag name, then `#f' is returned. -- Scheme Procedure: type-name type Return the name of TYPE. If this type has no name, then `#f' is returned. -- Scheme Procedure: type-print-name type Return the print name of TYPE. This returns something even for anonymous types. For example, for an anonymous C struct `"struct {...}"' is returned. -- Scheme Procedure: type-sizeof type Return the size of this type, in target `char' units. Usually, a target's `char' type will be an 8-bit byte. However, on some unusual platforms, this type may have a different size. -- Scheme Procedure: type-strip-typedefs type Return a new `' that represents the real type of TYPE, after removing all layers of typedefs. -- Scheme Procedure: type-array type n1 [n2] Return a new `' object which represents an array of this type. If one argument is given, it is the inclusive upper bound of the array; in this case the lower bound is zero. If two arguments are given, the first argument is the lower bound of the array, and the second argument is the upper bound of the array. An array's length must not be negative, but the bounds can be. -- Scheme Procedure: type-vector type n1 [n2] Return a new `' object which represents a vector of this type. If one argument is given, it is the inclusive upper bound of the vector; in this case the lower bound is zero. If two arguments are given, the first argument is the lower bound of the vector, and the second argument is the upper bound of the vector. A vector's length must not be negative, but the bounds can be. The difference between an `array' and a `vector' is that arrays behave like in C: when used in expressions they decay to a pointer to the first element whereas vectors are treated as first class values. -- Scheme Procedure: type-pointer type Return a new `' object which represents a pointer to TYPE. -- Scheme Procedure: type-range type Return a list of two elements: the low bound and high bound of TYPE. If TYPE does not have a range, an exception is thrown. -- Scheme Procedure: type-reference type Return a new `' object which represents a reference to TYPE. -- Scheme Procedure: type-target type Return a new `' object which represents the target type of TYPE. For a pointer type, the target type is the type of the pointed-to object. For an array type (meaning C-like arrays), the target type is the type of the elements of the array. For a function or method type, the target type is the type of the return value. For a complex type, the target type is the type of the elements. For a typedef, the target type is the aliased type. If the type does not have a target, this method will throw an exception. -- Scheme Procedure: type-const type Return a new `' object which represents a `const'-qualified variant of TYPE. -- Scheme Procedure: type-volatile type Return a new `' object which represents a `volatile'-qualified variant of TYPE. -- Scheme Procedure: type-unqualified type Return a new `' object which represents an unqualified variant of TYPE. That is, the result is neither `const' nor `volatile'. -- Scheme Procedure: type-num-fields Return the number of fields of `' TYPE. -- Scheme Procedure: type-fields type Return the fields of TYPE as a list. For structure and union types, `fields' has the usual meaning. Range types have two fields, the minimum and maximum values. Enum types have one field per enum constant. Function and method types have one field per parameter. The base types of C++ classes are also represented as fields. If the type has no fields, or does not fit into one of these categories, an empty list will be returned. *Note Fields of a type in Guile::. -- Scheme Procedure: make-field-iterator type Return the fields of TYPE as a object. *Note Iterators In Guile::. -- Scheme Procedure: type-field type field-name Return field named FIELD-NAME in TYPE. The result is an object of type `'. *Note Fields of a type in Guile::. If the type does not have fields, or FIELD-NAME is not a field of TYPE, an exception is thrown. For example, if `some-type' is a `' instance holding a structure type, you can access its `foo' field with: (define bar (type-field some-type "foo")) `bar' will be a `' object. -- Scheme Procedure: type-has-field? type name Return `#t' if `' TYPE has field named NAME. Otherwise return `#f'. Each type has a code, which indicates what category this type falls into. The available type categories are represented by constants defined in the `(gdb)' module: `TYPE_CODE_PTR' The type is a pointer. `TYPE_CODE_ARRAY' The type is an array. `TYPE_CODE_STRUCT' The type is a structure. `TYPE_CODE_UNION' The type is a union. `TYPE_CODE_ENUM' The type is an enum. `TYPE_CODE_FLAGS' A bit flags type, used for things such as status registers. `TYPE_CODE_FUNC' The type is a function. `TYPE_CODE_INT' The type is an integer type. `TYPE_CODE_FLT' A floating point type. `TYPE_CODE_VOID' The special type `void'. `TYPE_CODE_SET' A Pascal set type. `TYPE_CODE_RANGE' A range type, that is, an integer type with bounds. `TYPE_CODE_STRING' A string type. Note that this is only used for certain languages with language-defined string types; C strings are not represented this way. `TYPE_CODE_BITSTRING' A string of bits. It is deprecated. `TYPE_CODE_ERROR' An unknown or erroneous type. `TYPE_CODE_METHOD' A method type, as found in C++. `TYPE_CODE_METHODPTR' A pointer-to-member-function. `TYPE_CODE_MEMBERPTR' A pointer-to-member. `TYPE_CODE_REF' A reference type. `TYPE_CODE_RVALUE_REF' A C++11 rvalue reference type. `TYPE_CODE_CHAR' A character type. `TYPE_CODE_BOOL' A boolean type. `TYPE_CODE_COMPLEX' A complex float type. `TYPE_CODE_TYPEDEF' A typedef to some other type. `TYPE_CODE_NAMESPACE' A C++ namespace. `TYPE_CODE_DECFLOAT' A decimal floating point type. `TYPE_CODE_INTERNAL_FUNCTION' A function internal to GDB. This is the type used to represent convenience functions (*note Convenience Funs::). `gdb.TYPE_CODE_XMETHOD' A method internal to GDB. This is the type used to represent xmethods (*note Writing an Xmethod::). `gdb.TYPE_CODE_FIXED_POINT' A fixed-point number. `gdb.TYPE_CODE_NAMESPACE' A Fortran namelist. Further support for types is provided in the `(gdb types)' Guile module (*note Guile Types Module::). Each field is represented as an object of type `'. The following field-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: field? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: field-name field Return the name of the field, or `#f' for anonymous fields. -- Scheme Procedure: field-type field Return the type of the field. This is usually an instance of `', but it can be `#f' in some situations. -- Scheme Procedure: field-enumval field Return the enum value represented by `' FIELD. -- Scheme Procedure: field-bitpos field Return the bit position of `' FIELD. This attribute is not available for `static' fields (as in C++). -- Scheme Procedure: field-bitsize field If the field is packed, or is a bitfield, return the size of `' FIELD in bits. Otherwise, zero is returned; in which case the field's size is given by its type. -- Scheme Procedure: field-artificial? field Return `#t' if the field is artificial, usually meaning that it was provided by the compiler and not the user. Otherwise return `#f'. -- Scheme Procedure: field-base-class? field Return `#t' if the field represents a base class of a C++ structure. Otherwise return `#f'.  File: gdb.info, Node: Guile Pretty Printing API, Next: Selecting Guile Pretty-Printers, Prev: Types In Guile, Up: Guile API 23.4.3.8 Guile Pretty Printing API .................................. An example output is provided (*note Pretty Printing::). A pretty-printer is represented by an object of type . Pretty-printer objects are created with `make-pretty-printer'. The following pretty-printer-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: make-pretty-printer name lookup-function Return a `' object named NAME. LOOKUP-FUNCTION is a function of one parameter: the value to be printed. If the value is handled by this pretty-printer, then LOOKUP-FUNCTION returns an object of type to perform the actual pretty-printing. Otherwise LOOKUP-FUNCTION returns `#f'. -- Scheme Procedure: pretty-printer? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: pretty-printer-enabled? pretty-printer Return `#t' if PRETTY-PRINTER is enabled. Otherwise return `#f'. -- Scheme Procedure: set-pretty-printer-enabled! pretty-printer flag Set the enabled flag of PRETTY-PRINTER to FLAG. The value returned is unspecified. -- Scheme Procedure: pretty-printers Return the list of global pretty-printers. -- Scheme Procedure: set-pretty-printers! pretty-printers Set the list of global pretty-printers to PRETTY-PRINTERS. The value returned is unspecified. -- Scheme Procedure: make-pretty-printer-worker display-hint to-string children Return an object of type `'. This function takes three parameters: `display-hint' DISPLAY-HINT provides a hint to GDB or GDB front end via MI to change the formatting of the value being printed. The value must be a string or `#f' (meaning there is no hint). Several values for DISPLAY-HINT are predefined by GDB: `array' Indicate that the object being printed is "array-like". The CLI uses this to respect parameters such as `set print elements' and `set print array'. `map' Indicate that the object being printed is "map-like", and that the children of this value can be assumed to alternate between keys and values. `string' Indicate that the object being printed is "string-like". If the printer's `to-string' function returns a Guile string of some kind, then GDB will call its internal language-specific string-printing function to format the string. For the CLI this means adding quotation marks, possibly escaping some characters, respecting `set print elements', and the like. `to-string' TO-STRING is either a function of one parameter, the `' object, or `#f'. When printing from the CLI, if the `to-string' method exists, then GDB will prepend its result to the values returned by `children'. Exactly how this formatting is done is dependent on the display hint, and may change as more hints are added. Also, depending on the print settings (*note Print Settings::), the CLI may print just the result of `to-string' in a stack trace, omitting the result of `children'. If this method returns a string, it is printed verbatim. Otherwise, if this method returns an instance of `', then GDB prints this value. This may result in a call to another pretty-printer. If instead the method returns a Guile value which is convertible to a `', then GDB performs the conversion and prints the resulting value. Again, this may result in a call to another pretty-printer. Guile scalars (integers, floats, and booleans) and strings are convertible to `'; other types are not. Finally, if this method returns `#f' then no further operations are performed in this method and nothing is printed. If the result is not one of these types, an exception is raised. TO-STRING may also be `#f' in which case it is left to CHILDREN to print the value. `children' CHILDREN is either a function of one parameter, the `' object, or `#f'. GDB will call this function on a pretty-printer to compute the children of the pretty-printer's value. This function must return a object. Each item returned by the iterator must be a tuple holding two elements. The first element is the "name" of the child; the second element is the child's value. The value can be any Guile object which is convertible to a GDB value. If CHILDREN is `#f', GDB will act as though the value has no children. Children may be hidden from display based on the value of `set print max-depth' (*note Print Settings::). GDB provides a function which can be used to look up the default pretty-printer for a `': -- Scheme Procedure: default-visualizer value This function takes a `' object as an argument. If a pretty-printer for this value exists, then it is returned. If no such printer exists, then this returns `#f'.  File: gdb.info, Node: Selecting Guile Pretty-Printers, Next: Writing a Guile Pretty-Printer, Prev: Guile Pretty Printing API, Up: Guile API 23.4.3.9 Selecting Guile Pretty-Printers ........................................ There are three sets of pretty-printers that GDB searches: * Per-objfile list of pretty-printers (*note Objfiles In Guile::). * Per-progspace list of pretty-printers (*note Progspaces In Guile::). * The global list of pretty-printers (*note Guile Pretty Printing API::). These printers are available when debugging any inferior. Pretty-printer lookup is done by passing the value to be printed to the lookup function of each enabled object in turn. Lookup stops when a lookup function returns a non-`#f' value or when the list is exhausted. Lookup functions must return either a `' object or `#f'. Otherwise an exception is thrown. GDB first checks the result of `objfile-pretty-printers' of each `' in the current program space and iteratively calls each enabled lookup function in the list for that `' until a non-`#f' object is returned. If no pretty-printer is found in the objfile lists, GDB then searches the result of `progspace-pretty-printers' of the current program space, calling each enabled function until a non-`#f' object is returned. After these lists have been exhausted, it tries the global pretty-printers list, obtained with `pretty-printers', again calling each enabled function until a non-`#f' object is returned. The order in which the objfiles are searched is not specified. For a given list, functions are always invoked from the head of the list, and iterated over sequentially until the end of the list, or a `' object is returned. For various reasons a pretty-printer may not work. For example, the underlying data structure may have changed and the pretty-printer is out of date. The consequences of a broken pretty-printer are severe enough that GDB provides support for enabling and disabling individual printers. For example, if `print frame-arguments' is on, a backtrace can become highly illegible if any argument is printed with a broken printer. Pretty-printers are enabled and disabled from Scheme by calling `set-pretty-printer-enabled!'. *Note Guile Pretty Printing API::.  File: gdb.info, Node: Writing a Guile Pretty-Printer, Next: Commands In Guile, Prev: Selecting Guile Pretty-Printers, Up: Guile API 23.4.3.10 Writing a Guile Pretty-Printer ........................................ A pretty-printer consists of two basic parts: a lookup function to determine if the type is supported, and the printer itself. Here is an example showing how a `std::string' printer might be written. *Note Guile Pretty Printing API::, for details. (define (make-my-string-printer value) "Print a my::string string" (make-pretty-printer-worker "string" (lambda (printer) (value-field value "_data")) #f)) And here is an example showing how a lookup function for the printer example above might be written. (define (str-lookup-function pretty-printer value) (let ((tag (type-tag (value-type value)))) (and tag (string-prefix? "std::string<" tag) (make-my-string-printer value)))) Then to register this printer in the global printer list: (append-pretty-printer! (make-pretty-printer "my-string" str-lookup-function)) The example lookup function extracts the value's type, and attempts to match it to a type that it can pretty-print. If it is a type the printer can pretty-print, it will return a object. If not, it returns `#f'. We recommend that you put your core pretty-printers into a Guile package. If your pretty-printers are for use with a library, we further recommend embedding a version number into the package name. This practice will enable GDB to load multiple versions of your pretty-printers at the same time, because they will have different names. You should write auto-loaded code (*note Guile Auto-loading::) such that it can be evaluated multiple times without changing its meaning. An ideal auto-load file will consist solely of `import's of your printer modules, followed by a call to a register pretty-printers with the current objfile. Taken as a whole, this approach will scale nicely to multiple inferiors, each potentially using a different library version. Embedding a version number in the Guile package name will ensure that GDB is able to load both sets of printers simultaneously. Then, because the search for pretty-printers is done by objfile, and because your auto-loaded code took care to register your library's printers with a specific objfile, GDB will find the correct printers for the specific version of the library used by each inferior. To continue the `my::string' example, this code might appear in `(my-project my-library v1)': (use-modules (gdb)) (define (register-printers objfile) (append-objfile-pretty-printer! (make-pretty-printer "my-string" str-lookup-function))) And then the corresponding contents of the auto-load file would be: (use-modules (gdb) (my-project my-library v1)) (register-printers (current-objfile)) The previous example illustrates a basic pretty-printer. There are a few things that can be improved on. The printer only handles one type, whereas a library typically has several types. One could install a lookup function for each desired type in the library, but one could also have a single lookup function recognize several types. The latter is the conventional way this is handled. If a pretty-printer can handle multiple data types, then its "subprinters" are the printers for the individual data types. The `(gdb printing)' module provides a formal way of solving this problem (*note Guile Printing Module::). Here is another example that handles multiple types. These are the types we are going to pretty-print: struct foo { int a, b; }; struct bar { struct foo x, y; }; Here are the printers: (define (make-foo-printer value) "Print a foo object" (make-pretty-printer-worker "foo" (lambda (printer) (format #f "a=<~a> b=<~a>" (value-field value "a") (value-field value "a"))) #f)) (define (make-bar-printer value) "Print a bar object" (make-pretty-printer-worker "foo" (lambda (printer) (format #f "x=<~a> y=<~a>" (value-field value "x") (value-field value "y"))) #f)) This example doesn't need a lookup function, that is handled by the `(gdb printing)' module. Instead a function is provided to build up the object that handles the lookup. (use-modules (gdb printing)) (define (build-pretty-printer) (let ((pp (make-pretty-printer-collection "my-library"))) (pp-collection-add-tag-printer "foo" make-foo-printer) (pp-collection-add-tag-printer "bar" make-bar-printer) pp)) And here is the autoload support: (use-modules (gdb) (my-library)) (append-objfile-pretty-printer! (current-objfile) (build-pretty-printer)) Finally, when this printer is loaded into GDB, here is the corresponding output of `info pretty-printer': (gdb) info pretty-printer my_library.so: my-library foo bar  File: gdb.info, Node: Commands In Guile, Next: Parameters In Guile, Prev: Writing a Guile Pretty-Printer, Up: Guile API 23.4.3.11 Commands In Guile ........................... You can implement new GDB CLI commands in Guile. A CLI command object is created with the `make-command' Guile function, and added to GDB with the `register-command!' Guile function. This two-step approach is taken to separate out the side-effect of adding the command to GDB from `make-command'. There is no support for multi-line commands, that is commands that consist of multiple lines and are terminated with `end'. -- Scheme Procedure: make-command name [#:invoke invoke] [#:command-class command-class] [#:completer-class completer] [#:prefix? prefix] [#:doc doc-string] The argument NAME is the name of the command. If NAME consists of multiple words, then the initial words are looked for as prefix commands. In this case, if one of the prefix commands does not exist, an exception is raised. The result is the `' object representing the command. The command is not usable until it has been registered with GDB with `register-command!'. The rest of the arguments are optional. The argument INVOKE is a procedure of three arguments: SELF, ARGS and FROM-TTY. The argument SELF is the `' object representing the command. The argument ARGS is a string representing the arguments passed to the command, after leading and trailing whitespace has been stripped. The argument FROM-TTY is a boolean flag and specifies whether the command should consider itself to have been originated from the user invoking it interactively. If this function throws an exception, it is turned into a GDB `error' call. Otherwise, the return value is ignored. The argument COMMAND-CLASS is one of the `COMMAND_' constants defined below. This argument tells GDB how to categorize the new command in the help system. The default is `COMMAND_NONE'. The argument COMPLETER is either `#f', one of the `COMPLETE_' constants defined below, or a procedure, also defined below. This argument tells GDB how to perform completion for this command. If not provided or if the value is `#f', then no completion is performed on the command. The argument PREFIX is a boolean flag indicating whether the new command is a prefix command; sub-commands of this command may be registered. The argument DOC-STRING is help text for the new command. If no documentation string is provided, the default value "This command is not documented." is used. -- Scheme Procedure: register-command! command Add COMMAND, a `' object, to GDB's list of commands. It is an error to register a command more than once. The result is unspecified. -- Scheme Procedure: command? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: dont-repeat By default, a GDB command is repeated when the user enters a blank line at the command prompt. A command can suppress this behavior by invoking the `dont-repeat' function. This is similar to the user command `dont-repeat', see *Note dont-repeat: Define. -- Scheme Procedure: string->argv string Convert a string to a list of strings split up according to GDB's argv parsing rules. It is recommended to use this for consistency. Arguments are separated by spaces and may be quoted. Example: scheme@@(guile-user)> (string->argv "1 2\\ \\\"3 '4 \"5' \"6 '7\"") $1 = ("1" "2 \"3" "4 \"5" "6 '7") -- Scheme Procedure: throw-user-error message . args Throw a `gdb:user-error' exception. The argument MESSAGE is the error message as a format string, like the FMT argument to the `format' Scheme function. *Note Formatted Output: (guile)Formatted Output. The argument ARGS is a list of the optional arguments of MESSAGE. This is used when the command detects a user error of some kind, say a bad command argument. (gdb) guile (use-modules (gdb)) (gdb) guile (register-command! (make-command "test-user-error" #:command-class COMMAND_OBSCURE #:invoke (lambda (self arg from-tty) (throw-user-error "Bad argument ~a" arg)))) end (gdb) test-user-error ugh ERROR: Bad argument ugh -- completer: self text word If the COMPLETER option to `make-command' is a procedure, it takes three arguments: SELF which is the `' object, and TEXT and WORD which are both strings. The argument TEXT holds the complete command line up to the cursor's location. The argument WORD holds the last word of the command line; this is computed using a word-breaking heuristic. All forms of completion are handled by this function, that is, the and key bindings (*note Completion::), and the `complete' command (*note complete: Help.). This procedure can return several kinds of values: * If the return value is a list, the contents of the list are used as the completions. It is up to COMPLETER to ensure that the contents actually do complete the word. An empty list is allowed, it means that there were no completions available. Only string elements of the list are used; other elements in the list are ignored. * If the return value is a `' object, it is iterated over to obtain the completions. It is up to `completer-procedure' to ensure that the results actually do complete the word. Only string elements of the result are used; other elements in the sequence are ignored. * All other results are treated as though there were no available completions. When a new command is registered, it will have been declared as a member of some general class of commands. This is used to classify top-level commands in the on-line help system; note that prefix commands are not listed under their own category but rather that of their top-level command. The available classifications are represented by constants defined in the `gdb' module: `COMMAND_NONE' The command does not belong to any particular class. A command in this category will not be displayed in any of the help categories. This is the default. `COMMAND_RUNNING' The command is related to running the inferior. For example, `start', `step', and `continue' are in this category. Type `help running' at the GDB prompt to see a list of commands in this category. `COMMAND_DATA' The command is related to data or variables. For example, `call', `find', and `print' are in this category. Type `help data' at the GDB prompt to see a list of commands in this category. `COMMAND_STACK' The command has to do with manipulation of the stack. For example, `backtrace', `frame', and `return' are in this category. Type `help stack' at the GDB prompt to see a list of commands in this category. `COMMAND_FILES' This class is used for file-related commands. For example, `file', `list' and `section' are in this category. Type `help files' at the GDB prompt to see a list of commands in this category. `COMMAND_SUPPORT' This should be used for "support facilities", generally meaning things that are useful to the user when interacting with GDB, but not related to the state of the inferior. For example, `help', `make', and `shell' are in this category. Type `help support' at the GDB prompt to see a list of commands in this category. `COMMAND_STATUS' The command is an `info'-related command, that is, related to the state of GDB itself. For example, `info', `macro', and `show' are in this category. Type `help status' at the GDB prompt to see a list of commands in this category. `COMMAND_BREAKPOINTS' The command has to do with breakpoints. For example, `break', `clear', and `delete' are in this category. Type `help breakpoints' at the GDB prompt to see a list of commands in this category. `COMMAND_TRACEPOINTS' The command has to do with tracepoints. For example, `trace', `actions', and `tfind' are in this category. Type `help tracepoints' at the GDB prompt to see a list of commands in this category. `COMMAND_USER' The command is a general purpose command for the user, and typically does not fit in one of the other categories. Type `help user-defined' at the GDB prompt to see a list of commands in this category, as well as the list of gdb macros (*note Sequences::). `COMMAND_OBSCURE' The command is only used in unusual circumstances, or is not of general interest to users. For example, `checkpoint', `fork', and `stop' are in this category. Type `help obscure' at the GDB prompt to see a list of commands in this category. `COMMAND_MAINTENANCE' The command is only useful to GDB maintainers. The `maintenance' and `flushregs' commands are in this category. Type `help internals' at the GDB prompt to see a list of commands in this category. A new command can use a predefined completion function, either by specifying it via an argument at initialization, or by returning it from the `completer' procedure. These predefined completion constants are all defined in the `gdb' module: `COMPLETE_NONE' This constant means that no completion should be done. `COMPLETE_FILENAME' This constant means that filename completion should be performed. `COMPLETE_LOCATION' This constant means that location completion should be done. *Note Location Specifications::. `COMPLETE_COMMAND' This constant means that completion should examine GDB command names. `COMPLETE_SYMBOL' This constant means that completion should be done using symbol names as the source. `COMPLETE_EXPRESSION' This constant means that completion should be done on expressions. Often this means completing on symbol names, but some language parsers also have support for completing on field names. The following code snippet shows how a trivial CLI command can be implemented in Guile: (gdb) guile (register-command! (make-command "hello-world" #:command-class COMMAND_USER #:doc "Greet the whole world." #:invoke (lambda (self args from-tty) (display "Hello, World!\n")))) end (gdb) hello-world Hello, World!  File: gdb.info, Node: Parameters In Guile, Next: Progspaces In Guile, Prev: Commands In Guile, Up: Guile API 23.4.3.12 Parameters In Guile ............................. You can implement new GDB "parameters" using Guile (1). There are many parameters that already exist and can be set in GDB. Two examples are: `set follow-fork' and `set charset'. Setting these parameters influences certain behavior in GDB. Similarly, you can define parameters that can be used to influence behavior in custom Guile scripts and commands. A new parameter is defined with the `make-parameter' Guile function, and added to GDB with the `register-parameter!' Guile function. This two-step approach is taken to separate out the side-effect of adding the parameter to GDB from `make-parameter'. Parameters are exposed to the user via the `set' and `show' commands. *Note Help::. -- Scheme Procedure: make-parameter name [#:command-class command-class] [#:parameter-type parameter-type] [#:enum-list enum-list] [#:set-func set-func] [#:show-func show-func] [#:doc doc] [#:set-doc set-doc] [#:show-doc show-doc] [#:initial-value initial-value] The argument NAME is the name of the new parameter. If NAME consists of multiple words, then the initial words are looked for as prefix parameters. An example of this can be illustrated with the `set print' set of parameters. If NAME is `print foo', then `print' will be searched as the prefix parameter. In this case the parameter can subsequently be accessed in GDB as `set print foo'. If NAME consists of multiple words, and no prefix parameter group can be found, an exception is raised. The result is the `' object representing the parameter. The parameter is not usable until it has been registered with GDB with `register-parameter!'. The rest of the arguments are optional. The argument COMMAND-CLASS should be one of the `COMMAND_' constants (*note Commands In Guile::). This argument tells GDB how to categorize the new parameter in the help system. The default is `COMMAND_NONE'. The argument PARAMETER-TYPE should be one of the `PARAM_' constants defined below. This argument tells GDB the type of the new parameter; this information is used for input validation and completion. The default is `PARAM_BOOLEAN'. If PARAMETER-TYPE is `PARAM_ENUM', then ENUM-LIST must be a list of strings. These strings represent the possible values for the parameter. If PARAMETER-TYPE is not `PARAM_ENUM', then the presence of ENUM-LIST will cause an exception to be thrown. The argument SET-FUNC is a function of one argument: SELF which is the `' object representing the parameter. GDB will call this function when a PARAMETER's value has been changed via the `set' API (for example, `set foo off'). The value of the parameter has already been set to the new value. This function must return a string to be displayed to the user. GDB will add a trailing newline if the string is non-empty. GDB generally doesn't print anything when a parameter is set, thus typically this function should return `""'. A non-empty string result should typically be used for displaying warnings and errors. The argument SHOW-FUNC is a function of two arguments: SELF which is the `' object representing the parameter, and SVALUE which is the string representation of the current value. GDB will call this function when a PARAMETER's `show' API has been invoked (for example, `show foo'). This function must return a string, and will be displayed to the user. GDB will add a trailing newline. The argument DOC is the help text for the new parameter. If there is no documentation string, a default value is used. The argument SET-DOC is the help text for this parameter's `set' command. The argument SHOW-DOC is the help text for this parameter's `show' command. The argument INITIAL-VALUE specifies the initial value of the parameter. If it is a function, it takes one parameter, the `' object and its result is used as the initial value of the parameter. The initial value must be valid for the parameter type, otherwise an exception is thrown. -- Scheme Procedure: register-parameter! parameter Add PARAMETER, a `' object, to GDB's list of parameters. It is an error to register a parameter more than once. The result is unspecified. -- Scheme Procedure: parameter? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: parameter-value parameter Return the value of PARAMETER which may either be a `' object or a string naming the parameter. -- Scheme Procedure: set-parameter-value! parameter new-value Assign PARAMETER the value of NEW-VALUE. The argument PARAMETER must be an object of type `'. GDB does validation when assignments are made. When a new parameter is defined, its type must be specified. The available types are represented by constants defined in the `gdb' module: `PARAM_BOOLEAN' The value is a plain boolean. The Guile boolean values, `#t' and `#f' are the only valid values. `PARAM_AUTO_BOOLEAN' The value has three possible states: true, false, and `auto'. In Guile, true and false are represented using boolean constants, and `auto' is represented using `#:auto'. `PARAM_UINTEGER' The value is an unsigned integer. The value of `#:unlimited' should be interpreted to mean "unlimited", and the value of `0' is reserved and should not be used. `PARAM_ZINTEGER' The value is an integer. `PARAM_ZUINTEGER' The value is an unsigned integer. `PARAM_ZUINTEGER_UNLIMITED' The value is an integer in the range `[0, INT_MAX]'. The value of `#:unlimited' means "unlimited", the value of `-1' is reserved and should not be used, and other negative numbers are not allowed. `PARAM_STRING' The value is a string. When the user modifies the string, any escape sequences, such as `\t', `\f', and octal escapes, are translated into corresponding characters and encoded into the current host charset. `PARAM_STRING_NOESCAPE' The value is a string. When the user modifies the string, escapes are passed through untranslated. `PARAM_OPTIONAL_FILENAME' The value is a either a filename (a string), or `#f'. `PARAM_FILENAME' The value is a filename. This is just like `PARAM_STRING_NOESCAPE', but uses file names for completion. `PARAM_ENUM' The value is a string, which must be one of a collection of string constants provided when the parameter is created. ---------- Footnotes ---------- (1) Note that GDB parameters must not be confused with Guile’s parameter objects (*note Parameters: (guile)Parameters.).  File: gdb.info, Node: Progspaces In Guile, Next: Objfiles In Guile, Prev: Parameters In Guile, Up: Guile API 23.4.3.13 Program Spaces In Guile ................................. A program space, or "progspace", represents a symbolic view of an address space. It consists of all of the objfiles of the program. *Note Objfiles In Guile::. *Note program spaces: Inferiors Connections and Programs, for more details about program spaces. Each progspace is represented by an instance of the `' smob. *Note GDB Scheme Data Types::. The following progspace-related functions are available in the `(gdb)' module: -- Scheme Procedure: progspace? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: progspace-valid? progspace Return `#t' if PROGSPACE is valid, `#f' if not. A `' object can become invalid if the program it refers to is not loaded in GDB any longer. -- Scheme Procedure: current-progspace This function returns the program space of the currently selected inferior. There is always a current progspace, this never returns `#f'. *Note Inferiors Connections and Programs::. -- Scheme Procedure: progspaces Return a list of all the progspaces currently known to GDB. -- Scheme Procedure: progspace-filename progspace Return the absolute file name of PROGSPACE as a string. This is the name of the file passed as the argument to the `file' or `symbol-file' commands. If the program space does not have an associated file name, then `#f' is returned. This occurs, for example, when GDB is started without a program to debug. A `gdb:invalid-object-error' exception is thrown if PROGSPACE is invalid. -- Scheme Procedure: progspace-objfiles progspace Return the list of objfiles of PROGSPACE. The order of objfiles in the result is arbitrary. Each element is an object of type `'. *Note Objfiles In Guile::. A `gdb:invalid-object-error' exception is thrown if PROGSPACE is invalid. -- Scheme Procedure: progspace-pretty-printers progspace Return the list of pretty-printers of PROGSPACE. Each element is an object of type `'. *Note Guile Pretty Printing API::, for more information. -- Scheme Procedure: set-progspace-pretty-printers! progspace printer-list Set the list of registered `' objects for PROGSPACE to PRINTER-LIST. *Note Guile Pretty Printing API::, for more information.  File: gdb.info, Node: Objfiles In Guile, Next: Frames In Guile, Prev: Progspaces In Guile, Up: Guile API 23.4.3.14 Objfiles In Guile ........................... GDB loads symbols for an inferior from various symbol-containing files (*note Files::). These include the primary executable file, any shared libraries used by the inferior, and any separate debug info files (*note Separate Debug Files::). GDB calls these symbol-containing files "objfiles". Each objfile is represented as an object of type `'. The following objfile-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: objfile? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: objfile-valid? objfile Return `#t' if OBJFILE is valid, `#f' if not. A `' object can become invalid if the object file it refers to is not loaded in GDB any longer. All other `' procedures will throw an exception if it is invalid at the time the procedure is called. -- Scheme Procedure: objfile-filename objfile Return the file name of OBJFILE as a string, with symbolic links resolved. -- Scheme Procedure: objfile-progspace objfile Return the `' that this object file lives in. *Note Progspaces In Guile::, for more on progspaces. -- Scheme Procedure: objfile-pretty-printers objfile Return the list of registered `' objects for OBJFILE. *Note Guile Pretty Printing API::, for more information. -- Scheme Procedure: set-objfile-pretty-printers! objfile printer-list Set the list of registered `' objects for OBJFILE to PRINTER-LIST. The PRINTER-LIST must be a list of `' objects. *Note Guile Pretty Printing API::, for more information. -- Scheme Procedure: current-objfile When auto-loading a Guile script (*note Guile Auto-loading::), GDB sets the "current objfile" to the corresponding objfile. This function returns the current objfile. If there is no current objfile, this function returns `#f'. -- Scheme Procedure: objfiles Return a list of all the objfiles in the current program space.  File: gdb.info, Node: Frames In Guile, Next: Blocks In Guile, Prev: Objfiles In Guile, Up: Guile API 23.4.3.15 Accessing inferior stack frames from Guile. ..................................................... When the debugged program stops, GDB is able to analyze its call stack (*note Stack frames: Frames.). The `' class represents a frame in the stack. A `' object is only valid while its corresponding frame exists in the inferior's stack. If you try to use an invalid frame object, GDB will throw a `gdb:invalid-object' exception (*note Guile Exception Handling::). Two `' objects can be compared for equality with the `equal?' function, like: (gdb) guile (equal? (newest-frame) (selected-frame)) #t The following frame-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: frame? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: frame-valid? frame Returns `#t' if FRAME is valid, `#f' if not. A frame object can become invalid if the frame it refers to doesn't exist anymore in the inferior. All `' procedures will throw an exception if the frame is invalid at the time the procedure is called. -- Scheme Procedure: frame-name frame Return the function name of FRAME, or `#f' if it can't be obtained. -- Scheme Procedure: frame-arch frame Return the `' object corresponding to FRAME's architecture. *Note Architectures In Guile::. -- Scheme Procedure: frame-type frame Return the type of FRAME. The value can be one of: `NORMAL_FRAME' An ordinary stack frame. `DUMMY_FRAME' A fake stack frame that was created by GDB when performing an inferior function call. `INLINE_FRAME' A frame representing an inlined function. The function was inlined into a `NORMAL_FRAME' that is older than this one. `TAILCALL_FRAME' A frame representing a tail call. *Note Tail Call Frames::. `SIGTRAMP_FRAME' A signal trampoline frame. This is the frame created by the OS when it calls into a signal handler. `ARCH_FRAME' A fake stack frame representing a cross-architecture call. `SENTINEL_FRAME' This is like `NORMAL_FRAME', but it is only used for the newest frame. -- Scheme Procedure: frame-unwind-stop-reason frame Return an integer representing the reason why it's not possible to find more frames toward the outermost frame. Use `unwind-stop-reason-string' to convert the value returned by this function to a string. The value can be one of: `FRAME_UNWIND_NO_REASON' No particular reason (older frames should be available). `FRAME_UNWIND_NULL_ID' The previous frame's analyzer returns an invalid result. `FRAME_UNWIND_OUTERMOST' This frame is the outermost. `FRAME_UNWIND_UNAVAILABLE' Cannot unwind further, because that would require knowing the values of registers or memory that have not been collected. `FRAME_UNWIND_INNER_ID' This frame ID looks like it ought to belong to a NEXT frame, but we got it for a PREV frame. Normally, this is a sign of unwinder failure. It could also indicate stack corruption. `FRAME_UNWIND_SAME_ID' This frame has the same ID as the previous one. That means that unwinding further would almost certainly give us another frame with exactly the same ID, so break the chain. Normally, this is a sign of unwinder failure. It could also indicate stack corruption. `FRAME_UNWIND_NO_SAVED_PC' The frame unwinder did not find any saved PC, but we needed one to unwind further. `FRAME_UNWIND_MEMORY_ERROR' The frame unwinder caused an error while trying to access memory. `FRAME_UNWIND_FIRST_ERROR' Any stop reason greater or equal to this value indicates some kind of error. This special value facilitates writing code that tests for errors in unwinding in a way that will work correctly even if the list of the other values is modified in future GDB versions. Using it, you could write: (define reason (frame-unwind-stop-readon (selected-frame))) (define reason-str (unwind-stop-reason-string reason)) (if (>= reason FRAME_UNWIND_FIRST_ERROR) (format #t "An error occurred: ~s\n" reason-str)) -- Scheme Procedure: frame-pc frame Return the frame's resume address. -- Scheme Procedure: frame-block frame Return the frame's code block as a `' object. *Note Blocks In Guile::. -- Scheme Procedure: frame-function frame Return the symbol for the function corresponding to this frame as a `' object, or `#f' if there isn't one. *Note Symbols In Guile::. -- Scheme Procedure: frame-older frame Return the frame that called FRAME. -- Scheme Procedure: frame-newer frame Return the frame called by FRAME. -- Scheme Procedure: frame-sal frame Return the frame's `' (symtab and line) object. *Note Symbol Tables In Guile::. -- Scheme Procedure: frame-read-register frame register Return the value of REGISTER in FRAME. REGISTER should be a string, like `pc'. -- Scheme Procedure: frame-read-var frame variable [#:block block] Return the value of VARIABLE in FRAME. If the optional argument BLOCK is provided, search for the variable from that block; otherwise start at the frame's current block (which is determined by the frame's current program counter). The VARIABLE must be given as a string or a `' object, and BLOCK must be a `' object. -- Scheme Procedure: frame-select frame Set FRAME to be the selected frame. *Note Examining the Stack: Stack. -- Scheme Procedure: selected-frame Return the selected frame object. *Note Selecting a Frame: Selection. -- Scheme Procedure: newest-frame Return the newest frame object for the selected thread. -- Scheme Procedure: unwind-stop-reason-string reason Return a string explaining the reason why GDB stopped unwinding frames, as expressed by the given REASON code (an integer, see the `frame-unwind-stop-reason' procedure above in this section).  File: gdb.info, Node: Blocks In Guile, Next: Symbols In Guile, Prev: Frames In Guile, Up: Guile API 23.4.3.16 Accessing blocks from Guile. ...................................... In GDB, symbols are stored in blocks. A block corresponds roughly to a scope in the source code. Blocks are organized hierarchically, and are represented individually in Guile as an object of type `'. Blocks rely on debugging information being available. A frame has a block. Please see *Note Frames In Guile::, for a more in-depth discussion of frames. The outermost block is known as the "global block". The global block typically holds public global variables and functions. The block nested just inside the global block is the "static block". The static block typically holds file-scoped variables and functions. GDB provides a method to get a block's superblock, but there is currently no way to examine the sub-blocks of a block, or to iterate over all the blocks in a symbol table (*note Symbol Tables In Guile::). Here is a short example that should help explain blocks: /* This is in the global block. */ int global; /* This is in the static block. */ static int file_scope; /* 'function' is in the global block, and 'argument' is in a block nested inside of 'function'. */ int function (int argument) { /* 'local' is in a block inside 'function'. It may or may not be in the same block as 'argument'. */ int local; { /* 'inner' is in a block whose superblock is the one holding 'local'. */ int inner; /* If this call is expanded by the compiler, you may see a nested block here whose function is 'inline_function' and whose superblock is the one holding 'inner'. */ inline_function (); } } The following block-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: block? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: block-valid? block Returns `#t' if `' BLOCK is valid, `#f' if not. A block object can become invalid if the block it refers to doesn't exist anymore in the inferior. All other `' methods will throw an exception if it is invalid at the time the procedure is called. The block's validity is also checked during iteration over symbols of the block. -- Scheme Procedure: block-start block Return the start address of `' BLOCK. -- Scheme Procedure: block-end block Return the end address of `' BLOCK. -- Scheme Procedure: block-function block Return the name of `' BLOCK represented as a `' object. If the block is not named, then `#f' is returned. For ordinary function blocks, the superblock is the static block. However, you should note that it is possible for a function block to have a superblock that is not the static block - for instance this happens for an inlined function. -- Scheme Procedure: block-superblock block Return the block containing `' BLOCK. If the parent block does not exist, then `#f' is returned. -- Scheme Procedure: block-global-block block Return the global block associated with `' BLOCK. -- Scheme Procedure: block-static-block block Return the static block associated with `' BLOCK. -- Scheme Procedure: block-global? block Return `#t' if `' BLOCK is a global block. Otherwise return `#f'. -- Scheme Procedure: block-static? block Return `#t' if `' BLOCK is a static block. Otherwise return `#f'. -- Scheme Procedure: block-symbols Return a list of all symbols (as objects) in `' BLOCK. -- Scheme Procedure: make-block-symbols-iterator block Return an object of type `' that will iterate over all symbols of the block. Guile programs should not assume that a specific block object will always contain a given symbol, since changes in GDB features and infrastructure may cause symbols move across blocks in a symbol table. *Note Iterators In Guile::. -- Scheme Procedure: block-symbols-progress? Return #t if the object is a object. This object would be obtained from the `progress' element of the `' object returned by `make-block-symbols-iterator'. -- Scheme Procedure: lookup-block pc Return the innermost `' containing the given PC value. If the block cannot be found for the PC value specified, the function will return `#f'.  File: gdb.info, Node: Symbols In Guile, Next: Symbol Tables In Guile, Prev: Blocks In Guile, Up: Guile API 23.4.3.17 Guile representation of Symbols. .......................................... GDB represents every variable, function and type as an entry in a symbol table. *Note Examining the Symbol Table: Symbols. Guile represents these symbols in GDB with the `' object. The following symbol-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: symbol? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: symbol-valid? symbol Return `#t' if the `' object is valid, `#f' if not. A `' object can become invalid if the symbol it refers to does not exist in GDB any longer. All other `' procedures will throw an exception if it is invalid at the time the procedure is called. -- Scheme Procedure: symbol-type symbol Return the type of SYMBOL or `#f' if no type is recorded. The result is an object of type `'. *Note Types In Guile::. -- Scheme Procedure: symbol-symtab symbol Return the symbol table in which SYMBOL appears. The result is an object of type `'. *Note Symbol Tables In Guile::. -- Scheme Procedure: symbol-line symbol Return the line number in the source code at which SYMBOL was defined. This is an integer. -- Scheme Procedure: symbol-name symbol Return the name of SYMBOL as a string. -- Scheme Procedure: symbol-linkage-name symbol Return the name of SYMBOL, as used by the linker (i.e., may be mangled). -- Scheme Procedure: symbol-print-name symbol Return the name of SYMBOL in a form suitable for output. This is either `name' or `linkage_name', depending on whether the user asked GDB to display demangled or mangled names. -- Scheme Procedure: symbol-addr-class symbol Return the address class of the symbol. This classifies how to find the value of a symbol. Each address class is a constant defined in the `(gdb)' module and described later in this chapter. -- Scheme Procedure: symbol-needs-frame? symbol Return `#t' if evaluating SYMBOL's value requires a frame (*note Frames In Guile::) and `#f' otherwise. Typically, local variables will require a frame, but other symbols will not. -- Scheme Procedure: symbol-argument? symbol Return `#t' if SYMBOL is an argument of a function. Otherwise return `#f'. -- Scheme Procedure: symbol-constant? symbol Return `#t' if SYMBOL is a constant. Otherwise return `#f'. -- Scheme Procedure: symbol-function? symbol Return `#t' if SYMBOL is a function or a method. Otherwise return `#f'. -- Scheme Procedure: symbol-variable? symbol Return `#t' if SYMBOL is a variable. Otherwise return `#f'. -- Scheme Procedure: symbol-value symbol [#:frame frame] Compute the value of SYMBOL, as a `'. For functions, this computes the address of the function, cast to the appropriate type. If the symbol requires a frame in order to compute its value, then FRAME must be given. If FRAME is not given, or if FRAME is invalid, then an exception is thrown. -- Scheme Procedure: lookup-symbol name [#:block block] [#:domain domain] This function searches for a symbol by name. The search scope can be restricted to the parameters defined in the optional domain and block arguments. NAME is the name of the symbol. It must be a string. The optional BLOCK argument restricts the search to symbols visible in that BLOCK. The BLOCK argument must be a `' object. If omitted, the block for the current frame is used. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the `(gdb)' module and described later in this chapter. The result is a list of two elements. The first element is a `' object or `#f' if the symbol is not found. If the symbol is found, the second element is `#t' if the symbol is a field of a method's object (e.g., `this' in C++), otherwise it is `#f'. If the symbol is not found, the second element is `#f'. -- Scheme Procedure: lookup-global-symbol name [#:domain domain] This function searches for a global symbol by name. The search scope can be restricted by the domain argument. NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the `(gdb)' module and described later in this chapter. The result is a `' object or `#f' if the symbol is not found. The available domain categories in `' are represented as constants in the `(gdb)' module: `SYMBOL_UNDEF_DOMAIN' This is used when a domain has not been discovered or none of the following domains apply. This usually indicates an error either in the symbol information or in GDB's handling of symbols. `SYMBOL_VAR_DOMAIN' This domain contains variables, function names, typedef names and enum type values. `SYMBOL_FUNCTION_DOMAIN' This domain contains functions. `SYMBOL_TYPE_DOMAIN' This domain contains types. In a C-like language, types using a tag (the name appearing after a `struct', `union', or `enum' keyword) will not appear here; in other languages, all types are in this domain. `SYMBOL_STRUCT_DOMAIN' This domain holds struct, union and enum tag names. This domain is only used for C-like languages. For example, in this code: struct type_one { int x; }; typedef struct type_one type_two; Here `type_one' will be in `SYMBOL_STRUCT_DOMAIN', but `type_two' will be in `SYMBOL_TYPE_DOMAIN'. `SYMBOL_LABEL_DOMAIN' This domain contains names of labels (for gotos). `SYMBOL_VARIABLES_DOMAIN' This domain holds a subset of the `SYMBOLS_VAR_DOMAIN'; it contains everything minus functions and types. `SYMBOL_FUNCTIONS_DOMAIN' This domain contains all functions. `SYMBOL_TYPES_DOMAIN' This domain contains all types. The available address class categories in `' are represented as constants in the `gdb' module: When searching for a symbol, the desired domain constant can be passed verbatim to the lookup function. For more complex searches, there is a corresponding set of constants, each named after one of the preceding constants, but with the `SEARCH' prefix replacing the `SYMBOL' prefix; for example, `SEARCH_LABEL_DOMAIN'. These may be or'd together to form a search constant. `SYMBOL_LOC_UNDEF' If this is returned by address class, it indicates an error either in the symbol information or in GDB's handling of symbols. `SYMBOL_LOC_CONST' Value is constant int. `SYMBOL_LOC_STATIC' Value is at a fixed address. `SYMBOL_LOC_REGISTER' Value is in a register. `SYMBOL_LOC_ARG' Value is an argument. This value is at the offset stored within the symbol inside the frame's argument list. `SYMBOL_LOC_REF_ARG' Value address is stored in the frame's argument list. Just like `LOC_ARG' except that the value's address is stored at the offset, not the value itself. `SYMBOL_LOC_REGPARM_ADDR' Value is a specified register. Just like `LOC_REGISTER' except the register holds the address of the argument instead of the argument itself. `SYMBOL_LOC_LOCAL' Value is a local variable. `SYMBOL_LOC_TYPEDEF' Value not used. Symbols in the domain `SYMBOL_STRUCT_DOMAIN' all have this class. `SYMBOL_LOC_BLOCK' Value is a block. `SYMBOL_LOC_CONST_BYTES' Value is a byte-sequence. `SYMBOL_LOC_UNRESOLVED' Value is at a fixed address, but the address of the variable has to be determined from the minimal symbol table whenever the variable is referenced. `SYMBOL_LOC_OPTIMIZED_OUT' The value does not actually exist in the program. `SYMBOL_LOC_COMPUTED' The value's address is a computed location.  File: gdb.info, Node: Symbol Tables In Guile, Next: Breakpoints In Guile, Prev: Symbols In Guile, Up: Guile API 23.4.3.18 Symbol table representation in Guile. ............................................... Access to symbol table data maintained by GDB on the inferior is exposed to Guile via two objects: `' (symtab-and-line) and `'. Symbol table and line data for a frame is returned from the `frame-find-sal' `' procedure. *Note Frames In Guile::. For more information on GDB's symbol table management, see *Note Examining the Symbol Table: Symbols. The following symtab-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: symtab? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: symtab-valid? symtab Return `#t' if the `' object is valid, `#f' if not. A `' object becomes invalid when the symbol table it refers to no longer exists in GDB. All other `' procedures will throw an exception if it is invalid at the time the procedure is called. -- Scheme Procedure: symtab-filename symtab Return the symbol table's source filename. -- Scheme Procedure: symtab-fullname symtab Return the symbol table's source absolute file name. -- Scheme Procedure: symtab-objfile symtab Return the symbol table's backing object file. *Note Objfiles In Guile::. -- Scheme Procedure: symtab-global-block symtab Return the global block of the underlying symbol table. *Note Blocks In Guile::. -- Scheme Procedure: symtab-static-block symtab Return the static block of the underlying symbol table. *Note Blocks In Guile::. The following symtab-and-line-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: sal? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: sal-valid? sal Return `#t' if SAL is valid, `#f' if not. A `' object becomes invalid when the Symbol table object it refers to no longer exists in GDB. All other `' procedures will throw an exception if it is invalid at the time the procedure is called. -- Scheme Procedure: sal-symtab sal Return the symbol table object (`') for SAL. -- Scheme Procedure: sal-line sal Return the line number for SAL. -- Scheme Procedure: sal-pc sal Return the start of the address range occupied by code for SAL. -- Scheme Procedure: sal-last sal Return the end of the address range occupied by code for SAL. -- Scheme Procedure: find-pc-line pc Return the `' object corresponding to the PC value. If an invalid value of PC is passed as an argument, then the `symtab' and `line' attributes of the returned `' object will be `#f' and 0 respectively.  File: gdb.info, Node: Breakpoints In Guile, Next: Lazy Strings In Guile, Prev: Symbol Tables In Guile, Up: Guile API 23.4.3.19 Manipulating breakpoints using Guile .............................................. Breakpoints in Guile are represented by objects of type `'. New breakpoints can be created with the `make-breakpoint' Guile function, and then added to GDB with the `register-breakpoint!' Guile function. This two-step approach is taken to separate out the side-effect of adding the breakpoint to GDB from `make-breakpoint'. Support is also provided to view and manipulate breakpoints created outside of Guile. The following breakpoint-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: make-breakpoint location [#:type type] [#:wp-class wp-class] [#:internal internal] [#:temporary temporary] Create a new breakpoint at LOCATION, a string naming the location of the breakpoint, or an expression that defines a watchpoint. The contents can be any location recognized by the `break' command, or in the case of a watchpoint, by the `watch' command. The breakpoint is initially marked as `invalid'. The breakpoint is not usable until it has been registered with GDB with `register-breakpoint!', at which point it becomes `valid'. The result is the `' object representing the breakpoint. The optional TYPE denotes the breakpoint to create. This argument can be either `BP_BREAKPOINT' or `BP_WATCHPOINT', and defaults to `BP_BREAKPOINT'. The optional WP-CLASS argument defines the class of watchpoint to create, if TYPE is `BP_WATCHPOINT'. If a watchpoint class is not provided, it is assumed to be a `WP_WRITE' class. The optional INTERNAL argument allows the breakpoint to become invisible to the user. The breakpoint will neither be reported when registered, nor will it be listed in the output from `info breakpoints' (but will be listed with the `maint info breakpoints' command). If an internal flag is not provided, the breakpoint is visible (non-internal). The optional TEMPORARY argument makes the breakpoint a temporary breakpoint. Temporary breakpoints are deleted after they have been hit, after which the Guile breakpoint is no longer usable (although it may be re-registered with `register-breakpoint!'). When a watchpoint is created, GDB will try to create a hardware assisted watchpoint. If successful, the type of the watchpoint is changed from `BP_WATCHPOINT' to `BP_HARDWARE_WATCHPOINT' for `WP_WRITE', `BP_READ_WATCHPOINT' for `WP_READ', and `BP_ACCESS_WATCHPOINT' for `WP_ACCESS'. If not successful, the type of the watchpoint is left as `WP_WATCHPOINT'. The available types are represented by constants defined in the `gdb' module: `BP_BREAKPOINT' Normal code breakpoint. `BP_WATCHPOINT' Watchpoint breakpoint. `BP_HARDWARE_WATCHPOINT' Hardware assisted watchpoint. This value cannot be specified when creating the breakpoint. `BP_READ_WATCHPOINT' Hardware assisted read watchpoint. This value cannot be specified when creating the breakpoint. `BP_ACCESS_WATCHPOINT' Hardware assisted access watchpoint. This value cannot be specified when creating the breakpoint. `BP_CATCHPOINT' Catchpoint. This value cannot be specified when creating the breakpoint. The available watchpoint types are represented by constants defined in the `(gdb)' module: `WP_READ' Read only watchpoint. `WP_WRITE' Write only watchpoint. `WP_ACCESS' Read/Write watchpoint. -- Scheme Procedure: register-breakpoint! breakpoint Add BREAKPOINT, a `' object, to GDB's list of breakpoints. The breakpoint must have been created with `make-breakpoint'. One cannot register breakpoints that have been created outside of Guile. Once a breakpoint is registered it becomes `valid'. It is an error to register an already registered breakpoint. The result is unspecified. -- Scheme Procedure: delete-breakpoint! breakpoint Remove BREAKPOINT from GDB's list of breakpoints. This also invalidates the Guile BREAKPOINT object. Any further attempt to access the object will throw an exception. If BREAKPOINT was created from Guile with `make-breakpoint' it may be re-registered with GDB, in which case the breakpoint becomes valid again. -- Scheme Procedure: breakpoints Return a list of all breakpoints. Each element of the list is a `' object. -- Scheme Procedure: breakpoint? object Return `#t' if OBJECT is a `' object, and `#f' otherwise. -- Scheme Procedure: breakpoint-valid? breakpoint Return `#t' if BREAKPOINT is valid, `#f' otherwise. Breakpoints created with `make-breakpoint' are marked as invalid until they are registered with GDB with `register-breakpoint!'. A `' object can become invalid if the user deletes the breakpoint. In this case, the object still exists, but the underlying breakpoint does not. In the cases of watchpoint scope, the watchpoint remains valid even if execution of the inferior leaves the scope of that watchpoint. -- Scheme Procedure: breakpoint-number breakpoint Return the breakpoint's number -- the identifier used by the user to manipulate the breakpoint. -- Scheme Procedure: breakpoint-temporary? breakpoint Return `#t' if the breakpoint was created as a temporary breakpoint. Temporary breakpoints are automatically deleted after they've been hit. Calling this procedure, and all other procedures other than `breakpoint-valid?' and `register-breakpoint!', will result in an error after the breakpoint has been hit (since it has been automatically deleted). -- Scheme Procedure: breakpoint-type breakpoint Return the breakpoint's type -- the identifier used to determine the actual breakpoint type or use-case. -- Scheme Procedure: breakpoint-visible? breakpoint Return `#t' if the breakpoint is visible to the user when hit, or when the `info breakpoints' command is run. Otherwise return `#f'. -- Scheme Procedure: breakpoint-location breakpoint Return the location of the breakpoint, as specified by the user. It is a string. If the breakpoint does not have a location (that is, it is a watchpoint) return `#f'. -- Scheme Procedure: breakpoint-expression breakpoint Return the breakpoint expression, as specified by the user. It is a string. If the breakpoint does not have an expression (the breakpoint is not a watchpoint) return `#f'. -- Scheme Procedure: breakpoint-enabled? breakpoint Return `#t' if the breakpoint is enabled, and `#f' otherwise. -- Scheme Procedure: set-breakpoint-enabled! breakpoint flag Set the enabled state of BREAKPOINT to FLAG. If flag is `#f' it is disabled, otherwise it is enabled. -- Scheme Procedure: breakpoint-silent? breakpoint Return `#t' if the breakpoint is silent, and `#f' otherwise. Note that a breakpoint can also be silent if it has commands and the first command is `silent'. This is not reported by the `silent' attribute. -- Scheme Procedure: set-breakpoint-silent! breakpoint flag Set the silent state of BREAKPOINT to FLAG. If flag is `#f' the breakpoint is made silent, otherwise it is made non-silent (or noisy). -- Scheme Procedure: breakpoint-ignore-count breakpoint Return the ignore count for BREAKPOINT. -- Scheme Procedure: set-breakpoint-ignore-count! breakpoint count Set the ignore count for BREAKPOINT to COUNT. -- Scheme Procedure: breakpoint-hit-count breakpoint Return hit count of BREAKPOINT. -- Scheme Procedure: set-breakpoint-hit-count! breakpoint count Set the hit count of BREAKPOINT to COUNT. At present, COUNT must be zero. -- Scheme Procedure: breakpoint-thread breakpoint Return the global-thread-id for thread-specific breakpoint BREAKPOINT. Return #f if BREAKPOINT is not thread-specific. -- Scheme Procedure: set-breakpoint-thread! breakpoint global-thread-id|#f Set the thread-id for BREAKPOINT to GLOBAL-THREAD-ID If set to `#f', the breakpoint is no longer thread-specific. -- Scheme Procedure: breakpoint-task breakpoint If the breakpoint is Ada task-specific, return the Ada task id. If the breakpoint is not task-specific (or the underlying language is not Ada), return `#f'. -- Scheme Procedure: set-breakpoint-task! breakpoint task Set the Ada task of BREAKPOINT to TASK. If set to `#f', the breakpoint is no longer task-specific. -- Scheme Procedure: breakpoint-condition breakpoint Return the condition of BREAKPOINT, as specified by the user. It is a string. If there is no condition, return `#f'. -- Scheme Procedure: set-breakpoint-condition! breakpoint condition Set the condition of BREAKPOINT to CONDITION, which must be a string. If set to `#f' then the breakpoint becomes unconditional. -- Scheme Procedure: breakpoint-stop breakpoint Return the stop predicate of BREAKPOINT. See `set-breakpoint-stop!' below in this section. -- Scheme Procedure: set-breakpoint-stop! breakpoint procedure|#f Set the stop predicate of BREAKPOINT. The predicate PROCEDURE takes one argument: the object. If this predicate is set to a procedure then it is invoked whenever the inferior reaches this breakpoint. If it returns `#t', or any non-`#f' value, then the inferior is stopped, otherwise the inferior will continue. If there are multiple breakpoints at the same location with a `stop' predicate, each one will be called regardless of the return status of the previous. This ensures that all `stop' predicates have a chance to execute at that location. In this scenario if one of the methods returns `#t' but the others return `#f', the inferior will still be stopped. You should not alter the execution state of the inferior (i.e., step, next, etc.), alter the current frame context (i.e., change the current active frame), or alter, add or delete any breakpoint. As a general rule, you should not alter any data within GDB or the inferior at this time. Example `stop' implementation: (define (my-stop? bkpt) (let ((int-val (parse-and-eval "foo"))) (value=? int-val 3))) (define bkpt (make-breakpoint "main.c:42")) (register-breakpoint! bkpt) (set-breakpoint-stop! bkpt my-stop?) -- Scheme Procedure: breakpoint-commands breakpoint Return the commands attached to BREAKPOINT as a string, or `#f' if there are none.  File: gdb.info, Node: Lazy Strings In Guile, Next: Architectures In Guile, Prev: Breakpoints In Guile, Up: Guile API 23.4.3.20 Guile representation of lazy strings. ............................................... A "lazy string" is a string whose contents is not retrieved or encoded until it is needed. A `' is represented in GDB as an `address' that points to a region of memory, an `encoding' that will be used to encode that region of memory, and a `length' to delimit the region of memory that represents the string. The difference between a `' and a string wrapped within a `' is that a `' will be treated differently by GDB when printing. A `' is retrieved and encoded during printing, while a `' wrapping a string is immediately retrieved and encoded on creation. The following lazy-string-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: lazy-string? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: lazy-string-address lazy-sring Return the address of LAZY-STRING. -- Scheme Procedure: lazy-string-length lazy-string Return the length of LAZY-STRING in characters. If the length is -1, then the string will be fetched and encoded up to the first null of appropriate width. -- Scheme Procedure: lazy-string-encoding lazy-string Return the encoding that will be applied to LAZY-STRING when the string is printed by GDB. If the encoding is not set, or contains an empty string, then GDB will select the most appropriate encoding when the string is printed. -- Scheme Procedure: lazy-string-type lazy-string Return the type that is represented by LAZY-STRING's type. For a lazy string this is a pointer or array type. To resolve this to the lazy string's character type, use `type-target-type'. *Note Types In Guile::. -- Scheme Procedure: lazy-string->value lazy-string Convert the `' to a `'. This value will point to the string in memory, but will lose all the delayed retrieval, encoding and handling that GDB applies to a `'.  File: gdb.info, Node: Architectures In Guile, Next: Disassembly In Guile, Prev: Lazy Strings In Guile, Up: Guile API 23.4.3.21 Guile representation of architectures ............................................... GDB uses architecture specific parameters and artifacts in a number of its various computations. An architecture is represented by an instance of the `' class. The following architecture-related procedures are provided by the `(gdb)' module: -- Scheme Procedure: arch? object Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: current-arch Return the current architecture as a `' object. -- Scheme Procedure: arch-name arch Return the name (string value) of `' ARCH. -- Scheme Procedure: arch-charset arch Return name of target character set of `' ARCH. -- Scheme Procedure: arch-wide-charset Return name of target wide character set of `' ARCH. Each architecture provides a set of predefined types, obtained by the following functions. -- Scheme Procedure: arch-void-type arch Return the `' object for a `void' type of architecture ARCH. -- Scheme Procedure: arch-char-type arch Return the `' object for a `char' type of architecture ARCH. -- Scheme Procedure: arch-short-type arch Return the `' object for a `short' type of architecture ARCH. -- Scheme Procedure: arch-int-type arch Return the `' object for an `int' type of architecture ARCH. -- Scheme Procedure: arch-long-type arch Return the `' object for a `long' type of architecture ARCH. -- Scheme Procedure: arch-schar-type arch Return the `' object for a `signed char' type of architecture ARCH. -- Scheme Procedure: arch-uchar-type arch Return the `' object for an `unsigned char' type of architecture ARCH. -- Scheme Procedure: arch-ushort-type arch Return the `' object for an `unsigned short' type of architecture ARCH. -- Scheme Procedure: arch-uint-type arch Return the `' object for an `unsigned int' type of architecture ARCH. -- Scheme Procedure: arch-ulong-type arch Return the `' object for an `unsigned long' type of architecture ARCH. -- Scheme Procedure: arch-float-type arch Return the `' object for a `float' type of architecture ARCH. -- Scheme Procedure: arch-double-type arch Return the `' object for a `double' type of architecture ARCH. -- Scheme Procedure: arch-longdouble-type arch Return the `' object for a `long double' type of architecture ARCH. -- Scheme Procedure: arch-bool-type arch Return the `' object for a `bool' type of architecture ARCH. -- Scheme Procedure: arch-longlong-type arch Return the `' object for a `long long' type of architecture ARCH. -- Scheme Procedure: arch-ulonglong-type arch Return the `' object for an `unsigned long long' type of architecture ARCH. -- Scheme Procedure: arch-int8-type arch Return the `' object for an `int8' type of architecture ARCH. -- Scheme Procedure: arch-uint8-type arch Return the `' object for a `uint8' type of architecture ARCH. -- Scheme Procedure: arch-int16-type arch Return the `' object for an `int16' type of architecture ARCH. -- Scheme Procedure: arch-uint16-type arch Return the `' object for a `uint16' type of architecture ARCH. -- Scheme Procedure: arch-int32-type arch Return the `' object for an `int32' type of architecture ARCH. -- Scheme Procedure: arch-uint32-type arch Return the `' object for a `uint32' type of architecture ARCH. -- Scheme Procedure: arch-int64-type arch Return the `' object for an `int64' type of architecture ARCH. -- Scheme Procedure: arch-uint64-type arch Return the `' object for a `uint64' type of architecture ARCH. Example: (gdb) guile (type-name (arch-uchar-type (current-arch))) "unsigned char"  File: gdb.info, Node: Disassembly In Guile, Next: I/O Ports in Guile, Prev: Architectures In Guile, Up: Guile API 23.4.3.22 Disassembly In Guile .............................. The disassembler can be invoked from Scheme code. Furthermore, the disassembler can take a Guile port as input, allowing one to disassemble from any source, and not just target memory. -- Scheme Procedure: arch-disassemble arch start-pc [#:port port] [#:offset offset] [#:size size] [#:count count] Return a list of disassembled instructions starting from the memory address START-PC. The optional argument PORT specifies the input port to read bytes from. If PORT is `#f' then bytes are read from target memory. The optional argument OFFSET specifies the address offset of the first byte in PORT. This is useful, for example, when PORT specifies a `bytevector' and you want the bytevector to be disassembled as if it came from that address. The START-PC passed to the reader for PORT is offset by the same amount. Example: (gdb) guile (use-modules (rnrs io ports)) (gdb) guile (define pc (value->integer (parse-and-eval "$pc"))) (gdb) guile (define mem (open-memory #:start pc)) (gdb) guile (define bv (get-bytevector-n mem 10)) (gdb) guile (define bv-port (open-bytevector-input-port bv)) (gdb) guile (define arch (current-arch)) (gdb) guile (arch-disassemble arch pc #:port bv-port #:offset pc) (((address . 4195516) (asm . "mov $0x4005c8,%edi") (length . 5))) The optional arguments SIZE and COUNT determine the number of instructions in the returned list. If either SIZE or COUNT is specified as zero, then no instructions are disassembled and an empty list is returned. If both the optional arguments SIZE and COUNT are specified, then a list of at most COUNT disassembled instructions whose start address falls in the closed memory address interval from START-PC to (START-PC + SIZE - 1) are returned. If SIZE is not specified, but COUNT is specified, then COUNT number of instructions starting from the address START-PC are returned. If COUNT is not specified but SIZE is specified, then all instructions whose start address falls in the closed memory address interval from START-PC to (START-PC + SIZE - 1) are returned. If neither SIZE nor COUNT are specified, then a single instruction at START-PC is returned. Each element of the returned list is an alist (associative list) with the following keys: `address' The value corresponding to this key is a Guile integer of the memory address of the instruction. `asm' The value corresponding to this key is a string value which represents the instruction with assembly language mnemonics. The assembly language flavor used is the same as that specified by the current CLI variable `disassembly-flavor'. *Note Machine Code::. `length' The value corresponding to this key is the length of the instruction in bytes.  File: gdb.info, Node: I/O Ports in Guile, Next: Memory Ports in Guile, Prev: Disassembly In Guile, Up: Guile API 23.4.3.23 I/O Ports in Guile ............................ -- Scheme Procedure: input-port Return GDB's input port as a Guile port object. -- Scheme Procedure: output-port Return GDB's output port as a Guile port object. -- Scheme Procedure: error-port Return GDB's error port as a Guile port object. -- Scheme Procedure: stdio-port? object Return `#t' if OBJECT is a GDB stdio port. Otherwise return `#f'.  File: gdb.info, Node: Memory Ports in Guile, Next: Iterators In Guile, Prev: I/O Ports in Guile, Up: Guile API 23.4.3.24 Memory Ports in Guile ............................... GDB provides a `port' interface to target memory. This allows Guile code to read/write target memory using Guile's port and bytevector functionality. The main routine is `open-memory' which returns a port object. One can then read/write memory using that object. -- Scheme Procedure: open-memory [#:mode mode] [#:start address] [#:size size] Return a port object that can be used for reading and writing memory. The port will be open according to MODE, which is the standard mode argument to Guile port open routines, except that the `"a"' and `"l"' modes are not supported. *Note File Ports: (guile)File Ports. The `"b"' (binary) character may be present, but is ignored: memory ports are binary only. If `"0"' is appended then the port is marked as unbuffered. The default is `"r"', read-only and buffered. The chunk of memory that can be accessed can be bounded. If both START and SIZE are unspecified, all of memory can be accessed. If only START is specified, all of memory from that point on can be accessed. If only SIZE if specified, all memory in the range [0,SIZE) can be accessed. If both are specified, all memory in the rane [START,START+SIZE) can be accessed. -- Scheme Procedure: memory-port? Return `#t' if OBJECT is an object of type `'. Otherwise return `#f'. -- Scheme Procedure: memory-port-range memory-port Return the range of `' MEMORY-PORT as a list of two elements: `(start end)'. The range is START to END inclusive. -- Scheme Procedure: memory-port-read-buffer-size memory-port Return the size of the read buffer of `' MEMORY-PORT. This procedure is deprecated and will be removed in GDB 11. It returns 0 when using Guile 2.2 or later. -- Scheme Procedure: set-memory-port-read-buffer-size! memory-port size Set the size of the read buffer of `' MEMORY-PORT to SIZE. The result is unspecified. This procedure is deprecated and will be removed in GDB 11. When GDB is built with Guile 2.2 or later, you can call `setvbuf' instead (*note `setvbuf': (guile)Buffering.). -- Scheme Procedure: memory-port-write-buffer-size memory-port Return the size of the write buffer of `' MEMORY-PORT. This procedure is deprecated and will be removed in GDB 11. It returns 0 when GDB is built with Guile 2.2 or later. -- Scheme Procedure: set-memory-port-write-buffer-size! memory-port size Set the size of the write buffer of `' MEMORY-PORT to SIZE. The result is unspecified. This procedure is deprecated and will be removed in GDB 11. When GDB is built with Guile 2.2 or later, you can call `setvbuf' instead. A memory port is closed like any other port, with `close-port'. Combined with Guile's `bytevectors', memory ports provide a lot of utility. For example, to fill a buffer of 10 integers in memory, one can do something like the following. ;; In the program: int buffer[10]; (use-modules (rnrs bytevectors)) (use-modules (rnrs io ports)) (define addr (parse-and-eval "buffer")) (define n 10) (define byte-size (* n 4)) (define mem-port (open-memory #:mode "r+" #:start (value->integer addr) #:size byte-size)) (define byte-vec (make-bytevector byte-size)) (do ((i 0 (+ i 1))) ((>= i n)) (bytevector-s32-native-set! byte-vec (* i 4) (* i 42))) (put-bytevector mem-port byte-vec) (close-port mem-port)  File: gdb.info, Node: Iterators In Guile, Prev: Memory Ports in Guile, Up: Guile API 23.4.3.25 Iterators In Guile ............................ A simple iterator facility is provided to allow, for example, iterating over the set of program symbols without having to first construct a list of all of them. A useful contribution would be to add support for SRFI 41 and SRFI 45. -- Scheme Procedure: make-iterator object progress next! A `' object is constructed with the `make-iterator' procedure. It takes three arguments: the object to be iterated over, an object to record the progress of the iteration, and a procedure to return the next element in the iteration, or an implementation chosen value to denote the end of iteration. By convention, end of iteration is marked with `(end-of-iteration)', and may be tested with the `end-of-iteration?' predicate. The result of `(end-of-iteration)' is chosen so that it is not otherwise used by the `(gdb)' module. If you are using `' in your own code it is your responsibility to maintain this invariant. A trivial example for illustration's sake: (use-modules (gdb iterator)) (define my-list (list 1 2 3)) (define iter (make-iterator my-list my-list (lambda (iter) (let ((l (iterator-progress iter))) (if (eq? l '()) (end-of-iteration) (begin (set-iterator-progress! iter (cdr l)) (car l))))))) Here is a slightly more realistic example, which computes a list of all the functions in `my-global-block'. (use-modules (gdb iterator)) (define this-sal (find-pc-line (frame-pc (selected-frame)))) (define this-symtab (sal-symtab this-sal)) (define this-global-block (symtab-global-block this-symtab)) (define syms-iter (make-block-symbols-iterator this-global-block)) (define functions (iterator-filter symbol-function? syms-iter)) -- Scheme Procedure: iterator? object Return `#t' if OBJECT is a `' object. Otherwise return `#f'. -- Scheme Procedure: iterator-object iterator Return the first argument that was passed to `make-iterator'. This is the object being iterated over. -- Scheme Procedure: iterator-progress iterator Return the object tracking iteration progress. -- Scheme Procedure: set-iterator-progress! iterator new-value Set the object tracking iteration progress. -- Scheme Procedure: iterator-next! iterator Invoke the procedure that was the third argument to `make-iterator', passing it one argument, the `' object. The result is either the next element in the iteration, or an end marker as implemented by the `next!' procedure. By convention the end marker is the result of `(end-of-iteration)'. -- Scheme Procedure: end-of-iteration Return the Scheme object that denotes end of iteration. -- Scheme Procedure: end-of-iteration? object Return `#t' if OBJECT is the end of iteration marker. Otherwise return `#f'. These functions are provided by the `(gdb iterator)' module to assist in using iterators. -- Scheme Procedure: make-list-iterator list Return a `' object that will iterate over LIST. -- Scheme Procedure: iterator->list iterator Return the elements pointed to by ITERATOR as a list. -- Scheme Procedure: iterator-map proc iterator Return the list of objects obtained by applying PROC to the object pointed to by ITERATOR and to each subsequent object. -- Scheme Procedure: iterator-for-each proc iterator Apply PROC to each element pointed to by ITERATOR. The result is unspecified. -- Scheme Procedure: iterator-filter pred iterator Return the list of elements pointed to by ITERATOR that satisfy PRED. -- Scheme Procedure: iterator-until pred iterator Run ITERATOR until the result of `(pred element)' is true and return that as the result. Otherwise return `#f'.  File: gdb.info, Node: Guile Auto-loading, Next: Guile Modules, Prev: Guile API, Up: Guile 23.4.4 Guile Auto-loading ------------------------- When a new object file is read (for example, due to the `file' command, or because the inferior has loaded a shared library), GDB will look for Guile support scripts in two ways: `OBJFILE-gdb.scm' and the `.debug_gdb_scripts' section. *Note Auto-loading extensions::. The auto-loading feature is useful for supplying application-specific debugging commands and scripts. Auto-loading can be enabled or disabled, and the list of auto-loaded scripts can be printed. `set auto-load guile-scripts [on|off]' Enable or disable the auto-loading of Guile scripts. `show auto-load guile-scripts' Show whether auto-loading of Guile scripts is enabled or disabled. `info auto-load guile-scripts [REGEXP]' Print the list of all Guile scripts that GDB auto-loaded. Also printed is the list of Guile scripts that were mentioned in the `.debug_gdb_scripts' section and were not found. This is useful because their names are not printed when GDB tries to load them and fails. There may be many of them, and printing an error message for each one is problematic. If REGEXP is supplied only Guile scripts with matching names are printed. Example: (gdb) info auto-load guile-scripts Loaded Script Yes scm-section-script.scm full name: /tmp/scm-section-script.scm No my-foo-pretty-printers.scm When reading an auto-loaded file, GDB sets the "current objfile". This is available via the `current-objfile' procedure (*note Objfiles In Guile::). This can be useful for registering objfile-specific pretty-printers.  File: gdb.info, Node: Guile Modules, Prev: Guile Auto-loading, Up: Guile 23.4.5 Guile Modules -------------------- GDB comes with several modules to assist writing Guile code. * Menu: * Guile Printing Module:: Building and registering pretty-printers * Guile Types Module:: Utilities for working with types  File: gdb.info, Node: Guile Printing Module, Next: Guile Types Module, Up: Guile Modules 23.4.5.1 Guile Printing Module .............................. This module provides a collection of utilities for working with pretty-printers. Usage: (use-modules (gdb printing)) -- Scheme Procedure: prepend-pretty-printer! object printer Add PRINTER to the front of the list of pretty-printers for OBJECT. The OBJECT must either be a `' object, or `#f' in which case PRINTER is added to the global list of printers. -- Scheme Procedure: append-pretty-printer! object printer Add PRINTER to the end of the list of pretty-printers for OBJECT. The OBJECT must either be a `' object, or `#f' in which case PRINTER is added to the global list of printers.  File: gdb.info, Node: Guile Types Module, Prev: Guile Printing Module, Up: Guile Modules 23.4.5.2 Guile Types Module ........................... This module provides a collection of utilities for working with `' objects. Usage: (use-modules (gdb types)) -- Scheme Procedure: get-basic-type type Return TYPE with const and volatile qualifiers stripped, and with typedefs and C++ references converted to the underlying type. C++ example: typedef const int const_int; const_int foo (3); const_int& foo_ref (foo); int main () { return 0; } Then in gdb: (gdb) start (gdb) guile (use-modules (gdb) (gdb types)) (gdb) guile (define foo-ref (parse-and-eval "foo_ref")) (gdb) guile (get-basic-type (value-type foo-ref)) int -- Scheme Procedure: type-has-field-deep? type field Return `#t' if TYPE, assumed to be a type with fields (e.g., a structure or union), has field FIELD. Otherwise return `#f'. This searches baseclasses, whereas `type-has-field?' does not. -- Scheme Procedure: make-enum-hashtable enum-type Return a Guile hash table produced from ENUM-TYPE. Elements in the hash table are referenced with `hashq-ref'.  File: gdb.info, Node: Auto-loading extensions, Next: Multiple Extension Languages, Prev: Guile, Up: Extending GDB 23.5 Auto-loading extensions ============================ GDB provides two mechanisms for automatically loading extensions when a new object file is read (for example, due to the `file' command, or because the inferior has loaded a shared library): `OBJFILE-gdb.EXT' (*note The `OBJFILE-gdb.EXT' file: objfile-gdbdotext file.) and the `.debug_gdb_scripts' section of modern file formats like ELF (*note The `.debug_gdb_scripts' section: dotdebug_gdb_scripts section.). For a discussion of the differences between these two approaches see *Note Which flavor to choose?::. The auto-loading feature is useful for supplying application-specific debugging commands and features. Auto-loading can be enabled or disabled, and the list of auto-loaded scripts can be printed. See the `auto-loading' section of each extension language for more information. For GDB command files see *Note Auto-loading sequences::. For Python files see *Note Python Auto-loading::. Note that loading of this script file also requires accordingly configured `auto-load safe-path' (*note Auto-loading safe path::). * Menu: * objfile-gdbdotext file:: The `OBJFILE-gdb.EXT' file * dotdebug_gdb_scripts section:: The `.debug_gdb_scripts' section * Which flavor to choose?:: Choosing between these approaches  File: gdb.info, Node: objfile-gdbdotext file, Next: dotdebug_gdb_scripts section, Up: Auto-loading extensions 23.5.1 The `OBJFILE-gdb.EXT' file --------------------------------- When a new object file is read, GDB looks for a file named `OBJFILE-gdb.EXT' (we call it SCRIPT-NAME below), where OBJFILE is the object file's name and where EXT is the file extension for the extension language: ``OBJFILE-gdb.gdb'' GDB's own command language ``OBJFILE-gdb.py'' Python ``OBJFILE-gdb.scm'' Guile SCRIPT-NAME is formed by ensuring that the file name of OBJFILE is absolute, following all symlinks, and resolving `.' and `..' components, and appending the `-gdb.EXT' suffix. If this file exists and is readable, GDB will evaluate it as a script in the specified extension language. If this file does not exist, then GDB will look for SCRIPT-NAME file in all of the directories as specified below. (On MS-Windows/MS-DOS, the drive letter of the executable's leading directories is converted to a one-letter subdirectory, i.e. `d:/usr/bin/' is converted to `/d/usr/bin/', because Windows filesystems disallow colons in file names.) Note that loading of these files requires an accordingly configured `auto-load safe-path' (*note Auto-loading safe path::). For object files using `.exe' suffix GDB tries to load first the scripts normally according to its `.exe' filename. But if no scripts are found GDB also tries script filenames matching the object file without its `.exe' suffix. This `.exe' stripping is case insensitive and it is attempted on any platform. This makes the script filenames compatible between Unix and MS-Windows hosts. `set auto-load scripts-directory [DIRECTORIES]' Control GDB auto-loaded scripts location. Multiple directory entries may be delimited by the host platform path separator in use (`:' on Unix, `;' on MS-Windows and MS-DOS). Each entry here needs to be covered also by the security setting `set auto-load safe-path' (*note set auto-load safe-path::). This variable defaults to `$debugdir:$datadir/auto-load'. The default `set auto-load safe-path' value can be also overridden by GDB configuration option `--with-auto-load-dir'. Any reference to `$debugdir' will get replaced by DEBUG-FILE-DIRECTORY value (*note Separate Debug Files::) and any reference to `$datadir' will get replaced by DATA-DIRECTORY which is determined at GDB startup (*note Data Files::). `$debugdir' and `$datadir' must be placed as a directory component -- either alone or delimited by `/' or `\' directory separators, depending on the host platform. The list of directories uses path separator (`:' on GNU and Unix systems, `;' on MS-Windows and MS-DOS) to separate directories, similarly to the `PATH' environment variable. `show auto-load scripts-directory' Show GDB auto-loaded scripts location. `add-auto-load-scripts-directory [DIRECTORIES...]' Add an entry (or list of entries) to the list of auto-loaded scripts locations. Multiple entries may be delimited by the host platform path separator in use. GDB does not track which files it has already auto-loaded this way. GDB will load the associated script every time the corresponding OBJFILE is opened. So your `-gdb.EXT' file should be careful to avoid errors if it is evaluated more than once.  File: gdb.info, Node: dotdebug_gdb_scripts section, Next: Which flavor to choose?, Prev: objfile-gdbdotext file, Up: Auto-loading extensions 23.5.2 The `.debug_gdb_scripts' section --------------------------------------- For systems using file formats like ELF and COFF, when GDB loads a new object file it will look for a special section named `.debug_gdb_scripts'. If this section exists, its contents is a list of null-terminated entries specifying scripts to load. Each entry begins with a non-null prefix byte that specifies the kind of entry, typically the extension language and whether the script is in a file or inlined in `.debug_gdb_scripts'. The following entries are supported: `SECTION_SCRIPT_ID_PYTHON_FILE = 1' `SECTION_SCRIPT_ID_SCHEME_FILE = 3' `SECTION_SCRIPT_ID_PYTHON_TEXT = 4' `SECTION_SCRIPT_ID_SCHEME_TEXT = 6' 23.5.2.1 Script File Entries ............................ If the entry specifies a file, GDB will look for the file first in the current directory and then along the source search path (*note Specifying Source Directories: Source Path.), except that `$cdir' is not searched, since the compilation directory is not relevant to scripts. File entries can be placed in section `.debug_gdb_scripts' with, for example, this GCC macro for Python scripts. /* Note: The "MS" section flags are to remove duplicates. */ #define DEFINE_GDB_PY_SCRIPT(script_name) \ asm("\ .pushsection \".debug_gdb_scripts\", \"MS\",@@progbits,1\n\ .byte 1 /* Python */\n\ .asciz \"" script_name "\"\n\ .popsection \n\ "); For Guile scripts, replace `.byte 1' with `.byte 3'. Then one can reference the macro in a header or source file like this: DEFINE_GDB_PY_SCRIPT ("my-app-scripts.py") The script name may include directories if desired. Note that loading of this script file also requires accordingly configured `auto-load safe-path' (*note Auto-loading safe path::). If the macro invocation is put in a header, any application or library using this header will get a reference to the specified script, and with the use of `"MS"' attributes on the section, the linker will remove duplicates. 23.5.2.2 Script Text Entries ............................ Script text entries allow to put the executable script in the entry itself instead of loading it from a file. The first line of the entry, everything after the prefix byte and up to the first newline (`0xa') character, is the script name, and must not contain any kind of space character, e.g., spaces or tabs. The rest of the entry, up to the trailing null byte, is the script to execute in the specified language. The name needs to be unique among all script names, as GDB executes each script only once based on its name. Here is an example from file `py-section-script.c' in the GDB testsuite. #include "symcat.h" #include "gdb/section-scripts.h" asm( ".pushsection \".debug_gdb_scripts\", \"MS\",@@progbits,1\n" ".byte " XSTRING (SECTION_SCRIPT_ID_PYTHON_TEXT) "\n" ".ascii \"gdb.inlined-script\\n\"\n" ".ascii \"class test_cmd (gdb.Command):\\n\"\n" ".ascii \" def __init__ (self):\\n\"\n" ".ascii \" super (test_cmd, self).__init__ (" "\\\"test-cmd\\\", gdb.COMMAND_OBSCURE)\\n\"\n" ".ascii \" def invoke (self, arg, from_tty):\\n\"\n" ".ascii \" print (\\\"test-cmd output, arg = %s\\\" % arg)\\n\"\n" ".ascii \"test_cmd ()\\n\"\n" ".byte 0\n" ".popsection\n" ); Loading of inlined scripts requires a properly configured `auto-load safe-path' (*note Auto-loading safe path::). The path to specify in `auto-load safe-path' is the path of the file containing the `.debug_gdb_scripts' section.  File: gdb.info, Node: Which flavor to choose?, Prev: dotdebug_gdb_scripts section, Up: Auto-loading extensions 23.5.3 Which flavor to choose? ------------------------------ Given the multiple ways of auto-loading extensions, it might not always be clear which one to choose. This section provides some guidance. Benefits of the `-gdb.EXT' way: * Can be used with file formats that don't support multiple sections. * Ease of finding scripts for public libraries. Scripts specified in the `.debug_gdb_scripts' section are searched for in the source search path. For publicly installed libraries, e.g., `libstdc++', there typically isn't a source directory in which to find the script. * Doesn't require source code additions. Benefits of the `.debug_gdb_scripts' way: * Works with static linking. Scripts for libraries done the `-gdb.EXT' way require an objfile to trigger their loading. When an application is statically linked the only objfile available is the executable, and it is cumbersome to attach all the scripts from all the input libraries to the executable's `-gdb.EXT' script. * Works with classes that are entirely inlined. Some classes can be entirely inlined, and thus there may not be an associated shared library to attach a `-gdb.EXT' script to. * Scripts needn't be copied out of the source tree. In some circumstances, apps can be built out of large collections of internal libraries, and the build infrastructure necessary to install the `-gdb.EXT' scripts in a place where GDB can find them is cumbersome. It may be easier to specify the scripts in the `.debug_gdb_scripts' section as relative paths, and add a path to the top of the source tree to the source search path.  File: gdb.info, Node: Multiple Extension Languages, Prev: Auto-loading extensions, Up: Extending GDB 23.6 Multiple Extension Languages ================================= The Guile and Python extension languages do not share any state, and generally do not interfere with each other. There are some things to be aware of, however. 23.6.1 Python comes first ------------------------- Python was GDB's first extension language, and to avoid breaking existing behaviour Python comes first. This is generally solved by the "first one wins" principle. GDB maintains a list of enabled extension languages, and when it makes a call to an extension language, (say to pretty-print a value), it tries each in turn until an extension language indicates it has performed the request (e.g., has returned the pretty-printed form of a value). This extends to errors while performing such requests: If an error happens while, for example, trying to pretty-print an object then the error is reported and any following extension languages are not tried.  File: gdb.info, Node: Interpreters, Next: TUI, Prev: Extending GDB, Up: Top 24 Command Interpreters *********************** GDB supports multiple command interpreters, and some command infrastructure to allow users or user interface writers to switch between interpreters or run commands in other interpreters. GDB currently supports two command interpreters, the console interpreter (sometimes called the command-line interpreter or CLI) and the machine interface interpreter (or GDB/MI). This manual describes both of these interfaces in great detail. By default, GDB will start with the console interpreter. However, the user may choose to start GDB with another interpreter by specifying the `-i' or `--interpreter' startup options. Defined interpreters include: `console' The traditional console or command-line interpreter. This is the most often used interpreter with GDB. With no interpreter specified at runtime, GDB will use this interpreter. `dap' When GDB has been built with Python support, it also supports the Debugger Adapter Protocol. This protocol can be used by a debugger GUI or an IDE to communicate with GDB. This protocol is documented at `https://microsoft.github.io/debug-adapter-protocol/'. *Note Debugger Adapter Protocol::, for information about GDB extensions to the protocol. `mi' The newest GDB/MI interface (currently `mi3'). Used primarily by programs wishing to use GDB as a backend for a debugger GUI or an IDE. For more information, see *Note The GDB/MI Interface: GDB/MI. `mi3' The GDB/MI interface introduced in GDB 9.1. `mi2' The GDB/MI interface introduced in GDB 6.0. You may execute commands in any interpreter from the current interpreter using the appropriate command. If you are running the console interpreter, simply use the `interpreter-exec' command: interpreter-exec mi "-data-list-register-names" GDB/MI has a similar command, although it is only available in versions of GDB which support GDB/MI version 2 (or greater). Note that `interpreter-exec' only changes the interpreter for the duration of the specified command. It does not change the interpreter permanently. Although you may only choose a single interpreter at startup, it is possible to run an independent interpreter on a specified input/output device (usually a tty). For example, consider a debugger GUI or IDE that wants to provide a GDB console view. It may do so by embedding a terminal emulator widget in its GUI, starting GDB in the traditional command-line mode with stdin/stdout/stderr redirected to that terminal, and then creating an MI interpreter running on a specified input/output device. The console interpreter created by GDB at startup handles commands the user types in the terminal widget, while the GUI controls and synchronizes state with GDB using the separate MI interpreter. To start a new secondary "user interface" running MI, use the `new-ui' command: new-ui INTERPRETER TTY The INTERPRETER parameter specifies the interpreter to run. This accepts the same values as the `interpreter-exec' command. For example, `console', `mi', `mi2', etc. The TTY parameter specifies the name of the bidirectional file the interpreter uses for input/output, usually the name of a pseudoterminal slave on Unix systems. For example: (gdb) new-ui mi /dev/pts/9 runs an MI interpreter on `/dev/pts/9'.  File: gdb.info, Node: TUI, Next: Emacs, Prev: Interpreters, Up: Top 25 GDB Text User Interface ************************** The GDB Text User Interface (TUI) is a terminal interface which uses the `curses' library to show the source file, the assembly output, the program registers and GDB commands in separate text windows. The TUI mode is supported only on platforms where a suitable version of the `curses' library is available. The TUI mode is enabled by default when you invoke GDB as `gdb -tui'. You can also switch in and out of TUI mode while GDB runs by using various TUI commands and key bindings, such as `tui enable' or `C-x C-a'. *Note TUI Commands: TUI Commands, and *Note TUI Key Bindings: TUI Keys. * Menu: * TUI Overview:: TUI overview * TUI Keys:: TUI key bindings * TUI Single Key Mode:: TUI single key mode * TUI Mouse Support:: TUI mouse support * TUI Commands:: TUI-specific commands * TUI Configuration:: TUI configuration variables  File: gdb.info, Node: TUI Overview, Next: TUI Keys, Up: TUI 25.1 TUI Overview ================= In TUI mode, GDB can display several text windows: _command_ This window is the GDB command window with the GDB prompt and the GDB output. The GDB input is still managed using readline. _source_ The source window shows the source file of the program. The current line and active breakpoints are displayed in this window. _assembly_ The assembly window shows the disassembly output of the program. _register_ This window shows the processor registers. Registers are highlighted when their values change. The source and assembly windows show the current program position by highlighting the current line and marking it with a `>' marker. By default, source and assembly code styling is disabled for the highlighted text, but you can enable it with the `set style tui-current-position on' command. *Note Output Styling::. Breakpoints are indicated with two markers. The first marker indicates the breakpoint type: `B' Breakpoint which was hit at least once. `b' Breakpoint which was never hit. `H' Hardware breakpoint which was hit at least once. `h' Hardware breakpoint which was never hit. The second marker indicates whether the breakpoint is enabled or not: `+' Breakpoint is enabled. `-' Breakpoint is disabled. The source, assembly and register windows are updated when the current thread changes, when the frame changes, or when the program counter changes. These windows are not all visible at the same time. The command window is always visible. The others can be arranged in several layouts: * source only, * assembly only, * source and assembly, * source and registers, or * assembly and registers. These are the standard layouts, but other layouts can be defined. A status line above the command window shows the following information: _target_ Indicates the current GDB target. (*note Specifying a Debugging Target: Targets.). _process_ Gives the current process or thread number. When no process is being debugged, this field is set to `No process'. _focus_ Shows the name of the TUI window that has the focus. _function_ Gives the current function name for the selected frame. The name is demangled if demangling is turned on (*note Print Settings::). When there is no symbol corresponding to the current program counter, the string `??' is displayed. _line_ Indicates the current line number for the selected frame. When the current line number is not known, the string `??' is displayed. _pc_ Indicates the current program counter address.  File: gdb.info, Node: TUI Keys, Next: TUI Single Key Mode, Prev: TUI Overview, Up: TUI 25.2 TUI Key Bindings ===================== The TUI installs several key bindings in the readline keymaps (*note Command Line Editing::). The following key bindings are installed for both TUI mode and the GDB standard mode. `C-x C-a' `C-x a' `C-x A' Enter or leave the TUI mode. When leaving the TUI mode, the curses window management stops and GDB operates using its standard mode, writing on the terminal directly. When reentering the TUI mode, control is given back to the curses windows. The screen is then refreshed. This key binding uses the bindable Readline function `tui-switch-mode'. `C-x 1' Use a TUI layout with only one window. The layout will either be `source' or `assembly'. When the TUI mode is not active, it will switch to the TUI mode. Think of this key binding as the Emacs `C-x 1' binding. This key binding uses the bindable Readline function `tui-delete-other-windows'. `C-x 2' Use a TUI layout with at least two windows. When the current layout already has two windows, the next layout with two windows is used. When a new layout is chosen, one window will always be common to the previous layout and the new one. Think of it as the Emacs `C-x 2' binding. This key binding uses the bindable Readline function `tui-change-windows'. `C-x o' Change the active window. The TUI associates several key bindings (like scrolling and arrow keys) with the active window. This command gives the focus to the next TUI window. Think of it as the Emacs `C-x o' binding. This key binding uses the bindable Readline function `tui-other-window'. `C-x s' Switch in and out of the TUI SingleKey mode that binds single keys to GDB commands (*note TUI Single Key Mode::). This key binding uses the bindable Readline function `next-keymap'. The following key bindings only work in the TUI mode: Scroll the active window one page up. Scroll the active window one page down. Scroll the active window one line up. Scroll the active window one line down. Scroll the active window one column left. Scroll the active window one column right. `C-L' Refresh the screen. Because the arrow keys scroll the active window in the TUI mode, they are not available for their normal use by readline unless the command window has the focus. When another window is active, you must use other readline key bindings such as `C-p', `C-n', `C-b' and `C-f' to control the command window.  File: gdb.info, Node: TUI Single Key Mode, Next: TUI Mouse Support, Prev: TUI Keys, Up: TUI 25.3 TUI Single Key Mode ======================== The TUI also provides a "SingleKey" mode, which binds several frequently used GDB commands to single keys. Type `C-x s' to switch into this mode, where the following key bindings are used: `c' continue `C' reverse-continue `d' down `f' finish `F' reverse-finish `n' next `N' reverse-next `o' nexti. The shortcut letter `o' stands for "step Over". `O' reverse-nexti `q' exit the SingleKey mode. `r' run `s' step `S' reverse-step `i' stepi. The shortcut letter `i' stands for "step Into". `I' reverse-stepi `u' up `v' info locals `w' where Other keys temporarily switch to the GDB command prompt. The key that was pressed is inserted in the editing buffer so that it is possible to type most GDB commands without interaction with the TUI SingleKey mode. Once the command is entered the TUI SingleKey mode is restored. The only way to permanently leave this mode is by typing `q' or `C-x s'. If GDB was built with Readline 8.0 or later, the TUI SingleKey keymap will be named `SingleKey'. This can be used in `.inputrc' to add additional bindings to this keymap.  File: gdb.info, Node: TUI Mouse Support, Next: TUI Commands, Prev: TUI Single Key Mode, Up: TUI 25.4 TUI Mouse Support ====================== If the curses library supports the mouse, the TUI supports mouse actions. The mouse wheel scrolls the appropriate window under the mouse cursor. The TUI itself does not directly support copying/pasting with the mouse. However, on Unix terminals, you can typically press and hold the key on your keyboard to temporarily bypass GDB's TUI and access the terminal's native mouse copy/paste functionality (commonly, click-drag-release or double-click to select text, middle-click to paste). This copy/paste works with the terminal's selection buffer, as opposed to the TUI's buffer. Alternatively, to disable mouse support in the TUI entirely and give the terminal control over mouse clicks, turn off the `tui mouse-events' setting (*note set tui mouse-events: tui-mouse-events.). Python extensions can react to mouse clicks (*note Window.click: python-window-click.).  File: gdb.info, Node: TUI Commands, Next: TUI Configuration, Prev: TUI Mouse Support, Up: TUI 25.5 TUI-specific Commands ========================== The TUI has specific commands to control the text windows. These commands are always available, even when GDB is not in the TUI mode. When GDB is in the standard mode, most of these commands will automatically switch to the TUI mode. Note that if GDB's `stdout' is not connected to a terminal, or GDB has been started with the machine interface interpreter (*note The GDB/MI Interface: GDB/MI.), most of these commands will fail with an error, because it would not be possible or desirable to enable curses window management. `tui enable' Activate TUI mode. The last active TUI window layout will be used if TUI mode has previously been used in the current debugging session, otherwise a default layout is used. `tui disable' Disable TUI mode, returning to the console interpreter. `info win' List the names and sizes of all currently displayed windows. `tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT...]' Create a new TUI layout. The new layout will be named NAME, and can be accessed using the `layout' command (see below). Each WINDOW parameter is either the name of a window to display, or a window description. The windows will be displayed from top to bottom in the order listed. The names of the windows are the same as the ones given to the `focus' command (see below); additionally, the `status' window can be specified. Note that, because it is of fixed height, the weight assigned to the status window is of no importance. It is conventional to use `0' here. A window description looks a bit like an invocation of `tui new-layout', and is of the form {[`-horizontal']WINDOW WEIGHT [WINDOW WEIGHT...]}. This specifies a sub-layout. If `-horizontal' is given, the windows in this description will be arranged side-by-side, rather than top-to-bottom. Each WEIGHT is an integer. It is the weight of this window relative to all the other windows in the layout. These numbers are used to calculate how much of the screen is given to each window. For example: (gdb) tui new-layout example src 1 regs 1 status 0 cmd 1 Here, the new layout is called `example'. It shows the source and register windows, followed by the status window, and then finally the command window. The non-status windows all have the same weight, so the terminal will be split into three roughly equal sections. Here is a more complex example, showing a horizontal layout: (gdb) tui new-layout example {-horizontal src 1 asm 1} 2 status 0 cmd 1 This will result in side-by-side source and assembly windows; with the status and command window being beneath these, filling the entire width of the terminal. Because they have weight 2, the source and assembly windows will be twice the height of the command window. `tui layout NAME' `layout NAME' Changes which TUI windows are displayed. The NAME parameter controls which layout is shown. It can be either one of the built-in layout names, or the name of a layout defined by the user using `tui new-layout'. The built-in layouts are as follows: `next' Display the next layout. `prev' Display the previous layout. `src' Display the source and command windows. `asm' Display the assembly and command windows. `split' Display the source, assembly, and command windows. `regs' When in `src' layout display the register, source, and command windows. When in `asm' or `split' layout display the register, assembler, and command windows. `tui focus NAME' `focus NAME' Changes which TUI window is currently active for scrolling. The NAME parameter can be any of the following: `next' Make the next window active for scrolling. `prev' Make the previous window active for scrolling. `src' Make the source window active for scrolling. `asm' Make the assembly window active for scrolling. `regs' Make the register window active for scrolling. `cmd' Make the command window active for scrolling. `tui refresh' `refresh' Refresh the screen. This is similar to typing `C-L'. `tui reg GROUP' Changes the register group displayed in the tui register window to GROUP. If the register window is not currently displayed this command will cause the register window to be displayed. The list of register groups, as well as their order is target specific. The following groups are available on most targets: `next' Repeatedly selecting this group will cause the display to cycle through all of the available register groups. `prev' Repeatedly selecting this group will cause the display to cycle through all of the available register groups in the reverse order to NEXT. `general' Display the general registers. `float' Display the floating point registers. `system' Display the system registers. `vector' Display the vector registers. `all' Display all registers. `update' Update the source window and the current execution point. `tui window height NAME +COUNT' `tui window height NAME -COUNT' `winheight NAME +COUNT' `winheight NAME -COUNT' Change the height of the window NAME by COUNT lines. Positive counts increase the height, while negative counts decrease it. The NAME parameter can be the name of any currently visible window. The names of the currently visible windows can be discovered using `info win' (*note info win: info_win_command.). The set of currently visible windows must always fill the terminal, and so, it is only possible to resize on window if there are other visible windows that can either give or receive the extra terminal space. `tui window width NAME +COUNT' `tui window width NAME -COUNT' `winwidth NAME +COUNT' `winwidth NAME -COUNT' Change the width of the window NAME by COUNT columns. Positive counts increase the width, while negative counts decrease it. The NAME parameter can be the name of any currently visible window. The names of the currently visible windows can be discovered using `info win' (*note info win: info_win_command.). The set of currently visible windows must always fill the terminal, and so, it is only possible to resize on window if there are other visible windows that can either give or receive the extra terminal space.  File: gdb.info, Node: TUI Configuration, Prev: TUI Commands, Up: TUI 25.6 TUI Configuration Variables ================================ Several configuration variables control the appearance of TUI windows. `set tui border-kind KIND' Select the border appearance for the source, assembly and register windows. The possible values are the following: `space' Use a space character to draw the border. `ascii' Use ASCII characters `+', `-' and `|' to draw the border. `acs' Use the Alternate Character Set to draw the border. The border is drawn using character line graphics if the terminal supports them. `set tui border-mode MODE' `set tui active-border-mode MODE' Select the display attributes for the borders of the inactive windows or the active window. The MODE can be one of the following: `normal' Use normal attributes to display the border. `standout' Use standout mode. `reverse' Use reverse video mode. `half' Use half bright mode. `half-standout' Use half bright and standout mode. `bold' Use extra bright or bold mode. `bold-standout' Use extra bright or bold and standout mode. `set tui tab-width NCHARS' Set the width of tab stops to be NCHARS characters. This setting affects the display of TAB characters in the source and assembly windows. `set tui compact-source [on|off]' Set whether the TUI source window is displayed in "compact" form. The default display uses more space for line numbers; the compact display uses only as much space as is needed for the line numbers in the current file. `set tui mouse-events [on|off]' When on (default), mouse clicks control the TUI (*note TUI Mouse Support::). When off, mouse clicks are handled by the terminal, enabling terminal-native text selection. `set debug tui [on|off]' Turn on or off display of GDB internal debug messages relating to the TUI. `show debug tui' Show the current status of displaying GDB internal debug messages relating to the TUI. Note that the colors of the TUI borders can be controlled using the appropriate `set style' commands. *Note Output Styling::.  File: gdb.info, Node: Emacs, Next: GDB/MI, Prev: TUI, Up: Top 26 Using GDB under GNU Emacs **************************** A special interface allows you to use GNU Emacs to view (and edit) the source files for the program you are debugging with GDB. To use this interface, use the command `M-x gdb' in Emacs. Give the executable file you want to debug as an argument. This command starts GDB as a subprocess of Emacs, with input and output through a newly created Emacs buffer. Running GDB under Emacs can be just like running GDB normally except for two things: * All "terminal" input and output goes through an Emacs buffer, called the GUD buffer. This applies both to GDB commands and their output, and to the input and output done by the program you are debugging. This is useful because it means that you can copy the text of previous commands and input them again; you can even use parts of the output in this way. All the facilities of Emacs' Shell mode are available for interacting with your program. In particular, you can send signals the usual way--for example, `C-c C-c' for an interrupt, `C-c C-z' for a stop. * GDB displays source code through Emacs. Each time GDB displays a stack frame, Emacs automatically finds the source file for that frame and puts an arrow (`=>') at the left margin of the current line. Emacs uses a separate buffer for source display, and splits the screen to show both your GDB session and the source. Explicit GDB `list' or search commands still produce output as usual, but you probably have no reason to use them from Emacs. We call this "text command mode". Emacs 22.1, and later, also uses a graphical mode, enabled by default, which provides further buffers that can control the execution and describe the state of your program. *Note GDB Graphical Interface: (Emacs)GDB Graphical Interface. If you specify an absolute file name when prompted for the `M-x gdb' argument, then Emacs sets your current working directory to where your program resides. If you only specify the file name, then Emacs sets your current working directory to the directory associated with the previous buffer. In this case, GDB may find your program by searching your environment's `PATH' variable, but on some operating systems it might not find the source. So, although the GDB input and output session proceeds normally, the auxiliary buffer does not display the current source and line of execution. The initial working directory of GDB is printed on the top line of the GUD buffer and this serves as a default for the commands that specify files for GDB to operate on. *Note Commands to Specify Files: Files. By default, `M-x gdb' calls the program called `gdb'. If you need to call GDB by a different name (for example, if you keep several configurations around, with different names) you can customize the Emacs variable `gud-gdb-command-name' to run the one you want. In the GUD buffer, you can use these special Emacs commands in addition to the standard Shell mode commands: `C-h m' Describe the features of Emacs' GUD Mode. `C-c C-s' Execute to another source line, like the GDB `step' command; also update the display window to show the current file and location. `C-c C-n' Execute to next source line in this function, skipping all function calls, like the GDB `next' command. Then update the display window to show the current file and location. `C-c C-i' Execute one instruction, like the GDB `stepi' command; update display window accordingly. `C-c C-f' Execute until exit from the selected stack frame, like the GDB `finish' command. `C-c C-r' Continue execution of your program, like the GDB `continue' command. `C-c <' Go up the number of frames indicated by the numeric argument (*note Numeric Arguments: (Emacs)Arguments.), like the GDB `up' command. `C-c >' Go down the number of frames indicated by the numeric argument, like the GDB `down' command. In any source file, the Emacs command `C-x ' (`gud-break') tells GDB to set a breakpoint on the source line point is on. In text command mode, if you type `M-x speedbar', Emacs displays a separate frame which shows a backtrace when the GUD buffer is current. Move point to any frame in the stack and type to make it become the current frame and display the associated source in the source buffer. Alternatively, click `Mouse-2' to make the selected frame become the current one. In graphical mode, the speedbar displays watch expressions. If you accidentally delete the source-display buffer, an easy way to get it back is to type the command `f' in the GDB buffer, to request a frame display; when you run under Emacs, this recreates the source buffer if necessary to show you the context of the current frame. The source files displayed in Emacs are in ordinary Emacs buffers which are visiting the source files in the usual way. You can edit the files with these buffers if you wish; but keep in mind that GDB communicates with Emacs in terms of line numbers. If you add or delete lines from the text, the line numbers that GDB knows cease to correspond properly with the code. A more detailed description of Emacs' interaction with GDB is given in the Emacs manual (*note Debuggers: (Emacs)Debuggers.).  File: gdb.info, Node: GDB/MI, Next: Annotations, Prev: Emacs, Up: Top 27 The GDB/MI Interface *********************** Function and Purpose ==================== GDB/MI is a line based machine oriented text interface to GDB and is activated by specifying using the `--interpreter' command line option (*note Mode Options::). It is specifically intended to support the development of systems which use the debugger as just one small component of a larger system. This chapter is a specification of the GDB/MI interface. It is written in the form of a reference manual. Note that GDB/MI is still under construction, so some of the features described below are incomplete and subject to change (*note GDB/MI Development and Front Ends: GDB/MI Development and Front Ends.). Notation and Terminology ======================== This chapter uses the following notation: * `|' separates two alternatives. * `[ SOMETHING ]' indicates that SOMETHING is optional: it may or may not be given. * `( GROUP )*' means that GROUP inside the parentheses may repeat zero or more times. * `( GROUP )+' means that GROUP inside the parentheses may repeat one or more times. * `( GROUP )' means that GROUP inside the parentheses occurs exactly once. * `"STRING"' means a literal STRING. * Menu: * GDB/MI General Design:: * GDB/MI Command Syntax:: * GDB/MI Compatibility with CLI:: * GDB/MI Development and Front Ends:: * GDB/MI Output Records:: * GDB/MI Simple Examples:: * GDB/MI Command Description Format:: * GDB/MI Breakpoint Commands:: * GDB/MI Catchpoint Commands:: * GDB/MI Program Context:: * GDB/MI Thread Commands:: * GDB/MI Ada Tasking Commands:: * GDB/MI Program Execution:: * GDB/MI Stack Manipulation:: * GDB/MI Variable Objects:: * GDB/MI Data Manipulation:: * GDB/MI Tracepoint Commands:: * GDB/MI Symbol Query:: * GDB/MI File Commands:: * GDB/MI Target Manipulation:: * GDB/MI File Transfer Commands:: * GDB/MI Ada Exceptions Commands:: * GDB/MI Support Commands:: * GDB/MI Miscellaneous Commands::  File: gdb.info, Node: GDB/MI General Design, Next: GDB/MI Command Syntax, Up: GDB/MI 27.1 GDB/MI General Design ========================== Interaction of a GDB/MI frontend with GDB involves three parts--commands sent to GDB, responses to those commands and notifications. Each command results in exactly one response, indicating either successful completion of the command, or an error. For the commands that do not resume the target, the response contains the requested information. For the commands that resume the target, the response only indicates whether the target was successfully resumed. Notifications is the mechanism for reporting changes in the state of the target, or in GDB state, that cannot conveniently be associated with a command and reported as part of that command response. The important examples of notifications are: * Exec notifications. These are used to report changes in target state--when a target is resumed, or stopped. It would not be feasible to include this information in response of resuming commands, because one resume commands can result in multiple events in different threads. Also, quite some time may pass before any event happens in the target, while a frontend needs to know whether the resuming command itself was successfully executed. * Console output, and status notifications. Console output notifications are used to report output of CLI commands, as well as diagnostics for other commands. Status notifications are used to report the progress of a long-running operation. Naturally, including this information in command response would mean no output is produced until the command is finished, which is undesirable. * General notifications. Commands may have various side effects on the GDB or target state beyond their official purpose. For example, a command may change the selected thread. Although such changes can be included in command response, using notification allows for more orthogonal frontend design. There's no guarantee that whenever an MI command reports an error, GDB or the target are in any specific state, and especially, the state is not reverted to the state before the MI command was processed. Therefore, whenever an MI command results in an error, we recommend that the frontend refreshes all the information shown in the user interface. * Menu: * Context management:: * Asynchronous and non-stop modes:: * Thread groups::  File: gdb.info, Node: Context management, Next: Asynchronous and non-stop modes, Up: GDB/MI General Design 27.1.1 Context management ------------------------- 27.1.1.1 Threads and Frames ........................... In most cases when GDB accesses the target, this access is done in context of a specific thread and frame (*note Frames::). Often, even when accessing global data, the target requires that a thread be specified. The CLI interface maintains the selected thread and frame, and supplies them to target on each command. This is convenient, because a command line user would not want to specify that information explicitly on each command, and because user interacts with GDB via a single terminal, so no confusion is possible as to what thread and frame are the current ones. In the case of MI, the concept of selected thread and frame is less useful. First, a frontend can easily remember this information itself. Second, a graphical frontend can have more than one window, each one used for debugging a different thread, and the frontend might want to access additional threads for internal purposes. This increases the risk that by relying on implicitly selected thread, the frontend may be operating on a wrong one. Therefore, each MI command should explicitly specify which thread and frame to operate on. To make it possible, each MI command accepts the `--thread' and `--frame' options, the value to each is GDB global identifier for thread and frame to operate on. Usually, each top-level window in a frontend allows the user to select a thread and a frame, and remembers the user selection for further operations. However, in some cases GDB may suggest that the current thread or frame be changed. For example, when stopping on a breakpoint it is reasonable to switch to the thread where breakpoint is hit. For another example, if the user issues the CLI `thread' or `frame' commands via the frontend, it is desirable to change the frontend's selection to the one specified by user. GDB communicates the suggestion to change current thread and frame using the `=thread-selected' notification. Note that historically, MI shares the selected thread with CLI, so frontends used the `-thread-select' to execute commands in the right context. However, getting this to work right is cumbersome. The simplest way is for frontend to emit `-thread-select' command before every command. This doubles the number of commands that need to be sent. The alternative approach is to suppress `-thread-select' if the selected thread in GDB is supposed to be identical to the thread the frontend wants to operate on. However, getting this optimization right can be tricky. In particular, if the frontend sends several commands to GDB, and one of the commands changes the selected thread, then the behaviour of subsequent commands will change. So, a frontend should either wait for response from such problematic commands, or explicitly add `-thread-select' for all subsequent commands. No frontend is known to do this exactly right, so it is suggested to just always pass the `--thread' and `--frame' options. 27.1.1.2 Language ................. The execution of several commands depends on which language is selected. By default, the current language (*note show language::) is used. But for commands known to be language-sensitive, it is recommended to use the `--language' option. This option takes one argument, which is the name of the language to use while executing the command. For instance: -data-evaluate-expression --language c "sizeof (void*)" ^done,value="4" (gdb) The valid language names are the same names accepted by the `set language' command (*note Manually::), excluding `auto', `local' or `unknown'.  File: gdb.info, Node: Asynchronous and non-stop modes, Next: Thread groups, Prev: Context management, Up: GDB/MI General Design 27.1.2 Asynchronous command execution and non-stop mode ------------------------------------------------------- On some targets, GDB is capable of processing MI commands even while the target is running. This is called "asynchronous command execution" (*note Background Execution::). The frontend may specify a preference for asynchronous execution using the `-gdb-set mi-async 1' command, which should be emitted before either running the executable or attaching to the target. After the frontend has started the executable or attached to the target, it can find if asynchronous execution is enabled using the `-list-target-features' command. `-gdb-set mi-async [on|off]' Set whether MI is in asynchronous mode. When `off', which is the default, MI execution commands (e.g., `-exec-continue') are foreground commands, and GDB waits for the program to stop before processing further commands. When `on', MI execution commands are background execution commands (e.g., `-exec-continue' becomes the equivalent of the `c&' CLI command), and so GDB is capable of processing MI commands even while the target is running. `-gdb-show mi-async' Show whether MI asynchronous mode is enabled. Note: In GDB version 7.7 and earlier, this option was called `target-async' instead of `mi-async', and it had the effect of both putting MI in asynchronous mode and making CLI background commands possible. CLI background commands are now always possible "out of the box" if the target supports them. The old spelling is kept as a deprecated alias for backwards compatibility. Even if GDB can accept a command while target is running, many commands that access the target do not work when the target is running. Therefore, asynchronous command execution is most useful when combined with non-stop mode (*note Non-Stop Mode::). Then, it is possible to examine the state of one thread, while other threads are running. When a given thread is running, MI commands that try to access the target in the context of that thread may not work, or may work only on some targets. In particular, commands that try to operate on thread's stack will not work, on any target. Commands that read memory, or modify breakpoints, may work or not work, depending on the target. Note that even commands that operate on global state, such as `print', `set', and breakpoint commands, still access the target in the context of a specific thread, so frontend should try to find a stopped thread and perform the operation on that thread (using the `--thread' option). Which commands will work in the context of a running thread is highly target dependent. However, the two commands `-exec-interrupt', to stop a thread, and `-thread-info', to find the state of a thread, will always work.  File: gdb.info, Node: Thread groups, Prev: Asynchronous and non-stop modes, Up: GDB/MI General Design 27.1.3 Thread groups -------------------- GDB may be used to debug several processes at the same time. On some platforms, GDB may support debugging of several hardware systems, each one having several cores with several different processes running on each core. This section describes the MI mechanism to support such debugging scenarios. The key observation is that regardless of the structure of the target, MI can have a global list of threads, because most commands that accept the `--thread' option do not need to know what process that thread belongs to. Therefore, it is not necessary to introduce neither additional `--process' option, nor an notion of the current process in the MI interface. The only strictly new feature that is required is the ability to find how the threads are grouped into processes. To allow the user to discover such grouping, and to support arbitrary hierarchy of machines/cores/processes, MI introduces the concept of a "thread group". Thread group is a collection of threads and other thread groups. A thread group always has a string identifier, a type, and may have additional attributes specific to the type. A new command, `-list-thread-groups', returns the list of top-level thread groups, which correspond to processes that GDB is debugging at the moment. By passing an identifier of a thread group to the `-list-thread-groups' command, it is possible to obtain the members of specific thread group. To allow the user to easily discover processes, and other objects, he wishes to debug, a concept of "available thread group" is introduced. Available thread group is an thread group that GDB is not debugging, but that can be attached to, using the `-target-attach' command. The list of available top-level thread groups can be obtained using `-list-thread-groups --available'. In general, the content of a thread group may be only retrieved only after attaching to that thread group. Thread groups are related to inferiors (*note Inferiors Connections and Programs::). Each inferior corresponds to a thread group of a special type `process', and some additional operations are permitted on such thread groups.  File: gdb.info, Node: GDB/MI Command Syntax, Next: GDB/MI Compatibility with CLI, Prev: GDB/MI General Design, Up: GDB/MI 27.2 GDB/MI Command Syntax ========================== * Menu: * GDB/MI Input Syntax:: * GDB/MI Output Syntax::  File: gdb.info, Node: GDB/MI Input Syntax, Next: GDB/MI Output Syntax, Up: GDB/MI Command Syntax 27.2.1 GDB/MI Input Syntax -------------------------- `COMMAND ==>' `CLI-COMMAND | MI-COMMAND' `CLI-COMMAND ==>' `[ TOKEN ] CLI-COMMAND NL', where CLI-COMMAND is any existing GDB CLI command. `MI-COMMAND ==>' `[ TOKEN ] "-" OPERATION ( " " OPTION )* `[' " --" `]' ( " " PARAMETER )* NL' `TOKEN ==>' "any sequence of digits" `OPTION ==>' `"-" PARAMETER [ " " PARAMETER ]' `PARAMETER ==>' `NON-BLANK-SEQUENCE | C-STRING' `OPERATION ==>' _any of the operations described in this chapter_ `NON-BLANK-SEQUENCE ==>' _anything, provided it doesn't contain special characters such as "-", NL, """ and of course " "_ `C-STRING ==>' `""" SEVEN-BIT-ISO-C-STRING-CONTENT """' `NL ==>' `CR | CR-LF' Notes: * The CLI commands are still handled by the MI interpreter; their output is described below. * The `TOKEN', when present, is passed back when the command finishes. * Some MI commands accept optional arguments as part of the parameter list. Each option is identified by a leading `-' (dash) and may be followed by an optional argument parameter. Options occur first in the parameter list and can be delimited from normal parameters using `--' (this is useful when some parameters begin with a dash). Pragmatics: * We want easy access to the existing CLI syntax (for debugging). * We want it to be easy to spot a MI operation.  File: gdb.info, Node: GDB/MI Output Syntax, Prev: GDB/MI Input Syntax, Up: GDB/MI Command Syntax 27.2.2 GDB/MI Output Syntax --------------------------- The output from GDB/MI consists of zero or more out-of-band records followed, optionally, by a single result record. This result record is for the most recent command. The sequence of output records is terminated by `(gdb)'. If an input command was prefixed with a `TOKEN' then the corresponding output for that command will also be prefixed by that same TOKEN. `OUTPUT ==>' `( OUT-OF-BAND-RECORD )* [ RESULT-RECORD ] "(gdb)" NL' `RESULT-RECORD ==>' ` [ TOKEN ] "^" RESULT-CLASS ( "," RESULT )* NL' `OUT-OF-BAND-RECORD ==>' `ASYNC-RECORD | STREAM-RECORD' `ASYNC-RECORD ==>' `EXEC-ASYNC-OUTPUT | STATUS-ASYNC-OUTPUT | NOTIFY-ASYNC-OUTPUT' `EXEC-ASYNC-OUTPUT ==>' `[ TOKEN ] "*" ASYNC-OUTPUT NL' `STATUS-ASYNC-OUTPUT ==>' `[ TOKEN ] "+" ASYNC-OUTPUT NL' `NOTIFY-ASYNC-OUTPUT ==>' `[ TOKEN ] "=" ASYNC-OUTPUT NL' `ASYNC-OUTPUT ==>' `ASYNC-CLASS ( "," RESULT )*' `RESULT-CLASS ==>' `"done" | "running" | "connected" | "error" | "exit"' `ASYNC-CLASS ==>' `"stopped" | OTHERS' (where OTHERS will be added depending on the needs--this is still in development). `RESULT ==>' ` VARIABLE "=" VALUE' `VARIABLE ==>' ` STRING ' `VALUE ==>' ` CONST | TUPLE | LIST ' `CONST ==>' `C-STRING' `TUPLE ==>' ` "{}" | "{" RESULT ( "," RESULT )* "}" ' `LIST ==>' ` "[]" | "[" VALUE ( "," VALUE )* "]" | "[" RESULT ( "," RESULT )* "]" ' `STREAM-RECORD ==>' `CONSOLE-STREAM-OUTPUT | TARGET-STREAM-OUTPUT | LOG-STREAM-OUTPUT' `CONSOLE-STREAM-OUTPUT ==>' `"~" C-STRING NL' `TARGET-STREAM-OUTPUT ==>' `"@@" C-STRING NL' `LOG-STREAM-OUTPUT ==>' `"&" C-STRING NL' `NL ==>' `CR | CR-LF' `TOKEN ==>' _any sequence of digits_. Notes: * All output sequences end in a single line containing a period. * The `TOKEN' is from the corresponding request. Note that for all async output, while the token is allowed by the grammar and may be output by future versions of GDB for select async output messages, it is generally omitted. Frontends should treat all async output as reporting general changes in the state of the target and there should be no need to associate async output to any prior command. * STATUS-ASYNC-OUTPUT contains on-going status information about the progress of a slow operation. It can be discarded. All status output is prefixed by `+'. * EXEC-ASYNC-OUTPUT contains asynchronous state change on the target (stopped, started, disappeared). All async output is prefixed by `*'. * NOTIFY-ASYNC-OUTPUT contains supplementary information that the client should handle (e.g., a new breakpoint information). All notify output is prefixed by `='. * CONSOLE-STREAM-OUTPUT is output that should be displayed as is in the console. It is the textual response to a CLI command. All the console output is prefixed by `~'. * TARGET-STREAM-OUTPUT is the output produced by the target program. All the target output is prefixed by `@@'. * LOG-STREAM-OUTPUT is output text coming from GDB's internals, for instance messages that should be displayed as part of an error log. All the log output is prefixed by `&'. * New GDB/MI commands should only output LISTS containing VALUES. *Note GDB/MI Stream Records: GDB/MI Stream Records, for more details about the various output records.  File: gdb.info, Node: GDB/MI Compatibility with CLI, Next: GDB/MI Development and Front Ends, Prev: GDB/MI Command Syntax, Up: GDB/MI 27.3 GDB/MI Compatibility with CLI ================================== For the developers convenience CLI commands can be entered directly, but there may be some unexpected behaviour. For example, commands that query the user will behave as if the user replied yes, breakpoint command lists are not executed and some CLI commands, such as `if', `when' and `define', prompt for further input with `>', which is not valid MI output. This feature may be removed at some stage in the future and it is recommended that front ends use the `-interpreter-exec' command (*note -interpreter-exec::).  File: gdb.info, Node: GDB/MI Development and Front Ends, Next: GDB/MI Output Records, Prev: GDB/MI Compatibility with CLI, Up: GDB/MI 27.4 GDB/MI Development and Front Ends ====================================== The application which takes the MI output and presents the state of the program being debugged to the user is called a "front end". Since GDB/MI is used by a variety of front ends to GDB, changes to the MI interface may break existing usage. This section describes how the protocol changes and how to request previous version of the protocol when it does. Some changes in MI need not break a carefully designed front end, and for these the MI version will remain unchanged. The following is a list of changes that may occur within one level, so front ends should parse MI output in a way that can handle them: * New MI commands may be added. * New fields may be added to the output of any MI command. * The range of values for fields with specified values, e.g., `in_scope' (*note -var-update::) may be extended. If the changes are likely to break front ends, the MI version level will be increased by one. The new versions of the MI protocol are not compatible with the old versions. Old versions of MI remain available, allowing front ends to keep using them until they are modified to use the latest MI version. Since `--interpreter=mi' always points to the latest MI version, it is recommended that front ends request a specific version of MI when launching GDB (e.g. `--interpreter=mi2') to make sure they get an interpreter with the MI version they expect. The following table gives a summary of the released versions of the MI interface: the version number, the version of GDB in which it first appeared and the breaking changes compared to the previous version. MI GDB Breaking changes version version --------------------------------------------------------------------------- 1 5.1 None 2 6.0 * The `-environment-pwd', `-environment-directory' and `-environment-path' commands now returns values using the MI output syntax, rather than CLI output syntax. * `-var-list-children''s `children' result field is now a list, rather than a tuple. * `-var-update''s `changelist' result field is now a list, rather than a tuple. 3 9.1 * The output of information about multi-location breakpoints has changed in the responses to the `-break-insert' and `-break-info' commands, as well as in the `=breakpoint-created' and `=breakpoint-modified' events. The multiple locations are now placed in a `locations' field, whose value is a list. 4 13.1 * The syntax of the "script" field in breakpoint output has changed in the responses to the `-break-insert' and `-break-info' commands, as well as the `=breakpoint-created' and `=breakpoint-modified' events. The previous output was syntactically invalid. The new output is a list. If your front end cannot yet migrate to a more recent version of the MI protocol, you can nevertheless selectively enable specific features available in those recent MI versions, using the following commands: `-fix-multi-location-breakpoint-output' Use the output for multi-location breakpoints which was introduced by MI 3, even when using MI versions below 3. This command has no effect when using MI version 3 or later. `-fix-breakpoint-script-output' Use the output for the breakpoint "script" field which was introduced by MI 4, even when using MI versions below 4. This command has no effect when using MI version 4 or later. The best way to avoid unexpected changes in MI that might break your front end is to make your project known to GDB developers and follow development on and .  File: gdb.info, Node: GDB/MI Output Records, Next: GDB/MI Simple Examples, Prev: GDB/MI Development and Front Ends, Up: GDB/MI 27.5 GDB/MI Output Records ========================== * Menu: * GDB/MI Result Records:: * GDB/MI Stream Records:: * GDB/MI Async Records:: * GDB/MI Breakpoint Information:: * GDB/MI Frame Information:: * GDB/MI Thread Information:: * GDB/MI Ada Exception Information::  File: gdb.info, Node: GDB/MI Result Records, Next: GDB/MI Stream Records, Up: GDB/MI Output Records 27.5.1 GDB/MI Result Records ---------------------------- In addition to a number of out-of-band notifications, the response to a GDB/MI command includes one of the following result indications: `"^done" [ "," RESULTS ]' The synchronous operation was successful, `RESULTS' are the return values. `"^running"' This result record is equivalent to `^done'. Historically, it was output instead of `^done' if the command has resumed the target. This behaviour is maintained for backward compatibility, but all frontends should treat `^done' and `^running' identically and rely on the `*running' output record to determine which threads are resumed. `"^connected"' GDB has connected to a remote target. `"^error" "," "msg=" C-STRING [ "," "code=" C-STRING ]' The operation failed. The `msg=C-STRING' variable contains the corresponding error message. If present, the `code=C-STRING' variable provides an error code on which consumers can rely on to detect the corresponding error condition. At present, only one error code is defined: `"undefined-command"' Indicates that the command causing the error does not exist. `"^exit"' GDB has terminated.  File: gdb.info, Node: GDB/MI Stream Records, Next: GDB/MI Async Records, Prev: GDB/MI Result Records, Up: GDB/MI Output Records 27.5.2 GDB/MI Stream Records ---------------------------- GDB internally maintains a number of output streams: the console, the target, and the log. The output intended for each of these streams is funneled through the GDB/MI interface using "stream records". Each stream record begins with a unique "prefix character" which identifies its stream (*note GDB/MI Output Syntax: GDB/MI Output Syntax.). In addition to the prefix, each stream record contains a `STRING-OUTPUT'. This is either raw text (with an implicit new line) or a quoted C string (which does not contain an implicit newline). `"~" STRING-OUTPUT' The console output stream contains text that should be displayed in the CLI console window. It contains the textual responses to CLI commands. `"@@" STRING-OUTPUT' The target output stream contains any textual output from the running target. This is only present when GDB's event loop is truly asynchronous, which is currently only the case for remote targets. `"&" STRING-OUTPUT' The log stream contains debugging messages being produced by GDB's internals.  File: gdb.info, Node: GDB/MI Async Records, Next: GDB/MI Breakpoint Information, Prev: GDB/MI Stream Records, Up: GDB/MI Output Records 27.5.3 GDB/MI Async Records --------------------------- "Async" records are used to notify the GDB/MI client of additional changes that have occurred. Those changes can either be a consequence of GDB/MI commands (e.g., a breakpoint modified) or a result of target activity (e.g., target stopped). The following is the list of possible async records: `*running,thread-id="THREAD"' The target is now running. The THREAD field can be the global thread ID of the thread that is now running, and it can be `all' if all threads are running. The frontend should assume that no interaction with a running thread is possible after this notification is produced. The frontend should not assume that this notification is output only once for any command. GDB may emit this notification several times, either for different threads, because it cannot resume all threads together, or even for a single thread, if the thread must be stepped though some code before letting it run freely. `*stopped,reason="REASON",thread-id="ID",stopped-threads="STOPPED",core="CORE"' The target has stopped. The REASON field can have one of the following values: `breakpoint-hit' A breakpoint was reached. `watchpoint-trigger' A watchpoint was triggered. `read-watchpoint-trigger' A read watchpoint was triggered. `access-watchpoint-trigger' An access watchpoint was triggered. `function-finished' An -exec-finish or similar CLI command was accomplished. `location-reached' An -exec-until or similar CLI command was accomplished. `watchpoint-scope' A watchpoint has gone out of scope. `end-stepping-range' An -exec-next, -exec-next-instruction, -exec-step, -exec-step-instruction or similar CLI command was accomplished. `exited-signalled' The inferior exited because of a signal. `exited' The inferior exited. `exited-normally' The inferior exited normally. `signal-received' A signal was received by the inferior. `solib-event' The inferior has stopped due to a library being loaded or unloaded. This can happen when `stop-on-solib-events' (*note Files::) is set or when a `catch load' or `catch unload' catchpoint is in use (*note Set Catchpoints::). `fork' The inferior has forked. This is reported when `catch fork' (*note Set Catchpoints::) has been used. `vfork' The inferior has vforked. This is reported in when `catch vfork' (*note Set Catchpoints::) has been used. `syscall-entry' The inferior entered a system call. This is reported when `catch syscall' (*note Set Catchpoints::) has been used. `syscall-return' The inferior returned from a system call. This is reported when `catch syscall' (*note Set Catchpoints::) has been used. `exec' The inferior called `exec'. This is reported when `catch exec' (*note Set Catchpoints::) has been used. `no-history' There isn't enough history recorded to continue reverse execution. The ID field identifies the global thread ID of the thread that directly caused the stop - for example by hitting a breakpoint. Depending on whether all-stop mode is in effect (*note All-Stop Mode::), GDB may either stop all threads, or only the thread that directly triggered the stop. If all threads are stopped, the STOPPED field will have the value of `"all"'. Otherwise, the value of the STOPPED field will be a list of thread identifiers. Presently, this list will always include a single thread, but frontend should be prepared to see several threads in the list. The CORE field reports the processor core on which the stop event has happened. This field may be absent if such information is not available. `=thread-group-added,id="ID"' `=thread-group-removed,id="ID"' A thread group was either added or removed. The ID field contains the GDB identifier of the thread group. When a thread group is added, it generally might not be associated with a running process. When a thread group is removed, its id becomes invalid and cannot be used in any way. `=thread-group-started,id="ID",pid="PID"' A thread group became associated with a running program, either because the program was just started or the thread group was attached to a program. The ID field contains the GDB identifier of the thread group. The PID field contains process identifier, specific to the operating system. `=thread-group-exited,id="ID"[,exit-code="CODE"]' A thread group is no longer associated with a running program, either because the program has exited, or because it was detached from. The ID field contains the GDB identifier of the thread group. The CODE field is the exit code of the inferior; it exists only when the inferior exited with some code. `=thread-created,id="ID",group-id="GID"' `=thread-exited,id="ID",group-id="GID"' A thread either was created, or has exited. The ID field contains the global GDB identifier of the thread. The GID field identifies the thread group this thread belongs to. `=thread-selected,id="ID"[,frame="FRAME"]' Informs that the selected thread or frame were changed. This notification is not emitted as result of the `-thread-select' or `-stack-select-frame' commands, but is emitted whenever an MI command that is not documented to change the selected thread and frame actually changes them. In particular, invoking, directly or indirectly (via user-defined command), the CLI `thread' or `frame' commands, will generate this notification. Changing the thread or frame from another user interface (see *Note Interpreters::) will also generate this notification. The FRAME field is only present if the newly selected thread is stopped. See *Note GDB/MI Frame Information:: for the format of its value. We suggest that in response to this notification, front ends highlight the selected thread and cause subsequent commands to apply to that thread. `=library-loaded,...' Reports that a new library file was loaded by the program. This notification has 5 fields--ID, TARGET-NAME, HOST-NAME, SYMBOLS-LOADED and RANGES. The ID field is an opaque identifier of the library. For remote debugging case, TARGET-NAME and HOST-NAME fields give the name of the library file on the target, and on the host respectively. For native debugging, both those fields have the same value. The SYMBOLS-LOADED field is emitted only for backward compatibility and should not be relied on to convey any useful information. The THREAD-GROUP field, if present, specifies the id of the thread group in whose context the library was loaded. If the field is absent, it means the library was loaded in the context of all present thread groups. The RANGES field specifies the ranges of addresses belonging to this library. `=library-unloaded,...' Reports that a library was unloaded by the program. This notification has 3 fields--ID, TARGET-NAME and HOST-NAME with the same meaning as for the `=library-loaded' notification. The THREAD-GROUP field, if present, specifies the id of the thread group in whose context the library was unloaded. If the field is absent, it means the library was unloaded in the context of all present thread groups. `=traceframe-changed,num=TFNUM,tracepoint=TPNUM' `=traceframe-changed,end' Reports that the trace frame was changed and its new number is TFNUM. The number of the tracepoint associated with this trace frame is TPNUM. `=tsv-created,name=NAME,initial=INITIAL' Reports that the new trace state variable NAME is created with initial value INITIAL. `=tsv-deleted,name=NAME' `=tsv-deleted' Reports that the trace state variable NAME is deleted or all trace state variables are deleted. `=tsv-modified,name=NAME,initial=INITIAL[,current=CURRENT]' Reports that the trace state variable NAME is modified with the initial value INITIAL. The current value CURRENT of trace state variable is optional and is reported if the current value of trace state variable is known. `=breakpoint-created,bkpt={...}' `=breakpoint-modified,bkpt={...}' `=breakpoint-deleted,id=NUMBER' Reports that a breakpoint was created, modified, or deleted, respectively. Only user-visible breakpoints are reported to the MI user. The BKPT argument is of the same form as returned by the various breakpoint commands; *Note GDB/MI Breakpoint Commands::. The NUMBER is the ordinal number of the breakpoint. Note that if a breakpoint is emitted in the result record of a command, then it will not also be emitted in an async record. `=record-started,thread-group="ID",method="METHOD"[,format="FORMAT"]' `=record-stopped,thread-group="ID"' Execution log recording was either started or stopped on an inferior. The ID is the GDB identifier of the thread group corresponding to the affected inferior. The METHOD field indicates the method used to record execution. If the method in use supports multiple recording formats, FORMAT will be present and contain the currently used format. *Note Process Record and Replay::, for existing method and format values. `=cmd-param-changed,param=PARAM,value=VALUE' Reports that a parameter of the command `set PARAM' is changed to VALUE. In the multi-word `set' command, the PARAM is the whole parameter list to `set' command. For example, In command `set check type on', PARAM is `check type' and VALUE is `on'. `=memory-changed,thread-group=ID,addr=ADDR,len=LEN[,type="code"]' Reports that bytes from ADDR to DATA + LEN were written in an inferior. The ID is the identifier of the thread group corresponding to the affected inferior. The optional `type="code"' part is reported if the memory written to holds executable code.  File: gdb.info, Node: GDB/MI Breakpoint Information, Next: GDB/MI Frame Information, Prev: GDB/MI Async Records, Up: GDB/MI Output Records 27.5.4 GDB/MI Breakpoint Information ------------------------------------ When GDB reports information about a breakpoint, a tracepoint, a watchpoint, or a catchpoint, it uses a tuple with the following fields: `number' The breakpoint number. `type' The type of the breakpoint. For ordinary breakpoints this will be `breakpoint', but many values are possible. `catch-type' If the type of the breakpoint is `catchpoint', then this indicates the exact type of catchpoint. `disp' This is the breakpoint disposition--either `del', meaning that the breakpoint will be deleted at the next stop, or `keep', meaning that the breakpoint will not be deleted. `enabled' This indicates whether the breakpoint is enabled, in which case the value is `y', or disabled, in which case the value is `n'. Note that this is not the same as the field `enable'. `addr' The address of the breakpoint. This may be a hexadecimal number, giving the address; or the string `', for a pending breakpoint; or the string `', for a breakpoint with multiple locations. This field will not be present if no address can be determined. For example, a watchpoint does not have an address. `addr_flags' Optional field containing any flags related to the address. These flags are architecture-dependent; see *Note Architectures:: for their meaning for a particular CPU. `func' If known, the function in which the breakpoint appears. If not known, this field is not present. `filename' The name of the source file which contains this function, if known. If not known, this field is not present. `fullname' The full file name of the source file which contains this function, if known. If not known, this field is not present. `line' The line number at which this breakpoint appears, if known. If not known, this field is not present. `at' If the source file is not known, this field may be provided. If provided, this holds the address of the breakpoint, possibly followed by a symbol name. `pending' If this breakpoint is pending, this field is present and holds the text used to set the breakpoint, as entered by the user. `evaluated-by' Where this breakpoint's condition is evaluated, either `host' or `target'. `thread' If this is a thread-specific breakpoint, then this identifies the thread in which the breakpoint can trigger. `inferior' If this is an inferior-specific breakpoint, this this identifies the inferior in which the breakpoint can trigger. `task' If this breakpoint is restricted to a particular Ada task, then this field will hold the task identifier. `cond' If the breakpoint is conditional, this is the condition expression. `ignore' The ignore count of the breakpoint. `enable' The enable count of the breakpoint. `traceframe-usage' FIXME. `static-tracepoint-marker-string-id' For a static tracepoint, the name of the static tracepoint marker. `mask' For a masked watchpoint, this is the mask. `pass' A tracepoint's pass count. `original-location' The location of the breakpoint as originally specified by the user. This field is optional. `times' The number of times the breakpoint has been hit. `installed' This field is only given for tracepoints. This is either `y', meaning that the tracepoint is installed, or `n', meaning that it is not. `what' Some extra data, the exact contents of which are type-dependent. `locations' This field is present if the breakpoint has multiple locations. It is also exceptionally present if the breakpoint is enabled and has a single, disabled location. The value is a list of locations. The format of a location is described below. A location in a multi-location breakpoint is represented as a tuple with the following fields: `number' The location number as a dotted pair, like `1.2'. The first digit is the number of the parent breakpoint. The second digit is the number of the location within that breakpoint. `enabled' There are three possible values, with the following meanings: `y' The location is enabled. `n' The location is disabled by the user. `N' The location is disabled because the breakpoint condition is invalid at this location. `addr' The address of this location as an hexadecimal number. `addr_flags' Optional field containing any flags related to the address. These flags are architecture-dependent; see *Note Architectures:: for their meaning for a particular CPU. `func' If known, the function in which the location appears. If not known, this field is not present. `file' The name of the source file which contains this location, if known. If not known, this field is not present. `fullname' The full file name of the source file which contains this location, if known. If not known, this field is not present. `line' The line number at which this location appears, if known. If not known, this field is not present. `thread-groups' The thread groups this location is in. For example, here is what the output of `-break-insert' (*note GDB/MI Breakpoint Commands::) might be: -> -break-insert main <- ^done,bkpt={number="1",type="breakpoint",disp="keep", enabled="y",addr="0x08048564",func="main",file="myprog.c", fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"], times="0"} <- (gdb)  File: gdb.info, Node: GDB/MI Frame Information, Next: GDB/MI Thread Information, Prev: GDB/MI Breakpoint Information, Up: GDB/MI Output Records 27.5.5 GDB/MI Frame Information ------------------------------- Response from many MI commands includes an information about stack frame. This information is a tuple that may have the following fields: `level' The level of the stack frame. The innermost frame has the level of zero. This field is always present. `func' The name of the function corresponding to the frame. This field may be absent if GDB is unable to determine the function name. `addr' The code address for the frame. This field is always present. `addr_flags' Optional field containing any flags related to the address. These flags are architecture-dependent; see *Note Architectures:: for their meaning for a particular CPU. `file' The name of the source files that correspond to the frame's code address. This field may be absent. `line' The source line corresponding to the frames' code address. This field may be absent. `from' The name of the binary file (either executable or shared library) the corresponds to the frame's code address. This field may be absent.  File: gdb.info, Node: GDB/MI Thread Information, Next: GDB/MI Ada Exception Information, Prev: GDB/MI Frame Information, Up: GDB/MI Output Records 27.5.6 GDB/MI Thread Information -------------------------------- Whenever GDB has to report an information about a thread, it uses a tuple with the following fields. The fields are always present unless stated otherwise. `id' The global numeric id assigned to the thread by GDB. `target-id' The target-specific string identifying the thread. `details' Additional information about the thread provided by the target. It is supposed to be human-readable and not interpreted by the frontend. This field is optional. `name' The name of the thread. If the user specified a name using the `thread name' command, then this name is given. Otherwise, if GDB can extract the thread name from the target, then that name is given. If GDB cannot find the thread name, then this field is omitted. `state' The execution state of the thread, either `stopped' or `running', depending on whether the thread is presently running. `frame' The stack frame currently executing in the thread. This field is only present if the thread is stopped. Its format is documented in *Note GDB/MI Frame Information::. `core' The value of this field is an integer number of the processor core the thread was last seen on. This field is optional.  File: gdb.info, Node: GDB/MI Ada Exception Information, Prev: GDB/MI Thread Information, Up: GDB/MI Output Records 27.5.7 GDB/MI Ada Exception Information --------------------------------------- Whenever a `*stopped' record is emitted because the program stopped after hitting an exception catchpoint (*note Set Catchpoints::), GDB provides the name of the exception that was raised via the `exception-name' field. Also, for exceptions that were raised with an exception message, GDB provides that message via the `exception-message' field.  File: gdb.info, Node: GDB/MI Simple Examples, Next: GDB/MI Command Description Format, Prev: GDB/MI Output Records, Up: GDB/MI 27.6 Simple Examples of GDB/MI Interaction ========================================== This subsection presents several simple examples of interaction using the GDB/MI interface. In these examples, `->' means that the following line is passed to GDB/MI as input, while `<-' means the output received from GDB/MI. Note the line breaks shown in the examples are here only for readability, they don't appear in the real output. Setting a Breakpoint -------------------- Setting a breakpoint generates synchronous output which contains detailed information of the breakpoint. -> -break-insert main <- ^done,bkpt={number="1",type="breakpoint",disp="keep", enabled="y",addr="0x08048564",func="main",file="myprog.c", fullname="/home/nickrob/myprog.c",line="68",thread-groups=["i1"], times="0"} <- (gdb) Program Execution ----------------- Program execution generates asynchronous records and MI gives the reason that execution stopped. -> -exec-run <- ^running <- (gdb) <- *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", frame={addr="0x08048564",func="main", args=[{name="argc",value="1"},{name="argv",value="0xbfc4d4d4"}], file="myprog.c",fullname="/home/nickrob/myprog.c",line="68", arch="i386:x86_64"} <- (gdb) -> -exec-continue <- ^running <- (gdb) <- *stopped,reason="exited-normally" <- (gdb) Quitting GDB ------------ Quitting GDB just prints the result class `^exit'. -> (gdb) <- -gdb-exit <- ^exit Please note that `^exit' is printed immediately, but it might take some time for GDB to actually exit. During that time, GDB performs necessary cleanups, including killing programs being debugged or disconnecting from debug hardware, so the frontend should wait till GDB exits and should only forcibly kill GDB if it fails to exit in reasonable time. A Bad Command ------------- Here's what happens if you pass a non-existent command: -> -rubbish <- ^error,msg="Undefined MI command: rubbish" <- (gdb)  File: gdb.info, Node: GDB/MI Command Description Format, Next: GDB/MI Breakpoint Commands, Prev: GDB/MI Simple Examples, Up: GDB/MI 27.7 GDB/MI Command Description Format ====================================== The remaining sections describe blocks of commands. Each block of commands is laid out in a fashion similar to this section. Motivation ---------- The motivation for this collection of commands. Introduction ------------ A brief introduction to this collection of commands as a whole. Commands -------- For each command in the block, the following is described: Synopsis ........ -command ARGS... Result ...... GDB Command ........... The corresponding GDB CLI command(s), if any. Example ....... Example(s) formatted for readability. Some of the described commands have not been implemented yet and these are labeled N.A. (not available).  File: gdb.info, Node: GDB/MI Breakpoint Commands, Next: GDB/MI Catchpoint Commands, Prev: GDB/MI Command Description Format, Up: GDB/MI 27.8 GDB/MI Breakpoint Commands =============================== This section documents GDB/MI commands for manipulating breakpoints. The `-break-after' Command -------------------------- Synopsis ........ -break-after NUMBER COUNT The breakpoint number NUMBER is not in effect until it has been hit COUNT times. To see how this is reflected in the output of the `-break-list' command, see the description of the `-break-list' command below. GDB Command ........... The corresponding GDB command is `ignore'. Example ....... (gdb) -break-insert main ^done,bkpt={number="1",type="breakpoint",disp="keep", enabled="y",addr="0x000100d0",func="main",file="hello.c", fullname="/home/foo/hello.c",line="5",thread-groups=["i1"], times="0"} (gdb) -break-after 1 3 ~ ^done (gdb) -break-list ^done,BreakpointTable={nr_rows="1",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", line="5",thread-groups=["i1"],times="0",ignore="3"}]} (gdb) The `-break-commands' Command ----------------------------- Synopsis ........ -break-commands NUMBER [ COMMAND1 ... COMMANDN ] Specifies the CLI commands that should be executed when breakpoint NUMBER is hit. The parameters COMMAND1 to COMMANDN are the commands. If no command is specified, any previously-set commands are cleared. *Note Break Commands::. Typical use of this functionality is tracing a program, that is, printing of values of some variables whenever breakpoint is hit and then continuing. GDB Command ........... The corresponding GDB command is `commands'. Example ....... (gdb) -break-insert main ^done,bkpt={number="1",type="breakpoint",disp="keep", enabled="y",addr="0x000100d0",func="main",file="hello.c", fullname="/home/foo/hello.c",line="5",thread-groups=["i1"], times="0"} (gdb) -break-commands 1 "print v" "continue" ^done (gdb) The `-break-condition' Command ------------------------------ Synopsis ........ -break-condition [ --force ] NUMBER [ EXPR ] Breakpoint NUMBER will stop the program only if the condition in EXPR is true. The condition becomes part of the `-break-list' output (see the description of the `-break-list' command below). If the `--force' flag is passed, the condition is forcibly defined even when it is invalid for all locations of breakpoint NUMBER. If the EXPR argument is omitted, breakpoint NUMBER becomes unconditional. GDB Command ........... The corresponding GDB command is `condition'. Example ....... (gdb) -break-condition 1 1 ^done (gdb) -break-list ^done,BreakpointTable={nr_rows="1",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", line="5",cond="1",thread-groups=["i1"],times="0",ignore="3"}]} (gdb) The `-break-delete' Command --------------------------- Synopsis ........ -break-delete ( BREAKPOINT )+ Delete the breakpoint(s) whose number(s) are specified in the argument list. This is obviously reflected in the breakpoint list. GDB Command ........... The corresponding GDB command is `delete'. Example ....... (gdb) -break-delete 1 ^done (gdb) -break-list ^done,BreakpointTable={nr_rows="0",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[]} (gdb) The `-break-disable' Command ---------------------------- Synopsis ........ -break-disable ( BREAKPOINT )+ Disable the named BREAKPOINT(s). The field `enabled' in the break list is now set to `n' for the named BREAKPOINT(s). GDB Command ........... The corresponding GDB command is `disable'. Example ....... (gdb) -break-disable 2 ^done (gdb) -break-list ^done,BreakpointTable={nr_rows="1",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="n", addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", line="5",thread-groups=["i1"],times="0"}]} (gdb) The `-break-enable' Command --------------------------- Synopsis ........ -break-enable ( BREAKPOINT )+ Enable (previously disabled) BREAKPOINT(s). GDB Command ........... The corresponding GDB command is `enable'. Example ....... (gdb) -break-enable 2 ^done (gdb) -break-list ^done,BreakpointTable={nr_rows="1",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="y", addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c", line="5",thread-groups=["i1"],times="0"}]} (gdb) The `-break-info' Command ------------------------- Synopsis ........ -break-info BREAKPOINT Get information about a single breakpoint. The result is a table of breakpoints. *Note GDB/MI Breakpoint Information::, for details on the format of each breakpoint in the table. GDB Command ........... The corresponding GDB command is `info break BREAKPOINT'. Example ....... N.A. The `-break-insert' Command --------------------------- Synopsis ........ -break-insert [ -t ] [ -h ] [ -f ] [ -d ] [ -a ] [ --qualified ] [ -c CONDITION ] [ --force-condition ] [ -i IGNORE-COUNT ] [ -p THREAD-ID ] [ -g THREAD-GROUP-ID ] [ LOCSPEC ] If specified, LOCSPEC, can be one of: LINESPEC LOCATION A linespec location. *Note Linespec Locations::. EXPLICIT LOCATION An explicit location. GDB/MI explicit locations are analogous to the CLI's explicit locations using the option names listed below. *Note Explicit Locations::. `--source FILENAME' The source file name of the location. This option requires the use of either `--function' or `--line'. `--function FUNCTION' The name of a function or method. `--label LABEL' The name of a label. `--line LINEOFFSET' An absolute or relative line offset from the start of the location. ADDRESS LOCATION An address location, *ADDRESS. *Note Address Locations::. The possible optional parameters of this command are: `-t' Insert a temporary breakpoint. `-h' Insert a hardware breakpoint. `-f' If LOCSPEC cannot be resolved (for example if it refers to unknown files or functions), create a pending breakpoint. Without this flag, GDB will report an error, and won't create a breakpoint, if LOCSPEC cannot be parsed. `-d' Create a disabled breakpoint. `-a' Create a tracepoint. *Note Tracepoints::. When this parameter is used together with `-h', a fast tracepoint is created. `-c CONDITION' Make the breakpoint conditional on CONDITION. `--force-condition' Forcibly define the breakpoint even if the condition is invalid at all of the breakpoint locations. `-i IGNORE-COUNT' Initialize the IGNORE-COUNT. `-p THREAD-ID' Restrict the breakpoint to the thread with the specified global THREAD-ID. THREAD-ID must be a valid thread-id at the time the breakpoint is requested. Breakpoints created with a THREAD-ID will automatically be deleted when the corresponding thread exits. `-g THREAD-GROUP-ID' Restrict the breakpoint to the thread group with the specified THREAD-GROUP-ID. `--qualified' This option makes GDB interpret a function name specified as a complete fully-qualified name. Result ...... *Note GDB/MI Breakpoint Information::, for details on the format of the resulting breakpoint. Note: this format is open to change. GDB Command ........... The corresponding GDB commands are `break', `tbreak', `hbreak', and `thbreak'. Example ....... (gdb) -break-insert main ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c", fullname="/home/foo/recursive2.c,line="4",thread-groups=["i1"], times="0"} (gdb) -break-insert -t foo ^done,bkpt={number="2",addr="0x00010774",file="recursive2.c", fullname="/home/foo/recursive2.c,line="11",thread-groups=["i1"], times="0"} (gdb) -break-list ^done,BreakpointTable={nr_rows="2",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x0001072c", func="main",file="recursive2.c", fullname="/home/foo/recursive2.c,"line="4",thread-groups=["i1"], times="0"}, bkpt={number="2",type="breakpoint",disp="del",enabled="y", addr="0x00010774",func="foo",file="recursive2.c", fullname="/home/foo/recursive2.c",line="11",thread-groups=["i1"], times="0"}]} (gdb) The `-dprintf-insert' Command ----------------------------- Synopsis ........ -dprintf-insert [ -t ] [ -f ] [ -d ] [ --qualified ] [ -c CONDITION ] [--force-condition] [ -i IGNORE-COUNT ] [ -p THREAD-ID ] [ LOCSPEC ] FORMAT [ ARGUMENT... ] Insert a new dynamic print breakpoint at the given location. *Note Dynamic Printf::. FORMAT is the format to use, and any remaining arguments are passed as expressions to substitute. If supplied, LOCSPEC and `--qualified' may be specified the same way as for the `-break-insert' command. *Note -break-insert::. The possible optional parameters of this command are: `-t' Insert a temporary breakpoint. `-f' If LOCSPEC cannot be parsed (for example, if it refers to unknown files or functions), create a pending breakpoint. Without this flag, GDB will report an error, and won't create a breakpoint, if LOCSPEC cannot be parsed. `-d' Create a disabled breakpoint. `-c CONDITION' Make the breakpoint conditional on CONDITION. `--force-condition' Forcibly define the breakpoint even if the condition is invalid at all of the breakpoint locations. `-i IGNORE-COUNT' Set the ignore count of the breakpoint (*note ignore count: Conditions.) to IGNORE-COUNT. `-p THREAD-ID' Restrict the breakpoint to the thread with the specified global THREAD-ID. Result ...... *Note GDB/MI Breakpoint Information::, for details on the format of the resulting breakpoint. GDB Command ........... The corresponding GDB command is `dprintf'. Example ....... (gdb) 4-dprintf-insert foo "At foo entry\n" 4^done,bkpt={number="1",type="dprintf",disp="keep",enabled="y", addr="0x000000000040061b",func="foo",file="mi-dprintf.c", fullname="mi-dprintf.c",line="25",thread-groups=["i1"], times="0",script=["printf \"At foo entry\\n\"","continue"], original-location="foo"} (gdb) 5-dprintf-insert 26 "arg=%d, g=%d\n" arg g 5^done,bkpt={number="2",type="dprintf",disp="keep",enabled="y", addr="0x000000000040062a",func="foo",file="mi-dprintf.c", fullname="mi-dprintf.c",line="26",thread-groups=["i1"], times="0",script=["printf \"arg=%d, g=%d\\n\", arg, g","continue"], original-location="mi-dprintf.c:26"} (gdb) The `-break-list' Command ------------------------- Synopsis ........ -break-list Displays the list of inserted breakpoints, showing the following fields: `Number' number of the breakpoint `Type' type of the breakpoint: `breakpoint' or `watchpoint' `Disposition' should the breakpoint be deleted or disabled when it is hit: `keep' or `nokeep' `Enabled' is the breakpoint enabled or no: `y' or `n' `Address' memory location at which the breakpoint is set `What' logical location of the breakpoint, expressed by function name, file name, line number `Thread-groups' list of thread groups to which this breakpoint applies `Times' number of times the breakpoint has been hit If there are no breakpoints, watchpoints, tracepoints, or catchpoints, the `BreakpointTable' `body' field is an empty list. GDB Command ........... The corresponding GDB command is `info break'. Example ....... (gdb) -break-list ^done,BreakpointTable={nr_rows="2",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x000100d0",func="main",file="hello.c",line="5",thread-groups=["i1"], times="0"}, bkpt={number="2",type="breakpoint",disp="keep",enabled="y", addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c", line="13",thread-groups=["i1"],times="0"}]} (gdb) Here's an example of the result when there are no breakpoints: (gdb) -break-list ^done,BreakpointTable={nr_rows="0",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[]} (gdb) The `-break-passcount' Command ------------------------------ Synopsis ........ -break-passcount TRACEPOINT-NUMBER PASSCOUNT Set the passcount for tracepoint TRACEPOINT-NUMBER to PASSCOUNT. If the breakpoint referred to by TRACEPOINT-NUMBER is not a tracepoint, error is emitted. This corresponds to CLI command `passcount'. The `-break-watch' Command -------------------------- Synopsis ........ -break-watch [ -a | -r ] Create a watchpoint. With the `-a' option it will create an "access" watchpoint, i.e., a watchpoint that triggers either on a read from or on a write to the memory location. With the `-r' option, the watchpoint created is a "read" watchpoint, i.e., it will trigger only when the memory location is accessed for reading. Without either of the options, the watchpoint created is a regular watchpoint, i.e., it will trigger when the memory location is accessed for writing. *Note Setting Watchpoints: Set Watchpoints. Note that `-break-list' will report a single list of watchpoints and breakpoints inserted. GDB Command ........... The corresponding GDB commands are `watch', `awatch', and `rwatch'. Example ....... Setting a watchpoint on a variable in the `main' function: (gdb) -break-watch x ^done,wpt={number="2",exp="x"} (gdb) -exec-continue ^running (gdb) *stopped,reason="watchpoint-trigger",wpt={number="2",exp="x"}, value={old="-268439212",new="55"}, frame={func="main",args=[],file="recursive2.c", fullname="/home/foo/bar/recursive2.c",line="5",arch="i386:x86_64"} (gdb) Setting a watchpoint on a variable local to a function. GDB will stop the program execution twice: first for the variable changing value, then for the watchpoint going out of scope. (gdb) -break-watch C ^done,wpt={number="5",exp="C"} (gdb) -exec-continue ^running (gdb) *stopped,reason="watchpoint-trigger", wpt={number="5",exp="C"},value={old="-276895068",new="3"}, frame={func="callee4",args=[], file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13", arch="i386:x86_64"} (gdb) -exec-continue ^running (gdb) *stopped,reason="watchpoint-scope",wpnum="5", frame={func="callee3",args=[{name="strarg", value="0x11940 \"A string argument.\""}], file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18", arch="i386:x86_64"} (gdb) Listing breakpoints and watchpoints, at different points in the program execution. Note that once the watchpoint goes out of scope, it is deleted. (gdb) -break-watch C ^done,wpt={number="2",exp="C"} (gdb) -break-list ^done,BreakpointTable={nr_rows="2",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x00010734",func="callee4", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",thread-groups=["i1"], times="1"}, bkpt={number="2",type="watchpoint",disp="keep", enabled="y",addr="",what="C",thread-groups=["i1"],times="0"}]} (gdb) -exec-continue ^running (gdb) *stopped,reason="watchpoint-trigger",wpt={number="2",exp="C"}, value={old="-276895068",new="3"}, frame={func="callee4",args=[], file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13", arch="i386:x86_64"} (gdb) -break-list ^done,BreakpointTable={nr_rows="2",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x00010734",func="callee4", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",thread-groups=["i1"], times="1"}, bkpt={number="2",type="watchpoint",disp="keep", enabled="y",addr="",what="C",thread-groups=["i1"],times="-5"}]} (gdb) -exec-continue ^running ^done,reason="watchpoint-scope",wpnum="2", frame={func="callee3",args=[{name="strarg", value="0x11940 \"A string argument.\""}], file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18", arch="i386:x86_64"} (gdb) -break-list ^done,BreakpointTable={nr_rows="1",nr_cols="6", hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}, {width="14",alignment="-1",col_name="type",colhdr="Type"}, {width="4",alignment="-1",col_name="disp",colhdr="Disp"}, {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}, {width="10",alignment="-1",col_name="addr",colhdr="Address"}, {width="40",alignment="2",col_name="what",colhdr="What"}], body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x00010734",func="callee4", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8", thread-groups=["i1"],times="1"}]} (gdb)  File: gdb.info, Node: GDB/MI Catchpoint Commands, Next: GDB/MI Program Context, Prev: GDB/MI Breakpoint Commands, Up: GDB/MI 27.9 GDB/MI Catchpoint Commands =============================== This section documents GDB/MI commands for manipulating catchpoints. * Menu: * Shared Library GDB/MI Catchpoint Commands:: * Ada Exception GDB/MI Catchpoint Commands:: * C++ Exception GDB/MI Catchpoint Commands::  File: gdb.info, Node: Shared Library GDB/MI Catchpoint Commands, Next: Ada Exception GDB/MI Catchpoint Commands, Up: GDB/MI Catchpoint Commands 27.9.1 Shared Library GDB/MI Catchpoints ---------------------------------------- The `-catch-load' Command ------------------------- Synopsis ........ -catch-load [ -t ] [ -d ] REGEXP Add a catchpoint for library load events. If the `-t' option is used, the catchpoint is a temporary one (*note Setting Breakpoints: Set Breaks.). If the `-d' option is used, the catchpoint is created in a disabled state. The `regexp' argument is a regular expression used to match the name of the loaded library. GDB Command ........... The corresponding GDB command is `catch load'. Example ....... -catch-load -t foo.so ^done,bkpt={number="1",type="catchpoint",disp="del",enabled="y", what="load of library matching foo.so",catch-type="load",times="0"} (gdb) The `-catch-unload' Command --------------------------- Synopsis ........ -catch-unload [ -t ] [ -d ] REGEXP Add a catchpoint for library unload events. If the `-t' option is used, the catchpoint is a temporary one (*note Setting Breakpoints: Set Breaks.). If the `-d' option is used, the catchpoint is created in a disabled state. The `regexp' argument is a regular expression used to match the name of the unloaded library. GDB Command ........... The corresponding GDB command is `catch unload'. Example ....... -catch-unload -d bar.so ^done,bkpt={number="2",type="catchpoint",disp="keep",enabled="n", what="load of library matching bar.so",catch-type="unload",times="0"} (gdb)  File: gdb.info, Node: Ada Exception GDB/MI Catchpoint Commands, Next: C++ Exception GDB/MI Catchpoint Commands, Prev: Shared Library GDB/MI Catchpoint Commands, Up: GDB/MI Catchpoint Commands 27.9.2 Ada Exception GDB/MI Catchpoints --------------------------------------- The following GDB/MI commands can be used to create catchpoints that stop the execution when Ada exceptions are being raised. The `-catch-assert' Command --------------------------- Synopsis ........ -catch-assert [ -c CONDITION] [ -d ] [ -t ] Add a catchpoint for failed Ada assertions. The possible optional parameters for this command are: `-c CONDITION' Make the catchpoint conditional on CONDITION. `-d' Create a disabled catchpoint. `-t' Create a temporary catchpoint. GDB Command ........... The corresponding GDB command is `catch assert'. Example ....... -catch-assert ^done,bkptno="5",bkpt={number="5",type="breakpoint",disp="keep", enabled="y",addr="0x0000000000404888",what="failed Ada assertions", thread-groups=["i1"],times="0", original-location="__gnat_debug_raise_assert_failure"} (gdb) The `-catch-exception' Command ------------------------------ Synopsis ........ -catch-exception [ -c CONDITION] [ -d ] [ -e EXCEPTION-NAME ] [ -t ] [ -u ] Add a catchpoint stopping when Ada exceptions are raised. By default, the command stops the program when any Ada exception gets raised. But it is also possible, by using some of the optional parameters described below, to create more selective catchpoints. The possible optional parameters for this command are: `-c CONDITION' Make the catchpoint conditional on CONDITION. `-d' Create a disabled catchpoint. `-e EXCEPTION-NAME' Only stop when EXCEPTION-NAME is raised. This option cannot be used combined with `-u'. `-t' Create a temporary catchpoint. `-u' Stop only when an unhandled exception gets raised. This option cannot be used combined with `-e'. GDB Command ........... The corresponding GDB commands are `catch exception' and `catch exception unhandled'. Example ....... -catch-exception -e Program_Error ^done,bkptno="4",bkpt={number="4",type="breakpoint",disp="keep", enabled="y",addr="0x0000000000404874", what="`Program_Error' Ada exception", thread-groups=["i1"], times="0",original-location="__gnat_debug_raise_exception"} (gdb) The `-catch-handlers' Command ----------------------------- Synopsis ........ -catch-handlers [ -c CONDITION] [ -d ] [ -e EXCEPTION-NAME ] [ -t ] Add a catchpoint stopping when Ada exceptions are handled. By default, the command stops the program when any Ada exception gets handled. But it is also possible, by using some of the optional parameters described below, to create more selective catchpoints. The possible optional parameters for this command are: `-c CONDITION' Make the catchpoint conditional on CONDITION. `-d' Create a disabled catchpoint. `-e EXCEPTION-NAME' Only stop when EXCEPTION-NAME is handled. `-t' Create a temporary catchpoint. GDB Command ........... The corresponding GDB command is `catch handlers'. Example ....... -catch-handlers -e Constraint_Error ^done,bkptno="4",bkpt={number="4",type="breakpoint",disp="keep", enabled="y",addr="0x0000000000402f68", what="`Constraint_Error' Ada exception handlers",thread-groups=["i1"], times="0",original-location="__gnat_begin_handler"} (gdb)  File: gdb.info, Node: C++ Exception GDB/MI Catchpoint Commands, Prev: Ada Exception GDB/MI Catchpoint Commands, Up: GDB/MI Catchpoint Commands 27.9.3 C++ Exception GDB/MI Catchpoints --------------------------------------- The following GDB/MI commands can be used to create catchpoints that stop the execution when C++ exceptions are being throw, rethrown, or caught. The `-catch-throw' Command -------------------------- Synopsis ........ -catch-throw [ -t ] [ -r REGEXP] Stop when the debuggee throws a C++ exception. If REGEXP is given, then only exceptions whose type matches the regular expression will be caught. If `-t' is given, then the catchpoint is enabled only for one stop, the catchpoint is automatically deleted after stopping once for the event. GDB Command ........... The corresponding GDB commands are `catch throw' and `tcatch throw' (*note Set Catchpoints::). Example ....... -catch-throw -r exception_type ^done,bkpt={number="1",type="catchpoint",disp="keep",enabled="y", what="exception throw",catch-type="throw", thread-groups=["i1"], regexp="exception_type",times="0"} (gdb) -exec-run ^running (gdb) ~"\n" ~"Catchpoint 1 (exception thrown), 0x00007ffff7ae00ed in __cxa_throw () from /lib64/libstdc++.so.6\n" *stopped,bkptno="1",reason="breakpoint-hit",disp="keep", frame={addr="0x00007ffff7ae00ed",func="__cxa_throw", args=[],from="/lib64/libstdc++.so.6",arch="i386:x86-64"}, thread-id="1",stopped-threads="all",core="6" (gdb) The `-catch-rethrow' Command ---------------------------- Synopsis ........ -catch-rethrow [ -t ] [ -r REGEXP] Stop when a C++ exception is re-thrown. If REGEXP is given, then only exceptions whose type matches the regular expression will be caught. If `-t' is given, then the catchpoint is enabled only for one stop, the catchpoint is automatically deleted after the first event is caught. GDB Command ........... The corresponding GDB commands are `catch rethrow' and `tcatch rethrow' (*note Set Catchpoints::). Example ....... -catch-rethrow -r exception_type ^done,bkpt={number="1",type="catchpoint",disp="keep",enabled="y", what="exception rethrow",catch-type="rethrow", thread-groups=["i1"], regexp="exception_type",times="0"} (gdb) -exec-run ^running (gdb) ~"\n" ~"Catchpoint 1 (exception rethrown), 0x00007ffff7ae00ed in __cxa_rethrow () from /lib64/libstdc++.so.6\n" *stopped,bkptno="1",reason="breakpoint-hit",disp="keep", frame={addr="0x00007ffff7ae00ed",func="__cxa_rethrow", args=[],from="/lib64/libstdc++.so.6",arch="i386:x86-64"}, thread-id="1",stopped-threads="all",core="6" (gdb) The `-catch-catch' Command -------------------------- Synopsis ........ -catch-catch [ -t ] [ -r REGEXP] Stop when the debuggee catches a C++ exception. If REGEXP is given, then only exceptions whose type matches the regular expression will be caught. If `-t' is given, then the catchpoint is enabled only for one stop, the catchpoint is automatically deleted after the first event is caught. GDB Command ........... The corresponding GDB commands are `catch catch' and `tcatch catch' (*note Set Catchpoints::). Example ....... -catch-catch -r exception_type ^done,bkpt={number="1",type="catchpoint",disp="keep",enabled="y", what="exception catch",catch-type="catch", thread-groups=["i1"], regexp="exception_type",times="0"} (gdb) -exec-run ^running (gdb) ~"\n" ~"Catchpoint 1 (exception caught), 0x00007ffff7ae00ed in __cxa_begin_catch () from /lib64/libstdc++.so.6\n" *stopped,bkptno="1",reason="breakpoint-hit",disp="keep", frame={addr="0x00007ffff7ae00ed",func="__cxa_begin_catch", args=[],from="/lib64/libstdc++.so.6",arch="i386:x86-64"}, thread-id="1",stopped-threads="all",core="6" (gdb)  File: gdb.info, Node: GDB/MI Program Context, Next: GDB/MI Thread Commands, Prev: GDB/MI Catchpoint Commands, Up: GDB/MI 27.10 GDB/MI Program Context ============================= The `-exec-arguments' Command ----------------------------- Synopsis ........ -exec-arguments ARGS Set the inferior program arguments, to be used in the next `-exec-run'. GDB Command ........... The corresponding GDB command is `set args'. Example ....... (gdb) -exec-arguments -v word ^done (gdb) The `-environment-cd' Command ----------------------------- Synopsis ........ -environment-cd PATHDIR Set GDB's working directory. GDB Command ........... The corresponding GDB command is `cd'. Example ....... (gdb) -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb ^done (gdb) The `-environment-directory' Command ------------------------------------ Synopsis ........ -environment-directory [ -r ] [ PATHDIR ]+ Add directories PATHDIR to beginning of search path for source files. If the `-r' option is used, the search path is reset to the default search path. If directories PATHDIR are supplied in addition to the `-r' option, the search path is first reset and then addition occurs as normal. Multiple directories may be specified, separated by blanks. Specifying multiple directories in a single command results in the directories added to the beginning of the search path in the same order they were presented in the command. If blanks are needed as part of a directory name, double-quotes should be used around the name. In the command output, the path will show up separated by the system directory-separator character. The directory-separator character must not be used in any directory name. If no directories are specified, the current search path is displayed. GDB Command ........... The corresponding GDB command is `dir'. Example ....... (gdb) -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" (gdb) -environment-directory "" ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" (gdb) -environment-directory -r /home/jjohnstn/src/gdb /usr/src ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" (gdb) -environment-directory -r ^done,source-path="$cdir:$cwd" (gdb) The `-environment-path' Command ------------------------------- Synopsis ........ -environment-path [ -r ] [ PATHDIR ]+ Add directories PATHDIR to beginning of search path for object files. If the `-r' option is used, the search path is reset to the original search path that existed at gdb start-up. If directories PATHDIR are supplied in addition to the `-r' option, the search path is first reset and then addition occurs as normal. Multiple directories may be specified, separated by blanks. Specifying multiple directories in a single command results in the directories added to the beginning of the search path in the same order they were presented in the command. If blanks are needed as part of a directory name, double-quotes should be used around the name. In the command output, the path will show up separated by the system directory-separator character. The directory-separator character must not be used in any directory name. If no directories are specified, the current path is displayed. GDB Command ........... The corresponding GDB command is `path'. Example ....... (gdb) -environment-path ^done,path="/usr/bin" (gdb) -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" (gdb) -environment-path -r /usr/local/bin ^done,path="/usr/local/bin:/usr/bin" (gdb) The `-environment-pwd' Command ------------------------------ Synopsis ........ -environment-pwd Show the current working directory. GDB Command ........... The corresponding GDB command is `pwd'. Example ....... (gdb) -environment-pwd ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" (gdb)  File: gdb.info, Node: GDB/MI Thread Commands, Next: GDB/MI Ada Tasking Commands, Prev: GDB/MI Program Context, Up: GDB/MI 27.11 GDB/MI Thread Commands ============================ The `-thread-info' Command -------------------------- Synopsis ........ -thread-info [ THREAD-ID ] Reports information about either a specific thread, if the THREAD-ID parameter is present, or about all threads. THREAD-ID is the thread's global thread ID. When printing information about all threads, also reports the global ID of the current thread. GDB Command ........... The `info thread' command prints the same information about all threads. Result ...... The result contains the following attributes: `threads' A list of threads. The format of the elements of the list is described in *Note GDB/MI Thread Information::. `current-thread-id' The global id of the currently selected thread. This field is omitted if there is no selected thread (for example, when the selected inferior is not running, and therefore has no threads) or if a THREAD-ID argument was passed to the command. Example ....... -thread-info ^done,threads=[ {id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", frame={level="0",addr="0xffffe410",func="__kernel_vsyscall", args=[]},state="running"}, {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", frame={level="0",addr="0x0804891f",func="foo", args=[{name="i",value="10"}], file="/tmp/a.c",fullname="/tmp/a.c",line="158",arch="i386:x86_64"}, state="running"}], current-thread-id="1" (gdb) The `-thread-list-ids' Command ------------------------------ Synopsis ........ -thread-list-ids Produces a list of the currently known global GDB thread ids. At the end of the list it also prints the total number of such threads. This command is retained for historical reasons, the `-thread-info' command should be used instead. GDB Command ........... Part of `info threads' supplies the same information. Example ....... (gdb) -thread-list-ids ^done,thread-ids={thread-id="3",thread-id="2",thread-id="1"}, current-thread-id="1",number-of-threads="3" (gdb) The `-thread-select' Command ---------------------------- Synopsis ........ -thread-select THREAD-ID Make thread with global thread number THREAD-ID the current thread. It prints the number of the new current thread, and the topmost frame for that thread. This command is deprecated in favor of explicitly using the `--thread' option to each command. GDB Command ........... The corresponding GDB command is `thread'. Example ....... (gdb) -exec-next ^running (gdb) *stopped,reason="end-stepping-range",thread-id="2",line="187", file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c" (gdb) -thread-list-ids ^done, thread-ids={thread-id="3",thread-id="2",thread-id="1"}, number-of-threads="3" (gdb) -thread-select 3 ^done,new-thread-id="3", frame={level="0",func="vprintf", args=[{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""}, {name="arg",value="0x2"}],file="vprintf.c",line="31",arch="i386:x86_64"} (gdb)  File: gdb.info, Node: GDB/MI Ada Tasking Commands, Next: GDB/MI Program Execution, Prev: GDB/MI Thread Commands, Up: GDB/MI 27.12 GDB/MI Ada Tasking Commands ================================= The `-ada-task-info' Command ---------------------------- Synopsis ........ -ada-task-info [ TASK-ID ] Reports information about either a specific Ada task, if the TASK-ID parameter is present, or about all Ada tasks. GDB Command ........... The `info tasks' command prints the same information about all Ada tasks (*note Ada Tasks::). Result ...... The result is a table of Ada tasks. The following columns are defined for each Ada task: `current' This field exists only for the current thread. It has the value `*'. `id' The identifier that GDB uses to refer to the Ada task. `task-id' The identifier that the target uses to refer to the Ada task. `thread-id' The global thread identifier of the thread corresponding to the Ada task. This field should always exist, as Ada tasks are always implemented on top of a thread. But if GDB cannot find this corresponding thread for any reason, the field is omitted. `parent-id' This field exists only when the task was created by another task. In this case, it provides the ID of the parent task. `priority' The base priority of the task. `state' The current state of the task. For a detailed description of the possible states, see *Note Ada Tasks::. `name' The name of the task. Example ....... -ada-task-info ^done,tasks={nr_rows="3",nr_cols="8", hdr=[{width="1",alignment="-1",col_name="current",colhdr=""}, {width="3",alignment="1",col_name="id",colhdr="ID"}, {width="9",alignment="1",col_name="task-id",colhdr="TID"}, {width="4",alignment="1",col_name="thread-id",colhdr=""}, {width="4",alignment="1",col_name="parent-id",colhdr="P-ID"}, {width="3",alignment="1",col_name="priority",colhdr="Pri"}, {width="22",alignment="-1",col_name="state",colhdr="State"}, {width="1",alignment="2",col_name="name",colhdr="Name"}], body=[{current="*",id="1",task-id=" 644010",thread-id="1",priority="48", state="Child Termination Wait",name="main_task"}]} (gdb)  File: gdb.info, Node: GDB/MI Program Execution, Next: GDB/MI Stack Manipulation, Prev: GDB/MI Ada Tasking Commands, Up: GDB/MI 27.13 GDB/MI Program Execution ============================== These are the asynchronous commands which generate the out-of-band record `*stopped'. Currently GDB only really executes asynchronously with remote targets and this interaction is mimicked in other cases. The `-exec-continue' Command ---------------------------- Synopsis ........ -exec-continue [--reverse] [--all|--thread-group N] Resumes the execution of the inferior program, which will continue to execute until it reaches a debugger stop event. If the `--reverse' option is specified, execution resumes in reverse until it reaches a stop event. Stop events may include * breakpoints, watchpoints, tracepoints, or catchpoints * signals or exceptions * the end of the process (or its beginning under `--reverse') * the end or beginning of a replay log if one is being used. In all-stop mode (*note All-Stop Mode::), may resume only one thread, or all threads, depending on the value of the `scheduler-locking' variable. If `--all' is specified, all threads (in all inferiors) will be resumed. The `--all' option is ignored in all-stop mode. If the `--thread-group' options is specified, then all threads in that thread group are resumed. GDB Command ........... The corresponding GDB corresponding is `continue'. Example ....... -exec-continue ^running (gdb) @@Hello world *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",frame={ func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c", line="13",arch="i386:x86_64"} (gdb) For a `breakpoint-hit' stopped reason, when the breakpoint encountered has multiple locations, the field `bkptno' is followed by the field `locno'. -exec-continue ^running (gdb) @@Hello world *stopped,reason="breakpoint-hit",disp="keep",bkptno="2",locno="3",frame={ func="foo",args=[],file="hello.c",fullname="/home/foo/bar/hello.c", line="13",arch="i386:x86_64"} (gdb) The `-exec-finish' Command -------------------------- Synopsis ........ -exec-finish [--reverse] Resumes the execution of the inferior program until the current function is exited. Displays the results returned by the function. If the `--reverse' option is specified, resumes the reverse execution of the inferior program until the point where current function was called. GDB Command ........... The corresponding GDB command is `finish'. Example ....... Function returning `void'. -exec-finish ^running (gdb) @@hello from foo *stopped,reason="function-finished",frame={func="main",args=[], file="hello.c",fullname="/home/foo/bar/hello.c",line="7",arch="i386:x86_64"} (gdb) Function returning other than `void'. The name of the internal GDB variable storing the result is printed, together with the value itself. -exec-finish ^running (gdb) *stopped,reason="function-finished",frame={addr="0x000107b0",func="foo", args=[{name="a",value="1"],{name="b",value="9"}}, file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, gdb-result-var="$1",return-value="0" (gdb) The `-exec-interrupt' Command ----------------------------- Synopsis ........ -exec-interrupt [--all|--thread-group N] Interrupts the background execution of the target. Note how the token associated with the stop message is the one for the execution command that has been interrupted. The token for the interrupt itself only appears in the `^done' output. If the user is trying to interrupt a non-running program, an error message will be printed. Note that when asynchronous execution is enabled, this command is asynchronous just like other execution commands. That is, first the `^done' response will be printed, and the target stop will be reported after that using the `*stopped' notification. In non-stop mode, only the context thread is interrupted by default. All threads (in all inferiors) will be interrupted if the `--all' option is specified. If the `--thread-group' option is specified, all threads in that group will be interrupted. GDB Command ........... The corresponding GDB command is `interrupt'. Example ....... (gdb) 111-exec-continue 111^running (gdb) 222-exec-interrupt 222^done (gdb) 111*stopped,signal-name="SIGINT",signal-meaning="Interrupt", frame={addr="0x00010140",func="foo",args=[],file="try.c", fullname="/home/foo/bar/try.c",line="13",arch="i386:x86_64"} (gdb) (gdb) -exec-interrupt ^error,msg="mi_cmd_exec_interrupt: Inferior not executing." (gdb) The `-exec-jump' Command ------------------------ Synopsis ........ -exec-jump LOCSPEC Resumes execution of the inferior program at the address to which LOCSPEC resolves. *Note Location Specifications::, for a description of the different forms of LOCSPEC. GDB Command ........... The corresponding GDB command is `jump'. Example ....... -exec-jump foo.c:10 *running,thread-id="all" ^running The `-exec-next' Command ------------------------ Synopsis ........ -exec-next [--reverse] Resumes execution of the inferior program, stopping when the beginning of the next source line is reached. If the `--reverse' option is specified, resumes reverse execution of the inferior program, stopping at the beginning of the previous source line. If you issue this command on the first line of a function, it will take you back to the caller of that function, to the source line where the function was called. GDB Command ........... The corresponding GDB command is `next'. Example ....... -exec-next ^running (gdb) *stopped,reason="end-stepping-range",line="8",file="hello.c" (gdb) The `-exec-next-instruction' Command ------------------------------------ Synopsis ........ -exec-next-instruction [--reverse] Executes one machine instruction. If the instruction is a function call, continues until the function returns. If the program stops at an instruction in the middle of a source line, the address will be printed as well. If the `--reverse' option is specified, resumes reverse execution of the inferior program, stopping at the previous instruction. If the previously executed instruction was a return from another function, it will continue to execute in reverse until the call to that function (from the current stack frame) is reached. GDB Command ........... The corresponding GDB command is `nexti'. Example ....... (gdb) -exec-next-instruction ^running (gdb) *stopped,reason="end-stepping-range", addr="0x000100d4",line="5",file="hello.c" (gdb) The `-exec-return' Command -------------------------- Synopsis ........ -exec-return Makes current function return immediately. Doesn't execute the inferior. Displays the new current frame. GDB Command ........... The corresponding GDB command is `return'. Example ....... (gdb) 200-break-insert callee4 200^done,bkpt={number="1",addr="0x00010734", file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"} (gdb) 000-exec-run 000^running (gdb) 000*stopped,reason="breakpoint-hit",disp="keep",bkptno="1", frame={func="callee4",args=[], file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8", arch="i386:x86_64"} (gdb) 205-break-delete 205^done (gdb) 111-exec-return 111^done,frame={level="0",func="callee3", args=[{name="strarg", value="0x11940 \"A string argument.\""}], file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18", arch="i386:x86_64"} (gdb) The `-exec-run' Command ----------------------- Synopsis ........ -exec-run [ --all | --thread-group N ] [ --start ] Starts execution of the inferior from the beginning. The inferior executes until either a breakpoint is encountered or the program exits. In the latter case the output will include an exit code, if the program has exited exceptionally. When neither the `--all' nor the `--thread-group' option is specified, the current inferior is started. If the `--thread-group' option is specified, it should refer to a thread group of type `process', and that thread group will be started. If the `--all' option is specified, then all inferiors will be started. Using the `--start' option instructs the debugger to stop the execution at the start of the inferior's main subprogram, following the same behavior as the `start' command (*note Starting::). GDB Command ........... The corresponding GDB command is `run'. Examples ........ (gdb) -break-insert main ^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",line="4"} (gdb) -exec-run ^running (gdb) *stopped,reason="breakpoint-hit",disp="keep",bkptno="1", frame={func="main",args=[],file="recursive2.c", fullname="/home/foo/bar/recursive2.c",line="4",arch="i386:x86_64"} (gdb) Program exited normally: (gdb) -exec-run ^running (gdb) x = 55 *stopped,reason="exited-normally" (gdb) Program exited exceptionally: (gdb) -exec-run ^running (gdb) x = 55 *stopped,reason="exited",exit-code="01" (gdb) Another way the program can terminate is if it receives a signal such as `SIGINT'. In this case, GDB/MI displays this: (gdb) *stopped,reason="exited-signalled",signal-name="SIGINT", signal-meaning="Interrupt" The `-exec-step' Command ------------------------ Synopsis ........ -exec-step [--reverse] Resumes execution of the inferior program, stopping when the beginning of the next source line is reached, if the next source line is not a function call. If it is, stop at the first instruction of the called function. If the `--reverse' option is specified, resumes reverse execution of the inferior program, stopping at the beginning of the previously executed source line. GDB Command ........... The corresponding GDB command is `step'. Example ....... Stepping into a function: -exec-step ^running (gdb) *stopped,reason="end-stepping-range", frame={func="foo",args=[{name="a",value="10"}, {name="b",value="0"}],file="recursive2.c", fullname="/home/foo/bar/recursive2.c",line="11",arch="i386:x86_64"} (gdb) Regular stepping: -exec-step ^running (gdb) *stopped,reason="end-stepping-range",line="14",file="recursive2.c" (gdb) The `-exec-step-instruction' Command ------------------------------------ Synopsis ........ -exec-step-instruction [--reverse] Resumes the inferior which executes one machine instruction. If the `--reverse' option is specified, resumes reverse execution of the inferior program, stopping at the previously executed instruction. The output, once GDB has stopped, will vary depending on whether we have stopped in the middle of a source line or not. In the former case, the address at which the program stopped will be printed as well. GDB Command ........... The corresponding GDB command is `stepi'. Example ....... (gdb) -exec-step-instruction ^running (gdb) *stopped,reason="end-stepping-range", frame={func="foo",args=[],file="try.c", fullname="/home/foo/bar/try.c",line="10",arch="i386:x86_64"} (gdb) -exec-step-instruction ^running (gdb) *stopped,reason="end-stepping-range", frame={addr="0x000100f4",func="foo",args=[],file="try.c", fullname="/home/foo/bar/try.c",line="10",arch="i386:x86_64"} (gdb) The `-exec-until' Command ------------------------- Synopsis ........ -exec-until [ LOCSPEC ] Executes the inferior until it reaches the address to which LOCSPEC resolves. If there is no argument, the inferior executes until it reaches a source line greater than the current one. The reason for stopping in this case will be `location-reached'. GDB Command ........... The corresponding GDB command is `until'. Example ....... (gdb) -exec-until recursive2.c:6 ^running (gdb) x = 55 *stopped,reason="location-reached",frame={func="main",args=[], file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6", arch="i386:x86_64"} (gdb)  File: gdb.info, Node: GDB/MI Stack Manipulation, Next: GDB/MI Variable Objects, Prev: GDB/MI Program Execution, Up: GDB/MI 27.14 GDB/MI Stack Manipulation Commands ======================================== The `-enable-frame-filters' Command ----------------------------------- -enable-frame-filters GDB allows Python-based frame filters to affect the output of the MI commands relating to stack traces. As there is no way to implement this in a fully backward-compatible way, a front end must request that this functionality be enabled. Once enabled, this feature cannot be disabled. Note that if Python support has not been compiled into GDB, this command will still succeed (and do nothing). The `-stack-info-frame' Command ------------------------------- Synopsis ........ -stack-info-frame Get info on the selected frame. GDB Command ........... The corresponding GDB command is `info frame' or `frame' (without arguments). Example ....... (gdb) -stack-info-frame ^done,frame={level="1",addr="0x0001076c",func="callee3", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17", arch="i386:x86_64"} (gdb) The `-stack-info-depth' Command ------------------------------- Synopsis ........ -stack-info-depth [ MAX-DEPTH ] Return the depth of the stack. If the integer argument MAX-DEPTH is specified, do not count beyond MAX-DEPTH frames. GDB Command ........... There's no equivalent GDB command. Example ....... For a stack with frame levels 0 through 11: (gdb) -stack-info-depth ^done,depth="12" (gdb) -stack-info-depth 4 ^done,depth="4" (gdb) -stack-info-depth 12 ^done,depth="12" (gdb) -stack-info-depth 11 ^done,depth="11" (gdb) -stack-info-depth 13 ^done,depth="12" (gdb) The `-stack-list-arguments' Command ----------------------------------- Synopsis ........ -stack-list-arguments [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES [ LOW-FRAME HIGH-FRAME ] Display a list of the arguments for the frames between LOW-FRAME and HIGH-FRAME (inclusive). If LOW-FRAME and HIGH-FRAME are not provided, list the arguments for the whole call stack. If the two arguments are equal, show the single frame at the corresponding level. It is an error if LOW-FRAME is larger than the actual number of frames. On the other hand, HIGH-FRAME may be larger than the actual number of frames, in which case only existing frames will be returned. If PRINT-VALUES is 0 or `--no-values', print only the names of the variables; if it is 1 or `--all-values', print also their values; and if it is 2 or `--simple-values', print the name, type and value for simple data types, and the name and type for arrays, structures and unions. If the option `--no-frame-filters' is supplied, then Python frame filters will not be executed. If the `--skip-unavailable' option is specified, arguments that are not available are not listed. Partially available arguments are still displayed, however. Use of this command to obtain arguments in a single frame is deprecated in favor of the `-stack-list-variables' command. GDB Command ........... GDB does not have an equivalent command. `gdbtk' has a `gdb_get_args' command which partially overlaps with the functionality of `-stack-list-arguments'. Example ....... (gdb) -stack-list-frames ^done, stack=[ frame={level="0",addr="0x00010734",func="callee4", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8", arch="i386:x86_64"}, frame={level="1",addr="0x0001076c",func="callee3", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17", arch="i386:x86_64"}, frame={level="2",addr="0x0001078c",func="callee2", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22", arch="i386:x86_64"}, frame={level="3",addr="0x000107b4",func="callee1", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27", arch="i386:x86_64"}, frame={level="4",addr="0x000107e0",func="main", file="../../../devo/gdb/testsuite/gdb.mi/basics.c", fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32", arch="i386:x86_64"}] (gdb) -stack-list-arguments 0 ^done, stack-args=[ frame={level="0",args=[]}, frame={level="1",args=[name="strarg"]}, frame={level="2",args=[name="intarg",name="strarg"]}, frame={level="3",args=[name="intarg",name="strarg",name="fltarg"]}, frame={level="4",args=[]}] (gdb) -stack-list-arguments 1 ^done, stack-args=[ frame={level="0",args=[]}, frame={level="1", args=[{name="strarg",value="0x11940 \"A string argument.\""}]}, frame={level="2",args=[ {name="intarg",value="2"}, {name="strarg",value="0x11940 \"A string argument.\""}]}, {frame={level="3",args=[ {name="intarg",value="2"}, {name="strarg",value="0x11940 \"A string argument.\""}, {name="fltarg",value="3.5"}]}, frame={level="4",args=[]}] (gdb) -stack-list-arguments 0 2 2 ^done,stack-args=[frame={level="2",args=[name="intarg",name="strarg"]}] (gdb) -stack-list-arguments 1 2 2 ^done,stack-args=[frame={level="2", args=[{name="intarg",value="2"}, {name="strarg",value="0x11940 \"A string argument.\""}]}] (gdb) The `-stack-list-frames' Command -------------------------------- Synopsis ........ -stack-list-frames [ --no-frame-filters LOW-FRAME HIGH-FRAME ] List the frames currently on the stack. For each frame it displays the following info: `LEVEL' The frame number, 0 being the topmost frame, i.e., the innermost function. `ADDR' The `$pc' value for that frame. `FUNC' Function name. `FILE' File name of the source file where the function lives. `FULLNAME' The full file name of the source file where the function lives. `LINE' Line number corresponding to the `$pc'. `FROM' The shared library where this function is defined. This is only given if the frame's function is not known. `ARCH' Frame's architecture. If invoked without arguments, this command prints a backtrace for the whole stack. If given two integer arguments, it shows the frames whose levels are between the two arguments (inclusive). If the two arguments are equal, it shows the single frame at the corresponding level. It is an error if LOW-FRAME is larger than the actual number of frames. On the other hand, HIGH-FRAME may be larger than the actual number of frames, in which case only existing frames will be returned. If the option `--no-frame-filters' is supplied, then Python frame filters will not be executed. GDB Command ........... The corresponding GDB commands are `backtrace' and `where'. Example ....... Full stack backtrace: (gdb) -stack-list-frames ^done,stack= [frame={level="0",addr="0x0001076c",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11", arch="i386:x86_64"}, frame={level="1",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="2",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="3",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="4",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="5",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="6",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="7",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="8",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="9",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="10",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="11",addr="0x00010738",func="main", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4", arch="i386:x86_64"}] (gdb) Show frames between LOW_FRAME and HIGH_FRAME: (gdb) -stack-list-frames 3 5 ^done,stack= [frame={level="3",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="4",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}, frame={level="5",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}] (gdb) Show a single frame: (gdb) -stack-list-frames 3 3 ^done,stack= [frame={level="3",addr="0x000107a4",func="foo", file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14", arch="i386:x86_64"}] (gdb) The `-stack-list-locals' Command -------------------------------- Synopsis ........ -stack-list-locals [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES Display the local variable names for the selected frame. If PRINT-VALUES is 0 or `--no-values', print only the names of the variables; if it is 1 or `--all-values', print also their values; and if it is 2 or `--simple-values', print the name, type and value for simple data types, and the name and type for arrays, structures and unions. In this last case, a frontend can immediately display the value of simple data types and create variable objects for other data types when the user wishes to explore their values in more detail. If the option `--no-frame-filters' is supplied, then Python frame filters will not be executed. If the `--skip-unavailable' option is specified, local variables that are not available are not listed. Partially available local variables are still displayed, however. This command is deprecated in favor of the `-stack-list-variables' command. GDB Command ........... `info locals' in GDB, `gdb_get_locals' in `gdbtk'. Example ....... (gdb) -stack-list-locals 0 ^done,locals=[name="A",name="B",name="C"] (gdb) -stack-list-locals --all-values ^done,locals=[{name="A",value="1"},{name="B",value="2"}, {name="C",value="{1, 2, 3}"}] -stack-list-locals --simple-values ^done,locals=[{name="A",type="int",value="1"}, {name="B",type="int",value="2"},{name="C",type="int [3]"}] (gdb) The `-stack-list-variables' Command ----------------------------------- Synopsis ........ -stack-list-variables [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES Display the names of local variables and function arguments for the selected frame. If PRINT-VALUES is 0 or `--no-values', print only the names of the variables; if it is 1 or `--all-values', print also their values; and if it is 2 or `--simple-values', print the name, type and value for simple data types, and the name and type for arrays, structures and unions. If the option `--no-frame-filters' is supplied, then Python frame filters will not be executed. If the `--skip-unavailable' option is specified, local variables and arguments that are not available are not listed. Partially available arguments and local variables are still displayed, however. Example ....... (gdb) -stack-list-variables --thread 1 --frame 0 --all-values ^done,variables=[{name="x",value="11"},{name="s",value="{a = 1, b = 2}"}] (gdb) The `-stack-select-frame' Command --------------------------------- Synopsis ........ -stack-select-frame FRAMENUM Change the selected frame. Select a different frame FRAMENUM on the stack. This command in deprecated in favor of passing the `--frame' option to every command. GDB Command ........... The corresponding GDB commands are `frame', `up', `down', `select-frame', `up-silent', and `down-silent'. Example ....... (gdb) -stack-select-frame 2 ^done (gdb)  File: gdb.info, Node: GDB/MI Variable Objects, Next: GDB/MI Data Manipulation, Prev: GDB/MI Stack Manipulation, Up: GDB/MI 27.15 GDB/MI Variable Objects ============================= Introduction to Variable Objects -------------------------------- Variable objects are "object-oriented" MI interface for examining and changing values of expressions. Unlike some other MI interfaces that work with expressions, variable objects are specifically designed for simple and efficient presentation in the frontend. A variable object is identified by string name. When a variable object is created, the frontend specifies the expression for that variable object. The expression can be a simple variable, or it can be an arbitrary complex expression, and can even involve CPU registers. After creating a variable object, the frontend can invoke other variable object operations--for example to obtain or change the value of a variable object, or to change display format. Variable objects have hierarchical tree structure. Any variable object that corresponds to a composite type, such as structure in C, has a number of child variable objects, for example corresponding to each element of a structure. A child variable object can itself have children, recursively. Recursion ends when we reach leaf variable objects, which always have built-in types. Child variable objects are created only by explicit request, so if a frontend is not interested in the children of a particular variable object, no child will be created. For a leaf variable object it is possible to obtain its value as a string, or set the value from a string. String value can be also obtained for a non-leaf variable object, but it's generally a string that only indicates the type of the object, and does not list its contents. Assignment to a non-leaf variable object is not allowed. A frontend does not need to read the values of all variable objects each time the program stops. Instead, MI provides an update command that lists all variable objects whose values has changed since the last update operation. This considerably reduces the amount of data that must be transferred to the frontend. As noted above, children variable objects are created on demand, and only leaf variable objects have a real value. As result, gdb will read target memory only for leaf variables that frontend has created. The automatic update is not always desirable. For example, a frontend might want to keep a value of some expression for future reference, and never update it. For another example, fetching memory is relatively slow for embedded targets, so a frontend might want to disable automatic update for the variables that are either not visible on the screen, or "closed". This is possible using so called "frozen variable objects". Such variable objects are never implicitly updated. Variable objects can be either "fixed" or "floating". For the fixed variable object, the expression is parsed when the variable object is created, including associating identifiers to specific variables. The meaning of expression never changes. For a floating variable object the values of variables whose names appear in the expressions are re-evaluated every time in the context of the current frame. Consider this example: void do_work(...) { struct work_state state; if (...) do_work(...); } If a fixed variable object for the `state' variable is created in this function, and we enter the recursive call, the variable object will report the value of `state' in the top-level `do_work' invocation. On the other hand, a floating variable object will report the value of `state' in the current frame. If an expression specified when creating a fixed variable object refers to a local variable, the variable object becomes bound to the thread and frame in which the variable object is created. When such variable object is updated, GDB makes sure that the thread/frame combination the variable object is bound to still exists, and re-evaluates the variable object in context of that thread/frame. The following is the complete set of GDB/MI operations defined to access this functionality: *Operation* *Description* `-enable-pretty-printing' enable Python-based pretty-printing `-var-create' create a variable object `-var-delete' delete the variable object and/or its children `-var-set-format' set the display format of this variable `-var-show-format' show the display format of this variable `-var-info-num-children' tells how many children this object has `-var-list-children' return a list of the object's children `-var-info-type' show the type of this variable object `-var-info-expression' print parent-relative expression that this variable object represents `-var-info-path-expression' print full expression that this variable object represents `-var-show-attributes' is this variable editable? does it exist here? `-var-evaluate-expression' get the value of this variable `-var-assign' set the value of this variable `-var-update' update the variable and its children `-var-set-frozen' set frozenness attribute `-var-set-update-range' set range of children to display on update In the next subsection we describe each operation in detail and suggest how it can be used. Description And Use of Operations on Variable Objects ----------------------------------------------------- The `-enable-pretty-printing' Command ------------------------------------- -enable-pretty-printing GDB allows Python-based visualizers to affect the output of the MI variable object commands. However, because there was no way to implement this in a fully backward-compatible way, a front end must request that this functionality be enabled. Once enabled, this feature cannot be disabled. Note that if Python support has not been compiled into GDB, this command will still succeed (and do nothing). The `-var-create' Command ------------------------- Synopsis ........ -var-create {NAME | "-"} {FRAME-ADDR | "*" | "@@"} EXPRESSION This operation creates a variable object, which allows the monitoring of a variable, the result of an expression, a memory cell or a CPU register. The NAME parameter is the string by which the object can be referenced. It must be unique. If `-' is specified, the varobj system will generate a string "varNNNNNN" automatically. It will be unique provided that one does not specify NAME of that format. The command fails if a duplicate name is found. The frame under which the expression should be evaluated can be specified by FRAME-ADDR. A `*' indicates that the current frame should be used. A `@@' indicates that a floating variable object must be created. EXPRESSION is any expression valid on the current language set (must not begin with a `*'), or one of the following: * `*ADDR', where ADDR is the address of a memory cell * `*ADDR-ADDR' -- a memory address range (TBD) * `$REGNAME' -- a CPU register name A varobj's contents may be provided by a Python-based pretty-printer. In this case the varobj is known as a "dynamic varobj". Dynamic varobjs have slightly different semantics in some cases. If the `-enable-pretty-printing' command is not sent, then GDB will never create a dynamic varobj. This ensures backward compatibility for existing clients. Result ...... This operation returns attributes of the newly-created varobj. These are: `name' The name of the varobj. `numchild' The number of children of the varobj. This number is not necessarily reliable for a dynamic varobj. Instead, you must examine the `has_more' attribute. `value' The varobj's scalar value. For a varobj whose type is some sort of aggregate (e.g., a `struct'), this value will not be interesting. For a dynamic varobj, this value comes directly from the Python pretty-printer object's `to_string' method. `type' The varobj's type. This is a string representation of the type, as would be printed by the GDB CLI. If `print object' (*note set print object: Print Settings.) is set to `on', the _actual_ (derived) type of the object is shown rather than the _declared_ one. `thread-id' If a variable object is bound to a specific thread, then this is the thread's global identifier. `has_more' For a dynamic varobj, this indicates whether there appear to be any children available. For a non-dynamic varobj, this will be 0. `dynamic' This attribute will be present and have the value `1' if the varobj is a dynamic varobj. If the varobj is not a dynamic varobj, then this attribute will not be present. `displayhint' A dynamic varobj can supply a display hint to the front end. The value comes directly from the Python pretty-printer object's `display_hint' method. *Note Pretty Printing API::. Typical output will look like this: name="NAME",numchild="N",type="TYPE",thread-id="M", has_more="HAS_MORE" The `-var-delete' Command ------------------------- Synopsis ........ -var-delete [ -c ] NAME Deletes a previously created variable object and all of its children. With the `-c' option, just deletes the children. Returns an error if the object NAME is not found. The `-var-set-format' Command ----------------------------- Synopsis ........ -var-set-format NAME FORMAT-SPEC Sets the output format for the value of the object NAME to be FORMAT-SPEC. The syntax for the FORMAT-SPEC is as follows: FORMAT-SPEC ==> {binary | decimal | hexadecimal | octal | natural | zero-hexadecimal} The natural format is the default format chosen automatically based on the variable type (like decimal for an `int', hex for pointers, etc.). The zero-hexadecimal format has a representation similar to hexadecimal but with padding zeroes to the left of the value. For example, a 32-bit hexadecimal value of 0x1234 would be represented as 0x00001234 in the zero-hexadecimal format. For a variable with children, the format is set only on the variable itself, and the children are not affected. The `-var-show-format' Command ------------------------------ Synopsis ........ -var-show-format NAME Returns the format used to display the value of the object NAME. FORMAT ==> FORMAT-SPEC The `-var-info-num-children' Command ------------------------------------ Synopsis ........ -var-info-num-children NAME Returns the number of children of a variable object NAME: numchild=N Note that this number is not completely reliable for a dynamic varobj. It will return the current number of children, but more children may be available. The `-var-list-children' Command -------------------------------- Synopsis ........ -var-list-children [PRINT-VALUES] NAME [FROM TO] Return a list of the children of the specified variable object and create variable objects for them, if they do not already exist. With a single argument or if PRINT-VALUES has a value of 0 or `--no-values', print only the names of the variables; if PRINT-VALUES is 1 or `--all-values', also print their values; and if it is 2 or `--simple-values' print the name and value for simple data types and just the name for arrays, structures and unions. FROM and TO, if specified, indicate the range of children to report. If FROM or TO is less than zero, the range is reset and all children will be reported. Otherwise, children starting at FROM (zero-based) and up to and excluding TO will be reported. If a child range is requested, it will only affect the current call to `-var-list-children', but not future calls to `-var-update'. For this, you must instead use `-var-set-update-range'. The intent of this approach is to enable a front end to implement any update approach it likes; for example, scrolling a view may cause the front end to request more children with `-var-list-children', and then the front end could call `-var-set-update-range' with a different range to ensure that future updates are restricted to just the visible items. For each child the following results are returned: NAME Name of the variable object created for this child. EXP The expression to be shown to the user by the front end to designate this child. For example this may be the name of a structure member. For a dynamic varobj, this value cannot be used to form an expression. There is no way to do this at all with a dynamic varobj. For C/C++ structures there are several pseudo children returned to designate access qualifiers. For these pseudo children EXP is `public', `private', or `protected'. In this case the type and value are not present. A dynamic varobj will not report the access qualifying pseudo-children, regardless of the language. This information is not available at all with a dynamic varobj. NUMCHILD Number of children this child has. For a dynamic varobj, this will be 0. TYPE The type of the child. If `print object' (*note set print object: Print Settings.) is set to `on', the _actual_ (derived) type of the object is shown rather than the _declared_ one. VALUE If values were requested, this is the value. THREAD-ID If this variable object is associated with a thread, this is the thread's global thread id. Otherwise this result is not present. FROZEN If the variable object is frozen, this variable will be present with a value of 1. DISPLAYHINT A dynamic varobj can supply a display hint to the front end. The value comes directly from the Python pretty-printer object's `display_hint' method. *Note Pretty Printing API::. DYNAMIC This attribute will be present and have the value `1' if the varobj is a dynamic varobj. If the varobj is not a dynamic varobj, then this attribute will not be present. The result may have its own attributes: `displayhint' A dynamic varobj can supply a display hint to the front end. The value comes directly from the Python pretty-printer object's `display_hint' method. *Note Pretty Printing API::. `has_more' This is an integer attribute which is nonzero if there are children remaining after the end of the selected range. Example ....... (gdb) -var-list-children n ^done,numchild=N,children=[child={name=NAME,exp=EXP, numchild=N,type=TYPE},(repeats N times)] (gdb) -var-list-children --all-values n ^done,numchild=N,children=[child={name=NAME,exp=EXP, numchild=N,value=VALUE,type=TYPE},(repeats N times)] The `-var-info-type' Command ---------------------------- Synopsis ........ -var-info-type NAME Returns the type of the specified variable NAME. The type is returned as a string in the same format as it is output by the GDB CLI: type=TYPENAME The `-var-info-expression' Command ---------------------------------- Synopsis ........ -var-info-expression NAME Returns a string that is suitable for presenting this variable object in user interface. The string is generally not valid expression in the current language, and cannot be evaluated. For example, if `a' is an array, and variable object `A' was created for `a', then we'll get this output: (gdb) -var-info-expression A.1 ^done,lang="C",exp="1" Here, the value of `lang' is the language name, which can be found in *Note Supported Languages::. Note that the output of the `-var-list-children' command also includes those expressions, so the `-var-info-expression' command is of limited use. The `-var-info-path-expression' Command --------------------------------------- Synopsis ........ -var-info-path-expression NAME Returns an expression that can be evaluated in the current context and will yield the same value that a variable object has. Compare this with the `-var-info-expression' command, which result can be used only for UI presentation. Typical use of the `-var-info-path-expression' command is creating a watchpoint from a variable object. This command is currently not valid for children of a dynamic varobj, and will give an error when invoked on one. For example, suppose `C' is a C++ class, derived from class `Base', and that the `Base' class has a member called `m_size'. Assume a variable `c' is has the type of `C' and a variable object `C' was created for variable `c'. Then, we'll get this output: (gdb) -var-info-path-expression C.Base.public.m_size ^done,path_expr=((Base)c).m_size) The `-var-show-attributes' Command ---------------------------------- Synopsis ........ -var-show-attributes NAME List attributes of the specified variable object NAME: status=ATTR [ ( ,ATTR )* ] where ATTR is `{ { editable | noneditable } | TBD }'. The `-var-evaluate-expression' Command -------------------------------------- Synopsis ........ -var-evaluate-expression [-f FORMAT-SPEC] NAME Evaluates the expression that is represented by the specified variable object and returns its value as a string. The format of the string can be specified with the `-f' option. The possible values of this option are the same as for `-var-set-format' (*note -var-set-format::). If the `-f' option is not specified, the current display format will be used. The current display format can be changed using the `-var-set-format' command. value=VALUE Note that one must invoke `-var-list-children' for a variable before the value of a child variable can be evaluated. The `-var-assign' Command ------------------------- Synopsis ........ -var-assign NAME EXPRESSION Assigns the value of EXPRESSION to the variable object specified by NAME. The object must be `editable'. If the variable's value is altered by the assign, the variable will show up in any subsequent `-var-update' list. Example ....... (gdb) -var-assign var1 3 ^done,value="3" (gdb) -var-update * ^done,changelist=[{name="var1",in_scope="true",type_changed="false"}] (gdb) The `-var-update' Command ------------------------- Synopsis ........ -var-update [PRINT-VALUES] {NAME | "*"} Reevaluate the expressions corresponding to the variable object NAME and all its direct and indirect children, and return the list of variable objects whose values have changed; NAME must be a root variable object. Here, "changed" means that the result of `-var-evaluate-expression' before and after the `-var-update' is different. If `*' is used as the variable object names, all existing variable objects are updated, except for frozen ones (*note -var-set-frozen::). The option PRINT-VALUES determines whether both names and values, or just names are printed. The possible values of this option are the same as for `-var-list-children' (*note -var-list-children::). It is recommended to use the `--all-values' option, to reduce the number of MI commands needed on each program stop. With the `*' parameter, if a variable object is bound to a currently running thread, it will not be updated, without any diagnostic. If `-var-set-update-range' was previously used on a varobj, then only the selected range of children will be reported. `-var-update' reports all the changed varobjs in a tuple named `changelist'. Each item in the change list is itself a tuple holding: `name' The name of the varobj. `value' If values were requested for this update, then this field will be present and will hold the value of the varobj. `in_scope' This field is a string which may take one of three values: `"true"' The variable object's current value is valid. `"false"' The variable object does not currently hold a valid value but it may hold one in the future if its associated expression comes back into scope. `"invalid"' The variable object no longer holds a valid value. This can occur when the executable file being debugged has changed, either through recompilation or by using the GDB `file' command. The front end should normally choose to delete these variable objects. In the future new values may be added to this list so the front should be prepared for this possibility. *Note GDB/MI Development and Front Ends: GDB/MI Development and Front Ends. `type_changed' This is only present if the varobj is still valid. If the type changed, then this will be the string `true'; otherwise it will be `false'. When a varobj's type changes, its children are also likely to have become incorrect. Therefore, the varobj's children are automatically deleted when this attribute is `true'. Also, the varobj's update range, when set using the `-var-set-update-range' command, is unset. `new_type' If the varobj's type changed, then this field will be present and will hold the new type. `new_num_children' For a dynamic varobj, if the number of children changed, or if the type changed, this will be the new number of children. The `numchild' field in other varobj responses is generally not valid for a dynamic varobj - it will show the number of children that GDB knows about, but because dynamic varobjs lazily instantiate their children, this will not reflect the number of children which may be available. The `new_num_children' attribute only reports changes to the number of children known by GDB. This is the only way to detect whether an update has removed children (which necessarily can only happen at the end of the update range). `displayhint' The display hint, if any. `has_more' This is an integer value, which will be 1 if there are more children available outside the varobj's update range. `dynamic' This attribute will be present and have the value `1' if the varobj is a dynamic varobj. If the varobj is not a dynamic varobj, then this attribute will not be present. `new_children' If new children were added to a dynamic varobj within the selected update range (as set by `-var-set-update-range'), then they will be listed in this attribute. Example ....... (gdb) -var-assign var1 3 ^done,value="3" (gdb) -var-update --all-values var1 ^done,changelist=[{name="var1",value="3",in_scope="true", type_changed="false"}] (gdb) The `-var-set-frozen' Command ----------------------------- Synopsis ........ -var-set-frozen NAME FLAG Set the frozenness flag on the variable object NAME. The FLAG parameter should be either `1' to make the variable frozen or `0' to make it unfrozen. If a variable object is frozen, then neither itself, nor any of its children, are implicitly updated by `-var-update' of a parent variable or by `-var-update *'. Only `-var-update' of the variable itself will update its value and values of its children. After a variable object is unfrozen, it is implicitly updated by all subsequent `-var-update' operations. Unfreezing a variable does not update it, only subsequent `-var-update' does. Example ....... (gdb) -var-set-frozen V 1 ^done (gdb) The `-var-set-update-range' command ----------------------------------- Synopsis ........ -var-set-update-range NAME FROM TO Set the range of children to be returned by future invocations of `-var-update'. FROM and TO indicate the range of children to report. If FROM or TO is less than zero, the range is reset and all children will be reported. Otherwise, children starting at FROM (zero-based) and up to and excluding TO will be reported. Example ....... (gdb) -var-set-update-range V 1 2 ^done The `-var-set-visualizer' command --------------------------------- Synopsis ........ -var-set-visualizer NAME VISUALIZER Set a visualizer for the variable object NAME. VISUALIZER is the visualizer to use. The special value `None' means to disable any visualizer in use. If not `None', VISUALIZER must be a Python expression. This expression must evaluate to a callable object which accepts a single argument. GDB will call this object with the value of the varobj NAME as an argument (this is done so that the same Python pretty-printing code can be used for both the CLI and MI). When called, this object must return an object which conforms to the pretty-printing interface (*note Pretty Printing API::). The pre-defined function `gdb.default_visualizer' may be used to select a visualizer by following the built-in process (*note Selecting Pretty-Printers::). This is done automatically when a varobj is created, and so ordinarily is not needed. This feature is only available if Python support is enabled. The MI command `-list-features' (*note GDB/MI Support Commands::) can be used to check this. Example ....... Resetting the visualizer: (gdb) -var-set-visualizer V None ^done Reselecting the default (type-based) visualizer: (gdb) -var-set-visualizer V gdb.default_visualizer ^done Suppose `SomeClass' is a visualizer class. A lambda expression can be used to instantiate this class for a varobj: (gdb) -var-set-visualizer V "lambda val: SomeClass()" ^done  File: gdb.info, Node: GDB/MI Data Manipulation, Next: GDB/MI Tracepoint Commands, Prev: GDB/MI Variable Objects, Up: GDB/MI 27.16 GDB/MI Data Manipulation ============================== This section describes the GDB/MI commands that manipulate data: examine memory and registers, evaluate expressions, etc. For details about what an addressable memory unit is, *note addressable memory unit::. The `-data-disassemble' Command ------------------------------- Synopsis ........ -data-disassemble ( -s START-ADDR -e END-ADDR | -a ADDR | -f FILENAME -l LINENUM [ -n LINES ] ) [ --opcodes OPCODES-MODE ] [ --source ] [ -- MODE ] Where: `START-ADDR' is the beginning address (or `$pc') `END-ADDR' is the end address `ADDR' is an address anywhere within (or the name of) the function to disassemble. If an address is specified, the whole function surrounding that address will be disassembled. If a name is specified, the whole function with that name will be disassembled. `FILENAME' is the name of the file to disassemble `LINENUM' is the line number to disassemble around `LINES' is the number of disassembly lines to be produced. If it is -1, the whole function will be disassembled, in case no END-ADDR is specified. If END-ADDR is specified as a non-zero value, and LINES is lower than the number of disassembly lines between START-ADDR and END-ADDR, only LINES lines are displayed; if LINES is higher than the number of lines between START-ADDR and END-ADDR, only the lines up to END-ADDR are displayed. `OPCODES-MODE' can only be used with MODE 0, and should be one of the following: `none' no opcode information will be included in the result. `bytes' opcodes will be included in the result, the opcodes will be formatted as for `disassemble /b'. `display' opcodes will be included in the result, the opcodes will be formatted as for `disassemble /r'. `MODE' the use of MODE is deprecated in favour of using the `--opcodes' and `--source' options. When no MODE is given, MODE 0 will be assumed. However, the MODE is still available for backward compatibility. The MODE should be one of: `0' _disassembly only_, this is the default mode if no mode is specified. `1' _mixed source and disassembly (deprecated)_, it is not possible to recreate this mode using `--opcodes' and `--source' options. `2' _disassembly with raw opcodes_, this mode is equivalent to using MODE 0 and passing `--opcodes bytes' to the command. `3' _mixed source and disassembly with raw opcodes (deprecated)_, it is not possible to recreate this mode using `--opcodes' and `--source' options. `4' _mixed source and disassembly_, this mode is equivalent to using MODE 0 and passing `--source' to the command. `5' _mixed source and disassembly with raw opcodes_, this mode is equivalent to using MODE 0 and passing `--opcodes bytes' and `--source' to the command. Modes 1 and 3 are deprecated. The output is "source centric" which hasn't proved useful in practice. *Note Machine Code::, for a discussion of the difference between `/m' and `/s' output of the `disassemble' command. The `--source' can only be used with MODE 0. Passing this option will include the source code in the disassembly result as if MODE 4 or 5 had been used. Result ...... The result of the `-data-disassemble' command will be a list named `asm_insns', the contents of this list depend on the options used with the `-data-disassemble' command. For modes 0 and 2, and when the `--source' option is not used, the `asm_insns' list contains tuples with the following fields: `address' The address at which this instruction was disassembled. `func-name' The name of the function this instruction is within. `offset' The decimal offset in bytes from the start of `func-name'. `inst' The text disassembly for this `address'. `opcodes' This field is only present for modes 2, 3 and 5, or when the `--opcodes' option `bytes' or `display' is used. This contains the raw opcode bytes for the `inst' field. When the `--opcodes' option is not passed to `-data-disassemble', or the `bytes' value is passed to `--opcodes', then the bytes are formatted as a series of single bytes, in hex, in ascending address order, with a single space between each byte. This format is equivalent to the `/b' option being used with the `disassemble' command (*note `disassemble': disassemble.). When `--opcodes' is passed the value `display' then the bytes are formatted in the natural instruction display order. This means multiple bytes can be grouped together, and the bytes might be byte-swapped. This format is equivalent to the `/r' option being used with the `disassemble' command. For modes 1, 3, 4 and 5, or when the `--source' option is used, the `asm_insns' list contains tuples named `src_and_asm_line', each of which has the following fields: `line' The line number within `file'. `file' The file name from the compilation unit. This might be an absolute file name or a relative file name depending on the compile command used. `fullname' Absolute file name of `file'. It is converted to a canonical form using the source file search path (*note Specifying Source Directories: Source Path.) and after resolving all the symbolic links. If the source file is not found this field will contain the path as present in the debug information. `line_asm_insn' This is a list of tuples containing the disassembly for `line' in `file'. The fields of each tuple are the same as for `-data-disassemble' in MODE 0 and 2, so `address', `func-name', `offset', `inst', and optionally `opcodes'. Note that whatever included in the `inst' field, is not manipulated directly by GDB/MI, i.e., it is not possible to adjust its format. GDB Command ........... The corresponding GDB command is `disassemble'. Example ....... Disassemble from the current value of `$pc' to `$pc + 20': (gdb) -data-disassemble -s $pc -e "$pc + 20" -- 0 ^done, asm_insns=[ {address="0x000107c0",func-name="main",offset="4", inst="mov 2, %o0"}, {address="0x000107c4",func-name="main",offset="8", inst="sethi %hi(0x11800), %o2"}, {address="0x000107c8",func-name="main",offset="12", inst="or %o2, 0x140, %o1\t! 0x11940 <_lib_version+8>"}, {address="0x000107cc",func-name="main",offset="16", inst="sethi %hi(0x11800), %o2"}, {address="0x000107d0",func-name="main",offset="20", inst="or %o2, 0x168, %o4\t! 0x11968 <_lib_version+48>"}] (gdb) Disassemble the whole `main' function. Line 32 is part of `main'. -data-disassemble -f basics.c -l 32 -- 0 ^done,asm_insns=[ {address="0x000107bc",func-name="main",offset="0", inst="save %sp, -112, %sp"}, {address="0x000107c0",func-name="main",offset="4", inst="mov 2, %o0"}, {address="0x000107c4",func-name="main",offset="8", inst="sethi %hi(0x11800), %o2"}, [...] {address="0x0001081c",func-name="main",offset="96",inst="ret "}, {address="0x00010820",func-name="main",offset="100",inst="restore "}] (gdb) Disassemble 3 instructions from the start of `main': (gdb) -data-disassemble -f basics.c -l 32 -n 3 -- 0 ^done,asm_insns=[ {address="0x000107bc",func-name="main",offset="0", inst="save %sp, -112, %sp"}, {address="0x000107c0",func-name="main",offset="4", inst="mov 2, %o0"}, {address="0x000107c4",func-name="main",offset="8", inst="sethi %hi(0x11800), %o2"}] (gdb) Disassemble 3 instructions from the start of `main' in mixed mode: (gdb) -data-disassemble -f basics.c -l 32 -n 3 -- 1 ^done,asm_insns=[ src_and_asm_line={line="31", file="../../../src/gdb/testsuite/gdb.mi/basics.c", fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c", line_asm_insn=[{address="0x000107bc", func-name="main",offset="0",inst="save %sp, -112, %sp"}]}, src_and_asm_line={line="32", file="../../../src/gdb/testsuite/gdb.mi/basics.c", fullname="/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c", line_asm_insn=[{address="0x000107c0", func-name="main",offset="4",inst="mov 2, %o0"}, {address="0x000107c4",func-name="main",offset="8", inst="sethi %hi(0x11800), %o2"}]}] (gdb) The `-data-evaluate-expression' Command --------------------------------------- Synopsis ........ -data-evaluate-expression EXPR Evaluate EXPR as an expression. The expression could contain an inferior function call. The function call will execute synchronously. If the expression contains spaces, it must be enclosed in double quotes. GDB Command ........... The corresponding GDB commands are `print', `output', and `call'. In `gdbtk' only, there's a corresponding `gdb_eval' command. Example ....... In the following example, the numbers that precede the commands are the "tokens" described in *Note GDB/MI Command Syntax: GDB/MI Command Syntax. Notice how GDB/MI returns the same tokens in its output. 211-data-evaluate-expression A 211^done,value="1" (gdb) 311-data-evaluate-expression &A 311^done,value="0xefffeb7c" (gdb) 411-data-evaluate-expression A+3 411^done,value="4" (gdb) 511-data-evaluate-expression "A + 3" 511^done,value="4" (gdb) The `-data-list-changed-registers' Command ------------------------------------------ Synopsis ........ -data-list-changed-registers Display a list of the registers that have changed. GDB Command ........... GDB doesn't have a direct analog for this command; `gdbtk' has the corresponding command `gdb_changed_register_list'. Example ....... On a PPC MBX board: (gdb) -exec-continue ^running (gdb) *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame={ func="main",args=[],file="try.c",fullname="/home/foo/bar/try.c", line="5",arch="powerpc"} (gdb) -data-list-changed-registers ^done,changed-registers=["0","1","2","4","5","6","7","8","9", "10","11","13","14","15","16","17","18","19","20","21","22","23", "24","25","26","27","28","30","31","64","65","66","67","69"] (gdb) The `-data-list-register-names' Command --------------------------------------- Synopsis ........ -data-list-register-names [ ( REGNO )+ ] Show a list of register names for the current target. If no arguments are given, it shows a list of the names of all the registers. If integer numbers are given as arguments, it will print a list of the names of the registers corresponding to the arguments. To ensure consistency between a register name and its number, the output list may include empty register names. GDB Command ........... GDB does not have a command which corresponds to `-data-list-register-names'. In `gdbtk' there is a corresponding command `gdb_regnames'. Example ....... For the PPC MBX board: (gdb) -data-list-register-names ^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7", "r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18", "r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29", "r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9", "f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20", "f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31", "", "pc","ps","cr","lr","ctr","xer"] (gdb) -data-list-register-names 1 2 3 ^done,register-names=["r1","r2","r3"] (gdb) The `-data-list-register-values' Command ---------------------------------------- Synopsis ........ -data-list-register-values [ `--skip-unavailable' ] FMT [ ( REGNO )*] Display the registers' contents. The format according to which the registers' contents are to be returned is given by FMT, followed by an optional list of numbers specifying the registers to display. A missing list of numbers indicates that the contents of all the registers must be returned. The `--skip-unavailable' option indicates that only the available registers are to be returned. Allowed formats for FMT are: `x' Hexadecimal `o' Octal `t' Binary `d' Decimal `r' Raw `N' Natural GDB Command ........... The corresponding GDB commands are `info reg', `info all-reg', and (in `gdbtk') `gdb_fetch_registers'. Example ....... For a PPC MBX board (note: line breaks are for readability only, they don't appear in the actual output): (gdb) -data-list-register-values r 64 65 ^done,register-values=[{number="64",value="0xfe00a300"}, {number="65",value="0x00029002"}] (gdb) -data-list-register-values x ^done,register-values=[{number="0",value="0xfe0043c8"}, {number="1",value="0x3fff88"},{number="2",value="0xfffffffe"}, {number="3",value="0x0"},{number="4",value="0xa"}, {number="5",value="0x3fff68"},{number="6",value="0x3fff58"}, {number="7",value="0xfe011e98"},{number="8",value="0x2"}, {number="9",value="0xfa202820"},{number="10",value="0xfa202808"}, {number="11",value="0x1"},{number="12",value="0x0"}, {number="13",value="0x4544"},{number="14",value="0xffdfffff"}, {number="15",value="0xffffffff"},{number="16",value="0xfffffeff"}, {number="17",value="0xefffffed"},{number="18",value="0xfffffffe"}, {number="19",value="0xffffffff"},{number="20",value="0xffffffff"}, {number="21",value="0xffffffff"},{number="22",value="0xfffffff7"}, {number="23",value="0xffffffff"},{number="24",value="0xffffffff"}, {number="25",value="0xffffffff"},{number="26",value="0xfffffffb"}, {number="27",value="0xffffffff"},{number="28",value="0xf7bfffff"}, {number="29",value="0x0"},{number="30",value="0xfe010000"}, {number="31",value="0x0"},{number="32",value="0x0"}, {number="33",value="0x0"},{number="34",value="0x0"}, {number="35",value="0x0"},{number="36",value="0x0"}, {number="37",value="0x0"},{number="38",value="0x0"}, {number="39",value="0x0"},{number="40",value="0x0"}, {number="41",value="0x0"},{number="42",value="0x0"}, {number="43",value="0x0"},{number="44",value="0x0"}, {number="45",value="0x0"},{number="46",value="0x0"}, {number="47",value="0x0"},{number="48",value="0x0"}, {number="49",value="0x0"},{number="50",value="0x0"}, {number="51",value="0x0"},{number="52",value="0x0"}, {number="53",value="0x0"},{number="54",value="0x0"}, {number="55",value="0x0"},{number="56",value="0x0"}, {number="57",value="0x0"},{number="58",value="0x0"}, {number="59",value="0x0"},{number="60",value="0x0"}, {number="61",value="0x0"},{number="62",value="0x0"}, {number="63",value="0x0"},{number="64",value="0xfe00a300"}, {number="65",value="0x29002"},{number="66",value="0x202f04b5"}, {number="67",value="0xfe0043b0"},{number="68",value="0xfe00b3e4"}, {number="69",value="0x20002b03"}] (gdb) The `-data-read-memory' Command ------------------------------- This command is deprecated, use `-data-read-memory-bytes' instead. Synopsis ........ -data-read-memory [ -o BYTE-OFFSET ] ADDRESS WORD-FORMAT WORD-SIZE NR-ROWS NR-COLS [ ASCHAR ] where: `ADDRESS' An expression specifying the address of the first memory word to be read. Complex expressions containing embedded white space should be quoted using the C convention. `WORD-FORMAT' The format to be used to print the memory words. The notation is the same as for GDB's `print' command (*note Output Formats: Output Formats.). `WORD-SIZE' The size of each memory word in bytes. `NR-ROWS' The number of rows in the output table. `NR-COLS' The number of columns in the output table. `ASCHAR' If present, indicates that each row should include an ASCII dump. The value of ASCHAR is used as a padding character when a byte is not a member of the printable ASCII character set (printable ASCII characters are those whose code is between 32 and 126, inclusively). `BYTE-OFFSET' An offset to add to the ADDRESS before fetching memory. This command displays memory contents as a table of NR-ROWS by NR-COLS words, each word being WORD-SIZE bytes. In total, `NR-ROWS * NR-COLS * WORD-SIZE' bytes are read (returned as `total-bytes'). Should less than the requested number of bytes be returned by the target, the missing words are identified using `N/A'. The number of bytes read from the target is returned in `nr-bytes' and the starting address used to read memory in `addr'. The address of the next/previous row or page is available in `next-row' and `prev-row', `next-page' and `prev-page'. GDB Command ........... The corresponding GDB command is `x'. `gdbtk' has `gdb_get_mem' memory read command. Example ....... Read six bytes of memory starting at `bytes+6' but then offset by `-6' bytes. Format as three rows of two columns. One byte per word. Display each word in hex. (gdb) 9-data-read-memory -o -6 -- bytes+6 x 1 3 2 9^done,addr="0x00001390",nr-bytes="6",total-bytes="6", next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396", prev-page="0x0000138a",memory=[ {addr="0x00001390",data=["0x00","0x01"]}, {addr="0x00001392",data=["0x02","0x03"]}, {addr="0x00001394",data=["0x04","0x05"]}] (gdb) Read two bytes of memory starting at address `shorts + 64' and display as a single word formatted in decimal. (gdb) 5-data-read-memory shorts+64 d 2 1 1 5^done,addr="0x00001510",nr-bytes="2",total-bytes="2", next-row="0x00001512",prev-row="0x0000150e", next-page="0x00001512",prev-page="0x0000150e",memory=[ {addr="0x00001510",data=["128"]}] (gdb) Read thirty two bytes of memory starting at `bytes+16' and format as eight rows of four columns. Include a string encoding with `x' used as the non-printable character. (gdb) 4-data-read-memory bytes+16 x 1 8 4 x 4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32", next-row="0x000013c0",prev-row="0x0000139c", next-page="0x000013c0",prev-page="0x00001380",memory=[ {addr="0x000013a0",data=["0x10","0x11","0x12","0x13"],ascii="xxxx"}, {addr="0x000013a4",data=["0x14","0x15","0x16","0x17"],ascii="xxxx"}, {addr="0x000013a8",data=["0x18","0x19","0x1a","0x1b"],ascii="xxxx"}, {addr="0x000013ac",data=["0x1c","0x1d","0x1e","0x1f"],ascii="xxxx"}, {addr="0x000013b0",data=["0x20","0x21","0x22","0x23"],ascii=" !\"#"}, {addr="0x000013b4",data=["0x24","0x25","0x26","0x27"],ascii="$%&'"}, {addr="0x000013b8",data=["0x28","0x29","0x2a","0x2b"],ascii="()*+"}, {addr="0x000013bc",data=["0x2c","0x2d","0x2e","0x2f"],ascii=",-./"}] (gdb) The `-data-read-memory-bytes' Command ------------------------------------- Synopsis ........ -data-read-memory-bytes [ -o OFFSET ] ADDRESS COUNT where: `ADDRESS' An expression specifying the address of the first addressable memory unit to be read. Complex expressions containing embedded white space should be quoted using the C convention. `COUNT' The number of addressable memory units to read. This should be an integer literal. `OFFSET' The offset relative to ADDRESS at which to start reading. This should be an integer literal. This option is provided so that a frontend is not required to first evaluate address and then perform address arithmetic itself. This command attempts to read all accessible memory regions in the specified range. First, all regions marked as unreadable in the memory map (if one is defined) will be skipped. *Note Memory Region Attributes::. Second, GDB will attempt to read the remaining regions. For each one, if reading full region results in an errors, GDB will try to read a subset of the region. In general, every single memory unit in the region may be readable or not, and the only way to read every readable unit is to try a read at every address, which is not practical. Therefore, GDB will attempt to read all accessible memory units at either beginning or the end of the region, using a binary division scheme. This heuristic works well for reading across a memory map boundary. Note that if a region has a readable range that is neither at the beginning or the end, GDB will not read it. The result record (*note GDB/MI Result Records::) that is output of the command includes a field named `memory' whose content is a list of tuples. Each tuple represent a successfully read memory block and has the following fields: `begin' The start address of the memory block, as hexadecimal literal. `end' The end address of the memory block, as hexadecimal literal. `offset' The offset of the memory block, as hexadecimal literal, relative to the start address passed to `-data-read-memory-bytes'. `contents' The contents of the memory block, in hex. GDB Command ........... The corresponding GDB command is `x'. Example ....... (gdb) -data-read-memory-bytes &a 10 ^done,memory=[{begin="0xbffff154",offset="0x00000000", end="0xbffff15e", contents="01000000020000000300"}] (gdb) The `-data-write-memory-bytes' Command -------------------------------------- Synopsis ........ -data-write-memory-bytes ADDRESS CONTENTS -data-write-memory-bytes ADDRESS CONTENTS [COUNT] where: `ADDRESS' An expression specifying the address of the first addressable memory unit to be written. Complex expressions containing embedded white space should be quoted using the C convention. `CONTENTS' The hex-encoded data to write. It is an error if CONTENTS does not represent an integral number of addressable memory units. `COUNT' Optional argument indicating the number of addressable memory units to be written. If COUNT is greater than CONTENTS' length, GDB will repeatedly write CONTENTS until it fills COUNT memory units. GDB Command ........... There's no corresponding GDB command. Example ....... (gdb) -data-write-memory-bytes &a "aabbccdd" ^done (gdb) (gdb) -data-write-memory-bytes &a "aabbccdd" 16e ^done (gdb)  File: gdb.info, Node: GDB/MI Tracepoint Commands, Next: GDB/MI Symbol Query, Prev: GDB/MI Data Manipulation, Up: GDB/MI 27.17 GDB/MI Tracepoint Commands ================================ The commands defined in this section implement MI support for tracepoints. For detailed introduction, see *Note Tracepoints::. The `-trace-find' Command ------------------------- Synopsis ........ -trace-find MODE [PARAMETERS...] Find a trace frame using criteria defined by MODE and PARAMETERS. The following table lists permissible modes and their parameters. For details of operation, see *Note tfind::. `none' No parameters are required. Stops examining trace frames. `frame-number' An integer is required as parameter. Selects tracepoint frame with that index. `tracepoint-number' An integer is required as parameter. Finds next trace frame that corresponds to tracepoint with the specified number. `pc' An address is required as parameter. Finds next trace frame that corresponds to any tracepoint at the specified address. `pc-inside-range' Two addresses are required as parameters. Finds next trace frame that corresponds to a tracepoint at an address inside the specified range. Both bounds are considered to be inside the range. `pc-outside-range' Two addresses are required as parameters. Finds next trace frame that corresponds to a tracepoint at an address outside the specified range. Both bounds are considered to be inside the range. `line' Location specification is required as parameter. *Note Location Specifications::. Finds next trace frame that corresponds to a tracepoint at the specified location. If `none' was passed as MODE, the response does not have fields. Otherwise, the response may have the following fields: `found' This field has either `0' or `1' as the value, depending on whether a matching tracepoint was found. `traceframe' The index of the found traceframe. This field is present iff the `found' field has value of `1'. `tracepoint' The index of the found tracepoint. This field is present iff the `found' field has value of `1'. `frame' The information about the frame corresponding to the found trace frame. This field is present only if a trace frame was found. *Note GDB/MI Frame Information::, for description of this field. GDB Command ........... The corresponding GDB command is `tfind'. The `-trace-define-variable' Command ------------------------------------ Synopsis ........ -trace-define-variable NAME [ VALUE ] Create trace variable NAME if it does not exist. If VALUE is specified, sets the initial value of the specified trace variable to that value. Note that the NAME should start with the `$' character. GDB Command ........... The corresponding GDB command is `tvariable'. The `-trace-frame-collected' Command ------------------------------------ Synopsis ........ -trace-frame-collected [--var-print-values VAR_PVAL] [--comp-print-values COMP_PVAL] [--registers-format REGFORMAT] [--memory-contents] This command returns the set of collected objects, register names, trace state variable names, memory ranges and computed expressions that have been collected at a particular trace frame. The optional parameters to the command affect the output format in different ways. See the output description table below for more details. The reported names can be used in the normal manner to create varobjs and inspect the objects themselves. The items returned by this command are categorized so that it is clear which is a variable, which is a register, which is a trace state variable, which is a memory range and which is a computed expression. For instance, if the actions were collect myVar, myArray[myIndex], myObj.field, myPtr->field, myCount + 2 collect *(int*)0xaf02bef0@@40 the object collected in its entirety would be `myVar'. The object `myArray' would be partially collected, because only the element at index `myIndex' would be collected. The remaining objects would be computed expressions. An example output would be: (gdb) -trace-frame-collected ^done, explicit-variables=[{name="myVar",value="1"}], computed-expressions=[{name="myArray[myIndex]",value="0"}, {name="myObj.field",value="0"}, {name="myPtr->field",value="1"}, {name="myCount + 2",value="3"}, {name="$tvar1 + 1",value="43970027"}], registers=[{number="0",value="0x7fe2c6e79ec8"}, {number="1",value="0x0"}, {number="2",value="0x4"}, ... {number="125",value="0x0"}], tvars=[{name="$tvar1",current="43970026"}], memory=[{address="0x0000000000602264",length="4"}, {address="0x0000000000615bc0",length="4"}] (gdb) Where: `explicit-variables' The set of objects that have been collected in their entirety (as opposed to collecting just a few elements of an array or a few struct members). For each object, its name and value are printed. The `--var-print-values' option affects how or whether the value field is output. If VAR_PVAL is 0, then print only the names; if it is 1, print also their values; and if it is 2, print the name, type and value for simple data types, and the name and type for arrays, structures and unions. `computed-expressions' The set of computed expressions that have been collected at the current trace frame. The `--comp-print-values' option affects this set like the `--var-print-values' option affects the `explicit-variables' set. See above. `registers' The registers that have been collected at the current trace frame. For each register collected, the name and current value are returned. The value is formatted according to the `--registers-format' option. See the `-data-list-register-values' command for a list of the allowed formats. The default is `x'. `tvars' The trace state variables that have been collected at the current trace frame. For each trace state variable collected, the name and current value are returned. `memory' The set of memory ranges that have been collected at the current trace frame. Its content is a list of tuples. Each tuple represents a collected memory range and has the following fields: `address' The start address of the memory range, as hexadecimal literal. `length' The length of the memory range, as decimal literal. `contents' The contents of the memory block, in hex. This field is only present if the `--memory-contents' option is specified. GDB Command ........... There is no corresponding GDB command. Example ....... The `-trace-list-variables' Command ----------------------------------- Synopsis ........ -trace-list-variables Return a table of all defined trace variables. Each element of the table has the following fields: `name' The name of the trace variable. This field is always present. `initial' The initial value. This is a 64-bit signed integer. This field is always present. `current' The value the trace variable has at the moment. This is a 64-bit signed integer. This field is absent iff current value is not defined, for example if the trace was never run, or is presently running. GDB Command ........... The corresponding GDB command is `tvariables'. Example ....... (gdb) -trace-list-variables ^done,trace-variables={nr_rows="1",nr_cols="3", hdr=[{width="15",alignment="-1",col_name="name",colhdr="Name"}, {width="11",alignment="-1",col_name="initial",colhdr="Initial"}, {width="11",alignment="-1",col_name="current",colhdr="Current"}], body=[variable={name="$trace_timestamp",initial="0"} variable={name="$foo",initial="10",current="15"}]} (gdb) The `-trace-save' Command ------------------------- Synopsis ........ -trace-save [ -r ] [ -ctf ] FILENAME Saves the collected trace data to FILENAME. Without the `-r' option, the data is downloaded from the target and saved in a local file. With the `-r' option the target is asked to perform the save. By default, this command will save the trace in the tfile format. You can supply the optional `-ctf' argument to save it the CTF format. See *Note Trace Files:: for more information about CTF. GDB Command ........... The corresponding GDB command is `tsave'. The `-trace-start' Command -------------------------- Synopsis ........ -trace-start Starts a tracing experiment. The result of this command does not have any fields. GDB Command ........... The corresponding GDB command is `tstart'. The `-trace-status' Command --------------------------- Synopsis ........ -trace-status Obtains the status of a tracing experiment. The result may include the following fields: `supported' May have a value of either `0', when no tracing operations are supported, `1', when all tracing operations are supported, or `file' when examining trace file. In the latter case, examining of trace frame is possible but new tracing experiment cannot be started. This field is always present. `running' May have a value of either `0' or `1' depending on whether tracing experiment is in progress on target. This field is present if `supported' field is not `0'. `stop-reason' Report the reason why the tracing was stopped last time. This field may be absent iff tracing was never stopped on target yet. The value of `request' means the tracing was stopped as result of the `-trace-stop' command. The value of `overflow' means the tracing buffer is full. The value of `disconnection' means tracing was automatically stopped when GDB has disconnected. The value of `passcount' means tracing was stopped when a tracepoint was passed a maximal number of times for that tracepoint. This field is present if `supported' field is not `0'. `stopping-tracepoint' The number of tracepoint whose passcount as exceeded. This field is present iff the `stop-reason' field has the value of `passcount'. `frames' `frames-created' The `frames' field is a count of the total number of trace frames in the trace buffer, while `frames-created' is the total created during the run, including ones that were discarded, such as when a circular trace buffer filled up. Both fields are optional. `buffer-size' `buffer-free' These fields tell the current size of the tracing buffer and the remaining space. These fields are optional. `circular' The value of the circular trace buffer flag. `1' means that the trace buffer is circular and old trace frames will be discarded if necessary to make room, `0' means that the trace buffer is linear and may fill up. `disconnected' The value of the disconnected tracing flag. `1' means that tracing will continue after GDB disconnects, `0' means that the trace run will stop. `trace-file' The filename of the trace file being examined. This field is optional, and only present when examining a trace file. GDB Command ........... The corresponding GDB command is `tstatus'. The `-trace-stop' Command ------------------------- Synopsis ........ -trace-stop Stops a tracing experiment. The result of this command has the same fields as `-trace-status', except that the `supported' and `running' fields are not output. GDB Command ........... The corresponding GDB command is `tstop'.  File: gdb.info, Node: GDB/MI Symbol Query, Next: GDB/MI File Commands, Prev: GDB/MI Tracepoint Commands, Up: GDB/MI 27.18 GDB/MI Symbol Query Commands ================================== The `-symbol-info-functions' Command ------------------------------------ Synopsis ........ -symbol-info-functions [--include-nondebug] [--type TYPE_REGEXP] [--name NAME_REGEXP] [--max-results LIMIT] Return a list containing the names and types for all global functions taken from the debug information. The functions are grouped by source file, and shown with the line number on which each function is defined. The `--include-nondebug' option causes the output to include code symbols from the symbol table. The options `--type' and `--name' allow the symbols returned to be filtered based on either the name of the function, or the type signature of the function. The option `--max-results' restricts the command to return no more than LIMIT results. If exactly LIMIT results are returned then there might be additional results available if a higher limit is used. GDB Command ........... The corresponding GDB command is `info functions'. Example ....... (gdb) -symbol-info-functions ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="36", name="f4", type="void (int *)", description="void f4(int *);"}, {line="42", name="main", type="int ()", description="int main();"}, {line="30", name="f1", type="my_int_t (int, int)", description="static my_int_t f1(int, int);"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="33", name="f2", type="float (another_float_t)", description="float f2(another_float_t);"}, {line="39", name="f3", type="int (another_int_t)", description="int f3(another_int_t);"}, {line="27", name="f1", type="another_float_t (int)", description="static another_float_t f1(int);"}]}]} (gdb) -symbol-info-functions --name f1 ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="30", name="f1", type="my_int_t (int, int)", description="static my_int_t f1(int, int);"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="27", name="f1", type="another_float_t (int)", description="static another_float_t f1(int);"}]}]} (gdb) -symbol-info-functions --type void ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="36", name="f4", type="void (int *)", description="void f4(int *);"}]}]} (gdb) -symbol-info-functions --include-nondebug ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="36", name="f4", type="void (int *)", description="void f4(int *);"}, {line="42", name="main", type="int ()", description="int main();"}, {line="30", name="f1", type="my_int_t (int, int)", description="static my_int_t f1(int, int);"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="33", name="f2", type="float (another_float_t)", description="float f2(another_float_t);"}, {line="39", name="f3", type="int (another_int_t)", description="int f3(another_int_t);"}, {line="27", name="f1", type="another_float_t (int)", description="static another_float_t f1(int);"}]}], nondebug= [{address="0x0000000000400398",name="_init"}, {address="0x00000000004003b0",name="_start"}, ... ]} The `-symbol-info-module-functions' Command ------------------------------------------- Synopsis ........ -symbol-info-module-functions [--module MODULE_REGEXP] [--name NAME_REGEXP] [--type TYPE_REGEXP] Return a list containing the names of all known functions within all know Fortran modules. The functions are grouped by source file and containing module, and shown with the line number on which each function is defined. The option `--module' only returns results for modules matching MODULE_REGEXP. The option `--name' only returns functions whose name matches NAME_REGEXP, and `--type' only returns functions whose type matches TYPE_REGEXP. GDB Command ........... The corresponding GDB command is `info module functions'. Example ....... (gdb) -symbol-info-module-functions ^done,symbols= [{module="mod1", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", symbols=[{line="21",name="mod1::check_all",type="void (void)", description="void mod1::check_all(void);"}]}]}, {module="mod2", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", symbols=[{line="30",name="mod2::check_var_i",type="void (void)", description="void mod2::check_var_i(void);"}]}]}, {module="mod3", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="21",name="mod3::check_all",type="void (void)", description="void mod3::check_all(void);"}, {line="27",name="mod3::check_mod2",type="void (void)", description="void mod3::check_mod2(void);"}]}]}, {module="modmany", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="35",name="modmany::check_some",type="void (void)", description="void modmany::check_some(void);"}]}]}, {module="moduse", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="44",name="moduse::check_all",type="void (void)", description="void moduse::check_all(void);"}, {line="49",name="moduse::check_var_x",type="void (void)", description="void moduse::check_var_x(void);"}]}]}] The `-symbol-info-module-variables' Command ------------------------------------------- Synopsis ........ -symbol-info-module-variables [--module MODULE_REGEXP] [--name NAME_REGEXP] [--type TYPE_REGEXP] Return a list containing the names of all known variables within all know Fortran modules. The variables are grouped by source file and containing module, and shown with the line number on which each variable is defined. The option `--module' only returns results for modules matching MODULE_REGEXP. The option `--name' only returns variables whose name matches NAME_REGEXP, and `--type' only returns variables whose type matches TYPE_REGEXP. GDB Command ........... The corresponding GDB command is `info module variables'. Example ....... (gdb) -symbol-info-module-variables ^done,symbols= [{module="mod1", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", symbols=[{line="18",name="mod1::var_const",type="integer(kind=4)", description="integer(kind=4) mod1::var_const;"}, {line="17",name="mod1::var_i",type="integer(kind=4)", description="integer(kind=4) mod1::var_i;"}]}]}, {module="mod2", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", symbols=[{line="28",name="mod2::var_i",type="integer(kind=4)", description="integer(kind=4) mod2::var_i;"}]}]}, {module="mod3", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="18",name="mod3::mod1",type="integer(kind=4)", description="integer(kind=4) mod3::mod1;"}, {line="17",name="mod3::mod2",type="integer(kind=4)", description="integer(kind=4) mod3::mod2;"}, {line="19",name="mod3::var_i",type="integer(kind=4)", description="integer(kind=4) mod3::var_i;"}]}]}, {module="modmany", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="33",name="modmany::var_a",type="integer(kind=4)", description="integer(kind=4) modmany::var_a;"}, {line="33",name="modmany::var_b",type="integer(kind=4)", description="integer(kind=4) modmany::var_b;"}, {line="33",name="modmany::var_c",type="integer(kind=4)", description="integer(kind=4) modmany::var_c;"}, {line="33",name="modmany::var_i",type="integer(kind=4)", description="integer(kind=4) modmany::var_i;"}]}]}, {module="moduse", files=[{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="42",name="moduse::var_x",type="integer(kind=4)", description="integer(kind=4) moduse::var_x;"}, {line="42",name="moduse::var_y",type="integer(kind=4)", description="integer(kind=4) moduse::var_y;"}]}]}] The `-symbol-info-modules' Command ---------------------------------- Synopsis ........ -symbol-info-modules [--name NAME_REGEXP] [--max-results LIMIT] Return a list containing the names of all known Fortran modules. The modules are grouped by source file, and shown with the line number on which each modules is defined. The option `--name' allows the modules returned to be filtered based the name of the module. The option `--max-results' restricts the command to return no more than LIMIT results. If exactly LIMIT results are returned then there might be additional results available if a higher limit is used. GDB Command ........... The corresponding GDB command is `info modules'. Example ....... (gdb) -symbol-info-modules ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", symbols=[{line="16",name="mod1"}, {line="22",name="mod2"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="16",name="mod3"}, {line="22",name="modmany"}, {line="26",name="moduse"}]}]} (gdb) -symbol-info-modules --name mod[123] ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules-2.f90", symbols=[{line="16",name="mod1"}, {line="22",name="mod2"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", fullname="/project/gdb/testsuite/gdb.mi/mi-fortran-modules.f90", symbols=[{line="16",name="mod3"}]}]} The `-symbol-info-types' Command -------------------------------- Synopsis ........ -symbol-info-types [--name NAME_REGEXP] [--max-results LIMIT] Return a list of all defined types. The types are grouped by source file, and shown with the line number on which each user defined type is defined. Some base types are not defined in the source code but are added to the debug information by the compiler, for example `int', `float', etc.; these types do not have an associated line number. The option `--name' allows the list of types returned to be filtered by name. The option `--max-results' restricts the command to return no more than LIMIT results. If exactly LIMIT results are returned then there might be additional results available if a higher limit is used. GDB Command ........... The corresponding GDB command is `info types'. Example ....... (gdb) -symbol-info-types ^done,symbols= {debug= [{filename="gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{name="float"}, {name="int"}, {line="27",name="typedef int my_int_t;"}]}, {filename="gdb.mi/mi-sym-info-2.c", fullname="/project/gdb.mi/mi-sym-info-2.c", symbols=[{line="24",name="typedef float another_float_t;"}, {line="23",name="typedef int another_int_t;"}, {name="float"}, {name="int"}]}]} (gdb) -symbol-info-types --name _int_ ^done,symbols= {debug= [{filename="gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="27",name="typedef int my_int_t;"}]}, {filename="gdb.mi/mi-sym-info-2.c", fullname="/project/gdb.mi/mi-sym-info-2.c", symbols=[{line="23",name="typedef int another_int_t;"}]}]} The `-symbol-info-variables' Command ------------------------------------ Synopsis ........ -symbol-info-variables [--include-nondebug] [--type TYPE_REGEXP] [--name NAME_REGEXP] [--max-results LIMIT] Return a list containing the names and types for all global variables taken from the debug information. The variables are grouped by source file, and shown with the line number on which each variable is defined. The `--include-nondebug' option causes the output to include data symbols from the symbol table. The options `--type' and `--name' allow the symbols returned to be filtered based on either the name of the variable, or the type of the variable. The option `--max-results' restricts the command to return no more than LIMIT results. If exactly LIMIT results are returned then there might be additional results available if a higher limit is used. GDB Command ........... The corresponding GDB command is `info variables'. Example ....... (gdb) -symbol-info-variables ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="25",name="global_f1",type="float", description="static float global_f1;"}, {line="24",name="global_i1",type="int", description="static int global_i1;"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="21",name="global_f2",type="int", description="int global_f2;"}, {line="20",name="global_i2",type="int", description="int global_i2;"}, {line="19",name="global_f1",type="float", description="static float global_f1;"}, {line="18",name="global_i1",type="int", description="static int global_i1;"}]}]} (gdb) -symbol-info-variables --name f1 ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="25",name="global_f1",type="float", description="static float global_f1;"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="19",name="global_f1",type="float", description="static float global_f1;"}]}]} (gdb) -symbol-info-variables --type float ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="25",name="global_f1",type="float", description="static float global_f1;"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="19",name="global_f1",type="float", description="static float global_f1;"}]}]} (gdb) -symbol-info-variables --include-nondebug ^done,symbols= {debug= [{filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-1.c", symbols=[{line="25",name="global_f1",type="float", description="static float global_f1;"}, {line="24",name="global_i1",type="int", description="static int global_i1;"}]}, {filename="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", fullname="/project/gdb/testsuite/gdb.mi/mi-sym-info-2.c", symbols=[{line="21",name="global_f2",type="int", description="int global_f2;"}, {line="20",name="global_i2",type="int", description="int global_i2;"}, {line="19",name="global_f1",type="float", description="static float global_f1;"}, {line="18",name="global_i1",type="int", description="static int global_i1;"}]}], nondebug= [{address="0x00000000004005d0",name="_IO_stdin_used"}, {address="0x00000000004005d8",name="__dso_handle"} ... ]} The `-symbol-list-lines' Command -------------------------------- Synopsis ........ -symbol-list-lines FILENAME Print the list of lines that contain code and their associated program addresses for the given source filename. The entries are sorted in ascending PC order. GDB Command ........... There is no corresponding GDB command. Example ....... (gdb) -symbol-list-lines basics.c ^done,lines=[{pc="0x08048554",line="7"},{pc="0x0804855a",line="8"}] (gdb)  File: gdb.info, Node: GDB/MI File Commands, Next: GDB/MI Target Manipulation, Prev: GDB/MI Symbol Query, Up: GDB/MI 27.19 GDB/MI File Commands ========================== This section describes the GDB/MI commands to specify executable file names and to read in and obtain symbol table information. The `-file-exec-and-symbols' Command ------------------------------------ Synopsis ........ -file-exec-and-symbols FILE Specify the executable file to be debugged. This file is the one from which the symbol table is also read. If no file is specified, the command clears the executable and symbol information. If breakpoints are set when using this command with no arguments, GDB will produce error messages. Otherwise, no output is produced, except a completion notification. GDB Command ........... The corresponding GDB command is `file'. Example ....... (gdb) -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx ^done (gdb) The `-file-exec-file' Command ----------------------------- Synopsis ........ -file-exec-file FILE Specify the executable file to be debugged. Unlike `-file-exec-and-symbols', the symbol table is _not_ read from this file. If used without argument, GDB clears the information about the executable file. No output is produced, except a completion notification. GDB Command ........... The corresponding GDB command is `exec-file'. Example ....... (gdb) -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx ^done (gdb) The `-file-list-exec-source-file' Command ----------------------------------------- Synopsis ........ -file-list-exec-source-file List the line number, the current source file, and the absolute path to the current source file for the current executable. The macro information field has a value of `1' or `0' depending on whether or not the file includes preprocessor macro information. GDB Command ........... The GDB equivalent is `info source' Example ....... (gdb) 123-file-list-exec-source-file 123^done,line="1",file="foo.c",fullname="/home/bar/foo.c,macro-info="1" (gdb) The `-file-list-exec-source-files' Command ------------------------------------------ Synopsis ........ -file-list-exec-source-files [ -GROUP-BY-OBJFILE ] [ -DIRNAME | -BASENAME ] [ -- ] [ REGEXP ] This command returns information about the source files GDB knows about, it will output both the filename and fullname (absolute file name) of a source file, though the fullname can be elided if this information is not known to GDB. With no arguments this command returns a list of source files. Each source file is represented by a tuple with the fields; FILE, FULLNAME, and DEBUG-FULLY-READ. The FILE is the display name for the file, while FULLNAME is the absolute name of the file. The FULLNAME field can be elided if the absolute name of the source file can't be computed. The field DEBUG-FULLY-READ will be a string, either `true' or `false'. When `true', this indicates the full debug information for the compilation unit describing this file has been read in. When `false', the full debug information has not yet been read in. While reading in the full debug information it is possible that GDB could become aware of additional source files. The optional REGEXP can be used to filter the list of source files returned. The REGEXP will be matched against the full source file name. The matching is case-sensitive, except on operating systems that have case-insensitive filesystem (e.g., MS-Windows). `--' can be used before REGEXP to prevent GDB interpreting REGEXP as a command option (e.g. if REGEXP starts with `-'). If `--dirname' is provided, then REGEXP is matched only against the directory name of each source file. If `--basename' is provided, then REGEXP is matched against the basename of each source file. Only one of `--dirname' or `--basename' may be given, and if either is given then REGEXP is required. If `--group-by-objfile' is used then the format of the results is changed. The results will now be a list of tuples, with each tuple representing an object file (executable or shared library) loaded into GDB. The fields of these tuples are; FILENAME, DEBUG-INFO, and SOURCES. The FILENAME is the absolute name of the object file, DEBUG-INFO is a string with one of the following values: `none' This object file has no debug information. `partially-read' This object file has debug information, but it is not fully read in yet. When it is read in later, GDB might become aware of additional source files. `fully-read' This object file has debug information, and this information is fully read into GDB. The list of source files is complete. The SOURCES is a list or tuples, with each tuple describing a single source file with the same fields as described previously. The SOURCES list can be empty for object files that have no debug information. GDB Command ........... The GDB equivalent is `info sources'. `gdbtk' has an analogous command `gdb_listfiles'. Example ....... (gdb) -file-list-exec-source-files ^done,files=[{file="foo.c",fullname="/home/foo.c",debug-fully-read="true"}, {file="/home/bar.c",fullname="/home/bar.c",debug-fully-read="true"}, {file="gdb_could_not_find_fullpath.c",debug-fully-read="true"}] (gdb) -file-list-exec-source-files ^done,files=[{file="test.c", fullname="/tmp/info-sources/test.c", debug-fully-read="true"}, {file="/usr/include/stdc-predef.h", fullname="/usr/include/stdc-predef.h", debug-fully-read="true"}, {file="header.h", fullname="/tmp/info-sources/header.h", debug-fully-read="true"}, {file="helper.c", fullname="/tmp/info-sources/helper.c", debug-fully-read="true"}] (gdb) -file-list-exec-source-files -- \\.c ^done,files=[{file="test.c", fullname="/tmp/info-sources/test.c", debug-fully-read="true"}, {file="helper.c", fullname="/tmp/info-sources/helper.c", debug-fully-read="true"}] (gdb) -file-list-exec-source-files --group-by-objfile ^done,files=[{filename="/tmp/info-sources/test.x", debug-info="fully-read", sources=[{file="test.c", fullname="/tmp/info-sources/test.c", debug-fully-read="true"}, {file="/usr/include/stdc-predef.h", fullname="/usr/include/stdc-predef.h", debug-fully-read="true"}, {file="header.h", fullname="/tmp/info-sources/header.h", debug-fully-read="true"}]}, {filename="/lib64/ld-linux-x86-64.so.2", debug-info="none", sources=[]}, {filename="system-supplied DSO at 0x7ffff7fcf000", debug-info="none", sources=[]}, {filename="/tmp/info-sources/libhelper.so", debug-info="fully-read", sources=[{file="helper.c", fullname="/tmp/info-sources/helper.c", debug-fully-read="true"}, {file="/usr/include/stdc-predef.h", fullname="/usr/include/stdc-predef.h", debug-fully-read="true"}, {file="header.h", fullname="/tmp/info-sources/header.h", debug-fully-read="true"}]}, {filename="/lib64/libc.so.6", debug-info="none", sources=[]}] The `-file-list-shared-libraries' Command ----------------------------------------- Synopsis ........ -file-list-shared-libraries [ REGEXP ] List the shared libraries in the program. With a regular expression REGEXP, only those libraries whose names match REGEXP are listed. GDB Command ........... The corresponding GDB command is `info shared'. The fields have a similar meaning to the `=library-loaded' notification. The `ranges' field specifies the multiple segments belonging to this library. Each range has the following fields: `from' The address defining the inclusive lower bound of the segment. `to' The address defining the exclusive upper bound of the segment. Example ....... (gdb) -file-list-exec-source-files ^done,shared-libraries=[ {id="/lib/libfoo.so",target-name="/lib/libfoo.so",host-name="/lib/libfoo.so",symbols-loaded="1",thread-group="i1",ranges=[{from="0x72815989",to="0x728162c0"}]}, {id="/lib/libbar.so",target-name="/lib/libbar.so",host-name="/lib/libbar.so",symbols-loaded="1",thread-group="i1",ranges=[{from="0x76ee48c0",to="0x76ee9160"}]}] (gdb) The `-file-symbol-file' Command ------------------------------- Synopsis ........ -file-symbol-file FILE Read symbol table info from the specified FILE argument. When used without arguments, clears GDB's symbol table info. No output is produced, except for a completion notification. GDB Command ........... The corresponding GDB command is `symbol-file'. Example ....... (gdb) -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx ^done (gdb)  File: gdb.info, Node: GDB/MI Target Manipulation, Next: GDB/MI File Transfer Commands, Prev: GDB/MI File Commands, Up: GDB/MI 27.20 GDB/MI Target Manipulation Commands ========================================= The `-target-attach' Command ---------------------------- Synopsis ........ -target-attach PID | GID | FILE Attach to a process PID or a file FILE outside of GDB, or a thread group GID. If attaching to a thread group, the id previously returned by `-list-thread-groups --available' must be used. GDB Command ........... The corresponding GDB command is `attach'. Example ....... (gdb) -target-attach 34 =thread-created,id="1" *stopped,thread-id="1",frame={addr="0xb7f7e410",func="bar",args=[]} ^done (gdb) The `-target-detach' Command ---------------------------- Synopsis ........ -target-detach [ PID | GID ] Detach from the remote target which normally resumes its execution. If either PID or GID is specified, detaches from either the specified process, or specified thread group. There's no output. GDB Command ........... The corresponding GDB command is `detach'. Example ....... (gdb) -target-detach ^done (gdb) The `-target-disconnect' Command -------------------------------- Synopsis ........ -target-disconnect Disconnect from the remote target. There's no output and the target is generally not resumed. GDB Command ........... The corresponding GDB command is `disconnect'. Example ....... (gdb) -target-disconnect ^done (gdb) The `-target-download' Command ------------------------------ Synopsis ........ -target-download Loads the executable onto the remote target. It prints out an update message every half second, which includes the fields: `section' The name of the section. `section-sent' The size of what has been sent so far for that section. `section-size' The size of the section. `total-sent' The total size of what was sent so far (the current and the previous sections). `total-size' The size of the overall executable to download. Each message is sent as status record (*note GDB/MI Output Syntax: GDB/MI Output Syntax.). In addition, it prints the name and size of the sections, as they are downloaded. These messages include the following fields: `section' The name of the section. `section-size' The size of the section. `total-size' The size of the overall executable to download. At the end, a summary is printed. GDB Command ........... The corresponding GDB command is `load'. Example ....... Note: each status message appears on a single line. Here the messages have been broken down so that they can fit onto a page. (gdb) -target-download +download,{section=".text",section-size="6668",total-size="9880"} +download,{section=".text",section-sent="512",section-size="6668", total-sent="512",total-size="9880"} +download,{section=".text",section-sent="1024",section-size="6668", total-sent="1024",total-size="9880"} +download,{section=".text",section-sent="1536",section-size="6668", total-sent="1536",total-size="9880"} +download,{section=".text",section-sent="2048",section-size="6668", total-sent="2048",total-size="9880"} +download,{section=".text",section-sent="2560",section-size="6668", total-sent="2560",total-size="9880"} +download,{section=".text",section-sent="3072",section-size="6668", total-sent="3072",total-size="9880"} +download,{section=".text",section-sent="3584",section-size="6668", total-sent="3584",total-size="9880"} +download,{section=".text",section-sent="4096",section-size="6668", total-sent="4096",total-size="9880"} +download,{section=".text",section-sent="4608",section-size="6668", total-sent="4608",total-size="9880"} +download,{section=".text",section-sent="5120",section-size="6668", total-sent="5120",total-size="9880"} +download,{section=".text",section-sent="5632",section-size="6668", total-sent="5632",total-size="9880"} +download,{section=".text",section-sent="6144",section-size="6668", total-sent="6144",total-size="9880"} +download,{section=".text",section-sent="6656",section-size="6668", total-sent="6656",total-size="9880"} +download,{section=".init",section-size="28",total-size="9880"} +download,{section=".fini",section-size="28",total-size="9880"} +download,{section=".data",section-size="3156",total-size="9880"} +download,{section=".data",section-sent="512",section-size="3156", total-sent="7236",total-size="9880"} +download,{section=".data",section-sent="1024",section-size="3156", total-sent="7748",total-size="9880"} +download,{section=".data",section-sent="1536",section-size="3156", total-sent="8260",total-size="9880"} +download,{section=".data",section-sent="2048",section-size="3156", total-sent="8772",total-size="9880"} +download,{section=".data",section-sent="2560",section-size="3156", total-sent="9284",total-size="9880"} +download,{section=".data",section-sent="3072",section-size="3156", total-sent="9796",total-size="9880"} ^done,address="0x10004",load-size="9880",transfer-rate="6586", write-rate="429" (gdb) GDB Command ........... No equivalent. Example ....... N.A. The `-target-flash-erase' Command --------------------------------- Synopsis ........ -target-flash-erase Erases all known flash memory regions on the target. The corresponding GDB command is `flash-erase'. The output is a list of flash regions that have been erased, with starting addresses and memory region sizes. (gdb) -target-flash-erase ^done,erased-regions={address="0x0",size="0x40000"} (gdb) The `-target-select' Command ---------------------------- Synopsis ........ -target-select TYPE PARAMETERS ... Connect GDB to the remote target. This command takes two args: `TYPE' The type of target, for instance `remote', etc. `PARAMETERS' Device names, host names and the like. *Note Commands for Managing Targets: Target Commands, for more details. The output is a connection notification, followed by the address at which the target program is, in the following form: ^connected,addr="ADDRESS",func="FUNCTION NAME", args=[ARG LIST] GDB Command ........... The corresponding GDB command is `target'. Example ....... (gdb) -target-select remote /dev/ttya ^connected,addr="0xfe00a300",func="??",args=[] (gdb)  File: gdb.info, Node: GDB/MI File Transfer Commands, Next: GDB/MI Ada Exceptions Commands, Prev: GDB/MI Target Manipulation, Up: GDB/MI 27.21 GDB/MI File Transfer Commands =================================== The `-target-file-put' Command ------------------------------ Synopsis ........ -target-file-put HOSTFILE TARGETFILE Copy file HOSTFILE from the host system (the machine running GDB) to TARGETFILE on the target system. GDB Command ........... The corresponding GDB command is `remote put'. Example ....... (gdb) -target-file-put localfile remotefile ^done (gdb) The `-target-file-get' Command ------------------------------ Synopsis ........ -target-file-get TARGETFILE HOSTFILE Copy file TARGETFILE from the target system to HOSTFILE on the host system. GDB Command ........... The corresponding GDB command is `remote get'. Example ....... (gdb) -target-file-get remotefile localfile ^done (gdb) The `-target-file-delete' Command --------------------------------- Synopsis ........ -target-file-delete TARGETFILE Delete TARGETFILE from the target system. GDB Command ........... The corresponding GDB command is `remote delete'. Example ....... (gdb) -target-file-delete remotefile ^done (gdb)  File: gdb.info, Node: GDB/MI Ada Exceptions Commands, Next: GDB/MI Support Commands, Prev: GDB/MI File Transfer Commands, Up: GDB/MI 27.22 Ada Exceptions GDB/MI Commands ==================================== The `-info-ada-exceptions' Command ---------------------------------- Synopsis ........ -info-ada-exceptions [ REGEXP] List all Ada exceptions defined within the program being debugged. With a regular expression REGEXP, only those exceptions whose names match REGEXP are listed. GDB Command ........... The corresponding GDB command is `info exceptions'. Result ...... The result is a table of Ada exceptions. The following columns are defined for each exception: `name' The name of the exception. `address' The address of the exception. Example ....... -info-ada-exceptions aint ^done,ada-exceptions={nr_rows="2",nr_cols="2", hdr=[{width="1",alignment="-1",col_name="name",colhdr="Name"}, {width="1",alignment="-1",col_name="address",colhdr="Address"}], body=[{name="constraint_error",address="0x0000000000613da0"}, {name="const.aint_global_e",address="0x0000000000613b00"}]} Catching Ada Exceptions ----------------------- The commands describing how to ask GDB to stop when a program raises an exception are described at *Note Ada Exception GDB/MI Catchpoint Commands::.  File: gdb.info, Node: GDB/MI Support Commands, Next: GDB/MI Miscellaneous Commands, Prev: GDB/MI Ada Exceptions Commands, Up: GDB/MI 27.23 GDB/MI Support Commands ============================= Since new commands and features get regularly added to GDB/MI, some commands are available to help front-ends query the debugger about support for these capabilities. Similarly, it is also possible to query GDB about target support of certain features. The `-info-gdb-mi-command' Command ---------------------------------- Synopsis ........ -info-gdb-mi-command CMD_NAME Query support for the GDB/MI command named CMD_NAME. Note that the dash (`-') starting all GDB/MI commands is technically not part of the command name (*note GDB/MI Input Syntax::), and thus should be omitted in CMD_NAME. However, for ease of use, this command also accepts the form with the leading dash. GDB Command ........... There is no corresponding GDB command. Result ...... The result is a tuple. There is currently only one field: `exists' This field is equal to `"true"' if the GDB/MI command exists, `"false"' otherwise. Example ....... Here is an example where the GDB/MI command does not exist: -info-gdb-mi-command unsupported-command ^done,command={exists="false"} And here is an example where the GDB/MI command is known to the debugger: -info-gdb-mi-command symbol-list-lines ^done,command={exists="true"} The `-list-features' Command ---------------------------- Returns a list of particular features of the MI protocol that this version of gdb implements. A feature can be a command, or a new field in an output of some command, or even an important bugfix. While a frontend can sometimes detect presence of a feature at runtime, it is easier to perform detection at debugger startup. The command returns a list of strings, with each string naming an available feature. Each returned string is just a name, it does not have any internal structure. The list of possible feature names is given below. Example output: (gdb) -list-features ^done,result=["feature1","feature2"] The current list of features is: `frozen-varobjs' Indicates support for the `-var-set-frozen' command, as well as possible presence of the `frozen' field in the output of `-varobj-create'. `pending-breakpoints' Indicates support for the `-f' option to the `-break-insert' command. `python' Indicates Python scripting support, Python-based pretty-printing commands, and possible presence of the `display_hint' field in the output of `-var-list-children' `thread-info' Indicates support for the `-thread-info' command. `data-read-memory-bytes' Indicates support for the `-data-read-memory-bytes' and the `-data-write-memory-bytes' commands. `breakpoint-notifications' Indicates that changes to breakpoints and breakpoints created via the CLI will be announced via async records. `ada-task-info' Indicates support for the `-ada-task-info' command. `language-option' Indicates that all GDB/MI commands accept the `--language' option (*note Context management::). `info-gdb-mi-command' Indicates support for the `-info-gdb-mi-command' command. `undefined-command-error-code' Indicates support for the "undefined-command" error code in error result records, produced when trying to execute an undefined GDB/MI command (*note GDB/MI Result Records::). `exec-run-start-option' Indicates that the `-exec-run' command supports the `--start' option (*note GDB/MI Program Execution::). `data-disassemble-a-option' Indicates that the `-data-disassemble' command supports the `-a' option (*note GDB/MI Data Manipulation::). `simple-values-ref-types' Indicates that the `--simple-values' argument to the `-stack-list-arguments', `-stack-list-locals', `-stack-list-variables', and `-var-list-children' commands takes reference types into account: that is, a value is considered simple if it is neither an array, structure, or union, nor a reference to an array, structure, or union. The `-list-target-features' Command ----------------------------------- Returns a list of particular features that are supported by the target. Those features affect the permitted MI commands, but unlike the features reported by the `-list-features' command, the features depend on which target GDB is using at the moment. Whenever a target can change, due to commands such as `-target-select', `-target-attach' or `-exec-run', the list of target features may change, and the frontend should obtain it again. Example output: (gdb) -list-target-features ^done,result=["async"] The current list of features is: `async' Indicates that the target is capable of asynchronous command execution, which means that GDB will accept further commands while the target is running. `reverse' Indicates that the target is capable of reverse execution. *Note Reverse Execution::, for more information.  File: gdb.info, Node: GDB/MI Miscellaneous Commands, Prev: GDB/MI Support Commands, Up: GDB/MI 27.24 Miscellaneous GDB/MI Commands =================================== The `-gdb-exit' Command ----------------------- Synopsis ........ -gdb-exit Exit GDB immediately. GDB Command ........... Approximately corresponds to `quit'. Example ....... (gdb) -gdb-exit ^exit The `-gdb-set' Command ---------------------- Synopsis ........ -gdb-set Set an internal GDB variable. GDB Command ........... The corresponding GDB command is `set'. Example ....... (gdb) -gdb-set $foo=3 ^done (gdb) The `-gdb-show' Command ----------------------- Synopsis ........ -gdb-show Show the current value of a GDB variable. GDB Command ........... The corresponding GDB command is `show'. Example ....... (gdb) -gdb-show annotate ^done,value="0" (gdb) The `-gdb-version' Command -------------------------- Synopsis ........ -gdb-version Show version information for GDB. Used mostly in testing. GDB Command ........... The GDB equivalent is `show version'. GDB by default shows this information when you start an interactive session. Example ....... (gdb) -gdb-version ~GNU gdb 5.2.1 ~Copyright 2000 Free Software Foundation, Inc. ~GDB is free software, covered by the GNU General Public License, and ~you are welcome to change it and/or distribute copies of it under ~ certain conditions. ~Type "show copying" to see the conditions. ~There is absolutely no warranty for GDB. Type "show warranty" for ~ details. ~This GDB was configured as "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". ^done (gdb) The `-list-thread-groups' Command --------------------------------- Synopsis ........ -list-thread-groups [ --available ] [ --recurse 1 ] [ GROUP ... ] Lists thread groups (*note Thread groups::). When a single thread group is passed as the argument, lists the children of that group. When several thread group are passed, lists information about those thread groups. Without any parameters, lists information about all top-level thread groups. Normally, thread groups that are being debugged are reported. With the `--available' option, GDB reports thread groups available on the target. The output of this command may have either a `threads' result or a `groups' result. The `thread' result has a list of tuples as value, with each tuple describing a thread (*note GDB/MI Thread Information::). The `groups' result has a list of tuples as value, each tuple describing a thread group. If top-level groups are requested (that is, no parameter is passed), or when several groups are passed, the output always has a `groups' result. The format of the `group' result is described below. To reduce the number of roundtrips it's possible to list thread groups together with their children, by passing the `--recurse' option and the recursion depth. Presently, only recursion depth of 1 is permitted. If this option is present, then every reported thread group will also include its children, either as `group' or `threads' field. In general, any combination of option and parameters is permitted, with the following caveats: * When a single thread group is passed, the output will typically be the `threads' result. Because threads may not contain anything, the `recurse' option will be ignored. * When the `--available' option is passed, limited information may be available. In particular, the list of threads of a process might be inaccessible. Further, specifying specific thread groups might not give any performance advantage over listing all thread groups. The frontend should assume that `-list-thread-groups --available' is always an expensive operation and cache the results. The `groups' result is a list of tuples, where each tuple may have the following fields: `id' Identifier of the thread group. This field is always present. The identifier is an opaque string; frontends should not try to convert it to an integer, even though it might look like one. `type' The type of the thread group. At present, only `process' is a valid type. `pid' The target-specific process identifier. This field is only present for thread groups of type `process' and only if the process exists. `exit-code' The exit code of this group's last exited thread, formatted in octal. This field is only present for thread groups of type `process' and only if the process is not running. `num_children' The number of children this thread group has. This field may be absent for an available thread group. `threads' This field has a list of tuples as value, each tuple describing a thread. It may be present if the `--recurse' option is specified, and it's actually possible to obtain the threads. `cores' This field is a list of integers, each identifying a core that one thread of the group is running on. This field may be absent if such information is not available. `executable' The name of the executable file that corresponds to this thread group. The field is only present for thread groups of type `process', and only if there is a corresponding executable file. Example ....... (gdb) -list-thread-groups ^done,groups=[{id="17",type="process",pid="yyy",num_children="2"}] -list-thread-groups 17 ^done,threads=[{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)", frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]},state="running"}, {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)", frame={level="0",addr="0x0804891f",func="foo",args=[{name="i",value="10"}], file="/tmp/a.c",fullname="/tmp/a.c",line="158",arch="i386:x86_64"},state="running"}]] -list-thread-groups --available ^done,groups=[{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]}] -list-thread-groups --available --recurse 1 ^done,groups=[{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], threads=[{id="1",target-id="Thread 0xb7e14b90",cores=[1]}, {id="2",target-id="Thread 0xb7e14b90",cores=[2]}]},..] -list-thread-groups --available --recurse 1 17 18 ^done,groups=[{id="17", types="process",pid="yyy",num_children="2",cores=[1,2], threads=[{id="1",target-id="Thread 0xb7e14b90",cores=[1]}, {id="2",target-id="Thread 0xb7e14b90",cores=[2]}]},...] The `-info-os' Command ---------------------- Synopsis ........ -info-os [ TYPE ] If no argument is supplied, the command returns a table of available operating-system-specific information types. If one of these types is supplied as an argument TYPE, then the command returns a table of data of that type. The types of information available depend on the target operating system. GDB Command ........... The corresponding GDB command is `info os'. Example ....... When run on a GNU/Linux system, the output will look something like this: (gdb) -info-os ^done,OSDataTable={nr_rows="10",nr_cols="3", hdr=[{width="10",alignment="-1",col_name="col0",colhdr="Type"}, {width="10",alignment="-1",col_name="col1",colhdr="Description"}, {width="10",alignment="-1",col_name="col2",colhdr="Title"}], body=[item={col0="cpus",col1="Listing of all cpus/cores on the system", col2="CPUs"}, item={col0="files",col1="Listing of all file descriptors", col2="File descriptors"}, item={col0="modules",col1="Listing of all loaded kernel modules", col2="Kernel modules"}, item={col0="msg",col1="Listing of all message queues", col2="Message queues"}, item={col0="processes",col1="Listing of all processes", col2="Processes"}, item={col0="procgroups",col1="Listing of all process groups", col2="Process groups"}, item={col0="semaphores",col1="Listing of all semaphores", col2="Semaphores"}, item={col0="shm",col1="Listing of all shared-memory regions", col2="Shared-memory regions"}, item={col0="sockets",col1="Listing of all internet-domain sockets", col2="Sockets"}, item={col0="threads",col1="Listing of all threads", col2="Threads"}] (gdb) -info-os processes ^done,OSDataTable={nr_rows="190",nr_cols="4", hdr=[{width="10",alignment="-1",col_name="col0",colhdr="pid"}, {width="10",alignment="-1",col_name="col1",colhdr="user"}, {width="10",alignment="-1",col_name="col2",colhdr="command"}, {width="10",alignment="-1",col_name="col3",colhdr="cores"}], body=[item={col0="1",col1="root",col2="/sbin/init",col3="0"}, item={col0="2",col1="root",col2="[kthreadd]",col3="1"}, item={col0="3",col1="root",col2="[ksoftirqd/0]",col3="0"}, ... item={col0="26446",col1="stan",col2="bash",col3="0"}, item={col0="28152",col1="stan",col2="bash",col3="1"}]} (gdb) (Note that the MI output here includes a `"Title"' column that does not appear in command-line `info os'; this column is useful for MI clients that want to enumerate the types of data, such as in a popup menu, but is needless clutter on the command line, and `info os' omits it.) The `-add-inferior' Command --------------------------- Synopsis ........ -add-inferior [ --no-connection ] Creates a new inferior (*note Inferiors Connections and Programs::). The created inferior is not associated with any executable. Such association may be established with the `-file-exec-and-symbols' command (*note GDB/MI File Commands::). By default, the new inferior begins connected to the same target connection as the current inferior. For example, if the current inferior was connected to `gdbserver' with `target remote', then the new inferior will be connected to the same `gdbserver' instance. The `--no-connection' option starts the new inferior with no connection yet. You can then for example use the `-target-select remote' command to connect to some other `gdbserver' instance, use `-exec-run' to spawn a local program, etc. The command response always has a field, INFERIOR, whose value is the identifier of the thread group corresponding to the new inferior. An additional section field, CONNECTION, is optional. This field will only exist if the new inferior has a target connection. If this field exists, then its value will be a tuple containing the following fields: `number' The number of the connection used for the new inferior. `name' The name of the connection type used for the new inferior. GDB Command ........... The corresponding GDB command is `add-inferior' (*note `add-inferior': add_inferior_cli.). Example ....... (gdb) -add-inferior ^done,inferior="i3" The `-remove-inferior' Command ------------------------------ Synopsis ........ -remove-inferior INFERIOR-ID Removes an inferior (*note Inferiors Connections and Programs::). Only inferiors that have exited can be removed. The INFERIOR-ID is the inferior to be removed, and should be the same id string as returned by the `-add-inferior' command. When an inferior is successfully removed a `=thread-group-removed' notification (*note GDB/MI Async Records::) is emitted, the ID field of which contains the INFERIOR-ID for the removed inferior. GDB Command ........... The corresponding GDB command is `remove-inferiors' (*note `remove-inferiors': remove_inferiors_cli.). Example ....... (gdb) -remove-inferior i3 =thread-group-removed,id="i3" ^done The `-interpreter-exec' Command ------------------------------- Synopsis ........ -interpreter-exec INTERPRETER COMMAND Execute the specified COMMAND in the given INTERPRETER. GDB Command ........... The corresponding GDB command is `interpreter-exec'. Example ....... (gdb) -interpreter-exec console "break main" &"During symbol reading, couldn't parse type; debugger out of date?.\n" &"During symbol reading, bad structure-type format.\n" ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n" ^done (gdb) The `-inferior-tty-set' Command ------------------------------- Synopsis ........ -inferior-tty-set /dev/pts/1 Set terminal for future runs of the program being debugged. GDB Command ........... The corresponding GDB command is `set inferior-tty' /dev/pts/1. Example ....... (gdb) -inferior-tty-set /dev/pts/1 ^done (gdb) The `-inferior-tty-show' Command -------------------------------- Synopsis ........ -inferior-tty-show Show terminal for future runs of program being debugged. GDB Command ........... The corresponding GDB command is `show inferior-tty'. Example ....... (gdb) -inferior-tty-set /dev/pts/1 ^done (gdb) -inferior-tty-show ^done,inferior_tty_terminal="/dev/pts/1" (gdb) The `-enable-timings' Command ----------------------------- Synopsis ........ -enable-timings [yes | no] Toggle the printing of the wallclock, user and system times for an MI command as a field in its output. This command is to help frontend developers optimize the performance of their code. No argument is equivalent to `yes'. GDB Command ........... No equivalent. Example ....... (gdb) -enable-timings ^done (gdb) -break-insert main ^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y", addr="0x080484ed",func="main",file="myprog.c", fullname="/home/nickrob/myprog.c",line="73",thread-groups=["i1"], times="0"}, time={wallclock="0.05185",user="0.00800",system="0.00000"} (gdb) -enable-timings no ^done (gdb) -exec-run ^running (gdb) *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0", frame={addr="0x080484ed",func="main",args=[{name="argc",value="1"}, {name="argv",value="0xbfb60364"}],file="myprog.c", fullname="/home/nickrob/myprog.c",line="73",arch="i386:x86_64"} (gdb) The `-complete' Command ----------------------- Synopsis ........ -complete COMMAND Show a list of completions for partially typed CLI COMMAND. This command is intended for GDB/MI frontends that cannot use two separate CLI and MI channels -- for example: because of lack of PTYs like on Windows or because GDB is used remotely via a SSH connection. Result ...... The result consists of two or three fields: `completion' This field contains the completed COMMAND. If COMMAND has no known completions, this field is omitted. `matches' This field contains a (possibly empty) array of matches. It is always present. `max_completions_reached' This field contains `1' if number of known completions is above `max-completions' limit (*note Completion::), otherwise it contains `0'. It is always present. GDB Command ........... The corresponding GDB command is `complete'. Example ....... (gdb) -complete br ^done,completion="break", matches=["break","break-range"], max_completions_reached="0" (gdb) -complete "b ma" ^done,completion="b ma", matches=["b madvise","b main"],max_completions_reached="0" (gdb) -complete "b push_b" ^done,completion="b push_back(", matches=[ "b A::push_back(void*)", "b std::string::push_back(char)", "b std::vector >::push_back(int&&)"], max_completions_reached="0" (gdb) -complete "nonexist" ^done,matches=[],max_completions_reached="0" (gdb)  File: gdb.info, Node: Annotations, Next: Debugger Adapter Protocol, Prev: GDB/MI, Up: Top 28 GDB Annotations ****************** This chapter describes annotations in GDB. Annotations were designed to interface GDB to graphical user interfaces or other similar programs which want to interact with GDB at a relatively high level. The annotation mechanism has largely been superseded by GDB/MI (*note GDB/MI::). * Menu: * Annotations Overview:: What annotations are; the general syntax. * Server Prefix:: Issuing a command without affecting user state. * Prompting:: Annotations marking GDB's need for input. * Errors:: Annotations for error messages. * Invalidation:: Some annotations describe things now invalid. * Annotations for Running:: Whether the program is running, how it stopped, etc. * Source Annotations:: Annotations describing source code.  File: gdb.info, Node: Annotations Overview, Next: Server Prefix, Up: Annotations 28.1 What is an Annotation? =========================== Annotations start with a newline character, two `control-z' characters, and the name of the annotation. If there is no additional information associated with this annotation, the name of the annotation is followed immediately by a newline. If there is additional information, the name of the annotation is followed by a space, the additional information, and a newline. The additional information cannot contain newline characters. Any output not beginning with a newline and two `control-z' characters denotes literal output from GDB. Currently there is no need for GDB to output a newline followed by two `control-z' characters, but if there was such a need, the annotations could be extended with an `escape' annotation which means those three characters as output. The annotation LEVEL, which is specified using the `--annotate' command line option (*note Mode Options::), controls how much information GDB prints together with its prompt, values of expressions, source lines, and other types of output. Level 0 is for no annotations, level 1 is for use when GDB is run as a subprocess of GNU Emacs, level 3 is the maximum annotation suitable for programs that control GDB, and level 2 annotations have been made obsolete (*note Limitations of the Annotation Interface: (annotate)Limitations.). `set annotate LEVEL' The GDB command `set annotate' sets the level of annotations to the specified LEVEL. `show annotate' Show the current annotation level. This chapter describes level 3 annotations. A simple example of starting up GDB with annotations is: $ gdb --annotate=3 GNU gdb 6.0 Copyright 2003 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-pc-linux-gnu" ^Z^Zpre-prompt (gdb) ^Z^Zprompt quit ^Z^Zpost-prompt $ Here `quit' is input to GDB; the rest is output from GDB. The three lines beginning `^Z^Z' (where `^Z' denotes a `control-z' character) are annotations; the rest is output from GDB.  File: gdb.info, Node: Server Prefix, Next: Prompting, Prev: Annotations Overview, Up: Annotations 28.2 The Server Prefix ====================== If you prefix a command with `server ' then it will not affect the command history, nor will it affect GDB's notion of which command to repeat if is pressed on a line by itself. This means that commands can be run behind a user's back by a front-end in a transparent manner. The `server ' prefix does not affect the recording of values into the value history; to print a value without recording it into the value history, use the `output' command instead of the `print' command. Using this prefix also disables confirmation requests (*note confirmation requests::).  File: gdb.info, Node: Prompting, Next: Errors, Prev: Server Prefix, Up: Annotations 28.3 Annotation for GDB Input ============================= When GDB prompts for input, it annotates this fact so it is possible to know when to send output, when the output from a given command is over, etc. Different kinds of input each have a different "input type". Each input type has three annotations: a `pre-' annotation, which denotes the beginning of any prompt which is being output, a plain annotation, which denotes the end of the prompt, and then a `post-' annotation which denotes the end of any echo which may (or may not) be associated with the input. For example, the `prompt' input type features the following annotations: ^Z^Zpre-prompt ^Z^Zprompt ^Z^Zpost-prompt The input types are `prompt' When GDB is prompting for a command (the main GDB prompt). `commands' When GDB prompts for a set of commands, like in the `commands' command. The annotations are repeated for each command which is input. `overload-choice' When GDB wants the user to select between various overloaded functions. `query' When GDB wants the user to confirm a potentially dangerous operation. `prompt-for-continue' When GDB is asking the user to press return to continue. Note: Don't expect this to work well; instead use `set height 0' to disable prompting. This is because the counting of lines is buggy in the presence of annotations.  File: gdb.info, Node: Errors, Next: Invalidation, Prev: Prompting, Up: Annotations 28.4 Errors =========== ^Z^Zquit This annotation occurs right before GDB responds to an interrupt. ^Z^Zerror This annotation occurs right before GDB responds to an error. Quit and error annotations indicate that any annotations which GDB was in the middle of may end abruptly. For example, if a `value-history-begin' annotation is followed by a `error', one cannot expect to receive the matching `value-history-end'. One cannot expect not to receive it either, however; an error annotation does not necessarily mean that GDB is immediately returning all the way to the top level. A quit or error annotation may be preceded by ^Z^Zerror-begin Any output between that and the quit or error annotation is the error message. Warning messages are not yet annotated.  File: gdb.info, Node: Invalidation, Next: Annotations for Running, Prev: Errors, Up: Annotations 28.5 Invalidation Notices ========================= The following annotations say that certain pieces of state may have changed. `^Z^Zframes-invalid' The frames (for example, output from the `backtrace' command) may have changed. `^Z^Zbreakpoints-invalid' The breakpoints may have changed. For example, the user just added or deleted a breakpoint.  File: gdb.info, Node: Annotations for Running, Next: Source Annotations, Prev: Invalidation, Up: Annotations 28.6 Running the Program ======================== When the program starts executing due to a GDB command such as `step' or `continue', ^Z^Zstarting is output. When the program stops, ^Z^Zstopped is output. Before the `stopped' annotation, a variety of annotations describe how the program stopped. `^Z^Zexited EXIT-STATUS' The program exited, and EXIT-STATUS is the exit status (zero for successful exit, otherwise nonzero). `^Z^Zsignalled' The program exited with a signal. After the `^Z^Zsignalled', the annotation continues: INTRO-TEXT ^Z^Zsignal-name NAME ^Z^Zsignal-name-end MIDDLE-TEXT ^Z^Zsignal-string STRING ^Z^Zsignal-string-end END-TEXT where NAME is the name of the signal, such as `SIGILL' or `SIGSEGV', and STRING is the explanation of the signal, such as `Illegal Instruction' or `Segmentation fault'. The arguments INTRO-TEXT, MIDDLE-TEXT, and END-TEXT are for the user's benefit and have no particular format. `^Z^Zsignal' The syntax of this annotation is just like `signalled', but GDB is just saying that the program received the signal, not that it was terminated with it. `^Z^Zbreakpoint NUMBER' The program hit breakpoint number NUMBER. `^Z^Zwatchpoint NUMBER' The program hit watchpoint number NUMBER.  File: gdb.info, Node: Source Annotations, Prev: Annotations for Running, Up: Annotations 28.7 Displaying Source ====================== The following annotation is used instead of displaying source code: ^Z^Zsource FILENAME:LINE:CHARACTER:MIDDLE:ADDR where FILENAME is an absolute file name indicating which source file, LINE is the line number within that file (where 1 is the first line in the file), CHARACTER is the character position within the file (where 0 is the first character in the file) (for most debug formats this will necessarily point to the beginning of a line), MIDDLE is `middle' if ADDR is in the middle of the line, or `beg' if ADDR is at the beginning of the line, and ADDR is the address in the target program associated with the source which is being displayed. The ADDR is in the form `0x' followed by one or more lowercase hex digits (note that this does not depend on the language).  File: gdb.info, Node: Debugger Adapter Protocol, Next: JIT Interface, Prev: Annotations, Up: Top 29 Debugger Adapter Protocol **************************** The Debugger Adapter Protocol is a generic API that is used by some IDEs to communicate with debuggers. It is documented at `https://microsoft.github.io/debug-adapter-protocol/'. Generally, GDB implements the Debugger Adapter Protocol as written. However, in some cases, extensions are either needed or even expected. GDB defines some parameters that can be passed to the `launch' request: `args' If provided, this should be an array of strings. These strings are provided as command-line arguments to the inferior, as if by `set args'. *Note Arguments::. `cwd' If provided, this should be a string. GDB will change its working directory to this directory, as if by the `cd' command (*note Working Directory::). The launched program will inherit this as its working directory. Note that change of directory happens before the `program' parameter is processed. This will affect the result if `program' is a relative filename. `env' If provided, this should be an object. Each key of the object will be used as the name of an environment variable; each value must be a string and will be the value of that variable. The environment of the inferior will be set to exactly as passed in. *Note Environment::. `program' If provided, this is a string that specifies the program to use. This corresponds to the `file' command. *Note Files::. `stopAtBeginningOfMainSubprogram' If provided, this must be a boolean. When `True', GDB will set a temporary breakpoint at the program's main procedure, using the same approach as the `start' command. *Note Starting::. GDB defines some parameters that can be passed to the `attach' request. Either `pid' or `target' must be specified, but if both are specified then `target' will be ignored. `pid' The process ID to which GDB should attach. *Note Attach::. `program' If provided, this is a string that specifies the program to use. This corresponds to the `file' command. *Note Files::. In some cases, GDB can automatically determine which program is running. However, for many remote targets, this is not the case, and so this should be supplied. `target' The target to which GDB should connect. This is a string and is passed to the `target remote' command. *Note Connecting::. In response to the `disassemble' request, DAP allows the client to return the bytes of each instruction in an implementation-defined format. GDB implements this by sending a string with the bytes encoded in hex, like `"55a2b900"'. When the `repl' context is used for the `evaluate' request, GDB evaluates the provided expression as a CLI command. Evaluation in general can cause the inferior to continue execution. For example, evaluating the `continue' command could do this, as could evaluating an expression that involves an inferior function call. `repl' evaluation can also cause GDB to appear to stop responding to requests, for example if a CLI script does a lengthy computation. Evaluations like this can be interrupted using the DAP `cancel' request. (In fact, `cancel' should work for any request, but it is unlikely to be useful for most of them.) GDB provides a couple of logging settings that can be used in DAP mode. These can be set on the command line using the `-iex' option (*note File Options::). `set debug dap-log-file [FILENAME]' Enable DAP logging. Logs are written to FILENAME. If no FILENAME is given, logging is stopped. `set debug dap-log-level LEVEL' Set the DAP logging level. The default is `1', which logs the DAP protocol, whatever debug messages the developers thought were useful, and unexpected exceptions. Level `2' can be used to log all exceptions, including ones that are considered to be expected. For example, a failure to parse an expression would be considered a normal exception and not normally be logged.  File: gdb.info, Node: JIT Interface, Next: In-Process Agent, Prev: Debugger Adapter Protocol, Up: Top 30 JIT Compilation Interface **************************** This chapter documents GDB's "just-in-time" (JIT) compilation interface. A JIT compiler is a program or library that generates native executable code at runtime and executes it, usually in order to achieve good performance while maintaining platform independence. Programs that use JIT compilation are normally difficult to debug because portions of their code are generated at runtime, instead of being loaded from object files, which is where GDB normally finds the program's symbols and debug information. In order to debug programs that use JIT compilation, GDB has an interface that allows the program to register in-memory symbol files with GDB at runtime. If you are using GDB to debug a program that uses this interface, then it should work transparently so long as you have not stripped the binary. If you are developing a JIT compiler, then the interface is documented in the rest of this chapter. At this time, the only known client of this interface is the LLVM JIT. Broadly speaking, the JIT interface mirrors the dynamic loader interface. The JIT compiler communicates with GDB by writing data into a global variable and calling a function at a well-known symbol. When GDB attaches, it reads a linked list of symbol files from the global variable to find existing code, and puts a breakpoint in the function so that it can find out about additional code. * Menu: * Declarations:: Relevant C struct declarations * Registering Code:: Steps to register code * Unregistering Code:: Steps to unregister code * Custom Debug Info:: Emit debug information in a custom format  File: gdb.info, Node: Declarations, Next: Registering Code, Up: JIT Interface 30.1 JIT Declarations ===================== These are the relevant struct declarations that a C program should include to implement the interface: typedef enum { JIT_NOACTION = 0, JIT_REGISTER_FN, JIT_UNREGISTER_FN } jit_actions_t; struct jit_code_entry { struct jit_code_entry *next_entry; struct jit_code_entry *prev_entry; const char *symfile_addr; uint64_t symfile_size; }; struct jit_descriptor { uint32_t version; /* This type should be jit_actions_t, but we use uint32_t to be explicit about the bitwidth. */ uint32_t action_flag; struct jit_code_entry *relevant_entry; struct jit_code_entry *first_entry; }; /* GDB puts a breakpoint in this function. */ void __attribute__((noinline)) __jit_debug_register_code() { }; /* Make sure to specify the version statically, because the debugger may check the version before we can set it. */ struct jit_descriptor __jit_debug_descriptor = { 1, 0, 0, 0 }; If the JIT is multi-threaded, then it is important that the JIT synchronize any modifications to this global data properly, which can easily be done by putting a global mutex around modifications to these structures.  File: gdb.info, Node: Registering Code, Next: Unregistering Code, Prev: Declarations, Up: JIT Interface 30.2 Registering Code ===================== To register code with GDB, the JIT should follow this protocol: * Generate an object file in memory with symbols and other desired debug information. The file must include the virtual addresses of the sections. * Create a code entry for the file, which gives the start and size of the symbol file. * Add it to the linked list in the JIT descriptor. * Point the relevant_entry field of the descriptor at the entry. * Set `action_flag' to `JIT_REGISTER' and call `__jit_debug_register_code'. When GDB is attached and the breakpoint fires, GDB uses the `relevant_entry' pointer so it doesn't have to walk the list looking for new code. However, the linked list must still be maintained in order to allow GDB to attach to a running process and still find the symbol files.  File: gdb.info, Node: Unregistering Code, Next: Custom Debug Info, Prev: Registering Code, Up: JIT Interface 30.3 Unregistering Code ======================= If code is freed, then the JIT should use the following protocol: * Remove the code entry corresponding to the code from the linked list. * Point the `relevant_entry' field of the descriptor at the code entry. * Set `action_flag' to `JIT_UNREGISTER' and call `__jit_debug_register_code'. If the JIT frees or recompiles code without unregistering it, then GDB and the JIT will leak the memory used for the associated symbol files.  File: gdb.info, Node: Custom Debug Info, Prev: Unregistering Code, Up: JIT Interface 30.4 Custom Debug Info ====================== Generating debug information in platform-native file formats (like ELF or COFF) may be an overkill for JIT compilers; especially if all the debug info is used for is displaying a meaningful backtrace. The issue can be resolved by having the JIT writers decide on a debug info format and also provide a reader that parses the debug info generated by the JIT compiler. This section gives a brief overview on writing such a parser. More specific details can be found in the source file `gdb/jit-reader.in', which is also installed as a header at `INCLUDEDIR/gdb/jit-reader.h' for easy inclusion. The reader is implemented as a shared object (so this functionality is not available on platforms which don't allow loading shared objects at runtime). Two GDB commands, `jit-reader-load' and `jit-reader-unload' are provided, to be used to load and unload the readers from a preconfigured directory. Once loaded, the shared object is used the parse the debug information emitted by the JIT compiler. * Menu: * Using JIT Debug Info Readers:: How to use supplied readers correctly * Writing JIT Debug Info Readers:: Creating a debug-info reader  File: gdb.info, Node: Using JIT Debug Info Readers, Next: Writing JIT Debug Info Readers, Up: Custom Debug Info 30.4.1 Using JIT Debug Info Readers ----------------------------------- Readers can be loaded and unloaded using the `jit-reader-load' and `jit-reader-unload' commands. `jit-reader-load READER' Load the JIT reader named READER, which is a shared object specified as either an absolute or a relative file name. In the latter case, GDB will try to load the reader from a pre-configured directory, usually `LIBDIR/gdb/' on a UNIX system (here LIBDIR is the system library directory, often `/usr/local/lib'). Only one reader can be active at a time; trying to load a second reader when one is already loaded will result in GDB reporting an error. A new JIT reader can be loaded by first unloading the current one using `jit-reader-unload' and then invoking `jit-reader-load'. `jit-reader-unload' Unload the currently loaded JIT reader.  File: gdb.info, Node: Writing JIT Debug Info Readers, Prev: Using JIT Debug Info Readers, Up: Custom Debug Info 30.4.2 Writing JIT Debug Info Readers ------------------------------------- As mentioned, a reader is essentially a shared object conforming to a certain ABI. This ABI is described in `jit-reader.h'. `jit-reader.h' defines the structures, macros and functions required to write a reader. It is installed (along with GDB), in `INCLUDEDIR/gdb' where INCLUDEDIR is the system include directory. Readers need to be released under a GPL compatible license. A reader can be declared as released under such a license by placing the macro `GDB_DECLARE_GPL_COMPATIBLE_READER' in a source file. The entry point for readers is the symbol `gdb_init_reader', which is expected to be a function with the prototype extern struct gdb_reader_funcs *gdb_init_reader (void); `struct gdb_reader_funcs' contains a set of pointers to callback functions. These functions are executed to read the debug info generated by the JIT compiler (`read'), to unwind stack frames (`unwind') and to create canonical frame IDs (`get_frame_id'). It also has a callback that is called when the reader is being unloaded (`destroy'). The struct looks like this struct gdb_reader_funcs { /* Must be set to GDB_READER_INTERFACE_VERSION. */ int reader_version; /* For use by the reader. */ void *priv_data; gdb_read_debug_info *read; gdb_unwind_frame *unwind; gdb_get_frame_id *get_frame_id; gdb_destroy_reader *destroy; }; The callbacks are provided with another set of callbacks by GDB to do their job. For `read', these callbacks are passed in a `struct gdb_symbol_callbacks' and for `unwind' and `get_frame_id', in a `struct gdb_unwind_callbacks'. `struct gdb_symbol_callbacks' has callbacks to create new object files and new symbol tables inside those object files. `struct gdb_unwind_callbacks' has callbacks to read registers off the current frame and to write out the values of the registers in the previous frame. Both have a callback (`target_read') to read bytes off the target's address space.  File: gdb.info, Node: In-Process Agent, Next: GDB Bugs, Prev: JIT Interface, Up: Top 31 In-Process Agent ******************* The traditional debugging model is conceptually low-speed, but works fine, because most bugs can be reproduced in debugging-mode execution. However, as multi-core or many-core processors are becoming mainstream, and multi-threaded programs become more and more popular, there should be more and more bugs that only manifest themselves at normal-mode execution, for example, thread races, because debugger's interference with the program's timing may conceal the bugs. On the other hand, in some applications, it is not feasible for the debugger to interrupt the program's execution long enough for the developer to learn anything helpful about its behavior. If the program's correctness depends on its real-time behavior, delays introduced by a debugger might cause the program to fail, even when the code itself is correct. It is useful to be able to observe the program's behavior without interrupting it. Therefore, traditional debugging model is too intrusive to reproduce some bugs. In order to reduce the interference with the program, we can reduce the number of operations performed by debugger. The "In-Process Agent", a shared library, is running within the same process with inferior, and is able to perform some debugging operations itself. As a result, debugger is only involved when necessary, and performance of debugging can be improved accordingly. Note that interference with program can be reduced but can't be removed completely, because the in-process agent will still stop or slow down the program. The in-process agent can interpret and execute Agent Expressions (*note Agent Expressions::) during performing debugging operations. The agent expressions can be used for different purposes, such as collecting data in tracepoints, and condition evaluation in breakpoints. You can control whether the in-process agent is used as an aid for debugging with the following commands: `set agent on' Causes the in-process agent to perform some operations on behalf of the debugger. Just which operations requested by the user will be done by the in-process agent depends on the its capabilities. For example, if you request to evaluate breakpoint conditions in the in-process agent, and the in-process agent has such capability as well, then breakpoint conditions will be evaluated in the in-process agent. `set agent off' Disables execution of debugging operations by the in-process agent. All of the operations will be performed by GDB. `show agent' Display the current setting of execution of debugging operations by the in-process agent. * Menu: * In-Process Agent Protocol::  File: gdb.info, Node: In-Process Agent Protocol, Up: In-Process Agent 31.1 In-Process Agent Protocol ============================== The in-process agent is able to communicate with both GDB and GDBserver (*note In-Process Agent::). This section documents the protocol used for communications between GDB or GDBserver and the IPA. In general, GDB or GDBserver sends commands (*note IPA Protocol Commands::) and data to in-process agent, and then in-process agent replies back with the return result of the command, or some other information. The data sent to in-process agent is composed of primitive data types, such as 4-byte or 8-byte type, and composite types, which are called objects (*note IPA Protocol Objects::). * Menu: * IPA Protocol Objects:: * IPA Protocol Commands::  File: gdb.info, Node: IPA Protocol Objects, Next: IPA Protocol Commands, Up: In-Process Agent Protocol 31.1.1 IPA Protocol Objects --------------------------- The commands sent to and results received from agent may contain some complex data types called "objects". The in-process agent is running on the same machine with GDB or GDBserver, so it doesn't have to handle as much differences between two ends as remote protocol (*note Remote Protocol::) tries to handle. However, there are still some differences of two ends in two processes: 1. word size. On some 64-bit machines, GDB or GDBserver can be compiled as a 64-bit executable, while in-process agent is a 32-bit one. 2. ABI. Some machines may have multiple types of ABI, GDB or GDBserver is compiled with one, and in-process agent is compiled with the other one. Here are the IPA Protocol Objects: 1. agent expression object. It represents an agent expression (*note Agent Expressions::). 2. tracepoint action object. It represents a tracepoint action (*note Tracepoint Action Lists: Tracepoint Actions.) to collect registers, memory, static trace data and to evaluate expression. 3. tracepoint object. It represents a tracepoint (*note Tracepoints::). The following table describes important attributes of each IPA protocol object: Name Size Description --------------------------------------------------------------------------- _agent expression object_ length 4 length of bytes code byte code LENGTH contents of byte code _tracepoint action for collecting memory_ 'M' 1 type of tracepoint action addr 8 if BASEREG is `-1', ADDR is the address of the lowest byte to collect, otherwise ADDR is the offset of BASEREG for memory collecting. len 8 length of memory for collecting basereg 4 the register number containing the starting memory address for collecting. _tracepoint action for collecting registers_ 'R' 1 type of tracepoint action _tracepoint action for collecting static trace data_ 'L' 1 type of tracepoint action _tracepoint action for expression evaluation_ 'X' 1 type of tracepoint action agent expression length of *Note agent expression object:: _tracepoint object_ number 4 number of tracepoint address 8 address of tracepoint inserted on type 4 type of tracepoint enabled 1 enable or disable of tracepoint step_count 8 step pass_count 8 pass numactions 4 number of tracepoint actions hit count 8 hit count trace frame usage 8 trace frame usage compiled_cond 8 compiled condition orig_size 8 orig size condition 4 if zero if condition is NULL, condition is otherwise is *Note agent expression NULL object:: otherwise length of *Note agent expression object:: actions variable numactions number of *Note tracepoint action object::  File: gdb.info, Node: IPA Protocol Commands, Prev: IPA Protocol Objects, Up: In-Process Agent Protocol 31.1.2 IPA Protocol Commands ---------------------------- The spaces in each command are delimiters to ease reading this commands specification. They don't exist in real commands. `FastTrace:TRACEPOINT_OBJECT GDB_JUMP_PAD_HEAD' Installs a new fast tracepoint described by TRACEPOINT_OBJECT (*note tracepoint object::). The GDB_JUMP_PAD_HEAD, 8-byte long, is the head of "jumppad", which is used to jump to data collection routine in IPA finally. Replies: `OK TARGET_ADDRESS GDB_JUMP_PAD_HEAD FJUMP_SIZE FJUMP' TARGET_ADDRESS is address of tracepoint in the inferior. The GDB_JUMP_PAD_HEAD is updated head of jumppad. Both of TARGET_ADDRESS and GDB_JUMP_PAD_HEAD are 8-byte long. The FJUMP contains a sequence of instructions jump to jumppad entry. The FJUMP_SIZE, 4-byte long, is the size of FJUMP. `close' Closes the in-process agent. This command is sent when GDB or GDBserver is about to kill inferiors. `qTfSTM' *Note qTfSTM::. `qTsSTM' *Note qTsSTM::. `qTSTMat' *Note qTSTMat::. `probe_marker_at:ADDRESS' Asks in-process agent to probe the marker at ADDRESS. Replies: `unprobe_marker_at:ADDRESS' Asks in-process agent to unprobe the marker at ADDRESS.  File: gdb.info, Node: GDB Bugs, Next: Command Line Editing, Prev: In-Process Agent, Up: Top 32 Reporting Bugs in GDB ************************ Your bug reports play an essential role in making GDB reliable. Reporting a bug may help you by bringing a solution to your problem, or it may not. But in any case the principal function of a bug report is to help the entire community by making the next version of GDB work better. Bug reports are your contribution to the maintenance of GDB. In order for a bug report to serve its purpose, you must include the information that enables us to fix the bug. * Menu: * Bug Criteria:: Have you found a bug? * Bug Reporting:: How to report bugs  File: gdb.info, Node: Bug Criteria, Next: Bug Reporting, Up: GDB Bugs 32.1 Have You Found a Bug? ========================== If you are not sure whether you have found a bug, here are some guidelines: * If the debugger gets a fatal signal, for any input whatever, that is a GDB bug. Reliable debuggers never crash. * If GDB produces an error message for valid input, that is a bug. (Note that if you're cross debugging, the problem may also be somewhere in the connection to the target.) * If GDB does not produce an error message for invalid input, that is a bug. However, you should note that your idea of "invalid input" might be our idea of "an extension" or "support for traditional practice". * If you are an experienced user of debugging tools, your suggestions for improvement of GDB are welcome in any case.  File: gdb.info, Node: Bug Reporting, Prev: Bug Criteria, Up: GDB Bugs 32.2 How to Report Bugs ======================= A number of companies and individuals offer support for GNU products. If you obtained GDB from a support organization, we recommend you contact that organization first. You can find contact information for many support companies and individuals in the file `etc/SERVICE' in the GNU Emacs distribution. In any event, we also recommend that you submit bug reports for GDB to `https://www.gnu.org/software/gdb/bugs/'. The fundamental principle of reporting bugs usefully is this: *report all the facts*. If you are not sure whether to state a fact or leave it out, state it! Often people omit facts because they think they know what causes the problem and assume that some details do not matter. Thus, you might assume that the name of the variable you use in an example does not matter. Well, probably it does not, but one cannot be sure. Perhaps the bug is a stray memory reference which happens to fetch from the location where that name is stored in memory; perhaps, if the name were different, the contents of that location would fool the debugger into doing the right thing despite the bug. Play it safe and give a specific, complete example. That is the easiest thing for you to do, and the most helpful. Keep in mind that the purpose of a bug report is to enable us to fix the bug. It may be that the bug has been reported previously, but neither you nor we can know that unless your bug report is complete and self-contained. Sometimes people give a few sketchy facts and ask, "Does this ring a bell?" Those bug reports are useless, and we urge everyone to _refuse to respond to them_ except to chide the sender to report bugs properly. To enable us to fix the bug, you should include all these things: * The version of GDB. GDB announces it if you start with no arguments; you can also print it at any time using `show version'. Without this, we will not know whether there is any point in looking for the bug in the current version of GDB. * The type of machine you are using, and the operating system name and version number. * The details of the GDB build-time configuration. GDB shows these details if you invoke it with the `--configuration' command-line option, or if you type `show configuration' at GDB's prompt. * What compiler (and its version) was used to compile GDB--e.g. "gcc-2.8.1". * What compiler (and its version) was used to compile the program you are debugging--e.g. "gcc-2.8.1", or "HP92453-01 A.10.32.03 HP C Compiler". For GCC, you can say `gcc --version' to get this information; for other compilers, see the documentation for those compilers. * The command arguments you gave the compiler to compile your example and observe the bug. For example, did you use `-O'? To guarantee you will not omit something important, list them all. A copy of the Makefile (or the output from make) is sufficient. If we were to try to guess the arguments, we would probably guess wrong and then we might not encounter the bug. * A complete input script, and all necessary source files, that will reproduce the bug. * A description of what behavior you observe that you believe is incorrect. For example, "It gets a fatal signal." Of course, if the bug is that GDB gets a fatal signal, then we will certainly notice it. But if the bug is incorrect output, we might not notice unless it is glaringly wrong. You might as well not give us a chance to make a mistake. Even if the problem you experience is a fatal signal, you should still say so explicitly. Suppose something strange is going on, such as, your copy of GDB is out of synch, or you have encountered a bug in the C library on your system. (This has happened!) Your copy might crash and ours would not. If you told us to expect a crash, then when ours fails to crash, we would know that the bug was not happening for us. If you had not told us to expect a crash, then we would not be able to draw any conclusion from our observations. To collect all this information, you can use a session recording program such as `script', which is available on many Unix systems. Just run your GDB session inside `script' and then include the `typescript' file with your bug report. Another way to record a GDB session is to run GDB inside Emacs and then save the entire buffer to a file. * If you wish to suggest changes to the GDB source, send us context diffs. If you even discuss something in the GDB source, refer to it by context, not by line number. The line numbers in our development sources will not match those in your sources. Your line numbers would convey no useful information to us. Here are some things that are not necessary: * A description of the envelope of the bug. Often people who encounter a bug spend a lot of time investigating which changes to the input file will make the bug go away and which changes will not affect it. This is often time consuming and not very useful, because the way we will find the bug is by running a single example under the debugger with breakpoints, not by pure deduction from a series of examples. We recommend that you save your time for something else. Of course, if you can find a simpler example to report _instead_ of the original one, that is a convenience for us. Errors in the output will be easier to spot, running under the debugger will take less time, and so on. However, simplification is not vital; if you do not want to do this, report the bug anyway and send us the entire test case you used. * A patch for the bug. A patch for the bug does help us if it is a good one. But do not omit the necessary information, such as the test case, on the assumption that a patch is all we need. We might see problems with your patch and decide to fix the problem another way, or we might not understand it at all. Sometimes with a program as complicated as GDB it is very hard to construct an example that will make the program follow a certain path through the code. If you do not send us the example, we will not be able to construct one, so we will not be able to verify that the bug is fixed. And if we cannot understand what bug you are trying to fix, or why your patch should be an improvement, we will not install it. A test case will help us to understand. * A guess about what the bug is or what it depends on. Such guesses are usually wrong. Even we cannot guess right about such things without first using the debugger to find the facts.  File: gdb.info, Node: Command Line Editing, Next: Using History Interactively, Prev: GDB Bugs, Up: Top 33 Command Line Editing *********************** This chapter describes the basic features of the GNU command line editing interface. * Menu: * Introduction and Notation:: Notation used in this text. * Readline Interaction:: The minimum set of commands for editing a line. * Readline Init File:: Customizing Readline from a user's view. * Bindable Readline Commands:: A description of most of the Readline commands available for binding * Readline vi Mode:: A short description of how to make Readline behave like the vi editor.  File: gdb.info, Node: Introduction and Notation, Next: Readline Interaction, Up: Command Line Editing 33.1 Introduction to Line Editing ================================= The following paragraphs describe the notation used to represent keystrokes. The text `C-k' is read as `Control-K' and describes the character produced when the key is pressed while the Control key is depressed. The text `M-k' is read as `Meta-K' and describes the character produced when the Meta key (if you have one) is depressed, and the key is pressed. The Meta key is labeled on many keyboards. On keyboards with two keys labeled (usually to either side of the space bar), the on the left side is generally set to work as a Meta key. The key on the right may also be configured to work as a Meta key or may be configured as some other modifier, such as a Compose key for typing accented characters. If you do not have a Meta or key, or another key working as a Meta key, the identical keystroke can be generated by typing _first_, and then typing . Either process is known as "metafying" the key. The text `M-C-k' is read as `Meta-Control-k' and describes the character produced by "metafying" `C-k'. In addition, several keys have their own names. Specifically, , , , , , and all stand for themselves when seen in this text, or in an init file (*note Readline Init File::). If your keyboard lacks a key, typing will produce the desired character. The key may be labeled or on some keyboards.  File: gdb.info, Node: Readline Interaction, Next: Readline Init File, Prev: Introduction and Notation, Up: Command Line Editing 33.2 Readline Interaction ========================= Often during an interactive session you type in a long line of text, only to notice that the first word on the line is misspelled. The Readline library gives you a set of commands for manipulating the text as you type it in, allowing you to just fix your typo, and not forcing you to retype the majority of the line. Using these editing commands, you move the cursor to the place that needs correction, and delete or insert the text of the corrections. Then, when you are satisfied with the line, you simply press . You do not have to be at the end of the line to press ; the entire line is accepted regardless of the location of the cursor within the line. * Menu: * Readline Bare Essentials:: The least you need to know about Readline. * Readline Movement Commands:: Moving about the input line. * Readline Killing Commands:: How to delete text, and how to get it back! * Readline Arguments:: Giving numeric arguments to commands. * Searching:: Searching through previous lines.  File: gdb.info, Node: Readline Bare Essentials, Next: Readline Movement Commands, Up: Readline Interaction 33.2.1 Readline Bare Essentials ------------------------------- In order to enter characters into the line, simply type them. The typed character appears where the cursor was, and then the cursor moves one space to the right. If you mistype a character, you can use your erase character to back up and delete the mistyped character. Sometimes you may mistype a character, and not notice the error until you have typed several other characters. In that case, you can type `C-b' to move the cursor to the left, and then correct your mistake. Afterwards, you can move the cursor to the right with `C-f'. When you add text in the middle of a line, you will notice that characters to the right of the cursor are `pushed over' to make room for the text that you have inserted. Likewise, when you delete text behind the cursor, characters to the right of the cursor are `pulled back' to fill in the blank space created by the removal of the text. A list of the bare essentials for editing the text of an input line follows. `C-b' Move back one character. `C-f' Move forward one character. or Delete the character to the left of the cursor. `C-d' Delete the character underneath the cursor. Printing characters Insert the character into the line at the cursor. `C-_' or `C-x C-u' Undo the last editing command. You can undo all the way back to an empty line. (Depending on your configuration, the key be set to delete the character to the left of the cursor and the key set to delete the character underneath the cursor, like `C-d', rather than the character to the left of the cursor.)  File: gdb.info, Node: Readline Movement Commands, Next: Readline Killing Commands, Prev: Readline Bare Essentials, Up: Readline Interaction 33.2.2 Readline Movement Commands --------------------------------- The above table describes the most basic keystrokes that you need in order to do editing of the input line. For your convenience, many other commands have been added in addition to `C-b', `C-f', `C-d', and . Here are some commands for moving more rapidly about the line. `C-a' Move to the start of the line. `C-e' Move to the end of the line. `M-f' Move forward a word, where a word is composed of letters and digits. `M-b' Move backward a word. `C-l' Clear the screen, reprinting the current line at the top. Notice how `C-f' moves forward a character, while `M-f' moves forward a word. It is a loose convention that control keystrokes operate on characters while meta keystrokes operate on words.  File: gdb.info, Node: Readline Killing Commands, Next: Readline Arguments, Prev: Readline Movement Commands, Up: Readline Interaction 33.2.3 Readline Killing Commands -------------------------------- "Killing" text means to delete the text from the line, but to save it away for later use, usually by "yanking" (re-inserting) it back into the line. (`Cut' and `paste' are more recent jargon for `kill' and `yank'.) If the description for a command says that it `kills' text, then you can be sure that you can get the text back in a different (or the same) place later. When you use a kill command, the text is saved in a "kill-ring". Any number of consecutive kills save all of the killed text together, so that when you yank it back, you get it all. The kill ring is not line specific; the text that you killed on a previously typed line is available to be yanked back later, when you are typing another line. Here is the list of commands for killing text. `C-k' Kill the text from the current cursor position to the end of the line. `M-d' Kill from the cursor to the end of the current word, or, if between words, to the end of the next word. Word boundaries are the same as those used by `M-f'. `M-' Kill from the cursor the start of the current word, or, if between words, to the start of the previous word. Word boundaries are the same as those used by `M-b'. `C-w' Kill from the cursor to the previous whitespace. This is different than `M-' because the word boundaries differ. Here is how to "yank" the text back into the line. Yanking means to copy the most-recently-killed text from the kill buffer. `C-y' Yank the most recently killed text back into the buffer at the cursor. `M-y' Rotate the kill-ring, and yank the new top. You can only do this if the prior command is `C-y' or `M-y'.  File: gdb.info, Node: Readline Arguments, Next: Searching, Prev: Readline Killing Commands, Up: Readline Interaction 33.2.4 Readline Arguments ------------------------- You can pass numeric arguments to Readline commands. Sometimes the argument acts as a repeat count, other times it is the sign of the argument that is significant. If you pass a negative argument to a command which normally acts in a forward direction, that command will act in a backward direction. For example, to kill text back to the start of the line, you might type `M-- C-k'. The general way to pass numeric arguments to a command is to type meta digits before the command. If the first `digit' typed is a minus sign (`-'), then the sign of the argument will be negative. Once you have typed one meta digit to get the argument started, you can type the remainder of the digits, and then the command. For example, to give the `C-d' command an argument of 10, you could type `M-1 0 C-d', which will delete the next ten characters on the input line.  File: gdb.info, Node: Searching, Prev: Readline Arguments, Up: Readline Interaction 33.2.5 Searching for Commands in the History -------------------------------------------- Readline provides commands for searching through the command history for lines containing a specified string. There are two search modes: "incremental" and "non-incremental". Incremental searches begin before the user has finished typing the search string. As each character of the search string is typed, Readline displays the next entry from the history matching the string typed so far. An incremental search requires only as many characters as needed to find the desired history entry. To search backward in the history for a particular string, type `C-r'. Typing `C-s' searches forward through the history. The characters present in the value of the `isearch-terminators' variable are used to terminate an incremental search. If that variable has not been assigned a value, the and `C-J' characters will terminate an incremental search. `C-g' will abort an incremental search and restore the original line. When the search is terminated, the history entry containing the search string becomes the current line. To find other matching entries in the history list, type `C-r' or `C-s' as appropriate. This will search backward or forward in the history for the next entry matching the search string typed so far. Any other key sequence bound to a Readline command will terminate the search and execute that command. For instance, a will terminate the search and accept the line, thereby executing the command from the history list. A movement command will terminate the search, make the last line found the current line, and begin editing. Readline remembers the last incremental search string. If two `C-r's are typed without any intervening characters defining a new search string, any remembered search string is used. Non-incremental searches read the entire search string before starting to search for matching history lines. The search string may be typed by the user or be part of the contents of the current line.  File: gdb.info, Node: Readline Init File, Next: Bindable Readline Commands, Prev: Readline Interaction, Up: Command Line Editing 33.3 Readline Init File ======================= Although the Readline library comes with a set of Emacs-like keybindings installed by default, it is possible to use a different set of keybindings. Any user can customize programs that use Readline by putting commands in an "inputrc" file, conventionally in his home directory. The name of this file is taken from the value of the environment variable `INPUTRC'. If that variable is unset, the default is `~/.inputrc'. If that file does not exist or cannot be read, the ultimate default is `/etc/inputrc'. When a program which uses the Readline library starts up, the init file is read, and the key bindings are set. In addition, the `C-x C-r' command re-reads this init file, thus incorporating any changes that you might have made to it. * Menu: * Readline Init File Syntax:: Syntax for the commands in the inputrc file. * Conditional Init Constructs:: Conditional key bindings in the inputrc file. * Sample Init File:: An example inputrc file.  File: gdb.info, Node: Readline Init File Syntax, Next: Conditional Init Constructs, Up: Readline Init File 33.3.1 Readline Init File Syntax -------------------------------- There are only a few basic constructs allowed in the Readline init file. Blank lines are ignored. Lines beginning with a `#' are comments. Lines beginning with a `$' indicate conditional constructs (*note Conditional Init Constructs::). Other lines denote variable settings and key bindings. Variable Settings You can modify the run-time behavior of Readline by altering the values of variables in Readline using the `set' command within the init file. The syntax is simple: set VARIABLE VALUE Here, for example, is how to change from the default Emacs-like key binding to use `vi' line editing commands: set editing-mode vi Variable names and values, where appropriate, are recognized without regard to case. Unrecognized variable names are ignored. Boolean variables (those that can be set to on or off) are set to on if the value is null or empty, ON (case-insensitive), or 1. Any other value results in the variable being set to off. A great deal of run-time behavior is changeable with the following variables. `bell-style' Controls what happens when Readline wants to ring the terminal bell. If set to `none', Readline never rings the bell. If set to `visible', Readline uses a visible bell if one is available. If set to `audible' (the default), Readline attempts to ring the terminal's bell. `bind-tty-special-chars' If set to `on' (the default), Readline attempts to bind the control characters treated specially by the kernel's terminal driver to their Readline equivalents. `blink-matching-paren' If set to `on', Readline attempts to briefly move the cursor to an opening parenthesis when a closing parenthesis is inserted. The default is `off'. `colored-completion-prefix' If set to `on', when listing completions, Readline displays the common prefix of the set of possible completions using a different color. The color definitions are taken from the value of the `LS_COLORS' environment variable. The default is `off'. `colored-stats' If set to `on', Readline displays possible completions using different colors to indicate their file type. The color definitions are taken from the value of the `LS_COLORS' environment variable. The default is `off'. `comment-begin' The string to insert at the beginning of the line when the `insert-comment' command is executed. The default value is `"#"'. `completion-display-width' The number of screen columns used to display possible matches when performing completion. The value is ignored if it is less than 0 or greater than the terminal screen width. A value of 0 will cause matches to be displayed one per line. The default value is -1. `completion-ignore-case' If set to `on', Readline performs filename matching and completion in a case-insensitive fashion. The default value is `off'. `completion-map-case' If set to `on', and COMPLETION-IGNORE-CASE is enabled, Readline treats hyphens (`-') and underscores (`_') as equivalent when performing case-insensitive filename matching and completion. The default value is `off'. `completion-prefix-display-length' The length in characters of the common prefix of a list of possible completions that is displayed without modification. When set to a value greater than zero, common prefixes longer than this value are replaced with an ellipsis when displaying possible completions. `completion-query-items' The number of possible completions that determines when the user is asked whether the list of possibilities should be displayed. If the number of possible completions is greater than or equal to this value, Readline will ask whether or not the user wishes to view them; otherwise, they are simply listed. This variable must be set to an integer value greater than or equal to 0. A negative value means Readline should never ask. The default limit is `100'. `convert-meta' If set to `on', Readline will convert characters with the eighth bit set to an ASCII key sequence by stripping the eighth bit and prefixing an character, converting them to a meta-prefixed key sequence. The default value is `on', but will be set to `off' if the locale is one that contains eight-bit characters. `disable-completion' If set to `On', Readline will inhibit word completion. Completion characters will be inserted into the line as if they had been mapped to `self-insert'. The default is `off'. `echo-control-characters' When set to `on', on operating systems that indicate they support it, readline echoes a character corresponding to a signal generated from the keyboard. The default is `on'. `editing-mode' The `editing-mode' variable controls which default set of key bindings is used. By default, Readline starts up in Emacs editing mode, where the keystrokes are most similar to Emacs. This variable can be set to either `emacs' or `vi'. `emacs-mode-string' If the SHOW-MODE-IN-PROMPT variable is enabled, this string is displayed immediately before the last line of the primary prompt when emacs editing mode is active. The value is expanded like a key binding, so the standard set of meta- and control prefixes and backslash escape sequences is available. Use the `\1' and `\2' escapes to begin and end sequences of non-printing characters, which can be used to embed a terminal control sequence into the mode string. The default is `@@'. `enable-bracketed-paste' When set to `On', Readline will configure the terminal in a way that will enable it to insert each paste into the editing buffer as a single string of characters, instead of treating each character as if it had been read from the keyboard. This can prevent pasted characters from being interpreted as editing commands. The default is `On'. `enable-keypad' When set to `on', Readline will try to enable the application keypad when it is called. Some systems need this to enable the arrow keys. The default is `off'. `enable-meta-key' When set to `on', Readline will try to enable any meta modifier key the terminal claims to support when it is called. On many terminals, the meta key is used to send eight-bit characters. The default is `on'. `expand-tilde' If set to `on', tilde expansion is performed when Readline attempts word completion. The default is `off'. `history-preserve-point' If set to `on', the history code attempts to place the point (the current cursor position) at the same location on each history line retrieved with `previous-history' or `next-history'. The default is `off'. `history-size' Set the maximum number of history entries saved in the history list. If set to zero, any existing history entries are deleted and no new entries are saved. If set to a value less than zero, the number of history entries is not limited. By default, the number of history entries is not limited. If an attempt is made to set HISTORY-SIZE to a non-numeric value, the maximum number of history entries will be set to 500. `horizontal-scroll-mode' This variable can be set to either `on' or `off'. Setting it to `on' means that the text of the lines being edited will scroll horizontally on a single screen line when they are longer than the width of the screen, instead of wrapping onto a new screen line. This variable is automatically set to `on' for terminals of height 1. By default, this variable is set to `off'. `input-meta' If set to `on', Readline will enable eight-bit input (it will not clear the eighth bit in the characters it reads), regardless of what the terminal claims it can support. The default value is `off', but Readline will set it to `on' if the locale contains eight-bit characters. The name `meta-flag' is a synonym for this variable. `isearch-terminators' The string of characters that should terminate an incremental search without subsequently executing the character as a command (*note Searching::). If this variable has not been given a value, the characters and `C-J' will terminate an incremental search. `keymap' Sets Readline's idea of the current keymap for key binding commands. Built-in `keymap' names are `emacs', `emacs-standard', `emacs-meta', `emacs-ctlx', `vi', `vi-move', `vi-command', and `vi-insert'. `vi' is equivalent to `vi-command' (`vi-move' is also a synonym); `emacs' is equivalent to `emacs-standard'. Applications may add additional names. The default value is `emacs'. The value of the `editing-mode' variable also affects the default keymap. `keyseq-timeout' Specifies the duration Readline will wait for a character when reading an ambiguous key sequence (one that can form a complete key sequence using the input read so far, or can take additional input to complete a longer key sequence). If no input is received within the timeout, Readline will use the shorter but complete key sequence. Readline uses this value to determine whether or not input is available on the current input source (`rl_instream' by default). The value is specified in milliseconds, so a value of 1000 means that Readline will wait one second for additional input. If this variable is set to a value less than or equal to zero, or to a non-numeric value, Readline will wait until another key is pressed to decide which key sequence to complete. The default value is `500'. `mark-directories' If set to `on', completed directory names have a slash appended. The default is `on'. `mark-modified-lines' This variable, when set to `on', causes Readline to display an asterisk (`*') at the start of history lines which have been modified. This variable is `off' by default. `mark-symlinked-directories' If set to `on', completed names which are symbolic links to directories have a slash appended (subject to the value of `mark-directories'). The default is `off'. `match-hidden-files' This variable, when set to `on', causes Readline to match files whose names begin with a `.' (hidden files) when performing filename completion. If set to `off', the leading `.' must be supplied by the user in the filename to be completed. This variable is `on' by default. `menu-complete-display-prefix' If set to `on', menu completion displays the common prefix of the list of possible completions (which may be empty) before cycling through the list. The default is `off'. `output-meta' If set to `on', Readline will display characters with the eighth bit set directly rather than as a meta-prefixed escape sequence. The default is `off', but Readline will set it to `on' if the locale contains eight-bit characters. `page-completions' If set to `on', Readline uses an internal `more'-like pager to display a screenful of possible completions at a time. This variable is `on' by default. `print-completions-horizontally' If set to `on', Readline will display completions with matches sorted horizontally in alphabetical order, rather than down the screen. The default is `off'. `revert-all-at-newline' If set to `on', Readline will undo all changes to history lines before returning when `accept-line' is executed. By default, history lines may be modified and retain individual undo lists across calls to `readline'. The default is `off'. `show-all-if-ambiguous' This alters the default behavior of the completion functions. If set to `on', words which have more than one possible completion cause the matches to be listed immediately instead of ringing the bell. The default value is `off'. `show-all-if-unmodified' This alters the default behavior of the completion functions in a fashion similar to SHOW-ALL-IF-AMBIGUOUS. If set to `on', words which have more than one possible completion without any possible partial completion (the possible completions don't share a common prefix) cause the matches to be listed immediately instead of ringing the bell. The default value is `off'. `show-mode-in-prompt' If set to `on', add a string to the beginning of the prompt indicating the editing mode: emacs, vi command, or vi insertion. The mode strings are user-settable (e.g., EMACS-MODE-STRING). The default value is `off'. `skip-completed-text' If set to `on', this alters the default completion behavior when inserting a single match into the line. It's only active when performing completion in the middle of a word. If enabled, readline does not insert characters from the completion that match characters after point in the word being completed, so portions of the word following the cursor are not duplicated. For instance, if this is enabled, attempting completion when the cursor is after the `e' in `Makefile' will result in `Makefile' rather than `Makefilefile', assuming there is a single possible completion. The default value is `off'. `vi-cmd-mode-string' If the SHOW-MODE-IN-PROMPT variable is enabled, this string is displayed immediately before the last line of the primary prompt when vi editing mode is active and in command mode. The value is expanded like a key binding, so the standard set of meta- and control prefixes and backslash escape sequences is available. Use the `\1' and `\2' escapes to begin and end sequences of non-printing characters, which can be used to embed a terminal control sequence into the mode string. The default is `(cmd)'. `vi-ins-mode-string' If the SHOW-MODE-IN-PROMPT variable is enabled, this string is displayed immediately before the last line of the primary prompt when vi editing mode is active and in insertion mode. The value is expanded like a key binding, so the standard set of meta- and control prefixes and backslash escape sequences is available. Use the `\1' and `\2' escapes to begin and end sequences of non-printing characters, which can be used to embed a terminal control sequence into the mode string. The default is `(ins)'. `visible-stats' If set to `on', a character denoting a file's type is appended to the filename when listing possible completions. The default is `off'. Key Bindings The syntax for controlling key bindings in the init file is simple. First you need to find the name of the command that you want to change. The following sections contain tables of the command name, the default keybinding, if any, and a short description of what the command does. Once you know the name of the command, simply place on a line in the init file the name of the key you wish to bind the command to, a colon, and then the name of the command. There can be no space between the key name and the colon - that will be interpreted as part of the key name. The name of the key can be expressed in different ways, depending on what you find most comfortable. In addition to command names, readline allows keys to be bound to a string that is inserted when the key is pressed (a MACRO). KEYNAME: FUNCTION-NAME or MACRO KEYNAME is the name of a key spelled out in English. For example: Control-u: universal-argument Meta-Rubout: backward-kill-word Control-o: "> output" In the example above, `C-u' is bound to the function `universal-argument', `M-DEL' is bound to the function `backward-kill-word', and `C-o' is bound to run the macro expressed on the right hand side (that is, to insert the text `> output' into the line). A number of symbolic character names are recognized while processing this key binding syntax: DEL, ESC, ESCAPE, LFD, NEWLINE, RET, RETURN, RUBOUT, SPACE, SPC, and TAB. "KEYSEQ": FUNCTION-NAME or MACRO KEYSEQ differs from KEYNAME above in that strings denoting an entire key sequence can be specified, by placing the key sequence in double quotes. Some GNU Emacs style key escapes can be used, as in the following example, but the special character names are not recognized. "\C-u": universal-argument "\C-x\C-r": re-read-init-file "\e[11~": "Function Key 1" In the above example, `C-u' is again bound to the function `universal-argument' (just as it was in the first example), `C-x C-r' is bound to the function `re-read-init-file', and ` <[> <1> <1> <~>' is bound to insert the text `Function Key 1'. The following GNU Emacs style escape sequences are available when specifying key sequences: `\C-' control prefix `\M-' meta prefix `\e' an escape character `\\' backslash `\"' <">, a double quotation mark `\'' <'>, a single quote or apostrophe In addition to the GNU Emacs style escape sequences, a second set of backslash escapes is available: `\a' alert (bell) `\b' backspace `\d' delete `\f' form feed `\n' newline `\r' carriage return `\t' horizontal tab `\v' vertical tab `\NNN' the eight-bit character whose value is the octal value NNN (one to three digits) `\xHH' the eight-bit character whose value is the hexadecimal value HH (one or two hex digits) When entering the text of a macro, single or double quotes must be used to indicate a macro definition. Unquoted text is assumed to be a function name. In the macro body, the backslash escapes described above are expanded. Backslash will quote any other character in the macro text, including `"' and `''. For example, the following binding will make `C-x \' insert a single `\' into the line: "\C-x\\": "\\"  File: gdb.info, Node: Conditional Init Constructs, Next: Sample Init File, Prev: Readline Init File Syntax, Up: Readline Init File 33.3.2 Conditional Init Constructs ---------------------------------- Readline implements a facility similar in spirit to the conditional compilation features of the C preprocessor which allows key bindings and variable settings to be performed as the result of tests. There are four parser directives used. `$if' The `$if' construct allows bindings to be made based on the editing mode, the terminal being used, or the application using Readline. The text of the test, after any comparison operator, extends to the end of the line; unless otherwise noted, no characters are required to isolate it. `mode' The `mode=' form of the `$if' directive is used to test whether Readline is in `emacs' or `vi' mode. This may be used in conjunction with the `set keymap' command, for instance, to set bindings in the `emacs-standard' and `emacs-ctlx' keymaps only if Readline is starting out in `emacs' mode. `term' The `term=' form may be used to include terminal-specific key bindings, perhaps to bind the key sequences output by the terminal's function keys. The word on the right side of the `=' is tested against both the full name of the terminal and the portion of the terminal name before the first `-'. This allows `sun' to match both `sun' and `sun-cmd', for instance. `version' The `version' test may be used to perform comparisons against specific Readline versions. The `version' expands to the current Readline version. The set of comparison operators includes `=' (and `=='), `!=', `<=', `>=', `<', and `>'. The version number supplied on the right side of the operator consists of a major version number, an optional decimal point, and an optional minor version (e.g., `7.1'). If the minor version is omitted, it is assumed to be `0'. The operator may be separated from the string `version' and from the version number argument by whitespace. The following example sets a variable if the Readline version being used is 7.0 or newer: $if version >= 7.0 set show-mode-in-prompt on $endif `application' The APPLICATION construct is used to include application-specific settings. Each program using the Readline library sets the APPLICATION NAME, and you can test for a particular value. This could be used to bind key sequences to functions useful for a specific program. For instance, the following command adds a key sequence that quotes the current or previous word in Bash: $if Bash # Quote the current or previous word "\C-xq": "\eb\"\ef\"" $endif `variable' The VARIABLE construct provides simple equality tests for Readline variables and values. The permitted comparison operators are `=', `==', and `!='. The variable name must be separated from the comparison operator by whitespace; the operator may be separated from the value on the right hand side by whitespace. Both string and boolean variables may be tested. Boolean variables must be tested against the values ON and OFF. The following example is equivalent to the `mode=emacs' test described above: $if editing-mode == emacs set show-mode-in-prompt on $endif `$endif' This command, as seen in the previous example, terminates an `$if' command. `$else' Commands in this branch of the `$if' directive are executed if the test fails. `$include' This directive takes a single filename as an argument and reads commands and bindings from that file. For example, the following directive reads from `/etc/inputrc': $include /etc/inputrc  File: gdb.info, Node: Sample Init File, Prev: Conditional Init Constructs, Up: Readline Init File 33.3.3 Sample Init File ----------------------- Here is an example of an INPUTRC file. This illustrates key binding, variable assignment, and conditional syntax. # This file controls the behaviour of line input editing for # programs that use the GNU Readline library. Existing # programs include FTP, Bash, and GDB. # # You can re-read the inputrc file with C-x C-r. # Lines beginning with '#' are comments. # # First, include any system-wide bindings and variable # assignments from /etc/Inputrc $include /etc/Inputrc # # Set various bindings for emacs mode. set editing-mode emacs $if mode=emacs Meta-Control-h: backward-kill-word Text after the function name is ignored # # Arrow keys in keypad mode # #"\M-OD": backward-char #"\M-OC": forward-char #"\M-OA": previous-history #"\M-OB": next-history # # Arrow keys in ANSI mode # "\M-[D": backward-char "\M-[C": forward-char "\M-[A": previous-history "\M-[B": next-history # # Arrow keys in 8 bit keypad mode # #"\M-\C-OD": backward-char #"\M-\C-OC": forward-char #"\M-\C-OA": previous-history #"\M-\C-OB": next-history # # Arrow keys in 8 bit ANSI mode # #"\M-\C-[D": backward-char #"\M-\C-[C": forward-char #"\M-\C-[A": previous-history #"\M-\C-[B": next-history C-q: quoted-insert $endif # An old-style binding. This happens to be the default. TAB: complete # Macros that are convenient for shell interaction $if Bash # edit the path "\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f" # prepare to type a quoted word -- # insert open and close double quotes # and move to just after the open quote "\C-x\"": "\"\"\C-b" # insert a backslash (testing backslash escapes # in sequences and macros) "\C-x\\": "\\" # Quote the current or previous word "\C-xq": "\eb\"\ef\"" # Add a binding to refresh the line, which is unbound "\C-xr": redraw-current-line # Edit variable on current line. "\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y=" $endif # use a visible bell if one is available set bell-style visible # don't strip characters to 7 bits when reading set input-meta on # allow iso-latin1 characters to be inserted rather # than converted to prefix-meta sequences set convert-meta off # display characters with the eighth bit set directly # rather than as meta-prefixed characters set output-meta on # if there are 150 or more possible completions for a word, # ask whether or not the user wants to see all of them set completion-query-items 150 # For FTP $if Ftp "\C-xg": "get \M-?" "\C-xt": "put \M-?" "\M-.": yank-last-arg $endif  File: gdb.info, Node: Bindable Readline Commands, Next: Readline vi Mode, Prev: Readline Init File, Up: Command Line Editing 33.4 Bindable Readline Commands =============================== * Menu: * Commands For Moving:: Moving about the line. * Commands For History:: Getting at previous lines. * Commands For Text:: Commands for changing text. * Commands For Killing:: Commands for killing and yanking. * Numeric Arguments:: Specifying numeric arguments, repeat counts. * Commands For Completion:: Getting Readline to do the typing for you. * Keyboard Macros:: Saving and re-executing typed characters * Miscellaneous Commands:: Other miscellaneous commands. This section describes Readline commands that may be bound to key sequences. Command names without an accompanying key sequence are unbound by default. In the following descriptions, "point" refers to the current cursor position, and "mark" refers to a cursor position saved by the `set-mark' command. The text between the point and mark is referred to as the "region".  File: gdb.info, Node: Commands For Moving, Next: Commands For History, Up: Bindable Readline Commands 33.4.1 Commands For Moving -------------------------- `beginning-of-line (C-a)' Move to the start of the current line. `end-of-line (C-e)' Move to the end of the line. `forward-char (C-f)' Move forward a character. `backward-char (C-b)' Move back a character. `forward-word (M-f)' Move forward to the end of the next word. Words are composed of letters and digits. `backward-word (M-b)' Move back to the start of the current or previous word. Words are composed of letters and digits. `previous-screen-line ()' Attempt to move point to the same physical screen column on the previous physical screen line. This will not have the desired effect if the current Readline line does not take up more than one physical line or if point is not greater than the length of the prompt plus the screen width. `next-screen-line ()' Attempt to move point to the same physical screen column on the next physical screen line. This will not have the desired effect if the current Readline line does not take up more than one physical line or if the length of the current Readline line is not greater than the length of the prompt plus the screen width. `clear-display (M-C-l)' Clear the screen and, if possible, the terminal's scrollback buffer, then redraw the current line, leaving the current line at the top of the screen. `clear-screen (C-l)' Clear the screen, then redraw the current line, leaving the current line at the top of the screen. `redraw-current-line ()' Refresh the current line. By default, this is unbound.  File: gdb.info, Node: Commands For History, Next: Commands For Text, Prev: Commands For Moving, Up: Bindable Readline Commands 33.4.2 Commands For Manipulating The History -------------------------------------------- `accept-line (Newline or Return)' Accept the line regardless of where the cursor is. If this line is non-empty, it may be added to the history list for future recall with `add_history()'. If this line is a modified history line, the history line is restored to its original state. `previous-history (C-p)' Move `back' through the history list, fetching the previous command. `next-history (C-n)' Move `forward' through the history list, fetching the next command. `beginning-of-history (M-<)' Move to the first line in the history. `end-of-history (M->)' Move to the end of the input history, i.e., the line currently being entered. `reverse-search-history (C-r)' Search backward starting at the current line and moving `up' through the history as necessary. This is an incremental search. This command sets the region to the matched text and activates the mark. `forward-search-history (C-s)' Search forward starting at the current line and moving `down' through the history as necessary. This is an incremental search. This command sets the region to the matched text and activates the mark. `non-incremental-reverse-search-history (M-p)' Search backward starting at the current line and moving `up' through the history as necessary using a non-incremental search for a string supplied by the user. The search string may match anywhere in a history line. `non-incremental-forward-search-history (M-n)' Search forward starting at the current line and moving `down' through the history as necessary using a non-incremental search for a string supplied by the user. The search string may match anywhere in a history line. `history-search-forward ()' Search forward through the history for the string of characters between the start of the current line and the point. The search string must match at the beginning of a history line. This is a non-incremental search. By default, this command is unbound. `history-search-backward ()' Search backward through the history for the string of characters between the start of the current line and the point. The search string must match at the beginning of a history line. This is a non-incremental search. By default, this command is unbound. `history-substring-search-forward ()' Search forward through the history for the string of characters between the start of the current line and the point. The search string may match anywhere in a history line. This is a non-incremental search. By default, this command is unbound. `history-substring-search-backward ()' Search backward through the history for the string of characters between the start of the current line and the point. The search string may match anywhere in a history line. This is a non-incremental search. By default, this command is unbound. `yank-nth-arg (M-C-y)' Insert the first argument to the previous command (usually the second word on the previous line) at point. With an argument N, insert the Nth word from the previous command (the words in the previous command begin with word 0). A negative argument inserts the Nth word from the end of the previous command. Once the argument N is computed, the argument is extracted as if the `!N' history expansion had been specified. `yank-last-arg (M-. or M-_)' Insert last argument to the previous command (the last word of the previous history entry). With a numeric argument, behave exactly like `yank-nth-arg'. Successive calls to `yank-last-arg' move back through the history list, inserting the last word (or the word specified by the argument to the first call) of each line in turn. Any numeric argument supplied to these successive calls determines the direction to move through the history. A negative argument switches the direction through the history (back or forward). The history expansion facilities are used to extract the last argument, as if the `!$' history expansion had been specified. `operate-and-get-next (C-o)' Accept the current line for return to the calling application as if a newline had been entered, and fetch the next line relative to the current line from the history for editing. A numeric argument, if supplied, specifies the history entry to use instead of the current line.  File: gdb.info, Node: Commands For Text, Next: Commands For Killing, Prev: Commands For History, Up: Bindable Readline Commands 33.4.3 Commands For Changing Text --------------------------------- `end-of-file (usually C-d)' The character indicating end-of-file as set, for example, by `stty'. If this character is read when there are no characters on the line, and point is at the beginning of the line, Readline interprets it as the end of input and returns EOF. `delete-char (C-d)' Delete the character at point. If this function is bound to the same character as the tty EOF character, as `C-d' commonly is, see above for the effects. `backward-delete-char (Rubout)' Delete the character behind the cursor. A numeric argument means to kill the characters instead of deleting them. `forward-backward-delete-char ()' Delete the character under the cursor, unless the cursor is at the end of the line, in which case the character behind the cursor is deleted. By default, this is not bound to a key. `quoted-insert (C-q or C-v)' Add the next character typed to the line verbatim. This is how to insert key sequences like `C-q', for example. `tab-insert (M-)' Insert a tab character. `self-insert (a, b, A, 1, !, ...)' Insert yourself. `bracketed-paste-begin ()' This function is intended to be bound to the "bracketed paste" escape sequence sent by some terminals, and such a binding is assigned by default. It allows Readline to insert the pasted text as a single unit without treating each character as if it had been read from the keyboard. The characters are inserted as if each one was bound to `self-insert' instead of executing any editing commands. Bracketed paste sets the region (the characters between point and the mark) to the inserted text. It uses the concept of an _active mark_: when the mark is active, Readline redisplay uses the terminal's standout mode to denote the region. `transpose-chars (C-t)' Drag the character before the cursor forward over the character at the cursor, moving the cursor forward as well. If the insertion point is at the end of the line, then this transposes the last two characters of the line. Negative arguments have no effect. `transpose-words (M-t)' Drag the word before point past the word after point, moving point past that word as well. If the insertion point is at the end of the line, this transposes the last two words on the line. `upcase-word (M-u)' Uppercase the current (or following) word. With a negative argument, uppercase the previous word, but do not move the cursor. `downcase-word (M-l)' Lowercase the current (or following) word. With a negative argument, lowercase the previous word, but do not move the cursor. `capitalize-word (M-c)' Capitalize the current (or following) word. With a negative argument, capitalize the previous word, but do not move the cursor. `overwrite-mode ()' Toggle overwrite mode. With an explicit positive numeric argument, switches to overwrite mode. With an explicit non-positive numeric argument, switches to insert mode. This command affects only `emacs' mode; `vi' mode does overwrite differently. Each call to `readline()' starts in insert mode. In overwrite mode, characters bound to `self-insert' replace the text at point rather than pushing the text to the right. Characters bound to `backward-delete-char' replace the character before point with a space. By default, this command is unbound.  File: gdb.info, Node: Commands For Killing, Next: Numeric Arguments, Prev: Commands For Text, Up: Bindable Readline Commands 33.4.4 Killing And Yanking -------------------------- `kill-line (C-k)' Kill the text from point to the end of the line. With a negative numeric argument, kill backward from the cursor to the beginning of the current line. `backward-kill-line (C-x Rubout)' Kill backward from the cursor to the beginning of the current line. With a negative numeric argument, kill forward from the cursor to the end of the current line. `unix-line-discard (C-u)' Kill backward from the cursor to the beginning of the current line. `kill-whole-line ()' Kill all characters on the current line, no matter where point is. By default, this is unbound. `kill-word (M-d)' Kill from point to the end of the current word, or if between words, to the end of the next word. Word boundaries are the same as `forward-word'. `backward-kill-word (M-)' Kill the word behind point. Word boundaries are the same as `backward-word'. `shell-transpose-words (M-C-t)' Drag the word before point past the word after point, moving point past that word as well. If the insertion point is at the end of the line, this transposes the last two words on the line. Word boundaries are the same as `shell-forward-word' and `shell-backward-word'. `unix-word-rubout (C-w)' Kill the word behind point, using white space as a word boundary. The killed text is saved on the kill-ring. `unix-filename-rubout ()' Kill the word behind point, using white space and the slash character as the word boundaries. The killed text is saved on the kill-ring. `delete-horizontal-space ()' Delete all spaces and tabs around point. By default, this is unbound. `kill-region ()' Kill the text in the current region. By default, this command is unbound. `copy-region-as-kill ()' Copy the text in the region to the kill buffer, so it can be yanked right away. By default, this command is unbound. `copy-backward-word ()' Copy the word before point to the kill buffer. The word boundaries are the same as `backward-word'. By default, this command is unbound. `copy-forward-word ()' Copy the word following point to the kill buffer. The word boundaries are the same as `forward-word'. By default, this command is unbound. `yank (C-y)' Yank the top of the kill ring into the buffer at point. `yank-pop (M-y)' Rotate the kill-ring, and yank the new top. You can only do this if the prior command is `yank' or `yank-pop'.  File: gdb.info, Node: Numeric Arguments, Next: Commands For Completion, Prev: Commands For Killing, Up: Bindable Readline Commands 33.4.5 Specifying Numeric Arguments ----------------------------------- `digit-argument (M-0, M-1, ... M--)' Add this digit to the argument already accumulating, or start a new argument. `M--' starts a negative argument. `universal-argument ()' This is another way to specify an argument. If this command is followed by one or more digits, optionally with a leading minus sign, those digits define the argument. If the command is followed by digits, executing `universal-argument' again ends the numeric argument, but is otherwise ignored. As a special case, if this command is immediately followed by a character that is neither a digit nor minus sign, the argument count for the next command is multiplied by four. The argument count is initially one, so executing this function the first time makes the argument count four, a second time makes the argument count sixteen, and so on. By default, this is not bound to a key.  File: gdb.info, Node: Commands For Completion, Next: Keyboard Macros, Prev: Numeric Arguments, Up: Bindable Readline Commands 33.4.6 Letting Readline Type For You ------------------------------------ `complete ()' Attempt to perform completion on the text before point. The actual completion performed is application-specific. The default is filename completion. `possible-completions (M-?)' List the possible completions of the text before point. When displaying completions, Readline sets the number of columns used for display to the value of `completion-display-width', the value of the environment variable `COLUMNS', or the screen width, in that order. `insert-completions (M-*)' Insert all completions of the text before point that would have been generated by `possible-completions'. `menu-complete ()' Similar to `complete', but replaces the word to be completed with a single match from the list of possible completions. Repeated execution of `menu-complete' steps through the list of possible completions, inserting each match in turn. At the end of the list of completions, the bell is rung (subject to the setting of `bell-style') and the original text is restored. An argument of N moves N positions forward in the list of matches; a negative argument may be used to move backward through the list. This command is intended to be bound to , but is unbound by default. `menu-complete-backward ()' Identical to `menu-complete', but moves backward through the list of possible completions, as if `menu-complete' had been given a negative argument. `delete-char-or-list ()' Deletes the character under the cursor if not at the beginning or end of the line (like `delete-char'). If at the end of the line, behaves identically to `possible-completions'. This command is unbound by default.  File: gdb.info, Node: Keyboard Macros, Next: Miscellaneous Commands, Prev: Commands For Completion, Up: Bindable Readline Commands 33.4.7 Keyboard Macros ---------------------- `start-kbd-macro (C-x ()' Begin saving the characters typed into the current keyboard macro. `end-kbd-macro (C-x ))' Stop saving the characters typed into the current keyboard macro and save the definition. `call-last-kbd-macro (C-x e)' Re-execute the last keyboard macro defined, by making the characters in the macro appear as if typed at the keyboard. `print-last-kbd-macro ()' Print the last keboard macro defined in a format suitable for the INPUTRC file.  File: gdb.info, Node: Miscellaneous Commands, Prev: Keyboard Macros, Up: Bindable Readline Commands 33.4.8 Some Miscellaneous Commands ---------------------------------- `re-read-init-file (C-x C-r)' Read in the contents of the INPUTRC file, and incorporate any bindings or variable assignments found there. `abort (C-g)' Abort the current editing command and ring the terminal's bell (subject to the setting of `bell-style'). `do-lowercase-version (M-A, M-B, M-X, ...)' If the metafied character X is upper case, run the command that is bound to the corresponding metafied lower case character. The behavior is undefined if X is already lower case. `prefix-meta ()' Metafy the next character typed. This is for keyboards without a meta key. Typing ` f' is equivalent to typing `M-f'. `undo (C-_ or C-x C-u)' Incremental undo, separately remembered for each line. `revert-line (M-r)' Undo all changes made to this line. This is like executing the `undo' command enough times to get back to the beginning. `tilde-expand (M-~)' Perform tilde expansion on the current word. `set-mark (C-@@)' Set the mark to the point. If a numeric argument is supplied, the mark is set to that position. `exchange-point-and-mark (C-x C-x)' Swap the point with the mark. The current cursor position is set to the saved position, and the old cursor position is saved as the mark. `character-search (C-])' A character is read and point is moved to the next occurrence of that character. A negative count searches for previous occurrences. `character-search-backward (M-C-])' A character is read and point is moved to the previous occurrence of that character. A negative count searches for subsequent occurrences. `skip-csi-sequence ()' Read enough characters to consume a multi-key sequence such as those defined for keys like Home and End. Such sequences begin with a Control Sequence Indicator (CSI), usually ESC-[. If this sequence is bound to "\e[", keys producing such sequences will have no effect unless explicitly bound to a readline command, instead of inserting stray characters into the editing buffer. This is unbound by default, but usually bound to ESC-[. `insert-comment (M-#)' Without a numeric argument, the value of the `comment-begin' variable is inserted at the beginning of the current line. If a numeric argument is supplied, this command acts as a toggle: if the characters at the beginning of the line do not match the value of `comment-begin', the value is inserted, otherwise the characters in `comment-begin' are deleted from the beginning of the line. In either case, the line is accepted as if a newline had been typed. `dump-functions ()' Print all of the functions and their key bindings to the Readline output stream. If a numeric argument is supplied, the output is formatted in such a way that it can be made part of an INPUTRC file. This command is unbound by default. `dump-variables ()' Print all of the settable variables and their values to the Readline output stream. If a numeric argument is supplied, the output is formatted in such a way that it can be made part of an INPUTRC file. This command is unbound by default. `dump-macros ()' Print all of the Readline key sequences bound to macros and the strings they output. If a numeric argument is supplied, the output is formatted in such a way that it can be made part of an INPUTRC file. This command is unbound by default. `emacs-editing-mode (C-e)' When in `vi' command mode, this causes a switch to `emacs' editing mode. `vi-editing-mode (M-C-j)' When in `emacs' editing mode, this causes a switch to `vi' editing mode.  File: gdb.info, Node: Readline vi Mode, Prev: Bindable Readline Commands, Up: Command Line Editing 33.5 Readline vi Mode ===================== While the Readline library does not have a full set of `vi' editing functions, it does contain enough to allow simple editing of the line. The Readline `vi' mode behaves as specified in the POSIX standard. In order to switch interactively between `emacs' and `vi' editing modes, use the command `M-C-j' (bound to emacs-editing-mode when in `vi' mode and to vi-editing-mode in `emacs' mode). The Readline default is `emacs' mode. When you enter a line in `vi' mode, you are already placed in `insertion' mode, as if you had typed an `i'. Pressing switches you into `command' mode, where you can edit the text of the line with the standard `vi' movement keys, move to previous history lines with `k' and subsequent lines with `j', and so forth.  File: gdb.info, Node: Using History Interactively, Next: In Memoriam, Prev: Command Line Editing, Up: Top 34 Using History Interactively ****************************** This chapter describes how to use the GNU History Library interactively, from a user's standpoint. It should be considered a user's guide. For information on using the GNU History Library in your own programs, *note Programming with GNU History: (history)Programming with GNU History. * Menu: * History Interaction:: What it feels like using History as a user.  File: gdb.info, Node: History Interaction, Up: Using History Interactively 34.1 History Expansion ====================== The History library provides a history expansion feature that is similar to the history expansion provided by `csh'. This section describes the syntax used to manipulate the history information. History expansions introduce words from the history list into the input stream, making it easy to repeat commands, insert the arguments to a previous command into the current input line, or fix errors in previous commands quickly. History expansion takes place in two parts. The first is to determine which line from the history list should be used during substitution. The second is to select portions of that line for inclusion into the current one. The line selected from the history is called the "event", and the portions of that line that are acted upon are called "words". Various "modifiers" are available to manipulate the selected words. The line is broken into words in the same fashion that Bash does, so that several words surrounded by quotes are considered one word. History expansions are introduced by the appearance of the history expansion character, which is `!' by default. History expansion implements shell-like quoting conventions: a backslash can be used to remove the special handling for the next character; single quotes enclose verbatim sequences of characters, and can be used to inhibit history expansion; and characters enclosed within double quotes may be subject to history expansion, since backslash can escape the history expansion character, but single quotes may not, since they are not treated specially within double quotes. * Menu: * Event Designators:: How to specify which history line to use. * Word Designators:: Specifying which words are of interest. * Modifiers:: Modifying the results of substitution.  File: gdb.info, Node: Event Designators, Next: Word Designators, Up: History Interaction 34.1.1 Event Designators ------------------------ An event designator is a reference to a command line entry in the history list. Unless the reference is absolute, events are relative to the current position in the history list. `!' Start a history substitution, except when followed by a space, tab, the end of the line, or `='. `!N' Refer to command line N. `!-N' Refer to the command N lines back. `!!' Refer to the previous command. This is a synonym for `!-1'. `!STRING' Refer to the most recent command preceding the current position in the history list starting with STRING. `!?STRING[?]' Refer to the most recent command preceding the current position in the history list containing STRING. The trailing `?' may be omitted if the STRING is followed immediately by a newline. If STRING is missing, the string from the most recent search is used; it is an error if there is no previous search string. `^STRING1^STRING2^' Quick Substitution. Repeat the last command, replacing STRING1 with STRING2. Equivalent to `!!:s^STRING1^STRING2^'. `!#' The entire command line typed so far.  File: gdb.info, Node: Word Designators, Next: Modifiers, Prev: Event Designators, Up: History Interaction 34.1.2 Word Designators ----------------------- Word designators are used to select desired words from the event. A `:' separates the event specification from the word designator. It may be omitted if the word designator begins with a `^', `$', `*', `-', or `%'. Words are numbered from the beginning of the line, with the first word being denoted by 0 (zero). Words are inserted into the current line separated by single spaces. For example, `!!' designates the preceding command. When you type this, the preceding command is repeated in toto. `!!:$' designates the last argument of the preceding command. This may be shortened to `!$'. `!fi:2' designates the second argument of the most recent command starting with the letters `fi'. Here are the word designators: `0 (zero)' The `0'th word. For many applications, this is the command word. `N' The Nth word. `^' The first argument; that is, word 1. `$' The last argument. `%' The first word matched by the most recent `?STRING?' search, if the search string begins with a character that is part of a word. `X-Y' A range of words; `-Y' abbreviates `0-Y'. `*' All of the words, except the `0'th. This is a synonym for `1-$'. It is not an error to use `*' if there is just one word in the event; the empty string is returned in that case. `X*' Abbreviates `X-$' `X-' Abbreviates `X-$' like `X*', but omits the last word. If `x' is missing, it defaults to 0. If a word designator is supplied without an event specification, the previous command is used as the event.  File: gdb.info, Node: Modifiers, Prev: Word Designators, Up: History Interaction 34.1.3 Modifiers ---------------- After the optional word designator, you can add a sequence of one or more of the following modifiers, each preceded by a `:'. These modify, or edit, the word or words selected from the history event. `h' Remove a trailing pathname component, leaving only the head. `t' Remove all leading pathname components, leaving the tail. `r' Remove a trailing suffix of the form `.SUFFIX', leaving the basename. `e' Remove all but the trailing suffix. `p' Print the new command but do not execute it. `s/OLD/NEW/' Substitute NEW for the first occurrence of OLD in the event line. Any character may be used as the delimiter in place of `/'. The delimiter may be quoted in OLD and NEW with a single backslash. If `&' appears in NEW, it is replaced by OLD. A single backslash will quote the `&'. If OLD is null, it is set to the last OLD substituted, or, if no previous history substitutions took place, the last STRING in a !?STRING`[?]' search. If NEW is is null, each matching OLD is deleted. The final delimiter is optional if it is the last character on the input line. `&' Repeat the previous substitution. `g' `a' Cause changes to be applied over the entire event line. Used in conjunction with `s', as in `gs/OLD/NEW/', or with `&'. `G' Apply the following `s' or `&' modifier once to each word in the event.  File: gdb.info, Node: In Memoriam, Next: Formatting Documentation, Prev: Using History Interactively, Up: Top Appendix A In Memoriam ********************** The GDB project mourns the loss of the following long-time contributors: `Fred Fish' Fred was a long-standing contributor to GDB (1991-2006), and to Free Software in general. Outside of GDB, he was known in the Amiga world for his series of Fish Disks, and the GeekGadget project. `Michael Snyder' Michael was one of the Global Maintainers of the GDB project, with contributions recorded as early as 1996, until 2011. In addition to his day to day participation, he was a large driving force behind adding Reverse Debugging to GDB. Beyond their technical contributions to the project, they were also enjoyable members of the Free Software Community. We will miss them.  File: gdb.info, Node: Formatting Documentation, Next: Installing GDB, Prev: In Memoriam, Up: Top Appendix B Formatting Documentation *********************************** The GDB 4 release includes an already-formatted reference card, ready for printing with PostScript or Ghostscript, in the `gdb' subdirectory of the main source directory(1). If you can use PostScript or Ghostscript with your printer, you can print the reference card immediately with `refcard.ps'. The release also includes the source for the reference card. You can format it, using TeX, by typing: make refcard.dvi The GDB reference card is designed to print in "landscape" mode on US "letter" size paper; that is, on a sheet 11 inches wide by 8.5 inches high. You will need to specify this form of printing as an option to your DVI output program. All the documentation for GDB comes as part of the machine-readable distribution. The documentation is written in Texinfo format, which is a documentation system that uses a single source file to produce both on-line information and a printed manual. You can use one of the Info formatting commands to create the on-line version of the documentation and TeX (or `texi2roff') to typeset the printed version. GDB includes an already formatted copy of the on-line Info version of this manual in the `gdb' subdirectory. The main Info file is `gdb-15.1/gdb/gdb.info', and it refers to subordinate files matching `gdb.info*' in the same directory. If necessary, you can print out these files, or read them with any editor; but they are easier to read using the `info' subsystem in GNU Emacs or the standalone `info' program, available as part of the GNU Texinfo distribution. If you want to format these Info files yourself, you need one of the Info formatting programs, such as `texinfo-format-buffer' or `makeinfo'. If you have `makeinfo' installed, and are in the top level GDB source directory (`gdb-15.1', in the case of version 15.1), you can make the Info file by typing: cd gdb make gdb.info If you want to typeset and print copies of this manual, you need TeX, a program to print its DVI output files, and `texinfo.tex', the Texinfo definitions file. TeX is a typesetting program; it does not print files directly, but produces output files called DVI files. To print a typeset document, you need a program to print DVI files. If your system has TeX installed, chances are it has such a program. The precise command to use depends on your system; `lpr -d' is common; another (for PostScript devices) is `dvips'. The DVI print command may require a file name without any extension or a `.dvi' extension. TeX also requires a macro definitions file called `texinfo.tex'. This file tells TeX how to typeset a document written in Texinfo format. On its own, TeX cannot either read or typeset a Texinfo file. `texinfo.tex' is distributed with GDB and is located in the `gdb-VERSION-NUMBER/texinfo' directory. If you have TeX and a DVI printer program installed, you can typeset and print this manual. First switch to the `gdb' subdirectory of the main source directory (for example, to `gdb-15.1/gdb') and type: make gdb.dvi Then give `gdb.dvi' to your DVI printing program. ---------- Footnotes ---------- (1) In `gdb-15.1/gdb/refcard.ps' of the version 15.1 release.  File: gdb.info, Node: Installing GDB, Next: Maintenance Commands, Prev: Formatting Documentation, Up: Top Appendix C Installing GDB ************************* * Menu: * Requirements:: Requirements for building GDB * Running Configure:: Invoking the GDB `configure' script * Separate Objdir:: Compiling GDB in another directory * Config Names:: Specifying names for hosts and targets * Configure Options:: Summary of options for configure * System-wide configuration:: Having a system-wide init file  File: gdb.info, Node: Requirements, Next: Running Configure, Up: Installing GDB C.1 Requirements for Building GDB ================================= Building GDB requires various tools and packages to be available. Other packages will be used only if they are found. Tools/Packages Necessary for Building GDB ========================================= C++17 compiler GDB is written in C++17. It should be buildable with any recent C++17 compiler, e.g. GCC. GNU make GDB's build system relies on features only found in the GNU make program. Other variants of `make' will not work. Libraries The following libraries are mandatory for building GDB. The `configure' script searches for each of these libraries in several standard locations; if some library is installed in an unusual place, you can use either the `--with-LIB' `configure' option to specify its installation directory, or the two separate options `---with-LIBRARY-include' (to specify the location of its header files) and `--with-LIBRARY-lib' (to specify the location of its libraries). For example, for the GMP library, the 3 options are `--with-gmp', `--with-gmp-include', and `--with-gmp-lib'. *Note Configure Options::. We mention below the home site of each library, so that you could download and install them if your system doesn't already include them. GMP (The GNU Multiple Precision arithmetic library) GDB uses GMP to perform some of its extended-precision arithmetic. The latest version of GMP is available from `https://gmplib.org/'. MPFR (The GNU Multiple-precision floating-point library) GDB uses MPFR to emulate the target floating-point arithmetic during expression evaluation, if the target uses different floating-point formats than the host. The latest version of MPFR is available from `http://www.mpfr.org'. Tools/Packages Optional for Building GDB ======================================== The tools/packages and libraries listed below are optional; GDB can be build without them, at the expense of some run-time functionality that will be missing. As above, we list the home sites for each package/library, and the command-line options supported by the `configure' script to specify their installation directories if they are non-standard. In addition, for each package you can use the option `--with-PACKAGE' to force GDB to be compiled with the named PACKAGE, and `--without-PACKAGE' to disable building with it even if it is available. *Note Configure Options::, for detailed description of the options to `configure'. Python GDB can be scripted using Python language. *Note Python::. The latest version is available from `https://www.python.org/downloads/'. Use the `--with-python=DIR' to specify the non-standard directory where Python is installed. Guile GDB can also be scripted using GNU Guile. *Note Guile::. The latest version can be found on `https://www.gnu.org/software/guile/download/'. If you have more than one version of Guile installed, use the `--with-guile=GUILE-VERSION' to specify the Guile version to include in the build. Expat If available, GDB uses the Expat library for parsing XML files. GDB uses XML files for the following functionalities: * Remote protocol memory maps (*note Memory Map Format::) * Target descriptions (*note Target Descriptions::) * Remote shared library lists (*Note Library List Format::, or alternatively *note Library List Format for SVR4 Targets::) * MS-Windows shared libraries (*note Shared Libraries::) * Traceframe info (*note Traceframe Info Format::) * Branch trace (*note Branch Trace Format::, *note Branch Trace Configuration Format::) The latest version of Expat is available from `http://expat.sourceforge.net'. Use the `--with-libexpat-prefix' to specify non-standard installation places for Expat. iconv GDB's features related to character sets (*note Character Sets::) require a functioning `iconv' implementation. If you are on a GNU system, then this is provided by the GNU C Library. Some other systems also provide a working `iconv'. Use the option `--with-iconv-bin' to specify where to find the `iconv' program. On systems without `iconv', you can install the GNU Libiconv library; its latest version can be found on `https://ftp.gnu.org/pub/gnu/libiconv/' if your system doesn't provide it. Use the `--with-libiconv-prefix' option to `configure' to specify non-standard installation place for it. Alternatively, GDB's top-level `configure' and `Makefile' will arrange to build Libiconv if a directory named `libiconv' appears in the top-most source directory. If Libiconv is built this way, and if the operating system does not provide a suitable `iconv' implementation, then the just-built library will automatically be used by GDB. One easy way to set this up is to download GNU Libiconv, unpack it inside the top-level directory of the GDB source tree, and then rename the directory holding the Libiconv source code to `libiconv'. lzma GDB can support debugging sections that are compressed with the LZMA library. *Note MiniDebugInfo::. If this library is not included with your operating system, you can find it in the xz package at `http://tukaani.org/xz/'. Use the `--with-liblzma-prefix' option to specify its non-standard location. zlib GDB will use the `zlib' library, if available, to read compressed debug sections. Some linkers, such as GNU `gold', are capable of producing binaries with compressed debug sections. If GDB is compiled with `zlib', it will be able to read the debug information in such binaries. The `zlib' library is likely included with your operating system distribution; if it is not, you can get the latest version from `http://zlib.net'.  File: gdb.info, Node: Running Configure, Next: Separate Objdir, Prev: Requirements, Up: Installing GDB C.2 Invoking the GDB `configure' Script ======================================= GDB comes with a `configure' script that automates the process of preparing GDB for installation; you can then use `make' to build the `gdb' program. The GDB distribution includes all the source code you need for GDB in a single directory, whose name is usually composed by appending the version number to `gdb'. For example, the GDB version 15.1 distribution is in the `gdb-15.1' directory. That directory contains: `gdb-15.1/configure (and supporting files)' script for configuring GDB and all its supporting libraries `gdb-15.1/gdb' the source specific to GDB itself `gdb-15.1/bfd' source for the Binary File Descriptor library `gdb-15.1/include' GNU include files `gdb-15.1/libiberty' source for the `-liberty' free software library `gdb-15.1/opcodes' source for the library of opcode tables and disassemblers `gdb-15.1/readline' source for the GNU command-line interface There may be other subdirectories as well. The simplest way to configure and build GDB is to run `configure' from the `gdb-VERSION-NUMBER' source directory, which in this example is the `gdb-15.1' directory. First switch to the `gdb-VERSION-NUMBER' source directory if you are not already in it; then run `configure'. Pass the identifier for the platform on which GDB will run as an argument. For example: cd gdb-15.1 ./configure make Running `configure' and then running `make' builds the included supporting libraries, then `gdb' itself. The configured source files, and the binaries, are left in the corresponding source directories. `configure' is a Bourne-shell (`/bin/sh') script; if your system does not recognize this automatically when you run a different shell, you may need to run `sh' on it explicitly: sh configure You should run the `configure' script from the top directory in the source tree, the `gdb-VERSION-NUMBER' directory. If you run `configure' from one of the subdirectories, you will configure only that subdirectory. That is usually not what you want. In particular, if you run the first `configure' from the `gdb' subdirectory of the `gdb-VERSION-NUMBER' directory, you will omit the configuration of `bfd', `readline', and other sibling directories of the `gdb' subdirectory. This leads to build errors about missing include files such as `bfd/bfd.h'. You can install `GDB' anywhere. The best way to do this is to pass the `--prefix' option to `configure', and then install it with `make install'.  File: gdb.info, Node: Separate Objdir, Next: Config Names, Prev: Running Configure, Up: Installing GDB C.3 Compiling GDB in Another Directory ====================================== If you want to run GDB versions for several host or target machines, you need a different `gdb' compiled for each combination of host and target. `configure' is designed to make this easy by allowing you to generate each configuration in a separate subdirectory, rather than in the source directory. If your `make' program handles the `VPATH' feature (GNU `make' does), running `make' in each of these directories builds the `gdb' program specified there. To build `gdb' in a separate directory, run `configure' with the `--srcdir' option to specify where to find the source. (You also need to specify a path to find `configure' itself from your working directory. If the path to `configure' would be the same as the argument to `--srcdir', you can leave out the `--srcdir' option; it is assumed.) For example, with version 15.1, you can build GDB in a separate directory for a Sun 4 like this: cd gdb-15.1 mkdir ../gdb-sun4 cd ../gdb-sun4 ../gdb-15.1/configure make When `configure' builds a configuration using a remote source directory, it creates a tree for the binaries with the same structure (and using the same names) as the tree under the source directory. In the example, you'd find the Sun 4 library `libiberty.a' in the directory `gdb-sun4/libiberty', and GDB itself in `gdb-sun4/gdb'. Make sure that your path to the `configure' script has just one instance of `gdb' in it. If your path to `configure' looks like `../gdb-15.1/gdb/configure', you are configuring only one subdirectory of GDB, not the whole package. This leads to build errors about missing include files such as `bfd/bfd.h'. One popular reason to build several GDB configurations in separate directories is to configure GDB for cross-compiling (where GDB runs on one machine--the "host"--while debugging programs that run on another machine--the "target"). You specify a cross-debugging target by giving the `--target=TARGET' option to `configure'. When you run `make' to build a program or library, you must run it in a configured directory--whatever directory you were in when you called `configure' (or one of its subdirectories). The `Makefile' that `configure' generates in each source directory also runs recursively. If you type `make' in a source directory such as `gdb-15.1' (or in a separate configured directory configured with `--srcdir=DIRNAME/gdb-15.1'), you will build all the required libraries, and then build GDB. When you have multiple hosts or targets configured in separate directories, you can run `make' on them in parallel (for example, if they are NFS-mounted on each of the hosts); they will not interfere with each other.  File: gdb.info, Node: Config Names, Next: Configure Options, Prev: Separate Objdir, Up: Installing GDB C.4 Specifying Names for Hosts and Targets ========================================== The specifications used for hosts and targets in the `configure' script are based on a three-part naming scheme, but some short predefined aliases are also supported. The full naming scheme encodes three pieces of information in the following pattern: ARCHITECTURE-VENDOR-OS For example, you can use the alias `sun4' as a HOST argument, or as the value for TARGET in a `--target=TARGET' option. The equivalent full name is `sparc-sun-sunos4'. The `configure' script accompanying GDB does not provide any query facility to list all supported host and target names or aliases. `configure' calls the Bourne shell script `config.sub' to map abbreviations to full names; you can read the script, if you wish, or you can use it to test your guesses on abbreviations--for example: % sh config.sub i386-linux i386-pc-linux-gnu % sh config.sub alpha-linux alpha-unknown-linux-gnu % sh config.sub hp9k700 hppa1.1-hp-hpux % sh config.sub sun4 sparc-sun-sunos4.1.1 % sh config.sub sun3 m68k-sun-sunos4.1.1 % sh config.sub i986v Invalid configuration `i986v': machine `i986v' not recognized `config.sub' is also distributed in the GDB source directory (`gdb-15.1', for version 15.1).  File: gdb.info, Node: Configure Options, Next: System-wide configuration, Prev: Config Names, Up: Installing GDB C.5 `configure' Options ======================= Here is a summary of the `configure' options and arguments that are most often useful for building GDB. `configure' also has several other options not listed here. *Note Running configure Scripts: (autoconf)Running configure Scripts, for a full explanation of `configure'. configure [--help] [--prefix=DIR] [--exec-prefix=DIR] [--srcdir=DIRNAME] [--target=TARGET] You may introduce options with a single `-' rather than `--' if you prefer; but you may abbreviate option names if you use `--'. `--help' Display a quick summary of how to invoke `configure'. `--prefix=DIR' Configure the source to install programs and files under directory `DIR'. `--exec-prefix=DIR' Configure the source to install programs under directory `DIR'. `--srcdir=DIRNAME' Use this option to make configurations in directories separate from the GDB source directories. Among other things, you can use this to build (or maintain) several configurations simultaneously, in separate directories. `configure' writes configuration-specific files in the current directory, but arranges for them to use the source in the directory DIRNAME. `configure' creates directories under the working directory in parallel to the source directories below DIRNAME. `--target=TARGET' Configure GDB for cross-debugging programs running on the specified TARGET. Without this option, GDB is configured to debug programs that run on the same machine (HOST) as GDB itself. There is no convenient way to generate a list of all available targets. Also see the `--enable-targets' option, below. There are many other options that are specific to GDB. This lists just the most common ones; there are some very specialized options not described here. `--enable-targets=[TARGET]...' `--enable-targets=all' Configure GDB for cross-debugging programs running on the specified list of targets. The special value `all' configures GDB for debugging programs running on any target it supports. `--with-gdb-datadir=PATH' Set the GDB-specific data directory. GDB will look here for certain supporting files or scripts. This defaults to the `gdb' subdirectory of `datadir' (which can be set using `--datadir'). `--with-relocated-sources=DIR' Sets up the default source path substitution rule so that directory names recorded in debug information will be automatically adjusted for any directory under DIR. DIR should be a subdirectory of GDB's configured prefix, the one mentioned in the `--prefix' or `--exec-prefix' options to configure. This option is useful if GDB is supposed to be moved to a different place after it is built. `--enable-64-bit-bfd' Enable 64-bit support in BFD on 32-bit hosts. `--disable-gdbmi' Build GDB without the GDB/MI machine interface (*note GDB/MI::). `--enable-tui' Build GDB with the text-mode full-screen user interface (TUI). Requires a curses library (ncurses and cursesX are also supported). `--with-curses' Use the curses library instead of the termcap library, for text-mode terminal operations. `--with-debuginfod' Build GDB with `libdebuginfod', the `debuginfod' client library. Used to automatically fetch ELF, DWARF and source files from `debuginfod' servers using build IDs associated with any missing files. Enabled by default if `libdebuginfod' is installed and found at configure time. For more information regarding `debuginfod' see *Note Debuginfod::. `--with-libunwind-ia64' Use the libunwind library for unwinding function call stack on ia64 target platforms. See `http://www.nongnu.org/libunwind/index.html' for details. `--with-system-readline' Use the readline library installed on the host, rather than the library supplied as part of GDB. Readline 7 or newer is required; this is enforced by the build system. `--with-system-zlib' Use the zlib library installed on the host, rather than the library supplied as part of GDB. `--with-expat' Build GDB with Expat, a library for XML parsing. (Done by default if libexpat is installed and found at configure time.) This library is used to read XML files supplied with GDB. If it is unavailable, some features, such as remote protocol memory maps, target descriptions, and shared library lists, that are based on XML files, will not be available in GDB. If your host does not have libexpat installed, you can get the latest version from `http://expat.sourceforge.net'. `--with-libiconv-prefix[=DIR]' Build GDB with GNU libiconv, a character set encoding conversion library. This is not done by default, as on GNU systems the `iconv' that is built in to the C library is sufficient. If your host does not have a working `iconv', you can get the latest version of GNU iconv from `https://www.gnu.org/software/libiconv/'. GDB's build system also supports building GNU libiconv as part of the overall build. *Note Requirements::. `--with-lzma' Build GDB with LZMA, a compression library. (Done by default if liblzma is installed and found at configure time.) LZMA is used by GDB's "mini debuginfo" feature, which is only useful on platforms using the ELF object file format. If your host does not have liblzma installed, you can get the latest version from `https://tukaani.org/xz/'. `--with-python[=PYTHON]' Build GDB with Python scripting support. (Done by default if libpython is present and found at configure time.) Python makes GDB scripting much more powerful than the restricted CLI scripting language. If your host does not have Python installed, you can find it on `http://www.python.org/download/'. The oldest version of Python supported by GDB is 3.0.1. The optional argument PYTHON is used to find the Python headers and libraries. It can be either the name of a Python executable, or the name of the directory in which Python is installed. `--with-guile[=GUILE]' Build GDB with GNU Guile scripting support. (Done by default if libguile is present and found at configure time.) If your host does not have Guile installed, you can find it at `https://www.gnu.org/software/guile/'. The optional argument GUILE can be a version number, which will cause `configure' to try to use that version of Guile; or the file name of a `pkg-config' executable, which will be queried to find the information needed to compile and link against Guile. `--without-included-regex' Don't use the regex library included with GDB (as part of the libiberty library). This is the default on hosts with version 2 of the GNU C library. `--with-sysroot=DIR' Use DIR as the default system root directory for libraries whose file names begin with `/lib'' or `/usr/lib''. (The value of DIR can be modified at run time by using the `set sysroot' command.) If DIR is under the GDB configured prefix (set with `--prefix' or `--exec-prefix options', the default system root will be automatically adjusted if and when GDB is moved to a different location. `--with-system-gdbinit=FILE' Configure GDB to automatically load a system-wide init file. FILE should be an absolute file name. If FILE is in a directory under the configured prefix, and GDB is moved to another location after being built, the location of the system-wide init file will be adjusted accordingly. `--with-system-gdbinit-dir=DIRECTORY' Configure GDB to automatically load init files from a system-wide directory. DIRECTORY should be an absolute directory name. If DIRECTORY is in a directory under the configured prefix, and GDB is moved to another location after being built, the location of the system-wide init directory will be adjusted accordingly. `--enable-build-warnings' When building the GDB sources, ask the compiler to warn about any code which looks even vaguely suspicious. It passes many different warning flags, depending on the exact version of the compiler you are using. `--enable-werror' Treat compiler warnings as errors. It adds the `-Werror' flag to the compiler, which will fail the compilation if the compiler outputs any warning messages. `--enable-ubsan' Enable the GCC undefined behavior sanitizer. This is disabled by default, but passing `--enable-ubsan=yes' or `--enable-ubsan=auto' to `configure' will enable it. The undefined behavior sanitizer checks for C++ undefined behavior. It has a performance cost, so if you are looking at GDB's performance, you should disable it. The undefined behavior sanitizer was first introduced in GCC 4.9.  File: gdb.info, Node: System-wide configuration, Prev: Configure Options, Up: Installing GDB C.6 System-wide configuration and settings ========================================== GDB can be configured to have a system-wide init file and a system-wide init file directory; this file and files in that directory (if they have a recognized file extension) will be read and executed at startup (*note What GDB does during startup: Startup.). Here are the corresponding configure options: `--with-system-gdbinit=FILE' Specify that the default location of the system-wide init file is FILE. `--with-system-gdbinit-dir=DIRECTORY' Specify that the default location of the system-wide init file directory is DIRECTORY. If GDB has been configured with the option `--prefix=$prefix', they may be subject to relocation. Two possible cases: * If the default location of this init file/directory contains `$prefix', it will be subject to relocation. Suppose that the configure options are `--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit'; if GDB is moved from `$prefix' to `$install', the system init file is looked for as `$install/etc/gdbinit' instead of `$prefix/etc/gdbinit'. * By contrast, if the default location does not contain the prefix, it will not be relocated. E.g. if GDB has been configured with `--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit', then GDB will always look for `/usr/share/gdb/gdbinit', wherever GDB is installed. If the configured location of the system-wide init file (as given by the `--with-system-gdbinit' option at configure time) is in the data-directory (as specified by `--with-gdb-datadir' at configure time) or in one of its subdirectories, then GDB will look for the system-wide init file in the directory specified by the `--data-directory' command-line option. Note that the system-wide init file is only read once, during GDB initialization. If the data-directory is changed after GDB has started with the `set data-directory' command, the file will not be reread. This applies similarly to the system-wide directory specified in `--with-system-gdbinit-dir'. Any supported scripting language can be used for these init files, as long as the file extension matches the scripting language. To be interpreted as regular GDB commands, the files needs to have a `.gdb' extension. * Menu: * System-wide Configuration Scripts:: Installed System-wide Configuration Scripts  File: gdb.info, Node: System-wide Configuration Scripts, Up: System-wide configuration C.6.1 Installed System-wide Configuration Scripts ------------------------------------------------- The `system-gdbinit' directory, located inside the data-directory (as specified by `--with-gdb-datadir' at configure time) contains a number of scripts which can be used as system-wide init files. To automatically source those scripts at startup, GDB should be configured with `--with-system-gdbinit'. Otherwise, any user should be able to source them by hand as needed. The following scripts are currently available: * `elinos.py' This script is useful when debugging a program on an ELinOS target. It takes advantage of the environment variables defined in a standard ELinOS environment in order to determine the location of the system shared libraries, and then sets the `solib-absolute-prefix' and `solib-search-path' variables appropriately. * `wrs-linux.py' This script is useful when debugging a program on a target running Wind River Linux. It expects the `ENV_PREFIX' to be set to the host-side sysroot used by the target system.  File: gdb.info, Node: Maintenance Commands, Next: Remote Protocol, Prev: Installing GDB, Up: Top Appendix D Maintenance Commands ******************************* In addition to commands intended for GDB users, GDB includes a number of commands intended for GDB developers, that are not documented elsewhere in this manual. These commands are provided here for reference. (For commands that turn on debugging messages, see *Note Debugging Output::.) `maint agent [-at LINESPEC,] EXPRESSION' `maint agent-eval [-at LINESPEC,] EXPRESSION' Translate the given EXPRESSION into remote agent bytecodes. This command is useful for debugging the Agent Expression mechanism (*note Agent Expressions::). The `agent' version produces an expression useful for data collection, such as by tracepoints, while `maint agent-eval' produces an expression that evaluates directly to a result. For instance, a collection expression for `globa + globb' will include bytecodes to record four bytes of memory at each of the addresses of `globa' and `globb', while discarding the result of the addition, while an evaluation expression will do the addition and return the sum. If `-at' is given, generate remote agent bytecode for all the addresses to which LINESPEC resolves (*note Linespec Locations::). If not, generate remote agent bytecode for current frame PC address. `maint agent-printf FORMAT,EXPR,...' Translate the given format string and list of argument expressions into remote agent bytecodes and display them as a disassembled list. This command is useful for debugging the agent version of dynamic printf (*note Dynamic Printf::). `maint info breakpoints' Using the same format as `info breakpoints', display both the breakpoints you've set explicitly, and those GDB is using for internal purposes. Internal breakpoints are shown with negative breakpoint numbers. The type column identifies what kind of breakpoint is shown: `breakpoint' Normal, explicitly set breakpoint. `watchpoint' Normal, explicitly set watchpoint. `longjmp' Internal breakpoint, used to handle correctly stepping through `longjmp' calls. `longjmp resume' Internal breakpoint at the target of a `longjmp'. `until' Temporary internal breakpoint used by the GDB `until' command. `finish' Temporary internal breakpoint used by the GDB `finish' command. `shlib events' Shared library events. `maint info btrace' Pint information about raw branch tracing data. `maint btrace packet-history' Print the raw branch trace packets that are used to compute the execution history for the `record btrace' command. Both the information and the format in which it is printed depend on the btrace recording format. `bts' For the BTS recording format, print a list of blocks of sequential code. For each block, the following information is printed: Block number Newer blocks have higher numbers. The oldest block has number zero. Lowest `PC' Highest `PC' `pt' For the Intel Processor Trace recording format, print a list of Intel Processor Trace packets. For each packet, the following information is printed: Packet number Newer packets have higher numbers. The oldest packet has number zero. Trace offset The packet's offset in the trace stream. Packet opcode and payload `maint btrace clear-packet-history' Discards the cached packet history printed by the `maint btrace packet-history' command. The history will be computed again when needed. `maint btrace clear' Discard the branch trace data. The data will be fetched anew and the branch trace will be recomputed when needed. This implicitly truncates the branch trace to a single branch trace buffer. When updating branch trace incrementally, the branch trace available to GDB may be bigger than a single branch trace buffer. `maint set btrace pt skip-pad' `maint show btrace pt skip-pad' Control whether GDB will skip PAD packets when computing the packet history. `maint info jit' Print information about JIT code objects loaded in the current inferior. `maint info python-disassemblers' This command is defined within the `gdb.disassembler' Python module (*note Disassembly In Python::), and will only be present after that module has been imported. To force the module to be imported do the following: `maint info linux-lwps' Print information about LWPs under control of the Linux native target. (gdb) python import gdb.disassembler This command lists all the architectures for which a disassembler is currently registered, and the name of the disassembler. If a disassembler is registered for all architectures, then this is listed last against the `GLOBAL' architecture. If one of the disassemblers would be selected for the architecture of the current inferior, then this disassembler will be marked. The following example shows a situation in which two disassemblers are registered, initially the `i386' disassembler matches the current architecture, then the architecture is changed, now the `GLOBAL' disassembler matches. (gdb) show architecture The target architecture is set to "auto" (currently "i386"). (gdb) maint info python-disassemblers Architecture Disassember Name i386 Disassembler_1 (Matches current architecture) GLOBAL Disassembler_2 (gdb) set architecture arm The target architecture is set to "arm". (gdb) maint info python-disassemblers quit Architecture Disassember Name i386 Disassembler_1 GLOBAL Disassembler_2 (Matches current architecture) `set displaced-stepping' `show displaced-stepping' Control whether or not GDB will do "displaced stepping" if the target supports it. Displaced stepping is a way to single-step over breakpoints without removing them from the inferior, by executing an out-of-line copy of the instruction that was originally at the breakpoint location. It is also known as out-of-line single-stepping. `set displaced-stepping on' If the target architecture supports it, GDB will use displaced stepping to step over breakpoints. `set displaced-stepping off' GDB will not use displaced stepping to step over breakpoints, even if such is supported by the target architecture. `set displaced-stepping auto' This is the default mode. GDB will use displaced stepping only if non-stop mode is active (*note Non-Stop Mode::) and the target architecture supports displaced stepping. `maint check-psymtabs' Check the consistency of currently expanded psymtabs versus symtabs. Use this to check, for example, whether a symbol is in one but not the other. `maint check-symtabs' Check the consistency of currently expanded symtabs. `maint expand-symtabs [REGEXP]' Expand symbol tables. If REGEXP is specified, only expand symbol tables for file names matching REGEXP. `maint set catch-demangler-crashes [on|off]' `maint show catch-demangler-crashes' Control whether GDB should attempt to catch crashes in the symbol name demangler. The default is to attempt to catch crashes. If enabled, the first time a crash is caught, a core file is created, the offending symbol is displayed and the user is presented with the option to terminate the current session. `maint cplus first_component NAME' Print the first C++ class/namespace component of NAME. `maint cplus namespace' Print the list of possible C++ namespaces. `maint deprecate COMMAND [REPLACEMENT]' `maint undeprecate COMMAND' Deprecate or undeprecate the named COMMAND. Deprecated commands cause GDB to issue a warning when you use them. The optional argument REPLACEMENT says which newer command should be used in favor of the deprecated one; if it is given, GDB will mention the replacement as part of the warning. `maint dump-me' Cause a fatal signal in the debugger and force it to dump its core. This is supported only on systems which support aborting a program with the `SIGQUIT' signal. `maint internal-error [MESSAGE-TEXT]' `maint internal-warning [MESSAGE-TEXT]' `maint demangler-warning [MESSAGE-TEXT]' Cause GDB to call the internal function `internal_error', `internal_warning' or `demangler_warning' and hence behave as though an internal problem has been detected. In addition to reporting the internal problem, these functions give the user the opportunity to either quit GDB or (for `internal_error' and `internal_warning') create a core file of the current GDB session. These commands take an optional parameter MESSAGE-TEXT that is used as the text of the error or warning message. Here's an example of using `internal-error': (gdb) maint internal-error testing, 1, 2 .../maint.c:121: internal-error: testing, 1, 2 A problem internal to GDB has been detected. Further debugging may prove unreliable. Quit this debugging session? (y or n) n Create a core file? (y or n) n (gdb) `maint set debuginfod download-sections' `maint set debuginfod download-sections [on|off]' `maint show debuginfod download-sections' Controls whether GDB will attempt to download individual ELF/DWARF sections from `debuginfod'. If disabled, only whole debug info files will be downloaded; this could result in GDB downloading larger amounts of data. `maint set internal-error ACTION [ask|yes|no]' `maint show internal-error ACTION' `maint set internal-warning ACTION [ask|yes|no]' `maint show internal-warning ACTION' `maint set demangler-warning ACTION [ask|yes|no]' `maint show demangler-warning ACTION' When GDB reports an internal problem (error or warning) it gives the user the opportunity to both quit GDB and create a core file of the current GDB session. These commands let you override the default behaviour for each particular ACTION, described in the table below. `quit' You can specify that GDB should always (yes) or never (no) quit. The default is to ask the user what to do. `corefile' You can specify that GDB should always (yes) or never (no) create a core file. The default is to ask the user what to do. Note that there is no `corefile' option for `demangler-warning': demangler warnings always create a core file and this cannot be disabled. `maint set internal-error backtrace [on|off]' `maint show internal-error backtrace' `maint set internal-warning backtrace [on|off]' `maint show internal-warning backtrace' When GDB reports an internal problem (error or warning) it is possible to have a backtrace of GDB printed to the standard error stream. This is `on' by default for `internal-error' and `off' by default for `internal-warning'. `maint packet TEXT' If GDB is talking to an inferior via the serial protocol, then this command sends the string TEXT to the inferior, and displays the response packet. GDB supplies the initial `$' character, the terminating `#' character, and the checksum. Any non-printable characters in the reply are printed as escaped hex, e.g. `\x00', `\x01', etc. `maint print architecture [FILE]' Print the entire architecture configuration. The optional argument FILE names the file where the output goes. `maint print c-tdesc [-single-feature] [FILE]' Print the target description (*note Target Descriptions::) as a C source file. By default, the target description is for the current target, but if the optional argument FILE is provided, that file is used to produce the description. The FILE should be an XML document, of the form described in *Note Target Description Format::. The created source file is built into GDB when GDB is built again. This command is used by developers after they add or modify XML target descriptions. When the optional flag `-single-feature' is provided then the target description being processed (either the default, or from FILE) must only contain a single feature. The source file produced is different in this case. `maint print xml-tdesc [FILE]' Print the target description (*note Target Descriptions::) as an XML file. By default print the target description for the current target, but if the optional argument FILE is provided, then that file is read in by GDB and then used to produce the description. The FILE should be an XML document, of the form described in *Note Target Description Format::. `maint check xml-descriptions DIR' Check that the target descriptions dynamically created by GDB equal the descriptions created from XML files found in DIR. `maint check libthread-db' Run integrity checks on the current inferior's thread debugging library. This exercises all `libthread_db' functionality used by GDB on GNU/Linux systems, and by extension also exercises the `proc_service' functions provided by GDB that `libthread_db' uses. Note that parts of the test may be skipped on some platforms when debugging core files. `maint print core-file-backed-mappings' Print the file-backed mappings which were loaded from a core file note. This output represents state internal to GDB and should be similar to the mappings displayed by the `info proc mappings' command. `maint print dummy-frames' Prints the contents of GDB's internal dummy-frame stack. (gdb) b add ... (gdb) print add(2,3) Breakpoint 2, add (a=2, b=3) at ... 58 return (a + b); The program being debugged stopped while in a function called from GDB. ... (gdb) maint print dummy-frames 0xa8206d8: id={stack=0xbfffe734,code=0xbfffe73f,!special}, ptid=process 9353 (gdb) Takes an optional file parameter. `maint print frame-id' `maint print frame-id LEVEL' Print GDB's internal frame-id for the frame at relative LEVEL, or for the currently selected frame when LEVEL is not given. If used, LEVEL should be an integer, as displayed in the `backtrace' output. (gdb) maint print frame-id frame-id for frame #0: {stack=0x7fffffffac70,code=0x0000000000401106,!special} (gdb) maint print frame-id 2 frame-id for frame #2: {stack=0x7fffffffac90,code=0x000000000040111c,!special} `maint print registers [FILE]' `maint print raw-registers [FILE]' `maint print cooked-registers [FILE]' `maint print register-groups [FILE]' `maint print remote-registers [FILE]' Print GDB's internal register data structures. The command `maint print raw-registers' includes the contents of the raw register cache; the command `maint print cooked-registers' includes the (cooked) value of all registers, including registers which aren't available on the target nor visible to user; the command `maint print register-groups' includes the groups that each register is a member of; and the command `maint print remote-registers' includes the remote target's register numbers and offsets in the `G' packets. These commands take an optional parameter, a file name to which to write the information. `maint print reggroups [FILE]' Print GDB's internal register group data structures. The optional argument FILE tells to what file to write the information. The register groups info looks like this: (gdb) maint print reggroups Group Type general user float user all user vector user system user save internal restore internal `maint flush register-cache' `flushregs' Flush the contents of the register cache and as a consequence the frame cache. This command is useful when debugging issues related to register fetching, or frame unwinding. The command `flushregs' is deprecated in favor of `maint flush register-cache'. `maint flush source-cache' Flush GDB's cache of source code file contents. After GDB reads a source file, and optionally applies styling (*note Output Styling::), the file contents are cached. This command clears that cache. The next time GDB wants to show lines from a source file, the content will be re-read. This command is useful when debugging issues related to source code styling. After flushing the cache any source code displayed by GDB will be re-read and re-styled. `maint print objfiles [REGEXP]' Print a dump of all known object files. If REGEXP is specified, only print object files whose names match REGEXP. For each object file, this command prints its name, address in memory, and all of its psymtabs and symtabs. `maint print user-registers' List all currently available "user registers". User registers typically provide alternate names for actual hardware registers. They include the four "standard" registers `$fp', `$pc', `$sp', and `$ps'. *Note standard registers::. User registers can be used in expressions in the same way as the canonical register names, but only the latter are listed by the `info registers' and `maint print registers' commands. `maint print section-scripts [REGEXP]' Print a dump of scripts specified in the `.debug_gdb_section' section. If REGEXP is specified, only print scripts loaded by object files matching REGEXP. For each script, this command prints its name as specified in the objfile, and the full path if known. *Note dotdebug_gdb_scripts section::. `maint print statistics' This command prints, for each object file in the program, various data about that object file followed by the byte cache ("bcache") statistics for the object file. The objfile data includes the number of minimal, partial, full, and stabs symbols, the number of types defined by the objfile, the number of as yet unexpanded psym tables, the number of line tables and string tables, and the amount of memory used by the various tables. The bcache statistics include the counts, sizes, and counts of duplicates of all and unique objects, max, average, and median entry size, total memory used and its overhead and savings, and various measures of the hash table size and chain lengths. `maint print target-stack' A "target" is an interface between the debugger and a particular kind of file or process. Targets can be stacked in "strata", so that more than one target can potentially respond to a request. In particular, memory accesses will walk down the stack of targets until they find a target that is interested in handling that particular address. This command prints a short description of each layer that was pushed on the "target stack", starting from the top layer down to the bottom one. `maint print type EXPR' Print the type chain for a type specified by EXPR. The argument can be either a type name or a symbol. If it is a symbol, the type of that symbol is described. The type chain produced by this command is a recursive definition of the data type as stored in GDB's data structures, including its flags and contained types. `maint print record-instruction' `maint print record-instruction N' print how GDB recorded a given instruction. If N is not positive number, it prints the values stored by the inferior before the N-th previous instruction was executed. If N is positive, print the values after the N-th following instruction is executed. If N is not given, 0 is assumed. `maint selftest [-verbose] [FILTER]' Run any self tests that were compiled in to GDB. This will print a message showing how many tests were run, and how many failed. If a FILTER is passed, only the tests with FILTER in their name will be ran. If `-verbose' is passed, the self tests can be more verbose. `maint set selftest verbose' `maint show selftest verbose' Control whether self tests are run verbosely or not. `maint info selftests' List the selftests compiled in to GDB. `maint set dwarf always-disassemble' `maint show dwarf always-disassemble' Control the behavior of `info address' when using DWARF debugging information. The default is `off', which means that GDB should try to describe a variable's location in an easily readable format. When `on', GDB will instead display the DWARF location expression in an assembly-like format. Note that some locations are too complex for GDB to describe simply; in this case you will always see the disassembly form. Here is an example of the resulting disassembly: (gdb) info addr argc Symbol "argc" is a complex DWARF expression: 1: DW_OP_fbreg 0 For more information on these expressions, see the DWARF standard (http://www.dwarfstd.org/). `maint set dwarf max-cache-age' `maint show dwarf max-cache-age' Control the DWARF compilation unit cache. In object files with inter-compilation-unit references, such as those produced by the GCC option `-feliminate-dwarf2-dups', the DWARF reader needs to frequently refer to previously read compilation units. This setting controls how long a compilation unit will remain in the cache if it is not referenced. A higher limit means that cached compilation units will be stored in memory longer, and more total memory will be used. Setting it to zero disables caching, which will slow down GDB startup, but reduce memory consumption. `maint set dwarf synchronous' `maint show dwarf synchronous' Control whether DWARF is read asynchronously. On hosts where threading is available, the DWARF reader is mostly asynchronous with respect to the rest of GDB. That is, the bulk of the reading is done in the background, and GDB will only pause for completion of this task when absolutely necessary. When this setting is enabled, GDB will instead wait for DWARF processing to complete before continuing. On hosts without threading, or where worker threads have been disabled at runtime, this setting has no effect, as DWARF reading is always done on the main thread, and is therefore always synchronous. `maint set dwarf unwinders' `maint show dwarf unwinders' Control use of the DWARF frame unwinders. Many targets that support DWARF debugging use GDB's DWARF frame unwinders to build the backtrace. Many of these targets will also have a second mechanism for building the backtrace for use in cases where DWARF information is not available, this second mechanism is often an analysis of a function's prologue. In order to extend testing coverage of the second level stack unwinding mechanisms it is helpful to be able to disable the DWARF stack unwinders, this can be done with this switch. In normal use of GDB disabling the DWARF unwinders is not advisable, there are cases that are better handled through DWARF than prologue analysis, and the debug experience is likely to be better with the DWARF frame unwinders enabled. If DWARF frame unwinders are not supported for a particular target architecture, then enabling this flag does not cause them to be used. `maint info frame-unwinders' List the frame unwinders currently in effect, starting with the highest priority. `maint set worker-threads' `maint show worker-threads' Control the number of worker threads that may be used by GDB. On capable hosts, GDB may use multiple threads to speed up certain CPU-intensive operations, such as demangling symbol names. While the number of threads used by GDB may vary, this command can be used to set an upper bound on this number. The default is `unlimited', which lets GDB choose a reasonable number. Note that this only controls worker threads started by GDB itself; libraries used by GDB may start threads of their own. `maint set profile' `maint show profile' Control profiling of GDB. Profiling will be disabled until you use the `maint set profile' command to enable it. When you enable profiling, the system will begin collecting timing and execution count data; when you disable profiling or exit GDB, the results will be written to a log file. Remember that if you use profiling, GDB will overwrite the profiling log file (often called `gmon.out'). If you have a record of important profiling data in a `gmon.out' file, be sure to move it to a safe location. Configuring with `--enable-profiling' arranges for GDB to be compiled with the `-pg' compiler option. `maint set show-debug-regs' `maint show show-debug-regs' Control whether to show variables that mirror the hardware debug registers. Use `on' to enable, `off' to disable. If enabled, the debug registers values are shown when GDB inserts or removes a hardware breakpoint or watchpoint, and when the inferior triggers a hardware-assisted breakpoint or watchpoint. `maint set show-all-tib' `maint show show-all-tib' Control whether to show all non zero areas within a 1k block starting at thread local base, when using the `info w32 thread-information-block' command. `maint set target-async' `maint show target-async' This controls whether GDB targets operate in synchronous or asynchronous mode (*note Background Execution::). Normally the default is asynchronous, if it is available; but this can be changed to more easily debug problems occurring only in synchronous mode. `maint set target-non-stop' `maint show target-non-stop' This controls whether GDB targets always operate in non-stop mode even if `set non-stop' is `off' (*note Non-Stop Mode::). The default is `auto', meaning non-stop mode is enabled if supported by the target. `maint set target-non-stop auto' This is the default mode. GDB controls the target in non-stop mode if the target supports it. `maint set target-non-stop on' GDB controls the target in non-stop mode even if the target does not indicate support. `maint set target-non-stop off' GDB does not control the target in non-stop mode even if the target supports it. `maint set tui-resize-message' `maint show tui-resize-message' Control whether GDB displays a message each time the terminal is resized when in TUI mode. The default is `off', which means that GDB is silent during resizes. When `on', GDB will display a message after a resize is completed; the message will include a number indicating how many times the terminal has been resized. This setting is intended for use by the test suite, where it would otherwise be difficult to determine when a resize and refresh has been completed. `maint set tui-left-margin-verbose' `maint show tui-left-margin-verbose' Control whether the left margin of the TUI source and disassembly windows uses `_' and `0' at locations where otherwise there would be a space. The default is `off', which means spaces are used. The setting is intended to make it clear where the left margin begins and ends, to avoid incorrectly interpreting a space as being part of the the left margin. `maint set per-command' `maint show per-command' GDB can display the resources used by each command. This is useful in debugging performance problems. `maint set per-command space [on|off]' `maint show per-command space' Enable or disable the printing of the memory used by GDB for each command. If enabled, GDB will display how much memory each command took, following the command's own output. This can also be requested by invoking GDB with the `--statistics' command-line switch (*note Mode Options::). `maint set per-command time [on|off]' `maint show per-command time' Enable or disable the printing of the execution time of GDB for each command. If enabled, GDB will display how much time it took to execute each command, following the command's own output. Both CPU time and wallclock time are printed. Printing both is useful when trying to determine whether the cost is CPU or, e.g., disk/network latency. Note that the CPU time printed is for GDB only, it does not include the execution time of the inferior because there's no mechanism currently to compute how much time was spent by GDB and how much time was spent by the program been debugged. This can also be requested by invoking GDB with the `--statistics' command-line switch (*note Mode Options::). `maint set per-command symtab [on|off]' `maint show per-command symtab' Enable or disable the printing of basic symbol table statistics for each command. If enabled, GDB will display the following information: a. number of symbol tables b. number of primary symbol tables c. number of blocks in the blockvector `maint set check-libthread-db [on|off]' `maint show check-libthread-db' Control whether GDB should run integrity checks on inferior specific thread debugging libraries as they are loaded. The default is not to perform such checks. If any check fails GDB will unload the library and continue searching for a suitable candidate as described in *Note set libthread-db-search-path::. For more information about the tests, see *Note maint check libthread-db::. `maint set gnu-source-highlight enabled [on|off]' `maint show gnu-source-highlight enabled' Control whether GDB should use the GNU Source Highlight library for applying styling to source code (*note Output Styling::). This will be `on' by default if the GNU Source Highlight library is available. If the GNU Source Highlight library is not available, then this will be `off' by default, and attempting to change this value to `on' will give an error. If the GNU Source Highlight library is not being used, then GDB will use the Python Pygments package for source code styling, if it is available. This option is useful for debugging GDB's use of the Pygments library when GDB is linked against the GNU Source Highlight library. `maint set libopcodes-styling enabled [on|off]' `maint show libopcodes-styling enabled' Control whether GDB should use its builtin disassembler (`libopcodes') to style disassembler output (*note Output Styling::). The builtin disassembler does not support styling for all architectures. When this option is `off' the builtin disassembler will not be used for styling, GDB will fall back to using the Python Pygments package if possible. Trying to set this option `on' for an architecture that the builtin disassembler is unable to style will give an error, otherwise, the builtin disassembler will be used to style disassembler output. This option is `on' by default for supported architectures. This option is useful for debugging GDB's use of the Pygments library when GDB is built for an architecture that supports styling with the builtin disassembler `maint info screen' Print various characteristics of the screen, such as various notions of width and height. `maint space VALUE' An alias for `maint set per-command space'. A non-zero value enables it, zero disables it. `maint time VALUE' An alias for `maint set per-command time'. A non-zero value enables it, zero disables it. `maint translate-address [SECTION] ADDR' Find the symbol stored at the location specified by the address ADDR and an optional section name SECTION. If found, GDB prints the name of the closest symbol and an offset from the symbol's location to the specified address. This is similar to the `info address' command (*note Symbols::), except that this command also allows to find symbols in other sections. If section was not specified, the section in which the symbol was found is also printed. For dynamically linked executables, the name of executable or shared library containing the symbol is printed as well. `maint test-options require-delimiter' `maint test-options unknown-is-error' `maint test-options unknown-is-operand' These commands are used by the testsuite to validate the command options framework. The `require-delimiter' variant requires a double-dash delimiter to indicate end of options. The `unknown-is-error' and `unknown-is-operand' do not. The `unknown-is-error' variant throws an error on unknown option, while `unknown-is-operand' treats unknown options as the start of the command's operands. When run, the commands output the result of the processed options. When completed, the commands store the internal result of completion in a variable exposed by the `maint show test-options-completion-result' command. `maint show test-options-completion-result' Shows the result of completing the `maint test-options' subcommands. This is used by the testsuite to validate completion support in the command options framework. `maint set test-settings KIND' `maint show test-settings KIND' These are representative commands for each KIND of setting type GDB supports. They are used by the testsuite for exercising the settings infrastructure. `maint set backtrace-on-fatal-signal [on|off]' `maint show backtrace-on-fatal-signal' When this setting is `on', if GDB itself terminates with a fatal signal (e.g. SIGSEGV), then a limited backtrace will be printed to the standard error stream. This backtrace can be used to help diagnose crashes within GDB in situations where a user is unable to share a corefile with the GDB developers. If the functionality to provide this backtrace is not available for the platform on which GDB is running then this feature will be `off' by default, and attempting to turn this feature on will give an error. For platforms that do support creating the backtrace this feature is `on' by default. `maint wait-for-index-cache' Wait until all pending writes to the index cache have completed. This is used by the test suite to avoid races when the index cache is being updated by a worker thread. `maint with SETTING [VALUE] [-- COMMAND]' Like the `with' command, but works with `maintenance set' variables. This is used by the testsuite to exercise the `with' command's infrastructure. `maint ignore-probes [-V|-VERBOSE] [PROVIDER [NAME [OBJFILE]]]' `maint ignore-probes -RESET' Set or reset the ignore-probes filter. The PROVIDER, NAME and OBJFILE arguments are as in `enable probes' and `disable probes' (*note enable probes::). Only supported for SystemTap probes. Here's an example of using `maint ignore-probes': (gdb) maint ignore-probes -verbose libc ^longjmp$ ignore-probes filter has been set to: PROVIDER: 'libc' PROBE_NAME: '^longjmp$' OBJNAME: '' (gdb) start <... more output ...> Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M Ignoring SystemTap probe libc longjmp in /lib64/libc.so.6.^M The following command is useful for non-interactive invocations of GDB, such as in the test suite. `set watchdog NSEC' Set the maximum number of seconds GDB will wait for the target operation to finish. If this time expires, GDB reports and error and the command is aborted. `show watchdog' Show the current setting of the target wait timeout.  File: gdb.info, Node: Remote Protocol, Next: Agent Expressions, Prev: Maintenance Commands, Up: Top Appendix E GDB Remote Serial Protocol ************************************* * Menu: * Overview:: * Standard Replies:: * Packets:: * Stop Reply Packets:: * General Query Packets:: * Architecture-Specific Protocol Details:: * Tracepoint Packets:: * Host I/O Packets:: * Interrupts:: * Notification Packets:: * Remote Non-Stop:: * Packet Acknowledgment:: * Examples:: * File-I/O Remote Protocol Extension:: * Library List Format:: * Library List Format for SVR4 Targets:: * Memory Map Format:: * Thread List Format:: * Traceframe Info Format:: * Branch Trace Format:: * Branch Trace Configuration Format::  File: gdb.info, Node: Overview, Next: Standard Replies, Up: Remote Protocol E.1 Overview ============ There may be occasions when you need to know something about the protocol--for example, if there is only one serial port to your target machine, you might want your program to do something special if it recognizes a packet meant for GDB. In the examples below, `->' and `<-' are used to indicate transmitted and received data, respectively. All GDB commands and responses (other than acknowledgments and notifications, see *Note Notification Packets::) are sent as a PACKET. A PACKET is introduced with the character `$', the actual PACKET-DATA, and the terminating character `#' followed by a two-digit CHECKSUM: `$'PACKET-DATA`#'CHECKSUM The two-digit CHECKSUM is computed as the modulo 256 sum of all characters between the leading `$' and the trailing `#' (an eight bit unsigned checksum). Implementors should note that prior to GDB 5.0 the protocol specification also included an optional two-digit SEQUENCE-ID: `$'SEQUENCE-ID`:'PACKET-DATA`#'CHECKSUM That SEQUENCE-ID was appended to the acknowledgment. GDB has never output SEQUENCE-IDs. Stubs that handle packets added since GDB 5.0 must not accept SEQUENCE-ID. When either the host or the target machine receives a packet, the first response expected is an acknowledgment: either `+' (to indicate the package was received correctly) or `-' (to request retransmission): -> `$'PACKET-DATA`#'CHECKSUM <- `+' The `+'/`-' acknowledgments can be disabled once a connection is established. *Note Packet Acknowledgment::, for details. The host (GDB) sends COMMANDs, and the target (the debugging stub incorporated in your program) sends a RESPONSE. In the case of step and continue COMMANDs, the response is only sent when the operation has completed, and the target has again stopped all threads in all attached processes. This is the default all-stop mode behavior, but the remote protocol also supports GDB's non-stop execution mode; see *Note Remote Non-Stop::, for details. PACKET-DATA consists of a sequence of characters with the exception of `#' and `$' (see `X' packet for additional exceptions). Fields within the packet should be separated using `,' `;' or `:'. Except where otherwise noted all numbers are represented in HEX with leading zeros suppressed. Implementors should note that prior to GDB 5.0, the character `:' could not appear as the third character in a packet (as it would potentially conflict with the SEQUENCE-ID). Binary data in most packets is encoded as two hexadecimal digits per byte of binary data. This allowed the traditional remote protocol to work over connections which were only seven-bit clean. Some packets designed more recently assume an eight-bit clean connection, and use a more efficient encoding to send and receive binary data. The binary data representation uses `7d' (ASCII `}') as an escape character. Any escaped byte is transmitted as the escape character followed by the original character XORed with `0x20'. For example, the byte `0x7d' would be transmitted as the two bytes `0x7d 0x5d'. The bytes `0x23' (ASCII `#'), `0x24' (ASCII `$'), and `0x7d' (ASCII `}') must always be escaped. Responses sent by the stub must also escape `0x2a' (ASCII `*'), so that it is not interpreted as the start of a run-length encoded sequence (described next). Response DATA can be run-length encoded to save space. Run-length encoding replaces runs of identical characters with one instance of the repeated character, followed by a `*' and a repeat count. The repeat count is itself sent encoded, to avoid binary characters in DATA: a value of N is sent as `N+29'. For a repeat count greater or equal to 3, this produces a printable ASCII character, e.g. a space (ASCII code 32) for a repeat count of 3. (This is because run-length encoding starts to win for counts 3 or more.) Thus, for example, `0* ' is a run-length encoding of "0000": the space character after `*' means repeat the leading `0' `32 - 29 = 3' more times. The printable characters `#' and `$' or with a numeric value greater than 126 must not be used. Runs of six repeats (`#') or seven repeats (`$') can be expanded using a repeat count of only five (`"'). For example, `00000000' can be encoded as `0*"00'. *Note Standard Replies:: for standard error responses, and how to respond indicating a command is not supported. In describing packets (commands and responses), each description has a template showing the overall syntax, followed by an explanation of the packet's meaning. We include spaces in some of the templates for clarity; these are not part of the packet's syntax. No GDB packet uses spaces to separate its components. For example, a template like `foo BAR BAZ' describes a packet beginning with the three ASCII bytes `foo', followed by a BAR, followed directly by a BAZ. GDB does not transmit a space character between the `foo' and the BAR, or between the BAR and the BAZ. We place optional portions of a packet in [square brackets]; for example, a template like `c [ADDR]' describes a packet beginning with the single ASCII character `c', possibly followed by an ADDR. At a minimum, a stub is required to support the `?' command to tell GDB the reason for halting, `g' and `G' commands for register access, and the `m' and `M' commands for memory access. Stubs that only control single-threaded targets can implement run control with the `c' (continue) command, and if the target architecture supports hardware-assisted single-stepping, the `s' (step) command. Stubs that support multi-threading targets should support the `vCont' command. All other commands are optional.  File: gdb.info, Node: Standard Replies, Next: Packets, Prev: Overview, Up: Remote Protocol E.2 Standard Replies ==================== The remote protocol specifies a few standard replies. All commands support these, except as noted in the individual command descriptions. empty response An empty response (raw character sequence `$#00') means the COMMAND is not supported by the stub. This way it is possible to extend the protocol. A newer GDB can tell if a command is supported based on that response (but see also *Note qSupported::). `E XX' An error has occurred; XX is a two-digit hexadecimal error number. In almost all cases, the protocol does not specify the meaning of the error numbers; GDB usually ignores the numbers, or displays them to the user without further interpretation. `E.ERRTEXT' An error has occurred; ERRTEXT is the textual error message, encoded in ASCII.  File: gdb.info, Node: Packets, Next: Stop Reply Packets, Prev: Standard Replies, Up: Remote Protocol E.3 Packets =========== The following table provides a complete list of all currently defined COMMANDs and their corresponding response DATA. *Note File-I/O Remote Protocol Extension::, for details about the File I/O extension of the remote protocol. Each packet's description has a template showing the packet's overall syntax, followed by an explanation of the packet's meaning. We include spaces in some of the templates for clarity; these are not part of the packet's syntax. No GDB packet uses spaces to separate its components. For example, a template like `foo BAR BAZ' describes a packet beginning with the three ASCII bytes `foo', followed by a BAR, followed directly by a BAZ. GDB does not transmit a space character between the `foo' and the BAR, or between the BAR and the BAZ. Several packets and replies include a THREAD-ID field to identify a thread. Normally these are positive numbers with a target-specific interpretation, formatted as big-endian hex strings. A THREAD-ID can also be a literal `-1' to indicate all threads, or `0' to pick any thread. In addition, the remote protocol supports a multiprocess feature in which the THREAD-ID syntax is extended to optionally include both process and thread ID fields, as `pPID.TID'. The PID (process) and TID (thread) components each have the format described above: a positive number with target-specific interpretation formatted as a big-endian hex string, literal `-1' to indicate all processes or threads (respectively), or `0' to indicate an arbitrary process or thread. Specifying just a process, as `pPID', is equivalent to `pPID.-1'. It is an error to specify all processes but a specific thread, such as `p-1.TID'. Note that the `p' prefix is _not_ used for those packets and replies explicitly documented to include a process ID, rather than a THREAD-ID. The multiprocess THREAD-ID syntax extensions are only used if both GDB and the stub report support for the `multiprocess' feature using `qSupported'. *Note multiprocess extensions::, for more information. Note that all packet forms beginning with an upper- or lower-case letter, other than those described here, are reserved for future use. Here are the packet descriptions. `!' Enable extended mode. In extended mode, the remote server is made persistent. The `R' packet is used to restart the program being debugged. Reply: `OK' The remote target both supports and has enabled extended mode. `?' This is sent when connection is first established to query the reason the target halted. The reply is the same as for step and continue. This packet has a special interpretation when the target is in non-stop mode; see *Note Remote Non-Stop::. Reply: *Note Stop Reply Packets::, for the reply specifications. `A ARGLEN,ARGNUM,ARG,...' Initialized `argv[]' array passed into program. ARGLEN specifies the number of bytes in the hex encoded byte stream ARG. See `gdbserver' for more details. Reply: `OK' The arguments were set. `b BAUD' (Don't use this packet; its behavior is not well-defined.) Change the serial line speed to BAUD. JTC: _When does the transport layer state change? When it's received, or after the ACK is transmitted. In either case, there are problems if the command or the acknowledgment packet is dropped._ Stan: _If people really wanted to add something like this, and get it working for the first time, they ought to modify ser-unix.c to send some kind of out-of-band message to a specially-setup stub and have the switch happen "in between" packets, so that from remote protocol's point of view, nothing actually happened._ `B ADDR,MODE' Set (MODE is `S') or clear (MODE is `C') a breakpoint at ADDR. Don't use this packet. Use the `Z' and `z' packets instead (*note insert breakpoint or watchpoint packet::). `bc' Backward continue. Execute the target system in reverse. No parameter. *Note Reverse Execution::, for more information. Reply: *Note Stop Reply Packets::, for the reply specifications. `bs' Backward single step. Execute one instruction in reverse. No parameter. *Note Reverse Execution::, for more information. Reply: *Note Stop Reply Packets::, for the reply specifications. `c [ADDR]' Continue at ADDR, which is the address to resume. If ADDR is omitted, resume at current address. This packet is deprecated for multi-threading support. *Note vCont packet::. Reply: *Note Stop Reply Packets::, for the reply specifications. `C SIG[;ADDR]' Continue with signal SIG (hex signal number). If `;ADDR' is omitted, resume at same address. This packet is deprecated for multi-threading support. *Note vCont packet::. Reply: *Note Stop Reply Packets::, for the reply specifications. `d' Toggle debug flag. Don't use this packet; instead, define a general set packet (*note General Query Packets::). `D' `D;PID' The first form of the packet is used to detach GDB from the remote system. It is sent to the remote target before GDB disconnects via the `detach' command. The second form, including a process ID, is used when multiprocess protocol extensions are enabled (*note multiprocess extensions::), to detach only a specific process. The PID is specified as a big-endian hex string. Reply: `OK' for success `F RC,EE,CF;XX' A reply from GDB to an `F' packet sent by the target. This is part of the File-I/O protocol extension. *Note File-I/O Remote Protocol Extension::, for the specification. `g' Read general registers. Reply: `XX...' Each byte of register data is described by two hex digits. The bytes with the register are transmitted in target byte order. The size of each register and their position within the `g' packet are determined by the target description (*note Target Descriptions::); in the absence of a target description, this is done using code internal to GDB; typically this is some customary register layout for the architecture in question. When reading registers, the stub may also return a string of literal `x''s in place of the register data digits, to indicate that the corresponding register's value is unavailable. For example, when reading registers from a trace frame (*note Using the Collected Data: Analyze Collected Data.), this means that the register has not been collected in the trace frame. When reading registers from a live program, this indicates that the stub has no means to access the register contents, even though the corresponding register is known to exist. Note that if a register truly does not exist on the target, then it is better to not include it in the target description in the first place. For example, for an architecture with 4 registers of 4 bytes each, the following reply indicates to GDB that registers 0 and 2 are unavailable, while registers 1 and 3 are available, and both have zero value: -> `g' <- `xxxxxxxx00000000xxxxxxxx00000000' `G XX...' Write general registers. *Note read registers packet::, for a description of the XX... data. Reply: `OK' for success `H OP THREAD-ID' Set thread for subsequent operations (`m', `M', `g', `G', et.al.). Depending on the operation to be performed, OP should be `c' for step and continue operations (note that this is deprecated, supporting the `vCont' command is a better option), and `g' for other operations. The thread designator THREAD-ID has the format and interpretation described in *Note thread-id syntax::. Reply: `OK' for success `i [ADDR[,NNN]]' Step the remote target by a single clock cycle. If `,NNN' is present, cycle step NNN cycles. If ADDR is present, cycle step starting at that address. `I' Signal, then cycle step. *Note step with signal packet::. *Note cycle step packet::. `k' Kill request. The exact effect of this packet is not specified. For a bare-metal target, it may power cycle or reset the target system. For that reason, the `k' packet has no reply. For a single-process target, it may kill that process if possible. A multiple-process target may choose to kill just one process, or all that are under GDB's control. For more precise control, use the vKill packet (*note vKill packet::). If the target system immediately closes the connection in response to `k', GDB does not consider the lack of packet acknowledgment to be an error, and assumes the kill was successful. If connected using `target extended-remote', and the target does not close the connection in response to a kill request, GDB probes the target state as if a new connection was opened (*note ? packet::). `m ADDR,LENGTH' Read LENGTH addressable memory units starting at address ADDR (*note addressable memory unit::). Note that ADDR may not be aligned to any particular boundary. The stub need not use any particular size or alignment when gathering data from memory for the response; even if ADDR is word-aligned and LENGTH is a multiple of the word size, the stub is free to use byte accesses, or not. For this reason, this packet may not be suitable for accessing memory-mapped I/O devices. Reply: `XX...' Memory contents; each byte is transmitted as a two-digit hexadecimal number. The reply may contain fewer addressable memory units than requested if the server was able to read only part of the region of memory. Unlike most packets, this packet does not support `E.ERRTEXT'-style textual error replies (*note textual error reply::). `M ADDR,LENGTH:XX...' Write LENGTH addressable memory units starting at address ADDR (*note addressable memory unit::). The data is given by XX...; each byte is transmitted as a two-digit hexadecimal number. Reply: `OK' All the data was written successfully. (If only part of the data was written, this command returns an error.) `p N' Read the value of register N; N is in hex. *Note read registers packet::, for a description of how the returned register value is encoded. Reply: `XX...' the register's value `P N...=R...' Write register N... with value R.... The register number N is in hexadecimal, and R... contains two hex digits for each byte in the register (target byte order). Reply: `OK' for success `q NAME PARAMS...' `Q NAME PARAMS...' General query (`q') and set (`Q'). These packets are described fully in *Note General Query Packets::. `r' Reset the entire system. Don't use this packet; use the `R' packet instead. `R XX' Restart the program being debugged. The XX, while needed, is ignored. This packet is only available in extended mode (*note extended mode::). The `R' packet has no reply. `s [ADDR]' Single step, resuming at ADDR. If ADDR is omitted, resume at same address. This packet is deprecated for multi-threading support. *Note vCont packet::. Reply: *Note Stop Reply Packets::, for the reply specifications. `S SIG[;ADDR]' Step with signal. This is analogous to the `C' packet, but requests a single-step, rather than a normal resumption of execution. This packet is deprecated for multi-threading support. *Note vCont packet::. Reply: *Note Stop Reply Packets::, for the reply specifications. `t ADDR:PP,MM' Search backwards starting at address ADDR for a match with pattern PP and mask MM, both of which are are 4 byte long. There must be at least 3 digits in ADDR. `T THREAD-ID' Find out if the thread THREAD-ID is alive. *Note thread-id syntax::. Reply: `OK' thread is still alive `v' Packets starting with `v' are identified by a multi-letter name, up to the first `;' or `?' (or the end of the packet). `vAttach;PID' Attach to a new process with the specified process ID PID. The process ID is a hexadecimal integer identifying the process. In all-stop mode, all threads in the attached process are stopped; in non-stop mode, it may be attached without being stopped if that is supported by the target. This packet is only available in extended mode (*note extended mode::). Reply: `Any stop packet' for success in all-stop mode (*note Stop Reply Packets::) `OK' for success in non-stop mode (*note Remote Non-Stop::) `vCont[;ACTION[:THREAD-ID]]...' Resume the inferior, specifying different actions for each thread. For each inferior thread, the leftmost action with a matching THREAD-ID is applied. Threads that don't match any action remain in their current state. Thread IDs are specified using the syntax described in *Note thread-id syntax::. If multiprocess extensions (*note multiprocess extensions::) are supported, actions can be specified to match all threads in a process by using the `pPID.-1' form of the THREAD-ID. An action with no THREAD-ID matches all threads. Specifying no actions is an error. Currently supported actions are: `c' Continue. `C SIG' Continue with signal SIG. The signal SIG should be two hex digits. `s' Step. `S SIG' Step with signal SIG. The signal SIG should be two hex digits. `t' Stop. `r START,END' Step once, and then keep stepping as long as the thread stops at addresses between START (inclusive) and END (exclusive). The remote stub reports a stop reply when either the thread goes out of the range or is stopped due to an unrelated reason, such as hitting a breakpoint. *Note range stepping::. If the range is empty (START == END), then the action becomes equivalent to the `s' action. In other words, single-step once, and report the stop (even if the stepped instruction jumps to START). (A stop reply may be sent at any point even if the PC is still within the stepping range; for example, it is valid to implement this packet in a degenerate way as a single instruction step operation.) The optional argument ADDR normally associated with the `c', `C', `s', and `S' packets is not supported in `vCont'. The `t' action is only relevant in non-stop mode (*note Remote Non-Stop::) and may be ignored by the stub otherwise. A stop reply should be generated for any affected thread not already stopped. When a thread is stopped by means of a `t' action, the corresponding stop reply should indicate that the thread has stopped with signal `0', regardless of whether the target uses some other signal as an implementation detail. The server must ignore `c', `C', `s', `S', and `r' actions for threads that are already running. Conversely, the server must ignore `t' actions for threads that are already stopped. _Note:_ In non-stop mode, a thread is considered running until GDB acknowledges an asynchronous stop notification for it with the `vStopped' packet (*note Remote Non-Stop::). The stub must support `vCont' if it reports support for multiprocess extensions (*note multiprocess extensions::). Reply: *Note Stop Reply Packets::, for the reply specifications. `vCont?' Request a list of actions supported by the `vCont' packet. Reply: `vCont[;ACTION...]' The `vCont' packet is supported. Each ACTION is a supported command in the `vCont' packet. `vCtrlC' Interrupt remote target as if a control-C was pressed on the remote terminal. This is the equivalent to reacting to the `^C' (`\003', the control-C character) character in all-stop mode while the target is running, except this works in non-stop mode. *Note interrupting remote targets::, for more info on the all-stop variant. Reply: `OK' for success `vFile:OPERATION:PARAMETER...' Perform a file operation on the target system. For details, see *Note Host I/O Packets::. `vFlashErase:ADDR,LENGTH' Direct the stub to erase LENGTH bytes of flash starting at ADDR. The region may enclose any number of flash blocks, but its start and end must fall on block boundaries, as indicated by the flash block size appearing in the memory map (*note Memory Map Format::). GDB groups flash memory programming operations together, and sends a `vFlashDone' request after each group; the stub is allowed to delay erase operation until the `vFlashDone' packet is received. Reply: `OK' for success `vFlashWrite:ADDR:XX...' Direct the stub to write data to flash address ADDR. The data is passed in binary form using the same encoding as for the `X' packet (*note Binary Data::). The memory ranges specified by `vFlashWrite' packets preceding a `vFlashDone' packet must not overlap, and must appear in order of increasing addresses (although `vFlashErase' packets for higher addresses may already have been received; the ordering is guaranteed only between `vFlashWrite' packets). If a packet writes to an address that was neither erased by a preceding `vFlashErase' packet nor by some other target-specific method, the results are unpredictable. Reply: `OK' for success `E.memtype' for vFlashWrite addressing non-flash memory `vFlashDone' Indicate to the stub that flash programming operation is finished. The stub is permitted to delay or batch the effects of a group of `vFlashErase' and `vFlashWrite' packets until a `vFlashDone' packet is received. The contents of the affected regions of flash memory are unpredictable until the `vFlashDone' request is completed. `vKill;PID' Kill the process with the specified process ID PID, which is a hexadecimal integer identifying the process. This packet is used in preference to `k' when multiprocess protocol extensions are supported; see *Note multiprocess extensions::. Reply: `OK' for success `vMustReplyEmpty' The correct reply to an unknown `v' packet is to return the empty string, however, some older versions of `gdbserver' would incorrectly return `OK' for unknown `v' packets. The `vMustReplyEmpty' is used as a feature test to check how `gdbserver' handles unknown packets, it is important that this packet be handled in the same way as other unknown `v' packets. If this packet is handled differently to other unknown `v' packets then it is possible that GDB may run into problems in other areas, specifically around use of `vFile:setfs:'. `vRun;FILENAME[;ARGUMENT]...' Run the program FILENAME, passing it each ARGUMENT on its command line. The file and arguments are hex-encoded strings. If FILENAME is an empty string, the stub may use a default program (e.g. the last program run). The program is created in the stopped state. This packet is only available in extended mode (*note extended mode::). Reply: `Any stop packet' for success (*note Stop Reply Packets::) `vStopped' *Note Notification Packets::. `X ADDR,LENGTH:XX...' Write data to memory, where the data is transmitted in binary. Memory is specified by its address ADDR and number of addressable memory units LENGTH (*note addressable memory unit::); `XX...' is binary data (*note Binary Data::). Reply: `OK' for success `z TYPE,ADDR,KIND' `Z TYPE,ADDR,KIND' Insert (`Z') or remove (`z') a TYPE breakpoint or watchpoint starting at address ADDRESS of kind KIND. Each breakpoint and watchpoint packet TYPE is documented separately. _Implementation notes: A remote target shall return an empty string for an unrecognized breakpoint or watchpoint packet TYPE. A remote target shall support either both or neither of a given `ZTYPE...' and `zTYPE...' packet pair. To avoid potential problems with duplicate packets, the operations should be implemented in an idempotent way._ `z0,ADDR,KIND' `Z0,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]' Insert (`Z0') or remove (`z0') a software breakpoint at address ADDR of type KIND. A software breakpoint is implemented by replacing the instruction at ADDR with a software breakpoint or trap instruction. The KIND is target-specific and typically indicates the size of the breakpoint in bytes that should be inserted. E.g., the ARM and MIPS can insert either a 2 or 4 byte breakpoint. Some architectures have additional meanings for KIND (*note Architecture-Specific Protocol Details::); if no architecture-specific value is being used, it should be `0'. KIND is hex-encoded. COND_LIST is an optional list of conditional expressions in bytecode form that should be evaluated on the target's side. These are the conditions that should be taken into consideration when deciding if the breakpoint trigger should be reported back to GDB. See also the `swbreak' stop reason (*note swbreak stop reason::) for how to best report a software breakpoint event to GDB. The COND_LIST parameter is comprised of a series of expressions, concatenated without separators. Each expression has the following form: `X LEN,EXPR' LEN is the length of the bytecode expression and EXPR is the actual conditional expression in bytecode form. The optional CMD_LIST parameter introduces commands that may be run on the target, rather than being reported back to GDB. The parameter starts with a numeric flag PERSIST; if the flag is nonzero, then the breakpoint may remain active and the commands continue to be run even when GDB disconnects from the target. Following this flag is a series of expressions concatenated with no separators. Each expression has the following form: `X LEN,EXPR' LEN is the length of the bytecode expression and EXPR is the actual commands expression in bytecode form. _Implementation note: It is possible for a target to copy or move code that contains software breakpoints (e.g., when implementing overlays). The behavior of this packet, in the presence of such a target, is not defined._ Reply: `OK' success `z1,ADDR,KIND' `Z1,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]' Insert (`Z1') or remove (`z1') a hardware breakpoint at address ADDR. A hardware breakpoint is implemented using a mechanism that is not dependent on being able to modify the target's memory. The KIND, COND_LIST, and CMD_LIST arguments have the same meaning as in `Z0' packets. _Implementation note: A hardware breakpoint is not affected by code movement._ Reply: `OK' success `z2,ADDR,KIND' `Z2,ADDR,KIND' Insert (`Z2') or remove (`z2') a write watchpoint at ADDR. The number of bytes to watch is specified by KIND. Reply: `OK' success `z3,ADDR,KIND' `Z3,ADDR,KIND' Insert (`Z3') or remove (`z3') a read watchpoint at ADDR. The number of bytes to watch is specified by KIND. Reply: `OK' success `z4,ADDR,KIND' `Z4,ADDR,KIND' Insert (`Z4') or remove (`z4') an access watchpoint at ADDR. The number of bytes to watch is specified by KIND. Reply: `OK' success  File: gdb.info, Node: Stop Reply Packets, Next: General Query Packets, Prev: Packets, Up: Remote Protocol E.4 Stop Reply Packets ====================== The `C', `c', `S', `s', `vCont', `vAttach', `vRun', `vStopped', and `?' packets can receive any of the below as a reply. Except for `?' and `vStopped', that reply is only returned when the target halts. In the below the exact meaning of "signal number" is defined by the header `include/gdb/signals.h' in the GDB source code. In non-stop mode, the server will simply reply `OK' to commands such as `vCont'; any stop will be the subject of a future notification. *Note Remote Non-Stop::. As in the description of request packets, we include spaces in the reply templates for clarity; these are not part of the reply packet's syntax. No GDB stop reply packet uses spaces to separate its components. `S AA' The program received signal number AA (a two-digit hexadecimal number). This is equivalent to a `T' response with no N:R pairs. `T AA N1:R1;N2:R2;...' The program received signal number AA (a two-digit hexadecimal number). This is equivalent to an `S' response, except that the `N:R' pairs can carry values of important registers and other information directly in the stop reply packet, reducing round-trip latency. Single-step and breakpoint traps are reported this way. Each `N:R' pair is interpreted as follows: * If N is a hexadecimal number, it is a register number, and the corresponding R gives that register's value. The data R is a series of bytes in target byte order, with each byte given by a two-digit hex number. * If N is `thread', then R is the thread ID of the stopped thread, as specified in *Note thread-id syntax::. * If N is `core', then R is the hexadecimal number of the core on which the stop event was detected. * If N is a recognized "stop reason", it describes a more specific event that stopped the target. The currently defined stop reasons are listed below. The AA should be `05', the trap signal. At most one stop reason should be present. * Otherwise, GDB should ignore this `N:R' pair and go on to the next; this allows us to extend the protocol in the future. The currently defined stop reasons are: `watch' `rwatch' `awatch' The packet indicates a watchpoint hit, and R is the data address, in hex. `syscall_entry' `syscall_return' The packet indicates a syscall entry or return, and R is the syscall number, in hex. `library' The packet indicates that the loaded libraries have changed. GDB should use `qXfer:libraries:read' to fetch a new list of loaded libraries. The R part is ignored. `replaylog' The packet indicates that the target cannot continue replaying logged execution events, because it has reached the end (or the beginning when executing backward) of the log. The value of R will be either `begin' or `end'. *Note Reverse Execution::, for more information. `swbreak' The packet indicates a software breakpoint instruction was executed, irrespective of whether it was GDB that planted the breakpoint or the breakpoint is hardcoded in the program. The R part must be left empty. On some architectures, such as x86, at the architecture level, when a breakpoint instruction executes the program counter points at the breakpoint address plus an offset. On such targets, the stub is responsible for adjusting the PC to point back at the breakpoint address. This packet should not be sent by default; older GDB versions did not support it. GDB requests it, by supplying an appropriate `qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate `qSupported' feature indicating support. This packet is required for correct non-stop mode operation. `hwbreak' The packet indicates the target stopped for a hardware breakpoint. The R part must be left empty. The same remarks about `qSupported' and non-stop mode above apply. `fork' The packet indicates that `fork' was called, and R is the thread ID of the new child process, as specified in *Note thread-id syntax::. This packet is only applicable to targets that support fork events. This packet should not be sent by default; older GDB versions did not support it. GDB requests it, by supplying an appropriate `qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate `qSupported' feature indicating support. `vfork' The packet indicates that `vfork' was called, and R is the thread ID of the new child process, as specified in *Note thread-id syntax::. This packet is only applicable to targets that support vfork events. This packet should not be sent by default; older GDB versions did not support it. GDB requests it, by supplying an appropriate `qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate `qSupported' feature indicating support. `vforkdone' The packet indicates that a child process created by a vfork has either called `exec' or terminated, so that the address spaces of the parent and child process are no longer shared. The R part is ignored. This packet is only applicable to targets that support vforkdone events. This packet should not be sent by default; older GDB versions did not support it. GDB requests it, by supplying an appropriate `qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate `qSupported' feature indicating support. `exec' The packet indicates that `execve' was called, and R is the absolute pathname of the file that was executed, in hex. This packet is only applicable to targets that support exec events. This packet should not be sent by default; older GDB versions did not support it. GDB requests it, by supplying an appropriate `qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate `qSupported' feature indicating support. `clone' The packet indicates that `clone' was called, and R is the thread ID of the new child thread, as specified in *Note thread-id syntax::. This packet is only applicable to targets that support clone events. This packet should not be sent by default; GDB requests it with the *Note QThreadOptions:: packet. `create' The packet indicates that the thread was just created. The new thread is stopped until GDB sets it running with a resumption packet (*note vCont packet::). This packet should not be sent by default; GDB requests it with the *Note QThreadEvents:: packet. See also the `w' (*note thread exit event::) remote reply below. The R part is ignored. `W AA' `W AA ; process:PID' The process exited, and AA is the exit status. This is only applicable to certain targets. The second form of the response, including the process ID of the exited process, can be used only when GDB has reported support for multiprocess protocol extensions; see *Note multiprocess extensions::. Both AA and PID are formatted as big-endian hex strings. `X AA' `X AA ; process:PID' The process terminated with signal AA. The second form of the response, including the process ID of the terminated process, can be used only when GDB has reported support for multiprocess protocol extensions; see *Note multiprocess extensions::. Both AA and PID are formatted as big-endian hex strings. `w AA ; TID' The thread exited, and AA is the exit status. This response should not be sent by default; GDB requests it with either the *Note QThreadEvents:: or *Note QThreadOptions:: packets. See also *Note thread create event:: above. AA is formatted as a big-endian hex string. `N' There are no resumed threads left in the target. In other words, even though the process is alive, the last resumed thread has exited. For example, say the target process has two threads: thread 1 and thread 2. The client leaves thread 1 stopped, and resumes thread 2, which subsequently exits. At this point, even though the process is still alive, and thus no `W' stop reply is sent, no thread is actually executing either. The `N' stop reply thus informs the client that it can stop waiting for stop replies. This packet should not be sent by default; older GDB versions did not support it. GDB requests it, by supplying an appropriate `qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate `qSupported' feature indicating support. `O XX...' `XX...' is hex encoding of ASCII data, to be written as the program's console output. This can happen at any time while the program is running and the debugger should continue to wait for `W', `T', etc. This reply is not permitted in non-stop mode. `F CALL-ID,PARAMETER...' CALL-ID is the identifier which says which host system call should be called. This is just the name of the function. Translation into the correct system call is only applicable as it's defined in GDB. *Note File-I/O Remote Protocol Extension::, for a list of implemented system calls. `PARAMETER...' is a list of parameters as defined for this very system call. The target replies with this packet when it expects GDB to call a host system call on behalf of the target. GDB replies with an appropriate `F' packet and keeps up waiting for the next reply packet from the target. The latest `C', `c', `S' or `s' action is expected to be continued. *Note File-I/O Remote Protocol Extension::, for more details.  File: gdb.info, Node: General Query Packets, Next: Architecture-Specific Protocol Details, Prev: Stop Reply Packets, Up: Remote Protocol E.5 General Query Packets ========================= Packets starting with `q' are "general query packets"; packets starting with `Q' are "general set packets". General query and set packets are a semi-unified form for retrieving and sending information to and from the stub. The initial letter of a query or set packet is followed by a name indicating what sort of thing the packet applies to. For example, GDB may use a `qSymbol' packet to exchange symbol definitions with the stub. These packet names follow some conventions: * The name must not contain commas, colons or semicolons. * Most GDB query and set packets have a leading upper case letter. * The names of custom vendor packets should use a company prefix, in lower case, followed by a period. For example, packets designed at the Acme Corporation might begin with `qacme.foo' (for querying foos) or `Qacme.bar' (for setting bars). The name of a query or set packet should be separated from any parameters by a `:'; the parameters themselves should be separated by `,' or `;'. Stubs must be careful to match the full packet name, and check for a separator or the end of the packet, in case two packet names share a common prefix. New packets should not begin with `qC', `qP', or `qL'(1). Like the descriptions of the other packets, each description here has a template showing the packet's overall syntax, followed by an explanation of the packet's meaning. We include spaces in some of the templates for clarity; these are not part of the packet's syntax. No GDB packet uses spaces to separate its components. Here are the currently defined query and set packets: `QAgent:1' `QAgent:0' Turn on or off the agent as a helper to perform some debugging operations delegated from GDB (*note Control Agent::). `QAllow:OP:VAL...' Specify which operations GDB expects to request of the target, as a semicolon-separated list of operation name and value pairs. Possible values for OP include `WriteReg', `WriteMem', `InsertBreak', `InsertTrace', `InsertFastTrace', and `Stop'. VAL is either 0, indicating that GDB will not request the operation, or 1, indicating that it may. (The target can then use this to set up its own internals optimally, for instance if the debugger never expects to insert breakpoints, it may not need to install its own trap handler.) `qC' Return the current thread ID. Reply: `QC THREAD-ID' Where THREAD-ID is a thread ID as documented in *Note thread-id syntax::. `(anything else)' Any other reply implies the old thread ID. `qCRC:ADDR,LENGTH' Compute the CRC checksum of a block of memory using CRC-32 defined in IEEE 802.3. The CRC is computed byte at a time, taking the most significant bit of each byte first. The initial pattern code `0xffffffff' is used to ensure leading zeros affect the CRC. _Note:_ This is the same CRC used in validating separate debug files (*note Debugging Information in Separate Files: Separate Debug Files.). However the algorithm is slightly different. When validating separate debug files, the CRC is computed taking the _least_ significant bit of each byte first, and the final result is inverted to detect trailing zeros. Reply: `C CRC32' The specified memory region's checksum is CRC32. `QDisableRandomization:VALUE' Some target operating systems will randomize the virtual address space of the inferior process as a security feature, but provide a feature to disable such randomization, e.g. to allow for a more deterministic debugging experience. On such systems, this packet with a VALUE of 1 directs the target to disable address space randomization for processes subsequently started via `vRun' packets, while a packet with a VALUE of 0 tells the target to enable address space randomization. This packet is only available in extended mode (*note extended mode::). Reply: `OK' The request succeeded. This packet is not probed by default; the remote stub must request it, by supplying an appropriate `qSupported' response (*note qSupported::). This should only be done on targets that actually support disabling address space randomization. `QStartupWithShell:VALUE' On UNIX-like targets, it is possible to start the inferior using a shell program. This is the default behavior on both GDB and `gdbserver' (*note set startup-with-shell::). This packet is used to inform `gdbserver' whether it should start the inferior using a shell or not. If VALUE is `0', `gdbserver' will not use a shell to start the inferior. If VALUE is `1', `gdbserver' will use a shell to start the inferior. All other values are considered an error. This packet is only available in extended mode (*note extended mode::). Reply: `OK' The request succeeded. This packet is not probed by default; the remote stub must request it, by supplying an appropriate `qSupported' response (*note qSupported::). This should only be done on targets that actually support starting the inferior using a shell. Use of this packet is controlled by the `set startup-with-shell' command; *note set startup-with-shell::. `QEnvironmentHexEncoded:HEX-VALUE' On UNIX-like targets, it is possible to set environment variables that will be passed to the inferior during the startup process. This packet is used to inform `gdbserver' of an environment variable that has been defined by the user on GDB (*note set environment::). The packet is composed by HEX-VALUE, an hex encoded representation of the NAME=VALUE format representing an environment variable. The name of the environment variable is represented by NAME, and the value to be assigned to the environment variable is represented by VALUE. If the variable has no value (i.e., the value is `null'), then VALUE will not be present. This packet is only available in extended mode (*note extended mode::). Reply: `OK' The request succeeded. This packet is not probed by default; the remote stub must request it, by supplying an appropriate `qSupported' response (*note qSupported::). This should only be done on targets that actually support passing environment variables to the starting inferior. This packet is related to the `set environment' command; *note set environment::. `QEnvironmentUnset:HEX-VALUE' On UNIX-like targets, it is possible to unset environment variables before starting the inferior in the remote target. This packet is used to inform `gdbserver' of an environment variable that has been unset by the user on GDB (*note unset environment::). The packet is composed by HEX-VALUE, an hex encoded representation of the name of the environment variable to be unset. This packet is only available in extended mode (*note extended mode::). Reply: `OK' The request succeeded. This packet is not probed by default; the remote stub must request it, by supplying an appropriate `qSupported' response (*note qSupported::). This should only be done on targets that actually support passing environment variables to the starting inferior. This packet is related to the `unset environment' command; *note unset environment::. `QEnvironmentReset' On UNIX-like targets, this packet is used to reset the state of environment variables in the remote target before starting the inferior. In this context, reset means unsetting all environment variables that were previously set by the user (i.e., were not initially present in the environment). It is sent to `gdbserver' before the `QEnvironmentHexEncoded' (*note QEnvironmentHexEncoded::) and the `QEnvironmentUnset' (*note QEnvironmentUnset::) packets. This packet is only available in extended mode (*note extended mode::). Reply: `OK' The request succeeded. This packet is not probed by default; the remote stub must request it, by supplying an appropriate `qSupported' response (*note qSupported::). This should only be done on targets that actually support passing environment variables to the starting inferior. `QSetWorkingDir:[DIRECTORY]' This packet is used to inform the remote server of the intended current working directory for programs that are going to be executed. The packet is composed by DIRECTORY, an hex encoded representation of the directory that the remote inferior will use as its current working directory. If DIRECTORY is an empty string, the remote server should reset the inferior's current working directory to its original, empty value. This packet is only available in extended mode (*note extended mode::). Reply: `OK' The request succeeded. `qfThreadInfo' `qsThreadInfo' Obtain a list of all active thread IDs from the target (OS). Since there may be too many active threads to fit into one reply packet, this query works iteratively: it may require more than one query/reply sequence to obtain the entire list of threads. The first query of the sequence will be the `qfThreadInfo' query; subsequent queries in the sequence will be the `qsThreadInfo' query. NOTE: This packet replaces the `qL' query (see below). Reply: `m THREAD-ID' A single thread ID `m THREAD-ID,THREAD-ID...' a comma-separated list of thread IDs `l' (lower case letter `L') denotes end of list. In response to each query, the target will reply with a list of one or more thread IDs, separated by commas. GDB will respond to each reply with a request for more thread ids (using the `qs' form of the query), until the target responds with `l' (lower-case ell, for "last"). Refer to *Note thread-id syntax::, for the format of the THREAD-ID fields. _Note: GDB will send the `qfThreadInfo' query during the initial connection with the remote target, and the very first thread ID mentioned in the reply will be stopped by GDB in a subsequent message. Therefore, the stub should ensure that the first thread ID in the `qfThreadInfo' reply is suitable for being stopped by GDB._ `qGetTLSAddr:THREAD-ID,OFFSET,LM' Fetch the address associated with thread local storage specified by THREAD-ID, OFFSET, and LM. THREAD-ID is the thread ID associated with the thread for which to fetch the TLS address. *Note thread-id syntax::. OFFSET is the (big endian, hex encoded) offset associated with the thread local variable. (This offset is obtained from the debug information associated with the variable.) LM is the (big endian, hex encoded) OS/ABI-specific encoding of the load module associated with the thread local storage. For example, a GNU/Linux system will pass the link map address of the shared object associated with the thread local storage under consideration. Other operating environments may choose to represent the load module differently, so the precise meaning of this parameter will vary. Reply: `XX...' Hex encoded (big endian) bytes representing the address of the thread local storage requested. `qGetTIBAddr:THREAD-ID' Fetch address of the Windows OS specific Thread Information Block. THREAD-ID is the thread ID associated with the thread. Reply: `XX...' Hex encoded (big endian) bytes representing the linear address of the thread information block. `qL STARTFLAG THREADCOUNT NEXTTHREAD' Obtain thread information from RTOS. Where: STARTFLAG (one hex digit) is one to indicate the first query and zero to indicate a subsequent query; THREADCOUNT (two hex digits) is the maximum number of threads the response packet can contain; and NEXTTHREAD (eight hex digits), for subsequent queries (STARTFLAG is zero), is returned in the response as ARGTHREAD. Don't use this packet; use the `qfThreadInfo' query instead (see above). Reply: `qM COUNT DONE ARGTHREAD THREAD...' Where: COUNT (two hex digits) is the number of threads being returned; DONE (one hex digit) is zero to indicate more threads and one indicates no further threads; ARGTHREADID (eight hex digits) is NEXTTHREAD from the request packet; THREAD... is a sequence of thread IDs, THREADID (eight hex digits), from the target. See `remote.c:parse_threadlist_response()'. `qMemTags:START ADDRESS,LENGTH:TYPE' Fetch memory tags of type TYPE from the address range [START ADDRESS, START ADDRESS + LENGTH). The target is responsible for calculating how many tags will be returned, as this is architecture-specific. START ADDRESS is the starting address of the memory range. LENGTH is the length, in bytes, of the memory range. TYPE is the type of tag the request wants to fetch. The type is a signed integer. GDB will only send this packet if the stub has advertised support for memory tagging via `qSupported'. Reply: `MXX...' Hex encoded sequence of uninterpreted bytes, XX..., representing the tags found in the requested memory range. `qIsAddressTagged:ADDRESS' ---------- Footnotes ---------- (1) The `qP' and `qL' packets predate these conventions, and have arguments without any terminator for the packet name; we suspect they are in widespread use in places that are difficult to upgrade. The `qC' packet has no arguments, but some existing stubs (e.g. RedBoot) are known to not check for the end of the packet. @ 1.3 log @revert previous @ text @d1 2 a2 1 This is gdb.info, produced by makeinfo version 7.1 from gdb.texinfo. d4 7 a10 1 Copyright © 1988-2024 Free Software Foundation, Inc. a21 5 INFO-DIR-SECTION Software development START-INFO-DIR-ENTRY * Gdb: (gdb). The GNU debugger. * gdbserver: (gdb) Server. The GNU debugging server. END-INFO-DIR-ENTRY d25 2 a26 2 This is the Tenth Edition, of ‘Debugging with GDB: the GNU Source-Level Debugger’ for GDB (GDB) Version 15.1. d28 1 a28 1 Copyright © 1988-2024 Free Software Foundation, Inc. d42 1 a42 1 File: gdb.info, Node: Top, Next: Summary, Up: (dir) d97 1 d112 1 a112 1 * Debuginfod:: Download debugging resources with ‘debuginfod’ d122 1 a122 1 File: gdb.info, Node: Summary, Next: Sample Session, Up: Top d134 1 a134 1 • Start your program, specifying anything that might affect its d137 1 a137 1 • Make your program stop on specified conditions. d139 1 a139 1 • Examine what has happened, when your program has stopped. d141 1 a141 1 • Change things in your program, so you can experiment with d145 2 a146 2 information, see *note Supported Languages: Supported Languages. For more information, see *note C and C++: C. d148 1 a148 1 Support for D is partial. For information on D, see *note D: D. d151 1 a151 1 *note Modula-2: Modula-2. d154 1 a154 1 *note OpenCL C: OpenCL C. d161 2 a162 2 GDB can be used to debug programs written in Fortran, although it may be necessary to refer to some variables with a trailing underscore. d179 1 a179 1 GDB is “free software”, protected by the GNU General Public License d182 4 a185 4 to modify that copy (which means that they must get access to the source code), and the freedom to distribute further copies. Typical software companies use copyrights to limit your freedoms; the Free Software Foundation uses the GPL to preserve these freedoms. d208 2 a209 2 copying, no modification, source files not available--which exclude them from the free software world. d212 4 a215 4 far from the last. Many times we have heard a GNU user eagerly describe a manual that he is writing, his intended contribution to the community, only to learn that he had ruined everything by signing a publication contract to make it non-free. d226 3 a228 3 free software. Redistribution (including the normal kinds of commercial redistribution) must be permitted, so that the manual can accompany every copy of the program, both on-line and on paper. d238 5 a242 5 acceptable. For example, requirements to preserve the original author's copyright notice, the distribution terms, or the list of authors, are ok. It is also no problem to require modified versions to include notice that they were modified. Even entire sections that may not be deleted or changed are acceptable, as long as they deal with d244 2 a245 2 acceptable because they don't obstruct the community's normal use of the manual. d247 2 a248 2 However, it must be possible to modify all the _technical_ content of the manual, and then distribute the result in all the usual media, d254 5 a258 5 lose manuals to proprietary publishing. If we spread the word that free software needs free reference manuals and free tutorials, perhaps the next person who wants to contribute by writing documentation will realize, before it is too late, that only free manuals contribute to the free software community. d263 4 a266 4 have to let the publisher decide. Some commercial publishers will use a free license if you insist, but they will not propose the option; it is up to you to raise the issue and say firmly that this is what you want. If the publisher you are dealing with refuses, please try other d281 1 a281 1 . d292 3 a294 3 free software is that everyone is free to contribute to it; with regret, we cannot actually acknowledge everyone here. The file ‘ChangeLog’ in the GDB distribution approximates a blow-by-blow account. d305 6 a310 6 Blandy (release 4.18); Jason Molenda (release 4.17); Stan Shebs (release 4.14); Fred Fish (releases 4.16, 4.15, 4.13, 4.12, 4.11, 4.10, and 4.9); Stu Grossman and John Gilmore (releases 4.8, 4.7, 4.6, 4.5, and 4.4); John Gilmore (releases 4.3, 4.2, 4.1, 4.0, and 3.9); Jim Kingdon (releases 3.5, 3.4, and 3.3); and Randy Smith (releases 3.2, 3.1, and 3.0). d317 2 a318 2 Berlin. James Clark wrote the GNU C++ demangler. Early work on C++ was by Peter TerMaat (who also did much general update work leading to d322 1 a322 1 formats; BFD was a joint project of David V. Henkel-Wallace, Rich d332 11 a342 11 support. Jean-Daniel Fekete contributed Sun 386i support. Chris Hanson improved the HP9000 support. Noboyuki Hikichi and Tomoyuki Hasei contributed Sony/News OS 3 support. David Johnson contributed Encore Umax support. Jyrki Kuoppala contributed Altos 3068 support. Jeff Law contributed HP PA and SOM support. Keith Packard contributed NS32K support. Doug Rabson contributed Acorn Risc Machine support. Bob Rusk contributed Harris Nighthawk CX-UX support. Chris Smith contributed Convex support (and Fortran debugging). Jonathan Stone contributed Pyramid support. Michael Tiemann contributed SPARC support. Tim Tucker contributed support for the Gould NP1 and Gould Powernode. Pace Willison contributed Intel 386 support. Jay Vosburgh contributed d355 2 a356 2 and ARM contributed remote debugging modules for the i960, VxWorks, A29K UDI, and RDI targets, respectively. d367 2 a368 2 Hitachi America (now Renesas America), Ltd. sponsored the support for H8/300, H8/500, and Super-H processors. d396 4 a399 4 compiler, and the Text User Interface (nee Terminal User Interface): Ben Krepp, Richard Title, John Bishop, Susan Macchia, Kathy Mann, Satish Pai, India Paul, Steve Rehrauer, and Elena Zannoni. Kim Haase provided HP-specific information in this manual. d438 7 a444 6 unwinders. The architecture-specific changes, each involving a complete rewrite of the architecture's frame code, were carried out by Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich Weigand. d480 3 a482 3 You can use this manual at your leisure to read all about GDB. However, a handful of commands are enough to get started using the debugger. This chapter illustrates those commands. d484 1 a484 1 One of the preliminary versions of GNU ‘m4’ (a generic macro d487 6 a492 6 definition within another stop working. In the following short ‘m4’ session, we define a macro ‘foo’ which expands to ‘0000’; we then use the ‘m4’ built-in ‘defn’ to define ‘bar’ as the same thing. However, when we change the open quote string to ‘’ and the close quote string to ‘’, the same procedure fails to define a new synonym ‘baz’: d530 4 a533 3 We need to see how the ‘m4’ built-in ‘changequote’ works. Having looked at the source, we know the relevant subroutine is ‘m4_changequote’, so we set a breakpoint there with the GDB ‘break’ command. d538 2 a539 2 Using the ‘run’ command, we start ‘m4’ running under GDB control; as long as control does not reach the ‘m4_changequote’ subroutine, the d549 2 a550 2 To trigger the breakpoint, we call ‘changequote’. GDB suspends execution of ‘m4’, displaying information about the context where it d559 1 a559 1 Now we use the command ‘n’ (‘next’) to advance execution to the next d566 2 a567 2 ‘set_quotes’ looks like a promising subroutine. We can go into it by using the command ‘s’ (‘step’) instead of ‘next’. ‘step’ goes to the d569 1 a569 1 ‘set_quotes’. d576 1 a576 1 The display that shows the subroutine where ‘m4’ is now suspended (and d578 3 a580 3 the stack. We can use the ‘backtrace’ command (which can also be spelled ‘bt’), to see where we are in the stack as a whole: the ‘backtrace’ command displays a stack frame for each active subroutine. d594 2 a595 2 times, we can use ‘s’; the next two times we use ‘n’ to avoid falling into the ‘xstrdup’ subroutine. d609 2 a610 2 ‘lquote’ and ‘rquote’ to see if they are in fact the new left and right quotes we specified. We use the command ‘p’ (‘print’) to see their d618 3 a620 3 ‘lquote’ and ‘rquote’ are indeed the new left and right quotes. To look at some context, we can display ten lines of source surrounding the current line with the ‘l’ (‘list’) command. d636 1 a636 1 Let us step past the two lines that set ‘len_lquote’ and ‘len_rquote’, d648 3 a650 3 That certainly looks wrong, assuming ‘len_lquote’ and ‘len_rquote’ are meant to be the lengths of ‘lquote’ and ‘rquote’ respectively. We can set them to better values using the ‘p’ command, since it can print the d659 3 a661 3 Is that enough to fix the problem of using the new quotes with the ‘m4’ built-in ‘defn’? We can allow ‘m4’ to continue executing with the ‘c’ (‘continue’) command, and then try the example that caused trouble d674 1 a674 1 lengths. We allow ‘m4’ exit by giving it an EOF as input: d679 2 a680 2 The message ‘Program exited normally.’ is from GDB; it indicates ‘m4’ has finished executing. We can end our GDB session with the GDB ‘quit’ d693 3 a695 2 • type ‘gdb’ to start GDB. • type ‘quit’, ‘exit’ or ‘Ctrl-d’ to exit. d710 1 a710 1 Invoke GDB by running the program ‘gdb’. Once started, GDB reads d713 1 a713 1 You can also run ‘gdb’ with a variety of arguments and options, to d731 1 a731 1 option ‘-p’, if you want to debug a running process: d736 1 a736 1 would attach GDB to process ‘1234’. With option ‘-p’ you can omit the d745 3 a747 3 You can optionally have ‘gdb’ pass any arguments after the executable file to the inferior using ‘--args’. This option stops option processing. d749 2 a750 2 This will cause ‘gdb’ to debug ‘gcc’, and to set ‘gcc’'s command-line arguments (*note Arguments::) to ‘-O2 -c foo.c’. d752 3 a754 3 You can run ‘gdb’ without printing the front material, which describes GDB's non-warranty, by specifying ‘--silent’ (or ‘-q’/‘--quiet’): d758 2 a759 2 You can further control how GDB starts up by using command-line options. GDB itself can remind you of the options available. d765 2 a766 2 to display all available options and briefly describe their use (‘gdb -h’ is a shorter equivalent). d769 1 a769 1 sequential order. The order makes a difference when the ‘-x’ option is d785 16 a800 16 When GDB starts, it reads any arguments other than options as specifying an executable file and core file (or process ID). This is the same as if the arguments were specified by the ‘-se’ and ‘-c’ (or ‘-p’) options respectively. (GDB reads the first argument that does not have an associated option flag as equivalent to the ‘-se’ option followed by that argument; and the second argument that does not have an associated option flag, if any, as equivalent to the ‘-c’/‘-p’ option followed by that argument.) If the second argument begins with a decimal digit, GDB will first attempt to attach to it as a process, and if that fails, attempt to open it as a corefile. If you have a corefile whose name begins with a digit, you can prevent GDB from treating it as a pid by prefixing it with ‘./’, e.g. ‘./12345’. If GDB has not been configured to included core file support, such as for most embedded targets, then it will complain about a second argument and ignore it. d802 1 a802 1 For the ‘-s’, ‘-e’, and ‘-se’ options, and their long form d804 1 a804 1 and/or executable file is the same as that used by the ‘file’ command. d809 3 a811 3 them, so long as enough of the option is present to be unambiguous. (If you prefer, you can flag option arguments with ‘--’ rather than ‘-’, though we illustrate the more usual convention.) d813 2 a814 2 ‘-symbols FILE’ ‘-s FILE’ d817 2 a818 2 ‘-exec FILE’ ‘-e FILE’ d822 1 a822 1 ‘-se FILE’ d825 2 a826 2 ‘-core FILE’ ‘-c FILE’ d829 3 a831 3 ‘-pid NUMBER’ ‘-p NUMBER’ Connect to process ID NUMBER, as with the ‘attach’ command. d833 2 a834 2 ‘-command FILE’ ‘-x FILE’ d836 1 a836 1 evaluated exactly as the ‘source’ command would. *Note Command d839 2 a840 2 ‘-eval-command COMMAND’ ‘-ex COMMAND’ d844 1 a844 1 It may also be interleaved with ‘-command’ as required. d849 2 a850 2 ‘-init-command FILE’ ‘-ix FILE’ d854 4 a857 4 ‘-init-eval-command COMMAND’ ‘-iex COMMAND’ Execute a single GDB command before loading the inferior (but after loading gdbinit files). *Note Startup::. d859 2 a860 2 ‘-early-init-command FILE’ ‘-eix FILE’ d864 2 a865 2 ‘-early-init-eval-command COMMAND’ ‘-eiex COMMAND’ d869 2 a870 2 ‘-directory DIRECTORY’ ‘-d DIRECTORY’ d873 2 a874 2 ‘-r’ ‘-readnow’ d880 1 a880 1 ‘--readnever’ d895 2 a896 2 You can run GDB in various alternative modes--for example, in batch mode or quiet mode. d898 2 a899 2 ‘-nx’ ‘-n’ d903 1 a903 1 ‘-nh’ d909 3 a911 3 ‘-quiet’ ‘-silent’ ‘-q’ d915 3 a917 3 This can also be enabled using ‘set startup-quietly on’. The default is ‘off’. Use ‘show startup-quietly’ to see the current setting. Place ‘set startup-quietly on’ into your early d921 4 a924 4 ‘-batch’ Run in batch mode. Exit with status ‘0’ after processing all the command files specified with ‘-x’ (and all commands from initialization files, if not inhibited with ‘-n’). Exit with d928 1 a928 1 as if ‘set confirm off’ were in effect (*note Messages/Warnings::). d931 2 a932 2 to download and run a program on another computer; in order to make this more useful, the message d939 4 a942 4 ‘-batch-silent’ Run in batch mode exactly like ‘-batch’, but totally silently. All GDB output to ‘stdout’ is prevented (‘stderr’ is unaffected). This is much quieter than ‘-silent’ and would be useless for an d945 2 a946 2 This is particularly useful when using targets that give ‘Loading section’ messages, for example. d949 1 a949 1 writing directly to ‘stdout’, will also be made silent. d951 1 a951 1 ‘-return-child-result’ d956 1 a956 1 • GDB exits abnormally. E.g., due to an incorrect argument or d958 5 a962 3 it would have been without ‘-return-child-result’. • The user quits with an explicit value. E.g., ‘quit 1’. • The child process never runs, or is not allowed to terminate, d965 2 a966 2 This option is useful in conjunction with ‘-batch’ or ‘-batch-silent’, when GDB is being used as a remote program loader d969 2 a970 2 ‘-nowindows’ ‘-nw’ d975 2 a976 2 ‘-windows’ ‘-w’ d980 1 a980 1 ‘-cd DIRECTORY’ d984 2 a985 2 ‘-data-directory DIRECTORY’ ‘-D DIRECTORY’ d989 2 a990 2 ‘-fullname’ ‘-f’ d993 17 a1009 16 standard, recognizable fashion each time a stack frame is displayed (which includes each time your program stops). This recognizable format looks like two ‘\032’ characters, followed by the file name, line number and character position separated by colons, and a newline. The Emacs-to-GDB interface program uses the two ‘\032’ characters as a signal to display the source code for the frame. ‘-annotate LEVEL’ This option sets the “annotation level” inside GDB. Its effect is identical to using ‘set annotate LEVEL’ (*note Annotations::). The annotation LEVEL controls how much information GDB prints together with its prompt, values of expressions, source lines, and other types of output. Level 0 is the normal, level 1 is for use when GDB is run as a subprocess of GNU Emacs, level 3 is the maximum annotation suitable for programs that control GDB, and level 2 has been deprecated. d1014 1 a1014 1 ‘--args’ d1019 2 a1020 2 ‘-baud BPS’ ‘-b BPS’ d1024 1 a1024 1 ‘-l TIMEOUT’ d1028 2 a1029 2 ‘-tty DEVICE’ ‘-t DEVICE’ d1032 2 a1033 2 ‘-tui’ Activate the “Text User Interface” when starting. The Text User d1035 3 a1037 3 source, assembly, registers and GDB command outputs (*note GDB Text User Interface: TUI.). Do not use this option if you run GDB from Emacs (*note Using GDB under GNU Emacs: Emacs.). d1039 1 a1039 1 ‘-interpreter INTERP’ d1045 6 a1050 5 ‘--interpreter=mi’ (or ‘--interpreter=mi3’) causes GDB to use the “GDB/MI interface” version 3 (*note The GDB/MI Interface: GDB/MI.) included since GDB version 9.1. GDB/MI version 2 (‘mi2’), included in GDB 6.0 and version 1 (‘mi1’), included in GDB 5.3, are also available. Earlier GDB/MI interfaces are no longer supported. d1052 1 a1052 1 ‘-write’ d1054 1 a1054 1 This is equivalent to the ‘set write on’ command inside GDB (*note d1057 1 a1057 1 ‘-statistics’ d1061 1 a1061 1 ‘-version’ d1065 1 a1065 1 ‘-configuration’ d1070 1 d1083 1 a1083 1 into an early initialization file, see *note Initialization d1086 4 a1089 4 3. Executes commands and command files specified by the ‘-eiex’ and ‘-eix’ command line options in their specified order. Only a restricted set of commands can be used with ‘-eiex’ and ‘eix’, see *note Initialization Files::, for details. d1102 5 a1106 4 7. Executes commands and command files specified by the ‘-iex’ and ‘-ix’ options in their specified order. Usually you should use the ‘-ex’ and ‘-x’ options instead, but this way you can apply settings before GDB init files get executed and before inferior gets loaded. d1111 2 a1112 2 any) in the current working directory as long as ‘set auto-load local-gdbinit’ is set to ‘on’ (*note Init File in the Current d1117 1 a1117 1 you invoke GDB. *Note Init File in the Current Directory during d1120 1 a1120 1 10. If the command line specified a program to debug, or a process to d1122 2 a1123 2 provided for the program or for its loaded shared libraries. *Note Auto-loading::. d1125 2 a1126 2 If you wish to disable the auto-loading during startup, you must do something like the following: d1130 1 a1130 1 Option ‘-ex’ does not work because the auto-loading is then turned d1133 2 a1134 2 11. Executes commands and command files specified by the ‘-ex’ and ‘-x’ options in their specified order. *Note Command Files::, for d1137 1 a1137 1 12. Reads the command history recorded in the “history file”. *Note d1148 3 a1150 3 initialization files. These initialization files use the same syntax as “command files” (*note Command Files::) and are processed by GDB in the same way. d1152 2 a1153 2 To display the list of initialization files loaded by GDB at startup, in the order they will be loaded, you can use ‘gdb --help’. d1155 1 a1155 1 The “early initialization” file is loaded very early in GDB's d1157 4 a1160 4 has been initialized, and before the default target (*note Targets::) is initialized. Only ‘set’ or ‘source’ commands should be placed into an early initialization file, and the only ‘set’ commands that can be used are those that control how GDB starts up. d1166 4 a1169 4 passed to ‘--early-init-command’ or ‘-eix’ are also early initialization files, with the same command restrictions. Only commands that can appear in an early initialization file should be passed to ‘--early-init-eval-command’ or ‘-eiex’. d1171 1 a1171 1 In contrast, the “general initialization” files are processed later, d1175 1 a1175 1 Throughout the rest of this document the term “initialization file” d1178 2 a1179 2 will specifically mention that it is the early initialization file being discussed. d1183 1 a1183 1 ‘set complaints’) can affect subsequent processing of command line d1200 8 a1207 6 • The file ‘gdb/gdbearlyinit’ within the directory pointed to by the environment variable ‘XDG_CONFIG_HOME’, if it is defined. • The file ‘.config/gdb/gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is defined. • The file ‘.gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is defined. d1210 2 a1211 2 • The file ‘Library/Preferences/gdb/gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is d1213 3 a1215 2 • The file ‘.gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is defined. d1218 1 a1218 1 file from being loaded using the ‘-nx’ or ‘-nh’ command line options, d1224 2 a1225 2 There are two locations that are searched for system wide initialization files. Both of these locations are always checked: d1227 1 a1227 1 ‘system.gdbinit’ d1229 1 a1229 1 specified with the ‘--with-system-gdbinit’ configure option (*note d1233 1 a1233 1 ‘system.gdbinit.d’ d1235 1 a1235 1 specified with the ‘--with-system-gdbinit-dir’ configure option d1237 7 a1243 6 loaded in alphabetical order immediately after ‘system.gdbinit’ (if enabled) when GDB starts, before command line options have been processed. Files need to have a recognized scripting language extension (‘.py’/‘.scm’) or be named with a ‘.gdb’ extension to be interpreted as regular GDB commands. GDB will not recurse into any subdirectories of this directory. d1246 1 a1246 1 being loaded using the ‘-nx’ command line option, *note Choosing Modes: d1254 3 a1256 3 of locations that GDB will search in the home directory, these locations are searched in order and GDB will load the first file that it finds, and subsequent locations will not be checked. d1259 5 a1263 3 ‘$XDG_CONFIG_HOME/gdb/gdbinit’ ‘$HOME/.config/gdb/gdbinit’ ‘$HOME/.gdbinit’ d1266 3 a1268 2 ‘$HOME/Library/Preferences/gdb/gdbinit’ ‘$HOME/.gdbinit’ d1271 1 a1271 1 being loaded using the ‘-nx’ or ‘-nh’ command line options, *note d1274 2 a1275 2 The DJGPP port of GDB uses the name ‘gdb.ini’ instead of ‘.gdbinit’ or ‘gdbinit’, due to the limitations of file names imposed by DOS d1277 1 a1277 1 finds a ‘gdb.ini’ file in your home directory, it warns you about that d1283 4 a1286 4 GDB will check the current directory for a file called ‘.gdbinit’. It is loaded last, after command line options other than ‘-x’ and ‘-ex’ have been processed. The command line options ‘-x’ and ‘-ex’ are processed last, after ‘.gdbinit’ has been loaded, *note Choosing Files: d1293 1 a1293 1 from being loaded using the ‘-nx’ command line option, *note Choosing d1299 1 a1299 1 by the ‘HOME’ environment variable. d1302 1 a1302 1 by the ‘HOME’ environment variable. d1310 5 a1314 5 ‘quit [EXPRESSION]’ ‘exit [EXPRESSION]’ ‘q’ To exit GDB, use the ‘quit’ command (abbreviated ‘q’), the ‘exit’ command, or type an end-of-file character (usually ‘Ctrl-d’). If d1319 5 a1323 5 An interrupt (often ‘Ctrl-c’) does not exit from GDB, but rather terminates the action of any GDB command that is in progress and returns to GDB command level. It is safe to type the interrupt character at any time because GDB does not allow it to take effect until a time when it is safe. d1326 1 a1326 1 you can release it with the ‘detach’ command (*note Debugging an d1337 1 a1337 1 ‘shell’ command. d1339 2 a1340 2 ‘shell COMMAND-STRING’ ‘!COMMAND-STRING’ d1342 4 a1345 4 needed between ‘!’ and COMMAND-STRING. On GNU and Unix systems, the environment variable ‘SHELL’, if it exists, determines which shell to run. Otherwise GDB uses the default shell (‘/bin/sh’ on GNU and Unix systems, ‘cmd.exe’ on MS-Windows, ‘COMMAND.COM’ on d1349 1 a1349 1 ‘$_shell’ convenience function. *Note $_shell convenience function::. d1351 2 a1352 2 The utility ‘make’ is often needed in development environments. You do not have to use the ‘shell’ command for this purpose in GDB: d1354 8 a1361 8 ‘make MAKE-ARGS’ Execute the ‘make’ program with the specified arguments. This is equivalent to ‘shell make MAKE-ARGS’. ‘pipe [COMMAND] | SHELL_COMMAND’ ‘| [COMMAND] | SHELL_COMMAND’ ‘pipe -d DELIM COMMAND DELIM SHELL_COMMAND’ ‘| -d DELIM COMMAND DELIM SHELL_COMMAND’ d1363 2 a1364 2 no space is needed around ‘|’. If no COMMAND is provided, the last command executed is repeated. d1366 1 a1366 1 In case the COMMAND contains a ‘|’, the option ‘-d DELIM’ can be d1399 1 a1399 1 The convenience variables ‘$_shell_exitcode’ and ‘$_shell_exitsignal’ d1401 1 a1401 1 launched by ‘shell’, ‘make’, ‘pipe’ and ‘|’. *Note Convenience d1413 4 a1416 3 ‘set logging enabled [on|off]’ Enable or disable logging. ‘set logging file FILE’ d1418 7 a1424 5 ‘gdb.txt’. ‘set logging overwrite [on|off]’ By default, GDB will append to the logfile. Set ‘overwrite’ if you want ‘set logging enabled on’ to overwrite the logfile instead. ‘set logging redirect [on|off]’ d1426 1 a1426 1 logfile. Set ‘redirect’ if you want output to go only to the log d1428 2 a1429 1 ‘set logging debugredirect [on|off]’ d1431 4 a1434 3 logfile. Set ‘debugredirect’ if you want debug output to go only to the log file. ‘show logging’ d1437 2 a1438 2 You can also redirect the output of a GDB command to a shell command. *Note pipe::. d1470 3 a1472 3 command ‘step’ accepts an argument which is the number of times to step, as in ‘step 5’. You can also use the ‘step’ command with no arguments. Some commands do not allow any arguments. d1477 4 a1480 4 abbreviations are allowed; for example, ‘s’ is specially defined as equivalent to ‘step’ even though there are other commands whose names start with ‘s’. You can test abbreviations by using them as arguments to the ‘help’ command. d1483 5 a1487 4 previous command. Certain commands (for example, ‘run’) will not repeat this way; these are commands whose unintentional repetition might cause trouble and which you are unlikely to want to repeat. User-defined commands can disable this feature; see *note dont-repeat: Define. d1489 1 a1489 1 The ‘list’ and ‘x’ commands, when you repeat them with , d1494 4 a1497 4 in a way similar to the common utility ‘more’ (*note Screen Size: Screen Size.). Since it is easy to press one too many in this situation, GDB disables command repetition after any command that generates this sort of display. d1499 1 a1499 1 Any text from a ‘#’ to the end of the line is a comment; it does d1503 1 a1503 1 The ‘Ctrl-o’ binding is useful for repeating a complex sequence of d1515 2 a1516 2 variables or settings. These settings can be changed with the ‘set’ subcommands. For example, the ‘print’ command (*note Examining Data: d1518 2 a1519 2 the commands ‘set print elements NUMBER-OF-ELEMENTS’ and ‘set print array-indexes’, among others. d1531 1 a1531 1 The above ‘set print elements 10’ command changes the number of d1533 2 a1534 2 this limit of 10 to be used for printing ‘some_array’, then you must restore the limit back to 200, with ‘set print elements 200’. d1537 2 a1538 2 example, the ‘print’ command supports a number of options that allow overriding relevant global print settings as set by ‘set print’ d1544 1 a1544 1 Alternatively, you can use the ‘with’ command to change a setting d1547 2 a1548 2 ‘with SETTING [VALUE] [-- COMMAND]’ ‘w SETTING [VALUE] [-- COMMAND]’ d1551 2 a1552 2 SETTING is any setting you can change with the ‘set’ subcommands. VALUE is the value to assign to ‘setting’ while running ‘command’. d1557 1 a1557 1 (‘--’) separator. This is required because some settings accept d1567 3 a1569 3 The ‘with’ command is particularly useful when you want to override a setting while running user-defined commands, or commands defined in Python or Guile. *Note Extending GDB: Extending GDB. d1574 2 a1575 2 ‘with’ commands. For example, ‘with language ada -- with print elements 10’ temporarily changes the language to Ada and sets a d1578 1 d1598 2 a1599 2 GDB fills in the rest of the word ‘breakpoints’, since that is the only ‘info’ subcommand beginning with ‘bre’: d1603 2 a1604 2 You can either press at this point, to run the ‘info breakpoints’ command, or backspace and enter something else, if ‘breakpoints’ does d1606 3 a1608 3 ‘info breakpoints’ in the first place, you might as well just type immediately after ‘info bre’, to exploit command abbreviations rather than command completion). d1614 2 a1615 2 a breakpoint on a subroutine whose name begins with ‘make_’, but when you type ‘b make_’ GDB just sounds the bell. Typing again d1629 1 a1629 1 input (‘b make_’ in the example) so you can finish the command. d1631 2 a1632 2 If the command you are trying to complete expects either a keyword or a number to follow, then ‘NUMBER’ will be shown among the available d1639 1 a1639 1 Here, the option expects a number (e.g., ‘100’), not literal ‘NUMBER’. d1643 4 a1646 4 you can press ‘M-?’ rather than pressing twice. ‘M-?’ means ‘ ?’. You can type this either by holding down a key designated as the shift on your keyboard (if there is one) while typing ‘?’, or as followed by ‘?’. d1660 2 a1661 2 ‘set max-completions LIMIT’ ‘set max-completions unlimited’ d1668 3 a1670 2 completion slow. ‘show max-completions’ d1677 1 a1677 1 you may enclose words in ‘'’ (single quote marks) in GDB commands. d1681 3 a1683 3 This is because when completing expressions, GDB treats the ‘<’ character as word delimiter, assuming that it's the less-than comparison operator (*note C and C++ Operators: C Operators.). d1686 8 a1693 7 interactively using the ‘print’ or ‘call’ commands, you may need to distinguish whether you mean the version of ‘name’ that was specialized for ‘int’, ‘name()’, or the version that was specialized for ‘float’, ‘name()’. To use the word-completion facilities in this situation, type a single quote ‘'’ at the beginning of the function name. This alerts GDB that it may need to consider more information than usual when you press or ‘M-?’ to request word completion: d1710 3 a1712 3 don't need to distinguish whether you mean the version of ‘name’ that takes an ‘int’ parameter, ‘name(int)’, or the version that takes a ‘float’ parameter, ‘name(float)’. d1719 1 a1719 1 See *note quoting names:: for a description of other scenarios that d1722 3 a1724 3 For more information about overloaded functions, see *note C++ Expressions: C Plus Plus Expressions. You can use the command ‘set overload-resolution off’ to disable overload resolution; see *note GDB d1737 2 a1738 2 This is because the ‘gdb_stdout’ is a variable of the type ‘struct ui_file’ that is defined in GDB sources as follows: d1768 3 a1770 3 if the filename argument does not include any whitespace, double quotes, or single quotes, then for all commands the filename can be written as a simple string, for example: d1782 1 a1782 1 example the user is adding ‘/path/that contains/two spaces/’ to the d1794 3 a1796 3 For example, to load the file ‘/path/with spaces/to/a file’ with the ‘file’ command (*note Commands to Specify Files: Files.), you can escape the whitespace characters with a backslash: d1822 6 a1827 6 Some commands accept options starting with a leading dash. For example, ‘print -pretty’. Similarly to command names, you can abbreviate a GDB option to the first few letters of the option name, if that abbreviation is unambiguous, and you can also use the key to get GDB to fill out the rest of a word in an option (or to show you the alternatives available, if there is more than one possibility). d1833 3 a1835 3 abbreviations, e.g. ‘print -p’ (short for ‘print -pretty’ or printing negative ‘p’?), if you specify any command option, then you must use a double-dash (‘--’) delimiter to indicate the end of options. d1838 5 a1842 5 either ‘on’ or ‘off’. These are known as “boolean options”. Similarly to boolean settings commands--‘on’ and ‘off’ are the typical values, but any of ‘1’, ‘yes’ and ‘enable’ can also be used as "true" value, and any of ‘0’, ‘no’ and ‘disable’ can also be used as "false" value. You can also omit a "true" value, as it is implied by default. d1850 1 a1850 1 completing on ‘-’ after the command name. For example: d1864 1 a1864 1 Here, the option expects a number (e.g., ‘100’), not literal ‘NUMBER’. d1867 1 a1867 1 (For more on using the ‘print’ command, see *note Examining Data: d1876 2 a1877 2 You can always ask GDB itself for information on its commands, using the command ‘help’. d1879 4 a1882 4 ‘help’ ‘h’ You can use ‘help’ (abbreviated ‘h’) with no arguments to display a short list of named classes of commands: d1908 1 a1908 1 ‘help CLASS’ d1914 1 a1914 1 help display for the class ‘status’: d1936 2 a1937 2 ‘help COMMAND’ With a command name as ‘help’ argument, GDB displays a short d1946 5 a1950 5 ‘document’ command (*note document: Define.). GDB then considers this alias as different from the aliased command: this alias is not listed in the aliased command help output, and asking help for this alias will show the documentation provided for the alias instead of the documentation of the aliased command. d1952 2 a1953 2 ‘apropos [-v] REGEXP’ The ‘apropos’ command searches through all of the GDB commands and d1956 3 a1958 3 flag ‘-v’, which stands for ‘verbose’, indicates to output the full documentation of the matching commands and highlight the parts of the documentation matching REGEXP. For example: d1971 1 a1971 1 results in the below output, where ‘cut for 'thread apply’ is d1984 2 a1985 2 ‘complete ARGS’ The ‘complete ARGS’ command lists all the possible completions for d2000 6 a2005 6 In addition to ‘help’, you can use the GDB commands ‘info’ and ‘show’ to inquire about the state of your program, or the state of GDB itself. Each command supports many topics of inquiry; this manual introduces each of them in the appropriate context. The listings under ‘info’ and under ‘show’ in the Command, Variable, and Function Index point to all the sub-commands. *Note Command and Variable Index::. d2007 2 a2008 2 ‘info’ This command (abbreviated ‘i’) is for describing the state of your d2010 4 a2013 4 function with ‘info args’, list the registers currently in use with ‘info registers’, or list the breakpoints you have set with ‘info breakpoints’. You can get a complete list of the ‘info’ sub-commands with ‘help info’. d2015 1 a2015 1 ‘set’ d2017 2 a2018 2 variable with ‘set’. For example, you can set the GDB prompt to a $-sign with ‘set prompt $’. d2020 6 a2025 6 ‘show’ In contrast to ‘info’, ‘show’ is for describing the state of GDB itself. You can change most of the things you can ‘show’, by using the related command ‘set’; for example, you can control what number system is used for displays with ‘set radix’, or simply inquire which is currently in use with ‘show radix’. d2028 1 a2028 1 you can use ‘show’ with no arguments; you may also use ‘info set’. d2031 2 a2032 2 Here are several miscellaneous ‘show’ subcommands, all of which are exceptional in lacking corresponding ‘set’ commands: d2034 1 a2034 1 ‘show version’ d2036 7 a2042 7 information in GDB bug-reports. If multiple versions of GDB are in use at your site, you may need to determine which version of GDB you are running; as GDB evolves, new commands are introduced, and old ones may wither away. Also, many system vendors ship variant versions of GDB, and there are variant versions of GDB in GNU/Linux distributions as well. The version number is the same as the one announced when you start GDB. d2044 2 a2045 2 ‘show copying’ ‘info copying’ d2048 2 a2049 2 ‘show warranty’ ‘info warranty’ d2053 1 a2053 1 ‘show configuration’ d2056 2 a2057 2 ‘configure’ script and also configuration parameters detected automatically by ‘configure’. When reporting a GDB bug (*note GDB d2061 1 d2105 1 a2105 1 To request debugging information, specify the ‘-g’ option when you d2109 2 a2110 2 optimizations, using the ‘-O’ compiler option. However, some compilers are unable to handle the ‘-g’ and ‘-O’ options together. Using those d2114 1 a2114 1 GCC, the GNU C/C++ compiler, supports ‘-g’ with or without ‘-O’, d2116 1 a2116 1 _always_ use ‘-g’ whenever you compile a program. You may think your d2118 1 a2118 1 more information, see *note Optimized Code::. d2120 3 a2122 3 Older versions of the GNU C compiler permitted a variant option ‘-gg’ for debugging information. GDB no longer supports this format; if your GNU C compiler has this option, do not use it. d2126 4 a2129 4 preprocessor macros in the debugging information if you specify the ‘-g’ flag alone. Version 3.1 and later of GCC, the GNU C compiler, provides macro information if you are using the DWARF debugging format, and specify the option ‘-g3’. d2146 3 a2148 3 ‘run’ ‘r’ Use the ‘run’ command to start your program under GDB. You must d2150 3 a2152 2 Getting In and Out of GDB: Invocation.), or by using the ‘file’ or ‘exec-file’ command (*note Commands to Specify Files: Files.). d2155 5 a2159 4 supports processes, ‘run’ creates an inferior process and makes that process run your program. In some environments without processes, ‘run’ jumps to the start of your program. Other targets, like ‘remote’, are always running. If you get an error message like this one: d2164 1 a2164 1 then use ‘continue’ to run your program. You may need ‘load’ first d2169 4 a2172 4 information, which you must do _before_ starting your program. (You can change it after starting your program, but such changes only affect your program the next time you start it.) This information may be divided into four categories: d2176 1 a2176 1 ‘run’ command. If a shell is available on your target, the shell d2180 3 a2182 3 which shell is used with the ‘SHELL’ environment variable. If you do not define ‘SHELL’, GDB uses the default shell (‘/bin/sh’). You can disable use of any shell with the ‘set startup-with-shell’ d2187 3 a2189 3 can use the GDB commands ‘set environment’ and ‘unset environment’ to change parts of the environment that affect your program. *Note Your Program's Environment: Environment. d2192 2 a2193 2 You can set your program's working directory with the command ‘set cwd’. If you do not set any working directory with this command, d2202 1 a2202 1 in the ‘run’ command line, or you can use the ‘tty’ command to set d2211 5 a2215 5 When you issue the ‘run’ command, your program begins to execute immediately. *Note Stopping and Continuing: Stopping, for discussion of how to arrange for your program to stop. Once your program has stopped, you may call functions in your program, using the ‘print’ or ‘call’ commands. *Note Examining Data: Data. d2218 2 a2219 2 last time GDB read its symbols, GDB discards its symbol table, and reads it again. When it does this, GDB tries to retain your current d2222 1 a2222 1 ‘start’ d2224 5 a2228 5 With C or C++, the main procedure name is always ‘main’, but other languages such as Ada do not require a specific name for their main procedure. The debugger provides a convenient way to start the execution of the program and to stop at the beginning of the main procedure, depending on the language used. d2230 1 a2230 1 The ‘start’ command does the equivalent of setting a temporary d2232 1 a2232 1 the ‘run’ command. d2234 7 a2240 7 Some programs contain an “elaboration” phase where some startup code is executed before the main procedure is called. This depends on the languages used to write your program. In C++, for instance, constructors for static and global objects are executed before ‘main’ is called. It is therefore possible that the debugger stops before reaching the main procedure. However, the temporary breakpoint will remain to halt execution. d2243 2 a2244 2 ‘start’ command. These arguments will be given verbatim to the underlying ‘run’ command. Note that the same arguments will be d2246 1 a2246 1 ‘start’ or ‘run’. d2249 1 a2249 1 In these cases, using the ‘start’ command would stop the execution d2251 3 a2253 3 completed the elaboration phase. Under these circumstances, either insert breakpoints in your elaboration code before running your program or use the ‘starti’ command. d2255 2 a2256 2 ‘starti’ The ‘starti’ command does the equivalent of setting a temporary d2258 2 a2259 2 then invoking the ‘run’ command. For programs containing an elaboration phase, the ‘starti’ command will stop execution at the d2262 9 a2270 9 ‘set exec-wrapper WRAPPER’ ‘show exec-wrapper’ ‘unset exec-wrapper’ When ‘exec-wrapper’ is set, the specified wrapper is used to launch programs for debugging. GDB starts your program with a shell command of the form ‘exec WRAPPER PROGRAM’. Quoting is added to PROGRAM and its arguments, but not to WRAPPER, so you should add quotes if appropriate for your shell. The wrapper runs until it executes your program, and then GDB takes control. d2272 1 a2272 1 You can use any program that eventually calls ‘execve’ with its d2274 2 a2275 2 e.g. ‘env’ and ‘nohup’. Any Unix shell script ending with ‘exec "$@@"’ will also work. d2277 1 a2277 1 For example, you can use ‘env’ to pass an environment variable to d2287 4 a2290 4 ‘set startup-with-shell’ ‘set startup-with-shell on’ ‘set startup-with-shell off’ ‘show startup-with-shell’ d2292 6 a2297 6 target, GDB) uses it to start your program. Arguments of the ‘run’ command are passed to the shell, which does variable substitution, expands wildcard characters and performs redirection of I/O. In some circumstances, it may be useful to disable such use of a shell, for example, when debugging the shell itself or diagnosing startup failures such as: d2304 1 a2304 1 ‘exec-wrapper’ crashed, not your program. Most often, this is d2306 2 a2307 2 initialization file--such as ‘.cshrc’ for C-shell, $‘.zshenv’ for the Z shell, or the file specified in the ‘BASH_ENV’ environment d2310 4 a2313 5 ‘set auto-connect-native-target’ ‘set auto-connect-native-target on’ ‘set auto-connect-native-target off’ ‘show auto-connect-native-target’ d2315 1 a2315 1 yet (e.g., with ‘target remote’), the ‘run’ command starts your d2319 1 a2319 1 with the ‘set auto-connect-native-target off’ command. d2321 2 a2322 2 If ‘on’, which is the default, and if the current inferior is not connected to a target already, the ‘run’ command automatically d2325 2 a2326 2 If ‘off’, and if the current inferior is not connected to a target already, the ‘run’ command fails with an error: d2332 1 a2332 1 always uses it with the ‘run’ command. d2335 1 a2335 1 the ‘target native’ command. For example, d2345 1 a2345 1 In case you connected explicitly to the ‘native’ target, GDB d2347 1 a2347 1 ‘run’ command. Use the ‘disconnect’ command to disconnect. d2350 2 a2351 2 ‘auto-connect-native-target’ setting: ‘attach’, ‘info proc’, ‘info os’. d2353 2 a2354 2 ‘set disable-randomization’ ‘set disable-randomization on’ d2366 1 a2366 1 ‘set disable-randomization off’ d2372 1 a2372 1 stand-alone programs. Use ‘set disable-randomization off’ to try d2379 2 a2380 2 location makes it impossible to inject jumps misusing a code at its expected addresses. d2383 2 a2384 2 advantage but it makes addresses in these libraries predictable for privileged processes by having just unprivileged access at the d2392 6 a2397 6 Position independent executables (PIE) contain position independent code similar to the shared libraries and therefore such executables get loaded at a randomly chosen address upon startup. PIE executables always load even already prelinked shared libraries at a random address. You can build such executable using ‘gcc -fPIE -pie’. d2402 1 a2402 1 ‘show disable-randomization’ d2406 1 d2414 1 a2414 1 ‘run’ command. They are passed to a shell, which expands wildcard d2416 3 a2418 3 Your ‘SHELL’ environment variable (if it exists) specifies what shell GDB uses. If you do not define ‘SHELL’, GDB uses the default shell (‘/bin/sh’ on Unix). d2421 13 a2433 13 which emulates I/O redirection via the appropriate system calls, and the wildcard characters are expanded by the startup code of the program, not by the shell. ‘run’ with no arguments uses the same arguments used by the previous ‘run’, or those set by the ‘set args’ command. ‘set args’ Specify the arguments to be used the next time your program is run. If ‘set args’ has no arguments, ‘run’ executes your program with no arguments. Once you have run your program with arguments, using ‘set args’ before the next ‘run’ is the only way to run it again without arguments. d2435 1 a2435 1 ‘show args’ d2444 7 a2450 7 The “environment” consists of a set of environment variables and their values. Environment variables conventionally record such things as your user name, your home directory, your terminal type, and your search path for programs to run. Usually you set up environment variables with the shell and they are inherited by all the other programs you run. When debugging, it can be useful to try running your program with a modified environment without having to start GDB over again. d2452 2 a2453 2 ‘path DIRECTORY’ Add DIRECTORY to the front of the ‘PATH’ environment variable (the d2455 1 a2455 1 The value of ‘PATH’ used by GDB does not change. You may specify d2457 1 a2457 1 system-dependent separator character (‘:’ on Unix, ‘;’ on MS-DOS d2461 1 a2461 1 You can use the string ‘$cwd’ to refer to whatever is the current d2463 2 a2464 2 ‘.’ instead, it refers to the directory where you executed the ‘path’ command. GDB replaces ‘.’ in the DIRECTORY argument (with d2467 2 a2468 2 ‘show paths’ Display the list of search paths for executables (the ‘PATH’ d2471 5 a2475 5 ‘show environment [VARNAME]’ Print the value of environment variable VARNAME to be given to your program when it starts. If you do not supply VARNAME, print the names and values of all environment variables to be given to your program. You can abbreviate ‘environment’ as ‘env’. d2477 1 a2477 1 ‘set environment VARNAME [=VALUE]’ d2489 2 a2490 2 tells the debugged program, when subsequently run, that its user is named ‘foo’. (The spaces around ‘=’ are used for clarity here; d2493 4 a2496 4 Note that on Unix systems, GDB runs your program via a shell, which also inherits the environment set with ‘set environment’. If necessary, you can avoid that by using the ‘env’ program as a wrapper instead of using ‘set environment’. *Note set d2499 3 a2501 3 Environment variables that are set by the user are also transmitted to ‘gdbserver’ to be used when starting the remote inferior. *note QEnvironmentHexEncoded::. d2503 1 a2503 1 ‘unset environment VARNAME’ d2505 3 a2507 3 program. This is different from ‘set env VARNAME =’; ‘unset environment’ removes the variable from the environment, rather than assigning it an empty value. d2510 1 a2510 1 ‘gdbserver’ when starting the remote inferior. *note d2514 5 a2518 5 indicated by your ‘SHELL’ environment variable if it exists (or ‘/bin/sh’ if not). If your ‘SHELL’ variable names a shell that runs an initialization file when started non-interactively--such as ‘.cshrc’ for C-shell, $‘.zshenv’ for the Z shell, or the file specified in the ‘BASH_ENV’ environment variable for BASH--any variables you set in that d2520 2 a2521 2 variables to files that are only run when you sign on, such as ‘.login’ or ‘.profile’. d2529 6 a2534 6 Each time you start your program with ‘run’, the inferior will be initialized with the current working directory specified by the ‘set cwd’ command. If no directory has been specified by this command, then the inferior will inherit GDB's current working directory as its working directory if native debugging, or it will inherit the remote server's current working directory if remote debugging. d2536 1 a2536 1 ‘set cwd [DIRECTORY]’ d2538 3 a2540 3 ‘glob’-expanded in order to resolve tildes (‘~’). If no argument has been specified, the command clears the setting and resets it to an empty state. This setting has no effect on GDB's working d2542 4 a2545 4 inferior. The ‘~’ in DIRECTORY is a short for the “home directory”, usually pointed to by the ‘HOME’ environment variable. On MS-Windows, if ‘HOME’ is not defined, GDB uses the concatenation of ‘HOMEDRIVE’ and ‘HOMEPATH’ as fallback. d2548 1 a2548 1 ‘cd’ command. *Note cd command::. d2550 1 a2550 1 ‘show cwd’ d2552 1 a2552 1 specified by ‘set cwd’, then the default inferior's working d2555 1 a2555 1 ‘cd [DIRECTORY]’ d2557 1 a2557 1 DIRECTORY uses ‘'~'’. d2559 3 a2561 3 The GDB working directory serves as a default for the commands that specify files for GDB to operate on. *Note Commands to Specify Files: Files. *Note set cwd command::. d2563 1 a2563 1 ‘pwd’ d2568 3 a2570 3 during its run). If you work on a system where GDB supports the ‘info proc’ command (*note Process Information::), you can use the ‘info proc’ command to find out the current working directory of the debuggee. d2584 1 a2584 1 ‘info terminal’ d2589 1 a2589 1 redirection with the ‘run’ command. For example, d2593 1 a2593 1 starts your program, diverting its output to the file ‘outfile’. d2596 2 a2597 2 is with the ‘tty’ command. This command accepts a file name as argument, and causes this file to be the default for future ‘run’ d2599 1 a2599 1 process, for future ‘run’ commands. For example, d2603 3 a2605 3 directs that processes started with subsequent ‘run’ commands default to do input and output on the terminal ‘/dev/ttyb’ and have that as their controlling terminal. d2607 2 a2608 2 An explicit redirection in ‘run’ overrides the ‘tty’ command's effect on the input/output device, but not its effect on the controlling d2611 1 a2611 1 When you use the ‘tty’ command or redirect input in the ‘run’ d2613 2 a2614 2 GDB still comes from your terminal. ‘tty’ is an alias for ‘set inferior-tty’. d2616 1 a2616 1 You can use the ‘show inferior-tty’ command to tell GDB to display d2620 1 a2620 1 ‘set inferior-tty [ TTY ]’ d2625 1 a2625 1 ‘show inferior-tty’ d2634 1 a2634 1 ‘attach PROCESS-ID’ d2636 4 a2639 4 outside GDB. (‘info files’ shows your active targets.) The command takes as argument a process ID. The usual way to find out the PROCESS-ID of a Unix process is with the ‘ps’ utility, or with the ‘jobs -l’ shell command. d2641 1 a2641 1 ‘attach’ does not repeat if you press a second time after d2644 4 a2647 4 To use ‘attach’, your program must be running in an environment which supports processes; for example, ‘attach’ does not work for programs on bare-board targets that lack an operating system. You must also have permission to send the process a signal. d2649 1 a2649 1 When you use ‘attach’, the debugger finds the program running in the d2653 1 a2653 1 ‘file’ command to load the program. *Note Commands to Specify Files: d2658 1 a2658 1 by GDB, the option ‘exec-file-mismatch’ specifies how to handle the d2662 1 a2662 2 ‘set exec-file-mismatch ‘ask|warn|off’’ d2665 8 a2672 5 If ‘ask’, the default, display a warning and ask the user whether to load the process executable file; if ‘warn’, just display a warning; if ‘off’, don't attempt to detect a mismatch. If the user confirms loading the process executable file, then its symbols will be loaded as well. a2673 2 ‘show exec-file-mismatch’ Show the current value of ‘exec-file-mismatch’. d2678 1 a2678 1 processes with ‘run’. You can insert breakpoints; you can step and d2680 2 a2681 2 continue running, you may use the ‘continue’ command after attaching GDB to the process. d2683 1 a2683 1 ‘detach’ d2685 5 a2689 5 the ‘detach’ command to release it from GDB control. Detaching the process continues its execution. After the ‘detach’ command, that process and GDB become completely independent once more, and you are ready to ‘attach’ another process or start one with ‘run’. ‘detach’ does not repeat if you press again after executing d2693 1 a2693 1 process. If you use the ‘run’ command, you kill that process. By d2696 1 a2696 1 ‘set confirm’ command (*note Optional Warnings and Messages: d2705 1 a2705 1 ‘kill’ d2713 3 a2715 3 while you have breakpoints set on it inside GDB. You can use the ‘kill’ command in this situation to permit running your program outside the debugger. d2717 2 a2718 2 The ‘kill’ command is also useful if you wish to recompile and relink your program, since on many systems it is impossible to modify an d2720 3 a2722 3 you next type ‘run’, GDB notices that the file has changed, and reads the symbol table again (while trying to preserve your current breakpoint settings). d2740 1 a2740 1 called an “inferior”. An inferior typically corresponds to a process, d2749 7 a2755 7 The commands ‘info inferiors’ and ‘info connections’, which will be introduced below, accept a space-separated “ID list” as their argument specifying one or more elements on which to operate. A list element can be either a single non-negative number, like ‘5’, or an ascending range of such numbers, like ‘5-7’. A list can consist of any combination of such elements, even duplicates or overlapping ranges are valid. E.g. ‘1 4-6 5 4-4’ or ‘1 2 4-7’. d2757 1 a2757 1 To find out what inferiors exist at any moment, use ‘info inferiors’: d2759 1 a2759 1 ‘info inferiors’ d2776 2 a2777 1 An asterisk ‘*’ preceding the GDB inferior number indicates the d2787 1 a2787 1 To get information about the current inferior, use ‘inferior’: d2789 1 a2789 1 ‘inferior’ d2798 1 a2798 1 ‘info connections’: d2800 5 a2804 5 ‘info connections’ Print a list of all open target connections currently being managed by GDB. By default all connections are printed, but the ID list ID... can be used to limit the display to just the requested connections. d2814 2 a2815 1 An asterisk ‘*’ preceding the connection number indicates the d2826 1 a2826 1 To switch focus between inferiors, use the ‘inferior’ command: d2828 1 a2828 1 ‘inferior INFNO’ d2830 2 a2831 2 INFNO is the inferior number assigned by GDB, as shown in the first field of the ‘info inferiors’ display. d2833 5 a2837 5 The debugger convenience variable ‘$_inferior’ contains the number of the current inferior. You may find this useful in writing breakpoint conditional expressions, command scripts, and so forth. *Note Convenience Variables: Convenience Vars, for general information on convenience variables. d2840 1 a2840 1 ‘add-inferior’ and ‘clone-inferior’ commands. On some systems GDB can d2842 2 a2843 2 ‘fork’ and ‘exec’. To remove inferiors from the debugging session use the ‘remove-inferiors’ command. d2845 1 a2845 1 ‘add-inferior [ -copies N ] [ -exec EXECUTABLE ] [-no-connection ]’ d2847 4 a2850 4 defaults to 1. If no executable is specified, the inferiors begins empty, with no program. You can still assign or change the program assigned to the inferior at any time by using the ‘file’ command with the executable name as its argument. d2854 6 a2859 6 inferior was connected to ‘gdbserver’ with ‘target remote’, then the new inferior will be connected to the same ‘gdbserver’ instance. The ‘-no-connection’ option starts the new inferior with no connection yet. You can then for example use the ‘target remote’ command to connect to some other ‘gdbserver’ instance, use ‘run’ to spawn a local program, etc. d2861 1 a2861 1 ‘clone-inferior [ -copies N ] [ INFNO ]’ d2867 1 a2867 1 variables using the ‘set environment’ and ‘unset environment’ d2884 1 a2884 1 ‘remove-inferiors INFNO...’ d2887 2 a2888 1 use the ‘kill’ or ‘detach’ command first. d2892 2 a2893 2 ‘detach inferior’ command (allowing it to run independently), or kill it using the ‘kill inferiors’ command: d2895 1 a2895 1 ‘detach inferior INFNO...’ d2898 8 a2905 2 the list of inferiors shown by ‘info inferiors’, but its Description will show ‘’. d2907 12 a2918 18 ‘kill inferiors INFNO...’ Kill the inferior or inferiors identified by GDB inferior number(s) INFNO.... Note that the inferior's entry still stays on the list of inferiors shown by ‘info inferiors’, but its Description will show ‘’. After the successful completion of a command such as ‘detach’, ‘detach inferiors’, ‘kill’ or ‘kill inferiors’, or after a normal process exit, the inferior is still valid and listed with ‘info inferiors’, ready to be restarted. To be notified when inferiors are started or exit under GDB's control use ‘set print inferior-events’: ‘set print inferior-events’ ‘set print inferior-events on’ ‘set print inferior-events off’ The ‘set print inferior-events’ command allows you to enable or d2923 1 a2923 1 ‘show print inferior-events’ d2928 2 a2929 2 single program: e.g., ‘print myglobal’ will simply display the value of ‘myglobal’ in the current inferior. d2931 4 a2934 4 Occasionally, when debugging GDB itself, it may be useful to get more info about the relationship of inferiors, programs, address spaces in a debug session. You can do that with the ‘maint info program-spaces’ command. d2936 1 a2936 1 ‘maint info program-spaces’ d2943 2 a2944 2 2. the name of the executable loaded into the program space, with e.g., the ‘file’ command. d2947 1 a2947 1 e.g., the ‘core-file’ command. d2949 2 a2950 1 An asterisk ‘*’ preceding the GDB program space number indicates d2963 2 a2964 2 Here we can see that no inferior is running the program ‘hello’, while ‘process 21561’ is running the program ‘goodbye’. On some d2967 1 a2967 1 both the parent and child processes of a ‘vfork’ call. For d2976 1 a2976 1 program space as a result of inferior 1 having executed a ‘vfork’ d2992 2 a2993 2 ‘break LOCSPEC inferior INFERIOR-ID’ ‘break LOCSPEC inferior INFERIOR-ID if ...’ d2997 1 a2997 1 Use the qualifier ‘inferior INFERIOR-ID’ with a breakpoint command d2999 3 a3001 3 inferior reaches this breakpoint. The INFERIOR-ID specifier is one of the inferior identifiers assigned by GDB, shown in the first column of the ‘info inferiors’ output. d3003 1 a3003 1 If you do not specify ‘inferior INFERIOR-ID’ when you set a d3007 2 a3008 2 You can use the ‘inferior’ qualifier on conditional breakpoints as well; in this case, place ‘inferior INFERIOR-ID’ before or after d3021 1 a3021 1 Tasks::); using more than one of the ‘inferior’, ‘thread’, or ‘task’ d3031 3 a3033 3 program may have more than one “thread” of execution. The precise semantics of threads differ from one operating system to another, but in general the threads of a single program are akin to multiple d3041 7 a3047 4 • automatic notification of new threads • ‘thread THREAD-ID’, a command to switch among threads • ‘info threads’, a command to inquire about existing threads • ‘thread apply [THREAD-ID-LIST | all] ARGS’, a command to apply a d3049 4 a3052 2 • thread-specific breakpoints • ‘set print thread-events’, which controls printing of messages on d3054 3 a3056 2 • ‘set libthread-db-search-path PATH’, which lets the user specify which ‘libthread_db’ to use if the default choice isn't compatible d3062 1 a3062 1 “current thread”. Debugging commands show program information from the d3066 4 a3069 4 target system's identification for the thread with a message in the form ‘[New SYSTAG]’, where SYSTAG is a thread identifier whose form varies depending on the particular system. For example, on GNU/Linux, you might see d3074 1 a3074 1 SYSTAG is simply something like ‘process 368’, with no further d3077 4 a3080 4 For debugging purposes, GDB associates its own thread number --always a single integer--with each thread of an inferior. This number is unique between all threads of an inferior, but not unique between threads of different inferiors. d3083 1 a3083 1 INFERIOR-NUM.THREAD-NUM syntax, also known as “qualified thread ID”, d3085 1 a3085 1 thread number of the given inferior. For example, thread ‘2.3’ refers d3087 1 a3087 1 ‘thread 3’), then GDB infers you're referring to a thread of the current d3091 3 a3093 3 INFERIOR-NUM part of thread IDs, even though you can always use the full INFERIOR-NUM.THREAD-NUM form to refer to threads of inferior 1, the initial inferior. d3095 1 a3095 1 Some commands accept a space-separated “thread ID list” as argument. d3098 3 a3100 3 1. A thread ID as shown in the first field of the ‘info threads’ display, with or without an inferior qualifier. E.g., ‘2.1’ or ‘1’. d3103 2 a3104 2 qualifier, as in INF.THR1-THR2 or THR1-THR2. E.g., ‘1.2-4’ or ‘2-4’. d3107 1 a3107 1 without an inferior qualifier, as in INF.‘*’ (e.g., ‘1.*’) or ‘*’. d3112 1 d3114 1 a3114 1 thread with ID 7.1, the thread list ‘1 2-3 4.5 6.7-9 7.*’ includes d3117 1 a3117 1 qualified form, the same as ‘1.1 1.2 1.3 4.5 6.7 6.8 6.9 7.1’. d3120 1 a3120 1 a unique _global_ number, also known as “global thread ID”, a single d3125 3 a3127 3 From GDB's perspective, a process always has at least one thread. In other words, GDB assigns a thread number to the program's "main thread" even if the program is not multi-threaded. d3129 1 a3129 1 The debugger convenience variables ‘$_thread’ and ‘$_gthread’ d3133 1 a3133 1 forth. The convenience variable ‘$_inferior_thread_count’ contains the d3140 2 a3141 2 ‘$_inferior_thread_count’ could return a different value each time it is evaluated. d3153 1 a3153 2 ‘info threads [-gid] [THREAD-ID-LIST]’ d3163 2 a3164 2 2. the global thread number assigned by GDB, if the ‘-gid’ option was specified d3169 1 a3169 1 named by the user (see ‘thread name’, below), or, in some d3174 1 a3174 1 An asterisk ‘*’ to the left of the GDB thread number indicates the d3186 2 a3187 2 If you're debugging multiple inferiors, GDB displays thread IDs using the qualified INFERIOR-NUM.THREAD-NUM format. Otherwise, only d3190 1 a3190 1 If you specify the ‘-gid’ option, GDB displays a column indicating d3203 1 a3203 1 ‘maint info sol-threads’ d3206 1 a3206 1 ‘thread THREAD-ID’ d3209 2 a3210 2 ‘info threads’ display, with or without an inferior qualifier (e.g., ‘2.1’ or ‘1’). d3220 2 a3221 2 As with the ‘[New ...]’ message, the form of the text after ‘Switching to’ depends on your system's conventions for identifying d3224 8 a3231 8 ‘thread apply [THREAD-ID-LIST | all [-ascending]] [FLAG]... COMMAND’ The ‘thread apply’ command allows you to apply the named COMMAND to one or more threads. Specify the threads that you want affected using the thread ID list syntax (*note thread ID lists::), or specify ‘all’ to apply to all threads. To apply a command to all threads in descending order, type ‘thread apply all COMMAND’. To apply a command to all threads in ascending order, type ‘thread apply all -ascending COMMAND’. d3235 3 a3237 3 with a ‘-’ directly followed by one letter in ‘qcs’. If several flags are provided, they must be given individually, such as ‘-c -q’. d3241 2 a3242 2 COMMAND will abort ‘thread apply’. The following flags can be used to fine-tune this behavior: d3244 8 a3251 7 ‘-c’ The flag ‘-c’, which stands for ‘continue’, causes any errors in COMMAND to be displayed, and the execution of ‘thread apply’ then continues. ‘-s’ The flag ‘-s’, which stands for ‘silent’, causes any errors or empty output produced by a COMMAND to be silently ignored. d3254 3 a3256 2 ‘-q’ The flag ‘-q’ (‘quiet’) disables printing the thread d3259 1 a3259 1 Flags ‘-c’ and ‘-s’ cannot be used together. d3261 2 a3262 2 ‘taas [OPTION]... COMMAND’ Shortcut for ‘thread apply all -s [OPTION]... COMMAND’. Applies d3265 2 a3266 2 The ‘taas’ command accepts the same options as the ‘thread apply all’ command. *Note thread apply all::. d3268 9 a3276 9 ‘tfaas [OPTION]... COMMAND’ Shortcut for ‘thread apply all -s -- frame apply all -s [OPTION]... COMMAND’. Applies COMMAND on all frames of all threads, ignoring errors and empty output. Note that the flag ‘-s’ is specified twice: The first ‘-s’ ensures that ‘thread apply’ only shows the thread information of the threads for which ‘frame apply’ produces some output. The second ‘-s’ is needed to ensure that ‘frame apply’ shows the frame information of a frame only if the COMMAND successfully produced some output. d3279 2 a3280 2 argument without knowing the thread or frame where this variable or argument is, using: d3283 1 a3283 1 The ‘tfaas’ command accepts the same options as the ‘frame apply’ d3286 1 a3286 1 ‘thread name [NAME]’ d3289 1 a3289 1 name appears in the ‘info threads’ display. d3292 2 a3293 2 name of the thread as given by the OS. On these systems, a name specified with ‘thread name’ will override the system-give name, d3297 1 a3297 1 ‘thread find [REGEXP]’ d3301 1 a3301 1 As well as being the complement to the ‘thread name’ command, this d3311 4 a3314 4 ‘set print thread-events’ ‘set print thread-events on’ ‘set print thread-events off’ The ‘set print thread-events’ command allows you to enable or d3321 1 a3321 1 ‘show print thread-events’ d3332 1 a3332 1 ‘set libthread-db-search-path [PATH]’ d3334 5 a3338 4 directories GDB will use to search for ‘libthread_db’. If you omit PATH, ‘libthread-db-search-path’ will be reset to its default value (‘$sdir:$pdir’ on GNU/Linux and Solaris systems). Internally, the default value comes from the ‘LIBTHREAD_DB_SEARCH_PATH’ macro. d3341 5 a3345 5 ‘libthread_db’ library to obtain information about threads in the inferior process. GDB will use ‘libthread-db-search-path’ to find ‘libthread_db’. GDB also consults first if inferior specific thread debugging library loading is enabled by ‘set auto-load libthread-db’ (*note libthread_db.so.1 file::). d3347 1 a3347 1 A special entry ‘$sdir’ for ‘libthread-db-search-path’ refers to d3349 2 a3350 2 loading shared libraries. The ‘$sdir’ entry is the only kind not needing to be enabled by ‘set auto-load libthread-db’ (*note d3353 2 a3354 2 A special entry ‘$pdir’ for ‘libthread-db-search-path’ refers to the directory from which ‘libpthread’ was loaded in the inferior d3357 1 a3357 1 For any ‘libthread_db’ library GDB finds in above directories, GDB d3360 3 a3362 3 mismatch between ‘libthread_db’ and ‘libpthread’), GDB will unload ‘libthread_db’, and continue with the next directory. If none of ‘libthread_db’ libraries initialize successfully, GDB will issue a d3365 2 a3366 2 Setting ‘libthread-db-search-path’ is currently implemented only on some platforms. d3368 1 a3368 1 ‘show libthread-db-search-path’ d3371 8 a3378 8 ‘set debug libthread-db’ ‘show debug libthread-db’ Turns on or off display of ‘libthread_db’-related events. Use ‘1’ to enable, ‘0’ to disable. ‘set debug threads [on|off]’ ‘show debug threads’ When ‘on’ GDB will print additional messages when threads are d3387 6 a3392 6 On most systems, GDB has no special support for debugging programs which create additional processes using the ‘fork’ function. When a program forks, GDB will continue to debug the parent process and the child process will run unimpeded. If you have set a breakpoint in any code which the child then executes, the child will get a ‘SIGTRAP’ signal which (unless it catches the signal) will cause it to terminate. d3395 1 a3395 1 which isn't too painful. Put a call to ‘sleep’ in the code which the d3399 2 a3400 2 child. While the child is sleeping, use the ‘ps’ program to get its process ID. Then tell GDB (a new invocation of GDB if you are also d3402 2 a3403 2 Attach::). From that point on you can debug the child process just like any other process which you attached to. d3406 1 a3406 1 create additional processes using the ‘fork’ or ‘vfork’ functions. On d3411 2 a3412 2 connected to ‘gdbserver’ in either ‘target remote’ mode or ‘target extended-remote’ mode. d3418 1 a3418 1 process, use the command ‘set follow-fork-mode’. d3420 3 a3422 3 ‘set follow-fork-mode MODE’ Set the debugger response to a program call of ‘fork’ or ‘vfork’. A call to ‘fork’ or ‘vfork’ creates a new process. The MODE d3425 1 a3425 1 ‘parent’ d3429 1 a3429 1 ‘child’ d3433 3 a3435 2 ‘show follow-fork-mode’ Display the current debugger response to a ‘fork’ or ‘vfork’ call. d3438 1 a3438 1 use the command ‘set detach-on-fork’. d3440 1 a3440 1 ‘set detach-on-fork MODE’ d3444 1 a3444 1 ‘on’ d3446 1 a3446 1 of ‘follow-fork-mode’) will be detached and allowed to run d3449 1 a3449 1 ‘off’ d3452 1 a3452 1 ‘follow-fork-mode’) is debugged as usual, while the other is d3455 2 a3456 1 ‘show detach-on-fork’ d3459 1 a3459 1 If you choose to set ‘detach-on-fork’ mode off, then GDB will retain d3462 2 a3463 2 ‘info inferiors’ command, and switch from one fork to another by using the ‘inferior’ command (*note Debugging Multiple Inferiors Connections d3467 2 a3468 2 from it by using the ‘detach inferiors’ command (allowing it to run independently), or kill it using the ‘kill inferiors’ command. *Note d3472 4 a3475 4 If you ask to debug a child process and a ‘vfork’ is followed by an ‘exec’, GDB executes the new target up to the first breakpoint in the new target. If you have a breakpoint set on ‘main’ in your original program, the breakpoint will also be set on the child process's ‘main’. d3477 2 a3478 2 On some systems, when a child process is spawned by ‘vfork’, you cannot debug the child or parent until an ‘exec’ call completes. d3480 2 a3481 2 If you issue a ‘run’ command to GDB after an ‘exec’ call executes, the new target restarts. To restart the parent process, use the ‘file’ d3483 1 a3483 1 after an ‘exec’ call executes, GDB discards the symbols of the previous d3485 1 a3485 3 ‘set follow-exec-mode’ command. ‘set follow-exec-mode MODE’ d3487 2 a3488 1 Set debugger response to a program call of ‘exec’. An ‘exec’ call d3491 1 a3491 1 ‘follow-exec-mode’ can be: d3493 4 a3496 4 ‘new’ GDB creates a new inferior and rebinds the process to this new inferior. The program the process was running before the ‘exec’ call can be restarted afterwards by restarting the d3513 1 a3513 1 ‘same’ d3516 3 a3518 3 the inferior. Restarting the inferior after the ‘exec’ call, with e.g., the ‘run’ command, restarts the executable the process was running after the ‘exec’ call. This is the a3532 2 ‘follow-exec-mode’ is supported in native mode and ‘target extended-remote’ mode. d3534 5 a3538 2 You can use the ‘catch’ command to make GDB stop whenever a ‘fork’, ‘vfork’, or ‘exec’ call is made. *Note Setting Catchpoints: Set d3547 2 a3548 2 On certain operating systems(1), GDB is able to save a “snapshot” of a program's state, called a “checkpoint”, and come back to it later. d3551 4 a3554 4 happened in the program since the ‘checkpoint’ was saved. This includes changes in memory, registers, and even (within some limits) system state. Effectively, it is like going back in time to the moment when the checkpoint was saved. d3565 1 a3565 1 To use the ‘checkpoint’/‘restart’ method of debugging: d3567 1 a3567 1 ‘checkpoint’ d3569 2 a3570 2 The ‘checkpoint’ command takes no arguments, but each checkpoint is assigned a small integer id, similar to a breakpoint id. d3572 1 a3572 1 ‘info checkpoints’ d3577 3 a3579 4 ‘Checkpoint ID’ ‘Process ID’ ‘Code Address’ ‘Source line, or label’ d3581 5 a3585 1 ‘restart CHECKPOINT-ID’ d3587 9 a3595 9 CHECKPOINT-ID. All program variables, registers, stack frames etc. will be returned to the values that they had when the checkpoint was saved. In essence, gdb will "wind back the clock" to the point in time when the checkpoint was saved. Note that breakpoints, GDB variables, command history etc. are not affected by restoring a checkpoint. In general, a checkpoint only restores things that reside in the program being debugged, not in the debugger. d3597 1 a3597 1 ‘delete checkpoint CHECKPOINT-ID’ d3600 1 d3610 3 a3612 3 external device) cannot be "snatched back", and characters received from eg. a serial device can be removed from internal program buffers, but they cannot be "pushed back" into the serial pipeline, ready to be d3623 4 a3626 3 Each checkpoint will have a unique process id (or PID), and each will be different from the program's original PID. If your program has saved a local copy of its process id, this could potentially pose a problem. d3640 2 a3641 2 can avoid the effects of address randomization and your symbols will all stay in the same place. d3657 3 a3659 3 Inside GDB, your program may stop for any of several reasons, such as a signal, a breakpoint, or reaching a new line after a GDB command such as ‘step’. You may then examine and change variables, set new d3665 1 a3665 1 ‘info program’ d3685 1 a3685 1 A “breakpoint” makes your program stop whenever a certain point in the d3688 1 a3688 1 breakpoints with the ‘break’ command and its variants (*note Setting d3696 1 a3696 1 A “watchpoint” is a special breakpoint that stops your program when d3699 2 a3700 2 by operators, such as ‘a + b’. This is sometimes called “data breakpoints”. You must use a different command to set watchpoints d3709 1 a3709 1 A “catchpoint” is another special breakpoint that stops your program d3715 1 a3715 1 ‘handle’ command; see *note Signals: Signals.) d3721 1 a3721 1 want to change. Each breakpoint may be “enabled” or “disabled”; if d3726 1 a3726 1 number, like ‘5’, or a range of such numbers, like ‘5-7’. When a d3742 2 a3743 2 * Error in Breakpoints:: "Cannot insert breakpoints" * Breakpoint-related Warnings:: "Breakpoint address adjusted..." d3751 2 a3752 2 Breakpoints are set with the ‘break’ command (abbreviated ‘b’). The debugger convenience variable ‘$bpnum’ records the number of the d3770 1 a3770 1 ‘$_hit_bpnum’ and ‘$_hit_locno’ are respectively set to the number of d3781 2 a3782 2 Note that ‘$_hit_bpnum’ and ‘$bpnum’ are not equivalent: ‘$_hit_bpnum’ is set to the breakpoint number last hit, while ‘$bpnum’ d3786 1 a3786 1 ‘$_hit_locno’ is set to 1: d3795 1 a3795 1 The ‘$_hit_bpnum’ and ‘$_hit_locno’ variables can typically be used d3798 5 a3802 5 can disable completely the encountered breakpoint using ‘disable $_hit_bpnum’ or disable the specific encountered breakpoint location using ‘disable $_hit_bpnum.$_hit_locno’. If a breakpoint has only one location, ‘$_hit_locno’ is set to 1 and the commands ‘disable $_hit_bpnum’ and ‘disable $_hit_bpnum.$_hit_locno’ both disable the d3810 1 a3810 1 ‘break LOCSPEC’ d3830 4 a3833 4 ‘break’ When called without any arguments, ‘break’ sets a breakpoint at the next instruction to be executed in the selected stack frame (*note Examining the Stack: Stack.). In any selected frame but the d3835 6 a3840 5 to that frame. This is similar to the effect of a ‘finish’ command in the frame inside the selected frame--except that ‘finish’ does not leave an active breakpoint. If you use ‘break’ without an argument in the innermost frame, GDB stops the next time it reaches the current location; this may be useful inside loops. d3843 4 a3846 4 at least one instruction has been executed. If it did not do this, you would be unable to proceed past a breakpoint without first disabling the breakpoint. This rule applies whether or not the breakpoint already existed when your program stopped. d3848 1 a3848 1 ‘break ... if COND’ d3851 1 a3851 1 nonzero--that is, if COND evaluates as true. ‘...’ stands for one d3853 2 a3854 2 specifying where to break. *Note Break Conditions: Conditions, for more information on breakpoint conditions. d3869 3 a3871 2 Locations that are disabled because of the condition are denoted by an uppercase ‘N’ in the output of the ‘info breakpoints’ command: d3882 3 a3884 3 If the breakpoint condition COND is invalid in the context of _all_ the locations of the breakpoint, GDB refuses to define the breakpoint. For example, if variable ‘foo’ is an undefined d3890 1 a3890 1 ‘break ... -force-condition if COND’ d3894 2 a3895 2 cases, by using the ‘-force-condition’ keyword before ‘if’, GDB can be forced to define the breakpoint with the given condition d3909 2 a3910 2 above. However, if there exist locations at which the condition is valid, the ‘-force-condition’ keyword has no effect. d3912 1 a3912 1 ‘tbreak ARGS’ d3914 1 a3914 1 as for the ‘break’ command, and the breakpoint is set in the same d3919 1 a3919 1 ‘hbreak ARGS’ d3921 1 a3921 1 the ‘break’ command and the breakpoint is set in the same way, but d3927 11 a3937 10 targets. These targets will generate traps when a program accesses some data or instruction address that is assigned to the debug registers. However the hardware breakpoint registers can take a limited number of breakpoints. For example, on the DSU, only two data breakpoints can be set at a time, and GDB will reject this command if more than two are used. Delete or disable unused hardware breakpoints before setting new ones (*note Disabling Breakpoints: Disabling.). *Note Break Conditions: Conditions. For remote targets, you can restrict the number of hardware breakpoints GDB will use, see *note set remote hardware-breakpoint-limit::. d3939 1 a3939 1 ‘thbreak ARGS’ d3941 2 a3942 2 ARGS are the same as for the ‘hbreak’ command and the breakpoint is set in the same way. However, like the ‘tbreak’ command, the d3944 1 a3944 1 program stops there. Also, like the ‘hbreak’ command, the d3947 1 a3947 1 See also *note Break Conditions: Conditions. d3949 1 a3949 1 ‘rbreak REGEX’ d3953 3 a3955 3 breakpoints are set, they are treated just like the breakpoints set with the ‘break’ command. You can delete them, disable them, or make them conditional the same way as any other breakpoint. d3958 2 a3959 2 print the list of all breakpoints it sets according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language d3962 1 a3962 1 specified language (see *note Set Language Manually: Manually.). d3965 6 a3970 6 tools like ‘grep’. Note that this is different from the syntax used by shells, so for instance ‘foo*’ matches all functions that include an ‘fo’ followed by zero or more ‘o’s. There is an implicit ‘.*’ leading and trailing the regular expression you supply, so to match only functions that begin with ‘foo’, use ‘^foo’. d3972 1 a3972 1 When debugging C++ programs, ‘rbreak’ is useful for setting d3976 1 a3976 1 The ‘rbreak’ command can be used to set breakpoints in *all* the d3981 2 a3982 2 ‘rbreak FILE:REGEX’ If ‘rbreak’ is called with a filename qualification, it limits the d3992 2 a3993 2 ‘info breakpoints [LIST...]’ ‘info break [LIST...]’ d4000 3 a4002 2 _Breakpoint Numbers_ _Type_ d4004 2 a4005 1 _Disposition_ d4008 3 a4010 2 _Enabled or Disabled_ Enabled breakpoints are marked with ‘y’. ‘n’ marks d4012 2 a4013 1 _Address_ d4015 8 a4022 7 For a pending breakpoint whose address is not yet known, this field will contain ‘’. Such breakpoint won't fire until a shared library that has the symbol or line referred by breakpoint is loaded. See below for details. A breakpoint with several locations will have ‘’ in this field--see below for details. _What_ d4032 1 a4032 1 then the condition is evaluated by the target. The ‘info break’ d4043 4 a4046 4 ‘info break’ with a breakpoint number N as argument lists only that breakpoint. The convenience variable ‘$_’ and the default examining-address for the ‘x’ command are set to the address of the last breakpoint listed (*note Examining Memory: Memory.). d4048 1 a4048 1 ‘info break’ displays a count of the number of times the breakpoint d4050 1 a4050 1 ‘ignore’ command. You can ignore a large number of breakpoint d4052 2 a4053 2 breakpoint was hit, and then run again, ignoring one less than that number. This will get you quickly to the last hit of that d4056 3 a4058 2 For a breakpoints with an enable count (xref) greater than 1, ‘info break’ also displays that count. d4070 6 a4075 5 breakpoint table using several rows--one header row, followed by one row for each code location. The header row has ‘’ in the address column. Each code location row contains the actual address, source file, source line and function of its code location. The number column for a code location is of the form BREAKPOINT-NUMBER.LOCATION-NUMBER. d4088 2 a4089 2 passing BREAKPOINT-NUMBER.LOCATION-NUMBER as argument to the ‘enable’ and ‘disable’ commands. It's also possible to ‘enable’ and ‘disable’ a d4092 2 a4093 2 ‘BREAKPOINT-NUMBER.LOCATION-NUMBER1-LOCATION-NUMBER2’, in which case GDB acts on all the locations in the range (inclusive). Disabling or d4098 2 a4099 2 won't trigger a break, and are denoted by ‘y-’ in the ‘Enb’ column. For example: d4113 5 a4117 4 the beginning of your debugging session, when the library is not loaded, and when the symbols from the library are not available. When you try to set breakpoint, GDB will ask you if you want to set a so called “pending breakpoint”--breakpoint whose address is not yet resolved. d4120 5 a4124 5 GDB reevaluates all the breakpoints. When a newly loaded shared library contains the symbol or line referred to by some pending breakpoint, that breakpoint is resolved and becomes an ordinary breakpoint. When a library is unloaded, all breakpoints that refer to its symbols or source lines become pending again. d4128 2 a4129 2 newly loaded shared library has an instantiation of that template, a new location is added to the list of locations for the breakpoint. d4136 1 a4136 1 when the ‘break’ command cannot resolve the location spec to any code d4139 4 a4142 4 ‘set breakpoint pending auto’ This is the default behavior. When GDB cannot resolve the location spec, it queries you whether a pending breakpoint should be created. d4144 1 a4144 1 ‘set breakpoint pending on’ d4148 1 a4148 1 ‘set breakpoint pending off’ d4154 1 a4154 1 ‘show breakpoint pending’ d4157 1 a4157 1 The settings above only affect the ‘break’ command and its variants. d4162 5 a4166 5 software breakpoints should be used, depending on whether the breakpoint address is read-only or read-write. This applies to breakpoints set with the ‘break’ command as well as to internal breakpoints set by commands like ‘next’ and ‘finish’. For breakpoints set with ‘hbreak’, GDB will always use hardware breakpoints. d4170 1 a4170 1 ‘set breakpoint auto-hw on’ d4175 4 a4178 4 ‘set breakpoint auto-hw off’ This indicates GDB should not automatically select breakpoint type. If the target provides a memory map, GDB will warn when trying to set software breakpoint at a read-only address. d4181 8 a4188 8 the breakpoint address with a special instruction, which, when executed, given control to the debugger. By default, the program code is so modified only when the program is resumed. As soon as the program stops, GDB restores the original instructions. This behaviour guards against leaving breakpoints inserted in the target should gdb abrubptly disconnect. However, with slow remote targets, inserting and removing breakpoint can reduce the performance. This behavior can be controlled with the following commands:: d4190 1 a4190 1 ‘set breakpoint always-inserted off’ d4195 1 a4195 1 ‘set breakpoint always-inserted on’ d4199 2 a4200 2 A breakpoint is removed from the target only when breakpoint itself is deleted. d4211 1 a4211 1 ‘set breakpoint condition-evaluation host’ d4217 1 a4217 1 ‘set breakpoint condition-evaluation target’ d4219 11 a4229 11 target at the moment of their insertion. The target is responsible for evaluating the conditional expression and reporting breakpoint stop events back to GDB whenever the condition is true. Due to limitations of target-side evaluation, some conditions cannot be evaluated there, e.g., conditions that depend on local data that is only known to the host. Examples include conditional expressions involving convenience variables, complex types that cannot be handled by the agent expression parser and expressions that are too long to be sent over to the target, specially when the target is a remote system. In these cases, the conditions will be evaluated by GDB. d4231 1 a4231 1 ‘set breakpoint condition-evaluation auto’ d4240 5 a4244 5 purposes, such as proper handling of ‘longjmp’ (in C programs). These internal breakpoints are assigned negative numbers, starting with ‘-1’; ‘info breakpoints’ does not display them. You can see these breakpoints with the GDB maintenance command ‘maint info breakpoints’ (*note maint info breakpoints::). d4254 1 a4254 1 this may happen. (This is sometimes called a “data breakpoint”.) The d4258 1 a4258 1 • A reference to the value of a single variable. d4260 3 a4262 3 • An address cast to an appropriate data type. For example, ‘*(int *)0x12345678’ will watch a 4-byte region at the specified address (assuming an ‘int’ occupies 4 bytes). d4264 1 a4264 1 • An arbitrarily complex expression, such as ‘a*b + c/d’. The d4270 2 a4271 2 ‘*global_ptr’ before ‘global_ptr’ is initialized. GDB will stop when your program sets ‘global_ptr’ and the expression produces a valid d4273 2 a4274 2 a variable (e.g. if the memory pointed to by ‘*global_ptr’ becomes readable as the result of a ‘malloc’ call), GDB may not stop until the d4288 1 a4288 1 ‘watch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE] [task TASK-ID]’ d4296 5 a4300 5 If the command includes a ‘[thread THREAD-ID]’ argument, GDB breaks only when the thread identified by THREAD-ID changes the value of EXPR. If any other threads change the value of EXPR, GDB will not break. Note that watchpoints restricted to a single thread in this way only work with Hardware Watchpoints. d4302 1 a4302 1 Similarly, if the ‘task’ argument is given, then the watchpoint d4306 1 a4306 1 (see below). The ‘-location’ argument tells GDB to instead watch d4313 1 a4313 1 The ‘[mask MASKVALUE]’ argument allows creation of masked d4315 3 a4317 3 (e.g., PowerPC Embedded architecture, see *note PowerPC Embedded::.) A “masked watchpoint” specifies a mask in addition to an address to watch. The mask specifies that some bits of an d4323 1 a4323 1 ‘mask’ argument implies ‘-location’. Examples: d4328 1 a4328 1 ‘rwatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]’ d4332 1 a4332 1 ‘awatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]’ d4336 1 a4336 1 ‘info watchpoints [LIST...]’ d4338 1 a4338 1 ‘info break’ (*note Set Breaks::). d4341 3 a4343 3 to dereference it, as the address itself is just a constant number which will never change. GDB refuses to create a watchpoint that watches a never-changing value: d4350 1 a4350 1 GDB sets a “hardware watchpoint” if possible. Hardware watchpoints d4352 3 a4354 3 exact instruction where the change occurs. If GDB cannot set a hardware watchpoint, it sets a software watchpoint, which executes more slowly and reports the change in value at the next _statement_, not the d4357 2 a4358 2 You can force GDB to use only software watchpoints with the ‘set can-use-hw-watchpoints 0’ command. With this variable set to zero, GDB d4361 1 a4361 1 were set _before_ setting ‘can-use-hw-watchpoints’ to zero will still d4364 1 a4364 1 ‘set can-use-hw-watchpoints’ d4367 1 a4367 1 ‘show can-use-hw-watchpoints’ d4371 1 a4371 1 watchpoints GDB will use, see *note set remote d4374 1 a4374 1 When you issue the ‘watch’ command, GDB reports d4380 7 a4386 6 Currently, the ‘awatch’ and ‘rwatch’ commands can only set hardware watchpoints, because accesses to data that don't change the value of the watched expression cannot be detected without examining every instruction as it is being executed, and GDB does not do that currently. If GDB finds that it is unable to set a hardware breakpoint with the ‘awatch’ or ‘rwatch’ command, it will print a message like this: d4390 8 a4397 8 Sometimes, GDB cannot set a hardware watchpoint because the data type of the watched expression is wider than what a hardware watchpoint on the target machine can handle. For example, some systems can only watch regions that are up to 4 bytes wide; on such systems you cannot set hardware watchpoints for an expression that yields a double-precision floating-point number (which is typically 8 bytes wide). As a work-around, it might be possible to break the large region into a series of smaller ones and watch them with separate watchpoints. d4400 5 a4404 5 insert all of them when you resume the execution of your program. Since the precise number of active watchpoints is unknown until such time as the program is about to be resumed, GDB might not be able to warn you about this when you set the watchpoints, and the warning will be printed only when the program is resumed: d4415 3 a4417 3 If you call a function interactively using ‘print’ or ‘call’, any watchpoints you have set will be inactive until GDB reaches another kind of breakpoint or the call completes. d4426 1 a4426 1 doing that would be to set a code breakpoint at the entry to the ‘main’ d4434 4 a4437 4 can only watch the value of an expression _in a single thread_. If you are confident that the expression can only change due to the current thread's activity (and if you are also confident that no other thread can become current), then you can use software d4450 1 a4450 1 You can use “catchpoints” to cause the debugger to stop for certain d4452 1 a4452 1 shared library. Use the ‘catch’ command to set a catchpoint. d4454 1 a4454 1 ‘catch EVENT’ d4457 3 a4459 3 ‘throw [REGEXP]’ ‘rethrow [REGEXP]’ ‘catch [REGEXP]’ d4465 1 a4465 1 The convenience variable ‘$_exception’ is available at an d4469 2 a4470 2 There are currently some limitations to C++ exception handling in GDB: d4472 3 a4474 3 • The support for these commands is system-dependent. Currently, only systems using the ‘gnu-v3’ C++ ABI (*note ABI::) are supported. d4476 1 a4476 1 • The regular expression feature and the ‘$_exception’ d4478 1 a4478 1 probes in ‘libstdc++’. If these probes are not present, d4481 2 a4482 2 not they are available in your GCC also depends on how it was built. d4484 1 a4484 1 • The ‘$_exception’ convenience variable is only valid at d4488 4 a4491 4 • When an exception-related catchpoint is hit, GDB stops at a location in the system library which implements runtime exception support for C++, usually ‘libstdc++’. You can use ‘up’ (*note Selection::) to get to your code. d4493 1 a4493 1 • If you call a function interactively, GDB normally d4495 10 a4504 9 executing. If the call raises an exception, however, the call may bypass the mechanism that returns control to you and cause your program either to abort or to simply continue running until it hits a breakpoint, catches a signal that GDB is listening for, or exits. This is the case even if you set a catchpoint for the exception; catchpoints on exceptions are disabled within interactive calls. *Note Calling::, for information on controlling this with ‘set unwind-on-terminating-exception’. d4506 1 a4506 1 • You cannot raise an exception interactively. d4508 1 a4508 1 • You cannot install an exception handler interactively. d4510 1 a4510 1 ‘exception [NAME]’ d4512 2 a4513 2 specified at the end of the command (eg ‘catch exception Program_Error’), the debugger will stop only when this d4519 3 a4521 3 defined by the language, the fully qualified name must be used as the exception name. Otherwise, GDB will assume that it should stop on the pre-defined exception rather than the d4523 3 a4525 3 ‘Constraint_Error’ is defined in package ‘Pck’, then the command to use to catch such exceptions is ‘catch exception Pck.Constraint_Error’. d4527 1 a4527 1 The convenience variable ‘$_ada_exception’ holds the address d4531 1 a4531 1 ‘exception unhandled’ d4533 2 a4534 2 program. The convenience variable ‘$_ada_exception’ is set as for ‘catch exception’. d4536 1 a4536 1 ‘handlers [NAME]’ d4538 2 a4539 2 specified at the end of the command (eg ‘catch handlers Program_Error’), the debugger will stop only when this d4549 3 a4551 3 ‘Constraint_Error’ is defined in package ‘Pck’, then the command to use to catch such exceptions handling is ‘catch handlers Pck.Constraint_Error’. d4553 2 a4554 2 The convenience variable ‘$_ada_exception’ is set as for ‘catch exception’. d4556 1 a4556 1 ‘assert’ d4558 1 a4558 1 ‘$_ada_exception’ is _not_ set by this catchpoint. d4560 2 a4561 2 ‘exec’ A call to ‘exec’. d4563 3 a4565 3 ‘syscall’ ‘syscall [NAME | NUMBER | group:GROUPNAME | g:GROUPNAME] ...’ A call to or return from a system call, a.k.a. “syscall”. A d4567 5 a4571 5 service from the operating system (OS) or one of the OS system services. GDB can catch some or all of the syscalls issued by the debuggee, and show the related information for each syscall. If no argument is specified, calls to and returns from all system calls will be caught. d4574 3 a4576 3 underlying OS. Just what syscalls are valid depends on the OS. On GNU and Unix systems, you can find the full list of valid syscall names on ‘/usr/include/asm/unistd.h’. d4587 4 a4590 4 name into the corresponding numeric code, but using the number directly may be useful if GDB's database does not have the complete list of syscalls on your system (e.g., because GDB lags behind the OS upgrades). d4593 8 a4600 7 once using the ‘group:’ syntax (‘g:’ is a shorter equivalent). For instance, on some platforms GDB allows you to catch all network related syscalls, by passing the argument ‘group:network’ to ‘catch syscall’. Note that not all syscall groups are available in every system. You can use the command completion facilities (*note command completion: Completion.) to list the syscall groups available on your environment. d4669 3 a4671 3 this case, GDB prints a warning message saying that it was not able to find the syscall name, but the catchpoint will be set anyway. See the example below: d4678 1 a4678 1 If you configure GDB using the ‘--without-expat’ option, it d4683 2 a4684 2 accessing the syscall name database. In either case, you will see a warning like this: d4703 2 a4704 2 Again, in this case GDB would not be able to display syscall's names. d4706 2 a4707 2 ‘fork’ A call to ‘fork’. d4709 2 a4710 2 ‘vfork’ A call to ‘vfork’. d4712 2 a4713 2 ‘load [REGEXP]’ ‘unload [REGEXP]’ d4718 1 a4718 1 ‘signal [SIGNAL... | ‘all’]’ d4723 1 a4723 1 except ‘SIGTRAP’ and ‘SIGINT’. d4725 1 a4725 1 With the argument ‘all’, all signals, including those used by d4730 2 a4731 2 to ‘handle’ (*note Signals::). Only signals specified in this list will be caught. d4733 2 a4734 2 One reason that ‘catch signal’ can be more useful than ‘handle’ is that you can attach commands and conditions to the d4737 6 a4742 9 When a signal is caught by a catchpoint, the signal's ‘stop’ and ‘print’ settings, as specified by ‘handle’, are ignored. However, whether the signal is still delivered to the inferior depends on the ‘pass’ setting; this can be changed in the catchpoint's commands. ‘tcatch EVENT’ Set a catchpoint that is enabled only for one stop. The catchpoint is automatically deleted after the first time the event is caught. d4744 7 a4750 1 Use the ‘info break’ command to list the current catchpoints. d4760 1 a4760 1 to stop there. This is called “deleting” the breakpoint. A breakpoint d4763 2 a4764 2 With the ‘clear’ command you can delete breakpoints according to where they are in your program. With the ‘delete’ command you can d4773 1 a4773 1 ‘clear’ d4779 1 a4779 1 ‘clear LOCSPEC’ d4781 8 a4788 8 LOCSPEC. *Note Location Specifications::, for the various forms of LOCSPEC. Which code locations correspond to LOCSPEC depends on the form used in the location specification LOCSPEC: ‘LINENUM’ ‘FILENAME:LINENUM’ ‘-line LINENUM’ ‘-source FILENAME -line LINENUM’ d4795 1 a4795 1 ‘*ADDRESS’ d4799 2 a4800 2 ‘FUNCTION’ ‘-function FUNCTION’ d4806 1 a4806 1 described in *note Location Specifications::. d4808 3 a4810 3 ‘delete [breakpoints] [LIST...]’ Delete the breakpoints, watchpoints, tracepoints, or catchpoints of the breakpoint list specified as argument. If no argument is d4812 2 a4813 2 catchpoints (GDB asks confirmation, unless you have ‘set confirm off’). You can abbreviate this command as ‘d’. d4822 1 a4822 1 prefer to “disable” it. This makes the breakpoint inoperative as if it d4824 1 a4824 1 that you can “enable” it again later. d4827 4 a4830 4 catchpoints with the ‘enable’ and ‘disable’ commands, optionally specifying one or more breakpoint numbers as arguments. Use ‘info break’ to print a list of all breakpoints, watchpoints, tracepoints, and catchpoints if you do not know which numbers to use. d4838 6 a4843 4 • Enabled. The breakpoint stops your program. A breakpoint set with the ‘break’ command starts out in this state. • Disabled. The breakpoint has no effect on your program. • Enabled once. The breakpoint stops your program, but then becomes d4845 2 a4846 1 • Enabled for a count. The breakpoint stops your program for the d4848 2 a4849 1 • Enabled for deletion. The breakpoint stops your program, but d4851 1 a4851 1 breakpoint set with the ‘tbreak’ command starts out in this state. d4856 1 a4856 1 ‘disable [breakpoints] [LIST...]’ d4861 1 a4861 1 abbreviate ‘disable’ as ‘dis’. d4863 1 a4863 1 ‘enable [breakpoints] [LIST...]’ d4867 1 a4867 1 ‘enable [breakpoints] once LIST...’ d4871 1 a4871 1 ‘enable [breakpoints] count COUNT LIST...’ d4879 1 a4879 1 ‘enable [breakpoints] delete LIST...’ d4882 1 a4882 1 there. Breakpoints set by the ‘tbreak’ command start out in this d4885 6 a4890 6 Except for a breakpoint set with ‘tbreak’ (*note Setting Breakpoints: Set Breaks.), breakpoints that you set are initially enabled; subsequently, they become disabled or enabled only when you use one of the commands above. (The command ‘until’ can set and delete a breakpoint of its own, but it does not change the state of your other breakpoints; see *note Continuing and Stepping: Continuing and d4900 1 a4900 1 specified place. You can also specify a “condition” for a breakpoint. d4908 3 a4910 3 is, when the condition is false. In C, if you want to test an assertion expressed by the condition ASSERT, you should set the condition ‘! ASSERT’ on the appropriate breakpoint. d4922 6 a4927 6 there is another enabled breakpoint at the same address. (In that case, GDB might see the other breakpoint first and stop your program without checking the condition of this one.) Note that breakpoint commands are usually more convenient and flexible than break conditions for the purpose of performing side effects when a breakpoint is reached (*note Breakpoint Command Lists: Break Commands.). d4943 1 a4943 1 ‘if’ in the arguments to the ‘break’ command. *Note Setting d4945 1 a4945 1 ‘condition’ command. d4947 2 a4948 2 You can also use the ‘if’ keyword with the ‘watch’ command. The ‘catch’ command does not recognize the ‘if’ keyword; ‘condition’ is the d4951 1 a4951 1 ‘condition BNUM EXPRESSION’ d4955 1 a4955 1 is true (nonzero, in C). When you use ‘condition’, GDB checks d4964 2 a4965 2 ‘condition’ command (or a command that sets a breakpoint with a condition, like ‘break if ...’) is given, however. *Note d4968 2 a4969 2 ‘condition -force BNUM EXPRESSION’ When the ‘-force’ flag is used, define the condition even if d4971 2 a4972 2 BNUM. This is similar to the ‘-force-condition’ option of the ‘break’ command. d4974 1 a4974 1 ‘condition BNUM’ d4980 2 a4981 2 useful that there is a special way to do it, using the “ignore count” of the breakpoint. Every breakpoint has an ignore count, which is an d4989 1 a4989 1 ‘ignore BNUM COUNT’ d4998 4 a5001 4 When you use ‘continue’ to resume execution of your program from a breakpoint, you can specify an ignore count directly as an argument to ‘continue’, rather than using ‘ignore’. *Note Continuing and Stepping: Continuing and Stepping. d5008 3 a5010 3 such as ‘$foo-- <= 0’ using a debugger convenience variable that is decremented each time. *Note Convenience Variables: Convenience Vars. d5026 3 a5028 3 ‘commands [LIST...]’ ‘... COMMAND-LIST ...’ ‘end’ d5031 1 a5031 1 just ‘end’ to terminate the commands. d5033 2 a5034 2 To remove all commands from a breakpoint, type ‘commands’ and follow it immediately with ‘end’; that is, give no commands. d5036 1 a5036 1 With no argument, ‘commands’ refers to the last breakpoint, d5039 1 a5039 1 single command, then the ‘commands’ will apply to all the d5041 3 a5043 3 by ‘rbreak’, and also applies when a single ‘break’ command creates multiple breakpoints (*note Ambiguous Expressions: Ambiguous Expressions.). d5048 1 a5048 1 Inside a command list, you can use the command ‘disable $_hit_bpnum’ d5051 2 a5052 2 If your breakpoint has several code locations, the command ‘disable $_hit_bpnum.$_hit_locno’ will disable the specific breakpoint code d5057 1 a5057 1 Simply use the ‘continue’ command, or ‘step’, or any other command that d5062 1 a5062 1 (even with a simple ‘next’ or ‘step’), you may encounter another d5066 1 a5066 1 If the first command you specify in a command list is ‘silent’, the d5070 1 a5070 1 see no sign that the breakpoint was reached. ‘silent’ is meaningful d5073 3 a5075 3 The commands ‘echo’, ‘output’, and ‘printf’ allow you to print precisely controlled output, and are often useful in silent breakpoints. *Note Commands for Controlled Output: Output. d5078 1 a5078 1 the value of ‘x’ at entry to ‘foo’ whenever ‘x’ is positive. d5091 2 a5092 2 to any variables that need them. End with the ‘continue’ command so that your program does not stop, and start with the ‘silent’ command so d5108 1 a5108 1 The dynamic printf command ‘dprintf’ combines a breakpoint with d5110 2 a5111 2 inserting ‘printf’ calls into your program on-the-fly, without having to recompile it. d5114 1 a5114 1 you can set the variable ‘dprintf-style’ for alternate handling. For d5116 3 a5118 3 ‘printf’ function. This has the advantage that the characters go to the program's output device, so they can recorded in redirects to files and so forth. d5128 1 a5128 1 ‘dprintf LOCSPEC,TEMPLATE,EXPRESSION[,EXPRESSION...]’ d5134 1 a5134 1 ‘set dprintf-style STYLE’ d5141 3 a5143 3 ‘gdb’ Handle the output using the GDB ‘printf’ command. When using this style, it is possible to use the ‘%V’ format specifier d5146 1 a5146 1 ‘call’ d5148 1 a5148 1 (normally ‘printf’). When using this style the supported d5153 4 a5156 4 the ‘printf’ function, however, GDB's ‘%V’ format specifier extension is not supported by ‘printf’. When using ‘call’ style dprintf, care should be taken to ensure that only format specifiers supported by the output function are used, d5159 2 a5160 2 ‘agent’ Have the remote debugging agent (such as ‘gdbserver’) handle d5163 1 a5163 1 not support the ‘%V’ format specifier. d5165 9 a5173 9 ‘set dprintf-function FUNCTION’ Set the function to call if the dprintf style is ‘call’. By default its value is ‘printf’. You may set it to any expression that GDB can evaluate to a function, as per the ‘call’ command. ‘set dprintf-channel CHANNEL’ Set a "channel" for dprintf. If set to a non-empty value, GDB will evaluate it as an expression and pass the result as a first argument to the ‘dprintf-function’, in the manner of ‘fprintf’ and d5175 1 a5175 1 the first argument, in the manner of ‘printf’. d5177 3 a5179 3 As an example, if you wanted ‘dprintf’ output to go to a logfile that is a standard I/O stream assigned to the variable ‘mylog’, you could do the following: d5192 1 a5192 1 Note that the ‘info break’ displays the dynamic printf commands as d5196 8 a5203 5 ‘set disconnected-dprintf on’ ‘set disconnected-dprintf off’ Choose whether ‘dprintf’ commands should continue to run if GDB has disconnected from the target. This only applies if the ‘dprintf-style’ is ‘agent’. a5204 2 ‘show disconnected-dprintf off’ Show the current choice for disconnected ‘dprintf’. d5219 1 a5219 1 To save breakpoint definitions to a file use the ‘save breakpoints’ d5222 1 a5222 1 ‘save breakpoints [FILENAME]’ d5224 1 a5224 1 their commands and ignore counts, into a file ‘FILENAME’ suitable d5227 1 a5227 1 To read the saved breakpoint definitions, use the ‘source’ command d5230 6 a5235 6 not be possible to access the context where the watchpoint is valid anymore. Because the saved breakpoint definitions are simply a sequence of GDB commands that recreate the breakpoints, you can edit the file in your favorite editing program, and remove the breakpoint definitions you're not interested in, or that can no longer be recreated. d5243 3 a5245 3 GDB supports “SDT” probes in the code. SDT stands for Statically Defined Tracing, and the probes are designed to have a tiny runtime code and data footprint, and no dynamic relocations. d5250 2 a5251 2 • ‘SystemTap’ () SDT probes(1). ‘SystemTap’ probes are usable from assembly, C and C++ d5254 2 a5255 2 • ‘DTrace’ () USDT probes. ‘DTrace’ probes are usable from C and C++ languages. d5257 1 a5257 1 Some ‘SystemTap’ probes have an associated semaphore variable; for d5259 1 a5259 1 DTrace-style ‘.d’ file. If your probe has a semaphore, GDB will d5261 3 a5263 3 ‘-probe-stap’ notation. But, if you put a breakpoint at a probe's location by some other method (e.g., ‘break file:line’), then GDB will not automatically set the semaphore. ‘DTrace’ probes do not support d5266 2 a5267 2 You can examine the available static static probes using ‘info probes’, with optional arguments: d5269 3 a5271 3 ‘info probes [TYPE] [PROVIDER [NAME [OBJFILE]]]’ If given, TYPE is either ‘stap’ for listing ‘SystemTap’ probes or ‘dtrace’ for listing ‘DTrace’ probes. If omitted all probes are d5286 1 a5286 1 ‘info probes all’ d5291 2 a5292 2 handled. Some ‘DTrace’ probes can be enabled or disabled, but ‘SystemTap’ probes cannot be disabled. d5297 1 a5297 1 ‘enable probes [PROVIDER [NAME [OBJFILE]]]’ d5302 3 a5304 3 If given, NAME is a regular expression to match against probe names when selecting which probes to enable. If omitted, probe names are not considered when deciding whether to enable them. d5310 2 a5311 2 ‘disable probes [PROVIDER [NAME [OBJFILE]]]’ See the ‘enable probes’ command above for a description of the d5318 6 a5323 6 ‘$_probe_arg0’...‘$_probe_arg11’. In ‘SystemTap’ probes each probe argument is an integer of the appropriate size; types are not preserved. In ‘DTrace’ probes types are preserved provided that they are recognized as such by GDB; otherwise the value of the probe argument will be a long integer. The convenience variable ‘$_probe_argc’ holds the number of arguments at the current probe point. d5332 2 a5333 2 for more information on how to add ‘SystemTap’ SDT probes in your d5337 1 a5337 1 for d5365 3 a5367 3 Some processor architectures place constraints on the addresses at which breakpoints may be placed. For architectures thus constrained, GDB will attempt to adjust the breakpoint's address to comply with the d5370 1 a5370 1 One example of such an architecture is the Fujitsu FR-V. The FR-V is d5373 4 a5376 3 constrains the location of a breakpoint instruction within such a bundle to the instruction with the lowest address. GDB honors this constraint by adjusting a breakpoint's address to the first in the bundle. d5379 6 a5384 5 instructions from different source statements, thus it may happen that a breakpoint's address will be adjusted from one source statement to another. Since this adjustment may significantly alter GDB's breakpoint related behavior from what the user expects, a warning is printed when the breakpoint is first set and also when the breakpoint is hit. d5392 7 a5398 7 breakpoints. If you see one of these warnings, you should verify that a breakpoint set at the adjusted address will have the desired affect. If not, the breakpoint in question may be removed and other breakpoints may be set which will have the desired behavior. E.g., it may be sufficient to place the breakpoint at a later instruction. A conditional breakpoint may also be useful in some cases to prevent the breakpoint from triggering too often. d5416 2 a5417 2 “Continuing” means resuming program execution until your program completes normally. In contrast, “stepping” means executing just one d5420 9 a5428 9 command you use). Either when continuing or when stepping, your program may stop even sooner, due to a breakpoint or a signal. (If it stops due to a signal, you may want to use ‘handle’, or use ‘signal 0’ to resume execution (*note Signals: Signals.), or you may step into the signal's handler (*note stepping and signal handlers::).) ‘continue [IGNORE-COUNT]’ ‘c [IGNORE-COUNT]’ ‘fg [IGNORE-COUNT]’ d5432 3 a5434 2 number of times to ignore a breakpoint at this location; its effect is like that of ‘ignore’ (*note Break Conditions: Conditions.). d5438 1 a5438 1 ‘continue’ is ignored. d5440 8 a5447 7 The synonyms ‘c’ and ‘fg’ (for “foreground”, as the debugged program is deemed to be the foreground program) are provided purely for convenience, and have exactly the same behavior as ‘continue’. To resume execution at a different place, you can use ‘return’ (*note Returning from a Function: Returning.) to go back to the calling function; or ‘jump’ (*note Continuing at a Different Address: Jumping.) d5457 1 a5457 1 ‘step’ d5460 1 a5460 1 is abbreviated ‘s’. d5462 1 a5462 1 _Warning:_ If you use the ‘step’ command while control is d5468 1 a5468 1 debugging information, use the ‘stepi’ command, described d5471 1 a5471 1 The ‘step’ command only stops at the first instruction of a source d5473 4 a5476 4 in ‘switch’ statements, ‘for’ loops, etc. ‘step’ continues to stop if a function that has debugging information is called within the line. In other words, ‘step’ _steps inside_ any functions called within the line. d5478 1 a5478 1 Also, the ‘step’ command only enters a function if there is line d5480 2 a5481 2 ‘next’ command. This avoids problems when using ‘cc -gl’ on MIPS machines. Previously, ‘step’ entered subroutines if there was any d5484 2 a5485 2 ‘step COUNT’ Continue running as in ‘step’, but do so COUNT times. If a d5489 1 a5489 1 ‘next [COUNT]’ d5491 1 a5491 1 frame. This is similar to ‘step’, but function calls that appear d5493 3 a5495 3 stops when control reaches a different line of code at the original stack level that was executing when you gave the ‘next’ command. This command is abbreviated ‘n’. d5497 1 a5497 1 An argument COUNT is a repeat count, as for ‘step’. d5499 1 a5499 1 The ‘next’ command only stops at the first instruction of a source d5501 1 a5501 1 ‘switch’ statements, ‘for’ loops, etc. d5503 4 a5506 4 ‘set step-mode’ ‘set step-mode on’ The ‘set step-mode on’ command causes the ‘step’ command to stop at the first instruction of a function which contains no debug line d5513 7 a5519 7 ‘set step-mode off’ Causes the ‘step’ command to step over any functions which contains no debug information. This is the default. ‘show step-mode’ Show whether GDB will stop in or step over functions without source line debug information. d5521 1 a5521 1 ‘finish’ d5524 1 a5524 1 can be abbreviated as ‘fin’. d5526 1 a5526 1 Contrast this with the ‘return’ command (*note Returning from a d5529 5 a5533 5 ‘set print finish [on|off]’ ‘show print finish’ By default the ‘finish’ command will show the value that is returned by the function. This can be disabled using ‘set print finish off’. When disabled, the value is still entered into the d5536 2 a5537 2 ‘until’ ‘u’ d5541 1 a5541 1 ‘next’ command, except that when ‘until’ encounters a jump, it d5546 2 a5547 2 stepping though it, ‘until’ makes your program continue execution until it exits the loop. In contrast, a ‘next’ command at the end d5551 1 a5551 1 ‘until’ always stops your program if it attempts to exit the d5554 1 a5554 1 ‘until’ may produce somewhat counterintuitive results if the order d5556 3 a5558 3 example, in the following excerpt from a debugging session, the ‘f’ (‘frame’) command shows that execution is stopped at line ‘206’; yet when we use ‘until’, we get to line ‘195’: d5568 2 a5569 2 the start, of the loop--even though the test in a C ‘for’-loop is written before the body of the loop. The ‘until’ command appeared d5574 2 a5575 2 ‘until’ with no argument works by means of single instruction stepping, and hence is slower than ‘until’ with an argument. d5577 2 a5578 2 ‘until LOCSPEC’ ‘u LOCSPEC’ d5581 10 a5590 9 frame returns. LOCSPEC is any of the forms described in *note Location Specifications::. This form of the command uses temporary breakpoints, and hence is quicker than ‘until’ without an argument. The specified location is actually reached only if it is in the current frame. This implies that ‘until’ can be used to skip over recursive function invocations. For instance in the code below, if the current location is line ‘96’, issuing ‘until 99’ will execute the program up to line ‘99’ in the same invocation of factorial, i.e., after the inner invocations have returned. d5600 1 a5600 1 ‘advance LOCSPEC’ d5603 3 a5605 3 frame returns. LOCSPEC is any of the forms described in *note Location Specifications::. This command is similar to ‘until’, but ‘advance’ will not skip over recursive function calls, and the d5609 3 a5611 3 ‘stepi’ ‘stepi ARG’ ‘si’ d5615 1 a5615 1 It is often useful to do ‘display/i $pc’ when stepping by machine d5620 1 a5620 1 An argument is a repeat count, as in ‘step’. d5622 3 a5624 3 ‘nexti’ ‘nexti ARG’ ‘ni’ d5628 1 a5628 1 An argument is a repeat count, as in ‘next’. a5629 10 By default, and if available, GDB makes use of target-assisted “range stepping”. In other words, whenever you use a stepping command (e.g., ‘step’, ‘next’), GDB tells the target to step the corresponding range of instruction addresses instead of issuing multiple single-steps. This speeds up line stepping, particularly for remote targets. Ideally, there should be no reason you would want to turn range stepping off. However, it's possible that a bug in the debug info, a bug in the remote stub (for remote targets), or even a bug in GDB could make line stepping behave incorrectly when target-assisted range stepping is enabled. You can use the following command to turn off range stepping if necessary: d5631 14 a5644 2 ‘set range-stepping’ ‘show range-stepping’ d5647 5 a5651 4 If ‘on’, and the target supports it, GDB tells the target to step a range of addresses itself, instead of issuing multiple single-steps. If ‘off’, GDB always issues single-steps, even if range stepping is supported by the target. The default is ‘on’. d5660 1 a5660 1 uninteresting to debug. The ‘skip’ command lets you tell GDB to skip a d5672 4 a5675 4 Suppose you wish to step into the functions ‘foo’ and ‘bar’, but you are not interested in stepping through ‘boring’. If you run ‘step’ at line 103, you'll enter ‘boring()’, but if you run ‘next’, you'll step over both ‘foo’ and ‘boring’! d5677 2 a5678 2 One solution is to ‘step’ into ‘boring’ and use the ‘finish’ command to immediately exit it. But this can become tedious if ‘boring’ is d5681 3 a5683 3 A more flexible solution is to execute ‘skip boring’. This instructs GDB never to step into ‘boring’. Now when you execute ‘step’ at line 103, you'll step over ‘boring’ and directly into ‘foo’. d5687 1 a5687 1 matches the function's name, file name or a ‘glob’-style pattern that d5691 1 a5691 1 Regular Expressions". See for example ‘man 7 regex’ on GNU/Linux d5693 3 a5695 3 whatever is provided by the ‘regcomp’ function of the underlying system. See for example ‘man 7 glob’ on GNU/Linux systems for a description of ‘glob’-style patterns. d5697 2 a5698 2 ‘skip [OPTIONS]’ The basic form of the ‘skip’ command takes zero or more options d5702 2 a5703 2 ‘-file FILE’ ‘-fi FILE’ d5706 2 a5707 2 ‘-gfile FILE-GLOB-PATTERN’ ‘-gfi FILE-GLOB-PATTERN’ d5713 2 a5714 2 ‘-function LINESPEC’ ‘-fu LINESPEC’ d5719 2 a5720 2 ‘-rfunction REGEXP’ ‘-rfu REGEXP’ d5725 1 a5725 1 there is generally no need to step into C++ ‘std::string’ d5728 3 a5730 3 it doesn't matter what the template arguments are. Specifying the function to be skipped as a regular expression makes this easier. d5735 1 a5735 1 destructor in the ‘std’ namespace you can do: d5742 1 a5742 1 ‘skip function [LINESPEC]’ d5744 2 a5745 2 function containing the line named by LINESPEC will be skipped over when stepping. *Note Location Specifications::. d5750 2 a5751 2 (If you have a function called ‘file’ that you want to skip, use ‘skip function file’.) d5753 1 a5753 1 ‘skip file [FILENAME]’ d5760 2 a5761 2 If you do not specify FILENAME, functions whose source lives in the file you're currently debugging will be skipped. d5766 1 a5766 1 ‘info skip [RANGE]’ d5768 3 a5770 3 specified, print a table with details about all functions and files marked for skipping. ‘info skip’ prints the following information about each skip: d5772 1 a5772 1 _Identifier_ a5773 15 _Enabled or Disabled_ Enabled skips are marked with ‘y’. Disabled skips are marked with ‘n’. _Glob_ If the file name is a ‘glob’ pattern this is ‘y’. Otherwise it is ‘n’. _File_ The name or ‘glob’ pattern of the file to be skipped. If no file is specified this is ‘’. _RE_ If the function name is a ‘regular expression’ this is ‘y’. Otherwise it is ‘n’. _Function_ The name or regular expression of the function to skip. If no function is specified this is ‘’. d5775 21 a5795 1 ‘skip delete [RANGE]’ d5799 1 a5799 1 ‘skip enable [RANGE]’ d5803 1 a5803 1 ‘skip disable [RANGE]’ d5807 1 a5807 1 ‘set debug skip [on|off]’ d5811 4 a5814 3 ‘show debug skip’ Show whether the debug output about skipping files and functions is printed. d5824 4 a5827 4 kind a name and a number. For example, in Unix ‘SIGINT’ is the signal a program gets when you type an interrupt character (often ‘Ctrl-c’); ‘SIGSEGV’ is the signal a program gets from referencing a place in memory far away from all the areas in use; ‘SIGALRM’ occurs when the d5831 7 a5837 7 Some signals, including ‘SIGALRM’, are a normal part of the functioning of your program. Others, such as ‘SIGSEGV’, indicate errors; these signals are “fatal” (they kill your program immediately) if the program has not specified in advance some other way to handle the signal. ‘SIGINT’ does not indicate an error in your program, but it is normally fatal so it can carry out the purpose of the interrupt: to kill the program. d5844 1 a5844 1 ‘SIGALRM’ be silently passed to your program (so as not to interfere d5847 1 a5847 1 settings with the ‘handle’ command. d5849 5 a5853 5 ‘info signals’ ‘info handle’ Print a table of all the kinds of signals and how GDB has been told to handle each one. You can use this to see the signal numbers of all the defined types of signals. d5855 1 a5855 1 ‘info signals SIG’ d5859 1 a5859 1 ‘info handle’ is an alias for ‘info signals’. d5861 1 a5861 1 ‘catch signal [SIGNAL... | ‘all’]’ d5865 1 a5865 1 ‘handle SIGNAL [ SIGNAL ... ] [KEYWORDS...]’ d5867 4 a5870 4 number of a signal or its name (with or without the ‘SIG’ at the beginning); a list of signal numbers of the form ‘LOW-HIGH’; or the word ‘all’, meaning all the known signals, except ‘SIGINT’ and ‘SIGTRAP’, which are used by GDB. Optional argument KEYWORDS, d5874 1 a5874 1 The keywords allowed by the ‘handle’ command can be abbreviated. d5877 1 a5877 1 ‘nostop’ d5881 1 a5881 1 ‘stop’ d5883 1 a5883 1 implies the ‘print’ keyword as well. d5885 1 a5885 1 ‘print’ d5888 1 a5888 1 ‘noprint’ d5890 1 a5890 1 implies the ‘nostop’ keyword as well. d5892 2 a5893 2 ‘pass’ ‘noignore’ d5896 1 a5896 1 and not handled. ‘pass’ and ‘noignore’ are synonyms. d5898 4 a5901 4 ‘nopass’ ‘ignore’ GDB should not allow your program to see this signal. ‘nopass’ and ‘ignore’ are synonyms. d5905 8 a5912 8 ‘pass’ is in effect for the signal in question _at that time_. In other words, after GDB reports a signal, you can use the ‘handle’ command with ‘pass’ or ‘nopass’ to control whether your program sees that signal when you continue. The default is set to ‘nostop’, ‘noprint’, ‘pass’ for non-erroneous signals such as ‘SIGALRM’, ‘SIGWINCH’ and ‘SIGCHLD’, and to ‘stop’, ‘print’, ‘pass’ for the erroneous signals. d5914 1 a5914 1 You can also use the ‘signal’ command to prevent your program from d5921 1 a5921 1 you can continue with ‘signal 0’. *Note Giving your Program a Signal: d5925 2 a5926 2 ‘handle nostop’ and ‘handle pass’ set arrives while a stepping command (e.g., ‘stepi’, ‘step’, ‘next’) is in progress, GDB lets the signal d5930 11 a5940 11 ‘handle nostop’) from changing the focus of debugging unexpectedly. Note that the signal handler itself may still hit a breakpoint, stop for another signal that has ‘handle stop’ in effect, or for any other event that normally results in stopping the stepping command sooner. Also note that GDB still informs you that the program received a signal if ‘handle print’ is set. If you set ‘handle pass’ for a signal, and your program sets up a handler for it, then issuing a stepping command, such as ‘step’ or ‘stepi’, when your program is stopped due to the signal will step _into_ the signal handler (if the target supports that). d5942 1 a5942 1 Likewise, if you use the ‘queue-signal’ command to queue a signal to d5947 2 a5948 2 Here's an example, using ‘stepi’ to step to the first instruction of ‘SIGUSR1’'s handler: d5963 2 a5964 2 The same, but using ‘queue-signal’ instead of waiting for the program to receive the signal first: d5976 7 a5982 7 program being debugged. This information is exported by the convenience variable ‘$_siginfo’, and consists of data that is passed by the kernel to the signal handler at the time of the receipt of a signal. The data type of the information itself is target dependent. You can see the data type using the ‘ptype $_siginfo’ command. On Unix systems, it typically corresponds to the standard ‘siginfo_t’ type, as defined in the ‘signal.h’ system header. d6013 1 a6013 1 Depending on target support, ‘$_siginfo’ may also be writable. d6015 7 a6021 7 On some targets, a ‘SIGSEGV’ can be caused by a boundary violation, i.e., accessing an address outside of the allowed range. In those cases GDB may displays additional information, depending on how GDB has been told to handle the signal. With ‘handle stop SIGSEGV’, GDB displays the violation kind: "Upper" or "Lower", the memory address accessed and the bounds, while with ‘handle nostop SIGSEGV’ no additional information is displayed. d6044 6 a6049 5 default mode, referred to as “all-stop mode”, when any thread in your program stops (for example, at a breakpoint or while being stepped), all other threads in the program are also stopped by GDB. On some targets, GDB also supports “non-stop mode”, in which other threads can continue to run freely while you examine the stopped thread in the debugger. d6074 1 a6074 1 ‘step’ or ‘next’. d6076 6 a6081 6 In particular, GDB cannot single-step all threads in lockstep. Since thread scheduling is up to your debugging target's operating system (not controlled by GDB), other threads may execute more than one statement while the current thread completes a single step. Moreover, in general other threads stop in the middle of a statement, rather than at a clean statement boundary, when the program stops. d6091 1 a6091 1 ‘[Switching to Thread N]’ to identify the thread. d6093 2 a6094 2 On some OSes, you can modify GDB's default behavior by locking the OS scheduler to allow only a single thread to run. d6096 1 a6096 1 ‘set scheduler-locking MODE’ d6100 1 a6100 1 ‘off’ d6103 1 a6103 1 ‘on’ d6105 2 a6106 2 New threads created by the resumed thread are held stopped at their entry point, before they execute any instruction. d6108 5 a6112 5 ‘step’ Behaves like ‘on’ when stepping, and ‘off’ otherwise. Threads other than the current never get a chance to run when you step, and they are completely free to run when you use commands like ‘continue’, ‘until’, or ‘finish’. d6121 2 a6122 2 ‘replay’ Behaves like ‘on’ in replay mode, and ‘off’ in either record d6125 1 a6125 1 ‘show scheduler-locking’ d6129 11 a6139 11 ‘continue’, ‘next’ or ‘step’, GDB allows only threads of the current inferior to run. For example, if GDB is attached to two inferiors, each with two threads, the ‘continue’ command resumes only the two threads of the current inferior. This is useful, for example, when you debug a program that forks and you want to hold the parent stopped (so that, for instance, it doesn't run to exit), while you debug the child. In other situations, you may not be interested in inspecting the current state of any of the processes GDB is attached to, and you may want to resume them all until some breakpoint is hit. In the latter case, you can instruct GDB to allow all threads of all the inferiors to run with the ‘set schedule-multiple’ command. d6141 1 a6141 1 ‘set schedule-multiple’ d6143 5 a6147 5 resumed when an execution command is issued. When ‘on’, all threads of all processes are allowed to run. When ‘off’, only the threads of the current process are resumed. The default is ‘off’. The ‘scheduler-locking’ mode takes precedence when set to ‘on’, or while you are stepping and set to ‘step’. d6149 1 a6149 1 ‘show schedule-multiple’ d6161 4 a6164 4 debugger while other threads continue to execute freely. This minimizes intrusion when debugging live systems, such as programs where some threads have real-time constraints or must continue to respond to external events. This is referred to as “non-stop” mode. d6169 1 a6169 1 commands such as ‘continue’ and ‘step’ apply by default only to the d6188 1 a6188 1 ‘set non-stop on’ d6190 5 a6194 3 ‘set non-stop off’ Disable selection of non-stop mode. ‘show non-stop’ d6199 1 a6199 1 mode. In particular, the ‘set non-stop’ preference is only consulted d6206 2 a6207 2 thread by default. That is, ‘continue’ only continues one thread. To continue all threads, issue ‘continue -a’ or ‘c -a’. d6210 2 a6211 2 Execution::) to run some threads in the background while you continue to examine or step others from GDB. The MI execution commands (*note d6215 2 a6216 2 Suspending execution is done with the ‘interrupt’ command when running in the background, or ‘Ctrl-c’ during foreground execution. In d6219 1 a6219 1 program, use ‘interrupt -a’. d6221 1 a6221 1 Other execution commands do not currently support the ‘-a’ option. d6225 4 a6228 4 thread stop notifications are asynchronous with respect to GDB's command interpreter, and it would be confusing if GDB unexpectedly changed to a different thread just as you entered a command to operate on the previously current thread. d6236 1 a6236 1 GDB's execution commands have two variants: the normal foreground d6243 2 a6244 2 If the target doesn't support async mode, GDB issues an error message if you attempt to use the background execution commands. d6246 3 a6248 3 To specify background execution, add a ‘&’ to the command. For example, the background form of the ‘continue’ command is ‘continue&’, or just ‘c&’. The execution commands that accept background execution d6251 1 a6251 1 ‘run’ d6254 1 a6254 1 ‘attach’ d6257 1 a6257 1 ‘step’ d6260 1 a6260 1 ‘stepi’ d6263 1 a6263 1 ‘next’ d6266 1 a6266 1 ‘nexti’ d6269 1 a6269 1 ‘continue’ d6272 1 a6272 1 ‘finish’ d6275 1 a6275 1 ‘until’ d6278 1 d6280 6 a6285 6 non-stop mode for debugging programs with multiple threads; see *note Non-Stop Mode::. However, you can also use these commands in the normal all-stop mode with the restriction that you cannot issue another execution command until the previous one finishes. Examples of commands that are valid in all-stop mode while the program is running include ‘help’ and ‘info break’. d6288 1 a6288 4 by using the ‘interrupt’ command. ‘interrupt’ ‘interrupt -a’ d6290 2 d6293 1 a6293 1 ‘interrupt’ stops the whole process, but in non-stop mode, it stops d6295 1 a6295 1 mode, use ‘interrupt -a’. d6307 2 a6308 2 ‘break LOCSPEC thread THREAD-ID’ ‘break LOCSPEC thread THREAD-ID if ...’ d6312 1 a6312 1 Use the qualifier ‘thread THREAD-ID’ with a breakpoint command to d6316 1 a6316 1 first column of the ‘info threads’ display. d6318 3 a6320 2 If you do not specify ‘thread THREAD-ID’ when you set a breakpoint, the breakpoint applies to _all_ threads of your program. d6322 2 a6323 2 You can use the ‘thread’ qualifier on conditional breakpoints as well; in this case, place ‘thread THREAD-ID’ before or after the d6328 1 d6337 6 a6342 6 thread exit, but also when you detach from the process with the ‘detach’ command (*note Debugging an Already-running Process: Attach.), or if GDB loses the remote connection (*note Remote Debugging::), etc. Note that with some targets, GDB is only able to detect a thread has exited when the user explicitly asks for the thread list with the ‘info threads’ command. d6346 1 a6346 1 Tasks::); using more than one of the ‘thread’, ‘inferior’, or ‘task’ d6370 1 a6370 1 The call to ‘sleep’ will return early if a different thread stops at d6380 2 a6381 2 conforming to its specification. But GDB does cause your multi-threaded program to behave differently than it would without GDB. d6400 2 a6401 2 When all of these are set to ‘off’, then GDB is said to be “observer mode”. As a convenience, the variable ‘observer’ can be set to disable d6405 2 a6406 2 combinations of these settings. For instance, if you have enabled ‘may-insert-breakpoints’ but disabled ‘may-write-memory’, then d6410 5 a6414 5 ‘set observer on’ ‘set observer off’ When set to ‘on’, this disables all the permission variables below (except for ‘insert-fast-tracepoints’), plus enables non-stop debugging. Setting this to ‘off’ switches back to normal d6417 1 a6417 1 ‘show observer’ d6420 2 a6421 2 ‘set may-write-registers on’ ‘set may-write-registers off’ d6423 2 a6424 2 registers, such as with assignment expressions in ‘print’, or the ‘jump’ command. It defaults to ‘on’. d6426 1 a6426 1 ‘show may-write-registers’ d6429 2 a6430 2 ‘set may-write-memory on’ ‘set may-write-memory off’ d6432 2 a6433 2 memory, such as with assignment expressions in ‘print’. It defaults to ‘on’. d6435 1 a6435 1 ‘show may-write-memory’ d6438 5 a6442 5 ‘set may-insert-breakpoints on’ ‘set may-insert-breakpoints off’ This controls whether GDB will attempt to insert breakpoints. This affects all breakpoints, including internal breakpoints defined by GDB. It defaults to ‘on’. d6444 1 a6444 1 ‘show may-insert-breakpoints’ d6447 2 a6448 2 ‘set may-insert-tracepoints on’ ‘set may-insert-tracepoints off’ d6451 2 a6452 2 only non-fast tracepoints, fast tracepoints being under the control of ‘may-insert-fast-tracepoints’. It defaults to ‘on’. d6454 1 a6454 1 ‘show may-insert-tracepoints’ d6457 2 a6458 2 ‘set may-insert-fast-tracepoints on’ ‘set may-insert-fast-tracepoints off’ d6461 2 a6462 2 tracepoints, regular (non-fast) tracepoints being under the control of ‘may-insert-tracepoints’. It defaults to ‘on’. d6464 1 a6464 1 ‘show may-insert-fast-tracepoints’ d6467 6 a6472 5 ‘set may-interrupt on’ ‘set may-interrupt off’ This controls whether GDB will attempt to interrupt or stop program execution. When this variable is ‘off’, the ‘interrupt’ command will have no effect, nor will ‘Ctrl-c’. It defaults to ‘on’. d6474 1 a6474 1 ‘show may-interrupt’ d6477 1 d6491 3 a6493 3 program was executing normally. Variables, registers etc. should revert to their previous values. Obviously this requires a great deal of sophistication on the part of the target environment; not all target d6506 1 a6506 1 activated with the ‘record’ or ‘record btrace’ commands. *Note Process d6514 2 a6515 2 ‘reverse-continue [IGNORE-COUNT]’ ‘rc [IGNORE-COUNT]’ d6521 1 a6521 1 ‘reverse-step [COUNT]’ d6525 1 a6525 1 Like the ‘step’ command, ‘reverse-step’ will only stop at the d6528 1 a6528 1 to debuggable functions, ‘reverse-step’ will step (backward) into d6532 2 a6533 2 Also, as with the ‘step’ command, if non-debuggable functions are called, ‘reverse-step’ will run thru them backward without d6536 1 a6536 1 ‘reverse-stepi [COUNT]’ d6540 1 a6540 1 instance, if the last instruction was a jump, ‘reverse-stepi’ will d6544 1 a6544 1 ‘reverse-next [COUNT]’ d6548 4 a6551 4 the first line of a function, ‘reverse-next’ will take you back to the caller of that function, _before_ the function was called, just as the normal ‘next’ command would take you from the last line of a function back to its return to its caller (2). d6553 2 a6554 2 ‘reverse-nexti [COUNT]’ Like ‘nexti’, ‘reverse-nexti’ executes a single instruction in d6557 1 a6557 1 another function, ‘reverse-nexti’ will continue to execute in d6561 3 a6563 3 ‘reverse-finish’ Just as the ‘finish’ command takes you to the point where the current function returns, ‘reverse-finish’ takes you to the point d6567 1 a6567 1 ‘set exec-direction’ d6569 2 a6570 1 ‘set exec-direction reverse’ d6573 4 a6576 3 include ‘step, stepi, next, nexti, continue, and finish’. The ‘return’ command cannot be used in reverse mode. ‘set exec-direction forward’ d6602 1 a6602 1 On some platforms, GDB provides a special “process record and replay” d6607 1 a6607 1 for the next instruction, GDB will debug in “replay mode”. In the d6616 1 a6616 1 GDB will debug in “record mode”. In this mode, the inferior executes d6626 2 a6627 2 When debugging in the reverse direction, GDB will work in replay mode as long as the execution log includes the record for the previous d6634 1 a6634 1 debugging, and when remote debugging via ‘gdbserver’. d6639 1 a6639 1 ‘record METHOD’ d6642 1 a6642 1 parameter the command uses the ‘full’ recording method. The d6645 1 a6645 1 ‘full’ d6650 1 a6650 1 ‘btrace FORMAT’ d6657 3 a6659 3 continues on disconnect. Recorded data can be inspected after reconnecting. The recording may be stopped using ‘record stop’. d6661 2 a6662 2 The recording format can be specified as parameter. Without a parameter the command chooses the recording format. The d6665 2 a6666 2 ‘bts’ Use the “Branch Trace Store” (BTS) recording format. In d6670 2 a6671 2 ‘pt’ Use the “Intel Processor Trace” recording format. In d6680 3 a6682 3 Decoding the recorded execution trace, on the other hand, is more expensive than decoding BTS trace. This is mostly due to the increased number of instructions to d6688 3 a6690 3 is already running. Therefore, you need first to start the process with the ‘run’ or ‘start’ commands, and then start the recording with the ‘record METHOD’ command. d6693 1 a6693 1 Commands.) will be automatically disabled when process record and d6699 1 a6699 1 not all recording methods are available. The ‘full’ recording d6702 1 a6702 1 ‘record stop’ d6705 2 a6706 2 the inferior will either be terminated, or will remain in its final state. d6712 2 a6713 2 inferior process will be left in the same state as if the recording never happened. d6719 2 a6720 2 possible to continue the usual "live" debugging of the process from that state. d6725 1 a6725 1 ‘record goto’ d6729 2 a6730 2 ‘record goto begin’ ‘record goto start’ d6733 1 a6733 1 ‘record goto end’ d6736 1 a6736 1 ‘record goto N’ d6739 3 a6741 3 ‘record save FILENAME’ Save the execution log to a file ‘FILENAME’. Default filename is ‘gdb_record.PROCESS_ID’, where PROCESS_ID is the process ID of the d6746 7 a6752 7 ‘record restore FILENAME’ Restore the execution log from a file ‘FILENAME’. File must have been created with ‘record save’. ‘set record full insn-number-max LIMIT’ ‘set record full insn-number-max unlimited’ Set the limit of instructions to be recorded for the ‘full’ d6762 1 a6762 1 ‘stop-at-limit’ option, described below.) d6764 1 a6764 1 If LIMIT is ‘unlimited’ or zero, GDB will never delete recorded d6768 2 a6769 2 ‘show record full insn-number-max’ Show the limit of instructions to be recorded with the ‘full’ d6772 8 a6779 8 ‘set record full stop-at-limit’ Control the behavior of the ‘full’ recording method when the number of recorded instructions reaches the limit. If ON (the default), GDB will stop when the limit is reached for the first time and ask you whether you want to stop the inferior or continue running it and recording the execution log. If you decide to continue recording, each new recorded instruction will cause the oldest one to be deleted. d6784 2 a6785 2 ‘show record full stop-at-limit’ Show the current setting of ‘stop-at-limit’. d6787 1 a6787 1 ‘set record full memory-query’ d6789 1 a6789 1 caused by an instruction for the ‘full’ recording method. If ON, d6793 4 a6796 3 the effect of such instructions on memory. Later, when GDB replays this execution log, it will mark the log of this instruction as not accessible, and it will not affect the replay results. d6798 2 a6799 2 ‘show record full memory-query’ Show the current setting of ‘memory-query’. d6801 1 a6801 1 The ‘btrace’ record target does not trace data. As a convenience, d6809 7 a6815 7 ‘set record btrace replay-memory-access’ Control the behavior of the ‘btrace’ recording method when accessing memory during replay. If ‘read-only’ (the default), GDB will only allow accesses to read-only memory. If ‘read-write’, GDB will allow accesses to read-only and to read-write memory. Beware that the accessed memory corresponds to the live target and not necessarily to the current replay position. d6817 1 a6817 1 ‘set record btrace cpu IDENTIFIER’ d6823 11 a6833 10 specification. This, in turn, may cause trace decode to fail. GDB can detect erroneous trace packets and correct them, thus avoiding the decoding failures. These corrections are known as “errata workarounds”, and are enabled based on the processor on which the trace was recorded. By default, GDB attempts to detect the processor automatically, and apply the necessary workarounds for it. However, you may need to specify the processor if GDB does not yet support it. This command allows you to do that, and also allows to disable the workarounds. d6836 2 a6837 2 ‘VENDOR:PROCESSOR IDENTIFIER’. In addition, there are two special identifiers, ‘none’ and ‘auto’ (default). d6842 1 a6842 2 ‘intel’ FAMILY/MODEL[/STEPPING] d6844 2 a6845 2 On GNU/Linux systems, the processor FAMILY, MODEL, and STEPPING can be obtained from ‘/proc/cpuinfo’. d6847 1 a6847 1 If IDENTIFIER is ‘auto’, enable errata workarounds for the d6849 1 a6849 1 ‘none’, errata workarounds are disabled. d6851 3 a6853 3 For example, when using an old GDB on a new system, decode may fail because GDB does not support the new processor. It often suffices to specify an older processor that GDB supports. d6867 2 a6868 2 ‘show record btrace replay-memory-access’ Show the current setting of ‘replay-memory-access’. d6870 1 a6870 1 ‘show record btrace cpu’ d6874 2 a6875 2 ‘set record btrace bts buffer-size SIZE’ ‘set record btrace bts buffer-size unlimited’ d6882 2 a6883 2 buffer size may differ from the requested SIZE. Use the ‘info record’ command to see the actual buffer size for each thread that d6886 1 a6886 1 If LIMIT is ‘unlimited’ or zero, GDB will try to allocate a buffer d6893 1 a6893 1 ‘show record btrace bts buffer-size SIZE’ d6897 2 a6898 2 ‘set record btrace pt buffer-size SIZE’ ‘set record btrace pt buffer-size unlimited’ d6906 1 a6906 1 Use the ‘info record’ command to see the actual buffer size for d6909 1 a6909 1 If LIMIT is ‘unlimited’ or zero, GDB will try to allocate a buffer d6916 1 a6916 1 ‘show record btrace pt buffer-size SIZE’ d6920 1 a6920 1 ‘info record’ d6924 2 a6925 2 ‘full’ For the ‘full’ recording method, it shows the state of process d6928 3 a6930 2 • Whether in record mode or replay mode. • Lowest recorded instruction number (counting from when d6933 4 a6936 2 • Highest recorded instruction number. • Current instruction about to be replayed (if in replay d6938 4 a6941 2 • Number of instructions contained in the execution log. • Maximum number of instructions that may be contained in d6944 6 a6949 2 ‘btrace’ For the ‘btrace’ recording method, it shows: d6951 2 a6952 5 • Recording format. • Number of instructions that have been recorded. • Number of blocks of sequential control-flow formed by the recorded instructions. • Whether in record mode or replay mode. d6954 1 a6954 2 For the ‘bts’ recording format, it also shows: • Size of the perf ring buffer. d6956 2 a6957 2 For the ‘pt’ recording format, it also shows: • Size of the perf ring buffer. d6959 4 a6962 1 ‘record delete’ d6965 3 a6967 2 starting from the current address. This means you will abandon the previously recorded "future" and begin recording a new "future". d6969 1 a6969 1 ‘record instruction-history’ d6972 1 a6972 1 using the ‘set record instruction-history-size’ command. d6976 4 a6979 4 ‘/m’ or ‘/s’ modifier, and print the raw instructions in hex as well as in symbolic form by specifying the ‘/r’ or ‘/b’ modifier. The behaviour of the ‘/m’, ‘/s’, ‘/r’, and ‘/b’ modifiers are the same as for the ‘disassemble’ command (*note ‘disassemble’: d6984 3 a6986 3 multiple times in the trace and the current position marker will be printed every time. To omit the current position marker, specify the ‘/p’ modifier. d6990 1 a6990 1 omitted by specifying the ‘/f’ modifier. d6992 1 a6992 1 Speculatively executed instructions are prefixed with ‘?’. This d6998 1 a6998 1 ‘record instruction-history INSN’ d7002 1 a7002 1 ‘record instruction-history INSN, +/-N’ d7004 2 a7005 2 If N is preceded with ‘+’, disassembles N instructions after instruction number INSN. If N is preceded with ‘-’, d7008 1 a7008 1 ‘record instruction-history’ d7011 1 a7011 1 ‘record instruction-history -’ d7015 1 a7015 1 ‘record instruction-history BEGIN, END’ d7022 9 a7030 9 ‘set record instruction-history-size SIZE’ ‘set record instruction-history-size unlimited’ Define how many instructions to disassemble in the ‘record instruction-history’ command. The default value is 10. A SIZE of ‘unlimited’ means unlimited instructions. ‘show record instruction-history-size’ Show how many instructions to disassemble in the ‘record instruction-history’ command. d7032 1 a7032 1 ‘record function-call-history’ d7036 5 a7040 5 instruction sequence (if the ‘/l’ modifier is specified), and the instructions numbers that form the sequence (if the ‘/i’ modifier is specified). The function names are indented to reflect the call stack depth if the ‘/c’ modifier is specified. The ‘/l’, ‘/i’, and ‘/c’ modifiers can be given together. d7059 1 a7059 1 the ‘set record function-call-history-size’ command. Functions are d7063 1 a7063 1 ‘record function-call-history FUNC’ d7066 1 a7066 1 ‘record function-call-history FUNC, +/-N’ d7068 2 a7069 2 preceded with ‘+’, prints N functions after function number FUNC. If N is preceded with ‘-’, prints N functions before d7072 1 a7072 1 ‘record function-call-history’ d7075 1 a7075 1 ‘record function-call-history -’ d7078 1 a7078 1 ‘record function-call-history BEGIN, END’ d7084 9 a7092 9 ‘set record function-call-history-size SIZE’ ‘set record function-call-history-size unlimited’ Define how many functions to print in the ‘record function-call-history’ command. The default value is 10. A size of ‘unlimited’ means unlimited functions. ‘show record function-call-history-size’ Show how many functions to print in the ‘record function-call-history’ command. d7100 2 a7101 2 When your program has stopped, the first thing you need to know is where it stopped and how it got there. d7105 4 a7108 4 call in your program, the arguments of the call, and the local variables of the function being called. The information is saved in a block of data called a “stack frame”. The stack frames are allocated in a region of memory called the “call stack”. d7113 6 a7118 5 One of the stack frames is “selected” by GDB and many GDB commands refer implicitly to the selected frame. In particular, whenever you ask GDB for the value of a variable in your program, the value is found in the selected frame. There are special GDB commands to select whichever frame you are interested in. *Note Selecting a Frame: Selection. d7121 2 a7122 2 executing frame and describes it briefly, similar to the ‘frame’ command (*note Information about a Frame: Frame Info.). d7139 5 a7143 5 The call stack is divided up into contiguous pieces called “stack frames”, or “frames” for short; each frame is the data associated with one call to one function. The frame contains the arguments given to the function, the function's local variables, and the address at which the function is executing. d7146 7 a7152 7 the function ‘main’. This is called the “initial” frame or the “outermost” frame. Each time a function is called, a new frame is made. Each time a function returns, the frame for that function invocation is eliminated. If a function is recursive, there can be many frames for the same function. The frame for the function in which execution is actually occurring is called the “innermost” frame. This is the most recently created of all the stack frames that still exist. d7155 4 a7158 4 A stack frame consists of many bytes, each of which has its own address; each kind of computer has a convention for choosing one byte whose address serves as the address of the frame. Usually this address is kept in a register called the “frame pointer register” (*note $fp: d7161 4 a7164 4 GDB labels each existing stack frame with a “level”, a number that is zero for the innermost frame, one for the frame that called it, and so on upward. These level numbers give you a way of designating stack frames in GDB commands. The terms “frame number” and “frame level” can d7169 5 a7173 5 ‘-fomit-frame-pointer’ generates functions without a frame.) This is occasionally done with heavily used library functions to save the frame setup time. GDB has limited facilities for dealing with these function invocations. If the innermost function invocation has no stack frame, GDB nevertheless d7186 2 a7187 2 executing frame (frame zero), followed by its caller (frame one), and on up the stack. d7189 5 a7193 5 To print a backtrace of the entire stack, use the ‘backtrace’ command, or its alias ‘bt’. This command will print one line per frame for frames in the stack. By default, all stack frames are printed. You can stop the backtrace at any time by typing the system interrupt character, normally ‘Ctrl-c’. d7195 2 a7196 2 ‘backtrace [OPTION]... [QUALIFIER]... [COUNT]’ ‘bt [OPTION]... [QUALIFIER]... [COUNT]’ d7201 2 a7202 2 ‘N’ ‘N’ d7206 2 a7207 2 ‘-N’ ‘-N’ d7213 1 a7213 1 ‘-full’ d7215 2 a7216 2 combined with the optional COUNT to limit the number of frames shown. d7218 1 a7218 1 ‘-no-filters’ d7221 1 a7221 1 *note disable frame-filter all:: to turn off all frame d7223 1 a7223 1 with ‘Python’ support. d7225 1 a7225 1 ‘-hide’ d7228 2 a7229 2 indented relative to the filtered frames that cause them to be elided. The ‘-hide’ option causes elided frames to not be d7232 16 a7247 15 The ‘backtrace’ command also supports a number of options that allow overriding relevant global print settings as set by ‘set backtrace’ and ‘set print’ subcommands: ‘-past-main [on|off]’ Set whether backtraces should continue past ‘main’. Related setting: *note set backtrace past-main::. ‘-past-entry [on|off]’ Set whether backtraces should continue past the entry point of a program. Related setting: *note set backtrace past-entry::. ‘-entry-values no|only|preferred|if-needed|both|compact|default’ Set printing of function arguments at function entry. Related setting: *note set print entry-values::. d7249 1 a7249 1 ‘-frame-arguments all|scalars|none’ d7251 1 a7251 1 *note set print frame-arguments::. d7253 1 a7253 1 ‘-raw-frame-arguments [on|off]’ d7255 1 a7255 1 setting: *note set print raw-frame-arguments::. d7257 3 a7259 3 ‘-frame-info auto|source-line|location|source-and-location|location-and-address|short-location’ Set printing of frame information. Related setting: *note set print frame-info::. d7264 5 a7268 2 ‘full’ Equivalent to the ‘-full’ option. d7270 2 a7271 2 ‘no-filters’ Equivalent to the ‘-no-filters’ option. a7272 2 ‘hide’ Equivalent to the ‘-hide’ option. d7274 2 a7275 2 The names ‘where’ and ‘info stack’ (abbreviated ‘info s’) are additional aliases for ‘backtrace’. d7279 2 a7280 2 the threads, use the command ‘thread apply’ (*note thread apply: Threads.). For example, if you type ‘thread apply all backtrace’, GDB d7285 2 a7286 2 name. The program counter value is also shown--unless you use ‘set print address off’. The backtrace also shows the source file name and d7291 2 a7292 2 Here is an example of a backtrace. It was made with the command ‘bt 3’, so it shows the innermost three frames. d7303 1 a7303 1 for line ‘993’ of ‘builtin.c’. d7305 4 a7308 4 The value of parameter ‘data’ in frame 1 has been replaced by ‘...’. By default, GDB prints the value of a parameter only if it is a scalar (integer, pointer, enumeration, etc). See command ‘set print frame-arguments’ in *note Print Settings:: for more details on how to d7310 1 a7310 1 ‘set print frame-info’ (*note Print Settings::) controls what frame d7314 6 a7319 6 optimize away arguments passed to functions if those arguments are never used after the call. Such optimizations generate code that passes arguments through registers, but doesn't store those arguments in the stack frame. GDB has no way of displaying such arguments in stack frames other than the innermost one. Here's what such a backtrace might look like: d7329 1 a7329 1 shown as ‘’. d7337 1 a7337 1 ‘main’(1). When GDB finds the entry function in a backtrace it will d7344 2 a7345 2 ‘set backtrace past-main’ ‘set backtrace past-main on’ d7348 1 a7348 1 ‘set backtrace past-main off’ d7352 1 a7352 1 ‘show backtrace past-main’ d7355 2 a7356 2 ‘set backtrace past-entry’ ‘set backtrace past-entry on’ d7360 1 a7360 1 ‘main’ (or equivalent) is called. d7362 1 a7362 1 ‘set backtrace past-entry off’ d7366 1 a7366 1 ‘show backtrace past-entry’ d7369 4 a7372 4 ‘set backtrace limit N’ ‘set backtrace limit 0’ ‘set backtrace limit unlimited’ Limit the backtrace to N levels. A value of ‘unlimited’ or zero d7375 1 a7375 1 ‘show backtrace limit’ d7380 2 a7381 2 ‘set filename-display’ ‘set filename-display relative’ d7385 1 a7385 1 ‘set filename-display basename’ d7388 1 a7388 1 ‘set filename-display absolute’ d7391 1 a7391 1 ‘show filename-display’ d7397 1 a7397 1 environment) are not required to have a ‘main’ function as the entry d7411 4 a7414 3 ‘frame [ FRAME-SELECTION-SPEC ]’ ‘f [ FRAME-SELECTION-SPEC ]’ The ‘frame’ command allows different stack frames to be selected. d7417 3 a7419 2 ‘NUM’ ‘level NUM’ d7423 1 a7423 1 frame is usually the one for ‘main’. d7426 1 a7426 1 stack, the string ‘level’ can be omitted. For example, the d7432 1 a7432 1 ‘address STACK-ADDRESS’ d7434 2 a7435 2 STACK-ADDRESS for a frame can be seen in the output of ‘info frame’, for example: d7445 1 a7445 1 The STACK-ADDRESS for this frame is ‘0x7fffffffda30’ as d7450 1 a7450 1 ‘function FUNCTION-NAME’ d7455 1 a7455 1 ‘view STACK-ADDRESS [ PC-ADDR ]’ d7467 1 a7467 1 ‘frame view’ then you can always return to the original stack d7469 1 a7469 1 for example ‘frame level 0’. d7471 2 a7472 1 ‘up N’ d7477 1 a7477 1 ‘down N’ d7479 3 a7481 3 numbers N, this advances toward the innermost frame, to lower frame numbers, to frames that were created more recently. You may abbreviate ‘down’ as ‘do’. d7495 17 a7511 17 After such a printout, the ‘list’ command with no arguments prints ten lines centered on the point of execution in the frame. You can also edit the program at the point of execution with your favorite editing program by typing ‘edit’. *Note Printing Source Lines: List, for details. ‘select-frame [ FRAME-SELECTION-SPEC ]’ The ‘select-frame’ command is a variant of ‘frame’ that does not display the new frame after selecting it. This command is intended primarily for use in GDB command scripts, where the output might be unnecessary and distracting. The FRAME-SELECTION-SPEC is as for the ‘frame’ command described in *note Selecting a Frame: Selection. ‘up-silently N’ ‘down-silently N’ These two commands are variants of ‘up’ and ‘down’, respectively; d7526 2 a7527 2 ‘frame’ ‘f’ d7530 1 a7530 1 selected stack frame. It can be abbreviated ‘f’. With an d7534 2 a7535 2 ‘info frame’ ‘info f’ d7539 7 a7545 4 • the address of the frame • the address of the next frame down (called by this frame) • the address of the next frame up (caller of this frame) • the language in which the source code corresponding to this d7547 6 a7552 3 • the address of the frame's arguments • the address of the frame's local variables • the program counter saved in it (the address of execution in d7554 2 a7555 1 • which registers were saved in the frame d7560 2 a7561 2 ‘info frame [ FRAME-SELECTION-SPEC ]’ ‘info f [ FRAME-SELECTION-SPEC ]’ d7564 1 a7564 1 the ‘frame’ command (*note Selecting a Frame: Selection.). The d7567 1 a7567 1 ‘info args [-q]’ d7570 3 a7572 3 The optional flag ‘-q’, which stands for ‘quiet’, disables printing header information and messages explaining why no argument have been printed. d7574 2 a7575 2 ‘info args [-q] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info args’, but only print the arguments selected with the d7582 1 a7582 1 as printed by the ‘whatis’ command, match the regular expression d7587 3 a7589 2 If both REGEXP and TYPE_REGEXP are provided, an argument is printed only if its name matches REGEXP and its type matches TYPE_REGEXP. d7591 1 a7591 1 ‘info locals [-q]’ d7597 3 a7599 3 The optional flag ‘-q’, which stands for ‘quiet’, disables printing header information and messages explaining why no local variables have been printed. d7601 2 a7602 2 ‘info locals [-q] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info locals’, but only print the local variables selected d7609 1 a7609 1 types, as printed by the ‘whatis’ command, match the regular d7618 2 a7619 2 The command ‘info locals -q -t TYPE_REGEXP’ can usefully be combined with the commands ‘frame apply’ and ‘thread apply’. For d7621 2 a7622 2 Initialization types (RAII) such as ‘lock_something_t’: each local variable of type ‘lock_something_t’ automatically places a lock d7629 1 d7636 2 a7637 2 ‘frame apply [all | COUNT | -COUNT | level LEVEL...] [OPTION]... COMMAND’ The ‘frame apply’ command allows you to apply the named COMMAND to d7640 2 a7641 2 ‘all’ Specify ‘all’ to apply COMMAND to all frames. d7643 1 a7643 1 ‘COUNT’ d7647 1 a7647 1 ‘-COUNT’ d7651 2 a7652 2 ‘level’ Use ‘level’ to apply COMMAND to the set of frames identified d7655 2 a7656 2 in the first field of the ‘backtrace’ command output. E.g., ‘2-4 6-8 3’ indicates to apply COMMAND for the frames at d7659 4 a7662 3 Note that the frames on which ‘frame apply’ applies a command are also influenced by the ‘set backtrace’ settings such as ‘set backtrace past-main’ and ‘set backtrace limit N’. *Note d7665 2 a7666 2 The ‘frame apply’ command also supports a number of options that allow overriding relevant ‘set backtrace’ settings: d7668 3 a7670 3 ‘-past-main [on|off]’ Whether backtraces should continue past ‘main’. Related setting: *note set backtrace past-main::. d7672 1 a7672 1 ‘-past-entry [on|off]’ d7674 1 a7674 1 program. Related setting: *note set backtrace past-entry::. d7678 1 a7678 1 COMMAND will abort ‘frame apply’. The following options can be d7681 8 a7688 7 ‘-c’ The flag ‘-c’, which stands for ‘continue’, causes any errors in COMMAND to be displayed, and the execution of ‘frame apply’ then continues. ‘-s’ The flag ‘-s’, which stands for ‘silent’, causes any errors or empty output produced by a COMMAND to be silently ignored. d7691 3 a7693 2 ‘-q’ The flag ‘-q’ (‘quiet’) disables printing the frame d7696 4 a7699 3 The following example shows how the flags ‘-c’ and ‘-s’ are working when applying the command ‘p j’ to all frames, where variable ‘j’ can only be successfully printed in the outermost ‘#1 main’ frame. d7714 1 a7714 1 By default, ‘frame apply’, prints the frame location information d7724 1 a7724 1 If the flag ‘-q’ is given, no frame information is printed: d7730 3 a7732 2 ‘faas COMMAND’ Shortcut for ‘frame apply all -s COMMAND’. Applies COMMAND on all d7740 1 a7740 1 The ‘faas’ command accepts the same options as the ‘frame apply’ d7743 2 a7744 2 Note that the command ‘tfaas COMMAND’ applies COMMAND on all frames of all threads. See *Note Threads: Threads. d7758 1 a7758 1 ‘info frame-filter’ d7762 9 a7770 9 ‘disable frame-filter FILTER-DICTIONARY FILTER-NAME’ Disable a frame filter in the dictionary matching FILTER-DICTIONARY and FILTER-NAME. The FILTER-DICTIONARY may be ‘all’, ‘global’, ‘progspace’, or the name of the object file where the frame filter dictionary resides. When ‘all’ is specified, all frame filters across all dictionaries are disabled. The FILTER-NAME is the name of the frame filter and is used when ‘all’ is not the option for FILTER-DICTIONARY. A disabled frame-filter is not deleted, it may be enabled again later. d7772 1 a7772 1 ‘enable frame-filter FILTER-DICTIONARY FILTER-NAME’ d7774 3 a7776 3 and FILTER-NAME. The FILTER-DICTIONARY may be ‘all’, ‘global’, ‘progspace’ or the name of the object file where the frame filter dictionary resides. When ‘all’ is specified, all frame filters d7778 1 a7778 1 of the frame filter and is used when ‘all’ is not the option for d7830 1 a7830 1 ‘set frame-filter priority FILTER-DICTIONARY FILTER-NAME PRIORITY’ d7833 1 a7833 1 The FILTER-DICTIONARY may be ‘global’, ‘progspace’ or the name of d7837 1 a7837 1 ‘show frame-filter priority FILTER-DICTIONARY FILTER-NAME’ d7840 1 a7840 1 The FILTER-DICTIONARY may be ‘global’, ‘progspace’ or the name of d7884 9 a7892 9 used to build it. When your program stops, GDB spontaneously prints the line where it stopped. Likewise, when you select a stack frame (*note Selecting a Frame: Selection.), GDB prints the line where execution in that frame has stopped. You can print other portions of source files by explicit command. If you use GDB through its GNU Emacs interface, you may prefer to use Emacs facilities to view source; see *note Using GDB under GNU Emacs: Emacs. d7910 3 a7912 3 To print lines from a source file, use the ‘list’ command (abbreviated ‘l’). By default, ten lines are printed. There are several ways to specify what part of the file you want to print; see *note Location d7915 1 a7915 1 Here are the forms of the ‘list’ command most commonly used: d7917 1 a7917 1 ‘list LINENUM’ d7921 1 a7921 1 ‘list FUNCTION’ d7924 1 a7924 1 ‘list’ d7926 6 a7931 6 ‘list’ command, this prints lines following the last lines printed; however, if the last line printed was a solitary line printed as part of displaying a stack frame (*note Examining the Stack: Stack.), this prints lines centered around that line. If no ‘list’ command has been used and no solitary line was printed, it prints the lines around the function ‘main’. d7933 1 a7933 1 ‘list +’ d7936 1 a7936 1 ‘list -’ d7939 1 a7939 1 ‘list .’ d7945 1 a7945 1 the ‘list’ command. You can change this using ‘set listsize’: d7947 14 a7960 14 ‘set listsize COUNT’ ‘set listsize unlimited’ Make the ‘list’ command display COUNT source lines (unless the ‘list’ argument explicitly specifies some other number). Setting COUNT to ‘unlimited’ or 0 means there's no limit. ‘show listsize’ Display the number of lines that ‘list’ prints. Repeating a ‘list’ command with discards the argument, so it is equivalent to typing just ‘list’. This is more useful than listing the same lines again. An exception is made for an argument of ‘-’; that argument is preserved in repetition so that each repetition moves up in the source file. d7962 2 a7963 2 In general, the ‘list’ command expects you to supply zero, one or two location specs. These location specs are interpreted to resolve to d7968 1 a7968 1 Here is a complete description of the possible arguments for ‘list’: d7970 1 a7970 1 ‘list LOCSPEC’ d7974 8 a7981 8 ‘list FIRST,LAST’ Print lines from FIRST to LAST. Both arguments are location specs. When a ‘list’ command has two location specs, and the source file of the second location spec is omitted, this refers to the same source file as the first location spec. If either FIRST or LAST resolve to more than one source line in the program, then the list command shows the list of resolved source lines and does not proceed with the source code listing. d7983 1 a7983 1 ‘list ,LAST’ d7990 1 a7990 1 ‘list FIRST,’ d7993 1 a7993 1 ‘list +’ d7996 1 a7996 1 ‘list -’ d7999 1 a7999 1 ‘list’ d8010 5 a8014 5 using a source line number, but they can also be specified by a function name, an address, a label, etc. The different forms of specifying a location that GDB recognizes are collectively known as forms of “location specification”, or “location spec”. This section documents the forms of specifying locations that GDB recognizes. d8017 1 a8017 1 program, known as “code location”, that corresponds to the given d8019 1 a8019 1 corresponding to a location spec “location resolution”. d8030 6 a8035 6 source line number to mean a line in the current source file, or specify just the basename of the file, omitting its directories. In other words, a location spec is usually incomplete, a kind of blueprint, and GDB needs to complete the missing attributes by using the implied defaults, and by considering the source code and the debug information available to it. This is what location resolution is about. d8042 1 a8042 1 • The location spec specifies a function name, and there are several d8045 1 a8045 1 function name, such as ‘A::func(int)’ instead of just ‘func’.) d8047 1 a8047 1 • The location spec specifies a source file name, and there are d8053 2 a8054 2 • For a C++ constructor, the GCC compiler generates several instances of the function body, used in different cases, but their d8057 1 a8057 1 • For a C++ template function, a given line in the function can d8060 1 a8060 1 • For an inlined function, a given source line can correspond to d8067 1 a8067 1 • Some parts of the program lack detailed enough debug info, so the d8074 1 a8074 1 • The location spec specifies a function name, and there are no d8078 1 a8078 1 • The location spec specifies a source file name, and there are no d8082 1 a8082 1 • The location spec specifies both a source file name and a source d8103 1 a8103 1 A “linespec” is a colon-separated list of source location parameters d8107 1 a8107 1 ‘LINENUM’ d8110 9 a8118 9 ‘-OFFSET’ ‘+OFFSET’ Specifies the line OFFSET lines before or after the “current line”. For the ‘list’ command, the current line is the last one printed; for the breakpoint commands, this is the line at which execution stopped in the currently selected “stack frame” (*note Frames: Frames, for a description of stack frames.) When used as the second of the two linespecs in a ‘list’ command, this specifies the line OFFSET lines up or down from the first linespec. d8120 1 a8120 1 ‘FILENAME:LINENUM’ d8124 3 a8126 3 FILENAME is ‘gcc/expr.c’, then it will match source file name of ‘/build/trunk/gcc/expr.c’, but not ‘/build/trunk/libcpp/expr.c’ or ‘/build/trunk/gcc/x-expr.c’. d8128 1 a8128 1 ‘FUNCTION’ d8133 7 a8139 6 all functions named FUNCTION in all scopes. For C++, this means in all namespaces and classes. For Ada, this means in all packages. For example, assuming a program with C++ symbols named ‘A::B::func’ and ‘B::func’, both commands ‘break func’ and ‘break B::func’ set a breakpoint on both symbols. d8142 3 a8144 3 ‘-qualified’ option. For example, ‘break -qualified func’ sets a breakpoint on a free-function named ‘func’ ignoring any C++ class methods and namespace functions called ‘func’. d8148 1 a8148 1 ‘FUNCTION:LABEL’ d8151 3 a8153 3 ‘FILENAME:FUNCTION’ Specifies the line that begins the body of the function FUNCTION in the file FILENAME. You only need the file name with a function d8157 1 a8157 1 ‘LABEL’ d8163 2 a8164 2 ‘-pstap|-probe-stap [OBJFILE:[PROVIDER:]]NAME’ The GNU/Linux tool ‘SystemTap’ provides a way for applications to d8169 5 a8173 5 If OBJFILE is given, only probes coming from that shared library or executable matching OBJFILE as a regular expression are considered. If PROVIDER is given, then only probes from that provider are considered. If several probes match the spec, GDB will insert a breakpoint at each one of those probes. d8181 1 a8181 1 “Explicit locations” allow the user to directly specify the source d8184 9 a8192 9 Explicit locations are useful when several functions, labels, or file names have the same name (base name for files) in the program's sources. In these cases, explicit locations point to the source line you meant more accurately and unambiguously. Also, using explicit locations might be faster in large programs. For example, the linespec ‘foo:bar’ may refer to a function ‘bar’ defined in the file named ‘foo’ or the label ‘bar’ in a function named ‘foo’. GDB must search either the file system or the symbol table to d8198 1 a8198 1 ‘-source FILENAME’ d8202 9 a8210 9 ‘foo/bar/baz.c’. Otherwise GDB will use the first file it finds with the given base name. This option requires the use of either ‘-function’ or ‘-line’. ‘-function FUNCTION’ The value specifies the name of a function. Operations on function locations unmodified by other options (such as ‘-label’ or ‘-line’) refer to the line that begins the body of the function. In C, for example, this is the line with the open brace. d8213 3 a8215 2 all functions named FUNCTION in all scopes. For C++, this means in all namespaces and classes. For Ada, this means in all packages. d8217 3 a8219 3 For example, assuming a program with C++ symbols named ‘A::B::func’ and ‘B::func’, both commands ‘break -function func’ and ‘break -function B::func’ set a breakpoint on both symbols. d8221 1 a8221 3 You can use the ‘-qualified’ flag to override this (see below). ‘-qualified’ d8223 1 d8225 1 a8225 1 ‘-function’ as a complete fully-qualified name. d8227 12 a8238 11 For example, assuming a C++ program with symbols named ‘A::B::func’ and ‘B::func’, the ‘break -qualified -function B::func’ command sets a breakpoint on ‘B::func’, only. (Note: the ‘-qualified’ option can precede a linespec as well (*note Linespec Locations::), so the particular example above could be simplified as ‘break -qualified B::func’.) ‘-label LABEL’ The value specifies the name of a label. When the function name is not specified, the label is searched in the function of the d8241 5 a8245 5 ‘-line NUMBER’ The value specifies a line offset for the location. The offset may either be absolute (‘-line 3’) or relative (‘-line +3’), depending on the command. When specified without any other options, the line offset is relative to the current line. d8249 1 a8249 1 ‘break -s main.c -li 3’. d8257 1 a8257 1 “Address locations” indicate a specific program address. They have the d8260 2 a8261 2 For line-oriented commands, such as ‘list’ and ‘edit’, this specifies a source line that contains ADDRESS. For ‘break’ and other d8273 1 a8273 1 ‘EXPRESSION’ d8276 1 a8276 1 ‘FUNCADDR’ d8280 2 a8281 2 valid expression). In Pascal and Modula-2, this is ‘&FUNCTION’. In Ada, this is ‘FUNCTION'Address’ (although the Pascal form also d8287 4 a8290 4 ‘'FILENAME':FUNCADDR’ Like FUNCADDR above, but also specifies the name of the source file explicitly. This is useful if the name of the function does not specify the function unambiguously, e.g., if there are several d8299 5 a8303 5 To edit the lines in a source file, use the ‘edit’ command. The editing program of your choice is invoked with the current line set to the active line in the program. Alternatively, there are several ways to specify what part of the file you want to print if you want to see other parts of the program: d8305 1 a8305 1 ‘edit LOCSPEC’ d8307 2 a8308 2 resolving ‘locspec’. Editing starts at the source file and source line ‘locspec’ resolves to. *Note Location Specifications::, for d8311 3 a8313 3 If ‘locspec’ resolves to more than one source line in your program, then the command prints the list of resolved source lines and does not proceed with the editing. d8315 1 a8315 1 Here are the forms of the ‘edit’ command most commonly used: d8317 1 a8317 1 ‘edit NUMBER’ d8321 1 a8321 1 ‘edit FUNCTION’ d8325 1 d8329 4 a8332 4 You can customize GDB to use any editor you want (1). By default, it is ‘/bin/ex’, but you can change this by setting the environment variable ‘EDITOR’ before using GDB. For example, to configure GDB to use the ‘vi’ editor, you could use these commands with the ‘sh’ shell: d8336 1 a8336 1 or in the ‘csh’ shell, d8342 1 a8342 1 (1) The only restriction is that your editor (say ‘ex’), recognizes d8354 2 a8355 2 There are two commands for searching through the current source file for a regular expression. d8357 12 a8368 12 ‘forward-search REGEXP’ ‘search REGEXP’ The command ‘forward-search REGEXP’ checks each line, starting with the one following the last line listed, for a match for REGEXP. It lists the line that is found. You can use the synonym ‘search REGEXP’ or abbreviate the command name as ‘fo’. ‘reverse-search REGEXP’ The command ‘reverse-search REGEXP’ checks each line, starting with the one before the last line listed and going backward, for a match for REGEXP. It lists the line that is found. You can abbreviate this command as ‘rev’. d8378 6 a8383 5 they do, the directories could be moved between the compilation and your debugging session. GDB has a list of directories to search for source files; this is called the “source path”. Each time GDB wants a source file, it tries all the directories in the list, in the order they are present in the list, until it finds a file with the desired name. d8386 2 a8387 2 ‘/usr/src/foo-1.0/lib/foo.c’, does not record a compilation directory, and the “source path” is ‘/mnt/cross’. GDB would look for the source d8390 6 a8395 3 1. ‘/usr/src/foo-1.0/lib/foo.c’ 2. ‘/mnt/cross/usr/src/foo-1.0/lib/foo.c’ 3. ‘/mnt/cross/foo.c’ d8399 1 a8399 1 name, such as ‘/mnt/cross/src/foo-1.0/lib/foo.c’. Likewise, the d8401 2 a8402 2 is ‘/mnt/cross’, and the binary refers to ‘foo.c’, GDB would not find it under ‘/mnt/cross/usr/src/foo-1.0/lib’. d8407 2 a8408 2 “source path” is ‘/mnt/cross’, the source file is recorded as ‘../lib/foo.c’, and no compilation directory is recorded, then GDB will d8411 8 a8418 2 1. ‘/mnt/cross/../lib/foo.c’ 2. ‘/mnt/cross/foo.c’ d8420 3 a8422 7 The “source path” will always include two special entries ‘$cdir’ and ‘$cwd’, these refer to the compilation directory (if one is recorded) and the current working directory respectively. ‘$cdir’ causes GDB to search within the compilation directory, if one is recorded in the debug information. If no compilation directory is recorded in the debug information then ‘$cdir’ is ignored. d8424 1 a8424 1 ‘$cwd’ is not the same as ‘.’--the former tracks the current working d8430 4 a8433 3 GDB has not found the source file after the first search using “source path”, then GDB will combine the compilation directory and the filename, and then search for the source file again using the “source path”. d8436 25 a8460 15 ‘/usr/src/foo-1.0/lib/foo.c’, the compilation directory is recorded as ‘/project/build’, and the “source path” is ‘/mnt/cross:$cdir:$cwd’ while the current working directory of the GDB session is ‘/home/user’, then GDB will search for the source file in the following locations: 1. ‘/usr/src/foo-1.0/lib/foo.c’ 2. ‘/mnt/cross/usr/src/foo-1.0/lib/foo.c’ 3. ‘/project/build/usr/src/foo-1.0/lib/foo.c’ 4. ‘/home/user/usr/src/foo-1.0/lib/foo.c’ 5. ‘/mnt/cross/project/build/usr/src/foo-1.0/lib/foo.c’ 6. ‘/project/build/project/build/usr/src/foo-1.0/lib/foo.c’ 7. ‘/home/user/project/build/usr/src/foo-1.0/lib/foo.c’ 8. ‘/mnt/cross/foo.c’ 9. ‘/project/build/foo.c’ 10. ‘/home/user/foo.c’ d8468 13 a8480 10 absolute paths start with a drive letter (e.g. ‘C:/project/foo.c’), GDB will remove the drive letter from the file name before appending it to a search directory from “source path”; for instance if the executable references the source file ‘C:/project/foo.c’ and “source path” is set to ‘D:/mnt/cross’, then GDB will search in the following locations for the source file: 1. ‘C:/project/foo.c’ 2. ‘D:/mnt/cross/project/foo.c’ 3. ‘D:/mnt/cross/foo.c’ d8489 3 a8491 2 When you start GDB, its source path includes only ‘$cdir’ and ‘$cwd’, in that order. To add other directories, use the ‘directory’ command. d8494 1 a8494 1 script files (read using the ‘-command’ option and ‘source’ command). d8497 1 a8497 1 manage a list of source path substitution rules. A “substitution rule” d8502 1 a8502 1 and the second specifying how it should be rewritten. In *note set d8504 11 a8514 11 GDB does a simple string replacement of FROM with TO at the start of the directory part of the source file name, and uses that result instead of the original file name to look up the sources. Using the previous example, suppose the ‘foo-1.0’ tree has been moved from ‘/usr/src’ to ‘/mnt/cross’, then you can tell GDB to replace ‘/usr/src’ in all source path names with ‘/mnt/cross’. The first lookup will then be ‘/mnt/cross/foo-1.0/lib/foo.c’ in place of the original location of ‘/usr/src/foo-1.0/lib/foo.c’. To define a source path substitution rule, use the ‘set substitute-path’ command (*note set substitute-path::). d8518 2 a8519 2 instance, a rule substituting ‘/usr/source’ into ‘/mnt/cross’ will be applied to ‘/usr/source/foo-1.0’ but not to ‘/usr/sourceware/foo-2.0’. d8522 1 a8522 1 ‘/root/usr/source/baz.c’ either. d8524 2 a8525 2 In many cases, you can achieve the same result using the ‘directory’ command. However, ‘set substitute-path’ can be more efficient in the d8527 1 a8527 1 subdirectories. With the ‘directory’ command, you need to add each d8529 1 a8529 1 preserving its internal organization, then ‘set substitute-path’ allows d8532 7 a8538 7 ‘set substitute-path’ is also more than just a shortcut command. The source path is only used if the file at the original location no longer exists. On the other hand, ‘set substitute-path’ modifies the debugger behavior to look at the rewritten location instead. So, if for any reason a source file that is not relevant to your executable is located at the original location, a substitution rule is the only method available to point GDB at the new location. d8541 1 a8541 1 configuring GDB with the ‘--with-relocated-sources=DIR’ option. The DIR d8543 1 a8543 1 with ‘--prefix’ or ‘--exec-prefix’), and directory names in debug d8549 3 a8551 2 ‘directory DIRNAME ...’ ‘dir DIRNAME ...’ d8553 12 a8564 11 directory names may be given to this command, separated by ‘:’ (‘;’ on MS-DOS and MS-Windows, where ‘:’ usually appears as part of absolute file names) or whitespace. You may specify a directory that is already in the source path; this moves it forward, so GDB searches it sooner. The special strings ‘$cdir’ (to refer to the compilation directory, if one is recorded), and ‘$cwd’ (to refer to the current working directory) can also be included in the list of directories DIRNAME. Though these will already be in the source path they will be moved forward in the list so GDB searches them sooner. d8566 2 a8567 2 ‘directory’ Reset the source path to its default value (‘$cdir:$cwd’ on Unix d8570 2 a8571 2 ‘set directories PATH-LIST’ Set the source path to PATH-LIST. ‘$cdir:$cwd’ are added if d8574 1 a8574 1 ‘show directories’ d8577 1 a8577 1 ‘set substitute-path FROM TO’ d8583 2 a8584 2 For example, if the file ‘/foo/bar/baz.c’ was moved to ‘/mnt/cross/baz.c’, then the command d8588 2 a8589 2 will tell GDB to replace ‘/foo/bar’ with ‘/mnt/cross’, which will allow GDB to find the file ‘baz.c’ even though it was moved. d8601 4 a8604 4 GDB would then rewrite ‘/usr/src/include/defs.h’ into ‘/mnt/include/defs.h’ by using the first rule. However, it would use the second rule to rewrite ‘/usr/src/lib/foo.c’ into ‘/mnt/src/lib/foo.c’. d8606 1 a8606 1 ‘unset substitute-path [path]’ d8608 3 a8610 3 rules for a rule that would rewrite that path. Delete that rule if found. A warning is emitted by the debugger if no rule could be found. d8614 1 a8614 1 ‘show substitute-path [path]’ d8621 1 d8626 1 a8626 1 1. Use ‘directory’ with no argument to reset the source path to its d8629 1 a8629 1 2. Use ‘directory’ with suitable arguments to reinstall the d8639 2 a8640 2 You can use the command ‘info line’ to map source lines to program addresses (and vice versa), and the command ‘disassemble’ to display a d8642 4 a8645 4 ‘set disassemble-next-line’ to set whether to disassemble next source line when execution stops. When run under GNU Emacs mode, the ‘info line’ command causes the arrow to point to the line specified. Also, ‘info line’ prints addresses in symbolic form as well as hex. d8647 2 a8648 2 ‘info line’ ‘info line LOCSPEC’ d8651 2 a8652 2 LOCSPEC. *Note Location Specifications::, for the various forms of LOCSPEC. With no LOCSPEC, information about the current source d8655 2 a8656 2 For example, we can use ‘info line’ to discover the location of the object code for the first line of function ‘m4_changequote’: d8662 1 a8662 1 We can also inquire, using ‘*ADDR’ as the form for LOCSPEC, what source d8668 5 a8672 5 After ‘info line’, the default address for the ‘x’ command is changed to the starting address of the line, so that ‘x/i’ is sufficient to begin examining the machine code (*note Examining Memory: Memory.). Also, this address is saved as the value of the convenience variable ‘$_’ (*note Convenience Variables: Convenience Vars.). d8674 1 a8674 1 After ‘info line’, using ‘info line’ again without specifying a d8677 5 a8681 5 ‘disassemble’ ‘disassemble /m’ ‘disassemble /s’ ‘disassemble /r’ ‘disassemble /b’ d8684 3 a8686 3 specifying the ‘/m’ or ‘/s’ modifier and print the raw instructions in hex as well as in symbolic form by specifying the ‘/r’ or ‘/b’ modifier. d8688 1 a8688 1 Only one of ‘/m’ and ‘/s’ can be used, attempting to use both flag d8691 1 a8691 1 Only one of ‘/r’ and ‘/b’ can be used, attempting to use both flag d8696 5 a8700 4 is a program counter value; GDB dumps the function surrounding this value. When two arguments are given, they should be separated by a comma, possibly surrounded by whitespace. The arguments specify a range of addresses to dump, in one of two forms: d8702 1 a8702 1 ‘START,END’ d8704 3 a8706 2 ‘START,+LENGTH’ the addresses from START (inclusive) to ‘START+LENGTH’ d8714 1 a8714 1 such as ‘0x32c4’, ‘&main+10’ or ‘$pc - 8’. d8717 1 a8717 1 counter, the instruction at that location is shown with a ‘=>’ d8736 1 a8736 1 difference between the ‘/r’ and ‘/b’ modifiers. First with ‘/b’, the d8747 1 a8747 1 In contrast, with ‘/r’ the bytes of the instruction are displayed in d8760 1 a8760 1 ‘/m’ or ‘/s’, when the program is stopped just after function prologue d8784 2 a8785 2 The ‘/m’ option is deprecated as its output is not useful when there is either inlined code or re-ordered code. The ‘/s’ option is the d8787 1 a8787 1 difference between ‘/m’ output and ‘/s’ output. This example has one d8789 2 a8790 2 ‘-O2’ optimization. Note how the ‘/m’ output is missing the disassembly of several instructions that are present in the ‘/s’ output. d8792 1 a8792 1 ‘foo.h’: d8804 1 a8804 1 ‘foo.c’: d8877 6 a8882 6 Note that the ‘disassemble’ command's address arguments are specified using expressions in your programming language (*note Expressions: Expressions.), not location specs (*note Location Specifications::). So, for example, if you want to disassemble function ‘bar’ in file ‘foo.c’, you must type ‘disassemble 'foo.c'::bar’ and not ‘disassemble foo.c:bar’. d8893 1 a8893 1 ‘set disassembler-options OPTION1[,OPTION2...]’ d8896 2 a8897 2 ‘-M’/‘--disassembler-options’ section of the ‘objdump’ manual and/or the output of ‘objdump --help’ (*note objdump: d8901 3 a8903 3 then multiple options can be placed together into a comma separated list. Currently this command is only supported on targets ARC, ARM, MIPS, PowerPC and S/390. d8905 1 a8905 1 ‘show disassembler-options’ d8908 1 a8908 1 ‘set disassembly-flavor INSTRUCTION-SET’ d8910 1 a8910 1 via the ‘disassemble’ or ‘x/i’ commands. d8913 2 a8914 2 You can set INSTRUCTION-SET to either ‘intel’ or ‘att’. The default is ‘att’, the AT&T flavor used by default by Unix d8917 1 a8917 1 ‘show disassembly-flavor’ d8920 4 a8923 4 ‘set disassemble-next-line’ ‘show disassemble-next-line’ Control whether or not GDB will disassemble the next source line or instruction when execution stops. If ON, GDB will display d8926 2 a8927 2 source line itself, which GDB always does if possible. If the next source line cannot be displayed for some reason (e.g., if GDB d8930 6 a8935 6 instead of showing the next source line. If AUTO, GDB will display disassembly of next instruction only if the source line cannot be displayed. This setting causes GDB to display some feedback when you step through a function with no line info or whose source file is unavailable. The default is OFF, which means never display the disassembly of the next line or instruction. d8950 3 a8952 3 ‘set source open [on|off]’ ‘show source open’ When this option is ‘on’, which is the default, GDB will access d8954 1 a8954 1 when GDB stops, or in response to the ‘list’ command. d8956 1 a8956 1 When this option is ‘off’, GDB will not access source code files. d8964 2 a8965 2 The usual way to examine data in your program is with the ‘print’ command (abbreviated ‘p’), or its synonym ‘inspect’. It evaluates and d8968 2 a8969 2 may also print the expression using a Python-based pretty-printer (*note Pretty Printing::). d8971 2 a8972 2 ‘print [[OPTIONS] --] EXPR’ ‘print [[OPTIONS] --] /F EXPR’ d8975 2 a8976 2 you can choose a different format by specifying ‘/F’, where F is a letter specifying the format; see *note Output Formats: Output d8979 2 a8980 2 The ‘print’ command supports a number of options that allow overriding relevant global print settings as set by ‘set print’ d8983 2 a8984 2 ‘-address [on|off]’ Set printing of addresses. Related setting: *note set print d8987 3 a8989 3 ‘-array [on|off]’ Pretty formatting of arrays. Related setting: *note set print array::. d8991 2 a8992 2 ‘-array-indexes [on|off]’ Set printing of array indexes. Related setting: *note set d8995 2 a8996 2 ‘-characters NUMBER-OF-CHARACTERS|elements|unlimited’ Set limit on string characters to print. The value ‘elements’ d8998 2 a8999 2 value ‘unlimited’ causes there to be no limit. Related setting: *note set print characters::. d9001 1 a9001 1 ‘-elements NUMBER-OF-ELEMENTS|unlimited’ d9003 3 a9005 3 to print. See *note set print characters::, and the ‘-characters’ option above for when this option applies to strings. The value ‘unlimited’ causes there to be no limit. d9008 1 a9008 1 ‘-max-depth DEPTH|unlimited’ d9010 1 a9010 1 with ellipsis. Related setting: *note set print max-depth::. d9012 1 a9012 1 ‘-nibbles [on|off]’ d9016 1 a9016 1 ‘-memory-tag-violations [on|off]’ d9020 1 a9020 1 ‘-null-stop [on|off]’ d9022 1 a9022 1 Related setting: *note set print null-stop::. d9024 1 a9024 1 ‘-object [on|off]’ d9026 1 a9026 1 *note set print object::. d9028 2 a9029 2 ‘-pretty [on|off]’ Set pretty formatting of structures. Related setting: *note d9032 1 a9032 1 ‘-raw-values [on|off]’ d9034 1 a9034 1 pretty-printers for that value. Related setting: *note set d9037 2 a9038 2 ‘-repeats NUMBER-OF-REPEATS|unlimited’ Set threshold for repeated print elements. ‘unlimited’ causes d9040 1 a9040 1 *note set print repeats::. d9042 2 a9043 2 ‘-static-members [on|off]’ Set printing C++ static members. Related setting: *note set d9046 1 a9046 1 ‘-symbol [on|off]’ d9048 1 a9048 1 setting: *note set print symbol::. d9050 1 a9050 1 ‘-union [on|off]’ d9052 1 a9052 1 setting: *note set print union::. d9054 1 a9054 1 ‘-vtbl [on|off]’ d9056 1 a9056 1 *note set print vtbl::. d9058 3 a9060 3 Because the ‘print’ command accepts arbitrary expressions which may look like options (including abbreviations), if you specify any command option, then you must use a double dash (‘--’) to mark the d9063 1 a9063 1 For example, this prints the value of the ‘-p’ expression: d9068 1 a9068 1 with the ‘-pretty’ option in effect: d9084 2 a9085 2 ‘print [OPTIONS]’ ‘print [OPTIONS] /F’ d9087 3 a9089 3 “value history”; *note Value History: Value History.). This allows you to conveniently inspect the same value in an alternative format. d9091 1 a9091 1 If the architecture supports memory tagging, the ‘print’ command will d9093 1 a9093 1 pointer or reference type. *Note Memory Tagging::. d9095 1 a9095 1 A more low-level way of examining data is with the ‘x’ command. It d9100 2 a9101 2 fields of a struct or a class are declared, use the ‘ptype EXPR’ command rather than ‘print’. *Note Examining the Symbol Table: Symbols. d9104 6 a9109 6 is through the Python extension command ‘explore’ (available only if the GDB build is configured with ‘--with-python’). It offers an interactive way to start at the highest level (or, the most abstract level) of the data type of an expression (or, the data type itself) and explore all the way down to leaf scalar values/fields embedded in the higher level data types. d9111 1 a9111 1 ‘explore ARG’ d9115 2 a9116 2 The working of the ‘explore’ command can be illustrated with an example. If a data type ‘struct ComplexStruct’ is defined in your C d9136 2 a9137 2 then, the value of the variable ‘cs’ can be explored using the ‘explore’ command as follows. d9148 1 a9148 1 Since the fields of ‘cs’ are not scalar values, you are being prompted d9150 1 a9150 1 ‘ss_p’ by entering ‘0’. Then, since this field is a pointer, you will d9152 4 a9155 4 ‘cs’ above, it is indeed pointing to a single value, hence you enter ‘y’. If you enter ‘n’, then you will be asked if it were pointing to an array of values, in which case this field will be explored as if it were an array. d9167 1 a9167 1 If the field ‘arr’ of ‘cs’ was chosen for exploration by entering ‘1’ d9185 1 a9185 1 Similar to exploring values, you can use the ‘explore’ command to d9189 2 a9190 2 same example as above, your can explore the type ‘struct ComplexStruct’ by passing the argument ‘struct ComplexStruct’ to the ‘explore’ command. d9195 2 a9196 2 session, you can explore the type ‘struct ComplexStruct’ in a manner similar to how the value ‘cs’ was explored in the above example. d9198 2 a9199 2 The ‘explore’ command also has two sub-commands, ‘explore value’ and ‘explore type’. The former sub-command is a way to explicitly specify d9204 2 a9205 2 ‘explore value EXPR’ This sub-command of ‘explore’ explores the value of the expression d9207 14 a9220 14 program being debugged). The behavior of this command is identical to that of the behavior of the ‘explore’ command being passed the argument EXPR. ‘explore type ARG’ This sub-command of ‘explore’ explores the type of ARG (if ARG is a type visible in the current context of program being debugged), or the type of the value/expression ARG (if ARG is an expression valid in the current context of the program being debugged). If ARG is a type, then the behavior of this command is identical to that of the ‘explore’ command being passed the argument ARG. If ARG is an expression, then the behavior of this command will be identical to that of the ‘explore’ command being passed the type of ARG as the argument. d9256 2 a9257 2 ‘print’ and many other GDB commands accept an expression and compute its value. Any kind of constant, variable or operator defined by the d9259 4 a9262 3 This includes conditional expressions, function calls, casts, and string constants. It also includes preprocessor macros, if you compiled your program to include this information; see *note Compilation::. d9266 1 a9266 1 ‘print {1, 2, 3}’ to create an array of three integers. If you pass an d9268 1 a9268 1 array to memory that is ‘malloc’ed in the target program. d9270 4 a9273 3 Because C is so widespread, most of the expressions shown in examples in this manual are in C. *Note Using GDB with Different Languages: Languages, for information on how to use expressions in other languages. d9285 2 a9286 2 ‘@@’ ‘@@’ is a binary operator for treating parts of memory as arrays. d9289 2 a9290 2 ‘::’ ‘::’ allows you to specify a variable in terms of the file or d9293 1 a9293 1 ‘{TYPE} ADDR’ d9295 4 a9298 4 The address ADDR may be any expression whose value is an integer or pointer (but parentheses are required around binary operators, just as in a cast). This construct is allowed regardless of what kind of data is normally supposed to reside at ADDR. d9309 2 a9310 2 application in different contexts. This is called “overloading”. Another example involving Ada is generics. A “generic package” is d9316 3 a9318 3 specify the signature of the function you want to break on, as in ‘break FUNCTION(TYPES)’. In Ada, using the fully qualified name of your function often makes the expression unambiguous as well. d9322 5 a9326 5 possibility, and then waits for the selection with the prompt ‘>’. The first option is always ‘[0] cancel’, and typing ‘0 ’ aborts the current command. If the command in which the expression was used allows more than one choice to be selected, the next option in the menu is ‘[1] all’, and typing ‘1 ’ selects all possible choices. d9329 1 a9329 1 breakpoint at the overloaded symbol ‘String::after’. We choose three d9350 1 a9350 2 ‘set multiple-symbols MODE’ d9354 1 a9354 1 By default, MODE is set to ‘all’. If the command with which the d9359 4 a9362 3 if a unique choice must be made, then GDB uses the menu to help you disambiguate the expression. For instance, printing the address of an overloaded function will result in the use of the menu. d9364 1 a9364 1 When MODE is set to ‘ask’, the debugger always uses the menu when d9367 1 a9367 1 Finally, when MODE is set to ‘cancel’, the debugger reports an d9370 2 a9371 2 ‘show multiple-symbols’ Show the current value of the ‘multiple-symbols’ setting. d9385 1 a9385 1 • global (or file-static) d9389 1 a9389 1 • visible according to the scope rules of the programming language d9404 4 a9407 4 you can examine and use the variable ‘a’ whenever your program is executing within the function ‘foo’, but you can only use or examine the variable ‘b’ while your program is executing inside the block where ‘b’ is declared. d9415 1 a9415 1 using the colon-colon (‘::’) notation: d9423 1 a9423 1 global value of ‘x’ defined in ‘f2.c’: d9427 5 a9431 5 The ‘::’ notation is normally used for referring to static variables, since you typically disambiguate uses of local variables in functions by selecting the appropriate frame and using the simple name of the variable. However, you may also use this notation to refer to local variables in frames enclosing the selected frame: d9450 1 a9450 1 ‘bar(0)’: d9463 1 a9463 1 These uses of ‘::’ are very rarely in conflict with the very similar d9465 2 a9466 2 meaning takes precedence; however, this can be overridden by quoting the file or function name with single quotes. d9469 2 a9470 2 that has a field named ‘includefile’, and there is also an include file named ‘includefile’ that defines a variable, ‘some_global’. d9483 7 a9489 7 instructions. This is because, on most machines, it takes more than one instruction to set up a stack frame (including local variable definitions); if you are stepping by machine instructions, variables may appear to have the wrong values until the stack frame is completely built. On exit, it usually also takes more than one machine instruction to destroy a stack frame; after you begin stepping through that group of instructions, local variable definitions may be gone. d9512 1 a9512 1 information, GDB will say ‘’. *Note incomplete type: d9516 5 a9520 5 which GDB has no type information, e.g., because the program includes no debug information, GDB displays an error message. *Note unknown type: Symbols, for more about unknown types. If you cast the variable to its declared type, GDB gets the variable's value using the cast-to type as the variable's type. For example, in a C program: d9527 1 a9527 1 If you append ‘@@entry’ string to a function parameter name you get d9531 1 a9531 1 function parameter list according to *note set print entry-values::. d9542 5 a9546 5 Strings are identified as arrays of ‘char’ values without specified signedness. Arrays of either ‘signed char’ or ‘unsigned char’ get printed as arrays of 1 byte sized integers. ‘-fsigned-char’ or ‘-funsigned-char’ GCC options have no effect as GDB defines literal string type ‘"char"’ as ‘char’ without a sign. For program code d9568 2 a9569 2 “artificial array”, using the binary operator ‘@@’. The left operand of ‘@@’ should be the first element of the desired array and be an d9579 1 a9579 1 you can print the contents of ‘array’ with d9583 2 a9584 2 The left operand of ‘@@’ must reside in memory. Array values made with ‘@@’ in this way behave just like other arrays in terms of d9596 2 a9597 2 ‘(TYPE[])VALUE’) GDB calculates the size to fill the value (as ‘sizeof(VALUE)/sizeof(TYPE)’: d9604 2 a9605 2 of pointers in an array. One useful work-around in this situation is to use a convenience variable (*note Convenience Variables: Convenience d9607 3 a9609 3 value, and then repeat that expression via . For instance, suppose you have an array ‘dtab’ of pointers to structures, and you are interested in the values of a field ‘fv’ in each structure. Here is an d9628 1 a9628 1 instruction. To do these things, specify an “output format” when you d9632 3 a9634 3 already computed. This is done by starting the arguments of the ‘print’ command with a slash and a format letter. The format letters supported are: d9636 1 a9636 1 ‘x’ d9639 1 a9639 1 ‘d’ d9642 1 a9642 1 ‘u’ d9646 1 a9646 1 ‘o’ d9649 1 a9649 1 ‘t’ d9651 1 a9651 1 ‘t’ stands for "two". (1) d9653 1 a9653 1 ‘a’ d9655 2 a9656 2 from the nearest preceding symbol. You can use this format used to discover where (in what function) an unknown address is located: d9661 1 a9661 1 The command ‘info symbol 0x54320’ yields similar results. *Note d9664 1 a9664 1 ‘c’ d9669 1 a9669 1 octal escape ‘\nnn’ for characters outside the 7-bit ASCII range. d9671 2 a9672 2 Without this format, GDB displays ‘char’, ‘unsigned char’, and ‘signed char’ data as character constants. Single-byte members of d9675 1 a9675 1 ‘f’ d9679 1 a9679 1 ‘s’ d9685 8 a9692 8 Without this format, GDB displays pointers to and arrays of ‘char’, ‘unsigned char’, and ‘signed char’ as strings. Single-byte members of a vector are displayed as an integer array. ‘z’ Like ‘x’ formatting, the value is treated as an integer and printed as hexadecimal, but leading zeros are printed to pad the value to the size of the integer type. d9694 2 a9695 2 ‘r’ Print using the ‘raw’ formatting. By default, GDB will use a d9698 1 a9698 1 the value's contents. The ‘r’ format bypasses any Python d9701 2 a9702 2 For example, to print the program counter in hex (*note Registers::), type d9710 2 a9711 2 format, you can use the ‘print’ command with just a format and no expression. For example, ‘p/x’ reprints the last value in hex. d9715 2 a9716 2 (1) ‘b’ cannot be used because these format letters are also used with the ‘x’ command, where ‘b’ stands for "byte"; see *note Examining d9725 1 a9725 1 You can use the command ‘x’ (for "examine") to examine memory in any of d9728 4 a9731 4 ‘x/NFU ADDR’ ‘x ADDR’ ‘x’ Use the ‘x’ command to examine memory. d9736 1 a9736 1 for NFU, you need not type the slash ‘/’. Several commands set d9746 5 a9750 5 The display format is one of the formats used by ‘print’ (‘x’, ‘d’, ‘u’, ‘o’, ‘t’, ‘a’, ‘c’, ‘f’, ‘s’), ‘i’ (for machine instructions) and ‘m’ (for displaying memory tags). The default is ‘x’ (hexadecimal) initially. The default changes each time you use either ‘x’ or ‘print’. d9755 1 a9755 1 ‘b’ d9757 2 a9758 1 ‘h’ d9760 2 a9761 1 ‘w’ d9763 2 a9764 1 ‘g’ d9767 6 a9772 6 Each time you specify a unit size with ‘x’, that size becomes the default unit the next time you use ‘x’. For the ‘i’ format, the unit size is ignored and is normally not written. For the ‘s’ format, the unit size defaults to ‘b’, unless it is explicitly given. Use ‘x /hs’ to display 16-bit char strings and ‘x /ws’ to display 32-bit strings. The next use of ‘x /s’ will again display d9775 1 a9775 1 the ‘s’ modifier will use the UTF-16 encoding while ‘w’ will use d9781 2 a9782 2 The expression need not have a pointer value (though it may); it is always interpreted as an integer address of a byte of memory. d9786 9 a9794 9 address: ‘info breakpoints’ (to the address of the last breakpoint listed), ‘info line’ (to the starting address of a line), and ‘print’ (if you use it to display a value from memory). For example, ‘x/3uh 0x54320’ is a request to display three halfwords (‘h’) of memory, formatted as unsigned decimal integers (‘u’), starting at address ‘0x54320’. ‘x/4xw $sp’ prints the four words (‘w’) of memory above the stack pointer (here, ‘$sp’; *note Registers: Registers.) in hexadecimal (‘x’). d9797 2 a9798 2 backward from the given address. For example, ‘x/-3uh 0x54320’ prints three halfwords (‘h’) at ‘0x5431a’, ‘0x5431c’, and ‘0x5431e’. d9803 2 a9804 2 specifications ‘4xw’ and ‘4wx’ mean exactly the same thing. (However, the count N must come first; ‘wx4’ does not work.) d9806 9 a9814 9 Even though the unit size U is ignored for the formats ‘s’ and ‘i’, you might still want to use a count N; for example, ‘3i’ specifies that you want to see three machine instructions, including any operands. For convenience, especially when used with the ‘display’ command, the ‘i’ format also prints branch delay slot instructions, if any, beyond the count specified, which immediately follow the last instruction that is within the count. The command ‘disassemble’ gives an alternative way of inspecting machine instructions; see *note Source and Machine Code: Machine Code. d9816 1 a9816 1 If a negative repeat count is specified for the formats ‘s’ or ‘i’, d9819 1 a9819 1 the ‘i’ format, we use line number information in the debug info to d9824 1 a9824 1 All the defaults for the arguments to ‘x’ are designed to make it d9826 3 a9828 3 you use ‘x’. For example, after you have inspected three machine instructions with ‘x/3i ADDR’, you can inspect the next seven with just ‘x/7’. If you use to repeat the ‘x’ command, the repeat count N d9830 1 a9830 1 ‘x’. d9833 1 a9833 1 program counter is shown with a ‘=>’ marker. For example: d9843 1 a9843 1 displayed by using ‘m’. *Note Memory Tagging::. d9849 1 a9849 1 Due to the way GDB prints information with the ‘x’ command (not d9852 1 a9852 1 boundary is crossed in the middle of a line displayed by the ‘x’ d9855 2 a9856 2 The ‘m’ format doesn't affect any other specified formats that were passed to the ‘x’ command. d9858 1 a9858 1 The addresses and contents printed by the ‘x’ command are not saved d9862 2 a9863 2 ‘$_’ and ‘$__’. After an ‘x’ command, the last address examined is available for use in expressions in the convenience variable ‘$_’. The d9865 1 a9865 1 variable ‘$__’. d9867 1 a9867 1 If the ‘x’ command has a repeat count, the address and contents saved d9875 1 a9875 1 and this document, the term “addressable memory unit” (or “memory unit” d9877 1 a9877 1 size. The word “byte” is used to refer to a chunk of data of 8 bits, d9886 1 a9886 1 ‘compare-sections’ command is provided for such situations. d9888 1 a9888 1 ‘compare-sections [SECTION-NAME|-r]’ d9890 4 a9893 4 executable file of the program being debugged with the same section in the target machine's memory, and report any mismatches. With no arguments, compares all loadable sections. With an argument of ‘-r’, compares all loadable read-only sections. d9906 3 a9908 2 tags to validate memory accesses through pointers. The tags are integer values usually comprised of a few bits, depending on the architecture. d9911 3 a9913 3 allocation. A logical tag is stored in the pointers themselves, usually at the higher bits of the pointers. An allocation tag is the tag associated with particular ranges of memory in the physical address d9922 1 a9922 1 architecture-specific. For example, AArch64 has a tag granule of 16 d9926 2 a9927 2 MTE or SPARC ADI do, GDB can make use of it to validate pointers against memory allocation tags. d9929 1 a9929 1 The ‘print’ (*note Data::) and ‘x’ (*note Memory::) commands will d9931 3 a9933 1 ‘memory-tag’ gives access to the various memory tagging commands. d9935 2 a9936 1 The ‘memory-tag’ commands are the following: d9938 1 a9938 3 ‘memory-tag print-logical-tag POINTER_EXPRESSION’ Print the logical tag stored in POINTER_EXPRESSION. ‘memory-tag with-logical-tag POINTER_EXPRESSION TAG_BYTES’ d9940 3 a9942 2 logical tag of TAG_BYTES. ‘memory-tag print-allocation-tag ADDRESS_EXPRESSION’ d9944 3 a9946 2 by ADDRESS_EXPRESSION. ‘memory-tag setatag STARTING_ADDRESS LENGTH TAG_BYTES’ d9948 3 a9950 2 STARTING_ADDRESS + LENGTH) to TAG_BYTES. ‘memory-tag check POINTER_EXPRESSION’ d9955 3 a9957 3 This essentially emulates the hardware validation that is done when tagged memory is accessed through a pointer, but does not cause a memory fault as it would during hardware validation. d9969 2 a9970 2 (to see how it changes), you might want to add it to the “automatic display list” so that GDB prints its value each time your program stops. d9979 5 a9983 5 As with displays you request manually using ‘x’ or ‘print’, you can specify the output format you prefer; in fact, ‘display’ decides whether to use ‘print’ or ‘x’ depending your format specification--it uses ‘x’ if you specify either the ‘i’ or ‘s’ format, or a unit size; otherwise it uses ‘print’. d9985 1 a9985 1 ‘display EXPR’ d9989 1 a9989 1 ‘display’ does not repeat if you press again after using it. d9991 1 a9991 1 ‘display/FMT EXPR’ d9997 2 a9998 2 ‘display/FMT ADDR’ For FMT ‘i’ or ‘s’, or including a unit-size or a number of units, d10000 2 a10001 2 time your program stops. Examining means in effect doing ‘x/FMT ADDR’. *Note Examining Memory: Memory. d10003 2 a10004 2 For example, ‘display/i $pc’ can be helpful, to see the machine instruction about to be executed each time execution stops (‘$pc’ is a d10007 2 a10008 2 ‘undisplay DNUMS...’ ‘delete display DNUMS...’ d10012 2 a10013 2 numbers shown in the first field of the ‘info display’ display; or it could be a range of display numbers, as in ‘2-4’. d10015 2 a10016 2 ‘undisplay’ does not repeat if you press after using it. (Otherwise you would just get the error ‘No display number ...’.) d10018 3 a10020 3 ‘disable display DNUMS...’ Disable the display of item numbers DNUMS. A disabled display item is not printed automatically, but is not forgotten. It may be d10024 2 a10025 2 ‘info display’ display; or it could be a range of display numbers, as in ‘2-4’. d10027 1 a10027 1 ‘enable display DNUMS...’ d10033 2 a10034 2 ‘info display’ display; or it could be a range of display numbers, as in ‘2-4’. d10036 1 a10036 1 ‘display’ d10040 1 a10040 1 ‘info display’ d10044 3 a10046 3 as such. It also includes expressions which would not be displayed right now because they refer to automatic variables not currently available. d10051 7 a10057 7 variables is not defined. For example, if you give the command ‘display last_char’ while inside a function with an argument ‘last_char’, GDB displays this argument while your program continues to stop inside that function. When it stops elsewhere--where there is no variable ‘last_char’--the display is disabled automatically. The next time your program stops where ‘last_char’ is meaningful, you can enable the display expression once again. d10070 2 a10071 2 ‘set print address’ ‘set print address on’ d10075 2 a10076 2 is ‘on’. For example, this is what a stack frame display looks like with ‘set print address on’: d10083 1 a10083 1 ‘set print address off’ d10085 2 a10086 2 example, this is the same stack frame displayed with ‘set print address off’: d10093 1 a10093 1 You can use ‘set print address off’ to eliminate all machine d10095 1 a10095 1 ‘print address off’, you should get the same text for backtraces on d10098 1 a10098 1 ‘show print address’ d10104 4 a10107 3 source file), you may need to clarify. One way to do this is with ‘info line’, for example ‘info line *0x4537’. Alternately, you can set GDB to print the source file and line number when it prints a symbolic address: d10109 1 a10109 1 ‘set print symbol-filename on’ d10113 3 a10115 3 ‘set print symbol-filename off’ Do not print source file name and line number of a symbol. This is the default. d10117 1 a10117 1 ‘show print symbol-filename’ d10128 2 a10129 2 ‘set print max-symbolic-offset MAX-OFFSET’ ‘set print max-symbolic-offset unlimited’ d10132 1 a10132 1 than MAX-OFFSET. The default is ‘unlimited’, which tells GDB to d10134 1 a10134 1 it. Zero is equivalent to ‘unlimited’. d10136 1 a10136 1 ‘show print max-symbolic-offset’ d10140 3 a10142 3 If you have a pointer and you are not sure where it points, try ‘set print symbol-filename on’. Then you can determine the name and source file location of the variable where it points, using ‘p/a POINTER’. d10144 2 a10145 2 shows that a variable ‘ptt’ points at another variable ‘t’, defined in ‘hi2.c’: d10151 1 a10151 1 _Warning:_ For pointers that point to a local variable, ‘p/a’ does d10153 1 a10153 1 the appropriate ‘set print’ options turned on. d10155 2 a10156 2 You can also enable ‘/a’-like formatting all the time using ‘set print symbol on’: d10158 1 a10158 1 ‘set print symbol on’ d10162 1 a10162 1 ‘set print symbol off’ d10167 1 a10167 1 ‘show print symbol’ d10173 2 a10174 2 ‘set print array’ ‘set print array on’ d10178 1 a10178 1 ‘set print array off’ d10181 1 a10181 1 ‘show print array’ d10185 2 a10186 2 ‘set print array-indexes’ ‘set print array-indexes on’ d10192 1 a10192 1 ‘set print array-indexes off’ d10195 1 a10195 1 ‘show print array-indexes’ d10199 5 a10203 5 ‘set print nibbles’ ‘set print nibbles on’ Print binary values in groups of four bits, known as “nibbles”, when using the print command of GDB with the option ‘/t’. For example, this is what it looks like with ‘set print nibbles on’: d10210 1 a10210 1 ‘set print nibbles off’ d10213 1 a10213 1 ‘show print nibbles’ d10216 3 a10218 3 ‘set print characters NUMBER-OF-CHARACTERS’ ‘set print characters elements’ ‘set print characters unlimited’ d10221 1 a10221 1 printed the number of characters set by the ‘set print characters’ d10223 2 a10224 2 strings, that is for strings whose character type is ‘wchar_t’, ‘char16_t’, or ‘char32_t’ it is the number of actual characters d10226 1 a10226 1 controls. Setting NUMBER-OF-CHARACTERS to ‘elements’ means that d10228 2 a10229 2 array elements; see *note set print elements::. Setting NUMBER-OF-CHARACTERS to ‘unlimited’ means that the number of d10231 1 a10231 1 set to ‘elements’. d10233 1 a10233 1 ‘show print characters’ d10237 2 a10238 2 ‘set print elements NUMBER-OF-ELEMENTS’ ‘set print elements unlimited’ d10241 1 a10241 1 printed the number of elements set by the ‘set print elements’ d10243 2 a10244 2 strings; see *note set print characters::. When GDB starts, this limit is set to 200. Setting NUMBER-OF-ELEMENTS to ‘unlimited’ or d10248 6 a10253 6 ‘max-value-size’ (*note max-value-size: set max-value-size.), if the ‘print elements’ is set such that the size of the elements being printed is less than or equal to ‘max-value-size’, then GDB will print the array (up to the ‘print elements’ limit), and only ‘max-value-size’ worth of data will be added into the value history (*note Value History: Value History.). d10255 1 a10255 1 ‘show print elements’ d10259 1 a10259 1 ‘set print frame-arguments VALUE’ d10264 1 a10264 1 ‘all’ d10267 1 a10267 1 ‘scalars’ d10270 2 a10271 2 unions, etc, is replaced by ‘...’. This is the default. Here is an example where only scalar arguments are shown: d10276 1 a10276 1 ‘none’ d10278 1 a10278 1 of each argument is replaced by ‘...’. In this case, the d10284 3 a10286 3 ‘presence’ Only the presence of arguments is indicated by ‘...’. The ‘...’ are not printed for function without any arguments. a10291 11 By default, only scalar arguments are printed. This command can be used to configure the debugger to print the value of all arguments, regardless of their type. However, it is often advantageous to not print the value of more complex parameters. For instance, it reduces the amount of information printed in each frame, making the backtrace more readable. Also, it improves performance when displaying Ada frames, because the computation of large arguments can sometimes be CPU-intensive, especially in large applications. Setting ‘print frame-arguments’ to ‘scalars’ (the default), ‘none’ or ‘presence’ avoids this computation, thus speeding up the display of each Ada frame. d10293 15 a10307 3 ‘show print frame-arguments’ Show how the value of arguments should be displayed when printing a frame. d10309 1 a10309 1 ‘set print raw-frame-arguments on’ d10312 1 a10312 1 ‘set print raw-frame-arguments off’ d10317 1 a10317 1 ‘show print raw-frame-arguments’ d10320 1 a10320 1 ‘set print entry-values VALUE’ d10328 9 a10336 9 The default value is ‘default’ (see below for its description). Older GDB behaved as with the setting ‘no’. Compilers not supporting this feature will behave in the ‘default’ setting the same way as with the ‘no’ setting. This functionality is currently supported only by DWARF 2 debugging format and the compiler has to produce ‘DW_TAG_call_site’ tags. With GCC, you need to specify ‘-O -g’ during compilation, to get this information. d10340 1 a10340 1 ‘no’ d10349 1 a10349 1 ‘only’ d10358 1 a10358 1 ‘preferred’ d10368 1 a10368 1 ‘if-needed’ d10378 1 a10378 1 ‘both’ d10388 1 a10388 1 ‘compact’ d10390 4 a10393 4 value from function entry point if it is known. If neither is known, print for the actual value ‘’. If not in MI mode (*note GDB/MI::) and if both values are known and identical, print the shortened ‘param=param@@entry=VALUE’ d10401 5 a10405 5 ‘default’ Always print the actual parameter value. Print also its value from function entry point, but only if it is known. If not in MI mode (*note GDB/MI::) and if both values are known and identical, print the shortened ‘param=param@@entry=VALUE’ d10413 7 a10419 2 For analysis messages on possible failures of frame argument values at function entry resolution see *note set debug entry-values::. d10421 1 a10421 5 ‘show print entry-values’ Show the method being used for printing of frame argument values at function entry. ‘set print frame-info VALUE’ d10423 6 a10428 6 debugger prints a frame. See *note Frames::, *note Backtrace::, for a general explanation about frames and frame information. Note that some other settings (such as ‘set print frame-arguments’ and ‘set print address’) are also influencing if and how some frame information is displayed. In particular, the frame program counter is never printed if ‘set print address’ is off. d10430 2 a10431 2 The possible values for ‘set print frame-info’ are: ‘short-location’ d10435 3 a10437 2 ‘location’ Same as ‘short-location’ but also print the source file and d10439 3 a10441 2 ‘location-and-address’ Same as ‘location’ but print the program counter even if d10443 2 a10444 1 ‘source-line’ d10447 5 a10451 3 ‘source-and-location’ Print what ‘location’ and ‘source-line’ are printing. ‘auto’ d10453 5 a10457 5 by the GDB command that prints a frame. For example, ‘frame’ prints the information printed by ‘source-and-location’ while ‘stepi’ will switch between ‘source-line’ and ‘source-and-location’ depending on the program counter. The default value is ‘auto’. d10459 2 a10460 2 ‘set print repeats NUMBER-OF-REPEATS’ ‘set print repeats unlimited’ d10463 2 a10464 2 array exceeds the threshold, GDB prints the string ‘""’, where N is the number of identical repetitions, instead d10466 1 a10466 1 threshold to ‘unlimited’ or zero will cause all elements to be d10469 1 a10469 1 ‘show print repeats’ d10473 3 a10475 2 ‘set print max-depth DEPTH’ ‘set print max-depth unlimited’ d10489 2 a10490 2 The following table shows how different values of DEPTH will effect how ‘var’ is printed by GDB: d10492 8 a10499 8 DEPTH setting Result of ‘p var’ -------------------------------------------------------------------------- unlimited ‘$1 = {d = {c = {b = {a = 3}}}}’ ‘0’ ‘$1 = {...}’ ‘1’ ‘$1 = {d = {...}}’ ‘2’ ‘$1 = {d = {c = {...}}}’ ‘3’ ‘$1 = {d = {c = {b = {...}}}}’ ‘4’ ‘$1 = {d = {c = {b = {a = 3}}}}’ d10514 2 a10515 2 language, for most languages ‘{...}’ is used, but Fortran uses ‘(...)’. d10517 1 a10517 1 ‘show print max-depth’ d10521 2 a10522 2 ‘set print memory-tag-violations’ ‘set print memory-tag-violations on’ d10526 1 a10526 1 ‘set print memory-tag-violations off’ d10529 1 a10529 1 ‘show print memory-tag-violations’ d10533 1 a10533 1 ‘set print null-stop’ d10538 1 a10538 1 ‘show print null-stop’ d10542 1 a10542 1 ‘set print pretty on’ d10555 1 a10555 1 ‘set print pretty off’ d10563 1 a10563 1 ‘show print pretty’ d10566 1 a10566 1 ‘set print raw-values on’ d10570 1 a10570 1 ‘set print raw-values off’ d10577 1 a10577 1 ‘show print raw-values’ d10580 1 a10580 1 ‘set print sevenbit-strings on’ d10583 3 a10585 3 using the notation ‘\’NNN. This setting is best if you are working in English (ASCII) and you use the high-order bit of characters as a marker or "meta" bit. d10587 1 a10587 1 ‘set print sevenbit-strings off’ d10591 1 a10591 1 ‘show print sevenbit-strings’ d10594 1 a10594 1 ‘set print union on’ d10598 1 a10598 1 ‘set print union off’ d10600 1 a10600 1 other unions. GDB will print ‘"{...}"’ instead. d10602 1 a10602 1 ‘show print union’ d10623 1 a10623 1 with ‘set print union on’ in effect ‘p foo’ would print d10627 1 a10627 1 and with ‘set print union off’ in effect it would print d10631 1 a10631 1 ‘set print union’ affects programs written in C-like languages and d10636 2 a10637 2 ‘set print demangle’ ‘set print demangle on’ d10642 1 a10642 1 ‘show print demangle’ d10645 2 a10646 2 ‘set print asm-demangle’ ‘set print asm-demangle on’ d10651 1 a10651 1 ‘show print asm-demangle’ d10655 1 a10655 1 ‘set demangle-style STYLE’ d10658 2 a10659 2 possible formats. The default value is AUTO, which lets GDB choose a decoding style by inspecting your program. d10661 1 a10661 1 ‘show demangle-style’ d10665 2 a10666 2 ‘set print object’ ‘set print object on’ d10676 1 a10676 1 ‘set print object off’ d10680 1 a10680 1 ‘show print object’ d10683 2 a10684 2 ‘set print static-members’ ‘set print static-members on’ d10688 1 a10688 1 ‘set print static-members off’ d10691 1 a10691 1 ‘show print static-members’ d10694 2 a10695 2 ‘set print pascal_static-members’ ‘set print pascal_static-members on’ d10699 1 a10699 1 ‘set print pascal_static-members off’ d10702 1 a10702 1 ‘show print pascal_static-members’ d10705 2 a10706 2 ‘set print vtbl’ ‘set print vtbl on’ d10708 2 a10709 2 (The ‘vtbl’ commands do not work on programs compiled with the HP ANSI C++ compiler (‘aCC’).) d10711 1 a10711 1 ‘set print vtbl off’ d10714 1 a10714 1 ‘show print vtbl’ d10724 3 a10726 3 GDB provides a mechanism to allow pretty-printing of values using Python code. It greatly simplifies the display of complex objects. This mechanism works for both MI and the CLI. d10746 1 a10746 1 The ‘info pretty-printer’ command will list all the installed d10748 1 a10748 1 multiple data types, then its “subprinters” are the printers for the d10752 1 a10752 1 Pretty-printers are installed by “registering” them with GDB. d10759 1 a10759 1 • Pretty-printers registered globally are available when debugging d10762 1 a10762 1 • Pretty-printers registered with a program space are available only d10766 1 a10766 1 • Pretty-printers registered with an objfile are loaded and unloaded d10782 1 a10782 1 Here is how a C++ ‘std::string’ looks without a pretty-printer: d10798 1 a10798 1 With a pretty-printer for ‘std::string’ only the contents are d10810 1 a10810 1 ‘info pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]’ d10815 1 a10815 1 pretty-printers to list. Objects can be ‘global’, the program d10824 1 a10824 1 ‘disable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]’ d10829 1 a10829 1 ‘enable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]’ d10835 3 a10837 3 named ‘foo’ that prints objects of type ‘foo’, and another from library2.so named ‘bar’ that prints two types of objects, ‘bar1’ and ‘bar2’. d10880 1 a10880 1 Note that for ‘bar’ the entire printer can be disabled, as can each d10886 8 a10893 8 The print option ‘-raw-values’ and GDB setting ‘set print raw-values’ (*note set print raw-values::) can be used to print values without applying the enabled pretty printers. Similarly, the backtrace option ‘-raw-frame-arguments’ and GDB setting ‘set print raw-frame-arguments’ (*note set print raw-frame-arguments::) can be used to ignore the enabled pretty printers when printing frame argument values. d10901 2 a10902 2 Values printed by the ‘print’ command are saved in the GDB “value history”. This allows you to refer to them in other expressions. d10904 1 a10904 1 example with the ‘file’ or ‘symbol-file’ commands). When the symbol d10908 11 a10918 11 The values printed are given “history numbers” by which you can refer to them. These are successive integers starting with one. ‘print’ shows you the history number assigned to a value by printing ‘$NUM = ’ before the value; here NUM is the history number. To refer to any previous value, use ‘$’ followed by the value's history number. The way ‘print’ labels its output is designed to remind you of this. Just ‘$’ refers to the most recent value in the history, and ‘$$’ refers to the value before that. ‘$$N’ refers to the Nth value from the end; ‘$$2’ is the value just prior to ‘$$’, ‘$$1’ is equivalent to ‘$$’, and ‘$$0’ is equivalent to ‘$’. d10925 1 a10925 1 If you have a chain of structures where the component ‘next’ points d10934 1 a10934 1 of ‘x’ is 4 and you type these commands: d10939 2 a10940 2 then the value recorded in the value history by the ‘print’ command remains 4 even though the value of ‘x’ has changed. d10942 1 a10942 1 ‘show values’ d10944 2 a10945 2 numbers. This is like ‘p $$9’ repeated ten times, except that ‘show values’ does not change the history. d10947 1 a10947 1 ‘show values N’ d10950 3 a10952 3 ‘show values +’ Print ten history values just after the values last printed. If no more values are available, ‘show values +’ produces no display. d10954 2 a10955 2 Pressing to repeat ‘show values N’ has exactly the same effect as ‘show values +’. d10963 5 a10967 5 GDB provides “convenience variables” that you can use within GDB to hold on to a value and refer to it later. These variables exist entirely within GDB; they are not part of your program, and setting a convenience variable has no direct effect on further execution of your program. That is why you can use them freely. d10969 2 a10970 2 Convenience variables are prefixed with ‘$’. Any name preceded by ‘$’ can be used for a convenience variable, unless it is one of the d10973 1 a10973 1 preceded by ‘$’. *Note Value History: Value History.) d10981 2 a10982 2 would save in ‘$foo’ the value contained in the object pointed to by ‘object_ptr’. d10985 1 a10985 1 value is ‘void’ until you assign a new value. You can alter the value d10989 4 a10992 4 convenience variable any type of value, including structures and arrays, even if that variable already has a value of a different type. The convenience variable, when used as an expression, has the type of its current value. d10994 1 a10994 1 ‘show convenience’ d10997 1 a10997 1 Abbreviated ‘show conv’. d10999 3 a11001 3 ‘init-if-undefined $VARIABLE = EXPRESSION’ Set a convenience variable if it has not already been set. This is useful for user-defined commands that keep some state. It is d11022 2 a11023 2 ‘$_’ The variable ‘$_’ is automatically set by the ‘x’ command to the d11025 5 a11029 5 commands which provide a default address for ‘x’ to examine also set ‘$_’ to that address; these commands include ‘info line’ and ‘info breakpoint’. The type of ‘$_’ is ‘void *’ except when set by the ‘x’ command, in which case it is a pointer to the type of ‘$__’. d11031 2 a11032 2 ‘$__’ The variable ‘$__’ is automatically set by the ‘x’ command to the d11036 1 a11036 1 ‘$_exitcode’ d11039 1 a11039 1 and resets ‘$_exitsignal’ to ‘void’. d11041 4 a11044 4 ‘$_exitsignal’ When the program being debugged dies due to an uncaught signal, GDB automatically sets this variable to that signal's number, and resets ‘$_exitcode’ to ‘void’. d11047 2 a11048 2 exited (i.e., ‘$_exitcode’ is not ‘void’) or signalled (i.e., ‘$_exitsignal’ is not ‘void’), the convenience function ‘$_isvoid’ d11082 3 a11084 3 debugged has signalled, since it calls ‘raise’ and raises a ‘SIGALRM’ signal. If the program being debugged had not called ‘raise’, then GDB would report a normal exit: d11089 2 a11090 2 ‘$_exception’ The variable ‘$_exception’ is set to the exception object being d11094 2 a11095 2 ‘$_ada_exception’ The variable ‘$_ada_exception’ is set to the address of the d11099 2 a11100 2 ‘$_probe_argc’ ‘$_probe_arg0...$_probe_arg11’ d11103 2 a11104 2 ‘$_sdata’ The variable ‘$_sdata’ contains extra collected static tracepoint d11106 1 a11106 1 that ‘$_sdata’ could be empty, if not inspecting a trace buffer, or d11109 5 a11113 5 ‘$_siginfo’ The variable ‘$_siginfo’ contains extra signal information (*note extra signal information::). Note that ‘$_siginfo’ could be empty, if the application has not yet received any signals. For example, it will be empty before you execute the ‘run’ command. d11115 2 a11116 2 ‘$_tlb’ The variable ‘$_tlb’ is automatically set when debugging d11118 1 a11118 1 gdbserver that supports the ‘qGetTIBAddr’ request. *Note General d11122 1 a11122 1 ‘$_inferior’ d11127 1 a11127 1 ‘$_thread’ d11130 1 a11130 1 ‘$_gthread’ d11134 1 a11134 1 ‘$_inferior_thread_count’ d11138 2 a11139 2 ‘$_gdb_major’ ‘$_gdb_minor’ d11143 1 a11143 1 value 12 for ‘$_gdb_minor’. These variables allow you to write d11147 9 a11155 8 ‘$_shell_exitcode’ ‘$_shell_exitsignal’ GDB commands such as ‘shell’ and ‘|’ are launching shell commands. When a launched command terminates, GDB automatically maintains the variables ‘$_shell_exitcode’ and ‘$_shell_exitsignal’ according to the exit status of the last launched command. These variables are set and used similarly to the variables ‘$_exitcode’ and ‘$_exitsignal’. d11163 3 a11165 3 GDB also supplies some “convenience functions”. These have a syntax similar to convenience variables. A convenience function can be used in an expression just like an ordinary function; however, a convenience d11168 1 a11168 1 These functions do not require GDB to be configured with ‘Python’ d11171 2 a11172 2 ‘$_isvoid (EXPR)’ Return one if the expression EXPR is ‘void’. Otherwise it returns d11175 4 a11178 4 A ‘void’ expression is an expression where the type of the result is ‘void’. For example, you can examine a convenience variable (see *note Convenience Variables: Convenience Vars.) to check whether it is ‘void’: d11192 4 a11195 4 In the example above, we used ‘$_isvoid’ to check whether ‘$_exitcode’ is ‘void’ before and after the execution of the program being debugged. Before the execution there is no exit code to be examined, therefore ‘$_exitcode’ is ‘void’. After the d11197 1 a11197 1 ‘$_exitcode’ is zero, which means that it is not ‘void’ anymore. d11199 1 a11199 1 The ‘void’ expression can also be a call of a function from the d11207 1 a11207 1 The result of calling it inside GDB is ‘void’: d11219 1 a11219 1 ‘$_gdb_setting_str (SETTING)’ d11221 1 a11221 1 setting that can be used in a ‘set’ or ‘show’ command (*note d11232 1 a11232 1 ‘$_gdb_setting (SETTING)’ d11236 17 a11252 16 The value type for boolean and auto boolean settings is ‘int’. The boolean values ‘off’ and ‘on’ are converted to the integer values ‘0’ and ‘1’. The value ‘auto’ is converted to the value ‘-1’. The value type for integer settings is either ‘unsigned int’ or ‘int’, depending on the setting. Some integer settings accept an ‘unlimited’ value. Depending on the setting, the ‘set’ command also accepts the value ‘0’ or the value ‘−1’ as a synonym for ‘unlimited’. For example, ‘set height unlimited’ is equivalent to ‘set height 0’. Some other settings that accept the ‘unlimited’ value use the value ‘0’ to literally mean zero. For example, ‘set history size 0’ indicates to not record any GDB commands in the command history. For such settings, ‘−1’ is the synonym for ‘unlimited’. d11254 2 a11255 2 See the documentation of the corresponding ‘set’ command for the numerical value equivalent to ‘unlimited’. d11257 2 a11258 2 The ‘$_gdb_setting’ function converts the unlimited value to a ‘0’ or a ‘−1’ value according to what the ‘set’ command uses. d11282 13 a11294 14 ‘$_gdb_maint_setting_str (SETTING)’ Like the ‘$_gdb_setting_str’ function, but works with ‘maintenance set’ variables. ‘$_gdb_maint_setting (SETTING)’ Like the ‘$_gdb_setting’ function, but works with ‘maintenance set’ variables. ‘$_shell (COMMAND-STRING)’ Invoke a shell to execute COMMAND-STRING. COMMAND-STRING must be a string. The shell runs on the host machine, the machine GDB is running on. Returns the command's exit status. On Unix systems, a command which exits with a zero exit status has succeeded, and d11303 2 a11304 2 determined in the same way as for the ‘shell’ command. *Note Shell Commands: Shell Commands. d11333 3 a11335 3 Note: unlike the ‘shell’ command, the ‘$_shell’ convenience function does not affect the ‘$_shell_exitcode’ and ‘$_shell_exitsignal’ convenience variables. d11337 2 a11338 1 The following functions require GDB to be configured with ‘Python’ d11341 1 a11341 1 ‘$_memeq(BUF1, BUF2, LENGTH)’ d11345 5 a11349 4 ‘$_regex(STR, REGEX)’ Returns one if the string STR matches the regular expression REGEX. Otherwise it returns zero. The syntax of the regular expression is that specified by ‘Python’'s regular expression support. d11351 1 a11351 1 ‘$_streq(STR1, STR2)’ d11355 1 a11355 1 ‘$_strlen(STR)’ d11358 1 a11358 1 ‘$_caller_is(NAME[, NUMBER_OF_FRAMES])’ d11381 1 a11381 1 ‘$_caller_matches(REGEXP[, NUMBER_OF_FRAMES])’ d11388 1 a11388 1 ‘$_any_caller_is(NAME[, NUMBER_OF_FRAMES])’ d11395 1 a11395 1 This function differs from ‘$_caller_is’ in that this function d11397 1 a11397 1 specified by NUMBER_OF_FRAMES, whereas ‘$_caller_is’ only checks d11400 1 a11400 1 ‘$_any_caller_matches(REGEXP[, NUMBER_OF_FRAMES])’ d11407 1 a11407 1 This function differs from ‘$_caller_matches’ in that this function d11409 1 a11409 1 specified by NUMBER_OF_FRAMES, whereas ‘$_caller_matches’ only d11412 1 a11412 1 ‘$_as_string(VALUE)’ d11414 2 a11415 2 removed from future versions of GDB. Use the ‘%V’ format specifier instead (*note %V Format Specifier::). d11419 3 a11421 3 This function is useful to obtain the textual label (enumerator) of an enumeration value. For example, assuming the variable NODE is of an enumerated type: d11426 3 a11428 3 ‘$_cimag(VALUE)’ ‘$_creal(VALUE)’ Return the imaginary (‘$_cimag’) or real (‘$_creal’) part of the d11432 3 a11434 2 complex number, e.g., using ‘$_cimag’ on a ‘float complex’ will return an imaginary part of type ‘float’. d11439 1 a11439 1 ‘help function’ d11449 2 a11450 2 with names starting with ‘$’. The names of registers are different for each machine; use ‘info registers’ to see the names used on your d11453 1 a11453 1 ‘info registers’ d11457 1 a11457 1 ‘info all-registers’ d11461 1 a11461 1 ‘info registers REGGROUP ...’ d11463 2 a11464 2 REGGROUPs. The REGGROUP can be any of those returned by ‘maint print reggroups’ (*note Maintenance Commands::). d11466 6 a11471 6 ‘info registers REGNAME ...’ Print the “relativized” value of each specified register REGNAME. As discussed in detail below, register values are normally relative to the selected stack frame. The REGNAME may be any register name valid on the machine you are using, with or without the initial ‘$’. d11476 3 a11478 3 ‘$pc’ and ‘$sp’ are used for the program counter register and the stack pointer. ‘$fp’ is used for a register that contains a pointer to the current stack frame, and ‘$ps’ is used for a register that contains the d11494 4 a11497 4 mnemonics, so long as there is no conflict. The ‘info registers’ command shows the canonical names. For example, on the SPARC, ‘info registers’ displays the processor status register as ‘$psr’ but you can also refer to it as ‘$ps’; and on x86-based machines ‘$ps’ is an alias d11505 2 a11506 2 (although you can _print_ it as a floating point value with ‘print/f $REGNAME’). d11515 1 a11515 1 sense for your program), but the ‘info registers’ command prints the d11522 1 a11522 1 ‘struct’ notation: d11537 1 a11537 1 ‘struct’ member: d11545 2 a11546 2 true contents of hardware registers, you must select the innermost frame (with ‘frame 0’). d11554 2 a11555 2 debug info, unwind info, or the machine code generated by your compiler. If some register is not saved, and GDB knows the register is d11558 1 a11558 1 GDB displays ‘’ as the register's value. With targets that d11565 5 a11569 5 change such a register in the outer frame, you may also be affecting the inner frame. Also, the more "outer" the frame is you're looking at, the more likely a call-clobbered register's value is to be wrong, in the sense that it doesn't actually represent the value the register had just before the call. d11575 4 a11578 4 assumes that the innermost stack frame is selected; setting ‘$sp’ is not allowed when other stack frames are selected. To pop entire frames off the stack, regardless of machine architecture, use ‘return’; see *note Returning from a Function: Returning. d11589 1 a11589 1 ‘info float’ d11591 3 a11593 3 unit. The exact contents and layout vary depending on the floating point chip. Currently, ‘info float’ is supported on the ARM and x86 machines. d11604 1 a11604 1 ‘info vector’ d11617 11 a11627 10 Some operating systems supply an “auxiliary vector” to programs at startup. This is akin to the arguments and environment that you specify for a program, but contains a system-dependent variety of binary values that tell system libraries important details about the hardware, operating system, and process. Each value's purpose is identified by an integer tag; the meanings are well-known but system-specific. Depending on the configuration and operating system facilities, GDB may be able to show you this information. For remote targets, this functionality may further depend on the remote stub's support of the ‘qXfer:auxv:read’ packet, see *note qXfer auxiliary vector read::. d11629 1 a11629 1 ‘info auxv’ d11638 7 a11644 9 On some targets, GDB can access operating system-specific information and show it to you. The types of information available will differ depending on the type of operating system running on the target. The mechanism used to fetch the data is described in *note Operating System Information::. For remote targets, this functionality depends on the remote stub's support of the ‘qXfer:osdata:read’ packet, see *note qXfer osdata read::. ‘info os INFOTYPE’ d11646 1 d11651 4 a11654 4 ‘cpus’ Display the list of all CPUs/cores. For each CPU/core, GDB prints the available fields from /proc/cpuinfo. For each supported architecture different fields are available. Two d11659 1 a11659 1 ‘files’ d11665 1 a11665 1 ‘modules’ d11672 10 a11681 10 ‘msg’ Display the list of all System V message queues on the target. For each message queue, GDB prints the message queue key, the message queue identifier, the access permissions, the current number of bytes on the queue, the current number of messages on the queue, the processes that last sent and received a message on the queue, the user and group of the owner and creator of the message queue, the times at which a message was last sent and received on the queue, and the time at which the message queue was last changed. d11683 1 a11683 1 ‘processes’ d11692 1 a11692 1 ‘procgroups’ d11702 7 a11708 7 ‘semaphores’ Display the list of all System V semaphore sets on the target. For each semaphore set, GDB prints the semaphore set key, the semaphore set identifier, the access permissions, the number of semaphores in the set, the user and group of the owner and creator of the semaphore set, and the times at which the semaphore set was operated upon and changed. d11710 1 a11710 1 ‘shm’ d11713 6 a11718 6 key, the shared-memory identifier, the access permissions, the size of the region, the process that created the region, the process that last attached to or detached from the region, the current number of live attaches to the region, and the times at which the region was last attached to, detach from, and changed. d11720 1 a11720 1 ‘sockets’ d11723 3 a11725 3 and remote endpoints, the current state of the connection, the creator of the socket, the IP address family of the socket, and the type of the connection. d11727 1 a11727 1 ‘threads’ d11734 1 a11734 1 ‘info os’ d11736 3 a11738 3 and the kind of OS information available for each INFOTYPE. If the target does not return a list of possible types, this command will report an error. d11746 1 a11746 1 “Memory region attributes” allow you to describe special handling d11750 3 a11752 3 default the description of memory regions is fetched from the target (if the current target supports this), but the user can override the fetched regions. d11762 1 a11762 1 ‘mem LOWER UPPER ATTRIBUTES...’ d11769 1 a11769 1 ‘mem auto’ d11774 3 a11776 3 ‘delete mem NUMS...’ Remove memory regions NUMS... from the list of regions monitored by GDB. d11778 1 a11778 1 ‘disable mem NUMS...’ d11782 1 a11782 1 ‘enable mem NUMS...’ d11785 1 a11785 1 ‘info mem’ d11789 1 a11789 4 _Memory Region Number_ _Enabled or Disabled._ Enabled memory regions are marked with ‘y’. Disabled memory regions are marked with ‘n’. d11791 5 a11795 1 _Lo Address_ d11799 1 a11799 1 _Hi Address_ d11803 1 a11803 1 _Attributes_ d11819 1 a11819 1 ‘ro’ d11821 2 a11822 1 ‘wo’ d11824 2 a11825 1 ‘rw’ d11836 1 a11836 1 ‘8’ d11838 2 a11839 1 ‘16’ d11841 2 a11842 1 ‘32’ d11844 2 a11845 1 ‘64’ d11856 1 a11856 1 ‘cache’ d11858 2 a11859 1 ‘nocache’ d11870 2 a11871 2 ‘set mem inaccessible-by-default [on|off]’ If ‘on’ is specified, make GDB treat memory not explicitly d11874 1 a11874 1 one memory range defined. If ‘off’ is specified, make GDB treat d11876 3 a11878 2 The default value is ‘on’. ‘show mem inaccessible-by-default’ d11887 3 a11889 3 You can use the commands ‘dump’, ‘append’, and ‘restore’ to copy data between target memory and a file. The ‘dump’ and ‘append’ commands write data to a file, and the ‘restore’ command reads data from a file d11894 2 a11895 2 ‘dump [FORMAT] memory FILENAME START_ADDR END_ADDR’ ‘dump [FORMAT] value FILENAME EXPR’ d11900 1 a11900 1 ‘binary’ d11902 2 a11903 1 ‘ihex’ d11905 2 a11906 1 ‘srec’ d11908 2 a11909 1 ‘tekhex’ d11911 2 a11912 1 ‘verilog’ d11916 2 a11917 2 utilities, like ‘objdump’ and ‘objcopy’. If FORMAT is omitted, GDB dumps the data in raw binary form. d11919 2 a11920 2 ‘append [binary] memory FILENAME START_ADDR END_ADDR’ ‘append [binary] value FILENAME EXPR’ d11925 2 a11926 2 ‘restore FILENAME [binary] BIAS START END’ Restore the contents of file FILENAME into memory. The ‘restore’ d11929 1 a11929 1 specify the optional keyword ‘binary’ after the filename. d11939 3 a11941 2 are relative to the addresses in the file, before the BIAS argument is applied. d11949 1 a11949 1 A “core file” or “core dump” is a file that records the memory image of d11952 4 a11955 3 ran outside a debugger. A program that crashes automatically produces a core file, unless this feature is disabled by the user. *Note Files::, for information on invoking GDB in the post-mortem debugging mode. d11961 2 a11962 2 ‘generate-core-file [FILE]’ ‘gcore [FILE]’ d11965 1 a11965 1 specified, the file name defaults to ‘core.PID’, where PID is the d11975 1 a11975 1 file ‘/proc/PID/coredump_filter’ when generating the core dump d11977 2 a11978 2 ‘VM_DONTDUMP’ flag for mappings where it is present in the file ‘/proc/PID/smaps’ (*note set dump-excluded-mappings::). d11980 3 a11982 3 ‘set use-coredump-filter on’ ‘set use-coredump-filter off’ Enable or disable the use of the file ‘/proc/PID/coredump_filter’ d11985 2 a11986 2 ignored when generating a core dump file. PID is the process ID of a currently running process. d11989 1 a11989 1 ‘/proc/PID/coredump_filter’ file a value, in hexadecimal, which is d11995 2 a11996 2 ‘/proc/PID/coredump_filter’ file, please refer to the manpage of ‘core(5)’. d11998 2 a11999 2 By default, this option is ‘on’. If this option is turned ‘off’, GDB does not read the ‘coredump_filter’ file and instead uses the d12002 3 a12004 3 currently ‘0x33’, which means that bits ‘0’ (anonymous private mappings), ‘1’ (anonymous shared mappings), ‘4’ (ELF headers) and ‘5’ (private huge pages) are active. This will cause these memory d12007 5 a12011 5 ‘set dump-excluded-mappings on’ ‘set dump-excluded-mappings off’ If ‘on’ is specified, GDB will dump memory mappings marked with the ‘VM_DONTDUMP’ flag. This flag is represented in the file ‘/proc/PID/smaps’ with the acronym ‘dd’. d12013 1 a12013 1 The default value is ‘off’. d12024 2 a12025 2 character set GDB uses we call the “host character set”; the one the inferior program uses we call the “target character set”. d12027 8 a12034 8 For example, if you are running GDB on a GNU/Linux system, which uses the ISO Latin 1 character set, but you are using GDB's remote protocol (*note Remote Debugging::) to debug a program running on an IBM mainframe, which uses the EBCDIC character set, then the host character set is Latin-1, and the target character set is EBCDIC. If you give GDB the command ‘set target-charset EBCDIC-US’, then GDB translates between EBCDIC and Latin 1 as you print character or string values, or use character and string literals in expressions. d12037 1 a12037 1 inferior program uses; you must tell it, using the ‘set target-charset’ d12042 1 a12042 1 ‘set target-charset CHARSET’ d12045 1 a12045 1 ‘set target-charset ’. d12047 1 a12047 1 ‘set host-charset CHARSET’ d12050 5 a12054 5 By default, GDB uses a host character set appropriate to the system it is running on; you can override that default using the ‘set host-charset’ command. On some systems, GDB cannot automatically determine the appropriate host character set. In this case, GDB uses ‘UTF-8’. d12057 1 a12057 1 If you type ‘set host-charset ’, GDB will list the host d12060 1 a12060 1 ‘set charset CHARSET’ d12062 1 a12062 1 above, if you type ‘set charset ’, GDB will list the d12066 1 a12066 1 ‘show charset’ d12069 1 a12069 1 ‘show host-charset’ d12072 1 a12072 1 ‘show target-charset’ d12075 1 a12075 1 ‘set target-wide-charset CHARSET’ d12077 1 a12077 1 the character set used by the target's ‘wchar_t’ type. To display d12079 1 a12079 1 ‘set target-wide-charset ’. d12081 1 a12081 1 ‘show target-wide-charset’ d12086 1 a12086 1 ‘charset-test.c’: d12102 2 a12103 2 In this program, ‘ascii_hello’ and ‘ibm1047_hello’ are arrays containing the string ‘Hello, world!’ followed by a newline, encoded in d12115 1 a12115 1 We can use the ‘show charset’ command to see what character sets GDB d12131 3 a12133 3 characters using the ASCII character set, our terminal will display them properly. Since our current target character set is also ASCII, the contents of ‘ascii_hello’ print legibly: d12148 1 a12148 1 The ASCII character set uses the number 43 to encode the ‘+’ d12152 1 a12152 1 program uses. If we print ‘ibm1047_hello’ while our target character d12161 1 a12161 1 If we invoke the ‘set target-charset’ followed by , GDB d12170 1 a12170 1 translates the contents of ‘ibm1047_hello’ from the target character d12195 1 a12195 1 The IBM1047 character set uses the number 78 to encode the ‘+’ d12204 13 a12216 13 GDB caches data exchanged between the debugger and a target. Each cache is associated with the address space of the inferior. *Note Inferiors Connections and Programs::, about inferior and address space. Such caching generally improves performance in remote debugging (*note Remote Debugging::), because it reduces the overhead of the remote protocol by bundling memory reads and writes into large chunks. Unfortunately, simply caching everything would lead to incorrect results, since GDB does not necessarily know anything about volatile values, memory-mapped I/O addresses, etc. Furthermore, in non-stop mode (*note Non-Stop Mode::) memory can be changed _while_ a gdb command is executing. Therefore, by default, GDB only caches data known to be on the stack(1) or in the code segment. Other regions of memory can be explicitly marked as cacheable; *note Memory Region Attributes::. d12218 2 a12219 2 ‘set remotecache on’ ‘set remotecache off’ d12223 1 a12223 1 ‘show remotecache’ d12226 4 a12229 4 ‘set stack-cache on’ ‘set stack-cache off’ Enable or disable caching of stack accesses. When ‘on’, use caching. By default, this option is ‘on’. d12231 1 a12231 1 ‘show stack-cache’ d12234 4 a12237 4 ‘set code-cache on’ ‘set code-cache off’ Enable or disable caching of code segment accesses. When ‘on’, use caching. By default, this option is ‘on’. This improves d12240 1 a12240 1 ‘show code-cache’ d12244 1 a12244 1 ‘info dcache [line]’ d12254 1 a12254 1 ‘set dcache size SIZE’ d12257 1 a12257 1 ‘set dcache line-size LINE-SIZE’ d12261 1 a12261 1 ‘show dcache size’ d12265 1 a12265 1 ‘show dcache line-size’ d12268 4 a12271 3 ‘maint flush dcache’ Flush the contents (if any) of the dcache. This maintainer command is useful when debugging the dcache implementation. d12287 1 a12287 1 ‘find’ command. d12289 2 a12290 2 ‘find [/SN] START_ADDR, +LEN, VAL1 [, VAL2, ...]’ ‘find [/SN] START_ADDR, END_ADDR, VAL1 [, VAL2, ...]’ d12301 1 a12301 1 ‘b’ d12303 2 a12304 1 ‘h’ d12306 2 a12307 1 ‘w’ d12309 2 a12310 1 ‘g’ d12316 2 a12317 2 null terminator can be removed from searching by using casts, e.g.: ‘{char[5]}"hello"’. d12323 2 a12324 2 for an untyped 0x42 will search for ‘(int) 0x42’ which is typically four bytes. d12331 3 a12333 2 (‘"’). The string value is copied into the search pattern byte by byte, regardless of the endianness of the target and the size specification. d12339 1 a12339 1 ‘$_’. A count of the number of matches is stored in ‘$numfound’. d12341 1 a12341 1 For example, if stopped at the ‘printf’ in this function: d12389 2 a12390 2 ‘set max-value-size BYTES’ ‘set max-value-size unlimited’ d12398 3 a12400 3 There's a minimum size that ‘max-value-size’ can be set to in order that GDB can still operate correctly, this minimum is currently 16 bytes. d12404 1 a12404 1 simple integer component, such as ‘x.y.z’, may fail if the size of d12406 1 a12406 1 sometimes clever; the expression ‘A[i]’, where A is an array d12411 1 a12411 1 The default value of ‘max-value-size’ is currently 64k. d12413 1 a12413 1 ‘show max-value-size’ d12425 5 a12429 5 source code, in a simplistic way. As the compiler applies more powerful optimizations, the generated assembly code diverges from your original source code. With help from debugging information generated by the compiler, GDB can map from the running program back to constructs from your original source. d12436 1 a12436 1 When you debug a program compiled with ‘-g -O’, remember that the d12443 1 a12443 1 Some things do not work as well with ‘-g -O’ as with just ‘-g’, d12445 3 a12447 3 recompile with ‘-g’ alone, and if this fixes the problem, please report it to us as a bug (including a test case!). *Note Variables::, for more information about debugging optimized code. d12460 7 a12466 7 “Inlining” is an optimization that inserts a copy of the function body directly at each call site, instead of jumping to a shared routine. GDB displays inlined functions just like non-inlined functions. They appear in backtraces. You can view their arguments and local variables, step into them with ‘step’, skip them with ‘next’, and escape from them with ‘finish’. You can check whether a function was inlined by using the ‘info frame’ command. d12470 4 a12473 4 DWARF 2 format does this, and several other compilers do also. GDB only supports inlined functions when using DWARF 2. Versions of GCC before 4.1 do not emit two required attributes (‘DW_AT_call_file’ and ‘DW_AT_call_line’); GDB does not display inlined function calls with d12479 5 a12483 4 to the call. GDB still pretends that the call site and the start of the inlined function are different instructions. Stepping to the call site shows the call site, and then stepping again shows the first line of the inlined function, even though no additional instructions are executed. d12486 2 a12487 2 context of the call and then the effect of the call. Only stepping by a single instruction using ‘stepi’ or ‘nexti’ does not do this; single d12493 1 a12493 1 • Setting breakpoints at the call site of an inlined function may not d12500 3 a12502 3 • GDB cannot locate the return value of inlined calls after using the ‘finish’ command. This is a limitation of compiler-generated debugging information; after ‘finish’, you can step to the next d12506 1 d12513 13 a12525 13 Function ‘B’ can call function ‘C’ in its very last statement. In unoptimized compilation the call of ‘C’ is immediately followed by return instruction at the end of ‘B’ code. Optimizing compiler may replace the call and return in function ‘B’ into one jump to function ‘C’ instead. Such use of a jump instruction is called “tail call”. During execution of function ‘C’, there will be no indication in the function call stack frames that it was tail-called from ‘B’. If function ‘A’ regularly calls function ‘B’ which tail-calls function ‘C’, then GDB will see ‘A’ as the caller of ‘C’. However, in some cases GDB can determine that ‘C’ was tail-called from ‘B’, and it will then create fictitious call frame for that, with the return address set up as if ‘B’ called ‘C’ normally. d12528 2 a12529 2 format and the compiler has to produce ‘DW_TAG_call_site’ tags. With GCC, you need to specify ‘-O -g’ during compilation, to get this d12532 3 a12534 2 ‘info frame’ command (*note Frame Info::) will indicate the tail call frame kind by text ‘tail call frame’ such as in this sample GDB output: d12547 3 a12549 3 ambiguous. There is no execution history stored (possible *note Reverse Execution:: is never used for this purpose) and the last known caller could have reached the known callee by multiple different jump d12554 1 a12554 1 ‘set debug entry-values’ d12562 3 a12564 3 ‘show debug entry-values’ Show the current state of analysis messages printing for both frame argument values at function entry and tail calls. d12567 2 a12568 2 virtual tail call frame for function ‘c’ has not been recognized (due to the indirect reference by variable ‘x’): d12605 3 a12607 3 Frames #0 and #2 are real, #1 is a virtual tail call frame. The code can have possible execution paths ‘main→a→b→c→d→f’ or ‘main→a→b→e→f’, GDB cannot find which one from the inferior state. d12609 1 a12609 1 ‘initial:’ state shows some random possible calling sequence GDB has d12611 10 a12620 10 prefixed by ‘compare:’. The non-ambiguous intersection of these two is printed as the ‘reduced:’ calling sequence. That one could have many further ‘compare:’ and ‘reduced:’ statements as long as there remain any non-ambiguous sequence entries. For the frame of function ‘b’ in both cases there are different possible ‘$pc’ values (‘0x4004cc’ or ‘0x4004ce’), therefore this frame is also ambiguous. The only non-ambiguous frame is the one for function ‘a’, therefore this one is displayed to the user while the ambiguous frames are omitted. d12641 4 a12644 4 function ‘a’ call itself (via function ‘b’) as these calls would be tail calls. Such tail calls would modify the ‘i’ variable, therefore GDB cannot be sure the value it knows would be right - GDB prints ‘’ instead. d12661 1 a12661 1 ‘-g’ flag. *Note Compilation::. d12665 5 a12669 5 different points in the program, a macro may have different definitions, or have no definition at all. If there is a current stack frame, GDB uses the macros in scope at that frame's source code line. Otherwise, GDB uses the macros in scope at the current listing location; see *note List::. d12675 2 a12676 2 ‘macro expand EXPRESSION’ ‘macro exp EXPRESSION’ d12682 2 a12683 2 ‘macro expand-once EXPRESSION’ ‘macro exp1 EXPRESSION’ d12693 1 a12693 1 ‘info macro [-a|-all] [--] MACRO’ d12700 1 a12700 1 ‘info macros LOCSPEC’ d12702 2 a12703 2 the code location that results from resolving LOCSPEC, and describe the source location or compiler command-line where those d12706 2 a12707 2 ‘macro define MACRO REPLACEMENT-LIST’ ‘macro define MACRO(ARGLIST) REPLACEMENT-LIST’ d12716 2 a12717 2 expression evaluated in GDB, until it is removed with the ‘macro undef’ command, described below. The definition overrides all d12721 1 a12721 1 ‘macro undef MACRO’ d12723 2 a12724 2 This command only affects definitions provided with the ‘macro define’ command, described above; it cannot remove definitions d12727 2 a12728 2 ‘macro list’ List all the macros defined using the ‘macro define’ command. d12754 1 a12754 1 the ‘-gdwarf-2’(1) _and_ ‘-g3’ flags to ensure the compiler includes d12769 2 a12770 2 program is not running. GDB uses the current listing position to decide which macro definitions are in scope: d12796 1 a12796 1 In the example above, note that ‘macro expand-once’ expands only the d12798 2 a12799 2 ‘ADD’ -- but does not expand the invocation of the macro ‘M’, which was introduced by ‘ADD’. d12813 1 a12813 1 At line 10, the definition of the macro ‘N’ at line 9 is in force: d12824 1 a12824 1 As we step over directives that remove ‘N’'s definition, and then d12846 4 a12849 4 In addition to source files, macros can be defined on the compilation command line using the ‘-DNAME=VALUE’ syntax. For macros defined in such a way, GDB displays the location of their definition as line zero of the source file submitted to the compiler. d12858 3 a12860 3 (1) This is the minimum. Recent versions of GCC support ‘-gdwarf-3’ and ‘-gdwarf-4’; we recommend always choosing the most recent version of DWARF. d12870 2 a12871 2 helpful about its behavior. If the program's correctness depends on its real-time behavior, delays introduced by a debugger might cause the d12876 11 a12886 10 Using GDB's ‘trace’ and ‘collect’ commands, you can specify locations in the program, called “tracepoints”, and arbitrary expressions to evaluate when those tracepoints are reached. Later, using the ‘tfind’ command, you can examine the values those expressions had when the program hit the tracepoints. The expressions may also denote objects in memory--structures or arrays, for example--whose values GDB should record; while visiting a particular tracepoint, you may inspect those objects as if they were in memory at that moment. However, because GDB records these values without interacting with you, it can do so quickly and unobtrusively, hopefully not disturbing the program's behavior. d12893 1 a12893 1 to implement tracepoints are described in *note Tracepoint Packets::. d12896 1 a12896 1 reminiscent of corefiles; you specify the filename, and use ‘tfind’ to d12914 1 a12914 1 Before running such a “trace experiment”, an arbitrary number of d12916 5 a12920 5 breakpoint (*note Set Breaks::), so you can manipulate it using standard breakpoint commands. For instance, as with breakpoints, tracepoint numbers are successive integers starting from one, and many of the commands associated with tracepoints take the tracepoint number as their argument, to identify which tracepoint to work on. d12932 1 a12932 1 Some targets may support “fast tracepoints”, which are inserted in a d12938 14 a12951 13 the target. Some targets may also support controlling “static tracepoints” from GDB. With static tracing, a set of instrumentation points, also known as “markers”, are embedded in the target program, and can be activated or deactivated by name or address. These are usually placed at locations which facilitate investigating what the target is actually doing. GDB's support for static tracing includes being able to list instrumentation points, and attach them with GDB defined high level tracepoints that expose the whole range of convenience of GDB's tracepoints support. Namely, support for collecting registers values and values of global or local (to the instrumentation point) variables; tracepoint conditions and trace state variables. The act of installing a GDB static tracepoint on an instrumentation point, or marker, is referred to as “probing” a static tracepoint marker. d12953 2 a12954 2 ‘gdbserver’ supports tracepoints on some target systems. *Note Tracepoints support in ‘gdbserver’: Server. d12978 2 a12979 2 ‘trace LOCSPEC’ The ‘trace’ command is very similar to the ‘break’ command. Its d12981 1 a12981 1 Location Specifications::. The ‘trace’ command defines a d12986 3 a12988 3 ‘InstallInTrace’ feature (*note install tracepoint in tracing::). If remote stub doesn't support the ‘InstallInTrace’ feature, all these changes don't take effect until the next ‘tstart’ command, d12991 1 a12991 1 addition, GDB supports “pending tracepoints”--tracepoints whose d12993 4 a12996 4 breakpoints.) Pending tracepoints are not downloaded to the target and not installed until they are resolved. The resolution of pending tracepoints requires GDB support--when debugging with the remote target, and GDB disconnects from the remote stub (*note d13000 1 a13000 1 Here are some examples of using the ‘trace’ command: d13012 1 a13012 1 You can abbreviate ‘trace’ as ‘tr’. d13014 1 a13014 1 ‘trace LOCSPEC if COND’ d13021 2 a13022 2 ‘ftrace LOCSPEC [ if COND ]’ The ‘ftrace’ command sets a fast tracepoint. For targets that d13024 4 a13027 4 possibly less general technique to trigger data collection, such as a jump instruction instead of a trap, or some sort of hardware support. It may not be possible to create a fast tracepoint at the desired location, in which case the command will exit with an d13030 1 a13030 1 GDB handles arguments to ‘ftrace’ exactly as for ‘trace’. d13035 5 a13039 5 target program is available to install trampolines. Some Unix-type systems, such as GNU/Linux, exclude low addresses from the program's address space; but for instance with the Linux kernel it is possible to let GDB use this area by doing a ‘sysctl’ command to set the ‘mmap_min_addr’ kernel parameter, as in d13046 2 a13047 2 ‘strace [LOCSPEC | -m MARKER] [ if COND ]’ The ‘strace’ command sets a static tracepoint. For targets that d13054 2 a13055 2 GDB handles arguments to ‘strace’ exactly as for ‘trace’, with the addition that the user can also specify ‘-m MARKER’ instead of a d13058 3 a13060 3 tracepoint backend library your program is using. You can find all the marker identifiers in the ‘ID’ field of the ‘info static-tracepoint-markers’ command output. *Note Listing Static d13071 1 a13071 1 ‘trace_mark’ call with a slash, which translates to: d13083 2 a13084 2 Static tracepoints accept an extra collect action -- ‘collect $_sdata’. This collects arbitrary user data passed in the probe d13086 5 a13090 5 you'll see that the third argument to ‘trace_mark’ is a printf-like format string. The user data is then the result of running that formatting string against the following arguments. Note that ‘info static-tracepoint-markers’ command output lists that format string in the ‘Data:’ field. d13096 1 a13096 1 The convenience variable ‘$tpnum’ records the tracepoint number of d13099 1 a13099 1 ‘delete tracepoint [NUM]’ d13102 1 a13102 1 ‘delete’ command can remove tracepoints also. d13110 1 a13110 1 You can abbreviate this command as ‘del tr’. d13118 2 a13119 2 These commands are deprecated; they are equivalent to plain ‘disable’ and ‘enable’. d13121 1 a13121 1 ‘disable tracepoint [NUM]’ d13125 1 a13125 1 tracepoint using the ‘enable tracepoint’ command. If the command d13131 1 a13131 1 ‘enable tracepoint [NUM]’ d13144 9 a13152 8 ‘passcount [N [NUM]]’ Set the “passcount” of a tracepoint. The passcount is a way to automatically stop a trace experiment. If a tracepoint's passcount is N, then the trace experiment will be automatically stopped on the N'th time that tracepoint is hit. If the tracepoint number NUM is not specified, the ‘passcount’ command sets the passcount of the most recently defined tracepoint. If no passcount is given, the trace experiment will run until stopped explicitly by the user. d13157 1 a13157 1 // tracepoint 2 d13160 1 a13160 1 // most recently defined tracepoint. d13167 4 a13170 3 // executed 3 times OR when bar has // been executed 2 times // OR when baz has been executed 1 time. d13179 1 a13179 1 reaches a specified place. You can also specify a “condition” for a d13182 2 a13183 2 with a condition evaluates the expression each time your program reaches it, and data collection happens only if the condition is true. d13186 1 a13186 1 using ‘if’ in the arguments to the ‘trace’ command. *Note Setting d13188 1 a13188 1 changed at any time with the ‘condition’ command, just as with d13192 4 a13195 4 conditional expression itself. Instead, GDB encodes the expression into an agent expression (*note Agent Expressions::) suitable for execution on the target, independently of GDB. Global variables become raw memory locations, locals become stack accesses, and so forth. d13200 4 a13203 3 of that function that happen while the error code is propagating through the program; an unconditional tracepoint could end up collecting thousands of useless trace frames that you would have to search through. d13213 1 a13213 1 A “trace state variable” is a special type of variable that is created d13217 1 a13217 1 ‘tvariable’ command. They are always 64-bit signed integers. d13228 7 a13234 7 namespace as other "$" variables, which means that you cannot have trace state variables with names like ‘$23’ or ‘$pc’, nor can you have a trace state variable and a convenience variable with the same name. ‘tvariable $NAME [ = EXPRESSION ]’ The ‘tvariable’ command creates a new trace state variable named ‘$NAME’, and optionally gives it an initial value of EXPRESSION. d13237 1 a13237 1 will report an error. A subsequent ‘tvariable’ command specifying d13240 1 a13240 1 overwriting any previous initial value. The default initial value d13243 1 a13243 1 ‘info tvariables’ d13245 2 a13246 2 Their current values may also be displayed, if the trace experiment is currently running. d13248 1 a13248 1 ‘delete tvariable [ $NAME ... ]’ d13252 1 d13259 1 a13259 1 ‘actions [NUM]’ d13263 6 a13268 6 defined (so that you can define a tracepoint and then say ‘actions’ without bothering about its number). You specify the actions themselves on the following lines, one action at a time, and terminate the actions list with a line containing just ‘end’. So far, the only defined actions are ‘collect’, ‘teval’, and ‘while-stepping’. d13270 1 a13270 1 ‘actions’ is actually equivalent to ‘commands’ (*note Breakpoint d13274 2 a13275 2 To remove all actions from a tracepoint, type ‘actions NUM’ and follow it immediately with ‘end’. d13283 1 a13283 1 In the following example, the action list begins with ‘collect’ d13286 1 a13286 1 following the tracepoint, a ‘while-stepping’ command is used, d13288 3 a13290 3 sequence of single steps. The ‘while-stepping’ command is terminated by its own separate ‘end’ command. Lastly, the action list is terminated by an ‘end’ command. d13302 1 a13302 1 ‘collect[/MODS] EXPR1, EXPR2, ...’ d13308 1 a13308 1 ‘$regs’ d13311 1 a13311 1 ‘$args’ d13314 1 a13314 1 ‘$locals’ d13317 1 a13317 1 ‘$_ret’ d13322 7 a13328 6 determined up front, and the wrong address / registers may end up collected instead. On some architectures the reliability is higher for tracepoints at function entry, while on others it's the opposite. When this happens, backtracing will stop because the return address is found unavailable (unless another collect rule happened to match it). d13330 1 a13330 1 ‘$_probe_argc’ d13334 1 a13334 1 ‘$_probe_argN’ d13339 1 a13339 1 ‘$_sdata’ d13343 6 a13348 6 library backend, an instrumentation point resembles a ‘printf’ function call. The tracing library is able to collect user specified data formatted to a character string using the format provided by the programmer that instrumented the program. Other backends have similar mechanisms. Here's an example of a UST marker call: d13353 3 a13355 3 In this case, collecting ‘$_sdata’ collects the string ‘hello $yourname’. When analyzing the trace buffer, you can inspect ‘$_sdata’ like any other variable available to GDB. d13357 2 a13358 2 You can give several consecutive ‘collect’ commands, each one with a single argument, or one ‘collect’ command with several arguments d13361 2 a13362 2 The optional MODS changes the usual handling of the arguments. ‘s’ requests that pointers to chars be handled as strings, in d13365 1 a13365 1 the ‘print characters’ variable; if ‘s’ is followed by a decimal d13367 1 a13367 1 ‘collect/s25 mystr’ collects as many as 25 characters at ‘mystr’. d13369 1 a13369 1 The command ‘info scope’ (*note info scope: Symbols.) is d13372 1 a13372 1 ‘teval EXPR1, EXPR2, ...’ d13378 1 a13378 1 the ‘collect’ action were used. d13380 1 a13380 1 ‘while-stepping N’ d13382 3 a13384 3 collecting new data after each step. The ‘while-stepping’ command is followed by the list of what to collect while stepping (followed by its own ‘end’ command): d13391 4 a13394 3 Note that ‘$pc’ is not automatically collected by ‘while-stepping’; you need to explicitly collect that register if you need it. You may abbreviate ‘while-stepping’ as ‘ws’ or ‘stepping’. d13396 1 a13396 1 ‘set default-collect EXPR1, EXPR2, ...’ d13398 1 a13398 1 tracepoint hit. It is effectively an additional ‘collect’ action d13400 4 a13403 3 parsed individually for each tracepoint, so for instance a variable named ‘xyz’ may be interpreted as a global for one tracepoint, and a local for another, as appropriate to the tracepoint's location. d13405 1 a13405 1 ‘show default-collect’ d13409 1 d13416 6 a13421 6 ‘info tracepoints [NUM...]’ Display information about the tracepoint NUM. If you don't specify a tracepoint number, displays information about all the tracepoints defined so far. The format is similar to that used for ‘info breakpoints’; in fact, ‘info tracepoints’ is the same command, simply restricting itself to tracepoints. d13426 1 a13426 1 • its passcount as given by the ‘passcount N’ command d13428 1 a13428 1 • the state about installed on target of each location d13450 1 a13450 1 This command can be abbreviated ‘info tp’. d13458 1 a13458 1 ‘info static-tracepoint-markers’ d13464 1 a13464 1 _Count_ d13467 2 a13468 1 _ID_ d13470 6 a13475 4 _Enabled or Disabled_ Probed markers are tagged with ‘y’. ‘n’ identifies marks that are not enabled. _Address_ d13477 2 a13478 1 _What_ d13481 2 a13482 2 program does not allow GDB to locate the source of the marker, this column will be left blank. d13487 1 a13487 1 _Data_ d13491 2 a13492 1 _Static tracepoints probing the marker_ d13510 1 a13510 1 ‘tstart’ d13515 4 a13518 4 the trace experiment's state. The notes may be arbitrary text, and are especially useful with disconnected tracing in a multi-user context; the notes can explain what the trace is doing, supply user contact information, and so forth. d13520 1 a13520 1 ‘tstop’ d13531 1 a13531 1 ‘tstatus’ d13550 6 a13555 6 disconnects from the target, voluntarily or involuntarily. For commands such as ‘detach’, the debugger will ask what you want to do with the trace. But for unexpected terminations (GDB crash, network outage), it would be unfortunate to lose hard-won trace data, so the variable ‘disconnected-tracing’ lets you decide whether the trace should continue running without GDB. d13557 2 a13558 2 ‘set disconnected-tracing on’ ‘set disconnected-tracing off’ d13560 1 a13560 1 disconnected from the target. Note that ‘detach’ or ‘quit’ will d13565 1 a13565 1 ‘show disconnected-tracing’ d13568 1 d13570 3 a13572 3 still be running; it might have filled the trace buffer in the meantime, or stopped for one of the other reasons. If it is running, it will continue after reconnection. d13585 10 a13594 10 If your target agent supports a “circular trace buffer”, then you can run a trace experiment indefinitely without filling the trace buffer; when space runs out, the agent deletes already-collected trace frames, oldest first, until there is enough room to continue collecting. This is especially useful if your tracepoints are being hit too often, and your trace gets terminated prematurely because the buffer is full. To ask for a circular trace buffer, simply set ‘circular-trace-buffer’ to on. You can set this at any time, including during tracing; if the agent can do it, it will change buffer handling on the fly, otherwise it will not take effect until the next run. d13596 2 a13597 2 ‘set circular-trace-buffer on’ ‘set circular-trace-buffer off’ d13604 1 a13604 1 ‘show circular-trace-buffer’ d13606 4 a13609 3 not match the agent's current buffer handling, nor is it guaranteed to match the setting that might have been in effect during a past run, for instance if you are looking at frames from a trace file. d13611 3 a13613 2 ‘set trace-buffer-size N’ ‘set trace-buffer-size unlimited’ d13617 1 a13617 1 ‘unlimited’ or ‘-1’ to let the target use whatever size it likes. d13620 1 a13620 1 ‘show trace-buffer-size’ d13626 1 a13626 1 starts. Use ‘tstatus’ to get a report of the actual buffer size. d13628 1 a13628 1 ‘set trace-user TEXT’ d13630 1 a13630 1 ‘show trace-user’ d13632 1 a13632 1 ‘set trace-notes TEXT’ d13635 1 a13635 1 ‘show trace-notes’ d13638 1 a13638 1 ‘set trace-stop-notes TEXT’ d13640 1 a13640 1 ‘tstop’ arguments; the set command is convenient way to fix a stop d13643 1 a13643 1 ‘show trace-stop-notes’ d13646 1 d13661 1 a13661 1 • Tracepoint expressions are intended to gather objects (lvalues). d13669 2 a13670 2 • Collection of local variables, either individually or in bulk with ‘$locals’ or ‘$args’, during ‘while-stepping’ may behave d13677 1 a13677 1 where the steps of a ‘while-stepping’ sequence will advance the d13680 1 a13680 1 • Collection of an incompletely-initialized or partially-destroyed d13684 1 a13684 1 • When GDB displays a pointer to character it automatically d13690 2 a13691 2 example, ‘*ptr@@50’ can be used to collect the 50 element array pointed to by ‘ptr’. d13693 1 a13693 1 • It is not possible to collect a complete stack backtrace at a d13696 1 a13696 1 ‘*(unsigned char *)$esp@@300’ (adjust to use the name of the actual d13698 1 a13698 1 of stack you wish to capture). Then the ‘backtrace’ command will d13701 3 a13703 3 frames in the collected stack. Note that if you ask for a block so large that it goes past the bottom of the stack, the target agent may report an error trying to read from an invalid address. d13705 2 a13706 2 • If you do not collect registers at a tracepoint, GDB can infer that the value of ‘$pc’ must be the same as the address of the d13710 2 a13711 2 was inlined), or if it has a ‘while-stepping’ loop. In those cases GDB will warn you that it can't infer ‘$pc’, and default it to d13714 1 d13721 14 a13734 13 After the tracepoint experiment ends, you use GDB commands for examining the trace data. The basic idea is that each tracepoint collects a trace “snapshot” every time it is hit and another snapshot every time it single-steps. All these snapshots are consecutively numbered from zero and go into a buffer, and you can examine them later. The way you examine them is to “focus” on a specific trace snapshot. When the remote stub is focused on a trace snapshot, it will respond to all GDB requests for memory and registers by reading from the buffer which belongs to that snapshot, rather than from _real_ memory or registers of the program being debugged. This means that *all* GDB commands (‘print’, ‘info registers’, ‘backtrace’, etc.) will behave as if we were currently debugging the program state as it was when the tracepoint occurred. Any requests for data that are not in the buffer will fail. d13745 1 a13745 1 13.2.1 ‘tfind N’ d13749 1 a13749 1 ‘tfind N’, which finds trace snapshot number N, counting from zero. If d13752 1 a13752 1 Here are the various forms of using the ‘tfind’ command. d13754 1 a13754 1 ‘tfind start’ d13756 1 a13756 1 ‘tfind 0’ (since 0 is the number of the first snapshot). d13758 1 a13758 1 ‘tfind none’ d13761 2 a13762 2 ‘tfind end’ Same as ‘tfind none’. d13764 1 a13764 1 ‘tfind’ d13768 1 a13768 1 ‘tfind -’ d13772 1 a13772 1 ‘tfind tracepoint NUM’ d13778 1 a13778 1 ‘tfind pc ADDR’ d13784 1 a13784 1 ‘tfind outside ADDR1, ADDR2’ d13788 1 a13788 1 ‘tfind range ADDR1, ADDR2’ d13792 1 a13792 1 ‘tfind line [FILE:]N’ d13797 2 a13798 2 other than the one currently being examined; thus saying ‘tfind line’ repeatedly can appear to have the same effect as stepping d13801 1 a13801 1 The default arguments for the ‘tfind’ commands are specifically d13803 11 a13813 11 instance, ‘tfind’ with no argument selects the next trace snapshot, and ‘tfind -’ with no argument selects the previous trace snapshot. So, by giving one ‘tfind’ command, and then simply hitting repeatedly you can examine all the trace snapshots in order. Or, by saying ‘tfind -’ and then hitting repeatedly you can examine the snapshots in reverse order. The ‘tfind line’ command with no argument selects the snapshot for the next source line executed. The ‘tfind pc’ command with no argument selects the next snapshot with the same program counter (PC) as the current frame. The ‘tfind tracepoint’ command with no argument selects the next trace snapshot collected by the same tracepoint as the current one. d13818 2 a13819 2 interested in. Thus, if we want to examine the PC, FP, and SP registers from each trace frame in the buffer, we can say this: d13840 2 a13841 2 Or, if we want to examine the variable ‘X’ at each source line in the buffer: d13856 1 a13856 1 13.2.2 ‘tdump’ d13909 4 a13912 4 ‘tdump’ works by scanning the tracepoint's current collection actions and printing the value of each expression listed. So ‘tdump’ can fail, if after a run, you change the tracepoint's actions to mention variables that were not collected during the run. d13914 2 a13915 2 Also, for tracepoints with ‘while-stepping’ loops, ‘tdump’ uses the collected value of ‘$pc’ to distinguish between trace frames that were d13919 1 a13919 1 while-stepping loop. However, if ‘$pc’ was not collected, then ‘tdump’ d13927 1 a13927 1 13.2.3 ‘save tracepoints FILENAME’ d13931 4 a13934 4 their actions and passcounts, into a file ‘FILENAME’ suitable for use in a later debugging session. To read the saved tracepoint definitions, use the ‘source’ command (*note Command Files::). The ‘save-tracepoints’ command is a deprecated alias for ‘save tracepoints’ d13942 2 a13943 2 ‘(int) $trace_frame’ The current trace snapshot (a.k.a. “frame”) number, or -1 if no d13946 1 a13946 1 ‘(int) $tracepoint’ d13949 1 a13949 1 ‘(int) $trace_line’ d13952 1 a13952 1 ‘(char []) $trace_file’ d13955 2 a13956 2 ‘(char []) $trace_func’ The name of the function containing ‘$tracepoint’. d13958 2 a13959 2 Note: ‘$trace_file’ is not suitable for use in ‘printf’, use ‘output’ instead. d13984 1 a13984 1 data, via the ‘target tfile’ command. d13986 2 a13987 2 ‘tsave [ -r ] FILENAME’ ‘tsave [-ctf] DIRNAME’ d13992 10 a14001 9 ‘-r’ ("remote") to direct the target to save the data directly into FILENAME in its own filesystem, which may be more efficient if the trace buffer is very large. (Note, however, that ‘target tfile’ can only read from files accessible to the host.) By default, this command will save trace frame in tfile format. You can supply the optional argument ‘-ctf’ to save data in CTF format. The “Common Trace Format” (CTF) is proposed as a trace format that can be shared by multiple debugging and tracing tools. Please go to ‘http://www.efficios.com/ctf’ to get more information. d14003 2 a14004 2 ‘target tfile FILENAME’ ‘target ctf DIRNAME’ d14008 1 a14008 1 experiments. ‘tstatus’ will report the state of the trace run at d14027 1 d14035 1 a14035 1 memory, you can sometimes use “overlays” to work around this problem. d14060 1 a14060 1 these modules “overlays”. Separate the overlays from the main program, d14098 6 a14103 6 copies its code from the larger address space to the instruction address space. Since the overlays shown here all use the same mapped address, only one may be mapped at a time. For a system with a single address space for data and instructions, the diagram would be similar, except that the program variables and heap would share an address space with the main program and the overlay area. d14105 2 a14106 2 An overlay loaded into instruction memory and ready for use is called a “mapped” overlay; its “mapped address” is its address in the d14108 1 a14108 1 in instruction memory is called “unmapped”; its “load address” is its d14110 2 a14111 2 “virtual memory address”, or “VMA”; the load address is also called the “load memory address”, or “LMA”. d14113 10 a14122 8 Unfortunately, overlays are not a completely transparent way to adapt a program to limited instruction memory. They introduce a new set of global constraints you must keep in mind as you design your program: • Before calling or returning to a function in an overlay, your program must make sure that overlay is actually mapped. Otherwise, the call or return will transfer control to the right address, but in the wrong overlay, and your program will probably crash. d14124 1 a14124 1 • If the process of mapping an overlay is expensive on your system, d14128 1 a14128 1 • The executable file you load onto your system must contain each d14133 7 a14139 2 different load and relocation addresses for pieces of your program; see *note (ld.info)Overlay Description::. a14140 3 • The procedure for loading executable files onto your system must be able to load their contents into the larger address space as well as the instruction and data spaces. d14145 1 a14145 1 • If your system has suitable bank switch registers or memory d14151 1 a14151 1 • If your overlays are small enough, you could set aside more than d14154 1 a14154 1 • You can use overlays to manage data, as well as instructions. In d14163 1 d14177 2 a14178 2 GDB's overlay commands all start with the word ‘overlay’; you can abbreviate this as ‘ov’ or ‘ovly’. The commands are: d14180 1 a14180 1 ‘overlay off’ d14186 4 a14189 4 ‘overlay manual’ Enable “manual” overlay debugging. In this mode, GDB relies on you to tell it which overlays are mapped, and which are not, using the ‘overlay map-overlay’ and ‘overlay unmap-overlay’ commands d14192 2 a14193 2 ‘overlay map-overlay OVERLAY’ ‘overlay map OVERLAY’ d14195 2 a14196 2 the object file section containing the overlay. When an overlay is mapped, GDB assumes it can find the overlay's functions and d14201 11 a14211 11 ‘overlay unmap-overlay OVERLAY’ ‘overlay unmap OVERLAY’ Tell GDB that OVERLAY is no longer mapped; OVERLAY must be the name of the object file section containing the overlay. When an overlay is unmapped, GDB assumes it can find the overlay's functions and variables at their load addresses. ‘overlay auto’ Enable “automatic” overlay debugging. In this mode, GDB consults a data structure the overlay manager maintains in the inferior to see which overlays are mapped. For details, see *note Automatic d14214 2 a14215 2 ‘overlay load-target’ ‘overlay load’ d14222 2 a14223 2 ‘overlay list-overlays’ ‘overlay list’ d14227 3 a14229 2 Normally, when GDB prints a code address, it includes the name of the function the address falls in: d14233 1 a14233 1 When overlay debugging is enabled, GDB recognizes code in unmapped d14235 1 a14235 1 around them. For example, if ‘foo’ is a function in an unmapped d14242 2 a14243 1 When ‘foo’'s overlay is mapped, GDB prints the function's name normally: d14252 4 a14255 4 for functions and variables in an overlay, whether or not the overlay is mapped. This allows most GDB commands, like ‘break’ and ‘disassemble’, to work normally, even on unmapped code. However, GDB's breakpoint support has some limitations: d14257 1 a14257 1 • You can set breakpoints in functions in unmapped overlays, as long d14259 5 a14263 4 • GDB can not set hardware or simulator-based breakpoints in unmapped overlays. However, if you set a breakpoint at the end of your overlay manager (and tell GDB which overlays are now mapped, if you are using manual overlay management), GDB will re-set its d14272 6 a14277 5 GDB can automatically track which overlays are mapped and which are not, given some simple co-operation from the overlay manager in the inferior. If you enable automatic overlay debugging with the ‘overlay auto’ command (*note Overlay Commands::), GDB looks in the inferior's memory for certain variables describing the current state of the overlays. d14282 1 a14282 1 ‘_ovly_table’: d14301 1 a14301 1 ‘_novlys’: d14303 2 a14304 1 number of elements in ‘_ovly_table’. d14307 1 a14307 1 for an entry in ‘_ovly_table’ whose ‘vma’ and ‘lma’ members equal the d14309 1 a14309 1 finds a matching entry, it consults the entry's ‘mapped’ member to d14313 6 a14318 6 ‘_ovly_debug_event’. If this function is defined, GDB will silently set a breakpoint there. If the overlay manager then calls this function whenever it has changed the overlay table, this will enable GDB to accurately keep track of which overlays are in program memory, and update any breakpoints that may be set in overlays. This will allow breakpoints to work even if the overlays are kept in ROM or other d14329 5 a14333 5 addresses. To do this, you must write a linker script (*note (ld.info)Overlay Description::). Unfortunately, since linker scripts are specific to a particular host system, target architecture, and target memory layout, this manual cannot provide portable sample code demonstrating GDB's overlay support. d14338 1 a14338 1 ‘gdb/testsuite/gdb.base’: d14340 1 a14340 1 ‘overlays.c’ a14341 11 ‘ovlymgr.c’ A simple overlay manager, used by ‘overlays.c’. ‘foo.c’ ‘bar.c’ ‘baz.c’ ‘grbx.c’ Overlay modules, loaded and used by ‘overlays.c’. ‘d10v.ld’ ‘m32r.ld’ Linker scripts for linking the test program on the ‘d10v-elf’ and ‘m32r-elf’ targets. d14343 15 a14357 1 You can build the test program using the ‘d10v-elf’ GCC d14371 1 a14371 1 the target system for ‘d10v-elf-gcc’ and ‘d10v.ld’. d14381 4 a14384 4 dereferencing a pointer ‘p’ is accomplished by ‘*p’, but in Modula-2, it is accomplished by ‘p^’. Values can also be represented (and displayed) differently. Hex numbers in C appear as ‘0x1ae’, while in Modula-2 they appear as ‘1AEH’. d14390 1 a14390 1 language you use to build expressions is called the “working language”. d14407 2 a14408 2 it automatically, or select it manually yourself. You can use the ‘set language’ command for either purpose. On startup, GDB defaults to d14413 10 a14422 9 In addition to the working language, every source file that GDB knows about has its own working language. For some object file formats, the compiler might indicate which language a particular source file is in. However, most of the time GDB infers the language from the name of the file. The language of a source file controls whether C++ names are demangled--this way ‘backtrace’ can show each frame appropriately for its own language. There is no way to set the language of a source file from within GDB, but you can set the language associated with a filename extension. *Note Displaying the Language: Show. d14425 2 a14426 2 ‘cfront’ or ‘f2c’, that generates C but is written in another language. In that case, make the program use ‘#line’ directives in its C output; d14428 2 a14429 2 original program, and will display that source code, not the generated C code. d14446 4 a14449 4 ‘.ada’ ‘.ads’ ‘.adb’ ‘.a’ d14452 1 a14452 1 ‘.c’ d14455 6 a14460 6 ‘.C’ ‘.cc’ ‘.cp’ ‘.cpp’ ‘.cxx’ ‘.c++’ d14463 1 a14463 1 ‘.d’ d14466 1 a14466 1 ‘.m’ d14469 2 a14470 2 ‘.f’ ‘.F’ d14473 1 a14473 1 ‘.mod’ d14476 2 a14477 2 ‘.s’ ‘.S’ d14494 3 a14496 3 the command ‘set language LANG’, where LANG is the name of a language, such as ‘c’ or ‘modula-2’. For a list of the supported languages, type ‘set language’. d14502 2 a14503 2 different things. For instance, if the current source file were written in C, and GDB was parsing Modula-2, a command such as: d14507 4 a14510 4 might not have the effect you intended. In C, this means to add ‘b’ and ‘c’ and place the result in ‘a’. The result printed would be the value of ‘a’. In Modula-2, this means to compare ‘a’ to the result of ‘b+c’, yielding a ‘BOOLEAN’ value. d14518 2 a14519 2 To have GDB set the working language automatically, use ‘set language local’ or ‘set language auto’. GDB then infers the working language. d14524 2 a14525 2 defined in a source file that does not have a recognized extension), the current working language is not changed, and GDB issues a warning. d14530 1 a14530 1 a different source language. Using ‘set language auto’ in this case d14542 4 a14545 4 ‘show language’ Display the current working language. This is the language you can use with commands such as ‘print’ to build and compute expressions that may involve variables in your program. d14547 1 a14547 1 ‘info frame’ d14553 1 a14553 1 ‘info source’ d14555 2 a14556 2 the Symbol Table: Symbols, to identify the other information listed here. d14562 1 a14562 1 ‘set extension-language EXT LANGUAGE’ d14566 1 a14566 1 ‘info extensions’ d14586 1 a14586 1 evaluation via the ‘print’ command, for example. d14612 2 a14613 2 The second example fails because in C++ the integer constant ‘0x1234’ is not type-compatible with the pointer parameter type. d14617 2 a14618 2 abandon the expression; When type checking is disabled, GDB successfully evaluates expressions like the second example above. d14622 1 a14622 1 does not know how to add an ‘int’ and a ‘struct foo’. These particular d14628 2 a14629 2 ‘set check type on’ ‘set check type off’ d14634 1 a14634 1 ‘show check type’ d14658 3 a14660 3 In many implementations of C, mathematical overflow causes the result to "wrap around" to lower values--for example, if M is the largest integer value, and S is the smallest, then d14662 1 a14662 1 M + 1 ⇒ S d14672 1 a14672 1 ‘set check range auto’ d14677 2 a14678 2 ‘set check range on’ ‘set check range off’ d14685 1 a14685 1 ‘set check range warn’ d14692 1 a14692 1 ‘show check range’ d14704 2 a14705 2 expressions regardless of the language you use: the GDB ‘@@’ and ‘::’ operators, and the ‘{type}addr’ construct (*note Expressions: d14709 6 a14714 6 supported by GDB. These sections are not meant to be language tutorials or references, but serve only as a reference guide to what the GDB expression parser accepts, and what input and output formats should look like for different languages. There are many good books written on each of these languages; please look to these for a language reference or tutorial. d14742 1 a14742 1 GNU ‘g++’, or the HP ANSI C++ compiler (‘aCC’). d14762 1 a14762 1 ‘+’ is defined on numbers, but not on structures. Operators are often d14767 2 a14768 2 • _Integral types_ include ‘int’ with any of its storage-class specifiers; ‘char’; ‘enum’; and, for C++, ‘bool’. d14770 2 a14771 2 • _Floating-point types_ include ‘float’, ‘double’, and ‘long double’ (if supported by the target platform). d14773 1 a14773 1 • _Pointer types_ include all types defined as ‘(TYPE *)’. d14775 1 a14775 1 • _Scalar types_ include all of the above. a14776 2 The following operators are supported. They are listed here in order of increasing precedence: d14778 8 a14785 4 ‘,’ The comma or sequencing operator. Expressions in a comma-separated list are evaluated from left to right, with the result of the entire expression being the last expression evaluated. d14787 1 a14787 1 ‘=’ d14791 9 a14799 9 ‘OP=’ Used in an expression of the form ‘A OP= B’, and translated to ‘A = A OP B’. ‘OP=’ and ‘=’ have the same precedence. The operator OP is any one of the operators ‘|’, ‘^’, ‘&’, ‘<<’, ‘>>’, ‘+’, ‘-’, ‘*’, ‘/’, ‘%’. ‘?:’ The ternary operator. ‘A ? B : C’ can be thought of as: if A then B else C. The argument A should be of an integral type. d14801 1 a14801 1 ‘||’ d14804 1 a14804 1 ‘&&’ d14807 1 a14807 1 ‘|’ d14810 1 a14810 1 ‘^’ d14813 1 a14813 1 ‘&’ d14816 1 a14816 1 ‘==, !=’ d14820 1 a14820 1 ‘<, >, <=, >=’ d14825 1 a14825 1 ‘<<, >>’ d14828 1 a14828 1 ‘@@’ d14832 1 a14832 1 ‘+, -’ d14836 4 a14839 4 ‘*, /, %’ Multiplication, division, and modulus. Multiplication and division are defined on integral and floating-point types. Modulus is defined on integral types. d14841 1 a14841 1 ‘++, --’ d14847 1 a14847 1 ‘*’ d14849 1 a14849 1 as ‘++’. d14851 2 a14852 2 ‘&’ Address operator. Defined on variables. Same precedence as ‘++’. d14854 2 a14855 2 For debugging C++, GDB implements a use of ‘&’ beyond what is allowed in the C++ language itself: you can use ‘&(&REF)’ to d14857 1 a14857 1 ‘&REF’) is stored. d14859 1 a14859 1 ‘-’ d14861 1 a14861 1 precedence as ‘++’. d14863 1 a14863 1 ‘!’ d14865 1 a14865 1 ‘++’. d14867 1 a14867 1 ‘~’ d14869 1 a14869 1 precedence as ‘++’. d14871 1 a14871 1 ‘., ->’ d14873 3 a14875 3 convenience, GDB regards the two as equivalent, choosing whether to dereference a pointer based on the stored type information. Defined on ‘struct’ and ‘union’ data. d14877 1 a14877 1 ‘.*, ->*’ d14880 10 a14889 10 ‘[]’ Array indexing. ‘A[I]’ is defined as ‘*(A+I)’. Same precedence as ‘->’. ‘()’ Function parameter list. Same precedence as ‘->’. ‘::’ C++ scope resolution operator. Defined on ‘struct’, ‘union’, and ‘class’ types. d14891 1 a14891 1 ‘::’ d14893 1 a14893 1 Expressions: Expressions.). Same precedence as ‘::’, above. d14895 3 a14897 3 If an operator is redefined in the user code, GDB usually attempts to invoke the redefined version instead of using the operator's predefined meaning. d14908 4 a14911 4 • Integer constants are a sequence of digits. Octal constants are specified by a leading ‘0’ (i.e. zero), and hexadecimal constants by a leading ‘0x’ or ‘0X’. Constants may also end with a letter ‘l’, specifying that the constant should be treated as a ‘long’ d14914 1 a14914 1 • Floating point constants are a sequence of digits, followed by a d14917 6 a14922 6 ‘e[[+]|-]NNN’, where NNN is another sequence of digits. The ‘+’ is optional for positive exponents. A floating-point constant may also end with a letter ‘f’ or ‘F’, specifying that the constant should be treated as being of the ‘float’ (as opposed to the default ‘double’) type; or with a letter ‘l’ or ‘L’, which specifies a ‘long double’ constant. d14924 1 a14924 1 • Enumerated constants consist of enumerated identifiers, or their d14927 2 a14928 2 • Character constants are a single character surrounded by single quotes (‘'’), or a number--the ordinal value of the corresponding d14930 4 a14933 4 character may be represented by a letter or by “escape sequences”, which are of the form ‘\NNN’, where NNN is the octal representation of the character's ordinal value; or of the form ‘\X’, where ‘X’ is a predefined special character--for example, ‘\n’ for newline. d14936 2 a14937 2 constant with ‘L’, as in C. For example, ‘L'x'’ is the wide form of ‘x’. The target wide character set is used when computing the d14940 2 a14941 2 • String constants are a sequence of character constants surrounded by double quotes (‘"’). Any valid character constant (as described d14943 1 a14943 1 preceded by a backslash, so for instance ‘"a\"b'c"’ is a string of d14947 1 a14947 1 with ‘L’, as in C. The target wide character set is used when d14950 2 a14951 2 • Pointer constants are an integral value. You can also write pointers to constants using the C operator ‘&’. d14953 4 a14956 4 • Array constants are comma-separated lists surrounded by braces ‘{’ and ‘}’; for example, ‘{1,2,3}’ is a three-element array of integers, ‘{{1,2}, {3,4}, {5,6}}’ is a three-by-two array, and ‘{&"hi", &"there", &"fred"}’ is a three-element array of pointers. d14981 1 a14981 1 instance pointer ‘this’ following the same rules as C++. ‘using’ d14998 1 a14998 1 ‘set overload-resolution off’. *Note GDB Features for C++: d15001 1 a15001 1 You must specify ‘set overload-resolution off’ in order to use an d15005 1 a15005 1 The GDB command-completion facility can simplify this; see *note d15015 2 a15016 2 structures. The _address_ of a reference variable is always shown, unless you have specified ‘set print address off’. d15018 1 a15018 1 5. GDB supports the C++ name resolution operator ‘::’--your d15020 1 a15020 1 Since one scope may be defined in another, you can use ‘::’ d15022 1 a15022 1 ‘SCOPE1::SCOPE2::NAME’. GDB also allows resolving name scope by d15036 1 a15036 1 ‘off’ whenever the working language changes to C or C++. This happens d15040 1 a15040 1 source files whose names end with ‘.c’, ‘.C’, or ‘.cc’, etc, and when d15052 3 a15054 3 is used. However, if you turn type checking off, GDB will allow certain non-standard conversions, such as promoting integer constants to pointers. d15066 3 a15068 3 The ‘set print union’ and ‘show print union’ commands apply to the ‘union’ type. When set to ‘on’, any ‘union’ that is inside a ‘struct’ or ‘class’ is also printed. Otherwise, it appears as ‘{...}’. d15070 2 a15071 2 The ‘@@’ operator aids in the debugging of dynamic arrays, formed with pointers and a memory allocation function. *Note Expressions: d15083 1 a15083 1 ‘breakpoint menus’ d15089 1 a15089 1 ‘rbreak REGEX’ d15091 2 a15092 2 setting breakpoints on overloaded functions that are not members of any special classes. *Note Setting Breakpoints: Set Breaks. d15094 3 a15096 3 ‘catch throw’ ‘catch rethrow’ ‘catch catch’ d15100 1 a15100 1 ‘ptype TYPENAME’ d15104 2 a15105 2 ‘info vtbl EXPRESSION.’ The ‘info vtbl’ command can be used to display the virtual method d15110 8 a15117 8 ‘demangle NAME’ Demangle NAME. *Note Symbols::, for a more complete description of the ‘demangle’ command. ‘set print demangle’ ‘show print demangle’ ‘set print asm-demangle’ ‘show print asm-demangle’ d15122 2 a15123 2 ‘set print object’ ‘show print object’ d15127 2 a15128 2 ‘set print vtbl’ ‘show print vtbl’ d15130 2 a15131 2 Print Settings: Print Settings. (The ‘vtbl’ commands do not work on programs compiled with the HP ANSI C++ compiler (‘aCC’).) d15133 1 a15133 1 ‘set overload-resolution on’ d15137 1 a15137 1 argument types, using the standard C++ conversion rules (see *note d15141 1 a15141 1 ‘set overload-resolution off’ d15150 1 a15150 1 ‘show overload-resolution’ d15153 1 a15153 1 ‘Overloaded symbol names’ d15156 1 a15156 1 C++: type ‘SYMBOL(TYPES)’ rather than just SYMBOL. You can also d15161 1 a15161 2 ‘Breakpoints in template functions’ d15163 4 a15166 4 template parameter lists when it encounters a symbol which includes a C++ template. This permits setting breakpoints on families of template functions or functions whose parameters include template types. d15168 1 a15168 1 The ‘-qualified’ flag may be used to override this behavior, d15173 1 a15173 1 finish template parameter lists for you. *Note Command Completion: d15176 1 a15176 2 ‘Breakpoints in functions with ABI tags’ d15180 1 a15180 1 d15188 2 a15189 2 when compiled for the C++11 ABI is marked with the ‘cxx11’ ABI tag, and GDB displays the symbol like this: d15217 1 a15217 1 ‘_Decimal32’, ‘_Decimal64’ and ‘_Decimal128’ types as specified by the d15225 4 a15228 3 Because of a limitation in ‘libdecnumber’, the library used by GDB to manipulate decimal floating point numbers, it is not possible to convert (using a cast, for example) integers wider than 32-bit to decimal float. d15235 2 a15236 2 to inspect ‘_Decimal128’ values stored in floating point registers. See *note PowerPC: PowerPC. for more details. d15245 1 a15245 1 LDC or DMD compilers. Currently GDB supports only one D specific d15255 1 a15255 1 ‘gccgo’ or ‘6g’ compilers. d15259 1 a15259 1 ‘The current Go package’ d15271 1 a15271 1 When stopped inside ‘main’ either of these work: d15276 2 a15277 2 ‘Builtin Go types’ The ‘string’ type is recognized by GDB and is printed as a string. d15279 2 a15280 2 ‘Builtin Go functions’ The GDB expression parser recognizes the ‘unsafe.Sizeof’ function d15283 2 a15284 2 ‘Restrictions on Go expressions’ All Go operators are supported except ‘&^’. The Go ‘_’ "blank d15295 3 a15297 3 options that are useful for debugging Objective-C code. See also *note info classes: Symbols, and *note info selectors: Symbols, for a few more commands specific to Objective-C support. d15313 9 a15321 5 • ‘clear’ • ‘break’ • ‘info line’ • ‘jump’ • ‘list’ d15331 2 a15332 2 example, to set a breakpoint at the ‘create’ instance method of class ‘Fruit’ in the program currently being debugged, enter: d15336 1 a15336 1 To list ten program lines around the ‘initialize’ class method, d15349 1 a15349 1 your program's source files contain more than one ‘create’ method, d15351 1 a15351 1 method. Indicate your choice by number, or type ‘0’ to exit if none d15355 1 a15355 1 ‘makeKeyAndOrderFront:’ method of the ‘NSWindow’ class, enter: d15370 5 a15374 5 will tell GDB to send the ‘hash’ message to OBJECT and print the result. Also, an additional command has been added, ‘print-object’ or ‘po’ for short, which is meant to print the description of an object. However, this command may only work with certain Objective-C libraries that have a particular hook function, ‘_NSPrintForDebugger’, defined. d15396 4 a15399 4 GDB supports the builtin scalar and vector datatypes specified by OpenCL 1.1. In addition the half- and double-precision floating point data types of the ‘cl_khr_fp16’ and ‘cl_khr_fp64’ OpenCL extensions are also known to GDB. d15417 2 a15418 2 GDB supports the operators specified by OpenCL 1.1 for scalar and vector data types. d15429 5 a15433 4 Some Fortran compilers (GNU Fortran 77 and Fortran 95 compilers among them) append an underscore to the names of variables and functions. When you debug programs compiled by those compilers, you will need to refer to variables and functions with a trailing underscore. d15436 2 a15437 2 case-insensitive matching for Fortran symbols. You can change that with the ‘set case-insensitive’ command, see *note Symbols::, for the d15453 5 a15457 5 In Fortran the primitive data-types have an associated ‘KIND’ type parameter, written as ‘TYPE*KINDPARAM’, ‘TYPE*KINDPARAM’, or in the GDB-only dialect ‘TYPE_KINDPARAM’. A concrete example would be ‘‘Real*4’’, ‘‘Real(kind=4)’’, and ‘‘Real_4’’. The kind of a type can be retrieved by using the intrinsic function ‘KIND’, see *note Fortran d15460 1 a15460 1 Generally, the actual implementation of the ‘KIND’ type parameter is d15462 1 a15462 1 accordance with its use in the GNU ‘gfortran’ compiler. Here, the kind d15464 2 a15465 2 ‘Integer*4’ or ‘Integer(kind=4)’ would be an integer type occupying 4 bytes of memory. An exception to this rule is the ‘Complex’ type for d15467 2 a15468 2 size of each of the two ‘Real’'s it is composed of. A ‘Complex*4’ would thus consist of two ‘Real*4’s and occupy 8 bytes of memory. d15470 5 a15474 5 For every type there is also a default kind associated with it, e.g. ‘Integer’ in GDB will internally be an ‘Integer*4’ (see the table below for default types). The default types are the same as in GNU compilers but note, that the GNU default types can actually be changed by compiler flags such as ‘-fdefault-integer-8’ and ‘-fdefault-real-8’. d15479 15 a15493 14 ‘Integer’ ‘Integer*1’, ‘Integer*2’, ‘Integer*4’, ‘Integer*8’, and ‘Integer’ = ‘Integer*4’. ‘Logical’ ‘Logical*1’, ‘Logical*2’, ‘Logical*4’, ‘Logical*8’, and ‘Logical’ = ‘Logical*4’. ‘Real’ ‘Real*4’, ‘Real*8’, ‘Real*16’, and ‘Real’ = ‘Real*4’. ‘Complex’ ‘Complex*4’, ‘Complex*8’, ‘Complex*16’, and ‘Complex’ = ‘Complex*4’. d15502 1 a15502 1 ‘+’ is defined on numbers, but not on characters or other non- d15505 1 a15505 1 ‘**’ d15509 1 a15509 1 ‘:’ d15513 7 a15519 6 ‘%’ The access component operator. Normally used to access elements in derived types. Also suitable for unions. As unions aren't part of regular Fortran, this can only happen when accessing a register that uses a gdbarch-defined union type. ‘::’ d15530 3 a15532 3 Fortran provides a large set of intrinsic procedures. GDB implements an incomplete subset of those procedures and their overloads. Some of these procedures take an optional ‘KIND’ parameter, see *note Fortran d15535 1 a15535 1 ‘ABS(A)’ d15537 1 a15537 1 supported for ‘Complex’ arguments. d15539 1 a15539 1 ‘ALLOCATE(ARRAY)’ d15542 1 a15542 1 ‘ASSOCIATED(POINTER [, TARGET])’ d15546 1 a15546 1 ‘CEILING(A [, KIND])’ d15549 1 a15549 1 ‘Integer(KIND)’. d15551 1 a15551 1 ‘CMPLX(X [, Y [, KIND]])’ d15554 4 a15557 4 component. If Y is not present then the imaginary component is set to ‘0.0’ except if X itself is of ‘Complex’ type. The optional parameter KIND specifies the kind of the return type ‘Complex(KIND)’. d15559 1 a15559 1 ‘FLOOR(A [, KIND])’ d15562 1 a15562 1 ‘Integer(KIND)’. d15564 2 a15565 2 ‘KIND(A)’ Returns the kind value of the argument A, see *note Fortran d15568 4 a15571 4 ‘LBOUND(ARRAY [, DIM [, KIND]])’ Returns the lower bounds of an ARRAY, or a single lower bound along the DIM dimension if present. The optional parameter KIND specifies the kind of the return type ‘Integer(KIND)’. d15573 2 a15574 2 ‘LOC(X)’ Returns the address of X as an ‘Integer’. d15576 1 a15576 1 ‘MOD(A, P)’ d15579 1 a15579 1 ‘MODULO(A, P)’ d15582 2 a15583 2 ‘RANK(A)’ Returns the rank of a scalar or array (scalars have rank ‘0’). d15585 2 a15586 2 ‘SHAPE(A)’ Returns the shape of a scalar or array (scalars have shape ‘()’). d15588 1 a15588 1 ‘SIZE(ARRAY[, DIM [, KIND]])’ d15592 6 a15597 1 ‘Integer(KIND)’. a15598 4 ‘UBOUND(ARRAY [, DIM [, KIND]])’ Returns the upper bounds of an ARRAY, or a single upper bound along the DIM dimension if present. The optional parameter KIND specifies the kind of the return type ‘Integer(KIND)’. d15609 2 a15610 2 ‘info common [COMMON-NAME]’ This command prints the values contained in the Fortran ‘COMMON’ d15612 6 a15617 4 all ‘COMMON’ blocks visible at the current program location are printed. ‘set fortran repack-array-slices [on|off]’ ‘show fortran repack-array-slices’ d15635 1 a15635 1 The default for this setting is ‘off’. d15644 3 a15646 2 nested functions does not currently work. GDB does not support entering expressions, printing values, or similar features using Pascal syntax. d15648 1 a15648 1 The Pascal-specific command ‘set print pascal_static-members’ d15658 4 a15661 4 GDB supports the Rust Programming Language (https://www.rust-lang.org/). Type- and value-printing, and expression parsing, are reasonably complete. However, there are a few peculiarities and holes to be aware of. d15663 1 a15663 1 • Linespecs (*note Location Specifications::) are never relative to d15665 1 a15665 1 namespace of crates, somewhat similar to the way ‘extern crate’ d15669 2 a15670 2 ‘A’, module ‘B’, then ‘break B::f’ will attempt to set a breakpoint in a function named ‘f’ in a crate named ‘B’. d15673 1 a15673 1 items using ‘self::’ or ‘super::’. d15675 1 a15675 1 • Because GDB implements Rust name-lookup semantics in expressions, d15677 2 a15678 2 example, if GDB is stopped at a breakpoint in the crate ‘K’, then ‘print ::x::y’ will try to find the symbol ‘K::x::y’. d15681 2 a15682 2 when debugging, GDB provides the ‘extern’ extension to circumvent this. To use the extension, just put ‘extern’ before a path d15685 2 a15686 2 In the above example, if you wanted to refer to the symbol ‘y’ in the crate ‘x’, you would use ‘print extern x::y’. d15688 2 a15689 2 • The Rust expression evaluator does not support "statement-like" expressions such as ‘if’ or ‘match’, or lambda expressions. d15691 1 a15691 1 • Tuple expressions are not implemented. d15693 2 a15694 2 • The Rust expression evaluator does not currently implement the ‘Drop’ trait. Objects that may be created by the evaluator will d15697 1 a15697 1 • GDB does not implement type inference for generics. In order to d15701 1 a15701 1 • GDB currently uses the C++ demangler for Rust. In most cases this d15704 1 a15704 1 results. This happens because Rust requires the ‘::’ operator d15706 2 a15707 6 GDB might provide a completion like ‘crate::f’, where the parser would require ‘crate::f::’. • As of this writing, the Rust compiler (version 1.8) has a few holes in the debugging information it generates. These holes prevent certain features from being implemented by GDB: d15709 4 a15712 1 • Method calls cannot be made via traits. d15714 1 a15714 1 • Operator overloading is not implemented. d15716 2 a15717 2 • When debugging in a monomorphized function, you cannot use the generic type names. d15719 1 a15719 1 • The type ‘Self’ is not available. d15721 1 a15721 1 • ‘use’ statements are not available, so some names may not be d15745 1 a15745 1 * M2 Scope:: The scope operators ‘::’ and ‘.’ d15755 3 a15757 3 ‘+’ is defined on numbers, but not on structures. Operators are often defined on groups of types. For the purposes of Modula-2, the following definitions hold: d15759 1 a15759 1 • _Integral types_ consist of ‘INTEGER’, ‘CARDINAL’, and their d15762 1 a15762 1 • _Character types_ consist of ‘CHAR’ and its subranges. d15764 1 a15764 1 • _Floating-point types_ consist of ‘REAL’. d15766 1 a15766 1 • _Pointer types_ consist of anything declared as ‘POINTER TO TYPE’. d15768 1 a15768 1 • _Scalar types_ consist of all of the above. d15770 1 a15770 1 • _Set types_ consist of ‘SET’ and ‘BITSET’ types. d15772 1 a15772 1 • _Boolean types_ consist of ‘BOOLEAN’. d15774 2 a15775 2 The following operators are supported, and appear in order of increasing precedence: d15777 1 a15777 1 ‘,’ d15780 2 a15781 2 ‘:=’ Assignment. The value of VAR ‘:=’ VALUE is VALUE. d15783 1 a15783 1 ‘<, >’ d15787 1 a15787 1 ‘<=, >=’ d15789 2 a15790 2 floating-point and enumerated types, or set inclusion on set types. Same precedence as ‘<’. d15792 1 a15792 1 ‘=, <>, #’ d15794 2 a15795 2 types. Same precedence as ‘<’. In GDB scripts, only ‘<>’ is available for inequality, since ‘#’ conflicts with the script d15798 1 a15798 1 ‘IN’ d15800 1 a15800 1 members. Same precedence as ‘<’. d15802 1 a15802 1 ‘OR’ d15805 1 a15805 1 ‘AND, &’ d15808 1 a15808 1 ‘@@’ d15812 1 a15812 1 ‘+, -’ d15816 1 a15816 1 ‘*’ d15820 1 a15820 1 ‘/’ d15822 1 a15822 1 set types. Same precedence as ‘*’. d15824 1 a15824 1 ‘DIV, MOD’ d15826 1 a15826 1 precedence as ‘*’. d15828 2 a15829 2 ‘-’ Negative. Defined on ‘INTEGER’ and ‘REAL’ data. d15831 1 a15831 1 ‘^’ d15834 1 a15834 1 ‘NOT’ d15836 1 a15836 1 ‘^’. d15838 3 a15840 3 ‘.’ ‘RECORD’ field selector. Defined on ‘RECORD’ data. Same precedence as ‘^’. d15842 2 a15843 2 ‘[]’ Array indexing. Defined on ‘ARRAY’ data. Same precedence as ‘^’. d15845 3 a15847 3 ‘()’ Procedure argument list. Defined on ‘PROCEDURE’ objects. Same precedence as ‘^’. d15849 1 a15849 1 ‘::, .’ d15853 2 a15854 2 supported, so GDB treats the use of the operator ‘IN’, or the use of operators ‘+’, ‘-’, ‘*’, ‘/’, ‘=’, , ‘<>’, ‘#’, ‘<=’, and ‘>=’ d15867 1 a15867 1 represents an ‘ARRAY’ variable. d15870 1 a15870 1 represents a ‘CHAR’ constant or variable. d15877 2 a15878 2 the same function with the metavariable S. The type of S should be ‘SET OF MTYPE’ (where MTYPE is the type of M). d15900 1 a15900 1 ‘ABS(N)’ d15903 1 a15903 1 ‘CAP(C)’ d15907 1 a15907 1 ‘CHR(I)’ d15910 1 a15910 1 ‘DEC(V)’ d15914 1 a15914 1 ‘DEC(V,I)’ d15918 1 a15918 1 ‘EXCL(M,S)’ d15921 1 a15921 1 ‘FLOAT(I)’ d15924 1 a15924 1 ‘HIGH(A)’ d15927 1 a15927 1 ‘INC(V)’ d15931 1 a15931 1 ‘INC(V,I)’ d15935 1 a15935 1 ‘INCL(M,S)’ d15939 1 a15939 1 ‘MAX(T)’ d15942 1 a15942 1 ‘MIN(T)’ d15945 1 a15945 1 ‘ODD(I)’ d15948 1 a15948 1 ‘ORD(X)’ d15955 3 a15957 3 ‘SIZE(X)’ Returns the size of its argument. The argument X can be a variable or a type. d15959 1 a15959 1 ‘TRUNC(R)’ d15962 3 a15964 3 ‘TSIZE(X)’ Returns the size of its argument. The argument X can be a variable or a type. d15966 1 a15966 1 ‘VAL(T,I)’ d15969 2 a15970 2 _Warning:_ Sets and their operations are not yet supported, so GDB treats the use of procedures ‘INCL’ and ‘EXCL’ as an error. d15981 1 a15981 1 • Integer constants are simply a sequence of digits. When used in an d15984 1 a15984 1 a trailing ‘H’, and octal integers by a trailing ‘B’. d15986 1 a15986 1 • Floating point constants appear as a sequence of digits, followed d15988 2 a15989 2 exponent can then be specified, in the form ‘E[+|-]NNN’, where ‘[+|-]NNN’ is the desired exponent. All of the digits of the d15992 2 a15993 2 • Character constants consist of a single character enclosed by a pair of like quotes, either single (‘'’) or double (‘"’). They may d15995 1 a15995 1 usually) followed by a ‘C’. d15997 2 a15998 2 • String constants consist of a sequence of characters enclosed by a pair of like quotes, either single (‘'’) or double (‘"’). Escape d16003 1 a16003 1 • Enumerated constants consist of an enumerated identifier. d16005 1 a16005 1 • Boolean constants consist of the identifiers ‘TRUE’ and ‘FALSE’. d16007 1 a16007 1 • Pointer constants consist of integral values only. d16009 1 a16009 1 • Set constants are not yet supported. d16019 4 a16022 3 enumerated types, subrange types and base types. You can also print the contents of variables declared using these type. This section gives a number of simple source code examples together with sample GDB sessions. d16030 2 a16031 2 and you can request GDB to interrogate the type and value of ‘r’ and ‘s’. d16042 1 a16042 1 Likewise if your source code declares ‘s’ as: d16047 1 a16047 1 then you may query the type of ‘s’ by: d16052 2 a16053 2 Note that at present you cannot interactively manipulate set expressions using the debugger. d16067 1 a16067 1 arrays have a lower bound of zero and not ‘-10’ as in the example above. d16079 2 a16080 2 The GDB interaction shows how you can query the data type and value of a variable. d16087 3 a16089 3 In this example a Modula-2 array is declared and its contents displayed. Observe that the contents are written in the same way as their ‘C’ counterparts. d16101 2 a16102 2 The Modula-2 language interface to GDB also understands pointer types as shown in this example: d16110 1 a16110 1 and you can request that GDB describes the type of ‘s’. d16130 1 a16130 1 and you can ask GDB to describe the type of ‘s’ as shown below. d16146 3 a16148 2 default to ‘on’ whenever the working language changes to Modula-2. This happens regardless of whether you or GDB selected the working language. d16151 1 a16151 1 code compiled from a file whose name ends with ‘.mod’ sets the working d16164 1 a16164 1 • Unlike in standard Modula-2, pointer constants can be formed by d16168 2 a16169 2 through direct assignment to another pointer variable or expression that returned a pointer.) d16171 1 a16171 1 • C escape sequences can be used in strings and characters to d16174 1 a16174 1 are printed using the ‘CHR(NNN)’ format. d16176 1 a16176 1 • The assignment operator (‘:=’) returns the value of its right-hand d16179 1 a16179 1 • All built-in procedures both modify _and_ return their argument. d16192 2 a16193 2 • They are of types that have been declared equivalent via a ‘TYPE T1 = T2’ statement d16195 1 a16195 1 • They have been declared on the same line. (Note: This is true of d16208 1 a16208 1 15.4.9.8 The Scope Operators ‘::’ and ‘.’ d16212 1 a16212 1 (‘.’) and the GDB scope operator (‘::’). The two have similar syntax: d16218 2 a16219 2 where SCOPE is the name of a module or a procedure, MODULE the name of a module, and ID is any declared identifier within your program, except d16222 4 a16225 3 Using the ‘::’ operator makes GDB search the scope specified by SCOPE for the identifier ID. If it is not found in the specified scope, then GDB searches all scopes enclosing the one specified by SCOPE. d16227 1 a16227 1 Using the ‘.’ operator makes GDB search the current scope for the d16240 4 a16243 4 Five subcommands of ‘set print’ and ‘show print’ apply specifically to C and C++: ‘vtbl’, ‘demangle’, ‘asm-demangle’, ‘object’, and ‘union’. The first four apply to C++, and the last to the C ‘union’ type, which has no direct analogue in Modula-2. d16245 1 a16245 1 The ‘@@’ operator (*note Expressions: Expressions.), while available d16247 1 a16247 1 the debugging of “dynamic arrays”, which cannot be created in Modula-2 d16249 1 a16249 1 by an integral constant, the construct ‘{TYPE}ADREXP’ is still useful. d16251 2 a16252 2 In GDB scripts, the Modula-2 inequality operator ‘#’ is interpreted as the beginning of a comment. Use ‘<>’ instead. d16293 1 a16293 1 • That GDB should provide basic literals and access to operations for d16296 2 a16297 2 subprograms written into the program (which therefore may be called from GDB). d16299 1 a16299 1 • That type safety and strict adherence to Ada language restrictions d16302 1 a16302 1 • That brevity is important to the GDB user. d16311 2 a16312 2 program. As for other languages, it will enter Ada mode when stopped in a program that was translated from an Ada source file. d16314 2 a16315 2 While in Ada mode, you may use '--' for comments. This is useful mostly for documenting command files. The standard GDB comment (‘#’) d16327 1 a16327 1 • Only a subset of the attributes are supported: d16329 2 a16330 2 − 'First, 'Last, and 'Length on array objects (not on types and subtypes). d16332 1 a16332 1 − 'Min and 'Max. d16334 1 a16334 1 − 'Pos and 'Val. d16336 1 a16336 1 − 'Tag. d16338 2 a16339 2 − 'Range on array objects (not subtypes), but only as the right operand of the membership (‘in’) operator. d16341 1 a16341 1 − 'Access, 'Unchecked_Access, and 'Unrestricted_Access (a GNAT d16344 1 a16344 1 − 'Address. d16346 1 a16346 1 • The names in ‘Characters.Latin_1’ are not available. d16348 8 a16355 8 • Equality tests (‘=’ and ‘/=’) on arrays test for bitwise equality of representations. They will generally work correctly for strings and arrays whose elements have integer or enumeration types. They may not work correctly for arrays whose element types have user-defined equality, for arrays of real values (in particular, IEEE-conformant floating point, because of negative zeroes and NaNs), and for arrays whose elements contain unused bits with indeterminate values. d16357 2 a16358 2 • The other component-by-component array operations (‘and’, ‘or’, ‘xor’, ‘not’, and relational tests other than equality) are not d16361 1 a16361 1 • There is limited support for array and record aggregates. They are d16377 1 a16377 1 ‘A_Rec’ declared to have a type such as: d16384 1 a16384 1 you can assign a value with a different size of ‘Vals’ with two d16392 2 a16393 2 components of an array or record aggregate (such as the ‘Len’ component in the assignment to ‘A_Rec’ above); they will retain d16399 1 a16399 1 • Calls to dispatching subprograms are not implemented. d16401 6 a16406 6 • The overloading algorithm is much more limited (i.e., less selective) than that of real Ada. It makes only limited use of the context in which a subexpression appears to resolve its meaning, and it is much looser in its rules for allowing type matches. As a result, some function calls will be ambiguous, and the user will be asked to choose the proper resolution. d16408 1 a16408 1 • The ‘new’ operator is not implemented. d16410 1 a16410 1 • Entry calls are not implemented. d16412 1 a16412 1 • Aside from printing, arithmetic operations on the native VAX d16415 1 a16415 1 • It is not possible to slice a packed array. d16417 5 a16421 5 • The names ‘True’ and ‘False’, when not part of a qualified name, are interpreted as if implicitly prefixed by ‘Standard’, regardless of context. Should your program redefine these names in a package or procedure (at best a dubious practice), you will have to use fully qualified names to access their new definitions. d16423 1 a16423 1 • Based real literals are not implemented. d16434 1 a16434 1 • If the expression E is a variable residing in memory (typically a d16436 1 a16436 1 ‘E@@N’ displays the values of E and the N-1 adjacent variables d16438 4 a16441 4 generally not necessary, since its prime use is in displaying parts of an array, and slicing will usually do this in Ada. However, there are occasional uses when debugging programs in which certain debugging information has been optimized away. d16443 1 a16443 1 • ‘B::VAR’ means "the variable named VAR that appears in function or d16447 1 a16447 1 • The expression ‘{TYPE} ADDR’ means "the variable of type TYPE that d16450 1 a16450 1 • A name starting with ‘$’ is a convenience variable (*note d16456 2 a16457 2 • The assignment statement is allowed as an expression, returning its right-hand operand as its value. Thus, you may enter d16462 1 a16462 1 • The semicolon is allowed as an "operator," returning as its value d16469 6 a16474 6 • An extension to based literals can be used to specify the exact byte contents of a floating-point literal. After the base, you can use from zero to two ‘l’ characters, followed by an ‘f’. The number of ‘l’ characters controls the width of the resulting real constant: zero means ‘Float’ is used, one means ‘Long_Float’, and two means ‘Long_Long_Float’. d16479 1 a16479 1 • Rather than use catenation and symbolic character names to d16482 1 a16482 1 sequence of characters of the form ‘["XX"]’ within a string or d16484 2 a16485 2 encoding is XX in hexadecimal. The sequence of characters ‘["""]’ also denotes a single quotation mark in strings. For example, d16487 1 a16487 1 contains an ASCII newline character (‘Ada.Characters.Latin_1.LF’) d16490 1 a16490 1 • The subtype used as a prefix for the attributes 'Pos, 'Min, and d16496 1 a16496 1 • When printing arrays, GDB uses positional notation when the array d16504 1 a16504 1 ‘=>’ clause. d16506 1 a16506 1 • You may abbreviate attributes in expressions with any unique, d16509 1 a16509 1 place of a'length. d16511 1 a16511 1 • Since Ada is case-insensitive, the debugger normally maps d16519 1 a16519 1 • Printing an object of class-wide type or dereferencing an d16525 1 d16536 2 a16537 2 use of context, preferring procedures to functions in the context of the ‘call’ command, and functions to procedures elsewhere. d16551 1 a16551 1 evaluation (type ‘0’ and press ) or to continue evaluation with a d16557 1 a16557 1 ‘set ada print-signatures’ d16559 1 a16559 1 overloads selection menus. It is ‘on’ by default. *Note d16562 1 a16562 1 ‘show ada print-signatures’ d16567 1 d16577 2 a16578 2 ‘adainit’. To run your program up to the beginning of elaboration, simply use the following two commands: ‘tbreak adainit’ and ‘run’. d16588 3 a16590 3 ‘info exceptions’ ‘info exceptions REGEXP’ The ‘info exceptions’ command allows you to list all Ada exceptions d16612 1 a16612 1 an exception is raised. For more details, see *note Set Catchpoints::. d16623 3 a16625 3 ‘info tasks’ This command shows a list of current Ada tasks, as in the following example: a16633 1 d16637 1 a16637 1 ID d16640 1 a16640 1 TID d16643 1 a16643 1 P-ID d16646 1 a16646 1 Pri d16649 1 a16649 1 State d16652 14 a16665 13 ‘Unactivated’ The task has been created but has not been activated. It cannot be executing. ‘Runnable’ The task is not blocked for any reason known to Ada. (It may be waiting for a mutex, though.) It is conceptually "executing" in normal mode. ‘Terminated’ The task is terminated, in the sense of ARM 9.3 (5). Any dependents that were waiting on terminate alternatives have been awakened and have terminated themselves. d16667 1 a16667 1 ‘Child Activation Wait’ d16671 1 a16671 1 ‘Accept or Select Term’ d16675 1 a16675 1 ‘Waiting on entry call’ d16678 1 a16678 1 ‘Async Select Wait’ d16682 1 a16682 1 ‘Delay Sleep’ d16686 1 a16686 1 ‘Child Termination Wait’ d16692 1 a16692 1 ‘Wait Child in Term Alt’ d16696 1 a16696 1 ‘Asynchronous Hold’ d16698 1 a16698 1 ‘Ada.Asynchronous_Task_Control.Hold_Task’. d16700 1 a16700 1 ‘Activating’ d16703 1 a16703 1 ‘Selective Wait’ d16706 1 a16706 1 ‘Accepting RV with TASKNO’ d16709 1 a16709 1 ‘Waiting on RV with TASKNO’ d16713 1 a16713 1 Name d16716 2 a16717 1 ‘info task TASKNO’ d16733 1 a16733 1 ‘task’ d16743 2 a16744 2 ‘task TASKNO’ This command is like the ‘thread THREAD-ID’ command (*note d16762 12 a16773 11 ‘task apply [TASK-ID-LIST | all] [FLAG]... COMMAND’ The ‘task apply’ command is the Ada tasking analogue of ‘thread apply’ (*note Threads::). It allows you to apply the named COMMAND to one or more tasks. Specify the tasks that you want affected using a list of task IDs, or specify ‘all’ to apply to all tasks. The FLAG arguments control what output to produce and how to handle errors raised when applying COMMAND to a task. FLAG must start with a ‘-’ directly followed by one letter in ‘qcs’. If several flags are provided, they must be given individually, such as ‘-c -q’. d16777 1 a16777 1 COMMAND will abort ‘task apply’. The following flags can be used d16780 3 a16782 3 ‘-c’ The flag ‘-c’, which stands for ‘continue’, causes any errors in COMMAND to be displayed, and the execution of ‘task apply’ d16784 9 a16792 7 ‘-s’ The flag ‘-s’, which stands for ‘silent’, causes any errors or empty output produced by a COMMAND to be silently ignored. That is, the execution continues, but the task information and errors are not printed. ‘-q’ The flag ‘-q’ (‘quiet’) disables printing the task d16795 1 a16795 1 Flags ‘-c’ and ‘-s’ cannot be used together. d16797 3 a16799 3 ‘break LOCSPEC task TASKNO’ ‘break LOCSPEC task TASKNO if ...’ These commands are like the ‘break ... thread ...’ command (*note d16803 1 a16803 1 Use the qualifier ‘task TASKNO’ with a breakpoint command to d16807 1 a16807 1 column of the ‘info tasks’ display. d16809 1 a16809 1 If you do not specify ‘task TASKNO’ when you set a breakpoint, the d16812 3 a16814 3 You can use the ‘task’ qualifier on conditional breakpoints as well; in this case, place ‘task TASKNO’ before the breakpoint condition (before the ‘if’). d16854 1 a16854 1 privileges, using the command ‘"set write on"’ (*note Patching::). d16864 1 a16864 1 The “Ravenscar Profile” is a subset of the Ada tasking features, d16868 1 a16868 1 ‘set ravenscar task-switching on’ d16872 1 a16872 1 ‘set ravenscar task-switching off’ d16880 1 a16880 1 ‘show ravenscar task-switching’ d16884 1 d16892 1 a16892 1 the output of ‘info threads’: d16903 4 a16906 4 One known limitation of the Ravenscar support in GDB is that it isn't currently possible to single-step through the runtime initialization sequence. If you need to debug this code, you should use ‘set ravenscar task-switching off’. d16918 1 a16918 1 ‘set ada source-charset CHARSET’ d16920 1 a16920 1 supported by GNAT. Because this setting affects the decoding of d16923 1 a16923 1 ‘ISO-8859-1’, because that is also GNAT's default. d16925 1 a16925 1 ‘show ada source-charset’ d16934 4 a16937 4 Besides the omissions listed previously (*note Omissions from Ada::), we know of several problems with and limitations of Ada mode in GDB, some of which will be fixed with planned future releases of the debugger and the GNU Ada compiler. d16939 1 a16939 1 • Static constants that the compiler chooses not to materialize as d16942 2 a16943 2 • Named parameter associations in function argument lists are ignored (the argument lists are treated as positional). d16945 1 a16945 1 • Many useful library packages are currently invisible to the d16948 3 a16950 3 • Fixed-point arithmetic, conversions, input, and output is carried out using floating-point arithmetic, and may give results that only approximate those on the host machine. d16952 1 a16952 1 • The GNAT compiler never generates the prefix ‘Standard’ for any of d16954 9 a16962 9 this: it will strip the prefix from names when you use it, and will never look for a name you have so qualified among local symbols, nor match against symbols in other packages or subprograms. If you have defined entities anywhere in your program other than parameters and local variables whose simple names match names in ‘Standard’, GNAT's lack of qualification here can cause confusion. When this happens, you can usually resolve the confusion by qualifying the problematic names with package ‘Standard’ explicitly. d16965 5 a16969 4 information, resulting in the debugger incorrectly printing the value of affected entities. In some cases, the debugger is able to work around an issue automatically. In other cases, the debugger is able to work around the issue, but the work-around has to be specifically enabled. d16971 1 a16971 1 ‘set ada trust-PAD-over-XVS on’ d16973 3 a16975 3 the value of Ada entities, particularly when ‘PAD’ and ‘PAD___XVS’ types are involved (see ‘ada/exp_dbug.ads’ in the GCC sources for a complete description of the encoding used by the GNAT compiler). d16978 9 a16986 7 ‘set ada trust-PAD-over-XVS off’ This is related to the encoding using by the GNAT compiler. If GDB sometimes prints the wrong value for certain entities, changing ‘ada trust-PAD-over-XVS’ to ‘off’ activates a work-around which may fix the issue. It is always safe to set ‘ada trust-PAD-over-XVS’ to ‘off’, but this incurs a slight performance penalty, so it is recommended to leave this setting to ‘on’ unless necessary. d16989 2 a16990 2 number of conventions known as the ‘GNAT Encoding’, all documented in ‘gcc/ada/exp_dbug.ads’ in the GCC sources. This encoding describes how d16992 1 a16992 1 particular, this convention makes use of “descriptive types”, which are d16997 2 a16998 2 types available in Ada. Since DWARF allows us to express nearly all Ada features, the long-term goal is to slowly replace these descriptive d17004 1 a17004 1 ‘maintenance ada set ignore-descriptive-types [on|off]’ d17006 1 a17006 1 default is not to ignore descriptives types (‘off’). d17008 1 a17008 1 ‘maintenance ada show ignore-descriptive-types’ d17011 1 d17018 6 a17023 6 In addition to the other fully-supported programming languages, GDB also provides a pseudo-language, called ‘minimal’. It does not represent a real programming language, but provides a set of capabilities close to what the C or assembly languages provide. This should allow most simple operations to be performed while debugging an application that uses a language currently not supported by GDB. d17025 1 a17025 1 If the language is set to ‘auto’, GDB will automatically select this d17047 2 a17048 2 typical file name, like ‘foo.c’, as the three words ‘foo’ ‘.’ ‘c’. To allow GDB to recognize ‘foo.c’ as a single symbol, enclose it in single d17053 1 a17053 1 looks up the value of ‘x’ in the scope of the file ‘foo.c’. d17055 3 a17057 3 ‘set case-sensitive on’ ‘set case-sensitive off’ ‘set case-sensitive auto’ d17060 6 a17065 6 Occasionally, you may wish to control that. The command ‘set case-sensitive’ lets you do that by specifying ‘on’ for case-sensitive matches or ‘off’ for case-insensitive ones. If you specify ‘auto’, case sensitivity is reset to the default suitable for the source language. The default is case-sensitive matches for all languages except for Fortran, for which the default is d17068 1 a17068 1 ‘show case-sensitive’ d17072 9 a17080 8 ‘set print type methods’ ‘set print type methods on’ ‘set print type methods off’ Normally, when GDB prints a class, it displays any methods declared in that class. You can control this behavior either by passing the appropriate flag to ‘ptype’, or using ‘set print type methods’. Specifying ‘on’ will cause GDB to display the methods; this is the default. Specifying ‘off’ will cause GDB to omit the methods. d17082 1 a17082 1 ‘show print type methods’ d17086 2 a17087 2 ‘set print type nested-type-limit LIMIT’ ‘set print type nested-type-limit unlimited’ d17089 1 a17089 1 show. A LIMIT of ‘unlimited’ or ‘-1’ will show all nested d17093 1 a17093 1 ‘show print type nested-type-limit’ d17097 11 a17107 12 ‘set print type typedefs’ ‘set print type typedefs on’ ‘set print type typedefs off’ Normally, when GDB prints a class, it displays any typedefs defined in that class. You can control this behavior either by passing the appropriate flag to ‘ptype’, or using ‘set print type typedefs’. Specifying ‘on’ will cause GDB to display the typedef definitions; this is the default. Specifying ‘off’ will cause GDB to omit the typedef definitions. Note that this controls whether the typedef definition itself is printed, not whether typedef names are substituted when printing other types. d17109 1 a17109 1 ‘show print type typedefs’ d17113 3 a17115 4 ‘set print type hex’ ‘set print type hex on’ ‘set print type hex off’ d17118 2 a17119 2 the other either by passing the appropriate flag to ‘ptype’, or by using the ‘set print type hex’ command. d17121 1 a17121 1 ‘show print type hex’ d17125 1 a17125 1 ‘info address SYMBOL’ d17131 1 a17131 1 Note the contrast with ‘print &SYMBOL’, which does not work at all d17135 4 a17138 4 ‘info symbol ADDR’ Print the name of a symbol which is stored at the address ADDR. If no symbol is stored exactly at ADDR, GDB prints the nearest symbol and an offset from it: d17143 3 a17145 2 This is the opposite of the ‘info address’ command. You can use it to find out the name of a variable or a function given its address. d17155 1 a17155 1 ‘demangle [-l LANGUAGE] [--] NAME’ d17160 1 a17160 1 The ‘--’ option specifies the end of options, and is useful when d17163 2 a17164 2 The parameter ‘demangle-style’ specifies how to interpret the kind of mangling used. *Note Print Settings::. d17166 1 a17166 1 ‘whatis[/FLAGS] [ARG]’ d17168 2 a17169 2 name of a data type. With no argument, print the data type of ‘$’, the last value in the value history. d17175 1 a17175 1 If ARG is a variable or an expression, ‘whatis’ prints its literal d17177 10 a17186 10 using a ‘typedef’, ‘whatis’ will _not_ print the data type underlying the ‘typedef’. If the type of the variable or the expression is a compound data type, such as ‘struct’ or ‘class’, ‘whatis’ never prints their fields or methods. It just prints the ‘struct’/‘class’ name (a.k.a. its “tag”). If you want to see the members of such a compound data type, use ‘ptype’. If ARG is a type name that was defined using ‘typedef’, ‘whatis’ “unrolls” only one level of that ‘typedef’. Unrolling means that ‘whatis’ will show the underlying type used in the ‘typedef’ d17188 1 a17188 1 ‘typedef’, ‘whatis’ will not unroll it. d17190 3 a17192 3 For C code, the type names may also have the form ‘class CLASS-NAME’, ‘struct STRUCT-TAG’, ‘union UNION-TAG’ or ‘enum ENUM-TAG’. d17197 1 a17197 1 ‘r’ d17200 1 a17200 1 class' members. The ‘/r’ flag disables this. d17202 1 a17202 1 ‘m’ d17205 1 a17205 1 ‘M’ d17207 2 a17208 2 the flag exists in case you change the default with ‘set print type methods’. d17210 1 a17210 1 ‘t’ d17212 2 a17213 2 controls whether the typedef definition itself is printed, not whether typedef names are substituted when printing other d17216 4 a17219 4 ‘T’ Print typedefs defined in the class. This is the default, but the flag exists in case you change the default with ‘set print type typedefs’. d17221 1 a17221 1 ‘o’ d17223 1 a17223 1 what the ‘pahole’ tool does. This option implies the ‘/tm’ d17226 1 a17226 1 ‘x’ d17230 3 a17232 3 ‘d’ Use decimal notation when printing offsets and sizes of fields in a struct. d17268 1 a17268 1 Issuing a ‘ptype /o struct tuv’ command would print: d17280 2 a17281 2 Notice the format of the first column of comments. There, you can find two parts separated by the ‘|’ character: the d17285 2 a17286 2 indicating that it may be possible to pack the struct and make it use less space by reorganizing its fields. d17320 1 a17320 1 In this case, since ‘struct tuv’ and ‘struct xyz’ occupy the d17347 2 a17348 2 ‘ptype[/FLAGS] [ARG]’ ‘ptype’ accepts the same arguments as ‘whatis’, but prints a d17352 1 a17352 1 Contrary to ‘whatis’, ‘ptype’ always unrolls any ‘typedef’s in its d17354 1 a17354 1 expression, or a data type. This means that ‘ptype’ of a variable d17356 4 a17359 4 the source code--use ‘whatis’ for that. ‘typedef’s at the pointer or reference targets are also unrolled. Only ‘typedef’s of fields, methods and inner ‘class typedef’s of ‘struct’s, ‘class’es and ‘union’s are not unrolled even with ‘ptype’. d17392 2 a17393 2 As with ‘whatis’, using ‘ptype’ without an argument refers to the type of ‘$’, the last value in the value history. d17396 4 a17399 4 specifications of complex data structure. If the debug information included in the program does not allow GDB to display a full declaration of the data type, it will say ‘’. For example, given these declarations: d17404 1 a17404 1 but no definition for ‘struct foo’ itself, GDB will say: d17427 1 a17427 1 ‘info types [-q] [REGEXP]’ d17431 4 a17434 4 it were a complete line; thus, ‘i type value’ gives information on all types in your program whose names include the string ‘value’, but ‘i type ^value$’ gives information only on types whose complete name is ‘value’. d17437 5 a17441 5 print the type description according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language Automatically: Automatically.) means to use the language of the type, other values mean to use the manually specified language (see *note Set Language Manually: Manually.). d17443 2 a17444 2 This command differs from ‘ptype’ in two ways: first, like ‘whatis’, it does not print a detailed description; second, it d17447 3 a17449 3 The output from ‘into types’ is proceeded with a header line describing what types are being listed. The optional flag ‘-q’, which stands for ‘quiet’, disables printing this header d17452 1 a17452 1 ‘info type-printers’ d17454 1 a17454 1 "type printers" available. When using ‘ptype’ or ‘whatis’, these d17458 3 a17460 1 ‘info type-printers’ displays all the available type printers. d17462 1 a17462 2 ‘enable type-printer NAME...’ ‘disable type-printer NAME...’ d17465 1 a17465 1 ‘info scope LOCSPEC’ d17482 1 a17482 1 collect during a “trace experiment”, see *note collect: Tracepoint d17485 13 a17497 8 ‘info source’ Show information about the current source file--that is, the source file for the function containing the current point of execution: • the name of the source file, and the directory containing it, • the directory it was compiled in, • its length, in lines, • which programming language it is written in, • if the debug information provides it, the program that d17500 6 a17505 4 • whether the executable includes debugging information for that file, and if so, what format the information is in (e.g., STABS, Dwarf 2, etc.), and • whether the debugging information includes information about d17508 4 a17511 5 ‘info sources [-dirname | -basename] [--] [REGEXP]’ With no options ‘info sources’ prints the names of all source files in your program for which there is debugging information. The source files are presented based on a list of object files d17522 1 a17522 1 case-insensitive filesystem (e.g., MS-Windows). ‘--’ can be used d17524 1 a17524 1 option (e.g. if REGEXP starts with ‘-’). d17527 2 a17528 2 If ‘-dirname’, only files having a dirname matching REGEXP are shown. If ‘-basename’, only files having a basename matching d17536 5 a17540 4 ‘info functions [-q] [-n]’ Print the names and data types of all defined functions. Similarly to ‘info types’, this command groups its output by source files and annotates each function definition with its source line number. d17543 2 a17544 2 print the function name and type according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language d17547 1 a17547 1 (see *note Set Language Manually: Manually.). d17549 8 a17556 8 The ‘-n’ flag excludes “non-debugging symbols” from the results. A non-debugging symbol is a symbol that comes from the executable's symbol table, not from the debug information (for example, DWARF) associated with the executable. The optional flag ‘-q’, which stands for ‘quiet’, disables printing header information and messages explaining why no functions have been printed. d17558 2 a17559 2 ‘info functions [-q] [-n] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info functions’, but only print the names and data types of d17563 3 a17565 3 the regular expression REGEXP. Thus, ‘info fun step’ finds all functions whose names include ‘step’; ‘info fun ^step’ finds those whose names start with ‘step’. If a function name contains d17567 1 a17567 1 ‘operator*()’), they may be quoted with a backslash. d17570 1 a17570 1 as printed by the ‘whatis’ command, match the regular expression d17573 5 a17577 5 the meaning of special characters or quotes. Thus, ‘info fun -t '^int ('’ finds the functions that return an integer; ‘info fun -t '(.*int.*'’ finds the functions that have an argument type containing int; ‘info fun -t '^int (' ^step’ finds the functions whose names start with ‘step’ and that return int. d17582 1 a17582 1 ‘info variables [-q] [-n]’ d17584 3 a17586 3 outside of functions (i.e. excluding local variables). The printed variables are grouped by source files and annotated with their respective source line numbers. d17589 2 a17590 2 print the variable name and type according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language d17593 1 a17593 1 (see *note Set Language Manually: Manually.). d17595 1 a17595 1 The ‘-n’ flag excludes non-debugging symbols from the results. d17597 3 a17599 3 The optional flag ‘-q’, which stands for ‘quiet’, disables printing header information and messages explaining why no variables have been printed. d17601 2 a17602 2 ‘info variables [-q] [-n] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info variables’, but only print the variables selected with d17609 1 a17609 1 as printed by the ‘whatis’ command, match the regular expression d17614 3 a17616 2 If both REGEXP and TYPE_REGEXP are provided, an argument is printed only if its name matches REGEXP and its type matches TYPE_REGEXP. d17618 1 a17618 1 ‘info modules [-q] [REGEXP]’ d17622 3 a17624 3 The optional flag ‘-q’, which stands for ‘quiet’, disables printing header information and messages explaining why no modules have been printed. d17626 2 a17627 2 ‘info module functions [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]’ ‘info module variables [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]’ d17637 3 a17639 3 The optional flag ‘-q’, which stands for ‘quiet’, disables printing header information and messages explaining why no functions or variables have been printed. d17641 1 a17641 1 ‘info main’ d17646 2 a17647 2 ‘info classes’ ‘info classes REGEXP’ d17652 2 a17653 2 ‘info selectors’ ‘info selectors REGEXP’ d17658 1 a17658 1 ‘set opaque-type-resolution on’ d17660 3 a17662 3 declared as a pointer to a ‘struct’, ‘class’, or ‘union’--for example, ‘struct MyType *’--that is used in one source file although the full declaration of ‘struct MyType’ is in another d17668 1 a17668 1 ‘set opaque-type-resolution off’ d17673 1 a17673 1 ‘show opaque-type-resolution’ d17676 8 a17683 8 ‘set print symbol-loading’ ‘set print symbol-loading full’ ‘set print symbol-loading brief’ ‘set print symbol-loading off’ The ‘set print symbol-loading’ command allows you to control the printing of messages when GDB loads symbol information. By default a message is printed for the executable and one for each shared library, and normally this is what you want. However, when d17685 5 a17689 5 messages can be annoying. When set to ‘brief’ a message is printed for each executable, and when GDB loads a collection of shared libraries at once it will only print one message regardless of the number of shared libraries. When set to ‘off’ no messages are printed. d17691 1 a17691 1 ‘show print symbol-loading’ d17695 11 a17705 11 ‘maint print symbols [-pc ADDRESS] [FILENAME]’ ‘maint print symbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]’ ‘maint print psymbols [-objfile OBJFILE] [-pc ADDRESS] [--] [FILENAME]’ ‘maint print psymbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]’ ‘maint print msymbols [-objfile OBJFILE] [--] [FILENAME]’ Write a dump of debugging symbol data into the file FILENAME or the terminal if FILENAME is unspecified. If ‘-objfile OBJFILE’ is specified, only dump symbols for that objfile. If ‘-pc ADDRESS’ is specified, only dump symbols for the file with code at that address. Note that ADDRESS may be a symbol like ‘main’. If ‘-source SOURCE’ is specified, only dump symbols for that source d17709 4 a17712 4 These commands do not modify internal GDB state, therefore ‘maint print symbols’ will only print symbols for already expanded symbol tables. You can use the command ‘info sources’ to find out which files these are. If you use ‘maint print psymbols’ instead, the d17715 1 a17715 1 but not yet read completely. Finally, ‘maint print msymbols’ just d17718 2 a17719 2 *Note Commands to Specify Files: Files, for a discussion of how GDB reads symbols (in the description of ‘symbol-file’). d17721 3 a17723 4 ‘maint info symtabs [ REGEXP ]’ ‘maint info psymtabs [ REGEXP ]’ List the ‘struct symtab’ or ‘struct partial_symtab’ structures d17745 1 a17745 1 contains the string ‘dwarf2read’, belonging to the ‘gdb’ d17767 2 a17768 3 ‘maint info line-table [ REGEXP ]’ List the ‘struct linetable’ from all ‘struct symtab’ instances d17770 1 a17770 1 ‘struct linetable’ from all ‘struct symtab’. For example: d17790 1 a17790 1 The ‘IS-STMT’ column indicates if the address is a recommended d17792 6 a17797 8 ‘PROLOGUE-END’ column indicates that a given address is an adequate place to set a breakpoint at the first instruction following a function prologue. The ‘EPILOGUE-BEGIN’ column indicates that a given address marks the point where a block's frame is destroyed, making local variables hard or impossible to find. ‘set always-read-ctf [on|off]’ ‘show always-read-ctf’ d17799 2 d17805 1 a17805 1 ‘maint set symbol-cache-size SIZE’ d17810 1 a17810 1 ‘maint show symbol-cache-size’ d17813 1 a17813 1 ‘maint print symbol-cache’ d17817 3 a17819 3 ‘maint print symbol-cache-statistics’ Print symbol cache usage statistics. This helps determine how well the cache is being utilized. d17821 2 a17822 2 ‘maint flush symbol-cache’ ‘maint flush-symbol-cache’ d17824 8 a17831 8 This command is useful when debugging the symbol cache. It is also useful when collecting performance data. The command ‘maint flush-symbol-cache’ is deprecated in favor of ‘maint flush symbol-cache’.. ‘maint set ignore-prologue-end-flag [on|off]’ Enable or disable the use of the ‘PROLOGUE-END’ flag from the line-table. When ‘off’ (the default), GDB uses the ‘PROLOGUE-END’ d17833 5 a17837 2 When ‘on’, GDB ignores the flag and relies on prologue analyzers to skip function prologues. a17838 2 ‘maint show ignore-prologue-end-flag’ Show whether GDB will ignore the ‘PROLOGUE-END’ flag. d17847 4 a17850 4 to find out for certain whether correcting the apparent error would lead to correct results in the rest of the run. You can find the answer by experiment, using the GDB features for altering execution of the program. d17877 1 a17877 1 stores the value 4 into the variable ‘x’, and then prints the value of d17883 11 a17893 11 the ‘set’ command instead of the ‘print’ command. ‘set’ is really the same as ‘print’ except that the expression's value is not printed and is not put in the value history (*note Value History: Value History.). The expression is evaluated only for its effects. If the beginning of the argument string of the ‘set’ command appears identical to a ‘set’ subcommand, use the ‘set variable’ command instead of just ‘set’. This command is identical to ‘set’ except for its lack of subcommands. For example, if your program has a variable ‘width’, you get an error if you try to set a new value with just ‘set width=13’, because GDB has the command ‘set width’: d17902 2 a17903 2 The invalid expression, of course, is ‘=47’. In order to actually set the program's variable ‘width’, use d17907 6 a17912 6 Because the ‘set’ command has many subcommands that can conflict with the names of program variables, it is a good idea to use the ‘set variable’ command instead of just ‘set’. For example, if your program has a variable ‘g’, you run into problems if you try to set a new value with just ‘set g=4’, because GDB has the command ‘set gnutarget’, abbreviated ‘set g’: d17930 2 a17931 2 The program variable ‘g’ did not change, and you silently set the ‘gnutarget’ to an invalid value. In order to set the variable ‘g’, use d17936 3 a17938 3 freely store an integer value into a pointer variable or vice versa, and you can convert any structure to any other structure that is the same length or shorter. d17940 1 a17940 1 To store values into arbitrary places in memory, use the ‘{...}’ d17942 2 a17943 2 (*note Expressions: Expressions.). For example, ‘{int}0x83040’ refers to memory location ‘0x83040’ as an integer (which implies a certain size d17957 2 a17958 2 it stopped, with the ‘continue’ command. You can instead continue at an address of your own choosing, with the following commands: d17960 2 a17961 2 ‘jump LOCSPEC’ ‘j LOCSPEC’ d17964 8 a17971 8 description of the different forms of LOCSPEC. If LOCSPEC resolves to more than one address, those outside the current compilation unit are ignored. If considering just the addresses in the current compilation unit still doesn't yield a unique address, the command aborts before jumping. Execution stops again immediately if there is a breakpoint there. It is common practice to use the ‘tbreak’ command in conjunction with ‘jump’. *Note Setting Breakpoints: Set Breaks. d17973 1 a17973 1 The ‘jump’ command does not change the current stack frame, or the d17975 8 a17982 8 register other than the program counter. If LOCSPEC resolves to an address in a different function from the one currently executing, the results may be bizarre if the two functions expect different patterns of arguments or of local variables. For this reason, the ‘jump’ command requests confirmation if the jump address is not in the function currently executing. However, even bizarre results are predictable if you are well acquainted with the machine-language code of your program. d17984 2 a17985 2 On many systems, you can get much the same effect as the ‘jump’ command by storing a new value into the register ‘$pc’. The difference d17991 3 a17993 3 makes the next ‘continue’ command or stepping command execute at address ‘0x485’, rather than at the address where your program stopped. *Note Continuing and Stepping: Continuing and Stepping. d17995 2 a17996 2 However, writing directly to ‘$pc’ will only change the value of the program-counter register, while using ‘jump’ will ensure that any d17998 3 a18000 3 ‘jump’ will update both ‘$pc’ and ‘$npc’ registers prior to resuming execution. When using the approach of writing directly to ‘$pc’ it is your job to also update the ‘$npc’ register. d18002 1 a18002 1 The most common occasion to use the ‘jump’ command is to back d18012 1 a18012 1 ‘signal SIGNAL’ d18015 2 a18016 2 number of a signal. For example, on many systems ‘signal 2’ and ‘signal SIGINT’ are both ways of sending an interrupt signal. d18018 20 a18037 20 Alternatively, if SIGNAL is zero, continue execution without giving a signal. This is useful when your program stopped on account of a signal and would ordinarily see the signal when resumed with the ‘continue’ command; ‘signal 0’ causes it to resume without a signal. _Note:_ When resuming a multi-threaded program, SIGNAL is delivered to the currently selected thread, not the thread that last reported a stop. This includes the situation where a thread was stopped due to a signal. So if you want to continue execution suppressing the signal that stopped a thread, you should select that same thread before issuing the ‘signal 0’ command. If you issue the ‘signal 0’ command with another thread as the selected one, GDB detects that and asks for confirmation. Invoking the ‘signal’ command is not the same as invoking the ‘kill’ utility from the shell. Sending a signal with ‘kill’ causes GDB to decide what to do with the signal depending on the signal handling tables (*note Signals::). The ‘signal’ command passes the signal directly to your program. d18039 1 a18039 1 ‘signal’ does not repeat when you press a second time after d18042 9 a18050 9 ‘queue-signal SIGNAL’ Queue SIGNAL to be delivered immediately to the current thread when execution of the thread resumes. The SIGNAL can be the name or the number of a signal. For example, on many systems ‘signal 2’ and ‘signal SIGINT’ are both ways of sending an interrupt signal. The handling of the signal must be set to pass the signal to the program, otherwise GDB will report an error. You can control the handling of signals from GDB with the ‘handle’ command (*note Signals::). d18054 3 a18056 3 signal will be delivered. This is useful when your program stopped on account of a signal and would ordinarily see the signal when resumed with the ‘continue’ command. d18058 2 a18059 2 This command differs from the ‘signal’ command in that the signal is just queued, execution is not resumed. And ‘queue-signal’ d18061 1 a18061 1 to ‘nopass’ (*note Signals::). d18072 3 a18074 3 ‘return’ ‘return EXPRESSION’ You can cancel execution of a function call with the ‘return’ d18078 4 a18081 4 When you use ‘return’, GDB discards the selected stack frame (and all frames within it). You can think of this as making the discarded frame return prematurely. If you wish to specify a value to be returned, give that value as the argument to ‘return’. d18089 5 a18093 5 The ‘return’ command does not resume execution; it leaves the program stopped in the state that would exist if the function had just returned. In contrast, the ‘finish’ command (*note Continuing and Stepping: Continuing and Stepping.) resumes execution until the selected stack frame returns naturally. d18098 6 a18103 6 common for OS ABI to return floating point values in FPU registers while integer values in CPU registers. Still some ABIs return even floating point values in CPU registers. Larger integer widths (such as ‘long long int’) also have specific placement rules. GDB already knows the OS ABI from its current target so it needs to find out also the type being returned to make the assignment into the right register(s). d18107 4 a18110 4 debug info is available. For example, if you type ‘return -1’, and the function in the current stack frame is declared to return a ‘long long int’, GDB transparently converts the implicit ‘int’ value of -1 into a ‘long long int’: d18124 5 a18128 4 caller code expects. For example, typing ‘return -1’ with its implicit type ‘int’ would set only a part of a ‘long long int’ result for a debug info less function (on 32-bit architectures). Therefore the user is required to specify the return type by an appropriate cast explicitly: d18145 1 a18145 1 ‘print EXPR’ d18150 2 a18151 2 ‘call EXPR’ Evaluate the expression EXPR without displaying ‘void’ returned d18154 1 a18154 1 You can use this variant of the ‘print’ command if you want to d18156 2 a18157 2 (a.k.a. “a void function”), but without cluttering the output with ‘void’ returned values that GDB will otherwise print. If the d18160 4 a18163 4 It is possible for the function you call via the ‘print’ or ‘call’ command to generate a signal (e.g., if there's a bug in the function, or if you passed it incorrect arguments). What happens in that case is controlled by the ‘set unwind-on-signal’ command. d18166 1 a18166 1 call via the ‘print’ or ‘call’ command to generate an exception that is d18172 1 a18172 1 controlled by the ‘set unwind-on-terminating-exception’ command. d18174 1 a18174 1 ‘set unwind-on-signal’ d18181 1 a18181 1 The command ‘set unwindonsignal’ is an alias for this command, and d18184 3 a18186 3 ‘show unwind-on-signal’ Show the current setting of stack unwinding in the functions called by GDB. d18188 2 a18189 2 The command ‘show unwindonsignal’ is an alias for this command, and is maintained for backward compatibility. d18191 1 a18191 1 ‘set unwind-on-terminating-exception’ d18199 10 a18208 10 ‘show unwind-on-terminating-exception’ Show the current setting of stack unwinding in the functions called by GDB. ‘set unwind-on-timeout’ Set unwinding of the stack if a function called from GDB times out. If set to ‘off’ (the default), GDB stops in the frame where the timeout occurred. If set to ‘on’, GDB unwinds the stack it created for the call and restores the context to what it was before the call. d18210 1 a18210 1 ‘show unwind-on-timeout’ d18214 1 a18214 1 ‘set may-call-functions’ d18217 1 a18217 1 with expressions in the ‘print’ command. It defaults to ‘on’. d18228 1 a18228 1 ‘show may-call-functions’ d18231 1 d18235 1 a18235 1 call by typing the interrupt character (often ‘Ctrl-c’). d18239 2 a18240 2 due to ‘set unwind-on-terminating-exception on’, ‘set unwind-on-timeout on’, or ‘set unwind-on-signal on’ (*note stack unwind settings::), then d18242 1 a18242 1 function, will be visible in the backtrace, for example frame ‘#3’ in d18257 1 a18257 1 to resume the inferior (using commands like ‘continue’, ‘step’, etc). d18268 1 a18268 1 this behaviour can be adjusted with ‘set unwind-on-timeout’ (*note set d18274 2 a18275 2 ‘unlimited’, meaning GDB will wait indefinitely for function call to complete, unless interrupted by the user using ‘Ctrl-C’. d18277 1 a18277 1 ‘set direct-call-timeout SECONDS’ d18280 2 a18281 2 special value ‘unlimited’, which indicates no timeout should be used. The default for this setting is ‘unlimited’. d18284 1 a18284 1 the command prompt, for example with a ‘call’ or ‘print’ command. d18288 1 a18288 1 setting is treated as ‘unlimited’. d18290 1 a18290 1 ‘show direct-call-timeout’ d18292 1 a18292 1 ‘call’ or ‘print’ command. d18299 1 a18299 1 ‘set indirect-call-timeout SECONDS’ d18302 1 a18302 1 integer greater than zero, or the special value ‘unlimited’, which d18304 1 a18304 1 is ‘30’ seconds. d18308 1 a18308 1 setting is treated as ‘unlimited’. d18314 1 a18314 1 ‘show indirect-call-timeout’ d18321 2 a18322 2 Sometimes, a function you wish to call is missing debug information. In such case, GDB does not know the type of the function, including the d18325 2 a18326 2 functioning erroneously and even crash, GDB refuses to call the function unless you tell it the type of the function. d18328 3 a18330 3 For prototyped (i.e. ANSI/ISO style) functions, there are two ways to do that. The simplest is to cast the call to the function's declared return type. For example: d18339 2 a18340 2 prototype that matches the types of the passed-in arguments, and calling that. I.e., the call above is equivalent to: d18356 1 a18356 1 (promote float arguments to double). *Note float promotion: ABI. For d18377 4 a18380 4 By default, GDB opens the file containing your program's executable code (or the corefile) read-only. This prevents accidental alterations to machine code; but it also prevents you from intentionally patching your program's binary. d18383 2 a18384 2 explicitly with the ‘set write’ command. For example, you might want to turn on internal debugging flags, or even to make emergency repairs. d18386 4 a18389 4 ‘set write on’ ‘set write off’ If you specify ‘set write on’, GDB opens executable and core files for both reading and writing; if you specify ‘set write off’ (the d18393 2 a18394 2 the ‘exec-file’ or ‘core-file’ command) after changing ‘set write’, for your new setting to take effect. d18396 1 a18396 1 ‘show write’ d18407 1 a18407 1 running under GDB. GCC 5.0 or higher built with ‘libcc1.so’ must be d18411 2 a18412 2 ‘compile code SOURCE-CODE’ ‘compile code -raw -- SOURCE-CODE’ d18415 8 a18422 8 is not supported with the current language specified in GDB, or the compiler does not support this feature, an error message will be printed. If SOURCE-CODE compiles and links successfully, GDB will load the object-code emitted, and execute it within the context of the currently selected inferior. It is important to note that the compiled code is executed immediately. After execution, the compiled code is removed from GDB and any new types or variables you have defined will be deleted. d18431 1 a18431 1 they may conflict. The ‘--’ delimiter can be used to separate d18437 1 a18437 1 To enter this mode, invoke the ‘compile code’ command without any d18440 1 a18440 1 required. When you have completed typing, enter ‘end’ on its own d18448 1 a18448 1 Specifying ‘-raw’, prohibits GDB from wrapping the provided d18451 3 a18453 3 ‘_gdb_expr_’. The ‘-raw’ code cannot access variables of the inferior. Using ‘-raw’ option may be needed for example when SOURCE-CODE requires ‘#include’ lines which may conflict with d18456 3 a18458 3 ‘compile file FILENAME’ ‘compile file -raw FILENAME’ Like ‘compile code’, but take the source code from FILENAME. d18462 2 a18463 2 ‘compile print [[OPTIONS] --] EXPR’ ‘compile print [[OPTIONS] --] /F EXPR’ d18467 4 a18470 4 can choose a different format by specifying ‘/F’, where F is a letter specifying the format; see *note Output Formats: Output Formats. The ‘compile print’ command accepts the same options as the ‘print’ command; see *note print options::. d18472 2 a18473 2 ‘compile print [[OPTIONS] --]’ ‘compile print [[OPTIONS] --] /F’ d18476 1 a18476 1 ‘compile print’ command without any text following the command. d18481 1 a18481 1 ‘set debug compile’ d18485 1 a18485 1 ‘show debug compile’ d18489 1 a18489 1 ‘set debug compile-cplus-types’ d18493 1 a18493 1 ‘show debug compile-cplus-types’ d18497 1 a18497 1 17.7.1 Compilation options for the ‘compile’ command d18506 1 a18506 1 target architecture and OS options (‘gdbarch’) d18508 2 a18509 2 system, usually they specify at least 32-bit (‘-m32’) or 64-bit (‘-m64’) compilation option. d18513 4 a18516 4 into ‘DW_AT_producer’ part of DWARF debugging information according to the GCC option ‘-grecord-gcc-switches’. One has to explicitly specify ‘-g’ during inferior compilation otherwise GCC produces no DWARF. This feature is only relevant for platforms where ‘-g’ d18518 1 a18518 1 by using ‘-gdwarf-4’. d18520 1 a18520 1 compilation options set by ‘set compile-args’ d18524 1 a18524 1 ‘set compile-args’ d18526 1 a18526 1 the ‘compile’ commands. These options override any conflicting d18530 1 a18530 1 ‘show compile-args’ d18532 2 a18533 2 does not show all the options actually used during compilation, use *note set debug compile:: for that. d18535 1 a18535 1 17.7.2 Caveats when using the ‘compile’ command d18538 1 a18538 1 There are a few caveats to keep in mind when using the ‘compile’ d18543 4 a18546 4 When the language in GDB is set to ‘C’, the compiler will attempt to compile the source code with a ‘C’ compiler. The source code provided to the ‘compile’ command will have much the same access to variables and types as it normally would if it were part of the d18573 3 a18575 3 For the purposes of the examples in this section, the program above has been compiled, loaded into GDB, stopped at the function ‘main’, and GDB is awaiting input from the user. d18579 2 a18580 2 ‘compile’ command is not an exception to this rule. Without debug information, you can still use the ‘compile’ command, but you will d18584 1 a18584 1 debug information enabled. The ‘compile’ command will have access d18587 6 a18592 6 ‘main’ function, the ‘compile’ command would have access to the variable ‘k’. You could invoke the ‘compile’ command and type some source code to set the value of ‘k’. You can also read it, or do anything with that variable you would normally do in ‘C’. Be aware that changes to inferior variables in the ‘compile’ command are persistent. In the following example: d18596 1 a18596 1 the variable ‘k’ is now 3. It will retain that value until d18598 1 a18598 1 ‘compile’ command changes it. d18601 4 a18604 4 injected by the ‘compile’ command. In the example, the variables ‘j’ and ‘k’ are not accessible yet, because the program is currently stopped in the ‘main’ function, where these variables are not in scope. Therefore, the following command d18610 3 a18612 3 Once the program is continued, execution will bring these variables in scope, and they will become accessible; then the code you specify via the ‘compile’ command will be able to access them. d18614 1 a18614 1 You can create variables and types with the ‘compile’ command as d18616 1 a18616 1 part of the ‘compile’ command are not visible to the rest of the d18626 2 a18627 2 a compiler error would be raised as the variable ‘ff’ no longer exists. Object code generated and injected by the ‘compile’ d18630 1 a18630 1 the code submitted to the ‘compile’ command. This example is d18635 9 a18643 8 The value of the variable ‘ff’ is assigned to ‘k’. The variable ‘k’ does not require the existence of ‘ff’ to maintain the value it has been assigned. However, pointers require particular care in assignment. If the source code compiled with the ‘compile’ command changed the address of a pointer in the example program, perhaps to a variable created in the ‘compile’ command, that pointer would point to an invalid location when the command exits. The following example would likely cause issues with your debugged program: d18647 7 a18653 7 In this example, ‘p’ would point to ‘ff’ when the ‘compile’ command is executing the source code provided to it. However, as variables in the (example) program persist with their assigned values, the variable ‘p’ would point to an invalid location when the command exists. A general rule should be followed in that you should either assign ‘NULL’ to any assigned pointers, or restore a valid location to the pointer before the command exits. d18656 5 a18660 5 typedefs defined in ‘compile’ command. Types defined in the ‘compile’ command will no longer be available in the next ‘compile’ command. Therefore, if you cast a variable to a type defined in the ‘compile’ command, care must be taken to ensure that any future need to resolve the type can be achieved. d18670 1 a18670 1 accessible to the code submitted to the ‘compile’ command. Access d18674 1 a18674 1 17.7.3 Compiler search for the ‘compile’ command d18679 1 a18679 1 running. Environment variable ‘PATH’ on GDB host is searched for GCC d18681 3 a18683 3 search can be overridden by ‘set compile-gcc’ GDB command below. ‘PATH’ is taken from shell that executed GDB, it is not the value set by GDB command ‘set environment’). *Note Environment::. d18685 2 a18686 2 Specifically ‘PATH’ is searched for binaries matching regular expression ‘ARCH(-[^-]*)?-OS-gcc’ according to the inferior target being d18688 3 a18690 3 example both ‘i386’ and ‘x86_64’ targets look for pattern ‘(x86_64|i.86)’ and both ‘s390’ and ‘s390x’ targets look for pattern ‘s390x?’. OS is currently supported only for pattern ‘linux(-gnu)?’. d18693 5 a18697 5 library ‘libcc1.so’ from the compiler. It is searched in default shared library search path (overridable with usual environment variable ‘LD_LIBRARY_PATH’), unrelated to ‘PATH’ or ‘set compile-gcc’ settings. Contrary to it ‘libcc1plugin.so’ is found according to the installation of the found compiler -- as possibly specified by the ‘set compile-gcc’ d18700 1 a18700 1 ‘set compile-gcc’ d18702 3 a18704 3 the ‘compile’ commands. If this option is not set (it is set to an empty string), the search described above will occur -- that is the default. d18706 1 a18706 1 ‘show compile-gcc’ d18708 2 a18709 2 it is the main command ‘gcc’, found usually for example under name ‘x86_64-linux-gnu-gcc’. d18745 1 a18745 1 to use. Or you are debugging a remote target via ‘gdbserver’ (*note d18749 1 a18749 1 ‘file FILENAME’ d18752 1 a18752 1 program executed when you use the ‘run’ command. If you do not d18754 1 a18754 1 directory, GDB uses the environment variable ‘PATH’ as a list of d18757 1 a18757 1 both GDB and your program, using the ‘path’ command. d18759 1 a18759 1 The FILENAME argument supports escaping and quoting, see *note d18762 5 a18766 5 You can load unlinked object ‘.o’ files into GDB using the ‘file’ command. You will not be able to "run" an object file, but you can disassemble functions and inspect variables. Also, if the underlying BFD functionality supports it, you could use ‘gdb -write’ to patch object files using this technique. Note that GDB d18771 3 a18773 3 ‘file’ ‘file’ with no argument makes GDB discard any information it has on both executable file and the symbol table. d18775 1 a18775 1 ‘exec-file [ FILENAME ]’ d18777 2 a18778 2 found in FILENAME. GDB searches the environment variable ‘PATH’ if necessary to locate your program. Omitting FILENAME means to d18781 1 a18781 1 The FILENAME argument supports escaping and quoting, see *note d18784 3 a18786 3 ‘symbol-file [ FILENAME [ -o OFFSET ]]’ Read symbol table information from file FILENAME. ‘PATH’ is searched when necessary. Use the ‘file’ command to get both symbol d18794 1 a18794 1 ‘symbol-file’ with no argument clears out GDB information on your d18797 5 a18801 5 The ‘symbol-file’ command causes GDB to forget the contents of some breakpoints and auto-display expressions. This is because they may contain pointers to the internal data recording symbols and data types, which are part of the old symbol table data being discarded inside GDB. d18803 1 a18803 1 ‘symbol-file’ does not repeat if you press again after d18806 1 a18806 1 The FILENAME argument supports escaping and quoting, see *note d18809 7 a18815 6 When GDB is configured for a particular environment, it understands debugging information in whatever format is the standard generated for that environment; you may use either a GNU compiler, or other compilers that adhere to the local conventions. Best results are usually obtained from GNU compilers; for example, using ‘GCC’ you can generate debugging information for optimized code. d18818 1 a18818 1 systems using COFF, the ‘symbol-file’ command does not normally d18824 2 a18825 2 The purpose of this two-stage reading strategy is to make GDB start up faster. For the most part, it is invisible except for d18827 3 a18829 3 source file are being read. (The ‘set verbose’ command can turn these pauses into messages if desired. *Note Optional Warnings and Messages: Messages/Warnings.) d18832 1 a18832 1 the symbol table is stored in COFF format, ‘symbol-file’ reads the d18837 2 a18838 2 ‘symbol-file [ -readnow ] FILENAME’ ‘file [ -readnow ] FILENAME’ d18840 1 a18840 1 tables by using the ‘-readnow’ option with any of the commands that d18844 2 a18845 2 ‘symbol-file [ -readnever ] FILENAME’ ‘file [ -readnever ] FILENAME’ d18847 1 a18847 1 contained in FILENAME by using the ‘-readnever’ option. *Note d18850 2 a18851 2 ‘core-file [FILENAME]’ ‘core’ d18857 1 a18857 1 ‘core-file’ with no argument specifies that no core file is to be d18862 3 a18864 3 you wish to debug a core file instead, you must kill the subprocess in which the program is running. To do this, use the ‘kill’ command (*note Killing the Child Process: Kill Process.). d18866 2 a18867 2 ‘add-symbol-file FILENAME [ -readnow | -readnever ] [ -o OFFSET ] [ TEXTADDRESS ] [ -s SECTION ADDRESS ... ]’ The ‘add-symbol-file’ command reads additional symbol table d18873 1 a18873 1 sections using an arbitrary number of ‘-s SECTION ADDRESS’ pairs. d18883 2 a18884 2 originally read with the ‘symbol-file’ command. You can use the ‘add-symbol-file’ command any number of times; the new symbol data d18887 1 a18887 1 The FILENAME argument supports escaping and quoting, see *note d18890 1 a18890 1 Changes can be reverted using the command ‘remove-symbol-file’. d18892 4 a18895 4 Although FILENAME is typically a shared library file, an executable file, or some other object file which has been fully relocated for loading into a process, you can also load symbolic information from relocatable ‘.o’ files, as long as: d18897 1 a18897 1 • the file's symbolic information refers only to linker symbols d18900 2 a18901 1 • every section the file's symbolic information refers to has d18904 3 a18906 2 • you can determine the address at which every section was loaded, and provide these to the ‘add-symbol-file’ command. d18912 6 a18917 6 complex link procedures (‘.linkonce’ section factoring and C++ constructor table assembly, for example) that make the requirements difficult to meet. In general, one cannot assume that using ‘add-symbol-file’ to read a relocatable object file's symbolic information will have the same effect as linking the relocatable object file into the program in the normal way. d18919 1 a18919 1 ‘add-symbol-file’ does not repeat if you press after using d18922 4 a18925 3 ‘remove-symbol-file FILENAME’ ‘remove-symbol-file -a ADDRESS’ Remove a symbol file added via the ‘add-symbol-file’ command. The d18939 2 a18940 2 ‘remove-symbol-file’ does not repeat if you press after using it. d18942 1 a18942 1 The FILENAME argument supports escaping and quoting, see *note d18945 1 a18945 1 ‘add-symbol-file-from-memory ADDRESS’ d18948 1 a18948 1 For example, the Linux kernel maps a ‘syscall DSO’ into each d18952 2 a18953 2 header. For this command to work, you must have used ‘symbol-file’ or ‘exec-file’ commands in advance. d18955 12 a18966 11 ‘section SECTION ADDR’ The ‘section’ command changes the base address of the named SECTION of the exec file to ADDR. This can be used if the exec file does not contain section addresses, (such as in the ‘a.out’ format), or when the addresses specified in the file itself are wrong. Each section must be changed separately. The ‘info files’ command, described below, lists all the sections and their addresses. ‘info files’ ‘info target’ ‘info files’ and ‘info target’ are synonymous; both print the d18968 4 a18971 4 including the names of the executable and core dump files currently in use by GDB, and the files from which symbols were loaded. The command ‘help target’ lists all possible targets rather than current ones. d18973 1 a18973 1 ‘maint info sections [-all-objects] [FILTER-LIST]’ d18975 2 a18976 2 sections is ‘maint info sections’. In addition to the section information displayed by ‘info files’, this command displays the d18980 1 a18980 1 When ‘-all-objects’ is passed then sections from all loaded object d18987 1 a18987 1 ‘SECTION-NAME’ d18989 2 a18990 1 ‘SECTION-FLAG’ d18993 1 a18993 1 ‘ALLOC’ d18997 2 a18998 1 ‘LOAD’ d19001 3 a19003 2 clear for ‘.bss’ sections. ‘RELOC’ d19005 2 a19006 1 ‘READONLY’ d19008 2 a19009 1 ‘CODE’ d19011 2 a19012 1 ‘DATA’ d19014 2 a19015 1 ‘ROM’ d19017 2 a19018 1 ‘CONSTRUCTOR’ d19020 2 a19021 1 ‘HAS_CONTENTS’ d19023 2 a19024 1 ‘NEVER_LOAD’ d19026 2 a19027 1 ‘COFF_SHARED_LIBRARY’ d19030 2 a19031 1 ‘IS_COMMON’ d19034 1 a19034 1 ‘maint info target-sections’ d19040 1 a19040 1 ‘set trust-readonly-sections on’ d19050 1 a19050 1 ‘set trust-readonly-sections off’ d19055 1 a19055 1 ‘show trust-readonly-sections’ d19069 5 a19073 5 GDB automatically loads symbol definitions from shared libraries when you use the ‘run’ command, or when you examine a core file. (Before you issue the ‘run’ command, GDB does not understand references to a function in a shared library, however--unless you are debugging a core file). d19082 7 a19088 7 ‘set auto-solib-add MODE’ If MODE is ‘on’, symbols from all shared object libraries will be loaded automatically when the inferior begins execution, you attach to an independently started inferior, or when the dynamic linker informs GDB that a new library has been loaded. If MODE is ‘off’, symbols must be loaded manually, using the ‘sharedlibrary’ command. The default value is ‘on’. d19093 1 a19093 1 from shared libraries. To that end, type ‘set auto-solib-add off’ d19095 1 a19095 1 symbols you do need with ‘sharedlibrary REGEXP’, where REGEXP is a d19099 1 a19099 1 ‘show auto-solib-add’ d19102 1 a19102 1 To explicitly load shared library symbols, use the ‘sharedlibrary’ d19105 2 a19106 2 ‘info share REGEX’ ‘info sharedlibrary REGEX’ d19111 2 a19112 2 ‘info dll REGEX’ This is an alias of ‘info sharedlibrary’. d19114 2 a19115 2 ‘sharedlibrary REGEX’ ‘share REGEX’ d19119 1 a19119 1 after typing ‘run’. If REGEX is omitted all shared libraries d19122 1 a19122 1 ‘nosharedlibrary’ d19130 1 a19130 1 ‘catch load’ and ‘catch unload’ (*note Set Catchpoints::). d19132 1 a19132 1 GDB also supports the ‘set stop-on-solib-events’ command for this. d19137 1 a19137 1 ‘set stop-on-solib-events’ d19143 1 a19143 1 ‘show stop-on-solib-events’ d19156 4 a19159 4 For remote debugging, you need to tell GDB where the target libraries are, so that it can load the correct copies--otherwise, it may try to load the host's libraries. GDB has two variables to specify the search directories for target libraries. d19161 1 a19161 1 ‘set sysroot PATH’ d19165 2 a19166 2 the target program's memory. When starting processes remotely, and when attaching to already-running processes (local or remote), d19168 2 a19169 2 to GDB as absolute by the operating system. If you use ‘set sysroot’ to find executables and shared libraries, they need to be d19171 1 a19171 1 ‘/bin’, ‘/lib’ and ‘/usr/lib’ hierarchy under PATH. d19173 11 a19183 11 If PATH starts with the sequence ‘target:’ and the target system is remote then GDB will retrieve the target binaries from the remote system. This is only supported when using a remote target that supports the ‘remote get’ command (*note Sending files to a remote system: File Transfer.). The part of PATH following the initial ‘target:’ (if present) is used as system root prefix on the remote file system. If PATH starts with the sequence ‘remote:’ this is converted to the sequence ‘target:’ by ‘set sysroot’(1). If you want to specify a local system root using a directory that happens to be named ‘target:’ or ‘remote:’, you need to use some equivalent variant of the name like ‘./target:’. d19186 4 a19189 4 GDB tries prefixing a few variants of the target absolute file name with PATH. But first, on Unix hosts, GDB converts all backslash directory separators into forward slashes, because the backslash is not a directory separator on Unix: d19191 1 a19191 1 c:\foo\bar.dll ⇒ c:/foo/bar.dll d19196 1 a19196 1 c:/foo/bar.dll ⇒ /path/to/sysroot/c:/foo/bar.dll d19198 1 a19198 1 If that does not find the binary, GDB tries removing the ‘:’ d19202 1 a19202 1 c:/foo/bar.dll ⇒ /path/to/sysroot/c/foo/bar.dll d19206 2 a19207 2 copies of the target system shared libraries like so (note ‘c’ vs ‘z’): d19209 7 a19215 7 /path/to/sysroot/c/sys/bin/foo.dll /path/to/sysroot/c/sys/bin/bar.dll /path/to/sysroot/z/sys/bin/bar.dll and point the system root at ‘/path/to/sysroot’, so that GDB can find the correct copies of both ‘c:\sys\bin\foo.dll’, and ‘z:\sys\bin\bar.dll’. d19220 1 a19220 1 c:/foo/bar.dll ⇒ /path/to/sysroot/foo/bar.dll d19225 2 a19226 2 The ‘set solib-absolute-prefix’ command is an alias for ‘set sysroot’. d19229 2 a19230 2 ‘--with-sysroot’ option. If the system root is inside GDB's configured binary prefix (set with ‘--prefix’ or ‘--exec-prefix’), d19234 1 a19234 1 ‘show sysroot’ d19237 1 a19237 1 ‘set solib-search-path PATH’ d19239 8 a19246 8 directories to search for shared libraries. ‘solib-search-path’ is used after ‘sysroot’ fails to locate the library, or if the path to the library is relative instead of absolute. If you want to use ‘solib-search-path’ instead of ‘sysroot’, be sure to set ‘sysroot’ to a nonexistent directory to prevent GDB from finding your host's libraries. ‘sysroot’ is preferred; setting it to a nonexistent directory may interfere with automatic loading of shared library symbols. d19248 1 a19248 1 ‘show solib-search-path’ d19251 1 a19251 1 ‘set target-file-system-kind KIND’ d19259 2 a19260 2 ‘c:\Windows\kernel32.dll’. On Unix hosts, there's no concept of drive letters, so the ‘c:\’ prefix is not normally understood as d19266 3 a19268 3 target's shared libraries on the host using ‘set sysroot’, and impractical with ‘set solib-search-path’. Setting ‘target-file-system-kind’ to ‘dos-based’ tells GDB to interpret d19271 1 a19271 1 value of KIND can be ‘"auto"’, in addition to one of the supported d19274 1 a19274 1 operating system (*note Configuring the Current ABI: ABI.). The d19277 5 a19281 5 ‘unix’ Instruct GDB to assume the target file system is of Unix kind. Only file names starting the forward slash (‘/’) character are considered absolute, and the directory separator character is also the forward slash. d19283 1 a19283 1 ‘dos-based’ d19286 2 a19287 2 letter followed by a colon (e.g., ‘c:’), are considered absolute, and both the slash (‘/’) and the backslash (‘\\’) d19290 1 a19290 1 ‘auto’ d19293 1 a19293 1 ABI.). This is the default. d19295 14 a19308 14 When processing file names provided by the user, GDB frequently needs to compare them to the file names recorded in the program's debug info. Normally, GDB compares just the “base names” of the files as strings, which is reasonably fast even for very large programs. (The base name of a file is the last portion of its name, after stripping all the leading directories.) This shortcut in comparison is based upon the assumption that files cannot have more than one base name. This is usually true, but references to files that use symlinks or similar filesystem facilities violate that assumption. If your program records files using such facilities, or if you provide file names to GDB using symlinks etc., you can set ‘basenames-may-differ’ to ‘true’ to instruct GDB to completely canonicalize each pair of file names it needs to compare. This will make file-name comparisons accurate, but at a price of a significant slowdown. d19310 1 a19310 1 ‘set basenames-may-differ’ d19313 1 a19313 1 ‘show basenames-may-differ’ d19319 1 a19319 1 remote system was provided by prefixing PATH with ‘remote:’ d19328 1 a19328 1 ‘bfd’ objects used to track open files. *Note BFD: (bfd)Top. The d19331 2 a19332 2 ‘maint info bfds’ This prints information about each ‘bfd’ object that is known to d19335 10 a19344 9 ‘maint set bfd-sharing’ ‘maint show bfd-sharing’ Control whether ‘bfd’ objects can be shared. When sharing is enabled GDB reuses already open ‘bfd’ objects rather than reopening the same file. Turning sharing off does not cause already shared ‘bfd’ objects to be unshared, but all future files that are opened will create a new ‘bfd’ object. Similarly, re-enabling sharing does not cause multiple existing ‘bfd’ objects to be collapsed into a single shared ‘bfd’ object. d19346 1 a19346 1 ‘set debug bfd-cache LEVEL’ d19349 1 a19349 1 ‘show debug bfd-cache’ d19361 2 a19362 2 information can be very large--sometimes larger than the executable code itself--some systems distribute debugging information for their d19368 1 a19368 1 • The executable contains a “debug link” that specifies the name of d19370 1 a19370 1 usually ‘EXECUTABLE.debug’, where EXECUTABLE is the name of the d19372 4 a19375 4 ‘ls.debug’ for ‘/usr/bin/ls’). In addition, the debug link specifies a 32-bit “Cyclic Redundancy Check” (CRC) checksum for the debug file, which GDB uses to validate that the executable and the debug file came from the same build. d19377 1 a19377 1 • The executable contains a “build ID”, a unique bit string that is d19381 4 a19384 4 details about this feature, see the description of the ‘--build-id’ command-line option in *note Command Line Options: (ld)Options. The debug info file's name is not specified explicitly by the build ID, but can be computed from the build ID, see below. d19389 1 a19389 1 • For the "debug link" method, GDB looks up the named file in the d19391 4 a19394 4 directory named ‘.debug’, and finally under each one of the global debug directories, in a subdirectory whose name is identical to the leading directories of the executable's absolute file name. (On MS-Windows/MS-DOS, the drive letter of the executable's leading d19396 1 a19396 1 ‘d:/usr/bin/’ is converted to ‘/d/usr/bin/’, because Windows d19399 14 a19412 13 • For the "build ID" method, GDB looks in the ‘.build-id’ subdirectory of each one of the global debug directories for a file named ‘NN/NNNNNNNN.debug’, where NN are the first 2 hex characters of the build ID bit string, and NNNNNNNN are the rest of the bit string. (Real build ID strings are 32 or more hex characters, not 10.) GDB can automatically query ‘debuginfod’ servers using build IDs in order to download separate debug files that cannot be found locally. For more information see *note Debuginfod::. So, for example, suppose you ask GDB to debug ‘/usr/bin/ls’, which has a debug link that specifies the file ‘ls.debug’, and a build ID whose value in hex is ‘abcdef1234’. If the list of the global debug directories includes ‘/usr/lib/debug’, then GDB will look for the d19415 1 a19415 4 − ‘/usr/lib/debug/.build-id/ab/cdef1234.debug’ − ‘/usr/bin/ls.debug’ − ‘/usr/bin/.debug/ls.debug’ − ‘/usr/lib/debug/usr/bin/ls.debug’. d19417 7 a19423 1 If the debug file still has not been found and ‘debuginfod’ (*note d19425 1 a19425 1 ‘debuginfod’ servers. d19428 1 a19428 1 configure option ‘--with-separate-debug-dir’ and augmented by the d19430 1 a19430 1 ‘--additional-debug-dirs’. During GDB run you can also set the global d19433 1 a19433 1 ‘set debug-file-directory DIRECTORIES’ d19438 1 a19438 1 ‘show debug-file-directory’ d19442 1 d19444 1 a19444 1 ‘.gnu_debuglink’. The section must contain: d19446 4 a19449 3 • A filename, with any leading directory components removed, followed by a zero byte, • zero to three bytes of padding, as needed to reach the next d19451 2 a19452 1 • a four-byte CRC checksum, stored in the same endianness used for d19458 1 a19458 1 contain a section named ‘.gnu_debuglink’ with the contents described d19463 7 a19469 7 named ‘.note.gnu.build-id’, but that name is not mandatory. It contains unique identification for the built files--the ID remains the same across multiple builds of the same build tree. The default algorithm SHA1 produces 160 bits (40 hexadecimal characters) of the content for the build ID string. The same section with an identical value is present in the original built binary with symbols, in its stripped variant, and in the separate debugging information file. d19475 1 a19475 1 but they need not contain any data--much like a ‘.bss’ section in an d19478 1 a19478 1 The GNU binary utilities (Binutils) package includes the ‘objcopy’ d19485 3 a19487 3 These commands remove the debugging information from the executable file ‘foo’ and place it in the file ‘foo.debug’. You can use the first, second or both methods to link the two files: d19489 2 a19490 2 • The debug link method needs the following additional command to also leave behind a debug link in ‘foo’: d19494 4 a19497 4 Ulrich Drepper's ‘elfutils’ package, starting with version 0.53, contains a version of the ‘strip’ command such that the command ‘strip foo -f foo.debug’ has the same functionality as the two ‘objcopy’ commands and the ‘ln -s’ command above, together. d19499 2 a19500 2 • Build ID gets embedded into the main executable using ‘ld --build-id’ or the GCC counterpart ‘gcc -Wl,--build-id’. Build ID d19505 1 a19505 1 The CRC used in ‘.gnu_debuglink’ is the CRC-32 defined in IEEE 802.3 d19508 2 a19509 2 x^{32} + x^{26} + x^{23} + x^{22} + x^{16} + x^{12} + x^{11} + x^{10} + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1 d19511 4 a19514 4 The function is computed byte at a time, taking the least significant bit of each byte first. The initial pattern ‘0xffffffff’ is used, to ensure leading zeros affect the CRC and the final result is inverted to ensure trailing zeros also affect the CRC. d19517 1 a19517 1 “Remote Serial Protocol” ‘qCRC’ packet (*note qCRC packet::). However d19519 2 a19520 2 significant bit first, and the result is not inverted, so trailing zeros have no effect on the CRC value. d19523 2 a19524 2 which produces the CRC used in ‘.gnu_debuglink’. Inverting the initially supplied ‘crc’ argument means that an initial call to this d19526 1 a19526 1 ‘0xffffffff’. d19604 2 a19605 2 special ‘.gnu_debugdata’ section. This feature is called “MiniDebugInfo”. This section holds an LZMA-compressed object and is d19619 2 a19620 2 This section can be easily created using ‘objcopy’ and other standard utilities: d19662 7 a19668 7 work quickly--at the cost of a delay early on. For large programs, this delay can be quite lengthy, so GDB provides a way to build an index, which speeds up startup. For convenience, GDB comes with a program, ‘gdb-add-index’, which can be used to add the index to a symbol file. It takes the symbol file as its only argument: d19675 1 a19675 1 ‘gdb-add-index’ does behind the curtains. d19679 1 a19679 1 ‘objcopy’. d19681 1 a19681 1 To create an index file, use the ‘save gdb-index’ command: d19683 1 a19683 1 ‘save gdb-index [-dwarf-5] DIRECTORY’ d19686 3 a19688 3 produces a single file ‘SYMBOL-FILE.gdb-index’. If you invoke this command with the ‘-dwarf-5’ option, it produces 2 files: ‘SYMBOL-FILE.debug_names’ and ‘SYMBOL-FILE.debug_str’. The files d19692 1 a19692 1 file, here named ‘symfile’, using ‘objcopy’: d19697 1 a19697 1 Or for ‘-dwarf-5’: d19705 5 a19709 5 GDB will normally ignore older versions of ‘.gdb_index’ sections that have been deprecated. Usually they are deprecated because they are missing a new feature or have performance issues. To tell GDB to use a deprecated index section anyway specify ‘set use-deprecated-index-sections on’. The default is ‘off’. This can d19713 1 a19713 1 _Warning:_ Setting ‘use-deprecated-index-sections’ to ‘on’ must be d19728 4 a19731 4 cache on disk and retrieve it from there when loading the same binary in the future. This feature can be turned on with ‘set index-cache enabled on’. The following commands can be used to tweak the behavior of the index cache. d19733 2 a19734 2 ‘set index-cache enabled on’ ‘set index-cache enabled off’ d19737 2 a19738 2 ‘set index-cache directory DIRECTORY’ ‘show index-cache directory’ d19742 3 a19744 3 On most systems, the index is cached in the ‘gdb’ subdirectory of the directory pointed to by the ‘XDG_CACHE_HOME’ environment variable, if it is defined, else in the ‘.cache/gdb’ subdirectory d19752 1 a19752 1 ‘show index-cache stats’ d19755 1 d19759 1 a19759 1 18.6 Extensions to ‘.debug_names’ d19763 2 a19764 2 ‘.debug_names’. GDB can both read and create this section. However, in order to work with GDB, some extensions were necessary. d19766 2 a19767 2 GDB uses the augmentation string ‘GDB2’. Earlier versions used the string ‘GDB’, but these versions of the index are no longer supported. d19773 11 a19783 11 ‘DW_IDX_GNU_internal’ This has the value ‘0x2000’. It is a flag that, when set, indicates that the associated entry has ‘static’ linkage. ‘DW_IDX_GNU_main’ This has the value ‘0x2002’. It is a flag that, when set, indicates that the associated entry is the program's ‘main’. ‘DW_IDX_GNU_language’ This has the value ‘0x2003’. It is ‘DW_LANG_’ constant, indicating the language of the associated entry. d19785 2 a19786 2 ‘DW_IDX_GNU_linkage_name’ This has the value ‘0x2004’. It is a flag that, when set, d19797 4 a19800 4 as symbol types it does not recognize, or known bugs in compiler output. By default, GDB does not notify you of such problems, since they are relatively common and primarily of interest to people debugging compilers. If you are interested in seeing information about d19804 1 a19804 1 many times the problems occur, with the ‘set complaints’ command (*note d19809 1 a19809 2 ‘inner block not inside outer block in SYMBOL’ d19817 1 a19817 1 SYMBOL may be shown as "‘(don't know)’" if the outer block is not a d19820 1 a19820 2 ‘block at ADDRESS out of order’ d19827 2 a19828 2 often determine what source file is affected by specifying ‘set verbose on’. *Note Optional Warnings and Messages: d19831 1 a19831 2 ‘bad block start address patched’ d19839 1 a19839 2 ‘bad string table offset in symbol N’ d19844 1 a19844 1 name ‘foo’, which may cause other problems if many symbols end up d19847 1 a19847 2 ‘unknown symbol type 0xNN’ d19849 1 a19849 1 yet know how to read. ‘0xNN’ is the symbol type of the d19855 3 a19857 5 feel like debugging it, you can debug ‘gdb’ with itself, breakpoint on ‘complain’, then go up to the function ‘read_dbx_symtab’ and examine ‘*bufp’ to see the symbol. ‘stub type has NULL name’ d19859 1 d19862 1 a19862 1 ‘const/volatile indicator missing (ok if using g++ v1.x), got...’ d19864 2 a19865 2 information that recent versions of the compiler should have output for it. d19867 2 a19868 1 ‘info mismatch between compiler and debugger’ a19869 1 GDB could not parse a type specification output by the compiler. d19877 2 a19878 2 GDB will sometimes read an auxiliary data file. These files are kept in a directory known as the “data directory”. d19883 1 a19883 1 ‘set data-directory DIRECTORY’ d19887 1 a19887 1 ‘show data-directory’ d19891 2 a19892 2 ‘--with-gdb-datadir’ option. If the data directory is inside GDB's configured binary prefix (set with ‘--prefix’ or ‘--exec-prefix’), then d19896 1 a19896 1 The data directory may also be specified with the ‘--data-directory’ d19905 1 a19905 1 A “target” is the execution environment occupied by your program. d19907 3 a19909 3 Often, GDB runs in the same host environment as your program; in that case, the debugging target is specified as a side effect when you use the ‘file’ or ‘core’ commands. When you need more flexibility--for d19912 1 a19912 1 connection--you can use the ‘target’ command to specify one of the d19916 3 a19918 3 It is possible to build GDB for several different “target architectures”. When GDB is built like that, you can choose one of the available architectures with the ‘set architecture’ command. d19920 1 a19920 1 ‘set architecture ARCH’ d19922 1 a19922 1 value of ARCH can be ‘"auto"’, in addition to one of the supported d19925 1 a19925 1 ‘show architecture’ d19928 4 a19931 4 ‘set processor’ ‘processor’ These are alias commands for, respectively, ‘set architecture’ and ‘show architecture’. d19951 4 a19954 4 finishes. Or if you start process recording (*note Reverse Execution::) and ‘reverse-step’ there, you are presented a virtual layer of the recording target, while the process target remains stopped at the chronologically last point of the process execution. d19956 1 a19956 1 Use the ‘core-file’ and ‘exec-file’ commands to select a new core d19958 1 a19958 1 specify as a target a process that is already running, use the ‘attach’ d19967 1 a19967 1 ‘target TYPE PARAMETERS’ d19977 2 a19978 2 The ‘target’ command does not repeat if you press again after executing the command. d19980 1 a19980 1 ‘help target’ d19982 2 a19983 2 currently selected, use either ‘info target’ or ‘info files’ (*note Commands to Specify Files: Files.). d19985 1 a19985 1 ‘help target NAME’ d19989 6 a19994 6 ‘set gnutarget ARGS’ GDB uses its own library BFD to read your files. GDB knows whether it is reading an “executable”, a “core”, or a “.o” file; however, you can specify the file format with the ‘set gnutarget’ command. Unlike most ‘target’ commands, with ‘gnutarget’ the ‘target’ refers to a program, not a machine. d19996 1 a19996 1 _Warning:_ To specify a file format with ‘set gnutarget’, you d20001 3 a20003 3 ‘show gnutarget’ Use the ‘show gnutarget’ command to display what file format ‘gnutarget’ is set to read. If you have not set ‘gnutarget’, GDB d20005 1 a20005 1 ‘show gnutarget’ displays ‘The current BFD target is "auto"’. d20010 7 a20016 7 ‘target exec PROGRAM’ An executable file. ‘target exec PROGRAM’ is the same as ‘exec-file PROGRAM’. ‘target core FILENAME’ A core dump file. ‘target core FILENAME’ is the same as ‘core-file FILENAME’. d20018 1 a20018 1 ‘target remote MEDIUM’ d20023 1 a20023 1 For example, if you have a board connected to ‘/dev/ttya’ on the d20028 1 a20028 1 ‘target remote’ supports the ‘load’ command. This is only useful d20033 1 a20033 1 ‘target sim [SIMARGS] ...’ d20041 8 a20048 8 simulators do provide these. For info about any processor-specific simulator details, see the appropriate section in *note Embedded Processors: Embedded Processors. ‘target native’ Setup for local/native process debugging. Useful to make the ‘run’ command spawn native processes (likewise ‘attach’, etc.) even when ‘set auto-connect-native-target’ is ‘off’ (*note set d20051 1 d20059 2 a20060 2 ‘set hash’ This command controls whether a hash mark ‘#’ is displayed while d20065 1 a20065 1 ‘show hash’ d20068 1 a20068 1 ‘set debug monitor’ d20072 1 a20072 1 ‘show debug monitor’ d20076 1 a20076 1 ‘load FILENAME OFFSET’ d20078 1 a20078 1 GDB, the ‘load’ command may be available. Where it exists, it is d20081 2 a20082 2 ‘load’ also records the FILENAME symbol table in GDB, like the ‘add-symbol-file’ command. d20084 3 a20086 3 If your GDB does not have a ‘load’ command, attempting to execute it gets the error message "‘You can't do that when your target is ...’" d20089 3 a20091 3 executable. For some object file formats, you can specify the load address when you link the program; for other formats, like a.out, the object file format specifies a fixed address. d20100 1 a20100 1 ‘load’ does not repeat if you press again after using it. d20102 2 a20103 1 ‘flash-erase’ a20104 1 Erases all known flash memory regions on the target. d20113 5 a20117 5 offer the ability to run either big-endian or little-endian byte orders. Usually the executable or symbol will include a bit to designate the endian-ness, and you will not need to worry about which to use. However, you may still find it useful to adjust GDB's idea of processor endian-ness manually. d20119 1 a20119 1 ‘set endian big’ d20122 1 a20122 1 ‘set endian little’ d20125 1 a20125 1 ‘set endian auto’ d20128 1 a20128 1 ‘show endian’ d20131 8 a20138 7 If the ‘set endian auto’ mode is in effect and no executable has been selected, then the endianness used is the last one chosen either by one of the ‘set endian big’ and ‘set endian little’ commands or by inferring from the last executable used. If no endianness has been previously chosen, then the default for this mode is inferred from the target GDB has been built for, and is ‘little’ if the name of the target CPU has an ‘el’ suffix and ‘big’ otherwise. d20164 1 a20164 1 use ‘help target’ to list them. d20188 3 a20190 3 GDB supports two types of remote connections, ‘target remote’ mode and ‘target extended-remote’ mode. Note that many remote targets support only ‘target remote’ mode. There are several major differences between d20196 1 a20196 1 ‘gdbserver’, ‘gdbserver’ will exit. d20198 5 a20202 5 *With target extended-remote mode:* When the debugged program exits or you detach from it, GDB remains connected to the target, even though no program is running. You can rerun the program, attach to a running program, or use ‘monitor’ commands specific to the target. d20204 3 a20206 3 When using ‘gdbserver’ in this case, it does not exit unless it was invoked using the ‘--once’ option. If the ‘--once’ option was not used, you can ask ‘gdbserver’ to exit using the ‘monitor exit’ d20210 2 a20211 2 For both connection types you use the ‘file’ command to specify the program on the host system. If you are using ‘gdbserver’ there are d20216 1 a20216 1 debug on the ‘gdbserver’ command line or use the ‘--attach’ option d20220 2 a20221 2 debug on the ‘gdbserver’ command line, or you can load the program or attach to it using GDB commands after connecting to ‘gdbserver’. d20223 9 a20231 8 You can start ‘gdbserver’ without supplying an initial command to run or process ID to attach. To do this, use the ‘--multi’ command line option. Then you can connect using ‘target extended-remote’ and start the program you want to debug (see below for details on using the ‘run’ command in this scenario). Note that the conditions under which ‘gdbserver’ terminates depend on how GDB connects to it (‘target remote’ or ‘target extended-remote’). The ‘--multi’ option to ‘gdbserver’ has no influence on that. d20233 2 a20234 2 The ‘run’ command *With target remote mode:* The ‘run’ command is not supported. d20237 2 a20238 2 already running, so you can use commands like ‘step’ and ‘continue’. d20240 5 a20244 5 *With target extended-remote mode:* The ‘run’ command is supported. The ‘run’ command uses the value set by ‘set remote exec-file’ (*note set remote exec-file::) to select the program to run. Command line arguments are supported, except for wildcard expansion and I/O redirection (*note Arguments::). d20247 3 a20249 3 ‘run’ command is not required to start execution, and you can resume using commands like ‘step’ and ‘continue’ as with ‘target remote’ mode. d20252 3 a20254 3 *With target remote mode:* The GDB command ‘attach’ is not supported. To attach to a running program using ‘gdbserver’, you must use the ‘--attach’ option (*note Running gdbserver::). d20257 3 a20259 3 you may use the ‘attach’ command after the connection has been established. If you are using ‘gdbserver’, you may also invoke ‘gdbserver’ using the ‘--attach’ option (*note Running d20264 1 a20264 1 case, GDB uses the value of ‘exec-file-mismatch’ to handle a d20269 1 d20276 2 a20277 2 associated symbol files. Note that this section applies equally to both ‘target remote’ mode and ‘target extended-remote’ mode. d20282 2 a20283 2 the remote program is unstripped, the only command you need is ‘target remote’ (or ‘target extended-remote’). d20287 5 a20291 5 unstripped copy of your program as the first argument, or use the ‘file’ command. Use ‘set sysroot’ to specify the location (on the host) of target libraries (unless your GDB was compiled with the correct sysroot using ‘--with-sysroot’). Alternatively, you may use ‘set solib-search-path’ to specify how GDB locates target libraries. d20294 6 a20299 5 executable and libraries on the target, with one exception: the files on the host system should not be stripped, even if the files on the target system are. Mismatched or missing files will lead to confusing results during debugging. On GNU/Linux targets, mismatched or missing files may also prevent ‘gdbserver’ from debugging multi-threaded programs. d20307 2 a20308 2 carrying the debugging packets varies. The ‘target remote’ and ‘target extended-remote’ commands establish a connection to the target. Both d20311 2 a20312 2 ‘target remote SERIAL-DEVICE’ ‘target extended-remote SERIAL-DEVICE’ d20314 1 a20314 1 use a serial line connected to the device named ‘/dev/ttyb’: d20319 2 a20320 2 ‘--baud’ option, or use the ‘set serial baud’ command (*note set serial baud: Remote Configuration.) before the ‘target’ command. d20322 2 a20323 2 ‘target remote LOCAL-SOCKET’ ‘target extended-remote LOCAL-SOCKET’ d20326 1 a20326 1 ‘/tmp/gdb-socket0’: d20336 14 a20349 14 ‘target remote HOST:PORT’ ‘target remote [HOST]:PORT’ ‘target remote tcp:HOST:PORT’ ‘target remote tcp:[HOST]:PORT’ ‘target remote tcp4:HOST:PORT’ ‘target remote tcp6:HOST:PORT’ ‘target remote tcp6:[HOST]:PORT’ ‘target extended-remote HOST:PORT’ ‘target extended-remote [HOST]:PORT’ ‘target extended-remote tcp:HOST:PORT’ ‘target extended-remote tcp:[HOST]:PORT’ ‘target extended-remote tcp4:HOST:PORT’ ‘target extended-remote tcp6:HOST:PORT’ ‘target extended-remote tcp6:[HOST]:PORT’ d20359 1 a20359 1 ‘manyfarms’: d20364 1 a20364 1 ‘2001:0db8:85a3:0000:0000:8a2e:0370:7334’, you can either use the d20377 2 a20378 2 that for GDB there is no ambiguity: the number after the last colon is considered to be the port number. d20382 2 a20383 2 the same host), you can omit the hostname. For example, to connect to port 1234 on your local machine: a20385 1 d20388 10 a20397 10 ‘target remote udp:HOST:PORT’ ‘target remote udp:[HOST]:PORT’ ‘target remote udp4:HOST:PORT’ ‘target remote udp6:[HOST]:PORT’ ‘target extended-remote udp:HOST:PORT’ ‘target extended-remote udp:HOST:PORT’ ‘target extended-remote udp:[HOST]:PORT’ ‘target extended-remote udp4:HOST:PORT’ ‘target extended-remote udp6:HOST:PORT’ ‘target extended-remote udp6:[HOST]:PORT’ d20399 1 a20399 1 to UDP port 2828 on a terminal server named ‘manyfarms’: d20404 13 a20416 13 in mind that the 'U' stands for "Unreliable". UDP can silently drop packets on busy or unreliable networks, which will cause havoc with your debugging session. ‘target remote | COMMAND’ ‘target extended-remote | COMMAND’ Run COMMAND in the background and communicate with it using a pipe. The COMMAND is a shell command, to be parsed and expanded by the system's command shell, ‘/bin/sh’; it should expect remote protocol packets on its standard input, and send replies on its standard output. You could use this to run a stand-alone simulator that speaks the remote debugging protocol, to make net connections using programs like ‘ssh’, or for other similar tricks. d20419 1 a20419 1 will try to send it a ‘SIGTERM’ signal. (If the program has d20422 1 d20424 1 a20424 1 interrupt character (often ‘Ctrl-c’), GDB attempts to stop the program. d20432 1 a20432 1 In ‘target remote’ mode, if you type ‘y’, GDB abandons the remote d20434 1 a20434 1 use ‘target remote’ again to connect once more.) If you type ‘n’, GDB d20437 2 a20438 2 In ‘target extended-remote’ mode, typing ‘n’ will leave GDB connected to the target. d20440 1 a20440 1 ‘detach’ d20442 1 a20442 1 the ‘detach’ command to release it from GDB control. Detaching d20444 3 a20446 3 will depend on your particular remote stub. After the ‘detach’ command in ‘target remote’ mode, GDB is free to connect to another target. In ‘target extended-remote’ mode, GDB is still connected d20449 2 a20450 2 ‘disconnect’ The ‘disconnect’ command closes the connection to the target, and d20453 1 a20453 1 the ‘disconnect’ command, GDB is again free to connect to another d20456 1 a20456 1 ‘monitor CMD’ d20458 4 a20461 4 remote monitor. Since GDB doesn't care about the commands it sends like this, this command is the way to extend GDB--you can add new commands that only the external monitor will understand and implement. d20470 3 a20472 3 connection used to communicate with GDB. This is convenient for targets accessible through other means, e.g. GNU/Linux systems running ‘gdbserver’ over a network interface. For other targets, e.g. embedded d20478 1 a20478 1 ‘remote put HOSTFILE TARGETFILE’ d20482 3 a20484 3 ‘remote get TARGETFILE HOSTFILE’ Copy file TARGETFILE from the target system to HOSTFILE on the host system. d20486 1 a20486 1 ‘remote delete TARGETFILE’ d20489 1 d20493 1 a20493 1 20.3 Using the ‘gdbserver’ Program d20496 4 a20499 3 ‘gdbserver’ is a control program for Unix-like systems, which allows you to connect your program with a remote GDB via ‘target remote’ or ‘target extended-remote’--but without linking in the usual debugging stub. d20501 1 a20501 1 ‘gdbserver’ is not a complete replacement for the debugging stubs, d20503 10 a20512 10 that GDB itself does. In fact, a system that can run ‘gdbserver’ to connect to a remote GDB could also run GDB locally! ‘gdbserver’ is sometimes useful nevertheless, because it is a much smaller program than GDB itself. It is also easier to port than all of GDB, so you may be able to get started more quickly on a new system by using ‘gdbserver’. Finally, if you develop code for real-time systems, you may find that the tradeoffs involved in real-time operation make it more convenient to do as much development work as possible on another system, for example by cross-compiling. You can use ‘gdbserver’ to make a similar choice for debugging. d20514 1 a20514 1 GDB and ‘gdbserver’ communicate via either a serial line or a TCP d20517 4 a20520 4 _Warning:_ ‘gdbserver’ does not have any built-in security. Do not run ‘gdbserver’ connected to any public network; a GDB connection to ‘gdbserver’ provides access to the target system with the same privileges as the user running ‘gdbserver’. d20522 1 a20522 1 20.3.1 Running ‘gdbserver’ d20525 2 a20526 2 Run ‘gdbserver’ on the target system. You need a copy of the program you want to debug, including any libraries it requires. ‘gdbserver’ d20538 3 a20540 3 hostname and portnumber, or ‘-’ or ‘stdio’ to use stdin/stdout of ‘gdbserver’. For example, to debug Emacs with the argument ‘foo.txt’ and communicate with GDB over the serial port ‘/dev/com1’: d20544 1 a20544 1 ‘gdbserver’ waits passively for the host GDB to communicate with it. d20551 4 a20554 4 specifying that you are communicating with the host GDB via TCP. The ‘host:2345’ argument means that ‘gdbserver’ is to expect a TCP connection from machine ‘host’ to local TCP port 2345. (Currently, the ‘host’ part is ignored.) You can choose any number you want for the d20556 3 a20558 3 in use on the target system (for example, ‘23’ is reserved for ‘telnet’).(1) You must use the same port number with the host GDB ‘target remote’ command. d20560 1 a20560 1 The ‘stdio’ connection is useful when starting ‘gdbserver’ with ssh: d20564 1 a20564 1 The ‘-T’ option to ssh is provided because we don't need a remote d20569 3 a20571 3 Programs started with stdio-connected gdbserver have ‘/dev/null’ for ‘stdin’, and ‘stdout’,‘stderr’ are sent back to gdb for display through a pipe connected to gdbserver. Both ‘stdout’ and ‘stderr’ use the same d20577 2 a20578 2 On some targets, ‘gdbserver’ can also attach to running programs. This is accomplished via the ‘--attach’ argument. The syntax is: d20583 1 a20583 1 necessary to point ‘gdbserver’ at a binary for the running process. d20585 1 a20585 1 In ‘target extended-remote’ mode, you can also attach using the GDB d20589 1 a20589 1 has the ‘pidof’ utility: d20594 1 a20594 1 multiple threads, most versions of ‘pidof’ support the ‘-s’ option to d20597 1 a20597 1 20.3.1.2 TCP port allocation lifecycle of ‘gdbserver’ d20600 1 a20600 1 This section applies only when ‘gdbserver’ is run to listen on a TCP d20603 3 a20605 3 ‘gdbserver’ normally terminates after all of its debugged processes have terminated in ‘target remote’ mode. On the other hand, for ‘target extended-remote’, ‘gdbserver’ stays running even with no processes left. d20607 1 a20607 1 normally also terminates ‘gdbserver’ in the ‘target remote’ mode. d20609 2 a20610 2 ‘gdbserver’ to kill its debugged processes, ‘gdbserver’ stays running even in the ‘target remote’ mode. d20612 2 a20613 2 When ‘gdbserver’ stays running, GDB can connect to it again later. Such reconnecting is useful for features like *note disconnected d20617 3 a20619 3 By default, ‘gdbserver’ keeps the listening TCP port open, so that subsequent connections are possible. However, if you start ‘gdbserver’ with the ‘--once’ option, it will stop listening for any further d20621 2 a20622 2 means no further connections to ‘gdbserver’ will be possible after the first one. It also means ‘gdbserver’ will terminate after the first d20624 4 a20627 4 connections and even in the ‘target extended-remote’ mode. The ‘--once’ option allows reusing the same port number for connecting to multiple instances of ‘gdbserver’ running on the same host, since each instance closes its port after the first connection. d20629 1 a20629 1 20.3.1.3 Other Command-Line Arguments for ‘gdbserver’ d20632 5 a20636 4 You can use the ‘--multi’ option to start ‘gdbserver’ without specifying a program to debug or a process to attach to. Then you can attach in ‘target extended-remote’ mode and run or attach to a program. For more information, *note --multi Option in Types of Remote Connnections::. d20638 1 a20638 1 The ‘--debug[=option1,option2,...]’ option tells ‘gdbserver’ to d20640 1 a20640 1 options (OPTION1, OPTION2, etc) control for which areas of ‘gdbserver’ d20643 1 a20643 1 ‘all’ d20645 2 a20646 1 ‘threads’ d20649 3 a20651 2 this could change in future releases of ‘gdbserver’. ‘event-loop’ d20653 2 a20654 1 ‘remote’ d20658 6 a20663 6 If no options are passed to ‘--debug’ then this is treated as equivalent to ‘--debug=threads’. This could change in future releases of ‘gdbserver’. The options passed to ‘--debug’ are processed left to right, and individual options can be prefixed with the ‘-’ (minus) character to disable diagnostic output from this area, so it is possible to use: d20669 1 a20669 1 The ‘--debug-file=FILENAME’ option tells ‘gdbserver’ to write any d20671 1 a20671 1 ‘gdbserver’ development and for bug reports to the developers. d20673 1 a20673 1 The ‘--debug-format=option1[,option2,...]’ option tells ‘gdbserver’ d20676 1 a20676 1 ‘none’ d20678 2 a20679 1 ‘all’ d20681 2 a20682 1 ‘timestamps’ d20685 3 a20687 2 Options are processed in order. Thus, for example, if ‘none’ appears last then no additional information is added to debugging output. d20689 1 a20689 1 The ‘--wrapper’ option specifies a wrapper to launch programs for d20691 1 a20691 1 then any command-line arguments to pass to the wrapper, then ‘--’ d20694 1 a20694 1 ‘gdbserver’ runs the specified wrapper program with a combined d20699 1 a20699 1 You can use any program that eventually calls ‘execve’ with its d20701 1 a20701 1 ‘env’ and ‘nohup’. Any Unix shell script ending with ‘exec "$@@"’ will d20704 2 a20705 2 For example, you can use ‘env’ to pass an environment variable to the debugged program, without setting the variable in ‘gdbserver’'s d20710 1 a20710 1 The ‘--selftest’ option runs the self tests in ‘gdbserver’: d20717 1 a20717 1 20.3.2 Connecting to ‘gdbserver’ d20721 1 d20723 1 a20723 3 • Run GDB on the host system. • Make sure you have the necessary symbol files (*note Host and d20725 1 a20725 1 ‘file’ command before you connect. Use ‘set sysroot’ to locate d20727 1 a20727 1 sysroot using ‘--with-sysroot’). d20729 3 a20731 3 • Connect to your target (*note Connecting to a Remote Target: Connecting.). For TCP connections, you must start up ‘gdbserver’ prior to using the ‘target’ command. Otherwise you may get an d20733 2 a20734 2 looks something like ‘Connection refused’. Don't use the ‘load’ command in GDB when using ‘target remote’ mode, since the program d20737 2 a20738 1 20.3.3 Monitor Commands for ‘gdbserver’ d20741 3 a20743 3 During a GDB session using ‘gdbserver’, you can use the ‘monitor’ command to send special requests to ‘gdbserver’. Here are the available commands. d20745 1 a20745 1 ‘monitor help’ d20748 1 a20748 1 ‘monitor set debug off’ d20751 1 a20751 1 ‘monitor set debug on’ d20753 1 a20753 1 is equivalent to ‘monitor set debug threads on’, but this might d20756 2 a20757 2 ‘monitor set debug threads off’ ‘monitor set debug threads on’ d20763 2 a20764 2 ‘monitor set debug remote off’ ‘monitor set debug remote on’ d20768 2 a20769 2 ‘monitor set debug event-loop off’ ‘monitor set debug event-loop on’ d20773 2 a20774 2 ‘monitor set debug-file filename’ ‘monitor set debug-file’ d20777 1 a20777 1 ‘monitor set debug-format option1[,option2,...]’ d20781 1 a20781 1 ‘none’ d20783 2 a20784 1 ‘all’ d20786 2 a20787 1 ‘timestamps’ d20790 1 a20790 1 Options are processed in order. Thus, for example, if ‘none’ d20794 1 a20794 1 ‘monitor set libthread-db-search-path [PATH]’ d20796 1 a20796 1 directories to search for ‘libthread_db’ (*note set d20798 1 a20798 1 ‘libthread-db-search-path’ will be reset to its default value. d20800 2 a20801 2 The special entry ‘$pdir’ for ‘libthread-db-search-path’ is not supported in ‘gdbserver’. d20803 1 a20803 1 ‘monitor exit’ d20805 3 a20807 3 followed by ‘disconnect’ to close the debugging session. ‘gdbserver’ will detach from any attached processes and kill any processes it created. Use ‘monitor exit’ to terminate ‘gdbserver’ d20810 2 a20811 1 20.3.4 Tracepoints support in ‘gdbserver’ d20814 1 a20814 1 On some targets, ‘gdbserver’ supports tracepoints, fast tracepoints and d20818 3 a20820 3 “in-process agent” (IPA), must be loaded in the inferior process. This library is built and distributed as an integral part of ‘gdbserver’. In addition, support for static tracepoints requires building the d20822 1 a20822 1 the UST (LTTng Userspace Tracer, ) tracing engine d20825 3 a20827 3 ‘gdbserver’ is built, or if ‘gdbserver’ was explicitly configured using ‘--with-ust’ to point at such headers. You can explicitly disable the support using ‘--with-ust=no’. d20831 1 a20831 2 ‘Specifying it as dependency at link time’ d20834 1 a20834 3 ‘-linproctrace’ to the link command. ‘Using the system's preloading mechanisms’ d20836 1 d20840 3 a20842 5 cases, you do that by specifying ‘LD_PRELOAD=libinproctrace.so’ in the environment. See also the description of ‘gdbserver’'s ‘--wrapper’ command line option. ‘Using GDB to force loading the agent at run time’ d20844 1 d20848 2 a20849 2 On most Unix systems, the function is ‘dlopen’. You'll use the ‘call’ command for that. For example: d20853 2 a20854 2 Note that on most Unix systems, for the ‘dlopen’ function to be available, the program needs to be linked with ‘-ldl’. d20857 1 a20857 1 systems, when you connect to ‘gdbserver’ using ‘target remote’, you'll d20860 5 a20864 5 yet, including the in-process agent. In that case, before being able to use any of the fast or static tracepoints features, you need to let the loader run and load the shared libraries. The simplest way to do that is to run the program to the main procedure. E.g., if debugging a C or C++ program, start ‘gdbserver’ like so: d20868 1 a20868 1 Start GDB and connect to ‘gdbserver’ like so, and run to main: d20877 4 a20880 4 process; you can confirm it with the ‘info sharedlibrary’ command, which will list ‘libinproctrace.so’ as loaded in the process. You are now ready to install fast tracepoints, list static tracepoint markers, probe static tracepoints markers, and start tracing. d20885 1 a20885 1 ‘gdbserver’ prints an error message and exits. d20895 1 a20895 1 extensions of the remote protocol, see *note system-call-allowed: d20898 1 a20898 1 ‘set remoteaddresssize BITS’ d20901 2 a20902 2 number, when it passes addresses to the remote target. The default value is the number of bits in the target's address. d20904 1 a20904 1 ‘show remoteaddresssize’ d20907 1 a20907 1 ‘set serial baud N’ d20912 1 a20912 1 ‘show serial baud’ d20915 3 a20917 3 ‘set serial parity PARITY’ Set the parity for the remote serial I/O. Supported values of PARITY are: ‘even’, ‘none’, and ‘odd’. The default is ‘none’. d20919 1 a20919 1 ‘show serial parity’ d20922 5 a20926 5 ‘set remotebreak’ If set to on, GDB sends a ‘BREAK’ signal to the remote when you type ‘Ctrl-c’ to interrupt the program running on the remote. If set to off, GDB sends the ‘Ctrl-C’ character instead. The default is off, since most remote systems expect to see ‘Ctrl-C’ as the d20929 2 a20930 2 ‘show remotebreak’ Show whether GDB sends ‘BREAK’ or ‘Ctrl-C’ to interrupt the remote d20933 4 a20936 4 ‘set remoteflow on’ ‘set remoteflow off’ Enable or disable hardware flow control (‘RTS’/‘CTS’) on the serial port used to communicate to the remote target. d20938 1 a20938 1 ‘show remoteflow’ d20941 1 a20941 1 ‘set remotelogbase BASE’ d20943 2 a20944 2 communications to BASE. Supported values of BASE are: ‘ascii’, ‘octal’, and ‘hex’. The default is ‘ascii’. d20946 1 a20946 1 ‘show remotelogbase’ d20950 3 a20952 3 ‘set remotelogfile FILE’ Record remote serial communications on the named FILE. The default is not to record at all. d20954 2 a20955 2 ‘show remotelogfile’ Show the current setting of the file name on which to record the d20958 1 a20958 1 ‘set remotetimeout NUM’ d20962 1 a20962 1 ‘show remotetimeout’ d20966 2 a20967 2 ‘set remote hardware-watchpoint-limit LIMIT’ ‘set remote hardware-breakpoint-limit LIMIT’ d20970 1 a20970 1 watchpoints or breakpoints, and ‘unlimited’ for unlimited d20973 2 a20974 2 ‘show remote hardware-watchpoint-limit’ ‘show remote hardware-breakpoint-limit’ d20978 1 a20978 1 ‘set remote hardware-watchpoint-length-limit LIMIT’ d20981 1 a20981 1 watchpoints and ‘unlimited’ allows watchpoints of any length. d20983 15 a20997 15 ‘show remote hardware-watchpoint-length-limit’ Show the current limit (in bytes) of the maximum length of a remote hardware watchpoint. ‘set remote exec-file FILENAME’ ‘show remote exec-file’ Select the file used for ‘run’ with ‘target extended-remote’. This should be set to a filename valid on the target system. If it is not set, the target will use a default filename (e.g. the last program run). ‘set remote interrupt-sequence’ Allow the user to select one of ‘Ctrl-C’, a ‘BREAK’ or ‘BREAK-g’ as the sequence to the remote target in order to interrupt the execution. ‘Ctrl-C’ is a default. Some system prefers ‘BREAK’ d20999 2 a21000 2 kernel prefers ‘BREAK-g’, a.k.a Magic SysRq g. It is ‘BREAK’ signal followed by character ‘g’. d21002 4 a21005 4 ‘show remote interrupt-sequence’ Show which of ‘Ctrl-C’, ‘BREAK’ or ‘BREAK-g’ is sent by GDB to interrupt the remote program. ‘BREAK-g’ is BREAK signal followed by ‘g’ and also known as Magic SysRq g. d21007 1 a21007 1 ‘set remote interrupt-on-connect’ d21010 1 a21010 1 kernel. Linux kernel expects ‘BREAK’ followed by ‘g’ which is d21013 1 a21013 1 ‘show remote interrupt-on-connect’ d21017 1 a21017 1 ‘set tcp auto-retry on’ d21022 3 a21024 3 auto-retry is enabled, if the initial attempt to connect fails, GDB reattempts to establish the connection using the timeout specified by ‘set tcp connect-timeout’. d21026 1 a21026 1 ‘set tcp auto-retry off’ d21029 1 a21029 1 ‘show tcp auto-retry’ d21032 2 a21033 2 ‘set tcp connect-timeout SECONDS’ ‘set tcp connect-timeout unlimited’ d21036 6 a21041 6 failed connections (enabled by ‘set tcp auto-retry on’) and waiting for connections that are merely slow to complete, and represents an approximate cumulative value. If SECONDS is ‘unlimited’, there is no timeout and GDB will keep attempting to establish a connection forever, unless interrupted with ‘Ctrl-c’. The default is 15 seconds. d21043 1 a21043 1 ‘show tcp connect-timeout’ d21048 5 a21052 5 these commands to enable or disable individual packets. Each packet can be set to ‘on’ (the remote target supports this packet), ‘off’ (the remote target does not support this packet), or ‘auto’ (detect remote target support for this packet). They all default to ‘auto’. For more information about each packet, see *note Remote Protocol::. d21059 1 a21059 1 ‘set remote NAME-packet’. If you configure a packet, the configuration d21064 1 a21064 1 ‘show remote NAME-packet’. It displays the current remote target's d21070 5 a21074 16 ‘fetch-register’ ‘p’ ‘info registers’ ‘set-register’ ‘P’ ‘set’ ‘binary-download’ ‘X’ ‘load’, ‘set’ ‘read-aux-vector’ ‘qXfer:auxv:read’ ‘info auxv’ ‘symbol-lookup’ ‘qSymbol’ Detecting multiple threads ‘attach’ ‘vAttach’ ‘attach’ ‘verbose-resume’ ‘vCont’ Stepping or resuming d21076 21 a21096 34 ‘run’ ‘vRun’ ‘run’ ‘software-breakpoint’‘Z0’ ‘break’ ‘hardware-breakpoint’‘Z1’ ‘hbreak’ ‘write-watchpoint’ ‘Z2’ ‘watch’ ‘read-watchpoint’ ‘Z3’ ‘rwatch’ ‘access-watchpoint’ ‘Z4’ ‘awatch’ ‘pid-to-exec-file’ ‘qXfer:exec-file:read’ ‘attach’, ‘run’ ‘target-features’ ‘qXfer:features:read’ ‘set architecture’ ‘library-info’ ‘qXfer:libraries:read’ ‘info sharedlibrary’ ‘memory-map’ ‘qXfer:memory-map:read’ ‘info mem’ ‘read-sdata-object’ ‘qXfer:sdata:read’ ‘print $_sdata’ ‘read-siginfo-object’‘qXfer:siginfo:read’ ‘print $_siginfo’ ‘write-siginfo-object’‘qXfer:siginfo:write’ ‘set $_siginfo’ ‘threads’ ‘qXfer:threads:read’ ‘info threads’ ‘get-thread-local- ‘qGetTLSAddr’ Displaying storage-address’ ‘__thread’ d21098 5 a21102 10 ‘get-thread-information-block-address’‘qGetTIBAddr’Display MS-Windows Thread Information Block. ‘search-memory’ ‘qSearch:memory’ ‘find’ ‘supported-packets’ ‘qSupported’ Remote d21105 16 a21120 28 ‘catch-syscalls’ ‘QCatchSyscalls’ ‘catch syscall’ ‘pass-signals’ ‘QPassSignals’ ‘handle SIGNAL’ ‘program-signals’ ‘QProgramSignals’ ‘handle SIGNAL’ ‘hostio-close-packet’‘vFile:close’ ‘remote get’, ‘remote put’ ‘hostio-open-packet’ ‘vFile:open’ ‘remote get’, ‘remote put’ ‘hostio-pread-packet’‘vFile:pread’ ‘remote get’, ‘remote put’ ‘hostio-pwrite-packet’‘vFile:pwrite’ ‘remote get’, ‘remote put’ ‘hostio-unlink-packet’‘vFile:unlink’ ‘remote delete’ ‘hostio-readlink-packet’‘vFile:readlink’ Host I/O ‘hostio-fstat-packet’‘vFile:fstat’ Host I/O ‘hostio-setfs-packet’‘vFile:setfs’ Host I/O ‘noack-packet’ ‘QStartNoAckMode’ Packet d21122 2 a21123 4 ‘osdata’ ‘qXfer:osdata:read’ ‘info os’ ‘query-attached’ ‘qAttached’ Querying remote d21126 5 a21130 9 ‘trace-buffer-size’ ‘QTBuffer:size’ ‘set trace-buffer-size’ ‘trace-status’ ‘qTStatus’ ‘tstatus’ ‘traceframe-info’ ‘qXfer:traceframe-info:read’Traceframe info ‘install-in-trace’ ‘InstallInTrace’ Install d21133 8 a21140 14 ‘disable-randomization’‘QDisableRandomization’‘set disable-randomization’ ‘startup-with-shell’ ‘QStartupWithShell’ ‘set startup-with-shell’ ‘environment-hex-encoded’‘QEnvironmentHexEncoded’‘set environment’ ‘environment-unset’ ‘QEnvironmentUnset’ ‘unset environment’ ‘environment-reset’ ‘QEnvironmentReset’ ‘Reset the d21145 3 a21147 5 variables)’ ‘set-working-dir’ ‘QSetWorkingDir’ ‘set cwd’ ‘conditional-breakpoints-packet’‘Z0 and Z1’ ‘Support for d21151 3 a21153 4 evaluation’ ‘multiprocess-extensions’‘multiprocess Debug multiple extensions’ processes and d21156 6 a21161 12 ‘swbreak-feature’ ‘swbreak stop reason’ ‘break’ ‘hwbreak-feature’ ‘hwbreak stop reason’ ‘hbreak’ ‘fork-event-feature’ ‘fork stop reason’ ‘fork’ ‘vfork-event-feature’‘vfork stop reason’ ‘vfork’ ‘exec-event-feature’ ‘exec stop reason’ ‘exec’ ‘thread-events’ ‘QThreadEvents’ Tracking thread d21163 4 a21166 8 ‘thread-options’ ‘QThreadOptions’ Set thread event reporting options. ‘no-resumed-stop-reply’‘no resumed thread Tracking thread left stop reply’ lifetime. d21170 11 a21180 11 ‘set remote memory-read-packet-size’ and ‘set remote memory-write-packet-size’. If set to ‘0’ (zero) the default packet size will be used. The actual limit is further reduced depending on the target. Specify ‘fixed’ to disable the target-dependent restriction and ‘limit’ to enable it. Similar to the enabling and disabling of remote packets, the command applies to the currently selected target (if available). If no remote target is selected, it applies to all future remote connections. The configuration of the selected target can be displayed using the commands ‘show remote memory-read-packet-size’ and ‘show remote memory-write-packet-size’. If no remote target is d21191 1 a21191 1 source file ‘remote.c’. Normally, you can simply allow these d21194 1 a21194 1 with one of the existing stub files. ‘sparc-stub.c’ is the best d21197 4 a21200 3 To debug a program running on another machine (the debugging “target” machine), you must first arrange for all the usual prerequisites for the program to run by itself. For example, for a C program, you need: d21203 1 a21203 1 usually have a name like ‘crt0’. The startup routine may be d21216 1 a21216 1 communicate with the machine where GDB is running (the “host” machine). d21221 1 a21221 1 else is set up, you can simply use the ‘target remote’ command d21226 2 a21227 2 that implement the GDB remote serial protocol. The file containing these subroutines is called a “debugging stub”. d21230 2 a21231 2 ‘gdbserver’ instead of linking a stub into your program. *Note Using the ‘gdbserver’ Program: Server, for details. d21234 1 a21234 1 machine; for example, use ‘sparc-stub.c’ to debug programs on SPARC d21239 1 a21239 1 ‘i386-stub.c’ d21242 1 a21242 1 ‘m68k-stub.c’ d21245 1 a21245 1 ‘sh-stub.c’ d21248 1 a21248 1 ‘sparc-stub.c’ d21251 1 a21251 1 ‘sparcl-stub.c’ d21254 2 a21255 1 The ‘README’ file in the GDB distribution may list other recently d21273 2 a21274 2 ‘set_debug_traps’ This routine arranges for ‘handle_exception’ to run when your d21278 1 a21278 1 ‘handle_exception’ d21280 1 a21280 1 explicitly--the setup code arranges for ‘handle_exception’ to run d21283 1 a21283 1 ‘handle_exception’ takes control when your program stops during d21286 7 a21292 7 communications protocol is implemented; ‘handle_exception’ acts as the GDB representative on the target machine. It begins by sending summary information on the state of your program, then continues to execute, retrieving and transmitting any information GDB needs, until you execute a GDB command that makes your program resume; at that point, ‘handle_exception’ returns control to your own code on the target machine. d21294 1 a21294 1 ‘breakpoint’ d21296 2 a21297 2 breakpoint. Depending on the particular situation, this may be the only way for GDB to get control. For instance, if your target d21300 1 a21300 1 ‘handle_exception’--in effect, to GDB. On some machines, simply d21302 2 a21303 2 again, in that situation, you don't need to call ‘breakpoint’ from your own program--simply running ‘target remote’ from the host GDB d21306 1 a21306 1 Call ‘breakpoint’ if none of these is true, or if you simply want d21323 1 a21323 1 ‘int getDebugChar()’ d21325 1 a21325 1 port. It may be identical to ‘getchar’ for your target system; a d21329 1 a21329 1 ‘void putDebugChar(int)’ d21331 1 a21331 1 port. It may be identical to ‘putchar’ for your target system; a d21336 3 a21338 3 you need to use an interrupt-driven serial driver, and arrange for it to stop when it receives a ‘^C’ (‘\003’, the control-C character). That is the character which GDB uses to tell the remote system to stop. d21343 1 a21343 1 GDB reports a ‘SIGTRAP’ instead of a ‘SIGINT’). d21347 1 a21347 1 ‘void exceptionHandler (int EXCEPTION_NUMBER, void *EXCEPTION_ADDRESS)’ d21351 2 a21352 2 target system are like (for example, the processor's table might be in ROM, containing entries which point to a table in RAM). The d21367 1 a21367 1 without help from ‘exceptionHandler’. d21369 1 a21369 1 ‘void flush_i_cache()’ d21379 2 a21380 2 ‘void *memset(void *, int, int)’ This is the standard library function ‘memset’ that sets an area of d21382 1 a21382 1 ‘libc.a’, ‘memset’ can be found there; otherwise, you must either d21388 1 a21388 1 subroutines which ‘GCC’ generates as inline code. d21399 4 a21402 4 1. Make sure you have defined the supporting low-level routines (*note What You Must Do for the Stub: Bootstrapping.): ‘getDebugChar’, ‘putDebugChar’, ‘flush_i_cache’, ‘memset’, ‘exceptionHandler’. d21413 1 a21413 1 adjust ‘handle_exception’ to arrange for it to return to the d21415 2 a21416 2 your program doesn't keep hitting the initial breakpoint instead of making progress. d21419 1 a21419 1 ‘exceptionHook’. Normally you just use: d21423 2 a21424 2 but if before calling ‘set_debug_traps’, you set it to point to a function in your program, that function is called when ‘GDB’ d21426 2 a21427 2 function indicated by ‘exceptionHook’ is called with one parameter: an ‘int’ which is the exception number. d21441 1 d21494 1 a21494 1 many native BSD configurations. This is implemented as a special ‘kvm’ d21496 1 a21496 1 running kernel into GDB and connect to the ‘kvm’ target: d21500 2 a21501 2 For debugging crash dumps, provide the file name of the crash dump as an argument: d21505 1 a21505 1 Once connected to the ‘kvm’ target, the following commands are d21508 2 a21509 2 ‘kvm pcb’ Set current context from the “Process Control Block” (PCB) address. d21511 1 a21511 1 ‘kvm proc’ d21524 8 a21531 7 supported interface, the command ‘info proc’ is available to report information about the process running your program, or about any process running on your system. One supported interface is a facility called ‘/proc’ that can be used to examine the image of a running process using file-system subroutines. This facility is supported on GNU/Linux and Solaris systems. d21541 2 a21542 2 ‘info proc’ ‘info proc PROCESS-ID’ d21544 5 a21548 5 is specified by PROCESS-ID, display information about that process; otherwise display information about the program being debugged. The summary includes the debugged process ID, the command line used to invoke it, its current working directory, and its executable file's absolute file name. d21550 1 a21550 1 On some systems, PROCESS-ID can be of the form ‘[PID]/TID’ which d21553 1 a21553 1 debugged (the leading ‘/’ still needs to be present, or else GDB d21556 1 a21556 1 ‘info proc cmdline’ d21560 1 a21560 1 ‘info proc cwd’ d21564 1 a21564 1 ‘info proc exe’ d21568 1 a21568 1 ‘info proc files’ d21595 1 a21595 1 ‘info proc mappings’ d21600 2 a21601 2 systems, each memory range includes the object file which is mapped to that range. d21603 2 a21604 2 ‘info proc stat’ ‘info proc status’ d21608 1 a21608 1 time; its stack size; its ‘nice’ value; etc. These commands are d21611 2 a21612 2 For GNU/Linux systems, see the ‘proc’ man page for more information (type ‘man 5 proc’ from your shell prompt). d21614 2 a21615 2 For FreeBSD and NetBSD systems, ‘info proc stat’ is an alias for ‘info proc status’. d21617 1 a21617 1 ‘info proc all’ d21619 1 a21619 1 the above ‘info proc’ subcommands. d21621 2 a21622 2 ‘set procfs-trace’ This command enables and disables tracing of ‘procfs’ API calls. d21624 2 a21625 2 ‘show procfs-trace’ Show the current state of ‘procfs’ API call tracing. d21627 2 a21628 2 ‘set procfs-file FILE’ Tell GDB to write ‘procfs’ API trace to the named FILE. GDB d21632 2 a21633 2 ‘show procfs-file’ Show the file to which ‘procfs’ API trace is written. d21635 4 a21638 4 ‘proc-trace-entry’ ‘proc-trace-exit’ ‘proc-untrace-entry’ ‘proc-untrace-exit’ d21640 1 a21640 1 from the ‘syscall’ interface. d21642 1 a21642 1 ‘info pidlist’ d21646 1 a21646 1 ‘info meminfo’ d21657 1 a21657 1 DJGPP programs are 32-bit protected-mode programs that use the “DPMI” d21665 3 a21667 3 ‘info dos’ This is a prefix of DJGPP-specific commands which print information about the target system and important OS structures. d21669 1 a21669 1 ‘info dos sysinfo’ d21674 3 a21676 3 ‘info dos gdt’ ‘info dos ldt’ ‘info dos idt’ d21678 6 a21683 6 and Interrupt Descriptor Tables (GDT, LDT, and IDT). The descriptor tables are data structures which store a descriptor for each segment that is currently in use. The segment's selector is an index into a descriptor table; the table entry for that index holds the descriptor's base address and limit, and its attributes and access rights. d21699 3 a21701 2 (gdb) info dos ldt $ds 0x13f: base=0x11970000 limit=0x0009ffff 32-Bit Data (Read/Write, Exp-up) d21704 1 a21704 1 outside the data segment's limit (i.e. “garbled”). d21706 2 a21707 2 ‘info dos pde’ ‘info dos pte’ d21711 2 a21712 2 mapped into physical addresses. A Page Table includes an entry for every page of memory that is mapped into the program's address d21717 2 a21718 2 Without an argument, ‘info dos pde’ displays the entire Page Directory, and ‘info dos pte’ displays all the entries in all of d21720 2 a21721 2 ‘info dos pde’ command means display only that entry from the Page Directory table. An argument given to the ‘info dos pte’ command d21725 1 a21725 1 These commands are useful when your program uses “DMA” (Direct d21731 1 a21731 1 ‘info dos address-pte ADDR’ d21737 1 a21737 1 for the page where a variable ‘i’ is stored: d21739 3 a21741 7 (gdb) info dos address-pte __djgpp_base_address + (char *)&i Page Table entry for address 0x11a00d30: Base=0x02698000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0xd30 This says that ‘i’ is stored at offset ‘0xd30’ from the page whose physical base address is ‘0x02698000’, and shows all the attributes of that page. d21743 7 a21749 2 Note that you must cast the addresses of variables to a ‘char *’, since otherwise the value of ‘__djgpp_base_address’, the base d21751 3 a21753 3 added using the rules of C pointer arithmetic: if ‘i’ is declared an ‘int’, GDB will add 4 times the value of ‘__djgpp_base_address’ to the address of ‘i’. d21758 3 a21760 3 (gdb) info dos address-pte *((unsigned *)&_go32_info_block + 3) Page Table entry for address 0x29110: Base=0x00029000 Dirty Acc. Not-Cached Write-Back Usr Read-Write +0x110 d21762 3 a21764 2 (The ‘+ 3’ offset is because the transfer buffer's address is the 3rd member of the ‘_go32_info_block’ structure.) The output d21766 2 a21767 2 conventional memory 1:1, i.e. the physical (‘0x00029000’ + ‘0x110’) and linear (‘0x29110’) addresses are identical. d21775 2 a21776 2 ‘set com1base ADDR’ This command sets the base I/O port address of the ‘COM1’ serial d21779 3 a21781 3 ‘set com1irq IRQ’ This command sets the “Interrupt Request” (‘IRQ’) line to use for the ‘COM1’ serial port. d21783 2 a21784 2 There are similar commands ‘set com2base’, ‘set com3irq’, etc. for setting the port address and the ‘IRQ’ lines for the other 3 COM d21787 2 a21788 2 The related commands ‘show com1base’, ‘show com1irq’ etc. display the current settings of the base address and the ‘IRQ’ lines used d21791 1 a21791 1 ‘info serial’ d21806 5 a21810 5 MS-Windows programs that call ‘SetConsoleMode’ to switch off the special meaning of the ‘Ctrl-C’ keystroke cannot be interrupted by typing ‘C-c’. For this reason, GDB on MS-Windows supports ‘C-’ as an alternative interrupt key sequence, which can be used to interrupt the debuggee even if it ignores ‘C-c’. d21814 1 a21814 1 described in *note Non-debug DLL Symbols::. d21816 1 a21816 1 ‘info w32’ d21820 1 a21820 1 ‘info w32 selector’ d21822 1 a21822 1 ‘GetThreadSelectorEntry’ function. It takes an optional argument d21827 1 a21827 1 ‘info w32 thread-information-block’ d21830 1 a21830 1 ‘$fs’ selector for 32-bit programs and ‘$gs’ for 64-bit programs). d21832 1 a21832 1 ‘signal-event ID’ d21838 12 a21849 12 ‘HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug’ and/or ‘HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\AeDebug’ (for x86_64 versions): − ‘Debugger’ (REG_SZ) -- a command to launch the debugger. Suggested command is: ‘FULLY-QUALIFIED-PATH-TO-GDB.EXE -ex "attach %ld" -ex "signal-event %ld" -ex "continue"’. The first ‘%ld’ will be replaced by the process ID of the crashing process, the second ‘%ld’ will be replaced by the ID of the event that blocks the crashing process, waiting for GDB to attach. d21851 1 a21851 1 − ‘Auto’ (REG_SZ) -- either ‘1’ or ‘0’. ‘1’ will make the d21853 1 a21853 1 automatically, ‘0’ will cause a dialog box with "OK" and d21857 3 a21859 3 ‘set cygwin-exceptions MODE’ If MODE is ‘on’, GDB will break on exceptions that happen inside the Cygwin DLL. If MODE is ‘off’, GDB will delay recognition of d21862 2 a21863 2 primarily for debugging the Cygwin DLL itself; the default value is ‘off’ to avoid annoying GDB users with false ‘SIGSEGV’ signals. d21865 1 a21865 1 ‘show cygwin-exceptions’ d21869 3 a21871 3 ‘set new-console MODE’ If MODE is ‘on’ the debuggee will be started in a new console on next start. If MODE is ‘off’, the debuggee will be started in the d21874 1 a21874 1 ‘show new-console’ d21878 4 a21881 4 ‘set new-group MODE’ This boolean value controls whether the debuggee should start a new group or stay in the same group as the debugger. This affects the way the Windows OS handles ‘Ctrl-C’. d21883 1 a21883 1 ‘show new-group’ d21886 1 a21886 1 ‘set debugevents’ d21888 4 a21891 4 related to the debuggee seen by the debugger. This includes events that signal thread and process creation and exit, DLL loading and unloading, console interrupts, and debugging messages produced by the Windows ‘OutputDebugString’ API call. d21893 1 a21893 1 ‘set debugexec’ d21897 1 a21897 1 ‘set debugexceptions’ d21901 1 a21901 1 ‘set debugmemory’ d21905 1 a21905 1 ‘set shell’ d21909 1 a21909 1 ‘show shell’ d21912 1 d21925 1 a21925 1 ‘kernel32.dll’). When GDB doesn't recognize any debugging symbols in a d21940 7 a21946 7 DLL name, for instance ‘KERNEL32!CreateFileA’. The plain name is also entered into the symbol table, so ‘CreateFileA’ is often sufficient. In some cases there will be name clashes within a program (particularly if the executable itself includes full debugging symbols) necessitating the use of the fully qualified name when referring to the contents of the DLL. Use single-quotes around the name to avoid the exclamation mark ("!") being interpreted as a language operator. d21951 2 a21952 2 If in doubt, try the ‘info functions’ and ‘info variables’ commands or even ‘maint print msymbols’ (*note Symbols::). Here's an example: d21974 1 a21974 1 type information. All that GDB can do is guess whether a symbol refers d21976 2 a21977 2 the symbol. Also note that the actual contents of the memory contained in a DLL are not available unless the program is running. This means d21982 1 a21982 1 automatically. For this reason, it is often necessary to prefix a d21984 1 a21984 1 type information in the command. Here's an example of the type of d22006 1 a22006 1 program starts execution. However, under these circumstances, GDB can't d22008 1 a22008 1 function's frame set-up code. You can work around this by using "*&" to d22014 3 a22016 3 The author of these extensions is not entirely convinced that setting a break point within a shared DLL like ‘kernel32.dll’ is completely safe. d22027 2 a22028 2 ‘set signals’ ‘set sigs’ d22031 1 a22031 1 by this command. ‘sigs’ is a shorthand alias for ‘signals’. d22033 2 a22034 2 ‘show signals’ ‘show sigs’ d22037 6 a22042 5 ‘set signal-thread’ ‘set sigthread’ This command tells GDB which thread is the ‘libc’ signal thread. That thread is run when a signal is delivered to a running process. ‘set sigthread’ is the shorthand alias of ‘set signal-thread’. d22044 2 a22045 2 ‘show signal-thread’ ‘show sigthread’ d22049 1 a22049 1 ‘set stopped’ d22051 2 a22052 2 with the ‘SIGSTOP’ signal. The stopped process can be continued by delivering a signal to it. d22054 1 a22054 1 ‘show stopped’ d22057 1 a22057 1 ‘set exceptions’ d22063 1 a22063 1 ‘show exceptions’ d22066 7 a22072 7 ‘set task pause’ This command toggles task suspension when GDB has control. Setting it to on takes effect immediately, and the task is suspended whenever GDB gets control. Setting it to off will take effect the next time the inferior is continued. If this option is set to off, you can use ‘set thread default pause on’ or ‘set thread pause on’ (see below) to pause individual threads. d22074 1 a22074 1 ‘show task pause’ d22077 1 a22077 1 ‘set task detach-suspend-count’ d22081 1 a22081 1 ‘show task detach-suspend-count’ d22084 5 a22088 5 ‘set task exception-port’ ‘set task excp’ This command sets the task exception port to which GDB will forward exceptions. The argument should be the value of the “send rights” of the task. ‘set task excp’ is a shorthand alias. d22090 1 a22090 1 ‘set noninvasive’ d22093 2 a22094 2 same as using ‘set task pause’, ‘set exceptions’, and ‘set signals’ to values opposite to the defaults. d22096 7 a22102 7 ‘info send-rights’ ‘info receive-rights’ ‘info port-rights’ ‘info port-sets’ ‘info dead-names’ ‘info ports’ ‘info psets’ d22104 3 a22106 3 rights, receive rights, port rights, port sets, and dead names of a task. There are also shorthand aliases: ‘info ports’ for ‘info port-rights’ and ‘info psets’ for ‘info port-sets’. d22108 1 a22108 1 ‘set thread pause’ d22114 2 a22115 2 the whole task is suspended. However, if you used ‘set task pause off’ (see above), this command comes in handy to suspend only the d22118 1 a22118 1 ‘show thread pause’ d22121 1 a22121 1 ‘set thread run’ d22124 1 a22124 1 ‘show thread run’ d22127 5 a22131 5 ‘set thread detach-suspend-count’ This command sets the suspend count GDB will leave on a thread when detaching. This number is relative to the suspend count found by GDB when it notices the thread; use ‘set thread takeover-suspend-count’ to force it to an absolute value. d22133 1 a22133 1 ‘show thread detach-suspend-count’ d22136 2 a22137 2 ‘set thread exception-port’ ‘set thread excp’ d22139 2 a22140 2 overrides the port set by ‘set task exception-port’ (see above). ‘set thread excp’ is the shorthand alias. d22142 3 a22144 3 ‘set thread takeover-suspend-count’ Normally, GDB's thread suspend counts are relative to the value GDB finds when it notices each thread. This command changes the d22147 5 a22151 5 ‘set thread default’ ‘show thread default’ Each of the above ‘set thread’ commands has a ‘set thread default’ counterpart (e.g., ‘set thread default pause’, ‘set thread default exception-port’, etc.). The ‘thread default’ variety of commands d22164 1 a22164 1 ‘set debug darwin NUM’ d22168 1 a22168 1 ‘show debug darwin’ d22171 1 a22171 1 ‘set debug mach-o NUM’ d22173 1 a22173 1 is reading Darwin object files. (“Mach-O” is the file format used d22178 1 a22178 1 ‘show debug mach-o’ d22181 2 a22182 2 ‘set mach-exceptions on’ ‘set mach-exceptions off’ d22189 1 a22189 1 ‘show mach-exceptions’ d22201 1 a22201 1 version using the new ABI. As a convenience, when a system call is d22205 2 a22206 2 For example, FreeBSD 12 introduced a new variant of the ‘kevent’ system call and catching the ‘kevent’ system call by name catches both d22235 2 a22236 2 Whenever a specific embedded processor has a simulator, GDB allows to send an arbitrary command to the simulator. d22238 1 a22238 1 ‘sim COMMAND’ d22265 1 a22265 1 ‘set debug arc’ d22270 1 a22270 1 ‘show debug arc’ d22273 1 a22273 1 ‘maint print arc arc-instruction ADDRESS’ d22277 1 d22286 1 a22286 1 ‘set arm disassembler’ d22288 1 a22288 1 ‘"std"’ style is the standard style. d22290 1 a22290 1 ‘show arm disassembler’ d22293 1 a22293 1 ‘set arm apcs32’ d22296 1 a22296 1 ‘show arm apcs32’ d22299 1 a22299 1 ‘set arm fpu FPUTYPE’ d22303 1 a22303 1 ‘auto’ d22305 2 a22306 1 ‘softfpa’ d22309 2 a22310 1 ‘fpa’ d22312 2 a22313 1 ‘softvfp’ d22315 2 a22316 1 ‘vfp’ d22319 1 a22319 1 ‘show arm fpu’ d22322 1 a22322 1 ‘set arm abi’ d22325 1 a22325 1 ‘show arm abi’ d22328 1 a22328 1 ‘set arm fallback-mode (arm|thumb|auto)’ d22330 4 a22333 4 instructions are ARM or Thumb. This command controls GDB's default behavior when the symbol table is not available. The default is ‘auto’, which causes GDB to use the current execution mode (from the ‘T’ bit in the ‘CPSR’ register). d22335 1 a22335 1 ‘show arm fallback-mode’ d22338 1 a22338 1 ‘set arm force-mode (arm|thumb|auto)’ d22340 3 a22342 3 instructions are ARM or Thumb. The default is ‘auto’, which causes GDB to use the symbol table and then the setting of ‘set arm fallback-mode’. d22344 1 a22344 1 ‘show arm force-mode’ d22347 1 a22347 1 ‘set arm unwind-secure-frames’ d22353 1 a22353 1 ‘show arm unwind-secure-frames’ d22356 1 a22356 1 ‘set debug arm’ d22360 1 a22360 1 ‘show debug arm’ d22363 1 a22363 1 ‘target sim [SIMARGS] ...’ d22366 1 a22366 1 ‘--swi-support=TYPE’ d22369 7 a22375 1 values. The default value is ‘all’. d22377 3 a22379 5 ‘none’ ‘demon’ ‘angel’ ‘redboot’ ‘all’ d22387 1 a22387 1 ‘target sim [SIMARGS] ...’ d22390 1 a22390 1 ‘--skb-data-offset=OFFSET’ d22392 1 a22392 1 ‘skb_data’ field in the kernel ‘struct sk_buff’ structure. d22415 6 a22420 6 target FPGA. The Xilinx Microprocessor Debugger (XMD) program communicates with the target board using the JTAG interface and presents a ‘gdbserver’ interface to the board. By default ‘xmd’ uses port ‘1234’. (While it is possible to change this default port, it requires the use of undocumented ‘xmd’ commands. Contact Xilinx support if you need to do this.) d22424 3 a22426 3 ‘target remote :1234’ Use this command to connect to the target if you are running GDB on the same system as ‘xmd’. d22428 1 a22428 1 ‘target remote XMD-HOST:1234’ d22430 1 a22430 1 ‘xmd’ running on a different system named XMD-HOST. d22432 1 a22432 1 ‘load’ d22435 1 a22435 1 ‘set debug microblaze N’ d22438 1 a22438 1 ‘show debug microblaze N’ d22449 5 a22453 5 ‘set mipsfpu double’ ‘set mipsfpu single’ ‘set mipsfpu none’ ‘set mipsfpu auto’ ‘show mipsfpu’ d22455 1 a22455 1 coprocessor, you should use the command ‘set mipsfpu none’ (if you d22462 3 a22464 3 the command ‘set mipsfpu single’. The default double precision floating point coprocessor may be selected using ‘set mipsfpu double’. d22467 2 a22468 2 floating point, so ‘set mipsfpu on’ will select double precision and ‘set mipsfpu off’ will select no floating point. d22470 2 a22471 2 As usual, you can inquire about the ‘mipsfpu’ variable with ‘show mipsfpu’. d22479 3 a22481 3 The OpenRISC 1000 provides a free RISC instruction set architecture. It is mainly provided as a soft-core which can run on Xilinx, Altera and other FPGA's. d22486 1 a22486 2 ‘target sim’ d22488 1 a22488 1 but does not support most hardware functions like MMU. For more d22490 1 a22490 1 and connect using ‘target remote’. d22492 1 a22492 1 Example: ‘target sim’ d22494 3 a22496 3 ‘set debug or1k’ Toggle whether to display OpenRISC-specific debugging messages from the OpenRISC target support subsystem. d22498 1 a22498 1 ‘show debug or1k’ d22507 2 a22508 2 GDB supports using the DVC (Data Value Compare) register to implement in hardware simple hardware watchpoint conditions of the form: d22515 1 a22515 1 debug register (either the ‘exact-watchpoints’ option is on and the d22521 1 a22521 1 ranged hardware watchpoints, unless the ‘exact-watchpoints’ option is d22532 1 a22532 1 discussion about the ‘mask’ argument in *note Set Watchpoints::. d22534 2 a22535 2 PowerPC embedded processors support hardware accelerated “ranged breakpoints”. A ranged breakpoint stops execution of the inferior d22537 1 a22537 1 was set at. To set a ranged breakpoint in GDB, use the ‘break-range’ d22542 1 a22542 1 ‘break-range START-LOCSPEC, END-LOCSPEC’ d22555 2 a22556 2 ‘set powerpc soft-float’ ‘show powerpc soft-float’ d22561 2 a22562 2 ‘set powerpc vector-abi’ ‘show powerpc vector-abi’ d22564 5 a22568 5 arguments and return values. The valid options are ‘auto’; ‘generic’, to avoid vector registers even if they are present; ‘altivec’, to use AltiVec registers; and ‘spe’ to use SPE registers. By default, GDB selects the calling convention based on the selected architecture and the provided executable file. d22570 2 a22571 2 ‘set powerpc exact-watchpoints’ ‘show powerpc exact-watchpoints’ d22573 3 a22575 2 of scalar type, thus assuming that the variable is accessed through the address of its first byte. d22586 1 a22586 1 ‘info io_registers’ d22599 4 a22602 4 ‘set cris-version VER’ Set the current CRIS version to VER, either ‘10’ or ‘32’. The CRIS version affects register names and sizes. This command is useful in case autodetection of the CRIS version fails. d22604 1 a22604 1 ‘show cris-version’ d22607 1 a22607 1 ‘set cris-dwarf2-cfi’ d22609 2 a22610 2 ‘on’. Change to ‘off’ when using ‘gcc-cris’ whose version is below ‘R59’. d22612 1 a22612 1 ‘show cris-dwarf2-cfi’ d22615 1 a22615 1 ‘set cris-mode MODE’ d22617 2 a22618 2 debugging in guru mode, in which case it should be set to ‘guru’ (the default is ‘normal’). d22620 1 a22620 1 ‘show cris-mode’ d22631 1 a22631 1 ‘set sh calling-convention CONVENTION’ d22633 2 a22634 2 Allowed values are ‘gcc’, which is the default setting, and ‘renesas’. With the ‘gcc’ setting, functions are called using the d22638 1 a22638 1 convention. If the calling convention is set to ‘renesas’, the d22641 1 a22641 1 ‘gcc’ if debug information is missing, or the compiler does not d22644 1 a22644 1 ‘show sh calling-convention’ d22647 1 d22679 1 a22679 1 ‘set debug aarch64’ d22683 1 a22683 1 ‘show debug aarch64’ d22686 1 d22692 4 a22695 4 ‘$z0’ through ‘$z31’, vector predicate registers ‘$p0’ through ‘$p15’, and the ‘$ffr’ register. In addition, the pseudo register ‘$vg’ will be provided. This is the vector granule for the current thread and represents the number of 64-bit chunks in an SVE ‘z’ register. d22697 2 a22698 2 If the vector length changes, then the ‘$vg’ register will be updated, but the lengths of the ‘z’ and ‘p’ registers will not change. d22705 1 a22705 1 • VL: The vector length, in bytes. It defines the size of each ‘Z’ d22708 1 a22708 1 • VQ: The number of 128 bit units in VL. This is mostly used d22711 1 a22711 1 • VG: The number of 64 bit units in VL. This is mostly used d22714 1 d22723 1 a22723 1 by providing a 2-dimensional register ‘ZA’, which is a square matrix of d22727 2 a22728 2 Similarly to SVE, where the size of each ‘Z’ register is directly related to the vector length (VL for short), the SME ‘ZA’ matrix d22732 1 a22732 1 The ‘ZA’ register state can be either active or inactive, if it is d22736 4 a22739 4 (streaming mode for short). When streaming mode is enabled, the program supports execution of SVE2 instructions and the SVE registers will have vector length SVL. When streaming mode is disabled, the SVE registers have vector length VL. d22748 3 a22750 3 • SVL: The streaming vector length, in bytes. It defines the size of each dimension of the 2-dimensional square ‘ZA’ matrix. The total size of ‘ZA’ is therefore SVL by SVL. d22755 1 a22755 1 • SVQ: The number of 128 bit units in SVL, also known as streaming d22759 1 a22759 1 • SVG: The number of 64 bit units in SVL. This is mostly used d22762 1 d22764 2 a22765 2 Matrix Extension (SME) is present, then GDB will make the ‘ZA’ register available. GDB will also make the ‘SVG’ register and ‘SVCR’ d22768 2 a22769 2 The ‘ZA’ register is a 2-dimensional square SVL by SVL matrix of bytes. To simplify the representation and access to the ‘ZA’ register d22772 2 a22773 2 If the user wants to index the ‘ZA’ register as a matrix, it is possible to reference ‘ZA’ as ‘ZA[I][J]’, where I is the row number and d22776 3 a22778 3 The ‘SVG’ register always contains the streaming vector granule (SVG) for the current thread. From the value of register ‘SVG’ we can easily derive the SVL value. d22780 1 a22780 1 The ‘SVCR’ pseudo-register (streaming vector control register) is a d22783 4 a22786 4 If the SM bit is 1, it means the current thread is in streaming mode, and the SVE registers will use SVL for their sizes. If the SM bit is 0, the current thread is not in streaming mode, and the SVE registers will use VL for their sizes. *Note vl::. d22788 2 a22789 2 If the ZA bit is 1, it means the ‘ZA’ register is being used and has meaningful contents. If the ZA bit is 0, the ‘ZA’ register is d22792 2 a22793 2 For convenience and simplicity, if the ZA bit is 0, the ‘ZA’ register and all of its pseudo-registers will read as zero. d22795 2 a22796 2 If SVL changes during the execution of a program, then the ‘ZA’ register size and the bits in the ‘SVCR’ pseudo-register will be updated d22800 1 a22800 1 program by modifying the ‘SVG’ register value. d22802 1 a22802 1 Whenever the ‘SVG’ register is modified with a new value, the d22805 1 a22805 1 • The ZA and SM bits will be cleared in the ‘SVCR’ pseudo-register. d22807 1 a22807 1 • The ‘ZA’ register will have a new size and its state will be d22811 1 a22811 1 • If the SM bit was 1, the SVE registers will be reset to having d22813 1 a22813 1 prior to modifying the ‘SVG’ register, there will be no observable d22816 2 a22817 1 The possible values for the ‘SVG’ register are 2, 4, 8, 16, 32. d22821 1 a22821 1 The minimum size of the ‘ZA’ register is 16 x 16 (256) bytes, and the d22823 1 a22823 1 set, the size of the ‘ZA’ register is the size of all the SVE ‘Z’ d22826 1 a22826 1 The ‘ZA’ register can also be accessed using tiles and tile slices. d22829 1 a22829 1 elements within the ‘ZA’ register. d22831 2 a22832 2 The tile pseudo-registers have the following naming pattern: ‘ZA’. d22834 3 a22836 3 There is a total of 31 ‘ZA’ tile pseudo-registers. They are ‘ZA0B’, ‘ZA0H’ through ‘ZA1H’, ‘ZA0S’ through ‘ZA3S’, ‘ZA0D’ through ‘ZA7D’ and ‘ZA0Q’ through ‘ZA15Q’. d22839 1 a22839 1 contiguous elements within the ‘ZA’ register. d22842 1 a22842 1 ‘ZA ’. d22844 3 a22846 3 There are up to 16 tiles (0 ~ 15), the direction can be either ‘v’ (vertical) or ‘h’ (horizontal), the qualifiers can be ‘b’ (byte), ‘h’ (halfword), ‘s’ (word), ‘d’ (doubleword) and ‘q’ (quadword) and there d22852 2 a22853 2 (number of directions) x 16 (SVL) pseudo-registers. For the maximum SVL of 256 bytes, there are 5 x 2 x 256 pseudo-registers. d22856 1 a22856 1 currently-available ‘ZA’ pseudo-registers. Pseudo-registers that don't d22872 1 a22872 1 the ‘SVCR’ pseudo-register bits nor the ‘ZA’ register contents. *Note d22877 2 a22878 2 involving the ‘TPIDR2’ register is not yet supported by GDB, though the ‘TPIDR2’ register is known and supported by GDB. d22880 2 a22881 2 Lastly, an important limitation for ‘gdbserver’ is its inability to communicate SVL changes to GDB. This means ‘gdbserver’, even though it d22885 1 a22885 1 values for the ‘ZA’ register and incorrect values for SVE registers d22897 3 a22899 3 • The ability to address the ‘ZA’ array through groups of one-dimensional ‘ZA’ array vectors, as opposed to ‘ZA’ tiles with 2 dimensions. d22901 1 a22901 1 • Instructions to operate on groups of SVE ‘Z’ registers and ‘ZA’ d22904 2 a22905 1 • A new 512 bit ‘ZT0’ lookup table register, for data decompression. d22908 1 a22908 1 Matrix Extension 2 (SME2) is present, then GDB will make the ‘ZT0’ d22911 2 a22912 2 The ‘ZT0’ register is only considered active when the ‘ZA’ register state is active, therefore when the ZA bit of the ‘SVCR’ is 1. d22914 2 a22915 2 When the ZA bit of ‘SVCR’ is 0, that means the ‘ZA’ register state is not active, which means the ‘ZT0’ register state is also not active. d22917 1 a22917 1 When ‘ZT0’ is not active, it is comprised of zeroes, just like ‘ZA’. d22919 1 a22919 1 Similarly to the ‘ZA’ register, if the ‘ZT0’ state is not active and d22921 2 a22922 2 non-zero, then GDB will initialize the ‘ZA’ register state as well, which means the ‘SVCR’ ZA bit gets set to 1. d22931 6 a22936 6 When GDB is debugging the AArch64 architecture, and the program is using the v8.3-A feature Pointer Authentication (PAC), then whenever the link register ‘$lr’ is pointing to an PAC function its value will be masked. When GDB prints a backtrace, any addresses that required unmasking will be postfixed with the marker [PAC]. When using the MI, this is printed as part of the ‘addr_flags’ field. d22941 5 a22945 5 When GDB is debugging the AArch64 architecture, the program is using the v8.5-A feature Memory Tagging Extension (MTE) and there is support in the kernel for MTE, GDB will make memory tagging functionality available for inspection and editing of logical and allocation tags. *Note Memory Tagging::. d22964 4 a22967 4 A special register, ‘tag_ctl’, is made available through the ‘org.gnu.gdb.aarch64.mte’ feature. This register exposes some options that can be controlled at runtime and emulates the ‘prctl’ option ‘PR_SET_TAGGED_ADDR_CTRL’. For further information, see the d22971 2 a22972 2 ‘gcore’ command and reading memory tag data from core files generated by the ‘gcore’ command or the Linux kernel. d22980 2 a22981 2 tags from a particular memory region (using the ‘m’ modifier to the ‘x’ command, using the ‘print’ command or using the various ‘memory-tag’ d22986 2 a22987 2 above messages depending on whether the synchronous or asynchronous mode is selected. *Note Memory Tagging::. *Note Memory::. d22995 6 a23000 6 ‘set struct-convention MODE’ Set the convention used by the inferior to return ‘struct’s and ‘union’s from functions to MODE. Possible values of MODE are ‘"pcc"’, ‘"reg"’, and ‘"default"’ (the default). ‘"default"’ or ‘"pcc"’ means that ‘struct’s are returned on the stack, while ‘"reg"’ means that a ‘struct’ or a ‘union’ whose size is 1, 2, 4, d23003 3 a23005 3 ‘show struct-convention’ Show the current setting of the convention to return ‘struct’s from functions. d23007 1 a23007 1 21.4.2.1 Intel “Memory Protection Extensions” (MPX). d23010 3 a23012 3 Memory Protection Extension (MPX) adds the bound registers ‘BND0’ (1) through ‘BND3’. Bound registers store a pair of 64-bit values which are the lower bound and upper bound. Bounds are effective addresses or d23018 2 a23019 2 ‘BND0’ through ‘BND3’ are represented in GDB as ‘bnd0raw’ through ‘bnd3raw’. Pseudo registers ‘bnd0’ through ‘bnd3’ display the upper d23021 3 a23023 3 value, i.e. when upper bound in ‘bnd0raw’ is 0 in the GDB ‘bnd0’ it will be ‘0xfff...’. In this sense it can also be noted that the upper bounds are inclusive. d23040 4 a23043 4 specifying the bounds pointer's value along with its bounds. Evaluating and changing bounds located in bound tables is therefore interesting while investigating bugs on MPX context. GDB provides commands for this purpose: d23045 1 a23045 1 ‘show mpx bound POINTER’ d23048 5 a23052 5 ‘set mpx bound POINTER, LBOUND, UBOUND’ Set the bounds of a pointer in the bound table. This command takes three parameters: POINTER is the pointers whose bounds are to be changed, LBOUND and UBOUND are new values for lower and upper bounds respectively. d23069 3 a23071 3 execution of the called function by stopping the execution of the called function at its prologue, setting bound registers, and continuing the execution. For example: d23081 3 a23083 3 of bound violations caused along the execution of the call. In order to know how to set the bound registers or bound table for the call consult the ABI. d23090 18 a23107 9 • ‘$st0’ to ‘st7’: ‘ST(0)’ to ‘ST(7)’ floating-point registers • ‘$fctrl’: control word register (‘FCW’) • ‘$fstat’: status word register (‘FSW’) • ‘$ftag’: tag word (‘FTW’) • ‘$fiseg’: last instruction pointer segment • ‘$fioff’: last instruction pointer • ‘$foseg’: last data pointer segment • ‘$fooff’: last data pointer • ‘$fop’: last opcode d23129 2 a23130 2 sometimes requires GDB to search backward in the object code to find the beginning of a function. d23136 7 a23142 7 ‘set heuristic-fence-post LIMIT’ Restrict GDB to examining at most LIMIT bytes in its search for the beginning of a function. A value of 0 (the default) means there is no limit. However, except for 0, the larger the limit the more bytes ‘heuristic-fence-post’ must search and therefore the longer it takes to run. You should only need to use this command when debugging a stripped executable. d23144 1 a23144 1 ‘show heuristic-fence-post’ d23147 2 a23148 2 These commands are available _only_ when GDB is configured for debugging programs on Alpha or MIPS processors. d23153 1 a23153 1 ‘set mips abi ARG’ d23157 1 a23157 1 ‘auto’ a23159 6 ‘o32’ ‘o64’ ‘n32’ ‘n64’ ‘eabi32’ ‘eabi64’ d23161 13 a23173 1 ‘show mips abi’ d23176 1 a23176 1 ‘set mips compression ARG’ d23185 2 a23186 2 Possible values of ARG are ‘mips16’ and ‘micromips’. The default compressed ISA encoding is ‘mips16’, as executables containing d23199 1 a23199 1 ‘show mips compression’ d23203 2 a23204 2 ‘set mipsfpu’ ‘show mipsfpu’ d23207 1 a23207 1 ‘set mips mask-address ARG’ d23210 1 a23210 1 ‘on’, ‘off’, or ‘auto’. The latter is the default setting, which d23213 1 a23213 1 ‘show mips mask-address’ d23217 1 a23217 1 ‘set remote-mips64-transfers-32bit-regs’ d23221 1 a23221 1 and 64 bits for other registers, set this option to ‘on’. d23223 1 a23223 1 ‘show remote-mips64-transfers-32bit-regs’ d23227 1 a23227 1 ‘set debug mips’ d23231 1 a23231 1 ‘show debug mips’ d23243 1 a23243 1 ‘set debug hppa’ d23247 1 a23247 1 ‘show debug hppa’ d23250 1 a23250 1 ‘maint print unwind ADDRESS’ d23254 1 d23263 1 a23263 1 Point numbers stored in the floating point registers. These values must d23265 1 a23265 1 register like ‘f0’ or ‘f2’. d23267 3 a23269 3 The pseudo-registers go from ‘$dl0’ through ‘$dl15’, and are formed by joining the even/odd register pairs ‘f0’ and ‘f1’ for ‘$dl0’, ‘f2’ and ‘f3’ for ‘$dl1’ and so on. d23272 1 a23272 1 64-bit wide Extended Floating Point Registers (‘f32’ through ‘f63’). d23283 1 a23283 1 ‘set debug nios2’ d23287 1 a23287 1 ‘show debug nios2’ d23302 8 a23309 8 sets the version in the upper 4 bits of the 64-bit pointer to that data, and stores the 4-bit version in every cacheline of that data. Hardware saves the latter in spare bits in the cache and memory hierarchy. On each load and store, the processor compares the upper 4 VA (virtual address) bits to the cacheline's version. If there is a mismatch, the processor generates a version mismatch trap which can be either precise or disrupting. The trap is an error condition which the kernel delivers to the process as a SIGSEGV signal. d23317 3 a23319 4 ‘adi (examine | x) [ / N ] ADDR’ The ‘adi examine’ command displays the value of one ADI version tag per cacheline. d23334 2 a23335 3 ‘adi (assign | a) [ / N ] ADDR = TAG’ The ‘adi assign’ command is used to assign new ADI version tag to d23354 1 d23364 1 a23364 1 ‘maint info bdccsr’ d23401 2 a23402 2 displayed if an unsupported AMD ROCm runtime is detected, or there is an error or restriction that prevents debugging. GDB will continue to d23422 1 a23422 1 The ‘info sharedlibrary’ command will show the AMD GPU code objects as d23437 10 a23446 10 For a ‘file’ URI, the path portion is the file on disk containing the code object. The OFFSET parameter is a 0-based offset in this file, to the start of the code object. If omitted, it defaults to 0. The SIZE parameter is the size of the code object in bytes. If omitted, it defaults to the size of the file. For a ‘memory’ URI, the path portion is the process id of the process owning the memory containing the code object. The OFFSET parameter is the memory address where the code object is found, and the SIZE parameter is its size in bytes. d23449 4 a23452 4 The ‘info sharedlibrary’ command may therefore show the same code object loaded multiple times. As a consequence, setting a breakpoint in AMD GPU code will result in multiple breakpoint locations if there are multiple AMD GPU devices. d23465 1 d23472 1 a23472 1 ‘SIGILL’ d23475 4 a23478 2 ‘SIGTRAP’ Execution of a ‘S_TRAP’ instruction other than: d23480 1 a23480 1 • ‘S_TRAP 1’ which is used by GDB to insert breakpoints. a23481 1 • ‘S_TRAP 2’ which raises ‘SIGABRT’. d23483 2 a23484 2 ‘SIGABRT’ Execution of a ‘S_TRAP 2’ instruction. d23486 1 a23486 1 ‘SIGFPE’ d23491 1 a23491 1 • Floating point operation is invalid. d23493 1 a23493 1 • Floating point operation had subnormal input that was rounded d23496 1 a23496 1 • Floating point operation performed a division by zero. d23498 1 a23498 1 • Floating point operation produced an overflow result. The d23501 1 a23501 1 • Floating point operation produced an underflow result. A d23504 3 a23506 1 • Floating point operation produced an inexact result. a23507 1 • Integer operation performed a division by zero. d23510 1 a23510 1 ‘set $mode’ command can be used to change the AMD GPU wavefront's d23512 3 a23514 3 raise signals. The ‘print $trapsts’ command can be used to inspect which conditions have been detected even if they are not enabled to raise a signal. d23516 1 a23516 1 ‘SIGBUS’ d23520 5 a23524 3 ‘SIGSEGV’ Execution of an instruction that accessed a global memory page that is either not mapped or accessed with incompatible permissions. d23538 1 a23538 1 ‘set amdgpu precise-memory MODE’ d23542 1 a23542 1 ‘off’ d23547 1 a23547 1 ‘on’ d23549 4 a23552 4 the instruction that caused a memory violation. Enabling this mode may make the AMD GPU device execution significantly slower as it has to wait for each memory operation to complete before executing the next instruction. d23554 3 a23556 2 The ‘amdgpu precise-memory’ parameter is per-inferior. When an inferior forks or execs, or the user uses the ‘clone-inferior’ d23560 1 a23560 1 ‘show amdgpu precise-memory’ d23563 1 d23567 2 a23568 2 The ‘set debug amd-dbgapi’ command can be used to enable diagnostic messages in the ‘amd-dbgapi’ target. The ‘show debug amd-dbgapi’ d23571 5 a23575 5 The ‘set debug amd-dbgapi-lib log-level LEVEL’ command can be used to enable diagnostic messages from the ‘amd-dbgapi’ library (which GDB uses under the hood). The ‘show debug amd-dbgapi-lib log-level’ command displays the current ‘amd-dbgapi’ library log level. *Note set debug amd-dbgapi-lib::. d23600 2 a23601 2 Setting the ‘HIP_ENABLE_DEFERRED_LOADING’ environment variable to ‘0’ can be used to disable deferred code object loading by the HIP d23603 1 a23603 1 inferior reaches the beginning of the ‘main’ function. d23605 1 a23605 1 3. If no CPU thread is running, then ‘Ctrl-C’ is not able to stop AMD d23607 3 a23609 3 ‘scheduler-locking’ after the whole program stopped, and then resume an AMD GPU thread. The only way to unblock the situation is to kill the GDB process. d23611 1 a23611 2 4. By default, for some architectures, the AMD GPU device driver d23614 2 a23615 2 the wavefront's work-group position. The ‘info threads’ command will display this missing information with a ‘?’. d23620 1 a23620 1 If the ‘HSA_ENABLE_DEBUG’ environment variable is set to ‘1’ when d23625 1 d23632 3 a23634 3 You can alter the way GDB interacts with you by using the ‘set’ command. For commands controlling how GDB displays data, see *note Print Settings: Print Settings. Other settings are described here. d23657 2 a23658 2 called the “prompt”. This string is normally ‘(gdb)’. You can change the prompt string with the ‘set prompt’ command. For instance, when d23662 1 a23662 1 _Note:_ ‘set prompt’ does not add a space for you after the prompt d23666 1 a23666 1 ‘set prompt NEWPROMPT’ d23669 2 a23670 2 ‘show prompt’ Prints a line of the form: ‘Gdb's prompt is: YOUR-PROMPT’ d23675 1 a23675 1 ‘set extended-prompt PROMPT’ d23689 4 a23692 4 ‘show extended-prompt’ Prints the extended prompt. Any escape sequences specified as part of the prompt string with ‘set extended-prompt’, are replaced with the corresponding strings each time the prompt is displayed. d23700 1 a23700 1 GDB reads its input commands via the “Readline” interface. This GNU d23703 1 a23703 1 “vi”-style inline editing of commands, ‘csh’-like history substitution, d23707 1 a23707 1 command ‘set’. d23709 2 a23710 2 ‘set editing’ ‘set editing on’ d23713 1 a23713 1 ‘set editing off’ d23716 1 a23716 1 ‘show editing’ d23720 1 a23720 1 interface. Users unfamiliar with GNU Emacs or ‘vi’ are encouraged to d23723 2 a23724 2 GDB sets the Readline application name to ‘gdb’. This is useful for conditions in ‘.inputrc’. d23726 2 a23727 2 GDB defines a bindable Readline command, ‘operate-and-get-next’. This is bound to ‘C-o’ by default. This command accepts the current d23746 1 a23746 1 state which is seen by users, prefix it with ‘server ’ (*note Server d23753 1 a23753 1 history, use the ‘output’ command instead of the ‘print’ command. d23757 14 a23770 13 ‘set history filename [FNAME]’ Set the name of the GDB command history file to FNAME. This is the file where GDB reads an initial command history list, and where it writes the command history from this session when it exits. You can access this list through history expansion or through the history command editing characters listed below. This file defaults to the value of the environment variable ‘GDBHISTFILE’, or to ‘./.gdb_history’ (‘./_gdb_history’ on MS-DOS) if this variable is not set. The ‘GDBHISTFILE’ environment variable is read after processing any GDB initialization files (*note Startup::) and after processing any commands passed using command line options (for example, ‘-ex’). d23772 1 a23772 1 If the FNAME argument is not given, or if the ‘GDBHISTFILE’ is the d23776 2 a23777 2 ‘set history save’ ‘set history save on’ d23779 8 a23786 8 the ‘set history filename’ command. By default, this option is disabled. The command history will be recorded when GDB exits. If ‘set history filename’ is set to the empty string then history saving is disabled, even when ‘set history save’ is ‘on’. ‘set history save off’ Don't record the command history into the file specified by ‘set history filename’ when GDB exits. d23788 2 a23789 2 ‘set history size SIZE’ ‘set history size unlimited’ d23792 10 a23801 8 ‘GDBHISTSIZE’, or to 256 if this variable is not set. Non-numeric values of ‘GDBHISTSIZE’ are ignored. If SIZE is ‘unlimited’ or if ‘GDBHISTSIZE’ is either a negative number or the empty string, then the number of commands GDB keeps in the history list is unlimited. The ‘GDBHISTSIZE’ environment variable is read after processing any GDB initialization files (*note Startup::) and after processing any commands passed using command line options (for example, ‘-ex’). d23803 2 a23804 2 ‘set history remove-duplicates COUNT’ ‘set history remove-duplicates unlimited’ d23806 2 a23807 2 history list. If COUNT is non-zero, GDB will look back at the last COUNT history entries and remove the first entry that is a d23809 1 a23809 1 list. If COUNT is ‘unlimited’ then this lookbehind is unbounded. d23816 2 a23817 1 History expansion assigns special meaning to the character ‘!’. d23820 7 a23826 7 Since ‘!’ is also the logical not operator in C, history expansion is off by default. If you decide to enable history expansion with the ‘set history expansion on’ command, you may sometimes need to follow ‘!’ (when it is used as logical not, in an expression) with a space or a tab to prevent it from being expanded. The readline history facilities do not attempt substitution on the strings ‘!=’ and ‘!(’, even when history expansion is enabled. d23830 2 a23831 2 ‘set history expansion on’ ‘set history expansion’ d23834 1 a23834 1 ‘set history expansion off’ d23837 5 a23841 5 ‘show history’ ‘show history filename’ ‘show history save’ ‘show history size’ ‘show history expansion’ d23843 1 a23843 1 ‘show history’ by itself displays all four states. d23845 1 a23845 1 ‘show commands’ d23848 1 a23848 1 ‘show commands N’ d23851 1 a23851 1 ‘show commands +’ d23863 3 a23865 3 see one more page of output, ‘q’ to discard the remaining output, or ‘c’ to continue without paging for the rest of the current command. Also, the screen width setting determines when to wrap lines of output. d23872 12 a23883 12 with the value of the ‘TERM’ environment variable and the ‘stty rows’ and ‘stty cols’ settings. If this is not correct, you can override it with the ‘set height’ and ‘set width’ commands: ‘set height LPP’ ‘set height unlimited’ ‘show height’ ‘set width CPL’ ‘set width unlimited’ ‘show width’ These ‘set’ commands specify a screen height of LPP lines and a screen width of CPL characters. The associated ‘show’ commands d23886 1 a23886 1 If you specify a height of either ‘unlimited’ or zero lines, GDB d23890 2 a23891 2 Likewise, you can specify ‘set width unlimited’ or ‘set width 0’ to prevent GDB from wrapping its output. d23893 2 a23894 2 ‘set pagination on’ ‘set pagination off’ d23896 2 a23897 2 pagination off is the alternative to ‘set height unlimited’. Note that running GDB with the ‘--batch’ option (*note -batch: Mode d23900 1 a23900 1 ‘show pagination’ d23914 1 a23914 1 ‘set style enabled ‘on|off’’ d23916 1 a23916 1 most hosts defaulting to ‘on’. d23918 2 a23919 2 If the ‘NO_COLOR’ environment variable is set to a non-empty value, then GDB will change this to ‘off’ at startup. d23921 1 a23921 1 ‘show style enabled’ d23924 1 a23924 1 ‘set style sources ‘on|off’’ d23926 3 a23928 3 code, such as the output of the ‘list’ command, is styled. The default is ‘on’. Note that source styling only works if styling in general is enabled, and if a source highlighting library is d23933 3 a23935 2 Otherwise, if GDB was configured with Python scripting support, and if the Python Pygments package is available, then it will be used. d23937 1 a23937 1 ‘show style sources’ d23940 1 a23940 1 ‘set style tui-current-position ‘on|off’’ d23943 1 a23943 1 is ‘off’. *Note GDB Text User Interface: TUI. d23945 1 a23945 1 ‘show style tui-current-position’ d23949 1 a23949 1 ‘set style disassembler enabled ‘on|off’’ d23951 1 a23951 1 disassembler output, such as the output of the ‘disassemble’ d23953 1 a23953 1 general is enabled (with ‘set style enabled on’), and if a source d23967 2 a23968 2 possible. In order to use the Python Pygments package, GDB must be built with Python support, and the Pygments package must be d23972 1 a23972 1 unstyled disassembler output, even when this setting is ‘on’. d23975 2 a23976 2 builtin disassembler library see *note ‘maint show libopcodes-styling enabled’: maint_libopcodes_styling. d23978 1 a23978 1 ‘show style disassembler enabled’ d23981 2 a23982 1 Subcommands of ‘set style’ control specific forms of styling. These d23986 2 a23987 2 For example, the style of file names can be controlled using the ‘set style filename’ group of commands: d23989 18 a24006 18 ‘set style filename background COLOR’ Set the background to COLOR. Valid colors are ‘none’ (meaning the terminal's default color), ‘black’, ‘red’, ‘green’, ‘yellow’, ‘blue’, ‘magenta’, ‘cyan’, and‘white’. ‘set style filename foreground COLOR’ Set the foreground to COLOR. Valid colors are ‘none’ (meaning the terminal's default color), ‘black’, ‘red’, ‘green’, ‘yellow’, ‘blue’, ‘magenta’, ‘cyan’, and‘white’. ‘set style filename intensity VALUE’ Set the intensity to VALUE. Valid intensities are ‘normal’ (the default), ‘bold’, and ‘dim’. The ‘show style’ command and its subcommands are styling a style name in their output using its own style. So, use ‘show style’ to see the complete list of styles, their characteristics and the visual aspect of each style. d24009 1 a24009 1 ‘filename’ d24013 1 a24013 1 ‘function’ d24015 1 a24015 1 ‘set style function’ family of commands. By default, this style's d24020 1 a24020 1 (*note ‘set style disassembler enabled’: d24023 1 a24023 1 ‘variable’ d24025 1 a24025 1 ‘set style variable’ family of commands. By default, this style's d24028 3 a24030 3 ‘address’ Control the styling of addresses. These are managed with the ‘set style address’ family of commands. By default, this style's d24034 3 a24036 2 if GDB is using its builtin disassembler library for styling (*note ‘set style disassembler enabled’: style_disassembler_enabled.). d24038 5 a24042 5 ‘version’ Control the styling of GDB's version number text. By default, this style's foreground color is magenta and it has bold intensity. The version number is displayed in two places, the output of ‘show version’, and when GDB starts up. d24045 1 a24045 1 add the ‘set style version’ family of commands to the early d24048 3 a24050 3 ‘title’ Control the styling of titles. These are managed with the ‘set style title’ family of commands. By default, this style's d24053 1 a24053 1 ‘apropos’ and ‘help’ are using the title style for the command d24056 1 a24056 1 ‘highlight’ d24058 4 a24061 4 ‘set style highlight’ family of commands. By default, this style's foreground color is red. Commands are using the highlight style to draw the user attention to some specific parts of their output. For example, the command ‘apropos -v REGEXP’ uses the highlight d24064 1 a24064 1 ‘metadata’ d24067 5 a24071 5 annotations include the ‘repeats N times’ annotation for suppressed display of repeated array elements (*note Print Settings::), ‘’ and ‘’ annotations for errors and ‘’ annotations for optimized-out values in displaying stack frame information in backtraces (*note d24074 1 a24074 1 ‘tui-border’ d24077 1 a24077 1 ‘set style’. This was done for compatibility reasons, as TUI d24081 1 a24081 1 ‘tui-active-border’ d24085 1 a24085 1 ‘disassembler comment’ d24087 1 a24087 1 are managed with the ‘set style disassembler comment’ family of d24089 2 a24090 2 builtin disassembler library (*note ‘set style disassembler enabled’: style_disassembler_enabled.). By default, this style's d24093 1 a24093 1 ‘disassembler immediate’ d24095 1 a24095 1 These are managed with the ‘set style disassembler immediate’ d24097 2 a24098 2 operands that represent addresses, in that case the ‘disassembler address’ style is used. This style is only used when GDB is d24102 1 a24102 1 ‘disassembler address’ d24104 1 a24104 1 This is an alias for the ‘address’ style. d24106 1 a24106 1 ‘disassembler symbol’ d24108 1 a24108 1 This is an alias for the ‘function’ style. d24110 1 a24110 1 ‘disassembler mnemonic’ d24112 3 a24114 3 output. These are managed with the ‘set style disassembler mnemonic’ family of commands. This style is also used for assembler directives, e.g. ‘.byte’, ‘.word’, etc. This style is d24118 1 a24118 1 ‘disassembler register’ d24120 2 a24121 2 output. These are managed with the ‘set style disassembler register’ family of commands. This style is only used when GDB is d24125 1 d24132 13 a24144 12 You can always enter numbers in octal, decimal, or hexadecimal in GDB by the usual conventions: octal numbers begin with ‘0’, decimal numbers end with ‘.’, and hexadecimal numbers begin with ‘0x’. Numbers that neither begin with ‘0’ or ‘0x’, nor end with a ‘.’ are, by default, entered in base 10; likewise, the default display for numbers--when no particular format is specified--is base 10. You can change the default base for both input and output with the commands described below. ‘set input-radix BASE’ Set the default base for numeric input. Supported choices for BASE are decimal 8, 10, or 16. The base must itself be specified either unambiguously or using the current input radix; for example, any of d24150 6 a24155 6 sets the input base to decimal. On the other hand, ‘set input-radix 10’ leaves the input radix unchanged, no matter what it was, since ‘10’, being without any leading or trailing signs of its base, is interpreted in the current radix. Thus, if the current radix is 16, ‘10’ is interpreted in hex, i.e. as 16 decimal, which doesn't change the radix. d24157 1 a24157 1 ‘set output-radix BASE’ d24162 1 a24162 1 ‘show input-radix’ d24165 1 a24165 1 ‘show output-radix’ d24168 2 a24169 2 ‘set radix [BASE]’ ‘show radix’ d24171 1 a24171 1 output of numbers. ‘set radix’ sets the radix of input and output d24175 1 d24182 1 a24182 1 GDB can determine the “ABI” (Application Binary Interface) of your d24189 2 a24190 2 will autodetect the “OS ABI” (Operating System ABI) in use, but you can override its conclusion using the ‘set osabi’ command. One example d24197 3 a24199 3 "Newlib" OS ABI. This is useful for handling ‘setjmp’ and ‘longjmp’ when debugging binaries that use the NEWLIB C library. The "Newlib" OS ABI can be selected by ‘set osabi Newlib’. d24201 1 a24201 1 ‘show osabi’ d24204 1 a24204 1 ‘set osabi’ d24207 1 a24207 1 ‘set osabi ABI’ d24210 1 a24210 1 Generally, the way that an argument of type ‘float’ is passed to a d24212 4 a24215 4 prototyped (i.e. ANSI/ISO style) function, ‘float’ arguments are passed unchanged, according to the architecture's convention for ‘float’. For unprototyped (i.e. K&R style) functions, ‘float’ arguments are first promoted to type ‘double’ and then passed. d24218 7 a24224 6 indicate whether a function is prototyped. If GDB calls a function that is not marked as prototyped, it consults ‘set coerce-float-to-double’. ‘set coerce-float-to-double’ ‘set coerce-float-to-double on’ Arguments of type ‘float’ will be promoted to ‘double’ when passed d24227 2 a24228 2 ‘set coerce-float-to-double off’ Arguments of type ‘float’ will be passed directly to unprototyped d24231 2 a24232 2 ‘show coerce-float-to-double’ Show the current setting of promoting ‘float’ to ‘double’. d24236 5 a24240 5 application. GDB only fully supports programs with a single C++ ABI; if your program contains code using multiple C++ ABI's or if GDB can not identify your program's ABI correctly, you can tell GDB which ABI to use. Currently supported ABI's include "gnu-v2", for ‘g++’ versions before 3.0, "gnu-v3", for ‘g++’ versions 3.0 and later, and "hpaCC" for d24244 1 a24244 1 ‘show cp-abi’ d24247 1 a24247 1 ‘set cp-abi’ d24250 2 a24251 2 ‘set cp-abi ABI’ ‘set cp-abi auto’ d24262 1 a24262 1 “auto-loading”. While auto-loading is useful for automatically adapting d24272 1 a24272 1 ‘.gdbinit’ file) requires accordingly configured ‘auto-load safe-path’ d24278 3 a24280 3 ‘set auto-load off’ Globally disable loading of all auto-loaded files. You may want to use this command with the ‘-iex’ option (*note Option d24288 2 a24289 2 files, use the ‘-nx’ option (*note Mode Options::), in addition to ‘set auto-load no’. d24291 2 a24292 2 ‘show auto-load’ Show whether auto-loading of each specific ‘auto-load’ file(s) is d24306 2 a24307 2 ‘info auto-load’ Print whether each specific ‘auto-load’ file(s) have been d24324 1 a24324 2 *Note show auto-load::. Show setting of all kinds of files. d24327 1 a24327 2 *Note show auto-load gdb-scripts::. Show setting of GDB command scripts. d24329 6 a24334 4 *Note set auto-load python-scripts::.Control for GDB Python scripts. *Note show auto-load python-scripts::.Show setting of GDB Python scripts. *Note info auto-load python-scripts::.Show state of GDB Python scripts. d24336 10 a24345 8 *Note show auto-load guile-scripts::.Show setting of GDB Guile scripts. *Note info auto-load guile-scripts::.Show state of GDB Guile scripts. *Note set auto-load scripts-directory::.Control for GDB auto-loaded scripts location. *Note show auto-load scripts-directory::.Show GDB auto-loaded scripts location. *Note add-auto-load-scripts-directory::.Add directory for auto-loaded scripts location list. d24348 4 a24351 4 *Note show auto-load local-gdbinit::.Show setting of init file in the current directory. *Note info auto-load local-gdbinit::.Show state of init file in the current directory. d24362 2 a24363 2 *Note add-auto-load-safe-path::. Add directory trusted for automatic loading. d24367 2 a24368 2 * Init File in the Current Directory:: ‘set/show/info auto-load local-gdbinit’ * libthread_db.so.1 file:: ‘set/show/info auto-load libthread-db’ d24370 2 a24371 2 * Auto-loading safe path:: ‘set/show/info auto-load safe-path’ * Auto-loading verbose mode:: ‘set/show debug auto-load’ d24379 3 a24381 3 By default, GDB reads and executes the canned sequences of commands from init file (if any) in the current working directory, see *note Init File in the Current Directory during Startup::. d24383 2 a24384 2 Note that loading of this local ‘.gdbinit’ file also requires accordingly configured ‘auto-load safe-path’ (*note Auto-loading safe d24387 1 a24387 1 ‘set auto-load local-gdbinit [on|off]’ d24391 3 a24393 3 ‘show auto-load local-gdbinit’ Show whether auto-loading of canned sequences of commands from init file in the current directory is enabled or disabled. d24395 1 a24395 1 ‘info auto-load local-gdbinit’ d24410 2 a24411 2 The special ‘libthread-db-search-path’ entry ‘$sdir’ is processed without checking this ‘set auto-load libthread-db’ switch as system d24413 2 a24414 2 ‘libthread-db-search-path’ entries GDB checks first if ‘set auto-load libthread-db’ is enabled before trying to open such thread debugging d24417 3 a24419 2 Note that loading of this debugging library also requires accordingly configured ‘auto-load safe-path’ (*note Auto-loading safe path::). d24421 1 a24421 1 ‘set auto-load libthread-db [on|off]’ d24425 1 a24425 1 ‘show auto-load libthread-db’ d24429 1 a24429 1 ‘info auto-load libthread-db’ d24442 1 a24442 1 automatically. GDB provides the ‘set auto-load safe-path’ setting to d24466 1 a24466 1 ‘set auto-load safe-path [DIRECTORIES]’ d24469 5 a24473 5 specific trusted file. Each directory can also be a shell wildcard pattern; wildcards do not match directory separator - see ‘FNM_PATHNAME’ for system function ‘fnmatch’ (*note fnmatch: (libc)Wildcard Matching.). If you omit DIRECTORIES, ‘auto-load safe-path’ will be reset to its default value as specified during d24476 3 a24478 3 The list of directories uses path separator (‘:’ on GNU and Unix systems, ‘;’ on MS-Windows and MS-DOS) to separate directories, similarly to the ‘PATH’ environment variable. d24480 1 a24480 1 ‘show auto-load safe-path’ d24484 1 a24484 1 ‘add-auto-load-safe-path’ d24490 6 a24495 6 This variable defaults to what ‘--with-auto-load-dir’ has been configured to (*note with-auto-load-dir::). ‘$debugdir’ and ‘$datadir’ substitution applies the same as for *note set auto-load scripts-directory::. The default ‘set auto-load safe-path’ value can be also overridden by GDB configuration option ‘--with-auto-load-safe-path’. d24497 1 a24497 1 Setting this variable to ‘/’ disables this security protection, d24499 6 a24504 6 ‘--without-auto-load-safe-path’. This variable is supposed to be set to the system directories writable by the system superuser only. Users can add their source directories in init files in their home directories (*note Home Directory Init File::). See also deprecated init file in the current directory (*note Init File in the Current Directory during Startup::). d24509 1 a24509 1 ‘~/.gdbinit’: ‘add-auto-load-safe-path ~/src/gdb’ d24512 1 a24512 1 displayed by by ‘show auto-load safe-path’ (such as ‘/usr:/bin’ in d24515 1 a24515 1 ‘gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" ...’ d24519 4 a24522 4 ‘gdb -iex "set auto-load safe-path /" ...’ Disable auto-loading safety for a single GDB session. This assumes all the files you debug during this GDB session will come from trusted sources. d24524 1 a24524 1 ‘./configure --without-auto-load-safe-path’ d24532 1 a24532 1 ‘gdb -iex "set auto-load no" ...’ d24535 1 a24535 1 ‘~/.gdbinit’: ‘set auto-load no’ d24542 2 a24543 2 names into their canonical form (typically resolving symbolic links) and compare the entries again. GDB already canonicalizes most of the d24574 1 a24574 1 ‘set debug auto-load [on|off]’ d24577 1 a24577 1 ‘show debug auto-load’ d24588 1 a24588 1 on a slow machine, you may want to use the ‘set verbose’ command. This d24592 1 a24592 1 Currently, the messages controlled by ‘set verbose’ are those which d24594 1 a24594 1 ‘symbol-file’ in *note Commands to Specify Files: Files. d24596 1 a24596 1 ‘set verbose on’ d24599 1 a24599 1 ‘set verbose off’ d24602 2 a24603 2 ‘show verbose’ Displays whether ‘set verbose’ is on or off. d24610 1 a24610 1 ‘set complaints LIMIT’ d24616 1 a24616 1 ‘show complaints’ d24619 1 d24631 1 a24631 1 ‘set confirm off’ d24633 1 a24633 1 ‘--batch’ option (*note -batch: Mode Options.) also automatically d24636 1 a24636 1 ‘set confirm on’ d24639 1 a24639 1 ‘show confirm’ d24642 1 d24644 2 a24645 2 find it useful to enable “command tracing”. In this mode each command will be printed as it is executed, prefixed with one or more ‘+’ d24648 1 a24648 1 ‘set trace-commands on’ d24650 2 a24651 1 ‘set trace-commands off’ d24653 2 a24654 1 ‘show trace-commands’ d24668 1 a24668 1 ‘set exec-done-display’ d24670 4 a24673 3 completion. When on, GDB will print a message when an asynchronous command finishes its execution. The default is off. ‘show exec-done-display’ d24677 1 a24677 1 ‘set debug aarch64’ d24679 1 a24679 4 AArch64. The default is off. ‘show debug aarch64’ Displays the current state of displaying debugging messages related to ARM AArch64. d24681 5 a24685 1 ‘set debug arch’ d24688 2 a24689 1 ‘show debug arch’ d24692 1 a24692 1 ‘set debug aix-thread’ d24695 2 a24696 1 ‘show debug aix-thread’ d24699 4 a24702 5 ‘set debug amd-dbgapi-lib’ ‘show debug amd-dbgapi-lib’ The ‘set debug amd-dbgapi-lib log-level LEVEL’ command can be used to enable diagnostic messages from the ‘amd-dbgapi’ library, where d24705 1 a24705 1 ‘off’ d24708 1 a24708 1 ‘error’ d24711 1 a24711 1 ‘warning’ d24714 1 a24714 1 ‘info’ d24717 1 a24717 1 ‘verbose’ d24720 2 a24721 1 The ‘show debug amd-dbgapi-lib log-level’ command displays the d24724 5 a24728 6 ‘set debug amd-dbgapi’ ‘show debug amd-dbgapi’ The ‘set debug amd-dbgapi’ command can be used to enable diagnostic messages in the ‘amd-dbgapi’ target. The ‘show debug amd-dbgapi’ command displays the current setting. *Note set debug d24731 1 a24731 1 ‘set debug check-physname’ d24738 2 a24739 1 ‘show debug check-physname’ d24742 1 a24742 1 ‘set debug coff-pe-read’ d24745 10 a24754 8 ‘show debug coff-pe-read’ Displays the current state of displaying debugging messages related to reading of COFF/PE exported symbols. ‘set debug dwarf-die’ Dump DWARF DIEs after they are read in. The value is the number of nesting levels to print. A value of zero turns off the display. ‘show debug dwarf-die’ d24757 1 a24757 1 ‘set debug dwarf-line’ d24762 2 a24763 1 ‘show debug dwarf-line’ d24766 1 a24766 1 ‘set debug dwarf-read’ d24771 2 a24772 1 ‘show debug dwarf-read’ d24775 1 a24775 1 ‘set debug displaced’ a24777 3 ‘show debug displaced’ Displays the current state of displaying GDB debugging info related to displaced stepping. d24779 5 a24783 1 ‘set debug event’ d24786 2 a24787 1 ‘show debug event’ d24790 1 a24790 1 ‘set debug event-loop’ d24792 2 a24793 2 possible values are ‘off’, ‘all’ (shows all debugging info) and ‘all-except-ui’ (shows all debugging info except those about d24795 2 a24796 1 ‘show debug event-loop’ d24800 1 a24800 1 ‘set debug expression’ d24803 2 a24804 1 ‘show debug expression’ d24808 1 a24808 1 ‘set debug fbsd-lwp’ d24811 2 a24812 1 ‘show debug fbsd-lwp’ d24815 1 a24815 1 ‘set debug fbsd-nat’ d24817 2 a24818 1 ‘show debug fbsd-nat’ d24821 1 a24821 1 ‘set debug fortran-array-slicing’ d24825 1 a24825 1 ‘show debug fortran-array-slicing’ d24829 1 a24829 1 ‘set debug frame’ d24832 2 a24833 1 ‘show debug frame’ d24836 1 a24836 1 ‘set debug gnu-nat’ d24838 2 a24839 1 ‘show debug gnu-nat’ d24842 1 a24842 1 ‘set debug infrun’ d24844 1 a24844 1 inferior. The default is off. ‘infrun.c’ contains GDB's runtime d24847 2 a24848 1 ‘show debug infrun’ d24851 1 a24851 1 ‘set debug infcall’ d24854 2 a24855 1 ‘show debug infcall’ d24858 1 a24858 1 ‘set debug jit’ d24860 2 a24861 1 ‘show debug jit’ d24864 1 a24864 1 ‘set debug linux-nat [on|off]’ d24867 2 a24868 1 ‘show debug linux-nat’ d24871 1 a24871 1 ‘set debug linux-namespaces’ d24874 2 a24875 1 ‘show debug linux-namespaces’ d24878 1 a24878 1 ‘set debug mach-o’ a24880 3 ‘show debug mach-o’ Displays the current state of displaying debugging messages related to reading of COFF/PE exported symbols. d24882 5 a24886 1 ‘set debug notification’ d24889 2 a24890 1 ‘show debug notification’ d24894 1 a24894 1 ‘set debug observer’ d24897 2 a24898 1 ‘show debug observer’ d24901 2 a24902 2 ‘set debug overload’ Turns on or off display of GDB C++ overload debugging info. This a24904 3 ‘show debug overload’ Displays the current state of displaying GDB C++ overload debugging info. d24906 5 a24910 1 ‘set debug parser’ d24912 1 a24912 1 Internally, this sets the ‘yydebug’ variable in the expression d24915 2 a24916 1 ‘show debug parser’ d24919 1 a24919 1 ‘set debug remote’ d24922 3 a24924 2 printed on the GDB standard output stream. The default is off. ‘show debug remote’ d24927 1 a24927 1 ‘set debug remote-packet-max-chars’ d24929 1 a24929 1 packet when ‘set debug remote’ is on. This is useful to prevent d24933 1 a24933 1 The default value is ‘512’, which means GDB will truncate each d24936 4 a24939 3 Setting this option to ‘unlimited’ will disable truncation and will output the full length of the remote packets. ‘show debug remote-packet-max-chars’ d24942 1 a24942 1 ‘set debug separate-debug-file’ d24945 2 a24946 1 ‘show debug separate-debug-file’ d24949 2 a24950 2 ‘set debug serial’ Turns on or off display of GDB serial debugging info. The default d24952 2 a24953 1 ‘show debug serial’ d24956 1 a24956 1 ‘set debug solib’ d24959 2 a24960 1 ‘show debug solib’ d24963 1 a24963 1 ‘set debug symbol-lookup’ d24968 2 a24969 1 ‘show debug symbol-lookup’ d24972 1 a24972 1 ‘set debug symfile’ d24975 2 a24976 1 ‘show debug symfile’ d24979 1 a24979 1 ‘set debug symtab-create’ d24984 2 a24985 1 ‘show debug symtab-create’ d24988 2 a24989 2 ‘set debug target’ Turns on or off display of GDB target debugging info. This info d24991 1 a24991 1 happens. The default is 0. Set it to 1 to track events, and to 2 d24993 2 a24994 1 ‘show debug target’ d24997 1 a24997 1 ‘set debug timestamp’ d25001 2 a25002 1 ‘show debug timestamp’ d25006 2 a25007 2 ‘set debug varobj’ Turns on or off display of GDB variable object debugging info. The d25009 2 a25010 1 ‘show debug varobj’ d25014 1 a25014 1 ‘set debug xml’ d25016 2 a25017 1 ‘show debug xml’ d25020 1 a25020 1 ‘set debug breakpoints’ d25023 2 a25024 1 ‘show debug breakpoints’ d25034 9 a25042 8 ‘set interactive-mode’ If ‘on’, forces GDB to assume that GDB was started in a terminal. In practice, this means that GDB should wait for the user to answer queries generated by commands entered at the command prompt. If ‘off’, forces GDB to operate in the opposite mode, and it uses the default answers to all queries. If ‘auto’ (the default), GDB tries to determine whether its standard input is a terminal, and works in interactive-mode if it is, non-interactively otherwise. d25049 1 a25049 1 ‘show interactive-mode’ d25053 4 a25056 4 ‘set suppress-cli-notifications’ If ‘on’, command-line-interface (CLI) notifications that are printed by GDB are suppressed. If ‘off’, the notifications are printed as usual. The default value is ‘off’. CLI notifications d25060 1 a25060 1 _User-selected context changes:_ d25080 1 a25080 1 _The program being debugged stops:_ d25083 2 a25084 2 interrupt, etc.), GDB prints information about the stop event. For example, below is a breakpoint hit: d25107 1 a25107 1 ‘show suppress-cli-notifications’ d25130 1 a25130 1 ‘set script-extension off’ d25133 1 a25133 1 ‘set script-extension soft’ d25139 1 a25139 1 ‘set script-extension strict’ d25144 3 a25146 2 ‘show script-extension’ Display the current value of the ‘script-extension’ option. d25181 5 a25185 5 A “user-defined command” is a sequence of GDB commands to which you assign a new name as a command. This is done with the ‘define’ command. User commands may accept an unlimited number of arguments separated by whitespace. Arguments are accessed within the user command via ‘$arg0...$argN’. A trivial example: d25195 1 a25195 1 This defines the command ‘adder’, which prints the sum of its three d25200 1 a25200 1 In addition, ‘$argc’ may be used to find out how many arguments have d25212 1 a25212 1 Combining with the ‘eval’ command (*note eval::) makes it easier to d25225 1 a25225 1 ‘define COMMANDNAME’ d25228 5 a25232 5 it. The argument COMMANDNAME may be a bare command name consisting of letters, numbers, dashes, dots, and underscores. It may also start with any predefined or user-defined prefix command. For example, ‘define target my-target’ creates a user-defined ‘target my-target’ command. d25235 2 a25236 2 lines, which are given following the ‘define’ command. The end of these commands is marked by a line containing ‘end’. d25238 1 a25238 1 ‘document COMMANDNAME’ d25240 1 a25240 1 accessed by ‘help’. The command COMMANDNAME must already be d25242 2 a25243 2 ‘define’ reads the lines of the command definition, ending with ‘end’. After the ‘document’ command is finished, ‘help’ on command d25246 2 a25247 2 You may use the ‘document’ command again to change the documentation of a command. Redefining the command with ‘define’ d25251 1 a25251 1 documentation will then be used by the ‘help’ and ‘apropos’ d25254 2 a25255 2 defining an alias as a set of nested ‘with’ commands (*note Command aliases default args::). d25257 1 a25257 1 ‘define-prefix COMMANDNAME’ d25259 7 a25265 7 command. Once marked, COMMANDNAME can be used as prefix command by the ‘define’ command. Note that ‘define-prefix’ can be used with a not yet defined COMMANDNAME. In such a case, COMMANDNAME is defined as an empty user-defined command. In case you redefine a command that was marked as a user-defined prefix command, the subcommands of the redefined command are kept (and GDB indicates so to the user). d25293 1 a25293 1 ‘dont-repeat’ d25298 1 a25298 1 ‘help user-defined’ d25300 1 a25300 1 class COMMAND_USER. The first line of the documentation or d25303 2 a25304 2 ‘show user’ ‘show user COMMANDNAME’ d25310 3 a25312 3 ‘show max-user-call-depth’ ‘set max-user-call-depth’ The value of ‘max-user-call-depth’ controls how many recursion d25318 1 a25318 1 use control flow commands, described in *note Command Files::. d25335 3 a25337 3 You may define “hooks”, which are a special kind of user-defined command. Whenever you run the command ‘foo’, if the user-defined command ‘hook-foo’ exists, it is executed (with no arguments) before d25341 2 a25342 2 executed. Whenever you run the command ‘foo’, if the user-defined command ‘hookpost-foo’ exists, it is executed (with no arguments) after d25350 4 a25353 4 In addition, a pseudo-command, ‘stop’ exists. Defining (‘hook-stop’) makes the associated commands execute every time execution stops in your program: before breakpoint commands are run, displays are printed, or the stack frame is printed. d25355 1 a25355 1 For example, to ignore ‘SIGALRM’ signals while single-stepping, but d25370 1 a25370 1 As a further example, to hook at the beginning and end of the ‘echo’ d25386 6 a25391 6 You can define a hook for any single-word command in GDB, but not for command aliases; you should define a hook for the basic command name, e.g. ‘backtrace’ rather than ‘bt’. You can hook a multi-word command by adding ‘hook-’ or ‘hookpost-’ to the last word of the command, e.g. ‘define target hook-remote’ to add a hook to ‘target remote’. d25398 1 a25398 1 you get a warning from the ‘define’ command. d25407 1 a25407 1 commands. Comments (lines starting with ‘#’) may also be included. An d25411 2 a25412 2 You can request the execution of a command file with the ‘source’ command. Note that the ‘source’ command is also used to evaluate d25414 1 a25414 1 configured using the ‘script-extension’ setting. *Note Extending GDB: d25417 1 a25417 1 ‘source [-s] [-v] FILENAME’ d25427 4 a25430 4 file is not found there, and FILENAME does not specify a directory, then GDB also looks for the file on the source search path (specified with the ‘directory’ command); except that ‘$cdir’ is not searched because the compilation directory is not relevant to scripts. d25432 1 a25432 1 If ‘-s’ is specified, then GDB searches for FILENAME on the search d25434 10 a25443 10 appending FILENAME to each element of the search path. So, for example, if FILENAME is ‘mylib/myscript’ and the search path contains ‘/home/user’ then GDB will look for the script ‘/home/user/mylib/myscript’. The search is also done if FILENAME is an absolute path. For example, if FILENAME is ‘/tmp/myscript’ and the search path contains ‘/home/user’ then GDB will look for the script ‘/home/user/tmp/myscript’. For DOS-like systems, if FILENAME contains a drive specification, it is stripped before concatenation. For example, if FILENAME is ‘d:myscript’ and the search path contains ‘c:/tmp’ then GDB will look for the script ‘c:/tmp/myscript’. d25445 2 a25446 2 If ‘-v’, for verbose mode, is given then GDB displays each command as it is executed. The option must be given before FILENAME, and is d25462 3 a25464 3 (The syntax above will vary depending on the shell used.) This example will execute commands from the file ‘cmds’. All output and errors would be directed to ‘log’. d25471 3 a25473 2 these complexities. Using these commands, you can write complex scripts that loop over data structures, execute commands conditionally, etc. d25475 2 a25476 2 ‘if’ ‘else’ d25478 1 a25478 1 executed commands. The ‘if’ command takes a single argument, which d25481 1 a25481 1 value is nonzero). There can then optionally be an ‘else’ line, d25484 1 a25484 1 containing ‘end’. d25486 11 a25496 11 ‘while’ This command allows to write loops. Its syntax is similar to ‘if’: the command takes a single argument, which is an expression to evaluate, and must be followed by the commands to execute, one per line, terminated by an ‘end’. These commands are called the “body” of the loop. The commands in the body of ‘while’ are executed repeatedly as long as the expression evaluates to true. ‘loop_break’ This command exits the ‘while’ loop in whose body it is included. Execution of the script continues after that ‘while’s ‘end’ line. d25498 1 a25498 1 ‘loop_continue’ d25500 2 a25501 2 commands in the ‘while’ loop in whose body it is included. Execution branches to the beginning of the ‘while’ loop, where it d25504 3 a25506 3 ‘end’ Terminate the block of commands that are the body of ‘if’, ‘else’, or ‘while’ flow-control commands. d25520 4 a25523 4 ‘echo TEXT’ Print TEXT. Nonprinting characters can be included in TEXT using C escape sequences, such as ‘\n’ to print a newline. *No newline is printed unless you specify one.* In addition to the standard C d25527 2 a25528 2 otherwise trimmed from all arguments. To print ‘ and foo = ’, use the command ‘echo \ and foo = \ ’. d25543 1 a25543 1 ‘output EXPRESSION’ d25545 1 a25545 1 newlines, no ‘$NN = ’. The value is not entered in the value d25549 1 a25549 1 ‘output/FMT EXPRESSION’ d25551 1 a25551 1 formats as for ‘print’. *Note Output Formats: Output Formats, for d25554 1 a25554 1 ‘printf TEMPLATE, EXPRESSIONS...’ d25564 2 a25565 2 As in ‘C’ ‘printf’, ordinary characters in TEMPLATE are printed verbatim, while “conversion specification” introduced by the ‘%’ d25575 3 a25577 3 ‘printf’ supports all the standard ‘C’ conversion specifications, including the flags and modifiers between the ‘%’ character and the conversion letter, with the following exceptions: d25579 1 a25579 1 • The argument-ordering modifiers, such as ‘2$’, are not d25582 1 a25582 1 • The modifier ‘*’ is not supported for specifying precision or d25585 2 a25586 2 • The ‘'’ flag (for separation of digits into groups according to ‘LC_NUMERIC'’) is not supported. d25588 1 a25588 1 • The type modifiers ‘hh’, ‘j’, ‘t’, and ‘z’ are not supported. d25590 1 a25590 1 • The conversion letter ‘n’ (as in ‘%n’) is not supported. d25592 1 a25592 1 • The conversion letters ‘a’ and ‘A’ are not supported. d25594 4 a25597 4 Note that the ‘ll’ type modifier is supported only if the underlying ‘C’ implementation used to build GDB supports the ‘long long int’ type, and the ‘L’ type modifier is supported only if ‘long double’ type is available. d25599 2 a25600 2 As in ‘C’, ‘printf’ supports simple backslash-escape sequences, such as ‘\n’, ‘\t’, ‘\\’, ‘\"’, ‘\a’, and ‘\f’, that consist of d25604 2 a25605 2 Additionally, ‘printf’ supports conversion specifications for DFP (“Decimal Floating Point”) types using the following length d25608 1 a25608 1 • ‘H’ for printing ‘Decimal32’ types. d25610 1 a25610 1 • ‘D’ for printing ‘Decimal64’ types. d25612 1 a25612 1 • ‘DD’ for printing ‘Decimal128’ types. d25614 1 a25614 1 If the underlying ‘C’ implementation used to build GDB has support d25618 1 a25618 1 In case there is no such ‘C’ support, no additional modifiers will d25625 3 a25627 3 Additionally, ‘printf’ supports a special ‘%V’ output format. This format prints the string representation of an expression just as GDB would produce with the standard ‘print’ command (*note d25635 2 a25636 2 It is possible to include print options with the ‘%V’ format by placing them in ‘[...]’ immediately after the ‘%V’, like this: d25641 2 a25642 2 If you need to print a literal ‘[’ directly after a ‘%V’, then just include an empty print options list: d25647 1 a25647 1 ‘eval TEMPLATE, EXPRESSIONS...’ d25651 1 d25658 1 a25658 1 When a new object file is read (for example, due to the ‘file’ command, d25660 1 a25660 1 the command file ‘OBJFILE-gdb.gdb’. *Note Auto-loading extensions::. d25665 1 a25665 1 ‘set auto-load gdb-scripts [on|off]’ d25669 1 a25669 1 ‘show auto-load gdb-scripts’ d25673 3 a25675 3 ‘info auto-load gdb-scripts [REGEXP]’ Print the list of all canned sequences of commands scripts that GDB auto-loaded. d25687 2 a25688 2 For example, if a new GDB command defined in Python (*note Python::) has a long name, it is handy to have an abbreviated version of it that d25691 1 a25691 1 GDB itself uses aliases. For example ‘s’ is an alias of the ‘step’ d25693 1 a25693 1 commands like ‘set’ and ‘show’. d25695 3 a25697 3 Aliases are also used to provide shortened or more common versions of multi-word commands. For example, GDB provides the ‘tty’ alias of the ‘set inferior-tty’ command. d25699 1 a25699 1 You can define a new alias with the ‘alias’ command. d25701 1 a25701 1 ‘alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS]’ d25712 1 a25712 1 The ‘-a’ option specifies that the new alias is an abbreviation of d25715 1 a25715 1 The ‘--’ option specifies the end of options, and is useful when d25718 3 a25720 3 You can specify DEFAULT-ARGS for your alias. These DEFAULT-ARGS will be automatically added before the alias arguments typed explicitly on the command line. d25722 1 a25722 1 For example, the below defines an alias ‘btfullall’ that shows all d25726 2 a25727 2 For more information about DEFAULT-ARGS, see *note Default Arguments: Command aliases default args. d25730 4 a25733 4 command so that there is less to type. Suppose you were tired of typing ‘disas’, the current shortest unambiguous abbreviation of the ‘disassemble’ command and you wanted an even shorter version named ‘di’. The following will accomplish this. d25739 1 a25739 1 the ‘document’ command. An alias automatically picks up the d25742 3 a25744 3 Here is an example where we make ‘elms’ an abbreviation of ‘elements’ in the ‘set print elements’ command. This is to show that you can make an abbreviation of any part of a command. d25752 2 a25753 2 Note that if you are defining an alias of a ‘set’ command, and you want to have an alias for the corresponding ‘show’ command, then you d25762 2 a25763 2 for a more complex command. This creates alias ‘spe’ of the command ‘set print elements’. d25778 2 a25779 2 You can tell GDB to always prepend some default arguments to the list of arguments provided explicitly by the user when using a user-defined d25787 1 a25787 1 For example, if you often use the command ‘thread apply all’ d25790 1 a25790 1 the ‘-ascending’ and ‘-c’ options by using: d25795 2 a25796 2 type the ‘thread apply asc-all’ followed by ‘some arguments’, GDB will execute ‘thread apply all -ascending -c some arguments’. d25805 2 a25806 2 For example, you define a new alias ‘bt_ALL’ showing all possible information and another alias ‘bt_SMALL’ showing very limited d25813 1 a25813 1 (For more on using the ‘alias’ command, see *note Aliases::.) d25817 1 a25817 1 as argument. For example, the below defines ‘faalocalsoftype’ that d25827 2 a25828 2 ‘with’ commands to have a particular combination of temporary settings. For example, the below defines the alias ‘pp10’ that pretty prints an d25832 7 a25838 7 This defines the alias ‘pp10’ as being a sequence of 3 commands. The first part ‘with print pretty --’ temporarily activates the setting ‘set print pretty’, then launches the command that follows the separator ‘--’. The command following the first part is also a ‘with’ command that temporarily changes the setting ‘set print elements’ to 10, then launches the command that follows the second separator ‘--’. The third part ‘print’ is the command the ‘pp10’ alias will launch, using the d25840 2 a25841 2 the user. For more information about the ‘with’ command usage, see *note Command Settings::. d25844 1 a25844 1 the aliased command. When the alias is a set of nested commands, ‘help’ d25846 3 a25848 3 not particularly useful for an alias such as ‘pp10’. For such an alias, it is useful to give a specific documentation using the ‘document’ command (*note document: Define.). d25864 1 a25864 1 configured using ‘--with-python’. d25867 1 a25867 1 ‘DATA-DIRECTORY/python’, where DATA-DIRECTORY is the data directory as d25869 1 a25869 1 as the “python directory”, is automatically added to the Python Search d25875 2 a25876 2 ‘DATA-DIRECTORY/python/gdb/command’ or ‘DATA-DIRECTORY/python/gdb/function’ directories are automatically d25895 3 a25897 3 ‘python-interactive [COMMAND]’ ‘pi [COMMAND]’ Without an argument, the ‘python-interactive’ command can be used d25899 1 a25899 1 ‘EOF’ character (e.g., ‘Ctrl-D’ on an empty prompt). d25909 3 a25911 3 ‘python [COMMAND]’ ‘py [COMMAND]’ The ‘python’ command can be used to evaluate Python code. d25913 1 a25913 1 If given an argument, the ‘python’ command will evaluate the d25919 5 a25923 5 If you do not provide an argument to ‘python’, it will act as a multi-line command, like ‘define’. In this case, the Python script is made up of subsequent command lines, given after the ‘python’ command. This command list is terminated using a line containing ‘end’. For example: d25930 1 a25930 1 ‘set python print-stack’ d25933 3 a25935 3 controlled using ‘set python print-stack’: if ‘full’, then full Python stack printing is enabled; if ‘none’, then Python stack and message printing is disabled; if ‘message’, the default, only the d25938 2 a25939 2 ‘set python ignore-environment [on|off]’ By default this option is ‘off’, and, when GDB initializes its d25942 1 a25942 1 example ‘PYTHONHOME’, and ‘PYTHONPATH’(1). d25944 1 a25944 1 If this option is set to ‘on’ before Python is initialized then d25950 1 a25950 1 This option is equivalent to passing ‘-E’ to the real ‘python’ d25953 2 a25954 2 ‘set python dont-write-bytecode [auto|on|off]’ When this option is ‘off’, then, once GDB has initialized the d25956 1 a25956 1 modules that it imports and write the byte code to disk in ‘.pyc’ d25959 1 a25959 1 If this option is set to ‘on’ before Python is initialized then d25965 4 a25968 4 By default this option is set to ‘auto’. In this mode, provided the ‘python ignore-environment’ setting is ‘off’, the environment variable ‘PYTHONDONTWRITEBYTECODE’ is examined to see if it should write out byte-code or not. ‘PYTHONDONTWRITEBYTECODE’ is d25974 1 a25974 1 This option is equivalent to passing ‘-B’ to the real ‘python’ d25980 5 a25984 4 ‘source script-name’ The script name must end with ‘.py’ and GDB must be configured to recognize the script language based on filename extension using the ‘script-extension’ setting. *Note Extending GDB: Extending GDB. d25988 9 a25996 9 ‘set debug py-breakpoint on|off’ ‘show debug py-breakpoint’ When ‘on’, GDB prints debug messages related to the Python breakpoint API. This is ‘off’ by default. ‘set debug py-unwind on|off’ ‘show debug py-unwind’ When ‘on’, GDB prints debug messages related to the Python unwinder API. This is ‘off’ by default. d26000 1 a26000 1 (1) See the ENVIRONMENT VARIABLES section of ‘man 1 python’ for a d26010 1 a26010 1 command ‘python help (gdb)’. d26015 1 a26015 1 ‘gdb.some_function ('foo', bar = 1, baz = 2)’. d26068 5 a26072 5 At startup, GDB overrides Python's ‘sys.stdout’ and ‘sys.stderr’ to print using GDB's output-paging streams. A Python program which outputs to one of these streams may have its output interrupted by the user (*note Screen Size::). In this situation, a Python ‘KeyboardInterrupt’ exception is thrown. d26077 8 a26084 8 • GDB installs handlers for ‘SIGCHLD’ and ‘SIGINT’. Python code must not override these, or even change the options using ‘sigaction’. If your program changes the handling of these signals, GDB will most likely stop working correctly. Note that it is unfortunately common for GUI toolkits to install a ‘SIGCHLD’ handler. When creating a new Python thread, you can use ‘gdb.block_signals’ or ‘gdb.Thread’ to handle this correctly; see *note Threading in GDB::. d26086 1 a26086 1 • GDB takes care to mark its internal file descriptors as d26093 1 a26093 1 GDB introduces a new Python module, named ‘gdb’. All methods and d26095 2 a26096 2 ‘import’s the ‘gdb’ module for use in all scripts evaluated by the ‘python’ command. d26098 2 a26099 2 Some types of the ‘gdb’ module come with a textual representation (accessible through the ‘repr’ or ‘str’ functions). These are offered d26107 2 a26108 2 exception happens while COMMAND runs, it is translated as described in *note Exception Handling: Exception Handling. d26113 1 a26113 1 defaults to ‘False’. d26117 6 a26122 6 If the TO_STRING parameter is ‘True’, then output will be collected by ‘gdb.execute’ and returned as a string. The default is ‘False’, in which case the return value is ‘None’. If TO_STRING is ‘True’, the GDB virtual terminal will be temporarily set to unlimited width and height, and its pagination will be disabled; *note Screen Size::. d26126 2 a26127 2 Breakpoints In Python::, for more information. In GDB version 7.11 and earlier, this function returned ‘None’ if there were no d26129 1 a26129 1 ‘gdb.breakpoints’ returns an empty sequence in this case. d26133 2 a26134 2 ‘gdb.Breakpoint’ objects matching function names defined by the REGEX pattern. If the MINSYMS keyword is ‘True’, all system d26138 4 a26141 4 matched by the REGEX pattern. If the number of matches exceeds the integer value of THROTTLE, a ‘RuntimeError’ will be raised and no breakpoints will be created. If THROTTLE is not defined then there is no imposed limit on the maximum number of matches and d26143 1 a26143 1 iterable that yields a collection of ‘gdb.Symtab’ objects and will d26145 1 a26145 1 ‘gdb.Symtab’ objects. d26150 1 a26150 1 multi-part name. For example, ‘print object’ is a valid parameter d26154 1 a26154 1 ‘gdb.error’ (*note Exception Handling::). Otherwise, the d26159 3 a26161 3 Sets the gdb parameter NAME to VALUE. As with ‘gdb.parameter’, the parameter name string may contain spaces if the parameter has a multi-part name. d26164 1 a26164 1 Create a Python context manager (for use with the Python ‘with’ d26168 1 a26168 1 This uses ‘gdb.parameter’ in its implementation, so it can throw d26180 6 a26185 6 NUMBER is negative, then GDB will take its absolute value and count backward from the last element (i.e., the most recent element) to find the value to return. If NUMBER is zero, then GDB will return the most recent element. If the element specified by NUMBER doesn't exist in the value history, a ‘gdb.error’ exception will be raised. d26188 1 a26188 1 of ‘gdb.Value’ (*note Values From Inferior::). d26191 1 a26191 1 Takes VALUE, an instance of ‘gdb.Value’ (*note Values From d26194 8 a26201 7 history number. If VALUE is not a ‘gdb.Value’, it is is converted using the ‘gdb.Value’ constructor. If VALUE can't be converted to a ‘gdb.Value’ then a ‘TypeError’ is raised. When a command implemented in Python prints a single ‘gdb.Value’ as its result, then placing the value into the history will allow the user convenient access to those values via CLI history facilities. d26210 1 a26210 1 include the ‘$’ that is used to mark a convenience variable in an d26212 1 a26212 1 ‘None’ is returned. d26217 4 a26220 4 include the ‘$’ that is used to mark a convenience variable in an expression. If VALUE is ‘None’, then the convenience variable is removed. Otherwise, if VALUE is not a ‘gdb.Value’ (*note Values From Inferior::), it is is converted using the ‘gdb.Value’ d26226 1 a26226 1 ‘gdb.Value’. d26230 1 a26230 1 ‘False’, meaning that the current frame or current static context d26234 3 a26236 3 CLI Commands In Python::, *note GDB/MI Commands In Python::), as it provides a way to parse the command's argument as an expression. It is also useful simply to compute values. d26239 6 a26244 6 Return the ‘gdb.Symtab_and_line’ object corresponding to the PC value. *Note Symbol Tables In Python::. If an invalid value of PC is passed as an argument, then the ‘symtab’ and ‘line’ attributes of the returned ‘gdb.Symtab_and_line’ object will be ‘None’ and 0 respectively. This is identical to ‘gdb.current_progspace().find_pc_line(pc)’ and is included for d26252 1 a26252 1 ‘gdb.STDOUT’ d26255 1 a26255 1 ‘gdb.STDERR’ d26258 1 a26258 1 ‘gdb.STDLOG’ d26261 1 a26261 1 Writing to ‘sys.stdout’ or ‘sys.stderr’ will automatically call d26266 6 a26271 5 Flush the buffer of a GDB paginated stream so that the contents are displayed immediately. GDB will flush the contents of a stream automatically when it encounters a newline in the buffer. The optional STREAM determines the stream to flush. The default stream is GDB's standard output stream. Possible stream values are: d26273 1 a26273 1 ‘gdb.STDOUT’ d26276 1 a26276 1 ‘gdb.STDERR’ d26279 1 a26279 1 ‘gdb.STDLOG’ d26282 2 a26283 1 Flushing ‘sys.stdout’ or ‘sys.stderr’ will automatically call this d26289 1 a26289 1 ‘gdb.parameter('target-charset')’ in that ‘auto’ is never returned. d26294 1 a26294 1 ‘gdb.parameter('target-wide-charset')’ in that ‘auto’ is never d26300 1 a26300 1 ‘gdb.parameter('host-charset')’ in that ‘auto’ is never returned. d26304 2 a26305 2 a string, or ‘None’. This is identical to ‘gdb.current_progspace().solib_name(address)’ and is included for d26311 8 a26318 8 Python tuple containing two elements. The first element contains a string holding any unparsed section of EXPRESSION (or ‘None’ if the expression has been fully parsed). The second element contains either ‘None’ or another tuple that contains all the locations that match the expression represented as ‘gdb.Symtab_and_line’ objects (*note Symbol Tables In Python::). If EXPRESSION is provided, it is decoded the way that GDB's inbuilt ‘break’ or ‘edit’ commands do (*note Location Specifications::). a26320 1 d26324 4 a26327 4 The parameter ‘current_prompt’ contains the current GDB prompt. This method must return a Python string, or ‘None’. If a string is returned, the GDB prompt will be set to that string. If ‘None’ is returned, GDB will continue to use the current prompt. d26330 2 a26331 2 as those used by readline for command input, and annotation related prompts are prohibited from being changed. d26335 3 a26337 3 current build of GDB supports. Each architecture name is a string. The names returned in this list are the same names as are returned from ‘gdb.Architecture.name’ (*note Architecture.name: d26341 1 a26341 1 Return a list of ‘gdb.TargetConnection’ objects, one for each d26346 2 a26347 2 Return a string in the format ‘ADDR ’, where ADDR is ADDRESS formatted in hexadecimal, SYMBOL is the symbol whose d26354 2 a26355 2 GDB looks back for a suitable symbol can be controlled with ‘set print max-symbolic-offset’ (*note Print Settings::). d26358 3 a26360 3 number information when ‘set print symbol-filename on’ (*note Print Settings::), in this case the format of the returned string is ‘ADDR at FILENAME:LINE-NUMBER’. d26376 2 a26377 2 either they must both be provided, or neither must be provided (and the defaults will be used). d26381 1 a26381 1 ‘disassemble’. d26391 4 a26394 4 ‘gdb.parameter('language')’, this function will never return ‘auto’. If a ‘gdb.Frame’ object is available (*note Frames In Python::), the ‘language’ method might be preferable in some cases, as that is not affected by the user's language setting. d26408 1 a26408 1 be delivered to the GDB main thread. The ‘block_signals’ function d26417 2 a26418 2 This is a subclass of Python's ‘threading.Thread’ class. It overrides the ‘start’ method to call ‘block_signals’, making this d26424 4 a26427 3 character at the terminal. That is, if the inferior is running, it is interrupted; if a GDB command is executing, it is stopped; and if a Python command is running, ‘KeyboardInterrupt’ will be raised. d26429 1 a26429 1 Unlike most Python APIs in GDB, ‘interrupt’ is thread-safe. d26435 1 a26435 1 ‘post_event’ will be run in the order in which they were posted; d26439 1 a26439 1 Unlike most Python APIs in GDB, ‘post_event’ is thread-safe. For d26470 1 a26470 1 When executing the ‘python’ command, Python exceptions uncaught within d26472 1 a26472 1 mechanism. If the command that called ‘python’ does not handle the d26474 1 a26474 1 will be printed depends on ‘set python print-stack’ (*note Python d26486 3 a26488 3 ‘gdb.error’ This is the base class for most exceptions generated by GDB. It is derived from ‘RuntimeError’, for compatibility with earlier d26494 7 a26500 7 ‘gdb.MemoryError’ This is a subclass of ‘gdb.error’ which is thrown when an operation tried to access invalid memory in the inferior. ‘KeyboardInterrupt’ User interrupt (via ‘C-c’ or by typing ‘q’ at a pagination prompt) is translated to a Python ‘KeyboardInterrupt’ exception. d26503 2 a26504 2 as its value and the Python call stack backtrace at the Python statement closest to where the GDB error occurred as the traceback. d26506 2 a26507 2 When implementing GDB commands in Python via ‘gdb.Command’, or functions via ‘gdb.Function’, it is useful to be able to throw an d26512 1 a26512 1 ‘gdb.GdbError’ d26539 3 a26541 3 GDB provides values it obtains from the inferior program in an object of type ‘gdb.Value’. GDB uses this object for its internal bookkeeping of the inferior's values, and for fetching values when necessary. d26545 1 a26545 1 example for an integer or floating-point value ‘some_val’: d26549 8 a26556 8 As result of this, ‘bar’ will also be a ‘gdb.Value’ object whose values are of the same type as those of ‘some_val’. Valid Python operations can also be performed on ‘gdb.Value’ objects representing a ‘struct’ or ‘class’ object. For such cases, the overloaded operator (if present), is used to perform the operation. For example, if ‘val1’ and ‘val2’ are ‘gdb.Value’ objects representing instances of a ‘class’ which overloads the ‘+’ operator, then one can use the ‘+’ operator in their Python script as follows: d26560 2 a26561 2 The result of the operation ‘val3’ is also a ‘gdb.Value’ object corresponding to the value returned by the overloaded ‘+’ operator. In d26563 2 a26564 2 ‘+’ (binary addition), ‘-’ (binary subtraction), ‘*’ (multiplication), ‘/’, ‘%’, ‘<<’, ‘>>’, ‘|’, ‘&’, ‘^’. d26566 4 a26569 4 Inferior values that are structures or instances of some class can be accessed using the Python “dictionary syntax”. For example, if ‘some_val’ is a ‘gdb.Value’ instance holding a structure, you can access its ‘foo’ element with: d26573 6 a26578 6 Again, ‘bar’ will also be a ‘gdb.Value’ object. Structure elements can also be accessed by using ‘gdb.Field’ objects as subscripts (*note Types In Python::, for more information on ‘gdb.Field’ objects). For example, if ‘foo_field’ is a ‘gdb.Field’ object corresponding to element ‘foo’ of the above structure, then ‘bar’ can also be accessed as follows: d26582 1 a26582 1 If a ‘gdb.Value’ has array or pointer type, an integer index can be d26587 4 a26590 4 A ‘gdb.Value’ that represents a function can be executed via inferior function call. Any arguments provided to the call must match the function's prototype, and must be provided in the order specified by that prototype. d26592 1 a26592 1 For example, ‘some_val’ is a ‘gdb.Value’ instance representing a d26599 1 a26599 1 ‘gdb.Value’. d26605 2 a26606 2 ‘gdb.Value’ object representing the address. Otherwise, this attribute holds ‘None’. d26614 2 a26615 2 The type of this ‘gdb.Value’. The value of this attribute is a ‘gdb.Type’ object (*note Types In Python::). d26618 1 a26618 1 The dynamic type of this ‘gdb.Value’. This uses the object's d26620 7 a26626 6 determine the dynamic type of the value. If this value is of class type, it will return the class in which the value is embedded, if any. If this value is of pointer or reference to a class type, it will compute the dynamic type of the referenced object, and return a pointer or reference to that type, respectively. In all other cases, it will return the value's static type. d26630 1 a26630 1 just return the static type of the value as in ‘ptype foo’ (*note d26634 2 a26635 2 The value of this read-only boolean attribute is ‘True’ if this ‘gdb.Value’ has not yet been fetched from the inferior. GDB does d26640 2 a26641 2 The value of ‘somevar’ is not fetched at this time. It will be fetched when the value is needed, or when the ‘fetch_lazy’ method d26645 2 a26646 2 The value of this attribute is a ‘bytes’ object containing the bytes that make up this ‘Value’'s complete value in little endian d26651 3 a26653 3 buffer object (e.g. a ‘bytes’ object), the length of the new buffer must exactly match the length of this ‘Value’'s type. The bytes values in the new buffer should be in little endian order. d26655 2 a26656 2 As with ‘Value.assign’ (*note Value.assign::), if this value cannot be assigned to, then an exception will be thrown. d26661 1 a26661 1 Many Python values can be converted directly to a ‘gdb.Value’ via d26664 1 a26664 1 Python boolean d26668 2 a26669 2 Python integer A Python integer is converted to the C ‘long’ type for the d26672 2 a26673 2 Python long A Python long is converted to the C ‘long long’ type for the d26676 2 a26677 2 Python float A Python float is converted to the C ‘double’ type for the d26680 4 a26683 4 Python string A Python string is converted to a target string in the current target language using the current target encoding. If a character cannot be represented in the current target d26686 2 a26687 2 ‘gdb.Value’ If ‘val’ is a ‘gdb.Value’, then a copy of the value is made. d26689 3 a26691 3 ‘gdb.LazyString’ If ‘val’ is a ‘gdb.LazyString’ (*note Lazy Strings In Python::), then the lazy string's ‘value’ method is called, d26695 2 a26696 2 This second form of the ‘gdb.Value’ constructor returns a ‘gdb.Value’ of type TYPE where the value contents are taken from d26701 2 a26702 2 If TYPE is ‘None’ then this version of ‘__init__’ behaves as though TYPE was not passed at all. d26705 1 a26705 1 Assign RHS to this value, and return ‘None’. If this value cannot d26710 1 a26710 1 Return a new instance of ‘gdb.Value’ that is the result of casting d26712 1 a26712 1 ‘gdb.Type’ object. If the cast cannot be performed for some d26716 4 a26719 4 For pointer data types, this method returns a new ‘gdb.Value’ object whose contents is the object pointed to by the pointer. For example, if ‘foo’ is a C pointer to an ‘int’, declared in your C program as d26723 2 a26724 2 then you can use the corresponding ‘gdb.Value’ to access what ‘foo’ points to like this: d26728 2 a26729 2 The result ‘bar’ will be a ‘gdb.Value’ object holding the value pointed to by ‘foo’. d26731 2 a26732 2 A similar function ‘Value.referenced_value’ exists which also returns ‘gdb.Value’ objects corresponding to the values pointed to d26734 5 a26738 5 values). However, the behavior of ‘Value.dereference’ differs from ‘Value.referenced_value’ by the fact that the behavior of ‘Value.dereference’ is identical to applying the C unary operator ‘*’ on a given value. For example, consider a reference to a pointer ‘ptrref’, declared in your C++ program as d26746 6 a26751 6 Though ‘ptrref’ is a reference value, one can apply the method ‘Value.dereference’ to the ‘gdb.Value’ object corresponding to it and obtain a ‘gdb.Value’ which is identical to that corresponding to ‘val’. However, if you apply the method ‘Value.referenced_value’, the result would be a ‘gdb.Value’ object identical to that corresponding to ‘ptr’. d26757 10 a26766 10 The ‘gdb.Value’ object ‘py_val’ is identical to that corresponding to ‘val’, and ‘py_ptr’ is identical to that corresponding to ‘ptr’. In general, ‘Value.dereference’ can be applied whenever the C unary operator ‘*’ can be applied to the corresponding C value. For those cases where applying both ‘Value.dereference’ and ‘Value.referenced_value’ is allowed, the results obtained need not be identical (as we have seen in the above example). The results are however identical when applied on ‘gdb.Value’ objects corresponding to pointers (‘gdb.Value’ objects with type code ‘TYPE_CODE_PTR’) in a C/C++ program. d26770 1 a26770 1 ‘gdb.Value’ object corresponding to the value referenced by the d26772 1 a26772 1 ‘Value.dereference’ and ‘Value.referenced_value’ produce identical d26774 3 a26776 3 ‘Value.dereference’ cannot get the values referenced by reference values. For example, consider a reference to an ‘int’, declared in your C++ program as d26781 4 a26784 4 then applying ‘Value.dereference’ to the ‘gdb.Value’ object corresponding to ‘ref’ will result in an error, while applying ‘Value.referenced_value’ will result in a ‘gdb.Value’ object identical to that corresponding to ‘val’. d26790 2 a26791 2 The ‘gdb.Value’ object ‘py_val’ is identical to that corresponding to ‘val’. d26794 1 a26794 1 Return a ‘gdb.Value’ object which is a reference to the value d26798 2 a26799 2 Return a ‘gdb.Value’ object which is a ‘const’ version of the value encapsulated by this instance. d26802 1 a26802 1 Like ‘Value.cast’, but works as if the C++ ‘dynamic_cast’ operator d26806 1 a26806 1 Like ‘Value.cast’, but works as if the C++ ‘reinterpret_cast’ d26810 1 a26810 1 Convert a ‘gdb.Value’ to a string, similarly to what the ‘print’ d26812 1 a26812 1 calling the ‘str’ function on the ‘gdb.Value’. The representation d26820 3 a26822 3 ‘raw’ ‘True’ if pretty-printers (*note Pretty Printing::) should not be used to format the value. ‘False’ if enabled d26824 1 a26824 22 ‘gdb.Value’ should be used to format it. ‘pretty_arrays’ ‘True’ if arrays should be pretty printed to be more convenient to read, ‘False’ if they shouldn't (see ‘set print array’ in *note Print Settings::). ‘pretty_structs’ ‘True’ if structs should be pretty printed to be more convenient to read, ‘False’ if they shouldn't (see ‘set print pretty’ in *note Print Settings::). ‘array_indexes’ ‘True’ if array indexes should be included in the string representation of arrays, ‘False’ if they shouldn't (see ‘set print array-indexes’ in *note Print Settings::). ‘symbols’ ‘True’ if the string representation of a pointer should include the corresponding symbol name (if one exists), ‘False’ if it shouldn't (see ‘set print symbol’ in *note Print Settings::). d26826 34 a26859 13 ‘unions’ ‘True’ if unions which are contained in other structures or unions should be expanded, ‘False’ if they shouldn't (see ‘set print union’ in *note Print Settings::). ‘address’ ‘True’ if the string representation of a pointer should include the address, ‘False’ if it shouldn't (see ‘set print address’ in *note Print Settings::). ‘nibbles’ ‘True’ if binary values should be displayed in groups of four bits, known as nibbles. ‘False’ if it shouldn't (*note set d26862 6 a26867 6 ‘deref_refs’ ‘True’ if C++ references should be resolved to the value they refer to, ‘False’ (the default) if they shouldn't. Note that, unlike for the ‘print’ command, references are not automatically expanded when using the ‘format_string’ method or the ‘str’ function. There is no global ‘print’ setting to d26870 16 a26885 16 ‘actual_objects’ ‘True’ if the representation of a pointer to an object should identify the _actual_ (derived) type of the object rather than the _declared_ type, using the virtual function table. ‘False’ if the _declared_ type should be used. (See ‘set print object’ in *note Print Settings::). ‘static_members’ ‘True’ if static members should be included in the string representation of a C++ object, ‘False’ if they shouldn't (see ‘set print static-members’ in *note Print Settings::). ‘max_characters’ Number of string characters to print, ‘0’ to follow ‘max_elements’, or ‘UINT_MAX’ to print an unlimited number of characters (see ‘set print characters’ in *note Print d26888 4 a26891 4 ‘max_elements’ Number of array elements to print, or ‘0’ to print an unlimited number of elements (see ‘set print elements’ in *note Print Settings::). d26893 1 a26893 1 ‘max_depth’ d26895 2 a26896 2 ‘-1’ to print an unlimited number of elements (see ‘set print max-depth’ in *note Print Settings::). d26898 1 a26898 1 ‘repeat_threshold’ d26900 2 a26901 2 elements, or ‘0’ to represent all elements, even if repeated. (See ‘set print repeats’ in *note Print Settings::). d26903 4 a26906 4 ‘format’ A string containing a single character representing the format to use for the returned string. For instance, ‘'x'’ is equivalent to using the GDB command ‘print’ with the ‘/x’ d26909 2 a26910 2 ‘styling’ ‘True’ if GDB should apply styling to the returned string. d26913 1 a26913 1 included if styling is turned on, see *note Output Styling::. d26917 1 a26917 1 When ‘False’, which is the default, no output styling is d26920 2 a26921 2 ‘summary’ ‘True’ when just a summary should be printed. In this mode, d26924 1 a26924 1 by ‘set print frame-arguments scalars’ (*note Print d26934 3 a26936 3 If this ‘gdb.Value’ represents a string, then this method converts the contents to a Python string. Otherwise, this method will throw an exception. d26946 2 a26947 2 pointer to or an array of characters or ints of type ‘wchar_t’, ‘char16_t’, or ‘char32_t’. d26950 8 a26957 8 naming the encoding of the string in the ‘gdb.Value’, such as ‘"ascii"’, ‘"iso-8859-6"’ or ‘"utf-8"’. It accepts the same encodings as the corresponding argument to Python's ‘string.decode’ method, and the Python codec machinery will be used to convert the string. If ENCODING is not given, or if ENCODING is the empty string, then either the ‘target-charset’ (*note Character Sets::) will be used, or a language-specific encoding will be used, if the current language is able to supply one. d26960 1 a26960 1 argument to Python's ‘string.decode’ method. d26966 2 a26967 2 If this ‘gdb.Value’ represents a string, then this method converts the contents to a ‘gdb.LazyString’ (*note Lazy Strings In d26971 2 a26972 2 naming the encoding of the ‘gdb.LazyString’. Some examples are: ‘ascii’, ‘iso-8859-6’ or ‘utf-8’. If the ENCODING argument is an d26979 1 a26979 1 type. For further information on encoding in GDB please see *note d26988 3 a26990 3 If the ‘gdb.Value’ object is currently a lazy value (‘gdb.Value.is_lazy’ is ‘True’), then the value is fetched from the inferior. Any errors that occur in the process will produce a d26993 1 a26993 1 If the ‘gdb.Value’ object is not a lazy value, this method has no d27004 1 a27004 1 GDB represents types from the inferior using the class ‘gdb.Type’. d27006 1 a27006 1 The following type-related functions are available in the ‘gdb’ d27015 1 a27015 1 Ordinarily, this function will return an instance of ‘gdb.Type’. d27019 1 a27019 1 Architectures In Python::, for the ‘integer_type’ method. d27022 3 a27024 3 of that type can be accessed using the Python “dictionary syntax”. For example, if ‘some_type’ is a ‘gdb.Type’ instance holding a structure type, you can access its ‘foo’ field with: d27028 2 a27029 2 ‘bar’ will be a ‘gdb.Field’ object; see below under the description of the ‘Type.fields’ method for a description of the ‘gdb.Field’ class. d27031 1 a27031 1 An instance of ‘Type’ has the following attributes: d27041 1 a27041 1 ‘TYPE_CODE_’ constants defined below. d27045 1 a27045 1 situations, such as Rust ‘enum’ types or Ada variant records, the d27048 1 a27048 1 ‘gdb.lookup_type’ may be dynamic; while the type of the variable's d27057 2 a27058 2 ‘gdb.lookup_symbol("array", ...).type’ could yield a ‘gdb.Type’ which reports a size of ‘None’. This is the dynamic type. d27060 2 a27061 2 However, examining ‘gdb.parse_and_eval("array").type’ would yield a concrete type, whose length would be known. d27064 1 a27064 1 The name of this type. If this type has no name, then ‘None’ is d27068 5 a27072 5 The size of this type, in target ‘char’ units. Usually, a target's ‘char’ type will be an 8-bit byte. However, on some unusual platforms, this type may have a different size. A dynamic type may not have a fixed size; in this case, this attribute's value will be ‘None’. d27076 2 a27077 2 ‘struct’, ‘union’, or ‘enum’ in C and C++; not all languages have this concept. If this type has no tag name, then ‘None’ is d27081 2 a27082 2 The ‘gdb.Objfile’ that this type was defined in, or ‘None’ if there is no associated objfile. d27085 2 a27086 2 This property is ‘True’ if the type is a scalar type, otherwise, this property is ‘False’. Examples of non-scalar types include d27090 3 a27092 3 For scalar types (those for which ‘Type.is_scalar’ is ‘True’), this property is ‘True’ if the type is signed, otherwise this property is ‘False’. d27095 1 a27095 1 which ‘Type.is_scalar’ is ‘False’), will raise a ‘ValueError’. d27103 2 a27104 2 these types. This determination is done based on the language from which the type originated. d27108 1 a27108 1 ‘Type.is_array_like’, this is determined based on the originating a27113 1 d27117 1 a27117 1 • For structure and union types, this method returns the fields. d27119 1 a27119 1 • Enum types have one field per enum constant. d27121 1 a27121 1 • Function and method types have one field per parameter. The d27124 1 a27124 1 • Array types have one field representing the array's range. d27126 2 a27127 2 • If the type does not fit into one of these categories, a ‘TypeError’ is raised. d27129 2 a27130 1 Each field is a ‘gdb.Field’ object, with some pre-defined d27132 2 a27133 2 ‘bitpos’ This attribute is not available for ‘enum’ or ‘static’ (as in d27136 4 a27139 4 dynamic type, the position of a field may not be constant. In this case, the value will be ‘None’. Also, a dynamic type may have fields that do not appear in a corresponding concrete type. d27141 2 a27142 2 ‘enumval’ This attribute is only available for ‘enum’ fields, and its d27145 2 a27146 2 ‘name’ The name of the field, or ‘None’ for anonymous fields. d27148 2 a27149 2 ‘artificial’ This is ‘True’ if the field is artificial, usually meaning d27151 1 a27151 1 attribute is always provided, and is ‘False’ if the field is d27154 3 a27156 3 ‘is_base_class’ This is ‘True’ if the field represents a base class of a C++ structure. This attribute is always provided, and is ‘False’ d27158 1 a27158 1 argument of ‘fields’, or if that type was not a C++ class. d27160 1 a27160 1 ‘bitsize’ d27163 2 a27164 2 Otherwise, this will be zero; in this case the field's size is given by its type. d27166 3 a27168 3 ‘type’ The type of the field. This is usually an instance of ‘Type’, but it can be ‘None’ in some situations. d27170 1 a27170 1 ‘parent_type’ d27172 1 a27172 1 ‘gdb.Type’. d27175 1 a27175 1 Return a new ‘gdb.Type’ object which represents an array of this d27183 1 a27183 1 Return a new ‘gdb.Type’ object which represents a vector of this d27185 4 a27188 4 the vector; in this case the lower bound is zero. If two arguments are given, the first argument is the lower bound of the vector, and the second argument is the upper bound of the vector. A vector's length must not be negative, but the bounds can be. d27190 1 a27190 1 The difference between an ‘array’ and a ‘vector’ is that arrays d27196 2 a27197 2 Return a new ‘gdb.Type’ object which represents a ‘const’-qualified variant of this type. d27200 2 a27201 2 Return a new ‘gdb.Type’ object which represents a ‘volatile’-qualified variant of this type. d27204 3 a27206 3 Return a new ‘gdb.Type’ object which represents an unqualified variant of this type. That is, the result is neither ‘const’ nor ‘volatile’. d27209 4 a27212 4 Return a Python ‘Tuple’ object that contains two elements: the low bound of the argument type and the high bound of that type. If the type does not have a range, GDB will raise a ‘gdb.error’ exception (*note Exception Handling::). d27215 1 a27215 1 Return a new ‘gdb.Type’ object which represents a reference to this d27219 1 a27219 1 Return a new ‘gdb.Type’ object which represents a pointer to this d27223 1 a27223 1 Return a new ‘gdb.Type’ that represents the real type, after d27227 1 a27227 1 Return a new ‘gdb.Type’ object which represents the target type of d27231 5 a27235 5 object. For an array type (meaning C-like arrays), the target type is the type of the elements of the array. For a function or method type, the target type is the type of the return value. For a complex type, the target type is the type of the elements. For a typedef, the target type is the aliased type. d27241 2 a27242 2 If this ‘gdb.Type’ is an instantiation of a template, this will return a new ‘gdb.Value’ or ‘gdb.Type’ which represents the value d27245 1 a27245 1 If this ‘gdb.Type’ is not a template type, or if the type has fewer d27253 1 a27253 1 Return ‘gdb.Value’ instance of this type whose value is optimized d27259 1 a27259 1 defined in the ‘gdb’ module: d27261 1 a27261 1 ‘gdb.TYPE_CODE_PTR’ d27264 1 a27264 1 ‘gdb.TYPE_CODE_ARRAY’ d27267 1 a27267 1 ‘gdb.TYPE_CODE_STRUCT’ d27270 1 a27270 1 ‘gdb.TYPE_CODE_UNION’ d27273 1 a27273 1 ‘gdb.TYPE_CODE_ENUM’ d27276 1 a27276 1 ‘gdb.TYPE_CODE_FLAGS’ d27279 1 a27279 1 ‘gdb.TYPE_CODE_FUNC’ d27282 1 a27282 1 ‘gdb.TYPE_CODE_INT’ d27285 1 a27285 1 ‘gdb.TYPE_CODE_FLT’ d27288 2 a27289 2 ‘gdb.TYPE_CODE_VOID’ The special type ‘void’. d27291 1 a27291 1 ‘gdb.TYPE_CODE_SET’ d27294 1 a27294 1 ‘gdb.TYPE_CODE_RANGE’ d27297 1 a27297 1 ‘gdb.TYPE_CODE_STRING’ d27302 1 a27302 1 ‘gdb.TYPE_CODE_BITSTRING’ d27305 1 a27305 1 ‘gdb.TYPE_CODE_ERROR’ d27308 1 a27308 1 ‘gdb.TYPE_CODE_METHOD’ d27311 1 a27311 1 ‘gdb.TYPE_CODE_METHODPTR’ d27314 1 a27314 1 ‘gdb.TYPE_CODE_MEMBERPTR’ d27317 1 a27317 1 ‘gdb.TYPE_CODE_REF’ d27320 1 a27320 1 ‘gdb.TYPE_CODE_RVALUE_REF’ d27323 1 a27323 1 ‘gdb.TYPE_CODE_CHAR’ d27326 1 a27326 1 ‘gdb.TYPE_CODE_BOOL’ d27329 1 a27329 1 ‘gdb.TYPE_CODE_COMPLEX’ d27332 1 a27332 1 ‘gdb.TYPE_CODE_TYPEDEF’ d27335 1 a27335 1 ‘gdb.TYPE_CODE_NAMESPACE’ d27338 1 a27338 1 ‘gdb.TYPE_CODE_DECFLOAT’ d27341 1 a27341 1 ‘gdb.TYPE_CODE_INTERNAL_FUNCTION’ d27345 1 a27345 1 ‘gdb.TYPE_CODE_XMETHOD’ d27349 1 a27349 1 ‘gdb.TYPE_CODE_FIXED_POINT’ d27352 1 a27352 1 ‘gdb.TYPE_CODE_NAMESPACE’ d27355 1 a27355 1 Further support for types is provided in the ‘gdb.types’ Python d27372 1 a27372 1 To allow extensibility, GDB provides the ‘gdb.ValuePrinter’ base d27375 6 a27380 6 printers, GDB reserves all attributes starting with a lower-case letter. That is, in the future, GDB may add a new method or attribute to the pretty-printer protocol, and ‘gdb.ValuePrinter’-based printers are expected to handle this gracefully. A simple way to do this would be to use a leading underscore (or two, following the Python name-mangling scheme) to any attributes local to the implementation. d27392 2 a27393 2 This is a basic method, and is optional. If it does not exist, GDB will act as though the value has no children. d27395 1 a27395 1 For efficiency, the ‘children’ method should lazily compute its d27398 1 a27398 1 ‘-var-list-children’ (*note GDB/MI Variable Objects::) limit the d27401 2 a27402 2 Children may be hidden from display based on the value of ‘set print max-depth’ (*note Print Settings::). d27407 1 a27407 1 consumer as a ‘displayhint’ attribute of the variable being d27411 1 a27411 1 method must return a string or the special value ‘None’. d27415 1 a27415 1 ‘array’ d27417 2 a27418 2 CLI uses this to respect parameters such as ‘set print elements’ and ‘set print array’. d27420 4 a27423 4 ‘map’ Indicate that the object being printed is "map-like", and that the children of this value can be assumed to alternate between keys and values. d27425 1 a27425 1 ‘string’ d27427 1 a27427 1 the printer's ‘to_string’ method returns a Python string of d27431 1 a27431 1 characters, respecting ‘set print elements’, and the like. d27433 1 a27433 1 The special value ‘None’ causes GDB to apply the default display d27442 2 a27443 2 When printing from the CLI, if the ‘to_string’ method exists, then GDB will prepend its result to the values returned by ‘children’. d27446 3 a27448 3 the print settings (*note Print Settings::), the CLI may print just the result of ‘to_string’ in a stack trace, omitting the result of ‘children’. d27452 1 a27452 1 Otherwise, if this method returns an instance of ‘gdb.Value’, then d27457 1 a27457 1 to a ‘gdb.Value’, then GDB performs the conversion and prints the d27460 1 a27460 1 and strings are convertible to ‘gdb.Value’; other types are not. d27462 1 a27462 1 Finally, if this method returns ‘None’ then no further operations d27469 1 a27469 1 objects derived from ‘gdb.ValuePrinter’. d27472 1 a27472 1 ‘None’ may be returned if the number can't readily be computed. d27476 1 a27476 1 objects derived from ‘gdb.ValuePrinter’. d27483 1 a27483 1 pretty-printer for a ‘gdb.Value’: d27486 1 a27486 1 This function takes a ‘gdb.Value’ object as an argument. If a d27488 1 a27488 1 such printer exists, then this returns ‘None’. d27491 3 a27493 3 (including temporarily applied settings, such as ‘/x’) simply by calling ‘Value.format_string’ (*note Values From Inferior::). However, these settings can also be queried directly: d27497 2 a27498 2 given to ‘Value.format_string’, and whose values are the user's settings. During a ‘print’ or other operation, the values will d27513 2 a27514 2 possible: that is prefer a specific objfile first, then a program space, and only register a printer globally as a last resort. d27517 1 a27517 1 The Python list ‘gdb.pretty_printers’ contains an array of d27520 1 a27520 1 ‘global’ printers, they're available when debugging all inferiors. d27522 2 a27523 2 Each ‘gdb.Progspace’ contains a ‘pretty_printers’ attribute. Each ‘gdb.Objfile’ also contains a ‘pretty_printers’ attribute. d27525 1 a27525 1 Each function on these lists is passed a single ‘gdb.Value’ argument d27528 1 a27528 1 create a pretty-printer for the value, it should return ‘None’. d27530 3 a27532 3 GDB first checks the ‘pretty_printers’ attribute of each ‘gdb.Objfile’ in the current program space and iteratively calls each enabled lookup routine in the list for that ‘gdb.Objfile’ until it d27537 1 a27537 1 ‘gdb.pretty_printers’ list, again calling each enabled function until an d27546 2 a27547 2 underlying data structure may have changed and the pretty-printer is out of date. d27551 1 a27551 1 For example, if ‘print frame-arguments’ is on, a backtrace can become d27554 1 a27554 1 Pretty-printers are enabled and disabled by attaching an ‘enabled’ d27556 1 a27556 1 attribute is present and its value is ‘False’, the printer is disabled, d27568 1 a27568 1 Here is an example showing how a ‘std::string’ printer might be d27570 1 a27570 1 must provide. Note that this example uses the ‘gdb.ValuePrinter’ base d27600 1 a27600 1 returns ‘None’. d27603 3 a27605 3 package. If your pretty-printers are for use with a library, we further recommend embedding a version number into the package name. This practice will enable GDB to load multiple versions of your d27611 3 a27613 3 An ideal auto-load file will consist solely of ‘import’s of your printer modules, followed by a call to a register pretty-printers with the current objfile. d27618 5 a27622 5 GDB is able to load both sets of printers simultaneously. Then, because the search for pretty-printers is done by objfile, and because your auto-loaded code took care to register your library's printers with a specific objfile, GDB will find the correct printers for the specific version of the library used by each inferior. d27624 2 a27625 2 To continue the ‘std::string’ example (*note Pretty Printing API::), this code might appear in ‘gdb.libstdcxx.v6’: d27635 2 a27636 2 The previous example illustrates a basic pretty-printer. There are a few things that can be improved on. The printer doesn't have a name, d27644 4 a27647 4 lookup function recognize several types. The latter is the conventional way this is handled. If a pretty-printer can handle multiple data types, then its “subprinters” are the printers for the individual data types. d27649 1 a27649 1 The ‘gdb.printing’ module provides a formal way of solving these d27681 1 a27681 1 ‘gdb.printing’ module. Instead a function is provided to build up the d27702 1 a27702 1 corresponding output of ‘info pretty-printer’: d27719 1 a27719 1 A “type printer” is just a Python object conforming to a certain d27721 1 a27721 1 see *note gdb.types::. A type printer must supply at least: d27725 2 a27726 2 otherwise. This is manipulated by the ‘enable type-printer’ and ‘disable type-printer’ commands. d27729 3 a27731 2 The name of the type printer. This must be a string. This is used by the ‘enable type-printer’ and ‘disable type-printer’ commands. d27736 1 a27736 1 new object that supplies a ‘recognize’ method, as described below. d27738 9 a27746 9 When displaying a type, say via the ‘ptype’ command, GDB will compute a list of type recognizers. This is done by iterating first over the per-objfile type printers (*note Objfiles In Python::), followed by the per-progspace type printers (*note Progspaces In Python::), and finally the global type printers. GDB will call the ‘instantiate’ method of each enabled type printer. If this method returns ‘None’, then the result is ignored; otherwise, it is appended to the list of recognizers. d27750 1 a27750 1 stopping if the function returns a non-‘None’ value. The recognition d27754 1 a27754 1 If TYPE is not recognized, return ‘None’. Otherwise, return a d27756 1 a27756 1 argument will be an instance of ‘gdb.Type’ (*note Types In d27759 7 a27765 6 GDB uses this two-pass approach so that type printers can efficiently cache information without holding on to it too long. For example, it can be convenient to look up type information in a type printer and hold it for a recognizer's lifetime; if a single pass were done then type printers would have to make use of the event system in order to avoid holding information that could become stale as the inferior changed. d27780 3 a27782 3 ‘backtrace’ (*note The backtrace command: backtrace-command.), ‘-stack-list-frames’ (*note The -stack-list-frames command: -stack-list-frames.), ‘-stack-list-variables’ (*note The d27784 2 a27785 2 ‘-stack-list-arguments’ *note The -stack-list-arguments command: -stack-list-arguments.) and ‘-stack-list-locals’ (*note The d27789 11 a27799 11 actions to the contents of that iterator, and returning another iterator (or, possibly, the same iterator it was provided in the case where the filter does not perform any operations). Typically, frame filters utilize tools such as the Python's ‘itertools’ module to work with and create new iterators from the source iterator. Regardless of how a filter chooses to apply actions, it must not alter the underlying GDB frame or frames, or attempt to alter the call-stack within GDB. This preserves data integrity within GDB. Frame filters are executed on a priority basis and care should be taken that some frame filters may have been executed before, and that some frame filters will be executed after. d27803 2 a27804 2 call stack if possible. Some stacks can run very deep, into the tens of thousands in some cases. To search every frame when a frame filter d27815 10 a27824 10 The Python dictionary ‘gdb.frame_filters’ contains key/object pairings that comprise a frame filter. Frame filters in this dictionary are called ‘global’ frame filters, and they are available when debugging all inferiors. These frame filters must register with the dictionary directly. In addition to the ‘global’ dictionary, there are other dictionaries that are loaded with different inferiors via auto-loading (*note Python Auto-loading::). The two other areas where frame filter dictionaries can be found are: ‘gdb.Progspace’ which contains a ‘frame_filters’ dictionary attribute, and each ‘gdb.Objfile’ object which also contains a ‘frame_filters’ dictionary attribute. d27827 2 a27828 2 filters, GDB combines the ‘global’, ‘gdb.Progspace’ and all ‘gdb.Objfile’ dictionaries currently loaded. All of the ‘gdb.Objfile’ d27831 2 a27832 2 ‘enabled’ attribute is ‘False’. This pruned list is then sorted according to the ‘priority’ attribute in each filter. d27834 5 a27838 4 Once the dictionaries are combined, pruned and sorted, GDB creates an iterator which wraps each frame in the call stack in a ‘FrameDecorator’ object, and calls each filter in order. The output from the previous filter will always be the input to the next filter, and so on. d27844 2 a27845 2 GDB will call this method on a frame filter when it has reached the order in the priority list for that filter. d27860 2 a27861 2 Note that the output from ‘Filter3’ is passed to the input of ‘Filter2’, and so on. d27863 11 a27873 10 This ‘filter’ method is passed a Python iterator. This iterator contains a sequence of frame decorators that wrap each ‘gdb.Frame’, or a frame decorator that wraps another frame decorator. The first filter that is executed in the sequence of frame filters will receive an iterator entirely comprised of default ‘FrameDecorator’ objects. However, after each frame filter is executed, the previous frame filter may have wrapped some or all of the frame decorators with their own frame decorator. As frame decorators must also conform to a mandatory interface, these decorators can be assumed to act in a uniform manner (*note Frame Decorator API::). d27885 1 a27885 1 The ‘name’ attribute must be Python string which contains the name d27892 4 a27895 4 The ‘enabled’ attribute must be Python boolean. This attribute indicates to GDB whether the frame filter is enabled, and should be considered when frame filters are executed. If ‘enabled’ is ‘True’, then the frame filter will be executed when any of the d27897 1 a27897 1 If ‘enabled’ is ‘False’, then the frame filter will not be d27901 1 a27901 1 The ‘priority’ attribute must be Python integer. This attribute d27903 2 a27904 2 There are no imposed limits on the range of ‘priority’ other than it must be a valid integer. The higher the ‘priority’ attribute, d27906 1 a27906 1 frame filters. Although ‘priority’ can be negative, it is d27918 3 a27920 3 Frame decorators are sister objects to frame filters (*note Frame Filter API::). Frame decorators are applied by a frame filter and can only be used in conjunction with frame filters. d27923 1 a27923 1 of each ‘gdb.Frame’ in commands where frame filters are executed. This d27925 2 a27926 2 ‘gdb.Frame’ with Python code contained within each API call. This separates the actual data contained in a ‘gdb.Frame’ from the decorated d27928 1 a27928 1 maintain integrity of the data contained in each ‘gdb.Frame’. d27932 5 a27936 4 GDB already contains a frame decorator called ‘FrameDecorator’. This contains substantial amounts of boilerplate code to decorate the content of a ‘gdb.Frame’. It is recommended that other frame decorators inherit and extend this object, and only to override the methods needed. d27938 2 a27939 2 ‘FrameDecorator’ is defined in the Python module ‘gdb.FrameDecorator’, so your code can import it like: d27943 1 a27943 2 The ‘elided’ method groups frames together in a hierarchical d27945 4 a27948 4 low-level frames make up a single call in the interpreted language. In this example, the frame filter would elide the low-level frames and present a single high-level frame, representing the call in the interpreted language, to the user. d27950 1 a27950 1 The ‘elided’ function must return an iterable and this iterable d27953 3 a27955 3 return an empty iterable, or ‘None’. Elided frames are indented from normal frames in a ‘CLI’ backtrace, or in the case of GDB/MI, are placed in the ‘children’ field of the eliding frame. a27961 1 d27966 1 a27966 1 ‘None’. d27968 1 a27968 1 If this function returns ‘None’, GDB will not print any data for a27971 1 d27975 1 a27975 1 size to describe the address of the frame, or ‘None’. d27977 1 a27977 1 If this function returns a ‘None’, GDB will not print any data for a27980 1 d27985 1 a27985 1 the path to the object file backing the frame, or ‘None’. d27987 1 a27987 1 If this function returns a ‘None’, GDB will not print any data for a27990 1 d27994 1 a27994 1 This method must return a Python integer type, or ‘None’. d27996 1 a27996 1 If this function returns a ‘None’, GDB will not print any data for d28000 4 d28005 2 a28006 7 This method must return an iterable, or ‘None’. Returning an empty iterable, or ‘None’ means frame arguments will not be printed for this frame. This iterable must contain objects that implement two methods, described here. This object must implement a ‘symbol’ method which takes a single ‘self’ parameter and must return a ‘gdb.Symbol’ (*note Symbols In d28008 5 a28012 5 ‘value’ method which takes a single ‘self’ parameter and must return a ‘gdb.Value’ (*note Values From Inferior::), a Python value, or ‘None’. If the ‘value’ method returns ‘None’, and the ‘argument’ method returns a ‘gdb.Symbol’, GDB will look-up and print the value of the ‘gdb.Symbol’ automatically. d28051 3 a28053 4 This method must return an iterable or ‘None’. Returning an empty iterable, or ‘None’ means frame local arguments will not be printed for this frame. d28057 1 a28057 1 described in the ‘frame_args’ function, (*note The frame filter d28083 1 a28083 2 This method must return the underlying ‘gdb.Frame’ that this frame d28085 2 a28086 2 internal frame information to determine how to print certain values when printing a frame. d28096 5 a28100 4 API::), it must register itself with GDB, and finally, it must decide if it is to work on the data provided by GDB. In all cases, whether it works on the iterator or not, each frame filter must return an iterator. A bare-bones frame filter follows the pattern in the following example. d28135 2 a28136 2 the comments the filter assigns the following attributes: ‘name’, ‘priority’ and whether the filter should be enabled with the ‘enabled’ d28142 2 a28143 2 ‘gdb.frame_filters’. As noted earlier, ‘gdb.frame_filters’ is a dictionary that is initialized in the ‘gdb’ module when GDB starts. d28146 1 a28146 1 registered either in the ‘objfile’ or ‘progspace’ dictionaries as they d28152 2 a28153 2 usage of the filter currently in question. *Note Python Auto-loading::, for further information on auto-loading Python scripts. d28156 15 a28170 15 therefore it is the frame filter's responsibility to ensure registration has occurred, and that any exceptions are handled appropriately. In particular, you may wish to handle exceptions relating to Python dictionary key uniqueness. It is mandatory that the dictionary key is the same as frame filter's ‘name’ attribute. When a user manages frame filters (*note Frame Filter Management::), the names GDB will display are those contained in the ‘name’ attribute. The final step of this example is the implementation of the ‘filter’ method. As shown in the example comments, we define the ‘filter’ method and note that the method must take an iterator, and also must return an iterator. In this bare-bones example, the frame filter is not very useful as it just returns the iterator untouched. However this is a valid operation for frame filters that have the ‘enabled’ attribute set, but decide not to operate on any frames. d28179 1 a28179 1 decorator to all frames with the Python ‘itertools imap’ method, the d28186 11 a28196 11 decisions at the filtering step beyond mapping a frame decorator to each frame. This allows the actual decision making to be performed when each frame is printed. This is an important consideration, and well worth reflecting upon when designing a frame filter. An issue that frame filters should avoid is unwinding the stack if possible. Some stacks can run very deep, into the tens of thousands in some cases. To search every frame to determine if it is inlined ahead of time may be too expensive at the filtering step. The frame filter cannot know how many frames it has to iterate over, and it would have to iterate through them all. This ends up duplicating effort as GDB performs this iteration when it prints the frames. d28202 4 a28205 4 the printing step would undertake anyway. Also, if there are many frame filters unwinding the stack during filtering, it can substantially delay the printing of the backtrace which will result in large memory usage, and a poor user experience. d28221 5 a28225 5 that the ‘filter’ method applies a frame decorator object called ‘InlinedFrameDecorator’ to each element in the iterator. The ‘imap’ Python method is light-weight. It does not proactively iterate over the iterator, but rather creates a new iterator which wraps the existing one. d28243 2 a28244 2 This frame decorator only defines and overrides the ‘function’ method. It lets the supplied ‘FrameDecorator’, which is shipped with d28257 2 a28258 2 each frame decorator which then makes a decision on what to print in the ‘function’ callback. Using a strategy like this is a way to defer d28266 1 a28266 1 want to hierarchically represent frames, the ‘elided’ frame decorator d28269 4 a28272 4 This example approaches the issue with the ‘elided’ method. This example is quite long, but very simplistic. It is out-of-scope for this section to write a complete example that comprehensively covers all approaches of finding and printing inlined frames. However, this d28290 1 a28290 1 (‘frame_iter’) with a custom iterator called ‘ElidingInlineIterator’. d28317 2 a28318 2 ‘next’ function is called (when GDB prints each frame), the iterator checks if this frame decorator, ‘frame’, is wrapping an inlined frame. d28321 1 a28321 1 contained within the next oldest frame, ‘eliding_frame’, which it d28323 1 a28323 1 ‘ElidingFrameDecorator’, which contains both the elided frame, and the d28337 3 a28339 3 frame in the ‘elided’ method. As before it lets ‘FrameDecorator’ do the rest of the work involved in printing this frame. This produces the following output. d28345 3 a28347 3 In that output, ‘max’ which has been inlined into ‘main’ is printed hierarchically. Another approach would be to combine the ‘function’ method, and the ‘elided’ method to both print a marker in the inlined d28372 4 a28375 4 two attributes, ‘name’ and ‘enabled’, with obvious meanings, and a single method ‘__call__’, which examines a given frame and returns an object (an instance of ‘gdb.UnwindInfo class)’ describing it. If an unwinder does not recognize a frame, it should return ‘None’. The code d28389 2 a28390 2 An object passed to an unwinder (a ‘gdb.PendingFrame’ instance) provides a method to read frame's registers: d28394 4 a28397 4 ‘gdb.Value’ object. For a description of the acceptable values of REGISTER see *note Frame.read_register: gdbpy_frame_read_register. If REGISTER does not name a register for the current architecture, this method will throw an exception. d28399 1 a28399 1 Note that this method will always return a ‘gdb.Value’ for a valid d28403 1 a28403 1 ‘gdb.Value’ returned from this method will be lazy; that is, its d28405 2 a28406 2 attempting to use such a value will cause an exception at the point of use. d28408 1 a28408 1 The type of the returned ‘gdb.Value’ depends on the register and d28410 1 a28410 1 type, like ‘long long’; but many other types are possible, such as d28413 1 a28413 1 It also provides a factory method to create a ‘gdb.UnwindInfo’ d28417 1 a28417 1 Returns a new ‘gdb.UnwindInfo’ instance identified by given d28422 7 a28428 6 ‘sp, pc’ The frame is identified by the given stack address and PC. The stack address must be chosen so that it is constant throughout the lifetime of the frame, so a typical choice is the value of the stack pointer at the start of the function--in the DWARF standard, this would be the "Call Frame Address". d28431 2 a28432 2 documented for completeness but are only useful in specialized situations. d28434 1 a28434 1 ‘sp, pc, special’ d28442 1 a28442 1 ‘sp’ d28448 5 a28452 2 Each attribute value should either be an instance of ‘gdb.Value’ or an integer. a28453 2 A helper class is provided in the ‘gdb.unwinder’ module that can be used to represent a frame-id (*note gdb.unwinder.FrameId::). d28456 3 a28458 3 Return the ‘gdb.Architecture’ (*note Architectures In Python::) for this ‘gdb.PendingFrame’. This represents the architecture of the particular frame being unwound. d28465 1 a28465 1 Returns the function name of this pending frame, or ‘None’ if it d28469 1 a28469 1 Returns true if the ‘gdb.PendingFrame’ object is valid, false if d28473 1 a28473 1 All ‘gdb.PendingFrame’ methods, except this one, will raise an d28484 1 a28484 1 raise a ‘RuntimeError’ exception. d28500 3 a28502 3 Use ‘PendingFrame.create_unwind_info’ method described above to create a ‘gdb.UnwindInfo’ instance. Use the following method to specify caller registers that have been saved in this frame: d28506 1 a28506 1 acceptable values see *note Frame.read_register: d28508 1 a28508 1 ‘gdb.Value’ object). d28510 1 a28510 1 The ‘gdb.unwinder’ Module d28513 1 a28513 1 GDB comes with a ‘gdb.unwinder’ module which contains the following d28517 1 a28517 1 The ‘Unwinder’ class is a base class from which user created d28520 1 a28520 1 the required ‘name’ and ‘enabled’ attributes. d28531 2 a28532 2 A modifiable attribute containing a boolean; when ‘True’, the unwinder is enabled, and will be used by GDB. When ‘False’, d28537 1 a28537 1 calling ‘gdb.PendingFrame.create_unwind_info’. It is not required d28542 1 a28542 1 ‘gdb.unwinder.FrameId’ has the following method: d28544 2 a28545 1 -- Function: gdb.unwinder.FrameId.__init__(sp, pc, special = None) d28547 1 a28547 1 ‘gdb.Value’ object, or an integer. d28550 1 a28550 1 ‘gdb.Value’ object, or an integer. d28552 1 a28552 1 ‘gdb.unwinder.FrameId’ has the following read-only attributes: d28561 1 a28561 1 The SPECIAL value passed to the constructor, or ‘None’ if no d28567 2 a28568 2 Object files and program spaces can have unwinders registered with them. In addition, you can register unwinders globally. d28570 1 a28570 1 The ‘gdb.unwinders’ module provides the function to register an d28575 10 a28584 9 LOCUS specifies to which unwinder list to prepend the UNWINDER. It can be either an object file (*note Objfiles In Python::), a program space (*note Progspaces In Python::), or ‘None’, in which case the unwinder is registered globally. The newly added UNWINDER will be called before any other unwinder from the same locus. Two unwinders in the same locus cannot have the same name. An attempt to add an unwinder with an already existing name raises an exception unless REPLACE is ‘True’, in which case the old unwinder is deleted and the new unwinder is registered in its place. d28627 1 a28627 1 ‘info unwinder [ LOCUS [ NAME-REGEXP ] ]’ d28632 1 a28632 1 The LOCUS argument should be either ‘global’, ‘progspace’, or the d28639 3 a28641 2 ‘disable unwinder [ LOCUS [ NAME-REGEXP ] ]’ The LOCUS and NAME-REGEXP are interpreted as in ‘info unwinder’ d28643 5 a28647 4 matching unwinders are disabled. The ‘enabled’ field of each matching unwinder is set to ‘False’. ‘enable unwinder [ LOCUS [ NAME-REGEXP ] ]’ The LOCUS and NAME-REGEXP are interpreted as in ‘info unwinder’ d28649 2 a28650 2 matching unwinders are enabled. The ‘enabled’ field of each matching unwinder is set to ‘True’. d28658 1 a28658 1 “Xmethods” are additional methods or replacements for existing methods d28672 28 a28699 27 “xmethod matcher” and an “xmethod worker”. To implement an xmethod, one has to implement a matcher and a corresponding worker for it (more than one worker can be implemented, each catering to a different overloaded instance of the method). Internally, GDB invokes the ‘match’ method of a matcher to match the class type and method name. On a match, the ‘match’ method returns a list of matching _worker_ objects. Each worker object typically corresponds to an overloaded instance of the xmethod. They implement a ‘get_arg_types’ method which returns a sequence of types corresponding to the arguments the xmethod requires. GDB uses this sequence of types to perform overload resolution and picks a winning xmethod worker. A winner is also selected from among the methods GDB finds in the C++ source code. Next, the winning xmethod worker and the winning C++ method are compared to select an overall winner. In case of a tie between a xmethod worker and a C++ method, the xmethod worker is selected as the winner. That is, if a winning xmethod worker is found to be equivalent to the winning C++ method, then the xmethod worker is treated as a replacement for the C++ method. GDB uses the overall winner to invoke the method. If the winning xmethod worker is the overall winner, then the corresponding xmethod is invoked via the ‘__call__’ method of the worker object. If one wants to implement an xmethod as a replacement for an existing C++ method, then they have to implement an equivalent xmethod which has exactly the same name and takes arguments of exactly the same type as the C++ method. If the user wants to invoke the C++ method even though a replacement xmethod is available for that method, then they can disable the xmethod. d28715 2 a28716 2 ‘XMethodMatcher’ defined in the module ‘gdb.xmethod’, or an object with similar interface and attributes. An instance of ‘XMethodMatcher’ has d28727 3 a28729 3 A list of named methods managed by the matcher. Each object in the list is an instance of the class ‘XMethod’ defined in the module ‘gdb.xmethod’, or any object with the following attributes: d28731 1 a28731 1 ‘name’ d28735 1 a28735 1 ‘enabled’ d28739 2 a28740 1 The class ‘XMethod’ is a convenience class with same attributes as d28746 1 a28746 1 The ‘XMethodMatcher’ class has the following methods: d28750 1 a28750 1 ‘methods’ attribute is initialized to ‘None’. d28756 4 a28759 4 ‘gdb.Type’ object, and METHOD_NAME is a string value. If the matcher manages named methods as listed in its ‘methods’ attribute, then only those worker objects whose corresponding entries in the ‘methods’ list are enabled should be returned. d28762 1 a28762 1 ‘XMethodWorker’ defined in the module ‘gdb.xmethod’, or support the d28766 1 a28766 1 This method returns a sequence of ‘gdb.Type’ objects corresponding d28768 2 a28769 2 sequence or ‘None’ if the xmethod does not take any arguments. If the xmethod takes a single argument, then a single ‘gdb.Type’ d28773 4 a28776 4 This method returns a ‘gdb.Type’ object representing the type of the result of invoking this xmethod. The ARGS argument is the same tuple of arguments that would be passed to the ‘__call__’ method of this worker. d28782 1 a28782 1 the ‘this’ pointer value. d28784 3 a28786 2 For GDB to lookup xmethods, the xmethod matchers should be registered using the following function defined in the module ‘gdb.xmethod’: d28789 6 a28794 5 The ‘matcher’ is registered with ‘locus’, replacing an existing matcher with the same name as ‘matcher’ if ‘replace’ is ‘True’. ‘locus’ can be a ‘gdb.Objfile’ object (*note Objfiles In Python::), or a ‘gdb.Progspace’ object (*note Progspaces In Python::), or ‘None’. If it is ‘None’, then ‘matcher’ is registered globally. d28803 2 a28804 2 matchers and xmethod workers (*note Xmethods In Python::). Consider the following C++ class: d28824 4 a28827 4 Let us define two xmethods for the class ‘MyClass’, one replacing the method ‘geta’, and another adding an overloaded flavor of ‘operator+’ which takes a ‘MyClass’ argument (the C++ code above already has an overloaded ‘operator+’ which takes an ‘int’ argument). The xmethod d28866 12 a28877 11 Notice that the ‘match’ method of ‘MyClassMatcher’ returns a worker object of type ‘MyClassWorker_geta’ for the ‘geta’ method, and a worker object of type ‘MyClassWorker_plus’ for the ‘operator+’ method. This is done indirectly via helper classes derived from ‘gdb.xmethod.XMethod’. One does not need to use the ‘methods’ attribute in a matcher as it is optional. However, if a matcher manages more than one xmethod, it is a good practice to list the xmethods in the ‘methods’ attribute of the matcher. This will then facilitate enabling and disabling individual xmethods via the ‘enable/disable’ commands. Notice also that a worker object is returned only if the corresponding entry in the ‘methods’ attribute of the matcher is enabled. d28909 1 a28909 1 If an object ‘obj’ of type ‘MyClass’ is initialized in C++ code as d28915 2 a28916 2 workers into GDB, invoking the method ‘geta’ or using the operator ‘+’ on ‘obj’ will invoke the xmethods defined above: d28944 1 a28944 1 replacement for the ‘footprint’ method. The full code listing of the d28973 1 a28973 1 Notice that, in this example, we have not used the ‘methods’ d28986 2 a28987 2 information about and manipulate inferiors controlled by GDB via objects of the ‘gdb.Inferior’ class. d28989 1 a28989 1 The following inferior-related functions are available in the ‘gdb’ d28998 1 a28998 1 A ‘gdb.Inferior’ object has the following attributes: d29006 2 a29007 2 The ‘gdb.TargetConnection’ for this inferior (*note Connections In Python::), or ‘None’ if this inferior has no connection. d29011 4 a29014 4 inferior is not connected to a target. *Note Inferiors Connections and Programs::. This is equivalent to ‘gdb.Inferior.connection.num’ in the case where ‘gdb.Inferior.connection’ is not ‘None’. d29021 1 a29021 1 Boolean signaling whether the inferior was created using 'attach', d29027 1 a29027 1 ‘None’. d29034 1 a29034 1 to the ‘set args’ and ‘show args’ commands. *Note Arguments::. d29038 1 a29038 1 If there are no arguments, the value is ‘None’. d29045 1 a29045 1 A ‘gdb.Inferior’ object has the following methods: d29048 4 a29051 4 Returns ‘True’ if the ‘gdb.Inferior’ object is valid, ‘False’ if not. A ‘gdb.Inferior’ object will become invalid if the inferior no longer exists within GDB. All other ‘gdb.Inferior’ methods will throw an exception if it is invalid at the time the method is d29060 5 a29064 5 Return the ‘gdb.Architecture’ (*note Architectures In Python::) for this inferior. This represents the architecture of the inferior as a whole. Some platforms can have multiple architectures in a single address space, so this may not match the architecture of a particular frame (*note Frames In Python::). d29067 4 a29070 4 Read LENGTH addressable memory units from the inferior, starting at ADDRESS. Returns a ‘memoryview’ object, which behaves much like an array or a string. It can be modified and given to the ‘Inferior.write_memory’ function. d29076 1 a29076 1 from ‘Inferior.read_memory’. If given, LENGTH determines the d29080 7 a29086 7 Search a region of the inferior memory starting at ADDRESS with the given LENGTH using the search pattern supplied in PATTERN. The PATTERN parameter must be a Python object which supports the buffer protocol, i.e., a string, an array or the object returned from ‘gdb.read_memory’. Returns a Python ‘Long’ containing the address where the pattern was found, or ‘None’ if the pattern could not be found. d29090 1 a29090 1 specific data structure such as ‘pthread_t’ for pthreads library d29093 3 a29095 3 The function ‘Inferior.thread_from_thread_handle’ provides the same functionality, but use of ‘Inferior.thread_from_thread_handle’ is deprecated. d29113 1 a29113 1 One may add arbitrary attributes to ‘gdb.Inferior’ objects in the d29159 1 a29159 1 An “event” is just an object that describes some state change. The d29164 2 a29165 2 handler with an “event registry”. An event registry is an object in the ‘gdb.events’ module which dispatches particular events. A registry d29187 6 a29192 5 In the above example we connect our handler ‘exit_handler’ to the registry ‘events.exited’. Once connected, ‘exit_handler’ gets called when the inferior exits. The argument “event” in this example is of type ‘gdb.ExitedEvent’. As you can see in the example the ‘ExitedEvent’ object has an attribute which indicates the exit code of the inferior. d29196 1 a29196 1 ‘gdb.ThreadEvent’. This event is a base class and is never emitted d29199 1 a29199 1 ‘gdb.BreakpointEvent’ and ‘gdb.ContinueEvent’. ‘gdb.ThreadEvent’ holds d29204 2 a29205 2 which was involved in the emitted event. Otherwise, it will be set to ‘None’. d29207 2 a29208 2 The following is a listing of the event registries that are available and details of the events they emit: d29210 2 a29211 2 ‘events.cont’ Emits ‘gdb.ContinueEvent’, which extends ‘gdb.ThreadEvent’. This d29213 1 a29213 1 For inherited attribute refer to ‘gdb.ThreadEvent’ above. d29215 3 a29217 3 ‘events.exited’ Emits ‘events.ExitedEvent’, which indicates that the inferior has exited. ‘events.ExitedEvent’ has two attributes: d29220 4 a29223 4 An integer representing the exit code, if available, which the inferior has returned. (The exit code could be unavailable if, for example, GDB detaches from the inferior.) If the exit code is unavailable, the attribute does not exist. d29226 1 a29226 1 A reference to the inferior which triggered the ‘exited’ d29229 2 a29230 2 ‘events.stop’ Emits ‘gdb.StopEvent’, which extends ‘gdb.ThreadEvent’. d29233 4 a29236 4 this registry extend ‘gdb.StopEvent’. As a child of ‘gdb.ThreadEvent’, ‘gdb.StopEvent’ will indicate the stopped thread when GDB is running in non-stop mode. Refer to ‘gdb.ThreadEvent’ above for more details. d29238 1 a29238 1 ‘gdb.StopEvent’ has the following additional attributes: d29250 1 a29250 1 When a ‘StopEvent’ results from a ‘finish’ command, it will d29252 3 a29254 3 available. This will be an entry named ‘return-value’ in the ‘details’ dictionary. The value of this entry will be a ‘gdb.Value’ object. d29256 1 a29256 1 Emits ‘gdb.SignalEvent’, which extends ‘gdb.StopEvent’. d29259 1 a29259 1 received a signal. ‘gdb.SignalEvent’ has the following attributes: d29264 1 a29264 1 command ‘info signals’ in the GDB command prompt. d29266 1 a29266 1 Also emits ‘gdb.BreakpointEvent’, which extends ‘gdb.StopEvent’. d29268 1 a29268 1 ‘gdb.BreakpointEvent’ event indicates that one or more breakpoints d29273 2 a29274 2 ‘gdb.Breakpoint’) that were hit. *Note Breakpoints In Python::, for details of the ‘gdb.Breakpoint’ object. d29279 1 a29279 1 deprecated in favor of the ‘gdb.BreakpointEvent.breakpoints’ d29282 3 a29284 3 ‘events.new_objfile’ Emits ‘gdb.NewObjFileEvent’ which indicates that a new object file has been loaded by GDB. ‘gdb.NewObjFileEvent’ has one attribute: d29287 1 a29287 1 A reference to the object file (‘gdb.Objfile’) which has been d29289 1 a29289 1 ‘gdb.Objfile’ object. d29291 4 a29294 4 ‘events.free_objfile’ Emits ‘gdb.FreeObjFileEvent’ which indicates that an object file is about to be removed from GDB. One reason this can happen is when the inferior calls ‘dlclose’. ‘gdb.FreeObjFileEvent’ has one d29298 1 a29298 1 A reference to the object file (‘gdb.Objfile’) which will be d29300 1 a29300 1 ‘gdb.Objfile’ object. d29302 2 a29303 2 ‘events.clear_objfiles’ Emits ‘gdb.ClearObjFilesEvent’ which indicates that the list of d29305 1 a29305 1 ‘gdb.ClearObjFilesEvent’ has one attribute: d29308 1 a29308 1 A reference to the program space (‘gdb.Progspace’) whose d29311 1 a29311 1 ‘events.inferior_call’ d29314 2 a29315 2 type ‘gdb.InferiorCallPreEvent’, and after an inferior call, this emits an event of type ‘gdb.InferiorCallPostEvent’. d29317 1 a29317 1 ‘gdb.InferiorCallPreEvent’ d29327 1 a29327 1 ‘gdb.InferiorCallPostEvent’ d29337 2 a29338 2 ‘events.memory_changed’ Emits ‘gdb.MemoryChangedEvent’ which indicates that the memory of d29340 1 a29340 1 command like ‘set *addr = value’. The event has the following d29349 3 a29351 3 ‘events.register_changed’ Emits ‘gdb.RegisterChangedEvent’ which indicates that a register in the inferior has been modified by the GDB user. d29356 1 d29360 1 a29360 1 ‘events.breakpoint_created’ d29362 1 a29362 1 argument that is passed is the new ‘gdb.Breakpoint’ object. d29364 1 a29364 1 ‘events.breakpoint_modified’ d29366 1 a29366 1 The argument that is passed is the new ‘gdb.Breakpoint’ object. d29368 1 a29368 1 ‘events.breakpoint_deleted’ d29370 3 a29372 3 that is passed is the ‘gdb.Breakpoint’ object. When this event is emitted, the ‘gdb.Breakpoint’ object will already be in its invalid state; that is, the ‘is_valid’ method will return ‘False’. d29374 1 a29374 1 ‘events.before_prompt’ d29378 1 a29378 1 ‘events.new_inferior’ d29383 1 a29383 1 The event is of type ‘gdb.NewInferiorEvent’. This has a single d29387 1 a29387 1 The new inferior, a ‘gdb.Inferior’ object. d29389 1 a29389 1 ‘events.inferior_deleted’ d29392 1 a29392 1 itself is removed, say via ‘remove-inferiors’. d29394 1 a29394 1 The event is of type ‘gdb.InferiorDeletedEvent’. This has a single d29398 1 a29398 1 The inferior that is being removed, a ‘gdb.Inferior’ object. d29400 1 a29400 1 ‘events.new_thread’ d29402 1 a29402 1 type ‘gdb.NewThreadEvent’, which extends ‘gdb.ThreadEvent’. This d29408 3 a29410 3 ‘events.thread_exited’ This is emitted when GDB notices a thread has exited. The event is of type ‘gdb.ThreadExitedEvent’ which extends ‘gdb.ThreadEvent’. d29416 1 a29416 1 ‘events.gdb_exiting’ d29419 1 a29419 1 signal. The event is of type ‘gdb.GdbExitingEvent’, which has a d29425 4 a29428 4 ‘events.connection_removed’ This is emitted when GDB removes a connection (*note Connections In Python::). The event is of type ‘gdb.ConnectionEvent’. This has a single read-only attribute: d29431 1 a29431 1 The ‘gdb.TargetConnection’ that is being removed. d29433 3 a29435 3 ‘events.executable_changed’ Emits ‘gdb.ExecutableChangedEvent’ which indicates that the ‘gdb.Progspace.executable_filename’ has changed. d29438 1 a29438 1 ‘gdb.Progspace.executable_filename ’ has changed to name a d29440 1 a29440 1 ‘gdb.Progspace.executable_filename’ has changed on disk, and GDB d29444 1 a29444 1 The ‘gdb.Progspace’ in which the current executable has d29446 1 a29446 1 visible in ‘gdb.Progspace.executable_filename’ (*note d29448 1 d29450 2 a29451 2 This attribute will be ‘True’ if the value of ‘gdb.Progspace.executable_filename’ didn't change, but the d29454 2 a29455 2 When this attribute is ‘False’, the value in ‘gdb.Progspace.executable_filename’ was changed to name a d29460 2 a29461 2 ‘gdb.Progspace.executable_filename’ and ‘gdb.Progspace.filename’ respectively. When using the ‘file’ command, GDB updates both of d29466 1 a29466 1 ‘events.new_progspace’ d29469 1 a29469 1 ‘gdb.NewProgspaceEvent’, and has a single read-only attribute: d29472 1 a29472 1 The ‘gdb.Progspace’ that was added to GDB. d29474 3 a29476 3 No ‘NewProgspaceEvent’ is emitted for the very first program space, which is assigned to the first inferior. This first program space is created within GDB before any Python scripts are sourced. d29478 1 a29478 1 ‘events.free_progspace’ d29481 1 a29481 1 of the ‘remove-inferiors’ command (*note ‘remove-inferiors’: d29483 1 a29483 1 ‘gdb.FreeProgspaceEvent’, and has a single read-only attribute: d29486 2 a29487 1 The ‘gdb.Progspace’ that is about to be removed from GDB. d29496 1 a29496 1 threads controlled by GDB, via objects of the ‘gdb.InferiorThread’ d29499 1 a29499 1 The following thread-related functions are available in the ‘gdb’ d29504 1 a29504 1 If there is no selected thread, this will return ‘None’. d29507 1 a29507 1 ‘Inferior.threads()’ method. *Note Inferiors In Python::. d29509 1 a29509 1 A ‘gdb.InferiorThread’ object has the following attributes: d29512 4 a29515 4 The name of the thread. If the user specified a name using ‘thread name’, then this returns that name. Otherwise, if an OS-supplied name is available, then it is returned. Otherwise, this returns ‘None’. d29518 1 a29518 1 object, which sets the new name, or ‘None’, which removes any d29525 1 a29525 1 The global ID of the thread, as assigned by GDB. You can use this d29532 4 a29535 4 Process ID (PID); the second is the Lightweight Process ID (LWPID), and the third is the Thread ID (TID). Either the LWPID or TID may be 0, which indicates that the operating system does not use that identifier. d29539 3 a29541 3 ‘InferiorThread.ptid’. This is the string that GDB uses in the ‘Target Id’ column in the ‘info threads’ output (*note ‘info threads’: info_threads.). d29544 3 a29546 2 The inferior this thread belongs to. This attribute is represented as a ‘gdb.Inferior’ object. This attribute is not writable. d29552 1 a29552 1 ‘None’. d29554 5 a29558 5 For example, on a GNU/Linux system, a thread that is in the process of exiting will return the string ‘Exiting’. For remote targets the ‘details’ string will be obtained with the ‘qThreadExtraInfo’ remote packet, if the target supports it (*note ‘qThreadExtraInfo’: qThreadExtraInfo.). d29560 2 a29561 2 GDB displays the ‘details’ string as part of the ‘Target Id’ column, in the ‘info threads’ output (*note ‘info threads’: d29564 1 a29564 1 A ‘gdb.InferiorThread’ object has the following methods: d29567 5 a29571 5 Returns ‘True’ if the ‘gdb.InferiorThread’ object is valid, ‘False’ if not. A ‘gdb.InferiorThread’ object will become invalid if the thread exits, or the inferior that the thread belongs is deleted. All other ‘gdb.InferiorThread’ methods will throw an exception if it is invalid at the time the method is called. d29587 5 a29591 5 Return the thread object's handle, represented as a Python ‘bytes’ object. A ‘gdb.Value’ representation of the handle may be constructed via ‘gdb.Value(bufobj, type)’ where BUFOBJ is the Python ‘bytes’ representation of the handle and TYPE is a ‘gdb.Type’ for the handle type. d29593 1 a29593 1 One may add arbitrary attributes to ‘gdb.InferiorThread’ objects in d29632 1 a29632 1 Replay::) are available in the ‘gdb’ module: d29638 1 a29638 1 ‘gdb.Record’ object on success. Throw an exception on failure. d29642 3 a29644 2 • ‘"full"’ • ‘"btrace"’: Possible values for FORMAT: ‘"pt"’, ‘"bts"’ or d29648 3 a29650 2 Access a currently running recording. Return a ‘gdb.Record’ object on success. Return ‘None’ if no recording is currently active. d29657 1 a29657 1 A ‘gdb.Record’ object has the following attributes: d29660 2 a29661 2 A string with the current recording method, e.g. ‘full’ or ‘btrace’. d29664 2 a29665 2 A string with the current recording format, e.g. ‘bt’, ‘pts’ or ‘None’. d29676 2 a29677 2 The instruction representing the current replay position. If there is no replay active, this will be ‘None’. d29685 1 a29685 1 A ‘gdb.Record’ object has the following methods: d29690 1 a29690 1 The common ‘gdb.Instruction’ class that recording method specific d29697 1 a29697 1 A ‘memoryview’ object holding the raw instruction data. d29705 1 a29705 1 Additionally ‘gdb.RecordInstruction’ has the following attributes: d29708 2 a29709 2 An integer identifying this instruction. ‘number’ corresponds to the numbers seen in ‘record instruction-history’ (*note Process d29713 2 a29714 2 A ‘gdb.Symtab_and_line’ object representing the associated symtab and line of this instruction. May be ‘None’ if no debug d29722 1 a29722 1 error is represented by a ‘gdb.RecordGap’ object in the instruction d29726 2 a29727 2 An integer identifying this gap. ‘number’ corresponds to the numbers seen in ‘record instruction-history’ (*note Process Record d29731 2 a29732 2 A numerical representation of the reason for the gap. The value is specific to the current recording method. d29737 1 a29737 1 A ‘gdb.RecordFunctionSegment’ object has the following attributes: d29740 3 a29742 3 An integer identifying this function segment. ‘number’ corresponds to the numbers seen in ‘record function-call-history’ (*note Process Record and Replay::). d29745 2 a29746 2 A ‘gdb.Symbol’ object representing the associated symbol. May be ‘None’ if no debug information is available. d29750 1 a29750 1 ‘None’ if the function call is a gap. d29753 1 a29753 1 A list of ‘gdb.RecordInstruction’ or ‘gdb.RecordGap’ objects d29757 1 a29757 1 A ‘gdb.RecordFunctionSegment’ object representing the caller's d29759 2 a29760 2 the function segment to which control returns. If neither the call nor the return have been recorded, this will be ‘None’. d29763 2 a29764 2 A ‘gdb.RecordFunctionSegment’ object representing the previous segment of this function call. May be ‘None’. d29767 2 a29768 2 A ‘gdb.RecordFunctionSegment’ object representing the next segment of this function call. May be ‘None’. d29840 1 a29840 1 implemented using an instance of the ‘gdb.Command’ class, most commonly d29845 3 a29847 3 The object initializer for ‘Command’ registers the new command with GDB. This initializer is normally invoked from the subclass' own ‘__init__’ method. d29856 1 a29856 1 COMMAND_CLASS should be one of the ‘COMMAND_’ constants defined d29861 1 a29861 1 one of the ‘COMPLETE_’ constants defined below. This argument d29863 3 a29865 3 given, GDB will attempt to complete using the object's ‘complete’ method (see below); if no such method is found, an error will occur when completion is attempted. d29867 3 a29869 2 PREFIX is an optional argument. If ‘True’, then the new command is a prefix command; sub-commands of this command may be registered. d29874 1 a29874 1 command is not documented." is used. d29879 4 a29882 4 by invoking the ‘dont_repeat’ method at some point in its ‘invoke’ method (normally this is done early in case of exception). This is similar to the user command ‘dont-repeat’, see *note dont-repeat: Define. d29894 2 a29895 2 If this method throws an exception, it is turned into a GDB ‘error’ call. Otherwise, the return value is ignored. d29898 4 a29901 4 ‘gdb.string_to_argv’. This function behaves identically to GDB's internal argument lexer ‘buildargv’. It is recommended to use this for consistency. Arguments are separated by spaces and may be quoted. Example: d29906 1 d29910 2 a29911 2 that is, the and key bindings (*note Completion::), and the ‘complete’ command (*note complete: Help.). d29914 2 a29915 2 complete command line up to the cursor's location, while WORD holds the last word of the command line; this is computed using a d29918 3 a29920 3 The ‘complete’ method can return several values: • If the return value is a sequence, the contents of the sequence are used as the completions. It is up to ‘complete’ d29926 1 a29926 1 • If the return value is one of the ‘COMPLETE_’ constants d29930 1 a29930 1 • All other results are treated as though there were no d29938 1 a29938 1 defined in the ‘gdb’ module: d29940 1 a29940 1 ‘gdb.COMMAND_NONE’ d29944 1 a29944 1 ‘gdb.COMMAND_RUNNING’ d29946 2 a29947 2 ‘start’, ‘step’, and ‘continue’ are in this category. Type ‘help running’ at the GDB prompt to see a list of commands in this d29950 3 a29952 3 ‘gdb.COMMAND_DATA’ The command is related to data or variables. For example, ‘call’, ‘find’, and ‘print’ are in this category. Type ‘help data’ at the d29955 1 a29955 1 ‘gdb.COMMAND_STACK’ d29957 2 a29958 2 ‘backtrace’, ‘frame’, and ‘return’ are in this category. Type ‘help stack’ at the GDB prompt to see a list of commands in this d29961 5 a29965 4 ‘gdb.COMMAND_FILES’ This class is used for file-related commands. For example, ‘file’, ‘list’ and ‘section’ are in this category. Type ‘help files’ at the GDB prompt to see a list of commands in this category. d29967 1 a29967 1 ‘gdb.COMMAND_SUPPORT’ d29970 2 a29971 2 not related to the state of the inferior. For example, ‘help’, ‘make’, and ‘shell’ are in this category. Type ‘help support’ at d29974 4 a29977 4 ‘gdb.COMMAND_STATUS’ The command is an ‘info’-related command, that is, related to the state of GDB itself. For example, ‘info’, ‘macro’, and ‘show’ are in this category. Type ‘help status’ at the GDB prompt to see a d29980 4 a29983 4 ‘gdb.COMMAND_BREAKPOINTS’ The command has to do with breakpoints. For example, ‘break’, ‘clear’, and ‘delete’ are in this category. Type ‘help breakpoints’ at the GDB prompt to see a list of commands in this d29986 4 a29989 4 ‘gdb.COMMAND_TRACEPOINTS’ The command has to do with tracepoints. For example, ‘trace’, ‘actions’, and ‘tfind’ are in this category. Type ‘help tracepoints’ at the GDB prompt to see a list of commands in this d29992 1 a29992 1 ‘gdb.COMMAND_TUI’ d29994 2 a29995 2 Type ‘help tui’ at the GDB prompt to see a list of commands in this category. d29997 1 a29997 1 ‘gdb.COMMAND_USER’ d29999 2 a30000 2 typically does not fit in one of the other categories. Type ‘help user-defined’ at the GDB prompt to see a list of commands in this d30003 1 a30003 1 ‘gdb.COMMAND_OBSCURE’ d30005 8 a30012 8 general interest to users. For example, ‘checkpoint’, ‘fork’, and ‘stop’ are in this category. Type ‘help obscure’ at the GDB prompt to see a list of commands in this category. ‘gdb.COMMAND_MAINTENANCE’ The command is only useful to GDB maintainers. The ‘maintenance’ and ‘flushregs’ commands are in this category. Type ‘help internals’ at the GDB prompt to see a list of commands in this d30016 3 a30018 3 specifying it via an argument at initialization, or by returning it from the ‘complete’ method. These predefined completion constants are all defined in the ‘gdb’ module: d30020 1 a30020 1 ‘gdb.COMPLETE_NONE’ d30023 1 a30023 1 ‘gdb.COMPLETE_FILENAME’ d30026 3 a30028 3 ‘gdb.COMPLETE_LOCATION’ This constant means that location completion should be done. *Note Location Specifications::. d30030 1 a30030 1 ‘gdb.COMPLETE_COMMAND’ d30034 1 a30034 1 ‘gdb.COMPLETE_SYMBOL’ d30038 1 a30038 1 ‘gdb.COMPLETE_EXPRESSION’ d30059 1 a30059 1 is read into GDB, you may need to import the ‘gdb’ module explicitly. d30069 1 a30069 1 ‘gdb.MICommand’ class, most commonly using a subclass. d30072 1 a30072 1 The object initializer for ‘MICommand’ registers the new command d30074 1 a30074 1 own ‘__init__’ method. d30077 1 a30077 1 GDB/MI command, and in particular must start with a hyphen (‘-’). d30079 3 a30081 3 ‘RuntimeError’ will be raised. Using the name of an GDB/MI command previously defined in Python is allowed, the previous command will be replaced with the new command. d30086 3 a30088 3 ARGUMENTS is a list of strings. Note, that ‘--thread’ and ‘--frame’ arguments are handled by GDB itself therefore they do not show up in ‘arguments’. d30090 2 a30091 2 If this method raises an exception, then it is turned into a GDB/MI ‘^error’ response. Only ‘gdb.GdbError’ exceptions (or its d30093 1 a30093 1 other exception type is treated as a failure of the ‘invoke’ d30095 2 a30096 2 according to the ‘set python print-stack’ setting (*note ‘set python print-stack’: set_python_print_stack.). d30098 2 a30099 2 If this method returns ‘None’, then the GDB/MI command will return a ‘^done’ response with no additional values. d30104 3 a30106 3 VARIABLE names in the RESULT-RECORD, these strings must comply with the naming rules detailed below. The values of this dictionary are recursively handled as follows: d30108 1 a30108 1 • If the value is Python sequence or iterator, it is converted d30111 1 a30111 1 • If the value is Python dictionary, it is converted to GDB/MI d30116 2 a30117 2 • Otherwise, value is first converted to a Python string using ‘str ()’ and then converted to GDB/MI CONST. d30121 1 a30121 1 character long, the first character must be in the set ‘[a-zA-Z]’, d30123 1 a30123 1 ‘[-_a-zA-Z0-9]’. d30125 1 a30125 1 An instance of ‘MICommand’ has the following attributes: d30129 1 a30129 1 ‘__init__’ method. This attribute is read-only. d30135 1 a30135 1 will be ‘True’. d30139 1 a30139 1 be ‘False’. d30141 1 a30141 1 This attribute is read-write, setting this attribute to ‘False’ d30143 1 a30143 1 commands. Setting this attribute to ‘True’ will install the d30172 2 a30173 2 three new GDB/MI commands ‘-echo-dict’, ‘-echo-list’, and ‘-echo-string’. Each time a subclass of ‘gdb.MICommand’ is d30177 1 a30177 1 import the ‘gdb’ module explicitly. d30179 2 a30180 2 The following example shows a GDB session in which the above commands have been added: d30195 1 a30195 1 string. This is done with the ‘gdb.execute_mi’ function. d30226 1 a30226 1 ‘gdb.notify_mi’ function to do that. d30231 3 a30233 3 (‘-’). DATA is any additional data to be emitted with the notification, passed as a Python dictionary. This argument is optional. The dictionary is converted to a GDB/MI RESULT records d30237 1 a30237 1 If DATA is ‘None’ then no additional values are emitted. d30240 2 a30241 2 Records::) with ‘gdb.notify_mi’ is allowed, users are encouraged to prefix user-defined notification with a hyphen (‘-’) to avoid possible d30244 1 a30244 1 Here is how to emit ‘=-connection-removed’ whenever a connection to d30266 1 a30266 1 implemented as an instance of the ‘gdb.Parameter’ class. d30268 2 a30269 2 Parameters are exposed to the user via the ‘set’ and ‘show’ commands. *Note Help::. d30272 1 a30272 1 Two examples are: ‘set follow fork’ and ‘set charset’. Setting these d30279 1 a30279 1 The object initializer for ‘Parameter’ registers the new parameter d30281 1 a30281 1 own ‘__init__’ method. d30285 2 a30286 2 parameters. An example of this can be illustrated with the ‘set print’ set of parameters. If NAME is ‘print foo’, then ‘print’ d30288 1 a30288 1 parameter can subsequently be accessed in GDB as ‘set print foo’. d30293 1 a30293 1 COMMAND_CLASS should be one of the ‘COMMAND_’ constants (*note CLI d30297 3 a30299 3 PARAMETER_CLASS should be one of the ‘PARAM_’ constants defined below. This argument tells GDB the type of the new parameter; this information is used for input validation and completion. d30301 1 a30301 1 If PARAMETER_CLASS is ‘PARAM_ENUM’, then ENUM_SEQUENCE must be a d30305 1 a30305 1 If PARAMETER_CLASS is not ‘PARAM_ENUM’, then the presence of a d30312 1 a30312 1 ‘help set’ and ‘help show’ commands, and should be written taking d30317 1 a30317 1 as the first part of the help text for this parameter's ‘set’ d30321 1 a30321 1 The value of ‘set_doc’ should give a brief summary specific to the d30323 1 a30323 1 ‘help set’ command for this parameter. The class documentation d30325 2 a30326 2 does, this text is displayed for both the ‘help set’ and ‘help show’ commands. d30328 1 a30328 1 The ‘set_doc’ value is examined when ‘Parameter.__init__’ is d30333 1 a30333 1 as the first part of the help text for this parameter's ‘show’ d30337 3 a30339 3 The value of ‘show_doc’ should give a brief summary specific to the show action, this text is only displayed when the user runs the ‘help show’ command for this parameter. The class documentation d30341 2 a30342 2 does, this text is displayed for both the ‘help set’ and ‘help show’ commands. d30344 1 a30344 1 The ‘show_doc’ value is examined when ‘Parameter.__init__’ is d30348 1 a30348 1 The ‘value’ attribute holds the underlying value of the parameter. d30352 1 a30352 1 There are two methods that may be implemented in any ‘Parameter’ d30357 12 a30368 11 has been changed via the ‘set’ API (for example, ‘set foo off’). The ‘value’ attribute has already been populated with the new value and may be used in output. This method must return a string. If the returned string is not empty, GDB will present it to the user. If this method raises the ‘gdb.GdbError’ exception (*note Exception Handling::), then GDB will print the exception's string and the ‘set’ command will fail. Note, however, that the ‘value’ attribute will not be reset in this case. So, if your parameter must validate values, it should store the old value internally and reset the exposed value, like so: d30387 2 a30388 2 GDB will call this method when a PARAMETER's ‘show’ API has been invoked (for example, ‘show foo’). The argument ‘svalue’ receives d30393 1 a30393 1 available types are represented by constants defined in the ‘gdb’ d30396 3 a30398 3 ‘gdb.PARAM_BOOLEAN’ The value is a plain boolean. The Python boolean values, ‘True’ and ‘False’ are the only valid values. d30400 2 a30401 2 ‘gdb.PARAM_AUTO_BOOLEAN’ The value has three possible states: true, false, and ‘auto’. In d30403 1 a30403 1 ‘auto’ is represented using ‘None’. d30405 3 a30407 3 ‘gdb.PARAM_UINTEGER’ The value is an unsigned integer. The value of ‘None’ should be interpreted to mean "unlimited" (literal ‘'unlimited'’ can also be d30411 3 a30413 3 ‘gdb.PARAM_INTEGER’ The value is a signed integer. The value of ‘None’ should be interpreted to mean "unlimited" (literal ‘'unlimited'’ can also be d30417 1 a30417 1 ‘gdb.PARAM_STRING’ d30419 1 a30419 1 escape sequences, such as ‘\t’, ‘\f’, and octal escapes, are d30423 1 a30423 1 ‘gdb.PARAM_STRING_NOESCAPE’ d30427 2 a30428 2 ‘gdb.PARAM_OPTIONAL_FILENAME’ The value is a either a filename (a string), or ‘None’. d30430 1 a30430 1 ‘gdb.PARAM_FILENAME’ d30432 1 a30432 1 ‘PARAM_STRING_NOESCAPE’, but uses file names for completion. d30434 12 a30445 12 ‘gdb.PARAM_ZINTEGER’ The value is a signed integer. This is like ‘PARAM_INTEGER’, except that 0 is allowed and the value of ‘None’ is not supported. ‘gdb.PARAM_ZUINTEGER’ The value is an unsigned integer. This is like ‘PARAM_UINTEGER’, except that 0 is allowed and the value of ‘None’ is not supported. ‘gdb.PARAM_ZUINTEGER_UNLIMITED’ The value is a signed integer. This is like ‘PARAM_INTEGER’ including that the value of ‘None’ should be interpreted to mean "unlimited" (literal ‘'unlimited'’ can also be used to set that d30450 1 a30450 1 ‘gdb.PARAM_ENUM’ d30462 1 a30462 1 class ‘gdb.Function’. d30465 5 a30469 4 The initializer for ‘Function’ registers the new function with GDB. The argument NAME is the name of the function, a string. The function will be visible to the user as a convenience variable of type ‘internal function’, whose name is the same as the given NAME. d30476 6 a30481 6 converted to instances of ‘gdb.Value’, and then the function's ‘invoke’ method is called. Note that GDB does not predetermine the arity of convenience functions. Instead, all available arguments are passed to ‘invoke’, following the standard Python calling convention. In particular, a convenience function can have default values for parameters without ill effect. d30485 1 a30485 1 is converted to a ‘gdb.Value’ following the usual rules. d30503 3 a30505 2 registration of the function with GDB. Depending on how the Python code is read into GDB, you may need to import the ‘gdb’ module explicitly. d30518 1 a30518 1 A program space, or “progspace”, represents a symbolic view of an d30520 2 a30521 2 *Note Objfiles In Python::. *Note program spaces: Inferiors Connections and Programs, for more details about program spaces. d30523 1 a30523 1 The following progspace-related functions are available in the ‘gdb’ d30529 1 a30529 1 identical to ‘gdb.selected_inferior().progspace’ (*note Inferiors d30535 1 a30535 1 Each progspace is represented by an instance of the ‘gdb.Progspace’ d30541 1 a30541 1 argument to the ‘symbol-file’ or ‘file’ commands. d30544 1 a30544 1 attribute will be ‘None’. d30547 3 a30549 3 The ‘gdb.Objfile’ representing the main symbol file (from which debug symbols have been loaded) for the ‘gdb.Progspace’. This is the symbol file set by the ‘symbol-file’ or ‘file’ commands. d30551 2 a30552 2 This will be the ‘gdb.Objfile’ representing ‘Progspace.filename’ when ‘Progspace.filename’ is not ‘None’. d30555 1 a30555 1 attribute will be ‘None’. d30557 3 a30559 3 If the ‘Progspace’ is invalid, i.e., when ‘Progspace.is_valid()’ returns ‘False’, then attempting to access this attribute will raise a ‘RuntimeError’ exception. d30565 2 a30566 2 The file name within this attribute is updated by the ‘exec-file’ and ‘file’ commands. d30568 2 a30569 2 If no executable is currently set within this ‘Progspace’ then this attribute contains ‘None’. d30571 3 a30573 3 If the ‘Progspace’ is invalid, i.e., when ‘Progspace.is_valid()’ returns ‘False’, then attempting to access this attribute will raise a ‘RuntimeError’ exception. d30576 3 a30578 3 The ‘pretty_printers’ attribute is a list of functions. It is used to look up pretty-printers. A ‘Value’ is passed to each function in order; if the function returns ‘None’, then the search d30584 1 a30584 1 The ‘type_printers’ attribute is a list of type printer objects. d30588 1 a30588 1 The ‘frame_filters’ attribute is a dictionary of frame filter d30592 1 a30592 1 The ‘missing_debug_handlers’ attribute is a list of the missing d30599 3 a30601 3 Return the innermost ‘gdb.Block’ containing the given PC value. If the block cannot be found for the PC value specified, the function will return ‘None’. d30604 5 a30608 5 Return the ‘gdb.Symtab_and_line’ object corresponding to the PC value. *Note Symbol Tables In Python::. If an invalid value of PC is passed as an argument, then the ‘symtab’ and ‘line’ attributes of the returned ‘gdb.Symtab_and_line’ object will be ‘None’ and 0 respectively. d30611 2 a30612 2 Returns ‘True’ if the ‘gdb.Progspace’ object is valid, ‘False’ if not. A ‘gdb.Progspace’ object can become invalid if the program d30614 1 a30614 1 other ‘gdb.Progspace’ methods will throw an exception if it is d30623 1 a30623 1 a string, or ‘None’. d30626 2 a30627 2 Return the ‘gdb.Objfile’ holding the given address, or ‘None’ if no objfile covers it. d30629 1 a30629 1 One may add arbitrary attributes to ‘gdb.Progspace’ objects in the d30636 2 a30637 2 In this contrived example, we want to perform some processing when an objfile with a certain symbol is loaded, but we only want to do this d30681 3 a30683 3 libraries used by the inferior, and any separate debug info files (*note Separate Debug Files::). GDB calls these symbol-containing files “objfiles”. d30685 1 a30685 1 The following objfile-related functions are available in the ‘gdb’ d30692 1 a30692 1 objfile, this function returns ‘None’. d30696 1 a30696 1 space. *Note Objfiles In Python::, and *note Progspaces In d30698 1 a30698 1 ‘gdb.selected_inferior().progspace.objfiles()’ and is included for d30704 1 a30704 1 objfile is not found throw the Python ‘ValueError’ exception. d30706 12 a30717 12 If NAME is a relative file name, then it will match any source file name with the same trailing components. For example, if NAME is ‘gcc/expr.c’, then it will match source file name of ‘/build/trunk/gcc/expr.c’, but not ‘/build/trunk/libcpp/expr.c’ or ‘/build/trunk/gcc/x-expr.c’. If BY_BUILD_ID is provided and is ‘True’ then NAME is the build ID of the objfile. Otherwise, NAME is a file name. This is supported only on some operating systems, notably those which use the ELF format for binary files and the GNU Binutils. For more details about this feature, see the description of the ‘--build-id’ command-line option in *note Command Line Options: (ld)Options. d30719 1 a30719 1 Each objfile is represented by an instance of the ‘gdb.Objfile’ d30726 2 a30727 2 The value is ‘None’ if the objfile is no longer valid. See the ‘gdb.Objfile.is_valid’ method, described below. d30732 2 a30733 2 The value is ‘None’ if the objfile is no longer valid. See the ‘gdb.Objfile.is_valid’ method, described below. d30738 1 a30738 1 ‘True’ for file-backed objfiles, and ‘False’ for other kinds. d30742 3 a30744 3 ‘gdb.Objfile’ object that debug info is being provided for. Otherwise this is ‘None’. Separate debug info objfiles are added with the ‘gdb.Objfile.add_separate_debug_file’ method, described d30749 1 a30749 1 have a build ID then the value is ‘None’. d30754 1 a30754 1 ‘--build-id’ command-line option in *note Command Line Options: d30758 1 a30758 1 The containing program space of the objfile as a ‘gdb.Progspace’ d30762 3 a30764 3 The ‘pretty_printers’ attribute is a list of functions. It is used to look up pretty-printers. A ‘Value’ is passed to each function in order; if the function returns ‘None’, then the search d30770 1 a30770 1 The ‘type_printers’ attribute is a list of type printer objects. d30774 1 a30774 1 The ‘frame_filters’ attribute is a dictionary of frame filter d30777 1 a30777 1 One may add arbitrary attributes to ‘gdb.Objfile’ objects in the d30799 1 a30799 1 A ‘gdb.Objfile’ object has the following methods: d30802 2 a30803 2 Returns ‘True’ if the ‘gdb.Objfile’ object is valid, ‘False’ if not. A ‘gdb.Objfile’ object can become invalid if the object file d30805 1 a30805 1 ‘gdb.Objfile’ methods will throw an exception if it is invalid at d30813 3 a30815 3 (*note Separate Debug Files::), but if the file doesn't live in one of the standard places that GDB searches then this function can be used to add a debug info file from a different place. d30818 6 a30823 6 Search for a global symbol named NAME in this objfile. Optionally, the search scope can be restricted with the DOMAIN argument. The DOMAIN argument must be a domain constant defined in the ‘gdb’ module and described in *note Symbols In Python::. This function is similar to ‘gdb.lookup_global_symbol’, except that the search is limited to this objfile. d30825 1 a30825 1 The result is a ‘gdb.Symbol’ object or ‘None’ if the symbol is not d30829 1 a30829 1 Like ‘Objfile.lookup_global_symbol’, but searches for a global d30839 2 a30840 2 (*note Stack frames: Frames.). The ‘gdb.Frame’ class represents a frame in the stack. A ‘gdb.Frame’ object is only valid while its d30842 1 a30842 1 an invalid frame object, GDB will throw a ‘gdb.error’ exception (*note d30845 1 a30845 1 Two ‘gdb.Frame’ objects can be compared for equality with the ‘==’ d30851 1 a30851 1 The following frame-related functions are available in the ‘gdb’ d30864 1 a30864 1 ‘unwind_stop_reason’ method further down in this section). d30873 1 a30873 1 A ‘gdb.Frame’ object has the following methods: d30876 1 a30876 1 Returns true if the ‘gdb.Frame’ object is valid, false if not. A d30878 1 a30878 1 exist anymore in the inferior. All ‘gdb.Frame’ methods will throw d30882 1 a30882 1 Returns the function name of the frame, or ‘None’ if it can't be d30886 1 a30886 1 Returns the ‘gdb.Architecture’ object corresponding to the frame's d30891 1 a30891 1 ‘gdb.NORMAL_FRAME’ d30894 1 a30894 1 ‘gdb.DUMMY_FRAME’ d30898 1 a30898 1 ‘gdb.INLINE_FRAME’ d30900 1 a30900 1 inlined into a ‘gdb.NORMAL_FRAME’ that is older than this one. d30902 1 a30902 1 ‘gdb.TAILCALL_FRAME’ d30905 1 a30905 1 ‘gdb.SIGTRAMP_FRAME’ d30909 1 a30909 1 ‘gdb.ARCH_FRAME’ d30912 2 a30913 2 ‘gdb.SENTINEL_FRAME’ This is like ‘gdb.NORMAL_FRAME’, but it is only used for the d30919 2 a30920 2 ‘gdb.frame_stop_reason_string’ to convert the value returned by this function to a string. The value can be one of: d30922 1 a30922 1 ‘gdb.FRAME_UNWIND_NO_REASON’ d30925 3 a30927 3 ‘gdb.FRAME_UNWIND_NULL_ID’ The previous frame's analyzer returns an invalid result. This is no longer used by GDB, and is kept only for backward d30930 1 a30930 1 ‘gdb.FRAME_UNWIND_OUTERMOST’ d30933 1 a30933 1 ‘gdb.FRAME_UNWIND_UNAVAILABLE’ d30937 1 a30937 1 ‘gdb.FRAME_UNWIND_INNER_ID’ d30942 1 a30942 1 ‘gdb.FRAME_UNWIND_SAME_ID’ d30949 1 a30949 1 ‘gdb.FRAME_UNWIND_NO_SAVED_PC’ d30953 1 a30953 1 ‘gdb.FRAME_UNWIND_MEMORY_ERROR’ d30957 1 a30957 1 ‘gdb.FRAME_UNWIND_FIRST_ERROR’ d30968 1 d30984 1 a30984 1 frame, return ‘None’. d30988 1 a30988 1 frame, return ‘None’. d30995 1 a30995 1 Return the value of REGISTER in this frame. Returns a ‘Gdb.Value’ d30998 4 a31001 3 1. A string that is the name of a valid register (e.g., ‘'sp'’ or ‘'rax'’). 2. A ‘gdb.RegisterDescriptor’ object (*note Registers In d31003 12 a31014 11 3. A GDB internal, platform specific number. Using these numbers is supported for historic reasons, but is not recommended as future changes to GDB could change the mapping between numbers and the registers they represent, breaking any Python code that uses the platform-specific numbers. The numbers are usually found in the corresponding ‘PLATFORM-tdep.h’ file in the GDB source tree. Using a string to access registers will be slightly slower than the other two methods as GDB must look up the mapping between name and internal register number. If performance is critical consider looking up and caching a ‘gdb.RegisterDescriptor’ object. d31021 2 a31022 2 argument must be a string or a ‘gdb.Symbol’ object; BLOCK must be a ‘gdb.Block’ object. d31035 1 a31035 1 If there is no static link, this method returns ‘None’. d31052 1 a31052 1 represented individually in Python as a ‘gdb.Block’. Blocks rely on d31055 1 a31055 1 A frame has a block. Please see *note Frames In Python::, for a more d31058 2 a31059 2 The outermost block is known as the “global block”. The global block typically holds public global variables and functions. d31061 1 a31061 1 The block nested just inside the global block is the “static block”. d31096 1 a31096 1 A ‘gdb.Block’ is iterable. The iterator returns the symbols (*note d31100 2 a31101 2 across blocks in a symbol table. You can also use Python's “dictionary syntax” to access variables in this block, e.g.: d31105 1 a31105 1 The following block-related functions are available in the ‘gdb’ d31109 4 a31112 4 Return the innermost ‘gdb.Block’ containing the given PC value. If the block cannot be found for the PC value specified, the function will return ‘None’. This is identical to ‘gdb.current_progspace().block_for_pc(pc)’ and is included for d31115 1 a31115 1 A ‘gdb.Block’ object has the following methods: d31118 6 a31123 6 Returns ‘True’ if the ‘gdb.Block’ object is valid, ‘False’ if not. A block object can become invalid if the block it refers to doesn't exist anymore in the inferior. All other ‘gdb.Block’ methods will throw an exception if it is invalid at the time the method is called. The block's validity is also checked during iteration over symbols of the block. d31125 1 a31125 1 A ‘gdb.Block’ object has the following attributes: d31135 2 a31136 2 The name of the block represented as a ‘gdb.Symbol’. If the block is not named, then this attribute holds ‘None’. This attribute is d31146 1 a31146 1 exist, this attribute holds ‘None’. This attribute is not d31158 2 a31159 2 ‘True’ if the ‘gdb.Block’ object is a global block, ‘False’ if not. This attribute is not writable. d31162 2 a31163 2 ‘True’ if the ‘gdb.Block’ object is a static block, ‘False’ if not. This attribute is not writable. d31171 3 a31173 3 GDB represents every variable, function and type as an entry in a symbol table. *Note Examining the Symbol Table: Symbols. Similarly, Python represents these symbols in GDB with the ‘gdb.Symbol’ object. d31175 1 a31175 1 The following symbol-related functions are available in the ‘gdb’ d31183 3 a31185 3 NAME is the name of the symbol. It must be a string. The optional BLOCK argument restricts the search to symbols visible in that BLOCK. The BLOCK argument must be a ‘gdb.Block’ object. If d31188 1 a31188 1 DOMAIN argument must be a domain constant defined in the ‘gdb’ d31192 5 a31196 5 ‘gdb.Symbol’ object or ‘None’ if the symbol is not found. If the symbol is found, the second element is ‘True’ if the symbol is a field of a method's object (e.g., ‘this’ in C++), otherwise it is ‘False’. If the symbol is not found, the second element is ‘False’. d31202 3 a31204 3 NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the ‘gdb’ d31207 1 a31207 1 The result is a ‘gdb.Symbol’ object or ‘None’ if the symbol is not d31215 3 a31217 3 NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the ‘gdb’ d31220 1 a31220 1 The result is a ‘gdb.Symbol’ object or ‘None’ if the symbol is not d31224 3 a31226 3 variables. To look up such variables, iterate over the variables of the function's ‘gdb.Block’ and check that ‘block.addr_class’ is ‘gdb.SYMBOL_LOC_STATIC’. d31231 5 a31235 4 is currently stopped, as GDB will first search for matching symbols in the current object file, and then search all other object files. If the application is not yet running then GDB will search all object files in the order they appear in the debug information. d31238 1 a31238 1 Similar to ‘gdb.lookup_static_symbol’, this function searches for d31243 3 a31245 3 NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the ‘gdb’ d31248 1 a31248 1 The result is a list of ‘gdb.Symbol’ objects which could be empty d31252 3 a31254 3 variables. To look up such variables, iterate over the variables of the function's ‘gdb.Block’ and check that ‘block.addr_class’ is ‘gdb.SYMBOL_LOC_STATIC’. d31256 1 a31256 1 A ‘gdb.Symbol’ object has the following attributes: d31259 2 a31260 2 The type of the symbol or ‘None’ if no type is recorded. This attribute is represented as a ‘gdb.Type’ object. *Note Types In d31265 1 a31265 1 represented as a ‘gdb.Symtab’ object. *Note Symbol Tables In d31282 1 a31282 1 either ‘name’ or ‘linkage_name’, depending on whether the user d31288 1 a31288 1 ‘gdb’ module and described later in this chapter. d31291 3 a31293 3 This is ‘True’ if evaluating this symbol's value requires a frame (*note Frames In Python::) and ‘False’ otherwise. Typically, local variables will require a frame, but other symbols will not. d31296 1 a31296 1 ‘True’ if the symbol is an argument of a function. d31299 1 a31299 1 ‘True’ if the symbol is a constant. d31302 1 a31302 1 ‘True’ if the symbol is a function or a method. d31305 2 a31306 2 ‘True’ if the symbol is a variable, as opposed to something like a function or type. Note that this also returns ‘False’ for d31309 1 a31309 1 A ‘gdb.Symbol’ object has the following methods: d31312 5 a31316 5 Returns ‘True’ if the ‘gdb.Symbol’ object is valid, ‘False’ if not. A ‘gdb.Symbol’ object can become invalid if the symbol it refers to does not exist in GDB any longer. All other ‘gdb.Symbol’ methods will throw an exception if it is invalid at the time the method is called. d31319 1 a31319 1 Compute the value of the symbol, as a ‘gdb.Value’. For functions, d31325 2 a31326 2 The available domain categories in ‘gdb.Symbol’ are represented as constants in the ‘gdb’ module: d31328 1 a31328 1 ‘gdb.SYMBOL_UNDEF_DOMAIN’ d31330 2 a31331 2 following domains apply. This usually indicates an error either in the symbol information or in GDB's handling of symbols. d31333 1 a31333 1 ‘gdb.SYMBOL_VAR_DOMAIN’ d31336 1 a31336 1 ‘gdb.SYMBOL_FUNCTION_DOMAIN’ d31339 1 a31339 1 ‘gdb.SYMBOL_TYPE_DOMAIN’ d31341 3 a31343 3 tag (the name appearing after a ‘struct’, ‘union’, or ‘enum’ keyword) will not appear here; in other languages, all types are in this domain. d31345 1 a31345 1 ‘gdb.SYMBOL_STRUCT_DOMAIN’ d31350 2 a31351 2 Here ‘type_one’ will be in ‘SYMBOL_STRUCT_DOMAIN’, but ‘type_two’ will be in ‘SYMBOL_TYPE_DOMAIN’. d31353 1 a31353 1 ‘gdb.SYMBOL_LABEL_DOMAIN’ d31356 1 a31356 1 ‘gdb.SYMBOL_MODULE_DOMAIN’ d31359 1 a31359 1 ‘gdb.SYMBOL_COMMON_BLOCK_DOMAIN’ d31367 3 a31369 3 each named after one of the preceding constants, but with the ‘SEARCH’ prefix replacing the ‘SYMBOL’ prefix; for example, ‘SEARCH_LABEL_DOMAIN’. These may be or'd together to form a search d31374 2 a31375 2 The available address class categories in ‘gdb.Symbol’ are represented as constants in the ‘gdb’ module: d31377 1 a31377 1 ‘gdb.SYMBOL_LOC_UNDEF’ d31381 1 a31381 1 ‘gdb.SYMBOL_LOC_CONST’ d31384 1 a31384 1 ‘gdb.SYMBOL_LOC_STATIC’ d31387 1 a31387 1 ‘gdb.SYMBOL_LOC_REGISTER’ d31390 1 a31390 1 ‘gdb.SYMBOL_LOC_ARG’ d31394 1 a31394 1 ‘gdb.SYMBOL_LOC_REF_ARG’ d31396 1 a31396 1 ‘LOC_ARG’ except that the value's address is stored at the offset, d31399 4 a31402 4 ‘gdb.SYMBOL_LOC_REGPARM_ADDR’ Value is a specified register. Just like ‘LOC_REGISTER’ except the register holds the address of the argument instead of the argument itself. d31404 1 a31404 1 ‘gdb.SYMBOL_LOC_LOCAL’ d31407 2 a31408 2 ‘gdb.SYMBOL_LOC_TYPEDEF’ Value not used. Symbols in the domain ‘SYMBOL_STRUCT_DOMAIN’ all d31411 1 a31411 1 ‘gdb.SYMBOL_LOC_LABEL’ d31414 1 a31414 1 ‘gdb.SYMBOL_LOC_BLOCK’ d31417 1 a31417 1 ‘gdb.SYMBOL_LOC_CONST_BYTES’ d31420 4 a31423 4 ‘gdb.SYMBOL_LOC_UNRESOLVED’ Value is at a fixed address, but the address of the variable has to be determined from the minimal symbol table whenever the variable is referenced. d31425 1 a31425 1 ‘gdb.SYMBOL_LOC_OPTIMIZED_OUT’ d31428 1 a31428 1 ‘gdb.SYMBOL_LOC_COMPUTED’ d31431 1 a31431 1 ‘gdb.SYMBOL_LOC_COMMON_BLOCK’ d31441 4 a31444 4 Access to symbol table data maintained by GDB on the inferior is exposed to Python via two objects: ‘gdb.Symtab_and_line’ and ‘gdb.Symtab’. Symbol table and line data for a frame is returned from the ‘find_sal’ method in ‘gdb.Frame’ object. *Note Frames In Python::. d31446 1 a31446 1 For more information on GDB's symbol table management, see *note d31449 1 a31449 1 A ‘gdb.Symtab_and_line’ object has the following attributes: d31452 1 a31452 1 The symbol table object (‘gdb.Symtab’) for this frame. This d31467 1 a31467 1 A ‘gdb.Symtab_and_line’ object has the following methods: d31470 2 a31471 2 Returns ‘True’ if the ‘gdb.Symtab_and_line’ object is valid, ‘False’ if not. A ‘gdb.Symtab_and_line’ object can become invalid d31473 3 a31475 2 GDB any longer. All other ‘gdb.Symtab_and_line’ methods will throw an exception if it is invalid at the time the method is called. d31477 1 a31477 1 A ‘gdb.Symtab’ object has the following attributes: d31489 3 a31491 3 the code in the symbol table. The contents of this string is up to the compiler. If no producer information is available then ‘None’ is returned. This attribute is not writable. d31493 1 a31493 1 A ‘gdb.Symtab’ object has the following methods: d31496 5 a31500 5 Returns ‘True’ if the ‘gdb.Symtab’ object is valid, ‘False’ if not. A ‘gdb.Symtab’ object can become invalid if the symbol table it refers to does not exist in GDB any longer. All other ‘gdb.Symtab’ methods will throw an exception if it is invalid at the time the method is called. d31514 2 a31515 2 Return the line table associated with the symbol table. *Note Line Tables In Python::. d31523 10 a31532 9 Python code can request and inspect line table information from a symbol table that is loaded in GDB. A line table is a mapping of source lines to their executable locations in memory. To acquire the line table information for a particular symbol table, use the ‘linetable’ function (*note Symbol Tables In Python::). A ‘gdb.LineTable’ is iterable. The iterator returns ‘LineTableEntry’ objects that correspond to the source line and address for each line table entry. ‘LineTableEntry’ objects have the following attributes: d31545 4 a31548 4 receive multiple ‘LineTableEntry’ objects with matching ‘line’ attributes, but with different ‘pc’ attributes. The iterator is sorted in ascending ‘pc’ order. Here is a small example illustrating iterating over a line table. d31566 1 a31566 1 In addition to being able to iterate over a ‘LineTable’, it also has d31570 4 a31573 4 Return a Python ‘Tuple’ of ‘LineTableEntry’ objects for any entries in the line table for the given LINE, which specifies the source code line. If there are no entries for that source code LINE, the Python ‘None’ is returned. d31576 3 a31578 3 Return a Python ‘Boolean’ indicating whether there is an entry in the line table for this source line. Return ‘True’ if an entry is found, or ‘False’ if not. d31581 1 a31581 1 Return a Python ‘List’ of the source line numbers in the symbol d31583 2 a31584 2 The contents of the ‘List’ will just be the source line entries represented as Python ‘Long’ values. d31592 1 a31592 1 Python code can manipulate breakpoints via the ‘gdb.Breakpoint’ class. d31595 3 a31597 3 ‘gdb.Breakpoint’ constructor. The first one accepts a string like one would pass to the ‘break’ (*note Setting Breakpoints: Set Breaks.) and ‘watch’ (*note Setting Watchpoints: Set Watchpoints.) commands, and can d31599 2 a31600 2 separate Python arguments similar to *note Explicit Locations::, and can only be used to create breakpoints. d31604 5 a31608 5 Create a new breakpoint according to SPEC, which is a string naming the location of a breakpoint, or an expression that defines a watchpoint. The string should describe a location in a format recognized by the ‘break’ command (*note Setting Breakpoints: Set Breaks.) or, in the case of a watchpoint, by the ‘watch’ command d31615 2 a31616 2 create, if TYPE is ‘gdb.BP_WATCHPOINT’. If WP_CLASS is omitted, it defaults to ‘gdb.WP_WRITE’. d31620 2 a31621 2 when created, nor will it be listed in the output from ‘info breakpoints’ (but will be listed with the ‘maint info breakpoints’ d31625 4 a31628 4 breakpoint. Temporary breakpoints are deleted after they have been hit. Any further access to the Python breakpoint after it has been hit will result in a runtime error (as that breakpoint has now been automatically deleted). d31631 4 a31634 3 interpreting the function passed in ‘spec’ as a fully-qualified name. It is equivalent to ‘break’'s ‘-qualified’ flag (*note Linespec Locations:: and *note Explicit Locations::). d31639 3 a31641 3 explicit location (*note Explicit Locations::) using keywords. The new breakpoint will be created in the specified source file SOURCE, at the specified FUNCTION, LABEL and LINE. d31646 1 a31646 1 The available types are represented by constants defined in the ‘gdb’ d31649 1 a31649 1 ‘gdb.BP_BREAKPOINT’ d31652 1 a31652 1 ‘gdb.BP_HARDWARE_BREAKPOINT’ d31655 1 a31655 1 ‘gdb.BP_WATCHPOINT’ d31658 1 a31658 1 ‘gdb.BP_HARDWARE_WATCHPOINT’ d31661 1 a31661 1 ‘gdb.BP_READ_WATCHPOINT’ d31664 1 a31664 1 ‘gdb.BP_ACCESS_WATCHPOINT’ d31667 1 a31667 1 ‘gdb.BP_CATCHPOINT’ d31669 2 a31670 2 ‘gdb.Breakpoint’ objects, but will be present in ‘gdb.Breakpoint’ objects reported from ‘gdb.BreakpointEvent’s (*note Events In d31674 1 a31674 1 in the ‘gdb’ module: d31676 1 a31676 1 ‘gdb.WP_READ’ d31679 1 a31679 1 ‘gdb.WP_WRITE’ d31682 1 a31682 1 ‘gdb.WP_ACCESS’ d31686 3 a31688 3 The ‘gdb.Breakpoint’ class can be sub-classed and, in particular, you may choose to implement the ‘stop’ method. If this method is defined in a sub-class of ‘gdb.Breakpoint’, it will be called when d31690 1 a31690 1 instantiates that sub-class. If the method returns ‘True’, the d31695 2 a31696 2 ‘stop’ method, each one will be called regardless of the return status of the previous. This ensures that all ‘stop’ methods have d31698 1 a31698 1 the methods returns ‘True’ but the others return ‘False’, the d31704 2 a31705 2 As a general rule, you should not alter any data within GDB or the inferior at this time. d31707 1 a31707 1 Example ‘stop’ implementation: d31717 6 a31722 6 Return ‘True’ if this ‘Breakpoint’ object is valid, ‘False’ otherwise. A ‘Breakpoint’ object can become invalid if the user deletes the breakpoint. In this case, the object still exists, but the underlying breakpoint does not. In the cases of watchpoint scope, the watchpoint remains valid even if execution of the inferior leaves the scope of that watchpoint. d31726 1 a31726 1 Python ‘Breakpoint’ object. Any further access to this object's d31730 1 a31730 1 This attribute is ‘True’ if the breakpoint is enabled, and ‘False’ d31735 1 a31735 1 This attribute is ‘True’ if the breakpoint is silent, and ‘False’ d31739 2 a31740 2 the first command is ‘silent’. This is not reported by the ‘silent’ attribute. d31743 1 a31743 1 This attribute is ‘True’ if the breakpoint is pending, and ‘False’ d31749 1 a31749 1 the breakpoint is not thread-specific, this attribute is ‘None’. d31752 2 a31753 2 Only one of ‘Breakpoint.thread’ or ‘Breakpoint.inferior’ can be set to a valid id at any time, that is, a breakpoint can be thread d31759 1 a31759 1 breakpoint is not inferior-specific, this attribute is ‘None’. d31762 1 a31762 1 ‘gdb.BP_BREAKPOINT’ and ‘gdb.BP_HARDWARE_BREAKPOINT’. d31767 1 a31767 1 underlying language is not Ada), this attribute is ‘None’. This d31775 3 a31777 3 This attribute holds the breakpoint's number -- the identifier used by the user to manipulate the breakpoint. This attribute is not writable. d31786 1 a31786 1 when set, or when the ‘info breakpoints’ command is run. This d31794 1 a31794 1 ‘is_valid’ function, will result in an error after the breakpoint d31807 1 a31807 1 ‘None’. This attribute is not writable. d31810 7 a31816 7 Get the most current list of breakpoint locations that are inserted for this breakpoint, with elements of type ‘gdb.BreakpointLocation’ (described below). This functionality matches that of the ‘info breakpoint’ command (*note Set Breaks::), in that it only retrieves the most current list of locations, thus the list itself when returned is not updated behind the scenes. This attribute is not writable. d31822 1 a31822 1 value is ‘None’. This attribute is not writable. d31827 1 a31827 1 attribute's value is ‘None’. This attribute is writable. d31833 1 a31833 1 this attribute is ‘None’. This attribute is writable. d31838 10 a31847 10 A breakpoint location is one of the actual places where a breakpoint has been set, represented in the Python API by the ‘gdb.BreakpointLocation’ type. This type is never instantiated by the user directly, but is retrieved from ‘Breakpoint.locations’ which returns a list of breakpoint locations where it is currently set. Breakpoint locations can become invalid if new symbol files are loaded or dynamically loaded libraries are closed. Accessing the attributes of an invalidated breakpoint location will throw a ‘RuntimeError’ exception. Access the ‘Breakpoint.locations’ attribute again to retrieve the new and valid breakpoints location list. d31851 1 a31851 1 this location was set. The type of the attribute is a tuple of d31854 2 a31855 2 catchpoints. This will throw a ‘RuntimeError’ exception if the location has been invalidated. This attribute is not writable. d31859 1 a31859 1 This attribute is of type long. This will throw a ‘RuntimeError’ d31866 1 a31866 1 ‘RuntimeError’ exception if the location has been invalidated. d31869 3 a31871 3 This attribute holds a reference to the ‘gdb.Breakpoint’ owner object, from which this ‘gdb.BreakpointLocation’ was retrieved from. This will throw a ‘RuntimeError’ exception if the location d31877 2 a31878 2 ‘None’. This will throw a ‘RuntimeError’ exception if the location has been invalidated. This attribute is not writable. d31882 3 a31884 3 If no full name could be found, this attribute returns ‘None’. This will throw a ‘RuntimeError’ exception if the location has been invalidated. This attribute is not writable. d31888 1 a31888 1 ‘List’ of the thread group ID's. This will throw a ‘RuntimeError’ d31899 2 a31900 2 of a frame, based on the ‘finish’ command. ‘gdb.FinishBreakpoint’ extends ‘gdb.Breakpoint’. The underlying breakpoint will be disabled d31902 1 a31902 1 (i.e. ‘Breakpoint.stop’ or ‘FinishBreakpoint.out_of_scope’ triggered). d31907 1 a31907 1 Create a finish breakpoint at the return address of the ‘gdb.Frame’ d31909 3 a31911 3 newest frame. The optional INTERNAL argument allows the breakpoint to become invisible to the user. *Note Breakpoints In Python::, for further details about this argument. d31914 4 a31917 4 In some circumstances (e.g. ‘longjmp’, C++ exceptions, GDB ‘return’ command, ...), a function may not properly terminate, and thus never hit the finish breakpoint. When GDB notices such a situation, the ‘out_of_scope’ callback will be triggered. d31919 1 a31919 1 You may want to sub-class ‘gdb.FinishBreakpoint’ and override this d31932 4 a31935 4 build the ‘gdb.FinishBreakpoint’ object had debug symbols, this attribute will contain a ‘gdb.Value’ object corresponding to the return value of the function. The value will be ‘None’ if the function return type is ‘void’ or if the return value was not d31944 1 a31944 1 A “lazy string” is a string whose contents is not retrieved or encoded d31947 7 a31953 7 A ‘gdb.LazyString’ is represented in GDB as an ‘address’ that points to a region of memory, an ‘encoding’ that will be used to encode that region of memory, and a ‘length’ to delimit the region of memory that represents the string. The difference between a ‘gdb.LazyString’ and a string wrapped within a ‘gdb.Value’ is that a ‘gdb.LazyString’ will be treated differently by GDB when printing. A ‘gdb.LazyString’ is retrieved and encoded during printing, while a ‘gdb.Value’ wrapping a d31956 1 a31956 1 A ‘gdb.LazyString’ object has the following functions: d31959 1 a31959 1 Convert the ‘gdb.LazyString’ to a ‘gdb.Value’. This value will d31962 1 a31962 1 ‘gdb.LazyString’. d31970 2 a31971 2 the length is -1, then the string will be fetched and encoded up to the first null of appropriate width. This attribute is not d31977 3 a31979 3 set, or contains an empty string, then GDB will select the most appropriate encoding when the string is printed. This attribute is not writable. d31984 3 a31986 3 To resolve this to the lazy string's character type, use the type's ‘target’ method. *Note Types In Python::. This attribute is not writable. d31995 2 a31996 2 its various computations. An architecture is represented by an instance of the ‘gdb.Architecture’ class. d31998 1 a31998 1 A ‘gdb.Architecture’ class has the following methods: d32006 13 a32018 13 determine the number of instructions in the returned list. If both the optional arguments END_PC and COUNT are specified, then a list of at most COUNT disassembled instructions whose start address falls in the closed memory address interval from START_PC to END_PC are returned. If END_PC is not specified, but COUNT is specified, then COUNT number of instructions starting from the address START_PC are returned. If COUNT is not specified but END_PC is specified, then all instructions whose start address falls in the closed memory address interval from START_PC to END_PC are returned. If neither END_PC nor COUNT are specified, then a single instruction at START_PC is returned. For all of these cases, each element of the returned list is a Python ‘dict’ with the following string keys: d32020 1 a32020 1 ‘addr’ d32024 1 a32024 1 ‘asm’ d32028 1 a32028 1 specified by the current CLI variable ‘disassembly-flavor’. d32031 1 a32031 1 ‘length’ d32035 1 d32044 2 a32045 2 If SIGNED is not specified, it defaults to ‘True’. If SIGNED is ‘False’, the returned type will be unsigned. d32048 1 a32048 1 ‘ValueError’ exception. d32051 1 a32051 1 Return a ‘gdb.RegisterDescriptorIterator’ (*note Registers In d32054 1 a32054 1 empty string, then the register group ‘all’ is assumed. d32057 3 a32059 3 Return a ‘gdb.RegisterGroupsIterator’ (*note Registers In Python::) for all of the register groups available for the ‘gdb.Architecture’. d32067 10 a32076 10 Python code can request from a ‘gdb.Architecture’ information about the set of registers available (*note ‘Architecture.registers’: gdbpy_architecture_registers.). The register information is returned as a ‘gdb.RegisterDescriptorIterator’, which is an iterator that in turn returns ‘gdb.RegisterDescriptor’ objects. A ‘gdb.RegisterDescriptor’ does not provide the value of a register (*note ‘Frame.read_register’: gdbpy_frame_read_register. for reading a register's value), instead the ‘RegisterDescriptor’ is a way to discover which registers are available for a particular architecture. d32078 1 a32078 1 A ‘gdb.RegisterDescriptor’ has the following read-only properties: d32084 1 a32084 1 using the following ‘gdb.RegisterDescriptorIterator’ function: d32088 2 a32089 2 ‘gdb.RegisterDescriptor’ for the register with that name, or ‘None’ if there is no register with that name. d32091 1 a32091 1 Python code can also request from a ‘gdb.Architecture’ information d32093 1 a32093 1 (*note ‘Architecture.register_groups’: gdbpy_architecture_reggroups.). d32100 1 a32100 1 commands like ‘info registers’ (*note ‘info registers REGGROUP’: d32104 2 a32105 2 ‘gdb.RegisterGroupsIterator’, which is an iterator that in turn returns ‘gdb.RegisterGroup’ objects. d32107 1 a32107 1 A ‘gdb.RegisterGroup’ object has the following read-only properties: d32121 2 a32122 2 connection types are ‘native’ and ‘remote’. *Note Inferiors Connections and Programs::. d32125 2 a32126 2 ‘gdb.TargetConnection’, or as one of its sub-classes. To get a list of all connections use ‘gdb.connections’ (*note gdb.connections: d32129 2 a32130 2 To get the connection for a single ‘gdb.Inferior’ read its ‘gdb.Inferior.connection’ attribute (*note gdb.Inferior.connection: d32133 4 a32136 4 Currently there is only a single sub-class of ‘gdb.TargetConnection’, ‘gdb.RemoteTargetConnection’, however, additional sub-classes may be added in future releases of GDB. As a result you should avoid writing code like: d32149 1 a32149 1 A ‘gdb.TargetConnection’ has the following method: d32152 2 a32153 2 Return ‘True’ if the ‘gdb.TargetConnection’ object is valid, ‘False’ if not. A ‘gdb.TargetConnection’ will become invalid if d32158 1 a32158 1 Reading any of the ‘gdb.TargetConnection’ properties will throw an d32161 1 a32161 1 A ‘gdb.TargetConnection’ has the following read-only properties: d32165 2 a32166 2 This is the same value as displayed in the ‘Num’ column of the ‘info connections’ command output (*note info connections: d32172 1 a32172 1 ‘target’ command (*note target command: Target Commands.). d32176 2 a32177 2 is the same string that is displayed in the ‘Description’ column of the ‘info connection’ command output (*note info connections: d32182 1 a32182 1 connection. This attribute can be ‘None’ if there are no d32186 2 a32187 2 is the ‘remote’ connection, in this case the details string can contain the ‘HOSTNAME:PORT’ that was used to connect to the remote d32190 5 a32194 5 The ‘gdb.RemoteTargetConnection’ class is a sub-class of ‘gdb.TargetConnection’, and is used to represent ‘remote’ and ‘extended-remote’ connections. In addition to the attributes and methods available from the ‘gdb.TargetConnection’ base class, a ‘gdb.RemoteTargetConnection’ has the following method: d32198 2 a32199 2 response. The PACKET should either be a ‘bytes’ object, or a ‘Unicode’ string. d32201 3 a32203 3 If PACKET is a ‘Unicode’ string, then the string is encoded to a ‘bytes’ object using the ASCII codec. If the string can't be encoded then an ‘UnicodeError’ is raised. d32205 2 a32206 2 If PACKET is not a ‘bytes’ object, or a ‘Unicode’ string, then a ‘TypeError’ is raised. If PACKET is empty then a ‘ValueError’ is d32209 1 a32209 1 The response is returned as a ‘bytes’ object. If it is known that d32221 2 a32222 2 This is equivalent to the ‘maintenance packet’ command (*note maint packet::). d32240 1 a32240 1 ‘[a-zA-Z][-_.a-zA-Z0-9]*’, it is an error to try and create a d32245 1 a32245 1 ‘gdb.TuiWindow’, described below. It should return an object that d32249 1 a32249 1 an object of type ‘gdb.TuiWindow’. This object has these methods and d32253 1 a32253 1 This method returns ‘True’ when this window is valid. When the d32255 1 a32255 1 layout will be destroyed. At this point, the ‘gdb.TuiWindow’ will d32257 1 a32257 1 ‘is_valid’ will throw an exception. d32259 1 a32259 1 When the TUI is disabled using ‘tui disable’ (*note tui disable: d32261 1 a32261 1 ‘is_valid’ will still return ‘False’ and other methods (and d32283 3 a32285 3 If the FULL_WINDOW parameter is ‘True’, then STRING contains the full contents of the window. This is similar to calling ‘erase’ before ‘write’, but avoids the flickering. d32288 2 a32289 2 conforming to the TUI window protocol. These are the method that can be called on this object, which is referred to below as the "window d32298 2 a32299 2 When the TUI window is closed, the ‘gdb.TuiWindow’ object will be put into an invalid state. At this time, GDB will call ‘close’ d32309 1 a32309 1 layout. When this happens, GDB will call the ‘render’ method on d32314 1 a32314 1 and send output to the ‘gdb.TuiWindow’. d32336 3 a32338 3 When TUI mouse events are disabled by turning off the ‘tui mouse-events’ setting (*note set tui mouse-events: tui-mouse-events.), then ‘click’ will not be called. d32347 2 a32348 2 Python API. The disassembler related features are contained within the ‘gdb.disassembler’ module: d32359 1 a32359 1 description of ‘__init__’ for more details. d32364 2 a32365 2 A read-only integer containing the address at which GDB wishes to disassemble a single instruction. d32368 1 a32368 1 The ‘gdb.Architecture’ (*note Architectures In Python::) for d32373 1 a32373 1 The ‘gdb.Progspace’ (*note Program Spaces In Python: d32378 2 a32379 2 Returns ‘True’ if the ‘DisassembleInfo’ object is valid, ‘False’ if not. A ‘DisassembleInfo’ object will become d32381 3 a32383 3 ‘DisassembleInfo’ was created, has returned. Calling other ‘DisassembleInfo’ methods, or accessing ‘DisassembleInfo’ properties, will raise a ‘RuntimeError’ exception if it is d32387 4 a32390 4 This can be used to create a new ‘DisassembleInfo’ object that is a copy of INFO. The copy will have the same ‘address’, ‘architecture’, and ‘progspace’ values as INFO, and will become invalid at the same time as INFO. d32392 1 a32392 1 This method exists so that sub-classes of ‘DisassembleInfo’ d32394 4 a32397 4 copies of an existing ‘DisassembleInfo’ object, but sub-classes might choose to override the ‘read_memory’ method, and so control what GDB sees when reading from memory (*note builtin_disassemble::). d32402 1 a32402 1 bytes, starting at OFFSET from ‘DisassembleInfo.address’. d32407 2 a32408 2 buffer rather than directly from inferior memory, calling this method handles this detail. d32410 2 a32411 2 Returns a buffer object, which behaves much like an array or a string, just as ‘Inferior.read_memory’ does (*note d32416 1 a32416 1 ‘gdb.MemoryError’ exception is raised (*note Exception d32422 1 a32422 1 important to understand how ‘builtin_disassemble’ makes use of d32427 2 a32428 2 read multiple times. Any single call might only read a subset of the total instruction bytes. d32430 1 a32430 1 If an implementation of ‘read_memory’ is unable to read the d32433 1 a32433 1 ‘gdb.MemoryError’ should be raised. d32435 3 a32437 3 Raising a ‘MemoryError’ inside ‘read_memory’ does not automatically mean a ‘MemoryError’ will be raised by ‘builtin_disassemble’. It is possible the GDB's builtin d32439 1 a32439 1 When ‘read_memory’ raises the ‘MemoryError’ the builtin d32442 1 a32442 1 ‘builtin_disassemble’ will not itself raise a ‘MemoryError’. d32444 2 a32445 2 Any other exception type raised in ‘read_memory’ will propagate back and be re-raised by ‘builtin_disassemble’. d32448 1 a32448 1 Create a new ‘DisassemblerTextPart’ representing a piece of a d32454 1 a32454 1 ‘DisassemblerResult’ in order to represent the styling within d32458 1 a32458 1 Create a new ‘DisassemblerAddressPart’. ADDRESS is the value d32460 1 a32460 1 ‘DisassemblerAddressPart’ is displayed as an absolute address d32464 1 d32474 3 a32476 3 The ‘__call__’ method must be overridden by sub-classes to perform disassembly. Calling ‘__call__’ on this base class will raise a ‘NotImplementedError’ exception. d32478 1 a32478 1 The INFO argument is an instance of ‘DisassembleInfo’, and d32481 1 a32481 1 If this function returns ‘None’, this indicates to GDB that d32486 1 a32486 1 Alternatively, this function can return a ‘DisassemblerResult’ d32490 9 a32498 9 The ‘__call__’ method can raise a ‘gdb.MemoryError’ exception (*note Exception Handling::) to indicate to GDB that there was a problem accessing the required memory, this will then be displayed by GDB within the disassembler output. Ideally, the only three outcomes from invoking ‘__call__’ would be a return of ‘None’, a successful disassembly returned in a ‘DisassemblerResult’, or a ‘MemoryError’ indicating that there was a problem reading memory. d32500 1 a32500 1 However, as an implementation of ‘__call__’ could fail due to d32502 2 a32503 2 disassembly is temporarily unavailable, then, if ‘__call__’ raises a ‘GdbError’, the exception will be converted to a d32507 1 a32507 1 Any other exception type raised by the ‘__call__’ method is d32509 2 a32510 2 printed to the error stream according to the ‘set python print-stack’ setting (*note ‘set python print-stack’: d32516 1 a32516 1 ‘builtin_disassemble’ (*note builtin_disassemble::), and an d32518 1 a32518 1 ‘Disassembler.__call__’ (*note Disassembler Class::) if an d32521 1 a32521 1 It is not possible to sub-class the ‘DisassemblerResult’ class. d32523 1 a32523 1 The ‘DisassemblerResult’ class has the following properties and d32531 12 a32542 11 Only one of STRING or PARTS should be used to initialize a new ‘DisassemblerResult’; the other one should be passed the value ‘None’. Alternatively, the arguments can be passed by name, and the unused argument can be ignored. The STRING argument, if not ‘None’, is a non-empty string that represents the entire disassembled instruction. Building a result object using the STRING argument does not allow for any styling information to be included in the result. GDB will style the result as a single ‘DisassemblerTextPart’ with ‘STYLE_TEXT’ style (*note Disassembler Styling Parts::). d32544 2 a32545 2 The PARTS argument, if not ‘None’, is a non-empty sequence of ‘DisassemblerPart’ objects. Each part represents a small part d32548 2 a32549 2 displayed by GDB with full styling information (*note ‘set style disassembler enabled’: style_disassembler_enabled.). d32563 1 a32563 1 ‘DisassemblerPart’ objects, the STRING property will still be d32565 2 a32566 2 ‘DisassemblerPart.string’ values of each component part (*note Disassembler Styling Parts::). d32570 1 a32570 1 ‘DisassemblerPart’ objects. Each ‘DisassemblerPart’ object d32574 1 a32574 1 ‘set style disassembler enabled’: d32578 1 a32578 1 than with a sequence of ‘DisassemblerPart’ objects, the PARTS d32581 1 a32581 1 ‘DisassemblerTextPart’ object, the string of which will d32583 1 a32583 1 be ‘STYLE_TEXT’. d32591 6 a32596 6 parent class, or any of the sub-classes listed below. Instances of the sub-classes listed below are created by calling ‘builtin_disassemble’ (*note builtin_disassemble::) and are returned within the ‘DisassemblerResult’ object, or can be created by calling the ‘text_part’ and ‘address_part’ methods on the ‘DisassembleInfo’ class (*note DisassembleInfo Class::). d32598 1 a32598 1 The ‘DisassemblerPart’ class has a single property: d32607 1 a32607 1 The ‘DisassemblerTextPart’ class represents a piece of the d32610 1 a32610 1 ‘DisassembleInfo.text_part’ to create a new instance of this class d32614 1 a32614 1 ‘DisassemblerTextPart’ has the following additional property: d32623 1 a32623 1 The ‘DisassemblerAddressPart’ class represents an absolute address d32625 2 a32626 2 ‘DisassemblerAddressPart’ instead of a ‘DisassemblerTextPart’ with ‘STYLE_ADDRESS’ is preferred, GDB will display the address as both d32628 2 a32629 2 next to the address. Using ‘DisassemblerAddressPart’ also ensures that user settings such as ‘set print max-symbolic-offset’ are d32636 4 a32639 4 In this instruction the ‘0x401136 ’ was generated from a single ‘DisassemblerAddressPart’. The ‘0x401136’ will be styled with ‘STYLE_ADDRESS’, and ‘foo’ will be styled with ‘STYLE_SYMBOL’. The ‘<’ and ‘>’ will be styled as ‘STYLE_TEXT’. d32642 1 a32642 1 ‘DisassemblerTextPart’ with style ‘STYLE_ADDRESS’ can be used d32646 1 a32646 1 ‘DisassembleInfo.address_part’ to create a new instance of this d32650 1 a32650 1 ‘DisassemblerAddressPart’ has the following additional property: d32654 1 a32654 1 object's ‘__init__’ method. d32664 1 a32664 1 ‘gdb.disassembler.STYLE_TEXT’ d32666 3 a32668 3 output. This style should be used for any parts of the instruction that don't fit any of the other styles listed below. GDB styles text with this style using its default style. d32670 1 a32670 1 ‘gdb.disassembler.STYLE_MNEMONIC’ d32675 1 a32675 1 GDB styles text with this style using the ‘disassembler mnemonic’ d32678 1 a32678 1 ‘gdb.disassembler.STYLE_SUB_MNEMONIC’ d32682 2 a32683 2 which is disjoint from the primary mnemonic (which will have styled ‘STYLE_MNEMONIC’). d32689 3 a32691 3 The ‘add’ is the primary instruction mnemonic, and would be given style ‘STYLE_MNEMONIC’, while ‘lsl’ is the sub-mnemonic, and would be given the style ‘STYLE_SUB_MNEMONIC’. d32693 1 a32693 1 GDB styles text with this style using the ‘disassembler mnemonic’ d32696 1 a32696 1 ‘gdb.disassembler.STYLE_ASSEMBLER_DIRECTIVE’ d32698 2 a32699 2 In this case the disassembler may choose to represent the result of disassembling using an assembler directive, for example: d32703 2 a32704 2 In this case, the ‘.word’ would be give the ‘STYLE_ASSEMBLER_DIRECTIVE’ style. An assembler directive is d32708 1 a32708 1 GDB styles text with this style using the ‘disassembler mnemonic’ d32711 1 a32711 1 ‘gdb.disassembler.STYLE_REGISTER’ d32715 1 a32715 1 GDB styles text with this style using the ‘disassembler register’ d32718 1 a32718 1 ‘gdb.disassembler.STYLE_ADDRESS’ d32722 3 a32724 3 When creating a ‘DisassemblerTextPart’ with this style, you should consider if a ‘DisassemblerAddressPart’ would be more appropriate. See *note Disassembler Styling Parts:: for a description of what d32727 1 a32727 1 GDB styles text with this style using the ‘disassembler address’ d32730 1 a32730 1 ‘gdb.disassembler.STYLE_ADDRESS_OFFSET’ d32734 2 a32735 2 going to access memory, and the value is being used to offset which address is accessed. d32739 4 a32742 4 instruction also allowed for an immediate offset to be encoded into the instruction, this would be an address offset. Similarly, a branch instruction might jump to an address in a register plus an address offset that is encoded into the instruction. d32744 1 a32744 1 GDB styles text with this style using the ‘disassembler immediate’ d32747 2 a32748 2 ‘gdb.disassembler.STYLE_IMMEDIATE’ Use ‘STYLE_IMMEDIATE’ for any numerical values within a d32750 2 a32751 2 address offsets, or register numbers (The styles ‘STYLE_ADDRESS’, ‘STYLE_ADDRESS_OFFSET’, or ‘STYLE_REGISTER’ can be used in those d32754 1 a32754 1 GDB styles text with this style using the ‘disassembler immediate’ d32757 1 a32757 1 ‘gdb.disassembler.STYLE_SYMBOL’ d32766 2 a32767 2 Here ‘foo’ is the name of a symbol, and should be given the ‘STYLE_SYMBOL’ style. d32770 1 a32770 1 automatically by the ‘DisassemblerAddressPart’ class (*note d32773 1 a32773 1 GDB styles text with this style using the ‘disassembler symbol’ d32776 1 a32776 1 ‘gdb.disassembler.STYLE_COMMENT_START’ d32779 1 a32779 1 ‘DisassemblerTextPiece’ to which they are applied, the comment d32783 2 a32784 2 This means that, after a ‘STYLE_COMMENT_START’ piece has been seen, GDB will apply the comment style until the end of the line, d32787 1 a32787 1 GDB styles text with this style using the ‘disassembler comment’ d32790 1 a32790 1 The following functions are also contained in the ‘gdb.disassembler’ d32795 1 a32795 1 ‘gdb.disassembler.Disassembler’ or ‘None’. d32797 1 a32797 1 The optional ARCHITECTURE is either a string, or the value ‘None’. d32799 1 a32799 1 known to GDB, as returned either from ‘gdb.Architecture.name’ d32801 1 a32801 1 ‘gdb.architecture_names’ (*note gdb.architecture_names: d32805 1 a32805 1 ARCHITECTURE, or if ARCHITECTURE is ‘None’, then DISASSEMBLER will d32808 3 a32810 3 GDB only records a single disassembler for each architecture, and a single global disassembler. Calling ‘register_disassembler’ for an architecture, or for the global disassembler, will replace any d32814 1 a32814 1 If DISASSEMBLER is ‘None’ then any disassembler currently d32818 7 a32824 6 an architecture specific disassembler. If none has been registered then GDB looks for a global disassembler (one registered with ARCHITECTURE set to ‘None’). Only one disassembler is called to perform disassembly, so, if there is both an architecture specific disassembler, and a global disassembler registered, it is the architecture specific disassembler that will be used. d32832 1 a32832 1 You can use the ‘maint info python-disassemblers’ command (*note d32839 1 a32839 1 sub-class, of ‘DisassembleInfo’. d32842 3 a32844 3 ‘read_memory’ method on INFO will be called. By sub-classing ‘DisassembleInfo’ and overriding the ‘read_memory’ method, it is possible to intercept calls to ‘read_memory’ from the builtin d32848 6 a32853 6 ‘DisassembleInfo.read_memory’ raises a ‘gdb.MemoryError’, it is the internal disassembler itself that reports the memory error to GDB. The reason for this is that the disassembler might probe memory to see if a byte is readable or not; if the byte can't be read then the disassembler may choose not to report an error, but instead to disassemble the bytes that it does have available. d32856 1 a32856 1 ‘DisassemblerResult’ is returned from ‘builtin_disassemble’, d32860 1 a32860 1 A ‘MemoryError’ will be raised if ‘builtin_disassemble’ is unable d32864 8 a32871 8 Any exception that is not a ‘MemoryError’, that is raised in a call to ‘read_memory’, will pass through ‘builtin_disassemble’, and be visible to the caller. Finally, there are a few cases where GDB's builtin disassembler can fail for reasons that are not covered by ‘MemoryError’. In these cases, a ‘GdbError’ will be raised. The contents of the exception will be a string describing the problem the disassembler d32876 1 a32876 1 ‘## Comment’, to each line of disassembly output: d32890 2 a32891 2 The following example creates a sub-class of ‘DisassembleInfo’ in order to intercept the ‘read_memory’ calls, within ‘read_memory’ any d32924 3 a32926 3 When GDB encounters a new objfile (*note Objfiles In Python::), e.g. the primary executable, or any shared libraries used by the inferior, GDB will attempt to load the corresponding debug information for that d32928 2 a32929 2 itself, or within a separate objfile which GDB will automatically locate and load. d32943 3 a32945 3 object which has the ‘name’ and ‘enabled’ attributes, and implements the ‘__call__’ method. When GDB encounters an objfile for which it is unable to find any debug information, it invokes the ‘__call__’ method. d32948 1 a32948 1 The ‘gdb.missing_debug’ Module d32951 2 a32952 2 GDB comes with a ‘gdb.missing_debug’ module which contains the following class and global function: d32955 1 a32955 2 ‘MissingDebugHandler’ is a base class from which user-created d32957 3 a32959 2 from this class, so long as any user created handler has the ‘name’ and ‘enabled’ attributes, and implements the ‘__call__’ method. d32964 2 a32965 2 characters ‘[-_a-zA-Z0-9]’, creating a handler with an invalid name raises a ‘ValueError’ exception. d32968 2 a32969 2 Sub-classes must override the ‘__call__’ method. The OBJFILE argument will be a ‘gdb.Objfile’, this is the objfile for d32972 2 a32973 2 The return value from the ‘__call__’ method indicates what GDB should do next. The possible return values are: d32975 1 a32975 1 • ‘None’ d32980 1 a32980 1 • ‘True’ d32991 12 a33002 12 debug information handlers are not invoked a second time, this prevents a badly behaved handler causing GDB to get stuck in a loop. GDB will continue without any debug information for OBJFILE. • ‘False’ This indicates that this handler has done everything that it intends to do with OBJFILE, but no separate debug information can be found. GDB will not call any other registered handlers for OBJFILE. GDB will continue without debugging information for OBJFILE. d33004 1 a33004 1 • A string d33011 2 a33012 2 Invoking the ‘__call__’ method from this base class will raise a ‘NotImplementedError’ exception. d33016 1 a33016 1 handler passed to the ‘__init__’ method. d33019 2 a33020 2 A modifiable attribute containing a boolean; when ‘True’, the handler is enabled, and will be used by GDB. When ‘False’, d33024 1 a33024 1 replace=False) d33027 1 a33027 1 HANDLER is an instance of a sub-class of ‘MissingDebugHandler’, or d33029 1 a33029 1 methods as ‘MissingDebugHandler’. d33032 2 a33033 2 be either a ‘gdb.Progspace’ (*note Progspaces In Python::) or ‘None’, in which case the handler is registered globally. The d33036 4 a33039 4 the same name, an attempt to add a handler with an already existing name raises an exception unless REPLACE is ‘True’, in which case the old handler is deleted and the new handler is prepended to the selected handler list. d33043 1 a33043 1 returns a value other than ‘None’, no further handlers are called d33052 1 a33052 1 When a new object file is read (for example, due to the ‘file’ command, d33054 2 a33055 2 Python support scripts in several ways: ‘OBJFILE-gdb.py’ and ‘.debug_gdb_scripts’ section. *Note Auto-loading extensions::. d33063 1 a33063 1 ‘set auto-load python-scripts [on|off]’ d33066 1 a33066 1 ‘show auto-load python-scripts’ d33069 1 a33069 1 ‘info auto-load python-scripts [REGEXP]’ d33073 1 a33073 1 the ‘.debug_gdb_scripts’ section and were either not found (*note d33075 1 a33075 1 ‘auto-load safe-path’ rejection (*note Auto-loading::). This is d33091 2 a33092 2 When reading an auto-loaded file or script, GDB sets the “current objfile”. This is available via the ‘gdb.current_objfile’ function d33119 3 a33121 3 ‘PrettyPrinter (NAME, SUBPRINTERS=None)’ This class specifies the API that makes ‘info pretty-printer’, ‘enable pretty-printer’ and ‘disable pretty-printer’ work. d33124 1 a33124 1 ‘SubPrettyPrinter (NAME)’ d33128 1 a33128 1 ‘RegexpCollectionPrettyPrinter (NAME)’ d33133 3 a33135 3 ‘FlagEnumerationPrinter (NAME)’ A pretty-printer which handles printing of ‘enum’ values. Unlike GDB's built-in ‘enum’ printing, this printer attempts to work d33138 1 a33138 1 the name of the ‘enum’ type to look up. d33140 1 a33140 1 ‘register_pretty_printer (OBJ, PRINTER, REPLACE=False)’ d33142 2 a33143 2 is ‘True’ then any existing copy of the printer is replaced. Otherwise a ‘RuntimeError’ exception is raised if a printer with d33153 1 a33153 1 ‘gdb.Type’ objects. d33155 1 a33155 1 ‘get_basic_type (TYPE)’ d33174 2 a33175 2 ‘has_field (TYPE, FIELD)’ Return ‘True’ if TYPE, assumed to be a type with fields (e.g., a d33178 2 a33179 2 ‘make_enum_dict (ENUM_TYPE)’ Return a Python ‘dictionary’ type produced from ENUM_TYPE. d33181 1 a33181 1 ‘deep_items (TYPE)’ d33183 2 a33184 2 ‘gdb.Type.iteritems’ method, except that the iterator returned by ‘deep_items’ will recursively traverse anonymous struct or union d33204 1 a33204 1 ‘get_type_recognizers ()’ d33209 1 a33209 1 ‘apply_type_recognizers (recognizers, type_obj)’ d33212 1 a33212 1 Otherwise, return ‘None’. This is called by GDB during the d33215 1 a33215 1 ‘register_type_printer (locus, printer)’ d33218 4 a33221 4 argument is either a ‘gdb.Objfile’, in which case the printer is registered with that objfile; a ‘gdb.Progspace’, in which case the printer is registered with that progspace; or ‘None’, in which case the printer is registered globally. d33223 1 a33223 1 ‘TypePrinter’ d33225 2 a33226 2 Type printers are encouraged, but not required, to derive from this class. It defines a constructor: d33232 1 d33241 1 a33241 1 ‘substitute_prompt (STRING)’ d33248 1 a33248 1 ‘\\’ d33250 2 a33251 1 ‘\e’ d33253 2 a33254 1 ‘\f’ d33257 2 a33258 1 ‘\n’ d33260 2 a33261 1 ‘\p’ d33264 2 a33265 1 ‘\r’ d33267 2 a33268 1 ‘\t’ d33271 2 a33272 1 ‘\v’ d33274 2 a33275 1 ‘\w’ d33277 2 a33278 1 ‘\[’ d33280 6 a33285 5 are typically used with the ESC character, and are not counted in the string length. Example: "\[\e[0;34m\](gdb)\[\e[0m\]" will return a blue-colored "(gdb)" prompt where the length is five. ‘\]’ d33294 1 d33304 2 a33305 2 programming language (http://www.gnu.org/software/guile/). This feature is available only if GDB was configured using ‘--with-guile’. d33321 2 a33322 2 Guile is an implementation of the Scheme programming language and is the GNU project's official extension language. d33331 1 a33331 1 ‘DATA-DIRECTORY/guile’, where DATA-DIRECTORY is the data directory as d33333 1 a33333 1 as the “guile directory”, is automatically added to the Guile Search d33345 5 a33349 5 ‘guile-repl’ ‘gr’ The ‘guile-repl’ command can be used to start an interactive Guile prompt or “repl”. To return to GDB, type ‘,q’ or the ‘EOF’ character (e.g., ‘Ctrl-D’ on an empty prompt). These commands do d33352 3 a33354 3 ‘guile [SCHEME-EXPRESSION]’ ‘gu [SCHEME-EXPRESSION]’ The ‘guile’ command can be used to evaluate a Scheme expression. d33362 2 a33363 2 The result of the Scheme expression is displayed using normal Guile rules. d33368 3 a33370 3 If you do not provide an argument to ‘guile’, it will act as a multi-line command, like ‘define’. In this case, the Guile script is made up of subsequent command lines, given after the ‘guile’ d33372 1 a33372 1 ‘end’. For example: d33383 5 a33387 4 ‘source script-name’ The script name must end with ‘.scm’ and GDB must be configured to recognize the script language based on filename extension using the ‘script-extension’ setting. *Note Extending GDB: Extending GDB. d33389 2 a33390 2 ‘guile (load "script-name")’ This method uses the ‘load’ Guile function. It takes a string d33392 2 a33393 2 documentation for a description of this function. (*note (guile)Loading::). d33401 6 a33406 5 You can get quick online help for GDB's Guile API by issuing the command ‘help guile’, or by issuing the command ‘,help’ from an interactive Guile session. Furthermore, most Guile procedures provided by GDB have doc strings which can be obtained with ‘,describe PROCEDURE-NAME’ or ‘,d PROCEDURE-NAME’ from the Guile interactive prompt. d33442 2 a33443 2 At startup, GDB overrides Guile's ‘current-output-port’ and ‘current-error-port’ to print using GDB's output-paging streams. A d33446 1 a33446 1 Guile ‘signal’ exception is thrown with value ‘SIGINT’. d33450 2 a33451 2 evaluations in Guile and in GDB are counted separately, ‘$1’ in Guile is not the same value as ‘$1’ in GDB. d33453 3 a33455 3 GDB is not thread-safe. If your Guile program uses multiple threads, you must be careful to only call GDB-specific functions in the GDB thread. d33460 2 a33461 2 • GDB installs handlers for ‘SIGCHLD’ and ‘SIGINT’. Guile code must not override these, or even change the options using ‘sigaction’. d33464 1 a33464 1 common for GUI toolkits to install a ‘SIGCHLD’ handler. d33466 1 a33466 1 • GDB takes care to mark its internal file descriptors as d33473 1 a33473 1 GDB introduces a new Guile module, named ‘gdb’. All methods and d33475 1 a33475 1 automatically ‘import’ the ‘gdb’ module, scripts must do this d33477 1 a33477 1 GDB leaves the choice of how the ‘gdb’ module is imported to the user. d33486 1 a33486 1 ‘gdb:’ as a prefix to all module functions and variables. d33488 4 a33491 3 The rest of this manual assumes the ‘gdb’ module has been imported without any prefix. See the Guile documentation for ‘use-modules’ for more information (*note (guile)Using Guile Modules::). d33503 1 a33503 1 The ‘(gdb)’ module provides these basic Guile functions. d33508 3 a33510 2 exception happens while COMMAND runs, it is translated as described in *note Guile Exception Handling: Guile Exception Handling. d33513 2 a33514 2 having originated from the user invoking it interactively. It must be a boolean value. If omitted, it defaults to ‘#f’. d33518 3 a33520 3 If the TO-STRING parameter is ‘#t’, then output will be collected by ‘execute’ and returned as a string. The default is ‘#f’, in which case the return value is unspecified. If TO-STRING is ‘#t’, d33528 6 a33533 6 NUMBER is negative, then GDB will take its absolute value and count backward from the last element (i.e., the most recent element) to find the value to return. If NUMBER is zero, then GDB will return the most recent element. If the element specified by NUMBER doesn't exist in the value history, a ‘gdb:error’ exception will be raised. d33536 1 a33536 1 of ‘’ (*note Values From Inferior In Guile::). d33538 5 a33542 4 _Note:_ GDB's value history is independent of Guile's. ‘$1’ in GDB's value history contains the result of evaluating an expression from GDB's command line and ‘$1’ from Guile's history contains the result of evaluating an expression from Guile's command line. d33545 2 a33546 2 Append VALUE, an instance of ‘’, to GDB's value history. Return its index in the history. d33553 3 a33555 3 Parse EXPRESSION as an expression in the current language, evaluate it, and return the result as a ‘’. The EXPRESSION must be a string. d33561 1 a33561 1 convenience variable (*note Convenience Vars::) as a ‘’. d33585 1 a33585 1 string passed to ‘--host’ when GDB was configured. d33589 1 a33589 1 string passed to ‘--target’ when GDB was configured. d33597 1 a33597 1 The values exposed by GDB to Guile are known as “GDB objects”. There d33602 1 a33602 1 Return the kind of the GDB object, e.g., ‘’, as a d33607 1 a33607 1 ‘’ d33610 1 a33610 1 ‘’ d33613 1 a33613 1 ‘’ d33616 1 a33616 1 ‘’ d33619 1 a33619 1 ‘’ d33622 1 a33622 1 ‘’ d33625 1 a33625 1 ‘’ d33628 1 a33628 1 ‘’ d33631 1 a33631 1 ‘’ d33634 1 a33634 1 ‘’ d33637 1 a33637 1 ‘’ d33640 1 a33640 1 ‘’ d33643 1 a33643 1 ‘’ d33646 1 a33646 1 ‘’ d33649 1 a33649 1 ‘’ d33652 1 a33652 1 ‘’ d33655 1 a33655 1 ‘’ d33658 1 a33658 1 ‘’ d33661 1 a33661 1 ‘’ d33664 1 a33664 1 ‘’ d33668 15 a33682 1 function ‘eq?’ may be applied to them. d33684 3 a33686 9 ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ d33694 5 a33698 5 When executing the ‘guile’ command, Guile exceptions uncaught within the Guile code are translated to calls to the GDB error-reporting mechanism. If the command that called ‘guile’ does not handle the error, GDB will terminate it and report the error according to the setting of the ‘guile print-stack’ parameter. d33700 1 a33700 1 The ‘guile print-stack’ parameter has three settings: d33702 1 a33702 1 ‘none’ d33705 1 a33705 1 ‘message’ d33715 1 a33715 1 ‘full’ d33750 1 a33750 1 exceptions like ‘wrong-type-arg’ and ‘out-of-range’. d33752 2 a33753 2 User interrupt (via ‘C-c’ or by typing ‘q’ at a pagination prompt) is translated to a Guile ‘signal’ exception with value ‘SIGINT’. d33757 1 a33757 1 ‘gdb:error’ d33760 1 a33760 1 ‘gdb:invalid-object’ d33763 1 a33763 1 ‘’ object becomes invalid if the user deletes it d33768 1 a33768 1 ‘gdb:memory-error’ d33772 1 a33772 1 ‘gdb:pp-type-error’ d33777 1 a33777 1 ‘(gdb)’ module. d33780 1 a33780 1 Return a ‘’ object given by its KEY and ARGS, which d33782 2 a33783 1 documentation for more information (*note (guile)Exceptions::). d33786 2 a33787 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d33790 1 a33790 1 Return the ARGS field of a ‘’ object. d33793 1 a33793 1 Return the ARGS field of a ‘’ object. d33801 4 a33804 3 GDB provides values it obtains from the inferior program in an object of type ‘’. GDB uses this object for its internal bookkeeping of the inferior's values, and for fetching values when necessary. d33806 1 a33806 1 GDB does not memoize ‘’ objects. ‘make-value’ always d33814 4 a33817 4 A ‘’ that represents a function can be executed via inferior function call with ‘value-call’. Any arguments provided to the call must match the function's prototype, and must be provided in the order specified by that prototype. d33819 1 a33819 1 For example, ‘some-val’ is a ‘’ instance representing a d33825 1 a33825 1 Any values returned from a function call are ‘’ objects. d33827 6 a33832 6 Note: Unlike Python scripting in GDB, inferior values that are simple scalars cannot be used directly in Scheme expressions that are valid for the value's data type. For example, ‘(+ (parse-and-eval "int_variable") 2)’ does not work. And inferior values that are structures or instances of some class cannot be accessed using any special syntax, instead ‘value-field’ must be used. d33834 1 a33834 1 The following value-related procedures are provided by the ‘(gdb)’ d33838 2 a33839 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d33842 1 a33842 1 Many Scheme values can be converted directly to a ‘’ d33848 2 a33849 2 *Note Architectures In Guile::, for a list of the builtin types for an architecture. d33852 5 a33856 1 ‘make-value’ is not specified: d33858 4 a33861 8 Scheme boolean A Scheme boolean is converted the boolean type for the current language. Scheme integer A Scheme integer is converted to the first of a C ‘int’, ‘unsigned int’, ‘long’, ‘unsigned long’, ‘long long’ or ‘unsigned long long’ type for the current architecture that d33865 1 a33865 1 integer an ‘out-of-range’ exception is thrown. d33867 2 a33868 2 Scheme real A Scheme real is converted to the C ‘double’ type for the d33871 1 a33871 1 Scheme string d33876 2 a33877 2 Guile's ‘SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE’ conversion strategy (*note (guile)Strings::). d33880 1 a33880 1 a ‘wrong-type-arg’ exception is thrown. d33882 3 a33884 3 ‘’ If VALUE is a ‘’ object (*note Lazy Strings In Guile::), then the ‘lazy-string->value’ procedure is d33888 1 a33888 1 a ‘wrong-type-arg’ exception is thrown. d33890 1 a33890 1 Scheme bytevector d33893 1 a33893 1 the result is essentially created by using ‘memcpy’. d33896 1 a33896 1 result is an array of type ‘uint8’ of the same length. d33899 2 a33900 2 Return ‘#t’ if the compiler optimized out VALUE, thus it is not available for fetching from the inferior. Otherwise return ‘#f’. d33903 2 a33904 2 If VALUE is addressable, returns a ‘’ object representing the address. Otherwise, ‘#f’ is returned. d33907 1 a33907 1 Return the type of VALUE as a ‘’ object (*note Types In d33914 3 a33916 3 value is embedded, if any. If the value is of pointer or reference to a class type, it will compute the dynamic type of the referenced object, and return a pointer or reference to that type, d33922 1 a33922 1 just return the static type of the value as in ‘ptype foo’. *Note d33926 1 a33926 1 Return a new instance of ‘’ that is the result of d33928 1 a33928 1 ‘’ object. If the cast cannot be performed for some d33932 1 a33932 1 Like ‘value-cast’, but works as if the C++ ‘dynamic_cast’ operator d33936 1 a33936 1 Like ‘value-cast’, but works as if the C++ ‘reinterpret_cast’ d33940 1 a33940 1 For pointer data types, this method returns a new ‘’ d33942 1 a33942 1 example, if ‘foo’ is a C pointer to an ‘int’, declared in your C d33947 2 a33948 2 then you can use the corresponding ‘’ to access what ‘foo’ points to like this: d33952 2 a33953 2 The result ‘bar’ will be a ‘’ object holding the value pointed to by ‘foo’. d33955 2 a33956 2 A similar function ‘value-referenced-value’ exists which also returns ‘’ objects corresponding to the values pointed d33958 5 a33962 5 reference values). However, the behavior of ‘value-dereference’ differs from ‘value-referenced-value’ by the fact that the behavior of ‘value-dereference’ is identical to applying the C unary operator ‘*’ on a given value. For example, consider a reference to a pointer ‘ptrref’, declared in your C++ program as d33970 6 a33975 6 Though ‘ptrref’ is a reference value, one can apply the method ‘value-dereference’ to the ‘’ object corresponding to it and obtain a ‘’ which is identical to that corresponding to ‘val’. However, if you apply the method ‘value-referenced-value’, the result would be a ‘’ object identical to that corresponding to ‘ptr’. d33981 4 a33984 4 The ‘’ object ‘scm-val’ is identical to that corresponding to ‘val’, and ‘scm-ptr’ is identical to that corresponding to ‘ptr’. In general, ‘value-dereference’ can be applied whenever the C unary operator ‘*’ can be applied to the d33986 1 a33986 1 ‘value-dereference’ and ‘value-referenced-value’ is allowed, the d33989 2 a33990 2 ‘’ objects corresponding to pointers (‘’ objects with type code ‘TYPE_CODE_PTR’) in a C/C++ program. d33994 1 a33994 1 ‘’ object corresponding to the value referenced by the d33996 1 a33996 1 ‘value-dereference’ and ‘value-referenced-value’ produce identical d33998 3 a34000 3 ‘value-dereference’ cannot get the values referenced by reference values. For example, consider a reference to an ‘int’, declared in your C++ program as d34005 4 a34008 4 then applying ‘value-dereference’ to the ‘’ object corresponding to ‘ref’ will result in an error, while applying ‘value-referenced-value’ will result in a ‘’ object identical to that corresponding to ‘val’. d34014 2 a34015 2 The ‘’ object ‘scm-val’ is identical to that corresponding to ‘val’. d34018 2 a34019 2 Return a new ‘’ object which is a reference to the value encapsulated by ‘’ object VALUE. d34022 2 a34023 2 Return a new ‘’ object which is an rvalue reference to the value encapsulated by ‘’ object VALUE. d34026 2 a34027 2 Return a new ‘’ object which is a ‘const’ version of ‘’ object VALUE. d34030 1 a34030 1 Return field FIELD-NAME from ‘’ object VALUE. d34033 2 a34034 2 Return the value of array VALUE at index INDEX. The VALUE argument must be a subscriptable ‘’ object. d34037 2 a34038 2 Perform an inferior function call, taking VALUE as a pointer to the function to call. Each element of list ARG-LIST must be a d34043 1 a34043 1 Return the Scheme boolean representing ‘’ VALUE. The d34047 1 a34047 1 Return the Scheme integer representing ‘’ VALUE. The d34051 1 a34051 1 Return the Scheme real number representing ‘’ VALUE. d34055 1 a34055 1 Return a Scheme bytevector with the raw contents of ‘’ d34072 2 a34073 2 pointer to or an array of characters or ints of type ‘wchar_t’, ‘char16_t’, or ‘char32_t’. d34076 2 a34077 2 naming the encoding of the string in the ‘’, such as ‘"ascii"’, ‘"iso-8859-6"’ or ‘"utf-8"’. It accepts the same d34079 1 a34079 1 ‘scm_from_stringn’ function, and the Guile codec machinery will be d34081 1 a34081 1 ENCODING is the empty string, then either the ‘target-charset’ d34086 3 a34088 3 The optional ERRORS argument is one of ‘#f’, ‘error’ or ‘substitute’. ‘error’ and ‘substitute’ must be symbols. If ERRORS is not specified, or if its value is ‘#f’, then the default d34090 4 a34093 4 ‘set-port-conversion-strategy!’. If the value is ‘'error’ then an exception is thrown if there is any conversion error. If the value is ‘'substitute’ then any conversion error is replaced with question marks. *Note (guile)Strings::. d34097 1 a34097 1 Scheme integer and not a ‘’ integer. d34101 2 a34102 2 If this ‘’ represents a string, then this method converts VALUE to a ‘’ integer. d34125 2 a34126 2 Return ‘#t’ if VALUE has not yet been fetched from the inferior. Otherwise return ‘#f’. GDB does not fetch values until necessary, d34131 2 a34132 2 The value of ‘somevar’ is not fetched at this time. It will be fetched when the value is needed, or when the ‘fetch-lazy’ d34136 4 a34139 4 Return a ‘’ that will be lazily fetched from the target. The object of type ‘’ whose value to fetch is specified by its TYPE and its target memory ADDRESS, which is a Scheme integer. d34142 1 a34142 1 If VALUE is a lazy value (‘(value-lazy? value)’ is ‘#t’), then the d34151 1 a34151 1 Return the string representation (print form) of ‘’ d34160 2 a34161 2 The ‘(gdb)’ module provides several functions for performing arithmetic on ‘’ objects. The arithmetic is performed as if it were d34217 1 a34217 1 Scheme does not provide a ‘not-equal’ function, and thus Guile d34226 1 a34226 1 GDB represents types from the inferior in objects of type ‘’. d34228 1 a34228 1 The following type-related procedures are provided by the ‘(gdb)’ d34232 2 a34233 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d34238 1 a34238 1 If BLOCK is given, it is an object of type ‘’, and NAME d34242 1 a34242 1 Ordinarily, this function will return an instance of ‘’. d34247 1 a34247 1 ‘TYPE_CODE_’ constants defined below. d34251 2 a34252 2 ‘struct’, ‘union’, or ‘enum’ in C and C++; not all languages have this concept. If this type has no tag name, then ‘#f’ is returned. d34255 1 a34255 1 Return the name of TYPE. If this type has no name, then ‘#f’ is d34260 2 a34261 2 anonymous types. For example, for an anonymous C struct ‘"struct {...}"’ is returned. d34264 2 a34265 2 Return the size of this type, in target ‘char’ units. Usually, a target's ‘char’ type will be an 8-bit byte. However, on some d34269 1 a34269 1 Return a new ‘’ that represents the real type of TYPE, d34273 1 a34273 1 Return a new ‘’ object which represents an array of this d34281 1 a34281 1 Return a new ‘’ object which represents a vector of this d34283 4 a34286 4 the vector; in this case the lower bound is zero. If two arguments are given, the first argument is the lower bound of the vector, and the second argument is the upper bound of the vector. A vector's length must not be negative, but the bounds can be. d34288 1 a34288 1 The difference between an ‘array’ and a ‘vector’ is that arrays d34294 1 a34294 1 Return a new ‘’ object which represents a pointer to d34302 1 a34302 1 Return a new ‘’ object which represents a reference to d34306 1 a34306 1 Return a new ‘’ object which represents the target type d34310 5 a34314 5 object. For an array type (meaning C-like arrays), the target type is the type of the elements of the array. For a function or method type, the target type is the type of the return value. For a complex type, the target type is the type of the elements. For a typedef, the target type is the aliased type. d34320 2 a34321 2 Return a new ‘’ object which represents a ‘const’-qualified variant of TYPE. d34324 2 a34325 2 Return a new ‘’ object which represents a ‘volatile’-qualified variant of TYPE. d34328 3 a34330 3 Return a new ‘’ object which represents an unqualified variant of TYPE. That is, the result is neither ‘const’ nor ‘volatile’. d34333 1 a34333 1 Return the number of fields of ‘’ TYPE. d34337 1 a34337 1 types, ‘fields’ has the usual meaning. Range types have two d34351 3 a34353 3 type ‘’. *Note Fields of a type in Guile::. If the type does not have fields, or FIELD-NAME is not a field of TYPE, an exception is thrown. d34355 2 a34356 2 For example, if ‘some-type’ is a ‘’ instance holding a structure type, you can access its ‘foo’ field with: d34360 1 a34360 1 ‘bar’ will be a ‘’ object. d34363 2 a34364 2 Return ‘#t’ if ‘’ TYPE has field named NAME. Otherwise return ‘#f’. d34368 1 a34368 1 defined in the ‘(gdb)’ module: d34370 1 a34370 1 ‘TYPE_CODE_PTR’ d34373 1 a34373 1 ‘TYPE_CODE_ARRAY’ d34376 1 a34376 1 ‘TYPE_CODE_STRUCT’ d34379 1 a34379 1 ‘TYPE_CODE_UNION’ d34382 1 a34382 1 ‘TYPE_CODE_ENUM’ d34385 1 a34385 1 ‘TYPE_CODE_FLAGS’ d34388 1 a34388 1 ‘TYPE_CODE_FUNC’ d34391 1 a34391 1 ‘TYPE_CODE_INT’ d34394 1 a34394 1 ‘TYPE_CODE_FLT’ d34397 2 a34398 2 ‘TYPE_CODE_VOID’ The special type ‘void’. d34400 1 a34400 1 ‘TYPE_CODE_SET’ d34403 1 a34403 1 ‘TYPE_CODE_RANGE’ d34406 1 a34406 1 ‘TYPE_CODE_STRING’ d34411 1 a34411 1 ‘TYPE_CODE_BITSTRING’ d34414 1 a34414 1 ‘TYPE_CODE_ERROR’ d34417 1 a34417 1 ‘TYPE_CODE_METHOD’ d34420 1 a34420 1 ‘TYPE_CODE_METHODPTR’ d34423 1 a34423 1 ‘TYPE_CODE_MEMBERPTR’ d34426 1 a34426 1 ‘TYPE_CODE_REF’ d34429 1 a34429 1 ‘TYPE_CODE_RVALUE_REF’ d34432 1 a34432 1 ‘TYPE_CODE_CHAR’ d34435 1 a34435 1 ‘TYPE_CODE_BOOL’ d34438 1 a34438 1 ‘TYPE_CODE_COMPLEX’ d34441 1 a34441 1 ‘TYPE_CODE_TYPEDEF’ d34444 1 a34444 1 ‘TYPE_CODE_NAMESPACE’ d34447 1 a34447 1 ‘TYPE_CODE_DECFLOAT’ d34450 1 a34450 1 ‘TYPE_CODE_INTERNAL_FUNCTION’ d34454 1 a34454 1 ‘gdb.TYPE_CODE_XMETHOD’ d34458 1 a34458 1 ‘gdb.TYPE_CODE_FIXED_POINT’ d34461 1 a34461 1 ‘gdb.TYPE_CODE_NAMESPACE’ d34464 1 a34464 1 Further support for types is provided in the ‘(gdb types)’ Guile d34467 1 a34467 1 Each field is represented as an object of type ‘’. d34469 1 a34469 1 The following field-related procedures are provided by the ‘(gdb)’ d34473 2 a34474 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d34477 1 a34477 1 Return the name of the field, or ‘#f’ for anonymous fields. d34481 1 a34481 1 ‘’, but it can be ‘#f’ in some situations. d34484 1 a34484 1 Return the enum value represented by ‘’ FIELD. d34487 2 a34488 2 Return the bit position of ‘’ FIELD. This attribute is not available for ‘static’ fields (as in C++). d34492 2 a34493 2 ‘’ FIELD in bits. Otherwise, zero is returned; in which case the field's size is given by its type. d34496 3 a34498 2 Return ‘#t’ if the field is artificial, usually meaning that it was provided by the compiler and not the user. Otherwise return ‘#f’. d34501 2 a34502 2 Return ‘#t’ if the field represents a base class of a C++ structure. Otherwise return ‘#f’. d34514 1 a34514 1 ‘make-pretty-printer’. d34517 1 a34517 1 ‘(gdb)’ module: d34520 1 a34520 1 Return a ‘’ object named NAME. d34526 1 a34526 1 Otherwise LOOKUP-FUNCTION returns ‘#f’. d34529 2 a34530 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34533 1 a34533 1 Return ‘#t’ if PRETTY-PRINTER is enabled. Otherwise return ‘#f’. d34536 2 a34537 2 Set the enabled flag of PRETTY-PRINTER to FLAG. The value returned is unspecified. d34548 1 a34548 1 Return an object of type ‘’. d34552 5 a34556 5 ‘display-hint’ DISPLAY-HINT provides a hint to GDB or GDB front end via MI to change the formatting of the value being printed. The value must be a string or ‘#f’ (meaning there is no hint). Several values for DISPLAY-HINT are predefined by GDB: d34558 1 a34558 1 ‘array’ d34560 2 a34561 2 The CLI uses this to respect parameters such as ‘set print elements’ and ‘set print array’. d34563 3 a34565 3 ‘map’ Indicate that the object being printed is "map-like", and that the children of this value can be assumed to d34568 1 a34568 1 ‘string’ d34570 1 a34570 1 If the printer's ‘to-string’ function returns a Guile d34574 2 a34575 2 possibly escaping some characters, respecting ‘set print elements’, and the like. d34577 1 a34577 1 ‘to-string’ d34579 1 a34579 1 ‘’ object, or ‘#f’. d34581 1 a34581 1 When printing from the CLI, if the ‘to-string’ method exists, d34583 1 a34583 1 ‘children’. Exactly how this formatting is done is dependent d34586 2 a34587 2 Settings::), the CLI may print just the result of ‘to-string’ in a stack trace, omitting the result of ‘children’. d34592 2 a34593 2 ‘’, then GDB prints this value. This may result in a call to another pretty-printer. d34596 1 a34596 1 convertible to a ‘’, then GDB performs the d34600 1 a34600 1 to ‘’; other types are not. d34602 1 a34602 1 Finally, if this method returns ‘#f’ then no further d34609 1 a34609 1 TO-STRING may also be ‘#f’ in which case it is left to d34612 1 a34612 1 ‘children’ d34614 1 a34614 1 ‘’ object, or ‘#f’. d34620 4 a34623 4 returned by the iterator must be a tuple holding two elements. The first element is the "name" of the child; the second element is the child's value. The value can be any Guile object which is convertible to a GDB value. d34625 1 a34625 1 If CHILDREN is ‘#f’, GDB will act as though the value has no d34628 2 a34629 2 Children may be hidden from display based on the value of ‘set print max-depth’ (*note Print Settings::). d34632 1 a34632 1 pretty-printer for a ‘’: d34635 1 a34635 1 This function takes a ‘’ object as an argument. If a d34637 1 a34637 1 such printer exists, then this returns ‘#f’. d34647 3 a34649 2 • Per-objfile list of pretty-printers (*note Objfiles In Guile::). • Per-progspace list of pretty-printers (*note Progspaces In d34651 2 a34652 1 • The global list of pretty-printers (*note Guile Pretty Printing d34656 10 a34665 9 the lookup function of each enabled object in turn. Lookup stops when a lookup function returns a non-‘#f’ value or when the list is exhausted. Lookup functions must return either a ‘’ object or ‘#f’. Otherwise an exception is thrown. GDB first checks the result of ‘objfile-pretty-printers’ of each ‘’ in the current program space and iteratively calls each enabled lookup function in the list for that ‘’ until a non-‘#f’ object is returned. If no pretty-printer is found in the d34667 5 a34671 5 ‘progspace-pretty-printers’ of the current program space, calling each enabled function until a non-‘#f’ object is returned. After these lists have been exhausted, it tries the global pretty-printers list, obtained with ‘pretty-printers’, again calling each enabled function until a non-‘#f’ object is returned. d34676 1 a34676 1 ‘’ object is returned. d34679 2 a34680 2 underlying data structure may have changed and the pretty-printer is out of date. d34684 1 a34684 1 For example, if ‘print frame-arguments’ is on, a backtrace can become d34688 1 a34688 1 ‘set-pretty-printer-enabled!’. *Note Guile Pretty Printing API::. d34699 1 a34699 1 Here is an example showing how a ‘std::string’ printer might be d34727 1 a34727 1 object. If not, it returns ‘#f’. d34730 3 a34732 3 package. If your pretty-printers are for use with a library, we further recommend embedding a version number into the package name. This practice will enable GDB to load multiple versions of your d34738 3 a34740 3 An ideal auto-load file will consist solely of ‘import’s of your printer modules, followed by a call to a register pretty-printers with the current objfile. d34745 5 a34749 5 GDB is able to load both sets of printers simultaneously. Then, because the search for pretty-printers is done by objfile, and because your auto-loaded code took care to register your library's printers with a specific objfile, GDB will find the correct printers for the specific version of the library used by each inferior. d34751 2 a34752 2 To continue the ‘my::string’ example, this code might appear in ‘(my-project my-library v1)’: d34764 8 a34771 8 The previous example illustrates a basic pretty-printer. There are a few things that can be improved on. The printer only handles one type, whereas a library typically has several types. One could install a lookup function for each desired type in the library, but one could also have a single lookup function recognize several types. The latter is the conventional way this is handled. If a pretty-printer can handle multiple data types, then its “subprinters” are the printers for the individual data types. d34773 1 a34773 1 The ‘(gdb printing)’ module provides a formal way of solving this d34803 2 a34804 2 ‘(gdb printing)’ module. Instead a function is provided to build up the object that handles the lookup. d34820 1 a34820 1 corresponding output of ‘info pretty-printer’: d34835 4 a34838 4 is created with the ‘make-command’ Guile function, and added to GDB with the ‘register-command!’ Guile function. This two-step approach is taken to separate out the side-effect of adding the command to GDB from ‘make-command’. d34841 1 a34841 1 consist of multiple lines and are terminated with ‘end’. a34845 1 d34851 1 a34851 1 The result is the ‘’ object representing the command. d34853 1 a34853 1 with ‘register-command!’. d34858 1 a34858 1 and FROM-TTY. The argument SELF is the ‘’ object d34860 4 a34863 4 representing the arguments passed to the command, after leading and trailing whitespace has been stripped. The argument FROM-TTY is a boolean flag and specifies whether the command should consider itself to have been originated from the user invoking it d34865 1 a34865 1 into a GDB ‘error’ call. Otherwise, the return value is ignored. d34867 1 a34867 1 The argument COMMAND-CLASS is one of the ‘COMMAND_’ constants d34869 1 a34869 1 command in the help system. The default is ‘COMMAND_NONE’. d34871 1 a34871 1 The argument COMPLETER is either ‘#f’, one of the ‘COMPLETE_’ d34874 1 a34874 1 not provided or if the value is ‘#f’, then no completion is d34883 1 a34883 1 is not documented." is used. d34886 3 a34888 3 Add COMMAND, a ‘’ object, to GDB's list of commands. It is an error to register a command more than once. The result is unspecified. d34891 2 a34892 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34897 2 a34898 2 by invoking the ‘dont-repeat’ function. This is similar to the user command ‘dont-repeat’, see *note dont-repeat: Define. d34909 1 a34909 1 Throw a ‘gdb:user-error’ exception. The argument MESSAGE is the d34911 3 a34913 2 ‘format’ Scheme function. *Note (guile)Formatted Output::. The argument ARGS is a list of the optional arguments of MESSAGE. d34929 3 a34931 3 If the COMPLETER option to ‘make-command’ is a procedure, it takes three arguments: SELF which is the ‘’ object, and TEXT and WORD which are both strings. The argument TEXT holds the d34938 1 a34938 1 ‘complete’ command (*note complete: Help.). d34942 6 a34947 6 • If the return value is a list, the contents of the list are used as the completions. It is up to COMPLETER to ensure that the contents actually do complete the word. An empty list is allowed, it means that there were no completions available. Only string elements of the list are used; other elements in the list are ignored. d34949 1 a34949 1 • If the return value is a ‘’ object, it is d34951 1 a34951 1 ‘completer-procedure’ to ensure that the results actually do d34955 1 a34955 1 • All other results are treated as though there were no d34960 4 a34963 4 top-level commands in the on-line help system; note that prefix commands are not listed under their own category but rather that of their top-level command. The available classifications are represented by constants defined in the ‘gdb’ module: d34965 1 a34965 1 ‘COMMAND_NONE’ d34970 1 a34970 1 ‘COMMAND_RUNNING’ d34972 2 a34973 2 ‘start’, ‘step’, and ‘continue’ are in this category. Type ‘help running’ at the GDB prompt to see a list of commands in this d34976 3 a34978 3 ‘COMMAND_DATA’ The command is related to data or variables. For example, ‘call’, ‘find’, and ‘print’ are in this category. Type ‘help data’ at the d34981 1 a34981 1 ‘COMMAND_STACK’ d34983 2 a34984 2 ‘backtrace’, ‘frame’, and ‘return’ are in this category. Type ‘help stack’ at the GDB prompt to see a list of commands in this d34987 5 a34991 4 ‘COMMAND_FILES’ This class is used for file-related commands. For example, ‘file’, ‘list’ and ‘section’ are in this category. Type ‘help files’ at the GDB prompt to see a list of commands in this category. d34993 1 a34993 1 ‘COMMAND_SUPPORT’ d34996 2 a34997 2 not related to the state of the inferior. For example, ‘help’, ‘make’, and ‘shell’ are in this category. Type ‘help support’ at d35000 4 a35003 4 ‘COMMAND_STATUS’ The command is an ‘info’-related command, that is, related to the state of GDB itself. For example, ‘info’, ‘macro’, and ‘show’ are in this category. Type ‘help status’ at the GDB prompt to see a d35006 4 a35009 4 ‘COMMAND_BREAKPOINTS’ The command has to do with breakpoints. For example, ‘break’, ‘clear’, and ‘delete’ are in this category. Type ‘help breakpoints’ at the GDB prompt to see a list of commands in this d35012 4 a35015 4 ‘COMMAND_TRACEPOINTS’ The command has to do with tracepoints. For example, ‘trace’, ‘actions’, and ‘tfind’ are in this category. Type ‘help tracepoints’ at the GDB prompt to see a list of commands in this d35018 1 a35018 1 ‘COMMAND_USER’ d35020 2 a35021 2 typically does not fit in one of the other categories. Type ‘help user-defined’ at the GDB prompt to see a list of commands in this d35024 1 a35024 1 ‘COMMAND_OBSCURE’ d35026 8 a35033 8 general interest to users. For example, ‘checkpoint’, ‘fork’, and ‘stop’ are in this category. Type ‘help obscure’ at the GDB prompt to see a list of commands in this category. ‘COMMAND_MAINTENANCE’ The command is only useful to GDB maintainers. The ‘maintenance’ and ‘flushregs’ commands are in this category. Type ‘help internals’ at the GDB prompt to see a list of commands in this d35037 3 a35039 3 specifying it via an argument at initialization, or by returning it from the ‘completer’ procedure. These predefined completion constants are all defined in the ‘gdb’ module: d35041 1 a35041 1 ‘COMPLETE_NONE’ d35044 1 a35044 1 ‘COMPLETE_FILENAME’ d35047 3 a35049 3 ‘COMPLETE_LOCATION’ This constant means that location completion should be done. *Note Location Specifications::. d35051 1 a35051 1 ‘COMPLETE_COMMAND’ d35055 1 a35055 1 ‘COMPLETE_SYMBOL’ d35059 1 a35059 1 ‘COMPLETE_EXPRESSION’ d35082 1 a35082 1 You can implement new GDB “parameters” using Guile (1). d35085 1 a35085 1 Two examples are: ‘set follow-fork’ and ‘set charset’. Setting these d35087 2 a35088 2 define parameters that can be used to influence behavior in custom Guile scripts and commands. d35090 4 a35093 4 A new parameter is defined with the ‘make-parameter’ Guile function, and added to GDB with the ‘register-parameter!’ Guile function. This two-step approach is taken to separate out the side-effect of adding the parameter to GDB from ‘make-parameter’. d35095 2 a35096 2 Parameters are exposed to the user via the ‘set’ and ‘show’ commands. *Note Help::. a35103 1 d35107 5 a35111 5 the ‘set print’ set of parameters. If NAME is ‘print foo’, then ‘print’ will be searched as the prefix parameter. In this case the parameter can subsequently be accessed in GDB as ‘set print foo’. If NAME consists of multiple words, and no prefix parameter group can be found, an exception is raised. d35113 1 a35113 1 The result is the ‘’ object representing the d35115 1 a35115 1 registered with GDB with ‘register-parameter!’. d35119 4 a35122 4 The argument COMMAND-CLASS should be one of the ‘COMMAND_’ constants (*note Commands In Guile::). This argument tells GDB how to categorize the new parameter in the help system. The default is ‘COMMAND_NONE’. d35124 1 a35124 1 The argument PARAMETER-TYPE should be one of the ‘PARAM_’ constants d35127 1 a35127 1 completion. The default is ‘PARAM_BOOLEAN’. d35129 2 a35130 2 If PARAMETER-TYPE is ‘PARAM_ENUM’, then ENUM-LIST must be a list of strings. These strings represent the possible values for the d35133 1 a35133 1 If PARAMETER-TYPE is not ‘PARAM_ENUM’, then the presence of d35137 1 a35137 1 the ‘’ object representing the parameter. GDB will d35139 1 a35139 1 the ‘set’ API (for example, ‘set foo off’). The value of the d35142 4 a35145 4 trailing newline if the string is non-empty. GDB generally doesn't print anything when a parameter is set, thus typically this function should return ‘""’. A non-empty string result should typically be used for displaying warnings and errors. d35148 1 a35148 1 is the ‘’ object representing the parameter, and d35150 4 a35153 4 GDB will call this function when a PARAMETER's ‘show’ API has been invoked (for example, ‘show foo’). This function must return a string, and will be displayed to the user. GDB will add a trailing newline. d35158 1 a35158 1 The argument SET-DOC is the help text for this parameter's ‘set’ d35161 1 a35161 1 The argument SHOW-DOC is the help text for this parameter's ‘show’ d35166 1 a35166 1 ‘’ object and its result is used as the initial d35171 1 a35171 1 Add PARAMETER, a ‘’ object, to GDB's list of d35176 2 a35177 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d35181 1 a35181 1 ‘’ object or a string naming the parameter. d35185 1 a35185 1 must be an object of type ‘’. GDB does validation d35189 1 a35189 1 available types are represented by constants defined in the ‘gdb’ d35192 3 a35194 3 ‘PARAM_BOOLEAN’ The value is a plain boolean. The Guile boolean values, ‘#t’ and ‘#f’ are the only valid values. d35196 2 a35197 2 ‘PARAM_AUTO_BOOLEAN’ The value has three possible states: true, false, and ‘auto’. In d35199 1 a35199 1 ‘auto’ is represented using ‘#:auto’. d35201 3 a35203 3 ‘PARAM_UINTEGER’ The value is an unsigned integer. The value of ‘#:unlimited’ should be interpreted to mean "unlimited", and the value of ‘0’ is d35206 1 a35206 1 ‘PARAM_ZINTEGER’ d35209 1 a35209 1 ‘PARAM_ZUINTEGER’ d35212 3 a35214 3 ‘PARAM_ZUINTEGER_UNLIMITED’ The value is an integer in the range ‘[0, INT_MAX]’. The value of ‘#:unlimited’ means "unlimited", the value of ‘-1’ is reserved and d35217 1 a35217 1 ‘PARAM_STRING’ d35219 1 a35219 1 escape sequences, such as ‘\t’, ‘\f’, and octal escapes, are d35223 1 a35223 1 ‘PARAM_STRING_NOESCAPE’ d35227 2 a35228 2 ‘PARAM_OPTIONAL_FILENAME’ The value is a either a filename (a string), or ‘#f’. d35230 1 a35230 1 ‘PARAM_FILENAME’ d35232 1 a35232 1 ‘PARAM_STRING_NOESCAPE’, but uses file names for completion. d35234 1 a35234 1 ‘PARAM_ENUM’ d35241 1 a35241 1 parameter objects (*note (guile)Parameters::). d35249 1 a35249 1 A program space, or “progspace”, represents a symbolic view of an d35254 1 a35254 1 Each progspace is represented by an instance of the ‘’ d35258 1 a35258 1 ‘(gdb)’ module: d35261 2 a35262 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d35265 2 a35266 2 Return ‘#t’ if PROGSPACE is valid, ‘#f’ if not. A ‘’ object can become invalid if the program it d35272 1 a35272 1 ‘#f’. *Note Inferiors Connections and Programs::. d35279 3 a35281 3 the name of the file passed as the argument to the ‘file’ or ‘symbol-file’ commands. If the program space does not have an associated file name, then ‘#f’ is returned. This occurs, for d35284 1 a35284 1 A ‘gdb:invalid-object-error’ exception is thrown if PROGSPACE is d35288 3 a35290 3 Return the list of objfiles of PROGSPACE. The order of objfiles in the result is arbitrary. Each element is an object of type ‘’. *Note Objfiles In Guile::. d35292 1 a35292 1 A ‘gdb:invalid-object-error’ exception is thrown if PROGSPACE is d35297 1 a35297 1 an object of type ‘’. *Note Guile Pretty d35302 1 a35302 1 Set the list of registered ‘’ objects for d35314 3 a35316 3 libraries used by the inferior, and any separate debug info files (*note Separate Debug Files::). GDB calls these symbol-containing files “objfiles”. d35318 1 a35318 1 Each objfile is represented as an object of type ‘’. d35320 1 a35320 1 The following objfile-related procedures are provided by the ‘(gdb)’ d35324 2 a35325 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d35328 1 a35328 1 Return ‘#t’ if OBJFILE is valid, ‘#f’ if not. A ‘’ d35330 1 a35330 1 loaded in GDB any longer. All other ‘’ procedures d35339 2 a35340 2 Return the ‘’ that this object file lives in. *Note Progspaces In Guile::, for more on progspaces. d35343 1 a35343 1 Return the list of registered ‘’ objects for d35347 1 a35347 1 Set the list of registered ‘’ objects for d35349 2 a35350 2 ‘’ objects. *Note Guile Pretty Printing API::, for more information. d35356 1 a35356 1 objfile, this function returns ‘#f’. d35368 2 a35369 2 (*note Stack frames: Frames.). The ‘’ class represents a frame in the stack. A ‘’ object is only valid while its d35371 2 a35372 2 an invalid frame object, GDB will throw a ‘gdb:invalid-object’ exception (*note Guile Exception Handling::). d35374 2 a35375 2 Two ‘’ objects can be compared for equality with the ‘equal?’ function, like: d35380 1 a35380 1 The following frame-related procedures are provided by the ‘(gdb)’ d35384 2 a35385 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d35388 1 a35388 1 Returns ‘#t’ if FRAME is valid, ‘#f’ if not. A frame object can d35390 3 a35392 2 the inferior. All ‘’ procedures will throw an exception if the frame is invalid at the time the procedure is called. d35395 1 a35395 1 Return the function name of FRAME, or ‘#f’ if it can't be obtained. d35398 1 a35398 1 Return the ‘’ object corresponding to FRAME's d35404 1 a35404 1 ‘NORMAL_FRAME’ d35407 1 a35407 1 ‘DUMMY_FRAME’ d35411 1 a35411 1 ‘INLINE_FRAME’ d35413 1 a35413 1 inlined into a ‘NORMAL_FRAME’ that is older than this one. d35415 1 a35415 1 ‘TAILCALL_FRAME’ d35418 1 a35418 1 ‘SIGTRAMP_FRAME’ d35422 1 a35422 1 ‘ARCH_FRAME’ d35425 2 a35426 2 ‘SENTINEL_FRAME’ This is like ‘NORMAL_FRAME’, but it is only used for the d35432 2 a35433 2 ‘unwind-stop-reason-string’ to convert the value returned by this function to a string. The value can be one of: d35435 1 a35435 1 ‘FRAME_UNWIND_NO_REASON’ d35438 1 a35438 1 ‘FRAME_UNWIND_NULL_ID’ d35441 1 a35441 1 ‘FRAME_UNWIND_OUTERMOST’ d35444 1 a35444 1 ‘FRAME_UNWIND_UNAVAILABLE’ d35448 1 a35448 1 ‘FRAME_UNWIND_INNER_ID’ d35453 1 a35453 1 ‘FRAME_UNWIND_SAME_ID’ d35460 1 a35460 1 ‘FRAME_UNWIND_NO_SAVED_PC’ d35464 1 a35464 1 ‘FRAME_UNWIND_MEMORY_ERROR’ d35468 1 a35468 1 ‘FRAME_UNWIND_FIRST_ERROR’ d35484 1 a35484 1 Return the frame's code block as a ‘’ object. *Note d35488 3 a35490 3 Return the symbol for the function corresponding to this frame as a ‘’ object, or ‘#f’ if there isn't one. *Note Symbols In Guile::. d35499 1 a35499 1 Return the frame's ‘’ (symtab and line) object. *Note d35504 1 a35504 1 string, like ‘pc’. d35511 2 a35512 2 given as a string or a ‘’ object, and BLOCK must be a ‘’ object. d35528 1 a35528 1 ‘frame-unwind-stop-reason’ procedure above in this section). d35538 1 a35538 1 represented individually in Guile as an object of type ‘’. d35541 1 a35541 1 A frame has a block. Please see *note Frames In Guile::, for a more d35544 2 a35545 2 The outermost block is known as the “global block”. The global block typically holds public global variables and functions. d35547 1 a35547 1 The block nested just inside the global block is the “static block”. d35582 1 a35582 1 The following block-related procedures are provided by the ‘(gdb)’ d35586 2 a35587 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d35590 6 a35595 6 Returns ‘#t’ if ‘’ BLOCK is valid, ‘#f’ if not. A block object can become invalid if the block it refers to doesn't exist anymore in the inferior. All other ‘’ methods will throw an exception if it is invalid at the time the procedure is called. The block's validity is also checked during iteration over symbols of the block. d35598 1 a35598 1 Return the start address of ‘’ BLOCK. d35601 1 a35601 1 Return the end address of ‘’ BLOCK. d35604 2 a35605 2 Return the name of ‘’ BLOCK represented as a ‘’ object. If the block is not named, then ‘#f’ is d35614 2 a35615 2 Return the block containing ‘’ BLOCK. If the parent block does not exist, then ‘#f’ is returned. d35618 1 a35618 1 Return the global block associated with ‘’ BLOCK. d35621 1 a35621 1 Return the static block associated with ‘’ BLOCK. d35624 2 a35625 2 Return ‘#t’ if ‘’ BLOCK is a global block. Otherwise return ‘#f’. d35628 2 a35629 2 Return ‘#t’ if ‘’ BLOCK is a static block. Otherwise return ‘#f’. d35633 1 a35633 1 ‘’ BLOCK. d35636 1 a35636 1 Return an object of type ‘’ that will iterate over d35644 2 a35645 2 This object would be obtained from the ‘progress’ element of the ‘’ object returned by ‘make-block-symbols-iterator’. d35648 1 a35648 1 Return the innermost ‘’ containing the given PC value. d35650 1 a35650 1 function will return ‘#f’. d35658 3 a35660 3 GDB represents every variable, function and type as an entry in a symbol table. *Note Examining the Symbol Table: Symbols. Guile represents these symbols in GDB with the ‘’ object. d35662 1 a35662 1 The following symbol-related procedures are provided by the ‘(gdb)’ d35666 2 a35667 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35670 5 a35674 5 Return ‘#t’ if the ‘’ object is valid, ‘#f’ if not. A ‘’ object can become invalid if the symbol it refers to does not exist in GDB any longer. All other ‘’ procedures will throw an exception if it is invalid at the time the procedure is called. d35677 2 a35678 2 Return the type of SYMBOL or ‘#f’ if no type is recorded. The result is an object of type ‘’. *Note Types In Guile::. d35682 1 a35682 1 object of type ‘’. *Note Symbol Tables In Guile::. d35697 1 a35697 1 either ‘name’ or ‘linkage_name’, depending on whether the user d35703 1 a35703 1 defined in the ‘(gdb)’ module and described later in this chapter. d35706 2 a35707 2 Return ‘#t’ if evaluating SYMBOL's value requires a frame (*note Frames In Guile::) and ‘#f’ otherwise. Typically, local variables d35711 2 a35712 2 Return ‘#t’ if SYMBOL is an argument of a function. Otherwise return ‘#f’. d35715 1 a35715 1 Return ‘#t’ if SYMBOL is a constant. Otherwise return ‘#f’. d35718 2 a35719 2 Return ‘#t’ if SYMBOL is a function or a method. Otherwise return ‘#f’. d35722 1 a35722 1 Return ‘#t’ if SYMBOL is a variable. Otherwise return ‘#f’. d35725 1 a35725 1 Compute the value of SYMBOL, as a ‘’. For functions, d35737 4 a35740 4 NAME is the name of the symbol. It must be a string. The optional BLOCK argument restricts the search to symbols visible in that BLOCK. The BLOCK argument must be a ‘’ object. If omitted, the block for the current frame is used. The optional d35742 1 a35742 1 DOMAIN argument must be a domain constant defined in the ‘(gdb)’ d35746 4 a35749 4 ‘’ object or ‘#f’ if the symbol is not found. If the symbol is found, the second element is ‘#t’ if the symbol is a field of a method's object (e.g., ‘this’ in C++), otherwise it is ‘#f’. If the symbol is not found, the second element is ‘#f’. d35755 4 a35758 4 NAME is the name of the symbol. It must be a string. The optional DOMAIN argument restricts the search to the domain type. The DOMAIN argument must be a domain constant defined in the ‘(gdb)’ module and described later in this chapter. d35760 1 a35760 1 The result is a ‘’ object or ‘#f’ if the symbol is not d35763 2 a35764 2 The available domain categories in ‘’ are represented as constants in the ‘(gdb)’ module: d35766 1 a35766 1 ‘SYMBOL_UNDEF_DOMAIN’ d35768 2 a35769 2 following domains apply. This usually indicates an error either in the symbol information or in GDB's handling of symbols. d35771 1 a35771 1 ‘SYMBOL_VAR_DOMAIN’ d35775 1 a35775 1 ‘SYMBOL_FUNCTION_DOMAIN’ d35778 1 a35778 1 ‘SYMBOL_TYPE_DOMAIN’ d35780 3 a35782 3 tag (the name appearing after a ‘struct’, ‘union’, or ‘enum’ keyword) will not appear here; in other languages, all types are in this domain. d35784 1 a35784 1 ‘SYMBOL_STRUCT_DOMAIN’ d35789 2 a35790 2 Here ‘type_one’ will be in ‘SYMBOL_STRUCT_DOMAIN’, but ‘type_two’ will be in ‘SYMBOL_TYPE_DOMAIN’. d35792 1 a35792 1 ‘SYMBOL_LABEL_DOMAIN’ d35795 3 a35797 3 ‘SYMBOL_VARIABLES_DOMAIN’ This domain holds a subset of the ‘SYMBOLS_VAR_DOMAIN’; it contains everything minus functions and types. d35799 1 a35799 1 ‘SYMBOL_FUNCTIONS_DOMAIN’ d35802 1 a35802 1 ‘SYMBOL_TYPES_DOMAIN’ d35805 2 a35806 2 The available address class categories in ‘’ are represented as constants in the ‘gdb’ module: d35812 3 a35814 3 each named after one of the preceding constants, but with the ‘SEARCH’ prefix replacing the ‘SYMBOL’ prefix; for example, ‘SEARCH_LABEL_DOMAIN’. These may be or'd together to form a search d35817 1 a35817 1 ‘SYMBOL_LOC_UNDEF’ d35821 1 a35821 1 ‘SYMBOL_LOC_CONST’ d35824 1 a35824 1 ‘SYMBOL_LOC_STATIC’ d35827 1 a35827 1 ‘SYMBOL_LOC_REGISTER’ d35830 1 a35830 1 ‘SYMBOL_LOC_ARG’ d35834 1 a35834 1 ‘SYMBOL_LOC_REF_ARG’ d35836 1 a35836 1 ‘LOC_ARG’ except that the value's address is stored at the offset, d35839 4 a35842 4 ‘SYMBOL_LOC_REGPARM_ADDR’ Value is a specified register. Just like ‘LOC_REGISTER’ except the register holds the address of the argument instead of the argument itself. d35844 1 a35844 1 ‘SYMBOL_LOC_LOCAL’ d35847 2 a35848 2 ‘SYMBOL_LOC_TYPEDEF’ Value not used. Symbols in the domain ‘SYMBOL_STRUCT_DOMAIN’ all d35851 1 a35851 1 ‘SYMBOL_LOC_BLOCK’ d35854 1 a35854 1 ‘SYMBOL_LOC_CONST_BYTES’ d35857 4 a35860 4 ‘SYMBOL_LOC_UNRESOLVED’ Value is at a fixed address, but the address of the variable has to be determined from the minimal symbol table whenever the variable is referenced. d35862 1 a35862 1 ‘SYMBOL_LOC_OPTIMIZED_OUT’ d35865 1 a35865 1 ‘SYMBOL_LOC_COMPUTED’ d35874 5 a35878 4 Access to symbol table data maintained by GDB on the inferior is exposed to Guile via two objects: ‘’ (symtab-and-line) and ‘’. Symbol table and line data for a frame is returned from the ‘frame-find-sal’ ‘’ procedure. *Note Frames In Guile::. d35880 1 a35880 1 For more information on GDB's symbol table management, see *note d35883 1 a35883 1 The following symtab-related procedures are provided by the ‘(gdb)’ d35887 2 a35888 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35891 5 a35895 5 Return ‘#t’ if the ‘’ object is valid, ‘#f’ if not. A ‘’ object becomes invalid when the symbol table it refers to no longer exists in GDB. All other ‘’ procedures will throw an exception if it is invalid at the time the procedure is called. d35916 1 a35916 1 ‘(gdb)’ module: d35919 2 a35920 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35923 4 a35926 4 Return ‘#t’ if SAL is valid, ‘#f’ if not. A ‘’ object becomes invalid when the Symbol table object it refers to no longer exists in GDB. All other ‘’ procedures will throw an exception if it is invalid at the time the procedure is called. d35929 1 a35929 1 Return the symbol table object (‘’) for SAL. d35941 4 a35944 4 Return the ‘’ object corresponding to the PC value. If an invalid value of PC is passed as an argument, then the ‘symtab’ and ‘line’ attributes of the returned ‘’ object will be ‘#f’ and 0 respectively. d35953 3 a35955 3 ‘’. New breakpoints can be created with the ‘make-breakpoint’ Guile function, and then added to GDB with the ‘register-breakpoint!’ Guile function. This two-step approach is taken d35957 1 a35957 1 ‘make-breakpoint’. d35963 1 a35963 1 ‘(gdb)’ module: d35969 8 a35976 8 of the breakpoint, or an expression that defines a watchpoint. The contents can be any location recognized by the ‘break’ command, or in the case of a watchpoint, by the ‘watch’ command. The breakpoint is initially marked as ‘invalid’. The breakpoint is not usable until it has been registered with GDB with ‘register-breakpoint!’, at which point it becomes ‘valid’. The result is the ‘’ object representing the d35980 2 a35981 2 can be either ‘BP_BREAKPOINT’ or ‘BP_WATCHPOINT’, and defaults to ‘BP_BREAKPOINT’. d35984 2 a35985 2 create, if TYPE is ‘BP_WATCHPOINT’. If a watchpoint class is not provided, it is assumed to be a ‘WP_WRITE’ class. d35989 2 a35990 2 when registered, nor will it be listed in the output from ‘info breakpoints’ (but will be listed with the ‘maint info breakpoints’ d35995 3 a35997 3 breakpoint. Temporary breakpoints are deleted after they have been hit, after which the Guile breakpoint is no longer usable (although it may be re-registered with ‘register-breakpoint!’). d36001 4 a36004 4 changed from ‘BP_WATCHPOINT’ to ‘BP_HARDWARE_WATCHPOINT’ for ‘WP_WRITE’, ‘BP_READ_WATCHPOINT’ for ‘WP_READ’, and ‘BP_ACCESS_WATCHPOINT’ for ‘WP_ACCESS’. If not successful, the type of the watchpoint is left as ‘WP_WATCHPOINT’. d36007 1 a36007 1 ‘gdb’ module: d36009 1 a36009 1 ‘BP_BREAKPOINT’ d36012 1 a36012 1 ‘BP_WATCHPOINT’ d36015 1 a36015 1 ‘BP_HARDWARE_WATCHPOINT’ d36019 1 a36019 1 ‘BP_READ_WATCHPOINT’ d36023 1 a36023 1 ‘BP_ACCESS_WATCHPOINT’ d36027 1 a36027 1 ‘BP_CATCHPOINT’ d36031 2 a36032 2 The available watchpoint types are represented by constants defined in the ‘(gdb)’ module: d36034 1 a36034 1 ‘WP_READ’ d36037 1 a36037 1 ‘WP_WRITE’ d36040 1 a36040 1 ‘WP_ACCESS’ d36043 1 d36045 1 a36045 1 Add BREAKPOINT, a ‘’ object, to GDB's list of d36047 1 a36047 1 ‘make-breakpoint’. One cannot register breakpoints that have been d36049 1 a36049 1 becomes ‘valid’. It is an error to register an already registered d36057 1 a36057 1 If BREAKPOINT was created from Guile with ‘make-breakpoint’ it may d36063 1 a36063 1 ‘’ object. d36066 1 a36066 1 Return ‘#t’ if OBJECT is a ‘’ object, and ‘#f’ d36070 4 a36073 4 Return ‘#t’ if BREAKPOINT is valid, ‘#f’ otherwise. Breakpoints created with ‘make-breakpoint’ are marked as invalid until they are registered with GDB with ‘register-breakpoint!’. A ‘’ object can become invalid if the user deletes d36084 1 a36084 1 Return ‘#t’ if the breakpoint was created as a temporary d36087 1 a36087 1 other than ‘breakpoint-valid?’ and ‘register-breakpoint!’, will d36096 2 a36097 2 Return ‘#t’ if the breakpoint is visible to the user when hit, or when the ‘info breakpoints’ command is run. Otherwise return ‘#f’. d36102 1 a36102 1 is, it is a watchpoint) return ‘#f’. d36107 1 a36107 1 breakpoint is not a watchpoint) return ‘#f’. d36110 1 a36110 1 Return ‘#t’ if the breakpoint is enabled, and ‘#f’ otherwise. d36113 2 a36114 2 Set the enabled state of BREAKPOINT to FLAG. If flag is ‘#f’ it is disabled, otherwise it is enabled. d36117 1 a36117 1 Return ‘#t’ if the breakpoint is silent, and ‘#f’ otherwise. d36120 2 a36121 2 the first command is ‘silent’. This is not reported by the ‘silent’ attribute. d36124 1 a36124 1 Set the silent state of BREAKPOINT to FLAG. If flag is ‘#f’ the d36148 1 a36148 1 ‘#f’, the breakpoint is no longer thread-specific. d36151 3 a36153 3 If the breakpoint is Ada task-specific, return the Ada task id. If the breakpoint is not task-specific (or the underlying language is not Ada), return ‘#f’. d36156 1 a36156 1 Set the Ada task of BREAKPOINT to TASK. If set to ‘#f’, the d36161 1 a36161 1 is a string. If there is no condition, return ‘#f’. d36165 1 a36165 1 string. If set to ‘#f’ then the breakpoint becomes unconditional. d36169 1 a36169 1 ‘set-breakpoint-stop!’ below in this section. d36173 5 a36177 5 takes one argument: the object. If this predicate is set to a procedure then it is invoked whenever the inferior reaches this breakpoint. If it returns ‘#t’, or any non-‘#f’ value, then the inferior is stopped, otherwise the inferior will continue. d36180 4 a36183 4 ‘stop’ predicate, each one will be called regardless of the return status of the previous. This ensures that all ‘stop’ predicates have a chance to execute at that location. In this scenario if one of the methods returns ‘#t’ but the others return ‘#f’, the d36189 2 a36190 2 As a general rule, you should not alter any data within GDB or the inferior at this time. d36192 1 a36192 1 Example ‘stop’ implementation: d36202 1 a36202 1 Return the commands attached to BREAKPOINT as a string, or ‘#f’ if d36211 1 a36211 1 A “lazy string” is a string whose contents is not retrieved or encoded d36214 3 a36216 3 A ‘’ is represented in GDB as an ‘address’ that points to a region of memory, an ‘encoding’ that will be used to encode that region of memory, and a ‘length’ to delimit the region of memory d36218 5 a36222 5 ‘’ and a string wrapped within a ‘’ is that a ‘’ will be treated differently by GDB when printing. A ‘’ is retrieved and encoded during printing, while a ‘’ wrapping a string is immediately retrieved and encoded on creation. d36225 1 a36225 1 ‘(gdb)’ module: d36228 2 a36229 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d36242 2 a36243 2 an empty string, then GDB will select the most appropriate encoding when the string is printed. d36248 1 a36248 1 the lazy string's character type, use ‘type-target-type’. *Note d36252 1 a36252 1 Convert the ‘’ to a ‘’. This value d36255 1 a36255 1 ‘’. d36264 2 a36265 2 its various computations. An architecture is represented by an instance of the ‘’ class. d36268 1 a36268 1 ‘(gdb)’ module: d36271 2 a36272 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d36275 1 a36275 1 Return the current architecture as a ‘’ object. d36278 1 a36278 1 Return the name (string value) of ‘’ ARCH. d36281 1 a36281 1 Return name of target character set of ‘’ ARCH. d36284 1 a36284 1 Return name of target wide character set of ‘’ ARCH. d36286 2 a36287 2 Each architecture provides a set of predefined types, obtained by the following functions. d36290 1 a36290 1 Return the ‘’ object for a ‘void’ type of architecture d36294 1 a36294 1 Return the ‘’ object for a ‘char’ type of architecture d36298 1 a36298 1 Return the ‘’ object for a ‘short’ type of architecture d36302 1 a36302 1 Return the ‘’ object for an ‘int’ type of architecture d36306 1 a36306 1 Return the ‘’ object for a ‘long’ type of architecture d36310 1 a36310 1 Return the ‘’ object for a ‘signed char’ type of d36314 1 a36314 1 Return the ‘’ object for an ‘unsigned char’ type of d36318 1 a36318 1 Return the ‘’ object for an ‘unsigned short’ type of d36322 1 a36322 1 Return the ‘’ object for an ‘unsigned int’ type of d36326 1 a36326 1 Return the ‘’ object for an ‘unsigned long’ type of d36330 1 a36330 1 Return the ‘’ object for a ‘float’ type of architecture d36334 1 a36334 1 Return the ‘’ object for a ‘double’ type of architecture d36338 1 a36338 1 Return the ‘’ object for a ‘long double’ type of d36342 1 a36342 1 Return the ‘’ object for a ‘bool’ type of architecture d36346 1 a36346 1 Return the ‘’ object for a ‘long long’ type of d36350 1 a36350 1 Return the ‘’ object for an ‘unsigned long long’ type of d36354 1 a36354 1 Return the ‘’ object for an ‘int8’ type of architecture d36358 1 a36358 1 Return the ‘’ object for a ‘uint8’ type of architecture d36362 1 a36362 1 Return the ‘’ object for an ‘int16’ type of architecture d36366 1 a36366 1 Return the ‘’ object for a ‘uint16’ type of architecture d36370 1 a36370 1 Return the ‘’ object for an ‘int32’ type of architecture d36374 1 a36374 1 Return the ‘’ object for a ‘uint32’ type of architecture d36378 1 a36378 1 Return the ‘’ object for an ‘int64’ type of architecture d36382 1 a36382 1 Return the ‘’ object for a ‘uint64’ type of architecture d36397 2 a36398 2 disassembler can take a Guile port as input, allowing one to disassemble from any source, and not just target memory. d36406 1 a36406 1 from. If PORT is ‘#f’ then bytes are read from target memory. d36410 1 a36410 1 specifies a ‘bytevector’ and you want the bytevector to be d36429 9 a36437 9 instructions whose start address falls in the closed memory address interval from START-PC to (START-PC + SIZE - 1) are returned. If SIZE is not specified, but COUNT is specified, then COUNT number of instructions starting from the address START-PC are returned. If COUNT is not specified but SIZE is specified, then all instructions whose start address falls in the closed memory address interval from START-PC to (START-PC + SIZE - 1) are returned. If neither SIZE nor COUNT are specified, then a single instruction at START-PC is returned. d36442 1 a36442 1 ‘address’ d36446 1 a36446 1 ‘asm’ d36450 1 a36450 1 specified by the current CLI variable ‘disassembly-flavor’. d36453 1 a36453 1 ‘length’ d36457 1 d36474 1 a36474 1 Return ‘#t’ if OBJECT is a GDB stdio port. Otherwise return ‘#f’. d36482 1 a36482 1 GDB provides a ‘port’ interface to target memory. This allows Guile d36484 1 a36484 1 functionality. The main routine is ‘open-memory’ which returns a port d36491 6 a36496 6 standard mode argument to Guile port open routines, except that the ‘"a"’ and ‘"l"’ modes are not supported. *Note (guile)File Ports::. The ‘"b"’ (binary) character may be present, but is ignored: memory ports are binary only. If ‘"0"’ is appended then the port is marked as unbuffered. The default is ‘"r"’, read-only and buffered. d36502 2 a36503 2 [0,SIZE) can be accessed. If both are specified, all memory in the rane [START,START+SIZE) can be accessed. d36506 2 a36507 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d36510 2 a36511 2 Return the range of ‘’ MEMORY-PORT as a list of two elements: ‘(start end)’. The range is START to END inclusive. d36514 1 a36514 1 Return the size of the read buffer of ‘’ d36521 1 a36521 1 Set the size of the read buffer of ‘’ MEMORY-PORT d36525 2 a36526 2 GDB is built with Guile 2.2 or later, you can call ‘setvbuf’ instead (*note ‘setvbuf’: (guile)Buffering.). d36529 1 a36529 1 Return the size of the write buffer of ‘’ d36537 2 a36538 2 Set the size of the write buffer of ‘’ MEMORY-PORT to SIZE. The result is unspecified. d36541 1 a36541 1 GDB is built with Guile 2.2 or later, you can call ‘setvbuf’ d36544 1 a36544 1 A memory port is closed like any other port, with ‘close-port’. d36546 1 a36546 1 Combined with Guile's ‘bytevectors’, memory ports provide a lot of d36572 3 a36574 3 over the set of program symbols without having to first construct a list of all of them. A useful contribution would be to add support for SRFI 41 and SRFI 45. d36577 1 a36577 1 A ‘’ object is constructed with the ‘make-iterator’ d36584 4 a36587 4 ‘(end-of-iteration)’, and may be tested with the ‘end-of-iteration?’ predicate. The result of ‘(end-of-iteration)’ is chosen so that it is not otherwise used by the ‘(gdb)’ module. If you are using ‘’ in your own code it is your d36604 2 a36605 2 Here is a slightly more realistic example, which computes a list of all the functions in ‘my-global-block’. d36615 2 a36616 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d36619 2 a36620 2 Return the first argument that was passed to ‘make-iterator’. This is the object being iterated over. d36630 4 a36633 4 ‘make-iterator’, passing it one argument, the ‘’ object. The result is either the next element in the iteration, or an end marker as implemented by the ‘next!’ procedure. By convention the end marker is the result of ‘(end-of-iteration)’. d36639 2 a36640 2 Return ‘#t’ if OBJECT is the end of iteration marker. Otherwise return ‘#f’. d36642 2 a36643 2 These functions are provided by the ‘(gdb iterator)’ module to assist in using iterators. d36646 1 a36646 1 Return a ‘’ object that will iterate over LIST. d36664 2 a36665 2 Run ITERATOR until the result of ‘(pred element)’ is true and return that as the result. Otherwise return ‘#f’. d36673 1 a36673 1 When a new object file is read (for example, due to the ‘file’ command, d36675 2 a36676 2 Guile support scripts in two ways: ‘OBJFILE-gdb.scm’ and the ‘.debug_gdb_scripts’ section. *Note Auto-loading extensions::. d36684 1 a36684 1 ‘set auto-load guile-scripts [on|off]’ d36687 1 a36687 1 ‘show auto-load guile-scripts’ d36690 1 a36690 1 ‘info auto-load guile-scripts [REGEXP]’ d36694 1 a36694 1 the ‘.debug_gdb_scripts’ section and were not found. This is d36710 3 a36712 3 When reading an auto-loaded file, GDB sets the “current objfile”. This is available via the ‘current-objfile’ procedure (*note Objfiles In Guile::). This can be useful for registering objfile-specific d36742 3 a36744 3 Add PRINTER to the front of the list of pretty-printers for OBJECT. The OBJECT must either be a ‘’ object, or ‘#f’ in which case PRINTER is added to the global list of printers. d36748 1 a36748 1 The OBJECT must either be a ‘’ object, or ‘#f’ in d36758 1 a36758 1 ‘’ objects. d36784 3 a36786 3 Return ‘#t’ if TYPE, assumed to be a type with fields (e.g., a structure or union), has field FIELD. Otherwise return ‘#f’. This searches baseclasses, whereas ‘type-has-field?’ does not. d36789 2 a36790 2 Return a Guile hash table produced from ENUM-TYPE. Elements in the hash table are referenced with ‘hashq-ref’. d36799 6 a36804 6 new object file is read (for example, due to the ‘file’ command, or because the inferior has loaded a shared library): ‘OBJFILE-gdb.EXT’ (*note The ‘OBJFILE-gdb.EXT’ file: objfile-gdbdotext file.) and the ‘.debug_gdb_scripts’ section of modern file formats like ELF (*note The ‘.debug_gdb_scripts’ section: dotdebug_gdb_scripts section.). For a discussion of the differences between these two approaches see *note d36811 1 a36811 1 scripts can be printed. See the ‘auto-loading’ section of each d36813 1 a36813 1 *note Auto-loading sequences::. For Python files see *note Python d36817 1 a36817 1 configured ‘auto-load safe-path’ (*note Auto-loading safe path::). d36821 2 a36822 2 * objfile-gdbdotext file:: The ‘OBJFILE-gdb.EXT’ file * dotdebug_gdb_scripts section:: The ‘.debug_gdb_scripts’ section d36828 1 a36828 1 23.5.1 The ‘OBJFILE-gdb.EXT’ file d36832 3 a36834 3 ‘OBJFILE-gdb.EXT’ (we call it SCRIPT-NAME below), where OBJFILE is the object file's name and where EXT is the file extension for the extension language: d36836 1 a36836 1 ‘OBJFILE-gdb.gdb’ d36838 2 a36839 1 ‘OBJFILE-gdb.py’ d36841 2 a36842 1 ‘OBJFILE-gdb.scm’ d36846 4 a36849 4 absolute, following all symlinks, and resolving ‘.’ and ‘..’ components, and appending the ‘-gdb.EXT’ suffix. If this file exists and is readable, GDB will evaluate it as a script in the specified extension language. d36853 3 a36855 3 the drive letter of the executable's leading directories is converted to a one-letter subdirectory, i.e. ‘d:/usr/bin/’ is converted to ‘/d/usr/bin/’, because Windows filesystems disallow colons in file d36859 1 a36859 1 ‘auto-load safe-path’ (*note Auto-loading safe path::). d36861 2 a36862 2 For object files using ‘.exe’ suffix GDB tries to load first the scripts normally according to its ‘.exe’ filename. But if no scripts d36864 1 a36864 1 without its ‘.exe’ suffix. This ‘.exe’ stripping is case insensitive d36868 1 a36868 1 ‘set auto-load scripts-directory [DIRECTORIES]’ d36871 1 a36871 1 (‘:’ on Unix, ‘;’ on MS-Windows and MS-DOS). d36874 1 a36874 1 ‘set auto-load safe-path’ (*note set auto-load safe-path::). d36876 3 a36878 3 This variable defaults to ‘$debugdir:$datadir/auto-load’. The default ‘set auto-load safe-path’ value can be also overridden by GDB configuration option ‘--with-auto-load-dir’. d36880 1 a36880 1 Any reference to ‘$debugdir’ will get replaced by d36882 4 a36885 4 reference to ‘$datadir’ will get replaced by DATA-DIRECTORY which is determined at GDB startup (*note Data Files::). ‘$debugdir’ and ‘$datadir’ must be placed as a directory component -- either alone or delimited by ‘/’ or ‘\’ directory separators, depending on the d36888 3 a36890 3 The list of directories uses path separator (‘:’ on GNU and Unix systems, ‘;’ on MS-Windows and MS-DOS) to separate directories, similarly to the ‘PATH’ environment variable. d36892 1 a36892 1 ‘show auto-load scripts-directory’ d36895 1 a36895 1 ‘add-auto-load-scripts-directory [DIRECTORIES...]’ d36901 3 a36903 3 GDB will load the associated script every time the corresponding OBJFILE is opened. So your ‘-gdb.EXT’ file should be careful to avoid errors if it is evaluated more than once. d36908 1 a36908 1 23.5.2 The ‘.debug_gdb_scripts’ section d36913 5 a36917 5 ‘.debug_gdb_scripts’. If this section exists, its contents is a list of null-terminated entries specifying scripts to load. Each entry begins with a non-null prefix byte that specifies the kind of entry, typically the extension language and whether the script is in a file or inlined in ‘.debug_gdb_scripts’. d36921 7 a36927 4 ‘SECTION_SCRIPT_ID_PYTHON_FILE = 1’ ‘SECTION_SCRIPT_ID_SCHEME_FILE = 3’ ‘SECTION_SCRIPT_ID_PYTHON_TEXT = 4’ ‘SECTION_SCRIPT_ID_SCHEME_TEXT = 6’ d36934 3 a36936 2 Specifying Source Directories: Source Path.), except that ‘$cdir’ is not searched, since the compilation directory is not relevant to scripts. d36938 1 a36938 1 File entries can be placed in section ‘.debug_gdb_scripts’ with, for d36950 1 a36950 1 For Guile scripts, replace ‘.byte 1’ with ‘.byte 3’. Then one can d36958 1 a36958 1 configured ‘auto-load safe-path’ (*note Auto-loading safe path::). d36962 1 a36962 1 and with the use of ‘"MS"’ attributes on the section, the linker will d36970 1 a36970 1 everything after the prefix byte and up to the first newline (‘0xa’) d36974 2 a36975 2 The name needs to be unique among all script names, as GDB executes each script only once based on its name. d36977 1 a36977 1 Here is an example from file ‘py-section-script.c’ in the GDB d36997 4 a37000 4 Loading of inlined scripts requires a properly configured ‘auto-load safe-path’ (*note Auto-loading safe path::). The path to specify in ‘auto-load safe-path’ is the path of the file containing the ‘.debug_gdb_scripts’ section. d37011 1 a37011 1 Benefits of the ‘-gdb.EXT’ way: d37013 1 a37013 1 • Can be used with file formats that don't support multiple sections. d37015 1 a37015 1 • Ease of finding scripts for public libraries. d37017 1 a37017 1 Scripts specified in the ‘.debug_gdb_scripts’ section are searched d37019 1 a37019 1 e.g., ‘libstdc++’, there typically isn't a source directory in d37022 1 a37022 1 • Doesn't require source code additions. d37024 1 a37024 1 Benefits of the ‘.debug_gdb_scripts’ way: d37026 1 a37026 1 • Works with static linking. d37028 1 a37028 1 Scripts for libraries done the ‘-gdb.EXT’ way require an objfile to d37032 1 a37032 1 executable's ‘-gdb.EXT’ script. d37034 1 a37034 1 • Works with classes that are entirely inlined. d37037 1 a37037 1 associated shared library to attach a ‘-gdb.EXT’ script to. d37039 1 a37039 1 • Scripts needn't be copied out of the source tree. d37043 1 a37043 1 install the ‘-gdb.EXT’ scripts in a place where GDB can find them d37045 1 a37045 1 ‘.debug_gdb_scripts’ section as relative paths, and add a path to d37055 2 a37056 2 generally do not interfere with each other. There are some things to be aware of, however. d37065 2 a37066 2 pretty-print a value), it tries each in turn until an extension language indicates it has performed the request (e.g., has returned the d37068 3 a37070 3 performing such requests: If an error happens while, for example, trying to pretty-print an object then the error is reported and any following extension languages are not tried. d37089 1 a37089 1 the ‘-i’ or ‘--interpreter’ startup options. Defined interpreters d37092 1 a37092 1 ‘console’ d37094 1 a37094 1 most often used interpreter with GDB. With no interpreter d37097 1 a37097 1 ‘dap’ d37099 4 a37102 3 Debugger Adapter Protocol. This protocol can be used by a debugger GUI or an IDE to communicate with GDB. This protocol is documented at . *Note d37106 2 a37107 2 ‘mi’ The newest GDB/MI interface (currently ‘mi3’). Used primarily by d37109 1 a37109 1 IDE. For more information, see *note The GDB/MI Interface: GDB/MI. d37111 1 a37111 1 ‘mi3’ d37114 1 a37114 1 ‘mi2’ d37117 1 d37120 1 a37120 1 console interpreter, simply use the ‘interpreter-exec’ command: d37127 1 a37127 1 Note that ‘interpreter-exec’ only changes the interpreter for the d37138 5 a37142 5 stdin/stdout/stderr redirected to that terminal, and then creating an MI interpreter running on a specified input/output device. The console interpreter created by GDB at startup handles commands the user types in the terminal widget, while the GUI controls and synchronizes state with GDB using the separate MI interpreter. d37144 2 a37145 2 To start a new secondary “user interface” running MI, use the ‘new-ui’ command: d37150 5 a37154 4 accepts the same values as the ‘interpreter-exec’ command. For example, ‘console’, ‘mi’, ‘mi2’, etc. The TTY parameter specifies the name of the bidirectional file the interpreter uses for input/output, usually the name of a pseudoterminal slave on Unix systems. For example: d37158 1 a37158 1 runs an MI interpreter on ‘/dev/pts/9’. d37166 2 a37167 2 The GDB Text User Interface (TUI) is a terminal interface which uses the ‘curses’ library to show the source file, the assembly output, the d37170 1 a37170 1 ‘curses’ library is available. d37172 1 a37172 1 The TUI mode is enabled by default when you invoke GDB as ‘gdb -tui’. d37174 3 a37176 3 various TUI commands and key bindings, such as ‘tui enable’ or ‘C-x C-a’. *Note TUI Commands: TUI Commands, and *note TUI Key Bindings: TUI Keys. d37211 1 a37211 1 highlighting the current line and marking it with a ‘>’ marker. By d37213 2 a37214 2 highlighted text, but you can enable it with the ‘set style tui-current-position on’ command. *Note Output Styling::. d37219 1 a37219 1 ‘B’ d37222 1 a37222 1 ‘b’ d37225 1 a37225 1 ‘H’ d37228 1 a37228 1 ‘h’ d37233 1 a37233 1 ‘+’ d37236 1 a37236 1 ‘-’ d37247 1 a37247 1 • source only, d37249 1 a37249 1 • assembly only, d37251 1 a37251 1 • source and assembly, d37253 1 a37253 1 • source and registers, or d37255 1 a37255 1 • assembly and registers. d37268 1 a37268 1 being debugged, this field is set to ‘No process’. d37277 1 a37277 1 counter, the string ‘??’ is displayed. d37280 2 a37281 2 Indicates the current line number for the selected frame. When the current line number is not known, the string ‘??’ is displayed. d37296 8 a37303 8 ‘C-x C-a’ ‘C-x a’ ‘C-x A’ Enter or leave the TUI mode. When leaving the TUI mode, the curses window management stops and GDB operates using its standard mode, writing on the terminal directly. When reentering the TUI mode, control is given back to the curses windows. The screen is then refreshed. d37306 1 a37306 1 ‘tui-switch-mode’. d37308 1 a37308 1 ‘C-x 1’ d37310 1 a37310 1 ‘source’ or ‘assembly’. When the TUI mode is not active, it will d37313 1 a37313 1 Think of this key binding as the Emacs ‘C-x 1’ binding. d37316 1 a37316 1 ‘tui-delete-other-windows’. d37318 1 a37318 1 ‘C-x 2’ d37320 2 a37321 2 layout already has two windows, the next layout with two windows is used. When a new layout is chosen, one window will always be d37324 1 a37324 1 Think of it as the Emacs ‘C-x 2’ binding. d37327 1 a37327 1 ‘tui-change-windows’. d37329 1 a37329 1 ‘C-x o’ d37334 1 a37334 1 Think of it as the Emacs ‘C-x o’ binding. d37337 1 a37337 1 ‘tui-other-window’. d37339 1 a37339 1 ‘C-x s’ d37343 1 a37343 1 This key binding uses the bindable Readline function ‘next-keymap’. d37365 1 a37365 1 ‘C-L’ d37370 3 a37372 3 window has the focus. When another window is active, you must use other readline key bindings such as ‘C-p’, ‘C-n’, ‘C-b’ and ‘C-f’ to control the command window. d37380 3 a37382 3 The TUI also provides a “SingleKey” mode, which binds several frequently used GDB commands to single keys. Type ‘C-x s’ to switch into this mode, where the following key bindings are used: d37384 1 a37384 1 ‘c’ d37387 1 a37387 1 ‘C’ d37390 1 a37390 1 ‘d’ d37393 1 a37393 1 ‘f’ d37396 1 a37396 1 ‘F’ d37399 1 a37399 1 ‘n’ d37402 1 a37402 1 ‘N’ d37405 2 a37406 2 ‘o’ nexti. The shortcut letter ‘o’ stands for "step Over". d37408 1 a37408 1 ‘O’ d37411 1 a37411 1 ‘q’ d37414 1 a37414 1 ‘r’ d37417 1 a37417 1 ‘s’ d37420 1 a37420 1 ‘S’ d37423 2 a37424 2 ‘i’ stepi. The shortcut letter ‘i’ stands for "step Into". d37426 1 a37426 1 ‘I’ d37429 1 a37429 1 ‘u’ d37432 1 a37432 1 ‘v’ d37435 1 a37435 1 ‘w’ d37442 2 a37443 2 restored. The only way to permanently leave this mode is by typing ‘q’ or ‘C-x s’. d37445 3 a37447 3 If GDB was built with Readline 8.0 or later, the TUI SingleKey keymap will be named ‘SingleKey’. This can be used in ‘.inputrc’ to add additional bindings to this keymap. d37462 3 a37464 3 mouse. However, on Unix terminals, you can typically press and hold the key on your keyboard to temporarily bypass GDB's TUI and access the terminal's native mouse copy/paste functionality (commonly, d37467 3 a37469 3 opposed to the TUI's buffer. Alternatively, to disable mouse support in the TUI entirely and give the terminal control over mouse clicks, turn off the ‘tui mouse-events’ setting (*note set tui mouse-events: d37486 1 a37486 1 Note that if GDB's ‘stdout’ is not connected to a terminal, or GDB d37492 1 a37492 1 ‘tui enable’ d37497 1 a37497 1 ‘tui disable’ d37500 1 a37500 1 ‘info win’ d37503 1 a37503 1 ‘tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT...]’ d37505 1 a37505 1 can be accessed using the ‘layout’ command (see below). d37507 2 a37508 2 Each WINDOW parameter is either the name of a window to display, or a window description. The windows will be displayed from top to d37512 4 a37515 4 ‘focus’ command (see below); additionally, the ‘status’ window can be specified. Note that, because it is of fixed height, the weight assigned to the status window is of no importance. It is conventional to use ‘0’ here. d37517 2 a37518 2 A window description looks a bit like an invocation of ‘tui new-layout’, and is of the form {[‘-horizontal’]WINDOW WEIGHT d37521 1 a37521 1 This specifies a sub-layout. If ‘-horizontal’ is given, the d37533 1 a37533 1 Here, the new layout is called ‘example’. It shows the source and d37546 2 a37547 2 source and assembly windows will be twice the height of the command window. d37549 2 a37550 2 ‘tui layout NAME’ ‘layout NAME’ d37554 1 a37554 1 using ‘tui new-layout’. d37558 1 a37558 1 ‘next’ d37561 1 a37561 1 ‘prev’ d37564 1 a37564 1 ‘src’ d37567 1 a37567 1 ‘asm’ d37570 1 a37570 1 ‘split’ d37573 3 a37575 3 ‘regs’ When in ‘src’ layout display the register, source, and command windows. When in ‘asm’ or ‘split’ layout display the d37578 2 a37579 2 ‘tui focus NAME’ ‘focus NAME’ d37583 1 a37583 1 ‘next’ d37586 1 a37586 1 ‘prev’ d37589 1 a37589 1 ‘src’ d37592 1 a37592 1 ‘asm’ d37595 1 a37595 1 ‘regs’ d37598 1 a37598 1 ‘cmd’ d37601 3 a37603 3 ‘tui refresh’ ‘refresh’ Refresh the screen. This is similar to typing ‘C-L’. d37605 1 a37605 1 ‘tui reg GROUP’ d37609 1 a37609 1 of register groups, as well as their order is target specific. The d37611 1 a37611 1 ‘next’ d37615 1 a37615 1 ‘prev’ d37620 1 a37620 1 ‘general’ d37622 2 a37623 1 ‘float’ d37625 2 a37626 1 ‘system’ d37628 2 a37629 1 ‘vector’ d37631 2 a37632 1 ‘all’ d37635 1 a37635 1 ‘update’ d37638 4 a37641 4 ‘tui window height NAME +COUNT’ ‘tui window height NAME -COUNT’ ‘winheight NAME +COUNT’ ‘winheight NAME -COUNT’ d37643 4 a37646 4 counts increase the height, while negative counts decrease it. The NAME parameter can be the name of any currently visible window. The names of the currently visible windows can be discovered using ‘info win’ (*note info win: info_win_command.). d37653 4 a37656 4 ‘tui window width NAME +COUNT’ ‘tui window width NAME -COUNT’ ‘winwidth NAME +COUNT’ ‘winwidth NAME -COUNT’ d37661 1 a37661 1 ‘info win’ (*note info win: info_win_command.). d37676 1 a37676 1 ‘set tui border-kind KIND’ d37679 1 a37679 1 ‘space’ d37682 2 a37683 2 ‘ascii’ Use ASCII characters ‘+’, ‘-’ and ‘|’ to draw the border. d37685 1 a37685 1 ‘acs’ d37690 2 a37691 2 ‘set tui border-mode MODE’ ‘set tui active-border-mode MODE’ d37695 1 a37695 1 ‘normal’ d37698 1 a37698 1 ‘standout’ d37701 1 a37701 1 ‘reverse’ d37704 1 a37704 1 ‘half’ d37707 1 a37707 1 ‘half-standout’ d37710 1 a37710 1 ‘bold’ d37713 1 a37713 1 ‘bold-standout’ d37716 1 a37716 1 ‘set tui tab-width NCHARS’ d37721 1 a37721 1 ‘set tui compact-source [on|off]’ d37727 1 a37727 1 ‘set tui mouse-events [on|off]’ d37732 1 a37732 1 ‘set debug tui [on|off]’ d37736 1 a37736 1 ‘show debug tui’ d37740 1 d37742 1 a37742 1 appropriate ‘set style’ commands. *Note Output Styling::. d37753 1 a37753 1 To use this interface, use the command ‘M-x gdb’ in Emacs. Give the d37761 1 a37761 1 • All "terminal" input and output goes through an Emacs buffer, d37772 3 a37774 3 interacting with your program. In particular, you can send signals the usual way--for example, ‘C-c C-c’ for an interrupt, ‘C-c C-z’ for a stop. d37776 1 a37776 1 • GDB displays source code through Emacs. d37779 1 a37779 1 source file for that frame and puts an arrow (‘=>’) at the left d37784 1 a37784 1 Explicit GDB ‘list’ or search commands still produce output as d37787 4 a37790 4 We call this “text command mode”. Emacs 22.1, and later, also uses a graphical mode, enabled by default, which provides further buffers that can control the execution and describe the state of your program. *Note (Emacs)GDB Graphical Interface::. d37792 1 a37792 1 If you specify an absolute file name when prompted for the ‘M-x gdb’ d37797 1 a37797 1 your environment's ‘PATH’ variable, but on some operating systems it d37807 4 a37810 4 By default, ‘M-x gdb’ calls the program called ‘gdb’. If you need to call GDB by a different name (for example, if you keep several configurations around, with different names) you can customize the Emacs variable ‘gud-gdb-command-name’ to run the one you want. d37815 1 a37815 1 ‘C-h m’ d37818 2 a37819 2 ‘C-c C-s’ Execute to another source line, like the GDB ‘step’ command; also d37822 1 a37822 1 ‘C-c C-n’ d37824 1 a37824 1 calls, like the GDB ‘next’ command. Then update the display window d37827 2 a37828 2 ‘C-c C-i’ Execute one instruction, like the GDB ‘stepi’ command; update d37831 1 a37831 1 ‘C-c C-f’ d37833 1 a37833 1 ‘finish’ command. d37835 2 a37836 2 ‘C-c C-r’ Continue execution of your program, like the GDB ‘continue’ d37839 4 a37842 3 ‘C-c <’ Go up the number of frames indicated by the numeric argument (*note Numeric Arguments: (Emacs)Arguments.), like the GDB ‘up’ command. d37844 1 a37844 1 ‘C-c >’ d37846 1 a37846 1 like the GDB ‘down’ command. d37848 2 a37849 2 In any source file, the Emacs command ‘C-x ’ (‘gud-break’) tells GDB to set a breakpoint on the source line point is on. d37851 1 a37851 1 In text command mode, if you type ‘M-x speedbar’, Emacs displays a d37855 1 a37855 1 buffer. Alternatively, click ‘Mouse-2’ to make the selected frame d37860 1 a37860 1 get it back is to type the command ‘f’ in the GDB buffer, to request a d37868 2 a37869 2 lines from the text, the line numbers that GDB knows cease to correspond properly with the code. d37872 1 a37872 1 in the Emacs manual (*note (Emacs)Debuggers::). a37879 27 * Menu: * GDB/MI General Design:: * GDB/MI Command Syntax:: * GDB/MI Compatibility with CLI:: * GDB/MI Development and Front Ends:: * GDB/MI Output Records:: * GDB/MI Simple Examples:: * GDB/MI Command Description Format:: * GDB/MI Breakpoint Commands:: * GDB/MI Catchpoint Commands:: * GDB/MI Program Context:: * GDB/MI Thread Commands:: * GDB/MI Ada Tasking Commands:: * GDB/MI Program Execution:: * GDB/MI Stack Manipulation:: * GDB/MI Variable Objects:: * GDB/MI Data Manipulation:: * GDB/MI Tracepoint Commands:: * GDB/MI Symbol Query:: * GDB/MI File Commands:: * GDB/MI Target Manipulation:: * GDB/MI File Transfer Commands:: * GDB/MI Ada Exceptions Commands:: * GDB/MI Support Commands:: * GDB/MI Miscellaneous Commands:: d37884 1 a37884 1 activated by specifying using the ‘--interpreter’ command line option d37892 3 a37894 3 Note that GDB/MI is still under construction, so some of the features described below are incomplete and subject to change (*note GDB/MI Development and Front Ends: GDB/MI Development and Front Ends.). d37901 1 a37901 1 • ‘|’ separates two alternatives. d37903 2 a37904 2 • ‘[ SOMETHING ]’ indicates that SOMETHING is optional: it may or may not be given. d37906 1 a37906 1 • ‘( GROUP )*’ means that GROUP inside the parentheses may repeat d37909 2 a37910 2 • ‘( GROUP )+’ means that GROUP inside the parentheses may repeat one or more times. d37912 1 a37912 1 • ‘( GROUP )’ means that GROUP inside the parentheses occurs exactly d37915 1 a37915 1 • ‘"STRING"’ means a literal STRING. d37950 10 a37959 10 Interaction of a GDB/MI frontend with GDB involves three parts--commands sent to GDB, responses to those commands and notifications. Each command results in exactly one response, indicating either successful completion of the command, or an error. For the commands that do not resume the target, the response contains the requested information. For the commands that resume the target, the response only indicates whether the target was successfully resumed. Notifications is the mechanism for reporting changes in the state of the target, or in GDB state, that cannot conveniently be associated with a command and reported as part of that command response. d37962 1 a37962 2 • Exec notifications. These are used to report changes in target d37965 4 a37968 4 commands, because one resume commands can result in multiple events in different threads. Also, quite some time may pass before any event happens in the target, while a frontend needs to know whether the resuming command itself was successfully executed. d37970 1 a37970 1 • Console output, and status notifications. Console output d37974 3 a37976 2 including this information in command response would mean no output is produced until the command is finished, which is undesirable. d37978 1 a37978 1 • General notifications. Commands may have various side effects on d37984 1 d37988 3 a37990 2 Therefore, whenever an MI command results in an error, we recommend that the frontend refreshes all the information shown in the user interface. d38014 2 a38015 2 single terminal, so no confusion is possible as to what thread and frame are the current ones. d38024 3 a38026 3 specify which thread and frame to operate on. To make it possible, each MI command accepts the ‘--thread’ and ‘--frame’ options, the value to each is GDB global identifier for thread and frame to operate on. d38033 5 a38037 5 hit. For another example, if the user issues the CLI ‘thread’ or ‘frame’ commands via the frontend, it is desirable to change the frontend's selection to the one specified by user. GDB communicates the suggestion to change current thread and frame using the ‘=thread-selected’ notification. d38040 1 a38040 1 frontends used the ‘-thread-select’ to execute commands in the right d38042 1 a38042 1 simplest way is for frontend to emit ‘-thread-select’ command before d38044 1 a38044 1 sent. The alternative approach is to suppress ‘-thread-select’ if the d38047 2 a38048 2 can be tricky. In particular, if the frontend sends several commands to GDB, and one of the commands changes the selected thread, then the d38051 1 a38051 1 add ‘-thread-select’ for all subsequent commands. No frontend is known d38053 1 a38053 1 ‘--thread’ and ‘--frame’ options. d38061 1 a38061 1 the ‘--language’ option. This option takes one argument, which is the d38068 3 a38070 3 The valid language names are the same names accepted by the ‘set language’ command (*note Manually::), excluding ‘auto’, ‘local’ or ‘unknown’. d38078 2 a38079 2 On some targets, GDB is capable of processing MI commands even while the target is running. This is called “asynchronous command execution” d38081 1 a38081 1 for asynchronous execution using the ‘-gdb-set mi-async 1’ command, d38085 1 a38085 1 enabled using the ‘-list-target-features’ command. d38087 1 a38087 1 ‘-gdb-set mi-async [on|off]’ d38090 2 a38091 2 When ‘off’, which is the default, MI execution commands (e.g., ‘-exec-continue’) are foreground commands, and GDB waits for the d38094 2 a38095 2 When ‘on’, MI execution commands are background execution commands (e.g., ‘-exec-continue’ becomes the equivalent of the ‘c&’ CLI d38099 1 a38099 1 ‘-gdb-show mi-async’ d38103 1 a38103 1 ‘target-async’ instead of ‘mi-async’, and it had the effect of both d38120 9 a38128 9 that even commands that operate on global state, such as ‘print’, ‘set’, and breakpoint commands, still access the target in the context of a specific thread, so frontend should try to find a stopped thread and perform the operation on that thread (using the ‘--thread’ option). Which commands will work in the context of a running thread is highly target dependent. However, the two commands ‘-exec-interrupt’, to stop a thread, and ‘-thread-info’, to find the state of a thread, will always work. d38144 1 a38144 1 accept the ‘--thread’ option do not need to know what process that d38146 3 a38148 3 additional ‘--process’ option, nor an notion of the current process in the MI interface. The only strictly new feature that is required is the ability to find how the threads are grouped into processes. d38152 1 a38152 1 “thread group”. Thread group is a collection of threads and other d38154 6 a38159 5 and may have additional attributes specific to the type. A new command, ‘-list-thread-groups’, returns the list of top-level thread groups, which correspond to processes that GDB is debugging at the moment. By passing an identifier of a thread group to the ‘-list-thread-groups’ command, it is possible to obtain the members of specific thread group. d38162 5 a38166 5 wishes to debug, a concept of “available thread group” is introduced. Available thread group is an thread group that GDB is not debugging, but that can be attached to, using the ‘-target-attach’ command. The list of available top-level thread groups can be obtained using ‘-list-thread-groups --available’. In general, the content of a thread d38171 1 a38171 1 special type ‘process’, and some additional operations are permitted on d38191 2 a38192 2 ‘COMMAND ↦’ ‘CLI-COMMAND | MI-COMMAND’ d38194 2 a38195 2 ‘CLI-COMMAND ↦’ ‘[ TOKEN ] CLI-COMMAND NL’, where CLI-COMMAND is any existing GDB d38198 3 a38200 3 ‘MI-COMMAND ↦’ ‘[ TOKEN ] "-" OPERATION ( " " OPTION )* [ " --" ] ( " " PARAMETER )* NL’ d38202 1 a38202 1 ‘TOKEN ↦’ d38205 2 a38206 2 ‘OPTION ↦’ ‘"-" PARAMETER [ " " PARAMETER ]’ d38208 2 a38209 2 ‘PARAMETER ↦’ ‘NON-BLANK-SEQUENCE | C-STRING’ d38211 1 a38211 1 ‘OPERATION ↦’ d38214 1 a38214 1 ‘NON-BLANK-SEQUENCE ↦’ d38218 2 a38219 2 ‘C-STRING ↦’ ‘""" SEVEN-BIT-ISO-C-STRING-CONTENT """’ d38221 2 a38222 2 ‘NL ↦’ ‘CR | CR-LF’ d38226 1 a38226 1 • The CLI commands are still handled by the MI interpreter; their d38229 1 a38229 1 • The ‘TOKEN’, when present, is passed back when the command d38232 5 a38236 5 • Some MI commands accept optional arguments as part of the parameter list. Each option is identified by a leading ‘-’ (dash) and may be followed by an optional argument parameter. Options occur first in the parameter list and can be delimited from normal parameters using ‘--’ (this is useful when some parameters begin with a dash). d38240 1 a38240 1 • We want easy access to the existing CLI syntax (for debugging). d38242 1 a38242 1 • We want it to be easy to spot a MI operation. d38253 1 a38253 1 terminated by ‘(gdb)’. d38255 1 a38255 1 If an input command was prefixed with a ‘TOKEN’ then the d38259 2 a38260 2 ‘OUTPUT ↦’ ‘( OUT-OF-BAND-RECORD )* [ RESULT-RECORD ] "(gdb)" NL’ d38262 2 a38263 2 ‘RESULT-RECORD ↦’ ‘ [ TOKEN ] "^" RESULT-CLASS ( "," RESULT )* NL’ d38265 2 a38266 2 ‘OUT-OF-BAND-RECORD ↦’ ‘ASYNC-RECORD | STREAM-RECORD’ d38268 2 a38269 2 ‘ASYNC-RECORD ↦’ ‘EXEC-ASYNC-OUTPUT | STATUS-ASYNC-OUTPUT | NOTIFY-ASYNC-OUTPUT’ d38271 2 a38272 2 ‘EXEC-ASYNC-OUTPUT ↦’ ‘[ TOKEN ] "*" ASYNC-OUTPUT NL’ d38274 2 a38275 2 ‘STATUS-ASYNC-OUTPUT ↦’ ‘[ TOKEN ] "+" ASYNC-OUTPUT NL’ d38277 2 a38278 2 ‘NOTIFY-ASYNC-OUTPUT ↦’ ‘[ TOKEN ] "=" ASYNC-OUTPUT NL’ d38280 2 a38281 2 ‘ASYNC-OUTPUT ↦’ ‘ASYNC-CLASS ( "," RESULT )*’ d38283 2 a38284 2 ‘RESULT-CLASS ↦’ ‘"done" | "running" | "connected" | "error" | "exit"’ d38286 2 a38287 2 ‘ASYNC-CLASS ↦’ ‘"stopped" | OTHERS’ (where OTHERS will be added depending on the d38290 2 a38291 2 ‘RESULT ↦’ ‘ VARIABLE "=" VALUE’ d38293 2 a38294 2 ‘VARIABLE ↦’ ‘ STRING ’ d38296 2 a38297 2 ‘VALUE ↦’ ‘ CONST | TUPLE | LIST ’ d38299 2 a38300 2 ‘CONST ↦’ ‘C-STRING’ d38302 2 a38303 2 ‘TUPLE ↦’ ‘ "{}" | "{" RESULT ( "," RESULT )* "}" ’ d38305 3 a38307 3 ‘LIST ↦’ ‘ "[]" | "[" VALUE ( "," VALUE )* "]" | "[" RESULT ( "," RESULT )* "]" ’ d38309 2 a38310 2 ‘STREAM-RECORD ↦’ ‘CONSOLE-STREAM-OUTPUT | TARGET-STREAM-OUTPUT | LOG-STREAM-OUTPUT’ d38312 2 a38313 2 ‘CONSOLE-STREAM-OUTPUT ↦’ ‘"~" C-STRING NL’ d38315 2 a38316 2 ‘TARGET-STREAM-OUTPUT ↦’ ‘"@@" C-STRING NL’ d38318 2 a38319 2 ‘LOG-STREAM-OUTPUT ↦’ ‘"&" C-STRING NL’ d38321 2 a38322 2 ‘NL ↦’ ‘CR | CR-LF’ d38324 1 a38324 1 ‘TOKEN ↦’ d38329 1 a38329 1 • All output sequences end in a single line containing a period. d38331 1 a38331 1 • The ‘TOKEN’ is from the corresponding request. Note that for all d38338 1 a38338 1 • STATUS-ASYNC-OUTPUT contains on-going status information about the d38340 1 a38340 1 output is prefixed by ‘+’. d38342 1 a38342 1 • EXEC-ASYNC-OUTPUT contains asynchronous state change on the target d38344 1 a38344 1 ‘*’. d38346 1 a38346 1 • NOTIFY-ASYNC-OUTPUT contains supplementary information that the d38348 5 a38352 1 notify output is prefixed by ‘=’. d38354 2 a38355 3 • CONSOLE-STREAM-OUTPUT is output that should be displayed as is in the console. It is the textual response to a CLI command. All the console output is prefixed by ‘~’. d38357 3 a38359 2 • TARGET-STREAM-OUTPUT is the output produced by the target program. All the target output is prefixed by ‘@@’. d38361 1 a38361 3 • LOG-STREAM-OUTPUT is output text coming from GDB's internals, for instance messages that should be displayed as part of an error log. All the log output is prefixed by ‘&’. a38362 1 • New GDB/MI commands should only output LISTS containing VALUES. d38373 2 a38374 2 For the developers convenience CLI commands can be entered directly, but there may be some unexpected behaviour. For example, commands that d38376 2 a38377 2 command lists are not executed and some CLI commands, such as ‘if’, ‘when’ and ‘define’, prompt for further input with ‘>’, which is not d38381 1 a38381 1 recommended that front ends use the ‘-interpreter-exec’ command (*note d38391 1 a38391 1 program being debugged to the user is called a “front end”. d38395 2 a38396 2 the protocol changes and how to request previous version of the protocol when it does. d38399 3 a38401 3 for these the MI version will remain unchanged. The following is a list of changes that may occur within one level, so front ends should parse MI output in a way that can handle them: d38403 1 a38403 1 • New MI commands may be added. d38405 4 a38408 1 • New fields may be added to the output of any MI command. a38409 2 • The range of values for fields with specified values, e.g., ‘in_scope’ (*note -var-update::) may be extended. d38417 1 a38417 1 Since ‘--interpreter=mi’ always points to the latest MI version, it d38419 1 a38419 1 launching GDB (e.g. ‘--interpreter=mi2’) to make sure they get an d38428 4 a38431 6 --------------------------------------------------------------------------- 1 5.1 None 2 6.0 • The ‘-environment-pwd’, ‘-environment-directory’ and ‘-environment-path’ commands now returns values d38435 1 a38435 1 • ‘-var-list-children’'s ‘children’ result field is d38438 1 a38438 1 • ‘-var-update’'s ‘changelist’ result field is now a d38440 1 a38440 3 3 9.1 • The output of information about multi-location d38442 4 a38445 4 ‘-break-insert’ and ‘-break-info’ commands, as well as in the ‘=breakpoint-created’ and ‘=breakpoint-modified’ events. The multiple locations are now placed in a ‘locations’ field, d38447 1 a38447 3 4 13.1 • The syntax of the "script" field in breakpoint d38449 4 a38452 6 ‘-break-insert’ and ‘-break-info’ commands, as well as the ‘=breakpoint-created’ and ‘=breakpoint-modified’ events. The previous output was syntactically invalid. The new output is a list. d38458 1 a38458 1 ‘-fix-multi-location-breakpoint-output’ d38463 1 a38463 1 ‘-fix-breakpoint-script-output’ d38468 1 d38471 1 a38471 1 development on and . d38498 2 a38499 2 ‘"^done" [ "," RESULTS ]’ The synchronous operation was successful, ‘RESULTS’ are the return d38502 3 a38504 3 ‘"^running"’ This result record is equivalent to ‘^done’. Historically, it was output instead of ‘^done’ if the command has resumed the target. d38506 2 a38507 2 frontends should treat ‘^done’ and ‘^running’ identically and rely on the ‘*running’ output record to determine which threads are d38510 1 a38510 1 ‘"^connected"’ d38513 2 a38514 2 ‘"^error" "," "msg=" C-STRING [ "," "code=" C-STRING ]’ The operation failed. The ‘msg=C-STRING’ variable contains the d38517 1 a38517 1 If present, the ‘code=C-STRING’ variable provides an error code on d38521 1 a38521 1 ‘"undefined-command"’ d38524 1 a38524 1 ‘"^exit"’ d38527 1 d38536 1 a38536 1 funneled through the GDB/MI interface using “stream records”. d38538 1 a38538 1 Each stream record begins with a unique “prefix character” which d38541 2 a38542 2 ‘STRING-OUTPUT’. This is either raw text (with an implicit new line) or a quoted C string (which does not contain an implicit newline). d38544 4 a38547 4 ‘"~" STRING-OUTPUT’ The console output stream contains text that should be displayed in the CLI console window. It contains the textual responses to CLI commands. d38549 1 a38549 1 ‘"@@" STRING-OUTPUT’ d38555 1 a38555 1 ‘"&" STRING-OUTPUT’ d38565 1 a38565 1 “Async” records are used to notify the GDB/MI client of additional d38572 1 a38572 1 ‘*running,thread-id="THREAD"’ d38574 2 a38575 2 thread ID of the thread that is now running, and it can be ‘all’ if all threads are running. The frontend should assume that no d38584 1 a38584 1 ‘*stopped,reason="REASON",thread-id="ID",stopped-threads="STOPPED",core="CORE"’ d38588 1 a38588 1 ‘breakpoint-hit’ d38590 2 a38591 1 ‘watchpoint-trigger’ d38593 2 a38594 1 ‘read-watchpoint-trigger’ d38596 2 a38597 1 ‘access-watchpoint-trigger’ d38599 2 a38600 1 ‘function-finished’ d38602 2 a38603 1 ‘location-reached’ d38605 2 a38606 1 ‘watchpoint-scope’ d38608 2 a38609 1 ‘end-stepping-range’ d38613 2 a38614 1 ‘exited-signalled’ d38616 2 a38617 1 ‘exited’ d38619 2 a38620 1 ‘exited-normally’ d38622 2 a38623 1 ‘signal-received’ d38625 2 a38626 1 ‘solib-event’ d38628 2 a38629 2 unloaded. This can happen when ‘stop-on-solib-events’ (*note Files::) is set or when a ‘catch load’ or ‘catch unload’ d38631 3 a38633 2 ‘fork’ The inferior has forked. This is reported when ‘catch fork’ d38635 6 a38640 4 ‘vfork’ The inferior has vforked. This is reported in when ‘catch vfork’ (*note Set Catchpoints::) has been used. ‘syscall-entry’ d38642 3 a38644 2 ‘catch syscall’ (*note Set Catchpoints::) has been used. ‘syscall-return’ d38646 7 a38652 5 when ‘catch syscall’ (*note Set Catchpoints::) has been used. ‘exec’ The inferior called ‘exec’. This is reported when ‘catch exec’ (*note Set Catchpoints::) has been used. ‘no-history’ d38661 2 a38662 2 STOPPED field will have the value of ‘"all"’. Otherwise, the value of the STOPPED field will be a list of thread identifiers. d38669 2 a38670 2 ‘=thread-group-added,id="ID"’ ‘=thread-group-removed,id="ID"’ d38673 3 a38675 3 added, it generally might not be associated with a running process. When a thread group is removed, its id becomes invalid and cannot be used in any way. d38677 1 a38677 1 ‘=thread-group-started,id="ID",pid="PID"’ d38680 2 a38681 2 attached to a program. The ID field contains the GDB identifier of the thread group. The PID field contains process identifier, d38684 1 a38684 1 ‘=thread-group-exited,id="ID"[,exit-code="CODE"]’ d38691 2 a38692 2 ‘=thread-created,id="ID",group-id="GID"’ ‘=thread-exited,id="ID",group-id="GID"’ d38697 1 a38697 1 ‘=thread-selected,id="ID"[,frame="FRAME"]’ d38699 2 a38700 2 notification is not emitted as result of the ‘-thread-select’ or ‘-stack-select-frame’ commands, but is emitted whenever an MI d38703 1 a38703 1 indirectly (via user-defined command), the CLI ‘thread’ or ‘frame’ d38705 1 a38705 1 frame from another user interface (see *note Interpreters::) will d38709 1 a38709 1 stopped. See *note GDB/MI Frame Information:: for the format of d38716 1 a38716 1 ‘=library-loaded,...’ d38719 12 a38730 11 SYMBOLS-LOADED and RANGES. The ID field is an opaque identifier of the library. For remote debugging case, TARGET-NAME and HOST-NAME fields give the name of the library file on the target, and on the host respectively. For native debugging, both those fields have the same value. The SYMBOLS-LOADED field is emitted only for backward compatibility and should not be relied on to convey any useful information. The THREAD-GROUP field, if present, specifies the id of the thread group in whose context the library was loaded. If the field is absent, it means the library was loaded in the context of all present thread groups. The RANGES field specifies the ranges of addresses belonging to this library. d38732 1 a38732 1 ‘=library-unloaded,...’ d38735 1 a38735 1 same meaning as for the ‘=library-loaded’ notification. The d38741 2 a38742 2 ‘=traceframe-changed,num=TFNUM,tracepoint=TPNUM’ ‘=traceframe-changed,end’ d38747 1 a38747 1 ‘=tsv-created,name=NAME,initial=INITIAL’ d38751 2 a38752 2 ‘=tsv-deleted,name=NAME’ ‘=tsv-deleted’ d38756 1 a38756 1 ‘=tsv-modified,name=NAME,initial=INITIAL[,current=CURRENT]’ d38758 1 a38758 1 initial value INITIAL. The current value CURRENT of trace state d38762 3 a38764 3 ‘=breakpoint-created,bkpt={...}’ ‘=breakpoint-modified,bkpt={...}’ ‘=breakpoint-deleted,id=NUMBER’ d38776 2 a38777 2 ‘=record-started,thread-group="ID",method="METHOD"[,format="FORMAT"]’ ‘=record-stopped,thread-group="ID"’ d38782 10 a38791 10 The METHOD field indicates the method used to record execution. If the method in use supports multiple recording formats, FORMAT will be present and contain the currently used format. *Note Process Record and Replay::, for existing method and format values. ‘=cmd-param-changed,param=PARAM,value=VALUE’ Reports that a parameter of the command ‘set PARAM’ is changed to VALUE. In the multi-word ‘set’ command, the PARAM is the whole parameter list to ‘set’ command. For example, In command ‘set check type on’, PARAM is ‘check type’ and VALUE is ‘on’. d38793 1 a38793 1 ‘=memory-changed,thread-group=ID,addr=ADDR,len=LEN[,type="code"]’ d38796 3 a38798 2 corresponding to the affected inferior. The optional ‘type="code"’ part is reported if the memory written to holds executable code. d38809 1 a38809 1 ‘number’ d38812 1 a38812 1 ‘type’ d38814 1 a38814 1 ‘breakpoint’, but many values are possible. d38816 2 a38817 2 ‘catch-type’ If the type of the breakpoint is ‘catchpoint’, then this indicates d38820 3 a38822 3 ‘disp’ This is the breakpoint disposition--either ‘del’, meaning that the breakpoint will be deleted at the next stop, or ‘keep’, meaning d38825 1 a38825 1 ‘enabled’ d38827 2 a38828 2 value is ‘y’, or disabled, in which case the value is ‘n’. Note that this is not the same as the field ‘enable’. d38830 1 a38830 1 ‘addr’ d38832 2 a38833 2 giving the address; or the string ‘’, for a pending breakpoint; or the string ‘’, for a breakpoint with d38838 1 a38838 1 ‘addr_flags’ d38840 1 a38840 1 flags are architecture-dependent; see *note Architectures:: for d38843 1 a38843 1 ‘func’ d38847 1 a38847 1 ‘filename’ d38851 7 a38857 7 ‘fullname’ The full file name of the source file which contains this function, if known. If not known, this field is not present. ‘line’ The line number at which this breakpoint appears, if known. If not known, this field is not present. d38859 1 a38859 1 ‘at’ d38864 1 a38864 1 ‘pending’ d38868 3 a38870 3 ‘evaluated-by’ Where this breakpoint's condition is evaluated, either ‘host’ or ‘target’. d38872 1 a38872 1 ‘thread’ d38876 1 a38876 1 ‘inferior’ d38880 1 a38880 1 ‘task’ d38884 1 a38884 1 ‘cond’ d38887 1 a38887 1 ‘ignore’ d38890 1 a38890 1 ‘enable’ d38893 1 a38893 1 ‘traceframe-usage’ d38896 1 a38896 1 ‘static-tracepoint-marker-string-id’ d38899 1 a38899 1 ‘mask’ d38902 1 a38902 1 ‘pass’ d38905 1 a38905 1 ‘original-location’ d38909 1 a38909 1 ‘times’ d38912 3 a38914 3 ‘installed’ This field is only given for tracepoints. This is either ‘y’, meaning that the tracepoint is installed, or ‘n’, meaning that it d38917 1 a38917 1 ‘what’ d38920 4 a38923 4 ‘locations’ This field is present if the breakpoint has multiple locations. It is also exceptionally present if the breakpoint is enabled and has a single, disabled location. d38928 1 d38932 2 a38933 2 ‘number’ The location number as a dotted pair, like ‘1.2’. The first digit d38937 1 a38937 1 ‘enabled’ d38939 1 a38939 1 ‘y’ d38941 2 a38942 1 ‘n’ d38944 2 a38945 1 ‘N’ d38949 1 a38949 1 ‘addr’ d38952 1 a38952 1 ‘addr_flags’ d38954 1 a38954 1 flags are architecture-dependent; see *note Architectures:: for d38957 1 a38957 1 ‘func’ d38961 1 a38961 1 ‘file’ d38965 3 a38967 3 ‘fullname’ The full file name of the source file which contains this location, if known. If not known, this field is not present. d38969 1 a38969 1 ‘line’ d38973 1 a38973 1 ‘thread-groups’ d38976 3 a38978 2 For example, here is what the output of ‘-break-insert’ (*note GDB/MI Breakpoint Commands::) might be: d38996 1 a38996 1 ‘level’ d39000 1 a39000 1 ‘func’ d39004 1 a39004 1 ‘addr’ d39007 1 a39007 1 ‘addr_flags’ d39009 1 a39009 1 flags are architecture-dependent; see *note Architectures:: for d39012 1 a39012 1 ‘file’ d39016 1 a39016 1 ‘line’ d39020 1 a39020 1 ‘from’ d39025 1 d39036 1 a39036 1 ‘id’ d39039 1 a39039 1 ‘target-id’ d39042 3 a39044 3 ‘details’ Additional information about the thread provided by the target. It is supposed to be human-readable and not interpreted by the d39047 1 a39047 1 ‘name’ d39049 1 a39049 1 ‘thread name’ command, then this name is given. Otherwise, if GDB d39054 2 a39055 2 ‘state’ The execution state of the thread, either ‘stopped’ or ‘running’, d39058 1 a39058 1 ‘frame’ d39061 1 a39061 1 *note GDB/MI Frame Information::. d39063 1 a39063 1 ‘core’ d39073 1 a39073 1 Whenever a ‘*stopped’ record is emitted because the program stopped d39076 3 a39078 3 ‘exception-name’ field. Also, for exceptions that were raised with an exception message, GDB provides that message via the ‘exception-message’ field. d39087 2 a39088 2 the GDB/MI interface. In these examples, ‘->’ means that the following line is passed to GDB/MI as input, while ‘<-’ means the output received d39110 2 a39111 2 Program execution generates asynchronous records and MI gives the reason that execution stopped. d39131 1 a39131 1 Quitting GDB just prints the result class ‘^exit’. d39137 1 a39137 1 Please note that ‘^exit’ is printed immediately, but it might take d39205 1 a39205 1 The ‘-break-after’ Command d39215 1 a39215 1 ‘-break-list’ command, see the description of the ‘-break-list’ command d39221 1 a39221 1 The corresponding GDB command is ‘ignore’. d39250 1 a39250 1 The ‘-break-commands’ Command d39268 1 a39268 1 The corresponding GDB command is ‘commands’. d39284 1 a39284 1 The ‘-break-condition’ Command d39292 6 a39297 6 Breakpoint NUMBER will stop the program only if the condition in EXPR is true. The condition becomes part of the ‘-break-list’ output (see the description of the ‘-break-list’ command below). If the ‘--force’ flag is passed, the condition is forcibly defined even when it is invalid for all locations of breakpoint NUMBER. If the EXPR argument is omitted, breakpoint NUMBER becomes unconditional. d39302 1 a39302 1 The corresponding GDB command is ‘condition’. d39324 1 a39324 1 The ‘-break-delete’ Command d39338 1 a39338 1 The corresponding GDB command is ‘delete’. d39358 1 a39358 1 The ‘-break-disable’ Command d39366 2 a39367 2 Disable the named BREAKPOINT(s). The field ‘enabled’ in the break list is now set to ‘n’ for the named BREAKPOINT(s). d39372 1 a39372 1 The corresponding GDB command is ‘disable’. d39394 1 a39394 1 The ‘-break-enable’ Command d39407 1 a39407 1 The corresponding GDB command is ‘enable’. d39429 1 a39429 1 The ‘-break-info’ Command d39446 1 a39446 1 The corresponding GDB command is ‘info break BREAKPOINT’. d39453 1 a39453 1 The ‘-break-insert’ Command d39473 1 a39473 1 ‘--source FILENAME’ d39475 1 a39475 1 the use of either ‘--function’ or ‘--line’. d39477 1 a39477 1 ‘--function FUNCTION’ d39480 1 a39480 1 ‘--label LABEL’ d39483 1 a39483 1 ‘--line LINEOFFSET’ d39492 1 a39492 1 ‘-t’ d39494 2 a39495 1 ‘-h’ d39497 2 a39498 1 ‘-f’ d39503 2 a39504 1 ‘-d’ d39506 2 a39507 1 ‘-a’ d39509 3 a39511 2 used together with ‘-h’, a fast tracepoint is created. ‘-c CONDITION’ d39513 2 a39514 1 ‘--force-condition’ d39517 2 a39518 1 ‘-i IGNORE-COUNT’ d39520 2 a39521 1 ‘-p THREAD-ID’ d39524 4 a39527 3 breakpoint is requested. Breakpoints created with a THREAD-ID will automatically be deleted when the corresponding thread exits. ‘-g THREAD-GROUP-ID’ d39530 2 a39531 1 ‘--qualified’ d39546 2 a39547 2 The corresponding GDB commands are ‘break’, ‘tbreak’, ‘hbreak’, and ‘thbreak’. d39581 1 a39581 1 The ‘-dprintf-insert’ Command d39596 2 a39597 2 If supplied, LOCSPEC and ‘--qualified’ may be specified the same way as for the ‘-break-insert’ command. *Note -break-insert::. d39601 1 a39601 1 ‘-t’ d39603 2 a39604 1 ‘-f’ d39609 2 a39610 1 ‘-d’ d39612 2 a39613 1 ‘-c CONDITION’ d39615 2 a39616 1 ‘--force-condition’ d39619 2 a39620 1 ‘-i IGNORE-COUNT’ d39622 3 a39624 2 Conditions.) to IGNORE-COUNT. ‘-p THREAD-ID’ d39637 1 a39637 1 The corresponding GDB command is ‘dprintf’. d39658 1 a39658 1 The ‘-break-list’ Command d39669 1 a39669 1 ‘Number’ d39671 12 a39682 8 ‘Type’ type of the breakpoint: ‘breakpoint’ or ‘watchpoint’ ‘Disposition’ should the breakpoint be deleted or disabled when it is hit: ‘keep’ or ‘nokeep’ ‘Enabled’ is the breakpoint enabled or no: ‘y’ or ‘n’ ‘Address’ d39684 2 a39685 1 ‘What’ d39688 2 a39689 1 ‘Thread-groups’ d39691 2 a39692 1 ‘Times’ d39696 1 a39696 1 catchpoints, the ‘BreakpointTable’ ‘body’ field is an empty list. d39701 1 a39701 1 The corresponding GDB command is ‘info break’. d39737 1 a39737 1 The ‘-break-passcount’ Command d39747 1 a39747 1 error is emitted. This corresponds to CLI command ‘passcount’. d39749 1 a39749 1 The ‘-break-watch’ Command d39757 8 a39764 8 Create a watchpoint. With the ‘-a’ option it will create an “access” watchpoint, i.e., a watchpoint that triggers either on a read from or on a write to the memory location. With the ‘-r’ option, the watchpoint created is a “read” watchpoint, i.e., it will trigger only when the memory location is accessed for reading. Without either of the options, the watchpoint created is a regular watchpoint, i.e., it will trigger when the memory location is accessed for writing. *Note Setting Watchpoints: Set Watchpoints. d39766 1 a39766 1 Note that ‘-break-list’ will report a single list of watchpoints and d39772 1 a39772 1 The corresponding GDB commands are ‘watch’, ‘awatch’, and ‘rwatch’. d39777 1 a39777 1 Setting a watchpoint on a variable in the ‘main’ function: d39793 2 a39794 2 stop the program execution twice: first for the variable changing value, then for the watchpoint going out of scope. d39915 1 a39915 1 The ‘-catch-load’ Command d39923 1 a39923 1 Add a catchpoint for library load events. If the ‘-t’ option is d39925 2 a39926 2 Breaks.). If the ‘-d’ option is used, the catchpoint is created in a disabled state. The ‘regexp’ argument is a regular expression used to d39932 1 a39932 1 The corresponding GDB command is ‘catch load’. d39942 1 a39942 1 The ‘-catch-unload’ Command d39950 1 a39950 1 Add a catchpoint for library unload events. If the ‘-t’ option is d39952 2 a39953 2 Breaks.). If the ‘-d’ option is used, the catchpoint is created in a disabled state. The ‘regexp’ argument is a regular expression used to d39959 1 a39959 1 The corresponding GDB command is ‘catch unload’. d39978 1 a39978 1 The ‘-catch-assert’ Command d39990 1 a39990 1 ‘-c CONDITION’ d39992 2 a39993 1 ‘-d’ d39995 2 a39996 1 ‘-t’ d40002 1 a40002 1 The corresponding GDB command is ‘catch assert’. d40014 1 a40014 1 The ‘-catch-exception’ Command d40030 1 a40030 1 ‘-c CONDITION’ d40032 2 a40033 1 ‘-d’ d40035 2 a40036 1 ‘-e EXCEPTION-NAME’ d40038 3 a40040 2 used combined with ‘-u’. ‘-t’ d40042 2 a40043 1 ‘-u’ d40045 1 a40045 1 cannot be used combined with ‘-e’. d40050 2 a40051 2 The corresponding GDB commands are ‘catch exception’ and ‘catch exception unhandled’. d40063 1 a40063 1 The ‘-catch-handlers’ Command d40079 1 a40079 1 ‘-c CONDITION’ d40081 2 a40082 1 ‘-d’ d40084 2 a40085 1 ‘-e EXCEPTION-NAME’ d40087 2 a40088 1 ‘-t’ d40094 1 a40094 1 The corresponding GDB command is ‘catch handlers’. d40116 1 a40116 1 The ‘-catch-throw’ Command d40128 1 a40128 1 If ‘-t’ is given, then the catchpoint is enabled only for one stop, d40135 1 a40135 1 The corresponding GDB commands are ‘catch throw’ and ‘tcatch throw’ d40159 1 a40159 1 The ‘-catch-rethrow’ Command d40171 1 a40171 1 If ‘-t’ is given, then the catchpoint is enabled only for one stop, d40177 1 a40177 1 The corresponding GDB commands are ‘catch rethrow’ and ‘tcatch rethrow’ d40201 1 a40201 1 The ‘-catch-catch’ Command d40213 1 a40213 1 If ‘-t’ is given, then the catchpoint is enabled only for one stop, d40219 1 a40219 1 The corresponding GDB commands are ‘catch catch’ and ‘tcatch catch’ d40246 2 a40247 2 27.10 GDB/MI Program Context ============================ d40249 1 a40249 1 The ‘-exec-arguments’ Command d40258 1 a40258 1 ‘-exec-run’. d40263 1 a40263 1 The corresponding GDB command is ‘set args’. d40273 1 a40273 1 The ‘-environment-cd’ Command d40286 1 a40286 1 The corresponding GDB command is ‘cd’. d40296 1 a40296 1 The ‘-environment-directory’ Command d40305 1 a40305 1 If the ‘-r’ option is used, the search path is reset to the default d40307 1 a40307 1 ‘-r’ option, the search path is first reset and then addition occurs as d40315 2 a40316 2 not be used in any directory name. If no directories are specified, the current search path is displayed. d40321 1 a40321 1 The corresponding GDB command is ‘dir’. d40340 1 a40340 1 The ‘-environment-path’ Command d40349 1 a40349 1 If the ‘-r’ option is used, the search path is reset to the original d40351 1 a40351 1 supplied in addition to the ‘-r’ option, the search path is first reset d40365 1 a40365 1 The corresponding GDB command is ‘path’. d40381 1 a40381 1 The ‘-environment-pwd’ Command d40394 1 a40394 1 The corresponding GDB command is ‘pwd’. d40410 1 a40410 1 The ‘-thread-info’ Command d40420 1 a40420 1 global thread ID. When printing information about all threads, also d40426 1 a40426 1 The ‘info thread’ command prints the same information about all threads. d40433 1 a40433 1 ‘threads’ d40435 1 a40435 1 described in *note GDB/MI Thread Information::. d40437 1 a40437 1 ‘current-thread-id’ d40443 1 d40460 1 a40460 1 The ‘-thread-list-ids’ Command d40468 2 a40469 2 Produces a list of the currently known global GDB thread ids. At the end of the list it also prints the total number of such threads. d40471 1 a40471 1 This command is retained for historical reasons, the ‘-thread-info’ d40477 1 a40477 1 Part of ‘info threads’ supplies the same information. d40488 1 a40488 1 The ‘-thread-select’ Command d40501 1 a40501 1 ‘--thread’ option to each command. d40506 1 a40506 1 The corresponding GDB command is ‘thread’. d40536 1 a40536 1 The ‘-ada-task-info’ Command d40550 2 a40551 2 The ‘info tasks’ command prints the same information about all Ada tasks (*note Ada Tasks::). d40559 1 a40559 1 ‘current’ d40561 1 a40561 1 ‘*’. d40563 1 a40563 1 ‘id’ d40566 1 a40566 1 ‘task-id’ d40569 1 a40569 1 ‘thread-id’ d40577 1 a40577 1 ‘parent-id’ d40581 1 a40581 1 ‘priority’ d40584 1 a40584 1 ‘state’ d40586 1 a40586 1 possible states, see *note Ada Tasks::. d40588 1 a40588 1 ‘name’ d40591 1 d40616 1 a40616 1 record ‘*stopped’. Currently GDB only really executes asynchronously d40619 1 a40619 1 The ‘-exec-continue’ Command d40627 2 a40628 2 Resumes the execution of the inferior program, which will continue to execute until it reaches a debugger stop event. If the ‘--reverse’ d40631 13 a40643 10 • breakpoints, watchpoints, tracepoints, or catchpoints • signals or exceptions • the end of the process (or its beginning under ‘--reverse’) • the end or beginning of a replay log if one is being used. In all-stop mode (*note All-Stop Mode::), may resume only one thread, or all threads, depending on the value of the ‘scheduler-locking’ variable. If ‘--all’ is specified, all threads (in all inferiors) will be resumed. The ‘--all’ option is ignored in all-stop mode. If the ‘--thread-group’ options is specified, then all threads in that thread group are resumed. d40648 1 a40648 1 The corresponding GDB corresponding is ‘continue’. d40662 3 a40664 3 For a ‘breakpoint-hit’ stopped reason, when the breakpoint encountered has multiple locations, the field ‘bkptno’ is followed by the field ‘locno’. d40675 1 a40675 1 The ‘-exec-finish’ Command d40685 1 a40685 1 the ‘--reverse’ option is specified, resumes the reverse execution of d40691 1 a40691 1 The corresponding GDB command is ‘finish’. d40696 1 a40696 1 Function returning ‘void’. d40706 1 a40706 1 Function returning other than ‘void’. The name of the internal GDB d40719 1 a40719 1 The ‘-exec-interrupt’ Command d40730 1 a40730 1 only appears in the ‘^done’ output. If the user is trying to interrupt d40735 2 a40736 2 ‘^done’ response will be printed, and the target stop will be reported after that using the ‘*stopped’ notification. d40739 3 a40741 3 All threads (in all inferiors) will be interrupted if the ‘--all’ option is specified. If the ‘--thread-group’ option is specified, all threads in that group will be interrupted. d40746 1 a40746 1 The corresponding GDB command is ‘interrupt’. d40769 1 a40769 1 The ‘-exec-jump’ Command d40778 2 a40779 2 LOCSPEC resolves. *Note Location Specifications::, for a description of the different forms of LOCSPEC. d40784 1 a40784 1 The corresponding GDB command is ‘jump’. d40793 1 a40793 1 The ‘-exec-next’ Command d40804 1 a40804 1 If the ‘--reverse’ option is specified, resumes reverse execution of d40813 1 a40813 1 The corresponding GDB command is ‘next’. d40824 1 a40824 1 The ‘-exec-next-instruction’ Command d40837 1 a40837 1 If the ‘--reverse’ option is specified, resumes reverse execution of d40846 1 a40846 1 The corresponding GDB command is ‘nexti’. d40860 1 a40860 1 The ‘-exec-return’ Command d40874 1 a40874 1 The corresponding GDB command is ‘return’. d40905 1 a40905 1 The ‘-exec-run’ Command d40915 2 a40916 2 In the latter case the output will include an exit code, if the program has exited exceptionally. d40918 2 a40919 2 When neither the ‘--all’ nor the ‘--thread-group’ option is specified, the current inferior is started. If the ‘--thread-group’ d40921 2 a40922 2 ‘process’, and that thread group will be started. If the ‘--all’ option is specified, then all inferiors will be started. d40924 1 a40924 1 Using the ‘--start’ option instructs the debugger to stop the d40926 1 a40926 1 same behavior as the ‘start’ command (*note Starting::). d40931 1 a40931 1 The corresponding GDB command is ‘run’. d40968 2 a40969 2 Another way the program can terminate is if it receives a signal such as ‘SIGINT’. In this case, GDB/MI displays this: d40975 1 a40975 1 The ‘-exec-step’ Command d40984 3 a40986 3 beginning of the next source line is reached, if the next source line is not a function call. If it is, stop at the first instruction of the called function. If the ‘--reverse’ option is specified, resumes d40993 1 a40993 1 The corresponding GDB command is ‘step’. d41017 1 a41017 1 The ‘-exec-step-instruction’ Command d41026 1 a41026 1 ‘--reverse’ option is specified, resumes reverse execution of the d41035 1 a41035 1 The corresponding GDB command is ‘stepi’. d41058 1 a41058 1 The ‘-exec-until’ Command d41069 1 a41069 1 stopping in this case will be ‘location-reached’. d41074 1 a41074 1 The corresponding GDB command is ‘until’. d41095 1 a41095 1 The ‘-enable-frame-filters’ Command d41101 3 a41103 3 commands relating to stack traces. As there is no way to implement this in a fully backward-compatible way, a front end must request that this functionality be enabled. d41110 1 a41110 1 The ‘-stack-info-frame’ Command d41123 1 a41123 1 The corresponding GDB command is ‘info frame’ or ‘frame’ (without d41137 1 a41137 1 The ‘-stack-info-depth’ Command d41175 1 a41175 1 The ‘-stack-list-arguments’ Command d41187 11 a41197 11 equal, show the single frame at the corresponding level. It is an error if LOW-FRAME is larger than the actual number of frames. On the other hand, HIGH-FRAME may be larger than the actual number of frames, in which case only existing frames will be returned. If PRINT-VALUES is 0 or ‘--no-values’, print only the names of the variables; if it is 1 or ‘--all-values’, print also their values; and if it is 2 or ‘--simple-values’, print the name, type and value for simple data types, and the name and type for arrays, structures and unions. If the option ‘--no-frame-filters’ is supplied, then Python frame filters will not be executed. d41199 1 a41199 1 If the ‘--skip-unavailable’ option is specified, arguments that are d41204 1 a41204 1 deprecated in favor of the ‘-stack-list-variables’ command. d41209 1 a41209 1 GDB does not have an equivalent command. ‘gdbtk’ has a ‘gdb_get_args’ d41211 1 a41211 1 ‘-stack-list-arguments’. d41274 1 a41274 1 The ‘-stack-list-frames’ Command d41285 1 a41285 1 ‘LEVEL’ d41288 5 a41292 3 ‘ADDR’ The ‘$pc’ value for that frame. ‘FUNC’ d41294 2 a41295 1 ‘FILE’ d41297 2 a41298 1 ‘FULLNAME’ d41300 5 a41304 3 ‘LINE’ Line number corresponding to the ‘$pc’. ‘FROM’ d41307 2 a41308 1 ‘ARCH’ d41318 1 a41318 1 option ‘--no-frame-filters’ is supplied, then Python frame filters will d41324 1 a41324 1 The corresponding GDB commands are ‘backtrace’ and ‘where’. d41398 1 a41398 1 The ‘-stack-list-locals’ Command d41407 9 a41415 9 PRINT-VALUES is 0 or ‘--no-values’, print only the names of the variables; if it is 1 or ‘--all-values’, print also their values; and if it is 2 or ‘--simple-values’, print the name, type and value for simple data types, and the name and type for arrays, structures and unions. In this last case, a frontend can immediately display the value of simple data types and create variable objects for other data types when the user wishes to explore their values in more detail. If the option ‘--no-frame-filters’ is supplied, then Python frame filters will not be executed. d41417 3 a41419 3 If the ‘--skip-unavailable’ option is specified, local variables that are not available are not listed. Partially available local variables are still displayed, however. d41421 1 a41421 1 This command is deprecated in favor of the ‘-stack-list-variables’ d41427 1 a41427 1 ‘info locals’ in GDB, ‘gdb_get_locals’ in ‘gdbtk’. d41444 1 a41444 1 The ‘-stack-list-variables’ Command d41453 3 a41455 3 selected frame. If PRINT-VALUES is 0 or ‘--no-values’, print only the names of the variables; if it is 1 or ‘--all-values’, print also their values; and if it is 2 or ‘--simple-values’, print the name, type and d41457 1 a41457 1 structures and unions. If the option ‘--no-frame-filters’ is supplied, d41460 1 a41460 1 If the ‘--skip-unavailable’ option is specified, local variables and d41472 1 a41472 1 The ‘-stack-select-frame’ Command d41483 1 a41483 1 This command in deprecated in favor of passing the ‘--frame’ option d41489 2 a41490 2 The corresponding GDB commands are ‘frame’, ‘up’, ‘down’, ‘select-frame’, ‘up-silent’, and ‘down-silent’. d41512 2 a41513 2 simple and efficient presentation in the frontend. A variable object is identified by string name. When a variable object is created, the d41547 2 a41548 2 reference, and never update it. For another example, fetching memory is relatively slow for embedded targets, so a frontend might want to d41553 1 a41553 1 Variable objects can be either “fixed” or “floating”. For the fixed d41556 2 a41557 2 meaning of expression never changes. For a floating variable object the values of variables whose names appear in the expressions are d41569 5 a41573 5 If a fixed variable object for the ‘state’ variable is created in this function, and we enter the recursive call, the variable object will report the value of ‘state’ in the top-level ‘do_work’ invocation. On the other hand, a floating variable object will report the value of ‘state’ in the current frame. d41586 3 a41588 4 ‘-enable-pretty-printing’ enable Python-based pretty-printing ‘-var-create’ create a variable object ‘-var-delete’ delete the variable object and/or its d41590 8 a41597 8 ‘-var-set-format’ set the display format of this variable ‘-var-show-format’ show the display format of this variable ‘-var-info-num-children’ tells how many children this object has ‘-var-list-children’ return a list of the object's children ‘-var-info-type’ show the type of this variable object ‘-var-info-expression’ print parent-relative expression that this variable object represents ‘-var-info-path-expression’ print full expression that this variable d41599 1 a41599 1 ‘-var-show-attributes’ is this variable editable? does it exist d41601 5 a41605 6 ‘-var-evaluate-expression’ get the value of this variable ‘-var-assign’ set the value of this variable ‘-var-update’ update the variable and its children ‘-var-set-frozen’ set frozenness attribute ‘-var-set-update-range’ set range of children to display on update d41613 1 a41613 1 The ‘-enable-pretty-printing’ Command d41628 1 a41628 1 The ‘-var-create’ Command d41637 3 a41639 3 This operation creates a variable object, which allows the monitoring of a variable, the result of an expression, a memory cell or a CPU register. d41642 1 a41642 1 referenced. It must be unique. If ‘-’ is specified, the varobj system d41648 2 a41649 2 specified by FRAME-ADDR. A ‘*’ indicates that the current frame should be used. A ‘@@’ indicates that a floating variable object must be d41653 1 a41653 1 not begin with a ‘*’), or one of the following: d41655 1 a41655 1 • ‘*ADDR’, where ADDR is the address of a memory cell d41657 1 a41657 1 • ‘*ADDR-ADDR’ -- a memory address range (TBD) d41659 1 a41659 1 • ‘$REGNAME’ -- a CPU register name d41661 6 a41666 6 A varobj's contents may be provided by a Python-based pretty-printer. In this case the varobj is known as a “dynamic varobj”. Dynamic varobjs have slightly different semantics in some cases. If the ‘-enable-pretty-printing’ command is not sent, then GDB will never create a dynamic varobj. This ensures backward compatibility for existing clients. d41674 1 a41674 1 ‘name’ d41677 1 a41677 1 ‘numchild’ d41680 1 a41680 1 examine the ‘has_more’ attribute. d41682 1 a41682 1 ‘value’ d41684 1 a41684 1 aggregate (e.g., a ‘struct’), this value will not be interesting. d41686 1 a41686 1 pretty-printer object's ‘to_string’ method. d41688 1 a41688 1 ‘type’ d41690 4 a41693 3 would be printed by the GDB CLI. If ‘print object’ (*note set print object: Print Settings.) is set to ‘on’, the _actual_ (derived) type of the object is shown rather than the _declared_ one. d41695 1 a41695 1 ‘thread-id’ d41699 1 a41699 1 ‘has_more’ d41703 4 a41706 4 ‘dynamic’ This attribute will be present and have the value ‘1’ if the varobj is a dynamic varobj. If the varobj is not a dynamic varobj, then this attribute will not be present. d41708 1 a41708 1 ‘displayhint’ d41711 1 a41711 1 ‘display_hint’ method. *Note Pretty Printing API::. d41718 1 a41718 1 The ‘-var-delete’ Command d41727 1 a41727 1 With the ‘-c’ option, just deletes the children. d41731 1 a41731 1 The ‘-var-set-format’ Command d41744 1 a41744 1 FORMAT-SPEC ↦ d41748 1 a41748 1 on the variable type (like decimal for an ‘int’, hex for pointers, d41759 1 a41759 1 The ‘-var-show-format’ Command d41769 1 a41769 1 FORMAT ↦ d41772 1 a41772 1 The ‘-var-info-num-children’ Command d41788 1 a41788 1 The ‘-var-list-children’ Command d41798 1 a41798 1 single argument or if PRINT-VALUES has a value of 0 or ‘--no-values’, d41800 2 a41801 2 ‘--all-values’, also print their values; and if it is 2 or ‘--simple-values’ print the name and value for simple data types and d41806 2 a41807 2 will be reported. Otherwise, children starting at FROM (zero-based) and up to and excluding TO will be reported. d41810 2 a41811 2 to ‘-var-list-children’, but not future calls to ‘-var-update’. For this, you must instead use ‘-var-set-update-range’. The intent of this d41814 2 a41815 2 more children with ‘-var-list-children’, and then the front end could call ‘-var-set-update-range’ with a different range to ensure that d41834 1 a41834 1 ‘public’, ‘private’, or ‘protected’. In this case the type and d41842 2 a41843 2 Number of children this child has. For a dynamic varobj, this will be 0. d41846 3 a41848 3 The type of the child. If ‘print object’ (*note set print object: Print Settings.) is set to ‘on’, the _actual_ (derived) type of the object is shown rather than the _declared_ one. d41864 1 a41864 1 ‘display_hint’ method. *Note Pretty Printing API::. d41867 4 a41870 3 This attribute will be present and have the value ‘1’ if the varobj is a dynamic varobj. If the varobj is not a dynamic varobj, then this attribute will not be present. d41874 1 a41874 1 ‘displayhint’ d41877 1 a41877 1 ‘display_hint’ method. *Note Pretty Printing API::. d41879 1 a41879 1 ‘has_more’ d41895 1 a41895 1 The ‘-var-info-type’ Command d41908 1 a41908 1 The ‘-var-info-expression’ Command d41916 3 a41918 3 Returns a string that is suitable for presenting this variable object in user interface. The string is generally not valid expression in the current language, and cannot be evaluated. d41920 2 a41921 2 For example, if ‘a’ is an array, and variable object ‘A’ was created for ‘a’, then we'll get this output: d41926 2 a41927 2 Here, the value of ‘lang’ is the language name, which can be found in *note Supported Languages::. d41929 2 a41930 2 Note that the output of the ‘-var-list-children’ command also includes those expressions, so the ‘-var-info-expression’ command is of d41933 1 a41933 1 The ‘-var-info-path-expression’ Command d41943 2 a41944 2 with the ‘-var-info-expression’ command, which result can be used only for UI presentation. Typical use of the ‘-var-info-path-expression’ d41950 4 a41953 4 For example, suppose ‘C’ is a C++ class, derived from class ‘Base’, and that the ‘Base’ class has a member called ‘m_size’. Assume a variable ‘c’ is has the type of ‘C’ and a variable object ‘C’ was created for variable ‘c’. Then, we'll get this output: d41957 1 a41957 1 The ‘-var-show-attributes’ Command d41969 1 a41969 1 where ATTR is ‘{ { editable | noneditable } | TBD }’. d41971 1 a41971 1 The ‘-var-evaluate-expression’ Command d41981 3 a41983 3 string can be specified with the ‘-f’ option. The possible values of this option are the same as for ‘-var-set-format’ (*note -var-set-format::). If the ‘-f’ option is not specified, the current d41985 1 a41985 1 using the ‘-var-set-format’ command. d41989 1 a41989 1 Note that one must invoke ‘-var-list-children’ for a variable before d41992 1 a41992 1 The ‘-var-assign’ Command d42001 1 a42001 1 NAME. The object must be ‘editable’. If the variable's value is d42003 1 a42003 1 ‘-var-update’ list. d42016 1 a42016 1 The ‘-var-update’ Command d42026 4 a42029 4 variable objects whose values have changed; NAME must be a root variable object. Here, "changed" means that the result of ‘-var-evaluate-expression’ before and after the ‘-var-update’ is different. If ‘*’ is used as the variable object names, all existing d42033 2 a42034 2 this option are the same as for ‘-var-list-children’ (*note -var-list-children::). It is recommended to use the ‘--all-values’ d42037 1 a42037 1 With the ‘*’ parameter, if a variable object is bound to a currently d42040 2 a42041 2 If ‘-var-set-update-range’ was previously used on a varobj, then only the selected range of children will be reported. d42043 2 a42044 2 ‘-var-update’ reports all the changed varobjs in a tuple named ‘changelist’. d42048 1 a42048 1 ‘name’ d42051 1 a42051 1 ‘value’ d42055 1 a42055 1 ‘in_scope’ d42058 1 a42058 1 ‘"true"’ d42061 1 a42061 1 ‘"false"’ d42066 1 a42066 1 ‘"invalid"’ d42069 3 a42071 3 either through recompilation or by using the GDB ‘file’ command. The front end should normally choose to delete these variable objects. d42077 1 a42077 1 ‘type_changed’ d42079 2 a42080 2 changed, then this will be the string ‘true’; otherwise it will be ‘false’. d42084 2 a42085 2 automatically deleted when this attribute is ‘true’. Also, the varobj's update range, when set using the ‘-var-set-update-range’ d42088 1 a42088 1 ‘new_type’ d42092 1 a42092 1 ‘new_num_children’ d42096 1 a42096 1 The ‘numchild’ field in other varobj responses is generally not d42102 4 a42105 4 The ‘new_num_children’ attribute only reports changes to the number of children known by GDB. This is the only way to detect whether an update has removed children (which necessarily can only happen at the end of the update range). d42107 1 a42107 1 ‘displayhint’ d42110 1 a42110 1 ‘has_more’ d42114 4 a42117 4 ‘dynamic’ This attribute will be present and have the value ‘1’ if the varobj is a dynamic varobj. If the varobj is not a dynamic varobj, then this attribute will not be present. d42119 1 a42119 1 ‘new_children’ d42121 2 a42122 2 update range (as set by ‘-var-set-update-range’), then they will be listed in this attribute. d42136 1 a42136 1 The ‘-var-set-frozen’ Command d42145 1 a42145 1 parameter should be either ‘1’ to make the variable frozen or ‘0’ to d42147 6 a42152 6 nor any of its children, are implicitly updated by ‘-var-update’ of a parent variable or by ‘-var-update *’. Only ‘-var-update’ of the variable itself will update its value and values of its children. After a variable object is unfrozen, it is implicitly updated by all subsequent ‘-var-update’ operations. Unfreezing a variable does not update it, only subsequent ‘-var-update’ does. d42162 1 a42162 1 The ‘-var-set-update-range’ command d42171 1 a42171 1 ‘-var-update’. d42174 3 a42176 3 is less than zero, the range is reset and all children will be reported. Otherwise, children starting at FROM (zero-based) and up to and excluding TO will be reported. d42185 1 a42185 1 The ‘-var-set-visualizer’ command d42195 1 a42195 1 VISUALIZER is the visualizer to use. The special value ‘None’ means d42198 1 a42198 1 If not ‘None’, VISUALIZER must be a Python expression. This d42202 3 a42204 3 code can be used for both the CLI and MI). When called, this object must return an object which conforms to the pretty-printing interface (*note Pretty Printing API::). d42206 1 a42206 1 The pre-defined function ‘gdb.default_visualizer’ may be used to d42212 1 a42212 1 command ‘-list-features’ (*note GDB/MI Support Commands::) can be used d42230 1 a42230 1 Suppose ‘SomeClass’ is a visualizer class. A lambda expression can d42243 2 a42244 2 This section describes the GDB/MI commands that manipulate data: examine memory and registers, evaluate expressions, etc. d42249 1 a42249 1 The ‘-data-disassemble’ Command d42265 4 a42268 3 ‘START-ADDR’ is the beginning address (or ‘$pc’) ‘END-ADDR’ d42270 2 a42271 1 ‘ADDR’ d42276 2 a42277 1 ‘FILENAME’ d42279 2 a42280 1 ‘LINENUM’ d42282 2 a42283 1 ‘LINES’ d42286 7 a42292 6 specified. If END-ADDR is specified as a non-zero value, and LINES is lower than the number of disassembly lines between START-ADDR and END-ADDR, only LINES lines are displayed; if LINES is higher than the number of lines between START-ADDR and END-ADDR, only the lines up to END-ADDR are displayed. ‘OPCODES-MODE’ d42294 1 a42294 1 ‘none’ d42297 1 a42297 1 ‘bytes’ d42299 1 a42299 1 formatted as for ‘disassemble /b’. d42301 1 a42301 1 ‘display’ d42303 5 a42307 4 formatted as for ‘disassemble /r’. ‘MODE’ the use of MODE is deprecated in favour of using the ‘--opcodes’ and ‘--source’ options. When no MODE is given, MODE 0 will be d42310 1 a42310 1 ‘0’ d42314 1 a42314 1 ‘1’ d42316 2 a42317 2 possible to recreate this mode using ‘--opcodes’ and ‘--source’ options. d42319 1 a42319 1 ‘2’ d42321 1 a42321 1 using MODE 0 and passing ‘--opcodes bytes’ to the command. d42323 1 a42323 1 ‘3’ d42325 2 a42326 2 it is not possible to recreate this mode using ‘--opcodes’ and ‘--source’ options. d42328 1 a42328 1 ‘4’ d42330 1 a42330 1 using MODE 0 and passing ‘--source’ to the command. d42332 1 a42332 1 ‘5’ d42334 10 a42343 10 equivalent to using MODE 0 and passing ‘--opcodes bytes’ and ‘--source’ to the command. Modes 1 and 3 are deprecated. The output is "source centric" which hasn't proved useful in practice. *Note Machine Code::, for a discussion of the difference between ‘/m’ and ‘/s’ output of the ‘disassemble’ command. The ‘--source’ can only be used with MODE 0. Passing this option will include the source code in the disassembly result as if MODE 4 or 5 had been used. d42348 3 a42350 3 The result of the ‘-data-disassemble’ command will be a list named ‘asm_insns’, the contents of this list depend on the options used with the ‘-data-disassemble’ command. d42352 2 a42353 2 For modes 0 and 2, and when the ‘--source’ option is not used, the ‘asm_insns’ list contains tuples with the following fields: d42355 1 a42355 1 ‘address’ d42358 1 a42358 1 ‘func-name’ d42361 2 a42362 2 ‘offset’ The decimal offset in bytes from the start of ‘func-name’. d42364 2 a42365 2 ‘inst’ The text disassembly for this ‘address’. d42367 1 a42367 1 ‘opcodes’ d42369 2 a42370 2 ‘--opcodes’ option ‘bytes’ or ‘display’ is used. This contains the raw opcode bytes for the ‘inst’ field. d42372 6 a42377 6 When the ‘--opcodes’ option is not passed to ‘-data-disassemble’, or the ‘bytes’ value is passed to ‘--opcodes’, then the bytes are formatted as a series of single bytes, in hex, in ascending address order, with a single space between each byte. This format is equivalent to the ‘/b’ option being used with the ‘disassemble’ command (*note ‘disassemble’: disassemble.). d42379 1 a42379 1 When ‘--opcodes’ is passed the value ‘display’ then the bytes are d42382 2 a42383 2 byte-swapped. This format is equivalent to the ‘/r’ option being used with the ‘disassemble’ command. d42385 3 a42387 3 For modes 1, 3, 4 and 5, or when the ‘--source’ option is used, the ‘asm_insns’ list contains tuples named ‘src_and_asm_line’, each of which has the following fields: d42389 2 a42390 2 ‘line’ The line number within ‘file’. d42392 1 a42392 1 ‘file’ d42397 2 a42398 2 ‘fullname’ Absolute file name of ‘file’. It is converted to a canonical form d42400 1 a42400 1 Directories: Source Path.) and after resolving all the symbolic d42406 5 a42410 5 ‘line_asm_insn’ This is a list of tuples containing the disassembly for ‘line’ in ‘file’. The fields of each tuple are the same as for ‘-data-disassemble’ in MODE 0 and 2, so ‘address’, ‘func-name’, ‘offset’, ‘inst’, and optionally ‘opcodes’. d42412 2 a42413 1 Note that whatever included in the ‘inst’ field, is not manipulated d42419 1 a42419 1 The corresponding GDB command is ‘disassemble’. d42424 1 a42424 1 Disassemble from the current value of ‘$pc’ to ‘$pc + 20’: d42442 1 a42442 1 Disassemble the whole ‘main’ function. Line 32 is part of ‘main’. d42457 1 a42457 1 Disassemble 3 instructions from the start of ‘main’: d42470 1 a42470 1 Disassemble 3 instructions from the start of ‘main’ in mixed mode: d42489 1 a42489 1 The ‘-data-evaluate-expression’ Command d42504 2 a42505 2 The corresponding GDB commands are ‘print’, ‘output’, and ‘call’. In ‘gdbtk’ only, there's a corresponding ‘gdb_eval’ command. d42511 1 a42511 1 “tokens” described in *note GDB/MI Command Syntax: GDB/MI Command d42527 1 a42527 1 The ‘-data-list-changed-registers’ Command d42540 2 a42541 2 GDB doesn't have a direct analog for this command; ‘gdbtk’ has the corresponding command ‘gdb_changed_register_list’. d42563 1 a42563 1 The ‘-data-list-register-names’ Command d42582 2 a42583 2 ‘-data-list-register-names’. In ‘gdbtk’ there is a corresponding command ‘gdb_regnames’. d42603 1 a42603 1 The ‘-data-list-register-values’ Command d42610 1 a42610 1 [ --skip-unavailable ] FMT [ ( REGNO )*] d42614 4 a42617 4 optional list of numbers specifying the registers to display. A missing list of numbers indicates that the contents of all the registers must be returned. The ‘--skip-unavailable’ option indicates that only the available registers are to be returned. d42621 1 a42621 1 ‘x’ d42623 2 a42624 1 ‘o’ d42626 2 a42627 1 ‘t’ d42629 2 a42630 1 ‘d’ d42632 2 a42633 1 ‘r’ d42635 2 a42636 1 ‘N’ d42642 2 a42643 2 The corresponding GDB commands are ‘info reg’, ‘info all-reg’, and (in ‘gdbtk’) ‘gdb_fetch_registers’. d42695 1 a42695 1 The ‘-data-read-memory’ Command d42698 1 a42698 1 This command is deprecated, use ‘-data-read-memory-bytes’ instead. d42709 1 a42709 1 ‘ADDRESS’ d42714 1 a42714 1 ‘WORD-FORMAT’ d42716 2 a42717 2 the same as for GDB's ‘print’ command (*note Output Formats: Output Formats.). d42719 1 a42719 1 ‘WORD-SIZE’ d42722 1 a42722 1 ‘NR-ROWS’ d42725 1 a42725 1 ‘NR-COLS’ d42728 1 a42728 1 ‘ASCHAR’ d42735 1 a42735 1 ‘BYTE-OFFSET’ d42739 6 a42744 6 NR-COLS words, each word being WORD-SIZE bytes. In total, ‘NR-ROWS * NR-COLS * WORD-SIZE’ bytes are read (returned as ‘total-bytes’). Should less than the requested number of bytes be returned by the target, the missing words are identified using ‘N/A’. The number of bytes read from the target is returned in ‘nr-bytes’ and the starting address used to read memory in ‘addr’. d42747 1 a42747 1 ‘next-row’ and ‘prev-row’, ‘next-page’ and ‘prev-page’. d42752 1 a42752 1 The corresponding GDB command is ‘x’. ‘gdbtk’ has ‘gdb_get_mem’ memory d42758 1 a42758 1 Read six bytes of memory starting at ‘bytes+6’ but then offset by ‘-6’ d42772 1 a42772 1 Read two bytes of memory starting at address ‘shorts + 64’ and d42783 2 a42784 2 Read thirty two bytes of memory starting at ‘bytes+16’ and format as eight rows of four columns. Include a string encoding with ‘x’ used as d42802 1 a42802 1 The ‘-data-read-memory-bytes’ Command d42813 1 a42813 1 ‘ADDRESS’ d42818 1 a42818 1 ‘COUNT’ d42822 1 a42822 1 ‘OFFSET’ d42825 3 a42827 2 frontend is not required to first evaluate address and then perform address arithmetic itself. d42836 3 a42838 3 In general, every single memory unit in the region may be readable or not, and the only way to read every readable unit is to try a read at every address, which is not practical. Therefore, GDB will attempt to d42842 2 a42843 2 readable range that is neither at the beginning or the end, GDB will not read it. d42846 1 a42846 1 the command includes a field named ‘memory’ whose content is a list of d42850 1 a42850 1 ‘begin’ d42853 1 a42853 1 ‘end’ d42856 1 a42856 1 ‘offset’ d42858 1 a42858 1 the start address passed to ‘-data-read-memory-bytes’. d42860 1 a42860 1 ‘contents’ d42863 1 d42867 1 a42867 1 The corresponding GDB command is ‘x’. d42879 1 a42879 1 The ‘-data-write-memory-bytes’ Command d42890 1 a42890 1 ‘ADDRESS’ d42892 12 a42903 2 memory unit to be written. Complex expressions containing embedded white space should be quoted using the C convention. a42904 8 ‘CONTENTS’ The hex-encoded data to write. It is an error if CONTENTS does not represent an integral number of addressable memory units. ‘COUNT’ Optional argument indicating the number of addressable memory units to be written. If COUNT is greater than CONTENTS' length, GDB will repeatedly write CONTENTS until it fills COUNT memory units. d42931 1 a42931 1 tracepoints. For detailed introduction, see *note Tracepoints::. d42933 1 a42933 1 The ‘-trace-find’ Command d42943 1 a42943 1 details of operation, see *note tfind::. d42945 1 a42945 1 ‘none’ d42948 1 a42948 1 ‘frame-number’ d42952 1 a42952 1 ‘tracepoint-number’ d42956 1 a42956 1 ‘pc’ d42960 1 a42960 1 ‘pc-inside-range’ d42962 3 a42964 2 that corresponds to a tracepoint at an address inside the specified range. Both bounds are considered to be inside the range. d42966 1 a42966 1 ‘pc-outside-range’ d42972 1 a42972 1 ‘line’ d42977 2 a42978 1 If ‘none’ was passed as MODE, the response does not have fields. d42981 3 a42983 3 ‘found’ This field has either ‘0’ or ‘1’ as the value, depending on whether a matching tracepoint was found. d42985 1 a42985 1 ‘traceframe’ d42987 1 a42987 1 ‘found’ field has value of ‘1’. d42989 1 a42989 1 ‘tracepoint’ d42991 1 a42991 1 ‘found’ field has value of ‘1’. d42993 1 a42993 1 ‘frame’ d42998 1 d43002 1 a43002 1 The corresponding GDB command is ‘tfind’. d43004 1 a43004 1 The ‘-trace-define-variable’ Command d43014 1 a43014 1 that value. Note that the NAME should start with the ‘$’ character. d43019 1 a43019 1 The corresponding GDB command is ‘tvariable’. d43021 1 a43021 1 The ‘-trace-frame-collected’ Command d43039 5 a43043 5 The reported names can be used in the normal manner to create varobjs and inspect the objects themselves. The items returned by this command are categorized so that it is clear which is a variable, which is a register, which is a trace state variable, which is a memory range and which is a computed expression. d43049 3 a43051 3 the object collected in its entirety would be ‘myVar’. The object ‘myArray’ would be partially collected, because only the element at index ‘myIndex’ would be collected. The remaining objects would be d43077 1 a43077 1 ‘explicit-variables’ d43081 1 a43081 1 The ‘--var-print-values’ option affects how or whether the value d43087 1 a43087 1 ‘computed-expressions’ d43089 3 a43091 3 current trace frame. The ‘--comp-print-values’ option affects this set like the ‘--var-print-values’ option affects the ‘explicit-variables’ set. See above. d43093 1 a43093 1 ‘registers’ d43097 2 a43098 2 ‘--registers-format’ option. See the ‘-data-list-register-values’ command for a list of the allowed formats. The default is ‘x’. d43100 1 a43100 1 ‘tvars’ d43105 1 a43105 1 ‘memory’ d43110 1 a43110 1 ‘address’ d43113 1 a43113 1 ‘length’ d43116 1 a43116 1 ‘contents’ d43118 3 a43120 1 present if the ‘--memory-contents’ option is specified. d43130 1 a43130 1 The ‘-trace-list-variables’ Command d43141 1 a43141 1 ‘name’ d43144 3 a43146 3 ‘initial’ The initial value. This is a 64-bit signed integer. This field is always present. d43148 1 a43148 1 ‘current’ d43154 1 d43158 1 a43158 1 The corresponding GDB command is ‘tvariables’. d43173 1 a43173 1 The ‘-trace-save’ Command d43181 3 a43183 3 Saves the collected trace data to FILENAME. Without the ‘-r’ option, the data is downloaded from the target and saved in a local file. With the ‘-r’ option the target is asked to perform the save. d43186 2 a43187 2 You can supply the optional ‘-ctf’ argument to save it the CTF format. See *note Trace Files:: for more information about CTF. d43192 1 a43192 1 The corresponding GDB command is ‘tsave’. d43194 1 a43194 1 The ‘-trace-start’ Command d43208 1 a43208 1 The corresponding GDB command is ‘tstart’. d43210 1 a43210 1 The ‘-trace-status’ Command d43221 5 a43225 5 ‘supported’ May have a value of either ‘0’, when no tracing operations are supported, ‘1’, when all tracing operations are supported, or ‘file’ when examining trace file. In the latter case, examining of trace frame is possible but new tracing experiment cannot be d43228 2 a43229 2 ‘running’ May have a value of either ‘0’ or ‘1’ depending on whether tracing d43231 1 a43231 1 ‘supported’ field is not ‘0’. d43233 1 a43233 1 ‘stop-reason’ d43236 7 a43242 7 The value of ‘request’ means the tracing was stopped as result of the ‘-trace-stop’ command. The value of ‘overflow’ means the tracing buffer is full. The value of ‘disconnection’ means tracing was automatically stopped when GDB has disconnected. The value of ‘passcount’ means tracing was stopped when a tracepoint was passed a maximal number of times for that tracepoint. This field is present if ‘supported’ field is not ‘0’. d43244 1 a43244 1 ‘stopping-tracepoint’ d43246 2 a43247 2 is present iff the ‘stop-reason’ field has the value of ‘passcount’. d43249 4 a43252 4 ‘frames’ ‘frames-created’ The ‘frames’ field is a count of the total number of trace frames in the trace buffer, while ‘frames-created’ is the total created d43256 2 a43257 2 ‘buffer-size’ ‘buffer-free’ d43261 2 a43262 2 ‘circular’ The value of the circular trace buffer flag. ‘1’ means that the d43264 1 a43264 1 necessary to make room, ‘0’ means that the trace buffer is linear d43267 4 a43270 4 ‘disconnected’ The value of the disconnected tracing flag. ‘1’ means that tracing will continue after GDB disconnects, ‘0’ means that the trace run will stop. d43272 1 a43272 1 ‘trace-file’ d43276 1 d43280 1 a43280 1 The corresponding GDB command is ‘tstatus’. d43282 1 a43282 1 The ‘-trace-stop’ Command d43291 1 a43291 1 fields as ‘-trace-status’, except that the ‘supported’ and ‘running’ d43297 1 a43297 1 The corresponding GDB command is ‘tstop’. d43305 1 a43305 1 The ‘-symbol-info-functions’ Command d43320 1 a43320 1 The ‘--include-nondebug’ option causes the output to include code d43323 3 a43325 3 The options ‘--type’ and ‘--name’ allow the symbols returned to be filtered based on either the name of the function, or the type signature of the function. d43327 1 a43327 1 The option ‘--max-results’ restricts the command to return no more d43334 1 a43334 1 The corresponding GDB command is ‘info functions’. d43405 1 a43405 1 The ‘-symbol-info-module-functions’ Command d43417 2 a43418 2 containing module, and shown with the line number on which each function is defined. d43420 3 a43422 3 The option ‘--module’ only returns results for modules matching MODULE_REGEXP. The option ‘--name’ only returns functions whose name matches NAME_REGEXP, and ‘--type’ only returns functions whose type d43428 1 a43428 1 The corresponding GDB command is ‘info module functions’. d43466 1 a43466 1 The ‘-symbol-info-module-variables’ Command d43478 2 a43479 2 containing module, and shown with the line number on which each variable is defined. d43481 3 a43483 3 The option ‘--module’ only returns results for modules matching MODULE_REGEXP. The option ‘--name’ only returns variables whose name matches NAME_REGEXP, and ‘--type’ only returns variables whose type d43489 1 a43489 1 The corresponding GDB command is ‘info module variables’. d43537 1 a43537 1 The ‘-symbol-info-modules’ Command a43545 1 d43550 1 a43550 1 The option ‘--name’ allows the modules returned to be filtered based d43553 1 a43553 1 The option ‘--max-results’ restricts the command to return no more d43560 1 a43560 1 The corresponding GDB command is ‘info modules’. d43590 1 a43590 1 The ‘-symbol-info-types’ Command a43598 1 d43602 2 a43603 2 added to the debug information by the compiler, for example ‘int’, ‘float’, etc.; these types do not have an associated line number. d43605 1 a43605 1 The option ‘--name’ allows the list of types returned to be filtered d43608 1 a43608 1 The option ‘--max-results’ restricts the command to return no more d43615 1 a43615 1 The corresponding GDB command is ‘info types’. d43646 1 a43646 1 The ‘-symbol-info-variables’ Command a43656 1 d43661 1 a43661 1 The ‘--include-nondebug’ option causes the output to include data d43664 1 a43664 1 The options ‘--type’ and ‘--name’ allow the symbols returned to be d43668 1 a43668 1 The option ‘--max-results’ restricts the command to return no more d43675 1 a43675 1 The corresponding GDB command is ‘info variables’. d43750 1 a43750 1 The ‘-symbol-list-lines’ Command d43759 2 a43760 2 program addresses for the given source filename. The entries are sorted in ascending PC order. d43784 1 a43784 1 The ‘-file-exec-and-symbols’ Command d43802 1 a43802 1 The corresponding GDB command is ‘file’. d43812 1 a43812 1 The ‘-file-exec-file’ Command d43821 2 a43822 2 ‘-file-exec-and-symbols’, the symbol table is _not_ read from this file. If used without argument, GDB clears the information about the d43829 1 a43829 1 The corresponding GDB command is ‘exec-file’. d43839 1 a43839 1 The ‘-file-list-exec-source-file’ Command d43849 1 a43849 1 information field has a value of ‘1’ or ‘0’ depending on whether or not d43855 1 a43855 1 The GDB equivalent is ‘info source’ d43865 1 a43865 1 The ‘-file-list-exec-source-files’ Command d43871 2 a43872 2 -file-list-exec-source-files [ --GROUP-BY-OBJFILE ] [ --DIRNAME | --BASENAME ] d43886 6 a43891 6 field DEBUG-FULLY-READ will be a string, either ‘true’ or ‘false’. When ‘true’, this indicates the full debug information for the compilation unit describing this file has been read in. When ‘false’, the full debug information has not yet been read in. While reading in the full debug information it is possible that GDB could become aware of additional source files. d43894 11 a43904 11 returned. The REGEXP will be matched against the full source file name. The matching is case-sensitive, except on operating systems that have case-insensitive filesystem (e.g., MS-Windows). ‘--’ can be used before REGEXP to prevent GDB interpreting REGEXP as a command option (e.g. if REGEXP starts with ‘-’). If ‘--dirname’ is provided, then REGEXP is matched only against the directory name of each source file. If ‘--basename’ is provided, then REGEXP is matched against the basename of each source file. Only one of ‘--dirname’ or ‘--basename’ may be given, and if either is given then REGEXP is required. d43906 1 a43906 1 If ‘--group-by-objfile’ is used then the format of the results is d43909 3 a43911 3 GDB. The fields of these tuples are; FILENAME, DEBUG-INFO, and SOURCES. The FILENAME is the absolute name of the object file, DEBUG-INFO is a string with one of the following values: d43913 1 a43913 1 ‘none’ d43915 2 a43916 1 ‘partially-read’ d43920 2 a43921 1 ‘fully-read’ d43923 1 a43923 1 fully read into GDB. The list of source files is complete. d43932 2 a43933 2 The GDB equivalent is ‘info sources’. ‘gdbtk’ has an analogous command ‘gdb_listfiles’. d43999 1 a43999 1 The ‘-file-list-shared-libraries’ Command d44013 2 a44014 2 The corresponding GDB command is ‘info shared’. The fields have a similar meaning to the ‘=library-loaded’ notification. The ‘ranges’ d44018 1 a44018 1 ‘from’ d44020 2 a44021 1 ‘to’ d44034 1 a44034 1 The ‘-file-symbol-file’ Command d44049 1 a44049 1 The corresponding GDB command is ‘symbol-file’. d44065 1 a44065 1 The ‘-target-attach’ Command d44075 1 a44075 1 by ‘-list-thread-groups --available’ must be used. d44080 1 a44080 1 The corresponding GDB command is ‘attach’. d44092 1 a44092 1 The ‘-target-detach’ Command d44107 1 a44107 1 The corresponding GDB command is ‘detach’. d44117 1 a44117 1 The ‘-target-disconnect’ Command d44131 1 a44131 1 The corresponding GDB command is ‘disconnect’. d44141 1 a44141 1 The ‘-target-download’ Command d44149 2 a44150 2 Loads the executable onto the remote target. It prints out an update message every half second, which includes the fields: d44152 1 a44152 1 ‘section’ d44154 2 a44155 1 ‘section-sent’ d44157 2 a44158 1 ‘section-size’ d44160 2 a44161 1 ‘total-sent’ d44164 2 a44165 1 ‘total-size’ d44174 1 a44174 1 ‘section’ d44176 2 a44177 1 ‘section-size’ d44179 2 a44180 1 ‘total-size’ d44188 1 a44188 1 The corresponding GDB command is ‘load’. d44254 1 a44254 1 The ‘-target-flash-erase’ Command d44264 1 a44264 1 The corresponding GDB command is ‘flash-erase’. d44274 1 a44274 1 The ‘-target-select’ Command d44284 6 a44289 5 ‘TYPE’ The type of target, for instance ‘remote’, etc. ‘PARAMETERS’ Device names, host names and the like. *Note Commands for Managing Targets: Target Commands, for more details. d44300 1 a44300 1 The corresponding GDB command is ‘target’. d44316 1 a44316 1 The ‘-target-file-put’ Command d44330 1 a44330 1 The corresponding GDB command is ‘remote put’. d44340 1 a44340 1 The ‘-target-file-get’ Command d44354 1 a44354 1 The corresponding GDB command is ‘remote get’. d44364 1 a44364 1 The ‘-target-file-delete’ Command d44377 1 a44377 1 The corresponding GDB command is ‘remote delete’. d44393 1 a44393 1 The ‘-info-ada-exceptions’ Command d44408 1 a44408 1 The corresponding GDB command is ‘info exceptions’. d44416 1 a44416 1 ‘name’ d44419 1 a44419 1 ‘address’ d44422 1 d44437 1 a44437 1 exception are described at *note Ada Exception GDB/MI Catchpoint d44448 2 a44449 2 support for these capabilities. Similarly, it is also possible to query GDB about target support of certain features. d44451 1 a44451 1 The ‘-info-gdb-mi-command’ Command d44461 1 a44461 1 Note that the dash (‘-’) starting all GDB/MI commands is technically d44476 4 a44479 3 ‘exists’ This field is equal to ‘"true"’ if the GDB/MI command exists, ‘"false"’ otherwise. d44495 1 a44495 1 The ‘-list-features’ Command d44516 7 a44522 6 ‘frozen-varobjs’ Indicates support for the ‘-var-set-frozen’ command, as well as possible presence of the ‘frozen’ field in the output of ‘-varobj-create’. ‘pending-breakpoints’ Indicates support for the ‘-f’ option to the ‘-break-insert’ d44524 2 a44525 1 ‘python’ d44527 11 a44537 8 commands, and possible presence of the ‘display_hint’ field in the output of ‘-var-list-children’ ‘thread-info’ Indicates support for the ‘-thread-info’ command. ‘data-read-memory-bytes’ Indicates support for the ‘-data-read-memory-bytes’ and the ‘-data-write-memory-bytes’ commands. ‘breakpoint-notifications’ d44540 6 a44545 4 ‘ada-task-info’ Indicates support for the ‘-ada-task-info’ command. ‘language-option’ Indicates that all GDB/MI commands accept the ‘--language’ option d44547 5 a44551 3 ‘info-gdb-mi-command’ Indicates support for the ‘-info-gdb-mi-command’ command. ‘undefined-command-error-code’ d44553 5 a44557 4 result records, produced when trying to execute an undefined GDB/MI command (*note GDB/MI Result Records::). ‘exec-run-start-option’ Indicates that the ‘-exec-run’ command supports the ‘--start’ d44559 3 a44561 2 ‘data-disassemble-a-option’ Indicates that the ‘-data-disassemble’ command supports the ‘-a’ a44562 7 ‘simple-values-ref-types’ Indicates that the ‘--simple-values’ argument to the ‘-stack-list-arguments’, ‘-stack-list-locals’, ‘-stack-list-variables’, and ‘-var-list-children’ commands takes reference types into account: that is, a value is considered simple if it is neither an array, structure, or union, nor a reference to an array, structure, or union. d44564 9 a44572 1 The ‘-list-target-features’ Command d44576 6 a44581 6 Those features affect the permitted MI commands, but unlike the features reported by the ‘-list-features’ command, the features depend on which target GDB is using at the moment. Whenever a target can change, due to commands such as ‘-target-select’, ‘-target-attach’ or ‘-exec-run’, the list of target features may change, and the frontend should obtain it again. Example output: d44588 1 a44588 1 ‘async’ d44593 1 a44593 1 ‘reverse’ d44597 1 d44604 1 a44604 1 The ‘-gdb-exit’ Command d44617 1 a44617 1 Approximately corresponds to ‘quit’. d44626 1 a44626 1 The ‘-gdb-set’ Command d44639 1 a44639 1 The corresponding GDB command is ‘set’. d44649 1 a44649 1 The ‘-gdb-show’ Command d44662 1 a44662 1 The corresponding GDB command is ‘show’. d44672 1 a44672 1 The ‘-gdb-version’ Command d44685 1 a44685 1 The GDB equivalent is ‘show version’. GDB by default shows this d44706 1 a44706 1 The ‘-list-thread-groups’ Command d44715 4 a44718 4 group is passed as the argument, lists the children of that group. When several thread group are passed, lists information about those thread groups. Without any parameters, lists information about all top-level thread groups. d44721 1 a44721 1 the ‘--available’ option, GDB reports thread groups available on the d44724 8 a44731 8 The output of this command may have either a ‘threads’ result or a ‘groups’ result. The ‘thread’ result has a list of tuples as value, with each tuple describing a thread (*note GDB/MI Thread Information::). The ‘groups’ result has a list of tuples as value, each tuple describing a thread group. If top-level groups are requested (that is, no parameter is passed), or when several groups are passed, the output always has a ‘groups’ result. The format of the ‘group’ result is described below. d44734 1 a44734 1 groups together with their children, by passing the ‘--recurse’ option d44737 1 a44737 1 will also include its children, either as ‘group’ or ‘threads’ field. d44742 12 a44753 10 • When a single thread group is passed, the output will typically be the ‘threads’ result. Because threads may not contain anything, the ‘recurse’ option will be ignored. • When the ‘--available’ option is passed, limited information may be available. In particular, the list of threads of a process might be inaccessible. Further, specifying specific thread groups might not give any performance advantage over listing all thread groups. The frontend should assume that ‘-list-thread-groups --available’ is always an expensive operation and cache the results. d44755 1 a44755 1 The ‘groups’ result is a list of tuples, where each tuple may have d44758 4 a44761 4 ‘id’ Identifier of the thread group. This field is always present. The identifier is an opaque string; frontends should not try to convert it to an integer, even though it might look like one. d44763 2 a44764 2 ‘type’ The type of the thread group. At present, only ‘process’ is a d44767 1 a44767 1 ‘pid’ d44769 1 a44769 1 for thread groups of type ‘process’ and only if the process exists. d44771 1 a44771 1 ‘exit-code’ d44774 1 a44774 1 ‘process’ and only if the process is not running. d44776 1 a44776 1 ‘num_children’ d44780 1 a44780 1 ‘threads’ d44782 1 a44782 1 thread. It may be present if the ‘--recurse’ option is specified, d44785 1 a44785 1 ‘cores’ d44790 1 a44790 1 ‘executable’ d44793 2 a44794 1 ‘process’, and only if there is a corresponding executable file. d44819 1 a44819 1 The ‘-info-os’ Command d44838 1 a44838 1 The corresponding GDB command is ‘info os’. d44887 2 a44888 2 (Note that the MI output here includes a ‘"Title"’ column that does not appear in command-line ‘info os’; this column is useful for MI d44890 1 a44890 1 menu, but is needless clutter on the command line, and ‘info os’ omits d44893 1 a44893 1 The ‘-add-inferior’ Command d44903 1 a44903 1 association may be established with the ‘-file-exec-and-symbols’ command d44908 6 a44913 6 inferior was connected to ‘gdbserver’ with ‘target remote’, then the new inferior will be connected to the same ‘gdbserver’ instance. The ‘--no-connection’ option starts the new inferior with no connection yet. You can then for example use the ‘-target-select remote’ command to connect to some other ‘gdbserver’ instance, use ‘-exec-run’ to spawn a local program, etc. d44915 2 a44916 2 The command response always has a field, INFERIOR, whose value is the identifier of the thread group corresponding to the new inferior. d44923 1 a44923 1 ‘number’ d44926 1 a44926 1 ‘name’ d44932 1 a44932 1 The corresponding GDB command is ‘add-inferior’ (*note ‘add-inferior’: d44942 1 a44942 1 The ‘-remove-inferior’ Command d44953 1 a44953 1 the ‘-add-inferior’ command. d44955 1 a44955 1 When an inferior is successfully removed a ‘=thread-group-removed’ d44962 2 a44963 2 The corresponding GDB command is ‘remove-inferiors’ (*note ‘remove-inferiors’: remove_inferiors_cli.). d44973 1 a44973 1 The ‘-interpreter-exec’ Command d44986 1 a44986 1 The corresponding GDB command is ‘interpreter-exec’. d44999 1 a44999 1 The ‘-inferior-tty-set’ Command d45012 1 a45012 1 The corresponding GDB command is ‘set inferior-tty’ /dev/pts/1. d45022 1 a45022 1 The ‘-inferior-tty-show’ Command d45035 1 a45035 1 The corresponding GDB command is ‘show inferior-tty’. d45048 1 a45048 1 The ‘-enable-timings’ Command d45059 1 a45059 1 equivalent to ‘yes’. d45092 1 a45092 1 The ‘-complete’ Command d45111 3 a45113 3 ‘completion’ This field contains the completed COMMAND. If COMMAND has no known completions, this field is omitted. d45115 1 a45115 1 ‘matches’ d45119 5 a45123 4 ‘max_completions_reached’ This field contains ‘1’ if number of known completions is above ‘max-completions’ limit (*note Completion::), otherwise it contains ‘0’. It is always present. d45128 1 a45128 1 The corresponding GDB command is ‘complete’. a45154 1 d45161 2 a45162 2 This chapter describes annotations in GDB. Annotations were designed to interface GDB to graphical user interfaces or other similar programs d45165 2 a45166 2 The annotation mechanism has largely been superseded by GDB/MI (*note GDB/MI::). d45185 1 a45185 1 Annotations start with a newline character, two ‘control-z’ characters, d45193 1 a45193 1 Any output not beginning with a newline and two ‘control-z’ d45195 1 a45195 1 for GDB to output a newline followed by two ‘control-z’ characters, but d45197 1 a45197 1 ‘escape’ annotation which means those three characters as output. d45199 1 a45199 1 The annotation LEVEL, which is specified using the ‘--annotate’ d45202 9 a45210 9 source lines, and other types of output. Level 0 is for no annotations, level 1 is for use when GDB is run as a subprocess of GNU Emacs, level 3 is the maximum annotation suitable for programs that control GDB, and level 2 annotations have been made obsolete (*note Limitations of the Annotation Interface: (annotate)Limitations.). ‘set annotate LEVEL’ The GDB command ‘set annotate’ sets the level of annotations to the specified LEVEL. d45212 1 a45212 1 ‘show annotate’ d45238 2 a45239 2 Here ‘quit’ is input to GDB; the rest is output from GDB. The three lines beginning ‘^Z^Z’ (where ‘^Z’ denotes a ‘control-z’ character) are d45248 1 a45248 1 If you prefix a command with ‘server ’ then it will not affect the d45251 2 a45252 2 commands can be run behind a user's back by a front-end in a transparent manner. d45254 3 a45256 3 The ‘server ’ prefix does not affect the recording of values into the value history; to print a value without recording it into the value history, use the ‘output’ command instead of the ‘print’ command. d45271 7 a45277 7 Different kinds of input each have a different “input type”. Each input type has three annotations: a ‘pre-’ annotation, which denotes the beginning of any prompt which is being output, a plain annotation, which denotes the end of the prompt, and then a ‘post-’ annotation which denotes the end of any echo which may (or may not) be associated with the input. For example, the ‘prompt’ input type features the following annotations: d45285 1 a45285 1 ‘prompt’ d45288 2 a45289 2 ‘commands’ When GDB prompts for a set of commands, like in the ‘commands’ d45293 1 a45293 1 ‘overload-choice’ d45297 1 a45297 1 ‘query’ d45301 1 a45301 1 ‘prompt-for-continue’ d45303 1 a45303 1 Don't expect this to work well; instead use ‘set height 0’ to d45323 2 a45324 2 ‘value-history-begin’ annotation is followed by a ‘error’, one cannot expect to receive the matching ‘value-history-end’. One cannot expect d45347 2 a45348 3 ‘^Z^Zframes-invalid’ The frames (for example, output from the ‘backtrace’ command) may d45351 3 a45353 4 ‘^Z^Zbreakpoints-invalid’ The breakpoints may have changed. For example, the user just added or deleted a breakpoint. d45361 2 a45362 2 When the program starts executing due to a GDB command such as ‘step’ or ‘continue’, d45370 2 a45371 2 is output. Before the ‘stopped’ annotation, a variety of annotations describe how the program stopped. d45373 1 a45373 1 ‘^Z^Zexited EXIT-STATUS’ d45377 2 a45378 2 ‘^Z^Zsignalled’ The program exited with a signal. After the ‘^Z^Zsignalled’, the d45391 3 a45393 3 where NAME is the name of the signal, such as ‘SIGILL’ or ‘SIGSEGV’, and STRING is the explanation of the signal, such as ‘Illegal Instruction’ or ‘Segmentation fault’. The arguments d45397 2 a45398 2 ‘^Z^Zsignal’ The syntax of this annotation is just like ‘signalled’, but GDB is d45402 1 a45402 1 ‘^Z^Zbreakpoint NUMBER’ d45405 1 a45405 1 ‘^Z^Zwatchpoint NUMBER’ d45418 10 a45427 10 where FILENAME is an absolute file name indicating which source file, LINE is the line number within that file (where 1 is the first line in the file), CHARACTER is the character position within the file (where 0 is the first character in the file) (for most debug formats this will necessarily point to the beginning of a line), MIDDLE is ‘middle’ if ADDR is in the middle of the line, or ‘beg’ if ADDR is at the beginning of the line, and ADDR is the address in the target program associated with the source which is being displayed. The ADDR is in the form ‘0x’ followed by one or more lowercase hex digits (note that this does not depend on the language). d45435 3 a45437 3 The Debugger Adapter Protocol is a generic API that is used by some IDEs to communicate with debuggers. It is documented at . d45442 1 a45442 1 GDB defines some parameters that can be passed to the ‘launch’ d45445 1 a45445 1 ‘args’ d45447 2 a45448 2 provided as command-line arguments to the inferior, as if by ‘set args’. *Note Arguments::. d45450 1 a45450 1 ‘cwd’ d45452 1 a45452 1 directory to this directory, as if by the ‘cd’ command (*note d45455 2 a45456 2 before the ‘program’ parameter is processed. This will affect the result if ‘program’ is a relative filename. d45458 6 a45463 6 ‘env’ If provided, this should be an object. Each key of the object will be used as the name of an environment variable; each value must be a string and will be the value of that variable. The environment of the inferior will be set to exactly as passed in. *Note Environment::. d45465 1 a45465 1 ‘program’ d45467 1 a45467 1 This corresponds to the ‘file’ command. *Note Files::. d45469 2 a45470 2 ‘stopAtBeginningOfMainSubprogram’ If provided, this must be a boolean. When ‘True’, GDB will set a d45472 1 a45472 1 same approach as the ‘start’ command. *Note Starting::. d45474 3 a45476 3 GDB defines some parameters that can be passed to the ‘attach’ request. Either ‘pid’ or ‘target’ must be specified, but if both are specified then ‘target’ will be ignored. d45478 1 a45478 1 ‘pid’ d45481 1 a45481 1 ‘program’ d45483 1 a45483 1 This corresponds to the ‘file’ command. *Note Files::. In some d45488 1 a45488 1 ‘target’ d45490 1 a45490 1 passed to the ‘target remote’ command. *Note Connecting::. d45492 1 a45492 1 In response to the ‘disassemble’ request, DAP allows the client to d45495 1 a45495 1 in hex, like ‘"55a2b900"’. d45497 1 a45497 1 When the ‘repl’ context is used for the ‘evaluate’ request, GDB d45501 1 a45501 1 For example, evaluating the ‘continue’ command could do this, as could d45504 1 a45504 1 ‘repl’ evaluation can also cause GDB to appear to stop responding to d45507 2 a45508 2 Evaluations like this can be interrupted using the DAP ‘cancel’ request. (In fact, ‘cancel’ should work for any request, but it is d45512 1 a45512 1 mode. These can be set on the command line using the ‘-iex’ option d45515 1 a45515 1 ‘set debug dap-log-file [FILENAME]’ d45519 2 a45520 2 ‘set debug dap-log-level LEVEL’ Set the DAP logging level. The default is ‘1’, which logs the DAP d45522 1 a45522 1 useful, and unexpected exceptions. Level ‘2’ can be used to log d45533 4 a45536 4 This chapter documents GDB's “just-in-time” (JIT) compilation interface. A JIT compiler is a program or library that generates native executable code at runtime and executes it, usually in order to achieve good performance while maintaining platform independence. d45555 2 a45556 2 variable to find existing code, and puts a breakpoint in the function so that it can find out about additional code. d45619 1 a45619 1 • Generate an object file in memory with symbols and other desired d45623 2 a45624 2 • Create a code entry for the file, which gives the start and size of the symbol file. d45626 1 a45626 1 • Add it to the linked list in the JIT descriptor. d45628 1 a45628 1 • Point the relevant_entry field of the descriptor at the entry. d45630 2 a45631 2 • Set ‘action_flag’ to ‘JIT_REGISTER’ and call ‘__jit_debug_register_code’. d45634 3 a45636 3 ‘relevant_entry’ pointer so it doesn't have to walk the list looking for new code. However, the linked list must still be maintained in order to allow GDB to attach to a running process and still find the symbol d45647 1 a45647 1 • Remove the code entry corresponding to the code from the linked d45650 1 a45650 1 • Point the ‘relevant_entry’ field of the descriptor at the code d45653 2 a45654 2 • Set ‘action_flag’ to ‘JIT_UNREGISTER’ and call ‘__jit_debug_register_code’. d45673 2 a45674 2 ‘gdb/jit-reader.in’, which is also installed as a header at ‘INCLUDEDIR/gdb/jit-reader.h’ for easy inclusion. d45678 2 a45679 2 at runtime). Two GDB commands, ‘jit-reader-load’ and ‘jit-reader-unload’ are provided, to be used to load and unload the d45694 2 a45695 2 Readers can be loaded and unloaded using the ‘jit-reader-load’ and ‘jit-reader-unload’ commands. d45697 1 a45697 1 ‘jit-reader-load READER’ d45701 2 a45702 2 directory, usually ‘LIBDIR/gdb/’ on a UNIX system (here LIBDIR is the system library directory, often ‘/usr/local/lib’). d45707 2 a45708 2 current one using ‘jit-reader-unload’ and then invoking ‘jit-reader-load’. d45710 1 a45710 1 ‘jit-reader-unload’ d45713 1 d45721 1 a45721 1 certain ABI. This ABI is described in ‘jit-reader.h’. d45723 1 a45723 1 ‘jit-reader.h’ defines the structures, macros and functions required d45725 1 a45725 1 ‘INCLUDEDIR/gdb’ where INCLUDEDIR is the system include directory. d45729 1 a45729 1 ‘GDB_DECLARE_GPL_COMPATIBLE_READER’ in a source file. d45731 2 a45732 2 The entry point for readers is the symbol ‘gdb_init_reader’, which is expected to be a function with the prototype d45736 1 a45736 1 ‘struct gdb_reader_funcs’ contains a set of pointers to callback d45738 2 a45739 2 generated by the JIT compiler (‘read’), to unwind stack frames (‘unwind’) and to create canonical frame IDs (‘get_frame_id’). It also d45741 1 a45741 1 (‘destroy’). The struct looks like this d45757 9 a45765 9 The callbacks are provided with another set of callbacks by GDB to do their job. For ‘read’, these callbacks are passed in a ‘struct gdb_symbol_callbacks’ and for ‘unwind’ and ‘get_frame_id’, in a ‘struct gdb_unwind_callbacks’. ‘struct gdb_symbol_callbacks’ has callbacks to create new object files and new symbol tables inside those object files. ‘struct gdb_unwind_callbacks’ has callbacks to read registers off the current frame and to write out the values of the registers in the previous frame. Both have a callback (‘target_read’) to read bytes off the target's address space. d45782 2 a45783 2 helpful about its behavior. If the program's correctness depends on its real-time behavior, delays introduced by a debugger might cause the d45789 4 a45792 4 reduce the number of operations performed by debugger. The “In-Process Agent”, a shared library, is running within the same process with inferior, and is able to perform some debugging operations itself. As a result, debugger is only involved when necessary, and performance of d45805 7 a45811 7 ‘set agent on’ Causes the in-process agent to perform some operations on behalf of the debugger. Just which operations requested by the user will be done by the in-process agent depends on the its capabilities. For example, if you request to evaluate breakpoint conditions in the in-process agent, and the in-process agent has such capability as well, then breakpoint conditions will be evaluated in the d45814 3 a45816 3 ‘set agent off’ Disables execution of debugging operations by the in-process agent. All of the operations will be performed by GDB. d45818 1 a45818 1 ‘show agent’ d45834 7 a45840 7 for communications between GDB or GDBserver and the IPA. In general, GDB or GDBserver sends commands (*note IPA Protocol Commands::) and data to in-process agent, and then in-process agent replies back with the return result of the command, or some other information. The data sent to in-process agent is composed of primitive data types, such as 4-byte or 8-byte type, and composite types, which are called objects (*note IPA Protocol Objects::). d45854 1 a45854 1 complex data types called “objects”. d45862 6 a45867 5 compiled as a 64-bit executable, while in-process agent is a 32-bit one. 2. ABI. Some machines may have multiple types of ABI, GDB or GDBserver is compiled with one, and in-process agent is compiled with the other one. d45873 5 a45877 3 2. tracepoint action object. It represents a tracepoint action (*note Tracepoint Action Lists: Tracepoint Actions.) to collect registers, memory, static trace data and to evaluate expression. d45881 1 d45886 3 a45888 3 --------------------------------------------------------------------------- _agent expression object_ d45891 3 a45893 3 _tracepoint action for collecting memory_ d45895 1 a45895 1 addr 8 if BASEREG is ‘-1’, ADDR is the d45904 3 a45906 3 _tracepoint action for collecting registers_ d45908 3 a45910 3 _tracepoint action for collecting static trace data_ d45912 3 a45914 3 _tracepoint action for expression evaluation_ d45916 2 a45917 2 agent expression length of *note agent expression object:: _tracepoint object_ d45930 9 a45938 7 condition is otherwise is NULL *note agent expression object:: otherwise length of *note agent expression object:: actions variable numactions number of *note tracepoint action object:: d45949 1 a45949 1 ‘FastTrace:TRACEPOINT_OBJECT GDB_JUMP_PAD_HEAD’ d45952 1 a45952 1 is the head of “jumppad”, which is used to jump to data collection d45956 1 a45956 1 ‘OK TARGET_ADDRESS GDB_JUMP_PAD_HEAD FJUMP_SIZE FJUMP’ d45963 2 a45964 1 ‘close’ d45968 1 a45968 1 ‘qTfSTM’ d45970 2 a45971 1 ‘qTsSTM’ d45973 2 a45974 1 ‘qTSTMat’ d45976 2 a45977 1 ‘probe_marker_at:ADDRESS’ d45981 2 a45982 1 ‘unprobe_marker_at:ADDRESS’ d46015 1 a46015 1 • If the debugger gets a fatal signal, for any input whatever, that d46018 1 a46018 1 • If GDB produces an error message for valid input, that is a bug. d46022 4 a46025 4 • If GDB does not produce an error message for invalid input, that is a bug. However, you should note that your idea of "invalid input" might be our idea of "an extension" or "support for traditional practice". d46027 1 a46027 1 • If you are an experienced user of debugging tools, your suggestions d46041 1 a46041 1 individuals in the file ‘etc/SERVICE’ in the GNU Emacs distribution. d46044 1 a46044 1 to . d46046 3 a46048 3 The fundamental principle of reporting bugs usefully is this: *report all the facts*. If you are not sure whether to state a fact or leave it out, state it! d46072 2 a46073 2 • The version of GDB. GDB announces it if you start with no arguments; you can also print it at any time using ‘show version’. d46078 1 a46078 1 • The type of machine you are using, and the operating system name d46081 3 a46083 3 • The details of the GDB build-time configuration. GDB shows these details if you invoke it with the ‘--configuration’ command-line option, or if you type ‘show configuration’ at GDB's prompt. d46085 1 a46085 1 • What compiler (and its version) was used to compile GDB--e.g. d46088 3 a46090 3 • What compiler (and its version) was used to compile the program you are debugging--e.g. "gcc-2.8.1", or "HP92453-01 A.10.32.03 HP C Compiler". For GCC, you can say ‘gcc --version’ to get this d46094 4 a46097 4 • The command arguments you gave the compiler to compile your example and observe the bug. For example, did you use ‘-O’? To guarantee you will not omit something important, list them all. A copy of the Makefile (or the output from make) is sufficient. d46102 1 a46102 1 • A complete input script, and all necessary source files, that will d46105 1 a46105 1 • A description of what behavior you observe that you believe is d46108 4 a46111 4 Of course, if the bug is that GDB gets a fatal signal, then we will certainly notice it. But if the bug is incorrect output, we might not notice unless it is glaringly wrong. You might as well not give us a chance to make a mistake. d46124 3 a46126 3 program such as ‘script’, which is available on many Unix systems. Just run your GDB session inside ‘script’ and then include the ‘typescript’ file with your bug report. d46131 1 a46131 1 • If you wish to suggest changes to the GDB source, send us context d46135 4 a46138 3 The line numbers in our development sources will not match those in your sources. Your line numbers would convey no useful information to us. d46142 1 a46142 1 • A description of the envelope of the bug. d46153 2 a46154 2 Of course, if you can find a simpler example to report _instead_ of the original one, that is a convenience for us. Errors in the d46162 1 a46162 1 • A patch for the bug. d46166 3 a46168 3 assumption that a patch is all we need. We might see problems with your patch and decide to fix the problem another way, or we might not understand it at all. d46173 2 a46174 2 not be able to construct one, so we will not be able to verify that the bug is fixed. d46180 1 a46180 1 • A guess about what the bug is or what it depends on. d46213 1 a46213 1 The text ‘C-k’ is read as 'Control-K' and describes the character d46216 1 a46216 1 The text ‘M-k’ is read as 'Meta-K' and describes the character d46227 1 a46227 1 _first_, and then typing . Either process is known as “metafying” d46230 2 a46231 2 The text ‘M-C-k’ is read as 'Meta-Control-k' and describes the character produced by “metafying” ‘C-k’. d46233 6 a46238 6 In addition, several keys have their own names. Specifically, , , , , , and all stand for themselves when seen in this text, or in an init file (*note Readline Init File::). If your keyboard lacks a key, typing will produce the desired character. The key may be labeled or on some keyboards. d46276 4 a46279 4 Sometimes you may mistype a character, and not notice the error until you have typed several other characters. In that case, you can type ‘C-b’ to move the cursor to the left, and then correct your mistake. Afterwards, you can move the cursor to the right with ‘C-f’. d46282 6 a46287 5 characters to the right of the cursor are 'pushed over' to make room for the text that you have inserted. Likewise, when you delete text behind the cursor, characters to the right of the cursor are 'pulled back' to fill in the blank space created by the removal of the text. A list of the bare essentials for editing the text of an input line follows. d46289 1 a46289 1 ‘C-b’ d46291 2 a46292 1 ‘C-f’ d46294 1 d46297 2 a46298 1 ‘C-d’ d46300 1 d46303 2 a46304 1 ‘C-_’ or ‘C-x C-u’ d46310 1 a46310 1 the character underneath the cursor, like ‘C-d’, rather than the d46320 3 a46322 3 order to do editing of the input line. For your convenience, many other commands have been added in addition to ‘C-b’, ‘C-f’, ‘C-d’, and . Here are some commands for moving more rapidly about the line. d46324 1 a46324 1 ‘C-a’ d46326 2 a46327 1 ‘C-e’ d46329 2 a46330 1 ‘M-f’ d46333 2 a46334 1 ‘M-b’ d46336 2 a46337 1 ‘C-l’ d46340 3 a46342 3 Notice how ‘C-f’ moves forward a character, while ‘M-f’ moves forward a word. It is a loose convention that control keystrokes operate on characters while meta keystrokes operate on words. d46350 4 a46353 3 “Killing” text means to delete the text from the line, but to save it away for later use, usually by “yanking” (re-inserting) it back into the line. ('Cut' and 'paste' are more recent jargon for 'kill' and 'yank'.) d46355 1 a46355 1 If the description for a command says that it 'kills' text, then you d46359 2 a46360 2 When you use a kill command, the text is saved in a “kill-ring”. Any number of consecutive kills save all of the killed text together, so d46363 1 a46363 1 available to be yanked back later, when you are typing another line. d46367 1 a46367 1 ‘C-k’ d46371 1 a46371 1 ‘M-d’ d46374 1 a46374 1 as those used by ‘M-f’. d46376 1 a46376 1 ‘M-’ d46379 5 a46383 1 same as those used by ‘M-b’. a46384 3 ‘C-w’ Kill from the cursor to the previous whitespace. This is different than ‘M-’ because the word boundaries differ. d46386 1 a46386 1 Here is how to “yank” the text back into the line. Yanking means to d46389 1 a46389 1 ‘C-y’ d46393 1 a46393 1 ‘M-y’ d46395 1 a46395 1 if the prior command is ‘C-y’ or ‘M-y’. d46408 1 a46408 1 start of the line, you might type ‘M-- C-k’. d46411 2 a46412 2 meta digits before the command. If the first 'digit' typed is a minus sign (‘-’), then the sign of the argument will be negative. Once you d46414 3 a46416 3 remainder of the digits, and then the command. For example, to give the ‘C-d’ command an argument of 10, you could type ‘M-1 0 C-d’, which will delete the next ten characters on the input line. d46424 3 a46426 3 Readline provides commands for searching through the command history for lines containing a specified string. There are two search modes: “incremental” and “non-incremental”. d46431 5 a46435 5 typed so far. An incremental search requires only as many characters as needed to find the desired history entry. To search backward in the history for a particular string, type ‘C-r’. Typing ‘C-s’ searches forward through the history. The characters present in the value of the ‘isearch-terminators’ variable are used to terminate an incremental d46437 11 a46447 11 ‘C-J’ characters will terminate an incremental search. ‘C-g’ will abort an incremental search and restore the original line. When the search is terminated, the history entry containing the search string becomes the current line. To find other matching entries in the history list, type ‘C-r’ or ‘C-s’ as appropriate. This will search backward or forward in the history for the next entry matching the search string typed so far. Any other key sequence bound to a Readline command will terminate the search and execute that command. For instance, a will terminate the search and accept the line, thereby executing the command from the d46451 3 a46453 3 Readline remembers the last incremental search string. If two ‘C-r’s are typed without any intervening characters defining a new search string, any remembered search string is used. d46465 4 a46468 4 Although the Readline library comes with a set of Emacs-like keybindings installed by default, it is possible to use a different set of keybindings. Any user can customize programs that use Readline by putting commands in an “inputrc” file, conventionally in his home d46470 3 a46472 3 environment variable ‘INPUTRC’. If that variable is unset, the default is ‘~/.inputrc’. If that file does not exist or cannot be read, the ultimate default is ‘/etc/inputrc’. d46477 1 a46477 1 In addition, the ‘C-x C-r’ command re-reads this init file, thus d46494 5 a46498 5 There are only a few basic constructs allowed in the Readline init file. Blank lines are ignored. Lines beginning with a ‘#’ are comments. Lines beginning with a ‘$’ indicate conditional constructs (*note Conditional Init Constructs::). Other lines denote variable settings and key bindings. d46502 1 a46502 1 values of variables in Readline using the ‘set’ command within the d46507 2 a46508 2 Here, for example, is how to change from the default Emacs-like key binding to use ‘vi’ line editing commands: d46516 2 a46517 2 on if the value is null or empty, ON (case-insensitive), or 1. Any other value results in the variable being set to off. d46522 11 a46532 11 ‘bell-style’ Controls what happens when Readline wants to ring the terminal bell. If set to ‘none’, Readline never rings the bell. If set to ‘visible’, Readline uses a visible bell if one is available. If set to ‘audible’ (the default), Readline attempts to ring the terminal's bell. ‘bind-tty-special-chars’ If set to ‘on’ (the default), Readline attempts to bind the control characters treated specially by the kernel's terminal driver to their Readline equivalents. d46534 2 a46535 2 ‘blink-matching-paren’ If set to ‘on’, Readline attempts to briefly move the cursor d46537 1 a46537 1 inserted. The default is ‘off’. d46539 2 a46540 2 ‘colored-completion-prefix’ If set to ‘on’, when listing completions, Readline displays d46543 2 a46544 2 value of the ‘LS_COLORS’ environment variable. The default is ‘off’. d46546 2 a46547 2 ‘colored-stats’ If set to ‘on’, Readline displays possible completions using d46549 2 a46550 2 definitions are taken from the value of the ‘LS_COLORS’ environment variable. The default is ‘off’. d46552 1 a46552 1 ‘comment-begin’ d46554 2 a46555 2 ‘insert-comment’ command is executed. The default value is ‘"#"’. d46557 1 a46557 1 ‘completion-display-width’ d46564 2 a46565 2 ‘completion-ignore-case’ If set to ‘on’, Readline performs filename matching and d46567 1 a46567 1 is ‘off’. d46569 3 a46571 3 ‘completion-map-case’ If set to ‘on’, and COMPLETION-IGNORE-CASE is enabled, Readline treats hyphens (‘-’) and underscores (‘_’) as d46573 1 a46573 1 and completion. The default value is ‘off’. d46575 1 a46575 1 ‘completion-prefix-display-length’ d46582 1 a46582 1 ‘completion-query-items’ d46588 3 a46590 3 listed. This variable must be set to an integer value greater than or equal to 0. A negative value means Readline should never ask. The default limit is ‘100’. d46592 2 a46593 2 ‘convert-meta’ If set to ‘on’, Readline will convert characters with the d46596 2 a46597 2 to a meta-prefixed key sequence. The default value is ‘on’, but will be set to ‘off’ if the locale is one that contains d46600 4 a46603 4 ‘disable-completion’ If set to ‘On’, Readline will inhibit word completion. Completion characters will be inserted into the line as if they had been mapped to ‘self-insert’. The default is ‘off’. d46605 2 a46606 2 ‘echo-control-characters’ When set to ‘on’, on operating systems that indicate they d46608 1 a46608 1 signal generated from the keyboard. The default is ‘on’. d46610 2 a46611 2 ‘editing-mode’ The ‘editing-mode’ variable controls which default set of key d46614 1 a46614 1 This variable can be set to either ‘emacs’ or ‘vi’. d46616 3 a46618 3 ‘emacs-mode-string’ If the SHOW-MODE-IN-PROMPT variable is enabled, this string is displayed immediately before the last line of the primary d46622 4 a46625 3 Use the ‘\1’ and ‘\2’ escapes to begin and end sequences of non-printing characters, which can be used to embed a terminal control sequence into the mode string. The default is ‘@@’. d46627 2 a46628 2 ‘enable-bracketed-paste’ When set to ‘On’, Readline will configure the terminal in a d46631 3 a46633 3 each character as if it had been read from the keyboard. This can prevent pasted characters from being interpreted as editing commands. The default is ‘On’. d46635 2 a46636 2 ‘enable-keypad’ When set to ‘on’, Readline will try to enable the application d46638 1 a46638 1 the arrow keys. The default is ‘off’. d46640 9 a46648 9 ‘enable-meta-key’ When set to ‘on’, Readline will try to enable any meta modifier key the terminal claims to support when it is called. On many terminals, the meta key is used to send eight-bit characters. The default is ‘on’. ‘expand-tilde’ If set to ‘on’, tilde expansion is performed when Readline attempts word completion. The default is ‘off’. d46650 2 a46651 2 ‘history-preserve-point’ If set to ‘on’, the history code attempts to place the point d46653 2 a46654 2 history line retrieved with ‘previous-history’ or ‘next-history’. The default is ‘off’. d46656 7 a46662 7 ‘history-size’ Set the maximum number of history entries saved in the history list. If set to zero, any existing history entries are deleted and no new entries are saved. If set to a value less than zero, the number of history entries is not limited. By default, the number of history entries is not limited. If an attempt is made to set HISTORY-SIZE to a non-numeric value, d46665 3 a46667 3 ‘horizontal-scroll-mode’ This variable can be set to either ‘on’ or ‘off’. Setting it to ‘on’ means that the text of the lines being edited will d46670 3 a46672 3 a new screen line. This variable is automatically set to ‘on’ for terminals of height 1. By default, this variable is set to ‘off’. d46674 2 a46675 2 ‘input-meta’ If set to ‘on’, Readline will enable eight-bit input (it will d46678 1 a46678 1 default value is ‘off’, but Readline will set it to ‘on’ if d46680 1 a46680 1 ‘meta-flag’ is a synonym for this variable. d46682 1 a46682 1 ‘isearch-terminators’ d46686 1 a46686 1 given a value, the characters and ‘C-J’ will terminate d46689 1 a46689 1 ‘keymap’ d46691 19 a46709 18 commands. Built-in ‘keymap’ names are ‘emacs’, ‘emacs-standard’, ‘emacs-meta’, ‘emacs-ctlx’, ‘vi’, ‘vi-move’, ‘vi-command’, and ‘vi-insert’. ‘vi’ is equivalent to ‘vi-command’ (‘vi-move’ is also a synonym); ‘emacs’ is equivalent to ‘emacs-standard’. Applications may add additional names. The default value is ‘emacs’. The value of the ‘editing-mode’ variable also affects the default keymap. ‘keyseq-timeout’ Specifies the duration Readline will wait for a character when reading an ambiguous key sequence (one that can form a complete key sequence using the input read so far, or can take additional input to complete a longer key sequence). If no input is received within the timeout, Readline will use the shorter but complete key sequence. Readline uses this value to determine whether or not input is available on the current input source (‘rl_instream’ by default). The value is specified in milliseconds, so a value of 1000 means that d46713 2 a46714 2 pressed to decide which key sequence to complete. The default value is ‘500’. d46716 8 a46723 8 ‘mark-directories’ If set to ‘on’, completed directory names have a slash appended. The default is ‘on’. ‘mark-modified-lines’ This variable, when set to ‘on’, causes Readline to display an asterisk (‘*’) at the start of history lines which have been modified. This variable is ‘off’ by default. d46725 2 a46726 2 ‘mark-symlinked-directories’ If set to ‘on’, completed names which are symbolic links to d46728 1 a46728 1 ‘mark-directories’). The default is ‘off’. d46730 6 a46735 6 ‘match-hidden-files’ This variable, when set to ‘on’, causes Readline to match files whose names begin with a ‘.’ (hidden files) when performing filename completion. If set to ‘off’, the leading ‘.’ must be supplied by the user in the filename to be completed. This variable is ‘on’ by default. d46737 2 a46738 2 ‘menu-complete-display-prefix’ If set to ‘on’, menu completion displays the common prefix of d46740 1 a46740 1 cycling through the list. The default is ‘off’. d46742 2 a46743 2 ‘output-meta’ If set to ‘on’, Readline will display characters with the d46745 2 a46746 2 sequence. The default is ‘off’, but Readline will set it to ‘on’ if the locale contains eight-bit characters. d46748 4 a46751 4 ‘page-completions’ If set to ‘on’, Readline uses an internal ‘more’-like pager to display a screenful of possible completions at a time. This variable is ‘on’ by default. d46753 2 a46754 2 ‘print-completions-horizontally’ If set to ‘on’, Readline will display completions with matches d46756 1 a46756 1 the screen. The default is ‘off’. d46758 3 a46760 3 ‘revert-all-at-newline’ If set to ‘on’, Readline will undo all changes to history lines before returning when ‘accept-line’ is executed. By d46762 1 a46762 1 undo lists across calls to ‘readline’. The default is ‘off’. d46764 1 a46764 1 ‘show-all-if-ambiguous’ d46766 1 a46766 1 If set to ‘on’, words which have more than one possible d46768 1 a46768 1 of ringing the bell. The default value is ‘off’. d46770 1 a46770 1 ‘show-all-if-unmodified’ d46773 1 a46773 1 ‘on’, words which have more than one possible completion d46777 1 a46777 1 default value is ‘off’. d46779 2 a46780 2 ‘show-mode-in-prompt’ If set to ‘on’, add a string to the beginning of the prompt d46783 1 a46783 1 EMACS-MODE-STRING). The default value is ‘off’. d46785 16 a46800 16 ‘skip-completed-text’ If set to ‘on’, this alters the default completion behavior when inserting a single match into the line. It's only active when performing completion in the middle of a word. If enabled, readline does not insert characters from the completion that match characters after point in the word being completed, so portions of the word following the cursor are not duplicated. For instance, if this is enabled, attempting completion when the cursor is after the ‘e’ in ‘Makefile’ will result in ‘Makefile’ rather than ‘Makefilefile’, assuming there is a single possible completion. The default value is ‘off’. ‘vi-cmd-mode-string’ If the SHOW-MODE-IN-PROMPT variable is enabled, this string is displayed immediately before the last line of the primary d46804 1 a46804 1 is available. Use the ‘\1’ and ‘\2’ escapes to begin and end d46807 1 a46807 1 default is ‘(cmd)’. d46809 3 a46811 3 ‘vi-ins-mode-string’ If the SHOW-MODE-IN-PROMPT variable is enabled, this string is displayed immediately before the last line of the primary d46815 1 a46815 1 is available. Use the ‘\1’ and ‘\2’ escapes to begin and end d46818 6 a46823 1 default is ‘(ins)’. a46824 4 ‘visible-stats’ If set to ‘on’, a character denoting a file's type is appended to the filename when listing possible completions. The default is ‘off’. d46827 5 a46831 5 The syntax for controlling key bindings in the init file is simple. First you need to find the name of the command that you want to change. The following sections contain tables of the command name, the default keybinding, if any, and a short description of what the command does. d46840 2 a46841 2 In addition to command names, readline allows keys to be bound to a string that is inserted when the key is pressed (a MACRO). d46843 1 a46843 1 KEYNAME: FUNCTION-NAME or MACRO d46850 3 a46852 3 In the example above, ‘C-u’ is bound to the function ‘universal-argument’, ‘M-DEL’ is bound to the function ‘backward-kill-word’, and ‘C-o’ is bound to run the macro d46854 1 a46854 1 ‘> output’ into the line). d46860 1 a46860 1 "KEYSEQ": FUNCTION-NAME or MACRO d46871 6 a46876 5 In the above example, ‘C-u’ is again bound to the function ‘universal-argument’ (just as it was in the first example), ‘‘C-x’ ‘C-r’’ is bound to the function ‘re-read-init-file’, and ‘ <[> <1> <1> <~>’ is bound to insert the text ‘Function Key 1’. d46881 1 a46881 1 ‘\C-’ d46883 2 a46884 1 ‘\M-’ d46886 2 a46887 1 ‘\e’ d46889 2 a46890 1 ‘\\’ d46892 2 a46893 1 ‘\"’ d46895 2 a46896 1 ‘\'’ d46902 1 a46902 1 ‘\a’ d46904 2 a46905 1 ‘\b’ d46907 2 a46908 1 ‘\d’ d46910 2 a46911 1 ‘\f’ d46913 2 a46914 1 ‘\n’ d46916 2 a46917 1 ‘\r’ d46919 2 a46920 1 ‘\t’ d46922 2 a46923 1 ‘\v’ d46925 2 a46926 1 ‘\NNN’ d46929 2 a46930 1 ‘\xHH’ d46938 2 a46939 2 character in the macro text, including ‘"’ and ‘'’. For example, the following binding will make ‘‘C-x’ \’ insert a single ‘\’ into d46943 1 d46951 18 a46968 17 compilation features of the C preprocessor which allows key bindings and variable settings to be performed as the result of tests. There are four parser directives used. ‘$if’ The ‘$if’ construct allows bindings to be made based on the editing mode, the terminal being used, or the application using Readline. The text of the test, after any comparison operator, extends to the end of the line; unless otherwise noted, no characters are required to isolate it. ‘mode’ The ‘mode=’ form of the ‘$if’ directive is used to test whether Readline is in ‘emacs’ or ‘vi’ mode. This may be used in conjunction with the ‘set keymap’ command, for instance, to set bindings in the ‘emacs-standard’ and ‘emacs-ctlx’ keymaps only if Readline is starting out in ‘emacs’ mode. d46970 2 a46971 2 ‘term’ The ‘term=’ form may be used to include terminal-specific key d46974 7 a46980 7 ‘=’ is tested against both the full name of the terminal and the portion of the terminal name before the first ‘-’. This allows ‘sun’ to match both ‘sun’ and ‘sun-cmd’, for instance. ‘version’ The ‘version’ test may be used to perform comparisons against specific Readline versions. The ‘version’ expands to the d46982 1 a46982 1 includes ‘=’ (and ‘==’), ‘!=’, ‘<=’, ‘>=’, ‘<’, and ‘>’. The d46984 7 a46990 6 consists of a major version number, an optional decimal point, and an optional minor version (e.g., ‘7.1’). If the minor version is omitted, it is assumed to be ‘0’. The operator may be separated from the string ‘version’ and from the version number argument by whitespace. The following example sets a variable if the Readline version being used is 7.0 or newer: d46995 1 a46995 1 ‘application’ d47008 1 a47008 1 ‘variable’ d47011 1 a47011 1 operators are ‘=’, ‘==’, and ‘!=’. The variable name must be d47015 1 a47015 1 tested. Boolean variables must be tested against the values d47017 1 a47017 1 ‘mode=emacs’ test described above: d47022 2 a47023 2 ‘$endif’ This command, as seen in the previous example, terminates an ‘$if’ d47026 2 a47027 2 ‘$else’ Commands in this branch of the ‘$if’ directive are executed if the d47030 1 a47030 1 ‘$include’ d47033 1 a47033 1 directive reads from ‘/etc/inputrc’: d47045 1 d47163 1 a47163 1 This section describes Readline commands that may be bound to key d47167 4 a47170 4 In the following descriptions, “point” refers to the current cursor position, and “mark” refers to a cursor position saved by the ‘set-mark’ command. The text between the point and mark is referred to as the “region”. d47178 1 a47178 1 ‘beginning-of-line (C-a)’ d47181 1 a47181 1 ‘end-of-line (C-e)’ d47184 1 a47184 1 ‘forward-char (C-f)’ d47187 1 a47187 1 ‘backward-char (C-b)’ d47190 1 a47190 1 ‘forward-word (M-f)’ d47194 1 a47194 1 ‘backward-word (M-b)’ d47198 1 a47198 1 ‘previous-screen-line ()’ d47200 1 a47200 1 previous physical screen line. This will not have the desired d47205 1 a47205 1 ‘next-screen-line ()’ d47207 1 a47207 1 next physical screen line. This will not have the desired effect d47212 1 a47212 1 ‘clear-display (M-C-l)’ d47217 3 a47219 3 ‘clear-screen (C-l)’ Clear the screen, then redraw the current line, leaving the current line at the top of the screen. d47221 1 a47221 1 ‘redraw-current-line ()’ d47224 1 d47231 1 a47231 1 ‘accept-line (Newline or Return)’ d47234 2 a47235 2 with ‘add_history()’. If this line is a modified history line, the history line is restored to its original state. d47237 2 a47238 2 ‘previous-history (C-p)’ Move 'back' through the history list, fetching the previous d47241 2 a47242 2 ‘next-history (C-n)’ Move 'forward' through the history list, fetching the next command. d47244 1 a47244 1 ‘beginning-of-history (M-<)’ d47247 1 a47247 1 ‘end-of-history (M->)’ d47251 2 a47252 2 ‘reverse-search-history (C-r)’ Search backward starting at the current line and moving 'up' d47257 2 a47258 2 ‘forward-search-history (C-s)’ Search forward starting at the current line and moving 'down' d47263 4 a47266 4 ‘non-incremental-reverse-search-history (M-p)’ Search backward starting at the current line and moving 'up' through the history as necessary using a non-incremental search for a string supplied by the user. The search string may match d47269 4 a47272 4 ‘non-incremental-forward-search-history (M-n)’ Search forward starting at the current line and moving 'down' through the history as necessary using a non-incremental search for a string supplied by the user. The search string may match d47275 1 a47275 1 ‘history-search-forward ()’ d47281 1 a47281 1 ‘history-search-backward ()’ d47287 1 a47287 1 ‘history-substring-search-forward ()’ d47293 1 a47293 1 ‘history-substring-search-backward ()’ d47299 1 a47299 1 ‘yank-nth-arg (M-C-y)’ d47305 1 a47305 1 argument N is computed, the argument is extracted as if the ‘!N’ d47308 1 a47308 1 ‘yank-last-arg (M-. or M-_)’ d47311 17 a47327 15 like ‘yank-nth-arg’. Successive calls to ‘yank-last-arg’ move back through the history list, inserting the last word (or the word specified by the argument to the first call) of each line in turn. Any numeric argument supplied to these successive calls determines the direction to move through the history. A negative argument switches the direction through the history (back or forward). The history expansion facilities are used to extract the last argument, as if the ‘!$’ history expansion had been specified. ‘operate-and-get-next (C-o)’ Accept the current line for return to the calling application as if a newline had been entered, and fetch the next line relative to the current line from the history for editing. A numeric argument, if supplied, specifies the history entry to use instead of the current line. d47335 1 a47335 1 ‘end-of-file (usually C-d)’ d47337 1 a47337 1 ‘stty’. If this character is read when there are no characters on d47341 1 a47341 1 ‘delete-char (C-d)’ d47343 1 a47343 1 same character as the tty EOF character, as ‘C-d’ commonly is, see d47346 1 a47346 1 ‘backward-delete-char (Rubout)’ d47350 1 a47350 1 ‘forward-backward-delete-char ()’ d47355 1 a47355 1 ‘quoted-insert (C-q or C-v)’ d47357 1 a47357 1 insert key sequences like ‘C-q’, for example. d47359 1 a47359 1 ‘tab-insert (M-)’ d47362 1 a47362 1 ‘self-insert (a, b, A, 1, !, ...)’ d47365 1 a47365 1 ‘bracketed-paste-begin ()’ d47370 2 a47371 2 read from the keyboard. The characters are inserted as if each one was bound to ‘self-insert’ instead of executing any editing d47375 1 a47375 1 the mark) to the inserted text. It uses the concept of an _active d47379 1 a47379 1 ‘transpose-chars (C-t)’ d47385 1 a47385 1 ‘transpose-words (M-t)’ d47390 1 a47390 1 ‘upcase-word (M-u)’ d47394 1 a47394 1 ‘downcase-word (M-l)’ d47398 1 a47398 1 ‘capitalize-word (M-c)’ d47402 1 a47402 1 ‘overwrite-mode ()’ d47406 2 a47407 2 ‘emacs’ mode; ‘vi’ mode does overwrite differently. Each call to ‘readline()’ starts in insert mode. d47409 1 a47409 1 In overwrite mode, characters bound to ‘self-insert’ replace the d47411 1 a47411 1 Characters bound to ‘backward-delete-char’ replace the character d47416 1 d47423 1 a47423 1 ‘kill-line (C-k)’ d47425 2 a47426 2 numeric argument, kill backward from the cursor to the beginning of the current line. d47428 1 a47428 1 ‘backward-kill-line (C-x Rubout)’ d47433 1 a47433 1 ‘unix-line-discard (C-u)’ d47436 1 a47436 1 ‘kill-whole-line ()’ d47440 1 a47440 1 ‘kill-word (M-d)’ d47443 1 a47443 1 as ‘forward-word’. d47445 1 a47445 1 ‘backward-kill-word (M-)’ d47447 1 a47447 1 ‘backward-word’. d47449 1 a47449 1 ‘shell-transpose-words (M-C-t)’ d47453 2 a47454 2 boundaries are the same as ‘shell-forward-word’ and ‘shell-backward-word’. d47456 1 a47456 1 ‘unix-word-rubout (C-w)’ d47460 1 a47460 1 ‘unix-filename-rubout ()’ d47465 1 a47465 1 ‘delete-horizontal-space ()’ d47469 1 a47469 1 ‘kill-region ()’ d47473 1 a47473 1 ‘copy-region-as-kill ()’ d47477 4 a47480 4 ‘copy-backward-word ()’ Copy the word before point to the kill buffer. The word boundaries are the same as ‘backward-word’. By default, this command is unbound. d47482 1 a47482 1 ‘copy-forward-word ()’ d47484 1 a47484 1 boundaries are the same as ‘forward-word’. By default, this d47487 1 a47487 1 ‘yank (C-y)’ d47490 1 a47490 1 ‘yank-pop (M-y)’ d47492 1 a47492 1 if the prior command is ‘yank’ or ‘yank-pop’. d47500 1 a47500 1 ‘digit-argument (M-0, M-1, ... M--)’ d47502 1 a47502 1 argument. ‘M--’ starts a negative argument. d47504 1 a47504 1 ‘universal-argument ()’ d47507 9 a47515 9 sign, those digits define the argument. If the command is followed by digits, executing ‘universal-argument’ again ends the numeric argument, but is otherwise ignored. As a special case, if this command is immediately followed by a character that is neither a digit nor minus sign, the argument count for the next command is multiplied by four. The argument count is initially one, so executing this function the first time makes the argument count four, a second time makes the argument count sixteen, and so on. By default, this is not bound to a key. d47523 4 a47526 4 ‘complete ()’ Attempt to perform completion on the text before point. The actual completion performed is application-specific. The default is filename completion. d47528 1 a47528 1 ‘possible-completions (M-?)’ d47531 3 a47533 3 for display to the value of ‘completion-display-width’, the value of the environment variable ‘COLUMNS’, or the screen width, in that order. d47535 1 a47535 1 ‘insert-completions (M-*)’ d47537 1 a47537 1 been generated by ‘possible-completions’. d47539 4 a47542 4 ‘menu-complete ()’ Similar to ‘complete’, but replaces the word to be completed with a single match from the list of possible completions. Repeated execution of ‘menu-complete’ steps through the list of possible d47545 1 a47545 1 ‘bell-style’) and the original text is restored. An argument of N d47551 3 a47553 3 ‘menu-complete-backward ()’ Identical to ‘menu-complete’, but moves backward through the list of possible completions, as if ‘menu-complete’ had been given a d47556 1 a47556 1 ‘delete-char-or-list ()’ d47558 2 a47559 2 end of the line (like ‘delete-char’). If at the end of the line, behaves identically to ‘possible-completions’. This command is d47562 1 d47569 1 a47569 1 ‘start-kbd-macro (C-x ()’ d47572 1 a47572 1 ‘end-kbd-macro (C-x ))’ d47576 1 a47576 1 ‘call-last-kbd-macro (C-x e)’ d47580 1 a47580 1 ‘print-last-kbd-macro ()’ d47584 1 d47591 1 a47591 1 ‘re-read-init-file (C-x C-r)’ d47595 1 a47595 1 ‘abort (C-g)’ d47597 1 a47597 1 (subject to the setting of ‘bell-style’). d47599 1 a47599 1 ‘do-lowercase-version (M-A, M-B, M-X, ...)’ d47604 1 a47604 1 ‘prefix-meta ()’ d47606 1 a47606 1 meta key. Typing ‘ f’ is equivalent to typing ‘M-f’. d47608 1 a47608 1 ‘undo (C-_ or C-x C-u)’ d47611 1 a47611 1 ‘revert-line (M-r)’ d47613 1 a47613 1 ‘undo’ command enough times to get back to the beginning. d47615 1 a47615 1 ‘tilde-expand (M-~)’ d47618 1 a47618 1 ‘set-mark (C-@@)’ d47622 1 a47622 1 ‘exchange-point-and-mark (C-x C-x)’ d47627 1 a47627 1 ‘character-search (C-])’ d47632 1 a47632 1 ‘character-search-backward (M-C-])’ d47637 1 a47637 1 ‘skip-csi-sequence ()’ d47641 4 a47644 4 sequence is bound to "\e[", keys producing such sequences will have no effect unless explicitly bound to a readline command, instead of inserting stray characters into the editing buffer. This is unbound by default, but usually bound to ESC-[. d47646 2 a47647 2 ‘insert-comment (M-#)’ Without a numeric argument, the value of the ‘comment-begin’ d47649 6 a47654 5 numeric argument is supplied, this command acts as a toggle: if the characters at the beginning of the line do not match the value of ‘comment-begin’, the value is inserted, otherwise the characters in ‘comment-begin’ are deleted from the beginning of the line. In either case, the line is accepted as if a newline had been typed. d47656 1 a47656 1 ‘dump-functions ()’ d47662 1 a47662 1 ‘dump-variables ()’ d47668 1 a47668 1 ‘dump-macros ()’ d47670 3 a47672 3 strings they output. If a numeric argument is supplied, the output is formatted in such a way that it can be made part of an INPUTRC file. This command is unbound by default. d47674 2 a47675 2 ‘emacs-editing-mode (C-e)’ When in ‘vi’ command mode, this causes a switch to ‘emacs’ editing d47678 2 a47679 2 ‘vi-editing-mode (M-C-j)’ When in ‘emacs’ editing mode, this causes a switch to ‘vi’ editing d47682 1 d47689 1 a47689 1 While the Readline library does not have a full set of ‘vi’ editing d47691 1 a47691 1 The Readline ‘vi’ mode behaves as specified in the POSIX standard. d47693 10 a47702 10 In order to switch interactively between ‘emacs’ and ‘vi’ editing modes, use the command ‘M-C-j’ (bound to emacs-editing-mode when in ‘vi’ mode and to vi-editing-mode in ‘emacs’ mode). The Readline default is ‘emacs’ mode. When you enter a line in ‘vi’ mode, you are already placed in 'insertion' mode, as if you had typed an ‘i’. Pressing switches you into 'command' mode, where you can edit the text of the line with the standard ‘vi’ movement keys, move to previous history lines with ‘k’ and subsequent lines with ‘j’, and so forth. d47712 3 a47714 2 information on using the GNU History Library in your own programs, *note (history)Programming with GNU History::. d47727 1 a47727 1 to the history expansion provided by ‘csh’. This section describes the d47731 2 a47732 2 input stream, making it easy to repeat commands, insert the arguments to a previous command into the current input line, or fix errors in d47739 6 a47744 6 called the “event”, and the portions of that line that are acted upon are called “words”. Various “modifiers” are available to manipulate the selected words. The line is broken into words in the same fashion that Bash does, so that several words surrounded by quotes are considered one word. History expansions are introduced by the appearance of the history expansion character, which is ‘!’ by default. d47749 4 a47752 4 can be used to inhibit history expansion; and characters enclosed within double quotes may be subject to history expansion, since backslash can escape the history expansion character, but single quotes may not, since they are not treated specially within double quotes. d47768 1 a47768 1 the current position in the history list. d47770 1 a47770 1 ‘!’ d47772 1 a47772 1 the end of the line, or ‘=’. d47774 1 a47774 1 ‘!N’ d47777 1 a47777 1 ‘!-N’ d47780 2 a47781 2 ‘!!’ Refer to the previous command. This is a synonym for ‘!-1’. d47783 1 a47783 1 ‘!STRING’ d47787 1 a47787 1 ‘!?STRING[?]’ d47789 1 a47789 1 the history list containing STRING. The trailing ‘?’ may be d47794 1 a47794 1 ‘^STRING1^STRING2^’ d47796 1 a47796 1 with STRING2. Equivalent to ‘!!:s^STRING1^STRING2^’. d47798 1 a47798 1 ‘!#’ d47801 1 d47808 6 a47813 6 Word designators are used to select desired words from the event. A ‘:’ separates the event specification from the word designator. It may be omitted if the word designator begins with a ‘^’, ‘$’, ‘*’, ‘-’, or ‘%’. Words are numbered from the beginning of the line, with the first word being denoted by 0 (zero). Words are inserted into the current line separated by single spaces. d47817 1 a47817 1 ‘!!’ d47821 1 a47821 1 ‘!!:$’ d47823 1 a47823 1 shortened to ‘!$’. d47825 1 a47825 1 ‘!fi:2’ d47827 1 a47827 1 with the letters ‘fi’. d47831 2 a47832 2 ‘0 (zero)’ The ‘0’th word. For many applications, this is the command word. d47834 1 a47834 1 ‘N’ d47837 1 a47837 1 ‘^’ d47840 1 a47840 1 ‘$’ d47843 10 a47852 10 ‘%’ The first word matched by the most recent ‘?STRING?’ search, if the search string begins with a character that is part of a word. ‘X-Y’ A range of words; ‘-Y’ abbreviates ‘0-Y’. ‘*’ All of the words, except the ‘0’th. This is a synonym for ‘1-$’. It is not an error to use ‘*’ if there is just one word in the d47855 2 a47856 2 ‘X*’ Abbreviates ‘X-$’ d47858 2 a47859 2 ‘X-’ Abbreviates ‘X-$’ like ‘X*’, but omits the last word. If ‘x’ is d47862 1 d47873 1 a47873 1 more of the following modifiers, each preceded by a ‘:’. These modify, d47876 1 a47876 1 ‘h’ d47879 1 a47879 1 ‘t’ d47882 2 a47883 2 ‘r’ Remove a trailing suffix of the form ‘.SUFFIX’, leaving the d47886 1 a47886 1 ‘e’ d47889 1 a47889 1 ‘p’ d47892 1 a47892 1 ‘s/OLD/NEW/’ d47894 4 a47897 4 Any character may be used as the delimiter in place of ‘/’. The delimiter may be quoted in OLD and NEW with a single backslash. If ‘&’ appears in NEW, it is replaced by OLD. A single backslash will quote the ‘&’. If OLD is null, it is set to the last OLD d47899 3 a47901 3 the last STRING in a !?STRING‘[?]’ search. If NEW is is null, each matching OLD is deleted. The final delimiter is optional if it is the last character on the input line. d47903 1 a47903 1 ‘&’ d47906 2 a47907 2 ‘g’ ‘a’ d47909 1 a47909 1 conjunction with ‘s’, as in ‘gs/OLD/NEW/’, or with ‘&’. d47911 2 a47912 2 ‘G’ Apply the following ‘s’ or ‘&’ modifier once to each word in the d47915 1 d47924 1 a47924 1 ‘Fred Fish’ d47930 1 a47930 1 ‘Michael Snyder’ d47946 1 a47946 1 for printing with PostScript or Ghostscript, in the ‘gdb’ subdirectory d47949 1 a47949 1 immediately with ‘refcard.ps’. d47951 2 a47952 2 The release also includes the source for the reference card. You can format it, using TeX, by typing: d47956 2 a47957 2 The GDB reference card is designed to print in “landscape” mode on US "letter" size paper; that is, on a sheet 11 inches wide by 8.5 inches d47966 1 a47966 1 and TeX (or ‘texi2roff’) to typeset the printed version. d47968 4 a47971 4 GDB includes an already formatted copy of the on-line Info version of this manual in the ‘gdb’ subdirectory. The main Info file is ‘gdb-15.1/gdb/gdb.info’, and it refers to subordinate files matching ‘gdb.info*’ in the same directory. If necessary, you can print out d47973 1 a47973 1 using the ‘info’ subsystem in GNU Emacs or the standalone ‘info’ d47977 1 a47977 1 Info formatting programs, such as ‘texinfo-format-buffer’ or ‘makeinfo’. d47979 3 a47981 3 If you have ‘makeinfo’ installed, and are in the top level GDB source directory (‘gdb-15.1’, in the case of version 15.1), you can make the Info file by typing: d47987 1 a47987 1 a program to print its DVI output files, and ‘texinfo.tex’, the Texinfo d47994 9 a48002 9 use depends on your system; ‘lpr -d’ is common; another (for PostScript devices) is ‘dvips’. The DVI print command may require a file name without any extension or a ‘.dvi’ extension. TeX also requires a macro definitions file called ‘texinfo.tex’. This file tells TeX how to typeset a document written in Texinfo format. On its own, TeX cannot either read or typeset a Texinfo file. ‘texinfo.tex’ is distributed with GDB and is located in the ‘gdb-VERSION-NUMBER/texinfo’ directory. d48005 2 a48006 2 and print this manual. First switch to the ‘gdb’ subdirectory of the main source directory (for example, to ‘gdb-15.1/gdb’) and type: d48010 1 a48010 1 Then give ‘gdb.dvi’ to your DVI printing program. d48014 1 a48014 1 (1) In ‘gdb-15.1/gdb/refcard.ps’ of the version 15.1 release. d48025 1 a48025 1 * Running Configure:: Invoking the GDB ‘configure’ script d48037 2 a48038 2 Building GDB requires various tools and packages to be available. Other packages will be used only if they are found. d48049 1 a48049 1 program. Other variants of ‘make’ will not work. d48053 1 a48053 1 ‘configure’ script searches for each of these libraries in several d48055 1 a48055 1 place, you can use either the ‘--with-LIB’ ‘configure’ option to d48057 2 a48058 2 ‘---with-LIBRARY-include’ (to specify the location of its header files) and ‘--with-LIBRARY-lib’ (to specify the location of its d48060 1 a48060 1 ‘--with-gmp’, ‘--with-gmp-include’, and ‘--with-gmp-lib’. *Note d48062 2 a48063 2 library, so that you could download and install them if your system doesn't already include them. d48065 1 a48065 1 GMP (The GNU Multiple Precision arithmetic library) d48068 1 a48068 1 . d48070 1 a48070 1 MPFR (The GNU Multiple-precision floating-point library) d48074 2 a48075 1 MPFR is available from . d48084 6 a48089 6 ‘configure’ script to specify their installation directories if they are non-standard. In addition, for each package you can use the option ‘--with-PACKAGE’ to force GDB to be compiled with the named PACKAGE, and ‘--without-PACKAGE’ to disable building with it even if it is available. *Note Configure Options::, for detailed description of the options to ‘configure’. d48094 1 a48094 1 . Use the ‘--with-python=DIR’ d48100 1 a48100 1 . If you have more d48102 1 a48102 1 ‘--with-guile=GUILE-VERSION’ to specify the Guile version to d48109 5 a48113 3 • Remote protocol memory maps (*note Memory Map Format::) • Target descriptions (*note Target Descriptions::) • Remote shared library lists (*Note Library List Format::, or d48115 6 a48120 3 • MS-Windows shared libraries (*note Shared Libraries::) • Traceframe info (*note Traceframe Info Format::) • Branch trace (*note Branch Trace Format::, *note Branch Trace d48124 1 a48124 1 . Use the ‘--with-libexpat-prefix’ d48129 1 a48129 1 require a functioning ‘iconv’ implementation. If you are on a GNU d48131 2 a48132 2 systems also provide a working ‘iconv’. Use the option ‘--with-iconv-bin’ to specify where to find the ‘iconv’ program. d48134 1 a48134 1 On systems without ‘iconv’, you can install the GNU Libiconv d48136 3 a48138 3 if your system doesn't provide it. Use the ‘--with-libiconv-prefix’ option to ‘configure’ to specify non-standard installation place for it. d48140 2 a48141 2 Alternatively, GDB's top-level ‘configure’ and ‘Makefile’ will arrange to build Libiconv if a directory named ‘libiconv’ appears d48143 1 a48143 1 and if the operating system does not provide a suitable ‘iconv’ d48148 1 a48148 1 source code to ‘libiconv’. d48154 2 a48155 2 package at . Use the ‘--with-liblzma-prefix’ option to specify its non-standard d48159 2 a48160 2 GDB will use the ‘zlib’ library, if available, to read compressed debug sections. Some linkers, such as GNU ‘gold’, are capable of d48162 2 a48163 2 compiled with ‘zlib’, it will be able to read the debug information in such binaries. d48165 1 a48165 1 The ‘zlib’ library is likely included with your operating system d48167 2 a48168 1 . d48173 1 a48173 1 C.2 Invoking the GDB ‘configure’ Script d48176 7 a48182 7 GDB comes with a ‘configure’ script that automates the process of preparing GDB for installation; you can then use ‘make’ to build the ‘gdb’ program. The GDB distribution includes all the source code you need for GDB in a single directory, whose name is usually composed by appending the version number to ‘gdb’. d48184 1 a48184 1 For example, the GDB version 15.1 distribution is in the ‘gdb-15.1’ d48187 1 a48187 1 ‘gdb-15.1/configure (and supporting files)’ d48190 1 a48190 1 ‘gdb-15.1/gdb’ d48193 1 a48193 1 ‘gdb-15.1/bfd’ d48196 1 a48196 1 ‘gdb-15.1/include’ d48199 2 a48200 2 ‘gdb-15.1/libiberty’ source for the ‘-liberty’ free software library d48202 1 a48202 1 ‘gdb-15.1/opcodes’ d48205 1 a48205 1 ‘gdb-15.1/readline’ d48210 3 a48212 3 The simplest way to configure and build GDB is to run ‘configure’ from the ‘gdb-VERSION-NUMBER’ source directory, which in this example is the ‘gdb-15.1’ directory. d48214 2 a48215 2 First switch to the ‘gdb-VERSION-NUMBER’ source directory if you are not already in it; then run ‘configure’. Pass the identifier for the d48224 2 a48225 2 Running ‘configure’ and then running ‘make’ builds the included supporting libraries, then ‘gdb’ itself. The configured source files, d48228 3 a48230 3 ‘configure’ is a Bourne-shell (‘/bin/sh’) script; if your system does not recognize this automatically when you run a different shell, you may need to run ‘sh’ on it explicitly: d48234 7 a48240 7 You should run the ‘configure’ script from the top directory in the source tree, the ‘gdb-VERSION-NUMBER’ directory. If you run ‘configure’ from one of the subdirectories, you will configure only that subdirectory. That is usually not what you want. In particular, if you run the first ‘configure’ from the ‘gdb’ subdirectory of the ‘gdb-VERSION-NUMBER’ directory, you will omit the configuration of ‘bfd’, ‘readline’, and other sibling directories of the ‘gdb’ d48242 1 a48242 1 such as ‘bfd/bfd.h’. d48244 3 a48246 3 You can install ‘GDB’ anywhere. The best way to do this is to pass the ‘--prefix’ option to ‘configure’, and then install it with ‘make install’. d48254 14 a48267 13 If you want to run GDB versions for several host or target machines, you need a different ‘gdb’ compiled for each combination of host and target. ‘configure’ is designed to make this easy by allowing you to generate each configuration in a separate subdirectory, rather than in the source directory. If your ‘make’ program handles the ‘VPATH’ feature (GNU ‘make’ does), running ‘make’ in each of these directories builds the ‘gdb’ program specified there. To build ‘gdb’ in a separate directory, run ‘configure’ with the ‘--srcdir’ option to specify where to find the source. (You also need to specify a path to find ‘configure’ itself from your working directory. If the path to ‘configure’ would be the same as the argument to ‘--srcdir’, you can leave out the ‘--srcdir’ option; it is assumed.) d48278 1 a48278 1 When ‘configure’ builds a configuration using a remote source d48281 2 a48282 2 the example, you'd find the Sun 4 library ‘libiberty.a’ in the directory ‘gdb-sun4/libiberty’, and GDB itself in ‘gdb-sun4/gdb’. d48284 5 a48288 5 Make sure that your path to the ‘configure’ script has just one instance of ‘gdb’ in it. If your path to ‘configure’ looks like ‘../gdb-15.1/gdb/configure’, you are configuring only one subdirectory of GDB, not the whole package. This leads to build errors about missing include files such as ‘bfd/bfd.h’. d48292 13 a48304 13 one machine--the “host”--while debugging programs that run on another machine--the “target”). You specify a cross-debugging target by giving the ‘--target=TARGET’ option to ‘configure’. When you run ‘make’ to build a program or library, you must run it in a configured directory--whatever directory you were in when you called ‘configure’ (or one of its subdirectories). The ‘Makefile’ that ‘configure’ generates in each source directory also runs recursively. If you type ‘make’ in a source directory such as ‘gdb-15.1’ (or in a separate configured directory configured with ‘--srcdir=DIRNAME/gdb-15.1’), you will build all the required libraries, and then build GDB. d48307 3 a48309 3 directories, you can run ‘make’ on them in parallel (for example, if they are NFS-mounted on each of the hosts); they will not interfere with each other. d48317 1 a48317 1 The specifications used for hosts and targets in the ‘configure’ script d48324 3 a48326 3 For example, you can use the alias ‘sun4’ as a HOST argument, or as the value for TARGET in a ‘--target=TARGET’ option. The equivalent full name is ‘sparc-sun-sunos4’. d48328 1 a48328 1 The ‘configure’ script accompanying GDB does not provide any query d48330 1 a48330 1 ‘configure’ calls the Bourne shell script ‘config.sub’ to map d48347 2 a48348 2 ‘config.sub’ is also distributed in the GDB source directory (‘gdb-15.1’, for version 15.1). d48353 1 a48353 1 C.5 ‘configure’ Options d48356 5 a48360 4 Here is a summary of the ‘configure’ options and arguments that are most often useful for building GDB. ‘configure’ also has several other options not listed here. *Note (autoconf)Running configure Scripts::, for a full explanation of ‘configure’. d48368 2 a48369 2 You may introduce options with a single ‘-’ rather than ‘--’ if you prefer; but you may abbreviate option names if you use ‘--’. d48371 2 a48372 2 ‘--help’ Display a quick summary of how to invoke ‘configure’. d48374 1 a48374 1 ‘--prefix=DIR’ d48376 1 a48376 1 ‘DIR’. d48378 2 a48379 2 ‘--exec-prefix=DIR’ Configure the source to install programs under directory ‘DIR’. d48381 9 a48389 9 ‘--srcdir=DIRNAME’ Use this option to make configurations in directories separate from the GDB source directories. Among other things, you can use this to build (or maintain) several configurations simultaneously, in separate directories. ‘configure’ writes configuration-specific files in the current directory, but arranges for them to use the source in the directory DIRNAME. ‘configure’ creates directories under the working directory in parallel to the source directories below DIRNAME. d48391 1 a48391 1 ‘--target=TARGET’ d48397 1 a48397 1 targets. Also see the ‘--enable-targets’ option, below. d48403 5 a48407 5 ‘--enable-targets=[TARGET]...’ ‘--enable-targets=all’ Configure GDB for cross-debugging programs running on the specified list of targets. The special value ‘all’ configures GDB for debugging programs running on any target it supports. d48409 1 a48409 1 ‘--with-gdb-datadir=PATH’ d48411 2 a48412 2 certain supporting files or scripts. This defaults to the ‘gdb’ subdirectory of ‘datadir’ (which can be set using ‘--datadir’). d48414 1 a48414 1 ‘--with-relocated-sources=DIR’ d48417 4 a48420 4 for any directory under DIR. DIR should be a subdirectory of GDB's configured prefix, the one mentioned in the ‘--prefix’ or ‘--exec-prefix’ options to configure. This option is useful if GDB is supposed to be moved to a different place after it is built. d48422 1 a48422 1 ‘--enable-64-bit-bfd’ d48425 1 a48425 1 ‘--disable-gdbmi’ d48428 1 a48428 1 ‘--enable-tui’ d48432 1 a48432 1 ‘--with-curses’ d48436 2 a48437 2 ‘--with-debuginfod’ Build GDB with ‘libdebuginfod’, the ‘debuginfod’ client library. d48439 2 a48440 2 ‘debuginfod’ servers using build IDs associated with any missing files. Enabled by default if ‘libdebuginfod’ is installed and d48442 1 a48442 1 ‘debuginfod’ see *note Debuginfod::. d48444 1 a48444 1 ‘--with-libunwind-ia64’ d48446 2 a48447 2 target platforms. See for details. d48449 1 a48449 1 ‘--with-system-readline’ d48454 1 a48454 1 ‘--with-system-zlib’ d48458 1 a48458 1 ‘--with-expat’ d48466 1 a48466 1 . d48468 1 a48468 1 ‘--with-libiconv-prefix[=DIR]’ d48471 3 a48473 3 ‘iconv’ that is built in to the C library is sufficient. If your host does not have a working ‘iconv’, you can get the latest version of GNU iconv from . d48476 1 a48476 1 the overall build. *Note Requirements::. d48478 1 a48478 1 ‘--with-lzma’ d48484 1 a48484 1 . d48486 1 a48486 1 ‘--with-python[=PYTHON]’ d48491 1 a48491 1 find it on . The oldest version d48497 1 a48497 1 ‘--with-guile[=GUILE]’ d48501 3 a48503 3 . The optional argument GUILE can be a version number, which will cause ‘configure’ to try to use that version of Guile; or the file name of a ‘pkg-config’ d48507 1 a48507 1 ‘--without-included-regex’ d48512 1 a48512 1 ‘--with-sysroot=DIR’ d48514 4 a48517 4 file names begin with ‘/lib’' or ‘/usr/lib'’. (The value of DIR can be modified at run time by using the ‘set sysroot’ command.) If DIR is under the GDB configured prefix (set with ‘--prefix’ or ‘--exec-prefix options’, the default system root will be d48521 1 a48521 1 ‘--with-system-gdbinit=FILE’ d48528 1 a48528 1 ‘--with-system-gdbinit-dir=DIRECTORY’ d48531 3 a48533 3 DIRECTORY is in a directory under the configured prefix, and GDB is moved to another location after being built, the location of the system-wide init directory will be adjusted accordingly. d48535 1 a48535 1 ‘--enable-build-warnings’ d48537 3 a48539 3 code which looks even vaguely suspicious. It passes many different warning flags, depending on the exact version of the compiler you are using. d48541 2 a48542 2 ‘--enable-werror’ Treat compiler warnings as errors. It adds the ‘-Werror’ flag to d48546 1 a48546 1 ‘--enable-ubsan’ d48548 2 a48549 2 default, but passing ‘--enable-ubsan=yes’ or ‘--enable-ubsan=auto’ to ‘configure’ will enable it. The undefined behavior sanitizer d48561 3 a48563 3 init file directory; this file and files in that directory (if they have a recognized file extension) will be read and executed at startup (*note What GDB does during startup: Startup.). d48567 1 a48567 1 ‘--with-system-gdbinit=FILE’ d48570 2 a48571 1 ‘--with-system-gdbinit-dir=DIRECTORY’ d48575 1 a48575 1 If GDB has been configured with the option ‘--prefix=$prefix’, they d48578 6 a48583 6 • If the default location of this init file/directory contains ‘$prefix’, it will be subject to relocation. Suppose that the configure options are ‘--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit’; if GDB is moved from ‘$prefix’ to ‘$install’, the system init file is looked for as ‘$install/etc/gdbinit’ instead of ‘$prefix/etc/gdbinit’. d48585 1 a48585 1 • By contrast, if the default location does not contain the prefix, d48587 2 a48588 2 ‘--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit’, then GDB will always look for ‘/usr/share/gdb/gdbinit’, wherever d48592 2 a48593 2 the ‘--with-system-gdbinit’ option at configure time) is in the data-directory (as specified by ‘--with-gdb-datadir’ at configure time) d48595 1 a48595 1 init file in the directory specified by the ‘--data-directory’ d48597 3 a48599 3 once, during GDB initialization. If the data-directory is changed after GDB has started with the ‘set data-directory’ command, the file will not be reread. d48602 1 a48602 1 ‘--with-system-gdbinit-dir’. d48604 3 a48606 3 Any supported scripting language can be used for these init files, as long as the file extension matches the scripting language. To be interpreted as regular GDB commands, the files needs to have a ‘.gdb’ d48619 2 a48620 2 The ‘system-gdbinit’ directory, located inside the data-directory (as specified by ‘--with-gdb-datadir’ at configure time) contains a number d48623 1 a48623 1 with ‘--with-system-gdbinit’. Otherwise, any user should be able to d48627 1 a48627 2 • ‘elinos.py’ This script is useful when debugging a program on an d48631 1 a48631 1 ‘solib-absolute-prefix’ and ‘solib-search-path’ variables d48634 4 a48637 3 • ‘wrs-linux.py’ This script is useful when debugging a program on a target running Wind River Linux. It expects the ‘ENV_PREFIX’ to be set to the host-side sysroot used by the target system. d48645 5 a48649 4 In addition to commands intended for GDB users, GDB includes a number of commands intended for GDB developers, that are not documented elsewhere in this manual. These commands are provided here for reference. (For commands that turn on debugging messages, see *note Debugging Output::.) d48651 2 a48652 2 ‘maint agent [-at LINESPEC,] EXPRESSION’ ‘maint agent-eval [-at LINESPEC,] EXPRESSION’ d48655 1 a48655 1 (*note Agent Expressions::). The ‘agent’ version produces an d48657 1 a48657 1 while ‘maint agent-eval’ produces an expression that evaluates d48659 2 a48660 2 ‘globa + globb’ will include bytecodes to record four bytes of memory at each of the addresses of ‘globa’ and ‘globb’, while d48662 1 a48662 1 expression will do the addition and return the sum. If ‘-at’ is d48667 1 a48667 1 ‘maint agent-printf FORMAT,EXPR,...’ d48673 2 a48674 2 ‘maint info breakpoints’ Using the same format as ‘info breakpoints’, display both the d48680 1 a48680 1 ‘breakpoint’ d48683 1 a48683 1 ‘watchpoint’ d48686 1 a48686 1 ‘longjmp’ d48688 1 a48688 1 ‘longjmp’ calls. d48690 2 a48691 2 ‘longjmp resume’ Internal breakpoint at the target of a ‘longjmp’. d48693 2 a48694 2 ‘until’ Temporary internal breakpoint used by the GDB ‘until’ command. d48696 2 a48697 2 ‘finish’ Temporary internal breakpoint used by the GDB ‘finish’ d48700 1 a48700 1 ‘shlib events’ d48703 2 a48704 1 ‘maint info btrace’ d48707 1 a48707 1 ‘maint btrace packet-history’ d48709 1 a48709 1 execution history for the ‘record btrace’ command. Both the d48713 1 a48713 1 ‘bts’ d48715 2 a48716 2 sequential code. For each block, the following information is printed: d48718 1 a48718 1 Block number a48720 2 Lowest ‘PC’ Highest ‘PC’ d48722 5 a48726 1 ‘pt’ d48731 5 a48735 4 Packet number Newer packets have higher numbers. The oldest packet has number zero. Trace offset a48736 1 Packet opcode and payload d48738 5 a48742 3 ‘maint btrace clear-packet-history’ Discards the cached packet history printed by the ‘maint btrace packet-history’ command. The history will be computed again when d48745 1 a48745 1 ‘maint btrace clear’ d48753 1 a48753 4 ‘maint set btrace pt skip-pad’ ‘maint show btrace pt skip-pad’ Control whether GDB will skip PAD packets when computing the packet history. d48755 5 a48759 1 ‘maint info jit’ d48763 5 a48767 5 ‘maint info python-disassemblers’ This command is defined within the ‘gdb.disassembler’ Python module (*note Disassembly In Python::), and will only be present after that module has been imported. To force the module to be imported do the following: d48769 1 a48769 1 ‘maint info linux-lwps’ d48778 1 a48778 1 listed last against the ‘GLOBAL’ architecture. d48784 1 a48784 1 are registered, initially the ‘i386’ disassembler matches the d48786 1 a48786 1 ‘GLOBAL’ disassembler matches. d48802 3 a48804 3 ‘set displaced-stepping’ ‘show displaced-stepping’ Control whether or not GDB will do “displaced stepping” if the d48811 3 a48813 3 ‘set displaced-stepping on’ If the target architecture supports it, GDB will use displaced stepping to step over breakpoints. d48815 1 a48815 1 ‘set displaced-stepping off’ d48819 1 a48819 1 ‘set displaced-stepping auto’ d48824 1 a48824 1 ‘maint check-psymtabs’ d48829 1 a48829 1 ‘maint check-symtabs’ d48832 1 a48832 1 ‘maint expand-symtabs [REGEXP]’ d48836 2 a48837 2 ‘maint set catch-demangler-crashes [on|off]’ ‘maint show catch-demangler-crashes’ d48844 1 a48844 1 ‘maint cplus first_component NAME’ d48847 1 a48847 1 ‘maint cplus namespace’ d48850 2 a48851 2 ‘maint deprecate COMMAND [REPLACEMENT]’ ‘maint undeprecate COMMAND’ d48858 1 a48858 1 ‘maint dump-me’ d48861 1 a48861 5 with the ‘SIGQUIT’ signal. ‘maint internal-error [MESSAGE-TEXT]’ ‘maint internal-warning [MESSAGE-TEXT]’ ‘maint demangler-warning [MESSAGE-TEXT]’ d48863 5 a48867 2 Cause GDB to call the internal function ‘internal_error’, ‘internal_warning’ or ‘demangler_warning’ and hence behave as d48870 2 a48871 2 opportunity to either quit GDB or (for ‘internal_error’ and ‘internal_warning’) create a core file of the current GDB session. d48873 2 a48874 2 These commands take an optional parameter MESSAGE-TEXT that is used as the text of the error or warning message. d48876 1 a48876 1 Here's an example of using ‘internal-error’: d48886 3 a48888 3 ‘maint set debuginfod download-sections’ ‘maint set debuginfod download-sections [on|off]’ ‘maint show debuginfod download-sections’ d48890 1 a48890 1 sections from ‘debuginfod’. If disabled, only whole debug info d48894 6 a48899 6 ‘maint set internal-error ACTION [ask|yes|no]’ ‘maint show internal-error ACTION’ ‘maint set internal-warning ACTION [ask|yes|no]’ ‘maint show internal-warning ACTION’ ‘maint set demangler-warning ACTION [ask|yes|no]’ ‘maint show demangler-warning ACTION’ d48901 2 a48902 2 the user the opportunity to both quit GDB and create a core file of the current GDB session. These commands let you override the d48906 1 a48906 1 ‘quit’ d48910 1 a48910 1 ‘corefile’ d48913 2 a48914 2 do. Note that there is no ‘corefile’ option for ‘demangler-warning’: demangler warnings always create a core d48917 4 a48920 4 ‘maint set internal-error backtrace [on|off]’ ‘maint show internal-error backtrace’ ‘maint set internal-warning backtrace [on|off]’ ‘maint show internal-warning backtrace’ d48923 2 a48924 2 stream. This is ‘on’ by default for ‘internal-error’ and ‘off’ by default for ‘internal-warning’. d48926 5 a48930 5 ‘maint packet TEXT’ If GDB is talking to an inferior via the serial protocol, then this command sends the string TEXT to the inferior, and displays the response packet. GDB supplies the initial ‘$’ character, the terminating ‘#’ character, and the checksum. d48933 1 a48933 1 hex, e.g. ‘\x00’, ‘\x01’, etc. d48935 1 a48935 1 ‘maint print architecture [FILE]’ d48939 1 a48939 1 ‘maint print c-tdesc [-single-feature] [FILE]’ d48942 3 a48944 3 target, but if the optional argument FILE is provided, that file is used to produce the description. The FILE should be an XML document, of the form described in *note Target Description d48949 1 a48949 1 When the optional flag ‘-single-feature’ is provided then the d48951 2 a48952 2 FILE) must only contain a single feature. The source file produced is different in this case. d48954 1 a48954 1 ‘maint print xml-tdesc [FILE]’ d48959 1 a48959 1 The FILE should be an XML document, of the form described in *note d48962 3 a48964 3 ‘maint check xml-descriptions DIR’ Check that the target descriptions dynamically created by GDB equal the descriptions created from XML files found in DIR. d48966 1 a48966 1 ‘maint check libthread-db’ d48968 1 a48968 1 library. This exercises all ‘libthread_db’ functionality used by d48970 1 a48970 1 ‘proc_service’ functions provided by GDB that ‘libthread_db’ uses. d48974 1 a48974 1 ‘maint print core-file-backed-mappings’ d48977 1 a48977 1 similar to the mappings displayed by the ‘info proc mappings’ d48980 1 a48980 1 ‘maint print dummy-frames’ d48996 2 a48997 2 ‘maint print frame-id’ ‘maint print frame-id LEVEL’ d49002 1 a49002 1 ‘backtrace’ output. d49009 5 a49013 5 ‘maint print registers [FILE]’ ‘maint print raw-registers [FILE]’ ‘maint print cooked-registers [FILE]’ ‘maint print register-groups [FILE]’ ‘maint print remote-registers [FILE]’ d49016 2 a49017 2 The command ‘maint print raw-registers’ includes the contents of the raw register cache; the command ‘maint print cooked-registers’ d49020 4 a49023 4 command ‘maint print register-groups’ includes the groups that each register is a member of; and the command ‘maint print remote-registers’ includes the remote target's register numbers and offsets in the 'G' packets. d49028 1 a49028 1 ‘maint print reggroups [FILE]’ d49044 2 a49045 2 ‘maint flush register-cache’ ‘flushregs’ d49048 2 a49049 2 to register fetching, or frame unwinding. The command ‘flushregs’ is deprecated in favor of ‘maint flush register-cache’. d49051 1 a49051 1 ‘maint flush source-cache’ d49054 3 a49056 3 Styling::), the file contents are cached. This command clears that cache. The next time GDB wants to show lines from a source file, the content will be re-read. d49059 2 a49060 2 styling. After flushing the cache any source code displayed by GDB will be re-read and re-styled. d49062 1 a49062 1 ‘maint print objfiles [REGEXP]’ d49068 2 a49069 2 ‘maint print user-registers’ List all currently available “user registers”. User registers d49071 5 a49075 5 They include the four "standard" registers ‘$fp’, ‘$pc’, ‘$sp’, and ‘$ps’. *Note standard registers::. User registers can be used in expressions in the same way as the canonical register names, but only the latter are listed by the ‘info registers’ and ‘maint print registers’ commands. d49077 2 a49078 2 ‘maint print section-scripts [REGEXP]’ Print a dump of scripts specified in the ‘.debug_gdb_section’ d49080 3 a49082 3 object files matching REGEXP. For each script, this command prints its name as specified in the objfile, and the full path if known. *Note dotdebug_gdb_scripts section::. d49084 1 a49084 1 ‘maint print statistics’ d49086 1 a49086 1 data about that object file followed by the byte cache (“bcache”) d49090 12 a49101 12 tables, the number of line tables and string tables, and the amount of memory used by the various tables. The bcache statistics include the counts, sizes, and counts of duplicates of all and unique objects, max, average, and median entry size, total memory used and its overhead and savings, and various measures of the hash table size and chain lengths. ‘maint print target-stack’ A “target” is an interface between the debugger and a particular kind of file or process. Targets can be stacked in “strata”, so that more than one target can potentially respond to a request. In particular, memory accesses will walk down the stack of targets d49106 1 a49106 1 pushed on the “target stack”, starting from the top layer down to d49109 1 a49109 1 ‘maint print type EXPR’ d49111 2 a49112 2 can be either a type name or a symbol. If it is a symbol, the type of that symbol is described. The type chain produced by this d49116 2 a49117 2 ‘maint print record-instruction’ ‘maint print record-instruction N’ d49119 11 a49129 10 number, it prints the values stored by the inferior before the N-th previous instruction was executed. If N is positive, print the values after the N-th following instruction is executed. If N is not given, 0 is assumed. ‘maint selftest [-verbose] [FILTER]’ Run any self tests that were compiled in to GDB. This will print a message showing how many tests were run, and how many failed. If a FILTER is passed, only the tests with FILTER in their name will be ran. If ‘-verbose’ is passed, the self tests can be more verbose. d49131 3 a49133 2 ‘maint set selftest verbose’ ‘maint show selftest verbose’ d49136 1 a49136 1 ‘maint info selftests’ d49139 4 a49142 3 ‘maint set dwarf always-disassemble’ ‘maint show dwarf always-disassemble’ Control the behavior of ‘info address’ when using DWARF debugging d49145 5 a49149 5 The default is ‘off’, which means that GDB should try to describe a variable's location in an easily readable format. When ‘on’, GDB will instead display the DWARF location expression in an assembly-like format. Note that some locations are too complex for GDB to describe simply; in this case you will always see the d49161 2 a49162 2 ‘maint set dwarf max-cache-age’ ‘maint show dwarf max-cache-age’ d49166 1 a49166 1 those produced by the GCC option ‘-feliminate-dwarf2-dups’, the d49175 2 a49176 2 ‘maint set dwarf synchronous’ ‘maint show dwarf synchronous’ d49180 3 a49182 3 asynchronous with respect to the rest of GDB. That is, the bulk of the reading is done in the background, and GDB will only pause for completion of this task when absolutely necessary. d49192 2 a49193 2 ‘maint set dwarf unwinders’ ‘maint show dwarf unwinders’ d49198 3 a49200 3 have a second mechanism for building the backtrace for use in cases where DWARF information is not available, this second mechanism is often an analysis of a function's prologue. d49215 1 a49215 1 ‘maint info frame-unwinders’ d49219 3 a49221 2 ‘maint set worker-threads’ ‘maint show worker-threads’ d49227 1 a49227 1 ‘unlimited’, which lets GDB choose a reasonable number. Note that d49231 2 a49232 2 ‘maint set profile’ ‘maint show profile’ d49235 1 a49235 1 Profiling will be disabled until you use the ‘maint set profile’ d49240 3 a49242 3 profiling log file (often called ‘gmon.out’). If you have a record of important profiling data in a ‘gmon.out’ file, be sure to move it to a safe location. d49244 2 a49245 2 Configuring with ‘--enable-profiling’ arranges for GDB to be compiled with the ‘-pg’ compiler option. d49247 2 a49248 2 ‘maint set show-debug-regs’ ‘maint show show-debug-regs’ d49250 1 a49250 1 registers. Use ‘on’ to enable, ‘off’ to disable. If enabled, the d49252 2 a49253 2 hardware breakpoint or watchpoint, and when the inferior triggers a hardware-assisted breakpoint or watchpoint. d49255 2 a49256 2 ‘maint set show-all-tib’ ‘maint show show-all-tib’ d49258 2 a49259 2 starting at thread local base, when using the ‘info w32 thread-information-block’ command. d49261 2 a49262 2 ‘maint set target-async’ ‘maint show target-async’ d49266 2 a49267 5 changed to more easily debug problems occurring only in synchronous mode. ‘maint set target-non-stop’ ‘maint show target-non-stop’ d49269 2 d49272 7 a49278 3 even if ‘set non-stop’ is ‘off’ (*note Non-Stop Mode::). The default is ‘auto’, meaning non-stop mode is enabled if supported by the target. d49280 1 a49280 5 ‘maint set target-non-stop auto’ This is the default mode. GDB controls the target in non-stop mode if the target supports it. ‘maint set target-non-stop on’ d49284 1 a49284 1 ‘maint set target-non-stop off’ d49288 3 a49290 2 ‘maint set tui-resize-message’ ‘maint show tui-resize-message’ d49292 2 a49293 2 resized when in TUI mode. The default is ‘off’, which means that GDB is silent during resizes. When ‘on’, GDB will display a d49300 3 a49302 2 ‘maint set tui-left-margin-verbose’ ‘maint show tui-left-margin-verbose’ d49304 2 a49305 2 windows uses ‘_’ and ‘0’ at locations where otherwise there would be a space. The default is ‘off’, which means spaces are used. d49307 2 a49308 5 begins and ends, to avoid incorrectly interpreting a space as being part of the the left margin. ‘maint set per-command’ ‘maint show per-command’ d49310 4 a49313 2 GDB can display the resources used by each command. This is useful in debugging performance problems. d49315 2 a49316 2 ‘maint set per-command space [on|off]’ ‘maint show per-command space’ d49320 1 a49320 1 can also be requested by invoking GDB with the ‘--statistics’ d49323 2 a49324 2 ‘maint set per-command time [on|off]’ ‘maint show per-command time’ d49330 2 a49331 2 cost is CPU or, e.g., disk/network latency. Note that the CPU time printed is for GDB only, it does not include the d49335 1 a49335 1 also be requested by invoking GDB with the ‘--statistics’ d49338 2 a49339 2 ‘maint set per-command symtab [on|off]’ ‘maint show per-command symtab’ d49341 2 a49342 2 statistics for each command. If enabled, GDB will display the following information: d49345 1 d49347 1 d49350 2 a49351 2 ‘maint set check-libthread-db [on|off]’ ‘maint show check-libthread-db’ d49356 2 a49357 2 as described in *note set libthread-db-search-path::. For more information about the tests, see *note maint check libthread-db::. d49359 8 a49366 8 ‘maint set gnu-source-highlight enabled [on|off]’ ‘maint show gnu-source-highlight enabled’ Control whether GDB should use the GNU Source Highlight library for applying styling to source code (*note Output Styling::). This will be ‘on’ by default if the GNU Source Highlight library is available. If the GNU Source Highlight library is not available, then this will be ‘off’ by default, and attempting to change this value to ‘on’ will give an error. d49369 2 a49370 2 will use the Python Pygments package for source code styling, if it is available. d49376 2 a49377 2 ‘maint set libopcodes-styling enabled [on|off]’ ‘maint show libopcodes-styling enabled’ d49379 1 a49379 1 (‘libopcodes’) to style disassembler output (*note Output d49383 2 a49384 2 When this option is ‘off’ the builtin disassembler will not be used for styling, GDB will fall back to using the Python Pygments d49387 4 a49390 3 Trying to set this option ‘on’ for an architecture that the builtin disassembler is unable to style will give an error, otherwise, the builtin disassembler will be used to style disassembler output. d49392 1 a49392 1 This option is ‘on’ by default for supported architectures. d49395 2 a49396 2 library when GDB is built for an architecture that supports styling with the builtin disassembler d49398 1 a49398 1 ‘maint info screen’ d49402 2 a49403 2 ‘maint space VALUE’ An alias for ‘maint set per-command space’. A non-zero value d49406 2 a49407 2 ‘maint time VALUE’ An alias for ‘maint set per-command time’. A non-zero value d49410 1 a49410 1 ‘maint translate-address [SECTION] ADDR’ d49414 2 a49415 2 location to the specified address. This is similar to the ‘info address’ command (*note Symbols::), except that this command also d49423 3 a49425 3 ‘maint test-options require-delimiter’ ‘maint test-options unknown-is-error’ ‘maint test-options unknown-is-operand’ d49427 1 a49427 1 options framework. The ‘require-delimiter’ variant requires a d49429 7 a49435 7 ‘unknown-is-error’ and ‘unknown-is-operand’ do not. The ‘unknown-is-error’ variant throws an error on unknown option, while ‘unknown-is-operand’ treats unknown options as the start of the command's operands. When run, the commands output the result of the processed options. When completed, the commands store the internal result of completion in a variable exposed by the ‘maint show test-options-completion-result’ command. d49437 2 a49438 2 ‘maint show test-options-completion-result’ Shows the result of completing the ‘maint test-options’ d49442 4 a49445 4 ‘maint set test-settings KIND’ ‘maint show test-settings KIND’ These are representative commands for each KIND of setting type GDB supports. They are used by the testsuite for exercising the d49448 3 a49450 3 ‘maint set backtrace-on-fatal-signal [on|off]’ ‘maint show backtrace-on-fatal-signal’ When this setting is ‘on’, if GDB itself terminates with a fatal d49453 2 a49454 2 diagnose crashes within GDB in situations where a user is unable to share a corefile with the GDB developers. d49458 1 a49458 1 ‘off’ by default, and attempting to turn this feature on will give d49462 1 a49462 1 is ‘on’ by default. d49464 1 a49464 1 ‘maint wait-for-index-cache’ d49469 3 a49471 3 ‘maint with SETTING [VALUE] [-- COMMAND]’ Like the ‘with’ command, but works with ‘maintenance set’ variables. This is used by the testsuite to exercise the ‘with’ d49474 2 a49475 2 ‘maint ignore-probes [-V|-VERBOSE] [PROVIDER [NAME [OBJFILE]]]’ ‘maint ignore-probes -RESET’ d49477 1 a49477 1 OBJFILE arguments are as in ‘enable probes’ and ‘disable probes’ d49480 1 a49480 1 Here's an example of using ‘maint ignore-probes’: d49495 1 a49495 1 ‘set watchdog NSEC’ d49500 1 a49500 1 ‘show watchdog’ d49544 2 a49545 2 In the examples below, ‘->’ and ‘<-’ are used to indicate transmitted and received data, respectively. d49548 7 a49554 8 notifications, see *note Notification Packets::) are sent as a PACKET. A PACKET is introduced with the character ‘$’, the actual PACKET-DATA, and the terminating character ‘#’ followed by a two-digit CHECKSUM: $PACKET-DATA#CHECKSUM The two-digit CHECKSUM is computed as the modulo 256 sum of all characters between the leading ‘$’ and the trailing ‘#’ (an eight bit d49560 1 a49560 1 $SEQUENCE-ID:PACKET-DATA#CHECKSUM d49563 2 a49564 2 output SEQUENCE-IDs. Stubs that handle packets added since GDB 5.0 must not accept SEQUENCE-ID. d49567 2 a49568 2 first response expected is an acknowledgment: either ‘+’ (to indicate the package was received correctly) or ‘-’ (to request retransmission): d49570 3 a49572 4 -> $PACKET-DATA#CHECKSUM <- + The ‘+’/‘-’ acknowledgments can be disabled once a connection is d49576 2 a49577 2 incorporated in your program) sends a RESPONSE. In the case of step and continue COMMANDs, the response is only sent when the operation has d49580 1 a49580 1 protocol also supports GDB's non-stop execution mode; see *note Remote d49584 1 a49584 1 of ‘#’ and ‘$’ (see ‘X’ packet for additional exceptions). d49586 1 a49586 1 Fields within the packet should be separated using ‘,’ ‘;’ or ‘:’. d49590 1 a49590 1 Implementors should note that prior to GDB 5.0, the character ‘:’ d49600 1 a49600 1 The binary data representation uses ‘7d’ (ASCII ‘}’) as an escape d49602 3 a49604 3 followed by the original character XORed with ‘0x20’. For example, the byte ‘0x7d’ would be transmitted as the two bytes ‘0x7d 0x5d’. The bytes ‘0x23’ (ASCII ‘#’), ‘0x24’ (ASCII ‘$’), and ‘0x7d’ (ASCII ‘}’) d49606 1 a49606 1 ‘0x2a’ (ASCII ‘*’), so that it is not interpreted as the start of a d49611 1 a49611 1 repeated character, followed by a ‘*’ and a repeat count. The repeat d49613 11 a49623 11 value of N is sent as ‘N+29’. For a repeat count greater or equal to 3, this produces a printable ASCII character, e.g. a space (ASCII code 32) for a repeat count of 3. (This is because run-length encoding starts to win for counts 3 or more.) Thus, for example, ‘0* ’ is a run-length encoding of "0000": the space character after ‘*’ means repeat the leading ‘0’ ‘32 - 29 = 3’ more times. The printable characters ‘#’ and ‘$’ or with a numeric value greater than 126 must not be used. Runs of six repeats (‘#’) or seven repeats (‘$’) can be expanded using a repeat count of only five (‘"’). For example, ‘00000000’ can be encoded as ‘0*"00’. d49632 2 a49633 2 spaces to separate its components. For example, a template like ‘foo BAR BAZ’ describes a packet beginning with the three ASCII bytes ‘foo’, d49635 1 a49635 1 space character between the ‘foo’ and the BAR, or between the BAR and d49639 2 a49640 2 example, a template like ‘c [ADDR]’ describes a packet beginning with the single ASCII character ‘c’, possibly followed by an ADDR. d49642 4 a49645 4 At a minimum, a stub is required to support the ‘?’ command to tell GDB the reason for halting, ‘g’ and ‘G’ commands for register access, and the ‘m’ and ‘M’ commands for memory access. Stubs that only control single-threaded targets can implement run control with the ‘c’ d49647 3 a49649 3 hardware-assisted single-stepping, the ‘s’ (step) command. Stubs that support multi-threading targets should support the ‘vCont’ command. All other commands are optional. d49661 4 d49666 1 a49666 6 An empty response (raw character sequence ‘$#00’) means the COMMAND is not supported by the stub. This way it is possible to extend the protocol. A newer GDB can tell if a command is supported based on that response (but see also *note qSupported::). ‘E XX’ d49672 1 a49672 1 ‘E.ERRTEXT’ d49676 1 d49692 4 a49695 4 For example, a template like ‘foo BAR BAZ’ describes a packet beginning with the three ASCII bytes ‘foo’, followed by a BAR, followed directly by a BAZ. GDB does not transmit a space character between the ‘foo’ and the BAR, or between the BAR and the BAZ. d49700 1 a49700 1 also be a literal ‘-1’ to indicate all threads, or ‘0’ to pick any d49705 1 a49705 1 process and thread ID fields, as ‘pPID.TID’. The PID (process) and TID d49707 8 a49714 8 number with target-specific interpretation formatted as a big-endian hex string, literal ‘-1’ to indicate all processes or threads (respectively), or ‘0’ to indicate an arbitrary process or thread. Specifying just a process, as ‘pPID’, is equivalent to ‘pPID.-1’. It is an error to specify all processes but a specific thread, such as ‘p-1.TID’. Note that the ‘p’ prefix is _not_ used for those packets and replies explicitly documented to include a process ID, rather than a THREAD-ID. d49717 2 a49718 2 GDB and the stub report support for the ‘multiprocess’ feature using ‘qSupported’. *Note multiprocess extensions::, for more information. d49725 1 a49725 1 ‘!’ d49727 1 a49727 1 persistent. The ‘R’ packet is used to restart the program being d49731 1 a49731 1 ‘OK’ d49734 1 a49734 1 ‘?’ d49737 2 a49738 2 continue. This packet has a special interpretation when the target is in non-stop mode; see *note Remote Non-Stop::. d49742 2 a49743 2 ‘A ARGLEN,ARGNUM,ARG,...’ Initialized ‘argv[]’ array passed into program. ARGLEN specifies d49745 1 a49745 1 ‘gdbserver’ for more details. d49748 1 a49748 1 ‘OK’ d49751 1 a49751 1 ‘b BAUD’ d49762 3 a49764 3 send some kind of out-of-band message to a specially-setup stub and have the switch happen "in between" packets, so that from remote protocol's point of view, nothing actually happened._ d49766 2 a49767 2 ‘B ADDR,MODE’ Set (MODE is ‘S’) or clear (MODE is ‘C’) a breakpoint at ADDR. d49769 1 a49769 1 Don't use this packet. Use the ‘Z’ and ‘z’ packets instead (*note d49772 1 a49772 1 ‘bc’ d49778 1 a49778 1 ‘bs’ d49784 1 a49784 1 ‘c [ADDR]’ d49788 2 a49789 2 This packet is deprecated for multi-threading support. *Note vCont packet::. d49793 2 a49794 2 ‘C SIG[;ADDR]’ Continue with signal SIG (hex signal number). If ‘;ADDR’ is d49797 2 a49798 2 This packet is deprecated for multi-threading support. *Note vCont packet::. d49802 1 a49802 1 ‘d’ d49808 2 a49809 2 ‘D’ ‘D;PID’ d49811 2 a49812 2 system. It is sent to the remote target before GDB disconnects via the ‘detach’ command. d49820 1 a49820 1 ‘OK’ d49823 4 a49826 4 ‘F RC,EE,CF;XX’ A reply from GDB to an ‘F’ packet sent by the target. This is part of the File-I/O protocol extension. *Note File-I/O Remote Protocol Extension::, for the specification. d49828 1 a49828 1 ‘g’ d49832 1 a49832 1 ‘XX...’ d49836 2 a49837 2 the ‘g’ packet are determined by the target description (*note Target Descriptions::); in the absence of a target d49843 1 a49843 1 literal ‘x’'s in place of the register data digits, to d49845 9 a49853 9 unavailable. For example, when reading registers from a trace frame (*note Using the Collected Data: Analyze Collected Data.), this means that the register has not been collected in the trace frame. When reading registers from a live program, this indicates that the stub has no means to access the register contents, even though the corresponding register is known to exist. Note that if a register truly does not exist on the target, then it is better to not include it in the target description in the first place. d49860 3 a49862 2 -> g <- xxxxxxxx00000000xxxxxxxx00000000 d49864 1 a49864 1 ‘G XX...’ d49869 1 a49869 1 ‘OK’ d49872 3 a49874 3 ‘H OP THREAD-ID’ Set thread for subsequent operations (‘m’, ‘M’, ‘g’, ‘G’, et.al.). Depending on the operation to be performed, OP should be ‘c’ for d49876 1 a49876 1 supporting the ‘vCont’ command is a better option), and ‘g’ for d49878 1 a49878 1 and interpretation described in *note thread-id syntax::. d49881 1 a49881 1 ‘OK’ d49884 2 a49885 2 ‘i [ADDR[,NNN]]’ Step the remote target by a single clock cycle. If ‘,NNN’ is d49889 1 a49889 1 ‘I’ d49893 1 a49893 1 ‘k’ d49899 1 a49899 1 system. For that reason, the ‘k’ packet has no reply. d49908 1 a49908 1 to ‘k’, GDB does not consider the lack of packet acknowledgment to d49911 1 a49911 1 If connected using ‘target extended-remote’, and the target does d49916 1 a49916 1 ‘m ADDR,LENGTH’ d49923 3 a49925 3 word-aligned and LENGTH is a multiple of the word size, the stub is free to use byte accesses, or not. For this reason, this packet may not be suitable for accessing memory-mapped I/O devices. d49928 1 a49928 1 ‘XX...’ d49934 3 a49936 2 Unlike most packets, this packet does not support ‘E.ERRTEXT’-style textual error replies (*note textual error reply::). d49938 1 a49938 1 ‘M ADDR,LENGTH:XX...’ d49944 1 a49944 1 ‘OK’ d49948 1 a49948 1 ‘p N’ d49954 1 a49954 1 ‘XX...’ d49957 1 a49957 1 ‘P N...=R...’ d49963 1 a49963 1 ‘OK’ d49966 4 a49969 4 ‘q NAME PARAMS...’ ‘Q NAME PARAMS...’ General query (‘q’) and set (‘Q’). These packets are described fully in *note General Query Packets::. d49971 1 a49971 1 ‘r’ d49974 1 a49974 1 Don't use this packet; use the ‘R’ packet instead. d49976 1 a49976 1 ‘R XX’ d49981 1 a49981 1 The ‘R’ packet has no reply. d49983 1 a49983 1 ‘s [ADDR]’ d49987 2 a49988 2 This packet is deprecated for multi-threading support. *Note vCont packet::. d49992 2 a49993 2 ‘S SIG[;ADDR]’ Step with signal. This is analogous to the ‘C’ packet, but d49997 2 a49998 2 This packet is deprecated for multi-threading support. *Note vCont packet::. d50002 1 a50002 1 ‘t ADDR:PP,MM’ d50007 1 a50007 1 ‘T THREAD-ID’ d50012 1 a50012 1 ‘OK’ d50015 3 a50017 3 ‘v’ Packets starting with ‘v’ are identified by a multi-letter name, up to the first ‘;’ or ‘?’ (or the end of the packet). d50019 1 a50019 1 ‘vAttach;PID’ d50030 1 a50030 1 ‘Any stop packet’ d50032 2 a50033 1 ‘OK’ d50036 1 a50036 1 ‘vCont[;ACTION[:THREAD-ID]]...’ d50042 1 a50042 1 described in *note thread-id syntax::. If multiprocess extensions d50044 1 a50044 1 specified to match all threads in a process by using the ‘pPID.-1’ d50050 1 a50050 1 ‘c’ d50052 2 a50053 1 ‘C SIG’ d50056 2 a50057 1 ‘s’ d50059 2 a50060 1 ‘S SIG’ d50063 2 a50064 1 ‘t’ d50066 2 a50067 1 ‘r START,END’ d50075 1 a50075 1 equivalent to the ‘s’ action. In other words, single-step d50079 2 a50080 2 (A stop reply may be sent at any point even if the PC is still within the stepping range; for example, it is valid to a50083 2 The optional argument ADDR normally associated with the ‘c’, ‘C’, ‘s’, and ‘S’ packets is not supported in ‘vCont’. d50085 7 a50091 4 The ‘t’ action is only relevant in non-stop mode (*note Remote Non-Stop::) and may be ignored by the stub otherwise. A stop reply should be generated for any affected thread not already stopped. When a thread is stopped by means of a ‘t’ action, the d50093 2 a50094 2 stopped with signal ‘0’, regardless of whether the target uses some other signal as an implementation detail. d50096 1 a50096 1 The server must ignore ‘c’, ‘C’, ‘s’, ‘S’, and ‘r’ actions for d50098 1 a50098 1 ignore ‘t’ actions for threads that are already stopped. d50102 1 a50102 1 ‘vStopped’ packet (*note Remote Non-Stop::). d50104 1 a50104 1 The stub must support ‘vCont’ if it reports support for d50109 2 a50110 2 ‘vCont?’ Request a list of actions supported by the ‘vCont’ packet. d50113 3 a50115 3 ‘vCont[;ACTION...]’ The ‘vCont’ packet is supported. Each ACTION is a supported command in the ‘vCont’ packet. d50117 1 a50117 1 ‘vCtrlC’ d50119 1 a50119 1 terminal. This is the equivalent to reacting to the ‘^C’ (‘\003’, d50126 1 a50126 1 ‘OK’ d50129 1 a50129 1 ‘vFile:OPERATION:PARAMETER...’ d50131 1 a50131 1 *note Host I/O Packets::. d50133 1 a50133 1 ‘vFlashErase:ADDR,LENGTH’ d50137 5 a50141 4 block size appearing in the memory map (*note Memory Map Format::). GDB groups flash memory programming operations together, and sends a ‘vFlashDone’ request after each group; the stub is allowed to delay erase operation until the ‘vFlashDone’ packet is received. d50144 1 a50144 1 ‘OK’ d50147 1 a50147 1 ‘vFlashWrite:ADDR:XX...’ d50149 9 a50157 9 passed in binary form using the same encoding as for the ‘X’ packet (*note Binary Data::). The memory ranges specified by ‘vFlashWrite’ packets preceding a ‘vFlashDone’ packet must not overlap, and must appear in order of increasing addresses (although ‘vFlashErase’ packets for higher addresses may already have been received; the ordering is guaranteed only between ‘vFlashWrite’ packets). If a packet writes to an address that was neither erased by a preceding ‘vFlashErase’ packet nor by some other target-specific method, the results are unpredictable. d50160 1 a50160 1 ‘OK’ d50162 2 a50163 1 ‘E.memtype’ d50166 1 a50166 1 ‘vFlashDone’ d50169 4 a50172 3 ‘vFlashErase’ and ‘vFlashWrite’ packets until a ‘vFlashDone’ packet is received. The contents of the affected regions of flash memory are unpredictable until the ‘vFlashDone’ request is completed. d50174 1 a50174 1 ‘vKill;PID’ d50177 2 a50178 2 in preference to ‘k’ when multiprocess protocol extensions are supported; see *note multiprocess extensions::. d50181 1 a50181 1 ‘OK’ d50184 9 a50192 9 ‘vMustReplyEmpty’ The correct reply to an unknown ‘v’ packet is to return the empty string, however, some older versions of ‘gdbserver’ would incorrectly return ‘OK’ for unknown ‘v’ packets. The ‘vMustReplyEmpty’ is used as a feature test to check how ‘gdbserver’ handles unknown packets, it is important that this packet be handled in the same way as other unknown ‘v’ packets. If this packet is handled differently to other unknown ‘v’ packets d50194 1 a50194 1 specifically around use of ‘vFile:setfs:’. d50196 1 a50196 1 ‘vRun;FILENAME[;ARGUMENT]...’ d50198 4 a50201 3 line. The file and arguments are hex-encoded strings. If FILENAME is an empty string, the stub may use a default program (e.g. the last program run). The program is created in the stopped state. d50207 1 a50207 1 ‘Any stop packet’ d50210 1 a50210 1 ‘vStopped’ d50213 1 a50213 1 ‘X ADDR,LENGTH:XX...’ d50216 1 a50216 1 memory units LENGTH (*note addressable memory unit::); ‘XX...’ is d50220 1 a50220 1 ‘OK’ d50223 3 a50225 3 ‘z TYPE,ADDR,KIND’ ‘Z TYPE,ADDR,KIND’ Insert (‘Z’) or remove (‘z’) a TYPE breakpoint or watchpoint d50232 9 a50240 9 for an unrecognized breakpoint or watchpoint packet TYPE. A remote target shall support either both or neither of a given ‘ZTYPE...’ and ‘zTYPE...’ packet pair. To avoid potential problems with duplicate packets, the operations should be implemented in an idempotent way._ ‘z0,ADDR,KIND’ ‘Z0,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]’ Insert (‘Z0’) or remove (‘z0’) a software breakpoint at address d50250 1 a50250 1 architecture-specific value is being used, it should be ‘0’. KIND d50257 1 a50257 1 See also the ‘swbreak’ stop reason (*note swbreak stop reason::) d50261 1 a50261 1 concatenated without separators. Each expression has the following d50264 1 a50264 1 ‘X LEN,EXPR’ d50268 3 a50270 2 The optional CMD_LIST parameter introduces commands that may be run on the target, rather than being reported back to GDB. The d50277 1 a50277 1 ‘X LEN,EXPR’ d50281 1 d50288 1 a50288 1 ‘OK’ d50291 3 a50293 3 ‘z1,ADDR,KIND’ ‘Z1,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]’ Insert (‘Z1’) or remove (‘z1’) a hardware breakpoint at address d50298 1 a50298 1 COND_LIST, and CMD_LIST arguments have the same meaning as in ‘Z0’ d50305 1 a50305 1 ‘OK’ d50308 3 a50310 3 ‘z2,ADDR,KIND’ ‘Z2,ADDR,KIND’ Insert (‘Z2’) or remove (‘z2’) a write watchpoint at ADDR. The d50314 1 a50314 1 ‘OK’ d50317 3 a50319 3 ‘z3,ADDR,KIND’ ‘Z3,ADDR,KIND’ Insert (‘Z3’) or remove (‘z3’) a read watchpoint at ADDR. The d50323 1 a50323 1 ‘OK’ d50326 3 a50328 3 ‘z4,ADDR,KIND’ ‘Z4,ADDR,KIND’ Insert (‘Z4’) or remove (‘z4’) an access watchpoint at ADDR. The d50332 1 a50332 1 ‘OK’ d50335 1 d50342 5 a50346 5 The ‘C’, ‘c’, ‘S’, ‘s’, ‘vCont’, ‘vAttach’, ‘vRun’, ‘vStopped’, and ‘?’ packets can receive any of the below as a reply. Except for ‘?’ and ‘vStopped’, that reply is only returned when the target halts. In the below the exact meaning of “signal number” is defined by the header ‘include/gdb/signals.h’ in the GDB source code. d50348 2 a50349 2 In non-stop mode, the server will simply reply ‘OK’ to commands such as ‘vCont’; any stop will be the subject of a future notification. d50357 1 a50357 1 ‘S AA’ d50359 1 a50359 1 number). This is equivalent to a ‘T’ response with no N:R pairs. d50361 1 a50361 1 ‘T AA N1:R1;N2:R2;...’ d50363 2 a50364 2 number). This is equivalent to an ‘S’ response, except that the ‘N:R’ pairs can carry values of important registers and other d50367 1 a50367 1 Each ‘N:R’ pair is interpreted as follows: d50369 1 a50369 1 • If N is a hexadecimal number, it is a register number, and the d50374 2 a50375 2 • If N is ‘thread’, then R is the thread ID of the stopped thread, as specified in *note thread-id syntax::. d50377 1 a50377 1 • If N is ‘core’, then R is the hexadecimal number of the core d50380 5 a50384 4 • If N is a recognized “stop reason”, it describes a more specific event that stopped the target. The currently defined stop reasons are listed below. The AA should be ‘05’, the trap signal. At most one stop reason should be present. d50386 1 a50386 1 • Otherwise, GDB should ignore this ‘N:R’ pair and go on to the d50391 3 a50393 3 ‘watch’ ‘rwatch’ ‘awatch’ d50397 2 a50398 2 ‘syscall_entry’ ‘syscall_return’ d50402 1 a50402 1 ‘library’ d50404 1 a50404 1 GDB should use ‘qXfer:libraries:read’ to fetch a new list of d50407 1 a50407 1 ‘replaylog’ d50411 1 a50411 1 of R will be either ‘begin’ or ‘end’. *Note Reverse d50414 1 a50414 1 ‘swbreak’ d50417 2 a50418 2 breakpoint or the breakpoint is hardcoded in the program. The R part must be left empty. d50420 5 a50424 5 On some architectures, such as x86, at the architecture level, when a breakpoint instruction executes the program counter points at the breakpoint address plus an offset. On such targets, the stub is responsible for adjusting the PC to point back at the breakpoint address. d50428 2 a50429 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d50434 1 a50434 1 ‘hwbreak’ d50438 1 a50438 1 The same remarks about ‘qSupported’ and non-stop mode above d50441 5 a50445 5 ‘fork’ The packet indicates that ‘fork’ was called, and R is the thread ID of the new child process, as specified in *note thread-id syntax::. This packet is only applicable to targets that support fork events. d50449 2 a50450 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d50453 5 a50457 5 ‘vfork’ The packet indicates that ‘vfork’ was called, and R is the thread ID of the new child process, as specified in *note thread-id syntax::. This packet is only applicable to targets that support vfork events. d50461 2 a50462 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d50465 1 a50465 1 ‘vforkdone’ d50467 1 a50467 1 has either called ‘exec’ or terminated, so that the address d50474 2 a50475 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d50478 5 a50482 4 ‘exec’ The packet indicates that ‘execve’ was called, and R is the absolute pathname of the file that was executed, in hex. This packet is only applicable to targets that support exec events. d50486 2 a50487 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d50490 5 a50494 5 ‘clone’ The packet indicates that ‘clone’ was called, and R is the thread ID of the new child thread, as specified in *note thread-id syntax::. This packet is only applicable to targets that support clone events. d50497 1 a50497 1 with the *note QThreadOptions:: packet. d50499 1 a50499 1 ‘create’ d50503 2 a50504 2 not be sent by default; GDB requests it with the *note QThreadEvents:: packet. See also the ‘w’ (*note thread exit d50507 3 a50509 2 ‘W AA’ ‘W AA ; process:PID’ d50515 1 a50515 1 multiprocess protocol extensions; see *note multiprocess d50519 2 a50520 2 ‘X AA’ ‘X AA ; process:PID’ d50525 1 a50525 1 for multiprocess protocol extensions; see *note multiprocess d50529 6 a50534 7 ‘w AA ; TID’ The thread exited, and AA is the exit status. This response should not be sent by default; GDB requests it with either the *note QThreadEvents:: or *note QThreadOptions:: packets. See also *note thread create event:: above. AA is formatted as a big-endian hex string. d50536 1 a50536 1 ‘N’ d50542 2 a50543 2 though the process is still alive, and thus no ‘W’ stop reply is sent, no thread is actually executing either. The ‘N’ stop reply d50547 2 a50548 2 ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ feature indicating d50551 2 a50552 2 ‘O XX...’ ‘XX...’ is hex encoding of ASCII data, to be written as the d50555 1 a50555 1 ‘W’, ‘T’, etc. This reply is not permitted in non-stop mode. d50557 1 a50557 1 ‘F CALL-ID,PARAMETER...’ d50564 1 a50564 1 ‘PARAMETER...’ is a list of parameters as defined for this very d50569 2 a50570 2 appropriate ‘F’ packet and keeps up waiting for the next reply packet from the target. The latest ‘C’, ‘c’, ‘S’ or ‘s’ action is d50574 1 d50581 4 a50584 4 Packets starting with ‘q’ are “general query packets”; packets starting with ‘Q’ are “general set packets”. General query and set packets are a semi-unified form for retrieving and sending information to and from the stub. d50588 2 a50589 2 may use a ‘qSymbol’ packet to exchange symbol definitions with the stub. These packet names follow some conventions: d50591 5 a50595 3 • The name must not contain commas, colons or semicolons. • Most GDB query and set packets have a leading upper case letter. • The names of custom vendor packets should use a company prefix, in d50597 2 a50598 2 the Acme Corporation might begin with ‘qacme.foo’ (for querying foos) or ‘Qacme.bar’ (for setting bars). d50601 5 a50605 5 parameters by a ‘:’; the parameters themselves should be separated by ‘,’ or ‘;’. Stubs must be careful to match the full packet name, and check for a separator or the end of the packet, in case two packet names share a common prefix. New packets should not begin with ‘qC’, ‘qP’, or ‘qL’(1). d50607 2 a50608 2 Like the descriptions of the other packets, each description here has a template showing the packet's overall syntax, followed by an d50615 2 a50616 2 ‘QAgent:1’ ‘QAgent:0’ d50620 10 a50629 10 ‘QAllow:OP:VAL...’ Specify which operations GDB expects to request of the target, as a semicolon-separated list of operation name and value pairs. Possible values for OP include ‘WriteReg’, ‘WriteMem’, ‘InsertBreak’, ‘InsertTrace’, ‘InsertFastTrace’, and ‘Stop’. VAL is either 0, indicating that GDB will not request the operation, or 1, indicating that it may. (The target can then use this to set up its own internals optimally, for instance if the debugger never expects to insert breakpoints, it may not need to install its own trap handler.) d50631 1 a50631 1 ‘qC’ d50635 2 a50636 2 ‘QC THREAD-ID’ Where THREAD-ID is a thread ID as documented in *note d50638 2 a50639 1 ‘(anything else)’ d50642 1 a50642 1 ‘qCRC:ADDR,LENGTH’ d50646 1 a50646 1 ‘0xffffffff’ is used to ensure leading zeros affect the CRC. d50652 2 a50653 2 _least_ significant bit of each byte first, and the final result is inverted to detect trailing zeros. d50656 1 a50656 1 ‘C CRC32’ d50659 1 a50659 1 ‘QDisableRandomization:VALUE’ d50665 1 a50665 1 randomization for processes subsequently started via ‘vRun’ d50673 1 a50673 1 ‘OK’ d50677 1 a50677 1 it, by supplying an appropriate ‘qSupported’ response (*note d50681 1 a50681 1 ‘QStartupWithShell:VALUE’ d50684 2 a50685 2 ‘gdbserver’ (*note set startup-with-shell::). This packet is used to inform ‘gdbserver’ whether it should start the inferior using a d50688 2 a50689 2 If VALUE is ‘0’, ‘gdbserver’ will not use a shell to start the inferior. If VALUE is ‘1’, ‘gdbserver’ will use a shell to start d50696 1 a50696 1 ‘OK’ d50700 1 a50700 1 it, by supplying an appropriate ‘qSupported’ response (*note d50704 1 a50704 1 Use of this packet is controlled by the ‘set startup-with-shell’ d50707 1 a50707 1 ‘QEnvironmentHexEncoded:HEX-VALUE’ d50710 1 a50710 1 This packet is used to inform ‘gdbserver’ of an environment d50715 5 a50719 5 of the NAME=VALUE format representing an environment variable. The name of the environment variable is represented by NAME, and the value to be assigned to the environment variable is represented by VALUE. If the variable has no value (i.e., the value is ‘null’), then VALUE will not be present. d50725 1 a50725 1 ‘OK’ d50729 1 a50729 1 it, by supplying an appropriate ‘qSupported’ response (*note d50733 1 a50733 1 This packet is related to the ‘set environment’ command; *note set d50736 1 a50736 1 ‘QEnvironmentUnset:HEX-VALUE’ d50739 2 a50740 2 used to inform ‘gdbserver’ of an environment variable that has been unset by the user on GDB (*note unset environment::). d50749 1 a50749 1 ‘OK’ d50753 1 a50753 1 it, by supplying an appropriate ‘qSupported’ response (*note d50757 1 a50757 1 This packet is related to the ‘unset environment’ command; *note d50760 1 a50760 1 ‘QEnvironmentReset’ d50765 3 a50767 3 initially present in the environment). It is sent to ‘gdbserver’ before the ‘QEnvironmentHexEncoded’ (*note QEnvironmentHexEncoded::) and the ‘QEnvironmentUnset’ (*note d50774 1 a50774 1 ‘OK’ d50778 1 a50778 1 it, by supplying an appropriate ‘qSupported’ response (*note d50782 1 a50782 1 ‘QSetWorkingDir:[DIRECTORY]’ d50790 2 a50791 2 server should reset the inferior's current working directory to its original, empty value. d50797 1 a50797 1 ‘OK’ d50800 5 a50804 5 ‘qfThreadInfo’ ‘qsThreadInfo’ Obtain a list of all active thread IDs from the target (OS). Since there may be too many active threads to fit into one reply packet, this query works iteratively: it may require more than one d50806 2 a50807 2 first query of the sequence will be the ‘qfThreadInfo’ query; subsequent queries in the sequence will be the ‘qsThreadInfo’ d50810 1 a50810 1 NOTE: This packet replaces the ‘qL’ query (see below). d50813 1 a50813 1 ‘m THREAD-ID’ d50815 2 a50816 1 ‘m THREAD-ID,THREAD-ID...’ a50817 2 ‘l’ (lower case letter ‘L’) denotes end of list. d50819 2 a50820 6 In response to each query, the target will reply with a list of one or more thread IDs, separated by commas. GDB will respond to each reply with a request for more thread ids (using the ‘qs’ form of the query), until the target responds with ‘l’ (lower-case ell, for “last”). Refer to *note thread-id syntax::, for the format of the THREAD-ID fields. d50822 8 a50829 1 _Note: GDB will send the ‘qfThreadInfo’ query during the initial d50833 1 a50833 1 ID in the ‘qfThreadInfo’ reply is suitable for being stopped by d50836 3 a50838 3 ‘qGetTLSAddr:THREAD-ID,OFFSET,LM’ Fetch the address associated with thread local storage specified by THREAD-ID, OFFSET, and LM. d50856 3 a50858 3 ‘XX...’ Hex encoded (big endian) bytes representing the address of the thread local storage requested. d50860 1 a50860 1 ‘qGetTIBAddr:THREAD-ID’ d50866 3 a50868 3 ‘XX...’ Hex encoded (big endian) bytes representing the linear address of the thread information block. d50870 2 a50871 2 ‘qL STARTFLAG THREADCOUNT NEXTTHREAD’ Obtain thread information from RTOS. Where: STARTFLAG (one hex d50878 1 a50878 1 Don't use this packet; use the ‘qfThreadInfo’ query instead (see d50882 1 a50882 1 ‘qM COUNT DONE ARGTHREAD THREAD...’ d50887 1 a50887 1 THREAD... is a sequence of thread IDs, THREADID (eight hex d50889 1 a50889 1 ‘remote.c:parse_threadlist_response()’. d50891 1 a50891 1 ‘qMemTags:START ADDRESS,LENGTH:TYPE’ d50893 3 a50895 3 [START ADDRESS, START ADDRESS + LENGTH). The target is responsible for calculating how many tags will be returned, as this is architecture-specific. d50905 1 a50905 1 for memory tagging via ‘qSupported’. d50908 1 a50908 1 ‘MXX...’ a50911 179 ‘qIsAddressTagged:ADDRESS’ Check if address ADDRESS is in a memory tagged region; if it is, it's said to be “tagged”. The target is responsible for checking it, as this is architecture-specific. ADDRESS is the address to be checked. Reply: Replies to this packet should all be in two hex digit format, as follows: ‘‘01’’ Address ADDRESS is tagged. ‘‘00’’ Address ADDRESS is not tagged. ‘QMemTags:START ADDRESS,LENGTH:TYPE:TAG BYTES’ Store memory tags of type TYPE to the address range [START ADDRESS, START ADDRESS + LENGTH). The target is responsible for interpreting the type, the tag bytes and modifying the memory tag granules accordingly, given this is architecture-specific. The interpretation of how many tags (NT) should be written to how many memory tag granules (NG) is also architecture-specific. The behavior is implementation-specific, but the following is suggested. If the number of memory tags, NT, is greater than or equal to the number of memory tag granules, NG, only NG tags will be stored. If NT is less than NG, the behavior is that of a fill operation, and the tag bytes will be used as a pattern that will get repeated until NG tags are stored. START ADDRESS is the starting address of the memory range. The address does not have any restriction on alignment or size. LENGTH is the length, in bytes, of the memory range. TYPE is the type of tag the request wants to fetch. The type is a signed integer. TAG BYTES is a sequence of hex encoded uninterpreted bytes which will be interpreted by the target. Each pair of hex digits is interpreted as a single byte. GDB will only send this packet if the stub has advertised support for memory tagging via ‘qSupported’. Reply: ‘OK’ The request was successful and the memory tag granules were modified accordingly. ‘qOffsets’ Get section offsets that the target used when relocating the downloaded image. Reply: ‘Text=XXX;Data=YYY[;Bss=ZZZ]’ Relocate the ‘Text’ section by XXX from its original address. Relocate the ‘Data’ section by YYY from its original address. If the object file format provides segment information (e.g. ELF ‘PT_LOAD’ program headers), GDB will relocate entire segments by the supplied offsets. _Note: while a ‘Bss’ offset may be included in the response, GDB ignores this and instead applies the ‘Data’ offset to the ‘Bss’ section._ ‘TextSeg=XXX[;DataSeg=YYY]’ Relocate the first segment of the object file, which conventionally contains program code, to a starting address of XXX. If ‘DataSeg’ is specified, relocate the second segment, which conventionally contains modifiable data, to a starting address of YYY. GDB will report an error if the object file does not contain segment information, or does not contain at least as many segments as mentioned in the reply. Extra segments are kept at fixed offsets relative to the last relocated segment. ‘qP MODE THREAD-ID’ Returns information on THREAD-ID. Where: MODE is a hex encoded 32 bit mode; THREAD-ID is a thread ID (*note thread-id syntax::). Don't use this packet; use the ‘qThreadExtraInfo’ query instead (see below). Reply: see ‘remote.c:remote_unpack_thread_info_response()’. ‘QNonStop:1’ ‘QNonStop:0’ Enter non-stop (‘QNonStop:1’) or all-stop (‘QNonStop:0’) mode. *Note Remote Non-Stop::, for more information. Reply: ‘OK’ The request succeeded. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). Use of this packet is controlled by the ‘set non-stop’ command; *note Non-Stop Mode::. ‘QCatchSyscalls:1 [;SYSNO]...’ ‘QCatchSyscalls:0’ Enable (‘QCatchSyscalls:1’) or disable (‘QCatchSyscalls:0’) catching syscalls from the inferior process. For ‘QCatchSyscalls:1’, each listed syscall SYSNO (encoded in hex) should be reported to GDB. If no syscall SYSNO is listed, every system call should be reported. Note that if a syscall not in the list is reported, GDB will still filter the event according to its own list from all corresponding ‘catch syscall’ commands. However, it is more efficient to only report the requested syscalls. Multiple ‘QCatchSyscalls:1’ packets do not combine; any earlier ‘QCatchSyscalls:1’ list is completely replaced by the new list. If the inferior process execs, the state of ‘QCatchSyscalls’ is kept for the new process too. On targets where exec may affect syscall numbers, for example with exec between 32 and 64-bit processes, the client should send a new packet with the new syscall list. Reply: ‘OK’ The request succeeded. Use of this packet is controlled by the ‘set remote catch-syscalls’ command (*note set remote catch-syscalls: Remote Configuration.). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘QPassSignals: SIGNAL [;SIGNAL]...’ Each listed SIGNAL should be passed directly to the inferior process. Signals are numbered identically to continue packets and stop replies (*note Stop Reply Packets::). Each SIGNAL list item should be strictly greater than the previous item. These signals do not need to stop the inferior, or be reported to GDB. All other signals should be reported to GDB. Multiple ‘QPassSignals’ packets do not combine; any earlier ‘QPassSignals’ list is completely replaced by the new list. This packet improves performance when using ‘handle SIGNAL nostop noprint pass’. Reply: ‘OK’ The request succeeded. Use of this packet is controlled by the ‘set remote pass-signals’ command (*note set remote pass-signals: Remote Configuration.). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘QProgramSignals: SIGNAL [;SIGNAL]...’ Each listed SIGNAL may be delivered to the inferior process. Others should be silently discarded. In some cases, the remote stub may need to decide whether to deliver a signal to the program or not without GDB involvement. One example of that is while detaching -- the program's threads may have stopped for signals that haven't yet had a chance of being reported to GDB, and so the remote stub can use the signal list specified by this packet to know whether to deliver or ignore those pending signals. This does not influence whether to deliver a signal as requested by a resumption packet (*note vCont packet::). Signals are numbered identically to continue packets and stop replies (*note Stop Reply Packets::). Each SIGNAL list item should be strictly greater than the previous item. Multiple ‘QProgramSignals’ packets do not combine; any earlier ‘QProgramSignals’ list is completely replaced by the new list. d50913 2 a50914 3 Reply: ‘OK’ The request succeeded. d50916 5 a50920 22 Use of this packet is controlled by the ‘set remote program-signals’ command (*note set remote program-signals: Remote Configuration.). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘QThreadEvents:1’ ‘QThreadEvents:0’ Enable (‘QThreadEvents:1’) or disable (‘QThreadEvents:0’) reporting of thread create and exit events. *Note thread create event::, for the reply specifications. For example, this is used in non-stop mode when GDB stops a set of threads and synchronously waits for the their corresponding stop replies. Without exit events, if one of the threads exits, GDB would hang forever not knowing that it should no longer expect a stop for that same thread. GDB does not enable this feature unless the stub reports that it supports it by including ‘QThreadEvents+’ in its ‘qSupported’ reply. This packet always enables/disables event reporting for all threads of all processes under control of the remote stub. For per-thread control of optional event reporting, see the *note QThreadOptions:: a50922 14247 Reply: ‘OK’ The request succeeded. Use of this packet is controlled by the ‘set remote thread-events’ command (*note set remote thread-events: Remote Configuration.). ‘QThreadOptions[;OPTIONS[:THREAD-ID]]...’ For each inferior thread, the last OPTIONS in the list with a matching THREAD-ID are applied. Any options previously set on a thread are discarded and replaced by the new options specified. Threads that do not match any THREAD-ID retain their previously-set options. Thread IDs are specified using the syntax described in *note thread-id syntax::. If multiprocess extensions (*note multiprocess extensions::) are supported, options can be specified to apply to all threads of a process by using the ‘pPID.-1’ form of THREAD-ID. Options with no THREAD-ID apply to all threads. Specifying no options value is an error. Zero is a valid value. OPTIONS is an hexadecimal integer specifying the enabled thread options, and is the bitwise ‘OR’ of the following values. All values are given in hexadecimal representation. ‘GDB_THREAD_OPTION_CLONE (0x1)’ Report thread clone events (*note thread clone event::). This is only meaningful for targets that support clone events (e.g., GNU/Linux systems). ‘GDB_THREAD_OPTION_EXIT (0x2)’ Report thread exit events (*note thread exit event::). For example, GDB enables the ‘GDB_THREAD_OPTION_EXIT’ and ‘GDB_THREAD_OPTION_CLONE’ options when single-stepping a thread past a breakpoint, for the following reasons: • If the single-stepped thread exits (e.g., it executes a thread exit system call), enabling ‘GDB_THREAD_OPTION_EXIT’ prevents GDB from waiting forever, not knowing that it should no longer expect a stop for that same thread, and blocking other threads from progressing. • If the single-stepped thread spawns a new clone child (i.e., it executes a clone system call), enabling ‘GDB_THREAD_OPTION_CLONE’ halts the cloned thread before it executes any instructions, and thus prevents the following problematic situations: − If the breakpoint is stepped-over in-line, the spawned thread would incorrectly run free while the breakpoint being stepped over is not inserted, and thus the cloned thread may potentially run past the breakpoint without stopping for it; − If displaced (out-of-line) stepping is used, the cloned thread starts running at the out-of-line PC, leading to undefined behavior, usually crashing or corrupting data. New threads start with thread options cleared. GDB does not enable this feature unless the stub reports that it supports it by including ‘QThreadOptions=SUPPORTED_OPTIONS’ in its ‘qSupported’ reply. Reply: ‘OK’ The request succeeded. Use of this packet is controlled by the ‘set remote thread-options’ command (*note set remote thread-options: Remote Configuration.). ‘qRcmd,COMMAND’ COMMAND (hex encoded) is passed to the local interpreter for execution. Invalid commands should be reported using the output string. Before the final result packet, the target may also respond with a number of intermediate ‘OOUTPUT’ console output packets. _Implementors should note that providing access to a stubs's interpreter may have security implications_. Reply: ‘OK’ A command response with no output. ‘OUTPUT’ A command response with the hex encoded output string OUTPUT. Unlike most packets, this packet does not support ‘E.ERRTEXT’-style textual error replies (*note textual error reply::). (Note that the ‘qRcmd’ packet's name is separated from the command by a ‘,’, not a ‘:’, contrary to the naming conventions above. Please don't use this packet as a model for new packets.) ‘qSearch:memory:ADDRESS;LENGTH;SEARCH-PATTERN’ Search LENGTH bytes at ADDRESS for SEARCH-PATTERN. Both ADDRESS and LENGTH are encoded in hex; SEARCH-PATTERN is a sequence of bytes, also hex encoded. Reply: ‘0’ The pattern was not found. ‘1,address’ The pattern was found at ADDRESS. ‘QStartNoAckMode’ Request that the remote stub disable the normal ‘+’/‘-’ protocol acknowledgments (*note Packet Acknowledgment::). Reply: ‘OK’ The stub has switched to no-acknowledgment mode. GDB acknowledges this response, but neither the stub nor GDB shall send or expect further ‘+’/‘-’ acknowledgments in the current connection. ‘qSupported [:GDBFEATURE [;GDBFEATURE]... ]’ Tell the remote stub about features supported by GDB, and query the stub for features it supports. This packet allows GDB and the remote stub to take advantage of each others' features. ‘qSupported’ also consolidates multiple feature probes at startup, to improve GDB performance--a single larger packet performs better than multiple smaller probe packets on high-latency links. Some features may enable behavior which must not be on by default, e.g. because it would confuse older clients or stubs. Other features may describe packets which could be automatically probed for, but are not. These features must be reported before GDB will use them. This "default unsupported" behavior is not appropriate for all packets, but it helps to keep the initial connection time under control with new versions of GDB which support increasing numbers of packets. Reply: ‘STUBFEATURE [;STUBFEATURE]...’ The stub supports or does not support each returned STUBFEATURE, depending on the form of each STUBFEATURE (see below for the possible forms). The allowed forms for each feature (either a GDBFEATURE in the ‘qSupported’ packet, or a STUBFEATURE in the response) are: ‘NAME=VALUE’ The remote protocol feature NAME is supported, and associated with the specified VALUE. The format of VALUE depends on the feature, but it must not include a semicolon. ‘NAME+’ The remote protocol feature NAME is supported, and does not need an associated value. ‘NAME-’ The remote protocol feature NAME is not supported. ‘NAME?’ The remote protocol feature NAME may be supported, and GDB should auto-detect support in some other way when it is needed. This form will not be used for GDBFEATURE notifications, but may be used for STUBFEATURE responses. Whenever the stub receives a ‘qSupported’ request, the supplied set of GDB features should override any previous request. This allows GDB to put the stub in a known state, even if the stub had previously been communicating with a different version of GDB. The following values of GDBFEATURE (for the packet sent by GDB) are defined: ‘multiprocess’ This feature indicates whether GDB supports multiprocess extensions to the remote protocol. GDB does not use such extensions unless the stub also reports that it supports them by including ‘multiprocess+’ in its ‘qSupported’ reply. *Note multiprocess extensions::, for details. ‘xmlRegisters’ This feature indicates that GDB supports the XML target description. If the stub sees ‘xmlRegisters=’ with target specific strings separated by a comma, it will report register description. ‘qRelocInsn’ This feature indicates whether GDB supports the ‘qRelocInsn’ packet (*note Relocate instruction reply packet: Tracepoint Packets.). ‘swbreak’ This feature indicates whether GDB supports the swbreak stop reason in stop replies. *Note swbreak stop reason::, for details. ‘hwbreak’ This feature indicates whether GDB supports the hwbreak stop reason in stop replies. *Note swbreak stop reason::, for details. ‘fork-events’ This feature indicates whether GDB supports fork event extensions to the remote protocol. GDB does not use such extensions unless the stub also reports that it supports them by including ‘fork-events+’ in its ‘qSupported’ reply. ‘vfork-events’ This feature indicates whether GDB supports vfork event extensions to the remote protocol. GDB does not use such extensions unless the stub also reports that it supports them by including ‘vfork-events+’ in its ‘qSupported’ reply. ‘exec-events’ This feature indicates whether GDB supports exec event extensions to the remote protocol. GDB does not use such extensions unless the stub also reports that it supports them by including ‘exec-events+’ in its ‘qSupported’ reply. ‘vContSupported’ This feature indicates whether GDB wants to know the supported actions in the reply to ‘vCont?’ packet. Stubs should ignore any unknown values for GDBFEATURE. Any GDB which sends a ‘qSupported’ packet supports receiving packets of unlimited length (earlier versions of GDB may reject overly long responses). Additional values for GDBFEATURE may be defined in the future to let the stub take advantage of new features in GDB, e.g. incompatible improvements in the remote protocol--the ‘multiprocess’ feature is an example of such a feature. The stub's reply should be independent of the GDBFEATURE entries sent by GDB; first GDB describes all the features it supports, and then the stub replies with all the features it supports. Similarly, GDB will silently ignore unrecognized stub feature responses, as long as each response uses one of the standard forms. Some features are flags. A stub which supports a flag feature should respond with a ‘+’ form response. Other features require values, and the stub should respond with an ‘=’ form response. Each feature has a default value, which GDB will use if ‘qSupported’ is not available or if the feature is not mentioned in the ‘qSupported’ response. The default values are fixed; a stub is free to omit any feature responses that match the defaults. Not all features can be probed, but for those which can, the probing mechanism is useful: in some cases, a stub's internal architecture may not allow the protocol layer to know some information about the underlying target in advance. This is especially common in stubs which may be configured for multiple targets. These are the currently defined stub features and their properties: Feature Name Value Default Probe Required Allowed ‘PacketSize’ Yes ‘-’ No ‘qXfer:auxv:read’ No ‘-’ Yes ‘qXfer:btrace:read’ No ‘-’ Yes ‘qXfer:btrace-conf:read’ No ‘-’ Yes ‘qXfer:exec-file:read’ No ‘-’ Yes ‘qXfer:features:read’ No ‘-’ Yes ‘qXfer:libraries:read’ No ‘-’ Yes ‘qXfer:libraries-svr4:read’No ‘-’ Yes ‘augmented-libraries-svr4-read’No ‘-’ No ‘qXfer:memory-map:read’ No ‘-’ Yes ‘qXfer:sdata:read’ No ‘-’ Yes ‘qXfer:siginfo:read’ No ‘-’ Yes ‘qXfer:siginfo:write’ No ‘-’ Yes ‘qXfer:threads:read’ No ‘-’ Yes ‘qXfer:traceframe-info:read’No ‘-’ Yes ‘qXfer:uib:read’ No ‘-’ Yes ‘qXfer:fdpic:read’ No ‘-’ Yes ‘Qbtrace:off’ Yes ‘-’ Yes ‘Qbtrace:bts’ Yes ‘-’ Yes ‘Qbtrace:pt’ Yes ‘-’ Yes ‘Qbtrace-conf:bts:size’ Yes ‘-’ Yes ‘Qbtrace-conf:pt:size’ Yes ‘-’ Yes ‘QNonStop’ No ‘-’ Yes ‘QCatchSyscalls’ No ‘-’ Yes ‘QPassSignals’ No ‘-’ Yes ‘QStartNoAckMode’ No ‘-’ Yes ‘multiprocess’ No ‘-’ No ‘ConditionalBreakpoints’ No ‘-’ No ‘ConditionalTracepoints’ No ‘-’ No ‘ReverseContinue’ No ‘-’ No ‘ReverseStep’ No ‘-’ No ‘TracepointSource’ No ‘-’ No ‘QAgent’ No ‘-’ No ‘QAllow’ No ‘-’ No ‘QDisableRandomization’ No ‘-’ No ‘EnableDisableTracepoints’No ‘-’ No ‘QTBuffer:size’ No ‘-’ No ‘tracenz’ No ‘-’ No ‘BreakpointCommands’ No ‘-’ No ‘swbreak’ No ‘-’ No ‘hwbreak’ No ‘-’ No ‘fork-events’ No ‘-’ No ‘vfork-events’ No ‘-’ No ‘exec-events’ No ‘-’ No ‘QThreadEvents’ No ‘-’ No ‘QThreadOptions’ Yes ‘-’ No ‘no-resumed’ No ‘-’ No ‘memory-tagging’ No ‘-’ No These are the currently defined stub features, in more detail: ‘PacketSize=BYTES’ The remote stub can accept packets up to at least BYTES in length. GDB will send packets up to this size for bulk transfers, and will never send larger packets. This is a limit on the data characters in the packet, not including the frame and checksum. There is no trailing NUL byte in a remote protocol packet; if the stub stores packets in a NUL-terminated format, it should allow an extra byte in its buffer for the NUL. If this stub feature is not supported, GDB guesses based on the size of the ‘g’ packet response. ‘qXfer:auxv:read’ The remote stub understands the ‘qXfer:auxv:read’ packet (*note qXfer auxiliary vector read::). ‘qXfer:btrace:read’ The remote stub understands the ‘qXfer:btrace:read’ packet (*note qXfer btrace read::). ‘qXfer:btrace-conf:read’ The remote stub understands the ‘qXfer:btrace-conf:read’ packet (*note qXfer btrace-conf read::). ‘qXfer:exec-file:read’ The remote stub understands the ‘qXfer:exec-file:read’ packet (*note qXfer executable filename read::). ‘qXfer:features:read’ The remote stub understands the ‘qXfer:features:read’ packet (*note qXfer target description read::). ‘qXfer:libraries:read’ The remote stub understands the ‘qXfer:libraries:read’ packet (*note qXfer library list read::). ‘qXfer:libraries-svr4:read’ The remote stub understands the ‘qXfer:libraries-svr4:read’ packet (*note qXfer svr4 library list read::). ‘augmented-libraries-svr4-read’ The remote stub understands the augmented form of the ‘qXfer:libraries-svr4:read’ packet (*note qXfer svr4 library list read::). ‘qXfer:memory-map:read’ The remote stub understands the ‘qXfer:memory-map:read’ packet (*note qXfer memory map read::). ‘qXfer:sdata:read’ The remote stub understands the ‘qXfer:sdata:read’ packet (*note qXfer sdata read::). ‘qXfer:siginfo:read’ The remote stub understands the ‘qXfer:siginfo:read’ packet (*note qXfer siginfo read::). ‘qXfer:siginfo:write’ The remote stub understands the ‘qXfer:siginfo:write’ packet (*note qXfer siginfo write::). ‘qXfer:threads:read’ The remote stub understands the ‘qXfer:threads:read’ packet (*note qXfer threads read::). ‘qXfer:traceframe-info:read’ The remote stub understands the ‘qXfer:traceframe-info:read’ packet (*note qXfer traceframe info read::). ‘qXfer:uib:read’ The remote stub understands the ‘qXfer:uib:read’ packet (*note qXfer unwind info block::). ‘qXfer:fdpic:read’ The remote stub understands the ‘qXfer:fdpic:read’ packet (*note qXfer fdpic loadmap read::). ‘QNonStop’ The remote stub understands the ‘QNonStop’ packet (*note QNonStop::). ‘QCatchSyscalls’ The remote stub understands the ‘QCatchSyscalls’ packet (*note QCatchSyscalls::). ‘QPassSignals’ The remote stub understands the ‘QPassSignals’ packet (*note QPassSignals::). ‘QStartNoAckMode’ The remote stub understands the ‘QStartNoAckMode’ packet and prefers to operate in no-acknowledgment mode. *Note Packet Acknowledgment::. ‘multiprocess’ The remote stub understands the multiprocess extensions to the remote protocol syntax. The multiprocess extensions affect the syntax of thread IDs in both packets and replies (*note thread-id syntax::), and add process IDs to the ‘D’ packet and ‘W’ and ‘X’ replies. Note that reporting this feature indicates support for the syntactic extensions only, not that the stub necessarily supports debugging of more than one process at a time. The stub must not use multiprocess extensions in packet replies unless GDB has also indicated it supports them in its ‘qSupported’ request. ‘qXfer:osdata:read’ The remote stub understands the ‘qXfer:osdata:read’ packet ((*note qXfer osdata read::). ‘ConditionalBreakpoints’ The target accepts and implements evaluation of conditional expressions defined for breakpoints. The target will only report breakpoint triggers when such conditions are true (*note Break Conditions: Conditions.). ‘ConditionalTracepoints’ The remote stub accepts and implements conditional expressions defined for tracepoints (*note Tracepoint Conditions::). ‘ReverseContinue’ The remote stub accepts and implements the reverse continue packet (*note bc::). ‘ReverseStep’ The remote stub accepts and implements the reverse step packet (*note bs::). ‘TracepointSource’ The remote stub understands the ‘QTDPsrc’ packet that supplies the source form of tracepoint definitions. ‘QAgent’ The remote stub understands the ‘QAgent’ packet. ‘QAllow’ The remote stub understands the ‘QAllow’ packet. ‘QDisableRandomization’ The remote stub understands the ‘QDisableRandomization’ packet. ‘StaticTracepoint’ The remote stub supports static tracepoints. ‘InstallInTrace’ The remote stub supports installing tracepoint in tracing. ‘EnableDisableTracepoints’ The remote stub supports the ‘QTEnable’ (*note QTEnable::) and ‘QTDisable’ (*note QTDisable::) packets that allow tracepoints to be enabled and disabled while a trace experiment is running. ‘QTBuffer:size’ The remote stub supports the ‘QTBuffer:size’ (*note QTBuffer-size::) packet that allows to change the size of the trace buffer. ‘tracenz’ The remote stub supports the ‘tracenz’ bytecode for collecting strings. See *note Bytecode Descriptions:: for details about the bytecode. ‘BreakpointCommands’ The remote stub supports running a breakpoint's command list itself, rather than reporting the hit to GDB. ‘Qbtrace:off’ The remote stub understands the ‘Qbtrace:off’ packet. ‘Qbtrace:bts’ The remote stub understands the ‘Qbtrace:bts’ packet. ‘Qbtrace:pt’ The remote stub understands the ‘Qbtrace:pt’ packet. ‘Qbtrace-conf:bts:size’ The remote stub understands the ‘Qbtrace-conf:bts:size’ packet. ‘Qbtrace-conf:pt:size’ The remote stub understands the ‘Qbtrace-conf:pt:size’ packet. ‘swbreak’ The remote stub reports the ‘swbreak’ stop reason for memory breakpoints. ‘hwbreak’ The remote stub reports the ‘hwbreak’ stop reason for hardware breakpoints. ‘fork-events’ The remote stub reports the ‘fork’ stop reason for fork events. ‘vfork-events’ The remote stub reports the ‘vfork’ stop reason for vfork events and vforkdone events. ‘exec-events’ The remote stub reports the ‘exec’ stop reason for exec events. ‘vContSupported’ The remote stub reports the supported actions in the reply to ‘vCont?’ packet. ‘QThreadEvents’ The remote stub understands the ‘QThreadEvents’ packet. ‘QThreadOptions=SUPPORTED_OPTIONS’ The remote stub understands the ‘QThreadOptions’ packet. SUPPORTED_OPTIONS indicates the set of thread options the remote stub supports. SUPPORTED_OPTIONS has the same format as the OPTIONS parameter of the ‘QThreadOptions’ packet, described at *note QThreadOptions::. ‘no-resumed’ The remote stub reports the ‘N’ stop reply. ‘memory-tagging’ The remote stub supports and implements the required memory tagging functionality and understands the ‘qMemTags’ (*note qMemTags::) and ‘QMemTags’ (*note QMemTags::) packets. For AArch64 GNU/Linux systems, this feature can require access to the ‘/proc/PID/smaps’ file so memory mapping page flags can be inspected, if ‘qIsAddressTagged’ (*note qIsAddressTagged::) packet is not supported by the stub. Access to the ‘/proc/PID/smaps’ file is done via ‘vFile’ requests. ‘qSymbol::’ Notify the target that GDB is prepared to serve symbol lookup requests. Accept requests from the target for the values of symbols. Reply: ‘OK’ The target does not need to look up any (more) symbols. ‘qSymbol:SYM_NAME’ The target requests the value of symbol SYM_NAME (hex encoded). GDB may provide the value by using the ‘qSymbol:SYM_VALUE:SYM_NAME’ message, described below. ‘qSymbol:SYM_VALUE:SYM_NAME’ Set the value of SYM_NAME to SYM_VALUE. SYM_NAME (hex encoded) is the name of a symbol whose value the target has previously requested. SYM_VALUE (hex) is the value for symbol SYM_NAME. If GDB cannot supply a value for SYM_NAME, then this field will be empty. Reply: ‘OK’ The target does not need to look up any (more) symbols. ‘qSymbol:SYM_NAME’ The target requests the value of a new symbol SYM_NAME (hex encoded). GDB will continue to supply the values of symbols (if available), until the target ceases to request them. ‘qTBuffer’ ‘QTBuffer’ ‘QTDisconnected’ ‘QTDP’ ‘QTDPsrc’ ‘QTDV’ ‘qTfP’ ‘qTfV’ ‘QTFrame’ ‘qTMinFTPILen’ *Note Tracepoint Packets::. ‘qThreadExtraInfo,THREAD-ID’ Obtain from the target OS a printable string description of thread attributes for the thread THREAD-ID; see *note thread-id syntax::, for the forms of THREAD-ID. This string may contain anything that the target OS thinks is interesting for GDB to tell the user about the thread. The string is displayed in GDB's ‘info threads’ display. Some examples of possible thread extra info strings are ‘Runnable’, or ‘Blocked on Mutex’. Reply: ‘XX...’ Where ‘XX...’ is a hex encoding of ASCII data, comprising the printable string containing the extra information about the thread's attributes. (Note that the ‘qThreadExtraInfo’ packet's name is separated from the command by a ‘,’, not a ‘:’, contrary to the naming conventions above. Please don't use this packet as a model for new packets.) ‘QTNotes’ ‘qTP’ ‘QTSave’ ‘qTsP’ ‘qTsV’ ‘QTStart’ ‘QTStop’ ‘QTEnable’ ‘QTDisable’ ‘QTinit’ ‘QTro’ ‘qTStatus’ ‘qTV’ ‘qTfSTM’ ‘qTsSTM’ ‘qTSTMat’ *Note Tracepoint Packets::. ‘qXfer:OBJECT:read:ANNEX:OFFSET,LENGTH’ Read uninterpreted bytes from the target's special data area identified by the keyword OBJECT. Request LENGTH bytes starting at OFFSET bytes into the data. The content and encoding of ANNEX is specific to OBJECT; it can supply additional details about what data to access. Reply: ‘m DATA’ Data DATA (*note Binary Data::) has been read from the target. There may be more data at a higher address (although it is permitted to return ‘m’ even for the last valid block of data, as long as at least one byte of data was read). It is possible for DATA to have fewer bytes than the LENGTH in the request. ‘l DATA’ Data DATA (*note Binary Data::) has been read from the target. There is no more data to be read. It is possible for DATA to have fewer bytes than the LENGTH in the request. ‘l’ The OFFSET in the request is at the end of the data. There is no more data to be read. Here are the specific requests of this form defined so far. All the ‘qXfer:OBJECT:read:...’ requests use the same reply formats, listed above. ‘qXfer:auxv:read::OFFSET,LENGTH’ Access the target's “auxiliary vector”. *Note auxiliary vector: OS Information. Note ANNEX must be empty. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:btrace:read:ANNEX:OFFSET,LENGTH’ Return a description of the current branch trace. *Note Branch Trace Format::. The annex part of the generic ‘qXfer’ packet may have one of the following values: ‘all’ Returns all available branch trace. ‘new’ Returns all available branch trace if the branch trace changed since the last read request. ‘delta’ Returns the new branch trace since the last read request. Adds a new block to the end of the trace that begins at zero and ends at the source location of the first branch in the trace buffer. This extra block is used to stitch traces together. If the trace buffer overflowed, returns an error indicating the overflow. This packet is not probed by default; the remote stub must request it by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:btrace-conf:read::OFFSET,LENGTH’ Return a description of the current branch trace configuration. *Note Branch Trace Configuration Format::. This packet is not probed by default; the remote stub must request it by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:exec-file:read:ANNEX:OFFSET,LENGTH’ Return the full absolute name of the file that was executed to create a process running on the remote system. The annex specifies the numeric process ID of the process to query, encoded as a hexadecimal number. If the annex part is empty the remote stub should return the filename corresponding to the currently executing process. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:features:read:ANNEX:OFFSET,LENGTH’ Access the “target description”. *Note Target Descriptions::. The annex specifies which XML document to access. The main description is always loaded from the ‘target.xml’ annex. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:libraries:read:ANNEX:OFFSET,LENGTH’ Access the target's list of loaded libraries. *Note Library List Format::. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer read::). Targets which maintain a list of libraries in the program's memory do not need to implement this packet; it is designed for platforms where the operating system manages the list of loaded libraries. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:libraries-svr4:read:ANNEX:OFFSET,LENGTH’ Access the target's list of loaded libraries when the target is an SVR4 platform. *Note Library List Format for SVR4 Targets::. The annex part of the generic ‘qXfer’ packet must be empty unless the remote stub indicated it supports the augmented form of this packet by supplying an appropriate ‘qSupported’ response (*note qXfer read::, *note qSupported::). This packet is optional for better performance on SVR4 targets. GDB uses memory read packets to read the SVR4 library list otherwise. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). If the remote stub indicates it supports the augmented form of this packet then the annex part of the generic ‘qXfer’ packet may contain a semicolon-separated list of ‘NAME=VALUE’ arguments. The currently supported arguments are: ‘start=ADDRESS’ A hexadecimal number specifying the address of the ‘struct link_map’ to start reading the library list from. If unset or zero then the first ‘struct link_map’ in the library list will be chosen as the starting point. ‘prev=ADDRESS’ A hexadecimal number specifying the address of the ‘struct link_map’ immediately preceding the ‘struct link_map’ specified by the ‘start’ argument. If unset or zero then the remote stub will expect that no ‘struct link_map’ exists prior to the starting point. ‘lmid=LMID’ A hexadecimal number specifying a namespace identifier. This is currently only used together with ‘start’ to provide the namespace identifier back to GDB in the response. GDB will only provide values that were previously reported to it. If unset, the response will include ‘lmid="0x0"’. Arguments that are not understood by the remote stub will be silently ignored. ‘qXfer:memory-map:read::OFFSET,LENGTH’ Access the target's “memory-map”. *Note Memory Map Format::. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer read::). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:sdata:read::OFFSET,LENGTH’ Read contents of the extra collected static tracepoint marker information. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer read::). *Note Tracepoint Action Lists: Tracepoint Actions. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:siginfo:read::OFFSET,LENGTH’ Read contents of the extra signal information on the target system. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer read::). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:threads:read::OFFSET,LENGTH’ Access the list of threads on target. *Note Thread List Format::. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer read::). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:traceframe-info:read::OFFSET,LENGTH’ Return a description of the current traceframe's contents. *Note Traceframe Info Format::. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer read::). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:uib:read:PC:OFFSET,LENGTH’ Return the unwind information block for PC. This packet is used on OpenVMS/ia64 to ask the kernel unwind information. This packet is not probed by default. ‘qXfer:fdpic:read:ANNEX:OFFSET,LENGTH’ Read contents of ‘loadmap’s on the target system. The annex, either ‘exec’ or ‘interp’, specifies which ‘loadmap’, executable ‘loadmap’ or interpreter ‘loadmap’ to read. This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:osdata:read::OFFSET,LENGTH’ Access the target's “operating system information”. *Note Operating System Information::. ‘qXfer:OBJECT:write:ANNEX:OFFSET:DATA...’ Write uninterpreted bytes into the target's special data area identified by the keyword OBJECT, starting at OFFSET bytes into the data. The binary-encoded data (*note Binary Data::) to be written is given by DATA.... The content and encoding of ANNEX is specific to OBJECT; it can supply additional details about what data to access. Reply: ‘NN’ NN (hex encoded) is the number of bytes written. This may be fewer bytes than supplied in the request. Here are the specific requests of this form defined so far. All the ‘qXfer:OBJECT:write:...’ requests use the same reply formats, listed above. ‘qXfer:siginfo:write::OFFSET:DATA...’ Write DATA to the extra signal information on the target system. The annex part of the generic ‘qXfer’ packet must be empty (*note qXfer write::). This packet is not probed by default; the remote stub must request it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). ‘qXfer:OBJECT:OPERATION:...’ Requests of this form may be added in the future. When a stub does not recognize the OBJECT keyword, or its support for OBJECT does not recognize the OPERATION keyword, the stub must respond with an empty packet. ‘qAttached:PID’ Return an indication of whether the remote server attached to an existing process or created a new process. When the multiprocess protocol extensions are supported (*note multiprocess extensions::), PID is an integer in hexadecimal format identifying the target process. Otherwise, GDB will omit the PID field and the query packet will be simplified as ‘qAttached’. This query is used, for example, to know whether the remote process should be detached or killed when a GDB session is ended with the ‘quit’ command. Reply: ‘1’ The remote server attached to an existing process. ‘0’ The remote server created a new process. ‘Qbtrace:bts’ Enable branch tracing for the current thread using Branch Trace Store. Reply: ‘OK’ Branch tracing has been enabled. ‘Qbtrace:pt’ Enable branch tracing for the current thread using Intel Processor Trace. Reply: ‘OK’ Branch tracing has been enabled. ‘Qbtrace:off’ Disable branch tracing for the current thread. Reply: ‘OK’ Branch tracing has been disabled. ‘Qbtrace-conf:bts:size=VALUE’ Set the requested ring buffer size for new threads that use the btrace recording method in bts format. Reply: ‘OK’ The ring buffer size has been set. ‘Qbtrace-conf:pt:size=VALUE’ Set the requested ring buffer size for new threads that use the btrace recording method in pt format. Reply: ‘OK’ The ring buffer size has been set. ---------- Footnotes ---------- (1) The ‘qP’ and ‘qL’ packets predate these conventions, and have arguments without any terminator for the packet name; we suspect they are in widespread use in places that are difficult to upgrade. The ‘qC’ packet has no arguments, but some existing stubs (e.g. RedBoot) are known to not check for the end of the packet.  File: gdb.info, Node: Architecture-Specific Protocol Details, Next: Tracepoint Packets, Prev: General Query Packets, Up: Remote Protocol E.6 Architecture-Specific Protocol Details ========================================== This section describes how the remote protocol is applied to specific target architectures. Also see *note Standard Target Features::, for details of XML target descriptions for each architecture. * Menu: * ARM-Specific Protocol Details:: * MIPS-Specific Protocol Details::  File: gdb.info, Node: ARM-Specific Protocol Details, Next: MIPS-Specific Protocol Details, Up: Architecture-Specific Protocol Details E.6.1 ARM-specific Protocol Details ----------------------------------- * Menu: * ARM Breakpoint Kinds:: * ARM Memory Tag Types::  File: gdb.info, Node: ARM Breakpoint Kinds, Next: ARM Memory Tag Types, Up: ARM-Specific Protocol Details E.6.1.1 ARM Breakpoint Kinds ............................ These breakpoint kinds are defined for the ‘Z0’ and ‘Z1’ packets. 2 16-bit Thumb mode breakpoint. 3 32-bit Thumb mode (Thumb-2) breakpoint. 4 32-bit ARM mode breakpoint.  File: gdb.info, Node: ARM Memory Tag Types, Prev: ARM Breakpoint Kinds, Up: ARM-Specific Protocol Details E.6.1.2 ARM Memory Tag Types ............................ These memory tag types are defined for the ‘qMemTag’ and ‘QMemTag’ packets. 0 MTE logical tag 1 MTE allocation tag  File: gdb.info, Node: MIPS-Specific Protocol Details, Prev: ARM-Specific Protocol Details, Up: Architecture-Specific Protocol Details E.6.2 MIPS-specific Protocol Details ------------------------------------ * Menu: * MIPS Register packet Format:: * MIPS Breakpoint Kinds::  File: gdb.info, Node: MIPS Register packet Format, Next: MIPS Breakpoint Kinds, Up: MIPS-Specific Protocol Details E.6.2.1 MIPS Register Packet Format ................................... The following ‘g’/‘G’ packets have previously been defined. In the below, some thirty-two bit registers are transferred as sixty-four bits. Those registers should be zero/sign extended (which?) to fill the space allocated. Register bytes are transferred in target byte order. The two nibbles within a register byte are transferred most-significant - least-significant. MIPS32 All registers are transferred as thirty-two bit quantities in the order: 32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point registers; fsr; fir; fp. MIPS64 All registers are transferred as sixty-four bit quantities (including thirty-two bit registers such as ‘sr’). The ordering is the same as ‘MIPS32’.  File: gdb.info, Node: MIPS Breakpoint Kinds, Prev: MIPS Register packet Format, Up: MIPS-Specific Protocol Details E.6.2.2 MIPS Breakpoint Kinds ............................. These breakpoint kinds are defined for the ‘Z0’ and ‘Z1’ packets. 2 16-bit MIPS16 mode breakpoint. 3 16-bit microMIPS mode breakpoint. 4 32-bit standard MIPS mode breakpoint. 5 32-bit microMIPS mode breakpoint.  File: gdb.info, Node: Tracepoint Packets, Next: Host I/O Packets, Prev: Architecture-Specific Protocol Details, Up: Remote Protocol E.7 Tracepoint Packets ====================== Here we describe the packets GDB uses to implement tracepoints (*note Tracepoints::). ‘QTDP:N:ADDR:ENA:STEP:PASS[:FFLEN][:XLEN,BYTES][-]’ Create a new tracepoint, number N, at ADDR. If ENA is ‘E’, then the tracepoint is enabled; if it is ‘D’, then the tracepoint is disabled. The STEP gives the tracepoint's step count, and PASS gives its pass count. If an ‘F’ is present, then the tracepoint is to be a fast tracepoint, and the FLEN is the number of bytes that the target should copy elsewhere to make room for the tracepoint. If an ‘X’ is present, it introduces a tracepoint condition, which consists of a hexadecimal length, followed by a comma and hex-encoded bytes, in a manner similar to action encodings as described below. If the trailing ‘-’ is present, further ‘QTDP’ packets will follow to specify this tracepoint's actions. Replies: ‘OK’ The packet was understood and carried out. ‘qRelocInsn’ *Note Relocate instruction reply packet: Tracepoint Packets. ‘QTDP:-N:ADDR:[S]ACTION...[-]’ Define actions to be taken when a tracepoint is hit. The N and ADDR must be the same as in the initial ‘QTDP’ packet for this tracepoint. This packet may only be sent immediately after another ‘QTDP’ packet that ended with a ‘-’. If the trailing ‘-’ is present, further ‘QTDP’ packets will follow, specifying more actions for this tracepoint. In the series of action packets for a given tracepoint, at most one can have an ‘S’ before its first ACTION. If such a packet is sent, it and the following packets define "while-stepping" actions. Any prior packets define ordinary actions -- that is, those taken when the tracepoint is first hit. If no action packet has an ‘S’, then all the packets in the series specify ordinary tracepoint actions. The ‘ACTION...’ portion of the packet is a series of actions, concatenated without separators. Each action has one of the following forms: ‘R MASK’ Collect the registers whose bits are set in MASK, a hexadecimal number whose I'th bit is set if register number I should be collected. (The least significant bit is numbered zero.) Note that MASK may be any number of digits long; it may not fit in a 32-bit word. ‘M BASEREG,OFFSET,LEN’ Collect LEN bytes of memory starting at the address in register number BASEREG, plus OFFSET. If BASEREG is ‘-1’, then the range has a fixed address: OFFSET is the address of the lowest byte to collect. The BASEREG, OFFSET, and LEN parameters are all unsigned hexadecimal values (the ‘-1’ value for BASEREG is a special case). ‘X LEN,EXPR’ Evaluate EXPR, whose length is LEN, and collect memory as it directs. The agent expression EXPR is as described in *note Agent Expressions::. Each byte of the expression is encoded as a two-digit hex number in the packet; LEN is the number of bytes in the expression (and thus one-half the number of hex digits in the packet). Any number of actions may be packed together in a single ‘QTDP’ packet, as long as the packet does not exceed the maximum packet length (400 bytes, for many stubs). There may be only one ‘R’ action per tracepoint, and it must precede any ‘M’ or ‘X’ actions. Any registers referred to by ‘M’ and ‘X’ actions must be collected by a preceding ‘R’ action. (The "while-stepping" actions are treated as if they were attached to a separate tracepoint, as far as these restrictions are concerned.) Replies: ‘OK’ The packet was understood and carried out. ‘qRelocInsn’ *Note Relocate instruction reply packet: Tracepoint Packets. ‘QTDPsrc:N:ADDR:TYPE:START:SLEN:BYTES’ Specify a source string of tracepoint N at address ADDR. This is useful to get accurate reproduction of the tracepoints originally downloaded at the beginning of the trace run. The TYPE is the name of the tracepoint part, such as ‘cond’ for the tracepoint's conditional expression (see below for a list of types), while BYTES is the string, encoded in hexadecimal. START is the offset of the BYTES within the overall source string, while SLEN is the total length of the source string. This is intended for handling source strings that are longer than will fit in a single packet. The available string types are ‘at’ for the location, ‘cond’ for the conditional, and ‘cmd’ for an action command. GDB sends a separate packet for each command in the action list, in the same order in which the commands are stored in the list. The target does not need to do anything with source strings except report them back as part of the replies to the ‘qTfP’/‘qTsP’ query packets. Although this packet is optional, and GDB will only send it if the target replies with ‘TracepointSource’ *Note General Query Packets::, it makes both disconnected tracing and trace files much easier to use. Otherwise the user must be careful that the tracepoints in effect while looking at trace frames are identical to the ones in effect during the trace run; even a small discrepancy could cause ‘tdump’ not to work, or a particular trace frame not be found. ‘QTDV:N:VALUE:BUILTIN:NAME’ Create a new trace state variable, number N, with an initial value of VALUE, which is a 64-bit signed integer. Both N and VALUE are encoded as hexadecimal values. GDB has the option of not using this packet for initial values of zero; the target should simply create the trace state variables as they are mentioned in expressions. The value BUILTIN should be 1 (one) if the trace state variable is builtin and 0 (zero) if it is not builtin. GDB only sets BUILTIN to 1 if a previous ‘qTfV’ or ‘qTsV’ packet had it set. The contents of NAME is the hex-encoded name (without the leading ‘$’) of the trace state variable. ‘QTFrame:N’ Select the N'th tracepoint frame from the buffer, and use the register and memory contents recorded there to answer subsequent request packets from GDB. A successful reply from the stub indicates that the stub has found the requested frame. The response is a series of parts, concatenated without separators, describing the frame we selected. Each part has one of the following forms: ‘F F’ The selected frame is number N in the trace frame buffer; F is a hexadecimal number. If F is ‘-1’, then there was no frame matching the criteria in the request packet. ‘T T’ The selected trace frame records a hit of tracepoint number T; T is a hexadecimal number. ‘QTFrame:pc:ADDR’ Like ‘QTFrame:N’, but select the first tracepoint frame after the currently selected frame whose PC is ADDR; ADDR is a hexadecimal number. ‘QTFrame:tdp:T’ Like ‘QTFrame:N’, but select the first tracepoint frame after the currently selected frame that is a hit of tracepoint T; T is a hexadecimal number. ‘QTFrame:range:START:END’ Like ‘QTFrame:N’, but select the first tracepoint frame after the currently selected frame whose PC is between START (inclusive) and END (inclusive); START and END are hexadecimal numbers. ‘QTFrame:outside:START:END’ Like ‘QTFrame:range:START:END’, but select the first frame _outside_ the given range of addresses (exclusive). ‘qTMinFTPILen’ This packet requests the minimum length of instruction at which a fast tracepoint (*note Set Tracepoints::) may be placed. For instance, on the 32-bit x86 architecture, it is possible to use a 4-byte jump, but it depends on the target system being able to create trampolines in the first 64K of memory, which might or might not be possible for that system. So the reply to this packet will be 4 if it is able to arrange for that. Replies: ‘0’ The minimum instruction length is currently unknown. ‘LENGTH’ The minimum instruction length is LENGTH, where LENGTH is a hexadecimal number greater or equal to 1. A reply of 1 means that a fast tracepoint may be placed on any instruction regardless of size. ‘E’ An error has occurred. ‘QTStart’ Begin the tracepoint experiment. Begin collecting data from tracepoint hits in the trace frame buffer. This packet supports the ‘qRelocInsn’ reply (*note Relocate instruction reply packet: Tracepoint Packets.). ‘QTStop’ End the tracepoint experiment. Stop collecting trace frames. ‘QTEnable:N:ADDR’ Enable tracepoint N at address ADDR in a started tracepoint experiment. If the tracepoint was previously disabled, then collection of data from it will resume. ‘QTDisable:N:ADDR’ Disable tracepoint N at address ADDR in a started tracepoint experiment. No more data will be collected from the tracepoint unless ‘QTEnable:N:ADDR’ is subsequently issued. ‘QTinit’ Clear the table of tracepoints, and empty the trace frame buffer. ‘QTro:START1,END1:START2,END2:...’ Establish the given ranges of memory as "transparent". The stub will answer requests for these ranges from memory's current contents, if they were not collected as part of the tracepoint hit. GDB uses this to mark read-only regions of memory, like those containing program code. Since these areas never change, they should still have the same contents they did when the tracepoint was hit, so there's no reason for the stub to refuse to provide their contents. ‘QTDisconnected:VALUE’ Set the choice to what to do with the tracing run when GDB disconnects from the target. A VALUE of 1 directs the target to continue the tracing run, while 0 tells the target to stop tracing if GDB is no longer in the picture. ‘qTStatus’ Ask the stub if there is a trace experiment running right now. The reply has the form: ‘TRUNNING[;FIELD]...’ RUNNING is a single digit ‘1’ if the trace is presently running, or ‘0’ if not. It is followed by semicolon-separated optional fields that an agent may use to report additional status. If the trace is not running, the agent may report any of several explanations as one of the optional fields: ‘tnotrun:0’ No trace has been run yet. ‘tstop[:TEXT]:0’ The trace was stopped by a user-originated stop command. The optional TEXT field is a user-supplied string supplied as part of the stop command (for instance, an explanation of why the trace was stopped manually). It is hex-encoded. ‘tfull:0’ The trace stopped because the trace buffer filled up. ‘tdisconnected:0’ The trace stopped because GDB disconnected from the target. ‘tpasscount:TPNUM’ The trace stopped because tracepoint TPNUM exceeded its pass count. ‘terror:TEXT:TPNUM’ The trace stopped because tracepoint TPNUM had an error. The string TEXT is available to describe the nature of the error (for instance, a divide by zero in the condition expression); it is hex encoded. ‘tunknown:0’ The trace stopped for some other reason. Additional optional fields supply statistical and other information. Although not required, they are extremely useful for users monitoring the progress of a trace run. If a trace has stopped, and these numbers are reported, they must reflect the state of the just-stopped trace. ‘tframes:N’ The number of trace frames in the buffer. ‘tcreated:N’ The total number of trace frames created during the run. This may be larger than the trace frame count, if the buffer is circular. ‘tsize:N’ The total size of the trace buffer, in bytes. ‘tfree:N’ The number of bytes still unused in the buffer. ‘circular:N’ The value of the circular trace buffer flag. ‘1’ means that the trace buffer is circular and old trace frames will be discarded if necessary to make room, ‘0’ means that the trace buffer is linear and may fill up. ‘disconn:N’ The value of the disconnected tracing flag. ‘1’ means that tracing will continue after GDB disconnects, ‘0’ means that the trace run will stop. ‘qTP:TP:ADDR’ Ask the stub for the current state of tracepoint number TP at address ADDR. Replies: ‘VHITS:USAGE’ The tracepoint has been hit HITS times so far during the trace run, and accounts for USAGE in the trace buffer. Note that ‘while-stepping’ steps are not counted as separate hits, but the steps' space consumption is added into the usage number. ‘qTV:VAR’ Ask the stub for the value of the trace state variable number VAR. Replies: ‘VVALUE’ The value of the variable is VALUE. This will be the current value of the variable if the user is examining a running target, or a saved value if the variable was collected in the trace frame that the user is looking at. Note that multiple requests may result in different reply values, such as when requesting values while the program is running. ‘U’ The value of the variable is unknown. This would occur, for example, if the user is examining a trace frame in which the requested variable was not collected. ‘qTfP’ ‘qTsP’ These packets request data about tracepoints that are being used by the target. GDB sends ‘qTfP’ to get the first piece of data, and multiple ‘qTsP’ to get additional pieces. Replies to these packets generally take the form of the ‘QTDP’ packets that define tracepoints. (FIXME add detailed syntax) ‘qTfV’ ‘qTsV’ These packets request data about trace state variables that are on the target. GDB sends ‘qTfV’ to get the first vari of data, and multiple ‘qTsV’ to get additional variables. Replies to these packets follow the syntax of the ‘QTDV’ packets that define trace state variables. ‘qTfSTM’ ‘qTsSTM’ These packets request data about static tracepoint markers that exist in the target program. GDB sends ‘qTfSTM’ to get the first piece of data, and multiple ‘qTsSTM’ to get additional pieces. Replies to these packets take the following form: Reply: ‘m ADDRESS:ID:EXTRA’ A single marker ‘m ADDRESS:ID:EXTRA,ADDRESS:ID:EXTRA...’ a comma-separated list of markers ‘l’ (lower case letter ‘L’) denotes end of list. The ADDRESS is encoded in hex; ID and EXTRA are strings encoded in hex. In response to each query, the target will reply with a list of one or more markers, separated by commas. GDB will respond to each reply with a request for more markers (using the ‘qs’ form of the query), until the target responds with ‘l’ (lower-case ell, for “last”). ‘qTSTMat:ADDRESS’ This packets requests data about static tracepoint markers in the target program at ADDRESS. Replies to this packet follow the syntax of the ‘qTfSTM’ and ‘qTsSTM’ packets that list static tracepoint markers. ‘QTSave:FILENAME’ This packet directs the target to save trace data to the file name FILENAME in the target's filesystem. The FILENAME is encoded as a hex string; the interpretation of the file name (relative vs absolute, wild cards, etc) is up to the target. ‘qTBuffer:OFFSET,LEN’ Return up to LEN bytes of the current contents of trace buffer, starting at OFFSET. The trace buffer is treated as if it were a contiguous collection of traceframes, as per the trace file format. The reply consists as many hex-encoded bytes as the target can deliver in a packet; it is not an error to return fewer than were asked for. A reply consisting of just ‘l’ indicates that no bytes are available. ‘QTBuffer:circular:VALUE’ This packet directs the target to use a circular trace buffer if VALUE is 1, or a linear buffer if the value is 0. ‘QTBuffer:size:SIZE’ This packet directs the target to make the trace buffer be of size SIZE if possible. A value of ‘-1’ tells the target to use whatever size it prefers. ‘QTNotes:[TYPE:TEXT][;TYPE:TEXT]...’ This packet adds optional textual notes to the trace run. Allowable types include ‘user’, ‘notes’, and ‘tstop’, the TEXT fields are arbitrary strings, hex-encoded. E.7.1 Relocate instruction reply packet --------------------------------------- When installing fast tracepoints in memory, the target may need to relocate the instruction currently at the tracepoint address to a different address in memory. For most instructions, a simple copy is enough, but, for example, call instructions that implicitly push the return address on the stack, and relative branches or other PC-relative instructions require offset adjustment, so that the effect of executing the instruction at a different address is the same as if it had executed in the original location. In response to several of the tracepoint packets, the target may also respond with a number of intermediate ‘qRelocInsn’ request packets before the final result packet, to have GDB handle this relocation operation. If a packet supports this mechanism, its documentation will explicitly say so. See for example the above descriptions for the ‘QTStart’ and ‘QTDP’ packets. The format of the request is: ‘qRelocInsn:FROM;TO’ This requests GDB to copy instruction at address FROM to address TO, possibly adjusted so that executing the instruction at TO has the same effect as executing it at FROM. GDB writes the adjusted instruction to target memory starting at TO. Replies: ‘qRelocInsn:ADJUSTED_SIZE’ Informs the stub the relocation is complete. The ADJUSTED_SIZE is the length in bytes of resulting relocated instruction sequence.  File: gdb.info, Node: Host I/O Packets, Next: Interrupts, Prev: Tracepoint Packets, Up: Remote Protocol E.8 Host I/O Packets ==================== The “Host I/O” packets allow GDB to perform I/O operations on the far side of a remote link. For example, Host I/O is used to upload and download files to a remote target with its own filesystem. Host I/O uses the same constant values and data structure layout as the target-initiated File-I/O protocol. However, the Host I/O packets are structured differently. The target-initiated protocol relies on target memory to store parameters and buffers. Host I/O requests are initiated by GDB, and the target's memory is not involved. *Note File-I/O Remote Protocol Extension::, for more details on the target-initiated protocol. The Host I/O request packets all encode a single operation along with its arguments. They have this format: ‘vFile:OPERATION: PARAMETER...’ OPERATION is the name of the particular request; the target should compare the entire packet name up to the second colon when checking for a supported operation. The format of PARAMETER depends on the operation. Numbers are always passed in hexadecimal. Negative numbers have an explicit minus sign (i.e. two's complement is not used). Strings (e.g. filenames) are encoded as a series of hexadecimal bytes. The last argument to a system call may be a buffer of escaped binary data (*note Binary Data::). The valid responses to Host I/O packets are: ‘F RESULT [, ERRNO] [; ATTACHMENT]’ RESULT is the integer value returned by this operation, usually non-negative for success and -1 for errors. If an error has occurred, ERRNO will be included in the result specifying a value defined by the File-I/O protocol (*note Errno Values::). For operations which return data, ATTACHMENT supplies the data as a binary buffer. Binary buffers in response packets are escaped in the normal way (*note Binary Data::). See the individual packet documentation for the interpretation of RESULT and ATTACHMENT. ‘’ An empty response indicates that this operation is not recognized. These are the supported Host I/O operations: ‘vFile:open: FILENAME, FLAGS, MODE’ Open a file at FILENAME and return a file descriptor for it, or return -1 if an error occurs. The FILENAME is a string, FLAGS is an integer indicating a mask of open flags (*note Open Flags::), and MODE is an integer indicating a mask of mode bits to use if the file is created (*note mode_t Values::). *Note open::, for details of the open flags and mode values. ‘vFile:close: FD’ Close the open file corresponding to FD and return 0, or -1 if an error occurs. ‘vFile:pread: FD, COUNT, OFFSET’ Read data from the open file corresponding to FD. Up to COUNT bytes will be read from the file, starting at OFFSET relative to the start of the file. The target may read fewer bytes; common reasons include packet size limits and an end-of-file condition. The number of bytes read is returned. Zero should only be returned for a successful read at the end of the file, or if COUNT was zero. The data read should be returned as a binary attachment on success. If zero bytes were read, the response should include an empty binary attachment (i.e. a trailing semicolon). The return value is the number of target bytes read; the binary attachment may be longer if some characters were escaped. ‘vFile:pwrite: FD, OFFSET, DATA’ Write DATA (a binary buffer) to the open file corresponding to FD. Start the write at OFFSET from the start of the file. Unlike many ‘write’ system calls, there is no separate COUNT argument; the length of DATA in the packet is used. ‘vFile:pwrite’ returns the number of bytes written, which may be shorter than the length of DATA, or -1 if an error occurred. ‘vFile:fstat: FD’ Get information about the open file corresponding to FD. On success the information is returned as a binary attachment and the return value is the size of this attachment in bytes. If an error occurs the return value is -1. The format of the returned binary attachment is as described in *note struct stat::. ‘vFile:unlink: FILENAME’ Delete the file at FILENAME on the target. Return 0, or -1 if an error occurs. The FILENAME is a string. ‘vFile:readlink: FILENAME’ Read value of symbolic link FILENAME on the target. Return the number of bytes read, or -1 if an error occurs. The data read should be returned as a binary attachment on success. If zero bytes were read, the response should include an empty binary attachment (i.e. a trailing semicolon). The return value is the number of target bytes read; the binary attachment may be longer if some characters were escaped. ‘vFile:setfs: PID’ Select the filesystem on which ‘vFile’ operations with FILENAME arguments will operate. This is required for GDB to be able to access files on remote targets where the remote stub does not share a common filesystem with the inferior(s). If PID is nonzero, select the filesystem as seen by process PID. If PID is zero, select the filesystem as seen by the remote stub. Return 0 on success, or -1 if an error occurs. If ‘vFile:setfs:’ indicates success, the selected filesystem remains selected until the next successful ‘vFile:setfs:’ operation.  File: gdb.info, Node: Interrupts, Next: Notification Packets, Prev: Host I/O Packets, Up: Remote Protocol E.9 Interrupts ============== In all-stop mode, when a program on the remote target is running, GDB may attempt to interrupt it by sending a ‘Ctrl-C’, ‘BREAK’ or a ‘BREAK’ followed by ‘g’, control of which is specified via GDB's ‘interrupt-sequence’. The precise meaning of ‘BREAK’ is defined by the transport mechanism and may, in fact, be undefined. GDB does not currently define a ‘BREAK’ mechanism for any of the network interfaces except for TCP, in which case GDB sends the ‘telnet’ BREAK sequence. ‘Ctrl-C’, on the other hand, is defined and implemented for all transport mechanisms. It is represented by sending the single byte ‘0x03’ without any of the usual packet overhead described in the Overview section (*note Overview::). When a ‘0x03’ byte is transmitted as part of a packet, it is considered to be packet data and does _not_ represent an interrupt. E.g., an ‘X’ packet (*note X packet::), used for binary downloads, may include an unescaped ‘0x03’ as part of its packet. ‘BREAK’ followed by ‘g’ is also known as Magic SysRq g. When Linux kernel receives this sequence from serial port, it stops execution and connects to gdb. In non-stop mode, because packet resumptions are asynchronous (*note vCont packet::), GDB is always free to send a remote command to the remote stub, even when the target is running. For that reason, GDB instead sends a regular packet (*note vCtrlC packet::) with the usual packet framing instead of the single byte ‘0x03’. Stubs are not required to recognize these interrupt mechanisms and the precise meaning associated with receipt of the interrupt is implementation defined. If the target supports debugging of multiple threads and/or processes, it should attempt to interrupt all currently-executing threads and processes. If the stub is successful at interrupting the running program, it should send one of the stop reply packets (*note Stop Reply Packets::) to GDB as a result of successfully stopping the program in all-stop mode, and a stop reply for each stopped thread in non-stop mode. Interrupts received while the program is stopped are queued and the program will be interrupted when it is resumed next time.  File: gdb.info, Node: Notification Packets, Next: Remote Non-Stop, Prev: Interrupts, Up: Remote Protocol E.10 Notification Packets ========================= The GDB remote serial protocol includes “notifications”, packets that require no acknowledgment. Both the GDB and the stub may send notifications (although the only notifications defined at present are sent by the stub). Notifications carry information without incurring the round-trip latency of an acknowledgment, and so are useful for low-impact communications where occasional packet loss is not a problem. A notification packet has the form ‘% DATA # CHECKSUM’, where DATA is the content of the notification, and CHECKSUM is a checksum of DATA, computed and formatted as for ordinary GDB packets. A notification's DATA never contains ‘$’, ‘%’ or ‘#’ characters. Upon receiving a notification, the recipient sends no ‘+’ or ‘-’ to acknowledge the notification's receipt or to report its corruption. Every notification's DATA begins with a name, which contains no colon characters, followed by a colon character. Recipients should silently ignore corrupted notifications and notifications they do not understand. Recipients should restart timeout periods on receipt of a well-formed notification, whether or not they understand it. Senders should only send the notifications described here when this protocol description specifies that they are permitted. In the future, we may extend the protocol to permit existing notifications in new contexts; this rule helps older senders avoid confusing newer recipients. (Older versions of GDB ignore bytes received until they see the ‘$’ byte that begins an ordinary packet, so new stubs may transmit notifications without fear of confusing older clients. There are no notifications defined for GDB to send at the moment, but we assume that most older stubs would ignore them, as well.) Each notification is comprised of three parts: ‘NAME:EVENT’ The notification packet is sent by the side that initiates the exchange (currently, only the stub does that), with EVENT carrying the specific information about the notification, and NAME specifying the name of the notification. ‘ACK’ The acknowledge sent by the other side, usually GDB, to acknowledge the exchange and request the event. The purpose of an asynchronous notification mechanism is to report to GDB that something interesting happened in the remote stub. The remote stub may send notification NAME:EVENT at any time, but GDB acknowledges the notification when appropriate. The notification event is pending before GDB acknowledges. Only one notification at a time may be pending; if additional events occur before GDB has acknowledged the previous notification, they must be queued by the stub for later synchronous transmission in response to ACK packets from GDB. Because the notification mechanism is unreliable, the stub is permitted to resend a notification if it believes GDB may not have received it. Specifically, notifications may appear when GDB is not otherwise reading input from the stub, or when GDB is expecting to read a normal synchronous response or a ‘+’/‘-’ acknowledgment to a packet it has sent. Notification packets are distinct from any other communication from the stub so there is no ambiguity. After receiving a notification, GDB shall acknowledge it by sending a ACK packet as a regular, synchronous request to the stub. Such acknowledgment is not required to happen immediately, as GDB is permitted to send other, unrelated packets to the stub first, which the stub should process normally. Upon receiving a ACK packet, if the stub has other queued events to report to GDB, it shall respond by sending a normal EVENT. GDB shall then send another ACK packet to solicit further responses; again, it is permitted to send other, unrelated packets as well which the stub should process normally. If the stub receives a ACK packet and there are no additional EVENT to report, the stub shall return an ‘OK’ response. At this point, GDB has finished processing a notification and the stub has completed sending any queued events. GDB won't accept any new notifications until the final ‘OK’ is received . If further notification events occur, the stub shall send a new notification, GDB shall accept the notification, and the process shall be repeated. The process of asynchronous notification can be illustrated by the following example: <- %Stop:T0505:98e7ffbf;04:4ce6ffbf;08:b1b6e54c;thread:p7526.7526;core:0; ... -> vStopped <- T0505:68f37db7;04:40f37db7;08:63850408;thread:p7526.7528;core:0; -> vStopped <- T0505:68e3fdb6;04:40e3fdb6;08:63850408;thread:p7526.7529;core:0; -> vStopped <- OK The following notifications are defined: NotificationAck Event Description Stop vStopped REPLY. The REPLY has the Report an asynchronous form of a stop reply, as stop event in non-stop described in mode. *note Stop Reply Packets::. Refer to *note Remote Non-Stop::, for information on how these notifications are acknowledged by GDB.  File: gdb.info, Node: Remote Non-Stop, Next: Packet Acknowledgment, Prev: Notification Packets, Up: Remote Protocol E.11 Remote Protocol Support for Non-Stop Mode ============================================== GDB's remote protocol supports non-stop debugging of multi-threaded programs, as described in *note Non-Stop Mode::. If the stub supports non-stop mode, it should report that to GDB by including ‘QNonStop+’ in its ‘qSupported’ response (*note qSupported::). GDB typically sends a ‘QNonStop’ packet only when establishing a new connection with the stub. Entering non-stop mode does not alter the state of any currently-running threads, but targets must stop all threads in any already-attached processes when entering all-stop mode. GDB uses the ‘?’ packet as necessary to probe the target state after a mode change. In non-stop mode, when an attached process encounters an event that would otherwise be reported with a stop reply, it uses the asynchronous notification mechanism (*note Notification Packets::) to inform GDB. In contrast to all-stop mode, where all threads in all processes are stopped when a stop reply is sent, in non-stop mode only the thread reporting the stop event is stopped. That is, when reporting a ‘S’ or ‘T’ response to indicate completion of a step operation, hitting a breakpoint, or a fault, only the affected thread is stopped; any other still-running threads continue to run. When reporting a ‘W’ or ‘X’ response, all running threads belonging to other attached processes continue to run. In non-stop mode, the target shall respond to the ‘?’ packet as follows. First, any incomplete stop reply notification/‘vStopped’ sequence in progress is abandoned. The target must begin a new sequence reporting stop events for all stopped threads, whether or not it has previously reported those events to GDB. The first stop reply is sent as a synchronous reply to the ‘?’ packet, and subsequent stop replies are sent as responses to ‘vStopped’ packets using the mechanism described above. The target must not send asynchronous stop reply notifications until the sequence is complete. If all threads are running when the target receives the ‘?’ packet, or if the target is not attached to any process, it shall respond ‘OK’. If the stub supports non-stop mode, it should also support the ‘swbreak’ stop reason if software breakpoints are supported, and the ‘hwbreak’ stop reason if hardware breakpoints are supported (*note swbreak stop reason::). This is because given the asynchronous nature of non-stop mode, between the time a thread hits a breakpoint and the time the event is finally processed by GDB, the breakpoint may have already been removed from the target. Due to this, GDB needs to be able to tell whether a trap stop was caused by a delayed breakpoint event, which should be ignored, as opposed to a random trap signal, which should be reported to the user. Note the ‘swbreak’ feature implies that the target is responsible for adjusting the PC when a software breakpoint triggers, if necessary, such as on the x86 architecture.  File: gdb.info, Node: Packet Acknowledgment, Next: Examples, Prev: Remote Non-Stop, Up: Remote Protocol E.12 Packet Acknowledgment ========================== By default, when either the host or the target machine receives a packet, the first response expected is an acknowledgment: either ‘+’ (to indicate the package was received correctly) or ‘-’ (to request retransmission). This mechanism allows the GDB remote protocol to operate over unreliable transport mechanisms, such as a serial line. In cases where the transport mechanism is itself reliable (such as a pipe or TCP connection), the ‘+’/‘-’ acknowledgments are redundant. It may be desirable to disable them in that case to reduce communication overhead, or for other reasons. This can be accomplished by means of the ‘QStartNoAckMode’ packet; *note QStartNoAckMode::. When in no-acknowledgment mode, neither the stub nor GDB shall send or expect ‘+’/‘-’ protocol acknowledgments. The packet and response format still includes the normal checksum, as described in *note Overview::, but the checksum may be ignored by the receiver. If the stub supports ‘QStartNoAckMode’ and prefers to operate in no-acknowledgment mode, it should report that to GDB by including ‘QStartNoAckMode+’ in its response to ‘qSupported’; *note qSupported::. If GDB also supports ‘QStartNoAckMode’ and it has not been disabled via the ‘set remote noack-packet off’ command (*note Remote Configuration::), GDB may then send a ‘QStartNoAckMode’ packet to the stub. Only then may the stub actually turn off packet acknowledgments. GDB sends a final ‘+’ acknowledgment of the stub's ‘OK’ response, which can be safely ignored by the stub. Note that ‘set remote noack-packet’ command only affects negotiation between GDB and the stub when subsequent connections are made; it does not affect the protocol acknowledgment state for any current connection. Since ‘+’/‘-’ acknowledgments are enabled by default when a new connection is established, there is also no protocol request to re-enable the acknowledgments for the current connection, once disabled.  File: gdb.info, Node: Examples, Next: File-I/O Remote Protocol Extension, Prev: Packet Acknowledgment, Up: Remote Protocol E.13 Examples ============= Example sequence of a target being re-started. Notice how the restart does not get any direct output: -> R00 <- + _target restarts_ -> ? <- + <- T001:1234123412341234 -> + Example sequence of a target being stepped by a single instruction: -> G1445... <- + -> s <- + _time passes_ <- T001:1234123412341234 -> + -> g <- + <- 1455... -> +  File: gdb.info, Node: File-I/O Remote Protocol Extension, Next: Library List Format, Prev: Examples, Up: Remote Protocol E.14 File-I/O Remote Protocol Extension ======================================= * Menu: * File-I/O Overview:: * Protocol Basics:: * The F Request Packet:: * The F Reply Packet:: * The Ctrl-C Message:: * Console I/O:: * List of Supported Calls:: * Protocol-specific Representation of Datatypes:: * Constants:: * File-I/O Examples::  File: gdb.info, Node: File-I/O Overview, Next: Protocol Basics, Up: File-I/O Remote Protocol Extension E.14.1 File-I/O Overview ------------------------ The “File I/O remote protocol extension” (short: File-I/O) allows the target to use the host's file system and console I/O to perform various system calls. System calls on the target system are translated into a remote protocol packet to the host system, which then performs the needed actions and returns a response packet to the target system. This simulates file system operations even on targets that lack file systems. The protocol is defined to be independent of both the host and target systems. It uses its own internal representation of datatypes and values. Both GDB and the target's GDB stub are responsible for translating the system-dependent value representations into the internal protocol representations when data is transmitted. The communication is synchronous. A system call is possible only when GDB is waiting for a response from the ‘C’, ‘c’, ‘S’ or ‘s’ packets. While GDB handles the request for a system call, the target is stopped to allow deterministic access to the target's memory. Therefore File-I/O is not interruptible by target signals. On the other hand, it is possible to interrupt File-I/O by a user interrupt (‘Ctrl-C’) within GDB. The target's request to perform a host system call does not finish the latest ‘C’, ‘c’, ‘S’ or ‘s’ action. That means, after finishing the system call, the target returns to continuing the previous activity (continue, step). No additional continue or step request from GDB is required. (gdb) continue <- target requests 'system call X' target is stopped, GDB executes system call -> GDB returns result ... target continues, GDB returns to wait for the target <- target hits breakpoint and sends a Txx packet The protocol only supports I/O on the console and to regular files on the host file system. Character or block special devices, pipes, named pipes, sockets or any other communication method on the host system are not supported by this protocol. File I/O is not supported in non-stop mode.  File: gdb.info, Node: Protocol Basics, Next: The F Request Packet, Prev: File-I/O Overview, Up: File-I/O Remote Protocol Extension E.14.2 Protocol Basics ---------------------- The File-I/O protocol uses the ‘F’ packet as the request as well as reply packet. Since a File-I/O system call can only occur when GDB is waiting for a response from the continuing or stepping target, the File-I/O request is a reply that GDB has to expect as a result of a previous ‘C’, ‘c’, ‘S’ or ‘s’ packet. This ‘F’ packet contains all information needed to allow GDB to call the appropriate host system call: • A unique identifier for the requested system call. • All parameters to the system call. Pointers are given as addresses in the target memory address space. Pointers to strings are given as pointer/length pair. Numerical values are given as they are. Numerical control flags are given in a protocol-specific representation. At this point, GDB has to perform the following actions. • If the parameters include pointer values to data needed as input to a system call, GDB requests this data from the target with a standard ‘m’ packet request. This additional communication has to be expected by the target implementation and is handled as any other ‘m’ packet. • GDB translates all value from protocol representation to host representation as needed. Datatypes are coerced into the host types. • GDB calls the system call. • It then coerces datatypes back to protocol representation. • If the system call is expected to return data in buffer space specified by pointer parameters to the call, the data is transmitted to the target using a ‘M’ or ‘X’ packet. This packet has to be expected by the target implementation and is handled as any other ‘M’ or ‘X’ packet. Eventually GDB replies with another ‘F’ packet which contains all necessary information for the target to continue. This at least contains • Return value. • ‘errno’, if has been changed by the system call. • "Ctrl-C" flag. After having done the needed type and value coercion, the target continues the latest continue or step action.  File: gdb.info, Node: The F Request Packet, Next: The F Reply Packet, Prev: Protocol Basics, Up: File-I/O Remote Protocol Extension E.14.3 The ‘F’ Request Packet ----------------------------- The ‘F’ request packet has the following format: ‘FCALL-ID,PARAMETER...’ CALL-ID is the identifier to indicate the host system call to be called. This is just the name of the function. PARAMETER... are the parameters to the system call. Parameters are hexadecimal integer values, either the actual values in case of scalar datatypes, pointers to target buffer space in case of compound datatypes and unspecified memory areas, or pointer/length pairs in case of string parameters. These are appended to the CALL-ID as a comma-delimited list. All values are transmitted in ASCII string representation, pointer/length pairs separated by a slash.  File: gdb.info, Node: The F Reply Packet, Next: The Ctrl-C Message, Prev: The F Request Packet, Up: File-I/O Remote Protocol Extension E.14.4 The ‘F’ Reply Packet --------------------------- The ‘F’ reply packet has the following format: ‘FRETCODE,ERRNO,CTRL-C FLAG;CALL-SPECIFIC ATTACHMENT’ RETCODE is the return code of the system call as hexadecimal value. ERRNO is the ‘errno’ set by the call, in protocol-specific representation. This parameter can be omitted if the call was successful. CTRL-C FLAG is only sent if the user requested a break. In this case, ERRNO must be sent as well, even if the call was successful. The CTRL-C FLAG itself consists of the character ‘C’: F0,0,C or, if the call was interrupted before the host call has been performed: F-1,4,C assuming 4 is the protocol-specific representation of ‘EINTR’.  File: gdb.info, Node: The Ctrl-C Message, Next: Console I/O, Prev: The F Reply Packet, Up: File-I/O Remote Protocol Extension E.14.5 The ‘Ctrl-C’ Message --------------------------- If the ‘Ctrl-C’ flag is set in the GDB reply packet (*note The F Reply Packet::), the target should behave as if it had gotten a break message. The meaning for the target is "system call interrupted by ‘SIGINT’". Consequently, the target should actually stop (as with a break message) and return to GDB with a ‘T02’ packet. It's important for the target to know in which state the system call was interrupted. There are two possible cases: • The system call hasn't been performed on the host yet. • The system call on the host has been finished. These two states can be distinguished by the target by the value of the returned ‘errno’. If it's the protocol representation of ‘EINTR’, the system call hasn't been performed. This is equivalent to the ‘EINTR’ handling on POSIX systems. In any other case, the target may presume that the system call has been finished -- successfully or not -- and should behave as if the break message arrived right after the system call. GDB must behave reliably. If the system call has not been called yet, GDB may send the ‘F’ reply immediately, setting ‘EINTR’ as ‘errno’ in the packet. If the system call on the host has been finished before the user requests a break, the full action must be finished by GDB. This requires sending ‘M’ or ‘X’ packets as necessary. The ‘F’ packet may only be sent when either nothing has happened or the full action has been completed.  File: gdb.info, Node: Console I/O, Next: List of Supported Calls, Prev: The Ctrl-C Message, Up: File-I/O Remote Protocol Extension E.14.6 Console I/O ------------------ By default and if not explicitly closed by the target system, the file descriptors 0, 1 and 2 are connected to the GDB console. Output on the GDB console is handled as any other file output operation (‘write(1, ...)’ or ‘write(2, ...)’). Console input is handled by GDB so that after the target read request from file descriptor 0 all following typing is buffered until either one of the following conditions is met: • The user types ‘Ctrl-c’. The behaviour is as explained above, and the ‘read’ system call is treated as finished. • The user presses . This is treated as end of input with a trailing newline. • The user types ‘Ctrl-d’. This is treated as end of input. No trailing character (neither newline nor ‘Ctrl-D’) is appended to the input. If the user has typed more characters than fit in the buffer given to the ‘read’ call, the trailing characters are buffered in GDB until either another ‘read(0, ...)’ is requested by the target, or debugging is stopped at the user's request.  File: gdb.info, Node: List of Supported Calls, Next: Protocol-specific Representation of Datatypes, Prev: Console I/O, Up: File-I/O Remote Protocol Extension E.14.7 List of Supported Calls ------------------------------ * Menu: * open:: * close:: * read:: * write:: * lseek:: * rename:: * unlink:: * stat/fstat:: * gettimeofday:: * isatty:: * system::  File: gdb.info, Node: open, Next: close, Up: List of Supported Calls open .... Synopsis: int open(const char *pathname, int flags); int open(const char *pathname, int flags, mode_t mode); Request: ‘Fopen,PATHPTR/LEN,FLAGS,MODE’ FLAGS is the bitwise ‘OR’ of the following values: ‘O_CREAT’ If the file does not exist it will be created. The host rules apply as far as file ownership and time stamps are concerned. ‘O_EXCL’ When used with ‘O_CREAT’, if the file already exists it is an error and open() fails. ‘O_TRUNC’ If the file already exists and the open mode allows writing (‘O_RDWR’ or ‘O_WRONLY’ is given) it will be truncated to zero length. ‘O_APPEND’ The file is opened in append mode. ‘O_RDONLY’ The file is opened for reading only. ‘O_WRONLY’ The file is opened for writing only. ‘O_RDWR’ The file is opened for reading and writing. Other bits are silently ignored. MODE is the bitwise ‘OR’ of the following values: ‘S_IRUSR’ User has read permission. ‘S_IWUSR’ User has write permission. ‘S_IRGRP’ Group has read permission. ‘S_IWGRP’ Group has write permission. ‘S_IROTH’ Others have read permission. ‘S_IWOTH’ Others have write permission. Other bits are silently ignored. Return value: ‘open’ returns the new file descriptor or -1 if an error occurred. Errors: ‘EEXIST’ PATHNAME already exists and ‘O_CREAT’ and ‘O_EXCL’ were used. ‘EISDIR’ PATHNAME refers to a directory. ‘EACCES’ The requested access is not allowed. ‘ENAMETOOLONG’ PATHNAME was too long. ‘ENOENT’ A directory component in PATHNAME does not exist. ‘ENODEV’ PATHNAME refers to a device, pipe, named pipe or socket. ‘EROFS’ PATHNAME refers to a file on a read-only filesystem and write access was requested. ‘EFAULT’ PATHNAME is an invalid pointer value. ‘ENOSPC’ No space on device to create the file. ‘EMFILE’ The process already has the maximum number of files open. ‘ENFILE’ The limit on the total number of files open on the system has been reached. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: close, Next: read, Prev: open, Up: List of Supported Calls close ..... Synopsis: int close(int fd); Request: ‘Fclose,FD’ Return value: ‘close’ returns zero on success, or -1 if an error occurred. Errors: ‘EBADF’ FD isn't a valid open file descriptor. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: read, Next: write, Prev: close, Up: List of Supported Calls read .... Synopsis: int read(int fd, void *buf, unsigned int count); Request: ‘Fread,FD,BUFPTR,COUNT’ Return value: On success, the number of bytes read is returned. Zero indicates end of file. If count is zero, read returns zero as well. On error, -1 is returned. Errors: ‘EBADF’ FD is not a valid file descriptor or is not open for reading. ‘EFAULT’ BUFPTR is an invalid pointer value. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: write, Next: lseek, Prev: read, Up: List of Supported Calls write ..... Synopsis: int write(int fd, const void *buf, unsigned int count); Request: ‘Fwrite,FD,BUFPTR,COUNT’ Return value: On success, the number of bytes written are returned. Zero indicates nothing was written. On error, -1 is returned. Errors: ‘EBADF’ FD is not a valid file descriptor or is not open for writing. ‘EFAULT’ BUFPTR is an invalid pointer value. ‘EFBIG’ An attempt was made to write a file that exceeds the host-specific maximum file size allowed. ‘ENOSPC’ No space on device to write the data. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: lseek, Next: rename, Prev: write, Up: List of Supported Calls lseek ..... Synopsis: long lseek (int fd, long offset, int flag); Request: ‘Flseek,FD,OFFSET,FLAG’ FLAG is one of: ‘SEEK_SET’ The offset is set to OFFSET bytes. ‘SEEK_CUR’ The offset is set to its current location plus OFFSET bytes. ‘SEEK_END’ The offset is set to the size of the file plus OFFSET bytes. Return value: On success, the resulting unsigned offset in bytes from the beginning of the file is returned. Otherwise, a value of -1 is returned. Errors: ‘EBADF’ FD is not a valid open file descriptor. ‘ESPIPE’ FD is associated with the GDB console. ‘EINVAL’ FLAG is not a proper value. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: rename, Next: unlink, Prev: lseek, Up: List of Supported Calls rename ...... Synopsis: int rename(const char *oldpath, const char *newpath); Request: ‘Frename,OLDPATHPTR/LEN,NEWPATHPTR/LEN’ Return value: On success, zero is returned. On error, -1 is returned. Errors: ‘EISDIR’ NEWPATH is an existing directory, but OLDPATH is not a directory. ‘EEXIST’ NEWPATH is a non-empty directory. ‘EBUSY’ OLDPATH or NEWPATH is a directory that is in use by some process. ‘EINVAL’ An attempt was made to make a directory a subdirectory of itself. ‘ENOTDIR’ A component used as a directory in OLDPATH or new path is not a directory. Or OLDPATH is a directory and NEWPATH exists but is not a directory. ‘EFAULT’ OLDPATHPTR or NEWPATHPTR are invalid pointer values. ‘EACCES’ No access to the file or the path of the file. ‘ENAMETOOLONG’ OLDPATH or NEWPATH was too long. ‘ENOENT’ A directory component in OLDPATH or NEWPATH does not exist. ‘EROFS’ The file is on a read-only filesystem. ‘ENOSPC’ The device containing the file has no room for the new directory entry. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: unlink, Next: stat/fstat, Prev: rename, Up: List of Supported Calls unlink ...... Synopsis: int unlink(const char *pathname); Request: ‘Funlink,PATHNAMEPTR/LEN’ Return value: On success, zero is returned. On error, -1 is returned. Errors: ‘EACCES’ No access to the file or the path of the file. ‘EPERM’ The system does not allow unlinking of directories. ‘EBUSY’ The file PATHNAME cannot be unlinked because it's being used by another process. ‘EFAULT’ PATHNAMEPTR is an invalid pointer value. ‘ENAMETOOLONG’ PATHNAME was too long. ‘ENOENT’ A directory component in PATHNAME does not exist. ‘ENOTDIR’ A component of the path is not a directory. ‘EROFS’ The file is on a read-only filesystem. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: stat/fstat, Next: gettimeofday, Prev: unlink, Up: List of Supported Calls stat/fstat .......... Synopsis: int stat(const char *pathname, struct stat *buf); int fstat(int fd, struct stat *buf); Request: ‘Fstat,PATHNAMEPTR/LEN,BUFPTR’ ‘Ffstat,FD,BUFPTR’ Return value: On success, zero is returned. On error, -1 is returned. Errors: ‘EBADF’ FD is not a valid open file. ‘ENOENT’ A directory component in PATHNAME does not exist or the path is an empty string. ‘ENOTDIR’ A component of the path is not a directory. ‘EFAULT’ PATHNAMEPTR is an invalid pointer value. ‘EACCES’ No access to the file or the path of the file. ‘ENAMETOOLONG’ PATHNAME was too long. ‘EINTR’ The call was interrupted by the user.  File: gdb.info, Node: gettimeofday, Next: isatty, Prev: stat/fstat, Up: List of Supported Calls gettimeofday ............ Synopsis: int gettimeofday(struct timeval *tv, void *tz); Request: ‘Fgettimeofday,TVPTR,TZPTR’ Return value: On success, 0 is returned, -1 otherwise. Errors: ‘EINVAL’ TZ is a non-NULL pointer. ‘EFAULT’ TVPTR and/or TZPTR is an invalid pointer value.  File: gdb.info, Node: isatty, Next: system, Prev: gettimeofday, Up: List of Supported Calls isatty ...... Synopsis: int isatty(int fd); Request: ‘Fisatty,FD’ Return value: Returns 1 if FD refers to the GDB console, 0 otherwise. Errors: ‘EINTR’ The call was interrupted by the user. Note that the ‘isatty’ call is treated as a special case: it returns 1 to the target if the file descriptor is attached to the GDB console, 0 otherwise. Implementing through system calls would require implementing ‘ioctl’ and would be more complex than needed.  File: gdb.info, Node: system, Prev: isatty, Up: List of Supported Calls system ...... Synopsis: int system(const char *command); Request: ‘Fsystem,COMMANDPTR/LEN’ Return value: If LEN is zero, the return value indicates whether a shell is available. A zero return value indicates a shell is not available. For non-zero LEN, the value returned is -1 on error and the return status of the command otherwise. Only the exit status of the command is returned, which is extracted from the host's ‘system’ return value by calling ‘WEXITSTATUS(retval)’. In case ‘/bin/sh’ could not be executed, 127 is returned. Errors: ‘EINTR’ The call was interrupted by the user. GDB takes over the full task of calling the necessary host calls to perform the ‘system’ call. The return value of ‘system’ on the host is simplified before it's returned to the target. Any termination signal information from the child process is discarded, and the return value consists entirely of the exit status of the called command. Due to security concerns, the ‘system’ call is by default refused by GDB. The user has to allow this call explicitly with the ‘set remote system-call-allowed 1’ command. ‘set remote system-call-allowed’ Control whether to allow the ‘system’ calls in the File I/O protocol for the remote target. The default is zero (disabled). ‘show remote system-call-allowed’ Show whether the ‘system’ calls are allowed in the File I/O protocol.  File: gdb.info, Node: Protocol-specific Representation of Datatypes, Next: Constants, Prev: List of Supported Calls, Up: File-I/O Remote Protocol Extension E.14.8 Protocol-specific Representation of Datatypes ---------------------------------------------------- * Menu: * Integral Datatypes:: * Pointer Values:: * Memory Transfer:: * struct stat:: * struct timeval::  File: gdb.info, Node: Integral Datatypes, Next: Pointer Values, Up: Protocol-specific Representation of Datatypes Integral Datatypes .................. The integral datatypes used in the system calls are ‘int’, ‘unsigned int’, ‘long’, ‘unsigned long’, ‘mode_t’, and ‘time_t’. ‘int’, ‘unsigned int’, ‘mode_t’ and ‘time_t’ are implemented as 32 bit values in this protocol. ‘long’ and ‘unsigned long’ are implemented as 64 bit types. *Note Limits::, for corresponding MIN and MAX values (similar to those in ‘limits.h’) to allow range checking on host and target. ‘time_t’ datatypes are defined as seconds since the Epoch. All integral datatypes transferred as part of a memory read or write of a structured datatype e.g. a ‘struct stat’ have to be given in big endian byte order.  File: gdb.info, Node: Pointer Values, Next: Memory Transfer, Prev: Integral Datatypes, Up: Protocol-specific Representation of Datatypes Pointer Values .............. Pointers to target data are transmitted as they are. An exception is made for pointers to buffers for which the length isn't transmitted as part of the function call, namely strings. Strings are transmitted as a pointer/length pair, both as hex values, e.g. 1aaf/12 which is a pointer to data of length 18 bytes at position 0x1aaf. The length is defined as the full string length in bytes, including the trailing null byte. For example, the string ‘"hello world"’ at address 0x123456 is transmitted as 123456/d  File: gdb.info, Node: Memory Transfer, Next: struct stat, Prev: Pointer Values, Up: Protocol-specific Representation of Datatypes Memory Transfer ............... Structured data which is transferred using a memory read or write (for example, a ‘struct stat’) is expected to be in a protocol-specific format with all scalar multibyte datatypes being big endian. Translation to this representation needs to be done both by the target before the ‘F’ packet is sent, and by GDB before it transfers memory to the target. Transferred pointers to structured data should point to the already-coerced data at any time.  File: gdb.info, Node: struct stat, Next: struct timeval, Prev: Memory Transfer, Up: Protocol-specific Representation of Datatypes struct stat ........... The buffer of type ‘struct stat’ used by the target and GDB is defined as follows: struct stat { unsigned int st_dev; /* device */ unsigned int st_ino; /* inode */ mode_t st_mode; /* protection */ unsigned int st_nlink; /* number of hard links */ unsigned int st_uid; /* user ID of owner */ unsigned int st_gid; /* group ID of owner */ unsigned int st_rdev; /* device type (if inode device) */ unsigned long st_size; /* total size, in bytes */ unsigned long st_blksize; /* blocksize for filesystem I/O */ unsigned long st_blocks; /* number of blocks allocated */ time_t st_atime; /* time of last access */ time_t st_mtime; /* time of last modification */ time_t st_ctime; /* time of last change */ }; The integral datatypes conform to the definitions given in the appropriate section (see *note Integral Datatypes::, for details) so this structure is of size 64 bytes. The values of several fields have a restricted meaning and/or range of values. ‘st_dev’ A value of 0 represents a file, 1 the console. ‘st_ino’ No valid meaning for the target. Transmitted unchanged. ‘st_mode’ Valid mode bits are described in *note Constants::. Any other bits have currently no meaning for the target. ‘st_uid’ ‘st_gid’ ‘st_rdev’ No valid meaning for the target. Transmitted unchanged. ‘st_atime’ ‘st_mtime’ ‘st_ctime’ These values have a host and file system dependent accuracy. Especially on Windows hosts, the file system may not support exact timing values. The target gets a ‘struct stat’ of the above representation and is responsible for coercing it to the target representation before continuing. Note that due to size differences between the host, target, and protocol representations of ‘struct stat’ members, these members could eventually get truncated on the target.  File: gdb.info, Node: struct timeval, Prev: struct stat, Up: Protocol-specific Representation of Datatypes struct timeval .............. The buffer of type ‘struct timeval’ used by the File-I/O protocol is defined as follows: struct timeval { time_t tv_sec; /* second */ long tv_usec; /* microsecond */ }; The integral datatypes conform to the definitions given in the appropriate section (see *note Integral Datatypes::, for details) so this structure is of size 8 bytes.  File: gdb.info, Node: Constants, Next: File-I/O Examples, Prev: Protocol-specific Representation of Datatypes, Up: File-I/O Remote Protocol Extension E.14.9 Constants ---------------- The following values are used for the constants inside of the protocol. GDB and target are responsible for translating these values before and after the call as needed. * Menu: * Open Flags:: * mode_t Values:: * Errno Values:: * Lseek Flags:: * Limits::  File: gdb.info, Node: Open Flags, Next: mode_t Values, Up: Constants Open Flags .......... All values are given in hexadecimal representation. O_RDONLY 0x0 O_WRONLY 0x1 O_RDWR 0x2 O_APPEND 0x8 O_CREAT 0x200 O_TRUNC 0x400 O_EXCL 0x800  File: gdb.info, Node: mode_t Values, Next: Errno Values, Prev: Open Flags, Up: Constants mode_t Values ............. All values are given in octal representation. S_IFREG 0100000 S_IFDIR 040000 S_IRUSR 0400 S_IWUSR 0200 S_IXUSR 0100 S_IRGRP 040 S_IWGRP 020 S_IXGRP 010 S_IROTH 04 S_IWOTH 02 S_IXOTH 01  File: gdb.info, Node: Errno Values, Next: Lseek Flags, Prev: mode_t Values, Up: Constants Errno Values ............ All values are given in decimal representation. EPERM 1 ENOENT 2 EINTR 4 EBADF 9 EACCES 13 EFAULT 14 EBUSY 16 EEXIST 17 ENODEV 19 ENOTDIR 20 EISDIR 21 EINVAL 22 ENFILE 23 EMFILE 24 EFBIG 27 ENOSPC 28 ESPIPE 29 EROFS 30 ENAMETOOLONG 91 EUNKNOWN 9999 ‘EUNKNOWN’ is used as a fallback error value if a host system returns any error value not in the list of supported error numbers.  File: gdb.info, Node: Lseek Flags, Next: Limits, Prev: Errno Values, Up: Constants Lseek Flags ........... SEEK_SET 0 SEEK_CUR 1 SEEK_END 2  File: gdb.info, Node: Limits, Prev: Lseek Flags, Up: Constants Limits ...... All values are given in decimal representation. INT_MIN -2147483648 INT_MAX 2147483647 UINT_MAX 4294967295 LONG_MIN -9223372036854775808 LONG_MAX 9223372036854775807 ULONG_MAX 18446744073709551615  File: gdb.info, Node: File-I/O Examples, Prev: Constants, Up: File-I/O Remote Protocol Extension E.14.10 File-I/O Examples ------------------------- Example sequence of a write call, file descriptor 3, buffer is at target address 0x1234, 6 bytes should be written: <- Fwrite,3,1234,6 _request memory read from target_ -> m1234,6 <- XXXXXX _return "6 bytes written"_ -> F6 Example sequence of a read call, file descriptor 3, buffer is at target address 0x1234, 6 bytes should be read: <- Fread,3,1234,6 _request memory write to target_ -> X1234,6:XXXXXX _return "6 bytes read"_ -> F6 Example sequence of a read call, call fails on the host due to invalid file descriptor (‘EBADF’): <- Fread,3,1234,6 -> F-1,9 Example sequence of a read call, user presses ‘Ctrl-c’ before syscall on host is called: <- Fread,3,1234,6 -> F-1,4,C <- T02 Example sequence of a read call, user presses ‘Ctrl-c’ after syscall on host is called: <- Fread,3,1234,6 -> X1234,6:XXXXXX <- T02  File: gdb.info, Node: Library List Format, Next: Library List Format for SVR4 Targets, Prev: File-I/O Remote Protocol Extension, Up: Remote Protocol E.15 Library List Format ======================== On some platforms, a dynamic loader (e.g. ‘ld.so’) runs in the same process as your application to manage libraries. In this case, GDB can use the loader's symbol table and normal memory operations to maintain a list of shared libraries. On other platforms, the operating system manages loaded libraries. GDB can not retrieve the list of currently loaded libraries through memory operations, so it uses the ‘qXfer:libraries:read’ packet (*note qXfer library list read::) instead. The remote stub queries the target's operating system and reports which libraries are loaded. The ‘qXfer:libraries:read’ packet returns an XML document which lists loaded libraries and their offsets. Each library has an associated name and one or more segment or section base addresses, which report where the library was loaded in memory. For the common case of libraries that are fully linked binaries, the library should have a list of segments. If the target supports dynamic linking of a relocatable object file, its library XML element should instead include a list of allocated sections. The segment or section bases are start addresses, not relocation offsets; they do not depend on the library's link-time base addresses. GDB must be linked with the Expat library to support XML library lists. *Note Expat::. A simple memory map, with one loaded library relocated by a single offset, looks like this: Another simple memory map, with one loaded library with three allocated sections (.text, .data, .bss), looks like this:
The format of a library list is described by this DTD: In addition, segments and section descriptors cannot be mixed within a single library element, and you must supply at least one segment or section for each library.  File: gdb.info, Node: Library List Format for SVR4 Targets, Next: Memory Map Format, Prev: Library List Format, Up: Remote Protocol E.16 Library List Format for SVR4 Targets ========================================= On SVR4 platforms GDB can use the symbol table of a dynamic loader (e.g. ‘ld.so’) and normal memory operations to maintain a list of shared libraries. Still a special library list provided by this packet is more efficient for the GDB remote protocol. The ‘qXfer:libraries-svr4:read’ packet returns an XML document which lists loaded libraries and their SVR4 linker parameters. For each library on SVR4 target, the following parameters are reported: − ‘name’, the absolute file name from the ‘l_name’ field of ‘struct link_map’. − ‘lm’ with address of ‘struct link_map’ used for TLS (Thread Local Storage) access. − ‘l_addr’, the displacement as read from the field ‘l_addr’ of ‘struct link_map’. For prelinked libraries this is not an absolute memory address. It is a displacement of absolute memory address against address the file was prelinked to during the library load. − ‘l_ld’, which is memory address of the ‘PT_DYNAMIC’ segment − ‘lmid’, which is an identifier for a linker namespace, such as the memory address of the ‘r_debug’ object that contains this namespace's load map or the namespace identifier returned by ‘dlinfo (3)’. Additionally the single ‘main-lm’ attribute specifies address of ‘struct link_map’ used for the main executable. This parameter is used for TLS access and its presence is optional. GDB must be linked with the Expat library to support XML SVR4 library lists. *Note Expat::. A simple memory map, with two loaded libraries (which do not use prelink), looks like this: The format of an SVR4 library list is described by this DTD:  File: gdb.info, Node: Memory Map Format, Next: Thread List Format, Prev: Library List Format for SVR4 Targets, Up: Remote Protocol E.17 Memory Map Format ====================== To be able to write into flash memory, GDB needs to obtain a memory map from the target. This section describes the format of the memory map. The memory map is obtained using the ‘qXfer:memory-map:read’ (*note qXfer memory map read::) packet and is an XML document that lists memory regions. GDB must be linked with the Expat library to support XML memory maps. *Note Expat::. The top-level structure of the document is shown below: region... Each region can be either: • A region of RAM starting at ADDR and extending for LENGTH bytes from there: • A region of read-only memory: • A region of flash memory, with erasure blocks BLOCKSIZE bytes in length: BLOCKSIZE Regions must not overlap. GDB assumes that areas of memory not covered by the memory map are RAM, and uses the ordinary ‘M’ and ‘X’ packets to write to addresses in such ranges. The formal DTD for memory map format is given below:  File: gdb.info, Node: Thread List Format, Next: Traceframe Info Format, Prev: Memory Map Format, Up: Remote Protocol E.18 Thread List Format ======================= To efficiently update the list of threads and their attributes, GDB issues the ‘qXfer:threads:read’ packet (*note qXfer threads read::) and obtains the XML document with the following structure: ... description ... Each ‘thread’ element must have the ‘id’ attribute that identifies the thread (*note thread-id syntax::). The ‘core’ attribute, if present, specifies which processor core the thread was last executing on. The ‘name’ attribute, if present, specifies the human-readable name of the thread. The content of the of ‘thread’ element is interpreted as human-readable auxiliary information. The ‘handle’ attribute, if present, is a hex encoded representation of the thread handle.  File: gdb.info, Node: Traceframe Info Format, Next: Branch Trace Format, Prev: Thread List Format, Up: Remote Protocol E.19 Traceframe Info Format =========================== To be able to know which objects in the inferior can be examined when inspecting a tracepoint hit, GDB needs to obtain the list of memory ranges, registers and trace state variables that have been collected in a traceframe. This list is obtained using the ‘qXfer:traceframe-info:read’ (*note qXfer traceframe info read::) packet and is an XML document. GDB must be linked with the Expat library to support XML traceframe info discovery. *Note Expat::. The top-level structure of the document is shown below: block... Each traceframe block can be either: • A region of collected memory starting at ADDR and extending for LENGTH bytes from there: • A block indicating trace state variable numbered NUMBER has been collected: The formal DTD for the traceframe info format is given below:  File: gdb.info, Node: Branch Trace Format, Next: Branch Trace Configuration Format, Prev: Traceframe Info Format, Up: Remote Protocol E.20 Branch Trace Format ======================== In order to display the branch trace of an inferior thread, GDB needs to obtain the list of branches. This list is represented as list of sequential code blocks that are connected via branches. The code in each block has been executed sequentially. This list is obtained using the ‘qXfer:btrace:read’ (*note qXfer btrace read::) packet and is an XML document. GDB must be linked with the Expat library to support XML traceframe info discovery. *Note Expat::. The top-level structure of the document is shown below: block... • A block of sequentially executed instructions starting at BEGIN and ending at END: The formal DTD for the branch trace format is given below:  File: gdb.info, Node: Branch Trace Configuration Format, Prev: Branch Trace Format, Up: Remote Protocol E.21 Branch Trace Configuration Format ====================================== For each inferior thread, GDB can obtain the branch trace configuration using the ‘qXfer:btrace-conf:read’ (*note qXfer btrace-conf read::) packet. The configuration describes the branch trace format and configuration settings for that format. The following information is described: ‘bts’ This thread uses the “Branch Trace Store” (BTS) format. ‘size’ The size of the BTS ring buffer in bytes. ‘pt’ This thread uses the “Intel Processor Trace” (Intel PT) format. ‘size’ The size of the Intel PT ring buffer in bytes. GDB must be linked with the Expat library to support XML branch trace configuration discovery. *Note Expat::. The formal DTD for the branch trace configuration format is given below:  File: gdb.info, Node: Agent Expressions, Next: Target Descriptions, Prev: Remote Protocol, Up: Top Appendix F The GDB Agent Expression Mechanism ********************************************* In some applications, it is not feasible for the debugger to interrupt the program's execution long enough for the developer to learn anything helpful about its behavior. If the program's correctness depends on its real-time behavior, delays introduced by a debugger might cause the program to fail, even when the code itself is correct. It is useful to be able to observe the program's behavior without interrupting it. Using GDB's ‘trace’ and ‘collect’ commands, the user can specify locations in the program, and arbitrary expressions to evaluate when those locations are reached. Later, using the ‘tfind’ command, she can examine the values those expressions had when the program hit the trace points. The expressions may also denote objects in memory -- structures or arrays, for example -- whose values GDB should record; while visiting a particular tracepoint, the user may inspect those objects as if they were in memory at that moment. However, because GDB records these values without interacting with the user, it can do so quickly and unobtrusively, hopefully not disturbing the program's behavior. When GDB is debugging a remote target, the GDB “agent” code running on the target computes the values of the expressions itself. To avoid having a full symbolic expression evaluator on the agent, GDB translates expressions in the source language into a simpler bytecode language, and then sends the bytecode to the agent; the agent then executes the bytecode, and records the values for GDB to retrieve later. The bytecode language is simple; there are forty-odd opcodes, the bulk of which are the usual vocabulary of C operands (addition, subtraction, shifts, and so on) and various sizes of literals and memory reference operations. The bytecode interpreter operates strictly on machine-level values -- various sizes of integers and floating point numbers -- and requires no information about types or symbols; thus, the interpreter's internal data structures are simple, and each bytecode requires only a few native machine instructions to implement it. The interpreter is small, and strict limits on the memory and time required to evaluate an expression are easy to determine, making it suitable for use by the debugging agent in real-time applications. * Menu: * General Bytecode Design:: Overview of the interpreter. * Bytecode Descriptions:: What each one does. * Using Agent Expressions:: How agent expressions fit into the big picture. * Varying Target Capabilities:: How to discover what the target can do. * Rationale:: Why we did it this way.  File: gdb.info, Node: General Bytecode Design, Next: Bytecode Descriptions, Up: Agent Expressions F.1 General Bytecode Design =========================== The agent represents bytecode expressions as an array of bytes. Each instruction is one byte long (thus the term “bytecode”). Some instructions are followed by operand bytes; for example, the ‘goto’ instruction is followed by a destination for the jump. The bytecode interpreter is a stack-based machine; most instructions pop their operands off the stack, perform some operation, and push the result back on the stack for the next instruction to consume. Each element of the stack may contain either a integer or a floating point value; these values are as many bits wide as the largest integer that can be directly manipulated in the source language. Stack elements carry no record of their type; bytecode could push a value as an integer, then pop it as a floating point value. However, GDB will not generate code which does this. In C, one might define the type of a stack element as follows: union agent_val { LONGEST l; DOUBLEST d; }; where ‘LONGEST’ and ‘DOUBLEST’ are ‘typedef’ names for the largest integer and floating point types on the machine. By the time the bytecode interpreter reaches the end of the expression, the value of the expression should be the only value left on the stack. For tracing applications, ‘trace’ bytecodes in the expression will have recorded the necessary data, and the value on the stack may be discarded. For other applications, like conditional breakpoints, the value may be useful. Separate from the stack, the interpreter has two registers: ‘pc’ The address of the next bytecode to execute. ‘start’ The address of the start of the bytecode expression, necessary for interpreting the ‘goto’ and ‘if_goto’ instructions. Neither of these registers is directly visible to the bytecode language itself, but they are useful for defining the meanings of the bytecode operations. There are no instructions to perform side effects on the running program, or call the program's functions; we assume that these expressions are only used for unobtrusive debugging, not for patching the running code. Most bytecode instructions do not distinguish between the various sizes of values, and operate on full-width values; the upper bits of the values are simply ignored, since they do not usually make a difference to the value computed. The exceptions to this rule are: memory reference instructions (‘ref’N) There are distinct instructions to fetch different word sizes from memory. Once on the stack, however, the values are treated as full-size integers. They may need to be sign-extended; the ‘ext’ instruction exists for this purpose. the sign-extension instruction (‘ext’ N) These clearly need to know which portion of their operand is to be extended to occupy the full length of the word. If the interpreter is unable to evaluate an expression completely for some reason (a memory location is inaccessible, or a divisor is zero, for example), we say that interpretation "terminates with an error". This means that the problem is reported back to the interpreter's caller in some helpful way. In general, code using agent expressions should assume that they may attempt to divide by zero, fetch arbitrary memory locations, and misbehave in other ways. Even complicated C expressions compile to a few bytecode instructions; for example, the expression ‘x + y * z’ would typically produce code like the following, assuming that ‘x’ and ‘y’ live in registers, and ‘z’ is a global variable holding a 32-bit ‘int’: reg 1 reg 2 const32 address of z ref32 ext 32 mul add end In detail, these mean: ‘reg 1’ Push the value of register 1 (presumably holding ‘x’) onto the stack. ‘reg 2’ Push the value of register 2 (holding ‘y’). ‘const32 address of z’ Push the address of ‘z’ onto the stack. ‘ref32’ Fetch a 32-bit word from the address at the top of the stack; replace the address on the stack with the value. Thus, we replace the address of ‘z’ with ‘z’'s value. ‘ext 32’ Sign-extend the value on the top of the stack from 32 bits to full length. This is necessary because ‘z’ is a signed integer. ‘mul’ Pop the top two numbers on the stack, multiply them, and push their product. Now the top of the stack contains the value of the expression ‘y * z’. ‘add’ Pop the top two numbers, add them, and push the sum. Now the top of the stack contains the value of ‘x + y * z’. ‘end’ Stop executing; the value left on the stack top is the value to be recorded.  File: gdb.info, Node: Bytecode Descriptions, Next: Using Agent Expressions, Prev: General Bytecode Design, Up: Agent Expressions F.2 Bytecode Descriptions ========================= Each bytecode description has the following form: ‘add’ (0x02): A B ⇒ A+B Pop the top two stack items, A and B, as integers; push their sum, as an integer. In this example, ‘add’ is the name of the bytecode, and ‘(0x02)’ is the one-byte value used to encode the bytecode, in hexadecimal. The phrase "A B ⇒ A+B" shows the stack before and after the bytecode executes. Beforehand, the stack must contain at least two values, A and B; since the top of the stack is to the right, B is on the top of the stack, and A is underneath it. After execution, the bytecode will have popped A and B from the stack, and replaced them with a single value, A+B. There may be other values on the stack below those shown, but the bytecode affects only those shown. Here is another example: ‘const8’ (0x22) N: ⇒ N Push the 8-bit integer constant N on the stack, without sign extension. In this example, the bytecode ‘const8’ takes an operand N directly from the bytecode stream; the operand follows the ‘const8’ bytecode itself. We write any such operands immediately after the name of the bytecode, before the colon, and describe the exact encoding of the operand in the bytecode stream in the body of the bytecode description. For the ‘const8’ bytecode, there are no stack items given before the ⇒; this simply means that the bytecode consumes no values from the stack. If a bytecode consumes no values, or produces no values, the list on either side of the ⇒ may be empty. If a value is written as A, B, or N, then the bytecode treats it as an integer. If a value is written is ADDR, then the bytecode treats it as an address. We do not fully describe the floating point operations here; although this design can be extended in a clean way to handle floating point values, they are not of immediate interest to the customer, so we avoid describing them, to save time. ‘float’ (0x01): ⇒ Prefix for floating-point bytecodes. Not implemented yet. ‘add’ (0x02): A B ⇒ A+B Pop two integers from the stack, and push their sum, as an integer. ‘sub’ (0x03): A B ⇒ A-B Pop two integers from the stack, subtract the top value from the next-to-top value, and push the difference. ‘mul’ (0x04): A B ⇒ A*B Pop two integers from the stack, multiply them, and push the product on the stack. Note that, when one multiplies two N-bit numbers yielding another N-bit number, it is irrelevant whether the numbers are signed or not; the results are the same. ‘div_signed’ (0x05): A B ⇒ A/B Pop two signed integers from the stack; divide the next-to-top value by the top value, and push the quotient. If the divisor is zero, terminate with an error. ‘div_unsigned’ (0x06): A B ⇒ A/B Pop two unsigned integers from the stack; divide the next-to-top value by the top value, and push the quotient. If the divisor is zero, terminate with an error. ‘rem_signed’ (0x07): A B ⇒ A MODULO B Pop two signed integers from the stack; divide the next-to-top value by the top value, and push the remainder. If the divisor is zero, terminate with an error. ‘rem_unsigned’ (0x08): A B ⇒ A MODULO B Pop two unsigned integers from the stack; divide the next-to-top value by the top value, and push the remainder. If the divisor is zero, terminate with an error. ‘lsh’ (0x09): A B ⇒ A<>B Pop two integers from the stack; let A be the next-to-top value, and B be the top value. Shift A right by B bits, inserting copies of the top bit at the high end, and push the result. ‘rsh_unsigned’ (0x0b): A B ⇒ A>>B Pop two integers from the stack; let A be the next-to-top value, and B be the top value. Shift A right by B bits, inserting zero bits at the high end, and push the result. ‘log_not’ (0x0e): A ⇒ !A Pop an integer from the stack; if it is zero, push the value one; otherwise, push the value zero. ‘bit_and’ (0x0f): A B ⇒ A&B Pop two integers from the stack, and push their bitwise ‘and’. ‘bit_or’ (0x10): A B ⇒ A|B Pop two integers from the stack, and push their bitwise ‘or’. ‘bit_xor’ (0x11): A B ⇒ A^B Pop two integers from the stack, and push their bitwise exclusive-‘or’. ‘bit_not’ (0x12): A ⇒ ~A Pop an integer from the stack, and push its bitwise complement. ‘equal’ (0x13): A B ⇒ A=B Pop two integers from the stack; if they are equal, push the value one; otherwise, push the value zero. ‘less_signed’ (0x14): A B ⇒ A A A Push another copy of the stack's top element. ‘swap’ (0x2b): A B => B A Exchange the top two items on the stack. ‘pop’ (0x29): A => Discard the top value on the stack. ‘pick’ (0x32) N: A ... B => A ... B A Duplicate an item from the stack and push it on the top of the stack. N, a single byte, indicates the stack item to copy. If N is zero, this is the same as ‘dup’; if N is one, it copies the item under the top item, etc. If N exceeds the number of items on the stack, terminate with an error. ‘rot’ (0x33): A B C => C A B Rotate the top three items on the stack. The top item (c) becomes the third item, the next-to-top item (b) becomes the top item and the third item (a) from the top becomes the next-to-top item. ‘if_goto’ (0x20) OFFSET: A ⇒ Pop an integer off the stack; if it is non-zero, branch to the given offset in the bytecode string. Otherwise, continue to the next instruction in the bytecode stream. In other words, if A is non-zero, set the ‘pc’ register to ‘start’ + OFFSET. Thus, an offset of zero denotes the beginning of the expression. The OFFSET is stored as a sixteen-bit unsigned value, stored immediately following the ‘if_goto’ bytecode. It is always stored most significant byte first, regardless of the target's normal endianness. The offset is not guaranteed to fall at any particular alignment within the bytecode stream; thus, on machines where fetching a 16-bit on an unaligned address raises an exception, you should fetch the offset one byte at a time. ‘goto’ (0x21) OFFSET: ⇒ Branch unconditionally to OFFSET; in other words, set the ‘pc’ register to ‘start’ + OFFSET. The offset is stored in the same way as for the ‘if_goto’ bytecode. ‘const8’ (0x22) N: ⇒ N ‘const16’ (0x23) N: ⇒ N ‘const32’ (0x24) N: ⇒ N ‘const64’ (0x25) N: ⇒ N Push the integer constant N on the stack, without sign extension. To produce a small negative value, push a small twos-complement value, and then sign-extend it using the ‘ext’ bytecode. The constant N is stored in the appropriate number of bytes following the ‘const’B bytecode. The constant N is always stored most significant byte first, regardless of the target's normal endianness. The constant is not guaranteed to fall at any particular alignment within the bytecode stream; thus, on machines where fetching a 16-bit on an unaligned address raises an exception, you should fetch N one byte at a time. ‘reg’ (0x26) N: ⇒ A Push the value of register number N, without sign extension. The registers are numbered following GDB's conventions. The register number N is encoded as a 16-bit unsigned integer immediately following the ‘reg’ bytecode. It is always stored most significant byte first, regardless of the target's normal endianness. The register number is not guaranteed to fall at any particular alignment within the bytecode stream; thus, on machines where fetching a 16-bit on an unaligned address raises an exception, you should fetch the register number one byte at a time. ‘getv’ (0x2c) N: ⇒ V Push the value of trace state variable number N, without sign extension. The variable number N is encoded as a 16-bit unsigned integer immediately following the ‘getv’ bytecode. It is always stored most significant byte first, regardless of the target's normal endianness. The variable number is not guaranteed to fall at any particular alignment within the bytecode stream; thus, on machines where fetching a 16-bit on an unaligned address raises an exception, you should fetch the register number one byte at a time. ‘setv’ (0x2d) N: V ⇒ V Set trace state variable number N to the value found on the top of the stack. The stack is unchanged, so that the value is readily available if the assignment is part of a larger expression. The handling of N is as described for ‘getv’. ‘trace’ (0x0c): ADDR SIZE ⇒ Record the contents of the SIZE bytes at ADDR in a trace buffer, for later retrieval by GDB. ‘trace_quick’ (0x0d) SIZE: ADDR ⇒ ADDR Record the contents of the SIZE bytes at ADDR in a trace buffer, for later retrieval by GDB. SIZE is a single byte unsigned integer following the ‘trace’ opcode. This bytecode is equivalent to the sequence ‘dup const8 SIZE trace’, but we provide it anyway to save space in bytecode strings. ‘trace16’ (0x30) SIZE: ADDR ⇒ ADDR Identical to trace_quick, except that SIZE is a 16-bit big-endian unsigned integer, not a single byte. This should probably have been named ‘trace_quick16’, for consistency. ‘tracev’ (0x2e) N: ⇒ A Record the value of trace state variable number N in the trace buffer. The handling of N is as described for ‘getv’. ‘tracenz’ (0x2f) ADDR SIZE ⇒ Record the bytes at ADDR in a trace buffer, for later retrieval by GDB. Stop at either the first zero byte, or when SIZE bytes have been recorded, whichever occurs first. ‘printf’ (0x34) NUMARGS STRING ⇒ Do a formatted print, in the style of the C function ‘printf’). The value of NUMARGS is the number of arguments to expect on the stack, while STRING is the format string, prefixed with a two-byte length. The last byte of the string must be zero, and is included in the length. The format string includes escaped sequences just as it appears in C source, so for instance the format string ‘"\t%d\n"’ is six characters long, and the output will consist of a tab character, a decimal number, and a newline. At the top of the stack, above the values to be printed, this bytecode will pop a "function" and "channel". If the function is nonzero, then the target may treat it as a function and call it, passing the channel as a first argument, as with the C function ‘fprintf’. If the function is zero, then the target may simply call a standard formatted print function of its choice. In all, this bytecode pops 2 + NUMARGS stack elements, and pushes nothing. ‘end’ (0x27): ⇒ Stop executing bytecode; the result should be the top element of the stack. If the purpose of the expression was to compute an lvalue or a range of memory, then the next-to-top of the stack is the lvalue's address, and the top of the stack is the lvalue's size, in bytes.  File: gdb.info, Node: Using Agent Expressions, Next: Varying Target Capabilities, Prev: Bytecode Descriptions, Up: Agent Expressions F.3 Using Agent Expressions =========================== Agent expressions can be used in several different ways by GDB, and the debugger can generate different bytecode sequences as appropriate. One possibility is to do expression evaluation on the target rather than the host, such as for the conditional of a conditional tracepoint. In such a case, GDB compiles the source expression into a bytecode sequence that simply gets values from registers or memory, does arithmetic, and returns a result. Another way to use agent expressions is for tracepoint data collection. GDB generates a different bytecode sequence for collection; in addition to bytecodes that do the calculation, GDB adds ‘trace’ bytecodes to save the pieces of memory that were used. • The user selects trace points in the program's code at which GDB should collect data. • The user specifies expressions to evaluate at each trace point. These expressions may denote objects in memory, in which case those objects' contents are recorded as the program runs, or computed values, in which case the values themselves are recorded. • GDB transmits the tracepoints and their associated expressions to the GDB agent, running on the debugging target. • The agent arranges to be notified when a trace point is hit. • When execution on the target reaches a trace point, the agent evaluates the expressions associated with that trace point, and records the resulting values and memory ranges. • Later, when the user selects a given trace event and inspects the objects and expression values recorded, GDB talks to the agent to retrieve recorded data as necessary to meet the user's requests. If the user asks to see an object whose contents have not been recorded, GDB reports an error.  File: gdb.info, Node: Varying Target Capabilities, Next: Rationale, Prev: Using Agent Expressions, Up: Agent Expressions F.4 Varying Target Capabilities =============================== Some targets don't support floating-point, and some would rather not have to deal with ‘long long’ operations. Also, different targets will have different stack sizes, and different bytecode buffer lengths. Thus, GDB needs a way to ask the target about itself. We haven't worked out the details yet, but in general, GDB should be able to send the target a packet asking it to describe itself. The reply should be a packet whose length is explicit, so we can add new information to the packet in future revisions of the agent, without confusing old versions of GDB, and it should contain a version number. It should contain at least the following information: • whether floating point is supported • whether ‘long long’ is supported • maximum acceptable size of bytecode stack • maximum acceptable length of bytecode expressions • which registers are actually available for collection • whether the target supports disabled tracepoints  File: gdb.info, Node: Rationale, Prev: Varying Target Capabilities, Up: Agent Expressions F.5 Rationale ============= Some of the design decisions apparent above are arguable. What about stack overflow/underflow? GDB should be able to query the target to discover its stack size. Given that information, GDB can determine at translation time whether a given expression will overflow the stack. But this spec isn't about what kinds of error-checking GDB ought to do. Why are you doing everything in LONGEST? Speed isn't important, but agent code size is; using LONGEST brings in a bunch of support code to do things like division, etc. So this is a serious concern. First, note that you don't need different bytecodes for different operand sizes. You can generate code without _knowing_ how big the stack elements actually are on the target. If the target only supports 32-bit ints, and you don't send any 64-bit bytecodes, everything just works. The observation here is that the MIPS and the Alpha have only fixed-size registers, and you can still get C's semantics even though most instructions only operate on full-sized words. You just need to make sure everything is properly sign-extended at the right times. So there is no need for 32- and 64-bit variants of the bytecodes. Just implement everything using the largest size you support. GDB should certainly check to see what sizes the target supports, so the user can get an error earlier, rather than later. But this information is not necessary for correctness. Why don't you have ‘>’ or ‘<=’ operators? I want to keep the interpreter small, and we don't need them. We can combine the ‘less_’ opcodes with ‘log_not’, and swap the order of the operands, yielding all four asymmetrical comparison operators. For example, ‘(x <= y)’ is ‘! (x > y)’, which is ‘! (y < x)’. Why do you have ‘log_not’? Why do you have ‘ext’? Why do you have ‘zero_ext’? These are all easily synthesized from other instructions, but I expect them to be used frequently, and they're simple, so I include them to keep bytecode strings short. ‘log_not’ is equivalent to ‘const8 0 equal’; it's used in half the relational operators. ‘ext N’ is equivalent to ‘const8 S-N lsh const8 S-N rsh_signed’, where S is the size of the stack elements; it follows ‘refM’ and REG bytecodes when the value should be signed. See the next bulleted item. ‘zero_ext N’ is equivalent to ‘constM MASK log_and’; it's used whenever we push the value of a register, because we can't assume the upper bits of the register aren't garbage. Why not have sign-extending variants of the ‘ref’ operators? Because that would double the number of ‘ref’ operators, and we need the ‘ext’ bytecode anyway for accessing bitfields. Why not have constant-address variants of the ‘ref’ operators? Because that would double the number of ‘ref’ operators again, and ‘const32 ADDRESS ref32’ is only one byte longer. Why do the ‘refN’ operators have to support unaligned fetches? GDB will generate bytecode that fetches multi-byte values at unaligned addresses whenever the executable's debugging information tells it to. Furthermore, GDB does not know the value the pointer will have when GDB generates the bytecode, so it cannot determine whether a particular fetch will be aligned or not. In particular, structure bitfields may be several bytes long, but follow no alignment rules; members of packed structures are not necessarily aligned either. In general, there are many cases where unaligned references occur in correct C code, either at the programmer's explicit request, or at the compiler's discretion. Thus, it is simpler to make the GDB agent bytecodes work correctly in all circumstances than to make GDB guess in each case whether the compiler did the usual thing. Why are there no side-effecting operators? Because our current client doesn't want them? That's a cheap answer. I think the real answer is that I'm afraid of implementing function calls. We should re-visit this issue after the present contract is delivered. Why aren't the ‘goto’ ops PC-relative? The interpreter has the base address around anyway for PC bounds checking, and it seemed simpler. Why is there only one offset size for the ‘goto’ ops? Offsets are currently sixteen bits. I'm not happy with this situation either: Suppose we have multiple branch ops with different offset sizes. As I generate code left-to-right, all my jumps are forward jumps (there are no loops in expressions), so I never know the target when I emit the jump opcode. Thus, I have to either always assume the largest offset size, or do jump relaxation on the code after I generate it, which seems like a big waste of time. I can imagine a reasonable expression being longer than 256 bytes. I can't imagine one being longer than 64k. Thus, we need 16-bit offsets. This kind of reasoning is so bogus, but relaxation is pathetic. The other approach would be to generate code right-to-left. Then I'd always know my offset size. That might be fun. Where is the function call bytecode? When we add side-effects, we should add this. Why does the ‘reg’ bytecode take a 16-bit register number? Intel's IA-64 architecture has 128 general-purpose registers, and 128 floating-point registers, and I'm sure it has some random control registers. Why do we need ‘trace’ and ‘trace_quick’? Because GDB needs to record all the memory contents and registers an expression touches. If the user wants to evaluate an expression ‘x->y->z’, the agent must record the values of ‘x’ and ‘x->y’ as well as the value of ‘x->y->z’. Don't the ‘trace’ bytecodes make the interpreter less general? They do mean that the interpreter contains special-purpose code, but that doesn't mean the interpreter can only be used for that purpose. If an expression doesn't use the ‘trace’ bytecodes, they don't get in its way. Why doesn't ‘trace_quick’ consume its arguments the way everything else does? In general, you do want your operators to consume their arguments; it's consistent, and generally reduces the amount of stack rearrangement necessary. However, ‘trace_quick’ is a kludge to save space; it only exists so we needn't write ‘dup const8 SIZE trace’ before every memory reference. Therefore, it's okay for it not to consume its arguments; it's meant for a specific context in which we know exactly what it should do with the stack. If we're going to have a kludge, it should be an effective kludge. Why does ‘trace16’ exist? That opcode was added by the customer that contracted Cygnus for the data tracing work. I personally think it is unnecessary; objects that large will be quite rare, so it is okay to use ‘dup const16 SIZE trace’ in those cases. Whatever we decide to do with ‘trace16’, we should at least leave opcode 0x30 reserved, to remain compatible with the customer who added it.  File: gdb.info, Node: Target Descriptions, Next: Operating System Information, Prev: Agent Expressions, Up: Top Appendix G Target Descriptions ****************************** One of the challenges of using GDB to debug embedded systems is that there are so many minor variants of each processor architecture in use. It is common practice for vendors to start with a standard processor core -- ARM, PowerPC, or MIPS, for example -- and then make changes to adapt it to a particular market niche. Some architectures have hundreds of variants, available from dozens of vendors. This leads to a number of problems: • With so many different customized processors, it is difficult for the GDB maintainers to keep up with the changes. • Since individual variants may have short lifetimes or limited audiences, it may not be worthwhile to carry information about every variant in the GDB source tree. • When GDB does support the architecture of the embedded system at hand, the task of finding the correct architecture name to give the ‘set architecture’ command can be error-prone. To address these problems, the GDB remote protocol allows a target system to not only identify itself to GDB, but to actually describe its own features. This lets GDB support processor variants it has never seen before -- to the extent that the descriptions are accurate, and that GDB understands them. GDB must be linked with the Expat library to support XML target descriptions. *Note Expat::. * Menu: * Retrieving Descriptions:: How descriptions are fetched from a target. * Target Description Format:: The contents of a target description. * Predefined Target Types:: Standard types available for target descriptions. * Enum Target Types:: How to define enum target types. * Standard Target Features:: Features GDB knows about.  File: gdb.info, Node: Retrieving Descriptions, Next: Target Description Format, Up: Target Descriptions G.1 Retrieving Descriptions =========================== Target descriptions can be read from the target automatically, or specified by the user manually. The default behavior is to read the description from the target. GDB retrieves it via the remote protocol using ‘qXfer’ requests (*note qXfer: General Query Packets.). The ANNEX in the ‘qXfer’ packet will be ‘target.xml’. The contents of the ‘target.xml’ annex are an XML document, of the form described in *note Target Description Format::. Alternatively, you can specify a file to read for the target description. If a file is set, the target will not be queried. The commands to specify a file are: ‘set tdesc filename PATH’ Read the target description from PATH. ‘unset tdesc filename’ Do not read the XML target description from a file. GDB will use the description supplied by the current target. ‘show tdesc filename’ Show the filename to read for a target description, if any.  File: gdb.info, Node: Target Description Format, Next: Predefined Target Types, Prev: Retrieving Descriptions, Up: Target Descriptions G.2 Target Description Format ============================= A target description annex is an XML (http://www.w3.org/XML/) document which complies with the Document Type Definition provided in the GDB sources in ‘gdb/features/gdb-target.dtd’. This means you can use generally available tools like ‘xmllint’ to check that your feature descriptions are well-formed and valid. However, to help people unfamiliar with XML write descriptions for their targets, we also describe the grammar here. Target descriptions can identify the architecture of the remote target and (for some architectures) provide information about custom register sets. They can also identify the OS ABI of the remote target. GDB can use this information to autoconfigure for your target, or to warn you if you connect to an unsupported target. Here is a simple target description: i386:x86-64 This minimal description only says that the target uses the x86-64 architecture. A target description has the following overall form, with [ ] marking optional elements and ... marking repeatable elements. The elements are explained further below. [ARCHITECTURE] [OSABI] [COMPATIBLE] [FEATURE...] The description is generally insensitive to whitespace and line breaks, under the usual common-sense rules. The XML version declaration and document type declaration can generally be omitted (GDB does not require them), but specifying them may be useful for XML validation tools. The ‘version’ attribute for ‘’ may also be omitted, but we recommend including it; if future versions of GDB use an incompatible revision of ‘gdb-target.dtd’, they will detect and report the version mismatch. G.2.1 Inclusion --------------- It can sometimes be valuable to split a target description up into several different annexes, either for organizational purposes, or to share files between different possible target descriptions. You can divide a description into multiple files by replacing any element of the target description with an inclusion directive of the form: When GDB encounters an element of this form, it will retrieve the named XML DOCUMENT, and replace the inclusion directive with the contents of that document. If the current description was read using ‘qXfer’, then so will be the included document; DOCUMENT will be interpreted as the name of an annex. If the current description was read from a file, GDB will look for DOCUMENT as a file in the same directory where it found the original description. G.2.2 Architecture ------------------ An ‘’ element has this form: ARCH ARCH is one of the architectures from the set accepted by ‘set architecture’ (*note Specifying a Debugging Target: Targets.). G.2.3 OS ABI ------------ This optional field was introduced in GDB version 7.0. Previous versions of GDB ignore it. An ‘’ element has this form: ABI-NAME ABI-NAME is an OS ABI name from the same selection accepted by ‘set osabi’ (*note Configuring the Current ABI: ABI.). G.2.4 Compatible Architecture ----------------------------- This optional field was introduced in GDB version 7.0. Previous versions of GDB ignore it. A ‘’ element has this form: ARCH ARCH is one of the architectures from the set accepted by ‘set architecture’ (*note Specifying a Debugging Target: Targets.). A ‘’ element is used to specify that the target is able to run binaries in some other than the main target architecture given by the ‘’ element. For example, on the Cell Broadband Engine, the main architecture is ‘powerpc:common’ or ‘powerpc:common64’, but the system is able to run binaries in the ‘spu’ architecture as well. The way to describe this capability with ‘’ is as follows: powerpc:common spu G.2.5 Features -------------- Each ‘’ describes some logical portion of the target system. Features are currently used to describe available CPU registers and the types of their contents. A ‘’ element has this form: [TYPE...] REG... Each feature's name should be unique within the description. The name of a feature does not matter unless GDB has some special knowledge of the contents of that feature; if it does, the feature should have its standard name. *Note Standard Target Features::. G.2.6 Types ----------- Any register's value is a collection of bits which GDB must interpret. The default interpretation is a two's complement integer, but other types can be requested by name in the register description. Some predefined types are provided by GDB (*note Predefined Target Types::), and the description can define additional composite and enum types. Each type element must have an ‘id’ attribute, which gives a unique (within the containing ‘’) name to the type. Types must be defined before they are used. Some targets offer vector registers, which can be treated as arrays of scalar elements. These types are written as ‘’ elements, specifying the array element type, TYPE, and the number of elements, COUNT: If a register's value is usefully viewed in multiple ways, define it with a union type containing the useful representations. The ‘’ element contains one or more ‘’ elements, each of which has a NAME and a TYPE: ... If a register's value is composed from several separate values, define it with either a structure type or a flags type. A flags type may only contain bitfields. A structure type may either contain only bitfields or contain no bitfields. If the value contains only bitfields, its total size in bytes must be specified. Non-bitfield values have a NAME and TYPE. ... Both NAME and TYPE values are required. No implicit padding is added. Bitfield values have a NAME, START, END and TYPE. ... ... The NAME value is required. Bitfield values may be named with the empty string, ‘""’, in which case the field is "filler" and its value is not printed. Not all bits need to be specified, so "filler" fields are optional. The START and END values are required, and TYPE is optional. The field's START must be less than or equal to its END, and zero represents the least significant bit. The default value of TYPE is ‘bool’ for single bit fields, and an unsigned integer otherwise. Which to choose? Structures or flags? Registers defined with ‘flags’ have these advantages over defining them with ‘struct’: • Arithmetic may be performed on them as if they were integers. • They are printed in a more readable fashion. Registers defined with ‘struct’ have one advantage over defining them with ‘flags’: • One can fetch individual fields like in ‘C’. (gdb) print $my_struct_reg.field3 $1 = 42 G.2.7 Registers --------------- Each register is represented as an element with this form: The components are as follows: NAME The register's name; it must be unique within the target description. BITSIZE The register's size, in bits. REGNUM The register's number. If omitted, a register's number is one greater than that of the previous register (either in the current feature or in a preceding feature); the first register in the target description defaults to zero. This register number is used to read or write the register; e.g. it is used in the remote ‘p’ and ‘P’ packets, and registers appear in the ‘g’ and ‘G’ packets in order of increasing register number. SAVE-RESTORE Whether the register should be preserved across inferior function calls; this must be either ‘yes’ or ‘no’. The default is ‘yes’, which is appropriate for most registers except for some system control registers; this is not related to the target's ABI. TYPE The type of the register. It may be a predefined type, a type defined in the current feature, or one of the special types ‘int’ and ‘float’. ‘int’ is an integer type of the correct size for BITSIZE, and ‘float’ is a floating point type (in the architecture's normal floating point format) of the correct size for BITSIZE. The default is ‘int’. GROUP The register group to which this register belongs. It can be one of the standard register groups ‘general’, ‘float’, ‘vector’ or an arbitrary string. Group names should be limited to alphanumeric characters. If a group name is made up of multiple words the words may be separated by hyphens; e.g. ‘special-group’ or ‘ultra-special-group’. If no GROUP is specified, GDB will not display the register in ‘info registers’.  File: gdb.info, Node: Predefined Target Types, Next: Enum Target Types, Prev: Target Description Format, Up: Target Descriptions G.3 Predefined Target Types =========================== Type definitions in the self-description can build up composite types from basic building blocks, but can not define fundamental types. Instead, standard identifiers are provided by GDB for the fundamental types. The currently supported types are: ‘bool’ Boolean type, occupying a single bit. ‘int8’ ‘int16’ ‘int24’ ‘int32’ ‘int64’ ‘int128’ Signed integer types holding the specified number of bits. ‘uint8’ ‘uint16’ ‘uint24’ ‘uint32’ ‘uint64’ ‘uint128’ Unsigned integer types holding the specified number of bits. ‘code_ptr’ ‘data_ptr’ Pointers to unspecified code and data. The program counter and any dedicated return address register may be marked as code pointers; printing a code pointer converts it into a symbolic address. The stack pointer and any dedicated address registers may be marked as data pointers. ‘ieee_half’ Half precision IEEE floating point. ‘ieee_single’ Single precision IEEE floating point. ‘ieee_double’ Double precision IEEE floating point. ‘bfloat16’ The 16-bit “brain floating point” format used e.g. by x86 and ARM. ‘arm_fpa_ext’ The 12-byte extended precision format used by ARM FPA registers. ‘i387_ext’ The 10-byte extended precision format used by x87 registers. ‘i386_eflags’ 32bit EFLAGS register used by x86. ‘i386_mxcsr’ 32bit MXCSR register used by x86.  File: gdb.info, Node: Enum Target Types, Next: Standard Target Features, Prev: Predefined Target Types, Up: Target Descriptions G.4 Enum Target Types ===================== Enum target types are useful in ‘struct’ and ‘flags’ register descriptions. *Note Target Description Format::. Enum types have a name, size and a list of name/value pairs. ... Enums must be defined before they are used. Given that description, a value of 3 for the ‘flags’ register would be printed as: (gdb) info register flags flags 0x3 [ X LEVEL=high ]  File: gdb.info, Node: Standard Target Features, Prev: Enum Target Types, Up: Target Descriptions G.5 Standard Target Features ============================ A target description must contain either no registers or all the target's registers. If the description contains no registers, then GDB will assume a default register layout, selected based on the architecture. If the description contains any registers, the default layout will not be used; the standard registers must be described in the target description, in such a way that GDB can recognize them. This is accomplished by giving specific names to feature elements which contain standard registers. GDB will look for features with those names and verify that they contain the expected registers; if any known feature is missing required registers, or if any required feature is missing, GDB will reject the target description. You can add additional registers to any of the standard features -- GDB will display them just as if they were added to an unrecognized feature. This section lists the known features and their expected contents. Sample XML documents for these features are included in the GDB source tree, in the directory ‘gdb/features’. Names recognized by GDB should include the name of the company or organization which selected the name, and the overall architecture to which the feature applies; so e.g. the feature containing ARM core registers is named ‘org.gnu.gdb.arm.core’. The names of registers are not case sensitive for the purpose of recognizing standard features, but GDB will only display registers using the capitalization used in the description. * Menu: * AArch64 Features:: * ARC Features:: * ARM Features:: * i386 Features:: * LoongArch Features:: * MicroBlaze Features:: * MIPS Features:: * M68K Features:: * NDS32 Features:: * Nios II Features:: * OpenRISC 1000 Features:: * PowerPC Features:: * RISC-V Features:: * RX Features:: * S/390 and System z Features:: * Sparc Features:: * TIC6x Features::  File: gdb.info, Node: AArch64 Features, Next: ARC Features, Up: Standard Target Features G.5.1 AArch64 Features ---------------------- G.5.1.1 AArch64 core registers feature ...................................... The ‘org.gnu.gdb.aarch64.core’ feature is required for AArch64 targets. It must contain the following: − ‘x0’ through ‘x30’, the general purpose registers, with size of 64 bits. Register ‘x30’ is also known as the “link register”, or ‘lr’. − ‘sp’, the stack pointer register or ‘x31’. It is 64 bits in size and has a type of ‘data_ptr’. − ‘pc’, the program counter register. It is 64 bits in size and has a type of ‘code_ptr’. − ‘cpsr’, the current program status register. It is 32 bits in size and has a custom flags type. The semantics of the individual flags and fields in ‘cpsr’ can change as new architectural features are added. The current layout can be found in the aarch64-core.xml file. Extra registers are allowed in this feature, but they will not affect GDB. G.5.1.2 AArch64 floating-point registers feature ................................................ The ‘org.gnu.gdb.aarch64.fpu’ feature is optional. If present, it must contain the following registers: − ‘v0’ through ‘v31’, the vector registers with size of 128 bits. The type is a custom vector type. − ‘fpsr’, the floating-point status register. It is 32 bits in size and has a custom flags type. − ‘fpcr’, the floating-point control register. It is 32 bits in size and has a custom flags type. The semantics of the individual flags and fields in ‘fpsr’ and ‘fpcr’ can change as new architectural features are added. The types for the vector registers, ‘fpsr’ and ‘fpcr’ registers can be found in the aarch64-fpu.xml file. Extra registers are allowed in this feature, but they will not affect GDB. G.5.1.3 AArch64 SVE registers feature ..................................... The ‘org.gnu.gdb.aarch64.sve’ feature is optional. If present, it means the target supports the Scalable Vector Extension and must contain the following registers: − ‘z0’ through ‘z31’, the scalable vector registers. Their sizes are variable and a multiple of 128 bits up to a maximum of 2048 bit. Their type is a custom union type that helps visualize different sizes of sub-vectors. − ‘fpsr’, the floating-point status register. It is 32 bits in size and has a custom flags type. − ‘fpcr’, the floating-point control register. It is 32 bits in size and has a custom flags type. − ‘p0’ through ‘p15’, the predicate registers. Their sizes are variable, based on the current vector length, and a multiple of 16 bits. Their types are a custom union to help visualize sub-elements. − ‘ffr’, the First Fault register. It has a variable size based on the current vector length and is a multiple of 16 bits. The type is the same as the predicate registers. − ‘vg’, the vector granule. It represents the number of 64 bits chunks in a ‘z’ register. It is closely associated with the current vector length. It has a type of ‘int’. When GDB sees the SVE feature, it will assume the Scalable Vector Extension is supported, and will adjust the sizes of the ‘z’, ‘p’ and ‘ffr’ registers accordingly, based on the value of ‘vg’. GDB will also create pseudo-registers equivalent to the ‘v’ vector registers from the ‘org.gnu.gdb.aarch64.fpu’ feature. The first 128 bits of the ‘z’ registers overlap the 128 bits of the ‘v’ registers, so changing one will trigger a change to the other. For the types of the ‘z’, ‘p’ and ‘ffr’ registers, please check the aarch64-sve.c file. No XML file is available for this feature because it is dynamically generated based on the current vector length. The semantics of the individual flags and fields in ‘fpsr’ and ‘fpcr’ can change as new architectural features are added. The types for the ‘fpsr’ and ‘fpcr’ registers can be found in the aarch64-sve.c file, and should match what is described in aarch64-fpu.xml. Extra registers are allowed in this feature, but they will not affect GDB. G.5.1.4 AArch64 Pointer Authentication registers feature ........................................................ The ‘org.gnu.gdb.aarch64.pauth’ optional feature was introduced so GDB could detect support for the Pointer Authentication extension. If present, it must contain one of two possible register sets. Pointer Authentication masks for user-mode: − ‘pauth_dmask’, the user-mode pointer authentication mask for data pointers. It is 64 bits in size. − ‘pauth_cmask’, the user-mode pointer authentication mask for code pointers. It is 64 bits in size. Pointer Authentication masks for user-mode and kernel-mode: − ‘pauth_dmask’, the user-mode pointer authentication mask for data pointers. It is 64 bits in size. − ‘pauth_cmask’, the user-mode pointer authentication mask for code pointers. It is 64 bits in size. − ‘pauth_dmask_high’, the kernel-mode pointer authentication mask for data pointers. It is 64 bits in size. − ‘pauth_cmask_high’, the kernel-mode pointer authentication mask for code pointers. It is 64 bits in size. If GDB sees any of the two sets of registers in this feature, it will assume the target is capable of signing pointers. If so, GDB will decorate backtraces with a ‘[PAC]’ marker alongside a function that has a signed link register value that needs to be unmasked/decoded. GDB will also use the masks to remove non-address bits from pointers. Extra registers are allowed in this feature, but they will not affect GDB. Please note the ‘org.gnu.gdb.aarch64.pauth’ feature string is deprecated and must only be used for backwards compatibility with older releases of GDB and ‘gdbserver’. Targets that support Pointer Authentication must advertise such capability by using the ‘org.gnu.gdb.aarch64.pauth_v2’ feature string instead. The ‘org.gnu.gdb.aarch64.pauth_v2’ feature has the exact same contents as feature ‘org.gnu.gdb.aarch64.pauth’. The reason for having feature ‘org.gnu.gdb.aarch64.pauth_v2’ is a bug in previous versions of GDB (versions 9, 10, 11 and 12). This bug caused GDB to crash whenever the target reported support for Pointer Authentication (using feature string ‘org.gnu.gdb.aarch64.pauth’) and also reported additional system registers that were not accounted for by GDB. This is more common when using emulators and on bare-metal debugging scenarios. It can also happen if a newer gdbserver is used with an old GDB that has the bug. In such a case, the newer gdbserver might report Pointer Authentication support via the ‘org.gnu.gdb.aarch64.pauth’ feature string and also report additional registers the older GDB does not know about, potentially leading to a crash. G.5.1.5 AArch64 TLS registers feature ..................................... The ‘org.gnu.gdb.aarch64.tls’ optional feature was introduced to expose the TLS registers to GDB. If present, it must contain either one of the following register sets. Only ‘tpidr’: − ‘tpidr’, the software thread id register. It is 64 bits in size and has a type of ‘data_ptr’. Both ‘tpidr’ and ‘tpidr2’. − ‘tpidr’, the software thread id register. It is 64 bits in size and has a type of ‘data_ptr’. − ‘tpidr2’, the second software thread id register. It is 64 bits in size and has a type of ‘data_ptr’. It may be used in the future alongside the Scalable Matrix Extension for a lazy restore scheme. If GDB sees this feature, it will attempt to find one of the variations of the register set. If ‘tpidr2’ is available, GDB may act on it to display additional data in the future. There is no XML for this feature as the presence of ‘tpidr2’ is determined dynamically at runtime. Extra registers are allowed in this feature, but they will not affect GDB. G.5.1.6 AArch64 MTE registers feature ..................................... The ‘org.gnu.gdb.aarch64.mte’ optional feature was introduced so GDB could detect support for the Memory Tagging Extension and control memory tagging settings. If present, this feature must have the following register: − ‘tag_ctl’, the tag control register. It is 64 bits in size and has a type of ‘uint64’. Memory Tagging detection is done via a runtime check though, so the presence of this feature and register is not enough to enable memory tagging support. This restriction may be lifted in the future. Extra registers are allowed in this feature, but they will not affect GDB. G.5.1.7 AArch64 SME registers feature ..................................... The ‘org.gnu.gdb.aarch64.sme’ feature is optional. If present, it should contain registers ‘ZA’, ‘SVG’ and ‘SVCR’. *Note AArch64 SME::. − ‘ZA’ is a register represented by a vector of SVLxSVL bytes. *Note svl::. − ‘SVG’ is a 64-bit register containing the value of SVG. *Note svg::. − ‘SVCR’ is a 64-bit status pseudo-register with two valid bits. Bit 0 (SM) shows whether the streaming SVE mode is enabled or disabled. Bit 1 (ZA) shows whether the ‘ZA’ register state is active (in use) or not. *Note aarch64 sme svcr::. The rest of the unused bits of the ‘SVCR’ pseudo-register is undefined and reserved. Such bits should not be used and may be defined by future extensions of the architecture. Extra registers are allowed in this feature, but they will not affect GDB. The ‘org.gnu.gdb.aarch64.sme’ feature is required when the target also reports support for the ‘org.gnu.gdb.aarch64.sme2’ feature. G.5.1.8 AArch64 SME2 registers feature ...................................... The ‘org.gnu.gdb.aarch64.sme2’ feature is optional. If present, then the ‘org.gnu.gdb.aarch64.sme’ feature must also be present. The ‘org.gnu.gdb.aarch64.sme2’ feature should contain the following: *Note AArch64 SME2::. − ‘ZT0’ is a register of 512 bits (64 bytes). It is defined as a vector of bytes. Extra registers are allowed in this feature, but they will not affect GDB.  File: gdb.info, Node: ARC Features, Next: ARM Features, Prev: AArch64 Features, Up: Standard Target Features G.5.2 ARC Features ------------------ ARC processors are so configurable that even core registers and their numbers are not predetermined completely. Moreover, _flags_ and _PC_ registers, which are important to GDB, are not "core" registers in ARC. Therefore, there are two features that their presence is mandatory: ‘org.gnu.gdb.arc.core’ and ‘org.gnu.gdb.arc.aux’. The ‘org.gnu.gdb.arc.core’ feature is required for all targets. It must contain registers: − ‘r0’ through ‘r25’ for normal register file targets. − ‘r0’ through ‘r3’, and ‘r10’ through ‘r15’ for reduced register file targets. − ‘gp’, ‘fp’, ‘sp’, ‘r30’(1), ‘blink’, ‘lp_count’, ‘pcl’. In case of an ARCompact target (ARCv1 ISA), the ‘org.gnu.gdb.arc.core’ feature may contain registers ‘ilink1’ and ‘ilink2’. While in case of ARC EM and ARC HS targets (ARCv2 ISA), register ‘ilink’ may be present. The difference between ARCv1 and ARCv2 is the naming of registers _29th_ and _30th_. They are called ‘ilink1’ and ‘ilink2’ for ARCv1 and are optional. For ARCv2, they are called ‘ilink’ and ‘r30’ and only ‘ilink’ is optional. The optionality of ‘ilink*’ registers is because of their inaccessibility during user space debugging sessions. Extension core registers ‘r32’ through ‘r59’ are optional and their existence depends on the configuration. When debugging GNU/Linux applications, i.e. user space debugging, these core registers are not available. The ‘org.gnu.gdb.arc.aux’ feature is required for all ARC targets. Here is the list of registers pertinent to this feature: − mandatory: ‘pc’ and ‘status32’. − optional: ‘lp_start’, ‘lp_end’, and ‘bta’. ---------- Footnotes ---------- (1) Not necessary for ARCv1.  File: gdb.info, Node: ARM Features, Next: i386 Features, Prev: ARC Features, Up: Standard Target Features G.5.3 ARM Features ------------------ G.5.3.1 Core register set for non-M-profile ........................................... The ‘org.gnu.gdb.arm.core’ feature is required for non-M-profile ARM targets. It must contain the following registers: − ‘r0’ through ‘r12’. The general purpose registers. They are 32 bits in size and have a type of ‘uint32’. − ‘sp’, the stack pointer register, also known as ‘r13’. It is 32 bits in size and has a type of ‘data_ptr’. − ‘lr’, the link register. It is 32 bits in size. − ‘pc’, the program counter register. It is 32 bit in size and of type ‘code_ptr’. − ‘cpsr’, the current program status register containing all the status bits. It is 32 bits in size. Historically this register was hardwired to number 25, but debugging stubs that report XML do not need to use this number anymore. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.2 Core register set for M-profile ....................................... For M-profile targets (e.g. Cortex-M3), the ‘org.gnu.gdb.arm.core’ feature is replaced by ‘org.gnu.gdb.arm.m-profile’, and it is a required feature. It must contain the following registers: − ‘r0’ through ‘r12’, the general purpose registers. They have a size of 32 bits and a type of ‘uint32’. − ‘sp’, the stack pointer register, also known as ‘r13’. It has a size of 32 bits and a type of ‘data_ptr’. − ‘lr’, the link register. It has a size of 32 bits. − ‘pc’, the program counter register. It has a size of 32 bits and a type of ‘code_ptr’. − ‘xpsr’, the program status register containing all the status bits. It has a size of 32 bits. Historically this register was hardwired to number 25, but debugging stubs that report XML do not need to use this number anymore. Upon seeing this feature, GDB will acknowledge that it is dealing with an M-profile target. This means GDB will use hooks and configurations that are meaningful to M-profiles. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.3 FPA registers feature (obsolete) ........................................ The ‘org.gnu.gdb.arm.fpa’ feature is obsolete and should not be advertised by debugging stubs anymore. It used to advertise registers for the old FPA architecture that has long been discontinued in toolchains. It is kept in GDB for backward compatibility purposes so older debugging stubs that don't support XML target descriptions still work correctly. One such example is the KGDB debugging stub from Linux or BSD kernels. The description below is for historical purposes only. This feature used to contain the following registers: − ‘f0’ through ‘f8’. The floating point registers. They are 96 bits in size and of type ‘arm_fpa_ext’. ‘f0’ is pinned to register number 16. − ‘fps’, the status register. It has a size of 32 bits. G.5.3.4 M-profile Vector Extension (MVE) ........................................ Also known as Helium, the M-profile Vector Extension is advertised via the optional ‘org.gnu.gdb.arm.m-profile-mve’ feature. It must contain the following: − ‘vpr’, the vector predication status and control register. It is 32 bits in size and has a custom flags type. The flags type is laid out in a way that exposes the ‘P0’ field from bits 0 to 15, the ‘MASK01’ field from bits 16 to 19 and the ‘MASK23’ field from bits 20 to 23. Bits 24 through 31 are reserved. When this feature is available, GDB will synthesize the ‘p0’ pseudo-register from ‘vpr’ contents. This feature must only be advertised if the target is M-profile. Advertising this feature for targets that are not M-profile may cause GDB to assume the target is M-profile when it isn't. If the ‘org.gnu.gdb.arm.vfp’ feature is available alongside the ‘org.gnu.gdb.arm.m-profile-mve’ feature, GDB will synthesize the ‘q’ pseudo-registers from ‘d’ register contents. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.5 XScale iwMMXt feature ............................. The XScale ‘org.gnu.gdb.xscale.iwmmxt’ feature is optional. If present, it must contain the following: − ‘wR0’ through ‘wR15’, registers with size 64 bits and a custom type ‘iwmmxt_vec64i’. ‘iwmmxt_vec64i’ is a union of four other types: ‘uint64’, a 2-element vector of ‘uint32’, a 4-element vector of ‘uint16’ and a 8-element vector of ‘uint8’. − ‘wCGR0’ through ‘wCGR3’, registers with size 32 bits and type ‘int’. The following registers are optional: − ‘wCID’, register with size of 32 bits and type ‘int’. − ‘wCon’, register with size 32 bits and type ‘int’. − ‘wCSSF’, register with size 32 bits and type ‘int’. − ‘wCASF’, register with size 32 bit and type ‘int’. This feature should only be reported if the target is XScale. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.6 Vector Floating-Point (VFP) feature ........................................... The ‘org.gnu.gdb.arm.vfp’ feature is optional. If present, it should contain one of two possible sets of values depending on whether VFP version 2 or VFP version 3 is in use. For VFP v2: − ‘d0’ through ‘d15’. The double-precision registers. They are 64 bits in size and have type ‘ieee_double’. − ‘fpscr’, the floating-point status and control register. It has a size of 32 bits and a type of ‘int’. For VFP v3: − ‘d0’ through ‘d31’. The double-precision registers. They are 64 bits in size and have type ‘ieee_double’. − ‘fpscr’, the floating-point status and control register. It has a size of 32 bits and a type of ‘int’. If this feature is available, GDB will synthesize the single-precision floating-point registers from halves of the double-precision registers as pseudo-registers. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.7 NEON architecture feature ................................. The ‘org.gnu.gdb.arm.neon’ feature is optional. It does not need to contain registers; it instructs GDB to display the VFP double-precision registers as vectors and to synthesize the quad-precision registers from pairs of double-precision registers. If this feature is present, ‘org.gnu.gdb.arm.vfp’ must also be present and include 32 double-precision registers. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.8 M-profile Pointer Authentication and Branch Target Identification feature ................................................................................. The ‘org.gnu.gdb.arm.m-profile-pacbti’ feature is optional, and acknowledges support for the ARMv8.1-m PACBTI extensions. This feature doesn't contain any required registers, and it only serves as a hint to GDB that the debugging stub supports the ARMv8.1-m PACBTI extensions. When GDB sees this feature, it will track return address signing states and will decorate backtraces using the [PAC] marker, similar to AArch64's PAC extension. *Note AArch64 PAC::. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.9 M-profile system registers feature .......................................... The ‘org.gnu.gdb.arm.m-system’ optional feature was introduced as a way to inform GDB about additional system registers. At the moment this feature must contain the following: − ‘msp’, the main stack pointer register. It is 32 bits in size with type ‘data_ptr’. − ‘psp’, the process stack pointer register. It is 32 bits in size with type ‘data_ptr’. This feature must only be advertised for M-profile targets. When GDB sees this feature, it will attempt to track the values of ‘msp’ and ‘psp’ across frames. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.10 M-profile Security Extensions feature .............................................. The ‘org.gnu.gdb.arm.secext’ optional feature was introduced so GDB could better support the switching of stack pointers and secure states in the Security Extensions. At the moment this feature must contain the following: − ‘msp_ns’, the main stack pointer register (non-secure state). It is 32 bits in size with type ‘data_ptr’. − ‘psp_ns’, the process stack pointer register (non-secure state). It is 32 bits in size with type ‘data_ptr’. − ‘msp_s’, the main stack pointer register (secure state). It is 32 bits in size with type ‘data_ptr’. − ‘psp_s’, the process stack pointer register (secure state). It is 32 bits in size with type ‘data_ptr’. When GDB sees this feature, it will attempt to track the values of all 4 stack pointers across secure state transitions, potentially improving unwinding when applications switch between security states. Extra registers are allowed in this feature, but they will not affect GDB. G.5.3.11 TLS registers feature .............................. The optional ‘org.gnu.gdb.arm.tls’ feature contains TLS registers. Currently it contains the following: − ‘tpidruro’, the user read-only thread id register. It is 32 bits in size and has type ‘data_ptr’. At the moment GDB looks for this feature, but doesn't do anything with it other than displaying it. Extra registers are allowed in this feature, but they will not affect GDB.  File: gdb.info, Node: i386 Features, Next: LoongArch Features, Prev: ARM Features, Up: Standard Target Features G.5.4 i386 Features ------------------- The ‘org.gnu.gdb.i386.core’ feature is required for i386/amd64 targets. It should describe the following registers: − ‘eax’ through ‘edi’ plus ‘eip’ for i386 − ‘rax’ through ‘r15’ plus ‘rip’ for amd64 − ‘eflags’, ‘cs’, ‘ss’, ‘ds’, ‘es’, ‘fs’, ‘gs’ − ‘st0’ through ‘st7’ − ‘fctrl’, ‘fstat’, ‘ftag’, ‘fiseg’, ‘fioff’, ‘foseg’, ‘fooff’ and ‘fop’ The register sets may be different, depending on the target. The ‘org.gnu.gdb.i386.sse’ feature is optional. It should describe registers: − ‘xmm0’ through ‘xmm7’ for i386 − ‘xmm0’ through ‘xmm15’ for amd64 − ‘mxcsr’ The ‘org.gnu.gdb.i386.avx’ feature is optional and requires the ‘org.gnu.gdb.i386.sse’ feature. It should describe the upper 128 bits of YMM registers: − ‘ymm0h’ through ‘ymm7h’ for i386 − ‘ymm0h’ through ‘ymm15h’ for amd64 The ‘org.gnu.gdb.i386.mpx’ is an optional feature representing Intel Memory Protection Extension (MPX). It should describe the following registers: − ‘bnd0raw’ through ‘bnd3raw’ for i386 and amd64. − ‘bndcfgu’ and ‘bndstatus’ for i386 and amd64. The ‘org.gnu.gdb.i386.linux’ feature is optional. It should describe a single register, ‘orig_eax’. The ‘org.gnu.gdb.i386.segments’ feature is optional. It should describe two system registers: ‘fs_base’ and ‘gs_base’. The ‘org.gnu.gdb.i386.avx512’ feature is optional and requires the ‘org.gnu.gdb.i386.avx’ feature. It should describe additional XMM registers: − ‘xmm16h’ through ‘xmm31h’, only valid for amd64. It should describe the upper 128 bits of additional YMM registers: − ‘ymm16h’ through ‘ymm31h’, only valid for amd64. It should describe the upper 256 bits of ZMM registers: − ‘zmm0h’ through ‘zmm7h’ for i386. − ‘zmm0h’ through ‘zmm15h’ for amd64. It should describe the additional ZMM registers: − ‘zmm16h’ through ‘zmm31h’, only valid for amd64. The ‘org.gnu.gdb.i386.pkeys’ feature is optional. It should describe a single register, ‘pkru’. It is a 32-bit register valid for i386 and amd64.  File: gdb.info, Node: LoongArch Features, Next: MicroBlaze Features, Prev: i386 Features, Up: Standard Target Features G.5.5 LoongArch Features ------------------------ The ‘org.gnu.gdb.loongarch.base’ feature is required for LoongArch targets. It should contain the registers ‘r0’ through ‘r31’, ‘pc’, and ‘badv’. Either the architectural names (‘r0’, ‘r1’, etc) can be used, or the ABI names (‘zero’, ‘ra’, etc). The ‘org.gnu.gdb.loongarch.fpu’ feature is optional. If present, it should contain registers ‘f0’ through ‘f31’, ‘fcc’, and ‘fcsr’.  File: gdb.info, Node: MicroBlaze Features, Next: MIPS Features, Prev: LoongArch Features, Up: Standard Target Features G.5.6 MicroBlaze Features ------------------------- The ‘org.gnu.gdb.microblaze.core’ feature is required for MicroBlaze targets. It should contain registers ‘r0’ through ‘r31’, ‘rpc’, ‘rmsr’, ‘rear’, ‘resr’, ‘rfsr’, ‘rbtr’, ‘rpvr’, ‘rpvr1’ through ‘rpvr11’, ‘redr’, ‘rpid’, ‘rzpr’, ‘rtlbx’, ‘rtlbsx’, ‘rtlblo’, and ‘rtlbhi’. The ‘org.gnu.gdb.microblaze.stack-protect’ feature is optional. If present, it should contain registers ‘rshr’ and ‘rslr’  File: gdb.info, Node: MIPS Features, Next: M68K Features, Prev: MicroBlaze Features, Up: Standard Target Features G.5.7 MIPS Features ------------------- The ‘org.gnu.gdb.mips.cpu’ feature is required for MIPS targets. It should contain registers ‘r0’ through ‘r31’, ‘lo’, ‘hi’, and ‘pc’. They may be 32-bit or 64-bit depending on the target. The ‘org.gnu.gdb.mips.cp0’ feature is also required. It should contain at least the ‘status’, ‘badvaddr’, and ‘cause’ registers. They may be 32-bit or 64-bit depending on the target. The ‘org.gnu.gdb.mips.fpu’ feature is currently required, though it may be optional in a future version of GDB. It should contain registers ‘f0’ through ‘f31’, ‘fcsr’, and ‘fir’. They may be 32-bit or 64-bit depending on the target. The ‘org.gnu.gdb.mips.dsp’ feature is optional. It should contain registers ‘hi1’ through ‘hi3’, ‘lo1’ through ‘lo3’, and ‘dspctl’. The ‘dspctl’ register should be 32-bit and the rest may be 32-bit or 64-bit depending on the target. The ‘org.gnu.gdb.mips.linux’ feature is optional. It should contain a single register, ‘restart’, which is used by the Linux kernel to control restartable syscalls.  File: gdb.info, Node: M68K Features, Next: NDS32 Features, Prev: MIPS Features, Up: Standard Target Features G.5.8 M68K Features ------------------- ‘‘org.gnu.gdb.m68k.core’’ ‘‘org.gnu.gdb.coldfire.core’’ ‘‘org.gnu.gdb.fido.core’’ One of those features must be always present. The feature that is present determines which flavor of m68k is used. The feature that is present should contain registers ‘d0’ through ‘d7’, ‘a0’ through ‘a5’, ‘fp’, ‘sp’, ‘ps’ and ‘pc’. ‘‘org.gnu.gdb.coldfire.fp’’ This feature is optional. If present, it should contain registers ‘fp0’ through ‘fp7’, ‘fpcontrol’, ‘fpstatus’ and ‘fpiaddr’. Note that, despite the fact that this feature's name says ‘coldfire’, it is used to describe any floating point registers. The size of the registers must match the main m68k flavor; so, for example, if the primary feature is reported as ‘coldfire’, then 64-bit floating point registers are required.  File: gdb.info, Node: NDS32 Features, Next: Nios II Features, Prev: M68K Features, Up: Standard Target Features G.5.9 NDS32 Features -------------------- The ‘org.gnu.gdb.nds32.core’ feature is required for NDS32 targets. It should contain at least registers ‘r0’ through ‘r10’, ‘r15’, ‘fp’, ‘gp’, ‘lp’, ‘sp’, and ‘pc’. The ‘org.gnu.gdb.nds32.fpu’ feature is optional. If present, it should contain 64-bit double-precision floating-point registers ‘fd0’ through _fdN_, which should be ‘fd3’, ‘fd7’, ‘fd15’, or ‘fd31’ based on the FPU configuration implemented. _Note:_ The first sixteen 64-bit double-precision floating-point registers are overlapped with the thirty-two 32-bit single-precision floating-point registers. The 32-bit single-precision registers, if not being listed explicitly, will be synthesized from halves of the overlapping 64-bit double-precision registers. Listing 32-bit single-precision registers explicitly is deprecated, and the support to it could be totally removed some day.  File: gdb.info, Node: Nios II Features, Next: OpenRISC 1000 Features, Prev: NDS32 Features, Up: Standard Target Features G.5.10 Nios II Features ----------------------- The ‘org.gnu.gdb.nios2.cpu’ feature is required for Nios II targets. It should contain the 32 core registers (‘zero’, ‘at’, ‘r2’ through ‘r23’, ‘et’ through ‘ra’), ‘pc’, and the 16 control registers (‘status’ through ‘mpuacc’).  File: gdb.info, Node: OpenRISC 1000 Features, Next: PowerPC Features, Prev: Nios II Features, Up: Standard Target Features G.5.11 Openrisc 1000 Features ----------------------------- The ‘org.gnu.gdb.or1k.group0’ feature is required for OpenRISC 1000 targets. It should contain the 32 general purpose registers (‘r0’ through ‘r31’), ‘ppc’, ‘npc’ and ‘sr’.  File: gdb.info, Node: PowerPC Features, Next: RISC-V Features, Prev: OpenRISC 1000 Features, Up: Standard Target Features G.5.12 PowerPC Features ----------------------- The ‘org.gnu.gdb.power.core’ feature is required for PowerPC targets. It should contain registers ‘r0’ through ‘r31’, ‘pc’, ‘msr’, ‘cr’, ‘lr’, ‘ctr’, and ‘xer’. They may be 32-bit or 64-bit depending on the target. The ‘org.gnu.gdb.power.fpu’ feature is optional. It should contain registers ‘f0’ through ‘f31’ and ‘fpscr’. The ‘org.gnu.gdb.power.altivec’ feature is optional. It should contain registers ‘vr0’ through ‘vr31’, ‘vscr’, and ‘vrsave’. GDB will define pseudo-registers ‘v0’ through ‘v31’ as aliases for the corresponding ‘vrX’ registers. The ‘org.gnu.gdb.power.vsx’ feature is optional. It should contain registers ‘vs0h’ through ‘vs31h’. GDB will combine these registers with the floating point registers (‘f0’ through ‘f31’) and the altivec registers (‘vr0’ through ‘vr31’) to present the 128-bit wide registers ‘vs0’ through ‘vs63’, the set of vector-scalar registers for POWER7. Therefore, this feature requires both ‘org.gnu.gdb.power.fpu’ and ‘org.gnu.gdb.power.altivec’. The ‘org.gnu.gdb.power.spe’ feature is optional. It should contain registers ‘ev0h’ through ‘ev31h’, ‘acc’, and ‘spefscr’. SPE targets should provide 32-bit registers in ‘org.gnu.gdb.power.core’ and provide the upper halves in ‘ev0h’ through ‘ev31h’. GDB will combine these to present registers ‘ev0’ through ‘ev31’ to the user. The ‘org.gnu.gdb.power.ppr’ feature is optional. It should contain the 64-bit register ‘ppr’. The ‘org.gnu.gdb.power.dscr’ feature is optional. It should contain the 64-bit register ‘dscr’. The ‘org.gnu.gdb.power.tar’ feature is optional. It should contain the 64-bit register ‘tar’. The ‘org.gnu.gdb.power.ebb’ feature is optional. It should contain registers ‘bescr’, ‘ebbhr’ and ‘ebbrr’, all 64-bit wide. The ‘org.gnu.gdb.power.linux.pmu’ feature is optional. It should contain registers ‘mmcr0’, ‘mmcr2’, ‘siar’, ‘sdar’ and ‘sier’, all 64-bit wide. This is the subset of the isa 2.07 server PMU registers provided by GNU/Linux. The ‘org.gnu.gdb.power.htm.spr’ feature is optional. It should contain registers ‘tfhar’, ‘texasr’ and ‘tfiar’, all 64-bit wide. The ‘org.gnu.gdb.power.htm.core’ feature is optional. It should contain the checkpointed general-purpose registers ‘cr0’ through ‘cr31’, as well as the checkpointed registers ‘clr’ and ‘cctr’. These registers may all be either 32-bit or 64-bit depending on the target. It should also contain the checkpointed registers ‘ccr’ and ‘cxer’, which should both be 32-bit wide. The ‘org.gnu.gdb.power.htm.fpu’ feature is optional. It should contain the checkpointed 64-bit floating-point registers ‘cf0’ through ‘cf31’, as well as the checkpointed 64-bit register ‘cfpscr’. The ‘org.gnu.gdb.power.htm.altivec’ feature is optional. It should contain the checkpointed altivec registers ‘cvr0’ through ‘cvr31’, all 128-bit wide. It should also contain the checkpointed registers ‘cvscr’ and ‘cvrsave’, both 32-bit wide. The ‘org.gnu.gdb.power.htm.vsx’ feature is optional. It should contain registers ‘cvs0h’ through ‘cvs31h’. GDB will combine these registers with the checkpointed floating point registers (‘cf0’ through ‘cf31’) and the checkpointed altivec registers (‘cvr0’ through ‘cvr31’) to present the 128-bit wide checkpointed vector-scalar registers ‘cvs0’ through ‘cvs63’. Therefore, this feature requires both ‘org.gnu.gdb.power.htm.altivec’ and ‘org.gnu.gdb.power.htm.fpu’. The ‘org.gnu.gdb.power.htm.ppr’ feature is optional. It should contain the 64-bit checkpointed register ‘cppr’. The ‘org.gnu.gdb.power.htm.dscr’ feature is optional. It should contain the 64-bit checkpointed register ‘cdscr’. The ‘org.gnu.gdb.power.htm.tar’ feature is optional. It should contain the 64-bit checkpointed register ‘ctar’.  File: gdb.info, Node: RISC-V Features, Next: RX Features, Prev: PowerPC Features, Up: Standard Target Features G.5.13 RISC-V Features ---------------------- The ‘org.gnu.gdb.riscv.cpu’ feature is required for RISC-V targets. It should contain the registers ‘x0’ through ‘x31’, and ‘pc’. Either the architectural names (‘x0’, ‘x1’, etc) can be used, or the ABI names (‘zero’, ‘ra’, etc). The ‘org.gnu.gdb.riscv.fpu’ feature is optional. If present, it should contain registers ‘f0’ through ‘f31’, ‘fflags’, ‘frm’, and ‘fcsr’. As with the cpu feature, either the architectural register names, or the ABI names can be used. The ‘org.gnu.gdb.riscv.virtual’ feature is optional. If present, it should contain registers that are not backed by real registers on the target, but are instead virtual, where the register value is derived from other target state. In many ways these are like GDBs pseudo-registers, except implemented by the target. Currently the only register expected in this set is the one byte ‘priv’ register that contains the target's privilege level in the least significant two bits. The ‘org.gnu.gdb.riscv.csr’ feature is optional. If present, it should contain all of the target's standard CSRs. Standard CSRs are those defined in the RISC-V specification documents. There is some overlap between this feature and the fpu feature; the ‘fflags’, ‘frm’, and ‘fcsr’ registers could be in either feature. The expectation is that these registers will be in the fpu feature if the target has floating point hardware, but can be moved into the csr feature if the target has the floating point control registers, but no other floating point hardware. The ‘org.gnu.gdb.riscv.vector’ feature is optional. If present, it should contain registers ‘v0’ through ‘v31’, all of which must be the same size.  File: gdb.info, Node: RX Features, Next: S/390 and System z Features, Prev: RISC-V Features, Up: Standard Target Features G.5.14 RX Features ------------------ The ‘org.gnu.gdb.rx.core’ feature is required for RX targets. It should contain the registers ‘r0’ through ‘r15’, ‘usp’, ‘isp’, ‘psw’, ‘pc’, ‘intb’, ‘bpsw’, ‘bpc’, ‘fintv’, ‘fpsw’, and ‘acc’.  File: gdb.info, Node: S/390 and System z Features, Next: Sparc Features, Prev: RX Features, Up: Standard Target Features G.5.15 S/390 and System z Features ---------------------------------- The ‘org.gnu.gdb.s390.core’ feature is required for S/390 and System z targets. It should contain the PSW and the 16 general registers. In particular, System z targets should provide the 64-bit registers ‘pswm’, ‘pswa’, and ‘r0’ through ‘r15’. S/390 targets should provide the 32-bit versions of these registers. A System z target that runs in 31-bit addressing mode should provide 32-bit versions of ‘pswm’ and ‘pswa’, as well as the general register's upper halves ‘r0h’ through ‘r15h’, and their lower halves ‘r0l’ through ‘r15l’. The ‘org.gnu.gdb.s390.fpr’ feature is required. It should contain the 64-bit registers ‘f0’ through ‘f15’, and ‘fpc’. The ‘org.gnu.gdb.s390.acr’ feature is required. It should contain the 32-bit registers ‘acr0’ through ‘acr15’. The ‘org.gnu.gdb.s390.linux’ feature is optional. It should contain the register ‘orig_r2’, which is 64-bit wide on System z targets and 32-bit otherwise. In addition, the feature may contain the ‘last_break’ register, whose width depends on the addressing mode, as well as the ‘system_call’ register, which is always 32-bit wide. The ‘org.gnu.gdb.s390.tdb’ feature is optional. It should contain the 64-bit registers ‘tdb0’, ‘tac’, ‘tct’, ‘atia’, and ‘tr0’ through ‘tr15’. The ‘org.gnu.gdb.s390.vx’ feature is optional. It should contain 64-bit wide registers ‘v0l’ through ‘v15l’, which will be combined by GDB with the floating point registers ‘f0’ through ‘f15’ to present the 128-bit wide vector registers ‘v0’ through ‘v15’. In addition, this feature should contain the 128-bit wide vector registers ‘v16’ through ‘v31’. The ‘org.gnu.gdb.s390.gs’ feature is optional. It should contain the 64-bit wide guarded-storage-control registers ‘gsd’, ‘gssm’, and ‘gsepla’. The ‘org.gnu.gdb.s390.gsbc’ feature is optional. It should contain the 64-bit wide guarded-storage broadcast control registers ‘bc_gsd’, ‘bc_gssm’, and ‘bc_gsepla’.  File: gdb.info, Node: Sparc Features, Next: TIC6x Features, Prev: S/390 and System z Features, Up: Standard Target Features G.5.16 Sparc Features --------------------- The ‘org.gnu.gdb.sparc.cpu’ feature is required for sparc32/sparc64 targets. It should describe the following registers: − ‘g0’ through ‘g7’ − ‘o0’ through ‘o7’ − ‘l0’ through ‘l7’ − ‘i0’ through ‘i7’ They may be 32-bit or 64-bit depending on the target. Also the ‘org.gnu.gdb.sparc.fpu’ feature is required for sparc32/sparc64 targets. It should describe the following registers: − ‘f0’ through ‘f31’ − ‘f32’ through ‘f62’ for sparc64 The ‘org.gnu.gdb.sparc.cp0’ feature is required for sparc32/sparc64 targets. It should describe the following registers: − ‘y’, ‘psr’, ‘wim’, ‘tbr’, ‘pc’, ‘npc’, ‘fsr’, and ‘csr’ for sparc32 − ‘pc’, ‘npc’, ‘state’, ‘fsr’, ‘fprs’, and ‘y’ for sparc64  File: gdb.info, Node: TIC6x Features, Prev: Sparc Features, Up: Standard Target Features G.5.17 TMS320C6x Features ------------------------- The ‘org.gnu.gdb.tic6x.core’ feature is required for TMS320C6x targets. It should contain registers ‘A0’ through ‘A15’, registers ‘B0’ through ‘B15’, ‘CSR’ and ‘PC’. The ‘org.gnu.gdb.tic6x.gp’ feature is optional. It should contain registers ‘A16’ through ‘A31’ and ‘B16’ through ‘B31’. The ‘org.gnu.gdb.tic6x.c6xp’ feature is optional. It should contain registers ‘TSR’, ‘ILC’ and ‘RILC’.  File: gdb.info, Node: Operating System Information, Next: Trace File Format, Prev: Target Descriptions, Up: Top Appendix H Operating System Information *************************************** Users of GDB often wish to obtain information about the state of the operating system running on the target--for example the list of processes, or the list of open files. This section describes the mechanism that makes it possible. This mechanism is similar to the target features mechanism (*note Target Descriptions::), but focuses on a different aspect of target. Operating system information is retrieved from the target via the remote protocol, using ‘qXfer’ requests (*note qXfer osdata read::). The object name in the request should be ‘osdata’, and the ANNEX identifies the data to be fetched. * Menu: * Process list::  File: gdb.info, Node: Process list, Up: Operating System Information H.1 Process list ================ When requesting the process list, the ANNEX field in the ‘qXfer’ request should be ‘processes’. The returned data is an XML document. The formal syntax of this document is defined in ‘gdb/features/osdata.dtd’. An example document is: 1 root /sbin/init 1,2,3 Each item should include a column whose name is ‘pid’. The value of that column should identify the process on the target. The ‘user’ and ‘command’ columns are optional, and will be displayed by GDB. The ‘cores’ column, if present, should contain a comma-separated list of cores that this process is running on. Target may provide additional columns, which GDB currently ignores.  File: gdb.info, Node: Trace File Format, Next: Index Section Format, Prev: Operating System Information, Up: Top Appendix I Trace File Format **************************** The trace file comes in three parts: a header, a textual description section, and a trace frame section with binary data. The header has the form ‘\x7fTRACE0\n’. The first byte is ‘0x7f’ so as to indicate that the file contains binary data, while the ‘0’ is a version number that may have different values in the future. The description section consists of multiple lines of ASCII text separated by newline characters (‘0xa’). The lines may include a variety of optional descriptive or context-setting information, such as tracepoint definitions or register set size. GDB will ignore any line that it does not recognize. An empty line marks the end of this section. ‘R SIZE’ Specifies the size of a register block in bytes. This is equal to the size of a ‘g’ packet payload in the remote protocol. SIZE is an ascii decimal number. There should be only one such line in a single trace file. ‘status STATUS’ Trace status. STATUS has the same format as a ‘qTStatus’ remote packet reply. There should be only one such line in a single trace file. ‘tp PAYLOAD’ Tracepoint definition. The PAYLOAD has the same format as ‘qTfP’/‘qTsP’ remote packet reply payload. A single tracepoint may take multiple lines of definition, corresponding to the multiple reply packets. ‘tsv PAYLOAD’ Trace state variable definition. The PAYLOAD has the same format as ‘qTfV’/‘qTsV’ remote packet reply payload. A single variable may take multiple lines of definition, corresponding to the multiple reply packets. ‘tdesc PAYLOAD’ Target description in XML format. The PAYLOAD is a single line of the XML file. All such lines should be concatenated together to get the original XML file. This file is in the same format as ‘qXfer’ ‘features’ payload, and corresponds to the main ‘target.xml’ file. Includes are not allowed. The trace frame section consists of a number of consecutive frames. Each frame begins with a two-byte tracepoint number, followed by a four-byte size giving the amount of data in the frame. The data in the frame consists of a number of blocks, each introduced by a character indicating its type (at least register, memory, and trace state variable). The data in this section is raw binary, not a hexadecimal or other encoding; its endianness matches the target's endianness. ‘R BYTES’ Register block. The number and ordering of bytes matches that of a ‘g’ packet in the remote protocol. Note that these are the actual bytes, in target order, not a hexadecimal encoding. ‘M ADDRESS LENGTH BYTES...’ Memory block. This is a contiguous block of memory, at the 8-byte address ADDRESS, with a 2-byte length LENGTH, followed by LENGTH bytes. ‘V NUMBER VALUE’ Trace state variable block. This records the 8-byte signed value VALUE of trace state variable numbered NUMBER. Future enhancements of the trace file format may include additional types of blocks.  File: gdb.info, Node: Index Section Format, Next: Debuginfod, Prev: Trace File Format, Up: Top Appendix J ‘.gdb_index’ section format ************************************** This section documents the index section that is created by ‘save gdb-index’ (*note Index Files::). The index section is DWARF-specific; some knowledge of DWARF is assumed in this description. The mapped index file format is designed to be directly ‘mmap’able on any architecture. In most cases, a datum is represented using a little-endian 32-bit integer value, called an ‘offset_type’. Big endian machines must byte-swap the values before using them. Exceptions to this rule are noted. The data is laid out such that alignment is always respected. A mapped index consists of several areas, laid out in order. 1. The file header. This is a sequence of values, of ‘offset_type’ unless otherwise noted: 1. The version number, currently 9. Versions 1, 2 and 3 are obsolete. Version 4 uses a different hashing function from versions 5 and 6. Version 6 includes symbols for inlined functions, whereas versions 4 and 5 do not. Version 7 adds attributes to the CU indices in the symbol table. Version 8 specifies that symbols from DWARF type units (‘DW_TAG_type_unit’) refer to the type unit's symbol table and not the compilation unit (‘DW_TAG_comp_unit’) using the type. Version 9 adds the name and the language of the main function to the index. GDB will only read version 4, 5, or 6 indices by specifying ‘set use-deprecated-index-sections on’. GDB has a workaround for potentially broken version 7 indices so it is currently not flagged as deprecated. 2. The offset, from the start of the file, of the CU list. 3. The offset, from the start of the file, of the types CU list. Note that this area can be empty, in which case this offset will be equal to the next offset. 4. The offset, from the start of the file, of the address area. 5. The offset, from the start of the file, of the symbol table. 6. The offset, from the start of the file, of the shortcut table. 7. The offset, from the start of the file, of the constant pool. 2. The CU list. This is a sequence of pairs of 64-bit little-endian values, sorted by the CU offset. The first element in each pair is the offset of a CU in the ‘.debug_info’ section. The second element in each pair is the length of that CU. References to a CU elsewhere in the map are done using a CU index, which is just the 0-based index into this table. Note that if there are type CUs, then conceptually CUs and type CUs form a single list for the purposes of CU indices. 3. The types CU list. This is a sequence of triplets of 64-bit little-endian values. In a triplet, the first value is the CU offset, the second value is the type offset in the CU, and the third value is the type signature. The types CU list is not sorted. 4. The address area. The address area consists of a sequence of address entries. Each address entry has three elements: 1. The low address. This is a 64-bit little-endian value. 2. The high address. This is a 64-bit little-endian value. Like ‘DW_AT_high_pc’, the value is one byte beyond the end. 3. The CU index. This is an ‘offset_type’ value. 5. The symbol table. This is an open-addressed hash table. The size of the hash table is always a power of 2. Each slot in the hash table consists of a pair of ‘offset_type’ values. The first value is the offset of the symbol's name in the constant pool. The second value is the offset of the CU vector in the constant pool. If both values are 0, then this slot in the hash table is empty. This is ok because while 0 is a valid constant pool index, it cannot be a valid index for both a string and a CU vector. The hash value for a table entry is computed by applying an iterative hash function to the symbol's name. Starting with an initial value of ‘r = 0’, each (unsigned) character ‘c’ in the string is incorporated into the hash using the formula depending on the index version: Version 4 The formula is ‘r = r * 67 + c - 113’. Versions 5 to 7 The formula is ‘r = r * 67 + tolower (c) - 113’. The terminating ‘\0’ is not incorporated into the hash. The step size used in the hash table is computed via ‘((hash * 17) & (size - 1)) | 1’, where ‘hash’ is the hash value, and ‘size’ is the size of the hash table. The step size is used to find the next candidate slot when handling a hash collision. The names of C++ symbols in the hash table are canonicalized. We don't currently have a simple description of the canonicalization algorithm; if you intend to create new index sections, you must read the code. 6. The shortcut table This is a data structure with the following fields: Language of main An ‘offset_type’ value indicating the language of the main function as a ‘DW_LANG_’ constant. This value will be zero if main function information is not present. Name of main An ‘offset_type’ value indicating the offset of the main function's name in the constant pool. This value must be ignored if the value for the language of main is zero. 7. The constant pool. This is simply a bunch of bytes. It is organized so that alignment is correct: CU vectors are stored first, followed by strings. A CU vector in the constant pool is a sequence of ‘offset_type’ values. The first value is the number of CU indices in the vector. Each subsequent value is the index and symbol attributes of a CU in the CU list. This element in the hash table is used to indicate which CUs define the symbol and how the symbol is used. See below for the format of each CU index+attributes entry. A string in the constant pool is zero-terminated. Attributes were added to CU index values in ‘.gdb_index’ version 7. If a symbol has multiple uses within a CU then there is one CU index+attributes value for each use. The format of each CU index+attributes entry is as follows (bit 0 = LSB): Bits 0-23 This is the index of the CU in the CU list. Bits 24-27 These bits are reserved for future purposes and must be zero. Bits 28-30 The kind of the symbol in the CU. 0 This value is reserved and should not be used. By reserving zero the full ‘offset_type’ value is backwards compatible with previous versions of the index. 1 The symbol is a type. 2 The symbol is a variable or an enum value. 3 The symbol is a function. 4 Any other kind of symbol. 5,6,7 These values are reserved. Bit 31 This bit is zero if the value is global and one if it is static. The determination of whether a symbol is global or static is complicated. The authoritative reference is the file ‘dwarf2read.c’ in GDB sources. This pseudo-code describes the computation of a symbol's kind and global/static attributes in the index. is_external = get_attribute (die, DW_AT_external); language = get_attribute (cu_die, DW_AT_language); switch (die->tag) { case DW_TAG_typedef: case DW_TAG_base_type: case DW_TAG_subrange_type: kind = TYPE; is_static = 1; break; case DW_TAG_enumerator: kind = VARIABLE; is_static = language != CPLUS; break; case DW_TAG_subprogram: kind = FUNCTION; is_static = ! (is_external || language == ADA); break; case DW_TAG_constant: kind = VARIABLE; is_static = ! is_external; break; case DW_TAG_variable: kind = VARIABLE; is_static = ! is_external; break; case DW_TAG_namespace: kind = TYPE; is_static = 0; break; case DW_TAG_class_type: case DW_TAG_interface_type: case DW_TAG_structure_type: case DW_TAG_union_type: case DW_TAG_enumeration_type: kind = TYPE; is_static = language != CPLUS; break; default: assert (0); }  File: gdb.info, Node: Debuginfod, Next: Man Pages, Prev: Index Section Format, Up: Top Appendix K Download debugging resources with Debuginfod ******************************************************* ‘debuginfod’ is an HTTP server for distributing ELF, DWARF and source files. With the ‘debuginfod’ client library, ‘libdebuginfod’, GDB can query servers using the build IDs associated with missing debug info, executables and source files in order to download them on demand. For instructions on building GDB with ‘libdebuginfod’, *note -with-debuginfod: Configure Options. ‘debuginfod’ is packaged with ‘elfutils’, starting with version 0.178. See for more information regarding ‘debuginfod’. * Menu: * Debuginfod Settings:: Configuring debuginfod with GDB  File: gdb.info, Node: Debuginfod Settings, Up: Debuginfod K.1 Debuginfod Settings ======================= GDB provides the following commands for configuring ‘debuginfod’. ‘set debuginfod enabled’ ‘set debuginfod enabled on’ GDB may query ‘debuginfod’ servers for missing debug info and source files. GDB may also download individual ELF/DWARF sections such as ‘.gdb_index’ to help reduce the total amount of data downloaded from ‘debuginfod’ servers; this can be controlled by ‘maint set debuginfod download-sections’ (*note maint set debuginfod download-sections: Maintenance Commands.). ‘set debuginfod enabled off’ GDB will not attempt to query ‘debuginfod’ servers when missing debug info or source files. By default, ‘debuginfod enabled’ is set to ‘off’ for non-interactive sessions. ‘set debuginfod enabled ask’ GDB will prompt the user to enable or disable ‘debuginfod’ before attempting to perform the next query. By default, ‘debuginfod enabled’ is set to ‘ask’ for interactive sessions. ‘show debuginfod enabled’ Display whether ‘debuginfod enabled’ is set to ‘on’, ‘off’ or ‘ask’. ‘set debuginfod urls’ ‘set debuginfod urls URLS’ Set the space-separated list of URLs that ‘debuginfod’ will attempt to query. Only ‘http://’, ‘https://’ and ‘file://’ protocols should be used. The default value of ‘debuginfod urls’ is copied from the DEBUGINFOD_URLS environment variable. ‘show debuginfod urls’ Display the list of URLs that ‘debuginfod’ will attempt to query. ‘set debuginfod verbose’ ‘set debuginfod verbose N’ Enable or disable ‘debuginfod’-related output. Use a non-zero value to enable and ‘0’ to disable. ‘debuginfod’ output is shown by default. ‘show debuginfod verbose’ Show the current verbosity setting.  File: gdb.info, Node: Man Pages, Next: Copying, Prev: Debuginfod, Up: Top Appendix L Manual pages *********************** * Menu: * gdb man:: The GNU Debugger man page * gdbserver man:: Remote Server for the GNU Debugger man page * gcore man:: Generate a core file of a running program * gdbinit man:: gdbinit scripts * gdb-add-index man:: Add index files to speed up GDB  File: gdb.info, Node: gdb man, Next: gdbserver man, Up: Man Pages gdb man ======= gdb [OPTIONS] [PROG|PROG PROCID|PROG CORE] The purpose of a debugger such as GDB is to allow you to see what is going on "inside" another program while it executes - or what another program was doing at the moment it crashed. GDB can do four main kinds of things (plus other things in support of these) to help you catch bugs in the act: • Start your program, specifying anything that might affect its behavior. • Make your program stop on specified conditions. • Examine what has happened, when your program has stopped. • Change things in your program, so you can experiment with correcting the effects of one bug and go on to learn about another. You can use GDB to debug programs written in C, C++, Fortran and Modula-2. GDB is invoked with the shell command ‘gdb’. Once started, it reads commands from the terminal until you tell it to exit with the GDB command ‘quit’ or ‘exit’. You can get online help from GDB itself by using the command ‘help’. You can run ‘gdb’ with no arguments or options; but the most usual way to start GDB is with one argument or two, specifying an executable program as the argument: gdb program You can also start with both an executable program and a core file specified: gdb program core You can, instead, specify a process ID as a second argument or use option ‘-p’, if you want to debug a running process: gdb program 1234 gdb -p 1234 would attach GDB to process ‘1234’. With option ‘-p’ you can omit the PROGRAM filename. Here are some of the most frequently needed GDB commands: ‘break [FILE:][FUNCTION|LINE]’ Set a breakpoint at FUNCTION or LINE (in FILE). ‘run [ARGLIST]’ Start your program (with ARGLIST, if specified). ‘bt’ Backtrace: display the program stack. ‘print EXPR’ Display the value of an expression. ‘c’ Continue running your program (after stopping, e.g. at a breakpoint). ‘next’ Execute next program line (after stopping); step _over_ any function calls in the line. ‘edit [FILE:]FUNCTION’ look at the program line where it is presently stopped. ‘list [FILE:]FUNCTION’ type the text of the program in the vicinity of where it is presently stopped. ‘step’ Execute next program line (after stopping); step _into_ any function calls in the line. ‘help [NAME]’ Show information about GDB command NAME, or general information about using GDB. ‘quit’ ‘exit’ Exit from GDB. Any arguments other than options specify an executable file and core file (or process ID); that is, the first argument encountered with no associated option flag is equivalent to a ‘--se’ option, and the second, if any, is equivalent to a ‘-c’ option if it's the name of a file. Many options have both long and abbreviated forms; both are shown here. The long forms are also recognized if you truncate them, so long as enough of the option is present to be unambiguous. The abbreviated forms are shown here with ‘-’ and long forms are shown with ‘--’ to reflect how they are shown in ‘--help’. However, GDB recognizes all of the following conventions for most options: ‘--option=VALUE’ ‘--option VALUE’ ‘-option=VALUE’ ‘-option VALUE’ ‘--o=VALUE’ ‘--o VALUE’ ‘-o=VALUE’ ‘-o VALUE’ All the options and command line arguments you give are processed in sequential order. The order makes a difference when the ‘-x’ option is used. ‘--help’ ‘-h’ List all options, with brief explanations. ‘--symbols=FILE’ ‘-s FILE’ Read symbol table from FILE. ‘--write’ Enable writing into executable and core files. ‘--exec=FILE’ ‘-e FILE’ Use FILE as the executable file to execute when appropriate, and for examining pure data in conjunction with a core dump. ‘--se=FILE’ Read symbol table from FILE and use it as the executable file. ‘--core=FILE’ ‘-c FILE’ Use FILE as a core dump to examine. ‘--command=FILE’ ‘-x FILE’ Execute GDB commands from FILE. ‘--eval-command=COMMAND’ ‘-ex COMMAND’ Execute given GDB COMMAND. ‘--init-eval-command=COMMAND’ ‘-iex’ Execute GDB COMMAND before loading the inferior. ‘--directory=DIRECTORY’ ‘-d DIRECTORY’ Add DIRECTORY to the path to search for source files. ‘--nh’ Do not execute commands from ‘~/.config/gdb/gdbinit’, ‘~/.gdbinit’, ‘~/.config/gdb/gdbearlyinit’, or ‘~/.gdbearlyinit’ ‘--nx’ ‘-n’ Do not execute commands from any ‘.gdbinit’ or ‘.gdbearlyinit’ initialization files. ‘--quiet’ ‘--silent’ ‘-q’ "Quiet". Do not print the introductory and copyright messages. These messages are also suppressed in batch mode. ‘--batch’ Run in batch mode. Exit with status ‘0’ after processing all the command files specified with ‘-x’ (and ‘.gdbinit’, if not inhibited). Exit with nonzero status if an error occurs in executing the GDB commands in the command files. Batch mode may be useful for running GDB as a filter, for example to download and run a program on another computer; in order to make this more useful, the message Program exited normally. (which is ordinarily issued whenever a program running under GDB control terminates) is not issued when running in batch mode. ‘--batch-silent’ Run in batch mode, just like ‘--batch’, but totally silent. All GDB output is suppressed (stderr is unaffected). This is much quieter than ‘--silent’ and would be useless for an interactive session. This is particularly useful when using targets that give ‘Loading section’ messages, for example. Note that targets that give their output via GDB, as opposed to writing directly to ‘stdout’, will also be made silent. ‘--args PROG [ARGLIST]’ Change interpretation of command line so that arguments following this option are passed as arguments to the inferior. As an example, take the following command: gdb ./a.out -q It would start GDB with ‘-q’, not printing the introductory message. On the other hand, using: gdb --args ./a.out -q starts GDB with the introductory message, and passes the option to the inferior. ‘--pid=PID’ Attach GDB to an already running program, with the PID PID. ‘--tui’ Open the terminal user interface. ‘--readnow’ Read all symbols from the given symfile on the first access. ‘--readnever’ Do not read symbol files. ‘--return-child-result’ GDB's exit code will be the same as the child's exit code. ‘--configuration’ Print details about GDB configuration and then exit. ‘--version’ Print version information and then exit. ‘--cd=DIRECTORY’ Run GDB using DIRECTORY as its working directory, instead of the current directory. ‘--data-directory=DIRECTORY’ ‘-D’ Run GDB using DIRECTORY as its data directory. The data directory is where GDB searches for its auxiliary files. ‘--fullname’ ‘-f’ Emacs sets this option when it runs GDB as a subprocess. It tells GDB to output the full file name and line number in a standard, recognizable fashion each time a stack frame is displayed (which includes each time the program stops). This recognizable format looks like two ‘\032’ characters, followed by the file name, line number and character position separated by colons, and a newline. The Emacs-to-GDB interface program uses the two ‘\032’ characters as a signal to display the source code for the frame. ‘-b BAUDRATE’ Set the line speed (baud rate or bits per second) of any serial interface used by GDB for remote debugging. ‘-l TIMEOUT’ Set timeout, in seconds, for remote debugging. ‘--tty=DEVICE’ Run using DEVICE for your program's standard input and output.  File: gdb.info, Node: gdbserver man, Next: gcore man, Prev: gdb man, Up: Man Pages gdbserver man ============= gdbserver COMM PROG [ARGS...] gdbserver -attach COMM PID gdbserver -multi COMM ‘gdbserver’ is a program that allows you to run GDB on a different machine than the one which is running the program being debugged. Usage (server (target) side) ---------------------------- First, you need to have a copy of the program you want to debug put onto the target system. The program can be stripped to save space if needed, as ‘gdbserver’ doesn't care about symbols. All symbol handling is taken care of by the GDB running on the host system. To use the server, you log on to the target system, and run the ‘gdbserver’ program. You must tell it (a) how to communicate with GDB, (b) the name of your program, and (c) its arguments. The general syntax is: target> gdbserver COMM PROGRAM [ARGS ...] For example, using a serial port, you might say: target> gdbserver /dev/com1 emacs foo.txt This tells ‘gdbserver’ to debug emacs with an argument of foo.txt, and to communicate with GDB via ‘/dev/com1’. ‘gdbserver’ now waits patiently for the host GDB to communicate with it. To use a TCP connection, you could say: target> gdbserver host:2345 emacs foo.txt This says pretty much the same thing as the last example, except that we are going to communicate with the ‘host’ GDB via TCP. The ‘host:2345’ argument means that we are expecting to see a TCP connection from ‘host’ to local TCP port 2345. (Currently, the ‘host’ part is ignored.) You can choose any number you want for the port number as long as it does not conflict with any existing TCP ports on the target system. This same port number must be used in the host GDBs ‘target remote’ command, which will be described shortly. Note that if you chose a port number that conflicts with another service, ‘gdbserver’ will print an error message and exit. ‘gdbserver’ can also attach to running programs. This is accomplished via the ‘--attach’ argument. The syntax is: target> gdbserver --attach COMM PID PID is the process ID of a currently running process. It isn't necessary to point ‘gdbserver’ at a binary for the running process. To start ‘gdbserver’ without supplying an initial command to run or process ID to attach, use the ‘--multi’ command line option. In such case you should connect using ‘target extended-remote’ to start the program you want to debug. target> gdbserver --multi COMM Usage (host side) ----------------- You need an unstripped copy of the target program on your host system, since GDB needs to examine its symbol tables and such. Start up GDB as you normally would, with the target program as the first argument. (You may need to use the ‘--baud’ option if the serial line is running at anything except 9600 baud.) That is ‘gdb TARGET-PROG’, or ‘gdb --baud BAUD TARGET-PROG’. After that, the only new command you need to know about is ‘target remote’ (or ‘target extended-remote’). Its argument is either a device name (usually a serial device, like ‘/dev/ttyb’), or a ‘HOST:PORT’ descriptor. For example: (gdb) target remote /dev/ttyb communicates with the server via serial line ‘/dev/ttyb’, and: (gdb) target remote the-target:2345 communicates via a TCP connection to port 2345 on host 'the-target', where you previously started up ‘gdbserver’ with the same port number. Note that for TCP connections, you must start up ‘gdbserver’ prior to using the 'target remote' command, otherwise you may get an error that looks something like 'Connection refused'. ‘gdbserver’ can also debug multiple inferiors at once, described in *note Inferiors Connections and Programs::. In such case use the ‘extended-remote’ GDB command variant: (gdb) target extended-remote the-target:2345 The ‘gdbserver’ option ‘--multi’ may or may not be used in such case. There are three different modes for invoking ‘gdbserver’: • Debug a specific program specified by its program name: gdbserver COMM PROG [ARGS...] The COMM parameter specifies how should the server communicate with GDB; it is either a device name (to use a serial line), a TCP port number (‘:1234’), or ‘-’ or ‘stdio’ to use stdin/stdout of ‘gdbserver’. Specify the name of the program to debug in PROG. Any remaining arguments will be passed to the program verbatim. When the program exits, GDB will close the connection, and ‘gdbserver’ will exit. • Debug a specific program by specifying the process ID of a running program: gdbserver --attach COMM PID The COMM parameter is as described above. Supply the process ID of a running program in PID; GDB will do everything else. Like with the previous mode, when the process PID exits, GDB will close the connection, and ‘gdbserver’ will exit. • Multi-process mode - debug more than one program/process: gdbserver --multi COMM In this mode, GDB can instruct ‘gdbserver’ which command(s) to run. Unlike the other 2 modes, GDB will not close the connection when a process being debugged exits, so you can debug several processes in the same session. In each of the modes you may specify these options: ‘--help’ List all options, with brief explanations. ‘--version’ This option causes ‘gdbserver’ to print its version number and exit. ‘--attach’ ‘gdbserver’ will attach to a running program. The syntax is: target> gdbserver --attach COMM PID PID is the process ID of a currently running process. It isn't necessary to point ‘gdbserver’ at a binary for the running process. ‘--multi’ To start ‘gdbserver’ without supplying an initial command to run or process ID to attach, use this command line option. Then you can connect using ‘target extended-remote’ and start the program you want to debug. The syntax is: target> gdbserver --multi COMM ‘--debug[=option1,option2,...]’ Instruct ‘gdbserver’ to display extra status information about the debugging process. This option is intended for ‘gdbserver’ development and for bug reports to the developers. Each OPTION is the name of a component for which debugging should be enabled. The list of possible options is ‘all’, ‘threads’, ‘event-loop’, ‘remote’. The special option ‘all’ enables all components. The option list is processed left to right, and an option can be prefixed with the ‘-’ character to disable output for that component, so you could write: target> gdbserver --debug=all,-event-loop to turn on debug output for all components except ‘event-loop’. If no options are passed to ‘--debug’ then this is treated as equivalent to ‘--debug=threads’. This could change in future releases of ‘gdbserver’. ‘--debug-file=FILENAME’ Instruct ‘gdbserver’ to send any debug output to the given FILENAME. This option is intended for ‘gdbserver’ development and for bug reports to the developers. ‘--debug-format=option1[,option2,...]’ Instruct ‘gdbserver’ to include extra information in each line of debugging output. *Note Other Command-Line Arguments for gdbserver::. ‘--wrapper’ Specify a wrapper to launch programs for debugging. The option should be followed by the name of the wrapper, then any command-line arguments to pass to the wrapper, then ‘--’ indicating the end of the wrapper arguments. ‘--once’ By default, ‘gdbserver’ keeps the listening TCP port open, so that additional connections are possible. However, if you start ‘gdbserver’ with the ‘--once’ option, it will stop listening for any further connection attempts after connecting to the first GDB session.  File: gdb.info, Node: gcore man, Next: gdbinit man, Prev: gdbserver man, Up: Man Pages gcore ===== gcore [-a] [-o PREFIX] PID1 [PID2...PIDN] Generate core dumps of one or more running programs with process IDs PID1, PID2, etc. A core file produced by ‘gcore’ is equivalent to one produced by the kernel when the process crashes (and when ‘ulimit -c’ was used to set up an appropriate core dump limit). However, unlike after a crash, after ‘gcore’ finishes its job the program remains running without any change. ‘-a’ Dump all memory mappings. The actual effect of this option depends on the Operating System. On GNU/Linux, it will disable ‘use-coredump-filter’ (*note set use-coredump-filter::) and enable ‘dump-excluded-mappings’ (*note set dump-excluded-mappings::). ‘-o PREFIX’ The optional argument PREFIX specifies the prefix to be used when composing the file names of the core dumps. The file name is composed as ‘PREFIX.PID’, where PID is the process ID of the running program being analyzed by ‘gcore’. If not specified, PREFIX defaults to GCORE.  File: gdb.info, Node: gdbinit man, Next: gdb-add-index man, Prev: gcore man, Up: Man Pages gdbinit ======= ~/.config/gdb/gdbinit ~/.gdbinit ./.gdbinit These files contain GDB commands to automatically execute during GDB startup. The lines of contents are canned sequences of commands, described in *note Sequences::. Please read more in *note Startup::. ‘(not enabled with --with-system-gdbinit during compilation)’ System-wide initialization file. It is executed unless user specified GDB option ‘-nx’ or ‘-n’. See more in ‘(not enabled with --with-system-gdbinit-dir during compilation)’ System-wide initialization directory. All files in this directory are executed on startup unless user specified GDB option ‘-nx’ or ‘-n’, as long as they have a recognized file extension. See more in *note System-wide configuration::. ‘~/.config/gdb/gdbinit or ~/.gdbinit’ User initialization file. It is executed unless user specified GDB options ‘-nx’, ‘-n’ or ‘-nh’. ‘.gdbinit’ Initialization file for current directory. It may need to be enabled with GDB security command ‘set auto-load local-gdbinit’. See more in *note Init File in the Current Directory::.  File: gdb.info, Node: gdb-add-index man, Prev: gdbinit man, Up: Man Pages gdb-add-index ============= gdb-add-index FILENAME When GDB finds a symbol file, it scans the symbols in the file in order to construct an internal symbol table. This lets most GDB operations work quickly-at the cost of a delay early on. For large programs, this delay can be quite lengthy, so GDB provides a way to build an index, which speeds up startup. To determine whether a file contains such an index, use the command ‘readelf -S filename’: the index is stored in a section named ‘.gdb_index’. The index file can only be produced on systems which use ELF binaries and DWARF debug information (i.e., sections named ‘.debug_*’). ‘gdb-add-index’ uses GDB and ‘objdump’ found in the ‘PATH’ environment variable. If you want to use different versions of these programs, you can specify them through the ‘GDB’ and ‘OBJDUMP’ environment variables. See more in *note Index Files::.  File: gdb.info, Node: Copying, Next: GNU Free Documentation License, Prev: Man Pages, Up: Top Appendix M GNU GENERAL PUBLIC LICENSE ************************************* Version 3, 29 June 2007 Copyright © 2007 Free Software Foundation, Inc. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble ======== The GNU General Public License is a free, copyleft license for software and other kinds of works. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our software; it applies also to any other work released this way by its authors. You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things. To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. 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If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM). The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network. Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying. 7. Additional Terms. "Additional permissions" are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions. When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission. Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms: a. Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or b. Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or c. Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or d. Limiting the use for publicity purposes of names of licensors or authors of the material; or e. Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or f. Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors. All other non-permissive additional terms are considered "further restrictions" within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying. If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms. Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way. 8. Termination. You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11). However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10. 9. Acceptance Not Required for Having Copies. You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so. 10. Automatic Licensing of Downstream Recipients. Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License. An "entity transaction" is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts. You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it. 11. Patents. A "contributor" is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's "contributor version". A contributor's "essential patent claims" are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, "control" includes the right to grant patent sublicenses in a manner consistent with the requirements of this License. Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version. In the following three paragraphs, a "patent license" is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To "grant" such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party. If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. "Knowingly relying" means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid. If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it. A patent license is "discriminatory" if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007. Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. 12. No Surrender of Others' Freedom. If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program. 13. Use with the GNU Affero General Public License. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such. 14. Revised Versions of this License. The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation. If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program. Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version. 15. Disclaimer of Warranty. THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. END OF TERMS AND CONDITIONS =========================== How to Apply These Terms to Your New Programs ============================================= If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES. Copyright (C) YEAR NAME OF AUTHOR This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Also add information on how to contact you by electronic and paper mail. If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode: PROGRAM Copyright (C) YEAR NAME OF AUTHOR This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’. This is free software, and you are welcome to redistribute it under certain conditions; type ‘show c’ for details. The hypothetical commands ‘show w’ and ‘show c’ should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an "about box". You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see . The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read .  File: gdb.info, Node: GNU Free Documentation License, Next: Concept Index, Prev: Copying, Up: Top Appendix N GNU Free Documentation License ***************************************** Version 1.3, 3 November 2008 Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 0. PREAMBLE The purpose of this License is to make a manual, textbook, or other functional and useful document “free” in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others. This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software. We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference. 1. APPLICABILITY AND DEFINITIONS This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law. A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language. A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them. The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none. The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words. A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not "Transparent" is called "Opaque". Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only. The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text. The "publisher" means any person or entity that distributes copies of the Document to the public. A section "Entitled XYZ" means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as "Acknowledgements", "Dedications", "Endorsements", or "History".) To "Preserve the Title" of such a section when you modify the Document means that it remains a section "Entitled XYZ" according to this definition. The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License. 2. VERBATIM COPYING You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3. You may also lend copies, under the same conditions stated above, and you may publicly display copies. 3. COPYING IN QUANTITY If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects. If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages. If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public. It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document. 4. MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version: A. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission. B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement. C. State on the Title page the name of the publisher of the Modified Version, as the publisher. D. Preserve all the copyright notices of the Document. E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices. F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below. G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice. H. Include an unaltered copy of this License. I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence. J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission. K. For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein. L. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles. M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version. N. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section. O. Preserve any Warranty Disclaimers. If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles. You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard. You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one. The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version. 5. COMBINING DOCUMENTS You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers. The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work. In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements." 6. COLLECTIONS OF DOCUMENTS You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects. You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document. 7. AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document. If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate. 8. TRANSLATION Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail. If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title. 9. TERMINATION You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License. However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it. 10. FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See . Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document. 11. RELICENSING "Massive Multiauthor Collaboration Site" (or "MMC Site") means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A "Massive Multiauthor Collaboration" (or "MMC") contained in the site means any set of copyrightable works thus published on the MMC site. "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization. "Incorporate" means to publish or republish a Document, in whole or in part, as part of another Document. An MMC is "eligible for relicensing" if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008. The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing. ADDENDUM: How to use this License for your documents ==================================================== To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: Copyright (C) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the "with...Texts." line with this: with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation. If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.  File: gdb.info, Node: Concept Index, Next: Command and Variable Index, Prev: GNU Free Documentation License, Up: Top Concept Index ************* [index] * Menu: * _NSPrintForDebugger, and printing Objective-C objects: The Print Command with Objective-C. (line 11) * --annotate: Mode Options. (line 110) * --args: Mode Options. (line 123) * --attach, gdbserver option: Server. (line 86) * --batch: Mode Options. (line 33) * --batch-silent: Mode Options. (line 51) * --baud: Mode Options. (line 129) * --cd: Mode Options. (line 90) * --command: File Options. (line 56) * --configuration: Mode Options. (line 173) * --core: File Options. (line 48) * --data-directory: Mode Options. (line 95) * --debug-file, gdbserver option: Server. (line 174) * --debug-format, gdbserver option: Server. (line 178) * --debug, gdbserver option: Server. (line 146) * --directory: File Options. (line 92) * --early-init-command: File Options. (line 82) * --early-init-eval-command: File Options. (line 87) * --eval-command: File Options. (line 62) * --exec: File Options. (line 40) * --fullname: Mode Options. (line 100) * --init-command: File Options. (line 72) * --init-eval-command: File Options. (line 77) * --interpreter: Mode Options. (line 148) * --multi, gdbserver option: Connecting. (line 45) * --nh: Mode Options. (line 15) * --nowindows: Mode Options. (line 80) * --nx: Mode Options. (line 11) * --once, gdbserver option: Server. (line 126) * --pid: File Options. (line 52) * --quiet: Mode Options. (line 23) * --readnever, command-line option: File Options. (line 102) * --readnow: File Options. (line 96) * --return-child-result: Mode Options. (line 63) * --se: File Options. (line 44) * --selftest: Server. (line 212) * --silent: Mode Options. (line 23) * --statistics: Mode Options. (line 165) * --symbols: File Options. (line 36) * --tty: Mode Options. (line 138) * --tui: Mode Options. (line 141) * --version: Mode Options. (line 169) * --windows: Mode Options. (line 86) * --with-gdb-datadir: Data Files. (line 19) * --with-relocated-sources: Source Path. (line 149) * --with-sysroot: Files. (line 478) * --wrapper, gdbserver option: Server. (line 191) * --write: Mode Options. (line 160) * -b: Mode Options. (line 129) * -c: File Options. (line 48) * -d: File Options. (line 92) * -D: Mode Options. (line 95) * -e: File Options. (line 40) * -eiex: File Options. (line 87) * -eix: File Options. (line 82) * -ex: File Options. (line 62) * -f: Mode Options. (line 100) * -iex: File Options. (line 77) * -info-gdb-mi-command: GDB/MI Support Commands. (line 11) * -ix: File Options. (line 72) * -l: Mode Options. (line 133) * -n: Mode Options. (line 11) * -nw: Mode Options. (line 80) * -p: File Options. (line 52) * -q: Mode Options. (line 23) * -r: File Options. (line 96) * -readnever, option for symbol-file command: Files. (line 110) * -s: File Options. (line 36) * -t: Mode Options. (line 138) * -w: Mode Options. (line 86) * -x: File Options. (line 56) * ! packet: Packets. (line 49) * ? packet: Packets. (line 58) * ., Modula-2 scope operator: M2 Scope. (line 6) * .build-id directory: Separate Debug Files. (line 6) * .debug subdirectories: Separate Debug Files. (line 6) * .debug_gdb_scripts section: dotdebug_gdb_scripts section. (line 6) * .debug_names section: Debug Names. (line 6) * .gdb_index section: Index Files. (line 6) * .gdb_index section format: Index Section Format. (line 6) * .gdbinit: Initialization Files. (line 107) * .gnu_debugdata section: MiniDebugInfo. (line 6) * .gnu_debuglink sections: Separate Debug Files. (line 86) * .note.gnu.build-id sections: Separate Debug Files. (line 102) * .o files, reading symbols from: Files. (line 158) * "No symbol "foo" in current context": Variables. (line 122) * {TYPE}: Expressions. (line 41) * /proc: Process Information. (line 6) * &, background execution of commands: Background Execution. (line 16) * # in Modula-2: GDB/M2. (line 18) * : Target Description Format. (line 72) * : Target Description Format. (line 95) * : Target Description Format. (line 119) * : Target Description Format. (line 163) * values: Registers. (line 106) * : Target Description Format. (line 82) * : Target Description Format. (line 222) * : Target Description Format. (line 163) * : Target Description Format. (line 153) * : Target Description Format. (line 146) * $: Value History. (line 13) * $_ and info breakpoints: Set Breaks. (line 244) * $_ and info line: Machine Code. (line 35) * $_, $__, and value history: Memory. (line 136) * $$: Value History. (line 13) * A packet: Packets. (line 66) * AArch64 Memory Tagging Extension.: AArch64. (line 266) * AArch64 Pointer Authentication.: AArch64. (line 256) * AArch64 SME: AArch64. (line 46) * AArch64 SME2: AArch64. (line 220) * AArch64 support: AArch64. (line 6) * AArch64 SVE.: AArch64. (line 19) * abbreviation: Command Syntax. (line 13) * acknowledgment, for GDB remote: Packet Acknowledgment. (line 6) * active targets: Active Targets. (line 6) * Ada: Ada. (line 6) * Ada exception catching: Set Catchpoints. (line 66) * Ada exception handlers catching: Set Catchpoints. (line 92) * Ada mode, general: Ada Mode Intro. (line 6) * Ada task switching: Ada Tasks. (line 129) * Ada tasking and core file debugging: Ada Tasks and Core Files. (line 6) * Ada, deviations from: Additions to Ada. (line 6) * Ada, omissions from: Omissions from Ada. (line 6) * Ada, problems: Ada Glitches. (line 6) * Ada, source character set: Ada Source Character Set. (line 6) * Ada, tasking: Ada Tasks. (line 6) * add new commands for external monitor: Connecting. (line 279) * address locations: Address Locations. (line 6) * address of a symbol: Symbols. (line 98) * address size for remote targets: Remote Configuration. (line 12) * addressable memory unit: Memory. (line 150) * aggregates (Ada): Omissions from Ada. (line 42) * AIX threads: Debugging Output. (line 33) * aliases for commands: Aliases. (line 6) * aliases for commands, default arguments: Command aliases default args. (line 6) * alignment of remote memory accesses: Packets. (line 247) * all-stop mode: All-Stop Mode. (line 6) * Alpha stack: MIPS. (line 6) * always-read-ctf: Symbols. (line 763) * ambiguous expressions: Ambiguous Expressions. (line 6) * AMD GPU debugging info: Debugging Output. (line 38) * AMD GPU precise memory event reporting: AMD GPU. (line 165) * AMD GPU precise memory event reporting <1>: AMD GPU. (line 186) * AMD GPU support: AMD GPU. (line 6) * annotations: Annotations Overview. (line 6) * annotations for errors, warnings and interrupts: Errors. (line 6) * annotations for invalidation messages: Invalidation. (line 6) * annotations for prompts: Prompting. (line 6) * annotations for running programs: Annotations for Running. (line 6) * annotations for source display: Source Annotations. (line 6) * append data to a file: Dump/Restore Files. (line 6) * Application Data Integrity: Sparc64. (line 5) * apply a command to all frames (ignoring errors and empty output): Frame Apply. (line 96) * apply a command to all frames of all threads (ignoring errors and empty output): Threads. (line 236) * apply command to all threads (ignoring errors and empty output): Threads. (line 229) * apply command to several frames: Frame Apply. (line 6) * apply command to several threads: Threads. (line 194) * ARC EM: ARC. (line 6) * ARC HS: ARC. (line 6) * ARC specific commands: ARC. (line 6) * ARC600: ARC. (line 6) * ARC700: ARC. (line 6) * architecture debugging info: Debugging Output. (line 26) * argument count in user-defined commands: Define. (line 25) * arguments (to your program): Arguments. (line 6) * arguments, to gdbserver: Server. (line 34) * arguments, to user-defined commands: Define. (line 6) * ARM 32-bit mode: ARM. (line 16) * ARM AArch64: Debugging Output. (line 19) * array aggregates (Ada): Omissions from Ada. (line 42) * arrays: Arrays. (line 6) * arrays in expressions: Expressions. (line 13) * arrays slices (Fortran): Special Fortran Commands. (line 13) * artificial array: Arrays. (line 6) * assembly instructions: Machine Code. (line 44) * assignment: Assignment. (line 6) * async output in GDB/MI: GDB/MI Output Syntax. (line 98) * async records in GDB/MI: GDB/MI Async Records. (line 6) * asynchronous execution: Background Execution. (line 6) * asynchronous execution <1>: Asynchronous and non-stop modes. (line 15) * asynchronous execution, and process record and replay: Process Record and Replay. (line 101) * AT&T disassembly flavor: Machine Code. (line 273) * attach: Attach. (line 6) * attach to a program, gdbserver: Server. (line 86) * auto-loading: Auto-loading. (line 6) * auto-loading extensions: Auto-loading extensions. (line 6) * auto-loading init file in the current directory: Init File in the Current Directory. (line 6) * auto-loading libthread_db.so.1: libthread_db.so.1 file. (line 6) * auto-loading safe-path: Auto-loading safe path. (line 6) * auto-loading verbose mode: Auto-loading verbose mode. (line 6) * auto-retry, for remote TCP target: Remote Configuration. (line 131) * automatic display: Auto Display. (line 6) * automatic hardware breakpoints: Set Breaks. (line 405) * automatic overlay debugging: Automatic Overlay Debugging. (line 6) * automatic symbol index cache: Index Files. (line 73) * automatic thread selection: All-Stop Mode. (line 28) * auxiliary vector: OS Information. (line 9) * AVR: AVR. (line 6) * b packet: Packets. (line 75) * B packet: Packets. (line 90) * background execution: Background Execution. (line 6) * background execution <1>: Asynchronous and non-stop modes. (line 15) * backtrace beyond main function: Backtrace. (line 155) * backtrace limit: Backtrace. (line 192) * base name differences: Files. (line 545) * baud rate for remote targets: Remote Configuration. (line 21) * bc packet: Packets. (line 95) * bcache statistics: Maintenance Commands. (line 439) * bits in remote address: Remote Configuration. (line 12) * blocks in guile: Blocks In Guile. (line 6) * blocks in python: Blocks In Python. (line 6) * bookmark: Checkpoint/Restart. (line 6) * boundary violations, Intel MPX: Signals. (line 199) * branch trace configuration format: Branch Trace Configuration Format. (line 6) * branch trace format: Branch Trace Format. (line 6) * branch trace store: Process Record and Replay. (line 70) * break in overloaded functions: Debugging C Plus Plus. (line 9) * break on a system call.: Set Catchpoints. (line 120) * break on fork/exec: Set Catchpoints. (line 116) * BREAK signal instead of Ctrl-C: Remote Configuration. (line 36) * breakpoint address adjusted: Breakpoint-related Warnings. (line 6) * breakpoint at static probe point: Linespec Locations. (line 65) * breakpoint commands: Break Commands. (line 6) * breakpoint commands for GDB/MI: GDB/MI Breakpoint Commands. (line 6) * breakpoint commands, in remote protocol: General Query Packets. (line 1050) * breakpoint conditions: Conditions. (line 6) * breakpoint debugging info: Debugging Output. (line 326) * breakpoint kinds, ARM: ARM Breakpoint Kinds. (line 6) * breakpoint kinds, MIPS: MIPS Breakpoint Kinds. (line 6) * breakpoint lists: Breakpoints. (line 45) * breakpoint numbers: Breakpoints. (line 38) * breakpoint on events: Breakpoints. (line 30) * breakpoint on memory address: Breakpoints. (line 17) * breakpoint on variable modification: Breakpoints. (line 17) * breakpoint ranges: Breakpoints. (line 45) * breakpoint subroutine, remote: Stub Contents. (line 31) * breakpointing Ada elaboration code: Stopping Before Main Program. (line 6) * breakpoints: Breakpoints. (line 6) * breakpoints and inferiors: Inferior-Specific Breakpoints. (line 9) * breakpoints and tasks, in Ada: Ada Tasks. (line 181) * breakpoints and threads: Thread-Specific Breakpoints. (line 10) * breakpoints at functions matching a regexp: Set Breaks. (line 201) * breakpoints in guile: Breakpoints In Guile. (line 6) * breakpoints in overlays: Overlay Commands. (line 91) * breakpoints in python: Breakpoints In Python. (line 6) * breakpoints, multiple locations: Set Breaks. (line 311) * bs packet: Packets. (line 101) * bug criteria: Bug Criteria. (line 6) * bug reports: Bug Reporting. (line 6) * bugs in GDB: GDB Bugs. (line 6) * build ID sections: Separate Debug Files. (line 102) * build ID, and separate debugging files: Separate Debug Files. (line 6) * building GDB, requirements for: Requirements. (line 6) * built-in simulator target: Target Commands. (line 73) * builtin Go functions: Go. (line 31) * builtin Go types: Go. (line 28) * C and C++: C. (line 6) * C and C++ checks: C Checks. (line 6) * C and C++ constants: C Constants. (line 6) * C and C++ defaults: C Defaults. (line 6) * C and C++ operators: C Operators. (line 6) * c packet: Packets. (line 108) * C packet: Packets. (line 117) * C++: C. (line 10) * C++ compilers: C Plus Plus Expressions. (line 8) * C++ demangling: Debugging C Plus Plus. (line 36) * C++ exception handling: Debugging C Plus Plus. (line 20) * C++ overload debugging info: Debugging Output. (line 221) * C++ scope resolution: Variables. (line 90) * C++ symbol decoding style: Print Settings. (line 587) * C++ symbol display: Debugging C Plus Plus. (line 40) * caching data of targets: Caching Target Data. (line 6) * caching of bfd objects: File Caching. (line 6) * caching of opened files: File Caching. (line 6) * call dummy stack unwinding: Calling. (line 36) * call dummy stack unwinding on timeout.: Calling. (line 65) * call dummy stack unwinding on unhandled exception.: Calling. (line 53) * call overloaded functions: C Plus Plus Expressions. (line 26) * call stack: Stack. (line 9) * call stack traces: Backtrace. (line 6) * call-clobbered registers: Registers. (line 106) * caller-saved registers: Registers. (line 106) * calling functions: Calling. (line 6) * calling functions in the program, disabling: Calling. (line 76) * calling make: Shell Commands. (line 25) * case sensitivity in symbol names: Symbols. (line 27) * case-insensitive symbol names: Symbols. (line 27) * casts, in expressions: Expressions. (line 26) * casts, to view memory: Expressions. (line 41) * catch Ada exceptions: Set Catchpoints. (line 66) * catch Ada exceptions when handled: Set Catchpoints. (line 92) * catch syscalls from inferior, remote request: General Query Packets. (line 439) * catchpoints: Breakpoints. (line 30) * catchpoints, setting: Set Catchpoints. (line 6) * change GDB's working directory: Working Directory. (line 32) * change inferior's working directory: Working Directory. (line 13) * character sets: Character Sets. (line 6) * charset: Character Sets. (line 6) * check if a given address is in a memory tagged region: General Query Packets. (line 332) * checkpoint: Checkpoint/Restart. (line 6) * checkpoints and process id: Checkpoint/Restart. (line 76) * checks, range: Type Checking. (line 44) * checks, type: Checks. (line 23) * checksum, for GDB remote: Overview. (line 21) * choosing target byte order: Byte Order. (line 6) * circular trace buffer: Starting and Stopping Trace Experiments. (line 80) * clearing breakpoints, watchpoints, catchpoints: Delete Breaks. (line 6) * CLI commands in python: CLI Commands In Python. (line 6) * close, file-i/o system call: close. (line 6) * closest symbol and offset for an address: Symbols. (line 108) * code address and its source line: Machine Code. (line 29) * code compression, MIPS: MIPS. (line 49) * code location: Location Specifications. (line 6) * COFF/PE exported symbols: Debugging Output. (line 82) * collected data discarded: Starting and Stopping Trace Experiments. (line 6) * colon-colon, context for variables/functions: Variables. (line 44) * colon, doubled as scope operator: M2 Scope. (line 6) * colors: Output Styling. (line 6) * command editing: Readline Bare Essentials. (line 6) * command files: Command Files. (line 6) * command history: Command History. (line 6) * command hooks: Hooks. (line 6) * command interpreters: Interpreters. (line 6) * command line editing: Editing. (line 6) * command options: Command Options. (line 6) * command options, boolean: Command Options. (line 21) * command options, raw input: Command Options. (line 13) * command scripts, debugging: Messages/Warnings. (line 65) * command tracing: Messages/Warnings. (line 60) * commands for C++: Debugging C Plus Plus. (line 6) * commands in guile: Commands In Guile. (line 6) * commands in python, CLI: CLI Commands In Python. (line 6) * commands in python, GDB/MI: GDB/MI Commands In Python. (line 6) * commands to access guile: Guile Commands. (line 6) * commands to access python: Python Commands. (line 6) * comment: Command Syntax. (line 37) * COMMON blocks, Fortran: Special Fortran Commands. (line 9) * common targets: Target Commands. (line 46) * compatibility, GDB/MI and CLI: GDB/MI Compatibility with CLI. (line 6) * compilation directory: Source Path. (line 40) * compile C++ type conversion: Compiling and Injecting Code. (line 90) * compile command debugging info: Compiling and Injecting Code. (line 82) * compile command driver filename override: Compiling and Injecting Code. (line 300) * compile command options override: Compiling and Injecting Code. (line 125) * compiling code: Compiling and Injecting Code. (line 6) * completion: Completion. (line 6) * completion of Guile commands: Commands In Guile. (line 100) * completion of Python commands: CLI Commands In Python. (line 72) * completion of quoted strings: Completion. (line 94) * completion of structure field names: Completion. (line 146) * completion of union field names: Completion. (line 146) * compressed debug sections: Requirements. (line 113) * conditional breakpoints: Conditions. (line 6) * conditional tracepoints: Tracepoint Conditions. (line 6) * configure debuginfod URLs: Debuginfod Settings. (line 31) * configuring GDB: Running Configure. (line 6) * confirmation: Messages/Warnings. (line 49) * connection timeout, for remote TCP target: Remote Configuration. (line 147) * connections in python: Connections In Python. (line 6) * console i/o as part of file-i/o: Console I/O. (line 6) * console interpreter: Interpreters. (line 21) * console output in GDB/MI: GDB/MI Output Syntax. (line 106) * constants, in file-i/o protocol: Constants. (line 6) * continuing: Continuing and Stepping. (line 6) * continuing threads: Thread Stops. (line 6) * control C, and remote debugging: Bootstrapping. (line 25) * controlling terminal: Input/Output. (line 23) * convenience functions: Convenience Funs. (line 6) * convenience functions in python: Functions In Python. (line 6) * convenience variables: Convenience Vars. (line 6) * convenience variables for tracepoints: Tracepoint Variables. (line 6) * convenience variables, and trace state variables: Trace State Variables. (line 17) * convenience variables, initializing: Convenience Vars. (line 42) * core dump file: Files. (line 6) * core dump file target: Target Commands. (line 54) * crash of debugger: Bug Criteria. (line 9) * CRC algorithm definition: Separate Debug Files. (line 146) * CRC of memory block, remote request: General Query Packets. (line 65) * CRIS: CRIS. (line 6) * CRIS mode: CRIS. (line 26) * CRIS version: CRIS. (line 10) * CTF info, when to read: Symbols. (line 763) * Ctrl-BREAK, MS-Windows: Cygwin Native. (line 9) * ctrl-c message, in file-i/o protocol: The Ctrl-C Message. (line 6) * current Ada task ID: Ada Tasks. (line 119) * current directory: Source Path. (line 40) * current Go package: Go. (line 11) * current thread: Threads. (line 29) * current thread, remote request: General Query Packets. (line 55) * custom JIT debug info: Custom Debug Info. (line 6) * Cygwin DLL, debugging: Cygwin Native. (line 60) * Cygwin-specific commands: Cygwin Native. (line 6) * D: D. (line 6) * d packet: Packets. (line 126) * D packet: Packets. (line 133) * DAP: Interpreters. (line 26) * Darwin: Darwin. (line 6) * data breakpoints: Breakpoints. (line 17) * data manipulation, in GDB/MI: GDB/MI Data Manipulation. (line 6) * dcache line-size: Caching Target Data. (line 60) * dcache size: Caching Target Data. (line 57) * dcache, flushing: Caching Target Data. (line 71) * dead names, GNU Hurd: Hurd Native. (line 84) * debug expression parser: Debugging Output. (line 228) * debug formats and C++: C Plus Plus Expressions. (line 8) * debug link sections: Separate Debug Files. (line 86) * debug remote protocol: Debugging Output. (line 236) * Debugger Adapter Protocol: Interpreters. (line 26) * debugger crash: Bug Criteria. (line 9) * debugging agent: In-Process Agent. (line 6) * debugging C++ programs: C Plus Plus Expressions. (line 8) * debugging information directory, global: Separate Debug Files. (line 6) * debugging information in separate files: Separate Debug Files. (line 6) * debugging libthread_db: Threads. (line 338) * debugging multiple processes: Forks. (line 55) * debugging optimized code: Optimized Code. (line 6) * debugging stub, example: Remote Stub. (line 6) * debugging target: Targets. (line 6) * debugging the Cygwin DLL: Cygwin Native. (line 60) * debugging threads: Threads. (line 343) * debuginfod: Debuginfod. (line 6) * debuginfod verbosity: Debuginfod Settings. (line 41) * debuginfod, maintenance commands: Maintenance Commands. (line 241) * decimal floating point format: Decimal Floating Point. (line 6) * default behavior of commands, changing: Command Settings. (line 6) * default collection action: Tracepoint Actions. (line 142) * default data directory: Data Files. (line 19) * default settings, changing: Command Settings. (line 6) * default source path substitution: Source Path. (line 149) * default system root: Files. (line 478) * define trace state variable, remote request: Tracepoint Packets. (line 117) * defining macros interactively: Macros. (line 60) * definition of a macro, showing: Macros. (line 47) * delete breakpoints: Delete Breaks. (line 56) * deleting breakpoints, watchpoints, catchpoints: Delete Breaks. (line 6) * deliver a signal to a program: Signaling. (line 6) * demangle: Symbols. (line 127) * demangler crashes: Maintenance Commands. (line 190) * demangler crashes <1>: Maintenance Commands. (line 217) * demangler crashes <2>: Maintenance Commands. (line 249) * demangling C++ names: Print Settings. (line 568) * deprecated commands: Maintenance Commands. (line 204) * derived type of an object, printing: Print Settings. (line 599) * descriptor tables display: DJGPP Native. (line 24) * detach from task, GNU Hurd: Hurd Native. (line 59) * detach from thread, GNU Hurd: Hurd Native. (line 109) * direct memory access (DMA) on MS-DOS: DJGPP Native. (line 74) * directories for source files: Source Path. (line 6) * directory, compilation: Source Path. (line 40) * directory, current: Source Path. (line 40) * disable address space randomization, remote request: General Query Packets. (line 82) * disabling calling functions in the program: Calling. (line 76) * disassembler in Python, global vs. specific: Disassembly In Python. (line 466) * disassembler options: Machine Code. (line 258) * disconnected tracing: Starting and Stopping Trace Experiments. (line 45) * displaced stepping debugging info: Debugging Output. (line 111) * displaced stepping support: Maintenance Commands. (line 156) * displaced stepping, and process record and replay: Process Record and Replay. (line 96) * display command history: Command History. (line 110) * display derived types: Print Settings. (line 599) * display disabled out of scope: Auto Display. (line 86) * display GDB copyright: Help. (line 174) * display of expressions: Auto Display. (line 6) * display remote monitor communications: Target Commands. (line 107) * display remote packets: Debugging Output. (line 236) * DJGPP debugging: DJGPP Native. (line 6) * DLLs with no debugging symbols: Non-debug DLL Symbols. (line 6) * do not print frame arguments: Print Settings. (line 200) * documentation: Formatting Documentation. (line 22) * don't repeat command: Define. (line 118) * don't repeat Guile command: Commands In Guile. (line 67) * don't repeat Python command: CLI Commands In Python. (line 42) * DOS file-name semantics of file names.: Files. (line 501) * DOS serial data link, remote debugging: DJGPP Native. (line 118) * DOS serial port status: DJGPP Native. (line 139) * DPMI: DJGPP Native. (line 6) * dprintf: Dynamic Printf. (line 6) * dump all data collected at tracepoint: tdump. (line 6) * dump core from inferior: Core File Generation. (line 6) * dump data to a file: Dump/Restore Files. (line 6) * dump/restore files: Dump/Restore Files. (line 6) * DVC register: PowerPC Embedded. (line 6) * DWARF compilation units cache: Maintenance Commands. (line 517) * DWARF DIEs: Debugging Output. (line 89) * DWARF frame unwinders: Maintenance Commands. (line 548) * DWARF Line Tables: Debugging Output. (line 95) * DWARF Reading: Debugging Output. (line 103) * DWARF-2 CFI and CRIS: CRIS. (line 18) * dynamic linking: Files. (line 132) * dynamic printf: Dynamic Printf. (line 6) * dynamic varobj: GDB/MI Variable Objects. (line 163) * early initialization: Initialization Files. (line 14) * early initialization file: Startup. (line 10) * editing: Editing. (line 15) * editing command lines: Readline Bare Essentials. (line 6) * editing source files: Edit. (line 6) * eight-bit characters in strings: Print Settings. (line 513) * elaboration phase: Starting. (line 92) * ELinOS system-wide configuration script: System-wide Configuration Scripts. (line 15) * Emacs: Emacs. (line 6) * empty response, for unsupported packets: Standard Replies. (line 11) * enable debuginfod: Debuginfod Settings. (line 10) * enable/disable a breakpoint: Disabling. (line 6) * enabling and disabling probes: Static Probe Points. (line 52) * entering numbers: Numbers. (line 6) * environment (of your program): Environment. (line 6) * errno values, in file-i/o protocol: Errno Values. (line 6) * error on valid input: Bug Criteria. (line 12) * event debugging info: Debugging Output. (line 118) * event designators: Event Designators. (line 6) * event handling: Set Catchpoints. (line 6) * event-loop debugging: Debugging Output. (line 124) * examine process image: Process Information. (line 6) * examining data: Data. (line 6) * examining memory: Memory. (line 9) * exception handlers: Set Catchpoints. (line 6) * exceptions, guile: Guile Exception Handling. (line 6) * exceptions, python: Exception Handling. (line 6) * exec events, remote reply: Stop Reply Packets. (line 141) * executable file: Files. (line 16) * executable file target: Target Commands. (line 50) * executable file, for remote target: Remote Configuration. (line 102) * execute commands from a file: Command Files. (line 17) * execute forward or backward in time: Reverse Execution. (line 92) * execute remote command, remote request: General Query Packets. (line 612) * execution, foreground, background and asynchronous: Background Execution. (line 6) * execution, foreground, background and asynchronous <1>: Asynchronous and non-stop modes. (line 15) * exit status of shell commands: Convenience Vars. (line 192) * exiting GDB: Quitting GDB. (line 6) * expand macro once: Macros. (line 38) * expanding preprocessor macros: Macros. (line 29) * explicit locations: Explicit Locations. (line 6) * explore type: Data. (line 254) * explore value: Data. (line 247) * exploring hierarchical data structures: Data. (line 145) * expression debugging info: Debugging Output. (line 133) * expression parser, debugging info: Debugging Output. (line 228) * expressions: Expressions. (line 6) * expressions in Ada: Ada. (line 11) * expressions in C or C++: C. (line 6) * expressions in C++: C Plus Plus Expressions. (line 6) * expressions in Modula-2: Modula-2. (line 12) * extend GDB for remote targets: Connecting. (line 279) * extending GDB: Extending GDB. (line 6) * extra signal information: Signals. (line 158) * F packet: Packets. (line 147) * F reply packet: The F Reply Packet. (line 6) * F request packet: The F Request Packet. (line 6) * fast tracepoints: Set Tracepoints. (line 24) * fast tracepoints, setting: Create and Delete Tracepoints. (line 50) * fatal signal: Bug Criteria. (line 9) * fatal signals: Signals. (line 15) * features of the remote protocol: General Query Packets. (line 655) * fetch memory tags: General Query Packets. (line 312) * file name canonicalization: Files. (line 545) * file names, quoting and escaping: Filename Arguments. (line 6) * file transfer: File Transfer. (line 6) * file transfer, remote protocol: Host I/O Packets. (line 6) * file-i/o examples: File-I/O Examples. (line 6) * file-i/o overview: File-I/O Overview. (line 6) * File-I/O remote protocol extension: File-I/O Remote Protocol Extension. (line 6) * file-i/o reply packet: The F Reply Packet. (line 6) * file-i/o request packet: The F Request Packet. (line 6) * filename-display: Backtrace. (line 202) * find trace snapshot: tfind. (line 6) * flinching: Messages/Warnings. (line 49) * float promotion: ABI. (line 34) * floating point: Floating Point Hardware. (line 6) * floating point registers: Registers. (line 15) * floating point, MIPS remote: MIPS Embedded. (line 13) * focus of debugging: Threads. (line 29) * foo: Symbol Errors. (line 54) * foreground execution: Background Execution. (line 6) * foreground execution <1>: Asynchronous and non-stop modes. (line 15) * fork events, remote reply: Stop Reply Packets. (line 104) * fork, debugging programs which call: Forks. (line 6) * format options: Print Settings. (line 6) * formatted output: Output Formats. (line 6) * Fortran: Summary. (line 40) * fortran array slicing debugging info: Debugging Output. (line 151) * Fortran Defaults: Fortran. (line 14) * Fortran Intrinsics: Fortran Intrinsics. (line 6) * Fortran modules, information about: Symbols. (line 589) * Fortran operators and expressions: Fortran Operators. (line 6) * Fortran Types: Fortran Types. (line 6) * Fortran-specific support in GDB: Fortran. (line 6) * frame debugging info: Debugging Output. (line 159) * frame decorator api: Frame Decorator API. (line 6) * frame filters api: Frame Filter API. (line 6) * frame information, printing: Print Settings. (line 360) * frame level: Frames. (line 28) * frame number: Frames. (line 28) * frame pointer: Frames. (line 21) * frame pointer register: Registers. (line 31) * frame, definition: Frames. (line 6) * frameless execution: Frames. (line 34) * frames in guile: Frames In Guile. (line 6) * frames in python: Frames In Python. (line 6) * free memory information (MS-DOS): DJGPP Native. (line 19) * FreeBSD: FreeBSD. (line 6) * FreeBSD LWP debug messages: Debugging Output. (line 140) * FreeBSD native target debug messages: Debugging Output. (line 146) * fstat, file-i/o system call: stat/fstat. (line 6) * Fujitsu: Remote Stub. (line 68) * full symbol tables, listing GDB's internal: Symbols. (line 684) * function call arguments, optimized out: Backtrace. (line 133) * function entry/exit, wrong values of variables: Variables. (line 106) * functions and variables by Fortran module: Symbols. (line 589) * functions without line info, and stepping: Continuing and Stepping. (line 92) * g packet: Packets. (line 152) * G packet: Packets. (line 187) * g++, GNU C++ compiler: C. (line 10) * garbled pointers: DJGPP Native. (line 42) * GCC and C++: C Plus Plus Expressions. (line 8) * GDB bugs, reporting: Bug Reporting. (line 6) * GDB internal error: Maintenance Commands. (line 249) * gdb module: Basic Python. (line 31) * gdb objects: GDB Scheme Data Types. (line 6) * GDB reference card: Formatting Documentation. (line 6) * GDB startup: Startup. (line 6) * GDB version number: Help. (line 164) * gdb.ini: Initialization Files. (line 107) * gdb.printing: gdb.printing. (line 6) * gdb.prompt: gdb.prompt. (line 6) * gdb.types: gdb.types. (line 6) * gdb.Value: Values From Inferior. (line 6) * GDB/MI development: GDB/MI Development and Front Ends. (line 6) * GDB/MI General Design: GDB/MI General Design. (line 6) * GDB/MI, async records: GDB/MI Async Records. (line 6) * GDB/MI, breakpoint commands: GDB/MI Breakpoint Commands. (line 6) * GDB/MI, compatibility with CLI: GDB/MI Compatibility with CLI. (line 6) * GDB/MI, data manipulation: GDB/MI Data Manipulation. (line 6) * GDB/MI, input syntax: GDB/MI Input Syntax. (line 6) * GDB/MI, its purpose: GDB/MI. (line 36) * GDB/MI, output syntax: GDB/MI Output Syntax. (line 6) * GDB/MI, result records: GDB/MI Result Records. (line 6) * GDB/MI, simple examples: GDB/MI Simple Examples. (line 6) * GDB/MI, stream records: GDB/MI Stream Records. (line 6) * gdbarch debugging info: Debugging Output. (line 26) * GDBHISTFILE, environment variable: Command History. (line 26) * GDBHISTSIZE, environment variable: Command History. (line 56) * gdbinit: Initialization Files. (line 107) * gdbserver, command-line arguments: Server. (line 34) * gdbserver, connecting: Connecting. (line 6) * gdbserver, search path for libthread_db: Server. (line 295) * gdbserver, send all debug output to a single file: Server. (line 174) * gdbserver, target extended-remote mode: Connecting. (line 6) * gdbserver, target remote mode: Connecting. (line 6) * gdbserver, types of connections: Connecting. (line 6) * GDT: DJGPP Native. (line 24) * general initialization: Initialization Files. (line 30) * get thread information block address: General Query Packets. (line 281) * get thread-local storage address, remote request: General Query Packets. (line 257) * gettimeofday, file-i/o system call: gettimeofday. (line 6) * getting structure elements using gdb.Field objects as subscripts: Values From Inferior. (line 40) * global debugging information directories: Separate Debug Files. (line 6) * global thread identifier (GDB): Threads. (line 88) * global thread number: Threads. (line 88) * GNAT descriptive types: Ada Glitches. (line 57) * GNAT encoding: Ada Glitches. (line 57) * GNU C++: C. (line 10) * GNU Emacs: Emacs. (line 6) * GNU Hurd debugging: Hurd Native. (line 6) * GNU/Hurd debug messages: Debugging Output. (line 165) * GNU/Linux namespaces debug messages: Debugging Output. (line 195) * GNU/Linux native target debug messages: Debugging Output. (line 189) * Go (programming language): Go. (line 6) * guile api: Guile API. (line 6) * guile architectures: Architectures In Guile. (line 6) * guile auto-loading: Guile Auto-loading. (line 6) * guile commands: Guile Commands. (line 6) * guile commands <1>: Commands In Guile. (line 6) * guile configuration: Guile Configuration. (line 6) * guile exceptions: Guile Exception Handling. (line 6) * guile gdb module: Basic Guile. (line 37) * guile iterators: Iterators In Guile. (line 6) * guile modules: Guile Modules. (line 6) * guile pagination: Basic Guile. (line 6) * guile parameters: Parameters In Guile. (line 6) * guile pretty printing api: Guile Pretty Printing API. (line 6) * guile scripting: Guile. (line 6) * guile scripts directory: Guile Introduction. (line 15) * guile stdout: Basic Guile. (line 6) * guile, working with types: Types In Guile. (line 6) * guile, working with values from inferior: Values From Inferior In Guile. (line 6) * H packet: Packets. (line 195) * handling signals: Signals. (line 27) * hardware breakpoints: Set Breaks. (line 172) * hardware debug registers: Maintenance Commands. (line 598) * hardware watchpoints: Set Watchpoints. (line 31) * hash mark while downloading: Target Commands. (line 98) * heuristic-fence-post (Alpha, MIPS): MIPS. (line 14) * history events: Event Designators. (line 8) * history expansion: History Interaction. (line 6) * history expansion, turn on/off: Command History. (line 85) * history file: Command History. (line 26) * history number: Value History. (line 13) * history of values printed by GDB: Value History. (line 6) * history size: Command History. (line 56) * history substitution: Command History. (line 26) * hooks, for commands: Hooks. (line 6) * hooks, post-command: Hooks. (line 11) * hooks, pre-command: Hooks. (line 6) * host character set: Character Sets. (line 6) * Host I/O, remote protocol: Host I/O Packets. (line 6) * how many arguments (user-defined commands): Define. (line 25) * HPPA support: HPPA. (line 6) * i packet: Packets. (line 207) * I packet: Packets. (line 212) * i/o: Input/Output. (line 6) * I/O registers (Atmel AVR): AVR. (line 10) * i386: Remote Stub. (line 56) * i386-stub.c: Remote Stub. (line 56) * ID list: Inferiors Connections and Programs. (line 25) * IDT: DJGPP Native. (line 24) * ignore count (of breakpoint): Conditions. (line 85) * in-process agent protocol: In-Process Agent Protocol. (line 6) * incomplete type: Symbols. (line 367) * indentation in structure display: Print Settings. (line 475) * index files: Index Files. (line 6) * index files <1>: Debug Names. (line 6) * index section format: Index Section Format. (line 6) * inferior: Inferiors Connections and Programs. (line 15) * inferior debugging info: Debugging Output. (line 170) * inferior events in Python: Events In Python. (line 6) * inferior function call debugging info: Debugging Output. (line 178) * inferior functions, calling: Calling. (line 6) * inferior tty: Input/Output. (line 44) * inferior-specific breakpoints: Inferior-Specific Breakpoints. (line 9) * inferiors in Python: Inferiors In Python. (line 6) * infinite recursion in user-defined commands: Define. (line 135) * info for known .debug_gdb_scripts-loaded scripts: Maintenance Commands. (line 432) * info for known object files: Maintenance Commands. (line 417) * info line, repeated calls: Machine Code. (line 41) * info proc cmdline: Process Information. (line 41) * info proc cwd: Process Information. (line 45) * info proc exe: Process Information. (line 49) * info proc files: Process Information. (line 53) * information about static tracepoint markers: Listing Static Tracepoint Markers. (line 6) * information about tracepoints: Listing Tracepoints. (line 6) * inheritance: Debugging C Plus Plus. (line 26) * init file: Startup. (line 23) * init file name: Initialization Files. (line 6) * initial frame: Frames. (line 12) * initialization file: Initialization Files. (line 34) * initialization file, readline: Readline Init File. (line 6) * injecting code: Compiling and Injecting Code. (line 6) * inline functions, debugging: Inline Functions. (line 6) * innermost frame: Frames. (line 12) * input syntax for GDB/MI: GDB/MI Input Syntax. (line 6) * installation: Installing GDB. (line 6) * instructions, assembly: Machine Code. (line 44) * integral datatypes, in file-i/o protocol: Integral Datatypes. (line 6) * Intel: Remote Stub. (line 56) * Intel disassembly flavor: Machine Code. (line 273) * Intel Memory Protection Extensions (MPX).: x86. (line 21) * Intel MPX boundary violations: Signals. (line 199) * Intel Processor Trace: Process Record and Replay. (line 75) * interaction, readline: Readline Interaction. (line 6) * internal commands: Maintenance Commands. (line 6) * internal errors, control of GDB behavior: Maintenance Commands. (line 249) * internal GDB breakpoints: Set Breaks. (line 483) * interrupt: Quitting GDB. (line 15) * interrupt debuggee on MS-Windows: Cygwin Native. (line 9) * interrupt remote programs: Remote Configuration. (line 36) * interrupt remote programs <1>: Remote Configuration. (line 108) * interrupting remote programs: Connecting. (line 246) * interrupting remote targets: Bootstrapping. (line 25) * interrupts (remote protocol): Interrupts. (line 6) * invalid input: Bug Criteria. (line 16) * invoke another interpreter: Interpreters. (line 44) * ipa protocol commands: IPA Protocol Commands. (line 6) * ipa protocol objects: IPA Protocol Objects. (line 6) * isatty, file-i/o system call: isatty. (line 6) * JIT compilation interface: JIT Interface. (line 6) * JIT debug info reader: Custom Debug Info. (line 6) * just-in-time compilation: JIT Interface. (line 6) * just-in-time compilation, debugging messages: Debugging Output. (line 184) * k packet: Packets. (line 216) * kernel crash dump: BSD libkvm Interface. (line 6) * kernel memory image: BSD libkvm Interface. (line 6) * kill ring: Readline Killing Commands. (line 18) * killing text: Readline Killing Commands. (line 6) * languages: Languages. (line 6) * last tracepoint number: Create and Delete Tracepoints. (line 124) * latest breakpoint: Set Breaks. (line 6) * lazy strings in guile: Lazy Strings In Guile. (line 6) * lazy strings in python: Lazy Strings In Python. (line 6) * LDT: DJGPP Native. (line 24) * leaving GDB: Quitting GDB. (line 6) * libkvm: BSD libkvm Interface. (line 6) * library list format, remote protocol: Library List Format. (line 6) * library list format, remote protocol <1>: Library List Format for SVR4 Targets. (line 6) * limit hardware breakpoints and watchpoints: Remote Configuration. (line 79) * limit hardware watchpoints length: Remote Configuration. (line 91) * limit on number of printed array elements: Print Settings. (line 179) * limit on number of printed string characters: Print Settings. (line 159) * limits, in file-i/o protocol: Limits. (line 6) * line tables in python: Line Tables In Python. (line 6) * line tables, listing GDB's internal: Symbols. (line 731) * linespec locations: Linespec Locations. (line 6) * Linux native targets: Debugging Output. (line 189) * list active threads, remote request: General Query Packets. (line 224) * list of supported file-i/o calls: List of Supported Calls. (line 6) * list output in GDB/MI: GDB/MI Output Syntax. (line 117) * list, how many lines to display: List. (line 40) * listing GDB's internal line tables: Symbols. (line 731) * listing GDB's internal symbol tables: Symbols. (line 684) * listing machine instructions: Machine Code. (line 44) * listing mapped overlays: Overlay Commands. (line 60) * lists of breakpoints: Breakpoints. (line 45) * load address, overlay's: How Overlays Work. (line 6) * load shared library: Files. (line 352) * load symbols from memory: Files. (line 208) * local socket, target remote: Connecting. (line 147) * local variables: Symbols. (line 436) * locate address: Output Formats. (line 36) * location resolution: Location Specifications. (line 14) * location spec: Location Specifications. (line 6) * lock scheduler: All-Stop Mode. (line 37) * locspec: Location Specifications. (line 6) * log output in GDB/MI: GDB/MI Output Syntax. (line 113) * logging file name: Logging Output. (line 10) * logging GDB output: Logging Output. (line 6) * look up of disassembler in Python: Disassembly In Python. (line 466) * lseek flags, in file-i/o protocol: Lseek Flags. (line 6) * lseek, file-i/o system call: lseek. (line 6) * m packet: Packets. (line 239) * M packet: Packets. (line 260) * m680x0: Remote Stub. (line 59) * m68k-stub.c: Remote Stub. (line 59) * Mach-O symbols processing: Debugging Output. (line 201) * machine instructions: Machine Code. (line 44) * macro definition, showing: Macros. (line 47) * macro expansion, showing the results of preprocessor: Macros. (line 29) * macros, example of debugging with: Macros. (line 84) * macros, from debug info: Macros. (line 47) * macros, user-defined: Macros. (line 60) * mailing lists: GDB/MI Development and Front Ends. (line 93) * maintenance commands: Maintenance Commands. (line 6) * Man pages: Man Pages. (line 6) * managing frame filters: Frame Filter Management. (line 6) * manual overlay debugging: Overlay Commands. (line 23) * map an overlay: Overlay Commands. (line 30) * mapinfo list, QNX Neutrino: Process Information. (line 131) * mapped address: How Overlays Work. (line 6) * mapped overlays: How Overlays Work. (line 6) * markers, static tracepoints: Set Tracepoints. (line 28) * maximum value for offset of closest symbol: Print Settings. (line 70) * member functions: C Plus Plus Expressions. (line 16) * memory address space mappings: Process Information. (line 80) * memory address space mappings <1>: Maintenance Commands. (line 329) * memory map format: Memory Map Format. (line 6) * memory region attributes: Memory Region Attributes. (line 6) * memory tag types, ARM: ARM Memory Tag Types. (line 6) * memory tracing: Breakpoints. (line 17) * memory transfer, in file-i/o protocol: Memory Transfer. (line 6) * memory used by commands: Maintenance Commands. (line 750) * memory used for symbol tables: Files. (line 340) * memory, alignment and size of remote accesses: Packets. (line 247) * memory, viewing as typed object: Expressions. (line 41) * MI commands in python: GDB/MI Commands In Python. (line 6) * mi interpreter: Interpreters. (line 34) * MI notifications in python: GDB/MI Notifications In Python. (line 6) * mi2 interpreter: Interpreters. (line 42) * mi3 interpreter: Interpreters. (line 39) * minimal language: Unsupported Languages. (line 6) * minimal symbol dump: Symbols. (line 658) * Minimal symbols and DLLs: Non-debug DLL Symbols. (line 6) * MIPS addresses, masking: MIPS. (line 80) * MIPS remote floating point: MIPS Embedded. (line 13) * MIPS stack: MIPS. (line 6) * miscellaneous settings: Other Misc Settings. (line 6) * MMX registers (x86): Registers. (line 76) * mode_t values, in file-i/o protocol: mode_t Values. (line 6) * Modula-2: Summary. (line 29) * Modula-2 built-ins: Built-In Func/Proc. (line 6) * Modula-2 checks: M2 Checks. (line 6) * Modula-2 constants: Built-In Func/Proc. (line 114) * Modula-2 defaults: M2 Defaults. (line 6) * Modula-2 operators: M2 Operators. (line 6) * Modula-2 types: M2 Types. (line 6) * Modula-2, deviations from: Deviations. (line 6) * Modula-2, GDB support: Modula-2. (line 6) * module functions and variables: Symbols. (line 589) * modules: Symbols. (line 581) * monitor commands, for gdbserver: Server. (line 243) * Motorola 680x0: Remote Stub. (line 59) * MS Windows debugging: Cygwin Native. (line 6) * MS-DOS system info: DJGPP Native. (line 19) * MS-DOS-specific commands: DJGPP Native. (line 6) * multiple locations, breakpoints: Set Breaks. (line 311) * multiple processes: Forks. (line 6) * multiple targets: Active Targets. (line 6) * multiple threads: Threads. (line 6) * multiple threads, backtrace: Backtrace. (line 97) * multiple-symbols menu: Ambiguous Expressions. (line 51) * multiprocess extensions, in remote protocol: General Query Packets. (line 980) * name a thread: Threads. (line 254) * names of symbols: Symbols. (line 14) * namespace in C++: C Plus Plus Expressions. (line 20) * native Cygwin debugging: Cygwin Native. (line 6) * native DJGPP debugging: DJGPP Native. (line 6) * native script auto-loading: Auto-loading sequences. (line 6) * native target: Target Commands. (line 85) * negative breakpoint numbers: Set Breaks. (line 483) * never read symbols: Files. (line 110) * New SYSTAG message: Threads. (line 35) * new user interface: Interpreters. (line 73) * Newlib OS ABI and its influence on the longjmp handling: ABI. (line 11) * Nios II architecture: Nios II. (line 6) * no debug info functions: Calling. (line 181) * no debug info variables: Variables. (line 142) * non-member C++ functions, set breakpoint in: Set Breaks. (line 224) * non-stop mode: Non-Stop Mode. (line 6) * non-stop mode, and process record and replay: Process Record and Replay. (line 101) * non-stop mode, and set displaced-stepping: Maintenance Commands. (line 173) * non-stop mode, remote request: General Query Packets. (line 425) * noninvasive task options: Hurd Native. (line 72) * notation, readline: Readline Bare Essentials. (line 6) * notational conventions, for GDB/MI: GDB/MI. (line 52) * notification packets: Notification Packets. (line 6) * notifications in python, GDB/MI: GDB/MI Notifications In Python. (line 6) * notify output in GDB/MI: GDB/MI Output Syntax. (line 102) * NULL elements in arrays: Print Settings. (line 466) * number of array elements to print: Print Settings. (line 179) * number of string characters to print: Print Settings. (line 159) * number representation: Numbers. (line 6) * numbers for breakpoints: Breakpoints. (line 38) * object files, relocatable, reading symbols from: Files. (line 158) * Objective-C: Objective-C. (line 6) * Objective-C, classes and selectors: Symbols. (line 609) * Objective-C, print objects: The Print Command with Objective-C. (line 6) * OBJFILE-gdb.gdb: objfile-gdbdotext file. (line 6) * OBJFILE-gdb.py: objfile-gdbdotext file. (line 6) * OBJFILE-gdb.scm: objfile-gdbdotext file. (line 6) * objfiles in guile: Objfiles In Guile. (line 6) * objfiles in python: Objfiles In Python. (line 6) * observer debugging info: Debugging Output. (line 215) * octal escapes in strings: Print Settings. (line 513) * online documentation: Help. (line 6) * opaque data types: Symbols. (line 621) * open flags, in file-i/o protocol: Open Flags. (line 6) * open, file-i/o system call: open. (line 6) * OpenCL C: OpenCL C. (line 6) * OpenCL C Datatypes: OpenCL C Datatypes. (line 6) * OpenCL C Expressions: OpenCL C Expressions. (line 6) * OpenCL C Operators: OpenCL C Operators. (line 6) * OpenRISC 1000: OpenRISC 1000. (line 6) * operate-and-get-next: Editing. (line 32) * operating system information: Operating System Information. (line 6) * operating system information, process list: Process list. (line 6) * optimized code, debugging: Optimized Code. (line 6) * optimized code, wrong values of variables: Variables. (line 106) * optimized out value in guile: Values From Inferior In Guile. (line 102) * optimized out value in Python: Values From Inferior. (line 75) * optimized out, in backtrace: Backtrace. (line 133) * optional debugging messages: Debugging Output. (line 6) * optional warnings: Messages/Warnings. (line 6) * OS ABI: ABI. (line 11) * OS information: OS Information. (line 6) * out-of-line single-stepping: Maintenance Commands. (line 156) * outermost frame: Frames. (line 12) * output formats: Output Formats. (line 6) * output syntax of GDB/MI: GDB/MI Output Syntax. (line 6) * overlay area: How Overlays Work. (line 6) * overlay example program: Overlay Sample Program. (line 6) * overlays: Overlays. (line 6) * overlays, setting breakpoints in: Overlay Commands. (line 91) * overloaded functions, calling: C Plus Plus Expressions. (line 26) * overloaded functions, overload resolution: Debugging C Plus Plus. (line 59) * overloading in C++: Debugging C Plus Plus. (line 15) * overloading, Ada: Overloading support for Ada. (line 6) * p packet: Packets. (line 270) * P packet: Packets. (line 279) * packet acknowledgment, for GDB remote: Packet Acknowledgment. (line 6) * packet size, remote protocol: General Query Packets. (line 886) * packet size, remote, configuring: Remote Configuration. (line 347) * packets, notification: Notification Packets. (line 6) * packets, reporting on stdout: Debugging Output. (line 236) * packets, tracepoint: Tracepoint Packets. (line 6) * page size: Screen Size. (line 6) * page tables display (MS-DOS): DJGPP Native. (line 55) * pagination: Screen Size. (line 6) * parameters in guile: Parameters In Guile. (line 6) * parameters in python: Parameters In Python. (line 6) * partial symbol dump: Symbols. (line 658) * partial symbol tables, listing GDB's internal: Symbols. (line 684) * Pascal: Summary. (line 35) * Pascal objects, static members display: Print Settings. (line 628) * Pascal support in GDB, limitations: Pascal. (line 6) * pass signals to inferior, remote request: General Query Packets. (line 471) * patching binaries: Patching. (line 6) * patching object files: Files. (line 29) * pause current task (GNU Hurd): Hurd Native. (line 48) * pause current thread (GNU Hurd): Hurd Native. (line 90) * pauses in output: Screen Size. (line 6) * pending breakpoints: Set Breaks. (line 353) * physical address from linear address: DJGPP Native. (line 80) * physname: Debugging Output. (line 72) * pipe, target remote to: Connecting. (line 234) * pipes: Starting. (line 64) * pointer values, in file-i/o protocol: Pointer Values. (line 6) * pointer, finding referent: Print Settings. (line 80) * port rights, GNU Hurd: Hurd Native. (line 84) * port sets, GNU Hurd: Hurd Native. (line 84) * PowerPC architecture: PowerPC. (line 6) * prefix for data files: Data Files. (line 6) * prefix for executable and shared library file names: Files. (line 411) * premature return from system calls: Interrupted System Calls. (line 6) * preprocessor macro expansion, showing the results of: Macros. (line 29) * pretty print arrays: Print Settings. (line 115) * pretty print C++ virtual function tables: Print Settings. (line 639) * pretty-printer commands: Pretty-Printer Commands. (line 6) * print all frame argument values: Print Settings. (line 200) * print an Objective-C object description: The Print Command with Objective-C. (line 11) * print array indexes: Print Settings. (line 125) * print binary values in groups of four bits: Print Settings. (line 141) * print frame argument values for scalars only: Print Settings. (line 200) * print list of auto-loaded canned sequences of commands scripts: Auto-loading sequences. (line 21) * print list of auto-loaded Guile scripts: Guile Auto-loading. (line 23) * print list of auto-loaded Python scripts: Python Auto-loading. (line 23) * print messages on inferior start and exit: Inferiors Connections and Programs. (line 188) * print messages on thread start and exit: Threads. (line 279) * print messages when symbols are loaded: Symbols. (line 639) * print settings: Print Settings. (line 6) * print structures in indented form: Print Settings. (line 475) * print/don't print memory addresses: Print Settings. (line 13) * printing byte arrays: Output Formats. (line 62) * printing data: Data. (line 6) * printing frame argument values: Print Settings. (line 200) * printing frame information: Print Settings. (line 360) * printing memory tag violation information: Print Settings. (line 453) * printing nested structures: Print Settings. (line 408) * printing strings: Output Formats. (line 62) * probe static tracepoint marker: Create and Delete Tracepoints. (line 75) * probing markers, static tracepoints: Set Tracepoints. (line 28) * process detailed status information: Process Information. (line 89) * process ID: Process Information. (line 25) * process info via /proc: Process Information. (line 6) * process list, QNX Neutrino: Process Information. (line 127) * process record and replay: Process Record and Replay. (line 6) * process status register: Registers. (line 31) * processes, multiple: Forks. (line 6) * procfs API calls: Process Information. (line 106) * profiling GDB: Maintenance Commands. (line 582) * program counter register: Registers. (line 31) * program entry point: Backtrace. (line 155) * programming in guile: Guile API. (line 6) * programming in python: Python API. (line 6) * progspaces in guile: Progspaces In Guile. (line 6) * progspaces in python: Progspaces In Python. (line 6) * prologue-end: Symbols. (line 794) * prompt: Prompt. (line 6) * protocol basics, file-i/o: Protocol Basics. (line 6) * protocol-specific representation of datatypes, in file-i/o protocol: Protocol-specific Representation of Datatypes. (line 6) * protocol, GDB remote serial: Overview. (line 14) * python api: Python API. (line 6) * Python architectures: Architectures In Python. (line 6) * Python auto-loading: Python Auto-loading. (line 6) * python commands: Python Commands. (line 6) * python commands, CLI: CLI Commands In Python. (line 6) * python commands, GDB/MI: GDB/MI Commands In Python. (line 6) * python convenience functions: Functions In Python. (line 6) * python directory: Python. (line 10) * python exceptions: Exception Handling. (line 6) * python finish breakpoints: Finish Breakpoints in Python. (line 6) * python functions: Basic Python. (line 31) * python instruction disassembly: Disassembly In Python. (line 6) * python module: Basic Python. (line 31) * python modules: Python modules. (line 6) * python notifications, GDB/MI: GDB/MI Notifications In Python. (line 6) * python pagination: Basic Python. (line 6) * python parameters: Parameters In Python. (line 6) * python pretty printing api: Pretty Printing API. (line 6) * python scripting: Python. (line 6) * python stdout: Basic Python. (line 6) * Python TUI Windows: TUI Windows In Python. (line 6) * python, handle missing debug information: Missing Debug Info In Python. (line 6) * Python, working with types: Types In Python. (line 6) * python, working with values from inferior: Values From Inferior. (line 6) * q packet: Packets. (line 289) * Q packet: Packets. (line 289) * QAllow packet: General Query Packets. (line 44) * qAttached packet: General Query Packets. (line 1452) * qC packet: General Query Packets. (line 55) * QCatchSyscalls packet: General Query Packets. (line 439) * qCRC packet: General Query Packets. (line 65) * QDisableRandomization packet: General Query Packets. (line 82) * QEnvironmentHexEncoded packet: General Query Packets. (line 130) * QEnvironmentReset packet: General Query Packets. (line 183) * QEnvironmentUnset packet: General Query Packets. (line 159) * qfThreadInfo packet: General Query Packets. (line 224) * qGetTIBAddr packet: General Query Packets. (line 281) * qGetTLSAddr packet: General Query Packets. (line 257) * qIsAddressTagged packet: General Query Packets. (line 332) * qMemTags packet: General Query Packets. (line 312) * QMemTags packet: General Query Packets. (line 350) * QNonStop packet: General Query Packets. (line 425) * qOffsets packet: General Query Packets. (line 388) * qP packet: General Query Packets. (line 415) * QPassSignals packet: General Query Packets. (line 471) * QProgramSignals packet: General Query Packets. (line 492) * qRcmd packet: General Query Packets. (line 612) * qSearch memory packet: General Query Packets. (line 633) * QSetWorkingDir packet: General Query Packets. (line 205) * QStartNoAckMode packet: General Query Packets. (line 644) * QStartupWithShell packet: General Query Packets. (line 104) * qsThreadInfo packet: General Query Packets. (line 224) * qSupported packet: General Query Packets. (line 655) * qSymbol packet: General Query Packets. (line 1118) * qTBuffer packet: Tracepoint Packets. (line 380) * QTBuffer size packet: Tracepoint Packets. (line 393) * QTDisable packet: Tracepoint Packets. (line 202) * QTDisconnected packet: Tracepoint Packets. (line 221) * QTDP packet: Tracepoint Packets. (line 10) * QTDPsrc packet: Tracepoint Packets. (line 86) * QTDV packet: Tracepoint Packets. (line 117) * QTEnable packet: Tracepoint Packets. (line 197) * qTfP packet: Tracepoint Packets. (line 328) * QTFrame packet: Tracepoint Packets. (line 129) * qTfSTM packet: Tracepoint Packets. (line 345) * qTfV packet: Tracepoint Packets. (line 336) * QThreadEvents packet: General Query Packets. (line 524) * qThreadExtraInfo packet: General Query Packets. (line 1161) * QThreadOptions packet: General Query Packets. (line 548) * QTinit packet: Tracepoint Packets. (line 207) * qTMinFTPILen packet: Tracepoint Packets. (line 167) * QTNotes packet: Tracepoint Packets. (line 398) * qTP packet: Tracepoint Packets. (line 300) * QTro packet: Tracepoint Packets. (line 210) * QTSave packet: Tracepoint Packets. (line 374) * qTsP packet: Tracepoint Packets. (line 329) * qTsSTM packet: Tracepoint Packets. (line 345) * QTStart packet: Tracepoint Packets. (line 188) * qTStatus packet: Tracepoint Packets. (line 227) * qTSTMat packet: Tracepoint Packets. (line 368) * QTStop packet: Tracepoint Packets. (line 194) * qTsV packet: Tracepoint Packets. (line 337) * qTV packet: Tracepoint Packets. (line 311) * qualified thread ID: Threads. (line 52) * query attached, remote request: General Query Packets. (line 1452) * quotes in commands: Completion. (line 94) * quoting Ada internal identifiers: Additions to Ada. (line 86) * quoting names: Symbols. (line 14) * qXfer packet: General Query Packets. (line 1198) * r packet: Packets. (line 293) * R packet: Packets. (line 298) * range checking: Type Checking. (line 45) * range stepping: Continuing and Stepping. (line 217) * ranged breakpoint: PowerPC Embedded. (line 33) * ranges of breakpoints: Breakpoints. (line 45) * Ravenscar Profile: Ravenscar Profile. (line 6) * Ravenscar thread: Ravenscar Profile. (line 26) * raw printing: Output Formats. (line 77) * read special object, remote request: General Query Packets. (line 1198) * read-only sections: Files. (line 290) * read, file-i/o system call: read. (line 6) * reading symbols from relocatable object files: Files. (line 158) * reading symbols immediately: Files. (line 103) * readline: Editing. (line 6) * Readline application name: Editing. (line 29) * receive rights, GNU Hurd: Hurd Native. (line 84) * recent tracepoint number: Create and Delete Tracepoints. (line 124) * record aggregates (Ada): Omissions from Ada. (line 42) * record mode: Process Record and Replay. (line 19) * record serial communications on file: Remote Configuration. (line 64) * recording a session script: Bug Reporting. (line 93) * recording inferior's execution and replaying it: Process Record and Replay. (line 6) * recordings in python: Recordings In Python. (line 6) * redirection: Input/Output. (line 6) * reference card: Formatting Documentation. (line 6) * reference declarations: C Plus Plus Expressions. (line 50) * register cache, flushing: Maintenance Commands. (line 399) * register packet format, MIPS: MIPS Register packet Format. (line 6) * registers: Registers. (line 6) * Registers In Python: Registers In Python. (line 6) * regular expression: Set Breaks. (line 201) * reloading the overlay table: Overlay Commands. (line 52) * relocatable object files, reading symbols from: Files. (line 158) * remote async notification debugging info: Debugging Output. (line 208) * remote connection commands: Connecting. (line 127) * remote connection without stubs: Server. (line 6) * remote debugging: Remote Debugging. (line 6) * remote debugging, connecting: Connecting. (line 6) * remote debugging, detach and program exit: Connecting. (line 19) * remote debugging, symbol files: Connecting. (line 97) * remote debugging, types of connections: Connecting. (line 6) * remote memory comparison: Memory. (line 159) * remote packets, enabling and disabling: Remote Configuration. (line 159) * remote packets, standard replies: Standard Replies. (line 6) * remote programs, interrupting: Connecting. (line 246) * remote protocol debugging: Debugging Output. (line 236) * remote protocol, binary data: Overview. (line 63) * remote protocol, field separator: Overview. (line 55) * remote query requests: General Query Packets. (line 6) * remote serial debugging summary: Debug Session. (line 6) * remote serial debugging, overview: Remote Stub. (line 14) * remote serial protocol: Overview. (line 14) * remote serial stub: Stub Contents. (line 6) * remote serial stub list: Remote Stub. (line 53) * remote serial stub, initialization: Stub Contents. (line 10) * remote serial stub, main routine: Stub Contents. (line 15) * remote stub, example: Remote Stub. (line 6) * remote stub, support routines: Bootstrapping. (line 6) * remote target: Target Commands. (line 58) * remote target, file transfer: File Transfer. (line 6) * remote target, limit break- and watchpoints: Remote Configuration. (line 79) * remote target, limit watchpoints length: Remote Configuration. (line 91) * remote timeout: Remote Configuration. (line 72) * remove actions from a tracepoint: Tracepoint Actions. (line 21) * remove duplicate history: Command History. (line 69) * rename, file-i/o system call: rename. (line 6) * Renesas: Remote Stub. (line 62) * repeated array elements: Print Settings. (line 394) * repeating command sequences: Command Syntax. (line 41) * repeating commands: Command Syntax. (line 21) * replay log events, remote reply: Stop Reply Packets. (line 70) * replay mode: Process Record and Replay. (line 10) * reporting bugs in GDB: GDB Bugs. (line 6) * reprint the last value: Data. (line 128) * reprint the last value <1>: Compiling and Injecting Code. (line 74) * reset environment, remote request: General Query Packets. (line 183) * resolution of location spec: Location Specifications. (line 14) * resources used by commands: Maintenance Commands. (line 662) * response time, MIPS debugging: MIPS. (line 10) * restart: Checkpoint/Restart. (line 6) * restore data from a file: Dump/Restore Files. (line 6) * restrictions on Go expressions: Go. (line 35) * result records in GDB/MI: GDB/MI Result Records. (line 6) * resume threads of multiple processes simultaneously: All-Stop Mode. (line 68) * resuming execution: Continuing and Stepping. (line 6) * returning from a function: Returning. (line 6) * reverse execution: Reverse Execution. (line 6) * rewind program state: Checkpoint/Restart. (line 6) * run to first instruction: Starting. (line 114) * run to main procedure: Starting. (line 81) * run until specified location: Continuing and Stepping. (line 124) * running: Starting. (line 6) * running programs backward: Reverse Execution. (line 6) * s packet: Packets. (line 305) * S packet: Packets. (line 314) * S12Z support: S12Z. (line 6) * save breakpoints to a file for future sessions: Save Breakpoints. (line 9) * save command history: Command History. (line 44) * save GDB output to a file: Logging Output. (line 6) * save tracepoints for future sessions: save tracepoints. (line 6) * Scalable Matrix Extension: AArch64. (line 46) * Scalable Matrix Extension 2: AArch64. (line 220) * scheduler locking mode: All-Stop Mode. (line 37) * scheduler-locking: All-Stop Mode. (line 37) * scope: M2 Scope. (line 6) * screen size: Screen Size. (line 6) * scripting commands: Command Files. (line 6) * scripting with guile: Guile. (line 6) * scripting with python: Python. (line 6) * search for a thread: Threads. (line 265) * search order for disassembler in Python: Disassembly In Python. (line 466) * search path for libthread_db: Threads. (line 300) * searching memory: Searching Memory. (line 6) * searching memory, in remote debugging: General Query Packets. (line 633) * searching source files: Search. (line 6) * section offsets, remote request: General Query Packets. (line 388) * segment descriptor tables: DJGPP Native. (line 24) * select Ctrl-C, BREAK or BREAK-g: Remote Configuration. (line 108) * select trace snapshot: tfind. (line 6) * selected frame: Stack. (line 19) * selecting guile pretty-printers: Selecting Guile Pretty-Printers. (line 6) * selecting python pretty-printers: Selecting Pretty-Printers. (line 6) * self tests: Maintenance Commands. (line 479) * self tests <1>: Maintenance Commands. (line 485) * self tests <2>: Maintenance Commands. (line 489) * semaphores on static probe points: Static Probe Points. (line 20) * send command to remote monitor: Connecting. (line 279) * send command to simulator: Embedded Processors. (line 9) * send interrupt-sequence on start: Remote Configuration. (line 121) * send rights, GNU Hurd: Hurd Native. (line 84) * send the output of a gdb command to a shell command: Shell Commands. (line 29) * sending files to remote systems: File Transfer. (line 6) * separate debug sections: MiniDebugInfo. (line 6) * separate debugging information files: Separate Debug Files. (line 6) * sequence-id, for GDB remote: Overview. (line 30) * serial connections, debugging: Debugging Output. (line 236) * serial line, target remote: Connecting. (line 136) * serial protocol, GDB remote: Overview. (line 14) * server prefix: Server Prefix. (line 6) * server, command prefix: Command History. (line 20) * set ABI for MIPS: MIPS. (line 32) * set breakpoints in many functions: Set Breaks. (line 201) * set breakpoints on all functions: Set Breaks. (line 228) * set environment variable, remote request: General Query Packets. (line 130) * set exec-file-mismatch: Attach. (line 34) * set fast tracepoint: Create and Delete Tracepoints. (line 50) * set inferior controlling terminal: Input/Output. (line 44) * set static tracepoint: Create and Delete Tracepoints. (line 75) * set tdesc filename: Retrieving Descriptions. (line 18) * set tracepoint: Create and Delete Tracepoints. (line 6) * set working directory, remote request: General Query Packets. (line 205) * setting variables: Assignment. (line 6) * setting watchpoints: Set Watchpoints. (line 6) * settings: Command Settings. (line 39) * SH: Remote Stub. (line 62) * sh-stub.c: Remote Stub. (line 62) * shared libraries: Files. (line 312) * shared library events, remote reply: Stop Reply Packets. (line 65) * shell command, exit code: Convenience Vars. (line 192) * shell command, exit signal: Convenience Vars. (line 192) * shell escape: Shell Commands. (line 10) * show all convenience functions: Convenience Funs. (line 280) * show all user variables and functions: Convenience Vars. (line 37) * show exec-file-mismatch: Attach. (line 44) * show inferior's working directory: Working Directory. (line 27) * show last commands: Command History. (line 110) * show screen characteristics: Maintenance Commands. (line 746) * show tdesc filename: Retrieving Descriptions. (line 25) * signals: Signals. (line 6) * signals the inferior may see, remote request: General Query Packets. (line 492) * SIGQUIT signal, dump core of GDB: Maintenance Commands. (line 213) * SingleKey keymap name: TUI Single Key Mode. (line 71) * size of remote memory accesses: Packets. (line 247) * size of screen: Screen Size. (line 6) * skipping over files via glob-style patterns: Skipping Over Functions and Files. (line 55) * skipping over functions and files: Skipping Over Functions and Files. (line 6) * skipping over functions via regular expressions: Skipping Over Functions and Files. (line 68) * SME: AArch64. (line 46) * SME2: AArch64. (line 220) * snapshot of a process: Checkpoint/Restart. (line 6) * software watchpoints: Set Watchpoints. (line 31) * source code, caching: Maintenance Commands. (line 406) * source code, disable access: Disable Reading Source. (line 6) * source file and line of a symbol: Print Settings. (line 50) * source line and its code address: Machine Code. (line 6) * source location: Location Specifications. (line 6) * source path: Source Path. (line 6) * Sparc: Remote Stub. (line 65) * sparc-stub.c: Remote Stub. (line 65) * Sparc64 support: Sparc64. (line 6) * sparcl-stub.c: Remote Stub. (line 68) * SparcLite: Remote Stub. (line 68) * Special Fortran commands: Special Fortran Commands. (line 6) * specifying location: Location Specifications. (line 6) * SSE registers (x86): Registers. (line 76) * stack frame: Frames. (line 6) * stack on Alpha: MIPS. (line 6) * stack on MIPS: MIPS. (line 6) * stack pointer register: Registers. (line 31) * stacking targets: Active Targets. (line 6) * standard registers: Registers. (line 31) * standard responses for remote packets: Standard Replies. (line 6) * start a new independent interpreter: Interpreters. (line 57) * start a new trace experiment: Starting and Stopping Trace Experiments. (line 6) * starting: Starting. (line 6) * startup code, and backtrace: Backtrace. (line 155) * startup with shell, remote request: General Query Packets. (line 104) * stat, file-i/o system call: stat/fstat. (line 6) * static members of C++ objects: Print Settings. (line 617) * static members of Pascal objects: Print Settings. (line 628) * static probe point, DTrace: Static Probe Points. (line 6) * static probe point, SystemTap: Static Probe Points. (line 6) * static tracepoints: Set Tracepoints. (line 28) * static tracepoints, in remote protocol: General Query Packets. (line 1028) * static tracepoints, setting: Create and Delete Tracepoints. (line 75) * status of trace data collection: Starting and Stopping Trace Experiments. (line 27) * status output in GDB/MI: GDB/MI Output Syntax. (line 94) * stepping: Continuing and Stepping. (line 6) * stepping and signal handlers: Signals. (line 108) * stepping into functions with no line info: Continuing and Stepping. (line 92) * stop a running trace experiment: Starting and Stopping Trace Experiments. (line 16) * stop on C++ exceptions: Set Catchpoints. (line 16) * stop reply packets: Stop Reply Packets. (line 6) * stopped threads: Thread Stops. (line 6) * store memory tags: General Query Packets. (line 350) * stream records in GDB/MI: GDB/MI Stream Records. (line 6) * string tracing, in remote protocol: General Query Packets. (line 1045) * struct gdb_reader_funcs: Writing JIT Debug Info Readers. (line 22) * struct gdb_symbol_callbacks: Writing JIT Debug Info Readers. (line 43) * struct gdb_unwind_callbacks: Writing JIT Debug Info Readers. (line 43) * struct return convention: x86. (line 7) * struct stat, in file-i/o protocol: struct stat. (line 6) * struct timeval, in file-i/o protocol: struct timeval. (line 6) * struct/union returned in registers: x86. (line 7) * structure field name completion: Completion. (line 146) * stub example, remote debugging: Remote Stub. (line 6) * stupid questions: Messages/Warnings. (line 49) * styling: Output Styling. (line 6) * Super-H: Super-H. (line 6) * supported GDB/MI features, list: GDB/MI Support Commands. (line 54) * supported packets, remote query: General Query Packets. (line 655) * svg: AArch64. (line 88) * svl: AArch64. (line 81) * svq: AArch64. (line 85) * switching threads: Threads. (line 6) * switching threads automatically: All-Stop Mode. (line 28) * symbol cache size: Symbols. (line 770) * symbol cache, flushing: Symbols. (line 786) * symbol cache, printing its contents: Symbols. (line 778) * symbol cache, printing usage statistics: Symbols. (line 782) * symbol decoding style, C++: Print Settings. (line 587) * symbol dump: Symbols. (line 658) * symbol file functions: Debugging Output. (line 284) * symbol files, remote debugging: Connecting. (line 97) * symbol from address: Symbols. (line 108) * symbol lookup: Debugging Output. (line 276) * symbol lookup, remote request: General Query Packets. (line 1118) * symbol names: Symbols. (line 14) * symbol table: Files. (line 6) * symbol table creation: Debugging Output. (line 290) * symbol tables in guile: Symbol Tables In Guile. (line 6) * symbol tables in python: Symbol Tables In Python. (line 6) * symbol tables, listing GDB's internal: Symbols. (line 684) * symbol, source file and line: Print Settings. (line 50) * symbols in guile: Symbols In Guile. (line 6) * symbols in python: Symbols In Python. (line 6) * symbols, never read: Files. (line 110) * symbols, reading from relocatable object files: Files. (line 158) * symbols, reading immediately: Files. (line 103) * Synopsys ARC: ARC. (line 6) * syscall DSO: Files. (line 208) * system calls and thread breakpoints: Interrupted System Calls. (line 6) * system root, alternate: Files. (line 411) * system-wide configuration scripts: System-wide Configuration Scripts. (line 6) * system-wide init file: System-wide configuration. (line 6) * system, file-i/o system call: system. (line 6) * t packet: Packets. (line 324) * T packet: Packets. (line 329) * T packet reply: Stop Reply Packets. (line 26) * tail call frames, debugging: Tail Call Frames. (line 6) * target architecture: Targets. (line 17) * target byte order: Byte Order. (line 6) * target character set: Character Sets. (line 6) * target debugging info: Debugging Output. (line 298) * target descriptions: Target Descriptions. (line 6) * target descriptions, AArch64 features: AArch64 Features. (line 5) * target descriptions, ARC Features: ARC Features. (line 6) * target descriptions, ARM features: ARM Features. (line 5) * target descriptions, enum types: Enum Target Types. (line 6) * target descriptions, i386 features: i386 Features. (line 6) * target descriptions, inclusion: Target Description Format. (line 53) * target descriptions, LoongArch Features: LoongArch Features. (line 6) * target descriptions, M68K features: M68K Features. (line 6) * target descriptions, MicroBlaze features: MicroBlaze Features. (line 6) * target descriptions, MIPS features: MIPS Features. (line 6) * target descriptions, NDS32 features: NDS32 Features. (line 6) * target descriptions, Nios II features: Nios II Features. (line 6) * target descriptions, OpenRISC 1000 features: OpenRISC 1000 Features. (line 6) * target descriptions, PowerPC features: PowerPC Features. (line 6) * target descriptions, predefined types: Predefined Target Types. (line 6) * target descriptions, RISC-V Features: RISC-V Features. (line 6) * target descriptions, RX Features: RX Features. (line 6) * target descriptions, S/390 features: S/390 and System z Features. (line 6) * target descriptions, sparc32 features: Sparc Features. (line 6) * target descriptions, sparc64 features: Sparc Features. (line 6) * target descriptions, standard features: Standard Target Features. (line 6) * target descriptions, System z features: S/390 and System z Features. (line 6) * target descriptions, TIC6x features: TIC6x Features. (line 6) * target descriptions, TMS320C6x features: TIC6x Features. (line 6) * target descriptions, XML format: Target Description Format. (line 6) * target memory comparison: Memory. (line 159) * target output in GDB/MI: GDB/MI Output Syntax. (line 110) * target stack description: Maintenance Commands. (line 452) * target-assisted range stepping: Continuing and Stepping. (line 217) * task attributes (GNU Hurd): Hurd Native. (line 48) * task breakpoints, in Ada: Ada Tasks. (line 181) * task exception port, GNU Hurd: Hurd Native. (line 67) * task suspend count: Hurd Native. (line 59) * task switching with program using Ravenscar Profile: Ravenscar Profile. (line 10) * TCP port, target remote: Connecting. (line 173) * temporarily change settings: Command Settings. (line 39) * terminal: Input/Output. (line 6) * Text User Interface: TUI. (line 6) * thread attributes info, remote request: General Query Packets. (line 1161) * thread breakpoints: Thread-Specific Breakpoints. (line 10) * thread breakpoints and system calls: Interrupted System Calls. (line 6) * thread clone events, remote reply: Stop Reply Packets. (line 152) * thread create event, remote reply: Stop Reply Packets. (line 161) * thread create/exit events, remote request: General Query Packets. (line 524) * thread default settings, GNU Hurd: Hurd Native. (line 130) * thread exit event, remote reply: Stop Reply Packets. (line 190) * thread ID lists: Threads. (line 65) * thread identifier (GDB): Threads. (line 47) * thread identifier (system): Threads. (line 35) * thread info (Solaris): Threads. (line 174) * thread information, remote request: General Query Packets. (line 415) * thread list format: Thread List Format. (line 6) * thread number, per inferior: Threads. (line 47) * thread options, remote request: General Query Packets. (line 548) * thread properties, GNU Hurd: Hurd Native. (line 90) * thread suspend count, GNU Hurd: Hurd Native. (line 109) * THREAD-ID, in remote protocol: Packets. (line 20) * threads and watchpoints: Set Watchpoints. (line 182) * threads in python: Threads In Python. (line 6) * threads of execution: Threads. (line 6) * threads, automatic switching: All-Stop Mode. (line 28) * threads, continuing: Thread Stops. (line 6) * threads, stopped: Thread Stops. (line 6) * time of command execution: Maintenance Commands. (line 754) * timeout for called functions: Calling. (line 138) * timeout for called functions <1>: Calling. (line 151) * timeout for called functions <2>: Calling. (line 160) * timeout for called functions <3>: Calling. (line 175) * timeout for commands: Maintenance Commands. (line 844) * timeout for serial communications: Remote Configuration. (line 72) * timeout, for remote target connection: Remote Configuration. (line 147) * timestamping debugging info: Debugging Output. (line 306) * trace experiment, status of: Starting and Stopping Trace Experiments. (line 27) * trace file format: Trace File Format. (line 6) * trace files: Trace Files. (line 6) * trace state variable value, remote request: Tracepoint Packets. (line 311) * trace state variables: Trace State Variables. (line 6) * traceback: Backtrace. (line 6) * traceframe info format: Traceframe Info Format. (line 6) * tracepoint actions: Tracepoint Actions. (line 6) * tracepoint conditions: Tracepoint Conditions. (line 6) * tracepoint data, display: tdump. (line 6) * tracepoint deletion: Create and Delete Tracepoints. (line 127) * tracepoint number: Create and Delete Tracepoints. (line 124) * tracepoint packets: Tracepoint Packets. (line 6) * tracepoint pass count: Tracepoint Passcounts. (line 6) * tracepoint restrictions: Tracepoint Restrictions. (line 6) * tracepoint status, remote request: Tracepoint Packets. (line 300) * tracepoint variables: Tracepoint Variables. (line 6) * tracepoints: Tracepoints. (line 6) * tracepoints support in gdbserver: Server. (line 313) * trailing underscore, in Fortran symbols: Fortran. (line 9) * translating between character sets: Character Sets. (line 6) * TUI: TUI. (line 6) * TUI commands: TUI Commands. (line 6) * TUI configuration variables: TUI Configuration. (line 6) * TUI key bindings: TUI Keys. (line 6) * TUI mouse support: TUI Mouse Support. (line 6) * TUI single key mode: TUI Single Key Mode. (line 6) * type casting memory: Expressions. (line 41) * type chain of a data type: Maintenance Commands. (line 464) * type checking: Checks. (line 24) * type conversions in C++: C Plus Plus Expressions. (line 26) * type printer: Type Printing API. (line 9) * type printing API for Python: Type Printing API. (line 6) * types in guile: Types In Guile. (line 6) * types in Python: Types In Python. (line 6) * UDP port, target remote: Connecting. (line 222) * union field name completion: Completion. (line 146) * unions in structures, printing: Print Settings. (line 527) * Unix domain socket: Connecting. (line 147) * unknown address, locating: Output Formats. (line 36) * unknown type: Symbols. (line 384) * unlink, file-i/o system call: unlink. (line 6) * unlinked object files: Files. (line 29) * unload symbols from shared libraries: Files. (line 373) * unmap an overlay: Overlay Commands. (line 39) * unmapped overlays: How Overlays Work. (line 6) * unset environment variable, remote request: General Query Packets. (line 159) * unset tdesc filename: Retrieving Descriptions. (line 21) * unsupported languages: Unsupported Languages. (line 6) * unsupported packets, empty response for: Standard Replies. (line 11) * unwind stack in called functions: Calling. (line 36) * unwind stack in called functions when timing out: Calling. (line 65) * unwind stack in called functions with unhandled exceptions: Calling. (line 53) * unwinding frames in Python: Unwinding Frames in Python. (line 6) * use only software watchpoints: Set Watchpoints. (line 111) * user registers: Maintenance Commands. (line 423) * user-defined command: Define. (line 6) * user-defined macros: Macros. (line 60) * user-defined variables: Convenience Vars. (line 6) * value history: Value History. (line 6) * values from inferior, in guile: Values From Inferior In Guile. (line 6) * values from inferior, with Python: Values From Inferior. (line 6) * variable name conflict: Variables. (line 36) * variable object debugging info: Debugging Output. (line 314) * variable objects in GDB/MI: GDB/MI Variable Objects. (line 9) * variable values, wrong: Variables. (line 106) * variables, readline: Readline Init File Syntax. (line 34) * variables, setting: Assignment. (line 16) * vAttach packet: Packets. (line 341) * vCont packet: Packets. (line 357) * vCont? packet: Packets. (line 424) * vCtrlC packet: Packets. (line 432) * vector unit: Vector Unit. (line 6) * vector, auxiliary: OS Information. (line 9) * verbose operation: Messages/Warnings. (line 6) * verify remote memory image: Memory. (line 159) * verify target memory image: Memory. (line 159) * vFile packet: Packets. (line 444) * vFlashDone packet: Packets. (line 479) * vFlashErase packet: Packets. (line 448) * vFlashWrite packet: Packets. (line 461) * vfork events, remote reply: Stop Reply Packets. (line 116) * vforkdone events, remote reply: Stop Reply Packets. (line 128) * vg: AArch64. (line 41) * virtual functions (C++) display: Print Settings. (line 639) * vKill packet: Packets. (line 486) * vl: AArch64. (line 35) * vMustReplyEmpty packet: Packets. (line 496) * volatile registers: Registers. (line 106) * vq: AArch64. (line 38) * vRun packet: Packets. (line 508) * vStopped packet: Packets. (line 521) * VTBL display: Print Settings. (line 639) * watchdog timer: Maintenance Commands. (line 844) * watchpoints: Breakpoints. (line 17) * watchpoints and threads: Set Watchpoints. (line 182) * wavefronts: AMD GPU. (line 40) * where to look for shared libraries: Files. (line 406) * wild pointer, interpreting: Print Settings. (line 80) * Wind River Linux system-wide configuration script: System-wide Configuration Scripts. (line 22) * word completion: Completion. (line 6) * working directory: Source Path. (line 40) * working directory (of your program): Working Directory. (line 6) * working language: Languages. (line 13) * write data into object, remote request: General Query Packets. (line 1420) * write, file-i/o system call: write. (line 6) * writing a frame filter: Writing a Frame Filter. (line 6) * writing a Guile pretty-printer: Writing a Guile Pretty-Printer. (line 6) * writing a pretty-printer: Writing a Pretty-Printer. (line 6) * writing convenience functions: Functions In Python. (line 6) * writing into corefiles: Patching. (line 6) * writing into executables: Patching. (line 6) * writing into executables <1>: Compiling and Injecting Code. (line 6) * writing JIT debug info readers: Writing JIT Debug Info Readers. (line 6) * writing xmethods in Python: Writing an Xmethod. (line 6) * wrong values: Variables. (line 106) * x command, default address: Machine Code. (line 35) * X packet: Packets. (line 524) * Xilinx MicroBlaze: MicroBlaze. (line 6) * XInclude: Target Description Format. (line 53) * XMD, Xilinx Microprocessor Debugger: MicroBlaze. (line 6) * xmethod API: Xmethod API. (line 6) * xmethods in Python: Xmethods In Python. (line 6) * XML parser debugging: Debugging Output. (line 321) * yanking text: Readline Killing Commands. (line 6) * z packet: Packets. (line 535) * Z packets: Packets. (line 535) * z0 packet: Packets. (line 550) * Z0 packet: Packets. (line 550) * z1 packet: Packets. (line 601) * Z1 packet: Packets. (line 601) * z2 packet: Packets. (line 618) * Z2 packet: Packets. (line 618) * z3 packet: Packets. (line 627) * Z3 packet: Packets. (line 627) * z4 packet: Packets. (line 636) * Z4 packet: Packets. (line 636)  File: gdb.info, Node: Command and Variable Index, Prev: Concept Index, Up: Top Command, Variable, and Function Index ************************************* [index] * Menu: * __init__ on TypePrinter: gdb.types. (line 82) * -ada-task-info: GDB/MI Ada Tasking Commands. (line 6) * -add-inferior: GDB/MI Miscellaneous Commands. (line 292) * -break-after: GDB/MI Breakpoint Commands. (line 8) * -break-commands: GDB/MI Breakpoint Commands. (line 53) * -break-condition: GDB/MI Breakpoint Commands. (line 87) * -break-delete: GDB/MI Breakpoint Commands. (line 127) * -break-disable: GDB/MI Breakpoint Commands. (line 161) * -break-enable: GDB/MI Breakpoint Commands. (line 197) * -break-info: GDB/MI Breakpoint Commands. (line 232) * -break-insert: GDB/MI Breakpoint Commands. (line 256) * -break-list: GDB/MI Breakpoint Commands. (line 445) * -break-passcount: GDB/MI Breakpoint Commands. (line 517) * -break-watch: GDB/MI Breakpoint Commands. (line 529) * -catch-assert: Ada Exception GDB/MI Catchpoint Commands. (line 9) * -catch-catch: C++ Exception GDB/MI Catchpoint Commands. (line 95) * -catch-exception: Ada Exception GDB/MI Catchpoint Commands. (line 43) * -catch-handlers: Ada Exception GDB/MI Catchpoint Commands. (line 88) * -catch-load: Shared Library GDB/MI Catchpoint Commands. (line 6) * -catch-rethrow: C++ Exception GDB/MI Catchpoint Commands. (line 53) * -catch-throw: C++ Exception GDB/MI Catchpoint Commands. (line 10) * -catch-unload: Shared Library GDB/MI Catchpoint Commands. (line 33) * -complete: GDB/MI Miscellaneous Commands. (line 491) * -data-disassemble: GDB/MI Data Manipulation. (line 12) * -data-evaluate-expression: GDB/MI Data Manipulation. (line 244) * -data-list-changed-registers: GDB/MI Data Manipulation. (line 282) * -data-list-register-names: GDB/MI Data Manipulation. (line 318) * -data-list-register-values: GDB/MI Data Manipulation. (line 358) * -data-read-memory: GDB/MI Data Manipulation. (line 445) * -data-read-memory-bytes: GDB/MI Data Manipulation. (line 552) * -data-write-memory-bytes: GDB/MI Data Manipulation. (line 627) * -dprintf-insert: GDB/MI Breakpoint Commands. (line 374) * -enable-frame-filters: GDB/MI Stack Manipulation. (line 6) * -enable-pretty-printing: GDB/MI Variable Objects. (line 115) * -enable-timings: GDB/MI Miscellaneous Commands. (line 447) * -environment-cd: GDB/MI Program Context. (line 30) * -environment-directory: GDB/MI Program Context. (line 53) * -environment-path: GDB/MI Program Context. (line 97) * -environment-pwd: GDB/MI Program Context. (line 138) * -exec-arguments: GDB/MI Program Context. (line 6) * -exec-continue: GDB/MI Program Execution. (line 10) * -exec-finish: GDB/MI Program Execution. (line 63) * -exec-interrupt: GDB/MI Program Execution. (line 107) * -exec-jump: GDB/MI Program Execution. (line 157) * -exec-next: GDB/MI Program Execution. (line 181) * -exec-next-instruction: GDB/MI Program Execution. (line 212) * -exec-return: GDB/MI Program Execution. (line 248) * -exec-run: GDB/MI Program Execution. (line 293) * -exec-step: GDB/MI Program Execution. (line 363) * -exec-step-instruction: GDB/MI Program Execution. (line 405) * -exec-until: GDB/MI Program Execution. (line 446) * -file-exec-and-symbols: GDB/MI File Commands. (line 9) * -file-exec-file: GDB/MI File Commands. (line 37) * -file-list-exec-source-file: GDB/MI File Commands. (line 64) * -file-list-exec-source-files: GDB/MI File Commands. (line 90) * -file-list-shared-libraries: GDB/MI File Commands. (line 222) * -file-symbol-file: GDB/MI File Commands. (line 256) * -gdb-exit: GDB/MI Miscellaneous Commands. (line 6) * -gdb-set: GDB/MI Miscellaneous Commands. (line 28) * -gdb-show: GDB/MI Miscellaneous Commands. (line 51) * -gdb-version: GDB/MI Miscellaneous Commands. (line 74) * -inferior-tty-set: GDB/MI Miscellaneous Commands. (line 398) * -inferior-tty-show: GDB/MI Miscellaneous Commands. (line 421) * -info-ada-exceptions: GDB/MI Ada Exceptions Commands. (line 6) * -info-gdb-mi-command: GDB/MI Support Commands. (line 11) * -info-os: GDB/MI Miscellaneous Commands. (line 218) * -interpreter-exec: GDB/MI Miscellaneous Commands. (line 372) * -list-features: GDB/MI Support Commands. (line 54) * -list-target-features: GDB/MI Support Commands. (line 119) * -list-thread-groups: GDB/MI Miscellaneous Commands. (line 108) * -remove-inferior: GDB/MI Miscellaneous Commands. (line 341) * -stack-info-depth: GDB/MI Stack Manipulation. (line 48) * -stack-info-frame: GDB/MI Stack Manipulation. (line 21) * -stack-list-arguments: GDB/MI Stack Manipulation. (line 86) * -stack-list-frames: GDB/MI Stack Manipulation. (line 185) * -stack-list-locals: GDB/MI Stack Manipulation. (line 302) * -stack-list-variables: GDB/MI Stack Manipulation. (line 348) * -stack-select-frame: GDB/MI Stack Manipulation. (line 376) * -symbol-info-functions: GDB/MI Symbol Query. (line 6) * -symbol-info-module-functions: GDB/MI Symbol Query. (line 106) * -symbol-info-module-variables: GDB/MI Symbol Query. (line 167) * -symbol-info-modules: GDB/MI Symbol Query. (line 238) * -symbol-info-types: GDB/MI Symbol Query. (line 292) * -symbol-info-variables: GDB/MI Symbol Query. (line 349) * -symbol-list-lines: GDB/MI Symbol Query. (line 454) * -target-attach: GDB/MI Target Manipulation. (line 6) * -target-detach: GDB/MI Target Manipulation. (line 33) * -target-disconnect: GDB/MI Target Manipulation. (line 58) * -target-download: GDB/MI Target Manipulation. (line 82) * -target-file-delete: GDB/MI File Transfer Commands. (line 54) * -target-file-get: GDB/MI File Transfer Commands. (line 30) * -target-file-put: GDB/MI File Transfer Commands. (line 6) * -target-flash-erase: GDB/MI Target Manipulation. (line 189) * -target-select: GDB/MI Target Manipulation. (line 209) * -thread-info: GDB/MI Thread Commands. (line 6) * -thread-list-ids: GDB/MI Thread Commands. (line 55) * -thread-select: GDB/MI Thread Commands. (line 83) * -trace-define-variable: GDB/MI Tracepoint Commands. (line 77) * -trace-find: GDB/MI Tracepoint Commands. (line 9) * -trace-frame-collected: GDB/MI Tracepoint Commands. (line 94) * -trace-list-variables: GDB/MI Tracepoint Commands. (line 201) * -trace-save: GDB/MI Tracepoint Commands. (line 243) * -trace-start: GDB/MI Tracepoint Commands. (line 264) * -trace-status: GDB/MI Tracepoint Commands. (line 280) * -trace-stop: GDB/MI Tracepoint Commands. (line 351) * -var-assign: GDB/MI Variable Objects. (line 492) * -var-create: GDB/MI Variable Objects. (line 130) * -var-delete: GDB/MI Variable Objects. (line 219) * -var-evaluate-expression: GDB/MI Variable Objects. (line 471) * -var-info-expression: GDB/MI Variable Objects. (line 408) * -var-info-num-children: GDB/MI Variable Objects. (line 273) * -var-info-path-expression: GDB/MI Variable Objects. (line 433) * -var-info-type: GDB/MI Variable Objects. (line 395) * -var-list-children: GDB/MI Variable Objects. (line 289) * -var-set-format: GDB/MI Variable Objects. (line 232) * -var-set-frozen: GDB/MI Variable Objects. (line 636) * -var-set-update-range: GDB/MI Variable Objects. (line 662) * -var-set-visualizer: GDB/MI Variable Objects. (line 685) * -var-show-attributes: GDB/MI Variable Objects. (line 457) * -var-show-format: GDB/MI Variable Objects. (line 260) * -var-update: GDB/MI Variable Objects. (line 516) * !: Shell Commands. (line 10) * @@, referencing memory as an array: Arrays. (line 6) * # (a comment): Command Syntax. (line 37) * ^connected: GDB/MI Result Records. (line 21) * ^done: GDB/MI Result Records. (line 9) * ^error: GDB/MI Result Records. (line 24) * ^exit: GDB/MI Result Records. (line 35) * ^running: GDB/MI Result Records. (line 13) * : Architectures In Guile. (line 6) * : Blocks In Guile. (line 6) * : Breakpoints In Guile. (line 6) * : Iterators In Guile. (line 6) * : Lazy Strings In Guile. (line 6) * : Objfiles In Guile. (line 6) * : Progspaces In Guile. (line 6) * : Symbol Tables In Guile. (line 6) * : Symbols In Guile. (line 6) * : Symbol Tables In Guile. (line 6) * : Types In Guile. (line 6) * : Values From Inferior In Guile. (line 6) * |: Shell Commands. (line 29) * $__, convenience variable: Convenience Vars. (line 74) * $_, convenience variable: Convenience Vars. (line 65) * $_ada_exception, convenience variable: Set Catchpoints. (line 82) * $_any_caller_is, convenience function: Convenience Funs. (line 229) * $_any_caller_matches, convenience function: Convenience Funs. (line 241) * $_as_string, convenience function: Convenience Funs. (line 253) * $_caller_is, convenience function: Convenience Funs. (line 199) * $_caller_matches, convenience function: Convenience Funs. (line 222) * $_cimag, convenience function: Convenience Funs. (line 267) * $_creal, convenience function: Convenience Funs. (line 267) * $_exception, convenience variable: Set Catchpoints. (line 21) * $_exitcode, convenience variable: Convenience Vars. (line 80) * $_exitsignal, convenience variable: Convenience Vars. (line 85) * $_gdb_maint_setting_str, convenience function: Convenience Funs. (line 124) * $_gdb_maint_setting, convenience function: Convenience Funs. (line 128) * $_gdb_major, convenience variable: Convenience Vars. (line 183) * $_gdb_minor, convenience variable: Convenience Vars. (line 183) * $_gdb_setting_str, convenience function: Convenience Funs. (line 62) * $_gdb_setting, convenience function: Convenience Funs. (line 75) * $_gthread, convenience variable: Threads. (line 98) * $_hit_bpnum, convenience variable: Set Breaks. (line 24) * $_hit_locno, convenience variable: Set Breaks. (line 24) * $_inferior_thread_count, convenience variable: Threads. (line 98) * $_inferior, convenience variable: Inferiors Connections and Programs. (line 107) * $_isvoid, convenience function: Convenience Funs. (line 14) * $_memeq, convenience function: Convenience Funs. (line 183) * $_probe_arg, convenience variable: Static Probe Points. (line 77) * $_regex, convenience function: Convenience Funs. (line 187) * $_sdata, collect: Tracepoint Actions. (line 86) * $_sdata, inspect, convenience variable: Convenience Vars. (line 147) * $_shell_exitcode, convenience variable: Convenience Vars. (line 192) * $_shell_exitsignal, convenience variable: Convenience Vars. (line 192) * $_shell, convenience function: Convenience Funs. (line 132) * $_siginfo, convenience variable: Convenience Vars. (line 153) * $_streq, convenience function: Convenience Funs. (line 192) * $_strlen, convenience function: Convenience Funs. (line 196) * $_thread, convenience variable: Threads. (line 98) * $_tlb, convenience variable: Convenience Vars. (line 159) * $bpnum, convenience variable: Set Breaks. (line 6) * $cdir, convenience variable: Source Path. (line 40) * $cwd, convenience variable: Source Path. (line 40) * $tpnum: Create and Delete Tracepoints. (line 124) * $trace_file: Tracepoint Variables. (line 16) * $trace_frame: Tracepoint Variables. (line 6) * $trace_func: Tracepoint Variables. (line 19) * $trace_line: Tracepoint Variables. (line 13) * $tracepoint: Tracepoint Variables. (line 10) * abort (C-g): Miscellaneous Commands. (line 10) * accept-line (Newline or Return): Commands For History. (line 6) * actions: Tracepoint Actions. (line 6) * ada-task-info: GDB/MI Support Commands. (line 94) * add-auto-load-safe-path: Auto-loading safe path. (line 50) * add-auto-load-scripts-directory: objfile-gdbdotext file. (line 68) * add-inferior: Inferiors Connections and Programs. (line 119) * add-symbol-file: Files. (line 132) * add-symbol-file-from-memory: Files. (line 208) * adi assign: Sparc64. (line 45) * adi examine: Sparc64. (line 27) * advance LOCSPEC: Continuing and Stepping. (line 187) * alias: Aliases. (line 21) * append: Dump/Restore Files. (line 34) * append-pretty-printer!: Guile Printing Module. (line 18) * apropos: Help. (line 82) * arch-bool-type: Architectures In Guile. (line 84) * arch-char-type: Architectures In Guile. (line 36) * arch-charset: Architectures In Guile. (line 23) * arch-disassemble: Disassembly In Guile. (line 10) * arch-double-type: Architectures In Guile. (line 76) * arch-float-type: Architectures In Guile. (line 72) * arch-int-type: Architectures In Guile. (line 44) * arch-int16-type: Architectures In Guile. (line 104) * arch-int32-type: Architectures In Guile. (line 112) * arch-int64-type: Architectures In Guile. (line 120) * arch-int8-type: Architectures In Guile. (line 96) * arch-long-type: Architectures In Guile. (line 48) * arch-longdouble-type: Architectures In Guile. (line 80) * arch-longlong-type: Architectures In Guile. (line 88) * arch-name: Architectures In Guile. (line 20) * arch-schar-type: Architectures In Guile. (line 52) * arch-short-type: Architectures In Guile. (line 40) * arch-uchar-type: Architectures In Guile. (line 56) * arch-uint-type: Architectures In Guile. (line 64) * arch-uint16-type: Architectures In Guile. (line 108) * arch-uint32-type: Architectures In Guile. (line 116) * arch-uint64-type: Architectures In Guile. (line 124) * arch-uint8-type: Architectures In Guile. (line 100) * arch-ulong-type: Architectures In Guile. (line 68) * arch-ulonglong-type: Architectures In Guile. (line 92) * arch-ushort-type: Architectures In Guile. (line 60) * arch-void-type: Architectures In Guile. (line 32) * arch-wide-charset: Architectures In Guile. (line 26) * arch?: Architectures In Guile. (line 13) * Architecture.disassemble: Architectures In Python. (line 15) * Architecture.integer_type: Architectures In Python. (line 47) * Architecture.name: Architectures In Python. (line 12) * Architecture.register_groups: Architectures In Python. (line 67) * Architecture.registers: Architectures In Python. (line 61) * attach: Attach. (line 6) * attach&: Background Execution. (line 25) * awatch: Set Watchpoints. (line 86) * b (break): Set Breaks. (line 6) * backtrace: Backtrace. (line 11) * backward-char (C-b): Commands For Moving. (line 15) * backward-delete-char (Rubout): Commands For Text. (line 17) * backward-kill-line (C-x Rubout): Commands For Killing. (line 11) * backward-kill-word (M-): Commands For Killing. (line 28) * backward-word (M-b): Commands For Moving. (line 22) * beginning-of-history (M-<): Commands For History. (line 19) * beginning-of-line (C-a): Commands For Moving. (line 6) * bell-style: Readline Init File Syntax. (line 35) * bfd caching: File Caching. (line 14) * bfd caching <1>: File Caching. (line 24) * bfd caching <2>: File Caching. (line 27) * bind-tty-special-chars: Readline Init File Syntax. (line 42) * blink-matching-paren: Readline Init File Syntax. (line 47) * block-end: Blocks In Guile. (line 70) * block-function: Blocks In Guile. (line 73) * block-global-block: Blocks In Guile. (line 87) * block-global?: Blocks In Guile. (line 93) * block-start: Blocks In Guile. (line 67) * block-static-block: Blocks In Guile. (line 90) * block-static?: Blocks In Guile. (line 97) * block-superblock: Blocks In Guile. (line 83) * block-symbols: Blocks In Guile. (line 101) * block-symbols-progress?: Blocks In Guile. (line 112) * block-valid?: Blocks In Guile. (line 59) * block?: Blocks In Guile. (line 55) * Block.end: Blocks In Python. (line 86) * Block.function: Blocks In Python. (line 90) * Block.global_block: Blocks In Python. (line 105) * Block.is_global: Blocks In Python. (line 113) * Block.is_static: Blocks In Python. (line 117) * Block.is_valid: Blocks In Python. (line 73) * Block.start: Blocks In Python. (line 83) * Block.static_block: Blocks In Python. (line 109) * Block.superblock: Blocks In Python. (line 100) * BP_ACCESS_WATCHPOINT: Breakpoints In Python. (line 77) * BP_ACCESS_WATCHPOINT <1>: Breakpoints In Guile. (line 77) * BP_BREAKPOINT: Breakpoints In Python. (line 62) * BP_BREAKPOINT <1>: Breakpoints In Guile. (line 63) * BP_CATCHPOINT: Breakpoints In Python. (line 80) * BP_CATCHPOINT <1>: Breakpoints In Guile. (line 81) * BP_HARDWARE_BREAKPOINT: Breakpoints In Python. (line 65) * BP_HARDWARE_WATCHPOINT: Breakpoints In Python. (line 71) * BP_HARDWARE_WATCHPOINT <1>: Breakpoints In Guile. (line 69) * BP_READ_WATCHPOINT: Breakpoints In Python. (line 74) * BP_READ_WATCHPOINT <1>: Breakpoints In Guile. (line 73) * BP_WATCHPOINT: Breakpoints In Python. (line 68) * BP_WATCHPOINT <1>: Breakpoints In Guile. (line 66) * bracketed-paste-begin (): Commands For Text. (line 36) * break: Set Breaks. (line 6) * break ... inferior INFERIOR-ID: Inferior-Specific Breakpoints. (line 9) * break ... task TASKNO (Ada): Ada Tasks. (line 181) * break ... thread THREAD-ID: Thread-Specific Breakpoints. (line 10) * break-range: PowerPC Embedded. (line 41) * break, and Objective-C: Method Names in Commands. (line 9) * breakpoint annotation: Annotations for Running. (line 47) * breakpoint-commands: Breakpoints In Guile. (line 254) * breakpoint-condition: Breakpoints In Guile. (line 212) * breakpoint-enabled?: Breakpoints In Guile. (line 162) * breakpoint-expression: Breakpoints In Guile. (line 157) * breakpoint-hit-count: Breakpoints In Guile. (line 187) * breakpoint-ignore-count: Breakpoints In Guile. (line 181) * breakpoint-location: Breakpoints In Guile. (line 152) * breakpoint-notifications: GDB/MI Support Commands. (line 91) * breakpoint-number: Breakpoints In Guile. (line 132) * breakpoint-silent?: Breakpoints In Guile. (line 169) * breakpoint-stop: Breakpoints In Guile. (line 220) * breakpoint-task: Breakpoints In Guile. (line 203) * breakpoint-temporary?: Breakpoints In Guile. (line 136) * breakpoint-thread: Breakpoints In Guile. (line 194) * breakpoint-type: Breakpoints In Guile. (line 144) * breakpoint-valid?: Breakpoints In Guile. (line 122) * breakpoint-visible?: Breakpoints In Guile. (line 148) * breakpoint?: Breakpoints In Guile. (line 118) * Breakpoint.__init__: Breakpoints In Python. (line 16) * Breakpoint.__init__ <1>: Breakpoints In Python. (line 49) * Breakpoint.commands: Breakpoints In Python. (line 242) * Breakpoint.condition: Breakpoints In Python. (line 237) * Breakpoint.delete: Breakpoints In Python. (line 137) * Breakpoint.enabled: Breakpoints In Python. (line 142) * Breakpoint.expression: Breakpoints In Python. (line 231) * Breakpoint.hit_count: Breakpoints In Python. (line 211) * Breakpoint.ignore_count: Breakpoints In Python. (line 183) * Breakpoint.inferior: Breakpoints In Python. (line 169) * Breakpoint.is_valid: Breakpoints In Python. (line 129) * Breakpoint.location: Breakpoints In Python. (line 216) * Breakpoint.locations: Breakpoints In Python. (line 222) * Breakpoint.number: Breakpoints In Python. (line 187) * Breakpoint.pending: Breakpoints In Python. (line 155) * Breakpoint.silent: Breakpoints In Python. (line 147) * Breakpoint.stop: Breakpoints In Python. (line 98) * Breakpoint.task: Breakpoints In Python. (line 177) * Breakpoint.temporary: Breakpoints In Python. (line 202) * Breakpoint.thread: Breakpoints In Python. (line 159) * Breakpoint.type: Breakpoints In Python. (line 192) * Breakpoint.visible: Breakpoints In Python. (line 197) * BreakpointEvent.breakpoint: Events In Python. (line 126) * BreakpointEvent.breakpoints: Events In Python. (line 121) * BreakpointLocation.address: Breakpoints In Python. (line 270) * BreakpointLocation.enabled: Breakpoints In Python. (line 276) * BreakpointLocation.fullname: Breakpoints In Python. (line 293) * BreakpointLocation.function: Breakpoints In Python. (line 287) * BreakpointLocation.owner: Breakpoints In Python. (line 281) * BreakpointLocation.source: Breakpoints In Python. (line 262) * BreakpointLocation.thread_groups: Breakpoints In Python. (line 299) * breakpoints: Breakpoints In Guile. (line 114) * breakpoints-invalid annotation: Invalidation. (line 14) * bt (backtrace): Backtrace. (line 11) * builtin_disassemble: Disassembly In Python. (line 493) * c (continue): Continuing and Stepping. (line 16) * c (SingleKey TUI key): TUI Single Key Mode. (line 10) * C (SingleKey TUI key): TUI Single Key Mode. (line 13) * C-L: TUI Keys. (line 79) * C-x 1: TUI Keys. (line 22) * C-x 2: TUI Keys. (line 32) * C-x a: TUI Keys. (line 11) * C-x A: TUI Keys. (line 12) * C-x C-a: TUI Keys. (line 10) * C-x o: TUI Keys. (line 43) * C-x s: TUI Keys. (line 53) * call: Calling. (line 11) * call-last-kbd-macro (C-x e): Keyboard Macros. (line 13) * capitalize-word (M-c): Commands For Text. (line 69) * catch: Set Catchpoints. (line 10) * catch assert: Set Catchpoints. (line 112) * catch catch: Set Catchpoints. (line 16) * catch exception: Set Catchpoints. (line 66) * catch exception unhandled: Set Catchpoints. (line 87) * catch exec: Set Catchpoints. (line 116) * catch fork: Set Catchpoints. (line 261) * catch handlers: Set Catchpoints. (line 92) * catch load: Set Catchpoints. (line 268) * catch rethrow: Set Catchpoints. (line 16) * catch signal: Set Catchpoints. (line 273) * catch syscall: Set Catchpoints. (line 120) * catch throw: Set Catchpoints. (line 16) * catch unload: Set Catchpoints. (line 268) * catch vfork: Set Catchpoints. (line 264) * cd: Working Directory. (line 32) * cdir: Source Path. (line 40) * character-search (C-]): Miscellaneous Commands. (line 42) * character-search-backward (M-C-]): Miscellaneous Commands. (line 47) * checkpoint: Checkpoint/Restart. (line 26) * clear: Delete Breaks. (line 21) * clear-display (M-C-l): Commands For Moving. (line 40) * clear-screen (C-l): Commands For Moving. (line 45) * clear, and Objective-C: Method Names in Commands. (line 9) * ClearObjFilesEvent.progspace: Events In Python. (line 157) * clone-inferior: Inferiors Connections and Programs. (line 135) * collect (tracepoints): Tracepoint Actions. (line 49) * colon-colon, in Modula-2: M2 Scope. (line 6) * colored-completion-prefix: Readline Init File Syntax. (line 52) * colored-stats: Readline Init File Syntax. (line 59) * COMMAND_BREAKPOINTS: CLI Commands In Python. (line 144) * COMMAND_BREAKPOINTS <1>: Commands In Guile. (line 177) * COMMAND_DATA: CLI Commands In Python. (line 115) * COMMAND_DATA <1>: Commands In Guile. (line 148) * COMMAND_FILES: CLI Commands In Python. (line 126) * COMMAND_FILES <1>: Commands In Guile. (line 159) * COMMAND_MAINTENANCE: CLI Commands In Python. (line 173) * COMMAND_MAINTENANCE <1>: Commands In Guile. (line 201) * COMMAND_NONE: CLI Commands In Python. (line 105) * COMMAND_NONE <1>: Commands In Guile. (line 137) * COMMAND_OBSCURE: CLI Commands In Python. (line 167) * COMMAND_OBSCURE <1>: Commands In Guile. (line 195) * COMMAND_RUNNING: CLI Commands In Python. (line 109) * COMMAND_RUNNING <1>: Commands In Guile. (line 142) * COMMAND_STACK: CLI Commands In Python. (line 120) * COMMAND_STACK <1>: Commands In Guile. (line 153) * COMMAND_STATUS: CLI Commands In Python. (line 138) * COMMAND_STATUS <1>: Commands In Guile. (line 171) * COMMAND_SUPPORT: CLI Commands In Python. (line 131) * COMMAND_SUPPORT <1>: Commands In Guile. (line 164) * COMMAND_TRACEPOINTS: CLI Commands In Python. (line 150) * COMMAND_TRACEPOINTS <1>: Commands In Guile. (line 183) * COMMAND_TUI: CLI Commands In Python. (line 156) * COMMAND_USER: CLI Commands In Python. (line 161) * COMMAND_USER <1>: Commands In Guile. (line 189) * command?: Commands In Guile. (line 63) * Command.__init__: CLI Commands In Python. (line 10) * Command.complete: CLI Commands In Python. (line 72) * Command.dont_repeat: CLI Commands In Python. (line 42) * Command.invoke: CLI Commands In Python. (line 50) * commands: Break Commands. (line 11) * commands annotation: Prompting. (line 27) * comment-begin: Readline Init File Syntax. (line 65) * compare-sections: Memory. (line 166) * compile code: Compiling and Injecting Code. (line 11) * compile file: Compiling and Injecting Code. (line 56) * complete: Help. (line 114) * complete (): Commands For Completion. (line 6) * COMPLETE_COMMAND: CLI Commands In Python. (line 194) * COMPLETE_COMMAND <1>: Commands In Guile. (line 222) * COMPLETE_EXPRESSION: CLI Commands In Python. (line 202) * COMPLETE_EXPRESSION <1>: Commands In Guile. (line 230) * COMPLETE_FILENAME: CLI Commands In Python. (line 187) * COMPLETE_FILENAME <1>: Commands In Guile. (line 215) * COMPLETE_LOCATION: CLI Commands In Python. (line 190) * COMPLETE_LOCATION <1>: Commands In Guile. (line 218) * COMPLETE_NONE: CLI Commands In Python. (line 184) * COMPLETE_NONE <1>: Commands In Guile. (line 212) * COMPLETE_SYMBOL: CLI Commands In Python. (line 198) * COMPLETE_SYMBOL <1>: Commands In Guile. (line 226) * completion-display-width: Readline Init File Syntax. (line 70) * completion-ignore-case: Readline Init File Syntax. (line 77) * completion-map-case: Readline Init File Syntax. (line 82) * completion-prefix-display-length: Readline Init File Syntax. (line 88) * completion-query-items: Readline Init File Syntax. (line 95) * condition: Conditions. (line 58) * ConnectionEvent.connection: Events In Python. (line 279) * continue: Continuing and Stepping. (line 16) * continue&: Background Execution. (line 40) * convert-meta: Readline Init File Syntax. (line 105) * copy-backward-word (): Commands For Killing. (line 60) * copy-forward-word (): Commands For Killing. (line 65) * copy-region-as-kill (): Commands For Killing. (line 56) * core-file: Files. (line 116) * ctf: Trace Files. (line 28) * Ctrl-o (operate-and-get-next): Command Syntax. (line 41) * current-arch: Architectures In Guile. (line 17) * current-objfile: Objfiles In Guile. (line 46) * current-progspace: Progspaces In Guile. (line 26) * cwd: Source Path. (line 40) * d (delete): Delete Breaks. (line 56) * d (SingleKey TUI key): TUI Single Key Mode. (line 16) * data-directory: Guile Configuration. (line 9) * data-disassemble-a-option: GDB/MI Support Commands. (line 108) * data-read-memory-bytes: GDB/MI Support Commands. (line 88) * default-visualizer: Guile Pretty Printing API. (line 130) * define: Define. (line 50) * define-prefix: Define. (line 82) * delete: Delete Breaks. (line 56) * delete checkpoint CHECKPOINT-ID: Checkpoint/Restart. (line 53) * delete display: Auto Display. (line 45) * delete mem: Memory Region Attributes. (line 34) * delete tracepoint: Create and Delete Tracepoints. (line 127) * delete tvariable: Trace State Variables. (line 42) * delete-breakpoint!: Breakpoints In Guile. (line 105) * delete-char (C-d): Commands For Text. (line 12) * delete-char-or-list (): Commands For Completion. (line 39) * delete-horizontal-space (): Commands For Killing. (line 48) * demangle: Symbols. (line 127) * detach: Attach. (line 55) * detach (remote): Connecting. (line 263) * detach inferiors INFNO...: Inferiors Connections and Programs. (line 168) * digit-argument (M-0, M-1, ... M--): Numeric Arguments. (line 6) * dir: Source Path. (line 99) * directory: Source Path. (line 99) * dis (disable): Disabling. (line 37) * disable: Disabling. (line 37) * disable display: Auto Display. (line 56) * disable frame-filter: Frame Filter Management. (line 16) * disable mem: Memory Region Attributes. (line 38) * disable pretty-printer: Pretty-Printer Commands. (line 20) * disable probes: Static Probe Points. (line 73) * disable tracepoint: Enable and Disable Tracepoints. (line 9) * disable type-printer: Symbols. (line 432) * disable-completion: Readline Init File Syntax. (line 113) * disassemble: Machine Code. (line 44) * DisassembleInfo.__init__: Disassembly In Python. (line 46) * DisassembleInfo.address: Disassembly In Python. (line 23) * DisassembleInfo.address_part: Disassembly In Python. (line 117) * DisassembleInfo.architecture: Disassembly In Python. (line 27) * DisassembleInfo.is_valid: Disassembly In Python. (line 37) * DisassembleInfo.progspace: Disassembly In Python. (line 32) * DisassembleInfo.read_memory: Disassembly In Python. (line 59) * DisassembleInfo.text_part: Disassembly In Python. (line 107) * Disassembler.__call__: Disassembly In Python. (line 132) * Disassembler.__init__: Disassembly In Python. (line 128) * DisassemblerAddressPart.address: Disassembly In Python. (line 310) * DisassemblerPart.string: Disassembly In Python. (line 258) * DisassemblerResult.__init__: Disassembly In Python. (line 185) * DisassemblerResult.length: Disassembly In Python. (line 209) * DisassemblerResult.parts: Disassembly In Python. (line 226) * DisassemblerResult.string: Disassembly In Python. (line 213) * DisassemblerTextPart.style: Disassembly In Python. (line 274) * disconnect: Connecting. (line 272) * display: Auto Display. (line 23) * do (down): Selection. (line 74) * do-lowercase-version (M-A, M-B, M-X, ...): Miscellaneous Commands. (line 14) * document: Define. (line 63) * dont-repeat: Commands In Guile. (line 67) * dont-repeat <1>: Define. (line 118) * down: Selection. (line 74) * Down: TUI Keys. (line 70) * down-silently: Selection. (line 106) * downcase-word (M-l): Commands For Text. (line 65) * dprintf: Dynamic Printf. (line 26) * dprintf-style agent: Dynamic Printf. (line 58) * dprintf-style call: Dynamic Printf. (line 45) * dprintf-style gdb: Dynamic Printf. (line 40) * dump: Dump/Restore Files. (line 13) * dump-functions (): Miscellaneous Commands. (line 70) * dump-macros (): Miscellaneous Commands. (line 82) * dump-variables (): Miscellaneous Commands. (line 76) * e (edit): Edit. (line 6) * echo: Output. (line 12) * echo-control-characters: Readline Init File Syntax. (line 118) * edit: Edit. (line 6) * editing-mode: Readline Init File Syntax. (line 123) * else: Command Files. (line 74) * emacs-editing-mode (C-e): Miscellaneous Commands. (line 88) * emacs-mode-string: Readline Init File Syntax. (line 129) * enable: Disabling. (line 44) * enable display: Auto Display. (line 65) * enable frame-filter: Frame Filter Management. (line 26) * enable mem: Memory Region Attributes. (line 42) * enable pretty-printer: Pretty-Printer Commands. (line 25) * enable probes: Static Probe Points. (line 60) * enable tracepoint: Enable and Disable Tracepoints. (line 19) * enable type-printer: Symbols. (line 432) * enable-bracketed-paste: Readline Init File Syntax. (line 139) * enable-keypad: Readline Init File Syntax. (line 147) * enabled: Xmethod API. (line 18) * enabled of type_printer: Type Printing API. (line 13) * end (breakpoint commands): Break Commands. (line 11) * end (if/else/while commands): Command Files. (line 103) * end (user-defined commands): Define. (line 63) * end-kbd-macro (C-x )): Keyboard Macros. (line 9) * end-of-file (usually C-d): Commands For Text. (line 6) * end-of-history (M->): Commands For History. (line 22) * end-of-iteration: Iterators In Guile. (line 70) * end-of-iteration?: Iterators In Guile. (line 73) * end-of-line (C-e): Commands For Moving. (line 9) * error annotation: Errors. (line 10) * error-begin annotation: Errors. (line 22) * error-port: I/O Ports in Guile. (line 12) * eval: Output. (line 139) * EventRegistry.connect: Events In Python. (line 19) * EventRegistry.disconnect: Events In Python. (line 23) * exception-args: Guile Exception Handling. (line 103) * exception-key: Guile Exception Handling. (line 100) * exception?: Guile Exception Handling. (line 96) * exceptionHandler: Bootstrapping. (line 37) * exchange-point-and-mark (C-x C-x): Miscellaneous Commands. (line 37) * exec-file: Files. (line 42) * exec-file-mismatch: Attach. (line 34) * exec-run-start-option: GDB/MI Support Commands. (line 105) * ExecutableChangedEvent.progspace: Events In Python. (line 292) * ExecutableChangedEvent.reload: Events In Python. (line 297) * execute: Basic Guile. (line 68) * exit [EXPRESSION]: Quitting GDB. (line 6) * exited annotation: Annotations for Running. (line 18) * ExitedEvent.exit_code: Events In Python. (line 69) * ExitedEvent.inferior: Events In Python. (line 75) * expand-tilde: Readline Init File Syntax. (line 158) * explore: Data. (line 145) * f (frame): Selection. (line 11) * f (SingleKey TUI key): TUI Single Key Mode. (line 19) * F (SingleKey TUI key): TUI Single Key Mode. (line 22) * faas: Frame Apply. (line 96) * fg (resume foreground execution): Continuing and Stepping. (line 16) * field-artificial?: Types In Guile. (line 275) * field-base-class?: Types In Guile. (line 279) * field-bitpos: Types In Guile. (line 266) * field-bitsize: Types In Guile. (line 270) * field-enumval: Types In Guile. (line 263) * field-name: Types In Guile. (line 256) * field-type: Types In Guile. (line 259) * field?: Types In Guile. (line 252) * file: Files. (line 16) * fin (finish): Continuing and Stepping. (line 109) * find: Searching Memory. (line 9) * find-pc-line: Symbol Tables In Guile. (line 71) * finish: Continuing and Stepping. (line 109) * finish&: Background Execution. (line 43) * FinishBreakpoint.__init__: Finish Breakpoints in Python. (line 14) * FinishBreakpoint.out_of_scope: Finish Breakpoints in Python. (line 21) * FinishBreakpoint.return_value: Finish Breakpoints in Python. (line 38) * flash-erase: Target Commands. (line 140) * flush_i_cache: Bootstrapping. (line 59) * flushregs: Maintenance Commands. (line 399) * fo (forward-search): Search. (line 9) * focus: TUI Commands. (line 103) * forward-backward-delete-char (): Commands For Text. (line 21) * forward-char (C-f): Commands For Moving. (line 12) * forward-search: Search. (line 9) * forward-search-history (C-s): Commands For History. (line 32) * forward-word (M-f): Commands For Moving. (line 18) * frame address: Selection. (line 30) * frame apply: Frame Apply. (line 6) * frame function: Selection. (line 48) * frame level: Selection. (line 16) * frame view: Selection. (line 53) * frame-arch: Frames In Guile. (line 35) * frame-block: Frames In Guile. (line 121) * frame-function: Frames In Guile. (line 125) * frame-name: Frames In Guile. (line 32) * frame-newer: Frames In Guile. (line 133) * frame-older: Frames In Guile. (line 130) * frame-pc: Frames In Guile. (line 118) * frame-read-register: Frames In Guile. (line 140) * frame-read-var: Frames In Guile. (line 144) * frame-sal: Frames In Guile. (line 136) * frame-select: Frames In Guile. (line 152) * frame-type: Frames In Guile. (line 39) * frame-unwind-stop-reason: Frames In Guile. (line 67) * frame-valid?: Frames In Guile. (line 26) * frame, selecting: Selection. (line 11) * frame?: Frames In Guile. (line 22) * Frame.architecture: Frames In Python. (line 53) * Frame.block: Frames In Python. (line 139) * Frame.find_sal: Frames In Python. (line 157) * Frame.function: Frames In Python. (line 145) * Frame.is_valid: Frames In Python. (line 43) * Frame.language: Frames In Python. (line 206) * Frame.level: Frames In Python. (line 202) * Frame.name: Frames In Python. (line 49) * Frame.newer: Frames In Python. (line 153) * Frame.older: Frames In Python. (line 149) * Frame.pc: Frames In Python. (line 136) * Frame.read_register: Frames In Python. (line 161) * Frame.read_var: Frames In Python. (line 181) * Frame.select: Frames In Python. (line 189) * Frame.static_link: Frames In Python. (line 193) * Frame.type: Frames In Python. (line 57) * Frame.unwind_stop_reason: Frames In Python. (line 84) * FrameDecorator.address: Frame Decorator API. (line 60) * FrameDecorator.elided: Frame Decorator API. (line 29) * FrameDecorator.filename: Frame Decorator API. (line 70) * FrameDecorator.frame_args: Frame Decorator API. (line 91) * FrameDecorator.frame_locals: Frame Decorator API. (line 143) * FrameDecorator.function: Frame Decorator API. (line 49) * FrameDecorator.inferior_frame: Frame Decorator API. (line 176) * FrameDecorator.line: Frame Decorator API. (line 81) * FrameFilter.enabled: Frame Filter API. (line 122) * FrameFilter.filter: Frame Filter API. (line 75) * FrameFilter.name: Frame Filter API. (line 115) * FrameFilter.priority: Frame Filter API. (line 131) * frames-invalid annotation: Invalidation. (line 9) * FreeObjFileEvent.objfile: Events In Python. (line 147) * FreeProgspaceEvent.progspace: Events In Python. (line 333) * frozen-varobjs: GDB/MI Support Commands. (line 75) * ftrace: Create and Delete Tracepoints. (line 50) * Function: Functions In Python. (line 6) * Function.__init__: Functions In Python. (line 10) * Function.invoke: Functions In Python. (line 19) * gcore: Core File Generation. (line 17) * gdb_init_reader: Writing JIT Debug Info Readers. (line 20) * gdb-object-kind: GDB Scheme Data Types. (line 10) * gdb-version: Guile Configuration. (line 17) * gdb:error: Guile Exception Handling. (line 69) * gdb:invalid-object: Guile Exception Handling. (line 72) * gdb:memory-error: Guile Exception Handling. (line 80) * gdb:pp-type-error: Guile Exception Handling. (line 84) * gdb.add_history: Basic Python. (line 128) * gdb.architecture_names: Basic Python. (line 269) * gdb.Block: Blocks In Python. (line 6) * gdb.block_for_pc: Blocks In Python. (line 64) * gdb.block_signals: Threading in GDB. (line 10) * gdb.BP_ACCESS_WATCHPOINT: Breakpoints In Python. (line 77) * gdb.BP_BREAKPOINT: Breakpoints In Python. (line 62) * gdb.BP_CATCHPOINT: Breakpoints In Python. (line 80) * gdb.BP_HARDWARE_BREAKPOINT: Breakpoints In Python. (line 65) * gdb.BP_HARDWARE_WATCHPOINT: Breakpoints In Python. (line 71) * gdb.BP_READ_WATCHPOINT: Breakpoints In Python. (line 74) * gdb.BP_WATCHPOINT: Breakpoints In Python. (line 68) * gdb.Breakpoint: Breakpoints In Python. (line 6) * gdb.breakpoints: Basic Python. (line 62) * gdb.COMMAND_BREAKPOINTS: CLI Commands In Python. (line 144) * gdb.COMMAND_DATA: CLI Commands In Python. (line 115) * gdb.COMMAND_FILES: CLI Commands In Python. (line 126) * gdb.COMMAND_MAINTENANCE: CLI Commands In Python. (line 173) * gdb.COMMAND_NONE: CLI Commands In Python. (line 105) * gdb.COMMAND_OBSCURE: CLI Commands In Python. (line 167) * gdb.COMMAND_RUNNING: CLI Commands In Python. (line 109) * gdb.COMMAND_STACK: CLI Commands In Python. (line 120) * gdb.COMMAND_STATUS: CLI Commands In Python. (line 138) * gdb.COMMAND_SUPPORT: CLI Commands In Python. (line 131) * gdb.COMMAND_TRACEPOINTS: CLI Commands In Python. (line 150) * gdb.COMMAND_TUI: CLI Commands In Python. (line 156) * gdb.COMMAND_USER: CLI Commands In Python. (line 161) * gdb.COMPLETE_COMMAND: CLI Commands In Python. (line 194) * gdb.COMPLETE_EXPRESSION: CLI Commands In Python. (line 202) * gdb.COMPLETE_FILENAME: CLI Commands In Python. (line 187) * gdb.COMPLETE_LOCATION: CLI Commands In Python. (line 190) * gdb.COMPLETE_NONE: CLI Commands In Python. (line 184) * gdb.COMPLETE_SYMBOL: CLI Commands In Python. (line 198) * gdb.connections: Basic Python. (line 276) * gdb.convenience_variable: Basic Python. (line 144) * gdb.current_language: Basic Python. (line 325) * gdb.current_objfile: Objfiles In Python. (line 15) * gdb.current_progspace: Progspaces In Python. (line 14) * gdb.current_recording: Recordings In Python. (line 21) * gdb.decode_line: Basic Python. (line 243) * gdb.default_visualizer: Pretty Printing API. (line 127) * gdb.disassembler.DisassembleInfo: Disassembly In Python. (line 10) * gdb.disassembler.Disassembler: Disassembly In Python. (line 124) * gdb.disassembler.DisassemblerAddressPart: Disassembly In Python. (line 280) * gdb.disassembler.DisassemblerPart: Disassembly In Python. (line 243) * gdb.disassembler.DisassemblerResult: Disassembly In Python. (line 172) * gdb.disassembler.DisassemblerTextPart: Disassembly In Python. (line 264) * gdb.disassembler.STYLE_ADDRESS: Disassembly In Python. (line 376) * gdb.disassembler.STYLE_ADDRESS_OFFSET: Disassembly In Python. (line 388) * gdb.disassembler.STYLE_ASSEMBLER_DIRECTIVE: Disassembly In Python. (line 354) * gdb.disassembler.STYLE_COMMENT_START: Disassembly In Python. (line 434) * gdb.disassembler.STYLE_IMMEDIATE: Disassembly In Python. (line 405) * gdb.disassembler.STYLE_MNEMONIC: Disassembly In Python. (line 328) * gdb.disassembler.STYLE_REGISTER: Disassembly In Python. (line 369) * gdb.disassembler.STYLE_SUB_MNEMONIC: Disassembly In Python. (line 336) * gdb.disassembler.STYLE_SYMBOL: Disassembly In Python. (line 415) * gdb.disassembler.STYLE_TEXT: Disassembly In Python. (line 322) * gdb.error: Exception Handling. (line 22) * gdb.execute: Basic Python. (line 43) * gdb.execute_mi: GDB/MI Commands In Python. (line 136) * gdb.find_pc_line: Basic Python. (line 175) * gdb.FinishBreakpoint: Finish Breakpoints in Python. (line 6) * gdb.flush: Basic Python. (line 202) * gdb.format_address: Basic Python. (line 281) * gdb.frame_stop_reason_string: Frames In Python. (line 29) * gdb.FrameDecorator: Frame Decorator API. (line 25) * gdb.Function: Functions In Python. (line 6) * gdb.GdbError: Exception Handling. (line 48) * gdb.history: Basic Python. (line 115) * gdb.history_count: Basic Python. (line 140) * gdb.host_charset: Basic Python. (line 232) * gdb.Inferior: Inferiors In Python. (line 6) * gdb.InferiorCallPostEvent: Events In Python. (line 177) * gdb.InferiorCallPreEvent: Events In Python. (line 167) * gdb.inferiors: Inferiors In Python. (line 14) * gdb.InferiorThread: Threads In Python. (line 6) * gdb.interrupt: Threading in GDB. (line 26) * gdb.invalidate_cached_frames: Frames In Python. (line 34) * gdb.LazyString: Lazy Strings In Python. (line 6) * gdb.LineTable: Line Tables In Python. (line 6) * gdb.lookup_global_symbol: Symbols In Python. (line 33) * gdb.lookup_objfile: Objfiles In Python. (line 28) * gdb.lookup_static_symbol: Symbols In Python. (line 45) * gdb.lookup_static_symbols: Symbols In Python. (line 71) * gdb.lookup_symbol: Symbols In Python. (line 13) * gdb.lookup_type: Types In Python. (line 11) * gdb.MemoryError: Exception Handling. (line 30) * gdb.missing_debug.MissingDebugHandler: Missing Debug Info In Python. (line 36) * gdb.missing_debug.register_handler: Missing Debug Info In Python. (line 105) * gdb.newest_frame: Frames In Python. (line 26) * gdb.notify_mi: GDB/MI Notifications In Python. (line 9) * gdb.Objfile: Objfiles In Python. (line 6) * gdb.objfiles: Objfiles In Python. (line 21) * gdb.PARAM_AUTO_BOOLEAN: Parameters In Python. (line 140) * gdb.PARAM_BOOLEAN: Parameters In Python. (line 136) * gdb.PARAM_ENUM: Parameters In Python. (line 190) * gdb.PARAM_FILENAME: Parameters In Python. (line 170) * gdb.PARAM_INTEGER: Parameters In Python. (line 151) * gdb.PARAM_OPTIONAL_FILENAME: Parameters In Python. (line 167) * gdb.PARAM_STRING: Parameters In Python. (line 157) * gdb.PARAM_STRING_NOESCAPE: Parameters In Python. (line 163) * gdb.PARAM_UINTEGER: Parameters In Python. (line 145) * gdb.PARAM_ZINTEGER: Parameters In Python. (line 174) * gdb.PARAM_ZUINTEGER: Parameters In Python. (line 178) * gdb.PARAM_ZUINTEGER_UNLIMITED: Parameters In Python. (line 182) * gdb.Parameter: Parameters In Python. (line 6) * gdb.parameter: Basic Python. (line 85) * gdb.parse_and_eval: Basic Python. (line 160) * gdb.post_event: Threading in GDB. (line 34) * gdb.pretty_printers: Selecting Pretty-Printers. (line 12) * gdb.print_options: Pretty Printing API. (line 137) * gdb.Progspace: Progspaces In Python. (line 6) * gdb.progspaces: Progspaces In Python. (line 20) * gdb.prompt_hook: Basic Python. (line 255) * gdb.PYTHONDIR: Basic Python. (line 40) * gdb.rbreak: Basic Python. (line 69) * gdb.register_window_type: TUI Windows In Python. (line 8) * gdb.selected_frame: Frames In Python. (line 22) * gdb.selected_inferior: Inferiors In Python. (line 17) * gdb.selected_thread: Threads In Python. (line 13) * gdb.set_convenience_variable: Basic Python. (line 151) * gdb.set_parameter: Basic Python. (line 96) * gdb.solib_name: Basic Python. (line 237) * gdb.start_recording: Recordings In Python. (line 9) * gdb.STDERR: Basic Python. (line 192) * gdb.STDERR <1>: Basic Python. (line 212) * gdb.STDLOG: Basic Python. (line 195) * gdb.STDLOG <1>: Basic Python. (line 215) * gdb.STDOUT: Basic Python. (line 189) * gdb.STDOUT <1>: Basic Python. (line 209) * gdb.stop_recording: Recordings In Python. (line 25) * gdb.string_to_argv: CLI Commands In Python. (line 63) * gdb.Symbol: Symbols In Python. (line 6) * gdb.SYMBOL_COMMON_BLOCK_DOMAIN: Symbols In Python. (line 193) * gdb.SYMBOL_FUNCTION_DOMAIN: Symbols In Python. (line 170) * gdb.SYMBOL_LABEL_DOMAIN: Symbols In Python. (line 187) * gdb.SYMBOL_LOC_ARG: Symbols In Python. (line 224) * gdb.SYMBOL_LOC_BLOCK: Symbols In Python. (line 248) * gdb.SYMBOL_LOC_COMMON_BLOCK: Symbols In Python. (line 265) * gdb.SYMBOL_LOC_COMPUTED: Symbols In Python. (line 262) * gdb.SYMBOL_LOC_CONST: Symbols In Python. (line 215) * gdb.SYMBOL_LOC_CONST_BYTES: Symbols In Python. (line 251) * gdb.SYMBOL_LOC_LABEL: Symbols In Python. (line 245) * gdb.SYMBOL_LOC_LOCAL: Symbols In Python. (line 238) * gdb.SYMBOL_LOC_OPTIMIZED_OUT: Symbols In Python. (line 259) * gdb.SYMBOL_LOC_REF_ARG: Symbols In Python. (line 228) * gdb.SYMBOL_LOC_REGISTER: Symbols In Python. (line 221) * gdb.SYMBOL_LOC_REGPARM_ADDR: Symbols In Python. (line 233) * gdb.SYMBOL_LOC_STATIC: Symbols In Python. (line 218) * gdb.SYMBOL_LOC_TYPEDEF: Symbols In Python. (line 241) * gdb.SYMBOL_LOC_UNDEF: Symbols In Python. (line 211) * gdb.SYMBOL_LOC_UNRESOLVED: Symbols In Python. (line 254) * gdb.SYMBOL_MODULE_DOMAIN: Symbols In Python. (line 190) * gdb.SYMBOL_STRUCT_DOMAIN: Symbols In Python. (line 179) * gdb.SYMBOL_TYPE_DOMAIN: Symbols In Python. (line 173) * gdb.SYMBOL_UNDEF_DOMAIN: Symbols In Python. (line 162) * gdb.SYMBOL_VAR_DOMAIN: Symbols In Python. (line 167) * gdb.Symtab: Symbol Tables In Python. (line 6) * gdb.Symtab_and_line: Symbol Tables In Python. (line 6) * gdb.target_charset: Basic Python. (line 221) * gdb.target_wide_charset: Basic Python. (line 226) * gdb.Thread: Threading in GDB. (line 20) * gdb.Type: Types In Python. (line 6) * gdb.TYPE_CODE_ARRAY: Types In Python. (line 266) * gdb.TYPE_CODE_BITSTRING: Types In Python. (line 304) * gdb.TYPE_CODE_BOOL: Types In Python. (line 328) * gdb.TYPE_CODE_CHAR: Types In Python. (line 325) * gdb.TYPE_CODE_COMPLEX: Types In Python. (line 331) * gdb.TYPE_CODE_DECFLOAT: Types In Python. (line 340) * gdb.TYPE_CODE_ENUM: Types In Python. (line 275) * gdb.TYPE_CODE_ERROR: Types In Python. (line 307) * gdb.TYPE_CODE_FIXED_POINT: Types In Python. (line 351) * gdb.TYPE_CODE_FIXED_POINT <1>: Types In Guile. (line 238) * gdb.TYPE_CODE_FLAGS: Types In Python. (line 278) * gdb.TYPE_CODE_FLT: Types In Python. (line 287) * gdb.TYPE_CODE_FUNC: Types In Python. (line 281) * gdb.TYPE_CODE_INT: Types In Python. (line 284) * gdb.TYPE_CODE_INTERNAL_FUNCTION: Types In Python. (line 343) * gdb.TYPE_CODE_MEMBERPTR: Types In Python. (line 316) * gdb.TYPE_CODE_METHOD: Types In Python. (line 310) * gdb.TYPE_CODE_METHODPTR: Types In Python. (line 313) * gdb.TYPE_CODE_NAMESPACE: Types In Python. (line 337) * gdb.TYPE_CODE_NAMESPACE <1>: Types In Python. (line 354) * gdb.TYPE_CODE_NAMESPACE <2>: Types In Guile. (line 241) * gdb.TYPE_CODE_PTR: Types In Python. (line 263) * gdb.TYPE_CODE_RANGE: Types In Python. (line 296) * gdb.TYPE_CODE_REF: Types In Python. (line 319) * gdb.TYPE_CODE_RVALUE_REF: Types In Python. (line 322) * gdb.TYPE_CODE_SET: Types In Python. (line 293) * gdb.TYPE_CODE_STRING: Types In Python. (line 299) * gdb.TYPE_CODE_STRUCT: Types In Python. (line 269) * gdb.TYPE_CODE_TYPEDEF: Types In Python. (line 334) * gdb.TYPE_CODE_UNION: Types In Python. (line 272) * gdb.TYPE_CODE_VOID: Types In Python. (line 290) * gdb.TYPE_CODE_XMETHOD: Types In Python. (line 347) * gdb.TYPE_CODE_XMETHOD <1>: Types In Guile. (line 234) * gdb.unwinder.enabled: Unwinding Frames in Python. (line 178) * gdb.unwinder.FrameId: Unwinding Frames in Python. (line 183) * gdb.unwinder.FrameId.__init__(sp,: Unwinding Frames in Python. (line 192) * gdb.unwinder.name: Unwinding Frames in Python. (line 174) * gdb.unwinder.pc: Unwinding Frames in Python. (line 204) * gdb.unwinder.register_unwinder: Unwinding Frames in Python. (line 220) * gdb.unwinder.sp: Unwinding Frames in Python. (line 201) * gdb.unwinder.special: Unwinding Frames in Python. (line 207) * gdb.unwinder.Unwinder: Unwinding Frames in Python. (line 164) * gdb.unwinder.Unwinder.__init__(name): Unwinding Frames in Python. (line 170) * gdb.UnwindInfo.add_saved_register: Unwinding Frames in Python. (line 152) * gdb.with_parameter: Basic Python. (line 101) * gdb.WP_ACCESS: Breakpoints In Python. (line 95) * gdb.WP_READ: Breakpoints In Python. (line 89) * gdb.WP_WRITE: Breakpoints In Python. (line 92) * gdb.write: Basic Python. (line 184) * GdbExitingEvent.exit_code: Events In Python. (line 271) * gdbserver: Server. (line 6) * generate-core-file: Core File Generation. (line 17) * get-basic-type: Guile Types Module. (line 13) * getDebugChar: Bootstrapping. (line 13) * gnu_debuglink_crc32: Separate Debug Files. (line 169) * gr: Guile Commands. (line 8) * gu: Guile Commands. (line 15) * guile: Guile Commands. (line 15) * guile-data-directory: Guile Configuration. (line 13) * guile-repl: Guile Commands. (line 8) * h (help): Help. (line 9) * handle: Signals. (line 49) * handle_exception: Stub Contents. (line 14) * hbreak: Set Breaks. (line 172) * help: Help. (line 6) * help function: Convenience Funs. (line 280) * help target: Target Commands. (line 19) * help user-defined: Define. (line 123) * history-append!: Basic Guile. (line 105) * history-preserve-point: Readline Init File Syntax. (line 162) * history-ref: Basic Guile. (line 87) * history-search-backward (): Commands For History. (line 56) * history-search-forward (): Commands For History. (line 50) * history-size: Readline Init File Syntax. (line 168) * history-substring-search-backward (): Commands For History. (line 68) * history-substring-search-forward (): Commands For History. (line 62) * hook: Hooks. (line 6) * hookpost: Hooks. (line 11) * horizontal-scroll-mode: Readline Init File Syntax. (line 177) * host-config: Guile Configuration. (line 20) * i (info): Help. (line 137) * i (SingleKey TUI key): TUI Single Key Mode. (line 49) * I (SingleKey TUI key): TUI Single Key Mode. (line 52) * if: Command Files. (line 74) * ignore: Conditions. (line 96) * inferior: Inferiors Connections and Programs. (line 64) * inferior INFNO: Inferiors Connections and Programs. (line 102) * Inferior.architecture: Inferiors In Python. (line 81) * Inferior.arguments: Inferiors In Python. (line 54) * Inferior.clear_env: Inferiors In Python. (line 124) * Inferior.connection: Inferiors In Python. (line 27) * Inferior.connection_num: Inferiors In Python. (line 31) * Inferior.is_valid: Inferiors In Python. (line 69) * Inferior.main_name: Inferiors In Python. (line 46) * Inferior.num: Inferiors In Python. (line 22) * Inferior.pid: Inferiors In Python. (line 38) * Inferior.progspace: Inferiors In Python. (line 51) * Inferior.read_memory: Inferiors In Python. (line 88) * Inferior.search_memory: Inferiors In Python. (line 101) * Inferior.set_env: Inferiors In Python. (line 128) * Inferior.thread_from_handle: Inferiors In Python. (line 110) * Inferior.thread_from_thread_handle: Inferiors In Python. (line 110) * Inferior.threads: Inferiors In Python. (line 76) * Inferior.unset_env: Inferiors In Python. (line 132) * Inferior.was_attached: Inferiors In Python. (line 42) * Inferior.write_memory: Inferiors In Python. (line 94) * InferiorCallPostEvent.address: Events In Python. (line 184) * InferiorCallPostEvent.ptid: Events In Python. (line 181) * InferiorCallPreEvent.address: Events In Python. (line 174) * InferiorCallPreEvent.ptid: Events In Python. (line 171) * InferiorDeletedEvent.inferior: Events In Python. (line 246) * InferiorThread.details: Threads In Python. (line 58) * InferiorThread.global_num: Threads In Python. (line 35) * InferiorThread.handle: Threads In Python. (line 96) * InferiorThread.inferior: Threads In Python. (line 54) * InferiorThread.is_exited: Threads In Python. (line 93) * InferiorThread.is_running: Threads In Python. (line 90) * InferiorThread.is_stopped: Threads In Python. (line 87) * InferiorThread.is_valid: Threads In Python. (line 76) * InferiorThread.name: Threads In Python. (line 22) * InferiorThread.num: Threads In Python. (line 32) * InferiorThread.ptid: Threads In Python. (line 40) * InferiorThread.ptid_string: Threads In Python. (line 48) * InferiorThread.switch: Threads In Python. (line 83) * info: Help. (line 137) * info address: Symbols. (line 98) * info all-registers: Registers. (line 15) * info args: Frame Info. (line 43) * info auto-load: Auto-loading. (line 52) * info auto-load gdb-scripts: Auto-loading sequences. (line 21) * info auto-load guile-scripts: Guile Auto-loading. (line 23) * info auto-load libthread-db: libthread_db.so.1 file. (line 29) * info auto-load local-gdbinit: Init File in the Current Directory. (line 22) * info auto-load python-scripts: Python Auto-loading. (line 23) * info auxv: OS Information. (line 20) * info breakpoints: Set Breaks. (line 244) * info checkpoints: Checkpoint/Restart. (line 31) * info classes: Symbols. (line 609) * info common: Special Fortran Commands. (line 9) * info connections [ ID... ]: Inferiors Connections and Programs. (line 75) * info copying: Help. (line 174) * info dcache: Caching Target Data. (line 46) * info display: Auto Display. (line 78) * info dll: Files. (line 361) * info dos: DJGPP Native. (line 15) * info exceptions: Ada Exceptions. (line 8) * info extensions: Show. (line 34) * info f (info frame): Frame Info. (line 17) * info files: Files. (line 226) * info float: Floating Point Hardware. (line 9) * info frame: Frame Info. (line 17) * info frame-filter: Frame Filter Management. (line 12) * info frame, show the source language: Show. (line 15) * info functions: Symbols. (line 501) * info handle: Signals. (line 33) * info inferiors [ ID... ]: Inferiors Connections and Programs. (line 35) * info io_registers, AVR: AVR. (line 10) * info line: Machine Code. (line 14) * info line, and Objective-C: Method Names in Commands. (line 9) * info locals: Frame Info. (line 67) * info macro: Macros. (line 47) * info macros: Macros. (line 54) * info main: Symbols. (line 604) * info mem: Memory Region Attributes. (line 45) * info meminfo: Process Information. (line 131) * info module: Symbols. (line 589) * info modules: Symbols. (line 581) * info os: OS Information. (line 37) * info os cpus: OS Information. (line 43) * info os files: OS Information. (line 51) * info os modules: OS Information. (line 57) * info os msg: OS Information. (line 64) * info os processes: OS Information. (line 75) * info os procgroups: OS Information. (line 84) * info os semaphores: OS Information. (line 94) * info os shm: OS Information. (line 102) * info os sockets: OS Information. (line 112) * info os threads: OS Information. (line 119) * info pidlist: Process Information. (line 127) * info pretty-printer: Pretty-Printer Commands. (line 6) * info probes: Static Probe Points. (line 32) * info proc: Process Information. (line 25) * info program: Stopping. (line 18) * info record: Process Record and Replay. (line 323) * info registers: Registers. (line 11) * info scope: Symbols. (line 436) * info selectors: Symbols. (line 615) * info serial: DJGPP Native. (line 139) * info set: Help. (line 157) * info share: Files. (line 355) * info sharedlibrary: Files. (line 355) * info signals: Signals. (line 33) * info skip: Skipping Over Functions and Files. (line 113) * info source: Symbols. (line 456) * info source, show the source language: Show. (line 21) * info sources: Symbols. (line 472) * info sources <1>: GDB/MI File Commands. (line 93) * info stack: Backtrace. (line 94) * info static-tracepoint-markers: Listing Static Tracepoint Markers. (line 6) * info symbol: Symbols. (line 108) * info target: Files. (line 226) * info task TASKNO: Ada Tasks. (line 102) * info tasks: Ada Tasks. (line 9) * info terminal: Input/Output. (line 12) * info threads: Threads. (line 122) * info tp [N...]: Listing Tracepoints. (line 6) * info tracepoints [N...]: Listing Tracepoints. (line 6) * info tvariables: Trace State Variables. (line 37) * info type-printers: Symbols. (line 424) * info types: Symbols. (line 399) * info variables: Symbols. (line 546) * info vector: Vector Unit. (line 9) * info w32: Cygwin Native. (line 19) * info warranty: Help. (line 178) * info watchpoints [LIST...]: Set Watchpoints. (line 90) * info win: TUI Commands. (line 26) * info-gdb-mi-command: GDB/MI Support Commands. (line 99) * init-if-undefined: Convenience Vars. (line 42) * input-meta: Readline Init File Syntax. (line 186) * input-port: I/O Ports in Guile. (line 6) * insert-comment (M-#): Miscellaneous Commands. (line 61) * insert-completions (M-*): Commands For Completion. (line 18) * inspect: Data. (line 6) * instantiate on type_printer: Type Printing API. (line 22) * Instruction.data: Recordings In Python. (line 69) * Instruction.decoded: Recordings In Python. (line 72) * Instruction.pc: Recordings In Python. (line 66) * Instruction.size: Recordings In Python. (line 75) * interpreter-exec: Interpreters. (line 44) * interrupt: Background Execution. (line 59) * isearch-terminators: Readline Init File Syntax. (line 194) * iterator->list: Iterators In Guile. (line 83) * iterator-filter: Iterators In Guile. (line 94) * iterator-for-each: Iterators In Guile. (line 90) * iterator-map: Iterators In Guile. (line 86) * iterator-next!: Iterators In Guile. (line 63) * iterator-object: Iterators In Guile. (line 53) * iterator-progress: Iterators In Guile. (line 57) * iterator-until: Iterators In Guile. (line 98) * iterator?: Iterators In Guile. (line 49) * j (jump): Jumping. (line 10) * jit-reader-load: Using JIT Debug Info Readers. (line 6) * jit-reader-unload: Using JIT Debug Info Readers. (line 6) * jump: Jumping. (line 10) * jump, and Objective-C: Method Names in Commands. (line 9) * KeyboardInterrupt: Exception Handling. (line 34) * keymap: Readline Init File Syntax. (line 201) * kill: Kill Process. (line 6) * kill inferiors INFNO...: Inferiors Connections and Programs. (line 174) * kill-line (C-k): Commands For Killing. (line 6) * kill-region (): Commands For Killing. (line 52) * kill-whole-line (): Commands For Killing. (line 19) * kill-word (M-d): Commands For Killing. (line 23) * kvm: BSD libkvm Interface. (line 24) * l (list): List. (line 6) * language-option: GDB/MI Support Commands. (line 96) * layout: TUI Commands. (line 74) * lazy-string->value: Lazy Strings In Guile. (line 46) * lazy-string-address: Lazy Strings In Guile. (line 26) * lazy-string-encoding: Lazy Strings In Guile. (line 34) * lazy-string-length: Lazy Strings In Guile. (line 29) * lazy-string-type: Lazy Strings In Guile. (line 40) * lazy-string?: Lazy Strings In Guile. (line 22) * LazyString.address: Lazy Strings In Python. (line 26) * LazyString.encoding: Lazy Strings In Python. (line 36) * LazyString.length: Lazy Strings In Python. (line 30) * LazyString.type: Lazy Strings In Python. (line 43) * LazyString.value: Lazy Strings In Python. (line 20) * Left: TUI Keys. (line 73) * LineTable.has_line: Line Tables In Python. (line 57) * LineTable.line: Line Tables In Python. (line 51) * LineTable.source_lines: Line Tables In Python. (line 62) * LineTableEntry.line: Line Tables In Python. (line 16) * LineTableEntry.pc: Line Tables In Python. (line 21) * list: List. (line 6) * list, and Objective-C: Method Names in Commands. (line 9) * load FILENAME OFFSET: Target Commands. (line 114) * lookup-block: Blocks In Guile. (line 117) * lookup-global-symbol: Symbols In Guile. (line 99) * lookup-symbol: Symbols In Guile. (line 79) * lookup-type: Types In Guile. (line 15) * loop_break: Command Files. (line 93) * loop_continue: Command Files. (line 97) * macro define: Macros. (line 60) * macro exp1: Macros. (line 36) * macro expand: Macros. (line 29) * macro list: Macros. (line 81) * macro undef: Macros. (line 75) * maint ada set ignore-descriptive-types: Ada Glitches. (line 73) * maint ada show ignore-descriptive-types: Ada Glitches. (line 77) * maint agent: Maintenance Commands. (line 11) * maint agent-eval: Maintenance Commands. (line 11) * maint agent-printf: Maintenance Commands. (line 27) * maint btrace clear: Maintenance Commands. (line 100) * maint btrace clear-packet-history: Maintenance Commands. (line 95) * maint btrace packet-history: Maintenance Commands. (line 66) * maint check libthread-db: Maintenance Commands. (line 321) * maint check xml-descriptions: Maintenance Commands. (line 317) * maint check-psymtabs: Maintenance Commands. (line 178) * maint check-symtabs: Maintenance Commands. (line 183) * maint cplus first_component: Maintenance Commands. (line 198) * maint cplus namespace: Maintenance Commands. (line 201) * maint demangler-warning: Maintenance Commands. (line 217) * maint deprecate: Maintenance Commands. (line 204) * maint dump-me: Maintenance Commands. (line 212) * maint expand-symtabs: Maintenance Commands. (line 186) * maint flush dcache: Caching Target Data. (line 71) * maint flush register-cache: Maintenance Commands. (line 399) * maint flush source-cache: Maintenance Commands. (line 406) * maint flush symbol-cache: Symbols. (line 786) * maint flush-symbol-cache: Symbols. (line 786) * maint ignore-probes: Maintenance Commands. (line 822) * maint info bdccsr, S12Z: S12Z. (line 10) * maint info bfds: File Caching. (line 10) * maint info breakpoints: Maintenance Commands. (line 33) * maint info btrace: Maintenance Commands. (line 63) * maint info frame-unwinders: Maintenance Commands. (line 567) * maint info jit: Maintenance Commands. (line 113) * maint info line-table: Symbols. (line 731) * maint info linux-lwps: Maintenance Commands. (line 123) * maint info program-spaces: Inferiors Connections and Programs. (line 209) * maint info psymtabs: Symbols. (line 684) * maint info python-disassemblers: Maintenance Commands. (line 117) * maint info screen: Maintenance Commands. (line 746) * maint info sections: Files. (line 235) * maint info selftests: Maintenance Commands. (line 489) * maint info sol-threads: Threads. (line 174) * maint info symtabs: Symbols. (line 684) * maint info target-sections: Files. (line 284) * maint internal-error: Maintenance Commands. (line 217) * maint internal-warning: Maintenance Commands. (line 217) * maint packet: Connections In Python. (line 84) * maint packet <1>: Maintenance Commands. (line 281) * maint print arc arc-instruction: ARC. (line 17) * maint print architecture: Maintenance Commands. (line 290) * maint print c-tdesc: Maintenance Commands. (line 294) * maint print cooked-registers: Maintenance Commands. (line 364) * maint print core-file-backed-mappings: Maintenance Commands. (line 329) * maint print dummy-frames: Maintenance Commands. (line 335) * maint print frame-id: Maintenance Commands. (line 351) * maint print msymbols: Symbols. (line 658) * maint print objfiles: Maintenance Commands. (line 417) * maint print psymbols: Symbols. (line 658) * maint print raw-registers: Maintenance Commands. (line 364) * maint print record-instruction: Maintenance Commands. (line 471) * maint print reggroups: Maintenance Commands. (line 383) * maint print register-groups: Maintenance Commands. (line 364) * maint print registers: Maintenance Commands. (line 364) * maint print remote-registers: Maintenance Commands. (line 364) * maint print section-scripts: Maintenance Commands. (line 432) * maint print statistics: Maintenance Commands. (line 439) * maint print symbol-cache: Symbols. (line 778) * maint print symbol-cache-statistics: Symbols. (line 782) * maint print symbols: Symbols. (line 658) * maint print target-stack: Maintenance Commands. (line 452) * maint print type: Maintenance Commands. (line 464) * maint print unwind, HPPA: HPPA. (line 17) * maint print user-registers: Maintenance Commands. (line 423) * maint print xml-tdesc: Maintenance Commands. (line 309) * maint selftest: Maintenance Commands. (line 479) * maint set backtrace-on-fatal-signal: Maintenance Commands. (line 796) * maint set bfd-sharing: File Caching. (line 14) * maint set btrace pt skip-pad: Maintenance Commands. (line 108) * maint set catch-demangler-crashes: Maintenance Commands. (line 190) * maint set check-libthread-db: Maintenance Commands. (line 699) * maint set debuginfod download-sections: Maintenance Commands. (line 241) * maint set demangler-warning: Maintenance Commands. (line 249) * maint set dwarf always-disassemble: Maintenance Commands. (line 492) * maint set dwarf max-cache-age: Maintenance Commands. (line 513) * maint set dwarf synchronous: Maintenance Commands. (line 527) * maint set dwarf unwinders: Maintenance Commands. (line 544) * maint set gnu-source-highlight enabled: Maintenance Commands. (line 708) * maint set ignore-prologue-end-flag: Symbols. (line 794) * maint set internal-error: Maintenance Commands. (line 249) * maint set internal-error <1>: Maintenance Commands. (line 272) * maint set internal-warning: Maintenance Commands. (line 249) * maint set internal-warning <1>: Maintenance Commands. (line 272) * maint set libopcodes-styling enabled: Maintenance Commands. (line 725) * maint set per-command: Maintenance Commands. (line 660) * maint set profile: Maintenance Commands. (line 582) * maint set selftest verbose: Maintenance Commands. (line 485) * maint set show-all-tib: Maintenance Commands. (line 606) * maint set show-debug-regs: Maintenance Commands. (line 598) * maint set symbol-cache-size: Symbols. (line 770) * maint set target-async: Maintenance Commands. (line 612) * maint set target-non-stop MODE [on|off|auto]: Maintenance Commands. (line 620) * maint set test-settings: Maintenance Commands. (line 790) * maint set tui-left-margin-verbose: Maintenance Commands. (line 651) * maint set tui-resize-message: Maintenance Commands. (line 640) * maint set worker-threads: Maintenance Commands. (line 571) * maint show backtrace-on-fatal-signal: Maintenance Commands. (line 796) * maint show bfd-sharing: File Caching. (line 14) * maint show btrace pt skip-pad: Maintenance Commands. (line 109) * maint show catch-demangler-crashes: Maintenance Commands. (line 190) * maint show check-libthread-db: Maintenance Commands. (line 699) * maint show debuginfod download-sections: Maintenance Commands. (line 241) * maint show demangler-warning: Maintenance Commands. (line 249) * maint show dwarf always-disassemble: Maintenance Commands. (line 492) * maint show dwarf max-cache-age: Maintenance Commands. (line 513) * maint show dwarf synchronous: Maintenance Commands. (line 527) * maint show dwarf unwinders: Maintenance Commands. (line 544) * maint show gnu-source-highlight enabled: Maintenance Commands. (line 708) * maint show ignore-prologue-end-flag: Symbols. (line 801) * maint show internal-error: Maintenance Commands. (line 249) * maint show internal-error <1>: Maintenance Commands. (line 272) * maint show internal-warning: Maintenance Commands. (line 249) * maint show internal-warning <1>: Maintenance Commands. (line 272) * maint show libopcodes-styling enabled: Maintenance Commands. (line 725) * maint show per-command: Maintenance Commands. (line 660) * maint show profile: Maintenance Commands. (line 582) * maint show selftest verbose: Maintenance Commands. (line 485) * maint show show-all-tib: Maintenance Commands. (line 606) * maint show show-debug-regs: Maintenance Commands. (line 598) * maint show symbol-cache-size: Symbols. (line 775) * maint show target-async: Maintenance Commands. (line 612) * maint show target-non-stop: Maintenance Commands. (line 620) * maint show test-options-completion-result: Maintenance Commands. (line 785) * maint show test-settings: Maintenance Commands. (line 790) * maint show tui-left-margin-verbose: Maintenance Commands. (line 651) * maint show tui-resize-message: Maintenance Commands. (line 640) * maint show worker-threads: Maintenance Commands. (line 571) * maint space: Maintenance Commands. (line 750) * maint test-options: Maintenance Commands. (line 771) * maint time: Maintenance Commands. (line 754) * maint translate-address: Maintenance Commands. (line 758) * maint undeprecate: Maintenance Commands. (line 204) * maint wait-for-index-cache: Maintenance Commands. (line 812) * maint with: Maintenance Commands. (line 817) * make: Shell Commands. (line 25) * make-block-symbols-iterator: Blocks In Guile. (line 105) * make-breakpoint: Breakpoints In Guile. (line 19) * make-command: Commands In Guile. (line 15) * make-enum-hashtable: Guile Types Module. (line 37) * make-exception: Guile Exception Handling. (line 91) * make-field-iterator: Types In Guile. (line 125) * make-iterator: Iterators In Guile. (line 11) * make-lazy-value: Values From Inferior In Guile. (line 339) * make-list-iterator: Iterators In Guile. (line 80) * make-parameter: Parameters In Guile. (line 22) * make-pretty-printer: Guile Pretty Printing API. (line 15) * make-pretty-printer-worker: Guile Pretty Printing API. (line 42) * make-value: Values From Inferior In Guile. (line 45) * mark-modified-lines: Readline Init File Syntax. (line 231) * mark-symlinked-directories: Readline Init File Syntax. (line 236) * match-hidden-files: Readline Init File Syntax. (line 241) * may-insert-breakpoints: Observer Mode. (line 50) * may-insert-fast-tracepoints: Observer Mode. (line 69) * may-insert-tracepoints: Observer Mode. (line 59) * may-interrupt: Observer Mode. (line 79) * may-write-memory: Observer Mode. (line 41) * may-write-registers: Observer Mode. (line 32) * mem: Memory Region Attributes. (line 22) * memory-port-range: Memory Ports in Guile. (line 33) * memory-port-read-buffer-size: Memory Ports in Guile. (line 37) * memory-port-write-buffer-size: Memory Ports in Guile. (line 52) * memory-port?: Memory Ports in Guile. (line 29) * memory-tag check: Memory Tagging. (line 45) * memory-tag print-allocation-tag: Memory Tagging. (line 39) * memory-tag print-logical-tag: Memory Tagging. (line 35) * memory-tag setatag: Memory Tagging. (line 42) * memory-tag with-logical-tag: Memory Tagging. (line 36) * MemoryChangedEvent.address: Events In Python. (line 193) * MemoryChangedEvent.length: Events In Python. (line 196) * memset: Bootstrapping. (line 69) * menu-complete (): Commands For Completion. (line 22) * menu-complete-backward (): Commands For Completion. (line 34) * menu-complete-display-prefix: Readline Init File Syntax. (line 248) * meta-flag: Readline Init File Syntax. (line 186) * methods: Xmethod API. (line 22) * MICommand.__init__: GDB/MI Commands In Python. (line 10) * MICommand.installed: GDB/MI Commands In Python. (line 70) * MICommand.invoke: GDB/MI Commands In Python. (line 22) * MICommand.name: GDB/MI Commands In Python. (line 66) * MissingDebugHandler.__call__: Missing Debug Info In Python. (line 49) * MissingDebugHandler.__init__: Missing Debug Info In Python. (line 43) * MissingDebugHandler.enabled: Missing Debug Info In Python. (line 100) * MissingDebugHandler.name: Missing Debug Info In Python. (line 96) * monitor: Connecting. (line 279) * n (next): Continuing and Stepping. (line 77) * n (SingleKey TUI key): TUI Single Key Mode. (line 25) * N (SingleKey TUI key): TUI Single Key Mode. (line 28) * name: Xmethod API. (line 15) * name of type_printer: Type Printing API. (line 18) * new-ui: Interpreters. (line 73) * newest-frame: Frames In Guile. (line 160) * NewInferiorEvent.inferior: Events In Python. (line 235) * NewObjFileEvent.new_objfile: Events In Python. (line 136) * NewProgspaceEvent.progspace: Events In Python. (line 319) * NewThreadEvent.inferior_thread: Events In Python. (line 254) * next: Continuing and Stepping. (line 77) * next-history (C-n): Commands For History. (line 16) * next-screen-line (): Commands For Moving. (line 33) * next&: Background Execution. (line 34) * nexti: Continuing and Stepping. (line 209) * nexti&: Background Execution. (line 37) * ni (nexti): Continuing and Stepping. (line 209) * non-incremental-forward-search-history (M-n): Commands For History. (line 44) * non-incremental-reverse-search-history (M-p): Commands For History. (line 38) * nosharedlibrary: Files. (line 373) * o (SingleKey TUI key): TUI Single Key Mode. (line 31) * O (SingleKey TUI key): TUI Single Key Mode. (line 34) * Objfile: Objfiles In Python. (line 6) * objfile-filename: Objfiles In Guile. (line 28) * objfile-pretty-printers: Objfiles In Guile. (line 36) * objfile-progspace: Objfiles In Guile. (line 32) * objfile-valid?: Objfiles In Guile. (line 21) * objfile?: Objfiles In Guile. (line 17) * Objfile.add_separate_debug_file: Objfiles In Python. (line 135) * Objfile.build_id: Objfiles In Python. (line 74) * Objfile.filename: Objfiles In Python. (line 49) * Objfile.frame_filters: Objfiles In Python. (line 100) * Objfile.is_file: Objfiles In Python. (line 62) * Objfile.is_valid: Objfiles In Python. (line 128) * Objfile.lookup_global_symbol: Objfiles In Python. (line 144) * Objfile.lookup_static_symbol: Objfiles In Python. (line 155) * Objfile.owner: Objfiles In Python. (line 67) * Objfile.pretty_printers: Objfiles In Python. (line 88) * Objfile.progspace: Objfiles In Python. (line 84) * Objfile.type_printers: Objfiles In Python. (line 96) * Objfile.username: Objfiles In Python. (line 56) * objfiles: Objfiles In Guile. (line 52) * observer: Observer Mode. (line 22) * open-memory: Memory Ports in Guile. (line 11) * operate-and-get-next (C-o): Commands For History. (line 95) * output: Output. (line 35) * output-meta: Readline Init File Syntax. (line 253) * output-port: I/O Ports in Guile. (line 9) * overlay: Overlay Commands. (line 17) * overload-choice annotation: Prompting. (line 32) * overwrite-mode (): Commands For Text. (line 73) * page-completions: Readline Init File Syntax. (line 259) * PARAM_AUTO_BOOLEAN: Parameters In Python. (line 140) * PARAM_AUTO_BOOLEAN <1>: Parameters In Guile. (line 121) * PARAM_BOOLEAN: Parameters In Python. (line 136) * PARAM_BOOLEAN <1>: Parameters In Guile. (line 117) * PARAM_ENUM: Parameters In Python. (line 190) * PARAM_ENUM <1>: Parameters In Guile. (line 159) * PARAM_FILENAME: Parameters In Python. (line 170) * PARAM_FILENAME <1>: Parameters In Guile. (line 155) * PARAM_INTEGER: Parameters In Python. (line 151) * PARAM_OPTIONAL_FILENAME: Parameters In Python. (line 167) * PARAM_OPTIONAL_FILENAME <1>: Parameters In Guile. (line 152) * PARAM_STRING: Parameters In Python. (line 157) * PARAM_STRING <1>: Parameters In Guile. (line 142) * PARAM_STRING_NOESCAPE: Parameters In Python. (line 163) * PARAM_STRING_NOESCAPE <1>: Parameters In Guile. (line 148) * PARAM_UINTEGER: Parameters In Python. (line 145) * PARAM_UINTEGER <1>: Parameters In Guile. (line 126) * PARAM_ZINTEGER: Parameters In Python. (line 174) * PARAM_ZINTEGER <1>: Parameters In Guile. (line 131) * PARAM_ZUINTEGER: Parameters In Python. (line 178) * PARAM_ZUINTEGER <1>: Parameters In Guile. (line 134) * PARAM_ZUINTEGER_UNLIMITED: Parameters In Python. (line 182) * PARAM_ZUINTEGER_UNLIMITED <1>: Parameters In Guile. (line 137) * Parameter: Parameters In Python. (line 6) * Parameter <1>: Parameters In Guile. (line 6) * parameter-value: Parameters In Guile. (line 104) * parameter?: Parameters In Guile. (line 100) * Parameter.__init__: Parameters In Python. (line 18) * Parameter.get_set_string: Parameters In Python. (line 96) * Parameter.get_show_string: Parameters In Python. (line 126) * Parameter.set_doc: Parameters In Python. (line 56) * Parameter.show_doc: Parameters In Python. (line 72) * Parameter.value: Parameters In Python. (line 88) * parse-and-eval: Basic Guile. (line 113) * passcount: Tracepoint Passcounts. (line 6) * path: Environment. (line 14) * pending-breakpoints: GDB/MI Support Commands. (line 79) * PendingFrame.architecture: Unwinding Frames in Python. (line 103) * PendingFrame.block: Unwinding Frames in Python. (line 128) * PendingFrame.create_unwind_info: Unwinding Frames in Python. (line 66) * PendingFrame.find_sal: Unwinding Frames in Python. (line 138) * PendingFrame.function: Unwinding Frames in Python. (line 134) * PendingFrame.is_valid: Unwinding Frames in Python. (line 116) * PendingFrame.language: Unwinding Frames in Python. (line 142) * PendingFrame.level: Unwinding Frames in Python. (line 108) * PendingFrame.name: Unwinding Frames in Python. (line 112) * PendingFrame.pc: Unwinding Frames in Python. (line 125) * PendingFrame.read_register: Unwinding Frames in Python. (line 42) * PgDn: TUI Keys. (line 64) * PgUp: TUI Keys. (line 61) * pi: Python Commands. (line 9) * pipe: Shell Commands. (line 29) * po (print-object): The Print Command with Objective-C. (line 6) * possible-completions (M-?): Commands For Completion. (line 11) * post-commands annotation: Prompting. (line 27) * post-overload-choice annotation: Prompting. (line 32) * post-prompt annotation: Prompting. (line 24) * post-prompt-for-continue annotation: Prompting. (line 40) * post-query annotation: Prompting. (line 36) * pre-commands annotation: Prompting. (line 27) * pre-overload-choice annotation: Prompting. (line 32) * pre-prompt annotation: Prompting. (line 24) * pre-prompt-for-continue annotation: Prompting. (line 40) * pre-query annotation: Prompting. (line 36) * prefix-meta (): Miscellaneous Commands. (line 19) * prepend-pretty-printer!: Guile Printing Module. (line 13) * pretty_printer.child: Pretty Printing API. (line 116) * pretty_printer.children: Pretty Printing API. (line 24) * pretty_printer.display_hint: Pretty Printing API. (line 46) * pretty_printer.num_children: Pretty Printing API. (line 109) * pretty_printer.to_string: Pretty Printing API. (line 78) * pretty-printer-enabled?: Guile Pretty Printing API. (line 28) * pretty-printer?: Guile Pretty Printing API. (line 24) * pretty-printers: Guile Pretty Printing API. (line 35) * previous-history (C-p): Commands For History. (line 12) * previous-screen-line (): Commands For Moving. (line 26) * print: Data. (line 6) * print-last-kbd-macro (): Keyboard Macros. (line 17) * print-object: The Print Command with Objective-C. (line 6) * printf: Output. (line 46) * proc-trace-entry: Process Information. (line 123) * proc-trace-exit: Process Information. (line 123) * proc-untrace-entry: Process Information. (line 123) * proc-untrace-exit: Process Information. (line 123) * Progspace: Progspaces In Python. (line 6) * progspace-filename: Progspaces In Guile. (line 34) * progspace-objfiles: Progspaces In Guile. (line 44) * progspace-pretty-printers: Progspaces In Guile. (line 52) * progspace-valid?: Progspaces In Guile. (line 21) * progspace?: Progspaces In Guile. (line 17) * Progspace.block_for_pc: Progspaces In Python. (line 86) * Progspace.executable_filename: Progspaces In Python. (line 49) * Progspace.filename: Progspaces In Python. (line 26) * Progspace.find_pc_line: Progspaces In Python. (line 91) * Progspace.frame_filters: Progspaces In Python. (line 75) * Progspace.is_valid: Progspaces In Python. (line 98) * Progspace.missing_debug_handlers: Progspaces In Python. (line 79) * Progspace.objfile_for_address: Progspaces In Python. (line 113) * Progspace.objfiles: Progspaces In Python. (line 105) * Progspace.pretty_printers: Progspaces In Python. (line 63) * Progspace.solib_name: Progspaces In Python. (line 109) * Progspace.symbol_file: Progspaces In Python. (line 34) * Progspace.type_printers: Progspaces In Python. (line 71) * progspaces: Progspaces In Guile. (line 31) * prompt annotation: Prompting. (line 24) * prompt-for-continue annotation: Prompting. (line 40) * ptype: Symbols. (line 319) * putDebugChar: Bootstrapping. (line 19) * pwd: Working Directory. (line 40) * py: Python Commands. (line 23) * python: GDB/MI Support Commands. (line 82) * python <1>: Python Commands. (line 23) * python-interactive: Python Commands. (line 9) * q (quit): Quitting GDB. (line 6) * q (SingleKey TUI key): TUI Single Key Mode. (line 37) * query annotation: Prompting. (line 36) * queue-signal: Signaling. (line 36) * quit [EXPRESSION]: Quitting GDB. (line 6) * quit annotation: Errors. (line 6) * quoted-insert (C-q or C-v): Commands For Text. (line 26) * r (run): Starting. (line 6) * r (SingleKey TUI key): TUI Single Key Mode. (line 40) * rbreak: Set Breaks. (line 201) * rc (reverse-continue): Reverse Execution. (line 36) * re-read-init-file (C-x C-r): Miscellaneous Commands. (line 6) * readnow: Files. (line 103) * rec: Process Record and Replay. (line 43) * rec btrace: Process Record and Replay. (line 43) * rec btrace bts: Process Record and Replay. (line 43) * rec btrace pt: Process Record and Replay. (line 43) * rec bts: Process Record and Replay. (line 43) * rec del: Process Record and Replay. (line 357) * rec full: Process Record and Replay. (line 43) * rec function-call-history: Process Record and Replay. (line 426) * rec instruction-history: Process Record and Replay. (line 363) * rec pt: Process Record and Replay. (line 43) * rec s: Process Record and Replay. (line 106) * recognize on type_recognizer: Type Printing API. (line 42) * record: Process Record and Replay. (line 43) * record btrace: Process Record and Replay. (line 43) * record btrace bts: Process Record and Replay. (line 43) * record btrace pt: Process Record and Replay. (line 43) * record bts: Process Record and Replay. (line 43) * record delete: Process Record and Replay. (line 357) * record full: Process Record and Replay. (line 43) * record function-call-history: Process Record and Replay. (line 426) * record goto: Process Record and Replay. (line 129) * record instruction-history: Process Record and Replay. (line 363) * record pt: Process Record and Replay. (line 43) * record restore: Process Record and Replay. (line 150) * record save: Process Record and Replay. (line 143) * record stop: Process Record and Replay. (line 106) * Record.begin: Recordings In Python. (line 40) * Record.end: Recordings In Python. (line 44) * Record.format: Recordings In Python. (line 36) * Record.function_call_history: Recordings In Python. (line 55) * Record.goto: Recordings In Python. (line 60) * Record.instruction_history: Recordings In Python. (line 52) * Record.method: Recordings In Python. (line 32) * Record.replay_position: Recordings In Python. (line 48) * RecordFunctionSegment.instructions: Recordings In Python. (line 125) * RecordFunctionSegment.level: Recordings In Python. (line 121) * RecordFunctionSegment.next: Recordings In Python. (line 139) * RecordFunctionSegment.number: Recordings In Python. (line 112) * RecordFunctionSegment.prev: Recordings In Python. (line 135) * RecordFunctionSegment.symbol: Recordings In Python. (line 117) * RecordFunctionSegment.up: Recordings In Python. (line 129) * RecordGap.error_code: Recordings In Python. (line 103) * RecordGap.error_string: Recordings In Python. (line 107) * RecordGap.number: Recordings In Python. (line 98) * RecordInstruction.is_speculative: Recordings In Python. (line 90) * RecordInstruction.number: Recordings In Python. (line 80) * RecordInstruction.sal: Recordings In Python. (line 85) * redraw-current-line (): Commands For Moving. (line 49) * refresh: TUI Commands. (line 126) * register_disassembler: Disassembly In Python. (line 451) * register_xmethod_matcher: Xmethod API. (line 82) * register-breakpoint!: Breakpoints In Guile. (line 97) * register-command!: Commands In Guile. (line 58) * register-parameter!: Parameters In Guile. (line 95) * RegisterChangedEvent.frame: Events In Python. (line 203) * RegisterChangedEvent.regnum: Events In Python. (line 206) * RegisterDescriptor.name: Registers In Python. (line 19) * RegisterDescriptorIterator.find: Registers In Python. (line 25) * RegisterGroup.name: Registers In Python. (line 48) * remote delete: File Transfer. (line 23) * remote get: File Transfer. (line 19) * remote put: File Transfer. (line 15) * RemoteTargetConnection.send_packet: Connections In Python. (line 84) * remove-inferiors: Inferiors Connections and Programs. (line 158) * remove-symbol-file: Files. (line 186) * restart CHECKPOINT-ID: Checkpoint/Restart. (line 41) * restore: Dump/Restore Files. (line 40) * RET (repeat last command): Command Syntax. (line 21) * return: Returning. (line 6) * reverse-continue: Reverse Execution. (line 36) * reverse-finish: Reverse Execution. (line 83) * reverse-next: Reverse Execution. (line 66) * reverse-nexti: Reverse Execution. (line 75) * reverse-search: Search. (line 16) * reverse-search-history (C-r): Commands For History. (line 26) * reverse-step: Reverse Execution. (line 43) * reverse-stepi: Reverse Execution. (line 58) * revert-all-at-newline: Readline Init File Syntax. (line 269) * revert-line (M-r): Miscellaneous Commands. (line 26) * Right: TUI Keys. (line 76) * rn (reverse-next): Reverse Execution. (line 66) * rni (reverse-nexti): Reverse Execution. (line 75) * rs (step): Reverse Execution. (line 43) * rsi (reverse-stepi): Reverse Execution. (line 58) * run: Starting. (line 6) * run&: Background Execution. (line 21) * rwatch: Set Watchpoints. (line 82) * s (SingleKey TUI key): TUI Single Key Mode. (line 43) * S (SingleKey TUI key): TUI Single Key Mode. (line 46) * s (step): Continuing and Stepping. (line 45) * sal-last: Symbol Tables In Guile. (line 68) * sal-line: Symbol Tables In Guile. (line 62) * sal-pc: Symbol Tables In Guile. (line 65) * sal-symtab: Symbol Tables In Guile. (line 59) * sal-valid?: Symbol Tables In Guile. (line 53) * sal?: Symbol Tables In Guile. (line 49) * save breakpoints: Save Breakpoints. (line 9) * save gdb-index: Index Files. (line 30) * save tracepoints: save tracepoints. (line 6) * save-tracepoints: save tracepoints. (line 6) * search: Search. (line 9) * section: Files. (line 218) * select-frame: Selection. (line 98) * selected-frame: Frames In Guile. (line 156) * self: Commands In Guile. (line 100) * self-insert (a, b, A, 1, !, ...): Commands For Text. (line 33) * set: Help. (line 145) * set ada print-signatures: Overloading support for Ada. (line 31) * set ada source-charset: Ada Source Character Set. (line 11) * set ada trust-PAD-over-XVS: Ada Glitches. (line 42) * set agent off: In-Process Agent. (line 47) * set agent on: In-Process Agent. (line 38) * set always-read-ctf [on|off]: Symbols. (line 763) * set amdgpu precise-memory: AMD GPU. (line 165) * set annotate: Annotations Overview. (line 29) * set architecture: Targets. (line 21) * set args: Arguments. (line 21) * set arm: ARM. (line 9) * set auto-connect-native-target: Starting. (line 168) * set auto-load gdb-scripts: Auto-loading sequences. (line 13) * set auto-load guile-scripts: Guile Auto-loading. (line 17) * set auto-load libthread-db: libthread_db.so.1 file. (line 21) * set auto-load local-gdbinit: Init File in the Current Directory. (line 14) * set auto-load off: Auto-loading. (line 24) * set auto-load python-scripts: Python Auto-loading. (line 17) * set auto-load safe-path: Auto-loading safe path. (line 32) * set auto-load scripts-directory: objfile-gdbdotext file. (line 41) * set auto-solib-add: Files. (line 332) * set backtrace: Backtrace. (line 166) * set basenames-may-differ: Files. (line 561) * set breakpoint always-inserted: Set Breaks. (line 434) * set breakpoint auto-hw: Set Breaks. (line 414) * set breakpoint condition-evaluation: Set Breaks. (line 455) * set breakpoint pending: Set Breaks. (line 383) * set can-use-hw-watchpoints: Set Watchpoints. (line 119) * set case-sensitive: Symbols. (line 27) * set charset: Character Sets. (line 46) * set check range: Range Checking. (line 34) * set check type: Type Checking. (line 35) * set circular-trace-buffer: Starting and Stopping Trace Experiments. (line 93) * set code-cache: Caching Target Data. (line 36) * set coerce-float-to-double: ABI. (line 45) * set com1base: DJGPP Native. (line 122) * set com1irq: DJGPP Native. (line 122) * set com2base: DJGPP Native. (line 122) * set com2irq: DJGPP Native. (line 122) * set com3base: DJGPP Native. (line 122) * set com3irq: DJGPP Native. (line 122) * set com4base: DJGPP Native. (line 122) * set com4irq: DJGPP Native. (line 122) * set complaints: Messages/Warnings. (line 29) * set confirm: Messages/Warnings. (line 49) * set cp-abi: ABI. (line 57) * set cwd: Working Directory. (line 13) * set cygwin-exceptions: Cygwin Native. (line 60) * set data-directory: Data Files. (line 12) * set dcache line-size: Caching Target Data. (line 60) * set dcache size: Caching Target Data. (line 57) * set debug: Debugging Output. (line 19) * set debug aarch64: AArch64. (line 10) * set debug arc: ARC. (line 9) * set debug auto-load: Auto-loading verbose mode. (line 27) * set debug bfd-cache LEVEL: File Caching. (line 24) * set debug darwin: Darwin. (line 9) * set debug entry-values: Tail Call Frames. (line 47) * set debug hppa: HPPA. (line 10) * set debug libthread-db: Threads. (line 338) * set debug mach-o: Darwin. (line 16) * set debug mips: MIPS. (line 100) * set debug monitor: Target Commands. (line 107) * set debug nios2: Nios II. (line 10) * set debug py-breakpoint: Python Commands. (line 101) * set debug py-unwind: Python Commands. (line 106) * set debug skip: Skipping Over Functions and Files. (line 149) * set debug threads: Threads. (line 343) * set debug tui: TUI Configuration. (line 64) * set debug-file-directory: Separate Debug Files. (line 77) * set debugevents: Cygwin Native. (line 89) * set debugexceptions: Cygwin Native. (line 100) * set debugexec: Cygwin Native. (line 96) * set debuginfod enabled: Debuginfod Settings. (line 8) * set debuginfod urls: Debuginfod Settings. (line 31) * set debuginfod verbose: Debuginfod Settings. (line 41) * set debugmemory: Cygwin Native. (line 104) * set default-collect: Tracepoint Actions. (line 142) * set demangle-style: Print Settings. (line 587) * set detach-on-fork: Forks. (line 58) * set direct-call-timeout: Calling. (line 138) * set directories: Source Path. (line 178) * set disable-randomization: Starting. (line 212) * set disassemble-next-line: Machine Code. (line 285) * set disassembler-options: Machine Code. (line 258) * set disassembly-flavor: Machine Code. (line 273) * set disconnected-dprintf: Dynamic Printf. (line 96) * set disconnected-tracing: Starting and Stopping Trace Experiments. (line 55) * set displaced-stepping: Maintenance Commands. (line 156) * set dump-excluded-mappings: Core File Generation. (line 63) * set editing: Editing. (line 15) * set endian: Byte Order. (line 13) * set environment: Environment. (line 39) * set exceptions, Hurd command: Hurd Native. (line 39) * set exec-direction: Reverse Execution. (line 89) * set exec-done-display: Debugging Output. (line 11) * set exec-wrapper: Starting. (line 120) * set extended-prompt: Prompt. (line 25) * set extension-language: Show. (line 30) * set follow-exec-mode: Forks. (line 104) * set follow-fork-mode: Forks. (line 39) * set fortran repack-array-slices: Special Fortran Commands. (line 13) * set frame-filter priority: Frame Filter Management. (line 84) * set gnutarget: Target Commands. (line 28) * set guile print-stack: Guile Exception Handling. (line 6) * set hash, for remote monitors: Target Commands. (line 98) * set height: Screen Size. (line 22) * set history expansion: Command History. (line 97) * set history filename: Command History. (line 26) * set history remove-duplicates: Command History. (line 69) * set history save: Command History. (line 44) * set history size: Command History. (line 56) * set host-charset: Character Sets. (line 33) * set index-cache: Index Files. (line 79) * set indirect-call-timeout: Calling. (line 160) * set inferior-tty: Input/Output. (line 49) * set input-radix: Numbers. (line 14) * set interactive-mode: Other Misc Settings. (line 6) * set language: Manually. (line 9) * set libthread-db-search-path: Threads. (line 300) * set listsize: List. (line 43) * set logging enabled: Logging Output. (line 9) * set mach-exceptions: Darwin. (line 27) * set max-completions: Completion. (line 81) * set max-user-call-depth: Define. (line 135) * set max-value-size: Value Sizes. (line 12) * set may-call-functions: Calling. (line 76) * set mem inaccessible-by-default: Memory Region Attributes. (line 123) * set mi-async: Asynchronous and non-stop modes. (line 15) * set mips abi: MIPS. (line 32) * set mips compression: MIPS. (line 49) * set mips mask-address: MIPS. (line 80) * set mipsfpu: MIPS Embedded. (line 13) * set mpx bound: x86. (line 60) * set multiple-symbols: Ambiguous Expressions. (line 50) * set new-console: Cygwin Native. (line 72) * set new-group: Cygwin Native. (line 81) * set non-stop: Non-Stop Mode. (line 35) * set opaque-type-resolution: Symbols. (line 621) * set osabi: ABI. (line 11) * set output-radix: Numbers. (line 30) * set overload-resolution: Debugging C Plus Plus. (line 59) * set pagination: Screen Size. (line 41) * set powerpc: PowerPC Embedded. (line 54) * set print: Print Settings. (line 11) * set print entry-values: Print Settings. (line 260) * set print finish: Continuing and Stepping. (line 117) * set print frame-arguments: Print Settings. (line 200) * set print frame-info: Print Settings. (line 360) * set print inferior-events: Inferiors Connections and Programs. (line 188) * set print symbol-loading: Symbols. (line 639) * set print thread-events: Threads. (line 279) * set print type hex: Symbols. (line 85) * set print type methods: Symbols. (line 44) * set print type nested-type-limit: Symbols. (line 57) * set print type typedefs: Symbols. (line 68) * set processor: Targets. (line 31) * set procfs-file: Process Information. (line 112) * set procfs-trace: Process Information. (line 106) * set prompt: Prompt. (line 16) * set python dont-write-bytecode: Python Commands. (line 67) * set python ignore-environment: Python Commands. (line 52) * set python print-stack: Python Commands. (line 44) * set radix: Numbers. (line 43) * set range-stepping: Continuing and Stepping. (line 228) * set ravenscar task-switching off: Ravenscar Profile. (line 14) * set ravenscar task-switching on: Ravenscar Profile. (line 10) * set record: Process Record and Replay. (line 416) * set record btrace: Process Record and Replay. (line 204) * set record btrace bts: Process Record and Replay. (line 277) * set record btrace pt: Process Record and Replay. (line 300) * set record full: Process Record and Replay. (line 154) * set remote: Remote Configuration. (line 6) * set remote system-call-allowed: system. (line 37) * set remote-mips64-transfers-32bit-regs: MIPS. (line 90) * set remotecache: Caching Target Data. (line 20) * set remoteflow: Remote Configuration. (line 48) * set schedule-multiple: All-Stop Mode. (line 81) * set script-extension: Extending GDB. (line 20) * set sh calling-convention: Super-H. (line 9) * set shell: Cygwin Native. (line 108) * set signal-thread: Hurd Native. (line 21) * set signals, Hurd command: Hurd Native. (line 11) * set sigs, Hurd command: Hurd Native. (line 11) * set sigthread: Hurd Native. (line 21) * set solib-absolute-prefix: Files. (line 411) * set solib-search-path: Files. (line 487) * set source open: Disable Reading Source. (line 13) * set stack-cache: Caching Target Data. (line 28) * set startup-quietly: Mode Options. (line 26) * set startup-with-shell: Starting. (line 145) * set step-mode: Continuing and Stepping. (line 91) * set stop-on-solib-events: Files. (line 388) * set stopped, Hurd command: Hurd Native. (line 31) * set struct-convention: x86. (line 7) * set style: Output Styling. (line 6) * set substitute-path: Source Path. (line 185) * set suppress-cli-notifications: Other Misc Settings. (line 24) * set sysroot: Files. (line 411) * set target-charset: Character Sets. (line 28) * set target-file-system-kind (unix|dos-based|auto): Files. (line 501) * set target-wide-charset: Character Sets. (line 61) * set task, Hurd commands: Hurd Native. (line 48) * set tcp: Remote Configuration. (line 130) * set thread, Hurd command: Hurd Native. (line 90) * set trace-buffer-size: Starting and Stopping Trace Experiments. (line 107) * set trace-commands: Messages/Warnings. (line 65) * set trace-notes: Starting and Stopping Trace Experiments. (line 126) * set trace-stop-notes: Starting and Stopping Trace Experiments. (line 132) * set trace-user: Starting and Stopping Trace Experiments. (line 122) * set trust-readonly-sections: Files. (line 290) * set tui active-border-mode: TUI Configuration. (line 24) * set tui border-kind: TUI Configuration. (line 9) * set tui border-mode: TUI Configuration. (line 23) * set tui compact-source: TUI Configuration. (line 54) * set tui mouse-events: TUI Configuration. (line 60) * set tui tab-width: TUI Configuration. (line 49) * set unwind-on-signal: Calling. (line 36) * set unwind-on-terminating-exception: Calling. (line 53) * set unwind-on-timeout: Calling. (line 65) * set unwindonsignal: Calling. (line 36) * set use-coredump-filter: Core File Generation. (line 36) * set variable: Assignment. (line 16) * set verbose: Messages/Warnings. (line 15) * set watchdog: Maintenance Commands. (line 844) * set width: Screen Size. (line 22) * set write: Patching. (line 15) * set_debug_traps: Stub Contents. (line 9) * set-breakpoint-condition!: Breakpoints In Guile. (line 216) * set-breakpoint-enabled!: Breakpoints In Guile. (line 165) * set-breakpoint-hit-count!: Breakpoints In Guile. (line 190) * set-breakpoint-ignore-count!: Breakpoints In Guile. (line 184) * set-breakpoint-silent!: Breakpoints In Guile. (line 176) * set-breakpoint-stop!: Breakpoints In Guile. (line 224) * set-breakpoint-task!: Breakpoints In Guile. (line 208) * set-breakpoint-thread!: Breakpoints In Guile. (line 198) * set-iterator-progress!: Iterators In Guile. (line 60) * set-mark (C-@@): Miscellaneous Commands. (line 33) * set-memory-port-read-buffer-size!: Memory Ports in Guile. (line 44) * set-memory-port-write-buffer-size!: Memory Ports in Guile. (line 59) * set-objfile-pretty-printers!: Objfiles In Guile. (line 40) * set-parameter-value!: Parameters In Guile. (line 108) * set-pretty-printer-enabled!: Guile Pretty Printing API. (line 31) * set-pretty-printers!: Guile Pretty Printing API. (line 38) * set-progspace-pretty-printers!: Progspaces In Guile. (line 57) * share: Files. (line 364) * sharedlibrary: Files. (line 364) * shell: Shell Commands. (line 10) * shell-transpose-words (M-C-t): Commands For Killing. (line 32) * show: Help. (line 150) * show ada print-signatures: Overloading support for Ada. (line 36) * show ada source-charset: Ada Source Character Set. (line 18) * show ada trust-PAD-over-XVS: Ada Glitches. (line 42) * show agent: In-Process Agent. (line 51) * show always-read-ctf: Symbols. (line 763) * show amdgpu precise-memory: AMD GPU. (line 186) * show annotate: Annotations Overview. (line 34) * show architecture: Targets. (line 21) * show args: Arguments. (line 28) * show arm: ARM. (line 13) * show auto-load: Auto-loading. (line 37) * show auto-load gdb-scripts: Auto-loading sequences. (line 17) * show auto-load guile-scripts: Guile Auto-loading. (line 20) * show auto-load libthread-db: libthread_db.so.1 file. (line 25) * show auto-load local-gdbinit: Init File in the Current Directory. (line 18) * show auto-load python-scripts: Python Auto-loading. (line 20) * show auto-load safe-path: Auto-loading safe path. (line 46) * show auto-load scripts-directory: objfile-gdbdotext file. (line 65) * show auto-solib-add: Files. (line 349) * show backtrace: Backtrace. (line 173) * show basenames-may-differ: Files. (line 564) * show breakpoint always-inserted: Set Breaks. (line 434) * show breakpoint auto-hw: Set Breaks. (line 414) * show breakpoint condition-evaluation: Set Breaks. (line 455) * show breakpoint pending: Set Breaks. (line 383) * show can-use-hw-watchpoints: Set Watchpoints. (line 122) * show case-sensitive: Symbols. (line 40) * show charset: Character Sets. (line 52) * show check range: Range Checking. (line 34) * show check type: Type Checking. (line 35) * show circular-trace-buffer: Starting and Stopping Trace Experiments. (line 100) * show code-cache: Caching Target Data. (line 42) * show coerce-float-to-double: ABI. (line 54) * show com1base: DJGPP Native. (line 134) * show com1irq: DJGPP Native. (line 134) * show com2base: DJGPP Native. (line 134) * show com2irq: DJGPP Native. (line 134) * show com3base: DJGPP Native. (line 134) * show com3irq: DJGPP Native. (line 134) * show com4base: DJGPP Native. (line 134) * show com4irq: DJGPP Native. (line 134) * show commands: Command History. (line 110) * show complaints: Messages/Warnings. (line 35) * show configuration: Help. (line 183) * show confirm: Messages/Warnings. (line 57) * show convenience: Convenience Vars. (line 37) * show copying: Help. (line 174) * show cp-abi: ABI. (line 57) * show cwd: Working Directory. (line 27) * show cygwin-exceptions: Cygwin Native. (line 68) * show data-directory: Data Files. (line 16) * show dcache line-size: Caching Target Data. (line 68) * show dcache size: Caching Target Data. (line 64) * show debug: Debugging Output. (line 21) * show debug arc: ARC. (line 14) * show debug auto-load: Auto-loading verbose mode. (line 30) * show debug bfd-cache: File Caching. (line 27) * show debug darwin: Darwin. (line 13) * show debug entry-values: Tail Call Frames. (line 55) * show debug libthread-db: Threads. (line 338) * show debug mach-o: Darwin. (line 23) * show debug mips: MIPS. (line 104) * show debug monitor: Target Commands. (line 111) * show debug nios2: Nios II. (line 14) * show debug py-breakpoint: Python Commands. (line 101) * show debug py-unwind: Python Commands. (line 106) * show debug skip: Skipping Over Functions and Files. (line 153) * show debug threads: Threads. (line 343) * show debug tui: TUI Configuration. (line 68) * show debug-file-directory: Separate Debug Files. (line 82) * show debuginfod enabled: Debuginfod Settings. (line 27) * show debuginfod urls: Debuginfod Settings. (line 38) * show debuginfod verbose: Debuginfod Settings. (line 47) * show default-collect: Tracepoint Actions. (line 150) * show detach-on-fork: Forks. (line 73) * show direct-call-timeout: Calling. (line 151) * show directories: Source Path. (line 182) * show disassemble-next-line: Machine Code. (line 285) * show disassembler-options: Machine Code. (line 270) * show disassembly-flavor: Machine Code. (line 282) * show disconnected-dprintf: Dynamic Printf. (line 101) * show disconnected-tracing: Starting and Stopping Trace Experiments. (line 62) * show displaced-stepping: Maintenance Commands. (line 156) * show editing: Editing. (line 22) * show environment: Environment. (line 33) * show exceptions, Hurd command: Hurd Native. (line 45) * show exec-done-display: Debugging Output. (line 14) * show extended-prompt: Prompt. (line 39) * show follow-fork-mode: Forks. (line 52) * show fortran repack-array-slices: Special Fortran Commands. (line 13) * show frame-filter priority: Frame Filter Management. (line 91) * show gnutarget: Target Commands. (line 40) * show hash, for remote monitors: Target Commands. (line 104) * show height: Screen Size. (line 22) * show history: Command History. (line 102) * show host-charset: Character Sets. (line 55) * show index-cache: Index Files. (line 84) * show indirect-call-timeout: Calling. (line 175) * show inferior-tty: Input/Output. (line 54) * show input-radix: Numbers. (line 35) * show interactive-mode: Other Misc Settings. (line 20) * show language: Show. (line 10) * show libthread-db-search-path: Threads. (line 335) * show listsize: List. (line 49) * show logging: Logging Output. (line 24) * show mach-exceptions: Darwin. (line 34) * show max-completions: Completion. (line 89) * show max-user-call-depth: Define. (line 135) * show max-value-size: Value Sizes. (line 36) * show may-call-functions: Calling. (line 90) * show mem inaccessible-by-default: Memory Region Attributes. (line 129) * show mi-async: Asynchronous and non-stop modes. (line 27) * show mips abi: MIPS. (line 46) * show mips compression: MIPS. (line 72) * show mips mask-address: MIPS. (line 86) * show mipsfpu: MIPS Embedded. (line 13) * show mpx bound: x86. (line 57) * show multiple-symbols: Ambiguous Expressions. (line 70) * show new-console: Cygwin Native. (line 77) * show new-group: Cygwin Native. (line 86) * show non-stop: Non-Stop Mode. (line 38) * show opaque-type-resolution: Symbols. (line 636) * show osabi: ABI. (line 11) * show output-radix: Numbers. (line 38) * show overload-resolution: Debugging C Plus Plus. (line 76) * show pagination: Screen Size. (line 47) * show paths: Environment. (line 29) * show print: Print Settings. (line 39) * show print finish: Continuing and Stepping. (line 117) * show print inferior-events: Inferiors Connections and Programs. (line 196) * show print symbol-loading: Symbols. (line 654) * show print thread-events: Threads. (line 289) * show print type hex: Symbols. (line 94) * show print type methods: Symbols. (line 53) * show print type nested-type-limit: Symbols. (line 64) * show print type typedefs: Symbols. (line 81) * show processor: Targets. (line 31) * show procfs-file: Process Information. (line 117) * show procfs-trace: Process Information. (line 109) * show prompt: Prompt. (line 19) * show radix: Numbers. (line 43) * show range-stepping: Continuing and Stepping. (line 228) * show ravenscar task-switching: Ravenscar Profile. (line 22) * show record: Process Record and Replay. (line 422) * show record btrace: Process Record and Replay. (line 270) * show record full: Process Record and Replay. (line 172) * show remote: Remote Configuration. (line 6) * show remote system-call-allowed: system. (line 41) * show remote-mips64-transfers-32bit-regs: MIPS. (line 96) * show remotecache: Caching Target Data. (line 25) * show remoteflow: Remote Configuration. (line 52) * show script-extension: Extending GDB. (line 20) * show sh calling-convention: Super-H. (line 22) * show shell: Cygwin Native. (line 112) * show signal-thread: Hurd Native. (line 27) * show signals, Hurd command: Hurd Native. (line 17) * show sigs, Hurd command: Hurd Native. (line 17) * show sigthread: Hurd Native. (line 27) * show solib-search-path: Files. (line 498) * show source open: Disable Reading Source. (line 13) * show stack-cache: Caching Target Data. (line 33) * show startup-quietly: Mode Options. (line 26) * show stop-on-solib-events: Files. (line 394) * show stopped, Hurd command: Hurd Native. (line 36) * show struct-convention: x86. (line 15) * show style: Output Styling. (line 6) * show substitute-path: Source Path. (line 222) * show suppress-cli-notifications: Other Misc Settings. (line 78) * show sysroot: Files. (line 484) * show target-charset: Character Sets. (line 58) * show target-file-system-kind: Files. (line 501) * show target-wide-charset: Character Sets. (line 67) * show task, Hurd commands: Hurd Native. (line 56) * show tcp: Remote Configuration. (line 130) * show thread, Hurd command: Hurd Native. (line 100) * show trace-buffer-size: Starting and Stopping Trace Experiments. (line 114) * show trace-notes: Starting and Stopping Trace Experiments. (line 129) * show trace-stop-notes: Starting and Stopping Trace Experiments. (line 137) * show trace-user: Starting and Stopping Trace Experiments. (line 124) * show unwind-on-signal: Calling. (line 46) * show unwind-on-terminating-exception: Calling. (line 61) * show unwind-on-timeout: Calling. (line 72) * show unwindonsignal: Calling. (line 46) * show user: Define. (line 128) * show values: Value History. (line 47) * show verbose: Messages/Warnings. (line 21) * show version: Help. (line 164) * show warranty: Help. (line 178) * show width: Screen Size. (line 22) * show write: Patching. (line 26) * show-all-if-ambiguous: Readline Init File Syntax. (line 275) * show-all-if-unmodified: Readline Init File Syntax. (line 281) * show-mode-in-prompt: Readline Init File Syntax. (line 290) * si (stepi): Continuing and Stepping. (line 196) * signal: Signaling. (line 6) * signal annotation: Annotations for Running. (line 42) * signal-event: Cygwin Native. (line 35) * signal-name annotation: Annotations for Running. (line 22) * signal-name-end annotation: Annotations for Running. (line 22) * signal-string annotation: Annotations for Running. (line 22) * signal-string-end annotation: Annotations for Running. (line 22) * SignalEvent.stop_signal: Events In Python. (line 111) * signalled annotation: Annotations for Running. (line 22) * silent: Break Commands. (line 51) * sim, a command: Embedded Processors. (line 13) * simple-values-ref-types: GDB/MI Support Commands. (line 111) * skip: Skipping Over Functions and Files. (line 44) * skip delete: Skipping Over Functions and Files. (line 137) * skip disable: Skipping Over Functions and Files. (line 145) * skip enable: Skipping Over Functions and Files. (line 141) * skip file: Skipping Over Functions and Files. (line 100) * skip function: Skipping Over Functions and Files. (line 89) * skip-completed-text: Readline Init File Syntax. (line 296) * skip-csi-sequence (): Miscellaneous Commands. (line 52) * source: Command Files. (line 17) * source annotation: Source Annotations. (line 6) * start: Starting. (line 80) * start-kbd-macro (C-x (): Keyboard Macros. (line 6) * starti: Starting. (line 113) * starting annotation: Annotations for Running. (line 6) * STDERR: Basic Python. (line 192) * STDERR <1>: Basic Python. (line 212) * stdio-port?: I/O Ports in Guile. (line 15) * STDLOG: Basic Python. (line 195) * STDLOG <1>: Basic Python. (line 215) * STDOUT: Basic Python. (line 189) * STDOUT <1>: Basic Python. (line 209) * step: Continuing and Stepping. (line 45) * step&: Background Execution. (line 28) * stepi: Continuing and Stepping. (line 196) * stepi&: Background Execution. (line 31) * stop, a pseudo-command: Hooks. (line 21) * StopEvent.details: Events In Python. (line 90) * stopping annotation: Annotations for Running. (line 6) * strace: Create and Delete Tracepoints. (line 75) * string->argv: Commands In Guile. (line 73) * STYLE_ADDRESS: Disassembly In Python. (line 376) * STYLE_ADDRESS_OFFSET: Disassembly In Python. (line 388) * STYLE_ASSEMBLER_DIRECTIVE: Disassembly In Python. (line 354) * STYLE_COMMENT_START: Disassembly In Python. (line 434) * STYLE_IMMEDIATE: Disassembly In Python. (line 405) * STYLE_MNEMONIC: Disassembly In Python. (line 328) * STYLE_REGISTER: Disassembly In Python. (line 369) * STYLE_SUB_MNEMONIC: Disassembly In Python. (line 336) * STYLE_SYMBOL: Disassembly In Python. (line 415) * STYLE_TEXT: Disassembly In Python. (line 322) * SYMBOL_COMMON_BLOCK_DOMAIN: Symbols In Python. (line 193) * SYMBOL_FUNCTION_DOMAIN: Symbols In Python. (line 170) * SYMBOL_FUNCTION_DOMAIN <1>: Symbols In Guile. (line 123) * SYMBOL_FUNCTIONS_DOMAIN: Symbols In Guile. (line 147) * SYMBOL_LABEL_DOMAIN: Symbols In Python. (line 187) * SYMBOL_LABEL_DOMAIN <1>: Symbols In Guile. (line 140) * SYMBOL_LOC_ARG: Symbols In Python. (line 224) * SYMBOL_LOC_ARG <1>: Symbols In Guile. (line 178) * SYMBOL_LOC_BLOCK: Symbols In Python. (line 248) * SYMBOL_LOC_BLOCK <1>: Symbols In Guile. (line 199) * SYMBOL_LOC_COMMON_BLOCK: Symbols In Python. (line 265) * SYMBOL_LOC_COMPUTED: Symbols In Python. (line 262) * SYMBOL_LOC_COMPUTED <1>: Symbols In Guile. (line 213) * SYMBOL_LOC_CONST: Symbols In Python. (line 215) * SYMBOL_LOC_CONST <1>: Symbols In Guile. (line 169) * SYMBOL_LOC_CONST_BYTES: Symbols In Python. (line 251) * SYMBOL_LOC_CONST_BYTES <1>: Symbols In Guile. (line 202) * SYMBOL_LOC_LABEL: Symbols In Python. (line 245) * SYMBOL_LOC_LOCAL: Symbols In Python. (line 238) * SYMBOL_LOC_LOCAL <1>: Symbols In Guile. (line 192) * SYMBOL_LOC_OPTIMIZED_OUT: Symbols In Python. (line 259) * SYMBOL_LOC_OPTIMIZED_OUT <1>: Symbols In Guile. (line 210) * SYMBOL_LOC_REF_ARG: Symbols In Python. (line 228) * SYMBOL_LOC_REF_ARG <1>: Symbols In Guile. (line 182) * SYMBOL_LOC_REGISTER: Symbols In Python. (line 221) * SYMBOL_LOC_REGISTER <1>: Symbols In Guile. (line 175) * SYMBOL_LOC_REGPARM_ADDR: Symbols In Python. (line 233) * SYMBOL_LOC_REGPARM_ADDR <1>: Symbols In Guile. (line 187) * SYMBOL_LOC_STATIC: Symbols In Python. (line 218) * SYMBOL_LOC_STATIC <1>: Symbols In Guile. (line 172) * SYMBOL_LOC_TYPEDEF: Symbols In Python. (line 241) * SYMBOL_LOC_TYPEDEF <1>: Symbols In Guile. (line 195) * SYMBOL_LOC_UNDEF: Symbols In Python. (line 211) * SYMBOL_LOC_UNDEF <1>: Symbols In Guile. (line 165) * SYMBOL_LOC_UNRESOLVED: Symbols In Python. (line 254) * SYMBOL_LOC_UNRESOLVED <1>: Symbols In Guile. (line 205) * SYMBOL_MODULE_DOMAIN: Symbols In Python. (line 190) * SYMBOL_STRUCT_DOMAIN: Symbols In Python. (line 179) * SYMBOL_STRUCT_DOMAIN <1>: Symbols In Guile. (line 132) * SYMBOL_TYPE_DOMAIN: Symbols In Python. (line 173) * SYMBOL_TYPE_DOMAIN <1>: Symbols In Guile. (line 126) * SYMBOL_TYPES_DOMAIN: Symbols In Guile. (line 150) * SYMBOL_UNDEF_DOMAIN: Symbols In Python. (line 162) * SYMBOL_UNDEF_DOMAIN <1>: Symbols In Guile. (line 114) * SYMBOL_VAR_DOMAIN: Symbols In Python. (line 167) * SYMBOL_VAR_DOMAIN <1>: Symbols In Guile. (line 119) * SYMBOL_VARIABLES_DOMAIN: Symbols In Guile. (line 143) * symbol-addr-class: Symbols In Guile. (line 48) * symbol-argument?: Symbols In Guile. (line 58) * symbol-constant?: Symbols In Guile. (line 62) * symbol-file: Files. (line 51) * symbol-function?: Symbols In Guile. (line 65) * symbol-line: Symbols In Guile. (line 32) * symbol-linkage-name: Symbols In Guile. (line 39) * symbol-name: Symbols In Guile. (line 36) * symbol-needs-frame?: Symbols In Guile. (line 53) * symbol-print-name: Symbols In Guile. (line 43) * symbol-symtab: Symbols In Guile. (line 28) * symbol-type: Symbols In Guile. (line 24) * symbol-valid?: Symbols In Guile. (line 17) * symbol-value: Symbols In Guile. (line 72) * symbol-variable?: Symbols In Guile. (line 69) * symbol?: Symbols In Guile. (line 13) * Symbol.addr_class: Symbols In Python. (line 119) * Symbol.is_argument: Symbols In Python. (line 129) * Symbol.is_constant: Symbols In Python. (line 132) * Symbol.is_function: Symbols In Python. (line 135) * Symbol.is_valid: Symbols In Python. (line 145) * Symbol.is_variable: Symbols In Python. (line 138) * Symbol.line: Symbols In Python. (line 102) * Symbol.linkage_name: Symbols In Python. (line 110) * Symbol.name: Symbols In Python. (line 106) * Symbol.needs_frame: Symbols In Python. (line 124) * Symbol.print_name: Symbols In Python. (line 114) * Symbol.symtab: Symbols In Python. (line 97) * Symbol.type: Symbols In Python. (line 92) * Symbol.value: Symbols In Python. (line 152) * Symtab_and_line.is_valid: Symbol Tables In Python. (line 34) * Symtab_and_line.last: Symbol Tables In Python. (line 24) * Symtab_and_line.line: Symbol Tables In Python. (line 28) * Symtab_and_line.pc: Symbol Tables In Python. (line 20) * Symtab_and_line.symtab: Symbol Tables In Python. (line 16) * symtab-filename: Symbol Tables In Guile. (line 28) * symtab-fullname: Symbol Tables In Guile. (line 31) * symtab-global-block: Symbol Tables In Guile. (line 38) * symtab-objfile: Symbol Tables In Guile. (line 34) * symtab-static-block: Symbol Tables In Guile. (line 42) * symtab-valid?: Symbol Tables In Guile. (line 21) * symtab?: Symbol Tables In Guile. (line 17) * Symtab.filename: Symbol Tables In Python. (line 43) * Symtab.fullname: Symbol Tables In Python. (line 66) * Symtab.global_block: Symbol Tables In Python. (line 69) * Symtab.is_valid: Symbol Tables In Python. (line 59) * Symtab.linetable: Symbol Tables In Python. (line 77) * Symtab.objfile: Symbol Tables In Python. (line 47) * Symtab.producer: Symbol Tables In Python. (line 51) * Symtab.static_block: Symbol Tables In Python. (line 73) * sysinfo: DJGPP Native. (line 19) * taas: Threads. (line 229) * tab-insert (M-): Commands For Text. (line 30) * tabset: TUI Configuration. (line 49) * target: Target Commands. (line 49) * target ctf: Trace Files. (line 28) * target record: Process Record and Replay. (line 43) * target record-btrace: Process Record and Replay. (line 43) * target record-full: Process Record and Replay. (line 43) * target sim: OpenRISC 1000. (line 13) * target tfile: Trace Files. (line 28) * target-config: Guile Configuration. (line 24) * TargetConnection.description: Connections In Python. (line 62) * TargetConnection.details: Connections In Python. (line 68) * TargetConnection.is_valid: Connections In Python. (line 39) * TargetConnection.num: Connections In Python. (line 51) * TargetConnection.type: Connections In Python. (line 57) * task (Ada): Ada Tasks. (line 119) * tbreak: Set Breaks. (line 165) * tcatch: Set Catchpoints. (line 298) * tdump: tdump. (line 6) * teval (tracepoints): Tracepoint Actions. (line 118) * tfaas: Threads. (line 236) * tfile: Trace Files. (line 28) * tfind: tfind. (line 6) * thbreak: Set Breaks. (line 191) * this, inside C++ member functions: C Plus Plus Expressions. (line 20) * thread apply: Threads. (line 194) * thread find: Threads. (line 265) * thread name: Threads. (line 254) * thread THREAD-ID: Threads. (line 176) * thread-info: GDB/MI Support Commands. (line 86) * ThreadEvent.inferior_thread: Events In Python. (line 52) * ThreadExitedEvent.inferior_thread: Events In Python. (line 262) * throw-user-error: Commands In Guile. (line 81) * tilde-expand (M-~): Miscellaneous Commands. (line 30) * trace: Create and Delete Tracepoints. (line 6) * transpose-chars (C-t): Commands For Text. (line 50) * transpose-words (M-t): Commands For Text. (line 56) * tsave: Trace Files. (line 12) * tstart [ NOTES ]: Starting and Stopping Trace Experiments. (line 6) * tstatus: Starting and Stopping Trace Experiments. (line 27) * tstop [ NOTES ]: Starting and Stopping Trace Experiments. (line 16) * tty: Input/Output. (line 23) * tui disable: TUI Commands. (line 23) * tui enable: TUI Commands. (line 18) * tui layout: TUI Commands. (line 74) * tui new-layout: TUI Commands. (line 29) * tui refresh: TUI Commands. (line 126) * tui reg: TUI Commands. (line 131) * tui window height: TUI Commands. (line 159) * tui window width: TUI Commands. (line 174) * TuiWindow.erase: TUI Windows In Python. (line 51) * TuiWindow.height: TUI Windows In Python. (line 43) * TuiWindow.is_valid: TUI Windows In Python. (line 28) * TuiWindow.title: TUI Windows In Python. (line 46) * TuiWindow.width: TUI Windows In Python. (line 40) * TuiWindow.write: TUI Windows In Python. (line 54) * tvariable: Trace State Variables. (line 26) * TYPE_CODE_ARRAY: Types In Python. (line 266) * TYPE_CODE_ARRAY <1>: Types In Guile. (line 153) * TYPE_CODE_BITSTRING: Types In Python. (line 304) * TYPE_CODE_BITSTRING <1>: Types In Guile. (line 191) * TYPE_CODE_BOOL: Types In Python. (line 328) * TYPE_CODE_BOOL <1>: Types In Guile. (line 215) * TYPE_CODE_CHAR: Types In Python. (line 325) * TYPE_CODE_CHAR <1>: Types In Guile. (line 212) * TYPE_CODE_COMPLEX: Types In Python. (line 331) * TYPE_CODE_COMPLEX <1>: Types In Guile. (line 218) * TYPE_CODE_DECFLOAT: Types In Python. (line 340) * TYPE_CODE_DECFLOAT <1>: Types In Guile. (line 227) * TYPE_CODE_ENUM: Types In Python. (line 275) * TYPE_CODE_ENUM <1>: Types In Guile. (line 162) * TYPE_CODE_ERROR: Types In Python. (line 307) * TYPE_CODE_ERROR <1>: Types In Guile. (line 194) * TYPE_CODE_FIXED_POINT: Types In Python. (line 351) * TYPE_CODE_FIXED_POINT <1>: Types In Guile. (line 238) * TYPE_CODE_FLAGS: Types In Python. (line 278) * TYPE_CODE_FLAGS <1>: Types In Guile. (line 165) * TYPE_CODE_FLT: Types In Python. (line 287) * TYPE_CODE_FLT <1>: Types In Guile. (line 174) * TYPE_CODE_FUNC: Types In Python. (line 281) * TYPE_CODE_FUNC <1>: Types In Guile. (line 168) * TYPE_CODE_INT: Types In Python. (line 284) * TYPE_CODE_INT <1>: Types In Guile. (line 171) * TYPE_CODE_INTERNAL_FUNCTION: Types In Python. (line 343) * TYPE_CODE_INTERNAL_FUNCTION <1>: Types In Guile. (line 230) * TYPE_CODE_MEMBERPTR: Types In Python. (line 316) * TYPE_CODE_MEMBERPTR <1>: Types In Guile. (line 203) * TYPE_CODE_METHOD: Types In Python. (line 310) * TYPE_CODE_METHOD <1>: Types In Guile. (line 197) * TYPE_CODE_METHODPTR: Types In Python. (line 313) * TYPE_CODE_METHODPTR <1>: Types In Guile. (line 200) * TYPE_CODE_NAMESPACE: Types In Python. (line 337) * TYPE_CODE_NAMESPACE <1>: Types In Python. (line 354) * TYPE_CODE_NAMESPACE <2>: Types In Guile. (line 224) * TYPE_CODE_NAMESPACE <3>: Types In Guile. (line 241) * TYPE_CODE_PTR: Types In Python. (line 263) * TYPE_CODE_PTR <1>: Types In Guile. (line 150) * TYPE_CODE_RANGE: Types In Python. (line 296) * TYPE_CODE_RANGE <1>: Types In Guile. (line 183) * TYPE_CODE_REF: Types In Python. (line 319) * TYPE_CODE_REF <1>: Types In Guile. (line 206) * TYPE_CODE_RVALUE_REF: Types In Python. (line 322) * TYPE_CODE_RVALUE_REF <1>: Types In Guile. (line 209) * TYPE_CODE_SET: Types In Python. (line 293) * TYPE_CODE_SET <1>: Types In Guile. (line 180) * TYPE_CODE_STRING: Types In Python. (line 299) * TYPE_CODE_STRING <1>: Types In Guile. (line 186) * TYPE_CODE_STRUCT: Types In Python. (line 269) * TYPE_CODE_STRUCT <1>: Types In Guile. (line 156) * TYPE_CODE_TYPEDEF: Types In Python. (line 334) * TYPE_CODE_TYPEDEF <1>: Types In Guile. (line 221) * TYPE_CODE_UNION: Types In Python. (line 272) * TYPE_CODE_UNION <1>: Types In Guile. (line 159) * TYPE_CODE_VOID: Types In Python. (line 290) * TYPE_CODE_VOID <1>: Types In Guile. (line 177) * TYPE_CODE_XMETHOD: Types In Python. (line 347) * TYPE_CODE_XMETHOD <1>: Types In Guile. (line 234) * type-array: Types In Guile. (line 52) * type-code: Types In Guile. (line 25) * type-const: Types In Guile. (line 99) * type-field: Types In Guile. (line 129) * type-fields: Types In Guile. (line 115) * type-has-field-deep?: Guile Types Module. (line 32) * type-has-field?: Types In Guile. (line 142) * type-name: Types In Guile. (line 34) * type-num-fields: Types In Guile. (line 112) * type-pointer: Types In Guile. (line 73) * type-print-name: Types In Guile. (line 38) * type-range: Types In Guile. (line 77) * type-reference: Types In Guile. (line 81) * type-sizeof: Types In Guile. (line 43) * type-strip-typedefs: Types In Guile. (line 48) * type-tag: Types In Guile. (line 29) * type-target: Types In Guile. (line 85) * type-unqualified: Types In Guile. (line 107) * type-vector: Types In Guile. (line 60) * type-volatile: Types In Guile. (line 103) * type?: Types In Guile. (line 11) * Type.alignof: Types In Python. (line 35) * Type.array: Types In Python. (line 176) * Type.code: Types In Python. (line 41) * Type.const: Types In Python. (line 197) * Type.dynamic: Types In Python. (line 45) * Type.fields: Types In Python. (line 115) * Type.is_array_like: Types In Python. (line 99) * Type.is_scalar: Types In Python. (line 86) * Type.is_signed: Types In Python. (line 91) * Type.is_string_like: Types In Python. (line 108) * Type.name: Types In Python. (line 65) * Type.objfile: Types In Python. (line 82) * Type.optimized_out: Types In Python. (line 254) * Type.pointer: Types In Python. (line 220) * Type.range: Types In Python. (line 210) * Type.reference: Types In Python. (line 216) * Type.sizeof: Types In Python. (line 69) * Type.strip_typedefs: Types In Python. (line 224) * Type.tag: Types In Python. (line 76) * Type.target: Types In Python. (line 228) * Type.template_argument: Types In Python. (line 242) * Type.unqualified: Types In Python. (line 205) * Type.vector: Types In Python. (line 184) * Type.volatile: Types In Python. (line 201) * u (SingleKey TUI key): TUI Single Key Mode. (line 55) * u (until): Continuing and Stepping. (line 124) * undefined-command-error-code: GDB/MI Support Commands. (line 101) * undisplay: Auto Display. (line 45) * undo (C-_ or C-x C-u): Miscellaneous Commands. (line 23) * universal-argument (): Numeric Arguments. (line 10) * unix-filename-rubout (): Commands For Killing. (line 43) * unix-line-discard (C-u): Commands For Killing. (line 16) * unix-word-rubout (C-w): Commands For Killing. (line 39) * unset environment: Environment. (line 65) * unset substitute-path: Source Path. (line 214) * until: Continuing and Stepping. (line 124) * until&: Background Execution. (line 46) * unwind-stop-reason-string: Frames In Guile. (line 163) * up: Selection. (line 69) * Up: TUI Keys. (line 67) * up-silently: Selection. (line 106) * upcase-word (M-u): Commands For Text. (line 61) * update: TUI Commands. (line 157) * v (SingleKey TUI key): TUI Single Key Mode. (line 58) * value->bool: Values From Inferior In Guile. (line 246) * value->bytevector: Values From Inferior In Guile. (line 258) * value->integer: Values From Inferior In Guile. (line 250) * value->lazy-string: Values From Inferior In Guile. (line 303) * value->real: Values From Inferior In Guile. (line 254) * value->string: Values From Inferior In Guile. (line 262) * value-abs: Arithmetic In Guile. (line 35) * value-add: Arithmetic In Guile. (line 15) * value-address: Values From Inferior In Guile. (line 106) * value-call: Values From Inferior In Guile. (line 240) * value-cast: Values From Inferior In Guile. (line 129) * value-const-value: Values From Inferior In Guile. (line 229) * value-dereference: Values From Inferior In Guile. (line 143) * value-div: Arithmetic In Guile. (line 21) * value-dynamic-cast: Values From Inferior In Guile. (line 135) * value-dynamic-type: Values From Inferior In Guile. (line 114) * value-fetch-lazy!: Values From Inferior In Guile. (line 345) * value-field: Values From Inferior In Guile. (line 233) * value-lazy?: Values From Inferior In Guile. (line 328) * value-logand: Arithmetic In Guile. (line 47) * value-logior: Arithmetic In Guile. (line 49) * value-lognot: Arithmetic In Guile. (line 45) * value-logxor: Arithmetic In Guile. (line 51) * value-lsh: Arithmetic In Guile. (line 37) * value-max: Arithmetic In Guile. (line 43) * value-min: Arithmetic In Guile. (line 41) * value-mod: Arithmetic In Guile. (line 25) * value-mul: Arithmetic In Guile. (line 19) * value-neg: Arithmetic In Guile. (line 31) * value-not: Arithmetic In Guile. (line 29) * value-optimized-out?: Values From Inferior In Guile. (line 102) * value-pos: Arithmetic In Guile. (line 33) * value-pow: Arithmetic In Guile. (line 27) * value-print: Values From Inferior In Guile. (line 354) * value-reference-value: Values From Inferior In Guile. (line 221) * value-referenced-value: Values From Inferior In Guile. (line 196) * value-reinterpret-cast: Values From Inferior In Guile. (line 139) * value-rem: Arithmetic In Guile. (line 23) * value-rsh: Arithmetic In Guile. (line 39) * value-rvalue-reference-value: Values From Inferior In Guile. (line 225) * value-sub: Arithmetic In Guile. (line 17) * value-subscript: Values From Inferior In Guile. (line 236) * value-type: Values From Inferior In Guile. (line 110) * value?: Values From Inferior In Guile. (line 41) * Value.__init__: Values From Inferior. (line 126) * Value.__init__ <1>: Values From Inferior. (line 160) * Value.address: Values From Inferior. (line 70) * Value.assign: Values From Inferior. (line 170) * Value.bytes: Values From Inferior. (line 110) * Value.cast: Values From Inferior. (line 175) * Value.const_value: Values From Inferior. (line 263) * Value.dereference: Values From Inferior. (line 181) * Value.dynamic_cast: Values From Inferior. (line 267) * Value.dynamic_type: Values From Inferior. (line 84) * Value.fetch_lazy: Values From Inferior. (line 453) * Value.format_string: Values From Inferior. (line 275) * Value.is_lazy: Values From Inferior. (line 99) * Value.is_optimized_out: Values From Inferior. (line 75) * Value.lazy_string: Values From Inferior. (line 431) * Value.reference_value: Values From Inferior. (line 259) * Value.referenced_value: Values From Inferior. (line 234) * Value.reinterpret_cast: Values From Inferior. (line 271) * Value.string: Values From Inferior. (line 399) * Value.to_array: Values From Inferior. (line 393) * Value.type: Values From Inferior. (line 80) * value?: Arithmetic In Guile. (line 59) * value>=?: Arithmetic In Guile. (line 61) * vi-cmd-mode-string: Readline Init File Syntax. (line 309) * vi-editing-mode (M-C-j): Miscellaneous Commands. (line 92) * vi-ins-mode-string: Readline Init File Syntax. (line 320) * visible-stats: Readline Init File Syntax. (line 331) * w (SingleKey TUI key): TUI Single Key Mode. (line 61) * w (with): Command Settings. (line 39) * watch: Set Watchpoints. (line 42) * watchpoint annotation: Annotations for Running. (line 50) * whatis: Symbols. (line 138) * where: Backtrace. (line 94) * while: Command Files. (line 85) * while-stepping (tracepoints): Tracepoint Actions. (line 126) * Window.click: TUI Windows In Python. (line 106) * Window.close: TUI Windows In Python. (line 73) * Window.hscroll: TUI Windows In Python. (line 92) * Window.render: TUI Windows In Python. (line 82) * Window.vscroll: TUI Windows In Python. (line 99) * winheight: TUI Commands. (line 159) * winwidth: TUI Commands. (line 174) * with command: Command Settings. (line 39) * WP_ACCESS: Breakpoints In Python. (line 95) * WP_ACCESS <1>: Breakpoints In Guile. (line 94) * WP_READ: Breakpoints In Python. (line 89) * WP_READ <1>: Breakpoints In Guile. (line 88) * WP_WRITE: Breakpoints In Python. (line 92) * WP_WRITE <1>: Breakpoints In Guile. (line 91) * x (examine memory): Memory. (line 9) * x(examine), and info line: Machine Code. (line 35) * XMethod.__init__: Xmethod API. (line 38) * XMethodMatcher.__init__: Xmethod API. (line 43) * XMethodMatcher.match: Xmethod API. (line 47) * XMethodWorker.__call__: Xmethod API. (line 73) * XMethodWorker.get_arg_types: Xmethod API. (line 60) * XMethodWorker.get_result_type: Xmethod API. (line 67) * yank (C-y): Commands For Killing. (line 70) * yank-last-arg (M-. or M-_): Commands For History. (line 83) * yank-nth-arg (M-C-y): Commands For History. (line 74) * yank-pop (M-y): Commands For Killing. (line 73)  Tag Table: Node: Top1703 Node: Summary5336 Node: Free Software7205 Node: Free Documentation7950 Node: Contributors12884 Node: Sample Session21919 Node: Invocation28988 Node: Invoking GDB29559 Node: File Options32022 Ref: --readnever35820 Node: Mode Options36294 Ref: -nx36521 Ref: -nh36641 Node: Startup43654 Ref: Option -init-eval-command44895 Node: Initialization Files46711 Ref: System Wide Init Files50428 Ref: Home Directory Init File51745 Ref: Init File in the Current Directory during Startup52952 Ref: Initialization Files-Footnote-153703 Ref: Initialization Files-Footnote-253816 Node: Quitting GDB53929 Node: Shell Commands54907 Ref: pipe56084 Node: Logging Output57650 Node: Commands58813 Node: Command Syntax59629 Node: Command Settings61853 Node: Completion64942 Ref: Completion-Footnote-172445 Node: Filename Arguments72605 Node: Command Options75088 Node: Help77590 Node: Running85364 Node: Compilation86617 Node: Starting88736 Ref: set exec-wrapper94682 Ref: set startup-with-shell95811 Ref: set auto-connect-native-target96908 Node: Arguments101484 Node: Environment102805 Ref: set environment104747 Ref: unset environment105957 Node: Working Directory107011 Ref: set cwd command107591 Ref: cd command108579 Node: Input/Output109293 Node: Attach111421 Ref: set exec-file-mismatch112674 Node: Kill Process114882 Node: Inferiors Connections and Programs115891 Ref: add_inferior_cli120919 Ref: remove_inferiors_cli122985 Node: Inferior-Specific Breakpoints127057 Node: Threads128806 Ref: thread numbers130983 Ref: thread ID lists131885 Ref: global thread numbers132969 Ref: info_threads134524 Ref: thread apply all137230 Ref: set libthread-db-search-path142260 Node: Forks144582 Node: Checkpoint/Restart151384 Ref: Checkpoint/Restart-Footnote-1155968 Node: Stopping156003 Node: Breakpoints157319 Node: Set Breaks160620 Node: Set Watchpoints184919 Node: Set Catchpoints194597 Ref: catch syscall200245 Node: Delete Breaks208126 Node: Disabling210908 Node: Conditions214405 Node: Break Commands220427 Node: Dynamic Printf224120 Node: Save Breakpoints229324 Node: Static Probe Points230515 Ref: enable probes233143 Ref: Static Probe Points-Footnote-1234805 Ref: Static Probe Points-Footnote-2234969 Node: Error in Breakpoints235109 Node: Breakpoint-related Warnings235845 Node: Continuing and Stepping238172 Ref: range stepping248332 Node: Skipping Over Functions and Files249444 Node: Signals255542 Ref: stepping and signal handlers260298 Ref: stepping into signal handlers261126 Ref: extra signal information262387 Node: Thread Stops264885 Node: All-Stop Mode266028 Ref: set scheduler-locking267525 Node: Non-Stop Mode270486 Node: Background Execution273955 Node: Thread-Specific Breakpoints276251 Node: Interrupted System Calls278528 Node: Observer Mode280046 Node: Reverse Execution283654 Ref: Reverse Execution-Footnote-1288680 Ref: Reverse Execution-Footnote-2289307 Node: Process Record and Replay289357 Node: Stack311455 Node: Frames313088 Node: Backtrace315470 Ref: backtrace-command315807 Ref: set backtrace past-main322446 Ref: set backtrace past-entry322790 Ref: set backtrace limit323381 Ref: Backtrace-Footnote-1324033 Node: Selection324225 Node: Frame Info329120 Node: Frame Apply333658 Node: Frame Filter Management338256 Ref: disable frame-filter all338788 Node: Source343168 Node: List344294 Node: Location Specifications348070 Node: Linespec Locations352716 Node: Explicit Locations356230 Node: Address Locations359573 Node: Edit361367 Ref: Edit-Footnote-1363106 Node: Search363345 Node: Source Path364185 Ref: set substitute-path373477 Node: Machine Code375753 Ref: disassemble377815 Node: Disable Reading Source388023 Node: Data388805 Ref: print options389668 Node: Expressions400978 Node: Ambiguous Expressions403113 Node: Variables406403 Node: Arrays413093 Node: Output Formats415664 Ref: Output Formats-Footnote-1419341 Node: Memory419510 Ref: addressable memory unit426793 Node: Memory Tagging428311 Node: Auto Display431030 Node: Print Settings435728 Ref: set print address436026 Ref: set print symbol439800 Ref: set print array440300 Ref: set print array-indexes440644 Ref: set print nibbles441146 Ref: set print characters441721 Ref: set print elements442832 Ref: set print frame-arguments443992 Ref: set print raw-frame-arguments446217 Ref: set print entry-values446645 Ref: set print frame-info451096 Ref: set print repeats452846 Ref: set print max-depth453508 Ref: set print memory-tag-violations455272 Ref: set print null-stop455715 Ref: set print pretty456047 Ref: set print raw-values456646 Ref: set print union457691 Ref: set print object460061 Ref: set print static-members460871 Ref: set print vtbl461580 Node: Pretty Printing461988 Node: Pretty-Printer Introduction462504 Node: Pretty-Printer Example464279 Node: Pretty-Printer Commands465067 Node: Value History468007 Node: Convenience Vars470549 Node: Convenience Funs478603 Ref: $_shell convenience function483625 Node: Registers489944 Ref: info_registers_reggroup490617 Ref: standard registers491188 Ref: Registers-Footnote-1496199 Node: Floating Point Hardware496602 Node: Vector Unit497142 Node: OS Information497533 Ref: linux info os infotypes499577 Node: Memory Region Attributes504212 Node: Dump/Restore Files508968 Node: Core File Generation511451 Ref: set use-coredump-filter513154 Ref: set dump-excluded-mappings514658 Node: Character Sets514968 Node: Caching Target Data521453 Ref: Caching Target Data-Footnote-1524421 Node: Searching Memory524659 Node: Value Sizes527854 Ref: set max-value-size528281 Node: Optimized Code529534 Node: Inline Functions531227 Node: Tail Call Frames533902 Ref: set debug entry-values536128 Node: Macros540281 Ref: Macros-Footnote-1547991 Node: Tracepoints548152 Node: Set Tracepoints550234 Node: Create and Delete Tracepoints553200 Node: Enable and Disable Tracepoints559791 Node: Tracepoint Passcounts561051 Node: Tracepoint Conditions562474 Node: Trace State Variables564184 Node: Tracepoint Actions566419 Node: Listing Tracepoints573400 Node: Listing Static Tracepoint Markers575126 Node: Starting and Stopping Trace Experiments576986 Ref: disconnected tracing578743 Node: Tracepoint Restrictions583263 Node: Analyze Collected Data587088 Node: tfind588414 Node: tdump592996 Node: save tracepoints595543 Node: Tracepoint Variables596059 Node: Trace Files597227 Node: Overlays599647 Node: How Overlays Work600371 Ref: A code overlay602910 Node: Overlay Commands606389 Node: Automatic Overlay Debugging610663 Node: Overlay Sample Program612838 Node: Languages614639 Node: Setting615826 Node: Filenames617547 Node: Manually618430 Node: Automatically619683 Node: Show620756 Ref: show language621048 Node: Checks622102 Node: Type Checking623111 Node: Range Checking624964 Node: Supported Languages627392 Node: C628741 Node: C Operators629713 Node: C Constants634336 Node: C Plus Plus Expressions637357 Node: C Defaults640749 Node: C Checks641433 Node: Debugging C641993 Node: Debugging C Plus Plus642513 Node: Decimal Floating Point648235 Node: D649525 Node: Go649783 Node: Objective-C650921 Node: Method Names in Commands651384 Node: The Print Command with Objective-C653133 Node: OpenCL C653800 Node: OpenCL C Datatypes654075 Node: OpenCL C Expressions654458 Node: OpenCL C Operators654815 Node: Fortran655047 Node: Fortran Types656042 Node: Fortran Operators658155 Node: Fortran Intrinsics659244 Node: Special Fortran Commands661984 Node: Pascal663409 Node: Rust663924 Node: Modula-2667140 Node: M2 Operators668121 Node: Built-In Func/Proc671361 Node: M2 Constants674371 Node: M2 Types676032 Node: M2 Defaults679282 Node: Deviations679891 Node: M2 Checks681008 Node: M2 Scope681833 Node: GDB/M2682881 Node: Ada683846 Node: Ada Mode Intro685150 Node: Omissions from Ada686662 Node: Additions to Ada691056 Node: Overloading support for Ada695509 Node: Stopping Before Main Program697169 Node: Ada Exceptions697728 Node: Ada Tasks698939 Node: Ada Tasks and Core Files707517 Node: Ravenscar Profile708368 Node: Ada Source Character Set710575 Node: Ada Glitches711384 Node: Unsupported Languages715490 Node: Symbols716188 Ref: quoting names716791 Node: Altering752698 Node: Assignment753736 Node: Jumping756954 Node: Signaling759846 Node: Returning762855 Node: Calling766266 Ref: stack unwind settings767889 Ref: set unwind-on-timeout769217 Node: Patching776711 Node: Compiling and Injecting Code777861 Ref: set debug compile781576 Ref: set debug compile-cplus-types781834 Node: GDB Files792192 Node: Files793040 Ref: Shared Libraries808120 Ref: Files-Footnote-1820615 Node: File Caching820748 Node: Separate Debug Files821934 Ref: build ID823199 Ref: debug-file-directory825751 Node: MiniDebugInfo834596 Node: Index Files837059 Node: Debug Names841249 Node: Symbol Errors842615 Node: Data Files846299 Node: Targets847283 Node: Active Targets848815 Node: Target Commands849905 Ref: load854466 Ref: flash-erase855687 Node: Byte Order855747 Node: Remote Debugging857226 Node: Connecting858497 Ref: --multi Option in Types of Remote Connnections860791 Ref: Attaching in Types of Remote Connections862286 Ref: Host and target files863198 Node: File Transfer872092 Node: Server873047 Ref: Running gdbserver874679 Ref: Attaching to a program876997 Ref: Other Command-Line Arguments for gdbserver879630 Ref: Monitor Commands for gdbserver884160 Ref: Server-Footnote-1890445 Node: Remote Configuration890569 Ref: set remotebreak891873 Ref: set remote hardware-watchpoint-limit893423 Ref: set remote hardware-breakpoint-limit893423 Ref: set remote hardware-watchpoint-length-limit893945 Ref: set remote exec-file894420 Node: Remote Stub908681 Node: Stub Contents911640 Node: Bootstrapping913795 Node: Debug Session917674 Node: Configurations919759 Node: Native920528 Node: BSD libkvm Interface921154 Node: Process Information922230 Node: DJGPP Native927994 Node: Cygwin Native934719 Node: Non-debug DLL Symbols939816 Node: Hurd Native944083 Node: Darwin949591 Node: FreeBSD950900 Node: Embedded OS951628 Node: Embedded Processors952039 Node: ARC953085 Node: ARM953644 Node: BPF956686 Node: M68K957182 Node: MicroBlaze957355 Node: MIPS Embedded958848 Node: OpenRISC 1000960193 Node: PowerPC Embedded961119 Node: AVR964590 Node: CRIS964966 Node: Super-H966000 Node: Architectures967087 Node: AArch64967527 Ref: vl968858 Ref: vq968971 Ref: vg969083 Ref: AArch64 SME969130 Ref: svl970893 Ref: svq971053 Ref: svg971167 Ref: aarch64 sme svcr971961 Ref: AArch64 SME2977194 Ref: AArch64 PAC978714 Node: x86981383 Ref: x86-Footnote-1986348 Node: Alpha986434 Node: MIPS986566 Node: HPPA990576 Node: PowerPC991110 Node: Nios II991894 Node: Sparc64992307 Node: S12Z994691 Node: AMD GPU995004 Ref: AMD GPU Signals999162 Ref: AMD GPU Attaching Restrictions1004939 Node: Controlling GDB1005667 Node: Prompt1006614 Node: Editing1008372 Node: Command History1009734 Node: Screen Size1015116 Node: Output Styling1017224 Ref: style_disassembler_enabled1019067 Node: Numbers1027363 Node: ABI1029409 Node: Auto-loading1032702 Ref: set auto-load off1033780 Ref: show auto-load1034432 Ref: info auto-load1035219 Node: Init File in the Current Directory1038519 Ref: set auto-load local-gdbinit1039102 Ref: show auto-load local-gdbinit1039288 Ref: info auto-load local-gdbinit1039456 Node: libthread_db.so.1 file1039608 Ref: set auto-load libthread-db1040571 Ref: show auto-load libthread-db1040706 Ref: info auto-load libthread-db1040847 Node: Auto-loading safe path1041035 Ref: set auto-load safe-path1042340 Ref: show auto-load safe-path1043107 Ref: add-auto-load-safe-path1043234 Node: Auto-loading verbose mode1046209 Ref: set debug auto-load1047372 Ref: show debug auto-load1047477 Node: Messages/Warnings1047603 Ref: confirmation requests1049073 Node: Debugging Output1050313 Ref: set debug amd-dbgapi-lib1051732 Ref: set debug amd-dbgapi1052393 Node: Other Misc Settings1062982 Node: Extending GDB1066216 Node: Sequences1068061 Node: Define1068723 Node: Hooks1074708 Node: Command Files1077138 Node: Output1082375 Ref: %V Format Specifier1087399 Ref: eval1088316 Node: Auto-loading sequences1088482 Ref: set auto-load gdb-scripts1088985 Ref: show auto-load gdb-scripts1089113 Ref: info auto-load gdb-scripts1089247 Node: Aliases1089482 Node: Command aliases default args1093021 Ref: Command aliases default args-Footnote-11096842 Node: Python1096996 Node: Python Commands1098187 Ref: set_python_print_stack1099614 Ref: Python Commands-Footnote-11102832 Node: Python API1102926 Node: Basic Python1106101 Ref: prompt_hook1118461 Ref: gdb_architecture_names1119071 Ref: gdbpy_connections1119422 Node: Threading in GDB1122127 Node: Exception Handling1124726 Node: Values From Inferior1127644 Ref: Value.assign1134895 Node: Types In Python1148819 Ref: Type.is_array_like1152973 Node: Pretty Printing API1162136 Node: Selecting Pretty-Printers1168856 Node: Writing a Pretty-Printer1171643 Node: Type Printing API1177195 Node: Frame Filter API1179859 Node: Frame Decorator API1187317 Ref: frame_args1191140 Node: Writing a Frame Filter1194540 Node: Unwinding Frames in Python1206150 Ref: gdb.PendingFrame.create_unwind_info1209491 Ref: gdb.unwinder.FrameId1214512 Ref: Managing Registered Unwinders1217902 Node: Xmethods In Python1219218 Node: Xmethod API1222142 Node: Writing an Xmethod1226090 Node: Inferiors In Python1232018 Ref: gdbpy_inferior_connection1232989 Ref: gdbpy_inferior_read_memory1235667 Ref: choosing attribute names1238115 Node: Events In Python1239254 Node: Threads In Python1253866 Ref: inferior_thread_ptid1255420 Node: Recordings In Python1259424 Node: CLI Commands In Python1266881 Node: GDB/MI Commands In Python1276930 Node: GDB/MI Notifications In Python1283713 Node: Parameters In Python1285422 Node: Functions In Python1294382 Node: Progspaces In Python1296631 Node: Objfiles In Python1303752 Node: Frames In Python1310916 Ref: gdbpy_frame_read_register1317368 Node: Blocks In Python1319728 Node: Symbols In Python1324491 Node: Symbol Tables In Python1335600 Node: Line Tables In Python1338901 Node: Breakpoints In Python1341812 Ref: python_breakpoint_thread1348647 Ref: python_breakpoint_inferior1349123 Node: Finish Breakpoints in Python1355769 Node: Lazy Strings In Python1357935 Node: Architectures In Python1360223 Ref: gdbpy_architecture_name1360692 Ref: gdbpy_architecture_registers1363015 Ref: gdbpy_architecture_reggroups1363344 Node: Registers In Python1363551 Node: Connections In Python1365893 Node: TUI Windows In Python1370885 Ref: python-window-click1375810 Node: Disassembly In Python1376304 Ref: DisassembleInfo Class1376700 Ref: Disassembler Class1382533 Ref: DisassemblerResult Class1384948 Ref: Disassembler Styling Parts1388694 Ref: Disassembler Style Constants1392099 Ref: builtin_disassemble1400248 Node: Missing Debug Info In Python1403927 Node: Python Auto-loading1410010 Ref: set auto-load python-scripts1410651 Ref: show auto-load python-scripts1410755 Ref: info auto-load python-scripts1410865 Node: Python modules1412019 Node: gdb.printing1412405 Node: gdb.types1413884 Node: gdb.prompt1416964 Node: Guile1418608 Node: Guile Introduction1419271 Node: Guile Commands1420117 Node: Guile API1422047 Node: Basic Guile1424060 Node: Guile Configuration1429866 Node: GDB Scheme Data Types1430850 Node: Guile Exception Handling1432810 Node: Values From Inferior In Guile1436944 Node: Arithmetic In Guile1453554 Node: Types In Guile1455197 Ref: Fields of a type in Guile1463742 Node: Guile Pretty Printing API1465194 Node: Selecting Guile Pretty-Printers1471090 Node: Writing a Guile Pretty-Printer1473528 Node: Commands In Guile1478749 Node: Parameters In Guile1489892 Ref: Parameters In Guile-Footnote-11497173 Node: Progspaces In Guile1497289 Node: Objfiles In Guile1499973 Node: Frames In Guile1502314 Node: Blocks In Guile1509057 Node: Symbols In Guile1513997 Node: Symbol Tables In Guile1522613 Node: Breakpoints In Guile1525684 Node: Lazy Strings In Guile1537133 Node: Architectures In Guile1539496 Node: Disassembly In Guile1544031 Node: I/O Ports in Guile1547257 Node: Memory Ports in Guile1547821 Node: Iterators In Guile1551756 Node: Guile Auto-loading1556133 Ref: set auto-load guile-scripts1556768 Ref: show auto-load guile-scripts1556870 Ref: info auto-load guile-scripts1556978 Node: Guile Modules1557953 Node: Guile Printing Module1558275 Node: Guile Types Module1559110 Node: Auto-loading extensions1560423 Node: objfile-gdbdotext file1561908 Ref: set auto-load scripts-directory1563638 Ref: with-auto-load-dir1564030 Ref: show auto-load scripts-directory1564897 Ref: add-auto-load-scripts-directory1564981 Node: dotdebug_gdb_scripts section1565465 Node: Which flavor to choose?1569287 Node: Multiple Extension Languages1571156 Node: Interpreters1572204 Node: TUI1575754 Node: TUI Overview1576822 Node: TUI Keys1579635 Node: TUI Single Key Mode1582446 Node: TUI Mouse Support1583884 Node: TUI Commands1584926 Ref: info_win_command1585905 Node: TUI Configuration1592054 Ref: tui-mouse-events1593889 Node: Emacs1594481 Node: GDB/MI1600046 Node: GDB/MI General Design1602875 Node: Context management1605401 Node: Asynchronous and non-stop modes1609252 Node: Thread groups1612275 Node: GDB/MI Command Syntax1614601 Node: GDB/MI Input Syntax1614844 Node: GDB/MI Output Syntax1616484 Node: GDB/MI Compatibility with CLI1620295 Node: GDB/MI Development and Front Ends1621052 Node: GDB/MI Output Records1625535 Node: GDB/MI Result Records1625941 Node: GDB/MI Stream Records1627347 Node: GDB/MI Async Records1628636 Node: GDB/MI Breakpoint Information1639442 Node: GDB/MI Frame Information1645528 Node: GDB/MI Thread Information1646838 Node: GDB/MI Ada Exception Information1648348 Node: GDB/MI Simple Examples1648910 Node: GDB/MI Command Description Format1651162 Node: GDB/MI Breakpoint Commands1652042 Ref: -break-insert1659400 Node: GDB/MI Catchpoint Commands1674290 Node: Shared Library GDB/MI Catchpoint Commands1674703 Node: Ada Exception GDB/MI Catchpoint Commands1676401 Node: C++ Exception GDB/MI Catchpoint Commands1680035 Node: GDB/MI Program Context1684099 Node: GDB/MI Thread Commands1688427 Node: GDB/MI Ada Tasking Commands1691768 Node: GDB/MI Program Execution1694084 Node: GDB/MI Stack Manipulation1707017 Ref: -stack-list-arguments1708961 Ref: -stack-list-frames1712831 Ref: -stack-list-locals1717149 Ref: -stack-list-variables1718746 Node: GDB/MI Variable Objects1720336 Ref: -var-set-format1730488 Ref: -var-list-children1731884 Ref: -var-update1740936 Ref: -var-set-frozen1743949 Ref: -var-set-update-range1744766 Ref: -var-set-visualizer1745307 Node: GDB/MI Data Manipulation1746890 Node: GDB/MI Tracepoint Commands1770374 Node: GDB/MI Symbol Query1782722 Ref: -symbol-info-functions1782916 Ref: -symbol-info-module-functions1787439 Ref: -symbol-info-module-variables1790441 Ref: -symbol-info-modules1794196 Ref: -symbol-info-types1796120 Ref: -symbol-info-variables1798129 Node: GDB/MI File Commands1803256 Node: GDB/MI Target Manipulation1813235 Node: GDB/MI File Transfer Commands1819989 Node: GDB/MI Ada Exceptions Commands1821336 Node: GDB/MI Support Commands1822705 Node: GDB/MI Miscellaneous Commands1828003 Ref: -interpreter-exec1840416 Node: Annotations1844448 Node: Annotations Overview1845379 Node: Server Prefix1847890 Node: Prompting1848640 Node: Errors1850201 Node: Invalidation1851109 Node: Annotations for Running1851600 Node: Source Annotations1853190 Node: Debugger Adapter Protocol1854131 Node: JIT Interface1858447 Node: Declarations1860265 Node: Registering Code1861652 Node: Unregistering Code1862650 Node: Custom Debug Info1863299 Node: Using JIT Debug Info Readers1864611 Node: Writing JIT Debug Info Readers1865655 Node: In-Process Agent1867922 Ref: Control Agent1869869 Node: In-Process Agent Protocol1870748 Node: IPA Protocol Objects1871539 Ref: agent expression object1872541 Ref: tracepoint action object1872746 Ref: tracepoint object1872826 Node: IPA Protocol Commands1875360 Node: GDB Bugs1876796 Node: Bug Criteria1877528 Node: Bug Reporting1878413 Node: Command Line Editing1885450 Node: Introduction and Notation1886102 Node: Readline Interaction1887747 Node: Readline Bare Essentials1888936 Node: Readline Movement Commands1890749 Node: Readline Killing Commands1891747 Node: Readline Arguments1893723 Node: Searching1894781 Node: Readline Init File1896971 Node: Readline Init File Syntax1898142 Node: Conditional Init Constructs1919213 Node: Sample Init File1923579 Node: Bindable Readline Commands1926701 Node: Commands For Moving1927769 Node: Commands For History1929569 Node: Commands For Text1934413 Node: Commands For Killing1938205 Node: Numeric Arguments1941012 Node: Commands For Completion1942165 Node: Keyboard Macros1944195 Node: Miscellaneous Commands1944896 Node: Readline vi Mode1948931 Node: Using History Interactively1949893 Node: History Interaction1950408 Node: Event Designators1952324 Node: Word Designators1953644 Node: Modifiers1955526 Node: In Memoriam1957153 Node: Formatting Documentation1958044 Ref: Formatting Documentation-Footnote-11961452 Node: Installing GDB1961522 Node: Requirements1962098 Ref: MPFR1963778 Ref: Expat1965434 Node: Running Configure1968397 Node: Separate Objdir1971259 Node: Config Names1974283 Node: Configure Options1975766 Node: System-wide configuration1985173 Node: System-wide Configuration Scripts1987782 Node: Maintenance Commands1989002 Ref: maint info breakpoints1990765 Ref: maint info python-disassemblers1993672 Ref: maint packet2001004 Ref: maint check libthread-db2002992 Ref: maint_libopcodes_styling2021610 Node: Remote Protocol2027333 Node: Overview2028046 Ref: Binary Data2030668 Node: Standard Replies2034032 Ref: textual error reply2034885 Node: Packets2034991 Ref: thread-id syntax2035911 Ref: extended mode2037404 Ref: ? packet2037674 Ref: bc2039194 Ref: bs2039408 Ref: read registers packet2041038 Ref: cycle step packet2043445 Ref: write register packet2046221 Ref: step with signal packet2047209 Ref: vCont packet2048661 Ref: vCtrlC packet2051956 Ref: vKill packet2054365 Ref: X packet2055893 Ref: insert breakpoint or watchpoint packet2056243 Node: Stop Reply Packets2060370 Ref: swbreak stop reason2063779 Ref: thread clone event2067392 Ref: thread create event2067780 Ref: thread exit event2069007 Node: General Query Packets2071323 Ref: qCRC packet2074263 Ref: QEnvironmentHexEncoded2077123 Ref: QEnvironmentUnset2078377 Ref: QEnvironmentReset2079341 Ref: QSetWorkingDir packet2080309 Ref: qMemTags2084847 Ref: qIsAddressTagged2085601 Ref: QMemTags2086112 Ref: QNonStop2089291 Ref: QCatchSyscalls2089798 Ref: QPassSignals2091211 Ref: QProgramSignals2092245 Ref: QThreadEvents2093628 Ref: QThreadOptions2094760 Ref: qSearch memory2098806 Ref: QStartNoAckMode2099125 Ref: qSupported2099573 Ref: multiprocess extensions2115881 Ref: install tracepoint in tracing2117991 Ref: qThreadExtraInfo2122566 Ref: qXfer read2123796 Ref: qXfer auxiliary vector read2125053 Ref: qXfer btrace read2125413 Ref: qXfer btrace-conf read2126502 Ref: qXfer executable filename read2126861 Ref: qXfer target description read2127484 Ref: qXfer library list read2127934 Ref: qXfer svr4 library list read2128602 Ref: qXfer memory map read2130925 Ref: qXfer sdata read2131328 Ref: qXfer siginfo read2131806 Ref: qXfer threads read2132214 Ref: qXfer traceframe info read2132629 Ref: qXfer unwind info block2133059 Ref: qXfer fdpic loadmap read2133297 Ref: qXfer osdata read2133745 Ref: qXfer write2133907 Ref: qXfer siginfo write2134637 Ref: General Query Packets-Footnote-12136968 Node: Architecture-Specific Protocol Details2137307 Node: ARM-Specific Protocol Details2137816 Node: ARM Breakpoint Kinds2138089 Node: ARM Memory Tag Types2138457 Node: MIPS-Specific Protocol Details2138764 Node: MIPS Register packet Format2139047 Node: MIPS Breakpoint Kinds2139990 Node: Tracepoint Packets2140416 Ref: QTEnable2149792 Ref: QTDisable2149992 Ref: qTfSTM2155701 Ref: qTsSTM2155701 Ref: qTSTMat2156622 Ref: QTBuffer-size2157801 Node: Host I/O Packets2159698 Node: Interrupts2165348 Ref: interrupting remote targets2165492 Node: Notification Packets2167724 Node: Remote Non-Stop2173207 Node: Packet Acknowledgment2176391 Node: Examples2178578 Node: File-I/O Remote Protocol Extension2179172 Node: File-I/O Overview2179634 Node: Protocol Basics2181873 Node: The F Request Packet2184178 Node: The F Reply Packet2185091 Node: The Ctrl-C Message2186033 Node: Console I/O2187712 Node: List of Supported Calls2188966 Node: open2189328 Node: close2191972 Node: read2192371 Node: write2192996 Node: lseek2193791 Node: rename2194707 Node: unlink2196166 Node: stat/fstat2197153 Node: gettimeofday2198082 Node: isatty2198530 Node: system2199142 Node: Protocol-specific Representation of Datatypes2200736 Node: Integral Datatypes2201113 Node: Pointer Values2201980 Node: Memory Transfer2202688 Node: struct stat2203316 Node: struct timeval2205566 Node: Constants2206087 Node: Open Flags2206536 Node: mode_t Values2206877 Node: Errno Values2207369 Node: Lseek Flags2208183 Node: Limits2208368 Node: File-I/O Examples2208728 Node: Library List Format2209828 Node: Library List Format for SVR4 Targets2212622 Node: Memory Map Format2215477 Node: Thread List Format2218019 Node: Traceframe Info Format2219067 Node: Branch Trace Format2220761 Node: Branch Trace Configuration Format2222467 Node: Agent Expressions2223669 Node: General Bytecode Design2226506 Node: Bytecode Descriptions2231436 Node: Using Agent Expressions2245294 Node: Varying Target Capabilities2247287 Node: Rationale2248468 Node: Target Descriptions2256021 Node: Retrieving Descriptions2257974 Node: Target Description Format2259087 Node: Predefined Target Types2269168 Node: Enum Target Types2270847 Node: Standard Target Features2271854 Node: AArch64 Features2273885 Node: ARC Features2284530 Ref: ARC Features-Footnote-12286495 Node: ARM Features2286528 Node: i386 Features2296591 Node: LoongArch Features2299079 Node: MicroBlaze Features2299698 Node: MIPS Features2300368 Node: M68K Features2301655 Node: NDS32 Features2302734 Node: Nios II Features2303818 Node: OpenRISC 1000 Features2304265 Node: PowerPC Features2304655 Node: RISC-V Features2309005 Node: RX Features2310940 Node: S/390 and System z Features2311354 Node: Sparc Features2313678 Node: TIC6x Features2314715 Node: Operating System Information2315328 Node: Process list2316172 Node: Trace File Format2317263 Node: Index Section Format2320565 Node: Debuginfod2329290 Node: Debuginfod Settings2330154 Ref: set debuginfod enabled2330337 Node: Man Pages2332156 Node: gdb man2332616 Node: gdbserver man2340902 Node: gcore man2349122 Node: gdbinit man2350280 Node: gdb-add-index man2351567 Ref: gdb-add-index2351676 Node: Copying2352582 Node: GNU Free Documentation License2390158 Node: Concept Index2415308 Node: Command and Variable Index2568801  End Tag Table  Local Variables: coding: utf-8 End: @ 1.2 log @regen and make things compile (all builds except ppc sim) @ text @d1 1 a1 1 This is gdb.info, produced by makeinfo version 6.7 from gdb.texinfo. d3 1 a3 1 Copyright (C) 1988-2024 Free Software Foundation, Inc. d23 2 a24 2 This is the Tenth Edition, of 'Debugging with GDB: the GNU Source-Level Debugger' for GDB (GDB) Version 15.1. d26 1 a26 1 Copyright (C) 1988-2024 Free Software Foundation, Inc. d109 1 a109 1 * Debuginfod:: Download debugging resources with 'debuginfod' d131 1 a131 1 * Start your program, specifying anything that might affect its d134 1 a134 1 * Make your program stop on specified conditions. d136 1 a136 1 * Examine what has happened, when your program has stopped. d138 1 a138 1 * Change things in your program, so you can experiment with d176 2 a177 2 GDB is "free software", protected by the GNU General Public License (GPL). The GPL gives you the freedom to copy or adapt a licensed d290 1 a290 1 we cannot actually acknowledge everyone here. The file 'ChangeLog' in d480 1 a480 1 One of the preliminary versions of GNU 'm4' (a generic macro d483 6 a488 6 definition within another stop working. In the following short 'm4' session, we define a macro 'foo' which expands to '0000'; we then use the 'm4' built-in 'defn' to define 'bar' as the same thing. However, when we change the open quote string to '' and the close quote string to '', the same procedure fails to define a new synonym 'baz': d496 1 a496 1 define(bar,defn('foo')) d526 3 a528 3 We need to see how the 'm4' built-in 'changequote' works. Having looked at the source, we know the relevant subroutine is 'm4_changequote', so we set a breakpoint there with the GDB 'break' command. d533 2 a534 2 Using the 'run' command, we start 'm4' running under GDB control; as long as control does not reach the 'm4_changequote' subroutine, the d544 2 a545 2 To trigger the breakpoint, we call 'changequote'. GDB suspends execution of 'm4', displaying information about the context where it d554 1 a554 1 Now we use the command 'n' ('next') to advance execution to the next d561 2 a562 2 'set_quotes' looks like a promising subroutine. We can go into it by using the command 's' ('step') instead of 'next'. 'step' goes to the d564 1 a564 1 'set_quotes'. d571 1 a571 1 The display that shows the subroutine where 'm4' is now suspended (and d573 3 a575 3 the stack. We can use the 'backtrace' command (which can also be spelled 'bt'), to see where we are in the stack as a whole: the 'backtrace' command displays a stack frame for each active subroutine. d589 2 a590 2 times, we can use 's'; the next two times we use 'n' to avoid falling into the 'xstrdup' subroutine. d604 2 a605 2 'lquote' and 'rquote' to see if they are in fact the new left and right quotes we specified. We use the command 'p' ('print') to see their d613 1 a613 1 'lquote' and 'rquote' are indeed the new left and right quotes. To look d615 1 a615 1 current line with the 'l' ('list') command. d631 1 a631 1 Let us step past the two lines that set 'len_lquote' and 'len_rquote', d643 3 a645 3 That certainly looks wrong, assuming 'len_lquote' and 'len_rquote' are meant to be the lengths of 'lquote' and 'rquote' respectively. We can set them to better values using the 'p' command, since it can print the d654 3 a656 3 Is that enough to fix the problem of using the new quotes with the 'm4' built-in 'defn'? We can allow 'm4' to continue executing with the 'c' ('continue') command, and then try the example that caused trouble d669 1 a669 1 lengths. We allow 'm4' exit by giving it an EOF as input: d674 2 a675 2 The message 'Program exited normally.' is from GDB; it indicates 'm4' has finished executing. We can end our GDB session with the GDB 'quit' d688 2 a689 2 * type 'gdb' to start GDB. * type 'quit', 'exit' or 'Ctrl-d' to exit. d704 1 a704 1 Invoke GDB by running the program 'gdb'. Once started, GDB reads d707 1 a707 1 You can also run 'gdb' with a variety of arguments and options, to d725 1 a725 1 option '-p', if you want to debug a running process: d730 1 a730 1 would attach GDB to process '1234'. With option '-p' you can omit the d739 2 a740 2 You can optionally have 'gdb' pass any arguments after the executable file to the inferior using '--args'. This option stops option d743 2 a744 2 This will cause 'gdb' to debug 'gcc', and to set 'gcc''s command-line arguments (*note Arguments::) to '-O2 -c foo.c'. d746 3 a748 3 You can run 'gdb' without printing the front material, which describes GDB's non-warranty, by specifying '--silent' (or '-q'/'--quiet'): d759 2 a760 2 to display all available options and briefly describe their use ('gdb -h' is a shorter equivalent). d763 1 a763 1 sequential order. The order makes a difference when the '-x' option is d781 1 a781 1 the arguments were specified by the '-se' and '-c' (or '-p') options d783 1 a783 1 associated option flag as equivalent to the '-se' option followed by d785 1 a785 1 option flag, if any, as equivalent to the '-c'/'-p' option followed by d790 1 a790 1 prefixing it with './', e.g. './12345'. d796 1 a796 1 For the '-s', '-e', and '-se' options, and their long form d798 1 a798 1 and/or executable file is the same as that used by the 'file' command. d804 1 a804 1 you prefer, you can flag option arguments with '--' rather than '-', d807 2 a808 2 '-symbols FILE' '-s FILE' d811 2 a812 2 '-exec FILE' '-e FILE' d816 1 a816 1 '-se FILE' d819 2 a820 2 '-core FILE' '-c FILE' d823 3 a825 3 '-pid NUMBER' '-p NUMBER' Connect to process ID NUMBER, as with the 'attach' command. d827 2 a828 2 '-command FILE' '-x FILE' d830 1 a830 1 evaluated exactly as the 'source' command would. *Note Command d833 2 a834 2 '-eval-command COMMAND' '-ex COMMAND' d838 1 a838 1 It may also be interleaved with '-command' as required. d843 2 a844 2 '-init-command FILE' '-ix FILE' d848 2 a849 2 '-init-eval-command COMMAND' '-iex COMMAND' d853 2 a854 2 '-early-init-command FILE' '-eix FILE' d858 2 a859 2 '-early-init-eval-command COMMAND' '-eiex COMMAND' d863 2 a864 2 '-directory DIRECTORY' '-d DIRECTORY' d867 2 a868 2 '-r' '-readnow' d874 1 a874 1 '--readnever' d892 2 a893 2 '-nx' '-n' d897 1 a897 1 '-nh' d903 3 a905 3 '-quiet' '-silent' '-q' d909 3 a911 3 This can also be enabled using 'set startup-quietly on'. The default is 'off'. Use 'show startup-quietly' to see the current setting. Place 'set startup-quietly on' into your early d915 4 a918 4 '-batch' Run in batch mode. Exit with status '0' after processing all the command files specified with '-x' (and all commands from initialization files, if not inhibited with '-n'). Exit with d922 1 a922 1 as if 'set confirm off' were in effect (*note Messages/Warnings::). d933 4 a936 4 '-batch-silent' Run in batch mode exactly like '-batch', but totally silently. All GDB output to 'stdout' is prevented ('stderr' is unaffected). This is much quieter than '-silent' and would be useless for an d939 2 a940 2 This is particularly useful when using targets that give 'Loading section' messages, for example. d943 1 a943 1 writing directly to 'stdout', will also be made silent. d945 1 a945 1 '-return-child-result' d950 1 a950 1 * GDB exits abnormally. E.g., due to an incorrect argument or d952 3 a954 3 it would have been without '-return-child-result'. * The user quits with an explicit value. E.g., 'quit 1'. * The child process never runs, or is not allowed to terminate, d957 2 a958 2 This option is useful in conjunction with '-batch' or '-batch-silent', when GDB is being used as a remote program loader d961 2 a962 2 '-nowindows' '-nw' d967 2 a968 2 '-windows' '-w' d972 1 a972 1 '-cd DIRECTORY' d976 2 a977 2 '-data-directory DIRECTORY' '-D DIRECTORY' d981 2 a982 2 '-fullname' '-f' d987 1 a987 1 format looks like two '\032' characters, followed by the file name, d989 1 a989 1 newline. The Emacs-to-GDB interface program uses the two '\032' d992 3 a994 3 '-annotate LEVEL' This option sets the "annotation level" inside GDB. Its effect is identical to using 'set annotate LEVEL' (*note Annotations::). The d1005 1 a1005 1 '--args' d1010 2 a1011 2 '-baud BPS' '-b BPS' d1015 1 a1015 1 '-l TIMEOUT' d1019 2 a1020 2 '-tty DEVICE' '-t DEVICE' d1023 2 a1024 2 '-tui' Activate the "Text User Interface" when starting. The Text User d1030 1 a1030 1 '-interpreter INTERP' d1036 4 a1039 4 '--interpreter=mi' (or '--interpreter=mi3') causes GDB to use the "GDB/MI interface" version 3 (*note The GDB/MI Interface: GDB/MI.) included since GDB version 9.1. GDB/MI version 2 ('mi2'), included in GDB 6.0 and version 1 ('mi1'), included in GDB 5.3, are also d1042 1 a1042 1 '-write' d1044 1 a1044 1 This is equivalent to the 'set write on' command inside GDB (*note d1047 1 a1047 1 '-statistics' d1051 1 a1051 1 '-version' d1055 1 a1055 1 '-configuration' d1075 3 a1077 3 3. Executes commands and command files specified by the '-eiex' and '-eix' command line options in their specified order. Only a restricted set of commands can be used with '-eiex' and 'eix', see d1091 3 a1093 3 7. Executes commands and command files specified by the '-iex' and '-ix' options in their specified order. Usually you should use the '-ex' and '-x' options instead, but this way you can apply settings d1099 2 a1100 2 any) in the current working directory as long as 'set auto-load local-gdbinit' is set to 'on' (*note Init File in the Current d1118 1 a1118 1 Option '-ex' does not work because the auto-loading is then turned d1121 2 a1122 2 11. Executes commands and command files specified by the '-ex' and '-x' options in their specified order. *Note Command Files::, for d1125 1 a1125 1 12. Reads the command history recorded in the "history file". *Note d1137 1 a1137 1 "command files" (*note Command Files::) and are processed by GDB in the d1141 1 a1141 1 in the order they will be loaded, you can use 'gdb --help'. d1143 1 a1143 1 The "early initialization" file is loaded very early in GDB's d1146 2 a1147 2 initialized. Only 'set' or 'source' commands should be placed into an early initialization file, and the only 'set' commands that can be used d1154 1 a1154 1 passed to '--early-init-command' or '-eix' are also early initialization d1157 1 a1157 1 '--early-init-eval-command' or '-eiex'. d1159 1 a1159 1 In contrast, the "general initialization" files are processed later, d1163 1 a1163 1 Throughout the rest of this document the term "initialization file" d1171 1 a1171 1 'set complaints') can affect subsequent processing of command line d1188 6 a1193 6 * The file 'gdb/gdbearlyinit' within the directory pointed to by the environment variable 'XDG_CONFIG_HOME', if it is defined. * The file '.config/gdb/gdbearlyinit' within the directory pointed to by the environment variable 'HOME', if it is defined. * The file '.gdbearlyinit' within the directory pointed to by the environment variable 'HOME', if it is defined. d1196 2 a1197 2 * The file 'Library/Preferences/gdb/gdbearlyinit' within the directory pointed to by the environment variable 'HOME', if it is d1199 2 a1200 2 * The file '.gdbearlyinit' within the directory pointed to by the environment variable 'HOME', if it is defined. d1203 1 a1203 1 file from being loaded using the '-nx' or '-nh' command line options, d1212 1 a1212 1 'system.gdbinit' d1214 1 a1214 1 specified with the '--with-system-gdbinit' configure option (*note d1218 1 a1218 1 'system.gdbinit.d' d1220 1 a1220 1 specified with the '--with-system-gdbinit-dir' configure option d1222 1 a1222 1 loaded in alphabetical order immediately after 'system.gdbinit' (if d1225 1 a1225 1 extension ('.py'/'.scm') or be named with a '.gdb' extension to be d1230 1 a1230 1 being loaded using the '-nx' command line option, *note Choosing Modes: d1243 3 a1245 3 '$XDG_CONFIG_HOME/gdb/gdbinit' '$HOME/.config/gdb/gdbinit' '$HOME/.gdbinit' d1248 2 a1249 2 '$HOME/Library/Preferences/gdb/gdbinit' '$HOME/.gdbinit' d1252 1 a1252 1 being loaded using the '-nx' or '-nh' command line options, *note d1255 2 a1256 2 The DJGPP port of GDB uses the name 'gdb.ini' instead of '.gdbinit' or 'gdbinit', due to the limitations of file names imposed by DOS d1258 1 a1258 1 finds a 'gdb.ini' file in your home directory, it warns you about that d1264 4 a1267 4 GDB will check the current directory for a file called '.gdbinit'. It is loaded last, after command line options other than '-x' and '-ex' have been processed. The command line options '-x' and '-ex' are processed last, after '.gdbinit' has been loaded, *note Choosing Files: d1274 1 a1274 1 from being loaded using the '-nx' command line option, *note Choosing d1280 1 a1280 1 by the 'HOME' environment variable. d1283 1 a1283 1 by the 'HOME' environment variable. d1291 5 a1295 5 'quit [EXPRESSION]' 'exit [EXPRESSION]' 'q' To exit GDB, use the 'quit' command (abbreviated 'q'), the 'exit' command, or type an end-of-file character (usually 'Ctrl-d'). If d1300 1 a1300 1 An interrupt (often 'Ctrl-c') does not exit from GDB, but rather d1307 1 a1307 1 you can release it with the 'detach' command (*note Debugging an d1318 1 a1318 1 'shell' command. d1320 2 a1321 2 'shell COMMAND-STRING' '!COMMAND-STRING' d1323 4 a1326 4 needed between '!' and COMMAND-STRING. On GNU and Unix systems, the environment variable 'SHELL', if it exists, determines which shell to run. Otherwise GDB uses the default shell ('/bin/sh' on GNU and Unix systems, 'cmd.exe' on MS-Windows, 'COMMAND.COM' on d1330 1 a1330 1 '$_shell' convenience function. *Note $_shell convenience function::. d1332 2 a1333 2 The utility 'make' is often needed in development environments. You do not have to use the 'shell' command for this purpose in GDB: d1335 8 a1342 8 'make MAKE-ARGS' Execute the 'make' program with the specified arguments. This is equivalent to 'shell make MAKE-ARGS'. 'pipe [COMMAND] | SHELL_COMMAND' '| [COMMAND] | SHELL_COMMAND' 'pipe -d DELIM COMMAND DELIM SHELL_COMMAND' '| -d DELIM COMMAND DELIM SHELL_COMMAND' d1344 1 a1344 1 no space is needed around '|'. If no COMMAND is provided, the last d1347 1 a1347 1 In case the COMMAND contains a '|', the option '-d DELIM' can be d1380 1 a1380 1 The convenience variables '$_shell_exitcode' and '$_shell_exitsignal' d1382 1 a1382 1 launched by 'shell', 'make', 'pipe' and '|'. *Note Convenience d1394 1 a1394 1 'set logging enabled [on|off]' d1396 1 a1396 1 'set logging file FILE' d1398 5 a1402 5 'gdb.txt'. 'set logging overwrite [on|off]' By default, GDB will append to the logfile. Set 'overwrite' if you want 'set logging enabled on' to overwrite the logfile instead. 'set logging redirect [on|off]' d1404 1 a1404 1 logfile. Set 'redirect' if you want output to go only to the log d1406 1 a1406 1 'set logging debugredirect [on|off]' d1408 1 a1408 1 logfile. Set 'debugredirect' if you want debug output to go only d1410 1 a1410 1 'show logging' d1446 2 a1447 2 command 'step' accepts an argument which is the number of times to step, as in 'step 5'. You can also use the 'step' command with no arguments. d1453 4 a1456 4 abbreviations are allowed; for example, 's' is specially defined as equivalent to 'step' even though there are other commands whose names start with 's'. You can test abbreviations by using them as arguments to the 'help' command. d1459 1 a1459 1 previous command. Certain commands (for example, 'run') will not repeat d1464 1 a1464 1 The 'list' and 'x' commands, when you repeat them with , d1469 1 a1469 1 in a way similar to the common utility 'more' (*note Screen Size: Screen d1474 1 a1474 1 Any text from a '#' to the end of the line is a comment; it does d1478 1 a1478 1 The 'Ctrl-o' binding is useful for repeating a complex sequence of d1490 2 a1491 2 variables or settings. These settings can be changed with the 'set' subcommands. For example, the 'print' command (*note Examining Data: d1493 2 a1494 2 the commands 'set print elements NUMBER-OF-ELEMENTS' and 'set print array-indexes', among others. d1506 1 a1506 1 The above 'set print elements 10' command changes the number of d1508 2 a1509 2 this limit of 10 to be used for printing 'some_array', then you must restore the limit back to 200, with 'set print elements 200'. d1512 2 a1513 2 example, the 'print' command supports a number of options that allow overriding relevant global print settings as set by 'set print' d1519 1 a1519 1 Alternatively, you can use the 'with' command to change a setting d1522 2 a1523 2 'with SETTING [VALUE] [-- COMMAND]' 'w SETTING [VALUE] [-- COMMAND]' d1526 2 a1527 2 SETTING is any setting you can change with the 'set' subcommands. VALUE is the value to assign to 'setting' while running 'command'. d1532 1 a1532 1 ('--') separator. This is required because some settings accept d1542 1 a1542 1 The 'with' command is particularly useful when you want to override d1549 2 a1550 2 'with' commands. For example, 'with language ada -- with print elements 10' temporarily changes the language to Ada and sets a d1572 2 a1573 2 GDB fills in the rest of the word 'breakpoints', since that is the only 'info' subcommand beginning with 'bre': d1577 2 a1578 2 You can either press at this point, to run the 'info breakpoints' command, or backspace and enter something else, if 'breakpoints' does d1580 2 a1581 2 'info breakpoints' in the first place, you might as well just type immediately after 'info bre', to exploit command abbreviations rather d1588 2 a1589 2 a breakpoint on a subroutine whose name begins with 'make_', but when you type 'b make_' GDB just sounds the bell. Typing again d1603 1 a1603 1 input ('b make_' in the example) so you can finish the command. d1606 1 a1606 1 a number to follow, then 'NUMBER' will be shown among the available d1613 1 a1613 1 Here, the option expects a number (e.g., '100'), not literal 'NUMBER'. d1617 4 a1620 4 you can press 'M-?' rather than pressing twice. 'M-?' means ' ?'. You can type this either by holding down a key designated as the shift on your keyboard (if there is one) while typing '?', or as followed by '?'. d1634 2 a1635 2 'set max-completions LIMIT' 'set max-completions unlimited' d1643 1 a1643 1 'show max-completions' d1650 1 a1650 1 you may enclose words in ''' (single quote marks) in GDB commands. d1654 1 a1654 1 This is because when completing expressions, GDB treats the '<' d1659 5 a1663 5 interactively using the 'print' or 'call' commands, you may need to distinguish whether you mean the version of 'name' that was specialized for 'int', 'name()', or the version that was specialized for 'float', 'name()'. To use the word-completion facilities in this situation, type a single quote ''' at the beginning of the function d1665 1 a1665 1 than usual when you press or 'M-?' to request word completion: d1682 3 a1684 3 don't need to distinguish whether you mean the version of 'name' that takes an 'int' parameter, 'name(int)', or the version that takes a 'float' parameter, 'name(float)'. d1695 2 a1696 2 Expressions: C Plus Plus Expressions. You can use the command 'set overload-resolution off' to disable overload resolution; see *note GDB d1709 2 a1710 2 This is because the 'gdb_stdout' is a variable of the type 'struct ui_file' that is defined in GDB sources as follows: d1754 1 a1754 1 example the user is adding '/path/that contains/two spaces/' to the d1766 2 a1767 2 For example, to load the file '/path/with spaces/to/a file' with the 'file' command (*note Commands to Specify Files: Files.), you can escape d1795 1 a1795 1 'print -pretty'. Similarly to command names, you can abbreviate a GDB d1805 3 a1807 3 abbreviations, e.g. 'print -p' (short for 'print -pretty' or printing negative 'p'?), if you specify any command option, then you must use a double-dash ('--') delimiter to indicate the end of options. d1810 4 a1813 4 either 'on' or 'off'. These are known as "boolean options". Similarly to boolean settings commands--'on' and 'off' are the typical values, but any of '1', 'yes' and 'enable' can also be used as "true" value, and any of '0', 'no' and 'disable' can also be used as "false" value. You can d1822 1 a1822 1 completing on '-' after the command name. For example: d1836 1 a1836 1 Here, the option expects a number (e.g., '100'), not literal 'NUMBER'. d1839 1 a1839 1 (For more on using the 'print' command, see *note Examining Data: d1849 1 a1849 1 command 'help'. d1851 3 a1853 3 'help' 'h' You can use 'help' (abbreviated 'h') with no arguments to display a d1880 1 a1880 1 'help CLASS' d1886 1 a1886 1 help display for the class 'status': d1908 2 a1909 2 'help COMMAND' With a command name as 'help' argument, GDB displays a short d1918 1 a1918 1 'document' command (*note document: Define.). GDB then considers d1924 2 a1925 2 'apropos [-v] REGEXP' The 'apropos' command searches through all of the GDB commands and d1928 1 a1928 1 flag '-v', which stands for 'verbose', indicates to output the full d1943 1 a1943 1 results in the below output, where 'cut for 'thread apply' is d1956 2 a1957 2 'complete ARGS' The 'complete ARGS' command lists all the possible completions for d1972 1 a1972 1 In addition to 'help', you can use the GDB commands 'info' and 'show' d1975 2 a1976 2 each of them in the appropriate context. The listings under 'info' and under 'show' in the Command, Variable, and Function Index point to all d1979 2 a1980 2 'info' This command (abbreviated 'i') is for describing the state of your d1982 4 a1985 4 function with 'info args', list the registers currently in use with 'info registers', or list the breakpoints you have set with 'info breakpoints'. You can get a complete list of the 'info' sub-commands with 'help info'. d1987 1 a1987 1 'set' d1989 2 a1990 2 variable with 'set'. For example, you can set the GDB prompt to a $-sign with 'set prompt $'. d1992 6 a1997 6 'show' In contrast to 'info', 'show' is for describing the state of GDB itself. You can change most of the things you can 'show', by using the related command 'set'; for example, you can control what number system is used for displays with 'set radix', or simply inquire which is currently in use with 'show radix'. d2000 1 a2000 1 you can use 'show' with no arguments; you may also use 'info set'. d2003 2 a2004 2 Here are several miscellaneous 'show' subcommands, all of which are exceptional in lacking corresponding 'set' commands: d2006 1 a2006 1 'show version' d2016 2 a2017 2 'show copying' 'info copying' d2020 2 a2021 2 'show warranty' 'info warranty' d2025 1 a2025 1 'show configuration' d2028 2 a2029 2 'configure' script and also configuration parameters detected automatically by 'configure'. When reporting a GDB bug (*note GDB d2076 1 a2076 1 To request debugging information, specify the '-g' option when you d2080 2 a2081 2 optimizations, using the '-O' compiler option. However, some compilers are unable to handle the '-g' and '-O' options together. Using those d2085 1 a2085 1 GCC, the GNU C/C++ compiler, supports '-g' with or without '-O', d2087 1 a2087 1 _always_ use '-g' whenever you compile a program. You may think your d2091 1 a2091 1 Older versions of the GNU C compiler permitted a variant option '-gg' d2097 1 a2097 1 preprocessor macros in the debugging information if you specify the '-g' d2100 1 a2100 1 specify the option '-g3'. d2117 3 a2119 3 'run' 'r' Use the 'run' command to start your program under GDB. You must d2121 2 a2122 2 Getting In and Out of GDB: Invocation.), or by using the 'file' or 'exec-file' command (*note Commands to Specify Files: Files.). d2125 3 a2127 3 supports processes, 'run' creates an inferior process and makes that process run your program. In some environments without processes, 'run' jumps to the start of your program. Other targets, like 'remote', are d2133 1 a2133 1 then use 'continue' to run your program. You may need 'load' first d2145 1 a2145 1 'run' command. If a shell is available on your target, the shell d2149 3 a2151 3 which shell is used with the 'SHELL' environment variable. If you do not define 'SHELL', GDB uses the default shell ('/bin/sh'). You can disable use of any shell with the 'set startup-with-shell' d2156 1 a2156 1 can use the GDB commands 'set environment' and 'unset environment' d2161 2 a2162 2 You can set your program's working directory with the command 'set cwd'. If you do not set any working directory with this command, d2171 1 a2171 1 in the 'run' command line, or you can use the 'tty' command to set d2180 1 a2180 1 When you issue the 'run' command, your program begins to execute d2183 1 a2183 1 you may call functions in your program, using the 'print' or 'call' d2191 1 a2191 1 'start' d2193 1 a2193 1 With C or C++, the main procedure name is always 'main', but other d2199 1 a2199 1 The 'start' command does the equivalent of setting a temporary d2201 1 a2201 1 the 'run' command. d2203 1 a2203 1 Some programs contain an "elaboration" phase where some startup d2207 1 a2207 1 'main' is called. It is therefore possible that the debugger stops d2212 2 a2213 2 'start' command. These arguments will be given verbatim to the underlying 'run' command. Note that the same arguments will be d2215 1 a2215 1 'start' or 'run'. d2218 1 a2218 1 In these cases, using the 'start' command would stop the execution d2222 1 a2222 1 program or use the 'starti' command. d2224 2 a2225 2 'starti' The 'starti' command does the equivalent of setting a temporary d2227 2 a2228 2 then invoking the 'run' command. For programs containing an elaboration phase, the 'starti' command will stop execution at the d2231 4 a2234 4 'set exec-wrapper WRAPPER' 'show exec-wrapper' 'unset exec-wrapper' When 'exec-wrapper' is set, the specified wrapper is used to launch d2236 1 a2236 1 command of the form 'exec WRAPPER PROGRAM'. Quoting is added to d2241 1 a2241 1 You can use any program that eventually calls 'execve' with its d2243 2 a2244 2 e.g. 'env' and 'nohup'. Any Unix shell script ending with 'exec "$@@"' will also work. d2246 1 a2246 1 For example, you can use 'env' to pass an environment variable to d2256 4 a2259 4 'set startup-with-shell' 'set startup-with-shell on' 'set startup-with-shell off' 'show startup-with-shell' d2261 1 a2261 1 target, GDB) uses it to start your program. Arguments of the 'run' d2273 1 a2273 1 'exec-wrapper' crashed, not your program. Most often, this is d2275 2 a2276 2 initialization file--such as '.cshrc' for C-shell, $'.zshenv' for the Z shell, or the file specified in the 'BASH_ENV' environment d2279 4 a2282 4 'set auto-connect-native-target' 'set auto-connect-native-target on' 'set auto-connect-native-target off' 'show auto-connect-native-target' d2285 1 a2285 1 yet (e.g., with 'target remote'), the 'run' command starts your d2289 1 a2289 1 with the 'set auto-connect-native-target off' command. d2291 2 a2292 2 If 'on', which is the default, and if the current inferior is not connected to a target already, the 'run' command automatically d2295 2 a2296 2 If 'off', and if the current inferior is not connected to a target already, the 'run' command fails with an error: d2302 1 a2302 1 always uses it with the 'run' command. d2305 1 a2305 1 the 'target native' command. For example, d2315 1 a2315 1 In case you connected explicitly to the 'native' target, GDB d2317 1 a2317 1 'run' command. Use the 'disconnect' command to disconnect. d2320 2 a2321 2 'auto-connect-native-target' setting: 'attach', 'info proc', 'info os'. d2323 2 a2324 2 'set disable-randomization' 'set disable-randomization on' d2336 1 a2336 1 'set disable-randomization off' d2342 1 a2342 1 stand-alone programs. Use 'set disable-randomization off' to try d2366 2 a2367 2 a random address. You can build such executable using 'gcc -fPIE -pie'. d2372 1 a2372 1 'show disable-randomization' d2383 1 a2383 1 'run' command. They are passed to a shell, which expands wildcard d2385 3 a2387 3 Your 'SHELL' environment variable (if it exists) specifies what shell GDB uses. If you do not define 'SHELL', GDB uses the default shell ('/bin/sh' on Unix). d2394 2 a2395 2 'run' with no arguments uses the same arguments used by the previous 'run', or those set by the 'set args' command. d2397 1 a2397 1 'set args' d2399 1 a2399 1 If 'set args' has no arguments, 'run' executes your program with no d2401 1 a2401 1 'set args' before the next 'run' is the only way to run it again d2404 1 a2404 1 'show args' d2413 1 a2413 1 The "environment" consists of a set of environment variables and their d2421 2 a2422 2 'path DIRECTORY' Add DIRECTORY to the front of the 'PATH' environment variable (the d2424 1 a2424 1 The value of 'PATH' used by GDB does not change. You may specify d2426 1 a2426 1 system-dependent separator character (':' on Unix, ';' on MS-DOS d2430 1 a2430 1 You can use the string '$cwd' to refer to whatever is the current d2432 2 a2433 2 '.' instead, it refers to the directory where you executed the 'path' command. GDB replaces '.' in the DIRECTORY argument (with d2436 2 a2437 2 'show paths' Display the list of search paths for executables (the 'PATH' d2440 1 a2440 1 'show environment [VARNAME]' d2444 1 a2444 1 program. You can abbreviate 'environment' as 'env'. d2446 1 a2446 1 'set environment VARNAME [=VALUE]' d2459 1 a2459 1 named 'foo'. (The spaces around '=' are used for clarity here; d2463 3 a2465 3 also inherits the environment set with 'set environment'. If necessary, you can avoid that by using the 'env' program as a wrapper instead of using 'set environment'. *Note set d2469 1 a2469 1 to 'gdbserver' to be used when starting the remote inferior. *note d2472 1 a2472 1 'unset environment VARNAME' d2474 2 a2475 2 program. This is different from 'set env VARNAME ='; 'unset environment' removes the variable from the environment, rather than d2479 1 a2479 1 'gdbserver' when starting the remote inferior. *note d2483 5 a2487 5 indicated by your 'SHELL' environment variable if it exists (or '/bin/sh' if not). If your 'SHELL' variable names a shell that runs an initialization file when started non-interactively--such as '.cshrc' for C-shell, $'.zshenv' for the Z shell, or the file specified in the 'BASH_ENV' environment variable for BASH--any variables you set in that d2489 2 a2490 2 variables to files that are only run when you sign on, such as '.login' or '.profile'. d2498 3 a2500 3 Each time you start your program with 'run', the inferior will be initialized with the current working directory specified by the 'set cwd' command. If no directory has been specified by this command, then d2505 1 a2505 1 'set cwd [DIRECTORY]' d2507 1 a2507 1 'glob'-expanded in order to resolve tildes ('~'). If no argument d2511 4 a2514 4 inferior. The '~' in DIRECTORY is a short for the "home directory", usually pointed to by the 'HOME' environment variable. On MS-Windows, if 'HOME' is not defined, GDB uses the concatenation of 'HOMEDRIVE' and 'HOMEPATH' as fallback. d2517 1 a2517 1 'cd' command. *Note cd command::. d2519 1 a2519 1 'show cwd' d2521 1 a2521 1 specified by 'set cwd', then the default inferior's working d2524 1 a2524 1 'cd [DIRECTORY]' d2526 1 a2526 1 DIRECTORY uses ''~''. d2532 1 a2532 1 'pwd' d2537 2 a2538 2 during its run). If you work on a system where GDB supports the 'info proc' command (*note Process Information::), you can use the 'info proc' d2553 1 a2553 1 'info terminal' d2558 1 a2558 1 redirection with the 'run' command. For example, d2562 1 a2562 1 starts your program, diverting its output to the file 'outfile'. d2565 2 a2566 2 is with the 'tty' command. This command accepts a file name as argument, and causes this file to be the default for future 'run' d2568 1 a2568 1 process, for future 'run' commands. For example, d2572 2 a2573 2 directs that processes started with subsequent 'run' commands default to do input and output on the terminal '/dev/ttyb' and have that as their d2576 1 a2576 1 An explicit redirection in 'run' overrides the 'tty' command's effect d2580 1 a2580 1 When you use the 'tty' command or redirect input in the 'run' d2582 2 a2583 2 GDB still comes from your terminal. 'tty' is an alias for 'set inferior-tty'. d2585 1 a2585 1 You can use the 'show inferior-tty' command to tell GDB to display d2589 1 a2589 1 'set inferior-tty [ TTY ]' d2594 1 a2594 1 'show inferior-tty' d2603 1 a2603 1 'attach PROCESS-ID' d2605 1 a2605 1 outside GDB. ('info files' shows your active targets.) The d2607 2 a2608 2 the PROCESS-ID of a Unix process is with the 'ps' utility, or with the 'jobs -l' shell command. d2610 1 a2610 1 'attach' does not repeat if you press a second time after d2613 2 a2614 2 To use 'attach', your program must be running in an environment which supports processes; for example, 'attach' does not work for programs on d2618 1 a2618 1 When you use 'attach', the debugger finds the program running in the d2622 1 a2622 1 'file' command to load the program. *Note Commands to Specify Files: d2627 1 a2627 1 by GDB, the option 'exec-file-mismatch' specifies how to handle the d2631 1 a2631 1 'set exec-file-mismatch 'ask|warn|off'' d2635 3 a2637 3 If 'ask', the default, display a warning and ask the user whether to load the process executable file; if 'warn', just display a warning; if 'off', don't attempt to detect a mismatch. If the user d2641 2 a2642 2 'show exec-file-mismatch' Show the current value of 'exec-file-mismatch'. d2647 1 a2647 1 processes with 'run'. You can insert breakpoints; you can step and d2649 1 a2649 1 continue running, you may use the 'continue' command after attaching GDB d2652 1 a2652 1 'detach' d2654 2 a2655 2 the 'detach' command to release it from GDB control. Detaching the process continues its execution. After the 'detach' command, that d2657 2 a2658 2 are ready to 'attach' another process or start one with 'run'. 'detach' does not repeat if you press again after executing d2662 1 a2662 1 process. If you use the 'run' command, you kill that process. By d2665 1 a2665 1 'set confirm' command (*note Optional Warnings and Messages: d2674 1 a2674 1 'kill' d2682 1 a2682 1 while you have breakpoints set on it inside GDB. You can use the 'kill' d2686 1 a2686 1 The 'kill' command is also useful if you wish to recompile and relink d2689 1 a2689 1 you next type 'run', GDB notices that the file has changed, and reads d2709 1 a2709 1 called an "inferior". An inferior typically corresponds to a process, d2718 2 a2719 2 The commands 'info inferiors' and 'info connections', which will be introduced below, accept a space-separated "ID list" as their argument d2721 4 a2724 4 be either a single non-negative number, like '5', or an ascending range of such numbers, like '5-7'. A list can consist of any combination of such elements, even duplicates or overlapping ranges are valid. E.g. '1 4-6 5 4-4' or '1 2 4-7'. d2726 1 a2726 1 To find out what inferiors exist at any moment, use 'info inferiors': d2728 1 a2728 1 'info inferiors' d2745 1 a2745 1 An asterisk '*' preceding the GDB inferior number indicates the d2755 1 a2755 1 To get information about the current inferior, use 'inferior': d2757 1 a2757 1 'inferior' d2766 1 a2766 1 'info connections': d2768 1 a2768 1 'info connections' d2782 1 a2782 1 An asterisk '*' preceding the connection number indicates the d2793 1 a2793 1 To switch focus between inferiors, use the 'inferior' command: d2795 1 a2795 1 'inferior INFNO' d2798 1 a2798 1 field of the 'info inferiors' display. d2800 1 a2800 1 The debugger convenience variable '$_inferior' contains the number of d2807 1 a2807 1 'add-inferior' and 'clone-inferior' commands. On some systems GDB can d2809 2 a2810 2 'fork' and 'exec'. To remove inferiors from the debugging session use the 'remove-inferiors' command. d2812 1 a2812 1 'add-inferior [ -copies N ] [ -exec EXECUTABLE ] [-no-connection ]' d2816 1 a2816 1 assigned to the inferior at any time by using the 'file' command d2821 6 a2826 6 inferior was connected to 'gdbserver' with 'target remote', then the new inferior will be connected to the same 'gdbserver' instance. The '-no-connection' option starts the new inferior with no connection yet. You can then for example use the 'target remote' command to connect to some other 'gdbserver' instance, use 'run' to spawn a local program, etc. d2828 1 a2828 1 'clone-inferior [ -copies N ] [ INFNO ]' d2834 1 a2834 1 variables using the 'set environment' and 'unset environment' d2851 1 a2851 1 'remove-inferiors INFNO...' d2854 1 a2854 1 use the 'kill' or 'detach' command first. d2858 2 a2859 2 'detach inferior' command (allowing it to run independently), or kill it using the 'kill inferiors' command: d2861 1 a2861 1 'detach inferior INFNO...' d2864 2 a2865 2 the list of inferiors shown by 'info inferiors', but its Description will show ''. d2867 1 a2867 1 'kill inferiors INFNO...' d2870 2 a2871 2 of inferiors shown by 'info inferiors', but its Description will show ''. d2873 4 a2876 4 After the successful completion of a command such as 'detach', 'detach inferiors', 'kill' or 'kill inferiors', or after a normal process exit, the inferior is still valid and listed with 'info inferiors', ready to be restarted. d2879 1 a2879 1 use 'set print inferior-events': d2881 4 a2884 4 'set print inferior-events' 'set print inferior-events on' 'set print inferior-events off' The 'set print inferior-events' command allows you to enable or d2889 1 a2889 1 'show print inferior-events' d2894 2 a2895 2 single program: e.g., 'print myglobal' will simply display the value of 'myglobal' in the current inferior. d2899 1 a2899 1 debug session. You can do that with the 'maint info program-spaces' d2902 1 a2902 1 'maint info program-spaces' d2910 1 a2910 1 e.g., the 'file' command. d2913 1 a2913 1 e.g., the 'core-file' command. d2915 1 a2915 1 An asterisk '*' preceding the GDB program space number indicates d2928 2 a2929 2 Here we can see that no inferior is running the program 'hello', while 'process 21561' is running the program 'goodbye'. On some d2932 1 a2932 1 both the parent and child processes of a 'vfork' call. For d2941 1 a2941 1 program space as a result of inferior 1 having executed a 'vfork' d2957 2 a2958 2 'break LOCSPEC inferior INFERIOR-ID' 'break LOCSPEC inferior INFERIOR-ID if ...' d2962 1 a2962 1 Use the qualifier 'inferior INFERIOR-ID' with a breakpoint command d2966 1 a2966 1 column of the 'info inferiors' output. d2968 1 a2968 1 If you do not specify 'inferior INFERIOR-ID' when you set a d2972 2 a2973 2 You can use the 'inferior' qualifier on conditional breakpoints as well; in this case, place 'inferior INFERIOR-ID' before or after d2986 1 a2986 1 Tasks::); using more than one of the 'inferior', 'thread', or 'task' d2996 1 a2996 1 program may have more than one "thread" of execution. The precise d3006 4 a3009 4 * automatic notification of new threads * 'thread THREAD-ID', a command to switch among threads * 'info threads', a command to inquire about existing threads * 'thread apply [THREAD-ID-LIST | all] ARGS', a command to apply a d3011 2 a3012 2 * thread-specific breakpoints * 'set print thread-events', which controls printing of messages on d3014 2 a3015 2 * 'set libthread-db-search-path PATH', which lets the user specify which 'libthread_db' to use if the default choice isn't compatible d3021 1 a3021 1 "current thread". Debugging commands show program information from the d3026 1 a3026 1 '[New SYSTAG]', where SYSTAG is a thread identifier whose form varies d3033 1 a3033 1 SYSTAG is simply something like 'process 368', with no further d3042 1 a3042 1 INFERIOR-NUM.THREAD-NUM syntax, also known as "qualified thread ID", d3044 1 a3044 1 thread number of the given inferior. For example, thread '2.3' refers d3046 1 a3046 1 'thread 3'), then GDB infers you're referring to a thread of the current d3054 1 a3054 1 Some commands accept a space-separated "thread ID list" as argument. d3057 3 a3059 3 1. A thread ID as shown in the first field of the 'info threads' display, with or without an inferior qualifier. E.g., '2.1' or '1'. d3062 2 a3063 2 qualifier, as in INF.THR1-THR2 or THR1-THR2. E.g., '1.2-4' or '2-4'. d3066 1 a3066 1 without an inferior qualifier, as in INF.'*' (e.g., '1.*') or '*'. d3072 1 a3072 1 thread with ID 7.1, the thread list '1 2-3 4.5 6.7-9 7.*' includes d3075 1 a3075 1 qualified form, the same as '1.1 1.2 1.3 4.5 6.7 6.8 6.9 7.1'. d3078 1 a3078 1 a unique _global_ number, also known as "global thread ID", a single d3087 1 a3087 1 The debugger convenience variables '$_thread' and '$_gthread' d3091 1 a3091 1 forth. The convenience variable '$_inferior_thread_count' contains the d3098 1 a3098 1 '$_inferior_thread_count' could return a different value each time it is d3111 1 a3111 1 'info threads [-gid] [THREAD-ID-LIST]' d3122 1 a3122 1 2. the global thread number assigned by GDB, if the '-gid' option d3128 1 a3128 1 named by the user (see 'thread name', below), or, in some d3133 1 a3133 1 An asterisk '*' to the left of the GDB thread number indicates the d3149 1 a3149 1 If you specify the '-gid' option, GDB displays a column indicating d3162 1 a3162 1 'maint info sol-threads' d3165 1 a3165 1 'thread THREAD-ID' d3168 2 a3169 2 'info threads' display, with or without an inferior qualifier (e.g., '2.1' or '1'). d3179 2 a3180 2 As with the '[New ...]' message, the form of the text after 'Switching to' depends on your system's conventions for identifying d3183 2 a3184 2 'thread apply [THREAD-ID-LIST | all [-ascending]] [FLAG]... COMMAND' The 'thread apply' command allows you to apply the named COMMAND to d3187 4 a3190 4 specify 'all' to apply to all threads. To apply a command to all threads in descending order, type 'thread apply all COMMAND'. To apply a command to all threads in ascending order, type 'thread apply all -ascending COMMAND'. d3194 3 a3196 3 with a '-' directly followed by one letter in 'qcs'. If several flags are provided, they must be given individually, such as '-c -q'. d3200 1 a3200 1 COMMAND will abort 'thread apply'. The following flags can be used d3203 6 a3208 6 '-c' The flag '-c', which stands for 'continue', causes any errors in COMMAND to be displayed, and the execution of 'thread apply' then continues. '-s' The flag '-s', which stands for 'silent', causes any errors or d3212 2 a3213 2 '-q' The flag '-q' ('quiet') disables printing the thread d3216 1 a3216 1 Flags '-c' and '-s' cannot be used together. d3218 2 a3219 2 'taas [OPTION]... COMMAND' Shortcut for 'thread apply all -s [OPTION]... COMMAND'. Applies d3222 2 a3223 2 The 'taas' command accepts the same options as the 'thread apply all' command. *Note thread apply all::. d3225 8 a3232 8 'tfaas [OPTION]... COMMAND' Shortcut for 'thread apply all -s -- frame apply all -s [OPTION]... COMMAND'. Applies COMMAND on all frames of all threads, ignoring errors and empty output. Note that the flag '-s' is specified twice: The first '-s' ensures that 'thread apply' only shows the thread information of the threads for which 'frame apply' produces some output. The second '-s' is needed to ensure that 'frame apply' shows the frame information of a frame only if the COMMAND d3240 1 a3240 1 The 'tfaas' command accepts the same options as the 'frame apply' d3243 1 a3243 1 'thread name [NAME]' d3246 1 a3246 1 name appears in the 'info threads' display. d3250 1 a3250 1 specified with 'thread name' will override the system-give name, d3254 1 a3254 1 'thread find [REGEXP]' d3258 1 a3258 1 As well as being the complement to the 'thread name' command, this d3268 4 a3271 4 'set print thread-events' 'set print thread-events on' 'set print thread-events off' The 'set print thread-events' command allows you to enable or d3278 1 a3278 1 'show print thread-events' d3289 1 a3289 1 'set libthread-db-search-path [PATH]' d3291 4 a3294 4 directories GDB will use to search for 'libthread_db'. If you omit PATH, 'libthread-db-search-path' will be reset to its default value ('$sdir:$pdir' on GNU/Linux and Solaris systems). Internally, the default value comes from the 'LIBTHREAD_DB_SEARCH_PATH' macro. d3297 5 a3301 5 'libthread_db' library to obtain information about threads in the inferior process. GDB will use 'libthread-db-search-path' to find 'libthread_db'. GDB also consults first if inferior specific thread debugging library loading is enabled by 'set auto-load libthread-db' (*note libthread_db.so.1 file::). d3303 1 a3303 1 A special entry '$sdir' for 'libthread-db-search-path' refers to d3305 2 a3306 2 loading shared libraries. The '$sdir' entry is the only kind not needing to be enabled by 'set auto-load libthread-db' (*note d3309 2 a3310 2 A special entry '$pdir' for 'libthread-db-search-path' refers to the directory from which 'libpthread' was loaded in the inferior d3313 1 a3313 1 For any 'libthread_db' library GDB finds in above directories, GDB d3316 3 a3318 3 mismatch between 'libthread_db' and 'libpthread'), GDB will unload 'libthread_db', and continue with the next directory. If none of 'libthread_db' libraries initialize successfully, GDB will issue a d3321 1 a3321 1 Setting 'libthread-db-search-path' is currently implemented only on d3324 1 a3324 1 'show libthread-db-search-path' d3327 8 a3334 8 'set debug libthread-db' 'show debug libthread-db' Turns on or off display of 'libthread_db'-related events. Use '1' to enable, '0' to disable. 'set debug threads [on|off]' 'show debug threads' When 'on' GDB will print additional messages when threads are d3344 1 a3344 1 create additional processes using the 'fork' function. When a program d3347 1 a3347 1 which the child then executes, the child will get a 'SIGTRAP' signal d3351 1 a3351 1 which isn't too painful. Put a call to 'sleep' in the code which the d3355 1 a3355 1 child. While the child is sleeping, use the 'ps' program to get its d3362 1 a3362 1 create additional processes using the 'fork' or 'vfork' functions. On d3367 2 a3368 2 connected to 'gdbserver' in either 'target remote' mode or 'target extended-remote' mode. d3374 1 a3374 1 process, use the command 'set follow-fork-mode'. d3376 3 a3378 3 'set follow-fork-mode MODE' Set the debugger response to a program call of 'fork' or 'vfork'. A call to 'fork' or 'vfork' creates a new process. The MODE d3381 1 a3381 1 'parent' d3385 1 a3385 1 'child' d3389 2 a3390 2 'show follow-fork-mode' Display the current debugger response to a 'fork' or 'vfork' call. d3393 1 a3393 1 use the command 'set detach-on-fork'. d3395 1 a3395 1 'set detach-on-fork MODE' d3399 1 a3399 1 'on' d3401 1 a3401 1 of 'follow-fork-mode') will be detached and allowed to run d3404 1 a3404 1 'off' d3407 1 a3407 1 'follow-fork-mode') is debugged as usual, while the other is d3410 1 a3410 1 'show detach-on-fork' d3413 1 a3413 1 If you choose to set 'detach-on-fork' mode off, then GDB will retain d3416 2 a3417 2 'info inferiors' command, and switch from one fork to another by using the 'inferior' command (*note Debugging Multiple Inferiors Connections d3421 2 a3422 2 from it by using the 'detach inferiors' command (allowing it to run independently), or kill it using the 'kill inferiors' command. *Note d3426 4 a3429 4 If you ask to debug a child process and a 'vfork' is followed by an 'exec', GDB executes the new target up to the first breakpoint in the new target. If you have a breakpoint set on 'main' in your original program, the breakpoint will also be set on the child process's 'main'. d3431 2 a3432 2 On some systems, when a child process is spawned by 'vfork', you cannot debug the child or parent until an 'exec' call completes. d3434 2 a3435 2 If you issue a 'run' command to GDB after an 'exec' call executes, the new target restarts. To restart the parent process, use the 'file' d3437 1 a3437 1 after an 'exec' call executes, GDB discards the symbols of the previous d3439 1 a3439 1 'set follow-exec-mode' command. d3441 1 a3441 1 'set follow-exec-mode MODE' d3443 1 a3443 1 Set debugger response to a program call of 'exec'. An 'exec' call d3446 1 a3446 1 'follow-exec-mode' can be: d3448 1 a3448 1 'new' d3451 1 a3451 1 'exec' call can be restarted afterwards by restarting the d3468 1 a3468 1 'same' d3471 3 a3473 3 the inferior. Restarting the inferior after the 'exec' call, with e.g., the 'run' command, restarts the executable the process was running after the 'exec' call. This is the d3488 2 a3489 2 'follow-exec-mode' is supported in native mode and 'target extended-remote' mode. d3491 2 a3492 2 You can use the 'catch' command to make GDB stop whenever a 'fork', 'vfork', or 'exec' call is made. *Note Setting Catchpoints: Set d3501 2 a3502 2 On certain operating systems(1), GDB is able to save a "snapshot" of a program's state, called a "checkpoint", and come back to it later. d3505 1 a3505 1 happened in the program since the 'checkpoint' was saved. This includes d3519 1 a3519 1 To use the 'checkpoint'/'restart' method of debugging: d3521 1 a3521 1 'checkpoint' d3523 1 a3523 1 The 'checkpoint' command takes no arguments, but each checkpoint is d3526 1 a3526 1 'info checkpoints' d3531 4 a3534 4 'Checkpoint ID' 'Process ID' 'Code Address' 'Source line, or label' d3536 1 a3536 1 'restart CHECKPOINT-ID' d3548 1 a3548 1 'delete checkpoint CHECKPOINT-ID' d3608 1 a3608 1 as 'step'. You may then examine and change variables, set new d3614 1 a3614 1 'info program' d3634 1 a3634 1 A "breakpoint" makes your program stop whenever a certain point in the d3637 1 a3637 1 breakpoints with the 'break' command and its variants (*note Setting d3645 1 a3645 1 A "watchpoint" is a special breakpoint that stops your program when d3648 2 a3649 2 by operators, such as 'a + b'. This is sometimes called "data breakpoints". You must use a different command to set watchpoints d3658 1 a3658 1 A "catchpoint" is another special breakpoint that stops your program d3664 1 a3664 1 'handle' command; see *note Signals: Signals.) d3670 1 a3670 1 want to change. Each breakpoint may be "enabled" or "disabled"; if d3675 1 a3675 1 number, like '5', or a range of such numbers, like '5-7'. When a d3700 2 a3701 2 Breakpoints are set with the 'break' command (abbreviated 'b'). The debugger convenience variable '$bpnum' records the number of the d3719 1 a3719 1 '$_hit_bpnum' and '$_hit_locno' are respectively set to the number of d3730 2 a3731 2 Note that '$_hit_bpnum' and '$bpnum' are not equivalent: '$_hit_bpnum' is set to the breakpoint number last hit, while '$bpnum' d3735 1 a3735 1 '$_hit_locno' is set to 1: d3744 1 a3744 1 The '$_hit_bpnum' and '$_hit_locno' variables can typically be used d3747 5 a3751 5 can disable completely the encountered breakpoint using 'disable $_hit_bpnum' or disable the specific encountered breakpoint location using 'disable $_hit_bpnum.$_hit_locno'. If a breakpoint has only one location, '$_hit_locno' is set to 1 and the commands 'disable $_hit_bpnum' and 'disable $_hit_bpnum.$_hit_locno' both disable the d3759 1 a3759 1 'break LOCSPEC' d3779 2 a3780 2 'break' When called without any arguments, 'break' sets a breakpoint at the d3784 3 a3786 3 to that frame. This is similar to the effect of a 'finish' command in the frame inside the selected frame--except that 'finish' does not leave an active breakpoint. If you use 'break' without an d3796 1 a3796 1 'break ... if COND' d3799 1 a3799 1 nonzero--that is, if COND evaluates as true. '...' stands for one d3818 1 a3818 1 an uppercase 'N' in the output of the 'info breakpoints' command: d3831 1 a3831 1 breakpoint. For example, if variable 'foo' is an undefined d3837 1 a3837 1 'break ... -force-condition if COND' d3841 1 a3841 1 cases, by using the '-force-condition' keyword before 'if', GDB can d3857 1 a3857 1 valid, the '-force-condition' keyword has no effect. d3859 1 a3859 1 'tbreak ARGS' d3861 1 a3861 1 as for the 'break' command, and the breakpoint is set in the same d3866 1 a3866 1 'hbreak ARGS' d3868 1 a3868 1 the 'break' command and the breakpoint is set in the same way, but d3885 1 a3885 1 'thbreak ARGS' d3887 2 a3888 2 ARGS are the same as for the 'hbreak' command and the breakpoint is set in the same way. However, like the 'tbreak' command, the d3890 1 a3890 1 program stops there. Also, like the 'hbreak' command, the d3895 1 a3895 1 'rbreak REGEX' d3900 1 a3900 1 with the 'break' command. You can delete them, disable them, or d3904 2 a3905 2 print the list of all breakpoints it sets according to the 'set language' value: using 'set language auto' (see *note Set Language d3911 6 a3916 6 tools like 'grep'. Note that this is different from the syntax used by shells, so for instance 'foo*' matches all functions that include an 'fo' followed by zero or more 'o's. There is an implicit '.*' leading and trailing the regular expression you supply, so to match only functions that begin with 'foo', use '^foo'. d3918 1 a3918 1 When debugging C++ programs, 'rbreak' is useful for setting d3922 1 a3922 1 The 'rbreak' command can be used to set breakpoints in *all* the d3927 2 a3928 2 'rbreak FILE:REGEX' If 'rbreak' is called with a filename qualification, it limits the d3938 2 a3939 2 'info breakpoints [LIST...]' 'info break [LIST...]' d3953 1 a3953 1 Enabled breakpoints are marked with 'y'. 'n' marks d3958 1 a3958 1 field will contain ''. Such breakpoint won't fire d3961 1 a3961 1 with several locations will have '' in this d3973 1 a3973 1 then the condition is evaluated by the target. The 'info break' d3984 3 a3986 3 'info break' with a breakpoint number N as argument lists only that breakpoint. The convenience variable '$_' and the default examining-address for the 'x' command are set to the address of the d3989 1 a3989 1 'info break' displays a count of the number of times the breakpoint d3991 1 a3991 1 'ignore' command. You can ignore a large number of breakpoint d3997 2 a3998 2 For a breakpoints with an enable count (xref) greater than 1, 'info break' also displays that count. d4011 1 a4011 1 for each code location. The header row has '' in the address d4027 2 a4028 2 passing BREAKPOINT-NUMBER.LOCATION-NUMBER as argument to the 'enable' and 'disable' commands. It's also possible to 'enable' and 'disable' a d4031 1 a4031 1 'BREAKPOINT-NUMBER.LOCATION-NUMBER1-LOCATION-NUMBER2', in which case GDB d4037 1 a4037 1 won't trigger a break, and are denoted by 'y-' in the 'Enb' column. For d4055 1 a4055 1 "pending breakpoint"--breakpoint whose address is not yet resolved. d4074 1 a4074 1 when the 'break' command cannot resolve the location spec to any code d4077 1 a4077 1 'set breakpoint pending auto' d4082 1 a4082 1 'set breakpoint pending on' d4086 1 a4086 1 'set breakpoint pending off' d4092 1 a4092 1 'show breakpoint pending' d4095 1 a4095 1 The settings above only affect the 'break' command and its variants. d4102 2 a4103 2 with the 'break' command as well as to internal breakpoints set by commands like 'next' and 'finish'. For breakpoints set with 'hbreak', d4108 1 a4108 1 'set breakpoint auto-hw on' d4113 1 a4113 1 'set breakpoint auto-hw off' d4128 1 a4128 1 'set breakpoint always-inserted off' d4133 1 a4133 1 'set breakpoint always-inserted on' d4149 1 a4149 1 'set breakpoint condition-evaluation host' d4155 1 a4155 1 'set breakpoint condition-evaluation target' d4169 1 a4169 1 'set breakpoint condition-evaluation auto' d4178 4 a4181 4 purposes, such as proper handling of 'longjmp' (in C programs). These internal breakpoints are assigned negative numbers, starting with '-1'; 'info breakpoints' does not display them. You can see these breakpoints with the GDB maintenance command 'maint info breakpoints' (*note maint d4192 1 a4192 1 this may happen. (This is sometimes called a "data breakpoint".) The d4196 1 a4196 1 * A reference to the value of a single variable. d4198 3 a4200 3 * An address cast to an appropriate data type. For example, '*(int *)0x12345678' will watch a 4-byte region at the specified address (assuming an 'int' occupies 4 bytes). d4202 1 a4202 1 * An arbitrarily complex expression, such as 'a*b + c/d'. The d4208 2 a4209 2 '*global_ptr' before 'global_ptr' is initialized. GDB will stop when your program sets 'global_ptr' and the expression produces a valid d4211 2 a4212 2 a variable (e.g. if the memory pointed to by '*global_ptr' becomes readable as the result of a 'malloc' call), GDB may not stop until the d4226 1 a4226 1 'watch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE] [task TASK-ID]' d4234 1 a4234 1 If the command includes a '[thread THREAD-ID]' argument, GDB breaks d4240 1 a4240 1 Similarly, if the 'task' argument is given, then the watchpoint d4244 1 a4244 1 (see below). The '-location' argument tells GDB to instead watch d4251 1 a4251 1 The '[mask MASKVALUE]' argument allows creation of masked d4254 1 a4254 1 Embedded::.) A "masked watchpoint" specifies a mask in addition to d4261 1 a4261 1 'mask' argument implies '-location'. Examples: d4266 1 a4266 1 'rwatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]' d4270 1 a4270 1 'awatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]' d4274 1 a4274 1 'info watchpoints [LIST...]' d4276 1 a4276 1 'info break' (*note Set Breaks::). d4288 1 a4288 1 GDB sets a "hardware watchpoint" if possible. Hardware watchpoints d4295 2 a4296 2 You can force GDB to use only software watchpoints with the 'set can-use-hw-watchpoints 0' command. With this variable set to zero, GDB d4299 1 a4299 1 were set _before_ setting 'can-use-hw-watchpoints' to zero will still d4302 1 a4302 1 'set can-use-hw-watchpoints' d4305 1 a4305 1 'show can-use-hw-watchpoints' d4312 1 a4312 1 When you issue the 'watch' command, GDB reports d4318 1 a4318 1 Currently, the 'awatch' and 'rwatch' commands can only set hardware d4323 1 a4323 1 'awatch' or 'rwatch' command, it will print a message like this: d4352 1 a4352 1 If you call a function interactively using 'print' or 'call', any d4363 1 a4363 1 doing that would be to set a code breakpoint at the entry to the 'main' d4387 1 a4387 1 You can use "catchpoints" to cause the debugger to stop for certain d4389 1 a4389 1 shared library. Use the 'catch' command to set a catchpoint. d4391 1 a4391 1 'catch EVENT' d4394 3 a4396 3 'throw [REGEXP]' 'rethrow [REGEXP]' 'catch [REGEXP]' d4402 1 a4402 1 The convenience variable '$_exception' is available at an d4409 2 a4410 2 * The support for these commands is system-dependent. Currently, only systems using the 'gnu-v3' C++ ABI (*note d4413 1 a4413 1 * The regular expression feature and the '$_exception' d4415 1 a4415 1 probes in 'libstdc++'. If these probes are not present, d4421 1 a4421 1 * The '$_exception' convenience variable is only valid at d4425 1 a4425 1 * When an exception-related catchpoint is hit, GDB stops at d4427 2 a4428 2 exception support for C++, usually 'libstdc++'. You can use 'up' (*note Selection::) to get to your code. d4430 1 a4430 1 * If you call a function interactively, GDB normally d4440 1 a4440 1 this with 'set unwind-on-terminating-exception'. d4442 1 a4442 1 * You cannot raise an exception interactively. d4444 1 a4444 1 * You cannot install an exception handler interactively. d4446 1 a4446 1 'exception [NAME]' d4448 2 a4449 2 specified at the end of the command (eg 'catch exception Program_Error'), the debugger will stop only when this d4459 3 a4461 3 'Constraint_Error' is defined in package 'Pck', then the command to use to catch such exceptions is 'catch exception Pck.Constraint_Error'. d4463 1 a4463 1 The convenience variable '$_ada_exception' holds the address d4467 1 a4467 1 'exception unhandled' d4469 2 a4470 2 program. The convenience variable '$_ada_exception' is set as for 'catch exception'. d4472 1 a4472 1 'handlers [NAME]' d4474 2 a4475 2 specified at the end of the command (eg 'catch handlers Program_Error'), the debugger will stop only when this d4485 3 a4487 3 'Constraint_Error' is defined in package 'Pck', then the command to use to catch such exceptions handling is 'catch handlers Pck.Constraint_Error'. d4489 2 a4490 2 The convenience variable '$_ada_exception' is set as for 'catch exception'. d4492 1 a4492 1 'assert' d4494 1 a4494 1 '$_ada_exception' is _not_ set by this catchpoint. d4496 2 a4497 2 'exec' A call to 'exec'. d4499 3 a4501 3 'syscall' 'syscall [NAME | NUMBER | group:GROUPNAME | g:GROUPNAME] ...' A call to or return from a system call, a.k.a. "syscall". A d4512 1 a4512 1 syscall names on '/usr/include/asm/unistd.h'. d4529 1 a4529 1 once using the 'group:' syntax ('g:' is a shorter equivalent). d4532 1 a4532 1 'group:network' to 'catch syscall'. Note that not all syscall d4613 1 a4613 1 If you configure GDB using the '--without-expat' option, it d4641 2 a4642 2 'fork' A call to 'fork'. d4644 2 a4645 2 'vfork' A call to 'vfork'. d4647 2 a4648 2 'load [REGEXP]' 'unload [REGEXP]' d4653 1 a4653 1 'signal [SIGNAL... | 'all']' d4658 1 a4658 1 except 'SIGTRAP' and 'SIGINT'. d4660 1 a4660 1 With the argument 'all', all signals, including those used by d4665 1 a4665 1 to 'handle' (*note Signals::). Only signals specified in this d4668 2 a4669 2 One reason that 'catch signal' can be more useful than 'handle' is that you can attach commands and conditions to the d4672 2 a4673 2 When a signal is caught by a catchpoint, the signal's 'stop' and 'print' settings, as specified by 'handle', are ignored. d4675 1 a4675 1 depends on the 'pass' setting; this can be changed in the d4678 1 a4678 1 'tcatch EVENT' d4682 1 a4682 1 Use the 'info break' command to list the current catchpoints. d4692 1 a4692 1 to stop there. This is called "deleting" the breakpoint. A breakpoint d4695 2 a4696 2 With the 'clear' command you can delete breakpoints according to where they are in your program. With the 'delete' command you can d4705 1 a4705 1 'clear' d4711 1 a4711 1 'clear LOCSPEC' d4717 4 a4720 4 'LINENUM' 'FILENAME:LINENUM' '-line LINENUM' '-source FILENAME -line LINENUM' d4727 1 a4727 1 '*ADDRESS' d4731 2 a4732 2 'FUNCTION' '-function FUNCTION' d4740 1 a4740 1 'delete [breakpoints] [LIST...]' d4744 2 a4745 2 catchpoints (GDB asks confirmation, unless you have 'set confirm off'). You can abbreviate this command as 'd'. d4754 1 a4754 1 prefer to "disable" it. This makes the breakpoint inoperative as if it d4756 1 a4756 1 that you can "enable" it again later. d4759 3 a4761 3 catchpoints with the 'enable' and 'disable' commands, optionally specifying one or more breakpoint numbers as arguments. Use 'info break' to print a list of all breakpoints, watchpoints, tracepoints, and d4770 4 a4773 4 * Enabled. The breakpoint stops your program. A breakpoint set with the 'break' command starts out in this state. * Disabled. The breakpoint has no effect on your program. * Enabled once. The breakpoint stops your program, but then becomes d4775 1 a4775 1 * Enabled for a count. The breakpoint stops your program for the d4777 1 a4777 1 * Enabled for deletion. The breakpoint stops your program, but d4779 1 a4779 1 breakpoint set with the 'tbreak' command starts out in this state. d4784 1 a4784 1 'disable [breakpoints] [LIST...]' d4789 1 a4789 1 abbreviate 'disable' as 'dis'. d4791 1 a4791 1 'enable [breakpoints] [LIST...]' d4795 1 a4795 1 'enable [breakpoints] once LIST...' d4799 1 a4799 1 'enable [breakpoints] count COUNT LIST...' d4807 1 a4807 1 'enable [breakpoints] delete LIST...' d4810 1 a4810 1 there. Breakpoints set by the 'tbreak' command start out in this d4813 1 a4813 1 Except for a breakpoint set with 'tbreak' (*note Setting Breakpoints: d4816 1 a4816 1 the commands above. (The command 'until' can set and delete a d4828 1 a4828 1 specified place. You can also specify a "condition" for a breakpoint. d4837 2 a4838 2 expressed by the condition ASSERT, you should set the condition '! ASSERT' on the appropriate breakpoint. d4871 1 a4871 1 'if' in the arguments to the 'break' command. *Note Setting d4873 1 a4873 1 'condition' command. d4875 2 a4876 2 You can also use the 'if' keyword with the 'watch' command. The 'catch' command does not recognize the 'if' keyword; 'condition' is the d4879 1 a4879 1 'condition BNUM EXPRESSION' d4883 1 a4883 1 is true (nonzero, in C). When you use 'condition', GDB checks d4892 2 a4893 2 'condition' command (or a command that sets a breakpoint with a condition, like 'break if ...') is given, however. *Note d4896 2 a4897 2 'condition -force BNUM EXPRESSION' When the '-force' flag is used, define the condition even if d4899 2 a4900 2 BNUM. This is similar to the '-force-condition' option of the 'break' command. d4902 1 a4902 1 'condition BNUM' d4908 1 a4908 1 useful that there is a special way to do it, using the "ignore count" of d4917 1 a4917 1 'ignore BNUM COUNT' d4926 1 a4926 1 When you use 'continue' to resume execution of your program from a d4928 1 a4928 1 to 'continue', rather than using 'ignore'. *Note Continuing and d4936 1 a4936 1 such as '$foo-- <= 0' using a debugger convenience variable that is d4954 3 a4956 3 'commands [LIST...]' '... COMMAND-LIST ...' 'end' d4959 1 a4959 1 just 'end' to terminate the commands. d4961 2 a4962 2 To remove all commands from a breakpoint, type 'commands' and follow it immediately with 'end'; that is, give no commands. d4964 1 a4964 1 With no argument, 'commands' refers to the last breakpoint, d4967 1 a4967 1 single command, then the 'commands' will apply to all the d4969 1 a4969 1 by 'rbreak', and also applies when a single 'break' command creates d4976 1 a4976 1 Inside a command list, you can use the command 'disable $_hit_bpnum' d4979 2 a4980 2 If your breakpoint has several code locations, the command 'disable $_hit_bpnum.$_hit_locno' will disable the specific breakpoint code d4985 1 a4985 1 Simply use the 'continue' command, or 'step', or any other command that d4990 1 a4990 1 (even with a simple 'next' or 'step'), you may encounter another d4994 1 a4994 1 If the first command you specify in a command list is 'silent', the d4998 1 a4998 1 see no sign that the breakpoint was reached. 'silent' is meaningful d5001 1 a5001 1 The commands 'echo', 'output', and 'printf' allow you to print d5006 1 a5006 1 the value of 'x' at entry to 'foo' whenever 'x' is positive. d5019 2 a5020 2 to any variables that need them. End with the 'continue' command so that your program does not stop, and start with the 'silent' command so d5036 1 a5036 1 The dynamic printf command 'dprintf' combines a breakpoint with d5038 1 a5038 1 inserting 'printf' calls into your program on-the-fly, without having to d5042 1 a5042 1 you can set the variable 'dprintf-style' for alternate handling. For d5044 1 a5044 1 'printf' function. This has the advantage that the characters go to the d5056 1 a5056 1 'dprintf LOCSPEC,TEMPLATE,EXPRESSION[,EXPRESSION...]' d5062 1 a5062 1 'set dprintf-style STYLE' d5069 3 a5071 3 'gdb' Handle the output using the GDB 'printf' command. When using this style, it is possible to use the '%V' format specifier d5074 1 a5074 1 'call' d5076 1 a5076 1 (normally 'printf'). When using this style the supported d5081 2 a5082 2 the 'printf' function, however, GDB's '%V' format specifier extension is not supported by 'printf'. When using 'call' d5087 2 a5088 2 'agent' Have the remote debugging agent (such as 'gdbserver') handle d5091 1 a5091 1 not support the '%V' format specifier. d5093 4 a5096 4 'set dprintf-function FUNCTION' Set the function to call if the dprintf style is 'call'. By default its value is 'printf'. You may set it to any expression that GDB can evaluate to a function, as per the 'call' command. d5098 1 a5098 1 'set dprintf-channel CHANNEL' d5101 1 a5101 1 argument to the 'dprintf-function', in the manner of 'fprintf' and d5103 1 a5103 1 the first argument, in the manner of 'printf'. d5105 2 a5106 2 As an example, if you wanted 'dprintf' output to go to a logfile that is a standard I/O stream assigned to the variable 'mylog', you d5120 1 a5120 1 Note that the 'info break' displays the dynamic printf commands as d5124 3 a5126 3 'set disconnected-dprintf on' 'set disconnected-dprintf off' Choose whether 'dprintf' commands should continue to run if GDB has d5128 1 a5128 1 'dprintf-style' is 'agent'. d5130 2 a5131 2 'show disconnected-dprintf off' Show the current choice for disconnected 'dprintf'. d5146 1 a5146 1 To save breakpoint definitions to a file use the 'save breakpoints' d5149 1 a5149 1 'save breakpoints [FILENAME]' d5151 1 a5151 1 their commands and ignore counts, into a file 'FILENAME' suitable d5154 1 a5154 1 To read the saved breakpoint definitions, use the 'source' command d5170 1 a5170 1 GDB supports "SDT" probes in the code. SDT stands for Statically d5177 2 a5178 2 * 'SystemTap' () SDT probes(1). 'SystemTap' probes are usable from assembly, C and C++ d5181 2 a5182 2 * 'DTrace' () USDT probes. 'DTrace' probes are usable from C and C++ languages. d5184 1 a5184 1 Some 'SystemTap' probes have an associated semaphore variable; for d5186 1 a5186 1 DTrace-style '.d' file. If your probe has a semaphore, GDB will d5188 3 a5190 3 '-probe-stap' notation. But, if you put a breakpoint at a probe's location by some other method (e.g., 'break file:line'), then GDB will not automatically set the semaphore. 'DTrace' probes do not support d5193 2 a5194 2 You can examine the available static static probes using 'info probes', with optional arguments: d5196 3 a5198 3 'info probes [TYPE] [PROVIDER [NAME [OBJFILE]]]' If given, TYPE is either 'stap' for listing 'SystemTap' probes or 'dtrace' for listing 'DTrace' probes. If omitted all probes are d5213 1 a5213 1 'info probes all' d5218 2 a5219 2 handled. Some 'DTrace' probes can be enabled or disabled, but 'SystemTap' probes cannot be disabled. d5224 1 a5224 1 'enable probes [PROVIDER [NAME [OBJFILE]]]' d5237 2 a5238 2 'disable probes [PROVIDER [NAME [OBJFILE]]]' See the 'enable probes' command above for a description of the d5245 1 a5245 1 '$_probe_arg0'...'$_probe_arg11'. In 'SystemTap' probes each probe d5247 1 a5247 1 In 'DTrace' probes types are preserved provided that they are recognized d5249 1 a5249 1 integer. The convenience variable '$_probe_argc' holds the number of d5260 1 a5260 1 more information on how to add 'SystemTap' SDT probes in your d5341 2 a5342 2 "Continuing" means resuming program execution until your program completes normally. In contrast, "stepping" means executing just one d5347 1 a5347 1 to a signal, you may want to use 'handle', or use 'signal 0' to resume d5351 3 a5353 3 'continue [IGNORE-COUNT]' 'c [IGNORE-COUNT]' 'fg [IGNORE-COUNT]' d5358 1 a5358 1 is like that of 'ignore' (*note Break Conditions: Conditions.). d5362 1 a5362 1 'continue' is ignored. d5364 1 a5364 1 The synonyms 'c' and 'fg' (for "foreground", as the debugged d5366 1 a5366 1 for convenience, and have exactly the same behavior as 'continue'. d5368 1 a5368 1 To resume execution at a different place, you can use 'return' (*note d5370 1 a5370 1 function; or 'jump' (*note Continuing at a Different Address: Jumping.) d5380 1 a5380 1 'step' d5383 1 a5383 1 is abbreviated 's'. d5385 1 a5385 1 _Warning:_ If you use the 'step' command while control is d5391 1 a5391 1 debugging information, use the 'stepi' command, described d5394 1 a5394 1 The 'step' command only stops at the first instruction of a source d5396 1 a5396 1 in 'switch' statements, 'for' loops, etc. 'step' continues to stop d5398 1 a5398 1 line. In other words, 'step' _steps inside_ any functions called d5401 1 a5401 1 Also, the 'step' command only enters a function if there is line d5403 2 a5404 2 'next' command. This avoids problems when using 'cc -gl' on MIPS machines. Previously, 'step' entered subroutines if there was any d5407 2 a5408 2 'step COUNT' Continue running as in 'step', but do so COUNT times. If a d5412 1 a5412 1 'next [COUNT]' d5414 1 a5414 1 frame. This is similar to 'step', but function calls that appear d5417 2 a5418 2 stack level that was executing when you gave the 'next' command. This command is abbreviated 'n'. d5420 1 a5420 1 An argument COUNT is a repeat count, as for 'step'. d5422 1 a5422 1 The 'next' command only stops at the first instruction of a source d5424 1 a5424 1 'switch' statements, 'for' loops, etc. d5426 3 a5428 3 'set step-mode' 'set step-mode on' The 'set step-mode on' command causes the 'step' command to stop at d5436 2 a5437 2 'set step-mode off' Causes the 'step' command to step over any functions which contains d5440 1 a5440 1 'show step-mode' d5444 1 a5444 1 'finish' d5447 1 a5447 1 can be abbreviated as 'fin'. d5449 1 a5449 1 Contrast this with the 'return' command (*note Returning from a d5452 5 a5456 5 'set print finish [on|off]' 'show print finish' By default the 'finish' command will show the value that is returned by the function. This can be disabled using 'set print finish off'. When disabled, the value is still entered into the d5459 2 a5460 2 'until' 'u' d5464 1 a5464 1 'next' command, except that when 'until' encounters a jump, it d5469 2 a5470 2 stepping though it, 'until' makes your program continue execution until it exits the loop. In contrast, a 'next' command at the end d5474 1 a5474 1 'until' always stops your program if it attempts to exit the d5477 1 a5477 1 'until' may produce somewhat counterintuitive results if the order d5479 3 a5481 3 example, in the following excerpt from a debugging session, the 'f' ('frame') command shows that execution is stopped at line '206'; yet when we use 'until', we get to line '195': d5491 2 a5492 2 the start, of the loop--even though the test in a C 'for'-loop is written before the body of the loop. The 'until' command appeared d5497 2 a5498 2 'until' with no argument works by means of single instruction stepping, and hence is slower than 'until' with an argument. d5500 2 a5501 2 'until LOCSPEC' 'u LOCSPEC' d5506 1 a5506 1 breakpoints, and hence is quicker than 'until' without an argument. d5508 1 a5508 1 current frame. This implies that 'until' can be used to skip over d5510 2 a5511 2 the current location is line '96', issuing 'until 99' will execute the program up to line '99' in the same invocation of factorial, d5522 1 a5522 1 'advance LOCSPEC' d5526 2 a5527 2 Location Specifications::. This command is similar to 'until', but 'advance' will not skip over recursive function calls, and the d5531 3 a5533 3 'stepi' 'stepi ARG' 'si' d5537 1 a5537 1 It is often useful to do 'display/i $pc' when stepping by machine d5542 1 a5542 1 An argument is a repeat count, as in 'step'. d5544 3 a5546 3 'nexti' 'nexti ARG' 'ni' d5550 1 a5550 1 An argument is a repeat count, as in 'next'. d5552 3 a5554 3 By default, and if available, GDB makes use of target-assisted "range stepping". In other words, whenever you use a stepping command (e.g., 'step', 'next'), GDB tells the target to step the corresponding range of d5563 2 a5564 2 'set range-stepping' 'show range-stepping' d5567 1 a5567 1 If 'on', and the target supports it, GDB tells the target to step a d5569 2 a5570 2 single-steps. If 'off', GDB always issues single-steps, even if range stepping is supported by the target. The default is 'on'. d5579 1 a5579 1 uninteresting to debug. The 'skip' command lets you tell GDB to skip a d5591 4 a5594 4 Suppose you wish to step into the functions 'foo' and 'bar', but you are not interested in stepping through 'boring'. If you run 'step' at line 103, you'll enter 'boring()', but if you run 'next', you'll step over both 'foo' and 'boring'! d5596 2 a5597 2 One solution is to 'step' into 'boring' and use the 'finish' command to immediately exit it. But this can become tedious if 'boring' is d5600 3 a5602 3 A more flexible solution is to execute 'skip boring'. This instructs GDB never to step into 'boring'. Now when you execute 'step' at line 103, you'll step over 'boring' and directly into 'foo'. d5606 1 a5606 1 matches the function's name, file name or a 'glob'-style pattern that d5610 1 a5610 1 Regular Expressions". See for example 'man 7 regex' on GNU/Linux d5612 3 a5614 3 whatever is provided by the 'regcomp' function of the underlying system. See for example 'man 7 glob' on GNU/Linux systems for a description of 'glob'-style patterns. d5616 2 a5617 2 'skip [OPTIONS]' The basic form of the 'skip' command takes zero or more options d5621 2 a5622 2 '-file FILE' '-fi FILE' d5625 2 a5626 2 '-gfile FILE-GLOB-PATTERN' '-gfi FILE-GLOB-PATTERN' d5632 2 a5633 2 '-function LINESPEC' '-fu LINESPEC' d5638 2 a5639 2 '-rfunction REGEXP' '-rfu REGEXP' d5644 1 a5644 1 there is generally no need to step into C++ 'std::string' d5654 1 a5654 1 destructor in the 'std' namespace you can do: d5661 1 a5661 1 'skip function [LINESPEC]' d5669 2 a5670 2 (If you have a function called 'file' that you want to skip, use 'skip function file'.) d5672 1 a5672 1 'skip file [FILENAME]' d5685 1 a5685 1 'info skip [RANGE]' d5688 1 a5688 1 marked for skipping. 'info skip' prints the following information d5694 2 a5695 2 Enabled skips are marked with 'y'. Disabled skips are marked with 'n'. d5697 2 a5698 2 If the file name is a 'glob' pattern this is 'y'. Otherwise it is 'n'. d5700 2 a5701 2 The name or 'glob' pattern of the file to be skipped. If no file is specified this is ''. d5703 2 a5704 2 If the function name is a 'regular expression' this is 'y'. Otherwise it is 'n'. d5707 1 a5707 1 function is specified this is ''. d5709 1 a5709 1 'skip delete [RANGE]' d5713 1 a5713 1 'skip enable [RANGE]' d5717 1 a5717 1 'skip disable [RANGE]' d5721 1 a5721 1 'set debug skip [on|off]' d5725 1 a5725 1 'show debug skip' d5737 4 a5740 4 kind a name and a number. For example, in Unix 'SIGINT' is the signal a program gets when you type an interrupt character (often 'Ctrl-c'); 'SIGSEGV' is the signal a program gets from referencing a place in memory far away from all the areas in use; 'SIGALRM' occurs when the d5744 3 a5746 3 Some signals, including 'SIGALRM', are a normal part of the functioning of your program. Others, such as 'SIGSEGV', indicate errors; these signals are "fatal" (they kill your program immediately) d5748 1 a5748 1 signal. 'SIGINT' does not indicate an error in your program, but it is d5757 1 a5757 1 'SIGALRM' be silently passed to your program (so as not to interfere d5760 1 a5760 1 settings with the 'handle' command. d5762 2 a5763 2 'info signals' 'info handle' d5768 1 a5768 1 'info signals SIG' d5772 1 a5772 1 'info handle' is an alias for 'info signals'. d5774 1 a5774 1 'catch signal [SIGNAL... | 'all']' d5778 1 a5778 1 'handle SIGNAL [ SIGNAL ... ] [KEYWORDS...]' d5780 4 a5783 4 number of a signal or its name (with or without the 'SIG' at the beginning); a list of signal numbers of the form 'LOW-HIGH'; or the word 'all', meaning all the known signals, except 'SIGINT' and 'SIGTRAP', which are used by GDB. Optional argument KEYWORDS, d5787 1 a5787 1 The keywords allowed by the 'handle' command can be abbreviated. d5790 1 a5790 1 'nostop' d5794 1 a5794 1 'stop' d5796 1 a5796 1 implies the 'print' keyword as well. d5798 1 a5798 1 'print' d5801 1 a5801 1 'noprint' d5803 1 a5803 1 implies the 'nostop' keyword as well. d5805 2 a5806 2 'pass' 'noignore' d5809 1 a5809 1 and not handled. 'pass' and 'noignore' are synonyms. d5811 4 a5814 4 'nopass' 'ignore' GDB should not allow your program to see this signal. 'nopass' and 'ignore' are synonyms. d5818 3 a5820 3 'pass' is in effect for the signal in question _at that time_. In other words, after GDB reports a signal, you can use the 'handle' command with 'pass' or 'nopass' to control whether your program sees that signal when d5823 3 a5825 3 The default is set to 'nostop', 'noprint', 'pass' for non-erroneous signals such as 'SIGALRM', 'SIGWINCH' and 'SIGCHLD', and to 'stop', 'print', 'pass' for the erroneous signals. d5827 1 a5827 1 You can also use the 'signal' command to prevent your program from d5834 1 a5834 1 you can continue with 'signal 0'. *Note Giving your Program a Signal: d5838 2 a5839 2 'handle nostop' and 'handle pass' set arrives while a stepping command (e.g., 'stepi', 'step', 'next') is in progress, GDB lets the signal d5843 1 a5843 1 'handle nostop') from changing the focus of debugging unexpectedly. d5845 1 a5845 1 another signal that has 'handle stop' in effect, or for any other event d5848 1 a5848 1 'handle print' is set. d5850 3 a5852 3 If you set 'handle pass' for a signal, and your program sets up a handler for it, then issuing a stepping command, such as 'step' or 'stepi', when your program is stopped due to the signal will step _into_ d5855 1 a5855 1 Likewise, if you use the 'queue-signal' command to queue a signal to d5860 2 a5861 2 Here's an example, using 'stepi' to step to the first instruction of 'SIGUSR1''s handler: d5876 1 a5876 1 The same, but using 'queue-signal' instead of waiting for the program d5890 1 a5890 1 variable '$_siginfo', and consists of data that is passed by the kernel d5893 3 a5895 3 data type using the 'ptype $_siginfo' command. On Unix systems, it typically corresponds to the standard 'siginfo_t' type, as defined in the 'signal.h' system header. d5926 1 a5926 1 Depending on target support, '$_siginfo' may also be writable. d5928 1 a5928 1 On some targets, a 'SIGSEGV' can be caused by a boundary violation, d5931 1 a5931 1 told to handle the signal. With 'handle stop SIGSEGV', GDB displays the d5933 1 a5933 1 bounds, while with 'handle nostop SIGSEGV' no additional information is d5957 1 a5957 1 default mode, referred to as "all-stop mode", when any thread in your d5960 1 a5960 1 GDB also supports "non-stop mode", in which other threads can continue d5986 1 a5986 1 'step' or 'next'. d6003 1 a6003 1 '[Switching to Thread N]' to identify the thread. d6008 1 a6008 1 'set scheduler-locking MODE' d6012 1 a6012 1 'off' d6015 1 a6015 1 'on' d6020 2 a6021 2 'step' Behaves like 'on' when stepping, and 'off' otherwise. Threads d6024 1 a6024 1 commands like 'continue', 'until', or 'finish'. d6033 2 a6034 2 'replay' Behaves like 'on' in replay mode, and 'off' in either record d6037 1 a6037 1 'show scheduler-locking' d6041 1 a6041 1 'continue', 'next' or 'step', GDB allows only threads of the current d6043 1 a6043 1 with two threads, the 'continue' command resumes only the two threads of d6051 1 a6051 1 'set schedule-multiple' command. d6053 1 a6053 1 'set schedule-multiple' d6055 5 a6059 5 resumed when an execution command is issued. When 'on', all threads of all processes are allowed to run. When 'off', only the threads of the current process are resumed. The default is 'off'. The 'scheduler-locking' mode takes precedence when set to 'on', or while you are stepping and set to 'step'. d6061 1 a6061 1 'show schedule-multiple' d6076 1 a6076 1 external events. This is referred to as "non-stop" mode. d6081 1 a6081 1 commands such as 'continue' and 'step' apply by default only to the d6100 1 a6100 1 'set non-stop on' d6102 1 a6102 1 'set non-stop off' d6104 1 a6104 1 'show non-stop' d6109 1 a6109 1 mode. In particular, the 'set non-stop' preference is only consulted d6116 2 a6117 2 thread by default. That is, 'continue' only continues one thread. To continue all threads, issue 'continue -a' or 'c -a'. d6125 2 a6126 2 Suspending execution is done with the 'interrupt' command when running in the background, or 'Ctrl-c' during foreground execution. In d6129 1 a6129 1 program, use 'interrupt -a'. d6131 1 a6131 1 Other execution commands do not currently support the '-a' option. d6156 3 a6158 3 To specify background execution, add a '&' to the command. For example, the background form of the 'continue' command is 'continue&', or just 'c&'. The execution commands that accept background execution d6161 1 a6161 1 'run' d6164 1 a6164 1 'attach' d6167 1 a6167 1 'step' d6170 1 a6170 1 'stepi' d6173 1 a6173 1 'next' d6176 1 a6176 1 'nexti' d6179 1 a6179 1 'continue' d6182 1 a6182 1 'finish' d6185 1 a6185 1 'until' d6194 1 a6194 1 'help' and 'info break'. d6197 1 a6197 1 by using the 'interrupt' command. d6199 2 a6200 2 'interrupt' 'interrupt -a' d6203 1 a6203 1 'interrupt' stops the whole process, but in non-stop mode, it stops d6205 1 a6205 1 mode, use 'interrupt -a'. d6217 2 a6218 2 'break LOCSPEC thread THREAD-ID' 'break LOCSPEC thread THREAD-ID if ...' d6222 1 a6222 1 Use the qualifier 'thread THREAD-ID' with a breakpoint command to d6226 1 a6226 1 first column of the 'info threads' display. d6228 1 a6228 1 If you do not specify 'thread THREAD-ID' when you set a breakpoint, d6231 2 a6232 2 You can use the 'thread' qualifier on conditional breakpoints as well; in this case, place 'thread THREAD-ID' before or after the d6245 1 a6245 1 thread exit, but also when you detach from the process with the 'detach' d6249 1 a6249 1 the user explicitly asks for the thread list with the 'info threads' d6254 1 a6254 1 Tasks::); using more than one of the 'thread', 'inferior', or 'task' d6278 1 a6278 1 The call to 'sleep' will return early if a different thread stops at d6308 2 a6309 2 When all of these are set to 'off', then GDB is said to be "observer mode". As a convenience, the variable 'observer' can be set to disable d6314 1 a6314 1 'may-insert-breakpoints' but disabled 'may-write-memory', then d6318 5 a6322 5 'set observer on' 'set observer off' When set to 'on', this disables all the permission variables below (except for 'insert-fast-tracepoints'), plus enables non-stop debugging. Setting this to 'off' switches back to normal d6325 1 a6325 1 'show observer' d6328 2 a6329 2 'set may-write-registers on' 'set may-write-registers off' d6331 2 a6332 2 registers, such as with assignment expressions in 'print', or the 'jump' command. It defaults to 'on'. d6334 1 a6334 1 'show may-write-registers' d6337 2 a6338 2 'set may-write-memory on' 'set may-write-memory off' d6340 2 a6341 2 memory, such as with assignment expressions in 'print'. It defaults to 'on'. d6343 1 a6343 1 'show may-write-memory' d6346 2 a6347 2 'set may-insert-breakpoints on' 'set may-insert-breakpoints off' d6350 1 a6350 1 GDB. It defaults to 'on'. d6352 1 a6352 1 'show may-insert-breakpoints' d6355 2 a6356 2 'set may-insert-tracepoints on' 'set may-insert-tracepoints off' d6360 1 a6360 1 of 'may-insert-fast-tracepoints'. It defaults to 'on'. d6362 1 a6362 1 'show may-insert-tracepoints' d6365 2 a6366 2 'set may-insert-fast-tracepoints on' 'set may-insert-fast-tracepoints off' d6370 1 a6370 1 of 'may-insert-tracepoints'. It defaults to 'on'. d6372 1 a6372 1 'show may-insert-fast-tracepoints' d6375 2 a6376 2 'set may-interrupt on' 'set may-interrupt off' d6378 2 a6379 2 execution. When this variable is 'off', the 'interrupt' command will have no effect, nor will 'Ctrl-c'. It defaults to 'on'. d6381 1 a6381 1 'show may-interrupt' d6412 1 a6412 1 activated with the 'record' or 'record btrace' commands. *Note Process d6420 2 a6421 2 'reverse-continue [IGNORE-COUNT]' 'rc [IGNORE-COUNT]' d6427 1 a6427 1 'reverse-step [COUNT]' d6431 1 a6431 1 Like the 'step' command, 'reverse-step' will only stop at the d6434 1 a6434 1 to debuggable functions, 'reverse-step' will step (backward) into d6438 2 a6439 2 Also, as with the 'step' command, if non-debuggable functions are called, 'reverse-step' will run thru them backward without d6442 1 a6442 1 'reverse-stepi [COUNT]' d6446 1 a6446 1 instance, if the last instruction was a jump, 'reverse-stepi' will d6450 1 a6450 1 'reverse-next [COUNT]' d6454 1 a6454 1 the first line of a function, 'reverse-next' will take you back to d6456 1 a6456 1 as the normal 'next' command would take you from the last line of a d6459 2 a6460 2 'reverse-nexti [COUNT]' Like 'nexti', 'reverse-nexti' executes a single instruction in d6463 1 a6463 1 another function, 'reverse-nexti' will continue to execute in d6467 3 a6469 3 'reverse-finish' Just as the 'finish' command takes you to the point where the current function returns, 'reverse-finish' takes you to the point d6473 1 a6473 1 'set exec-direction' d6475 1 a6475 1 'set exec-direction reverse' d6478 3 a6480 3 include 'step, stepi, next, nexti, continue, and finish'. The 'return' command cannot be used in reverse mode. 'set exec-direction forward' d6506 1 a6506 1 On some platforms, GDB provides a special "process record and replay" d6511 1 a6511 1 for the next instruction, GDB will debug in "replay mode". In the d6520 1 a6520 1 GDB will debug in "record mode". In this mode, the inferior executes d6538 1 a6538 1 debugging, and when remote debugging via 'gdbserver'. d6543 1 a6543 1 'record METHOD' d6546 1 a6546 1 parameter the command uses the 'full' recording method. The d6549 1 a6549 1 'full' d6554 1 a6554 1 'btrace FORMAT' d6562 2 a6563 2 reconnecting. The recording may be stopped using 'record stop'. d6569 2 a6570 2 'bts' Use the "Branch Trace Store" (BTS) recording format. In d6574 2 a6575 2 'pt' Use the "Intel Processor Trace" recording format. In d6593 2 a6594 2 with the 'run' or 'start' commands, and then start the recording with the 'record METHOD' command. d6603 1 a6603 1 not all recording methods are available. The 'full' recording d6606 1 a6606 1 'record stop' d6629 1 a6629 1 'record goto' d6633 2 a6634 2 'record goto begin' 'record goto start' d6637 1 a6637 1 'record goto end' d6640 1 a6640 1 'record goto N' d6643 3 a6645 3 'record save FILENAME' Save the execution log to a file 'FILENAME'. Default filename is 'gdb_record.PROCESS_ID', where PROCESS_ID is the process ID of the d6650 7 a6656 7 'record restore FILENAME' Restore the execution log from a file 'FILENAME'. File must have been created with 'record save'. 'set record full insn-number-max LIMIT' 'set record full insn-number-max unlimited' Set the limit of instructions to be recorded for the 'full' d6666 1 a6666 1 'stop-at-limit' option, described below.) d6668 1 a6668 1 If LIMIT is 'unlimited' or zero, GDB will never delete recorded d6672 2 a6673 2 'show record full insn-number-max' Show the limit of instructions to be recorded with the 'full' d6676 2 a6677 2 'set record full stop-at-limit' Control the behavior of the 'full' recording method when the number d6688 2 a6689 2 'show record full stop-at-limit' Show the current setting of 'stop-at-limit'. d6691 1 a6691 1 'set record full memory-query' d6693 1 a6693 1 caused by an instruction for the 'full' recording method. If ON, d6701 2 a6702 2 'show record full memory-query' Show the current setting of 'memory-query'. d6704 1 a6704 1 The 'btrace' record target does not trace data. As a convenience, d6712 4 a6715 4 'set record btrace replay-memory-access' Control the behavior of the 'btrace' recording method when accessing memory during replay. If 'read-only' (the default), GDB will only allow accesses to read-only memory. If 'read-write', GDB d6720 1 a6720 1 'set record btrace cpu IDENTIFIER' d6728 2 a6729 2 the decoding failures. These corrections are known as "errata workarounds", and are enabled based on the processor on which the d6738 2 a6739 2 'VENDOR:PROCESSOR IDENTIFIER'. In addition, there are two special identifiers, 'none' and 'auto' (default). d6744 1 a6744 1 'intel' FAMILY/MODEL[/STEPPING] d6748 1 a6748 1 be obtained from '/proc/cpuinfo'. d6750 1 a6750 1 If IDENTIFIER is 'auto', enable errata workarounds for the d6752 1 a6752 1 'none', errata workarounds are disabled. d6770 2 a6771 2 'show record btrace replay-memory-access' Show the current setting of 'replay-memory-access'. d6773 1 a6773 1 'show record btrace cpu' d6777 2 a6778 2 'set record btrace bts buffer-size SIZE' 'set record btrace bts buffer-size unlimited' d6785 2 a6786 2 buffer size may differ from the requested SIZE. Use the 'info record' command to see the actual buffer size for each thread that d6789 1 a6789 1 If LIMIT is 'unlimited' or zero, GDB will try to allocate a buffer d6796 1 a6796 1 'show record btrace bts buffer-size SIZE' d6800 2 a6801 2 'set record btrace pt buffer-size SIZE' 'set record btrace pt buffer-size unlimited' d6809 1 a6809 1 Use the 'info record' command to see the actual buffer size for d6812 1 a6812 1 If LIMIT is 'unlimited' or zero, GDB will try to allocate a buffer d6819 1 a6819 1 'show record btrace pt buffer-size SIZE' d6823 1 a6823 1 'info record' d6827 2 a6828 2 'full' For the 'full' recording method, it shows the state of process d6831 2 a6832 2 * Whether in record mode or replay mode. * Lowest recorded instruction number (counting from when d6835 2 a6836 2 * Highest recorded instruction number. * Current instruction about to be replayed (if in replay d6838 2 a6839 2 * Number of instructions contained in the execution log. * Maximum number of instructions that may be contained in d6842 2 a6843 2 'btrace' For the 'btrace' recording method, it shows: d6845 3 a6847 3 * Recording format. * Number of instructions that have been recorded. * Number of blocks of sequential control-flow formed by the d6849 1 a6849 1 * Whether in record mode or replay mode. d6851 2 a6852 2 For the 'bts' recording format, it also shows: * Size of the perf ring buffer. d6854 2 a6855 2 For the 'pt' recording format, it also shows: * Size of the perf ring buffer. d6857 1 a6857 1 'record delete' d6863 1 a6863 1 'record instruction-history' d6866 1 a6866 1 using the 'set record instruction-history-size' command. d6870 4 a6873 4 '/m' or '/s' modifier, and print the raw instructions in hex as well as in symbolic form by specifying the '/r' or '/b' modifier. The behaviour of the '/m', '/s', '/r', and '/b' modifiers are the same as for the 'disassemble' command (*note 'disassemble': d6880 1 a6880 1 the '/p' modifier. d6884 1 a6884 1 omitted by specifying the '/f' modifier. d6886 1 a6886 1 Speculatively executed instructions are prefixed with '?'. This d6892 1 a6892 1 'record instruction-history INSN' d6896 1 a6896 1 'record instruction-history INSN, +/-N' d6898 2 a6899 2 If N is preceded with '+', disassembles N instructions after instruction number INSN. If N is preceded with '-', d6902 1 a6902 1 'record instruction-history' d6905 1 a6905 1 'record instruction-history -' d6909 1 a6909 1 'record instruction-history BEGIN, END' d6916 9 a6924 9 'set record instruction-history-size SIZE' 'set record instruction-history-size unlimited' Define how many instructions to disassemble in the 'record instruction-history' command. The default value is 10. A SIZE of 'unlimited' means unlimited instructions. 'show record instruction-history-size' Show how many instructions to disassemble in the 'record instruction-history' command. d6926 1 a6926 1 'record function-call-history' d6930 2 a6931 2 instruction sequence (if the '/l' modifier is specified), and the instructions numbers that form the sequence (if the '/i' modifier d6933 2 a6934 2 stack depth if the '/c' modifier is specified. The '/l', '/i', and '/c' modifiers can be given together. d6953 1 a6953 1 the 'set record function-call-history-size' command. Functions are d6957 1 a6957 1 'record function-call-history FUNC' d6960 1 a6960 1 'record function-call-history FUNC, +/-N' d6962 2 a6963 2 preceded with '+', prints N functions after function number FUNC. If N is preceded with '-', prints N functions before d6966 1 a6966 1 'record function-call-history' d6969 1 a6969 1 'record function-call-history -' d6972 1 a6972 1 'record function-call-history BEGIN, END' d6978 9 a6986 9 'set record function-call-history-size SIZE' 'set record function-call-history-size unlimited' Define how many functions to print in the 'record function-call-history' command. The default value is 10. A size of 'unlimited' means unlimited functions. 'show record function-call-history-size' Show how many functions to print in the 'record function-call-history' command. d7001 2 a7002 2 data called a "stack frame". The stack frames are allocated in a region of memory called the "call stack". d7007 1 a7007 1 One of the stack frames is "selected" by GDB and many GDB commands d7014 1 a7014 1 executing frame and describes it briefly, similar to the 'frame' command d7032 2 a7033 2 The call stack is divided up into contiguous pieces called "stack frames", or "frames" for short; each frame is the data associated with d7039 2 a7040 2 the function 'main'. This is called the "initial" frame or the "outermost" frame. Each time a function is called, a new frame is made. d7044 1 a7044 1 actually occurring is called the "innermost" frame. This is the most d7051 1 a7051 1 kept in a register called the "frame pointer register" (*note $fp: d7054 1 a7054 1 GDB labels each existing stack frame with a "level", a number that is d7057 1 a7057 1 frames in GDB commands. The terms "frame number" and "frame level" can d7062 1 a7062 1 '-fomit-frame-pointer' d7082 2 a7083 2 To print a backtrace of the entire stack, use the 'backtrace' command, or its alias 'bt'. This command will print one line per frame d7086 1 a7086 1 character, normally 'Ctrl-c'. d7088 2 a7089 2 'backtrace [OPTION]... [QUALIFIER]... [COUNT]' 'bt [OPTION]... [QUALIFIER]... [COUNT]' d7094 2 a7095 2 'N' 'N' d7099 2 a7100 2 '-N' '-N' d7106 1 a7106 1 '-full' d7111 1 a7111 1 '-no-filters' d7116 1 a7116 1 with 'Python' support. d7118 1 a7118 1 '-hide' d7122 1 a7122 1 elided. The '-hide' option causes elided frames to not be d7125 3 a7127 3 The 'backtrace' command also supports a number of options that allow overriding relevant global print settings as set by 'set backtrace' and 'set print' subcommands: d7129 2 a7130 2 '-past-main [on|off]' Set whether backtraces should continue past 'main'. Related d7133 1 a7133 1 '-past-entry [on|off]' d7137 1 a7137 1 '-entry-values no|only|preferred|if-needed|both|compact|default' d7141 1 a7141 1 '-frame-arguments all|scalars|none' d7145 1 a7145 1 '-raw-frame-arguments [on|off]' d7149 1 a7149 1 '-frame-info auto|source-line|location|source-and-location|location-and-address|short-location' d7156 2 a7157 2 'full' Equivalent to the '-full' option. d7159 2 a7160 2 'no-filters' Equivalent to the '-no-filters' option. d7162 2 a7163 2 'hide' Equivalent to the '-hide' option. d7165 2 a7166 2 The names 'where' and 'info stack' (abbreviated 'info s') are additional aliases for 'backtrace'. d7170 2 a7171 2 the threads, use the command 'thread apply' (*note thread apply: Threads.). For example, if you type 'thread apply all backtrace', GDB d7176 2 a7177 2 name. The program counter value is also shown--unless you use 'set print address off'. The backtrace also shows the source file name and d7182 2 a7183 2 Here is an example of a backtrace. It was made with the command 'bt 3', so it shows the innermost three frames. d7194 1 a7194 1 for line '993' of 'builtin.c'. d7196 1 a7196 1 The value of parameter 'data' in frame 1 has been replaced by '...'. By d7198 2 a7199 2 (integer, pointer, enumeration, etc). See command 'set print frame-arguments' in *note Print Settings:: for more details on how to d7201 1 a7201 1 'set print frame-info' (*note Print Settings::) controls what frame d7220 1 a7220 1 shown as ''. d7228 1 a7228 1 'main'(1). When GDB finds the entry function in a backtrace it will d7235 2 a7236 2 'set backtrace past-main' 'set backtrace past-main on' d7239 1 a7239 1 'set backtrace past-main off' d7243 1 a7243 1 'show backtrace past-main' d7246 2 a7247 2 'set backtrace past-entry' 'set backtrace past-entry on' d7251 1 a7251 1 'main' (or equivalent) is called. d7253 1 a7253 1 'set backtrace past-entry off' d7257 1 a7257 1 'show backtrace past-entry' d7260 4 a7263 4 'set backtrace limit N' 'set backtrace limit 0' 'set backtrace limit unlimited' Limit the backtrace to N levels. A value of 'unlimited' or zero d7266 1 a7266 1 'show backtrace limit' d7271 2 a7272 2 'set filename-display' 'set filename-display relative' d7276 1 a7276 1 'set filename-display basename' d7279 1 a7279 1 'set filename-display absolute' d7282 1 a7282 1 'show filename-display' d7288 1 a7288 1 environment) are not required to have a 'main' function as the entry d7302 3 a7304 3 'frame [ FRAME-SELECTION-SPEC ]' 'f [ FRAME-SELECTION-SPEC ]' The 'frame' command allows different stack frames to be selected. d7307 2 a7308 2 'NUM' 'level NUM' d7312 1 a7312 1 frame is usually the one for 'main'. d7315 1 a7315 1 stack, the string 'level' can be omitted. For example, the d7321 1 a7321 1 'address STACK-ADDRESS' d7323 2 a7324 2 STACK-ADDRESS for a frame can be seen in the output of 'info frame', for example: d7334 1 a7334 1 The STACK-ADDRESS for this frame is '0x7fffffffda30' as d7339 1 a7339 1 'function FUNCTION-NAME' d7344 1 a7344 1 'view STACK-ADDRESS [ PC-ADDR ]' d7356 1 a7356 1 'frame view' then you can always return to the original stack d7358 1 a7358 1 for example 'frame level 0'. d7360 1 a7360 1 'up N' d7365 1 a7365 1 'down N' d7369 1 a7369 1 abbreviate 'down' as 'do'. d7383 1 a7383 1 After such a printout, the 'list' command with no arguments prints d7386 1 a7386 1 program by typing 'edit'. *Note Printing Source Lines: List, for d7389 2 a7390 2 'select-frame [ FRAME-SELECTION-SPEC ]' The 'select-frame' command is a variant of 'frame' that does not d7394 1 a7394 1 the 'frame' command described in *note Selecting a Frame: d7397 3 a7399 3 'up-silently N' 'down-silently N' These two commands are variants of 'up' and 'down', respectively; d7414 2 a7415 2 'frame' 'f' d7418 1 a7418 1 selected stack frame. It can be abbreviated 'f'. With an d7422 2 a7423 2 'info frame' 'info f' d7427 4 a7430 4 * the address of the frame * the address of the next frame down (called by this frame) * the address of the next frame up (caller of this frame) * the language in which the source code corresponding to this d7432 3 a7434 3 * the address of the frame's arguments * the address of the frame's local variables * the program counter saved in it (the address of execution in d7436 1 a7436 1 * which registers were saved in the frame d7441 2 a7442 2 'info frame [ FRAME-SELECTION-SPEC ]' 'info f [ FRAME-SELECTION-SPEC ]' d7445 1 a7445 1 the 'frame' command (*note Selecting a Frame: Selection.). The d7448 1 a7448 1 'info args [-q]' d7451 1 a7451 1 The optional flag '-q', which stands for 'quiet', disables printing d7455 2 a7456 2 'info args [-q] [-t TYPE_REGEXP] [REGEXP]' Like 'info args', but only print the arguments selected with the d7463 1 a7463 1 as printed by the 'whatis' command, match the regular expression d7471 1 a7471 1 'info locals [-q]' d7477 1 a7477 1 The optional flag '-q', which stands for 'quiet', disables printing d7481 2 a7482 2 'info locals [-q] [-t TYPE_REGEXP] [REGEXP]' Like 'info locals', but only print the local variables selected d7489 1 a7489 1 types, as printed by the 'whatis' command, match the regular d7498 2 a7499 2 The command 'info locals -q -t TYPE_REGEXP' can usefully be combined with the commands 'frame apply' and 'thread apply'. For d7501 2 a7502 2 Initialization types (RAII) such as 'lock_something_t': each local variable of type 'lock_something_t' automatically places a lock d7515 2 a7516 2 'frame apply [all | COUNT | -COUNT | level LEVEL...] [OPTION]... COMMAND' The 'frame apply' command allows you to apply the named COMMAND to d7519 2 a7520 2 'all' Specify 'all' to apply COMMAND to all frames. d7522 1 a7522 1 'COUNT' d7526 1 a7526 1 '-COUNT' d7530 2 a7531 2 'level' Use 'level' to apply COMMAND to the set of frames identified d7534 2 a7535 2 in the first field of the 'backtrace' command output. E.g., '2-4 6-8 3' indicates to apply COMMAND for the frames at d7538 3 a7540 3 Note that the frames on which 'frame apply' applies a command are also influenced by the 'set backtrace' settings such as 'set backtrace past-main' and 'set backtrace limit N'. *Note d7543 2 a7544 2 The 'frame apply' command also supports a number of options that allow overriding relevant 'set backtrace' settings: d7546 2 a7547 2 '-past-main [on|off]' Whether backtraces should continue past 'main'. Related d7550 1 a7550 1 '-past-entry [on|off]' d7556 1 a7556 1 COMMAND will abort 'frame apply'. The following options can be d7559 3 a7561 3 '-c' The flag '-c', which stands for 'continue', causes any errors in COMMAND to be displayed, and the execution of 'frame apply' d7563 2 a7564 2 '-s' The flag '-s', which stands for 'silent', causes any errors or d7568 2 a7569 2 '-q' The flag '-q' ('quiet') disables printing the frame d7572 3 a7574 3 The following example shows how the flags '-c' and '-s' are working when applying the command 'p j' to all frames, where variable 'j' can only be successfully printed in the outermost '#1 main' frame. d7589 1 a7589 1 By default, 'frame apply', prints the frame location information d7599 1 a7599 1 If the flag '-q' is given, no frame information is printed: d7605 2 a7606 2 'faas COMMAND' Shortcut for 'frame apply all -s COMMAND'. Applies COMMAND on all d7614 1 a7614 1 The 'faas' command accepts the same options as the 'frame apply' d7617 1 a7617 1 Note that the command 'tfaas COMMAND' applies COMMAND on all frames d7632 1 a7632 1 'info frame-filter' d7636 1 a7636 1 'disable frame-filter FILTER-DICTIONARY FILTER-NAME' d7638 3 a7640 3 and FILTER-NAME. The FILTER-DICTIONARY may be 'all', 'global', 'progspace', or the name of the object file where the frame filter dictionary resides. When 'all' is specified, all frame filters d7642 1 a7642 1 of the frame filter and is used when 'all' is not the option for d7646 1 a7646 1 'enable frame-filter FILTER-DICTIONARY FILTER-NAME' d7648 3 a7650 3 and FILTER-NAME. The FILTER-DICTIONARY may be 'all', 'global', 'progspace' or the name of the object file where the frame filter dictionary resides. When 'all' is specified, all frame filters d7652 1 a7652 1 of the frame filter and is used when 'all' is not the option for d7704 1 a7704 1 'set frame-filter priority FILTER-DICTIONARY FILTER-NAME PRIORITY' d7707 1 a7707 1 The FILTER-DICTIONARY may be 'global', 'progspace' or the name of d7711 1 a7711 1 'show frame-filter priority FILTER-DICTIONARY FILTER-NAME' d7714 1 a7714 1 The FILTER-DICTIONARY may be 'global', 'progspace' or the name of d7784 2 a7785 2 To print lines from a source file, use the 'list' command (abbreviated 'l'). By default, ten lines are printed. There are several ways to d7789 1 a7789 1 Here are the forms of the 'list' command most commonly used: d7791 1 a7791 1 'list LINENUM' d7795 1 a7795 1 'list FUNCTION' d7798 1 a7798 1 'list' d7800 1 a7800 1 'list' command, this prints lines following the last lines printed; d7803 1 a7803 1 Stack.), this prints lines centered around that line. If no 'list' d7805 1 a7805 1 the lines around the function 'main'. d7807 1 a7807 1 'list +' d7810 1 a7810 1 'list -' d7813 1 a7813 1 'list .' d7819 1 a7819 1 the 'list' command. You can change this using 'set listsize': d7821 12 a7832 12 'set listsize COUNT' 'set listsize unlimited' Make the 'list' command display COUNT source lines (unless the 'list' argument explicitly specifies some other number). Setting COUNT to 'unlimited' or 0 means there's no limit. 'show listsize' Display the number of lines that 'list' prints. Repeating a 'list' command with discards the argument, so it is equivalent to typing just 'list'. This is more useful than listing the same lines again. An exception is made for an argument of '-'; that d7836 1 a7836 1 In general, the 'list' command expects you to supply zero, one or two d7842 1 a7842 1 Here is a complete description of the possible arguments for 'list': d7844 1 a7844 1 'list LOCSPEC' d7848 1 a7848 1 'list FIRST,LAST' d7850 1 a7850 1 When a 'list' command has two location specs, and the source file d7857 1 a7857 1 'list ,LAST' d7864 1 a7864 1 'list FIRST,' d7867 1 a7867 1 'list +' d7870 1 a7870 1 'list -' d7873 1 a7873 1 'list' d7887 1 a7887 1 "location specification", or "location spec". This section documents d7891 1 a7891 1 program, known as "code location", that corresponds to the given d7893 1 a7893 1 corresponding to a location spec "location resolution". d7916 1 a7916 1 * The location spec specifies a function name, and there are several d7919 1 a7919 1 function name, such as 'A::func(int)' instead of just 'func'.) d7921 1 a7921 1 * The location spec specifies a source file name, and there are d7927 1 a7927 1 * For a C++ constructor, the GCC compiler generates several instances d7931 1 a7931 1 * For a C++ template function, a given line in the function can d7934 1 a7934 1 * For an inlined function, a given source line can correspond to d7941 1 a7941 1 * Some parts of the program lack detailed enough debug info, so the d7948 1 a7948 1 * The location spec specifies a function name, and there are no d7952 1 a7952 1 * The location spec specifies a source file name, and there are no d7956 1 a7956 1 * The location spec specifies both a source file name and a source d7977 1 a7977 1 A "linespec" is a colon-separated list of source location parameters d7981 1 a7981 1 'LINENUM' d7984 4 a7987 4 '-OFFSET' '+OFFSET' Specifies the line OFFSET lines before or after the "current line". For the 'list' command, the current line is the last one printed; d7989 1 a7989 1 stopped in the currently selected "stack frame" (*note Frames: d7991 1 a7991 1 second of the two linespecs in a 'list' command, this specifies the d7994 1 a7994 1 'FILENAME:LINENUM' d7998 3 a8000 3 FILENAME is 'gcc/expr.c', then it will match source file name of '/build/trunk/gcc/expr.c', but not '/build/trunk/libcpp/expr.c' or '/build/trunk/gcc/x-expr.c'. d8002 1 a8002 1 'FUNCTION' d8010 2 a8011 2 For example, assuming a program with C++ symbols named 'A::B::func' and 'B::func', both commands 'break func' and 'break B::func' set a d8015 3 a8017 3 '-qualified' option. For example, 'break -qualified func' sets a breakpoint on a free-function named 'func' ignoring any C++ class methods and namespace functions called 'func'. d8021 1 a8021 1 'FUNCTION:LABEL' d8024 1 a8024 1 'FILENAME:FUNCTION' d8030 1 a8030 1 'LABEL' d8036 2 a8037 2 '-pstap|-probe-stap [OBJFILE:[PROVIDER:]]NAME' The GNU/Linux tool 'SystemTap' provides a way for applications to d8054 1 a8054 1 "Explicit locations" allow the user to directly specify the source d8063 3 a8065 3 For example, the linespec 'foo:bar' may refer to a function 'bar' defined in the file named 'foo' or the label 'bar' in a function named 'foo'. GDB must search either the file system or the symbol table to d8071 1 a8071 1 '-source FILENAME' d8075 1 a8075 1 'foo/bar/baz.c'. Otherwise GDB will use the first file it finds d8077 1 a8077 1 '-function' or '-line'. d8079 1 a8079 1 '-function FUNCTION' d8081 1 a8081 1 locations unmodified by other options (such as '-label' or '-line') d8089 3 a8091 3 For example, assuming a program with C++ symbols named 'A::B::func' and 'B::func', both commands 'break -function func' and 'break -function B::func' set a breakpoint on both symbols. d8093 1 a8093 1 You can use the '-qualified' flag to override this (see below). d8095 1 a8095 1 '-qualified' d8098 1 a8098 1 '-function' as a complete fully-qualified name. d8100 3 a8102 3 For example, assuming a C++ program with symbols named 'A::B::func' and 'B::func', the 'break -qualified -function B::func' command sets a breakpoint on 'B::func', only. d8104 1 a8104 1 (Note: the '-qualified' option can precede a linespec as well d8106 1 a8106 1 be simplified as 'break -qualified B::func'.) d8108 1 a8108 1 '-label LABEL' d8113 1 a8113 1 '-line NUMBER' d8115 1 a8115 1 either be absolute ('-line 3') or relative ('-line +3'), depending d8121 1 a8121 1 'break -s main.c -li 3'. d8129 1 a8129 1 "Address locations" indicate a specific program address. They have the d8132 2 a8133 2 For line-oriented commands, such as 'list' and 'edit', this specifies a source line that contains ADDRESS. For 'break' and other d8145 1 a8145 1 'EXPRESSION' d8148 1 a8148 1 'FUNCADDR' d8152 2 a8153 2 valid expression). In Pascal and Modula-2, this is '&FUNCTION'. In Ada, this is 'FUNCTION'Address' (although the Pascal form also d8159 1 a8159 1 ''FILENAME':FUNCADDR' d8171 1 a8171 1 To edit the lines in a source file, use the 'edit' command. The editing d8177 1 a8177 1 'edit LOCSPEC' d8179 2 a8180 2 resolving 'locspec'. Editing starts at the source file and source line 'locspec' resolves to. *Note Location Specifications::, for d8183 1 a8183 1 If 'locspec' resolves to more than one source line in your program, d8187 1 a8187 1 Here are the forms of the 'edit' command most commonly used: d8189 1 a8189 1 'edit NUMBER' d8193 1 a8193 1 'edit FUNCTION' d8201 3 a8203 3 '/bin/ex', but you can change this by setting the environment variable 'EDITOR' before using GDB. For example, to configure GDB to use the 'vi' editor, you could use these commands with the 'sh' shell: d8207 1 a8207 1 or in the 'csh' shell, d8213 1 a8213 1 (1) The only restriction is that your editor (say 'ex'), recognizes d8228 3 a8230 3 'forward-search REGEXP' 'search REGEXP' The command 'forward-search REGEXP' checks each line, starting with d8232 2 a8233 2 lists the line that is found. You can use the synonym 'search REGEXP' or abbreviate the command name as 'fo'. d8235 2 a8236 2 'reverse-search REGEXP' The command 'reverse-search REGEXP' checks each line, starting with d8239 1 a8239 1 this command as 'rev'. d8251 1 a8251 1 files; this is called the "source path". Each time GDB wants a source d8256 2 a8257 2 '/usr/src/foo-1.0/lib/foo.c', does not record a compilation directory, and the "source path" is '/mnt/cross'. GDB would look for the source d8260 3 a8262 3 1. '/usr/src/foo-1.0/lib/foo.c' 2. '/mnt/cross/usr/src/foo-1.0/lib/foo.c' 3. '/mnt/cross/foo.c' d8266 1 a8266 1 name, such as '/mnt/cross/src/foo-1.0/lib/foo.c'. Likewise, the d8268 2 a8269 2 is '/mnt/cross', and the binary refers to 'foo.c', GDB would not find it under '/mnt/cross/usr/src/foo-1.0/lib'. d8274 2 a8275 2 "source path" is '/mnt/cross', the source file is recorded as '../lib/foo.c', and no compilation directory is recorded, then GDB will d8278 2 a8279 2 1. '/mnt/cross/../lib/foo.c' 2. '/mnt/cross/foo.c' d8281 2 a8282 2 The "source path" will always include two special entries '$cdir' and '$cwd', these refer to the compilation directory (if one is recorded) d8285 1 a8285 1 '$cdir' causes GDB to search within the compilation directory, if one d8287 1 a8287 1 recorded in the debug information then '$cdir' is ignored. d8289 1 a8289 1 '$cwd' is not the same as '.'--the former tracks the current working d8295 3 a8297 3 GDB has not found the source file after the first search using "source path", then GDB will combine the compilation directory and the filename, and then search for the source file again using the "source path". d8300 3 a8302 3 '/usr/src/foo-1.0/lib/foo.c', the compilation directory is recorded as '/project/build', and the "source path" is '/mnt/cross:$cdir:$cwd' while the current working directory of the GDB session is '/home/user', then d8305 10 a8314 10 1. '/usr/src/foo-1.0/lib/foo.c' 2. '/mnt/cross/usr/src/foo-1.0/lib/foo.c' 3. '/project/build/usr/src/foo-1.0/lib/foo.c' 4. '/home/user/usr/src/foo-1.0/lib/foo.c' 5. '/mnt/cross/project/build/usr/src/foo-1.0/lib/foo.c' 6. '/project/build/project/build/usr/src/foo-1.0/lib/foo.c' 7. '/home/user/project/build/usr/src/foo-1.0/lib/foo.c' 8. '/mnt/cross/foo.c' 9. '/project/build/foo.c' 10. '/home/user/foo.c' d8322 1 a8322 1 absolute paths start with a drive letter (e.g. 'C:/project/foo.c'), GDB d8324 3 a8326 3 search directory from "source path"; for instance if the executable references the source file 'C:/project/foo.c' and "source path" is set to 'D:/mnt/cross', then GDB will search in the following locations for d8329 3 a8331 3 1. 'C:/project/foo.c' 2. 'D:/mnt/cross/project/foo.c' 3. 'D:/mnt/cross/foo.c' d8340 2 a8341 2 When you start GDB, its source path includes only '$cdir' and '$cwd', in that order. To add other directories, use the 'directory' command. d8344 1 a8344 1 script files (read using the '-command' option and 'source' command). d8347 1 a8347 1 manage a list of source path substitution rules. A "substitution rule" d8358 6 a8363 6 Using the previous example, suppose the 'foo-1.0' tree has been moved from '/usr/src' to '/mnt/cross', then you can tell GDB to replace '/usr/src' in all source path names with '/mnt/cross'. The first lookup will then be '/mnt/cross/foo-1.0/lib/foo.c' in place of the original location of '/usr/src/foo-1.0/lib/foo.c'. To define a source path substitution rule, use the 'set substitute-path' command (*note set d8368 2 a8369 2 instance, a rule substituting '/usr/source' into '/mnt/cross' will be applied to '/usr/source/foo-1.0' but not to '/usr/sourceware/foo-2.0'. d8372 1 a8372 1 '/root/usr/source/baz.c' either. d8374 2 a8375 2 In many cases, you can achieve the same result using the 'directory' command. However, 'set substitute-path' can be more efficient in the d8377 1 a8377 1 subdirectories. With the 'directory' command, you need to add each d8379 1 a8379 1 preserving its internal organization, then 'set substitute-path' allows d8382 1 a8382 1 'set substitute-path' is also more than just a shortcut command. The d8384 1 a8384 1 exists. On the other hand, 'set substitute-path' modifies the debugger d8391 1 a8391 1 configuring GDB with the '--with-relocated-sources=DIR' option. The DIR d8393 1 a8393 1 with '--prefix' or '--exec-prefix'), and directory names in debug d8399 2 a8400 2 'directory DIRNAME ...' 'dir DIRNAME ...' d8402 2 a8403 2 directory names may be given to this command, separated by ':' (';' on MS-DOS and MS-Windows, where ':' usually appears as part of d8408 2 a8409 2 The special strings '$cdir' (to refer to the compilation directory, if one is recorded), and '$cwd' (to refer to the current working d8414 2 a8415 2 'directory' Reset the source path to its default value ('$cdir:$cwd' on Unix d8418 2 a8419 2 'set directories PATH-LIST' Set the source path to PATH-LIST. '$cdir:$cwd' are added if d8422 1 a8422 1 'show directories' d8425 1 a8425 1 'set substitute-path FROM TO' d8431 2 a8432 2 For example, if the file '/foo/bar/baz.c' was moved to '/mnt/cross/baz.c', then the command d8436 2 a8437 2 will tell GDB to replace '/foo/bar' with '/mnt/cross', which will allow GDB to find the file 'baz.c' even though it was moved. d8449 4 a8452 4 GDB would then rewrite '/usr/src/include/defs.h' into '/mnt/include/defs.h' by using the first rule. However, it would use the second rule to rewrite '/usr/src/lib/foo.c' into '/mnt/src/lib/foo.c'. d8454 1 a8454 1 'unset substitute-path [path]' d8462 1 a8462 1 'show substitute-path [path]' d8473 1 a8473 1 1. Use 'directory' with no argument to reset the source path to its d8476 1 a8476 1 2. Use 'directory' with suitable arguments to reinstall the d8486 2 a8487 2 You can use the command 'info line' to map source lines to program addresses (and vice versa), and the command 'disassemble' to display a d8489 4 a8492 4 'set disassemble-next-line' to set whether to disassemble next source line when execution stops. When run under GNU Emacs mode, the 'info line' command causes the arrow to point to the line specified. Also, 'info line' prints addresses in symbolic form as well as hex. d8494 2 a8495 2 'info line' 'info line LOCSPEC' d8502 2 a8503 2 For example, we can use 'info line' to discover the location of the object code for the first line of function 'm4_changequote': d8509 1 a8509 1 We can also inquire, using '*ADDR' as the form for LOCSPEC, what source d8515 2 a8516 2 After 'info line', the default address for the 'x' command is changed to the starting address of the line, so that 'x/i' is sufficient to d8519 1 a8519 1 '$_' (*note Convenience Variables: Convenience Vars.). d8521 1 a8521 1 After 'info line', using 'info line' again without specifying a d8524 5 a8528 5 'disassemble' 'disassemble /m' 'disassemble /s' 'disassemble /r' 'disassemble /b' d8531 2 a8532 2 specifying the '/m' or '/s' modifier and print the raw instructions in hex as well as in symbolic form by specifying the '/r' or '/b' d8535 1 a8535 1 Only one of '/m' and '/s' can be used, attempting to use both flag d8538 1 a8538 1 Only one of '/r' and '/b' can be used, attempting to use both flag d8548 1 a8548 1 'START,END' d8550 2 a8551 2 'START,+LENGTH' the addresses from START (inclusive) to 'START+LENGTH' d8559 1 a8559 1 such as '0x32c4', '&main+10' or '$pc - 8'. d8562 1 a8562 1 counter, the instruction at that location is shown with a '=>' d8581 1 a8581 1 difference between the '/r' and '/b' modifiers. First with '/b', the d8592 1 a8592 1 In contrast, with '/r' the bytes of the instruction are displayed in d8605 1 a8605 1 '/m' or '/s', when the program is stopped just after function prologue d8629 2 a8630 2 The '/m' option is deprecated as its output is not useful when there is either inlined code or re-ordered code. The '/s' option is the d8632 1 a8632 1 difference between '/m' output and '/s' output. This example has one d8634 2 a8635 2 '-O2' optimization. Note how the '/m' output is missing the disassembly of several instructions that are present in the '/s' output. d8637 1 a8637 1 'foo.h': d8649 1 a8649 1 'foo.c': d8722 1 a8722 1 Note that the 'disassemble' command's address arguments are specified d8725 3 a8727 3 So, for example, if you want to disassemble function 'bar' in file 'foo.c', you must type 'disassemble 'foo.c'::bar' and not 'disassemble foo.c:bar'. d8738 1 a8738 1 'set disassembler-options OPTION1[,OPTION2...]' d8741 2 a8742 2 '-M'/'--disassembler-options' section of the 'objdump' manual and/or the output of 'objdump --help' (*note objdump: d8750 1 a8750 1 'show disassembler-options' d8753 1 a8753 1 'set disassembly-flavor INSTRUCTION-SET' d8755 1 a8755 1 via the 'disassemble' or 'x/i' commands. d8758 2 a8759 2 You can set INSTRUCTION-SET to either 'intel' or 'att'. The default is 'att', the AT&T flavor used by default by Unix d8762 1 a8762 1 'show disassembly-flavor' d8765 2 a8766 2 'set disassemble-next-line' 'show disassemble-next-line' d8795 3 a8797 3 'set source open [on|off]' 'show source open' When this option is 'on', which is the default, GDB will access d8799 1 a8799 1 when GDB stops, or in response to the 'list' command. d8801 1 a8801 1 When this option is 'off', GDB will not access source code files. d8809 2 a8810 2 The usual way to examine data in your program is with the 'print' command (abbreviated 'p'), or its synonym 'inspect'. It evaluates and d8816 2 a8817 2 'print [[OPTIONS] --] EXPR' 'print [[OPTIONS] --] /F EXPR' d8820 1 a8820 1 you can choose a different format by specifying '/F', where F is a d8824 2 a8825 2 The 'print' command supports a number of options that allow overriding relevant global print settings as set by 'set print' d8828 1 a8828 1 '-address [on|off]' d8832 1 a8832 1 '-array [on|off]' d8836 1 a8836 1 '-array-indexes [on|off]' d8840 2 a8841 2 '-characters NUMBER-OF-CHARACTERS|elements|unlimited' Set limit on string characters to print. The value 'elements' d8843 1 a8843 1 value 'unlimited' causes there to be no limit. Related d8846 1 a8846 1 '-elements NUMBER-OF-ELEMENTS|unlimited' d8849 2 a8850 2 '-characters' option above for when this option applies to strings. The value 'unlimited' causes there to be no limit. d8853 1 a8853 1 '-max-depth DEPTH|unlimited' d8857 1 a8857 1 '-nibbles [on|off]' d8861 1 a8861 1 '-memory-tag-violations [on|off]' d8865 1 a8865 1 '-null-stop [on|off]' d8869 1 a8869 1 '-object [on|off]' d8873 1 a8873 1 '-pretty [on|off]' d8877 1 a8877 1 '-raw-values [on|off]' d8882 2 a8883 2 '-repeats NUMBER-OF-REPEATS|unlimited' Set threshold for repeated print elements. 'unlimited' causes d8887 1 a8887 1 '-static-members [on|off]' d8891 1 a8891 1 '-symbol [on|off]' d8895 1 a8895 1 '-union [on|off]' d8899 1 a8899 1 '-vtbl [on|off]' d8903 1 a8903 1 Because the 'print' command accepts arbitrary expressions which may d8905 1 a8905 1 command option, then you must use a double dash ('--') to mark the d8908 1 a8908 1 For example, this prints the value of the '-p' expression: d8913 1 a8913 1 with the '-pretty' option in effect: d8929 2 a8930 2 'print [OPTIONS]' 'print [OPTIONS] /F' d8932 1 a8932 1 "value history"; *note Value History: Value History.). This allows d8936 1 a8936 1 If the architecture supports memory tagging, the 'print' command will d8940 1 a8940 1 A more low-level way of examining data is with the 'x' command. It d8945 2 a8946 2 fields of a struct or a class are declared, use the 'ptype EXPR' command rather than 'print'. *Note Examining the Symbol Table: Symbols. d8949 2 a8950 2 is through the Python extension command 'explore' (available only if the GDB build is configured with '--with-python'). It offers an interactive d8956 1 a8956 1 'explore ARG' d8960 2 a8961 2 The working of the 'explore' command can be illustrated with an example. If a data type 'struct ComplexStruct' is defined in your C d8981 1 a8981 1 then, the value of the variable 'cs' can be explored using the 'explore' d8993 1 a8993 1 Since the fields of 'cs' are not scalar values, you are being prompted d8995 1 a8995 1 'ss_p' by entering '0'. Then, since this field is a pointer, you will d8997 2 a8998 2 'cs' above, it is indeed pointing to a single value, hence you enter 'y'. If you enter 'n', then you will be asked if it were pointing to an d9012 1 a9012 1 If the field 'arr' of 'cs' was chosen for exploration by entering '1' d9030 1 a9030 1 Similar to exploring values, you can use the 'explore' command to d9034 2 a9035 2 same example as above, your can explore the type 'struct ComplexStruct' by passing the argument 'struct ComplexStruct' to the 'explore' command. d9040 2 a9041 2 session, you can explore the type 'struct ComplexStruct' in a manner similar to how the value 'cs' was explored in the above example. d9043 2 a9044 2 The 'explore' command also has two sub-commands, 'explore value' and 'explore type'. The former sub-command is a way to explicitly specify d9049 2 a9050 2 'explore value EXPR' This sub-command of 'explore' explores the value of the expression d9053 1 a9053 1 to that of the behavior of the 'explore' command being passed the d9056 2 a9057 2 'explore type ARG' This sub-command of 'explore' explores the type of ARG (if ARG is a d9062 1 a9062 1 'explore' command being passed the argument ARG. If ARG is an d9064 1 a9064 1 that of the 'explore' command being passed the type of ARG as the d9101 1 a9101 1 'print' and many other GDB commands accept an expression and compute its d9110 1 a9110 1 'print {1, 2, 3}' to create an array of three integers. If you pass an d9112 1 a9112 1 array to memory that is 'malloc'ed in the target program. d9128 2 a9129 2 '@@' '@@' is a binary operator for treating parts of memory as arrays. d9132 2 a9133 2 '::' '::' allows you to specify a variable in terms of the file or d9136 1 a9136 1 '{TYPE} ADDR' d9152 2 a9153 2 application in different contexts. This is called "overloading". Another example involving Ada is generics. A "generic package" is d9159 2 a9160 2 specify the signature of the function you want to break on, as in 'break FUNCTION(TYPES)'. In Ada, using the fully qualified name of your d9165 2 a9166 2 possibility, and then waits for the selection with the prompt '>'. The first option is always '[0] cancel', and typing '0 ' aborts the d9168 2 a9169 2 more than one choice to be selected, the next option in the menu is '[1] all', and typing '1 ' selects all possible choices. d9172 1 a9172 1 breakpoint at the overloaded symbol 'String::after'. We choose three d9193 1 a9193 1 'set multiple-symbols MODE' d9198 1 a9198 1 By default, MODE is set to 'all'. If the command with which the d9207 1 a9207 1 When MODE is set to 'ask', the debugger always uses the menu when d9210 1 a9210 1 Finally, when MODE is set to 'cancel', the debugger reports an d9213 2 a9214 2 'show multiple-symbols' Show the current value of the 'multiple-symbols' setting. d9228 1 a9228 1 * global (or file-static) d9232 1 a9232 1 * visible according to the scope rules of the programming language d9247 3 a9249 3 you can examine and use the variable 'a' whenever your program is executing within the function 'foo', but you can only use or examine the variable 'b' while your program is executing inside the block where 'b' d9258 1 a9258 1 using the colon-colon ('::') notation: d9266 1 a9266 1 global value of 'x' defined in 'f2.c': d9270 1 a9270 1 The '::' notation is normally used for referring to static variables, d9293 1 a9293 1 'bar(0)': d9306 1 a9306 1 These uses of '::' are very rarely in conflict with the very similar d9312 2 a9313 2 that has a field named 'includefile', and there is also an include file named 'includefile' that defines a variable, 'some_global'. d9355 1 a9355 1 information, GDB will say ''. *Note incomplete type: d9370 1 a9370 1 If you append '@@entry' string to a function parameter name you get d9385 5 a9389 5 Strings are identified as arrays of 'char' values without specified signedness. Arrays of either 'signed char' or 'unsigned char' get printed as arrays of 1 byte sized integers. '-fsigned-char' or '-funsigned-char' GCC options have no effect as GDB defines literal string type '"char"' as 'char' without a sign. For program code d9411 2 a9412 2 "artificial array", using the binary operator '@@'. The left operand of '@@' should be the first element of the desired array and be an d9422 1 a9422 1 you can print the contents of 'array' with d9426 2 a9427 2 The left operand of '@@' must reside in memory. Array values made with '@@' in this way behave just like other arrays in terms of d9439 2 a9440 2 '(TYPE[])VALUE') GDB calculates the size to fill the value (as 'sizeof(VALUE)/sizeof(TYPE)': d9451 2 a9452 2 you have an array 'dtab' of pointers to structures, and you are interested in the values of a field 'fv' in each structure. Here is an d9471 1 a9471 1 instruction. To do these things, specify an "output format" when you d9475 1 a9475 1 already computed. This is done by starting the arguments of the 'print' d9479 1 a9479 1 'x' d9482 1 a9482 1 'd' d9485 1 a9485 1 'u' d9489 1 a9489 1 'o' d9492 1 a9492 1 't' d9494 1 a9494 1 't' stands for "two". (1) d9496 1 a9496 1 'a' d9504 1 a9504 1 The command 'info symbol 0x54320' yields similar results. *Note d9507 1 a9507 1 'c' d9512 1 a9512 1 octal escape '\nnn' for characters outside the 7-bit ASCII range. d9514 2 a9515 2 Without this format, GDB displays 'char', 'unsigned char', and 'signed char' data as character constants. Single-byte members of d9518 1 a9518 1 'f' d9522 1 a9522 1 's' d9528 2 a9529 2 Without this format, GDB displays pointers to and arrays of 'char', 'unsigned char', and 'signed char' as strings. Single-byte members d9532 2 a9533 2 'z' Like 'x' formatting, the value is treated as an integer and printed d9537 2 a9538 2 'r' Print using the 'raw' formatting. By default, GDB will use a d9541 1 a9541 1 the value's contents. The 'r' format bypasses any Python d9553 2 a9554 2 format, you can use the 'print' command with just a format and no expression. For example, 'p/x' reprints the last value in hex. d9558 2 a9559 2 (1) 'b' cannot be used because these format letters are also used with the 'x' command, where 'b' stands for "byte"; see *note Examining d9568 1 a9568 1 You can use the command 'x' (for "examine") to examine memory in any of d9571 4 a9574 4 'x/NFU ADDR' 'x ADDR' 'x' Use the 'x' command to examine memory. d9579 1 a9579 1 for NFU, you need not type the slash '/'. Several commands set d9589 3 a9591 3 The display format is one of the formats used by 'print' ('x', 'd', 'u', 'o', 't', 'a', 'c', 'f', 's'), 'i' (for machine instructions) and 'm' (for displaying memory tags). The default is 'x' d9593 1 a9593 1 either 'x' or 'print'. d9598 1 a9598 1 'b' d9600 1 a9600 1 'h' d9602 1 a9602 1 'w' d9604 1 a9604 1 'g' d9607 6 a9612 6 Each time you specify a unit size with 'x', that size becomes the default unit the next time you use 'x'. For the 'i' format, the unit size is ignored and is normally not written. For the 's' format, the unit size defaults to 'b', unless it is explicitly given. Use 'x /hs' to display 16-bit char strings and 'x /ws' to display 32-bit strings. The next use of 'x /s' will again display d9615 1 a9615 1 the 's' modifier will use the UTF-16 encoding while 'w' will use d9626 9 a9634 9 address: 'info breakpoints' (to the address of the last breakpoint listed), 'info line' (to the starting address of a line), and 'print' (if you use it to display a value from memory). For example, 'x/3uh 0x54320' is a request to display three halfwords ('h') of memory, formatted as unsigned decimal integers ('u'), starting at address '0x54320'. 'x/4xw $sp' prints the four words ('w') of memory above the stack pointer (here, '$sp'; *note Registers: Registers.) in hexadecimal ('x'). d9637 2 a9638 2 backward from the given address. For example, 'x/-3uh 0x54320' prints three halfwords ('h') at '0x5431a', '0x5431c', and '0x5431e'. d9643 2 a9644 2 specifications '4xw' and '4wx' mean exactly the same thing. (However, the count N must come first; 'wx4' does not work.) d9646 2 a9647 2 Even though the unit size U is ignored for the formats 's' and 'i', you might still want to use a count N; for example, '3i' specifies that d9649 1 a9649 1 convenience, especially when used with the 'display' command, the 'i' d9652 1 a9652 1 within the count. The command 'disassemble' gives an alternative way of d9656 1 a9656 1 If a negative repeat count is specified for the formats 's' or 'i', d9659 1 a9659 1 the 'i' format, we use line number information in the debug info to d9664 1 a9664 1 All the defaults for the arguments to 'x' are designed to make it d9666 3 a9668 3 you use 'x'. For example, after you have inspected three machine instructions with 'x/3i ADDR', you can inspect the next seven with just 'x/7'. If you use to repeat the 'x' command, the repeat count N d9670 1 a9670 1 'x'. d9673 1 a9673 1 program counter is shown with a '=>' marker. For example: d9683 1 a9683 1 displayed by using 'm'. *Note Memory Tagging::. d9689 1 a9689 1 Due to the way GDB prints information with the 'x' command (not d9692 1 a9692 1 boundary is crossed in the middle of a line displayed by the 'x' d9695 2 a9696 2 The 'm' format doesn't affect any other specified formats that were passed to the 'x' command. d9698 1 a9698 1 The addresses and contents printed by the 'x' command are not saved d9702 2 a9703 2 '$_' and '$__'. After an 'x' command, the last address examined is available for use in expressions in the convenience variable '$_'. The d9705 1 a9705 1 variable '$__'. d9707 1 a9707 1 If the 'x' command has a repeat count, the address and contents saved d9715 1 a9715 1 and this document, the term "addressable memory unit" (or "memory unit" d9717 1 a9717 1 size. The word "byte" is used to refer to a chunk of data of 8 bits, d9726 1 a9726 1 'compare-sections' command is provided for such situations. d9728 1 a9728 1 'compare-sections [SECTION-NAME|-r]' d9733 1 a9733 1 '-r', compares all loadable read-only sections. d9768 1 a9768 1 The 'print' (*note Data::) and 'x' (*note Memory::) commands will d9770 1 a9770 1 'memory-tag' gives access to the various memory tagging commands. d9772 1 a9772 1 The 'memory-tag' commands are the following: d9774 1 a9774 1 'memory-tag print-logical-tag POINTER_EXPRESSION' d9776 1 a9776 1 'memory-tag with-logical-tag POINTER_EXPRESSION TAG_BYTES' d9779 1 a9779 1 'memory-tag print-allocation-tag ADDRESS_EXPRESSION' d9782 1 a9782 1 'memory-tag setatag STARTING_ADDRESS LENGTH TAG_BYTES' d9785 1 a9785 1 'memory-tag check POINTER_EXPRESSION' d9804 2 a9805 2 (to see how it changes), you might want to add it to the "automatic display list" so that GDB prints its value each time your program stops. d9814 5 a9818 5 As with displays you request manually using 'x' or 'print', you can specify the output format you prefer; in fact, 'display' decides whether to use 'print' or 'x' depending your format specification--it uses 'x' if you specify either the 'i' or 's' format, or a unit size; otherwise it uses 'print'. d9820 1 a9820 1 'display EXPR' d9824 1 a9824 1 'display' does not repeat if you press again after using it. d9826 1 a9826 1 'display/FMT EXPR' d9832 2 a9833 2 'display/FMT ADDR' For FMT 'i' or 's', or including a unit-size or a number of units, d9835 2 a9836 2 time your program stops. Examining means in effect doing 'x/FMT ADDR'. *Note Examining Memory: Memory. d9838 2 a9839 2 For example, 'display/i $pc' can be helpful, to see the machine instruction about to be executed each time execution stops ('$pc' is a d9842 2 a9843 2 'undisplay DNUMS...' 'delete display DNUMS...' d9847 2 a9848 2 numbers shown in the first field of the 'info display' display; or it could be a range of display numbers, as in '2-4'. d9850 2 a9851 2 'undisplay' does not repeat if you press after using it. (Otherwise you would just get the error 'No display number ...'.) d9853 1 a9853 1 'disable display DNUMS...' d9859 2 a9860 2 'info display' display; or it could be a range of display numbers, as in '2-4'. d9862 1 a9862 1 'enable display DNUMS...' d9868 2 a9869 2 'info display' display; or it could be a range of display numbers, as in '2-4'. d9871 1 a9871 1 'display' d9875 1 a9875 1 'info display' d9886 2 a9887 2 variables is not defined. For example, if you give the command 'display last_char' while inside a function with an argument 'last_char', GDB d9890 2 a9891 2 'last_char'--the display is disabled automatically. The next time your program stops where 'last_char' is meaningful, you can enable the d9905 2 a9906 2 'set print address' 'set print address on' d9910 2 a9911 2 is 'on'. For example, this is what a stack frame display looks like with 'set print address on': d9918 1 a9918 1 'set print address off' d9920 2 a9921 2 example, this is the same stack frame displayed with 'set print address off': d9928 1 a9928 1 You can use 'set print address off' to eliminate all machine d9930 1 a9930 1 'print address off', you should get the same text for backtraces on d9933 1 a9933 1 'show print address' d9939 2 a9940 2 source file), you may need to clarify. One way to do this is with 'info line', for example 'info line *0x4537'. Alternately, you can set GDB to d9943 1 a9943 1 'set print symbol-filename on' d9947 1 a9947 1 'set print symbol-filename off' d9951 1 a9951 1 'show print symbol-filename' d9962 2 a9963 2 'set print max-symbolic-offset MAX-OFFSET' 'set print max-symbolic-offset unlimited' d9966 1 a9966 1 than MAX-OFFSET. The default is 'unlimited', which tells GDB to d9968 1 a9968 1 it. Zero is equivalent to 'unlimited'. d9970 1 a9970 1 'show print max-symbolic-offset' d9974 3 a9976 3 If you have a pointer and you are not sure where it points, try 'set print symbol-filename on'. Then you can determine the name and source file location of the variable where it points, using 'p/a POINTER'. d9978 2 a9979 2 shows that a variable 'ptt' points at another variable 't', defined in 'hi2.c': d9985 1 a9985 1 _Warning:_ For pointers that point to a local variable, 'p/a' does d9987 1 a9987 1 the appropriate 'set print' options turned on. d9989 2 a9990 2 You can also enable '/a'-like formatting all the time using 'set print symbol on': d9992 1 a9992 1 'set print symbol on' d9996 1 a9996 1 'set print symbol off' d10001 1 a10001 1 'show print symbol' d10007 2 a10008 2 'set print array' 'set print array on' d10012 1 a10012 1 'set print array off' d10015 1 a10015 1 'show print array' d10019 2 a10020 2 'set print array-indexes' 'set print array-indexes on' d10026 1 a10026 1 'set print array-indexes off' d10029 1 a10029 1 'show print array-indexes' d10033 5 a10037 5 'set print nibbles' 'set print nibbles on' Print binary values in groups of four bits, known as "nibbles", when using the print command of GDB with the option '/t'. For example, this is what it looks like with 'set print nibbles on': d10044 1 a10044 1 'set print nibbles off' d10047 1 a10047 1 'show print nibbles' d10050 3 a10052 3 'set print characters NUMBER-OF-CHARACTERS' 'set print characters elements' 'set print characters unlimited' d10055 1 a10055 1 printed the number of characters set by the 'set print characters' d10057 2 a10058 2 strings, that is for strings whose character type is 'wchar_t', 'char16_t', or 'char32_t' it is the number of actual characters d10060 1 a10060 1 controls. Setting NUMBER-OF-CHARACTERS to 'elements' means that d10063 1 a10063 1 NUMBER-OF-CHARACTERS to 'unlimited' means that the number of d10065 1 a10065 1 set to 'elements'. d10067 1 a10067 1 'show print characters' d10071 2 a10072 2 'set print elements NUMBER-OF-ELEMENTS' 'set print elements unlimited' d10075 1 a10075 1 printed the number of elements set by the 'set print elements' d10078 1 a10078 1 limit is set to 200. Setting NUMBER-OF-ELEMENTS to 'unlimited' or d10082 5 a10086 5 'max-value-size' (*note max-value-size: set max-value-size.), if the 'print elements' is set such that the size of the elements being printed is less than or equal to 'max-value-size', then GDB will print the array (up to the 'print elements' limit), and only 'max-value-size' worth of data will be added into the value history d10089 1 a10089 1 'show print elements' d10093 1 a10093 1 'set print frame-arguments VALUE' d10098 1 a10098 1 'all' d10101 1 a10101 1 'scalars' d10104 1 a10104 1 unions, etc, is replaced by '...'. This is the default. Here d10110 1 a10110 1 'none' d10112 1 a10112 1 of each argument is replaced by '...'. In this case, the d10118 3 a10120 3 'presence' Only the presence of arguments is indicated by '...'. The '...' are not printed for function without any arguments. d10134 2 a10135 2 Setting 'print frame-arguments' to 'scalars' (the default), 'none' or 'presence' avoids this computation, thus speeding up the display d10138 1 a10138 1 'show print frame-arguments' d10142 1 a10142 1 'set print raw-frame-arguments on' d10145 1 a10145 1 'set print raw-frame-arguments off' d10150 1 a10150 1 'show print raw-frame-arguments' d10153 1 a10153 1 'set print entry-values VALUE' d10161 4 a10164 4 The default value is 'default' (see below for its description). Older GDB behaved as with the setting 'no'. Compilers not supporting this feature will behave in the 'default' setting the same way as with the 'no' setting. d10167 2 a10168 2 format and the compiler has to produce 'DW_TAG_call_site' tags. With GCC, you need to specify '-O -g' during compilation, to get d10173 1 a10173 1 'no' d10182 1 a10182 1 'only' d10191 1 a10191 1 'preferred' d10201 1 a10201 1 'if-needed' d10211 1 a10211 1 'both' d10221 1 a10221 1 'compact' d10224 1 a10224 1 known, print for the actual value ''. If not d10226 1 a10226 1 identical, print the shortened 'param=param@@entry=VALUE' d10234 1 a10234 1 'default' d10238 1 a10238 1 identical, print the shortened 'param=param@@entry=VALUE' d10249 1 a10249 1 'show print entry-values' d10253 1 a10253 1 'set print frame-info VALUE' d10257 2 a10258 2 that some other settings (such as 'set print frame-arguments' and 'set print address') are also influencing if and how some frame d10260 1 a10260 1 is never printed if 'set print address' is off. d10262 2 a10263 2 The possible values for 'set print frame-info' are: 'short-location' d10267 2 a10268 2 'location' Same as 'short-location' but also print the source file and d10270 2 a10271 2 'location-and-address' Same as 'location' but print the program counter even if d10273 1 a10273 1 'source-line' d10276 3 a10278 3 'source-and-location' Print what 'location' and 'source-line' are printing. 'auto' d10280 5 a10284 5 by the GDB command that prints a frame. For example, 'frame' prints the information printed by 'source-and-location' while 'stepi' will switch between 'source-line' and 'source-and-location' depending on the program counter. The default value is 'auto'. d10286 2 a10287 2 'set print repeats NUMBER-OF-REPEATS' 'set print repeats unlimited' d10290 2 a10291 2 array exceeds the threshold, GDB prints the string '""', where N is the number of identical repetitions, instead d10293 1 a10293 1 threshold to 'unlimited' or zero will cause all elements to be d10296 1 a10296 1 'show print repeats' d10300 2 a10301 2 'set print max-depth DEPTH' 'set print max-depth unlimited' d10316 1 a10316 1 how 'var' is printed by GDB: d10318 1 a10318 1 DEPTH setting Result of 'p var' d10320 6 a10325 6 unlimited '$1 = {d = {c = {b = {a = 3}}}}' '0' '$1 = {...}' '1' '$1 = {d = {...}}' '2' '$1 = {d = {c = {...}}}' '3' '$1 = {d = {c = {b = {...}}}}' '4' '$1 = {d = {c = {b = {a = 3}}}}' d10340 2 a10341 2 language, for most languages '{...}' is used, but Fortran uses '(...)'. d10343 1 a10343 1 'show print max-depth' d10347 2 a10348 2 'set print memory-tag-violations' 'set print memory-tag-violations on' d10352 1 a10352 1 'set print memory-tag-violations off' d10355 1 a10355 1 'show print memory-tag-violations' d10359 1 a10359 1 'set print null-stop' d10364 1 a10364 1 'show print null-stop' d10368 1 a10368 1 'set print pretty on' d10381 1 a10381 1 'set print pretty off' d10389 1 a10389 1 'show print pretty' d10392 1 a10392 1 'set print raw-values on' d10396 1 a10396 1 'set print raw-values off' d10403 1 a10403 1 'show print raw-values' d10406 1 a10406 1 'set print sevenbit-strings on' d10409 1 a10409 1 using the notation '\'NNN. This setting is best if you are working d10413 1 a10413 1 'set print sevenbit-strings off' d10417 1 a10417 1 'show print sevenbit-strings' d10420 1 a10420 1 'set print union on' d10424 1 a10424 1 'set print union off' d10426 1 a10426 1 other unions. GDB will print '"{...}"' instead. d10428 1 a10428 1 'show print union' d10449 1 a10449 1 with 'set print union on' in effect 'p foo' would print d10453 1 a10453 1 and with 'set print union off' in effect it would print d10457 1 a10457 1 'set print union' affects programs written in C-like languages and d10462 2 a10463 2 'set print demangle' 'set print demangle on' d10468 1 a10468 1 'show print demangle' d10471 2 a10472 2 'set print asm-demangle' 'set print asm-demangle on' d10477 1 a10477 1 'show print asm-demangle' d10481 1 a10481 1 'set demangle-style STYLE' d10487 1 a10487 1 'show demangle-style' d10491 2 a10492 2 'set print object' 'set print object on' d10502 1 a10502 1 'set print object off' d10506 1 a10506 1 'show print object' d10509 2 a10510 2 'set print static-members' 'set print static-members on' d10514 1 a10514 1 'set print static-members off' d10517 1 a10517 1 'show print static-members' d10520 2 a10521 2 'set print pascal_static-members' 'set print pascal_static-members on' d10525 1 a10525 1 'set print pascal_static-members off' d10528 1 a10528 1 'show print pascal_static-members' d10531 2 a10532 2 'set print vtbl' 'set print vtbl on' d10534 2 a10535 2 (The 'vtbl' commands do not work on programs compiled with the HP ANSI C++ compiler ('aCC').) d10537 1 a10537 1 'set print vtbl off' d10540 1 a10540 1 'show print vtbl' d10572 1 a10572 1 The 'info pretty-printer' command will list all the installed d10574 1 a10574 1 multiple data types, then its "subprinters" are the printers for the d10578 1 a10578 1 Pretty-printers are installed by "registering" them with GDB. d10585 1 a10585 1 * Pretty-printers registered globally are available when debugging d10588 1 a10588 1 * Pretty-printers registered with a program space are available only d10592 1 a10592 1 * Pretty-printers registered with an objfile are loaded and unloaded d10608 1 a10608 1 Here is how a C++ 'std::string' looks without a pretty-printer: d10624 1 a10624 1 With a pretty-printer for 'std::string' only the contents are d10636 1 a10636 1 'info pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]' d10641 1 a10641 1 pretty-printers to list. Objects can be 'global', the program d10650 1 a10650 1 'disable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]' d10655 1 a10655 1 'enable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]' d10661 3 a10663 3 named 'foo' that prints objects of type 'foo', and another from library2.so named 'bar' that prints two types of objects, 'bar1' and 'bar2'. d10706 1 a10706 1 Note that for 'bar' the entire printer can be disabled, as can each d10712 1 a10712 1 The print option '-raw-values' and GDB setting 'set print raw-values' d10716 2 a10717 2 Similarly, the backtrace option '-raw-frame-arguments' and GDB setting 'set print raw-frame-arguments' (*note set print d10727 2 a10728 2 Values printed by the 'print' command are saved in the GDB "value history". This allows you to refer to them in other expressions. d10730 1 a10730 1 example with the 'file' or 'symbol-file' commands). When the symbol d10734 3 a10736 3 The values printed are given "history numbers" by which you can refer to them. These are successive integers starting with one. 'print' shows you the history number assigned to a value by printing '$NUM = ' d10739 6 a10744 6 To refer to any previous value, use '$' followed by the value's history number. The way 'print' labels its output is designed to remind you of this. Just '$' refers to the most recent value in the history, and '$$' refers to the value before that. '$$N' refers to the Nth value from the end; '$$2' is the value just prior to '$$', '$$1' is equivalent to '$$', and '$$0' is equivalent to '$'. d10751 1 a10751 1 If you have a chain of structures where the component 'next' points d10760 1 a10760 1 of 'x' is 4 and you type these commands: d10765 2 a10766 2 then the value recorded in the value history by the 'print' command remains 4 even though the value of 'x' has changed. d10768 1 a10768 1 'show values' d10770 2 a10771 2 numbers. This is like 'p $$9' repeated ten times, except that 'show values' does not change the history. d10773 1 a10773 1 'show values N' d10776 1 a10776 1 'show values +' d10778 1 a10778 1 more values are available, 'show values +' produces no display. d10780 2 a10781 2 Pressing to repeat 'show values N' has exactly the same effect as 'show values +'. d10789 1 a10789 1 GDB provides "convenience variables" that you can use within GDB to hold d10795 2 a10796 2 Convenience variables are prefixed with '$'. Any name preceded by '$' can be used for a convenience variable, unless it is one of the d10799 1 a10799 1 preceded by '$'. *Note Value History: Value History.) d10807 2 a10808 2 would save in '$foo' the value contained in the object pointed to by 'object_ptr'. d10811 1 a10811 1 value is 'void' until you assign a new value. You can alter the value d10820 1 a10820 1 'show convenience' d10823 1 a10823 1 Abbreviated 'show conv'. d10825 1 a10825 1 'init-if-undefined $VARIABLE = EXPRESSION' d10848 2 a10849 2 '$_' The variable '$_' is automatically set by the 'x' command to the d10851 5 a10855 5 commands which provide a default address for 'x' to examine also set '$_' to that address; these commands include 'info line' and 'info breakpoint'. The type of '$_' is 'void *' except when set by the 'x' command, in which case it is a pointer to the type of '$__'. d10857 2 a10858 2 '$__' The variable '$__' is automatically set by the 'x' command to the d10862 1 a10862 1 '$_exitcode' d10865 1 a10865 1 and resets '$_exitsignal' to 'void'. d10867 1 a10867 1 '$_exitsignal' d10870 1 a10870 1 resets '$_exitcode' to 'void'. d10873 2 a10874 2 exited (i.e., '$_exitcode' is not 'void') or signalled (i.e., '$_exitsignal' is not 'void'), the convenience function '$_isvoid' d10908 3 a10910 3 debugged has signalled, since it calls 'raise' and raises a 'SIGALRM' signal. If the program being debugged had not called 'raise', then GDB would report a normal exit: d10915 2 a10916 2 '$_exception' The variable '$_exception' is set to the exception object being d10920 2 a10921 2 '$_ada_exception' The variable '$_ada_exception' is set to the address of the d10925 2 a10926 2 '$_probe_argc' '$_probe_arg0...$_probe_arg11' d10929 2 a10930 2 '$_sdata' The variable '$_sdata' contains extra collected static tracepoint d10932 1 a10932 1 that '$_sdata' could be empty, if not inspecting a trace buffer, or d10935 3 a10937 3 '$_siginfo' The variable '$_siginfo' contains extra signal information (*note extra signal information::). Note that '$_siginfo' could be empty, d10939 1 a10939 1 it will be empty before you execute the 'run' command. d10941 2 a10942 2 '$_tlb' The variable '$_tlb' is automatically set when debugging d10944 1 a10944 1 gdbserver that supports the 'qGetTIBAddr' request. *Note General d10948 1 a10948 1 '$_inferior' d10953 1 a10953 1 '$_thread' d10956 1 a10956 1 '$_gthread' d10960 1 a10960 1 '$_inferior_thread_count' d10964 2 a10965 2 '$_gdb_major' '$_gdb_minor' d10969 1 a10969 1 value 12 for '$_gdb_minor'. These variables allow you to write d10973 3 a10975 3 '$_shell_exitcode' '$_shell_exitsignal' GDB commands such as 'shell' and '|' are launching shell commands. d10977 1 a10977 1 variables '$_shell_exitcode' and '$_shell_exitsignal' according to d10979 2 a10980 2 set and used similarly to the variables '$_exitcode' and '$_exitsignal'. d10988 1 a10988 1 GDB also supplies some "convenience functions". These have a syntax d10993 1 a10993 1 These functions do not require GDB to be configured with 'Python' d10996 2 a10997 2 '$_isvoid (EXPR)' Return one if the expression EXPR is 'void'. Otherwise it returns d11000 2 a11001 2 A 'void' expression is an expression where the type of the result is 'void'. For example, you can examine a convenience variable d11003 1 a11003 1 whether it is 'void': d11017 2 a11018 2 In the example above, we used '$_isvoid' to check whether '$_exitcode' is 'void' before and after the execution of the d11020 1 a11020 1 to be examined, therefore '$_exitcode' is 'void'. After the d11022 1 a11022 1 '$_exitcode' is zero, which means that it is not 'void' anymore. d11024 1 a11024 1 The 'void' expression can also be a call of a function from the d11032 1 a11032 1 The result of calling it inside GDB is 'void': d11044 1 a11044 1 '$_gdb_setting_str (SETTING)' d11046 1 a11046 1 setting that can be used in a 'set' or 'show' command (*note d11057 1 a11057 1 '$_gdb_setting (SETTING)' d11061 11 a11071 11 The value type for boolean and auto boolean settings is 'int'. The boolean values 'off' and 'on' are converted to the integer values '0' and '1'. The value 'auto' is converted to the value '-1'. The value type for integer settings is either 'unsigned int' or 'int', depending on the setting. Some integer settings accept an 'unlimited' value. Depending on the setting, the 'set' command also accepts the value '0' or the value '-1' as a synonym for 'unlimited'. For example, 'set height unlimited' is equivalent to 'set height 0'. d11073 2 a11074 2 Some other settings that accept the 'unlimited' value use the value '0' to literally mean zero. For example, 'set history size 0' d11076 1 a11076 1 For such settings, '-1' is the synonym for 'unlimited'. d11078 2 a11079 2 See the documentation of the corresponding 'set' command for the numerical value equivalent to 'unlimited'. d11081 2 a11082 2 The '$_gdb_setting' function converts the unlimited value to a '0' or a '-1' value according to what the 'set' command uses. d11106 3 a11108 3 '$_gdb_maint_setting_str (SETTING)' Like the '$_gdb_setting_str' function, but works with 'maintenance set' variables. d11110 2 a11111 2 '$_gdb_maint_setting (SETTING)' Like the '$_gdb_setting' function, but works with 'maintenance set' d11114 1 a11114 1 '$_shell (COMMAND-STRING)' d11128 1 a11128 1 determined in the same way as for the 'shell' command. *Note Shell d11158 3 a11160 3 Note: unlike the 'shell' command, the '$_shell' convenience function does not affect the '$_shell_exitcode' and '$_shell_exitsignal' convenience variables. d11162 1 a11162 1 The following functions require GDB to be configured with 'Python' d11165 1 a11165 1 '$_memeq(BUF1, BUF2, LENGTH)' d11169 1 a11169 1 '$_regex(STR, REGEX)' d11172 1 a11172 1 that specified by 'Python''s regular expression support. d11174 1 a11174 1 '$_streq(STR1, STR2)' d11178 1 a11178 1 '$_strlen(STR)' d11181 1 a11181 1 '$_caller_is(NAME[, NUMBER_OF_FRAMES])' d11204 1 a11204 1 '$_caller_matches(REGEXP[, NUMBER_OF_FRAMES])' d11211 1 a11211 1 '$_any_caller_is(NAME[, NUMBER_OF_FRAMES])' d11218 1 a11218 1 This function differs from '$_caller_is' in that this function d11220 1 a11220 1 specified by NUMBER_OF_FRAMES, whereas '$_caller_is' only checks d11223 1 a11223 1 '$_any_caller_matches(REGEXP[, NUMBER_OF_FRAMES])' d11230 1 a11230 1 This function differs from '$_caller_matches' in that this function d11232 1 a11232 1 specified by NUMBER_OF_FRAMES, whereas '$_caller_matches' only d11235 1 a11235 1 '$_as_string(VALUE)' d11237 1 a11237 1 removed from future versions of GDB. Use the '%V' format specifier d11249 3 a11251 3 '$_cimag(VALUE)' '$_creal(VALUE)' Return the imaginary ('$_cimag') or real ('$_creal') part of the d11255 2 a11256 2 complex number, e.g., using '$_cimag' on a 'float complex' will return an imaginary part of type 'float'. d11261 1 a11261 1 'help function' d11271 2 a11272 2 with names starting with '$'. The names of registers are different for each machine; use 'info registers' to see the names used on your d11275 1 a11275 1 'info registers' d11279 1 a11279 1 'info all-registers' d11283 1 a11283 1 'info registers REGGROUP ...' d11285 2 a11286 2 REGGROUPs. The REGGROUP can be any of those returned by 'maint print reggroups' (*note Maintenance Commands::). d11288 2 a11289 2 'info registers REGNAME ...' Print the "relativized" value of each specified register REGNAME. d11293 1 a11293 1 '$'. d11298 3 a11300 3 '$pc' and '$sp' are used for the program counter register and the stack pointer. '$fp' is used for a register that contains a pointer to the current stack frame, and '$ps' is used for a register that contains the d11316 4 a11319 4 mnemonics, so long as there is no conflict. The 'info registers' command shows the canonical names. For example, on the SPARC, 'info registers' displays the processor status register as '$psr' but you can also refer to it as '$ps'; and on x86-based machines '$ps' is an alias d11327 2 a11328 2 (although you can _print_ it as a floating point value with 'print/f $REGNAME'). d11337 1 a11337 1 sense for your program), but the 'info registers' command prints the d11344 1 a11344 1 'struct' notation: d11359 1 a11359 1 'struct' member: d11368 1 a11368 1 (with 'frame 0'). d11380 1 a11380 1 GDB displays '' as the register's value. With targets that d11397 1 a11397 1 assumes that the innermost stack frame is selected; setting '$sp' is not d11399 1 a11399 1 the stack, regardless of machine architecture, use 'return'; see *note d11411 1 a11411 1 'info float' d11414 1 a11414 1 point chip. Currently, 'info float' is supported on the ARM and d11426 1 a11426 1 'info vector' d11439 1 a11439 1 Some operating systems supply an "auxiliary vector" to programs at d11447 1 a11447 1 further depend on the remote stub's support of the 'qXfer:auxv:read' d11450 1 a11450 1 'info auxv' d11464 1 a11464 1 remote stub's support of the 'qXfer:osdata:read' packet, see *note qXfer d11467 1 a11467 1 'info os INFOTYPE' d11473 1 a11473 1 'cpus' d11481 1 a11481 1 'files' d11487 1 a11487 1 'modules' d11494 1 a11494 1 'msg' d11505 1 a11505 1 'processes' d11514 1 a11514 1 'procgroups' d11524 1 a11524 1 'semaphores' d11532 1 a11532 1 'shm' d11542 1 a11542 1 'sockets' d11549 1 a11549 1 'threads' d11556 1 a11556 1 'info os' d11568 1 a11568 1 "Memory region attributes" allow you to describe special handling d11584 1 a11584 1 'mem LOWER UPPER ATTRIBUTES...' d11591 1 a11591 1 'mem auto' d11596 1 a11596 1 'delete mem NUMS...' d11600 1 a11600 1 'disable mem NUMS...' d11604 1 a11604 1 'enable mem NUMS...' d11607 1 a11607 1 'info mem' d11613 2 a11614 2 Enabled memory regions are marked with 'y'. Disabled memory regions are marked with 'n'. d11640 1 a11640 1 'ro' d11642 1 a11642 1 'wo' d11644 1 a11644 1 'rw' d11655 1 a11655 1 '8' d11657 1 a11657 1 '16' d11659 1 a11659 1 '32' d11661 1 a11661 1 '64' d11672 1 a11672 1 'cache' d11674 1 a11674 1 'nocache' d11685 2 a11686 2 'set mem inaccessible-by-default [on|off]' If 'on' is specified, make GDB treat memory not explicitly d11689 1 a11689 1 one memory range defined. If 'off' is specified, make GDB treat d11691 2 a11692 2 The default value is 'on'. 'show mem inaccessible-by-default' d11701 3 a11703 3 You can use the commands 'dump', 'append', and 'restore' to copy data between target memory and a file. The 'dump' and 'append' commands write data to a file, and the 'restore' command reads data from a file d11708 2 a11709 2 'dump [FORMAT] memory FILENAME START_ADDR END_ADDR' 'dump [FORMAT] value FILENAME EXPR' d11714 1 a11714 1 'binary' d11716 1 a11716 1 'ihex' d11718 1 a11718 1 'srec' d11720 1 a11720 1 'tekhex' d11722 1 a11722 1 'verilog' d11726 1 a11726 1 utilities, like 'objdump' and 'objcopy'. If FORMAT is omitted, GDB d11729 2 a11730 2 'append [binary] memory FILENAME START_ADDR END_ADDR' 'append [binary] value FILENAME EXPR' d11735 2 a11736 2 'restore FILENAME [binary] BIAS START END' Restore the contents of file FILENAME into memory. The 'restore' d11739 1 a11739 1 specify the optional keyword 'binary' after the filename. d11758 1 a11758 1 A "core file" or "core dump" is a file that records the memory image of d11769 2 a11770 2 'generate-core-file [FILE]' 'gcore [FILE]' d11773 1 a11773 1 specified, the file name defaults to 'core.PID', where PID is the d11783 1 a11783 1 file '/proc/PID/coredump_filter' when generating the core dump d11785 2 a11786 2 'VM_DONTDUMP' flag for mappings where it is present in the file '/proc/PID/smaps' (*note set dump-excluded-mappings::). d11788 3 a11790 3 'set use-coredump-filter on' 'set use-coredump-filter off' Enable or disable the use of the file '/proc/PID/coredump_filter' d11797 1 a11797 1 '/proc/PID/coredump_filter' file a value, in hexadecimal, which is d11803 2 a11804 2 '/proc/PID/coredump_filter' file, please refer to the manpage of 'core(5)'. d11806 2 a11807 2 By default, this option is 'on'. If this option is turned 'off', GDB does not read the 'coredump_filter' file and instead uses the d11810 3 a11812 3 currently '0x33', which means that bits '0' (anonymous private mappings), '1' (anonymous shared mappings), '4' (ELF headers) and '5' (private huge pages) are active. This will cause these memory d11815 5 a11819 5 'set dump-excluded-mappings on' 'set dump-excluded-mappings off' If 'on' is specified, GDB will dump memory mappings marked with the 'VM_DONTDUMP' flag. This flag is represented in the file '/proc/PID/smaps' with the acronym 'dd'. d11821 1 a11821 1 The default value is 'off'. d11832 2 a11833 2 character set GDB uses we call the "host character set"; the one the inferior program uses we call the "target character set". d11840 1 a11840 1 the command 'set target-charset EBCDIC-US', then GDB translates between d11845 1 a11845 1 inferior program uses; you must tell it, using the 'set target-charset' d11850 1 a11850 1 'set target-charset CHARSET' d11853 1 a11853 1 'set target-charset '. d11855 1 a11855 1 'set host-charset CHARSET' d11859 2 a11860 2 it is running on; you can override that default using the 'set host-charset' command. On some systems, GDB cannot automatically d11862 1 a11862 1 uses 'UTF-8'. d11865 1 a11865 1 If you type 'set host-charset ', GDB will list the host d11868 1 a11868 1 'set charset CHARSET' d11870 1 a11870 1 above, if you type 'set charset ', GDB will list the d11874 1 a11874 1 'show charset' d11877 1 a11877 1 'show host-charset' d11880 1 a11880 1 'show target-charset' d11883 1 a11883 1 'set target-wide-charset CHARSET' d11885 1 a11885 1 the character set used by the target's 'wchar_t' type. To display d11887 1 a11887 1 'set target-wide-charset '. d11889 1 a11889 1 'show target-wide-charset' d11894 1 a11894 1 'charset-test.c': d11910 2 a11911 2 In this program, 'ascii_hello' and 'ibm1047_hello' are arrays containing the string 'Hello, world!' followed by a newline, encoded in d11923 1 a11923 1 We can use the 'show charset' command to see what character sets GDB d11941 1 a11941 1 contents of 'ascii_hello' print legibly: d11956 1 a11956 1 The ASCII character set uses the number 43 to encode the '+' d11960 1 a11960 1 program uses. If we print 'ibm1047_hello' while our target character d11969 1 a11969 1 If we invoke the 'set target-charset' followed by , GDB d11978 1 a11978 1 translates the contents of 'ibm1047_hello' from the target character d12003 1 a12003 1 The IBM1047 character set uses the number 78 to encode the '+' d12026 2 a12027 2 'set remotecache on' 'set remotecache off' d12031 1 a12031 1 'show remotecache' d12034 4 a12037 4 'set stack-cache on' 'set stack-cache off' Enable or disable caching of stack accesses. When 'on', use caching. By default, this option is 'on'. d12039 1 a12039 1 'show stack-cache' d12042 4 a12045 4 'set code-cache on' 'set code-cache off' Enable or disable caching of code segment accesses. When 'on', use caching. By default, this option is 'on'. This improves d12048 1 a12048 1 'show code-cache' d12052 1 a12052 1 'info dcache [line]' d12062 1 a12062 1 'set dcache size SIZE' d12065 1 a12065 1 'set dcache line-size LINE-SIZE' d12069 1 a12069 1 'show dcache size' d12073 1 a12073 1 'show dcache line-size' d12076 1 a12076 1 'maint flush dcache' d12094 1 a12094 1 'find' command. d12096 2 a12097 2 'find [/SN] START_ADDR, +LEN, VAL1 [, VAL2, ...]' 'find [/SN] START_ADDR, END_ADDR, VAL1 [, VAL2, ...]' d12108 1 a12108 1 'b' d12110 1 a12110 1 'h' d12112 1 a12112 1 'w' d12114 1 a12114 1 'g' d12121 1 a12121 1 '{char[5]}"hello"'. d12127 1 a12127 1 for an untyped 0x42 will search for '(int) 0x42' which is typically d12135 1 a12135 1 ('"'). The string value is copied into the search pattern byte by byte, d12142 1 a12142 1 '$_'. A count of the number of matches is stored in '$numfound'. d12144 1 a12144 1 For example, if stopped at the 'printf' in this function: d12192 2 a12193 2 'set max-value-size BYTES' 'set max-value-size unlimited' d12201 1 a12201 1 There's a minimum size that 'max-value-size' can be set to in order d12207 1 a12207 1 simple integer component, such as 'x.y.z', may fail if the size of d12209 1 a12209 1 sometimes clever; the expression 'A[i]', where A is an array d12214 1 a12214 1 The default value of 'max-value-size' is currently 64k. d12216 1 a12216 1 'show max-value-size' d12239 1 a12239 1 When you debug a program compiled with '-g -O', remember that the d12246 1 a12246 1 Some things do not work as well with '-g -O' as with just '-g', d12248 1 a12248 1 recompile with '-g' alone, and if this fixes the problem, please report d12263 1 a12263 1 "Inlining" is an optimization that inserts a copy of the function body d12267 3 a12269 3 into them with 'step', skip them with 'next', and escape from them with 'finish'. You can check whether a function was inlined by using the 'info frame' command. d12275 2 a12276 2 4.1 do not emit two required attributes ('DW_AT_call_file' and 'DW_AT_call_line'); GDB does not display inlined function calls with d12289 1 a12289 1 single instruction using 'stepi' or 'nexti' does not do this; single d12295 1 a12295 1 * Setting breakpoints at the call site of an inlined function may not d12302 3 a12304 3 * GDB cannot locate the return value of inlined calls after using the 'finish' command. This is a limitation of compiler-generated debugging information; after 'finish', you can step to the next d12314 13 a12326 13 Function 'B' can call function 'C' in its very last statement. In unoptimized compilation the call of 'C' is immediately followed by return instruction at the end of 'B' code. Optimizing compiler may replace the call and return in function 'B' into one jump to function 'C' instead. Such use of a jump instruction is called "tail call". During execution of function 'C', there will be no indication in the function call stack frames that it was tail-called from 'B'. If function 'A' regularly calls function 'B' which tail-calls function 'C', then GDB will see 'A' as the caller of 'C'. However, in some cases GDB can determine that 'C' was tail-called from 'B', and it will then create fictitious call frame for that, with the return address set up as if 'B' called 'C' normally. d12329 2 a12330 2 format and the compiler has to produce 'DW_TAG_call_site' tags. With GCC, you need to specify '-O -g' during compilation, to get this d12333 2 a12334 2 'info frame' command (*note Frame Info::) will indicate the tail call frame kind by text 'tail call frame' such as in this sample GDB output: d12354 1 a12354 1 'set debug entry-values' d12362 1 a12362 1 'show debug entry-values' d12367 2 a12368 2 virtual tail call frame for function 'c' has not been recognized (due to the indirect reference by variable 'x'): d12406 2 a12407 2 can have possible execution paths 'main->a->b->c->d->f' or 'main->a->b->e->f', GDB cannot find which one from the inferior state. d12409 1 a12409 1 'initial:' state shows some random possible calling sequence GDB has d12411 3 a12413 3 prefixed by 'compare:'. The non-ambiguous intersection of these two is printed as the 'reduced:' calling sequence. That one could have many further 'compare:' and 'reduced:' statements as long as there remain any d12416 2 a12417 2 For the frame of function 'b' in both cases there are different possible '$pc' values ('0x4004cc' or '0x4004ce'), therefore this frame d12419 1 a12419 1 'a', therefore this one is displayed to the user while the ambiguous d12441 2 a12442 2 function 'a' call itself (via function 'b') as these calls would be tail calls. Such tail calls would modify the 'i' variable, therefore GDB d12444 1 a12444 1 '' instead. d12461 1 a12461 1 '-g' flag. *Note Compilation::. d12475 2 a12476 2 'macro expand EXPRESSION' 'macro exp EXPRESSION' d12482 2 a12483 2 'macro expand-once EXPRESSION' 'macro exp1 EXPRESSION' d12493 1 a12493 1 'info macro [-a|-all] [--] MACRO' d12500 1 a12500 1 'info macros LOCSPEC' d12506 2 a12507 2 'macro define MACRO REPLACEMENT-LIST' 'macro define MACRO(ARGLIST) REPLACEMENT-LIST' d12516 2 a12517 2 expression evaluated in GDB, until it is removed with the 'macro undef' command, described below. The definition overrides all d12521 1 a12521 1 'macro undef MACRO' d12523 2 a12524 2 This command only affects definitions provided with the 'macro define' command, described above; it cannot remove definitions d12527 2 a12528 2 'macro list' List all the macros defined using the 'macro define' command. d12554 1 a12554 1 the '-gdwarf-2'(1) _and_ '-g3' flags to ensure the compiler includes d12596 1 a12596 1 In the example above, note that 'macro expand-once' expands only the d12598 2 a12599 2 'ADD' -- but does not expand the invocation of the macro 'M', which was introduced by 'ADD'. d12613 1 a12613 1 At line 10, the definition of the macro 'N' at line 9 is in force: d12624 1 a12624 1 As we step over directives that remove 'N''s definition, and then d12647 1 a12647 1 command line using the '-DNAME=VALUE' syntax. For macros defined in d12658 2 a12659 2 (1) This is the minimum. Recent versions of GCC support '-gdwarf-3' and '-gdwarf-4'; we recommend always choosing the most recent version of d12676 3 a12678 3 Using GDB's 'trace' and 'collect' commands, you can specify locations in the program, called "tracepoints", and arbitrary expressions to evaluate when those tracepoints are reached. Later, using the 'tfind' d12695 1 a12695 1 reminiscent of corefiles; you specify the filename, and use 'tfind' to d12713 1 a12713 1 Before running such a "trace experiment", an arbitrary number of d12731 1 a12731 1 Some targets may support "fast tracepoints", which are inserted in a d12737 3 a12739 3 the target. Some targets may also support controlling "static tracepoints" from GDB. With static tracing, a set of instrumentation points, also known as "markers", are embedded in the target program, and d12749 1 a12749 1 referred to as "probing" a static tracepoint marker. d12751 2 a12752 2 'gdbserver' supports tracepoints on some target systems. *Note Tracepoints support in 'gdbserver': Server. d12776 2 a12777 2 'trace LOCSPEC' The 'trace' command is very similar to the 'break' command. Its d12779 1 a12779 1 Location Specifications::. The 'trace' command defines a d12784 3 a12786 3 'InstallInTrace' feature (*note install tracepoint in tracing::). If remote stub doesn't support the 'InstallInTrace' feature, all these changes don't take effect until the next 'tstart' command, d12789 1 a12789 1 addition, GDB supports "pending tracepoints"--tracepoints whose d12798 1 a12798 1 Here are some examples of using the 'trace' command: d12810 1 a12810 1 You can abbreviate 'trace' as 'tr'. d12812 1 a12812 1 'trace LOCSPEC if COND' d12819 2 a12820 2 'ftrace LOCSPEC [ if COND ]' The 'ftrace' command sets a fast tracepoint. For targets that d12828 1 a12828 1 GDB handles arguments to 'ftrace' exactly as for 'trace'. d12836 2 a12837 2 is possible to let GDB use this area by doing a 'sysctl' command to set the 'mmap_min_addr' kernel parameter, as in d12844 2 a12845 2 'strace [LOCSPEC | -m MARKER] [ if COND ]' The 'strace' command sets a static tracepoint. For targets that d12852 2 a12853 2 GDB handles arguments to 'strace' exactly as for 'trace', with the addition that the user can also specify '-m MARKER' instead of a d12857 2 a12858 2 the marker identifiers in the 'ID' field of the 'info static-tracepoint-markers' command output. *Note Listing Static d12869 1 a12869 1 'trace_mark' call with a slash, which translates to: d12881 2 a12882 2 Static tracepoints accept an extra collect action -- 'collect $_sdata'. This collects arbitrary user data passed in the probe d12884 1 a12884 1 you'll see that the third argument to 'trace_mark' is a printf-like d12886 3 a12888 3 formatting string against the following arguments. Note that 'info static-tracepoint-markers' command output lists that format string in the 'Data:' field. d12894 1 a12894 1 The convenience variable '$tpnum' records the tracepoint number of d12897 1 a12897 1 'delete tracepoint [NUM]' d12900 1 a12900 1 'delete' command can remove tracepoints also. d12908 1 a12908 1 You can abbreviate this command as 'del tr'. d12916 2 a12917 2 These commands are deprecated; they are equivalent to plain 'disable' and 'enable'. d12919 1 a12919 1 'disable tracepoint [NUM]' d12923 1 a12923 1 tracepoint using the 'enable tracepoint' command. If the command d12929 1 a12929 1 'enable tracepoint [NUM]' d12942 2 a12943 2 'passcount [N [NUM]]' Set the "passcount" of a tracepoint. The passcount is a way to d12947 1 a12947 1 is not specified, the 'passcount' command sets the passcount of the d12975 1 a12975 1 reaches a specified place. You can also specify a "condition" for a d12982 1 a12982 1 using 'if' in the arguments to the 'trace' command. *Note Setting d12984 1 a12984 1 changed at any time with the 'condition' command, just as with d13008 1 a13008 1 A "trace state variable" is a special type of variable that is created d13012 1 a13012 1 'tvariable' command. They are always 64-bit signed integers. d13024 1 a13024 1 state variables with names like '$23' or '$pc', nor can you have a trace d13027 3 a13029 3 'tvariable $NAME [ = EXPRESSION ]' The 'tvariable' command creates a new trace state variable named '$NAME', and optionally gives it an initial value of EXPRESSION. d13032 1 a13032 1 will report an error. A subsequent 'tvariable' command specifying d13038 1 a13038 1 'info tvariables' d13043 1 a13043 1 'delete tvariable [ $NAME ... ]' d13053 1 a13053 1 'actions [NUM]' d13057 1 a13057 1 defined (so that you can define a tracepoint and then say 'actions' d13060 3 a13062 3 terminate the actions list with a line containing just 'end'. So far, the only defined actions are 'collect', 'teval', and 'while-stepping'. d13064 1 a13064 1 'actions' is actually equivalent to 'commands' (*note Breakpoint d13068 2 a13069 2 To remove all actions from a tracepoint, type 'actions NUM' and follow it immediately with 'end'. d13077 1 a13077 1 In the following example, the action list begins with 'collect' d13080 1 a13080 1 following the tracepoint, a 'while-stepping' command is used, d13082 3 a13084 3 sequence of single steps. The 'while-stepping' command is terminated by its own separate 'end' command. Lastly, the action list is terminated by an 'end' command. d13096 1 a13096 1 'collect[/MODS] EXPR1, EXPR2, ...' d13102 1 a13102 1 '$regs' d13105 1 a13105 1 '$args' d13108 1 a13108 1 '$locals' d13111 1 a13111 1 '$_ret' d13123 1 a13123 1 '$_probe_argc' d13127 1 a13127 1 '$_probe_argN' d13132 1 a13132 1 '$_sdata' d13136 1 a13136 1 library backend, an instrumentation point resembles a 'printf' d13146 3 a13148 3 In this case, collecting '$_sdata' collects the string 'hello $yourname'. When analyzing the trace buffer, you can inspect '$_sdata' like any other variable available to GDB. d13150 2 a13151 2 You can give several consecutive 'collect' commands, each one with a single argument, or one 'collect' command with several arguments d13154 1 a13154 1 The optional MODS changes the usual handling of the arguments. 's' d13158 1 a13158 1 the 'print characters' variable; if 's' is followed by a decimal d13160 1 a13160 1 'collect/s25 mystr' collects as many as 25 characters at 'mystr'. d13162 1 a13162 1 The command 'info scope' (*note info scope: Symbols.) is d13165 1 a13165 1 'teval EXPR1, EXPR2, ...' d13171 1 a13171 1 the 'collect' action were used. d13173 1 a13173 1 'while-stepping N' d13175 1 a13175 1 collecting new data after each step. The 'while-stepping' command d13177 1 a13177 1 by its own 'end' command): d13184 1 a13184 1 Note that '$pc' is not automatically collected by 'while-stepping'; d13186 1 a13186 1 may abbreviate 'while-stepping' as 'ws' or 'stepping'. d13188 1 a13188 1 'set default-collect EXPR1, EXPR2, ...' d13190 1 a13190 1 tracepoint hit. It is effectively an additional 'collect' action d13193 1 a13193 1 named 'xyz' may be interpreted as a global for one tracepoint, and d13196 1 a13196 1 'show default-collect' d13206 1 a13206 1 'info tracepoints [NUM...]' d13209 2 a13210 2 defined so far. The format is similar to that used for 'info breakpoints'; in fact, 'info tracepoints' is the same command, d13216 1 a13216 1 * its passcount as given by the 'passcount N' command d13218 1 a13218 1 * the state about installed on target of each location d13240 1 a13240 1 This command can be abbreviated 'info tp'. d13248 1 a13248 1 'info static-tracepoint-markers' d13260 1 a13260 1 Probed markers are tagged with 'y'. 'n' identifies marks that d13295 1 a13295 1 'tstart' d13305 1 a13305 1 'tstop' d13316 1 a13316 1 'tstatus' d13336 1 a13336 1 such as 'detach', the debugger will ask what you want to do with the d13339 1 a13339 1 'disconnected-tracing' lets you decide whether the trace should continue d13342 2 a13343 2 'set disconnected-tracing on' 'set disconnected-tracing off' d13345 1 a13345 1 disconnected from the target. Note that 'detach' or 'quit' will d13350 1 a13350 1 'show disconnected-tracing' d13369 1 a13369 1 If your target agent supports a "circular trace buffer", then you can d13375 1 a13375 1 ask for a circular trace buffer, simply set 'circular-trace-buffer' to d13380 2 a13381 2 'set circular-trace-buffer on' 'set circular-trace-buffer off' d13388 1 a13388 1 'show circular-trace-buffer' d13394 2 a13395 2 'set trace-buffer-size N' 'set trace-buffer-size unlimited' d13399 1 a13399 1 'unlimited' or '-1' to let the target use whatever size it likes. d13402 1 a13402 1 'show trace-buffer-size' d13408 1 a13408 1 starts. Use 'tstatus' to get a report of the actual buffer size. d13410 1 a13410 1 'set trace-user TEXT' d13412 1 a13412 1 'show trace-user' d13414 1 a13414 1 'set trace-notes TEXT' d13417 1 a13417 1 'show trace-notes' d13420 1 a13420 1 'set trace-stop-notes TEXT' d13422 1 a13422 1 'tstop' arguments; the set command is convenient way to fix a stop d13425 1 a13425 1 'show trace-stop-notes' d13442 1 a13442 1 * Tracepoint expressions are intended to gather objects (lvalues). d13450 2 a13451 2 * Collection of local variables, either individually or in bulk with '$locals' or '$args', during 'while-stepping' may behave d13458 1 a13458 1 where the steps of a 'while-stepping' sequence will advance the d13461 1 a13461 1 * Collection of an incompletely-initialized or partially-destroyed d13465 1 a13465 1 * When GDB displays a pointer to character it automatically d13471 2 a13472 2 example, '*ptr@@50' can be used to collect the 50 element array pointed to by 'ptr'. d13474 1 a13474 1 * It is not possible to collect a complete stack backtrace at a d13477 1 a13477 1 '*(unsigned char *)$esp@@300' (adjust to use the name of the actual d13479 1 a13479 1 of stack you wish to capture). Then the 'backtrace' command will d13486 2 a13487 2 * If you do not collect registers at a tracepoint, GDB can infer that the value of '$pc' must be the same as the address of the d13491 2 a13492 2 was inlined), or if it has a 'while-stepping' loop. In those cases GDB will warn you that it can't infer '$pc', and default it to d13503 1 a13503 1 "snapshot" every time it is hit and another snapshot every time it d13506 1 a13506 1 examine them is to "focus" on a specific trace snapshot. When the d13511 1 a13511 1 ('print', 'info registers', 'backtrace', etc.) will behave as if we d13524 1 a13524 1 13.2.1 'tfind N' d13528 1 a13528 1 'tfind N', which finds trace snapshot number N, counting from zero. If d13531 1 a13531 1 Here are the various forms of using the 'tfind' command. d13533 1 a13533 1 'tfind start' d13535 1 a13535 1 'tfind 0' (since 0 is the number of the first snapshot). d13537 1 a13537 1 'tfind none' d13540 2 a13541 2 'tfind end' Same as 'tfind none'. d13543 1 a13543 1 'tfind' d13547 1 a13547 1 'tfind -' d13551 1 a13551 1 'tfind tracepoint NUM' d13557 1 a13557 1 'tfind pc ADDR' d13563 1 a13563 1 'tfind outside ADDR1, ADDR2' d13567 1 a13567 1 'tfind range ADDR1, ADDR2' d13571 1 a13571 1 'tfind line [FILE:]N' d13576 2 a13577 2 other than the one currently being examined; thus saying 'tfind line' repeatedly can appear to have the same effect as stepping d13580 1 a13580 1 The default arguments for the 'tfind' commands are specifically d13582 4 a13585 4 instance, 'tfind' with no argument selects the next trace snapshot, and 'tfind -' with no argument selects the previous trace snapshot. So, by giving one 'tfind' command, and then simply hitting repeatedly you can examine all the trace snapshots in order. Or, by saying 'tfind -' d13587 2 a13588 2 reverse order. The 'tfind line' command with no argument selects the snapshot for the next source line executed. The 'tfind pc' command with d13590 1 a13590 1 as the current frame. The 'tfind tracepoint' command with no argument d13619 1 a13619 1 Or, if we want to examine the variable 'X' at each source line in the d13635 1 a13635 1 13.2.2 'tdump' d13688 2 a13689 2 'tdump' works by scanning the tracepoint's current collection actions and printing the value of each expression listed. So 'tdump' can fail, d13693 2 a13694 2 Also, for tracepoints with 'while-stepping' loops, 'tdump' uses the collected value of '$pc' to distinguish between trace frames that were d13698 1 a13698 1 while-stepping loop. However, if '$pc' was not collected, then 'tdump' d13706 1 a13706 1 13.2.3 'save tracepoints FILENAME' d13710 1 a13710 1 their actions and passcounts, into a file 'FILENAME' suitable for use in d13712 2 a13713 2 use the 'source' command (*note Command Files::). The 'save-tracepoints' command is a deprecated alias for 'save tracepoints' d13721 2 a13722 2 '(int) $trace_frame' The current trace snapshot (a.k.a. "frame") number, or -1 if no d13725 1 a13725 1 '(int) $tracepoint' d13728 1 a13728 1 '(int) $trace_line' d13731 1 a13731 1 '(char []) $trace_file' d13734 2 a13735 2 '(char []) $trace_func' The name of the function containing '$tracepoint'. d13737 1 a13737 1 Note: '$trace_file' is not suitable for use in 'printf', use 'output' d13763 1 a13763 1 data, via the 'target tfile' command. d13765 2 a13766 2 'tsave [ -r ] FILENAME' 'tsave [-ctf] DIRNAME' d13771 1 a13771 1 '-r' ("remote") to direct the target to save the data directly into d13773 1 a13773 1 trace buffer is very large. (Note, however, that 'target tfile' d13776 2 a13777 2 optional argument '-ctf' to save data in CTF format. The "Common Trace Format" (CTF) is proposed as a trace format that can be d13779 1 a13779 1 'http://www.efficios.com/ctf' to get more information. d13781 2 a13782 2 'target tfile FILENAME' 'target ctf DIRNAME' d13786 1 a13786 1 experiments. 'tstatus' will report the state of the trace run at d13812 1 a13812 1 memory, you can sometimes use "overlays" to work around this problem. d13837 1 a13837 1 these modules "overlays". Separate the overlays from the main program, d13883 1 a13883 1 a "mapped" overlay; its "mapped address" is its address in the d13885 1 a13885 1 in instruction memory is called "unmapped"; its "load address" is its d13887 2 a13888 2 "virtual memory address", or "VMA"; the load address is also called the "load memory address", or "LMA". d13894 1 a13894 1 * Before calling or returning to a function in an overlay, your d13899 1 a13899 1 * If the process of mapping an overlay is expensive on your system, d13903 1 a13903 1 * The executable file you load onto your system must contain each d13911 1 a13911 1 * The procedure for loading executable files onto your system must be d13918 1 a13918 1 * If your system has suitable bank switch registers or memory d13924 1 a13924 1 * If your overlays are small enough, you could set aside more than d13927 1 a13927 1 * You can use overlays to manage data, as well as instructions. In d13949 2 a13950 2 GDB's overlay commands all start with the word 'overlay'; you can abbreviate this as 'ov' or 'ovly'. The commands are: d13952 1 a13952 1 'overlay off' d13958 2 a13959 2 'overlay manual' Enable "manual" overlay debugging. In this mode, GDB relies on you d13961 1 a13961 1 'overlay map-overlay' and 'overlay unmap-overlay' commands d13964 2 a13965 2 'overlay map-overlay OVERLAY' 'overlay map OVERLAY' d13973 2 a13974 2 'overlay unmap-overlay OVERLAY' 'overlay unmap OVERLAY' d13980 2 a13981 2 'overlay auto' Enable "automatic" overlay debugging. In this mode, GDB consults a d13986 2 a13987 2 'overlay load-target' 'overlay load' d13994 2 a13995 2 'overlay list-overlays' 'overlay list' d14006 1 a14006 1 around them. For example, if 'foo' is a function in an unmapped d14013 1 a14013 1 When 'foo''s overlay is mapped, GDB prints the function's name normally: d14023 1 a14023 1 mapped. This allows most GDB commands, like 'break' and 'disassemble', d14027 1 a14027 1 * You can set breakpoints in functions in unmapped overlays, as long d14029 1 a14029 1 * GDB can not set hardware or simulator-based breakpoints in unmapped d14043 1 a14043 1 If you enable automatic overlay debugging with the 'overlay auto' d14050 1 a14050 1 '_ovly_table': d14069 1 a14069 1 '_novlys': d14071 1 a14071 1 number of elements in '_ovly_table'. d14074 1 a14074 1 for an entry in '_ovly_table' whose 'vma' and 'lma' members equal the d14076 1 a14076 1 finds a matching entry, it consults the entry's 'mapped' member to d14080 1 a14080 1 '_ovly_debug_event'. If this function is defined, GDB will silently set d14105 1 a14105 1 'gdb/testsuite/gdb.base': d14107 1 a14107 1 'overlays.c' d14109 11 a14119 11 'ovlymgr.c' A simple overlay manager, used by 'overlays.c'. 'foo.c' 'bar.c' 'baz.c' 'grbx.c' Overlay modules, loaded and used by 'overlays.c'. 'd10v.ld' 'm32r.ld' Linker scripts for linking the test program on the 'd10v-elf' and 'm32r-elf' targets. d14121 1 a14121 1 You can build the test program using the 'd10v-elf' GCC d14135 1 a14135 1 the target system for 'd10v-elf-gcc' and 'd10v.ld'. d14145 4 a14148 4 dereferencing a pointer 'p' is accomplished by '*p', but in Modula-2, it is accomplished by 'p^'. Values can also be represented (and displayed) differently. Hex numbers in C appear as '0x1ae', while in Modula-2 they appear as '1AEH'. d14154 1 a14154 1 language you use to build expressions is called the "working language". d14171 2 a14172 2 it automatically, or select it manually yourself. You can use the 'set language' command for either purpose. On startup, GDB defaults to d14182 1 a14182 1 demangled--this way 'backtrace' can show each frame appropriately for d14188 2 a14189 2 'cfront' or 'f2c', that generates C but is written in another language. In that case, make the program use '#line' directives in its C output; d14209 4 a14212 4 '.ada' '.ads' '.adb' '.a' d14215 1 a14215 1 '.c' d14218 6 a14223 6 '.C' '.cc' '.cp' '.cpp' '.cxx' '.c++' d14226 1 a14226 1 '.d' d14229 1 a14229 1 '.m' d14232 2 a14233 2 '.f' '.F' d14236 1 a14236 1 '.mod' d14239 2 a14240 2 '.s' '.S' d14257 3 a14259 3 the command 'set language LANG', where LANG is the name of a language, such as 'c' or 'modula-2'. For a list of the supported languages, type 'set language'. d14270 4 a14273 4 might not have the effect you intended. In C, this means to add 'b' and 'c' and place the result in 'a'. The result printed would be the value of 'a'. In Modula-2, this means to compare 'a' to the result of 'b+c', yielding a 'BOOLEAN' value. d14281 2 a14282 2 To have GDB set the working language automatically, use 'set language local' or 'set language auto'. GDB then infers the working language. d14293 1 a14293 1 a different source language. Using 'set language auto' in this case d14305 1 a14305 1 'show language' d14307 1 a14307 1 use with commands such as 'print' to build and compute expressions d14310 1 a14310 1 'info frame' d14316 1 a14316 1 'info source' d14325 1 a14325 1 'set extension-language EXT LANGUAGE' d14329 1 a14329 1 'info extensions' d14349 1 a14349 1 evaluation via the 'print' command, for example. d14375 1 a14375 1 The second example fails because in C++ the integer constant '0x1234' d14385 1 a14385 1 does not know how to add an 'int' and a 'struct foo'. These particular d14391 2 a14392 2 'set check type on' 'set check type off' d14397 1 a14397 1 'show check type' d14425 1 a14425 1 M + 1 => S d14435 1 a14435 1 'set check range auto' d14440 2 a14441 2 'set check range on' 'set check range off' d14448 1 a14448 1 'set check range warn' d14455 1 a14455 1 'show check range' d14467 2 a14468 2 expressions regardless of the language you use: the GDB '@@' and '::' operators, and the '{type}addr' construct (*note Expressions: d14505 1 a14505 1 GNU 'g++', or the HP ANSI C++ compiler ('aCC'). d14525 1 a14525 1 '+' is defined on numbers, but not on structures. Operators are often d14530 2 a14531 2 * _Integral types_ include 'int' with any of its storage-class specifiers; 'char'; 'enum'; and, for C++, 'bool'. d14533 1 a14533 1 * _Floating-point types_ include 'float', 'double', and 'long double' d14536 1 a14536 1 * _Pointer types_ include all types defined as '(TYPE *)'. d14538 1 a14538 1 * _Scalar types_ include all of the above. d14543 1 a14543 1 ',' d14548 1 a14548 1 '=' d14552 5 a14556 5 'OP=' Used in an expression of the form 'A OP= B', and translated to 'A = A OP B'. 'OP=' and '=' have the same precedence. The operator OP is any one of the operators '|', '^', '&', '<<', '>>', '+', '-', '*', '/', '%'. d14558 2 a14559 2 '?:' The ternary operator. 'A ? B : C' can be thought of as: if A then d14562 1 a14562 1 '||' d14565 1 a14565 1 '&&' d14568 1 a14568 1 '|' d14571 1 a14571 1 '^' d14574 1 a14574 1 '&' d14577 1 a14577 1 '==, !=' d14581 1 a14581 1 '<, >, <=, >=' d14586 1 a14586 1 '<<, >>' d14589 1 a14589 1 '@@' d14593 1 a14593 1 '+, -' d14597 1 a14597 1 '*, /, %' d14602 1 a14602 1 '++, --' d14608 1 a14608 1 '*' d14610 1 a14610 1 as '++'. d14612 2 a14613 2 '&' Address operator. Defined on variables. Same precedence as '++'. d14615 2 a14616 2 For debugging C++, GDB implements a use of '&' beyond what is allowed in the C++ language itself: you can use '&(&REF)' to d14618 1 a14618 1 '&REF') is stored. d14620 1 a14620 1 '-' d14622 1 a14622 1 precedence as '++'. d14624 1 a14624 1 '!' d14626 1 a14626 1 '++'. d14628 1 a14628 1 '~' d14630 1 a14630 1 precedence as '++'. d14632 1 a14632 1 '., ->' d14636 1 a14636 1 Defined on 'struct' and 'union' data. d14638 1 a14638 1 '.*, ->*' d14641 10 a14650 10 '[]' Array indexing. 'A[I]' is defined as '*(A+I)'. Same precedence as '->'. '()' Function parameter list. Same precedence as '->'. '::' C++ scope resolution operator. Defined on 'struct', 'union', and 'class' types. d14652 1 a14652 1 '::' d14654 1 a14654 1 Expressions: Expressions.). Same precedence as '::', above. d14669 4 a14672 4 * Integer constants are a sequence of digits. Octal constants are specified by a leading '0' (i.e. zero), and hexadecimal constants by a leading '0x' or '0X'. Constants may also end with a letter 'l', specifying that the constant should be treated as a 'long' d14675 1 a14675 1 * Floating point constants are a sequence of digits, followed by a d14678 1 a14678 1 'e[[+]|-]NNN', where NNN is another sequence of digits. The '+' is d14680 4 a14683 4 also end with a letter 'f' or 'F', specifying that the constant should be treated as being of the 'float' (as opposed to the default 'double') type; or with a letter 'l' or 'L', which specifies a 'long double' constant. d14685 1 a14685 1 * Enumerated constants consist of enumerated identifiers, or their d14688 2 a14689 2 * Character constants are a single character surrounded by single quotes ('''), or a number--the ordinal value of the corresponding d14691 4 a14694 4 character may be represented by a letter or by "escape sequences", which are of the form '\NNN', where NNN is the octal representation of the character's ordinal value; or of the form '\X', where 'X' is a predefined special character--for example, '\n' for newline. d14697 2 a14698 2 constant with 'L', as in C. For example, 'L'x'' is the wide form of 'x'. The target wide character set is used when computing the d14701 2 a14702 2 * String constants are a sequence of character constants surrounded by double quotes ('"'). Any valid character constant (as described d14704 1 a14704 1 preceded by a backslash, so for instance '"a\"b'c"' is a string of d14708 1 a14708 1 with 'L', as in C. The target wide character set is used when d14711 2 a14712 2 * Pointer constants are an integral value. You can also write pointers to constants using the C operator '&'. d14714 4 a14717 4 * Array constants are comma-separated lists surrounded by braces '{' and '}'; for example, '{1,2,3}' is a three-element array of integers, '{{1,2}, {3,4}, {5,6}}' is a three-by-two array, and '{&"hi", &"there", &"fred"}' is a three-element array of pointers. d14742 1 a14742 1 instance pointer 'this' following the same rules as C++. 'using' d14759 1 a14759 1 'set overload-resolution off'. *Note GDB Features for C++: d14762 1 a14762 1 You must specify 'set overload-resolution off' in order to use an d14777 1 a14777 1 unless you have specified 'set print address off'. d14779 1 a14779 1 5. GDB supports the C++ name resolution operator '::'--your d14781 1 a14781 1 Since one scope may be defined in another, you can use '::' d14783 1 a14783 1 'SCOPE1::SCOPE2::NAME'. GDB also allows resolving name scope by d14797 1 a14797 1 'off' whenever the working language changes to C or C++. This happens d14801 1 a14801 1 source files whose names end with '.c', '.C', or '.cc', etc, and when d14827 3 a14829 3 The 'set print union' and 'show print union' commands apply to the 'union' type. When set to 'on', any 'union' that is inside a 'struct' or 'class' is also printed. Otherwise, it appears as '{...}'. d14831 1 a14831 1 The '@@' operator aids in the debugging of dynamic arrays, formed with d14844 1 a14844 1 'breakpoint menus' d14850 1 a14850 1 'rbreak REGEX' d14855 3 a14857 3 'catch throw' 'catch rethrow' 'catch catch' d14861 1 a14861 1 'ptype TYPENAME' d14865 2 a14866 2 'info vtbl EXPRESSION.' The 'info vtbl' command can be used to display the virtual method d14871 1 a14871 1 'demangle NAME' d14873 1 a14873 1 the 'demangle' command. d14875 4 a14878 4 'set print demangle' 'show print demangle' 'set print asm-demangle' 'show print asm-demangle' d14883 2 a14884 2 'set print object' 'show print object' d14888 2 a14889 2 'set print vtbl' 'show print vtbl' d14891 2 a14892 2 Print Settings: Print Settings. (The 'vtbl' commands do not work on programs compiled with the HP ANSI C++ compiler ('aCC').) d14894 1 a14894 1 'set overload-resolution on' d14902 1 a14902 1 'set overload-resolution off' d14911 1 a14911 1 'show overload-resolution' d14914 1 a14914 1 'Overloaded symbol names' d14917 1 a14917 1 C++: type 'SYMBOL(TYPES)' rather than just SYMBOL. You can also d14922 1 a14922 1 'Breakpoints in template functions' d14930 1 a14930 1 The '-qualified' flag may be used to override this behavior, d14938 1 a14938 1 'Breakpoints in functions with ABI tags' d14951 1 a14951 1 when compiled for the C++11 ABI is marked with the 'cxx11' ABI tag, d14980 1 a14980 1 '_Decimal32', '_Decimal64' and '_Decimal128' types as specified by the d14988 1 a14988 1 Because of a limitation in 'libdecnumber', the library used by GDB to d14997 1 a14997 1 to inspect '_Decimal128' values stored in floating point registers. See d15017 1 a15017 1 'gccgo' or '6g' compilers. d15021 1 a15021 1 'The current Go package' d15033 1 a15033 1 When stopped inside 'main' either of these work: d15038 2 a15039 2 'Builtin Go types' The 'string' type is recognized by GDB and is printed as a string. d15041 2 a15042 2 'Builtin Go functions' The GDB expression parser recognizes the 'unsafe.Sizeof' function d15045 2 a15046 2 'Restrictions on Go expressions' All Go operators are supported except '&^'. The Go '_' "blank d15075 5 a15079 5 * 'clear' * 'break' * 'info line' * 'jump' * 'list' d15089 2 a15090 2 example, to set a breakpoint at the 'create' instance method of class 'Fruit' in the program currently being debugged, enter: d15094 1 a15094 1 To list ten program lines around the 'initialize' class method, d15107 1 a15107 1 your program's source files contain more than one 'create' method, d15109 1 a15109 1 method. Indicate your choice by number, or type '0' to exit if none d15113 1 a15113 1 'makeKeyAndOrderFront:' method of the 'NSWindow' class, enter: d15128 2 a15129 2 will tell GDB to send the 'hash' message to OBJECT and print the result. Also, an additional command has been added, 'print-object' or 'po' for d15132 1 a15132 1 a particular hook function, '_NSPrintForDebugger', defined. d15156 1 a15156 1 types of the 'cl_khr_fp16' and 'cl_khr_fp64' OpenCL extensions are also d15194 1 a15194 1 the 'set case-insensitive' command, see *note Symbols::, for the d15210 5 a15214 5 In Fortran the primitive data-types have an associated 'KIND' type parameter, written as 'TYPE*KINDPARAM', 'TYPE*KINDPARAM', or in the GDB-only dialect 'TYPE_KINDPARAM'. A concrete example would be ''Real*4'', ''Real(kind=4)'', and ''Real_4''. The kind of a type can be retrieved by using the intrinsic function 'KIND', see *note Fortran d15217 1 a15217 1 Generally, the actual implementation of the 'KIND' type parameter is d15219 1 a15219 1 accordance with its use in the GNU 'gfortran' compiler. Here, the kind d15221 2 a15222 2 'Integer*4' or 'Integer(kind=4)' would be an integer type occupying 4 bytes of memory. An exception to this rule is the 'Complex' type for d15224 2 a15225 2 size of each of the two 'Real''s it is composed of. A 'Complex*4' would thus consist of two 'Real*4's and occupy 8 bytes of memory. d15228 1 a15228 1 e.g. 'Integer' in GDB will internally be an 'Integer*4' (see the table d15231 1 a15231 1 by compiler flags such as '-fdefault-integer-8' and '-fdefault-real-8'. d15236 14 a15249 14 'Integer' 'Integer*1', 'Integer*2', 'Integer*4', 'Integer*8', and 'Integer' = 'Integer*4'. 'Logical' 'Logical*1', 'Logical*2', 'Logical*4', 'Logical*8', and 'Logical' = 'Logical*4'. 'Real' 'Real*4', 'Real*8', 'Real*16', and 'Real' = 'Real*4'. 'Complex' 'Complex*4', 'Complex*8', 'Complex*16', and 'Complex' = 'Complex*4'. d15258 1 a15258 1 '+' is defined on numbers, but not on characters or other non- d15261 1 a15261 1 '**' d15265 1 a15265 1 ':' d15269 1 a15269 1 '%' d15274 1 a15274 1 '::' d15287 1 a15287 1 these procedures take an optional 'KIND' parameter, see *note Fortran d15290 1 a15290 1 'ABS(A)' d15292 1 a15292 1 supported for 'Complex' arguments. d15294 1 a15294 1 'ALLOCATE(ARRAY)' d15297 1 a15297 1 'ASSOCIATED(POINTER [, TARGET])' d15301 1 a15301 1 'CEILING(A [, KIND])' d15304 1 a15304 1 'Integer(KIND)'. d15306 1 a15306 1 'CMPLX(X [, Y [, KIND]])' d15310 1 a15310 1 to '0.0' except if X itself is of 'Complex' type. The optional d15312 1 a15312 1 'Complex(KIND)'. d15314 1 a15314 1 'FLOOR(A [, KIND])' d15317 1 a15317 1 'Integer(KIND)'. d15319 1 a15319 1 'KIND(A)' d15323 1 a15323 1 'LBOUND(ARRAY [, DIM [, KIND]])' d15326 1 a15326 1 specifies the kind of the return type 'Integer(KIND)'. d15328 2 a15329 2 'LOC(X)' Returns the address of X as an 'Integer'. d15331 1 a15331 1 'MOD(A, P)' d15334 1 a15334 1 'MODULO(A, P)' d15337 2 a15338 2 'RANK(A)' Returns the rank of a scalar or array (scalars have rank '0'). d15340 2 a15341 2 'SHAPE(A)' Returns the shape of a scalar or array (scalars have shape '()'). d15343 1 a15343 1 'SIZE(ARRAY[, DIM [, KIND]])' d15347 1 a15347 1 'Integer(KIND)'. d15349 1 a15349 1 'UBOUND(ARRAY [, DIM [, KIND]])' d15352 1 a15352 1 specifies the kind of the return type 'Integer(KIND)'. d15363 2 a15364 2 'info common [COMMON-NAME]' This command prints the values contained in the Fortran 'COMMON' d15366 1 a15366 1 all 'COMMON' blocks visible at the current program location are d15368 2 a15369 2 'set fortran repack-array-slices [on|off]' 'show fortran repack-array-slices' d15387 1 a15387 1 The default for this setting is 'off'. d15399 1 a15399 1 The Pascal-specific command 'set print pascal_static-members' d15414 1 a15414 1 * Linespecs (*note Location Specifications::) are never relative to d15416 1 a15416 1 namespace of crates, somewhat similar to the way 'extern crate' d15420 2 a15421 2 'A', module 'B', then 'break B::f' will attempt to set a breakpoint in a function named 'f' in a crate named 'B'. d15424 1 a15424 1 items using 'self::' or 'super::'. d15426 1 a15426 1 * Because GDB implements Rust name-lookup semantics in expressions, d15428 2 a15429 2 example, if GDB is stopped at a breakpoint in the crate 'K', then 'print ::x::y' will try to find the symbol 'K::x::y'. d15432 2 a15433 2 when debugging, GDB provides the 'extern' extension to circumvent this. To use the extension, just put 'extern' before a path d15436 2 a15437 2 In the above example, if you wanted to refer to the symbol 'y' in the crate 'x', you would use 'print extern x::y'. d15439 2 a15440 2 * The Rust expression evaluator does not support "statement-like" expressions such as 'if' or 'match', or lambda expressions. d15442 1 a15442 1 * Tuple expressions are not implemented. d15444 2 a15445 2 * The Rust expression evaluator does not currently implement the 'Drop' trait. Objects that may be created by the evaluator will d15448 1 a15448 1 * GDB does not implement type inference for generics. In order to d15452 1 a15452 1 * GDB currently uses the C++ demangler for Rust. In most cases this d15455 1 a15455 1 results. This happens because Rust requires the '::' operator d15457 2 a15458 2 GDB might provide a completion like 'crate::f', where the parser would require 'crate::f::'. d15460 1 a15460 1 * As of this writing, the Rust compiler (version 1.8) has a few holes d15464 1 a15464 1 * Method calls cannot be made via traits. d15466 1 a15466 1 * Operator overloading is not implemented. d15468 1 a15468 1 * When debugging in a monomorphized function, you cannot use the d15471 1 a15471 1 * The type 'Self' is not available. d15473 1 a15473 1 * 'use' statements are not available, so some names may not be d15497 1 a15497 1 * M2 Scope:: The scope operators '::' and '.' d15507 1 a15507 1 '+' is defined on numbers, but not on structures. Operators are often d15511 1 a15511 1 * _Integral types_ consist of 'INTEGER', 'CARDINAL', and their d15514 1 a15514 1 * _Character types_ consist of 'CHAR' and its subranges. d15516 1 a15516 1 * _Floating-point types_ consist of 'REAL'. d15518 1 a15518 1 * _Pointer types_ consist of anything declared as 'POINTER TO TYPE'. d15520 1 a15520 1 * _Scalar types_ consist of all of the above. d15522 1 a15522 1 * _Set types_ consist of 'SET' and 'BITSET' types. d15524 1 a15524 1 * _Boolean types_ consist of 'BOOLEAN'. d15529 1 a15529 1 ',' d15532 2 a15533 2 ':=' Assignment. The value of VAR ':=' VALUE is VALUE. d15535 1 a15535 1 '<, >' d15539 1 a15539 1 '<=, >=' d15542 1 a15542 1 Same precedence as '<'. d15544 1 a15544 1 '=, <>, #' d15546 2 a15547 2 types. Same precedence as '<'. In GDB scripts, only '<>' is available for inequality, since '#' conflicts with the script d15550 1 a15550 1 'IN' d15552 1 a15552 1 members. Same precedence as '<'. d15554 1 a15554 1 'OR' d15557 1 a15557 1 'AND, &' d15560 1 a15560 1 '@@' d15564 1 a15564 1 '+, -' d15568 1 a15568 1 '*' d15572 1 a15572 1 '/' d15574 1 a15574 1 set types. Same precedence as '*'. d15576 1 a15576 1 'DIV, MOD' d15578 1 a15578 1 precedence as '*'. d15580 2 a15581 2 '-' Negative. Defined on 'INTEGER' and 'REAL' data. d15583 1 a15583 1 '^' d15586 1 a15586 1 'NOT' d15588 1 a15588 1 '^'. d15590 3 a15592 3 '.' 'RECORD' field selector. Defined on 'RECORD' data. Same precedence as '^'. d15594 2 a15595 2 '[]' Array indexing. Defined on 'ARRAY' data. Same precedence as '^'. d15597 3 a15599 3 '()' Procedure argument list. Defined on 'PROCEDURE' objects. Same precedence as '^'. d15601 1 a15601 1 '::, .' d15605 2 a15606 2 supported, so GDB treats the use of the operator 'IN', or the use of operators '+', '-', '*', '/', '=', , '<>', '#', '<=', and '>=' d15619 1 a15619 1 represents an 'ARRAY' variable. d15622 1 a15622 1 represents a 'CHAR' constant or variable. d15630 1 a15630 1 'SET OF MTYPE' (where MTYPE is the type of M). d15652 1 a15652 1 'ABS(N)' d15655 1 a15655 1 'CAP(C)' d15659 1 a15659 1 'CHR(I)' d15662 1 a15662 1 'DEC(V)' d15666 1 a15666 1 'DEC(V,I)' d15670 1 a15670 1 'EXCL(M,S)' d15673 1 a15673 1 'FLOAT(I)' d15676 1 a15676 1 'HIGH(A)' d15679 1 a15679 1 'INC(V)' d15683 1 a15683 1 'INC(V,I)' d15687 1 a15687 1 'INCL(M,S)' d15691 1 a15691 1 'MAX(T)' d15694 1 a15694 1 'MIN(T)' d15697 1 a15697 1 'ODD(I)' d15700 1 a15700 1 'ORD(X)' d15707 1 a15707 1 'SIZE(X)' d15711 1 a15711 1 'TRUNC(R)' d15714 1 a15714 1 'TSIZE(X)' d15718 1 a15718 1 'VAL(T,I)' d15722 1 a15722 1 treats the use of procedures 'INCL' and 'EXCL' as an error. d15733 1 a15733 1 * Integer constants are simply a sequence of digits. When used in an d15736 1 a15736 1 a trailing 'H', and octal integers by a trailing 'B'. d15738 1 a15738 1 * Floating point constants appear as a sequence of digits, followed d15740 2 a15741 2 exponent can then be specified, in the form 'E[+|-]NNN', where '[+|-]NNN' is the desired exponent. All of the digits of the d15744 2 a15745 2 * Character constants consist of a single character enclosed by a pair of like quotes, either single (''') or double ('"'). They may d15747 1 a15747 1 usually) followed by a 'C'. d15749 2 a15750 2 * String constants consist of a sequence of characters enclosed by a pair of like quotes, either single (''') or double ('"'). Escape d15755 1 a15755 1 * Enumerated constants consist of an enumerated identifier. d15757 1 a15757 1 * Boolean constants consist of the identifiers 'TRUE' and 'FALSE'. d15759 1 a15759 1 * Pointer constants consist of integral values only. d15761 1 a15761 1 * Set constants are not yet supported. d15781 2 a15782 2 and you can request GDB to interrogate the type and value of 'r' and 's'. d15793 1 a15793 1 Likewise if your source code declares 's' as: d15798 1 a15798 1 then you may query the type of 's' by: d15818 1 a15818 1 arrays have a lower bound of zero and not '-10' as in the example above. d15839 1 a15839 1 Observe that the contents are written in the same way as their 'C' d15861 1 a15861 1 and you can request that GDB describes the type of 's'. d15881 1 a15881 1 and you can ask GDB to describe the type of 's' as shown below. d15897 1 a15897 1 default to 'on' whenever the working language changes to Modula-2. This d15901 1 a15901 1 code compiled from a file whose name ends with '.mod' sets the working d15914 1 a15914 1 * Unlike in standard Modula-2, pointer constants can be formed by d15921 1 a15921 1 * C escape sequences can be used in strings and characters to d15924 1 a15924 1 are printed using the 'CHR(NNN)' format. d15926 1 a15926 1 * The assignment operator (':=') returns the value of its right-hand d15929 1 a15929 1 * All built-in procedures both modify _and_ return their argument. d15942 2 a15943 2 * They are of types that have been declared equivalent via a 'TYPE T1 = T2' statement d15945 1 a15945 1 * They have been declared on the same line. (Note: This is true of d15958 1 a15958 1 15.4.9.8 The Scope Operators '::' and '.' d15962 1 a15962 1 ('.') and the GDB scope operator ('::'). The two have similar syntax: d15972 1 a15972 1 Using the '::' operator makes GDB search the scope specified by SCOPE d15976 1 a15976 1 Using the '.' operator makes GDB search the current scope for the d15989 3 a15991 3 Five subcommands of 'set print' and 'show print' apply specifically to C and C++: 'vtbl', 'demangle', 'asm-demangle', 'object', and 'union'. The first four apply to C++, and the last to the C 'union' type, which has d15994 1 a15994 1 The '@@' operator (*note Expressions: Expressions.), while available d15996 1 a15996 1 the debugging of "dynamic arrays", which cannot be created in Modula-2 d15998 1 a15998 1 by an integral constant, the construct '{TYPE}ADREXP' is still useful. d16000 2 a16001 2 In GDB scripts, the Modula-2 inequality operator '#' is interpreted as the beginning of a comment. Use '<>' instead. d16042 1 a16042 1 * That GDB should provide basic literals and access to operations for d16048 1 a16048 1 * That type safety and strict adherence to Ada language restrictions d16051 1 a16051 1 * That brevity is important to the GDB user. d16064 1 a16064 1 mostly for documenting command files. The standard GDB comment ('#') d16076 1 a16076 1 * Only a subset of the attributes are supported: d16078 1 a16078 1 - 'First, 'Last, and 'Length on array objects (not on types and d16081 1 a16081 1 - 'Min and 'Max. d16083 1 a16083 1 - 'Pos and 'Val. d16085 1 a16085 1 - 'Tag. d16087 2 a16088 2 - 'Range on array objects (not subtypes), but only as the right operand of the membership ('in') operator. d16090 1 a16090 1 - 'Access, 'Unchecked_Access, and 'Unrestricted_Access (a GNAT d16093 1 a16093 1 - 'Address. d16095 1 a16095 1 * The names in 'Characters.Latin_1' are not available. d16097 1 a16097 1 * Equality tests ('=' and '/=') on arrays test for bitwise equality d16106 2 a16107 2 * The other component-by-component array operations ('and', 'or', 'xor', 'not', and relational tests other than equality) are not d16110 1 a16110 1 * There is limited support for array and record aggregates. They are d16126 1 a16126 1 'A_Rec' declared to have a type such as: d16133 1 a16133 1 you can assign a value with a different size of 'Vals' with two d16141 2 a16142 2 components of an array or record aggregate (such as the 'Len' component in the assignment to 'A_Rec' above); they will retain d16148 1 a16148 1 * Calls to dispatching subprograms are not implemented. d16150 1 a16150 1 * The overloading algorithm is much more limited (i.e., less d16157 1 a16157 1 * The 'new' operator is not implemented. d16159 1 a16159 1 * Entry calls are not implemented. d16161 1 a16161 1 * Aside from printing, arithmetic operations on the native VAX d16164 1 a16164 1 * It is not possible to slice a packed array. d16166 2 a16167 2 * The names 'True' and 'False', when not part of a qualified name, are interpreted as if implicitly prefixed by 'Standard', regardless d16172 1 a16172 1 * Based real literals are not implemented. d16183 1 a16183 1 * If the expression E is a variable residing in memory (typically a d16185 1 a16185 1 'E@@N' displays the values of E and the N-1 adjacent variables d16192 1 a16192 1 * 'B::VAR' means "the variable named VAR that appears in function or d16196 1 a16196 1 * The expression '{TYPE} ADDR' means "the variable of type TYPE that d16199 1 a16199 1 * A name starting with '$' is a convenience variable (*note d16205 1 a16205 1 * The assignment statement is allowed as an expression, returning its d16211 1 a16211 1 * The semicolon is allowed as an "operator," returning as its value d16218 1 a16218 1 * An extension to based literals can be used to specify the exact d16220 4 a16223 4 use from zero to two 'l' characters, followed by an 'f'. The number of 'l' characters controls the width of the resulting real constant: zero means 'Float' is used, one means 'Long_Float', and two means 'Long_Long_Float'. d16228 1 a16228 1 * Rather than use catenation and symbolic character names to d16231 1 a16231 1 sequence of characters of the form '["XX"]' within a string or d16233 1 a16233 1 encoding is XX in hexadecimal. The sequence of characters '["""]' d16236 1 a16236 1 contains an ASCII newline character ('Ada.Characters.Latin_1.LF') d16239 1 a16239 1 * The subtype used as a prefix for the attributes 'Pos, 'Min, and d16245 1 a16245 1 * When printing arrays, GDB uses positional notation when the array d16253 1 a16253 1 '=>' clause. d16255 1 a16255 1 * You may abbreviate attributes in expressions with any unique, d16260 1 a16260 1 * Since Ada is case-insensitive, the debugger normally maps d16268 1 a16268 1 * Printing an object of class-wide type or dereferencing an d16285 1 a16285 1 'call' command, and functions to procedures elsewhere. d16299 1 a16299 1 evaluation (type '0' and press ) or to continue evaluation with a d16305 1 a16305 1 'set ada print-signatures' d16307 1 a16307 1 overloads selection menus. It is 'on' by default. *Note d16310 1 a16310 1 'show ada print-signatures' d16324 2 a16325 2 'adainit'. To run your program up to the beginning of elaboration, simply use the following two commands: 'tbreak adainit' and 'run'. d16335 3 a16337 3 'info exceptions' 'info exceptions REGEXP' The 'info exceptions' command allows you to list all Ada exceptions d16370 1 a16370 1 'info tasks' d16400 1 a16400 1 'Unactivated' d16404 1 a16404 1 'Runnable' d16409 1 a16409 1 'Terminated' d16414 1 a16414 1 'Child Activation Wait' d16418 1 a16418 1 'Accept or Select Term' d16422 1 a16422 1 'Waiting on entry call' d16425 1 a16425 1 'Async Select Wait' d16429 1 a16429 1 'Delay Sleep' d16433 1 a16433 1 'Child Termination Wait' d16439 1 a16439 1 'Wait Child in Term Alt' d16443 1 a16443 1 'Asynchronous Hold' d16445 1 a16445 1 'Ada.Asynchronous_Task_Control.Hold_Task'. d16447 1 a16447 1 'Activating' d16450 1 a16450 1 'Selective Wait' d16453 1 a16453 1 'Accepting RV with TASKNO' d16456 1 a16456 1 'Waiting on RV with TASKNO' d16463 1 a16463 1 'info task TASKNO' d16479 1 a16479 1 'task' d16489 2 a16490 2 'task TASKNO' This command is like the 'thread THREAD-ID' command (*note d16508 3 a16510 3 'task apply [TASK-ID-LIST | all] [FLAG]... COMMAND' The 'task apply' command is the Ada tasking analogue of 'thread apply' (*note Threads::). It allows you to apply the named COMMAND d16512 1 a16512 1 using a list of task IDs, or specify 'all' to apply to all tasks. d16516 3 a16518 3 with a '-' directly followed by one letter in 'qcs'. If several flags are provided, they must be given individually, such as '-c -q'. d16522 1 a16522 1 COMMAND will abort 'task apply'. The following flags can be used d16525 3 a16527 3 '-c' The flag '-c', which stands for 'continue', causes any errors in COMMAND to be displayed, and the execution of 'task apply' d16529 2 a16530 2 '-s' The flag '-s', which stands for 'silent', causes any errors or d16534 2 a16535 2 '-q' The flag '-q' ('quiet') disables printing the task d16538 1 a16538 1 Flags '-c' and '-s' cannot be used together. d16540 3 a16542 3 'break LOCSPEC task TASKNO' 'break LOCSPEC task TASKNO if ...' These commands are like the 'break ... thread ...' command (*note d16546 1 a16546 1 Use the qualifier 'task TASKNO' with a breakpoint command to d16550 1 a16550 1 column of the 'info tasks' display. d16552 1 a16552 1 If you do not specify 'task TASKNO' when you set a breakpoint, the d16555 3 a16557 3 You can use the 'task' qualifier on conditional breakpoints as well; in this case, place 'task TASKNO' before the breakpoint condition (before the 'if'). d16597 1 a16597 1 privileges, using the command '"set write on"' (*note Patching::). d16607 1 a16607 1 The "Ravenscar Profile" is a subset of the Ada tasking features, d16611 1 a16611 1 'set ravenscar task-switching on' d16615 1 a16615 1 'set ravenscar task-switching off' d16623 1 a16623 1 'show ravenscar task-switching' d16634 1 a16634 1 the output of 'info threads': d16647 2 a16648 2 sequence. If you need to debug this code, you should use 'set ravenscar task-switching off'. d16660 1 a16660 1 'set ada source-charset CHARSET' d16665 1 a16665 1 'ISO-8859-1', because that is also GNAT's default. d16667 1 a16667 1 'show ada source-charset' d16681 1 a16681 1 * Static constants that the compiler chooses not to materialize as d16684 1 a16684 1 * Named parameter associations in function argument lists are ignored d16687 1 a16687 1 * Many useful library packages are currently invisible to the d16690 1 a16690 1 * Fixed-point arithmetic, conversions, input, and output is carried d16694 1 a16694 1 * The GNAT compiler never generates the prefix 'Standard' for any of d16701 1 a16701 1 'Standard', GNAT's lack of qualification here can cause confusion. d16703 1 a16703 1 qualifying the problematic names with package 'Standard' d16712 1 a16712 1 'set ada trust-PAD-over-XVS on' d16714 2 a16715 2 the value of Ada entities, particularly when 'PAD' and 'PAD___XVS' types are involved (see 'ada/exp_dbug.ads' in the GCC sources for a d16719 1 a16719 1 'set ada trust-PAD-over-XVS off' d16722 4 a16725 4 'ada trust-PAD-over-XVS' to 'off' activates a work-around which may fix the issue. It is always safe to set 'ada trust-PAD-over-XVS' to 'off', but this incurs a slight performance penalty, so it is recommended to leave this setting to 'on' unless necessary. d16728 2 a16729 2 number of conventions known as the 'GNAT Encoding', all documented in 'gcc/ada/exp_dbug.ads' in the GCC sources. This encoding describes how d16731 1 a16731 1 particular, this convention makes use of "descriptive types", which are d16743 1 a16743 1 'maintenance ada set ignore-descriptive-types [on|off]' d16745 1 a16745 1 default is not to ignore descriptives types ('off'). d16747 1 a16747 1 'maintenance ada show ignore-descriptive-types' d16757 1 a16757 1 provides a pseudo-language, called 'minimal'. It does not represent a d16763 1 a16763 1 If the language is set to 'auto', GDB will automatically select this d16785 2 a16786 2 typical file name, like 'foo.c', as the three words 'foo' '.' 'c'. To allow GDB to recognize 'foo.c' as a single symbol, enclose it in single d16791 1 a16791 1 looks up the value of 'x' in the scope of the file 'foo.c'. d16793 3 a16795 3 'set case-sensitive on' 'set case-sensitive off' 'set case-sensitive auto' d16798 4 a16801 4 Occasionally, you may wish to control that. The command 'set case-sensitive' lets you do that by specifying 'on' for case-sensitive matches or 'off' for case-insensitive ones. If you specify 'auto', case sensitivity is reset to the default suitable d16806 1 a16806 1 'show case-sensitive' d16810 3 a16812 3 'set print type methods' 'set print type methods on' 'set print type methods off' d16815 3 a16817 3 appropriate flag to 'ptype', or using 'set print type methods'. Specifying 'on' will cause GDB to display the methods; this is the default. Specifying 'off' will cause GDB to omit the methods. d16819 1 a16819 1 'show print type methods' d16823 2 a16824 2 'set print type nested-type-limit LIMIT' 'set print type nested-type-limit unlimited' d16826 1 a16826 1 show. A LIMIT of 'unlimited' or '-1' will show all nested d16830 1 a16830 1 'show print type nested-type-limit' d16834 3 a16836 3 'set print type typedefs' 'set print type typedefs on' 'set print type typedefs off' d16840 3 a16842 3 appropriate flag to 'ptype', or using 'set print type typedefs'. Specifying 'on' will cause GDB to display the typedef definitions; this is the default. Specifying 'off' will cause GDB to omit the d16847 1 a16847 1 'show print type typedefs' d16851 3 a16853 3 'set print type hex' 'set print type hex on' 'set print type hex off' d16857 2 a16858 2 the other either by passing the appropriate flag to 'ptype', or by using the 'set print type hex' command. d16860 1 a16860 1 'show print type hex' d16864 1 a16864 1 'info address SYMBOL' d16870 1 a16870 1 Note the contrast with 'print &SYMBOL', which does not work at all d16874 1 a16874 1 'info symbol ADDR' d16882 1 a16882 1 This is the opposite of the 'info address' command. You can use it d16893 1 a16893 1 'demangle [-l LANGUAGE] [--] NAME' d16898 1 a16898 1 The '--' option specifies the end of options, and is useful when d16901 1 a16901 1 The parameter 'demangle-style' specifies how to interpret the kind d16904 1 a16904 1 'whatis[/FLAGS] [ARG]' d16906 1 a16906 1 name of a data type. With no argument, print the data type of '$', d16913 1 a16913 1 If ARG is a variable or an expression, 'whatis' prints its literal d16915 10 a16924 10 using a 'typedef', 'whatis' will _not_ print the data type underlying the 'typedef'. If the type of the variable or the expression is a compound data type, such as 'struct' or 'class', 'whatis' never prints their fields or methods. It just prints the 'struct'/'class' name (a.k.a. its "tag"). If you want to see the members of such a compound data type, use 'ptype'. If ARG is a type name that was defined using 'typedef', 'whatis' "unrolls" only one level of that 'typedef'. Unrolling means that 'whatis' will show the underlying type used in the 'typedef' d16926 1 a16926 1 'typedef', 'whatis' will not unroll it. d16928 3 a16930 3 For C code, the type names may also have the form 'class CLASS-NAME', 'struct STRUCT-TAG', 'union UNION-TAG' or 'enum ENUM-TAG'. d16935 1 a16935 1 'r' d16938 1 a16938 1 class' members. The '/r' flag disables this. d16940 1 a16940 1 'm' d16943 1 a16943 1 'M' d16945 2 a16946 2 the flag exists in case you change the default with 'set print type methods'. d16948 1 a16948 1 't' d16954 1 a16954 1 'T' d16956 2 a16957 2 the flag exists in case you change the default with 'set print type typedefs'. d16959 1 a16959 1 'o' d16961 1 a16961 1 what the 'pahole' tool does. This option implies the '/tm' d16964 1 a16964 1 'x' d16968 1 a16968 1 'd' d17006 1 a17006 1 Issuing a 'ptype /o struct tuv' command would print: d17019 1 a17019 1 can find two parts separated by the '|' character: the d17058 1 a17058 1 In this case, since 'struct tuv' and 'struct xyz' occupy the d17085 2 a17086 2 'ptype[/FLAGS] [ARG]' 'ptype' accepts the same arguments as 'whatis', but prints a d17090 1 a17090 1 Contrary to 'whatis', 'ptype' always unrolls any 'typedef's in its d17092 1 a17092 1 expression, or a data type. This means that 'ptype' of a variable d17094 4 a17097 4 the source code--use 'whatis' for that. 'typedef's at the pointer or reference targets are also unrolled. Only 'typedef's of fields, methods and inner 'class typedef's of 'struct's, 'class'es and 'union's are not unrolled even with 'ptype'. d17130 2 a17131 2 As with 'whatis', using 'ptype' without an argument refers to the type of '$', the last value in the value history. d17136 1 a17136 1 declaration of the data type, it will say ''. For d17142 1 a17142 1 but no definition for 'struct foo' itself, GDB will say: d17165 1 a17165 1 'info types [-q] [REGEXP]' d17169 4 a17172 4 it were a complete line; thus, 'i type value' gives information on all types in your program whose names include the string 'value', but 'i type ^value$' gives information only on types whose complete name is 'value'. d17175 2 a17176 2 print the type description according to the 'set language' value: using 'set language auto' (see *note Set Language Automatically: d17181 2 a17182 2 This command differs from 'ptype' in two ways: first, like 'whatis', it does not print a detailed description; second, it d17185 3 a17187 3 The output from 'into types' is proceeded with a header line describing what types are being listed. The optional flag '-q', which stands for 'quiet', disables printing this header d17190 1 a17190 1 'info type-printers' d17192 1 a17192 1 "type printers" available. When using 'ptype' or 'whatis', these d17196 1 a17196 1 'info type-printers' displays all the available type printers. d17198 2 a17199 2 'enable type-printer NAME...' 'disable type-printer NAME...' d17202 1 a17202 1 'info scope LOCSPEC' d17219 1 a17219 1 collect during a "trace experiment", see *note collect: Tracepoint d17222 1 a17222 1 'info source' d17225 5 a17229 5 * the name of the source file, and the directory containing it, * the directory it was compiled in, * its length, in lines, * which programming language it is written in, * if the debug information provides it, the program that d17232 1 a17232 1 * whether the executable includes debugging information for that d17235 1 a17235 1 * whether the debugging information includes information about d17238 1 a17238 1 'info sources [-dirname | -basename] [--] [REGEXP]' d17240 1 a17240 1 With no options 'info sources' prints the names of all source files d17253 1 a17253 1 case-insensitive filesystem (e.g., MS-Windows). '--' can be used d17255 1 a17255 1 option (e.g. if REGEXP starts with '-'). d17258 2 a17259 2 If '-dirname', only files having a dirname matching REGEXP are shown. If '-basename', only files having a basename matching d17267 1 a17267 1 'info functions [-q] [-n]' d17269 1 a17269 1 to 'info types', this command groups its output by source files and d17273 2 a17274 2 print the function name and type according to the 'set language' value: using 'set language auto' (see *note Set Language d17279 1 a17279 1 The '-n' flag excludes "non-debugging symbols" from the results. A d17284 1 a17284 1 The optional flag '-q', which stands for 'quiet', disables printing d17288 2 a17289 2 'info functions [-q] [-n] [-t TYPE_REGEXP] [REGEXP]' Like 'info functions', but only print the names and data types of d17293 3 a17295 3 the regular expression REGEXP. Thus, 'info fun step' finds all functions whose names include 'step'; 'info fun ^step' finds those whose names start with 'step'. If a function name contains d17297 1 a17297 1 'operator*()'), they may be quoted with a backslash. d17300 1 a17300 1 as printed by the 'whatis' command, match the regular expression d17303 5 a17307 5 the meaning of special characters or quotes. Thus, 'info fun -t '^int ('' finds the functions that return an integer; 'info fun -t '(.*int.*'' finds the functions that have an argument type containing int; 'info fun -t '^int (' ^step' finds the functions whose names start with 'step' and that return int. d17312 1 a17312 1 'info variables [-q] [-n]' d17319 2 a17320 2 print the variable name and type according to the 'set language' value: using 'set language auto' (see *note Set Language d17325 1 a17325 1 The '-n' flag excludes non-debugging symbols from the results. d17327 1 a17327 1 The optional flag '-q', which stands for 'quiet', disables printing d17331 2 a17332 2 'info variables [-q] [-n] [-t TYPE_REGEXP] [REGEXP]' Like 'info variables', but only print the variables selected with d17339 1 a17339 1 as printed by the 'whatis' command, match the regular expression d17347 1 a17347 1 'info modules [-q] [REGEXP]' d17351 1 a17351 1 The optional flag '-q', which stands for 'quiet', disables printing d17355 2 a17356 2 'info module functions [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]' 'info module variables [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]' d17366 1 a17366 1 The optional flag '-q', which stands for 'quiet', disables printing d17370 1 a17370 1 'info main' d17375 2 a17376 2 'info classes' 'info classes REGEXP' d17381 2 a17382 2 'info selectors' 'info selectors REGEXP' d17387 1 a17387 1 'set opaque-type-resolution on' d17389 3 a17391 3 declared as a pointer to a 'struct', 'class', or 'union'--for example, 'struct MyType *'--that is used in one source file although the full declaration of 'struct MyType' is in another d17397 1 a17397 1 'set opaque-type-resolution off' d17402 1 a17402 1 'show opaque-type-resolution' d17405 5 a17409 5 'set print symbol-loading' 'set print symbol-loading full' 'set print symbol-loading brief' 'set print symbol-loading off' The 'set print symbol-loading' command allows you to control the d17414 1 a17414 1 messages can be annoying. When set to 'brief' a message is printed d17417 1 a17417 1 number of shared libraries. When set to 'off' no messages are d17420 1 a17420 1 'show print symbol-loading' d17424 5 a17428 5 'maint print symbols [-pc ADDRESS] [FILENAME]' 'maint print symbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]' 'maint print psymbols [-objfile OBJFILE] [-pc ADDRESS] [--] [FILENAME]' 'maint print psymbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]' 'maint print msymbols [-objfile OBJFILE] [--] [FILENAME]' d17430 2 a17431 2 terminal if FILENAME is unspecified. If '-objfile OBJFILE' is specified, only dump symbols for that objfile. If '-pc ADDRESS' is d17433 2 a17434 2 address. Note that ADDRESS may be a symbol like 'main'. If '-source SOURCE' is specified, only dump symbols for that source d17438 4 a17441 4 These commands do not modify internal GDB state, therefore 'maint print symbols' will only print symbols for already expanded symbol tables. You can use the command 'info sources' to find out which files these are. If you use 'maint print psymbols' instead, the d17444 1 a17444 1 but not yet read completely. Finally, 'maint print msymbols' just d17448 1 a17448 1 reads symbols (in the description of 'symbol-file'). d17450 2 a17451 2 'maint info symtabs [ REGEXP ]' 'maint info psymtabs [ REGEXP ]' d17453 1 a17453 1 List the 'struct symtab' or 'struct partial_symtab' structures d17475 1 a17475 1 contains the string 'dwarf2read', belonging to the 'gdb' d17497 1 a17497 1 'maint info line-table [ REGEXP ]' d17499 1 a17499 1 List the 'struct linetable' from all 'struct symtab' instances d17501 1 a17501 1 'struct linetable' from all 'struct symtab'. For example: d17521 1 a17521 1 The 'IS-STMT' column indicates if the address is a recommended d17523 1 a17523 1 'PROLOGUE-END' column indicates that a given address is an adequate d17525 1 a17525 1 function prologue. The 'EPILOGUE-BEGIN' column indicates that a d17529 2 a17530 2 'set always-read-ctf [on|off]' 'show always-read-ctf' d17536 1 a17536 1 'maint set symbol-cache-size SIZE' d17541 1 a17541 1 'maint show symbol-cache-size' d17544 1 a17544 1 'maint print symbol-cache' d17548 1 a17548 1 'maint print symbol-cache-statistics' d17552 2 a17553 2 'maint flush symbol-cache' 'maint flush-symbol-cache' d17556 7 a17562 7 useful when collecting performance data. The command 'maint flush-symbol-cache' is deprecated in favor of 'maint flush symbol-cache'.. 'maint set ignore-prologue-end-flag [on|off]' Enable or disable the use of the 'PROLOGUE-END' flag from the line-table. When 'off' (the default), GDB uses the 'PROLOGUE-END' d17564 1 a17564 1 When 'on', GDB ignores the flag and relies on prologue analyzers to d17567 2 a17568 2 'maint show ignore-prologue-end-flag' Show whether GDB will ignore the 'PROLOGUE-END' flag. d17607 1 a17607 1 stores the value 4 into the variable 'x', and then prints the value of d17613 2 a17614 2 the 'set' command instead of the 'print' command. 'set' is really the same as 'print' except that the expression's value is not printed and is d17618 6 a17623 6 If the beginning of the argument string of the 'set' command appears identical to a 'set' subcommand, use the 'set variable' command instead of just 'set'. This command is identical to 'set' except for its lack of subcommands. For example, if your program has a variable 'width', you get an error if you try to set a new value with just 'set width=13', because GDB has the command 'set width': d17632 2 a17633 2 The invalid expression, of course, is '=47'. In order to actually set the program's variable 'width', use d17637 6 a17642 6 Because the 'set' command has many subcommands that can conflict with the names of program variables, it is a good idea to use the 'set variable' command instead of just 'set'. For example, if your program has a variable 'g', you run into problems if you try to set a new value with just 'set g=4', because GDB has the command 'set gnutarget', abbreviated 'set g': d17660 2 a17661 2 The program variable 'g' did not change, and you silently set the 'gnutarget' to an invalid value. In order to set the variable 'g', use d17670 1 a17670 1 To store values into arbitrary places in memory, use the '{...}' d17672 2 a17673 2 (*note Expressions: Expressions.). For example, '{int}0x83040' refers to memory location '0x83040' as an integer (which implies a certain size d17687 1 a17687 1 it stopped, with the 'continue' command. You can instead continue at an d17690 2 a17691 2 'jump LOCSPEC' 'j LOCSPEC' d17699 2 a17700 2 is a breakpoint there. It is common practice to use the 'tbreak' command in conjunction with 'jump'. *Note Setting Breakpoints: Set d17703 1 a17703 1 The 'jump' command does not change the current stack frame, or the d17709 1 a17709 1 'jump' command requests confirmation if the jump address is not in d17714 2 a17715 2 On many systems, you can get much the same effect as the 'jump' command by storing a new value into the register '$pc'. The difference d17721 2 a17722 2 makes the next 'continue' command or stepping command execute at address '0x485', rather than at the address where your program stopped. *Note d17725 2 a17726 2 However, writing directly to '$pc' will only change the value of the program-counter register, while using 'jump' will ensure that any d17728 3 a17730 3 'jump' will update both '$pc' and '$npc' registers prior to resuming execution. When using the approach of writing directly to '$pc' it is your job to also update the '$npc' register. d17732 1 a17732 1 The most common occasion to use the 'jump' command is to back d17742 1 a17742 1 'signal SIGNAL' d17745 2 a17746 2 number of a signal. For example, on many systems 'signal 2' and 'signal SIGINT' are both ways of sending an interrupt signal. d17751 1 a17751 1 'continue' command; 'signal 0' causes it to resume without a d17759 1 a17759 1 before issuing the 'signal 0' command. If you issue the 'signal 0' d17763 2 a17764 2 Invoking the 'signal' command is not the same as invoking the 'kill' utility from the shell. Sending a signal with 'kill' causes d17766 1 a17766 1 handling tables (*note Signals::). The 'signal' command passes the d17769 1 a17769 1 'signal' does not repeat when you press a second time after d17772 1 a17772 1 'queue-signal SIGNAL' d17775 2 a17776 2 number of a signal. For example, on many systems 'signal 2' and 'signal SIGINT' are both ways of sending an interrupt signal. The d17779 1 a17779 1 handling of signals from GDB with the 'handle' command (*note d17786 1 a17786 1 resumed with the 'continue' command. d17788 2 a17789 2 This command differs from the 'signal' command in that the signal is just queued, execution is not resumed. And 'queue-signal' d17791 1 a17791 1 to 'nopass' (*note Signals::). d17802 3 a17804 3 'return' 'return EXPRESSION' You can cancel execution of a function call with the 'return' d17808 1 a17808 1 When you use 'return', GDB discards the selected stack frame (and all d17811 1 a17811 1 that value as the argument to 'return'. d17819 1 a17819 1 The 'return' command does not resume execution; it leaves the program d17821 1 a17821 1 In contrast, the 'finish' command (*note Continuing and Stepping: d17830 2 a17831 2 point values in CPU registers. Larger integer widths (such as 'long long int') also have specific placement rules. GDB already knows the OS d17837 4 a17840 4 debug info is available. For example, if you type 'return -1', and the function in the current stack frame is declared to return a 'long long int', GDB transparently converts the implicit 'int' value of -1 into a 'long long int': d17854 2 a17855 2 caller code expects. For example, typing 'return -1' with its implicit type 'int' would set only a part of a 'long long int' result for a debug d17874 1 a17874 1 'print EXPR' d17879 2 a17880 2 'call EXPR' Evaluate the expression EXPR without displaying 'void' returned d17883 1 a17883 1 You can use this variant of the 'print' command if you want to d17885 2 a17886 2 (a.k.a. "a void function"), but without cluttering the output with 'void' returned values that GDB will otherwise print. If the d17889 1 a17889 1 It is possible for the function you call via the 'print' or 'call' d17892 1 a17892 1 controlled by the 'set unwind-on-signal' command. d17895 1 a17895 1 call via the 'print' or 'call' command to generate an exception that is d17901 1 a17901 1 controlled by the 'set unwind-on-terminating-exception' command. d17903 1 a17903 1 'set unwind-on-signal' d17910 1 a17910 1 The command 'set unwindonsignal' is an alias for this command, and d17913 1 a17913 1 'show unwind-on-signal' d17917 1 a17917 1 The command 'show unwindonsignal' is an alias for this command, and d17920 1 a17920 1 'set unwind-on-terminating-exception' d17928 1 a17928 1 'show unwind-on-terminating-exception' d17932 1 a17932 1 'set unwind-on-timeout' d17934 2 a17935 2 If set to 'off' (the default), GDB stops in the frame where the timeout occurred. If set to 'on', GDB unwinds the stack it created d17939 1 a17939 1 'show unwind-on-timeout' d17943 1 a17943 1 'set may-call-functions' d17946 1 a17946 1 with expressions in the 'print' command. It defaults to 'on'. d17957 1 a17957 1 'show may-call-functions' d17963 1 a17963 1 call by typing the interrupt character (often 'Ctrl-c'). d17967 2 a17968 2 due to 'set unwind-on-terminating-exception on', 'set unwind-on-timeout on', or 'set unwind-on-signal on' (*note stack unwind settings::), then d17970 1 a17970 1 function, will be visible in the backtrace, for example frame '#3' in d17985 1 a17985 1 to resume the inferior (using commands like 'continue', 'step', etc). d17996 1 a17996 1 this behaviour can be adjusted with 'set unwind-on-timeout' (*note set d18002 2 a18003 2 'unlimited', meaning GDB will wait indefinitely for function call to complete, unless interrupted by the user using 'Ctrl-C'. d18005 1 a18005 1 'set direct-call-timeout SECONDS' d18008 2 a18009 2 special value 'unlimited', which indicates no timeout should be used. The default for this setting is 'unlimited'. d18012 1 a18012 1 the command prompt, for example with a 'call' or 'print' command. d18016 1 a18016 1 setting is treated as 'unlimited'. d18018 1 a18018 1 'show direct-call-timeout' d18020 1 a18020 1 'call' or 'print' command. d18027 1 a18027 1 'set indirect-call-timeout SECONDS' d18030 1 a18030 1 integer greater than zero, or the special value 'unlimited', which d18032 1 a18032 1 is '30' seconds. d18036 1 a18036 1 setting is treated as 'unlimited'. d18042 1 a18042 1 'show indirect-call-timeout' d18111 1 a18111 1 explicitly with the 'set write' command. For example, you might want to d18114 4 a18117 4 'set write on' 'set write off' If you specify 'set write on', GDB opens executable and core files for both reading and writing; if you specify 'set write off' (the d18121 1 a18121 1 the 'exec-file' or 'core-file' command) after changing 'set write', d18124 1 a18124 1 'show write' d18135 1 a18135 1 running under GDB. GCC 5.0 or higher built with 'libcc1.so' must be d18139 2 a18140 2 'compile code SOURCE-CODE' 'compile code -raw -- SOURCE-CODE' d18159 1 a18159 1 they may conflict. The '--' delimiter can be used to separate d18165 1 a18165 1 To enter this mode, invoke the 'compile code' command without any d18168 1 a18168 1 required. When you have completed typing, enter 'end' on its own d18176 1 a18176 1 Specifying '-raw', prohibits GDB from wrapping the provided d18179 3 a18181 3 '_gdb_expr_'. The '-raw' code cannot access variables of the inferior. Using '-raw' option may be needed for example when SOURCE-CODE requires '#include' lines which may conflict with d18184 3 a18186 3 'compile file FILENAME' 'compile file -raw FILENAME' Like 'compile code', but take the source code from FILENAME. d18190 2 a18191 2 'compile print [[OPTIONS] --] EXPR' 'compile print [[OPTIONS] --] /F EXPR' d18195 1 a18195 1 can choose a different format by specifying '/F', where F is a d18197 2 a18198 2 Formats. The 'compile print' command accepts the same options as the 'print' command; see *note print options::. d18200 2 a18201 2 'compile print [[OPTIONS] --]' 'compile print [[OPTIONS] --] /F' d18204 1 a18204 1 'compile print' command without any text following the command. d18209 1 a18209 1 'set debug compile' d18213 1 a18213 1 'show debug compile' d18217 1 a18217 1 'set debug compile-cplus-types' d18221 1 a18221 1 'show debug compile-cplus-types' d18225 1 a18225 1 17.7.1 Compilation options for the 'compile' command d18234 1 a18234 1 target architecture and OS options ('gdbarch') d18236 2 a18237 2 system, usually they specify at least 32-bit ('-m32') or 64-bit ('-m64') compilation option. d18241 4 a18244 4 into 'DW_AT_producer' part of DWARF debugging information according to the GCC option '-grecord-gcc-switches'. One has to explicitly specify '-g' during inferior compilation otherwise GCC produces no DWARF. This feature is only relevant for platforms where '-g' d18246 1 a18246 1 by using '-gdwarf-4'. d18248 1 a18248 1 compilation options set by 'set compile-args' d18252 1 a18252 1 'set compile-args' d18254 1 a18254 1 the 'compile' commands. These options override any conflicting d18258 1 a18258 1 'show compile-args' d18263 1 a18263 1 17.7.2 Caveats when using the 'compile' command d18266 1 a18266 1 There are a few caveats to keep in mind when using the 'compile' d18271 3 a18273 3 When the language in GDB is set to 'C', the compiler will attempt to compile the source code with a 'C' compiler. The source code provided to the 'compile' command will have much the same access to d18302 1 a18302 1 has been compiled, loaded into GDB, stopped at the function 'main', d18307 2 a18308 2 'compile' command is not an exception to this rule. Without debug information, you can still use the 'compile' command, but you will d18312 1 a18312 1 debug information enabled. The 'compile' command will have access d18315 5 a18319 5 'main' function, the 'compile' command would have access to the variable 'k'. You could invoke the 'compile' command and type some source code to set the value of 'k'. You can also read it, or do anything with that variable you would normally do in 'C'. Be aware that changes to inferior variables in the 'compile' command are d18324 1 a18324 1 the variable 'k' is now 3. It will retain that value until d18326 1 a18326 1 'compile' command changes it. d18329 3 a18331 3 injected by the 'compile' command. In the example, the variables 'j' and 'k' are not accessible yet, because the program is currently stopped in the 'main' function, where these variables are d18340 1 a18340 1 specify via the 'compile' command will be able to access them. d18342 1 a18342 1 You can create variables and types with the 'compile' command as d18344 1 a18344 1 part of the 'compile' command are not visible to the rest of the d18354 2 a18355 2 a compiler error would be raised as the variable 'ff' no longer exists. Object code generated and injected by the 'compile' d18358 1 a18358 1 the code submitted to the 'compile' command. This example is d18363 2 a18364 2 The value of the variable 'ff' is assigned to 'k'. The variable 'k' does not require the existence of 'ff' to maintain the value it d18366 1 a18366 1 assignment. If the source code compiled with the 'compile' command d18368 1 a18368 1 a variable created in the 'compile' command, that pointer would d18374 1 a18374 1 In this example, 'p' would point to 'ff' when the 'compile' command d18377 1 a18377 1 variable 'p' would point to an invalid location when the command d18379 1 a18379 1 either assign 'NULL' to any assigned pointers, or restore a valid d18383 2 a18384 2 typedefs defined in 'compile' command. Types defined in the 'compile' command will no longer be available in the next 'compile' d18386 1 a18386 1 the 'compile' command, care must be taken to ensure that any future d18397 1 a18397 1 accessible to the code submitted to the 'compile' command. Access d18401 1 a18401 1 17.7.3 Compiler search for the 'compile' command d18406 1 a18406 1 running. Environment variable 'PATH' on GDB host is searched for GCC d18408 1 a18408 1 search can be overridden by 'set compile-gcc' GDB command below. 'PATH' d18410 1 a18410 1 command 'set environment'). *Note Environment::. d18412 2 a18413 2 Specifically 'PATH' is searched for binaries matching regular expression 'ARCH(-[^-]*)?-OS-gcc' according to the inferior target being d18415 3 a18417 3 example both 'i386' and 'x86_64' targets look for pattern '(x86_64|i.86)' and both 's390' and 's390x' targets look for pattern 's390x?'. OS is currently supported only for pattern 'linux(-gnu)?'. d18420 1 a18420 1 library 'libcc1.so' from the compiler. It is searched in default shared d18422 3 a18424 3 'LD_LIBRARY_PATH'), unrelated to 'PATH' or 'set compile-gcc' settings. Contrary to it 'libcc1plugin.so' is found according to the installation of the found compiler -- as possibly specified by the 'set compile-gcc' d18427 1 a18427 1 'set compile-gcc' d18429 1 a18429 1 the 'compile' commands. If this option is not set (it is set to an d18433 1 a18433 1 'show compile-gcc' d18435 2 a18436 2 it is the main command 'gcc', found usually for example under name 'x86_64-linux-gnu-gcc'. d18472 1 a18472 1 to use. Or you are debugging a remote target via 'gdbserver' (*note d18476 1 a18476 1 'file FILENAME' d18479 1 a18479 1 program executed when you use the 'run' command. If you do not d18481 1 a18481 1 directory, GDB uses the environment variable 'PATH' as a list of d18484 1 a18484 1 both GDB and your program, using the 'path' command. d18489 1 a18489 1 You can load unlinked object '.o' files into GDB using the 'file' d18492 2 a18493 2 underlying BFD functionality supports it, you could use 'gdb -write' to patch object files using this technique. Note that GDB d18498 2 a18499 2 'file' 'file' with no argument makes GDB discard any information it has on d18502 1 a18502 1 'exec-file [ FILENAME ]' d18504 1 a18504 1 found in FILENAME. GDB searches the environment variable 'PATH' if d18511 3 a18513 3 'symbol-file [ FILENAME [ -o OFFSET ]]' Read symbol table information from file FILENAME. 'PATH' is searched when necessary. Use the 'file' command to get both symbol d18521 1 a18521 1 'symbol-file' with no argument clears out GDB information on your d18524 1 a18524 1 The 'symbol-file' command causes GDB to forget the contents of some d18530 1 a18530 1 'symbol-file' does not repeat if you press again after d18540 1 a18540 1 usually obtained from GNU compilers; for example, using 'GCC' you d18544 1 a18544 1 systems using COFF, the 'symbol-file' command does not normally d18553 1 a18553 1 source file are being read. (The 'set verbose' command can turn d18558 1 a18558 1 the symbol table is stored in COFF format, 'symbol-file' reads the d18563 2 a18564 2 'symbol-file [ -readnow ] FILENAME' 'file [ -readnow ] FILENAME' d18566 1 a18566 1 tables by using the '-readnow' option with any of the commands that d18570 2 a18571 2 'symbol-file [ -readnever ] FILENAME' 'file [ -readnever ] FILENAME' d18573 1 a18573 1 contained in FILENAME by using the '-readnever' option. *Note d18576 2 a18577 2 'core-file [FILENAME]' 'core' d18583 1 a18583 1 'core-file' with no argument specifies that no core file is to be d18589 1 a18589 1 in which the program is running. To do this, use the 'kill' d18592 2 a18593 2 'add-symbol-file FILENAME [ -readnow | -readnever ] [ -o OFFSET ] [ TEXTADDRESS ] [ -s SECTION ADDRESS ... ]' The 'add-symbol-file' command reads additional symbol table d18599 1 a18599 1 sections using an arbitrary number of '-s SECTION ADDRESS' pairs. d18609 2 a18610 2 originally read with the 'symbol-file' command. You can use the 'add-symbol-file' command any number of times; the new symbol data d18616 1 a18616 1 Changes can be reverted using the command 'remove-symbol-file'. d18621 1 a18621 1 relocatable '.o' files, as long as: d18623 1 a18623 1 * the file's symbolic information refers only to linker symbols d18626 1 a18626 1 * every section the file's symbolic information refers to has d18629 2 a18630 2 * you can determine the address at which every section was loaded, and provide these to the 'add-symbol-file' command. d18636 1 a18636 1 complex link procedures ('.linkonce' section factoring and C++ d18639 1 a18639 1 'add-symbol-file' to read a relocatable object file's symbolic d18643 1 a18643 1 'add-symbol-file' does not repeat if you press after using d18646 3 a18648 3 'remove-symbol-file FILENAME' 'remove-symbol-file -a ADDRESS' Remove a symbol file added via the 'add-symbol-file' command. The d18662 1 a18662 1 'remove-symbol-file' does not repeat if you press after using d18668 1 a18668 1 'add-symbol-file-from-memory ADDRESS' d18671 1 a18671 1 For example, the Linux kernel maps a 'syscall DSO' into each d18675 2 a18676 2 header. For this command to work, you must have used 'symbol-file' or 'exec-file' commands in advance. d18678 2 a18679 2 'section SECTION ADDR' The 'section' command changes the base address of the named SECTION d18681 1 a18681 1 not contain section addresses, (such as in the 'a.out' format), or d18683 1 a18683 1 section must be changed separately. The 'info files' command, d18686 3 a18688 3 'info files' 'info target' 'info files' and 'info target' are synonymous; both print the d18692 1 a18692 1 command 'help target' lists all possible targets rather than d18695 1 a18695 1 'maint info sections [-all-objects] [FILTER-LIST]' d18697 2 a18698 2 sections is 'maint info sections'. In addition to the section information displayed by 'info files', this command displays the d18702 1 a18702 1 When '-all-objects' is passed then sections from all loaded object d18709 1 a18709 1 'SECTION-NAME' d18711 1 a18711 1 'SECTION-FLAG' d18714 1 a18714 1 'ALLOC' d18718 1 a18718 1 'LOAD' d18721 2 a18722 2 clear for '.bss' sections. 'RELOC' d18724 1 a18724 1 'READONLY' d18726 1 a18726 1 'CODE' d18728 1 a18728 1 'DATA' d18730 1 a18730 1 'ROM' d18732 1 a18732 1 'CONSTRUCTOR' d18734 1 a18734 1 'HAS_CONTENTS' d18736 1 a18736 1 'NEVER_LOAD' d18738 1 a18738 1 'COFF_SHARED_LIBRARY' d18741 1 a18741 1 'IS_COMMON' d18744 1 a18744 1 'maint info target-sections' d18750 1 a18750 1 'set trust-readonly-sections on' d18760 1 a18760 1 'set trust-readonly-sections off' d18765 1 a18765 1 'show trust-readonly-sections' d18780 2 a18781 2 you use the 'run' command, or when you examine a core file. (Before you issue the 'run' command, GDB does not understand references to a d18792 2 a18793 2 'set auto-solib-add MODE' If MODE is 'on', symbols from all shared object libraries will be d18796 3 a18798 3 informs GDB that a new library has been loaded. If MODE is 'off', symbols must be loaded manually, using the 'sharedlibrary' command. The default value is 'on'. d18803 1 a18803 1 from shared libraries. To that end, type 'set auto-solib-add off' d18805 1 a18805 1 symbols you do need with 'sharedlibrary REGEXP', where REGEXP is a d18809 1 a18809 1 'show auto-solib-add' d18812 1 a18812 1 To explicitly load shared library symbols, use the 'sharedlibrary' d18815 2 a18816 2 'info share REGEX' 'info sharedlibrary REGEX' d18821 2 a18822 2 'info dll REGEX' This is an alias of 'info sharedlibrary'. d18824 2 a18825 2 'sharedlibrary REGEX' 'share REGEX' d18829 1 a18829 1 after typing 'run'. If REGEX is omitted all shared libraries d18832 1 a18832 1 'nosharedlibrary' d18840 1 a18840 1 'catch load' and 'catch unload' (*note Set Catchpoints::). d18842 1 a18842 1 GDB also supports the 'set stop-on-solib-events' command for this. d18847 1 a18847 1 'set stop-on-solib-events' d18853 1 a18853 1 'show stop-on-solib-events' d18871 1 a18871 1 'set sysroot PATH' d18878 2 a18879 2 to GDB as absolute by the operating system. If you use 'set sysroot' to find executables and shared libraries, they need to be d18881 1 a18881 1 '/bin', '/lib' and '/usr/lib' hierarchy under PATH. d18883 1 a18883 1 If PATH starts with the sequence 'target:' and the target system is d18886 1 a18886 1 supports the 'remote get' command (*note Sending files to a remote d18888 3 a18890 3 'target:' (if present) is used as system root prefix on the remote file system. If PATH starts with the sequence 'remote:' this is converted to the sequence 'target:' by 'set sysroot'(1). If you d18892 2 a18893 2 to be named 'target:' or 'remote:', you need to use some equivalent variant of the name like './target:'. d18901 1 a18901 1 c:\foo\bar.dll => c:/foo/bar.dll d18906 1 a18906 1 c:/foo/bar.dll => /path/to/sysroot/c:/foo/bar.dll d18908 1 a18908 1 If that does not find the binary, GDB tries removing the ':' d18912 1 a18912 1 c:/foo/bar.dll => /path/to/sysroot/c/foo/bar.dll d18916 2 a18917 2 copies of the target system shared libraries like so (note 'c' vs 'z'): d18923 3 a18925 3 and point the system root at '/path/to/sysroot', so that GDB can find the correct copies of both 'c:\sys\bin\foo.dll', and 'z:\sys\bin\bar.dll'. d18930 1 a18930 1 c:/foo/bar.dll => /path/to/sysroot/foo/bar.dll d18935 2 a18936 2 The 'set solib-absolute-prefix' command is an alias for 'set sysroot'. d18939 2 a18940 2 '--with-sysroot' option. If the system root is inside GDB's configured binary prefix (set with '--prefix' or '--exec-prefix'), d18944 1 a18944 1 'show sysroot' d18947 1 a18947 1 'set solib-search-path PATH' d18949 2 a18950 2 directories to search for shared libraries. 'solib-search-path' is used after 'sysroot' fails to locate the library, or if the path to d18952 1 a18952 1 'solib-search-path' instead of 'sysroot', be sure to set 'sysroot' d18954 1 a18954 1 libraries. 'sysroot' is preferred; setting it to a nonexistent d18958 1 a18958 1 'show solib-search-path' d18961 1 a18961 1 'set target-file-system-kind KIND' d18969 2 a18970 2 'c:\Windows\kernel32.dll'. On Unix hosts, there's no concept of drive letters, so the 'c:\' prefix is not normally understood as d18976 3 a18978 3 target's shared libraries on the host using 'set sysroot', and impractical with 'set solib-search-path'. Setting 'target-file-system-kind' to 'dos-based' tells GDB to interpret d18981 1 a18981 1 value of KIND can be '"auto"', in addition to one of the supported d18987 1 a18987 1 'unix' d18989 1 a18989 1 Only file names starting the forward slash ('/') character are d18993 1 a18993 1 'dos-based' d18996 2 a18997 2 letter followed by a colon (e.g., 'c:'), are considered absolute, and both the slash ('/') and the backslash ('\\') d19000 1 a19000 1 'auto' d19007 1 a19007 1 Normally, GDB compares just the "base names" of the files as strings, d19015 1 a19015 1 symlinks etc., you can set 'basenames-may-differ' to 'true' to instruct d19020 1 a19020 1 'set basenames-may-differ' d19023 1 a19023 1 'show basenames-may-differ' d19029 1 a19029 1 remote system was provided by prefixing PATH with 'remote:' d19038 1 a19038 1 'bfd' objects used to track open files. *Note BFD: (bfd)Top. The d19041 2 a19042 2 'maint info bfds' This prints information about each 'bfd' object that is known to d19045 4 a19048 4 'maint set bfd-sharing' 'maint show bfd-sharing' Control whether 'bfd' objects can be shared. When sharing is enabled GDB reuses already open 'bfd' objects rather than reopening d19050 4 a19053 4 'bfd' objects to be unshared, but all future files that are opened will create a new 'bfd' object. Similarly, re-enabling sharing does not cause multiple existing 'bfd' objects to be collapsed into a single shared 'bfd' object. d19055 1 a19055 1 'set debug bfd-cache LEVEL' d19058 1 a19058 1 'show debug bfd-cache' d19077 1 a19077 1 * The executable contains a "debug link" that specifies the name of d19079 1 a19079 1 usually 'EXECUTABLE.debug', where EXECUTABLE is the name of the d19081 2 a19082 2 'ls.debug' for '/usr/bin/ls'). In addition, the debug link specifies a 32-bit "Cyclic Redundancy Check" (CRC) checksum for the d19086 1 a19086 1 * The executable contains a "build ID", a unique bit string that is d19090 1 a19090 1 details about this feature, see the description of the '--build-id' d19098 1 a19098 1 * For the "debug link" method, GDB looks up the named file in the d19100 1 a19100 1 directory named '.debug', and finally under each one of the global d19105 1 a19105 1 'd:/usr/bin/' is converted to '/d/usr/bin/', because Windows d19108 1 a19108 1 * For the "build ID" method, GDB looks in the '.build-id' d19110 1 a19110 1 named 'NN/NNNNNNNN.debug', where NN are the first 2 hex characters d19113 1 a19113 1 10.) GDB can automatically query 'debuginfod' servers using build d19117 4 a19120 4 So, for example, suppose you ask GDB to debug '/usr/bin/ls', which has a debug link that specifies the file 'ls.debug', and a build ID whose value in hex is 'abcdef1234'. If the list of the global debug directories includes '/usr/lib/debug', then GDB will look for the d19123 4 a19126 4 - '/usr/lib/debug/.build-id/ab/cdef1234.debug' - '/usr/bin/ls.debug' - '/usr/bin/.debug/ls.debug' - '/usr/lib/debug/usr/bin/ls.debug'. d19128 1 a19128 1 If the debug file still has not been found and 'debuginfod' (*note d19130 1 a19130 1 'debuginfod' servers. d19133 1 a19133 1 configure option '--with-separate-debug-dir' and augmented by the d19135 1 a19135 1 '--additional-debug-dirs'. During GDB run you can also set the global d19138 1 a19138 1 'set debug-file-directory DIRECTORIES' d19143 1 a19143 1 'show debug-file-directory' d19148 1 a19148 1 '.gnu_debuglink'. The section must contain: d19150 1 a19150 1 * A filename, with any leading directory components removed, followed d19152 1 a19152 1 * zero to three bytes of padding, as needed to reach the next d19154 1 a19154 1 * a four-byte CRC checksum, stored in the same endianness used for d19160 1 a19160 1 contain a section named '.gnu_debuglink' with the contents described d19165 1 a19165 1 named '.note.gnu.build-id', but that name is not mandatory. It contains d19177 1 a19177 1 but they need not contain any data--much like a '.bss' section in an d19180 1 a19180 1 The GNU binary utilities (Binutils) package includes the 'objcopy' d19188 1 a19188 1 'foo' and place it in the file 'foo.debug'. You can use the first, d19191 2 a19192 2 * The debug link method needs the following additional command to also leave behind a debug link in 'foo': d19196 4 a19199 4 Ulrich Drepper's 'elfutils' package, starting with version 0.53, contains a version of the 'strip' command such that the command 'strip foo -f foo.debug' has the same functionality as the two 'objcopy' commands and the 'ln -s' command above, together. d19201 2 a19202 2 * Build ID gets embedded into the main executable using 'ld --build-id' or the GCC counterpart 'gcc -Wl,--build-id'. Build ID d19207 1 a19207 2 The CRC used in '.gnu_debuglink' is the CRC-32 defined in IEEE 802.3 d19214 1 a19214 1 bit of each byte first. The initial pattern '0xffffffff' is used, to d19219 1 a19219 1 "Remote Serial Protocol" 'qCRC' packet (*note qCRC packet::). However d19225 2 a19226 2 which produces the CRC used in '.gnu_debuglink'. Inverting the initially supplied 'crc' argument means that an initial call to this d19228 1 a19228 1 '0xffffffff'. d19306 2 a19307 2 special '.gnu_debugdata' section. This feature is called "MiniDebugInfo". This section holds an LZMA-compressed object and is d19321 1 a19321 1 This section can be easily created using 'objcopy' and other standard d19368 1 a19368 1 For convenience, GDB comes with a program, 'gdb-add-index', which can d19377 1 a19377 1 'gdb-add-index' does behind the curtains. d19381 1 a19381 1 'objcopy'. d19383 1 a19383 1 To create an index file, use the 'save gdb-index' command: d19385 1 a19385 1 'save gdb-index [-dwarf-5] DIRECTORY' d19388 3 a19390 3 produces a single file 'SYMBOL-FILE.gdb-index'. If you invoke this command with the '-dwarf-5' option, it produces 2 files: 'SYMBOL-FILE.debug_names' and 'SYMBOL-FILE.debug_str'. The files d19394 1 a19394 1 file, here named 'symfile', using 'objcopy': d19399 1 a19399 1 Or for '-dwarf-5': d19407 1 a19407 1 GDB will normally ignore older versions of '.gdb_index' sections that d19410 2 a19411 2 deprecated index section anyway specify 'set use-deprecated-index-sections on'. The default is 'off'. This can d19415 1 a19415 1 _Warning:_ Setting 'use-deprecated-index-sections' to 'on' must be d19431 2 a19432 2 the future. This feature can be turned on with 'set index-cache enabled on'. The following commands can be used to tweak the behavior of the d19435 2 a19436 2 'set index-cache enabled on' 'set index-cache enabled off' d19439 2 a19440 2 'set index-cache directory DIRECTORY' 'show index-cache directory' d19444 3 a19446 3 On most systems, the index is cached in the 'gdb' subdirectory of the directory pointed to by the 'XDG_CACHE_HOME' environment variable, if it is defined, else in the '.cache/gdb' subdirectory d19454 1 a19454 1 'show index-cache stats' d19460 1 a19460 1 18.6 Extensions to '.debug_names' d19464 1 a19464 1 '.debug_names'. GDB can both read and create this section. However, in d19467 2 a19468 2 GDB uses the augmentation string 'GDB2'. Earlier versions used the string 'GDB', but these versions of the index are no longer supported. d19474 7 a19480 7 'DW_IDX_GNU_internal' This has the value '0x2000'. It is a flag that, when set, indicates that the associated entry has 'static' linkage. 'DW_IDX_GNU_main' This has the value '0x2002'. It is a flag that, when set, indicates that the associated entry is the program's 'main'. d19482 2 a19483 2 'DW_IDX_GNU_language' This has the value '0x2003'. It is 'DW_LANG_' constant, indicating d19486 2 a19487 2 'DW_IDX_GNU_linkage_name' This has the value '0x2004'. It is a flag that, when set, d19505 1 a19505 1 many times the problems occur, with the 'set complaints' command (*note d19510 1 a19510 1 'inner block not inside outer block in SYMBOL' d19519 1 a19519 1 SYMBOL may be shown as "'(don't know)'" if the outer block is not a d19522 1 a19522 1 'block at ADDRESS out of order' d19530 2 a19531 2 often determine what source file is affected by specifying 'set verbose on'. *Note Optional Warnings and Messages: d19534 1 a19534 1 'bad block start address patched' d19543 1 a19543 1 'bad string table offset in symbol N' d19549 1 a19549 1 name 'foo', which may cause other problems if many symbols end up d19552 1 a19552 1 'unknown symbol type 0xNN' d19555 1 a19555 1 yet know how to read. '0xNN' is the symbol type of the d19561 3 a19563 3 feel like debugging it, you can debug 'gdb' with itself, breakpoint on 'complain', then go up to the function 'read_dbx_symtab' and examine '*bufp' to see the symbol. d19565 1 a19565 1 'stub type has NULL name' d19569 1 a19569 1 'const/volatile indicator missing (ok if using g++ v1.x), got...' d19574 1 a19574 1 'info mismatch between compiler and debugger' d19585 1 a19585 1 a directory known as the "data directory". d19590 1 a19590 1 'set data-directory DIRECTORY' d19594 1 a19594 1 'show data-directory' d19598 2 a19599 2 '--with-gdb-datadir' option. If the data directory is inside GDB's configured binary prefix (set with '--prefix' or '--exec-prefix'), then d19603 1 a19603 1 The data directory may also be specified with the '--data-directory' d19612 1 a19612 1 A "target" is the execution environment occupied by your program. d19616 1 a19616 1 the 'file' or 'core' commands. When you need more flexibility--for d19619 1 a19619 1 connection--you can use the 'target' command to specify one of the d19623 3 a19625 3 It is possible to build GDB for several different "target architectures". When GDB is built like that, you can choose one of the available architectures with the 'set architecture' command. d19627 1 a19627 1 'set architecture ARCH' d19629 1 a19629 1 value of ARCH can be '"auto"', in addition to one of the supported d19632 1 a19632 1 'show architecture' d19635 4 a19638 4 'set processor' 'processor' These are alias commands for, respectively, 'set architecture' and 'show architecture'. d19659 1 a19659 1 and 'reverse-step' there, you are presented a virtual layer of the d19663 1 a19663 1 Use the 'core-file' and 'exec-file' commands to select a new core d19665 1 a19665 1 specify as a target a process that is already running, use the 'attach' d19674 1 a19674 1 'target TYPE PARAMETERS' d19684 1 a19684 1 The 'target' command does not repeat if you press again after d19687 1 a19687 1 'help target' d19689 1 a19689 1 currently selected, use either 'info target' or 'info files' (*note d19692 1 a19692 1 'help target NAME' d19696 1 a19696 1 'set gnutarget ARGS' d19698 3 a19700 3 it is reading an "executable", a "core", or a ".o" file; however, you can specify the file format with the 'set gnutarget' command. Unlike most 'target' commands, with 'gnutarget' the 'target' refers d19703 1 a19703 1 _Warning:_ To specify a file format with 'set gnutarget', you d19708 3 a19710 3 'show gnutarget' Use the 'show gnutarget' command to display what file format 'gnutarget' is set to read. If you have not set 'gnutarget', GDB d19712 1 a19712 1 'show gnutarget' displays 'The current BFD target is "auto"'. d19717 7 a19723 7 'target exec PROGRAM' An executable file. 'target exec PROGRAM' is the same as 'exec-file PROGRAM'. 'target core FILENAME' A core dump file. 'target core FILENAME' is the same as 'core-file FILENAME'. d19725 1 a19725 1 'target remote MEDIUM' d19730 1 a19730 1 For example, if you have a board connected to '/dev/ttya' on the d19735 1 a19735 1 'target remote' supports the 'load' command. This is only useful d19740 1 a19740 1 'target sim [SIMARGS] ...' d19752 4 a19755 4 'target native' Setup for local/native process debugging. Useful to make the 'run' command spawn native processes (likewise 'attach', etc.) even when 'set auto-connect-native-target' is 'off' (*note set d19765 2 a19766 2 'set hash' This command controls whether a hash mark '#' is displayed while d19771 1 a19771 1 'show hash' d19774 1 a19774 1 'set debug monitor' d19778 1 a19778 1 'show debug monitor' d19782 1 a19782 1 'load FILENAME OFFSET' d19784 1 a19784 1 GDB, the 'load' command may be available. Where it exists, it is d19787 2 a19788 2 'load' also records the FILENAME symbol table in GDB, like the 'add-symbol-file' command. d19790 3 a19792 3 If your GDB does not have a 'load' command, attempting to execute it gets the error message "'You can't do that when your target is ...'" d19806 1 a19806 1 'load' does not repeat if you press again after using it. d19808 1 a19808 1 'flash-erase' d19825 1 a19825 1 'set endian big' d19828 1 a19828 1 'set endian little' d19831 1 a19831 1 'set endian auto' d19834 1 a19834 1 'show endian' d19837 1 a19837 1 If the 'set endian auto' mode is in effect and no executable has been d19839 1 a19839 1 of the 'set endian big' and 'set endian little' commands or by inferring d19842 2 a19843 2 has been built for, and is 'little' if the name of the target CPU has an 'el' suffix and 'big' otherwise. d19869 1 a19869 1 use 'help target' to list them. d19893 3 a19895 3 GDB supports two types of remote connections, 'target remote' mode and 'target extended-remote' mode. Note that many remote targets support only 'target remote' mode. There are several major differences between d19901 1 a19901 1 'gdbserver', 'gdbserver' will exit. d19906 1 a19906 1 a running program, or use 'monitor' commands specific to the d19909 3 a19911 3 When using 'gdbserver' in this case, it does not exit unless it was invoked using the '--once' option. If the '--once' option was not used, you can ask 'gdbserver' to exit using the 'monitor exit' d19915 2 a19916 2 For both connection types you use the 'file' command to specify the program on the host system. If you are using 'gdbserver' there are d19921 1 a19921 1 debug on the 'gdbserver' command line or use the '--attach' option d19925 2 a19926 2 debug on the 'gdbserver' command line, or you can load the program or attach to it using GDB commands after connecting to 'gdbserver'. d19928 3 a19930 3 You can start 'gdbserver' without supplying an initial command to run or process ID to attach. To do this, use the '--multi' command line option. Then you can connect using 'target extended-remote' d19932 4 a19935 4 using the 'run' command in this scenario). Note that the conditions under which 'gdbserver' terminates depend on how GDB connects to it ('target remote' or 'target extended-remote'). The '--multi' option to 'gdbserver' has no influence on that. d19937 2 a19938 2 The 'run' command *With target remote mode:* The 'run' command is not supported. d19941 2 a19942 2 already running, so you can use commands like 'step' and 'continue'. d19944 2 a19945 2 *With target extended-remote mode:* The 'run' command is supported. The 'run' command uses the value set by 'set remote exec-file' d19951 3 a19953 3 'run' command is not required to start execution, and you can resume using commands like 'step' and 'continue' as with 'target remote' mode. d19956 3 a19958 3 *With target remote mode:* The GDB command 'attach' is not supported. To attach to a running program using 'gdbserver', you must use the '--attach' option (*note Running gdbserver::). d19961 3 a19963 3 you may use the 'attach' command after the connection has been established. If you are using 'gdbserver', you may also invoke 'gdbserver' using the '--attach' option (*note Running d19968 1 a19968 1 case, GDB uses the value of 'exec-file-mismatch' to handle a d19980 1 a19980 1 'target remote' mode and 'target extended-remote' mode. d19985 2 a19986 2 the remote program is unstripped, the only command you need is 'target remote' (or 'target extended-remote'). d19990 2 a19991 2 unstripped copy of your program as the first argument, or use the 'file' command. Use 'set sysroot' to specify the location (on the host) of d19993 2 a19994 2 using '--with-sysroot'). Alternatively, you may use 'set solib-search-path' to specify how GDB locates target libraries. d20001 1 a20001 1 also prevent 'gdbserver' from debugging multi-threaded programs. d20009 2 a20010 2 carrying the debugging packets varies. The 'target remote' and 'target extended-remote' commands establish a connection to the target. Both d20013 2 a20014 2 'target remote SERIAL-DEVICE' 'target extended-remote SERIAL-DEVICE' d20016 1 a20016 1 use a serial line connected to the device named '/dev/ttyb': d20021 2 a20022 2 '--baud' option, or use the 'set serial baud' command (*note set serial baud: Remote Configuration.) before the 'target' command. d20024 2 a20025 2 'target remote LOCAL-SOCKET' 'target extended-remote LOCAL-SOCKET' d20028 1 a20028 1 '/tmp/gdb-socket0': d20038 14 a20051 14 'target remote HOST:PORT' 'target remote [HOST]:PORT' 'target remote tcp:HOST:PORT' 'target remote tcp:[HOST]:PORT' 'target remote tcp4:HOST:PORT' 'target remote tcp6:HOST:PORT' 'target remote tcp6:[HOST]:PORT' 'target extended-remote HOST:PORT' 'target extended-remote [HOST]:PORT' 'target extended-remote tcp:HOST:PORT' 'target extended-remote tcp:[HOST]:PORT' 'target extended-remote tcp4:HOST:PORT' 'target extended-remote tcp6:HOST:PORT' 'target extended-remote tcp6:[HOST]:PORT' d20061 1 a20061 1 'manyfarms': d20066 1 a20066 1 '2001:0db8:85a3:0000:0000:8a2e:0370:7334', you can either use the d20091 10 a20100 10 'target remote udp:HOST:PORT' 'target remote udp:[HOST]:PORT' 'target remote udp4:HOST:PORT' 'target remote udp6:[HOST]:PORT' 'target extended-remote udp:HOST:PORT' 'target extended-remote udp:HOST:PORT' 'target extended-remote udp:[HOST]:PORT' 'target extended-remote udp4:HOST:PORT' 'target extended-remote udp6:HOST:PORT' 'target extended-remote udp6:[HOST]:PORT' d20102 1 a20102 1 to UDP port 2828 on a terminal server named 'manyfarms': d20111 2 a20112 2 'target remote | COMMAND' 'target extended-remote | COMMAND' d20115 1 a20115 1 system's command shell, '/bin/sh'; it should expect remote protocol d20119 1 a20119 1 programs like 'ssh', or for other similar tricks. d20122 1 a20122 1 will try to send it a 'SIGTERM' signal. (If the program has d20126 1 a20126 1 interrupt character (often 'Ctrl-c'), GDB attempts to stop the program. d20134 1 a20134 1 In 'target remote' mode, if you type 'y', GDB abandons the remote d20136 1 a20136 1 use 'target remote' again to connect once more.) If you type 'n', GDB d20139 1 a20139 1 In 'target extended-remote' mode, typing 'n' will leave GDB connected d20142 1 a20142 1 'detach' d20144 1 a20144 1 the 'detach' command to release it from GDB control. Detaching d20146 3 a20148 3 will depend on your particular remote stub. After the 'detach' command in 'target remote' mode, GDB is free to connect to another target. In 'target extended-remote' mode, GDB is still connected d20151 2 a20152 2 'disconnect' The 'disconnect' command closes the connection to the target, and d20155 1 a20155 1 the 'disconnect' command, GDB is again free to connect to another d20158 1 a20158 1 'monitor CMD' d20174 1 a20174 1 'gdbserver' over a network interface. For other targets, e.g. embedded d20180 1 a20180 1 'remote put HOSTFILE TARGETFILE' d20184 1 a20184 1 'remote get TARGETFILE HOSTFILE' d20188 1 a20188 1 'remote delete TARGETFILE' d20194 1 a20194 1 20.3 Using the 'gdbserver' Program d20197 3 a20199 3 'gdbserver' is a control program for Unix-like systems, which allows you to connect your program with a remote GDB via 'target remote' or 'target extended-remote'--but without linking in the usual debugging stub. d20201 1 a20201 1 'gdbserver' is not a complete replacement for the debugging stubs, d20203 2 a20204 2 that GDB itself does. In fact, a system that can run 'gdbserver' to connect to a remote GDB could also run GDB locally! 'gdbserver' is d20207 1 a20207 1 able to get started more quickly on a new system by using 'gdbserver'. d20211 1 a20211 1 by cross-compiling. You can use 'gdbserver' to make a similar choice d20214 1 a20214 1 GDB and 'gdbserver' communicate via either a serial line or a TCP d20217 4 a20220 4 _Warning:_ 'gdbserver' does not have any built-in security. Do not run 'gdbserver' connected to any public network; a GDB connection to 'gdbserver' provides access to the target system with the same privileges as the user running 'gdbserver'. d20222 1 a20222 1 20.3.1 Running 'gdbserver' d20225 2 a20226 2 Run 'gdbserver' on the target system. You need a copy of the program you want to debug, including any libraries it requires. 'gdbserver' d20238 3 a20240 3 hostname and portnumber, or '-' or 'stdio' to use stdin/stdout of 'gdbserver'. For example, to debug Emacs with the argument 'foo.txt' and communicate with GDB over the serial port '/dev/com1': d20244 1 a20244 1 'gdbserver' waits passively for the host GDB to communicate with it. d20252 3 a20254 3 'host:2345' argument means that 'gdbserver' is to expect a TCP connection from machine 'host' to local TCP port 2345. (Currently, the 'host' part is ignored.) You can choose any number you want for the d20256 3 a20258 3 in use on the target system (for example, '23' is reserved for 'telnet').(1) You must use the same port number with the host GDB 'target remote' command. d20260 1 a20260 1 The 'stdio' connection is useful when starting 'gdbserver' with ssh: d20264 1 a20264 1 The '-T' option to ssh is provided because we don't need a remote d20269 3 a20271 3 Programs started with stdio-connected gdbserver have '/dev/null' for 'stdin', and 'stdout','stderr' are sent back to gdb for display through a pipe connected to gdbserver. Both 'stdout' and 'stderr' use the same d20277 2 a20278 2 On some targets, 'gdbserver' can also attach to running programs. This is accomplished via the '--attach' argument. The syntax is: d20283 1 a20283 1 necessary to point 'gdbserver' at a binary for the running process. d20285 1 a20285 1 In 'target extended-remote' mode, you can also attach using the GDB d20289 1 a20289 1 has the 'pidof' utility: d20294 1 a20294 1 multiple threads, most versions of 'pidof' support the '-s' option to d20297 1 a20297 1 20.3.1.2 TCP port allocation lifecycle of 'gdbserver' d20300 1 a20300 1 This section applies only when 'gdbserver' is run to listen on a TCP d20303 3 a20305 3 'gdbserver' normally terminates after all of its debugged processes have terminated in 'target remote' mode. On the other hand, for 'target extended-remote', 'gdbserver' stays running even with no processes left. d20307 1 a20307 1 normally also terminates 'gdbserver' in the 'target remote' mode. d20309 2 a20310 2 'gdbserver' to kill its debugged processes, 'gdbserver' stays running even in the 'target remote' mode. d20312 1 a20312 1 When 'gdbserver' stays running, GDB can connect to it again later. d20317 3 a20319 3 By default, 'gdbserver' keeps the listening TCP port open, so that subsequent connections are possible. However, if you start 'gdbserver' with the '--once' option, it will stop listening for any further d20321 2 a20322 2 means no further connections to 'gdbserver' will be possible after the first one. It also means 'gdbserver' will terminate after the first d20324 1 a20324 1 connections and even in the 'target extended-remote' mode. The '--once' d20326 1 a20326 1 instances of 'gdbserver' running on the same host, since each instance d20329 1 a20329 1 20.3.1.3 Other Command-Line Arguments for 'gdbserver' d20332 1 a20332 1 You can use the '--multi' option to start 'gdbserver' without specifying d20334 1 a20334 1 'target extended-remote' mode and run or attach to a program. For more d20337 1 a20337 1 The '--debug[=option1,option2,...]' option tells 'gdbserver' to d20339 1 a20339 1 options (OPTION1, OPTION2, etc) control for which areas of 'gdbserver' d20342 1 a20342 1 'all' d20344 1 a20344 1 'threads' d20347 2 a20348 2 this could change in future releases of 'gdbserver'. 'event-loop' d20350 1 a20350 1 'remote' d20354 4 a20357 4 If no options are passed to '--debug' then this is treated as equivalent to '--debug=threads'. This could change in future releases of 'gdbserver'. The options passed to '--debug' are processed left to right, and individual options can be prefixed with the '-' (minus) d20365 1 a20365 1 The '--debug-file=FILENAME' option tells 'gdbserver' to write any d20367 1 a20367 1 'gdbserver' development and for bug reports to the developers. d20369 1 a20369 1 The '--debug-format=option1[,option2,...]' option tells 'gdbserver' d20372 1 a20372 1 'none' d20374 1 a20374 1 'all' d20376 1 a20376 1 'timestamps' d20379 1 a20379 1 Options are processed in order. Thus, for example, if 'none' appears d20382 1 a20382 1 The '--wrapper' option specifies a wrapper to launch programs for d20384 1 a20384 1 then any command-line arguments to pass to the wrapper, then '--' d20387 1 a20387 1 'gdbserver' runs the specified wrapper program with a combined d20392 1 a20392 1 You can use any program that eventually calls 'execve' with its d20394 1 a20394 1 'env' and 'nohup'. Any Unix shell script ending with 'exec "$@@"' will d20397 2 a20398 2 For example, you can use 'env' to pass an environment variable to the debugged program, without setting the variable in 'gdbserver''s d20403 1 a20403 1 The '--selftest' option runs the self tests in 'gdbserver': d20410 1 a20410 1 20.3.2 Connecting to 'gdbserver' d20415 1 a20415 1 * Run GDB on the host system. d20417 1 a20417 1 * Make sure you have the necessary symbol files (*note Host and d20419 1 a20419 1 'file' command before you connect. Use 'set sysroot' to locate d20421 1 a20421 1 sysroot using '--with-sysroot'). d20423 3 a20425 3 * Connect to your target (*note Connecting to a Remote Target: Connecting.). For TCP connections, you must start up 'gdbserver' prior to using the 'target' command. Otherwise you may get an d20427 2 a20428 2 looks something like 'Connection refused'. Don't use the 'load' command in GDB when using 'target remote' mode, since the program d20431 1 a20431 1 20.3.3 Monitor Commands for 'gdbserver' d20434 2 a20435 2 During a GDB session using 'gdbserver', you can use the 'monitor' command to send special requests to 'gdbserver'. Here are the available d20438 1 a20438 1 'monitor help' d20441 1 a20441 1 'monitor set debug off' d20444 1 a20444 1 'monitor set debug on' d20446 1 a20446 1 is equivalent to 'monitor set debug threads on', but this might d20449 2 a20450 2 'monitor set debug threads off' 'monitor set debug threads on' d20456 2 a20457 2 'monitor set debug remote off' 'monitor set debug remote on' d20461 2 a20462 2 'monitor set debug event-loop off' 'monitor set debug event-loop on' d20466 2 a20467 2 'monitor set debug-file filename' 'monitor set debug-file' d20470 1 a20470 1 'monitor set debug-format option1[,option2,...]' d20474 1 a20474 1 'none' d20476 1 a20476 1 'all' d20478 1 a20478 1 'timestamps' d20481 1 a20481 1 Options are processed in order. Thus, for example, if 'none' d20485 1 a20485 1 'monitor set libthread-db-search-path [PATH]' d20487 1 a20487 1 directories to search for 'libthread_db' (*note set d20489 1 a20489 1 'libthread-db-search-path' will be reset to its default value. d20491 2 a20492 2 The special entry '$pdir' for 'libthread-db-search-path' is not supported in 'gdbserver'. d20494 1 a20494 1 'monitor exit' d20496 3 a20498 3 followed by 'disconnect' to close the debugging session. 'gdbserver' will detach from any attached processes and kill any processes it created. Use 'monitor exit' to terminate 'gdbserver' d20501 1 a20501 1 20.3.4 Tracepoints support in 'gdbserver' d20504 1 a20504 1 On some targets, 'gdbserver' supports tracepoints, fast tracepoints and d20508 2 a20509 2 "in-process agent" (IPA), must be loaded in the inferior process. This library is built and distributed as an integral part of 'gdbserver'. In d20515 3 a20517 3 'gdbserver' is built, or if 'gdbserver' was explicitly configured using '--with-ust' to point at such headers. You can explicitly disable the support using '--with-ust=no'. d20521 1 a20521 1 'Specifying it as dependency at link time' d20525 1 a20525 1 '-linproctrace' to the link command. d20527 1 a20527 1 'Using the system's preloading mechanisms' d20532 3 a20534 3 cases, you do that by specifying 'LD_PRELOAD=libinproctrace.so' in the environment. See also the description of 'gdbserver''s '--wrapper' command line option. d20536 1 a20536 1 'Using GDB to force loading the agent at run time' d20541 2 a20542 2 On most Unix systems, the function is 'dlopen'. You'll use the 'call' command for that. For example: d20546 2 a20547 2 Note that on most Unix systems, for the 'dlopen' function to be available, the program needs to be linked with '-ldl'. d20550 1 a20550 1 systems, when you connect to 'gdbserver' using 'target remote', you'll d20557 1 a20557 1 C++ program, start 'gdbserver' like so: d20561 1 a20561 1 Start GDB and connect to 'gdbserver' like so, and run to main: d20570 2 a20571 2 process; you can confirm it with the 'info sharedlibrary' command, which will list 'libinproctrace.so' as loaded in the process. You are now d20578 1 a20578 1 'gdbserver' prints an error message and exits. d20591 1 a20591 1 'set remoteaddresssize BITS' d20597 1 a20597 1 'show remoteaddresssize' d20600 1 a20600 1 'set serial baud N' d20605 1 a20605 1 'show serial baud' d20608 1 a20608 1 'set serial parity PARITY' d20610 1 a20610 1 PARITY are: 'even', 'none', and 'odd'. The default is 'none'. d20612 1 a20612 1 'show serial parity' d20615 5 a20619 5 'set remotebreak' If set to on, GDB sends a 'BREAK' signal to the remote when you type 'Ctrl-c' to interrupt the program running on the remote. If set to off, GDB sends the 'Ctrl-C' character instead. The default is off, since most remote systems expect to see 'Ctrl-C' as the d20622 2 a20623 2 'show remotebreak' Show whether GDB sends 'BREAK' or 'Ctrl-C' to interrupt the remote d20626 3 a20628 3 'set remoteflow on' 'set remoteflow off' Enable or disable hardware flow control ('RTS'/'CTS') on the serial d20631 1 a20631 1 'show remoteflow' d20634 1 a20634 1 'set remotelogbase BASE' d20636 2 a20637 2 communications to BASE. Supported values of BASE are: 'ascii', 'octal', and 'hex'. The default is 'ascii'. d20639 1 a20639 1 'show remotelogbase' d20643 1 a20643 1 'set remotelogfile FILE' d20647 1 a20647 1 'show remotelogfile' d20651 1 a20651 1 'set remotetimeout NUM' d20655 1 a20655 1 'show remotetimeout' d20659 2 a20660 2 'set remote hardware-watchpoint-limit LIMIT' 'set remote hardware-breakpoint-limit LIMIT' d20663 1 a20663 1 watchpoints or breakpoints, and 'unlimited' for unlimited d20666 2 a20667 2 'show remote hardware-watchpoint-limit' 'show remote hardware-breakpoint-limit' d20671 1 a20671 1 'set remote hardware-watchpoint-length-limit LIMIT' d20674 1 a20674 1 watchpoints and 'unlimited' allows watchpoints of any length. d20676 1 a20676 1 'show remote hardware-watchpoint-length-limit' d20680 3 a20682 3 'set remote exec-file FILENAME' 'show remote exec-file' Select the file used for 'run' with 'target extended-remote'. This d20687 2 a20688 2 'set remote interrupt-sequence' Allow the user to select one of 'Ctrl-C', a 'BREAK' or 'BREAK-g' as d20690 1 a20690 1 execution. 'Ctrl-C' is a default. Some system prefers 'BREAK' d20692 2 a20693 2 kernel prefers 'BREAK-g', a.k.a Magic SysRq g. It is 'BREAK' signal followed by character 'g'. d20695 4 a20698 4 'show remote interrupt-sequence' Show which of 'Ctrl-C', 'BREAK' or 'BREAK-g' is sent by GDB to interrupt the remote program. 'BREAK-g' is BREAK signal followed by 'g' and also known as Magic SysRq g. d20700 1 a20700 1 'set remote interrupt-on-connect' d20703 1 a20703 1 kernel. Linux kernel expects 'BREAK' followed by 'g' which is d20706 1 a20706 1 'show remote interrupt-on-connect' d20710 1 a20710 1 'set tcp auto-retry on' d20717 1 a20717 1 by 'set tcp connect-timeout'. d20719 1 a20719 1 'set tcp auto-retry off' d20722 1 a20722 1 'show tcp auto-retry' d20725 2 a20726 2 'set tcp connect-timeout SECONDS' 'set tcp connect-timeout unlimited' d20729 1 a20729 1 failed connections (enabled by 'set tcp auto-retry on') and waiting d20731 1 a20731 1 approximate cumulative value. If SECONDS is 'unlimited', there is d20733 1 a20733 1 forever, unless interrupted with 'Ctrl-c'. The default is 15 d20736 1 a20736 1 'show tcp connect-timeout' d20742 3 a20744 3 be set to 'on' (the remote target supports this packet), 'off' (the remote target does not support this packet), or 'auto' (detect remote target support for this packet). They all default to 'auto'. For more d20752 1 a20752 1 'set remote NAME-packet'. If you configure a packet, the configuration d20757 1 a20757 1 'show remote NAME-packet'. It displays the current remote target's d20764 1 a20764 1 'fetch-register' 'p' 'info registers' d20766 1 a20766 1 'set-register' 'P' 'set' d20768 1 a20768 1 'binary-download' 'X' 'load', 'set' d20770 1 a20770 1 'read-aux-vector' 'qXfer:auxv:read' 'info auxv' d20772 1 a20772 1 'symbol-lookup' 'qSymbol' Detecting d20775 1 a20775 1 'attach' 'vAttach' 'attach' d20777 1 a20777 1 'verbose-resume' 'vCont' Stepping or d20781 1 a20781 1 'run' 'vRun' 'run' d20783 1 a20783 1 'software-breakpoint''Z0' 'break' d20785 1 a20785 1 'hardware-breakpoint''Z1' 'hbreak' d20787 1 a20787 1 'write-watchpoint' 'Z2' 'watch' d20789 1 a20789 1 'read-watchpoint' 'Z3' 'rwatch' d20791 1 a20791 1 'access-watchpoint' 'Z4' 'awatch' d20793 1 a20793 1 'pid-to-exec-file' 'qXfer:exec-file:read' 'attach', 'run' d20795 2 a20796 2 'target-features' 'qXfer:features:read' 'set architecture' d20798 2 a20799 2 'library-info' 'qXfer:libraries:read' 'info sharedlibrary' d20801 1 a20801 1 'memory-map' 'qXfer:memory-map:read' 'info mem' d20803 1 a20803 1 'read-sdata-object' 'qXfer:sdata:read' 'print $_sdata' d20805 2 a20806 2 'read-siginfo-object''qXfer:siginfo:read' 'print $_siginfo' d20808 1 a20808 1 'write-siginfo-object''qXfer:siginfo:write' 'set $_siginfo' d20810 1 a20810 1 'threads' 'qXfer:threads:read' 'info threads' d20812 2 a20813 2 'get-thread-local- 'qGetTLSAddr' Displaying storage-address' '__thread' d20816 1 a20816 1 'get-thread-information-block-address''qGetTIBAddr'Display d20822 1 a20822 1 'search-memory' 'qSearch:memory' 'find' d20824 1 a20824 1 'supported-packets' 'qSupported' Remote d20828 1 a20828 1 'catch-syscalls' 'QCatchSyscalls' 'catch syscall' d20830 1 a20830 1 'pass-signals' 'QPassSignals' 'handle SIGNAL' d20832 1 a20832 1 'program-signals' 'QProgramSignals' 'handle SIGNAL' d20834 2 a20835 2 'hostio-close-packet''vFile:close' 'remote get', 'remote put' d20837 2 a20838 2 'hostio-open-packet' 'vFile:open' 'remote get', 'remote put' d20840 2 a20841 2 'hostio-pread-packet''vFile:pread' 'remote get', 'remote put' d20843 2 a20844 2 'hostio-pwrite-packet''vFile:pwrite' 'remote get', 'remote put' d20846 1 a20846 1 'hostio-unlink-packet''vFile:unlink' 'remote delete' d20848 1 a20848 1 'hostio-readlink-packet''vFile:readlink' Host I/O d20850 1 a20850 1 'hostio-fstat-packet''vFile:fstat' Host I/O d20852 1 a20852 1 'hostio-setfs-packet''vFile:setfs' Host I/O d20854 1 a20854 1 'noack-packet' 'QStartNoAckMode' Packet d20857 1 a20857 1 'osdata' 'qXfer:osdata:read' 'info os' d20859 1 a20859 1 'query-attached' 'qAttached' Querying remote d20863 2 a20864 2 'trace-buffer-size' 'QTBuffer:size' 'set trace-buffer-size' d20866 1 a20866 1 'trace-status' 'qTStatus' 'tstatus' d20868 1 a20868 1 'traceframe-info' 'qXfer:traceframe-info:read'Traceframe info d20870 1 a20870 1 'install-in-trace' 'InstallInTrace' Install d20874 2 a20875 2 'disable-randomization''QDisableRandomization''set disable-randomization' d20877 2 a20878 2 'startup-with-shell' 'QStartupWithShell' 'set startup-with-shell' d20880 2 a20881 2 'environment-hex-encoded''QEnvironmentHexEncoded''set environment' d20883 2 a20884 2 'environment-unset' 'QEnvironmentUnset' 'unset environment' d20886 1 a20886 1 'environment-reset' 'QEnvironmentReset' 'Reset the d20891 1 a20891 1 variables)' d20893 1 a20893 1 'set-working-dir' 'QSetWorkingDir' 'set cwd' d20895 1 a20895 1 'conditional-breakpoints-packet''Z0 and Z1' 'Support for d20899 1 a20899 1 evaluation' d20901 2 a20902 2 'multiprocess-extensions''multiprocess Debug multiple extensions' processes and d20906 1 a20906 1 'swbreak-feature' 'swbreak stop reason' 'break' d20908 1 a20908 1 'hwbreak-feature' 'hwbreak stop reason' 'hbreak' d20910 1 a20910 1 'fork-event-feature' 'fork stop reason' 'fork' d20912 1 a20912 1 'vfork-event-feature''vfork stop reason' 'vfork' d20914 1 a20914 1 'exec-event-feature' 'exec stop reason' 'exec' d20916 1 a20916 1 'thread-events' 'QThreadEvents' Tracking thread d20919 1 a20919 1 'thread-options' 'QThreadOptions' Set thread event d20923 2 a20924 2 'no-resumed-stop-reply''no resumed thread Tracking thread left stop reply' lifetime. d20929 2 a20930 2 'set remote memory-read-packet-size' and 'set remote memory-write-packet-size'. If set to '0' (zero) the default d20932 2 a20933 2 on the target. Specify 'fixed' to disable the target-dependent restriction and 'limit' to enable it. Similar to the enabling and d20938 2 a20939 2 'show remote memory-read-packet-size' and 'show remote memory-write-packet-size'. If no remote target is d20950 1 a20950 1 source file 'remote.c'. Normally, you can simply allow these d20953 1 a20953 1 with one of the existing stub files. 'sparc-stub.c' is the best d20956 1 a20956 1 To debug a program running on another machine (the debugging "target" d20961 1 a20961 1 usually have a name like 'crt0'. The startup routine may be d20974 1 a20974 1 communicate with the machine where GDB is running (the "host" machine). d20979 1 a20979 1 else is set up, you can simply use the 'target remote' command d20985 1 a20985 1 these subroutines is called a "debugging stub". d20988 2 a20989 2 'gdbserver' instead of linking a stub into your program. *Note Using the 'gdbserver' Program: Server, for details. d20992 1 a20992 1 machine; for example, use 'sparc-stub.c' to debug programs on SPARC d20997 1 a20997 1 'i386-stub.c' d21000 1 a21000 1 'm68k-stub.c' d21003 1 a21003 1 'sh-stub.c' d21006 1 a21006 1 'sparc-stub.c' d21009 1 a21009 1 'sparcl-stub.c' d21012 1 a21012 1 The 'README' file in the GDB distribution may list other recently d21030 2 a21031 2 'set_debug_traps' This routine arranges for 'handle_exception' to run when your d21035 1 a21035 1 'handle_exception' d21037 1 a21037 1 explicitly--the setup code arranges for 'handle_exception' to run d21040 1 a21040 1 'handle_exception' takes control when your program stops during d21043 1 a21043 1 communications protocol is implemented; 'handle_exception' acts as d21048 1 a21048 1 that point, 'handle_exception' returns control to your own code on d21051 1 a21051 1 'breakpoint' d21057 1 a21057 1 'handle_exception'--in effect, to GDB. On some machines, simply d21059 2 a21060 2 again, in that situation, you don't need to call 'breakpoint' from your own program--simply running 'target remote' from the host GDB d21063 1 a21063 1 Call 'breakpoint' if none of these is true, or if you simply want d21080 1 a21080 1 'int getDebugChar()' d21082 1 a21082 1 port. It may be identical to 'getchar' for your target system; a d21086 1 a21086 1 'void putDebugChar(int)' d21088 1 a21088 1 port. It may be identical to 'putchar' for your target system; a d21094 1 a21094 1 stop when it receives a '^C' ('\003', the control-C character). That is d21100 1 a21100 1 GDB reports a 'SIGTRAP' instead of a 'SIGINT'). d21104 1 a21104 1 'void exceptionHandler (int EXCEPTION_NUMBER, void *EXCEPTION_ADDRESS)' d21124 1 a21124 1 without help from 'exceptionHandler'. d21126 1 a21126 1 'void flush_i_cache()' d21136 2 a21137 2 'void *memset(void *, int, int)' This is the standard library function 'memset' that sets an area of d21139 1 a21139 1 'libc.a', 'memset' can be found there; otherwise, you must either d21145 1 a21145 1 subroutines which 'GCC' generates as inline code. d21158 2 a21159 2 'getDebugChar', 'putDebugChar', 'flush_i_cache', 'memset', 'exceptionHandler'. d21170 1 a21170 1 adjust 'handle_exception' to arrange for it to return to the d21176 1 a21176 1 'exceptionHook'. Normally you just use: d21180 2 a21181 2 but if before calling 'set_debug_traps', you set it to point to a function in your program, that function is called when 'GDB' d21183 2 a21184 2 function indicated by 'exceptionHook' is called with one parameter: an 'int' which is the exception number. d21250 1 a21250 1 many native BSD configurations. This is implemented as a special 'kvm' d21252 1 a21252 1 running kernel into GDB and connect to the 'kvm' target: d21261 1 a21261 1 Once connected to the 'kvm' target, the following commands are d21264 2 a21265 2 'kvm pcb' Set current context from the "Process Control Block" (PCB) address. d21267 1 a21267 1 'kvm proc' d21280 1 a21280 1 supported interface, the command 'info proc' is available to report d21284 1 a21284 1 One supported interface is a facility called '/proc' that can be used d21296 2 a21297 2 'info proc' 'info proc PROCESS-ID' d21305 1 a21305 1 On some systems, PROCESS-ID can be of the form '[PID]/TID' which d21308 1 a21308 1 debugged (the leading '/' still needs to be present, or else GDB d21311 1 a21311 1 'info proc cmdline' d21315 1 a21315 1 'info proc cwd' d21319 1 a21319 1 'info proc exe' d21323 1 a21323 1 'info proc files' d21350 1 a21350 1 'info proc mappings' d21358 2 a21359 2 'info proc stat' 'info proc status' d21363 1 a21363 1 time; its stack size; its 'nice' value; etc. These commands are d21366 2 a21367 2 For GNU/Linux systems, see the 'proc' man page for more information (type 'man 5 proc' from your shell prompt). d21369 2 a21370 2 For FreeBSD and NetBSD systems, 'info proc stat' is an alias for 'info proc status'. d21372 1 a21372 1 'info proc all' d21374 1 a21374 1 the above 'info proc' subcommands. d21376 2 a21377 2 'set procfs-trace' This command enables and disables tracing of 'procfs' API calls. d21379 2 a21380 2 'show procfs-trace' Show the current state of 'procfs' API call tracing. d21382 2 a21383 2 'set procfs-file FILE' Tell GDB to write 'procfs' API trace to the named FILE. GDB d21387 2 a21388 2 'show procfs-file' Show the file to which 'procfs' API trace is written. d21390 4 a21393 4 'proc-trace-entry' 'proc-trace-exit' 'proc-untrace-entry' 'proc-untrace-exit' d21395 1 a21395 1 from the 'syscall' interface. d21397 1 a21397 1 'info pidlist' d21401 1 a21401 1 'info meminfo' d21412 1 a21412 1 DJGPP programs are 32-bit protected-mode programs that use the "DPMI" d21420 1 a21420 1 'info dos' d21424 1 a21424 1 'info dos sysinfo' d21429 3 a21431 3 'info dos gdt' 'info dos ldt' 'info dos idt' d21458 1 a21458 1 outside the data segment's limit (i.e. "garbled"). d21460 2 a21461 2 'info dos pde' 'info dos pte' d21471 2 a21472 2 Without an argument, 'info dos pde' displays the entire Page Directory, and 'info dos pte' displays all the entries in all of d21474 2 a21475 2 'info dos pde' command means display only that entry from the Page Directory table. An argument given to the 'info dos pte' command d21479 1 a21479 1 These commands are useful when your program uses "DMA" (Direct d21485 1 a21485 1 'info dos address-pte ADDR' d21491 1 a21491 1 for the page where a variable 'i' is stored: d21497 2 a21498 2 This says that 'i' is stored at offset '0xd30' from the page whose physical base address is '0x02698000', and shows all the attributes d21501 2 a21502 2 Note that you must cast the addresses of variables to a 'char *', since otherwise the value of '__djgpp_base_address', the base d21504 3 a21506 3 added using the rules of C pointer arithmetic: if 'i' is declared an 'int', GDB will add 4 times the value of '__djgpp_base_address' to the address of 'i'. d21515 2 a21516 2 (The '+ 3' offset is because the transfer buffer's address is the 3rd member of the '_go32_info_block' structure.) The output d21518 2 a21519 2 conventional memory 1:1, i.e. the physical ('0x00029000' + '0x110') and linear ('0x29110') addresses are identical. d21527 2 a21528 2 'set com1base ADDR' This command sets the base I/O port address of the 'COM1' serial d21531 3 a21533 3 'set com1irq IRQ' This command sets the "Interrupt Request" ('IRQ') line to use for the 'COM1' serial port. d21535 2 a21536 2 There are similar commands 'set com2base', 'set com3irq', etc. for setting the port address and the 'IRQ' lines for the other 3 COM d21539 2 a21540 2 The related commands 'show com1base', 'show com1irq' etc. display the current settings of the base address and the 'IRQ' lines used d21543 1 a21543 1 'info serial' d21558 3 a21560 3 MS-Windows programs that call 'SetConsoleMode' to switch off the special meaning of the 'Ctrl-C' keystroke cannot be interrupted by typing 'C-c'. For this reason, GDB on MS-Windows supports 'C-' d21562 1 a21562 1 the debuggee even if it ignores 'C-c'. d21568 1 a21568 1 'info w32' d21572 1 a21572 1 'info w32 selector' d21574 1 a21574 1 'GetThreadSelectorEntry' function. It takes an optional argument d21579 1 a21579 1 'info w32 thread-information-block' d21582 1 a21582 1 '$fs' selector for 32-bit programs and '$gs' for 64-bit programs). d21584 1 a21584 1 'signal-event ID' d21590 7 a21596 7 'HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug' and/or 'HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\AeDebug' (for x86_64 versions): - 'Debugger' (REG_SZ) -- a command to launch the debugger. Suggested command is: 'FULLY-QUALIFIED-PATH-TO-GDB.EXE -ex "attach %ld" -ex "signal-event %ld" -ex "continue"'. d21598 2 a21599 2 The first '%ld' will be replaced by the process ID of the crashing process, the second '%ld' will be replaced by the ID d21603 1 a21603 1 - 'Auto' (REG_SZ) -- either '1' or '0'. '1' will make the d21605 1 a21605 1 automatically, '0' will cause a dialog box with "OK" and d21609 3 a21611 3 'set cygwin-exceptions MODE' If MODE is 'on', GDB will break on exceptions that happen inside the Cygwin DLL. If MODE is 'off', GDB will delay recognition of d21615 1 a21615 1 'off' to avoid annoying GDB users with false 'SIGSEGV' signals. d21617 1 a21617 1 'show cygwin-exceptions' d21621 3 a21623 3 'set new-console MODE' If MODE is 'on' the debuggee will be started in a new console on next start. If MODE is 'off', the debuggee will be started in the d21626 1 a21626 1 'show new-console' d21630 1 a21630 1 'set new-group MODE' d21633 1 a21633 1 way the Windows OS handles 'Ctrl-C'. d21635 1 a21635 1 'show new-group' d21638 1 a21638 1 'set debugevents' d21643 1 a21643 1 the Windows 'OutputDebugString' API call. d21645 1 a21645 1 'set debugexec' d21649 1 a21649 1 'set debugexceptions' d21653 1 a21653 1 'set debugmemory' d21657 1 a21657 1 'set shell' d21661 1 a21661 1 'show shell' d21676 1 a21676 1 'kernel32.dll'). When GDB doesn't recognize any debugging symbols in a d21691 2 a21692 2 DLL name, for instance 'KERNEL32!CreateFileA'. The plain name is also entered into the symbol table, so 'CreateFileA' is often sufficient. In d21702 2 a21703 2 If in doubt, try the 'info functions' and 'info variables' commands or even 'maint print msymbols' (*note Symbols::). Here's an example: d21766 1 a21766 1 a break point within a shared DLL like 'kernel32.dll' is completely d21778 2 a21779 2 'set signals' 'set sigs' d21782 1 a21782 1 by this command. 'sigs' is a shorthand alias for 'signals'. d21784 2 a21785 2 'show signals' 'show sigs' d21788 3 a21790 3 'set signal-thread' 'set sigthread' This command tells GDB which thread is the 'libc' signal thread. d21792 1 a21792 1 'set sigthread' is the shorthand alias of 'set signal-thread'. d21794 2 a21795 2 'show signal-thread' 'show sigthread' d21799 1 a21799 1 'set stopped' d21801 1 a21801 1 with the 'SIGSTOP' signal. The stopped process can be continued by d21804 1 a21804 1 'show stopped' d21807 1 a21807 1 'set exceptions' d21813 1 a21813 1 'show exceptions' d21816 1 a21816 1 'set task pause' d21821 1 a21821 1 you can use 'set thread default pause on' or 'set thread pause on' d21824 1 a21824 1 'show task pause' d21827 1 a21827 1 'set task detach-suspend-count' d21831 1 a21831 1 'show task detach-suspend-count' d21834 2 a21835 2 'set task exception-port' 'set task excp' d21837 2 a21838 2 exceptions. The argument should be the value of the "send rights" of the task. 'set task excp' is a shorthand alias. d21840 1 a21840 1 'set noninvasive' d21843 1 a21843 1 same as using 'set task pause', 'set exceptions', and 'set signals' d21846 7 a21852 7 'info send-rights' 'info receive-rights' 'info port-rights' 'info port-sets' 'info dead-names' 'info ports' 'info psets' d21855 2 a21856 2 task. There are also shorthand aliases: 'info ports' for 'info port-rights' and 'info psets' for 'info port-sets'. d21858 1 a21858 1 'set thread pause' d21864 2 a21865 2 the whole task is suspended. However, if you used 'set task pause off' (see above), this command comes in handy to suspend only the d21868 1 a21868 1 'show thread pause' d21871 1 a21871 1 'set thread run' d21874 1 a21874 1 'show thread run' d21877 1 a21877 1 'set thread detach-suspend-count' d21880 2 a21881 2 GDB when it notices the thread; use 'set thread takeover-suspend-count' to force it to an absolute value. d21883 1 a21883 1 'show thread detach-suspend-count' d21886 2 a21887 2 'set thread exception-port' 'set thread excp' d21889 2 a21890 2 overrides the port set by 'set task exception-port' (see above). 'set thread excp' is the shorthand alias. d21892 1 a21892 1 'set thread takeover-suspend-count' d21897 5 a21901 5 'set thread default' 'show thread default' Each of the above 'set thread' commands has a 'set thread default' counterpart (e.g., 'set thread default pause', 'set thread default exception-port', etc.). The 'thread default' variety of commands d21914 1 a21914 1 'set debug darwin NUM' d21918 1 a21918 1 'show debug darwin' d21921 1 a21921 1 'set debug mach-o NUM' d21923 1 a21923 1 is reading Darwin object files. ("Mach-O" is the file format used d21928 1 a21928 1 'show debug mach-o' d21931 2 a21932 2 'set mach-exceptions on' 'set mach-exceptions off' d21939 1 a21939 1 'show mach-exceptions' d21955 2 a21956 2 For example, FreeBSD 12 introduced a new variant of the 'kevent' system call and catching the 'kevent' system call by name catches both d21988 1 a21988 1 'sim COMMAND' d22015 1 a22015 1 'set debug arc' d22020 1 a22020 1 'show debug arc' d22023 1 a22023 1 'maint print arc arc-instruction ADDRESS' d22035 1 a22035 1 'set arm disassembler' d22037 1 a22037 1 '"std"' style is the standard style. d22039 1 a22039 1 'show arm disassembler' d22042 1 a22042 1 'set arm apcs32' d22045 1 a22045 1 'show arm apcs32' d22048 1 a22048 1 'set arm fpu FPUTYPE' d22052 1 a22052 1 'auto' d22054 1 a22054 1 'softfpa' d22057 1 a22057 1 'fpa' d22059 1 a22059 1 'softvfp' d22061 1 a22061 1 'vfp' d22064 1 a22064 1 'show arm fpu' d22067 1 a22067 1 'set arm abi' d22070 1 a22070 1 'show arm abi' d22073 1 a22073 1 'set arm fallback-mode (arm|thumb|auto)' d22077 2 a22078 2 'auto', which causes GDB to use the current execution mode (from the 'T' bit in the 'CPSR' register). d22080 1 a22080 1 'show arm fallback-mode' d22083 1 a22083 1 'set arm force-mode (arm|thumb|auto)' d22085 3 a22087 3 instructions are ARM or Thumb. The default is 'auto', which causes GDB to use the symbol table and then the setting of 'set arm fallback-mode'. d22089 1 a22089 1 'show arm force-mode' d22092 1 a22092 1 'set arm unwind-secure-frames' d22098 1 a22098 1 'show arm unwind-secure-frames' d22101 1 a22101 1 'set debug arm' d22105 1 a22105 1 'show debug arm' d22108 1 a22108 1 'target sim [SIMARGS] ...' d22111 1 a22111 1 '--swi-support=TYPE' d22114 1 a22114 1 values. The default value is 'all'. d22116 5 a22120 5 'none' 'demon' 'angel' 'redboot' 'all' d22128 1 a22128 1 'target sim [SIMARGS] ...' d22131 1 a22131 1 '--skb-data-offset=OFFSET' d22133 1 a22133 1 'skb_data' field in the kernel 'struct sk_buff' structure. d22158 3 a22160 3 a 'gdbserver' interface to the board. By default 'xmd' uses port '1234'. (While it is possible to change this default port, it requires the use of undocumented 'xmd' commands. Contact Xilinx support if you d22165 1 a22165 1 'target remote :1234' d22167 1 a22167 1 the same system as 'xmd'. d22169 1 a22169 1 'target remote XMD-HOST:1234' d22171 1 a22171 1 'xmd' running on a different system named XMD-HOST. d22173 1 a22173 1 'load' d22176 1 a22176 1 'set debug microblaze N' d22179 1 a22179 1 'show debug microblaze N' d22190 5 a22194 5 'set mipsfpu double' 'set mipsfpu single' 'set mipsfpu none' 'set mipsfpu auto' 'show mipsfpu' d22196 1 a22196 1 coprocessor, you should use the command 'set mipsfpu none' (if you d22203 3 a22205 3 the command 'set mipsfpu single'. The default double precision floating point coprocessor may be selected using 'set mipsfpu double'. d22208 2 a22209 2 floating point, so 'set mipsfpu on' will select double precision and 'set mipsfpu off' will select no floating point. d22211 2 a22212 2 As usual, you can inquire about the 'mipsfpu' variable with 'show mipsfpu'. d22227 1 a22227 1 'target sim' d22232 1 a22232 1 and connect using 'target remote'. d22234 1 a22234 1 Example: 'target sim' d22236 1 a22236 1 'set debug or1k' d22240 1 a22240 1 'show debug or1k' d22257 1 a22257 1 debug register (either the 'exact-watchpoints' option is on and the d22263 1 a22263 1 ranged hardware watchpoints, unless the 'exact-watchpoints' option is d22274 1 a22274 1 discussion about the 'mask' argument in *note Set Watchpoints::. d22276 2 a22277 2 PowerPC embedded processors support hardware accelerated "ranged breakpoints". A ranged breakpoint stops execution of the inferior d22279 1 a22279 1 was set at. To set a ranged breakpoint in GDB, use the 'break-range' d22284 1 a22284 1 'break-range START-LOCSPEC, END-LOCSPEC' d22297 2 a22298 2 'set powerpc soft-float' 'show powerpc soft-float' d22303 2 a22304 2 'set powerpc vector-abi' 'show powerpc vector-abi' d22306 3 a22308 3 arguments and return values. The valid options are 'auto'; 'generic', to avoid vector registers even if they are present; 'altivec', to use AltiVec registers; and 'spe' to use SPE d22312 2 a22313 2 'set powerpc exact-watchpoints' 'show powerpc exact-watchpoints' d22327 1 a22327 1 'info io_registers' d22340 2 a22341 2 'set cris-version VER' Set the current CRIS version to VER, either '10' or '32'. The CRIS d22345 1 a22345 1 'show cris-version' d22348 1 a22348 1 'set cris-dwarf2-cfi' d22350 2 a22351 2 'on'. Change to 'off' when using 'gcc-cris' whose version is below 'R59'. d22353 1 a22353 1 'show cris-dwarf2-cfi' d22356 1 a22356 1 'set cris-mode MODE' d22358 2 a22359 2 debugging in guru mode, in which case it should be set to 'guru' (the default is 'normal'). d22361 1 a22361 1 'show cris-mode' d22372 1 a22372 1 'set sh calling-convention CONVENTION' d22374 2 a22375 2 Allowed values are 'gcc', which is the default setting, and 'renesas'. With the 'gcc' setting, functions are called using the d22379 1 a22379 1 convention. If the calling convention is set to 'renesas', the d22382 1 a22382 1 'gcc' if debug information is missing, or the compiler does not d22385 1 a22385 1 'show sh calling-convention' d22419 1 a22419 1 'set debug aarch64' d22423 1 a22423 1 'show debug aarch64' d22431 2 a22432 2 '$z0' through '$z31', vector predicate registers '$p0' through '$p15', and the '$ffr' register. In addition, the pseudo register '$vg' will be d22434 1 a22434 1 represents the number of 64-bit chunks in an SVE 'z' register. d22436 2 a22437 2 If the vector length changes, then the '$vg' register will be updated, but the lengths of the 'z' and 'p' registers will not change. d22444 1 a22444 1 * VL: The vector length, in bytes. It defines the size of each 'Z' d22447 1 a22447 1 * VQ: The number of 128 bit units in VL. This is mostly used d22450 1 a22450 1 * VG: The number of 64 bit units in VL. This is mostly used d22461 1 a22461 1 by providing a 2-dimensional register 'ZA', which is a square matrix of d22465 2 a22466 2 Similarly to SVE, where the size of each 'Z' register is directly related to the vector length (VL for short), the SME 'ZA' matrix d22470 1 a22470 1 The 'ZA' register state can be either active or inactive, if it is d22486 3 a22488 3 * SVL: The streaming vector length, in bytes. It defines the size of each dimension of the 2-dimensional square 'ZA' matrix. The total size of 'ZA' is therefore SVL by SVL. d22493 1 a22493 1 * SVQ: The number of 128 bit units in SVL, also known as streaming d22497 1 a22497 1 * SVG: The number of 64 bit units in SVL. This is mostly used d22501 2 a22502 2 Matrix Extension (SME) is present, then GDB will make the 'ZA' register available. GDB will also make the 'SVG' register and 'SVCR' d22505 2 a22506 2 The 'ZA' register is a 2-dimensional square SVL by SVL matrix of bytes. To simplify the representation and access to the 'ZA' register d22509 2 a22510 2 If the user wants to index the 'ZA' register as a matrix, it is possible to reference 'ZA' as 'ZA[I][J]', where I is the row number and d22513 2 a22514 2 The 'SVG' register always contains the streaming vector granule (SVG) for the current thread. From the value of register 'SVG' we can easily d22517 1 a22517 1 The 'SVCR' pseudo-register (streaming vector control register) is a d22525 2 a22526 2 If the ZA bit is 1, it means the 'ZA' register is being used and has meaningful contents. If the ZA bit is 0, the 'ZA' register is d22529 1 a22529 1 For convenience and simplicity, if the ZA bit is 0, the 'ZA' register d22532 2 a22533 2 If SVL changes during the execution of a program, then the 'ZA' register size and the bits in the 'SVCR' pseudo-register will be updated d22537 1 a22537 1 program by modifying the 'SVG' register value. d22539 1 a22539 1 Whenever the 'SVG' register is modified with a new value, the d22542 1 a22542 1 * The ZA and SM bits will be cleared in the 'SVCR' pseudo-register. d22544 1 a22544 1 * The 'ZA' register will have a new size and its state will be d22548 1 a22548 1 * If the SM bit was 1, the SVE registers will be reset to having d22550 1 a22550 1 prior to modifying the 'SVG' register, there will be no observable d22553 1 a22553 1 The possible values for the 'SVG' register are 2, 4, 8, 16, 32. d22557 1 a22557 1 The minimum size of the 'ZA' register is 16 x 16 (256) bytes, and the d22559 1 a22559 1 set, the size of the 'ZA' register is the size of all the SVE 'Z' d22562 1 a22562 1 The 'ZA' register can also be accessed using tiles and tile slices. d22565 1 a22565 1 elements within the 'ZA' register. d22567 2 a22568 2 The tile pseudo-registers have the following naming pattern: 'ZA'. d22570 3 a22572 3 There is a total of 31 'ZA' tile pseudo-registers. They are 'ZA0B', 'ZA0H' through 'ZA1H', 'ZA0S' through 'ZA3S', 'ZA0D' through 'ZA7D' and 'ZA0Q' through 'ZA15Q'. d22575 1 a22575 1 contiguous elements within the 'ZA' register. d22578 1 a22578 1 'ZA '. d22580 3 a22582 3 There are up to 16 tiles (0 ~ 15), the direction can be either 'v' (vertical) or 'h' (horizontal), the qualifiers can be 'b' (byte), 'h' (halfword), 's' (word), 'd' (doubleword) and 'q' (quadword) and there d22592 1 a22592 1 currently-available 'ZA' pseudo-registers. Pseudo-registers that don't d22608 1 a22608 1 the 'SVCR' pseudo-register bits nor the 'ZA' register contents. *Note d22613 2 a22614 2 involving the 'TPIDR2' register is not yet supported by GDB, though the 'TPIDR2' register is known and supported by GDB. d22616 2 a22617 2 Lastly, an important limitation for 'gdbserver' is its inability to communicate SVL changes to GDB. This means 'gdbserver', even though it d22621 1 a22621 1 values for the 'ZA' register and incorrect values for SVE registers d22633 2 a22634 2 * The ability to address the 'ZA' array through groups of one-dimensional 'ZA' array vectors, as opposed to 'ZA' tiles with 2 d22637 1 a22637 1 * Instructions to operate on groups of SVE 'Z' registers and 'ZA' d22640 1 a22640 1 * A new 512 bit 'ZT0' lookup table register, for data decompression. d22643 1 a22643 1 Matrix Extension 2 (SME2) is present, then GDB will make the 'ZT0' d22646 2 a22647 2 The 'ZT0' register is only considered active when the 'ZA' register state is active, therefore when the ZA bit of the 'SVCR' is 1. d22649 2 a22650 2 When the ZA bit of 'SVCR' is 0, that means the 'ZA' register state is not active, which means the 'ZT0' register state is also not active. d22652 1 a22652 1 When 'ZT0' is not active, it is comprised of zeroes, just like 'ZA'. d22654 1 a22654 1 Similarly to the 'ZA' register, if the 'ZT0' state is not active and d22656 2 a22657 2 non-zero, then GDB will initialize the 'ZA' register state as well, which means the 'SVCR' ZA bit gets set to 1. d22668 1 a22668 1 register '$lr' is pointing to an PAC function its value will be masked. d22671 1 a22671 1 as part of the 'addr_flags' field. d22699 4 a22702 4 A special register, 'tag_ctl', is made available through the 'org.gnu.gdb.aarch64.mte' feature. This register exposes some options that can be controlled at runtime and emulates the 'prctl' option 'PR_SET_TAGGED_ADDR_CTRL'. For further information, see the d22706 2 a22707 2 'gcore' command and reading memory tag data from core files generated by the 'gcore' command or the Linux kernel. d22715 2 a22716 2 tags from a particular memory region (using the 'm' modifier to the 'x' command, using the 'print' command or using the various 'memory-tag' d22730 6 a22735 6 'set struct-convention MODE' Set the convention used by the inferior to return 'struct's and 'union's from functions to MODE. Possible values of MODE are '"pcc"', '"reg"', and '"default"' (the default). '"default"' or '"pcc"' means that 'struct's are returned on the stack, while '"reg"' means that a 'struct' or a 'union' whose size is 1, 2, 4, d22738 2 a22739 2 'show struct-convention' Show the current setting of the convention to return 'struct's from d22742 1 a22742 1 21.4.2.1 Intel "Memory Protection Extensions" (MPX). d22745 2 a22746 2 Memory Protection Extension (MPX) adds the bound registers 'BND0' (1) through 'BND3'. Bound registers store a pair of 64-bit values which are d22753 2 a22754 2 'BND0' through 'BND3' are represented in GDB as 'bnd0raw' through 'bnd3raw'. Pseudo registers 'bnd0' through 'bnd3' display the upper d22756 2 a22757 2 value, i.e. when upper bound in 'bnd0raw' is 0 in the GDB 'bnd0' it will be '0xfff...'. In this sense it can also be noted that the upper bounds d22780 1 a22780 1 'show mpx bound POINTER' d22783 1 a22783 1 'set mpx bound POINTER, LBOUND, UBOUND' d22825 9 a22833 9 * '$st0' to 'st7': 'ST(0)' to 'ST(7)' floating-point registers * '$fctrl': control word register ('FCW') * '$fstat': status word register ('FSW') * '$ftag': tag word ('FTW') * '$fiseg': last instruction pointer segment * '$fioff': last instruction pointer * '$foseg': last data pointer segment * '$fooff': last data pointer * '$fop': last opcode d22862 1 a22862 1 'set heuristic-fence-post LIMIT' d22866 1 a22866 1 bytes 'heuristic-fence-post' must search and therefore the longer d22870 1 a22870 1 'show heuristic-fence-post' d22879 1 a22879 1 'set mips abi ARG' d22883 1 a22883 1 'auto' d22886 6 a22891 6 'o32' 'o64' 'n32' 'n64' 'eabi32' 'eabi64' d22893 1 a22893 1 'show mips abi' d22896 1 a22896 1 'set mips compression ARG' d22905 2 a22906 2 Possible values of ARG are 'mips16' and 'micromips'. The default compressed ISA encoding is 'mips16', as executables containing d22919 1 a22919 1 'show mips compression' d22923 2 a22924 2 'set mipsfpu' 'show mipsfpu' d22927 1 a22927 1 'set mips mask-address ARG' d22930 1 a22930 1 'on', 'off', or 'auto'. The latter is the default setting, which d22933 1 a22933 1 'show mips mask-address' d22937 1 a22937 1 'set remote-mips64-transfers-32bit-regs' d22941 1 a22941 1 and 64 bits for other registers, set this option to 'on'. d22943 1 a22943 1 'show remote-mips64-transfers-32bit-regs' d22947 1 a22947 1 'set debug mips' d22951 1 a22951 1 'show debug mips' d22963 1 a22963 1 'set debug hppa' d22967 1 a22967 1 'show debug hppa' d22970 1 a22970 1 'maint print unwind ADDRESS' d22984 1 a22984 1 register like 'f0' or 'f2'. d22986 3 a22988 3 The pseudo-registers go from '$dl0' through '$dl15', and are formed by joining the even/odd register pairs 'f0' and 'f1' for '$dl0', 'f2' and 'f3' for '$dl1' and so on. d22991 1 a22991 1 64-bit wide Extended Floating Point Registers ('f32' through 'f63'). d23002 1 a23002 1 'set debug nios2' d23006 1 a23006 1 'show debug nios2' d23036 1 a23036 1 'adi (examine | x) [ / N ] ADDR' d23038 1 a23038 1 The 'adi examine' command displays the value of one ADI version tag d23054 1 a23054 1 'adi (assign | a) [ / N ] ADDR = TAG' d23056 1 a23056 1 The 'adi assign' command is used to assign new ADI version tag to d23084 1 a23084 1 'maint info bdccsr' d23142 1 a23142 1 The 'info sharedlibrary' command will show the AMD GPU code objects as d23157 1 a23157 1 For a 'file' URI, the path portion is the file on disk containing the d23163 1 a23163 1 For a 'memory' URI, the path portion is the process id of the process d23169 1 a23169 1 The 'info sharedlibrary' command may therefore show the same code object d23191 1 a23191 1 'SIGILL' d23194 2 a23195 2 'SIGTRAP' Execution of a 'S_TRAP' instruction other than: d23197 1 a23197 1 * 'S_TRAP 1' which is used by GDB to insert breakpoints. d23199 1 a23199 1 * 'S_TRAP 2' which raises 'SIGABRT'. d23201 2 a23202 2 'SIGABRT' Execution of a 'S_TRAP 2' instruction. d23204 1 a23204 1 'SIGFPE' d23209 1 a23209 1 * Floating point operation is invalid. d23211 1 a23211 1 * Floating point operation had subnormal input that was rounded d23214 1 a23214 1 * Floating point operation performed a division by zero. d23216 1 a23216 1 * Floating point operation produced an overflow result. The d23219 1 a23219 1 * Floating point operation produced an underflow result. A d23222 1 a23222 1 * Floating point operation produced an inexact result. d23224 1 a23224 1 * Integer operation performed a division by zero. d23227 1 a23227 1 'set $mode' command can be used to change the AMD GPU wavefront's d23229 1 a23229 1 raise signals. The 'print $trapsts' command can be used to inspect d23233 1 a23233 1 'SIGBUS' d23237 1 a23237 1 'SIGSEGV' d23253 1 a23253 1 'set amdgpu precise-memory MODE' d23257 1 a23257 1 'off' d23262 1 a23262 1 'on' d23269 2 a23270 2 The 'amdgpu precise-memory' parameter is per-inferior. When an inferior forks or execs, or the user uses the 'clone-inferior' d23274 1 a23274 1 'show amdgpu precise-memory' d23280 2 a23281 2 The 'set debug amd-dbgapi' command can be used to enable diagnostic messages in the 'amd-dbgapi' target. The 'show debug amd-dbgapi' d23284 4 a23287 4 The 'set debug amd-dbgapi-lib log-level LEVEL' command can be used to enable diagnostic messages from the 'amd-dbgapi' library (which GDB uses under the hood). The 'show debug amd-dbgapi-lib log-level' command displays the current 'amd-dbgapi' library log level. *Note set debug d23313 2 a23314 2 Setting the 'HIP_ENABLE_DEFERRED_LOADING' environment variable to '0' can be used to disable deferred code object loading by the HIP d23316 1 a23316 1 inferior reaches the beginning of the 'main' function. d23318 1 a23318 1 3. If no CPU thread is running, then 'Ctrl-C' is not able to stop AMD d23320 1 a23320 1 'scheduler-locking' after the whole program stopped, and then d23328 2 a23329 2 the wavefront's work-group position. The 'info threads' command will display this missing information with a '?'. d23334 1 a23334 1 If the 'HSA_ENABLE_DEBUG' environment variable is set to '1' when d23345 1 a23345 1 You can alter the way GDB interacts with you by using the 'set' command. d23370 2 a23371 2 called the "prompt". This string is normally '(gdb)'. You can change the prompt string with the 'set prompt' command. For instance, when d23375 1 a23375 1 _Note:_ 'set prompt' does not add a space for you after the prompt d23379 1 a23379 1 'set prompt NEWPROMPT' d23382 2 a23383 2 'show prompt' Prints a line of the form: 'Gdb's prompt is: YOUR-PROMPT' d23388 1 a23388 1 'set extended-prompt PROMPT' d23402 1 a23402 1 'show extended-prompt' d23404 1 a23404 1 of the prompt string with 'set extended-prompt', are replaced with d23413 1 a23413 1 GDB reads its input commands via the "Readline" interface. This GNU d23416 1 a23416 1 "vi"-style inline editing of commands, 'csh'-like history substitution, d23420 1 a23420 1 command 'set'. d23422 2 a23423 2 'set editing' 'set editing on' d23426 1 a23426 1 'set editing off' d23429 1 a23429 1 'show editing' d23433 1 a23433 1 interface. Users unfamiliar with GNU Emacs or 'vi' are encouraged to d23436 2 a23437 2 GDB sets the Readline application name to 'gdb'. This is useful for conditions in '.inputrc'. d23439 2 a23440 2 GDB defines a bindable Readline command, 'operate-and-get-next'. This is bound to 'C-o' by default. This command accepts the current d23459 1 a23459 1 state which is seen by users, prefix it with 'server ' (*note Server d23466 1 a23466 1 history, use the 'output' command instead of the 'print' command. d23470 1 a23470 1 'set history filename [FNAME]' d23476 2 a23477 2 defaults to the value of the environment variable 'GDBHISTFILE', or to './.gdb_history' ('./_gdb_history' on MS-DOS) if this variable d23480 1 a23480 1 The 'GDBHISTFILE' environment variable is read after processing any d23482 1 a23482 1 commands passed using command line options (for example, '-ex'). d23484 1 a23484 1 If the FNAME argument is not given, or if the 'GDBHISTFILE' is the d23488 2 a23489 2 'set history save' 'set history save on' d23491 1 a23491 1 the 'set history filename' command. By default, this option is d23493 2 a23494 2 'set history filename' is set to the empty string then history saving is disabled, even when 'set history save' is 'on'. d23496 3 a23498 3 'set history save off' Don't record the command history into the file specified by 'set history filename' when GDB exits. d23500 2 a23501 2 'set history size SIZE' 'set history size unlimited' d23504 3 a23506 3 'GDBHISTSIZE', or to 256 if this variable is not set. Non-numeric values of 'GDBHISTSIZE' are ignored. If SIZE is 'unlimited' or if 'GDBHISTSIZE' is either a negative number or the empty string, then d23509 1 a23509 1 The 'GDBHISTSIZE' environment variable is read after processing any d23511 1 a23511 1 commands passed using command line options (for example, '-ex'). d23513 2 a23514 2 'set history remove-duplicates COUNT' 'set history remove-duplicates unlimited' d23519 1 a23519 1 list. If COUNT is 'unlimited' then this lookbehind is unbounded. d23526 1 a23526 1 History expansion assigns special meaning to the character '!'. d23529 3 a23531 3 Since '!' is also the logical not operator in C, history expansion is off by default. If you decide to enable history expansion with the 'set history expansion on' command, you may sometimes need to follow '!' d23534 1 a23534 1 not attempt substitution on the strings '!=' and '!(', even when history d23539 2 a23540 2 'set history expansion on' 'set history expansion' d23543 1 a23543 1 'set history expansion off' d23546 5 a23550 5 'show history' 'show history filename' 'show history save' 'show history size' 'show history expansion' d23552 1 a23552 1 'show history' by itself displays all four states. d23554 1 a23554 1 'show commands' d23557 1 a23557 1 'show commands N' d23560 1 a23560 1 'show commands +' d23572 1 a23572 1 see one more page of output, 'q' to discard the remaining output, or 'c' d23581 12 a23592 12 with the value of the 'TERM' environment variable and the 'stty rows' and 'stty cols' settings. If this is not correct, you can override it with the 'set height' and 'set width' commands: 'set height LPP' 'set height unlimited' 'show height' 'set width CPL' 'set width unlimited' 'show width' These 'set' commands specify a screen height of LPP lines and a screen width of CPL characters. The associated 'show' commands d23595 1 a23595 1 If you specify a height of either 'unlimited' or zero lines, GDB d23599 1 a23599 1 Likewise, you can specify 'set width unlimited' or 'set width 0' to d23602 2 a23603 2 'set pagination on' 'set pagination off' d23605 2 a23606 2 pagination off is the alternative to 'set height unlimited'. Note that running GDB with the '--batch' option (*note -batch: Mode d23609 1 a23609 1 'show pagination' d23623 1 a23623 1 'set style enabled 'on|off'' d23625 1 a23625 1 most hosts defaulting to 'on'. d23627 2 a23628 2 If the 'NO_COLOR' environment variable is set to a non-empty value, then GDB will change this to 'off' at startup. d23630 1 a23630 1 'show style enabled' d23633 1 a23633 1 'set style sources 'on|off'' d23635 2 a23636 2 code, such as the output of the 'list' command, is styled. The default is 'on'. Note that source styling only works if styling in d23645 1 a23645 1 'show style sources' d23648 1 a23648 1 'set style tui-current-position 'on|off'' d23651 1 a23651 1 is 'off'. *Note GDB Text User Interface: TUI. d23653 1 a23653 1 'show style tui-current-position' d23657 1 a23657 1 'set style disassembler enabled 'on|off'' d23659 1 a23659 1 disassembler output, such as the output of the 'disassemble' d23661 1 a23661 1 general is enabled (with 'set style enabled on'), and if a source d23680 1 a23680 1 unstyled disassembler output, even when this setting is 'on'. d23683 2 a23684 2 builtin disassembler library see *note 'maint show libopcodes-styling enabled': maint_libopcodes_styling. d23686 1 a23686 1 'show style disassembler enabled' d23689 1 a23689 1 Subcommands of 'set style' control specific forms of styling. These d23693 2 a23694 2 For example, the style of file names can be controlled using the 'set style filename' group of commands: d23696 13 a23708 13 'set style filename background COLOR' Set the background to COLOR. Valid colors are 'none' (meaning the terminal's default color), 'black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', and'white'. 'set style filename foreground COLOR' Set the foreground to COLOR. Valid colors are 'none' (meaning the terminal's default color), 'black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', and'white'. 'set style filename intensity VALUE' Set the intensity to VALUE. Valid intensities are 'normal' (the default), 'bold', and 'dim'. d23710 2 a23711 2 The 'show style' command and its subcommands are styling a style name in their output using its own style. So, use 'show style' to see the d23716 1 a23716 1 'filename' d23720 1 a23720 1 'function' d23722 1 a23722 1 'set style function' family of commands. By default, this style's d23727 1 a23727 1 (*note 'set style disassembler enabled': d23730 1 a23730 1 'variable' d23732 1 a23732 1 'set style variable' family of commands. By default, this style's d23735 3 a23737 3 'address' Control the styling of addresses. These are managed with the 'set style address' family of commands. By default, this style's d23742 1 a23742 1 'set style disassembler enabled': style_disassembler_enabled.). d23744 1 a23744 1 'version' d23747 2 a23748 2 version number is displayed in two places, the output of 'show version', and when GDB starts up. d23751 1 a23751 1 add the 'set style version' family of commands to the early d23754 3 a23756 3 'title' Control the styling of titles. These are managed with the 'set style title' family of commands. By default, this style's d23759 1 a23759 1 'apropos' and 'help' are using the title style for the command d23762 1 a23762 1 'highlight' d23764 1 a23764 1 'set style highlight' family of commands. By default, this style's d23767 1 a23767 1 For example, the command 'apropos -v REGEXP' uses the highlight d23770 1 a23770 1 'metadata' d23773 1 a23773 1 annotations include the 'repeats N times' annotation for suppressed d23775 2 a23776 2 '' and '' annotations for errors and '' annotations for optimized-out values in d23780 1 a23780 1 'tui-border' d23783 1 a23783 1 'set style'. This was done for compatibility reasons, as TUI d23787 1 a23787 1 'tui-active-border' d23791 1 a23791 1 'disassembler comment' d23793 1 a23793 1 are managed with the 'set style disassembler comment' family of d23795 2 a23796 2 builtin disassembler library (*note 'set style disassembler enabled': style_disassembler_enabled.). By default, this style's d23799 1 a23799 1 'disassembler immediate' d23801 1 a23801 1 These are managed with the 'set style disassembler immediate' d23803 2 a23804 2 operands that represent addresses, in that case the 'disassembler address' style is used. This style is only used when GDB is d23808 1 a23808 1 'disassembler address' d23810 1 a23810 1 This is an alias for the 'address' style. d23812 1 a23812 1 'disassembler symbol' d23814 1 a23814 1 This is an alias for the 'function' style. d23816 1 a23816 1 'disassembler mnemonic' d23818 3 a23820 3 output. These are managed with the 'set style disassembler mnemonic' family of commands. This style is also used for assembler directives, e.g. '.byte', '.word', etc. This style is d23824 1 a23824 1 'disassembler register' d23826 2 a23827 2 output. These are managed with the 'set style disassembler register' family of commands. This style is only used when GDB is d23838 3 a23840 3 the usual conventions: octal numbers begin with '0', decimal numbers end with '.', and hexadecimal numbers begin with '0x'. Numbers that neither begin with '0' or '0x', nor end with a '.' are, by default, entered in d23845 1 a23845 1 'set input-radix BASE' d23854 3 a23856 3 sets the input base to decimal. On the other hand, 'set input-radix 10' leaves the input radix unchanged, no matter what it was, since '10', being without any leading or trailing signs of its d23858 1 a23858 1 radix is 16, '10' is interpreted in hex, i.e. as 16 decimal, which d23861 1 a23861 1 'set output-radix BASE' d23866 1 a23866 1 'show input-radix' d23869 1 a23869 1 'show output-radix' d23872 2 a23873 2 'set radix [BASE]' 'show radix' d23875 1 a23875 1 output of numbers. 'set radix' sets the radix of input and output d23885 1 a23885 1 GDB can determine the "ABI" (Application Binary Interface) of your d23892 2 a23893 2 will autodetect the "OS ABI" (Operating System ABI) in use, but you can override its conclusion using the 'set osabi' command. One example d23900 1 a23900 1 "Newlib" OS ABI. This is useful for handling 'setjmp' and 'longjmp' when d23902 1 a23902 1 can be selected by 'set osabi Newlib'. d23904 1 a23904 1 'show osabi' d23907 1 a23907 1 'set osabi' d23910 1 a23910 1 'set osabi ABI' d23913 1 a23913 1 Generally, the way that an argument of type 'float' is passed to a d23915 4 a23918 4 prototyped (i.e. ANSI/ISO style) function, 'float' arguments are passed unchanged, according to the architecture's convention for 'float'. For unprototyped (i.e. K&R style) functions, 'float' arguments are first promoted to type 'double' and then passed. d23922 1 a23922 1 is not marked as prototyped, it consults 'set coerce-float-to-double'. d23924 3 a23926 3 'set coerce-float-to-double' 'set coerce-float-to-double on' Arguments of type 'float' will be promoted to 'double' when passed d23929 2 a23930 2 'set coerce-float-to-double off' Arguments of type 'float' will be passed directly to unprototyped d23933 2 a23934 2 'show coerce-float-to-double' Show the current setting of promoting 'float' to 'double'. d23941 2 a23942 2 use. Currently supported ABI's include "gnu-v2", for 'g++' versions before 3.0, "gnu-v3", for 'g++' versions 3.0 and later, and "hpaCC" for d23946 1 a23946 1 'show cp-abi' d23949 1 a23949 1 'set cp-abi' d23952 2 a23953 2 'set cp-abi ABI' 'set cp-abi auto' d23964 1 a23964 1 "auto-loading". While auto-loading is useful for automatically adapting d23974 1 a23974 1 '.gdbinit' file) requires accordingly configured 'auto-load safe-path' d23980 1 a23980 1 'set auto-load off' d23982 1 a23982 1 use this command with the '-iex' option (*note Option d23990 2 a23991 2 files, use the '-nx' option (*note Mode Options::), in addition to 'set auto-load no'. d23993 2 a23994 2 'show auto-load' Show whether auto-loading of each specific 'auto-load' file(s) is d24008 2 a24009 2 'info auto-load' Print whether each specific 'auto-load' file(s) have been d24067 2 a24068 2 * Init File in the Current Directory:: 'set/show/info auto-load local-gdbinit' * libthread_db.so.1 file:: 'set/show/info auto-load libthread-db' d24070 2 a24071 2 * Auto-loading safe path:: 'set/show/info auto-load safe-path' * Auto-loading verbose mode:: 'set/show debug auto-load' d24083 2 a24084 2 Note that loading of this local '.gdbinit' file also requires accordingly configured 'auto-load safe-path' (*note Auto-loading safe d24087 1 a24087 1 'set auto-load local-gdbinit [on|off]' d24091 1 a24091 1 'show auto-load local-gdbinit' d24095 1 a24095 1 'info auto-load local-gdbinit' d24110 2 a24111 2 The special 'libthread-db-search-path' entry '$sdir' is processed without checking this 'set auto-load libthread-db' switch as system d24113 2 a24114 2 'libthread-db-search-path' entries GDB checks first if 'set auto-load libthread-db' is enabled before trying to open such thread debugging d24118 1 a24118 1 configured 'auto-load safe-path' (*note Auto-loading safe path::). d24120 1 a24120 1 'set auto-load libthread-db [on|off]' d24124 1 a24124 1 'show auto-load libthread-db' d24128 1 a24128 1 'info auto-load libthread-db' d24141 1 a24141 1 automatically. GDB provides the 'set auto-load safe-path' setting to d24165 1 a24165 1 'set auto-load safe-path [DIRECTORIES]' d24170 3 a24172 3 'FNM_PATHNAME' for system function 'fnmatch' (*note fnmatch: (libc)Wildcard Matching.). If you omit DIRECTORIES, 'auto-load safe-path' will be reset to its default value as specified during d24175 3 a24177 3 The list of directories uses path separator (':' on GNU and Unix systems, ';' on MS-Windows and MS-DOS) to separate directories, similarly to the 'PATH' environment variable. d24179 1 a24179 1 'show auto-load safe-path' d24183 1 a24183 1 'add-auto-load-safe-path' d24189 2 a24190 2 This variable defaults to what '--with-auto-load-dir' has been configured to (*note with-auto-load-dir::). '$debugdir' and '$datadir' d24192 1 a24192 1 scripts-directory::. The default 'set auto-load safe-path' value can be d24194 1 a24194 1 '--with-auto-load-safe-path'. d24196 1 a24196 1 Setting this variable to '/' disables this security protection, d24198 1 a24198 1 '--without-auto-load-safe-path'. This variable is supposed to be set to d24208 1 a24208 1 '~/.gdbinit': 'add-auto-load-safe-path ~/src/gdb' d24211 1 a24211 1 displayed by by 'show auto-load safe-path' (such as '/usr:/bin' in d24214 1 a24214 1 'gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" ...' d24218 1 a24218 1 'gdb -iex "set auto-load safe-path /" ...' d24223 1 a24223 1 './configure --without-auto-load-safe-path' d24231 1 a24231 1 'gdb -iex "set auto-load no" ...' d24234 1 a24234 1 '~/.gdbinit': 'set auto-load no' d24273 1 a24273 1 'set debug auto-load [on|off]' d24276 1 a24276 1 'show debug auto-load' d24287 1 a24287 1 on a slow machine, you may want to use the 'set verbose' command. This d24291 1 a24291 1 Currently, the messages controlled by 'set verbose' are those which d24293 1 a24293 1 'symbol-file' in *note Commands to Specify Files: Files. d24295 1 a24295 1 'set verbose on' d24298 1 a24298 1 'set verbose off' d24301 2 a24302 2 'show verbose' Displays whether 'set verbose' is on or off. d24309 1 a24309 1 'set complaints LIMIT' d24315 1 a24315 1 'show complaints' d24329 1 a24329 1 'set confirm off' d24331 1 a24331 1 '--batch' option (*note -batch: Mode Options.) also automatically d24334 1 a24334 1 'set confirm on' d24337 1 a24337 1 'show confirm' d24341 2 a24342 2 find it useful to enable "command tracing". In this mode each command will be printed as it is executed, prefixed with one or more '+' d24345 1 a24345 1 'set trace-commands on' d24347 1 a24347 1 'set trace-commands off' d24349 1 a24349 1 'show trace-commands' d24363 1 a24363 1 'set exec-done-display' d24367 1 a24367 1 'show exec-done-display' d24371 1 a24371 1 'set debug aarch64' d24374 1 a24374 1 'show debug aarch64' d24378 1 a24378 1 'set debug arch' d24381 1 a24381 1 'show debug arch' d24384 1 a24384 1 'set debug aix-thread' d24387 1 a24387 1 'show debug aix-thread' d24390 2 a24391 2 'set debug amd-dbgapi-lib' 'show debug amd-dbgapi-lib' d24393 2 a24394 2 The 'set debug amd-dbgapi-lib log-level LEVEL' command can be used to enable diagnostic messages from the 'amd-dbgapi' library, where d24397 1 a24397 1 'off' d24400 1 a24400 1 'error' d24403 1 a24403 1 'warning' d24406 1 a24406 1 'info' d24409 1 a24409 1 'verbose' d24412 1 a24412 1 The 'show debug amd-dbgapi-lib log-level' command displays the d24415 2 a24416 2 'set debug amd-dbgapi' 'show debug amd-dbgapi' d24418 2 a24419 2 The 'set debug amd-dbgapi' command can be used to enable diagnostic messages in the 'amd-dbgapi' target. The 'show debug amd-dbgapi' d24423 1 a24423 1 'set debug check-physname' d24430 1 a24430 1 'show debug check-physname' d24433 1 a24433 1 'set debug coff-pe-read' d24436 1 a24436 1 'show debug coff-pe-read' d24440 1 a24440 1 'set debug dwarf-die' d24443 1 a24443 1 'show debug dwarf-die' d24446 1 a24446 1 'set debug dwarf-line' d24451 1 a24451 1 'show debug dwarf-line' d24454 1 a24454 1 'set debug dwarf-read' d24459 1 a24459 1 'show debug dwarf-read' d24462 1 a24462 1 'set debug displaced' d24465 1 a24465 1 'show debug displaced' d24469 1 a24469 1 'set debug event' d24472 1 a24472 1 'show debug event' d24475 1 a24475 1 'set debug event-loop' d24477 2 a24478 2 possible values are 'off', 'all' (shows all debugging info) and 'all-except-ui' (shows all debugging info except those about d24480 1 a24480 1 'show debug event-loop' d24484 1 a24484 1 'set debug expression' d24487 1 a24487 1 'show debug expression' d24491 1 a24491 1 'set debug fbsd-lwp' d24494 1 a24494 1 'show debug fbsd-lwp' d24497 1 a24497 1 'set debug fbsd-nat' d24499 1 a24499 1 'show debug fbsd-nat' d24502 1 a24502 1 'set debug fortran-array-slicing' d24506 1 a24506 1 'show debug fortran-array-slicing' d24510 1 a24510 1 'set debug frame' d24513 1 a24513 1 'show debug frame' d24516 1 a24516 1 'set debug gnu-nat' d24518 1 a24518 1 'show debug gnu-nat' d24521 1 a24521 1 'set debug infrun' d24523 1 a24523 1 inferior. The default is off. 'infrun.c' contains GDB's runtime d24526 1 a24526 1 'show debug infrun' d24529 1 a24529 1 'set debug infcall' d24532 1 a24532 1 'show debug infcall' d24535 1 a24535 1 'set debug jit' d24537 1 a24537 1 'show debug jit' d24540 1 a24540 1 'set debug linux-nat [on|off]' d24543 1 a24543 1 'show debug linux-nat' d24546 1 a24546 1 'set debug linux-namespaces' d24549 1 a24549 1 'show debug linux-namespaces' d24552 1 a24552 1 'set debug mach-o' d24555 1 a24555 1 'show debug mach-o' d24559 1 a24559 1 'set debug notification' d24562 1 a24562 1 'show debug notification' d24566 1 a24566 1 'set debug observer' d24569 1 a24569 1 'show debug observer' d24572 1 a24572 1 'set debug overload' d24576 1 a24576 1 'show debug overload' d24580 1 a24580 1 'set debug parser' d24582 1 a24582 1 Internally, this sets the 'yydebug' variable in the expression d24585 1 a24585 1 'show debug parser' d24588 1 a24588 1 'set debug remote' d24592 1 a24592 1 'show debug remote' d24595 1 a24595 1 'set debug remote-packet-max-chars' d24597 1 a24597 1 packet when 'set debug remote' is on. This is useful to prevent d24601 1 a24601 1 The default value is '512', which means GDB will truncate each d24604 1 a24604 1 Setting this option to 'unlimited' will disable truncation and will d24606 1 a24606 1 'show debug remote-packet-max-chars' d24609 1 a24609 1 'set debug separate-debug-file' d24612 1 a24612 1 'show debug separate-debug-file' d24615 1 a24615 1 'set debug serial' d24618 1 a24618 1 'show debug serial' d24621 1 a24621 1 'set debug solib' d24624 1 a24624 1 'show debug solib' d24627 1 a24627 1 'set debug symbol-lookup' d24632 1 a24632 1 'show debug symbol-lookup' d24635 1 a24635 1 'set debug symfile' d24638 1 a24638 1 'show debug symfile' d24641 1 a24641 1 'set debug symtab-create' d24646 1 a24646 1 'show debug symtab-create' d24649 1 a24649 1 'set debug target' d24654 1 a24654 1 'show debug target' d24657 1 a24657 1 'set debug timestamp' d24661 1 a24661 1 'show debug timestamp' d24665 1 a24665 1 'set debug varobj' d24668 1 a24668 1 'show debug varobj' d24672 1 a24672 1 'set debug xml' d24674 1 a24674 1 'show debug xml' d24677 1 a24677 1 'set debug breakpoints' d24680 1 a24680 1 'show debug breakpoints' d24690 2 a24691 2 'set interactive-mode' If 'on', forces GDB to assume that GDB was started in a terminal. d24694 2 a24695 2 'off', forces GDB to operate in the opposite mode, and it uses the default answers to all queries. If 'auto' (the default), GDB tries d24704 1 a24704 1 'show interactive-mode' d24708 4 a24711 4 'set suppress-cli-notifications' If 'on', command-line-interface (CLI) notifications that are printed by GDB are suppressed. If 'off', the notifications are printed as usual. The default value is 'off'. CLI notifications d24762 1 a24762 1 'show suppress-cli-notifications' d24785 1 a24785 1 'set script-extension off' d24788 1 a24788 1 'set script-extension soft' d24794 1 a24794 1 'set script-extension strict' d24799 2 a24800 2 'show script-extension' Display the current value of the 'script-extension' option. d24835 2 a24836 2 A "user-defined command" is a sequence of GDB commands to which you assign a new name as a command. This is done with the 'define' command. d24839 1 a24839 1 '$arg0...$argN'. A trivial example: d24849 1 a24849 1 This defines the command 'adder', which prints the sum of its three d24854 1 a24854 1 In addition, '$argc' may be used to find out how many arguments have d24866 1 a24866 1 Combining with the 'eval' command (*note eval::) makes it easier to d24879 1 a24879 1 'define COMMANDNAME' d24885 2 a24886 2 example, 'define target my-target' creates a user-defined 'target my-target' command. d24889 2 a24890 2 lines, which are given following the 'define' command. The end of these commands is marked by a line containing 'end'. d24892 1 a24892 1 'document COMMANDNAME' d24894 1 a24894 1 accessed by 'help'. The command COMMANDNAME must already be d24896 2 a24897 2 'define' reads the lines of the command definition, ending with 'end'. After the 'document' command is finished, 'help' on command d24900 2 a24901 2 You may use the 'document' command again to change the documentation of a command. Redefining the command with 'define' d24905 1 a24905 1 documentation will then be used by the 'help' and 'apropos' d24908 1 a24908 1 defining an alias as a set of nested 'with' commands (*note Command d24911 1 a24911 1 'define-prefix COMMANDNAME' d24914 1 a24914 1 the 'define' command. Note that 'define-prefix' can be used with a d24947 1 a24947 1 'dont-repeat' d24952 1 a24952 1 'help user-defined' d24957 2 a24958 2 'show user' 'show user COMMANDNAME' d24964 3 a24966 3 'show max-user-call-depth' 'set max-user-call-depth' The value of 'max-user-call-depth' controls how many recursion d24989 3 a24991 3 You may define "hooks", which are a special kind of user-defined command. Whenever you run the command 'foo', if the user-defined command 'hook-foo' exists, it is executed (with no arguments) before d24995 2 a24996 2 executed. Whenever you run the command 'foo', if the user-defined command 'hookpost-foo' exists, it is executed (with no arguments) after d25004 1 a25004 1 In addition, a pseudo-command, 'stop' exists. Defining ('hook-stop') d25009 1 a25009 1 For example, to ignore 'SIGALRM' signals while single-stepping, but d25024 1 a25024 1 As a further example, to hook at the beginning and end of the 'echo' d25043 3 a25045 3 e.g. 'backtrace' rather than 'bt'. You can hook a multi-word command by adding 'hook-' or 'hookpost-' to the last word of the command, e.g. 'define target hook-remote' to add a hook to 'target remote'. d25052 1 a25052 1 you get a warning from the 'define' command. d25061 1 a25061 1 commands. Comments (lines starting with '#') may also be included. An d25065 2 a25066 2 You can request the execution of a command file with the 'source' command. Note that the 'source' command is also used to evaluate d25068 1 a25068 1 configured using the 'script-extension' setting. *Note Extending GDB: d25071 1 a25071 1 'source [-s] [-v] FILENAME' d25083 1 a25083 1 the 'directory' command); except that '$cdir' is not searched because d25086 1 a25086 1 If '-s' is specified, then GDB searches for FILENAME on the search d25089 6 a25094 6 if FILENAME is 'mylib/myscript' and the search path contains '/home/user' then GDB will look for the script '/home/user/mylib/myscript'. The search is also done if FILENAME is an absolute path. For example, if FILENAME is '/tmp/myscript' and the search path contains '/home/user' then GDB will look for the script '/home/user/tmp/myscript'. For DOS-like systems, if FILENAME contains a d25096 2 a25097 2 if FILENAME is 'd:myscript' and the search path contains 'c:/tmp' then GDB will look for the script 'c:/tmp/myscript'. d25099 1 a25099 1 If '-v', for verbose mode, is given then GDB displays each command as d25117 2 a25118 2 example will execute commands from the file 'cmds'. All output and errors would be directed to 'log'. d25128 2 a25129 2 'if' 'else' d25131 1 a25131 1 executed commands. The 'if' command takes a single argument, which d25134 1 a25134 1 value is nonzero). There can then optionally be an 'else' line, d25137 1 a25137 1 containing 'end'. d25139 2 a25140 2 'while' This command allows to write loops. Its syntax is similar to 'if': d25143 2 a25144 2 line, terminated by an 'end'. These commands are called the "body" of the loop. The commands in the body of 'while' are executed d25147 3 a25149 3 'loop_break' This command exits the 'while' loop in whose body it is included. Execution of the script continues after that 'while's 'end' line. d25151 1 a25151 1 'loop_continue' d25153 2 a25154 2 commands in the 'while' loop in whose body it is included. Execution branches to the beginning of the 'while' loop, where it d25157 3 a25159 3 'end' Terminate the block of commands that are the body of 'if', 'else', or 'while' flow-control commands. d25173 1 a25173 1 'echo TEXT' d25175 1 a25175 1 escape sequences, such as '\n' to print a newline. *No newline is d25180 2 a25181 2 otherwise trimmed from all arguments. To print ' and foo = ', use the command 'echo \ and foo = \ '. d25196 1 a25196 1 'output EXPRESSION' d25198 1 a25198 1 newlines, no '$NN = '. The value is not entered in the value d25202 1 a25202 1 'output/FMT EXPRESSION' d25204 1 a25204 1 formats as for 'print'. *Note Output Formats: Output Formats, for d25207 1 a25207 1 'printf TEMPLATE, EXPRESSIONS...' d25217 2 a25218 2 As in 'C' 'printf', ordinary characters in TEMPLATE are printed verbatim, while "conversion specification" introduced by the '%' d25228 2 a25229 2 'printf' supports all the standard 'C' conversion specifications, including the flags and modifiers between the '%' character and the d25232 1 a25232 1 * The argument-ordering modifiers, such as '2$', are not d25235 1 a25235 1 * The modifier '*' is not supported for specifying precision or d25238 2 a25239 2 * The ''' flag (for separation of digits into groups according to 'LC_NUMERIC'') is not supported. d25241 1 a25241 1 * The type modifiers 'hh', 'j', 't', and 'z' are not supported. d25243 1 a25243 1 * The conversion letter 'n' (as in '%n') is not supported. d25245 1 a25245 1 * The conversion letters 'a' and 'A' are not supported. d25247 4 a25250 4 Note that the 'll' type modifier is supported only if the underlying 'C' implementation used to build GDB supports the 'long long int' type, and the 'L' type modifier is supported only if 'long double' type is available. d25252 2 a25253 2 As in 'C', 'printf' supports simple backslash-escape sequences, such as '\n', '\t', '\\', '\"', '\a', and '\f', that consist of d25257 2 a25258 2 Additionally, 'printf' supports conversion specifications for DFP ("Decimal Floating Point") types using the following length d25261 1 a25261 1 * 'H' for printing 'Decimal32' types. d25263 1 a25263 1 * 'D' for printing 'Decimal64' types. d25265 1 a25265 1 * 'DD' for printing 'Decimal128' types. d25267 1 a25267 1 If the underlying 'C' implementation used to build GDB has support d25271 1 a25271 1 In case there is no such 'C' support, no additional modifiers will d25278 1 a25278 1 Additionally, 'printf' supports a special '%V' output format. This d25280 1 a25280 1 GDB would produce with the standard 'print' command (*note d25288 2 a25289 2 It is possible to include print options with the '%V' format by placing them in '[...]' immediately after the '%V', like this: d25294 1 a25294 1 If you need to print a literal '[' directly after a '%V', then just d25300 1 a25300 1 'eval TEMPLATE, EXPRESSIONS...' d25310 1 a25310 1 When a new object file is read (for example, due to the 'file' command, d25312 1 a25312 1 the command file 'OBJFILE-gdb.gdb'. *Note Auto-loading extensions::. d25317 1 a25317 1 'set auto-load gdb-scripts [on|off]' d25321 1 a25321 1 'show auto-load gdb-scripts' d25325 1 a25325 1 'info auto-load gdb-scripts [REGEXP]' d25343 1 a25343 1 GDB itself uses aliases. For example 's' is an alias of the 'step' d25345 1 a25345 1 commands like 'set' and 'show'. d25348 2 a25349 2 multi-word commands. For example, GDB provides the 'tty' alias of the 'set inferior-tty' command. d25351 1 a25351 1 You can define a new alias with the 'alias' command. d25353 1 a25353 1 'alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS]' d25364 1 a25364 1 The '-a' option specifies that the new alias is an abbreviation of d25367 1 a25367 1 The '--' option specifies the end of options, and is useful when d25374 1 a25374 1 For example, the below defines an alias 'btfullall' that shows all d25383 2 a25384 2 'disas', the current shortest unambiguous abbreviation of the 'disassemble' command and you wanted an even shorter version named 'di'. d25391 1 a25391 1 the 'document' command. An alias automatically picks up the d25394 2 a25395 2 Here is an example where we make 'elms' an abbreviation of 'elements' in the 'set print elements' command. This is to show that you can make d25404 2 a25405 2 Note that if you are defining an alias of a 'set' command, and you want to have an alias for the corresponding 'show' command, then you d25414 2 a25415 2 for a more complex command. This creates alias 'spe' of the command 'set print elements'. d25439 1 a25439 1 For example, if you often use the command 'thread apply all' d25442 1 a25442 1 the '-ascending' and '-c' options by using: d25447 2 a25448 2 type the 'thread apply asc-all' followed by 'some arguments', GDB will execute 'thread apply all -ascending -c some arguments'. d25457 2 a25458 2 For example, you define a new alias 'bt_ALL' showing all possible information and another alias 'bt_SMALL' showing very limited d25465 1 a25465 1 (For more on using the 'alias' command, see *note Aliases::.) d25469 1 a25469 1 as argument. For example, the below defines 'faalocalsoftype' that d25479 2 a25480 2 'with' commands to have a particular combination of temporary settings. For example, the below defines the alias 'pp10' that pretty prints an d25484 7 a25490 7 This defines the alias 'pp10' as being a sequence of 3 commands. The first part 'with print pretty --' temporarily activates the setting 'set print pretty', then launches the command that follows the separator '--'. The command following the first part is also a 'with' command that temporarily changes the setting 'set print elements' to 10, then launches the command that follows the second separator '--'. The third part 'print' is the command the 'pp10' alias will launch, using the d25492 1 a25492 1 the user. For more information about the 'with' command usage, see d25496 1 a25496 1 the aliased command. When the alias is a set of nested commands, 'help' d25498 2 a25499 2 not particularly useful for an alias such as 'pp10'. For such an alias, it is useful to give a specific documentation using the 'document' d25516 1 a25516 1 configured using '--with-python'. d25519 1 a25519 1 'DATA-DIRECTORY/python', where DATA-DIRECTORY is the data directory as d25521 1 a25521 1 as the "python directory", is automatically added to the Python Search d25527 2 a25528 2 'DATA-DIRECTORY/python/gdb/command' or 'DATA-DIRECTORY/python/gdb/function' directories are automatically d25547 3 a25549 3 'python-interactive [COMMAND]' 'pi [COMMAND]' Without an argument, the 'python-interactive' command can be used d25551 1 a25551 1 'EOF' character (e.g., 'Ctrl-D' on an empty prompt). d25561 3 a25563 3 'python [COMMAND]' 'py [COMMAND]' The 'python' command can be used to evaluate Python code. d25565 1 a25565 1 If given an argument, the 'python' command will evaluate the d25571 3 a25573 3 If you do not provide an argument to 'python', it will act as a multi-line command, like 'define'. In this case, the Python script is made up of subsequent command lines, given after the 'python' d25575 1 a25575 1 'end'. For example: d25582 1 a25582 1 'set python print-stack' d25585 3 a25587 3 controlled using 'set python print-stack': if 'full', then full Python stack printing is enabled; if 'none', then Python stack and message printing is disabled; if 'message', the default, only the d25590 2 a25591 2 'set python ignore-environment [on|off]' By default this option is 'off', and, when GDB initializes its d25594 1 a25594 1 example 'PYTHONHOME', and 'PYTHONPATH'(1). d25596 1 a25596 1 If this option is set to 'on' before Python is initialized then d25602 1 a25602 1 This option is equivalent to passing '-E' to the real 'python' d25605 2 a25606 2 'set python dont-write-bytecode [auto|on|off]' When this option is 'off', then, once GDB has initialized the d25608 1 a25608 1 modules that it imports and write the byte code to disk in '.pyc' d25611 1 a25611 1 If this option is set to 'on' before Python is initialized then d25617 4 a25620 4 By default this option is set to 'auto'. In this mode, provided the 'python ignore-environment' setting is 'off', the environment variable 'PYTHONDONTWRITEBYTECODE' is examined to see if it should write out byte-code or not. 'PYTHONDONTWRITEBYTECODE' is d25626 1 a25626 1 This option is equivalent to passing '-B' to the real 'python' d25632 2 a25633 2 'source script-name' The script name must end with '.py' and GDB must be configured to d25635 1 a25635 1 'script-extension' setting. *Note Extending GDB: Extending GDB. d25639 9 a25647 9 'set debug py-breakpoint on|off' 'show debug py-breakpoint' When 'on', GDB prints debug messages related to the Python breakpoint API. This is 'off' by default. 'set debug py-unwind on|off' 'show debug py-unwind' When 'on', GDB prints debug messages related to the Python unwinder API. This is 'off' by default. d25651 1 a25651 1 (1) See the ENVIRONMENT VARIABLES section of 'man 1 python' for a d25661 1 a25661 1 command 'python help (gdb)'. d25666 1 a25666 1 'gdb.some_function ('foo', bar = 1, baz = 2)'. d25719 1 a25719 1 At startup, GDB overrides Python's 'sys.stdout' and 'sys.stderr' to d25722 1 a25722 1 (*note Screen Size::). In this situation, a Python 'KeyboardInterrupt' d25728 2 a25729 2 * GDB installs handlers for 'SIGCHLD' and 'SIGINT'. Python code must not override these, or even change the options using 'sigaction'. d25732 3 a25734 3 common for GUI toolkits to install a 'SIGCHLD' handler. When creating a new Python thread, you can use 'gdb.block_signals' or 'gdb.Thread' to handle this correctly; see *note Threading in d25737 1 a25737 1 * GDB takes care to mark its internal file descriptors as d25744 1 a25744 1 GDB introduces a new Python module, named 'gdb'. All methods and d25746 2 a25747 2 'import's the 'gdb' module for use in all scripts evaluated by the 'python' command. d25749 2 a25750 2 Some types of the 'gdb' module come with a textual representation (accessible through the 'repr' or 'str' functions). These are offered d25764 1 a25764 1 defaults to 'False'. d25768 3 a25770 3 If the TO_STRING parameter is 'True', then output will be collected by 'gdb.execute' and returned as a string. The default is 'False', in which case the return value is 'None'. If TO_STRING is 'True', d25778 1 a25778 1 and earlier, this function returned 'None' if there were no d25780 1 a25780 1 'gdb.breakpoints' returns an empty sequence in this case. d25784 2 a25785 2 'gdb.Breakpoint' objects matching function names defined by the REGEX pattern. If the MINSYMS keyword is 'True', all system d25790 1 a25790 1 integer value of THROTTLE, a 'RuntimeError' will be raised and no d25794 1 a25794 1 iterable that yields a collection of 'gdb.Symtab' objects and will d25796 1 a25796 1 'gdb.Symtab' objects. d25801 1 a25801 1 multi-part name. For example, 'print object' is a valid parameter d25805 1 a25805 1 'gdb.error' (*note Exception Handling::). Otherwise, the d25810 1 a25810 1 Sets the gdb parameter NAME to VALUE. As with 'gdb.parameter', the d25815 1 a25815 1 Create a Python context manager (for use with the Python 'with' d25819 1 a25819 1 This uses 'gdb.parameter' in its implementation, so it can throw d25835 1 a25835 1 doesn't exist in the value history, a 'gdb.error' exception will be d25839 1 a25839 1 of 'gdb.Value' (*note Values From Inferior::). d25842 1 a25842 1 Takes VALUE, an instance of 'gdb.Value' (*note Values From d25845 3 a25847 3 history number. If VALUE is not a 'gdb.Value', it is is converted using the 'gdb.Value' constructor. If VALUE can't be converted to a 'gdb.Value' then a 'TypeError' is raised. d25849 1 a25849 1 When a command implemented in Python prints a single 'gdb.Value' as d25860 1 a25860 1 include the '$' that is used to mark a convenience variable in an d25862 1 a25862 1 'None' is returned. d25867 4 a25870 4 include the '$' that is used to mark a convenience variable in an expression. If VALUE is 'None', then the convenience variable is removed. Otherwise, if VALUE is not a 'gdb.Value' (*note Values From Inferior::), it is is converted using the 'gdb.Value' d25876 1 a25876 1 'gdb.Value'. d25880 1 a25880 1 'False', meaning that the current frame or current static context d25889 1 a25889 1 Return the 'gdb.Symtab_and_line' object corresponding to the PC d25891 2 a25892 2 is passed as an argument, then the 'symtab' and 'line' attributes of the returned 'gdb.Symtab_and_line' object will be 'None' and 0 d25894 1 a25894 1 'gdb.current_progspace().find_pc_line(pc)' and is included for d25902 1 a25902 1 'gdb.STDOUT' d25905 1 a25905 1 'gdb.STDERR' d25908 1 a25908 1 'gdb.STDLOG' d25911 1 a25911 1 Writing to 'sys.stdout' or 'sys.stderr' will automatically call d25922 1 a25922 1 'gdb.STDOUT' d25925 1 a25925 1 'gdb.STDERR' d25928 1 a25928 1 'gdb.STDLOG' d25931 1 a25931 1 Flushing 'sys.stdout' or 'sys.stderr' will automatically call this d25937 1 a25937 1 'gdb.parameter('target-charset')' in that 'auto' is never returned. d25942 1 a25942 1 'gdb.parameter('target-wide-charset')' in that 'auto' is never d25948 1 a25948 1 'gdb.parameter('host-charset')' in that 'auto' is never returned. d25952 2 a25953 2 a string, or 'None'. This is identical to 'gdb.current_progspace().solib_name(address)' and is included for d25960 1 a25960 1 string holding any unparsed section of EXPRESSION (or 'None' if the d25962 2 a25963 2 either 'None' or another tuple that contains all the locations that match the expression represented as 'gdb.Symtab_and_line' objects d25965 1 a25965 1 is decoded the way that GDB's inbuilt 'break' or 'edit' commands do d25973 3 a25975 3 The parameter 'current_prompt' contains the current GDB prompt. This method must return a Python string, or 'None'. If a string is returned, the GDB prompt will be set to that string. If 'None' is d25986 1 a25986 1 from 'gdb.Architecture.name' (*note Architecture.name: d25990 1 a25990 1 Return a list of 'gdb.TargetConnection' objects, one for each d25995 1 a25995 1 Return a string in the format 'ADDR ', where ADDR is d26003 2 a26004 2 GDB looks back for a suitable symbol can be controlled with 'set print max-symbolic-offset' (*note Print Settings::). d26007 1 a26007 1 number information when 'set print symbol-filename on' (*note Print d26009 1 a26009 1 'ADDR at FILENAME:LINE-NUMBER'. d26030 1 a26030 1 'disassemble'. d26040 3 a26042 3 'gdb.parameter('language')', this function will never return 'auto'. If a 'gdb.Frame' object is available (*note Frames In Python::), the 'language' method might be preferable in some cases, d26057 1 a26057 1 be delivered to the GDB main thread. The 'block_signals' function d26066 2 a26067 2 This is a subclass of Python's 'threading.Thread' class. It overrides the 'start' method to call 'block_signals', making this d26075 1 a26075 1 if a Python command is running, 'KeyboardInterrupt' will be raised. d26077 1 a26077 1 Unlike most Python APIs in GDB, 'interrupt' is thread-safe. d26083 1 a26083 1 'post_event' will be run in the order in which they were posted; d26087 1 a26087 1 Unlike most Python APIs in GDB, 'post_event' is thread-safe. For d26118 1 a26118 1 When executing the 'python' command, Python exceptions uncaught within d26120 1 a26120 1 mechanism. If the command that called 'python' does not handle the d26122 1 a26122 1 will be printed depends on 'set python print-stack' (*note Python d26134 1 a26134 1 'gdb.error' d26136 1 a26136 1 derived from 'RuntimeError', for compatibility with earlier d26142 2 a26143 2 'gdb.MemoryError' This is a subclass of 'gdb.error' which is thrown when an operation d26146 3 a26148 3 'KeyboardInterrupt' User interrupt (via 'C-c' or by typing 'q' at a pagination prompt) is translated to a Python 'KeyboardInterrupt' exception. d26154 2 a26155 2 When implementing GDB commands in Python via 'gdb.Command', or functions via 'gdb.Function', it is useful to be able to throw an d26160 1 a26160 1 'gdb.GdbError' d26188 1 a26188 1 type 'gdb.Value'. GDB uses this object for its internal bookkeeping of d26193 1 a26193 1 example for an integer or floating-point value 'some_val': d26197 7 a26203 7 As result of this, 'bar' will also be a 'gdb.Value' object whose values are of the same type as those of 'some_val'. Valid Python operations can also be performed on 'gdb.Value' objects representing a 'struct' or 'class' object. For such cases, the overloaded operator (if present), is used to perform the operation. For example, if 'val1' and 'val2' are 'gdb.Value' objects representing instances of a 'class' which overloads the '+' operator, then one can use the '+' operator in their Python d26208 2 a26209 2 The result of the operation 'val3' is also a 'gdb.Value' object corresponding to the value returned by the overloaded '+' operator. In d26211 2 a26212 2 '+' (binary addition), '-' (binary subtraction), '*' (multiplication), '/', '%', '<<', '>>', '|', '&', '^'. d26215 3 a26217 3 accessed using the Python "dictionary syntax". For example, if 'some_val' is a 'gdb.Value' instance holding a structure, you can access its 'foo' element with: d26221 5 a26225 5 Again, 'bar' will also be a 'gdb.Value' object. Structure elements can also be accessed by using 'gdb.Field' objects as subscripts (*note Types In Python::, for more information on 'gdb.Field' objects). For example, if 'foo_field' is a 'gdb.Field' object corresponding to element 'foo' of the above structure, then 'bar' can also be accessed as d26230 1 a26230 1 If a 'gdb.Value' has array or pointer type, an integer index can be d26235 1 a26235 1 A 'gdb.Value' that represents a function can be executed via inferior d26240 1 a26240 1 For example, 'some_val' is a 'gdb.Value' instance representing a d26247 1 a26247 1 'gdb.Value'. d26253 2 a26254 2 'gdb.Value' object representing the address. Otherwise, this attribute holds 'None'. d26262 2 a26263 2 The type of this 'gdb.Value'. The value of this attribute is a 'gdb.Type' object (*note Types In Python::). d26266 1 a26266 1 The dynamic type of this 'gdb.Value'. This uses the object's d26277 1 a26277 1 just return the static type of the value as in 'ptype foo' (*note d26281 2 a26282 2 The value of this read-only boolean attribute is 'True' if this 'gdb.Value' has not yet been fetched from the inferior. GDB does d26287 2 a26288 2 The value of 'somevar' is not fetched at this time. It will be fetched when the value is needed, or when the 'fetch_lazy' method d26292 2 a26293 2 The value of this attribute is a 'bytes' object containing the bytes that make up this 'Value''s complete value in little endian d26298 2 a26299 2 buffer object (e.g. a 'bytes' object), the length of the new buffer must exactly match the length of this 'Value''s type. The bytes d26302 1 a26302 1 As with 'Value.assign' (*note Value.assign::), if this value cannot d26308 1 a26308 1 Many Python values can be converted directly to a 'gdb.Value' via d26316 1 a26316 1 A Python integer is converted to the C 'long' type for the d26320 1 a26320 1 A Python long is converted to the C 'long long' type for the d26324 1 a26324 1 A Python float is converted to the C 'double' type for the d26333 2 a26334 2 'gdb.Value' If 'val' is a 'gdb.Value', then a copy of the value is made. d26336 3 a26338 3 'gdb.LazyString' If 'val' is a 'gdb.LazyString' (*note Lazy Strings In Python::), then the lazy string's 'value' method is called, d26342 2 a26343 2 This second form of the 'gdb.Value' constructor returns a 'gdb.Value' of type TYPE where the value contents are taken from d26348 1 a26348 1 If TYPE is 'None' then this version of '__init__' behaves as though d26352 1 a26352 1 Assign RHS to this value, and return 'None'. If this value cannot d26357 1 a26357 1 Return a new instance of 'gdb.Value' that is the result of casting d26359 1 a26359 1 'gdb.Type' object. If the cast cannot be performed for some d26363 1 a26363 1 For pointer data types, this method returns a new 'gdb.Value' d26365 1 a26365 1 example, if 'foo' is a C pointer to an 'int', declared in your C d26370 1 a26370 1 then you can use the corresponding 'gdb.Value' to access what 'foo' d26375 2 a26376 2 The result 'bar' will be a 'gdb.Value' object holding the value pointed to by 'foo'. d26378 2 a26379 2 A similar function 'Value.referenced_value' exists which also returns 'gdb.Value' objects corresponding to the values pointed to d26381 5 a26385 5 values). However, the behavior of 'Value.dereference' differs from 'Value.referenced_value' by the fact that the behavior of 'Value.dereference' is identical to applying the C unary operator '*' on a given value. For example, consider a reference to a pointer 'ptrref', declared in your C++ program as d26393 6 a26398 6 Though 'ptrref' is a reference value, one can apply the method 'Value.dereference' to the 'gdb.Value' object corresponding to it and obtain a 'gdb.Value' which is identical to that corresponding to 'val'. However, if you apply the method 'Value.referenced_value', the result would be a 'gdb.Value' object identical to that corresponding to 'ptr'. d26404 6 a26409 6 The 'gdb.Value' object 'py_val' is identical to that corresponding to 'val', and 'py_ptr' is identical to that corresponding to 'ptr'. In general, 'Value.dereference' can be applied whenever the C unary operator '*' can be applied to the corresponding C value. For those cases where applying both 'Value.dereference' and 'Value.referenced_value' is allowed, the results obtained need not d26411 3 a26413 3 are however identical when applied on 'gdb.Value' objects corresponding to pointers ('gdb.Value' objects with type code 'TYPE_CODE_PTR') in a C/C++ program. d26417 1 a26417 1 'gdb.Value' object corresponding to the value referenced by the d26419 1 a26419 1 'Value.dereference' and 'Value.referenced_value' produce identical d26421 2 a26422 2 'Value.dereference' cannot get the values referenced by reference values. For example, consider a reference to an 'int', declared in d26428 4 a26431 4 then applying 'Value.dereference' to the 'gdb.Value' object corresponding to 'ref' will result in an error, while applying 'Value.referenced_value' will result in a 'gdb.Value' object identical to that corresponding to 'val'. d26437 2 a26438 2 The 'gdb.Value' object 'py_val' is identical to that corresponding to 'val'. d26441 1 a26441 1 Return a 'gdb.Value' object which is a reference to the value d26445 1 a26445 1 Return a 'gdb.Value' object which is a 'const' version of the value d26449 1 a26449 1 Like 'Value.cast', but works as if the C++ 'dynamic_cast' operator d26453 1 a26453 1 Like 'Value.cast', but works as if the C++ 'reinterpret_cast' d26457 1 a26457 1 Convert a 'gdb.Value' to a string, similarly to what the 'print' d26459 1 a26459 1 calling the 'str' function on the 'gdb.Value'. The representation d26467 3 a26469 3 'raw' 'True' if pretty-printers (*note Pretty Printing::) should not be used to format the value. 'False' if enabled d26471 1 a26471 1 'gdb.Value' should be used to format it. d26473 19 a26491 19 'pretty_arrays' 'True' if arrays should be pretty printed to be more convenient to read, 'False' if they shouldn't (see 'set print array' in *note Print Settings::). 'pretty_structs' 'True' if structs should be pretty printed to be more convenient to read, 'False' if they shouldn't (see 'set print pretty' in *note Print Settings::). 'array_indexes' 'True' if array indexes should be included in the string representation of arrays, 'False' if they shouldn't (see 'set print array-indexes' in *note Print Settings::). 'symbols' 'True' if the string representation of a pointer should include the corresponding symbol name (if one exists), 'False' if it shouldn't (see 'set print symbol' in *note Print d26494 13 a26506 13 'unions' 'True' if unions which are contained in other structures or unions should be expanded, 'False' if they shouldn't (see 'set print union' in *note Print Settings::). 'address' 'True' if the string representation of a pointer should include the address, 'False' if it shouldn't (see 'set print address' in *note Print Settings::). 'nibbles' 'True' if binary values should be displayed in groups of four bits, known as nibbles. 'False' if it shouldn't (*note set d26509 6 a26514 6 'deref_refs' 'True' if C++ references should be resolved to the value they refer to, 'False' (the default) if they shouldn't. Note that, unlike for the 'print' command, references are not automatically expanded when using the 'format_string' method or the 'str' function. There is no global 'print' setting to d26517 2 a26518 2 'actual_objects' 'True' if the representation of a pointer to an object should d26521 2 a26522 2 'False' if the _declared_ type should be used. (See 'set print object' in *note Print Settings::). d26524 9 a26532 9 'static_members' 'True' if static members should be included in the string representation of a C++ object, 'False' if they shouldn't (see 'set print static-members' in *note Print Settings::). 'max_characters' Number of string characters to print, '0' to follow 'max_elements', or 'UINT_MAX' to print an unlimited number of characters (see 'set print characters' in *note Print d26535 3 a26537 3 'max_elements' Number of array elements to print, or '0' to print an unlimited number of elements (see 'set print elements' in d26540 1 a26540 1 'max_depth' d26542 2 a26543 2 '-1' to print an unlimited number of elements (see 'set print max-depth' in *note Print Settings::). d26545 1 a26545 1 'repeat_threshold' d26547 2 a26548 2 elements, or '0' to represent all elements, even if repeated. (See 'set print repeats' in *note Print Settings::). d26550 1 a26550 1 'format' d26552 2 a26553 2 to use for the returned string. For instance, ''x'' is equivalent to using the GDB command 'print' with the '/x' d26556 2 a26557 2 'styling' 'True' if GDB should apply styling to the returned string. d26564 1 a26564 1 When 'False', which is the default, no output styling is d26567 2 a26568 2 'summary' 'True' when just a summary should be printed. In this mode, d26571 1 a26571 1 by 'set print frame-arguments scalars' (*note Print d26581 1 a26581 1 If this 'gdb.Value' represents a string, then this method converts d26593 2 a26594 2 pointer to or an array of characters or ints of type 'wchar_t', 'char16_t', or 'char32_t'. d26597 3 a26599 3 naming the encoding of the string in the 'gdb.Value', such as '"ascii"', '"iso-8859-6"' or '"utf-8"'. It accepts the same encodings as the corresponding argument to Python's 'string.decode' d26602 1 a26602 1 string, then either the 'target-charset' (*note Character Sets::) d26607 1 a26607 1 argument to Python's 'string.decode' method. d26613 2 a26614 2 If this 'gdb.Value' represents a string, then this method converts the contents to a 'gdb.LazyString' (*note Lazy Strings In d26618 2 a26619 2 naming the encoding of the 'gdb.LazyString'. Some examples are: 'ascii', 'iso-8859-6' or 'utf-8'. If the ENCODING argument is an d26635 2 a26636 2 If the 'gdb.Value' object is currently a lazy value ('gdb.Value.is_lazy' is 'True'), then the value is fetched from the d26640 1 a26640 1 If the 'gdb.Value' object is not a lazy value, this method has no d26651 1 a26651 1 GDB represents types from the inferior using the class 'gdb.Type'. d26653 1 a26653 1 The following type-related functions are available in the 'gdb' d26662 1 a26662 1 Ordinarily, this function will return an instance of 'gdb.Type'. d26666 1 a26666 1 Architectures In Python::, for the 'integer_type' method. d26669 3 a26671 3 of that type can be accessed using the Python "dictionary syntax". For example, if 'some_type' is a 'gdb.Type' instance holding a structure type, you can access its 'foo' field with: d26675 2 a26676 2 'bar' will be a 'gdb.Field' object; see below under the description of the 'Type.fields' method for a description of the 'gdb.Field' class. d26678 1 a26678 1 An instance of 'Type' has the following attributes: d26688 1 a26688 1 'TYPE_CODE_' constants defined below. d26692 1 a26692 1 situations, such as Rust 'enum' types or Ada variant records, the d26695 1 a26695 1 'gdb.lookup_type' may be dynamic; while the type of the variable's d26704 2 a26705 2 'gdb.lookup_symbol("array", ...).type' could yield a 'gdb.Type' which reports a size of 'None'. This is the dynamic type. d26707 1 a26707 1 However, examining 'gdb.parse_and_eval("array").type' would yield a d26711 1 a26711 1 The name of this type. If this type has no name, then 'None' is d26715 2 a26716 2 The size of this type, in target 'char' units. Usually, a target's 'char' type will be an 8-bit byte. However, on some unusual d26719 1 a26719 1 'None'. d26723 2 a26724 2 'struct', 'union', or 'enum' in C and C++; not all languages have this concept. If this type has no tag name, then 'None' is d26728 1 a26728 1 The 'gdb.Objfile' that this type was defined in, or 'None' if there d26732 2 a26733 2 This property is 'True' if the type is a scalar type, otherwise, this property is 'False'. Examples of non-scalar types include d26737 3 a26739 3 For scalar types (those for which 'Type.is_scalar' is 'True'), this property is 'True' if the type is signed, otherwise this property is 'False'. d26742 1 a26742 1 which 'Type.is_scalar' is 'False'), will raise a 'ValueError'. d26755 1 a26755 1 'Type.is_array_like', this is determined based on the originating d26765 1 a26765 1 * For structure and union types, this method returns the fields. d26767 1 a26767 1 * Enum types have one field per enum constant. d26769 1 a26769 1 * Function and method types have one field per parameter. The d26772 1 a26772 1 * Array types have one field representing the array's range. d26774 2 a26775 2 * If the type does not fit into one of these categories, a 'TypeError' is raised. d26777 1 a26777 1 Each field is a 'gdb.Field' object, with some pre-defined d26779 2 a26780 2 'bitpos' This attribute is not available for 'enum' or 'static' (as in d26784 1 a26784 1 this case, the value will be 'None'. Also, a dynamic type may d26788 2 a26789 2 'enumval' This attribute is only available for 'enum' fields, and its d26792 2 a26793 2 'name' The name of the field, or 'None' for anonymous fields. d26795 2 a26796 2 'artificial' This is 'True' if the field is artificial, usually meaning d26798 1 a26798 1 attribute is always provided, and is 'False' if the field is d26801 3 a26803 3 'is_base_class' This is 'True' if the field represents a base class of a C++ structure. This attribute is always provided, and is 'False' d26805 1 a26805 1 argument of 'fields', or if that type was not a C++ class. d26807 1 a26807 1 'bitsize' d26813 3 a26815 3 'type' The type of the field. This is usually an instance of 'Type', but it can be 'None' in some situations. d26817 1 a26817 1 'parent_type' d26819 1 a26819 1 'gdb.Type'. d26822 1 a26822 1 Return a new 'gdb.Type' object which represents an array of this d26830 1 a26830 1 Return a new 'gdb.Type' object which represents a vector of this d26837 1 a26837 1 The difference between an 'array' and a 'vector' is that arrays d26843 1 a26843 1 Return a new 'gdb.Type' object which represents a 'const'-qualified d26847 2 a26848 2 Return a new 'gdb.Type' object which represents a 'volatile'-qualified variant of this type. d26851 3 a26853 3 Return a new 'gdb.Type' object which represents an unqualified variant of this type. That is, the result is neither 'const' nor 'volatile'. d26856 1 a26856 1 Return a Python 'Tuple' object that contains two elements: the low d26858 1 a26858 1 type does not have a range, GDB will raise a 'gdb.error' exception d26862 1 a26862 1 Return a new 'gdb.Type' object which represents a reference to this d26866 1 a26866 1 Return a new 'gdb.Type' object which represents a pointer to this d26870 1 a26870 1 Return a new 'gdb.Type' that represents the real type, after d26874 1 a26874 1 Return a new 'gdb.Type' object which represents the target type of d26888 2 a26889 2 If this 'gdb.Type' is an instantiation of a template, this will return a new 'gdb.Value' or 'gdb.Type' which represents the value d26892 1 a26892 1 If this 'gdb.Type' is not a template type, or if the type has fewer d26900 1 a26900 1 Return 'gdb.Value' instance of this type whose value is optimized d26906 1 a26906 1 defined in the 'gdb' module: d26908 1 a26908 1 'gdb.TYPE_CODE_PTR' d26911 1 a26911 1 'gdb.TYPE_CODE_ARRAY' d26914 1 a26914 1 'gdb.TYPE_CODE_STRUCT' d26917 1 a26917 1 'gdb.TYPE_CODE_UNION' d26920 1 a26920 1 'gdb.TYPE_CODE_ENUM' d26923 1 a26923 1 'gdb.TYPE_CODE_FLAGS' d26926 1 a26926 1 'gdb.TYPE_CODE_FUNC' d26929 1 a26929 1 'gdb.TYPE_CODE_INT' d26932 1 a26932 1 'gdb.TYPE_CODE_FLT' d26935 2 a26936 2 'gdb.TYPE_CODE_VOID' The special type 'void'. d26938 1 a26938 1 'gdb.TYPE_CODE_SET' d26941 1 a26941 1 'gdb.TYPE_CODE_RANGE' d26944 1 a26944 1 'gdb.TYPE_CODE_STRING' d26949 1 a26949 1 'gdb.TYPE_CODE_BITSTRING' d26952 1 a26952 1 'gdb.TYPE_CODE_ERROR' d26955 1 a26955 1 'gdb.TYPE_CODE_METHOD' d26958 1 a26958 1 'gdb.TYPE_CODE_METHODPTR' d26961 1 a26961 1 'gdb.TYPE_CODE_MEMBERPTR' d26964 1 a26964 1 'gdb.TYPE_CODE_REF' d26967 1 a26967 1 'gdb.TYPE_CODE_RVALUE_REF' d26970 1 a26970 1 'gdb.TYPE_CODE_CHAR' d26973 1 a26973 1 'gdb.TYPE_CODE_BOOL' d26976 1 a26976 1 'gdb.TYPE_CODE_COMPLEX' d26979 1 a26979 1 'gdb.TYPE_CODE_TYPEDEF' d26982 1 a26982 1 'gdb.TYPE_CODE_NAMESPACE' d26985 1 a26985 1 'gdb.TYPE_CODE_DECFLOAT' d26988 1 a26988 1 'gdb.TYPE_CODE_INTERNAL_FUNCTION' d26992 1 a26992 1 'gdb.TYPE_CODE_XMETHOD' d26996 1 a26996 1 'gdb.TYPE_CODE_FIXED_POINT' d26999 1 a26999 1 'gdb.TYPE_CODE_NAMESPACE' d27002 1 a27002 1 Further support for types is provided in the 'gdb.types' Python d27019 1 a27019 1 To allow extensibility, GDB provides the 'gdb.ValuePrinter' base d27024 1 a27024 1 pretty-printer protocol, and 'gdb.ValuePrinter'-based printers are d27042 1 a27042 1 For efficiency, the 'children' method should lazily compute its d27045 1 a27045 1 '-var-list-children' (*note GDB/MI Variable Objects::) limit the d27048 2 a27049 2 Children may be hidden from display based on the value of 'set print max-depth' (*note Print Settings::). d27054 1 a27054 1 consumer as a 'displayhint' attribute of the variable being d27058 1 a27058 1 method must return a string or the special value 'None'. d27062 1 a27062 1 'array' d27064 2 a27065 2 CLI uses this to respect parameters such as 'set print elements' and 'set print array'. d27067 1 a27067 1 'map' d27072 1 a27072 1 'string' d27074 1 a27074 1 the printer's 'to_string' method returns a Python string of d27078 1 a27078 1 characters, respecting 'set print elements', and the like. d27080 1 a27080 1 The special value 'None' causes GDB to apply the default display d27089 2 a27090 2 When printing from the CLI, if the 'to_string' method exists, then GDB will prepend its result to the values returned by 'children'. d27094 2 a27095 2 the result of 'to_string' in a stack trace, omitting the result of 'children'. d27099 1 a27099 1 Otherwise, if this method returns an instance of 'gdb.Value', then d27104 1 a27104 1 to a 'gdb.Value', then GDB performs the conversion and prints the d27107 1 a27107 1 and strings are convertible to 'gdb.Value'; other types are not. d27109 1 a27109 1 Finally, if this method returns 'None' then no further operations d27116 1 a27116 1 objects derived from 'gdb.ValuePrinter'. d27119 1 a27119 1 'None' may be returned if the number can't readily be computed. d27123 1 a27123 1 objects derived from 'gdb.ValuePrinter'. d27130 1 a27130 1 pretty-printer for a 'gdb.Value': d27133 1 a27133 1 This function takes a 'gdb.Value' object as an argument. If a d27135 1 a27135 1 such printer exists, then this returns 'None'. d27138 2 a27139 2 (including temporarily applied settings, such as '/x') simply by calling 'Value.format_string' (*note Values From Inferior::). However, these d27144 2 a27145 2 given to 'Value.format_string', and whose values are the user's settings. During a 'print' or other operation, the values will d27164 1 a27164 1 The Python list 'gdb.pretty_printers' contains an array of d27167 1 a27167 1 'global' printers, they're available when debugging all inferiors. d27169 2 a27170 2 Each 'gdb.Progspace' contains a 'pretty_printers' attribute. Each 'gdb.Objfile' also contains a 'pretty_printers' attribute. d27172 1 a27172 1 Each function on these lists is passed a single 'gdb.Value' argument d27175 1 a27175 1 create a pretty-printer for the value, it should return 'None'. d27177 3 a27179 3 GDB first checks the 'pretty_printers' attribute of each 'gdb.Objfile' in the current program space and iteratively calls each enabled lookup routine in the list for that 'gdb.Objfile' until it d27184 1 a27184 1 'gdb.pretty_printers' list, again calling each enabled function until an d27198 1 a27198 1 For example, if 'print frame-arguments' is on, a backtrace can become d27201 1 a27201 1 Pretty-printers are enabled and disabled by attaching an 'enabled' d27203 1 a27203 1 attribute is present and its value is 'False', the printer is disabled, d27215 1 a27215 1 Here is an example showing how a 'std::string' printer might be d27217 1 a27217 1 must provide. Note that this example uses the 'gdb.ValuePrinter' base d27247 1 a27247 1 returns 'None'. d27258 1 a27258 1 An ideal auto-load file will consist solely of 'import's of your printer d27271 2 a27272 2 To continue the 'std::string' example (*note Pretty Printing API::), this code might appear in 'gdb.libstdcxx.v6': d27293 1 a27293 1 types, then its "subprinters" are the printers for the individual data d27296 1 a27296 1 The 'gdb.printing' module provides a formal way of solving these d27328 1 a27328 1 'gdb.printing' module. Instead a function is provided to build up the d27349 1 a27349 1 corresponding output of 'info pretty-printer': d27366 1 a27366 1 A "type printer" is just a Python object conforming to a certain d27372 2 a27373 2 otherwise. This is manipulated by the 'enable type-printer' and 'disable type-printer' commands. d27377 1 a27377 1 by the 'enable type-printer' and 'disable type-printer' commands. d27382 1 a27382 1 new object that supplies a 'recognize' method, as described below. d27384 1 a27384 1 When displaying a type, say via the 'ptype' command, GDB will compute d27390 2 a27391 2 GDB will call the 'instantiate' method of each enabled type printer. If this method returns 'None', then the result is ignored; otherwise, it d27396 1 a27396 1 stopping if the function returns a non-'None' value. The recognition d27400 1 a27400 1 If TYPE is not recognized, return 'None'. Otherwise, return a d27402 1 a27402 1 argument will be an instance of 'gdb.Type' (*note Types In d27425 3 a27427 3 'backtrace' (*note The backtrace command: backtrace-command.), '-stack-list-frames' (*note The -stack-list-frames command: -stack-list-frames.), '-stack-list-variables' (*note The d27429 2 a27430 2 '-stack-list-arguments' *note The -stack-list-arguments command: -stack-list-arguments.) and '-stack-list-locals' (*note The d27437 1 a27437 1 utilize tools such as the Python's 'itertools' module to work with and d27460 1 a27460 1 The Python dictionary 'gdb.frame_filters' contains key/object d27462 1 a27462 1 are called 'global' frame filters, and they are available when debugging d27464 1 a27464 1 directly. In addition to the 'global' dictionary, there are other d27467 3 a27469 3 dictionaries can be found are: 'gdb.Progspace' which contains a 'frame_filters' dictionary attribute, and each 'gdb.Objfile' object which also contains a 'frame_filters' dictionary attribute. d27472 2 a27473 2 filters, GDB combines the 'global', 'gdb.Progspace' and all 'gdb.Objfile' dictionaries currently loaded. All of the 'gdb.Objfile' d27476 2 a27477 2 'enabled' attribute is 'False'. This pruned list is then sorted according to the 'priority' attribute in each filter. d27480 1 a27480 1 iterator which wraps each frame in the call stack in a 'FrameDecorator' d27504 2 a27505 2 Note that the output from 'Filter3' is passed to the input of 'Filter2', and so on. d27507 2 a27508 2 This 'filter' method is passed a Python iterator. This iterator contains a sequence of frame decorators that wrap each 'gdb.Frame', d27511 1 a27511 1 receive an iterator entirely comprised of default 'FrameDecorator' d27528 1 a27528 1 The 'name' attribute must be Python string which contains the name d27535 1 a27535 1 The 'enabled' attribute must be Python boolean. This attribute d27537 2 a27538 2 considered when frame filters are executed. If 'enabled' is 'True', then the frame filter will be executed when any of the d27540 1 a27540 1 If 'enabled' is 'False', then the frame filter will not be d27544 1 a27544 1 The 'priority' attribute must be Python integer. This attribute d27546 2 a27547 2 There are no imposed limits on the range of 'priority' other than it must be a valid integer. The higher the 'priority' attribute, d27549 1 a27549 1 frame filters. Although 'priority' can be negative, it is d27566 1 a27566 1 of each 'gdb.Frame' in commands where frame filters are executed. This d27568 2 a27569 2 'gdb.Frame' with Python code contained within each API call. This separates the actual data contained in a 'gdb.Frame' from the decorated d27571 1 a27571 1 maintain integrity of the data contained in each 'gdb.Frame'. d27575 1 a27575 1 GDB already contains a frame decorator called 'FrameDecorator'. This d27577 1 a27577 1 of a 'gdb.Frame'. It is recommended that other frame decorators inherit d27580 2 a27581 2 'FrameDecorator' is defined in the Python module 'gdb.FrameDecorator', so your code can import it like: d27586 1 a27586 1 The 'elided' method groups frames together in a hierarchical d27593 1 a27593 1 The 'elided' function must return an iterable and this iterable d27596 3 a27598 3 return an empty iterable, or 'None'. Elided frames are indented from normal frames in a 'CLI' backtrace, or in the case of GDB/MI, are placed in the 'children' field of the eliding frame. d27610 1 a27610 1 'None'. d27612 1 a27612 1 If this function returns 'None', GDB will not print any data for d27620 1 a27620 1 size to describe the address of the frame, or 'None'. d27622 1 a27622 1 If this function returns a 'None', GDB will not print any data for d27631 1 a27631 1 the path to the object file backing the frame, or 'None'. d27633 1 a27633 1 If this function returns a 'None', GDB will not print any data for d27641 1 a27641 1 This method must return a Python integer type, or 'None'. d27643 1 a27643 1 If this function returns a 'None', GDB will not print any data for d27648 2 a27649 2 This method must return an iterable, or 'None'. Returning an empty iterable, or 'None' means frame arguments will not be printed for d27653 2 a27654 2 This object must implement a 'symbol' method which takes a single 'self' parameter and must return a 'gdb.Symbol' (*note Symbols In d27656 5 a27660 5 'value' method which takes a single 'self' parameter and must return a 'gdb.Value' (*note Values From Inferior::), a Python value, or 'None'. If the 'value' method returns 'None', and the 'argument' method returns a 'gdb.Symbol', GDB will look-up and print the value of the 'gdb.Symbol' automatically. d27700 2 a27701 2 This method must return an iterable or 'None'. Returning an empty iterable, or 'None' means frame local arguments will not be printed d27706 1 a27706 1 described in the 'frame_args' function, (*note The frame filter d27733 1 a27733 1 This method must return the underlying 'gdb.Frame' that this frame d27784 2 a27785 2 the comments the filter assigns the following attributes: 'name', 'priority' and whether the filter should be enabled with the 'enabled' d27791 2 a27792 2 'gdb.frame_filters'. As noted earlier, 'gdb.frame_filters' is a dictionary that is initialized in the 'gdb' module when GDB starts. d27795 1 a27795 1 registered either in the 'objfile' or 'progspace' dictionaries as they d27809 1 a27809 1 the same as frame filter's 'name' attribute. When a user manages frame d27811 1 a27811 1 are those contained in the 'name' attribute. d27813 2 a27814 2 The final step of this example is the implementation of the 'filter' method. As shown in the example comments, we define the 'filter' method d27818 1 a27818 1 valid operation for frame filters that have the 'enabled' attribute set, d27828 1 a27828 1 decorator to all frames with the Python 'itertools imap' method, the d27870 2 a27871 2 that the 'filter' method applies a frame decorator object called 'InlinedFrameDecorator' to each element in the iterator. The 'imap' d27892 2 a27893 2 This frame decorator only defines and overrides the 'function' method. It lets the supplied 'FrameDecorator', which is shipped with d27907 1 a27907 1 'function' callback. Using a strategy like this is a way to defer d27915 1 a27915 1 want to hierarchically represent frames, the 'elided' frame decorator d27918 1 a27918 1 This example approaches the issue with the 'elided' method. This d27939 1 a27939 1 ('frame_iter') with a custom iterator called 'ElidingInlineIterator'. d27966 2 a27967 2 'next' function is called (when GDB prints each frame), the iterator checks if this frame decorator, 'frame', is wrapping an inlined frame. d27970 1 a27970 1 contained within the next oldest frame, 'eliding_frame', which it d27972 1 a27972 1 'ElidingFrameDecorator', which contains both the elided frame, and the d27986 1 a27986 1 frame in the 'elided' method. As before it lets 'FrameDecorator' do the d27994 3 a27996 3 In that output, 'max' which has been inlined into 'main' is printed hierarchically. Another approach would be to combine the 'function' method, and the 'elided' method to both print a marker in the inlined d28021 4 a28024 4 two attributes, 'name' and 'enabled', with obvious meanings, and a single method '__call__', which examines a given frame and returns an object (an instance of 'gdb.UnwindInfo class)' describing it. If an unwinder does not recognize a frame, it should return 'None'. The code d28038 1 a28038 1 An object passed to an unwinder (a 'gdb.PendingFrame' instance) provides d28043 1 a28043 1 'gdb.Value' object. For a description of the acceptable values of d28048 1 a28048 1 Note that this method will always return a 'gdb.Value' for a valid d28052 1 a28052 1 'gdb.Value' returned from this method will be lazy; that is, its d28057 1 a28057 1 The type of the returned 'gdb.Value' depends on the register and d28059 1 a28059 1 type, like 'long long'; but many other types are possible, such as d28062 1 a28062 1 It also provides a factory method to create a 'gdb.UnwindInfo' d28066 1 a28066 1 Returns a new 'gdb.UnwindInfo' instance identified by given d28071 1 a28071 1 'sp, pc' d28082 1 a28082 1 'sp, pc, special' d28090 1 a28090 1 'sp' d28096 1 a28096 1 Each attribute value should either be an instance of 'gdb.Value' or d28099 1 a28099 1 A helper class is provided in the 'gdb.unwinder' module that can be d28103 2 a28104 2 Return the 'gdb.Architecture' (*note Architectures In Python::) for this 'gdb.PendingFrame'. This represents the architecture of the d28112 1 a28112 1 Returns the function name of this pending frame, or 'None' if it d28116 1 a28116 1 Returns true if the 'gdb.PendingFrame' object is valid, false if d28120 1 a28120 1 All 'gdb.PendingFrame' methods, except this one, will raise an d28131 1 a28131 1 raise a 'RuntimeError' exception. d28147 2 a28148 2 Use 'PendingFrame.create_unwind_info' method described above to create a 'gdb.UnwindInfo' instance. Use the following method to specify caller d28155 1 a28155 1 'gdb.Value' object). d28157 1 a28157 1 The 'gdb.unwinder' Module d28160 1 a28160 1 GDB comes with a 'gdb.unwinder' module which contains the following d28164 1 a28164 1 The 'Unwinder' class is a base class from which user created d28167 1 a28167 1 the required 'name' and 'enabled' attributes. d28178 2 a28179 2 A modifiable attribute containing a boolean; when 'True', the unwinder is enabled, and will be used by GDB. When 'False', d28184 1 a28184 1 calling 'gdb.PendingFrame.create_unwind_info'. It is not required d28189 1 a28189 1 'gdb.unwinder.FrameId' has the following method: d28191 1 a28191 2 -- Function: gdb.unwinder.FrameId.__init__(sp, pc, special = 'None') d28193 1 a28193 1 'gdb.Value' object, or an integer. d28196 1 a28196 1 'gdb.Value' object, or an integer. d28198 1 a28198 1 'gdb.unwinder.FrameId' has the following read-only attributes: d28207 1 a28207 1 The SPECIAL value passed to the constructor, or 'None' if no d28216 1 a28216 1 The 'gdb.unwinders' module provides the function to register an d28223 1 a28223 1 program space (*note Progspaces In Python::), or 'None', in which d28228 1 a28228 1 exception unless REPLACE is 'True', in which case the old unwinder d28272 1 a28272 1 'info unwinder [ LOCUS [ NAME-REGEXP ] ]' d28277 1 a28277 1 The LOCUS argument should be either 'global', 'progspace', or the d28284 2 a28285 2 'disable unwinder [ LOCUS [ NAME-REGEXP ] ]' The LOCUS and NAME-REGEXP are interpreted as in 'info unwinder' d28287 4 a28290 4 matching unwinders are disabled. The 'enabled' field of each matching unwinder is set to 'False'. 'enable unwinder [ LOCUS [ NAME-REGEXP ] ]' The LOCUS and NAME-REGEXP are interpreted as in 'info unwinder' d28292 2 a28293 2 matching unwinders are enabled. The 'enabled' field of each matching unwinder is set to 'True'. d28301 1 a28301 1 "Xmethods" are additional methods or replacements for existing methods d28315 1 a28315 1 "xmethod matcher" and an "xmethod worker". To implement an xmethod, one d28318 1 a28318 1 instance of the method). Internally, GDB invokes the 'match' method of d28320 1 a28320 1 'match' method returns a list of matching _worker_ objects. Each worker d28322 1 a28322 1 They implement a 'get_arg_types' method which returns a sequence of d28334 1 a28334 1 '__call__' method of the worker object. d28357 2 a28358 2 'XMethodMatcher' defined in the module 'gdb.xmethod', or an object with similar interface and attributes. An instance of 'XMethodMatcher' has d28370 2 a28371 2 list is an instance of the class 'XMethod' defined in the module 'gdb.xmethod', or any object with the following attributes: d28373 1 a28373 1 'name' d28377 1 a28377 1 'enabled' d28381 1 a28381 1 The class 'XMethod' is a convenience class with same attributes as d28387 1 a28387 1 The 'XMethodMatcher' class has the following methods: d28391 1 a28391 1 'methods' attribute is initialized to 'None'. d28397 2 a28398 2 'gdb.Type' object, and METHOD_NAME is a string value. If the matcher manages named methods as listed in its 'methods' attribute, d28400 1 a28400 1 'methods' list are enabled should be returned. d28403 1 a28403 1 'XMethodWorker' defined in the module 'gdb.xmethod', or support the d28407 1 a28407 1 This method returns a sequence of 'gdb.Type' objects corresponding d28409 2 a28410 2 sequence or 'None' if the xmethod does not take any arguments. If the xmethod takes a single argument, then a single 'gdb.Type' d28414 1 a28414 1 This method returns a 'gdb.Type' object representing the type of d28416 1 a28416 1 tuple of arguments that would be passed to the '__call__' method of d28423 1 a28423 1 the 'this' pointer value. d28426 1 a28426 1 using the following function defined in the module 'gdb.xmethod': d28429 5 a28433 5 The 'matcher' is registered with 'locus', replacing an existing matcher with the same name as 'matcher' if 'replace' is 'True'. 'locus' can be a 'gdb.Objfile' object (*note Objfiles In Python::), or a 'gdb.Progspace' object (*note Progspaces In Python::), or 'None'. If it is 'None', then 'matcher' is registered globally. d28463 4 a28466 4 Let us define two xmethods for the class 'MyClass', one replacing the method 'geta', and another adding an overloaded flavor of 'operator+' which takes a 'MyClass' argument (the C++ code above already has an overloaded 'operator+' which takes an 'int' argument). The xmethod d28505 5 a28509 5 Notice that the 'match' method of 'MyClassMatcher' returns a worker object of type 'MyClassWorker_geta' for the 'geta' method, and a worker object of type 'MyClassWorker_plus' for the 'operator+' method. This is done indirectly via helper classes derived from 'gdb.xmethod.XMethod'. One does not need to use the 'methods' attribute in a matcher as it is d28511 1 a28511 1 good practice to list the xmethods in the 'methods' attribute of the d28513 2 a28514 2 xmethods via the 'enable/disable' commands. Notice also that a worker object is returned only if the corresponding entry in the 'methods' d28547 1 a28547 1 If an object 'obj' of type 'MyClass' is initialized in C++ code as d28553 2 a28554 2 workers into GDB, invoking the method 'geta' or using the operator '+' on 'obj' will invoke the xmethods defined above: d28582 1 a28582 1 replacement for the 'footprint' method. The full code listing of the d28611 1 a28611 1 Notice that, in this example, we have not used the 'methods' d28625 1 a28625 1 of the 'gdb.Inferior' class. d28627 1 a28627 1 The following inferior-related functions are available in the 'gdb' d28636 1 a28636 1 A 'gdb.Inferior' object has the following attributes: d28644 2 a28645 2 The 'gdb.TargetConnection' for this inferior (*note Connections In Python::), or 'None' if this inferior has no connection. d28651 2 a28652 2 'gdb.Inferior.connection.num' in the case where 'gdb.Inferior.connection' is not 'None'. d28665 1 a28665 1 'None'. d28672 1 a28672 1 to the 'set args' and 'show args' commands. *Note Arguments::. d28676 1 a28676 1 If there are no arguments, the value is 'None'. d28683 1 a28683 1 A 'gdb.Inferior' object has the following methods: d28686 3 a28688 3 Returns 'True' if the 'gdb.Inferior' object is valid, 'False' if not. A 'gdb.Inferior' object will become invalid if the inferior no longer exists within GDB. All other 'gdb.Inferior' methods will d28698 1 a28698 1 Return the 'gdb.Architecture' (*note Architectures In Python::) for d28706 1 a28706 1 ADDRESS. Returns a 'memoryview' object, which behaves much like an d28708 1 a28708 1 'Inferior.write_memory' function. d28714 1 a28714 1 from 'Inferior.read_memory'. If given, LENGTH determines the d28722 2 a28723 2 'gdb.read_memory'. Returns a Python 'Long' containing the address where the pattern was found, or 'None' if the pattern could not be d28728 1 a28728 1 specific data structure such as 'pthread_t' for pthreads library d28731 2 a28732 2 The function 'Inferior.thread_from_thread_handle' provides the same functionality, but use of 'Inferior.thread_from_thread_handle' is d28751 1 a28751 1 One may add arbitrary attributes to 'gdb.Inferior' objects in the d28797 1 a28797 1 An "event" is just an object that describes some state change. The d28802 2 a28803 2 handler with an "event registry". An event registry is an object in the 'gdb.events' module which dispatches particular events. A registry d28825 4 a28828 4 In the above example we connect our handler 'exit_handler' to the registry 'events.exited'. Once connected, 'exit_handler' gets called when the inferior exits. The argument "event" in this example is of type 'gdb.ExitedEvent'. As you can see in the example the 'ExitedEvent' d28833 1 a28833 1 'gdb.ThreadEvent'. This event is a base class and is never emitted d28836 1 a28836 1 'gdb.BreakpointEvent' and 'gdb.ContinueEvent'. 'gdb.ThreadEvent' holds d28842 1 a28842 1 to 'None'. d28847 2 a28848 2 'events.cont' Emits 'gdb.ContinueEvent', which extends 'gdb.ThreadEvent'. This d28850 1 a28850 1 For inherited attribute refer to 'gdb.ThreadEvent' above. d28852 3 a28854 3 'events.exited' Emits 'events.ExitedEvent', which indicates that the inferior has exited. 'events.ExitedEvent' has two attributes: d28863 1 a28863 1 A reference to the inferior which triggered the 'exited' d28866 2 a28867 2 'events.stop' Emits 'gdb.StopEvent', which extends 'gdb.ThreadEvent'. d28870 3 a28872 3 this registry extend 'gdb.StopEvent'. As a child of 'gdb.ThreadEvent', 'gdb.StopEvent' will indicate the stopped thread when GDB is running in non-stop mode. Refer to 'gdb.ThreadEvent' d28875 1 a28875 1 'gdb.StopEvent' has the following additional attributes: d28887 1 a28887 1 When a 'StopEvent' results from a 'finish' command, it will d28889 3 a28891 3 available. This will be an entry named 'return-value' in the 'details' dictionary. The value of this entry will be a 'gdb.Value' object. d28893 1 a28893 1 Emits 'gdb.SignalEvent', which extends 'gdb.StopEvent'. d28896 1 a28896 1 received a signal. 'gdb.SignalEvent' has the following attributes: d28901 1 a28901 1 command 'info signals' in the GDB command prompt. d28903 1 a28903 1 Also emits 'gdb.BreakpointEvent', which extends 'gdb.StopEvent'. d28905 1 a28905 1 'gdb.BreakpointEvent' event indicates that one or more breakpoints d28910 2 a28911 2 'gdb.Breakpoint') that were hit. *Note Breakpoints In Python::, for details of the 'gdb.Breakpoint' object. d28916 1 a28916 1 deprecated in favor of the 'gdb.BreakpointEvent.breakpoints' d28919 3 a28921 3 'events.new_objfile' Emits 'gdb.NewObjFileEvent' which indicates that a new object file has been loaded by GDB. 'gdb.NewObjFileEvent' has one attribute: d28924 1 a28924 1 A reference to the object file ('gdb.Objfile') which has been d28926 1 a28926 1 'gdb.Objfile' object. d28928 2 a28929 2 'events.free_objfile' Emits 'gdb.FreeObjFileEvent' which indicates that an object file is d28931 1 a28931 1 the inferior calls 'dlclose'. 'gdb.FreeObjFileEvent' has one d28935 1 a28935 1 A reference to the object file ('gdb.Objfile') which will be d28937 1 a28937 1 'gdb.Objfile' object. d28939 2 a28940 2 'events.clear_objfiles' Emits 'gdb.ClearObjFilesEvent' which indicates that the list of d28942 1 a28942 1 'gdb.ClearObjFilesEvent' has one attribute: d28945 1 a28945 1 A reference to the program space ('gdb.Progspace') whose d28948 1 a28948 1 'events.inferior_call' d28951 2 a28952 2 type 'gdb.InferiorCallPreEvent', and after an inferior call, this emits an event of type 'gdb.InferiorCallPostEvent'. d28954 1 a28954 1 'gdb.InferiorCallPreEvent' d28964 1 a28964 1 'gdb.InferiorCallPostEvent' d28974 2 a28975 2 'events.memory_changed' Emits 'gdb.MemoryChangedEvent' which indicates that the memory of d28977 1 a28977 1 command like 'set *addr = value'. The event has the following d28986 2 a28987 2 'events.register_changed' Emits 'gdb.RegisterChangedEvent' which indicates that a register in d28996 1 a28996 1 'events.breakpoint_created' d28998 1 a28998 1 argument that is passed is the new 'gdb.Breakpoint' object. d29000 1 a29000 1 'events.breakpoint_modified' d29002 1 a29002 1 The argument that is passed is the new 'gdb.Breakpoint' object. d29004 1 a29004 1 'events.breakpoint_deleted' d29006 3 a29008 3 that is passed is the 'gdb.Breakpoint' object. When this event is emitted, the 'gdb.Breakpoint' object will already be in its invalid state; that is, the 'is_valid' method will return 'False'. d29010 1 a29010 1 'events.before_prompt' d29014 1 a29014 1 'events.new_inferior' d29019 1 a29019 1 The event is of type 'gdb.NewInferiorEvent'. This has a single d29023 1 a29023 1 The new inferior, a 'gdb.Inferior' object. d29025 1 a29025 1 'events.inferior_deleted' d29028 1 a29028 1 itself is removed, say via 'remove-inferiors'. d29030 1 a29030 1 The event is of type 'gdb.InferiorDeletedEvent'. This has a single d29034 1 a29034 1 The inferior that is being removed, a 'gdb.Inferior' object. d29036 1 a29036 1 'events.new_thread' d29038 1 a29038 1 type 'gdb.NewThreadEvent', which extends 'gdb.ThreadEvent'. This d29044 1 a29044 1 'events.thread_exited' d29046 1 a29046 1 of type 'gdb.ThreadExitedEvent' which extends 'gdb.ThreadEvent'. d29052 1 a29052 1 'events.gdb_exiting' d29055 1 a29055 1 signal. The event is of type 'gdb.GdbExitingEvent', which has a d29061 1 a29061 1 'events.connection_removed' d29063 1 a29063 1 Python::). The event is of type 'gdb.ConnectionEvent'. This has a d29067 1 a29067 1 The 'gdb.TargetConnection' that is being removed. d29069 3 a29071 3 'events.executable_changed' Emits 'gdb.ExecutableChangedEvent' which indicates that the 'gdb.Progspace.executable_filename' has changed. d29074 1 a29074 1 'gdb.Progspace.executable_filename ' has changed to name a d29076 1 a29076 1 'gdb.Progspace.executable_filename' has changed on disk, and GDB d29080 1 a29080 1 The 'gdb.Progspace' in which the current executable has d29082 1 a29082 1 visible in 'gdb.Progspace.executable_filename' (*note d29085 2 a29086 2 This attribute will be 'True' if the value of 'gdb.Progspace.executable_filename' didn't change, but the d29089 2 a29090 2 When this attribute is 'False', the value in 'gdb.Progspace.executable_filename' was changed to name a d29095 2 a29096 2 'gdb.Progspace.executable_filename' and 'gdb.Progspace.filename' respectively. When using the 'file' command, GDB updates both of d29101 1 a29101 1 'events.new_progspace' d29104 1 a29104 1 'gdb.NewProgspaceEvent', and has a single read-only attribute: d29107 1 a29107 1 The 'gdb.Progspace' that was added to GDB. d29109 1 a29109 1 No 'NewProgspaceEvent' is emitted for the very first program space, d29113 1 a29113 1 'events.free_progspace' d29116 1 a29116 1 of the 'remove-inferiors' command (*note 'remove-inferiors': d29118 1 a29118 1 'gdb.FreeProgspaceEvent', and has a single read-only attribute: d29121 1 a29121 1 The 'gdb.Progspace' that is about to be removed from GDB. d29130 1 a29130 1 threads controlled by GDB, via objects of the 'gdb.InferiorThread' d29133 1 a29133 1 The following thread-related functions are available in the 'gdb' d29138 1 a29138 1 If there is no selected thread, this will return 'None'. d29141 1 a29141 1 'Inferior.threads()' method. *Note Inferiors In Python::. d29143 1 a29143 1 A 'gdb.InferiorThread' object has the following attributes: d29146 2 a29147 2 The name of the thread. If the user specified a name using 'thread name', then this returns that name. Otherwise, if an OS-supplied d29149 1 a29149 1 'None'. d29152 1 a29152 1 object, which sets the new name, or 'None', which removes any d29173 3 a29175 3 'InferiorThread.ptid'. This is the string that GDB uses in the 'Target Id' column in the 'info threads' output (*note 'info threads': info_threads.). d29179 1 a29179 1 as a 'gdb.Inferior' object. This attribute is not writable. d29185 1 a29185 1 'None'. d29188 3 a29190 3 of exiting will return the string 'Exiting'. For remote targets the 'details' string will be obtained with the 'qThreadExtraInfo' remote packet, if the target supports it (*note 'qThreadExtraInfo': d29193 2 a29194 2 GDB displays the 'details' string as part of the 'Target Id' column, in the 'info threads' output (*note 'info threads': d29197 1 a29197 1 A 'gdb.InferiorThread' object has the following methods: d29200 2 a29201 2 Returns 'True' if the 'gdb.InferiorThread' object is valid, 'False' if not. A 'gdb.InferiorThread' object will become invalid if the d29203 1 a29203 1 All other 'gdb.InferiorThread' methods will throw an exception if d29220 5 a29224 5 Return the thread object's handle, represented as a Python 'bytes' object. A 'gdb.Value' representation of the handle may be constructed via 'gdb.Value(bufobj, type)' where BUFOBJ is the Python 'bytes' representation of the handle and TYPE is a 'gdb.Type' for the handle type. d29226 1 a29226 1 One may add arbitrary attributes to 'gdb.InferiorThread' objects in d29265 1 a29265 1 Replay::) are available in the 'gdb' module: d29271 1 a29271 1 'gdb.Record' object on success. Throw an exception on failure. d29275 2 a29276 2 * '"full"' * '"btrace"': Possible values for FORMAT: '"pt"', '"bts"' or d29280 2 a29281 2 Access a currently running recording. Return a 'gdb.Record' object on success. Return 'None' if no recording is currently active. d29288 1 a29288 1 A 'gdb.Record' object has the following attributes: d29291 2 a29292 2 A string with the current recording method, e.g. 'full' or 'btrace'. d29295 2 a29296 2 A string with the current recording format, e.g. 'bt', 'pts' or 'None'. d29308 1 a29308 1 is no replay active, this will be 'None'. d29316 1 a29316 1 A 'gdb.Record' object has the following methods: d29321 1 a29321 1 The common 'gdb.Instruction' class that recording method specific d29328 1 a29328 1 A 'memoryview' object holding the raw instruction data. d29336 1 a29336 1 Additionally 'gdb.RecordInstruction' has the following attributes: d29339 2 a29340 2 An integer identifying this instruction. 'number' corresponds to the numbers seen in 'record instruction-history' (*note Process d29344 2 a29345 2 A 'gdb.Symtab_and_line' object representing the associated symtab and line of this instruction. May be 'None' if no debug d29353 1 a29353 1 error is represented by a 'gdb.RecordGap' object in the instruction d29357 2 a29358 2 An integer identifying this gap. 'number' corresponds to the numbers seen in 'record instruction-history' (*note Process Record d29368 1 a29368 1 A 'gdb.RecordFunctionSegment' object has the following attributes: d29371 2 a29372 2 An integer identifying this function segment. 'number' corresponds to the numbers seen in 'record function-call-history' (*note d29376 2 a29377 2 A 'gdb.Symbol' object representing the associated symbol. May be 'None' if no debug information is available. d29381 1 a29381 1 'None' if the function call is a gap. d29384 1 a29384 1 A list of 'gdb.RecordInstruction' or 'gdb.RecordGap' objects d29388 1 a29388 1 A 'gdb.RecordFunctionSegment' object representing the caller's d29391 1 a29391 1 nor the return have been recorded, this will be 'None'. d29394 2 a29395 2 A 'gdb.RecordFunctionSegment' object representing the previous segment of this function call. May be 'None'. d29398 2 a29399 2 A 'gdb.RecordFunctionSegment' object representing the next segment of this function call. May be 'None'. d29471 1 a29471 1 implemented using an instance of the 'gdb.Command' class, most commonly d29476 1 a29476 1 The object initializer for 'Command' registers the new command with d29478 1 a29478 1 '__init__' method. d29487 1 a29487 1 COMMAND_CLASS should be one of the 'COMMAND_' constants defined d29492 1 a29492 1 one of the 'COMPLETE_' constants defined below. This argument d29494 1 a29494 1 given, GDB will attempt to complete using the object's 'complete' d29498 1 a29498 1 PREFIX is an optional argument. If 'True', then the new command is d29509 1 a29509 1 by invoking the 'dont_repeat' method at some point in its 'invoke' d29511 1 a29511 1 similar to the user command 'dont-repeat', see *note dont-repeat: d29524 1 a29524 1 If this method throws an exception, it is turned into a GDB 'error' d29528 2 a29529 2 'gdb.string_to_argv'. This function behaves identically to GDB's internal argument lexer 'buildargv'. It is recommended to use this d29540 1 a29540 1 the 'complete' command (*note complete: Help.). d29547 3 a29549 3 The 'complete' method can return several values: * If the return value is a sequence, the contents of the sequence are used as the completions. It is up to 'complete' d29555 1 a29555 1 * If the return value is one of the 'COMPLETE_' constants d29559 1 a29559 1 * All other results are treated as though there were no d29567 1 a29567 1 defined in the 'gdb' module: d29569 1 a29569 1 'gdb.COMMAND_NONE' d29573 1 a29573 1 'gdb.COMMAND_RUNNING' d29575 2 a29576 2 'start', 'step', and 'continue' are in this category. Type 'help running' at the GDB prompt to see a list of commands in this d29579 3 a29581 3 'gdb.COMMAND_DATA' The command is related to data or variables. For example, 'call', 'find', and 'print' are in this category. Type 'help data' at the d29584 1 a29584 1 'gdb.COMMAND_STACK' d29586 2 a29587 2 'backtrace', 'frame', and 'return' are in this category. Type 'help stack' at the GDB prompt to see a list of commands in this d29590 3 a29592 3 'gdb.COMMAND_FILES' This class is used for file-related commands. For example, 'file', 'list' and 'section' are in this category. Type 'help files' at d29595 1 a29595 1 'gdb.COMMAND_SUPPORT' d29598 2 a29599 2 not related to the state of the inferior. For example, 'help', 'make', and 'shell' are in this category. Type 'help support' at d29602 4 a29605 4 'gdb.COMMAND_STATUS' The command is an 'info'-related command, that is, related to the state of GDB itself. For example, 'info', 'macro', and 'show' are in this category. Type 'help status' at the GDB prompt to see a d29608 4 a29611 4 'gdb.COMMAND_BREAKPOINTS' The command has to do with breakpoints. For example, 'break', 'clear', and 'delete' are in this category. Type 'help breakpoints' at the GDB prompt to see a list of commands in this d29614 4 a29617 4 'gdb.COMMAND_TRACEPOINTS' The command has to do with tracepoints. For example, 'trace', 'actions', and 'tfind' are in this category. Type 'help tracepoints' at the GDB prompt to see a list of commands in this d29620 1 a29620 1 'gdb.COMMAND_TUI' d29622 1 a29622 1 Type 'help tui' at the GDB prompt to see a list of commands in this d29625 1 a29625 1 'gdb.COMMAND_USER' d29627 2 a29628 2 typically does not fit in one of the other categories. Type 'help user-defined' at the GDB prompt to see a list of commands in this d29631 1 a29631 1 'gdb.COMMAND_OBSCURE' d29633 2 a29634 2 general interest to users. For example, 'checkpoint', 'fork', and 'stop' are in this category. Type 'help obscure' at the GDB prompt d29637 4 a29640 4 'gdb.COMMAND_MAINTENANCE' The command is only useful to GDB maintainers. The 'maintenance' and 'flushregs' commands are in this category. Type 'help internals' at the GDB prompt to see a list of commands in this d29645 2 a29646 2 the 'complete' method. These predefined completion constants are all defined in the 'gdb' module: d29648 1 a29648 1 'gdb.COMPLETE_NONE' d29651 1 a29651 1 'gdb.COMPLETE_FILENAME' d29654 1 a29654 1 'gdb.COMPLETE_LOCATION' d29658 1 a29658 1 'gdb.COMPLETE_COMMAND' d29662 1 a29662 1 'gdb.COMPLETE_SYMBOL' d29666 1 a29666 1 'gdb.COMPLETE_EXPRESSION' d29687 1 a29687 1 is read into GDB, you may need to import the 'gdb' module explicitly. d29697 1 a29697 1 'gdb.MICommand' class, most commonly using a subclass. d29700 1 a29700 1 The object initializer for 'MICommand' registers the new command d29702 1 a29702 1 own '__init__' method. d29705 1 a29705 1 GDB/MI command, and in particular must start with a hyphen ('-'). d29707 1 a29707 1 'RuntimeError' will be raised. Using the name of an GDB/MI command d29714 3 a29716 3 ARGUMENTS is a list of strings. Note, that '--thread' and '--frame' arguments are handled by GDB itself therefore they do not show up in 'arguments'. d29719 1 a29719 1 '^error' response. Only 'gdb.GdbError' exceptions (or its d29721 1 a29721 1 other exception type is treated as a failure of the 'invoke' d29723 2 a29724 2 according to the 'set python print-stack' setting (*note 'set python print-stack': set_python_print_stack.). d29726 2 a29727 2 If this method returns 'None', then the GDB/MI command will return a '^done' response with no additional values. d29736 1 a29736 1 * If the value is Python sequence or iterator, it is converted d29739 1 a29739 1 * If the value is Python dictionary, it is converted to GDB/MI d29744 2 a29745 2 * Otherwise, value is first converted to a Python string using 'str ()' and then converted to GDB/MI CONST. d29749 1 a29749 1 character long, the first character must be in the set '[a-zA-Z]', d29751 1 a29751 1 '[-_a-zA-Z0-9]'. d29753 1 a29753 1 An instance of 'MICommand' has the following attributes: d29757 1 a29757 1 '__init__' method. This attribute is read-only. d29763 1 a29763 1 will be 'True'. d29767 1 a29767 1 be 'False'. d29769 1 a29769 1 This attribute is read-write, setting this attribute to 'False' d29771 1 a29771 1 commands. Setting this attribute to 'True' will install the d29800 2 a29801 2 three new GDB/MI commands '-echo-dict', '-echo-list', and '-echo-string'. Each time a subclass of 'gdb.MICommand' is d29805 1 a29805 1 import the 'gdb' module explicitly. d29823 1 a29823 1 string. This is done with the 'gdb.execute_mi' function. d29854 1 a29854 1 'gdb.notify_mi' function to do that. d29859 1 a29859 1 ('-'). DATA is any additional data to be emitted with the d29865 1 a29865 1 If DATA is 'None' then no additional values are emitted. d29868 2 a29869 2 Records::) with 'gdb.notify_mi' is allowed, users are encouraged to prefix user-defined notification with a hyphen ('-') to avoid possible d29872 1 a29872 1 Here is how to emit '=-connection-removed' whenever a connection to d29894 1 a29894 1 implemented as an instance of the 'gdb.Parameter' class. d29896 1 a29896 1 Parameters are exposed to the user via the 'set' and 'show' commands. d29900 1 a29900 1 Two examples are: 'set follow fork' and 'set charset'. Setting these d29907 1 a29907 1 The object initializer for 'Parameter' registers the new parameter d29909 1 a29909 1 own '__init__' method. d29913 2 a29914 2 parameters. An example of this can be illustrated with the 'set print' set of parameters. If NAME is 'print foo', then 'print' d29916 1 a29916 1 parameter can subsequently be accessed in GDB as 'set print foo'. d29921 1 a29921 1 COMMAND_CLASS should be one of the 'COMMAND_' constants (*note CLI d29925 1 a29925 1 PARAMETER_CLASS should be one of the 'PARAM_' constants defined d29929 1 a29929 1 If PARAMETER_CLASS is 'PARAM_ENUM', then ENUM_SEQUENCE must be a d29933 1 a29933 1 If PARAMETER_CLASS is not 'PARAM_ENUM', then the presence of a d29940 1 a29940 1 'help set' and 'help show' commands, and should be written taking d29945 1 a29945 1 as the first part of the help text for this parameter's 'set' d29949 1 a29949 1 The value of 'set_doc' should give a brief summary specific to the d29951 1 a29951 1 'help set' command for this parameter. The class documentation d29953 2 a29954 2 does, this text is displayed for both the 'help set' and 'help show' commands. d29956 1 a29956 1 The 'set_doc' value is examined when 'Parameter.__init__' is d29961 1 a29961 1 as the first part of the help text for this parameter's 'show' d29965 1 a29965 1 The value of 'show_doc' should give a brief summary specific to the d29967 1 a29967 1 'help show' command for this parameter. The class documentation d29969 2 a29970 2 does, this text is displayed for both the 'help set' and 'help show' commands. d29972 1 a29972 1 The 'show_doc' value is examined when 'Parameter.__init__' is d29976 1 a29976 1 The 'value' attribute holds the underlying value of the parameter. d29980 1 a29980 1 There are two methods that may be implemented in any 'Parameter' d29985 2 a29986 2 has been changed via the 'set' API (for example, 'set foo off'). The 'value' attribute has already been populated with the new value d29990 1 a29990 1 If this method raises the 'gdb.GdbError' exception (*note Exception d29992 1 a29992 1 'set' command will fail. Note, however, that the 'value' attribute d30014 2 a30015 2 GDB will call this method when a PARAMETER's 'show' API has been invoked (for example, 'show foo'). The argument 'svalue' receives d30020 1 a30020 1 available types are represented by constants defined in the 'gdb' d30023 3 a30025 3 'gdb.PARAM_BOOLEAN' The value is a plain boolean. The Python boolean values, 'True' and 'False' are the only valid values. d30027 2 a30028 2 'gdb.PARAM_AUTO_BOOLEAN' The value has three possible states: true, false, and 'auto'. In d30030 1 a30030 1 'auto' is represented using 'None'. d30032 3 a30034 3 'gdb.PARAM_UINTEGER' The value is an unsigned integer. The value of 'None' should be interpreted to mean "unlimited" (literal ''unlimited'' can also be d30038 3 a30040 3 'gdb.PARAM_INTEGER' The value is a signed integer. The value of 'None' should be interpreted to mean "unlimited" (literal ''unlimited'' can also be d30044 1 a30044 1 'gdb.PARAM_STRING' d30046 1 a30046 1 escape sequences, such as '\t', '\f', and octal escapes, are d30050 1 a30050 1 'gdb.PARAM_STRING_NOESCAPE' d30054 2 a30055 2 'gdb.PARAM_OPTIONAL_FILENAME' The value is a either a filename (a string), or 'None'. d30057 1 a30057 1 'gdb.PARAM_FILENAME' d30059 1 a30059 1 'PARAM_STRING_NOESCAPE', but uses file names for completion. d30061 12 a30072 12 'gdb.PARAM_ZINTEGER' The value is a signed integer. This is like 'PARAM_INTEGER', except that 0 is allowed and the value of 'None' is not supported. 'gdb.PARAM_ZUINTEGER' The value is an unsigned integer. This is like 'PARAM_UINTEGER', except that 0 is allowed and the value of 'None' is not supported. 'gdb.PARAM_ZUINTEGER_UNLIMITED' The value is a signed integer. This is like 'PARAM_INTEGER' including that the value of 'None' should be interpreted to mean "unlimited" (literal ''unlimited'' can also be used to set that d30077 1 a30077 1 'gdb.PARAM_ENUM' d30089 1 a30089 1 class 'gdb.Function'. d30092 1 a30092 1 The initializer for 'Function' registers the new function with GDB. d30095 1 a30095 1 type 'internal function', whose name is the same as the given NAME. d30102 2 a30103 2 converted to instances of 'gdb.Value', and then the function's 'invoke' method is called. Note that GDB does not predetermine the d30105 1 a30105 1 are passed to 'invoke', following the standard Python calling d30111 1 a30111 1 is converted to a 'gdb.Value' following the usual rules. d30130 1 a30130 1 is read into GDB, you may need to import the 'gdb' module explicitly. d30143 1 a30143 1 A program space, or "progspace", represents a symbolic view of an d30148 1 a30148 1 The following progspace-related functions are available in the 'gdb' d30154 1 a30154 1 identical to 'gdb.selected_inferior().progspace' (*note Inferiors d30160 1 a30160 1 Each progspace is represented by an instance of the 'gdb.Progspace' d30166 1 a30166 1 argument to the 'symbol-file' or 'file' commands. d30169 1 a30169 1 attribute will be 'None'. d30172 3 a30174 3 The 'gdb.Objfile' representing the main symbol file (from which debug symbols have been loaded) for the 'gdb.Progspace'. This is the symbol file set by the 'symbol-file' or 'file' commands. d30176 2 a30177 2 This will be the 'gdb.Objfile' representing 'Progspace.filename' when 'Progspace.filename' is not 'None'. d30180 1 a30180 1 attribute will be 'None'. d30182 3 a30184 3 If the 'Progspace' is invalid, i.e., when 'Progspace.is_valid()' returns 'False', then attempting to access this attribute will raise a 'RuntimeError' exception. d30190 2 a30191 2 The file name within this attribute is updated by the 'exec-file' and 'file' commands. d30193 2 a30194 2 If no executable is currently set within this 'Progspace' then this attribute contains 'None'. d30196 3 a30198 3 If the 'Progspace' is invalid, i.e., when 'Progspace.is_valid()' returns 'False', then attempting to access this attribute will raise a 'RuntimeError' exception. d30201 3 a30203 3 The 'pretty_printers' attribute is a list of functions. It is used to look up pretty-printers. A 'Value' is passed to each function in order; if the function returns 'None', then the search d30209 1 a30209 1 The 'type_printers' attribute is a list of type printer objects. d30213 1 a30213 1 The 'frame_filters' attribute is a dictionary of frame filter d30217 1 a30217 1 The 'missing_debug_handlers' attribute is a list of the missing d30224 1 a30224 1 Return the innermost 'gdb.Block' containing the given PC value. If d30226 1 a30226 1 will return 'None'. d30229 1 a30229 1 Return the 'gdb.Symtab_and_line' object corresponding to the PC d30231 2 a30232 2 is passed as an argument, then the 'symtab' and 'line' attributes of the returned 'gdb.Symtab_and_line' object will be 'None' and 0 d30236 2 a30237 2 Returns 'True' if the 'gdb.Progspace' object is valid, 'False' if not. A 'gdb.Progspace' object can become invalid if the program d30239 1 a30239 1 other 'gdb.Progspace' methods will throw an exception if it is d30248 1 a30248 1 a string, or 'None'. d30251 1 a30251 1 Return the 'gdb.Objfile' holding the given address, or 'None' if no d30254 1 a30254 1 One may add arbitrary attributes to 'gdb.Progspace' objects in the d30308 1 a30308 1 "objfiles". d30310 1 a30310 1 The following objfile-related functions are available in the 'gdb' d30317 1 a30317 1 objfile, this function returns 'None'. d30323 1 a30323 1 'gdb.selected_inferior().progspace.objfiles()' and is included for d30329 1 a30329 1 objfile is not found throw the Python 'ValueError' exception. d30333 3 a30335 3 'gcc/expr.c', then it will match source file name of '/build/trunk/gcc/expr.c', but not '/build/trunk/libcpp/expr.c' or '/build/trunk/gcc/x-expr.c'. d30337 1 a30337 1 If BY_BUILD_ID is provided and is 'True' then NAME is the build ID d30341 1 a30341 1 about this feature, see the description of the '--build-id' d30344 1 a30344 1 Each objfile is represented by an instance of the 'gdb.Objfile' d30351 2 a30352 2 The value is 'None' if the objfile is no longer valid. See the 'gdb.Objfile.is_valid' method, described below. d30357 2 a30358 2 The value is 'None' if the objfile is no longer valid. See the 'gdb.Objfile.is_valid' method, described below. d30363 1 a30363 1 'True' for file-backed objfiles, and 'False' for other kinds. d30367 3 a30369 3 'gdb.Objfile' object that debug info is being provided for. Otherwise this is 'None'. Separate debug info objfiles are added with the 'gdb.Objfile.add_separate_debug_file' method, described d30374 1 a30374 1 have a build ID then the value is 'None'. d30379 1 a30379 1 '--build-id' command-line option in *note Command Line Options: d30383 1 a30383 1 The containing program space of the objfile as a 'gdb.Progspace' d30387 3 a30389 3 The 'pretty_printers' attribute is a list of functions. It is used to look up pretty-printers. A 'Value' is passed to each function in order; if the function returns 'None', then the search d30395 1 a30395 1 The 'type_printers' attribute is a list of type printer objects. d30399 1 a30399 1 The 'frame_filters' attribute is a dictionary of frame filter d30402 1 a30402 1 One may add arbitrary attributes to 'gdb.Objfile' objects in the d30424 1 a30424 1 A 'gdb.Objfile' object has the following methods: d30427 2 a30428 2 Returns 'True' if the 'gdb.Objfile' object is valid, 'False' if not. A 'gdb.Objfile' object can become invalid if the object file d30430 1 a30430 1 'gdb.Objfile' methods will throw an exception if it is invalid at d30445 1 a30445 1 DOMAIN argument must be a domain constant defined in the 'gdb' d30447 1 a30447 1 is similar to 'gdb.lookup_global_symbol', except that the search is d30450 1 a30450 1 The result is a 'gdb.Symbol' object or 'None' if the symbol is not d30454 1 a30454 1 Like 'Objfile.lookup_global_symbol', but searches for a global d30464 2 a30465 2 (*note Stack frames: Frames.). The 'gdb.Frame' class represents a frame in the stack. A 'gdb.Frame' object is only valid while its d30467 1 a30467 1 an invalid frame object, GDB will throw a 'gdb.error' exception (*note d30470 1 a30470 1 Two 'gdb.Frame' objects can be compared for equality with the '==' d30476 1 a30476 1 The following frame-related functions are available in the 'gdb' d30489 1 a30489 1 'unwind_stop_reason' method further down in this section). d30498 1 a30498 1 A 'gdb.Frame' object has the following methods: d30501 1 a30501 1 Returns true if the 'gdb.Frame' object is valid, false if not. A d30503 1 a30503 1 exist anymore in the inferior. All 'gdb.Frame' methods will throw d30507 1 a30507 1 Returns the function name of the frame, or 'None' if it can't be d30511 1 a30511 1 Returns the 'gdb.Architecture' object corresponding to the frame's d30516 1 a30516 1 'gdb.NORMAL_FRAME' d30519 1 a30519 1 'gdb.DUMMY_FRAME' d30523 1 a30523 1 'gdb.INLINE_FRAME' d30525 1 a30525 1 inlined into a 'gdb.NORMAL_FRAME' that is older than this one. d30527 1 a30527 1 'gdb.TAILCALL_FRAME' d30530 1 a30530 1 'gdb.SIGTRAMP_FRAME' d30534 1 a30534 1 'gdb.ARCH_FRAME' d30537 2 a30538 2 'gdb.SENTINEL_FRAME' This is like 'gdb.NORMAL_FRAME', but it is only used for the d30544 1 a30544 1 'gdb.frame_stop_reason_string' to convert the value returned by d30547 1 a30547 1 'gdb.FRAME_UNWIND_NO_REASON' d30550 1 a30550 1 'gdb.FRAME_UNWIND_NULL_ID' d30555 1 a30555 1 'gdb.FRAME_UNWIND_OUTERMOST' d30558 1 a30558 1 'gdb.FRAME_UNWIND_UNAVAILABLE' d30562 1 a30562 1 'gdb.FRAME_UNWIND_INNER_ID' d30567 1 a30567 1 'gdb.FRAME_UNWIND_SAME_ID' d30574 1 a30574 1 'gdb.FRAME_UNWIND_NO_SAVED_PC' d30578 1 a30578 1 'gdb.FRAME_UNWIND_MEMORY_ERROR' d30582 1 a30582 1 'gdb.FRAME_UNWIND_FIRST_ERROR' d30608 1 a30608 1 frame, return 'None'. d30612 1 a30612 1 frame, return 'None'. d30619 1 a30619 1 Return the value of REGISTER in this frame. Returns a 'Gdb.Value' d30622 3 a30624 3 1. A string that is the name of a valid register (e.g., ''sp'' or ''rax''). 2. A 'gdb.RegisterDescriptor' object (*note Registers In d30631 1 a30631 1 usually found in the corresponding 'PLATFORM-tdep.h' file in d30636 1 a30636 1 looking up and caching a 'gdb.RegisterDescriptor' object. d30643 2 a30644 2 argument must be a string or a 'gdb.Symbol' object; BLOCK must be a 'gdb.Block' object. d30657 1 a30657 1 If there is no static link, this method returns 'None'. d30674 1 a30674 1 represented individually in Python as a 'gdb.Block'. Blocks rely on d30680 1 a30680 1 The outermost block is known as the "global block". The global block d30683 1 a30683 1 The block nested just inside the global block is the "static block". d30718 1 a30718 1 A 'gdb.Block' is iterable. The iterator returns the symbols (*note d30722 2 a30723 2 across blocks in a symbol table. You can also use Python's "dictionary syntax" to access variables in this block, e.g.: d30727 1 a30727 1 The following block-related functions are available in the 'gdb' d30731 1 a30731 1 Return the innermost 'gdb.Block' containing the given PC value. If d30733 2 a30734 2 will return 'None'. This is identical to 'gdb.current_progspace().block_for_pc(pc)' and is included for d30737 1 a30737 1 A 'gdb.Block' object has the following methods: d30740 1 a30740 1 Returns 'True' if the 'gdb.Block' object is valid, 'False' if not. d30742 1 a30742 1 exist anymore in the inferior. All other 'gdb.Block' methods will d30747 1 a30747 1 A 'gdb.Block' object has the following attributes: d30757 2 a30758 2 The name of the block represented as a 'gdb.Symbol'. If the block is not named, then this attribute holds 'None'. This attribute is d30768 1 a30768 1 exist, this attribute holds 'None'. This attribute is not d30780 1 a30780 1 'True' if the 'gdb.Block' object is a global block, 'False' if not. d30784 1 a30784 1 'True' if the 'gdb.Block' object is a static block, 'False' if not. d30795 1 a30795 1 represents these symbols in GDB with the 'gdb.Symbol' object. d30797 1 a30797 1 The following symbol-related functions are available in the 'gdb' d30807 1 a30807 1 BLOCK. The BLOCK argument must be a 'gdb.Block' object. If d30810 1 a30810 1 DOMAIN argument must be a domain constant defined in the 'gdb' d30814 5 a30818 5 'gdb.Symbol' object or 'None' if the symbol is not found. If the symbol is found, the second element is 'True' if the symbol is a field of a method's object (e.g., 'this' in C++), otherwise it is 'False'. If the symbol is not found, the second element is 'False'. d30826 1 a30826 1 DOMAIN argument must be a domain constant defined in the 'gdb' d30829 1 a30829 1 The result is a 'gdb.Symbol' object or 'None' if the symbol is not d30839 1 a30839 1 DOMAIN argument must be a domain constant defined in the 'gdb' d30842 1 a30842 1 The result is a 'gdb.Symbol' object or 'None' if the symbol is not d30847 2 a30848 2 of the function's 'gdb.Block' and check that 'block.addr_class' is 'gdb.SYMBOL_LOC_STATIC'. d30859 1 a30859 1 Similar to 'gdb.lookup_static_symbol', this function searches for d30866 1 a30866 1 DOMAIN argument must be a domain constant defined in the 'gdb' d30869 1 a30869 1 The result is a list of 'gdb.Symbol' objects which could be empty d30874 2 a30875 2 of the function's 'gdb.Block' and check that 'block.addr_class' is 'gdb.SYMBOL_LOC_STATIC'. d30877 1 a30877 1 A 'gdb.Symbol' object has the following attributes: d30880 2 a30881 2 The type of the symbol or 'None' if no type is recorded. This attribute is represented as a 'gdb.Type' object. *Note Types In d30886 1 a30886 1 represented as a 'gdb.Symtab' object. *Note Symbol Tables In d30903 1 a30903 1 either 'name' or 'linkage_name', depending on whether the user d30909 1 a30909 1 'gdb' module and described later in this chapter. d30912 2 a30913 2 This is 'True' if evaluating this symbol's value requires a frame (*note Frames In Python::) and 'False' otherwise. Typically, local d30917 1 a30917 1 'True' if the symbol is an argument of a function. d30920 1 a30920 1 'True' if the symbol is a constant. d30923 1 a30923 1 'True' if the symbol is a function or a method. d30926 2 a30927 2 'True' if the symbol is a variable, as opposed to something like a function or type. Note that this also returns 'False' for d30930 1 a30930 1 A 'gdb.Symbol' object has the following methods: d30933 3 a30935 3 Returns 'True' if the 'gdb.Symbol' object is valid, 'False' if not. A 'gdb.Symbol' object can become invalid if the symbol it refers to does not exist in GDB any longer. All other 'gdb.Symbol' methods d30940 1 a30940 1 Compute the value of the symbol, as a 'gdb.Value'. For functions, d30946 2 a30947 2 The available domain categories in 'gdb.Symbol' are represented as constants in the 'gdb' module: d30949 1 a30949 1 'gdb.SYMBOL_UNDEF_DOMAIN' d30954 1 a30954 1 'gdb.SYMBOL_VAR_DOMAIN' d30957 1 a30957 1 'gdb.SYMBOL_FUNCTION_DOMAIN' d30960 1 a30960 1 'gdb.SYMBOL_TYPE_DOMAIN' d30962 1 a30962 1 tag (the name appearing after a 'struct', 'union', or 'enum' d30966 1 a30966 1 'gdb.SYMBOL_STRUCT_DOMAIN' d30971 2 a30972 2 Here 'type_one' will be in 'SYMBOL_STRUCT_DOMAIN', but 'type_two' will be in 'SYMBOL_TYPE_DOMAIN'. d30974 1 a30974 1 'gdb.SYMBOL_LABEL_DOMAIN' d30977 1 a30977 1 'gdb.SYMBOL_MODULE_DOMAIN' d30980 1 a30980 1 'gdb.SYMBOL_COMMON_BLOCK_DOMAIN' d30988 3 a30990 3 each named after one of the preceding constants, but with the 'SEARCH' prefix replacing the 'SYMBOL' prefix; for example, 'SEARCH_LABEL_DOMAIN'. These may be or'd together to form a search d30995 2 a30996 2 The available address class categories in 'gdb.Symbol' are represented as constants in the 'gdb' module: d30998 1 a30998 1 'gdb.SYMBOL_LOC_UNDEF' d31002 1 a31002 1 'gdb.SYMBOL_LOC_CONST' d31005 1 a31005 1 'gdb.SYMBOL_LOC_STATIC' d31008 1 a31008 1 'gdb.SYMBOL_LOC_REGISTER' d31011 1 a31011 1 'gdb.SYMBOL_LOC_ARG' d31015 1 a31015 1 'gdb.SYMBOL_LOC_REF_ARG' d31017 1 a31017 1 'LOC_ARG' except that the value's address is stored at the offset, d31020 2 a31021 2 'gdb.SYMBOL_LOC_REGPARM_ADDR' Value is a specified register. Just like 'LOC_REGISTER' except the d31025 1 a31025 1 'gdb.SYMBOL_LOC_LOCAL' d31028 2 a31029 2 'gdb.SYMBOL_LOC_TYPEDEF' Value not used. Symbols in the domain 'SYMBOL_STRUCT_DOMAIN' all d31032 1 a31032 1 'gdb.SYMBOL_LOC_LABEL' d31035 1 a31035 1 'gdb.SYMBOL_LOC_BLOCK' d31038 1 a31038 1 'gdb.SYMBOL_LOC_CONST_BYTES' d31041 1 a31041 1 'gdb.SYMBOL_LOC_UNRESOLVED' d31046 1 a31046 1 'gdb.SYMBOL_LOC_OPTIMIZED_OUT' d31049 1 a31049 1 'gdb.SYMBOL_LOC_COMPUTED' d31052 1 a31052 1 'gdb.SYMBOL_LOC_COMMON_BLOCK' d31063 3 a31065 3 to Python via two objects: 'gdb.Symtab_and_line' and 'gdb.Symtab'. Symbol table and line data for a frame is returned from the 'find_sal' method in 'gdb.Frame' object. *Note Frames In Python::. d31070 1 a31070 1 A 'gdb.Symtab_and_line' object has the following attributes: d31073 1 a31073 1 The symbol table object ('gdb.Symtab') for this frame. This d31088 1 a31088 1 A 'gdb.Symtab_and_line' object has the following methods: d31091 2 a31092 2 Returns 'True' if the 'gdb.Symtab_and_line' object is valid, 'False' if not. A 'gdb.Symtab_and_line' object can become invalid d31094 1 a31094 1 GDB any longer. All other 'gdb.Symtab_and_line' methods will throw d31097 1 a31097 1 A 'gdb.Symtab' object has the following attributes: d31110 1 a31110 1 the compiler. If no producer information is available then 'None' d31113 1 a31113 1 A 'gdb.Symtab' object has the following methods: d31116 3 a31118 3 Returns 'True' if the 'gdb.Symtab' object is valid, 'False' if not. A 'gdb.Symtab' object can become invalid if the symbol table it refers to does not exist in GDB any longer. All other 'gdb.Symtab' d31146 1 a31146 1 information for a particular symbol table, use the 'linetable' function d31149 1 a31149 1 A 'gdb.LineTable' is iterable. The iterator returns 'LineTableEntry' d31151 1 a31151 1 table entry. 'LineTableEntry' objects have the following attributes: d31164 3 a31166 3 receive multiple 'LineTableEntry' objects with matching 'line' attributes, but with different 'pc' attributes. The iterator is sorted in ascending 'pc' order. Here is a small example illustrating iterating d31185 1 a31185 1 In addition to being able to iterate over a 'LineTable', it also has d31189 1 a31189 1 Return a Python 'Tuple' of 'LineTableEntry' objects for any entries d31192 1 a31192 1 Python 'None' is returned. d31195 3 a31197 3 Return a Python 'Boolean' indicating whether there is an entry in the line table for this source line. Return 'True' if an entry is found, or 'False' if not. d31200 1 a31200 1 Return a Python 'List' of the source line numbers in the symbol d31202 2 a31203 2 The contents of the 'List' will just be the source line entries represented as Python 'Long' values. d31211 1 a31211 1 Python code can manipulate breakpoints via the 'gdb.Breakpoint' class. d31214 3 a31216 3 'gdb.Breakpoint' constructor. The first one accepts a string like one would pass to the 'break' (*note Setting Breakpoints: Set Breaks.) and 'watch' (*note Setting Watchpoints: Set Watchpoints.) commands, and can d31226 2 a31227 2 recognized by the 'break' command (*note Setting Breakpoints: Set Breaks.) or, in the case of a watchpoint, by the 'watch' command d31234 2 a31235 2 create, if TYPE is 'gdb.BP_WATCHPOINT'. If WP_CLASS is omitted, it defaults to 'gdb.WP_WRITE'. d31239 2 a31240 2 when created, nor will it be listed in the output from 'info breakpoints' (but will be listed with the 'maint info breakpoints' d31250 2 a31251 2 interpreting the function passed in 'spec' as a fully-qualified name. It is equivalent to 'break''s '-qualified' flag (*note d31264 1 a31264 1 The available types are represented by constants defined in the 'gdb' d31267 1 a31267 1 'gdb.BP_BREAKPOINT' d31270 1 a31270 1 'gdb.BP_HARDWARE_BREAKPOINT' d31273 1 a31273 1 'gdb.BP_WATCHPOINT' d31276 1 a31276 1 'gdb.BP_HARDWARE_WATCHPOINT' d31279 1 a31279 1 'gdb.BP_READ_WATCHPOINT' d31282 1 a31282 1 'gdb.BP_ACCESS_WATCHPOINT' d31285 1 a31285 1 'gdb.BP_CATCHPOINT' d31287 2 a31288 2 'gdb.Breakpoint' objects, but will be present in 'gdb.Breakpoint' objects reported from 'gdb.BreakpointEvent's (*note Events In d31292 1 a31292 1 in the 'gdb' module: d31294 1 a31294 1 'gdb.WP_READ' d31297 1 a31297 1 'gdb.WP_WRITE' d31300 1 a31300 1 'gdb.WP_ACCESS' d31304 3 a31306 3 The 'gdb.Breakpoint' class can be sub-classed and, in particular, you may choose to implement the 'stop' method. If this method is defined in a sub-class of 'gdb.Breakpoint', it will be called when d31308 1 a31308 1 instantiates that sub-class. If the method returns 'True', the d31313 2 a31314 2 'stop' method, each one will be called regardless of the return status of the previous. This ensures that all 'stop' methods have d31316 1 a31316 1 the methods returns 'True' but the others return 'False', the d31325 1 a31325 1 Example 'stop' implementation: d31335 2 a31336 2 Return 'True' if this 'Breakpoint' object is valid, 'False' otherwise. A 'Breakpoint' object can become invalid if the user d31344 1 a31344 1 Python 'Breakpoint' object. Any further access to this object's d31348 1 a31348 1 This attribute is 'True' if the breakpoint is enabled, and 'False' d31353 1 a31353 1 This attribute is 'True' if the breakpoint is silent, and 'False' d31357 2 a31358 2 the first command is 'silent'. This is not reported by the 'silent' attribute. d31361 1 a31361 1 This attribute is 'True' if the breakpoint is pending, and 'False' d31367 1 a31367 1 the breakpoint is not thread-specific, this attribute is 'None'. d31370 1 a31370 1 Only one of 'Breakpoint.thread' or 'Breakpoint.inferior' can be set d31377 1 a31377 1 breakpoint is not inferior-specific, this attribute is 'None'. d31380 1 a31380 1 'gdb.BP_BREAKPOINT' and 'gdb.BP_HARDWARE_BREAKPOINT'. d31385 1 a31385 1 underlying language is not Ada), this attribute is 'None'. This d31404 1 a31404 1 when set, or when the 'info breakpoints' command is run. This d31412 1 a31412 1 'is_valid' function, will result in an error after the breakpoint d31425 1 a31425 1 'None'. This attribute is not writable. d31429 3 a31431 3 for this breakpoint, with elements of type 'gdb.BreakpointLocation' (described below). This functionality matches that of the 'info breakpoint' command (*note Set Breaks::), in that it only retrieves d31440 1 a31440 1 value is 'None'. This attribute is not writable. d31445 1 a31445 1 attribute's value is 'None'. This attribute is writable. d31451 1 a31451 1 this attribute is 'None'. This attribute is writable. d31457 1 a31457 1 been set, represented in the Python API by the 'gdb.BreakpointLocation' d31459 1 a31459 1 retrieved from 'Breakpoint.locations' which returns a list of breakpoint d31463 2 a31464 2 location will throw a 'RuntimeError' exception. Access the 'Breakpoint.locations' attribute again to retrieve the new and valid d31472 1 a31472 1 catchpoints. This will throw a 'RuntimeError' exception if the d31477 1 a31477 1 This attribute is of type long. This will throw a 'RuntimeError' d31484 1 a31484 1 'RuntimeError' exception if the location has been invalidated. d31487 3 a31489 3 This attribute holds a reference to the 'gdb.Breakpoint' owner object, from which this 'gdb.BreakpointLocation' was retrieved from. This will throw a 'RuntimeError' exception if the location d31495 1 a31495 1 'None'. This will throw a 'RuntimeError' exception if the location d31500 2 a31501 2 If no full name could be found, this attribute returns 'None'. This will throw a 'RuntimeError' exception if the location has been d31506 1 a31506 1 'List' of the thread group ID's. This will throw a 'RuntimeError' d31517 2 a31518 2 of a frame, based on the 'finish' command. 'gdb.FinishBreakpoint' extends 'gdb.Breakpoint'. The underlying breakpoint will be disabled d31520 1 a31520 1 (i.e. 'Breakpoint.stop' or 'FinishBreakpoint.out_of_scope' triggered). d31525 1 a31525 1 Create a finish breakpoint at the return address of the 'gdb.Frame' d31532 1 a31532 1 In some circumstances (e.g. 'longjmp', C++ exceptions, GDB 'return' d31535 1 a31535 1 situation, the 'out_of_scope' callback will be triggered. d31537 1 a31537 1 You may want to sub-class 'gdb.FinishBreakpoint' and override this d31550 4 a31553 4 build the 'gdb.FinishBreakpoint' object had debug symbols, this attribute will contain a 'gdb.Value' object corresponding to the return value of the function. The value will be 'None' if the function return type is 'void' or if the return value was not d31562 1 a31562 1 A "lazy string" is a string whose contents is not retrieved or encoded d31565 7 a31571 7 A 'gdb.LazyString' is represented in GDB as an 'address' that points to a region of memory, an 'encoding' that will be used to encode that region of memory, and a 'length' to delimit the region of memory that represents the string. The difference between a 'gdb.LazyString' and a string wrapped within a 'gdb.Value' is that a 'gdb.LazyString' will be treated differently by GDB when printing. A 'gdb.LazyString' is retrieved and encoded during printing, while a 'gdb.Value' wrapping a d31574 1 a31574 1 A 'gdb.LazyString' object has the following functions: d31577 1 a31577 1 Convert the 'gdb.LazyString' to a 'gdb.Value'. This value will d31580 1 a31580 1 'gdb.LazyString'. d31603 1 a31603 1 'target' method. *Note Types In Python::. This attribute is not d31614 1 a31614 1 of the 'gdb.Architecture' class. d31616 1 a31616 1 A 'gdb.Architecture' class has the following methods: d31635 1 a31635 1 element of the returned list is a Python 'dict' with the following d31638 1 a31638 1 'addr' d31642 1 a31642 1 'asm' d31646 1 a31646 1 specified by the current CLI variable 'disassembly-flavor'. d31649 1 a31649 1 'length' d31661 2 a31662 2 If SIGNED is not specified, it defaults to 'True'. If SIGNED is 'False', the returned type will be unsigned. d31665 1 a31665 1 'ValueError' exception. d31668 1 a31668 1 Return a 'gdb.RegisterDescriptorIterator' (*note Registers In d31671 1 a31671 1 empty string, then the register group 'all' is assumed. d31674 1 a31674 1 Return a 'gdb.RegisterGroupsIterator' (*note Registers In Python::) d31676 1 a31676 1 'gdb.Architecture'. d31684 2 a31685 2 Python code can request from a 'gdb.Architecture' information about the set of registers available (*note 'Architecture.registers': d31687 2 a31688 2 a 'gdb.RegisterDescriptorIterator', which is an iterator that in turn returns 'gdb.RegisterDescriptor' objects. d31690 3 a31692 3 A 'gdb.RegisterDescriptor' does not provide the value of a register (*note 'Frame.read_register': gdbpy_frame_read_register. for reading a register's value), instead the 'RegisterDescriptor' is a way to discover d31695 1 a31695 1 A 'gdb.RegisterDescriptor' has the following read-only properties: d31701 1 a31701 1 using the following 'gdb.RegisterDescriptorIterator' function: d31705 1 a31705 1 'gdb.RegisterDescriptor' for the register with that name, or 'None' d31708 1 a31708 1 Python code can also request from a 'gdb.Architecture' information d31710 1 a31710 1 (*note 'Architecture.register_groups': gdbpy_architecture_reggroups.). d31717 1 a31717 1 commands like 'info registers' (*note 'info registers REGGROUP': d31721 2 a31722 2 'gdb.RegisterGroupsIterator', which is an iterator that in turn returns 'gdb.RegisterGroup' objects. d31724 1 a31724 1 A 'gdb.RegisterGroup' object has the following read-only properties: d31738 1 a31738 1 connection types are 'native' and 'remote'. *Note Inferiors Connections d31742 2 a31743 2 'gdb.TargetConnection', or as one of its sub-classes. To get a list of all connections use 'gdb.connections' (*note gdb.connections: d31746 2 a31747 2 To get the connection for a single 'gdb.Inferior' read its 'gdb.Inferior.connection' attribute (*note gdb.Inferior.connection: d31750 2 a31751 2 Currently there is only a single sub-class of 'gdb.TargetConnection', 'gdb.RemoteTargetConnection', however, additional sub-classes may be d31766 1 a31766 1 A 'gdb.TargetConnection' has the following method: d31769 2 a31770 2 Return 'True' if the 'gdb.TargetConnection' object is valid, 'False' if not. A 'gdb.TargetConnection' will become invalid if d31775 1 a31775 1 Reading any of the 'gdb.TargetConnection' properties will throw an d31778 1 a31778 1 A 'gdb.TargetConnection' has the following read-only properties: d31782 2 a31783 2 This is the same value as displayed in the 'Num' column of the 'info connections' command output (*note info connections: d31789 1 a31789 1 'target' command (*note target command: Target Commands.). d31793 2 a31794 2 is the same string that is displayed in the 'Description' column of the 'info connection' command output (*note info connections: d31799 1 a31799 1 connection. This attribute can be 'None' if there are no d31803 2 a31804 2 is the 'remote' connection, in this case the details string can contain the 'HOSTNAME:PORT' that was used to connect to the remote d31807 5 a31811 5 The 'gdb.RemoteTargetConnection' class is a sub-class of 'gdb.TargetConnection', and is used to represent 'remote' and 'extended-remote' connections. In addition to the attributes and methods available from the 'gdb.TargetConnection' base class, a 'gdb.RemoteTargetConnection' has the following method: d31815 2 a31816 2 response. The PACKET should either be a 'bytes' object, or a 'Unicode' string. d31818 3 a31820 3 If PACKET is a 'Unicode' string, then the string is encoded to a 'bytes' object using the ASCII codec. If the string can't be encoded then an 'UnicodeError' is raised. d31822 2 a31823 2 If PACKET is not a 'bytes' object, or a 'Unicode' string, then a 'TypeError' is raised. If PACKET is empty then a 'ValueError' is d31826 1 a31826 1 The response is returned as a 'bytes' object. If it is known that d31838 1 a31838 1 This is equivalent to the 'maintenance packet' command (*note maint d31857 1 a31857 1 '[a-zA-Z][-_.a-zA-Z0-9]*', it is an error to try and create a d31862 1 a31862 1 'gdb.TuiWindow', described below. It should return an object that d31866 1 a31866 1 an object of type 'gdb.TuiWindow'. This object has these methods and d31870 1 a31870 1 This method returns 'True' when this window is valid. When the d31872 1 a31872 1 layout will be destroyed. At this point, the 'gdb.TuiWindow' will d31874 1 a31874 1 'is_valid' will throw an exception. d31876 1 a31876 1 When the TUI is disabled using 'tui disable' (*note tui disable: d31878 1 a31878 1 'is_valid' will still return 'False' and other methods (and d31900 3 a31902 3 If the FULL_WINDOW parameter is 'True', then STRING contains the full contents of the window. This is similar to calling 'erase' before 'write', but avoids the flickering. d31915 2 a31916 2 When the TUI window is closed, the 'gdb.TuiWindow' object will be put into an invalid state. At this time, GDB will call 'close' d31926 1 a31926 1 layout. When this happens, GDB will call the 'render' method on d31931 1 a31931 1 and send output to the 'gdb.TuiWindow'. d31953 3 a31955 3 When TUI mouse events are disabled by turning off the 'tui mouse-events' setting (*note set tui mouse-events: tui-mouse-events.), then 'click' will not be called. d31965 1 a31965 1 'gdb.disassembler' module: d31976 1 a31976 1 description of '__init__' for more details. d31985 1 a31985 1 The 'gdb.Architecture' (*note Architectures In Python::) for d31990 1 a31990 1 The 'gdb.Progspace' (*note Program Spaces In Python: d31995 2 a31996 2 Returns 'True' if the 'DisassembleInfo' object is valid, 'False' if not. A 'DisassembleInfo' object will become d31998 3 a32000 3 'DisassembleInfo' was created, has returned. Calling other 'DisassembleInfo' methods, or accessing 'DisassembleInfo' properties, will raise a 'RuntimeError' exception if it is d32004 3 a32006 3 This can be used to create a new 'DisassembleInfo' object that is a copy of INFO. The copy will have the same 'address', 'architecture', and 'progspace' values as INFO, and will d32009 1 a32009 1 This method exists so that sub-classes of 'DisassembleInfo' d32011 2 a32012 2 copies of an existing 'DisassembleInfo' object, but sub-classes might choose to override the 'read_memory' method, d32019 1 a32019 1 bytes, starting at OFFSET from 'DisassembleInfo.address'. d32028 1 a32028 1 string, just as 'Inferior.read_memory' does (*note d32033 1 a32033 1 'gdb.MemoryError' exception is raised (*note Exception d32039 1 a32039 1 important to understand how 'builtin_disassemble' makes use of d32047 1 a32047 1 If an implementation of 'read_memory' is unable to read the d32050 1 a32050 1 'gdb.MemoryError' should be raised. d32052 3 a32054 3 Raising a 'MemoryError' inside 'read_memory' does not automatically mean a 'MemoryError' will be raised by 'builtin_disassemble'. It is possible the GDB's builtin d32056 1 a32056 1 When 'read_memory' raises the 'MemoryError' the builtin d32059 1 a32059 1 'builtin_disassemble' will not itself raise a 'MemoryError'. d32061 2 a32062 2 Any other exception type raised in 'read_memory' will propagate back and be re-raised by 'builtin_disassemble'. d32065 1 a32065 1 Create a new 'DisassemblerTextPart' representing a piece of a d32071 1 a32071 1 'DisassemblerResult' in order to represent the styling within d32075 1 a32075 1 Create a new 'DisassemblerAddressPart'. ADDRESS is the value d32077 1 a32077 1 'DisassemblerAddressPart' is displayed as an absolute address d32090 3 a32092 3 The '__call__' method must be overridden by sub-classes to perform disassembly. Calling '__call__' on this base class will raise a 'NotImplementedError' exception. d32094 1 a32094 1 The INFO argument is an instance of 'DisassembleInfo', and d32097 1 a32097 1 If this function returns 'None', this indicates to GDB that d32102 1 a32102 1 Alternatively, this function can return a 'DisassemblerResult' d32106 1 a32106 1 The '__call__' method can raise a 'gdb.MemoryError' exception d32111 3 a32113 3 Ideally, the only three outcomes from invoking '__call__' would be a return of 'None', a successful disassembly returned in a 'DisassemblerResult', or a 'MemoryError' indicating that d32116 1 a32116 1 However, as an implementation of '__call__' could fail due to d32118 2 a32119 2 disassembly is temporarily unavailable, then, if '__call__' raises a 'GdbError', the exception will be converted to a d32123 1 a32123 1 Any other exception type raised by the '__call__' method is d32125 2 a32126 2 printed to the error stream according to the 'set python print-stack' setting (*note 'set python print-stack': d32132 1 a32132 1 'builtin_disassemble' (*note builtin_disassemble::), and an d32134 1 a32134 1 'Disassembler.__call__' (*note Disassembler Class::) if an d32137 1 a32137 1 It is not possible to sub-class the 'DisassemblerResult' class. d32139 1 a32139 1 The 'DisassemblerResult' class has the following properties and d32148 2 a32149 2 'DisassemblerResult'; the other one should be passed the value 'None'. Alternatively, the arguments can be passed by name, d32152 1 a32152 1 The STRING argument, if not 'None', is a non-empty string that d32156 2 a32157 2 style the result as a single 'DisassemblerTextPart' with 'STYLE_TEXT' style (*note Disassembler Styling Parts::). d32159 2 a32160 2 The PARTS argument, if not 'None', is a non-empty sequence of 'DisassemblerPart' objects. Each part represents a small part d32163 2 a32164 2 displayed by GDB with full styling information (*note 'set style disassembler enabled': style_disassembler_enabled.). d32178 1 a32178 1 'DisassemblerPart' objects, the STRING property will still be d32180 1 a32180 1 'DisassemblerPart.string' values of each component part (*note d32185 1 a32185 1 'DisassemblerPart' objects. Each 'DisassemblerPart' object d32189 1 a32189 1 'set style disassembler enabled': d32193 1 a32193 1 than with a sequence of 'DisassemblerPart' objects, the PARTS d32196 1 a32196 1 'DisassemblerTextPart' object, the string of which will d32198 1 a32198 1 be 'STYLE_TEXT'. d32208 4 a32211 4 'builtin_disassemble' (*note builtin_disassemble::) and are returned within the 'DisassemblerResult' object, or can be created by calling the 'text_part' and 'address_part' methods on the 'DisassembleInfo' class (*note DisassembleInfo Class::). d32213 1 a32213 1 The 'DisassemblerPart' class has a single property: d32222 1 a32222 1 The 'DisassemblerTextPart' class represents a piece of the d32225 1 a32225 1 'DisassembleInfo.text_part' to create a new instance of this class d32229 1 a32229 1 'DisassemblerTextPart' has the following additional property: d32238 1 a32238 1 The 'DisassemblerAddressPart' class represents an absolute address d32240 2 a32241 2 'DisassemblerAddressPart' instead of a 'DisassemblerTextPart' with 'STYLE_ADDRESS' is preferred, GDB will display the address as both d32243 2 a32244 2 next to the address. Using 'DisassemblerAddressPart' also ensures that user settings such as 'set print max-symbolic-offset' are d32251 4 a32254 4 In this instruction the '0x401136 ' was generated from a single 'DisassemblerAddressPart'. The '0x401136' will be styled with 'STYLE_ADDRESS', and 'foo' will be styled with 'STYLE_SYMBOL'. The '<' and '>' will be styled as 'STYLE_TEXT'. d32257 1 a32257 1 'DisassemblerTextPart' with style 'STYLE_ADDRESS' can be used d32261 1 a32261 1 'DisassembleInfo.address_part' to create a new instance of this d32265 1 a32265 1 'DisassemblerAddressPart' has the following additional property: d32269 1 a32269 1 object's '__init__' method. d32279 1 a32279 1 'gdb.disassembler.STYLE_TEXT' d32285 1 a32285 1 'gdb.disassembler.STYLE_MNEMONIC' d32290 1 a32290 1 GDB styles text with this style using the 'disassembler mnemonic' d32293 1 a32293 1 'gdb.disassembler.STYLE_SUB_MNEMONIC' d32298 1 a32298 1 'STYLE_MNEMONIC'). d32304 3 a32306 3 The 'add' is the primary instruction mnemonic, and would be given style 'STYLE_MNEMONIC', while 'lsl' is the sub-mnemonic, and would be given the style 'STYLE_SUB_MNEMONIC'. d32308 1 a32308 1 GDB styles text with this style using the 'disassembler mnemonic' d32311 1 a32311 1 'gdb.disassembler.STYLE_ASSEMBLER_DIRECTIVE' d32318 2 a32319 2 In this case, the '.word' would be give the 'STYLE_ASSEMBLER_DIRECTIVE' style. An assembler directive is d32323 1 a32323 1 GDB styles text with this style using the 'disassembler mnemonic' d32326 1 a32326 1 'gdb.disassembler.STYLE_REGISTER' d32330 1 a32330 1 GDB styles text with this style using the 'disassembler register' d32333 1 a32333 1 'gdb.disassembler.STYLE_ADDRESS' d32337 2 a32338 2 When creating a 'DisassemblerTextPart' with this style, you should consider if a 'DisassemblerAddressPart' would be more appropriate. d32342 1 a32342 1 GDB styles text with this style using the 'disassembler address' d32345 1 a32345 1 'gdb.disassembler.STYLE_ADDRESS_OFFSET' d32359 1 a32359 1 GDB styles text with this style using the 'disassembler immediate' d32362 2 a32363 2 'gdb.disassembler.STYLE_IMMEDIATE' Use 'STYLE_IMMEDIATE' for any numerical values within a d32365 2 a32366 2 address offsets, or register numbers (The styles 'STYLE_ADDRESS', 'STYLE_ADDRESS_OFFSET', or 'STYLE_REGISTER' can be used in those d32369 1 a32369 1 GDB styles text with this style using the 'disassembler immediate' d32372 1 a32372 1 'gdb.disassembler.STYLE_SYMBOL' d32381 2 a32382 2 Here 'foo' is the name of a symbol, and should be given the 'STYLE_SYMBOL' style. d32385 1 a32385 1 automatically by the 'DisassemblerAddressPart' class (*note d32388 1 a32388 1 GDB styles text with this style using the 'disassembler symbol' d32391 1 a32391 1 'gdb.disassembler.STYLE_COMMENT_START' d32394 1 a32394 1 'DisassemblerTextPiece' to which they are applied, the comment d32398 1 a32398 1 This means that, after a 'STYLE_COMMENT_START' piece has been seen, d32402 1 a32402 1 GDB styles text with this style using the 'disassembler comment' d32405 1 a32405 1 The following functions are also contained in the 'gdb.disassembler' d32410 1 a32410 1 'gdb.disassembler.Disassembler' or 'None'. d32412 1 a32412 1 The optional ARCHITECTURE is either a string, or the value 'None'. d32414 1 a32414 1 known to GDB, as returned either from 'gdb.Architecture.name' d32416 1 a32416 1 'gdb.architecture_names' (*note gdb.architecture_names: d32420 1 a32420 1 ARCHITECTURE, or if ARCHITECTURE is 'None', then DISASSEMBLER will d32424 1 a32424 1 single global disassembler. Calling 'register_disassembler' for an d32429 1 a32429 1 If DISASSEMBLER is 'None' then any disassembler currently d32435 1 a32435 1 ARCHITECTURE set to 'None'). Only one disassembler is called to d32446 1 a32446 1 You can use the 'maint info python-disassemblers' command (*note d32453 1 a32453 1 sub-class, of 'DisassembleInfo'. d32456 3 a32458 3 'read_memory' method on INFO will be called. By sub-classing 'DisassembleInfo' and overriding the 'read_memory' method, it is possible to intercept calls to 'read_memory' from the builtin d32462 1 a32462 1 'DisassembleInfo.read_memory' raises a 'gdb.MemoryError', it is the d32470 1 a32470 1 'DisassemblerResult' is returned from 'builtin_disassemble', d32474 1 a32474 1 A 'MemoryError' will be raised if 'builtin_disassemble' is unable d32478 2 a32479 2 Any exception that is not a 'MemoryError', that is raised in a call to 'read_memory', will pass through 'builtin_disassemble', and be d32483 2 a32484 2 fail for reasons that are not covered by 'MemoryError'. In these cases, a 'GdbError' will be raised. The contents of the exception d32490 1 a32490 1 '## Comment', to each line of disassembly output: d32504 2 a32505 2 The following example creates a sub-class of 'DisassembleInfo' in order to intercept the 'read_memory' calls, within 'read_memory' any d32557 3 a32559 3 object which has the 'name' and 'enabled' attributes, and implements the '__call__' method. When GDB encounters an objfile for which it is unable to find any debug information, it invokes the '__call__' method. d32562 1 a32562 1 The 'gdb.missing_debug' Module d32565 1 a32565 1 GDB comes with a 'gdb.missing_debug' module which contains the following d32570 1 a32570 1 'MissingDebugHandler' is a base class from which user-created d32572 2 a32573 2 from this class, so long as any user created handler has the 'name' and 'enabled' attributes, and implements the '__call__' method. d32578 2 a32579 2 characters '[-_a-zA-Z0-9]', creating a handler with an invalid name raises a 'ValueError' exception. d32582 2 a32583 2 Sub-classes must override the '__call__' method. The OBJFILE argument will be a 'gdb.Objfile', this is the objfile for d32586 1 a32586 1 The return value from the '__call__' method indicates what GDB d32589 1 a32589 1 * 'None' d32594 1 a32594 1 * 'True' d32610 1 a32610 1 * 'False' d32618 1 a32618 1 * A string d32625 2 a32626 2 Invoking the '__call__' method from this base class will raise a 'NotImplementedError' exception. d32630 1 a32630 1 handler passed to the '__init__' method. d32633 2 a32634 2 A modifiable attribute containing a boolean; when 'True', the handler is enabled, and will be used by GDB. When 'False', d32638 1 a32638 1 replace='False') d32641 1 a32641 1 HANDLER is an instance of a sub-class of 'MissingDebugHandler', or d32643 1 a32643 1 methods as 'MissingDebugHandler'. d32646 2 a32647 2 be either a 'gdb.Progspace' (*note Progspaces In Python::) or 'None', in which case the handler is registered globally. The d32651 1 a32651 1 name raises an exception unless REPLACE is 'True', in which case d32657 1 a32657 1 returns a value other than 'None', no further handlers are called d32666 1 a32666 1 When a new object file is read (for example, due to the 'file' command, d32668 2 a32669 2 Python support scripts in several ways: 'OBJFILE-gdb.py' and '.debug_gdb_scripts' section. *Note Auto-loading extensions::. d32677 1 a32677 1 'set auto-load python-scripts [on|off]' d32680 1 a32680 1 'show auto-load python-scripts' d32683 1 a32683 1 'info auto-load python-scripts [REGEXP]' d32687 1 a32687 1 the '.debug_gdb_scripts' section and were either not found (*note d32689 1 a32689 1 'auto-load safe-path' rejection (*note Auto-loading::). This is d32705 2 a32706 2 When reading an auto-loaded file or script, GDB sets the "current objfile". This is available via the 'gdb.current_objfile' function d32733 3 a32735 3 'PrettyPrinter (NAME, SUBPRINTERS=None)' This class specifies the API that makes 'info pretty-printer', 'enable pretty-printer' and 'disable pretty-printer' work. d32738 1 a32738 1 'SubPrettyPrinter (NAME)' d32742 1 a32742 1 'RegexpCollectionPrettyPrinter (NAME)' d32747 3 a32749 3 'FlagEnumerationPrinter (NAME)' A pretty-printer which handles printing of 'enum' values. Unlike GDB's built-in 'enum' printing, this printer attempts to work d32752 1 a32752 1 the name of the 'enum' type to look up. d32754 1 a32754 1 'register_pretty_printer (OBJ, PRINTER, REPLACE=False)' d32756 2 a32757 2 is 'True' then any existing copy of the printer is replaced. Otherwise a 'RuntimeError' exception is raised if a printer with d32767 1 a32767 1 'gdb.Type' objects. d32769 1 a32769 1 'get_basic_type (TYPE)' d32788 2 a32789 2 'has_field (TYPE, FIELD)' Return 'True' if TYPE, assumed to be a type with fields (e.g., a d32792 2 a32793 2 'make_enum_dict (ENUM_TYPE)' Return a Python 'dictionary' type produced from ENUM_TYPE. d32795 1 a32795 1 'deep_items (TYPE)' d32797 2 a32798 2 'gdb.Type.iteritems' method, except that the iterator returned by 'deep_items' will recursively traverse anonymous struct or union d32818 1 a32818 1 'get_type_recognizers ()' d32823 1 a32823 1 'apply_type_recognizers (recognizers, type_obj)' d32826 1 a32826 1 Otherwise, return 'None'. This is called by GDB during the d32829 1 a32829 1 'register_type_printer (locus, printer)' d32832 3 a32834 3 argument is either a 'gdb.Objfile', in which case the printer is registered with that objfile; a 'gdb.Progspace', in which case the printer is registered with that progspace; or 'None', in which case d32837 1 a32837 1 'TypePrinter' d32854 1 a32854 1 'substitute_prompt (STRING)' d32861 1 a32861 1 '\\' d32863 1 a32863 1 '\e' d32865 1 a32865 1 '\f' d32868 1 a32868 1 '\n' d32870 1 a32870 1 '\p' d32873 1 a32873 1 '\r' d32875 1 a32875 1 '\t' d32878 1 a32878 1 '\v' d32880 1 a32880 1 '\w' d32882 1 a32882 1 '\[' d32888 1 a32888 1 '\]' d32907 1 a32907 1 is available only if GDB was configured using '--with-guile'. d32933 1 a32933 1 'DATA-DIRECTORY/guile', where DATA-DIRECTORY is the data directory as d32935 1 a32935 1 as the "guile directory", is automatically added to the Guile Search d32947 5 a32951 5 'guile-repl' 'gr' The 'guile-repl' command can be used to start an interactive Guile prompt or "repl". To return to GDB, type ',q' or the 'EOF' character (e.g., 'Ctrl-D' on an empty prompt). These commands do d32954 3 a32956 3 'guile [SCHEME-EXPRESSION]' 'gu [SCHEME-EXPRESSION]' The 'guile' command can be used to evaluate a Scheme expression. d32970 3 a32972 3 If you do not provide an argument to 'guile', it will act as a multi-line command, like 'define'. In this case, the Guile script is made up of subsequent command lines, given after the 'guile' d32974 1 a32974 1 'end'. For example: d32985 2 a32986 2 'source script-name' The script name must end with '.scm' and GDB must be configured to d32988 1 a32988 1 'script-extension' setting. *Note Extending GDB: Extending GDB. d32990 2 a32991 2 'guile (load "script-name")' This method uses the 'load' Guile function. It takes a string d33003 1 a33003 1 'help guile', or by issuing the command ',help' from an interactive d33005 2 a33006 2 doc strings which can be obtained with ',describe PROCEDURE-NAME' or ',d PROCEDURE-NAME' from the Guile interactive prompt. d33042 2 a33043 2 At startup, GDB overrides Guile's 'current-output-port' and 'current-error-port' to print using GDB's output-paging streams. A d33046 1 a33046 1 Guile 'signal' exception is thrown with value 'SIGINT'. d33050 2 a33051 2 evaluations in Guile and in GDB are counted separately, '$1' in Guile is not the same value as '$1' in GDB. d33060 2 a33061 2 * GDB installs handlers for 'SIGCHLD' and 'SIGINT'. Guile code must not override these, or even change the options using 'sigaction'. d33064 1 a33064 1 common for GUI toolkits to install a 'SIGCHLD' handler. d33066 1 a33066 1 * GDB takes care to mark its internal file descriptors as d33073 1 a33073 1 GDB introduces a new Guile module, named 'gdb'. All methods and d33075 1 a33075 1 automatically 'import' the 'gdb' module, scripts must do this d33077 1 a33077 1 GDB leaves the choice of how the 'gdb' module is imported to the user. d33086 1 a33086 1 'gdb:' as a prefix to all module functions and variables. d33088 2 a33089 2 The rest of this manual assumes the 'gdb' module has been imported without any prefix. See the Guile documentation for 'use-modules' for d33102 1 a33102 1 The '(gdb)' module provides these basic Guile functions. d33112 1 a33112 1 be a boolean value. If omitted, it defaults to '#f'. d33116 3 a33118 3 If the TO-STRING parameter is '#t', then output will be collected by 'execute' and returned as a string. The default is '#f', in which case the return value is unspecified. If TO-STRING is '#t', d33130 1 a33130 1 doesn't exist in the value history, a 'gdb:error' exception will be d33134 1 a33134 1 of '' (*note Values From Inferior In Guile::). d33136 1 a33136 1 _Note:_ GDB's value history is independent of Guile's. '$1' in d33138 1 a33138 1 from GDB's command line and '$1' from Guile's history contains the d33142 1 a33142 1 Append VALUE, an instance of '', to GDB's value history. d33151 1 a33151 1 it, and return the result as a ''. The EXPRESSION must d33158 1 a33158 1 convenience variable (*note Convenience Vars::) as a ''. d33182 1 a33182 1 string passed to '--host' when GDB was configured. d33186 1 a33186 1 string passed to '--target' when GDB was configured. d33194 1 a33194 1 The values exposed by GDB to Guile are known as "GDB objects". There d33199 1 a33199 1 Return the kind of the GDB object, e.g., '', as a d33204 1 a33204 1 '' d33207 1 a33207 1 '' d33210 1 a33210 1 '' d33213 1 a33213 1 '' d33216 1 a33216 1 '' d33219 1 a33219 1 '' d33222 1 a33222 1 '' d33225 1 a33225 1 '' d33228 1 a33228 1 '' d33231 1 a33231 1 '' d33234 1 a33234 1 '' d33237 1 a33237 1 '' d33240 1 a33240 1 '' d33243 1 a33243 1 '' d33246 1 a33246 1 '' d33249 1 a33249 1 '' d33252 1 a33252 1 '' d33255 1 a33255 1 '' d33258 1 a33258 1 '' d33261 1 a33261 1 '' d33265 1 a33265 1 function 'eq?' may be applied to them. d33267 9 a33275 9 '' '' '' '' '' '' '' '' '' d33283 1 a33283 1 When executing the 'guile' command, Guile exceptions uncaught within the d33285 3 a33287 3 If the command that called 'guile' does not handle the error, GDB will terminate it and report the error according to the setting of the 'guile print-stack' parameter. d33289 1 a33289 1 The 'guile print-stack' parameter has three settings: d33291 1 a33291 1 'none' d33294 1 a33294 1 'message' d33304 1 a33304 1 'full' d33339 1 a33339 1 exceptions like 'wrong-type-arg' and 'out-of-range'. d33341 2 a33342 2 User interrupt (via 'C-c' or by typing 'q' at a pagination prompt) is translated to a Guile 'signal' exception with value 'SIGINT'. d33346 1 a33346 1 'gdb:error' d33349 1 a33349 1 'gdb:invalid-object' d33352 1 a33352 1 '' object becomes invalid if the user deletes it d33357 1 a33357 1 'gdb:memory-error' d33361 1 a33361 1 'gdb:pp-type-error' d33366 1 a33366 1 '(gdb)' module. d33369 1 a33369 1 Return a '' object given by its KEY and ARGS, which d33374 2 a33375 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d33378 1 a33378 1 Return the ARGS field of a '' object. d33381 1 a33381 1 Return the ARGS field of a '' object. d33390 1 a33390 1 type ''. GDB uses this object for its internal bookkeeping d33393 1 a33393 1 GDB does not memoize '' objects. 'make-value' always d33401 2 a33402 2 A '' that represents a function can be executed via inferior function call with 'value-call'. Any arguments provided to the d33406 1 a33406 1 For example, 'some-val' is a '' instance representing a d33412 1 a33412 1 Any values returned from a function call are '' objects. d33416 2 a33417 2 the value's data type. For example, '(+ (parse-and-eval "int_variable") 2)' does not work. And inferior values that are structures or instances d33419 1 a33419 1 'value-field' must be used. d33421 1 a33421 1 The following value-related procedures are provided by the '(gdb)' d33425 2 a33426 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d33429 1 a33429 1 Many Scheme values can be converted directly to a '' d33439 1 a33439 1 'make-value' is not specified: d33446 3 a33448 3 A Scheme integer is converted to the first of a C 'int', 'unsigned int', 'long', 'unsigned long', 'long long' or 'unsigned long long' type for the current architecture that d33452 1 a33452 1 integer an 'out-of-range' exception is thrown. d33455 1 a33455 1 A Scheme real is converted to the C 'double' type for the d33463 1 a33463 1 Guile's 'SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE' conversion d33467 1 a33467 1 a 'wrong-type-arg' exception is thrown. d33469 3 a33471 3 '' If VALUE is a '' object (*note Lazy Strings In Guile::), then the 'lazy-string->value' procedure is d33475 1 a33475 1 a 'wrong-type-arg' exception is thrown. d33480 1 a33480 1 the result is essentially created by using 'memcpy'. d33483 1 a33483 1 result is an array of type 'uint8' of the same length. d33486 2 a33487 2 Return '#t' if the compiler optimized out VALUE, thus it is not available for fetching from the inferior. Otherwise return '#f'. d33490 2 a33491 2 If VALUE is addressable, returns a '' object representing the address. Otherwise, '#f' is returned. d33494 1 a33494 1 Return the type of VALUE as a '' object (*note Types In d33509 1 a33509 1 just return the static type of the value as in 'ptype foo'. *Note d33513 1 a33513 1 Return a new instance of '' that is the result of d33515 1 a33515 1 '' object. If the cast cannot be performed for some d33519 1 a33519 1 Like 'value-cast', but works as if the C++ 'dynamic_cast' operator d33523 1 a33523 1 Like 'value-cast', but works as if the C++ 'reinterpret_cast' d33527 1 a33527 1 For pointer data types, this method returns a new '' d33529 1 a33529 1 example, if 'foo' is a C pointer to an 'int', declared in your C d33534 2 a33535 2 then you can use the corresponding '' to access what 'foo' points to like this: d33539 2 a33540 2 The result 'bar' will be a '' object holding the value pointed to by 'foo'. d33542 2 a33543 2 A similar function 'value-referenced-value' exists which also returns '' objects corresponding to the values pointed d33545 5 a33549 5 reference values). However, the behavior of 'value-dereference' differs from 'value-referenced-value' by the fact that the behavior of 'value-dereference' is identical to applying the C unary operator '*' on a given value. For example, consider a reference to a pointer 'ptrref', declared in your C++ program as d33557 6 a33562 6 Though 'ptrref' is a reference value, one can apply the method 'value-dereference' to the '' object corresponding to it and obtain a '' which is identical to that corresponding to 'val'. However, if you apply the method 'value-referenced-value', the result would be a '' object identical to that corresponding to 'ptr'. d33568 4 a33571 4 The '' object 'scm-val' is identical to that corresponding to 'val', and 'scm-ptr' is identical to that corresponding to 'ptr'. In general, 'value-dereference' can be applied whenever the C unary operator '*' can be applied to the d33573 1 a33573 1 'value-dereference' and 'value-referenced-value' is allowed, the d33576 2 a33577 2 '' objects corresponding to pointers ('' objects with type code 'TYPE_CODE_PTR') in a C/C++ program. d33581 1 a33581 1 '' object corresponding to the value referenced by the d33583 1 a33583 1 'value-dereference' and 'value-referenced-value' produce identical d33585 2 a33586 2 'value-dereference' cannot get the values referenced by reference values. For example, consider a reference to an 'int', declared in d33592 4 a33595 4 then applying 'value-dereference' to the '' object corresponding to 'ref' will result in an error, while applying 'value-referenced-value' will result in a '' object identical to that corresponding to 'val'. d33601 2 a33602 2 The '' object 'scm-val' is identical to that corresponding to 'val'. d33605 2 a33606 2 Return a new '' object which is a reference to the value encapsulated by '' object VALUE. d33609 2 a33610 2 Return a new '' object which is an rvalue reference to the value encapsulated by '' object VALUE. d33613 2 a33614 2 Return a new '' object which is a 'const' version of '' object VALUE. d33617 1 a33617 1 Return field FIELD-NAME from '' object VALUE. d33621 1 a33621 1 must be a subscriptable '' object. d33630 1 a33630 1 Return the Scheme boolean representing '' VALUE. The d33634 1 a33634 1 Return the Scheme integer representing '' VALUE. The d33638 1 a33638 1 Return the Scheme real number representing '' VALUE. d33642 1 a33642 1 Return a Scheme bytevector with the raw contents of '' d33659 2 a33660 2 pointer to or an array of characters or ints of type 'wchar_t', 'char16_t', or 'char32_t'. d33663 2 a33664 2 naming the encoding of the string in the '', such as '"ascii"', '"iso-8859-6"' or '"utf-8"'. It accepts the same d33666 1 a33666 1 'scm_from_stringn' function, and the Guile codec machinery will be d33668 1 a33668 1 ENCODING is the empty string, then either the 'target-charset' d33673 3 a33675 3 The optional ERRORS argument is one of '#f', 'error' or 'substitute'. 'error' and 'substitute' must be symbols. If ERRORS is not specified, or if its value is '#f', then the default d33677 1 a33677 1 'set-port-conversion-strategy!'. If the value is ''error' then an d33679 1 a33679 1 is ''substitute' then any conversion error is replaced with d33684 1 a33684 1 Scheme integer and not a '' integer. d33688 2 a33689 2 If this '' represents a string, then this method converts VALUE to a '' integer. d33712 2 a33713 2 Return '#t' if VALUE has not yet been fetched from the inferior. Otherwise return '#f'. GDB does not fetch values until necessary, d33718 2 a33719 2 The value of 'somevar' is not fetched at this time. It will be fetched when the value is needed, or when the 'fetch-lazy' d33723 2 a33724 2 Return a '' that will be lazily fetched from the target. The object of type '' whose value to fetch is specified d33729 1 a33729 1 If VALUE is a lazy value ('(value-lazy? value)' is '#t'), then the d33738 1 a33738 1 Return the string representation (print form) of '' d33747 2 a33748 2 The '(gdb)' module provides several functions for performing arithmetic on '' objects. The arithmetic is performed as if it were d33804 1 a33804 1 Scheme does not provide a 'not-equal' function, and thus Guile d33813 1 a33813 1 GDB represents types from the inferior in objects of type ''. d33815 1 a33815 1 The following type-related procedures are provided by the '(gdb)' d33819 2 a33820 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d33825 1 a33825 1 If BLOCK is given, it is an object of type '', and NAME d33829 1 a33829 1 Ordinarily, this function will return an instance of ''. d33834 1 a33834 1 'TYPE_CODE_' constants defined below. d33838 2 a33839 2 'struct', 'union', or 'enum' in C and C++; not all languages have this concept. If this type has no tag name, then '#f' is returned. d33842 1 a33842 1 Return the name of TYPE. If this type has no name, then '#f' is d33847 2 a33848 2 anonymous types. For example, for an anonymous C struct '"struct {...}"' is returned. d33851 2 a33852 2 Return the size of this type, in target 'char' units. Usually, a target's 'char' type will be an 8-bit byte. However, on some d33856 1 a33856 1 Return a new '' that represents the real type of TYPE, d33860 1 a33860 1 Return a new '' object which represents an array of this d33868 1 a33868 1 Return a new '' object which represents a vector of this d33875 1 a33875 1 The difference between an 'array' and a 'vector' is that arrays d33881 1 a33881 1 Return a new '' object which represents a pointer to d33889 1 a33889 1 Return a new '' object which represents a reference to d33893 1 a33893 1 Return a new '' object which represents the target type d33907 2 a33908 2 Return a new '' object which represents a 'const'-qualified variant of TYPE. d33911 2 a33912 2 Return a new '' object which represents a 'volatile'-qualified variant of TYPE. d33915 3 a33917 3 Return a new '' object which represents an unqualified variant of TYPE. That is, the result is neither 'const' nor 'volatile'. d33920 1 a33920 1 Return the number of fields of '' TYPE. d33924 1 a33924 1 types, 'fields' has the usual meaning. Range types have two d33938 1 a33938 1 type ''. *Note Fields of a type in Guile::. If the d33942 2 a33943 2 For example, if 'some-type' is a '' instance holding a structure type, you can access its 'foo' field with: d33947 1 a33947 1 'bar' will be a '' object. d33950 2 a33951 2 Return '#t' if '' TYPE has field named NAME. Otherwise return '#f'. d33955 1 a33955 1 defined in the '(gdb)' module: d33957 1 a33957 1 'TYPE_CODE_PTR' d33960 1 a33960 1 'TYPE_CODE_ARRAY' d33963 1 a33963 1 'TYPE_CODE_STRUCT' d33966 1 a33966 1 'TYPE_CODE_UNION' d33969 1 a33969 1 'TYPE_CODE_ENUM' d33972 1 a33972 1 'TYPE_CODE_FLAGS' d33975 1 a33975 1 'TYPE_CODE_FUNC' d33978 1 a33978 1 'TYPE_CODE_INT' d33981 1 a33981 1 'TYPE_CODE_FLT' d33984 2 a33985 2 'TYPE_CODE_VOID' The special type 'void'. d33987 1 a33987 1 'TYPE_CODE_SET' d33990 1 a33990 1 'TYPE_CODE_RANGE' d33993 1 a33993 1 'TYPE_CODE_STRING' d33998 1 a33998 1 'TYPE_CODE_BITSTRING' d34001 1 a34001 1 'TYPE_CODE_ERROR' d34004 1 a34004 1 'TYPE_CODE_METHOD' d34007 1 a34007 1 'TYPE_CODE_METHODPTR' d34010 1 a34010 1 'TYPE_CODE_MEMBERPTR' d34013 1 a34013 1 'TYPE_CODE_REF' d34016 1 a34016 1 'TYPE_CODE_RVALUE_REF' d34019 1 a34019 1 'TYPE_CODE_CHAR' d34022 1 a34022 1 'TYPE_CODE_BOOL' d34025 1 a34025 1 'TYPE_CODE_COMPLEX' d34028 1 a34028 1 'TYPE_CODE_TYPEDEF' d34031 1 a34031 1 'TYPE_CODE_NAMESPACE' d34034 1 a34034 1 'TYPE_CODE_DECFLOAT' d34037 1 a34037 1 'TYPE_CODE_INTERNAL_FUNCTION' d34041 1 a34041 1 'gdb.TYPE_CODE_XMETHOD' d34045 1 a34045 1 'gdb.TYPE_CODE_FIXED_POINT' d34048 1 a34048 1 'gdb.TYPE_CODE_NAMESPACE' d34051 1 a34051 1 Further support for types is provided in the '(gdb types)' Guile d34054 1 a34054 1 Each field is represented as an object of type ''. d34056 1 a34056 1 The following field-related procedures are provided by the '(gdb)' d34060 2 a34061 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d34064 1 a34064 1 Return the name of the field, or '#f' for anonymous fields. d34068 1 a34068 1 '', but it can be '#f' in some situations. d34071 1 a34071 1 Return the enum value represented by '' FIELD. d34074 2 a34075 2 Return the bit position of '' FIELD. This attribute is not available for 'static' fields (as in C++). d34079 1 a34079 1 '' FIELD in bits. Otherwise, zero is returned; in which d34083 2 a34084 2 Return '#t' if the field is artificial, usually meaning that it was provided by the compiler and not the user. Otherwise return '#f'. d34087 2 a34088 2 Return '#t' if the field represents a base class of a C++ structure. Otherwise return '#f'. d34100 1 a34100 1 'make-pretty-printer'. d34103 1 a34103 1 '(gdb)' module: d34106 1 a34106 1 Return a '' object named NAME. d34112 1 a34112 1 Otherwise LOOKUP-FUNCTION returns '#f'. d34115 2 a34116 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d34119 1 a34119 1 Return '#t' if PRETTY-PRINTER is enabled. Otherwise return '#f'. d34134 1 a34134 1 Return an object of type ''. d34138 1 a34138 1 'display-hint' d34141 1 a34141 1 must be a string or '#f' (meaning there is no hint). Several d34144 1 a34144 1 'array' d34146 2 a34147 2 The CLI uses this to respect parameters such as 'set print elements' and 'set print array'. d34149 1 a34149 1 'map' d34154 1 a34154 1 'string' d34156 1 a34156 1 If the printer's 'to-string' function returns a Guile d34160 2 a34161 2 possibly escaping some characters, respecting 'set print elements', and the like. d34163 1 a34163 1 'to-string' d34165 1 a34165 1 '' object, or '#f'. d34167 1 a34167 1 When printing from the CLI, if the 'to-string' method exists, d34169 1 a34169 1 'children'. Exactly how this formatting is done is dependent d34172 2 a34173 2 Settings::), the CLI may print just the result of 'to-string' in a stack trace, omitting the result of 'children'. d34178 1 a34178 1 '', then GDB prints this value. This may result in d34182 1 a34182 1 convertible to a '', then GDB performs the d34186 1 a34186 1 to ''; other types are not. d34188 1 a34188 1 Finally, if this method returns '#f' then no further d34195 1 a34195 1 TO-STRING may also be '#f' in which case it is left to d34198 1 a34198 1 'children' d34200 1 a34200 1 '' object, or '#f'. d34211 1 a34211 1 If CHILDREN is '#f', GDB will act as though the value has no d34214 2 a34215 2 Children may be hidden from display based on the value of 'set print max-depth' (*note Print Settings::). d34218 1 a34218 1 pretty-printer for a '': d34221 1 a34221 1 This function takes a '' object as an argument. If a d34223 1 a34223 1 such printer exists, then this returns '#f'. d34233 2 a34234 2 * Per-objfile list of pretty-printers (*note Objfiles In Guile::). * Per-progspace list of pretty-printers (*note Progspaces In d34236 1 a34236 1 * The global list of pretty-printers (*note Guile Pretty Printing d34241 8 a34248 8 lookup function returns a non-'#f' value or when the list is exhausted. Lookup functions must return either a '' object or '#f'. Otherwise an exception is thrown. GDB first checks the result of 'objfile-pretty-printers' of each '' in the current program space and iteratively calls each enabled lookup function in the list for that '' until a non-'#f' object is returned. If no pretty-printer is found in the d34250 2 a34251 2 'progspace-pretty-printers' of the current program space, calling each enabled function until a non-'#f' object is returned. After these lists d34253 2 a34254 2 with 'pretty-printers', again calling each enabled function until a non-'#f' object is returned. d34259 1 a34259 1 '' object is returned. d34267 1 a34267 1 For example, if 'print frame-arguments' is on, a backtrace can become d34271 1 a34271 1 'set-pretty-printer-enabled!'. *Note Guile Pretty Printing API::. d34282 1 a34282 1 Here is an example showing how a 'std::string' printer might be d34310 1 a34310 1 object. If not, it returns '#f'. d34321 1 a34321 1 An ideal auto-load file will consist solely of 'import's of your printer d34334 2 a34335 2 To continue the 'my::string' example, this code might appear in '(my-project my-library v1)': d34353 1 a34353 1 multiple data types, then its "subprinters" are the printers for the d34356 1 a34356 1 The '(gdb printing)' module provides a formal way of solving this d34386 1 a34386 1 '(gdb printing)' module. Instead a function is provided to build up the d34403 1 a34403 1 corresponding output of 'info pretty-printer': d34418 2 a34419 2 is created with the 'make-command' Guile function, and added to GDB with the 'register-command!' Guile function. This two-step approach is taken d34421 1 a34421 1 'make-command'. d34424 1 a34424 1 consist of multiple lines and are terminated with 'end'. d34435 1 a34435 1 The result is the '' object representing the command. d34437 1 a34437 1 with 'register-command!'. d34442 1 a34442 1 and FROM-TTY. The argument SELF is the '' object d34449 1 a34449 1 into a GDB 'error' call. Otherwise, the return value is ignored. d34451 1 a34451 1 The argument COMMAND-CLASS is one of the 'COMMAND_' constants d34453 1 a34453 1 command in the help system. The default is 'COMMAND_NONE'. d34455 1 a34455 1 The argument COMPLETER is either '#f', one of the 'COMPLETE_' d34458 1 a34458 1 not provided or if the value is '#f', then no completion is d34470 1 a34470 1 Add COMMAND, a '' object, to GDB's list of commands. d34475 2 a34476 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d34481 2 a34482 2 by invoking the 'dont-repeat' function. This is similar to the user command 'dont-repeat', see *note dont-repeat: Define. d34493 1 a34493 1 Throw a 'gdb:user-error' exception. The argument MESSAGE is the d34495 1 a34495 1 'format' Scheme function. *Note (guile)Formatted Output::. The d34512 2 a34513 2 If the COMPLETER option to 'make-command' is a procedure, it takes three arguments: SELF which is the '' object, and TEXT d34521 1 a34521 1 'complete' command (*note complete: Help.). d34525 1 a34525 1 * If the return value is a list, the contents of the list are d34532 1 a34532 1 * If the return value is a '' object, it is d34534 1 a34534 1 'completer-procedure' to ensure that the results actually do d34538 1 a34538 1 * All other results are treated as though there were no d34546 1 a34546 1 constants defined in the 'gdb' module: d34548 1 a34548 1 'COMMAND_NONE' d34553 1 a34553 1 'COMMAND_RUNNING' d34555 2 a34556 2 'start', 'step', and 'continue' are in this category. Type 'help running' at the GDB prompt to see a list of commands in this d34559 3 a34561 3 'COMMAND_DATA' The command is related to data or variables. For example, 'call', 'find', and 'print' are in this category. Type 'help data' at the d34564 1 a34564 1 'COMMAND_STACK' d34566 2 a34567 2 'backtrace', 'frame', and 'return' are in this category. Type 'help stack' at the GDB prompt to see a list of commands in this d34570 3 a34572 3 'COMMAND_FILES' This class is used for file-related commands. For example, 'file', 'list' and 'section' are in this category. Type 'help files' at d34575 1 a34575 1 'COMMAND_SUPPORT' d34578 2 a34579 2 not related to the state of the inferior. For example, 'help', 'make', and 'shell' are in this category. Type 'help support' at d34582 4 a34585 4 'COMMAND_STATUS' The command is an 'info'-related command, that is, related to the state of GDB itself. For example, 'info', 'macro', and 'show' are in this category. Type 'help status' at the GDB prompt to see a d34588 4 a34591 4 'COMMAND_BREAKPOINTS' The command has to do with breakpoints. For example, 'break', 'clear', and 'delete' are in this category. Type 'help breakpoints' at the GDB prompt to see a list of commands in this d34594 4 a34597 4 'COMMAND_TRACEPOINTS' The command has to do with tracepoints. For example, 'trace', 'actions', and 'tfind' are in this category. Type 'help tracepoints' at the GDB prompt to see a list of commands in this d34600 1 a34600 1 'COMMAND_USER' d34602 2 a34603 2 typically does not fit in one of the other categories. Type 'help user-defined' at the GDB prompt to see a list of commands in this d34606 1 a34606 1 'COMMAND_OBSCURE' d34608 2 a34609 2 general interest to users. For example, 'checkpoint', 'fork', and 'stop' are in this category. Type 'help obscure' at the GDB prompt d34612 4 a34615 4 'COMMAND_MAINTENANCE' The command is only useful to GDB maintainers. The 'maintenance' and 'flushregs' commands are in this category. Type 'help internals' at the GDB prompt to see a list of commands in this d34620 2 a34621 2 the 'completer' procedure. These predefined completion constants are all defined in the 'gdb' module: d34623 1 a34623 1 'COMPLETE_NONE' d34626 1 a34626 1 'COMPLETE_FILENAME' d34629 1 a34629 1 'COMPLETE_LOCATION' d34633 1 a34633 1 'COMPLETE_COMMAND' d34637 1 a34637 1 'COMPLETE_SYMBOL' d34641 1 a34641 1 'COMPLETE_EXPRESSION' d34664 1 a34664 1 You can implement new GDB "parameters" using Guile (1). d34667 1 a34667 1 Two examples are: 'set follow-fork' and 'set charset'. Setting these d34672 2 a34673 2 A new parameter is defined with the 'make-parameter' Guile function, and added to GDB with the 'register-parameter!' Guile function. This d34675 1 a34675 1 parameter to GDB from 'make-parameter'. d34677 1 a34677 1 Parameters are exposed to the user via the 'set' and 'show' commands. d34690 3 a34692 3 the 'set print' set of parameters. If NAME is 'print foo', then 'print' will be searched as the prefix parameter. In this case the parameter can subsequently be accessed in GDB as 'set print foo'. d34696 1 a34696 1 The result is the '' object representing the d34698 1 a34698 1 registered with GDB with 'register-parameter!'. d34702 1 a34702 1 The argument COMMAND-CLASS should be one of the 'COMMAND_' d34705 1 a34705 1 'COMMAND_NONE'. d34707 1 a34707 1 The argument PARAMETER-TYPE should be one of the 'PARAM_' constants d34710 1 a34710 1 completion. The default is 'PARAM_BOOLEAN'. d34712 1 a34712 1 If PARAMETER-TYPE is 'PARAM_ENUM', then ENUM-LIST must be a list of d34716 1 a34716 1 If PARAMETER-TYPE is not 'PARAM_ENUM', then the presence of d34720 1 a34720 1 the '' object representing the parameter. GDB will d34722 1 a34722 1 the 'set' API (for example, 'set foo off'). The value of the d34727 1 a34727 1 function should return '""'. A non-empty string result should d34731 1 a34731 1 is the '' object representing the parameter, and d34733 2 a34734 2 GDB will call this function when a PARAMETER's 'show' API has been invoked (for example, 'show foo'). This function must return a d34741 1 a34741 1 The argument SET-DOC is the help text for this parameter's 'set' d34744 1 a34744 1 The argument SHOW-DOC is the help text for this parameter's 'show' d34749 1 a34749 1 '' object and its result is used as the initial d34754 1 a34754 1 Add PARAMETER, a '' object, to GDB's list of d34759 2 a34760 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d34764 1 a34764 1 '' object or a string naming the parameter. d34768 1 a34768 1 must be an object of type ''. GDB does validation d34772 1 a34772 1 available types are represented by constants defined in the 'gdb' d34775 3 a34777 3 'PARAM_BOOLEAN' The value is a plain boolean. The Guile boolean values, '#t' and '#f' are the only valid values. d34779 2 a34780 2 'PARAM_AUTO_BOOLEAN' The value has three possible states: true, false, and 'auto'. In d34782 1 a34782 1 'auto' is represented using '#:auto'. d34784 3 a34786 3 'PARAM_UINTEGER' The value is an unsigned integer. The value of '#:unlimited' should be interpreted to mean "unlimited", and the value of '0' is d34789 1 a34789 1 'PARAM_ZINTEGER' d34792 1 a34792 1 'PARAM_ZUINTEGER' d34795 3 a34797 3 'PARAM_ZUINTEGER_UNLIMITED' The value is an integer in the range '[0, INT_MAX]'. The value of '#:unlimited' means "unlimited", the value of '-1' is reserved and d34800 1 a34800 1 'PARAM_STRING' d34802 1 a34802 1 escape sequences, such as '\t', '\f', and octal escapes, are d34806 1 a34806 1 'PARAM_STRING_NOESCAPE' d34810 2 a34811 2 'PARAM_OPTIONAL_FILENAME' The value is a either a filename (a string), or '#f'. d34813 1 a34813 1 'PARAM_FILENAME' d34815 1 a34815 1 'PARAM_STRING_NOESCAPE', but uses file names for completion. d34817 1 a34817 1 'PARAM_ENUM' d34832 1 a34832 1 A program space, or "progspace", represents a symbolic view of an d34837 1 a34837 1 Each progspace is represented by an instance of the '' d34841 1 a34841 1 '(gdb)' module: d34844 2 a34845 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d34848 2 a34849 2 Return '#t' if PROGSPACE is valid, '#f' if not. A '' object can become invalid if the program it d34855 1 a34855 1 '#f'. *Note Inferiors Connections and Programs::. d34862 3 a34864 3 the name of the file passed as the argument to the 'file' or 'symbol-file' commands. If the program space does not have an associated file name, then '#f' is returned. This occurs, for d34867 1 a34867 1 A 'gdb:invalid-object-error' exception is thrown if PROGSPACE is d34873 1 a34873 1 ''. *Note Objfiles In Guile::. d34875 1 a34875 1 A 'gdb:invalid-object-error' exception is thrown if PROGSPACE is d34880 1 a34880 1 an object of type ''. *Note Guile Pretty d34885 1 a34885 1 Set the list of registered '' objects for d34899 1 a34899 1 "objfiles". d34901 1 a34901 1 Each objfile is represented as an object of type ''. d34903 1 a34903 1 The following objfile-related procedures are provided by the '(gdb)' d34907 2 a34908 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d34911 1 a34911 1 Return '#t' if OBJFILE is valid, '#f' if not. A '' d34913 1 a34913 1 loaded in GDB any longer. All other '' procedures d34922 1 a34922 1 Return the '' that this object file lives in. *Note d34926 1 a34926 1 Return the list of registered '' objects for d34930 1 a34930 1 Set the list of registered '' objects for d34932 1 a34932 1 '' objects. *Note Guile Pretty Printing API::, d34939 1 a34939 1 objfile, this function returns '#f'. d34951 2 a34952 2 (*note Stack frames: Frames.). The '' class represents a frame in the stack. A '' object is only valid while its d34954 1 a34954 1 an invalid frame object, GDB will throw a 'gdb:invalid-object' exception d34957 2 a34958 2 Two '' objects can be compared for equality with the 'equal?' function, like: d34963 1 a34963 1 The following frame-related procedures are provided by the '(gdb)' d34967 2 a34968 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d34971 1 a34971 1 Returns '#t' if FRAME is valid, '#f' if not. A frame object can d34973 1 a34973 1 the inferior. All '' procedures will throw an exception d34977 1 a34977 1 Return the function name of FRAME, or '#f' if it can't be obtained. d34980 1 a34980 1 Return the '' object corresponding to FRAME's d34986 1 a34986 1 'NORMAL_FRAME' d34989 1 a34989 1 'DUMMY_FRAME' d34993 1 a34993 1 'INLINE_FRAME' d34995 1 a34995 1 inlined into a 'NORMAL_FRAME' that is older than this one. d34997 1 a34997 1 'TAILCALL_FRAME' d35000 1 a35000 1 'SIGTRAMP_FRAME' d35004 1 a35004 1 'ARCH_FRAME' d35007 2 a35008 2 'SENTINEL_FRAME' This is like 'NORMAL_FRAME', but it is only used for the d35014 1 a35014 1 'unwind-stop-reason-string' to convert the value returned by this d35017 1 a35017 1 'FRAME_UNWIND_NO_REASON' d35020 1 a35020 1 'FRAME_UNWIND_NULL_ID' d35023 1 a35023 1 'FRAME_UNWIND_OUTERMOST' d35026 1 a35026 1 'FRAME_UNWIND_UNAVAILABLE' d35030 1 a35030 1 'FRAME_UNWIND_INNER_ID' d35035 1 a35035 1 'FRAME_UNWIND_SAME_ID' d35042 1 a35042 1 'FRAME_UNWIND_NO_SAVED_PC' d35046 1 a35046 1 'FRAME_UNWIND_MEMORY_ERROR' d35050 1 a35050 1 'FRAME_UNWIND_FIRST_ERROR' d35066 1 a35066 1 Return the frame's code block as a '' object. *Note d35071 1 a35071 1 '' object, or '#f' if there isn't one. *Note Symbols d35081 1 a35081 1 Return the frame's '' (symtab and line) object. *Note d35086 1 a35086 1 string, like 'pc'. d35093 2 a35094 2 given as a string or a '' object, and BLOCK must be a '' object. d35110 1 a35110 1 'frame-unwind-stop-reason' procedure above in this section). d35120 1 a35120 1 represented individually in Guile as an object of type ''. d35126 1 a35126 1 The outermost block is known as the "global block". The global block d35129 1 a35129 1 The block nested just inside the global block is the "static block". d35164 1 a35164 1 The following block-related procedures are provided by the '(gdb)' d35168 2 a35169 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d35172 1 a35172 1 Returns '#t' if '' BLOCK is valid, '#f' if not. A block d35174 1 a35174 1 anymore in the inferior. All other '' methods will d35180 1 a35180 1 Return the start address of '' BLOCK. d35183 1 a35183 1 Return the end address of '' BLOCK. d35186 2 a35187 2 Return the name of '' BLOCK represented as a '' object. If the block is not named, then '#f' is d35196 2 a35197 2 Return the block containing '' BLOCK. If the parent block does not exist, then '#f' is returned. d35200 1 a35200 1 Return the global block associated with '' BLOCK. d35203 1 a35203 1 Return the static block associated with '' BLOCK. d35206 2 a35207 2 Return '#t' if '' BLOCK is a global block. Otherwise return '#f'. d35210 2 a35211 2 Return '#t' if '' BLOCK is a static block. Otherwise return '#f'. d35215 1 a35215 1 '' BLOCK. d35218 1 a35218 1 Return an object of type '' that will iterate over d35226 2 a35227 2 This object would be obtained from the 'progress' element of the '' object returned by 'make-block-symbols-iterator'. d35230 1 a35230 1 Return the innermost '' containing the given PC value. d35232 1 a35232 1 function will return '#f'. d35242 1 a35242 1 these symbols in GDB with the '' object. d35244 1 a35244 1 The following symbol-related procedures are provided by the '(gdb)' d35248 2 a35249 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d35252 3 a35254 3 Return '#t' if the '' object is valid, '#f' if not. A '' object can become invalid if the symbol it refers to does not exist in GDB any longer. All other '' d35259 2 a35260 2 Return the type of SYMBOL or '#f' if no type is recorded. The result is an object of type ''. *Note Types In Guile::. d35264 1 a35264 1 object of type ''. *Note Symbol Tables In Guile::. d35279 1 a35279 1 either 'name' or 'linkage_name', depending on whether the user d35285 1 a35285 1 defined in the '(gdb)' module and described later in this chapter. d35288 2 a35289 2 Return '#t' if evaluating SYMBOL's value requires a frame (*note Frames In Guile::) and '#f' otherwise. Typically, local variables d35293 2 a35294 2 Return '#t' if SYMBOL is an argument of a function. Otherwise return '#f'. d35297 1 a35297 1 Return '#t' if SYMBOL is a constant. Otherwise return '#f'. d35300 2 a35301 2 Return '#t' if SYMBOL is a function or a method. Otherwise return '#f'. d35304 1 a35304 1 Return '#t' if SYMBOL is a variable. Otherwise return '#f'. d35307 1 a35307 1 Compute the value of SYMBOL, as a ''. For functions, d35321 1 a35321 1 BLOCK. The BLOCK argument must be a '' object. If d35324 1 a35324 1 DOMAIN argument must be a domain constant defined in the '(gdb)' d35328 4 a35331 4 '' object or '#f' if the symbol is not found. If the symbol is found, the second element is '#t' if the symbol is a field of a method's object (e.g., 'this' in C++), otherwise it is '#f'. If the symbol is not found, the second element is '#f'. d35339 1 a35339 1 DOMAIN argument must be a domain constant defined in the '(gdb)' d35342 1 a35342 1 The result is a '' object or '#f' if the symbol is not d35345 2 a35346 2 The available domain categories in '' are represented as constants in the '(gdb)' module: d35348 1 a35348 1 'SYMBOL_UNDEF_DOMAIN' d35353 1 a35353 1 'SYMBOL_VAR_DOMAIN' d35357 1 a35357 1 'SYMBOL_FUNCTION_DOMAIN' d35360 1 a35360 1 'SYMBOL_TYPE_DOMAIN' d35362 1 a35362 1 tag (the name appearing after a 'struct', 'union', or 'enum' d35366 1 a35366 1 'SYMBOL_STRUCT_DOMAIN' d35371 2 a35372 2 Here 'type_one' will be in 'SYMBOL_STRUCT_DOMAIN', but 'type_two' will be in 'SYMBOL_TYPE_DOMAIN'. d35374 1 a35374 1 'SYMBOL_LABEL_DOMAIN' d35377 2 a35378 2 'SYMBOL_VARIABLES_DOMAIN' This domain holds a subset of the 'SYMBOLS_VAR_DOMAIN'; it contains d35381 1 a35381 1 'SYMBOL_FUNCTIONS_DOMAIN' d35384 1 a35384 1 'SYMBOL_TYPES_DOMAIN' d35387 2 a35388 2 The available address class categories in '' are represented as constants in the 'gdb' module: d35394 3 a35396 3 each named after one of the preceding constants, but with the 'SEARCH' prefix replacing the 'SYMBOL' prefix; for example, 'SEARCH_LABEL_DOMAIN'. These may be or'd together to form a search d35399 1 a35399 1 'SYMBOL_LOC_UNDEF' d35403 1 a35403 1 'SYMBOL_LOC_CONST' d35406 1 a35406 1 'SYMBOL_LOC_STATIC' d35409 1 a35409 1 'SYMBOL_LOC_REGISTER' d35412 1 a35412 1 'SYMBOL_LOC_ARG' d35416 1 a35416 1 'SYMBOL_LOC_REF_ARG' d35418 1 a35418 1 'LOC_ARG' except that the value's address is stored at the offset, d35421 2 a35422 2 'SYMBOL_LOC_REGPARM_ADDR' Value is a specified register. Just like 'LOC_REGISTER' except the d35426 1 a35426 1 'SYMBOL_LOC_LOCAL' d35429 2 a35430 2 'SYMBOL_LOC_TYPEDEF' Value not used. Symbols in the domain 'SYMBOL_STRUCT_DOMAIN' all d35433 1 a35433 1 'SYMBOL_LOC_BLOCK' d35436 1 a35436 1 'SYMBOL_LOC_CONST_BYTES' d35439 1 a35439 1 'SYMBOL_LOC_UNRESOLVED' d35444 1 a35444 1 'SYMBOL_LOC_OPTIMIZED_OUT' d35447 1 a35447 1 'SYMBOL_LOC_COMPUTED' d35457 3 a35459 3 to Guile via two objects: '' (symtab-and-line) and ''. Symbol table and line data for a frame is returned from the 'frame-find-sal' '' procedure. *Note Frames In Guile::. d35464 1 a35464 1 The following symtab-related procedures are provided by the '(gdb)' d35468 2 a35469 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d35472 3 a35474 3 Return '#t' if the '' object is valid, '#f' if not. A '' object becomes invalid when the symbol table it refers to no longer exists in GDB. All other '' d35497 1 a35497 1 '(gdb)' module: d35500 2 a35501 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d35504 1 a35504 1 Return '#t' if SAL is valid, '#f' if not. A '' object d35506 1 a35506 1 exists in GDB. All other '' procedures will throw an d35510 1 a35510 1 Return the symbol table object ('') for SAL. d35522 3 a35524 3 Return the '' object corresponding to the PC value. If an invalid value of PC is passed as an argument, then the 'symtab' and 'line' attributes of the returned '' object will be '#f' d35534 3 a35536 3 ''. New breakpoints can be created with the 'make-breakpoint' Guile function, and then added to GDB with the 'register-breakpoint!' Guile function. This two-step approach is taken d35538 1 a35538 1 'make-breakpoint'. d35544 1 a35544 1 '(gdb)' module: d35551 2 a35552 2 contents can be any location recognized by the 'break' command, or in the case of a watchpoint, by the 'watch' command. d35554 1 a35554 1 The breakpoint is initially marked as 'invalid'. The breakpoint is d35556 2 a35557 2 'register-breakpoint!', at which point it becomes 'valid'. The result is the '' object representing the d35561 2 a35562 2 can be either 'BP_BREAKPOINT' or 'BP_WATCHPOINT', and defaults to 'BP_BREAKPOINT'. d35565 2 a35566 2 create, if TYPE is 'BP_WATCHPOINT'. If a watchpoint class is not provided, it is assumed to be a 'WP_WRITE' class. d35570 2 a35571 2 when registered, nor will it be listed in the output from 'info breakpoints' (but will be listed with the 'maint info breakpoints' d35578 1 a35578 1 it may be re-registered with 'register-breakpoint!'). d35582 4 a35585 4 changed from 'BP_WATCHPOINT' to 'BP_HARDWARE_WATCHPOINT' for 'WP_WRITE', 'BP_READ_WATCHPOINT' for 'WP_READ', and 'BP_ACCESS_WATCHPOINT' for 'WP_ACCESS'. If not successful, the type of the watchpoint is left as 'WP_WATCHPOINT'. d35588 1 a35588 1 'gdb' module: d35590 1 a35590 1 'BP_BREAKPOINT' d35593 1 a35593 1 'BP_WATCHPOINT' d35596 1 a35596 1 'BP_HARDWARE_WATCHPOINT' d35600 1 a35600 1 'BP_READ_WATCHPOINT' d35604 1 a35604 1 'BP_ACCESS_WATCHPOINT' d35608 1 a35608 1 'BP_CATCHPOINT' d35613 1 a35613 1 in the '(gdb)' module: d35615 1 a35615 1 'WP_READ' d35618 1 a35618 1 'WP_WRITE' d35621 1 a35621 1 'WP_ACCESS' d35625 1 a35625 1 Add BREAKPOINT, a '' object, to GDB's list of d35627 1 a35627 1 'make-breakpoint'. One cannot register breakpoints that have been d35629 1 a35629 1 becomes 'valid'. It is an error to register an already registered d35637 1 a35637 1 If BREAKPOINT was created from Guile with 'make-breakpoint' it may d35643 1 a35643 1 '' object. d35646 1 a35646 1 Return '#t' if OBJECT is a '' object, and '#f' d35650 4 a35653 4 Return '#t' if BREAKPOINT is valid, '#f' otherwise. Breakpoints created with 'make-breakpoint' are marked as invalid until they are registered with GDB with 'register-breakpoint!'. A '' object can become invalid if the user deletes d35664 1 a35664 1 Return '#t' if the breakpoint was created as a temporary d35667 1 a35667 1 other than 'breakpoint-valid?' and 'register-breakpoint!', will d35676 2 a35677 2 Return '#t' if the breakpoint is visible to the user when hit, or when the 'info breakpoints' command is run. Otherwise return '#f'. d35682 1 a35682 1 is, it is a watchpoint) return '#f'. d35687 1 a35687 1 breakpoint is not a watchpoint) return '#f'. d35690 1 a35690 1 Return '#t' if the breakpoint is enabled, and '#f' otherwise. d35693 1 a35693 1 Set the enabled state of BREAKPOINT to FLAG. If flag is '#f' it is d35697 1 a35697 1 Return '#t' if the breakpoint is silent, and '#f' otherwise. d35700 2 a35701 2 the first command is 'silent'. This is not reported by the 'silent' attribute. d35704 1 a35704 1 Set the silent state of BREAKPOINT to FLAG. If flag is '#f' the d35728 1 a35728 1 '#f', the breakpoint is no longer thread-specific. d35733 1 a35733 1 not Ada), return '#f'. d35736 1 a35736 1 Set the Ada task of BREAKPOINT to TASK. If set to '#f', the d35741 1 a35741 1 is a string. If there is no condition, return '#f'. d35745 1 a35745 1 string. If set to '#f' then the breakpoint becomes unconditional. d35749 1 a35749 1 'set-breakpoint-stop!' below in this section. d35755 1 a35755 1 reaches this breakpoint. If it returns '#t', or any non-'#f' d35760 2 a35761 2 'stop' predicate, each one will be called regardless of the return status of the previous. This ensures that all 'stop' predicates d35763 1 a35763 1 of the methods returns '#t' but the others return '#f', the d35772 1 a35772 1 Example 'stop' implementation: d35782 1 a35782 1 Return the commands attached to BREAKPOINT as a string, or '#f' if d35791 1 a35791 1 A "lazy string" is a string whose contents is not retrieved or encoded d35794 3 a35796 3 A '' is represented in GDB as an 'address' that points to a region of memory, an 'encoding' that will be used to encode that region of memory, and a 'length' to delimit the region of memory d35798 4 a35801 4 '' and a string wrapped within a '' is that a '' will be treated differently by GDB when printing. A '' is retrieved and encoded during printing, while a '' wrapping a string is immediately retrieved and encoded on d35805 1 a35805 1 '(gdb)' module: d35808 2 a35809 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d35828 1 a35828 1 the lazy string's character type, use 'type-target-type'. *Note d35832 1 a35832 1 Convert the '' to a ''. This value d35835 1 a35835 1 ''. d35845 1 a35845 1 of the '' class. d35848 1 a35848 1 '(gdb)' module: d35851 2 a35852 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d35855 1 a35855 1 Return the current architecture as a '' object. d35858 1 a35858 1 Return the name (string value) of '' ARCH. d35861 1 a35861 1 Return name of target character set of '' ARCH. d35864 1 a35864 1 Return name of target wide character set of '' ARCH. d35870 1 a35870 1 Return the '' object for a 'void' type of architecture d35874 1 a35874 1 Return the '' object for a 'char' type of architecture d35878 1 a35878 1 Return the '' object for a 'short' type of architecture d35882 1 a35882 1 Return the '' object for an 'int' type of architecture d35886 1 a35886 1 Return the '' object for a 'long' type of architecture d35890 1 a35890 1 Return the '' object for a 'signed char' type of d35894 1 a35894 1 Return the '' object for an 'unsigned char' type of d35898 1 a35898 1 Return the '' object for an 'unsigned short' type of d35902 1 a35902 1 Return the '' object for an 'unsigned int' type of d35906 1 a35906 1 Return the '' object for an 'unsigned long' type of d35910 1 a35910 1 Return the '' object for a 'float' type of architecture d35914 1 a35914 1 Return the '' object for a 'double' type of architecture d35918 1 a35918 1 Return the '' object for a 'long double' type of d35922 1 a35922 1 Return the '' object for a 'bool' type of architecture d35926 1 a35926 1 Return the '' object for a 'long long' type of d35930 1 a35930 1 Return the '' object for an 'unsigned long long' type of d35934 1 a35934 1 Return the '' object for an 'int8' type of architecture d35938 1 a35938 1 Return the '' object for a 'uint8' type of architecture d35942 1 a35942 1 Return the '' object for an 'int16' type of architecture d35946 1 a35946 1 Return the '' object for a 'uint16' type of architecture d35950 1 a35950 1 Return the '' object for an 'int32' type of architecture d35954 1 a35954 1 Return the '' object for a 'uint32' type of architecture d35958 1 a35958 1 Return the '' object for an 'int64' type of architecture d35962 1 a35962 1 Return the '' object for a 'uint64' type of architecture d35986 1 a35986 1 from. If PORT is '#f' then bytes are read from target memory. d35990 1 a35990 1 specifies a 'bytevector' and you want the bytevector to be d36022 1 a36022 1 'address' d36026 1 a36026 1 'asm' d36030 1 a36030 1 specified by the current CLI variable 'disassembly-flavor'. d36033 1 a36033 1 'length' d36053 1 a36053 1 Return '#t' if OBJECT is a GDB stdio port. Otherwise return '#f'. d36061 1 a36061 1 GDB provides a 'port' interface to target memory. This allows Guile d36063 1 a36063 1 functionality. The main routine is 'open-memory' which returns a port d36071 4 a36074 4 '"a"' and '"l"' modes are not supported. *Note (guile)File Ports::. The '"b"' (binary) character may be present, but is ignored: memory ports are binary only. If '"0"' is appended then the port is marked as unbuffered. The default is '"r"', read-only d36085 2 a36086 2 Return '#t' if OBJECT is an object of type ''. Otherwise return '#f'. d36089 2 a36090 2 Return the range of '' MEMORY-PORT as a list of two elements: '(start end)'. The range is START to END inclusive. d36093 1 a36093 1 Return the size of the read buffer of '' d36100 1 a36100 1 Set the size of the read buffer of '' MEMORY-PORT d36104 2 a36105 2 GDB is built with Guile 2.2 or later, you can call 'setvbuf' instead (*note 'setvbuf': (guile)Buffering.). d36108 1 a36108 1 Return the size of the write buffer of '' d36116 1 a36116 1 Set the size of the write buffer of '' MEMORY-PORT d36120 1 a36120 1 GDB is built with Guile 2.2 or later, you can call 'setvbuf' d36123 1 a36123 1 A memory port is closed like any other port, with 'close-port'. d36125 1 a36125 1 Combined with Guile's 'bytevectors', memory ports provide a lot of d36156 1 a36156 1 A '' object is constructed with the 'make-iterator' d36163 4 a36166 4 '(end-of-iteration)', and may be tested with the 'end-of-iteration?' predicate. The result of '(end-of-iteration)' is chosen so that it is not otherwise used by the '(gdb)' module. If you are using '' in your own code it is your d36184 1 a36184 1 all the functions in 'my-global-block'. d36194 2 a36195 2 Return '#t' if OBJECT is a '' object. Otherwise return '#f'. d36198 1 a36198 1 Return the first argument that was passed to 'make-iterator'. This d36209 1 a36209 1 'make-iterator', passing it one argument, the '' d36211 2 a36212 2 an end marker as implemented by the 'next!' procedure. By convention the end marker is the result of '(end-of-iteration)'. d36218 2 a36219 2 Return '#t' if OBJECT is the end of iteration marker. Otherwise return '#f'. d36221 1 a36221 1 These functions are provided by the '(gdb iterator)' module to assist d36225 1 a36225 1 Return a '' object that will iterate over LIST. d36243 2 a36244 2 Run ITERATOR until the result of '(pred element)' is true and return that as the result. Otherwise return '#f'. d36252 1 a36252 1 When a new object file is read (for example, due to the 'file' command, d36254 2 a36255 2 Guile support scripts in two ways: 'OBJFILE-gdb.scm' and the '.debug_gdb_scripts' section. *Note Auto-loading extensions::. d36263 1 a36263 1 'set auto-load guile-scripts [on|off]' d36266 1 a36266 1 'show auto-load guile-scripts' d36269 1 a36269 1 'info auto-load guile-scripts [REGEXP]' d36273 1 a36273 1 the '.debug_gdb_scripts' section and were not found. This is d36289 2 a36290 2 When reading an auto-loaded file, GDB sets the "current objfile". This is available via the 'current-objfile' procedure (*note Objfiles In d36322 1 a36322 1 The OBJECT must either be a '' object, or '#f' in d36327 1 a36327 1 The OBJECT must either be a '' object, or '#f' in d36337 1 a36337 1 '' objects. d36363 3 a36365 3 Return '#t' if TYPE, assumed to be a type with fields (e.g., a structure or union), has field FIELD. Otherwise return '#f'. This searches baseclasses, whereas 'type-has-field?' does not. d36369 1 a36369 1 hash table are referenced with 'hashq-ref'. d36378 5 a36382 5 new object file is read (for example, due to the 'file' command, or because the inferior has loaded a shared library): 'OBJFILE-gdb.EXT' (*note The 'OBJFILE-gdb.EXT' file: objfile-gdbdotext file.) and the '.debug_gdb_scripts' section of modern file formats like ELF (*note The '.debug_gdb_scripts' section: dotdebug_gdb_scripts section.). For a d36390 1 a36390 1 scripts can be printed. See the 'auto-loading' section of each d36396 1 a36396 1 configured 'auto-load safe-path' (*note Auto-loading safe path::). d36400 2 a36401 2 * objfile-gdbdotext file:: The 'OBJFILE-gdb.EXT' file * dotdebug_gdb_scripts section:: The '.debug_gdb_scripts' section d36407 1 a36407 1 23.5.1 The 'OBJFILE-gdb.EXT' file d36411 1 a36411 1 'OBJFILE-gdb.EXT' (we call it SCRIPT-NAME below), where OBJFILE is the d36415 1 a36415 1 'OBJFILE-gdb.gdb' d36417 1 a36417 1 'OBJFILE-gdb.py' d36419 1 a36419 1 'OBJFILE-gdb.scm' d36423 2 a36424 2 absolute, following all symlinks, and resolving '.' and '..' components, and appending the '-gdb.EXT' suffix. If this file exists and is d36431 2 a36432 2 a one-letter subdirectory, i.e. 'd:/usr/bin/' is converted to '/d/usr/bin/', because Windows filesystems disallow colons in file d36436 1 a36436 1 'auto-load safe-path' (*note Auto-loading safe path::). d36438 2 a36439 2 For object files using '.exe' suffix GDB tries to load first the scripts normally according to its '.exe' filename. But if no scripts d36441 1 a36441 1 without its '.exe' suffix. This '.exe' stripping is case insensitive d36445 1 a36445 1 'set auto-load scripts-directory [DIRECTORIES]' d36448 1 a36448 1 (':' on Unix, ';' on MS-Windows and MS-DOS). d36451 1 a36451 1 'set auto-load safe-path' (*note set auto-load safe-path::). d36453 3 a36455 3 This variable defaults to '$debugdir:$datadir/auto-load'. The default 'set auto-load safe-path' value can be also overridden by GDB configuration option '--with-auto-load-dir'. d36457 1 a36457 1 Any reference to '$debugdir' will get replaced by d36459 4 a36462 4 reference to '$datadir' will get replaced by DATA-DIRECTORY which is determined at GDB startup (*note Data Files::). '$debugdir' and '$datadir' must be placed as a directory component -- either alone or delimited by '/' or '\' directory separators, depending on the d36465 3 a36467 3 The list of directories uses path separator (':' on GNU and Unix systems, ';' on MS-Windows and MS-DOS) to separate directories, similarly to the 'PATH' environment variable. d36469 1 a36469 1 'show auto-load scripts-directory' d36472 1 a36472 1 'add-auto-load-scripts-directory [DIRECTORIES...]' d36479 1 a36479 1 is opened. So your '-gdb.EXT' file should be careful to avoid errors if d36485 1 a36485 1 23.5.2 The '.debug_gdb_scripts' section d36490 1 a36490 1 '.debug_gdb_scripts'. If this section exists, its contents is a list of d36494 1 a36494 1 '.debug_gdb_scripts'. d36498 4 a36501 4 'SECTION_SCRIPT_ID_PYTHON_FILE = 1' 'SECTION_SCRIPT_ID_SCHEME_FILE = 3' 'SECTION_SCRIPT_ID_PYTHON_TEXT = 4' 'SECTION_SCRIPT_ID_SCHEME_TEXT = 6' d36508 1 a36508 1 Specifying Source Directories: Source Path.), except that '$cdir' is not d36511 1 a36511 1 File entries can be placed in section '.debug_gdb_scripts' with, for d36523 1 a36523 1 For Guile scripts, replace '.byte 1' with '.byte 3'. Then one can d36531 1 a36531 1 configured 'auto-load safe-path' (*note Auto-loading safe path::). d36535 1 a36535 1 and with the use of '"MS"' attributes on the section, the linker will d36543 1 a36543 1 everything after the prefix byte and up to the first newline ('0xa') d36550 1 a36550 1 Here is an example from file 'py-section-script.c' in the GDB d36570 4 a36573 4 Loading of inlined scripts requires a properly configured 'auto-load safe-path' (*note Auto-loading safe path::). The path to specify in 'auto-load safe-path' is the path of the file containing the '.debug_gdb_scripts' section. d36584 1 a36584 1 Benefits of the '-gdb.EXT' way: d36586 1 a36586 1 * Can be used with file formats that don't support multiple sections. d36588 1 a36588 1 * Ease of finding scripts for public libraries. d36590 1 a36590 1 Scripts specified in the '.debug_gdb_scripts' section are searched d36592 1 a36592 1 e.g., 'libstdc++', there typically isn't a source directory in d36595 1 a36595 1 * Doesn't require source code additions. d36597 1 a36597 1 Benefits of the '.debug_gdb_scripts' way: d36599 1 a36599 1 * Works with static linking. d36601 1 a36601 1 Scripts for libraries done the '-gdb.EXT' way require an objfile to d36605 1 a36605 1 executable's '-gdb.EXT' script. d36607 1 a36607 1 * Works with classes that are entirely inlined. d36610 1 a36610 1 associated shared library to attach a '-gdb.EXT' script to. d36612 1 a36612 1 * Scripts needn't be copied out of the source tree. d36616 1 a36616 1 install the '-gdb.EXT' scripts in a place where GDB can find them d36618 1 a36618 1 '.debug_gdb_scripts' section as relative paths, and add a path to d36662 1 a36662 1 the '-i' or '--interpreter' startup options. Defined interpreters d36665 1 a36665 1 'console' d36670 1 a36670 1 'dap' d36678 2 a36679 2 'mi' The newest GDB/MI interface (currently 'mi3'). Used primarily by d36683 1 a36683 1 'mi3' d36686 1 a36686 1 'mi2' d36691 1 a36691 1 console interpreter, simply use the 'interpreter-exec' command: d36698 1 a36698 1 Note that 'interpreter-exec' only changes the interpreter for the d36715 2 a36716 2 To start a new secondary "user interface" running MI, use the 'new-ui' command: d36721 2 a36722 2 accepts the same values as the 'interpreter-exec' command. For example, 'console', 'mi', 'mi2', etc. The TTY parameter specifies the name of d36728 1 a36728 1 runs an MI interpreter on '/dev/pts/9'. d36737 1 a36737 1 'curses' library to show the source file, the assembly output, the d36740 1 a36740 1 'curses' library is available. d36742 1 a36742 1 The TUI mode is enabled by default when you invoke GDB as 'gdb -tui'. d36744 2 a36745 2 various TUI commands and key bindings, such as 'tui enable' or 'C-x C-a'. *Note TUI Commands: TUI Commands, and *note TUI Key Bindings: TUI d36781 1 a36781 1 highlighting the current line and marking it with a '>' marker. By d36783 2 a36784 2 highlighted text, but you can enable it with the 'set style tui-current-position on' command. *Note Output Styling::. d36789 1 a36789 1 'B' d36792 1 a36792 1 'b' d36795 1 a36795 1 'H' d36798 1 a36798 1 'h' d36803 1 a36803 1 '+' d36806 1 a36806 1 '-' d36817 1 a36817 1 * source only, d36819 1 a36819 1 * assembly only, d36821 1 a36821 1 * source and assembly, d36823 1 a36823 1 * source and registers, or d36825 1 a36825 1 * assembly and registers. d36838 1 a36838 1 being debugged, this field is set to 'No process'. d36847 1 a36847 1 counter, the string '??' is displayed. d36851 1 a36851 1 current line number is not known, the string '??' is displayed. d36866 3 a36868 3 'C-x C-a' 'C-x a' 'C-x A' d36876 1 a36876 1 'tui-switch-mode'. d36878 1 a36878 1 'C-x 1' d36880 1 a36880 1 'source' or 'assembly'. When the TUI mode is not active, it will d36883 1 a36883 1 Think of this key binding as the Emacs 'C-x 1' binding. d36886 1 a36886 1 'tui-delete-other-windows'. d36888 1 a36888 1 'C-x 2' d36894 1 a36894 1 Think of it as the Emacs 'C-x 2' binding. d36897 1 a36897 1 'tui-change-windows'. d36899 1 a36899 1 'C-x o' d36904 1 a36904 1 Think of it as the Emacs 'C-x o' binding. d36907 1 a36907 1 'tui-other-window'. d36909 1 a36909 1 'C-x s' d36913 1 a36913 1 This key binding uses the bindable Readline function 'next-keymap'. d36935 1 a36935 1 'C-L' d36941 1 a36941 1 readline key bindings such as 'C-p', 'C-n', 'C-b' and 'C-f' to control d36950 2 a36951 2 The TUI also provides a "SingleKey" mode, which binds several frequently used GDB commands to single keys. Type 'C-x s' to switch into this d36954 1 a36954 1 'c' d36957 1 a36957 1 'C' d36960 1 a36960 1 'd' d36963 1 a36963 1 'f' d36966 1 a36966 1 'F' d36969 1 a36969 1 'n' d36972 1 a36972 1 'N' d36975 2 a36976 2 'o' nexti. The shortcut letter 'o' stands for "step Over". d36978 1 a36978 1 'O' d36981 1 a36981 1 'q' d36984 1 a36984 1 'r' d36987 1 a36987 1 's' d36990 1 a36990 1 'S' d36993 2 a36994 2 'i' stepi. The shortcut letter 'i' stands for "step Into". d36996 1 a36996 1 'I' d36999 1 a36999 1 'u' d37002 1 a37002 1 'v' d37005 1 a37005 1 'w' d37012 2 a37013 2 restored. The only way to permanently leave this mode is by typing 'q' or 'C-x s'. d37016 1 a37016 1 will be named 'SingleKey'. This can be used in '.inputrc' to add d37039 1 a37039 1 off the 'tui mouse-events' setting (*note set tui mouse-events: d37056 1 a37056 1 Note that if GDB's 'stdout' is not connected to a terminal, or GDB d37062 1 a37062 1 'tui enable' d37067 1 a37067 1 'tui disable' d37070 1 a37070 1 'info win' d37073 1 a37073 1 'tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT...]' d37075 1 a37075 1 can be accessed using the 'layout' command (see below). d37082 1 a37082 1 'focus' command (see below); additionally, the 'status' window can d37085 1 a37085 1 conventional to use '0' here. d37087 2 a37088 2 A window description looks a bit like an invocation of 'tui new-layout', and is of the form {['-horizontal']WINDOW WEIGHT d37091 1 a37091 1 This specifies a sub-layout. If '-horizontal' is given, the d37103 1 a37103 1 Here, the new layout is called 'example'. It shows the source and d37119 2 a37120 2 'tui layout NAME' 'layout NAME' d37124 1 a37124 1 using 'tui new-layout'. d37128 1 a37128 1 'next' d37131 1 a37131 1 'prev' d37134 1 a37134 1 'src' d37137 1 a37137 1 'asm' d37140 1 a37140 1 'split' d37143 3 a37145 3 'regs' When in 'src' layout display the register, source, and command windows. When in 'asm' or 'split' layout display the d37148 2 a37149 2 'tui focus NAME' 'focus NAME' d37153 1 a37153 1 'next' d37156 1 a37156 1 'prev' d37159 1 a37159 1 'src' d37162 1 a37162 1 'asm' d37165 1 a37165 1 'regs' d37168 1 a37168 1 'cmd' d37171 3 a37173 3 'tui refresh' 'refresh' Refresh the screen. This is similar to typing 'C-L'. d37175 1 a37175 1 'tui reg GROUP' d37181 1 a37181 1 'next' d37185 1 a37185 1 'prev' d37190 1 a37190 1 'general' d37192 1 a37192 1 'float' d37194 1 a37194 1 'system' d37196 1 a37196 1 'vector' d37198 1 a37198 1 'all' d37201 1 a37201 1 'update' d37204 4 a37207 4 'tui window height NAME +COUNT' 'tui window height NAME -COUNT' 'winheight NAME +COUNT' 'winheight NAME -COUNT' d37212 1 a37212 1 'info win' (*note info win: info_win_command.). d37219 4 a37222 4 'tui window width NAME +COUNT' 'tui window width NAME -COUNT' 'winwidth NAME +COUNT' 'winwidth NAME -COUNT' d37227 1 a37227 1 'info win' (*note info win: info_win_command.). d37242 1 a37242 1 'set tui border-kind KIND' d37245 1 a37245 1 'space' d37248 2 a37249 2 'ascii' Use ASCII characters '+', '-' and '|' to draw the border. d37251 1 a37251 1 'acs' d37256 2 a37257 2 'set tui border-mode MODE' 'set tui active-border-mode MODE' d37261 1 a37261 1 'normal' d37264 1 a37264 1 'standout' d37267 1 a37267 1 'reverse' d37270 1 a37270 1 'half' d37273 1 a37273 1 'half-standout' d37276 1 a37276 1 'bold' d37279 1 a37279 1 'bold-standout' d37282 1 a37282 1 'set tui tab-width NCHARS' d37287 1 a37287 1 'set tui compact-source [on|off]' d37293 1 a37293 1 'set tui mouse-events [on|off]' d37298 1 a37298 1 'set debug tui [on|off]' d37302 1 a37302 1 'show debug tui' d37307 1 a37307 1 appropriate 'set style' commands. *Note Output Styling::. d37318 1 a37318 1 To use this interface, use the command 'M-x gdb' in Emacs. Give the d37326 1 a37326 1 * All "terminal" input and output goes through an Emacs buffer, d37338 1 a37338 1 the usual way--for example, 'C-c C-c' for an interrupt, 'C-c C-z' d37341 1 a37341 1 * GDB displays source code through Emacs. d37344 1 a37344 1 source file for that frame and puts an arrow ('=>') at the left d37349 1 a37349 1 Explicit GDB 'list' or search commands still produce output as d37352 1 a37352 1 We call this "text command mode". Emacs 22.1, and later, also uses a d37357 1 a37357 1 If you specify an absolute file name when prompted for the 'M-x gdb' d37362 1 a37362 1 your environment's 'PATH' variable, but on some operating systems it d37372 1 a37372 1 By default, 'M-x gdb' calls the program called 'gdb'. If you need to d37375 1 a37375 1 variable 'gud-gdb-command-name' to run the one you want. d37380 1 a37380 1 'C-h m' d37383 2 a37384 2 'C-c C-s' Execute to another source line, like the GDB 'step' command; also d37387 1 a37387 1 'C-c C-n' d37389 1 a37389 1 calls, like the GDB 'next' command. Then update the display window d37392 2 a37393 2 'C-c C-i' Execute one instruction, like the GDB 'stepi' command; update d37396 1 a37396 1 'C-c C-f' d37398 1 a37398 1 'finish' command. d37400 2 a37401 2 'C-c C-r' Continue execution of your program, like the GDB 'continue' d37404 1 a37404 1 'C-c <' d37406 1 a37406 1 Numeric Arguments: (Emacs)Arguments.), like the GDB 'up' command. d37408 1 a37408 1 'C-c >' d37410 1 a37410 1 like the GDB 'down' command. d37412 1 a37412 1 In any source file, the Emacs command 'C-x ' ('gud-break') tells d37415 1 a37415 1 In text command mode, if you type 'M-x speedbar', Emacs displays a d37419 1 a37419 1 buffer. Alternatively, click 'Mouse-2' to make the selected frame d37424 1 a37424 1 get it back is to type the command 'f' in the GDB buffer, to request a d37475 1 a37475 1 activated by specifying using the '--interpreter' command line option d37492 1 a37492 1 * '|' separates two alternatives. d37494 1 a37494 1 * '[ SOMETHING ]' indicates that SOMETHING is optional: it may or may d37497 1 a37497 1 * '( GROUP )*' means that GROUP inside the parentheses may repeat d37500 1 a37500 1 * '( GROUP )+' means that GROUP inside the parentheses may repeat one d37503 1 a37503 1 * '( GROUP )' means that GROUP inside the parentheses occurs exactly d37506 1 a37506 1 * '"STRING"' means a literal STRING. d37554 1 a37554 1 * Exec notifications. These are used to report changes in target d37562 1 a37562 1 * Console output, and status notifications. Console output d37569 1 a37569 1 * General notifications. Commands may have various side effects on d37614 1 a37614 1 MI command accepts the '--thread' and '--frame' options, the value to d37622 2 a37623 2 hit. For another example, if the user issues the CLI 'thread' or 'frame' commands via the frontend, it is desirable to change the d37626 1 a37626 1 '=thread-selected' notification. d37629 1 a37629 1 frontends used the '-thread-select' to execute commands in the right d37631 1 a37631 1 simplest way is for frontend to emit '-thread-select' command before d37633 1 a37633 1 sent. The alternative approach is to suppress '-thread-select' if the d37640 1 a37640 1 add '-thread-select' for all subsequent commands. No frontend is known d37642 1 a37642 1 '--thread' and '--frame' options. d37650 1 a37650 1 the '--language' option. This option takes one argument, which is the d37657 3 a37659 3 The valid language names are the same names accepted by the 'set language' command (*note Manually::), excluding 'auto', 'local' or 'unknown'. d37668 1 a37668 1 target is running. This is called "asynchronous command execution" d37670 1 a37670 1 for asynchronous execution using the '-gdb-set mi-async 1' command, d37674 1 a37674 1 enabled using the '-list-target-features' command. d37676 1 a37676 1 '-gdb-set mi-async [on|off]' d37679 2 a37680 2 When 'off', which is the default, MI execution commands (e.g., '-exec-continue') are foreground commands, and GDB waits for the d37683 2 a37684 2 When 'on', MI execution commands are background execution commands (e.g., '-exec-continue' becomes the equivalent of the 'c&' CLI d37688 1 a37688 1 '-gdb-show mi-async' d37692 1 a37692 1 'target-async' instead of 'mi-async', and it had the effect of both d37709 1 a37709 1 that even commands that operate on global state, such as 'print', 'set', d37712 1 a37712 1 perform the operation on that thread (using the '--thread' option). d37715 2 a37716 2 target dependent. However, the two commands '-exec-interrupt', to stop a thread, and '-thread-info', to find the state of a thread, will always d37733 1 a37733 1 accept the '--thread' option do not need to know what process that d37735 1 a37735 1 additional '--process' option, nor an notion of the current process in d37741 1 a37741 1 "thread group". Thread group is a collection of threads and other d37744 1 a37744 1 '-list-thread-groups', returns the list of top-level thread groups, d37746 1 a37746 1 passing an identifier of a thread group to the '-list-thread-groups' d37750 1 a37750 1 wishes to debug, a concept of "available thread group" is introduced. d37752 1 a37752 1 that can be attached to, using the '-target-attach' command. The list d37754 1 a37754 1 '-list-thread-groups --available'. In general, the content of a thread d37759 1 a37759 1 special type 'process', and some additional operations are permitted on d37779 2 a37780 2 'COMMAND ==>' 'CLI-COMMAND | MI-COMMAND' d37782 2 a37783 2 'CLI-COMMAND ==>' '[ TOKEN ] CLI-COMMAND NL', where CLI-COMMAND is any existing GDB d37786 3 a37788 3 'MI-COMMAND ==>' '[ TOKEN ] "-" OPERATION ( " " OPTION )* [ " --" ] ( " " PARAMETER )* NL' d37790 1 a37790 1 'TOKEN ==>' d37793 2 a37794 2 'OPTION ==>' '"-" PARAMETER [ " " PARAMETER ]' d37796 2 a37797 2 'PARAMETER ==>' 'NON-BLANK-SEQUENCE | C-STRING' d37799 1 a37799 1 'OPERATION ==>' d37802 1 a37802 1 'NON-BLANK-SEQUENCE ==>' d37806 2 a37807 2 'C-STRING ==>' '""" SEVEN-BIT-ISO-C-STRING-CONTENT """' d37809 2 a37810 2 'NL ==>' 'CR | CR-LF' d37814 1 a37814 1 * The CLI commands are still handled by the MI interpreter; their d37817 1 a37817 1 * The 'TOKEN', when present, is passed back when the command d37820 2 a37821 2 * Some MI commands accept optional arguments as part of the parameter list. Each option is identified by a leading '-' (dash) and may be d37824 1 a37824 1 using '--' (this is useful when some parameters begin with a dash). d37828 1 a37828 1 * We want easy access to the existing CLI syntax (for debugging). d37830 1 a37830 1 * We want it to be easy to spot a MI operation. d37841 1 a37841 1 terminated by '(gdb)'. d37843 1 a37843 1 If an input command was prefixed with a 'TOKEN' then the d37847 2 a37848 2 'OUTPUT ==>' '( OUT-OF-BAND-RECORD )* [ RESULT-RECORD ] "(gdb)" NL' d37850 2 a37851 2 'RESULT-RECORD ==>' ' [ TOKEN ] "^" RESULT-CLASS ( "," RESULT )* NL' d37853 2 a37854 2 'OUT-OF-BAND-RECORD ==>' 'ASYNC-RECORD | STREAM-RECORD' d37856 2 a37857 2 'ASYNC-RECORD ==>' 'EXEC-ASYNC-OUTPUT | STATUS-ASYNC-OUTPUT | NOTIFY-ASYNC-OUTPUT' d37859 2 a37860 2 'EXEC-ASYNC-OUTPUT ==>' '[ TOKEN ] "*" ASYNC-OUTPUT NL' d37862 2 a37863 2 'STATUS-ASYNC-OUTPUT ==>' '[ TOKEN ] "+" ASYNC-OUTPUT NL' d37865 2 a37866 2 'NOTIFY-ASYNC-OUTPUT ==>' '[ TOKEN ] "=" ASYNC-OUTPUT NL' d37868 2 a37869 2 'ASYNC-OUTPUT ==>' 'ASYNC-CLASS ( "," RESULT )*' d37871 2 a37872 2 'RESULT-CLASS ==>' '"done" | "running" | "connected" | "error" | "exit"' d37874 2 a37875 2 'ASYNC-CLASS ==>' '"stopped" | OTHERS' (where OTHERS will be added depending on the d37878 2 a37879 2 'RESULT ==>' ' VARIABLE "=" VALUE' d37881 2 a37882 2 'VARIABLE ==>' ' STRING ' d37884 2 a37885 2 'VALUE ==>' ' CONST | TUPLE | LIST ' d37887 2 a37888 2 'CONST ==>' 'C-STRING' d37890 2 a37891 2 'TUPLE ==>' ' "{}" | "{" RESULT ( "," RESULT )* "}" ' d37893 3 a37895 3 'LIST ==>' ' "[]" | "[" VALUE ( "," VALUE )* "]" | "[" RESULT ( "," RESULT )* "]" ' d37897 2 a37898 2 'STREAM-RECORD ==>' 'CONSOLE-STREAM-OUTPUT | TARGET-STREAM-OUTPUT | LOG-STREAM-OUTPUT' d37900 2 a37901 2 'CONSOLE-STREAM-OUTPUT ==>' '"~" C-STRING NL' d37903 2 a37904 2 'TARGET-STREAM-OUTPUT ==>' '"@@" C-STRING NL' d37906 2 a37907 2 'LOG-STREAM-OUTPUT ==>' '"&" C-STRING NL' d37909 2 a37910 2 'NL ==>' 'CR | CR-LF' d37912 1 a37912 1 'TOKEN ==>' d37917 1 a37917 1 * All output sequences end in a single line containing a period. d37919 1 a37919 1 * The 'TOKEN' is from the corresponding request. Note that for all d37926 1 a37926 1 * STATUS-ASYNC-OUTPUT contains on-going status information about the d37928 1 a37928 1 output is prefixed by '+'. d37930 1 a37930 1 * EXEC-ASYNC-OUTPUT contains asynchronous state change on the target d37932 1 a37932 1 '*'. d37934 1 a37934 1 * NOTIFY-ASYNC-OUTPUT contains supplementary information that the d37936 1 a37936 1 notify output is prefixed by '='. d37938 1 a37938 1 * CONSOLE-STREAM-OUTPUT is output that should be displayed as is in d37940 1 a37940 1 console output is prefixed by '~'. d37942 2 a37943 2 * TARGET-STREAM-OUTPUT is the output produced by the target program. All the target output is prefixed by '@@'. d37945 1 a37945 1 * LOG-STREAM-OUTPUT is output text coming from GDB's internals, for d37947 1 a37947 1 All the log output is prefixed by '&'. d37949 1 a37949 1 * New GDB/MI commands should only output LISTS containing VALUES. d37963 2 a37964 2 command lists are not executed and some CLI commands, such as 'if', 'when' and 'define', prompt for further input with '>', which is not d37968 1 a37968 1 recommended that front ends use the '-interpreter-exec' command (*note d37978 1 a37978 1 program being debugged to the user is called a "front end". d37990 1 a37990 1 * New MI commands may be added. d37992 1 a37992 1 * New fields may be added to the output of any MI command. d37994 2 a37995 2 * The range of values for fields with specified values, e.g., 'in_scope' (*note -var-update::) may be extended. d38003 1 a38003 1 Since '--interpreter=mi' always points to the latest MI version, it d38005 1 a38005 1 launching GDB (e.g. '--interpreter=mi2') to make sure they get an d38018 2 a38019 2 * The '-environment-pwd', '-environment-directory' and '-environment-path' commands now returns values d38023 1 a38023 1 * '-var-list-children''s 'children' result field is d38026 1 a38026 1 * '-var-update''s 'changelist' result field is now a d38030 1 a38030 1 * The output of information about multi-location d38032 4 a38035 4 '-break-insert' and '-break-info' commands, as well as in the '=breakpoint-created' and '=breakpoint-modified' events. The multiple locations are now placed in a 'locations' field, d38039 1 a38039 1 * The syntax of the "script" field in breakpoint d38041 3 a38043 3 '-break-insert' and '-break-info' commands, as well as the '=breakpoint-created' and '=breakpoint-modified' events. The previous output d38052 1 a38052 1 '-fix-multi-location-breakpoint-output' d38057 1 a38057 1 '-fix-breakpoint-script-output' d38091 2 a38092 2 '"^done" [ "," RESULTS ]' The synchronous operation was successful, 'RESULTS' are the return d38095 3 a38097 3 '"^running"' This result record is equivalent to '^done'. Historically, it was output instead of '^done' if the command has resumed the target. d38099 2 a38100 2 frontends should treat '^done' and '^running' identically and rely on the '*running' output record to determine which threads are d38103 1 a38103 1 '"^connected"' d38106 2 a38107 2 '"^error" "," "msg=" C-STRING [ "," "code=" C-STRING ]' The operation failed. The 'msg=C-STRING' variable contains the d38110 1 a38110 1 If present, the 'code=C-STRING' variable provides an error code on d38114 1 a38114 1 '"undefined-command"' d38117 1 a38117 1 '"^exit"' d38128 1 a38128 1 funneled through the GDB/MI interface using "stream records". d38130 1 a38130 1 Each stream record begins with a unique "prefix character" which d38133 1 a38133 1 'STRING-OUTPUT'. This is either raw text (with an implicit new line) or d38136 1 a38136 1 '"~" STRING-OUTPUT' d38141 1 a38141 1 '"@@" STRING-OUTPUT' d38147 1 a38147 1 '"&" STRING-OUTPUT' d38157 1 a38157 1 "Async" records are used to notify the GDB/MI client of additional d38164 1 a38164 1 '*running,thread-id="THREAD"' d38166 1 a38166 1 thread ID of the thread that is now running, and it can be 'all' if d38176 1 a38176 1 '*stopped,reason="REASON",thread-id="ID",stopped-threads="STOPPED",core="CORE"' d38180 1 a38180 1 'breakpoint-hit' d38182 1 a38182 1 'watchpoint-trigger' d38184 1 a38184 1 'read-watchpoint-trigger' d38186 1 a38186 1 'access-watchpoint-trigger' d38188 1 a38188 1 'function-finished' d38190 1 a38190 1 'location-reached' d38192 1 a38192 1 'watchpoint-scope' d38194 1 a38194 1 'end-stepping-range' d38198 1 a38198 1 'exited-signalled' d38200 1 a38200 1 'exited' d38202 1 a38202 1 'exited-normally' d38204 1 a38204 1 'signal-received' d38206 1 a38206 1 'solib-event' d38208 2 a38209 2 unloaded. This can happen when 'stop-on-solib-events' (*note Files::) is set or when a 'catch load' or 'catch unload' d38211 2 a38212 2 'fork' The inferior has forked. This is reported when 'catch fork' d38214 4 a38217 4 'vfork' The inferior has vforked. This is reported in when 'catch vfork' (*note Set Catchpoints::) has been used. 'syscall-entry' d38219 2 a38220 2 'catch syscall' (*note Set Catchpoints::) has been used. 'syscall-return' d38222 5 a38226 5 when 'catch syscall' (*note Set Catchpoints::) has been used. 'exec' The inferior called 'exec'. This is reported when 'catch exec' (*note Set Catchpoints::) has been used. 'no-history' d38235 1 a38235 1 STOPPED field will have the value of '"all"'. Otherwise, the value d38243 2 a38244 2 '=thread-group-added,id="ID"' '=thread-group-removed,id="ID"' d38251 1 a38251 1 '=thread-group-started,id="ID",pid="PID"' d38258 1 a38258 1 '=thread-group-exited,id="ID"[,exit-code="CODE"]' d38265 2 a38266 2 '=thread-created,id="ID",group-id="GID"' '=thread-exited,id="ID",group-id="GID"' d38271 1 a38271 1 '=thread-selected,id="ID"[,frame="FRAME"]' d38273 2 a38274 2 notification is not emitted as result of the '-thread-select' or '-stack-select-frame' commands, but is emitted whenever an MI d38277 1 a38277 1 indirectly (via user-defined command), the CLI 'thread' or 'frame' d38290 1 a38290 1 '=library-loaded,...' d38305 1 a38305 1 '=library-unloaded,...' d38308 1 a38308 1 same meaning as for the '=library-loaded' notification. The d38314 2 a38315 2 '=traceframe-changed,num=TFNUM,tracepoint=TPNUM' '=traceframe-changed,end' d38320 1 a38320 1 '=tsv-created,name=NAME,initial=INITIAL' d38324 2 a38325 2 '=tsv-deleted,name=NAME' '=tsv-deleted' d38329 1 a38329 1 '=tsv-modified,name=NAME,initial=INITIAL[,current=CURRENT]' d38335 3 a38337 3 '=breakpoint-created,bkpt={...}' '=breakpoint-modified,bkpt={...}' '=breakpoint-deleted,id=NUMBER' d38349 2 a38350 2 '=record-started,thread-group="ID",method="METHOD"[,format="FORMAT"]' '=record-stopped,thread-group="ID"' d38360 5 a38364 5 '=cmd-param-changed,param=PARAM,value=VALUE' Reports that a parameter of the command 'set PARAM' is changed to VALUE. In the multi-word 'set' command, the PARAM is the whole parameter list to 'set' command. For example, In command 'set check type on', PARAM is 'check type' and VALUE is 'on'. d38366 1 a38366 1 '=memory-changed,thread-group=ID,addr=ADDR,len=LEN[,type="code"]' d38369 1 a38369 1 corresponding to the affected inferior. The optional 'type="code"' d38381 1 a38381 1 'number' d38384 1 a38384 1 'type' d38386 1 a38386 1 'breakpoint', but many values are possible. d38388 2 a38389 2 'catch-type' If the type of the breakpoint is 'catchpoint', then this indicates d38392 3 a38394 3 'disp' This is the breakpoint disposition--either 'del', meaning that the breakpoint will be deleted at the next stop, or 'keep', meaning d38397 1 a38397 1 'enabled' d38399 2 a38400 2 value is 'y', or disabled, in which case the value is 'n'. Note that this is not the same as the field 'enable'. d38402 1 a38402 1 'addr' d38404 2 a38405 2 giving the address; or the string '', for a pending breakpoint; or the string '', for a breakpoint with d38410 1 a38410 1 'addr_flags' d38415 1 a38415 1 'func' d38419 1 a38419 1 'filename' d38423 1 a38423 1 'fullname' d38427 1 a38427 1 'line' d38431 1 a38431 1 'at' d38436 1 a38436 1 'pending' d38440 3 a38442 3 'evaluated-by' Where this breakpoint's condition is evaluated, either 'host' or 'target'. d38444 1 a38444 1 'thread' d38448 1 a38448 1 'inferior' d38452 1 a38452 1 'task' d38456 1 a38456 1 'cond' d38459 1 a38459 1 'ignore' d38462 1 a38462 1 'enable' d38465 1 a38465 1 'traceframe-usage' d38468 1 a38468 1 'static-tracepoint-marker-string-id' d38471 1 a38471 1 'mask' d38474 1 a38474 1 'pass' d38477 1 a38477 1 'original-location' d38481 1 a38481 1 'times' d38484 3 a38486 3 'installed' This field is only given for tracepoints. This is either 'y', meaning that the tracepoint is installed, or 'n', meaning that it d38489 1 a38489 1 'what' d38492 1 a38492 1 'locations' d38503 2 a38504 2 'number' The location number as a dotted pair, like '1.2'. The first digit d38508 1 a38508 1 'enabled' d38510 1 a38510 1 'y' d38512 1 a38512 1 'n' d38514 1 a38514 1 'N' d38518 1 a38518 1 'addr' d38521 1 a38521 1 'addr_flags' d38526 1 a38526 1 'func' d38530 1 a38530 1 'file' d38534 1 a38534 1 'fullname' d38538 1 a38538 1 'line' d38542 1 a38542 1 'thread-groups' d38545 1 a38545 1 For example, here is what the output of '-break-insert' (*note GDB/MI d38564 1 a38564 1 'level' d38568 1 a38568 1 'func' d38572 1 a38572 1 'addr' d38575 1 a38575 1 'addr_flags' d38580 1 a38580 1 'file' d38584 1 a38584 1 'line' d38588 1 a38588 1 'from' d38603 1 a38603 1 'id' d38606 1 a38606 1 'target-id' d38609 1 a38609 1 'details' d38614 1 a38614 1 'name' d38616 1 a38616 1 'thread name' command, then this name is given. Otherwise, if GDB d38621 2 a38622 2 'state' The execution state of the thread, either 'stopped' or 'running', d38625 1 a38625 1 'frame' d38630 1 a38630 1 'core' d38640 1 a38640 1 Whenever a '*stopped' record is emitted because the program stopped d38643 2 a38644 2 'exception-name' field. Also, for exceptions that were raised with an exception message, GDB provides that message via the 'exception-message' d38654 2 a38655 2 the GDB/MI interface. In these examples, '->' means that the following line is passed to GDB/MI as input, while '<-' means the output received d38698 1 a38698 1 Quitting GDB just prints the result class '^exit'. d38704 1 a38704 1 Please note that '^exit' is printed immediately, but it might take d38772 1 a38772 1 The '-break-after' Command d38782 1 a38782 1 '-break-list' command, see the description of the '-break-list' command d38788 1 a38788 1 The corresponding GDB command is 'ignore'. d38817 1 a38817 1 The '-break-commands' Command d38835 1 a38835 1 The corresponding GDB command is 'commands'. d38851 1 a38851 1 The '-break-condition' Command d38860 2 a38861 2 is true. The condition becomes part of the '-break-list' output (see the description of the '-break-list' command below). If the '--force' d38869 1 a38869 1 The corresponding GDB command is 'condition'. d38891 1 a38891 1 The '-break-delete' Command d38905 1 a38905 1 The corresponding GDB command is 'delete'. d38925 1 a38925 1 The '-break-disable' Command d38933 2 a38934 2 Disable the named BREAKPOINT(s). The field 'enabled' in the break list is now set to 'n' for the named BREAKPOINT(s). d38939 1 a38939 1 The corresponding GDB command is 'disable'. d38961 1 a38961 1 The '-break-enable' Command d38974 1 a38974 1 The corresponding GDB command is 'enable'. d38996 1 a38996 1 The '-break-info' Command d39013 1 a39013 1 The corresponding GDB command is 'info break BREAKPOINT'. d39020 1 a39020 1 The '-break-insert' Command d39040 1 a39040 1 '--source FILENAME' d39042 1 a39042 1 the use of either '--function' or '--line'. d39044 1 a39044 1 '--function FUNCTION' d39047 1 a39047 1 '--label LABEL' d39050 1 a39050 1 '--line LINEOFFSET' d39059 1 a39059 1 '-t' d39061 1 a39061 1 '-h' d39063 1 a39063 1 '-f' d39068 1 a39068 1 '-d' d39070 1 a39070 1 '-a' d39072 2 a39073 2 used together with '-h', a fast tracepoint is created. '-c CONDITION' d39075 1 a39075 1 '--force-condition' d39078 1 a39078 1 '-i IGNORE-COUNT' d39080 1 a39080 1 '-p THREAD-ID' d39085 1 a39085 1 '-g THREAD-GROUP-ID' d39088 1 a39088 1 '--qualified' d39103 2 a39104 2 The corresponding GDB commands are 'break', 'tbreak', 'hbreak', and 'thbreak'. d39138 1 a39138 1 The '-dprintf-insert' Command d39153 2 a39154 2 If supplied, LOCSPEC and '--qualified' may be specified the same way as for the '-break-insert' command. *Note -break-insert::. d39158 1 a39158 1 '-t' d39160 1 a39160 1 '-f' d39165 1 a39165 1 '-d' d39167 1 a39167 1 '-c CONDITION' d39169 1 a39169 1 '--force-condition' d39172 1 a39172 1 '-i IGNORE-COUNT' d39175 1 a39175 1 '-p THREAD-ID' d39188 1 a39188 1 The corresponding GDB command is 'dprintf'. d39209 1 a39209 1 The '-break-list' Command d39220 1 a39220 1 'Number' d39222 8 a39229 8 'Type' type of the breakpoint: 'breakpoint' or 'watchpoint' 'Disposition' should the breakpoint be deleted or disabled when it is hit: 'keep' or 'nokeep' 'Enabled' is the breakpoint enabled or no: 'y' or 'n' 'Address' d39231 1 a39231 1 'What' d39234 1 a39234 1 'Thread-groups' d39236 1 a39236 1 'Times' d39240 1 a39240 1 catchpoints, the 'BreakpointTable' 'body' field is an empty list. d39245 1 a39245 1 The corresponding GDB command is 'info break'. d39281 1 a39281 1 The '-break-passcount' Command d39291 1 a39291 1 error is emitted. This corresponds to CLI command 'passcount'. d39293 1 a39293 1 The '-break-watch' Command d39301 1 a39301 1 Create a watchpoint. With the '-a' option it will create an "access" d39303 2 a39304 2 a write to the memory location. With the '-r' option, the watchpoint created is a "read" watchpoint, i.e., it will trigger only when the d39310 1 a39310 1 Note that '-break-list' will report a single list of watchpoints and d39316 1 a39316 1 The corresponding GDB commands are 'watch', 'awatch', and 'rwatch'. d39321 1 a39321 1 Setting a watchpoint on a variable in the 'main' function: d39459 1 a39459 1 The '-catch-load' Command d39467 1 a39467 1 Add a catchpoint for library load events. If the '-t' option is d39469 2 a39470 2 Breaks.). If the '-d' option is used, the catchpoint is created in a disabled state. The 'regexp' argument is a regular expression used to d39476 1 a39476 1 The corresponding GDB command is 'catch load'. d39486 1 a39486 1 The '-catch-unload' Command d39494 1 a39494 1 Add a catchpoint for library unload events. If the '-t' option is d39496 2 a39497 2 Breaks.). If the '-d' option is used, the catchpoint is created in a disabled state. The 'regexp' argument is a regular expression used to d39503 1 a39503 1 The corresponding GDB command is 'catch unload'. d39522 1 a39522 1 The '-catch-assert' Command d39534 1 a39534 1 '-c CONDITION' d39536 1 a39536 1 '-d' d39538 1 a39538 1 '-t' d39544 1 a39544 1 The corresponding GDB command is 'catch assert'. d39556 1 a39556 1 The '-catch-exception' Command d39572 1 a39572 1 '-c CONDITION' d39574 1 a39574 1 '-d' d39576 1 a39576 1 '-e EXCEPTION-NAME' d39578 2 a39579 2 used combined with '-u'. '-t' d39581 1 a39581 1 '-u' d39583 1 a39583 1 cannot be used combined with '-e'. d39588 2 a39589 2 The corresponding GDB commands are 'catch exception' and 'catch exception unhandled'. d39601 1 a39601 1 The '-catch-handlers' Command d39617 1 a39617 1 '-c CONDITION' d39619 1 a39619 1 '-d' d39621 1 a39621 1 '-e EXCEPTION-NAME' d39623 1 a39623 1 '-t' d39629 1 a39629 1 The corresponding GDB command is 'catch handlers'. d39651 1 a39651 1 The '-catch-throw' Command d39663 1 a39663 1 If '-t' is given, then the catchpoint is enabled only for one stop, d39670 1 a39670 1 The corresponding GDB commands are 'catch throw' and 'tcatch throw' d39694 1 a39694 1 The '-catch-rethrow' Command d39706 1 a39706 1 If '-t' is given, then the catchpoint is enabled only for one stop, d39712 1 a39712 1 The corresponding GDB commands are 'catch rethrow' and 'tcatch rethrow' d39736 1 a39736 1 The '-catch-catch' Command d39748 1 a39748 1 If '-t' is given, then the catchpoint is enabled only for one stop, d39754 1 a39754 1 The corresponding GDB commands are 'catch catch' and 'tcatch catch' d39784 1 a39784 1 The '-exec-arguments' Command d39793 1 a39793 1 '-exec-run'. d39798 1 a39798 1 The corresponding GDB command is 'set args'. d39808 1 a39808 1 The '-environment-cd' Command d39821 1 a39821 1 The corresponding GDB command is 'cd'. d39831 1 a39831 1 The '-environment-directory' Command d39840 1 a39840 1 If the '-r' option is used, the search path is reset to the default d39842 1 a39842 1 '-r' option, the search path is first reset and then addition occurs as d39856 1 a39856 1 The corresponding GDB command is 'dir'. d39875 1 a39875 1 The '-environment-path' Command d39884 1 a39884 1 If the '-r' option is used, the search path is reset to the original d39886 1 a39886 1 supplied in addition to the '-r' option, the search path is first reset d39900 1 a39900 1 The corresponding GDB command is 'path'. d39916 1 a39916 1 The '-environment-pwd' Command d39929 1 a39929 1 The corresponding GDB command is 'pwd'. d39945 1 a39945 1 The '-thread-info' Command d39961 1 a39961 1 The 'info thread' command prints the same information about all threads. d39968 1 a39968 1 'threads' d39972 1 a39972 1 'current-thread-id' d39994 1 a39994 1 The '-thread-list-ids' Command d40005 1 a40005 1 This command is retained for historical reasons, the '-thread-info' d40011 1 a40011 1 Part of 'info threads' supplies the same information. d40022 1 a40022 1 The '-thread-select' Command d40035 1 a40035 1 '--thread' option to each command. d40040 1 a40040 1 The corresponding GDB command is 'thread'. d40070 1 a40070 1 The '-ada-task-info' Command d40084 1 a40084 1 The 'info tasks' command prints the same information about all Ada tasks d40093 1 a40093 1 'current' d40095 1 a40095 1 '*'. d40097 1 a40097 1 'id' d40100 1 a40100 1 'task-id' d40103 1 a40103 1 'thread-id' d40111 1 a40111 1 'parent-id' d40115 1 a40115 1 'priority' d40118 1 a40118 1 'state' d40122 1 a40122 1 'name' d40149 1 a40149 1 record '*stopped'. Currently GDB only really executes asynchronously d40152 1 a40152 1 The '-exec-continue' Command d40161 1 a40161 1 execute until it reaches a debugger stop event. If the '--reverse' d40164 4 a40167 4 * breakpoints, watchpoints, tracepoints, or catchpoints * signals or exceptions * the end of the process (or its beginning under '--reverse') * the end or beginning of a replay log if one is being used. d40169 4 a40172 4 or all threads, depending on the value of the 'scheduler-locking' variable. If '--all' is specified, all threads (in all inferiors) will be resumed. The '--all' option is ignored in all-stop mode. If the '--thread-group' options is specified, then all threads in that thread d40178 1 a40178 1 The corresponding GDB corresponding is 'continue'. d40192 3 a40194 3 For a 'breakpoint-hit' stopped reason, when the breakpoint encountered has multiple locations, the field 'bkptno' is followed by the field 'locno'. d40205 1 a40205 1 The '-exec-finish' Command d40215 1 a40215 1 the '--reverse' option is specified, resumes the reverse execution of d40221 1 a40221 1 The corresponding GDB command is 'finish'. d40226 1 a40226 1 Function returning 'void'. d40236 1 a40236 1 Function returning other than 'void'. The name of the internal GDB d40249 1 a40249 1 The '-exec-interrupt' Command d40260 1 a40260 1 only appears in the '^done' output. If the user is trying to interrupt d40265 2 a40266 2 '^done' response will be printed, and the target stop will be reported after that using the '*stopped' notification. d40269 2 a40270 2 All threads (in all inferiors) will be interrupted if the '--all' option is specified. If the '--thread-group' option is specified, all threads d40276 1 a40276 1 The corresponding GDB command is 'interrupt'. d40299 1 a40299 1 The '-exec-jump' Command d40314 1 a40314 1 The corresponding GDB command is 'jump'. d40323 1 a40323 1 The '-exec-next' Command d40334 1 a40334 1 If the '--reverse' option is specified, resumes reverse execution of d40343 1 a40343 1 The corresponding GDB command is 'next'. d40354 1 a40354 1 The '-exec-next-instruction' Command d40367 1 a40367 1 If the '--reverse' option is specified, resumes reverse execution of d40376 1 a40376 1 The corresponding GDB command is 'nexti'. d40390 1 a40390 1 The '-exec-return' Command d40404 1 a40404 1 The corresponding GDB command is 'return'. d40435 1 a40435 1 The '-exec-run' Command d40448 2 a40449 2 When neither the '--all' nor the '--thread-group' option is specified, the current inferior is started. If the '--thread-group' d40451 1 a40451 1 'process', and that thread group will be started. If the '--all' option d40454 1 a40454 1 Using the '--start' option instructs the debugger to stop the d40456 1 a40456 1 same behavior as the 'start' command (*note Starting::). d40461 1 a40461 1 The corresponding GDB command is 'run'. d40499 1 a40499 1 as 'SIGINT'. In this case, GDB/MI displays this: d40505 1 a40505 1 The '-exec-step' Command d40516 1 a40516 1 called function. If the '--reverse' option is specified, resumes d40523 1 a40523 1 The corresponding GDB command is 'step'. d40547 1 a40547 1 The '-exec-step-instruction' Command d40556 1 a40556 1 '--reverse' option is specified, resumes reverse execution of the d40565 1 a40565 1 The corresponding GDB command is 'stepi'. d40588 1 a40588 1 The '-exec-until' Command d40599 1 a40599 1 stopping in this case will be 'location-reached'. d40604 1 a40604 1 The corresponding GDB command is 'until'. d40625 1 a40625 1 The '-enable-frame-filters' Command d40640 1 a40640 1 The '-stack-info-frame' Command d40653 1 a40653 1 The corresponding GDB command is 'info frame' or 'frame' (without d40667 1 a40667 1 The '-stack-info-depth' Command d40705 1 a40705 1 The '-stack-list-arguments' Command d40722 3 a40724 3 If PRINT-VALUES is 0 or '--no-values', print only the names of the variables; if it is 1 or '--all-values', print also their values; and if it is 2 or '--simple-values', print the name, type and value for simple d40726 1 a40726 1 the option '--no-frame-filters' is supplied, then Python frame filters d40729 1 a40729 1 If the '--skip-unavailable' option is specified, arguments that are d40734 1 a40734 1 deprecated in favor of the '-stack-list-variables' command. d40739 1 a40739 1 GDB does not have an equivalent command. 'gdbtk' has a 'gdb_get_args' d40741 1 a40741 1 '-stack-list-arguments'. d40804 1 a40804 1 The '-stack-list-frames' Command d40815 1 a40815 1 'LEVEL' d40818 3 a40820 3 'ADDR' The '$pc' value for that frame. 'FUNC' d40822 1 a40822 1 'FILE' d40824 1 a40824 1 'FULLNAME' d40826 3 a40828 3 'LINE' Line number corresponding to the '$pc'. 'FROM' d40831 1 a40831 1 'ARCH' d40841 1 a40841 1 option '--no-frame-filters' is supplied, then Python frame filters will d40847 1 a40847 1 The corresponding GDB commands are 'backtrace' and 'where'. d40921 1 a40921 1 The '-stack-list-locals' Command d40930 3 a40932 3 PRINT-VALUES is 0 or '--no-values', print only the names of the variables; if it is 1 or '--all-values', print also their values; and if it is 2 or '--simple-values', print the name, type and value for simple d40937 1 a40937 1 '--no-frame-filters' is supplied, then Python frame filters will not be d40940 1 a40940 1 If the '--skip-unavailable' option is specified, local variables that d40944 1 a40944 1 This command is deprecated in favor of the '-stack-list-variables' d40950 1 a40950 1 'info locals' in GDB, 'gdb_get_locals' in 'gdbtk'. d40967 1 a40967 1 The '-stack-list-variables' Command d40976 3 a40978 3 selected frame. If PRINT-VALUES is 0 or '--no-values', print only the names of the variables; if it is 1 or '--all-values', print also their values; and if it is 2 or '--simple-values', print the name, type and d40980 1 a40980 1 structures and unions. If the option '--no-frame-filters' is supplied, d40983 1 a40983 1 If the '--skip-unavailable' option is specified, local variables and d40995 1 a40995 1 The '-stack-select-frame' Command d41006 1 a41006 1 This command in deprecated in favor of passing the '--frame' option d41012 2 a41013 2 The corresponding GDB commands are 'frame', 'up', 'down', 'select-frame', 'up-silent', and 'down-silent'. d41076 1 a41076 1 Variable objects can be either "fixed" or "floating". For the fixed d41092 1 a41092 1 If a fixed variable object for the 'state' variable is created in d41094 1 a41094 1 report the value of 'state' in the top-level 'do_work' invocation. On d41096 1 a41096 1 'state' in the current frame. d41110 3 a41112 3 '-enable-pretty-printing' enable Python-based pretty-printing '-var-create' create a variable object '-var-delete' delete the variable object and/or its d41114 6 a41119 6 '-var-set-format' set the display format of this variable '-var-show-format' show the display format of this variable '-var-info-num-children' tells how many children this object has '-var-list-children' return a list of the object's children '-var-info-type' show the type of this variable object '-var-info-expression' print parent-relative expression that d41121 1 a41121 1 '-var-info-path-expression' print full expression that this variable d41123 1 a41123 1 '-var-show-attributes' is this variable editable? does it exist d41125 5 a41129 5 '-var-evaluate-expression' get the value of this variable '-var-assign' set the value of this variable '-var-update' update the variable and its children '-var-set-frozen' set frozenness attribute '-var-set-update-range' set range of children to display on d41138 1 a41138 1 The '-enable-pretty-printing' Command d41153 1 a41153 1 The '-var-create' Command d41167 1 a41167 1 referenced. It must be unique. If '-' is specified, the varobj system d41173 2 a41174 2 specified by FRAME-ADDR. A '*' indicates that the current frame should be used. A '@@' indicates that a floating variable object must be d41178 1 a41178 1 not begin with a '*'), or one of the following: d41180 1 a41180 1 * '*ADDR', where ADDR is the address of a memory cell d41182 1 a41182 1 * '*ADDR-ADDR' -- a memory address range (TBD) d41184 1 a41184 1 * '$REGNAME' -- a CPU register name d41187 1 a41187 1 In this case the varobj is known as a "dynamic varobj". Dynamic varobjs d41189 1 a41189 1 '-enable-pretty-printing' command is not sent, then GDB will never d41199 1 a41199 1 'name' d41202 1 a41202 1 'numchild' d41205 1 a41205 1 examine the 'has_more' attribute. d41207 1 a41207 1 'value' d41209 1 a41209 1 aggregate (e.g., a 'struct'), this value will not be interesting. d41211 1 a41211 1 pretty-printer object's 'to_string' method. d41213 1 a41213 1 'type' d41215 2 a41216 2 would be printed by the GDB CLI. If 'print object' (*note set print object: Print Settings.) is set to 'on', the _actual_ (derived) d41219 1 a41219 1 'thread-id' d41223 1 a41223 1 'has_more' d41227 2 a41228 2 'dynamic' This attribute will be present and have the value '1' if the varobj d41232 1 a41232 1 'displayhint' d41235 1 a41235 1 'display_hint' method. *Note Pretty Printing API::. d41242 1 a41242 1 The '-var-delete' Command d41251 1 a41251 1 With the '-c' option, just deletes the children. d41255 1 a41255 1 The '-var-set-format' Command d41268 1 a41268 1 FORMAT-SPEC ==> d41272 1 a41272 1 on the variable type (like decimal for an 'int', hex for pointers, d41283 1 a41283 1 The '-var-show-format' Command d41293 1 a41293 1 FORMAT ==> d41296 1 a41296 1 The '-var-info-num-children' Command d41312 1 a41312 1 The '-var-list-children' Command d41322 1 a41322 1 single argument or if PRINT-VALUES has a value of 0 or '--no-values', d41324 2 a41325 2 '--all-values', also print their values; and if it is 2 or '--simple-values' print the name and value for simple data types and d41334 2 a41335 2 to '-var-list-children', but not future calls to '-var-update'. For this, you must instead use '-var-set-update-range'. The intent of this d41338 2 a41339 2 more children with '-var-list-children', and then the front end could call '-var-set-update-range' with a different range to ensure that d41358 1 a41358 1 'public', 'private', or 'protected'. In this case the type and d41370 2 a41371 2 The type of the child. If 'print object' (*note set print object: Print Settings.) is set to 'on', the _actual_ (derived) type of the d41388 1 a41388 1 'display_hint' method. *Note Pretty Printing API::. d41391 1 a41391 1 This attribute will be present and have the value '1' if the varobj d41397 1 a41397 1 'displayhint' d41400 1 a41400 1 'display_hint' method. *Note Pretty Printing API::. d41402 1 a41402 1 'has_more' d41418 1 a41418 1 The '-var-info-type' Command d41431 1 a41431 1 The '-var-info-expression' Command d41443 2 a41444 2 For example, if 'a' is an array, and variable object 'A' was created for 'a', then we'll get this output: d41449 1 a41449 1 Here, the value of 'lang' is the language name, which can be found in d41452 2 a41453 2 Note that the output of the '-var-list-children' command also includes those expressions, so the '-var-info-expression' command is of d41456 1 a41456 1 The '-var-info-path-expression' Command d41466 2 a41467 2 with the '-var-info-expression' command, which result can be used only for UI presentation. Typical use of the '-var-info-path-expression' d41473 4 a41476 4 For example, suppose 'C' is a C++ class, derived from class 'Base', and that the 'Base' class has a member called 'm_size'. Assume a variable 'c' is has the type of 'C' and a variable object 'C' was created for variable 'c'. Then, we'll get this output: d41480 1 a41480 1 The '-var-show-attributes' Command d41492 1 a41492 1 where ATTR is '{ { editable | noneditable } | TBD }'. d41494 1 a41494 1 The '-var-evaluate-expression' Command d41504 3 a41506 3 string can be specified with the '-f' option. The possible values of this option are the same as for '-var-set-format' (*note -var-set-format::). If the '-f' option is not specified, the current d41508 1 a41508 1 using the '-var-set-format' command. d41512 1 a41512 1 Note that one must invoke '-var-list-children' for a variable before d41515 1 a41515 1 The '-var-assign' Command d41524 1 a41524 1 NAME. The object must be 'editable'. If the variable's value is d41526 1 a41526 1 '-var-update' list. d41539 1 a41539 1 The '-var-update' Command d41551 2 a41552 2 '-var-evaluate-expression' before and after the '-var-update' is different. If '*' is used as the variable object names, all existing d41556 2 a41557 2 this option are the same as for '-var-list-children' (*note -var-list-children::). It is recommended to use the '--all-values' d41560 1 a41560 1 With the '*' parameter, if a variable object is bound to a currently d41563 1 a41563 1 If '-var-set-update-range' was previously used on a varobj, then only d41566 2 a41567 2 '-var-update' reports all the changed varobjs in a tuple named 'changelist'. d41571 1 a41571 1 'name' d41574 1 a41574 1 'value' d41578 1 a41578 1 'in_scope' d41581 1 a41581 1 '"true"' d41584 1 a41584 1 '"false"' d41589 1 a41589 1 '"invalid"' d41592 1 a41592 1 either through recompilation or by using the GDB 'file' d41600 1 a41600 1 'type_changed' d41602 2 a41603 2 changed, then this will be the string 'true'; otherwise it will be 'false'. d41607 2 a41608 2 automatically deleted when this attribute is 'true'. Also, the varobj's update range, when set using the '-var-set-update-range' d41611 1 a41611 1 'new_type' d41615 1 a41615 1 'new_num_children' d41619 1 a41619 1 The 'numchild' field in other varobj responses is generally not d41625 1 a41625 1 The 'new_num_children' attribute only reports changes to the number d41630 1 a41630 1 'displayhint' d41633 1 a41633 1 'has_more' d41637 2 a41638 2 'dynamic' This attribute will be present and have the value '1' if the varobj d41642 1 a41642 1 'new_children' d41644 1 a41644 1 update range (as set by '-var-set-update-range'), then they will be d41659 1 a41659 1 The '-var-set-frozen' Command d41668 1 a41668 1 parameter should be either '1' to make the variable frozen or '0' to d41670 2 a41671 2 nor any of its children, are implicitly updated by '-var-update' of a parent variable or by '-var-update *'. Only '-var-update' of the d41674 2 a41675 2 subsequent '-var-update' operations. Unfreezing a variable does not update it, only subsequent '-var-update' does. d41685 1 a41685 1 The '-var-set-update-range' command d41694 1 a41694 1 '-var-update'. d41708 1 a41708 1 The '-var-set-visualizer' command d41718 1 a41718 1 VISUALIZER is the visualizer to use. The special value 'None' means d41721 1 a41721 1 If not 'None', VISUALIZER must be a Python expression. This d41729 1 a41729 1 The pre-defined function 'gdb.default_visualizer' may be used to d41735 1 a41735 1 command '-list-features' (*note GDB/MI Support Commands::) can be used d41753 1 a41753 1 Suppose 'SomeClass' is a visualizer class. A lambda expression can d41772 1 a41772 1 The '-data-disassemble' Command d41788 3 a41790 3 'START-ADDR' is the beginning address (or '$pc') 'END-ADDR' d41792 1 a41792 1 'ADDR' d41797 1 a41797 1 'FILENAME' d41799 1 a41799 1 'LINENUM' d41801 1 a41801 1 'LINES' d41809 1 a41809 1 'OPCODES-MODE' d41811 1 a41811 1 'none' d41814 1 a41814 1 'bytes' d41816 1 a41816 1 formatted as for 'disassemble /b'. d41818 1 a41818 1 'display' d41820 4 a41823 4 formatted as for 'disassemble /r'. 'MODE' the use of MODE is deprecated in favour of using the '--opcodes' and '--source' options. When no MODE is given, MODE 0 will be d41826 1 a41826 1 '0' d41830 1 a41830 1 '1' d41832 2 a41833 2 possible to recreate this mode using '--opcodes' and '--source' options. d41835 1 a41835 1 '2' d41837 1 a41837 1 using MODE 0 and passing '--opcodes bytes' to the command. d41839 1 a41839 1 '3' d41841 2 a41842 2 it is not possible to recreate this mode using '--opcodes' and '--source' options. d41844 1 a41844 1 '4' d41846 1 a41846 1 using MODE 0 and passing '--source' to the command. d41848 1 a41848 1 '5' d41850 2 a41851 2 equivalent to using MODE 0 and passing '--opcodes bytes' and '--source' to the command. d41854 2 a41855 2 discussion of the difference between '/m' and '/s' output of the 'disassemble' command. d41857 1 a41857 1 The '--source' can only be used with MODE 0. Passing this option d41864 3 a41866 3 The result of the '-data-disassemble' command will be a list named 'asm_insns', the contents of this list depend on the options used with the '-data-disassemble' command. d41868 2 a41869 2 For modes 0 and 2, and when the '--source' option is not used, the 'asm_insns' list contains tuples with the following fields: d41871 1 a41871 1 'address' d41874 1 a41874 1 'func-name' d41877 2 a41878 2 'offset' The decimal offset in bytes from the start of 'func-name'. d41880 2 a41881 2 'inst' The text disassembly for this 'address'. d41883 1 a41883 1 'opcodes' d41885 2 a41886 2 '--opcodes' option 'bytes' or 'display' is used. This contains the raw opcode bytes for the 'inst' field. d41888 2 a41889 2 When the '--opcodes' option is not passed to '-data-disassemble', or the 'bytes' value is passed to '--opcodes', then the bytes are d41892 2 a41893 2 equivalent to the '/b' option being used with the 'disassemble' command (*note 'disassemble': disassemble.). d41895 1 a41895 1 When '--opcodes' is passed the value 'display' then the bytes are d41898 2 a41899 2 byte-swapped. This format is equivalent to the '/r' option being used with the 'disassemble' command. d41901 2 a41902 2 For modes 1, 3, 4 and 5, or when the '--source' option is used, the 'asm_insns' list contains tuples named 'src_and_asm_line', each of which d41905 2 a41906 2 'line' The line number within 'file'. d41908 1 a41908 1 'file' d41913 2 a41914 2 'fullname' Absolute file name of 'file'. It is converted to a canonical form d41922 5 a41926 5 'line_asm_insn' This is a list of tuples containing the disassembly for 'line' in 'file'. The fields of each tuple are the same as for '-data-disassemble' in MODE 0 and 2, so 'address', 'func-name', 'offset', 'inst', and optionally 'opcodes'. d41928 1 a41928 1 Note that whatever included in the 'inst' field, is not manipulated d41934 1 a41934 1 The corresponding GDB command is 'disassemble'. d41939 1 a41939 1 Disassemble from the current value of '$pc' to '$pc + 20': d41957 1 a41957 1 Disassemble the whole 'main' function. Line 32 is part of 'main'. d41972 1 a41972 1 Disassemble 3 instructions from the start of 'main': d41985 1 a41985 1 Disassemble 3 instructions from the start of 'main' in mixed mode: d42004 1 a42004 1 The '-data-evaluate-expression' Command d42019 2 a42020 2 The corresponding GDB commands are 'print', 'output', and 'call'. In 'gdbtk' only, there's a corresponding 'gdb_eval' command. d42026 1 a42026 1 "tokens" described in *note GDB/MI Command Syntax: GDB/MI Command d42042 1 a42042 1 The '-data-list-changed-registers' Command d42055 2 a42056 2 GDB doesn't have a direct analog for this command; 'gdbtk' has the corresponding command 'gdb_changed_register_list'. d42078 1 a42078 1 The '-data-list-register-names' Command d42097 2 a42098 2 '-data-list-register-names'. In 'gdbtk' there is a corresponding command 'gdb_regnames'. d42118 1 a42118 1 The '-data-list-register-values' Command d42131 1 a42131 1 returned. The '--skip-unavailable' option indicates that only the d42136 1 a42136 1 'x' d42138 1 a42138 1 'o' d42140 1 a42140 1 't' d42142 1 a42142 1 'd' d42144 1 a42144 1 'r' d42146 1 a42146 1 'N' d42152 2 a42153 2 The corresponding GDB commands are 'info reg', 'info all-reg', and (in 'gdbtk') 'gdb_fetch_registers'. d42205 1 a42205 1 The '-data-read-memory' Command d42208 1 a42208 1 This command is deprecated, use '-data-read-memory-bytes' instead. d42219 1 a42219 1 'ADDRESS' d42224 1 a42224 1 'WORD-FORMAT' d42226 1 a42226 1 the same as for GDB's 'print' command (*note Output Formats: Output d42229 1 a42229 1 'WORD-SIZE' d42232 1 a42232 1 'NR-ROWS' d42235 1 a42235 1 'NR-COLS' d42238 1 a42238 1 'ASCHAR' d42245 1 a42245 1 'BYTE-OFFSET' d42249 2 a42250 2 NR-COLS words, each word being WORD-SIZE bytes. In total, 'NR-ROWS * NR-COLS * WORD-SIZE' bytes are read (returned as 'total-bytes'). Should d42252 3 a42254 3 missing words are identified using 'N/A'. The number of bytes read from the target is returned in 'nr-bytes' and the starting address used to read memory in 'addr'. d42257 1 a42257 1 'next-row' and 'prev-row', 'next-page' and 'prev-page'. d42262 1 a42262 1 The corresponding GDB command is 'x'. 'gdbtk' has 'gdb_get_mem' memory d42268 1 a42268 1 Read six bytes of memory starting at 'bytes+6' but then offset by '-6' d42282 1 a42282 1 Read two bytes of memory starting at address 'shorts + 64' and d42293 2 a42294 2 Read thirty two bytes of memory starting at 'bytes+16' and format as eight rows of four columns. Include a string encoding with 'x' used as d42312 1 a42312 1 The '-data-read-memory-bytes' Command d42323 1 a42323 1 'ADDRESS' d42328 1 a42328 1 'COUNT' d42332 1 a42332 1 'OFFSET' d42355 1 a42355 1 the command includes a field named 'memory' whose content is a list of d42359 1 a42359 1 'begin' d42362 1 a42362 1 'end' d42365 1 a42365 1 'offset' d42367 1 a42367 1 the start address passed to '-data-read-memory-bytes'. d42369 1 a42369 1 'contents' d42375 1 a42375 1 The corresponding GDB command is 'x'. d42387 1 a42387 1 The '-data-write-memory-bytes' Command d42398 1 a42398 1 'ADDRESS' d42403 1 a42403 1 'CONTENTS' d42407 1 a42407 1 'COUNT' d42439 1 a42439 1 The '-trace-find' Command d42451 1 a42451 1 'none' d42454 1 a42454 1 'frame-number' d42458 1 a42458 1 'tracepoint-number' d42462 1 a42462 1 'pc' d42466 1 a42466 1 'pc-inside-range' d42471 1 a42471 1 'pc-outside-range' d42477 1 a42477 1 'line' d42482 1 a42482 1 If 'none' was passed as MODE, the response does not have fields. d42485 2 a42486 2 'found' This field has either '0' or '1' as the value, depending on whether d42489 1 a42489 1 'traceframe' d42491 1 a42491 1 'found' field has value of '1'. d42493 1 a42493 1 'tracepoint' d42495 1 a42495 1 'found' field has value of '1'. d42497 1 a42497 1 'frame' d42505 1 a42505 1 The corresponding GDB command is 'tfind'. d42507 1 a42507 1 The '-trace-define-variable' Command d42517 1 a42517 1 that value. Note that the NAME should start with the '$' character. d42522 1 a42522 1 The corresponding GDB command is 'tvariable'. d42524 1 a42524 1 The '-trace-frame-collected' Command d42552 3 a42554 3 the object collected in its entirety would be 'myVar'. The object 'myArray' would be partially collected, because only the element at index 'myIndex' would be collected. The remaining objects would be d42580 1 a42580 1 'explicit-variables' d42584 1 a42584 1 The '--var-print-values' option affects how or whether the value d42590 1 a42590 1 'computed-expressions' d42592 3 a42594 3 current trace frame. The '--comp-print-values' option affects this set like the '--var-print-values' option affects the 'explicit-variables' set. See above. d42596 1 a42596 1 'registers' d42600 2 a42601 2 '--registers-format' option. See the '-data-list-register-values' command for a list of the allowed formats. The default is 'x'. d42603 1 a42603 1 'tvars' d42608 1 a42608 1 'memory' d42613 1 a42613 1 'address' d42616 1 a42616 1 'length' d42619 1 a42619 1 'contents' d42621 1 a42621 1 present if the '--memory-contents' option is specified. d42631 1 a42631 1 The '-trace-list-variables' Command d42642 1 a42642 1 'name' d42645 1 a42645 1 'initial' d42649 1 a42649 1 'current' d42658 1 a42658 1 The corresponding GDB command is 'tvariables'. d42673 1 a42673 1 The '-trace-save' Command d42681 1 a42681 1 Saves the collected trace data to FILENAME. Without the '-r' option, d42683 1 a42683 1 the '-r' option the target is asked to perform the save. d42686 1 a42686 1 You can supply the optional '-ctf' argument to save it the CTF format. d42692 1 a42692 1 The corresponding GDB command is 'tsave'. d42694 1 a42694 1 The '-trace-start' Command d42708 1 a42708 1 The corresponding GDB command is 'tstart'. d42710 1 a42710 1 The '-trace-status' Command d42721 4 a42724 4 'supported' May have a value of either '0', when no tracing operations are supported, '1', when all tracing operations are supported, or 'file' when examining trace file. In the latter case, examining of d42728 2 a42729 2 'running' May have a value of either '0' or '1' depending on whether tracing d42731 1 a42731 1 'supported' field is not '0'. d42733 1 a42733 1 'stop-reason' d42736 3 a42738 3 The value of 'request' means the tracing was stopped as result of the '-trace-stop' command. The value of 'overflow' means the tracing buffer is full. The value of 'disconnection' means tracing d42740 1 a42740 1 'passcount' means tracing was stopped when a tracepoint was passed d42742 1 a42742 1 present if 'supported' field is not '0'. d42744 1 a42744 1 'stopping-tracepoint' d42746 2 a42747 2 is present iff the 'stop-reason' field has the value of 'passcount'. d42749 4 a42752 4 'frames' 'frames-created' The 'frames' field is a count of the total number of trace frames in the trace buffer, while 'frames-created' is the total created d42756 2 a42757 2 'buffer-size' 'buffer-free' d42761 2 a42762 2 'circular' The value of the circular trace buffer flag. '1' means that the d42764 1 a42764 1 necessary to make room, '0' means that the trace buffer is linear d42767 3 a42769 3 'disconnected' The value of the disconnected tracing flag. '1' means that tracing will continue after GDB disconnects, '0' means that the trace run d42772 1 a42772 1 'trace-file' d42779 1 a42779 1 The corresponding GDB command is 'tstatus'. d42781 1 a42781 1 The '-trace-stop' Command d42790 1 a42790 1 fields as '-trace-status', except that the 'supported' and 'running' d42796 1 a42796 1 The corresponding GDB command is 'tstop'. d42804 1 a42804 1 The '-symbol-info-functions' Command d42819 1 a42819 1 The '--include-nondebug' option causes the output to include code d42822 1 a42822 1 The options '--type' and '--name' allow the symbols returned to be d42826 1 a42826 1 The option '--max-results' restricts the command to return no more d42833 1 a42833 1 The corresponding GDB command is 'info functions'. d42904 1 a42904 1 The '-symbol-info-module-functions' Command d42919 3 a42921 3 The option '--module' only returns results for modules matching MODULE_REGEXP. The option '--name' only returns functions whose name matches NAME_REGEXP, and '--type' only returns functions whose type d42927 1 a42927 1 The corresponding GDB command is 'info module functions'. d42965 1 a42965 1 The '-symbol-info-module-variables' Command d42980 3 a42982 3 The option '--module' only returns results for modules matching MODULE_REGEXP. The option '--name' only returns variables whose name matches NAME_REGEXP, and '--type' only returns variables whose type d42988 1 a42988 1 The corresponding GDB command is 'info module variables'. d43036 1 a43036 1 The '-symbol-info-modules' Command d43050 1 a43050 1 The option '--name' allows the modules returned to be filtered based d43053 1 a43053 1 The option '--max-results' restricts the command to return no more d43060 1 a43060 1 The corresponding GDB command is 'info modules'. d43090 1 a43090 1 The '-symbol-info-types' Command d43103 2 a43104 2 added to the debug information by the compiler, for example 'int', 'float', etc.; these types do not have an associated line number. d43106 1 a43106 1 The option '--name' allows the list of types returned to be filtered d43109 1 a43109 1 The option '--max-results' restricts the command to return no more d43116 1 a43116 1 The corresponding GDB command is 'info types'. d43147 1 a43147 1 The '-symbol-info-variables' Command d43163 1 a43163 1 The '--include-nondebug' option causes the output to include data d43166 1 a43166 1 The options '--type' and '--name' allow the symbols returned to be d43170 1 a43170 1 The option '--max-results' restricts the command to return no more d43177 1 a43177 1 The corresponding GDB command is 'info variables'. d43252 1 a43252 1 The '-symbol-list-lines' Command d43286 1 a43286 1 The '-file-exec-and-symbols' Command d43304 1 a43304 1 The corresponding GDB command is 'file'. d43314 1 a43314 1 The '-file-exec-file' Command d43323 1 a43323 1 '-file-exec-and-symbols', the symbol table is _not_ read from this file. d43331 1 a43331 1 The corresponding GDB command is 'exec-file'. d43341 1 a43341 1 The '-file-list-exec-source-file' Command d43351 1 a43351 1 information field has a value of '1' or '0' depending on whether or not d43357 1 a43357 1 The GDB equivalent is 'info source' d43367 1 a43367 1 The '-file-list-exec-source-files' Command d43388 3 a43390 3 field DEBUG-FULLY-READ will be a string, either 'true' or 'false'. When 'true', this indicates the full debug information for the compilation unit describing this file has been read in. When 'false', the full d43398 1 a43398 1 case-insensitive filesystem (e.g., MS-Windows). '--' can be used before d43400 1 a43400 1 REGEXP starts with '-'). d43402 2 a43403 2 If '--dirname' is provided, then REGEXP is matched only against the directory name of each source file. If '--basename' is provided, then d43405 1 a43405 1 '--dirname' or '--basename' may be given, and if either is given then d43408 1 a43408 1 If '--group-by-objfile' is used then the format of the results is d43415 1 a43415 1 'none' d43417 1 a43417 1 'partially-read' d43421 1 a43421 1 'fully-read' d43432 2 a43433 2 The GDB equivalent is 'info sources'. 'gdbtk' has an analogous command 'gdb_listfiles'. d43499 1 a43499 1 The '-file-list-shared-libraries' Command d43513 2 a43514 2 The corresponding GDB command is 'info shared'. The fields have a similar meaning to the '=library-loaded' notification. The 'ranges' d43518 1 a43518 1 'from' d43520 1 a43520 1 'to' d43533 1 a43533 1 The '-file-symbol-file' Command d43548 1 a43548 1 The corresponding GDB command is 'symbol-file'. d43564 1 a43564 1 The '-target-attach' Command d43574 1 a43574 1 by '-list-thread-groups --available' must be used. d43579 1 a43579 1 The corresponding GDB command is 'attach'. d43591 1 a43591 1 The '-target-detach' Command d43606 1 a43606 1 The corresponding GDB command is 'detach'. d43616 1 a43616 1 The '-target-disconnect' Command d43630 1 a43630 1 The corresponding GDB command is 'disconnect'. d43640 1 a43640 1 The '-target-download' Command d43651 1 a43651 1 'section' d43653 1 a43653 1 'section-sent' d43655 1 a43655 1 'section-size' d43657 1 a43657 1 'total-sent' d43660 1 a43660 1 'total-size' d43669 1 a43669 1 'section' d43671 1 a43671 1 'section-size' d43673 1 a43673 1 'total-size' d43681 1 a43681 1 The corresponding GDB command is 'load'. d43747 1 a43747 1 The '-target-flash-erase' Command d43757 1 a43757 1 The corresponding GDB command is 'flash-erase'. d43767 1 a43767 1 The '-target-select' Command d43777 3 a43779 3 'TYPE' The type of target, for instance 'remote', etc. 'PARAMETERS' d43792 1 a43792 1 The corresponding GDB command is 'target'. d43808 1 a43808 1 The '-target-file-put' Command d43822 1 a43822 1 The corresponding GDB command is 'remote put'. d43832 1 a43832 1 The '-target-file-get' Command d43846 1 a43846 1 The corresponding GDB command is 'remote get'. d43856 1 a43856 1 The '-target-file-delete' Command d43869 1 a43869 1 The corresponding GDB command is 'remote delete'. d43885 1 a43885 1 The '-info-ada-exceptions' Command d43900 1 a43900 1 The corresponding GDB command is 'info exceptions'. d43908 1 a43908 1 'name' d43911 1 a43911 1 'address' d43942 1 a43942 1 The '-info-gdb-mi-command' Command d43952 1 a43952 1 Note that the dash ('-') starting all GDB/MI commands is technically d43967 3 a43969 3 'exists' This field is equal to '"true"' if the GDB/MI command exists, '"false"' otherwise. d43985 1 a43985 1 The '-list-features' Command d44006 6 a44011 6 'frozen-varobjs' Indicates support for the '-var-set-frozen' command, as well as possible presence of the 'frozen' field in the output of '-varobj-create'. 'pending-breakpoints' Indicates support for the '-f' option to the '-break-insert' d44013 1 a44013 1 'python' d44015 8 a44022 8 commands, and possible presence of the 'display_hint' field in the output of '-var-list-children' 'thread-info' Indicates support for the '-thread-info' command. 'data-read-memory-bytes' Indicates support for the '-data-read-memory-bytes' and the '-data-write-memory-bytes' commands. 'breakpoint-notifications' d44025 4 a44028 4 'ada-task-info' Indicates support for the '-ada-task-info' command. 'language-option' Indicates that all GDB/MI commands accept the '--language' option d44030 3 a44032 3 'info-gdb-mi-command' Indicates support for the '-info-gdb-mi-command' command. 'undefined-command-error-code' d44036 2 a44037 2 'exec-run-start-option' Indicates that the '-exec-run' command supports the '--start' d44039 2 a44040 2 'data-disassemble-a-option' Indicates that the '-data-disassemble' command supports the '-a' d44042 4 a44045 4 'simple-values-ref-types' Indicates that the '--simple-values' argument to the '-stack-list-arguments', '-stack-list-locals', '-stack-list-variables', and '-var-list-children' commands takes d44050 1 a44050 1 The '-list-target-features' Command d44055 1 a44055 1 reported by the '-list-features' command, the features depend on which d44057 1 a44057 1 commands such as '-target-select', '-target-attach' or '-exec-run', the d44066 1 a44066 1 'async' d44071 1 a44071 1 'reverse' d44081 1 a44081 1 The '-gdb-exit' Command d44094 1 a44094 1 Approximately corresponds to 'quit'. d44103 1 a44103 1 The '-gdb-set' Command d44116 1 a44116 1 The corresponding GDB command is 'set'. d44126 1 a44126 1 The '-gdb-show' Command d44139 1 a44139 1 The corresponding GDB command is 'show'. d44149 1 a44149 1 The '-gdb-version' Command d44162 1 a44162 1 The GDB equivalent is 'show version'. GDB by default shows this d44183 1 a44183 1 The '-list-thread-groups' Command d44198 1 a44198 1 the '--available' option, GDB reports thread groups available on the d44201 2 a44202 2 The output of this command may have either a 'threads' result or a 'groups' result. The 'thread' result has a list of tuples as value, d44204 1 a44204 1 The 'groups' result has a list of tuples as value, each tuple describing d44207 1 a44207 1 always has a 'groups' result. The format of the 'group' result is d44211 1 a44211 1 groups together with their children, by passing the '--recurse' option d44214 1 a44214 1 will also include its children, either as 'group' or 'threads' field. d44219 3 a44221 3 * When a single thread group is passed, the output will typically be the 'threads' result. Because threads may not contain anything, the 'recurse' option will be ignored. d44223 1 a44223 1 * When the '--available' option is passed, limited information may be d44227 1 a44227 1 The frontend should assume that '-list-thread-groups --available' d44230 1 a44230 1 The 'groups' result is a list of tuples, where each tuple may have d44233 1 a44233 1 'id' d44238 2 a44239 2 'type' The type of the thread group. At present, only 'process' is a d44242 1 a44242 1 'pid' d44244 1 a44244 1 for thread groups of type 'process' and only if the process exists. d44246 1 a44246 1 'exit-code' d44249 1 a44249 1 'process' and only if the process is not running. d44251 1 a44251 1 'num_children' d44255 1 a44255 1 'threads' d44257 1 a44257 1 thread. It may be present if the '--recurse' option is specified, d44260 1 a44260 1 'cores' d44265 1 a44265 1 'executable' d44268 1 a44268 1 'process', and only if there is a corresponding executable file. d44293 1 a44293 1 The '-info-os' Command d44312 1 a44312 1 The corresponding GDB command is 'info os'. d44361 2 a44362 2 (Note that the MI output here includes a '"Title"' column that does not appear in command-line 'info os'; this column is useful for MI d44364 1 a44364 1 menu, but is needless clutter on the command line, and 'info os' omits d44367 1 a44367 1 The '-add-inferior' Command d44377 1 a44377 1 association may be established with the '-file-exec-and-symbols' command d44382 5 a44386 5 inferior was connected to 'gdbserver' with 'target remote', then the new inferior will be connected to the same 'gdbserver' instance. The '--no-connection' option starts the new inferior with no connection yet. You can then for example use the '-target-select remote' command to connect to some other 'gdbserver' instance, use '-exec-run' to spawn a d44397 1 a44397 1 'number' d44400 1 a44400 1 'name' d44406 1 a44406 1 The corresponding GDB command is 'add-inferior' (*note 'add-inferior': d44416 1 a44416 1 The '-remove-inferior' Command d44427 1 a44427 1 the '-add-inferior' command. d44429 1 a44429 1 When an inferior is successfully removed a '=thread-group-removed' d44436 2 a44437 2 The corresponding GDB command is 'remove-inferiors' (*note 'remove-inferiors': remove_inferiors_cli.). d44447 1 a44447 1 The '-interpreter-exec' Command d44460 1 a44460 1 The corresponding GDB command is 'interpreter-exec'. d44473 1 a44473 1 The '-inferior-tty-set' Command d44486 1 a44486 1 The corresponding GDB command is 'set inferior-tty' /dev/pts/1. d44496 1 a44496 1 The '-inferior-tty-show' Command d44509 1 a44509 1 The corresponding GDB command is 'show inferior-tty'. d44522 1 a44522 1 The '-enable-timings' Command d44533 1 a44533 1 equivalent to 'yes'. d44566 1 a44566 1 The '-complete' Command d44585 1 a44585 1 'completion' d44589 1 a44589 1 'matches' d44593 4 a44596 4 'max_completions_reached' This field contains '1' if number of known completions is above 'max-completions' limit (*note Completion::), otherwise it contains '0'. It is always present. d44601 1 a44601 1 The corresponding GDB command is 'complete'. d44659 1 a44659 1 Annotations start with a newline character, two 'control-z' characters, d44667 1 a44667 1 Any output not beginning with a newline and two 'control-z' d44669 1 a44669 1 for GDB to output a newline followed by two 'control-z' characters, but d44671 1 a44671 1 'escape' annotation which means those three characters as output. d44673 1 a44673 1 The annotation LEVEL, which is specified using the '--annotate' d44682 2 a44683 2 'set annotate LEVEL' The GDB command 'set annotate' sets the level of annotations to the d44686 1 a44686 1 'show annotate' d44712 2 a44713 2 Here 'quit' is input to GDB; the rest is output from GDB. The three lines beginning '^Z^Z' (where '^Z' denotes a 'control-z' character) are d44722 1 a44722 1 If you prefix a command with 'server ' then it will not affect the d44728 1 a44728 1 The 'server ' prefix does not affect the recording of values into the d44730 1 a44730 1 history, use the 'output' command instead of the 'print' command. d44745 2 a44746 2 Different kinds of input each have a different "input type". Each input type has three annotations: a 'pre-' annotation, which denotes the d44748 1 a44748 1 denotes the end of the prompt, and then a 'post-' annotation which d44750 1 a44750 1 the input. For example, the 'prompt' input type features the following d44759 1 a44759 1 'prompt' d44762 2 a44763 2 'commands' When GDB prompts for a set of commands, like in the 'commands' d44767 1 a44767 1 'overload-choice' d44771 1 a44771 1 'query' d44775 1 a44775 1 'prompt-for-continue' d44777 1 a44777 1 Don't expect this to work well; instead use 'set height 0' to d44797 2 a44798 2 'value-history-begin' annotation is followed by a 'error', one cannot expect to receive the matching 'value-history-end'. One cannot expect d44821 1 a44821 1 '^Z^Zframes-invalid' d44823 1 a44823 1 The frames (for example, output from the 'backtrace' command) may d44826 1 a44826 1 '^Z^Zbreakpoints-invalid' d44837 2 a44838 2 When the program starts executing due to a GDB command such as 'step' or 'continue', d44846 1 a44846 1 is output. Before the 'stopped' annotation, a variety of annotations d44849 1 a44849 1 '^Z^Zexited EXIT-STATUS' d44853 2 a44854 2 '^Z^Zsignalled' The program exited with a signal. After the '^Z^Zsignalled', the d44867 3 a44869 3 where NAME is the name of the signal, such as 'SIGILL' or 'SIGSEGV', and STRING is the explanation of the signal, such as 'Illegal Instruction' or 'Segmentation fault'. The arguments d44873 2 a44874 2 '^Z^Zsignal' The syntax of this annotation is just like 'signalled', but GDB is d44878 1 a44878 1 '^Z^Zbreakpoint NUMBER' d44881 1 a44881 1 '^Z^Zwatchpoint NUMBER' d44898 2 a44899 2 necessarily point to the beginning of a line), MIDDLE is 'middle' if ADDR is in the middle of the line, or 'beg' if ADDR is at the beginning d44901 1 a44901 1 with the source which is being displayed. The ADDR is in the form '0x' d44918 1 a44918 1 GDB defines some parameters that can be passed to the 'launch' d44921 1 a44921 1 'args' d44923 2 a44924 2 provided as command-line arguments to the inferior, as if by 'set args'. *Note Arguments::. d44926 1 a44926 1 'cwd' d44928 1 a44928 1 directory to this directory, as if by the 'cd' command (*note d44931 2 a44932 2 before the 'program' parameter is processed. This will affect the result if 'program' is a relative filename. d44934 1 a44934 1 'env' d44941 1 a44941 1 'program' d44943 1 a44943 1 This corresponds to the 'file' command. *Note Files::. d44945 2 a44946 2 'stopAtBeginningOfMainSubprogram' If provided, this must be a boolean. When 'True', GDB will set a d44948 1 a44948 1 same approach as the 'start' command. *Note Starting::. d44950 3 a44952 3 GDB defines some parameters that can be passed to the 'attach' request. Either 'pid' or 'target' must be specified, but if both are specified then 'target' will be ignored. d44954 1 a44954 1 'pid' d44957 1 a44957 1 'program' d44959 1 a44959 1 This corresponds to the 'file' command. *Note Files::. In some d44964 1 a44964 1 'target' d44966 1 a44966 1 passed to the 'target remote' command. *Note Connecting::. d44968 1 a44968 1 In response to the 'disassemble' request, DAP allows the client to d44971 1 a44971 1 in hex, like '"55a2b900"'. d44973 1 a44973 1 When the 'repl' context is used for the 'evaluate' request, GDB d44977 1 a44977 1 For example, evaluating the 'continue' command could do this, as could d44980 1 a44980 1 'repl' evaluation can also cause GDB to appear to stop responding to d44983 2 a44984 2 Evaluations like this can be interrupted using the DAP 'cancel' request. (In fact, 'cancel' should work for any request, but it is d44988 1 a44988 1 mode. These can be set on the command line using the '-iex' option d44991 1 a44991 1 'set debug dap-log-file [FILENAME]' d44995 2 a44996 2 'set debug dap-log-level LEVEL' Set the DAP logging level. The default is '1', which logs the DAP d44998 1 a44998 1 useful, and unexpected exceptions. Level '2' can be used to log d45009 1 a45009 1 This chapter documents GDB's "just-in-time" (JIT) compilation interface. d45095 1 a45095 1 * Generate an object file in memory with symbols and other desired d45099 1 a45099 1 * Create a code entry for the file, which gives the start and size of d45102 1 a45102 1 * Add it to the linked list in the JIT descriptor. d45104 1 a45104 1 * Point the relevant_entry field of the descriptor at the entry. d45106 2 a45107 2 * Set 'action_flag' to 'JIT_REGISTER' and call '__jit_debug_register_code'. d45110 1 a45110 1 'relevant_entry' pointer so it doesn't have to walk the list looking for d45123 1 a45123 1 * Remove the code entry corresponding to the code from the linked d45126 1 a45126 1 * Point the 'relevant_entry' field of the descriptor at the code d45129 2 a45130 2 * Set 'action_flag' to 'JIT_UNREGISTER' and call '__jit_debug_register_code'. d45149 2 a45150 2 'gdb/jit-reader.in', which is also installed as a header at 'INCLUDEDIR/gdb/jit-reader.h' for easy inclusion. d45154 2 a45155 2 at runtime). Two GDB commands, 'jit-reader-load' and 'jit-reader-unload' are provided, to be used to load and unload the d45170 2 a45171 2 Readers can be loaded and unloaded using the 'jit-reader-load' and 'jit-reader-unload' commands. d45173 1 a45173 1 'jit-reader-load READER' d45177 2 a45178 2 directory, usually 'LIBDIR/gdb/' on a UNIX system (here LIBDIR is the system library directory, often '/usr/local/lib'). d45183 2 a45184 2 current one using 'jit-reader-unload' and then invoking 'jit-reader-load'. d45186 1 a45186 1 'jit-reader-unload' d45196 1 a45196 1 certain ABI. This ABI is described in 'jit-reader.h'. d45198 1 a45198 1 'jit-reader.h' defines the structures, macros and functions required d45200 1 a45200 1 'INCLUDEDIR/gdb' where INCLUDEDIR is the system include directory. d45204 1 a45204 1 'GDB_DECLARE_GPL_COMPATIBLE_READER' in a source file. d45206 1 a45206 1 The entry point for readers is the symbol 'gdb_init_reader', which is d45211 1 a45211 1 'struct gdb_reader_funcs' contains a set of pointers to callback d45213 2 a45214 2 generated by the JIT compiler ('read'), to unwind stack frames ('unwind') and to create canonical frame IDs ('get_frame_id'). It also d45216 1 a45216 1 ('destroy'). The struct looks like this d45233 3 a45235 3 their job. For 'read', these callbacks are passed in a 'struct gdb_symbol_callbacks' and for 'unwind' and 'get_frame_id', in a 'struct gdb_unwind_callbacks'. 'struct gdb_symbol_callbacks' has callbacks to d45237 1 a45237 1 'struct gdb_unwind_callbacks' has callbacks to read registers off the d45239 1 a45239 1 previous frame. Both have a callback ('target_read') to read bytes off d45264 2 a45265 2 reduce the number of operations performed by debugger. The "In-Process Agent", a shared library, is running within the same process with d45280 1 a45280 1 'set agent on' d45289 1 a45289 1 'set agent off' d45293 1 a45293 1 'show agent' d45329 1 a45329 1 complex data types called "objects". d45366 1 a45366 1 addr 8 if BASEREG is '-1', ADDR is the d45418 1 a45418 1 'FastTrace:TRACEPOINT_OBJECT GDB_JUMP_PAD_HEAD' d45421 1 a45421 1 is the head of "jumppad", which is used to jump to data collection d45425 1 a45425 1 'OK TARGET_ADDRESS GDB_JUMP_PAD_HEAD FJUMP_SIZE FJUMP' d45432 1 a45432 1 'close' d45436 1 a45436 1 'qTfSTM' d45438 1 a45438 1 'qTsSTM' d45440 1 a45440 1 'qTSTMat' d45442 1 a45442 1 'probe_marker_at:ADDRESS' d45446 1 a45446 1 'unprobe_marker_at:ADDRESS' d45479 1 a45479 1 * If the debugger gets a fatal signal, for any input whatever, that d45482 1 a45482 1 * If GDB produces an error message for valid input, that is a bug. d45486 1 a45486 1 * If GDB does not produce an error message for invalid input, that is d45491 1 a45491 1 * If you are an experienced user of debugging tools, your suggestions d45505 1 a45505 1 individuals in the file 'etc/SERVICE' in the GNU Emacs distribution. d45536 2 a45537 2 * The version of GDB. GDB announces it if you start with no arguments; you can also print it at any time using 'show version'. d45542 1 a45542 1 * The type of machine you are using, and the operating system name d45545 3 a45547 3 * The details of the GDB build-time configuration. GDB shows these details if you invoke it with the '--configuration' command-line option, or if you type 'show configuration' at GDB's prompt. d45549 1 a45549 1 * What compiler (and its version) was used to compile GDB--e.g. d45552 1 a45552 1 * What compiler (and its version) was used to compile the program you d45554 1 a45554 1 Compiler". For GCC, you can say 'gcc --version' to get this d45558 2 a45559 2 * The command arguments you gave the compiler to compile your example and observe the bug. For example, did you use '-O'? To guarantee d45566 1 a45566 1 * A complete input script, and all necessary source files, that will d45569 1 a45569 1 * A description of what behavior you observe that you believe is d45588 3 a45590 3 program such as 'script', which is available on many Unix systems. Just run your GDB session inside 'script' and then include the 'typescript' file with your bug report. d45595 1 a45595 1 * If you wish to suggest changes to the GDB source, send us context d45605 1 a45605 1 * A description of the envelope of the bug. d45625 1 a45625 1 * A patch for the bug. d45643 1 a45643 1 * A guess about what the bug is or what it depends on. d45676 1 a45676 1 The text 'C-k' is read as 'Control-K' and describes the character d45679 1 a45679 1 The text 'M-k' is read as 'Meta-K' and describes the character d45690 1 a45690 1 _first_, and then typing . Either process is known as "metafying" d45693 2 a45694 2 The text 'M-C-k' is read as 'Meta-Control-k' and describes the character produced by "metafying" 'C-k'. d45741 2 a45742 2 'C-b' to move the cursor to the left, and then correct your mistake. Afterwards, you can move the cursor to the right with 'C-f'. d45751 1 a45751 1 'C-b' d45753 1 a45753 1 'C-f' d45757 1 a45757 1 'C-d' d45761 1 a45761 1 'C-_' or 'C-x C-u' d45767 1 a45767 1 the character underneath the cursor, like 'C-d', rather than the d45778 1 a45778 1 commands have been added in addition to 'C-b', 'C-f', 'C-d', and . d45781 1 a45781 1 'C-a' d45783 1 a45783 1 'C-e' d45785 1 a45785 1 'M-f' d45788 1 a45788 1 'M-b' d45790 1 a45790 1 'C-l' d45793 1 a45793 1 Notice how 'C-f' moves forward a character, while 'M-f' moves forward d45803 2 a45804 2 "Killing" text means to delete the text from the line, but to save it away for later use, usually by "yanking" (re-inserting) it back into the d45811 1 a45811 1 When you use a kill command, the text is saved in a "kill-ring". Any d45819 1 a45819 1 'C-k' d45823 1 a45823 1 'M-d' d45826 1 a45826 1 as those used by 'M-f'. d45828 1 a45828 1 'M-' d45831 1 a45831 1 same as those used by 'M-b'. d45833 1 a45833 1 'C-w' d45835 1 a45835 1 than 'M-' because the word boundaries differ. d45837 1 a45837 1 Here is how to "yank" the text back into the line. Yanking means to d45840 1 a45840 1 'C-y' d45844 1 a45844 1 'M-y' d45846 1 a45846 1 if the prior command is 'C-y' or 'M-y'. d45859 1 a45859 1 start of the line, you might type 'M-- C-k'. d45863 1 a45863 1 sign ('-'), then the sign of the argument will be negative. Once you d45866 1 a45866 1 'C-d' command an argument of 10, you could type 'M-1 0 C-d', which will d45877 1 a45877 1 "incremental" and "non-incremental". d45884 1 a45884 1 history for a particular string, type 'C-r'. Typing 'C-s' searches d45886 1 a45886 1 'isearch-terminators' variable are used to terminate an incremental d45888 1 a45888 1 'C-J' characters will terminate an incremental search. 'C-g' will abort d45893 2 a45894 2 To find other matching entries in the history list, type 'C-r' or 'C-s' as appropriate. This will search backward or forward in the d45902 1 a45902 1 Readline remembers the last incremental search string. If two 'C-r's d45919 1 a45919 1 putting commands in an "inputrc" file, conventionally in his home d45921 3 a45923 3 environment variable 'INPUTRC'. If that variable is unset, the default is '~/.inputrc'. If that file does not exist or cannot be read, the ultimate default is '/etc/inputrc'. d45928 1 a45928 1 In addition, the 'C-x C-r' command re-reads this init file, thus d45946 2 a45947 2 Blank lines are ignored. Lines beginning with a '#' are comments. Lines beginning with a '$' indicate conditional constructs (*note d45953 1 a45953 1 values of variables in Readline using the 'set' command within the d45959 1 a45959 1 binding to use 'vi' line editing commands: d45973 1 a45973 1 'bell-style' d45975 3 a45977 3 bell. If set to 'none', Readline never rings the bell. If set to 'visible', Readline uses a visible bell if one is available. If set to 'audible' (the default), Readline d45980 2 a45981 2 'bind-tty-special-chars' If set to 'on' (the default), Readline attempts to bind the d45985 2 a45986 2 'blink-matching-paren' If set to 'on', Readline attempts to briefly move the cursor d45988 1 a45988 1 inserted. The default is 'off'. d45990 2 a45991 2 'colored-completion-prefix' If set to 'on', when listing completions, Readline displays d45994 2 a45995 2 value of the 'LS_COLORS' environment variable. The default is 'off'. d45997 2 a45998 2 'colored-stats' If set to 'on', Readline displays possible completions using d46000 2 a46001 2 definitions are taken from the value of the 'LS_COLORS' environment variable. The default is 'off'. d46003 1 a46003 1 'comment-begin' d46005 2 a46006 2 'insert-comment' command is executed. The default value is '"#"'. d46008 1 a46008 1 'completion-display-width' d46015 2 a46016 2 'completion-ignore-case' If set to 'on', Readline performs filename matching and d46018 1 a46018 1 is 'off'. d46020 3 a46022 3 'completion-map-case' If set to 'on', and COMPLETION-IGNORE-CASE is enabled, Readline treats hyphens ('-') and underscores ('_') as d46024 1 a46024 1 and completion. The default value is 'off'. d46026 1 a46026 1 'completion-prefix-display-length' d46033 1 a46033 1 'completion-query-items' d46041 1 a46041 1 never ask. The default limit is '100'. d46043 2 a46044 2 'convert-meta' If set to 'on', Readline will convert characters with the d46047 2 a46048 2 to a meta-prefixed key sequence. The default value is 'on', but will be set to 'off' if the locale is one that contains d46051 2 a46052 2 'disable-completion' If set to 'On', Readline will inhibit word completion. d46054 1 a46054 1 they had been mapped to 'self-insert'. The default is 'off'. d46056 2 a46057 2 'echo-control-characters' When set to 'on', on operating systems that indicate they d46059 1 a46059 1 signal generated from the keyboard. The default is 'on'. d46061 2 a46062 2 'editing-mode' The 'editing-mode' variable controls which default set of key d46065 1 a46065 1 This variable can be set to either 'emacs' or 'vi'. d46067 1 a46067 1 'emacs-mode-string' d46073 1 a46073 1 Use the '\1' and '\2' escapes to begin and end sequences of d46075 1 a46075 1 control sequence into the mode string. The default is '@@'. d46077 2 a46078 2 'enable-bracketed-paste' When set to 'On', Readline will configure the terminal in a d46083 1 a46083 1 editing commands. The default is 'On'. d46085 2 a46086 2 'enable-keypad' When set to 'on', Readline will try to enable the application d46088 1 a46088 1 the arrow keys. The default is 'off'. d46090 2 a46091 2 'enable-meta-key' When set to 'on', Readline will try to enable any meta d46094 1 a46094 1 characters. The default is 'on'. d46096 3 a46098 3 'expand-tilde' If set to 'on', tilde expansion is performed when Readline attempts word completion. The default is 'off'. d46100 2 a46101 2 'history-preserve-point' If set to 'on', the history code attempts to place the point d46103 2 a46104 2 history line retrieved with 'previous-history' or 'next-history'. The default is 'off'. d46106 1 a46106 1 'history-size' d46115 3 a46117 3 'horizontal-scroll-mode' This variable can be set to either 'on' or 'off'. Setting it to 'on' means that the text of the lines being edited will d46120 1 a46120 1 a new screen line. This variable is automatically set to 'on' d46122 1 a46122 1 to 'off'. d46124 2 a46125 2 'input-meta' If set to 'on', Readline will enable eight-bit input (it will d46128 1 a46128 1 default value is 'off', but Readline will set it to 'on' if d46130 1 a46130 1 'meta-flag' is a synonym for this variable. d46132 1 a46132 1 'isearch-terminators' d46136 1 a46136 1 given a value, the characters and 'C-J' will terminate d46139 1 a46139 1 'keymap' d46141 7 a46147 7 commands. Built-in 'keymap' names are 'emacs', 'emacs-standard', 'emacs-meta', 'emacs-ctlx', 'vi', 'vi-move', 'vi-command', and 'vi-insert'. 'vi' is equivalent to 'vi-command' ('vi-move' is also a synonym); 'emacs' is equivalent to 'emacs-standard'. Applications may add additional names. The default value is 'emacs'. The value of the 'editing-mode' variable also affects the default keymap. d46149 1 a46149 1 'keyseq-timeout' d46157 1 a46157 1 input source ('rl_instream' by default). The value is d46163 1 a46163 1 value is '500'. d46165 8 a46172 8 'mark-directories' If set to 'on', completed directory names have a slash appended. The default is 'on'. 'mark-modified-lines' This variable, when set to 'on', causes Readline to display an asterisk ('*') at the start of history lines which have been modified. This variable is 'off' by default. d46174 2 a46175 2 'mark-symlinked-directories' If set to 'on', completed names which are symbolic links to d46177 1 a46177 1 'mark-directories'). The default is 'off'. d46179 6 a46184 6 'match-hidden-files' This variable, when set to 'on', causes Readline to match files whose names begin with a '.' (hidden files) when performing filename completion. If set to 'off', the leading '.' must be supplied by the user in the filename to be completed. This variable is 'on' by default. d46186 2 a46187 2 'menu-complete-display-prefix' If set to 'on', menu completion displays the common prefix of d46189 1 a46189 1 cycling through the list. The default is 'off'. d46191 2 a46192 2 'output-meta' If set to 'on', Readline will display characters with the d46194 2 a46195 2 sequence. The default is 'off', but Readline will set it to 'on' if the locale contains eight-bit characters. d46197 2 a46198 2 'page-completions' If set to 'on', Readline uses an internal 'more'-like pager to d46200 1 a46200 1 variable is 'on' by default. d46202 2 a46203 2 'print-completions-horizontally' If set to 'on', Readline will display completions with matches d46205 1 a46205 1 the screen. The default is 'off'. d46207 3 a46209 3 'revert-all-at-newline' If set to 'on', Readline will undo all changes to history lines before returning when 'accept-line' is executed. By d46211 1 a46211 1 undo lists across calls to 'readline'. The default is 'off'. d46213 1 a46213 1 'show-all-if-ambiguous' d46215 1 a46215 1 If set to 'on', words which have more than one possible d46217 1 a46217 1 of ringing the bell. The default value is 'off'. d46219 1 a46219 1 'show-all-if-unmodified' d46222 1 a46222 1 'on', words which have more than one possible completion d46226 1 a46226 1 default value is 'off'. d46228 2 a46229 2 'show-mode-in-prompt' If set to 'on', add a string to the beginning of the prompt d46232 1 a46232 1 EMACS-MODE-STRING). The default value is 'off'. d46234 2 a46235 2 'skip-completed-text' If set to 'on', this alters the default completion behavior d46242 2 a46243 2 completion when the cursor is after the 'e' in 'Makefile' will result in 'Makefile' rather than 'Makefilefile', assuming d46245 1 a46245 1 'off'. d46247 1 a46247 1 'vi-cmd-mode-string' d46253 1 a46253 1 is available. Use the '\1' and '\2' escapes to begin and end d46256 1 a46256 1 default is '(cmd)'. d46258 1 a46258 1 'vi-ins-mode-string' d46264 1 a46264 1 is available. Use the '\1' and '\2' escapes to begin and end d46267 1 a46267 1 default is '(ins)'. d46269 2 a46270 2 'visible-stats' If set to 'on', a character denoting a file's type is appended d46272 1 a46272 1 default is 'off'. d46298 3 a46300 3 In the example above, 'C-u' is bound to the function 'universal-argument', 'M-DEL' is bound to the function 'backward-kill-word', and 'C-o' is bound to run the macro d46302 1 a46302 1 '> output' into the line). d46319 5 a46323 5 In the above example, 'C-u' is again bound to the function 'universal-argument' (just as it was in the first example), ''C-x' 'C-r'' is bound to the function 're-read-init-file', and ' <[> <1> <1> <~>' is bound to insert the text 'Function Key 1'. d46328 1 a46328 1 '\C-' d46330 1 a46330 1 '\M-' d46332 1 a46332 1 '\e' d46334 1 a46334 1 '\\' d46336 1 a46336 1 '\"' d46338 1 a46338 1 '\'' d46344 1 a46344 1 '\a' d46346 1 a46346 1 '\b' d46348 1 a46348 1 '\d' d46350 1 a46350 1 '\f' d46352 1 a46352 1 '\n' d46354 1 a46354 1 '\r' d46356 1 a46356 1 '\t' d46358 1 a46358 1 '\v' d46360 1 a46360 1 '\NNN' d46363 1 a46363 1 '\xHH' d46371 2 a46372 2 character in the macro text, including '"' and '''. For example, the following binding will make ''C-x' \' insert a single '\' into d46387 2 a46388 2 '$if' The '$if' construct allows bindings to be made based on the editing d46394 6 a46399 6 'mode' The 'mode=' form of the '$if' directive is used to test whether Readline is in 'emacs' or 'vi' mode. This may be used in conjunction with the 'set keymap' command, for instance, to set bindings in the 'emacs-standard' and 'emacs-ctlx' keymaps only if Readline is starting out in 'emacs' mode. d46401 2 a46402 2 'term' The 'term=' form may be used to include terminal-specific key d46405 7 a46411 7 '=' is tested against both the full name of the terminal and the portion of the terminal name before the first '-'. This allows 'sun' to match both 'sun' and 'sun-cmd', for instance. 'version' The 'version' test may be used to perform comparisons against specific Readline versions. The 'version' expands to the d46413 1 a46413 1 includes '=' (and '=='), '!=', '<=', '>=', '<', and '>'. The d46416 3 a46418 3 and an optional minor version (e.g., '7.1'). If the minor version is omitted, it is assumed to be '0'. The operator may be separated from the string 'version' and from the version d46425 1 a46425 1 'application' d46438 1 a46438 1 'variable' d46441 1 a46441 1 operators are '=', '==', and '!='. The variable name must be d46447 1 a46447 1 'mode=emacs' test described above: d46452 2 a46453 2 '$endif' This command, as seen in the previous example, terminates an '$if' d46456 2 a46457 2 '$else' Commands in this branch of the '$if' directive are executed if the d46460 1 a46460 1 '$include' d46463 1 a46463 1 directive reads from '/etc/inputrc': d46596 2 a46597 2 In the following descriptions, "point" refers to the current cursor position, and "mark" refers to a cursor position saved by the 'set-mark' d46599 1 a46599 1 "region". d46607 1 a46607 1 'beginning-of-line (C-a)' d46610 1 a46610 1 'end-of-line (C-e)' d46613 1 a46613 1 'forward-char (C-f)' d46616 1 a46616 1 'backward-char (C-b)' d46619 1 a46619 1 'forward-word (M-f)' d46623 1 a46623 1 'backward-word (M-b)' d46627 1 a46627 1 'previous-screen-line ()' d46634 1 a46634 1 'next-screen-line ()' d46641 1 a46641 1 'clear-display (M-C-l)' d46646 1 a46646 1 'clear-screen (C-l)' d46650 1 a46650 1 'redraw-current-line ()' d46659 1 a46659 1 'accept-line (Newline or Return)' d46662 1 a46662 1 with 'add_history()'. If this line is a modified history line, the d46665 1 a46665 1 'previous-history (C-p)' d46669 1 a46669 1 'next-history (C-n)' d46672 1 a46672 1 'beginning-of-history (M-<)' d46675 1 a46675 1 'end-of-history (M->)' d46679 1 a46679 1 'reverse-search-history (C-r)' d46685 1 a46685 1 'forward-search-history (C-s)' d46691 1 a46691 1 'non-incremental-reverse-search-history (M-p)' d46697 1 a46697 1 'non-incremental-forward-search-history (M-n)' d46703 1 a46703 1 'history-search-forward ()' d46709 1 a46709 1 'history-search-backward ()' d46715 1 a46715 1 'history-substring-search-forward ()' d46721 1 a46721 1 'history-substring-search-backward ()' d46727 1 a46727 1 'yank-nth-arg (M-C-y)' d46733 1 a46733 1 argument N is computed, the argument is extracted as if the '!N' d46736 1 a46736 1 'yank-last-arg (M-. or M-_)' d46739 1 a46739 1 like 'yank-nth-arg'. Successive calls to 'yank-last-arg' move back d46746 1 a46746 1 as if the '!$' history expansion had been specified. d46748 1 a46748 1 'operate-and-get-next (C-o)' d46761 1 a46761 1 'end-of-file (usually C-d)' d46763 1 a46763 1 'stty'. If this character is read when there are no characters on d46767 1 a46767 1 'delete-char (C-d)' d46769 1 a46769 1 same character as the tty EOF character, as 'C-d' commonly is, see d46772 1 a46772 1 'backward-delete-char (Rubout)' d46776 1 a46776 1 'forward-backward-delete-char ()' d46781 1 a46781 1 'quoted-insert (C-q or C-v)' d46783 1 a46783 1 insert key sequences like 'C-q', for example. d46785 1 a46785 1 'tab-insert (M-)' d46788 1 a46788 1 'self-insert (a, b, A, 1, !, ...)' d46791 1 a46791 1 'bracketed-paste-begin ()' d46797 1 a46797 1 was bound to 'self-insert' instead of executing any editing d46805 1 a46805 1 'transpose-chars (C-t)' d46811 1 a46811 1 'transpose-words (M-t)' d46816 1 a46816 1 'upcase-word (M-u)' d46820 1 a46820 1 'downcase-word (M-l)' d46824 1 a46824 1 'capitalize-word (M-c)' d46828 1 a46828 1 'overwrite-mode ()' d46832 2 a46833 2 'emacs' mode; 'vi' mode does overwrite differently. Each call to 'readline()' starts in insert mode. d46835 1 a46835 1 In overwrite mode, characters bound to 'self-insert' replace the d46837 1 a46837 1 Characters bound to 'backward-delete-char' replace the character d46848 1 a46848 1 'kill-line (C-k)' d46853 1 a46853 1 'backward-kill-line (C-x Rubout)' d46858 1 a46858 1 'unix-line-discard (C-u)' d46861 1 a46861 1 'kill-whole-line ()' d46865 1 a46865 1 'kill-word (M-d)' d46868 1 a46868 1 as 'forward-word'. d46870 1 a46870 1 'backward-kill-word (M-)' d46872 1 a46872 1 'backward-word'. d46874 1 a46874 1 'shell-transpose-words (M-C-t)' d46878 2 a46879 2 boundaries are the same as 'shell-forward-word' and 'shell-backward-word'. d46881 1 a46881 1 'unix-word-rubout (C-w)' d46885 1 a46885 1 'unix-filename-rubout ()' d46890 1 a46890 1 'delete-horizontal-space ()' d46894 1 a46894 1 'kill-region ()' d46898 1 a46898 1 'copy-region-as-kill ()' d46902 1 a46902 1 'copy-backward-word ()' d46904 1 a46904 1 are the same as 'backward-word'. By default, this command is d46907 1 a46907 1 'copy-forward-word ()' d46909 1 a46909 1 boundaries are the same as 'forward-word'. By default, this d46912 1 a46912 1 'yank (C-y)' d46915 1 a46915 1 'yank-pop (M-y)' d46917 1 a46917 1 if the prior command is 'yank' or 'yank-pop'. d46925 1 a46925 1 'digit-argument (M-0, M-1, ... M--)' d46927 1 a46927 1 argument. 'M--' starts a negative argument. d46929 1 a46929 1 'universal-argument ()' d46933 1 a46933 1 by digits, executing 'universal-argument' again ends the numeric d46948 1 a46948 1 'complete ()' d46953 1 a46953 1 'possible-completions (M-?)' d46956 2 a46957 2 for display to the value of 'completion-display-width', the value of the environment variable 'COLUMNS', or the screen width, in that d46960 1 a46960 1 'insert-completions (M-*)' d46962 1 a46962 1 been generated by 'possible-completions'. d46964 2 a46965 2 'menu-complete ()' Similar to 'complete', but replaces the word to be completed with a d46967 1 a46967 1 execution of 'menu-complete' steps through the list of possible d46970 1 a46970 1 'bell-style') and the original text is restored. An argument of N d46976 3 a46978 3 'menu-complete-backward ()' Identical to 'menu-complete', but moves backward through the list of possible completions, as if 'menu-complete' had been given a d46981 1 a46981 1 'delete-char-or-list ()' d46983 2 a46984 2 end of the line (like 'delete-char'). If at the end of the line, behaves identically to 'possible-completions'. This command is d46993 1 a46993 1 'start-kbd-macro (C-x ()' d46996 1 a46996 1 'end-kbd-macro (C-x ))' d47000 1 a47000 1 'call-last-kbd-macro (C-x e)' d47004 1 a47004 1 'print-last-kbd-macro ()' d47014 1 a47014 1 're-read-init-file (C-x C-r)' d47018 1 a47018 1 'abort (C-g)' d47020 1 a47020 1 (subject to the setting of 'bell-style'). d47022 1 a47022 1 'do-lowercase-version (M-A, M-B, M-X, ...)' d47027 1 a47027 1 'prefix-meta ()' d47029 1 a47029 1 meta key. Typing ' f' is equivalent to typing 'M-f'. d47031 1 a47031 1 'undo (C-_ or C-x C-u)' d47034 1 a47034 1 'revert-line (M-r)' d47036 1 a47036 1 'undo' command enough times to get back to the beginning. d47038 1 a47038 1 'tilde-expand (M-~)' d47041 1 a47041 1 'set-mark (C-@@)' d47045 1 a47045 1 'exchange-point-and-mark (C-x C-x)' d47050 1 a47050 1 'character-search (C-])' d47055 1 a47055 1 'character-search-backward (M-C-])' d47060 1 a47060 1 'skip-csi-sequence ()' d47069 2 a47070 2 'insert-comment (M-#)' Without a numeric argument, the value of the 'comment-begin' d47074 2 a47075 2 'comment-begin', the value is inserted, otherwise the characters in 'comment-begin' are deleted from the beginning of the line. In d47078 1 a47078 1 'dump-functions ()' d47084 1 a47084 1 'dump-variables ()' d47090 1 a47090 1 'dump-macros ()' d47096 2 a47097 2 'emacs-editing-mode (C-e)' When in 'vi' command mode, this causes a switch to 'emacs' editing d47100 2 a47101 2 'vi-editing-mode (M-C-j)' When in 'emacs' editing mode, this causes a switch to 'vi' editing d47110 1 a47110 1 While the Readline library does not have a full set of 'vi' editing d47112 1 a47112 1 The Readline 'vi' mode behaves as specified in the POSIX standard. d47114 4 a47117 4 In order to switch interactively between 'emacs' and 'vi' editing modes, use the command 'M-C-j' (bound to emacs-editing-mode when in 'vi' mode and to vi-editing-mode in 'emacs' mode). The Readline default is 'emacs' mode. d47119 2 a47120 2 When you enter a line in 'vi' mode, you are already placed in 'insertion' mode, as if you had typed an 'i'. Pressing switches d47122 2 a47123 2 the standard 'vi' movement keys, move to previous history lines with 'k' and subsequent lines with 'j', and so forth. d47147 1 a47147 1 to the history expansion provided by 'csh'. This section describes the d47159 2 a47160 2 called the "event", and the portions of that line that are acted upon are called "words". Various "modifiers" are available to manipulate the d47164 1 a47164 1 history expansion character, which is '!' by default. d47190 1 a47190 1 '!' d47192 1 a47192 1 the end of the line, or '='. d47194 1 a47194 1 '!N' d47197 1 a47197 1 '!-N' d47200 2 a47201 2 '!!' Refer to the previous command. This is a synonym for '!-1'. d47203 1 a47203 1 '!STRING' d47207 1 a47207 1 '!?STRING[?]' d47209 1 a47209 1 the history list containing STRING. The trailing '?' may be d47214 1 a47214 1 '^STRING1^STRING2^' d47216 1 a47216 1 with STRING2. Equivalent to '!!:s^STRING1^STRING2^'. d47218 1 a47218 1 '!#' d47227 1 a47227 1 Word designators are used to select desired words from the event. A ':' d47229 1 a47229 1 omitted if the word designator begins with a '^', '$', '*', '-', or '%'. d47236 1 a47236 1 '!!' d47240 1 a47240 1 '!!:$' d47242 1 a47242 1 shortened to '!$'. d47244 1 a47244 1 '!fi:2' d47246 1 a47246 1 with the letters 'fi'. d47250 2 a47251 2 '0 (zero)' The '0'th word. For many applications, this is the command word. d47253 1 a47253 1 'N' d47256 1 a47256 1 '^' d47259 1 a47259 1 '$' d47262 2 a47263 2 '%' The first word matched by the most recent '?STRING?' search, if the d47266 2 a47267 2 'X-Y' A range of words; '-Y' abbreviates '0-Y'. d47269 3 a47271 3 '*' All of the words, except the '0'th. This is a synonym for '1-$'. It is not an error to use '*' if there is just one word in the d47274 2 a47275 2 'X*' Abbreviates 'X-$' d47277 2 a47278 2 'X-' Abbreviates 'X-$' like 'X*', but omits the last word. If 'x' is d47291 1 a47291 1 more of the following modifiers, each preceded by a ':'. These modify, d47294 1 a47294 1 'h' d47297 1 a47297 1 't' d47300 2 a47301 2 'r' Remove a trailing suffix of the form '.SUFFIX', leaving the d47304 1 a47304 1 'e' d47307 1 a47307 1 'p' d47310 1 a47310 1 's/OLD/NEW/' d47312 1 a47312 1 Any character may be used as the delimiter in place of '/'. The d47314 2 a47315 2 '&' appears in NEW, it is replaced by OLD. A single backslash will quote the '&'. If OLD is null, it is set to the last OLD d47317 1 a47317 1 the last STRING in a !?STRING'[?]' search. If NEW is is null, each d47321 1 a47321 1 '&' d47324 2 a47325 2 'g' 'a' d47327 1 a47327 1 conjunction with 's', as in 'gs/OLD/NEW/', or with '&'. d47329 2 a47330 2 'G' Apply the following 's' or '&' modifier once to each word in the d47341 1 a47341 1 'Fred Fish' d47347 1 a47347 1 'Michael Snyder' d47363 1 a47363 1 for printing with PostScript or Ghostscript, in the 'gdb' subdirectory d47366 1 a47366 1 immediately with 'refcard.ps'. d47373 1 a47373 1 The GDB reference card is designed to print in "landscape" mode on US d47383 1 a47383 1 and TeX (or 'texi2roff') to typeset the printed version. d47386 3 a47388 3 this manual in the 'gdb' subdirectory. The main Info file is 'gdb-15.1/gdb/gdb.info', and it refers to subordinate files matching 'gdb.info*' in the same directory. If necessary, you can print out d47390 1 a47390 1 using the 'info' subsystem in GNU Emacs or the standalone 'info' d47394 1 a47394 1 Info formatting programs, such as 'texinfo-format-buffer' or 'makeinfo'. d47396 2 a47397 2 If you have 'makeinfo' installed, and are in the top level GDB source directory ('gdb-15.1', in the case of version 15.1), you can make the d47404 1 a47404 1 a program to print its DVI output files, and 'texinfo.tex', the Texinfo d47411 3 a47413 3 use depends on your system; 'lpr -d' is common; another (for PostScript devices) is 'dvips'. The DVI print command may require a file name without any extension or a '.dvi' extension. d47415 1 a47415 1 TeX also requires a macro definitions file called 'texinfo.tex'. d47418 2 a47419 2 'texinfo.tex' is distributed with GDB and is located in the 'gdb-VERSION-NUMBER/texinfo' directory. d47422 2 a47423 2 and print this manual. First switch to the 'gdb' subdirectory of the main source directory (for example, to 'gdb-15.1/gdb') and type: d47427 1 a47427 1 Then give 'gdb.dvi' to your DVI printing program. d47431 1 a47431 1 (1) In 'gdb-15.1/gdb/refcard.ps' of the version 15.1 release. d47442 1 a47442 1 * Running Configure:: Invoking the GDB 'configure' script d47466 1 a47466 1 program. Other variants of 'make' will not work. d47470 1 a47470 1 'configure' script searches for each of these libraries in several d47472 1 a47472 1 place, you can use either the '--with-LIB' 'configure' option to d47474 2 a47475 2 '---with-LIBRARY-include' (to specify the location of its header files) and '--with-LIBRARY-lib' (to specify the location of its d47477 1 a47477 1 '--with-gmp', '--with-gmp-include', and '--with-gmp-lib'. *Note d47500 1 a47500 1 'configure' script to specify their installation directories if they are d47502 2 a47503 2 '--with-PACKAGE' to force GDB to be compiled with the named PACKAGE, and '--without-PACKAGE' to disable building with it even if it is available. d47505 1 a47505 1 'configure'. d47510 1 a47510 1 . Use the '--with-python=DIR' d47518 1 a47518 1 '--with-guile=GUILE-VERSION' to specify the Guile version to d47525 3 a47527 3 * Remote protocol memory maps (*note Memory Map Format::) * Target descriptions (*note Target Descriptions::) * Remote shared library lists (*Note Library List Format::, or d47529 3 a47531 3 * MS-Windows shared libraries (*note Shared Libraries::) * Traceframe info (*note Traceframe Info Format::) * Branch trace (*note Branch Trace Format::, *note Branch Trace d47535 1 a47535 1 . Use the '--with-libexpat-prefix' d47540 1 a47540 1 require a functioning 'iconv' implementation. If you are on a GNU d47542 2 a47543 2 systems also provide a working 'iconv'. Use the option '--with-iconv-bin' to specify where to find the 'iconv' program. d47545 1 a47545 1 On systems without 'iconv', you can install the GNU Libiconv d47548 1 a47548 1 provide it. Use the '--with-libiconv-prefix' option to 'configure' d47551 2 a47552 2 Alternatively, GDB's top-level 'configure' and 'Makefile' will arrange to build Libiconv if a directory named 'libiconv' appears d47554 1 a47554 1 and if the operating system does not provide a suitable 'iconv' d47559 1 a47559 1 source code to 'libiconv'. d47566 1 a47566 1 '--with-liblzma-prefix' option to specify its non-standard d47570 2 a47571 2 GDB will use the 'zlib' library, if available, to read compressed debug sections. Some linkers, such as GNU 'gold', are capable of d47573 1 a47573 1 compiled with 'zlib', it will be able to read the debug information d47576 1 a47576 1 The 'zlib' library is likely included with your operating system d47583 1 a47583 1 C.2 Invoking the GDB 'configure' Script d47586 3 a47588 3 GDB comes with a 'configure' script that automates the process of preparing GDB for installation; you can then use 'make' to build the 'gdb' program. d47592 1 a47592 1 version number to 'gdb'. d47594 1 a47594 1 For example, the GDB version 15.1 distribution is in the 'gdb-15.1' d47597 1 a47597 1 'gdb-15.1/configure (and supporting files)' d47600 1 a47600 1 'gdb-15.1/gdb' d47603 1 a47603 1 'gdb-15.1/bfd' d47606 1 a47606 1 'gdb-15.1/include' d47609 2 a47610 2 'gdb-15.1/libiberty' source for the '-liberty' free software library d47612 1 a47612 1 'gdb-15.1/opcodes' d47615 1 a47615 1 'gdb-15.1/readline' d47620 3 a47622 3 The simplest way to configure and build GDB is to run 'configure' from the 'gdb-VERSION-NUMBER' source directory, which in this example is the 'gdb-15.1' directory. d47624 2 a47625 2 First switch to the 'gdb-VERSION-NUMBER' source directory if you are not already in it; then run 'configure'. Pass the identifier for the d47634 2 a47635 2 Running 'configure' and then running 'make' builds the included supporting libraries, then 'gdb' itself. The configured source files, d47638 1 a47638 1 'configure' is a Bourne-shell ('/bin/sh') script; if your system does d47640 1 a47640 1 need to run 'sh' on it explicitly: d47644 2 a47645 2 You should run the 'configure' script from the top directory in the source tree, the 'gdb-VERSION-NUMBER' directory. If you run 'configure' d47648 3 a47650 3 run the first 'configure' from the 'gdb' subdirectory of the 'gdb-VERSION-NUMBER' directory, you will omit the configuration of 'bfd', 'readline', and other sibling directories of the 'gdb' d47652 1 a47652 1 such as 'bfd/bfd.h'. d47654 3 a47656 3 You can install 'GDB' anywhere. The best way to do this is to pass the '--prefix' option to 'configure', and then install it with 'make install'. d47665 2 a47666 2 need a different 'gdb' compiled for each combination of host and target. 'configure' is designed to make this easy by allowing you to generate d47668 9 a47676 9 directory. If your 'make' program handles the 'VPATH' feature (GNU 'make' does), running 'make' in each of these directories builds the 'gdb' program specified there. To build 'gdb' in a separate directory, run 'configure' with the '--srcdir' option to specify where to find the source. (You also need to specify a path to find 'configure' itself from your working directory. If the path to 'configure' would be the same as the argument to '--srcdir', you can leave out the '--srcdir' option; it is assumed.) d47687 1 a47687 1 When 'configure' builds a configuration using a remote source d47690 2 a47691 2 the example, you'd find the Sun 4 library 'libiberty.a' in the directory 'gdb-sun4/libiberty', and GDB itself in 'gdb-sun4/gdb'. d47693 3 a47695 3 Make sure that your path to the 'configure' script has just one instance of 'gdb' in it. If your path to 'configure' looks like '../gdb-15.1/gdb/configure', you are configuring only one subdirectory d47697 1 a47697 1 include files such as 'bfd/bfd.h'. d47701 3 a47703 3 one machine--the "host"--while debugging programs that run on another machine--the "target"). You specify a cross-debugging target by giving the '--target=TARGET' option to 'configure'. d47705 1 a47705 1 When you run 'make' to build a program or library, you must run it in d47707 1 a47707 1 'configure' (or one of its subdirectories). d47709 4 a47712 4 The 'Makefile' that 'configure' generates in each source directory also runs recursively. If you type 'make' in a source directory such as 'gdb-15.1' (or in a separate configured directory configured with '--srcdir=DIRNAME/gdb-15.1'), you will build all the required libraries, d47716 1 a47716 1 directories, you can run 'make' on them in parallel (for example, if d47726 1 a47726 1 The specifications used for hosts and targets in the 'configure' script d47733 3 a47735 3 For example, you can use the alias 'sun4' as a HOST argument, or as the value for TARGET in a '--target=TARGET' option. The equivalent full name is 'sparc-sun-sunos4'. d47737 1 a47737 1 The 'configure' script accompanying GDB does not provide any query d47739 1 a47739 1 'configure' calls the Bourne shell script 'config.sub' to map d47756 2 a47757 2 'config.sub' is also distributed in the GDB source directory ('gdb-15.1', for version 15.1). d47762 1 a47762 1 C.5 'configure' Options d47765 2 a47766 2 Here is a summary of the 'configure' options and arguments that are most often useful for building GDB. 'configure' also has several other d47768 1 a47768 1 for a full explanation of 'configure'. d47776 2 a47777 2 You may introduce options with a single '-' rather than '--' if you prefer; but you may abbreviate option names if you use '--'. d47779 2 a47780 2 '--help' Display a quick summary of how to invoke 'configure'. d47782 1 a47782 1 '--prefix=DIR' d47784 1 a47784 1 'DIR'. d47786 2 a47787 2 '--exec-prefix=DIR' Configure the source to install programs under directory 'DIR'. d47789 1 a47789 1 '--srcdir=DIRNAME' d47793 1 a47793 1 separate directories. 'configure' writes configuration-specific d47795 1 a47795 1 source in the directory DIRNAME. 'configure' creates directories d47799 1 a47799 1 '--target=TARGET' d47805 1 a47805 1 targets. Also see the '--enable-targets' option, below. d47811 2 a47812 2 '--enable-targets=[TARGET]...' '--enable-targets=all' d47814 1 a47814 1 list of targets. The special value 'all' configures GDB for d47817 1 a47817 1 '--with-gdb-datadir=PATH' d47819 2 a47820 2 certain supporting files or scripts. This defaults to the 'gdb' subdirectory of 'datadir' (which can be set using '--datadir'). d47822 1 a47822 1 '--with-relocated-sources=DIR' d47826 2 a47827 2 configured prefix, the one mentioned in the '--prefix' or '--exec-prefix' options to configure. This option is useful if GDB d47830 1 a47830 1 '--enable-64-bit-bfd' d47833 1 a47833 1 '--disable-gdbmi' d47836 1 a47836 1 '--enable-tui' d47840 1 a47840 1 '--with-curses' d47844 2 a47845 2 '--with-debuginfod' Build GDB with 'libdebuginfod', the 'debuginfod' client library. d47847 2 a47848 2 'debuginfod' servers using build IDs associated with any missing files. Enabled by default if 'libdebuginfod' is installed and d47850 1 a47850 1 'debuginfod' see *note Debuginfod::. d47852 1 a47852 1 '--with-libunwind-ia64' d47857 1 a47857 1 '--with-system-readline' d47862 1 a47862 1 '--with-system-zlib' d47866 1 a47866 1 '--with-expat' d47876 1 a47876 1 '--with-libiconv-prefix[=DIR]' d47879 2 a47880 2 'iconv' that is built in to the C library is sufficient. If your host does not have a working 'iconv', you can get the latest d47886 1 a47886 1 '--with-lzma' d47894 1 a47894 1 '--with-python[=PYTHON]' d47905 1 a47905 1 '--with-guile[=GUILE]' d47910 2 a47911 2 can be a version number, which will cause 'configure' to try to use that version of Guile; or the file name of a 'pkg-config' d47915 1 a47915 1 '--without-included-regex' d47920 1 a47920 1 '--with-sysroot=DIR' d47922 4 a47925 4 file names begin with '/lib'' or '/usr/lib''. (The value of DIR can be modified at run time by using the 'set sysroot' command.) If DIR is under the GDB configured prefix (set with '--prefix' or '--exec-prefix options', the default system root will be d47929 1 a47929 1 '--with-system-gdbinit=FILE' d47936 1 a47936 1 '--with-system-gdbinit-dir=DIRECTORY' d47943 1 a47943 1 '--enable-build-warnings' d47949 2 a47950 2 '--enable-werror' Treat compiler warnings as errors. It adds the '-Werror' flag to d47954 1 a47954 1 '--enable-ubsan' d47956 2 a47957 2 default, but passing '--enable-ubsan=yes' or '--enable-ubsan=auto' to 'configure' will enable it. The undefined behavior sanitizer d47975 1 a47975 1 '--with-system-gdbinit=FILE' d47978 1 a47978 1 '--with-system-gdbinit-dir=DIRECTORY' d47982 1 a47982 1 If GDB has been configured with the option '--prefix=$prefix', they d47985 6 a47990 6 * If the default location of this init file/directory contains '$prefix', it will be subject to relocation. Suppose that the configure options are '--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit'; if GDB is moved from '$prefix' to '$install', the system init file is looked for as '$install/etc/gdbinit' instead of '$prefix/etc/gdbinit'. d47992 1 a47992 1 * By contrast, if the default location does not contain the prefix, d47994 2 a47995 2 '--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit', then GDB will always look for '/usr/share/gdb/gdbinit', wherever d47999 2 a48000 2 the '--with-system-gdbinit' option at configure time) is in the data-directory (as specified by '--with-gdb-datadir' at configure time) d48002 1 a48002 1 init file in the directory specified by the '--data-directory' d48005 1 a48005 1 GDB has started with the 'set data-directory' command, the file will not d48009 1 a48009 1 '--with-system-gdbinit-dir'. d48013 1 a48013 1 interpreted as regular GDB commands, the files needs to have a '.gdb' d48026 2 a48027 2 The 'system-gdbinit' directory, located inside the data-directory (as specified by '--with-gdb-datadir' at configure time) contains a number d48030 1 a48030 1 with '--with-system-gdbinit'. Otherwise, any user should be able to d48035 1 a48035 1 * 'elinos.py' This script is useful when debugging a program on an d48039 1 a48039 1 'solib-absolute-prefix' and 'solib-search-path' variables d48042 2 a48043 2 * 'wrs-linux.py' This script is useful when debugging a program on a target running Wind River Linux. It expects the 'ENV_PREFIX' to be d48057 2 a48058 2 'maint agent [-at LINESPEC,] EXPRESSION' 'maint agent-eval [-at LINESPEC,] EXPRESSION' d48061 1 a48061 1 (*note Agent Expressions::). The 'agent' version produces an d48063 1 a48063 1 while 'maint agent-eval' produces an expression that evaluates d48065 2 a48066 2 'globa + globb' will include bytecodes to record four bytes of memory at each of the addresses of 'globa' and 'globb', while d48068 1 a48068 1 expression will do the addition and return the sum. If '-at' is d48073 1 a48073 1 'maint agent-printf FORMAT,EXPR,...' d48079 2 a48080 2 'maint info breakpoints' Using the same format as 'info breakpoints', display both the d48086 1 a48086 1 'breakpoint' d48089 1 a48089 1 'watchpoint' d48092 1 a48092 1 'longjmp' d48094 1 a48094 1 'longjmp' calls. d48096 2 a48097 2 'longjmp resume' Internal breakpoint at the target of a 'longjmp'. d48099 2 a48100 2 'until' Temporary internal breakpoint used by the GDB 'until' command. d48102 2 a48103 2 'finish' Temporary internal breakpoint used by the GDB 'finish' d48106 1 a48106 1 'shlib events' d48109 1 a48109 1 'maint info btrace' d48112 1 a48112 1 'maint btrace packet-history' d48114 1 a48114 1 execution history for the 'record btrace' command. Both the d48118 1 a48118 1 'bts' d48126 2 a48127 2 Lowest 'PC' Highest 'PC' d48129 1 a48129 1 'pt' d48141 3 a48143 3 'maint btrace clear-packet-history' Discards the cached packet history printed by the 'maint btrace packet-history' command. The history will be computed again when d48146 1 a48146 1 'maint btrace clear' d48154 2 a48155 2 'maint set btrace pt skip-pad' 'maint show btrace pt skip-pad' d48159 1 a48159 1 'maint info jit' d48163 2 a48164 2 'maint info python-disassemblers' This command is defined within the 'gdb.disassembler' Python module d48169 1 a48169 1 'maint info linux-lwps' d48178 1 a48178 1 listed last against the 'GLOBAL' architecture. d48184 1 a48184 1 are registered, initially the 'i386' disassembler matches the d48186 1 a48186 1 'GLOBAL' disassembler matches. d48202 3 a48204 3 'set displaced-stepping' 'show displaced-stepping' Control whether or not GDB will do "displaced stepping" if the d48211 1 a48211 1 'set displaced-stepping on' d48215 1 a48215 1 'set displaced-stepping off' d48219 1 a48219 1 'set displaced-stepping auto' d48224 1 a48224 1 'maint check-psymtabs' d48229 1 a48229 1 'maint check-symtabs' d48232 1 a48232 1 'maint expand-symtabs [REGEXP]' d48236 2 a48237 2 'maint set catch-demangler-crashes [on|off]' 'maint show catch-demangler-crashes' d48244 1 a48244 1 'maint cplus first_component NAME' d48247 1 a48247 1 'maint cplus namespace' d48250 2 a48251 2 'maint deprecate COMMAND [REPLACEMENT]' 'maint undeprecate COMMAND' d48258 1 a48258 1 'maint dump-me' d48261 1 a48261 1 with the 'SIGQUIT' signal. d48263 3 a48265 3 'maint internal-error [MESSAGE-TEXT]' 'maint internal-warning [MESSAGE-TEXT]' 'maint demangler-warning [MESSAGE-TEXT]' d48267 2 a48268 2 Cause GDB to call the internal function 'internal_error', 'internal_warning' or 'demangler_warning' and hence behave as d48271 2 a48272 2 opportunity to either quit GDB or (for 'internal_error' and 'internal_warning') create a core file of the current GDB session. d48277 1 a48277 1 Here's an example of using 'internal-error': d48287 3 a48289 3 'maint set debuginfod download-sections' 'maint set debuginfod download-sections [on|off]' 'maint show debuginfod download-sections' d48291 1 a48291 1 sections from 'debuginfod'. If disabled, only whole debug info d48295 6 a48300 6 'maint set internal-error ACTION [ask|yes|no]' 'maint show internal-error ACTION' 'maint set internal-warning ACTION [ask|yes|no]' 'maint show internal-warning ACTION' 'maint set demangler-warning ACTION [ask|yes|no]' 'maint show demangler-warning ACTION' d48307 1 a48307 1 'quit' d48311 1 a48311 1 'corefile' d48314 2 a48315 2 do. Note that there is no 'corefile' option for 'demangler-warning': demangler warnings always create a core d48318 4 a48321 4 'maint set internal-error backtrace [on|off]' 'maint show internal-error backtrace' 'maint set internal-warning backtrace [on|off]' 'maint show internal-warning backtrace' d48324 2 a48325 2 stream. This is 'on' by default for 'internal-error' and 'off' by default for 'internal-warning'. d48327 1 a48327 1 'maint packet TEXT' d48330 2 a48331 2 response packet. GDB supplies the initial '$' character, the terminating '#' character, and the checksum. d48334 1 a48334 1 hex, e.g. '\x00', '\x01', etc. d48336 1 a48336 1 'maint print architecture [FILE]' d48340 1 a48340 1 'maint print c-tdesc [-single-feature] [FILE]' d48350 1 a48350 1 When the optional flag '-single-feature' is provided then the d48355 1 a48355 1 'maint print xml-tdesc [FILE]' d48363 1 a48363 1 'maint check xml-descriptions DIR' d48367 1 a48367 1 'maint check libthread-db' d48369 1 a48369 1 library. This exercises all 'libthread_db' functionality used by d48371 1 a48371 1 'proc_service' functions provided by GDB that 'libthread_db' uses. d48375 1 a48375 1 'maint print core-file-backed-mappings' d48378 1 a48378 1 similar to the mappings displayed by the 'info proc mappings' d48381 1 a48381 1 'maint print dummy-frames' d48397 2 a48398 2 'maint print frame-id' 'maint print frame-id LEVEL' d48403 1 a48403 1 'backtrace' output. d48410 5 a48414 5 'maint print registers [FILE]' 'maint print raw-registers [FILE]' 'maint print cooked-registers [FILE]' 'maint print register-groups [FILE]' 'maint print remote-registers [FILE]' d48417 2 a48418 2 The command 'maint print raw-registers' includes the contents of the raw register cache; the command 'maint print cooked-registers' d48421 3 a48423 3 command 'maint print register-groups' includes the groups that each register is a member of; and the command 'maint print remote-registers' includes the remote target's register numbers and d48429 1 a48429 1 'maint print reggroups [FILE]' d48445 2 a48446 2 'maint flush register-cache' 'flushregs' d48449 2 a48450 2 to register fetching, or frame unwinding. The command 'flushregs' is deprecated in favor of 'maint flush register-cache'. d48452 1 a48452 1 'maint flush source-cache' d48463 1 a48463 1 'maint print objfiles [REGEXP]' d48469 2 a48470 2 'maint print user-registers' List all currently available "user registers". User registers d48472 2 a48473 2 They include the four "standard" registers '$fp', '$pc', '$sp', and '$ps'. *Note standard registers::. User registers can be used in d48475 2 a48476 2 only the latter are listed by the 'info registers' and 'maint print registers' commands. d48478 2 a48479 2 'maint print section-scripts [REGEXP]' Print a dump of scripts specified in the '.debug_gdb_section' d48485 1 a48485 1 'maint print statistics' d48487 1 a48487 1 data about that object file followed by the byte cache ("bcache") d48498 3 a48500 3 'maint print target-stack' A "target" is an interface between the debugger and a particular kind of file or process. Targets can be stacked in "strata", so d48507 1 a48507 1 pushed on the "target stack", starting from the top layer down to d48510 1 a48510 1 'maint print type EXPR' d48517 2 a48518 2 'maint print record-instruction' 'maint print record-instruction N' d48525 1 a48525 1 'maint selftest [-verbose] [FILTER]' d48529 1 a48529 1 ran. If '-verbose' is passed, the self tests can be more verbose. d48531 2 a48532 2 'maint set selftest verbose' 'maint show selftest verbose' d48535 1 a48535 1 'maint info selftests' d48538 3 a48540 3 'maint set dwarf always-disassemble' 'maint show dwarf always-disassemble' Control the behavior of 'info address' when using DWARF debugging d48543 2 a48544 2 The default is 'off', which means that GDB should try to describe a variable's location in an easily readable format. When 'on', GDB d48559 2 a48560 2 'maint set dwarf max-cache-age' 'maint show dwarf max-cache-age' d48564 1 a48564 1 those produced by the GCC option '-feliminate-dwarf2-dups', the d48573 2 a48574 2 'maint set dwarf synchronous' 'maint show dwarf synchronous' d48590 2 a48591 2 'maint set dwarf unwinders' 'maint show dwarf unwinders' d48613 1 a48613 1 'maint info frame-unwinders' d48617 2 a48618 2 'maint set worker-threads' 'maint show worker-threads' d48624 1 a48624 1 'unlimited', which lets GDB choose a reasonable number. Note that d48628 2 a48629 2 'maint set profile' 'maint show profile' d48632 1 a48632 1 Profiling will be disabled until you use the 'maint set profile' d48637 2 a48638 2 profiling log file (often called 'gmon.out'). If you have a record of important profiling data in a 'gmon.out' file, be sure to move d48641 2 a48642 2 Configuring with '--enable-profiling' arranges for GDB to be compiled with the '-pg' compiler option. d48644 2 a48645 2 'maint set show-debug-regs' 'maint show show-debug-regs' d48647 1 a48647 1 registers. Use 'on' to enable, 'off' to disable. If enabled, the d48652 2 a48653 2 'maint set show-all-tib' 'maint show show-all-tib' d48655 2 a48656 2 starting at thread local base, when using the 'info w32 thread-information-block' command. d48658 2 a48659 2 'maint set target-async' 'maint show target-async' d48666 2 a48667 2 'maint set target-non-stop' 'maint show target-non-stop' d48670 2 a48671 2 even if 'set non-stop' is 'off' (*note Non-Stop Mode::). The default is 'auto', meaning non-stop mode is enabled if supported by d48674 1 a48674 1 'maint set target-non-stop auto' d48678 1 a48678 1 'maint set target-non-stop on' d48682 1 a48682 1 'maint set target-non-stop off' d48686 2 a48687 2 'maint set tui-resize-message' 'maint show tui-resize-message' d48689 2 a48690 2 resized when in TUI mode. The default is 'off', which means that GDB is silent during resizes. When 'on', GDB will display a d48697 2 a48698 2 'maint set tui-left-margin-verbose' 'maint show tui-left-margin-verbose' d48700 2 a48701 2 windows uses '_' and '0' at locations where otherwise there would be a space. The default is 'off', which means spaces are used. d48706 2 a48707 2 'maint set per-command' 'maint show per-command' d48712 2 a48713 2 'maint set per-command space [on|off]' 'maint show per-command space' d48717 1 a48717 1 can also be requested by invoking GDB with the '--statistics' d48720 2 a48721 2 'maint set per-command time [on|off]' 'maint show per-command time' d48732 1 a48732 1 also be requested by invoking GDB with the '--statistics' d48735 2 a48736 2 'maint set per-command symtab [on|off]' 'maint show per-command symtab' d48745 2 a48746 2 'maint set check-libthread-db [on|off]' 'maint show check-libthread-db' d48754 2 a48755 2 'maint set gnu-source-highlight enabled [on|off]' 'maint show gnu-source-highlight enabled' d48758 1 a48758 1 will be 'on' by default if the GNU Source Highlight library is d48760 2 a48761 2 then this will be 'off' by default, and attempting to change this value to 'on' will give an error. d48771 2 a48772 2 'maint set libopcodes-styling enabled [on|off]' 'maint show libopcodes-styling enabled' d48774 1 a48774 1 ('libopcodes') to style disassembler output (*note Output d48778 1 a48778 1 When this option is 'off' the builtin disassembler will not be used d48782 1 a48782 1 Trying to set this option 'on' for an architecture that the builtin d48786 1 a48786 1 This option is 'on' by default for supported architectures. d48792 1 a48792 1 'maint info screen' d48796 2 a48797 2 'maint space VALUE' An alias for 'maint set per-command space'. A non-zero value d48800 2 a48801 2 'maint time VALUE' An alias for 'maint set per-command time'. A non-zero value d48804 1 a48804 1 'maint translate-address [SECTION] ADDR' d48808 2 a48809 2 location to the specified address. This is similar to the 'info address' command (*note Symbols::), except that this command also d48817 3 a48819 3 'maint test-options require-delimiter' 'maint test-options unknown-is-error' 'maint test-options unknown-is-operand' d48821 1 a48821 1 options framework. The 'require-delimiter' variant requires a d48823 3 a48825 3 'unknown-is-error' and 'unknown-is-operand' do not. The 'unknown-is-error' variant throws an error on unknown option, while 'unknown-is-operand' treats unknown options as the start of the d48828 2 a48829 2 internal result of completion in a variable exposed by the 'maint show test-options-completion-result' command. d48831 2 a48832 2 'maint show test-options-completion-result' Shows the result of completing the 'maint test-options' d48836 2 a48837 2 'maint set test-settings KIND' 'maint show test-settings KIND' d48842 3 a48844 3 'maint set backtrace-on-fatal-signal [on|off]' 'maint show backtrace-on-fatal-signal' When this setting is 'on', if GDB itself terminates with a fatal d48852 1 a48852 1 'off' by default, and attempting to turn this feature on will give d48856 1 a48856 1 is 'on' by default. d48858 1 a48858 1 'maint wait-for-index-cache' d48863 3 a48865 3 'maint with SETTING [VALUE] [-- COMMAND]' Like the 'with' command, but works with 'maintenance set' variables. This is used by the testsuite to exercise the 'with' d48868 2 a48869 2 'maint ignore-probes [-V|-VERBOSE] [PROVIDER [NAME [OBJFILE]]]' 'maint ignore-probes -RESET' d48871 1 a48871 1 OBJFILE arguments are as in 'enable probes' and 'disable probes' d48874 1 a48874 1 Here's an example of using 'maint ignore-probes': d48889 1 a48889 1 'set watchdog NSEC' d48894 1 a48894 1 'show watchdog' d48938 1 a48938 1 In the examples below, '->' and '<-' are used to indicate transmitted d48943 2 a48944 2 A PACKET is introduced with the character '$', the actual PACKET-DATA, and the terminating character '#' followed by a two-digit CHECKSUM: d48949 1 a48949 1 characters between the leading '$' and the trailing '#' (an eight bit d48962 2 a48963 2 first response expected is an acknowledgment: either '+' (to indicate the package was received correctly) or '-' (to request retransmission): d48968 1 a48968 1 The '+'/'-' acknowledgments can be disabled once a connection is d48980 1 a48980 1 of '#' and '$' (see 'X' packet for additional exceptions). d48982 1 a48982 1 Fields within the packet should be separated using ',' ';' or ':'. d48986 1 a48986 1 Implementors should note that prior to GDB 5.0, the character ':' d48996 1 a48996 1 The binary data representation uses '7d' (ASCII '}') as an escape d48998 3 a49000 3 followed by the original character XORed with '0x20'. For example, the byte '0x7d' would be transmitted as the two bytes '0x7d 0x5d'. The bytes '0x23' (ASCII '#'), '0x24' (ASCII '$'), and '0x7d' (ASCII '}') d49002 1 a49002 1 '0x2a' (ASCII '*'), so that it is not interpreted as the start of a d49007 1 a49007 1 repeated character, followed by a '*' and a repeat count. The repeat d49009 1 a49009 1 value of N is sent as 'N+29'. For a repeat count greater or equal to 3, d49012 8 a49019 8 win for counts 3 or more.) Thus, for example, '0* ' is a run-length encoding of "0000": the space character after '*' means repeat the leading '0' '32 - 29 = 3' more times. The printable characters '#' and '$' or with a numeric value greater than 126 must not be used. Runs of six repeats ('#') or seven repeats ('$') can be expanded using a repeat count of only five ('"'). For example, '00000000' can be encoded as '0*"00'. d49028 2 a49029 2 spaces to separate its components. For example, a template like 'foo BAR BAZ' describes a packet beginning with the three ASCII bytes 'foo', d49031 1 a49031 1 space character between the 'foo' and the BAR, or between the BAR and d49035 2 a49036 2 example, a template like 'c [ADDR]' describes a packet beginning with the single ASCII character 'c', possibly followed by an ADDR. d49038 4 a49041 4 At a minimum, a stub is required to support the '?' command to tell GDB the reason for halting, 'g' and 'G' commands for register access, and the 'm' and 'M' commands for memory access. Stubs that only control single-threaded targets can implement run control with the 'c' d49043 2 a49044 2 hardware-assisted single-stepping, the 's' (step) command. Stubs that support multi-threading targets should support the 'vCont' command. All d49058 1 a49058 1 An empty response (raw character sequence '$#00') means the COMMAND d49063 1 a49063 1 'E XX' d49069 1 a49069 1 'E.ERRTEXT' d49088 3 a49090 3 For example, a template like 'foo BAR BAZ' describes a packet beginning with the three ASCII bytes 'foo', followed by a BAR, followed directly by a BAZ. GDB does not transmit a space character between the 'foo' and d49096 1 a49096 1 also be a literal '-1' to indicate all threads, or '0' to pick any d49101 1 a49101 1 process and thread ID fields, as 'pPID.TID'. The PID (process) and TID d49104 3 a49106 3 string, literal '-1' to indicate all processes or threads (respectively), or '0' to indicate an arbitrary process or thread. Specifying just a process, as 'pPID', is equivalent to 'pPID.-1'. It is d49108 1 a49108 1 'p-1.TID'. Note that the 'p' prefix is _not_ used for those packets and d49113 2 a49114 2 GDB and the stub report support for the 'multiprocess' feature using 'qSupported'. *Note multiprocess extensions::, for more information. d49121 1 a49121 1 '!' d49123 1 a49123 1 persistent. The 'R' packet is used to restart the program being d49127 1 a49127 1 'OK' d49130 1 a49130 1 '?' d49138 2 a49139 2 'A ARGLEN,ARGNUM,ARG,...' Initialized 'argv[]' array passed into program. ARGLEN specifies d49141 1 a49141 1 'gdbserver' for more details. d49144 1 a49144 1 'OK' d49147 1 a49147 1 'b BAUD' d49162 2 a49163 2 'B ADDR,MODE' Set (MODE is 'S') or clear (MODE is 'C') a breakpoint at ADDR. d49165 1 a49165 1 Don't use this packet. Use the 'Z' and 'z' packets instead (*note d49168 1 a49168 1 'bc' d49174 1 a49174 1 'bs' d49180 1 a49180 1 'c [ADDR]' d49189 2 a49190 2 'C SIG[;ADDR]' Continue with signal SIG (hex signal number). If ';ADDR' is d49198 1 a49198 1 'd' d49204 2 a49205 2 'D' 'D;PID' d49208 1 a49208 1 the 'detach' command. d49216 1 a49216 1 'OK' d49219 2 a49220 2 'F RC,EE,CF;XX' A reply from GDB to an 'F' packet sent by the target. This is part d49224 1 a49224 1 'g' d49228 1 a49228 1 'XX...' d49232 1 a49232 1 the 'g' packet are determined by the target description (*note d49239 1 a49239 1 literal 'x''s in place of the register data digits, to d49259 1 a49259 1 'G XX...' d49264 1 a49264 1 'OK' d49267 3 a49269 3 'H OP THREAD-ID' Set thread for subsequent operations ('m', 'M', 'g', 'G', et.al.). Depending on the operation to be performed, OP should be 'c' for d49271 1 a49271 1 supporting the 'vCont' command is a better option), and 'g' for d49276 1 a49276 1 'OK' d49279 2 a49280 2 'i [ADDR[,NNN]]' Step the remote target by a single clock cycle. If ',NNN' is d49284 1 a49284 1 'I' d49288 1 a49288 1 'k' d49294 1 a49294 1 system. For that reason, the 'k' packet has no reply. d49303 1 a49303 1 to 'k', GDB does not consider the lack of packet acknowledgment to d49306 1 a49306 1 If connected using 'target extended-remote', and the target does d49311 1 a49311 1 'm ADDR,LENGTH' d49323 1 a49323 1 'XX...' d49329 1 a49329 1 Unlike most packets, this packet does not support 'E.ERRTEXT'-style d49332 1 a49332 1 'M ADDR,LENGTH:XX...' d49338 1 a49338 1 'OK' d49342 1 a49342 1 'p N' d49348 1 a49348 1 'XX...' d49351 1 a49351 1 'P N...=R...' d49357 1 a49357 1 'OK' d49360 3 a49362 3 'q NAME PARAMS...' 'Q NAME PARAMS...' General query ('q') and set ('Q'). These packets are described d49365 1 a49365 1 'r' d49368 1 a49368 1 Don't use this packet; use the 'R' packet instead. d49370 1 a49370 1 'R XX' d49375 1 a49375 1 The 'R' packet has no reply. d49377 1 a49377 1 's [ADDR]' d49386 2 a49387 2 'S SIG[;ADDR]' Step with signal. This is analogous to the 'C' packet, but d49396 1 a49396 1 't ADDR:PP,MM' d49401 1 a49401 1 'T THREAD-ID' d49406 1 a49406 1 'OK' d49409 3 a49411 3 'v' Packets starting with 'v' are identified by a multi-letter name, up to the first ';' or '?' (or the end of the packet). d49413 1 a49413 1 'vAttach;PID' d49424 1 a49424 1 'Any stop packet' d49426 1 a49426 1 'OK' d49429 1 a49429 1 'vCont[;ACTION[:THREAD-ID]]...' d49437 1 a49437 1 specified to match all threads in a process by using the 'pPID.-1' d49443 1 a49443 1 'c' d49445 1 a49445 1 'C SIG' d49448 1 a49448 1 's' d49450 1 a49450 1 'S SIG' d49453 1 a49453 1 't' d49455 1 a49455 1 'r START,END' d49463 1 a49463 1 equivalent to the 's' action. In other words, single-step d49472 2 a49473 2 The optional argument ADDR normally associated with the 'c', 'C', 's', and 'S' packets is not supported in 'vCont'. d49475 1 a49475 1 The 't' action is only relevant in non-stop mode (*note Remote d49478 1 a49478 1 When a thread is stopped by means of a 't' action, the d49480 1 a49480 1 stopped with signal '0', regardless of whether the target uses some d49483 1 a49483 1 The server must ignore 'c', 'C', 's', 'S', and 'r' actions for d49485 1 a49485 1 ignore 't' actions for threads that are already stopped. d49489 1 a49489 1 'vStopped' packet (*note Remote Non-Stop::). d49491 1 a49491 1 The stub must support 'vCont' if it reports support for d49496 2 a49497 2 'vCont?' Request a list of actions supported by the 'vCont' packet. d49500 3 a49502 3 'vCont[;ACTION...]' The 'vCont' packet is supported. Each ACTION is a supported command in the 'vCont' packet. d49504 1 a49504 1 'vCtrlC' d49506 1 a49506 1 terminal. This is the equivalent to reacting to the '^C' ('\003', d49513 1 a49513 1 'OK' d49516 1 a49516 1 'vFile:OPERATION:PARAMETER...' d49520 1 a49520 1 'vFlashErase:ADDR,LENGTH' d49526 2 a49527 2 a 'vFlashDone' request after each group; the stub is allowed to delay erase operation until the 'vFlashDone' packet is received. d49530 1 a49530 1 'OK' d49533 1 a49533 1 'vFlashWrite:ADDR:XX...' d49535 1 a49535 1 passed in binary form using the same encoding as for the 'X' packet d49537 1 a49537 1 'vFlashWrite' packets preceding a 'vFlashDone' packet must not d49539 2 a49540 2 'vFlashErase' packets for higher addresses may already have been received; the ordering is guaranteed only between 'vFlashWrite' d49542 1 a49542 1 by a preceding 'vFlashErase' packet nor by some other d49546 1 a49546 1 'OK' d49548 1 a49548 1 'E.memtype' d49551 1 a49551 1 'vFlashDone' d49554 1 a49554 1 'vFlashErase' and 'vFlashWrite' packets until a 'vFlashDone' packet d49556 1 a49556 1 are unpredictable until the 'vFlashDone' request is completed. d49558 1 a49558 1 'vKill;PID' d49561 1 a49561 1 in preference to 'k' when multiprocess protocol extensions are d49565 1 a49565 1 'OK' d49568 9 a49576 9 'vMustReplyEmpty' The correct reply to an unknown 'v' packet is to return the empty string, however, some older versions of 'gdbserver' would incorrectly return 'OK' for unknown 'v' packets. The 'vMustReplyEmpty' is used as a feature test to check how 'gdbserver' handles unknown packets, it is important that this packet be handled in the same way as other unknown 'v' packets. If this packet is handled differently to other unknown 'v' packets d49578 1 a49578 1 specifically around use of 'vFile:setfs:'. d49580 1 a49580 1 'vRun;FILENAME[;ARGUMENT]...' d49590 1 a49590 1 'Any stop packet' d49593 1 a49593 1 'vStopped' d49596 1 a49596 1 'X ADDR,LENGTH:XX...' d49599 1 a49599 1 memory units LENGTH (*note addressable memory unit::); 'XX...' is d49603 1 a49603 1 'OK' d49606 3 a49608 3 'z TYPE,ADDR,KIND' 'Z TYPE,ADDR,KIND' Insert ('Z') or remove ('z') a TYPE breakpoint or watchpoint d49616 2 a49617 2 target shall support either both or neither of a given 'ZTYPE...' and 'zTYPE...' packet pair. To avoid potential problems with d49621 3 a49623 3 'z0,ADDR,KIND' 'Z0,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]' Insert ('Z0') or remove ('z0') a software breakpoint at address d49633 1 a49633 1 architecture-specific value is being used, it should be '0'. KIND d49640 1 a49640 1 See also the 'swbreak' stop reason (*note swbreak stop reason::) d49647 1 a49647 1 'X LEN,EXPR' d49659 1 a49659 1 'X LEN,EXPR' d49669 1 a49669 1 'OK' d49672 3 a49674 3 'z1,ADDR,KIND' 'Z1,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]' Insert ('Z1') or remove ('z1') a hardware breakpoint at address d49679 1 a49679 1 COND_LIST, and CMD_LIST arguments have the same meaning as in 'Z0' d49686 1 a49686 1 'OK' d49689 3 a49691 3 'z2,ADDR,KIND' 'Z2,ADDR,KIND' Insert ('Z2') or remove ('z2') a write watchpoint at ADDR. The d49695 1 a49695 1 'OK' d49698 3 a49700 3 'z3,ADDR,KIND' 'Z3,ADDR,KIND' Insert ('Z3') or remove ('z3') a read watchpoint at ADDR. The d49704 1 a49704 1 'OK' d49707 3 a49709 3 'z4,ADDR,KIND' 'Z4,ADDR,KIND' Insert ('Z4') or remove ('z4') an access watchpoint at ADDR. The d49713 1 a49713 1 'OK' d49722 5 a49726 5 The 'C', 'c', 'S', 's', 'vCont', 'vAttach', 'vRun', 'vStopped', and '?' packets can receive any of the below as a reply. Except for '?' and 'vStopped', that reply is only returned when the target halts. In the below the exact meaning of "signal number" is defined by the header 'include/gdb/signals.h' in the GDB source code. d49728 2 a49729 2 In non-stop mode, the server will simply reply 'OK' to commands such as 'vCont'; any stop will be the subject of a future notification. d49737 1 a49737 1 'S AA' d49739 1 a49739 1 number). This is equivalent to a 'T' response with no N:R pairs. d49741 1 a49741 1 'T AA N1:R1;N2:R2;...' d49743 2 a49744 2 number). This is equivalent to an 'S' response, except that the 'N:R' pairs can carry values of important registers and other d49747 1 a49747 1 Each 'N:R' pair is interpreted as follows: d49749 1 a49749 1 * If N is a hexadecimal number, it is a register number, and the d49754 1 a49754 1 * If N is 'thread', then R is the thread ID of the stopped d49757 1 a49757 1 * If N is 'core', then R is the hexadecimal number of the core d49760 1 a49760 1 * If N is a recognized "stop reason", it describes a more d49762 1 a49762 1 stop reasons are listed below. The AA should be '05', the d49765 1 a49765 1 * Otherwise, GDB should ignore this 'N:R' pair and go on to the d49770 3 a49772 3 'watch' 'rwatch' 'awatch' d49776 2 a49777 2 'syscall_entry' 'syscall_return' d49781 1 a49781 1 'library' d49783 1 a49783 1 GDB should use 'qXfer:libraries:read' to fetch a new list of d49786 1 a49786 1 'replaylog' d49790 1 a49790 1 of R will be either 'begin' or 'end'. *Note Reverse d49793 1 a49793 1 'swbreak' d49807 2 a49808 2 appropriate 'qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate 'qSupported' d49813 1 a49813 1 'hwbreak' d49817 1 a49817 1 The same remarks about 'qSupported' and non-stop mode above d49820 2 a49821 2 'fork' The packet indicates that 'fork' was called, and R is the d49828 2 a49829 2 appropriate 'qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate 'qSupported' d49832 2 a49833 2 'vfork' The packet indicates that 'vfork' was called, and R is the d49840 2 a49841 2 appropriate 'qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate 'qSupported' d49844 1 a49844 1 'vforkdone' d49846 1 a49846 1 has either called 'exec' or terminated, so that the address d49853 2 a49854 2 appropriate 'qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate 'qSupported' d49857 2 a49858 2 'exec' The packet indicates that 'execve' was called, and R is the d49864 2 a49865 2 appropriate 'qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate 'qSupported' d49868 2 a49869 2 'clone' The packet indicates that 'clone' was called, and R is the d49877 1 a49877 1 'create' d49882 1 a49882 1 QThreadEvents:: packet. See also the 'w' (*note thread exit d49885 2 a49886 2 'W AA' 'W AA ; process:PID' d49896 2 a49897 2 'X AA' 'X AA ; process:PID' d49906 1 a49906 1 'w AA ; TID' d49914 1 a49914 1 'N' d49920 2 a49921 2 though the process is still alive, and thus no 'W' stop reply is sent, no thread is actually executing either. The 'N' stop reply d49925 2 a49926 2 'qSupported' feature (*note qSupported::). The remote stub must also supply the appropriate 'qSupported' feature indicating d49929 2 a49930 2 'O XX...' 'XX...' is hex encoding of ASCII data, to be written as the d49933 1 a49933 1 'W', 'T', etc. This reply is not permitted in non-stop mode. d49935 1 a49935 1 'F CALL-ID,PARAMETER...' d49942 1 a49942 1 'PARAMETER...' is a list of parameters as defined for this very d49947 2 a49948 2 appropriate 'F' packet and keeps up waiting for the next reply packet from the target. The latest 'C', 'c', 'S' or 's' action is d49958 2 a49959 2 Packets starting with 'q' are "general query packets"; packets starting with 'Q' are "general set packets". General query and set packets are a d49965 1 a49965 1 may use a 'qSymbol' packet to exchange symbol definitions with the stub. d49968 3 a49970 3 * The name must not contain commas, colons or semicolons. * Most GDB query and set packets have a leading upper case letter. * The names of custom vendor packets should use a company prefix, in d49972 2 a49973 2 the Acme Corporation might begin with 'qacme.foo' (for querying foos) or 'Qacme.bar' (for setting bars). d49976 2 a49977 2 parameters by a ':'; the parameters themselves should be separated by ',' or ';'. Stubs must be careful to match the full packet name, and d49979 2 a49980 2 share a common prefix. New packets should not begin with 'qC', 'qP', or 'qL'(1). d49990 2 a49991 2 'QAgent:1' 'QAgent:0' d49995 1 a49995 1 'QAllow:OP:VAL...' d49998 2 a49999 2 Possible values for OP include 'WriteReg', 'WriteMem', 'InsertBreak', 'InsertTrace', 'InsertFastTrace', and 'Stop'. VAL d50006 1 a50006 1 'qC' d50010 1 a50010 1 'QC THREAD-ID' d50013 1 a50013 1 '(anything else)' d50016 1 a50016 1 'qCRC:ADDR,LENGTH' d50020 1 a50020 1 '0xffffffff' is used to ensure leading zeros affect the CRC. d50030 1 a50030 1 'C CRC32' d50033 1 a50033 1 'QDisableRandomization:VALUE' d50039 1 a50039 1 randomization for processes subsequently started via 'vRun' d50047 1 a50047 1 'OK' d50051 1 a50051 1 it, by supplying an appropriate 'qSupported' response (*note d50055 1 a50055 1 'QStartupWithShell:VALUE' d50058 2 a50059 2 'gdbserver' (*note set startup-with-shell::). This packet is used to inform 'gdbserver' whether it should start the inferior using a d50062 2 a50063 2 If VALUE is '0', 'gdbserver' will not use a shell to start the inferior. If VALUE is '1', 'gdbserver' will use a shell to start d50070 1 a50070 1 'OK' d50074 1 a50074 1 it, by supplying an appropriate 'qSupported' response (*note d50078 1 a50078 1 Use of this packet is controlled by the 'set startup-with-shell' d50081 1 a50081 1 'QEnvironmentHexEncoded:HEX-VALUE' d50084 1 a50084 1 This packet is used to inform 'gdbserver' of an environment d50092 1 a50092 1 VALUE. If the variable has no value (i.e., the value is 'null'), d50099 1 a50099 1 'OK' d50103 1 a50103 1 it, by supplying an appropriate 'qSupported' response (*note d50107 1 a50107 1 This packet is related to the 'set environment' command; *note set d50110 1 a50110 1 'QEnvironmentUnset:HEX-VALUE' d50113 1 a50113 1 used to inform 'gdbserver' of an environment variable that has been d50123 1 a50123 1 'OK' d50127 1 a50127 1 it, by supplying an appropriate 'qSupported' response (*note d50131 1 a50131 1 This packet is related to the 'unset environment' command; *note d50134 1 a50134 1 'QEnvironmentReset' d50139 3 a50141 3 initially present in the environment). It is sent to 'gdbserver' before the 'QEnvironmentHexEncoded' (*note QEnvironmentHexEncoded::) and the 'QEnvironmentUnset' (*note d50148 1 a50148 1 'OK' d50152 1 a50152 1 it, by supplying an appropriate 'qSupported' response (*note d50156 1 a50156 1 'QSetWorkingDir:[DIRECTORY]' d50171 1 a50171 1 'OK' d50174 2 a50175 2 'qfThreadInfo' 'qsThreadInfo' d50180 2 a50181 2 first query of the sequence will be the 'qfThreadInfo' query; subsequent queries in the sequence will be the 'qsThreadInfo' d50184 1 a50184 1 NOTE: This packet replaces the 'qL' query (see below). d50187 1 a50187 1 'm THREAD-ID' d50189 1 a50189 1 'm THREAD-ID,THREAD-ID...' d50191 2 a50192 2 'l' (lower case letter 'L') denotes end of list. d50196 3 a50198 3 reply with a request for more thread ids (using the 'qs' form of the query), until the target responds with 'l' (lower-case ell, for "last"). Refer to *note thread-id syntax::, for the format of the d50201 1 a50201 1 _Note: GDB will send the 'qfThreadInfo' query during the initial d50205 1 a50205 1 ID in the 'qfThreadInfo' reply is suitable for being stopped by d50208 1 a50208 1 'qGetTLSAddr:THREAD-ID,OFFSET,LM' d50228 1 a50228 1 'XX...' d50232 1 a50232 1 'qGetTIBAddr:THREAD-ID' d50238 1 a50238 1 'XX...' d50242 1 a50242 1 'qL STARTFLAG THREADCOUNT NEXTTHREAD' d50250 1 a50250 1 Don't use this packet; use the 'qfThreadInfo' query instead (see d50254 1 a50254 1 'qM COUNT DONE ARGTHREAD THREAD...' d50261 1 a50261 1 'remote.c:parse_threadlist_response()'. d50263 1 a50263 1 'qMemTags:START ADDRESS,LENGTH:TYPE' d50277 1 a50277 1 for memory tagging via 'qSupported'. d50280 1 a50280 1 'MXX...' d50284 1 a50284 1 'qIsAddressTagged:ADDRESS' d50286 1 a50286 1 it's said to be "tagged". The target is responsible for checking d50295 1 a50295 1 ''01'' d50298 1 a50298 1 ''00'' d50301 1 a50301 1 'QMemTags:START ADDRESS,LENGTH:TYPE:TAG BYTES' d50332 1 a50332 1 for memory tagging via 'qSupported'. d50335 1 a50335 1 'OK' d50339 1 a50339 1 'qOffsets' d50344 3 a50346 3 'Text=XXX;Data=YYY[;Bss=ZZZ]' Relocate the 'Text' section by XXX from its original address. Relocate the 'Data' section by YYY from its original address. d50348 1 a50348 1 ELF 'PT_LOAD' program headers), GDB will relocate entire d50351 3 a50353 3 _Note: while a 'Bss' offset may be included in the response, GDB ignores this and instead applies the 'Data' offset to the 'Bss' section._ d50355 1 a50355 1 'TextSeg=XXX[;DataSeg=YYY]' d50358 1 a50358 1 XXX. If 'DataSeg' is specified, relocate the second segment, d50366 1 a50366 1 'qP MODE THREAD-ID' d50370 1 a50370 1 Don't use this packet; use the 'qThreadExtraInfo' query instead d50373 1 a50373 1 Reply: see 'remote.c:remote_unpack_thread_info_response()'. d50375 3 a50377 3 'QNonStop:1' 'QNonStop:0' Enter non-stop ('QNonStop:1') or all-stop ('QNonStop:0') mode. d50381 1 a50381 1 'OK' d50385 7 a50391 7 it, by supplying an appropriate 'qSupported' response (*note qSupported::). Use of this packet is controlled by the 'set non-stop' command; *note Non-Stop Mode::. 'QCatchSyscalls:1 [;SYSNO]...' 'QCatchSyscalls:0' Enable ('QCatchSyscalls:1') or disable ('QCatchSyscalls:0') d50394 1 a50394 1 For 'QCatchSyscalls:1', each listed syscall SYSNO (encoded in hex) d50400 1 a50400 1 'catch syscall' commands. However, it is more efficient to only d50403 2 a50404 2 Multiple 'QCatchSyscalls:1' packets do not combine; any earlier 'QCatchSyscalls:1' list is completely replaced by the new list. d50406 1 a50406 1 If the inferior process execs, the state of 'QCatchSyscalls' is d50413 1 a50413 1 'OK' d50416 1 a50416 1 Use of this packet is controlled by the 'set remote catch-syscalls' d50419 1 a50419 1 it, by supplying an appropriate 'qSupported' response (*note d50422 1 a50422 1 'QPassSignals: SIGNAL [;SIGNAL]...' d50428 2 a50429 2 signals should be reported to GDB. Multiple 'QPassSignals' packets do not combine; any earlier 'QPassSignals' list is completely d50431 1 a50431 1 using 'handle SIGNAL nostop noprint pass'. d50434 1 a50434 1 'OK' d50437 1 a50437 1 Use of this packet is controlled by the 'set remote pass-signals' d50440 1 a50440 1 it, by supplying an appropriate 'qSupported' response (*note d50443 1 a50443 1 'QProgramSignals: SIGNAL [;SIGNAL]...' d50461 2 a50462 2 'QProgramSignals' packets do not combine; any earlier 'QProgramSignals' list is completely replaced by the new list. d50465 1 a50465 1 'OK' d50468 2 a50469 2 Use of this packet is controlled by the 'set remote program-signals' command (*note set remote program-signals: Remote d50471 1 a50471 1 stub must request it, by supplying an appropriate 'qSupported' d50474 2 a50475 2 'QThreadEvents:1' 'QThreadEvents:0' d50477 1 a50477 1 Enable ('QThreadEvents:1') or disable ('QThreadEvents:0') reporting d50485 1 a50485 1 including 'QThreadEvents+' in its 'qSupported' reply. d50493 1 a50493 1 'OK' d50496 1 a50496 1 Use of this packet is controlled by the 'set remote thread-events' d50499 1 a50499 1 'QThreadOptions[;OPTIONS[:THREAD-ID]]...' d50508 1 a50508 1 to apply to all threads of a process by using the 'pPID.-1' form of d50513 1 a50513 1 options, and is the bitwise 'OR' of the following values. All d50516 1 a50516 1 'GDB_THREAD_OPTION_CLONE (0x1)' d50521 1 a50521 1 'GDB_THREAD_OPTION_EXIT (0x2)' d50524 2 a50525 3 For example, GDB enables the 'GDB_THREAD_OPTION_EXIT' and 'GDB_THREAD_OPTION_CLONE' options when single-stepping a thread d50528 2 a50529 2 * If the single-stepped thread exits (e.g., it executes a thread exit system call), enabling 'GDB_THREAD_OPTION_EXIT' prevents d50534 1 a50534 1 * If the single-stepped thread spawns a new clone child (i.e., d50536 1 a50536 1 'GDB_THREAD_OPTION_CLONE' halts the cloned thread before it d50540 1 a50540 1 - If the breakpoint is stepped-over in-line, the spawned d50546 1 a50546 1 - If displaced (out-of-line) stepping is used, the cloned d50553 2 a50554 2 supports it by including 'QThreadOptions=SUPPORTED_OPTIONS' in its 'qSupported' reply. d50557 1 a50557 1 'OK' d50560 1 a50560 1 Use of this packet is controlled by the 'set remote thread-options' d50563 1 a50563 1 'qRcmd,COMMAND' d50567 1 a50567 1 respond with a number of intermediate 'OOUTPUT' console output d50572 1 a50572 1 'OK' d50574 1 a50574 1 'OUTPUT' d50577 1 a50577 1 Unlike most packets, this packet does not support 'E.ERRTEXT'-style d50580 2 a50581 2 (Note that the 'qRcmd' packet's name is separated from the command by a ',', not a ':', contrary to the naming conventions above. d50584 1 a50584 1 'qSearch:memory:ADDRESS;LENGTH;SEARCH-PATTERN' d50590 1 a50590 1 '0' d50592 1 a50592 1 '1,address' d50595 2 a50596 2 'QStartNoAckMode' Request that the remote stub disable the normal '+'/'-' protocol d50600 1 a50600 1 'OK' d50603 1 a50603 1 send or expect further '+'/'-' acknowledgments in the current d50606 1 a50606 1 'qSupported [:GDBFEATURE [;GDBFEATURE]... ]' d50610 1 a50610 1 'qSupported' also consolidates multiple feature probes at startup, d50623 1 a50623 1 'STUBFEATURE [;STUBFEATURE]...' d50629 1 a50629 1 'qSupported' packet, or a STUBFEATURE in the response) are: d50631 1 a50631 1 'NAME=VALUE' d50635 1 a50635 1 'NAME+' d50638 1 a50638 1 'NAME-' d50640 1 a50640 1 'NAME?' d50646 1 a50646 1 Whenever the stub receives a 'qSupported' request, the supplied set d50654 1 a50654 1 'multiprocess' d50658 1 a50658 1 by including 'multiprocess+' in its 'qSupported' reply. *Note d50661 1 a50661 1 'xmlRegisters' d50663 1 a50663 1 description. If the stub sees 'xmlRegisters=' with target d50667 2 a50668 2 'qRelocInsn' This feature indicates whether GDB supports the 'qRelocInsn' d50672 1 a50672 1 'swbreak' d50677 1 a50677 1 'hwbreak' d50682 1 a50682 1 'fork-events' d50686 1 a50686 1 by including 'fork-events+' in its 'qSupported' reply. d50688 1 a50688 1 'vfork-events' d50692 1 a50692 1 by including 'vfork-events+' in its 'qSupported' reply. d50694 1 a50694 1 'exec-events' d50698 1 a50698 1 by including 'exec-events+' in its 'qSupported' reply. d50700 1 a50700 1 'vContSupported' d50702 1 a50702 1 actions in the reply to 'vCont?' packet. d50705 1 a50705 1 which sends a 'qSupported' packet supports receiving packets of d50710 1 a50710 1 'multiprocess' feature is an example of such a feature. The stub's d50719 2 a50720 2 should respond with a '+' form response. Other features require values, and the stub should respond with an '=' form response. d50723 2 a50724 2 'qSupported' is not available or if the feature is not mentioned in the 'qSupported' response. The default values are fixed; a stub is d50739 1 a50739 1 'PacketSize' Yes '-' No d50741 1 a50741 1 'qXfer:auxv:read' No '-' Yes d50743 1 a50743 1 'qXfer:btrace:read' No '-' Yes d50745 1 a50745 1 'qXfer:btrace-conf:read' No '-' Yes d50747 1 a50747 1 'qXfer:exec-file:read' No '-' Yes d50749 1 a50749 1 'qXfer:features:read' No '-' Yes d50751 1 a50751 1 'qXfer:libraries:read' No '-' Yes d50753 1 a50753 1 'qXfer:libraries-svr4:read'No '-' Yes d50755 1 a50755 1 'augmented-libraries-svr4-read'No '-' No d50757 1 a50757 1 'qXfer:memory-map:read' No '-' Yes d50759 1 a50759 1 'qXfer:sdata:read' No '-' Yes d50761 1 a50761 1 'qXfer:siginfo:read' No '-' Yes d50763 1 a50763 1 'qXfer:siginfo:write' No '-' Yes d50765 1 a50765 1 'qXfer:threads:read' No '-' Yes d50767 1 a50767 1 'qXfer:traceframe-info:read'No '-' Yes d50769 1 a50769 1 'qXfer:uib:read' No '-' Yes d50771 1 a50771 1 'qXfer:fdpic:read' No '-' Yes d50773 1 a50773 1 'Qbtrace:off' Yes '-' Yes d50775 1 a50775 1 'Qbtrace:bts' Yes '-' Yes d50777 1 a50777 1 'Qbtrace:pt' Yes '-' Yes d50779 1 a50779 1 'Qbtrace-conf:bts:size' Yes '-' Yes d50781 1 a50781 1 'Qbtrace-conf:pt:size' Yes '-' Yes d50783 1 a50783 1 'QNonStop' No '-' Yes d50785 1 a50785 1 'QCatchSyscalls' No '-' Yes d50787 1 a50787 1 'QPassSignals' No '-' Yes d50789 1 a50789 1 'QStartNoAckMode' No '-' Yes d50791 1 a50791 1 'multiprocess' No '-' No d50793 1 a50793 1 'ConditionalBreakpoints' No '-' No d50795 1 a50795 1 'ConditionalTracepoints' No '-' No d50797 1 a50797 1 'ReverseContinue' No '-' No d50799 1 a50799 1 'ReverseStep' No '-' No d50801 1 a50801 1 'TracepointSource' No '-' No d50803 1 a50803 1 'QAgent' No '-' No d50805 1 a50805 1 'QAllow' No '-' No d50807 1 a50807 1 'QDisableRandomization' No '-' No d50809 1 a50809 1 'EnableDisableTracepoints'No '-' No d50811 1 a50811 1 'QTBuffer:size' No '-' No d50813 1 a50813 1 'tracenz' No '-' No d50815 1 a50815 1 'BreakpointCommands' No '-' No d50817 1 a50817 1 'swbreak' No '-' No d50819 1 a50819 1 'hwbreak' No '-' No d50821 1 a50821 1 'fork-events' No '-' No d50823 1 a50823 1 'vfork-events' No '-' No d50825 1 a50825 1 'exec-events' No '-' No d50827 1 a50827 1 'QThreadEvents' No '-' No d50829 1 a50829 1 'QThreadOptions' Yes '-' No d50831 1 a50831 1 'no-resumed' No '-' No d50833 1 a50833 1 'memory-tagging' No '-' No d50838 1 a50838 1 'PacketSize=BYTES' d50847 1 a50847 1 guesses based on the size of the 'g' packet response. d50849 2 a50850 2 'qXfer:auxv:read' The remote stub understands the 'qXfer:auxv:read' packet d50853 2 a50854 2 'qXfer:btrace:read' The remote stub understands the 'qXfer:btrace:read' packet d50857 2 a50858 2 'qXfer:btrace-conf:read' The remote stub understands the 'qXfer:btrace-conf:read' d50861 2 a50862 2 'qXfer:exec-file:read' The remote stub understands the 'qXfer:exec-file:read' packet d50865 2 a50866 2 'qXfer:features:read' The remote stub understands the 'qXfer:features:read' packet d50869 2 a50870 2 'qXfer:libraries:read' The remote stub understands the 'qXfer:libraries:read' packet d50873 2 a50874 2 'qXfer:libraries-svr4:read' The remote stub understands the 'qXfer:libraries-svr4:read' d50877 1 a50877 1 'augmented-libraries-svr4-read' d50879 1 a50879 1 'qXfer:libraries-svr4:read' packet (*note qXfer svr4 library d50882 2 a50883 2 'qXfer:memory-map:read' The remote stub understands the 'qXfer:memory-map:read' packet d50886 2 a50887 2 'qXfer:sdata:read' The remote stub understands the 'qXfer:sdata:read' packet d50890 2 a50891 2 'qXfer:siginfo:read' The remote stub understands the 'qXfer:siginfo:read' packet d50894 2 a50895 2 'qXfer:siginfo:write' The remote stub understands the 'qXfer:siginfo:write' packet d50898 2 a50899 2 'qXfer:threads:read' The remote stub understands the 'qXfer:threads:read' packet d50902 2 a50903 2 'qXfer:traceframe-info:read' The remote stub understands the 'qXfer:traceframe-info:read' d50906 2 a50907 2 'qXfer:uib:read' The remote stub understands the 'qXfer:uib:read' packet (*note d50910 2 a50911 2 'qXfer:fdpic:read' The remote stub understands the 'qXfer:fdpic:read' packet d50914 2 a50915 2 'QNonStop' The remote stub understands the 'QNonStop' packet (*note d50918 2 a50919 2 'QCatchSyscalls' The remote stub understands the 'QCatchSyscalls' packet (*note d50922 2 a50923 2 'QPassSignals' The remote stub understands the 'QPassSignals' packet (*note d50926 2 a50927 2 'QStartNoAckMode' The remote stub understands the 'QStartNoAckMode' packet and d50931 1 a50931 1 'multiprocess' d50935 2 a50936 2 thread-id syntax::), and add process IDs to the 'D' packet and 'W' and 'X' replies. Note that reporting this feature d50941 1 a50941 1 supports them in its 'qSupported' request. d50943 2 a50944 2 'qXfer:osdata:read' The remote stub understands the 'qXfer:osdata:read' packet d50947 1 a50947 1 'ConditionalBreakpoints' d50953 1 a50953 1 'ConditionalTracepoints' d50957 1 a50957 1 'ReverseContinue' d50961 1 a50961 1 'ReverseStep' d50965 2 a50966 2 'TracepointSource' The remote stub understands the 'QTDPsrc' packet that supplies d50969 2 a50970 2 'QAgent' The remote stub understands the 'QAgent' packet. d50972 2 a50973 2 'QAllow' The remote stub understands the 'QAllow' packet. d50975 2 a50976 2 'QDisableRandomization' The remote stub understands the 'QDisableRandomization' d50979 1 a50979 1 'StaticTracepoint' d50982 1 a50982 1 'InstallInTrace' d50985 3 a50987 3 'EnableDisableTracepoints' The remote stub supports the 'QTEnable' (*note QTEnable::) and 'QTDisable' (*note QTDisable::) packets that allow tracepoints d50991 2 a50992 2 'QTBuffer:size' The remote stub supports the 'QTBuffer:size' (*note d50996 2 a50997 2 'tracenz' The remote stub supports the 'tracenz' bytecode for collecting d51001 1 a51001 1 'BreakpointCommands' d51005 2 a51006 2 'Qbtrace:off' The remote stub understands the 'Qbtrace:off' packet. d51008 2 a51009 2 'Qbtrace:bts' The remote stub understands the 'Qbtrace:bts' packet. d51011 2 a51012 2 'Qbtrace:pt' The remote stub understands the 'Qbtrace:pt' packet. d51014 2 a51015 2 'Qbtrace-conf:bts:size' The remote stub understands the 'Qbtrace-conf:bts:size' d51018 2 a51019 2 'Qbtrace-conf:pt:size' The remote stub understands the 'Qbtrace-conf:pt:size' packet. d51021 2 a51022 2 'swbreak' The remote stub reports the 'swbreak' stop reason for memory d51025 2 a51026 2 'hwbreak' The remote stub reports the 'hwbreak' stop reason for hardware d51029 2 a51030 2 'fork-events' The remote stub reports the 'fork' stop reason for fork d51033 2 a51034 2 'vfork-events' The remote stub reports the 'vfork' stop reason for vfork d51037 2 a51038 2 'exec-events' The remote stub reports the 'exec' stop reason for exec d51041 1 a51041 1 'vContSupported' d51043 1 a51043 1 'vCont?' packet. d51045 2 a51046 2 'QThreadEvents' The remote stub understands the 'QThreadEvents' packet. d51048 2 a51049 2 'QThreadOptions=SUPPORTED_OPTIONS' The remote stub understands the 'QThreadOptions' packet. d51052 1 a51052 1 as the OPTIONS parameter of the 'QThreadOptions' packet, d51055 2 a51056 2 'no-resumed' The remote stub reports the 'N' stop reply. d51058 1 a51058 1 'memory-tagging' d51060 2 a51061 2 tagging functionality and understands the 'qMemTags' (*note qMemTags::) and 'QMemTags' (*note QMemTags::) packets. d51064 2 a51065 2 to the '/proc/PID/smaps' file so memory mapping page flags can be inspected, if 'qIsAddressTagged' (*note qIsAddressTagged::) d51067 1 a51067 1 '/proc/PID/smaps' file is done via 'vFile' requests. d51069 1 a51069 1 'qSymbol::' d51075 1 a51075 1 'OK' d51077 1 a51077 1 'qSymbol:SYM_NAME' d51080 1 a51080 1 'qSymbol:SYM_VALUE:SYM_NAME' message, described below. d51082 1 a51082 1 'qSymbol:SYM_VALUE:SYM_NAME' d51092 1 a51092 1 'OK' d51094 1 a51094 1 'qSymbol:SYM_NAME' d51099 10 a51108 10 'qTBuffer' 'QTBuffer' 'QTDisconnected' 'QTDP' 'QTDPsrc' 'QTDV' 'qTfP' 'qTfV' 'QTFrame' 'qTMinFTPILen' d51112 1 a51112 1 'qThreadExtraInfo,THREAD-ID' d51117 1 a51117 1 the thread. The string is displayed in GDB's 'info threads' d51119 1 a51119 1 'Runnable', or 'Blocked on Mutex'. d51122 2 a51123 2 'XX...' Where 'XX...' is a hex encoding of ASCII data, comprising the d51127 2 a51128 2 (Note that the 'qThreadExtraInfo' packet's name is separated from the command by a ',', not a ':', contrary to the naming conventions d51131 16 a51146 16 'QTNotes' 'qTP' 'QTSave' 'qTsP' 'qTsV' 'QTStart' 'QTStop' 'QTEnable' 'QTDisable' 'QTinit' 'QTro' 'qTStatus' 'qTV' 'qTfSTM' 'qTsSTM' 'qTSTMat' d51149 1 a51149 1 'qXfer:OBJECT:read:ANNEX:OFFSET,LENGTH' d51157 1 a51157 1 'm DATA' d51160 1 a51160 1 permitted to return 'm' even for the last valid block of data, d51165 1 a51165 1 'l DATA' d51170 1 a51170 1 'l' d51175 1 a51175 1 the 'qXfer:OBJECT:read:...' requests use the same reply formats, d51178 2 a51179 2 'qXfer:auxv:read::OFFSET,LENGTH' Access the target's "auxiliary vector". *Note auxiliary d51183 1 a51183 1 request it, by supplying an appropriate 'qSupported' response d51186 1 a51186 1 'qXfer:btrace:read:ANNEX:OFFSET,LENGTH' d51189 1 a51189 1 Branch Trace Format::. The annex part of the generic 'qXfer' d51192 1 a51192 1 'all' d51195 1 a51195 1 'new' d51199 1 a51199 1 'delta' d51210 1 a51210 1 request it by supplying an appropriate 'qSupported' response d51213 1 a51213 1 'qXfer:btrace-conf:read::OFFSET,LENGTH' d51219 1 a51219 1 request it by supplying an appropriate 'qSupported' response d51222 1 a51222 1 'qXfer:exec-file:read:ANNEX:OFFSET,LENGTH' d51231 1 a51231 1 request it, by supplying an appropriate 'qSupported' response d51234 2 a51235 2 'qXfer:features:read:ANNEX:OFFSET,LENGTH' Access the "target description". *Note Target Descriptions::. d51237 1 a51237 1 description is always loaded from the 'target.xml' annex. d51240 1 a51240 1 request it, by supplying an appropriate 'qSupported' response d51243 1 a51243 1 'qXfer:libraries:read:ANNEX:OFFSET,LENGTH' d51245 1 a51245 1 List Format::. The annex part of the generic 'qXfer' packet d51254 1 a51254 1 request it, by supplying an appropriate 'qSupported' response d51257 1 a51257 1 'qXfer:libraries-svr4:read:ANNEX:OFFSET,LENGTH' d51260 1 a51260 1 Targets::. The annex part of the generic 'qXfer' packet must d51263 1 a51263 1 'qSupported' response (*note qXfer read::, *note d51271 1 a51271 1 request it, by supplying an appropriate 'qSupported' response d51275 2 a51276 2 this packet then the annex part of the generic 'qXfer' packet may contain a semicolon-separated list of 'NAME=VALUE' d51279 1 a51279 1 'start=ADDRESS' d51281 2 a51282 2 'struct link_map' to start reading the library list from. If unset or zero then the first 'struct link_map' in the d51285 1 a51285 1 'prev=ADDRESS' d51287 4 a51290 4 'struct link_map' immediately preceding the 'struct link_map' specified by the 'start' argument. If unset or zero then the remote stub will expect that no 'struct link_map' exists prior to the starting point. d51292 1 a51292 1 'lmid=LMID' d51294 1 a51294 1 This is currently only used together with 'start' to d51298 1 a51298 1 include 'lmid="0x0"'. d51303 3 a51305 3 'qXfer:memory-map:read::OFFSET,LENGTH' Access the target's "memory-map". *Note Memory Map Format::. The annex part of the generic 'qXfer' packet must be empty d51309 1 a51309 1 request it, by supplying an appropriate 'qSupported' response d51312 1 a51312 1 'qXfer:sdata:read::OFFSET,LENGTH' d51315 1 a51315 1 information. The annex part of the generic 'qXfer' packet d51320 1 a51320 1 request it, by supplying an appropriate 'qSupported' response d51323 1 a51323 1 'qXfer:siginfo:read::OFFSET,LENGTH' d51325 1 a51325 1 system. The annex part of the generic 'qXfer' packet must be d51329 1 a51329 1 request it, by supplying an appropriate 'qSupported' response d51332 1 a51332 1 'qXfer:threads:read::OFFSET,LENGTH' d51334 1 a51334 1 Format::. The annex part of the generic 'qXfer' packet must d51338 1 a51338 1 request it, by supplying an appropriate 'qSupported' response d51341 1 a51341 1 'qXfer:traceframe-info:read::OFFSET,LENGTH' d51345 1 a51345 1 'qXfer' packet must be empty (*note qXfer read::). d51348 1 a51348 1 request it, by supplying an appropriate 'qSupported' response d51351 1 a51351 1 'qXfer:uib:read:PC:OFFSET,LENGTH' d51358 4 a51361 4 'qXfer:fdpic:read:ANNEX:OFFSET,LENGTH' Read contents of 'loadmap's on the target system. The annex, either 'exec' or 'interp', specifies which 'loadmap', executable 'loadmap' or interpreter 'loadmap' to read. d51364 1 a51364 1 request it, by supplying an appropriate 'qSupported' response d51367 2 a51368 2 'qXfer:osdata:read::OFFSET,LENGTH' Access the target's "operating system information". *Note d51371 1 a51371 1 'qXfer:OBJECT:write:ANNEX:OFFSET:DATA...' d51380 1 a51380 1 'NN' d51385 1 a51385 1 the 'qXfer:OBJECT:write:...' requests use the same reply formats, d51388 1 a51388 1 'qXfer:siginfo:write::OFFSET:DATA...' d51390 1 a51390 1 system. The annex part of the generic 'qXfer' packet must be d51394 1 a51394 1 request it, by supplying an appropriate 'qSupported' response d51397 1 a51397 1 'qXfer:OBJECT:OPERATION:...' d51403 1 a51403 1 'qAttached:PID' d51409 1 a51409 1 query packet will be simplified as 'qAttached'. d51413 1 a51413 1 'quit' command. d51416 1 a51416 1 '1' d51418 1 a51418 1 '0' d51421 1 a51421 1 'Qbtrace:bts' d51426 1 a51426 1 'OK' d51429 1 a51429 1 'Qbtrace:pt' d51434 1 a51434 1 'OK' d51437 1 a51437 1 'Qbtrace:off' d51441 1 a51441 1 'OK' d51444 1 a51444 1 'Qbtrace-conf:bts:size=VALUE' d51449 1 a51449 1 'OK' d51452 1 a51452 1 'Qbtrace-conf:pt:size=VALUE' d51457 1 a51457 1 'OK' d51462 1 a51462 1 (1) The 'qP' and 'qL' packets predate these conventions, and have d51464 1 a51464 1 are in widespread use in places that are difficult to upgrade. The 'qC' d51500 1 a51500 1 These breakpoint kinds are defined for the 'Z0' and 'Z1' packets. d51517 1 a51517 1 These memory tag types are defined for the 'qMemTag' and 'QMemTag' d51543 1 a51543 1 The following 'g'/'G' packets have previously been defined. In the d51557 2 a51558 2 (including thirty-two bit registers such as 'sr'). The ordering is the same as 'MIPS32'. d51566 1 a51566 1 These breakpoint kinds are defined for the 'Z0' and 'Z1' packets. d51589 3 a51591 3 'QTDP:N:ADDR:ENA:STEP:PASS[:FFLEN][:XLEN,BYTES][-]' Create a new tracepoint, number N, at ADDR. If ENA is 'E', then the tracepoint is enabled; if it is 'D', then the tracepoint is d51593 1 a51593 1 gives its pass count. If an 'F' is present, then the tracepoint is d51596 1 a51596 1 If an 'X' is present, it introduces a tracepoint condition, which d51599 1 a51599 1 described below. If the trailing '-' is present, further 'QTDP' d51603 1 a51603 1 'OK' d51605 1 a51605 1 'qRelocInsn' d51608 1 a51608 1 'QTDP:-N:ADDR:[S]ACTION...[-]' d51610 1 a51610 1 ADDR must be the same as in the initial 'QTDP' packet for this d51612 2 a51613 2 'QTDP' packet that ended with a '-'. If the trailing '-' is present, further 'QTDP' packets will follow, specifying more d51617 1 a51617 1 can have an 'S' before its first ACTION. If such a packet is sent, d51620 1 a51620 1 the tracepoint is first hit. If no action packet has an 'S', then d51623 1 a51623 1 The 'ACTION...' portion of the packet is a series of actions, d51627 1 a51627 1 'R MASK' d51634 1 a51634 1 'M BASEREG,OFFSET,LEN' d51636 1 a51636 1 register number BASEREG, plus OFFSET. If BASEREG is '-1', d51639 1 a51639 1 parameters are all unsigned hexadecimal values (the '-1' value d51642 1 a51642 1 'X LEN,EXPR' d51650 1 a51650 1 Any number of actions may be packed together in a single 'QTDP' d51652 4 a51655 4 length (400 bytes, for many stubs). There may be only one 'R' action per tracepoint, and it must precede any 'M' or 'X' actions. Any registers referred to by 'M' and 'X' actions must be collected by a preceding 'R' action. (The "while-stepping" actions are d51660 1 a51660 1 'OK' d51662 1 a51662 1 'qRelocInsn' d51665 1 a51665 1 'QTDPsrc:N:ADDR:TYPE:START:SLEN:BYTES' d51669 1 a51669 1 of the tracepoint part, such as 'cond' for the tracepoint's d51678 2 a51679 2 The available string types are 'at' for the location, 'cond' for the conditional, and 'cmd' for an action command. GDB sends a d51684 1 a51684 1 report them back as part of the replies to the 'qTfP'/'qTsP' query d51688 1 a51688 1 target replies with 'TracepointSource' *Note General Query d51693 1 a51693 1 discrepancy could cause 'tdump' not to work, or a particular trace d51696 1 a51696 1 'QTDV:N:VALUE:BUILTIN:NAME' d51704 1 a51704 1 only sets BUILTIN to 1 if a previous 'qTfV' or 'qTsV' packet had it d51706 1 a51706 1 leading '$') of the trace state variable. d51708 1 a51708 1 'QTFrame:N' d51718 1 a51718 1 'F F' d51720 1 a51720 1 a hexadecimal number. If F is '-1', then there was no frame d51723 1 a51723 1 'T T' d51727 2 a51728 2 'QTFrame:pc:ADDR' Like 'QTFrame:N', but select the first tracepoint frame after the d51732 2 a51733 2 'QTFrame:tdp:T' Like 'QTFrame:N', but select the first tracepoint frame after the d51737 2 a51738 2 'QTFrame:range:START:END' Like 'QTFrame:N', but select the first tracepoint frame after the d51742 2 a51743 2 'QTFrame:outside:START:END' Like 'QTFrame:range:START:END', but select the first frame d51746 1 a51746 1 'qTMinFTPILen' d51757 1 a51757 1 '0' d51759 1 a51759 1 'LENGTH' d51764 1 a51764 1 'E' d51767 1 a51767 1 'QTStart' d51770 1 a51770 1 the 'qRelocInsn' reply (*note Relocate instruction reply packet: d51773 1 a51773 1 'QTStop' d51776 1 a51776 1 'QTEnable:N:ADDR' d51781 1 a51781 1 'QTDisable:N:ADDR' d51784 1 a51784 1 unless 'QTEnable:N:ADDR' is subsequently issued. d51786 1 a51786 1 'QTinit' d51789 1 a51789 1 'QTro:START1,END1:START2,END2:...' d51800 1 a51800 1 'QTDisconnected:VALUE' d51806 1 a51806 1 'qTStatus' d51811 3 a51813 3 'TRUNNING[;FIELD]...' RUNNING is a single digit '1' if the trace is presently running, or '0' if not. It is followed by semicolon-separated d51820 1 a51820 1 'tnotrun:0' d51823 1 a51823 1 'tstop[:TEXT]:0' d51829 1 a51829 1 'tfull:0' d51832 1 a51832 1 'tdisconnected:0' d51835 1 a51835 1 'tpasscount:TPNUM' d51839 1 a51839 1 'terror:TEXT:TPNUM' d51845 1 a51845 1 'tunknown:0' d51854 1 a51854 1 'tframes:N' d51857 1 a51857 1 'tcreated:N' d51862 1 a51862 1 'tsize:N' d51865 1 a51865 1 'tfree:N' d51868 2 a51869 2 'circular:N' The value of the circular trace buffer flag. '1' means that d51871 1 a51871 1 discarded if necessary to make room, '0' means that the trace d51874 3 a51876 3 'disconn:N' The value of the disconnected tracing flag. '1' means that tracing will continue after GDB disconnects, '0' means that d51879 1 a51879 1 'qTP:TP:ADDR' d51884 1 a51884 1 'VHITS:USAGE' d51887 1 a51887 1 'while-stepping' steps are not counted as separate hits, but d51890 1 a51890 1 'qTV:VAR' d51894 1 a51894 1 'VVALUE' d51902 1 a51902 1 'U' d51907 2 a51908 2 'qTfP' 'qTsP' d51910 3 a51912 3 the target. GDB sends 'qTfP' to get the first piece of data, and multiple 'qTsP' to get additional pieces. Replies to these packets generally take the form of the 'QTDP' packets that define d51915 2 a51916 2 'qTfV' 'qTsV' d51918 3 a51920 3 the target. GDB sends 'qTfV' to get the first vari of data, and multiple 'qTsV' to get additional variables. Replies to these packets follow the syntax of the 'QTDV' packets that define trace d51923 2 a51924 2 'qTfSTM' 'qTsSTM' d51926 2 a51927 2 exist in the target program. GDB sends 'qTfSTM' to get the first piece of data, and multiple 'qTsSTM' to get additional pieces. d51931 1 a51931 1 'm ADDRESS:ID:EXTRA' d51933 1 a51933 1 'm ADDRESS:ID:EXTRA,ADDRESS:ID:EXTRA...' d51935 2 a51936 2 'l' (lower case letter 'L') denotes end of list. d51943 3 a51945 3 reply with a request for more markers (using the 'qs' form of the query), until the target responds with 'l' (lower-case ell, for "last"). d51947 1 a51947 1 'qTSTMat:ADDRESS' d51950 1 a51950 1 syntax of the 'qTfSTM' and 'qTsSTM' packets that list static d51953 1 a51953 1 'QTSave:FILENAME' d51959 1 a51959 1 'qTBuffer:OFFSET,LEN' d51965 1 a51965 1 asked for. A reply consisting of just 'l' indicates that no bytes d51968 1 a51968 1 'QTBuffer:circular:VALUE' d51972 1 a51972 1 'QTBuffer:size:SIZE' d51974 1 a51974 1 SIZE if possible. A value of '-1' tells the target to use whatever d51977 1 a51977 1 'QTNotes:[TYPE:TEXT][;TYPE:TEXT]...' d51979 1 a51979 1 Allowable types include 'user', 'notes', and 'tstop', the TEXT d51995 1 a51995 1 respond with a number of intermediate 'qRelocInsn' request packets d51999 1 a51999 1 'QTStart' and 'QTDP' packets. The format of the request is: d52001 1 a52001 1 'qRelocInsn:FROM;TO' d52009 1 a52009 1 'qRelocInsn:ADJUSTED_SIZE' d52019 1 a52019 1 The "Host I/O" packets allow GDB to perform I/O operations on the far d52032 1 a52032 1 'vFile:OPERATION: PARAMETER...' d52044 1 a52044 1 'F RESULT [, ERRNO] [; ATTACHMENT]' d52054 1 a52054 1 '' d52059 1 a52059 1 'vFile:open: FILENAME, FLAGS, MODE' d52067 1 a52067 1 'vFile:close: FD' d52071 1 a52071 1 'vFile:pread: FD, COUNT, OFFSET' d52085 1 a52085 1 'vFile:pwrite: FD, OFFSET, DATA' d52088 2 a52089 2 'write' system calls, there is no separate COUNT argument; the length of DATA in the packet is used. 'vFile:pwrite' returns the d52093 1 a52093 1 'vFile:fstat: FD' d52100 1 a52100 1 'vFile:unlink: FILENAME' d52104 1 a52104 1 'vFile:readlink: FILENAME' d52114 2 a52115 2 'vFile:setfs: PID' Select the filesystem on which 'vFile' operations with FILENAME d52122 1 a52122 1 Return 0 on success, or -1 if an error occurs. If 'vFile:setfs:' d52124 1 a52124 1 the next successful 'vFile:setfs:' operation. d52133 3 a52135 3 may attempt to interrupt it by sending a 'Ctrl-C', 'BREAK' or a 'BREAK' followed by 'g', control of which is specified via GDB's 'interrupt-sequence'. d52137 2 a52138 2 The precise meaning of 'BREAK' is defined by the transport mechanism and may, in fact, be undefined. GDB does not currently define a 'BREAK' d52140 1 a52140 1 case GDB sends the 'telnet' BREAK sequence. d52142 1 a52142 1 'Ctrl-C', on the other hand, is defined and implemented for all d52144 2 a52145 2 '0x03' without any of the usual packet overhead described in the Overview section (*note Overview::). When a '0x03' byte is transmitted d52147 2 a52148 2 represent an interrupt. E.g., an 'X' packet (*note X packet::), used for binary downloads, may include an unescaped '0x03' as part of its d52151 1 a52151 1 'BREAK' followed by 'g' is also known as Magic SysRq g. When Linux d52159 1 a52159 1 packet framing instead of the single byte '0x03'. d52179 1 a52179 1 The GDB remote serial protocol includes "notifications", packets that d52186 1 a52186 1 A notification packet has the form '% DATA # CHECKSUM', where DATA is d52189 2 a52190 2 DATA never contains '$', '%' or '#' characters. Upon receiving a notification, the recipient sends no '+' or '-' to acknowledge the d52207 1 a52207 1 (Older versions of GDB ignore bytes received until they see the '$' d52214 1 a52214 1 'NAME:EVENT' d52219 1 a52219 1 'ACK' d52237 1 a52237 1 synchronous response or a '+'/'-' acknowledgment to a packet it has d52254 1 a52254 1 to report, the stub shall return an 'OK' response. At this point, GDB d52257 1 a52257 1 the final 'OK' is received . If further notification events occur, the d52294 2 a52295 2 non-stop mode, it should report that to GDB by including 'QNonStop+' in its 'qSupported' response (*note qSupported::). d52297 1 a52297 1 GDB typically sends a 'QNonStop' packet only when establishing a new d52301 1 a52301 1 GDB uses the '?' packet as necessary to probe the target state after a d52309 2 a52310 2 reporting the stop event is stopped. That is, when reporting a 'S' or 'T' response to indicate completion of a step operation, hitting a d52312 1 a52312 1 still-running threads continue to run. When reporting a 'W' or 'X' d52316 2 a52317 2 In non-stop mode, the target shall respond to the '?' packet as follows. First, any incomplete stop reply notification/'vStopped' d52321 2 a52322 2 as a synchronous reply to the '?' packet, and subsequent stop replies are sent as responses to 'vStopped' packets using the mechanism d52325 2 a52326 2 running when the target receives the '?' packet, or if the target is not attached to any process, it shall respond 'OK'. d52329 2 a52330 2 'swbreak' stop reason if software breakpoints are supported, and the 'hwbreak' stop reason if hardware breakpoints are supported (*note d52337 1 a52337 1 should be reported to the user. Note the 'swbreak' feature implies that d52348 2 a52349 2 packet, the first response expected is an acknowledgment: either '+' (to indicate the package was received correctly) or '-' (to request d52354 1 a52354 1 pipe or TCP connection), the '+'/'-' acknowledgments are redundant. It d52357 1 a52357 1 the 'QStartNoAckMode' packet; *note QStartNoAckMode::. d52360 1 a52360 1 or expect '+'/'-' protocol acknowledgments. The packet and response d52364 1 a52364 1 If the stub supports 'QStartNoAckMode' and prefers to operate in d52366 4 a52369 4 'QStartNoAckMode+' in its response to 'qSupported'; *note qSupported::. If GDB also supports 'QStartNoAckMode' and it has not been disabled via the 'set remote noack-packet off' command (*note Remote Configuration::), GDB may then send a 'QStartNoAckMode' packet to the d52371 1 a52371 1 GDB sends a final '+' acknowledgment of the stub's 'OK' response, which d52374 1 a52374 1 Note that 'set remote noack-packet' command only affects negotiation d52377 1 a52377 1 Since '+'/'-' acknowledgments are enabled by default when a new d52437 1 a52437 1 The "File I/O remote protocol extension" (short: File-I/O) allows the d52451 1 a52451 1 when GDB is waiting for a response from the 'C', 'c', 'S' or 's' d52455 1 a52455 1 is possible to interrupt File-I/O by a user interrupt ('Ctrl-C') within d52459 1 a52459 1 the latest 'C', 'c', 'S' or 's' action. That means, after finishing the d52484 1 a52484 1 The File-I/O protocol uses the 'F' packet as the request as well as d52488 1 a52488 1 previous 'C', 'c', 'S' or 's' packet. This 'F' packet contains all d52492 1 a52492 1 * A unique identifier for the requested system call. d52494 1 a52494 1 * All parameters to the system call. Pointers are given as addresses d52502 1 a52502 1 * If the parameters include pointer values to data needed as input to d52504 1 a52504 1 standard 'm' packet request. This additional communication has to d52506 1 a52506 1 other 'm' packet. d52508 1 a52508 1 * GDB translates all value from protocol representation to host d52512 1 a52512 1 * GDB calls the system call. d52514 1 a52514 1 * It then coerces datatypes back to protocol representation. d52516 1 a52516 1 * If the system call is expected to return data in buffer space d52518 1 a52518 1 transmitted to the target using a 'M' or 'X' packet. This packet d52520 1 a52520 1 any other 'M' or 'X' packet. d52522 1 a52522 1 Eventually GDB replies with another 'F' packet which contains all d52526 1 a52526 1 * Return value. d52528 1 a52528 1 * 'errno', if has been changed by the system call. d52530 1 a52530 1 * "Ctrl-C" flag. d52538 1 a52538 1 E.14.3 The 'F' Request Packet d52541 1 a52541 1 The 'F' request packet has the following format: d52543 1 a52543 1 'FCALL-ID,PARAMETER...' d52560 1 a52560 1 E.14.4 The 'F' Reply Packet d52563 1 a52563 1 The 'F' reply packet has the following format: d52565 1 a52565 1 'FRETCODE,ERRNO,CTRL-C FLAG;CALL-SPECIFIC ATTACHMENT' d52569 1 a52569 1 ERRNO is the 'errno' set by the call, in protocol-specific d52575 1 a52575 1 The CTRL-C FLAG itself consists of the character 'C': d52584 1 a52584 1 assuming 4 is the protocol-specific representation of 'EINTR'. d52589 1 a52589 1 E.14.5 The 'Ctrl-C' Message d52592 1 a52592 1 If the 'Ctrl-C' flag is set in the GDB reply packet (*note The F Reply d52594 1 a52594 1 The meaning for the target is "system call interrupted by 'SIGINT'". d52596 1 a52596 1 and return to GDB with a 'T02' packet. d52601 1 a52601 1 * The system call hasn't been performed on the host yet. d52603 1 a52603 1 * The system call on the host has been finished. d52606 1 a52606 1 the returned 'errno'. If it's the protocol representation of 'EINTR', d52608 1 a52608 1 'EINTR' handling on POSIX systems. In any other case, the target may d52614 1 a52614 1 yet, GDB may send the 'F' reply immediately, setting 'EINTR' as 'errno' d52617 1 a52617 1 This requires sending 'M' or 'X' packets as necessary. The 'F' packet d52629 2 a52630 2 GDB console is handled as any other file output operation ('write(1, ...)' or 'write(2, ...)'). Console input is handled by GDB so that d52634 2 a52635 2 * The user types 'Ctrl-c'. The behaviour is as explained above, and the 'read' system call is treated as finished. d52637 1 a52637 1 * The user presses . This is treated as end of input with a d52640 2 a52641 2 * The user types 'Ctrl-d'. This is treated as end of input. No trailing character (neither newline nor 'Ctrl-D') is appended to d52645 2 a52646 2 the 'read' call, the trailing characters are buffered in GDB until either another 'read(0, ...)' is requested by the target, or debugging d52680 1 a52680 1 'Fopen,PATHPTR/LEN,FLAGS,MODE' d52682 1 a52682 1 FLAGS is the bitwise 'OR' of the following values: d52684 1 a52684 1 'O_CREAT' d52688 2 a52689 2 'O_EXCL' When used with 'O_CREAT', if the file already exists it is an d52692 1 a52692 1 'O_TRUNC' d52694 1 a52694 1 ('O_RDWR' or 'O_WRONLY' is given) it will be truncated to zero d52697 1 a52697 1 'O_APPEND' d52700 1 a52700 1 'O_RDONLY' d52703 1 a52703 1 'O_WRONLY' d52706 1 a52706 1 'O_RDWR' d52711 1 a52711 1 MODE is the bitwise 'OR' of the following values: d52713 1 a52713 1 'S_IRUSR' d52716 1 a52716 1 'S_IWUSR' d52719 1 a52719 1 'S_IRGRP' d52722 1 a52722 1 'S_IWGRP' d52725 1 a52725 1 'S_IROTH' d52728 1 a52728 1 'S_IWOTH' d52734 1 a52734 1 'open' returns the new file descriptor or -1 if an error occurred. d52738 2 a52739 2 'EEXIST' PATHNAME already exists and 'O_CREAT' and 'O_EXCL' were used. d52741 1 a52741 1 'EISDIR' d52744 1 a52744 1 'EACCES' d52747 1 a52747 1 'ENAMETOOLONG' d52750 1 a52750 1 'ENOENT' d52753 1 a52753 1 'ENODEV' d52756 1 a52756 1 'EROFS' d52760 1 a52760 1 'EFAULT' d52763 1 a52763 1 'ENOSPC' d52766 1 a52766 1 'EMFILE' d52769 1 a52769 1 'ENFILE' d52773 1 a52773 1 'EINTR' d52786 1 a52786 1 'Fclose,FD' d52789 1 a52789 1 'close' returns zero on success, or -1 if an error occurred. d52793 1 a52793 1 'EBADF' d52796 1 a52796 1 'EINTR' d52809 1 a52809 1 'Fread,FD,BUFPTR,COUNT' d52818 1 a52818 1 'EBADF' d52821 1 a52821 1 'EFAULT' d52824 1 a52824 1 'EINTR' d52837 1 a52837 1 'Fwrite,FD,BUFPTR,COUNT' d52845 1 a52845 1 'EBADF' d52848 1 a52848 1 'EFAULT' d52851 1 a52851 1 'EFBIG' d52855 1 a52855 1 'ENOSPC' d52858 1 a52858 1 'EINTR' d52871 1 a52871 1 'Flseek,FD,OFFSET,FLAG' d52875 1 a52875 1 'SEEK_SET' d52878 1 a52878 1 'SEEK_CUR' d52881 1 a52881 1 'SEEK_END' d52891 1 a52891 1 'EBADF' d52894 1 a52894 1 'ESPIPE' d52897 1 a52897 1 'EINVAL' d52900 1 a52900 1 'EINTR' d52913 1 a52913 1 'Frename,OLDPATHPTR/LEN,NEWPATHPTR/LEN' d52920 1 a52920 1 'EISDIR' d52924 1 a52924 1 'EEXIST' d52927 1 a52927 1 'EBUSY' d52931 1 a52931 1 'EINVAL' d52935 1 a52935 1 'ENOTDIR' d52940 1 a52940 1 'EFAULT' d52943 1 a52943 1 'EACCES' d52946 1 a52946 1 'ENAMETOOLONG' d52950 1 a52950 1 'ENOENT' d52953 1 a52953 1 'EROFS' d52956 1 a52956 1 'ENOSPC' d52960 1 a52960 1 'EINTR' d52973 1 a52973 1 'Funlink,PATHNAMEPTR/LEN' d52980 1 a52980 1 'EACCES' d52983 1 a52983 1 'EPERM' d52986 1 a52986 1 'EBUSY' d52990 1 a52990 1 'EFAULT' d52993 1 a52993 1 'ENAMETOOLONG' d52996 1 a52996 1 'ENOENT' d52999 1 a52999 1 'ENOTDIR' d53002 1 a53002 1 'EROFS' d53005 1 a53005 1 'EINTR' d53019 2 a53020 2 'Fstat,PATHNAMEPTR/LEN,BUFPTR' 'Ffstat,FD,BUFPTR' d53027 1 a53027 1 'EBADF' d53030 1 a53030 1 'ENOENT' d53034 1 a53034 1 'ENOTDIR' d53037 1 a53037 1 'EFAULT' d53040 1 a53040 1 'EACCES' d53043 1 a53043 1 'ENAMETOOLONG' d53046 1 a53046 1 'EINTR' d53059 1 a53059 1 'Fgettimeofday,TVPTR,TZPTR' d53066 1 a53066 1 'EINVAL' d53069 1 a53069 1 'EFAULT' d53082 1 a53082 1 'Fisatty,FD' d53089 1 a53089 1 'EINTR' d53092 1 a53092 1 Note that the 'isatty' call is treated as a special case: it returns d53095 1 a53095 1 'ioctl' and would be more complex than needed. d53107 1 a53107 1 'Fsystem,COMMANDPTR/LEN' d53114 2 a53115 2 command is returned, which is extracted from the host's 'system' return value by calling 'WEXITSTATUS(retval)'. In case '/bin/sh' d53120 1 a53120 1 'EINTR' d53124 1 a53124 1 perform the 'system' call. The return value of 'system' on the host is d53129 3 a53131 3 Due to security concerns, the 'system' call is by default refused by GDB. The user has to allow this call explicitly with the 'set remote system-call-allowed 1' command. d53133 2 a53134 2 'set remote system-call-allowed' Control whether to allow the 'system' calls in the File I/O d53137 2 a53138 2 'show remote system-call-allowed' Show whether the 'system' calls are allowed in the File I/O d53161 2 a53162 2 The integral datatypes used in the system calls are 'int', 'unsigned int', 'long', 'unsigned long', 'mode_t', and 'time_t'. d53164 1 a53164 1 'int', 'unsigned int', 'mode_t' and 'time_t' are implemented as 32 d53167 1 a53167 1 'long' and 'unsigned long' are implemented as 64 bit types. d53170 1 a53170 1 those in 'limits.h') to allow range checking on host and target. d53172 1 a53172 1 'time_t' datatypes are defined as seconds since the Epoch. d53175 1 a53175 1 of a structured datatype e.g. a 'struct stat' have to be given in big d53193 1 a53193 1 trailing null byte. For example, the string '"hello world"' at address d53205 1 a53205 1 example, a 'struct stat') is expected to be in a protocol-specific d53208 1 a53208 1 before the 'F' packet is sent, and by GDB before it transfers memory to d53218 1 a53218 1 The buffer of type 'struct stat' used by the target and GDB is defined d53244 1 a53244 1 'st_dev' d53247 1 a53247 1 'st_ino' d53250 1 a53250 1 'st_mode' d53254 3 a53256 3 'st_uid' 'st_gid' 'st_rdev' d53259 3 a53261 3 'st_atime' 'st_mtime' 'st_ctime' d53266 1 a53266 1 The target gets a 'struct stat' of the above representation and is d53271 1 a53271 1 protocol representations of 'struct stat' members, these members could d53280 1 a53280 1 The buffer of type 'struct timeval' used by the File-I/O protocol is d53375 1 a53375 1 'EUNKNOWN' is used as a fallback error value if a host system returns d53429 1 a53429 1 invalid file descriptor ('EBADF'): d53434 1 a53434 1 Example sequence of a read call, user presses 'Ctrl-c' before syscall d53441 1 a53441 1 Example sequence of a read call, user presses 'Ctrl-c' after syscall d53454 1 a53454 1 On some platforms, a dynamic loader (e.g. 'ld.so') runs in the same d53460 1 a53460 1 'qXfer:libraries:read' packet (*note qXfer library list read::) instead. d53464 1 a53464 1 The 'qXfer:libraries:read' packet returns an XML document which lists d53522 1 a53522 1 'ld.so') and normal memory operations to maintain a list of shared d53526 1 a53526 1 The 'qXfer:libraries-svr4:read' packet returns an XML document which d53530 3 a53532 3 - 'name', the absolute file name from the 'l_name' field of 'struct link_map'. - 'lm' with address of 'struct link_map' used for TLS (Thread Local d53534 2 a53535 2 - 'l_addr', the displacement as read from the field 'l_addr' of 'struct link_map'. For prelinked libraries this is not an absolute d53538 3 a53540 3 - 'l_ld', which is memory address of the 'PT_DYNAMIC' segment - 'lmid', which is an identifier for a linker namespace, such as the memory address of the 'r_debug' object that contains this d53542 1 a53542 1 'dlinfo (3)'. d53544 2 a53545 2 Additionally the single 'main-lm' attribute specifies address of 'struct link_map' used for the main executable. This parameter is used d53583 1 a53583 1 The memory map is obtained using the 'qXfer:memory-map:read' (*note d53602 1 a53602 1 * A region of RAM starting at ADDR and extending for LENGTH bytes d53607 1 a53607 1 * A region of read-only memory: d53611 1 a53611 1 * A region of flash memory, with erasure blocks BLOCKSIZE bytes in d53619 1 a53619 1 covered by the memory map are RAM, and uses the ordinary 'M' and 'X' d53649 1 a53649 1 issues the 'qXfer:threads:read' packet (*note qXfer threads read::) and d53659 2 a53660 2 Each 'thread' element must have the 'id' attribute that identifies the thread (*note thread-id syntax::). The 'core' attribute, if d53662 3 a53664 3 on. The 'name' attribute, if present, specifies the human-readable name of the thread. The content of the of 'thread' element is interpreted as human-readable auxiliary information. The 'handle' attribute, if d53678 1 a53678 1 This list is obtained using the 'qXfer:traceframe-info:read' (*note d53696 1 a53696 1 * A region of collected memory starting at ADDR and extending for d53701 1 a53701 1 * A block indicating trace state variable numbered NUMBER has been d53728 1 a53728 1 This list is obtained using the 'qXfer:btrace:read' (*note qXfer d53744 1 a53744 1 * A block of sequentially executed instructions starting at BEGIN and d53777 1 a53777 1 using the 'qXfer:btrace-conf:read' (*note qXfer btrace-conf read::) d53783 3 a53785 3 'bts' This thread uses the "Branch Trace Store" (BTS) format. 'size' d53787 3 a53789 3 'pt' This thread uses the "Intel Processor Trace" (Intel PT) format. 'size' d53820 1 a53820 1 Using GDB's 'trace' and 'collect' commands, the user can specify d53822 1 a53822 1 those locations are reached. Later, using the 'tfind' command, she can d53831 1 a53831 1 When GDB is debugging a remote target, the GDB "agent" code running d53865 2 a53866 2 instruction is one byte long (thus the term "bytecode"). Some instructions are followed by operand bytes; for example, the 'goto' d53883 1 a53883 1 where 'LONGEST' and 'DOUBLEST' are 'typedef' names for the largest d53888 1 a53888 1 the stack. For tracing applications, 'trace' bytecodes in the d53894 1 a53894 1 'pc' d53897 1 a53897 1 'start' d53899 1 a53899 1 interpreting the 'goto' and 'if_goto' instructions. d53915 1 a53915 1 memory reference instructions ('ref'N) d53918 1 a53918 1 full-size integers. They may need to be sign-extended; the 'ext' d53921 1 a53921 1 the sign-extension instruction ('ext' N) d53934 3 a53936 3 instructions; for example, the expression 'x + y * z' would typically produce code like the following, assuming that 'x' and 'y' live in registers, and 'z' is a global variable holding a 32-bit 'int': d53948 2 a53949 2 'reg 1' Push the value of register 1 (presumably holding 'x') onto the d53952 2 a53953 2 'reg 2' Push the value of register 2 (holding 'y'). d53955 2 a53956 2 'const32 address of z' Push the address of 'z' onto the stack. d53958 1 a53958 1 'ref32' d53961 1 a53961 1 the address of 'z' with 'z''s value. d53963 1 a53963 1 'ext 32' d53965 1 a53965 1 length. This is necessary because 'z' is a signed integer. d53967 1 a53967 1 'mul' d53970 1 a53970 1 expression 'y * z'. d53972 1 a53972 1 'add' d53974 1 a53974 1 of the stack contains the value of 'x + y * z'. d53976 1 a53976 1 'end' d53988 1 a53988 1 'add' (0x02): A B => A+B d53993 1 a53993 1 In this example, 'add' is the name of the bytecode, and '(0x02)' is d53995 1 a53995 1 phrase "A B => A+B" shows the stack before and after the bytecode d54005 1 a54005 1 'const8' (0x22) N: => N d54009 2 a54010 2 In this example, the bytecode 'const8' takes an operand N directly from the bytecode stream; the operand follows the 'const8' bytecode d54015 2 a54016 2 For the 'const8' bytecode, there are no stack items given before the =>; this simply means that the bytecode consumes no values from the d54018 1 a54018 1 list on either side of the => may be empty. d54029 1 a54029 1 'float' (0x01): => d54033 1 a54033 1 'add' (0x02): A B => A+B d54036 1 a54036 1 'sub' (0x03): A B => A-B d54040 1 a54040 1 'mul' (0x04): A B => A*B d54046 1 a54046 1 'div_signed' (0x05): A B => A/B d54051 1 a54051 1 'div_unsigned' (0x06): A B => A/B d54056 1 a54056 1 'rem_signed' (0x07): A B => A MODULO B d54061 1 a54061 1 'rem_unsigned' (0x08): A B => A MODULO B d54066 1 a54066 1 'lsh' (0x09): A B => A< '(signed)'A>>B d54076 1 a54076 1 'rsh_unsigned' (0x0b): A B => A>>B d54081 1 a54081 1 'log_not' (0x0e): A => !A d54085 2 a54086 2 'bit_and' (0x0f): A B => A&B Pop two integers from the stack, and push their bitwise 'and'. d54088 2 a54089 2 'bit_or' (0x10): A B => A|B Pop two integers from the stack, and push their bitwise 'or'. d54091 1 a54091 1 'bit_xor' (0x11): A B => A^B d54093 1 a54093 1 exclusive-'or'. d54095 1 a54095 1 'bit_not' (0x12): A => ~A d54098 1 a54098 1 'equal' (0x13): A B => A=B d54102 1 a54102 1 'less_signed' (0x14): A B => A A A, sign-extended from N bits d54121 1 a54121 1 byte unsigned integer following the 'ext' bytecode. d54123 1 a54123 1 'zero_ext' (0x2a) N: A => A, zero-extended from N bits d54128 1 a54128 1 byte unsigned integer following the 'zero_ext' bytecode. d54130 5 a54134 5 'ref8' (0x17): ADDR => A 'ref16' (0x18): ADDR => A 'ref32' (0x19): ADDR => A 'ref64' (0x1a): ADDR => A Pop an address ADDR from the stack. For bytecode 'ref'N, fetch an d54138 1 a54138 1 Note that ADDR may not be aligned in any particular way; the 'refN' d54144 5 a54148 5 'ref_float' (0x1b): ADDR => D 'ref_double' (0x1c): ADDR => D 'ref_long_double' (0x1d): ADDR => D 'l_to_d' (0x1e): A => D 'd_to_l' (0x1f): D => A d54151 1 a54151 1 'dup' (0x28): A => A A d54154 1 a54154 1 'swap' (0x2b): A B => B A d54157 1 a54157 1 'pop' (0x29): A => d54160 1 a54160 1 'pick' (0x32) N: A ... B => A ... B A d54163 1 a54163 1 is zero, this is the same as 'dup'; if N is one, it copies the item d54167 1 a54167 1 'rot' (0x33): A B C => C A B d54172 1 a54172 1 'if_goto' (0x20) OFFSET: A => d54176 1 a54176 1 non-zero, set the 'pc' register to 'start' + OFFSET. Thus, an d54180 1 a54180 1 immediately following the 'if_goto' bytecode. It is always stored d54187 10 a54196 10 'goto' (0x21) OFFSET: => Branch unconditionally to OFFSET; in other words, set the 'pc' register to 'start' + OFFSET. The offset is stored in the same way as for the 'if_goto' bytecode. 'const8' (0x22) N: => N 'const16' (0x23) N: => N 'const32' (0x24) N: => N 'const64' (0x25) N: => N d54199 1 a54199 1 value, and then sign-extend it using the 'ext' bytecode. d54202 1 a54202 1 following the 'const'B bytecode. The constant N is always stored d54209 1 a54209 1 'reg' (0x26) N: => A d54214 1 a54214 1 immediately following the 'reg' bytecode. It is always stored most d54221 1 a54221 1 'getv' (0x2c) N: => V d54226 1 a54226 1 immediately following the 'getv' bytecode. It is always stored d54233 1 a54233 1 'setv' (0x2d) N: V => V d54237 1 a54237 1 handling of N is as described for 'getv'. d54239 1 a54239 1 'trace' (0x0c): ADDR SIZE => d54243 1 a54243 1 'trace_quick' (0x0d) SIZE: ADDR => ADDR d54246 1 a54246 1 following the 'trace' opcode. d54248 2 a54249 2 This bytecode is equivalent to the sequence 'dup const8 SIZE trace', but we provide it anyway to save space in bytecode strings. d54251 1 a54251 1 'trace16' (0x30) SIZE: ADDR => ADDR d54254 1 a54254 1 been named 'trace_quick16', for consistency. d54256 1 a54256 1 'tracev' (0x2e) N: => A d54258 1 a54258 1 buffer. The handling of N is as described for 'getv'. d54260 1 a54260 1 'tracenz' (0x2f) ADDR SIZE => d54265 2 a54266 2 'printf' (0x34) NUMARGS STRING => Do a formatted print, in the style of the C function 'printf'). d54272 1 a54272 1 '"\t%d\n"' is six characters long, and the output will consist of a d54277 1 a54277 1 as a first argument, as with the C function 'fprintf'. If the d54282 1 a54282 1 'end' (0x27): => d54306 1 a54306 1 in addition to bytecodes that do the calculation, GDB adds 'trace' d54309 1 a54309 1 * The user selects trace points in the program's code at which GDB d54312 1 a54312 1 * The user specifies expressions to evaluate at each trace point. d54317 1 a54317 1 * GDB transmits the tracepoints and their associated expressions to d54320 1 a54320 1 * The agent arranges to be notified when a trace point is hit. d54322 1 a54322 1 * When execution on the target reaches a trace point, the agent d54326 1 a54326 1 * Later, when the user selects a given trace event and inspects the d54339 1 a54339 1 have to deal with 'long long' operations. Also, different targets will d54350 1 a54350 1 * whether floating point is supported d54352 1 a54352 1 * whether 'long long' is supported d54354 1 a54354 1 * maximum acceptable size of bytecode stack d54356 1 a54356 1 * maximum acceptable length of bytecode expressions d54358 1 a54358 1 * which registers are actually available for collection d54360 1 a54360 1 * whether the target supports disabled tracepoints d54398 1 a54398 1 Why don't you have '>' or '<=' operators? d54400 1 a54400 1 can combine the 'less_' opcodes with 'log_not', and swap the order d54402 2 a54403 2 operators. For example, '(x <= y)' is '! (x > y)', which is '! (y < x)'. d54405 3 a54407 3 Why do you have 'log_not'? Why do you have 'ext'? Why do you have 'zero_ext'? d54412 1 a54412 1 'log_not' is equivalent to 'const8 0 equal'; it's used in half the d54415 2 a54416 2 'ext N' is equivalent to 'const8 S-N lsh const8 S-N rsh_signed', where S is the size of the stack elements; it follows 'refM' and d54420 1 a54420 1 'zero_ext N' is equivalent to 'constM MASK log_and'; it's used d54424 7 a54430 7 Why not have sign-extending variants of the 'ref' operators? Because that would double the number of 'ref' operators, and we need the 'ext' bytecode anyway for accessing bitfields. Why not have constant-address variants of the 'ref' operators? Because that would double the number of 'ref' operators again, and 'const32 ADDRESS ref32' is only one byte longer. d54432 1 a54432 1 Why do the 'refN' operators have to support unaligned fetches? d54455 1 a54455 1 Why aren't the 'goto' ops PC-relative? d54459 1 a54459 1 Why is there only one offset size for the 'goto' ops? d54482 1 a54482 1 Why does the 'reg' bytecode take a 16-bit register number? d54488 1 a54488 1 Why do we need 'trace' and 'trace_quick'? d54491 2 a54492 2 'x->y->z', the agent must record the values of 'x' and 'x->y' as well as the value of 'x->y->z'. d54494 1 a54494 1 Don't the 'trace' bytecodes make the interpreter less general? d54497 1 a54497 1 purpose. If an expression doesn't use the 'trace' bytecodes, they d54500 1 a54500 1 Why doesn't 'trace_quick' consume its arguments the way everything else does? d54503 3 a54505 3 rearrangement necessary. However, 'trace_quick' is a kludge to save space; it only exists so we needn't write 'dup const8 SIZE trace' before every memory reference. Therefore, it's okay for it d54510 1 a54510 1 Why does 'trace16' exist? d54513 2 a54514 2 objects that large will be quite rare, so it is okay to use 'dup const16 SIZE trace' in those cases. d54516 1 a54516 1 Whatever we decide to do with 'trace16', we should at least leave d54534 1 a54534 1 * With so many different customized processors, it is difficult for d54536 1 a54536 1 * Since individual variants may have short lifetimes or limited d54539 1 a54539 1 * When GDB does support the architecture of the embedded system at d54541 1 a54541 1 'set architecture' command can be error-prone. d54570 3 a54572 3 using 'qXfer' requests (*note qXfer: General Query Packets.). The ANNEX in the 'qXfer' packet will be 'target.xml'. The contents of the 'target.xml' annex are an XML document, of the form described in *note d54579 1 a54579 1 'set tdesc filename PATH' d54582 1 a54582 1 'unset tdesc filename' d54586 1 a54586 1 'show tdesc filename' d54597 2 a54598 2 sources in 'gdb/features/gdb-target.dtd'. This means you can use generally available tools like 'xmllint' to check that your feature d54635 1 a54635 1 'version' attribute for '' may also be omitted, but we recommend d54637 1 a54637 1 'gdb-target.dtd', they will detect and report the version mismatch. d54652 1 a54652 1 that document. If the current description was read using 'qXfer', then d54661 1 a54661 1 An '' element has this form: d54665 2 a54666 2 ARCH is one of the architectures from the set accepted by 'set architecture' (*note Specifying a Debugging Target: Targets.). d54674 1 a54674 1 An '' element has this form: d54679 1 a54679 1 'set osabi' (*note Configuring the Current ABI: ABI.). d54687 1 a54687 1 A '' element has this form: d54691 2 a54692 2 ARCH is one of the architectures from the set accepted by 'set architecture' (*note Specifying a Debugging Target: Targets.). d54694 1 a54694 1 A '' element is used to specify that the target is able d54696 4 a54699 4 the '' element. For example, on the Cell Broadband Engine, the main architecture is 'powerpc:common' or 'powerpc:common64', but the system is able to run binaries in the 'spu' architecture as well. The way to describe this capability with '' is as d54708 1 a54708 1 Each '' describes some logical portion of the target system. d54710 1 a54710 1 types of their contents. A '' element has this form: d54731 2 a54732 2 Each type element must have an 'id' attribute, which gives a unique (within the containing '') name to the type. Types must be d54736 1 a54736 1 of scalar elements. These types are written as '' elements, d54743 2 a54744 2 with a union type containing the useful representations. The '' element contains one or more '' elements, each of which has a d54781 1 a54781 1 empty string, '""', in which case the field is "filler" and its value is d54789 1 a54789 1 The default value of TYPE is 'bool' for single bit fields, and an d54794 2 a54795 2 Registers defined with 'flags' have these advantages over defining them with 'struct': d54797 2 a54798 2 * Arithmetic may be performed on them as if they were integers. * They are printed in a more readable fashion. d54800 2 a54801 2 Registers defined with 'struct' have one advantage over defining them with 'flags': d54803 1 a54803 1 * One can fetch individual fields like in 'C'. d54834 2 a54835 2 to read or write the register; e.g. it is used in the remote 'p' and 'P' packets, and registers appear in the 'g' and 'G' packets in d54840 1 a54840 1 calls; this must be either 'yes' or 'no'. The default is 'yes', d54846 3 a54848 3 defined in the current feature, or one of the special types 'int' and 'float'. 'int' is an integer type of the correct size for BITSIZE, and 'float' is a floating point type (in the d54850 1 a54850 1 for BITSIZE. The default is 'int'. d54854 1 a54854 1 of the standard register groups 'general', 'float', 'vector' or an d54857 3 a54859 3 may be separated by hyphens; e.g. 'special-group' or 'ultra-special-group'. If no GROUP is specified, GDB will not display the register in 'info registers'. d54872 1 a54872 1 'bool' d54875 6 a54880 6 'int8' 'int16' 'int24' 'int32' 'int64' 'int128' d54883 6 a54888 6 'uint8' 'uint16' 'uint24' 'uint32' 'uint64' 'uint128' d54891 2 a54892 2 'code_ptr' 'data_ptr' d54899 1 a54899 1 'ieee_half' d54902 1 a54902 1 'ieee_single' d54905 1 a54905 1 'ieee_double' d54908 2 a54909 2 'bfloat16' The 16-bit "brain floating point" format used e.g. by x86 and ARM. d54911 1 a54911 1 'arm_fpa_ext' d54914 1 a54914 1 'i387_ext' d54917 1 a54917 1 'i386_eflags' d54920 1 a54920 1 'i386_mxcsr' d54929 1 a54929 1 Enum target types are useful in 'struct' and 'flags' register d54951 1 a54951 1 Given that description, a value of 3 for the 'flags' register would d54980 1 a54980 1 tree, in the directory 'gdb/features'. d54985 1 a54985 1 registers is named 'org.gnu.gdb.arm.core'. d55020 1 a55020 1 The 'org.gnu.gdb.aarch64.core' feature is required for AArch64 targets. d55023 8 a55030 8 - 'x0' through 'x30', the general purpose registers, with size of 64 bits. Register 'x30' is also known as the "link register", or 'lr'. - 'sp', the stack pointer register or 'x31'. It is 64 bits in size and has a type of 'data_ptr'. - 'pc', the program counter register. It is 64 bits in size and has a type of 'code_ptr'. - 'cpsr', the current program status register. It is 32 bits in size d55033 1 a55033 1 The semantics of the individual flags and fields in 'cpsr' can change d55043 1 a55043 1 The 'org.gnu.gdb.aarch64.fpu' feature is optional. If present, it must d55046 1 a55046 1 - 'v0' through 'v31', the vector registers with size of 128 bits. d55048 1 a55048 1 - 'fpsr', the floating-point status register. It is 32 bits in size d55050 1 a55050 1 - 'fpcr', the floating-point control register. It is 32 bits in size d55053 1 a55053 1 The semantics of the individual flags and fields in 'fpsr' and 'fpcr' d55056 1 a55056 1 The types for the vector registers, 'fpsr' and 'fpcr' registers can d55065 1 a55065 1 The 'org.gnu.gdb.aarch64.sve' feature is optional. If present, it means d55069 1 a55069 1 - 'z0' through 'z31', the scalable vector registers. Their sizes are d55073 1 a55073 1 - 'fpsr', the floating-point status register. It is 32 bits in size d55075 1 a55075 1 - 'fpcr', the floating-point control register. It is 32 bits in size d55077 1 a55077 1 - 'p0' through 'p15', the predicate registers. Their sizes are d55081 1 a55081 1 - 'ffr', the First Fault register. It has a variable size based on d55084 3 a55086 3 - 'vg', the vector granule. It represents the number of 64 bits chunks in a 'z' register. It is closely associated with the current vector length. It has a type of 'int'. d55089 2 a55090 2 Extension is supported, and will adjust the sizes of the 'z', 'p' and 'ffr' registers accordingly, based on the value of 'vg'. d55092 2 a55093 2 GDB will also create pseudo-registers equivalent to the 'v' vector registers from the 'org.gnu.gdb.aarch64.fpu' feature. d55095 2 a55096 2 The first 128 bits of the 'z' registers overlap the 128 bits of the 'v' registers, so changing one will trigger a change to the other. d55098 1 a55098 1 For the types of the 'z', 'p' and 'ffr' registers, please check the d55102 1 a55102 1 The semantics of the individual flags and fields in 'fpsr' and 'fpcr' d55105 1 a55105 1 The types for the 'fpsr' and 'fpcr' registers can be found in the d55115 1 a55115 1 The 'org.gnu.gdb.aarch64.pauth' optional feature was introduced so GDB d55121 1 a55121 1 - 'pauth_dmask', the user-mode pointer authentication mask for data d55123 1 a55123 1 - 'pauth_cmask', the user-mode pointer authentication mask for code d55128 1 a55128 1 - 'pauth_dmask', the user-mode pointer authentication mask for data d55130 1 a55130 1 - 'pauth_cmask', the user-mode pointer authentication mask for code d55132 1 a55132 1 - 'pauth_dmask_high', the kernel-mode pointer authentication mask for d55134 1 a55134 1 - 'pauth_cmask_high', the kernel-mode pointer authentication mask for d55139 1 a55139 1 decorate backtraces with a '[PAC]' marker alongside a function that has d55147 1 a55147 1 Please note the 'org.gnu.gdb.aarch64.pauth' feature string is d55149 1 a55149 1 releases of GDB and 'gdbserver'. Targets that support Pointer d55151 1 a55151 1 'org.gnu.gdb.aarch64.pauth_v2' feature string instead. d55153 2 a55154 2 The 'org.gnu.gdb.aarch64.pauth_v2' feature has the exact same contents as feature 'org.gnu.gdb.aarch64.pauth'. d55156 1 a55156 1 The reason for having feature 'org.gnu.gdb.aarch64.pauth_v2' is a bug d55159 1 a55159 1 Authentication (using feature string 'org.gnu.gdb.aarch64.pauth') and d55166 1 a55166 1 Authentication support via the 'org.gnu.gdb.aarch64.pauth' feature d55173 1 a55173 1 The 'org.gnu.gdb.aarch64.tls' optional feature was introduced to expose d55177 1 a55177 1 Only 'tpidr': d55179 2 a55180 2 - 'tpidr', the software thread id register. It is 64 bits in size and has a type of 'data_ptr'. d55182 1 a55182 1 Both 'tpidr' and 'tpidr2'. d55184 4 a55187 4 - 'tpidr', the software thread id register. It is 64 bits in size and has a type of 'data_ptr'. - 'tpidr2', the second software thread id register. It is 64 bits in size and has a type of 'data_ptr'. It may be used in the future d55191 1 a55191 1 variations of the register set. If 'tpidr2' is available, GDB may act d55194 1 a55194 1 There is no XML for this feature as the presence of 'tpidr2' is d55203 1 a55203 1 The 'org.gnu.gdb.aarch64.mte' optional feature was introduced so GDB d55208 2 a55209 2 - 'tag_ctl', the tag control register. It is 64 bits in size and has a type of 'uint64'. d55223 2 a55224 2 The 'org.gnu.gdb.aarch64.sme' feature is optional. If present, it should contain registers 'ZA', 'SVG' and 'SVCR'. *Note AArch64 SME::. d55226 1 a55226 1 - 'ZA' is a register represented by a vector of SVLxSVL bytes. *Note d55229 1 a55229 1 - 'SVG' is a 64-bit register containing the value of SVG. *Note d55232 1 a55232 1 - 'SVCR' is a 64-bit status pseudo-register with two valid bits. Bit d55234 1 a55234 1 Bit 1 (ZA) shows whether the 'ZA' register state is active (in use) d55237 1 a55237 1 The rest of the unused bits of the 'SVCR' pseudo-register is d55244 2 a55245 2 The 'org.gnu.gdb.aarch64.sme' feature is required when the target also reports support for the 'org.gnu.gdb.aarch64.sme2' feature. d55250 3 a55252 3 The 'org.gnu.gdb.aarch64.sme2' feature is optional. If present, then the 'org.gnu.gdb.aarch64.sme' feature must also be present. The 'org.gnu.gdb.aarch64.sme2' feature should contain the following: *Note d55255 1 a55255 1 - 'ZT0' is a register of 512 bits (64 bytes). It is defined as a d55271 1 a55271 1 'org.gnu.gdb.arc.core' and 'org.gnu.gdb.arc.aux'. d55273 1 a55273 1 The 'org.gnu.gdb.arc.core' feature is required for all targets. It d55276 2 a55277 2 - 'r0' through 'r25' for normal register file targets. - 'r0' through 'r3', and 'r10' through 'r15' for reduced register d55279 1 a55279 1 - 'gp', 'fp', 'sp', 'r30'(1), 'blink', 'lp_count', 'pcl'. d55282 7 a55288 7 'org.gnu.gdb.arc.core' feature may contain registers 'ilink1' and 'ilink2'. While in case of ARC EM and ARC HS targets (ARCv2 ISA), register 'ilink' may be present. The difference between ARCv1 and ARCv2 is the naming of registers _29th_ and _30th_. They are called 'ilink1' and 'ilink2' for ARCv1 and are optional. For ARCv2, they are called 'ilink' and 'r30' and only 'ilink' is optional. The optionality of 'ilink*' registers is because of their inaccessibility during user space d55291 1 a55291 1 Extension core registers 'r32' through 'r59' are optional and their d55296 1 a55296 1 The 'org.gnu.gdb.arc.aux' feature is required for all ARC targets. d55299 2 a55300 2 - mandatory: 'pc' and 'status32'. - optional: 'lp_start', 'lp_end', and 'bta'. d55315 1 a55315 1 The 'org.gnu.gdb.arm.core' feature is required for non-M-profile ARM d55318 8 a55325 8 - 'r0' through 'r12'. The general purpose registers. They are 32 bits in size and have a type of 'uint32'. - 'sp', the stack pointer register, also known as 'r13'. It is 32 bits in size and has a type of 'data_ptr'. - 'lr', the link register. It is 32 bits in size. - 'pc', the program counter register. It is 32 bit in size and of type 'code_ptr'. - 'cpsr', the current program status register containing all the d55336 2 a55337 2 For M-profile targets (e.g. Cortex-M3), the 'org.gnu.gdb.arm.core' feature is replaced by 'org.gnu.gdb.arm.m-profile', and it is a required d55340 8 a55347 8 - 'r0' through 'r12', the general purpose registers. They have a size of 32 bits and a type of 'uint32'. - 'sp', the stack pointer register, also known as 'r13'. It has a size of 32 bits and a type of 'data_ptr'. - 'lr', the link register. It has a size of 32 bits. - 'pc', the program counter register. It has a size of 32 bits and a type of 'code_ptr'. - 'xpsr', the program status register containing all the status bits. d55362 1 a55362 1 The 'org.gnu.gdb.arm.fpa' feature is obsolete and should not be d55375 2 a55376 2 - 'f0' through 'f8'. The floating point registers. They are 96 bits in size and of type 'arm_fpa_ext'. 'f0' is pinned to register d55378 1 a55378 1 - 'fps', the status register. It has a size of 32 bits. d55384 1 a55384 1 the optional 'org.gnu.gdb.arm.m-profile-mve' feature. d55388 1 a55388 1 - 'vpr', the vector predication status and control register. It is d55390 2 a55391 2 laid out in a way that exposes the 'P0' field from bits 0 to 15, the 'MASK01' field from bits 16 to 19 and the 'MASK23' field from d55396 2 a55397 2 When this feature is available, GDB will synthesize the 'p0' pseudo-register from 'vpr' contents. d55403 3 a55405 3 If the 'org.gnu.gdb.arm.vfp' feature is available alongside the 'org.gnu.gdb.arm.m-profile-mve' feature, GDB will synthesize the 'q' pseudo-registers from 'd' register contents. d55413 1 a55413 1 The XScale 'org.gnu.gdb.xscale.iwmmxt' feature is optional. If present, d55416 6 a55421 6 - 'wR0' through 'wR15', registers with size 64 bits and a custom type 'iwmmxt_vec64i'. 'iwmmxt_vec64i' is a union of four other types: 'uint64', a 2-element vector of 'uint32', a 4-element vector of 'uint16' and a 8-element vector of 'uint8'. - 'wCGR0' through 'wCGR3', registers with size 32 bits and type 'int'. d55425 4 a55428 4 - 'wCID', register with size of 32 bits and type 'int'. - 'wCon', register with size 32 bits and type 'int'. - 'wCSSF', register with size 32 bits and type 'int'. - 'wCASF', register with size 32 bit and type 'int'. d55438 1 a55438 1 The 'org.gnu.gdb.arm.vfp' feature is optional. If present, it should d55444 4 a55447 4 - 'd0' through 'd15'. The double-precision registers. They are 64 bits in size and have type 'ieee_double'. - 'fpscr', the floating-point status and control register. It has a size of 32 bits and a type of 'int'. d55451 4 a55454 4 - 'd0' through 'd31'. The double-precision registers. They are 64 bits in size and have type 'ieee_double'. - 'fpscr', the floating-point status and control register. It has a size of 32 bits and a type of 'int'. d55466 1 a55466 1 The 'org.gnu.gdb.arm.neon' feature is optional. It does not need to d55470 1 a55470 1 'org.gnu.gdb.arm.vfp' must also be present and include 32 d55479 1 a55479 1 The 'org.gnu.gdb.arm.m-profile-pacbti' feature is optional, and d55496 1 a55496 1 The 'org.gnu.gdb.arm.m-system' optional feature was introduced as a way d55501 4 a55504 4 - 'msp', the main stack pointer register. It is 32 bits in size with type 'data_ptr'. - 'psp', the process stack pointer register. It is 32 bits in size with type 'data_ptr'. d55507 2 a55508 2 sees this feature, it will attempt to track the values of 'msp' and 'psp' across frames. d55516 1 a55516 1 The 'org.gnu.gdb.arm.secext' optional feature was introduced so GDB d55522 8 a55529 8 - 'msp_ns', the main stack pointer register (non-secure state). It is 32 bits in size with type 'data_ptr'. - 'psp_ns', the process stack pointer register (non-secure state). It is 32 bits in size with type 'data_ptr'. - 'msp_s', the main stack pointer register (secure state). It is 32 bits in size with type 'data_ptr'. - 'psp_s', the process stack pointer register (secure state). It is 32 bits in size with type 'data_ptr'. d55541 1 a55541 1 The optional 'org.gnu.gdb.arm.tls' feature contains TLS registers. d55545 2 a55546 2 - 'tpidruro', the user read-only thread id register. It is 32 bits in size and has type 'data_ptr'. d55560 1 a55560 1 The 'org.gnu.gdb.i386.core' feature is required for i386/amd64 targets. d55563 6 a55568 6 - 'eax' through 'edi' plus 'eip' for i386 - 'rax' through 'r15' plus 'rip' for amd64 - 'eflags', 'cs', 'ss', 'ds', 'es', 'fs', 'gs' - 'st0' through 'st7' - 'fctrl', 'fstat', 'ftag', 'fiseg', 'fioff', 'foseg', 'fooff' and 'fop' d55572 1 a55572 1 The 'org.gnu.gdb.i386.sse' feature is optional. It should describe d55575 3 a55577 3 - 'xmm0' through 'xmm7' for i386 - 'xmm0' through 'xmm15' for amd64 - 'mxcsr' d55579 2 a55580 2 The 'org.gnu.gdb.i386.avx' feature is optional and requires the 'org.gnu.gdb.i386.sse' feature. It should describe the upper 128 bits d55583 2 a55584 2 - 'ymm0h' through 'ymm7h' for i386 - 'ymm0h' through 'ymm15h' for amd64 d55586 1 a55586 1 The 'org.gnu.gdb.i386.mpx' is an optional feature representing Intel d55590 2 a55591 2 - 'bnd0raw' through 'bnd3raw' for i386 and amd64. - 'bndcfgu' and 'bndstatus' for i386 and amd64. d55593 2 a55594 2 The 'org.gnu.gdb.i386.linux' feature is optional. It should describe a single register, 'orig_eax'. d55596 2 a55597 2 The 'org.gnu.gdb.i386.segments' feature is optional. It should describe two system registers: 'fs_base' and 'gs_base'. d55599 2 a55600 2 The 'org.gnu.gdb.i386.avx512' feature is optional and requires the 'org.gnu.gdb.i386.avx' feature. It should describe additional XMM d55603 1 a55603 1 - 'xmm16h' through 'xmm31h', only valid for amd64. d55607 1 a55607 1 - 'ymm16h' through 'ymm31h', only valid for amd64. d55611 2 a55612 2 - 'zmm0h' through 'zmm7h' for i386. - 'zmm0h' through 'zmm15h' for amd64. d55616 1 a55616 1 - 'zmm16h' through 'zmm31h', only valid for amd64. d55618 2 a55619 2 The 'org.gnu.gdb.i386.pkeys' feature is optional. It should describe a single register, 'pkru'. It is a 32-bit register valid for i386 and d55628 4 a55631 4 The 'org.gnu.gdb.loongarch.base' feature is required for LoongArch targets. It should contain the registers 'r0' through 'r31', 'pc', and 'badv'. Either the architectural names ('r0', 'r1', etc) can be used, or the ABI names ('zero', 'ra', etc). d55633 2 a55634 2 The 'org.gnu.gdb.loongarch.fpu' feature is optional. If present, it should contain registers 'f0' through 'f31', 'fcc', and 'fcsr'. d55642 4 a55645 4 The 'org.gnu.gdb.microblaze.core' feature is required for MicroBlaze targets. It should contain registers 'r0' through 'r31', 'rpc', 'rmsr', 'rear', 'resr', 'rfsr', 'rbtr', 'rpvr', 'rpvr1' through 'rpvr11', 'redr', 'rpid', 'rzpr', 'rtlbx', 'rtlbsx', 'rtlblo', and 'rtlbhi'. d55647 2 a55648 2 The 'org.gnu.gdb.microblaze.stack-protect' feature is optional. If present, it should contain registers 'rshr' and 'rslr' d55656 2 a55657 2 The 'org.gnu.gdb.mips.cpu' feature is required for MIPS targets. It should contain registers 'r0' through 'r31', 'lo', 'hi', and 'pc'. They d55660 2 a55661 2 The 'org.gnu.gdb.mips.cp0' feature is also required. It should contain at least the 'status', 'badvaddr', and 'cause' registers. They d55664 1 a55664 1 The 'org.gnu.gdb.mips.fpu' feature is currently required, though it d55666 1 a55666 1 'f0' through 'f31', 'fcsr', and 'fir'. They may be 32-bit or 64-bit d55669 3 a55671 3 The 'org.gnu.gdb.mips.dsp' feature is optional. It should contain registers 'hi1' through 'hi3', 'lo1' through 'lo3', and 'dspctl'. The 'dspctl' register should be 32-bit and the rest may be 32-bit or 64-bit d55674 2 a55675 2 The 'org.gnu.gdb.mips.linux' feature is optional. It should contain a single register, 'restart', which is used by the Linux kernel to d55684 3 a55686 3 ''org.gnu.gdb.m68k.core'' ''org.gnu.gdb.coldfire.core'' ''org.gnu.gdb.fido.core'' d55689 2 a55690 2 is present should contain registers 'd0' through 'd7', 'a0' through 'a5', 'fp', 'sp', 'ps' and 'pc'. d55692 1 a55692 1 ''org.gnu.gdb.coldfire.fp'' d55694 1 a55694 1 'fp0' through 'fp7', 'fpcontrol', 'fpstatus' and 'fpiaddr'. d55697 1 a55697 1 'coldfire', it is used to describe any floating point registers. d55699 1 a55699 1 example, if the primary feature is reported as 'coldfire', then d55708 7 a55714 7 The 'org.gnu.gdb.nds32.core' feature is required for NDS32 targets. It should contain at least registers 'r0' through 'r10', 'r15', 'fp', 'gp', 'lp', 'sp', and 'pc'. The 'org.gnu.gdb.nds32.fpu' feature is optional. If present, it should contain 64-bit double-precision floating-point registers 'fd0' through _fdN_, which should be 'fd3', 'fd7', 'fd15', or 'fd31' based on d55731 4 a55734 4 The 'org.gnu.gdb.nios2.cpu' feature is required for Nios II targets. It should contain the 32 core registers ('zero', 'at', 'r2' through 'r23', 'et' through 'ra'), 'pc', and the 16 control registers ('status' through 'mpuacc'). d55742 3 a55744 3 The 'org.gnu.gdb.or1k.group0' feature is required for OpenRISC 1000 targets. It should contain the 32 general purpose registers ('r0' through 'r31'), 'ppc', 'npc' and 'sr'. d55752 31 a55782 31 The 'org.gnu.gdb.power.core' feature is required for PowerPC targets. It should contain registers 'r0' through 'r31', 'pc', 'msr', 'cr', 'lr', 'ctr', and 'xer'. They may be 32-bit or 64-bit depending on the target. The 'org.gnu.gdb.power.fpu' feature is optional. It should contain registers 'f0' through 'f31' and 'fpscr'. The 'org.gnu.gdb.power.altivec' feature is optional. It should contain registers 'vr0' through 'vr31', 'vscr', and 'vrsave'. GDB will define pseudo-registers 'v0' through 'v31' as aliases for the corresponding 'vrX' registers. The 'org.gnu.gdb.power.vsx' feature is optional. It should contain registers 'vs0h' through 'vs31h'. GDB will combine these registers with the floating point registers ('f0' through 'f31') and the altivec registers ('vr0' through 'vr31') to present the 128-bit wide registers 'vs0' through 'vs63', the set of vector-scalar registers for POWER7. Therefore, this feature requires both 'org.gnu.gdb.power.fpu' and 'org.gnu.gdb.power.altivec'. The 'org.gnu.gdb.power.spe' feature is optional. It should contain registers 'ev0h' through 'ev31h', 'acc', and 'spefscr'. SPE targets should provide 32-bit registers in 'org.gnu.gdb.power.core' and provide the upper halves in 'ev0h' through 'ev31h'. GDB will combine these to present registers 'ev0' through 'ev31' to the user. The 'org.gnu.gdb.power.ppr' feature is optional. It should contain the 64-bit register 'ppr'. The 'org.gnu.gdb.power.dscr' feature is optional. It should contain the 64-bit register 'dscr'. d55784 2 a55785 2 The 'org.gnu.gdb.power.tar' feature is optional. It should contain the 64-bit register 'tar'. d55787 2 a55788 2 The 'org.gnu.gdb.power.ebb' feature is optional. It should contain registers 'bescr', 'ebbhr' and 'ebbrr', all 64-bit wide. d55790 2 a55791 2 The 'org.gnu.gdb.power.linux.pmu' feature is optional. It should contain registers 'mmcr0', 'mmcr2', 'siar', 'sdar' and 'sier', all d55795 2 a55796 2 The 'org.gnu.gdb.power.htm.spr' feature is optional. It should contain registers 'tfhar', 'texasr' and 'tfiar', all 64-bit wide. d55798 3 a55800 3 The 'org.gnu.gdb.power.htm.core' feature is optional. It should contain the checkpointed general-purpose registers 'cr0' through 'cr31', as well as the checkpointed registers 'clr' and 'cctr'. These registers d55802 1 a55802 1 also contain the checkpointed registers 'ccr' and 'cxer', which should d55805 16 a55820 16 The 'org.gnu.gdb.power.htm.fpu' feature is optional. It should contain the checkpointed 64-bit floating-point registers 'cf0' through 'cf31', as well as the checkpointed 64-bit register 'cfpscr'. The 'org.gnu.gdb.power.htm.altivec' feature is optional. It should contain the checkpointed altivec registers 'cvr0' through 'cvr31', all 128-bit wide. It should also contain the checkpointed registers 'cvscr' and 'cvrsave', both 32-bit wide. The 'org.gnu.gdb.power.htm.vsx' feature is optional. It should contain registers 'cvs0h' through 'cvs31h'. GDB will combine these registers with the checkpointed floating point registers ('cf0' through 'cf31') and the checkpointed altivec registers ('cvr0' through 'cvr31') to present the 128-bit wide checkpointed vector-scalar registers 'cvs0' through 'cvs63'. Therefore, this feature requires both 'org.gnu.gdb.power.htm.altivec' and 'org.gnu.gdb.power.htm.fpu'. d55822 2 a55823 2 The 'org.gnu.gdb.power.htm.ppr' feature is optional. It should contain the 64-bit checkpointed register 'cppr'. d55825 2 a55826 2 The 'org.gnu.gdb.power.htm.dscr' feature is optional. It should contain the 64-bit checkpointed register 'cdscr'. d55828 2 a55829 2 The 'org.gnu.gdb.power.htm.tar' feature is optional. It should contain the 64-bit checkpointed register 'ctar'. d55837 8 a55844 8 The 'org.gnu.gdb.riscv.cpu' feature is required for RISC-V targets. It should contain the registers 'x0' through 'x31', and 'pc'. Either the architectural names ('x0', 'x1', etc) can be used, or the ABI names ('zero', 'ra', etc). The 'org.gnu.gdb.riscv.fpu' feature is optional. If present, it should contain registers 'f0' through 'f31', 'fflags', 'frm', and 'fcsr'. As with the cpu feature, either the architectural register d55847 1 a55847 1 The 'org.gnu.gdb.riscv.virtual' feature is optional. If present, it d55852 1 a55852 1 register expected in this set is the one byte 'priv' register that d55855 1 a55855 1 The 'org.gnu.gdb.riscv.csr' feature is optional. If present, it d55858 2 a55859 2 overlap between this feature and the fpu feature; the 'fflags', 'frm', and 'fcsr' registers could be in either feature. The expectation is d55865 2 a55866 2 The 'org.gnu.gdb.riscv.vector' feature is optional. If present, it should contain registers 'v0' through 'v31', all of which must be the d55875 3 a55877 3 The 'org.gnu.gdb.rx.core' feature is required for RX targets. It should contain the registers 'r0' through 'r15', 'usp', 'isp', 'psw', 'pc', 'intb', 'bpsw', 'bpc', 'fintv', 'fpsw', and 'acc'. d55885 1 a55885 1 The 'org.gnu.gdb.s390.core' feature is required for S/390 and System z d55887 2 a55888 2 particular, System z targets should provide the 64-bit registers 'pswm', 'pswa', and 'r0' through 'r15'. S/390 targets should provide the 32-bit d55890 13 a55902 13 addressing mode should provide 32-bit versions of 'pswm' and 'pswa', as well as the general register's upper halves 'r0h' through 'r15h', and their lower halves 'r0l' through 'r15l'. The 'org.gnu.gdb.s390.fpr' feature is required. It should contain the 64-bit registers 'f0' through 'f15', and 'fpc'. The 'org.gnu.gdb.s390.acr' feature is required. It should contain the 32-bit registers 'acr0' through 'acr15'. The 'org.gnu.gdb.s390.linux' feature is optional. It should contain the register 'orig_r2', which is 64-bit wide on System z targets and 32-bit otherwise. In addition, the feature may contain the 'last_break' d55904 1 a55904 1 'system_call' register, which is always 32-bit wide. d55906 18 a55923 18 The 'org.gnu.gdb.s390.tdb' feature is optional. It should contain the 64-bit registers 'tdb0', 'tac', 'tct', 'atia', and 'tr0' through 'tr15'. The 'org.gnu.gdb.s390.vx' feature is optional. It should contain 64-bit wide registers 'v0l' through 'v15l', which will be combined by GDB with the floating point registers 'f0' through 'f15' to present the 128-bit wide vector registers 'v0' through 'v15'. In addition, this feature should contain the 128-bit wide vector registers 'v16' through 'v31'. The 'org.gnu.gdb.s390.gs' feature is optional. It should contain the 64-bit wide guarded-storage-control registers 'gsd', 'gssm', and 'gsepla'. The 'org.gnu.gdb.s390.gsbc' feature is optional. It should contain the 64-bit wide guarded-storage broadcast control registers 'bc_gsd', 'bc_gssm', and 'bc_gsepla'. d55931 1 a55931 1 The 'org.gnu.gdb.sparc.cpu' feature is required for sparc32/sparc64 d55934 4 a55937 4 - 'g0' through 'g7' - 'o0' through 'o7' - 'l0' through 'l7' - 'i0' through 'i7' d55941 1 a55941 1 Also the 'org.gnu.gdb.sparc.fpu' feature is required for d55944 2 a55945 2 - 'f0' through 'f31' - 'f32' through 'f62' for sparc64 d55947 1 a55947 1 The 'org.gnu.gdb.sparc.cp0' feature is required for sparc32/sparc64 d55950 2 a55951 2 - 'y', 'psr', 'wim', 'tbr', 'pc', 'npc', 'fsr', and 'csr' for sparc32 - 'pc', 'npc', 'state', 'fsr', 'fprs', and 'y' for sparc64 d55959 3 a55961 3 The 'org.gnu.gdb.tic6x.core' feature is required for TMS320C6x targets. It should contain registers 'A0' through 'A15', registers 'B0' through 'B15', 'CSR' and 'PC'. d55963 2 a55964 2 The 'org.gnu.gdb.tic6x.gp' feature is optional. It should contain registers 'A16' through 'A31' and 'B16' through 'B31'. d55966 2 a55967 2 The 'org.gnu.gdb.tic6x.c6xp' feature is optional. It should contain registers 'TSR', 'ILC' and 'RILC'. d55983 2 a55984 2 remote protocol, using 'qXfer' requests (*note qXfer osdata read::). The object name in the request should be 'osdata', and the ANNEX d55997 3 a55999 3 When requesting the process list, the ANNEX field in the 'qXfer' request should be 'processes'. The returned data is an XML document. The formal syntax of this document is defined in 'gdb/features/osdata.dtd'. d56014 4 a56017 4 Each item should include a column whose name is 'pid'. The value of that column should identify the process on the target. The 'user' and 'command' columns are optional, and will be displayed by GDB. The 'cores' column, if present, should contain a comma-separated list of d56030 2 a56031 2 The header has the form '\x7fTRACE0\n'. The first byte is '0x7f' so as to indicate that the file contains binary data, while the '0' is a d56035 1 a56035 1 separated by newline characters ('0xa'). The lines may include a d56041 1 a56041 1 'R SIZE' d56043 1 a56043 1 the size of a 'g' packet payload in the remote protocol. SIZE is d56047 2 a56048 2 'status STATUS' Trace status. STATUS has the same format as a 'qTStatus' remote d56052 1 a56052 1 'tp PAYLOAD' d56054 1 a56054 1 'qTfP'/'qTsP' remote packet reply payload. A single tracepoint may d56058 1 a56058 1 'tsv PAYLOAD' d56060 1 a56060 1 as 'qTfV'/'qTsV' remote packet reply payload. A single variable d56064 1 a56064 1 'tdesc PAYLOAD' d56068 2 a56069 2 'qXfer' 'features' payload, and corresponds to the main 'target.xml' file. Includes are not allowed. d56079 1 a56079 1 'R BYTES' d56081 1 a56081 1 'g' packet in the remote protocol. Note that these are the actual d56084 1 a56084 1 'M ADDRESS LENGTH BYTES...' d56089 1 a56089 1 'V NUMBER VALUE' d56099 1 a56099 1 Appendix J '.gdb_index' section format d56102 2 a56103 2 This section documents the index section that is created by 'save gdb-index' (*note Index Files::). The index section is DWARF-specific; d56106 1 a56106 1 The mapped index file format is designed to be directly 'mmap'able on d56108 1 a56108 1 little-endian 32-bit integer value, called an 'offset_type'. Big endian d56115 1 a56115 1 1. The file header. This is a sequence of values, of 'offset_type' d56124 2 a56125 2 ('DW_TAG_type_unit') refer to the type unit's symbol table and not the compilation unit ('DW_TAG_comp_unit') using the type. d56130 1 a56130 1 'set use-deprecated-index-sections on'. GDB has a workaround d56150 1 a56150 1 the offset of a CU in the '.debug_info' section. The second d56169 1 a56169 1 'DW_AT_high_pc', the value is one byte beyond the end. d56171 1 a56171 1 3. The CU index. This is an 'offset_type' value. d56176 1 a56176 1 Each slot in the hash table consists of a pair of 'offset_type' d56187 1 a56187 1 initial value of 'r = 0', each (unsigned) character 'c' in the d56192 1 a56192 1 The formula is 'r = r * 67 + c - 113'. d56195 1 a56195 1 The formula is 'r = r * 67 + tolower (c) - 113'. d56197 1 a56197 1 The terminating '\0' is not incorporated into the hash. d56199 2 a56200 2 The step size used in the hash table is computed via '((hash * 17) & (size - 1)) | 1', where 'hash' is the hash value, and 'size' is d56213 2 a56214 2 An 'offset_type' value indicating the language of the main function as a 'DW_LANG_' constant. This value will be zero if d56218 1 a56218 1 An 'offset_type' value indicating the offset of the main d56226 1 a56226 1 A CU vector in the constant pool is a sequence of 'offset_type' d56235 1 a56235 1 Attributes were added to CU index values in '.gdb_index' version 7. d56251 1 a56251 1 zero the full 'offset_type' value is backwards compatible with d56269 1 a56269 1 'dwarf2read.c' in GDB sources. d56322 1 a56322 1 'debuginfod' is an HTTP server for distributing ELF, DWARF and source d56325 1 a56325 1 With the 'debuginfod' client library, 'libdebuginfod', GDB can query d56329 3 a56331 3 For instructions on building GDB with 'libdebuginfod', *note -with-debuginfod: Configure Options. 'debuginfod' is packaged with 'elfutils', starting with version 0.178. See d56333 1 a56333 1 regarding 'debuginfod'. d56345 1 a56345 1 GDB provides the following commands for configuring 'debuginfod'. d56347 3 a56349 3 'set debuginfod enabled' 'set debuginfod enabled on' GDB may query 'debuginfod' servers for missing debug info and d56351 3 a56353 3 such as '.gdb_index' to help reduce the total amount of data downloaded from 'debuginfod' servers; this can be controlled by 'maint set debuginfod download-sections' (*note maint set d56356 19 a56374 19 'set debuginfod enabled off' GDB will not attempt to query 'debuginfod' servers when missing debug info or source files. By default, 'debuginfod enabled' is set to 'off' for non-interactive sessions. 'set debuginfod enabled ask' GDB will prompt the user to enable or disable 'debuginfod' before attempting to perform the next query. By default, 'debuginfod enabled' is set to 'ask' for interactive sessions. 'show debuginfod enabled' Display whether 'debuginfod enabled' is set to 'on', 'off' or 'ask'. 'set debuginfod urls' 'set debuginfod urls URLS' Set the space-separated list of URLs that 'debuginfod' will attempt to query. Only 'http://', 'https://' and 'file://' protocols should be used. The default value of 'debuginfod urls' is copied d56377 2 a56378 2 'show debuginfod urls' Display the list of URLs that 'debuginfod' will attempt to query. d56380 4 a56383 4 'set debuginfod verbose' 'set debuginfod verbose N' Enable or disable 'debuginfod'-related output. Use a non-zero value to enable and '0' to disable. 'debuginfod' output is shown d56386 1 a56386 1 'show debuginfod verbose' d56418 1 a56418 1 * Start your program, specifying anything that might affect its d56421 1 a56421 1 * Make your program stop on specified conditions. d56423 1 a56423 1 * Examine what has happened, when your program has stopped. d56425 1 a56425 1 * Change things in your program, so you can experiment with d56431 1 a56431 1 GDB is invoked with the shell command 'gdb'. Once started, it reads d56433 2 a56434 2 command 'quit' or 'exit'. You can get online help from GDB itself by using the command 'help'. d56436 1 a56436 1 You can run 'gdb' with no arguments or options; but the most usual d56448 1 a56448 1 option '-p', if you want to debug a running process: d56453 1 a56453 1 would attach GDB to process '1234'. With option '-p' you can omit the d56458 1 a56458 1 'break [FILE:][FUNCTION|LINE]' d56461 1 a56461 1 'run [ARGLIST]' d56464 1 a56464 1 'bt' d56467 1 a56467 1 'print EXPR' d56470 1 a56470 1 'c' d56474 1 a56474 1 'next' d56478 1 a56478 1 'edit [FILE:]FUNCTION' d56481 1 a56481 1 'list [FILE:]FUNCTION' d56485 1 a56485 1 'step' d56489 1 a56489 1 'help [NAME]' d56493 2 a56494 2 'quit' 'exit' d56499 2 a56500 2 associated option flag is equivalent to a '--se' option, and the second, if any, is equivalent to a '-c' option if it's the name of a file. Many d56505 2 a56506 2 The abbreviated forms are shown here with '-' and long forms are shown with '--' to reflect how they are shown in '--help'. However, GDB d56509 8 a56516 8 '--option=VALUE' '--option VALUE' '-option=VALUE' '-option VALUE' '--o=VALUE' '--o VALUE' '-o=VALUE' '-o VALUE' d56519 1 a56519 1 sequential order. The order makes a difference when the '-x' option is d56522 2 a56523 2 '--help' '-h' d56526 2 a56527 2 '--symbols=FILE' '-s FILE' d56530 1 a56530 1 '--write' d56533 2 a56534 2 '--exec=FILE' '-e FILE' d56538 1 a56538 1 '--se=FILE' d56541 2 a56542 2 '--core=FILE' '-c FILE' d56545 2 a56546 2 '--command=FILE' '-x FILE' d56549 2 a56550 2 '--eval-command=COMMAND' '-ex COMMAND' d56553 2 a56554 2 '--init-eval-command=COMMAND' '-iex' d56557 2 a56558 2 '--directory=DIRECTORY' '-d DIRECTORY' d56561 7 a56567 7 '--nh' Do not execute commands from '~/.config/gdb/gdbinit', '~/.gdbinit', '~/.config/gdb/gdbearlyinit', or '~/.gdbearlyinit' '--nx' '-n' Do not execute commands from any '.gdbinit' or '.gdbearlyinit' d56570 3 a56572 3 '--quiet' '--silent' '-q' d56576 3 a56578 3 '--batch' Run in batch mode. Exit with status '0' after processing all the command files specified with '-x' (and '.gdbinit', if not d56591 2 a56592 2 '--batch-silent' Run in batch mode, just like '--batch', but totally silent. All d56594 1 a56594 1 quieter than '--silent' and would be useless for an interactive d56597 2 a56598 2 This is particularly useful when using targets that give 'Loading section' messages, for example. d56601 1 a56601 1 writing directly to 'stdout', will also be made silent. d56603 1 a56603 1 '--args PROG [ARGLIST]' d56610 1 a56610 1 It would start GDB with '-q', not printing the introductory d56618 1 a56618 1 '--pid=PID' d56621 1 a56621 1 '--tui' d56624 1 a56624 1 '--readnow' d56627 1 a56627 1 '--readnever' d56630 1 a56630 1 '--return-child-result' d56633 1 a56633 1 '--configuration' d56636 1 a56636 1 '--version' d56639 1 a56639 1 '--cd=DIRECTORY' d56643 2 a56644 2 '--data-directory=DIRECTORY' '-D' d56648 2 a56649 2 '--fullname' '-f' d56654 1 a56654 1 looks like two '\032' characters, followed by the file name, line d56656 1 a56656 1 The Emacs-to-GDB interface program uses the two '\032' characters d56659 1 a56659 1 '-b BAUDRATE' d56663 1 a56663 1 '-l TIMEOUT' d56666 1 a56666 1 '--tty=DEVICE' d56681 1 a56681 1 'gdbserver' is a program that allows you to run GDB on a different d56689 1 a56689 1 as 'gdbserver' doesn't care about symbols. All symbol handling is taken d56693 1 a56693 1 'gdbserver' program. You must tell it (a) how to communicate with GDB, d56703 2 a56704 2 This tells 'gdbserver' to debug emacs with an argument of foo.txt, and to communicate with GDB via '/dev/com1'. 'gdbserver' now waits d56712 3 a56714 3 we are going to communicate with the 'host' GDB via TCP. The 'host:2345' argument means that we are expecting to see a TCP connection from 'host' to local TCP port 2345. (Currently, the 'host' part is ignored.) You d56717 1 a56717 1 same port number must be used in the host GDBs 'target remote' command, d56719 1 a56719 1 that conflicts with another service, 'gdbserver' will print an error d56722 2 a56723 2 'gdbserver' can also attach to running programs. This is accomplished via the '--attach' argument. The syntax is: d56728 1 a56728 1 necessary to point 'gdbserver' at a binary for the running process. d56730 3 a56732 3 To start 'gdbserver' without supplying an initial command to run or process ID to attach, use the '--multi' command line option. In such case you should connect using 'target extended-remote' to start the d56743 6 a56748 6 may need to use the '--baud' option if the serial line is running at anything except 9600 baud.) That is 'gdb TARGET-PROG', or 'gdb --baud BAUD TARGET-PROG'. After that, the only new command you need to know about is 'target remote' (or 'target extended-remote'). Its argument is either a device name (usually a serial device, like '/dev/ttyb'), or a 'HOST:PORT' descriptor. For example: d56752 1 a56752 1 communicates with the server via serial line '/dev/ttyb', and: d56757 2 a56758 2 where you previously started up 'gdbserver' with the same port number. Note that for TCP connections, you must start up 'gdbserver' prior to d56762 1 a56762 1 'gdbserver' can also debug multiple inferiors at once, described in d56764 1 a56764 1 'extended-remote' GDB command variant: d56768 1 a56768 1 The 'gdbserver' option '--multi' may or may not be used in such case. d56770 1 a56770 1 There are three different modes for invoking 'gdbserver': d56772 1 a56772 1 * Debug a specific program specified by its program name: d56778 2 a56779 2 number (':1234'), or '-' or 'stdio' to use stdin/stdout of 'gdbserver'. Specify the name of the program to debug in PROG. d56782 1 a56782 1 'gdbserver' will exit. d56784 1 a56784 1 * Debug a specific program by specifying the process ID of a running d56792 1 a56792 1 connection, and 'gdbserver' will exit. d56794 1 a56794 1 * Multi-process mode - debug more than one program/process: d56798 1 a56798 1 In this mode, GDB can instruct 'gdbserver' which command(s) to run. d56805 1 a56805 1 '--help' d56808 2 a56809 2 '--version' This option causes 'gdbserver' to print its version number and d56812 2 a56813 2 '--attach' 'gdbserver' will attach to a running program. The syntax is: d56818 1 a56818 1 necessary to point 'gdbserver' at a binary for the running process. d56820 2 a56821 2 '--multi' To start 'gdbserver' without supplying an initial command to run or d56823 1 a56823 1 connect using 'target extended-remote' and start the program you d56828 3 a56830 3 '--debug[=option1,option2,...]' Instruct 'gdbserver' to display extra status information about the debugging process. This option is intended for 'gdbserver' d56834 2 a56835 2 be enabled. The list of possible options is 'all', 'threads', 'event-loop', 'remote'. The special option 'all' enables all d56837 1 a56837 1 option can be prefixed with the '-' character to disable output for d56842 8 a56849 8 to turn on debug output for all components except 'event-loop'. If no options are passed to '--debug' then this is treated as equivalent to '--debug=threads'. This could change in future releases of 'gdbserver'. '--debug-file=FILENAME' Instruct 'gdbserver' to send any debug output to the given FILENAME. This option is intended for 'gdbserver' development and d56852 2 a56853 2 '--debug-format=option1[,option2,...]' Instruct 'gdbserver' to include extra information in each line of d56857 1 a56857 1 '--wrapper' d56860 1 a56860 1 command-line arguments to pass to the wrapper, then '--' indicating d56863 2 a56864 2 '--once' By default, 'gdbserver' keeps the listening TCP port open, so that d56866 1 a56866 1 'gdbserver' with the '--once' option, it will stop listening for d56879 2 a56880 2 PID1, PID2, etc. A core file produced by 'gcore' is equivalent to one produced by the kernel when the process crashes (and when 'ulimit -c' d56882 1 a56882 1 after a crash, after 'gcore' finishes its job the program remains d56885 1 a56885 1 '-a' d56888 2 a56889 2 'use-coredump-filter' (*note set use-coredump-filter::) and enable 'dump-excluded-mappings' (*note set dump-excluded-mappings::). d56891 1 a56891 1 '-o PREFIX' d56894 2 a56895 2 composed as 'PREFIX.PID', where PID is the process ID of the running program being analyzed by 'gcore'. If not specified, d56918 1 a56918 1 '(not enabled with --with-system-gdbinit during compilation)' d56920 2 a56921 2 specified GDB option '-nx' or '-n'. See more in '(not enabled with --with-system-gdbinit-dir during compilation)' d56923 2 a56924 2 are executed on startup unless user specified GDB option '-nx' or '-n', as long as they have a recognized file extension. See more d56927 1 a56927 1 '~/.config/gdb/gdbinit or ~/.gdbinit' d56929 1 a56929 1 options '-nx', '-n' or '-nh'. d56931 1 a56931 1 '.gdbinit' d56933 1 a56933 1 enabled with GDB security command 'set auto-load local-gdbinit'. d56951 2 a56952 2 'readelf -S filename': the index is stored in a section named '.gdb_index'. The index file can only be produced on systems which use d56954 1 a56954 1 '.debug_*'). d56956 1 a56956 1 'gdb-add-index' uses GDB and 'objdump' found in the 'PATH' d56958 1 a56958 1 programs, you can specify them through the 'GDB' and 'OBJDUMP' d56971 1 a56971 1 Copyright (C) 2007 Free Software Foundation, Inc. d57658 1 a57658 1 This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'. d57660 1 a57660 1 under certain conditions; type 'show c' for details. d57662 1 a57662 1 The hypothetical commands 'show w' and 'show c' should show the d57687 1 a57687 1 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. d57696 1 a57696 1 functional and useful document "free" in the sense of freedom: to d58170 2 a58171 10 * ! packet: Packets. (line 49) * "No symbol "foo" in current context": Variables. (line 122) * # in Modula-2: GDB/M2. (line 18) * $: Value History. (line 13) * $$: Value History. (line 13) * $_ and info breakpoints: Set Breaks. (line 244) * $_ and info line: Machine Code. (line 35) * $_, $__, and value history: Memory. (line 136) * &, background execution of commands: Background Execution. (line 16) a58182 1 * --debug, gdbserver option: Server. (line 146) d58185 1 d58243 2 a58252 2 * .gdbinit: Initialization Files. (line 107) d58256 2 d58264 2 d58268 3 d58290 5 a58294 4 * ? packet: Packets. (line 58) * _NSPrintForDebugger, and printing Objective-C objects: The Print Command with Objective-C. (line 11) * {TYPE}: Expressions. (line 41) d58451 1 a58451 1 (line 1051) d58565 1 a58566 1 * colon-colon, context for variables/functions: Variables. (line 44) d58648 1 a58648 1 (line 147) d58746 1 a58746 1 (line 467) d58758 1 a58758 1 * display GDB copyright: Help. (line 175) d58837 1 a58837 1 (line 613) d58871 1 a58871 1 (line 656) d58951 1 a58951 1 * GDB version number: Help. (line 165) d59233 1 a59233 1 (line 467) d59325 1 a59325 1 (line 981) d59431 1 a59431 1 (line 887) d59493 1 a59493 1 (line 192) a59535 1 * protocol, GDB remote serial: Overview. (line 14) d59538 1 d59581 1 a59581 1 (line 1453) d59619 1 a59619 1 (line 613) d59621 1 a59621 1 (line 634) d59625 1 a59625 1 (line 645) d59631 1 a59631 1 (line 656) d59633 1 a59633 1 (line 1119) d59649 1 a59649 1 (line 1162) d59668 1 a59668 1 (line 1453) d59673 1 a59673 1 (line 1199) d59683 1 a59683 1 * raw printing: Output Formats. (line 78) d59685 2 a59686 1 (line 1199) a59687 1 * read-only sections: Files. (line 290) d59814 1 a59814 1 (line 467) d59818 1 a59818 1 (line 634) d59954 1 a59954 1 (line 1029) d59976 1 a59976 1 (line 1046) d59995 1 a59995 1 (line 656) d60012 1 a60012 1 (line 1119) a60031 1 * system, file-i/o system call: system. (line 6) d60036 1 d60099 1 a60099 1 (line 1162) d60272 1 a60272 1 (line 1421) d60323 1 a60323 59 * !: Shell Commands. (line 10) * # (a comment): Command Syntax. (line 37) * $bpnum, convenience variable: Set Breaks. (line 6) * $cdir, convenience variable: Source Path. (line 40) * $cwd, convenience variable: Source Path. (line 40) * $tpnum: Create and Delete Tracepoints. (line 124) * $tracepoint: Tracepoint Variables. (line 10) * $trace_file: Tracepoint Variables. (line 16) * $trace_frame: Tracepoint Variables. (line 6) * $trace_func: Tracepoint Variables. (line 19) * $trace_line: Tracepoint Variables. (line 13) * $_, convenience variable: Convenience Vars. (line 65) * $_ada_exception, convenience variable: Set Catchpoints. (line 82) * $_any_caller_is, convenience function: Convenience Funs. (line 229) * $_any_caller_matches, convenience function: Convenience Funs. (line 241) * $_as_string, convenience function: Convenience Funs. (line 253) * $_caller_is, convenience function: Convenience Funs. (line 199) * $_caller_matches, convenience function: Convenience Funs. (line 222) * $_cimag, convenience function: Convenience Funs. (line 267) * $_creal, convenience function: Convenience Funs. (line 267) * $_exception, convenience variable: Set Catchpoints. (line 21) * $_exitcode, convenience variable: Convenience Vars. (line 80) * $_exitsignal, convenience variable: Convenience Vars. (line 85) * $_gdb_maint_setting, convenience function: Convenience Funs. (line 128) * $_gdb_maint_setting_str, convenience function: Convenience Funs. (line 124) * $_gdb_major, convenience variable: Convenience Vars. (line 183) * $_gdb_minor, convenience variable: Convenience Vars. (line 183) * $_gdb_setting, convenience function: Convenience Funs. (line 75) * $_gdb_setting_str, convenience function: Convenience Funs. (line 62) * $_gthread, convenience variable: Threads. (line 98) * $_hit_bpnum, convenience variable: Set Breaks. (line 24) * $_hit_locno, convenience variable: Set Breaks. (line 24) * $_inferior, convenience variable: Inferiors Connections and Programs. (line 107) * $_inferior_thread_count, convenience variable: Threads. (line 98) * $_isvoid, convenience function: Convenience Funs. (line 14) * $_memeq, convenience function: Convenience Funs. (line 183) * $_probe_arg, convenience variable: Static Probe Points. (line 77) * $_regex, convenience function: Convenience Funs. (line 187) * $_sdata, collect: Tracepoint Actions. (line 86) * $_sdata, inspect, convenience variable: Convenience Vars. (line 147) * $_shell, convenience function: Convenience Funs. (line 132) * $_shell_exitcode, convenience variable: Convenience Vars. (line 192) * $_shell_exitsignal, convenience variable: Convenience Vars. (line 192) * $_siginfo, convenience variable: Convenience Vars. (line 153) * $_streq, convenience function: Convenience Funs. (line 192) * $_strlen, convenience function: Convenience Funs. (line 196) * $_thread, convenience variable: Threads. (line 98) * $_tlb, convenience variable: Convenience Vars. (line 159) * $__, convenience variable: Convenience Vars. (line 74) d60557 13 d60588 55 a60642 10 * @@, referencing memory as an array: Arrays. (line 6) * ^connected: GDB/MI Result Records. (line 21) * ^done: GDB/MI Result Records. (line 9) * ^error: GDB/MI Result Records. (line 24) * ^exit: GDB/MI Result Records. (line 35) * ^running: GDB/MI Result Records. d60644 2 a60645 2 * __init__ on TypePrinter: gdb.types. (line 82) * |: Shell Commands. (line 29) d60658 1 a60658 1 (line 120) d60734 2 a60737 2 * Architecture.register_groups: Architectures In Python. (line 67) d60774 1 a60783 1 * block?: Blocks In Guile. (line 55) d60817 1 a60819 1 * break-range: PowerPC Embedded. (line 41) d60856 6 a60901 6 * Breakpoint.__init__: Breakpoints In Python. (line 16) * Breakpoint.__init__ <1>: Breakpoints In Python. (line 49) * breakpoint?: Breakpoints In Guile. (line 118) d60923 1 a60923 1 (line 494) d60962 2 a60965 2 * clear-display (M-C-l): Commands For Moving. (line 40) * clear-screen (C-l): Commands For Moving. (line 45) d60968 1 a60968 1 (line 136) a60974 11 * Command.complete: CLI Commands In Python. (line 72) * Command.dont_repeat: CLI Commands In Python. (line 42) * Command.invoke: CLI Commands In Python. (line 50) * Command.__init__: CLI Commands In Python. (line 10) * command?: Commands In Guile. (line 63) * commands: Break Commands. (line 11) * commands annotation: Prompting. (line 27) d61013 11 d61063 1 a61063 1 * ConnectionEvent.connection: Events In Python. (line 280) d61115 1 a61115 1 (line 171) d61135 2 a61150 2 * DisassembleInfo.__init__: Disassembly In Python. (line 46) d61156 1 a61156 1 (line 311) d61158 3 a61160 1 (line 259) d61162 1 a61162 1 (line 210) d61164 1 a61164 1 (line 227) d61166 1 a61166 3 (line 214) * DisassemblerResult.__init__: Disassembly In Python. (line 186) d61168 1 a61168 1 (line 275) d61251 2 a61252 2 * ExecutableChangedEvent.progspace: Events In Python. (line 293) * ExecutableChangedEvent.reload: Events In Python. (line 298) d61286 2 a61291 2 * FinishBreakpoint.__init__: Finish Breakpoints in Python. (line 14) d61293 1 a61295 1 * flush_i_cache: Bootstrapping. (line 59) a61308 1 * frame, selecting: Selection. (line 11) d61323 2 a61341 1 * frame?: Frames In Guile. (line 22) d61356 1 a61356 1 * FreeProgspaceEvent.progspace: Events In Python. (line 334) d61362 1 a61363 1 * Function.__init__: Functions In Python. (line 10) d61366 2 d61371 8 d61454 1 a61454 1 (line 281) d61456 1 a61456 1 (line 244) d61460 1 a61460 1 (line 265) d61462 1 a61462 1 (line 377) d61464 1 a61464 1 (line 389) d61466 1 a61466 1 (line 355) d61468 1 a61468 1 (line 435) d61470 1 a61470 1 (line 406) d61472 1 a61472 1 (line 329) d61474 1 a61474 1 (line 370) d61476 1 a61476 1 (line 337) d61478 1 a61478 1 (line 416) d61480 1 a61480 1 (line 323) d61490 1 a61491 1 * gdb.frame_stop_reason_string: Frames In Python. (line 29) a61523 3 * gdb.Parameter: Parameters In Python. (line 6) * gdb.parameter: Basic Python. (line 85) d61548 3 d61658 1 a61658 1 (line 205) d61660 1 a61660 1 (line 221) d61662 1 a61662 1 (line 202) d61664 1 a61664 1 (line 208) d61679 1 a61679 9 * gdb:error: Guile Exception Handling. (line 69) * gdb:invalid-object: Guile Exception Handling. (line 72) * gdb:memory-error: Guile Exception Handling. (line 80) * gdb:pp-type-error: Guile Exception Handling. (line 84) * GdbExitingEvent.exit_code: Events In Python. (line 272) a61680 2 * gdb_init_reader: Writing JIT Debug Info Readers. (line 20) d61686 1 a61686 1 (line 170) a61740 1 * Inferior.threads: Inferiors In Python. (line 76) d61743 1 d61751 1 a61751 1 * InferiorDeletedEvent.inferior: Events In Python. (line 247) d61786 1 a61786 1 * info copying: Help. (line 175) a61797 1 * info frame, show the source language: Show. (line 15) d61800 1 d61841 1 a61841 1 * info set: Help. (line 158) d61870 1 a61870 1 * info warranty: Help. (line 179) d61920 1 a61920 1 (line 177) d62040 1 a62040 1 (line 214) d62284 2 a62285 2 * MemoryChangedEvent.address: Events In Python. (line 194) * MemoryChangedEvent.length: Events In Python. (line 197) d62296 2 d62304 4 a62307 2 * MICommand.__init__: GDB/MI Commands In Python. (line 10) a62311 4 * MissingDebugHandler.__call__: Missing Debug Info In Python. (line 49) * MissingDebugHandler.__init__: Missing Debug Info In Python. (line 43) d62321 1 a62321 1 * NewInferiorEvent.inferior: Events In Python. (line 236) d62323 2 a62324 2 * NewProgspaceEvent.progspace: Events In Python. (line 320) * NewThreadEvent.inferior_thread: Events In Python. (line 255) a62326 2 * next&: Background Execution. (line 34) d62330 2 d62350 1 a62363 1 * objfile?: Objfiles In Guile. (line 17) a62378 17 * Parameter: Parameters In Python. (line 6) * Parameter <1>: Parameters In Guile. (line 6) * parameter-value: Parameters In Guile. (line 105) * Parameter.get_set_string: Parameters In Python. (line 96) * Parameter.get_show_string: Parameters In Python. (line 126) * Parameter.set_doc: Parameters In Python. (line 56) * Parameter.show_doc: Parameters In Python. (line 72) * Parameter.value: Parameters In Python. (line 88) * Parameter.__init__: Parameters In Python. (line 18) * parameter?: Parameters In Guile. (line 101) d62381 1 a62381 1 * PARAM_AUTO_BOOLEAN <1>: Parameters In Guile. (line 122) d62384 1 a62384 1 * PARAM_BOOLEAN <1>: Parameters In Guile. (line 118) d62387 1 a62387 1 * PARAM_ENUM <1>: Parameters In Guile. (line 160) d62390 1 a62390 1 * PARAM_FILENAME <1>: Parameters In Guile. (line 156) d62395 1 a62395 1 * PARAM_OPTIONAL_FILENAME <1>: Parameters In Guile. (line 153) d62398 1 a62398 1 * PARAM_STRING <1>: Parameters In Guile. (line 143) d62401 1 a62401 1 * PARAM_STRING_NOESCAPE <1>: Parameters In Guile. (line 149) d62404 1 a62404 1 * PARAM_UINTEGER <1>: Parameters In Guile. (line 127) d62407 1 a62407 1 * PARAM_ZINTEGER <1>: Parameters In Guile. (line 132) d62410 1 a62410 1 * PARAM_ZUINTEGER <1>: Parameters In Guile. (line 135) d62413 18 a62430 1 * PARAM_ZUINTEGER_UNLIMITED <1>: Parameters In Guile. (line 138) d62481 5 a62491 5 * pretty_printer.child: Pretty Printing API. (line 116) * pretty_printer.children: Pretty Printing API. (line 24) * pretty_printer.display_hint: Pretty Printing API. (line 46) * pretty_printer.num_children: Pretty Printing API. (line 109) * pretty_printer.to_string: Pretty Printing API. (line 78) d62510 1 d62525 2 a62528 2 * Progspace.objfile_for_address: Progspaces In Python. (line 113) a62536 1 * progspace?: Progspaces In Guile. (line 17) d62552 1 a62553 1 * quit [EXPRESSION]: Quitting GDB. (line 6) d62657 3 d62663 3 a62665 3 * register-parameter!: Parameters In Guile. (line 96) * RegisterChangedEvent.frame: Events In Python. (line 204) * RegisterChangedEvent.regnum: Events In Python. (line 207) a62668 3 * register_disassembler: Disassembly In Python. (line 452) * register_xmethod_matcher: Xmethod API. (line 82) d62675 1 a62675 1 (line 161) d62729 1 a62729 1 * set: Help. (line 146) d62844 1 a62844 1 * set follow-exec-mode: Forks. (line 106) d62903 1 a62903 1 (line 192) d62998 1 d63023 1 a63023 1 * set-parameter-value!: Parameters In Guile. (line 109) a63028 1 * set_debug_traps: Stub Contents. (line 9) d63034 1 a63034 1 * show: Help. (line 151) d63087 1 a63087 1 * show configuration: Help. (line 184) d63090 1 a63090 1 * show copying: Help. (line 175) d63186 1 a63186 1 (line 200) d63255 2 a63256 2 * show version: Help. (line 165) * show warranty: Help. (line 179) d63332 1 a63332 1 (line 377) d63334 1 a63334 1 (line 389) d63336 1 a63336 1 (line 355) d63338 1 a63338 1 (line 435) d63340 1 a63340 1 (line 406) d63342 1 a63342 1 (line 329) d63344 1 a63344 1 (line 370) d63346 1 a63346 1 (line 337) d63348 1 a63348 1 (line 416) d63350 1 a63350 31 (line 323) * symbol-addr-class: Symbols In Guile. (line 48) * symbol-argument?: Symbols In Guile. (line 58) * symbol-constant?: Symbols In Guile. (line 62) * symbol-file: Files. (line 51) * symbol-function?: Symbols In Guile. (line 65) * symbol-line: Symbols In Guile. (line 32) * symbol-linkage-name: Symbols In Guile. (line 39) * symbol-name: Symbols In Guile. (line 36) * symbol-needs-frame?: Symbols In Guile. (line 53) * symbol-print-name: Symbols In Guile. (line 43) * symbol-symtab: Symbols In Guile. (line 28) * symbol-type: Symbols In Guile. (line 24) * symbol-valid?: Symbols In Guile. (line 17) * symbol-value: Symbols In Guile. (line 72) * symbol-variable?: Symbols In Guile. (line 69) * Symbol.addr_class: Symbols In Python. (line 119) * Symbol.is_argument: Symbols In Python. (line 129) * Symbol.is_constant: Symbols In Python. (line 132) * Symbol.is_function: Symbols In Python. (line 135) * Symbol.is_valid: Symbols In Python. (line 145) * Symbol.is_variable: Symbols In Python. (line 138) * Symbol.line: Symbols In Python. (line 102) * Symbol.linkage_name: Symbols In Python. (line 110) * Symbol.name: Symbols In Python. (line 106) * Symbol.needs_frame: Symbols In Python. (line 124) * Symbol.print_name: Symbols In Python. (line 114) * Symbol.symtab: Symbols In Python. (line 97) * Symbol.type: Symbols In Python. (line 92) * Symbol.value: Symbols In Python. (line 152) * symbol?: Symbols In Guile. (line 13) a63351 1 * SYMBOL_FUNCTIONS_DOMAIN: Symbols In Guile. (line 147) d63354 1 a63389 1 * SYMBOL_TYPES_DOMAIN: Symbols In Guile. (line 150) d63392 1 a63394 1 * SYMBOL_VARIABLES_DOMAIN: Symbols In Guile. (line 143) d63397 41 d63450 2 a63467 12 * symtab?: Symbol Tables In Guile. (line 17) * Symtab_and_line.is_valid: Symbol Tables In Python. (line 34) * Symtab_and_line.last: Symbol Tables In Python. (line 24) * Symtab_and_line.line: Symbol Tables In Python. (line 28) * Symtab_and_line.pc: Symbol Tables In Python. (line 20) * Symtab_and_line.symtab: Symbol Tables In Python. (line 16) d63511 1 a63511 1 * ThreadExitedEvent.inferior_thread: Events In Python. (line 263) a63548 45 * type-array: Types In Guile. (line 52) * type-code: Types In Guile. (line 25) * type-const: Types In Guile. (line 99) * type-field: Types In Guile. (line 129) * type-fields: Types In Guile. (line 115) * type-has-field-deep?: Guile Types Module. (line 32) * type-has-field?: Types In Guile. (line 142) * type-name: Types In Guile. (line 34) * type-num-fields: Types In Guile. (line 112) * type-pointer: Types In Guile. (line 73) * type-print-name: Types In Guile. (line 38) * type-range: Types In Guile. (line 77) * type-reference: Types In Guile. (line 81) * type-sizeof: Types In Guile. (line 43) * type-strip-typedefs: Types In Guile. (line 48) * type-tag: Types In Guile. (line 29) * type-target: Types In Guile. (line 85) * type-unqualified: Types In Guile. (line 107) * type-vector: Types In Guile. (line 60) * type-volatile: Types In Guile. (line 103) * Type.alignof: Types In Python. (line 35) * Type.array: Types In Python. (line 176) * Type.code: Types In Python. (line 41) * Type.const: Types In Python. (line 197) * Type.dynamic: Types In Python. (line 45) * Type.fields: Types In Python. (line 115) * Type.is_array_like: Types In Python. (line 99) * Type.is_scalar: Types In Python. (line 86) * Type.is_signed: Types In Python. (line 91) * Type.is_string_like: Types In Python. (line 108) * Type.name: Types In Python. (line 65) * Type.objfile: Types In Python. (line 82) * Type.optimized_out: Types In Python. (line 254) * Type.pointer: Types In Python. (line 220) * Type.range: Types In Python. (line 210) * Type.reference: Types In Python. (line 216) * Type.sizeof: Types In Python. (line 69) * Type.strip_typedefs: Types In Python. (line 224) * Type.tag: Types In Python. (line 76) * Type.target: Types In Python. (line 228) * Type.template_argument: Types In Python. (line 242) * Type.unqualified: Types In Python. (line 205) * Type.vector: Types In Python. (line 184) * Type.volatile: Types In Python. (line 201) * type?: Types In Guile. (line 11) d63609 45 d63749 6 d63781 2 a63784 2 * Value.reference_value: Values From Inferior. (line 259) d63793 1 a63793 4 * Value.__init__: Values From Inferior. (line 126) * Value.__init__ <1>: Values From Inferior. (line 160) a63794 1 * value?: Arithmetic In Guile. (line 59) * value?: Values From Inferior In Guile. (line 41) d63843 1 d63845 1 a63845 1 * XMethodMatcher.__init__: Xmethod API. (line 43) a63847 1 * XMethodWorker.__call__: Xmethod API. (line 73) d63860 872 a64731 872 Node: Top1701 Node: Summary5330 Node: Free Software7191 Node: Free Documentation7931 Node: Contributors12865 Node: Sample Session21896 Node: Invocation28733 Node: Invoking GDB29284 Node: File Options31679 Ref: --readnever35305 Node: Mode Options35779 Ref: -nx36006 Ref: -nh36118 Node: Startup42893 Ref: Option -init-eval-command44118 Node: Initialization Files45894 Ref: System Wide Init Files49501 Ref: Home Directory Init File50782 Ref: Init File in the Current Directory during Startup51945 Ref: Initialization Files-Footnote-152668 Ref: Initialization Files-Footnote-252777 Node: Quitting GDB52886 Node: Shell Commands53828 Ref: pipe54949 Node: Logging Output56463 Node: Commands57582 Node: Command Syntax58398 Node: Command Settings60570 Node: Completion63583 Ref: Completion-Footnote-170926 Node: Filename Arguments71086 Node: Command Options73557 Node: Help75979 Node: Running83549 Node: Compilation84802 Node: Starting86881 Ref: set exec-wrapper92671 Ref: set startup-with-shell93760 Ref: set auto-connect-native-target94821 Node: Arguments99293 Node: Environment100562 Ref: set environment102444 Ref: unset environment103626 Node: Working Directory104632 Ref: set cwd command105204 Ref: cd command106144 Node: Input/Output106838 Node: Attach108898 Ref: set exec-file-mismatch110115 Node: Kill Process112251 Node: Inferiors Connections and Programs113244 Ref: add_inferior_cli118172 Ref: remove_inferiors_cli120190 Node: Inferior-Specific Breakpoints124126 Node: Threads125835 Ref: thread numbers127958 Ref: thread ID lists128848 Ref: global thread numbers129888 Ref: info_threads131423 Ref: thread apply all134081 Ref: set libthread-db-search-path138931 Node: Forks141129 Node: Checkpoint/Restart147695 Ref: Checkpoint/Restart-Footnote-1152223 Node: Stopping152258 Node: Breakpoints153566 Node: Set Breaks156823 Node: Set Watchpoints180730 Node: Set Catchpoints190266 Ref: catch syscall195764 Node: Delete Breaks203529 Node: Disabling206251 Node: Conditions209670 Node: Break Commands215592 Node: Dynamic Printf219181 Node: Save Breakpoints224241 Node: Static Probe Points225416 Ref: enable probes227964 Ref: Static Probe Points-Footnote-1229594 Ref: Static Probe Points-Footnote-2229754 Node: Error in Breakpoints229894 Node: Breakpoint-related Warnings230630 Node: Continuing and Stepping232957 Ref: range stepping242765 Node: Skipping Over Functions and Files243845 Node: Signals249715 Ref: stepping and signal handlers254259 Ref: stepping into signal handlers255055 Ref: extra signal information256288 Node: Thread Stops258754 Node: All-Stop Mode259889 Ref: set scheduler-locking261374 Node: Non-Stop Mode264231 Node: Background Execution267644 Node: Thread-Specific Breakpoints269860 Node: Interrupted System Calls272089 Node: Observer Mode273603 Node: Reverse Execution277039 Ref: Reverse Execution-Footnote-1281957 Ref: Reverse Execution-Footnote-2282584 Node: Process Record and Replay282634 Node: Stack304196 Node: Frames305813 Node: Backtrace308151 Ref: backtrace-command308488 Ref: set backtrace past-main314935 Ref: set backtrace past-entry315263 Ref: set backtrace limit315830 Ref: Backtrace-Footnote-1316454 Node: Selection316642 Node: Frame Info321425 Node: Frame Apply325847 Node: Frame Filter Management330277 Ref: disable frame-filter all330805 Node: Source335113 Node: List336239 Node: Location Specifications339879 Node: Linespec Locations344483 Node: Explicit Locations347889 Node: Address Locations351108 Node: Edit352866 Ref: Edit-Footnote-1354553 Node: Search354788 Node: Source Path355596 Ref: set substitute-path364536 Node: Machine Code366756 Ref: disassemble368754 Node: Disable Reading Source378742 Node: Data379504 Ref: print options380343 Node: Expressions391385 Node: Ambiguous Expressions393488 Node: Variables396718 Node: Arrays403316 Node: Output Formats405847 Ref: Output Formats-Footnote-1409416 Node: Memory409573 Ref: addressable memory unit416528 Node: Memory Tagging418022 Node: Auto Display420705 Node: Print Settings425255 Ref: set print address425553 Ref: set print symbol429215 Ref: set print array429703 Ref: set print array-indexes430031 Ref: set print nibbles430517 Ref: set print characters431064 Ref: set print elements432131 Ref: set print frame-arguments433251 Ref: set print raw-frame-arguments435420 Ref: set print entry-values435836 Ref: set print frame-info440215 Ref: set print repeats441881 Ref: set print max-depth442523 Ref: set print memory-tag-violations444215 Ref: set print null-stop444642 Ref: set print pretty444966 Ref: set print raw-values445553 Ref: set print union446570 Ref: set print object448876 Ref: set print static-members449670 Ref: set print vtbl450347 Node: Pretty Printing450731 Node: Pretty-Printer Introduction451247 Node: Pretty-Printer Example453004 Node: Pretty-Printer Commands453784 Node: Value History456668 Node: Convenience Vars459090 Node: Convenience Funs466868 Ref: $_shell convenience function471672 Node: Registers477871 Ref: info_registers_reggroup478528 Ref: standard registers479079 Ref: Registers-Footnote-1484030 Node: Floating Point Hardware484425 Node: Vector Unit484957 Node: OS Information485344 Ref: linux info os infotypes487368 Node: Memory Region Attributes491959 Node: Dump/Restore Files496623 Node: Core File Generation499026 Ref: set use-coredump-filter500697 Ref: set dump-excluded-mappings502145 Node: Character Sets502427 Node: Caching Target Data508792 Ref: Caching Target Data-Footnote-1511684 Node: Searching Memory511922 Node: Value Sizes515065 Ref: set max-value-size515492 Node: Optimized Code516717 Node: Inline Functions518394 Node: Tail Call Frames521021 Ref: set debug entry-values523159 Node: Macros527223 Ref: Macros-Footnote-1534841 Node: Tracepoints534994 Node: Set Tracepoints537056 Node: Create and Delete Tracepoints539994 Node: Enable and Disable Tracepoints546449 Node: Tracepoint Passcounts547689 Node: Tracepoint Conditions549100 Node: Trace State Variables550794 Node: Tracepoint Actions552989 Node: Listing Tracepoints559774 Node: Listing Static Tracepoint Markers561476 Node: Starting and Stopping Trace Experiments563324 Ref: disconnected tracing565069 Node: Tracepoint Restrictions569489 Node: Analyze Collected Data573258 Node: tfind574564 Node: tdump579046 Node: save tracepoints581561 Node: Tracepoint Variables582057 Node: Trace Files583185 Node: Overlays585561 Node: How Overlays Work586281 Ref: A code overlay588816 Node: Overlay Commands592249 Node: Automatic Overlay Debugging596431 Node: Overlay Sample Program598570 Node: Languages600307 Node: Setting601470 Node: Filenames603171 Node: Manually603982 Node: Automatically605191 Node: Show606252 Ref: show language606540 Node: Checks607574 Node: Type Checking608579 Node: Range Checking610408 Node: Supported Languages612815 Node: C614152 Node: C Operators615116 Node: C Constants619454 Node: C Plus Plus Expressions622333 Node: C Defaults625693 Node: C Checks626361 Node: Debugging C626921 Node: Debugging C Plus Plus627405 Node: Decimal Floating Point633011 Node: D634281 Node: Go634539 Node: Objective-C635633 Node: Method Names in Commands636096 Node: The Print Command with Objective-C637787 Node: OpenCL C638438 Node: OpenCL C Datatypes638713 Node: OpenCL C Expressions639088 Node: OpenCL C Operators639445 Node: Fortran639677 Node: Fortran Types640668 Node: Fortran Operators642585 Node: Fortran Intrinsics643654 Node: Special Fortran Commands646282 Node: Pascal647683 Node: Rust648194 Node: Modula-2651288 Node: M2 Operators652261 Node: Built-In Func/Proc655259 Node: M2 Constants658173 Node: M2 Types659774 Node: M2 Defaults662992 Node: Deviations663593 Node: M2 Checks664694 Node: M2 Scope665511 Node: GDB/M2666535 Node: Ada667448 Node: Ada Mode Intro668752 Node: Omissions from Ada670254 Node: Additions to Ada674544 Node: Overloading support for Ada678915 Node: Stopping Before Main Program680555 Node: Ada Exceptions681102 Node: Ada Tasks682301 Node: Ada Tasks and Core Files690679 Node: Ravenscar Profile691526 Node: Ada Source Character Set693709 Node: Ada Glitches694506 Node: Unsupported Languages698526 Node: Symbols699216 Ref: quoting names699819 Node: Altering734753 Node: Assignment735791 Node: Jumping738897 Node: Signaling741713 Node: Returning744642 Node: Calling747993 Ref: stack unwind settings749568 Ref: set unwind-on-timeout750872 Node: Patching758238 Node: Compiling and Injecting Code759352 Ref: set debug compile762979 Ref: set debug compile-cplus-types763229 Node: GDB Files773251 Node: Files774099 Ref: Shared Libraries788841 Ref: Files-Footnote-1801020 Node: File Caching801149 Node: Separate Debug Files802283 Ref: build ID803524 Ref: debug-file-directory805992 Node: MiniDebugInfo814724 Node: Index Files817175 Node: Debug Names821261 Node: Symbol Errors822567 Node: Data Files826183 Node: Targets827139 Node: Active Targets828619 Node: Target Commands829693 Ref: load834082 Ref: flash-erase835275 Node: Byte Order835335 Node: Remote Debugging836774 Node: Connecting838041 Ref: --multi Option in Types of Remote Connnections840267 Ref: Attaching in Types of Remote Connections841682 Ref: Host and target files842562 Node: File Transfer851184 Node: Server852123 Ref: Running gdbserver853699 Ref: Attaching to a program855917 Ref: Other Command-Line Arguments for gdbserver858442 Ref: Monitor Commands for gdbserver862782 Ref: Server-Footnote-1868839 Node: Remote Configuration868959 Ref: set remotebreak870219 Ref: set remote hardware-watchpoint-limit871681 Ref: set remote hardware-breakpoint-limit871681 Ref: set remote hardware-watchpoint-length-limit872183 Ref: set remote exec-file872638 Node: Remote Stub886051 Node: Stub Contents888946 Node: Bootstrapping891053 Node: Debug Session894868 Node: Configurations896909 Node: Native897678 Node: BSD libkvm Interface898304 Node: Process Information899356 Node: DJGPP Native904980 Node: Cygwin Native911533 Node: Non-debug DLL Symbols916454 Node: Hurd Native920693 Node: Darwin925949 Node: FreeBSD927226 Node: Embedded OS927946 Node: Embedded Processors928357 Node: ARC929399 Node: ARM929946 Node: BPF932848 Node: M68K933328 Node: MicroBlaze933501 Node: MIPS Embedded934950 Node: OpenRISC 1000936247 Node: PowerPC Embedded937153 Node: AVR940560 Node: CRIS940932 Node: Super-H941910 Node: Architectures942969 Node: AArch64943409 Ref: vl944686 Ref: vq944797 Ref: vg944907 Ref: AArch64 SME944954 Ref: svl946691 Ref: svq946849 Ref: svg946961 Ref: aarch64 sme svcr947715 Ref: AArch64 SME2952762 Ref: AArch64 PAC954200 Node: x86956821 Ref: x86-Footnote-1961596 Node: Alpha961682 Node: MIPS961814 Node: HPPA965708 Node: PowerPC966230 Node: Nios II966966 Node: Sparc64967371 Node: S12Z969739 Node: AMD GPU970048 Ref: AMD GPU Signals974190 Ref: AMD GPU Attaching Restrictions979825 Node: Controlling GDB980537 Node: Prompt981480 Node: Editing983198 Node: Command History984508 Node: Screen Size989702 Node: Output Styling991718 Ref: style_disassembler_enabled993501 Node: Numbers1001485 Node: ABI1003467 Node: Auto-loading1006640 Ref: set auto-load off1007706 Ref: show auto-load1008342 Ref: info auto-load1009121 Node: Init File in the Current Directory1012397 Ref: set auto-load local-gdbinit1012972 Ref: show auto-load local-gdbinit1013154 Ref: info auto-load local-gdbinit1013318 Node: libthread_db.so.1 file1013466 Ref: set auto-load libthread-db1014405 Ref: show auto-load libthread-db1014536 Ref: info auto-load libthread-db1014673 Node: Auto-loading safe path1014857 Ref: set auto-load safe-path1016158 Ref: show auto-load safe-path1016897 Ref: add-auto-load-safe-path1017020 Node: Auto-loading verbose mode1019923 Ref: set debug auto-load1021086 Ref: show debug auto-load1021187 Node: Messages/Warnings1021309 Ref: confirmation requests1022743 Node: Debugging Output1023947 Ref: set debug amd-dbgapi-lib1025334 Ref: set debug amd-dbgapi1025955 Node: Other Misc Settings1036196 Node: Extending GDB1039390 Node: Sequences1041215 Node: Define1041877 Node: Hooks1047734 Node: Command Files1050100 Node: Output1055173 Ref: %V Format Specifier1059975 Ref: eval1060860 Node: Auto-loading sequences1061022 Ref: set auto-load gdb-scripts1061517 Ref: show auto-load gdb-scripts1061641 Ref: info auto-load gdb-scripts1061771 Node: Aliases1062002 Node: Command aliases default args1065453 Ref: Command aliases default args-Footnote-11069174 Node: Python1069328 Node: Python Commands1070499 Ref: set_python_print_stack1071874 Ref: Python Commands-Footnote-11074956 Node: Python API1075046 Node: Basic Python1078213 Ref: prompt_hook1090253 Ref: gdb_architecture_names1090851 Ref: gdbpy_connections1091198 Node: Threading in GDB1093863 Node: Exception Handling1096430 Node: Values From Inferior1099292 Ref: Value.assign1106247 Node: Types In Python1119555 Ref: Type.is_array_like1123553 Node: Pretty Printing API1132390 Node: Selecting Pretty-Printers1138978 Node: Writing a Pretty-Printer1141705 Node: Type Printing API1147217 Node: Frame Filter API1149833 Node: Frame Decorator API1157147 Ref: frame_args1160886 Node: Writing a Frame Filter1164214 Node: Unwinding Frames in Python1175688 Ref: gdb.PendingFrame.create_unwind_info1178981 Ref: gdb.unwinder.FrameId1183914 Ref: Managing Registered Unwinders1187285 Node: Xmethods In Python1188557 Node: Xmethod API1191453 Node: Writing an Xmethod1195265 Node: Inferiors In Python1201097 Ref: gdbpy_inferior_connection1202056 Ref: gdbpy_inferior_read_memory1204670 Ref: choosing attribute names1207078 Node: Events In Python1208217 Node: Threads In Python1222345 Ref: inferior_thread_ptid1223867 Node: Recordings In Python1227767 Node: CLI Commands In Python1235060 Node: GDB/MI Commands In Python1244775 Node: GDB/MI Notifications In Python1251432 Node: Parameters In Python1253117 Node: Functions In Python1261777 Node: Progspaces In Python1263994 Node: Objfiles In Python1270915 Node: Frames In Python1277915 Ref: gdbpy_frame_read_register1284235 Node: Blocks In Python1286559 Node: Symbols In Python1291226 Node: Symbol Tables In Python1301987 Node: Line Tables In Python1305208 Node: Breakpoints In Python1308047 Ref: python_breakpoint_thread1314682 Ref: python_breakpoint_inferior1315146 Node: Finish Breakpoints in Python1321680 Node: Lazy Strings In Python1323790 Node: Architectures In Python1326018 Ref: gdbpy_architecture_name1326479 Ref: gdbpy_architecture_registers1328770 Ref: gdbpy_architecture_reggroups1329091 Node: Registers In Python1329290 Node: Connections In Python1331560 Node: TUI Windows In Python1336392 Ref: python-window-click1341253 Node: Disassembly In Python1341739 Ref: DisassembleInfo Class1342131 Ref: Disassembler Class1347812 Ref: DisassemblerResult Class1350155 Ref: Disassembler Styling Parts1353821 Ref: Disassembler Style Constants1357110 Ref: builtin_disassemble1365067 Node: Missing Debug Info In Python1368666 Node: Python Auto-loading1374627 Ref: set auto-load python-scripts1375256 Ref: show auto-load python-scripts1375356 Ref: info auto-load python-scripts1375462 Node: Python modules1376596 Node: gdb.printing1376982 Node: gdb.types1378409 Node: gdb.prompt1381421 Node: Guile1383017 Node: Guile Introduction1383676 Node: Guile Commands1384514 Node: Guile API1386368 Node: Basic Guile1388365 Node: Guile Configuration1394047 Node: GDB Scheme Data Types1395023 Node: Guile Exception Handling1396855 Node: Values From Inferior In Guile1400889 Node: Arithmetic In Guile1416935 Node: Types In Guile1418566 Ref: Fields of a type in Guile1426811 Node: Guile Pretty Printing API1428199 Node: Selecting Guile Pretty-Printers1433939 Node: Writing a Guile Pretty-Printer1436315 Node: Commands In Guile1441500 Node: Parameters In Guile1452285 Ref: Parameters In Guile-Footnote-11459318 Node: Progspaces In Guile1459434 Node: Objfiles In Guile1462046 Node: Frames In Guile1464327 Node: Blocks In Guile1470906 Node: Symbols In Guile1475714 Node: Symbol Tables In Guile1484014 Node: Breakpoints In Guile1486977 Node: Lazy Strings In Guile1498102 Node: Architectures In Guile1500393 Node: Disassembly In Guile1504700 Node: I/O Ports in Guile1507902 Node: Memory Ports in Guile1508458 Node: Iterators In Guile1512309 Node: Guile Auto-loading1516598 Ref: set auto-load guile-scripts1517221 Ref: show auto-load guile-scripts1517319 Ref: info auto-load guile-scripts1517423 Node: Guile Modules1518382 Node: Guile Printing Module1518704 Node: Guile Types Module1519523 Node: Auto-loading extensions1520816 Node: objfile-gdbdotext file1522265 Ref: set auto-load scripts-directory1523935 Ref: with-auto-load-dir1524311 Ref: show auto-load scripts-directory1525130 Ref: add-auto-load-scripts-directory1525210 Node: dotdebug_gdb_scripts section1525686 Node: Which flavor to choose?1529436 Node: Multiple Extension Languages1531257 Node: Interpreters1532305 Node: TUI1535787 Node: TUI Overview1536835 Node: TUI Keys1539594 Node: TUI Single Key Mode1542317 Node: TUI Mouse Support1543651 Node: TUI Commands1544689 Ref: info_win_command1545656 Node: TUI Configuration1551597 Ref: tui-mouse-events1553360 Node: Emacs1553936 Node: GDB/MI1559373 Node: GDB/MI General Design1562162 Node: Context management1564682 Node: Asynchronous and non-stop modes1568469 Node: Thread groups1571424 Node: GDB/MI Command Syntax1573714 Node: GDB/MI Input Syntax1573957 Node: GDB/MI Output Syntax1575507 Node: GDB/MI Compatibility with CLI1579092 Node: GDB/MI Development and Front Ends1579829 Node: GDB/MI Output Records1584208 Node: GDB/MI Result Records1584614 Node: GDB/MI Stream Records1585964 Node: GDB/MI Async Records1587229 Node: GDB/MI Breakpoint Information1597767 Node: GDB/MI Frame Information1603629 Node: GDB/MI Thread Information1604911 Node: GDB/MI Ada Exception Information1606381 Node: GDB/MI Simple Examples1606931 Node: GDB/MI Command Description Format1609167 Node: GDB/MI Breakpoint Commands1610047 Ref: -break-insert1617321 Node: GDB/MI Catchpoint Commands1631955 Node: Shared Library GDB/MI Catchpoint Commands1632368 Node: Ada Exception GDB/MI Catchpoint Commands1634026 Node: C++ Exception GDB/MI Catchpoint Commands1637576 Node: GDB/MI Program Context1641592 Node: GDB/MI Thread Commands1645860 Node: GDB/MI Ada Tasking Commands1649161 Node: GDB/MI Program Execution1651433 Node: GDB/MI Stack Manipulation1664146 Ref: -stack-list-arguments1666070 Ref: -stack-list-frames1669900 Ref: -stack-list-locals1674162 Ref: -stack-list-variables1675719 Node: GDB/MI Variable Objects1677253 Ref: -var-set-format1687195 Ref: -var-list-children1688575 Ref: -var-update1697383 Ref: -var-set-frozen1700320 Ref: -var-set-update-range1701105 Ref: -var-set-visualizer1701638 Node: GDB/MI Data Manipulation1703197 Node: GDB/MI Tracepoint Commands1726061 Node: GDB/MI Symbol Query1738029 Ref: -symbol-info-functions1738223 Ref: -symbol-info-module-functions1742722 Ref: -symbol-info-module-variables1745704 Ref: -symbol-info-modules1749439 Ref: -symbol-info-types1751347 Ref: -symbol-info-variables1753332 Node: GDB/MI File Commands1758431 Node: GDB/MI Target Manipulation1768270 Node: GDB/MI File Transfer Commands1774928 Node: GDB/MI Ada Exceptions Commands1776251 Node: GDB/MI Support Commands1777604 Node: GDB/MI Miscellaneous Commands1782710 Ref: -interpreter-exec1794875 Node: Annotations1798847 Node: Annotations Overview1799778 Node: Server Prefix1802241 Node: Prompting1802975 Node: Errors1804492 Node: Invalidation1805388 Node: Annotations for Running1805867 Node: Source Annotations1807401 Node: Debugger Adapter Protocol1808330 Node: JIT Interface1812506 Node: Declarations1814320 Node: Registering Code1815707 Node: Unregistering Code1816679 Node: Custom Debug Info1817306 Node: Using JIT Debug Info Readers1818602 Node: Writing JIT Debug Info Readers1819614 Node: In-Process Agent1821809 Ref: Control Agent1823752 Node: In-Process Agent Protocol1824619 Node: IPA Protocol Objects1825410 Ref: agent expression object1826408 Ref: tracepoint action object1826613 Ref: tracepoint object1826693 Node: IPA Protocol Commands1829223 Node: GDB Bugs1830623 Node: Bug Criteria1831355 Node: Bug Reporting1832232 Node: Command Line Editing1839209 Node: Introduction and Notation1839861 Node: Readline Interaction1841482 Node: Readline Bare Essentials1842671 Node: Readline Movement Commands1844452 Node: Readline Killing Commands1845410 Node: Readline Arguments1847326 Node: Searching1848368 Node: Readline Init File1850518 Node: Readline Init File Syntax1851669 Node: Conditional Init Constructs1871924 Node: Sample Init File1876118 Node: Bindable Readline Commands1879240 Node: Commands For Moving1880292 Node: Commands For History1882048 Node: Commands For Text1886808 Node: Commands For Killing1890508 Node: Numeric Arguments1893219 Node: Commands For Completion1894356 Node: Keyboard Macros1896322 Node: Miscellaneous Commands1897007 Node: Readline vi Mode1900926 Node: Using History Interactively1901836 Node: History Interaction1902351 Node: Event Designators1904247 Node: Word Designators1905519 Node: Modifiers1907277 Node: In Memoriam1908820 Node: Formatting Documentation1909703 Ref: Formatting Documentation-Footnote-11913019 Node: Installing GDB1913085 Node: Requirements1913657 Ref: MPFR1915301 Ref: Expat1916933 Node: Running Configure1919812 Node: Separate Objdir1922518 Node: Config Names1925402 Node: Configure Options1926849 Node: System-wide configuration1935992 Node: System-wide Configuration Scripts1938529 Node: Maintenance Commands1939713 Ref: maint info breakpoints1941438 Ref: maint info python-disassemblers1944243 Ref: maint packet1951359 Ref: maint check libthread-db1953307 Ref: maint_libopcodes_styling1971461 Node: Remote Protocol1977012 Node: Overview1977725 Ref: Binary Data1980279 Node: Standard Replies1983487 Ref: textual error reply1984332 Node: Packets1984434 Ref: thread-id syntax1985342 Ref: extended mode1986787 Ref: ? packet1987045 Ref: bc1988525 Ref: bs1988735 Ref: read registers packet1990317 Ref: cycle step packet1992664 Ref: write register packet1995384 Ref: step with signal packet1996328 Ref: vCont packet1997732 Ref: vCtrlC packet2000911 Ref: vKill packet2003224 Ref: X packet2004688 Ref: insert breakpoint or watchpoint packet2005022 Node: Stop Reply Packets2009013 Ref: swbreak stop reason2012264 Ref: thread clone event2015797 Ref: thread create event2016177 Ref: thread exit event2017380 Node: General Query Packets2019628 Ref: qCRC packet2022458 Ref: QEnvironmentHexEncoded2025250 Ref: QEnvironmentUnset2026480 Ref: QEnvironmentReset2027424 Ref: QSetWorkingDir packet2028368 Ref: qMemTags2032810 Ref: qIsAddressTagged2033552 Ref: QMemTags2034039 Ref: QNonStop2037150 Ref: QCatchSyscalls2037629 Ref: QPassSignals2038998 Ref: QProgramSignals2040004 Ref: QThreadEvents2041367 Ref: QThreadOptions2042467 Ref: qSearch memory2046418 Ref: QStartNoAckMode2046725 Ref: qSupported2047149 Ref: multiprocess extensions2062765 Ref: install tracepoint in tracing2064795 Ref: qThreadExtraInfo2069126 Ref: qXfer read2070252 Ref: qXfer auxiliary vector read2071485 Ref: qXfer btrace read2071833 Ref: qXfer btrace-conf read2072898 Ref: qXfer executable filename read2073249 Ref: qXfer target description read2073864 Ref: qXfer library list read2074298 Ref: qXfer svr4 library list read2074954 Ref: qXfer memory map read2077209 Ref: qXfer sdata read2077596 Ref: qXfer siginfo read2078062 Ref: qXfer threads read2078458 Ref: qXfer traceframe info read2078861 Ref: qXfer unwind info block2079279 Ref: qXfer fdpic loadmap read2079513 Ref: qXfer osdata read2079929 Ref: qXfer write2080083 Ref: qXfer siginfo write2080801 Ref: General Query Packets-Footnote-12083060 Node: Architecture-Specific Protocol Details2083387 Node: ARM-Specific Protocol Details2083896 Node: ARM Breakpoint Kinds2084169 Node: ARM Memory Tag Types2084529 Node: MIPS-Specific Protocol Details2084828 Node: MIPS Register packet Format2085111 Node: MIPS Breakpoint Kinds2086038 Node: Tracepoint Packets2086456 Ref: QTEnable2095572 Ref: QTDisable2095768 Ref: qTfSTM2101305 Ref: qTsSTM2101305 Ref: qTSTMat2102186 Ref: QTBuffer-size2103337 Node: Host I/O Packets2105194 Node: Interrupts2110776 Ref: interrupting remote targets2110920 Node: Notification Packets2113088 Node: Remote Non-Stop2118515 Node: Packet Acknowledgment2121631 Node: Examples2123746 Node: File-I/O Remote Protocol Extension2124340 Node: File-I/O Overview2124802 Node: Protocol Basics2127001 Node: The F Request Packet2129230 Node: The F Reply Packet2130131 Node: The Ctrl-C Message2131049 Node: Console I/O2132672 Node: List of Supported Calls2133888 Node: open2134250 Node: close2136758 Node: read2137141 Node: write2137750 Node: lseek2138521 Node: rename2139405 Node: unlink2140812 Node: stat/fstat2141759 Node: gettimeofday2142652 Node: isatty2143088 Node: system2143684 Node: Protocol-specific Representation of Datatypes2145226 Node: Integral Datatypes2145603 Node: Pointer Values2146410 Node: Memory Transfer2147114 Node: struct stat2147734 Node: struct timeval2149936 Node: Constants2150453 Node: Open Flags2150902 Node: mode_t Values2151243 Node: Errno Values2151735 Node: Lseek Flags2152545 Node: Limits2152730 Node: File-I/O Examples2153090 Node: Library List Format2154178 Node: Library List Format for SVR4 Targets2156960 Node: Memory Map Format2159737 Node: Thread List Format2162261 Node: Traceframe Info Format2163281 Node: Branch Trace Format2164967 Node: Branch Trace Configuration Format2166667 Node: Agent Expressions2167841 Node: General Bytecode Design2170662 Node: Bytecode Descriptions2175456 Node: Using Agent Expressions2188923 Node: Varying Target Capabilities2190900 Node: Rationale2192061 Node: Target Descriptions2199450 Node: Retrieving Descriptions2201393 Node: Target Description Format2202478 Node: Predefined Target Types2212353 Node: Enum Target Types2213936 Node: Standard Target Features2214931 Node: AArch64 Features2216954 Node: ARC Features2227169 Ref: ARC Features-Footnote-12228988 Node: ARM Features2229021 Node: i386 Features2238652 Node: LoongArch Features2240866 Node: MicroBlaze Features2241429 Node: MIPS Features2242011 Node: M68K Features2243202 Node: NDS32 Features2244189 Node: Nios II Features2245213 Node: OpenRISC 1000 Features2245620 Node: PowerPC Features2245986 Node: RISC-V Features2249956 Node: RX Features2251799 Node: S/390 and System z Features2252161 Node: Sparc Features2254301 Node: TIC6x Features2255206 Node: Operating System Information2255755 Node: Process list2256591 Node: Trace File Format2257654 Node: Index Section Format2260868 Node: Debuginfod2269485 Node: Debuginfod Settings2270321 Ref: set debuginfod enabled2270500 Node: Man Pages2272183 Node: gdb man2272643 Node: gdbserver man2280553 Node: gcore man2288475 Node: gdbinit man2289597 Node: gdb-add-index man2290836 Ref: gdb-add-index2290945 Node: Copying2291819 Node: GNU Free Documentation License2329380 Node: Concept Index2354527 Node: Command and Variable Index2508020 @ 1.1 log @gdb/info: Generate *.info with gtexinfo-7.1 from pkgsrc-2024Q2 by using mknative-gdb for amd64. @ text @d1 1 a1 1 This is gdb.info, produced by makeinfo version 7.1 from gdb.texinfo. d3 1 a3 1 Copyright © 1988-2024 Free Software Foundation, Inc. d23 2 a24 2 This is the Tenth Edition, of ‘Debugging with GDB: the GNU Source-Level Debugger’ for GDB (GDB) Version 15.1. d26 1 a26 1 Copyright © 1988-2024 Free Software Foundation, Inc. d109 1 a109 1 * Debuginfod:: Download debugging resources with ‘debuginfod’ d131 1 a131 1 • Start your program, specifying anything that might affect its d134 1 a134 1 • Make your program stop on specified conditions. d136 1 a136 1 • Examine what has happened, when your program has stopped. d138 1 a138 1 • Change things in your program, so you can experiment with d176 2 a177 2 GDB is “free software”, protected by the GNU General Public License (GPL). The GPL gives you the freedom to copy or adapt a licensed d290 1 a290 1 we cannot actually acknowledge everyone here. The file ‘ChangeLog’ in d480 1 a480 1 One of the preliminary versions of GNU ‘m4’ (a generic macro d483 6 a488 6 definition within another stop working. In the following short ‘m4’ session, we define a macro ‘foo’ which expands to ‘0000’; we then use the ‘m4’ built-in ‘defn’ to define ‘bar’ as the same thing. However, when we change the open quote string to ‘’ and the close quote string to ‘’, the same procedure fails to define a new synonym ‘baz’: d496 1 a496 1 define(bar,defn(`foo')) d526 3 a528 3 We need to see how the ‘m4’ built-in ‘changequote’ works. Having looked at the source, we know the relevant subroutine is ‘m4_changequote’, so we set a breakpoint there with the GDB ‘break’ command. d533 2 a534 2 Using the ‘run’ command, we start ‘m4’ running under GDB control; as long as control does not reach the ‘m4_changequote’ subroutine, the d544 2 a545 2 To trigger the breakpoint, we call ‘changequote’. GDB suspends execution of ‘m4’, displaying information about the context where it d554 1 a554 1 Now we use the command ‘n’ (‘next’) to advance execution to the next d561 2 a562 2 ‘set_quotes’ looks like a promising subroutine. We can go into it by using the command ‘s’ (‘step’) instead of ‘next’. ‘step’ goes to the d564 1 a564 1 ‘set_quotes’. d571 1 a571 1 The display that shows the subroutine where ‘m4’ is now suspended (and d573 3 a575 3 the stack. We can use the ‘backtrace’ command (which can also be spelled ‘bt’), to see where we are in the stack as a whole: the ‘backtrace’ command displays a stack frame for each active subroutine. d589 2 a590 2 times, we can use ‘s’; the next two times we use ‘n’ to avoid falling into the ‘xstrdup’ subroutine. d604 2 a605 2 ‘lquote’ and ‘rquote’ to see if they are in fact the new left and right quotes we specified. We use the command ‘p’ (‘print’) to see their d613 1 a613 1 ‘lquote’ and ‘rquote’ are indeed the new left and right quotes. To look d615 1 a615 1 current line with the ‘l’ (‘list’) command. d631 1 a631 1 Let us step past the two lines that set ‘len_lquote’ and ‘len_rquote’, d643 3 a645 3 That certainly looks wrong, assuming ‘len_lquote’ and ‘len_rquote’ are meant to be the lengths of ‘lquote’ and ‘rquote’ respectively. We can set them to better values using the ‘p’ command, since it can print the d654 3 a656 3 Is that enough to fix the problem of using the new quotes with the ‘m4’ built-in ‘defn’? We can allow ‘m4’ to continue executing with the ‘c’ (‘continue’) command, and then try the example that caused trouble d669 1 a669 1 lengths. We allow ‘m4’ exit by giving it an EOF as input: d674 2 a675 2 The message ‘Program exited normally.’ is from GDB; it indicates ‘m4’ has finished executing. We can end our GDB session with the GDB ‘quit’ d688 2 a689 2 • type ‘gdb’ to start GDB. • type ‘quit’, ‘exit’ or ‘Ctrl-d’ to exit. d704 1 a704 1 Invoke GDB by running the program ‘gdb’. Once started, GDB reads d707 1 a707 1 You can also run ‘gdb’ with a variety of arguments and options, to d725 1 a725 1 option ‘-p’, if you want to debug a running process: d730 1 a730 1 would attach GDB to process ‘1234’. With option ‘-p’ you can omit the d739 2 a740 2 You can optionally have ‘gdb’ pass any arguments after the executable file to the inferior using ‘--args’. This option stops option d743 2 a744 2 This will cause ‘gdb’ to debug ‘gcc’, and to set ‘gcc’'s command-line arguments (*note Arguments::) to ‘-O2 -c foo.c’. d746 3 a748 3 You can run ‘gdb’ without printing the front material, which describes GDB's non-warranty, by specifying ‘--silent’ (or ‘-q’/‘--quiet’): d759 2 a760 2 to display all available options and briefly describe their use (‘gdb -h’ is a shorter equivalent). d763 1 a763 1 sequential order. The order makes a difference when the ‘-x’ option is d781 1 a781 1 the arguments were specified by the ‘-se’ and ‘-c’ (or ‘-p’) options d783 1 a783 1 associated option flag as equivalent to the ‘-se’ option followed by d785 1 a785 1 option flag, if any, as equivalent to the ‘-c’/‘-p’ option followed by d790 1 a790 1 prefixing it with ‘./’, e.g. ‘./12345’. d796 1 a796 1 For the ‘-s’, ‘-e’, and ‘-se’ options, and their long form d798 1 a798 1 and/or executable file is the same as that used by the ‘file’ command. d804 1 a804 1 you prefer, you can flag option arguments with ‘--’ rather than ‘-’, d807 2 a808 2 ‘-symbols FILE’ ‘-s FILE’ d811 2 a812 2 ‘-exec FILE’ ‘-e FILE’ d816 1 a816 1 ‘-se FILE’ d819 2 a820 2 ‘-core FILE’ ‘-c FILE’ d823 3 a825 3 ‘-pid NUMBER’ ‘-p NUMBER’ Connect to process ID NUMBER, as with the ‘attach’ command. d827 2 a828 2 ‘-command FILE’ ‘-x FILE’ d830 1 a830 1 evaluated exactly as the ‘source’ command would. *Note Command d833 2 a834 2 ‘-eval-command COMMAND’ ‘-ex COMMAND’ d838 1 a838 1 It may also be interleaved with ‘-command’ as required. d843 2 a844 2 ‘-init-command FILE’ ‘-ix FILE’ d848 2 a849 2 ‘-init-eval-command COMMAND’ ‘-iex COMMAND’ d853 2 a854 2 ‘-early-init-command FILE’ ‘-eix FILE’ d858 2 a859 2 ‘-early-init-eval-command COMMAND’ ‘-eiex COMMAND’ d863 2 a864 2 ‘-directory DIRECTORY’ ‘-d DIRECTORY’ d867 2 a868 2 ‘-r’ ‘-readnow’ d874 1 a874 1 ‘--readnever’ d892 2 a893 2 ‘-nx’ ‘-n’ d897 1 a897 1 ‘-nh’ d903 3 a905 3 ‘-quiet’ ‘-silent’ ‘-q’ d909 3 a911 3 This can also be enabled using ‘set startup-quietly on’. The default is ‘off’. Use ‘show startup-quietly’ to see the current setting. Place ‘set startup-quietly on’ into your early d915 4 a918 4 ‘-batch’ Run in batch mode. Exit with status ‘0’ after processing all the command files specified with ‘-x’ (and all commands from initialization files, if not inhibited with ‘-n’). Exit with d922 1 a922 1 as if ‘set confirm off’ were in effect (*note Messages/Warnings::). d933 4 a936 4 ‘-batch-silent’ Run in batch mode exactly like ‘-batch’, but totally silently. All GDB output to ‘stdout’ is prevented (‘stderr’ is unaffected). This is much quieter than ‘-silent’ and would be useless for an d939 2 a940 2 This is particularly useful when using targets that give ‘Loading section’ messages, for example. d943 1 a943 1 writing directly to ‘stdout’, will also be made silent. d945 1 a945 1 ‘-return-child-result’ d950 1 a950 1 • GDB exits abnormally. E.g., due to an incorrect argument or d952 3 a954 3 it would have been without ‘-return-child-result’. • The user quits with an explicit value. E.g., ‘quit 1’. • The child process never runs, or is not allowed to terminate, d957 2 a958 2 This option is useful in conjunction with ‘-batch’ or ‘-batch-silent’, when GDB is being used as a remote program loader d961 2 a962 2 ‘-nowindows’ ‘-nw’ d967 2 a968 2 ‘-windows’ ‘-w’ d972 1 a972 1 ‘-cd DIRECTORY’ d976 2 a977 2 ‘-data-directory DIRECTORY’ ‘-D DIRECTORY’ d981 2 a982 2 ‘-fullname’ ‘-f’ d987 1 a987 1 format looks like two ‘\032’ characters, followed by the file name, d989 1 a989 1 newline. The Emacs-to-GDB interface program uses the two ‘\032’ d992 3 a994 3 ‘-annotate LEVEL’ This option sets the “annotation level” inside GDB. Its effect is identical to using ‘set annotate LEVEL’ (*note Annotations::). The d1005 1 a1005 1 ‘--args’ d1010 2 a1011 2 ‘-baud BPS’ ‘-b BPS’ d1015 1 a1015 1 ‘-l TIMEOUT’ d1019 2 a1020 2 ‘-tty DEVICE’ ‘-t DEVICE’ d1023 2 a1024 2 ‘-tui’ Activate the “Text User Interface” when starting. The Text User d1030 1 a1030 1 ‘-interpreter INTERP’ d1036 4 a1039 4 ‘--interpreter=mi’ (or ‘--interpreter=mi3’) causes GDB to use the “GDB/MI interface” version 3 (*note The GDB/MI Interface: GDB/MI.) included since GDB version 9.1. GDB/MI version 2 (‘mi2’), included in GDB 6.0 and version 1 (‘mi1’), included in GDB 5.3, are also d1042 1 a1042 1 ‘-write’ d1044 1 a1044 1 This is equivalent to the ‘set write on’ command inside GDB (*note d1047 1 a1047 1 ‘-statistics’ d1051 1 a1051 1 ‘-version’ d1055 1 a1055 1 ‘-configuration’ d1075 3 a1077 3 3. Executes commands and command files specified by the ‘-eiex’ and ‘-eix’ command line options in their specified order. Only a restricted set of commands can be used with ‘-eiex’ and ‘eix’, see d1091 3 a1093 3 7. Executes commands and command files specified by the ‘-iex’ and ‘-ix’ options in their specified order. Usually you should use the ‘-ex’ and ‘-x’ options instead, but this way you can apply settings d1099 2 a1100 2 any) in the current working directory as long as ‘set auto-load local-gdbinit’ is set to ‘on’ (*note Init File in the Current d1118 1 a1118 1 Option ‘-ex’ does not work because the auto-loading is then turned d1121 2 a1122 2 11. Executes commands and command files specified by the ‘-ex’ and ‘-x’ options in their specified order. *Note Command Files::, for d1125 1 a1125 1 12. Reads the command history recorded in the “history file”. *Note d1137 1 a1137 1 “command files” (*note Command Files::) and are processed by GDB in the d1141 1 a1141 1 in the order they will be loaded, you can use ‘gdb --help’. d1143 1 a1143 1 The “early initialization” file is loaded very early in GDB's d1146 2 a1147 2 initialized. Only ‘set’ or ‘source’ commands should be placed into an early initialization file, and the only ‘set’ commands that can be used d1154 1 a1154 1 passed to ‘--early-init-command’ or ‘-eix’ are also early initialization d1157 1 a1157 1 ‘--early-init-eval-command’ or ‘-eiex’. d1159 1 a1159 1 In contrast, the “general initialization” files are processed later, d1163 1 a1163 1 Throughout the rest of this document the term “initialization file” d1171 1 a1171 1 ‘set complaints’) can affect subsequent processing of command line d1188 6 a1193 6 • The file ‘gdb/gdbearlyinit’ within the directory pointed to by the environment variable ‘XDG_CONFIG_HOME’, if it is defined. • The file ‘.config/gdb/gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is defined. • The file ‘.gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is defined. d1196 2 a1197 2 • The file ‘Library/Preferences/gdb/gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is d1199 2 a1200 2 • The file ‘.gdbearlyinit’ within the directory pointed to by the environment variable ‘HOME’, if it is defined. d1203 1 a1203 1 file from being loaded using the ‘-nx’ or ‘-nh’ command line options, d1212 1 a1212 1 ‘system.gdbinit’ d1214 1 a1214 1 specified with the ‘--with-system-gdbinit’ configure option (*note d1218 1 a1218 1 ‘system.gdbinit.d’ d1220 1 a1220 1 specified with the ‘--with-system-gdbinit-dir’ configure option d1222 1 a1222 1 loaded in alphabetical order immediately after ‘system.gdbinit’ (if d1225 1 a1225 1 extension (‘.py’/‘.scm’) or be named with a ‘.gdb’ extension to be d1230 1 a1230 1 being loaded using the ‘-nx’ command line option, *note Choosing Modes: d1243 3 a1245 3 ‘$XDG_CONFIG_HOME/gdb/gdbinit’ ‘$HOME/.config/gdb/gdbinit’ ‘$HOME/.gdbinit’ d1248 2 a1249 2 ‘$HOME/Library/Preferences/gdb/gdbinit’ ‘$HOME/.gdbinit’ d1252 1 a1252 1 being loaded using the ‘-nx’ or ‘-nh’ command line options, *note d1255 2 a1256 2 The DJGPP port of GDB uses the name ‘gdb.ini’ instead of ‘.gdbinit’ or ‘gdbinit’, due to the limitations of file names imposed by DOS d1258 1 a1258 1 finds a ‘gdb.ini’ file in your home directory, it warns you about that d1264 4 a1267 4 GDB will check the current directory for a file called ‘.gdbinit’. It is loaded last, after command line options other than ‘-x’ and ‘-ex’ have been processed. The command line options ‘-x’ and ‘-ex’ are processed last, after ‘.gdbinit’ has been loaded, *note Choosing Files: d1274 1 a1274 1 from being loaded using the ‘-nx’ command line option, *note Choosing d1280 1 a1280 1 by the ‘HOME’ environment variable. d1283 1 a1283 1 by the ‘HOME’ environment variable. d1291 5 a1295 5 ‘quit [EXPRESSION]’ ‘exit [EXPRESSION]’ ‘q’ To exit GDB, use the ‘quit’ command (abbreviated ‘q’), the ‘exit’ command, or type an end-of-file character (usually ‘Ctrl-d’). If d1300 1 a1300 1 An interrupt (often ‘Ctrl-c’) does not exit from GDB, but rather d1307 1 a1307 1 you can release it with the ‘detach’ command (*note Debugging an d1318 1 a1318 1 ‘shell’ command. d1320 2 a1321 2 ‘shell COMMAND-STRING’ ‘!COMMAND-STRING’ d1323 4 a1326 4 needed between ‘!’ and COMMAND-STRING. On GNU and Unix systems, the environment variable ‘SHELL’, if it exists, determines which shell to run. Otherwise GDB uses the default shell (‘/bin/sh’ on GNU and Unix systems, ‘cmd.exe’ on MS-Windows, ‘COMMAND.COM’ on d1330 1 a1330 1 ‘$_shell’ convenience function. *Note $_shell convenience function::. d1332 2 a1333 2 The utility ‘make’ is often needed in development environments. You do not have to use the ‘shell’ command for this purpose in GDB: d1335 8 a1342 8 ‘make MAKE-ARGS’ Execute the ‘make’ program with the specified arguments. This is equivalent to ‘shell make MAKE-ARGS’. ‘pipe [COMMAND] | SHELL_COMMAND’ ‘| [COMMAND] | SHELL_COMMAND’ ‘pipe -d DELIM COMMAND DELIM SHELL_COMMAND’ ‘| -d DELIM COMMAND DELIM SHELL_COMMAND’ d1344 1 a1344 1 no space is needed around ‘|’. If no COMMAND is provided, the last d1347 1 a1347 1 In case the COMMAND contains a ‘|’, the option ‘-d DELIM’ can be d1380 1 a1380 1 The convenience variables ‘$_shell_exitcode’ and ‘$_shell_exitsignal’ d1382 1 a1382 1 launched by ‘shell’, ‘make’, ‘pipe’ and ‘|’. *Note Convenience d1394 1 a1394 1 ‘set logging enabled [on|off]’ d1396 1 a1396 1 ‘set logging file FILE’ d1398 5 a1402 5 ‘gdb.txt’. ‘set logging overwrite [on|off]’ By default, GDB will append to the logfile. Set ‘overwrite’ if you want ‘set logging enabled on’ to overwrite the logfile instead. ‘set logging redirect [on|off]’ d1404 1 a1404 1 logfile. Set ‘redirect’ if you want output to go only to the log d1406 1 a1406 1 ‘set logging debugredirect [on|off]’ d1408 1 a1408 1 logfile. Set ‘debugredirect’ if you want debug output to go only d1410 1 a1410 1 ‘show logging’ d1446 2 a1447 2 command ‘step’ accepts an argument which is the number of times to step, as in ‘step 5’. You can also use the ‘step’ command with no arguments. d1453 4 a1456 4 abbreviations are allowed; for example, ‘s’ is specially defined as equivalent to ‘step’ even though there are other commands whose names start with ‘s’. You can test abbreviations by using them as arguments to the ‘help’ command. d1459 1 a1459 1 previous command. Certain commands (for example, ‘run’) will not repeat d1464 1 a1464 1 The ‘list’ and ‘x’ commands, when you repeat them with , d1469 1 a1469 1 in a way similar to the common utility ‘more’ (*note Screen Size: Screen d1474 1 a1474 1 Any text from a ‘#’ to the end of the line is a comment; it does d1478 1 a1478 1 The ‘Ctrl-o’ binding is useful for repeating a complex sequence of d1490 2 a1491 2 variables or settings. These settings can be changed with the ‘set’ subcommands. For example, the ‘print’ command (*note Examining Data: d1493 2 a1494 2 the commands ‘set print elements NUMBER-OF-ELEMENTS’ and ‘set print array-indexes’, among others. d1506 1 a1506 1 The above ‘set print elements 10’ command changes the number of d1508 2 a1509 2 this limit of 10 to be used for printing ‘some_array’, then you must restore the limit back to 200, with ‘set print elements 200’. d1512 2 a1513 2 example, the ‘print’ command supports a number of options that allow overriding relevant global print settings as set by ‘set print’ d1519 1 a1519 1 Alternatively, you can use the ‘with’ command to change a setting d1522 2 a1523 2 ‘with SETTING [VALUE] [-- COMMAND]’ ‘w SETTING [VALUE] [-- COMMAND]’ d1526 2 a1527 2 SETTING is any setting you can change with the ‘set’ subcommands. VALUE is the value to assign to ‘setting’ while running ‘command’. d1532 1 a1532 1 (‘--’) separator. This is required because some settings accept d1542 1 a1542 1 The ‘with’ command is particularly useful when you want to override d1549 2 a1550 2 ‘with’ commands. For example, ‘with language ada -- with print elements 10’ temporarily changes the language to Ada and sets a d1572 2 a1573 2 GDB fills in the rest of the word ‘breakpoints’, since that is the only ‘info’ subcommand beginning with ‘bre’: d1577 2 a1578 2 You can either press at this point, to run the ‘info breakpoints’ command, or backspace and enter something else, if ‘breakpoints’ does d1580 2 a1581 2 ‘info breakpoints’ in the first place, you might as well just type immediately after ‘info bre’, to exploit command abbreviations rather d1588 2 a1589 2 a breakpoint on a subroutine whose name begins with ‘make_’, but when you type ‘b make_’ GDB just sounds the bell. Typing again d1603 1 a1603 1 input (‘b make_’ in the example) so you can finish the command. d1606 1 a1606 1 a number to follow, then ‘NUMBER’ will be shown among the available d1613 1 a1613 1 Here, the option expects a number (e.g., ‘100’), not literal ‘NUMBER’. d1617 4 a1620 4 you can press ‘M-?’ rather than pressing twice. ‘M-?’ means ‘ ?’. You can type this either by holding down a key designated as the shift on your keyboard (if there is one) while typing ‘?’, or as followed by ‘?’. d1634 2 a1635 2 ‘set max-completions LIMIT’ ‘set max-completions unlimited’ d1643 1 a1643 1 ‘show max-completions’ d1650 1 a1650 1 you may enclose words in ‘'’ (single quote marks) in GDB commands. d1654 1 a1654 1 This is because when completing expressions, GDB treats the ‘<’ d1659 5 a1663 5 interactively using the ‘print’ or ‘call’ commands, you may need to distinguish whether you mean the version of ‘name’ that was specialized for ‘int’, ‘name()’, or the version that was specialized for ‘float’, ‘name()’. To use the word-completion facilities in this situation, type a single quote ‘'’ at the beginning of the function d1665 1 a1665 1 than usual when you press or ‘M-?’ to request word completion: d1682 3 a1684 3 don't need to distinguish whether you mean the version of ‘name’ that takes an ‘int’ parameter, ‘name(int)’, or the version that takes a ‘float’ parameter, ‘name(float)’. d1695 2 a1696 2 Expressions: C Plus Plus Expressions. You can use the command ‘set overload-resolution off’ to disable overload resolution; see *note GDB d1709 2 a1710 2 This is because the ‘gdb_stdout’ is a variable of the type ‘struct ui_file’ that is defined in GDB sources as follows: d1754 1 a1754 1 example the user is adding ‘/path/that contains/two spaces/’ to the d1766 2 a1767 2 For example, to load the file ‘/path/with spaces/to/a file’ with the ‘file’ command (*note Commands to Specify Files: Files.), you can escape d1795 1 a1795 1 ‘print -pretty’. Similarly to command names, you can abbreviate a GDB d1805 3 a1807 3 abbreviations, e.g. ‘print -p’ (short for ‘print -pretty’ or printing negative ‘p’?), if you specify any command option, then you must use a double-dash (‘--’) delimiter to indicate the end of options. d1810 4 a1813 4 either ‘on’ or ‘off’. These are known as “boolean options”. Similarly to boolean settings commands--‘on’ and ‘off’ are the typical values, but any of ‘1’, ‘yes’ and ‘enable’ can also be used as "true" value, and any of ‘0’, ‘no’ and ‘disable’ can also be used as "false" value. You can d1822 1 a1822 1 completing on ‘-’ after the command name. For example: d1836 1 a1836 1 Here, the option expects a number (e.g., ‘100’), not literal ‘NUMBER’. d1839 1 a1839 1 (For more on using the ‘print’ command, see *note Examining Data: d1849 1 a1849 1 command ‘help’. d1851 3 a1853 3 ‘help’ ‘h’ You can use ‘help’ (abbreviated ‘h’) with no arguments to display a d1880 1 a1880 1 ‘help CLASS’ d1886 1 a1886 1 help display for the class ‘status’: d1908 2 a1909 2 ‘help COMMAND’ With a command name as ‘help’ argument, GDB displays a short d1918 1 a1918 1 ‘document’ command (*note document: Define.). GDB then considers d1924 2 a1925 2 ‘apropos [-v] REGEXP’ The ‘apropos’ command searches through all of the GDB commands and d1928 1 a1928 1 flag ‘-v’, which stands for ‘verbose’, indicates to output the full d1943 1 a1943 1 results in the below output, where ‘cut for 'thread apply’ is d1956 2 a1957 2 ‘complete ARGS’ The ‘complete ARGS’ command lists all the possible completions for d1972 1 a1972 1 In addition to ‘help’, you can use the GDB commands ‘info’ and ‘show’ d1975 2 a1976 2 each of them in the appropriate context. The listings under ‘info’ and under ‘show’ in the Command, Variable, and Function Index point to all d1979 2 a1980 2 ‘info’ This command (abbreviated ‘i’) is for describing the state of your d1982 4 a1985 4 function with ‘info args’, list the registers currently in use with ‘info registers’, or list the breakpoints you have set with ‘info breakpoints’. You can get a complete list of the ‘info’ sub-commands with ‘help info’. d1987 1 a1987 1 ‘set’ d1989 2 a1990 2 variable with ‘set’. For example, you can set the GDB prompt to a $-sign with ‘set prompt $’. d1992 6 a1997 6 ‘show’ In contrast to ‘info’, ‘show’ is for describing the state of GDB itself. You can change most of the things you can ‘show’, by using the related command ‘set’; for example, you can control what number system is used for displays with ‘set radix’, or simply inquire which is currently in use with ‘show radix’. d2000 1 a2000 1 you can use ‘show’ with no arguments; you may also use ‘info set’. d2003 2 a2004 2 Here are several miscellaneous ‘show’ subcommands, all of which are exceptional in lacking corresponding ‘set’ commands: d2006 1 a2006 1 ‘show version’ d2016 2 a2017 2 ‘show copying’ ‘info copying’ d2020 2 a2021 2 ‘show warranty’ ‘info warranty’ d2025 1 a2025 1 ‘show configuration’ d2028 2 a2029 2 ‘configure’ script and also configuration parameters detected automatically by ‘configure’. When reporting a GDB bug (*note GDB d2076 1 a2076 1 To request debugging information, specify the ‘-g’ option when you d2080 2 a2081 2 optimizations, using the ‘-O’ compiler option. However, some compilers are unable to handle the ‘-g’ and ‘-O’ options together. Using those d2085 1 a2085 1 GCC, the GNU C/C++ compiler, supports ‘-g’ with or without ‘-O’, d2087 1 a2087 1 _always_ use ‘-g’ whenever you compile a program. You may think your d2091 1 a2091 1 Older versions of the GNU C compiler permitted a variant option ‘-gg’ d2097 1 a2097 1 preprocessor macros in the debugging information if you specify the ‘-g’ d2100 1 a2100 1 specify the option ‘-g3’. d2117 3 a2119 3 ‘run’ ‘r’ Use the ‘run’ command to start your program under GDB. You must d2121 2 a2122 2 Getting In and Out of GDB: Invocation.), or by using the ‘file’ or ‘exec-file’ command (*note Commands to Specify Files: Files.). d2125 3 a2127 3 supports processes, ‘run’ creates an inferior process and makes that process run your program. In some environments without processes, ‘run’ jumps to the start of your program. Other targets, like ‘remote’, are d2133 1 a2133 1 then use ‘continue’ to run your program. You may need ‘load’ first d2145 1 a2145 1 ‘run’ command. If a shell is available on your target, the shell d2149 3 a2151 3 which shell is used with the ‘SHELL’ environment variable. If you do not define ‘SHELL’, GDB uses the default shell (‘/bin/sh’). You can disable use of any shell with the ‘set startup-with-shell’ d2156 1 a2156 1 can use the GDB commands ‘set environment’ and ‘unset environment’ d2161 2 a2162 2 You can set your program's working directory with the command ‘set cwd’. If you do not set any working directory with this command, d2171 1 a2171 1 in the ‘run’ command line, or you can use the ‘tty’ command to set d2180 1 a2180 1 When you issue the ‘run’ command, your program begins to execute d2183 1 a2183 1 you may call functions in your program, using the ‘print’ or ‘call’ d2191 1 a2191 1 ‘start’ d2193 1 a2193 1 With C or C++, the main procedure name is always ‘main’, but other d2199 1 a2199 1 The ‘start’ command does the equivalent of setting a temporary d2201 1 a2201 1 the ‘run’ command. d2203 1 a2203 1 Some programs contain an “elaboration” phase where some startup d2207 1 a2207 1 ‘main’ is called. It is therefore possible that the debugger stops d2212 2 a2213 2 ‘start’ command. These arguments will be given verbatim to the underlying ‘run’ command. Note that the same arguments will be d2215 1 a2215 1 ‘start’ or ‘run’. d2218 1 a2218 1 In these cases, using the ‘start’ command would stop the execution d2222 1 a2222 1 program or use the ‘starti’ command. d2224 2 a2225 2 ‘starti’ The ‘starti’ command does the equivalent of setting a temporary d2227 2 a2228 2 then invoking the ‘run’ command. For programs containing an elaboration phase, the ‘starti’ command will stop execution at the d2231 4 a2234 4 ‘set exec-wrapper WRAPPER’ ‘show exec-wrapper’ ‘unset exec-wrapper’ When ‘exec-wrapper’ is set, the specified wrapper is used to launch d2236 1 a2236 1 command of the form ‘exec WRAPPER PROGRAM’. Quoting is added to d2241 1 a2241 1 You can use any program that eventually calls ‘execve’ with its d2243 2 a2244 2 e.g. ‘env’ and ‘nohup’. Any Unix shell script ending with ‘exec "$@@"’ will also work. d2246 1 a2246 1 For example, you can use ‘env’ to pass an environment variable to d2256 4 a2259 4 ‘set startup-with-shell’ ‘set startup-with-shell on’ ‘set startup-with-shell off’ ‘show startup-with-shell’ d2261 1 a2261 1 target, GDB) uses it to start your program. Arguments of the ‘run’ d2273 1 a2273 1 ‘exec-wrapper’ crashed, not your program. Most often, this is d2275 2 a2276 2 initialization file--such as ‘.cshrc’ for C-shell, $‘.zshenv’ for the Z shell, or the file specified in the ‘BASH_ENV’ environment d2279 4 a2282 4 ‘set auto-connect-native-target’ ‘set auto-connect-native-target on’ ‘set auto-connect-native-target off’ ‘show auto-connect-native-target’ d2285 1 a2285 1 yet (e.g., with ‘target remote’), the ‘run’ command starts your d2289 1 a2289 1 with the ‘set auto-connect-native-target off’ command. d2291 2 a2292 2 If ‘on’, which is the default, and if the current inferior is not connected to a target already, the ‘run’ command automatically d2295 2 a2296 2 If ‘off’, and if the current inferior is not connected to a target already, the ‘run’ command fails with an error: d2302 1 a2302 1 always uses it with the ‘run’ command. d2305 1 a2305 1 the ‘target native’ command. For example, d2315 1 a2315 1 In case you connected explicitly to the ‘native’ target, GDB d2317 1 a2317 1 ‘run’ command. Use the ‘disconnect’ command to disconnect. d2320 2 a2321 2 ‘auto-connect-native-target’ setting: ‘attach’, ‘info proc’, ‘info os’. d2323 2 a2324 2 ‘set disable-randomization’ ‘set disable-randomization on’ d2336 1 a2336 1 ‘set disable-randomization off’ d2342 1 a2342 1 stand-alone programs. Use ‘set disable-randomization off’ to try d2366 2 a2367 2 a random address. You can build such executable using ‘gcc -fPIE -pie’. d2372 1 a2372 1 ‘show disable-randomization’ d2383 1 a2383 1 ‘run’ command. They are passed to a shell, which expands wildcard d2385 3 a2387 3 Your ‘SHELL’ environment variable (if it exists) specifies what shell GDB uses. If you do not define ‘SHELL’, GDB uses the default shell (‘/bin/sh’ on Unix). d2394 2 a2395 2 ‘run’ with no arguments uses the same arguments used by the previous ‘run’, or those set by the ‘set args’ command. d2397 1 a2397 1 ‘set args’ d2399 1 a2399 1 If ‘set args’ has no arguments, ‘run’ executes your program with no d2401 1 a2401 1 ‘set args’ before the next ‘run’ is the only way to run it again d2404 1 a2404 1 ‘show args’ d2413 1 a2413 1 The “environment” consists of a set of environment variables and their d2421 2 a2422 2 ‘path DIRECTORY’ Add DIRECTORY to the front of the ‘PATH’ environment variable (the d2424 1 a2424 1 The value of ‘PATH’ used by GDB does not change. You may specify d2426 1 a2426 1 system-dependent separator character (‘:’ on Unix, ‘;’ on MS-DOS d2430 1 a2430 1 You can use the string ‘$cwd’ to refer to whatever is the current d2432 2 a2433 2 ‘.’ instead, it refers to the directory where you executed the ‘path’ command. GDB replaces ‘.’ in the DIRECTORY argument (with d2436 2 a2437 2 ‘show paths’ Display the list of search paths for executables (the ‘PATH’ d2440 1 a2440 1 ‘show environment [VARNAME]’ d2444 1 a2444 1 program. You can abbreviate ‘environment’ as ‘env’. d2446 1 a2446 1 ‘set environment VARNAME [=VALUE]’ d2459 1 a2459 1 named ‘foo’. (The spaces around ‘=’ are used for clarity here; d2463 3 a2465 3 also inherits the environment set with ‘set environment’. If necessary, you can avoid that by using the ‘env’ program as a wrapper instead of using ‘set environment’. *Note set d2469 1 a2469 1 to ‘gdbserver’ to be used when starting the remote inferior. *note d2472 1 a2472 1 ‘unset environment VARNAME’ d2474 2 a2475 2 program. This is different from ‘set env VARNAME =’; ‘unset environment’ removes the variable from the environment, rather than d2479 1 a2479 1 ‘gdbserver’ when starting the remote inferior. *note d2483 5 a2487 5 indicated by your ‘SHELL’ environment variable if it exists (or ‘/bin/sh’ if not). If your ‘SHELL’ variable names a shell that runs an initialization file when started non-interactively--such as ‘.cshrc’ for C-shell, $‘.zshenv’ for the Z shell, or the file specified in the ‘BASH_ENV’ environment variable for BASH--any variables you set in that d2489 2 a2490 2 variables to files that are only run when you sign on, such as ‘.login’ or ‘.profile’. d2498 3 a2500 3 Each time you start your program with ‘run’, the inferior will be initialized with the current working directory specified by the ‘set cwd’ command. If no directory has been specified by this command, then d2505 1 a2505 1 ‘set cwd [DIRECTORY]’ d2507 1 a2507 1 ‘glob’-expanded in order to resolve tildes (‘~’). If no argument d2511 4 a2514 4 inferior. The ‘~’ in DIRECTORY is a short for the “home directory”, usually pointed to by the ‘HOME’ environment variable. On MS-Windows, if ‘HOME’ is not defined, GDB uses the concatenation of ‘HOMEDRIVE’ and ‘HOMEPATH’ as fallback. d2517 1 a2517 1 ‘cd’ command. *Note cd command::. d2519 1 a2519 1 ‘show cwd’ d2521 1 a2521 1 specified by ‘set cwd’, then the default inferior's working d2524 1 a2524 1 ‘cd [DIRECTORY]’ d2526 1 a2526 1 DIRECTORY uses ‘'~'’. d2532 1 a2532 1 ‘pwd’ d2537 2 a2538 2 during its run). If you work on a system where GDB supports the ‘info proc’ command (*note Process Information::), you can use the ‘info proc’ d2553 1 a2553 1 ‘info terminal’ d2558 1 a2558 1 redirection with the ‘run’ command. For example, d2562 1 a2562 1 starts your program, diverting its output to the file ‘outfile’. d2565 2 a2566 2 is with the ‘tty’ command. This command accepts a file name as argument, and causes this file to be the default for future ‘run’ d2568 1 a2568 1 process, for future ‘run’ commands. For example, d2572 2 a2573 2 directs that processes started with subsequent ‘run’ commands default to do input and output on the terminal ‘/dev/ttyb’ and have that as their d2576 1 a2576 1 An explicit redirection in ‘run’ overrides the ‘tty’ command's effect d2580 1 a2580 1 When you use the ‘tty’ command or redirect input in the ‘run’ d2582 2 a2583 2 GDB still comes from your terminal. ‘tty’ is an alias for ‘set inferior-tty’. d2585 1 a2585 1 You can use the ‘show inferior-tty’ command to tell GDB to display d2589 1 a2589 1 ‘set inferior-tty [ TTY ]’ d2594 1 a2594 1 ‘show inferior-tty’ d2603 1 a2603 1 ‘attach PROCESS-ID’ d2605 1 a2605 1 outside GDB. (‘info files’ shows your active targets.) The d2607 2 a2608 2 the PROCESS-ID of a Unix process is with the ‘ps’ utility, or with the ‘jobs -l’ shell command. d2610 1 a2610 1 ‘attach’ does not repeat if you press a second time after d2613 2 a2614 2 To use ‘attach’, your program must be running in an environment which supports processes; for example, ‘attach’ does not work for programs on d2618 1 a2618 1 When you use ‘attach’, the debugger finds the program running in the d2622 1 a2622 1 ‘file’ command to load the program. *Note Commands to Specify Files: d2627 1 a2627 1 by GDB, the option ‘exec-file-mismatch’ specifies how to handle the d2631 1 a2631 1 ‘set exec-file-mismatch ‘ask|warn|off’’ d2635 3 a2637 3 If ‘ask’, the default, display a warning and ask the user whether to load the process executable file; if ‘warn’, just display a warning; if ‘off’, don't attempt to detect a mismatch. If the user d2641 2 a2642 2 ‘show exec-file-mismatch’ Show the current value of ‘exec-file-mismatch’. d2647 1 a2647 1 processes with ‘run’. You can insert breakpoints; you can step and d2649 1 a2649 1 continue running, you may use the ‘continue’ command after attaching GDB d2652 1 a2652 1 ‘detach’ d2654 2 a2655 2 the ‘detach’ command to release it from GDB control. Detaching the process continues its execution. After the ‘detach’ command, that d2657 2 a2658 2 are ready to ‘attach’ another process or start one with ‘run’. ‘detach’ does not repeat if you press again after executing d2662 1 a2662 1 process. If you use the ‘run’ command, you kill that process. By d2665 1 a2665 1 ‘set confirm’ command (*note Optional Warnings and Messages: d2674 1 a2674 1 ‘kill’ d2682 1 a2682 1 while you have breakpoints set on it inside GDB. You can use the ‘kill’ d2686 1 a2686 1 The ‘kill’ command is also useful if you wish to recompile and relink d2689 1 a2689 1 you next type ‘run’, GDB notices that the file has changed, and reads d2709 1 a2709 1 called an “inferior”. An inferior typically corresponds to a process, d2718 2 a2719 2 The commands ‘info inferiors’ and ‘info connections’, which will be introduced below, accept a space-separated “ID list” as their argument d2721 4 a2724 4 be either a single non-negative number, like ‘5’, or an ascending range of such numbers, like ‘5-7’. A list can consist of any combination of such elements, even duplicates or overlapping ranges are valid. E.g. ‘1 4-6 5 4-4’ or ‘1 2 4-7’. d2726 1 a2726 1 To find out what inferiors exist at any moment, use ‘info inferiors’: d2728 1 a2728 1 ‘info inferiors’ d2745 1 a2745 1 An asterisk ‘*’ preceding the GDB inferior number indicates the d2755 1 a2755 1 To get information about the current inferior, use ‘inferior’: d2757 1 a2757 1 ‘inferior’ d2766 1 a2766 1 ‘info connections’: d2768 1 a2768 1 ‘info connections’ d2782 1 a2782 1 An asterisk ‘*’ preceding the connection number indicates the d2793 1 a2793 1 To switch focus between inferiors, use the ‘inferior’ command: d2795 1 a2795 1 ‘inferior INFNO’ d2798 1 a2798 1 field of the ‘info inferiors’ display. d2800 1 a2800 1 The debugger convenience variable ‘$_inferior’ contains the number of d2807 1 a2807 1 ‘add-inferior’ and ‘clone-inferior’ commands. On some systems GDB can d2809 2 a2810 2 ‘fork’ and ‘exec’. To remove inferiors from the debugging session use the ‘remove-inferiors’ command. d2812 1 a2812 1 ‘add-inferior [ -copies N ] [ -exec EXECUTABLE ] [-no-connection ]’ d2816 1 a2816 1 assigned to the inferior at any time by using the ‘file’ command d2821 6 a2826 6 inferior was connected to ‘gdbserver’ with ‘target remote’, then the new inferior will be connected to the same ‘gdbserver’ instance. The ‘-no-connection’ option starts the new inferior with no connection yet. You can then for example use the ‘target remote’ command to connect to some other ‘gdbserver’ instance, use ‘run’ to spawn a local program, etc. d2828 1 a2828 1 ‘clone-inferior [ -copies N ] [ INFNO ]’ d2834 1 a2834 1 variables using the ‘set environment’ and ‘unset environment’ d2851 1 a2851 1 ‘remove-inferiors INFNO...’ d2854 1 a2854 1 use the ‘kill’ or ‘detach’ command first. d2858 2 a2859 2 ‘detach inferior’ command (allowing it to run independently), or kill it using the ‘kill inferiors’ command: d2861 1 a2861 1 ‘detach inferior INFNO...’ d2864 2 a2865 2 the list of inferiors shown by ‘info inferiors’, but its Description will show ‘’. d2867 1 a2867 1 ‘kill inferiors INFNO...’ d2870 2 a2871 2 of inferiors shown by ‘info inferiors’, but its Description will show ‘’. d2873 4 a2876 4 After the successful completion of a command such as ‘detach’, ‘detach inferiors’, ‘kill’ or ‘kill inferiors’, or after a normal process exit, the inferior is still valid and listed with ‘info inferiors’, ready to be restarted. d2879 1 a2879 1 use ‘set print inferior-events’: d2881 4 a2884 4 ‘set print inferior-events’ ‘set print inferior-events on’ ‘set print inferior-events off’ The ‘set print inferior-events’ command allows you to enable or d2889 1 a2889 1 ‘show print inferior-events’ d2894 2 a2895 2 single program: e.g., ‘print myglobal’ will simply display the value of ‘myglobal’ in the current inferior. d2899 1 a2899 1 debug session. You can do that with the ‘maint info program-spaces’ d2902 1 a2902 1 ‘maint info program-spaces’ d2910 1 a2910 1 e.g., the ‘file’ command. d2913 1 a2913 1 e.g., the ‘core-file’ command. d2915 1 a2915 1 An asterisk ‘*’ preceding the GDB program space number indicates d2928 2 a2929 2 Here we can see that no inferior is running the program ‘hello’, while ‘process 21561’ is running the program ‘goodbye’. On some d2932 1 a2932 1 both the parent and child processes of a ‘vfork’ call. For d2941 1 a2941 1 program space as a result of inferior 1 having executed a ‘vfork’ d2957 2 a2958 2 ‘break LOCSPEC inferior INFERIOR-ID’ ‘break LOCSPEC inferior INFERIOR-ID if ...’ d2962 1 a2962 1 Use the qualifier ‘inferior INFERIOR-ID’ with a breakpoint command d2966 1 a2966 1 column of the ‘info inferiors’ output. d2968 1 a2968 1 If you do not specify ‘inferior INFERIOR-ID’ when you set a d2972 2 a2973 2 You can use the ‘inferior’ qualifier on conditional breakpoints as well; in this case, place ‘inferior INFERIOR-ID’ before or after d2986 1 a2986 1 Tasks::); using more than one of the ‘inferior’, ‘thread’, or ‘task’ d2996 1 a2996 1 program may have more than one “thread” of execution. The precise d3006 4 a3009 4 • automatic notification of new threads • ‘thread THREAD-ID’, a command to switch among threads • ‘info threads’, a command to inquire about existing threads • ‘thread apply [THREAD-ID-LIST | all] ARGS’, a command to apply a d3011 2 a3012 2 • thread-specific breakpoints • ‘set print thread-events’, which controls printing of messages on d3014 2 a3015 2 • ‘set libthread-db-search-path PATH’, which lets the user specify which ‘libthread_db’ to use if the default choice isn't compatible d3021 1 a3021 1 “current thread”. Debugging commands show program information from the d3026 1 a3026 1 ‘[New SYSTAG]’, where SYSTAG is a thread identifier whose form varies d3033 1 a3033 1 SYSTAG is simply something like ‘process 368’, with no further d3042 1 a3042 1 INFERIOR-NUM.THREAD-NUM syntax, also known as “qualified thread ID”, d3044 1 a3044 1 thread number of the given inferior. For example, thread ‘2.3’ refers d3046 1 a3046 1 ‘thread 3’), then GDB infers you're referring to a thread of the current d3054 1 a3054 1 Some commands accept a space-separated “thread ID list” as argument. d3057 3 a3059 3 1. A thread ID as shown in the first field of the ‘info threads’ display, with or without an inferior qualifier. E.g., ‘2.1’ or ‘1’. d3062 2 a3063 2 qualifier, as in INF.THR1-THR2 or THR1-THR2. E.g., ‘1.2-4’ or ‘2-4’. d3066 1 a3066 1 without an inferior qualifier, as in INF.‘*’ (e.g., ‘1.*’) or ‘*’. d3072 1 a3072 1 thread with ID 7.1, the thread list ‘1 2-3 4.5 6.7-9 7.*’ includes d3075 1 a3075 1 qualified form, the same as ‘1.1 1.2 1.3 4.5 6.7 6.8 6.9 7.1’. d3078 1 a3078 1 a unique _global_ number, also known as “global thread ID”, a single d3087 1 a3087 1 The debugger convenience variables ‘$_thread’ and ‘$_gthread’ d3091 1 a3091 1 forth. The convenience variable ‘$_inferior_thread_count’ contains the d3098 1 a3098 1 ‘$_inferior_thread_count’ could return a different value each time it is d3111 1 a3111 1 ‘info threads [-gid] [THREAD-ID-LIST]’ d3122 1 a3122 1 2. the global thread number assigned by GDB, if the ‘-gid’ option d3128 1 a3128 1 named by the user (see ‘thread name’, below), or, in some d3133 1 a3133 1 An asterisk ‘*’ to the left of the GDB thread number indicates the d3149 1 a3149 1 If you specify the ‘-gid’ option, GDB displays a column indicating d3162 1 a3162 1 ‘maint info sol-threads’ d3165 1 a3165 1 ‘thread THREAD-ID’ d3168 2 a3169 2 ‘info threads’ display, with or without an inferior qualifier (e.g., ‘2.1’ or ‘1’). d3179 2 a3180 2 As with the ‘[New ...]’ message, the form of the text after ‘Switching to’ depends on your system's conventions for identifying d3183 2 a3184 2 ‘thread apply [THREAD-ID-LIST | all [-ascending]] [FLAG]... COMMAND’ The ‘thread apply’ command allows you to apply the named COMMAND to d3187 4 a3190 4 specify ‘all’ to apply to all threads. To apply a command to all threads in descending order, type ‘thread apply all COMMAND’. To apply a command to all threads in ascending order, type ‘thread apply all -ascending COMMAND’. d3194 3 a3196 3 with a ‘-’ directly followed by one letter in ‘qcs’. If several flags are provided, they must be given individually, such as ‘-c -q’. d3200 1 a3200 1 COMMAND will abort ‘thread apply’. The following flags can be used d3203 6 a3208 6 ‘-c’ The flag ‘-c’, which stands for ‘continue’, causes any errors in COMMAND to be displayed, and the execution of ‘thread apply’ then continues. ‘-s’ The flag ‘-s’, which stands for ‘silent’, causes any errors or d3212 2 a3213 2 ‘-q’ The flag ‘-q’ (‘quiet’) disables printing the thread d3216 1 a3216 1 Flags ‘-c’ and ‘-s’ cannot be used together. d3218 2 a3219 2 ‘taas [OPTION]... COMMAND’ Shortcut for ‘thread apply all -s [OPTION]... COMMAND’. Applies d3222 2 a3223 2 The ‘taas’ command accepts the same options as the ‘thread apply all’ command. *Note thread apply all::. d3225 8 a3232 8 ‘tfaas [OPTION]... COMMAND’ Shortcut for ‘thread apply all -s -- frame apply all -s [OPTION]... COMMAND’. Applies COMMAND on all frames of all threads, ignoring errors and empty output. Note that the flag ‘-s’ is specified twice: The first ‘-s’ ensures that ‘thread apply’ only shows the thread information of the threads for which ‘frame apply’ produces some output. The second ‘-s’ is needed to ensure that ‘frame apply’ shows the frame information of a frame only if the COMMAND d3240 1 a3240 1 The ‘tfaas’ command accepts the same options as the ‘frame apply’ d3243 1 a3243 1 ‘thread name [NAME]’ d3246 1 a3246 1 name appears in the ‘info threads’ display. d3250 1 a3250 1 specified with ‘thread name’ will override the system-give name, d3254 1 a3254 1 ‘thread find [REGEXP]’ d3258 1 a3258 1 As well as being the complement to the ‘thread name’ command, this d3268 4 a3271 4 ‘set print thread-events’ ‘set print thread-events on’ ‘set print thread-events off’ The ‘set print thread-events’ command allows you to enable or d3278 1 a3278 1 ‘show print thread-events’ d3289 1 a3289 1 ‘set libthread-db-search-path [PATH]’ d3291 4 a3294 4 directories GDB will use to search for ‘libthread_db’. If you omit PATH, ‘libthread-db-search-path’ will be reset to its default value (‘$sdir:$pdir’ on GNU/Linux and Solaris systems). Internally, the default value comes from the ‘LIBTHREAD_DB_SEARCH_PATH’ macro. d3297 5 a3301 5 ‘libthread_db’ library to obtain information about threads in the inferior process. GDB will use ‘libthread-db-search-path’ to find ‘libthread_db’. GDB also consults first if inferior specific thread debugging library loading is enabled by ‘set auto-load libthread-db’ (*note libthread_db.so.1 file::). d3303 1 a3303 1 A special entry ‘$sdir’ for ‘libthread-db-search-path’ refers to d3305 2 a3306 2 loading shared libraries. The ‘$sdir’ entry is the only kind not needing to be enabled by ‘set auto-load libthread-db’ (*note d3309 2 a3310 2 A special entry ‘$pdir’ for ‘libthread-db-search-path’ refers to the directory from which ‘libpthread’ was loaded in the inferior d3313 1 a3313 1 For any ‘libthread_db’ library GDB finds in above directories, GDB d3316 3 a3318 3 mismatch between ‘libthread_db’ and ‘libpthread’), GDB will unload ‘libthread_db’, and continue with the next directory. If none of ‘libthread_db’ libraries initialize successfully, GDB will issue a d3321 1 a3321 1 Setting ‘libthread-db-search-path’ is currently implemented only on d3324 1 a3324 1 ‘show libthread-db-search-path’ d3327 8 a3334 8 ‘set debug libthread-db’ ‘show debug libthread-db’ Turns on or off display of ‘libthread_db’-related events. Use ‘1’ to enable, ‘0’ to disable. ‘set debug threads [on|off]’ ‘show debug threads’ When ‘on’ GDB will print additional messages when threads are d3344 1 a3344 1 create additional processes using the ‘fork’ function. When a program d3347 1 a3347 1 which the child then executes, the child will get a ‘SIGTRAP’ signal d3351 1 a3351 1 which isn't too painful. Put a call to ‘sleep’ in the code which the d3355 1 a3355 1 child. While the child is sleeping, use the ‘ps’ program to get its d3362 1 a3362 1 create additional processes using the ‘fork’ or ‘vfork’ functions. On d3367 2 a3368 2 connected to ‘gdbserver’ in either ‘target remote’ mode or ‘target extended-remote’ mode. d3374 1 a3374 1 process, use the command ‘set follow-fork-mode’. d3376 3 a3378 3 ‘set follow-fork-mode MODE’ Set the debugger response to a program call of ‘fork’ or ‘vfork’. A call to ‘fork’ or ‘vfork’ creates a new process. The MODE d3381 1 a3381 1 ‘parent’ d3385 1 a3385 1 ‘child’ d3389 2 a3390 2 ‘show follow-fork-mode’ Display the current debugger response to a ‘fork’ or ‘vfork’ call. d3393 1 a3393 1 use the command ‘set detach-on-fork’. d3395 1 a3395 1 ‘set detach-on-fork MODE’ d3399 1 a3399 1 ‘on’ d3401 1 a3401 1 of ‘follow-fork-mode’) will be detached and allowed to run d3404 1 a3404 1 ‘off’ d3407 1 a3407 1 ‘follow-fork-mode’) is debugged as usual, while the other is d3410 1 a3410 1 ‘show detach-on-fork’ d3413 1 a3413 1 If you choose to set ‘detach-on-fork’ mode off, then GDB will retain d3416 2 a3417 2 ‘info inferiors’ command, and switch from one fork to another by using the ‘inferior’ command (*note Debugging Multiple Inferiors Connections d3421 2 a3422 2 from it by using the ‘detach inferiors’ command (allowing it to run independently), or kill it using the ‘kill inferiors’ command. *Note d3426 4 a3429 4 If you ask to debug a child process and a ‘vfork’ is followed by an ‘exec’, GDB executes the new target up to the first breakpoint in the new target. If you have a breakpoint set on ‘main’ in your original program, the breakpoint will also be set on the child process's ‘main’. d3431 2 a3432 2 On some systems, when a child process is spawned by ‘vfork’, you cannot debug the child or parent until an ‘exec’ call completes. d3434 2 a3435 2 If you issue a ‘run’ command to GDB after an ‘exec’ call executes, the new target restarts. To restart the parent process, use the ‘file’ d3437 1 a3437 1 after an ‘exec’ call executes, GDB discards the symbols of the previous d3439 1 a3439 1 ‘set follow-exec-mode’ command. d3441 1 a3441 1 ‘set follow-exec-mode MODE’ d3443 1 a3443 1 Set debugger response to a program call of ‘exec’. An ‘exec’ call d3446 1 a3446 1 ‘follow-exec-mode’ can be: d3448 1 a3448 1 ‘new’ d3451 1 a3451 1 ‘exec’ call can be restarted afterwards by restarting the d3468 1 a3468 1 ‘same’ d3471 3 a3473 3 the inferior. Restarting the inferior after the ‘exec’ call, with e.g., the ‘run’ command, restarts the executable the process was running after the ‘exec’ call. This is the d3488 2 a3489 2 ‘follow-exec-mode’ is supported in native mode and ‘target extended-remote’ mode. d3491 2 a3492 2 You can use the ‘catch’ command to make GDB stop whenever a ‘fork’, ‘vfork’, or ‘exec’ call is made. *Note Setting Catchpoints: Set d3501 2 a3502 2 On certain operating systems(1), GDB is able to save a “snapshot” of a program's state, called a “checkpoint”, and come back to it later. d3505 1 a3505 1 happened in the program since the ‘checkpoint’ was saved. This includes d3519 1 a3519 1 To use the ‘checkpoint’/‘restart’ method of debugging: d3521 1 a3521 1 ‘checkpoint’ d3523 1 a3523 1 The ‘checkpoint’ command takes no arguments, but each checkpoint is d3526 1 a3526 1 ‘info checkpoints’ d3531 4 a3534 4 ‘Checkpoint ID’ ‘Process ID’ ‘Code Address’ ‘Source line, or label’ d3536 1 a3536 1 ‘restart CHECKPOINT-ID’ d3548 1 a3548 1 ‘delete checkpoint CHECKPOINT-ID’ d3608 1 a3608 1 as ‘step’. You may then examine and change variables, set new d3614 1 a3614 1 ‘info program’ d3634 1 a3634 1 A “breakpoint” makes your program stop whenever a certain point in the d3637 1 a3637 1 breakpoints with the ‘break’ command and its variants (*note Setting d3645 1 a3645 1 A “watchpoint” is a special breakpoint that stops your program when d3648 2 a3649 2 by operators, such as ‘a + b’. This is sometimes called “data breakpoints”. You must use a different command to set watchpoints d3658 1 a3658 1 A “catchpoint” is another special breakpoint that stops your program d3664 1 a3664 1 ‘handle’ command; see *note Signals: Signals.) d3670 1 a3670 1 want to change. Each breakpoint may be “enabled” or “disabled”; if d3675 1 a3675 1 number, like ‘5’, or a range of such numbers, like ‘5-7’. When a d3700 2 a3701 2 Breakpoints are set with the ‘break’ command (abbreviated ‘b’). The debugger convenience variable ‘$bpnum’ records the number of the d3719 1 a3719 1 ‘$_hit_bpnum’ and ‘$_hit_locno’ are respectively set to the number of d3730 2 a3731 2 Note that ‘$_hit_bpnum’ and ‘$bpnum’ are not equivalent: ‘$_hit_bpnum’ is set to the breakpoint number last hit, while ‘$bpnum’ d3735 1 a3735 1 ‘$_hit_locno’ is set to 1: d3744 1 a3744 1 The ‘$_hit_bpnum’ and ‘$_hit_locno’ variables can typically be used d3747 5 a3751 5 can disable completely the encountered breakpoint using ‘disable $_hit_bpnum’ or disable the specific encountered breakpoint location using ‘disable $_hit_bpnum.$_hit_locno’. If a breakpoint has only one location, ‘$_hit_locno’ is set to 1 and the commands ‘disable $_hit_bpnum’ and ‘disable $_hit_bpnum.$_hit_locno’ both disable the d3759 1 a3759 1 ‘break LOCSPEC’ d3779 2 a3780 2 ‘break’ When called without any arguments, ‘break’ sets a breakpoint at the d3784 3 a3786 3 to that frame. This is similar to the effect of a ‘finish’ command in the frame inside the selected frame--except that ‘finish’ does not leave an active breakpoint. If you use ‘break’ without an d3796 1 a3796 1 ‘break ... if COND’ d3799 1 a3799 1 nonzero--that is, if COND evaluates as true. ‘...’ stands for one d3818 1 a3818 1 an uppercase ‘N’ in the output of the ‘info breakpoints’ command: d3831 1 a3831 1 breakpoint. For example, if variable ‘foo’ is an undefined d3837 1 a3837 1 ‘break ... -force-condition if COND’ d3841 1 a3841 1 cases, by using the ‘-force-condition’ keyword before ‘if’, GDB can d3857 1 a3857 1 valid, the ‘-force-condition’ keyword has no effect. d3859 1 a3859 1 ‘tbreak ARGS’ d3861 1 a3861 1 as for the ‘break’ command, and the breakpoint is set in the same d3866 1 a3866 1 ‘hbreak ARGS’ d3868 1 a3868 1 the ‘break’ command and the breakpoint is set in the same way, but d3885 1 a3885 1 ‘thbreak ARGS’ d3887 2 a3888 2 ARGS are the same as for the ‘hbreak’ command and the breakpoint is set in the same way. However, like the ‘tbreak’ command, the d3890 1 a3890 1 program stops there. Also, like the ‘hbreak’ command, the d3895 1 a3895 1 ‘rbreak REGEX’ d3900 1 a3900 1 with the ‘break’ command. You can delete them, disable them, or d3904 2 a3905 2 print the list of all breakpoints it sets according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language d3911 6 a3916 6 tools like ‘grep’. Note that this is different from the syntax used by shells, so for instance ‘foo*’ matches all functions that include an ‘fo’ followed by zero or more ‘o’s. There is an implicit ‘.*’ leading and trailing the regular expression you supply, so to match only functions that begin with ‘foo’, use ‘^foo’. d3918 1 a3918 1 When debugging C++ programs, ‘rbreak’ is useful for setting d3922 1 a3922 1 The ‘rbreak’ command can be used to set breakpoints in *all* the d3927 2 a3928 2 ‘rbreak FILE:REGEX’ If ‘rbreak’ is called with a filename qualification, it limits the d3938 2 a3939 2 ‘info breakpoints [LIST...]’ ‘info break [LIST...]’ d3953 1 a3953 1 Enabled breakpoints are marked with ‘y’. ‘n’ marks d3958 1 a3958 1 field will contain ‘’. Such breakpoint won't fire d3961 1 a3961 1 with several locations will have ‘’ in this d3973 1 a3973 1 then the condition is evaluated by the target. The ‘info break’ d3984 3 a3986 3 ‘info break’ with a breakpoint number N as argument lists only that breakpoint. The convenience variable ‘$_’ and the default examining-address for the ‘x’ command are set to the address of the d3989 1 a3989 1 ‘info break’ displays a count of the number of times the breakpoint d3991 1 a3991 1 ‘ignore’ command. You can ignore a large number of breakpoint d3997 2 a3998 2 For a breakpoints with an enable count (xref) greater than 1, ‘info break’ also displays that count. d4011 1 a4011 1 for each code location. The header row has ‘’ in the address d4027 2 a4028 2 passing BREAKPOINT-NUMBER.LOCATION-NUMBER as argument to the ‘enable’ and ‘disable’ commands. It's also possible to ‘enable’ and ‘disable’ a d4031 1 a4031 1 ‘BREAKPOINT-NUMBER.LOCATION-NUMBER1-LOCATION-NUMBER2’, in which case GDB d4037 1 a4037 1 won't trigger a break, and are denoted by ‘y-’ in the ‘Enb’ column. For d4055 1 a4055 1 “pending breakpoint”--breakpoint whose address is not yet resolved. d4074 1 a4074 1 when the ‘break’ command cannot resolve the location spec to any code d4077 1 a4077 1 ‘set breakpoint pending auto’ d4082 1 a4082 1 ‘set breakpoint pending on’ d4086 1 a4086 1 ‘set breakpoint pending off’ d4092 1 a4092 1 ‘show breakpoint pending’ d4095 1 a4095 1 The settings above only affect the ‘break’ command and its variants. d4102 2 a4103 2 with the ‘break’ command as well as to internal breakpoints set by commands like ‘next’ and ‘finish’. For breakpoints set with ‘hbreak’, d4108 1 a4108 1 ‘set breakpoint auto-hw on’ d4113 1 a4113 1 ‘set breakpoint auto-hw off’ d4128 1 a4128 1 ‘set breakpoint always-inserted off’ d4133 1 a4133 1 ‘set breakpoint always-inserted on’ d4149 1 a4149 1 ‘set breakpoint condition-evaluation host’ d4155 1 a4155 1 ‘set breakpoint condition-evaluation target’ d4169 1 a4169 1 ‘set breakpoint condition-evaluation auto’ d4178 4 a4181 4 purposes, such as proper handling of ‘longjmp’ (in C programs). These internal breakpoints are assigned negative numbers, starting with ‘-1’; ‘info breakpoints’ does not display them. You can see these breakpoints with the GDB maintenance command ‘maint info breakpoints’ (*note maint d4192 1 a4192 1 this may happen. (This is sometimes called a “data breakpoint”.) The d4196 1 a4196 1 • A reference to the value of a single variable. d4198 3 a4200 3 • An address cast to an appropriate data type. For example, ‘*(int *)0x12345678’ will watch a 4-byte region at the specified address (assuming an ‘int’ occupies 4 bytes). d4202 1 a4202 1 • An arbitrarily complex expression, such as ‘a*b + c/d’. The d4208 2 a4209 2 ‘*global_ptr’ before ‘global_ptr’ is initialized. GDB will stop when your program sets ‘global_ptr’ and the expression produces a valid d4211 2 a4212 2 a variable (e.g. if the memory pointed to by ‘*global_ptr’ becomes readable as the result of a ‘malloc’ call), GDB may not stop until the d4226 1 a4226 1 ‘watch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE] [task TASK-ID]’ d4234 1 a4234 1 If the command includes a ‘[thread THREAD-ID]’ argument, GDB breaks d4240 1 a4240 1 Similarly, if the ‘task’ argument is given, then the watchpoint d4244 1 a4244 1 (see below). The ‘-location’ argument tells GDB to instead watch d4251 1 a4251 1 The ‘[mask MASKVALUE]’ argument allows creation of masked d4254 1 a4254 1 Embedded::.) A “masked watchpoint” specifies a mask in addition to d4261 1 a4261 1 ‘mask’ argument implies ‘-location’. Examples: d4266 1 a4266 1 ‘rwatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]’ d4270 1 a4270 1 ‘awatch [-l|-location] EXPR [thread THREAD-ID] [mask MASKVALUE]’ d4274 1 a4274 1 ‘info watchpoints [LIST...]’ d4276 1 a4276 1 ‘info break’ (*note Set Breaks::). d4288 1 a4288 1 GDB sets a “hardware watchpoint” if possible. Hardware watchpoints d4295 2 a4296 2 You can force GDB to use only software watchpoints with the ‘set can-use-hw-watchpoints 0’ command. With this variable set to zero, GDB d4299 1 a4299 1 were set _before_ setting ‘can-use-hw-watchpoints’ to zero will still d4302 1 a4302 1 ‘set can-use-hw-watchpoints’ d4305 1 a4305 1 ‘show can-use-hw-watchpoints’ d4312 1 a4312 1 When you issue the ‘watch’ command, GDB reports d4318 1 a4318 1 Currently, the ‘awatch’ and ‘rwatch’ commands can only set hardware d4323 1 a4323 1 ‘awatch’ or ‘rwatch’ command, it will print a message like this: d4352 1 a4352 1 If you call a function interactively using ‘print’ or ‘call’, any d4363 1 a4363 1 doing that would be to set a code breakpoint at the entry to the ‘main’ d4387 1 a4387 1 You can use “catchpoints” to cause the debugger to stop for certain d4389 1 a4389 1 shared library. Use the ‘catch’ command to set a catchpoint. d4391 1 a4391 1 ‘catch EVENT’ d4394 3 a4396 3 ‘throw [REGEXP]’ ‘rethrow [REGEXP]’ ‘catch [REGEXP]’ d4402 1 a4402 1 The convenience variable ‘$_exception’ is available at an d4409 2 a4410 2 • The support for these commands is system-dependent. Currently, only systems using the ‘gnu-v3’ C++ ABI (*note d4413 1 a4413 1 • The regular expression feature and the ‘$_exception’ d4415 1 a4415 1 probes in ‘libstdc++’. If these probes are not present, d4421 1 a4421 1 • The ‘$_exception’ convenience variable is only valid at d4425 1 a4425 1 • When an exception-related catchpoint is hit, GDB stops at d4427 2 a4428 2 exception support for C++, usually ‘libstdc++’. You can use ‘up’ (*note Selection::) to get to your code. d4430 1 a4430 1 • If you call a function interactively, GDB normally d4440 1 a4440 1 this with ‘set unwind-on-terminating-exception’. d4442 1 a4442 1 • You cannot raise an exception interactively. d4444 1 a4444 1 • You cannot install an exception handler interactively. d4446 1 a4446 1 ‘exception [NAME]’ d4448 2 a4449 2 specified at the end of the command (eg ‘catch exception Program_Error’), the debugger will stop only when this d4459 3 a4461 3 ‘Constraint_Error’ is defined in package ‘Pck’, then the command to use to catch such exceptions is ‘catch exception Pck.Constraint_Error’. d4463 1 a4463 1 The convenience variable ‘$_ada_exception’ holds the address d4467 1 a4467 1 ‘exception unhandled’ d4469 2 a4470 2 program. The convenience variable ‘$_ada_exception’ is set as for ‘catch exception’. d4472 1 a4472 1 ‘handlers [NAME]’ d4474 2 a4475 2 specified at the end of the command (eg ‘catch handlers Program_Error’), the debugger will stop only when this d4485 3 a4487 3 ‘Constraint_Error’ is defined in package ‘Pck’, then the command to use to catch such exceptions handling is ‘catch handlers Pck.Constraint_Error’. d4489 2 a4490 2 The convenience variable ‘$_ada_exception’ is set as for ‘catch exception’. d4492 1 a4492 1 ‘assert’ d4494 1 a4494 1 ‘$_ada_exception’ is _not_ set by this catchpoint. d4496 2 a4497 2 ‘exec’ A call to ‘exec’. d4499 3 a4501 3 ‘syscall’ ‘syscall [NAME | NUMBER | group:GROUPNAME | g:GROUPNAME] ...’ A call to or return from a system call, a.k.a. “syscall”. A d4512 1 a4512 1 syscall names on ‘/usr/include/asm/unistd.h’. d4529 1 a4529 1 once using the ‘group:’ syntax (‘g:’ is a shorter equivalent). d4532 1 a4532 1 ‘group:network’ to ‘catch syscall’. Note that not all syscall d4613 1 a4613 1 If you configure GDB using the ‘--without-expat’ option, it d4641 2 a4642 2 ‘fork’ A call to ‘fork’. d4644 2 a4645 2 ‘vfork’ A call to ‘vfork’. d4647 2 a4648 2 ‘load [REGEXP]’ ‘unload [REGEXP]’ d4653 1 a4653 1 ‘signal [SIGNAL... | ‘all’]’ d4658 1 a4658 1 except ‘SIGTRAP’ and ‘SIGINT’. d4660 1 a4660 1 With the argument ‘all’, all signals, including those used by d4665 1 a4665 1 to ‘handle’ (*note Signals::). Only signals specified in this d4668 2 a4669 2 One reason that ‘catch signal’ can be more useful than ‘handle’ is that you can attach commands and conditions to the d4672 2 a4673 2 When a signal is caught by a catchpoint, the signal's ‘stop’ and ‘print’ settings, as specified by ‘handle’, are ignored. d4675 1 a4675 1 depends on the ‘pass’ setting; this can be changed in the d4678 1 a4678 1 ‘tcatch EVENT’ d4682 1 a4682 1 Use the ‘info break’ command to list the current catchpoints. d4692 1 a4692 1 to stop there. This is called “deleting” the breakpoint. A breakpoint d4695 2 a4696 2 With the ‘clear’ command you can delete breakpoints according to where they are in your program. With the ‘delete’ command you can d4705 1 a4705 1 ‘clear’ d4711 1 a4711 1 ‘clear LOCSPEC’ d4717 4 a4720 4 ‘LINENUM’ ‘FILENAME:LINENUM’ ‘-line LINENUM’ ‘-source FILENAME -line LINENUM’ d4727 1 a4727 1 ‘*ADDRESS’ d4731 2 a4732 2 ‘FUNCTION’ ‘-function FUNCTION’ d4740 1 a4740 1 ‘delete [breakpoints] [LIST...]’ d4744 2 a4745 2 catchpoints (GDB asks confirmation, unless you have ‘set confirm off’). You can abbreviate this command as ‘d’. d4754 1 a4754 1 prefer to “disable” it. This makes the breakpoint inoperative as if it d4756 1 a4756 1 that you can “enable” it again later. d4759 3 a4761 3 catchpoints with the ‘enable’ and ‘disable’ commands, optionally specifying one or more breakpoint numbers as arguments. Use ‘info break’ to print a list of all breakpoints, watchpoints, tracepoints, and d4770 4 a4773 4 • Enabled. The breakpoint stops your program. A breakpoint set with the ‘break’ command starts out in this state. • Disabled. The breakpoint has no effect on your program. • Enabled once. The breakpoint stops your program, but then becomes d4775 1 a4775 1 • Enabled for a count. The breakpoint stops your program for the d4777 1 a4777 1 • Enabled for deletion. The breakpoint stops your program, but d4779 1 a4779 1 breakpoint set with the ‘tbreak’ command starts out in this state. d4784 1 a4784 1 ‘disable [breakpoints] [LIST...]’ d4789 1 a4789 1 abbreviate ‘disable’ as ‘dis’. d4791 1 a4791 1 ‘enable [breakpoints] [LIST...]’ d4795 1 a4795 1 ‘enable [breakpoints] once LIST...’ d4799 1 a4799 1 ‘enable [breakpoints] count COUNT LIST...’ d4807 1 a4807 1 ‘enable [breakpoints] delete LIST...’ d4810 1 a4810 1 there. Breakpoints set by the ‘tbreak’ command start out in this d4813 1 a4813 1 Except for a breakpoint set with ‘tbreak’ (*note Setting Breakpoints: d4816 1 a4816 1 the commands above. (The command ‘until’ can set and delete a d4828 1 a4828 1 specified place. You can also specify a “condition” for a breakpoint. d4837 2 a4838 2 expressed by the condition ASSERT, you should set the condition ‘! ASSERT’ on the appropriate breakpoint. d4871 1 a4871 1 ‘if’ in the arguments to the ‘break’ command. *Note Setting d4873 1 a4873 1 ‘condition’ command. d4875 2 a4876 2 You can also use the ‘if’ keyword with the ‘watch’ command. The ‘catch’ command does not recognize the ‘if’ keyword; ‘condition’ is the d4879 1 a4879 1 ‘condition BNUM EXPRESSION’ d4883 1 a4883 1 is true (nonzero, in C). When you use ‘condition’, GDB checks d4892 2 a4893 2 ‘condition’ command (or a command that sets a breakpoint with a condition, like ‘break if ...’) is given, however. *Note d4896 2 a4897 2 ‘condition -force BNUM EXPRESSION’ When the ‘-force’ flag is used, define the condition even if d4899 2 a4900 2 BNUM. This is similar to the ‘-force-condition’ option of the ‘break’ command. d4902 1 a4902 1 ‘condition BNUM’ d4908 1 a4908 1 useful that there is a special way to do it, using the “ignore count” of d4917 1 a4917 1 ‘ignore BNUM COUNT’ d4926 1 a4926 1 When you use ‘continue’ to resume execution of your program from a d4928 1 a4928 1 to ‘continue’, rather than using ‘ignore’. *Note Continuing and d4936 1 a4936 1 such as ‘$foo-- <= 0’ using a debugger convenience variable that is d4954 3 a4956 3 ‘commands [LIST...]’ ‘... COMMAND-LIST ...’ ‘end’ d4959 1 a4959 1 just ‘end’ to terminate the commands. d4961 2 a4962 2 To remove all commands from a breakpoint, type ‘commands’ and follow it immediately with ‘end’; that is, give no commands. d4964 1 a4964 1 With no argument, ‘commands’ refers to the last breakpoint, d4967 1 a4967 1 single command, then the ‘commands’ will apply to all the d4969 1 a4969 1 by ‘rbreak’, and also applies when a single ‘break’ command creates d4976 1 a4976 1 Inside a command list, you can use the command ‘disable $_hit_bpnum’ d4979 2 a4980 2 If your breakpoint has several code locations, the command ‘disable $_hit_bpnum.$_hit_locno’ will disable the specific breakpoint code d4985 1 a4985 1 Simply use the ‘continue’ command, or ‘step’, or any other command that d4990 1 a4990 1 (even with a simple ‘next’ or ‘step’), you may encounter another d4994 1 a4994 1 If the first command you specify in a command list is ‘silent’, the d4998 1 a4998 1 see no sign that the breakpoint was reached. ‘silent’ is meaningful d5001 1 a5001 1 The commands ‘echo’, ‘output’, and ‘printf’ allow you to print d5006 1 a5006 1 the value of ‘x’ at entry to ‘foo’ whenever ‘x’ is positive. d5019 2 a5020 2 to any variables that need them. End with the ‘continue’ command so that your program does not stop, and start with the ‘silent’ command so d5036 1 a5036 1 The dynamic printf command ‘dprintf’ combines a breakpoint with d5038 1 a5038 1 inserting ‘printf’ calls into your program on-the-fly, without having to d5042 1 a5042 1 you can set the variable ‘dprintf-style’ for alternate handling. For d5044 1 a5044 1 ‘printf’ function. This has the advantage that the characters go to the d5056 1 a5056 1 ‘dprintf LOCSPEC,TEMPLATE,EXPRESSION[,EXPRESSION...]’ d5062 1 a5062 1 ‘set dprintf-style STYLE’ d5069 3 a5071 3 ‘gdb’ Handle the output using the GDB ‘printf’ command. When using this style, it is possible to use the ‘%V’ format specifier d5074 1 a5074 1 ‘call’ d5076 1 a5076 1 (normally ‘printf’). When using this style the supported d5081 2 a5082 2 the ‘printf’ function, however, GDB's ‘%V’ format specifier extension is not supported by ‘printf’. When using ‘call’ d5087 2 a5088 2 ‘agent’ Have the remote debugging agent (such as ‘gdbserver’) handle d5091 1 a5091 1 not support the ‘%V’ format specifier. d5093 4 a5096 4 ‘set dprintf-function FUNCTION’ Set the function to call if the dprintf style is ‘call’. By default its value is ‘printf’. You may set it to any expression that GDB can evaluate to a function, as per the ‘call’ command. d5098 1 a5098 1 ‘set dprintf-channel CHANNEL’ d5101 1 a5101 1 argument to the ‘dprintf-function’, in the manner of ‘fprintf’ and d5103 1 a5103 1 the first argument, in the manner of ‘printf’. d5105 2 a5106 2 As an example, if you wanted ‘dprintf’ output to go to a logfile that is a standard I/O stream assigned to the variable ‘mylog’, you d5120 1 a5120 1 Note that the ‘info break’ displays the dynamic printf commands as d5124 3 a5126 3 ‘set disconnected-dprintf on’ ‘set disconnected-dprintf off’ Choose whether ‘dprintf’ commands should continue to run if GDB has d5128 1 a5128 1 ‘dprintf-style’ is ‘agent’. d5130 2 a5131 2 ‘show disconnected-dprintf off’ Show the current choice for disconnected ‘dprintf’. d5146 1 a5146 1 To save breakpoint definitions to a file use the ‘save breakpoints’ d5149 1 a5149 1 ‘save breakpoints [FILENAME]’ d5151 1 a5151 1 their commands and ignore counts, into a file ‘FILENAME’ suitable d5154 1 a5154 1 To read the saved breakpoint definitions, use the ‘source’ command d5170 1 a5170 1 GDB supports “SDT” probes in the code. SDT stands for Statically d5177 2 a5178 2 • ‘SystemTap’ () SDT probes(1). ‘SystemTap’ probes are usable from assembly, C and C++ d5181 2 a5182 2 • ‘DTrace’ () USDT probes. ‘DTrace’ probes are usable from C and C++ languages. d5184 1 a5184 1 Some ‘SystemTap’ probes have an associated semaphore variable; for d5186 1 a5186 1 DTrace-style ‘.d’ file. If your probe has a semaphore, GDB will d5188 3 a5190 3 ‘-probe-stap’ notation. But, if you put a breakpoint at a probe's location by some other method (e.g., ‘break file:line’), then GDB will not automatically set the semaphore. ‘DTrace’ probes do not support d5193 2 a5194 2 You can examine the available static static probes using ‘info probes’, with optional arguments: d5196 3 a5198 3 ‘info probes [TYPE] [PROVIDER [NAME [OBJFILE]]]’ If given, TYPE is either ‘stap’ for listing ‘SystemTap’ probes or ‘dtrace’ for listing ‘DTrace’ probes. If omitted all probes are d5213 1 a5213 1 ‘info probes all’ d5218 2 a5219 2 handled. Some ‘DTrace’ probes can be enabled or disabled, but ‘SystemTap’ probes cannot be disabled. d5224 1 a5224 1 ‘enable probes [PROVIDER [NAME [OBJFILE]]]’ d5237 2 a5238 2 ‘disable probes [PROVIDER [NAME [OBJFILE]]]’ See the ‘enable probes’ command above for a description of the d5245 1 a5245 1 ‘$_probe_arg0’...‘$_probe_arg11’. In ‘SystemTap’ probes each probe d5247 1 a5247 1 In ‘DTrace’ probes types are preserved provided that they are recognized d5249 1 a5249 1 integer. The convenience variable ‘$_probe_argc’ holds the number of d5260 1 a5260 1 more information on how to add ‘SystemTap’ SDT probes in your d5341 2 a5342 2 “Continuing” means resuming program execution until your program completes normally. In contrast, “stepping” means executing just one d5347 1 a5347 1 to a signal, you may want to use ‘handle’, or use ‘signal 0’ to resume d5351 3 a5353 3 ‘continue [IGNORE-COUNT]’ ‘c [IGNORE-COUNT]’ ‘fg [IGNORE-COUNT]’ d5358 1 a5358 1 is like that of ‘ignore’ (*note Break Conditions: Conditions.). d5362 1 a5362 1 ‘continue’ is ignored. d5364 1 a5364 1 The synonyms ‘c’ and ‘fg’ (for “foreground”, as the debugged d5366 1 a5366 1 for convenience, and have exactly the same behavior as ‘continue’. d5368 1 a5368 1 To resume execution at a different place, you can use ‘return’ (*note d5370 1 a5370 1 function; or ‘jump’ (*note Continuing at a Different Address: Jumping.) d5380 1 a5380 1 ‘step’ d5383 1 a5383 1 is abbreviated ‘s’. d5385 1 a5385 1 _Warning:_ If you use the ‘step’ command while control is d5391 1 a5391 1 debugging information, use the ‘stepi’ command, described d5394 1 a5394 1 The ‘step’ command only stops at the first instruction of a source d5396 1 a5396 1 in ‘switch’ statements, ‘for’ loops, etc. ‘step’ continues to stop d5398 1 a5398 1 line. In other words, ‘step’ _steps inside_ any functions called d5401 1 a5401 1 Also, the ‘step’ command only enters a function if there is line d5403 2 a5404 2 ‘next’ command. This avoids problems when using ‘cc -gl’ on MIPS machines. Previously, ‘step’ entered subroutines if there was any d5407 2 a5408 2 ‘step COUNT’ Continue running as in ‘step’, but do so COUNT times. If a d5412 1 a5412 1 ‘next [COUNT]’ d5414 1 a5414 1 frame. This is similar to ‘step’, but function calls that appear d5417 2 a5418 2 stack level that was executing when you gave the ‘next’ command. This command is abbreviated ‘n’. d5420 1 a5420 1 An argument COUNT is a repeat count, as for ‘step’. d5422 1 a5422 1 The ‘next’ command only stops at the first instruction of a source d5424 1 a5424 1 ‘switch’ statements, ‘for’ loops, etc. d5426 3 a5428 3 ‘set step-mode’ ‘set step-mode on’ The ‘set step-mode on’ command causes the ‘step’ command to stop at d5436 2 a5437 2 ‘set step-mode off’ Causes the ‘step’ command to step over any functions which contains d5440 1 a5440 1 ‘show step-mode’ d5444 1 a5444 1 ‘finish’ d5447 1 a5447 1 can be abbreviated as ‘fin’. d5449 1 a5449 1 Contrast this with the ‘return’ command (*note Returning from a d5452 5 a5456 5 ‘set print finish [on|off]’ ‘show print finish’ By default the ‘finish’ command will show the value that is returned by the function. This can be disabled using ‘set print finish off’. When disabled, the value is still entered into the d5459 2 a5460 2 ‘until’ ‘u’ d5464 1 a5464 1 ‘next’ command, except that when ‘until’ encounters a jump, it d5469 2 a5470 2 stepping though it, ‘until’ makes your program continue execution until it exits the loop. In contrast, a ‘next’ command at the end d5474 1 a5474 1 ‘until’ always stops your program if it attempts to exit the d5477 1 a5477 1 ‘until’ may produce somewhat counterintuitive results if the order d5479 3 a5481 3 example, in the following excerpt from a debugging session, the ‘f’ (‘frame’) command shows that execution is stopped at line ‘206’; yet when we use ‘until’, we get to line ‘195’: d5491 2 a5492 2 the start, of the loop--even though the test in a C ‘for’-loop is written before the body of the loop. The ‘until’ command appeared d5497 2 a5498 2 ‘until’ with no argument works by means of single instruction stepping, and hence is slower than ‘until’ with an argument. d5500 2 a5501 2 ‘until LOCSPEC’ ‘u LOCSPEC’ d5506 1 a5506 1 breakpoints, and hence is quicker than ‘until’ without an argument. d5508 1 a5508 1 current frame. This implies that ‘until’ can be used to skip over d5510 2 a5511 2 the current location is line ‘96’, issuing ‘until 99’ will execute the program up to line ‘99’ in the same invocation of factorial, d5522 1 a5522 1 ‘advance LOCSPEC’ d5526 2 a5527 2 Location Specifications::. This command is similar to ‘until’, but ‘advance’ will not skip over recursive function calls, and the d5531 3 a5533 3 ‘stepi’ ‘stepi ARG’ ‘si’ d5537 1 a5537 1 It is often useful to do ‘display/i $pc’ when stepping by machine d5542 1 a5542 1 An argument is a repeat count, as in ‘step’. d5544 3 a5546 3 ‘nexti’ ‘nexti ARG’ ‘ni’ d5550 1 a5550 1 An argument is a repeat count, as in ‘next’. d5552 3 a5554 3 By default, and if available, GDB makes use of target-assisted “range stepping”. In other words, whenever you use a stepping command (e.g., ‘step’, ‘next’), GDB tells the target to step the corresponding range of d5563 2 a5564 2 ‘set range-stepping’ ‘show range-stepping’ d5567 1 a5567 1 If ‘on’, and the target supports it, GDB tells the target to step a d5569 2 a5570 2 single-steps. If ‘off’, GDB always issues single-steps, even if range stepping is supported by the target. The default is ‘on’. d5579 1 a5579 1 uninteresting to debug. The ‘skip’ command lets you tell GDB to skip a d5591 4 a5594 4 Suppose you wish to step into the functions ‘foo’ and ‘bar’, but you are not interested in stepping through ‘boring’. If you run ‘step’ at line 103, you'll enter ‘boring()’, but if you run ‘next’, you'll step over both ‘foo’ and ‘boring’! d5596 2 a5597 2 One solution is to ‘step’ into ‘boring’ and use the ‘finish’ command to immediately exit it. But this can become tedious if ‘boring’ is d5600 3 a5602 3 A more flexible solution is to execute ‘skip boring’. This instructs GDB never to step into ‘boring’. Now when you execute ‘step’ at line 103, you'll step over ‘boring’ and directly into ‘foo’. d5606 1 a5606 1 matches the function's name, file name or a ‘glob’-style pattern that d5610 1 a5610 1 Regular Expressions". See for example ‘man 7 regex’ on GNU/Linux d5612 3 a5614 3 whatever is provided by the ‘regcomp’ function of the underlying system. See for example ‘man 7 glob’ on GNU/Linux systems for a description of ‘glob’-style patterns. d5616 2 a5617 2 ‘skip [OPTIONS]’ The basic form of the ‘skip’ command takes zero or more options d5621 2 a5622 2 ‘-file FILE’ ‘-fi FILE’ d5625 2 a5626 2 ‘-gfile FILE-GLOB-PATTERN’ ‘-gfi FILE-GLOB-PATTERN’ d5632 2 a5633 2 ‘-function LINESPEC’ ‘-fu LINESPEC’ d5638 2 a5639 2 ‘-rfunction REGEXP’ ‘-rfu REGEXP’ d5644 1 a5644 1 there is generally no need to step into C++ ‘std::string’ d5654 1 a5654 1 destructor in the ‘std’ namespace you can do: d5661 1 a5661 1 ‘skip function [LINESPEC]’ d5669 2 a5670 2 (If you have a function called ‘file’ that you want to skip, use ‘skip function file’.) d5672 1 a5672 1 ‘skip file [FILENAME]’ d5685 1 a5685 1 ‘info skip [RANGE]’ d5688 1 a5688 1 marked for skipping. ‘info skip’ prints the following information d5694 2 a5695 2 Enabled skips are marked with ‘y’. Disabled skips are marked with ‘n’. d5697 2 a5698 2 If the file name is a ‘glob’ pattern this is ‘y’. Otherwise it is ‘n’. d5700 2 a5701 2 The name or ‘glob’ pattern of the file to be skipped. If no file is specified this is ‘’. d5703 2 a5704 2 If the function name is a ‘regular expression’ this is ‘y’. Otherwise it is ‘n’. d5707 1 a5707 1 function is specified this is ‘’. d5709 1 a5709 1 ‘skip delete [RANGE]’ d5713 1 a5713 1 ‘skip enable [RANGE]’ d5717 1 a5717 1 ‘skip disable [RANGE]’ d5721 1 a5721 1 ‘set debug skip [on|off]’ d5725 1 a5725 1 ‘show debug skip’ d5737 4 a5740 4 kind a name and a number. For example, in Unix ‘SIGINT’ is the signal a program gets when you type an interrupt character (often ‘Ctrl-c’); ‘SIGSEGV’ is the signal a program gets from referencing a place in memory far away from all the areas in use; ‘SIGALRM’ occurs when the d5744 3 a5746 3 Some signals, including ‘SIGALRM’, are a normal part of the functioning of your program. Others, such as ‘SIGSEGV’, indicate errors; these signals are “fatal” (they kill your program immediately) d5748 1 a5748 1 signal. ‘SIGINT’ does not indicate an error in your program, but it is d5757 1 a5757 1 ‘SIGALRM’ be silently passed to your program (so as not to interfere d5760 1 a5760 1 settings with the ‘handle’ command. d5762 2 a5763 2 ‘info signals’ ‘info handle’ d5768 1 a5768 1 ‘info signals SIG’ d5772 1 a5772 1 ‘info handle’ is an alias for ‘info signals’. d5774 1 a5774 1 ‘catch signal [SIGNAL... | ‘all’]’ d5778 1 a5778 1 ‘handle SIGNAL [ SIGNAL ... ] [KEYWORDS...]’ d5780 4 a5783 4 number of a signal or its name (with or without the ‘SIG’ at the beginning); a list of signal numbers of the form ‘LOW-HIGH’; or the word ‘all’, meaning all the known signals, except ‘SIGINT’ and ‘SIGTRAP’, which are used by GDB. Optional argument KEYWORDS, d5787 1 a5787 1 The keywords allowed by the ‘handle’ command can be abbreviated. d5790 1 a5790 1 ‘nostop’ d5794 1 a5794 1 ‘stop’ d5796 1 a5796 1 implies the ‘print’ keyword as well. d5798 1 a5798 1 ‘print’ d5801 1 a5801 1 ‘noprint’ d5803 1 a5803 1 implies the ‘nostop’ keyword as well. d5805 2 a5806 2 ‘pass’ ‘noignore’ d5809 1 a5809 1 and not handled. ‘pass’ and ‘noignore’ are synonyms. d5811 4 a5814 4 ‘nopass’ ‘ignore’ GDB should not allow your program to see this signal. ‘nopass’ and ‘ignore’ are synonyms. d5818 3 a5820 3 ‘pass’ is in effect for the signal in question _at that time_. In other words, after GDB reports a signal, you can use the ‘handle’ command with ‘pass’ or ‘nopass’ to control whether your program sees that signal when d5823 3 a5825 3 The default is set to ‘nostop’, ‘noprint’, ‘pass’ for non-erroneous signals such as ‘SIGALRM’, ‘SIGWINCH’ and ‘SIGCHLD’, and to ‘stop’, ‘print’, ‘pass’ for the erroneous signals. d5827 1 a5827 1 You can also use the ‘signal’ command to prevent your program from d5834 1 a5834 1 you can continue with ‘signal 0’. *Note Giving your Program a Signal: d5838 2 a5839 2 ‘handle nostop’ and ‘handle pass’ set arrives while a stepping command (e.g., ‘stepi’, ‘step’, ‘next’) is in progress, GDB lets the signal d5843 1 a5843 1 ‘handle nostop’) from changing the focus of debugging unexpectedly. d5845 1 a5845 1 another signal that has ‘handle stop’ in effect, or for any other event d5848 1 a5848 1 ‘handle print’ is set. d5850 3 a5852 3 If you set ‘handle pass’ for a signal, and your program sets up a handler for it, then issuing a stepping command, such as ‘step’ or ‘stepi’, when your program is stopped due to the signal will step _into_ d5855 1 a5855 1 Likewise, if you use the ‘queue-signal’ command to queue a signal to d5860 2 a5861 2 Here's an example, using ‘stepi’ to step to the first instruction of ‘SIGUSR1’'s handler: d5876 1 a5876 1 The same, but using ‘queue-signal’ instead of waiting for the program d5890 1 a5890 1 variable ‘$_siginfo’, and consists of data that is passed by the kernel d5893 3 a5895 3 data type using the ‘ptype $_siginfo’ command. On Unix systems, it typically corresponds to the standard ‘siginfo_t’ type, as defined in the ‘signal.h’ system header. d5926 1 a5926 1 Depending on target support, ‘$_siginfo’ may also be writable. d5928 1 a5928 1 On some targets, a ‘SIGSEGV’ can be caused by a boundary violation, d5931 1 a5931 1 told to handle the signal. With ‘handle stop SIGSEGV’, GDB displays the d5933 1 a5933 1 bounds, while with ‘handle nostop SIGSEGV’ no additional information is d5957 1 a5957 1 default mode, referred to as “all-stop mode”, when any thread in your d5960 1 a5960 1 GDB also supports “non-stop mode”, in which other threads can continue d5986 1 a5986 1 ‘step’ or ‘next’. d6003 1 a6003 1 ‘[Switching to Thread N]’ to identify the thread. d6008 1 a6008 1 ‘set scheduler-locking MODE’ d6012 1 a6012 1 ‘off’ d6015 1 a6015 1 ‘on’ d6020 2 a6021 2 ‘step’ Behaves like ‘on’ when stepping, and ‘off’ otherwise. Threads d6024 1 a6024 1 commands like ‘continue’, ‘until’, or ‘finish’. d6033 2 a6034 2 ‘replay’ Behaves like ‘on’ in replay mode, and ‘off’ in either record d6037 1 a6037 1 ‘show scheduler-locking’ d6041 1 a6041 1 ‘continue’, ‘next’ or ‘step’, GDB allows only threads of the current d6043 1 a6043 1 with two threads, the ‘continue’ command resumes only the two threads of d6051 1 a6051 1 ‘set schedule-multiple’ command. d6053 1 a6053 1 ‘set schedule-multiple’ d6055 5 a6059 5 resumed when an execution command is issued. When ‘on’, all threads of all processes are allowed to run. When ‘off’, only the threads of the current process are resumed. The default is ‘off’. The ‘scheduler-locking’ mode takes precedence when set to ‘on’, or while you are stepping and set to ‘step’. d6061 1 a6061 1 ‘show schedule-multiple’ d6076 1 a6076 1 external events. This is referred to as “non-stop” mode. d6081 1 a6081 1 commands such as ‘continue’ and ‘step’ apply by default only to the d6100 1 a6100 1 ‘set non-stop on’ d6102 1 a6102 1 ‘set non-stop off’ d6104 1 a6104 1 ‘show non-stop’ d6109 1 a6109 1 mode. In particular, the ‘set non-stop’ preference is only consulted d6116 2 a6117 2 thread by default. That is, ‘continue’ only continues one thread. To continue all threads, issue ‘continue -a’ or ‘c -a’. d6125 2 a6126 2 Suspending execution is done with the ‘interrupt’ command when running in the background, or ‘Ctrl-c’ during foreground execution. In d6129 1 a6129 1 program, use ‘interrupt -a’. d6131 1 a6131 1 Other execution commands do not currently support the ‘-a’ option. d6156 3 a6158 3 To specify background execution, add a ‘&’ to the command. For example, the background form of the ‘continue’ command is ‘continue&’, or just ‘c&’. The execution commands that accept background execution d6161 1 a6161 1 ‘run’ d6164 1 a6164 1 ‘attach’ d6167 1 a6167 1 ‘step’ d6170 1 a6170 1 ‘stepi’ d6173 1 a6173 1 ‘next’ d6176 1 a6176 1 ‘nexti’ d6179 1 a6179 1 ‘continue’ d6182 1 a6182 1 ‘finish’ d6185 1 a6185 1 ‘until’ d6194 1 a6194 1 ‘help’ and ‘info break’. d6197 1 a6197 1 by using the ‘interrupt’ command. d6199 2 a6200 2 ‘interrupt’ ‘interrupt -a’ d6203 1 a6203 1 ‘interrupt’ stops the whole process, but in non-stop mode, it stops d6205 1 a6205 1 mode, use ‘interrupt -a’. d6217 2 a6218 2 ‘break LOCSPEC thread THREAD-ID’ ‘break LOCSPEC thread THREAD-ID if ...’ d6222 1 a6222 1 Use the qualifier ‘thread THREAD-ID’ with a breakpoint command to d6226 1 a6226 1 first column of the ‘info threads’ display. d6228 1 a6228 1 If you do not specify ‘thread THREAD-ID’ when you set a breakpoint, d6231 2 a6232 2 You can use the ‘thread’ qualifier on conditional breakpoints as well; in this case, place ‘thread THREAD-ID’ before or after the d6245 1 a6245 1 thread exit, but also when you detach from the process with the ‘detach’ d6249 1 a6249 1 the user explicitly asks for the thread list with the ‘info threads’ d6254 1 a6254 1 Tasks::); using more than one of the ‘thread’, ‘inferior’, or ‘task’ d6278 1 a6278 1 The call to ‘sleep’ will return early if a different thread stops at d6308 2 a6309 2 When all of these are set to ‘off’, then GDB is said to be “observer mode”. As a convenience, the variable ‘observer’ can be set to disable d6314 1 a6314 1 ‘may-insert-breakpoints’ but disabled ‘may-write-memory’, then d6318 5 a6322 5 ‘set observer on’ ‘set observer off’ When set to ‘on’, this disables all the permission variables below (except for ‘insert-fast-tracepoints’), plus enables non-stop debugging. Setting this to ‘off’ switches back to normal d6325 1 a6325 1 ‘show observer’ d6328 2 a6329 2 ‘set may-write-registers on’ ‘set may-write-registers off’ d6331 2 a6332 2 registers, such as with assignment expressions in ‘print’, or the ‘jump’ command. It defaults to ‘on’. d6334 1 a6334 1 ‘show may-write-registers’ d6337 2 a6338 2 ‘set may-write-memory on’ ‘set may-write-memory off’ d6340 2 a6341 2 memory, such as with assignment expressions in ‘print’. It defaults to ‘on’. d6343 1 a6343 1 ‘show may-write-memory’ d6346 2 a6347 2 ‘set may-insert-breakpoints on’ ‘set may-insert-breakpoints off’ d6350 1 a6350 1 GDB. It defaults to ‘on’. d6352 1 a6352 1 ‘show may-insert-breakpoints’ d6355 2 a6356 2 ‘set may-insert-tracepoints on’ ‘set may-insert-tracepoints off’ d6360 1 a6360 1 of ‘may-insert-fast-tracepoints’. It defaults to ‘on’. d6362 1 a6362 1 ‘show may-insert-tracepoints’ d6365 2 a6366 2 ‘set may-insert-fast-tracepoints on’ ‘set may-insert-fast-tracepoints off’ d6370 1 a6370 1 of ‘may-insert-tracepoints’. It defaults to ‘on’. d6372 1 a6372 1 ‘show may-insert-fast-tracepoints’ d6375 2 a6376 2 ‘set may-interrupt on’ ‘set may-interrupt off’ d6378 2 a6379 2 execution. When this variable is ‘off’, the ‘interrupt’ command will have no effect, nor will ‘Ctrl-c’. It defaults to ‘on’. d6381 1 a6381 1 ‘show may-interrupt’ d6412 1 a6412 1 activated with the ‘record’ or ‘record btrace’ commands. *Note Process d6420 2 a6421 2 ‘reverse-continue [IGNORE-COUNT]’ ‘rc [IGNORE-COUNT]’ d6427 1 a6427 1 ‘reverse-step [COUNT]’ d6431 1 a6431 1 Like the ‘step’ command, ‘reverse-step’ will only stop at the d6434 1 a6434 1 to debuggable functions, ‘reverse-step’ will step (backward) into d6438 2 a6439 2 Also, as with the ‘step’ command, if non-debuggable functions are called, ‘reverse-step’ will run thru them backward without d6442 1 a6442 1 ‘reverse-stepi [COUNT]’ d6446 1 a6446 1 instance, if the last instruction was a jump, ‘reverse-stepi’ will d6450 1 a6450 1 ‘reverse-next [COUNT]’ d6454 1 a6454 1 the first line of a function, ‘reverse-next’ will take you back to d6456 1 a6456 1 as the normal ‘next’ command would take you from the last line of a d6459 2 a6460 2 ‘reverse-nexti [COUNT]’ Like ‘nexti’, ‘reverse-nexti’ executes a single instruction in d6463 1 a6463 1 another function, ‘reverse-nexti’ will continue to execute in d6467 3 a6469 3 ‘reverse-finish’ Just as the ‘finish’ command takes you to the point where the current function returns, ‘reverse-finish’ takes you to the point d6473 1 a6473 1 ‘set exec-direction’ d6475 1 a6475 1 ‘set exec-direction reverse’ d6478 3 a6480 3 include ‘step, stepi, next, nexti, continue, and finish’. The ‘return’ command cannot be used in reverse mode. ‘set exec-direction forward’ d6506 1 a6506 1 On some platforms, GDB provides a special “process record and replay” d6511 1 a6511 1 for the next instruction, GDB will debug in “replay mode”. In the d6520 1 a6520 1 GDB will debug in “record mode”. In this mode, the inferior executes d6538 1 a6538 1 debugging, and when remote debugging via ‘gdbserver’. d6543 1 a6543 1 ‘record METHOD’ d6546 1 a6546 1 parameter the command uses the ‘full’ recording method. The d6549 1 a6549 1 ‘full’ d6554 1 a6554 1 ‘btrace FORMAT’ d6562 2 a6563 2 reconnecting. The recording may be stopped using ‘record stop’. d6569 2 a6570 2 ‘bts’ Use the “Branch Trace Store” (BTS) recording format. In d6574 2 a6575 2 ‘pt’ Use the “Intel Processor Trace” recording format. In d6593 2 a6594 2 with the ‘run’ or ‘start’ commands, and then start the recording with the ‘record METHOD’ command. d6603 1 a6603 1 not all recording methods are available. The ‘full’ recording d6606 1 a6606 1 ‘record stop’ d6629 1 a6629 1 ‘record goto’ d6633 2 a6634 2 ‘record goto begin’ ‘record goto start’ d6637 1 a6637 1 ‘record goto end’ d6640 1 a6640 1 ‘record goto N’ d6643 3 a6645 3 ‘record save FILENAME’ Save the execution log to a file ‘FILENAME’. Default filename is ‘gdb_record.PROCESS_ID’, where PROCESS_ID is the process ID of the d6650 7 a6656 7 ‘record restore FILENAME’ Restore the execution log from a file ‘FILENAME’. File must have been created with ‘record save’. ‘set record full insn-number-max LIMIT’ ‘set record full insn-number-max unlimited’ Set the limit of instructions to be recorded for the ‘full’ d6666 1 a6666 1 ‘stop-at-limit’ option, described below.) d6668 1 a6668 1 If LIMIT is ‘unlimited’ or zero, GDB will never delete recorded d6672 2 a6673 2 ‘show record full insn-number-max’ Show the limit of instructions to be recorded with the ‘full’ d6676 2 a6677 2 ‘set record full stop-at-limit’ Control the behavior of the ‘full’ recording method when the number d6688 2 a6689 2 ‘show record full stop-at-limit’ Show the current setting of ‘stop-at-limit’. d6691 1 a6691 1 ‘set record full memory-query’ d6693 1 a6693 1 caused by an instruction for the ‘full’ recording method. If ON, d6701 2 a6702 2 ‘show record full memory-query’ Show the current setting of ‘memory-query’. d6704 1 a6704 1 The ‘btrace’ record target does not trace data. As a convenience, d6712 4 a6715 4 ‘set record btrace replay-memory-access’ Control the behavior of the ‘btrace’ recording method when accessing memory during replay. If ‘read-only’ (the default), GDB will only allow accesses to read-only memory. If ‘read-write’, GDB d6720 1 a6720 1 ‘set record btrace cpu IDENTIFIER’ d6728 2 a6729 2 the decoding failures. These corrections are known as “errata workarounds”, and are enabled based on the processor on which the d6738 2 a6739 2 ‘VENDOR:PROCESSOR IDENTIFIER’. In addition, there are two special identifiers, ‘none’ and ‘auto’ (default). d6744 1 a6744 1 ‘intel’ FAMILY/MODEL[/STEPPING] d6748 1 a6748 1 be obtained from ‘/proc/cpuinfo’. d6750 1 a6750 1 If IDENTIFIER is ‘auto’, enable errata workarounds for the d6752 1 a6752 1 ‘none’, errata workarounds are disabled. d6770 2 a6771 2 ‘show record btrace replay-memory-access’ Show the current setting of ‘replay-memory-access’. d6773 1 a6773 1 ‘show record btrace cpu’ d6777 2 a6778 2 ‘set record btrace bts buffer-size SIZE’ ‘set record btrace bts buffer-size unlimited’ d6785 2 a6786 2 buffer size may differ from the requested SIZE. Use the ‘info record’ command to see the actual buffer size for each thread that d6789 1 a6789 1 If LIMIT is ‘unlimited’ or zero, GDB will try to allocate a buffer d6796 1 a6796 1 ‘show record btrace bts buffer-size SIZE’ d6800 2 a6801 2 ‘set record btrace pt buffer-size SIZE’ ‘set record btrace pt buffer-size unlimited’ d6809 1 a6809 1 Use the ‘info record’ command to see the actual buffer size for d6812 1 a6812 1 If LIMIT is ‘unlimited’ or zero, GDB will try to allocate a buffer d6819 1 a6819 1 ‘show record btrace pt buffer-size SIZE’ d6823 1 a6823 1 ‘info record’ d6827 2 a6828 2 ‘full’ For the ‘full’ recording method, it shows the state of process d6831 2 a6832 2 • Whether in record mode or replay mode. • Lowest recorded instruction number (counting from when d6835 2 a6836 2 • Highest recorded instruction number. • Current instruction about to be replayed (if in replay d6838 2 a6839 2 • Number of instructions contained in the execution log. • Maximum number of instructions that may be contained in d6842 2 a6843 2 ‘btrace’ For the ‘btrace’ recording method, it shows: d6845 3 a6847 3 • Recording format. • Number of instructions that have been recorded. • Number of blocks of sequential control-flow formed by the d6849 1 a6849 1 • Whether in record mode or replay mode. d6851 2 a6852 2 For the ‘bts’ recording format, it also shows: • Size of the perf ring buffer. d6854 2 a6855 2 For the ‘pt’ recording format, it also shows: • Size of the perf ring buffer. d6857 1 a6857 1 ‘record delete’ d6863 1 a6863 1 ‘record instruction-history’ d6866 1 a6866 1 using the ‘set record instruction-history-size’ command. d6870 4 a6873 4 ‘/m’ or ‘/s’ modifier, and print the raw instructions in hex as well as in symbolic form by specifying the ‘/r’ or ‘/b’ modifier. The behaviour of the ‘/m’, ‘/s’, ‘/r’, and ‘/b’ modifiers are the same as for the ‘disassemble’ command (*note ‘disassemble’: d6880 1 a6880 1 the ‘/p’ modifier. d6884 1 a6884 1 omitted by specifying the ‘/f’ modifier. d6886 1 a6886 1 Speculatively executed instructions are prefixed with ‘?’. This d6892 1 a6892 1 ‘record instruction-history INSN’ d6896 1 a6896 1 ‘record instruction-history INSN, +/-N’ d6898 2 a6899 2 If N is preceded with ‘+’, disassembles N instructions after instruction number INSN. If N is preceded with ‘-’, d6902 1 a6902 1 ‘record instruction-history’ d6905 1 a6905 1 ‘record instruction-history -’ d6909 1 a6909 1 ‘record instruction-history BEGIN, END’ d6916 9 a6924 9 ‘set record instruction-history-size SIZE’ ‘set record instruction-history-size unlimited’ Define how many instructions to disassemble in the ‘record instruction-history’ command. The default value is 10. A SIZE of ‘unlimited’ means unlimited instructions. ‘show record instruction-history-size’ Show how many instructions to disassemble in the ‘record instruction-history’ command. d6926 1 a6926 1 ‘record function-call-history’ d6930 2 a6931 2 instruction sequence (if the ‘/l’ modifier is specified), and the instructions numbers that form the sequence (if the ‘/i’ modifier d6933 2 a6934 2 stack depth if the ‘/c’ modifier is specified. The ‘/l’, ‘/i’, and ‘/c’ modifiers can be given together. d6953 1 a6953 1 the ‘set record function-call-history-size’ command. Functions are d6957 1 a6957 1 ‘record function-call-history FUNC’ d6960 1 a6960 1 ‘record function-call-history FUNC, +/-N’ d6962 2 a6963 2 preceded with ‘+’, prints N functions after function number FUNC. If N is preceded with ‘-’, prints N functions before d6966 1 a6966 1 ‘record function-call-history’ d6969 1 a6969 1 ‘record function-call-history -’ d6972 1 a6972 1 ‘record function-call-history BEGIN, END’ d6978 9 a6986 9 ‘set record function-call-history-size SIZE’ ‘set record function-call-history-size unlimited’ Define how many functions to print in the ‘record function-call-history’ command. The default value is 10. A size of ‘unlimited’ means unlimited functions. ‘show record function-call-history-size’ Show how many functions to print in the ‘record function-call-history’ command. d7001 2 a7002 2 data called a “stack frame”. The stack frames are allocated in a region of memory called the “call stack”. d7007 1 a7007 1 One of the stack frames is “selected” by GDB and many GDB commands d7014 1 a7014 1 executing frame and describes it briefly, similar to the ‘frame’ command d7032 2 a7033 2 The call stack is divided up into contiguous pieces called “stack frames”, or “frames” for short; each frame is the data associated with d7039 2 a7040 2 the function ‘main’. This is called the “initial” frame or the “outermost” frame. Each time a function is called, a new frame is made. d7044 1 a7044 1 actually occurring is called the “innermost” frame. This is the most d7051 1 a7051 1 kept in a register called the “frame pointer register” (*note $fp: d7054 1 a7054 1 GDB labels each existing stack frame with a “level”, a number that is d7057 1 a7057 1 frames in GDB commands. The terms “frame number” and “frame level” can d7062 1 a7062 1 ‘-fomit-frame-pointer’ d7082 2 a7083 2 To print a backtrace of the entire stack, use the ‘backtrace’ command, or its alias ‘bt’. This command will print one line per frame d7086 1 a7086 1 character, normally ‘Ctrl-c’. d7088 2 a7089 2 ‘backtrace [OPTION]... [QUALIFIER]... [COUNT]’ ‘bt [OPTION]... [QUALIFIER]... [COUNT]’ d7094 2 a7095 2 ‘N’ ‘N’ d7099 2 a7100 2 ‘-N’ ‘-N’ d7106 1 a7106 1 ‘-full’ d7111 1 a7111 1 ‘-no-filters’ d7116 1 a7116 1 with ‘Python’ support. d7118 1 a7118 1 ‘-hide’ d7122 1 a7122 1 elided. The ‘-hide’ option causes elided frames to not be d7125 3 a7127 3 The ‘backtrace’ command also supports a number of options that allow overriding relevant global print settings as set by ‘set backtrace’ and ‘set print’ subcommands: d7129 2 a7130 2 ‘-past-main [on|off]’ Set whether backtraces should continue past ‘main’. Related d7133 1 a7133 1 ‘-past-entry [on|off]’ d7137 1 a7137 1 ‘-entry-values no|only|preferred|if-needed|both|compact|default’ d7141 1 a7141 1 ‘-frame-arguments all|scalars|none’ d7145 1 a7145 1 ‘-raw-frame-arguments [on|off]’ d7149 1 a7149 1 ‘-frame-info auto|source-line|location|source-and-location|location-and-address|short-location’ d7156 2 a7157 2 ‘full’ Equivalent to the ‘-full’ option. d7159 2 a7160 2 ‘no-filters’ Equivalent to the ‘-no-filters’ option. d7162 2 a7163 2 ‘hide’ Equivalent to the ‘-hide’ option. d7165 2 a7166 2 The names ‘where’ and ‘info stack’ (abbreviated ‘info s’) are additional aliases for ‘backtrace’. d7170 2 a7171 2 the threads, use the command ‘thread apply’ (*note thread apply: Threads.). For example, if you type ‘thread apply all backtrace’, GDB d7176 2 a7177 2 name. The program counter value is also shown--unless you use ‘set print address off’. The backtrace also shows the source file name and d7182 2 a7183 2 Here is an example of a backtrace. It was made with the command ‘bt 3’, so it shows the innermost three frames. d7194 1 a7194 1 for line ‘993’ of ‘builtin.c’. d7196 1 a7196 1 The value of parameter ‘data’ in frame 1 has been replaced by ‘...’. By d7198 2 a7199 2 (integer, pointer, enumeration, etc). See command ‘set print frame-arguments’ in *note Print Settings:: for more details on how to d7201 1 a7201 1 ‘set print frame-info’ (*note Print Settings::) controls what frame d7220 1 a7220 1 shown as ‘’. d7228 1 a7228 1 ‘main’(1). When GDB finds the entry function in a backtrace it will d7235 2 a7236 2 ‘set backtrace past-main’ ‘set backtrace past-main on’ d7239 1 a7239 1 ‘set backtrace past-main off’ d7243 1 a7243 1 ‘show backtrace past-main’ d7246 2 a7247 2 ‘set backtrace past-entry’ ‘set backtrace past-entry on’ d7251 1 a7251 1 ‘main’ (or equivalent) is called. d7253 1 a7253 1 ‘set backtrace past-entry off’ d7257 1 a7257 1 ‘show backtrace past-entry’ d7260 4 a7263 4 ‘set backtrace limit N’ ‘set backtrace limit 0’ ‘set backtrace limit unlimited’ Limit the backtrace to N levels. A value of ‘unlimited’ or zero d7266 1 a7266 1 ‘show backtrace limit’ d7271 2 a7272 2 ‘set filename-display’ ‘set filename-display relative’ d7276 1 a7276 1 ‘set filename-display basename’ d7279 1 a7279 1 ‘set filename-display absolute’ d7282 1 a7282 1 ‘show filename-display’ d7288 1 a7288 1 environment) are not required to have a ‘main’ function as the entry d7302 3 a7304 3 ‘frame [ FRAME-SELECTION-SPEC ]’ ‘f [ FRAME-SELECTION-SPEC ]’ The ‘frame’ command allows different stack frames to be selected. d7307 2 a7308 2 ‘NUM’ ‘level NUM’ d7312 1 a7312 1 frame is usually the one for ‘main’. d7315 1 a7315 1 stack, the string ‘level’ can be omitted. For example, the d7321 1 a7321 1 ‘address STACK-ADDRESS’ d7323 2 a7324 2 STACK-ADDRESS for a frame can be seen in the output of ‘info frame’, for example: d7334 1 a7334 1 The STACK-ADDRESS for this frame is ‘0x7fffffffda30’ as d7339 1 a7339 1 ‘function FUNCTION-NAME’ d7344 1 a7344 1 ‘view STACK-ADDRESS [ PC-ADDR ]’ d7356 1 a7356 1 ‘frame view’ then you can always return to the original stack d7358 1 a7358 1 for example ‘frame level 0’. d7360 1 a7360 1 ‘up N’ d7365 1 a7365 1 ‘down N’ d7369 1 a7369 1 abbreviate ‘down’ as ‘do’. d7383 1 a7383 1 After such a printout, the ‘list’ command with no arguments prints d7386 1 a7386 1 program by typing ‘edit’. *Note Printing Source Lines: List, for d7389 2 a7390 2 ‘select-frame [ FRAME-SELECTION-SPEC ]’ The ‘select-frame’ command is a variant of ‘frame’ that does not d7394 1 a7394 1 the ‘frame’ command described in *note Selecting a Frame: d7397 3 a7399 3 ‘up-silently N’ ‘down-silently N’ These two commands are variants of ‘up’ and ‘down’, respectively; d7414 2 a7415 2 ‘frame’ ‘f’ d7418 1 a7418 1 selected stack frame. It can be abbreviated ‘f’. With an d7422 2 a7423 2 ‘info frame’ ‘info f’ d7427 4 a7430 4 • the address of the frame • the address of the next frame down (called by this frame) • the address of the next frame up (caller of this frame) • the language in which the source code corresponding to this d7432 3 a7434 3 • the address of the frame's arguments • the address of the frame's local variables • the program counter saved in it (the address of execution in d7436 1 a7436 1 • which registers were saved in the frame d7441 2 a7442 2 ‘info frame [ FRAME-SELECTION-SPEC ]’ ‘info f [ FRAME-SELECTION-SPEC ]’ d7445 1 a7445 1 the ‘frame’ command (*note Selecting a Frame: Selection.). The d7448 1 a7448 1 ‘info args [-q]’ d7451 1 a7451 1 The optional flag ‘-q’, which stands for ‘quiet’, disables printing d7455 2 a7456 2 ‘info args [-q] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info args’, but only print the arguments selected with the d7463 1 a7463 1 as printed by the ‘whatis’ command, match the regular expression d7471 1 a7471 1 ‘info locals [-q]’ d7477 1 a7477 1 The optional flag ‘-q’, which stands for ‘quiet’, disables printing d7481 2 a7482 2 ‘info locals [-q] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info locals’, but only print the local variables selected d7489 1 a7489 1 types, as printed by the ‘whatis’ command, match the regular d7498 2 a7499 2 The command ‘info locals -q -t TYPE_REGEXP’ can usefully be combined with the commands ‘frame apply’ and ‘thread apply’. For d7501 2 a7502 2 Initialization types (RAII) such as ‘lock_something_t’: each local variable of type ‘lock_something_t’ automatically places a lock d7515 2 a7516 2 ‘frame apply [all | COUNT | -COUNT | level LEVEL...] [OPTION]... COMMAND’ The ‘frame apply’ command allows you to apply the named COMMAND to d7519 2 a7520 2 ‘all’ Specify ‘all’ to apply COMMAND to all frames. d7522 1 a7522 1 ‘COUNT’ d7526 1 a7526 1 ‘-COUNT’ d7530 2 a7531 2 ‘level’ Use ‘level’ to apply COMMAND to the set of frames identified d7534 2 a7535 2 in the first field of the ‘backtrace’ command output. E.g., ‘2-4 6-8 3’ indicates to apply COMMAND for the frames at d7538 3 a7540 3 Note that the frames on which ‘frame apply’ applies a command are also influenced by the ‘set backtrace’ settings such as ‘set backtrace past-main’ and ‘set backtrace limit N’. *Note d7543 2 a7544 2 The ‘frame apply’ command also supports a number of options that allow overriding relevant ‘set backtrace’ settings: d7546 2 a7547 2 ‘-past-main [on|off]’ Whether backtraces should continue past ‘main’. Related d7550 1 a7550 1 ‘-past-entry [on|off]’ d7556 1 a7556 1 COMMAND will abort ‘frame apply’. The following options can be d7559 3 a7561 3 ‘-c’ The flag ‘-c’, which stands for ‘continue’, causes any errors in COMMAND to be displayed, and the execution of ‘frame apply’ d7563 2 a7564 2 ‘-s’ The flag ‘-s’, which stands for ‘silent’, causes any errors or d7568 2 a7569 2 ‘-q’ The flag ‘-q’ (‘quiet’) disables printing the frame d7572 3 a7574 3 The following example shows how the flags ‘-c’ and ‘-s’ are working when applying the command ‘p j’ to all frames, where variable ‘j’ can only be successfully printed in the outermost ‘#1 main’ frame. d7589 1 a7589 1 By default, ‘frame apply’, prints the frame location information d7599 1 a7599 1 If the flag ‘-q’ is given, no frame information is printed: d7605 2 a7606 2 ‘faas COMMAND’ Shortcut for ‘frame apply all -s COMMAND’. Applies COMMAND on all d7614 1 a7614 1 The ‘faas’ command accepts the same options as the ‘frame apply’ d7617 1 a7617 1 Note that the command ‘tfaas COMMAND’ applies COMMAND on all frames d7632 1 a7632 1 ‘info frame-filter’ d7636 1 a7636 1 ‘disable frame-filter FILTER-DICTIONARY FILTER-NAME’ d7638 3 a7640 3 and FILTER-NAME. The FILTER-DICTIONARY may be ‘all’, ‘global’, ‘progspace’, or the name of the object file where the frame filter dictionary resides. When ‘all’ is specified, all frame filters d7642 1 a7642 1 of the frame filter and is used when ‘all’ is not the option for d7646 1 a7646 1 ‘enable frame-filter FILTER-DICTIONARY FILTER-NAME’ d7648 3 a7650 3 and FILTER-NAME. The FILTER-DICTIONARY may be ‘all’, ‘global’, ‘progspace’ or the name of the object file where the frame filter dictionary resides. When ‘all’ is specified, all frame filters d7652 1 a7652 1 of the frame filter and is used when ‘all’ is not the option for d7704 1 a7704 1 ‘set frame-filter priority FILTER-DICTIONARY FILTER-NAME PRIORITY’ d7707 1 a7707 1 The FILTER-DICTIONARY may be ‘global’, ‘progspace’ or the name of d7711 1 a7711 1 ‘show frame-filter priority FILTER-DICTIONARY FILTER-NAME’ d7714 1 a7714 1 The FILTER-DICTIONARY may be ‘global’, ‘progspace’ or the name of d7784 2 a7785 2 To print lines from a source file, use the ‘list’ command (abbreviated ‘l’). By default, ten lines are printed. There are several ways to d7789 1 a7789 1 Here are the forms of the ‘list’ command most commonly used: d7791 1 a7791 1 ‘list LINENUM’ d7795 1 a7795 1 ‘list FUNCTION’ d7798 1 a7798 1 ‘list’ d7800 1 a7800 1 ‘list’ command, this prints lines following the last lines printed; d7803 1 a7803 1 Stack.), this prints lines centered around that line. If no ‘list’ d7805 1 a7805 1 the lines around the function ‘main’. d7807 1 a7807 1 ‘list +’ d7810 1 a7810 1 ‘list -’ d7813 1 a7813 1 ‘list .’ d7819 1 a7819 1 the ‘list’ command. You can change this using ‘set listsize’: d7821 12 a7832 12 ‘set listsize COUNT’ ‘set listsize unlimited’ Make the ‘list’ command display COUNT source lines (unless the ‘list’ argument explicitly specifies some other number). Setting COUNT to ‘unlimited’ or 0 means there's no limit. ‘show listsize’ Display the number of lines that ‘list’ prints. Repeating a ‘list’ command with discards the argument, so it is equivalent to typing just ‘list’. This is more useful than listing the same lines again. An exception is made for an argument of ‘-’; that d7836 1 a7836 1 In general, the ‘list’ command expects you to supply zero, one or two d7842 1 a7842 1 Here is a complete description of the possible arguments for ‘list’: d7844 1 a7844 1 ‘list LOCSPEC’ d7848 1 a7848 1 ‘list FIRST,LAST’ d7850 1 a7850 1 When a ‘list’ command has two location specs, and the source file d7857 1 a7857 1 ‘list ,LAST’ d7864 1 a7864 1 ‘list FIRST,’ d7867 1 a7867 1 ‘list +’ d7870 1 a7870 1 ‘list -’ d7873 1 a7873 1 ‘list’ d7887 1 a7887 1 “location specification”, or “location spec”. This section documents d7891 1 a7891 1 program, known as “code location”, that corresponds to the given d7893 1 a7893 1 corresponding to a location spec “location resolution”. d7916 1 a7916 1 • The location spec specifies a function name, and there are several d7919 1 a7919 1 function name, such as ‘A::func(int)’ instead of just ‘func’.) d7921 1 a7921 1 • The location spec specifies a source file name, and there are d7927 1 a7927 1 • For a C++ constructor, the GCC compiler generates several instances d7931 1 a7931 1 • For a C++ template function, a given line in the function can d7934 1 a7934 1 • For an inlined function, a given source line can correspond to d7941 1 a7941 1 • Some parts of the program lack detailed enough debug info, so the d7948 1 a7948 1 • The location spec specifies a function name, and there are no d7952 1 a7952 1 • The location spec specifies a source file name, and there are no d7956 1 a7956 1 • The location spec specifies both a source file name and a source d7977 1 a7977 1 A “linespec” is a colon-separated list of source location parameters d7981 1 a7981 1 ‘LINENUM’ d7984 4 a7987 4 ‘-OFFSET’ ‘+OFFSET’ Specifies the line OFFSET lines before or after the “current line”. For the ‘list’ command, the current line is the last one printed; d7989 1 a7989 1 stopped in the currently selected “stack frame” (*note Frames: d7991 1 a7991 1 second of the two linespecs in a ‘list’ command, this specifies the d7994 1 a7994 1 ‘FILENAME:LINENUM’ d7998 3 a8000 3 FILENAME is ‘gcc/expr.c’, then it will match source file name of ‘/build/trunk/gcc/expr.c’, but not ‘/build/trunk/libcpp/expr.c’ or ‘/build/trunk/gcc/x-expr.c’. d8002 1 a8002 1 ‘FUNCTION’ d8010 2 a8011 2 For example, assuming a program with C++ symbols named ‘A::B::func’ and ‘B::func’, both commands ‘break func’ and ‘break B::func’ set a d8015 3 a8017 3 ‘-qualified’ option. For example, ‘break -qualified func’ sets a breakpoint on a free-function named ‘func’ ignoring any C++ class methods and namespace functions called ‘func’. d8021 1 a8021 1 ‘FUNCTION:LABEL’ d8024 1 a8024 1 ‘FILENAME:FUNCTION’ d8030 1 a8030 1 ‘LABEL’ d8036 2 a8037 2 ‘-pstap|-probe-stap [OBJFILE:[PROVIDER:]]NAME’ The GNU/Linux tool ‘SystemTap’ provides a way for applications to d8054 1 a8054 1 “Explicit locations” allow the user to directly specify the source d8063 3 a8065 3 For example, the linespec ‘foo:bar’ may refer to a function ‘bar’ defined in the file named ‘foo’ or the label ‘bar’ in a function named ‘foo’. GDB must search either the file system or the symbol table to d8071 1 a8071 1 ‘-source FILENAME’ d8075 1 a8075 1 ‘foo/bar/baz.c’. Otherwise GDB will use the first file it finds d8077 1 a8077 1 ‘-function’ or ‘-line’. d8079 1 a8079 1 ‘-function FUNCTION’ d8081 1 a8081 1 locations unmodified by other options (such as ‘-label’ or ‘-line’) d8089 3 a8091 3 For example, assuming a program with C++ symbols named ‘A::B::func’ and ‘B::func’, both commands ‘break -function func’ and ‘break -function B::func’ set a breakpoint on both symbols. d8093 1 a8093 1 You can use the ‘-qualified’ flag to override this (see below). d8095 1 a8095 1 ‘-qualified’ d8098 1 a8098 1 ‘-function’ as a complete fully-qualified name. d8100 3 a8102 3 For example, assuming a C++ program with symbols named ‘A::B::func’ and ‘B::func’, the ‘break -qualified -function B::func’ command sets a breakpoint on ‘B::func’, only. d8104 1 a8104 1 (Note: the ‘-qualified’ option can precede a linespec as well d8106 1 a8106 1 be simplified as ‘break -qualified B::func’.) d8108 1 a8108 1 ‘-label LABEL’ d8113 1 a8113 1 ‘-line NUMBER’ d8115 1 a8115 1 either be absolute (‘-line 3’) or relative (‘-line +3’), depending d8121 1 a8121 1 ‘break -s main.c -li 3’. d8129 1 a8129 1 “Address locations” indicate a specific program address. They have the d8132 2 a8133 2 For line-oriented commands, such as ‘list’ and ‘edit’, this specifies a source line that contains ADDRESS. For ‘break’ and other d8145 1 a8145 1 ‘EXPRESSION’ d8148 1 a8148 1 ‘FUNCADDR’ d8152 2 a8153 2 valid expression). In Pascal and Modula-2, this is ‘&FUNCTION’. In Ada, this is ‘FUNCTION'Address’ (although the Pascal form also d8159 1 a8159 1 ‘'FILENAME':FUNCADDR’ d8171 1 a8171 1 To edit the lines in a source file, use the ‘edit’ command. The editing d8177 1 a8177 1 ‘edit LOCSPEC’ d8179 2 a8180 2 resolving ‘locspec’. Editing starts at the source file and source line ‘locspec’ resolves to. *Note Location Specifications::, for d8183 1 a8183 1 If ‘locspec’ resolves to more than one source line in your program, d8187 1 a8187 1 Here are the forms of the ‘edit’ command most commonly used: d8189 1 a8189 1 ‘edit NUMBER’ d8193 1 a8193 1 ‘edit FUNCTION’ d8201 3 a8203 3 ‘/bin/ex’, but you can change this by setting the environment variable ‘EDITOR’ before using GDB. For example, to configure GDB to use the ‘vi’ editor, you could use these commands with the ‘sh’ shell: d8207 1 a8207 1 or in the ‘csh’ shell, d8213 1 a8213 1 (1) The only restriction is that your editor (say ‘ex’), recognizes d8228 3 a8230 3 ‘forward-search REGEXP’ ‘search REGEXP’ The command ‘forward-search REGEXP’ checks each line, starting with d8232 2 a8233 2 lists the line that is found. You can use the synonym ‘search REGEXP’ or abbreviate the command name as ‘fo’. d8235 2 a8236 2 ‘reverse-search REGEXP’ The command ‘reverse-search REGEXP’ checks each line, starting with d8239 1 a8239 1 this command as ‘rev’. d8251 1 a8251 1 files; this is called the “source path”. Each time GDB wants a source d8256 2 a8257 2 ‘/usr/src/foo-1.0/lib/foo.c’, does not record a compilation directory, and the “source path” is ‘/mnt/cross’. GDB would look for the source d8260 3 a8262 3 1. ‘/usr/src/foo-1.0/lib/foo.c’ 2. ‘/mnt/cross/usr/src/foo-1.0/lib/foo.c’ 3. ‘/mnt/cross/foo.c’ d8266 1 a8266 1 name, such as ‘/mnt/cross/src/foo-1.0/lib/foo.c’. Likewise, the d8268 2 a8269 2 is ‘/mnt/cross’, and the binary refers to ‘foo.c’, GDB would not find it under ‘/mnt/cross/usr/src/foo-1.0/lib’. d8274 2 a8275 2 “source path” is ‘/mnt/cross’, the source file is recorded as ‘../lib/foo.c’, and no compilation directory is recorded, then GDB will d8278 2 a8279 2 1. ‘/mnt/cross/../lib/foo.c’ 2. ‘/mnt/cross/foo.c’ d8281 2 a8282 2 The “source path” will always include two special entries ‘$cdir’ and ‘$cwd’, these refer to the compilation directory (if one is recorded) d8285 1 a8285 1 ‘$cdir’ causes GDB to search within the compilation directory, if one d8287 1 a8287 1 recorded in the debug information then ‘$cdir’ is ignored. d8289 1 a8289 1 ‘$cwd’ is not the same as ‘.’--the former tracks the current working d8295 3 a8297 3 GDB has not found the source file after the first search using “source path”, then GDB will combine the compilation directory and the filename, and then search for the source file again using the “source path”. d8300 3 a8302 3 ‘/usr/src/foo-1.0/lib/foo.c’, the compilation directory is recorded as ‘/project/build’, and the “source path” is ‘/mnt/cross:$cdir:$cwd’ while the current working directory of the GDB session is ‘/home/user’, then d8305 10 a8314 10 1. ‘/usr/src/foo-1.0/lib/foo.c’ 2. ‘/mnt/cross/usr/src/foo-1.0/lib/foo.c’ 3. ‘/project/build/usr/src/foo-1.0/lib/foo.c’ 4. ‘/home/user/usr/src/foo-1.0/lib/foo.c’ 5. ‘/mnt/cross/project/build/usr/src/foo-1.0/lib/foo.c’ 6. ‘/project/build/project/build/usr/src/foo-1.0/lib/foo.c’ 7. ‘/home/user/project/build/usr/src/foo-1.0/lib/foo.c’ 8. ‘/mnt/cross/foo.c’ 9. ‘/project/build/foo.c’ 10. ‘/home/user/foo.c’ d8322 1 a8322 1 absolute paths start with a drive letter (e.g. ‘C:/project/foo.c’), GDB d8324 3 a8326 3 search directory from “source path”; for instance if the executable references the source file ‘C:/project/foo.c’ and “source path” is set to ‘D:/mnt/cross’, then GDB will search in the following locations for d8329 3 a8331 3 1. ‘C:/project/foo.c’ 2. ‘D:/mnt/cross/project/foo.c’ 3. ‘D:/mnt/cross/foo.c’ d8340 2 a8341 2 When you start GDB, its source path includes only ‘$cdir’ and ‘$cwd’, in that order. To add other directories, use the ‘directory’ command. d8344 1 a8344 1 script files (read using the ‘-command’ option and ‘source’ command). d8347 1 a8347 1 manage a list of source path substitution rules. A “substitution rule” d8358 6 a8363 6 Using the previous example, suppose the ‘foo-1.0’ tree has been moved from ‘/usr/src’ to ‘/mnt/cross’, then you can tell GDB to replace ‘/usr/src’ in all source path names with ‘/mnt/cross’. The first lookup will then be ‘/mnt/cross/foo-1.0/lib/foo.c’ in place of the original location of ‘/usr/src/foo-1.0/lib/foo.c’. To define a source path substitution rule, use the ‘set substitute-path’ command (*note set d8368 2 a8369 2 instance, a rule substituting ‘/usr/source’ into ‘/mnt/cross’ will be applied to ‘/usr/source/foo-1.0’ but not to ‘/usr/sourceware/foo-2.0’. d8372 1 a8372 1 ‘/root/usr/source/baz.c’ either. d8374 2 a8375 2 In many cases, you can achieve the same result using the ‘directory’ command. However, ‘set substitute-path’ can be more efficient in the d8377 1 a8377 1 subdirectories. With the ‘directory’ command, you need to add each d8379 1 a8379 1 preserving its internal organization, then ‘set substitute-path’ allows d8382 1 a8382 1 ‘set substitute-path’ is also more than just a shortcut command. The d8384 1 a8384 1 exists. On the other hand, ‘set substitute-path’ modifies the debugger d8391 1 a8391 1 configuring GDB with the ‘--with-relocated-sources=DIR’ option. The DIR d8393 1 a8393 1 with ‘--prefix’ or ‘--exec-prefix’), and directory names in debug d8399 2 a8400 2 ‘directory DIRNAME ...’ ‘dir DIRNAME ...’ d8402 2 a8403 2 directory names may be given to this command, separated by ‘:’ (‘;’ on MS-DOS and MS-Windows, where ‘:’ usually appears as part of d8408 2 a8409 2 The special strings ‘$cdir’ (to refer to the compilation directory, if one is recorded), and ‘$cwd’ (to refer to the current working d8414 2 a8415 2 ‘directory’ Reset the source path to its default value (‘$cdir:$cwd’ on Unix d8418 2 a8419 2 ‘set directories PATH-LIST’ Set the source path to PATH-LIST. ‘$cdir:$cwd’ are added if d8422 1 a8422 1 ‘show directories’ d8425 1 a8425 1 ‘set substitute-path FROM TO’ d8431 2 a8432 2 For example, if the file ‘/foo/bar/baz.c’ was moved to ‘/mnt/cross/baz.c’, then the command d8436 2 a8437 2 will tell GDB to replace ‘/foo/bar’ with ‘/mnt/cross’, which will allow GDB to find the file ‘baz.c’ even though it was moved. d8449 4 a8452 4 GDB would then rewrite ‘/usr/src/include/defs.h’ into ‘/mnt/include/defs.h’ by using the first rule. However, it would use the second rule to rewrite ‘/usr/src/lib/foo.c’ into ‘/mnt/src/lib/foo.c’. d8454 1 a8454 1 ‘unset substitute-path [path]’ d8462 1 a8462 1 ‘show substitute-path [path]’ d8473 1 a8473 1 1. Use ‘directory’ with no argument to reset the source path to its d8476 1 a8476 1 2. Use ‘directory’ with suitable arguments to reinstall the d8486 2 a8487 2 You can use the command ‘info line’ to map source lines to program addresses (and vice versa), and the command ‘disassemble’ to display a d8489 4 a8492 4 ‘set disassemble-next-line’ to set whether to disassemble next source line when execution stops. When run under GNU Emacs mode, the ‘info line’ command causes the arrow to point to the line specified. Also, ‘info line’ prints addresses in symbolic form as well as hex. d8494 2 a8495 2 ‘info line’ ‘info line LOCSPEC’ d8502 2 a8503 2 For example, we can use ‘info line’ to discover the location of the object code for the first line of function ‘m4_changequote’: d8509 1 a8509 1 We can also inquire, using ‘*ADDR’ as the form for LOCSPEC, what source d8515 2 a8516 2 After ‘info line’, the default address for the ‘x’ command is changed to the starting address of the line, so that ‘x/i’ is sufficient to d8519 1 a8519 1 ‘$_’ (*note Convenience Variables: Convenience Vars.). d8521 1 a8521 1 After ‘info line’, using ‘info line’ again without specifying a d8524 5 a8528 5 ‘disassemble’ ‘disassemble /m’ ‘disassemble /s’ ‘disassemble /r’ ‘disassemble /b’ d8531 2 a8532 2 specifying the ‘/m’ or ‘/s’ modifier and print the raw instructions in hex as well as in symbolic form by specifying the ‘/r’ or ‘/b’ d8535 1 a8535 1 Only one of ‘/m’ and ‘/s’ can be used, attempting to use both flag d8538 1 a8538 1 Only one of ‘/r’ and ‘/b’ can be used, attempting to use both flag d8548 1 a8548 1 ‘START,END’ d8550 2 a8551 2 ‘START,+LENGTH’ the addresses from START (inclusive) to ‘START+LENGTH’ d8559 1 a8559 1 such as ‘0x32c4’, ‘&main+10’ or ‘$pc - 8’. d8562 1 a8562 1 counter, the instruction at that location is shown with a ‘=>’ d8581 1 a8581 1 difference between the ‘/r’ and ‘/b’ modifiers. First with ‘/b’, the d8592 1 a8592 1 In contrast, with ‘/r’ the bytes of the instruction are displayed in d8605 1 a8605 1 ‘/m’ or ‘/s’, when the program is stopped just after function prologue d8629 2 a8630 2 The ‘/m’ option is deprecated as its output is not useful when there is either inlined code or re-ordered code. The ‘/s’ option is the d8632 1 a8632 1 difference between ‘/m’ output and ‘/s’ output. This example has one d8634 2 a8635 2 ‘-O2’ optimization. Note how the ‘/m’ output is missing the disassembly of several instructions that are present in the ‘/s’ output. d8637 1 a8637 1 ‘foo.h’: d8649 1 a8649 1 ‘foo.c’: d8722 1 a8722 1 Note that the ‘disassemble’ command's address arguments are specified d8725 3 a8727 3 So, for example, if you want to disassemble function ‘bar’ in file ‘foo.c’, you must type ‘disassemble 'foo.c'::bar’ and not ‘disassemble foo.c:bar’. d8738 1 a8738 1 ‘set disassembler-options OPTION1[,OPTION2...]’ d8741 2 a8742 2 ‘-M’/‘--disassembler-options’ section of the ‘objdump’ manual and/or the output of ‘objdump --help’ (*note objdump: d8750 1 a8750 1 ‘show disassembler-options’ d8753 1 a8753 1 ‘set disassembly-flavor INSTRUCTION-SET’ d8755 1 a8755 1 via the ‘disassemble’ or ‘x/i’ commands. d8758 2 a8759 2 You can set INSTRUCTION-SET to either ‘intel’ or ‘att’. The default is ‘att’, the AT&T flavor used by default by Unix d8762 1 a8762 1 ‘show disassembly-flavor’ d8765 2 a8766 2 ‘set disassemble-next-line’ ‘show disassemble-next-line’ d8795 3 a8797 3 ‘set source open [on|off]’ ‘show source open’ When this option is ‘on’, which is the default, GDB will access d8799 1 a8799 1 when GDB stops, or in response to the ‘list’ command. d8801 1 a8801 1 When this option is ‘off’, GDB will not access source code files. d8809 2 a8810 2 The usual way to examine data in your program is with the ‘print’ command (abbreviated ‘p’), or its synonym ‘inspect’. It evaluates and d8816 2 a8817 2 ‘print [[OPTIONS] --] EXPR’ ‘print [[OPTIONS] --] /F EXPR’ d8820 1 a8820 1 you can choose a different format by specifying ‘/F’, where F is a d8824 2 a8825 2 The ‘print’ command supports a number of options that allow overriding relevant global print settings as set by ‘set print’ d8828 1 a8828 1 ‘-address [on|off]’ d8832 1 a8832 1 ‘-array [on|off]’ d8836 1 a8836 1 ‘-array-indexes [on|off]’ d8840 2 a8841 2 ‘-characters NUMBER-OF-CHARACTERS|elements|unlimited’ Set limit on string characters to print. The value ‘elements’ d8843 1 a8843 1 value ‘unlimited’ causes there to be no limit. Related d8846 1 a8846 1 ‘-elements NUMBER-OF-ELEMENTS|unlimited’ d8849 2 a8850 2 ‘-characters’ option above for when this option applies to strings. The value ‘unlimited’ causes there to be no limit. d8853 1 a8853 1 ‘-max-depth DEPTH|unlimited’ d8857 1 a8857 1 ‘-nibbles [on|off]’ d8861 1 a8861 1 ‘-memory-tag-violations [on|off]’ d8865 1 a8865 1 ‘-null-stop [on|off]’ d8869 1 a8869 1 ‘-object [on|off]’ d8873 1 a8873 1 ‘-pretty [on|off]’ d8877 1 a8877 1 ‘-raw-values [on|off]’ d8882 2 a8883 2 ‘-repeats NUMBER-OF-REPEATS|unlimited’ Set threshold for repeated print elements. ‘unlimited’ causes d8887 1 a8887 1 ‘-static-members [on|off]’ d8891 1 a8891 1 ‘-symbol [on|off]’ d8895 1 a8895 1 ‘-union [on|off]’ d8899 1 a8899 1 ‘-vtbl [on|off]’ d8903 1 a8903 1 Because the ‘print’ command accepts arbitrary expressions which may d8905 1 a8905 1 command option, then you must use a double dash (‘--’) to mark the d8908 1 a8908 1 For example, this prints the value of the ‘-p’ expression: d8913 1 a8913 1 with the ‘-pretty’ option in effect: d8929 2 a8930 2 ‘print [OPTIONS]’ ‘print [OPTIONS] /F’ d8932 1 a8932 1 “value history”; *note Value History: Value History.). This allows d8936 1 a8936 1 If the architecture supports memory tagging, the ‘print’ command will d8940 1 a8940 1 A more low-level way of examining data is with the ‘x’ command. It d8945 2 a8946 2 fields of a struct or a class are declared, use the ‘ptype EXPR’ command rather than ‘print’. *Note Examining the Symbol Table: Symbols. d8949 2 a8950 2 is through the Python extension command ‘explore’ (available only if the GDB build is configured with ‘--with-python’). It offers an interactive d8956 1 a8956 1 ‘explore ARG’ d8960 2 a8961 2 The working of the ‘explore’ command can be illustrated with an example. If a data type ‘struct ComplexStruct’ is defined in your C d8981 1 a8981 1 then, the value of the variable ‘cs’ can be explored using the ‘explore’ d8993 1 a8993 1 Since the fields of ‘cs’ are not scalar values, you are being prompted d8995 1 a8995 1 ‘ss_p’ by entering ‘0’. Then, since this field is a pointer, you will d8997 2 a8998 2 ‘cs’ above, it is indeed pointing to a single value, hence you enter ‘y’. If you enter ‘n’, then you will be asked if it were pointing to an d9012 1 a9012 1 If the field ‘arr’ of ‘cs’ was chosen for exploration by entering ‘1’ d9030 1 a9030 1 Similar to exploring values, you can use the ‘explore’ command to d9034 2 a9035 2 same example as above, your can explore the type ‘struct ComplexStruct’ by passing the argument ‘struct ComplexStruct’ to the ‘explore’ command. d9040 2 a9041 2 session, you can explore the type ‘struct ComplexStruct’ in a manner similar to how the value ‘cs’ was explored in the above example. d9043 2 a9044 2 The ‘explore’ command also has two sub-commands, ‘explore value’ and ‘explore type’. The former sub-command is a way to explicitly specify d9049 2 a9050 2 ‘explore value EXPR’ This sub-command of ‘explore’ explores the value of the expression d9053 1 a9053 1 to that of the behavior of the ‘explore’ command being passed the d9056 2 a9057 2 ‘explore type ARG’ This sub-command of ‘explore’ explores the type of ARG (if ARG is a d9062 1 a9062 1 ‘explore’ command being passed the argument ARG. If ARG is an d9064 1 a9064 1 that of the ‘explore’ command being passed the type of ARG as the d9101 1 a9101 1 ‘print’ and many other GDB commands accept an expression and compute its d9110 1 a9110 1 ‘print {1, 2, 3}’ to create an array of three integers. If you pass an d9112 1 a9112 1 array to memory that is ‘malloc’ed in the target program. d9128 2 a9129 2 ‘@@’ ‘@@’ is a binary operator for treating parts of memory as arrays. d9132 2 a9133 2 ‘::’ ‘::’ allows you to specify a variable in terms of the file or d9136 1 a9136 1 ‘{TYPE} ADDR’ d9152 2 a9153 2 application in different contexts. This is called “overloading”. Another example involving Ada is generics. A “generic package” is d9159 2 a9160 2 specify the signature of the function you want to break on, as in ‘break FUNCTION(TYPES)’. In Ada, using the fully qualified name of your d9165 2 a9166 2 possibility, and then waits for the selection with the prompt ‘>’. The first option is always ‘[0] cancel’, and typing ‘0 ’ aborts the d9168 2 a9169 2 more than one choice to be selected, the next option in the menu is ‘[1] all’, and typing ‘1 ’ selects all possible choices. d9172 1 a9172 1 breakpoint at the overloaded symbol ‘String::after’. We choose three d9193 1 a9193 1 ‘set multiple-symbols MODE’ d9198 1 a9198 1 By default, MODE is set to ‘all’. If the command with which the d9207 1 a9207 1 When MODE is set to ‘ask’, the debugger always uses the menu when d9210 1 a9210 1 Finally, when MODE is set to ‘cancel’, the debugger reports an d9213 2 a9214 2 ‘show multiple-symbols’ Show the current value of the ‘multiple-symbols’ setting. d9228 1 a9228 1 • global (or file-static) d9232 1 a9232 1 • visible according to the scope rules of the programming language d9247 3 a9249 3 you can examine and use the variable ‘a’ whenever your program is executing within the function ‘foo’, but you can only use or examine the variable ‘b’ while your program is executing inside the block where ‘b’ d9258 1 a9258 1 using the colon-colon (‘::’) notation: d9266 1 a9266 1 global value of ‘x’ defined in ‘f2.c’: d9270 1 a9270 1 The ‘::’ notation is normally used for referring to static variables, d9293 1 a9293 1 ‘bar(0)’: d9306 1 a9306 1 These uses of ‘::’ are very rarely in conflict with the very similar d9312 2 a9313 2 that has a field named ‘includefile’, and there is also an include file named ‘includefile’ that defines a variable, ‘some_global’. d9355 1 a9355 1 information, GDB will say ‘’. *Note incomplete type: d9370 1 a9370 1 If you append ‘@@entry’ string to a function parameter name you get d9385 5 a9389 5 Strings are identified as arrays of ‘char’ values without specified signedness. Arrays of either ‘signed char’ or ‘unsigned char’ get printed as arrays of 1 byte sized integers. ‘-fsigned-char’ or ‘-funsigned-char’ GCC options have no effect as GDB defines literal string type ‘"char"’ as ‘char’ without a sign. For program code d9411 2 a9412 2 “artificial array”, using the binary operator ‘@@’. The left operand of ‘@@’ should be the first element of the desired array and be an d9422 1 a9422 1 you can print the contents of ‘array’ with d9426 2 a9427 2 The left operand of ‘@@’ must reside in memory. Array values made with ‘@@’ in this way behave just like other arrays in terms of d9439 2 a9440 2 ‘(TYPE[])VALUE’) GDB calculates the size to fill the value (as ‘sizeof(VALUE)/sizeof(TYPE)’: d9451 2 a9452 2 you have an array ‘dtab’ of pointers to structures, and you are interested in the values of a field ‘fv’ in each structure. Here is an d9471 1 a9471 1 instruction. To do these things, specify an “output format” when you d9475 1 a9475 1 already computed. This is done by starting the arguments of the ‘print’ d9479 1 a9479 1 ‘x’ d9482 1 a9482 1 ‘d’ d9485 1 a9485 1 ‘u’ d9489 1 a9489 1 ‘o’ d9492 1 a9492 1 ‘t’ d9494 1 a9494 1 ‘t’ stands for "two". (1) d9496 1 a9496 1 ‘a’ d9504 1 a9504 1 The command ‘info symbol 0x54320’ yields similar results. *Note d9507 1 a9507 1 ‘c’ d9512 1 a9512 1 octal escape ‘\nnn’ for characters outside the 7-bit ASCII range. d9514 2 a9515 2 Without this format, GDB displays ‘char’, ‘unsigned char’, and ‘signed char’ data as character constants. Single-byte members of d9518 1 a9518 1 ‘f’ d9522 1 a9522 1 ‘s’ d9528 2 a9529 2 Without this format, GDB displays pointers to and arrays of ‘char’, ‘unsigned char’, and ‘signed char’ as strings. Single-byte members d9532 2 a9533 2 ‘z’ Like ‘x’ formatting, the value is treated as an integer and printed d9537 2 a9538 2 ‘r’ Print using the ‘raw’ formatting. By default, GDB will use a d9541 1 a9541 1 the value's contents. The ‘r’ format bypasses any Python d9553 2 a9554 2 format, you can use the ‘print’ command with just a format and no expression. For example, ‘p/x’ reprints the last value in hex. d9558 2 a9559 2 (1) ‘b’ cannot be used because these format letters are also used with the ‘x’ command, where ‘b’ stands for "byte"; see *note Examining d9568 1 a9568 1 You can use the command ‘x’ (for "examine") to examine memory in any of d9571 4 a9574 4 ‘x/NFU ADDR’ ‘x ADDR’ ‘x’ Use the ‘x’ command to examine memory. d9579 1 a9579 1 for NFU, you need not type the slash ‘/’. Several commands set d9589 3 a9591 3 The display format is one of the formats used by ‘print’ (‘x’, ‘d’, ‘u’, ‘o’, ‘t’, ‘a’, ‘c’, ‘f’, ‘s’), ‘i’ (for machine instructions) and ‘m’ (for displaying memory tags). The default is ‘x’ d9593 1 a9593 1 either ‘x’ or ‘print’. d9598 1 a9598 1 ‘b’ d9600 1 a9600 1 ‘h’ d9602 1 a9602 1 ‘w’ d9604 1 a9604 1 ‘g’ d9607 6 a9612 6 Each time you specify a unit size with ‘x’, that size becomes the default unit the next time you use ‘x’. For the ‘i’ format, the unit size is ignored and is normally not written. For the ‘s’ format, the unit size defaults to ‘b’, unless it is explicitly given. Use ‘x /hs’ to display 16-bit char strings and ‘x /ws’ to display 32-bit strings. The next use of ‘x /s’ will again display d9615 1 a9615 1 the ‘s’ modifier will use the UTF-16 encoding while ‘w’ will use d9626 9 a9634 9 address: ‘info breakpoints’ (to the address of the last breakpoint listed), ‘info line’ (to the starting address of a line), and ‘print’ (if you use it to display a value from memory). For example, ‘x/3uh 0x54320’ is a request to display three halfwords (‘h’) of memory, formatted as unsigned decimal integers (‘u’), starting at address ‘0x54320’. ‘x/4xw $sp’ prints the four words (‘w’) of memory above the stack pointer (here, ‘$sp’; *note Registers: Registers.) in hexadecimal (‘x’). d9637 2 a9638 2 backward from the given address. For example, ‘x/-3uh 0x54320’ prints three halfwords (‘h’) at ‘0x5431a’, ‘0x5431c’, and ‘0x5431e’. d9643 2 a9644 2 specifications ‘4xw’ and ‘4wx’ mean exactly the same thing. (However, the count N must come first; ‘wx4’ does not work.) d9646 2 a9647 2 Even though the unit size U is ignored for the formats ‘s’ and ‘i’, you might still want to use a count N; for example, ‘3i’ specifies that d9649 1 a9649 1 convenience, especially when used with the ‘display’ command, the ‘i’ d9652 1 a9652 1 within the count. The command ‘disassemble’ gives an alternative way of d9656 1 a9656 1 If a negative repeat count is specified for the formats ‘s’ or ‘i’, d9659 1 a9659 1 the ‘i’ format, we use line number information in the debug info to d9664 1 a9664 1 All the defaults for the arguments to ‘x’ are designed to make it d9666 3 a9668 3 you use ‘x’. For example, after you have inspected three machine instructions with ‘x/3i ADDR’, you can inspect the next seven with just ‘x/7’. If you use to repeat the ‘x’ command, the repeat count N d9670 1 a9670 1 ‘x’. d9673 1 a9673 1 program counter is shown with a ‘=>’ marker. For example: d9683 1 a9683 1 displayed by using ‘m’. *Note Memory Tagging::. d9689 1 a9689 1 Due to the way GDB prints information with the ‘x’ command (not d9692 1 a9692 1 boundary is crossed in the middle of a line displayed by the ‘x’ d9695 2 a9696 2 The ‘m’ format doesn't affect any other specified formats that were passed to the ‘x’ command. d9698 1 a9698 1 The addresses and contents printed by the ‘x’ command are not saved d9702 2 a9703 2 ‘$_’ and ‘$__’. After an ‘x’ command, the last address examined is available for use in expressions in the convenience variable ‘$_’. The d9705 1 a9705 1 variable ‘$__’. d9707 1 a9707 1 If the ‘x’ command has a repeat count, the address and contents saved d9715 1 a9715 1 and this document, the term “addressable memory unit” (or “memory unit” d9717 1 a9717 1 size. The word “byte” is used to refer to a chunk of data of 8 bits, d9726 1 a9726 1 ‘compare-sections’ command is provided for such situations. d9728 1 a9728 1 ‘compare-sections [SECTION-NAME|-r]’ d9733 1 a9733 1 ‘-r’, compares all loadable read-only sections. d9768 1 a9768 1 The ‘print’ (*note Data::) and ‘x’ (*note Memory::) commands will d9770 1 a9770 1 ‘memory-tag’ gives access to the various memory tagging commands. d9772 1 a9772 1 The ‘memory-tag’ commands are the following: d9774 1 a9774 1 ‘memory-tag print-logical-tag POINTER_EXPRESSION’ d9776 1 a9776 1 ‘memory-tag with-logical-tag POINTER_EXPRESSION TAG_BYTES’ d9779 1 a9779 1 ‘memory-tag print-allocation-tag ADDRESS_EXPRESSION’ d9782 1 a9782 1 ‘memory-tag setatag STARTING_ADDRESS LENGTH TAG_BYTES’ d9785 1 a9785 1 ‘memory-tag check POINTER_EXPRESSION’ d9804 2 a9805 2 (to see how it changes), you might want to add it to the “automatic display list” so that GDB prints its value each time your program stops. d9814 5 a9818 5 As with displays you request manually using ‘x’ or ‘print’, you can specify the output format you prefer; in fact, ‘display’ decides whether to use ‘print’ or ‘x’ depending your format specification--it uses ‘x’ if you specify either the ‘i’ or ‘s’ format, or a unit size; otherwise it uses ‘print’. d9820 1 a9820 1 ‘display EXPR’ d9824 1 a9824 1 ‘display’ does not repeat if you press again after using it. d9826 1 a9826 1 ‘display/FMT EXPR’ d9832 2 a9833 2 ‘display/FMT ADDR’ For FMT ‘i’ or ‘s’, or including a unit-size or a number of units, d9835 2 a9836 2 time your program stops. Examining means in effect doing ‘x/FMT ADDR’. *Note Examining Memory: Memory. d9838 2 a9839 2 For example, ‘display/i $pc’ can be helpful, to see the machine instruction about to be executed each time execution stops (‘$pc’ is a d9842 2 a9843 2 ‘undisplay DNUMS...’ ‘delete display DNUMS...’ d9847 2 a9848 2 numbers shown in the first field of the ‘info display’ display; or it could be a range of display numbers, as in ‘2-4’. d9850 2 a9851 2 ‘undisplay’ does not repeat if you press after using it. (Otherwise you would just get the error ‘No display number ...’.) d9853 1 a9853 1 ‘disable display DNUMS...’ d9859 2 a9860 2 ‘info display’ display; or it could be a range of display numbers, as in ‘2-4’. d9862 1 a9862 1 ‘enable display DNUMS...’ d9868 2 a9869 2 ‘info display’ display; or it could be a range of display numbers, as in ‘2-4’. d9871 1 a9871 1 ‘display’ d9875 1 a9875 1 ‘info display’ d9886 2 a9887 2 variables is not defined. For example, if you give the command ‘display last_char’ while inside a function with an argument ‘last_char’, GDB d9890 2 a9891 2 ‘last_char’--the display is disabled automatically. The next time your program stops where ‘last_char’ is meaningful, you can enable the d9905 2 a9906 2 ‘set print address’ ‘set print address on’ d9910 2 a9911 2 is ‘on’. For example, this is what a stack frame display looks like with ‘set print address on’: d9918 1 a9918 1 ‘set print address off’ d9920 2 a9921 2 example, this is the same stack frame displayed with ‘set print address off’: d9928 1 a9928 1 You can use ‘set print address off’ to eliminate all machine d9930 1 a9930 1 ‘print address off’, you should get the same text for backtraces on d9933 1 a9933 1 ‘show print address’ d9939 2 a9940 2 source file), you may need to clarify. One way to do this is with ‘info line’, for example ‘info line *0x4537’. Alternately, you can set GDB to d9943 1 a9943 1 ‘set print symbol-filename on’ d9947 1 a9947 1 ‘set print symbol-filename off’ d9951 1 a9951 1 ‘show print symbol-filename’ d9962 2 a9963 2 ‘set print max-symbolic-offset MAX-OFFSET’ ‘set print max-symbolic-offset unlimited’ d9966 1 a9966 1 than MAX-OFFSET. The default is ‘unlimited’, which tells GDB to d9968 1 a9968 1 it. Zero is equivalent to ‘unlimited’. d9970 1 a9970 1 ‘show print max-symbolic-offset’ d9974 3 a9976 3 If you have a pointer and you are not sure where it points, try ‘set print symbol-filename on’. Then you can determine the name and source file location of the variable where it points, using ‘p/a POINTER’. d9978 2 a9979 2 shows that a variable ‘ptt’ points at another variable ‘t’, defined in ‘hi2.c’: d9985 1 a9985 1 _Warning:_ For pointers that point to a local variable, ‘p/a’ does d9987 1 a9987 1 the appropriate ‘set print’ options turned on. d9989 2 a9990 2 You can also enable ‘/a’-like formatting all the time using ‘set print symbol on’: d9992 1 a9992 1 ‘set print symbol on’ d9996 1 a9996 1 ‘set print symbol off’ d10001 1 a10001 1 ‘show print symbol’ d10007 2 a10008 2 ‘set print array’ ‘set print array on’ d10012 1 a10012 1 ‘set print array off’ d10015 1 a10015 1 ‘show print array’ d10019 2 a10020 2 ‘set print array-indexes’ ‘set print array-indexes on’ d10026 1 a10026 1 ‘set print array-indexes off’ d10029 1 a10029 1 ‘show print array-indexes’ d10033 5 a10037 5 ‘set print nibbles’ ‘set print nibbles on’ Print binary values in groups of four bits, known as “nibbles”, when using the print command of GDB with the option ‘/t’. For example, this is what it looks like with ‘set print nibbles on’: d10044 1 a10044 1 ‘set print nibbles off’ d10047 1 a10047 1 ‘show print nibbles’ d10050 3 a10052 3 ‘set print characters NUMBER-OF-CHARACTERS’ ‘set print characters elements’ ‘set print characters unlimited’ d10055 1 a10055 1 printed the number of characters set by the ‘set print characters’ d10057 2 a10058 2 strings, that is for strings whose character type is ‘wchar_t’, ‘char16_t’, or ‘char32_t’ it is the number of actual characters d10060 1 a10060 1 controls. Setting NUMBER-OF-CHARACTERS to ‘elements’ means that d10063 1 a10063 1 NUMBER-OF-CHARACTERS to ‘unlimited’ means that the number of d10065 1 a10065 1 set to ‘elements’. d10067 1 a10067 1 ‘show print characters’ d10071 2 a10072 2 ‘set print elements NUMBER-OF-ELEMENTS’ ‘set print elements unlimited’ d10075 1 a10075 1 printed the number of elements set by the ‘set print elements’ d10078 1 a10078 1 limit is set to 200. Setting NUMBER-OF-ELEMENTS to ‘unlimited’ or d10082 5 a10086 5 ‘max-value-size’ (*note max-value-size: set max-value-size.), if the ‘print elements’ is set such that the size of the elements being printed is less than or equal to ‘max-value-size’, then GDB will print the array (up to the ‘print elements’ limit), and only ‘max-value-size’ worth of data will be added into the value history d10089 1 a10089 1 ‘show print elements’ d10093 1 a10093 1 ‘set print frame-arguments VALUE’ d10098 1 a10098 1 ‘all’ d10101 1 a10101 1 ‘scalars’ d10104 1 a10104 1 unions, etc, is replaced by ‘...’. This is the default. Here d10110 1 a10110 1 ‘none’ d10112 1 a10112 1 of each argument is replaced by ‘...’. In this case, the d10118 3 a10120 3 ‘presence’ Only the presence of arguments is indicated by ‘...’. The ‘...’ are not printed for function without any arguments. d10134 2 a10135 2 Setting ‘print frame-arguments’ to ‘scalars’ (the default), ‘none’ or ‘presence’ avoids this computation, thus speeding up the display d10138 1 a10138 1 ‘show print frame-arguments’ d10142 1 a10142 1 ‘set print raw-frame-arguments on’ d10145 1 a10145 1 ‘set print raw-frame-arguments off’ d10150 1 a10150 1 ‘show print raw-frame-arguments’ d10153 1 a10153 1 ‘set print entry-values VALUE’ d10161 4 a10164 4 The default value is ‘default’ (see below for its description). Older GDB behaved as with the setting ‘no’. Compilers not supporting this feature will behave in the ‘default’ setting the same way as with the ‘no’ setting. d10167 2 a10168 2 format and the compiler has to produce ‘DW_TAG_call_site’ tags. With GCC, you need to specify ‘-O -g’ during compilation, to get d10173 1 a10173 1 ‘no’ d10182 1 a10182 1 ‘only’ d10191 1 a10191 1 ‘preferred’ d10201 1 a10201 1 ‘if-needed’ d10211 1 a10211 1 ‘both’ d10221 1 a10221 1 ‘compact’ d10224 1 a10224 1 known, print for the actual value ‘’. If not d10226 1 a10226 1 identical, print the shortened ‘param=param@@entry=VALUE’ d10234 1 a10234 1 ‘default’ d10238 1 a10238 1 identical, print the shortened ‘param=param@@entry=VALUE’ d10249 1 a10249 1 ‘show print entry-values’ d10253 1 a10253 1 ‘set print frame-info VALUE’ d10257 2 a10258 2 that some other settings (such as ‘set print frame-arguments’ and ‘set print address’) are also influencing if and how some frame d10260 1 a10260 1 is never printed if ‘set print address’ is off. d10262 2 a10263 2 The possible values for ‘set print frame-info’ are: ‘short-location’ d10267 2 a10268 2 ‘location’ Same as ‘short-location’ but also print the source file and d10270 2 a10271 2 ‘location-and-address’ Same as ‘location’ but print the program counter even if d10273 1 a10273 1 ‘source-line’ d10276 3 a10278 3 ‘source-and-location’ Print what ‘location’ and ‘source-line’ are printing. ‘auto’ d10280 5 a10284 5 by the GDB command that prints a frame. For example, ‘frame’ prints the information printed by ‘source-and-location’ while ‘stepi’ will switch between ‘source-line’ and ‘source-and-location’ depending on the program counter. The default value is ‘auto’. d10286 2 a10287 2 ‘set print repeats NUMBER-OF-REPEATS’ ‘set print repeats unlimited’ d10290 2 a10291 2 array exceeds the threshold, GDB prints the string ‘""’, where N is the number of identical repetitions, instead d10293 1 a10293 1 threshold to ‘unlimited’ or zero will cause all elements to be d10296 1 a10296 1 ‘show print repeats’ d10300 2 a10301 2 ‘set print max-depth DEPTH’ ‘set print max-depth unlimited’ d10316 1 a10316 1 how ‘var’ is printed by GDB: d10318 1 a10318 1 DEPTH setting Result of ‘p var’ d10320 6 a10325 6 unlimited ‘$1 = {d = {c = {b = {a = 3}}}}’ ‘0’ ‘$1 = {...}’ ‘1’ ‘$1 = {d = {...}}’ ‘2’ ‘$1 = {d = {c = {...}}}’ ‘3’ ‘$1 = {d = {c = {b = {...}}}}’ ‘4’ ‘$1 = {d = {c = {b = {a = 3}}}}’ d10340 2 a10341 2 language, for most languages ‘{...}’ is used, but Fortran uses ‘(...)’. d10343 1 a10343 1 ‘show print max-depth’ d10347 2 a10348 2 ‘set print memory-tag-violations’ ‘set print memory-tag-violations on’ d10352 1 a10352 1 ‘set print memory-tag-violations off’ d10355 1 a10355 1 ‘show print memory-tag-violations’ d10359 1 a10359 1 ‘set print null-stop’ d10364 1 a10364 1 ‘show print null-stop’ d10368 1 a10368 1 ‘set print pretty on’ d10381 1 a10381 1 ‘set print pretty off’ d10389 1 a10389 1 ‘show print pretty’ d10392 1 a10392 1 ‘set print raw-values on’ d10396 1 a10396 1 ‘set print raw-values off’ d10403 1 a10403 1 ‘show print raw-values’ d10406 1 a10406 1 ‘set print sevenbit-strings on’ d10409 1 a10409 1 using the notation ‘\’NNN. This setting is best if you are working d10413 1 a10413 1 ‘set print sevenbit-strings off’ d10417 1 a10417 1 ‘show print sevenbit-strings’ d10420 1 a10420 1 ‘set print union on’ d10424 1 a10424 1 ‘set print union off’ d10426 1 a10426 1 other unions. GDB will print ‘"{...}"’ instead. d10428 1 a10428 1 ‘show print union’ d10449 1 a10449 1 with ‘set print union on’ in effect ‘p foo’ would print d10453 1 a10453 1 and with ‘set print union off’ in effect it would print d10457 1 a10457 1 ‘set print union’ affects programs written in C-like languages and d10462 2 a10463 2 ‘set print demangle’ ‘set print demangle on’ d10468 1 a10468 1 ‘show print demangle’ d10471 2 a10472 2 ‘set print asm-demangle’ ‘set print asm-demangle on’ d10477 1 a10477 1 ‘show print asm-demangle’ d10481 1 a10481 1 ‘set demangle-style STYLE’ d10487 1 a10487 1 ‘show demangle-style’ d10491 2 a10492 2 ‘set print object’ ‘set print object on’ d10502 1 a10502 1 ‘set print object off’ d10506 1 a10506 1 ‘show print object’ d10509 2 a10510 2 ‘set print static-members’ ‘set print static-members on’ d10514 1 a10514 1 ‘set print static-members off’ d10517 1 a10517 1 ‘show print static-members’ d10520 2 a10521 2 ‘set print pascal_static-members’ ‘set print pascal_static-members on’ d10525 1 a10525 1 ‘set print pascal_static-members off’ d10528 1 a10528 1 ‘show print pascal_static-members’ d10531 2 a10532 2 ‘set print vtbl’ ‘set print vtbl on’ d10534 2 a10535 2 (The ‘vtbl’ commands do not work on programs compiled with the HP ANSI C++ compiler (‘aCC’).) d10537 1 a10537 1 ‘set print vtbl off’ d10540 1 a10540 1 ‘show print vtbl’ d10572 1 a10572 1 The ‘info pretty-printer’ command will list all the installed d10574 1 a10574 1 multiple data types, then its “subprinters” are the printers for the d10578 1 a10578 1 Pretty-printers are installed by “registering” them with GDB. d10585 1 a10585 1 • Pretty-printers registered globally are available when debugging d10588 1 a10588 1 • Pretty-printers registered with a program space are available only d10592 1 a10592 1 • Pretty-printers registered with an objfile are loaded and unloaded d10608 1 a10608 1 Here is how a C++ ‘std::string’ looks without a pretty-printer: d10624 1 a10624 1 With a pretty-printer for ‘std::string’ only the contents are d10636 1 a10636 1 ‘info pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]’ d10641 1 a10641 1 pretty-printers to list. Objects can be ‘global’, the program d10650 1 a10650 1 ‘disable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]’ d10655 1 a10655 1 ‘enable pretty-printer [OBJECT-REGEXP [NAME-REGEXP]]’ d10661 3 a10663 3 named ‘foo’ that prints objects of type ‘foo’, and another from library2.so named ‘bar’ that prints two types of objects, ‘bar1’ and ‘bar2’. d10706 1 a10706 1 Note that for ‘bar’ the entire printer can be disabled, as can each d10712 1 a10712 1 The print option ‘-raw-values’ and GDB setting ‘set print raw-values’ d10716 2 a10717 2 Similarly, the backtrace option ‘-raw-frame-arguments’ and GDB setting ‘set print raw-frame-arguments’ (*note set print d10727 2 a10728 2 Values printed by the ‘print’ command are saved in the GDB “value history”. This allows you to refer to them in other expressions. d10730 1 a10730 1 example with the ‘file’ or ‘symbol-file’ commands). When the symbol d10734 3 a10736 3 The values printed are given “history numbers” by which you can refer to them. These are successive integers starting with one. ‘print’ shows you the history number assigned to a value by printing ‘$NUM = ’ d10739 6 a10744 6 To refer to any previous value, use ‘$’ followed by the value's history number. The way ‘print’ labels its output is designed to remind you of this. Just ‘$’ refers to the most recent value in the history, and ‘$$’ refers to the value before that. ‘$$N’ refers to the Nth value from the end; ‘$$2’ is the value just prior to ‘$$’, ‘$$1’ is equivalent to ‘$$’, and ‘$$0’ is equivalent to ‘$’. d10751 1 a10751 1 If you have a chain of structures where the component ‘next’ points d10760 1 a10760 1 of ‘x’ is 4 and you type these commands: d10765 2 a10766 2 then the value recorded in the value history by the ‘print’ command remains 4 even though the value of ‘x’ has changed. d10768 1 a10768 1 ‘show values’ d10770 2 a10771 2 numbers. This is like ‘p $$9’ repeated ten times, except that ‘show values’ does not change the history. d10773 1 a10773 1 ‘show values N’ d10776 1 a10776 1 ‘show values +’ d10778 1 a10778 1 more values are available, ‘show values +’ produces no display. d10780 2 a10781 2 Pressing to repeat ‘show values N’ has exactly the same effect as ‘show values +’. d10789 1 a10789 1 GDB provides “convenience variables” that you can use within GDB to hold d10795 2 a10796 2 Convenience variables are prefixed with ‘$’. Any name preceded by ‘$’ can be used for a convenience variable, unless it is one of the d10799 1 a10799 1 preceded by ‘$’. *Note Value History: Value History.) d10807 2 a10808 2 would save in ‘$foo’ the value contained in the object pointed to by ‘object_ptr’. d10811 1 a10811 1 value is ‘void’ until you assign a new value. You can alter the value d10820 1 a10820 1 ‘show convenience’ d10823 1 a10823 1 Abbreviated ‘show conv’. d10825 1 a10825 1 ‘init-if-undefined $VARIABLE = EXPRESSION’ d10848 2 a10849 2 ‘$_’ The variable ‘$_’ is automatically set by the ‘x’ command to the d10851 5 a10855 5 commands which provide a default address for ‘x’ to examine also set ‘$_’ to that address; these commands include ‘info line’ and ‘info breakpoint’. The type of ‘$_’ is ‘void *’ except when set by the ‘x’ command, in which case it is a pointer to the type of ‘$__’. d10857 2 a10858 2 ‘$__’ The variable ‘$__’ is automatically set by the ‘x’ command to the d10862 1 a10862 1 ‘$_exitcode’ d10865 1 a10865 1 and resets ‘$_exitsignal’ to ‘void’. d10867 1 a10867 1 ‘$_exitsignal’ d10870 1 a10870 1 resets ‘$_exitcode’ to ‘void’. d10873 2 a10874 2 exited (i.e., ‘$_exitcode’ is not ‘void’) or signalled (i.e., ‘$_exitsignal’ is not ‘void’), the convenience function ‘$_isvoid’ d10908 3 a10910 3 debugged has signalled, since it calls ‘raise’ and raises a ‘SIGALRM’ signal. If the program being debugged had not called ‘raise’, then GDB would report a normal exit: d10915 2 a10916 2 ‘$_exception’ The variable ‘$_exception’ is set to the exception object being d10920 2 a10921 2 ‘$_ada_exception’ The variable ‘$_ada_exception’ is set to the address of the d10925 2 a10926 2 ‘$_probe_argc’ ‘$_probe_arg0...$_probe_arg11’ d10929 2 a10930 2 ‘$_sdata’ The variable ‘$_sdata’ contains extra collected static tracepoint d10932 1 a10932 1 that ‘$_sdata’ could be empty, if not inspecting a trace buffer, or d10935 3 a10937 3 ‘$_siginfo’ The variable ‘$_siginfo’ contains extra signal information (*note extra signal information::). Note that ‘$_siginfo’ could be empty, d10939 1 a10939 1 it will be empty before you execute the ‘run’ command. d10941 2 a10942 2 ‘$_tlb’ The variable ‘$_tlb’ is automatically set when debugging d10944 1 a10944 1 gdbserver that supports the ‘qGetTIBAddr’ request. *Note General d10948 1 a10948 1 ‘$_inferior’ d10953 1 a10953 1 ‘$_thread’ d10956 1 a10956 1 ‘$_gthread’ d10960 1 a10960 1 ‘$_inferior_thread_count’ d10964 2 a10965 2 ‘$_gdb_major’ ‘$_gdb_minor’ d10969 1 a10969 1 value 12 for ‘$_gdb_minor’. These variables allow you to write d10973 3 a10975 3 ‘$_shell_exitcode’ ‘$_shell_exitsignal’ GDB commands such as ‘shell’ and ‘|’ are launching shell commands. d10977 1 a10977 1 variables ‘$_shell_exitcode’ and ‘$_shell_exitsignal’ according to d10979 2 a10980 2 set and used similarly to the variables ‘$_exitcode’ and ‘$_exitsignal’. d10988 1 a10988 1 GDB also supplies some “convenience functions”. These have a syntax d10993 1 a10993 1 These functions do not require GDB to be configured with ‘Python’ d10996 2 a10997 2 ‘$_isvoid (EXPR)’ Return one if the expression EXPR is ‘void’. Otherwise it returns d11000 2 a11001 2 A ‘void’ expression is an expression where the type of the result is ‘void’. For example, you can examine a convenience variable d11003 1 a11003 1 whether it is ‘void’: d11017 2 a11018 2 In the example above, we used ‘$_isvoid’ to check whether ‘$_exitcode’ is ‘void’ before and after the execution of the d11020 1 a11020 1 to be examined, therefore ‘$_exitcode’ is ‘void’. After the d11022 1 a11022 1 ‘$_exitcode’ is zero, which means that it is not ‘void’ anymore. d11024 1 a11024 1 The ‘void’ expression can also be a call of a function from the d11032 1 a11032 1 The result of calling it inside GDB is ‘void’: d11044 1 a11044 1 ‘$_gdb_setting_str (SETTING)’ d11046 1 a11046 1 setting that can be used in a ‘set’ or ‘show’ command (*note d11057 1 a11057 1 ‘$_gdb_setting (SETTING)’ d11061 11 a11071 11 The value type for boolean and auto boolean settings is ‘int’. The boolean values ‘off’ and ‘on’ are converted to the integer values ‘0’ and ‘1’. The value ‘auto’ is converted to the value ‘-1’. The value type for integer settings is either ‘unsigned int’ or ‘int’, depending on the setting. Some integer settings accept an ‘unlimited’ value. Depending on the setting, the ‘set’ command also accepts the value ‘0’ or the value ‘−1’ as a synonym for ‘unlimited’. For example, ‘set height unlimited’ is equivalent to ‘set height 0’. d11073 2 a11074 2 Some other settings that accept the ‘unlimited’ value use the value ‘0’ to literally mean zero. For example, ‘set history size 0’ d11076 1 a11076 1 For such settings, ‘−1’ is the synonym for ‘unlimited’. d11078 2 a11079 2 See the documentation of the corresponding ‘set’ command for the numerical value equivalent to ‘unlimited’. d11081 2 a11082 2 The ‘$_gdb_setting’ function converts the unlimited value to a ‘0’ or a ‘−1’ value according to what the ‘set’ command uses. d11106 3 a11108 3 ‘$_gdb_maint_setting_str (SETTING)’ Like the ‘$_gdb_setting_str’ function, but works with ‘maintenance set’ variables. d11110 2 a11111 2 ‘$_gdb_maint_setting (SETTING)’ Like the ‘$_gdb_setting’ function, but works with ‘maintenance set’ d11114 1 a11114 1 ‘$_shell (COMMAND-STRING)’ d11128 1 a11128 1 determined in the same way as for the ‘shell’ command. *Note Shell d11158 3 a11160 3 Note: unlike the ‘shell’ command, the ‘$_shell’ convenience function does not affect the ‘$_shell_exitcode’ and ‘$_shell_exitsignal’ convenience variables. d11162 1 a11162 1 The following functions require GDB to be configured with ‘Python’ d11165 1 a11165 1 ‘$_memeq(BUF1, BUF2, LENGTH)’ d11169 1 a11169 1 ‘$_regex(STR, REGEX)’ d11172 1 a11172 1 that specified by ‘Python’'s regular expression support. d11174 1 a11174 1 ‘$_streq(STR1, STR2)’ d11178 1 a11178 1 ‘$_strlen(STR)’ d11181 1 a11181 1 ‘$_caller_is(NAME[, NUMBER_OF_FRAMES])’ d11204 1 a11204 1 ‘$_caller_matches(REGEXP[, NUMBER_OF_FRAMES])’ d11211 1 a11211 1 ‘$_any_caller_is(NAME[, NUMBER_OF_FRAMES])’ d11218 1 a11218 1 This function differs from ‘$_caller_is’ in that this function d11220 1 a11220 1 specified by NUMBER_OF_FRAMES, whereas ‘$_caller_is’ only checks d11223 1 a11223 1 ‘$_any_caller_matches(REGEXP[, NUMBER_OF_FRAMES])’ d11230 1 a11230 1 This function differs from ‘$_caller_matches’ in that this function d11232 1 a11232 1 specified by NUMBER_OF_FRAMES, whereas ‘$_caller_matches’ only d11235 1 a11235 1 ‘$_as_string(VALUE)’ d11237 1 a11237 1 removed from future versions of GDB. Use the ‘%V’ format specifier d11249 3 a11251 3 ‘$_cimag(VALUE)’ ‘$_creal(VALUE)’ Return the imaginary (‘$_cimag’) or real (‘$_creal’) part of the d11255 2 a11256 2 complex number, e.g., using ‘$_cimag’ on a ‘float complex’ will return an imaginary part of type ‘float’. d11261 1 a11261 1 ‘help function’ d11271 2 a11272 2 with names starting with ‘$’. The names of registers are different for each machine; use ‘info registers’ to see the names used on your d11275 1 a11275 1 ‘info registers’ d11279 1 a11279 1 ‘info all-registers’ d11283 1 a11283 1 ‘info registers REGGROUP ...’ d11285 2 a11286 2 REGGROUPs. The REGGROUP can be any of those returned by ‘maint print reggroups’ (*note Maintenance Commands::). d11288 2 a11289 2 ‘info registers REGNAME ...’ Print the “relativized” value of each specified register REGNAME. d11293 1 a11293 1 ‘$’. d11298 3 a11300 3 ‘$pc’ and ‘$sp’ are used for the program counter register and the stack pointer. ‘$fp’ is used for a register that contains a pointer to the current stack frame, and ‘$ps’ is used for a register that contains the d11316 4 a11319 4 mnemonics, so long as there is no conflict. The ‘info registers’ command shows the canonical names. For example, on the SPARC, ‘info registers’ displays the processor status register as ‘$psr’ but you can also refer to it as ‘$ps’; and on x86-based machines ‘$ps’ is an alias d11327 2 a11328 2 (although you can _print_ it as a floating point value with ‘print/f $REGNAME’). d11337 1 a11337 1 sense for your program), but the ‘info registers’ command prints the d11344 1 a11344 1 ‘struct’ notation: d11359 1 a11359 1 ‘struct’ member: d11368 1 a11368 1 (with ‘frame 0’). d11380 1 a11380 1 GDB displays ‘’ as the register's value. With targets that d11397 1 a11397 1 assumes that the innermost stack frame is selected; setting ‘$sp’ is not d11399 1 a11399 1 the stack, regardless of machine architecture, use ‘return’; see *note d11411 1 a11411 1 ‘info float’ d11414 1 a11414 1 point chip. Currently, ‘info float’ is supported on the ARM and d11426 1 a11426 1 ‘info vector’ d11439 1 a11439 1 Some operating systems supply an “auxiliary vector” to programs at d11447 1 a11447 1 further depend on the remote stub's support of the ‘qXfer:auxv:read’ d11450 1 a11450 1 ‘info auxv’ d11464 1 a11464 1 remote stub's support of the ‘qXfer:osdata:read’ packet, see *note qXfer d11467 1 a11467 1 ‘info os INFOTYPE’ d11473 1 a11473 1 ‘cpus’ d11481 1 a11481 1 ‘files’ d11487 1 a11487 1 ‘modules’ d11494 1 a11494 1 ‘msg’ d11505 1 a11505 1 ‘processes’ d11514 1 a11514 1 ‘procgroups’ d11524 1 a11524 1 ‘semaphores’ d11532 1 a11532 1 ‘shm’ d11542 1 a11542 1 ‘sockets’ d11549 1 a11549 1 ‘threads’ d11556 1 a11556 1 ‘info os’ d11568 1 a11568 1 “Memory region attributes” allow you to describe special handling d11584 1 a11584 1 ‘mem LOWER UPPER ATTRIBUTES...’ d11591 1 a11591 1 ‘mem auto’ d11596 1 a11596 1 ‘delete mem NUMS...’ d11600 1 a11600 1 ‘disable mem NUMS...’ d11604 1 a11604 1 ‘enable mem NUMS...’ d11607 1 a11607 1 ‘info mem’ d11613 2 a11614 2 Enabled memory regions are marked with ‘y’. Disabled memory regions are marked with ‘n’. d11640 1 a11640 1 ‘ro’ d11642 1 a11642 1 ‘wo’ d11644 1 a11644 1 ‘rw’ d11655 1 a11655 1 ‘8’ d11657 1 a11657 1 ‘16’ d11659 1 a11659 1 ‘32’ d11661 1 a11661 1 ‘64’ d11672 1 a11672 1 ‘cache’ d11674 1 a11674 1 ‘nocache’ d11685 2 a11686 2 ‘set mem inaccessible-by-default [on|off]’ If ‘on’ is specified, make GDB treat memory not explicitly d11689 1 a11689 1 one memory range defined. If ‘off’ is specified, make GDB treat d11691 2 a11692 2 The default value is ‘on’. ‘show mem inaccessible-by-default’ d11701 3 a11703 3 You can use the commands ‘dump’, ‘append’, and ‘restore’ to copy data between target memory and a file. The ‘dump’ and ‘append’ commands write data to a file, and the ‘restore’ command reads data from a file d11708 2 a11709 2 ‘dump [FORMAT] memory FILENAME START_ADDR END_ADDR’ ‘dump [FORMAT] value FILENAME EXPR’ d11714 1 a11714 1 ‘binary’ d11716 1 a11716 1 ‘ihex’ d11718 1 a11718 1 ‘srec’ d11720 1 a11720 1 ‘tekhex’ d11722 1 a11722 1 ‘verilog’ d11726 1 a11726 1 utilities, like ‘objdump’ and ‘objcopy’. If FORMAT is omitted, GDB d11729 2 a11730 2 ‘append [binary] memory FILENAME START_ADDR END_ADDR’ ‘append [binary] value FILENAME EXPR’ d11735 2 a11736 2 ‘restore FILENAME [binary] BIAS START END’ Restore the contents of file FILENAME into memory. The ‘restore’ d11739 1 a11739 1 specify the optional keyword ‘binary’ after the filename. d11758 1 a11758 1 A “core file” or “core dump” is a file that records the memory image of d11769 2 a11770 2 ‘generate-core-file [FILE]’ ‘gcore [FILE]’ d11773 1 a11773 1 specified, the file name defaults to ‘core.PID’, where PID is the d11783 1 a11783 1 file ‘/proc/PID/coredump_filter’ when generating the core dump d11785 2 a11786 2 ‘VM_DONTDUMP’ flag for mappings where it is present in the file ‘/proc/PID/smaps’ (*note set dump-excluded-mappings::). d11788 3 a11790 3 ‘set use-coredump-filter on’ ‘set use-coredump-filter off’ Enable or disable the use of the file ‘/proc/PID/coredump_filter’ d11797 1 a11797 1 ‘/proc/PID/coredump_filter’ file a value, in hexadecimal, which is d11803 2 a11804 2 ‘/proc/PID/coredump_filter’ file, please refer to the manpage of ‘core(5)’. d11806 2 a11807 2 By default, this option is ‘on’. If this option is turned ‘off’, GDB does not read the ‘coredump_filter’ file and instead uses the d11810 3 a11812 3 currently ‘0x33’, which means that bits ‘0’ (anonymous private mappings), ‘1’ (anonymous shared mappings), ‘4’ (ELF headers) and ‘5’ (private huge pages) are active. This will cause these memory d11815 5 a11819 5 ‘set dump-excluded-mappings on’ ‘set dump-excluded-mappings off’ If ‘on’ is specified, GDB will dump memory mappings marked with the ‘VM_DONTDUMP’ flag. This flag is represented in the file ‘/proc/PID/smaps’ with the acronym ‘dd’. d11821 1 a11821 1 The default value is ‘off’. d11832 2 a11833 2 character set GDB uses we call the “host character set”; the one the inferior program uses we call the “target character set”. d11840 1 a11840 1 the command ‘set target-charset EBCDIC-US’, then GDB translates between d11845 1 a11845 1 inferior program uses; you must tell it, using the ‘set target-charset’ d11850 1 a11850 1 ‘set target-charset CHARSET’ d11853 1 a11853 1 ‘set target-charset ’. d11855 1 a11855 1 ‘set host-charset CHARSET’ d11859 2 a11860 2 it is running on; you can override that default using the ‘set host-charset’ command. On some systems, GDB cannot automatically d11862 1 a11862 1 uses ‘UTF-8’. d11865 1 a11865 1 If you type ‘set host-charset ’, GDB will list the host d11868 1 a11868 1 ‘set charset CHARSET’ d11870 1 a11870 1 above, if you type ‘set charset ’, GDB will list the d11874 1 a11874 1 ‘show charset’ d11877 1 a11877 1 ‘show host-charset’ d11880 1 a11880 1 ‘show target-charset’ d11883 1 a11883 1 ‘set target-wide-charset CHARSET’ d11885 1 a11885 1 the character set used by the target's ‘wchar_t’ type. To display d11887 1 a11887 1 ‘set target-wide-charset ’. d11889 1 a11889 1 ‘show target-wide-charset’ d11894 1 a11894 1 ‘charset-test.c’: d11910 2 a11911 2 In this program, ‘ascii_hello’ and ‘ibm1047_hello’ are arrays containing the string ‘Hello, world!’ followed by a newline, encoded in d11923 1 a11923 1 We can use the ‘show charset’ command to see what character sets GDB d11941 1 a11941 1 contents of ‘ascii_hello’ print legibly: d11956 1 a11956 1 The ASCII character set uses the number 43 to encode the ‘+’ d11960 1 a11960 1 program uses. If we print ‘ibm1047_hello’ while our target character d11969 1 a11969 1 If we invoke the ‘set target-charset’ followed by , GDB d11978 1 a11978 1 translates the contents of ‘ibm1047_hello’ from the target character d12003 1 a12003 1 The IBM1047 character set uses the number 78 to encode the ‘+’ d12026 2 a12027 2 ‘set remotecache on’ ‘set remotecache off’ d12031 1 a12031 1 ‘show remotecache’ d12034 4 a12037 4 ‘set stack-cache on’ ‘set stack-cache off’ Enable or disable caching of stack accesses. When ‘on’, use caching. By default, this option is ‘on’. d12039 1 a12039 1 ‘show stack-cache’ d12042 4 a12045 4 ‘set code-cache on’ ‘set code-cache off’ Enable or disable caching of code segment accesses. When ‘on’, use caching. By default, this option is ‘on’. This improves d12048 1 a12048 1 ‘show code-cache’ d12052 1 a12052 1 ‘info dcache [line]’ d12062 1 a12062 1 ‘set dcache size SIZE’ d12065 1 a12065 1 ‘set dcache line-size LINE-SIZE’ d12069 1 a12069 1 ‘show dcache size’ d12073 1 a12073 1 ‘show dcache line-size’ d12076 1 a12076 1 ‘maint flush dcache’ d12094 1 a12094 1 ‘find’ command. d12096 2 a12097 2 ‘find [/SN] START_ADDR, +LEN, VAL1 [, VAL2, ...]’ ‘find [/SN] START_ADDR, END_ADDR, VAL1 [, VAL2, ...]’ d12108 1 a12108 1 ‘b’ d12110 1 a12110 1 ‘h’ d12112 1 a12112 1 ‘w’ d12114 1 a12114 1 ‘g’ d12121 1 a12121 1 ‘{char[5]}"hello"’. d12127 1 a12127 1 for an untyped 0x42 will search for ‘(int) 0x42’ which is typically d12135 1 a12135 1 (‘"’). The string value is copied into the search pattern byte by byte, d12142 1 a12142 1 ‘$_’. A count of the number of matches is stored in ‘$numfound’. d12144 1 a12144 1 For example, if stopped at the ‘printf’ in this function: d12192 2 a12193 2 ‘set max-value-size BYTES’ ‘set max-value-size unlimited’ d12201 1 a12201 1 There's a minimum size that ‘max-value-size’ can be set to in order d12207 1 a12207 1 simple integer component, such as ‘x.y.z’, may fail if the size of d12209 1 a12209 1 sometimes clever; the expression ‘A[i]’, where A is an array d12214 1 a12214 1 The default value of ‘max-value-size’ is currently 64k. d12216 1 a12216 1 ‘show max-value-size’ d12239 1 a12239 1 When you debug a program compiled with ‘-g -O’, remember that the d12246 1 a12246 1 Some things do not work as well with ‘-g -O’ as with just ‘-g’, d12248 1 a12248 1 recompile with ‘-g’ alone, and if this fixes the problem, please report d12263 1 a12263 1 “Inlining” is an optimization that inserts a copy of the function body d12267 3 a12269 3 into them with ‘step’, skip them with ‘next’, and escape from them with ‘finish’. You can check whether a function was inlined by using the ‘info frame’ command. d12275 2 a12276 2 4.1 do not emit two required attributes (‘DW_AT_call_file’ and ‘DW_AT_call_line’); GDB does not display inlined function calls with d12289 1 a12289 1 single instruction using ‘stepi’ or ‘nexti’ does not do this; single d12295 1 a12295 1 • Setting breakpoints at the call site of an inlined function may not d12302 3 a12304 3 • GDB cannot locate the return value of inlined calls after using the ‘finish’ command. This is a limitation of compiler-generated debugging information; after ‘finish’, you can step to the next d12314 13 a12326 13 Function ‘B’ can call function ‘C’ in its very last statement. In unoptimized compilation the call of ‘C’ is immediately followed by return instruction at the end of ‘B’ code. Optimizing compiler may replace the call and return in function ‘B’ into one jump to function ‘C’ instead. Such use of a jump instruction is called “tail call”. During execution of function ‘C’, there will be no indication in the function call stack frames that it was tail-called from ‘B’. If function ‘A’ regularly calls function ‘B’ which tail-calls function ‘C’, then GDB will see ‘A’ as the caller of ‘C’. However, in some cases GDB can determine that ‘C’ was tail-called from ‘B’, and it will then create fictitious call frame for that, with the return address set up as if ‘B’ called ‘C’ normally. d12329 2 a12330 2 format and the compiler has to produce ‘DW_TAG_call_site’ tags. With GCC, you need to specify ‘-O -g’ during compilation, to get this d12333 2 a12334 2 ‘info frame’ command (*note Frame Info::) will indicate the tail call frame kind by text ‘tail call frame’ such as in this sample GDB output: d12354 1 a12354 1 ‘set debug entry-values’ d12362 1 a12362 1 ‘show debug entry-values’ d12367 2 a12368 2 virtual tail call frame for function ‘c’ has not been recognized (due to the indirect reference by variable ‘x’): d12406 2 a12407 2 can have possible execution paths ‘main→a→b→c→d→f’ or ‘main→a→b→e→f’, GDB cannot find which one from the inferior state. d12409 1 a12409 1 ‘initial:’ state shows some random possible calling sequence GDB has d12411 3 a12413 3 prefixed by ‘compare:’. The non-ambiguous intersection of these two is printed as the ‘reduced:’ calling sequence. That one could have many further ‘compare:’ and ‘reduced:’ statements as long as there remain any d12416 2 a12417 2 For the frame of function ‘b’ in both cases there are different possible ‘$pc’ values (‘0x4004cc’ or ‘0x4004ce’), therefore this frame d12419 1 a12419 1 ‘a’, therefore this one is displayed to the user while the ambiguous d12441 2 a12442 2 function ‘a’ call itself (via function ‘b’) as these calls would be tail calls. Such tail calls would modify the ‘i’ variable, therefore GDB d12444 1 a12444 1 ‘’ instead. d12461 1 a12461 1 ‘-g’ flag. *Note Compilation::. d12475 2 a12476 2 ‘macro expand EXPRESSION’ ‘macro exp EXPRESSION’ d12482 2 a12483 2 ‘macro expand-once EXPRESSION’ ‘macro exp1 EXPRESSION’ d12493 1 a12493 1 ‘info macro [-a|-all] [--] MACRO’ d12500 1 a12500 1 ‘info macros LOCSPEC’ d12506 2 a12507 2 ‘macro define MACRO REPLACEMENT-LIST’ ‘macro define MACRO(ARGLIST) REPLACEMENT-LIST’ d12516 2 a12517 2 expression evaluated in GDB, until it is removed with the ‘macro undef’ command, described below. The definition overrides all d12521 1 a12521 1 ‘macro undef MACRO’ d12523 2 a12524 2 This command only affects definitions provided with the ‘macro define’ command, described above; it cannot remove definitions d12527 2 a12528 2 ‘macro list’ List all the macros defined using the ‘macro define’ command. d12554 1 a12554 1 the ‘-gdwarf-2’(1) _and_ ‘-g3’ flags to ensure the compiler includes d12596 1 a12596 1 In the example above, note that ‘macro expand-once’ expands only the d12598 2 a12599 2 ‘ADD’ -- but does not expand the invocation of the macro ‘M’, which was introduced by ‘ADD’. d12613 1 a12613 1 At line 10, the definition of the macro ‘N’ at line 9 is in force: d12624 1 a12624 1 As we step over directives that remove ‘N’'s definition, and then d12647 1 a12647 1 command line using the ‘-DNAME=VALUE’ syntax. For macros defined in d12658 2 a12659 2 (1) This is the minimum. Recent versions of GCC support ‘-gdwarf-3’ and ‘-gdwarf-4’; we recommend always choosing the most recent version of d12676 3 a12678 3 Using GDB's ‘trace’ and ‘collect’ commands, you can specify locations in the program, called “tracepoints”, and arbitrary expressions to evaluate when those tracepoints are reached. Later, using the ‘tfind’ d12695 1 a12695 1 reminiscent of corefiles; you specify the filename, and use ‘tfind’ to d12713 1 a12713 1 Before running such a “trace experiment”, an arbitrary number of d12731 1 a12731 1 Some targets may support “fast tracepoints”, which are inserted in a d12737 3 a12739 3 the target. Some targets may also support controlling “static tracepoints” from GDB. With static tracing, a set of instrumentation points, also known as “markers”, are embedded in the target program, and d12749 1 a12749 1 referred to as “probing” a static tracepoint marker. d12751 2 a12752 2 ‘gdbserver’ supports tracepoints on some target systems. *Note Tracepoints support in ‘gdbserver’: Server. d12776 2 a12777 2 ‘trace LOCSPEC’ The ‘trace’ command is very similar to the ‘break’ command. Its d12779 1 a12779 1 Location Specifications::. The ‘trace’ command defines a d12784 3 a12786 3 ‘InstallInTrace’ feature (*note install tracepoint in tracing::). If remote stub doesn't support the ‘InstallInTrace’ feature, all these changes don't take effect until the next ‘tstart’ command, d12789 1 a12789 1 addition, GDB supports “pending tracepoints”--tracepoints whose d12798 1 a12798 1 Here are some examples of using the ‘trace’ command: d12810 1 a12810 1 You can abbreviate ‘trace’ as ‘tr’. d12812 1 a12812 1 ‘trace LOCSPEC if COND’ d12819 2 a12820 2 ‘ftrace LOCSPEC [ if COND ]’ The ‘ftrace’ command sets a fast tracepoint. For targets that d12828 1 a12828 1 GDB handles arguments to ‘ftrace’ exactly as for ‘trace’. d12836 2 a12837 2 is possible to let GDB use this area by doing a ‘sysctl’ command to set the ‘mmap_min_addr’ kernel parameter, as in d12844 2 a12845 2 ‘strace [LOCSPEC | -m MARKER] [ if COND ]’ The ‘strace’ command sets a static tracepoint. For targets that d12852 2 a12853 2 GDB handles arguments to ‘strace’ exactly as for ‘trace’, with the addition that the user can also specify ‘-m MARKER’ instead of a d12857 2 a12858 2 the marker identifiers in the ‘ID’ field of the ‘info static-tracepoint-markers’ command output. *Note Listing Static d12869 1 a12869 1 ‘trace_mark’ call with a slash, which translates to: d12881 2 a12882 2 Static tracepoints accept an extra collect action -- ‘collect $_sdata’. This collects arbitrary user data passed in the probe d12884 1 a12884 1 you'll see that the third argument to ‘trace_mark’ is a printf-like d12886 3 a12888 3 formatting string against the following arguments. Note that ‘info static-tracepoint-markers’ command output lists that format string in the ‘Data:’ field. d12894 1 a12894 1 The convenience variable ‘$tpnum’ records the tracepoint number of d12897 1 a12897 1 ‘delete tracepoint [NUM]’ d12900 1 a12900 1 ‘delete’ command can remove tracepoints also. d12908 1 a12908 1 You can abbreviate this command as ‘del tr’. d12916 2 a12917 2 These commands are deprecated; they are equivalent to plain ‘disable’ and ‘enable’. d12919 1 a12919 1 ‘disable tracepoint [NUM]’ d12923 1 a12923 1 tracepoint using the ‘enable tracepoint’ command. If the command d12929 1 a12929 1 ‘enable tracepoint [NUM]’ d12942 2 a12943 2 ‘passcount [N [NUM]]’ Set the “passcount” of a tracepoint. The passcount is a way to d12947 1 a12947 1 is not specified, the ‘passcount’ command sets the passcount of the d12975 1 a12975 1 reaches a specified place. You can also specify a “condition” for a d12982 1 a12982 1 using ‘if’ in the arguments to the ‘trace’ command. *Note Setting d12984 1 a12984 1 changed at any time with the ‘condition’ command, just as with d13008 1 a13008 1 A “trace state variable” is a special type of variable that is created d13012 1 a13012 1 ‘tvariable’ command. They are always 64-bit signed integers. d13024 1 a13024 1 state variables with names like ‘$23’ or ‘$pc’, nor can you have a trace d13027 3 a13029 3 ‘tvariable $NAME [ = EXPRESSION ]’ The ‘tvariable’ command creates a new trace state variable named ‘$NAME’, and optionally gives it an initial value of EXPRESSION. d13032 1 a13032 1 will report an error. A subsequent ‘tvariable’ command specifying d13038 1 a13038 1 ‘info tvariables’ d13043 1 a13043 1 ‘delete tvariable [ $NAME ... ]’ d13053 1 a13053 1 ‘actions [NUM]’ d13057 1 a13057 1 defined (so that you can define a tracepoint and then say ‘actions’ d13060 3 a13062 3 terminate the actions list with a line containing just ‘end’. So far, the only defined actions are ‘collect’, ‘teval’, and ‘while-stepping’. d13064 1 a13064 1 ‘actions’ is actually equivalent to ‘commands’ (*note Breakpoint d13068 2 a13069 2 To remove all actions from a tracepoint, type ‘actions NUM’ and follow it immediately with ‘end’. d13077 1 a13077 1 In the following example, the action list begins with ‘collect’ d13080 1 a13080 1 following the tracepoint, a ‘while-stepping’ command is used, d13082 3 a13084 3 sequence of single steps. The ‘while-stepping’ command is terminated by its own separate ‘end’ command. Lastly, the action list is terminated by an ‘end’ command. d13096 1 a13096 1 ‘collect[/MODS] EXPR1, EXPR2, ...’ d13102 1 a13102 1 ‘$regs’ d13105 1 a13105 1 ‘$args’ d13108 1 a13108 1 ‘$locals’ d13111 1 a13111 1 ‘$_ret’ d13123 1 a13123 1 ‘$_probe_argc’ d13127 1 a13127 1 ‘$_probe_argN’ d13132 1 a13132 1 ‘$_sdata’ d13136 1 a13136 1 library backend, an instrumentation point resembles a ‘printf’ d13146 3 a13148 3 In this case, collecting ‘$_sdata’ collects the string ‘hello $yourname’. When analyzing the trace buffer, you can inspect ‘$_sdata’ like any other variable available to GDB. d13150 2 a13151 2 You can give several consecutive ‘collect’ commands, each one with a single argument, or one ‘collect’ command with several arguments d13154 1 a13154 1 The optional MODS changes the usual handling of the arguments. ‘s’ d13158 1 a13158 1 the ‘print characters’ variable; if ‘s’ is followed by a decimal d13160 1 a13160 1 ‘collect/s25 mystr’ collects as many as 25 characters at ‘mystr’. d13162 1 a13162 1 The command ‘info scope’ (*note info scope: Symbols.) is d13165 1 a13165 1 ‘teval EXPR1, EXPR2, ...’ d13171 1 a13171 1 the ‘collect’ action were used. d13173 1 a13173 1 ‘while-stepping N’ d13175 1 a13175 1 collecting new data after each step. The ‘while-stepping’ command d13177 1 a13177 1 by its own ‘end’ command): d13184 1 a13184 1 Note that ‘$pc’ is not automatically collected by ‘while-stepping’; d13186 1 a13186 1 may abbreviate ‘while-stepping’ as ‘ws’ or ‘stepping’. d13188 1 a13188 1 ‘set default-collect EXPR1, EXPR2, ...’ d13190 1 a13190 1 tracepoint hit. It is effectively an additional ‘collect’ action d13193 1 a13193 1 named ‘xyz’ may be interpreted as a global for one tracepoint, and d13196 1 a13196 1 ‘show default-collect’ d13206 1 a13206 1 ‘info tracepoints [NUM...]’ d13209 2 a13210 2 defined so far. The format is similar to that used for ‘info breakpoints’; in fact, ‘info tracepoints’ is the same command, d13216 1 a13216 1 • its passcount as given by the ‘passcount N’ command d13218 1 a13218 1 • the state about installed on target of each location d13240 1 a13240 1 This command can be abbreviated ‘info tp’. d13248 1 a13248 1 ‘info static-tracepoint-markers’ d13260 1 a13260 1 Probed markers are tagged with ‘y’. ‘n’ identifies marks that d13295 1 a13295 1 ‘tstart’ d13305 1 a13305 1 ‘tstop’ d13316 1 a13316 1 ‘tstatus’ d13336 1 a13336 1 such as ‘detach’, the debugger will ask what you want to do with the d13339 1 a13339 1 ‘disconnected-tracing’ lets you decide whether the trace should continue d13342 2 a13343 2 ‘set disconnected-tracing on’ ‘set disconnected-tracing off’ d13345 1 a13345 1 disconnected from the target. Note that ‘detach’ or ‘quit’ will d13350 1 a13350 1 ‘show disconnected-tracing’ d13369 1 a13369 1 If your target agent supports a “circular trace buffer”, then you can d13375 1 a13375 1 ask for a circular trace buffer, simply set ‘circular-trace-buffer’ to d13380 2 a13381 2 ‘set circular-trace-buffer on’ ‘set circular-trace-buffer off’ d13388 1 a13388 1 ‘show circular-trace-buffer’ d13394 2 a13395 2 ‘set trace-buffer-size N’ ‘set trace-buffer-size unlimited’ d13399 1 a13399 1 ‘unlimited’ or ‘-1’ to let the target use whatever size it likes. d13402 1 a13402 1 ‘show trace-buffer-size’ d13408 1 a13408 1 starts. Use ‘tstatus’ to get a report of the actual buffer size. d13410 1 a13410 1 ‘set trace-user TEXT’ d13412 1 a13412 1 ‘show trace-user’ d13414 1 a13414 1 ‘set trace-notes TEXT’ d13417 1 a13417 1 ‘show trace-notes’ d13420 1 a13420 1 ‘set trace-stop-notes TEXT’ d13422 1 a13422 1 ‘tstop’ arguments; the set command is convenient way to fix a stop d13425 1 a13425 1 ‘show trace-stop-notes’ d13442 1 a13442 1 • Tracepoint expressions are intended to gather objects (lvalues). d13450 2 a13451 2 • Collection of local variables, either individually or in bulk with ‘$locals’ or ‘$args’, during ‘while-stepping’ may behave d13458 1 a13458 1 where the steps of a ‘while-stepping’ sequence will advance the d13461 1 a13461 1 • Collection of an incompletely-initialized or partially-destroyed d13465 1 a13465 1 • When GDB displays a pointer to character it automatically d13471 2 a13472 2 example, ‘*ptr@@50’ can be used to collect the 50 element array pointed to by ‘ptr’. d13474 1 a13474 1 • It is not possible to collect a complete stack backtrace at a d13477 1 a13477 1 ‘*(unsigned char *)$esp@@300’ (adjust to use the name of the actual d13479 1 a13479 1 of stack you wish to capture). Then the ‘backtrace’ command will d13486 2 a13487 2 • If you do not collect registers at a tracepoint, GDB can infer that the value of ‘$pc’ must be the same as the address of the d13491 2 a13492 2 was inlined), or if it has a ‘while-stepping’ loop. In those cases GDB will warn you that it can't infer ‘$pc’, and default it to d13503 1 a13503 1 “snapshot” every time it is hit and another snapshot every time it d13506 1 a13506 1 examine them is to “focus” on a specific trace snapshot. When the d13511 1 a13511 1 (‘print’, ‘info registers’, ‘backtrace’, etc.) will behave as if we d13524 1 a13524 1 13.2.1 ‘tfind N’ d13528 1 a13528 1 ‘tfind N’, which finds trace snapshot number N, counting from zero. If d13531 1 a13531 1 Here are the various forms of using the ‘tfind’ command. d13533 1 a13533 1 ‘tfind start’ d13535 1 a13535 1 ‘tfind 0’ (since 0 is the number of the first snapshot). d13537 1 a13537 1 ‘tfind none’ d13540 2 a13541 2 ‘tfind end’ Same as ‘tfind none’. d13543 1 a13543 1 ‘tfind’ d13547 1 a13547 1 ‘tfind -’ d13551 1 a13551 1 ‘tfind tracepoint NUM’ d13557 1 a13557 1 ‘tfind pc ADDR’ d13563 1 a13563 1 ‘tfind outside ADDR1, ADDR2’ d13567 1 a13567 1 ‘tfind range ADDR1, ADDR2’ d13571 1 a13571 1 ‘tfind line [FILE:]N’ d13576 2 a13577 2 other than the one currently being examined; thus saying ‘tfind line’ repeatedly can appear to have the same effect as stepping d13580 1 a13580 1 The default arguments for the ‘tfind’ commands are specifically d13582 4 a13585 4 instance, ‘tfind’ with no argument selects the next trace snapshot, and ‘tfind -’ with no argument selects the previous trace snapshot. So, by giving one ‘tfind’ command, and then simply hitting repeatedly you can examine all the trace snapshots in order. Or, by saying ‘tfind -’ d13587 2 a13588 2 reverse order. The ‘tfind line’ command with no argument selects the snapshot for the next source line executed. The ‘tfind pc’ command with d13590 1 a13590 1 as the current frame. The ‘tfind tracepoint’ command with no argument d13619 1 a13619 1 Or, if we want to examine the variable ‘X’ at each source line in the d13635 1 a13635 1 13.2.2 ‘tdump’ d13688 2 a13689 2 ‘tdump’ works by scanning the tracepoint's current collection actions and printing the value of each expression listed. So ‘tdump’ can fail, d13693 2 a13694 2 Also, for tracepoints with ‘while-stepping’ loops, ‘tdump’ uses the collected value of ‘$pc’ to distinguish between trace frames that were d13698 1 a13698 1 while-stepping loop. However, if ‘$pc’ was not collected, then ‘tdump’ d13706 1 a13706 1 13.2.3 ‘save tracepoints FILENAME’ d13710 1 a13710 1 their actions and passcounts, into a file ‘FILENAME’ suitable for use in d13712 2 a13713 2 use the ‘source’ command (*note Command Files::). The ‘save-tracepoints’ command is a deprecated alias for ‘save tracepoints’ d13721 2 a13722 2 ‘(int) $trace_frame’ The current trace snapshot (a.k.a. “frame”) number, or -1 if no d13725 1 a13725 1 ‘(int) $tracepoint’ d13728 1 a13728 1 ‘(int) $trace_line’ d13731 1 a13731 1 ‘(char []) $trace_file’ d13734 2 a13735 2 ‘(char []) $trace_func’ The name of the function containing ‘$tracepoint’. d13737 1 a13737 1 Note: ‘$trace_file’ is not suitable for use in ‘printf’, use ‘output’ d13763 1 a13763 1 data, via the ‘target tfile’ command. d13765 2 a13766 2 ‘tsave [ -r ] FILENAME’ ‘tsave [-ctf] DIRNAME’ d13771 1 a13771 1 ‘-r’ ("remote") to direct the target to save the data directly into d13773 1 a13773 1 trace buffer is very large. (Note, however, that ‘target tfile’ d13776 2 a13777 2 optional argument ‘-ctf’ to save data in CTF format. The “Common Trace Format” (CTF) is proposed as a trace format that can be d13779 1 a13779 1 ‘http://www.efficios.com/ctf’ to get more information. d13781 2 a13782 2 ‘target tfile FILENAME’ ‘target ctf DIRNAME’ d13786 1 a13786 1 experiments. ‘tstatus’ will report the state of the trace run at d13812 1 a13812 1 memory, you can sometimes use “overlays” to work around this problem. d13837 1 a13837 1 these modules “overlays”. Separate the overlays from the main program, d13883 1 a13883 1 a “mapped” overlay; its “mapped address” is its address in the d13885 1 a13885 1 in instruction memory is called “unmapped”; its “load address” is its d13887 2 a13888 2 “virtual memory address”, or “VMA”; the load address is also called the “load memory address”, or “LMA”. d13894 1 a13894 1 • Before calling or returning to a function in an overlay, your d13899 1 a13899 1 • If the process of mapping an overlay is expensive on your system, d13903 1 a13903 1 • The executable file you load onto your system must contain each d13911 1 a13911 1 • The procedure for loading executable files onto your system must be d13918 1 a13918 1 • If your system has suitable bank switch registers or memory d13924 1 a13924 1 • If your overlays are small enough, you could set aside more than d13927 1 a13927 1 • You can use overlays to manage data, as well as instructions. In d13949 2 a13950 2 GDB's overlay commands all start with the word ‘overlay’; you can abbreviate this as ‘ov’ or ‘ovly’. The commands are: d13952 1 a13952 1 ‘overlay off’ d13958 2 a13959 2 ‘overlay manual’ Enable “manual” overlay debugging. In this mode, GDB relies on you d13961 1 a13961 1 ‘overlay map-overlay’ and ‘overlay unmap-overlay’ commands d13964 2 a13965 2 ‘overlay map-overlay OVERLAY’ ‘overlay map OVERLAY’ d13973 2 a13974 2 ‘overlay unmap-overlay OVERLAY’ ‘overlay unmap OVERLAY’ d13980 2 a13981 2 ‘overlay auto’ Enable “automatic” overlay debugging. In this mode, GDB consults a d13986 2 a13987 2 ‘overlay load-target’ ‘overlay load’ d13994 2 a13995 2 ‘overlay list-overlays’ ‘overlay list’ d14006 1 a14006 1 around them. For example, if ‘foo’ is a function in an unmapped d14013 1 a14013 1 When ‘foo’'s overlay is mapped, GDB prints the function's name normally: d14023 1 a14023 1 mapped. This allows most GDB commands, like ‘break’ and ‘disassemble’, d14027 1 a14027 1 • You can set breakpoints in functions in unmapped overlays, as long d14029 1 a14029 1 • GDB can not set hardware or simulator-based breakpoints in unmapped d14043 1 a14043 1 If you enable automatic overlay debugging with the ‘overlay auto’ d14050 1 a14050 1 ‘_ovly_table’: d14069 1 a14069 1 ‘_novlys’: d14071 1 a14071 1 number of elements in ‘_ovly_table’. d14074 1 a14074 1 for an entry in ‘_ovly_table’ whose ‘vma’ and ‘lma’ members equal the d14076 1 a14076 1 finds a matching entry, it consults the entry's ‘mapped’ member to d14080 1 a14080 1 ‘_ovly_debug_event’. If this function is defined, GDB will silently set d14105 1 a14105 1 ‘gdb/testsuite/gdb.base’: d14107 1 a14107 1 ‘overlays.c’ d14109 11 a14119 11 ‘ovlymgr.c’ A simple overlay manager, used by ‘overlays.c’. ‘foo.c’ ‘bar.c’ ‘baz.c’ ‘grbx.c’ Overlay modules, loaded and used by ‘overlays.c’. ‘d10v.ld’ ‘m32r.ld’ Linker scripts for linking the test program on the ‘d10v-elf’ and ‘m32r-elf’ targets. d14121 1 a14121 1 You can build the test program using the ‘d10v-elf’ GCC d14135 1 a14135 1 the target system for ‘d10v-elf-gcc’ and ‘d10v.ld’. d14145 4 a14148 4 dereferencing a pointer ‘p’ is accomplished by ‘*p’, but in Modula-2, it is accomplished by ‘p^’. Values can also be represented (and displayed) differently. Hex numbers in C appear as ‘0x1ae’, while in Modula-2 they appear as ‘1AEH’. d14154 1 a14154 1 language you use to build expressions is called the “working language”. d14171 2 a14172 2 it automatically, or select it manually yourself. You can use the ‘set language’ command for either purpose. On startup, GDB defaults to d14182 1 a14182 1 demangled--this way ‘backtrace’ can show each frame appropriately for d14188 2 a14189 2 ‘cfront’ or ‘f2c’, that generates C but is written in another language. In that case, make the program use ‘#line’ directives in its C output; d14209 4 a14212 4 ‘.ada’ ‘.ads’ ‘.adb’ ‘.a’ d14215 1 a14215 1 ‘.c’ d14218 6 a14223 6 ‘.C’ ‘.cc’ ‘.cp’ ‘.cpp’ ‘.cxx’ ‘.c++’ d14226 1 a14226 1 ‘.d’ d14229 1 a14229 1 ‘.m’ d14232 2 a14233 2 ‘.f’ ‘.F’ d14236 1 a14236 1 ‘.mod’ d14239 2 a14240 2 ‘.s’ ‘.S’ d14257 3 a14259 3 the command ‘set language LANG’, where LANG is the name of a language, such as ‘c’ or ‘modula-2’. For a list of the supported languages, type ‘set language’. d14270 4 a14273 4 might not have the effect you intended. In C, this means to add ‘b’ and ‘c’ and place the result in ‘a’. The result printed would be the value of ‘a’. In Modula-2, this means to compare ‘a’ to the result of ‘b+c’, yielding a ‘BOOLEAN’ value. d14281 2 a14282 2 To have GDB set the working language automatically, use ‘set language local’ or ‘set language auto’. GDB then infers the working language. d14293 1 a14293 1 a different source language. Using ‘set language auto’ in this case d14305 1 a14305 1 ‘show language’ d14307 1 a14307 1 use with commands such as ‘print’ to build and compute expressions d14310 1 a14310 1 ‘info frame’ d14316 1 a14316 1 ‘info source’ d14325 1 a14325 1 ‘set extension-language EXT LANGUAGE’ d14329 1 a14329 1 ‘info extensions’ d14349 1 a14349 1 evaluation via the ‘print’ command, for example. d14375 1 a14375 1 The second example fails because in C++ the integer constant ‘0x1234’ d14385 1 a14385 1 does not know how to add an ‘int’ and a ‘struct foo’. These particular d14391 2 a14392 2 ‘set check type on’ ‘set check type off’ d14397 1 a14397 1 ‘show check type’ d14425 1 a14425 1 M + 1 ⇒ S d14435 1 a14435 1 ‘set check range auto’ d14440 2 a14441 2 ‘set check range on’ ‘set check range off’ d14448 1 a14448 1 ‘set check range warn’ d14455 1 a14455 1 ‘show check range’ d14467 2 a14468 2 expressions regardless of the language you use: the GDB ‘@@’ and ‘::’ operators, and the ‘{type}addr’ construct (*note Expressions: d14505 1 a14505 1 GNU ‘g++’, or the HP ANSI C++ compiler (‘aCC’). d14525 1 a14525 1 ‘+’ is defined on numbers, but not on structures. Operators are often d14530 2 a14531 2 • _Integral types_ include ‘int’ with any of its storage-class specifiers; ‘char’; ‘enum’; and, for C++, ‘bool’. d14533 1 a14533 1 • _Floating-point types_ include ‘float’, ‘double’, and ‘long double’ d14536 1 a14536 1 • _Pointer types_ include all types defined as ‘(TYPE *)’. d14538 1 a14538 1 • _Scalar types_ include all of the above. d14543 1 a14543 1 ‘,’ d14548 1 a14548 1 ‘=’ d14552 5 a14556 5 ‘OP=’ Used in an expression of the form ‘A OP= B’, and translated to ‘A = A OP B’. ‘OP=’ and ‘=’ have the same precedence. The operator OP is any one of the operators ‘|’, ‘^’, ‘&’, ‘<<’, ‘>>’, ‘+’, ‘-’, ‘*’, ‘/’, ‘%’. d14558 2 a14559 2 ‘?:’ The ternary operator. ‘A ? B : C’ can be thought of as: if A then d14562 1 a14562 1 ‘||’ d14565 1 a14565 1 ‘&&’ d14568 1 a14568 1 ‘|’ d14571 1 a14571 1 ‘^’ d14574 1 a14574 1 ‘&’ d14577 1 a14577 1 ‘==, !=’ d14581 1 a14581 1 ‘<, >, <=, >=’ d14586 1 a14586 1 ‘<<, >>’ d14589 1 a14589 1 ‘@@’ d14593 1 a14593 1 ‘+, -’ d14597 1 a14597 1 ‘*, /, %’ d14602 1 a14602 1 ‘++, --’ d14608 1 a14608 1 ‘*’ d14610 1 a14610 1 as ‘++’. d14612 2 a14613 2 ‘&’ Address operator. Defined on variables. Same precedence as ‘++’. d14615 2 a14616 2 For debugging C++, GDB implements a use of ‘&’ beyond what is allowed in the C++ language itself: you can use ‘&(&REF)’ to d14618 1 a14618 1 ‘&REF’) is stored. d14620 1 a14620 1 ‘-’ d14622 1 a14622 1 precedence as ‘++’. d14624 1 a14624 1 ‘!’ d14626 1 a14626 1 ‘++’. d14628 1 a14628 1 ‘~’ d14630 1 a14630 1 precedence as ‘++’. d14632 1 a14632 1 ‘., ->’ d14636 1 a14636 1 Defined on ‘struct’ and ‘union’ data. d14638 1 a14638 1 ‘.*, ->*’ d14641 10 a14650 10 ‘[]’ Array indexing. ‘A[I]’ is defined as ‘*(A+I)’. Same precedence as ‘->’. ‘()’ Function parameter list. Same precedence as ‘->’. ‘::’ C++ scope resolution operator. Defined on ‘struct’, ‘union’, and ‘class’ types. d14652 1 a14652 1 ‘::’ d14654 1 a14654 1 Expressions: Expressions.). Same precedence as ‘::’, above. d14669 4 a14672 4 • Integer constants are a sequence of digits. Octal constants are specified by a leading ‘0’ (i.e. zero), and hexadecimal constants by a leading ‘0x’ or ‘0X’. Constants may also end with a letter ‘l’, specifying that the constant should be treated as a ‘long’ d14675 1 a14675 1 • Floating point constants are a sequence of digits, followed by a d14678 1 a14678 1 ‘e[[+]|-]NNN’, where NNN is another sequence of digits. The ‘+’ is d14680 4 a14683 4 also end with a letter ‘f’ or ‘F’, specifying that the constant should be treated as being of the ‘float’ (as opposed to the default ‘double’) type; or with a letter ‘l’ or ‘L’, which specifies a ‘long double’ constant. d14685 1 a14685 1 • Enumerated constants consist of enumerated identifiers, or their d14688 2 a14689 2 • Character constants are a single character surrounded by single quotes (‘'’), or a number--the ordinal value of the corresponding d14691 4 a14694 4 character may be represented by a letter or by “escape sequences”, which are of the form ‘\NNN’, where NNN is the octal representation of the character's ordinal value; or of the form ‘\X’, where ‘X’ is a predefined special character--for example, ‘\n’ for newline. d14697 2 a14698 2 constant with ‘L’, as in C. For example, ‘L'x'’ is the wide form of ‘x’. The target wide character set is used when computing the d14701 2 a14702 2 • String constants are a sequence of character constants surrounded by double quotes (‘"’). Any valid character constant (as described d14704 1 a14704 1 preceded by a backslash, so for instance ‘"a\"b'c"’ is a string of d14708 1 a14708 1 with ‘L’, as in C. The target wide character set is used when d14711 2 a14712 2 • Pointer constants are an integral value. You can also write pointers to constants using the C operator ‘&’. d14714 4 a14717 4 • Array constants are comma-separated lists surrounded by braces ‘{’ and ‘}’; for example, ‘{1,2,3}’ is a three-element array of integers, ‘{{1,2}, {3,4}, {5,6}}’ is a three-by-two array, and ‘{&"hi", &"there", &"fred"}’ is a three-element array of pointers. d14742 1 a14742 1 instance pointer ‘this’ following the same rules as C++. ‘using’ d14759 1 a14759 1 ‘set overload-resolution off’. *Note GDB Features for C++: d14762 1 a14762 1 You must specify ‘set overload-resolution off’ in order to use an d14777 1 a14777 1 unless you have specified ‘set print address off’. d14779 1 a14779 1 5. GDB supports the C++ name resolution operator ‘::’--your d14781 1 a14781 1 Since one scope may be defined in another, you can use ‘::’ d14783 1 a14783 1 ‘SCOPE1::SCOPE2::NAME’. GDB also allows resolving name scope by d14797 1 a14797 1 ‘off’ whenever the working language changes to C or C++. This happens d14801 1 a14801 1 source files whose names end with ‘.c’, ‘.C’, or ‘.cc’, etc, and when d14827 3 a14829 3 The ‘set print union’ and ‘show print union’ commands apply to the ‘union’ type. When set to ‘on’, any ‘union’ that is inside a ‘struct’ or ‘class’ is also printed. Otherwise, it appears as ‘{...}’. d14831 1 a14831 1 The ‘@@’ operator aids in the debugging of dynamic arrays, formed with d14844 1 a14844 1 ‘breakpoint menus’ d14850 1 a14850 1 ‘rbreak REGEX’ d14855 3 a14857 3 ‘catch throw’ ‘catch rethrow’ ‘catch catch’ d14861 1 a14861 1 ‘ptype TYPENAME’ d14865 2 a14866 2 ‘info vtbl EXPRESSION.’ The ‘info vtbl’ command can be used to display the virtual method d14871 1 a14871 1 ‘demangle NAME’ d14873 1 a14873 1 the ‘demangle’ command. d14875 4 a14878 4 ‘set print demangle’ ‘show print demangle’ ‘set print asm-demangle’ ‘show print asm-demangle’ d14883 2 a14884 2 ‘set print object’ ‘show print object’ d14888 2 a14889 2 ‘set print vtbl’ ‘show print vtbl’ d14891 2 a14892 2 Print Settings: Print Settings. (The ‘vtbl’ commands do not work on programs compiled with the HP ANSI C++ compiler (‘aCC’).) d14894 1 a14894 1 ‘set overload-resolution on’ d14902 1 a14902 1 ‘set overload-resolution off’ d14911 1 a14911 1 ‘show overload-resolution’ d14914 1 a14914 1 ‘Overloaded symbol names’ d14917 1 a14917 1 C++: type ‘SYMBOL(TYPES)’ rather than just SYMBOL. You can also d14922 1 a14922 1 ‘Breakpoints in template functions’ d14930 1 a14930 1 The ‘-qualified’ flag may be used to override this behavior, d14938 1 a14938 1 ‘Breakpoints in functions with ABI tags’ d14951 1 a14951 1 when compiled for the C++11 ABI is marked with the ‘cxx11’ ABI tag, d14980 1 a14980 1 ‘_Decimal32’, ‘_Decimal64’ and ‘_Decimal128’ types as specified by the d14988 1 a14988 1 Because of a limitation in ‘libdecnumber’, the library used by GDB to d14997 1 a14997 1 to inspect ‘_Decimal128’ values stored in floating point registers. See d15017 1 a15017 1 ‘gccgo’ or ‘6g’ compilers. d15021 1 a15021 1 ‘The current Go package’ d15033 1 a15033 1 When stopped inside ‘main’ either of these work: d15038 2 a15039 2 ‘Builtin Go types’ The ‘string’ type is recognized by GDB and is printed as a string. d15041 2 a15042 2 ‘Builtin Go functions’ The GDB expression parser recognizes the ‘unsafe.Sizeof’ function d15045 2 a15046 2 ‘Restrictions on Go expressions’ All Go operators are supported except ‘&^’. The Go ‘_’ "blank d15075 5 a15079 5 • ‘clear’ • ‘break’ • ‘info line’ • ‘jump’ • ‘list’ d15089 2 a15090 2 example, to set a breakpoint at the ‘create’ instance method of class ‘Fruit’ in the program currently being debugged, enter: d15094 1 a15094 1 To list ten program lines around the ‘initialize’ class method, d15107 1 a15107 1 your program's source files contain more than one ‘create’ method, d15109 1 a15109 1 method. Indicate your choice by number, or type ‘0’ to exit if none d15113 1 a15113 1 ‘makeKeyAndOrderFront:’ method of the ‘NSWindow’ class, enter: d15128 2 a15129 2 will tell GDB to send the ‘hash’ message to OBJECT and print the result. Also, an additional command has been added, ‘print-object’ or ‘po’ for d15132 1 a15132 1 a particular hook function, ‘_NSPrintForDebugger’, defined. d15156 1 a15156 1 types of the ‘cl_khr_fp16’ and ‘cl_khr_fp64’ OpenCL extensions are also d15194 1 a15194 1 the ‘set case-insensitive’ command, see *note Symbols::, for the d15210 5 a15214 5 In Fortran the primitive data-types have an associated ‘KIND’ type parameter, written as ‘TYPE*KINDPARAM’, ‘TYPE*KINDPARAM’, or in the GDB-only dialect ‘TYPE_KINDPARAM’. A concrete example would be ‘‘Real*4’’, ‘‘Real(kind=4)’’, and ‘‘Real_4’’. The kind of a type can be retrieved by using the intrinsic function ‘KIND’, see *note Fortran d15217 1 a15217 1 Generally, the actual implementation of the ‘KIND’ type parameter is d15219 1 a15219 1 accordance with its use in the GNU ‘gfortran’ compiler. Here, the kind d15221 2 a15222 2 ‘Integer*4’ or ‘Integer(kind=4)’ would be an integer type occupying 4 bytes of memory. An exception to this rule is the ‘Complex’ type for d15224 2 a15225 2 size of each of the two ‘Real’'s it is composed of. A ‘Complex*4’ would thus consist of two ‘Real*4’s and occupy 8 bytes of memory. d15228 1 a15228 1 e.g. ‘Integer’ in GDB will internally be an ‘Integer*4’ (see the table d15231 1 a15231 1 by compiler flags such as ‘-fdefault-integer-8’ and ‘-fdefault-real-8’. d15236 14 a15249 14 ‘Integer’ ‘Integer*1’, ‘Integer*2’, ‘Integer*4’, ‘Integer*8’, and ‘Integer’ = ‘Integer*4’. ‘Logical’ ‘Logical*1’, ‘Logical*2’, ‘Logical*4’, ‘Logical*8’, and ‘Logical’ = ‘Logical*4’. ‘Real’ ‘Real*4’, ‘Real*8’, ‘Real*16’, and ‘Real’ = ‘Real*4’. ‘Complex’ ‘Complex*4’, ‘Complex*8’, ‘Complex*16’, and ‘Complex’ = ‘Complex*4’. d15258 1 a15258 1 ‘+’ is defined on numbers, but not on characters or other non- d15261 1 a15261 1 ‘**’ d15265 1 a15265 1 ‘:’ d15269 1 a15269 1 ‘%’ d15274 1 a15274 1 ‘::’ d15287 1 a15287 1 these procedures take an optional ‘KIND’ parameter, see *note Fortran d15290 1 a15290 1 ‘ABS(A)’ d15292 1 a15292 1 supported for ‘Complex’ arguments. d15294 1 a15294 1 ‘ALLOCATE(ARRAY)’ d15297 1 a15297 1 ‘ASSOCIATED(POINTER [, TARGET])’ d15301 1 a15301 1 ‘CEILING(A [, KIND])’ d15304 1 a15304 1 ‘Integer(KIND)’. d15306 1 a15306 1 ‘CMPLX(X [, Y [, KIND]])’ d15310 1 a15310 1 to ‘0.0’ except if X itself is of ‘Complex’ type. The optional d15312 1 a15312 1 ‘Complex(KIND)’. d15314 1 a15314 1 ‘FLOOR(A [, KIND])’ d15317 1 a15317 1 ‘Integer(KIND)’. d15319 1 a15319 1 ‘KIND(A)’ d15323 1 a15323 1 ‘LBOUND(ARRAY [, DIM [, KIND]])’ d15326 1 a15326 1 specifies the kind of the return type ‘Integer(KIND)’. d15328 2 a15329 2 ‘LOC(X)’ Returns the address of X as an ‘Integer’. d15331 1 a15331 1 ‘MOD(A, P)’ d15334 1 a15334 1 ‘MODULO(A, P)’ d15337 2 a15338 2 ‘RANK(A)’ Returns the rank of a scalar or array (scalars have rank ‘0’). d15340 2 a15341 2 ‘SHAPE(A)’ Returns the shape of a scalar or array (scalars have shape ‘()’). d15343 1 a15343 1 ‘SIZE(ARRAY[, DIM [, KIND]])’ d15347 1 a15347 1 ‘Integer(KIND)’. d15349 1 a15349 1 ‘UBOUND(ARRAY [, DIM [, KIND]])’ d15352 1 a15352 1 specifies the kind of the return type ‘Integer(KIND)’. d15363 2 a15364 2 ‘info common [COMMON-NAME]’ This command prints the values contained in the Fortran ‘COMMON’ d15366 1 a15366 1 all ‘COMMON’ blocks visible at the current program location are d15368 2 a15369 2 ‘set fortran repack-array-slices [on|off]’ ‘show fortran repack-array-slices’ d15387 1 a15387 1 The default for this setting is ‘off’. d15399 1 a15399 1 The Pascal-specific command ‘set print pascal_static-members’ d15414 1 a15414 1 • Linespecs (*note Location Specifications::) are never relative to d15416 1 a15416 1 namespace of crates, somewhat similar to the way ‘extern crate’ d15420 2 a15421 2 ‘A’, module ‘B’, then ‘break B::f’ will attempt to set a breakpoint in a function named ‘f’ in a crate named ‘B’. d15424 1 a15424 1 items using ‘self::’ or ‘super::’. d15426 1 a15426 1 • Because GDB implements Rust name-lookup semantics in expressions, d15428 2 a15429 2 example, if GDB is stopped at a breakpoint in the crate ‘K’, then ‘print ::x::y’ will try to find the symbol ‘K::x::y’. d15432 2 a15433 2 when debugging, GDB provides the ‘extern’ extension to circumvent this. To use the extension, just put ‘extern’ before a path d15436 2 a15437 2 In the above example, if you wanted to refer to the symbol ‘y’ in the crate ‘x’, you would use ‘print extern x::y’. d15439 2 a15440 2 • The Rust expression evaluator does not support "statement-like" expressions such as ‘if’ or ‘match’, or lambda expressions. d15442 1 a15442 1 • Tuple expressions are not implemented. d15444 2 a15445 2 • The Rust expression evaluator does not currently implement the ‘Drop’ trait. Objects that may be created by the evaluator will d15448 1 a15448 1 • GDB does not implement type inference for generics. In order to d15452 1 a15452 1 • GDB currently uses the C++ demangler for Rust. In most cases this d15455 1 a15455 1 results. This happens because Rust requires the ‘::’ operator d15457 2 a15458 2 GDB might provide a completion like ‘crate::f’, where the parser would require ‘crate::f::’. d15460 1 a15460 1 • As of this writing, the Rust compiler (version 1.8) has a few holes d15464 1 a15464 1 • Method calls cannot be made via traits. d15466 1 a15466 1 • Operator overloading is not implemented. d15468 1 a15468 1 • When debugging in a monomorphized function, you cannot use the d15471 1 a15471 1 • The type ‘Self’ is not available. d15473 1 a15473 1 • ‘use’ statements are not available, so some names may not be d15497 1 a15497 1 * M2 Scope:: The scope operators ‘::’ and ‘.’ d15507 1 a15507 1 ‘+’ is defined on numbers, but not on structures. Operators are often d15511 1 a15511 1 • _Integral types_ consist of ‘INTEGER’, ‘CARDINAL’, and their d15514 1 a15514 1 • _Character types_ consist of ‘CHAR’ and its subranges. d15516 1 a15516 1 • _Floating-point types_ consist of ‘REAL’. d15518 1 a15518 1 • _Pointer types_ consist of anything declared as ‘POINTER TO TYPE’. d15520 1 a15520 1 • _Scalar types_ consist of all of the above. d15522 1 a15522 1 • _Set types_ consist of ‘SET’ and ‘BITSET’ types. d15524 1 a15524 1 • _Boolean types_ consist of ‘BOOLEAN’. d15529 1 a15529 1 ‘,’ d15532 2 a15533 2 ‘:=’ Assignment. The value of VAR ‘:=’ VALUE is VALUE. d15535 1 a15535 1 ‘<, >’ d15539 1 a15539 1 ‘<=, >=’ d15542 1 a15542 1 Same precedence as ‘<’. d15544 1 a15544 1 ‘=, <>, #’ d15546 2 a15547 2 types. Same precedence as ‘<’. In GDB scripts, only ‘<>’ is available for inequality, since ‘#’ conflicts with the script d15550 1 a15550 1 ‘IN’ d15552 1 a15552 1 members. Same precedence as ‘<’. d15554 1 a15554 1 ‘OR’ d15557 1 a15557 1 ‘AND, &’ d15560 1 a15560 1 ‘@@’ d15564 1 a15564 1 ‘+, -’ d15568 1 a15568 1 ‘*’ d15572 1 a15572 1 ‘/’ d15574 1 a15574 1 set types. Same precedence as ‘*’. d15576 1 a15576 1 ‘DIV, MOD’ d15578 1 a15578 1 precedence as ‘*’. d15580 2 a15581 2 ‘-’ Negative. Defined on ‘INTEGER’ and ‘REAL’ data. d15583 1 a15583 1 ‘^’ d15586 1 a15586 1 ‘NOT’ d15588 1 a15588 1 ‘^’. d15590 3 a15592 3 ‘.’ ‘RECORD’ field selector. Defined on ‘RECORD’ data. Same precedence as ‘^’. d15594 2 a15595 2 ‘[]’ Array indexing. Defined on ‘ARRAY’ data. Same precedence as ‘^’. d15597 3 a15599 3 ‘()’ Procedure argument list. Defined on ‘PROCEDURE’ objects. Same precedence as ‘^’. d15601 1 a15601 1 ‘::, .’ d15605 2 a15606 2 supported, so GDB treats the use of the operator ‘IN’, or the use of operators ‘+’, ‘-’, ‘*’, ‘/’, ‘=’, , ‘<>’, ‘#’, ‘<=’, and ‘>=’ d15619 1 a15619 1 represents an ‘ARRAY’ variable. d15622 1 a15622 1 represents a ‘CHAR’ constant or variable. d15630 1 a15630 1 ‘SET OF MTYPE’ (where MTYPE is the type of M). d15652 1 a15652 1 ‘ABS(N)’ d15655 1 a15655 1 ‘CAP(C)’ d15659 1 a15659 1 ‘CHR(I)’ d15662 1 a15662 1 ‘DEC(V)’ d15666 1 a15666 1 ‘DEC(V,I)’ d15670 1 a15670 1 ‘EXCL(M,S)’ d15673 1 a15673 1 ‘FLOAT(I)’ d15676 1 a15676 1 ‘HIGH(A)’ d15679 1 a15679 1 ‘INC(V)’ d15683 1 a15683 1 ‘INC(V,I)’ d15687 1 a15687 1 ‘INCL(M,S)’ d15691 1 a15691 1 ‘MAX(T)’ d15694 1 a15694 1 ‘MIN(T)’ d15697 1 a15697 1 ‘ODD(I)’ d15700 1 a15700 1 ‘ORD(X)’ d15707 1 a15707 1 ‘SIZE(X)’ d15711 1 a15711 1 ‘TRUNC(R)’ d15714 1 a15714 1 ‘TSIZE(X)’ d15718 1 a15718 1 ‘VAL(T,I)’ d15722 1 a15722 1 treats the use of procedures ‘INCL’ and ‘EXCL’ as an error. d15733 1 a15733 1 • Integer constants are simply a sequence of digits. When used in an d15736 1 a15736 1 a trailing ‘H’, and octal integers by a trailing ‘B’. d15738 1 a15738 1 • Floating point constants appear as a sequence of digits, followed d15740 2 a15741 2 exponent can then be specified, in the form ‘E[+|-]NNN’, where ‘[+|-]NNN’ is the desired exponent. All of the digits of the d15744 2 a15745 2 • Character constants consist of a single character enclosed by a pair of like quotes, either single (‘'’) or double (‘"’). They may d15747 1 a15747 1 usually) followed by a ‘C’. d15749 2 a15750 2 • String constants consist of a sequence of characters enclosed by a pair of like quotes, either single (‘'’) or double (‘"’). Escape d15755 1 a15755 1 • Enumerated constants consist of an enumerated identifier. d15757 1 a15757 1 • Boolean constants consist of the identifiers ‘TRUE’ and ‘FALSE’. d15759 1 a15759 1 • Pointer constants consist of integral values only. d15761 1 a15761 1 • Set constants are not yet supported. d15781 2 a15782 2 and you can request GDB to interrogate the type and value of ‘r’ and ‘s’. d15793 1 a15793 1 Likewise if your source code declares ‘s’ as: d15798 1 a15798 1 then you may query the type of ‘s’ by: d15818 1 a15818 1 arrays have a lower bound of zero and not ‘-10’ as in the example above. d15839 1 a15839 1 Observe that the contents are written in the same way as their ‘C’ d15861 1 a15861 1 and you can request that GDB describes the type of ‘s’. d15881 1 a15881 1 and you can ask GDB to describe the type of ‘s’ as shown below. d15897 1 a15897 1 default to ‘on’ whenever the working language changes to Modula-2. This d15901 1 a15901 1 code compiled from a file whose name ends with ‘.mod’ sets the working d15914 1 a15914 1 • Unlike in standard Modula-2, pointer constants can be formed by d15921 1 a15921 1 • C escape sequences can be used in strings and characters to d15924 1 a15924 1 are printed using the ‘CHR(NNN)’ format. d15926 1 a15926 1 • The assignment operator (‘:=’) returns the value of its right-hand d15929 1 a15929 1 • All built-in procedures both modify _and_ return their argument. d15942 2 a15943 2 • They are of types that have been declared equivalent via a ‘TYPE T1 = T2’ statement d15945 1 a15945 1 • They have been declared on the same line. (Note: This is true of d15958 1 a15958 1 15.4.9.8 The Scope Operators ‘::’ and ‘.’ d15962 1 a15962 1 (‘.’) and the GDB scope operator (‘::’). The two have similar syntax: d15972 1 a15972 1 Using the ‘::’ operator makes GDB search the scope specified by SCOPE d15976 1 a15976 1 Using the ‘.’ operator makes GDB search the current scope for the d15989 3 a15991 3 Five subcommands of ‘set print’ and ‘show print’ apply specifically to C and C++: ‘vtbl’, ‘demangle’, ‘asm-demangle’, ‘object’, and ‘union’. The first four apply to C++, and the last to the C ‘union’ type, which has d15994 1 a15994 1 The ‘@@’ operator (*note Expressions: Expressions.), while available d15996 1 a15996 1 the debugging of “dynamic arrays”, which cannot be created in Modula-2 d15998 1 a15998 1 by an integral constant, the construct ‘{TYPE}ADREXP’ is still useful. d16000 2 a16001 2 In GDB scripts, the Modula-2 inequality operator ‘#’ is interpreted as the beginning of a comment. Use ‘<>’ instead. d16042 1 a16042 1 • That GDB should provide basic literals and access to operations for d16048 1 a16048 1 • That type safety and strict adherence to Ada language restrictions d16051 1 a16051 1 • That brevity is important to the GDB user. d16064 1 a16064 1 mostly for documenting command files. The standard GDB comment (‘#’) d16076 1 a16076 1 • Only a subset of the attributes are supported: d16078 1 a16078 1 − 'First, 'Last, and 'Length on array objects (not on types and d16081 1 a16081 1 − 'Min and 'Max. d16083 1 a16083 1 − 'Pos and 'Val. d16085 1 a16085 1 − 'Tag. d16087 2 a16088 2 − 'Range on array objects (not subtypes), but only as the right operand of the membership (‘in’) operator. d16090 1 a16090 1 − 'Access, 'Unchecked_Access, and 'Unrestricted_Access (a GNAT d16093 1 a16093 1 − 'Address. d16095 1 a16095 1 • The names in ‘Characters.Latin_1’ are not available. d16097 1 a16097 1 • Equality tests (‘=’ and ‘/=’) on arrays test for bitwise equality d16106 2 a16107 2 • The other component-by-component array operations (‘and’, ‘or’, ‘xor’, ‘not’, and relational tests other than equality) are not d16110 1 a16110 1 • There is limited support for array and record aggregates. They are d16126 1 a16126 1 ‘A_Rec’ declared to have a type such as: d16133 1 a16133 1 you can assign a value with a different size of ‘Vals’ with two d16141 2 a16142 2 components of an array or record aggregate (such as the ‘Len’ component in the assignment to ‘A_Rec’ above); they will retain d16148 1 a16148 1 • Calls to dispatching subprograms are not implemented. d16150 1 a16150 1 • The overloading algorithm is much more limited (i.e., less d16157 1 a16157 1 • The ‘new’ operator is not implemented. d16159 1 a16159 1 • Entry calls are not implemented. d16161 1 a16161 1 • Aside from printing, arithmetic operations on the native VAX d16164 1 a16164 1 • It is not possible to slice a packed array. d16166 2 a16167 2 • The names ‘True’ and ‘False’, when not part of a qualified name, are interpreted as if implicitly prefixed by ‘Standard’, regardless d16172 1 a16172 1 • Based real literals are not implemented. d16183 1 a16183 1 • If the expression E is a variable residing in memory (typically a d16185 1 a16185 1 ‘E@@N’ displays the values of E and the N-1 adjacent variables d16192 1 a16192 1 • ‘B::VAR’ means "the variable named VAR that appears in function or d16196 1 a16196 1 • The expression ‘{TYPE} ADDR’ means "the variable of type TYPE that d16199 1 a16199 1 • A name starting with ‘$’ is a convenience variable (*note d16205 1 a16205 1 • The assignment statement is allowed as an expression, returning its d16211 1 a16211 1 • The semicolon is allowed as an "operator," returning as its value d16218 1 a16218 1 • An extension to based literals can be used to specify the exact d16220 4 a16223 4 use from zero to two ‘l’ characters, followed by an ‘f’. The number of ‘l’ characters controls the width of the resulting real constant: zero means ‘Float’ is used, one means ‘Long_Float’, and two means ‘Long_Long_Float’. d16228 1 a16228 1 • Rather than use catenation and symbolic character names to d16231 1 a16231 1 sequence of characters of the form ‘["XX"]’ within a string or d16233 1 a16233 1 encoding is XX in hexadecimal. The sequence of characters ‘["""]’ d16236 1 a16236 1 contains an ASCII newline character (‘Ada.Characters.Latin_1.LF’) d16239 1 a16239 1 • The subtype used as a prefix for the attributes 'Pos, 'Min, and d16245 1 a16245 1 • When printing arrays, GDB uses positional notation when the array d16253 1 a16253 1 ‘=>’ clause. d16255 1 a16255 1 • You may abbreviate attributes in expressions with any unique, d16260 1 a16260 1 • Since Ada is case-insensitive, the debugger normally maps d16268 1 a16268 1 • Printing an object of class-wide type or dereferencing an d16285 1 a16285 1 ‘call’ command, and functions to procedures elsewhere. d16299 1 a16299 1 evaluation (type ‘0’ and press ) or to continue evaluation with a d16305 1 a16305 1 ‘set ada print-signatures’ d16307 1 a16307 1 overloads selection menus. It is ‘on’ by default. *Note d16310 1 a16310 1 ‘show ada print-signatures’ d16324 2 a16325 2 ‘adainit’. To run your program up to the beginning of elaboration, simply use the following two commands: ‘tbreak adainit’ and ‘run’. d16335 3 a16337 3 ‘info exceptions’ ‘info exceptions REGEXP’ The ‘info exceptions’ command allows you to list all Ada exceptions d16370 1 a16370 1 ‘info tasks’ d16400 1 a16400 1 ‘Unactivated’ d16404 1 a16404 1 ‘Runnable’ d16409 1 a16409 1 ‘Terminated’ d16414 1 a16414 1 ‘Child Activation Wait’ d16418 1 a16418 1 ‘Accept or Select Term’ d16422 1 a16422 1 ‘Waiting on entry call’ d16425 1 a16425 1 ‘Async Select Wait’ d16429 1 a16429 1 ‘Delay Sleep’ d16433 1 a16433 1 ‘Child Termination Wait’ d16439 1 a16439 1 ‘Wait Child in Term Alt’ d16443 1 a16443 1 ‘Asynchronous Hold’ d16445 1 a16445 1 ‘Ada.Asynchronous_Task_Control.Hold_Task’. d16447 1 a16447 1 ‘Activating’ d16450 1 a16450 1 ‘Selective Wait’ d16453 1 a16453 1 ‘Accepting RV with TASKNO’ d16456 1 a16456 1 ‘Waiting on RV with TASKNO’ d16463 1 a16463 1 ‘info task TASKNO’ d16479 1 a16479 1 ‘task’ d16489 2 a16490 2 ‘task TASKNO’ This command is like the ‘thread THREAD-ID’ command (*note d16508 3 a16510 3 ‘task apply [TASK-ID-LIST | all] [FLAG]... COMMAND’ The ‘task apply’ command is the Ada tasking analogue of ‘thread apply’ (*note Threads::). It allows you to apply the named COMMAND d16512 1 a16512 1 using a list of task IDs, or specify ‘all’ to apply to all tasks. d16516 3 a16518 3 with a ‘-’ directly followed by one letter in ‘qcs’. If several flags are provided, they must be given individually, such as ‘-c -q’. d16522 1 a16522 1 COMMAND will abort ‘task apply’. The following flags can be used d16525 3 a16527 3 ‘-c’ The flag ‘-c’, which stands for ‘continue’, causes any errors in COMMAND to be displayed, and the execution of ‘task apply’ d16529 2 a16530 2 ‘-s’ The flag ‘-s’, which stands for ‘silent’, causes any errors or d16534 2 a16535 2 ‘-q’ The flag ‘-q’ (‘quiet’) disables printing the task d16538 1 a16538 1 Flags ‘-c’ and ‘-s’ cannot be used together. d16540 3 a16542 3 ‘break LOCSPEC task TASKNO’ ‘break LOCSPEC task TASKNO if ...’ These commands are like the ‘break ... thread ...’ command (*note d16546 1 a16546 1 Use the qualifier ‘task TASKNO’ with a breakpoint command to d16550 1 a16550 1 column of the ‘info tasks’ display. d16552 1 a16552 1 If you do not specify ‘task TASKNO’ when you set a breakpoint, the d16555 3 a16557 3 You can use the ‘task’ qualifier on conditional breakpoints as well; in this case, place ‘task TASKNO’ before the breakpoint condition (before the ‘if’). d16597 1 a16597 1 privileges, using the command ‘"set write on"’ (*note Patching::). d16607 1 a16607 1 The “Ravenscar Profile” is a subset of the Ada tasking features, d16611 1 a16611 1 ‘set ravenscar task-switching on’ d16615 1 a16615 1 ‘set ravenscar task-switching off’ d16623 1 a16623 1 ‘show ravenscar task-switching’ d16634 1 a16634 1 the output of ‘info threads’: d16647 2 a16648 2 sequence. If you need to debug this code, you should use ‘set ravenscar task-switching off’. d16660 1 a16660 1 ‘set ada source-charset CHARSET’ d16665 1 a16665 1 ‘ISO-8859-1’, because that is also GNAT's default. d16667 1 a16667 1 ‘show ada source-charset’ d16681 1 a16681 1 • Static constants that the compiler chooses not to materialize as d16684 1 a16684 1 • Named parameter associations in function argument lists are ignored d16687 1 a16687 1 • Many useful library packages are currently invisible to the d16690 1 a16690 1 • Fixed-point arithmetic, conversions, input, and output is carried d16694 1 a16694 1 • The GNAT compiler never generates the prefix ‘Standard’ for any of d16701 1 a16701 1 ‘Standard’, GNAT's lack of qualification here can cause confusion. d16703 1 a16703 1 qualifying the problematic names with package ‘Standard’ d16712 1 a16712 1 ‘set ada trust-PAD-over-XVS on’ d16714 2 a16715 2 the value of Ada entities, particularly when ‘PAD’ and ‘PAD___XVS’ types are involved (see ‘ada/exp_dbug.ads’ in the GCC sources for a d16719 1 a16719 1 ‘set ada trust-PAD-over-XVS off’ d16722 4 a16725 4 ‘ada trust-PAD-over-XVS’ to ‘off’ activates a work-around which may fix the issue. It is always safe to set ‘ada trust-PAD-over-XVS’ to ‘off’, but this incurs a slight performance penalty, so it is recommended to leave this setting to ‘on’ unless necessary. d16728 2 a16729 2 number of conventions known as the ‘GNAT Encoding’, all documented in ‘gcc/ada/exp_dbug.ads’ in the GCC sources. This encoding describes how d16731 1 a16731 1 particular, this convention makes use of “descriptive types”, which are d16743 1 a16743 1 ‘maintenance ada set ignore-descriptive-types [on|off]’ d16745 1 a16745 1 default is not to ignore descriptives types (‘off’). d16747 1 a16747 1 ‘maintenance ada show ignore-descriptive-types’ d16757 1 a16757 1 provides a pseudo-language, called ‘minimal’. It does not represent a d16763 1 a16763 1 If the language is set to ‘auto’, GDB will automatically select this d16785 2 a16786 2 typical file name, like ‘foo.c’, as the three words ‘foo’ ‘.’ ‘c’. To allow GDB to recognize ‘foo.c’ as a single symbol, enclose it in single d16791 1 a16791 1 looks up the value of ‘x’ in the scope of the file ‘foo.c’. d16793 3 a16795 3 ‘set case-sensitive on’ ‘set case-sensitive off’ ‘set case-sensitive auto’ d16798 4 a16801 4 Occasionally, you may wish to control that. The command ‘set case-sensitive’ lets you do that by specifying ‘on’ for case-sensitive matches or ‘off’ for case-insensitive ones. If you specify ‘auto’, case sensitivity is reset to the default suitable d16806 1 a16806 1 ‘show case-sensitive’ d16810 3 a16812 3 ‘set print type methods’ ‘set print type methods on’ ‘set print type methods off’ d16815 3 a16817 3 appropriate flag to ‘ptype’, or using ‘set print type methods’. Specifying ‘on’ will cause GDB to display the methods; this is the default. Specifying ‘off’ will cause GDB to omit the methods. d16819 1 a16819 1 ‘show print type methods’ d16823 2 a16824 2 ‘set print type nested-type-limit LIMIT’ ‘set print type nested-type-limit unlimited’ d16826 1 a16826 1 show. A LIMIT of ‘unlimited’ or ‘-1’ will show all nested d16830 1 a16830 1 ‘show print type nested-type-limit’ d16834 3 a16836 3 ‘set print type typedefs’ ‘set print type typedefs on’ ‘set print type typedefs off’ d16840 3 a16842 3 appropriate flag to ‘ptype’, or using ‘set print type typedefs’. Specifying ‘on’ will cause GDB to display the typedef definitions; this is the default. Specifying ‘off’ will cause GDB to omit the d16847 1 a16847 1 ‘show print type typedefs’ d16851 3 a16853 3 ‘set print type hex’ ‘set print type hex on’ ‘set print type hex off’ d16857 2 a16858 2 the other either by passing the appropriate flag to ‘ptype’, or by using the ‘set print type hex’ command. d16860 1 a16860 1 ‘show print type hex’ d16864 1 a16864 1 ‘info address SYMBOL’ d16870 1 a16870 1 Note the contrast with ‘print &SYMBOL’, which does not work at all d16874 1 a16874 1 ‘info symbol ADDR’ d16882 1 a16882 1 This is the opposite of the ‘info address’ command. You can use it d16893 1 a16893 1 ‘demangle [-l LANGUAGE] [--] NAME’ d16898 1 a16898 1 The ‘--’ option specifies the end of options, and is useful when d16901 1 a16901 1 The parameter ‘demangle-style’ specifies how to interpret the kind d16904 1 a16904 1 ‘whatis[/FLAGS] [ARG]’ d16906 1 a16906 1 name of a data type. With no argument, print the data type of ‘$’, d16913 1 a16913 1 If ARG is a variable or an expression, ‘whatis’ prints its literal d16915 10 a16924 10 using a ‘typedef’, ‘whatis’ will _not_ print the data type underlying the ‘typedef’. If the type of the variable or the expression is a compound data type, such as ‘struct’ or ‘class’, ‘whatis’ never prints their fields or methods. It just prints the ‘struct’/‘class’ name (a.k.a. its “tag”). If you want to see the members of such a compound data type, use ‘ptype’. If ARG is a type name that was defined using ‘typedef’, ‘whatis’ “unrolls” only one level of that ‘typedef’. Unrolling means that ‘whatis’ will show the underlying type used in the ‘typedef’ d16926 1 a16926 1 ‘typedef’, ‘whatis’ will not unroll it. d16928 3 a16930 3 For C code, the type names may also have the form ‘class CLASS-NAME’, ‘struct STRUCT-TAG’, ‘union UNION-TAG’ or ‘enum ENUM-TAG’. d16935 1 a16935 1 ‘r’ d16938 1 a16938 1 class' members. The ‘/r’ flag disables this. d16940 1 a16940 1 ‘m’ d16943 1 a16943 1 ‘M’ d16945 2 a16946 2 the flag exists in case you change the default with ‘set print type methods’. d16948 1 a16948 1 ‘t’ d16954 1 a16954 1 ‘T’ d16956 2 a16957 2 the flag exists in case you change the default with ‘set print type typedefs’. d16959 1 a16959 1 ‘o’ d16961 1 a16961 1 what the ‘pahole’ tool does. This option implies the ‘/tm’ d16964 1 a16964 1 ‘x’ d16968 1 a16968 1 ‘d’ d17006 1 a17006 1 Issuing a ‘ptype /o struct tuv’ command would print: d17019 1 a17019 1 can find two parts separated by the ‘|’ character: the d17058 1 a17058 1 In this case, since ‘struct tuv’ and ‘struct xyz’ occupy the d17085 2 a17086 2 ‘ptype[/FLAGS] [ARG]’ ‘ptype’ accepts the same arguments as ‘whatis’, but prints a d17090 1 a17090 1 Contrary to ‘whatis’, ‘ptype’ always unrolls any ‘typedef’s in its d17092 1 a17092 1 expression, or a data type. This means that ‘ptype’ of a variable d17094 4 a17097 4 the source code--use ‘whatis’ for that. ‘typedef’s at the pointer or reference targets are also unrolled. Only ‘typedef’s of fields, methods and inner ‘class typedef’s of ‘struct’s, ‘class’es and ‘union’s are not unrolled even with ‘ptype’. d17130 2 a17131 2 As with ‘whatis’, using ‘ptype’ without an argument refers to the type of ‘$’, the last value in the value history. d17136 1 a17136 1 declaration of the data type, it will say ‘’. For d17142 1 a17142 1 but no definition for ‘struct foo’ itself, GDB will say: d17165 1 a17165 1 ‘info types [-q] [REGEXP]’ d17169 4 a17172 4 it were a complete line; thus, ‘i type value’ gives information on all types in your program whose names include the string ‘value’, but ‘i type ^value$’ gives information only on types whose complete name is ‘value’. d17175 2 a17176 2 print the type description according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language Automatically: d17181 2 a17182 2 This command differs from ‘ptype’ in two ways: first, like ‘whatis’, it does not print a detailed description; second, it d17185 3 a17187 3 The output from ‘into types’ is proceeded with a header line describing what types are being listed. The optional flag ‘-q’, which stands for ‘quiet’, disables printing this header d17190 1 a17190 1 ‘info type-printers’ d17192 1 a17192 1 "type printers" available. When using ‘ptype’ or ‘whatis’, these d17196 1 a17196 1 ‘info type-printers’ displays all the available type printers. d17198 2 a17199 2 ‘enable type-printer NAME...’ ‘disable type-printer NAME...’ d17202 1 a17202 1 ‘info scope LOCSPEC’ d17219 1 a17219 1 collect during a “trace experiment”, see *note collect: Tracepoint d17222 1 a17222 1 ‘info source’ d17225 5 a17229 5 • the name of the source file, and the directory containing it, • the directory it was compiled in, • its length, in lines, • which programming language it is written in, • if the debug information provides it, the program that d17232 1 a17232 1 • whether the executable includes debugging information for that d17235 1 a17235 1 • whether the debugging information includes information about d17238 1 a17238 1 ‘info sources [-dirname | -basename] [--] [REGEXP]’ d17240 1 a17240 1 With no options ‘info sources’ prints the names of all source files d17253 1 a17253 1 case-insensitive filesystem (e.g., MS-Windows). ‘--’ can be used d17255 1 a17255 1 option (e.g. if REGEXP starts with ‘-’). d17258 2 a17259 2 If ‘-dirname’, only files having a dirname matching REGEXP are shown. If ‘-basename’, only files having a basename matching d17267 1 a17267 1 ‘info functions [-q] [-n]’ d17269 1 a17269 1 to ‘info types’, this command groups its output by source files and d17273 2 a17274 2 print the function name and type according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language d17279 1 a17279 1 The ‘-n’ flag excludes “non-debugging symbols” from the results. A d17284 1 a17284 1 The optional flag ‘-q’, which stands for ‘quiet’, disables printing d17288 2 a17289 2 ‘info functions [-q] [-n] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info functions’, but only print the names and data types of d17293 3 a17295 3 the regular expression REGEXP. Thus, ‘info fun step’ finds all functions whose names include ‘step’; ‘info fun ^step’ finds those whose names start with ‘step’. If a function name contains d17297 1 a17297 1 ‘operator*()’), they may be quoted with a backslash. d17300 1 a17300 1 as printed by the ‘whatis’ command, match the regular expression d17303 5 a17307 5 the meaning of special characters or quotes. Thus, ‘info fun -t '^int ('’ finds the functions that return an integer; ‘info fun -t '(.*int.*'’ finds the functions that have an argument type containing int; ‘info fun -t '^int (' ^step’ finds the functions whose names start with ‘step’ and that return int. d17312 1 a17312 1 ‘info variables [-q] [-n]’ d17319 2 a17320 2 print the variable name and type according to the ‘set language’ value: using ‘set language auto’ (see *note Set Language d17325 1 a17325 1 The ‘-n’ flag excludes non-debugging symbols from the results. d17327 1 a17327 1 The optional flag ‘-q’, which stands for ‘quiet’, disables printing d17331 2 a17332 2 ‘info variables [-q] [-n] [-t TYPE_REGEXP] [REGEXP]’ Like ‘info variables’, but only print the variables selected with d17339 1 a17339 1 as printed by the ‘whatis’ command, match the regular expression d17347 1 a17347 1 ‘info modules [-q] [REGEXP]’ d17351 1 a17351 1 The optional flag ‘-q’, which stands for ‘quiet’, disables printing d17355 2 a17356 2 ‘info module functions [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]’ ‘info module variables [-q] [-m MODULE-REGEXP] [-t TYPE-REGEXP] [REGEXP]’ d17366 1 a17366 1 The optional flag ‘-q’, which stands for ‘quiet’, disables printing d17370 1 a17370 1 ‘info main’ d17375 2 a17376 2 ‘info classes’ ‘info classes REGEXP’ d17381 2 a17382 2 ‘info selectors’ ‘info selectors REGEXP’ d17387 1 a17387 1 ‘set opaque-type-resolution on’ d17389 3 a17391 3 declared as a pointer to a ‘struct’, ‘class’, or ‘union’--for example, ‘struct MyType *’--that is used in one source file although the full declaration of ‘struct MyType’ is in another d17397 1 a17397 1 ‘set opaque-type-resolution off’ d17402 1 a17402 1 ‘show opaque-type-resolution’ d17405 5 a17409 5 ‘set print symbol-loading’ ‘set print symbol-loading full’ ‘set print symbol-loading brief’ ‘set print symbol-loading off’ The ‘set print symbol-loading’ command allows you to control the d17414 1 a17414 1 messages can be annoying. When set to ‘brief’ a message is printed d17417 1 a17417 1 number of shared libraries. When set to ‘off’ no messages are d17420 1 a17420 1 ‘show print symbol-loading’ d17424 5 a17428 5 ‘maint print symbols [-pc ADDRESS] [FILENAME]’ ‘maint print symbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]’ ‘maint print psymbols [-objfile OBJFILE] [-pc ADDRESS] [--] [FILENAME]’ ‘maint print psymbols [-objfile OBJFILE] [-source SOURCE] [--] [FILENAME]’ ‘maint print msymbols [-objfile OBJFILE] [--] [FILENAME]’ d17430 2 a17431 2 terminal if FILENAME is unspecified. If ‘-objfile OBJFILE’ is specified, only dump symbols for that objfile. If ‘-pc ADDRESS’ is d17433 2 a17434 2 address. Note that ADDRESS may be a symbol like ‘main’. If ‘-source SOURCE’ is specified, only dump symbols for that source d17438 4 a17441 4 These commands do not modify internal GDB state, therefore ‘maint print symbols’ will only print symbols for already expanded symbol tables. You can use the command ‘info sources’ to find out which files these are. If you use ‘maint print psymbols’ instead, the d17444 1 a17444 1 but not yet read completely. Finally, ‘maint print msymbols’ just d17448 1 a17448 1 reads symbols (in the description of ‘symbol-file’). d17450 2 a17451 2 ‘maint info symtabs [ REGEXP ]’ ‘maint info psymtabs [ REGEXP ]’ d17453 1 a17453 1 List the ‘struct symtab’ or ‘struct partial_symtab’ structures d17475 1 a17475 1 contains the string ‘dwarf2read’, belonging to the ‘gdb’ d17497 1 a17497 1 ‘maint info line-table [ REGEXP ]’ d17499 1 a17499 1 List the ‘struct linetable’ from all ‘struct symtab’ instances d17501 1 a17501 1 ‘struct linetable’ from all ‘struct symtab’. For example: d17521 1 a17521 1 The ‘IS-STMT’ column indicates if the address is a recommended d17523 1 a17523 1 ‘PROLOGUE-END’ column indicates that a given address is an adequate d17525 1 a17525 1 function prologue. The ‘EPILOGUE-BEGIN’ column indicates that a d17529 2 a17530 2 ‘set always-read-ctf [on|off]’ ‘show always-read-ctf’ d17536 1 a17536 1 ‘maint set symbol-cache-size SIZE’ d17541 1 a17541 1 ‘maint show symbol-cache-size’ d17544 1 a17544 1 ‘maint print symbol-cache’ d17548 1 a17548 1 ‘maint print symbol-cache-statistics’ d17552 2 a17553 2 ‘maint flush symbol-cache’ ‘maint flush-symbol-cache’ d17556 7 a17562 7 useful when collecting performance data. The command ‘maint flush-symbol-cache’ is deprecated in favor of ‘maint flush symbol-cache’.. ‘maint set ignore-prologue-end-flag [on|off]’ Enable or disable the use of the ‘PROLOGUE-END’ flag from the line-table. When ‘off’ (the default), GDB uses the ‘PROLOGUE-END’ d17564 1 a17564 1 When ‘on’, GDB ignores the flag and relies on prologue analyzers to d17567 2 a17568 2 ‘maint show ignore-prologue-end-flag’ Show whether GDB will ignore the ‘PROLOGUE-END’ flag. d17607 1 a17607 1 stores the value 4 into the variable ‘x’, and then prints the value of d17613 2 a17614 2 the ‘set’ command instead of the ‘print’ command. ‘set’ is really the same as ‘print’ except that the expression's value is not printed and is d17618 6 a17623 6 If the beginning of the argument string of the ‘set’ command appears identical to a ‘set’ subcommand, use the ‘set variable’ command instead of just ‘set’. This command is identical to ‘set’ except for its lack of subcommands. For example, if your program has a variable ‘width’, you get an error if you try to set a new value with just ‘set width=13’, because GDB has the command ‘set width’: d17632 2 a17633 2 The invalid expression, of course, is ‘=47’. In order to actually set the program's variable ‘width’, use d17637 6 a17642 6 Because the ‘set’ command has many subcommands that can conflict with the names of program variables, it is a good idea to use the ‘set variable’ command instead of just ‘set’. For example, if your program has a variable ‘g’, you run into problems if you try to set a new value with just ‘set g=4’, because GDB has the command ‘set gnutarget’, abbreviated ‘set g’: d17660 2 a17661 2 The program variable ‘g’ did not change, and you silently set the ‘gnutarget’ to an invalid value. In order to set the variable ‘g’, use d17670 1 a17670 1 To store values into arbitrary places in memory, use the ‘{...}’ d17672 2 a17673 2 (*note Expressions: Expressions.). For example, ‘{int}0x83040’ refers to memory location ‘0x83040’ as an integer (which implies a certain size d17687 1 a17687 1 it stopped, with the ‘continue’ command. You can instead continue at an d17690 2 a17691 2 ‘jump LOCSPEC’ ‘j LOCSPEC’ d17699 2 a17700 2 is a breakpoint there. It is common practice to use the ‘tbreak’ command in conjunction with ‘jump’. *Note Setting Breakpoints: Set d17703 1 a17703 1 The ‘jump’ command does not change the current stack frame, or the d17709 1 a17709 1 ‘jump’ command requests confirmation if the jump address is not in d17714 2 a17715 2 On many systems, you can get much the same effect as the ‘jump’ command by storing a new value into the register ‘$pc’. The difference d17721 2 a17722 2 makes the next ‘continue’ command or stepping command execute at address ‘0x485’, rather than at the address where your program stopped. *Note d17725 2 a17726 2 However, writing directly to ‘$pc’ will only change the value of the program-counter register, while using ‘jump’ will ensure that any d17728 3 a17730 3 ‘jump’ will update both ‘$pc’ and ‘$npc’ registers prior to resuming execution. When using the approach of writing directly to ‘$pc’ it is your job to also update the ‘$npc’ register. d17732 1 a17732 1 The most common occasion to use the ‘jump’ command is to back d17742 1 a17742 1 ‘signal SIGNAL’ d17745 2 a17746 2 number of a signal. For example, on many systems ‘signal 2’ and ‘signal SIGINT’ are both ways of sending an interrupt signal. d17751 1 a17751 1 ‘continue’ command; ‘signal 0’ causes it to resume without a d17759 1 a17759 1 before issuing the ‘signal 0’ command. If you issue the ‘signal 0’ d17763 2 a17764 2 Invoking the ‘signal’ command is not the same as invoking the ‘kill’ utility from the shell. Sending a signal with ‘kill’ causes d17766 1 a17766 1 handling tables (*note Signals::). The ‘signal’ command passes the d17769 1 a17769 1 ‘signal’ does not repeat when you press a second time after d17772 1 a17772 1 ‘queue-signal SIGNAL’ d17775 2 a17776 2 number of a signal. For example, on many systems ‘signal 2’ and ‘signal SIGINT’ are both ways of sending an interrupt signal. The d17779 1 a17779 1 handling of signals from GDB with the ‘handle’ command (*note d17786 1 a17786 1 resumed with the ‘continue’ command. d17788 2 a17789 2 This command differs from the ‘signal’ command in that the signal is just queued, execution is not resumed. And ‘queue-signal’ d17791 1 a17791 1 to ‘nopass’ (*note Signals::). d17802 3 a17804 3 ‘return’ ‘return EXPRESSION’ You can cancel execution of a function call with the ‘return’ d17808 1 a17808 1 When you use ‘return’, GDB discards the selected stack frame (and all d17811 1 a17811 1 that value as the argument to ‘return’. d17819 1 a17819 1 The ‘return’ command does not resume execution; it leaves the program d17821 1 a17821 1 In contrast, the ‘finish’ command (*note Continuing and Stepping: d17830 2 a17831 2 point values in CPU registers. Larger integer widths (such as ‘long long int’) also have specific placement rules. GDB already knows the OS d17837 4 a17840 4 debug info is available. For example, if you type ‘return -1’, and the function in the current stack frame is declared to return a ‘long long int’, GDB transparently converts the implicit ‘int’ value of -1 into a ‘long long int’: d17854 2 a17855 2 caller code expects. For example, typing ‘return -1’ with its implicit type ‘int’ would set only a part of a ‘long long int’ result for a debug d17874 1 a17874 1 ‘print EXPR’ d17879 2 a17880 2 ‘call EXPR’ Evaluate the expression EXPR without displaying ‘void’ returned d17883 1 a17883 1 You can use this variant of the ‘print’ command if you want to d17885 2 a17886 2 (a.k.a. “a void function”), but without cluttering the output with ‘void’ returned values that GDB will otherwise print. If the d17889 1 a17889 1 It is possible for the function you call via the ‘print’ or ‘call’ d17892 1 a17892 1 controlled by the ‘set unwind-on-signal’ command. d17895 1 a17895 1 call via the ‘print’ or ‘call’ command to generate an exception that is d17901 1 a17901 1 controlled by the ‘set unwind-on-terminating-exception’ command. d17903 1 a17903 1 ‘set unwind-on-signal’ d17910 1 a17910 1 The command ‘set unwindonsignal’ is an alias for this command, and d17913 1 a17913 1 ‘show unwind-on-signal’ d17917 1 a17917 1 The command ‘show unwindonsignal’ is an alias for this command, and d17920 1 a17920 1 ‘set unwind-on-terminating-exception’ d17928 1 a17928 1 ‘show unwind-on-terminating-exception’ d17932 1 a17932 1 ‘set unwind-on-timeout’ d17934 2 a17935 2 If set to ‘off’ (the default), GDB stops in the frame where the timeout occurred. If set to ‘on’, GDB unwinds the stack it created d17939 1 a17939 1 ‘show unwind-on-timeout’ d17943 1 a17943 1 ‘set may-call-functions’ d17946 1 a17946 1 with expressions in the ‘print’ command. It defaults to ‘on’. d17957 1 a17957 1 ‘show may-call-functions’ d17963 1 a17963 1 call by typing the interrupt character (often ‘Ctrl-c’). d17967 2 a17968 2 due to ‘set unwind-on-terminating-exception on’, ‘set unwind-on-timeout on’, or ‘set unwind-on-signal on’ (*note stack unwind settings::), then d17970 1 a17970 1 function, will be visible in the backtrace, for example frame ‘#3’ in d17985 1 a17985 1 to resume the inferior (using commands like ‘continue’, ‘step’, etc). d17996 1 a17996 1 this behaviour can be adjusted with ‘set unwind-on-timeout’ (*note set d18002 2 a18003 2 ‘unlimited’, meaning GDB will wait indefinitely for function call to complete, unless interrupted by the user using ‘Ctrl-C’. d18005 1 a18005 1 ‘set direct-call-timeout SECONDS’ d18008 2 a18009 2 special value ‘unlimited’, which indicates no timeout should be used. The default for this setting is ‘unlimited’. d18012 1 a18012 1 the command prompt, for example with a ‘call’ or ‘print’ command. d18016 1 a18016 1 setting is treated as ‘unlimited’. d18018 1 a18018 1 ‘show direct-call-timeout’ d18020 1 a18020 1 ‘call’ or ‘print’ command. d18027 1 a18027 1 ‘set indirect-call-timeout SECONDS’ d18030 1 a18030 1 integer greater than zero, or the special value ‘unlimited’, which d18032 1 a18032 1 is ‘30’ seconds. d18036 1 a18036 1 setting is treated as ‘unlimited’. d18042 1 a18042 1 ‘show indirect-call-timeout’ d18111 1 a18111 1 explicitly with the ‘set write’ command. For example, you might want to d18114 4 a18117 4 ‘set write on’ ‘set write off’ If you specify ‘set write on’, GDB opens executable and core files for both reading and writing; if you specify ‘set write off’ (the d18121 1 a18121 1 the ‘exec-file’ or ‘core-file’ command) after changing ‘set write’, d18124 1 a18124 1 ‘show write’ d18135 1 a18135 1 running under GDB. GCC 5.0 or higher built with ‘libcc1.so’ must be d18139 2 a18140 2 ‘compile code SOURCE-CODE’ ‘compile code -raw -- SOURCE-CODE’ d18159 1 a18159 1 they may conflict. The ‘--’ delimiter can be used to separate d18165 1 a18165 1 To enter this mode, invoke the ‘compile code’ command without any d18168 1 a18168 1 required. When you have completed typing, enter ‘end’ on its own d18176 1 a18176 1 Specifying ‘-raw’, prohibits GDB from wrapping the provided d18179 3 a18181 3 ‘_gdb_expr_’. The ‘-raw’ code cannot access variables of the inferior. Using ‘-raw’ option may be needed for example when SOURCE-CODE requires ‘#include’ lines which may conflict with d18184 3 a18186 3 ‘compile file FILENAME’ ‘compile file -raw FILENAME’ Like ‘compile code’, but take the source code from FILENAME. d18190 2 a18191 2 ‘compile print [[OPTIONS] --] EXPR’ ‘compile print [[OPTIONS] --] /F EXPR’ d18195 1 a18195 1 can choose a different format by specifying ‘/F’, where F is a d18197 2 a18198 2 Formats. The ‘compile print’ command accepts the same options as the ‘print’ command; see *note print options::. d18200 2 a18201 2 ‘compile print [[OPTIONS] --]’ ‘compile print [[OPTIONS] --] /F’ d18204 1 a18204 1 ‘compile print’ command without any text following the command. d18209 1 a18209 1 ‘set debug compile’ d18213 1 a18213 1 ‘show debug compile’ d18217 1 a18217 1 ‘set debug compile-cplus-types’ d18221 1 a18221 1 ‘show debug compile-cplus-types’ d18225 1 a18225 1 17.7.1 Compilation options for the ‘compile’ command d18234 1 a18234 1 target architecture and OS options (‘gdbarch’) d18236 2 a18237 2 system, usually they specify at least 32-bit (‘-m32’) or 64-bit (‘-m64’) compilation option. d18241 4 a18244 4 into ‘DW_AT_producer’ part of DWARF debugging information according to the GCC option ‘-grecord-gcc-switches’. One has to explicitly specify ‘-g’ during inferior compilation otherwise GCC produces no DWARF. This feature is only relevant for platforms where ‘-g’ d18246 1 a18246 1 by using ‘-gdwarf-4’. d18248 1 a18248 1 compilation options set by ‘set compile-args’ d18252 1 a18252 1 ‘set compile-args’ d18254 1 a18254 1 the ‘compile’ commands. These options override any conflicting d18258 1 a18258 1 ‘show compile-args’ d18263 1 a18263 1 17.7.2 Caveats when using the ‘compile’ command d18266 1 a18266 1 There are a few caveats to keep in mind when using the ‘compile’ d18271 3 a18273 3 When the language in GDB is set to ‘C’, the compiler will attempt to compile the source code with a ‘C’ compiler. The source code provided to the ‘compile’ command will have much the same access to d18302 1 a18302 1 has been compiled, loaded into GDB, stopped at the function ‘main’, d18307 2 a18308 2 ‘compile’ command is not an exception to this rule. Without debug information, you can still use the ‘compile’ command, but you will d18312 1 a18312 1 debug information enabled. The ‘compile’ command will have access d18315 5 a18319 5 ‘main’ function, the ‘compile’ command would have access to the variable ‘k’. You could invoke the ‘compile’ command and type some source code to set the value of ‘k’. You can also read it, or do anything with that variable you would normally do in ‘C’. Be aware that changes to inferior variables in the ‘compile’ command are d18324 1 a18324 1 the variable ‘k’ is now 3. It will retain that value until d18326 1 a18326 1 ‘compile’ command changes it. d18329 3 a18331 3 injected by the ‘compile’ command. In the example, the variables ‘j’ and ‘k’ are not accessible yet, because the program is currently stopped in the ‘main’ function, where these variables are d18340 1 a18340 1 specify via the ‘compile’ command will be able to access them. d18342 1 a18342 1 You can create variables and types with the ‘compile’ command as d18344 1 a18344 1 part of the ‘compile’ command are not visible to the rest of the d18354 2 a18355 2 a compiler error would be raised as the variable ‘ff’ no longer exists. Object code generated and injected by the ‘compile’ d18358 1 a18358 1 the code submitted to the ‘compile’ command. This example is d18363 2 a18364 2 The value of the variable ‘ff’ is assigned to ‘k’. The variable ‘k’ does not require the existence of ‘ff’ to maintain the value it d18366 1 a18366 1 assignment. If the source code compiled with the ‘compile’ command d18368 1 a18368 1 a variable created in the ‘compile’ command, that pointer would d18374 1 a18374 1 In this example, ‘p’ would point to ‘ff’ when the ‘compile’ command d18377 1 a18377 1 variable ‘p’ would point to an invalid location when the command d18379 1 a18379 1 either assign ‘NULL’ to any assigned pointers, or restore a valid d18383 2 a18384 2 typedefs defined in ‘compile’ command. Types defined in the ‘compile’ command will no longer be available in the next ‘compile’ d18386 1 a18386 1 the ‘compile’ command, care must be taken to ensure that any future d18397 1 a18397 1 accessible to the code submitted to the ‘compile’ command. Access d18401 1 a18401 1 17.7.3 Compiler search for the ‘compile’ command d18406 1 a18406 1 running. Environment variable ‘PATH’ on GDB host is searched for GCC d18408 1 a18408 1 search can be overridden by ‘set compile-gcc’ GDB command below. ‘PATH’ d18410 1 a18410 1 command ‘set environment’). *Note Environment::. d18412 2 a18413 2 Specifically ‘PATH’ is searched for binaries matching regular expression ‘ARCH(-[^-]*)?-OS-gcc’ according to the inferior target being d18415 3 a18417 3 example both ‘i386’ and ‘x86_64’ targets look for pattern ‘(x86_64|i.86)’ and both ‘s390’ and ‘s390x’ targets look for pattern ‘s390x?’. OS is currently supported only for pattern ‘linux(-gnu)?’. d18420 1 a18420 1 library ‘libcc1.so’ from the compiler. It is searched in default shared d18422 3 a18424 3 ‘LD_LIBRARY_PATH’), unrelated to ‘PATH’ or ‘set compile-gcc’ settings. Contrary to it ‘libcc1plugin.so’ is found according to the installation of the found compiler -- as possibly specified by the ‘set compile-gcc’ d18427 1 a18427 1 ‘set compile-gcc’ d18429 1 a18429 1 the ‘compile’ commands. If this option is not set (it is set to an d18433 1 a18433 1 ‘show compile-gcc’ d18435 2 a18436 2 it is the main command ‘gcc’, found usually for example under name ‘x86_64-linux-gnu-gcc’. d18472 1 a18472 1 to use. Or you are debugging a remote target via ‘gdbserver’ (*note d18476 1 a18476 1 ‘file FILENAME’ d18479 1 a18479 1 program executed when you use the ‘run’ command. If you do not d18481 1 a18481 1 directory, GDB uses the environment variable ‘PATH’ as a list of d18484 1 a18484 1 both GDB and your program, using the ‘path’ command. d18489 1 a18489 1 You can load unlinked object ‘.o’ files into GDB using the ‘file’ d18492 2 a18493 2 underlying BFD functionality supports it, you could use ‘gdb -write’ to patch object files using this technique. Note that GDB d18498 2 a18499 2 ‘file’ ‘file’ with no argument makes GDB discard any information it has on d18502 1 a18502 1 ‘exec-file [ FILENAME ]’ d18504 1 a18504 1 found in FILENAME. GDB searches the environment variable ‘PATH’ if d18511 3 a18513 3 ‘symbol-file [ FILENAME [ -o OFFSET ]]’ Read symbol table information from file FILENAME. ‘PATH’ is searched when necessary. Use the ‘file’ command to get both symbol d18521 1 a18521 1 ‘symbol-file’ with no argument clears out GDB information on your d18524 1 a18524 1 The ‘symbol-file’ command causes GDB to forget the contents of some d18530 1 a18530 1 ‘symbol-file’ does not repeat if you press again after d18540 1 a18540 1 usually obtained from GNU compilers; for example, using ‘GCC’ you d18544 1 a18544 1 systems using COFF, the ‘symbol-file’ command does not normally d18553 1 a18553 1 source file are being read. (The ‘set verbose’ command can turn d18558 1 a18558 1 the symbol table is stored in COFF format, ‘symbol-file’ reads the d18563 2 a18564 2 ‘symbol-file [ -readnow ] FILENAME’ ‘file [ -readnow ] FILENAME’ d18566 1 a18566 1 tables by using the ‘-readnow’ option with any of the commands that d18570 2 a18571 2 ‘symbol-file [ -readnever ] FILENAME’ ‘file [ -readnever ] FILENAME’ d18573 1 a18573 1 contained in FILENAME by using the ‘-readnever’ option. *Note d18576 2 a18577 2 ‘core-file [FILENAME]’ ‘core’ d18583 1 a18583 1 ‘core-file’ with no argument specifies that no core file is to be d18589 1 a18589 1 in which the program is running. To do this, use the ‘kill’ d18592 2 a18593 2 ‘add-symbol-file FILENAME [ -readnow | -readnever ] [ -o OFFSET ] [ TEXTADDRESS ] [ -s SECTION ADDRESS ... ]’ The ‘add-symbol-file’ command reads additional symbol table d18599 1 a18599 1 sections using an arbitrary number of ‘-s SECTION ADDRESS’ pairs. d18609 2 a18610 2 originally read with the ‘symbol-file’ command. You can use the ‘add-symbol-file’ command any number of times; the new symbol data d18616 1 a18616 1 Changes can be reverted using the command ‘remove-symbol-file’. d18621 1 a18621 1 relocatable ‘.o’ files, as long as: d18623 1 a18623 1 • the file's symbolic information refers only to linker symbols d18626 1 a18626 1 • every section the file's symbolic information refers to has d18629 2 a18630 2 • you can determine the address at which every section was loaded, and provide these to the ‘add-symbol-file’ command. d18636 1 a18636 1 complex link procedures (‘.linkonce’ section factoring and C++ d18639 1 a18639 1 ‘add-symbol-file’ to read a relocatable object file's symbolic d18643 1 a18643 1 ‘add-symbol-file’ does not repeat if you press after using d18646 3 a18648 3 ‘remove-symbol-file FILENAME’ ‘remove-symbol-file -a ADDRESS’ Remove a symbol file added via the ‘add-symbol-file’ command. The d18662 1 a18662 1 ‘remove-symbol-file’ does not repeat if you press after using d18668 1 a18668 1 ‘add-symbol-file-from-memory ADDRESS’ d18671 1 a18671 1 For example, the Linux kernel maps a ‘syscall DSO’ into each d18675 2 a18676 2 header. For this command to work, you must have used ‘symbol-file’ or ‘exec-file’ commands in advance. d18678 2 a18679 2 ‘section SECTION ADDR’ The ‘section’ command changes the base address of the named SECTION d18681 1 a18681 1 not contain section addresses, (such as in the ‘a.out’ format), or d18683 1 a18683 1 section must be changed separately. The ‘info files’ command, d18686 3 a18688 3 ‘info files’ ‘info target’ ‘info files’ and ‘info target’ are synonymous; both print the d18692 1 a18692 1 command ‘help target’ lists all possible targets rather than d18695 1 a18695 1 ‘maint info sections [-all-objects] [FILTER-LIST]’ d18697 2 a18698 2 sections is ‘maint info sections’. In addition to the section information displayed by ‘info files’, this command displays the d18702 1 a18702 1 When ‘-all-objects’ is passed then sections from all loaded object d18709 1 a18709 1 ‘SECTION-NAME’ d18711 1 a18711 1 ‘SECTION-FLAG’ d18714 1 a18714 1 ‘ALLOC’ d18718 1 a18718 1 ‘LOAD’ d18721 2 a18722 2 clear for ‘.bss’ sections. ‘RELOC’ d18724 1 a18724 1 ‘READONLY’ d18726 1 a18726 1 ‘CODE’ d18728 1 a18728 1 ‘DATA’ d18730 1 a18730 1 ‘ROM’ d18732 1 a18732 1 ‘CONSTRUCTOR’ d18734 1 a18734 1 ‘HAS_CONTENTS’ d18736 1 a18736 1 ‘NEVER_LOAD’ d18738 1 a18738 1 ‘COFF_SHARED_LIBRARY’ d18741 1 a18741 1 ‘IS_COMMON’ d18744 1 a18744 1 ‘maint info target-sections’ d18750 1 a18750 1 ‘set trust-readonly-sections on’ d18760 1 a18760 1 ‘set trust-readonly-sections off’ d18765 1 a18765 1 ‘show trust-readonly-sections’ d18780 2 a18781 2 you use the ‘run’ command, or when you examine a core file. (Before you issue the ‘run’ command, GDB does not understand references to a d18792 2 a18793 2 ‘set auto-solib-add MODE’ If MODE is ‘on’, symbols from all shared object libraries will be d18796 3 a18798 3 informs GDB that a new library has been loaded. If MODE is ‘off’, symbols must be loaded manually, using the ‘sharedlibrary’ command. The default value is ‘on’. d18803 1 a18803 1 from shared libraries. To that end, type ‘set auto-solib-add off’ d18805 1 a18805 1 symbols you do need with ‘sharedlibrary REGEXP’, where REGEXP is a d18809 1 a18809 1 ‘show auto-solib-add’ d18812 1 a18812 1 To explicitly load shared library symbols, use the ‘sharedlibrary’ d18815 2 a18816 2 ‘info share REGEX’ ‘info sharedlibrary REGEX’ d18821 2 a18822 2 ‘info dll REGEX’ This is an alias of ‘info sharedlibrary’. d18824 2 a18825 2 ‘sharedlibrary REGEX’ ‘share REGEX’ d18829 1 a18829 1 after typing ‘run’. If REGEX is omitted all shared libraries d18832 1 a18832 1 ‘nosharedlibrary’ d18840 1 a18840 1 ‘catch load’ and ‘catch unload’ (*note Set Catchpoints::). d18842 1 a18842 1 GDB also supports the ‘set stop-on-solib-events’ command for this. d18847 1 a18847 1 ‘set stop-on-solib-events’ d18853 1 a18853 1 ‘show stop-on-solib-events’ d18871 1 a18871 1 ‘set sysroot PATH’ d18878 2 a18879 2 to GDB as absolute by the operating system. If you use ‘set sysroot’ to find executables and shared libraries, they need to be d18881 1 a18881 1 ‘/bin’, ‘/lib’ and ‘/usr/lib’ hierarchy under PATH. d18883 1 a18883 1 If PATH starts with the sequence ‘target:’ and the target system is d18886 1 a18886 1 supports the ‘remote get’ command (*note Sending files to a remote d18888 3 a18890 3 ‘target:’ (if present) is used as system root prefix on the remote file system. If PATH starts with the sequence ‘remote:’ this is converted to the sequence ‘target:’ by ‘set sysroot’(1). If you d18892 2 a18893 2 to be named ‘target:’ or ‘remote:’, you need to use some equivalent variant of the name like ‘./target:’. d18901 1 a18901 1 c:\foo\bar.dll ⇒ c:/foo/bar.dll d18906 1 a18906 1 c:/foo/bar.dll ⇒ /path/to/sysroot/c:/foo/bar.dll d18908 1 a18908 1 If that does not find the binary, GDB tries removing the ‘:’ d18912 1 a18912 1 c:/foo/bar.dll ⇒ /path/to/sysroot/c/foo/bar.dll d18916 2 a18917 2 copies of the target system shared libraries like so (note ‘c’ vs ‘z’): d18923 3 a18925 3 and point the system root at ‘/path/to/sysroot’, so that GDB can find the correct copies of both ‘c:\sys\bin\foo.dll’, and ‘z:\sys\bin\bar.dll’. d18930 1 a18930 1 c:/foo/bar.dll ⇒ /path/to/sysroot/foo/bar.dll d18935 2 a18936 2 The ‘set solib-absolute-prefix’ command is an alias for ‘set sysroot’. d18939 2 a18940 2 ‘--with-sysroot’ option. If the system root is inside GDB's configured binary prefix (set with ‘--prefix’ or ‘--exec-prefix’), d18944 1 a18944 1 ‘show sysroot’ d18947 1 a18947 1 ‘set solib-search-path PATH’ d18949 2 a18950 2 directories to search for shared libraries. ‘solib-search-path’ is used after ‘sysroot’ fails to locate the library, or if the path to d18952 1 a18952 1 ‘solib-search-path’ instead of ‘sysroot’, be sure to set ‘sysroot’ d18954 1 a18954 1 libraries. ‘sysroot’ is preferred; setting it to a nonexistent d18958 1 a18958 1 ‘show solib-search-path’ d18961 1 a18961 1 ‘set target-file-system-kind KIND’ d18969 2 a18970 2 ‘c:\Windows\kernel32.dll’. On Unix hosts, there's no concept of drive letters, so the ‘c:\’ prefix is not normally understood as d18976 3 a18978 3 target's shared libraries on the host using ‘set sysroot’, and impractical with ‘set solib-search-path’. Setting ‘target-file-system-kind’ to ‘dos-based’ tells GDB to interpret d18981 1 a18981 1 value of KIND can be ‘"auto"’, in addition to one of the supported d18987 1 a18987 1 ‘unix’ d18989 1 a18989 1 Only file names starting the forward slash (‘/’) character are d18993 1 a18993 1 ‘dos-based’ d18996 2 a18997 2 letter followed by a colon (e.g., ‘c:’), are considered absolute, and both the slash (‘/’) and the backslash (‘\\’) d19000 1 a19000 1 ‘auto’ d19007 1 a19007 1 Normally, GDB compares just the “base names” of the files as strings, d19015 1 a19015 1 symlinks etc., you can set ‘basenames-may-differ’ to ‘true’ to instruct d19020 1 a19020 1 ‘set basenames-may-differ’ d19023 1 a19023 1 ‘show basenames-may-differ’ d19029 1 a19029 1 remote system was provided by prefixing PATH with ‘remote:’ d19038 1 a19038 1 ‘bfd’ objects used to track open files. *Note BFD: (bfd)Top. The d19041 2 a19042 2 ‘maint info bfds’ This prints information about each ‘bfd’ object that is known to d19045 4 a19048 4 ‘maint set bfd-sharing’ ‘maint show bfd-sharing’ Control whether ‘bfd’ objects can be shared. When sharing is enabled GDB reuses already open ‘bfd’ objects rather than reopening d19050 4 a19053 4 ‘bfd’ objects to be unshared, but all future files that are opened will create a new ‘bfd’ object. Similarly, re-enabling sharing does not cause multiple existing ‘bfd’ objects to be collapsed into a single shared ‘bfd’ object. d19055 1 a19055 1 ‘set debug bfd-cache LEVEL’ d19058 1 a19058 1 ‘show debug bfd-cache’ d19077 1 a19077 1 • The executable contains a “debug link” that specifies the name of d19079 1 a19079 1 usually ‘EXECUTABLE.debug’, where EXECUTABLE is the name of the d19081 2 a19082 2 ‘ls.debug’ for ‘/usr/bin/ls’). In addition, the debug link specifies a 32-bit “Cyclic Redundancy Check” (CRC) checksum for the d19086 1 a19086 1 • The executable contains a “build ID”, a unique bit string that is d19090 1 a19090 1 details about this feature, see the description of the ‘--build-id’ d19098 1 a19098 1 • For the "debug link" method, GDB looks up the named file in the d19100 1 a19100 1 directory named ‘.debug’, and finally under each one of the global d19105 1 a19105 1 ‘d:/usr/bin/’ is converted to ‘/d/usr/bin/’, because Windows d19108 1 a19108 1 • For the "build ID" method, GDB looks in the ‘.build-id’ d19110 1 a19110 1 named ‘NN/NNNNNNNN.debug’, where NN are the first 2 hex characters d19113 1 a19113 1 10.) GDB can automatically query ‘debuginfod’ servers using build d19117 4 a19120 4 So, for example, suppose you ask GDB to debug ‘/usr/bin/ls’, which has a debug link that specifies the file ‘ls.debug’, and a build ID whose value in hex is ‘abcdef1234’. If the list of the global debug directories includes ‘/usr/lib/debug’, then GDB will look for the d19123 4 a19126 4 − ‘/usr/lib/debug/.build-id/ab/cdef1234.debug’ − ‘/usr/bin/ls.debug’ − ‘/usr/bin/.debug/ls.debug’ − ‘/usr/lib/debug/usr/bin/ls.debug’. d19128 1 a19128 1 If the debug file still has not been found and ‘debuginfod’ (*note d19130 1 a19130 1 ‘debuginfod’ servers. d19133 1 a19133 1 configure option ‘--with-separate-debug-dir’ and augmented by the d19135 1 a19135 1 ‘--additional-debug-dirs’. During GDB run you can also set the global d19138 1 a19138 1 ‘set debug-file-directory DIRECTORIES’ d19143 1 a19143 1 ‘show debug-file-directory’ d19148 1 a19148 1 ‘.gnu_debuglink’. The section must contain: d19150 1 a19150 1 • A filename, with any leading directory components removed, followed d19152 1 a19152 1 • zero to three bytes of padding, as needed to reach the next d19154 1 a19154 1 • a four-byte CRC checksum, stored in the same endianness used for d19160 1 a19160 1 contain a section named ‘.gnu_debuglink’ with the contents described d19165 1 a19165 1 named ‘.note.gnu.build-id’, but that name is not mandatory. It contains d19177 1 a19177 1 but they need not contain any data--much like a ‘.bss’ section in an d19180 1 a19180 1 The GNU binary utilities (Binutils) package includes the ‘objcopy’ d19188 1 a19188 1 ‘foo’ and place it in the file ‘foo.debug’. You can use the first, d19191 2 a19192 2 • The debug link method needs the following additional command to also leave behind a debug link in ‘foo’: d19196 4 a19199 4 Ulrich Drepper's ‘elfutils’ package, starting with version 0.53, contains a version of the ‘strip’ command such that the command ‘strip foo -f foo.debug’ has the same functionality as the two ‘objcopy’ commands and the ‘ln -s’ command above, together. d19201 2 a19202 2 • Build ID gets embedded into the main executable using ‘ld --build-id’ or the GCC counterpart ‘gcc -Wl,--build-id’. Build ID d19207 2 a19208 1 The CRC used in ‘.gnu_debuglink’ is the CRC-32 defined in IEEE 802.3 d19215 1 a19215 1 bit of each byte first. The initial pattern ‘0xffffffff’ is used, to d19220 1 a19220 1 “Remote Serial Protocol” ‘qCRC’ packet (*note qCRC packet::). However d19226 2 a19227 2 which produces the CRC used in ‘.gnu_debuglink’. Inverting the initially supplied ‘crc’ argument means that an initial call to this d19229 1 a19229 1 ‘0xffffffff’. d19307 2 a19308 2 special ‘.gnu_debugdata’ section. This feature is called “MiniDebugInfo”. This section holds an LZMA-compressed object and is d19322 1 a19322 1 This section can be easily created using ‘objcopy’ and other standard d19369 1 a19369 1 For convenience, GDB comes with a program, ‘gdb-add-index’, which can d19378 1 a19378 1 ‘gdb-add-index’ does behind the curtains. d19382 1 a19382 1 ‘objcopy’. d19384 1 a19384 1 To create an index file, use the ‘save gdb-index’ command: d19386 1 a19386 1 ‘save gdb-index [-dwarf-5] DIRECTORY’ d19389 3 a19391 3 produces a single file ‘SYMBOL-FILE.gdb-index’. If you invoke this command with the ‘-dwarf-5’ option, it produces 2 files: ‘SYMBOL-FILE.debug_names’ and ‘SYMBOL-FILE.debug_str’. The files d19395 1 a19395 1 file, here named ‘symfile’, using ‘objcopy’: d19400 1 a19400 1 Or for ‘-dwarf-5’: d19408 1 a19408 1 GDB will normally ignore older versions of ‘.gdb_index’ sections that d19411 2 a19412 2 deprecated index section anyway specify ‘set use-deprecated-index-sections on’. The default is ‘off’. This can d19416 1 a19416 1 _Warning:_ Setting ‘use-deprecated-index-sections’ to ‘on’ must be d19432 2 a19433 2 the future. This feature can be turned on with ‘set index-cache enabled on’. The following commands can be used to tweak the behavior of the d19436 2 a19437 2 ‘set index-cache enabled on’ ‘set index-cache enabled off’ d19440 2 a19441 2 ‘set index-cache directory DIRECTORY’ ‘show index-cache directory’ d19445 3 a19447 3 On most systems, the index is cached in the ‘gdb’ subdirectory of the directory pointed to by the ‘XDG_CACHE_HOME’ environment variable, if it is defined, else in the ‘.cache/gdb’ subdirectory d19455 1 a19455 1 ‘show index-cache stats’ d19461 1 a19461 1 18.6 Extensions to ‘.debug_names’ d19465 1 a19465 1 ‘.debug_names’. GDB can both read and create this section. However, in d19468 2 a19469 2 GDB uses the augmentation string ‘GDB2’. Earlier versions used the string ‘GDB’, but these versions of the index are no longer supported. d19475 7 a19481 7 ‘DW_IDX_GNU_internal’ This has the value ‘0x2000’. It is a flag that, when set, indicates that the associated entry has ‘static’ linkage. ‘DW_IDX_GNU_main’ This has the value ‘0x2002’. It is a flag that, when set, indicates that the associated entry is the program's ‘main’. d19483 2 a19484 2 ‘DW_IDX_GNU_language’ This has the value ‘0x2003’. It is ‘DW_LANG_’ constant, indicating d19487 2 a19488 2 ‘DW_IDX_GNU_linkage_name’ This has the value ‘0x2004’. It is a flag that, when set, d19506 1 a19506 1 many times the problems occur, with the ‘set complaints’ command (*note d19511 1 a19511 1 ‘inner block not inside outer block in SYMBOL’ d19520 1 a19520 1 SYMBOL may be shown as "‘(don't know)’" if the outer block is not a d19523 1 a19523 1 ‘block at ADDRESS out of order’ d19531 2 a19532 2 often determine what source file is affected by specifying ‘set verbose on’. *Note Optional Warnings and Messages: d19535 1 a19535 1 ‘bad block start address patched’ d19544 1 a19544 1 ‘bad string table offset in symbol N’ d19550 1 a19550 1 name ‘foo’, which may cause other problems if many symbols end up d19553 1 a19553 1 ‘unknown symbol type 0xNN’ d19556 1 a19556 1 yet know how to read. ‘0xNN’ is the symbol type of the d19562 3 a19564 3 feel like debugging it, you can debug ‘gdb’ with itself, breakpoint on ‘complain’, then go up to the function ‘read_dbx_symtab’ and examine ‘*bufp’ to see the symbol. d19566 1 a19566 1 ‘stub type has NULL name’ d19570 1 a19570 1 ‘const/volatile indicator missing (ok if using g++ v1.x), got...’ d19575 1 a19575 1 ‘info mismatch between compiler and debugger’ d19586 1 a19586 1 a directory known as the “data directory”. d19591 1 a19591 1 ‘set data-directory DIRECTORY’ d19595 1 a19595 1 ‘show data-directory’ d19599 2 a19600 2 ‘--with-gdb-datadir’ option. If the data directory is inside GDB's configured binary prefix (set with ‘--prefix’ or ‘--exec-prefix’), then d19604 1 a19604 1 The data directory may also be specified with the ‘--data-directory’ d19613 1 a19613 1 A “target” is the execution environment occupied by your program. d19617 1 a19617 1 the ‘file’ or ‘core’ commands. When you need more flexibility--for d19620 1 a19620 1 connection--you can use the ‘target’ command to specify one of the d19624 3 a19626 3 It is possible to build GDB for several different “target architectures”. When GDB is built like that, you can choose one of the available architectures with the ‘set architecture’ command. d19628 1 a19628 1 ‘set architecture ARCH’ d19630 1 a19630 1 value of ARCH can be ‘"auto"’, in addition to one of the supported d19633 1 a19633 1 ‘show architecture’ d19636 4 a19639 4 ‘set processor’ ‘processor’ These are alias commands for, respectively, ‘set architecture’ and ‘show architecture’. d19660 1 a19660 1 and ‘reverse-step’ there, you are presented a virtual layer of the d19664 1 a19664 1 Use the ‘core-file’ and ‘exec-file’ commands to select a new core d19666 1 a19666 1 specify as a target a process that is already running, use the ‘attach’ d19675 1 a19675 1 ‘target TYPE PARAMETERS’ d19685 1 a19685 1 The ‘target’ command does not repeat if you press again after d19688 1 a19688 1 ‘help target’ d19690 1 a19690 1 currently selected, use either ‘info target’ or ‘info files’ (*note d19693 1 a19693 1 ‘help target NAME’ d19697 1 a19697 1 ‘set gnutarget ARGS’ d19699 3 a19701 3 it is reading an “executable”, a “core”, or a “.o” file; however, you can specify the file format with the ‘set gnutarget’ command. Unlike most ‘target’ commands, with ‘gnutarget’ the ‘target’ refers d19704 1 a19704 1 _Warning:_ To specify a file format with ‘set gnutarget’, you d19709 3 a19711 3 ‘show gnutarget’ Use the ‘show gnutarget’ command to display what file format ‘gnutarget’ is set to read. If you have not set ‘gnutarget’, GDB d19713 1 a19713 1 ‘show gnutarget’ displays ‘The current BFD target is "auto"’. d19718 7 a19724 7 ‘target exec PROGRAM’ An executable file. ‘target exec PROGRAM’ is the same as ‘exec-file PROGRAM’. ‘target core FILENAME’ A core dump file. ‘target core FILENAME’ is the same as ‘core-file FILENAME’. d19726 1 a19726 1 ‘target remote MEDIUM’ d19731 1 a19731 1 For example, if you have a board connected to ‘/dev/ttya’ on the d19736 1 a19736 1 ‘target remote’ supports the ‘load’ command. This is only useful d19741 1 a19741 1 ‘target sim [SIMARGS] ...’ d19753 4 a19756 4 ‘target native’ Setup for local/native process debugging. Useful to make the ‘run’ command spawn native processes (likewise ‘attach’, etc.) even when ‘set auto-connect-native-target’ is ‘off’ (*note set d19766 2 a19767 2 ‘set hash’ This command controls whether a hash mark ‘#’ is displayed while d19772 1 a19772 1 ‘show hash’ d19775 1 a19775 1 ‘set debug monitor’ d19779 1 a19779 1 ‘show debug monitor’ d19783 1 a19783 1 ‘load FILENAME OFFSET’ d19785 1 a19785 1 GDB, the ‘load’ command may be available. Where it exists, it is d19788 2 a19789 2 ‘load’ also records the FILENAME symbol table in GDB, like the ‘add-symbol-file’ command. d19791 3 a19793 3 If your GDB does not have a ‘load’ command, attempting to execute it gets the error message "‘You can't do that when your target is ...’" d19807 1 a19807 1 ‘load’ does not repeat if you press again after using it. d19809 1 a19809 1 ‘flash-erase’ d19826 1 a19826 1 ‘set endian big’ d19829 1 a19829 1 ‘set endian little’ d19832 1 a19832 1 ‘set endian auto’ d19835 1 a19835 1 ‘show endian’ d19838 1 a19838 1 If the ‘set endian auto’ mode is in effect and no executable has been d19840 1 a19840 1 of the ‘set endian big’ and ‘set endian little’ commands or by inferring d19843 2 a19844 2 has been built for, and is ‘little’ if the name of the target CPU has an ‘el’ suffix and ‘big’ otherwise. d19870 1 a19870 1 use ‘help target’ to list them. d19894 3 a19896 3 GDB supports two types of remote connections, ‘target remote’ mode and ‘target extended-remote’ mode. Note that many remote targets support only ‘target remote’ mode. There are several major differences between d19902 1 a19902 1 ‘gdbserver’, ‘gdbserver’ will exit. d19907 1 a19907 1 a running program, or use ‘monitor’ commands specific to the d19910 3 a19912 3 When using ‘gdbserver’ in this case, it does not exit unless it was invoked using the ‘--once’ option. If the ‘--once’ option was not used, you can ask ‘gdbserver’ to exit using the ‘monitor exit’ d19916 2 a19917 2 For both connection types you use the ‘file’ command to specify the program on the host system. If you are using ‘gdbserver’ there are d19922 1 a19922 1 debug on the ‘gdbserver’ command line or use the ‘--attach’ option d19926 2 a19927 2 debug on the ‘gdbserver’ command line, or you can load the program or attach to it using GDB commands after connecting to ‘gdbserver’. d19929 3 a19931 3 You can start ‘gdbserver’ without supplying an initial command to run or process ID to attach. To do this, use the ‘--multi’ command line option. Then you can connect using ‘target extended-remote’ d19933 4 a19936 4 using the ‘run’ command in this scenario). Note that the conditions under which ‘gdbserver’ terminates depend on how GDB connects to it (‘target remote’ or ‘target extended-remote’). The ‘--multi’ option to ‘gdbserver’ has no influence on that. d19938 2 a19939 2 The ‘run’ command *With target remote mode:* The ‘run’ command is not supported. d19942 2 a19943 2 already running, so you can use commands like ‘step’ and ‘continue’. d19945 2 a19946 2 *With target extended-remote mode:* The ‘run’ command is supported. The ‘run’ command uses the value set by ‘set remote exec-file’ d19952 3 a19954 3 ‘run’ command is not required to start execution, and you can resume using commands like ‘step’ and ‘continue’ as with ‘target remote’ mode. d19957 3 a19959 3 *With target remote mode:* The GDB command ‘attach’ is not supported. To attach to a running program using ‘gdbserver’, you must use the ‘--attach’ option (*note Running gdbserver::). d19962 3 a19964 3 you may use the ‘attach’ command after the connection has been established. If you are using ‘gdbserver’, you may also invoke ‘gdbserver’ using the ‘--attach’ option (*note Running d19969 1 a19969 1 case, GDB uses the value of ‘exec-file-mismatch’ to handle a d19981 1 a19981 1 ‘target remote’ mode and ‘target extended-remote’ mode. d19986 2 a19987 2 the remote program is unstripped, the only command you need is ‘target remote’ (or ‘target extended-remote’). d19991 2 a19992 2 unstripped copy of your program as the first argument, or use the ‘file’ command. Use ‘set sysroot’ to specify the location (on the host) of d19994 2 a19995 2 using ‘--with-sysroot’). Alternatively, you may use ‘set solib-search-path’ to specify how GDB locates target libraries. d20002 1 a20002 1 also prevent ‘gdbserver’ from debugging multi-threaded programs. d20010 2 a20011 2 carrying the debugging packets varies. The ‘target remote’ and ‘target extended-remote’ commands establish a connection to the target. Both d20014 2 a20015 2 ‘target remote SERIAL-DEVICE’ ‘target extended-remote SERIAL-DEVICE’ d20017 1 a20017 1 use a serial line connected to the device named ‘/dev/ttyb’: d20022 2 a20023 2 ‘--baud’ option, or use the ‘set serial baud’ command (*note set serial baud: Remote Configuration.) before the ‘target’ command. d20025 2 a20026 2 ‘target remote LOCAL-SOCKET’ ‘target extended-remote LOCAL-SOCKET’ d20029 1 a20029 1 ‘/tmp/gdb-socket0’: d20039 14 a20052 14 ‘target remote HOST:PORT’ ‘target remote [HOST]:PORT’ ‘target remote tcp:HOST:PORT’ ‘target remote tcp:[HOST]:PORT’ ‘target remote tcp4:HOST:PORT’ ‘target remote tcp6:HOST:PORT’ ‘target remote tcp6:[HOST]:PORT’ ‘target extended-remote HOST:PORT’ ‘target extended-remote [HOST]:PORT’ ‘target extended-remote tcp:HOST:PORT’ ‘target extended-remote tcp:[HOST]:PORT’ ‘target extended-remote tcp4:HOST:PORT’ ‘target extended-remote tcp6:HOST:PORT’ ‘target extended-remote tcp6:[HOST]:PORT’ d20062 1 a20062 1 ‘manyfarms’: d20067 1 a20067 1 ‘2001:0db8:85a3:0000:0000:8a2e:0370:7334’, you can either use the d20092 10 a20101 10 ‘target remote udp:HOST:PORT’ ‘target remote udp:[HOST]:PORT’ ‘target remote udp4:HOST:PORT’ ‘target remote udp6:[HOST]:PORT’ ‘target extended-remote udp:HOST:PORT’ ‘target extended-remote udp:HOST:PORT’ ‘target extended-remote udp:[HOST]:PORT’ ‘target extended-remote udp4:HOST:PORT’ ‘target extended-remote udp6:HOST:PORT’ ‘target extended-remote udp6:[HOST]:PORT’ d20103 1 a20103 1 to UDP port 2828 on a terminal server named ‘manyfarms’: d20112 2 a20113 2 ‘target remote | COMMAND’ ‘target extended-remote | COMMAND’ d20116 1 a20116 1 system's command shell, ‘/bin/sh’; it should expect remote protocol d20120 1 a20120 1 programs like ‘ssh’, or for other similar tricks. d20123 1 a20123 1 will try to send it a ‘SIGTERM’ signal. (If the program has d20127 1 a20127 1 interrupt character (often ‘Ctrl-c’), GDB attempts to stop the program. d20135 1 a20135 1 In ‘target remote’ mode, if you type ‘y’, GDB abandons the remote d20137 1 a20137 1 use ‘target remote’ again to connect once more.) If you type ‘n’, GDB d20140 1 a20140 1 In ‘target extended-remote’ mode, typing ‘n’ will leave GDB connected d20143 1 a20143 1 ‘detach’ d20145 1 a20145 1 the ‘detach’ command to release it from GDB control. Detaching d20147 3 a20149 3 will depend on your particular remote stub. After the ‘detach’ command in ‘target remote’ mode, GDB is free to connect to another target. In ‘target extended-remote’ mode, GDB is still connected d20152 2 a20153 2 ‘disconnect’ The ‘disconnect’ command closes the connection to the target, and d20156 1 a20156 1 the ‘disconnect’ command, GDB is again free to connect to another d20159 1 a20159 1 ‘monitor CMD’ d20175 1 a20175 1 ‘gdbserver’ over a network interface. For other targets, e.g. embedded d20181 1 a20181 1 ‘remote put HOSTFILE TARGETFILE’ d20185 1 a20185 1 ‘remote get TARGETFILE HOSTFILE’ d20189 1 a20189 1 ‘remote delete TARGETFILE’ d20195 1 a20195 1 20.3 Using the ‘gdbserver’ Program d20198 3 a20200 3 ‘gdbserver’ is a control program for Unix-like systems, which allows you to connect your program with a remote GDB via ‘target remote’ or ‘target extended-remote’--but without linking in the usual debugging stub. d20202 1 a20202 1 ‘gdbserver’ is not a complete replacement for the debugging stubs, d20204 2 a20205 2 that GDB itself does. In fact, a system that can run ‘gdbserver’ to connect to a remote GDB could also run GDB locally! ‘gdbserver’ is d20208 1 a20208 1 able to get started more quickly on a new system by using ‘gdbserver’. d20212 1 a20212 1 by cross-compiling. You can use ‘gdbserver’ to make a similar choice d20215 1 a20215 1 GDB and ‘gdbserver’ communicate via either a serial line or a TCP d20218 4 a20221 4 _Warning:_ ‘gdbserver’ does not have any built-in security. Do not run ‘gdbserver’ connected to any public network; a GDB connection to ‘gdbserver’ provides access to the target system with the same privileges as the user running ‘gdbserver’. d20223 1 a20223 1 20.3.1 Running ‘gdbserver’ d20226 2 a20227 2 Run ‘gdbserver’ on the target system. You need a copy of the program you want to debug, including any libraries it requires. ‘gdbserver’ d20239 3 a20241 3 hostname and portnumber, or ‘-’ or ‘stdio’ to use stdin/stdout of ‘gdbserver’. For example, to debug Emacs with the argument ‘foo.txt’ and communicate with GDB over the serial port ‘/dev/com1’: d20245 1 a20245 1 ‘gdbserver’ waits passively for the host GDB to communicate with it. d20253 3 a20255 3 ‘host:2345’ argument means that ‘gdbserver’ is to expect a TCP connection from machine ‘host’ to local TCP port 2345. (Currently, the ‘host’ part is ignored.) You can choose any number you want for the d20257 3 a20259 3 in use on the target system (for example, ‘23’ is reserved for ‘telnet’).(1) You must use the same port number with the host GDB ‘target remote’ command. d20261 1 a20261 1 The ‘stdio’ connection is useful when starting ‘gdbserver’ with ssh: d20265 1 a20265 1 The ‘-T’ option to ssh is provided because we don't need a remote d20270 3 a20272 3 Programs started with stdio-connected gdbserver have ‘/dev/null’ for ‘stdin’, and ‘stdout’,‘stderr’ are sent back to gdb for display through a pipe connected to gdbserver. Both ‘stdout’ and ‘stderr’ use the same d20278 2 a20279 2 On some targets, ‘gdbserver’ can also attach to running programs. This is accomplished via the ‘--attach’ argument. The syntax is: d20284 1 a20284 1 necessary to point ‘gdbserver’ at a binary for the running process. d20286 1 a20286 1 In ‘target extended-remote’ mode, you can also attach using the GDB d20290 1 a20290 1 has the ‘pidof’ utility: d20295 1 a20295 1 multiple threads, most versions of ‘pidof’ support the ‘-s’ option to d20298 1 a20298 1 20.3.1.2 TCP port allocation lifecycle of ‘gdbserver’ d20301 1 a20301 1 This section applies only when ‘gdbserver’ is run to listen on a TCP d20304 3 a20306 3 ‘gdbserver’ normally terminates after all of its debugged processes have terminated in ‘target remote’ mode. On the other hand, for ‘target extended-remote’, ‘gdbserver’ stays running even with no processes left. d20308 1 a20308 1 normally also terminates ‘gdbserver’ in the ‘target remote’ mode. d20310 2 a20311 2 ‘gdbserver’ to kill its debugged processes, ‘gdbserver’ stays running even in the ‘target remote’ mode. d20313 1 a20313 1 When ‘gdbserver’ stays running, GDB can connect to it again later. d20318 3 a20320 3 By default, ‘gdbserver’ keeps the listening TCP port open, so that subsequent connections are possible. However, if you start ‘gdbserver’ with the ‘--once’ option, it will stop listening for any further d20322 2 a20323 2 means no further connections to ‘gdbserver’ will be possible after the first one. It also means ‘gdbserver’ will terminate after the first d20325 1 a20325 1 connections and even in the ‘target extended-remote’ mode. The ‘--once’ d20327 1 a20327 1 instances of ‘gdbserver’ running on the same host, since each instance d20330 1 a20330 1 20.3.1.3 Other Command-Line Arguments for ‘gdbserver’ d20333 1 a20333 1 You can use the ‘--multi’ option to start ‘gdbserver’ without specifying d20335 1 a20335 1 ‘target extended-remote’ mode and run or attach to a program. For more d20338 1 a20338 1 The ‘--debug[=option1,option2,...]’ option tells ‘gdbserver’ to d20340 1 a20340 1 options (OPTION1, OPTION2, etc) control for which areas of ‘gdbserver’ d20343 1 a20343 1 ‘all’ d20345 1 a20345 1 ‘threads’ d20348 2 a20349 2 this could change in future releases of ‘gdbserver’. ‘event-loop’ d20351 1 a20351 1 ‘remote’ d20355 4 a20358 4 If no options are passed to ‘--debug’ then this is treated as equivalent to ‘--debug=threads’. This could change in future releases of ‘gdbserver’. The options passed to ‘--debug’ are processed left to right, and individual options can be prefixed with the ‘-’ (minus) d20366 1 a20366 1 The ‘--debug-file=FILENAME’ option tells ‘gdbserver’ to write any d20368 1 a20368 1 ‘gdbserver’ development and for bug reports to the developers. d20370 1 a20370 1 The ‘--debug-format=option1[,option2,...]’ option tells ‘gdbserver’ d20373 1 a20373 1 ‘none’ d20375 1 a20375 1 ‘all’ d20377 1 a20377 1 ‘timestamps’ d20380 1 a20380 1 Options are processed in order. Thus, for example, if ‘none’ appears d20383 1 a20383 1 The ‘--wrapper’ option specifies a wrapper to launch programs for d20385 1 a20385 1 then any command-line arguments to pass to the wrapper, then ‘--’ d20388 1 a20388 1 ‘gdbserver’ runs the specified wrapper program with a combined d20393 1 a20393 1 You can use any program that eventually calls ‘execve’ with its d20395 1 a20395 1 ‘env’ and ‘nohup’. Any Unix shell script ending with ‘exec "$@@"’ will d20398 2 a20399 2 For example, you can use ‘env’ to pass an environment variable to the debugged program, without setting the variable in ‘gdbserver’'s d20404 1 a20404 1 The ‘--selftest’ option runs the self tests in ‘gdbserver’: d20411 1 a20411 1 20.3.2 Connecting to ‘gdbserver’ d20416 1 a20416 1 • Run GDB on the host system. d20418 1 a20418 1 • Make sure you have the necessary symbol files (*note Host and d20420 1 a20420 1 ‘file’ command before you connect. Use ‘set sysroot’ to locate d20422 1 a20422 1 sysroot using ‘--with-sysroot’). d20424 3 a20426 3 • Connect to your target (*note Connecting to a Remote Target: Connecting.). For TCP connections, you must start up ‘gdbserver’ prior to using the ‘target’ command. Otherwise you may get an d20428 2 a20429 2 looks something like ‘Connection refused’. Don't use the ‘load’ command in GDB when using ‘target remote’ mode, since the program d20432 1 a20432 1 20.3.3 Monitor Commands for ‘gdbserver’ d20435 2 a20436 2 During a GDB session using ‘gdbserver’, you can use the ‘monitor’ command to send special requests to ‘gdbserver’. Here are the available d20439 1 a20439 1 ‘monitor help’ d20442 1 a20442 1 ‘monitor set debug off’ d20445 1 a20445 1 ‘monitor set debug on’ d20447 1 a20447 1 is equivalent to ‘monitor set debug threads on’, but this might d20450 2 a20451 2 ‘monitor set debug threads off’ ‘monitor set debug threads on’ d20457 2 a20458 2 ‘monitor set debug remote off’ ‘monitor set debug remote on’ d20462 2 a20463 2 ‘monitor set debug event-loop off’ ‘monitor set debug event-loop on’ d20467 2 a20468 2 ‘monitor set debug-file filename’ ‘monitor set debug-file’ d20471 1 a20471 1 ‘monitor set debug-format option1[,option2,...]’ d20475 1 a20475 1 ‘none’ d20477 1 a20477 1 ‘all’ d20479 1 a20479 1 ‘timestamps’ d20482 1 a20482 1 Options are processed in order. Thus, for example, if ‘none’ d20486 1 a20486 1 ‘monitor set libthread-db-search-path [PATH]’ d20488 1 a20488 1 directories to search for ‘libthread_db’ (*note set d20490 1 a20490 1 ‘libthread-db-search-path’ will be reset to its default value. d20492 2 a20493 2 The special entry ‘$pdir’ for ‘libthread-db-search-path’ is not supported in ‘gdbserver’. d20495 1 a20495 1 ‘monitor exit’ d20497 3 a20499 3 followed by ‘disconnect’ to close the debugging session. ‘gdbserver’ will detach from any attached processes and kill any processes it created. Use ‘monitor exit’ to terminate ‘gdbserver’ d20502 1 a20502 1 20.3.4 Tracepoints support in ‘gdbserver’ d20505 1 a20505 1 On some targets, ‘gdbserver’ supports tracepoints, fast tracepoints and d20509 2 a20510 2 “in-process agent” (IPA), must be loaded in the inferior process. This library is built and distributed as an integral part of ‘gdbserver’. In d20516 3 a20518 3 ‘gdbserver’ is built, or if ‘gdbserver’ was explicitly configured using ‘--with-ust’ to point at such headers. You can explicitly disable the support using ‘--with-ust=no’. d20522 1 a20522 1 ‘Specifying it as dependency at link time’ d20526 1 a20526 1 ‘-linproctrace’ to the link command. d20528 1 a20528 1 ‘Using the system's preloading mechanisms’ d20533 3 a20535 3 cases, you do that by specifying ‘LD_PRELOAD=libinproctrace.so’ in the environment. See also the description of ‘gdbserver’'s ‘--wrapper’ command line option. d20537 1 a20537 1 ‘Using GDB to force loading the agent at run time’ d20542 2 a20543 2 On most Unix systems, the function is ‘dlopen’. You'll use the ‘call’ command for that. For example: d20547 2 a20548 2 Note that on most Unix systems, for the ‘dlopen’ function to be available, the program needs to be linked with ‘-ldl’. d20551 1 a20551 1 systems, when you connect to ‘gdbserver’ using ‘target remote’, you'll d20558 1 a20558 1 C++ program, start ‘gdbserver’ like so: d20562 1 a20562 1 Start GDB and connect to ‘gdbserver’ like so, and run to main: d20571 2 a20572 2 process; you can confirm it with the ‘info sharedlibrary’ command, which will list ‘libinproctrace.so’ as loaded in the process. You are now d20579 1 a20579 1 ‘gdbserver’ prints an error message and exits. d20592 1 a20592 1 ‘set remoteaddresssize BITS’ d20598 1 a20598 1 ‘show remoteaddresssize’ d20601 1 a20601 1 ‘set serial baud N’ d20606 1 a20606 1 ‘show serial baud’ d20609 1 a20609 1 ‘set serial parity PARITY’ d20611 1 a20611 1 PARITY are: ‘even’, ‘none’, and ‘odd’. The default is ‘none’. d20613 1 a20613 1 ‘show serial parity’ d20616 5 a20620 5 ‘set remotebreak’ If set to on, GDB sends a ‘BREAK’ signal to the remote when you type ‘Ctrl-c’ to interrupt the program running on the remote. If set to off, GDB sends the ‘Ctrl-C’ character instead. The default is off, since most remote systems expect to see ‘Ctrl-C’ as the d20623 2 a20624 2 ‘show remotebreak’ Show whether GDB sends ‘BREAK’ or ‘Ctrl-C’ to interrupt the remote d20627 3 a20629 3 ‘set remoteflow on’ ‘set remoteflow off’ Enable or disable hardware flow control (‘RTS’/‘CTS’) on the serial d20632 1 a20632 1 ‘show remoteflow’ d20635 1 a20635 1 ‘set remotelogbase BASE’ d20637 2 a20638 2 communications to BASE. Supported values of BASE are: ‘ascii’, ‘octal’, and ‘hex’. The default is ‘ascii’. d20640 1 a20640 1 ‘show remotelogbase’ d20644 1 a20644 1 ‘set remotelogfile FILE’ d20648 1 a20648 1 ‘show remotelogfile’ d20652 1 a20652 1 ‘set remotetimeout NUM’ d20656 1 a20656 1 ‘show remotetimeout’ d20660 2 a20661 2 ‘set remote hardware-watchpoint-limit LIMIT’ ‘set remote hardware-breakpoint-limit LIMIT’ d20664 1 a20664 1 watchpoints or breakpoints, and ‘unlimited’ for unlimited d20667 2 a20668 2 ‘show remote hardware-watchpoint-limit’ ‘show remote hardware-breakpoint-limit’ d20672 1 a20672 1 ‘set remote hardware-watchpoint-length-limit LIMIT’ d20675 1 a20675 1 watchpoints and ‘unlimited’ allows watchpoints of any length. d20677 1 a20677 1 ‘show remote hardware-watchpoint-length-limit’ d20681 3 a20683 3 ‘set remote exec-file FILENAME’ ‘show remote exec-file’ Select the file used for ‘run’ with ‘target extended-remote’. This d20688 2 a20689 2 ‘set remote interrupt-sequence’ Allow the user to select one of ‘Ctrl-C’, a ‘BREAK’ or ‘BREAK-g’ as d20691 1 a20691 1 execution. ‘Ctrl-C’ is a default. Some system prefers ‘BREAK’ d20693 2 a20694 2 kernel prefers ‘BREAK-g’, a.k.a Magic SysRq g. It is ‘BREAK’ signal followed by character ‘g’. d20696 4 a20699 4 ‘show remote interrupt-sequence’ Show which of ‘Ctrl-C’, ‘BREAK’ or ‘BREAK-g’ is sent by GDB to interrupt the remote program. ‘BREAK-g’ is BREAK signal followed by ‘g’ and also known as Magic SysRq g. d20701 1 a20701 1 ‘set remote interrupt-on-connect’ d20704 1 a20704 1 kernel. Linux kernel expects ‘BREAK’ followed by ‘g’ which is d20707 1 a20707 1 ‘show remote interrupt-on-connect’ d20711 1 a20711 1 ‘set tcp auto-retry on’ d20718 1 a20718 1 by ‘set tcp connect-timeout’. d20720 1 a20720 1 ‘set tcp auto-retry off’ d20723 1 a20723 1 ‘show tcp auto-retry’ d20726 2 a20727 2 ‘set tcp connect-timeout SECONDS’ ‘set tcp connect-timeout unlimited’ d20730 1 a20730 1 failed connections (enabled by ‘set tcp auto-retry on’) and waiting d20732 1 a20732 1 approximate cumulative value. If SECONDS is ‘unlimited’, there is d20734 1 a20734 1 forever, unless interrupted with ‘Ctrl-c’. The default is 15 d20737 1 a20737 1 ‘show tcp connect-timeout’ d20743 3 a20745 3 be set to ‘on’ (the remote target supports this packet), ‘off’ (the remote target does not support this packet), or ‘auto’ (detect remote target support for this packet). They all default to ‘auto’. For more d20753 1 a20753 1 ‘set remote NAME-packet’. If you configure a packet, the configuration d20758 1 a20758 1 ‘show remote NAME-packet’. It displays the current remote target's d20765 1 a20765 1 ‘fetch-register’ ‘p’ ‘info registers’ d20767 1 a20767 1 ‘set-register’ ‘P’ ‘set’ d20769 1 a20769 1 ‘binary-download’ ‘X’ ‘load’, ‘set’ d20771 1 a20771 1 ‘read-aux-vector’ ‘qXfer:auxv:read’ ‘info auxv’ d20773 1 a20773 1 ‘symbol-lookup’ ‘qSymbol’ Detecting d20776 1 a20776 1 ‘attach’ ‘vAttach’ ‘attach’ d20778 1 a20778 1 ‘verbose-resume’ ‘vCont’ Stepping or d20782 1 a20782 1 ‘run’ ‘vRun’ ‘run’ d20784 1 a20784 1 ‘software-breakpoint’‘Z0’ ‘break’ d20786 1 a20786 1 ‘hardware-breakpoint’‘Z1’ ‘hbreak’ d20788 1 a20788 1 ‘write-watchpoint’ ‘Z2’ ‘watch’ d20790 1 a20790 1 ‘read-watchpoint’ ‘Z3’ ‘rwatch’ d20792 1 a20792 1 ‘access-watchpoint’ ‘Z4’ ‘awatch’ d20794 1 a20794 1 ‘pid-to-exec-file’ ‘qXfer:exec-file:read’ ‘attach’, ‘run’ d20796 2 a20797 2 ‘target-features’ ‘qXfer:features:read’ ‘set architecture’ d20799 2 a20800 2 ‘library-info’ ‘qXfer:libraries:read’ ‘info sharedlibrary’ d20802 1 a20802 1 ‘memory-map’ ‘qXfer:memory-map:read’ ‘info mem’ d20804 1 a20804 1 ‘read-sdata-object’ ‘qXfer:sdata:read’ ‘print $_sdata’ d20806 2 a20807 2 ‘read-siginfo-object’‘qXfer:siginfo:read’ ‘print $_siginfo’ d20809 1 a20809 1 ‘write-siginfo-object’‘qXfer:siginfo:write’ ‘set $_siginfo’ d20811 1 a20811 1 ‘threads’ ‘qXfer:threads:read’ ‘info threads’ d20813 2 a20814 2 ‘get-thread-local- ‘qGetTLSAddr’ Displaying storage-address’ ‘__thread’ d20817 1 a20817 1 ‘get-thread-information-block-address’‘qGetTIBAddr’Display d20823 1 a20823 1 ‘search-memory’ ‘qSearch:memory’ ‘find’ d20825 1 a20825 1 ‘supported-packets’ ‘qSupported’ Remote d20829 1 a20829 1 ‘catch-syscalls’ ‘QCatchSyscalls’ ‘catch syscall’ d20831 1 a20831 1 ‘pass-signals’ ‘QPassSignals’ ‘handle SIGNAL’ d20833 1 a20833 1 ‘program-signals’ ‘QProgramSignals’ ‘handle SIGNAL’ d20835 2 a20836 2 ‘hostio-close-packet’‘vFile:close’ ‘remote get’, ‘remote put’ d20838 2 a20839 2 ‘hostio-open-packet’ ‘vFile:open’ ‘remote get’, ‘remote put’ d20841 2 a20842 2 ‘hostio-pread-packet’‘vFile:pread’ ‘remote get’, ‘remote put’ d20844 2 a20845 2 ‘hostio-pwrite-packet’‘vFile:pwrite’ ‘remote get’, ‘remote put’ d20847 1 a20847 1 ‘hostio-unlink-packet’‘vFile:unlink’ ‘remote delete’ d20849 1 a20849 1 ‘hostio-readlink-packet’‘vFile:readlink’ Host I/O d20851 1 a20851 1 ‘hostio-fstat-packet’‘vFile:fstat’ Host I/O d20853 1 a20853 1 ‘hostio-setfs-packet’‘vFile:setfs’ Host I/O d20855 1 a20855 1 ‘noack-packet’ ‘QStartNoAckMode’ Packet d20858 1 a20858 1 ‘osdata’ ‘qXfer:osdata:read’ ‘info os’ d20860 1 a20860 1 ‘query-attached’ ‘qAttached’ Querying remote d20864 2 a20865 2 ‘trace-buffer-size’ ‘QTBuffer:size’ ‘set trace-buffer-size’ d20867 1 a20867 1 ‘trace-status’ ‘qTStatus’ ‘tstatus’ d20869 1 a20869 1 ‘traceframe-info’ ‘qXfer:traceframe-info:read’Traceframe info d20871 1 a20871 1 ‘install-in-trace’ ‘InstallInTrace’ Install d20875 2 a20876 2 ‘disable-randomization’‘QDisableRandomization’‘set disable-randomization’ d20878 2 a20879 2 ‘startup-with-shell’ ‘QStartupWithShell’ ‘set startup-with-shell’ d20881 2 a20882 2 ‘environment-hex-encoded’‘QEnvironmentHexEncoded’‘set environment’ d20884 2 a20885 2 ‘environment-unset’ ‘QEnvironmentUnset’ ‘unset environment’ d20887 1 a20887 1 ‘environment-reset’ ‘QEnvironmentReset’ ‘Reset the d20892 1 a20892 1 variables)’ d20894 1 a20894 1 ‘set-working-dir’ ‘QSetWorkingDir’ ‘set cwd’ d20896 1 a20896 1 ‘conditional-breakpoints-packet’‘Z0 and Z1’ ‘Support for d20900 1 a20900 1 evaluation’ d20902 2 a20903 2 ‘multiprocess-extensions’‘multiprocess Debug multiple extensions’ processes and d20907 1 a20907 1 ‘swbreak-feature’ ‘swbreak stop reason’ ‘break’ d20909 1 a20909 1 ‘hwbreak-feature’ ‘hwbreak stop reason’ ‘hbreak’ d20911 1 a20911 1 ‘fork-event-feature’ ‘fork stop reason’ ‘fork’ d20913 1 a20913 1 ‘vfork-event-feature’‘vfork stop reason’ ‘vfork’ d20915 1 a20915 1 ‘exec-event-feature’ ‘exec stop reason’ ‘exec’ d20917 1 a20917 1 ‘thread-events’ ‘QThreadEvents’ Tracking thread d20920 1 a20920 1 ‘thread-options’ ‘QThreadOptions’ Set thread event d20924 2 a20925 2 ‘no-resumed-stop-reply’‘no resumed thread Tracking thread left stop reply’ lifetime. d20930 2 a20931 2 ‘set remote memory-read-packet-size’ and ‘set remote memory-write-packet-size’. If set to ‘0’ (zero) the default d20933 2 a20934 2 on the target. Specify ‘fixed’ to disable the target-dependent restriction and ‘limit’ to enable it. Similar to the enabling and d20939 2 a20940 2 ‘show remote memory-read-packet-size’ and ‘show remote memory-write-packet-size’. If no remote target is d20951 1 a20951 1 source file ‘remote.c’. Normally, you can simply allow these d20954 1 a20954 1 with one of the existing stub files. ‘sparc-stub.c’ is the best d20957 1 a20957 1 To debug a program running on another machine (the debugging “target” d20962 1 a20962 1 usually have a name like ‘crt0’. The startup routine may be d20975 1 a20975 1 communicate with the machine where GDB is running (the “host” machine). d20980 1 a20980 1 else is set up, you can simply use the ‘target remote’ command d20986 1 a20986 1 these subroutines is called a “debugging stub”. d20989 2 a20990 2 ‘gdbserver’ instead of linking a stub into your program. *Note Using the ‘gdbserver’ Program: Server, for details. d20993 1 a20993 1 machine; for example, use ‘sparc-stub.c’ to debug programs on SPARC d20998 1 a20998 1 ‘i386-stub.c’ d21001 1 a21001 1 ‘m68k-stub.c’ d21004 1 a21004 1 ‘sh-stub.c’ d21007 1 a21007 1 ‘sparc-stub.c’ d21010 1 a21010 1 ‘sparcl-stub.c’ d21013 1 a21013 1 The ‘README’ file in the GDB distribution may list other recently d21031 2 a21032 2 ‘set_debug_traps’ This routine arranges for ‘handle_exception’ to run when your d21036 1 a21036 1 ‘handle_exception’ d21038 1 a21038 1 explicitly--the setup code arranges for ‘handle_exception’ to run d21041 1 a21041 1 ‘handle_exception’ takes control when your program stops during d21044 1 a21044 1 communications protocol is implemented; ‘handle_exception’ acts as d21049 1 a21049 1 that point, ‘handle_exception’ returns control to your own code on d21052 1 a21052 1 ‘breakpoint’ d21058 1 a21058 1 ‘handle_exception’--in effect, to GDB. On some machines, simply d21060 2 a21061 2 again, in that situation, you don't need to call ‘breakpoint’ from your own program--simply running ‘target remote’ from the host GDB d21064 1 a21064 1 Call ‘breakpoint’ if none of these is true, or if you simply want d21081 1 a21081 1 ‘int getDebugChar()’ d21083 1 a21083 1 port. It may be identical to ‘getchar’ for your target system; a d21087 1 a21087 1 ‘void putDebugChar(int)’ d21089 1 a21089 1 port. It may be identical to ‘putchar’ for your target system; a d21095 1 a21095 1 stop when it receives a ‘^C’ (‘\003’, the control-C character). That is d21101 1 a21101 1 GDB reports a ‘SIGTRAP’ instead of a ‘SIGINT’). d21105 1 a21105 1 ‘void exceptionHandler (int EXCEPTION_NUMBER, void *EXCEPTION_ADDRESS)’ d21125 1 a21125 1 without help from ‘exceptionHandler’. d21127 1 a21127 1 ‘void flush_i_cache()’ d21137 2 a21138 2 ‘void *memset(void *, int, int)’ This is the standard library function ‘memset’ that sets an area of d21140 1 a21140 1 ‘libc.a’, ‘memset’ can be found there; otherwise, you must either d21146 1 a21146 1 subroutines which ‘GCC’ generates as inline code. d21159 2 a21160 2 ‘getDebugChar’, ‘putDebugChar’, ‘flush_i_cache’, ‘memset’, ‘exceptionHandler’. d21171 1 a21171 1 adjust ‘handle_exception’ to arrange for it to return to the d21177 1 a21177 1 ‘exceptionHook’. Normally you just use: d21181 2 a21182 2 but if before calling ‘set_debug_traps’, you set it to point to a function in your program, that function is called when ‘GDB’ d21184 2 a21185 2 function indicated by ‘exceptionHook’ is called with one parameter: an ‘int’ which is the exception number. d21251 1 a21251 1 many native BSD configurations. This is implemented as a special ‘kvm’ d21253 1 a21253 1 running kernel into GDB and connect to the ‘kvm’ target: d21262 1 a21262 1 Once connected to the ‘kvm’ target, the following commands are d21265 2 a21266 2 ‘kvm pcb’ Set current context from the “Process Control Block” (PCB) address. d21268 1 a21268 1 ‘kvm proc’ d21281 1 a21281 1 supported interface, the command ‘info proc’ is available to report d21285 1 a21285 1 One supported interface is a facility called ‘/proc’ that can be used d21297 2 a21298 2 ‘info proc’ ‘info proc PROCESS-ID’ d21306 1 a21306 1 On some systems, PROCESS-ID can be of the form ‘[PID]/TID’ which d21309 1 a21309 1 debugged (the leading ‘/’ still needs to be present, or else GDB d21312 1 a21312 1 ‘info proc cmdline’ d21316 1 a21316 1 ‘info proc cwd’ d21320 1 a21320 1 ‘info proc exe’ d21324 1 a21324 1 ‘info proc files’ d21351 1 a21351 1 ‘info proc mappings’ d21359 2 a21360 2 ‘info proc stat’ ‘info proc status’ d21364 1 a21364 1 time; its stack size; its ‘nice’ value; etc. These commands are d21367 2 a21368 2 For GNU/Linux systems, see the ‘proc’ man page for more information (type ‘man 5 proc’ from your shell prompt). d21370 2 a21371 2 For FreeBSD and NetBSD systems, ‘info proc stat’ is an alias for ‘info proc status’. d21373 1 a21373 1 ‘info proc all’ d21375 1 a21375 1 the above ‘info proc’ subcommands. d21377 2 a21378 2 ‘set procfs-trace’ This command enables and disables tracing of ‘procfs’ API calls. d21380 2 a21381 2 ‘show procfs-trace’ Show the current state of ‘procfs’ API call tracing. d21383 2 a21384 2 ‘set procfs-file FILE’ Tell GDB to write ‘procfs’ API trace to the named FILE. GDB d21388 2 a21389 2 ‘show procfs-file’ Show the file to which ‘procfs’ API trace is written. d21391 4 a21394 4 ‘proc-trace-entry’ ‘proc-trace-exit’ ‘proc-untrace-entry’ ‘proc-untrace-exit’ d21396 1 a21396 1 from the ‘syscall’ interface. d21398 1 a21398 1 ‘info pidlist’ d21402 1 a21402 1 ‘info meminfo’ d21413 1 a21413 1 DJGPP programs are 32-bit protected-mode programs that use the “DPMI” d21421 1 a21421 1 ‘info dos’ d21425 1 a21425 1 ‘info dos sysinfo’ d21430 3 a21432 3 ‘info dos gdt’ ‘info dos ldt’ ‘info dos idt’ d21459 1 a21459 1 outside the data segment's limit (i.e. “garbled”). d21461 2 a21462 2 ‘info dos pde’ ‘info dos pte’ d21472 2 a21473 2 Without an argument, ‘info dos pde’ displays the entire Page Directory, and ‘info dos pte’ displays all the entries in all of d21475 2 a21476 2 ‘info dos pde’ command means display only that entry from the Page Directory table. An argument given to the ‘info dos pte’ command d21480 1 a21480 1 These commands are useful when your program uses “DMA” (Direct d21486 1 a21486 1 ‘info dos address-pte ADDR’ d21492 1 a21492 1 for the page where a variable ‘i’ is stored: d21498 2 a21499 2 This says that ‘i’ is stored at offset ‘0xd30’ from the page whose physical base address is ‘0x02698000’, and shows all the attributes d21502 2 a21503 2 Note that you must cast the addresses of variables to a ‘char *’, since otherwise the value of ‘__djgpp_base_address’, the base d21505 3 a21507 3 added using the rules of C pointer arithmetic: if ‘i’ is declared an ‘int’, GDB will add 4 times the value of ‘__djgpp_base_address’ to the address of ‘i’. d21516 2 a21517 2 (The ‘+ 3’ offset is because the transfer buffer's address is the 3rd member of the ‘_go32_info_block’ structure.) The output d21519 2 a21520 2 conventional memory 1:1, i.e. the physical (‘0x00029000’ + ‘0x110’) and linear (‘0x29110’) addresses are identical. d21528 2 a21529 2 ‘set com1base ADDR’ This command sets the base I/O port address of the ‘COM1’ serial d21532 3 a21534 3 ‘set com1irq IRQ’ This command sets the “Interrupt Request” (‘IRQ’) line to use for the ‘COM1’ serial port. d21536 2 a21537 2 There are similar commands ‘set com2base’, ‘set com3irq’, etc. for setting the port address and the ‘IRQ’ lines for the other 3 COM d21540 2 a21541 2 The related commands ‘show com1base’, ‘show com1irq’ etc. display the current settings of the base address and the ‘IRQ’ lines used d21544 1 a21544 1 ‘info serial’ d21559 3 a21561 3 MS-Windows programs that call ‘SetConsoleMode’ to switch off the special meaning of the ‘Ctrl-C’ keystroke cannot be interrupted by typing ‘C-c’. For this reason, GDB on MS-Windows supports ‘C-’ d21563 1 a21563 1 the debuggee even if it ignores ‘C-c’. d21569 1 a21569 1 ‘info w32’ d21573 1 a21573 1 ‘info w32 selector’ d21575 1 a21575 1 ‘GetThreadSelectorEntry’ function. It takes an optional argument d21580 1 a21580 1 ‘info w32 thread-information-block’ d21583 1 a21583 1 ‘$fs’ selector for 32-bit programs and ‘$gs’ for 64-bit programs). d21585 1 a21585 1 ‘signal-event ID’ d21591 7 a21597 7 ‘HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AeDebug’ and/or ‘HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\AeDebug’ (for x86_64 versions): − ‘Debugger’ (REG_SZ) -- a command to launch the debugger. Suggested command is: ‘FULLY-QUALIFIED-PATH-TO-GDB.EXE -ex "attach %ld" -ex "signal-event %ld" -ex "continue"’. d21599 2 a21600 2 The first ‘%ld’ will be replaced by the process ID of the crashing process, the second ‘%ld’ will be replaced by the ID d21604 1 a21604 1 − ‘Auto’ (REG_SZ) -- either ‘1’ or ‘0’. ‘1’ will make the d21606 1 a21606 1 automatically, ‘0’ will cause a dialog box with "OK" and d21610 3 a21612 3 ‘set cygwin-exceptions MODE’ If MODE is ‘on’, GDB will break on exceptions that happen inside the Cygwin DLL. If MODE is ‘off’, GDB will delay recognition of d21616 1 a21616 1 ‘off’ to avoid annoying GDB users with false ‘SIGSEGV’ signals. d21618 1 a21618 1 ‘show cygwin-exceptions’ d21622 3 a21624 3 ‘set new-console MODE’ If MODE is ‘on’ the debuggee will be started in a new console on next start. If MODE is ‘off’, the debuggee will be started in the d21627 1 a21627 1 ‘show new-console’ d21631 1 a21631 1 ‘set new-group MODE’ d21634 1 a21634 1 way the Windows OS handles ‘Ctrl-C’. d21636 1 a21636 1 ‘show new-group’ d21639 1 a21639 1 ‘set debugevents’ d21644 1 a21644 1 the Windows ‘OutputDebugString’ API call. d21646 1 a21646 1 ‘set debugexec’ d21650 1 a21650 1 ‘set debugexceptions’ d21654 1 a21654 1 ‘set debugmemory’ d21658 1 a21658 1 ‘set shell’ d21662 1 a21662 1 ‘show shell’ d21677 1 a21677 1 ‘kernel32.dll’). When GDB doesn't recognize any debugging symbols in a d21692 2 a21693 2 DLL name, for instance ‘KERNEL32!CreateFileA’. The plain name is also entered into the symbol table, so ‘CreateFileA’ is often sufficient. In d21703 2 a21704 2 If in doubt, try the ‘info functions’ and ‘info variables’ commands or even ‘maint print msymbols’ (*note Symbols::). Here's an example: d21767 1 a21767 1 a break point within a shared DLL like ‘kernel32.dll’ is completely d21779 2 a21780 2 ‘set signals’ ‘set sigs’ d21783 1 a21783 1 by this command. ‘sigs’ is a shorthand alias for ‘signals’. d21785 2 a21786 2 ‘show signals’ ‘show sigs’ d21789 3 a21791 3 ‘set signal-thread’ ‘set sigthread’ This command tells GDB which thread is the ‘libc’ signal thread. d21793 1 a21793 1 ‘set sigthread’ is the shorthand alias of ‘set signal-thread’. d21795 2 a21796 2 ‘show signal-thread’ ‘show sigthread’ d21800 1 a21800 1 ‘set stopped’ d21802 1 a21802 1 with the ‘SIGSTOP’ signal. The stopped process can be continued by d21805 1 a21805 1 ‘show stopped’ d21808 1 a21808 1 ‘set exceptions’ d21814 1 a21814 1 ‘show exceptions’ d21817 1 a21817 1 ‘set task pause’ d21822 1 a21822 1 you can use ‘set thread default pause on’ or ‘set thread pause on’ d21825 1 a21825 1 ‘show task pause’ d21828 1 a21828 1 ‘set task detach-suspend-count’ d21832 1 a21832 1 ‘show task detach-suspend-count’ d21835 2 a21836 2 ‘set task exception-port’ ‘set task excp’ d21838 2 a21839 2 exceptions. The argument should be the value of the “send rights” of the task. ‘set task excp’ is a shorthand alias. d21841 1 a21841 1 ‘set noninvasive’ d21844 1 a21844 1 same as using ‘set task pause’, ‘set exceptions’, and ‘set signals’ d21847 7 a21853 7 ‘info send-rights’ ‘info receive-rights’ ‘info port-rights’ ‘info port-sets’ ‘info dead-names’ ‘info ports’ ‘info psets’ d21856 2 a21857 2 task. There are also shorthand aliases: ‘info ports’ for ‘info port-rights’ and ‘info psets’ for ‘info port-sets’. d21859 1 a21859 1 ‘set thread pause’ d21865 2 a21866 2 the whole task is suspended. However, if you used ‘set task pause off’ (see above), this command comes in handy to suspend only the d21869 1 a21869 1 ‘show thread pause’ d21872 1 a21872 1 ‘set thread run’ d21875 1 a21875 1 ‘show thread run’ d21878 1 a21878 1 ‘set thread detach-suspend-count’ d21881 2 a21882 2 GDB when it notices the thread; use ‘set thread takeover-suspend-count’ to force it to an absolute value. d21884 1 a21884 1 ‘show thread detach-suspend-count’ d21887 2 a21888 2 ‘set thread exception-port’ ‘set thread excp’ d21890 2 a21891 2 overrides the port set by ‘set task exception-port’ (see above). ‘set thread excp’ is the shorthand alias. d21893 1 a21893 1 ‘set thread takeover-suspend-count’ d21898 5 a21902 5 ‘set thread default’ ‘show thread default’ Each of the above ‘set thread’ commands has a ‘set thread default’ counterpart (e.g., ‘set thread default pause’, ‘set thread default exception-port’, etc.). The ‘thread default’ variety of commands d21915 1 a21915 1 ‘set debug darwin NUM’ d21919 1 a21919 1 ‘show debug darwin’ d21922 1 a21922 1 ‘set debug mach-o NUM’ d21924 1 a21924 1 is reading Darwin object files. (“Mach-O” is the file format used d21929 1 a21929 1 ‘show debug mach-o’ d21932 2 a21933 2 ‘set mach-exceptions on’ ‘set mach-exceptions off’ d21940 1 a21940 1 ‘show mach-exceptions’ d21956 2 a21957 2 For example, FreeBSD 12 introduced a new variant of the ‘kevent’ system call and catching the ‘kevent’ system call by name catches both d21989 1 a21989 1 ‘sim COMMAND’ d22016 1 a22016 1 ‘set debug arc’ d22021 1 a22021 1 ‘show debug arc’ d22024 1 a22024 1 ‘maint print arc arc-instruction ADDRESS’ d22036 1 a22036 1 ‘set arm disassembler’ d22038 1 a22038 1 ‘"std"’ style is the standard style. d22040 1 a22040 1 ‘show arm disassembler’ d22043 1 a22043 1 ‘set arm apcs32’ d22046 1 a22046 1 ‘show arm apcs32’ d22049 1 a22049 1 ‘set arm fpu FPUTYPE’ d22053 1 a22053 1 ‘auto’ d22055 1 a22055 1 ‘softfpa’ d22058 1 a22058 1 ‘fpa’ d22060 1 a22060 1 ‘softvfp’ d22062 1 a22062 1 ‘vfp’ d22065 1 a22065 1 ‘show arm fpu’ d22068 1 a22068 1 ‘set arm abi’ d22071 1 a22071 1 ‘show arm abi’ d22074 1 a22074 1 ‘set arm fallback-mode (arm|thumb|auto)’ d22078 2 a22079 2 ‘auto’, which causes GDB to use the current execution mode (from the ‘T’ bit in the ‘CPSR’ register). d22081 1 a22081 1 ‘show arm fallback-mode’ d22084 1 a22084 1 ‘set arm force-mode (arm|thumb|auto)’ d22086 3 a22088 3 instructions are ARM or Thumb. The default is ‘auto’, which causes GDB to use the symbol table and then the setting of ‘set arm fallback-mode’. d22090 1 a22090 1 ‘show arm force-mode’ d22093 1 a22093 1 ‘set arm unwind-secure-frames’ d22099 1 a22099 1 ‘show arm unwind-secure-frames’ d22102 1 a22102 1 ‘set debug arm’ d22106 1 a22106 1 ‘show debug arm’ d22109 1 a22109 1 ‘target sim [SIMARGS] ...’ d22112 1 a22112 1 ‘--swi-support=TYPE’ d22115 1 a22115 1 values. The default value is ‘all’. d22117 5 a22121 5 ‘none’ ‘demon’ ‘angel’ ‘redboot’ ‘all’ d22129 1 a22129 1 ‘target sim [SIMARGS] ...’ d22132 1 a22132 1 ‘--skb-data-offset=OFFSET’ d22134 1 a22134 1 ‘skb_data’ field in the kernel ‘struct sk_buff’ structure. d22159 3 a22161 3 a ‘gdbserver’ interface to the board. By default ‘xmd’ uses port ‘1234’. (While it is possible to change this default port, it requires the use of undocumented ‘xmd’ commands. Contact Xilinx support if you d22166 1 a22166 1 ‘target remote :1234’ d22168 1 a22168 1 the same system as ‘xmd’. d22170 1 a22170 1 ‘target remote XMD-HOST:1234’ d22172 1 a22172 1 ‘xmd’ running on a different system named XMD-HOST. d22174 1 a22174 1 ‘load’ d22177 1 a22177 1 ‘set debug microblaze N’ d22180 1 a22180 1 ‘show debug microblaze N’ d22191 5 a22195 5 ‘set mipsfpu double’ ‘set mipsfpu single’ ‘set mipsfpu none’ ‘set mipsfpu auto’ ‘show mipsfpu’ d22197 1 a22197 1 coprocessor, you should use the command ‘set mipsfpu none’ (if you d22204 3 a22206 3 the command ‘set mipsfpu single’. The default double precision floating point coprocessor may be selected using ‘set mipsfpu double’. d22209 2 a22210 2 floating point, so ‘set mipsfpu on’ will select double precision and ‘set mipsfpu off’ will select no floating point. d22212 2 a22213 2 As usual, you can inquire about the ‘mipsfpu’ variable with ‘show mipsfpu’. d22228 1 a22228 1 ‘target sim’ d22233 1 a22233 1 and connect using ‘target remote’. d22235 1 a22235 1 Example: ‘target sim’ d22237 1 a22237 1 ‘set debug or1k’ d22241 1 a22241 1 ‘show debug or1k’ d22258 1 a22258 1 debug register (either the ‘exact-watchpoints’ option is on and the d22264 1 a22264 1 ranged hardware watchpoints, unless the ‘exact-watchpoints’ option is d22275 1 a22275 1 discussion about the ‘mask’ argument in *note Set Watchpoints::. d22277 2 a22278 2 PowerPC embedded processors support hardware accelerated “ranged breakpoints”. A ranged breakpoint stops execution of the inferior d22280 1 a22280 1 was set at. To set a ranged breakpoint in GDB, use the ‘break-range’ d22285 1 a22285 1 ‘break-range START-LOCSPEC, END-LOCSPEC’ d22298 2 a22299 2 ‘set powerpc soft-float’ ‘show powerpc soft-float’ d22304 2 a22305 2 ‘set powerpc vector-abi’ ‘show powerpc vector-abi’ d22307 3 a22309 3 arguments and return values. The valid options are ‘auto’; ‘generic’, to avoid vector registers even if they are present; ‘altivec’, to use AltiVec registers; and ‘spe’ to use SPE d22313 2 a22314 2 ‘set powerpc exact-watchpoints’ ‘show powerpc exact-watchpoints’ d22328 1 a22328 1 ‘info io_registers’ d22341 2 a22342 2 ‘set cris-version VER’ Set the current CRIS version to VER, either ‘10’ or ‘32’. The CRIS d22346 1 a22346 1 ‘show cris-version’ d22349 1 a22349 1 ‘set cris-dwarf2-cfi’ d22351 2 a22352 2 ‘on’. Change to ‘off’ when using ‘gcc-cris’ whose version is below ‘R59’. d22354 1 a22354 1 ‘show cris-dwarf2-cfi’ d22357 1 a22357 1 ‘set cris-mode MODE’ d22359 2 a22360 2 debugging in guru mode, in which case it should be set to ‘guru’ (the default is ‘normal’). d22362 1 a22362 1 ‘show cris-mode’ d22373 1 a22373 1 ‘set sh calling-convention CONVENTION’ d22375 2 a22376 2 Allowed values are ‘gcc’, which is the default setting, and ‘renesas’. With the ‘gcc’ setting, functions are called using the d22380 1 a22380 1 convention. If the calling convention is set to ‘renesas’, the d22383 1 a22383 1 ‘gcc’ if debug information is missing, or the compiler does not d22386 1 a22386 1 ‘show sh calling-convention’ d22420 1 a22420 1 ‘set debug aarch64’ d22424 1 a22424 1 ‘show debug aarch64’ d22432 2 a22433 2 ‘$z0’ through ‘$z31’, vector predicate registers ‘$p0’ through ‘$p15’, and the ‘$ffr’ register. In addition, the pseudo register ‘$vg’ will be d22435 1 a22435 1 represents the number of 64-bit chunks in an SVE ‘z’ register. d22437 2 a22438 2 If the vector length changes, then the ‘$vg’ register will be updated, but the lengths of the ‘z’ and ‘p’ registers will not change. d22445 1 a22445 1 • VL: The vector length, in bytes. It defines the size of each ‘Z’ d22448 1 a22448 1 • VQ: The number of 128 bit units in VL. This is mostly used d22451 1 a22451 1 • VG: The number of 64 bit units in VL. This is mostly used d22462 1 a22462 1 by providing a 2-dimensional register ‘ZA’, which is a square matrix of d22466 2 a22467 2 Similarly to SVE, where the size of each ‘Z’ register is directly related to the vector length (VL for short), the SME ‘ZA’ matrix d22471 1 a22471 1 The ‘ZA’ register state can be either active or inactive, if it is d22487 3 a22489 3 • SVL: The streaming vector length, in bytes. It defines the size of each dimension of the 2-dimensional square ‘ZA’ matrix. The total size of ‘ZA’ is therefore SVL by SVL. d22494 1 a22494 1 • SVQ: The number of 128 bit units in SVL, also known as streaming d22498 1 a22498 1 • SVG: The number of 64 bit units in SVL. This is mostly used d22502 2 a22503 2 Matrix Extension (SME) is present, then GDB will make the ‘ZA’ register available. GDB will also make the ‘SVG’ register and ‘SVCR’ d22506 2 a22507 2 The ‘ZA’ register is a 2-dimensional square SVL by SVL matrix of bytes. To simplify the representation and access to the ‘ZA’ register d22510 2 a22511 2 If the user wants to index the ‘ZA’ register as a matrix, it is possible to reference ‘ZA’ as ‘ZA[I][J]’, where I is the row number and d22514 2 a22515 2 The ‘SVG’ register always contains the streaming vector granule (SVG) for the current thread. From the value of register ‘SVG’ we can easily d22518 1 a22518 1 The ‘SVCR’ pseudo-register (streaming vector control register) is a d22526 2 a22527 2 If the ZA bit is 1, it means the ‘ZA’ register is being used and has meaningful contents. If the ZA bit is 0, the ‘ZA’ register is d22530 1 a22530 1 For convenience and simplicity, if the ZA bit is 0, the ‘ZA’ register d22533 2 a22534 2 If SVL changes during the execution of a program, then the ‘ZA’ register size and the bits in the ‘SVCR’ pseudo-register will be updated d22538 1 a22538 1 program by modifying the ‘SVG’ register value. d22540 1 a22540 1 Whenever the ‘SVG’ register is modified with a new value, the d22543 1 a22543 1 • The ZA and SM bits will be cleared in the ‘SVCR’ pseudo-register. d22545 1 a22545 1 • The ‘ZA’ register will have a new size and its state will be d22549 1 a22549 1 • If the SM bit was 1, the SVE registers will be reset to having d22551 1 a22551 1 prior to modifying the ‘SVG’ register, there will be no observable d22554 1 a22554 1 The possible values for the ‘SVG’ register are 2, 4, 8, 16, 32. d22558 1 a22558 1 The minimum size of the ‘ZA’ register is 16 x 16 (256) bytes, and the d22560 1 a22560 1 set, the size of the ‘ZA’ register is the size of all the SVE ‘Z’ d22563 1 a22563 1 The ‘ZA’ register can also be accessed using tiles and tile slices. d22566 1 a22566 1 elements within the ‘ZA’ register. d22568 2 a22569 2 The tile pseudo-registers have the following naming pattern: ‘ZA’. d22571 3 a22573 3 There is a total of 31 ‘ZA’ tile pseudo-registers. They are ‘ZA0B’, ‘ZA0H’ through ‘ZA1H’, ‘ZA0S’ through ‘ZA3S’, ‘ZA0D’ through ‘ZA7D’ and ‘ZA0Q’ through ‘ZA15Q’. d22576 1 a22576 1 contiguous elements within the ‘ZA’ register. d22579 1 a22579 1 ‘ZA ’. d22581 3 a22583 3 There are up to 16 tiles (0 ~ 15), the direction can be either ‘v’ (vertical) or ‘h’ (horizontal), the qualifiers can be ‘b’ (byte), ‘h’ (halfword), ‘s’ (word), ‘d’ (doubleword) and ‘q’ (quadword) and there d22593 1 a22593 1 currently-available ‘ZA’ pseudo-registers. Pseudo-registers that don't d22609 1 a22609 1 the ‘SVCR’ pseudo-register bits nor the ‘ZA’ register contents. *Note d22614 2 a22615 2 involving the ‘TPIDR2’ register is not yet supported by GDB, though the ‘TPIDR2’ register is known and supported by GDB. d22617 2 a22618 2 Lastly, an important limitation for ‘gdbserver’ is its inability to communicate SVL changes to GDB. This means ‘gdbserver’, even though it d22622 1 a22622 1 values for the ‘ZA’ register and incorrect values for SVE registers d22634 2 a22635 2 • The ability to address the ‘ZA’ array through groups of one-dimensional ‘ZA’ array vectors, as opposed to ‘ZA’ tiles with 2 d22638 1 a22638 1 • Instructions to operate on groups of SVE ‘Z’ registers and ‘ZA’ d22641 1 a22641 1 • A new 512 bit ‘ZT0’ lookup table register, for data decompression. d22644 1 a22644 1 Matrix Extension 2 (SME2) is present, then GDB will make the ‘ZT0’ d22647 2 a22648 2 The ‘ZT0’ register is only considered active when the ‘ZA’ register state is active, therefore when the ZA bit of the ‘SVCR’ is 1. d22650 2 a22651 2 When the ZA bit of ‘SVCR’ is 0, that means the ‘ZA’ register state is not active, which means the ‘ZT0’ register state is also not active. d22653 1 a22653 1 When ‘ZT0’ is not active, it is comprised of zeroes, just like ‘ZA’. d22655 1 a22655 1 Similarly to the ‘ZA’ register, if the ‘ZT0’ state is not active and d22657 2 a22658 2 non-zero, then GDB will initialize the ‘ZA’ register state as well, which means the ‘SVCR’ ZA bit gets set to 1. d22669 1 a22669 1 register ‘$lr’ is pointing to an PAC function its value will be masked. d22672 1 a22672 1 as part of the ‘addr_flags’ field. d22700 4 a22703 4 A special register, ‘tag_ctl’, is made available through the ‘org.gnu.gdb.aarch64.mte’ feature. This register exposes some options that can be controlled at runtime and emulates the ‘prctl’ option ‘PR_SET_TAGGED_ADDR_CTRL’. For further information, see the d22707 2 a22708 2 ‘gcore’ command and reading memory tag data from core files generated by the ‘gcore’ command or the Linux kernel. d22716 2 a22717 2 tags from a particular memory region (using the ‘m’ modifier to the ‘x’ command, using the ‘print’ command or using the various ‘memory-tag’ d22731 6 a22736 6 ‘set struct-convention MODE’ Set the convention used by the inferior to return ‘struct’s and ‘union’s from functions to MODE. Possible values of MODE are ‘"pcc"’, ‘"reg"’, and ‘"default"’ (the default). ‘"default"’ or ‘"pcc"’ means that ‘struct’s are returned on the stack, while ‘"reg"’ means that a ‘struct’ or a ‘union’ whose size is 1, 2, 4, d22739 2 a22740 2 ‘show struct-convention’ Show the current setting of the convention to return ‘struct’s from d22743 1 a22743 1 21.4.2.1 Intel “Memory Protection Extensions” (MPX). d22746 2 a22747 2 Memory Protection Extension (MPX) adds the bound registers ‘BND0’ (1) through ‘BND3’. Bound registers store a pair of 64-bit values which are d22754 2 a22755 2 ‘BND0’ through ‘BND3’ are represented in GDB as ‘bnd0raw’ through ‘bnd3raw’. Pseudo registers ‘bnd0’ through ‘bnd3’ display the upper d22757 2 a22758 2 value, i.e. when upper bound in ‘bnd0raw’ is 0 in the GDB ‘bnd0’ it will be ‘0xfff...’. In this sense it can also be noted that the upper bounds d22781 1 a22781 1 ‘show mpx bound POINTER’ d22784 1 a22784 1 ‘set mpx bound POINTER, LBOUND, UBOUND’ d22826 9 a22834 9 • ‘$st0’ to ‘st7’: ‘ST(0)’ to ‘ST(7)’ floating-point registers • ‘$fctrl’: control word register (‘FCW’) • ‘$fstat’: status word register (‘FSW’) • ‘$ftag’: tag word (‘FTW’) • ‘$fiseg’: last instruction pointer segment • ‘$fioff’: last instruction pointer • ‘$foseg’: last data pointer segment • ‘$fooff’: last data pointer • ‘$fop’: last opcode d22863 1 a22863 1 ‘set heuristic-fence-post LIMIT’ d22867 1 a22867 1 bytes ‘heuristic-fence-post’ must search and therefore the longer d22871 1 a22871 1 ‘show heuristic-fence-post’ d22880 1 a22880 1 ‘set mips abi ARG’ d22884 1 a22884 1 ‘auto’ d22887 6 a22892 6 ‘o32’ ‘o64’ ‘n32’ ‘n64’ ‘eabi32’ ‘eabi64’ d22894 1 a22894 1 ‘show mips abi’ d22897 1 a22897 1 ‘set mips compression ARG’ d22906 2 a22907 2 Possible values of ARG are ‘mips16’ and ‘micromips’. The default compressed ISA encoding is ‘mips16’, as executables containing d22920 1 a22920 1 ‘show mips compression’ d22924 2 a22925 2 ‘set mipsfpu’ ‘show mipsfpu’ d22928 1 a22928 1 ‘set mips mask-address ARG’ d22931 1 a22931 1 ‘on’, ‘off’, or ‘auto’. The latter is the default setting, which d22934 1 a22934 1 ‘show mips mask-address’ d22938 1 a22938 1 ‘set remote-mips64-transfers-32bit-regs’ d22942 1 a22942 1 and 64 bits for other registers, set this option to ‘on’. d22944 1 a22944 1 ‘show remote-mips64-transfers-32bit-regs’ d22948 1 a22948 1 ‘set debug mips’ d22952 1 a22952 1 ‘show debug mips’ d22964 1 a22964 1 ‘set debug hppa’ d22968 1 a22968 1 ‘show debug hppa’ d22971 1 a22971 1 ‘maint print unwind ADDRESS’ d22985 1 a22985 1 register like ‘f0’ or ‘f2’. d22987 3 a22989 3 The pseudo-registers go from ‘$dl0’ through ‘$dl15’, and are formed by joining the even/odd register pairs ‘f0’ and ‘f1’ for ‘$dl0’, ‘f2’ and ‘f3’ for ‘$dl1’ and so on. d22992 1 a22992 1 64-bit wide Extended Floating Point Registers (‘f32’ through ‘f63’). d23003 1 a23003 1 ‘set debug nios2’ d23007 1 a23007 1 ‘show debug nios2’ d23037 1 a23037 1 ‘adi (examine | x) [ / N ] ADDR’ d23039 1 a23039 1 The ‘adi examine’ command displays the value of one ADI version tag d23055 1 a23055 1 ‘adi (assign | a) [ / N ] ADDR = TAG’ d23057 1 a23057 1 The ‘adi assign’ command is used to assign new ADI version tag to d23085 1 a23085 1 ‘maint info bdccsr’ d23143 1 a23143 1 The ‘info sharedlibrary’ command will show the AMD GPU code objects as d23158 1 a23158 1 For a ‘file’ URI, the path portion is the file on disk containing the d23164 1 a23164 1 For a ‘memory’ URI, the path portion is the process id of the process d23170 1 a23170 1 The ‘info sharedlibrary’ command may therefore show the same code object d23192 1 a23192 1 ‘SIGILL’ d23195 2 a23196 2 ‘SIGTRAP’ Execution of a ‘S_TRAP’ instruction other than: d23198 1 a23198 1 • ‘S_TRAP 1’ which is used by GDB to insert breakpoints. d23200 1 a23200 1 • ‘S_TRAP 2’ which raises ‘SIGABRT’. d23202 2 a23203 2 ‘SIGABRT’ Execution of a ‘S_TRAP 2’ instruction. d23205 1 a23205 1 ‘SIGFPE’ d23210 1 a23210 1 • Floating point operation is invalid. d23212 1 a23212 1 • Floating point operation had subnormal input that was rounded d23215 1 a23215 1 • Floating point operation performed a division by zero. d23217 1 a23217 1 • Floating point operation produced an overflow result. The d23220 1 a23220 1 • Floating point operation produced an underflow result. A d23223 1 a23223 1 • Floating point operation produced an inexact result. d23225 1 a23225 1 • Integer operation performed a division by zero. d23228 1 a23228 1 ‘set $mode’ command can be used to change the AMD GPU wavefront's d23230 1 a23230 1 raise signals. The ‘print $trapsts’ command can be used to inspect d23234 1 a23234 1 ‘SIGBUS’ d23238 1 a23238 1 ‘SIGSEGV’ d23254 1 a23254 1 ‘set amdgpu precise-memory MODE’ d23258 1 a23258 1 ‘off’ d23263 1 a23263 1 ‘on’ d23270 2 a23271 2 The ‘amdgpu precise-memory’ parameter is per-inferior. When an inferior forks or execs, or the user uses the ‘clone-inferior’ d23275 1 a23275 1 ‘show amdgpu precise-memory’ d23281 2 a23282 2 The ‘set debug amd-dbgapi’ command can be used to enable diagnostic messages in the ‘amd-dbgapi’ target. The ‘show debug amd-dbgapi’ d23285 4 a23288 4 The ‘set debug amd-dbgapi-lib log-level LEVEL’ command can be used to enable diagnostic messages from the ‘amd-dbgapi’ library (which GDB uses under the hood). The ‘show debug amd-dbgapi-lib log-level’ command displays the current ‘amd-dbgapi’ library log level. *Note set debug d23314 2 a23315 2 Setting the ‘HIP_ENABLE_DEFERRED_LOADING’ environment variable to ‘0’ can be used to disable deferred code object loading by the HIP d23317 1 a23317 1 inferior reaches the beginning of the ‘main’ function. d23319 1 a23319 1 3. If no CPU thread is running, then ‘Ctrl-C’ is not able to stop AMD d23321 1 a23321 1 ‘scheduler-locking’ after the whole program stopped, and then d23329 2 a23330 2 the wavefront's work-group position. The ‘info threads’ command will display this missing information with a ‘?’. d23335 1 a23335 1 If the ‘HSA_ENABLE_DEBUG’ environment variable is set to ‘1’ when d23346 1 a23346 1 You can alter the way GDB interacts with you by using the ‘set’ command. d23371 2 a23372 2 called the “prompt”. This string is normally ‘(gdb)’. You can change the prompt string with the ‘set prompt’ command. For instance, when d23376 1 a23376 1 _Note:_ ‘set prompt’ does not add a space for you after the prompt d23380 1 a23380 1 ‘set prompt NEWPROMPT’ d23383 2 a23384 2 ‘show prompt’ Prints a line of the form: ‘Gdb's prompt is: YOUR-PROMPT’ d23389 1 a23389 1 ‘set extended-prompt PROMPT’ d23403 1 a23403 1 ‘show extended-prompt’ d23405 1 a23405 1 of the prompt string with ‘set extended-prompt’, are replaced with d23414 1 a23414 1 GDB reads its input commands via the “Readline” interface. This GNU d23417 1 a23417 1 “vi”-style inline editing of commands, ‘csh’-like history substitution, d23421 1 a23421 1 command ‘set’. d23423 2 a23424 2 ‘set editing’ ‘set editing on’ d23427 1 a23427 1 ‘set editing off’ d23430 1 a23430 1 ‘show editing’ d23434 1 a23434 1 interface. Users unfamiliar with GNU Emacs or ‘vi’ are encouraged to d23437 2 a23438 2 GDB sets the Readline application name to ‘gdb’. This is useful for conditions in ‘.inputrc’. d23440 2 a23441 2 GDB defines a bindable Readline command, ‘operate-and-get-next’. This is bound to ‘C-o’ by default. This command accepts the current d23460 1 a23460 1 state which is seen by users, prefix it with ‘server ’ (*note Server d23467 1 a23467 1 history, use the ‘output’ command instead of the ‘print’ command. d23471 1 a23471 1 ‘set history filename [FNAME]’ d23477 2 a23478 2 defaults to the value of the environment variable ‘GDBHISTFILE’, or to ‘./.gdb_history’ (‘./_gdb_history’ on MS-DOS) if this variable d23481 1 a23481 1 The ‘GDBHISTFILE’ environment variable is read after processing any d23483 1 a23483 1 commands passed using command line options (for example, ‘-ex’). d23485 1 a23485 1 If the FNAME argument is not given, or if the ‘GDBHISTFILE’ is the d23489 2 a23490 2 ‘set history save’ ‘set history save on’ d23492 1 a23492 1 the ‘set history filename’ command. By default, this option is d23494 2 a23495 2 ‘set history filename’ is set to the empty string then history saving is disabled, even when ‘set history save’ is ‘on’. d23497 3 a23499 3 ‘set history save off’ Don't record the command history into the file specified by ‘set history filename’ when GDB exits. d23501 2 a23502 2 ‘set history size SIZE’ ‘set history size unlimited’ d23505 3 a23507 3 ‘GDBHISTSIZE’, or to 256 if this variable is not set. Non-numeric values of ‘GDBHISTSIZE’ are ignored. If SIZE is ‘unlimited’ or if ‘GDBHISTSIZE’ is either a negative number or the empty string, then d23510 1 a23510 1 The ‘GDBHISTSIZE’ environment variable is read after processing any d23512 1 a23512 1 commands passed using command line options (for example, ‘-ex’). d23514 2 a23515 2 ‘set history remove-duplicates COUNT’ ‘set history remove-duplicates unlimited’ d23520 1 a23520 1 list. If COUNT is ‘unlimited’ then this lookbehind is unbounded. d23527 1 a23527 1 History expansion assigns special meaning to the character ‘!’. d23530 3 a23532 3 Since ‘!’ is also the logical not operator in C, history expansion is off by default. If you decide to enable history expansion with the ‘set history expansion on’ command, you may sometimes need to follow ‘!’ d23535 1 a23535 1 not attempt substitution on the strings ‘!=’ and ‘!(’, even when history d23540 2 a23541 2 ‘set history expansion on’ ‘set history expansion’ d23544 1 a23544 1 ‘set history expansion off’ d23547 5 a23551 5 ‘show history’ ‘show history filename’ ‘show history save’ ‘show history size’ ‘show history expansion’ d23553 1 a23553 1 ‘show history’ by itself displays all four states. d23555 1 a23555 1 ‘show commands’ d23558 1 a23558 1 ‘show commands N’ d23561 1 a23561 1 ‘show commands +’ d23573 1 a23573 1 see one more page of output, ‘q’ to discard the remaining output, or ‘c’ d23582 12 a23593 12 with the value of the ‘TERM’ environment variable and the ‘stty rows’ and ‘stty cols’ settings. If this is not correct, you can override it with the ‘set height’ and ‘set width’ commands: ‘set height LPP’ ‘set height unlimited’ ‘show height’ ‘set width CPL’ ‘set width unlimited’ ‘show width’ These ‘set’ commands specify a screen height of LPP lines and a screen width of CPL characters. The associated ‘show’ commands d23596 1 a23596 1 If you specify a height of either ‘unlimited’ or zero lines, GDB d23600 1 a23600 1 Likewise, you can specify ‘set width unlimited’ or ‘set width 0’ to d23603 2 a23604 2 ‘set pagination on’ ‘set pagination off’ d23606 2 a23607 2 pagination off is the alternative to ‘set height unlimited’. Note that running GDB with the ‘--batch’ option (*note -batch: Mode d23610 1 a23610 1 ‘show pagination’ d23624 1 a23624 1 ‘set style enabled ‘on|off’’ d23626 1 a23626 1 most hosts defaulting to ‘on’. d23628 2 a23629 2 If the ‘NO_COLOR’ environment variable is set to a non-empty value, then GDB will change this to ‘off’ at startup. d23631 1 a23631 1 ‘show style enabled’ d23634 1 a23634 1 ‘set style sources ‘on|off’’ d23636 2 a23637 2 code, such as the output of the ‘list’ command, is styled. The default is ‘on’. Note that source styling only works if styling in d23646 1 a23646 1 ‘show style sources’ d23649 1 a23649 1 ‘set style tui-current-position ‘on|off’’ d23652 1 a23652 1 is ‘off’. *Note GDB Text User Interface: TUI. d23654 1 a23654 1 ‘show style tui-current-position’ d23658 1 a23658 1 ‘set style disassembler enabled ‘on|off’’ d23660 1 a23660 1 disassembler output, such as the output of the ‘disassemble’ d23662 1 a23662 1 general is enabled (with ‘set style enabled on’), and if a source d23681 1 a23681 1 unstyled disassembler output, even when this setting is ‘on’. d23684 2 a23685 2 builtin disassembler library see *note ‘maint show libopcodes-styling enabled’: maint_libopcodes_styling. d23687 1 a23687 1 ‘show style disassembler enabled’ d23690 1 a23690 1 Subcommands of ‘set style’ control specific forms of styling. These d23694 2 a23695 2 For example, the style of file names can be controlled using the ‘set style filename’ group of commands: d23697 13 a23709 13 ‘set style filename background COLOR’ Set the background to COLOR. Valid colors are ‘none’ (meaning the terminal's default color), ‘black’, ‘red’, ‘green’, ‘yellow’, ‘blue’, ‘magenta’, ‘cyan’, and‘white’. ‘set style filename foreground COLOR’ Set the foreground to COLOR. Valid colors are ‘none’ (meaning the terminal's default color), ‘black’, ‘red’, ‘green’, ‘yellow’, ‘blue’, ‘magenta’, ‘cyan’, and‘white’. ‘set style filename intensity VALUE’ Set the intensity to VALUE. Valid intensities are ‘normal’ (the default), ‘bold’, and ‘dim’. d23711 2 a23712 2 The ‘show style’ command and its subcommands are styling a style name in their output using its own style. So, use ‘show style’ to see the d23717 1 a23717 1 ‘filename’ d23721 1 a23721 1 ‘function’ d23723 1 a23723 1 ‘set style function’ family of commands. By default, this style's d23728 1 a23728 1 (*note ‘set style disassembler enabled’: d23731 1 a23731 1 ‘variable’ d23733 1 a23733 1 ‘set style variable’ family of commands. By default, this style's d23736 3 a23738 3 ‘address’ Control the styling of addresses. These are managed with the ‘set style address’ family of commands. By default, this style's d23743 1 a23743 1 ‘set style disassembler enabled’: style_disassembler_enabled.). d23745 1 a23745 1 ‘version’ d23748 2 a23749 2 version number is displayed in two places, the output of ‘show version’, and when GDB starts up. d23752 1 a23752 1 add the ‘set style version’ family of commands to the early d23755 3 a23757 3 ‘title’ Control the styling of titles. These are managed with the ‘set style title’ family of commands. By default, this style's d23760 1 a23760 1 ‘apropos’ and ‘help’ are using the title style for the command d23763 1 a23763 1 ‘highlight’ d23765 1 a23765 1 ‘set style highlight’ family of commands. By default, this style's d23768 1 a23768 1 For example, the command ‘apropos -v REGEXP’ uses the highlight d23771 1 a23771 1 ‘metadata’ d23774 1 a23774 1 annotations include the ‘repeats N times’ annotation for suppressed d23776 2 a23777 2 ‘’ and ‘’ annotations for errors and ‘’ annotations for optimized-out values in d23781 1 a23781 1 ‘tui-border’ d23784 1 a23784 1 ‘set style’. This was done for compatibility reasons, as TUI d23788 1 a23788 1 ‘tui-active-border’ d23792 1 a23792 1 ‘disassembler comment’ d23794 1 a23794 1 are managed with the ‘set style disassembler comment’ family of d23796 2 a23797 2 builtin disassembler library (*note ‘set style disassembler enabled’: style_disassembler_enabled.). By default, this style's d23800 1 a23800 1 ‘disassembler immediate’ d23802 1 a23802 1 These are managed with the ‘set style disassembler immediate’ d23804 2 a23805 2 operands that represent addresses, in that case the ‘disassembler address’ style is used. This style is only used when GDB is d23809 1 a23809 1 ‘disassembler address’ d23811 1 a23811 1 This is an alias for the ‘address’ style. d23813 1 a23813 1 ‘disassembler symbol’ d23815 1 a23815 1 This is an alias for the ‘function’ style. d23817 1 a23817 1 ‘disassembler mnemonic’ d23819 3 a23821 3 output. These are managed with the ‘set style disassembler mnemonic’ family of commands. This style is also used for assembler directives, e.g. ‘.byte’, ‘.word’, etc. This style is d23825 1 a23825 1 ‘disassembler register’ d23827 2 a23828 2 output. These are managed with the ‘set style disassembler register’ family of commands. This style is only used when GDB is d23839 3 a23841 3 the usual conventions: octal numbers begin with ‘0’, decimal numbers end with ‘.’, and hexadecimal numbers begin with ‘0x’. Numbers that neither begin with ‘0’ or ‘0x’, nor end with a ‘.’ are, by default, entered in d23846 1 a23846 1 ‘set input-radix BASE’ d23855 3 a23857 3 sets the input base to decimal. On the other hand, ‘set input-radix 10’ leaves the input radix unchanged, no matter what it was, since ‘10’, being without any leading or trailing signs of its d23859 1 a23859 1 radix is 16, ‘10’ is interpreted in hex, i.e. as 16 decimal, which d23862 1 a23862 1 ‘set output-radix BASE’ d23867 1 a23867 1 ‘show input-radix’ d23870 1 a23870 1 ‘show output-radix’ d23873 2 a23874 2 ‘set radix [BASE]’ ‘show radix’ d23876 1 a23876 1 output of numbers. ‘set radix’ sets the radix of input and output d23886 1 a23886 1 GDB can determine the “ABI” (Application Binary Interface) of your d23893 2 a23894 2 will autodetect the “OS ABI” (Operating System ABI) in use, but you can override its conclusion using the ‘set osabi’ command. One example d23901 1 a23901 1 "Newlib" OS ABI. This is useful for handling ‘setjmp’ and ‘longjmp’ when d23903 1 a23903 1 can be selected by ‘set osabi Newlib’. d23905 1 a23905 1 ‘show osabi’ d23908 1 a23908 1 ‘set osabi’ d23911 1 a23911 1 ‘set osabi ABI’ d23914 1 a23914 1 Generally, the way that an argument of type ‘float’ is passed to a d23916 4 a23919 4 prototyped (i.e. ANSI/ISO style) function, ‘float’ arguments are passed unchanged, according to the architecture's convention for ‘float’. For unprototyped (i.e. K&R style) functions, ‘float’ arguments are first promoted to type ‘double’ and then passed. d23923 1 a23923 1 is not marked as prototyped, it consults ‘set coerce-float-to-double’. d23925 3 a23927 3 ‘set coerce-float-to-double’ ‘set coerce-float-to-double on’ Arguments of type ‘float’ will be promoted to ‘double’ when passed d23930 2 a23931 2 ‘set coerce-float-to-double off’ Arguments of type ‘float’ will be passed directly to unprototyped d23934 2 a23935 2 ‘show coerce-float-to-double’ Show the current setting of promoting ‘float’ to ‘double’. d23942 2 a23943 2 use. Currently supported ABI's include "gnu-v2", for ‘g++’ versions before 3.0, "gnu-v3", for ‘g++’ versions 3.0 and later, and "hpaCC" for d23947 1 a23947 1 ‘show cp-abi’ d23950 1 a23950 1 ‘set cp-abi’ d23953 2 a23954 2 ‘set cp-abi ABI’ ‘set cp-abi auto’ d23965 1 a23965 1 “auto-loading”. While auto-loading is useful for automatically adapting d23975 1 a23975 1 ‘.gdbinit’ file) requires accordingly configured ‘auto-load safe-path’ d23981 1 a23981 1 ‘set auto-load off’ d23983 1 a23983 1 use this command with the ‘-iex’ option (*note Option d23991 2 a23992 2 files, use the ‘-nx’ option (*note Mode Options::), in addition to ‘set auto-load no’. d23994 2 a23995 2 ‘show auto-load’ Show whether auto-loading of each specific ‘auto-load’ file(s) is d24009 2 a24010 2 ‘info auto-load’ Print whether each specific ‘auto-load’ file(s) have been d24068 2 a24069 2 * Init File in the Current Directory:: ‘set/show/info auto-load local-gdbinit’ * libthread_db.so.1 file:: ‘set/show/info auto-load libthread-db’ d24071 2 a24072 2 * Auto-loading safe path:: ‘set/show/info auto-load safe-path’ * Auto-loading verbose mode:: ‘set/show debug auto-load’ d24084 2 a24085 2 Note that loading of this local ‘.gdbinit’ file also requires accordingly configured ‘auto-load safe-path’ (*note Auto-loading safe d24088 1 a24088 1 ‘set auto-load local-gdbinit [on|off]’ d24092 1 a24092 1 ‘show auto-load local-gdbinit’ d24096 1 a24096 1 ‘info auto-load local-gdbinit’ d24111 2 a24112 2 The special ‘libthread-db-search-path’ entry ‘$sdir’ is processed without checking this ‘set auto-load libthread-db’ switch as system d24114 2 a24115 2 ‘libthread-db-search-path’ entries GDB checks first if ‘set auto-load libthread-db’ is enabled before trying to open such thread debugging d24119 1 a24119 1 configured ‘auto-load safe-path’ (*note Auto-loading safe path::). d24121 1 a24121 1 ‘set auto-load libthread-db [on|off]’ d24125 1 a24125 1 ‘show auto-load libthread-db’ d24129 1 a24129 1 ‘info auto-load libthread-db’ d24142 1 a24142 1 automatically. GDB provides the ‘set auto-load safe-path’ setting to d24166 1 a24166 1 ‘set auto-load safe-path [DIRECTORIES]’ d24171 3 a24173 3 ‘FNM_PATHNAME’ for system function ‘fnmatch’ (*note fnmatch: (libc)Wildcard Matching.). If you omit DIRECTORIES, ‘auto-load safe-path’ will be reset to its default value as specified during d24176 3 a24178 3 The list of directories uses path separator (‘:’ on GNU and Unix systems, ‘;’ on MS-Windows and MS-DOS) to separate directories, similarly to the ‘PATH’ environment variable. d24180 1 a24180 1 ‘show auto-load safe-path’ d24184 1 a24184 1 ‘add-auto-load-safe-path’ d24190 2 a24191 2 This variable defaults to what ‘--with-auto-load-dir’ has been configured to (*note with-auto-load-dir::). ‘$debugdir’ and ‘$datadir’ d24193 1 a24193 1 scripts-directory::. The default ‘set auto-load safe-path’ value can be d24195 1 a24195 1 ‘--with-auto-load-safe-path’. d24197 1 a24197 1 Setting this variable to ‘/’ disables this security protection, d24199 1 a24199 1 ‘--without-auto-load-safe-path’. This variable is supposed to be set to d24209 1 a24209 1 ‘~/.gdbinit’: ‘add-auto-load-safe-path ~/src/gdb’ d24212 1 a24212 1 displayed by by ‘show auto-load safe-path’ (such as ‘/usr:/bin’ in d24215 1 a24215 1 ‘gdb -iex "set auto-load safe-path /usr:/bin:~/src/gdb" ...’ d24219 1 a24219 1 ‘gdb -iex "set auto-load safe-path /" ...’ d24224 1 a24224 1 ‘./configure --without-auto-load-safe-path’ d24232 1 a24232 1 ‘gdb -iex "set auto-load no" ...’ d24235 1 a24235 1 ‘~/.gdbinit’: ‘set auto-load no’ d24274 1 a24274 1 ‘set debug auto-load [on|off]’ d24277 1 a24277 1 ‘show debug auto-load’ d24288 1 a24288 1 on a slow machine, you may want to use the ‘set verbose’ command. This d24292 1 a24292 1 Currently, the messages controlled by ‘set verbose’ are those which d24294 1 a24294 1 ‘symbol-file’ in *note Commands to Specify Files: Files. d24296 1 a24296 1 ‘set verbose on’ d24299 1 a24299 1 ‘set verbose off’ d24302 2 a24303 2 ‘show verbose’ Displays whether ‘set verbose’ is on or off. d24310 1 a24310 1 ‘set complaints LIMIT’ d24316 1 a24316 1 ‘show complaints’ d24330 1 a24330 1 ‘set confirm off’ d24332 1 a24332 1 ‘--batch’ option (*note -batch: Mode Options.) also automatically d24335 1 a24335 1 ‘set confirm on’ d24338 1 a24338 1 ‘show confirm’ d24342 2 a24343 2 find it useful to enable “command tracing”. In this mode each command will be printed as it is executed, prefixed with one or more ‘+’ d24346 1 a24346 1 ‘set trace-commands on’ d24348 1 a24348 1 ‘set trace-commands off’ d24350 1 a24350 1 ‘show trace-commands’ d24364 1 a24364 1 ‘set exec-done-display’ d24368 1 a24368 1 ‘show exec-done-display’ d24372 1 a24372 1 ‘set debug aarch64’ d24375 1 a24375 1 ‘show debug aarch64’ d24379 1 a24379 1 ‘set debug arch’ d24382 1 a24382 1 ‘show debug arch’ d24385 1 a24385 1 ‘set debug aix-thread’ d24388 1 a24388 1 ‘show debug aix-thread’ d24391 2 a24392 2 ‘set debug amd-dbgapi-lib’ ‘show debug amd-dbgapi-lib’ d24394 2 a24395 2 The ‘set debug amd-dbgapi-lib log-level LEVEL’ command can be used to enable diagnostic messages from the ‘amd-dbgapi’ library, where d24398 1 a24398 1 ‘off’ d24401 1 a24401 1 ‘error’ d24404 1 a24404 1 ‘warning’ d24407 1 a24407 1 ‘info’ d24410 1 a24410 1 ‘verbose’ d24413 1 a24413 1 The ‘show debug amd-dbgapi-lib log-level’ command displays the d24416 2 a24417 2 ‘set debug amd-dbgapi’ ‘show debug amd-dbgapi’ d24419 2 a24420 2 The ‘set debug amd-dbgapi’ command can be used to enable diagnostic messages in the ‘amd-dbgapi’ target. The ‘show debug amd-dbgapi’ d24424 1 a24424 1 ‘set debug check-physname’ d24431 1 a24431 1 ‘show debug check-physname’ d24434 1 a24434 1 ‘set debug coff-pe-read’ d24437 1 a24437 1 ‘show debug coff-pe-read’ d24441 1 a24441 1 ‘set debug dwarf-die’ d24444 1 a24444 1 ‘show debug dwarf-die’ d24447 1 a24447 1 ‘set debug dwarf-line’ d24452 1 a24452 1 ‘show debug dwarf-line’ d24455 1 a24455 1 ‘set debug dwarf-read’ d24460 1 a24460 1 ‘show debug dwarf-read’ d24463 1 a24463 1 ‘set debug displaced’ d24466 1 a24466 1 ‘show debug displaced’ d24470 1 a24470 1 ‘set debug event’ d24473 1 a24473 1 ‘show debug event’ d24476 1 a24476 1 ‘set debug event-loop’ d24478 2 a24479 2 possible values are ‘off’, ‘all’ (shows all debugging info) and ‘all-except-ui’ (shows all debugging info except those about d24481 1 a24481 1 ‘show debug event-loop’ d24485 1 a24485 1 ‘set debug expression’ d24488 1 a24488 1 ‘show debug expression’ d24492 1 a24492 1 ‘set debug fbsd-lwp’ d24495 1 a24495 1 ‘show debug fbsd-lwp’ d24498 1 a24498 1 ‘set debug fbsd-nat’ d24500 1 a24500 1 ‘show debug fbsd-nat’ d24503 1 a24503 1 ‘set debug fortran-array-slicing’ d24507 1 a24507 1 ‘show debug fortran-array-slicing’ d24511 1 a24511 1 ‘set debug frame’ d24514 1 a24514 1 ‘show debug frame’ d24517 1 a24517 1 ‘set debug gnu-nat’ d24519 1 a24519 1 ‘show debug gnu-nat’ d24522 1 a24522 1 ‘set debug infrun’ d24524 1 a24524 1 inferior. The default is off. ‘infrun.c’ contains GDB's runtime d24527 1 a24527 1 ‘show debug infrun’ d24530 1 a24530 1 ‘set debug infcall’ d24533 1 a24533 1 ‘show debug infcall’ d24536 1 a24536 1 ‘set debug jit’ d24538 1 a24538 1 ‘show debug jit’ d24541 1 a24541 1 ‘set debug linux-nat [on|off]’ d24544 1 a24544 1 ‘show debug linux-nat’ d24547 1 a24547 1 ‘set debug linux-namespaces’ d24550 1 a24550 1 ‘show debug linux-namespaces’ d24553 1 a24553 1 ‘set debug mach-o’ d24556 1 a24556 1 ‘show debug mach-o’ d24560 1 a24560 1 ‘set debug notification’ d24563 1 a24563 1 ‘show debug notification’ d24567 1 a24567 1 ‘set debug observer’ d24570 1 a24570 1 ‘show debug observer’ d24573 1 a24573 1 ‘set debug overload’ d24577 1 a24577 1 ‘show debug overload’ d24581 1 a24581 1 ‘set debug parser’ d24583 1 a24583 1 Internally, this sets the ‘yydebug’ variable in the expression d24586 1 a24586 1 ‘show debug parser’ d24589 1 a24589 1 ‘set debug remote’ d24593 1 a24593 1 ‘show debug remote’ d24596 1 a24596 1 ‘set debug remote-packet-max-chars’ d24598 1 a24598 1 packet when ‘set debug remote’ is on. This is useful to prevent d24602 1 a24602 1 The default value is ‘512’, which means GDB will truncate each d24605 1 a24605 1 Setting this option to ‘unlimited’ will disable truncation and will d24607 1 a24607 1 ‘show debug remote-packet-max-chars’ d24610 1 a24610 1 ‘set debug separate-debug-file’ d24613 1 a24613 1 ‘show debug separate-debug-file’ d24616 1 a24616 1 ‘set debug serial’ d24619 1 a24619 1 ‘show debug serial’ d24622 1 a24622 1 ‘set debug solib’ d24625 1 a24625 1 ‘show debug solib’ d24628 1 a24628 1 ‘set debug symbol-lookup’ d24633 1 a24633 1 ‘show debug symbol-lookup’ d24636 1 a24636 1 ‘set debug symfile’ d24639 1 a24639 1 ‘show debug symfile’ d24642 1 a24642 1 ‘set debug symtab-create’ d24647 1 a24647 1 ‘show debug symtab-create’ d24650 1 a24650 1 ‘set debug target’ d24655 1 a24655 1 ‘show debug target’ d24658 1 a24658 1 ‘set debug timestamp’ d24662 1 a24662 1 ‘show debug timestamp’ d24666 1 a24666 1 ‘set debug varobj’ d24669 1 a24669 1 ‘show debug varobj’ d24673 1 a24673 1 ‘set debug xml’ d24675 1 a24675 1 ‘show debug xml’ d24678 1 a24678 1 ‘set debug breakpoints’ d24681 1 a24681 1 ‘show debug breakpoints’ d24691 2 a24692 2 ‘set interactive-mode’ If ‘on’, forces GDB to assume that GDB was started in a terminal. d24695 2 a24696 2 ‘off’, forces GDB to operate in the opposite mode, and it uses the default answers to all queries. If ‘auto’ (the default), GDB tries d24705 1 a24705 1 ‘show interactive-mode’ d24709 4 a24712 4 ‘set suppress-cli-notifications’ If ‘on’, command-line-interface (CLI) notifications that are printed by GDB are suppressed. If ‘off’, the notifications are printed as usual. The default value is ‘off’. CLI notifications d24763 1 a24763 1 ‘show suppress-cli-notifications’ d24786 1 a24786 1 ‘set script-extension off’ d24789 1 a24789 1 ‘set script-extension soft’ d24795 1 a24795 1 ‘set script-extension strict’ d24800 2 a24801 2 ‘show script-extension’ Display the current value of the ‘script-extension’ option. d24836 2 a24837 2 A “user-defined command” is a sequence of GDB commands to which you assign a new name as a command. This is done with the ‘define’ command. d24840 1 a24840 1 ‘$arg0...$argN’. A trivial example: d24850 1 a24850 1 This defines the command ‘adder’, which prints the sum of its three d24855 1 a24855 1 In addition, ‘$argc’ may be used to find out how many arguments have d24867 1 a24867 1 Combining with the ‘eval’ command (*note eval::) makes it easier to d24880 1 a24880 1 ‘define COMMANDNAME’ d24886 2 a24887 2 example, ‘define target my-target’ creates a user-defined ‘target my-target’ command. d24890 2 a24891 2 lines, which are given following the ‘define’ command. The end of these commands is marked by a line containing ‘end’. d24893 1 a24893 1 ‘document COMMANDNAME’ d24895 1 a24895 1 accessed by ‘help’. The command COMMANDNAME must already be d24897 2 a24898 2 ‘define’ reads the lines of the command definition, ending with ‘end’. After the ‘document’ command is finished, ‘help’ on command d24901 2 a24902 2 You may use the ‘document’ command again to change the documentation of a command. Redefining the command with ‘define’ d24906 1 a24906 1 documentation will then be used by the ‘help’ and ‘apropos’ d24909 1 a24909 1 defining an alias as a set of nested ‘with’ commands (*note Command d24912 1 a24912 1 ‘define-prefix COMMANDNAME’ d24915 1 a24915 1 the ‘define’ command. Note that ‘define-prefix’ can be used with a d24948 1 a24948 1 ‘dont-repeat’ d24953 1 a24953 1 ‘help user-defined’ d24958 2 a24959 2 ‘show user’ ‘show user COMMANDNAME’ d24965 3 a24967 3 ‘show max-user-call-depth’ ‘set max-user-call-depth’ The value of ‘max-user-call-depth’ controls how many recursion d24990 3 a24992 3 You may define “hooks”, which are a special kind of user-defined command. Whenever you run the command ‘foo’, if the user-defined command ‘hook-foo’ exists, it is executed (with no arguments) before d24996 2 a24997 2 executed. Whenever you run the command ‘foo’, if the user-defined command ‘hookpost-foo’ exists, it is executed (with no arguments) after d25005 1 a25005 1 In addition, a pseudo-command, ‘stop’ exists. Defining (‘hook-stop’) d25010 1 a25010 1 For example, to ignore ‘SIGALRM’ signals while single-stepping, but d25025 1 a25025 1 As a further example, to hook at the beginning and end of the ‘echo’ d25044 3 a25046 3 e.g. ‘backtrace’ rather than ‘bt’. You can hook a multi-word command by adding ‘hook-’ or ‘hookpost-’ to the last word of the command, e.g. ‘define target hook-remote’ to add a hook to ‘target remote’. d25053 1 a25053 1 you get a warning from the ‘define’ command. d25062 1 a25062 1 commands. Comments (lines starting with ‘#’) may also be included. An d25066 2 a25067 2 You can request the execution of a command file with the ‘source’ command. Note that the ‘source’ command is also used to evaluate d25069 1 a25069 1 configured using the ‘script-extension’ setting. *Note Extending GDB: d25072 1 a25072 1 ‘source [-s] [-v] FILENAME’ d25084 1 a25084 1 the ‘directory’ command); except that ‘$cdir’ is not searched because d25087 1 a25087 1 If ‘-s’ is specified, then GDB searches for FILENAME on the search d25090 6 a25095 6 if FILENAME is ‘mylib/myscript’ and the search path contains ‘/home/user’ then GDB will look for the script ‘/home/user/mylib/myscript’. The search is also done if FILENAME is an absolute path. For example, if FILENAME is ‘/tmp/myscript’ and the search path contains ‘/home/user’ then GDB will look for the script ‘/home/user/tmp/myscript’. For DOS-like systems, if FILENAME contains a d25097 2 a25098 2 if FILENAME is ‘d:myscript’ and the search path contains ‘c:/tmp’ then GDB will look for the script ‘c:/tmp/myscript’. d25100 1 a25100 1 If ‘-v’, for verbose mode, is given then GDB displays each command as d25118 2 a25119 2 example will execute commands from the file ‘cmds’. All output and errors would be directed to ‘log’. d25129 2 a25130 2 ‘if’ ‘else’ d25132 1 a25132 1 executed commands. The ‘if’ command takes a single argument, which d25135 1 a25135 1 value is nonzero). There can then optionally be an ‘else’ line, d25138 1 a25138 1 containing ‘end’. d25140 2 a25141 2 ‘while’ This command allows to write loops. Its syntax is similar to ‘if’: d25144 2 a25145 2 line, terminated by an ‘end’. These commands are called the “body” of the loop. The commands in the body of ‘while’ are executed d25148 3 a25150 3 ‘loop_break’ This command exits the ‘while’ loop in whose body it is included. Execution of the script continues after that ‘while’s ‘end’ line. d25152 1 a25152 1 ‘loop_continue’ d25154 2 a25155 2 commands in the ‘while’ loop in whose body it is included. Execution branches to the beginning of the ‘while’ loop, where it d25158 3 a25160 3 ‘end’ Terminate the block of commands that are the body of ‘if’, ‘else’, or ‘while’ flow-control commands. d25174 1 a25174 1 ‘echo TEXT’ d25176 1 a25176 1 escape sequences, such as ‘\n’ to print a newline. *No newline is d25181 2 a25182 2 otherwise trimmed from all arguments. To print ‘ and foo = ’, use the command ‘echo \ and foo = \ ’. d25197 1 a25197 1 ‘output EXPRESSION’ d25199 1 a25199 1 newlines, no ‘$NN = ’. The value is not entered in the value d25203 1 a25203 1 ‘output/FMT EXPRESSION’ d25205 1 a25205 1 formats as for ‘print’. *Note Output Formats: Output Formats, for d25208 1 a25208 1 ‘printf TEMPLATE, EXPRESSIONS...’ d25218 2 a25219 2 As in ‘C’ ‘printf’, ordinary characters in TEMPLATE are printed verbatim, while “conversion specification” introduced by the ‘%’ d25229 2 a25230 2 ‘printf’ supports all the standard ‘C’ conversion specifications, including the flags and modifiers between the ‘%’ character and the d25233 1 a25233 1 • The argument-ordering modifiers, such as ‘2$’, are not d25236 1 a25236 1 • The modifier ‘*’ is not supported for specifying precision or d25239 2 a25240 2 • The ‘'’ flag (for separation of digits into groups according to ‘LC_NUMERIC'’) is not supported. d25242 1 a25242 1 • The type modifiers ‘hh’, ‘j’, ‘t’, and ‘z’ are not supported. d25244 1 a25244 1 • The conversion letter ‘n’ (as in ‘%n’) is not supported. d25246 1 a25246 1 • The conversion letters ‘a’ and ‘A’ are not supported. d25248 4 a25251 4 Note that the ‘ll’ type modifier is supported only if the underlying ‘C’ implementation used to build GDB supports the ‘long long int’ type, and the ‘L’ type modifier is supported only if ‘long double’ type is available. d25253 2 a25254 2 As in ‘C’, ‘printf’ supports simple backslash-escape sequences, such as ‘\n’, ‘\t’, ‘\\’, ‘\"’, ‘\a’, and ‘\f’, that consist of d25258 2 a25259 2 Additionally, ‘printf’ supports conversion specifications for DFP (“Decimal Floating Point”) types using the following length d25262 1 a25262 1 • ‘H’ for printing ‘Decimal32’ types. d25264 1 a25264 1 • ‘D’ for printing ‘Decimal64’ types. d25266 1 a25266 1 • ‘DD’ for printing ‘Decimal128’ types. d25268 1 a25268 1 If the underlying ‘C’ implementation used to build GDB has support d25272 1 a25272 1 In case there is no such ‘C’ support, no additional modifiers will d25279 1 a25279 1 Additionally, ‘printf’ supports a special ‘%V’ output format. This d25281 1 a25281 1 GDB would produce with the standard ‘print’ command (*note d25289 2 a25290 2 It is possible to include print options with the ‘%V’ format by placing them in ‘[...]’ immediately after the ‘%V’, like this: d25295 1 a25295 1 If you need to print a literal ‘[’ directly after a ‘%V’, then just d25301 1 a25301 1 ‘eval TEMPLATE, EXPRESSIONS...’ d25311 1 a25311 1 When a new object file is read (for example, due to the ‘file’ command, d25313 1 a25313 1 the command file ‘OBJFILE-gdb.gdb’. *Note Auto-loading extensions::. d25318 1 a25318 1 ‘set auto-load gdb-scripts [on|off]’ d25322 1 a25322 1 ‘show auto-load gdb-scripts’ d25326 1 a25326 1 ‘info auto-load gdb-scripts [REGEXP]’ d25344 1 a25344 1 GDB itself uses aliases. For example ‘s’ is an alias of the ‘step’ d25346 1 a25346 1 commands like ‘set’ and ‘show’. d25349 2 a25350 2 multi-word commands. For example, GDB provides the ‘tty’ alias of the ‘set inferior-tty’ command. d25352 1 a25352 1 You can define a new alias with the ‘alias’ command. d25354 1 a25354 1 ‘alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS]’ d25365 1 a25365 1 The ‘-a’ option specifies that the new alias is an abbreviation of d25368 1 a25368 1 The ‘--’ option specifies the end of options, and is useful when d25375 1 a25375 1 For example, the below defines an alias ‘btfullall’ that shows all d25384 2 a25385 2 ‘disas’, the current shortest unambiguous abbreviation of the ‘disassemble’ command and you wanted an even shorter version named ‘di’. d25392 1 a25392 1 the ‘document’ command. An alias automatically picks up the d25395 2 a25396 2 Here is an example where we make ‘elms’ an abbreviation of ‘elements’ in the ‘set print elements’ command. This is to show that you can make d25405 2 a25406 2 Note that if you are defining an alias of a ‘set’ command, and you want to have an alias for the corresponding ‘show’ command, then you d25415 2 a25416 2 for a more complex command. This creates alias ‘spe’ of the command ‘set print elements’. d25440 1 a25440 1 For example, if you often use the command ‘thread apply all’ d25443 1 a25443 1 the ‘-ascending’ and ‘-c’ options by using: d25448 2 a25449 2 type the ‘thread apply asc-all’ followed by ‘some arguments’, GDB will execute ‘thread apply all -ascending -c some arguments’. d25458 2 a25459 2 For example, you define a new alias ‘bt_ALL’ showing all possible information and another alias ‘bt_SMALL’ showing very limited d25466 1 a25466 1 (For more on using the ‘alias’ command, see *note Aliases::.) d25470 1 a25470 1 as argument. For example, the below defines ‘faalocalsoftype’ that d25480 2 a25481 2 ‘with’ commands to have a particular combination of temporary settings. For example, the below defines the alias ‘pp10’ that pretty prints an d25485 7 a25491 7 This defines the alias ‘pp10’ as being a sequence of 3 commands. The first part ‘with print pretty --’ temporarily activates the setting ‘set print pretty’, then launches the command that follows the separator ‘--’. The command following the first part is also a ‘with’ command that temporarily changes the setting ‘set print elements’ to 10, then launches the command that follows the second separator ‘--’. The third part ‘print’ is the command the ‘pp10’ alias will launch, using the d25493 1 a25493 1 the user. For more information about the ‘with’ command usage, see d25497 1 a25497 1 the aliased command. When the alias is a set of nested commands, ‘help’ d25499 2 a25500 2 not particularly useful for an alias such as ‘pp10’. For such an alias, it is useful to give a specific documentation using the ‘document’ d25517 1 a25517 1 configured using ‘--with-python’. d25520 1 a25520 1 ‘DATA-DIRECTORY/python’, where DATA-DIRECTORY is the data directory as d25522 1 a25522 1 as the “python directory”, is automatically added to the Python Search d25528 2 a25529 2 ‘DATA-DIRECTORY/python/gdb/command’ or ‘DATA-DIRECTORY/python/gdb/function’ directories are automatically d25548 3 a25550 3 ‘python-interactive [COMMAND]’ ‘pi [COMMAND]’ Without an argument, the ‘python-interactive’ command can be used d25552 1 a25552 1 ‘EOF’ character (e.g., ‘Ctrl-D’ on an empty prompt). d25562 3 a25564 3 ‘python [COMMAND]’ ‘py [COMMAND]’ The ‘python’ command can be used to evaluate Python code. d25566 1 a25566 1 If given an argument, the ‘python’ command will evaluate the d25572 3 a25574 3 If you do not provide an argument to ‘python’, it will act as a multi-line command, like ‘define’. In this case, the Python script is made up of subsequent command lines, given after the ‘python’ d25576 1 a25576 1 ‘end’. For example: d25583 1 a25583 1 ‘set python print-stack’ d25586 3 a25588 3 controlled using ‘set python print-stack’: if ‘full’, then full Python stack printing is enabled; if ‘none’, then Python stack and message printing is disabled; if ‘message’, the default, only the d25591 2 a25592 2 ‘set python ignore-environment [on|off]’ By default this option is ‘off’, and, when GDB initializes its d25595 1 a25595 1 example ‘PYTHONHOME’, and ‘PYTHONPATH’(1). d25597 1 a25597 1 If this option is set to ‘on’ before Python is initialized then d25603 1 a25603 1 This option is equivalent to passing ‘-E’ to the real ‘python’ d25606 2 a25607 2 ‘set python dont-write-bytecode [auto|on|off]’ When this option is ‘off’, then, once GDB has initialized the d25609 1 a25609 1 modules that it imports and write the byte code to disk in ‘.pyc’ d25612 1 a25612 1 If this option is set to ‘on’ before Python is initialized then d25618 4 a25621 4 By default this option is set to ‘auto’. In this mode, provided the ‘python ignore-environment’ setting is ‘off’, the environment variable ‘PYTHONDONTWRITEBYTECODE’ is examined to see if it should write out byte-code or not. ‘PYTHONDONTWRITEBYTECODE’ is d25627 1 a25627 1 This option is equivalent to passing ‘-B’ to the real ‘python’ d25633 2 a25634 2 ‘source script-name’ The script name must end with ‘.py’ and GDB must be configured to d25636 1 a25636 1 ‘script-extension’ setting. *Note Extending GDB: Extending GDB. d25640 9 a25648 9 ‘set debug py-breakpoint on|off’ ‘show debug py-breakpoint’ When ‘on’, GDB prints debug messages related to the Python breakpoint API. This is ‘off’ by default. ‘set debug py-unwind on|off’ ‘show debug py-unwind’ When ‘on’, GDB prints debug messages related to the Python unwinder API. This is ‘off’ by default. d25652 1 a25652 1 (1) See the ENVIRONMENT VARIABLES section of ‘man 1 python’ for a d25662 1 a25662 1 command ‘python help (gdb)’. d25667 1 a25667 1 ‘gdb.some_function ('foo', bar = 1, baz = 2)’. d25720 1 a25720 1 At startup, GDB overrides Python's ‘sys.stdout’ and ‘sys.stderr’ to d25723 1 a25723 1 (*note Screen Size::). In this situation, a Python ‘KeyboardInterrupt’ d25729 2 a25730 2 • GDB installs handlers for ‘SIGCHLD’ and ‘SIGINT’. Python code must not override these, or even change the options using ‘sigaction’. d25733 3 a25735 3 common for GUI toolkits to install a ‘SIGCHLD’ handler. When creating a new Python thread, you can use ‘gdb.block_signals’ or ‘gdb.Thread’ to handle this correctly; see *note Threading in d25738 1 a25738 1 • GDB takes care to mark its internal file descriptors as d25745 1 a25745 1 GDB introduces a new Python module, named ‘gdb’. All methods and d25747 2 a25748 2 ‘import’s the ‘gdb’ module for use in all scripts evaluated by the ‘python’ command. d25750 2 a25751 2 Some types of the ‘gdb’ module come with a textual representation (accessible through the ‘repr’ or ‘str’ functions). These are offered d25765 1 a25765 1 defaults to ‘False’. d25769 3 a25771 3 If the TO_STRING parameter is ‘True’, then output will be collected by ‘gdb.execute’ and returned as a string. The default is ‘False’, in which case the return value is ‘None’. If TO_STRING is ‘True’, d25779 1 a25779 1 and earlier, this function returned ‘None’ if there were no d25781 1 a25781 1 ‘gdb.breakpoints’ returns an empty sequence in this case. d25785 2 a25786 2 ‘gdb.Breakpoint’ objects matching function names defined by the REGEX pattern. If the MINSYMS keyword is ‘True’, all system d25791 1 a25791 1 integer value of THROTTLE, a ‘RuntimeError’ will be raised and no d25795 1 a25795 1 iterable that yields a collection of ‘gdb.Symtab’ objects and will d25797 1 a25797 1 ‘gdb.Symtab’ objects. d25802 1 a25802 1 multi-part name. For example, ‘print object’ is a valid parameter d25806 1 a25806 1 ‘gdb.error’ (*note Exception Handling::). Otherwise, the d25811 1 a25811 1 Sets the gdb parameter NAME to VALUE. As with ‘gdb.parameter’, the d25816 1 a25816 1 Create a Python context manager (for use with the Python ‘with’ d25820 1 a25820 1 This uses ‘gdb.parameter’ in its implementation, so it can throw d25836 1 a25836 1 doesn't exist in the value history, a ‘gdb.error’ exception will be d25840 1 a25840 1 of ‘gdb.Value’ (*note Values From Inferior::). d25843 1 a25843 1 Takes VALUE, an instance of ‘gdb.Value’ (*note Values From d25846 3 a25848 3 history number. If VALUE is not a ‘gdb.Value’, it is is converted using the ‘gdb.Value’ constructor. If VALUE can't be converted to a ‘gdb.Value’ then a ‘TypeError’ is raised. d25850 1 a25850 1 When a command implemented in Python prints a single ‘gdb.Value’ as d25861 1 a25861 1 include the ‘$’ that is used to mark a convenience variable in an d25863 1 a25863 1 ‘None’ is returned. d25868 4 a25871 4 include the ‘$’ that is used to mark a convenience variable in an expression. If VALUE is ‘None’, then the convenience variable is removed. Otherwise, if VALUE is not a ‘gdb.Value’ (*note Values From Inferior::), it is is converted using the ‘gdb.Value’ d25877 1 a25877 1 ‘gdb.Value’. d25881 1 a25881 1 ‘False’, meaning that the current frame or current static context d25890 1 a25890 1 Return the ‘gdb.Symtab_and_line’ object corresponding to the PC d25892 2 a25893 2 is passed as an argument, then the ‘symtab’ and ‘line’ attributes of the returned ‘gdb.Symtab_and_line’ object will be ‘None’ and 0 d25895 1 a25895 1 ‘gdb.current_progspace().find_pc_line(pc)’ and is included for d25903 1 a25903 1 ‘gdb.STDOUT’ d25906 1 a25906 1 ‘gdb.STDERR’ d25909 1 a25909 1 ‘gdb.STDLOG’ d25912 1 a25912 1 Writing to ‘sys.stdout’ or ‘sys.stderr’ will automatically call d25923 1 a25923 1 ‘gdb.STDOUT’ d25926 1 a25926 1 ‘gdb.STDERR’ d25929 1 a25929 1 ‘gdb.STDLOG’ d25932 1 a25932 1 Flushing ‘sys.stdout’ or ‘sys.stderr’ will automatically call this d25938 1 a25938 1 ‘gdb.parameter('target-charset')’ in that ‘auto’ is never returned. d25943 1 a25943 1 ‘gdb.parameter('target-wide-charset')’ in that ‘auto’ is never d25949 1 a25949 1 ‘gdb.parameter('host-charset')’ in that ‘auto’ is never returned. d25953 2 a25954 2 a string, or ‘None’. This is identical to ‘gdb.current_progspace().solib_name(address)’ and is included for d25961 1 a25961 1 string holding any unparsed section of EXPRESSION (or ‘None’ if the d25963 2 a25964 2 either ‘None’ or another tuple that contains all the locations that match the expression represented as ‘gdb.Symtab_and_line’ objects d25966 1 a25966 1 is decoded the way that GDB's inbuilt ‘break’ or ‘edit’ commands do d25974 3 a25976 3 The parameter ‘current_prompt’ contains the current GDB prompt. This method must return a Python string, or ‘None’. If a string is returned, the GDB prompt will be set to that string. If ‘None’ is d25987 1 a25987 1 from ‘gdb.Architecture.name’ (*note Architecture.name: d25991 1 a25991 1 Return a list of ‘gdb.TargetConnection’ objects, one for each d25996 1 a25996 1 Return a string in the format ‘ADDR ’, where ADDR is d26004 2 a26005 2 GDB looks back for a suitable symbol can be controlled with ‘set print max-symbolic-offset’ (*note Print Settings::). d26008 1 a26008 1 number information when ‘set print symbol-filename on’ (*note Print d26010 1 a26010 1 ‘ADDR at FILENAME:LINE-NUMBER’. d26031 1 a26031 1 ‘disassemble’. d26041 3 a26043 3 ‘gdb.parameter('language')’, this function will never return ‘auto’. If a ‘gdb.Frame’ object is available (*note Frames In Python::), the ‘language’ method might be preferable in some cases, d26058 1 a26058 1 be delivered to the GDB main thread. The ‘block_signals’ function d26067 2 a26068 2 This is a subclass of Python's ‘threading.Thread’ class. It overrides the ‘start’ method to call ‘block_signals’, making this d26076 1 a26076 1 if a Python command is running, ‘KeyboardInterrupt’ will be raised. d26078 1 a26078 1 Unlike most Python APIs in GDB, ‘interrupt’ is thread-safe. d26084 1 a26084 1 ‘post_event’ will be run in the order in which they were posted; d26088 1 a26088 1 Unlike most Python APIs in GDB, ‘post_event’ is thread-safe. For d26119 1 a26119 1 When executing the ‘python’ command, Python exceptions uncaught within d26121 1 a26121 1 mechanism. If the command that called ‘python’ does not handle the d26123 1 a26123 1 will be printed depends on ‘set python print-stack’ (*note Python d26135 1 a26135 1 ‘gdb.error’ d26137 1 a26137 1 derived from ‘RuntimeError’, for compatibility with earlier d26143 2 a26144 2 ‘gdb.MemoryError’ This is a subclass of ‘gdb.error’ which is thrown when an operation d26147 3 a26149 3 ‘KeyboardInterrupt’ User interrupt (via ‘C-c’ or by typing ‘q’ at a pagination prompt) is translated to a Python ‘KeyboardInterrupt’ exception. d26155 2 a26156 2 When implementing GDB commands in Python via ‘gdb.Command’, or functions via ‘gdb.Function’, it is useful to be able to throw an d26161 1 a26161 1 ‘gdb.GdbError’ d26189 1 a26189 1 type ‘gdb.Value’. GDB uses this object for its internal bookkeeping of d26194 1 a26194 1 example for an integer or floating-point value ‘some_val’: d26198 7 a26204 7 As result of this, ‘bar’ will also be a ‘gdb.Value’ object whose values are of the same type as those of ‘some_val’. Valid Python operations can also be performed on ‘gdb.Value’ objects representing a ‘struct’ or ‘class’ object. For such cases, the overloaded operator (if present), is used to perform the operation. For example, if ‘val1’ and ‘val2’ are ‘gdb.Value’ objects representing instances of a ‘class’ which overloads the ‘+’ operator, then one can use the ‘+’ operator in their Python d26209 2 a26210 2 The result of the operation ‘val3’ is also a ‘gdb.Value’ object corresponding to the value returned by the overloaded ‘+’ operator. In d26212 2 a26213 2 ‘+’ (binary addition), ‘-’ (binary subtraction), ‘*’ (multiplication), ‘/’, ‘%’, ‘<<’, ‘>>’, ‘|’, ‘&’, ‘^’. d26216 3 a26218 3 accessed using the Python “dictionary syntax”. For example, if ‘some_val’ is a ‘gdb.Value’ instance holding a structure, you can access its ‘foo’ element with: d26222 5 a26226 5 Again, ‘bar’ will also be a ‘gdb.Value’ object. Structure elements can also be accessed by using ‘gdb.Field’ objects as subscripts (*note Types In Python::, for more information on ‘gdb.Field’ objects). For example, if ‘foo_field’ is a ‘gdb.Field’ object corresponding to element ‘foo’ of the above structure, then ‘bar’ can also be accessed as d26231 1 a26231 1 If a ‘gdb.Value’ has array or pointer type, an integer index can be d26236 1 a26236 1 A ‘gdb.Value’ that represents a function can be executed via inferior d26241 1 a26241 1 For example, ‘some_val’ is a ‘gdb.Value’ instance representing a d26248 1 a26248 1 ‘gdb.Value’. d26254 2 a26255 2 ‘gdb.Value’ object representing the address. Otherwise, this attribute holds ‘None’. d26263 2 a26264 2 The type of this ‘gdb.Value’. The value of this attribute is a ‘gdb.Type’ object (*note Types In Python::). d26267 1 a26267 1 The dynamic type of this ‘gdb.Value’. This uses the object's d26278 1 a26278 1 just return the static type of the value as in ‘ptype foo’ (*note d26282 2 a26283 2 The value of this read-only boolean attribute is ‘True’ if this ‘gdb.Value’ has not yet been fetched from the inferior. GDB does d26288 2 a26289 2 The value of ‘somevar’ is not fetched at this time. It will be fetched when the value is needed, or when the ‘fetch_lazy’ method d26293 2 a26294 2 The value of this attribute is a ‘bytes’ object containing the bytes that make up this ‘Value’'s complete value in little endian d26299 2 a26300 2 buffer object (e.g. a ‘bytes’ object), the length of the new buffer must exactly match the length of this ‘Value’'s type. The bytes d26303 1 a26303 1 As with ‘Value.assign’ (*note Value.assign::), if this value cannot d26309 1 a26309 1 Many Python values can be converted directly to a ‘gdb.Value’ via d26317 1 a26317 1 A Python integer is converted to the C ‘long’ type for the d26321 1 a26321 1 A Python long is converted to the C ‘long long’ type for the d26325 1 a26325 1 A Python float is converted to the C ‘double’ type for the d26334 2 a26335 2 ‘gdb.Value’ If ‘val’ is a ‘gdb.Value’, then a copy of the value is made. d26337 3 a26339 3 ‘gdb.LazyString’ If ‘val’ is a ‘gdb.LazyString’ (*note Lazy Strings In Python::), then the lazy string's ‘value’ method is called, d26343 2 a26344 2 This second form of the ‘gdb.Value’ constructor returns a ‘gdb.Value’ of type TYPE where the value contents are taken from d26349 1 a26349 1 If TYPE is ‘None’ then this version of ‘__init__’ behaves as though d26353 1 a26353 1 Assign RHS to this value, and return ‘None’. If this value cannot d26358 1 a26358 1 Return a new instance of ‘gdb.Value’ that is the result of casting d26360 1 a26360 1 ‘gdb.Type’ object. If the cast cannot be performed for some d26364 1 a26364 1 For pointer data types, this method returns a new ‘gdb.Value’ d26366 1 a26366 1 example, if ‘foo’ is a C pointer to an ‘int’, declared in your C d26371 1 a26371 1 then you can use the corresponding ‘gdb.Value’ to access what ‘foo’ d26376 2 a26377 2 The result ‘bar’ will be a ‘gdb.Value’ object holding the value pointed to by ‘foo’. d26379 2 a26380 2 A similar function ‘Value.referenced_value’ exists which also returns ‘gdb.Value’ objects corresponding to the values pointed to d26382 5 a26386 5 values). However, the behavior of ‘Value.dereference’ differs from ‘Value.referenced_value’ by the fact that the behavior of ‘Value.dereference’ is identical to applying the C unary operator ‘*’ on a given value. For example, consider a reference to a pointer ‘ptrref’, declared in your C++ program as d26394 6 a26399 6 Though ‘ptrref’ is a reference value, one can apply the method ‘Value.dereference’ to the ‘gdb.Value’ object corresponding to it and obtain a ‘gdb.Value’ which is identical to that corresponding to ‘val’. However, if you apply the method ‘Value.referenced_value’, the result would be a ‘gdb.Value’ object identical to that corresponding to ‘ptr’. d26405 6 a26410 6 The ‘gdb.Value’ object ‘py_val’ is identical to that corresponding to ‘val’, and ‘py_ptr’ is identical to that corresponding to ‘ptr’. In general, ‘Value.dereference’ can be applied whenever the C unary operator ‘*’ can be applied to the corresponding C value. For those cases where applying both ‘Value.dereference’ and ‘Value.referenced_value’ is allowed, the results obtained need not d26412 3 a26414 3 are however identical when applied on ‘gdb.Value’ objects corresponding to pointers (‘gdb.Value’ objects with type code ‘TYPE_CODE_PTR’) in a C/C++ program. d26418 1 a26418 1 ‘gdb.Value’ object corresponding to the value referenced by the d26420 1 a26420 1 ‘Value.dereference’ and ‘Value.referenced_value’ produce identical d26422 2 a26423 2 ‘Value.dereference’ cannot get the values referenced by reference values. For example, consider a reference to an ‘int’, declared in d26429 4 a26432 4 then applying ‘Value.dereference’ to the ‘gdb.Value’ object corresponding to ‘ref’ will result in an error, while applying ‘Value.referenced_value’ will result in a ‘gdb.Value’ object identical to that corresponding to ‘val’. d26438 2 a26439 2 The ‘gdb.Value’ object ‘py_val’ is identical to that corresponding to ‘val’. d26442 1 a26442 1 Return a ‘gdb.Value’ object which is a reference to the value d26446 1 a26446 1 Return a ‘gdb.Value’ object which is a ‘const’ version of the value d26450 1 a26450 1 Like ‘Value.cast’, but works as if the C++ ‘dynamic_cast’ operator d26454 1 a26454 1 Like ‘Value.cast’, but works as if the C++ ‘reinterpret_cast’ d26458 1 a26458 1 Convert a ‘gdb.Value’ to a string, similarly to what the ‘print’ d26460 1 a26460 1 calling the ‘str’ function on the ‘gdb.Value’. The representation d26468 3 a26470 3 ‘raw’ ‘True’ if pretty-printers (*note Pretty Printing::) should not be used to format the value. ‘False’ if enabled d26472 1 a26472 1 ‘gdb.Value’ should be used to format it. d26474 19 a26492 19 ‘pretty_arrays’ ‘True’ if arrays should be pretty printed to be more convenient to read, ‘False’ if they shouldn't (see ‘set print array’ in *note Print Settings::). ‘pretty_structs’ ‘True’ if structs should be pretty printed to be more convenient to read, ‘False’ if they shouldn't (see ‘set print pretty’ in *note Print Settings::). ‘array_indexes’ ‘True’ if array indexes should be included in the string representation of arrays, ‘False’ if they shouldn't (see ‘set print array-indexes’ in *note Print Settings::). ‘symbols’ ‘True’ if the string representation of a pointer should include the corresponding symbol name (if one exists), ‘False’ if it shouldn't (see ‘set print symbol’ in *note Print d26495 13 a26507 13 ‘unions’ ‘True’ if unions which are contained in other structures or unions should be expanded, ‘False’ if they shouldn't (see ‘set print union’ in *note Print Settings::). ‘address’ ‘True’ if the string representation of a pointer should include the address, ‘False’ if it shouldn't (see ‘set print address’ in *note Print Settings::). ‘nibbles’ ‘True’ if binary values should be displayed in groups of four bits, known as nibbles. ‘False’ if it shouldn't (*note set d26510 6 a26515 6 ‘deref_refs’ ‘True’ if C++ references should be resolved to the value they refer to, ‘False’ (the default) if they shouldn't. Note that, unlike for the ‘print’ command, references are not automatically expanded when using the ‘format_string’ method or the ‘str’ function. There is no global ‘print’ setting to d26518 2 a26519 2 ‘actual_objects’ ‘True’ if the representation of a pointer to an object should d26522 2 a26523 2 ‘False’ if the _declared_ type should be used. (See ‘set print object’ in *note Print Settings::). d26525 9 a26533 9 ‘static_members’ ‘True’ if static members should be included in the string representation of a C++ object, ‘False’ if they shouldn't (see ‘set print static-members’ in *note Print Settings::). ‘max_characters’ Number of string characters to print, ‘0’ to follow ‘max_elements’, or ‘UINT_MAX’ to print an unlimited number of characters (see ‘set print characters’ in *note Print d26536 3 a26538 3 ‘max_elements’ Number of array elements to print, or ‘0’ to print an unlimited number of elements (see ‘set print elements’ in d26541 1 a26541 1 ‘max_depth’ d26543 2 a26544 2 ‘-1’ to print an unlimited number of elements (see ‘set print max-depth’ in *note Print Settings::). d26546 1 a26546 1 ‘repeat_threshold’ d26548 2 a26549 2 elements, or ‘0’ to represent all elements, even if repeated. (See ‘set print repeats’ in *note Print Settings::). d26551 1 a26551 1 ‘format’ d26553 2 a26554 2 to use for the returned string. For instance, ‘'x'’ is equivalent to using the GDB command ‘print’ with the ‘/x’ d26557 2 a26558 2 ‘styling’ ‘True’ if GDB should apply styling to the returned string. d26565 1 a26565 1 When ‘False’, which is the default, no output styling is d26568 2 a26569 2 ‘summary’ ‘True’ when just a summary should be printed. In this mode, d26572 1 a26572 1 by ‘set print frame-arguments scalars’ (*note Print d26582 1 a26582 1 If this ‘gdb.Value’ represents a string, then this method converts d26594 2 a26595 2 pointer to or an array of characters or ints of type ‘wchar_t’, ‘char16_t’, or ‘char32_t’. d26598 3 a26600 3 naming the encoding of the string in the ‘gdb.Value’, such as ‘"ascii"’, ‘"iso-8859-6"’ or ‘"utf-8"’. It accepts the same encodings as the corresponding argument to Python's ‘string.decode’ d26603 1 a26603 1 string, then either the ‘target-charset’ (*note Character Sets::) d26608 1 a26608 1 argument to Python's ‘string.decode’ method. d26614 2 a26615 2 If this ‘gdb.Value’ represents a string, then this method converts the contents to a ‘gdb.LazyString’ (*note Lazy Strings In d26619 2 a26620 2 naming the encoding of the ‘gdb.LazyString’. Some examples are: ‘ascii’, ‘iso-8859-6’ or ‘utf-8’. If the ENCODING argument is an d26636 2 a26637 2 If the ‘gdb.Value’ object is currently a lazy value (‘gdb.Value.is_lazy’ is ‘True’), then the value is fetched from the d26641 1 a26641 1 If the ‘gdb.Value’ object is not a lazy value, this method has no d26652 1 a26652 1 GDB represents types from the inferior using the class ‘gdb.Type’. d26654 1 a26654 1 The following type-related functions are available in the ‘gdb’ d26663 1 a26663 1 Ordinarily, this function will return an instance of ‘gdb.Type’. d26667 1 a26667 1 Architectures In Python::, for the ‘integer_type’ method. d26670 3 a26672 3 of that type can be accessed using the Python “dictionary syntax”. For example, if ‘some_type’ is a ‘gdb.Type’ instance holding a structure type, you can access its ‘foo’ field with: d26676 2 a26677 2 ‘bar’ will be a ‘gdb.Field’ object; see below under the description of the ‘Type.fields’ method for a description of the ‘gdb.Field’ class. d26679 1 a26679 1 An instance of ‘Type’ has the following attributes: d26689 1 a26689 1 ‘TYPE_CODE_’ constants defined below. d26693 1 a26693 1 situations, such as Rust ‘enum’ types or Ada variant records, the d26696 1 a26696 1 ‘gdb.lookup_type’ may be dynamic; while the type of the variable's d26705 2 a26706 2 ‘gdb.lookup_symbol("array", ...).type’ could yield a ‘gdb.Type’ which reports a size of ‘None’. This is the dynamic type. d26708 1 a26708 1 However, examining ‘gdb.parse_and_eval("array").type’ would yield a d26712 1 a26712 1 The name of this type. If this type has no name, then ‘None’ is d26716 2 a26717 2 The size of this type, in target ‘char’ units. Usually, a target's ‘char’ type will be an 8-bit byte. However, on some unusual d26720 1 a26720 1 ‘None’. d26724 2 a26725 2 ‘struct’, ‘union’, or ‘enum’ in C and C++; not all languages have this concept. If this type has no tag name, then ‘None’ is d26729 1 a26729 1 The ‘gdb.Objfile’ that this type was defined in, or ‘None’ if there d26733 2 a26734 2 This property is ‘True’ if the type is a scalar type, otherwise, this property is ‘False’. Examples of non-scalar types include d26738 3 a26740 3 For scalar types (those for which ‘Type.is_scalar’ is ‘True’), this property is ‘True’ if the type is signed, otherwise this property is ‘False’. d26743 1 a26743 1 which ‘Type.is_scalar’ is ‘False’), will raise a ‘ValueError’. d26756 1 a26756 1 ‘Type.is_array_like’, this is determined based on the originating d26766 1 a26766 1 • For structure and union types, this method returns the fields. d26768 1 a26768 1 • Enum types have one field per enum constant. d26770 1 a26770 1 • Function and method types have one field per parameter. The d26773 1 a26773 1 • Array types have one field representing the array's range. d26775 2 a26776 2 • If the type does not fit into one of these categories, a ‘TypeError’ is raised. d26778 1 a26778 1 Each field is a ‘gdb.Field’ object, with some pre-defined d26780 2 a26781 2 ‘bitpos’ This attribute is not available for ‘enum’ or ‘static’ (as in d26785 1 a26785 1 this case, the value will be ‘None’. Also, a dynamic type may d26789 2 a26790 2 ‘enumval’ This attribute is only available for ‘enum’ fields, and its d26793 2 a26794 2 ‘name’ The name of the field, or ‘None’ for anonymous fields. d26796 2 a26797 2 ‘artificial’ This is ‘True’ if the field is artificial, usually meaning d26799 1 a26799 1 attribute is always provided, and is ‘False’ if the field is d26802 3 a26804 3 ‘is_base_class’ This is ‘True’ if the field represents a base class of a C++ structure. This attribute is always provided, and is ‘False’ d26806 1 a26806 1 argument of ‘fields’, or if that type was not a C++ class. d26808 1 a26808 1 ‘bitsize’ d26814 3 a26816 3 ‘type’ The type of the field. This is usually an instance of ‘Type’, but it can be ‘None’ in some situations. d26818 1 a26818 1 ‘parent_type’ d26820 1 a26820 1 ‘gdb.Type’. d26823 1 a26823 1 Return a new ‘gdb.Type’ object which represents an array of this d26831 1 a26831 1 Return a new ‘gdb.Type’ object which represents a vector of this d26838 1 a26838 1 The difference between an ‘array’ and a ‘vector’ is that arrays d26844 1 a26844 1 Return a new ‘gdb.Type’ object which represents a ‘const’-qualified d26848 2 a26849 2 Return a new ‘gdb.Type’ object which represents a ‘volatile’-qualified variant of this type. d26852 3 a26854 3 Return a new ‘gdb.Type’ object which represents an unqualified variant of this type. That is, the result is neither ‘const’ nor ‘volatile’. d26857 1 a26857 1 Return a Python ‘Tuple’ object that contains two elements: the low d26859 1 a26859 1 type does not have a range, GDB will raise a ‘gdb.error’ exception d26863 1 a26863 1 Return a new ‘gdb.Type’ object which represents a reference to this d26867 1 a26867 1 Return a new ‘gdb.Type’ object which represents a pointer to this d26871 1 a26871 1 Return a new ‘gdb.Type’ that represents the real type, after d26875 1 a26875 1 Return a new ‘gdb.Type’ object which represents the target type of d26889 2 a26890 2 If this ‘gdb.Type’ is an instantiation of a template, this will return a new ‘gdb.Value’ or ‘gdb.Type’ which represents the value d26893 1 a26893 1 If this ‘gdb.Type’ is not a template type, or if the type has fewer d26901 1 a26901 1 Return ‘gdb.Value’ instance of this type whose value is optimized d26907 1 a26907 1 defined in the ‘gdb’ module: d26909 1 a26909 1 ‘gdb.TYPE_CODE_PTR’ d26912 1 a26912 1 ‘gdb.TYPE_CODE_ARRAY’ d26915 1 a26915 1 ‘gdb.TYPE_CODE_STRUCT’ d26918 1 a26918 1 ‘gdb.TYPE_CODE_UNION’ d26921 1 a26921 1 ‘gdb.TYPE_CODE_ENUM’ d26924 1 a26924 1 ‘gdb.TYPE_CODE_FLAGS’ d26927 1 a26927 1 ‘gdb.TYPE_CODE_FUNC’ d26930 1 a26930 1 ‘gdb.TYPE_CODE_INT’ d26933 1 a26933 1 ‘gdb.TYPE_CODE_FLT’ d26936 2 a26937 2 ‘gdb.TYPE_CODE_VOID’ The special type ‘void’. d26939 1 a26939 1 ‘gdb.TYPE_CODE_SET’ d26942 1 a26942 1 ‘gdb.TYPE_CODE_RANGE’ d26945 1 a26945 1 ‘gdb.TYPE_CODE_STRING’ d26950 1 a26950 1 ‘gdb.TYPE_CODE_BITSTRING’ d26953 1 a26953 1 ‘gdb.TYPE_CODE_ERROR’ d26956 1 a26956 1 ‘gdb.TYPE_CODE_METHOD’ d26959 1 a26959 1 ‘gdb.TYPE_CODE_METHODPTR’ d26962 1 a26962 1 ‘gdb.TYPE_CODE_MEMBERPTR’ d26965 1 a26965 1 ‘gdb.TYPE_CODE_REF’ d26968 1 a26968 1 ‘gdb.TYPE_CODE_RVALUE_REF’ d26971 1 a26971 1 ‘gdb.TYPE_CODE_CHAR’ d26974 1 a26974 1 ‘gdb.TYPE_CODE_BOOL’ d26977 1 a26977 1 ‘gdb.TYPE_CODE_COMPLEX’ d26980 1 a26980 1 ‘gdb.TYPE_CODE_TYPEDEF’ d26983 1 a26983 1 ‘gdb.TYPE_CODE_NAMESPACE’ d26986 1 a26986 1 ‘gdb.TYPE_CODE_DECFLOAT’ d26989 1 a26989 1 ‘gdb.TYPE_CODE_INTERNAL_FUNCTION’ d26993 1 a26993 1 ‘gdb.TYPE_CODE_XMETHOD’ d26997 1 a26997 1 ‘gdb.TYPE_CODE_FIXED_POINT’ d27000 1 a27000 1 ‘gdb.TYPE_CODE_NAMESPACE’ d27003 1 a27003 1 Further support for types is provided in the ‘gdb.types’ Python d27020 1 a27020 1 To allow extensibility, GDB provides the ‘gdb.ValuePrinter’ base d27025 1 a27025 1 pretty-printer protocol, and ‘gdb.ValuePrinter’-based printers are d27043 1 a27043 1 For efficiency, the ‘children’ method should lazily compute its d27046 1 a27046 1 ‘-var-list-children’ (*note GDB/MI Variable Objects::) limit the d27049 2 a27050 2 Children may be hidden from display based on the value of ‘set print max-depth’ (*note Print Settings::). d27055 1 a27055 1 consumer as a ‘displayhint’ attribute of the variable being d27059 1 a27059 1 method must return a string or the special value ‘None’. d27063 1 a27063 1 ‘array’ d27065 2 a27066 2 CLI uses this to respect parameters such as ‘set print elements’ and ‘set print array’. d27068 1 a27068 1 ‘map’ d27073 1 a27073 1 ‘string’ d27075 1 a27075 1 the printer's ‘to_string’ method returns a Python string of d27079 1 a27079 1 characters, respecting ‘set print elements’, and the like. d27081 1 a27081 1 The special value ‘None’ causes GDB to apply the default display d27090 2 a27091 2 When printing from the CLI, if the ‘to_string’ method exists, then GDB will prepend its result to the values returned by ‘children’. d27095 2 a27096 2 the result of ‘to_string’ in a stack trace, omitting the result of ‘children’. d27100 1 a27100 1 Otherwise, if this method returns an instance of ‘gdb.Value’, then d27105 1 a27105 1 to a ‘gdb.Value’, then GDB performs the conversion and prints the d27108 1 a27108 1 and strings are convertible to ‘gdb.Value’; other types are not. d27110 1 a27110 1 Finally, if this method returns ‘None’ then no further operations d27117 1 a27117 1 objects derived from ‘gdb.ValuePrinter’. d27120 1 a27120 1 ‘None’ may be returned if the number can't readily be computed. d27124 1 a27124 1 objects derived from ‘gdb.ValuePrinter’. d27131 1 a27131 1 pretty-printer for a ‘gdb.Value’: d27134 1 a27134 1 This function takes a ‘gdb.Value’ object as an argument. If a d27136 1 a27136 1 such printer exists, then this returns ‘None’. d27139 2 a27140 2 (including temporarily applied settings, such as ‘/x’) simply by calling ‘Value.format_string’ (*note Values From Inferior::). However, these d27145 2 a27146 2 given to ‘Value.format_string’, and whose values are the user's settings. During a ‘print’ or other operation, the values will d27165 1 a27165 1 The Python list ‘gdb.pretty_printers’ contains an array of d27168 1 a27168 1 ‘global’ printers, they're available when debugging all inferiors. d27170 2 a27171 2 Each ‘gdb.Progspace’ contains a ‘pretty_printers’ attribute. Each ‘gdb.Objfile’ also contains a ‘pretty_printers’ attribute. d27173 1 a27173 1 Each function on these lists is passed a single ‘gdb.Value’ argument d27176 1 a27176 1 create a pretty-printer for the value, it should return ‘None’. d27178 3 a27180 3 GDB first checks the ‘pretty_printers’ attribute of each ‘gdb.Objfile’ in the current program space and iteratively calls each enabled lookup routine in the list for that ‘gdb.Objfile’ until it d27185 1 a27185 1 ‘gdb.pretty_printers’ list, again calling each enabled function until an d27199 1 a27199 1 For example, if ‘print frame-arguments’ is on, a backtrace can become d27202 1 a27202 1 Pretty-printers are enabled and disabled by attaching an ‘enabled’ d27204 1 a27204 1 attribute is present and its value is ‘False’, the printer is disabled, d27216 1 a27216 1 Here is an example showing how a ‘std::string’ printer might be d27218 1 a27218 1 must provide. Note that this example uses the ‘gdb.ValuePrinter’ base d27248 1 a27248 1 returns ‘None’. d27259 1 a27259 1 An ideal auto-load file will consist solely of ‘import’s of your printer d27272 2 a27273 2 To continue the ‘std::string’ example (*note Pretty Printing API::), this code might appear in ‘gdb.libstdcxx.v6’: d27294 1 a27294 1 types, then its “subprinters” are the printers for the individual data d27297 1 a27297 1 The ‘gdb.printing’ module provides a formal way of solving these d27329 1 a27329 1 ‘gdb.printing’ module. Instead a function is provided to build up the d27350 1 a27350 1 corresponding output of ‘info pretty-printer’: d27367 1 a27367 1 A “type printer” is just a Python object conforming to a certain d27373 2 a27374 2 otherwise. This is manipulated by the ‘enable type-printer’ and ‘disable type-printer’ commands. d27378 1 a27378 1 by the ‘enable type-printer’ and ‘disable type-printer’ commands. d27383 1 a27383 1 new object that supplies a ‘recognize’ method, as described below. d27385 1 a27385 1 When displaying a type, say via the ‘ptype’ command, GDB will compute d27391 2 a27392 2 GDB will call the ‘instantiate’ method of each enabled type printer. If this method returns ‘None’, then the result is ignored; otherwise, it d27397 1 a27397 1 stopping if the function returns a non-‘None’ value. The recognition d27401 1 a27401 1 If TYPE is not recognized, return ‘None’. Otherwise, return a d27403 1 a27403 1 argument will be an instance of ‘gdb.Type’ (*note Types In d27426 3 a27428 3 ‘backtrace’ (*note The backtrace command: backtrace-command.), ‘-stack-list-frames’ (*note The -stack-list-frames command: -stack-list-frames.), ‘-stack-list-variables’ (*note The d27430 2 a27431 2 ‘-stack-list-arguments’ *note The -stack-list-arguments command: -stack-list-arguments.) and ‘-stack-list-locals’ (*note The d27438 1 a27438 1 utilize tools such as the Python's ‘itertools’ module to work with and d27461 1 a27461 1 The Python dictionary ‘gdb.frame_filters’ contains key/object d27463 1 a27463 1 are called ‘global’ frame filters, and they are available when debugging d27465 1 a27465 1 directly. In addition to the ‘global’ dictionary, there are other d27468 3 a27470 3 dictionaries can be found are: ‘gdb.Progspace’ which contains a ‘frame_filters’ dictionary attribute, and each ‘gdb.Objfile’ object which also contains a ‘frame_filters’ dictionary attribute. d27473 2 a27474 2 filters, GDB combines the ‘global’, ‘gdb.Progspace’ and all ‘gdb.Objfile’ dictionaries currently loaded. All of the ‘gdb.Objfile’ d27477 2 a27478 2 ‘enabled’ attribute is ‘False’. This pruned list is then sorted according to the ‘priority’ attribute in each filter. d27481 1 a27481 1 iterator which wraps each frame in the call stack in a ‘FrameDecorator’ d27505 2 a27506 2 Note that the output from ‘Filter3’ is passed to the input of ‘Filter2’, and so on. d27508 2 a27509 2 This ‘filter’ method is passed a Python iterator. This iterator contains a sequence of frame decorators that wrap each ‘gdb.Frame’, d27512 1 a27512 1 receive an iterator entirely comprised of default ‘FrameDecorator’ d27529 1 a27529 1 The ‘name’ attribute must be Python string which contains the name d27536 1 a27536 1 The ‘enabled’ attribute must be Python boolean. This attribute d27538 2 a27539 2 considered when frame filters are executed. If ‘enabled’ is ‘True’, then the frame filter will be executed when any of the d27541 1 a27541 1 If ‘enabled’ is ‘False’, then the frame filter will not be d27545 1 a27545 1 The ‘priority’ attribute must be Python integer. This attribute d27547 2 a27548 2 There are no imposed limits on the range of ‘priority’ other than it must be a valid integer. The higher the ‘priority’ attribute, d27550 1 a27550 1 frame filters. Although ‘priority’ can be negative, it is d27567 1 a27567 1 of each ‘gdb.Frame’ in commands where frame filters are executed. This d27569 2 a27570 2 ‘gdb.Frame’ with Python code contained within each API call. This separates the actual data contained in a ‘gdb.Frame’ from the decorated d27572 1 a27572 1 maintain integrity of the data contained in each ‘gdb.Frame’. d27576 1 a27576 1 GDB already contains a frame decorator called ‘FrameDecorator’. This d27578 1 a27578 1 of a ‘gdb.Frame’. It is recommended that other frame decorators inherit d27581 2 a27582 2 ‘FrameDecorator’ is defined in the Python module ‘gdb.FrameDecorator’, so your code can import it like: d27587 1 a27587 1 The ‘elided’ method groups frames together in a hierarchical d27594 1 a27594 1 The ‘elided’ function must return an iterable and this iterable d27597 3 a27599 3 return an empty iterable, or ‘None’. Elided frames are indented from normal frames in a ‘CLI’ backtrace, or in the case of GDB/MI, are placed in the ‘children’ field of the eliding frame. d27611 1 a27611 1 ‘None’. d27613 1 a27613 1 If this function returns ‘None’, GDB will not print any data for d27621 1 a27621 1 size to describe the address of the frame, or ‘None’. d27623 1 a27623 1 If this function returns a ‘None’, GDB will not print any data for d27632 1 a27632 1 the path to the object file backing the frame, or ‘None’. d27634 1 a27634 1 If this function returns a ‘None’, GDB will not print any data for d27642 1 a27642 1 This method must return a Python integer type, or ‘None’. d27644 1 a27644 1 If this function returns a ‘None’, GDB will not print any data for d27649 2 a27650 2 This method must return an iterable, or ‘None’. Returning an empty iterable, or ‘None’ means frame arguments will not be printed for d27654 2 a27655 2 This object must implement a ‘symbol’ method which takes a single ‘self’ parameter and must return a ‘gdb.Symbol’ (*note Symbols In d27657 5 a27661 5 ‘value’ method which takes a single ‘self’ parameter and must return a ‘gdb.Value’ (*note Values From Inferior::), a Python value, or ‘None’. If the ‘value’ method returns ‘None’, and the ‘argument’ method returns a ‘gdb.Symbol’, GDB will look-up and print the value of the ‘gdb.Symbol’ automatically. d27701 2 a27702 2 This method must return an iterable or ‘None’. Returning an empty iterable, or ‘None’ means frame local arguments will not be printed d27707 1 a27707 1 described in the ‘frame_args’ function, (*note The frame filter d27734 1 a27734 1 This method must return the underlying ‘gdb.Frame’ that this frame d27785 2 a27786 2 the comments the filter assigns the following attributes: ‘name’, ‘priority’ and whether the filter should be enabled with the ‘enabled’ d27792 2 a27793 2 ‘gdb.frame_filters’. As noted earlier, ‘gdb.frame_filters’ is a dictionary that is initialized in the ‘gdb’ module when GDB starts. d27796 1 a27796 1 registered either in the ‘objfile’ or ‘progspace’ dictionaries as they d27810 1 a27810 1 the same as frame filter's ‘name’ attribute. When a user manages frame d27812 1 a27812 1 are those contained in the ‘name’ attribute. d27814 2 a27815 2 The final step of this example is the implementation of the ‘filter’ method. As shown in the example comments, we define the ‘filter’ method d27819 1 a27819 1 valid operation for frame filters that have the ‘enabled’ attribute set, d27829 1 a27829 1 decorator to all frames with the Python ‘itertools imap’ method, the d27871 2 a27872 2 that the ‘filter’ method applies a frame decorator object called ‘InlinedFrameDecorator’ to each element in the iterator. The ‘imap’ d27893 2 a27894 2 This frame decorator only defines and overrides the ‘function’ method. It lets the supplied ‘FrameDecorator’, which is shipped with d27908 1 a27908 1 ‘function’ callback. Using a strategy like this is a way to defer d27916 1 a27916 1 want to hierarchically represent frames, the ‘elided’ frame decorator d27919 1 a27919 1 This example approaches the issue with the ‘elided’ method. This d27940 1 a27940 1 (‘frame_iter’) with a custom iterator called ‘ElidingInlineIterator’. d27967 2 a27968 2 ‘next’ function is called (when GDB prints each frame), the iterator checks if this frame decorator, ‘frame’, is wrapping an inlined frame. d27971 1 a27971 1 contained within the next oldest frame, ‘eliding_frame’, which it d27973 1 a27973 1 ‘ElidingFrameDecorator’, which contains both the elided frame, and the d27987 1 a27987 1 frame in the ‘elided’ method. As before it lets ‘FrameDecorator’ do the d27995 3 a27997 3 In that output, ‘max’ which has been inlined into ‘main’ is printed hierarchically. Another approach would be to combine the ‘function’ method, and the ‘elided’ method to both print a marker in the inlined d28022 4 a28025 4 two attributes, ‘name’ and ‘enabled’, with obvious meanings, and a single method ‘__call__’, which examines a given frame and returns an object (an instance of ‘gdb.UnwindInfo class)’ describing it. If an unwinder does not recognize a frame, it should return ‘None’. The code d28039 1 a28039 1 An object passed to an unwinder (a ‘gdb.PendingFrame’ instance) provides d28044 1 a28044 1 ‘gdb.Value’ object. For a description of the acceptable values of d28049 1 a28049 1 Note that this method will always return a ‘gdb.Value’ for a valid d28053 1 a28053 1 ‘gdb.Value’ returned from this method will be lazy; that is, its d28058 1 a28058 1 The type of the returned ‘gdb.Value’ depends on the register and d28060 1 a28060 1 type, like ‘long long’; but many other types are possible, such as d28063 1 a28063 1 It also provides a factory method to create a ‘gdb.UnwindInfo’ d28067 1 a28067 1 Returns a new ‘gdb.UnwindInfo’ instance identified by given d28072 1 a28072 1 ‘sp, pc’ d28083 1 a28083 1 ‘sp, pc, special’ d28091 1 a28091 1 ‘sp’ d28097 1 a28097 1 Each attribute value should either be an instance of ‘gdb.Value’ or d28100 1 a28100 1 A helper class is provided in the ‘gdb.unwinder’ module that can be d28104 2 a28105 2 Return the ‘gdb.Architecture’ (*note Architectures In Python::) for this ‘gdb.PendingFrame’. This represents the architecture of the d28113 1 a28113 1 Returns the function name of this pending frame, or ‘None’ if it d28117 1 a28117 1 Returns true if the ‘gdb.PendingFrame’ object is valid, false if d28121 1 a28121 1 All ‘gdb.PendingFrame’ methods, except this one, will raise an d28132 1 a28132 1 raise a ‘RuntimeError’ exception. d28148 2 a28149 2 Use ‘PendingFrame.create_unwind_info’ method described above to create a ‘gdb.UnwindInfo’ instance. Use the following method to specify caller d28156 1 a28156 1 ‘gdb.Value’ object). d28158 1 a28158 1 The ‘gdb.unwinder’ Module d28161 1 a28161 1 GDB comes with a ‘gdb.unwinder’ module which contains the following d28165 1 a28165 1 The ‘Unwinder’ class is a base class from which user created d28168 1 a28168 1 the required ‘name’ and ‘enabled’ attributes. d28179 2 a28180 2 A modifiable attribute containing a boolean; when ‘True’, the unwinder is enabled, and will be used by GDB. When ‘False’, d28185 1 a28185 1 calling ‘gdb.PendingFrame.create_unwind_info’. It is not required d28190 1 a28190 1 ‘gdb.unwinder.FrameId’ has the following method: d28192 2 a28193 1 -- Function: gdb.unwinder.FrameId.__init__(sp, pc, special = None) d28195 1 a28195 1 ‘gdb.Value’ object, or an integer. d28198 1 a28198 1 ‘gdb.Value’ object, or an integer. d28200 1 a28200 1 ‘gdb.unwinder.FrameId’ has the following read-only attributes: d28209 1 a28209 1 The SPECIAL value passed to the constructor, or ‘None’ if no d28218 1 a28218 1 The ‘gdb.unwinders’ module provides the function to register an d28225 1 a28225 1 program space (*note Progspaces In Python::), or ‘None’, in which d28230 1 a28230 1 exception unless REPLACE is ‘True’, in which case the old unwinder d28274 1 a28274 1 ‘info unwinder [ LOCUS [ NAME-REGEXP ] ]’ d28279 1 a28279 1 The LOCUS argument should be either ‘global’, ‘progspace’, or the d28286 2 a28287 2 ‘disable unwinder [ LOCUS [ NAME-REGEXP ] ]’ The LOCUS and NAME-REGEXP are interpreted as in ‘info unwinder’ d28289 4 a28292 4 matching unwinders are disabled. The ‘enabled’ field of each matching unwinder is set to ‘False’. ‘enable unwinder [ LOCUS [ NAME-REGEXP ] ]’ The LOCUS and NAME-REGEXP are interpreted as in ‘info unwinder’ d28294 2 a28295 2 matching unwinders are enabled. The ‘enabled’ field of each matching unwinder is set to ‘True’. d28303 1 a28303 1 “Xmethods” are additional methods or replacements for existing methods d28317 1 a28317 1 “xmethod matcher” and an “xmethod worker”. To implement an xmethod, one d28320 1 a28320 1 instance of the method). Internally, GDB invokes the ‘match’ method of d28322 1 a28322 1 ‘match’ method returns a list of matching _worker_ objects. Each worker d28324 1 a28324 1 They implement a ‘get_arg_types’ method which returns a sequence of d28336 1 a28336 1 ‘__call__’ method of the worker object. d28359 2 a28360 2 ‘XMethodMatcher’ defined in the module ‘gdb.xmethod’, or an object with similar interface and attributes. An instance of ‘XMethodMatcher’ has d28372 2 a28373 2 list is an instance of the class ‘XMethod’ defined in the module ‘gdb.xmethod’, or any object with the following attributes: d28375 1 a28375 1 ‘name’ d28379 1 a28379 1 ‘enabled’ d28383 1 a28383 1 The class ‘XMethod’ is a convenience class with same attributes as d28389 1 a28389 1 The ‘XMethodMatcher’ class has the following methods: d28393 1 a28393 1 ‘methods’ attribute is initialized to ‘None’. d28399 2 a28400 2 ‘gdb.Type’ object, and METHOD_NAME is a string value. If the matcher manages named methods as listed in its ‘methods’ attribute, d28402 1 a28402 1 ‘methods’ list are enabled should be returned. d28405 1 a28405 1 ‘XMethodWorker’ defined in the module ‘gdb.xmethod’, or support the d28409 1 a28409 1 This method returns a sequence of ‘gdb.Type’ objects corresponding d28411 2 a28412 2 sequence or ‘None’ if the xmethod does not take any arguments. If the xmethod takes a single argument, then a single ‘gdb.Type’ d28416 1 a28416 1 This method returns a ‘gdb.Type’ object representing the type of d28418 1 a28418 1 tuple of arguments that would be passed to the ‘__call__’ method of d28425 1 a28425 1 the ‘this’ pointer value. d28428 1 a28428 1 using the following function defined in the module ‘gdb.xmethod’: d28431 5 a28435 5 The ‘matcher’ is registered with ‘locus’, replacing an existing matcher with the same name as ‘matcher’ if ‘replace’ is ‘True’. ‘locus’ can be a ‘gdb.Objfile’ object (*note Objfiles In Python::), or a ‘gdb.Progspace’ object (*note Progspaces In Python::), or ‘None’. If it is ‘None’, then ‘matcher’ is registered globally. d28465 4 a28468 4 Let us define two xmethods for the class ‘MyClass’, one replacing the method ‘geta’, and another adding an overloaded flavor of ‘operator+’ which takes a ‘MyClass’ argument (the C++ code above already has an overloaded ‘operator+’ which takes an ‘int’ argument). The xmethod d28507 5 a28511 5 Notice that the ‘match’ method of ‘MyClassMatcher’ returns a worker object of type ‘MyClassWorker_geta’ for the ‘geta’ method, and a worker object of type ‘MyClassWorker_plus’ for the ‘operator+’ method. This is done indirectly via helper classes derived from ‘gdb.xmethod.XMethod’. One does not need to use the ‘methods’ attribute in a matcher as it is d28513 1 a28513 1 good practice to list the xmethods in the ‘methods’ attribute of the d28515 2 a28516 2 xmethods via the ‘enable/disable’ commands. Notice also that a worker object is returned only if the corresponding entry in the ‘methods’ d28549 1 a28549 1 If an object ‘obj’ of type ‘MyClass’ is initialized in C++ code as d28555 2 a28556 2 workers into GDB, invoking the method ‘geta’ or using the operator ‘+’ on ‘obj’ will invoke the xmethods defined above: d28584 1 a28584 1 replacement for the ‘footprint’ method. The full code listing of the d28613 1 a28613 1 Notice that, in this example, we have not used the ‘methods’ d28627 1 a28627 1 of the ‘gdb.Inferior’ class. d28629 1 a28629 1 The following inferior-related functions are available in the ‘gdb’ d28638 1 a28638 1 A ‘gdb.Inferior’ object has the following attributes: d28646 2 a28647 2 The ‘gdb.TargetConnection’ for this inferior (*note Connections In Python::), or ‘None’ if this inferior has no connection. d28653 2 a28654 2 ‘gdb.Inferior.connection.num’ in the case where ‘gdb.Inferior.connection’ is not ‘None’. d28667 1 a28667 1 ‘None’. d28674 1 a28674 1 to the ‘set args’ and ‘show args’ commands. *Note Arguments::. d28678 1 a28678 1 If there are no arguments, the value is ‘None’. d28685 1 a28685 1 A ‘gdb.Inferior’ object has the following methods: d28688 3 a28690 3 Returns ‘True’ if the ‘gdb.Inferior’ object is valid, ‘False’ if not. A ‘gdb.Inferior’ object will become invalid if the inferior no longer exists within GDB. All other ‘gdb.Inferior’ methods will d28700 1 a28700 1 Return the ‘gdb.Architecture’ (*note Architectures In Python::) for d28708 1 a28708 1 ADDRESS. Returns a ‘memoryview’ object, which behaves much like an d28710 1 a28710 1 ‘Inferior.write_memory’ function. d28716 1 a28716 1 from ‘Inferior.read_memory’. If given, LENGTH determines the d28724 2 a28725 2 ‘gdb.read_memory’. Returns a Python ‘Long’ containing the address where the pattern was found, or ‘None’ if the pattern could not be d28730 1 a28730 1 specific data structure such as ‘pthread_t’ for pthreads library d28733 2 a28734 2 The function ‘Inferior.thread_from_thread_handle’ provides the same functionality, but use of ‘Inferior.thread_from_thread_handle’ is d28753 1 a28753 1 One may add arbitrary attributes to ‘gdb.Inferior’ objects in the d28799 1 a28799 1 An “event” is just an object that describes some state change. The d28804 2 a28805 2 handler with an “event registry”. An event registry is an object in the ‘gdb.events’ module which dispatches particular events. A registry d28827 4 a28830 4 In the above example we connect our handler ‘exit_handler’ to the registry ‘events.exited’. Once connected, ‘exit_handler’ gets called when the inferior exits. The argument “event” in this example is of type ‘gdb.ExitedEvent’. As you can see in the example the ‘ExitedEvent’ d28835 1 a28835 1 ‘gdb.ThreadEvent’. This event is a base class and is never emitted d28838 1 a28838 1 ‘gdb.BreakpointEvent’ and ‘gdb.ContinueEvent’. ‘gdb.ThreadEvent’ holds d28844 1 a28844 1 to ‘None’. d28849 2 a28850 2 ‘events.cont’ Emits ‘gdb.ContinueEvent’, which extends ‘gdb.ThreadEvent’. This d28852 1 a28852 1 For inherited attribute refer to ‘gdb.ThreadEvent’ above. d28854 3 a28856 3 ‘events.exited’ Emits ‘events.ExitedEvent’, which indicates that the inferior has exited. ‘events.ExitedEvent’ has two attributes: d28865 1 a28865 1 A reference to the inferior which triggered the ‘exited’ d28868 2 a28869 2 ‘events.stop’ Emits ‘gdb.StopEvent’, which extends ‘gdb.ThreadEvent’. d28872 3 a28874 3 this registry extend ‘gdb.StopEvent’. As a child of ‘gdb.ThreadEvent’, ‘gdb.StopEvent’ will indicate the stopped thread when GDB is running in non-stop mode. Refer to ‘gdb.ThreadEvent’ d28877 1 a28877 1 ‘gdb.StopEvent’ has the following additional attributes: d28889 1 a28889 1 When a ‘StopEvent’ results from a ‘finish’ command, it will d28891 3 a28893 3 available. This will be an entry named ‘return-value’ in the ‘details’ dictionary. The value of this entry will be a ‘gdb.Value’ object. d28895 1 a28895 1 Emits ‘gdb.SignalEvent’, which extends ‘gdb.StopEvent’. d28898 1 a28898 1 received a signal. ‘gdb.SignalEvent’ has the following attributes: d28903 1 a28903 1 command ‘info signals’ in the GDB command prompt. d28905 1 a28905 1 Also emits ‘gdb.BreakpointEvent’, which extends ‘gdb.StopEvent’. d28907 1 a28907 1 ‘gdb.BreakpointEvent’ event indicates that one or more breakpoints d28912 2 a28913 2 ‘gdb.Breakpoint’) that were hit. *Note Breakpoints In Python::, for details of the ‘gdb.Breakpoint’ object. d28918 1 a28918 1 deprecated in favor of the ‘gdb.BreakpointEvent.breakpoints’ d28921 3 a28923 3 ‘events.new_objfile’ Emits ‘gdb.NewObjFileEvent’ which indicates that a new object file has been loaded by GDB. ‘gdb.NewObjFileEvent’ has one attribute: d28926 1 a28926 1 A reference to the object file (‘gdb.Objfile’) which has been d28928 1 a28928 1 ‘gdb.Objfile’ object. d28930 2 a28931 2 ‘events.free_objfile’ Emits ‘gdb.FreeObjFileEvent’ which indicates that an object file is d28933 1 a28933 1 the inferior calls ‘dlclose’. ‘gdb.FreeObjFileEvent’ has one d28937 1 a28937 1 A reference to the object file (‘gdb.Objfile’) which will be d28939 1 a28939 1 ‘gdb.Objfile’ object. d28941 2 a28942 2 ‘events.clear_objfiles’ Emits ‘gdb.ClearObjFilesEvent’ which indicates that the list of d28944 1 a28944 1 ‘gdb.ClearObjFilesEvent’ has one attribute: d28947 1 a28947 1 A reference to the program space (‘gdb.Progspace’) whose d28950 1 a28950 1 ‘events.inferior_call’ d28953 2 a28954 2 type ‘gdb.InferiorCallPreEvent’, and after an inferior call, this emits an event of type ‘gdb.InferiorCallPostEvent’. d28956 1 a28956 1 ‘gdb.InferiorCallPreEvent’ d28966 1 a28966 1 ‘gdb.InferiorCallPostEvent’ d28976 2 a28977 2 ‘events.memory_changed’ Emits ‘gdb.MemoryChangedEvent’ which indicates that the memory of d28979 1 a28979 1 command like ‘set *addr = value’. The event has the following d28988 2 a28989 2 ‘events.register_changed’ Emits ‘gdb.RegisterChangedEvent’ which indicates that a register in d28998 1 a28998 1 ‘events.breakpoint_created’ d29000 1 a29000 1 argument that is passed is the new ‘gdb.Breakpoint’ object. d29002 1 a29002 1 ‘events.breakpoint_modified’ d29004 1 a29004 1 The argument that is passed is the new ‘gdb.Breakpoint’ object. d29006 1 a29006 1 ‘events.breakpoint_deleted’ d29008 3 a29010 3 that is passed is the ‘gdb.Breakpoint’ object. When this event is emitted, the ‘gdb.Breakpoint’ object will already be in its invalid state; that is, the ‘is_valid’ method will return ‘False’. d29012 1 a29012 1 ‘events.before_prompt’ d29016 1 a29016 1 ‘events.new_inferior’ d29021 1 a29021 1 The event is of type ‘gdb.NewInferiorEvent’. This has a single d29025 1 a29025 1 The new inferior, a ‘gdb.Inferior’ object. d29027 1 a29027 1 ‘events.inferior_deleted’ d29030 1 a29030 1 itself is removed, say via ‘remove-inferiors’. d29032 1 a29032 1 The event is of type ‘gdb.InferiorDeletedEvent’. This has a single d29036 1 a29036 1 The inferior that is being removed, a ‘gdb.Inferior’ object. d29038 1 a29038 1 ‘events.new_thread’ d29040 1 a29040 1 type ‘gdb.NewThreadEvent’, which extends ‘gdb.ThreadEvent’. This d29046 1 a29046 1 ‘events.thread_exited’ d29048 1 a29048 1 of type ‘gdb.ThreadExitedEvent’ which extends ‘gdb.ThreadEvent’. d29054 1 a29054 1 ‘events.gdb_exiting’ d29057 1 a29057 1 signal. The event is of type ‘gdb.GdbExitingEvent’, which has a d29063 1 a29063 1 ‘events.connection_removed’ d29065 1 a29065 1 Python::). The event is of type ‘gdb.ConnectionEvent’. This has a d29069 1 a29069 1 The ‘gdb.TargetConnection’ that is being removed. d29071 3 a29073 3 ‘events.executable_changed’ Emits ‘gdb.ExecutableChangedEvent’ which indicates that the ‘gdb.Progspace.executable_filename’ has changed. d29076 1 a29076 1 ‘gdb.Progspace.executable_filename ’ has changed to name a d29078 1 a29078 1 ‘gdb.Progspace.executable_filename’ has changed on disk, and GDB d29082 1 a29082 1 The ‘gdb.Progspace’ in which the current executable has d29084 1 a29084 1 visible in ‘gdb.Progspace.executable_filename’ (*note d29087 2 a29088 2 This attribute will be ‘True’ if the value of ‘gdb.Progspace.executable_filename’ didn't change, but the d29091 2 a29092 2 When this attribute is ‘False’, the value in ‘gdb.Progspace.executable_filename’ was changed to name a d29097 2 a29098 2 ‘gdb.Progspace.executable_filename’ and ‘gdb.Progspace.filename’ respectively. When using the ‘file’ command, GDB updates both of d29103 1 a29103 1 ‘events.new_progspace’ d29106 1 a29106 1 ‘gdb.NewProgspaceEvent’, and has a single read-only attribute: d29109 1 a29109 1 The ‘gdb.Progspace’ that was added to GDB. d29111 1 a29111 1 No ‘NewProgspaceEvent’ is emitted for the very first program space, d29115 1 a29115 1 ‘events.free_progspace’ d29118 1 a29118 1 of the ‘remove-inferiors’ command (*note ‘remove-inferiors’: d29120 1 a29120 1 ‘gdb.FreeProgspaceEvent’, and has a single read-only attribute: d29123 1 a29123 1 The ‘gdb.Progspace’ that is about to be removed from GDB. d29132 1 a29132 1 threads controlled by GDB, via objects of the ‘gdb.InferiorThread’ d29135 1 a29135 1 The following thread-related functions are available in the ‘gdb’ d29140 1 a29140 1 If there is no selected thread, this will return ‘None’. d29143 1 a29143 1 ‘Inferior.threads()’ method. *Note Inferiors In Python::. d29145 1 a29145 1 A ‘gdb.InferiorThread’ object has the following attributes: d29148 2 a29149 2 The name of the thread. If the user specified a name using ‘thread name’, then this returns that name. Otherwise, if an OS-supplied d29151 1 a29151 1 ‘None’. d29154 1 a29154 1 object, which sets the new name, or ‘None’, which removes any d29175 3 a29177 3 ‘InferiorThread.ptid’. This is the string that GDB uses in the ‘Target Id’ column in the ‘info threads’ output (*note ‘info threads’: info_threads.). d29181 1 a29181 1 as a ‘gdb.Inferior’ object. This attribute is not writable. d29187 1 a29187 1 ‘None’. d29190 3 a29192 3 of exiting will return the string ‘Exiting’. For remote targets the ‘details’ string will be obtained with the ‘qThreadExtraInfo’ remote packet, if the target supports it (*note ‘qThreadExtraInfo’: d29195 2 a29196 2 GDB displays the ‘details’ string as part of the ‘Target Id’ column, in the ‘info threads’ output (*note ‘info threads’: d29199 1 a29199 1 A ‘gdb.InferiorThread’ object has the following methods: d29202 2 a29203 2 Returns ‘True’ if the ‘gdb.InferiorThread’ object is valid, ‘False’ if not. A ‘gdb.InferiorThread’ object will become invalid if the d29205 1 a29205 1 All other ‘gdb.InferiorThread’ methods will throw an exception if d29222 5 a29226 5 Return the thread object's handle, represented as a Python ‘bytes’ object. A ‘gdb.Value’ representation of the handle may be constructed via ‘gdb.Value(bufobj, type)’ where BUFOBJ is the Python ‘bytes’ representation of the handle and TYPE is a ‘gdb.Type’ for the handle type. d29228 1 a29228 1 One may add arbitrary attributes to ‘gdb.InferiorThread’ objects in d29267 1 a29267 1 Replay::) are available in the ‘gdb’ module: d29273 1 a29273 1 ‘gdb.Record’ object on success. Throw an exception on failure. d29277 2 a29278 2 • ‘"full"’ • ‘"btrace"’: Possible values for FORMAT: ‘"pt"’, ‘"bts"’ or d29282 2 a29283 2 Access a currently running recording. Return a ‘gdb.Record’ object on success. Return ‘None’ if no recording is currently active. d29290 1 a29290 1 A ‘gdb.Record’ object has the following attributes: d29293 2 a29294 2 A string with the current recording method, e.g. ‘full’ or ‘btrace’. d29297 2 a29298 2 A string with the current recording format, e.g. ‘bt’, ‘pts’ or ‘None’. d29310 1 a29310 1 is no replay active, this will be ‘None’. d29318 1 a29318 1 A ‘gdb.Record’ object has the following methods: d29323 1 a29323 1 The common ‘gdb.Instruction’ class that recording method specific d29330 1 a29330 1 A ‘memoryview’ object holding the raw instruction data. d29338 1 a29338 1 Additionally ‘gdb.RecordInstruction’ has the following attributes: d29341 2 a29342 2 An integer identifying this instruction. ‘number’ corresponds to the numbers seen in ‘record instruction-history’ (*note Process d29346 2 a29347 2 A ‘gdb.Symtab_and_line’ object representing the associated symtab and line of this instruction. May be ‘None’ if no debug d29355 1 a29355 1 error is represented by a ‘gdb.RecordGap’ object in the instruction d29359 2 a29360 2 An integer identifying this gap. ‘number’ corresponds to the numbers seen in ‘record instruction-history’ (*note Process Record d29370 1 a29370 1 A ‘gdb.RecordFunctionSegment’ object has the following attributes: d29373 2 a29374 2 An integer identifying this function segment. ‘number’ corresponds to the numbers seen in ‘record function-call-history’ (*note d29378 2 a29379 2 A ‘gdb.Symbol’ object representing the associated symbol. May be ‘None’ if no debug information is available. d29383 1 a29383 1 ‘None’ if the function call is a gap. d29386 1 a29386 1 A list of ‘gdb.RecordInstruction’ or ‘gdb.RecordGap’ objects d29390 1 a29390 1 A ‘gdb.RecordFunctionSegment’ object representing the caller's d29393 1 a29393 1 nor the return have been recorded, this will be ‘None’. d29396 2 a29397 2 A ‘gdb.RecordFunctionSegment’ object representing the previous segment of this function call. May be ‘None’. d29400 2 a29401 2 A ‘gdb.RecordFunctionSegment’ object representing the next segment of this function call. May be ‘None’. d29473 1 a29473 1 implemented using an instance of the ‘gdb.Command’ class, most commonly d29478 1 a29478 1 The object initializer for ‘Command’ registers the new command with d29480 1 a29480 1 ‘__init__’ method. d29489 1 a29489 1 COMMAND_CLASS should be one of the ‘COMMAND_’ constants defined d29494 1 a29494 1 one of the ‘COMPLETE_’ constants defined below. This argument d29496 1 a29496 1 given, GDB will attempt to complete using the object's ‘complete’ d29500 1 a29500 1 PREFIX is an optional argument. If ‘True’, then the new command is d29511 1 a29511 1 by invoking the ‘dont_repeat’ method at some point in its ‘invoke’ d29513 1 a29513 1 similar to the user command ‘dont-repeat’, see *note dont-repeat: d29526 1 a29526 1 If this method throws an exception, it is turned into a GDB ‘error’ d29530 2 a29531 2 ‘gdb.string_to_argv’. This function behaves identically to GDB's internal argument lexer ‘buildargv’. It is recommended to use this d29542 1 a29542 1 the ‘complete’ command (*note complete: Help.). d29549 3 a29551 3 The ‘complete’ method can return several values: • If the return value is a sequence, the contents of the sequence are used as the completions. It is up to ‘complete’ d29557 1 a29557 1 • If the return value is one of the ‘COMPLETE_’ constants d29561 1 a29561 1 • All other results are treated as though there were no d29569 1 a29569 1 defined in the ‘gdb’ module: d29571 1 a29571 1 ‘gdb.COMMAND_NONE’ d29575 1 a29575 1 ‘gdb.COMMAND_RUNNING’ d29577 2 a29578 2 ‘start’, ‘step’, and ‘continue’ are in this category. Type ‘help running’ at the GDB prompt to see a list of commands in this d29581 3 a29583 3 ‘gdb.COMMAND_DATA’ The command is related to data or variables. For example, ‘call’, ‘find’, and ‘print’ are in this category. Type ‘help data’ at the d29586 1 a29586 1 ‘gdb.COMMAND_STACK’ d29588 2 a29589 2 ‘backtrace’, ‘frame’, and ‘return’ are in this category. Type ‘help stack’ at the GDB prompt to see a list of commands in this d29592 3 a29594 3 ‘gdb.COMMAND_FILES’ This class is used for file-related commands. For example, ‘file’, ‘list’ and ‘section’ are in this category. Type ‘help files’ at d29597 1 a29597 1 ‘gdb.COMMAND_SUPPORT’ d29600 2 a29601 2 not related to the state of the inferior. For example, ‘help’, ‘make’, and ‘shell’ are in this category. Type ‘help support’ at d29604 4 a29607 4 ‘gdb.COMMAND_STATUS’ The command is an ‘info’-related command, that is, related to the state of GDB itself. For example, ‘info’, ‘macro’, and ‘show’ are in this category. Type ‘help status’ at the GDB prompt to see a d29610 4 a29613 4 ‘gdb.COMMAND_BREAKPOINTS’ The command has to do with breakpoints. For example, ‘break’, ‘clear’, and ‘delete’ are in this category. Type ‘help breakpoints’ at the GDB prompt to see a list of commands in this d29616 4 a29619 4 ‘gdb.COMMAND_TRACEPOINTS’ The command has to do with tracepoints. For example, ‘trace’, ‘actions’, and ‘tfind’ are in this category. Type ‘help tracepoints’ at the GDB prompt to see a list of commands in this d29622 1 a29622 1 ‘gdb.COMMAND_TUI’ d29624 1 a29624 1 Type ‘help tui’ at the GDB prompt to see a list of commands in this d29627 1 a29627 1 ‘gdb.COMMAND_USER’ d29629 2 a29630 2 typically does not fit in one of the other categories. Type ‘help user-defined’ at the GDB prompt to see a list of commands in this d29633 1 a29633 1 ‘gdb.COMMAND_OBSCURE’ d29635 2 a29636 2 general interest to users. For example, ‘checkpoint’, ‘fork’, and ‘stop’ are in this category. Type ‘help obscure’ at the GDB prompt d29639 4 a29642 4 ‘gdb.COMMAND_MAINTENANCE’ The command is only useful to GDB maintainers. The ‘maintenance’ and ‘flushregs’ commands are in this category. Type ‘help internals’ at the GDB prompt to see a list of commands in this d29647 2 a29648 2 the ‘complete’ method. These predefined completion constants are all defined in the ‘gdb’ module: d29650 1 a29650 1 ‘gdb.COMPLETE_NONE’ d29653 1 a29653 1 ‘gdb.COMPLETE_FILENAME’ d29656 1 a29656 1 ‘gdb.COMPLETE_LOCATION’ d29660 1 a29660 1 ‘gdb.COMPLETE_COMMAND’ d29664 1 a29664 1 ‘gdb.COMPLETE_SYMBOL’ d29668 1 a29668 1 ‘gdb.COMPLETE_EXPRESSION’ d29689 1 a29689 1 is read into GDB, you may need to import the ‘gdb’ module explicitly. d29699 1 a29699 1 ‘gdb.MICommand’ class, most commonly using a subclass. d29702 1 a29702 1 The object initializer for ‘MICommand’ registers the new command d29704 1 a29704 1 own ‘__init__’ method. d29707 1 a29707 1 GDB/MI command, and in particular must start with a hyphen (‘-’). d29709 1 a29709 1 ‘RuntimeError’ will be raised. Using the name of an GDB/MI command d29716 3 a29718 3 ARGUMENTS is a list of strings. Note, that ‘--thread’ and ‘--frame’ arguments are handled by GDB itself therefore they do not show up in ‘arguments’. d29721 1 a29721 1 ‘^error’ response. Only ‘gdb.GdbError’ exceptions (or its d29723 1 a29723 1 other exception type is treated as a failure of the ‘invoke’ d29725 2 a29726 2 according to the ‘set python print-stack’ setting (*note ‘set python print-stack’: set_python_print_stack.). d29728 2 a29729 2 If this method returns ‘None’, then the GDB/MI command will return a ‘^done’ response with no additional values. d29738 1 a29738 1 • If the value is Python sequence or iterator, it is converted d29741 1 a29741 1 • If the value is Python dictionary, it is converted to GDB/MI d29746 2 a29747 2 • Otherwise, value is first converted to a Python string using ‘str ()’ and then converted to GDB/MI CONST. d29751 1 a29751 1 character long, the first character must be in the set ‘[a-zA-Z]’, d29753 1 a29753 1 ‘[-_a-zA-Z0-9]’. d29755 1 a29755 1 An instance of ‘MICommand’ has the following attributes: d29759 1 a29759 1 ‘__init__’ method. This attribute is read-only. d29765 1 a29765 1 will be ‘True’. d29769 1 a29769 1 be ‘False’. d29771 1 a29771 1 This attribute is read-write, setting this attribute to ‘False’ d29773 1 a29773 1 commands. Setting this attribute to ‘True’ will install the d29802 2 a29803 2 three new GDB/MI commands ‘-echo-dict’, ‘-echo-list’, and ‘-echo-string’. Each time a subclass of ‘gdb.MICommand’ is d29807 1 a29807 1 import the ‘gdb’ module explicitly. d29825 1 a29825 1 string. This is done with the ‘gdb.execute_mi’ function. d29856 1 a29856 1 ‘gdb.notify_mi’ function to do that. d29861 1 a29861 1 (‘-’). DATA is any additional data to be emitted with the d29867 1 a29867 1 If DATA is ‘None’ then no additional values are emitted. d29870 2 a29871 2 Records::) with ‘gdb.notify_mi’ is allowed, users are encouraged to prefix user-defined notification with a hyphen (‘-’) to avoid possible d29874 1 a29874 1 Here is how to emit ‘=-connection-removed’ whenever a connection to d29896 1 a29896 1 implemented as an instance of the ‘gdb.Parameter’ class. d29898 1 a29898 1 Parameters are exposed to the user via the ‘set’ and ‘show’ commands. d29902 1 a29902 1 Two examples are: ‘set follow fork’ and ‘set charset’. Setting these d29909 1 a29909 1 The object initializer for ‘Parameter’ registers the new parameter d29911 1 a29911 1 own ‘__init__’ method. d29915 2 a29916 2 parameters. An example of this can be illustrated with the ‘set print’ set of parameters. If NAME is ‘print foo’, then ‘print’ d29918 1 a29918 1 parameter can subsequently be accessed in GDB as ‘set print foo’. d29923 1 a29923 1 COMMAND_CLASS should be one of the ‘COMMAND_’ constants (*note CLI d29927 1 a29927 1 PARAMETER_CLASS should be one of the ‘PARAM_’ constants defined d29931 1 a29931 1 If PARAMETER_CLASS is ‘PARAM_ENUM’, then ENUM_SEQUENCE must be a d29935 1 a29935 1 If PARAMETER_CLASS is not ‘PARAM_ENUM’, then the presence of a d29942 1 a29942 1 ‘help set’ and ‘help show’ commands, and should be written taking d29947 1 a29947 1 as the first part of the help text for this parameter's ‘set’ d29951 1 a29951 1 The value of ‘set_doc’ should give a brief summary specific to the d29953 1 a29953 1 ‘help set’ command for this parameter. The class documentation d29955 2 a29956 2 does, this text is displayed for both the ‘help set’ and ‘help show’ commands. d29958 1 a29958 1 The ‘set_doc’ value is examined when ‘Parameter.__init__’ is d29963 1 a29963 1 as the first part of the help text for this parameter's ‘show’ d29967 1 a29967 1 The value of ‘show_doc’ should give a brief summary specific to the d29969 1 a29969 1 ‘help show’ command for this parameter. The class documentation d29971 2 a29972 2 does, this text is displayed for both the ‘help set’ and ‘help show’ commands. d29974 1 a29974 1 The ‘show_doc’ value is examined when ‘Parameter.__init__’ is d29978 1 a29978 1 The ‘value’ attribute holds the underlying value of the parameter. d29982 1 a29982 1 There are two methods that may be implemented in any ‘Parameter’ d29987 2 a29988 2 has been changed via the ‘set’ API (for example, ‘set foo off’). The ‘value’ attribute has already been populated with the new value d29992 1 a29992 1 If this method raises the ‘gdb.GdbError’ exception (*note Exception d29994 1 a29994 1 ‘set’ command will fail. Note, however, that the ‘value’ attribute d30016 2 a30017 2 GDB will call this method when a PARAMETER's ‘show’ API has been invoked (for example, ‘show foo’). The argument ‘svalue’ receives d30022 1 a30022 1 available types are represented by constants defined in the ‘gdb’ d30025 3 a30027 3 ‘gdb.PARAM_BOOLEAN’ The value is a plain boolean. The Python boolean values, ‘True’ and ‘False’ are the only valid values. d30029 2 a30030 2 ‘gdb.PARAM_AUTO_BOOLEAN’ The value has three possible states: true, false, and ‘auto’. In d30032 1 a30032 1 ‘auto’ is represented using ‘None’. d30034 3 a30036 3 ‘gdb.PARAM_UINTEGER’ The value is an unsigned integer. The value of ‘None’ should be interpreted to mean "unlimited" (literal ‘'unlimited'’ can also be d30040 3 a30042 3 ‘gdb.PARAM_INTEGER’ The value is a signed integer. The value of ‘None’ should be interpreted to mean "unlimited" (literal ‘'unlimited'’ can also be d30046 1 a30046 1 ‘gdb.PARAM_STRING’ d30048 1 a30048 1 escape sequences, such as ‘\t’, ‘\f’, and octal escapes, are d30052 1 a30052 1 ‘gdb.PARAM_STRING_NOESCAPE’ d30056 2 a30057 2 ‘gdb.PARAM_OPTIONAL_FILENAME’ The value is a either a filename (a string), or ‘None’. d30059 1 a30059 1 ‘gdb.PARAM_FILENAME’ d30061 1 a30061 1 ‘PARAM_STRING_NOESCAPE’, but uses file names for completion. d30063 12 a30074 12 ‘gdb.PARAM_ZINTEGER’ The value is a signed integer. This is like ‘PARAM_INTEGER’, except that 0 is allowed and the value of ‘None’ is not supported. ‘gdb.PARAM_ZUINTEGER’ The value is an unsigned integer. This is like ‘PARAM_UINTEGER’, except that 0 is allowed and the value of ‘None’ is not supported. ‘gdb.PARAM_ZUINTEGER_UNLIMITED’ The value is a signed integer. This is like ‘PARAM_INTEGER’ including that the value of ‘None’ should be interpreted to mean "unlimited" (literal ‘'unlimited'’ can also be used to set that d30079 1 a30079 1 ‘gdb.PARAM_ENUM’ d30091 1 a30091 1 class ‘gdb.Function’. d30094 1 a30094 1 The initializer for ‘Function’ registers the new function with GDB. d30097 1 a30097 1 type ‘internal function’, whose name is the same as the given NAME. d30104 2 a30105 2 converted to instances of ‘gdb.Value’, and then the function's ‘invoke’ method is called. Note that GDB does not predetermine the d30107 1 a30107 1 are passed to ‘invoke’, following the standard Python calling d30113 1 a30113 1 is converted to a ‘gdb.Value’ following the usual rules. d30132 1 a30132 1 is read into GDB, you may need to import the ‘gdb’ module explicitly. d30145 1 a30145 1 A program space, or “progspace”, represents a symbolic view of an d30150 1 a30150 1 The following progspace-related functions are available in the ‘gdb’ d30156 1 a30156 1 identical to ‘gdb.selected_inferior().progspace’ (*note Inferiors d30162 1 a30162 1 Each progspace is represented by an instance of the ‘gdb.Progspace’ d30168 1 a30168 1 argument to the ‘symbol-file’ or ‘file’ commands. d30171 1 a30171 1 attribute will be ‘None’. d30174 3 a30176 3 The ‘gdb.Objfile’ representing the main symbol file (from which debug symbols have been loaded) for the ‘gdb.Progspace’. This is the symbol file set by the ‘symbol-file’ or ‘file’ commands. d30178 2 a30179 2 This will be the ‘gdb.Objfile’ representing ‘Progspace.filename’ when ‘Progspace.filename’ is not ‘None’. d30182 1 a30182 1 attribute will be ‘None’. d30184 3 a30186 3 If the ‘Progspace’ is invalid, i.e., when ‘Progspace.is_valid()’ returns ‘False’, then attempting to access this attribute will raise a ‘RuntimeError’ exception. d30192 2 a30193 2 The file name within this attribute is updated by the ‘exec-file’ and ‘file’ commands. d30195 2 a30196 2 If no executable is currently set within this ‘Progspace’ then this attribute contains ‘None’. d30198 3 a30200 3 If the ‘Progspace’ is invalid, i.e., when ‘Progspace.is_valid()’ returns ‘False’, then attempting to access this attribute will raise a ‘RuntimeError’ exception. d30203 3 a30205 3 The ‘pretty_printers’ attribute is a list of functions. It is used to look up pretty-printers. A ‘Value’ is passed to each function in order; if the function returns ‘None’, then the search d30211 1 a30211 1 The ‘type_printers’ attribute is a list of type printer objects. d30215 1 a30215 1 The ‘frame_filters’ attribute is a dictionary of frame filter d30219 1 a30219 1 The ‘missing_debug_handlers’ attribute is a list of the missing d30226 1 a30226 1 Return the innermost ‘gdb.Block’ containing the given PC value. If d30228 1 a30228 1 will return ‘None’. d30231 1 a30231 1 Return the ‘gdb.Symtab_and_line’ object corresponding to the PC d30233 2 a30234 2 is passed as an argument, then the ‘symtab’ and ‘line’ attributes of the returned ‘gdb.Symtab_and_line’ object will be ‘None’ and 0 d30238 2 a30239 2 Returns ‘True’ if the ‘gdb.Progspace’ object is valid, ‘False’ if not. A ‘gdb.Progspace’ object can become invalid if the program d30241 1 a30241 1 other ‘gdb.Progspace’ methods will throw an exception if it is d30250 1 a30250 1 a string, or ‘None’. d30253 1 a30253 1 Return the ‘gdb.Objfile’ holding the given address, or ‘None’ if no d30256 1 a30256 1 One may add arbitrary attributes to ‘gdb.Progspace’ objects in the d30310 1 a30310 1 “objfiles”. d30312 1 a30312 1 The following objfile-related functions are available in the ‘gdb’ d30319 1 a30319 1 objfile, this function returns ‘None’. d30325 1 a30325 1 ‘gdb.selected_inferior().progspace.objfiles()’ and is included for d30331 1 a30331 1 objfile is not found throw the Python ‘ValueError’ exception. d30335 3 a30337 3 ‘gcc/expr.c’, then it will match source file name of ‘/build/trunk/gcc/expr.c’, but not ‘/build/trunk/libcpp/expr.c’ or ‘/build/trunk/gcc/x-expr.c’. d30339 1 a30339 1 If BY_BUILD_ID is provided and is ‘True’ then NAME is the build ID d30343 1 a30343 1 about this feature, see the description of the ‘--build-id’ d30346 1 a30346 1 Each objfile is represented by an instance of the ‘gdb.Objfile’ d30353 2 a30354 2 The value is ‘None’ if the objfile is no longer valid. See the ‘gdb.Objfile.is_valid’ method, described below. d30359 2 a30360 2 The value is ‘None’ if the objfile is no longer valid. See the ‘gdb.Objfile.is_valid’ method, described below. d30365 1 a30365 1 ‘True’ for file-backed objfiles, and ‘False’ for other kinds. d30369 3 a30371 3 ‘gdb.Objfile’ object that debug info is being provided for. Otherwise this is ‘None’. Separate debug info objfiles are added with the ‘gdb.Objfile.add_separate_debug_file’ method, described d30376 1 a30376 1 have a build ID then the value is ‘None’. d30381 1 a30381 1 ‘--build-id’ command-line option in *note Command Line Options: d30385 1 a30385 1 The containing program space of the objfile as a ‘gdb.Progspace’ d30389 3 a30391 3 The ‘pretty_printers’ attribute is a list of functions. It is used to look up pretty-printers. A ‘Value’ is passed to each function in order; if the function returns ‘None’, then the search d30397 1 a30397 1 The ‘type_printers’ attribute is a list of type printer objects. d30401 1 a30401 1 The ‘frame_filters’ attribute is a dictionary of frame filter d30404 1 a30404 1 One may add arbitrary attributes to ‘gdb.Objfile’ objects in the d30426 1 a30426 1 A ‘gdb.Objfile’ object has the following methods: d30429 2 a30430 2 Returns ‘True’ if the ‘gdb.Objfile’ object is valid, ‘False’ if not. A ‘gdb.Objfile’ object can become invalid if the object file d30432 1 a30432 1 ‘gdb.Objfile’ methods will throw an exception if it is invalid at d30447 1 a30447 1 DOMAIN argument must be a domain constant defined in the ‘gdb’ d30449 1 a30449 1 is similar to ‘gdb.lookup_global_symbol’, except that the search is d30452 1 a30452 1 The result is a ‘gdb.Symbol’ object or ‘None’ if the symbol is not d30456 1 a30456 1 Like ‘Objfile.lookup_global_symbol’, but searches for a global d30466 2 a30467 2 (*note Stack frames: Frames.). The ‘gdb.Frame’ class represents a frame in the stack. A ‘gdb.Frame’ object is only valid while its d30469 1 a30469 1 an invalid frame object, GDB will throw a ‘gdb.error’ exception (*note d30472 1 a30472 1 Two ‘gdb.Frame’ objects can be compared for equality with the ‘==’ d30478 1 a30478 1 The following frame-related functions are available in the ‘gdb’ d30491 1 a30491 1 ‘unwind_stop_reason’ method further down in this section). d30500 1 a30500 1 A ‘gdb.Frame’ object has the following methods: d30503 1 a30503 1 Returns true if the ‘gdb.Frame’ object is valid, false if not. A d30505 1 a30505 1 exist anymore in the inferior. All ‘gdb.Frame’ methods will throw d30509 1 a30509 1 Returns the function name of the frame, or ‘None’ if it can't be d30513 1 a30513 1 Returns the ‘gdb.Architecture’ object corresponding to the frame's d30518 1 a30518 1 ‘gdb.NORMAL_FRAME’ d30521 1 a30521 1 ‘gdb.DUMMY_FRAME’ d30525 1 a30525 1 ‘gdb.INLINE_FRAME’ d30527 1 a30527 1 inlined into a ‘gdb.NORMAL_FRAME’ that is older than this one. d30529 1 a30529 1 ‘gdb.TAILCALL_FRAME’ d30532 1 a30532 1 ‘gdb.SIGTRAMP_FRAME’ d30536 1 a30536 1 ‘gdb.ARCH_FRAME’ d30539 2 a30540 2 ‘gdb.SENTINEL_FRAME’ This is like ‘gdb.NORMAL_FRAME’, but it is only used for the d30546 1 a30546 1 ‘gdb.frame_stop_reason_string’ to convert the value returned by d30549 1 a30549 1 ‘gdb.FRAME_UNWIND_NO_REASON’ d30552 1 a30552 1 ‘gdb.FRAME_UNWIND_NULL_ID’ d30557 1 a30557 1 ‘gdb.FRAME_UNWIND_OUTERMOST’ d30560 1 a30560 1 ‘gdb.FRAME_UNWIND_UNAVAILABLE’ d30564 1 a30564 1 ‘gdb.FRAME_UNWIND_INNER_ID’ d30569 1 a30569 1 ‘gdb.FRAME_UNWIND_SAME_ID’ d30576 1 a30576 1 ‘gdb.FRAME_UNWIND_NO_SAVED_PC’ d30580 1 a30580 1 ‘gdb.FRAME_UNWIND_MEMORY_ERROR’ d30584 1 a30584 1 ‘gdb.FRAME_UNWIND_FIRST_ERROR’ d30610 1 a30610 1 frame, return ‘None’. d30614 1 a30614 1 frame, return ‘None’. d30621 1 a30621 1 Return the value of REGISTER in this frame. Returns a ‘Gdb.Value’ d30624 3 a30626 3 1. A string that is the name of a valid register (e.g., ‘'sp'’ or ‘'rax'’). 2. A ‘gdb.RegisterDescriptor’ object (*note Registers In d30633 1 a30633 1 usually found in the corresponding ‘PLATFORM-tdep.h’ file in d30638 1 a30638 1 looking up and caching a ‘gdb.RegisterDescriptor’ object. d30645 2 a30646 2 argument must be a string or a ‘gdb.Symbol’ object; BLOCK must be a ‘gdb.Block’ object. d30659 1 a30659 1 If there is no static link, this method returns ‘None’. d30676 1 a30676 1 represented individually in Python as a ‘gdb.Block’. Blocks rely on d30682 1 a30682 1 The outermost block is known as the “global block”. The global block d30685 1 a30685 1 The block nested just inside the global block is the “static block”. d30720 1 a30720 1 A ‘gdb.Block’ is iterable. The iterator returns the symbols (*note d30724 2 a30725 2 across blocks in a symbol table. You can also use Python's “dictionary syntax” to access variables in this block, e.g.: d30729 1 a30729 1 The following block-related functions are available in the ‘gdb’ d30733 1 a30733 1 Return the innermost ‘gdb.Block’ containing the given PC value. If d30735 2 a30736 2 will return ‘None’. This is identical to ‘gdb.current_progspace().block_for_pc(pc)’ and is included for d30739 1 a30739 1 A ‘gdb.Block’ object has the following methods: d30742 1 a30742 1 Returns ‘True’ if the ‘gdb.Block’ object is valid, ‘False’ if not. d30744 1 a30744 1 exist anymore in the inferior. All other ‘gdb.Block’ methods will d30749 1 a30749 1 A ‘gdb.Block’ object has the following attributes: d30759 2 a30760 2 The name of the block represented as a ‘gdb.Symbol’. If the block is not named, then this attribute holds ‘None’. This attribute is d30770 1 a30770 1 exist, this attribute holds ‘None’. This attribute is not d30782 1 a30782 1 ‘True’ if the ‘gdb.Block’ object is a global block, ‘False’ if not. d30786 1 a30786 1 ‘True’ if the ‘gdb.Block’ object is a static block, ‘False’ if not. d30797 1 a30797 1 represents these symbols in GDB with the ‘gdb.Symbol’ object. d30799 1 a30799 1 The following symbol-related functions are available in the ‘gdb’ d30809 1 a30809 1 BLOCK. The BLOCK argument must be a ‘gdb.Block’ object. If d30812 1 a30812 1 DOMAIN argument must be a domain constant defined in the ‘gdb’ d30816 5 a30820 5 ‘gdb.Symbol’ object or ‘None’ if the symbol is not found. If the symbol is found, the second element is ‘True’ if the symbol is a field of a method's object (e.g., ‘this’ in C++), otherwise it is ‘False’. If the symbol is not found, the second element is ‘False’. d30828 1 a30828 1 DOMAIN argument must be a domain constant defined in the ‘gdb’ d30831 1 a30831 1 The result is a ‘gdb.Symbol’ object or ‘None’ if the symbol is not d30841 1 a30841 1 DOMAIN argument must be a domain constant defined in the ‘gdb’ d30844 1 a30844 1 The result is a ‘gdb.Symbol’ object or ‘None’ if the symbol is not d30849 2 a30850 2 of the function's ‘gdb.Block’ and check that ‘block.addr_class’ is ‘gdb.SYMBOL_LOC_STATIC’. d30861 1 a30861 1 Similar to ‘gdb.lookup_static_symbol’, this function searches for d30868 1 a30868 1 DOMAIN argument must be a domain constant defined in the ‘gdb’ d30871 1 a30871 1 The result is a list of ‘gdb.Symbol’ objects which could be empty d30876 2 a30877 2 of the function's ‘gdb.Block’ and check that ‘block.addr_class’ is ‘gdb.SYMBOL_LOC_STATIC’. d30879 1 a30879 1 A ‘gdb.Symbol’ object has the following attributes: d30882 2 a30883 2 The type of the symbol or ‘None’ if no type is recorded. This attribute is represented as a ‘gdb.Type’ object. *Note Types In d30888 1 a30888 1 represented as a ‘gdb.Symtab’ object. *Note Symbol Tables In d30905 1 a30905 1 either ‘name’ or ‘linkage_name’, depending on whether the user d30911 1 a30911 1 ‘gdb’ module and described later in this chapter. d30914 2 a30915 2 This is ‘True’ if evaluating this symbol's value requires a frame (*note Frames In Python::) and ‘False’ otherwise. Typically, local d30919 1 a30919 1 ‘True’ if the symbol is an argument of a function. d30922 1 a30922 1 ‘True’ if the symbol is a constant. d30925 1 a30925 1 ‘True’ if the symbol is a function or a method. d30928 2 a30929 2 ‘True’ if the symbol is a variable, as opposed to something like a function or type. Note that this also returns ‘False’ for d30932 1 a30932 1 A ‘gdb.Symbol’ object has the following methods: d30935 3 a30937 3 Returns ‘True’ if the ‘gdb.Symbol’ object is valid, ‘False’ if not. A ‘gdb.Symbol’ object can become invalid if the symbol it refers to does not exist in GDB any longer. All other ‘gdb.Symbol’ methods d30942 1 a30942 1 Compute the value of the symbol, as a ‘gdb.Value’. For functions, d30948 2 a30949 2 The available domain categories in ‘gdb.Symbol’ are represented as constants in the ‘gdb’ module: d30951 1 a30951 1 ‘gdb.SYMBOL_UNDEF_DOMAIN’ d30956 1 a30956 1 ‘gdb.SYMBOL_VAR_DOMAIN’ d30959 1 a30959 1 ‘gdb.SYMBOL_FUNCTION_DOMAIN’ d30962 1 a30962 1 ‘gdb.SYMBOL_TYPE_DOMAIN’ d30964 1 a30964 1 tag (the name appearing after a ‘struct’, ‘union’, or ‘enum’ d30968 1 a30968 1 ‘gdb.SYMBOL_STRUCT_DOMAIN’ d30973 2 a30974 2 Here ‘type_one’ will be in ‘SYMBOL_STRUCT_DOMAIN’, but ‘type_two’ will be in ‘SYMBOL_TYPE_DOMAIN’. d30976 1 a30976 1 ‘gdb.SYMBOL_LABEL_DOMAIN’ d30979 1 a30979 1 ‘gdb.SYMBOL_MODULE_DOMAIN’ d30982 1 a30982 1 ‘gdb.SYMBOL_COMMON_BLOCK_DOMAIN’ d30990 3 a30992 3 each named after one of the preceding constants, but with the ‘SEARCH’ prefix replacing the ‘SYMBOL’ prefix; for example, ‘SEARCH_LABEL_DOMAIN’. These may be or'd together to form a search d30997 2 a30998 2 The available address class categories in ‘gdb.Symbol’ are represented as constants in the ‘gdb’ module: d31000 1 a31000 1 ‘gdb.SYMBOL_LOC_UNDEF’ d31004 1 a31004 1 ‘gdb.SYMBOL_LOC_CONST’ d31007 1 a31007 1 ‘gdb.SYMBOL_LOC_STATIC’ d31010 1 a31010 1 ‘gdb.SYMBOL_LOC_REGISTER’ d31013 1 a31013 1 ‘gdb.SYMBOL_LOC_ARG’ d31017 1 a31017 1 ‘gdb.SYMBOL_LOC_REF_ARG’ d31019 1 a31019 1 ‘LOC_ARG’ except that the value's address is stored at the offset, d31022 2 a31023 2 ‘gdb.SYMBOL_LOC_REGPARM_ADDR’ Value is a specified register. Just like ‘LOC_REGISTER’ except the d31027 1 a31027 1 ‘gdb.SYMBOL_LOC_LOCAL’ d31030 2 a31031 2 ‘gdb.SYMBOL_LOC_TYPEDEF’ Value not used. Symbols in the domain ‘SYMBOL_STRUCT_DOMAIN’ all d31034 1 a31034 1 ‘gdb.SYMBOL_LOC_LABEL’ d31037 1 a31037 1 ‘gdb.SYMBOL_LOC_BLOCK’ d31040 1 a31040 1 ‘gdb.SYMBOL_LOC_CONST_BYTES’ d31043 1 a31043 1 ‘gdb.SYMBOL_LOC_UNRESOLVED’ d31048 1 a31048 1 ‘gdb.SYMBOL_LOC_OPTIMIZED_OUT’ d31051 1 a31051 1 ‘gdb.SYMBOL_LOC_COMPUTED’ d31054 1 a31054 1 ‘gdb.SYMBOL_LOC_COMMON_BLOCK’ d31065 3 a31067 3 to Python via two objects: ‘gdb.Symtab_and_line’ and ‘gdb.Symtab’. Symbol table and line data for a frame is returned from the ‘find_sal’ method in ‘gdb.Frame’ object. *Note Frames In Python::. d31072 1 a31072 1 A ‘gdb.Symtab_and_line’ object has the following attributes: d31075 1 a31075 1 The symbol table object (‘gdb.Symtab’) for this frame. This d31090 1 a31090 1 A ‘gdb.Symtab_and_line’ object has the following methods: d31093 2 a31094 2 Returns ‘True’ if the ‘gdb.Symtab_and_line’ object is valid, ‘False’ if not. A ‘gdb.Symtab_and_line’ object can become invalid d31096 1 a31096 1 GDB any longer. All other ‘gdb.Symtab_and_line’ methods will throw d31099 1 a31099 1 A ‘gdb.Symtab’ object has the following attributes: d31112 1 a31112 1 the compiler. If no producer information is available then ‘None’ d31115 1 a31115 1 A ‘gdb.Symtab’ object has the following methods: d31118 3 a31120 3 Returns ‘True’ if the ‘gdb.Symtab’ object is valid, ‘False’ if not. A ‘gdb.Symtab’ object can become invalid if the symbol table it refers to does not exist in GDB any longer. All other ‘gdb.Symtab’ d31148 1 a31148 1 information for a particular symbol table, use the ‘linetable’ function d31151 1 a31151 1 A ‘gdb.LineTable’ is iterable. The iterator returns ‘LineTableEntry’ d31153 1 a31153 1 table entry. ‘LineTableEntry’ objects have the following attributes: d31166 3 a31168 3 receive multiple ‘LineTableEntry’ objects with matching ‘line’ attributes, but with different ‘pc’ attributes. The iterator is sorted in ascending ‘pc’ order. Here is a small example illustrating iterating d31187 1 a31187 1 In addition to being able to iterate over a ‘LineTable’, it also has d31191 1 a31191 1 Return a Python ‘Tuple’ of ‘LineTableEntry’ objects for any entries d31194 1 a31194 1 Python ‘None’ is returned. d31197 3 a31199 3 Return a Python ‘Boolean’ indicating whether there is an entry in the line table for this source line. Return ‘True’ if an entry is found, or ‘False’ if not. d31202 1 a31202 1 Return a Python ‘List’ of the source line numbers in the symbol d31204 2 a31205 2 The contents of the ‘List’ will just be the source line entries represented as Python ‘Long’ values. d31213 1 a31213 1 Python code can manipulate breakpoints via the ‘gdb.Breakpoint’ class. d31216 3 a31218 3 ‘gdb.Breakpoint’ constructor. The first one accepts a string like one would pass to the ‘break’ (*note Setting Breakpoints: Set Breaks.) and ‘watch’ (*note Setting Watchpoints: Set Watchpoints.) commands, and can d31228 2 a31229 2 recognized by the ‘break’ command (*note Setting Breakpoints: Set Breaks.) or, in the case of a watchpoint, by the ‘watch’ command d31236 2 a31237 2 create, if TYPE is ‘gdb.BP_WATCHPOINT’. If WP_CLASS is omitted, it defaults to ‘gdb.WP_WRITE’. d31241 2 a31242 2 when created, nor will it be listed in the output from ‘info breakpoints’ (but will be listed with the ‘maint info breakpoints’ d31252 2 a31253 2 interpreting the function passed in ‘spec’ as a fully-qualified name. It is equivalent to ‘break’'s ‘-qualified’ flag (*note d31266 1 a31266 1 The available types are represented by constants defined in the ‘gdb’ d31269 1 a31269 1 ‘gdb.BP_BREAKPOINT’ d31272 1 a31272 1 ‘gdb.BP_HARDWARE_BREAKPOINT’ d31275 1 a31275 1 ‘gdb.BP_WATCHPOINT’ d31278 1 a31278 1 ‘gdb.BP_HARDWARE_WATCHPOINT’ d31281 1 a31281 1 ‘gdb.BP_READ_WATCHPOINT’ d31284 1 a31284 1 ‘gdb.BP_ACCESS_WATCHPOINT’ d31287 1 a31287 1 ‘gdb.BP_CATCHPOINT’ d31289 2 a31290 2 ‘gdb.Breakpoint’ objects, but will be present in ‘gdb.Breakpoint’ objects reported from ‘gdb.BreakpointEvent’s (*note Events In d31294 1 a31294 1 in the ‘gdb’ module: d31296 1 a31296 1 ‘gdb.WP_READ’ d31299 1 a31299 1 ‘gdb.WP_WRITE’ d31302 1 a31302 1 ‘gdb.WP_ACCESS’ d31306 3 a31308 3 The ‘gdb.Breakpoint’ class can be sub-classed and, in particular, you may choose to implement the ‘stop’ method. If this method is defined in a sub-class of ‘gdb.Breakpoint’, it will be called when d31310 1 a31310 1 instantiates that sub-class. If the method returns ‘True’, the d31315 2 a31316 2 ‘stop’ method, each one will be called regardless of the return status of the previous. This ensures that all ‘stop’ methods have d31318 1 a31318 1 the methods returns ‘True’ but the others return ‘False’, the d31327 1 a31327 1 Example ‘stop’ implementation: d31337 2 a31338 2 Return ‘True’ if this ‘Breakpoint’ object is valid, ‘False’ otherwise. A ‘Breakpoint’ object can become invalid if the user d31346 1 a31346 1 Python ‘Breakpoint’ object. Any further access to this object's d31350 1 a31350 1 This attribute is ‘True’ if the breakpoint is enabled, and ‘False’ d31355 1 a31355 1 This attribute is ‘True’ if the breakpoint is silent, and ‘False’ d31359 2 a31360 2 the first command is ‘silent’. This is not reported by the ‘silent’ attribute. d31363 1 a31363 1 This attribute is ‘True’ if the breakpoint is pending, and ‘False’ d31369 1 a31369 1 the breakpoint is not thread-specific, this attribute is ‘None’. d31372 1 a31372 1 Only one of ‘Breakpoint.thread’ or ‘Breakpoint.inferior’ can be set d31379 1 a31379 1 breakpoint is not inferior-specific, this attribute is ‘None’. d31382 1 a31382 1 ‘gdb.BP_BREAKPOINT’ and ‘gdb.BP_HARDWARE_BREAKPOINT’. d31387 1 a31387 1 underlying language is not Ada), this attribute is ‘None’. This d31406 1 a31406 1 when set, or when the ‘info breakpoints’ command is run. This d31414 1 a31414 1 ‘is_valid’ function, will result in an error after the breakpoint d31427 1 a31427 1 ‘None’. This attribute is not writable. d31431 3 a31433 3 for this breakpoint, with elements of type ‘gdb.BreakpointLocation’ (described below). This functionality matches that of the ‘info breakpoint’ command (*note Set Breaks::), in that it only retrieves d31442 1 a31442 1 value is ‘None’. This attribute is not writable. d31447 1 a31447 1 attribute's value is ‘None’. This attribute is writable. d31453 1 a31453 1 this attribute is ‘None’. This attribute is writable. d31459 1 a31459 1 been set, represented in the Python API by the ‘gdb.BreakpointLocation’ d31461 1 a31461 1 retrieved from ‘Breakpoint.locations’ which returns a list of breakpoint d31465 2 a31466 2 location will throw a ‘RuntimeError’ exception. Access the ‘Breakpoint.locations’ attribute again to retrieve the new and valid d31474 1 a31474 1 catchpoints. This will throw a ‘RuntimeError’ exception if the d31479 1 a31479 1 This attribute is of type long. This will throw a ‘RuntimeError’ d31486 1 a31486 1 ‘RuntimeError’ exception if the location has been invalidated. d31489 3 a31491 3 This attribute holds a reference to the ‘gdb.Breakpoint’ owner object, from which this ‘gdb.BreakpointLocation’ was retrieved from. This will throw a ‘RuntimeError’ exception if the location d31497 1 a31497 1 ‘None’. This will throw a ‘RuntimeError’ exception if the location d31502 2 a31503 2 If no full name could be found, this attribute returns ‘None’. This will throw a ‘RuntimeError’ exception if the location has been d31508 1 a31508 1 ‘List’ of the thread group ID's. This will throw a ‘RuntimeError’ d31519 2 a31520 2 of a frame, based on the ‘finish’ command. ‘gdb.FinishBreakpoint’ extends ‘gdb.Breakpoint’. The underlying breakpoint will be disabled d31522 1 a31522 1 (i.e. ‘Breakpoint.stop’ or ‘FinishBreakpoint.out_of_scope’ triggered). d31527 1 a31527 1 Create a finish breakpoint at the return address of the ‘gdb.Frame’ d31534 1 a31534 1 In some circumstances (e.g. ‘longjmp’, C++ exceptions, GDB ‘return’ d31537 1 a31537 1 situation, the ‘out_of_scope’ callback will be triggered. d31539 1 a31539 1 You may want to sub-class ‘gdb.FinishBreakpoint’ and override this d31552 4 a31555 4 build the ‘gdb.FinishBreakpoint’ object had debug symbols, this attribute will contain a ‘gdb.Value’ object corresponding to the return value of the function. The value will be ‘None’ if the function return type is ‘void’ or if the return value was not d31564 1 a31564 1 A “lazy string” is a string whose contents is not retrieved or encoded d31567 7 a31573 7 A ‘gdb.LazyString’ is represented in GDB as an ‘address’ that points to a region of memory, an ‘encoding’ that will be used to encode that region of memory, and a ‘length’ to delimit the region of memory that represents the string. The difference between a ‘gdb.LazyString’ and a string wrapped within a ‘gdb.Value’ is that a ‘gdb.LazyString’ will be treated differently by GDB when printing. A ‘gdb.LazyString’ is retrieved and encoded during printing, while a ‘gdb.Value’ wrapping a d31576 1 a31576 1 A ‘gdb.LazyString’ object has the following functions: d31579 1 a31579 1 Convert the ‘gdb.LazyString’ to a ‘gdb.Value’. This value will d31582 1 a31582 1 ‘gdb.LazyString’. d31605 1 a31605 1 ‘target’ method. *Note Types In Python::. This attribute is not d31616 1 a31616 1 of the ‘gdb.Architecture’ class. d31618 1 a31618 1 A ‘gdb.Architecture’ class has the following methods: d31637 1 a31637 1 element of the returned list is a Python ‘dict’ with the following d31640 1 a31640 1 ‘addr’ d31644 1 a31644 1 ‘asm’ d31648 1 a31648 1 specified by the current CLI variable ‘disassembly-flavor’. d31651 1 a31651 1 ‘length’ d31663 2 a31664 2 If SIGNED is not specified, it defaults to ‘True’. If SIGNED is ‘False’, the returned type will be unsigned. d31667 1 a31667 1 ‘ValueError’ exception. d31670 1 a31670 1 Return a ‘gdb.RegisterDescriptorIterator’ (*note Registers In d31673 1 a31673 1 empty string, then the register group ‘all’ is assumed. d31676 1 a31676 1 Return a ‘gdb.RegisterGroupsIterator’ (*note Registers In Python::) d31678 1 a31678 1 ‘gdb.Architecture’. d31686 2 a31687 2 Python code can request from a ‘gdb.Architecture’ information about the set of registers available (*note ‘Architecture.registers’: d31689 2 a31690 2 a ‘gdb.RegisterDescriptorIterator’, which is an iterator that in turn returns ‘gdb.RegisterDescriptor’ objects. d31692 3 a31694 3 A ‘gdb.RegisterDescriptor’ does not provide the value of a register (*note ‘Frame.read_register’: gdbpy_frame_read_register. for reading a register's value), instead the ‘RegisterDescriptor’ is a way to discover d31697 1 a31697 1 A ‘gdb.RegisterDescriptor’ has the following read-only properties: d31703 1 a31703 1 using the following ‘gdb.RegisterDescriptorIterator’ function: d31707 1 a31707 1 ‘gdb.RegisterDescriptor’ for the register with that name, or ‘None’ d31710 1 a31710 1 Python code can also request from a ‘gdb.Architecture’ information d31712 1 a31712 1 (*note ‘Architecture.register_groups’: gdbpy_architecture_reggroups.). d31719 1 a31719 1 commands like ‘info registers’ (*note ‘info registers REGGROUP’: d31723 2 a31724 2 ‘gdb.RegisterGroupsIterator’, which is an iterator that in turn returns ‘gdb.RegisterGroup’ objects. d31726 1 a31726 1 A ‘gdb.RegisterGroup’ object has the following read-only properties: d31740 1 a31740 1 connection types are ‘native’ and ‘remote’. *Note Inferiors Connections d31744 2 a31745 2 ‘gdb.TargetConnection’, or as one of its sub-classes. To get a list of all connections use ‘gdb.connections’ (*note gdb.connections: d31748 2 a31749 2 To get the connection for a single ‘gdb.Inferior’ read its ‘gdb.Inferior.connection’ attribute (*note gdb.Inferior.connection: d31752 2 a31753 2 Currently there is only a single sub-class of ‘gdb.TargetConnection’, ‘gdb.RemoteTargetConnection’, however, additional sub-classes may be d31768 1 a31768 1 A ‘gdb.TargetConnection’ has the following method: d31771 2 a31772 2 Return ‘True’ if the ‘gdb.TargetConnection’ object is valid, ‘False’ if not. A ‘gdb.TargetConnection’ will become invalid if d31777 1 a31777 1 Reading any of the ‘gdb.TargetConnection’ properties will throw an d31780 1 a31780 1 A ‘gdb.TargetConnection’ has the following read-only properties: d31784 2 a31785 2 This is the same value as displayed in the ‘Num’ column of the ‘info connections’ command output (*note info connections: d31791 1 a31791 1 ‘target’ command (*note target command: Target Commands.). d31795 2 a31796 2 is the same string that is displayed in the ‘Description’ column of the ‘info connection’ command output (*note info connections: d31801 1 a31801 1 connection. This attribute can be ‘None’ if there are no d31805 2 a31806 2 is the ‘remote’ connection, in this case the details string can contain the ‘HOSTNAME:PORT’ that was used to connect to the remote d31809 5 a31813 5 The ‘gdb.RemoteTargetConnection’ class is a sub-class of ‘gdb.TargetConnection’, and is used to represent ‘remote’ and ‘extended-remote’ connections. In addition to the attributes and methods available from the ‘gdb.TargetConnection’ base class, a ‘gdb.RemoteTargetConnection’ has the following method: d31817 2 a31818 2 response. The PACKET should either be a ‘bytes’ object, or a ‘Unicode’ string. d31820 3 a31822 3 If PACKET is a ‘Unicode’ string, then the string is encoded to a ‘bytes’ object using the ASCII codec. If the string can't be encoded then an ‘UnicodeError’ is raised. d31824 2 a31825 2 If PACKET is not a ‘bytes’ object, or a ‘Unicode’ string, then a ‘TypeError’ is raised. If PACKET is empty then a ‘ValueError’ is d31828 1 a31828 1 The response is returned as a ‘bytes’ object. If it is known that d31840 1 a31840 1 This is equivalent to the ‘maintenance packet’ command (*note maint d31859 1 a31859 1 ‘[a-zA-Z][-_.a-zA-Z0-9]*’, it is an error to try and create a d31864 1 a31864 1 ‘gdb.TuiWindow’, described below. It should return an object that d31868 1 a31868 1 an object of type ‘gdb.TuiWindow’. This object has these methods and d31872 1 a31872 1 This method returns ‘True’ when this window is valid. When the d31874 1 a31874 1 layout will be destroyed. At this point, the ‘gdb.TuiWindow’ will d31876 1 a31876 1 ‘is_valid’ will throw an exception. d31878 1 a31878 1 When the TUI is disabled using ‘tui disable’ (*note tui disable: d31880 1 a31880 1 ‘is_valid’ will still return ‘False’ and other methods (and d31902 3 a31904 3 If the FULL_WINDOW parameter is ‘True’, then STRING contains the full contents of the window. This is similar to calling ‘erase’ before ‘write’, but avoids the flickering. d31917 2 a31918 2 When the TUI window is closed, the ‘gdb.TuiWindow’ object will be put into an invalid state. At this time, GDB will call ‘close’ d31928 1 a31928 1 layout. When this happens, GDB will call the ‘render’ method on d31933 1 a31933 1 and send output to the ‘gdb.TuiWindow’. d31955 3 a31957 3 When TUI mouse events are disabled by turning off the ‘tui mouse-events’ setting (*note set tui mouse-events: tui-mouse-events.), then ‘click’ will not be called. d31967 1 a31967 1 ‘gdb.disassembler’ module: d31978 1 a31978 1 description of ‘__init__’ for more details. d31987 1 a31987 1 The ‘gdb.Architecture’ (*note Architectures In Python::) for d31992 1 a31992 1 The ‘gdb.Progspace’ (*note Program Spaces In Python: d31997 2 a31998 2 Returns ‘True’ if the ‘DisassembleInfo’ object is valid, ‘False’ if not. A ‘DisassembleInfo’ object will become d32000 3 a32002 3 ‘DisassembleInfo’ was created, has returned. Calling other ‘DisassembleInfo’ methods, or accessing ‘DisassembleInfo’ properties, will raise a ‘RuntimeError’ exception if it is d32006 3 a32008 3 This can be used to create a new ‘DisassembleInfo’ object that is a copy of INFO. The copy will have the same ‘address’, ‘architecture’, and ‘progspace’ values as INFO, and will d32011 1 a32011 1 This method exists so that sub-classes of ‘DisassembleInfo’ d32013 2 a32014 2 copies of an existing ‘DisassembleInfo’ object, but sub-classes might choose to override the ‘read_memory’ method, d32021 1 a32021 1 bytes, starting at OFFSET from ‘DisassembleInfo.address’. d32030 1 a32030 1 string, just as ‘Inferior.read_memory’ does (*note d32035 1 a32035 1 ‘gdb.MemoryError’ exception is raised (*note Exception d32041 1 a32041 1 important to understand how ‘builtin_disassemble’ makes use of d32049 1 a32049 1 If an implementation of ‘read_memory’ is unable to read the d32052 1 a32052 1 ‘gdb.MemoryError’ should be raised. d32054 3 a32056 3 Raising a ‘MemoryError’ inside ‘read_memory’ does not automatically mean a ‘MemoryError’ will be raised by ‘builtin_disassemble’. It is possible the GDB's builtin d32058 1 a32058 1 When ‘read_memory’ raises the ‘MemoryError’ the builtin d32061 1 a32061 1 ‘builtin_disassemble’ will not itself raise a ‘MemoryError’. d32063 2 a32064 2 Any other exception type raised in ‘read_memory’ will propagate back and be re-raised by ‘builtin_disassemble’. d32067 1 a32067 1 Create a new ‘DisassemblerTextPart’ representing a piece of a d32073 1 a32073 1 ‘DisassemblerResult’ in order to represent the styling within d32077 1 a32077 1 Create a new ‘DisassemblerAddressPart’. ADDRESS is the value d32079 1 a32079 1 ‘DisassemblerAddressPart’ is displayed as an absolute address d32092 3 a32094 3 The ‘__call__’ method must be overridden by sub-classes to perform disassembly. Calling ‘__call__’ on this base class will raise a ‘NotImplementedError’ exception. d32096 1 a32096 1 The INFO argument is an instance of ‘DisassembleInfo’, and d32099 1 a32099 1 If this function returns ‘None’, this indicates to GDB that d32104 1 a32104 1 Alternatively, this function can return a ‘DisassemblerResult’ d32108 1 a32108 1 The ‘__call__’ method can raise a ‘gdb.MemoryError’ exception d32113 3 a32115 3 Ideally, the only three outcomes from invoking ‘__call__’ would be a return of ‘None’, a successful disassembly returned in a ‘DisassemblerResult’, or a ‘MemoryError’ indicating that d32118 1 a32118 1 However, as an implementation of ‘__call__’ could fail due to d32120 2 a32121 2 disassembly is temporarily unavailable, then, if ‘__call__’ raises a ‘GdbError’, the exception will be converted to a d32125 1 a32125 1 Any other exception type raised by the ‘__call__’ method is d32127 2 a32128 2 printed to the error stream according to the ‘set python print-stack’ setting (*note ‘set python print-stack’: d32134 1 a32134 1 ‘builtin_disassemble’ (*note builtin_disassemble::), and an d32136 1 a32136 1 ‘Disassembler.__call__’ (*note Disassembler Class::) if an d32139 1 a32139 1 It is not possible to sub-class the ‘DisassemblerResult’ class. d32141 1 a32141 1 The ‘DisassemblerResult’ class has the following properties and d32150 2 a32151 2 ‘DisassemblerResult’; the other one should be passed the value ‘None’. Alternatively, the arguments can be passed by name, d32154 1 a32154 1 The STRING argument, if not ‘None’, is a non-empty string that d32158 2 a32159 2 style the result as a single ‘DisassemblerTextPart’ with ‘STYLE_TEXT’ style (*note Disassembler Styling Parts::). d32161 2 a32162 2 The PARTS argument, if not ‘None’, is a non-empty sequence of ‘DisassemblerPart’ objects. Each part represents a small part d32165 2 a32166 2 displayed by GDB with full styling information (*note ‘set style disassembler enabled’: style_disassembler_enabled.). d32180 1 a32180 1 ‘DisassemblerPart’ objects, the STRING property will still be d32182 1 a32182 1 ‘DisassemblerPart.string’ values of each component part (*note d32187 1 a32187 1 ‘DisassemblerPart’ objects. Each ‘DisassemblerPart’ object d32191 1 a32191 1 ‘set style disassembler enabled’: d32195 1 a32195 1 than with a sequence of ‘DisassemblerPart’ objects, the PARTS d32198 1 a32198 1 ‘DisassemblerTextPart’ object, the string of which will d32200 1 a32200 1 be ‘STYLE_TEXT’. d32210 4 a32213 4 ‘builtin_disassemble’ (*note builtin_disassemble::) and are returned within the ‘DisassemblerResult’ object, or can be created by calling the ‘text_part’ and ‘address_part’ methods on the ‘DisassembleInfo’ class (*note DisassembleInfo Class::). d32215 1 a32215 1 The ‘DisassemblerPart’ class has a single property: d32224 1 a32224 1 The ‘DisassemblerTextPart’ class represents a piece of the d32227 1 a32227 1 ‘DisassembleInfo.text_part’ to create a new instance of this class d32231 1 a32231 1 ‘DisassemblerTextPart’ has the following additional property: d32240 1 a32240 1 The ‘DisassemblerAddressPart’ class represents an absolute address d32242 2 a32243 2 ‘DisassemblerAddressPart’ instead of a ‘DisassemblerTextPart’ with ‘STYLE_ADDRESS’ is preferred, GDB will display the address as both d32245 2 a32246 2 next to the address. Using ‘DisassemblerAddressPart’ also ensures that user settings such as ‘set print max-symbolic-offset’ are d32253 4 a32256 4 In this instruction the ‘0x401136 ’ was generated from a single ‘DisassemblerAddressPart’. The ‘0x401136’ will be styled with ‘STYLE_ADDRESS’, and ‘foo’ will be styled with ‘STYLE_SYMBOL’. The ‘<’ and ‘>’ will be styled as ‘STYLE_TEXT’. d32259 1 a32259 1 ‘DisassemblerTextPart’ with style ‘STYLE_ADDRESS’ can be used d32263 1 a32263 1 ‘DisassembleInfo.address_part’ to create a new instance of this d32267 1 a32267 1 ‘DisassemblerAddressPart’ has the following additional property: d32271 1 a32271 1 object's ‘__init__’ method. d32281 1 a32281 1 ‘gdb.disassembler.STYLE_TEXT’ d32287 1 a32287 1 ‘gdb.disassembler.STYLE_MNEMONIC’ d32292 1 a32292 1 GDB styles text with this style using the ‘disassembler mnemonic’ d32295 1 a32295 1 ‘gdb.disassembler.STYLE_SUB_MNEMONIC’ d32300 1 a32300 1 ‘STYLE_MNEMONIC’). d32306 3 a32308 3 The ‘add’ is the primary instruction mnemonic, and would be given style ‘STYLE_MNEMONIC’, while ‘lsl’ is the sub-mnemonic, and would be given the style ‘STYLE_SUB_MNEMONIC’. d32310 1 a32310 1 GDB styles text with this style using the ‘disassembler mnemonic’ d32313 1 a32313 1 ‘gdb.disassembler.STYLE_ASSEMBLER_DIRECTIVE’ d32320 2 a32321 2 In this case, the ‘.word’ would be give the ‘STYLE_ASSEMBLER_DIRECTIVE’ style. An assembler directive is d32325 1 a32325 1 GDB styles text with this style using the ‘disassembler mnemonic’ d32328 1 a32328 1 ‘gdb.disassembler.STYLE_REGISTER’ d32332 1 a32332 1 GDB styles text with this style using the ‘disassembler register’ d32335 1 a32335 1 ‘gdb.disassembler.STYLE_ADDRESS’ d32339 2 a32340 2 When creating a ‘DisassemblerTextPart’ with this style, you should consider if a ‘DisassemblerAddressPart’ would be more appropriate. d32344 1 a32344 1 GDB styles text with this style using the ‘disassembler address’ d32347 1 a32347 1 ‘gdb.disassembler.STYLE_ADDRESS_OFFSET’ d32361 1 a32361 1 GDB styles text with this style using the ‘disassembler immediate’ d32364 2 a32365 2 ‘gdb.disassembler.STYLE_IMMEDIATE’ Use ‘STYLE_IMMEDIATE’ for any numerical values within a d32367 2 a32368 2 address offsets, or register numbers (The styles ‘STYLE_ADDRESS’, ‘STYLE_ADDRESS_OFFSET’, or ‘STYLE_REGISTER’ can be used in those d32371 1 a32371 1 GDB styles text with this style using the ‘disassembler immediate’ d32374 1 a32374 1 ‘gdb.disassembler.STYLE_SYMBOL’ d32383 2 a32384 2 Here ‘foo’ is the name of a symbol, and should be given the ‘STYLE_SYMBOL’ style. d32387 1 a32387 1 automatically by the ‘DisassemblerAddressPart’ class (*note d32390 1 a32390 1 GDB styles text with this style using the ‘disassembler symbol’ d32393 1 a32393 1 ‘gdb.disassembler.STYLE_COMMENT_START’ d32396 1 a32396 1 ‘DisassemblerTextPiece’ to which they are applied, the comment d32400 1 a32400 1 This means that, after a ‘STYLE_COMMENT_START’ piece has been seen, d32404 1 a32404 1 GDB styles text with this style using the ‘disassembler comment’ d32407 1 a32407 1 The following functions are also contained in the ‘gdb.disassembler’ d32412 1 a32412 1 ‘gdb.disassembler.Disassembler’ or ‘None’. d32414 1 a32414 1 The optional ARCHITECTURE is either a string, or the value ‘None’. d32416 1 a32416 1 known to GDB, as returned either from ‘gdb.Architecture.name’ d32418 1 a32418 1 ‘gdb.architecture_names’ (*note gdb.architecture_names: d32422 1 a32422 1 ARCHITECTURE, or if ARCHITECTURE is ‘None’, then DISASSEMBLER will d32426 1 a32426 1 single global disassembler. Calling ‘register_disassembler’ for an d32431 1 a32431 1 If DISASSEMBLER is ‘None’ then any disassembler currently d32437 1 a32437 1 ARCHITECTURE set to ‘None’). Only one disassembler is called to d32448 1 a32448 1 You can use the ‘maint info python-disassemblers’ command (*note d32455 1 a32455 1 sub-class, of ‘DisassembleInfo’. d32458 3 a32460 3 ‘read_memory’ method on INFO will be called. By sub-classing ‘DisassembleInfo’ and overriding the ‘read_memory’ method, it is possible to intercept calls to ‘read_memory’ from the builtin d32464 1 a32464 1 ‘DisassembleInfo.read_memory’ raises a ‘gdb.MemoryError’, it is the d32472 1 a32472 1 ‘DisassemblerResult’ is returned from ‘builtin_disassemble’, d32476 1 a32476 1 A ‘MemoryError’ will be raised if ‘builtin_disassemble’ is unable d32480 2 a32481 2 Any exception that is not a ‘MemoryError’, that is raised in a call to ‘read_memory’, will pass through ‘builtin_disassemble’, and be d32485 2 a32486 2 fail for reasons that are not covered by ‘MemoryError’. In these cases, a ‘GdbError’ will be raised. The contents of the exception d32492 1 a32492 1 ‘## Comment’, to each line of disassembly output: d32506 2 a32507 2 The following example creates a sub-class of ‘DisassembleInfo’ in order to intercept the ‘read_memory’ calls, within ‘read_memory’ any d32559 3 a32561 3 object which has the ‘name’ and ‘enabled’ attributes, and implements the ‘__call__’ method. When GDB encounters an objfile for which it is unable to find any debug information, it invokes the ‘__call__’ method. d32564 1 a32564 1 The ‘gdb.missing_debug’ Module d32567 1 a32567 1 GDB comes with a ‘gdb.missing_debug’ module which contains the following d32572 1 a32572 1 ‘MissingDebugHandler’ is a base class from which user-created d32574 2 a32575 2 from this class, so long as any user created handler has the ‘name’ and ‘enabled’ attributes, and implements the ‘__call__’ method. d32580 2 a32581 2 characters ‘[-_a-zA-Z0-9]’, creating a handler with an invalid name raises a ‘ValueError’ exception. d32584 2 a32585 2 Sub-classes must override the ‘__call__’ method. The OBJFILE argument will be a ‘gdb.Objfile’, this is the objfile for d32588 1 a32588 1 The return value from the ‘__call__’ method indicates what GDB d32591 1 a32591 1 • ‘None’ d32596 1 a32596 1 • ‘True’ d32612 1 a32612 1 • ‘False’ d32620 1 a32620 1 • A string d32627 2 a32628 2 Invoking the ‘__call__’ method from this base class will raise a ‘NotImplementedError’ exception. d32632 1 a32632 1 handler passed to the ‘__init__’ method. d32635 2 a32636 2 A modifiable attribute containing a boolean; when ‘True’, the handler is enabled, and will be used by GDB. When ‘False’, d32640 1 a32640 1 replace=False) d32643 1 a32643 1 HANDLER is an instance of a sub-class of ‘MissingDebugHandler’, or d32645 1 a32645 1 methods as ‘MissingDebugHandler’. d32648 2 a32649 2 be either a ‘gdb.Progspace’ (*note Progspaces In Python::) or ‘None’, in which case the handler is registered globally. The d32653 1 a32653 1 name raises an exception unless REPLACE is ‘True’, in which case d32659 1 a32659 1 returns a value other than ‘None’, no further handlers are called d32668 1 a32668 1 When a new object file is read (for example, due to the ‘file’ command, d32670 2 a32671 2 Python support scripts in several ways: ‘OBJFILE-gdb.py’ and ‘.debug_gdb_scripts’ section. *Note Auto-loading extensions::. d32679 1 a32679 1 ‘set auto-load python-scripts [on|off]’ d32682 1 a32682 1 ‘show auto-load python-scripts’ d32685 1 a32685 1 ‘info auto-load python-scripts [REGEXP]’ d32689 1 a32689 1 the ‘.debug_gdb_scripts’ section and were either not found (*note d32691 1 a32691 1 ‘auto-load safe-path’ rejection (*note Auto-loading::). This is d32707 2 a32708 2 When reading an auto-loaded file or script, GDB sets the “current objfile”. This is available via the ‘gdb.current_objfile’ function d32735 3 a32737 3 ‘PrettyPrinter (NAME, SUBPRINTERS=None)’ This class specifies the API that makes ‘info pretty-printer’, ‘enable pretty-printer’ and ‘disable pretty-printer’ work. d32740 1 a32740 1 ‘SubPrettyPrinter (NAME)’ d32744 1 a32744 1 ‘RegexpCollectionPrettyPrinter (NAME)’ d32749 3 a32751 3 ‘FlagEnumerationPrinter (NAME)’ A pretty-printer which handles printing of ‘enum’ values. Unlike GDB's built-in ‘enum’ printing, this printer attempts to work d32754 1 a32754 1 the name of the ‘enum’ type to look up. d32756 1 a32756 1 ‘register_pretty_printer (OBJ, PRINTER, REPLACE=False)’ d32758 2 a32759 2 is ‘True’ then any existing copy of the printer is replaced. Otherwise a ‘RuntimeError’ exception is raised if a printer with d32769 1 a32769 1 ‘gdb.Type’ objects. d32771 1 a32771 1 ‘get_basic_type (TYPE)’ d32790 2 a32791 2 ‘has_field (TYPE, FIELD)’ Return ‘True’ if TYPE, assumed to be a type with fields (e.g., a d32794 2 a32795 2 ‘make_enum_dict (ENUM_TYPE)’ Return a Python ‘dictionary’ type produced from ENUM_TYPE. d32797 1 a32797 1 ‘deep_items (TYPE)’ d32799 2 a32800 2 ‘gdb.Type.iteritems’ method, except that the iterator returned by ‘deep_items’ will recursively traverse anonymous struct or union d32820 1 a32820 1 ‘get_type_recognizers ()’ d32825 1 a32825 1 ‘apply_type_recognizers (recognizers, type_obj)’ d32828 1 a32828 1 Otherwise, return ‘None’. This is called by GDB during the d32831 1 a32831 1 ‘register_type_printer (locus, printer)’ d32834 3 a32836 3 argument is either a ‘gdb.Objfile’, in which case the printer is registered with that objfile; a ‘gdb.Progspace’, in which case the printer is registered with that progspace; or ‘None’, in which case d32839 1 a32839 1 ‘TypePrinter’ d32856 1 a32856 1 ‘substitute_prompt (STRING)’ d32863 1 a32863 1 ‘\\’ d32865 1 a32865 1 ‘\e’ d32867 1 a32867 1 ‘\f’ d32870 1 a32870 1 ‘\n’ d32872 1 a32872 1 ‘\p’ d32875 1 a32875 1 ‘\r’ d32877 1 a32877 1 ‘\t’ d32880 1 a32880 1 ‘\v’ d32882 1 a32882 1 ‘\w’ d32884 1 a32884 1 ‘\[’ d32890 1 a32890 1 ‘\]’ d32909 1 a32909 1 is available only if GDB was configured using ‘--with-guile’. d32935 1 a32935 1 ‘DATA-DIRECTORY/guile’, where DATA-DIRECTORY is the data directory as d32937 1 a32937 1 as the “guile directory”, is automatically added to the Guile Search d32949 5 a32953 5 ‘guile-repl’ ‘gr’ The ‘guile-repl’ command can be used to start an interactive Guile prompt or “repl”. To return to GDB, type ‘,q’ or the ‘EOF’ character (e.g., ‘Ctrl-D’ on an empty prompt). These commands do d32956 3 a32958 3 ‘guile [SCHEME-EXPRESSION]’ ‘gu [SCHEME-EXPRESSION]’ The ‘guile’ command can be used to evaluate a Scheme expression. d32972 3 a32974 3 If you do not provide an argument to ‘guile’, it will act as a multi-line command, like ‘define’. In this case, the Guile script is made up of subsequent command lines, given after the ‘guile’ d32976 1 a32976 1 ‘end’. For example: d32987 2 a32988 2 ‘source script-name’ The script name must end with ‘.scm’ and GDB must be configured to d32990 1 a32990 1 ‘script-extension’ setting. *Note Extending GDB: Extending GDB. d32992 2 a32993 2 ‘guile (load "script-name")’ This method uses the ‘load’ Guile function. It takes a string d33005 1 a33005 1 ‘help guile’, or by issuing the command ‘,help’ from an interactive d33007 2 a33008 2 doc strings which can be obtained with ‘,describe PROCEDURE-NAME’ or ‘,d PROCEDURE-NAME’ from the Guile interactive prompt. d33044 2 a33045 2 At startup, GDB overrides Guile's ‘current-output-port’ and ‘current-error-port’ to print using GDB's output-paging streams. A d33048 1 a33048 1 Guile ‘signal’ exception is thrown with value ‘SIGINT’. d33052 2 a33053 2 evaluations in Guile and in GDB are counted separately, ‘$1’ in Guile is not the same value as ‘$1’ in GDB. d33062 2 a33063 2 • GDB installs handlers for ‘SIGCHLD’ and ‘SIGINT’. Guile code must not override these, or even change the options using ‘sigaction’. d33066 1 a33066 1 common for GUI toolkits to install a ‘SIGCHLD’ handler. d33068 1 a33068 1 • GDB takes care to mark its internal file descriptors as d33075 1 a33075 1 GDB introduces a new Guile module, named ‘gdb’. All methods and d33077 1 a33077 1 automatically ‘import’ the ‘gdb’ module, scripts must do this d33079 1 a33079 1 GDB leaves the choice of how the ‘gdb’ module is imported to the user. d33088 1 a33088 1 ‘gdb:’ as a prefix to all module functions and variables. d33090 2 a33091 2 The rest of this manual assumes the ‘gdb’ module has been imported without any prefix. See the Guile documentation for ‘use-modules’ for d33104 1 a33104 1 The ‘(gdb)’ module provides these basic Guile functions. d33114 1 a33114 1 be a boolean value. If omitted, it defaults to ‘#f’. d33118 3 a33120 3 If the TO-STRING parameter is ‘#t’, then output will be collected by ‘execute’ and returned as a string. The default is ‘#f’, in which case the return value is unspecified. If TO-STRING is ‘#t’, d33132 1 a33132 1 doesn't exist in the value history, a ‘gdb:error’ exception will be d33136 1 a33136 1 of ‘’ (*note Values From Inferior In Guile::). d33138 1 a33138 1 _Note:_ GDB's value history is independent of Guile's. ‘$1’ in d33140 1 a33140 1 from GDB's command line and ‘$1’ from Guile's history contains the d33144 1 a33144 1 Append VALUE, an instance of ‘’, to GDB's value history. d33153 1 a33153 1 it, and return the result as a ‘’. The EXPRESSION must d33160 1 a33160 1 convenience variable (*note Convenience Vars::) as a ‘’. d33184 1 a33184 1 string passed to ‘--host’ when GDB was configured. d33188 1 a33188 1 string passed to ‘--target’ when GDB was configured. d33196 1 a33196 1 The values exposed by GDB to Guile are known as “GDB objects”. There d33201 1 a33201 1 Return the kind of the GDB object, e.g., ‘’, as a d33206 1 a33206 1 ‘’ d33209 1 a33209 1 ‘’ d33212 1 a33212 1 ‘’ d33215 1 a33215 1 ‘’ d33218 1 a33218 1 ‘’ d33221 1 a33221 1 ‘’ d33224 1 a33224 1 ‘’ d33227 1 a33227 1 ‘’ d33230 1 a33230 1 ‘’ d33233 1 a33233 1 ‘’ d33236 1 a33236 1 ‘’ d33239 1 a33239 1 ‘’ d33242 1 a33242 1 ‘’ d33245 1 a33245 1 ‘’ d33248 1 a33248 1 ‘’ d33251 1 a33251 1 ‘’ d33254 1 a33254 1 ‘’ d33257 1 a33257 1 ‘’ d33260 1 a33260 1 ‘’ d33263 1 a33263 1 ‘’ d33267 1 a33267 1 function ‘eq?’ may be applied to them. d33269 9 a33277 9 ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ ‘’ d33285 1 a33285 1 When executing the ‘guile’ command, Guile exceptions uncaught within the d33287 3 a33289 3 If the command that called ‘guile’ does not handle the error, GDB will terminate it and report the error according to the setting of the ‘guile print-stack’ parameter. d33291 1 a33291 1 The ‘guile print-stack’ parameter has three settings: d33293 1 a33293 1 ‘none’ d33296 1 a33296 1 ‘message’ d33306 1 a33306 1 ‘full’ d33341 1 a33341 1 exceptions like ‘wrong-type-arg’ and ‘out-of-range’. d33343 2 a33344 2 User interrupt (via ‘C-c’ or by typing ‘q’ at a pagination prompt) is translated to a Guile ‘signal’ exception with value ‘SIGINT’. d33348 1 a33348 1 ‘gdb:error’ d33351 1 a33351 1 ‘gdb:invalid-object’ d33354 1 a33354 1 ‘’ object becomes invalid if the user deletes it d33359 1 a33359 1 ‘gdb:memory-error’ d33363 1 a33363 1 ‘gdb:pp-type-error’ d33368 1 a33368 1 ‘(gdb)’ module. d33371 1 a33371 1 Return a ‘’ object given by its KEY and ARGS, which d33376 2 a33377 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d33380 1 a33380 1 Return the ARGS field of a ‘’ object. d33383 1 a33383 1 Return the ARGS field of a ‘’ object. d33392 1 a33392 1 type ‘’. GDB uses this object for its internal bookkeeping d33395 1 a33395 1 GDB does not memoize ‘’ objects. ‘make-value’ always d33403 2 a33404 2 A ‘’ that represents a function can be executed via inferior function call with ‘value-call’. Any arguments provided to the d33408 1 a33408 1 For example, ‘some-val’ is a ‘’ instance representing a d33414 1 a33414 1 Any values returned from a function call are ‘’ objects. d33418 2 a33419 2 the value's data type. For example, ‘(+ (parse-and-eval "int_variable") 2)’ does not work. And inferior values that are structures or instances d33421 1 a33421 1 ‘value-field’ must be used. d33423 1 a33423 1 The following value-related procedures are provided by the ‘(gdb)’ d33427 2 a33428 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d33431 1 a33431 1 Many Scheme values can be converted directly to a ‘’ d33441 1 a33441 1 ‘make-value’ is not specified: d33448 3 a33450 3 A Scheme integer is converted to the first of a C ‘int’, ‘unsigned int’, ‘long’, ‘unsigned long’, ‘long long’ or ‘unsigned long long’ type for the current architecture that d33454 1 a33454 1 integer an ‘out-of-range’ exception is thrown. d33457 1 a33457 1 A Scheme real is converted to the C ‘double’ type for the d33465 1 a33465 1 Guile's ‘SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE’ conversion d33469 1 a33469 1 a ‘wrong-type-arg’ exception is thrown. d33471 3 a33473 3 ‘’ If VALUE is a ‘’ object (*note Lazy Strings In Guile::), then the ‘lazy-string->value’ procedure is d33477 1 a33477 1 a ‘wrong-type-arg’ exception is thrown. d33482 1 a33482 1 the result is essentially created by using ‘memcpy’. d33485 1 a33485 1 result is an array of type ‘uint8’ of the same length. d33488 2 a33489 2 Return ‘#t’ if the compiler optimized out VALUE, thus it is not available for fetching from the inferior. Otherwise return ‘#f’. d33492 2 a33493 2 If VALUE is addressable, returns a ‘’ object representing the address. Otherwise, ‘#f’ is returned. d33496 1 a33496 1 Return the type of VALUE as a ‘’ object (*note Types In d33511 1 a33511 1 just return the static type of the value as in ‘ptype foo’. *Note d33515 1 a33515 1 Return a new instance of ‘’ that is the result of d33517 1 a33517 1 ‘’ object. If the cast cannot be performed for some d33521 1 a33521 1 Like ‘value-cast’, but works as if the C++ ‘dynamic_cast’ operator d33525 1 a33525 1 Like ‘value-cast’, but works as if the C++ ‘reinterpret_cast’ d33529 1 a33529 1 For pointer data types, this method returns a new ‘’ d33531 1 a33531 1 example, if ‘foo’ is a C pointer to an ‘int’, declared in your C d33536 2 a33537 2 then you can use the corresponding ‘’ to access what ‘foo’ points to like this: d33541 2 a33542 2 The result ‘bar’ will be a ‘’ object holding the value pointed to by ‘foo’. d33544 2 a33545 2 A similar function ‘value-referenced-value’ exists which also returns ‘’ objects corresponding to the values pointed d33547 5 a33551 5 reference values). However, the behavior of ‘value-dereference’ differs from ‘value-referenced-value’ by the fact that the behavior of ‘value-dereference’ is identical to applying the C unary operator ‘*’ on a given value. For example, consider a reference to a pointer ‘ptrref’, declared in your C++ program as d33559 6 a33564 6 Though ‘ptrref’ is a reference value, one can apply the method ‘value-dereference’ to the ‘’ object corresponding to it and obtain a ‘’ which is identical to that corresponding to ‘val’. However, if you apply the method ‘value-referenced-value’, the result would be a ‘’ object identical to that corresponding to ‘ptr’. d33570 4 a33573 4 The ‘’ object ‘scm-val’ is identical to that corresponding to ‘val’, and ‘scm-ptr’ is identical to that corresponding to ‘ptr’. In general, ‘value-dereference’ can be applied whenever the C unary operator ‘*’ can be applied to the d33575 1 a33575 1 ‘value-dereference’ and ‘value-referenced-value’ is allowed, the d33578 2 a33579 2 ‘’ objects corresponding to pointers (‘’ objects with type code ‘TYPE_CODE_PTR’) in a C/C++ program. d33583 1 a33583 1 ‘’ object corresponding to the value referenced by the d33585 1 a33585 1 ‘value-dereference’ and ‘value-referenced-value’ produce identical d33587 2 a33588 2 ‘value-dereference’ cannot get the values referenced by reference values. For example, consider a reference to an ‘int’, declared in d33594 4 a33597 4 then applying ‘value-dereference’ to the ‘’ object corresponding to ‘ref’ will result in an error, while applying ‘value-referenced-value’ will result in a ‘’ object identical to that corresponding to ‘val’. d33603 2 a33604 2 The ‘’ object ‘scm-val’ is identical to that corresponding to ‘val’. d33607 2 a33608 2 Return a new ‘’ object which is a reference to the value encapsulated by ‘’ object VALUE. d33611 2 a33612 2 Return a new ‘’ object which is an rvalue reference to the value encapsulated by ‘’ object VALUE. d33615 2 a33616 2 Return a new ‘’ object which is a ‘const’ version of ‘’ object VALUE. d33619 1 a33619 1 Return field FIELD-NAME from ‘’ object VALUE. d33623 1 a33623 1 must be a subscriptable ‘’ object. d33632 1 a33632 1 Return the Scheme boolean representing ‘’ VALUE. The d33636 1 a33636 1 Return the Scheme integer representing ‘’ VALUE. The d33640 1 a33640 1 Return the Scheme real number representing ‘’ VALUE. d33644 1 a33644 1 Return a Scheme bytevector with the raw contents of ‘’ d33661 2 a33662 2 pointer to or an array of characters or ints of type ‘wchar_t’, ‘char16_t’, or ‘char32_t’. d33665 2 a33666 2 naming the encoding of the string in the ‘’, such as ‘"ascii"’, ‘"iso-8859-6"’ or ‘"utf-8"’. It accepts the same d33668 1 a33668 1 ‘scm_from_stringn’ function, and the Guile codec machinery will be d33670 1 a33670 1 ENCODING is the empty string, then either the ‘target-charset’ d33675 3 a33677 3 The optional ERRORS argument is one of ‘#f’, ‘error’ or ‘substitute’. ‘error’ and ‘substitute’ must be symbols. If ERRORS is not specified, or if its value is ‘#f’, then the default d33679 1 a33679 1 ‘set-port-conversion-strategy!’. If the value is ‘'error’ then an d33681 1 a33681 1 is ‘'substitute’ then any conversion error is replaced with d33686 1 a33686 1 Scheme integer and not a ‘’ integer. d33690 2 a33691 2 If this ‘’ represents a string, then this method converts VALUE to a ‘’ integer. d33714 2 a33715 2 Return ‘#t’ if VALUE has not yet been fetched from the inferior. Otherwise return ‘#f’. GDB does not fetch values until necessary, d33720 2 a33721 2 The value of ‘somevar’ is not fetched at this time. It will be fetched when the value is needed, or when the ‘fetch-lazy’ d33725 2 a33726 2 Return a ‘’ that will be lazily fetched from the target. The object of type ‘’ whose value to fetch is specified d33731 1 a33731 1 If VALUE is a lazy value (‘(value-lazy? value)’ is ‘#t’), then the d33740 1 a33740 1 Return the string representation (print form) of ‘’ d33749 2 a33750 2 The ‘(gdb)’ module provides several functions for performing arithmetic on ‘’ objects. The arithmetic is performed as if it were d33806 1 a33806 1 Scheme does not provide a ‘not-equal’ function, and thus Guile d33815 1 a33815 1 GDB represents types from the inferior in objects of type ‘’. d33817 1 a33817 1 The following type-related procedures are provided by the ‘(gdb)’ d33821 2 a33822 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d33827 1 a33827 1 If BLOCK is given, it is an object of type ‘’, and NAME d33831 1 a33831 1 Ordinarily, this function will return an instance of ‘’. d33836 1 a33836 1 ‘TYPE_CODE_’ constants defined below. d33840 2 a33841 2 ‘struct’, ‘union’, or ‘enum’ in C and C++; not all languages have this concept. If this type has no tag name, then ‘#f’ is returned. d33844 1 a33844 1 Return the name of TYPE. If this type has no name, then ‘#f’ is d33849 2 a33850 2 anonymous types. For example, for an anonymous C struct ‘"struct {...}"’ is returned. d33853 2 a33854 2 Return the size of this type, in target ‘char’ units. Usually, a target's ‘char’ type will be an 8-bit byte. However, on some d33858 1 a33858 1 Return a new ‘’ that represents the real type of TYPE, d33862 1 a33862 1 Return a new ‘’ object which represents an array of this d33870 1 a33870 1 Return a new ‘’ object which represents a vector of this d33877 1 a33877 1 The difference between an ‘array’ and a ‘vector’ is that arrays d33883 1 a33883 1 Return a new ‘’ object which represents a pointer to d33891 1 a33891 1 Return a new ‘’ object which represents a reference to d33895 1 a33895 1 Return a new ‘’ object which represents the target type d33909 2 a33910 2 Return a new ‘’ object which represents a ‘const’-qualified variant of TYPE. d33913 2 a33914 2 Return a new ‘’ object which represents a ‘volatile’-qualified variant of TYPE. d33917 3 a33919 3 Return a new ‘’ object which represents an unqualified variant of TYPE. That is, the result is neither ‘const’ nor ‘volatile’. d33922 1 a33922 1 Return the number of fields of ‘’ TYPE. d33926 1 a33926 1 types, ‘fields’ has the usual meaning. Range types have two d33940 1 a33940 1 type ‘’. *Note Fields of a type in Guile::. If the d33944 2 a33945 2 For example, if ‘some-type’ is a ‘’ instance holding a structure type, you can access its ‘foo’ field with: d33949 1 a33949 1 ‘bar’ will be a ‘’ object. d33952 2 a33953 2 Return ‘#t’ if ‘’ TYPE has field named NAME. Otherwise return ‘#f’. d33957 1 a33957 1 defined in the ‘(gdb)’ module: d33959 1 a33959 1 ‘TYPE_CODE_PTR’ d33962 1 a33962 1 ‘TYPE_CODE_ARRAY’ d33965 1 a33965 1 ‘TYPE_CODE_STRUCT’ d33968 1 a33968 1 ‘TYPE_CODE_UNION’ d33971 1 a33971 1 ‘TYPE_CODE_ENUM’ d33974 1 a33974 1 ‘TYPE_CODE_FLAGS’ d33977 1 a33977 1 ‘TYPE_CODE_FUNC’ d33980 1 a33980 1 ‘TYPE_CODE_INT’ d33983 1 a33983 1 ‘TYPE_CODE_FLT’ d33986 2 a33987 2 ‘TYPE_CODE_VOID’ The special type ‘void’. d33989 1 a33989 1 ‘TYPE_CODE_SET’ d33992 1 a33992 1 ‘TYPE_CODE_RANGE’ d33995 1 a33995 1 ‘TYPE_CODE_STRING’ d34000 1 a34000 1 ‘TYPE_CODE_BITSTRING’ d34003 1 a34003 1 ‘TYPE_CODE_ERROR’ d34006 1 a34006 1 ‘TYPE_CODE_METHOD’ d34009 1 a34009 1 ‘TYPE_CODE_METHODPTR’ d34012 1 a34012 1 ‘TYPE_CODE_MEMBERPTR’ d34015 1 a34015 1 ‘TYPE_CODE_REF’ d34018 1 a34018 1 ‘TYPE_CODE_RVALUE_REF’ d34021 1 a34021 1 ‘TYPE_CODE_CHAR’ d34024 1 a34024 1 ‘TYPE_CODE_BOOL’ d34027 1 a34027 1 ‘TYPE_CODE_COMPLEX’ d34030 1 a34030 1 ‘TYPE_CODE_TYPEDEF’ d34033 1 a34033 1 ‘TYPE_CODE_NAMESPACE’ d34036 1 a34036 1 ‘TYPE_CODE_DECFLOAT’ d34039 1 a34039 1 ‘TYPE_CODE_INTERNAL_FUNCTION’ d34043 1 a34043 1 ‘gdb.TYPE_CODE_XMETHOD’ d34047 1 a34047 1 ‘gdb.TYPE_CODE_FIXED_POINT’ d34050 1 a34050 1 ‘gdb.TYPE_CODE_NAMESPACE’ d34053 1 a34053 1 Further support for types is provided in the ‘(gdb types)’ Guile d34056 1 a34056 1 Each field is represented as an object of type ‘’. d34058 1 a34058 1 The following field-related procedures are provided by the ‘(gdb)’ d34062 2 a34063 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d34066 1 a34066 1 Return the name of the field, or ‘#f’ for anonymous fields. d34070 1 a34070 1 ‘’, but it can be ‘#f’ in some situations. d34073 1 a34073 1 Return the enum value represented by ‘’ FIELD. d34076 2 a34077 2 Return the bit position of ‘’ FIELD. This attribute is not available for ‘static’ fields (as in C++). d34081 1 a34081 1 ‘’ FIELD in bits. Otherwise, zero is returned; in which d34085 2 a34086 2 Return ‘#t’ if the field is artificial, usually meaning that it was provided by the compiler and not the user. Otherwise return ‘#f’. d34089 2 a34090 2 Return ‘#t’ if the field represents a base class of a C++ structure. Otherwise return ‘#f’. d34102 1 a34102 1 ‘make-pretty-printer’. d34105 1 a34105 1 ‘(gdb)’ module: d34108 1 a34108 1 Return a ‘’ object named NAME. d34114 1 a34114 1 Otherwise LOOKUP-FUNCTION returns ‘#f’. d34117 2 a34118 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34121 1 a34121 1 Return ‘#t’ if PRETTY-PRINTER is enabled. Otherwise return ‘#f’. d34136 1 a34136 1 Return an object of type ‘’. d34140 1 a34140 1 ‘display-hint’ d34143 1 a34143 1 must be a string or ‘#f’ (meaning there is no hint). Several d34146 1 a34146 1 ‘array’ d34148 2 a34149 2 The CLI uses this to respect parameters such as ‘set print elements’ and ‘set print array’. d34151 1 a34151 1 ‘map’ d34156 1 a34156 1 ‘string’ d34158 1 a34158 1 If the printer's ‘to-string’ function returns a Guile d34162 2 a34163 2 possibly escaping some characters, respecting ‘set print elements’, and the like. d34165 1 a34165 1 ‘to-string’ d34167 1 a34167 1 ‘’ object, or ‘#f’. d34169 1 a34169 1 When printing from the CLI, if the ‘to-string’ method exists, d34171 1 a34171 1 ‘children’. Exactly how this formatting is done is dependent d34174 2 a34175 2 Settings::), the CLI may print just the result of ‘to-string’ in a stack trace, omitting the result of ‘children’. d34180 1 a34180 1 ‘’, then GDB prints this value. This may result in d34184 1 a34184 1 convertible to a ‘’, then GDB performs the d34188 1 a34188 1 to ‘’; other types are not. d34190 1 a34190 1 Finally, if this method returns ‘#f’ then no further d34197 1 a34197 1 TO-STRING may also be ‘#f’ in which case it is left to d34200 1 a34200 1 ‘children’ d34202 1 a34202 1 ‘’ object, or ‘#f’. d34213 1 a34213 1 If CHILDREN is ‘#f’, GDB will act as though the value has no d34216 2 a34217 2 Children may be hidden from display based on the value of ‘set print max-depth’ (*note Print Settings::). d34220 1 a34220 1 pretty-printer for a ‘’: d34223 1 a34223 1 This function takes a ‘’ object as an argument. If a d34225 1 a34225 1 such printer exists, then this returns ‘#f’. d34235 2 a34236 2 • Per-objfile list of pretty-printers (*note Objfiles In Guile::). • Per-progspace list of pretty-printers (*note Progspaces In d34238 1 a34238 1 • The global list of pretty-printers (*note Guile Pretty Printing d34243 8 a34250 8 lookup function returns a non-‘#f’ value or when the list is exhausted. Lookup functions must return either a ‘’ object or ‘#f’. Otherwise an exception is thrown. GDB first checks the result of ‘objfile-pretty-printers’ of each ‘’ in the current program space and iteratively calls each enabled lookup function in the list for that ‘’ until a non-‘#f’ object is returned. If no pretty-printer is found in the d34252 2 a34253 2 ‘progspace-pretty-printers’ of the current program space, calling each enabled function until a non-‘#f’ object is returned. After these lists d34255 2 a34256 2 with ‘pretty-printers’, again calling each enabled function until a non-‘#f’ object is returned. d34261 1 a34261 1 ‘’ object is returned. d34269 1 a34269 1 For example, if ‘print frame-arguments’ is on, a backtrace can become d34273 1 a34273 1 ‘set-pretty-printer-enabled!’. *Note Guile Pretty Printing API::. d34284 1 a34284 1 Here is an example showing how a ‘std::string’ printer might be d34312 1 a34312 1 object. If not, it returns ‘#f’. d34323 1 a34323 1 An ideal auto-load file will consist solely of ‘import’s of your printer d34336 2 a34337 2 To continue the ‘my::string’ example, this code might appear in ‘(my-project my-library v1)’: d34355 1 a34355 1 multiple data types, then its “subprinters” are the printers for the d34358 1 a34358 1 The ‘(gdb printing)’ module provides a formal way of solving this d34388 1 a34388 1 ‘(gdb printing)’ module. Instead a function is provided to build up the d34405 1 a34405 1 corresponding output of ‘info pretty-printer’: d34420 2 a34421 2 is created with the ‘make-command’ Guile function, and added to GDB with the ‘register-command!’ Guile function. This two-step approach is taken d34423 1 a34423 1 ‘make-command’. d34426 1 a34426 1 consist of multiple lines and are terminated with ‘end’. d34437 1 a34437 1 The result is the ‘’ object representing the command. d34439 1 a34439 1 with ‘register-command!’. d34444 1 a34444 1 and FROM-TTY. The argument SELF is the ‘’ object d34451 1 a34451 1 into a GDB ‘error’ call. Otherwise, the return value is ignored. d34453 1 a34453 1 The argument COMMAND-CLASS is one of the ‘COMMAND_’ constants d34455 1 a34455 1 command in the help system. The default is ‘COMMAND_NONE’. d34457 1 a34457 1 The argument COMPLETER is either ‘#f’, one of the ‘COMPLETE_’ d34460 1 a34460 1 not provided or if the value is ‘#f’, then no completion is d34472 1 a34472 1 Add COMMAND, a ‘’ object, to GDB's list of commands. d34477 2 a34478 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34483 2 a34484 2 by invoking the ‘dont-repeat’ function. This is similar to the user command ‘dont-repeat’, see *note dont-repeat: Define. d34495 1 a34495 1 Throw a ‘gdb:user-error’ exception. The argument MESSAGE is the d34497 1 a34497 1 ‘format’ Scheme function. *Note (guile)Formatted Output::. The d34514 2 a34515 2 If the COMPLETER option to ‘make-command’ is a procedure, it takes three arguments: SELF which is the ‘’ object, and TEXT d34523 1 a34523 1 ‘complete’ command (*note complete: Help.). d34527 1 a34527 1 • If the return value is a list, the contents of the list are d34534 1 a34534 1 • If the return value is a ‘’ object, it is d34536 1 a34536 1 ‘completer-procedure’ to ensure that the results actually do d34540 1 a34540 1 • All other results are treated as though there were no d34548 1 a34548 1 constants defined in the ‘gdb’ module: d34550 1 a34550 1 ‘COMMAND_NONE’ d34555 1 a34555 1 ‘COMMAND_RUNNING’ d34557 2 a34558 2 ‘start’, ‘step’, and ‘continue’ are in this category. Type ‘help running’ at the GDB prompt to see a list of commands in this d34561 3 a34563 3 ‘COMMAND_DATA’ The command is related to data or variables. For example, ‘call’, ‘find’, and ‘print’ are in this category. Type ‘help data’ at the d34566 1 a34566 1 ‘COMMAND_STACK’ d34568 2 a34569 2 ‘backtrace’, ‘frame’, and ‘return’ are in this category. Type ‘help stack’ at the GDB prompt to see a list of commands in this d34572 3 a34574 3 ‘COMMAND_FILES’ This class is used for file-related commands. For example, ‘file’, ‘list’ and ‘section’ are in this category. Type ‘help files’ at d34577 1 a34577 1 ‘COMMAND_SUPPORT’ d34580 2 a34581 2 not related to the state of the inferior. For example, ‘help’, ‘make’, and ‘shell’ are in this category. Type ‘help support’ at d34584 4 a34587 4 ‘COMMAND_STATUS’ The command is an ‘info’-related command, that is, related to the state of GDB itself. For example, ‘info’, ‘macro’, and ‘show’ are in this category. Type ‘help status’ at the GDB prompt to see a d34590 4 a34593 4 ‘COMMAND_BREAKPOINTS’ The command has to do with breakpoints. For example, ‘break’, ‘clear’, and ‘delete’ are in this category. Type ‘help breakpoints’ at the GDB prompt to see a list of commands in this d34596 4 a34599 4 ‘COMMAND_TRACEPOINTS’ The command has to do with tracepoints. For example, ‘trace’, ‘actions’, and ‘tfind’ are in this category. Type ‘help tracepoints’ at the GDB prompt to see a list of commands in this d34602 1 a34602 1 ‘COMMAND_USER’ d34604 2 a34605 2 typically does not fit in one of the other categories. Type ‘help user-defined’ at the GDB prompt to see a list of commands in this d34608 1 a34608 1 ‘COMMAND_OBSCURE’ d34610 2 a34611 2 general interest to users. For example, ‘checkpoint’, ‘fork’, and ‘stop’ are in this category. Type ‘help obscure’ at the GDB prompt d34614 4 a34617 4 ‘COMMAND_MAINTENANCE’ The command is only useful to GDB maintainers. The ‘maintenance’ and ‘flushregs’ commands are in this category. Type ‘help internals’ at the GDB prompt to see a list of commands in this d34622 2 a34623 2 the ‘completer’ procedure. These predefined completion constants are all defined in the ‘gdb’ module: d34625 1 a34625 1 ‘COMPLETE_NONE’ d34628 1 a34628 1 ‘COMPLETE_FILENAME’ d34631 1 a34631 1 ‘COMPLETE_LOCATION’ d34635 1 a34635 1 ‘COMPLETE_COMMAND’ d34639 1 a34639 1 ‘COMPLETE_SYMBOL’ d34643 1 a34643 1 ‘COMPLETE_EXPRESSION’ d34666 1 a34666 1 You can implement new GDB “parameters” using Guile (1). d34669 1 a34669 1 Two examples are: ‘set follow-fork’ and ‘set charset’. Setting these d34674 2 a34675 2 A new parameter is defined with the ‘make-parameter’ Guile function, and added to GDB with the ‘register-parameter!’ Guile function. This d34677 1 a34677 1 parameter to GDB from ‘make-parameter’. d34679 1 a34679 1 Parameters are exposed to the user via the ‘set’ and ‘show’ commands. d34692 3 a34694 3 the ‘set print’ set of parameters. If NAME is ‘print foo’, then ‘print’ will be searched as the prefix parameter. In this case the parameter can subsequently be accessed in GDB as ‘set print foo’. d34698 1 a34698 1 The result is the ‘’ object representing the d34700 1 a34700 1 registered with GDB with ‘register-parameter!’. d34704 1 a34704 1 The argument COMMAND-CLASS should be one of the ‘COMMAND_’ d34707 1 a34707 1 ‘COMMAND_NONE’. d34709 1 a34709 1 The argument PARAMETER-TYPE should be one of the ‘PARAM_’ constants d34712 1 a34712 1 completion. The default is ‘PARAM_BOOLEAN’. d34714 1 a34714 1 If PARAMETER-TYPE is ‘PARAM_ENUM’, then ENUM-LIST must be a list of d34718 1 a34718 1 If PARAMETER-TYPE is not ‘PARAM_ENUM’, then the presence of d34722 1 a34722 1 the ‘’ object representing the parameter. GDB will d34724 1 a34724 1 the ‘set’ API (for example, ‘set foo off’). The value of the d34729 1 a34729 1 function should return ‘""’. A non-empty string result should d34733 1 a34733 1 is the ‘’ object representing the parameter, and d34735 2 a34736 2 GDB will call this function when a PARAMETER's ‘show’ API has been invoked (for example, ‘show foo’). This function must return a d34743 1 a34743 1 The argument SET-DOC is the help text for this parameter's ‘set’ d34746 1 a34746 1 The argument SHOW-DOC is the help text for this parameter's ‘show’ d34751 1 a34751 1 ‘’ object and its result is used as the initial d34756 1 a34756 1 Add PARAMETER, a ‘’ object, to GDB's list of d34761 2 a34762 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34766 1 a34766 1 ‘’ object or a string naming the parameter. d34770 1 a34770 1 must be an object of type ‘’. GDB does validation d34774 1 a34774 1 available types are represented by constants defined in the ‘gdb’ d34777 3 a34779 3 ‘PARAM_BOOLEAN’ The value is a plain boolean. The Guile boolean values, ‘#t’ and ‘#f’ are the only valid values. d34781 2 a34782 2 ‘PARAM_AUTO_BOOLEAN’ The value has three possible states: true, false, and ‘auto’. In d34784 1 a34784 1 ‘auto’ is represented using ‘#:auto’. d34786 3 a34788 3 ‘PARAM_UINTEGER’ The value is an unsigned integer. The value of ‘#:unlimited’ should be interpreted to mean "unlimited", and the value of ‘0’ is d34791 1 a34791 1 ‘PARAM_ZINTEGER’ d34794 1 a34794 1 ‘PARAM_ZUINTEGER’ d34797 3 a34799 3 ‘PARAM_ZUINTEGER_UNLIMITED’ The value is an integer in the range ‘[0, INT_MAX]’. The value of ‘#:unlimited’ means "unlimited", the value of ‘-1’ is reserved and d34802 1 a34802 1 ‘PARAM_STRING’ d34804 1 a34804 1 escape sequences, such as ‘\t’, ‘\f’, and octal escapes, are d34808 1 a34808 1 ‘PARAM_STRING_NOESCAPE’ d34812 2 a34813 2 ‘PARAM_OPTIONAL_FILENAME’ The value is a either a filename (a string), or ‘#f’. d34815 1 a34815 1 ‘PARAM_FILENAME’ d34817 1 a34817 1 ‘PARAM_STRING_NOESCAPE’, but uses file names for completion. d34819 1 a34819 1 ‘PARAM_ENUM’ d34834 1 a34834 1 A program space, or “progspace”, represents a symbolic view of an d34839 1 a34839 1 Each progspace is represented by an instance of the ‘’ d34843 1 a34843 1 ‘(gdb)’ module: d34846 2 a34847 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34850 2 a34851 2 Return ‘#t’ if PROGSPACE is valid, ‘#f’ if not. A ‘’ object can become invalid if the program it d34857 1 a34857 1 ‘#f’. *Note Inferiors Connections and Programs::. d34864 3 a34866 3 the name of the file passed as the argument to the ‘file’ or ‘symbol-file’ commands. If the program space does not have an associated file name, then ‘#f’ is returned. This occurs, for d34869 1 a34869 1 A ‘gdb:invalid-object-error’ exception is thrown if PROGSPACE is d34875 1 a34875 1 ‘’. *Note Objfiles In Guile::. d34877 1 a34877 1 A ‘gdb:invalid-object-error’ exception is thrown if PROGSPACE is d34882 1 a34882 1 an object of type ‘’. *Note Guile Pretty d34887 1 a34887 1 Set the list of registered ‘’ objects for d34901 1 a34901 1 “objfiles”. d34903 1 a34903 1 Each objfile is represented as an object of type ‘’. d34905 1 a34905 1 The following objfile-related procedures are provided by the ‘(gdb)’ d34909 2 a34910 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34913 1 a34913 1 Return ‘#t’ if OBJFILE is valid, ‘#f’ if not. A ‘’ d34915 1 a34915 1 loaded in GDB any longer. All other ‘’ procedures d34924 1 a34924 1 Return the ‘’ that this object file lives in. *Note d34928 1 a34928 1 Return the list of registered ‘’ objects for d34932 1 a34932 1 Set the list of registered ‘’ objects for d34934 1 a34934 1 ‘’ objects. *Note Guile Pretty Printing API::, d34941 1 a34941 1 objfile, this function returns ‘#f’. d34953 2 a34954 2 (*note Stack frames: Frames.). The ‘’ class represents a frame in the stack. A ‘’ object is only valid while its d34956 1 a34956 1 an invalid frame object, GDB will throw a ‘gdb:invalid-object’ exception d34959 2 a34960 2 Two ‘’ objects can be compared for equality with the ‘equal?’ function, like: d34965 1 a34965 1 The following frame-related procedures are provided by the ‘(gdb)’ d34969 2 a34970 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d34973 1 a34973 1 Returns ‘#t’ if FRAME is valid, ‘#f’ if not. A frame object can d34975 1 a34975 1 the inferior. All ‘’ procedures will throw an exception d34979 1 a34979 1 Return the function name of FRAME, or ‘#f’ if it can't be obtained. d34982 1 a34982 1 Return the ‘’ object corresponding to FRAME's d34988 1 a34988 1 ‘NORMAL_FRAME’ d34991 1 a34991 1 ‘DUMMY_FRAME’ d34995 1 a34995 1 ‘INLINE_FRAME’ d34997 1 a34997 1 inlined into a ‘NORMAL_FRAME’ that is older than this one. d34999 1 a34999 1 ‘TAILCALL_FRAME’ d35002 1 a35002 1 ‘SIGTRAMP_FRAME’ d35006 1 a35006 1 ‘ARCH_FRAME’ d35009 2 a35010 2 ‘SENTINEL_FRAME’ This is like ‘NORMAL_FRAME’, but it is only used for the d35016 1 a35016 1 ‘unwind-stop-reason-string’ to convert the value returned by this d35019 1 a35019 1 ‘FRAME_UNWIND_NO_REASON’ d35022 1 a35022 1 ‘FRAME_UNWIND_NULL_ID’ d35025 1 a35025 1 ‘FRAME_UNWIND_OUTERMOST’ d35028 1 a35028 1 ‘FRAME_UNWIND_UNAVAILABLE’ d35032 1 a35032 1 ‘FRAME_UNWIND_INNER_ID’ d35037 1 a35037 1 ‘FRAME_UNWIND_SAME_ID’ d35044 1 a35044 1 ‘FRAME_UNWIND_NO_SAVED_PC’ d35048 1 a35048 1 ‘FRAME_UNWIND_MEMORY_ERROR’ d35052 1 a35052 1 ‘FRAME_UNWIND_FIRST_ERROR’ d35068 1 a35068 1 Return the frame's code block as a ‘’ object. *Note d35073 1 a35073 1 ‘’ object, or ‘#f’ if there isn't one. *Note Symbols d35083 1 a35083 1 Return the frame's ‘’ (symtab and line) object. *Note d35088 1 a35088 1 string, like ‘pc’. d35095 2 a35096 2 given as a string or a ‘’ object, and BLOCK must be a ‘’ object. d35112 1 a35112 1 ‘frame-unwind-stop-reason’ procedure above in this section). d35122 1 a35122 1 represented individually in Guile as an object of type ‘’. d35128 1 a35128 1 The outermost block is known as the “global block”. The global block d35131 1 a35131 1 The block nested just inside the global block is the “static block”. d35166 1 a35166 1 The following block-related procedures are provided by the ‘(gdb)’ d35170 2 a35171 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d35174 1 a35174 1 Returns ‘#t’ if ‘’ BLOCK is valid, ‘#f’ if not. A block d35176 1 a35176 1 anymore in the inferior. All other ‘’ methods will d35182 1 a35182 1 Return the start address of ‘’ BLOCK. d35185 1 a35185 1 Return the end address of ‘’ BLOCK. d35188 2 a35189 2 Return the name of ‘’ BLOCK represented as a ‘’ object. If the block is not named, then ‘#f’ is d35198 2 a35199 2 Return the block containing ‘’ BLOCK. If the parent block does not exist, then ‘#f’ is returned. d35202 1 a35202 1 Return the global block associated with ‘’ BLOCK. d35205 1 a35205 1 Return the static block associated with ‘’ BLOCK. d35208 2 a35209 2 Return ‘#t’ if ‘’ BLOCK is a global block. Otherwise return ‘#f’. d35212 2 a35213 2 Return ‘#t’ if ‘’ BLOCK is a static block. Otherwise return ‘#f’. d35217 1 a35217 1 ‘’ BLOCK. d35220 1 a35220 1 Return an object of type ‘’ that will iterate over d35228 2 a35229 2 This object would be obtained from the ‘progress’ element of the ‘’ object returned by ‘make-block-symbols-iterator’. d35232 1 a35232 1 Return the innermost ‘’ containing the given PC value. d35234 1 a35234 1 function will return ‘#f’. d35244 1 a35244 1 these symbols in GDB with the ‘’ object. d35246 1 a35246 1 The following symbol-related procedures are provided by the ‘(gdb)’ d35250 2 a35251 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35254 3 a35256 3 Return ‘#t’ if the ‘’ object is valid, ‘#f’ if not. A ‘’ object can become invalid if the symbol it refers to does not exist in GDB any longer. All other ‘’ d35261 2 a35262 2 Return the type of SYMBOL or ‘#f’ if no type is recorded. The result is an object of type ‘’. *Note Types In Guile::. d35266 1 a35266 1 object of type ‘’. *Note Symbol Tables In Guile::. d35281 1 a35281 1 either ‘name’ or ‘linkage_name’, depending on whether the user d35287 1 a35287 1 defined in the ‘(gdb)’ module and described later in this chapter. d35290 2 a35291 2 Return ‘#t’ if evaluating SYMBOL's value requires a frame (*note Frames In Guile::) and ‘#f’ otherwise. Typically, local variables d35295 2 a35296 2 Return ‘#t’ if SYMBOL is an argument of a function. Otherwise return ‘#f’. d35299 1 a35299 1 Return ‘#t’ if SYMBOL is a constant. Otherwise return ‘#f’. d35302 2 a35303 2 Return ‘#t’ if SYMBOL is a function or a method. Otherwise return ‘#f’. d35306 1 a35306 1 Return ‘#t’ if SYMBOL is a variable. Otherwise return ‘#f’. d35309 1 a35309 1 Compute the value of SYMBOL, as a ‘’. For functions, d35323 1 a35323 1 BLOCK. The BLOCK argument must be a ‘’ object. If d35326 1 a35326 1 DOMAIN argument must be a domain constant defined in the ‘(gdb)’ d35330 4 a35333 4 ‘’ object or ‘#f’ if the symbol is not found. If the symbol is found, the second element is ‘#t’ if the symbol is a field of a method's object (e.g., ‘this’ in C++), otherwise it is ‘#f’. If the symbol is not found, the second element is ‘#f’. d35341 1 a35341 1 DOMAIN argument must be a domain constant defined in the ‘(gdb)’ d35344 1 a35344 1 The result is a ‘’ object or ‘#f’ if the symbol is not d35347 2 a35348 2 The available domain categories in ‘’ are represented as constants in the ‘(gdb)’ module: d35350 1 a35350 1 ‘SYMBOL_UNDEF_DOMAIN’ d35355 1 a35355 1 ‘SYMBOL_VAR_DOMAIN’ d35359 1 a35359 1 ‘SYMBOL_FUNCTION_DOMAIN’ d35362 1 a35362 1 ‘SYMBOL_TYPE_DOMAIN’ d35364 1 a35364 1 tag (the name appearing after a ‘struct’, ‘union’, or ‘enum’ d35368 1 a35368 1 ‘SYMBOL_STRUCT_DOMAIN’ d35373 2 a35374 2 Here ‘type_one’ will be in ‘SYMBOL_STRUCT_DOMAIN’, but ‘type_two’ will be in ‘SYMBOL_TYPE_DOMAIN’. d35376 1 a35376 1 ‘SYMBOL_LABEL_DOMAIN’ d35379 2 a35380 2 ‘SYMBOL_VARIABLES_DOMAIN’ This domain holds a subset of the ‘SYMBOLS_VAR_DOMAIN’; it contains d35383 1 a35383 1 ‘SYMBOL_FUNCTIONS_DOMAIN’ d35386 1 a35386 1 ‘SYMBOL_TYPES_DOMAIN’ d35389 2 a35390 2 The available address class categories in ‘’ are represented as constants in the ‘gdb’ module: d35396 3 a35398 3 each named after one of the preceding constants, but with the ‘SEARCH’ prefix replacing the ‘SYMBOL’ prefix; for example, ‘SEARCH_LABEL_DOMAIN’. These may be or'd together to form a search d35401 1 a35401 1 ‘SYMBOL_LOC_UNDEF’ d35405 1 a35405 1 ‘SYMBOL_LOC_CONST’ d35408 1 a35408 1 ‘SYMBOL_LOC_STATIC’ d35411 1 a35411 1 ‘SYMBOL_LOC_REGISTER’ d35414 1 a35414 1 ‘SYMBOL_LOC_ARG’ d35418 1 a35418 1 ‘SYMBOL_LOC_REF_ARG’ d35420 1 a35420 1 ‘LOC_ARG’ except that the value's address is stored at the offset, d35423 2 a35424 2 ‘SYMBOL_LOC_REGPARM_ADDR’ Value is a specified register. Just like ‘LOC_REGISTER’ except the d35428 1 a35428 1 ‘SYMBOL_LOC_LOCAL’ d35431 2 a35432 2 ‘SYMBOL_LOC_TYPEDEF’ Value not used. Symbols in the domain ‘SYMBOL_STRUCT_DOMAIN’ all d35435 1 a35435 1 ‘SYMBOL_LOC_BLOCK’ d35438 1 a35438 1 ‘SYMBOL_LOC_CONST_BYTES’ d35441 1 a35441 1 ‘SYMBOL_LOC_UNRESOLVED’ d35446 1 a35446 1 ‘SYMBOL_LOC_OPTIMIZED_OUT’ d35449 1 a35449 1 ‘SYMBOL_LOC_COMPUTED’ d35459 3 a35461 3 to Guile via two objects: ‘’ (symtab-and-line) and ‘’. Symbol table and line data for a frame is returned from the ‘frame-find-sal’ ‘’ procedure. *Note Frames In Guile::. d35466 1 a35466 1 The following symtab-related procedures are provided by the ‘(gdb)’ d35470 2 a35471 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35474 3 a35476 3 Return ‘#t’ if the ‘’ object is valid, ‘#f’ if not. A ‘’ object becomes invalid when the symbol table it refers to no longer exists in GDB. All other ‘’ d35499 1 a35499 1 ‘(gdb)’ module: d35502 2 a35503 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35506 1 a35506 1 Return ‘#t’ if SAL is valid, ‘#f’ if not. A ‘’ object d35508 1 a35508 1 exists in GDB. All other ‘’ procedures will throw an d35512 1 a35512 1 Return the symbol table object (‘’) for SAL. d35524 3 a35526 3 Return the ‘’ object corresponding to the PC value. If an invalid value of PC is passed as an argument, then the ‘symtab’ and ‘line’ attributes of the returned ‘’ object will be ‘#f’ d35536 3 a35538 3 ‘’. New breakpoints can be created with the ‘make-breakpoint’ Guile function, and then added to GDB with the ‘register-breakpoint!’ Guile function. This two-step approach is taken d35540 1 a35540 1 ‘make-breakpoint’. d35546 1 a35546 1 ‘(gdb)’ module: d35553 2 a35554 2 contents can be any location recognized by the ‘break’ command, or in the case of a watchpoint, by the ‘watch’ command. d35556 1 a35556 1 The breakpoint is initially marked as ‘invalid’. The breakpoint is d35558 2 a35559 2 ‘register-breakpoint!’, at which point it becomes ‘valid’. The result is the ‘’ object representing the d35563 2 a35564 2 can be either ‘BP_BREAKPOINT’ or ‘BP_WATCHPOINT’, and defaults to ‘BP_BREAKPOINT’. d35567 2 a35568 2 create, if TYPE is ‘BP_WATCHPOINT’. If a watchpoint class is not provided, it is assumed to be a ‘WP_WRITE’ class. d35572 2 a35573 2 when registered, nor will it be listed in the output from ‘info breakpoints’ (but will be listed with the ‘maint info breakpoints’ d35580 1 a35580 1 it may be re-registered with ‘register-breakpoint!’). d35584 4 a35587 4 changed from ‘BP_WATCHPOINT’ to ‘BP_HARDWARE_WATCHPOINT’ for ‘WP_WRITE’, ‘BP_READ_WATCHPOINT’ for ‘WP_READ’, and ‘BP_ACCESS_WATCHPOINT’ for ‘WP_ACCESS’. If not successful, the type of the watchpoint is left as ‘WP_WATCHPOINT’. d35590 1 a35590 1 ‘gdb’ module: d35592 1 a35592 1 ‘BP_BREAKPOINT’ d35595 1 a35595 1 ‘BP_WATCHPOINT’ d35598 1 a35598 1 ‘BP_HARDWARE_WATCHPOINT’ d35602 1 a35602 1 ‘BP_READ_WATCHPOINT’ d35606 1 a35606 1 ‘BP_ACCESS_WATCHPOINT’ d35610 1 a35610 1 ‘BP_CATCHPOINT’ d35615 1 a35615 1 in the ‘(gdb)’ module: d35617 1 a35617 1 ‘WP_READ’ d35620 1 a35620 1 ‘WP_WRITE’ d35623 1 a35623 1 ‘WP_ACCESS’ d35627 1 a35627 1 Add BREAKPOINT, a ‘’ object, to GDB's list of d35629 1 a35629 1 ‘make-breakpoint’. One cannot register breakpoints that have been d35631 1 a35631 1 becomes ‘valid’. It is an error to register an already registered d35639 1 a35639 1 If BREAKPOINT was created from Guile with ‘make-breakpoint’ it may d35645 1 a35645 1 ‘’ object. d35648 1 a35648 1 Return ‘#t’ if OBJECT is a ‘’ object, and ‘#f’ d35652 4 a35655 4 Return ‘#t’ if BREAKPOINT is valid, ‘#f’ otherwise. Breakpoints created with ‘make-breakpoint’ are marked as invalid until they are registered with GDB with ‘register-breakpoint!’. A ‘’ object can become invalid if the user deletes d35666 1 a35666 1 Return ‘#t’ if the breakpoint was created as a temporary d35669 1 a35669 1 other than ‘breakpoint-valid?’ and ‘register-breakpoint!’, will d35678 2 a35679 2 Return ‘#t’ if the breakpoint is visible to the user when hit, or when the ‘info breakpoints’ command is run. Otherwise return ‘#f’. d35684 1 a35684 1 is, it is a watchpoint) return ‘#f’. d35689 1 a35689 1 breakpoint is not a watchpoint) return ‘#f’. d35692 1 a35692 1 Return ‘#t’ if the breakpoint is enabled, and ‘#f’ otherwise. d35695 1 a35695 1 Set the enabled state of BREAKPOINT to FLAG. If flag is ‘#f’ it is d35699 1 a35699 1 Return ‘#t’ if the breakpoint is silent, and ‘#f’ otherwise. d35702 2 a35703 2 the first command is ‘silent’. This is not reported by the ‘silent’ attribute. d35706 1 a35706 1 Set the silent state of BREAKPOINT to FLAG. If flag is ‘#f’ the d35730 1 a35730 1 ‘#f’, the breakpoint is no longer thread-specific. d35735 1 a35735 1 not Ada), return ‘#f’. d35738 1 a35738 1 Set the Ada task of BREAKPOINT to TASK. If set to ‘#f’, the d35743 1 a35743 1 is a string. If there is no condition, return ‘#f’. d35747 1 a35747 1 string. If set to ‘#f’ then the breakpoint becomes unconditional. d35751 1 a35751 1 ‘set-breakpoint-stop!’ below in this section. d35757 1 a35757 1 reaches this breakpoint. If it returns ‘#t’, or any non-‘#f’ d35762 2 a35763 2 ‘stop’ predicate, each one will be called regardless of the return status of the previous. This ensures that all ‘stop’ predicates d35765 1 a35765 1 of the methods returns ‘#t’ but the others return ‘#f’, the d35774 1 a35774 1 Example ‘stop’ implementation: d35784 1 a35784 1 Return the commands attached to BREAKPOINT as a string, or ‘#f’ if d35793 1 a35793 1 A “lazy string” is a string whose contents is not retrieved or encoded d35796 3 a35798 3 A ‘’ is represented in GDB as an ‘address’ that points to a region of memory, an ‘encoding’ that will be used to encode that region of memory, and a ‘length’ to delimit the region of memory d35800 4 a35803 4 ‘’ and a string wrapped within a ‘’ is that a ‘’ will be treated differently by GDB when printing. A ‘’ is retrieved and encoded during printing, while a ‘’ wrapping a string is immediately retrieved and encoded on d35807 1 a35807 1 ‘(gdb)’ module: d35810 2 a35811 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35830 1 a35830 1 the lazy string's character type, use ‘type-target-type’. *Note d35834 1 a35834 1 Convert the ‘’ to a ‘’. This value d35837 1 a35837 1 ‘’. d35847 1 a35847 1 of the ‘’ class. d35850 1 a35850 1 ‘(gdb)’ module: d35853 2 a35854 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d35857 1 a35857 1 Return the current architecture as a ‘’ object. d35860 1 a35860 1 Return the name (string value) of ‘’ ARCH. d35863 1 a35863 1 Return name of target character set of ‘’ ARCH. d35866 1 a35866 1 Return name of target wide character set of ‘’ ARCH. d35872 1 a35872 1 Return the ‘’ object for a ‘void’ type of architecture d35876 1 a35876 1 Return the ‘’ object for a ‘char’ type of architecture d35880 1 a35880 1 Return the ‘’ object for a ‘short’ type of architecture d35884 1 a35884 1 Return the ‘’ object for an ‘int’ type of architecture d35888 1 a35888 1 Return the ‘’ object for a ‘long’ type of architecture d35892 1 a35892 1 Return the ‘’ object for a ‘signed char’ type of d35896 1 a35896 1 Return the ‘’ object for an ‘unsigned char’ type of d35900 1 a35900 1 Return the ‘’ object for an ‘unsigned short’ type of d35904 1 a35904 1 Return the ‘’ object for an ‘unsigned int’ type of d35908 1 a35908 1 Return the ‘’ object for an ‘unsigned long’ type of d35912 1 a35912 1 Return the ‘’ object for a ‘float’ type of architecture d35916 1 a35916 1 Return the ‘’ object for a ‘double’ type of architecture d35920 1 a35920 1 Return the ‘’ object for a ‘long double’ type of d35924 1 a35924 1 Return the ‘’ object for a ‘bool’ type of architecture d35928 1 a35928 1 Return the ‘’ object for a ‘long long’ type of d35932 1 a35932 1 Return the ‘’ object for an ‘unsigned long long’ type of d35936 1 a35936 1 Return the ‘’ object for an ‘int8’ type of architecture d35940 1 a35940 1 Return the ‘’ object for a ‘uint8’ type of architecture d35944 1 a35944 1 Return the ‘’ object for an ‘int16’ type of architecture d35948 1 a35948 1 Return the ‘’ object for a ‘uint16’ type of architecture d35952 1 a35952 1 Return the ‘’ object for an ‘int32’ type of architecture d35956 1 a35956 1 Return the ‘’ object for a ‘uint32’ type of architecture d35960 1 a35960 1 Return the ‘’ object for an ‘int64’ type of architecture d35964 1 a35964 1 Return the ‘’ object for a ‘uint64’ type of architecture d35988 1 a35988 1 from. If PORT is ‘#f’ then bytes are read from target memory. d35992 1 a35992 1 specifies a ‘bytevector’ and you want the bytevector to be d36024 1 a36024 1 ‘address’ d36028 1 a36028 1 ‘asm’ d36032 1 a36032 1 specified by the current CLI variable ‘disassembly-flavor’. d36035 1 a36035 1 ‘length’ d36055 1 a36055 1 Return ‘#t’ if OBJECT is a GDB stdio port. Otherwise return ‘#f’. d36063 1 a36063 1 GDB provides a ‘port’ interface to target memory. This allows Guile d36065 1 a36065 1 functionality. The main routine is ‘open-memory’ which returns a port d36073 4 a36076 4 ‘"a"’ and ‘"l"’ modes are not supported. *Note (guile)File Ports::. The ‘"b"’ (binary) character may be present, but is ignored: memory ports are binary only. If ‘"0"’ is appended then the port is marked as unbuffered. The default is ‘"r"’, read-only d36087 2 a36088 2 Return ‘#t’ if OBJECT is an object of type ‘’. Otherwise return ‘#f’. d36091 2 a36092 2 Return the range of ‘’ MEMORY-PORT as a list of two elements: ‘(start end)’. The range is START to END inclusive. d36095 1 a36095 1 Return the size of the read buffer of ‘’ d36102 1 a36102 1 Set the size of the read buffer of ‘’ MEMORY-PORT d36106 2 a36107 2 GDB is built with Guile 2.2 or later, you can call ‘setvbuf’ instead (*note ‘setvbuf’: (guile)Buffering.). d36110 1 a36110 1 Return the size of the write buffer of ‘’ d36118 1 a36118 1 Set the size of the write buffer of ‘’ MEMORY-PORT d36122 1 a36122 1 GDB is built with Guile 2.2 or later, you can call ‘setvbuf’ d36125 1 a36125 1 A memory port is closed like any other port, with ‘close-port’. d36127 1 a36127 1 Combined with Guile's ‘bytevectors’, memory ports provide a lot of d36158 1 a36158 1 A ‘’ object is constructed with the ‘make-iterator’ d36165 4 a36168 4 ‘(end-of-iteration)’, and may be tested with the ‘end-of-iteration?’ predicate. The result of ‘(end-of-iteration)’ is chosen so that it is not otherwise used by the ‘(gdb)’ module. If you are using ‘’ in your own code it is your d36186 1 a36186 1 all the functions in ‘my-global-block’. d36196 2 a36197 2 Return ‘#t’ if OBJECT is a ‘’ object. Otherwise return ‘#f’. d36200 1 a36200 1 Return the first argument that was passed to ‘make-iterator’. This d36211 1 a36211 1 ‘make-iterator’, passing it one argument, the ‘’ d36213 2 a36214 2 an end marker as implemented by the ‘next!’ procedure. By convention the end marker is the result of ‘(end-of-iteration)’. d36220 2 a36221 2 Return ‘#t’ if OBJECT is the end of iteration marker. Otherwise return ‘#f’. d36223 1 a36223 1 These functions are provided by the ‘(gdb iterator)’ module to assist d36227 1 a36227 1 Return a ‘’ object that will iterate over LIST. d36245 2 a36246 2 Run ITERATOR until the result of ‘(pred element)’ is true and return that as the result. Otherwise return ‘#f’. d36254 1 a36254 1 When a new object file is read (for example, due to the ‘file’ command, d36256 2 a36257 2 Guile support scripts in two ways: ‘OBJFILE-gdb.scm’ and the ‘.debug_gdb_scripts’ section. *Note Auto-loading extensions::. d36265 1 a36265 1 ‘set auto-load guile-scripts [on|off]’ d36268 1 a36268 1 ‘show auto-load guile-scripts’ d36271 1 a36271 1 ‘info auto-load guile-scripts [REGEXP]’ d36275 1 a36275 1 the ‘.debug_gdb_scripts’ section and were not found. This is d36291 2 a36292 2 When reading an auto-loaded file, GDB sets the “current objfile”. This is available via the ‘current-objfile’ procedure (*note Objfiles In d36324 1 a36324 1 The OBJECT must either be a ‘’ object, or ‘#f’ in d36329 1 a36329 1 The OBJECT must either be a ‘’ object, or ‘#f’ in d36339 1 a36339 1 ‘’ objects. d36365 3 a36367 3 Return ‘#t’ if TYPE, assumed to be a type with fields (e.g., a structure or union), has field FIELD. Otherwise return ‘#f’. This searches baseclasses, whereas ‘type-has-field?’ does not. d36371 1 a36371 1 hash table are referenced with ‘hashq-ref’. d36380 5 a36384 5 new object file is read (for example, due to the ‘file’ command, or because the inferior has loaded a shared library): ‘OBJFILE-gdb.EXT’ (*note The ‘OBJFILE-gdb.EXT’ file: objfile-gdbdotext file.) and the ‘.debug_gdb_scripts’ section of modern file formats like ELF (*note The ‘.debug_gdb_scripts’ section: dotdebug_gdb_scripts section.). For a d36392 1 a36392 1 scripts can be printed. See the ‘auto-loading’ section of each d36398 1 a36398 1 configured ‘auto-load safe-path’ (*note Auto-loading safe path::). d36402 2 a36403 2 * objfile-gdbdotext file:: The ‘OBJFILE-gdb.EXT’ file * dotdebug_gdb_scripts section:: The ‘.debug_gdb_scripts’ section d36409 1 a36409 1 23.5.1 The ‘OBJFILE-gdb.EXT’ file d36413 1 a36413 1 ‘OBJFILE-gdb.EXT’ (we call it SCRIPT-NAME below), where OBJFILE is the d36417 1 a36417 1 ‘OBJFILE-gdb.gdb’ d36419 1 a36419 1 ‘OBJFILE-gdb.py’ d36421 1 a36421 1 ‘OBJFILE-gdb.scm’ d36425 2 a36426 2 absolute, following all symlinks, and resolving ‘.’ and ‘..’ components, and appending the ‘-gdb.EXT’ suffix. If this file exists and is d36433 2 a36434 2 a one-letter subdirectory, i.e. ‘d:/usr/bin/’ is converted to ‘/d/usr/bin/’, because Windows filesystems disallow colons in file d36438 1 a36438 1 ‘auto-load safe-path’ (*note Auto-loading safe path::). d36440 2 a36441 2 For object files using ‘.exe’ suffix GDB tries to load first the scripts normally according to its ‘.exe’ filename. But if no scripts d36443 1 a36443 1 without its ‘.exe’ suffix. This ‘.exe’ stripping is case insensitive d36447 1 a36447 1 ‘set auto-load scripts-directory [DIRECTORIES]’ d36450 1 a36450 1 (‘:’ on Unix, ‘;’ on MS-Windows and MS-DOS). d36453 1 a36453 1 ‘set auto-load safe-path’ (*note set auto-load safe-path::). d36455 3 a36457 3 This variable defaults to ‘$debugdir:$datadir/auto-load’. The default ‘set auto-load safe-path’ value can be also overridden by GDB configuration option ‘--with-auto-load-dir’. d36459 1 a36459 1 Any reference to ‘$debugdir’ will get replaced by d36461 4 a36464 4 reference to ‘$datadir’ will get replaced by DATA-DIRECTORY which is determined at GDB startup (*note Data Files::). ‘$debugdir’ and ‘$datadir’ must be placed as a directory component -- either alone or delimited by ‘/’ or ‘\’ directory separators, depending on the d36467 3 a36469 3 The list of directories uses path separator (‘:’ on GNU and Unix systems, ‘;’ on MS-Windows and MS-DOS) to separate directories, similarly to the ‘PATH’ environment variable. d36471 1 a36471 1 ‘show auto-load scripts-directory’ d36474 1 a36474 1 ‘add-auto-load-scripts-directory [DIRECTORIES...]’ d36481 1 a36481 1 is opened. So your ‘-gdb.EXT’ file should be careful to avoid errors if d36487 1 a36487 1 23.5.2 The ‘.debug_gdb_scripts’ section d36492 1 a36492 1 ‘.debug_gdb_scripts’. If this section exists, its contents is a list of d36496 1 a36496 1 ‘.debug_gdb_scripts’. d36500 4 a36503 4 ‘SECTION_SCRIPT_ID_PYTHON_FILE = 1’ ‘SECTION_SCRIPT_ID_SCHEME_FILE = 3’ ‘SECTION_SCRIPT_ID_PYTHON_TEXT = 4’ ‘SECTION_SCRIPT_ID_SCHEME_TEXT = 6’ d36510 1 a36510 1 Specifying Source Directories: Source Path.), except that ‘$cdir’ is not d36513 1 a36513 1 File entries can be placed in section ‘.debug_gdb_scripts’ with, for d36525 1 a36525 1 For Guile scripts, replace ‘.byte 1’ with ‘.byte 3’. Then one can d36533 1 a36533 1 configured ‘auto-load safe-path’ (*note Auto-loading safe path::). d36537 1 a36537 1 and with the use of ‘"MS"’ attributes on the section, the linker will d36545 1 a36545 1 everything after the prefix byte and up to the first newline (‘0xa’) d36552 1 a36552 1 Here is an example from file ‘py-section-script.c’ in the GDB d36572 4 a36575 4 Loading of inlined scripts requires a properly configured ‘auto-load safe-path’ (*note Auto-loading safe path::). The path to specify in ‘auto-load safe-path’ is the path of the file containing the ‘.debug_gdb_scripts’ section. d36586 1 a36586 1 Benefits of the ‘-gdb.EXT’ way: d36588 1 a36588 1 • Can be used with file formats that don't support multiple sections. d36590 1 a36590 1 • Ease of finding scripts for public libraries. d36592 1 a36592 1 Scripts specified in the ‘.debug_gdb_scripts’ section are searched d36594 1 a36594 1 e.g., ‘libstdc++’, there typically isn't a source directory in d36597 1 a36597 1 • Doesn't require source code additions. d36599 1 a36599 1 Benefits of the ‘.debug_gdb_scripts’ way: d36601 1 a36601 1 • Works with static linking. d36603 1 a36603 1 Scripts for libraries done the ‘-gdb.EXT’ way require an objfile to d36607 1 a36607 1 executable's ‘-gdb.EXT’ script. d36609 1 a36609 1 • Works with classes that are entirely inlined. d36612 1 a36612 1 associated shared library to attach a ‘-gdb.EXT’ script to. d36614 1 a36614 1 • Scripts needn't be copied out of the source tree. d36618 1 a36618 1 install the ‘-gdb.EXT’ scripts in a place where GDB can find them d36620 1 a36620 1 ‘.debug_gdb_scripts’ section as relative paths, and add a path to d36664 1 a36664 1 the ‘-i’ or ‘--interpreter’ startup options. Defined interpreters d36667 1 a36667 1 ‘console’ d36672 1 a36672 1 ‘dap’ d36680 2 a36681 2 ‘mi’ The newest GDB/MI interface (currently ‘mi3’). Used primarily by d36685 1 a36685 1 ‘mi3’ d36688 1 a36688 1 ‘mi2’ d36693 1 a36693 1 console interpreter, simply use the ‘interpreter-exec’ command: d36700 1 a36700 1 Note that ‘interpreter-exec’ only changes the interpreter for the d36717 2 a36718 2 To start a new secondary “user interface” running MI, use the ‘new-ui’ command: d36723 2 a36724 2 accepts the same values as the ‘interpreter-exec’ command. For example, ‘console’, ‘mi’, ‘mi2’, etc. The TTY parameter specifies the name of d36730 1 a36730 1 runs an MI interpreter on ‘/dev/pts/9’. d36739 1 a36739 1 ‘curses’ library to show the source file, the assembly output, the d36742 1 a36742 1 ‘curses’ library is available. d36744 1 a36744 1 The TUI mode is enabled by default when you invoke GDB as ‘gdb -tui’. d36746 2 a36747 2 various TUI commands and key bindings, such as ‘tui enable’ or ‘C-x C-a’. *Note TUI Commands: TUI Commands, and *note TUI Key Bindings: TUI d36783 1 a36783 1 highlighting the current line and marking it with a ‘>’ marker. By d36785 2 a36786 2 highlighted text, but you can enable it with the ‘set style tui-current-position on’ command. *Note Output Styling::. d36791 1 a36791 1 ‘B’ d36794 1 a36794 1 ‘b’ d36797 1 a36797 1 ‘H’ d36800 1 a36800 1 ‘h’ d36805 1 a36805 1 ‘+’ d36808 1 a36808 1 ‘-’ d36819 1 a36819 1 • source only, d36821 1 a36821 1 • assembly only, d36823 1 a36823 1 • source and assembly, d36825 1 a36825 1 • source and registers, or d36827 1 a36827 1 • assembly and registers. d36840 1 a36840 1 being debugged, this field is set to ‘No process’. d36849 1 a36849 1 counter, the string ‘??’ is displayed. d36853 1 a36853 1 current line number is not known, the string ‘??’ is displayed. d36868 3 a36870 3 ‘C-x C-a’ ‘C-x a’ ‘C-x A’ d36878 1 a36878 1 ‘tui-switch-mode’. d36880 1 a36880 1 ‘C-x 1’ d36882 1 a36882 1 ‘source’ or ‘assembly’. When the TUI mode is not active, it will d36885 1 a36885 1 Think of this key binding as the Emacs ‘C-x 1’ binding. d36888 1 a36888 1 ‘tui-delete-other-windows’. d36890 1 a36890 1 ‘C-x 2’ d36896 1 a36896 1 Think of it as the Emacs ‘C-x 2’ binding. d36899 1 a36899 1 ‘tui-change-windows’. d36901 1 a36901 1 ‘C-x o’ d36906 1 a36906 1 Think of it as the Emacs ‘C-x o’ binding. d36909 1 a36909 1 ‘tui-other-window’. d36911 1 a36911 1 ‘C-x s’ d36915 1 a36915 1 This key binding uses the bindable Readline function ‘next-keymap’. d36937 1 a36937 1 ‘C-L’ d36943 1 a36943 1 readline key bindings such as ‘C-p’, ‘C-n’, ‘C-b’ and ‘C-f’ to control d36952 2 a36953 2 The TUI also provides a “SingleKey” mode, which binds several frequently used GDB commands to single keys. Type ‘C-x s’ to switch into this d36956 1 a36956 1 ‘c’ d36959 1 a36959 1 ‘C’ d36962 1 a36962 1 ‘d’ d36965 1 a36965 1 ‘f’ d36968 1 a36968 1 ‘F’ d36971 1 a36971 1 ‘n’ d36974 1 a36974 1 ‘N’ d36977 2 a36978 2 ‘o’ nexti. The shortcut letter ‘o’ stands for "step Over". d36980 1 a36980 1 ‘O’ d36983 1 a36983 1 ‘q’ d36986 1 a36986 1 ‘r’ d36989 1 a36989 1 ‘s’ d36992 1 a36992 1 ‘S’ d36995 2 a36996 2 ‘i’ stepi. The shortcut letter ‘i’ stands for "step Into". d36998 1 a36998 1 ‘I’ d37001 1 a37001 1 ‘u’ d37004 1 a37004 1 ‘v’ d37007 1 a37007 1 ‘w’ d37014 2 a37015 2 restored. The only way to permanently leave this mode is by typing ‘q’ or ‘C-x s’. d37018 1 a37018 1 will be named ‘SingleKey’. This can be used in ‘.inputrc’ to add d37041 1 a37041 1 off the ‘tui mouse-events’ setting (*note set tui mouse-events: d37058 1 a37058 1 Note that if GDB's ‘stdout’ is not connected to a terminal, or GDB d37064 1 a37064 1 ‘tui enable’ d37069 1 a37069 1 ‘tui disable’ d37072 1 a37072 1 ‘info win’ d37075 1 a37075 1 ‘tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT...]’ d37077 1 a37077 1 can be accessed using the ‘layout’ command (see below). d37084 1 a37084 1 ‘focus’ command (see below); additionally, the ‘status’ window can d37087 1 a37087 1 conventional to use ‘0’ here. d37089 2 a37090 2 A window description looks a bit like an invocation of ‘tui new-layout’, and is of the form {[‘-horizontal’]WINDOW WEIGHT d37093 1 a37093 1 This specifies a sub-layout. If ‘-horizontal’ is given, the d37105 1 a37105 1 Here, the new layout is called ‘example’. It shows the source and d37121 2 a37122 2 ‘tui layout NAME’ ‘layout NAME’ d37126 1 a37126 1 using ‘tui new-layout’. d37130 1 a37130 1 ‘next’ d37133 1 a37133 1 ‘prev’ d37136 1 a37136 1 ‘src’ d37139 1 a37139 1 ‘asm’ d37142 1 a37142 1 ‘split’ d37145 3 a37147 3 ‘regs’ When in ‘src’ layout display the register, source, and command windows. When in ‘asm’ or ‘split’ layout display the d37150 2 a37151 2 ‘tui focus NAME’ ‘focus NAME’ d37155 1 a37155 1 ‘next’ d37158 1 a37158 1 ‘prev’ d37161 1 a37161 1 ‘src’ d37164 1 a37164 1 ‘asm’ d37167 1 a37167 1 ‘regs’ d37170 1 a37170 1 ‘cmd’ d37173 3 a37175 3 ‘tui refresh’ ‘refresh’ Refresh the screen. This is similar to typing ‘C-L’. d37177 1 a37177 1 ‘tui reg GROUP’ d37183 1 a37183 1 ‘next’ d37187 1 a37187 1 ‘prev’ d37192 1 a37192 1 ‘general’ d37194 1 a37194 1 ‘float’ d37196 1 a37196 1 ‘system’ d37198 1 a37198 1 ‘vector’ d37200 1 a37200 1 ‘all’ d37203 1 a37203 1 ‘update’ d37206 4 a37209 4 ‘tui window height NAME +COUNT’ ‘tui window height NAME -COUNT’ ‘winheight NAME +COUNT’ ‘winheight NAME -COUNT’ d37214 1 a37214 1 ‘info win’ (*note info win: info_win_command.). d37221 4 a37224 4 ‘tui window width NAME +COUNT’ ‘tui window width NAME -COUNT’ ‘winwidth NAME +COUNT’ ‘winwidth NAME -COUNT’ d37229 1 a37229 1 ‘info win’ (*note info win: info_win_command.). d37244 1 a37244 1 ‘set tui border-kind KIND’ d37247 1 a37247 1 ‘space’ d37250 2 a37251 2 ‘ascii’ Use ASCII characters ‘+’, ‘-’ and ‘|’ to draw the border. d37253 1 a37253 1 ‘acs’ d37258 2 a37259 2 ‘set tui border-mode MODE’ ‘set tui active-border-mode MODE’ d37263 1 a37263 1 ‘normal’ d37266 1 a37266 1 ‘standout’ d37269 1 a37269 1 ‘reverse’ d37272 1 a37272 1 ‘half’ d37275 1 a37275 1 ‘half-standout’ d37278 1 a37278 1 ‘bold’ d37281 1 a37281 1 ‘bold-standout’ d37284 1 a37284 1 ‘set tui tab-width NCHARS’ d37289 1 a37289 1 ‘set tui compact-source [on|off]’ d37295 1 a37295 1 ‘set tui mouse-events [on|off]’ d37300 1 a37300 1 ‘set debug tui [on|off]’ d37304 1 a37304 1 ‘show debug tui’ d37309 1 a37309 1 appropriate ‘set style’ commands. *Note Output Styling::. d37320 1 a37320 1 To use this interface, use the command ‘M-x gdb’ in Emacs. Give the d37328 1 a37328 1 • All "terminal" input and output goes through an Emacs buffer, d37340 1 a37340 1 the usual way--for example, ‘C-c C-c’ for an interrupt, ‘C-c C-z’ d37343 1 a37343 1 • GDB displays source code through Emacs. d37346 1 a37346 1 source file for that frame and puts an arrow (‘=>’) at the left d37351 1 a37351 1 Explicit GDB ‘list’ or search commands still produce output as d37354 1 a37354 1 We call this “text command mode”. Emacs 22.1, and later, also uses a d37359 1 a37359 1 If you specify an absolute file name when prompted for the ‘M-x gdb’ d37364 1 a37364 1 your environment's ‘PATH’ variable, but on some operating systems it d37374 1 a37374 1 By default, ‘M-x gdb’ calls the program called ‘gdb’. If you need to d37377 1 a37377 1 variable ‘gud-gdb-command-name’ to run the one you want. d37382 1 a37382 1 ‘C-h m’ d37385 2 a37386 2 ‘C-c C-s’ Execute to another source line, like the GDB ‘step’ command; also d37389 1 a37389 1 ‘C-c C-n’ d37391 1 a37391 1 calls, like the GDB ‘next’ command. Then update the display window d37394 2 a37395 2 ‘C-c C-i’ Execute one instruction, like the GDB ‘stepi’ command; update d37398 1 a37398 1 ‘C-c C-f’ d37400 1 a37400 1 ‘finish’ command. d37402 2 a37403 2 ‘C-c C-r’ Continue execution of your program, like the GDB ‘continue’ d37406 1 a37406 1 ‘C-c <’ d37408 1 a37408 1 Numeric Arguments: (Emacs)Arguments.), like the GDB ‘up’ command. d37410 1 a37410 1 ‘C-c >’ d37412 1 a37412 1 like the GDB ‘down’ command. d37414 1 a37414 1 In any source file, the Emacs command ‘C-x ’ (‘gud-break’) tells d37417 1 a37417 1 In text command mode, if you type ‘M-x speedbar’, Emacs displays a d37421 1 a37421 1 buffer. Alternatively, click ‘Mouse-2’ to make the selected frame d37426 1 a37426 1 get it back is to type the command ‘f’ in the GDB buffer, to request a d37477 1 a37477 1 activated by specifying using the ‘--interpreter’ command line option d37494 1 a37494 1 • ‘|’ separates two alternatives. d37496 1 a37496 1 • ‘[ SOMETHING ]’ indicates that SOMETHING is optional: it may or may d37499 1 a37499 1 • ‘( GROUP )*’ means that GROUP inside the parentheses may repeat d37502 1 a37502 1 • ‘( GROUP )+’ means that GROUP inside the parentheses may repeat one d37505 1 a37505 1 • ‘( GROUP )’ means that GROUP inside the parentheses occurs exactly d37508 1 a37508 1 • ‘"STRING"’ means a literal STRING. d37556 1 a37556 1 • Exec notifications. These are used to report changes in target d37564 1 a37564 1 • Console output, and status notifications. Console output d37571 1 a37571 1 • General notifications. Commands may have various side effects on d37616 1 a37616 1 MI command accepts the ‘--thread’ and ‘--frame’ options, the value to d37624 2 a37625 2 hit. For another example, if the user issues the CLI ‘thread’ or ‘frame’ commands via the frontend, it is desirable to change the d37628 1 a37628 1 ‘=thread-selected’ notification. d37631 1 a37631 1 frontends used the ‘-thread-select’ to execute commands in the right d37633 1 a37633 1 simplest way is for frontend to emit ‘-thread-select’ command before d37635 1 a37635 1 sent. The alternative approach is to suppress ‘-thread-select’ if the d37642 1 a37642 1 add ‘-thread-select’ for all subsequent commands. No frontend is known d37644 1 a37644 1 ‘--thread’ and ‘--frame’ options. d37652 1 a37652 1 the ‘--language’ option. This option takes one argument, which is the d37659 3 a37661 3 The valid language names are the same names accepted by the ‘set language’ command (*note Manually::), excluding ‘auto’, ‘local’ or ‘unknown’. d37670 1 a37670 1 target is running. This is called “asynchronous command execution” d37672 1 a37672 1 for asynchronous execution using the ‘-gdb-set mi-async 1’ command, d37676 1 a37676 1 enabled using the ‘-list-target-features’ command. d37678 1 a37678 1 ‘-gdb-set mi-async [on|off]’ d37681 2 a37682 2 When ‘off’, which is the default, MI execution commands (e.g., ‘-exec-continue’) are foreground commands, and GDB waits for the d37685 2 a37686 2 When ‘on’, MI execution commands are background execution commands (e.g., ‘-exec-continue’ becomes the equivalent of the ‘c&’ CLI d37690 1 a37690 1 ‘-gdb-show mi-async’ d37694 1 a37694 1 ‘target-async’ instead of ‘mi-async’, and it had the effect of both d37711 1 a37711 1 that even commands that operate on global state, such as ‘print’, ‘set’, d37714 1 a37714 1 perform the operation on that thread (using the ‘--thread’ option). d37717 2 a37718 2 target dependent. However, the two commands ‘-exec-interrupt’, to stop a thread, and ‘-thread-info’, to find the state of a thread, will always d37735 1 a37735 1 accept the ‘--thread’ option do not need to know what process that d37737 1 a37737 1 additional ‘--process’ option, nor an notion of the current process in d37743 1 a37743 1 “thread group”. Thread group is a collection of threads and other d37746 1 a37746 1 ‘-list-thread-groups’, returns the list of top-level thread groups, d37748 1 a37748 1 passing an identifier of a thread group to the ‘-list-thread-groups’ d37752 1 a37752 1 wishes to debug, a concept of “available thread group” is introduced. d37754 1 a37754 1 that can be attached to, using the ‘-target-attach’ command. The list d37756 1 a37756 1 ‘-list-thread-groups --available’. In general, the content of a thread d37761 1 a37761 1 special type ‘process’, and some additional operations are permitted on d37781 2 a37782 2 ‘COMMAND ↦’ ‘CLI-COMMAND | MI-COMMAND’ d37784 2 a37785 2 ‘CLI-COMMAND ↦’ ‘[ TOKEN ] CLI-COMMAND NL’, where CLI-COMMAND is any existing GDB d37788 3 a37790 3 ‘MI-COMMAND ↦’ ‘[ TOKEN ] "-" OPERATION ( " " OPTION )* [ " --" ] ( " " PARAMETER )* NL’ d37792 1 a37792 1 ‘TOKEN ↦’ d37795 2 a37796 2 ‘OPTION ↦’ ‘"-" PARAMETER [ " " PARAMETER ]’ d37798 2 a37799 2 ‘PARAMETER ↦’ ‘NON-BLANK-SEQUENCE | C-STRING’ d37801 1 a37801 1 ‘OPERATION ↦’ d37804 1 a37804 1 ‘NON-BLANK-SEQUENCE ↦’ d37808 2 a37809 2 ‘C-STRING ↦’ ‘""" SEVEN-BIT-ISO-C-STRING-CONTENT """’ d37811 2 a37812 2 ‘NL ↦’ ‘CR | CR-LF’ d37816 1 a37816 1 • The CLI commands are still handled by the MI interpreter; their d37819 1 a37819 1 • The ‘TOKEN’, when present, is passed back when the command d37822 2 a37823 2 • Some MI commands accept optional arguments as part of the parameter list. Each option is identified by a leading ‘-’ (dash) and may be d37826 1 a37826 1 using ‘--’ (this is useful when some parameters begin with a dash). d37830 1 a37830 1 • We want easy access to the existing CLI syntax (for debugging). d37832 1 a37832 1 • We want it to be easy to spot a MI operation. d37843 1 a37843 1 terminated by ‘(gdb)’. d37845 1 a37845 1 If an input command was prefixed with a ‘TOKEN’ then the d37849 2 a37850 2 ‘OUTPUT ↦’ ‘( OUT-OF-BAND-RECORD )* [ RESULT-RECORD ] "(gdb)" NL’ d37852 2 a37853 2 ‘RESULT-RECORD ↦’ ‘ [ TOKEN ] "^" RESULT-CLASS ( "," RESULT )* NL’ d37855 2 a37856 2 ‘OUT-OF-BAND-RECORD ↦’ ‘ASYNC-RECORD | STREAM-RECORD’ d37858 2 a37859 2 ‘ASYNC-RECORD ↦’ ‘EXEC-ASYNC-OUTPUT | STATUS-ASYNC-OUTPUT | NOTIFY-ASYNC-OUTPUT’ d37861 2 a37862 2 ‘EXEC-ASYNC-OUTPUT ↦’ ‘[ TOKEN ] "*" ASYNC-OUTPUT NL’ d37864 2 a37865 2 ‘STATUS-ASYNC-OUTPUT ↦’ ‘[ TOKEN ] "+" ASYNC-OUTPUT NL’ d37867 2 a37868 2 ‘NOTIFY-ASYNC-OUTPUT ↦’ ‘[ TOKEN ] "=" ASYNC-OUTPUT NL’ d37870 2 a37871 2 ‘ASYNC-OUTPUT ↦’ ‘ASYNC-CLASS ( "," RESULT )*’ d37873 2 a37874 2 ‘RESULT-CLASS ↦’ ‘"done" | "running" | "connected" | "error" | "exit"’ d37876 2 a37877 2 ‘ASYNC-CLASS ↦’ ‘"stopped" | OTHERS’ (where OTHERS will be added depending on the d37880 2 a37881 2 ‘RESULT ↦’ ‘ VARIABLE "=" VALUE’ d37883 2 a37884 2 ‘VARIABLE ↦’ ‘ STRING ’ d37886 2 a37887 2 ‘VALUE ↦’ ‘ CONST | TUPLE | LIST ’ d37889 2 a37890 2 ‘CONST ↦’ ‘C-STRING’ d37892 2 a37893 2 ‘TUPLE ↦’ ‘ "{}" | "{" RESULT ( "," RESULT )* "}" ’ d37895 3 a37897 3 ‘LIST ↦’ ‘ "[]" | "[" VALUE ( "," VALUE )* "]" | "[" RESULT ( "," RESULT )* "]" ’ d37899 2 a37900 2 ‘STREAM-RECORD ↦’ ‘CONSOLE-STREAM-OUTPUT | TARGET-STREAM-OUTPUT | LOG-STREAM-OUTPUT’ d37902 2 a37903 2 ‘CONSOLE-STREAM-OUTPUT ↦’ ‘"~" C-STRING NL’ d37905 2 a37906 2 ‘TARGET-STREAM-OUTPUT ↦’ ‘"@@" C-STRING NL’ d37908 2 a37909 2 ‘LOG-STREAM-OUTPUT ↦’ ‘"&" C-STRING NL’ d37911 2 a37912 2 ‘NL ↦’ ‘CR | CR-LF’ d37914 1 a37914 1 ‘TOKEN ↦’ d37919 1 a37919 1 • All output sequences end in a single line containing a period. d37921 1 a37921 1 • The ‘TOKEN’ is from the corresponding request. Note that for all d37928 1 a37928 1 • STATUS-ASYNC-OUTPUT contains on-going status information about the d37930 1 a37930 1 output is prefixed by ‘+’. d37932 1 a37932 1 • EXEC-ASYNC-OUTPUT contains asynchronous state change on the target d37934 1 a37934 1 ‘*’. d37936 1 a37936 1 • NOTIFY-ASYNC-OUTPUT contains supplementary information that the d37938 1 a37938 1 notify output is prefixed by ‘=’. d37940 1 a37940 1 • CONSOLE-STREAM-OUTPUT is output that should be displayed as is in d37942 1 a37942 1 console output is prefixed by ‘~’. d37944 2 a37945 2 • TARGET-STREAM-OUTPUT is the output produced by the target program. All the target output is prefixed by ‘@@’. d37947 1 a37947 1 • LOG-STREAM-OUTPUT is output text coming from GDB's internals, for d37949 1 a37949 1 All the log output is prefixed by ‘&’. d37951 1 a37951 1 • New GDB/MI commands should only output LISTS containing VALUES. d37965 2 a37966 2 command lists are not executed and some CLI commands, such as ‘if’, ‘when’ and ‘define’, prompt for further input with ‘>’, which is not d37970 1 a37970 1 recommended that front ends use the ‘-interpreter-exec’ command (*note d37980 1 a37980 1 program being debugged to the user is called a “front end”. d37992 1 a37992 1 • New MI commands may be added. d37994 1 a37994 1 • New fields may be added to the output of any MI command. d37996 2 a37997 2 • The range of values for fields with specified values, e.g., ‘in_scope’ (*note -var-update::) may be extended. d38005 1 a38005 1 Since ‘--interpreter=mi’ always points to the latest MI version, it d38007 1 a38007 1 launching GDB (e.g. ‘--interpreter=mi2’) to make sure they get an d38020 2 a38021 2 • The ‘-environment-pwd’, ‘-environment-directory’ and ‘-environment-path’ commands now returns values d38025 1 a38025 1 • ‘-var-list-children’'s ‘children’ result field is d38028 1 a38028 1 • ‘-var-update’'s ‘changelist’ result field is now a d38032 1 a38032 1 • The output of information about multi-location d38034 4 a38037 4 ‘-break-insert’ and ‘-break-info’ commands, as well as in the ‘=breakpoint-created’ and ‘=breakpoint-modified’ events. The multiple locations are now placed in a ‘locations’ field, d38041 1 a38041 1 • The syntax of the "script" field in breakpoint d38043 3 a38045 3 ‘-break-insert’ and ‘-break-info’ commands, as well as the ‘=breakpoint-created’ and ‘=breakpoint-modified’ events. The previous output d38054 1 a38054 1 ‘-fix-multi-location-breakpoint-output’ d38059 1 a38059 1 ‘-fix-breakpoint-script-output’ d38093 2 a38094 2 ‘"^done" [ "," RESULTS ]’ The synchronous operation was successful, ‘RESULTS’ are the return d38097 3 a38099 3 ‘"^running"’ This result record is equivalent to ‘^done’. Historically, it was output instead of ‘^done’ if the command has resumed the target. d38101 2 a38102 2 frontends should treat ‘^done’ and ‘^running’ identically and rely on the ‘*running’ output record to determine which threads are d38105 1 a38105 1 ‘"^connected"’ d38108 2 a38109 2 ‘"^error" "," "msg=" C-STRING [ "," "code=" C-STRING ]’ The operation failed. The ‘msg=C-STRING’ variable contains the d38112 1 a38112 1 If present, the ‘code=C-STRING’ variable provides an error code on d38116 1 a38116 1 ‘"undefined-command"’ d38119 1 a38119 1 ‘"^exit"’ d38130 1 a38130 1 funneled through the GDB/MI interface using “stream records”. d38132 1 a38132 1 Each stream record begins with a unique “prefix character” which d38135 1 a38135 1 ‘STRING-OUTPUT’. This is either raw text (with an implicit new line) or d38138 1 a38138 1 ‘"~" STRING-OUTPUT’ d38143 1 a38143 1 ‘"@@" STRING-OUTPUT’ d38149 1 a38149 1 ‘"&" STRING-OUTPUT’ d38159 1 a38159 1 “Async” records are used to notify the GDB/MI client of additional d38166 1 a38166 1 ‘*running,thread-id="THREAD"’ d38168 1 a38168 1 thread ID of the thread that is now running, and it can be ‘all’ if d38178 1 a38178 1 ‘*stopped,reason="REASON",thread-id="ID",stopped-threads="STOPPED",core="CORE"’ d38182 1 a38182 1 ‘breakpoint-hit’ d38184 1 a38184 1 ‘watchpoint-trigger’ d38186 1 a38186 1 ‘read-watchpoint-trigger’ d38188 1 a38188 1 ‘access-watchpoint-trigger’ d38190 1 a38190 1 ‘function-finished’ d38192 1 a38192 1 ‘location-reached’ d38194 1 a38194 1 ‘watchpoint-scope’ d38196 1 a38196 1 ‘end-stepping-range’ d38200 1 a38200 1 ‘exited-signalled’ d38202 1 a38202 1 ‘exited’ d38204 1 a38204 1 ‘exited-normally’ d38206 1 a38206 1 ‘signal-received’ d38208 1 a38208 1 ‘solib-event’ d38210 2 a38211 2 unloaded. This can happen when ‘stop-on-solib-events’ (*note Files::) is set or when a ‘catch load’ or ‘catch unload’ d38213 2 a38214 2 ‘fork’ The inferior has forked. This is reported when ‘catch fork’ d38216 4 a38219 4 ‘vfork’ The inferior has vforked. This is reported in when ‘catch vfork’ (*note Set Catchpoints::) has been used. ‘syscall-entry’ d38221 2 a38222 2 ‘catch syscall’ (*note Set Catchpoints::) has been used. ‘syscall-return’ d38224 5 a38228 5 when ‘catch syscall’ (*note Set Catchpoints::) has been used. ‘exec’ The inferior called ‘exec’. This is reported when ‘catch exec’ (*note Set Catchpoints::) has been used. ‘no-history’ d38237 1 a38237 1 STOPPED field will have the value of ‘"all"’. Otherwise, the value d38245 2 a38246 2 ‘=thread-group-added,id="ID"’ ‘=thread-group-removed,id="ID"’ d38253 1 a38253 1 ‘=thread-group-started,id="ID",pid="PID"’ d38260 1 a38260 1 ‘=thread-group-exited,id="ID"[,exit-code="CODE"]’ d38267 2 a38268 2 ‘=thread-created,id="ID",group-id="GID"’ ‘=thread-exited,id="ID",group-id="GID"’ d38273 1 a38273 1 ‘=thread-selected,id="ID"[,frame="FRAME"]’ d38275 2 a38276 2 notification is not emitted as result of the ‘-thread-select’ or ‘-stack-select-frame’ commands, but is emitted whenever an MI d38279 1 a38279 1 indirectly (via user-defined command), the CLI ‘thread’ or ‘frame’ d38292 1 a38292 1 ‘=library-loaded,...’ d38307 1 a38307 1 ‘=library-unloaded,...’ d38310 1 a38310 1 same meaning as for the ‘=library-loaded’ notification. The d38316 2 a38317 2 ‘=traceframe-changed,num=TFNUM,tracepoint=TPNUM’ ‘=traceframe-changed,end’ d38322 1 a38322 1 ‘=tsv-created,name=NAME,initial=INITIAL’ d38326 2 a38327 2 ‘=tsv-deleted,name=NAME’ ‘=tsv-deleted’ d38331 1 a38331 1 ‘=tsv-modified,name=NAME,initial=INITIAL[,current=CURRENT]’ d38337 3 a38339 3 ‘=breakpoint-created,bkpt={...}’ ‘=breakpoint-modified,bkpt={...}’ ‘=breakpoint-deleted,id=NUMBER’ d38351 2 a38352 2 ‘=record-started,thread-group="ID",method="METHOD"[,format="FORMAT"]’ ‘=record-stopped,thread-group="ID"’ d38362 5 a38366 5 ‘=cmd-param-changed,param=PARAM,value=VALUE’ Reports that a parameter of the command ‘set PARAM’ is changed to VALUE. In the multi-word ‘set’ command, the PARAM is the whole parameter list to ‘set’ command. For example, In command ‘set check type on’, PARAM is ‘check type’ and VALUE is ‘on’. d38368 1 a38368 1 ‘=memory-changed,thread-group=ID,addr=ADDR,len=LEN[,type="code"]’ d38371 1 a38371 1 corresponding to the affected inferior. The optional ‘type="code"’ d38383 1 a38383 1 ‘number’ d38386 1 a38386 1 ‘type’ d38388 1 a38388 1 ‘breakpoint’, but many values are possible. d38390 2 a38391 2 ‘catch-type’ If the type of the breakpoint is ‘catchpoint’, then this indicates d38394 3 a38396 3 ‘disp’ This is the breakpoint disposition--either ‘del’, meaning that the breakpoint will be deleted at the next stop, or ‘keep’, meaning d38399 1 a38399 1 ‘enabled’ d38401 2 a38402 2 value is ‘y’, or disabled, in which case the value is ‘n’. Note that this is not the same as the field ‘enable’. d38404 1 a38404 1 ‘addr’ d38406 2 a38407 2 giving the address; or the string ‘’, for a pending breakpoint; or the string ‘’, for a breakpoint with d38412 1 a38412 1 ‘addr_flags’ d38417 1 a38417 1 ‘func’ d38421 1 a38421 1 ‘filename’ d38425 1 a38425 1 ‘fullname’ d38429 1 a38429 1 ‘line’ d38433 1 a38433 1 ‘at’ d38438 1 a38438 1 ‘pending’ d38442 3 a38444 3 ‘evaluated-by’ Where this breakpoint's condition is evaluated, either ‘host’ or ‘target’. d38446 1 a38446 1 ‘thread’ d38450 1 a38450 1 ‘inferior’ d38454 1 a38454 1 ‘task’ d38458 1 a38458 1 ‘cond’ d38461 1 a38461 1 ‘ignore’ d38464 1 a38464 1 ‘enable’ d38467 1 a38467 1 ‘traceframe-usage’ d38470 1 a38470 1 ‘static-tracepoint-marker-string-id’ d38473 1 a38473 1 ‘mask’ d38476 1 a38476 1 ‘pass’ d38479 1 a38479 1 ‘original-location’ d38483 1 a38483 1 ‘times’ d38486 3 a38488 3 ‘installed’ This field is only given for tracepoints. This is either ‘y’, meaning that the tracepoint is installed, or ‘n’, meaning that it d38491 1 a38491 1 ‘what’ d38494 1 a38494 1 ‘locations’ d38505 2 a38506 2 ‘number’ The location number as a dotted pair, like ‘1.2’. The first digit d38510 1 a38510 1 ‘enabled’ d38512 1 a38512 1 ‘y’ d38514 1 a38514 1 ‘n’ d38516 1 a38516 1 ‘N’ d38520 1 a38520 1 ‘addr’ d38523 1 a38523 1 ‘addr_flags’ d38528 1 a38528 1 ‘func’ d38532 1 a38532 1 ‘file’ d38536 1 a38536 1 ‘fullname’ d38540 1 a38540 1 ‘line’ d38544 1 a38544 1 ‘thread-groups’ d38547 1 a38547 1 For example, here is what the output of ‘-break-insert’ (*note GDB/MI d38566 1 a38566 1 ‘level’ d38570 1 a38570 1 ‘func’ d38574 1 a38574 1 ‘addr’ d38577 1 a38577 1 ‘addr_flags’ d38582 1 a38582 1 ‘file’ d38586 1 a38586 1 ‘line’ d38590 1 a38590 1 ‘from’ d38605 1 a38605 1 ‘id’ d38608 1 a38608 1 ‘target-id’ d38611 1 a38611 1 ‘details’ d38616 1 a38616 1 ‘name’ d38618 1 a38618 1 ‘thread name’ command, then this name is given. Otherwise, if GDB d38623 2 a38624 2 ‘state’ The execution state of the thread, either ‘stopped’ or ‘running’, d38627 1 a38627 1 ‘frame’ d38632 1 a38632 1 ‘core’ d38642 1 a38642 1 Whenever a ‘*stopped’ record is emitted because the program stopped d38645 2 a38646 2 ‘exception-name’ field. Also, for exceptions that were raised with an exception message, GDB provides that message via the ‘exception-message’ d38656 2 a38657 2 the GDB/MI interface. In these examples, ‘->’ means that the following line is passed to GDB/MI as input, while ‘<-’ means the output received d38700 1 a38700 1 Quitting GDB just prints the result class ‘^exit’. d38706 1 a38706 1 Please note that ‘^exit’ is printed immediately, but it might take d38774 1 a38774 1 The ‘-break-after’ Command d38784 1 a38784 1 ‘-break-list’ command, see the description of the ‘-break-list’ command d38790 1 a38790 1 The corresponding GDB command is ‘ignore’. d38819 1 a38819 1 The ‘-break-commands’ Command d38837 1 a38837 1 The corresponding GDB command is ‘commands’. d38853 1 a38853 1 The ‘-break-condition’ Command d38862 2 a38863 2 is true. The condition becomes part of the ‘-break-list’ output (see the description of the ‘-break-list’ command below). If the ‘--force’ d38871 1 a38871 1 The corresponding GDB command is ‘condition’. d38893 1 a38893 1 The ‘-break-delete’ Command d38907 1 a38907 1 The corresponding GDB command is ‘delete’. d38927 1 a38927 1 The ‘-break-disable’ Command d38935 2 a38936 2 Disable the named BREAKPOINT(s). The field ‘enabled’ in the break list is now set to ‘n’ for the named BREAKPOINT(s). d38941 1 a38941 1 The corresponding GDB command is ‘disable’. d38963 1 a38963 1 The ‘-break-enable’ Command d38976 1 a38976 1 The corresponding GDB command is ‘enable’. d38998 1 a38998 1 The ‘-break-info’ Command d39015 1 a39015 1 The corresponding GDB command is ‘info break BREAKPOINT’. d39022 1 a39022 1 The ‘-break-insert’ Command d39042 1 a39042 1 ‘--source FILENAME’ d39044 1 a39044 1 the use of either ‘--function’ or ‘--line’. d39046 1 a39046 1 ‘--function FUNCTION’ d39049 1 a39049 1 ‘--label LABEL’ d39052 1 a39052 1 ‘--line LINEOFFSET’ d39061 1 a39061 1 ‘-t’ d39063 1 a39063 1 ‘-h’ d39065 1 a39065 1 ‘-f’ d39070 1 a39070 1 ‘-d’ d39072 1 a39072 1 ‘-a’ d39074 2 a39075 2 used together with ‘-h’, a fast tracepoint is created. ‘-c CONDITION’ d39077 1 a39077 1 ‘--force-condition’ d39080 1 a39080 1 ‘-i IGNORE-COUNT’ d39082 1 a39082 1 ‘-p THREAD-ID’ d39087 1 a39087 1 ‘-g THREAD-GROUP-ID’ d39090 1 a39090 1 ‘--qualified’ d39105 2 a39106 2 The corresponding GDB commands are ‘break’, ‘tbreak’, ‘hbreak’, and ‘thbreak’. d39140 1 a39140 1 The ‘-dprintf-insert’ Command d39155 2 a39156 2 If supplied, LOCSPEC and ‘--qualified’ may be specified the same way as for the ‘-break-insert’ command. *Note -break-insert::. d39160 1 a39160 1 ‘-t’ d39162 1 a39162 1 ‘-f’ d39167 1 a39167 1 ‘-d’ d39169 1 a39169 1 ‘-c CONDITION’ d39171 1 a39171 1 ‘--force-condition’ d39174 1 a39174 1 ‘-i IGNORE-COUNT’ d39177 1 a39177 1 ‘-p THREAD-ID’ d39190 1 a39190 1 The corresponding GDB command is ‘dprintf’. d39211 1 a39211 1 The ‘-break-list’ Command d39222 1 a39222 1 ‘Number’ d39224 8 a39231 8 ‘Type’ type of the breakpoint: ‘breakpoint’ or ‘watchpoint’ ‘Disposition’ should the breakpoint be deleted or disabled when it is hit: ‘keep’ or ‘nokeep’ ‘Enabled’ is the breakpoint enabled or no: ‘y’ or ‘n’ ‘Address’ d39233 1 a39233 1 ‘What’ d39236 1 a39236 1 ‘Thread-groups’ d39238 1 a39238 1 ‘Times’ d39242 1 a39242 1 catchpoints, the ‘BreakpointTable’ ‘body’ field is an empty list. d39247 1 a39247 1 The corresponding GDB command is ‘info break’. d39283 1 a39283 1 The ‘-break-passcount’ Command d39293 1 a39293 1 error is emitted. This corresponds to CLI command ‘passcount’. d39295 1 a39295 1 The ‘-break-watch’ Command d39303 1 a39303 1 Create a watchpoint. With the ‘-a’ option it will create an “access” d39305 2 a39306 2 a write to the memory location. With the ‘-r’ option, the watchpoint created is a “read” watchpoint, i.e., it will trigger only when the d39312 1 a39312 1 Note that ‘-break-list’ will report a single list of watchpoints and d39318 1 a39318 1 The corresponding GDB commands are ‘watch’, ‘awatch’, and ‘rwatch’. d39323 1 a39323 1 Setting a watchpoint on a variable in the ‘main’ function: d39461 1 a39461 1 The ‘-catch-load’ Command d39469 1 a39469 1 Add a catchpoint for library load events. If the ‘-t’ option is d39471 2 a39472 2 Breaks.). If the ‘-d’ option is used, the catchpoint is created in a disabled state. The ‘regexp’ argument is a regular expression used to d39478 1 a39478 1 The corresponding GDB command is ‘catch load’. d39488 1 a39488 1 The ‘-catch-unload’ Command d39496 1 a39496 1 Add a catchpoint for library unload events. If the ‘-t’ option is d39498 2 a39499 2 Breaks.). If the ‘-d’ option is used, the catchpoint is created in a disabled state. The ‘regexp’ argument is a regular expression used to d39505 1 a39505 1 The corresponding GDB command is ‘catch unload’. d39524 1 a39524 1 The ‘-catch-assert’ Command d39536 1 a39536 1 ‘-c CONDITION’ d39538 1 a39538 1 ‘-d’ d39540 1 a39540 1 ‘-t’ d39546 1 a39546 1 The corresponding GDB command is ‘catch assert’. d39558 1 a39558 1 The ‘-catch-exception’ Command d39574 1 a39574 1 ‘-c CONDITION’ d39576 1 a39576 1 ‘-d’ d39578 1 a39578 1 ‘-e EXCEPTION-NAME’ d39580 2 a39581 2 used combined with ‘-u’. ‘-t’ d39583 1 a39583 1 ‘-u’ d39585 1 a39585 1 cannot be used combined with ‘-e’. d39590 2 a39591 2 The corresponding GDB commands are ‘catch exception’ and ‘catch exception unhandled’. d39603 1 a39603 1 The ‘-catch-handlers’ Command d39619 1 a39619 1 ‘-c CONDITION’ d39621 1 a39621 1 ‘-d’ d39623 1 a39623 1 ‘-e EXCEPTION-NAME’ d39625 1 a39625 1 ‘-t’ d39631 1 a39631 1 The corresponding GDB command is ‘catch handlers’. d39653 1 a39653 1 The ‘-catch-throw’ Command d39665 1 a39665 1 If ‘-t’ is given, then the catchpoint is enabled only for one stop, d39672 1 a39672 1 The corresponding GDB commands are ‘catch throw’ and ‘tcatch throw’ d39696 1 a39696 1 The ‘-catch-rethrow’ Command d39708 1 a39708 1 If ‘-t’ is given, then the catchpoint is enabled only for one stop, d39714 1 a39714 1 The corresponding GDB commands are ‘catch rethrow’ and ‘tcatch rethrow’ d39738 1 a39738 1 The ‘-catch-catch’ Command d39750 1 a39750 1 If ‘-t’ is given, then the catchpoint is enabled only for one stop, d39756 1 a39756 1 The corresponding GDB commands are ‘catch catch’ and ‘tcatch catch’ d39786 1 a39786 1 The ‘-exec-arguments’ Command d39795 1 a39795 1 ‘-exec-run’. d39800 1 a39800 1 The corresponding GDB command is ‘set args’. d39810 1 a39810 1 The ‘-environment-cd’ Command d39823 1 a39823 1 The corresponding GDB command is ‘cd’. d39833 1 a39833 1 The ‘-environment-directory’ Command d39842 1 a39842 1 If the ‘-r’ option is used, the search path is reset to the default d39844 1 a39844 1 ‘-r’ option, the search path is first reset and then addition occurs as d39858 1 a39858 1 The corresponding GDB command is ‘dir’. d39877 1 a39877 1 The ‘-environment-path’ Command d39886 1 a39886 1 If the ‘-r’ option is used, the search path is reset to the original d39888 1 a39888 1 supplied in addition to the ‘-r’ option, the search path is first reset d39902 1 a39902 1 The corresponding GDB command is ‘path’. d39918 1 a39918 1 The ‘-environment-pwd’ Command d39931 1 a39931 1 The corresponding GDB command is ‘pwd’. d39947 1 a39947 1 The ‘-thread-info’ Command d39963 1 a39963 1 The ‘info thread’ command prints the same information about all threads. d39970 1 a39970 1 ‘threads’ d39974 1 a39974 1 ‘current-thread-id’ d39996 1 a39996 1 The ‘-thread-list-ids’ Command d40007 1 a40007 1 This command is retained for historical reasons, the ‘-thread-info’ d40013 1 a40013 1 Part of ‘info threads’ supplies the same information. d40024 1 a40024 1 The ‘-thread-select’ Command d40037 1 a40037 1 ‘--thread’ option to each command. d40042 1 a40042 1 The corresponding GDB command is ‘thread’. d40072 1 a40072 1 The ‘-ada-task-info’ Command d40086 1 a40086 1 The ‘info tasks’ command prints the same information about all Ada tasks d40095 1 a40095 1 ‘current’ d40097 1 a40097 1 ‘*’. d40099 1 a40099 1 ‘id’ d40102 1 a40102 1 ‘task-id’ d40105 1 a40105 1 ‘thread-id’ d40113 1 a40113 1 ‘parent-id’ d40117 1 a40117 1 ‘priority’ d40120 1 a40120 1 ‘state’ d40124 1 a40124 1 ‘name’ d40151 1 a40151 1 record ‘*stopped’. Currently GDB only really executes asynchronously d40154 1 a40154 1 The ‘-exec-continue’ Command d40163 1 a40163 1 execute until it reaches a debugger stop event. If the ‘--reverse’ d40166 4 a40169 4 • breakpoints, watchpoints, tracepoints, or catchpoints • signals or exceptions • the end of the process (or its beginning under ‘--reverse’) • the end or beginning of a replay log if one is being used. d40171 4 a40174 4 or all threads, depending on the value of the ‘scheduler-locking’ variable. If ‘--all’ is specified, all threads (in all inferiors) will be resumed. The ‘--all’ option is ignored in all-stop mode. If the ‘--thread-group’ options is specified, then all threads in that thread d40180 1 a40180 1 The corresponding GDB corresponding is ‘continue’. d40194 3 a40196 3 For a ‘breakpoint-hit’ stopped reason, when the breakpoint encountered has multiple locations, the field ‘bkptno’ is followed by the field ‘locno’. d40207 1 a40207 1 The ‘-exec-finish’ Command d40217 1 a40217 1 the ‘--reverse’ option is specified, resumes the reverse execution of d40223 1 a40223 1 The corresponding GDB command is ‘finish’. d40228 1 a40228 1 Function returning ‘void’. d40238 1 a40238 1 Function returning other than ‘void’. The name of the internal GDB d40251 1 a40251 1 The ‘-exec-interrupt’ Command d40262 1 a40262 1 only appears in the ‘^done’ output. If the user is trying to interrupt d40267 2 a40268 2 ‘^done’ response will be printed, and the target stop will be reported after that using the ‘*stopped’ notification. d40271 2 a40272 2 All threads (in all inferiors) will be interrupted if the ‘--all’ option is specified. If the ‘--thread-group’ option is specified, all threads d40278 1 a40278 1 The corresponding GDB command is ‘interrupt’. d40301 1 a40301 1 The ‘-exec-jump’ Command d40316 1 a40316 1 The corresponding GDB command is ‘jump’. d40325 1 a40325 1 The ‘-exec-next’ Command d40336 1 a40336 1 If the ‘--reverse’ option is specified, resumes reverse execution of d40345 1 a40345 1 The corresponding GDB command is ‘next’. d40356 1 a40356 1 The ‘-exec-next-instruction’ Command d40369 1 a40369 1 If the ‘--reverse’ option is specified, resumes reverse execution of d40378 1 a40378 1 The corresponding GDB command is ‘nexti’. d40392 1 a40392 1 The ‘-exec-return’ Command d40406 1 a40406 1 The corresponding GDB command is ‘return’. d40437 1 a40437 1 The ‘-exec-run’ Command d40450 2 a40451 2 When neither the ‘--all’ nor the ‘--thread-group’ option is specified, the current inferior is started. If the ‘--thread-group’ d40453 1 a40453 1 ‘process’, and that thread group will be started. If the ‘--all’ option d40456 1 a40456 1 Using the ‘--start’ option instructs the debugger to stop the d40458 1 a40458 1 same behavior as the ‘start’ command (*note Starting::). d40463 1 a40463 1 The corresponding GDB command is ‘run’. d40501 1 a40501 1 as ‘SIGINT’. In this case, GDB/MI displays this: d40507 1 a40507 1 The ‘-exec-step’ Command d40518 1 a40518 1 called function. If the ‘--reverse’ option is specified, resumes d40525 1 a40525 1 The corresponding GDB command is ‘step’. d40549 1 a40549 1 The ‘-exec-step-instruction’ Command d40558 1 a40558 1 ‘--reverse’ option is specified, resumes reverse execution of the d40567 1 a40567 1 The corresponding GDB command is ‘stepi’. d40590 1 a40590 1 The ‘-exec-until’ Command d40601 1 a40601 1 stopping in this case will be ‘location-reached’. d40606 1 a40606 1 The corresponding GDB command is ‘until’. d40627 1 a40627 1 The ‘-enable-frame-filters’ Command d40642 1 a40642 1 The ‘-stack-info-frame’ Command d40655 1 a40655 1 The corresponding GDB command is ‘info frame’ or ‘frame’ (without d40669 1 a40669 1 The ‘-stack-info-depth’ Command d40707 1 a40707 1 The ‘-stack-list-arguments’ Command d40724 3 a40726 3 If PRINT-VALUES is 0 or ‘--no-values’, print only the names of the variables; if it is 1 or ‘--all-values’, print also their values; and if it is 2 or ‘--simple-values’, print the name, type and value for simple d40728 1 a40728 1 the option ‘--no-frame-filters’ is supplied, then Python frame filters d40731 1 a40731 1 If the ‘--skip-unavailable’ option is specified, arguments that are d40736 1 a40736 1 deprecated in favor of the ‘-stack-list-variables’ command. d40741 1 a40741 1 GDB does not have an equivalent command. ‘gdbtk’ has a ‘gdb_get_args’ d40743 1 a40743 1 ‘-stack-list-arguments’. d40806 1 a40806 1 The ‘-stack-list-frames’ Command d40817 1 a40817 1 ‘LEVEL’ d40820 3 a40822 3 ‘ADDR’ The ‘$pc’ value for that frame. ‘FUNC’ d40824 1 a40824 1 ‘FILE’ d40826 1 a40826 1 ‘FULLNAME’ d40828 3 a40830 3 ‘LINE’ Line number corresponding to the ‘$pc’. ‘FROM’ d40833 1 a40833 1 ‘ARCH’ d40843 1 a40843 1 option ‘--no-frame-filters’ is supplied, then Python frame filters will d40849 1 a40849 1 The corresponding GDB commands are ‘backtrace’ and ‘where’. d40923 1 a40923 1 The ‘-stack-list-locals’ Command d40932 3 a40934 3 PRINT-VALUES is 0 or ‘--no-values’, print only the names of the variables; if it is 1 or ‘--all-values’, print also their values; and if it is 2 or ‘--simple-values’, print the name, type and value for simple d40939 1 a40939 1 ‘--no-frame-filters’ is supplied, then Python frame filters will not be d40942 1 a40942 1 If the ‘--skip-unavailable’ option is specified, local variables that d40946 1 a40946 1 This command is deprecated in favor of the ‘-stack-list-variables’ d40952 1 a40952 1 ‘info locals’ in GDB, ‘gdb_get_locals’ in ‘gdbtk’. d40969 1 a40969 1 The ‘-stack-list-variables’ Command d40978 3 a40980 3 selected frame. If PRINT-VALUES is 0 or ‘--no-values’, print only the names of the variables; if it is 1 or ‘--all-values’, print also their values; and if it is 2 or ‘--simple-values’, print the name, type and d40982 1 a40982 1 structures and unions. If the option ‘--no-frame-filters’ is supplied, d40985 1 a40985 1 If the ‘--skip-unavailable’ option is specified, local variables and d40997 1 a40997 1 The ‘-stack-select-frame’ Command d41008 1 a41008 1 This command in deprecated in favor of passing the ‘--frame’ option d41014 2 a41015 2 The corresponding GDB commands are ‘frame’, ‘up’, ‘down’, ‘select-frame’, ‘up-silent’, and ‘down-silent’. d41078 1 a41078 1 Variable objects can be either “fixed” or “floating”. For the fixed d41094 1 a41094 1 If a fixed variable object for the ‘state’ variable is created in d41096 1 a41096 1 report the value of ‘state’ in the top-level ‘do_work’ invocation. On d41098 1 a41098 1 ‘state’ in the current frame. d41112 3 a41114 3 ‘-enable-pretty-printing’ enable Python-based pretty-printing ‘-var-create’ create a variable object ‘-var-delete’ delete the variable object and/or its d41116 6 a41121 6 ‘-var-set-format’ set the display format of this variable ‘-var-show-format’ show the display format of this variable ‘-var-info-num-children’ tells how many children this object has ‘-var-list-children’ return a list of the object's children ‘-var-info-type’ show the type of this variable object ‘-var-info-expression’ print parent-relative expression that d41123 1 a41123 1 ‘-var-info-path-expression’ print full expression that this variable d41125 1 a41125 1 ‘-var-show-attributes’ is this variable editable? does it exist d41127 5 a41131 5 ‘-var-evaluate-expression’ get the value of this variable ‘-var-assign’ set the value of this variable ‘-var-update’ update the variable and its children ‘-var-set-frozen’ set frozenness attribute ‘-var-set-update-range’ set range of children to display on d41140 1 a41140 1 The ‘-enable-pretty-printing’ Command d41155 1 a41155 1 The ‘-var-create’ Command d41169 1 a41169 1 referenced. It must be unique. If ‘-’ is specified, the varobj system d41175 2 a41176 2 specified by FRAME-ADDR. A ‘*’ indicates that the current frame should be used. A ‘@@’ indicates that a floating variable object must be d41180 1 a41180 1 not begin with a ‘*’), or one of the following: d41182 1 a41182 1 • ‘*ADDR’, where ADDR is the address of a memory cell d41184 1 a41184 1 • ‘*ADDR-ADDR’ -- a memory address range (TBD) d41186 1 a41186 1 • ‘$REGNAME’ -- a CPU register name d41189 1 a41189 1 In this case the varobj is known as a “dynamic varobj”. Dynamic varobjs d41191 1 a41191 1 ‘-enable-pretty-printing’ command is not sent, then GDB will never d41201 1 a41201 1 ‘name’ d41204 1 a41204 1 ‘numchild’ d41207 1 a41207 1 examine the ‘has_more’ attribute. d41209 1 a41209 1 ‘value’ d41211 1 a41211 1 aggregate (e.g., a ‘struct’), this value will not be interesting. d41213 1 a41213 1 pretty-printer object's ‘to_string’ method. d41215 1 a41215 1 ‘type’ d41217 2 a41218 2 would be printed by the GDB CLI. If ‘print object’ (*note set print object: Print Settings.) is set to ‘on’, the _actual_ (derived) d41221 1 a41221 1 ‘thread-id’ d41225 1 a41225 1 ‘has_more’ d41229 2 a41230 2 ‘dynamic’ This attribute will be present and have the value ‘1’ if the varobj d41234 1 a41234 1 ‘displayhint’ d41237 1 a41237 1 ‘display_hint’ method. *Note Pretty Printing API::. d41244 1 a41244 1 The ‘-var-delete’ Command d41253 1 a41253 1 With the ‘-c’ option, just deletes the children. d41257 1 a41257 1 The ‘-var-set-format’ Command d41270 1 a41270 1 FORMAT-SPEC ↦ d41274 1 a41274 1 on the variable type (like decimal for an ‘int’, hex for pointers, d41285 1 a41285 1 The ‘-var-show-format’ Command d41295 1 a41295 1 FORMAT ↦ d41298 1 a41298 1 The ‘-var-info-num-children’ Command d41314 1 a41314 1 The ‘-var-list-children’ Command d41324 1 a41324 1 single argument or if PRINT-VALUES has a value of 0 or ‘--no-values’, d41326 2 a41327 2 ‘--all-values’, also print their values; and if it is 2 or ‘--simple-values’ print the name and value for simple data types and d41336 2 a41337 2 to ‘-var-list-children’, but not future calls to ‘-var-update’. For this, you must instead use ‘-var-set-update-range’. The intent of this d41340 2 a41341 2 more children with ‘-var-list-children’, and then the front end could call ‘-var-set-update-range’ with a different range to ensure that d41360 1 a41360 1 ‘public’, ‘private’, or ‘protected’. In this case the type and d41372 2 a41373 2 The type of the child. If ‘print object’ (*note set print object: Print Settings.) is set to ‘on’, the _actual_ (derived) type of the d41390 1 a41390 1 ‘display_hint’ method. *Note Pretty Printing API::. d41393 1 a41393 1 This attribute will be present and have the value ‘1’ if the varobj d41399 1 a41399 1 ‘displayhint’ d41402 1 a41402 1 ‘display_hint’ method. *Note Pretty Printing API::. d41404 1 a41404 1 ‘has_more’ d41420 1 a41420 1 The ‘-var-info-type’ Command d41433 1 a41433 1 The ‘-var-info-expression’ Command d41445 2 a41446 2 For example, if ‘a’ is an array, and variable object ‘A’ was created for ‘a’, then we'll get this output: d41451 1 a41451 1 Here, the value of ‘lang’ is the language name, which can be found in d41454 2 a41455 2 Note that the output of the ‘-var-list-children’ command also includes those expressions, so the ‘-var-info-expression’ command is of d41458 1 a41458 1 The ‘-var-info-path-expression’ Command d41468 2 a41469 2 with the ‘-var-info-expression’ command, which result can be used only for UI presentation. Typical use of the ‘-var-info-path-expression’ d41475 4 a41478 4 For example, suppose ‘C’ is a C++ class, derived from class ‘Base’, and that the ‘Base’ class has a member called ‘m_size’. Assume a variable ‘c’ is has the type of ‘C’ and a variable object ‘C’ was created for variable ‘c’. Then, we'll get this output: d41482 1 a41482 1 The ‘-var-show-attributes’ Command d41494 1 a41494 1 where ATTR is ‘{ { editable | noneditable } | TBD }’. d41496 1 a41496 1 The ‘-var-evaluate-expression’ Command d41506 3 a41508 3 string can be specified with the ‘-f’ option. The possible values of this option are the same as for ‘-var-set-format’ (*note -var-set-format::). If the ‘-f’ option is not specified, the current d41510 1 a41510 1 using the ‘-var-set-format’ command. d41514 1 a41514 1 Note that one must invoke ‘-var-list-children’ for a variable before d41517 1 a41517 1 The ‘-var-assign’ Command d41526 1 a41526 1 NAME. The object must be ‘editable’. If the variable's value is d41528 1 a41528 1 ‘-var-update’ list. d41541 1 a41541 1 The ‘-var-update’ Command d41553 2 a41554 2 ‘-var-evaluate-expression’ before and after the ‘-var-update’ is different. If ‘*’ is used as the variable object names, all existing d41558 2 a41559 2 this option are the same as for ‘-var-list-children’ (*note -var-list-children::). It is recommended to use the ‘--all-values’ d41562 1 a41562 1 With the ‘*’ parameter, if a variable object is bound to a currently d41565 1 a41565 1 If ‘-var-set-update-range’ was previously used on a varobj, then only d41568 2 a41569 2 ‘-var-update’ reports all the changed varobjs in a tuple named ‘changelist’. d41573 1 a41573 1 ‘name’ d41576 1 a41576 1 ‘value’ d41580 1 a41580 1 ‘in_scope’ d41583 1 a41583 1 ‘"true"’ d41586 1 a41586 1 ‘"false"’ d41591 1 a41591 1 ‘"invalid"’ d41594 1 a41594 1 either through recompilation or by using the GDB ‘file’ d41602 1 a41602 1 ‘type_changed’ d41604 2 a41605 2 changed, then this will be the string ‘true’; otherwise it will be ‘false’. d41609 2 a41610 2 automatically deleted when this attribute is ‘true’. Also, the varobj's update range, when set using the ‘-var-set-update-range’ d41613 1 a41613 1 ‘new_type’ d41617 1 a41617 1 ‘new_num_children’ d41621 1 a41621 1 The ‘numchild’ field in other varobj responses is generally not d41627 1 a41627 1 The ‘new_num_children’ attribute only reports changes to the number d41632 1 a41632 1 ‘displayhint’ d41635 1 a41635 1 ‘has_more’ d41639 2 a41640 2 ‘dynamic’ This attribute will be present and have the value ‘1’ if the varobj d41644 1 a41644 1 ‘new_children’ d41646 1 a41646 1 update range (as set by ‘-var-set-update-range’), then they will be d41661 1 a41661 1 The ‘-var-set-frozen’ Command d41670 1 a41670 1 parameter should be either ‘1’ to make the variable frozen or ‘0’ to d41672 2 a41673 2 nor any of its children, are implicitly updated by ‘-var-update’ of a parent variable or by ‘-var-update *’. Only ‘-var-update’ of the d41676 2 a41677 2 subsequent ‘-var-update’ operations. Unfreezing a variable does not update it, only subsequent ‘-var-update’ does. d41687 1 a41687 1 The ‘-var-set-update-range’ command d41696 1 a41696 1 ‘-var-update’. d41710 1 a41710 1 The ‘-var-set-visualizer’ command d41720 1 a41720 1 VISUALIZER is the visualizer to use. The special value ‘None’ means d41723 1 a41723 1 If not ‘None’, VISUALIZER must be a Python expression. This d41731 1 a41731 1 The pre-defined function ‘gdb.default_visualizer’ may be used to d41737 1 a41737 1 command ‘-list-features’ (*note GDB/MI Support Commands::) can be used d41755 1 a41755 1 Suppose ‘SomeClass’ is a visualizer class. A lambda expression can d41774 1 a41774 1 The ‘-data-disassemble’ Command d41790 3 a41792 3 ‘START-ADDR’ is the beginning address (or ‘$pc’) ‘END-ADDR’ d41794 1 a41794 1 ‘ADDR’ d41799 1 a41799 1 ‘FILENAME’ d41801 1 a41801 1 ‘LINENUM’ d41803 1 a41803 1 ‘LINES’ d41811 1 a41811 1 ‘OPCODES-MODE’ d41813 1 a41813 1 ‘none’ d41816 1 a41816 1 ‘bytes’ d41818 1 a41818 1 formatted as for ‘disassemble /b’. d41820 1 a41820 1 ‘display’ d41822 4 a41825 4 formatted as for ‘disassemble /r’. ‘MODE’ the use of MODE is deprecated in favour of using the ‘--opcodes’ and ‘--source’ options. When no MODE is given, MODE 0 will be d41828 1 a41828 1 ‘0’ d41832 1 a41832 1 ‘1’ d41834 2 a41835 2 possible to recreate this mode using ‘--opcodes’ and ‘--source’ options. d41837 1 a41837 1 ‘2’ d41839 1 a41839 1 using MODE 0 and passing ‘--opcodes bytes’ to the command. d41841 1 a41841 1 ‘3’ d41843 2 a41844 2 it is not possible to recreate this mode using ‘--opcodes’ and ‘--source’ options. d41846 1 a41846 1 ‘4’ d41848 1 a41848 1 using MODE 0 and passing ‘--source’ to the command. d41850 1 a41850 1 ‘5’ d41852 2 a41853 2 equivalent to using MODE 0 and passing ‘--opcodes bytes’ and ‘--source’ to the command. d41856 2 a41857 2 discussion of the difference between ‘/m’ and ‘/s’ output of the ‘disassemble’ command. d41859 1 a41859 1 The ‘--source’ can only be used with MODE 0. Passing this option d41866 3 a41868 3 The result of the ‘-data-disassemble’ command will be a list named ‘asm_insns’, the contents of this list depend on the options used with the ‘-data-disassemble’ command. d41870 2 a41871 2 For modes 0 and 2, and when the ‘--source’ option is not used, the ‘asm_insns’ list contains tuples with the following fields: d41873 1 a41873 1 ‘address’ d41876 1 a41876 1 ‘func-name’ d41879 2 a41880 2 ‘offset’ The decimal offset in bytes from the start of ‘func-name’. d41882 2 a41883 2 ‘inst’ The text disassembly for this ‘address’. d41885 1 a41885 1 ‘opcodes’ d41887 2 a41888 2 ‘--opcodes’ option ‘bytes’ or ‘display’ is used. This contains the raw opcode bytes for the ‘inst’ field. d41890 2 a41891 2 When the ‘--opcodes’ option is not passed to ‘-data-disassemble’, or the ‘bytes’ value is passed to ‘--opcodes’, then the bytes are d41894 2 a41895 2 equivalent to the ‘/b’ option being used with the ‘disassemble’ command (*note ‘disassemble’: disassemble.). d41897 1 a41897 1 When ‘--opcodes’ is passed the value ‘display’ then the bytes are d41900 2 a41901 2 byte-swapped. This format is equivalent to the ‘/r’ option being used with the ‘disassemble’ command. d41903 2 a41904 2 For modes 1, 3, 4 and 5, or when the ‘--source’ option is used, the ‘asm_insns’ list contains tuples named ‘src_and_asm_line’, each of which d41907 2 a41908 2 ‘line’ The line number within ‘file’. d41910 1 a41910 1 ‘file’ d41915 2 a41916 2 ‘fullname’ Absolute file name of ‘file’. It is converted to a canonical form d41924 5 a41928 5 ‘line_asm_insn’ This is a list of tuples containing the disassembly for ‘line’ in ‘file’. The fields of each tuple are the same as for ‘-data-disassemble’ in MODE 0 and 2, so ‘address’, ‘func-name’, ‘offset’, ‘inst’, and optionally ‘opcodes’. d41930 1 a41930 1 Note that whatever included in the ‘inst’ field, is not manipulated d41936 1 a41936 1 The corresponding GDB command is ‘disassemble’. d41941 1 a41941 1 Disassemble from the current value of ‘$pc’ to ‘$pc + 20’: d41959 1 a41959 1 Disassemble the whole ‘main’ function. Line 32 is part of ‘main’. d41974 1 a41974 1 Disassemble 3 instructions from the start of ‘main’: d41987 1 a41987 1 Disassemble 3 instructions from the start of ‘main’ in mixed mode: d42006 1 a42006 1 The ‘-data-evaluate-expression’ Command d42021 2 a42022 2 The corresponding GDB commands are ‘print’, ‘output’, and ‘call’. In ‘gdbtk’ only, there's a corresponding ‘gdb_eval’ command. d42028 1 a42028 1 “tokens” described in *note GDB/MI Command Syntax: GDB/MI Command d42044 1 a42044 1 The ‘-data-list-changed-registers’ Command d42057 2 a42058 2 GDB doesn't have a direct analog for this command; ‘gdbtk’ has the corresponding command ‘gdb_changed_register_list’. d42080 1 a42080 1 The ‘-data-list-register-names’ Command d42099 2 a42100 2 ‘-data-list-register-names’. In ‘gdbtk’ there is a corresponding command ‘gdb_regnames’. d42120 1 a42120 1 The ‘-data-list-register-values’ Command d42133 1 a42133 1 returned. The ‘--skip-unavailable’ option indicates that only the d42138 1 a42138 1 ‘x’ d42140 1 a42140 1 ‘o’ d42142 1 a42142 1 ‘t’ d42144 1 a42144 1 ‘d’ d42146 1 a42146 1 ‘r’ d42148 1 a42148 1 ‘N’ d42154 2 a42155 2 The corresponding GDB commands are ‘info reg’, ‘info all-reg’, and (in ‘gdbtk’) ‘gdb_fetch_registers’. d42207 1 a42207 1 The ‘-data-read-memory’ Command d42210 1 a42210 1 This command is deprecated, use ‘-data-read-memory-bytes’ instead. d42221 1 a42221 1 ‘ADDRESS’ d42226 1 a42226 1 ‘WORD-FORMAT’ d42228 1 a42228 1 the same as for GDB's ‘print’ command (*note Output Formats: Output d42231 1 a42231 1 ‘WORD-SIZE’ d42234 1 a42234 1 ‘NR-ROWS’ d42237 1 a42237 1 ‘NR-COLS’ d42240 1 a42240 1 ‘ASCHAR’ d42247 1 a42247 1 ‘BYTE-OFFSET’ d42251 2 a42252 2 NR-COLS words, each word being WORD-SIZE bytes. In total, ‘NR-ROWS * NR-COLS * WORD-SIZE’ bytes are read (returned as ‘total-bytes’). Should d42254 3 a42256 3 missing words are identified using ‘N/A’. The number of bytes read from the target is returned in ‘nr-bytes’ and the starting address used to read memory in ‘addr’. d42259 1 a42259 1 ‘next-row’ and ‘prev-row’, ‘next-page’ and ‘prev-page’. d42264 1 a42264 1 The corresponding GDB command is ‘x’. ‘gdbtk’ has ‘gdb_get_mem’ memory d42270 1 a42270 1 Read six bytes of memory starting at ‘bytes+6’ but then offset by ‘-6’ d42284 1 a42284 1 Read two bytes of memory starting at address ‘shorts + 64’ and d42295 2 a42296 2 Read thirty two bytes of memory starting at ‘bytes+16’ and format as eight rows of four columns. Include a string encoding with ‘x’ used as d42314 1 a42314 1 The ‘-data-read-memory-bytes’ Command d42325 1 a42325 1 ‘ADDRESS’ d42330 1 a42330 1 ‘COUNT’ d42334 1 a42334 1 ‘OFFSET’ d42357 1 a42357 1 the command includes a field named ‘memory’ whose content is a list of d42361 1 a42361 1 ‘begin’ d42364 1 a42364 1 ‘end’ d42367 1 a42367 1 ‘offset’ d42369 1 a42369 1 the start address passed to ‘-data-read-memory-bytes’. d42371 1 a42371 1 ‘contents’ d42377 1 a42377 1 The corresponding GDB command is ‘x’. d42389 1 a42389 1 The ‘-data-write-memory-bytes’ Command d42400 1 a42400 1 ‘ADDRESS’ d42405 1 a42405 1 ‘CONTENTS’ d42409 1 a42409 1 ‘COUNT’ d42441 1 a42441 1 The ‘-trace-find’ Command d42453 1 a42453 1 ‘none’ d42456 1 a42456 1 ‘frame-number’ d42460 1 a42460 1 ‘tracepoint-number’ d42464 1 a42464 1 ‘pc’ d42468 1 a42468 1 ‘pc-inside-range’ d42473 1 a42473 1 ‘pc-outside-range’ d42479 1 a42479 1 ‘line’ d42484 1 a42484 1 If ‘none’ was passed as MODE, the response does not have fields. d42487 2 a42488 2 ‘found’ This field has either ‘0’ or ‘1’ as the value, depending on whether d42491 1 a42491 1 ‘traceframe’ d42493 1 a42493 1 ‘found’ field has value of ‘1’. d42495 1 a42495 1 ‘tracepoint’ d42497 1 a42497 1 ‘found’ field has value of ‘1’. d42499 1 a42499 1 ‘frame’ d42507 1 a42507 1 The corresponding GDB command is ‘tfind’. d42509 1 a42509 1 The ‘-trace-define-variable’ Command d42519 1 a42519 1 that value. Note that the NAME should start with the ‘$’ character. d42524 1 a42524 1 The corresponding GDB command is ‘tvariable’. d42526 1 a42526 1 The ‘-trace-frame-collected’ Command d42554 3 a42556 3 the object collected in its entirety would be ‘myVar’. The object ‘myArray’ would be partially collected, because only the element at index ‘myIndex’ would be collected. The remaining objects would be d42582 1 a42582 1 ‘explicit-variables’ d42586 1 a42586 1 The ‘--var-print-values’ option affects how or whether the value d42592 1 a42592 1 ‘computed-expressions’ d42594 3 a42596 3 current trace frame. The ‘--comp-print-values’ option affects this set like the ‘--var-print-values’ option affects the ‘explicit-variables’ set. See above. d42598 1 a42598 1 ‘registers’ d42602 2 a42603 2 ‘--registers-format’ option. See the ‘-data-list-register-values’ command for a list of the allowed formats. The default is ‘x’. d42605 1 a42605 1 ‘tvars’ d42610 1 a42610 1 ‘memory’ d42615 1 a42615 1 ‘address’ d42618 1 a42618 1 ‘length’ d42621 1 a42621 1 ‘contents’ d42623 1 a42623 1 present if the ‘--memory-contents’ option is specified. d42633 1 a42633 1 The ‘-trace-list-variables’ Command d42644 1 a42644 1 ‘name’ d42647 1 a42647 1 ‘initial’ d42651 1 a42651 1 ‘current’ d42660 1 a42660 1 The corresponding GDB command is ‘tvariables’. d42675 1 a42675 1 The ‘-trace-save’ Command d42683 1 a42683 1 Saves the collected trace data to FILENAME. Without the ‘-r’ option, d42685 1 a42685 1 the ‘-r’ option the target is asked to perform the save. d42688 1 a42688 1 You can supply the optional ‘-ctf’ argument to save it the CTF format. d42694 1 a42694 1 The corresponding GDB command is ‘tsave’. d42696 1 a42696 1 The ‘-trace-start’ Command d42710 1 a42710 1 The corresponding GDB command is ‘tstart’. d42712 1 a42712 1 The ‘-trace-status’ Command d42723 4 a42726 4 ‘supported’ May have a value of either ‘0’, when no tracing operations are supported, ‘1’, when all tracing operations are supported, or ‘file’ when examining trace file. In the latter case, examining of d42730 2 a42731 2 ‘running’ May have a value of either ‘0’ or ‘1’ depending on whether tracing d42733 1 a42733 1 ‘supported’ field is not ‘0’. d42735 1 a42735 1 ‘stop-reason’ d42738 3 a42740 3 The value of ‘request’ means the tracing was stopped as result of the ‘-trace-stop’ command. The value of ‘overflow’ means the tracing buffer is full. The value of ‘disconnection’ means tracing d42742 1 a42742 1 ‘passcount’ means tracing was stopped when a tracepoint was passed d42744 1 a42744 1 present if ‘supported’ field is not ‘0’. d42746 1 a42746 1 ‘stopping-tracepoint’ d42748 2 a42749 2 is present iff the ‘stop-reason’ field has the value of ‘passcount’. d42751 4 a42754 4 ‘frames’ ‘frames-created’ The ‘frames’ field is a count of the total number of trace frames in the trace buffer, while ‘frames-created’ is the total created d42758 2 a42759 2 ‘buffer-size’ ‘buffer-free’ d42763 2 a42764 2 ‘circular’ The value of the circular trace buffer flag. ‘1’ means that the d42766 1 a42766 1 necessary to make room, ‘0’ means that the trace buffer is linear d42769 3 a42771 3 ‘disconnected’ The value of the disconnected tracing flag. ‘1’ means that tracing will continue after GDB disconnects, ‘0’ means that the trace run d42774 1 a42774 1 ‘trace-file’ d42781 1 a42781 1 The corresponding GDB command is ‘tstatus’. d42783 1 a42783 1 The ‘-trace-stop’ Command d42792 1 a42792 1 fields as ‘-trace-status’, except that the ‘supported’ and ‘running’ d42798 1 a42798 1 The corresponding GDB command is ‘tstop’. d42806 1 a42806 1 The ‘-symbol-info-functions’ Command d42821 1 a42821 1 The ‘--include-nondebug’ option causes the output to include code d42824 1 a42824 1 The options ‘--type’ and ‘--name’ allow the symbols returned to be d42828 1 a42828 1 The option ‘--max-results’ restricts the command to return no more d42835 1 a42835 1 The corresponding GDB command is ‘info functions’. d42906 1 a42906 1 The ‘-symbol-info-module-functions’ Command d42921 3 a42923 3 The option ‘--module’ only returns results for modules matching MODULE_REGEXP. The option ‘--name’ only returns functions whose name matches NAME_REGEXP, and ‘--type’ only returns functions whose type d42929 1 a42929 1 The corresponding GDB command is ‘info module functions’. d42967 1 a42967 1 The ‘-symbol-info-module-variables’ Command d42982 3 a42984 3 The option ‘--module’ only returns results for modules matching MODULE_REGEXP. The option ‘--name’ only returns variables whose name matches NAME_REGEXP, and ‘--type’ only returns variables whose type d42990 1 a42990 1 The corresponding GDB command is ‘info module variables’. d43038 1 a43038 1 The ‘-symbol-info-modules’ Command d43052 1 a43052 1 The option ‘--name’ allows the modules returned to be filtered based d43055 1 a43055 1 The option ‘--max-results’ restricts the command to return no more d43062 1 a43062 1 The corresponding GDB command is ‘info modules’. d43092 1 a43092 1 The ‘-symbol-info-types’ Command d43105 2 a43106 2 added to the debug information by the compiler, for example ‘int’, ‘float’, etc.; these types do not have an associated line number. d43108 1 a43108 1 The option ‘--name’ allows the list of types returned to be filtered d43111 1 a43111 1 The option ‘--max-results’ restricts the command to return no more d43118 1 a43118 1 The corresponding GDB command is ‘info types’. d43149 1 a43149 1 The ‘-symbol-info-variables’ Command d43165 1 a43165 1 The ‘--include-nondebug’ option causes the output to include data d43168 1 a43168 1 The options ‘--type’ and ‘--name’ allow the symbols returned to be d43172 1 a43172 1 The option ‘--max-results’ restricts the command to return no more d43179 1 a43179 1 The corresponding GDB command is ‘info variables’. d43254 1 a43254 1 The ‘-symbol-list-lines’ Command d43288 1 a43288 1 The ‘-file-exec-and-symbols’ Command d43306 1 a43306 1 The corresponding GDB command is ‘file’. d43316 1 a43316 1 The ‘-file-exec-file’ Command d43325 1 a43325 1 ‘-file-exec-and-symbols’, the symbol table is _not_ read from this file. d43333 1 a43333 1 The corresponding GDB command is ‘exec-file’. d43343 1 a43343 1 The ‘-file-list-exec-source-file’ Command d43353 1 a43353 1 information field has a value of ‘1’ or ‘0’ depending on whether or not d43359 1 a43359 1 The GDB equivalent is ‘info source’ d43369 1 a43369 1 The ‘-file-list-exec-source-files’ Command d43390 3 a43392 3 field DEBUG-FULLY-READ will be a string, either ‘true’ or ‘false’. When ‘true’, this indicates the full debug information for the compilation unit describing this file has been read in. When ‘false’, the full d43400 1 a43400 1 case-insensitive filesystem (e.g., MS-Windows). ‘--’ can be used before d43402 1 a43402 1 REGEXP starts with ‘-’). d43404 2 a43405 2 If ‘--dirname’ is provided, then REGEXP is matched only against the directory name of each source file. If ‘--basename’ is provided, then d43407 1 a43407 1 ‘--dirname’ or ‘--basename’ may be given, and if either is given then d43410 1 a43410 1 If ‘--group-by-objfile’ is used then the format of the results is d43417 1 a43417 1 ‘none’ d43419 1 a43419 1 ‘partially-read’ d43423 1 a43423 1 ‘fully-read’ d43434 2 a43435 2 The GDB equivalent is ‘info sources’. ‘gdbtk’ has an analogous command ‘gdb_listfiles’. d43501 1 a43501 1 The ‘-file-list-shared-libraries’ Command d43515 2 a43516 2 The corresponding GDB command is ‘info shared’. The fields have a similar meaning to the ‘=library-loaded’ notification. The ‘ranges’ d43520 1 a43520 1 ‘from’ d43522 1 a43522 1 ‘to’ d43535 1 a43535 1 The ‘-file-symbol-file’ Command d43550 1 a43550 1 The corresponding GDB command is ‘symbol-file’. d43566 1 a43566 1 The ‘-target-attach’ Command d43576 1 a43576 1 by ‘-list-thread-groups --available’ must be used. d43581 1 a43581 1 The corresponding GDB command is ‘attach’. d43593 1 a43593 1 The ‘-target-detach’ Command d43608 1 a43608 1 The corresponding GDB command is ‘detach’. d43618 1 a43618 1 The ‘-target-disconnect’ Command d43632 1 a43632 1 The corresponding GDB command is ‘disconnect’. d43642 1 a43642 1 The ‘-target-download’ Command d43653 1 a43653 1 ‘section’ d43655 1 a43655 1 ‘section-sent’ d43657 1 a43657 1 ‘section-size’ d43659 1 a43659 1 ‘total-sent’ d43662 1 a43662 1 ‘total-size’ d43671 1 a43671 1 ‘section’ d43673 1 a43673 1 ‘section-size’ d43675 1 a43675 1 ‘total-size’ d43683 1 a43683 1 The corresponding GDB command is ‘load’. d43749 1 a43749 1 The ‘-target-flash-erase’ Command d43759 1 a43759 1 The corresponding GDB command is ‘flash-erase’. d43769 1 a43769 1 The ‘-target-select’ Command d43779 3 a43781 3 ‘TYPE’ The type of target, for instance ‘remote’, etc. ‘PARAMETERS’ d43794 1 a43794 1 The corresponding GDB command is ‘target’. d43810 1 a43810 1 The ‘-target-file-put’ Command d43824 1 a43824 1 The corresponding GDB command is ‘remote put’. d43834 1 a43834 1 The ‘-target-file-get’ Command d43848 1 a43848 1 The corresponding GDB command is ‘remote get’. d43858 1 a43858 1 The ‘-target-file-delete’ Command d43871 1 a43871 1 The corresponding GDB command is ‘remote delete’. d43887 1 a43887 1 The ‘-info-ada-exceptions’ Command d43902 1 a43902 1 The corresponding GDB command is ‘info exceptions’. d43910 1 a43910 1 ‘name’ d43913 1 a43913 1 ‘address’ d43944 1 a43944 1 The ‘-info-gdb-mi-command’ Command d43954 1 a43954 1 Note that the dash (‘-’) starting all GDB/MI commands is technically d43969 3 a43971 3 ‘exists’ This field is equal to ‘"true"’ if the GDB/MI command exists, ‘"false"’ otherwise. d43987 1 a43987 1 The ‘-list-features’ Command d44008 6 a44013 6 ‘frozen-varobjs’ Indicates support for the ‘-var-set-frozen’ command, as well as possible presence of the ‘frozen’ field in the output of ‘-varobj-create’. ‘pending-breakpoints’ Indicates support for the ‘-f’ option to the ‘-break-insert’ d44015 1 a44015 1 ‘python’ d44017 8 a44024 8 commands, and possible presence of the ‘display_hint’ field in the output of ‘-var-list-children’ ‘thread-info’ Indicates support for the ‘-thread-info’ command. ‘data-read-memory-bytes’ Indicates support for the ‘-data-read-memory-bytes’ and the ‘-data-write-memory-bytes’ commands. ‘breakpoint-notifications’ d44027 4 a44030 4 ‘ada-task-info’ Indicates support for the ‘-ada-task-info’ command. ‘language-option’ Indicates that all GDB/MI commands accept the ‘--language’ option d44032 3 a44034 3 ‘info-gdb-mi-command’ Indicates support for the ‘-info-gdb-mi-command’ command. ‘undefined-command-error-code’ d44038 2 a44039 2 ‘exec-run-start-option’ Indicates that the ‘-exec-run’ command supports the ‘--start’ d44041 2 a44042 2 ‘data-disassemble-a-option’ Indicates that the ‘-data-disassemble’ command supports the ‘-a’ d44044 4 a44047 4 ‘simple-values-ref-types’ Indicates that the ‘--simple-values’ argument to the ‘-stack-list-arguments’, ‘-stack-list-locals’, ‘-stack-list-variables’, and ‘-var-list-children’ commands takes d44052 1 a44052 1 The ‘-list-target-features’ Command d44057 1 a44057 1 reported by the ‘-list-features’ command, the features depend on which d44059 1 a44059 1 commands such as ‘-target-select’, ‘-target-attach’ or ‘-exec-run’, the d44068 1 a44068 1 ‘async’ d44073 1 a44073 1 ‘reverse’ d44083 1 a44083 1 The ‘-gdb-exit’ Command d44096 1 a44096 1 Approximately corresponds to ‘quit’. d44105 1 a44105 1 The ‘-gdb-set’ Command d44118 1 a44118 1 The corresponding GDB command is ‘set’. d44128 1 a44128 1 The ‘-gdb-show’ Command d44141 1 a44141 1 The corresponding GDB command is ‘show’. d44151 1 a44151 1 The ‘-gdb-version’ Command d44164 1 a44164 1 The GDB equivalent is ‘show version’. GDB by default shows this d44185 1 a44185 1 The ‘-list-thread-groups’ Command d44200 1 a44200 1 the ‘--available’ option, GDB reports thread groups available on the d44203 2 a44204 2 The output of this command may have either a ‘threads’ result or a ‘groups’ result. The ‘thread’ result has a list of tuples as value, d44206 1 a44206 1 The ‘groups’ result has a list of tuples as value, each tuple describing d44209 1 a44209 1 always has a ‘groups’ result. The format of the ‘group’ result is d44213 1 a44213 1 groups together with their children, by passing the ‘--recurse’ option d44216 1 a44216 1 will also include its children, either as ‘group’ or ‘threads’ field. d44221 3 a44223 3 • When a single thread group is passed, the output will typically be the ‘threads’ result. Because threads may not contain anything, the ‘recurse’ option will be ignored. d44225 1 a44225 1 • When the ‘--available’ option is passed, limited information may be d44229 1 a44229 1 The frontend should assume that ‘-list-thread-groups --available’ d44232 1 a44232 1 The ‘groups’ result is a list of tuples, where each tuple may have d44235 1 a44235 1 ‘id’ d44240 2 a44241 2 ‘type’ The type of the thread group. At present, only ‘process’ is a d44244 1 a44244 1 ‘pid’ d44246 1 a44246 1 for thread groups of type ‘process’ and only if the process exists. d44248 1 a44248 1 ‘exit-code’ d44251 1 a44251 1 ‘process’ and only if the process is not running. d44253 1 a44253 1 ‘num_children’ d44257 1 a44257 1 ‘threads’ d44259 1 a44259 1 thread. It may be present if the ‘--recurse’ option is specified, d44262 1 a44262 1 ‘cores’ d44267 1 a44267 1 ‘executable’ d44270 1 a44270 1 ‘process’, and only if there is a corresponding executable file. d44295 1 a44295 1 The ‘-info-os’ Command d44314 1 a44314 1 The corresponding GDB command is ‘info os’. d44363 2 a44364 2 (Note that the MI output here includes a ‘"Title"’ column that does not appear in command-line ‘info os’; this column is useful for MI d44366 1 a44366 1 menu, but is needless clutter on the command line, and ‘info os’ omits d44369 1 a44369 1 The ‘-add-inferior’ Command d44379 1 a44379 1 association may be established with the ‘-file-exec-and-symbols’ command d44384 5 a44388 5 inferior was connected to ‘gdbserver’ with ‘target remote’, then the new inferior will be connected to the same ‘gdbserver’ instance. The ‘--no-connection’ option starts the new inferior with no connection yet. You can then for example use the ‘-target-select remote’ command to connect to some other ‘gdbserver’ instance, use ‘-exec-run’ to spawn a d44399 1 a44399 1 ‘number’ d44402 1 a44402 1 ‘name’ d44408 1 a44408 1 The corresponding GDB command is ‘add-inferior’ (*note ‘add-inferior’: d44418 1 a44418 1 The ‘-remove-inferior’ Command d44429 1 a44429 1 the ‘-add-inferior’ command. d44431 1 a44431 1 When an inferior is successfully removed a ‘=thread-group-removed’ d44438 2 a44439 2 The corresponding GDB command is ‘remove-inferiors’ (*note ‘remove-inferiors’: remove_inferiors_cli.). d44449 1 a44449 1 The ‘-interpreter-exec’ Command d44462 1 a44462 1 The corresponding GDB command is ‘interpreter-exec’. d44475 1 a44475 1 The ‘-inferior-tty-set’ Command d44488 1 a44488 1 The corresponding GDB command is ‘set inferior-tty’ /dev/pts/1. d44498 1 a44498 1 The ‘-inferior-tty-show’ Command d44511 1 a44511 1 The corresponding GDB command is ‘show inferior-tty’. d44524 1 a44524 1 The ‘-enable-timings’ Command d44535 1 a44535 1 equivalent to ‘yes’. d44568 1 a44568 1 The ‘-complete’ Command d44587 1 a44587 1 ‘completion’ d44591 1 a44591 1 ‘matches’ d44595 4 a44598 4 ‘max_completions_reached’ This field contains ‘1’ if number of known completions is above ‘max-completions’ limit (*note Completion::), otherwise it contains ‘0’. It is always present. d44603 1 a44603 1 The corresponding GDB command is ‘complete’. d44661 1 a44661 1 Annotations start with a newline character, two ‘control-z’ characters, d44669 1 a44669 1 Any output not beginning with a newline and two ‘control-z’ d44671 1 a44671 1 for GDB to output a newline followed by two ‘control-z’ characters, but d44673 1 a44673 1 ‘escape’ annotation which means those three characters as output. d44675 1 a44675 1 The annotation LEVEL, which is specified using the ‘--annotate’ d44684 2 a44685 2 ‘set annotate LEVEL’ The GDB command ‘set annotate’ sets the level of annotations to the d44688 1 a44688 1 ‘show annotate’ d44714 2 a44715 2 Here ‘quit’ is input to GDB; the rest is output from GDB. The three lines beginning ‘^Z^Z’ (where ‘^Z’ denotes a ‘control-z’ character) are d44724 1 a44724 1 If you prefix a command with ‘server ’ then it will not affect the d44730 1 a44730 1 The ‘server ’ prefix does not affect the recording of values into the d44732 1 a44732 1 history, use the ‘output’ command instead of the ‘print’ command. d44747 2 a44748 2 Different kinds of input each have a different “input type”. Each input type has three annotations: a ‘pre-’ annotation, which denotes the d44750 1 a44750 1 denotes the end of the prompt, and then a ‘post-’ annotation which d44752 1 a44752 1 the input. For example, the ‘prompt’ input type features the following d44761 1 a44761 1 ‘prompt’ d44764 2 a44765 2 ‘commands’ When GDB prompts for a set of commands, like in the ‘commands’ d44769 1 a44769 1 ‘overload-choice’ d44773 1 a44773 1 ‘query’ d44777 1 a44777 1 ‘prompt-for-continue’ d44779 1 a44779 1 Don't expect this to work well; instead use ‘set height 0’ to d44799 2 a44800 2 ‘value-history-begin’ annotation is followed by a ‘error’, one cannot expect to receive the matching ‘value-history-end’. One cannot expect d44823 1 a44823 1 ‘^Z^Zframes-invalid’ d44825 1 a44825 1 The frames (for example, output from the ‘backtrace’ command) may d44828 1 a44828 1 ‘^Z^Zbreakpoints-invalid’ d44839 2 a44840 2 When the program starts executing due to a GDB command such as ‘step’ or ‘continue’, d44848 1 a44848 1 is output. Before the ‘stopped’ annotation, a variety of annotations d44851 1 a44851 1 ‘^Z^Zexited EXIT-STATUS’ d44855 2 a44856 2 ‘^Z^Zsignalled’ The program exited with a signal. After the ‘^Z^Zsignalled’, the d44869 3 a44871 3 where NAME is the name of the signal, such as ‘SIGILL’ or ‘SIGSEGV’, and STRING is the explanation of the signal, such as ‘Illegal Instruction’ or ‘Segmentation fault’. The arguments d44875 2 a44876 2 ‘^Z^Zsignal’ The syntax of this annotation is just like ‘signalled’, but GDB is d44880 1 a44880 1 ‘^Z^Zbreakpoint NUMBER’ d44883 1 a44883 1 ‘^Z^Zwatchpoint NUMBER’ d44900 2 a44901 2 necessarily point to the beginning of a line), MIDDLE is ‘middle’ if ADDR is in the middle of the line, or ‘beg’ if ADDR is at the beginning d44903 1 a44903 1 with the source which is being displayed. The ADDR is in the form ‘0x’ d44920 1 a44920 1 GDB defines some parameters that can be passed to the ‘launch’ d44923 1 a44923 1 ‘args’ d44925 2 a44926 2 provided as command-line arguments to the inferior, as if by ‘set args’. *Note Arguments::. d44928 1 a44928 1 ‘cwd’ d44930 1 a44930 1 directory to this directory, as if by the ‘cd’ command (*note d44933 2 a44934 2 before the ‘program’ parameter is processed. This will affect the result if ‘program’ is a relative filename. d44936 1 a44936 1 ‘env’ d44943 1 a44943 1 ‘program’ d44945 1 a44945 1 This corresponds to the ‘file’ command. *Note Files::. d44947 2 a44948 2 ‘stopAtBeginningOfMainSubprogram’ If provided, this must be a boolean. When ‘True’, GDB will set a d44950 1 a44950 1 same approach as the ‘start’ command. *Note Starting::. d44952 3 a44954 3 GDB defines some parameters that can be passed to the ‘attach’ request. Either ‘pid’ or ‘target’ must be specified, but if both are specified then ‘target’ will be ignored. d44956 1 a44956 1 ‘pid’ d44959 1 a44959 1 ‘program’ d44961 1 a44961 1 This corresponds to the ‘file’ command. *Note Files::. In some d44966 1 a44966 1 ‘target’ d44968 1 a44968 1 passed to the ‘target remote’ command. *Note Connecting::. d44970 1 a44970 1 In response to the ‘disassemble’ request, DAP allows the client to d44973 1 a44973 1 in hex, like ‘"55a2b900"’. d44975 1 a44975 1 When the ‘repl’ context is used for the ‘evaluate’ request, GDB d44979 1 a44979 1 For example, evaluating the ‘continue’ command could do this, as could d44982 1 a44982 1 ‘repl’ evaluation can also cause GDB to appear to stop responding to d44985 2 a44986 2 Evaluations like this can be interrupted using the DAP ‘cancel’ request. (In fact, ‘cancel’ should work for any request, but it is d44990 1 a44990 1 mode. These can be set on the command line using the ‘-iex’ option d44993 1 a44993 1 ‘set debug dap-log-file [FILENAME]’ d44997 2 a44998 2 ‘set debug dap-log-level LEVEL’ Set the DAP logging level. The default is ‘1’, which logs the DAP d45000 1 a45000 1 useful, and unexpected exceptions. Level ‘2’ can be used to log d45011 1 a45011 1 This chapter documents GDB's “just-in-time” (JIT) compilation interface. d45097 1 a45097 1 • Generate an object file in memory with symbols and other desired d45101 1 a45101 1 • Create a code entry for the file, which gives the start and size of d45104 1 a45104 1 • Add it to the linked list in the JIT descriptor. d45106 1 a45106 1 • Point the relevant_entry field of the descriptor at the entry. d45108 2 a45109 2 • Set ‘action_flag’ to ‘JIT_REGISTER’ and call ‘__jit_debug_register_code’. d45112 1 a45112 1 ‘relevant_entry’ pointer so it doesn't have to walk the list looking for d45125 1 a45125 1 • Remove the code entry corresponding to the code from the linked d45128 1 a45128 1 • Point the ‘relevant_entry’ field of the descriptor at the code d45131 2 a45132 2 • Set ‘action_flag’ to ‘JIT_UNREGISTER’ and call ‘__jit_debug_register_code’. d45151 2 a45152 2 ‘gdb/jit-reader.in’, which is also installed as a header at ‘INCLUDEDIR/gdb/jit-reader.h’ for easy inclusion. d45156 2 a45157 2 at runtime). Two GDB commands, ‘jit-reader-load’ and ‘jit-reader-unload’ are provided, to be used to load and unload the d45172 2 a45173 2 Readers can be loaded and unloaded using the ‘jit-reader-load’ and ‘jit-reader-unload’ commands. d45175 1 a45175 1 ‘jit-reader-load READER’ d45179 2 a45180 2 directory, usually ‘LIBDIR/gdb/’ on a UNIX system (here LIBDIR is the system library directory, often ‘/usr/local/lib’). d45185 2 a45186 2 current one using ‘jit-reader-unload’ and then invoking ‘jit-reader-load’. d45188 1 a45188 1 ‘jit-reader-unload’ d45198 1 a45198 1 certain ABI. This ABI is described in ‘jit-reader.h’. d45200 1 a45200 1 ‘jit-reader.h’ defines the structures, macros and functions required d45202 1 a45202 1 ‘INCLUDEDIR/gdb’ where INCLUDEDIR is the system include directory. d45206 1 a45206 1 ‘GDB_DECLARE_GPL_COMPATIBLE_READER’ in a source file. d45208 1 a45208 1 The entry point for readers is the symbol ‘gdb_init_reader’, which is d45213 1 a45213 1 ‘struct gdb_reader_funcs’ contains a set of pointers to callback d45215 2 a45216 2 generated by the JIT compiler (‘read’), to unwind stack frames (‘unwind’) and to create canonical frame IDs (‘get_frame_id’). It also d45218 1 a45218 1 (‘destroy’). The struct looks like this d45235 3 a45237 3 their job. For ‘read’, these callbacks are passed in a ‘struct gdb_symbol_callbacks’ and for ‘unwind’ and ‘get_frame_id’, in a ‘struct gdb_unwind_callbacks’. ‘struct gdb_symbol_callbacks’ has callbacks to d45239 1 a45239 1 ‘struct gdb_unwind_callbacks’ has callbacks to read registers off the d45241 1 a45241 1 previous frame. Both have a callback (‘target_read’) to read bytes off d45266 2 a45267 2 reduce the number of operations performed by debugger. The “In-Process Agent”, a shared library, is running within the same process with d45282 1 a45282 1 ‘set agent on’ d45291 1 a45291 1 ‘set agent off’ d45295 1 a45295 1 ‘show agent’ d45331 1 a45331 1 complex data types called “objects”. d45368 1 a45368 1 addr 8 if BASEREG is ‘-1’, ADDR is the d45420 1 a45420 1 ‘FastTrace:TRACEPOINT_OBJECT GDB_JUMP_PAD_HEAD’ d45423 1 a45423 1 is the head of “jumppad”, which is used to jump to data collection d45427 1 a45427 1 ‘OK TARGET_ADDRESS GDB_JUMP_PAD_HEAD FJUMP_SIZE FJUMP’ d45434 1 a45434 1 ‘close’ d45438 1 a45438 1 ‘qTfSTM’ d45440 1 a45440 1 ‘qTsSTM’ d45442 1 a45442 1 ‘qTSTMat’ d45444 1 a45444 1 ‘probe_marker_at:ADDRESS’ d45448 1 a45448 1 ‘unprobe_marker_at:ADDRESS’ d45481 1 a45481 1 • If the debugger gets a fatal signal, for any input whatever, that d45484 1 a45484 1 • If GDB produces an error message for valid input, that is a bug. d45488 1 a45488 1 • If GDB does not produce an error message for invalid input, that is d45493 1 a45493 1 • If you are an experienced user of debugging tools, your suggestions d45507 1 a45507 1 individuals in the file ‘etc/SERVICE’ in the GNU Emacs distribution. d45538 2 a45539 2 • The version of GDB. GDB announces it if you start with no arguments; you can also print it at any time using ‘show version’. d45544 1 a45544 1 • The type of machine you are using, and the operating system name d45547 3 a45549 3 • The details of the GDB build-time configuration. GDB shows these details if you invoke it with the ‘--configuration’ command-line option, or if you type ‘show configuration’ at GDB's prompt. d45551 1 a45551 1 • What compiler (and its version) was used to compile GDB--e.g. d45554 1 a45554 1 • What compiler (and its version) was used to compile the program you d45556 1 a45556 1 Compiler". For GCC, you can say ‘gcc --version’ to get this d45560 2 a45561 2 • The command arguments you gave the compiler to compile your example and observe the bug. For example, did you use ‘-O’? To guarantee d45568 1 a45568 1 • A complete input script, and all necessary source files, that will d45571 1 a45571 1 • A description of what behavior you observe that you believe is d45590 3 a45592 3 program such as ‘script’, which is available on many Unix systems. Just run your GDB session inside ‘script’ and then include the ‘typescript’ file with your bug report. d45597 1 a45597 1 • If you wish to suggest changes to the GDB source, send us context d45607 1 a45607 1 • A description of the envelope of the bug. d45627 1 a45627 1 • A patch for the bug. d45645 1 a45645 1 • A guess about what the bug is or what it depends on. d45678 1 a45678 1 The text ‘C-k’ is read as 'Control-K' and describes the character d45681 1 a45681 1 The text ‘M-k’ is read as 'Meta-K' and describes the character d45692 1 a45692 1 _first_, and then typing . Either process is known as “metafying” d45695 2 a45696 2 The text ‘M-C-k’ is read as 'Meta-Control-k' and describes the character produced by “metafying” ‘C-k’. d45743 2 a45744 2 ‘C-b’ to move the cursor to the left, and then correct your mistake. Afterwards, you can move the cursor to the right with ‘C-f’. d45753 1 a45753 1 ‘C-b’ d45755 1 a45755 1 ‘C-f’ d45759 1 a45759 1 ‘C-d’ d45763 1 a45763 1 ‘C-_’ or ‘C-x C-u’ d45769 1 a45769 1 the character underneath the cursor, like ‘C-d’, rather than the d45780 1 a45780 1 commands have been added in addition to ‘C-b’, ‘C-f’, ‘C-d’, and . d45783 1 a45783 1 ‘C-a’ d45785 1 a45785 1 ‘C-e’ d45787 1 a45787 1 ‘M-f’ d45790 1 a45790 1 ‘M-b’ d45792 1 a45792 1 ‘C-l’ d45795 1 a45795 1 Notice how ‘C-f’ moves forward a character, while ‘M-f’ moves forward d45805 2 a45806 2 “Killing” text means to delete the text from the line, but to save it away for later use, usually by “yanking” (re-inserting) it back into the d45813 1 a45813 1 When you use a kill command, the text is saved in a “kill-ring”. Any d45821 1 a45821 1 ‘C-k’ d45825 1 a45825 1 ‘M-d’ d45828 1 a45828 1 as those used by ‘M-f’. d45830 1 a45830 1 ‘M-’ d45833 1 a45833 1 same as those used by ‘M-b’. d45835 1 a45835 1 ‘C-w’ d45837 1 a45837 1 than ‘M-’ because the word boundaries differ. d45839 1 a45839 1 Here is how to “yank” the text back into the line. Yanking means to d45842 1 a45842 1 ‘C-y’ d45846 1 a45846 1 ‘M-y’ d45848 1 a45848 1 if the prior command is ‘C-y’ or ‘M-y’. d45861 1 a45861 1 start of the line, you might type ‘M-- C-k’. d45865 1 a45865 1 sign (‘-’), then the sign of the argument will be negative. Once you d45868 1 a45868 1 ‘C-d’ command an argument of 10, you could type ‘M-1 0 C-d’, which will d45879 1 a45879 1 “incremental” and “non-incremental”. d45886 1 a45886 1 history for a particular string, type ‘C-r’. Typing ‘C-s’ searches d45888 1 a45888 1 ‘isearch-terminators’ variable are used to terminate an incremental d45890 1 a45890 1 ‘C-J’ characters will terminate an incremental search. ‘C-g’ will abort d45895 2 a45896 2 To find other matching entries in the history list, type ‘C-r’ or ‘C-s’ as appropriate. This will search backward or forward in the d45904 1 a45904 1 Readline remembers the last incremental search string. If two ‘C-r’s d45921 1 a45921 1 putting commands in an “inputrc” file, conventionally in his home d45923 3 a45925 3 environment variable ‘INPUTRC’. If that variable is unset, the default is ‘~/.inputrc’. If that file does not exist or cannot be read, the ultimate default is ‘/etc/inputrc’. d45930 1 a45930 1 In addition, the ‘C-x C-r’ command re-reads this init file, thus d45948 2 a45949 2 Blank lines are ignored. Lines beginning with a ‘#’ are comments. Lines beginning with a ‘$’ indicate conditional constructs (*note d45955 1 a45955 1 values of variables in Readline using the ‘set’ command within the d45961 1 a45961 1 binding to use ‘vi’ line editing commands: d45975 1 a45975 1 ‘bell-style’ d45977 3 a45979 3 bell. If set to ‘none’, Readline never rings the bell. If set to ‘visible’, Readline uses a visible bell if one is available. If set to ‘audible’ (the default), Readline d45982 2 a45983 2 ‘bind-tty-special-chars’ If set to ‘on’ (the default), Readline attempts to bind the d45987 2 a45988 2 ‘blink-matching-paren’ If set to ‘on’, Readline attempts to briefly move the cursor d45990 1 a45990 1 inserted. The default is ‘off’. d45992 2 a45993 2 ‘colored-completion-prefix’ If set to ‘on’, when listing completions, Readline displays d45996 2 a45997 2 value of the ‘LS_COLORS’ environment variable. The default is ‘off’. d45999 2 a46000 2 ‘colored-stats’ If set to ‘on’, Readline displays possible completions using d46002 2 a46003 2 definitions are taken from the value of the ‘LS_COLORS’ environment variable. The default is ‘off’. d46005 1 a46005 1 ‘comment-begin’ d46007 2 a46008 2 ‘insert-comment’ command is executed. The default value is ‘"#"’. d46010 1 a46010 1 ‘completion-display-width’ d46017 2 a46018 2 ‘completion-ignore-case’ If set to ‘on’, Readline performs filename matching and d46020 1 a46020 1 is ‘off’. d46022 3 a46024 3 ‘completion-map-case’ If set to ‘on’, and COMPLETION-IGNORE-CASE is enabled, Readline treats hyphens (‘-’) and underscores (‘_’) as d46026 1 a46026 1 and completion. The default value is ‘off’. d46028 1 a46028 1 ‘completion-prefix-display-length’ d46035 1 a46035 1 ‘completion-query-items’ d46043 1 a46043 1 never ask. The default limit is ‘100’. d46045 2 a46046 2 ‘convert-meta’ If set to ‘on’, Readline will convert characters with the d46049 2 a46050 2 to a meta-prefixed key sequence. The default value is ‘on’, but will be set to ‘off’ if the locale is one that contains d46053 2 a46054 2 ‘disable-completion’ If set to ‘On’, Readline will inhibit word completion. d46056 1 a46056 1 they had been mapped to ‘self-insert’. The default is ‘off’. d46058 2 a46059 2 ‘echo-control-characters’ When set to ‘on’, on operating systems that indicate they d46061 1 a46061 1 signal generated from the keyboard. The default is ‘on’. d46063 2 a46064 2 ‘editing-mode’ The ‘editing-mode’ variable controls which default set of key d46067 1 a46067 1 This variable can be set to either ‘emacs’ or ‘vi’. d46069 1 a46069 1 ‘emacs-mode-string’ d46075 1 a46075 1 Use the ‘\1’ and ‘\2’ escapes to begin and end sequences of d46077 1 a46077 1 control sequence into the mode string. The default is ‘@@’. d46079 2 a46080 2 ‘enable-bracketed-paste’ When set to ‘On’, Readline will configure the terminal in a d46085 1 a46085 1 editing commands. The default is ‘On’. d46087 2 a46088 2 ‘enable-keypad’ When set to ‘on’, Readline will try to enable the application d46090 1 a46090 1 the arrow keys. The default is ‘off’. d46092 2 a46093 2 ‘enable-meta-key’ When set to ‘on’, Readline will try to enable any meta d46096 1 a46096 1 characters. The default is ‘on’. d46098 3 a46100 3 ‘expand-tilde’ If set to ‘on’, tilde expansion is performed when Readline attempts word completion. The default is ‘off’. d46102 2 a46103 2 ‘history-preserve-point’ If set to ‘on’, the history code attempts to place the point d46105 2 a46106 2 history line retrieved with ‘previous-history’ or ‘next-history’. The default is ‘off’. d46108 1 a46108 1 ‘history-size’ d46117 3 a46119 3 ‘horizontal-scroll-mode’ This variable can be set to either ‘on’ or ‘off’. Setting it to ‘on’ means that the text of the lines being edited will d46122 1 a46122 1 a new screen line. This variable is automatically set to ‘on’ d46124 1 a46124 1 to ‘off’. d46126 2 a46127 2 ‘input-meta’ If set to ‘on’, Readline will enable eight-bit input (it will d46130 1 a46130 1 default value is ‘off’, but Readline will set it to ‘on’ if d46132 1 a46132 1 ‘meta-flag’ is a synonym for this variable. d46134 1 a46134 1 ‘isearch-terminators’ d46138 1 a46138 1 given a value, the characters and ‘C-J’ will terminate d46141 1 a46141 1 ‘keymap’ d46143 7 a46149 7 commands. Built-in ‘keymap’ names are ‘emacs’, ‘emacs-standard’, ‘emacs-meta’, ‘emacs-ctlx’, ‘vi’, ‘vi-move’, ‘vi-command’, and ‘vi-insert’. ‘vi’ is equivalent to ‘vi-command’ (‘vi-move’ is also a synonym); ‘emacs’ is equivalent to ‘emacs-standard’. Applications may add additional names. The default value is ‘emacs’. The value of the ‘editing-mode’ variable also affects the default keymap. d46151 1 a46151 1 ‘keyseq-timeout’ d46159 1 a46159 1 input source (‘rl_instream’ by default). The value is d46165 1 a46165 1 value is ‘500’. d46167 8 a46174 8 ‘mark-directories’ If set to ‘on’, completed directory names have a slash appended. The default is ‘on’. ‘mark-modified-lines’ This variable, when set to ‘on’, causes Readline to display an asterisk (‘*’) at the start of history lines which have been modified. This variable is ‘off’ by default. d46176 2 a46177 2 ‘mark-symlinked-directories’ If set to ‘on’, completed names which are symbolic links to d46179 1 a46179 1 ‘mark-directories’). The default is ‘off’. d46181 6 a46186 6 ‘match-hidden-files’ This variable, when set to ‘on’, causes Readline to match files whose names begin with a ‘.’ (hidden files) when performing filename completion. If set to ‘off’, the leading ‘.’ must be supplied by the user in the filename to be completed. This variable is ‘on’ by default. d46188 2 a46189 2 ‘menu-complete-display-prefix’ If set to ‘on’, menu completion displays the common prefix of d46191 1 a46191 1 cycling through the list. The default is ‘off’. d46193 2 a46194 2 ‘output-meta’ If set to ‘on’, Readline will display characters with the d46196 2 a46197 2 sequence. The default is ‘off’, but Readline will set it to ‘on’ if the locale contains eight-bit characters. d46199 2 a46200 2 ‘page-completions’ If set to ‘on’, Readline uses an internal ‘more’-like pager to d46202 1 a46202 1 variable is ‘on’ by default. d46204 2 a46205 2 ‘print-completions-horizontally’ If set to ‘on’, Readline will display completions with matches d46207 1 a46207 1 the screen. The default is ‘off’. d46209 3 a46211 3 ‘revert-all-at-newline’ If set to ‘on’, Readline will undo all changes to history lines before returning when ‘accept-line’ is executed. By d46213 1 a46213 1 undo lists across calls to ‘readline’. The default is ‘off’. d46215 1 a46215 1 ‘show-all-if-ambiguous’ d46217 1 a46217 1 If set to ‘on’, words which have more than one possible d46219 1 a46219 1 of ringing the bell. The default value is ‘off’. d46221 1 a46221 1 ‘show-all-if-unmodified’ d46224 1 a46224 1 ‘on’, words which have more than one possible completion d46228 1 a46228 1 default value is ‘off’. d46230 2 a46231 2 ‘show-mode-in-prompt’ If set to ‘on’, add a string to the beginning of the prompt d46234 1 a46234 1 EMACS-MODE-STRING). The default value is ‘off’. d46236 2 a46237 2 ‘skip-completed-text’ If set to ‘on’, this alters the default completion behavior d46244 2 a46245 2 completion when the cursor is after the ‘e’ in ‘Makefile’ will result in ‘Makefile’ rather than ‘Makefilefile’, assuming d46247 1 a46247 1 ‘off’. d46249 1 a46249 1 ‘vi-cmd-mode-string’ d46255 1 a46255 1 is available. Use the ‘\1’ and ‘\2’ escapes to begin and end d46258 1 a46258 1 default is ‘(cmd)’. d46260 1 a46260 1 ‘vi-ins-mode-string’ d46266 1 a46266 1 is available. Use the ‘\1’ and ‘\2’ escapes to begin and end d46269 1 a46269 1 default is ‘(ins)’. d46271 2 a46272 2 ‘visible-stats’ If set to ‘on’, a character denoting a file's type is appended d46274 1 a46274 1 default is ‘off’. d46300 3 a46302 3 In the example above, ‘C-u’ is bound to the function ‘universal-argument’, ‘M-DEL’ is bound to the function ‘backward-kill-word’, and ‘C-o’ is bound to run the macro d46304 1 a46304 1 ‘> output’ into the line). d46321 5 a46325 5 In the above example, ‘C-u’ is again bound to the function ‘universal-argument’ (just as it was in the first example), ‘‘C-x’ ‘C-r’’ is bound to the function ‘re-read-init-file’, and ‘ <[> <1> <1> <~>’ is bound to insert the text ‘Function Key 1’. d46330 1 a46330 1 ‘\C-’ d46332 1 a46332 1 ‘\M-’ d46334 1 a46334 1 ‘\e’ d46336 1 a46336 1 ‘\\’ d46338 1 a46338 1 ‘\"’ d46340 1 a46340 1 ‘\'’ d46346 1 a46346 1 ‘\a’ d46348 1 a46348 1 ‘\b’ d46350 1 a46350 1 ‘\d’ d46352 1 a46352 1 ‘\f’ d46354 1 a46354 1 ‘\n’ d46356 1 a46356 1 ‘\r’ d46358 1 a46358 1 ‘\t’ d46360 1 a46360 1 ‘\v’ d46362 1 a46362 1 ‘\NNN’ d46365 1 a46365 1 ‘\xHH’ d46373 2 a46374 2 character in the macro text, including ‘"’ and ‘'’. For example, the following binding will make ‘‘C-x’ \’ insert a single ‘\’ into d46389 2 a46390 2 ‘$if’ The ‘$if’ construct allows bindings to be made based on the editing d46396 6 a46401 6 ‘mode’ The ‘mode=’ form of the ‘$if’ directive is used to test whether Readline is in ‘emacs’ or ‘vi’ mode. This may be used in conjunction with the ‘set keymap’ command, for instance, to set bindings in the ‘emacs-standard’ and ‘emacs-ctlx’ keymaps only if Readline is starting out in ‘emacs’ mode. d46403 2 a46404 2 ‘term’ The ‘term=’ form may be used to include terminal-specific key d46407 7 a46413 7 ‘=’ is tested against both the full name of the terminal and the portion of the terminal name before the first ‘-’. This allows ‘sun’ to match both ‘sun’ and ‘sun-cmd’, for instance. ‘version’ The ‘version’ test may be used to perform comparisons against specific Readline versions. The ‘version’ expands to the d46415 1 a46415 1 includes ‘=’ (and ‘==’), ‘!=’, ‘<=’, ‘>=’, ‘<’, and ‘>’. The d46418 3 a46420 3 and an optional minor version (e.g., ‘7.1’). If the minor version is omitted, it is assumed to be ‘0’. The operator may be separated from the string ‘version’ and from the version d46427 1 a46427 1 ‘application’ d46440 1 a46440 1 ‘variable’ d46443 1 a46443 1 operators are ‘=’, ‘==’, and ‘!=’. The variable name must be d46449 1 a46449 1 ‘mode=emacs’ test described above: d46454 2 a46455 2 ‘$endif’ This command, as seen in the previous example, terminates an ‘$if’ d46458 2 a46459 2 ‘$else’ Commands in this branch of the ‘$if’ directive are executed if the d46462 1 a46462 1 ‘$include’ d46465 1 a46465 1 directive reads from ‘/etc/inputrc’: d46598 2 a46599 2 In the following descriptions, “point” refers to the current cursor position, and “mark” refers to a cursor position saved by the ‘set-mark’ d46601 1 a46601 1 “region”. d46609 1 a46609 1 ‘beginning-of-line (C-a)’ d46612 1 a46612 1 ‘end-of-line (C-e)’ d46615 1 a46615 1 ‘forward-char (C-f)’ d46618 1 a46618 1 ‘backward-char (C-b)’ d46621 1 a46621 1 ‘forward-word (M-f)’ d46625 1 a46625 1 ‘backward-word (M-b)’ d46629 1 a46629 1 ‘previous-screen-line ()’ d46636 1 a46636 1 ‘next-screen-line ()’ d46643 1 a46643 1 ‘clear-display (M-C-l)’ d46648 1 a46648 1 ‘clear-screen (C-l)’ d46652 1 a46652 1 ‘redraw-current-line ()’ d46661 1 a46661 1 ‘accept-line (Newline or Return)’ d46664 1 a46664 1 with ‘add_history()’. If this line is a modified history line, the d46667 1 a46667 1 ‘previous-history (C-p)’ d46671 1 a46671 1 ‘next-history (C-n)’ d46674 1 a46674 1 ‘beginning-of-history (M-<)’ d46677 1 a46677 1 ‘end-of-history (M->)’ d46681 1 a46681 1 ‘reverse-search-history (C-r)’ d46687 1 a46687 1 ‘forward-search-history (C-s)’ d46693 1 a46693 1 ‘non-incremental-reverse-search-history (M-p)’ d46699 1 a46699 1 ‘non-incremental-forward-search-history (M-n)’ d46705 1 a46705 1 ‘history-search-forward ()’ d46711 1 a46711 1 ‘history-search-backward ()’ d46717 1 a46717 1 ‘history-substring-search-forward ()’ d46723 1 a46723 1 ‘history-substring-search-backward ()’ d46729 1 a46729 1 ‘yank-nth-arg (M-C-y)’ d46735 1 a46735 1 argument N is computed, the argument is extracted as if the ‘!N’ d46738 1 a46738 1 ‘yank-last-arg (M-. or M-_)’ d46741 1 a46741 1 like ‘yank-nth-arg’. Successive calls to ‘yank-last-arg’ move back d46748 1 a46748 1 as if the ‘!$’ history expansion had been specified. d46750 1 a46750 1 ‘operate-and-get-next (C-o)’ d46763 1 a46763 1 ‘end-of-file (usually C-d)’ d46765 1 a46765 1 ‘stty’. If this character is read when there are no characters on d46769 1 a46769 1 ‘delete-char (C-d)’ d46771 1 a46771 1 same character as the tty EOF character, as ‘C-d’ commonly is, see d46774 1 a46774 1 ‘backward-delete-char (Rubout)’ d46778 1 a46778 1 ‘forward-backward-delete-char ()’ d46783 1 a46783 1 ‘quoted-insert (C-q or C-v)’ d46785 1 a46785 1 insert key sequences like ‘C-q’, for example. d46787 1 a46787 1 ‘tab-insert (M-)’ d46790 1 a46790 1 ‘self-insert (a, b, A, 1, !, ...)’ d46793 1 a46793 1 ‘bracketed-paste-begin ()’ d46799 1 a46799 1 was bound to ‘self-insert’ instead of executing any editing d46807 1 a46807 1 ‘transpose-chars (C-t)’ d46813 1 a46813 1 ‘transpose-words (M-t)’ d46818 1 a46818 1 ‘upcase-word (M-u)’ d46822 1 a46822 1 ‘downcase-word (M-l)’ d46826 1 a46826 1 ‘capitalize-word (M-c)’ d46830 1 a46830 1 ‘overwrite-mode ()’ d46834 2 a46835 2 ‘emacs’ mode; ‘vi’ mode does overwrite differently. Each call to ‘readline()’ starts in insert mode. d46837 1 a46837 1 In overwrite mode, characters bound to ‘self-insert’ replace the d46839 1 a46839 1 Characters bound to ‘backward-delete-char’ replace the character d46850 1 a46850 1 ‘kill-line (C-k)’ d46855 1 a46855 1 ‘backward-kill-line (C-x Rubout)’ d46860 1 a46860 1 ‘unix-line-discard (C-u)’ d46863 1 a46863 1 ‘kill-whole-line ()’ d46867 1 a46867 1 ‘kill-word (M-d)’ d46870 1 a46870 1 as ‘forward-word’. d46872 1 a46872 1 ‘backward-kill-word (M-)’ d46874 1 a46874 1 ‘backward-word’. d46876 1 a46876 1 ‘shell-transpose-words (M-C-t)’ d46880 2 a46881 2 boundaries are the same as ‘shell-forward-word’ and ‘shell-backward-word’. d46883 1 a46883 1 ‘unix-word-rubout (C-w)’ d46887 1 a46887 1 ‘unix-filename-rubout ()’ d46892 1 a46892 1 ‘delete-horizontal-space ()’ d46896 1 a46896 1 ‘kill-region ()’ d46900 1 a46900 1 ‘copy-region-as-kill ()’ d46904 1 a46904 1 ‘copy-backward-word ()’ d46906 1 a46906 1 are the same as ‘backward-word’. By default, this command is d46909 1 a46909 1 ‘copy-forward-word ()’ d46911 1 a46911 1 boundaries are the same as ‘forward-word’. By default, this d46914 1 a46914 1 ‘yank (C-y)’ d46917 1 a46917 1 ‘yank-pop (M-y)’ d46919 1 a46919 1 if the prior command is ‘yank’ or ‘yank-pop’. d46927 1 a46927 1 ‘digit-argument (M-0, M-1, ... M--)’ d46929 1 a46929 1 argument. ‘M--’ starts a negative argument. d46931 1 a46931 1 ‘universal-argument ()’ d46935 1 a46935 1 by digits, executing ‘universal-argument’ again ends the numeric d46950 1 a46950 1 ‘complete ()’ d46955 1 a46955 1 ‘possible-completions (M-?)’ d46958 2 a46959 2 for display to the value of ‘completion-display-width’, the value of the environment variable ‘COLUMNS’, or the screen width, in that d46962 1 a46962 1 ‘insert-completions (M-*)’ d46964 1 a46964 1 been generated by ‘possible-completions’. d46966 2 a46967 2 ‘menu-complete ()’ Similar to ‘complete’, but replaces the word to be completed with a d46969 1 a46969 1 execution of ‘menu-complete’ steps through the list of possible d46972 1 a46972 1 ‘bell-style’) and the original text is restored. An argument of N d46978 3 a46980 3 ‘menu-complete-backward ()’ Identical to ‘menu-complete’, but moves backward through the list of possible completions, as if ‘menu-complete’ had been given a d46983 1 a46983 1 ‘delete-char-or-list ()’ d46985 2 a46986 2 end of the line (like ‘delete-char’). If at the end of the line, behaves identically to ‘possible-completions’. This command is d46995 1 a46995 1 ‘start-kbd-macro (C-x ()’ d46998 1 a46998 1 ‘end-kbd-macro (C-x ))’ d47002 1 a47002 1 ‘call-last-kbd-macro (C-x e)’ d47006 1 a47006 1 ‘print-last-kbd-macro ()’ d47016 1 a47016 1 ‘re-read-init-file (C-x C-r)’ d47020 1 a47020 1 ‘abort (C-g)’ d47022 1 a47022 1 (subject to the setting of ‘bell-style’). d47024 1 a47024 1 ‘do-lowercase-version (M-A, M-B, M-X, ...)’ d47029 1 a47029 1 ‘prefix-meta ()’ d47031 1 a47031 1 meta key. Typing ‘ f’ is equivalent to typing ‘M-f’. d47033 1 a47033 1 ‘undo (C-_ or C-x C-u)’ d47036 1 a47036 1 ‘revert-line (M-r)’ d47038 1 a47038 1 ‘undo’ command enough times to get back to the beginning. d47040 1 a47040 1 ‘tilde-expand (M-~)’ d47043 1 a47043 1 ‘set-mark (C-@@)’ d47047 1 a47047 1 ‘exchange-point-and-mark (C-x C-x)’ d47052 1 a47052 1 ‘character-search (C-])’ d47057 1 a47057 1 ‘character-search-backward (M-C-])’ d47062 1 a47062 1 ‘skip-csi-sequence ()’ d47071 2 a47072 2 ‘insert-comment (M-#)’ Without a numeric argument, the value of the ‘comment-begin’ d47076 2 a47077 2 ‘comment-begin’, the value is inserted, otherwise the characters in ‘comment-begin’ are deleted from the beginning of the line. In d47080 1 a47080 1 ‘dump-functions ()’ d47086 1 a47086 1 ‘dump-variables ()’ d47092 1 a47092 1 ‘dump-macros ()’ d47098 2 a47099 2 ‘emacs-editing-mode (C-e)’ When in ‘vi’ command mode, this causes a switch to ‘emacs’ editing d47102 2 a47103 2 ‘vi-editing-mode (M-C-j)’ When in ‘emacs’ editing mode, this causes a switch to ‘vi’ editing d47112 1 a47112 1 While the Readline library does not have a full set of ‘vi’ editing d47114 1 a47114 1 The Readline ‘vi’ mode behaves as specified in the POSIX standard. d47116 4 a47119 4 In order to switch interactively between ‘emacs’ and ‘vi’ editing modes, use the command ‘M-C-j’ (bound to emacs-editing-mode when in ‘vi’ mode and to vi-editing-mode in ‘emacs’ mode). The Readline default is ‘emacs’ mode. d47121 2 a47122 2 When you enter a line in ‘vi’ mode, you are already placed in 'insertion' mode, as if you had typed an ‘i’. Pressing switches d47124 2 a47125 2 the standard ‘vi’ movement keys, move to previous history lines with ‘k’ and subsequent lines with ‘j’, and so forth. d47149 1 a47149 1 to the history expansion provided by ‘csh’. This section describes the d47161 2 a47162 2 called the “event”, and the portions of that line that are acted upon are called “words”. Various “modifiers” are available to manipulate the d47166 1 a47166 1 history expansion character, which is ‘!’ by default. d47192 1 a47192 1 ‘!’ d47194 1 a47194 1 the end of the line, or ‘=’. d47196 1 a47196 1 ‘!N’ d47199 1 a47199 1 ‘!-N’ d47202 2 a47203 2 ‘!!’ Refer to the previous command. This is a synonym for ‘!-1’. d47205 1 a47205 1 ‘!STRING’ d47209 1 a47209 1 ‘!?STRING[?]’ d47211 1 a47211 1 the history list containing STRING. The trailing ‘?’ may be d47216 1 a47216 1 ‘^STRING1^STRING2^’ d47218 1 a47218 1 with STRING2. Equivalent to ‘!!:s^STRING1^STRING2^’. d47220 1 a47220 1 ‘!#’ d47229 1 a47229 1 Word designators are used to select desired words from the event. A ‘:’ d47231 1 a47231 1 omitted if the word designator begins with a ‘^’, ‘$’, ‘*’, ‘-’, or ‘%’. d47238 1 a47238 1 ‘!!’ d47242 1 a47242 1 ‘!!:$’ d47244 1 a47244 1 shortened to ‘!$’. d47246 1 a47246 1 ‘!fi:2’ d47248 1 a47248 1 with the letters ‘fi’. d47252 2 a47253 2 ‘0 (zero)’ The ‘0’th word. For many applications, this is the command word. d47255 1 a47255 1 ‘N’ d47258 1 a47258 1 ‘^’ d47261 1 a47261 1 ‘$’ d47264 2 a47265 2 ‘%’ The first word matched by the most recent ‘?STRING?’ search, if the d47268 2 a47269 2 ‘X-Y’ A range of words; ‘-Y’ abbreviates ‘0-Y’. d47271 3 a47273 3 ‘*’ All of the words, except the ‘0’th. This is a synonym for ‘1-$’. It is not an error to use ‘*’ if there is just one word in the d47276 2 a47277 2 ‘X*’ Abbreviates ‘X-$’ d47279 2 a47280 2 ‘X-’ Abbreviates ‘X-$’ like ‘X*’, but omits the last word. If ‘x’ is d47293 1 a47293 1 more of the following modifiers, each preceded by a ‘:’. These modify, d47296 1 a47296 1 ‘h’ d47299 1 a47299 1 ‘t’ d47302 2 a47303 2 ‘r’ Remove a trailing suffix of the form ‘.SUFFIX’, leaving the d47306 1 a47306 1 ‘e’ d47309 1 a47309 1 ‘p’ d47312 1 a47312 1 ‘s/OLD/NEW/’ d47314 1 a47314 1 Any character may be used as the delimiter in place of ‘/’. The d47316 2 a47317 2 ‘&’ appears in NEW, it is replaced by OLD. A single backslash will quote the ‘&’. If OLD is null, it is set to the last OLD d47319 1 a47319 1 the last STRING in a !?STRING‘[?]’ search. If NEW is is null, each d47323 1 a47323 1 ‘&’ d47326 2 a47327 2 ‘g’ ‘a’ d47329 1 a47329 1 conjunction with ‘s’, as in ‘gs/OLD/NEW/’, or with ‘&’. d47331 2 a47332 2 ‘G’ Apply the following ‘s’ or ‘&’ modifier once to each word in the d47343 1 a47343 1 ‘Fred Fish’ d47349 1 a47349 1 ‘Michael Snyder’ d47365 1 a47365 1 for printing with PostScript or Ghostscript, in the ‘gdb’ subdirectory d47368 1 a47368 1 immediately with ‘refcard.ps’. d47375 1 a47375 1 The GDB reference card is designed to print in “landscape” mode on US d47385 1 a47385 1 and TeX (or ‘texi2roff’) to typeset the printed version. d47388 3 a47390 3 this manual in the ‘gdb’ subdirectory. The main Info file is ‘gdb-15.1/gdb/gdb.info’, and it refers to subordinate files matching ‘gdb.info*’ in the same directory. If necessary, you can print out d47392 1 a47392 1 using the ‘info’ subsystem in GNU Emacs or the standalone ‘info’ d47396 1 a47396 1 Info formatting programs, such as ‘texinfo-format-buffer’ or ‘makeinfo’. d47398 2 a47399 2 If you have ‘makeinfo’ installed, and are in the top level GDB source directory (‘gdb-15.1’, in the case of version 15.1), you can make the d47406 1 a47406 1 a program to print its DVI output files, and ‘texinfo.tex’, the Texinfo d47413 3 a47415 3 use depends on your system; ‘lpr -d’ is common; another (for PostScript devices) is ‘dvips’. The DVI print command may require a file name without any extension or a ‘.dvi’ extension. d47417 1 a47417 1 TeX also requires a macro definitions file called ‘texinfo.tex’. d47420 2 a47421 2 ‘texinfo.tex’ is distributed with GDB and is located in the ‘gdb-VERSION-NUMBER/texinfo’ directory. d47424 2 a47425 2 and print this manual. First switch to the ‘gdb’ subdirectory of the main source directory (for example, to ‘gdb-15.1/gdb’) and type: d47429 1 a47429 1 Then give ‘gdb.dvi’ to your DVI printing program. d47433 1 a47433 1 (1) In ‘gdb-15.1/gdb/refcard.ps’ of the version 15.1 release. d47444 1 a47444 1 * Running Configure:: Invoking the GDB ‘configure’ script d47468 1 a47468 1 program. Other variants of ‘make’ will not work. d47472 1 a47472 1 ‘configure’ script searches for each of these libraries in several d47474 1 a47474 1 place, you can use either the ‘--with-LIB’ ‘configure’ option to d47476 2 a47477 2 ‘---with-LIBRARY-include’ (to specify the location of its header files) and ‘--with-LIBRARY-lib’ (to specify the location of its d47479 1 a47479 1 ‘--with-gmp’, ‘--with-gmp-include’, and ‘--with-gmp-lib’. *Note d47502 1 a47502 1 ‘configure’ script to specify their installation directories if they are d47504 2 a47505 2 ‘--with-PACKAGE’ to force GDB to be compiled with the named PACKAGE, and ‘--without-PACKAGE’ to disable building with it even if it is available. d47507 1 a47507 1 ‘configure’. d47512 1 a47512 1 . Use the ‘--with-python=DIR’ d47520 1 a47520 1 ‘--with-guile=GUILE-VERSION’ to specify the Guile version to d47527 3 a47529 3 • Remote protocol memory maps (*note Memory Map Format::) • Target descriptions (*note Target Descriptions::) • Remote shared library lists (*Note Library List Format::, or d47531 3 a47533 3 • MS-Windows shared libraries (*note Shared Libraries::) • Traceframe info (*note Traceframe Info Format::) • Branch trace (*note Branch Trace Format::, *note Branch Trace d47537 1 a47537 1 . Use the ‘--with-libexpat-prefix’ d47542 1 a47542 1 require a functioning ‘iconv’ implementation. If you are on a GNU d47544 2 a47545 2 systems also provide a working ‘iconv’. Use the option ‘--with-iconv-bin’ to specify where to find the ‘iconv’ program. d47547 1 a47547 1 On systems without ‘iconv’, you can install the GNU Libiconv d47550 1 a47550 1 provide it. Use the ‘--with-libiconv-prefix’ option to ‘configure’ d47553 2 a47554 2 Alternatively, GDB's top-level ‘configure’ and ‘Makefile’ will arrange to build Libiconv if a directory named ‘libiconv’ appears d47556 1 a47556 1 and if the operating system does not provide a suitable ‘iconv’ d47561 1 a47561 1 source code to ‘libiconv’. d47568 1 a47568 1 ‘--with-liblzma-prefix’ option to specify its non-standard d47572 2 a47573 2 GDB will use the ‘zlib’ library, if available, to read compressed debug sections. Some linkers, such as GNU ‘gold’, are capable of d47575 1 a47575 1 compiled with ‘zlib’, it will be able to read the debug information d47578 1 a47578 1 The ‘zlib’ library is likely included with your operating system d47585 1 a47585 1 C.2 Invoking the GDB ‘configure’ Script d47588 3 a47590 3 GDB comes with a ‘configure’ script that automates the process of preparing GDB for installation; you can then use ‘make’ to build the ‘gdb’ program. d47594 1 a47594 1 version number to ‘gdb’. d47596 1 a47596 1 For example, the GDB version 15.1 distribution is in the ‘gdb-15.1’ d47599 1 a47599 1 ‘gdb-15.1/configure (and supporting files)’ d47602 1 a47602 1 ‘gdb-15.1/gdb’ d47605 1 a47605 1 ‘gdb-15.1/bfd’ d47608 1 a47608 1 ‘gdb-15.1/include’ d47611 2 a47612 2 ‘gdb-15.1/libiberty’ source for the ‘-liberty’ free software library d47614 1 a47614 1 ‘gdb-15.1/opcodes’ d47617 1 a47617 1 ‘gdb-15.1/readline’ d47622 3 a47624 3 The simplest way to configure and build GDB is to run ‘configure’ from the ‘gdb-VERSION-NUMBER’ source directory, which in this example is the ‘gdb-15.1’ directory. d47626 2 a47627 2 First switch to the ‘gdb-VERSION-NUMBER’ source directory if you are not already in it; then run ‘configure’. Pass the identifier for the d47636 2 a47637 2 Running ‘configure’ and then running ‘make’ builds the included supporting libraries, then ‘gdb’ itself. The configured source files, d47640 1 a47640 1 ‘configure’ is a Bourne-shell (‘/bin/sh’) script; if your system does d47642 1 a47642 1 need to run ‘sh’ on it explicitly: d47646 2 a47647 2 You should run the ‘configure’ script from the top directory in the source tree, the ‘gdb-VERSION-NUMBER’ directory. If you run ‘configure’ d47650 3 a47652 3 run the first ‘configure’ from the ‘gdb’ subdirectory of the ‘gdb-VERSION-NUMBER’ directory, you will omit the configuration of ‘bfd’, ‘readline’, and other sibling directories of the ‘gdb’ d47654 1 a47654 1 such as ‘bfd/bfd.h’. d47656 3 a47658 3 You can install ‘GDB’ anywhere. The best way to do this is to pass the ‘--prefix’ option to ‘configure’, and then install it with ‘make install’. d47667 2 a47668 2 need a different ‘gdb’ compiled for each combination of host and target. ‘configure’ is designed to make this easy by allowing you to generate d47670 9 a47678 9 directory. If your ‘make’ program handles the ‘VPATH’ feature (GNU ‘make’ does), running ‘make’ in each of these directories builds the ‘gdb’ program specified there. To build ‘gdb’ in a separate directory, run ‘configure’ with the ‘--srcdir’ option to specify where to find the source. (You also need to specify a path to find ‘configure’ itself from your working directory. If the path to ‘configure’ would be the same as the argument to ‘--srcdir’, you can leave out the ‘--srcdir’ option; it is assumed.) d47689 1 a47689 1 When ‘configure’ builds a configuration using a remote source d47692 2 a47693 2 the example, you'd find the Sun 4 library ‘libiberty.a’ in the directory ‘gdb-sun4/libiberty’, and GDB itself in ‘gdb-sun4/gdb’. d47695 3 a47697 3 Make sure that your path to the ‘configure’ script has just one instance of ‘gdb’ in it. If your path to ‘configure’ looks like ‘../gdb-15.1/gdb/configure’, you are configuring only one subdirectory d47699 1 a47699 1 include files such as ‘bfd/bfd.h’. d47703 3 a47705 3 one machine--the “host”--while debugging programs that run on another machine--the “target”). You specify a cross-debugging target by giving the ‘--target=TARGET’ option to ‘configure’. d47707 1 a47707 1 When you run ‘make’ to build a program or library, you must run it in d47709 1 a47709 1 ‘configure’ (or one of its subdirectories). d47711 4 a47714 4 The ‘Makefile’ that ‘configure’ generates in each source directory also runs recursively. If you type ‘make’ in a source directory such as ‘gdb-15.1’ (or in a separate configured directory configured with ‘--srcdir=DIRNAME/gdb-15.1’), you will build all the required libraries, d47718 1 a47718 1 directories, you can run ‘make’ on them in parallel (for example, if d47728 1 a47728 1 The specifications used for hosts and targets in the ‘configure’ script d47735 3 a47737 3 For example, you can use the alias ‘sun4’ as a HOST argument, or as the value for TARGET in a ‘--target=TARGET’ option. The equivalent full name is ‘sparc-sun-sunos4’. d47739 1 a47739 1 The ‘configure’ script accompanying GDB does not provide any query d47741 1 a47741 1 ‘configure’ calls the Bourne shell script ‘config.sub’ to map d47758 2 a47759 2 ‘config.sub’ is also distributed in the GDB source directory (‘gdb-15.1’, for version 15.1). d47764 1 a47764 1 C.5 ‘configure’ Options d47767 2 a47768 2 Here is a summary of the ‘configure’ options and arguments that are most often useful for building GDB. ‘configure’ also has several other d47770 1 a47770 1 for a full explanation of ‘configure’. d47778 2 a47779 2 You may introduce options with a single ‘-’ rather than ‘--’ if you prefer; but you may abbreviate option names if you use ‘--’. d47781 2 a47782 2 ‘--help’ Display a quick summary of how to invoke ‘configure’. d47784 1 a47784 1 ‘--prefix=DIR’ d47786 1 a47786 1 ‘DIR’. d47788 2 a47789 2 ‘--exec-prefix=DIR’ Configure the source to install programs under directory ‘DIR’. d47791 1 a47791 1 ‘--srcdir=DIRNAME’ d47795 1 a47795 1 separate directories. ‘configure’ writes configuration-specific d47797 1 a47797 1 source in the directory DIRNAME. ‘configure’ creates directories d47801 1 a47801 1 ‘--target=TARGET’ d47807 1 a47807 1 targets. Also see the ‘--enable-targets’ option, below. d47813 2 a47814 2 ‘--enable-targets=[TARGET]...’ ‘--enable-targets=all’ d47816 1 a47816 1 list of targets. The special value ‘all’ configures GDB for d47819 1 a47819 1 ‘--with-gdb-datadir=PATH’ d47821 2 a47822 2 certain supporting files or scripts. This defaults to the ‘gdb’ subdirectory of ‘datadir’ (which can be set using ‘--datadir’). d47824 1 a47824 1 ‘--with-relocated-sources=DIR’ d47828 2 a47829 2 configured prefix, the one mentioned in the ‘--prefix’ or ‘--exec-prefix’ options to configure. This option is useful if GDB d47832 1 a47832 1 ‘--enable-64-bit-bfd’ d47835 1 a47835 1 ‘--disable-gdbmi’ d47838 1 a47838 1 ‘--enable-tui’ d47842 1 a47842 1 ‘--with-curses’ d47846 2 a47847 2 ‘--with-debuginfod’ Build GDB with ‘libdebuginfod’, the ‘debuginfod’ client library. d47849 2 a47850 2 ‘debuginfod’ servers using build IDs associated with any missing files. Enabled by default if ‘libdebuginfod’ is installed and d47852 1 a47852 1 ‘debuginfod’ see *note Debuginfod::. d47854 1 a47854 1 ‘--with-libunwind-ia64’ d47859 1 a47859 1 ‘--with-system-readline’ d47864 1 a47864 1 ‘--with-system-zlib’ d47868 1 a47868 1 ‘--with-expat’ d47878 1 a47878 1 ‘--with-libiconv-prefix[=DIR]’ d47881 2 a47882 2 ‘iconv’ that is built in to the C library is sufficient. If your host does not have a working ‘iconv’, you can get the latest d47888 1 a47888 1 ‘--with-lzma’ d47896 1 a47896 1 ‘--with-python[=PYTHON]’ d47907 1 a47907 1 ‘--with-guile[=GUILE]’ d47912 2 a47913 2 can be a version number, which will cause ‘configure’ to try to use that version of Guile; or the file name of a ‘pkg-config’ d47917 1 a47917 1 ‘--without-included-regex’ d47922 1 a47922 1 ‘--with-sysroot=DIR’ d47924 4 a47927 4 file names begin with ‘/lib’' or ‘/usr/lib'’. (The value of DIR can be modified at run time by using the ‘set sysroot’ command.) If DIR is under the GDB configured prefix (set with ‘--prefix’ or ‘--exec-prefix options’, the default system root will be d47931 1 a47931 1 ‘--with-system-gdbinit=FILE’ d47938 1 a47938 1 ‘--with-system-gdbinit-dir=DIRECTORY’ d47945 1 a47945 1 ‘--enable-build-warnings’ d47951 2 a47952 2 ‘--enable-werror’ Treat compiler warnings as errors. It adds the ‘-Werror’ flag to d47956 1 a47956 1 ‘--enable-ubsan’ d47958 2 a47959 2 default, but passing ‘--enable-ubsan=yes’ or ‘--enable-ubsan=auto’ to ‘configure’ will enable it. The undefined behavior sanitizer d47977 1 a47977 1 ‘--with-system-gdbinit=FILE’ d47980 1 a47980 1 ‘--with-system-gdbinit-dir=DIRECTORY’ d47984 1 a47984 1 If GDB has been configured with the option ‘--prefix=$prefix’, they d47987 6 a47992 6 • If the default location of this init file/directory contains ‘$prefix’, it will be subject to relocation. Suppose that the configure options are ‘--prefix=$prefix --with-system-gdbinit=$prefix/etc/gdbinit’; if GDB is moved from ‘$prefix’ to ‘$install’, the system init file is looked for as ‘$install/etc/gdbinit’ instead of ‘$prefix/etc/gdbinit’. d47994 1 a47994 1 • By contrast, if the default location does not contain the prefix, d47996 2 a47997 2 ‘--prefix=/usr/local --with-system-gdbinit=/usr/share/gdb/gdbinit’, then GDB will always look for ‘/usr/share/gdb/gdbinit’, wherever d48001 2 a48002 2 the ‘--with-system-gdbinit’ option at configure time) is in the data-directory (as specified by ‘--with-gdb-datadir’ at configure time) d48004 1 a48004 1 init file in the directory specified by the ‘--data-directory’ d48007 1 a48007 1 GDB has started with the ‘set data-directory’ command, the file will not d48011 1 a48011 1 ‘--with-system-gdbinit-dir’. d48015 1 a48015 1 interpreted as regular GDB commands, the files needs to have a ‘.gdb’ d48028 2 a48029 2 The ‘system-gdbinit’ directory, located inside the data-directory (as specified by ‘--with-gdb-datadir’ at configure time) contains a number d48032 1 a48032 1 with ‘--with-system-gdbinit’. Otherwise, any user should be able to d48037 1 a48037 1 • ‘elinos.py’ This script is useful when debugging a program on an d48041 1 a48041 1 ‘solib-absolute-prefix’ and ‘solib-search-path’ variables d48044 2 a48045 2 • ‘wrs-linux.py’ This script is useful when debugging a program on a target running Wind River Linux. It expects the ‘ENV_PREFIX’ to be d48059 2 a48060 2 ‘maint agent [-at LINESPEC,] EXPRESSION’ ‘maint agent-eval [-at LINESPEC,] EXPRESSION’ d48063 1 a48063 1 (*note Agent Expressions::). The ‘agent’ version produces an d48065 1 a48065 1 while ‘maint agent-eval’ produces an expression that evaluates d48067 2 a48068 2 ‘globa + globb’ will include bytecodes to record four bytes of memory at each of the addresses of ‘globa’ and ‘globb’, while d48070 1 a48070 1 expression will do the addition and return the sum. If ‘-at’ is d48075 1 a48075 1 ‘maint agent-printf FORMAT,EXPR,...’ d48081 2 a48082 2 ‘maint info breakpoints’ Using the same format as ‘info breakpoints’, display both the d48088 1 a48088 1 ‘breakpoint’ d48091 1 a48091 1 ‘watchpoint’ d48094 1 a48094 1 ‘longjmp’ d48096 1 a48096 1 ‘longjmp’ calls. d48098 2 a48099 2 ‘longjmp resume’ Internal breakpoint at the target of a ‘longjmp’. d48101 2 a48102 2 ‘until’ Temporary internal breakpoint used by the GDB ‘until’ command. d48104 2 a48105 2 ‘finish’ Temporary internal breakpoint used by the GDB ‘finish’ d48108 1 a48108 1 ‘shlib events’ d48111 1 a48111 1 ‘maint info btrace’ d48114 1 a48114 1 ‘maint btrace packet-history’ d48116 1 a48116 1 execution history for the ‘record btrace’ command. Both the d48120 1 a48120 1 ‘bts’ d48128 2 a48129 2 Lowest ‘PC’ Highest ‘PC’ d48131 1 a48131 1 ‘pt’ d48143 3 a48145 3 ‘maint btrace clear-packet-history’ Discards the cached packet history printed by the ‘maint btrace packet-history’ command. The history will be computed again when d48148 1 a48148 1 ‘maint btrace clear’ d48156 2 a48157 2 ‘maint set btrace pt skip-pad’ ‘maint show btrace pt skip-pad’ d48161 1 a48161 1 ‘maint info jit’ d48165 2 a48166 2 ‘maint info python-disassemblers’ This command is defined within the ‘gdb.disassembler’ Python module d48171 1 a48171 1 ‘maint info linux-lwps’ d48180 1 a48180 1 listed last against the ‘GLOBAL’ architecture. d48186 1 a48186 1 are registered, initially the ‘i386’ disassembler matches the d48188 1 a48188 1 ‘GLOBAL’ disassembler matches. d48204 3 a48206 3 ‘set displaced-stepping’ ‘show displaced-stepping’ Control whether or not GDB will do “displaced stepping” if the d48213 1 a48213 1 ‘set displaced-stepping on’ d48217 1 a48217 1 ‘set displaced-stepping off’ d48221 1 a48221 1 ‘set displaced-stepping auto’ d48226 1 a48226 1 ‘maint check-psymtabs’ d48231 1 a48231 1 ‘maint check-symtabs’ d48234 1 a48234 1 ‘maint expand-symtabs [REGEXP]’ d48238 2 a48239 2 ‘maint set catch-demangler-crashes [on|off]’ ‘maint show catch-demangler-crashes’ d48246 1 a48246 1 ‘maint cplus first_component NAME’ d48249 1 a48249 1 ‘maint cplus namespace’ d48252 2 a48253 2 ‘maint deprecate COMMAND [REPLACEMENT]’ ‘maint undeprecate COMMAND’ d48260 1 a48260 1 ‘maint dump-me’ d48263 1 a48263 1 with the ‘SIGQUIT’ signal. d48265 3 a48267 3 ‘maint internal-error [MESSAGE-TEXT]’ ‘maint internal-warning [MESSAGE-TEXT]’ ‘maint demangler-warning [MESSAGE-TEXT]’ d48269 2 a48270 2 Cause GDB to call the internal function ‘internal_error’, ‘internal_warning’ or ‘demangler_warning’ and hence behave as d48273 2 a48274 2 opportunity to either quit GDB or (for ‘internal_error’ and ‘internal_warning’) create a core file of the current GDB session. d48279 1 a48279 1 Here's an example of using ‘internal-error’: d48289 3 a48291 3 ‘maint set debuginfod download-sections’ ‘maint set debuginfod download-sections [on|off]’ ‘maint show debuginfod download-sections’ d48293 1 a48293 1 sections from ‘debuginfod’. If disabled, only whole debug info d48297 6 a48302 6 ‘maint set internal-error ACTION [ask|yes|no]’ ‘maint show internal-error ACTION’ ‘maint set internal-warning ACTION [ask|yes|no]’ ‘maint show internal-warning ACTION’ ‘maint set demangler-warning ACTION [ask|yes|no]’ ‘maint show demangler-warning ACTION’ d48309 1 a48309 1 ‘quit’ d48313 1 a48313 1 ‘corefile’ d48316 2 a48317 2 do. Note that there is no ‘corefile’ option for ‘demangler-warning’: demangler warnings always create a core d48320 4 a48323 4 ‘maint set internal-error backtrace [on|off]’ ‘maint show internal-error backtrace’ ‘maint set internal-warning backtrace [on|off]’ ‘maint show internal-warning backtrace’ d48326 2 a48327 2 stream. This is ‘on’ by default for ‘internal-error’ and ‘off’ by default for ‘internal-warning’. d48329 1 a48329 1 ‘maint packet TEXT’ d48332 2 a48333 2 response packet. GDB supplies the initial ‘$’ character, the terminating ‘#’ character, and the checksum. d48336 1 a48336 1 hex, e.g. ‘\x00’, ‘\x01’, etc. d48338 1 a48338 1 ‘maint print architecture [FILE]’ d48342 1 a48342 1 ‘maint print c-tdesc [-single-feature] [FILE]’ d48352 1 a48352 1 When the optional flag ‘-single-feature’ is provided then the d48357 1 a48357 1 ‘maint print xml-tdesc [FILE]’ d48365 1 a48365 1 ‘maint check xml-descriptions DIR’ d48369 1 a48369 1 ‘maint check libthread-db’ d48371 1 a48371 1 library. This exercises all ‘libthread_db’ functionality used by d48373 1 a48373 1 ‘proc_service’ functions provided by GDB that ‘libthread_db’ uses. d48377 1 a48377 1 ‘maint print core-file-backed-mappings’ d48380 1 a48380 1 similar to the mappings displayed by the ‘info proc mappings’ d48383 1 a48383 1 ‘maint print dummy-frames’ d48399 2 a48400 2 ‘maint print frame-id’ ‘maint print frame-id LEVEL’ d48405 1 a48405 1 ‘backtrace’ output. d48412 5 a48416 5 ‘maint print registers [FILE]’ ‘maint print raw-registers [FILE]’ ‘maint print cooked-registers [FILE]’ ‘maint print register-groups [FILE]’ ‘maint print remote-registers [FILE]’ d48419 2 a48420 2 The command ‘maint print raw-registers’ includes the contents of the raw register cache; the command ‘maint print cooked-registers’ d48423 3 a48425 3 command ‘maint print register-groups’ includes the groups that each register is a member of; and the command ‘maint print remote-registers’ includes the remote target's register numbers and d48431 1 a48431 1 ‘maint print reggroups [FILE]’ d48447 2 a48448 2 ‘maint flush register-cache’ ‘flushregs’ d48451 2 a48452 2 to register fetching, or frame unwinding. The command ‘flushregs’ is deprecated in favor of ‘maint flush register-cache’. d48454 1 a48454 1 ‘maint flush source-cache’ d48465 1 a48465 1 ‘maint print objfiles [REGEXP]’ d48471 2 a48472 2 ‘maint print user-registers’ List all currently available “user registers”. User registers d48474 2 a48475 2 They include the four "standard" registers ‘$fp’, ‘$pc’, ‘$sp’, and ‘$ps’. *Note standard registers::. User registers can be used in d48477 2 a48478 2 only the latter are listed by the ‘info registers’ and ‘maint print registers’ commands. d48480 2 a48481 2 ‘maint print section-scripts [REGEXP]’ Print a dump of scripts specified in the ‘.debug_gdb_section’ d48487 1 a48487 1 ‘maint print statistics’ d48489 1 a48489 1 data about that object file followed by the byte cache (“bcache”) d48500 3 a48502 3 ‘maint print target-stack’ A “target” is an interface between the debugger and a particular kind of file or process. Targets can be stacked in “strata”, so d48509 1 a48509 1 pushed on the “target stack”, starting from the top layer down to d48512 1 a48512 1 ‘maint print type EXPR’ d48519 2 a48520 2 ‘maint print record-instruction’ ‘maint print record-instruction N’ d48527 1 a48527 1 ‘maint selftest [-verbose] [FILTER]’ d48531 1 a48531 1 ran. If ‘-verbose’ is passed, the self tests can be more verbose. d48533 2 a48534 2 ‘maint set selftest verbose’ ‘maint show selftest verbose’ d48537 1 a48537 1 ‘maint info selftests’ d48540 3 a48542 3 ‘maint set dwarf always-disassemble’ ‘maint show dwarf always-disassemble’ Control the behavior of ‘info address’ when using DWARF debugging d48545 2 a48546 2 The default is ‘off’, which means that GDB should try to describe a variable's location in an easily readable format. When ‘on’, GDB d48561 2 a48562 2 ‘maint set dwarf max-cache-age’ ‘maint show dwarf max-cache-age’ d48566 1 a48566 1 those produced by the GCC option ‘-feliminate-dwarf2-dups’, the d48575 2 a48576 2 ‘maint set dwarf synchronous’ ‘maint show dwarf synchronous’ d48592 2 a48593 2 ‘maint set dwarf unwinders’ ‘maint show dwarf unwinders’ d48615 1 a48615 1 ‘maint info frame-unwinders’ d48619 2 a48620 2 ‘maint set worker-threads’ ‘maint show worker-threads’ d48626 1 a48626 1 ‘unlimited’, which lets GDB choose a reasonable number. Note that d48630 2 a48631 2 ‘maint set profile’ ‘maint show profile’ d48634 1 a48634 1 Profiling will be disabled until you use the ‘maint set profile’ d48639 2 a48640 2 profiling log file (often called ‘gmon.out’). If you have a record of important profiling data in a ‘gmon.out’ file, be sure to move d48643 2 a48644 2 Configuring with ‘--enable-profiling’ arranges for GDB to be compiled with the ‘-pg’ compiler option. d48646 2 a48647 2 ‘maint set show-debug-regs’ ‘maint show show-debug-regs’ d48649 1 a48649 1 registers. Use ‘on’ to enable, ‘off’ to disable. If enabled, the d48654 2 a48655 2 ‘maint set show-all-tib’ ‘maint show show-all-tib’ d48657 2 a48658 2 starting at thread local base, when using the ‘info w32 thread-information-block’ command. d48660 2 a48661 2 ‘maint set target-async’ ‘maint show target-async’ d48668 2 a48669 2 ‘maint set target-non-stop’ ‘maint show target-non-stop’ d48672 2 a48673 2 even if ‘set non-stop’ is ‘off’ (*note Non-Stop Mode::). The default is ‘auto’, meaning non-stop mode is enabled if supported by d48676 1 a48676 1 ‘maint set target-non-stop auto’ d48680 1 a48680 1 ‘maint set target-non-stop on’ d48684 1 a48684 1 ‘maint set target-non-stop off’ d48688 2 a48689 2 ‘maint set tui-resize-message’ ‘maint show tui-resize-message’ d48691 2 a48692 2 resized when in TUI mode. The default is ‘off’, which means that GDB is silent during resizes. When ‘on’, GDB will display a d48699 2 a48700 2 ‘maint set tui-left-margin-verbose’ ‘maint show tui-left-margin-verbose’ d48702 2 a48703 2 windows uses ‘_’ and ‘0’ at locations where otherwise there would be a space. The default is ‘off’, which means spaces are used. d48708 2 a48709 2 ‘maint set per-command’ ‘maint show per-command’ d48714 2 a48715 2 ‘maint set per-command space [on|off]’ ‘maint show per-command space’ d48719 1 a48719 1 can also be requested by invoking GDB with the ‘--statistics’ d48722 2 a48723 2 ‘maint set per-command time [on|off]’ ‘maint show per-command time’ d48734 1 a48734 1 also be requested by invoking GDB with the ‘--statistics’ d48737 2 a48738 2 ‘maint set per-command symtab [on|off]’ ‘maint show per-command symtab’ d48747 2 a48748 2 ‘maint set check-libthread-db [on|off]’ ‘maint show check-libthread-db’ d48756 2 a48757 2 ‘maint set gnu-source-highlight enabled [on|off]’ ‘maint show gnu-source-highlight enabled’ d48760 1 a48760 1 will be ‘on’ by default if the GNU Source Highlight library is d48762 2 a48763 2 then this will be ‘off’ by default, and attempting to change this value to ‘on’ will give an error. d48773 2 a48774 2 ‘maint set libopcodes-styling enabled [on|off]’ ‘maint show libopcodes-styling enabled’ d48776 1 a48776 1 (‘libopcodes’) to style disassembler output (*note Output d48780 1 a48780 1 When this option is ‘off’ the builtin disassembler will not be used d48784 1 a48784 1 Trying to set this option ‘on’ for an architecture that the builtin d48788 1 a48788 1 This option is ‘on’ by default for supported architectures. d48794 1 a48794 1 ‘maint info screen’ d48798 2 a48799 2 ‘maint space VALUE’ An alias for ‘maint set per-command space’. A non-zero value d48802 2 a48803 2 ‘maint time VALUE’ An alias for ‘maint set per-command time’. A non-zero value d48806 1 a48806 1 ‘maint translate-address [SECTION] ADDR’ d48810 2 a48811 2 location to the specified address. This is similar to the ‘info address’ command (*note Symbols::), except that this command also d48819 3 a48821 3 ‘maint test-options require-delimiter’ ‘maint test-options unknown-is-error’ ‘maint test-options unknown-is-operand’ d48823 1 a48823 1 options framework. The ‘require-delimiter’ variant requires a d48825 3 a48827 3 ‘unknown-is-error’ and ‘unknown-is-operand’ do not. The ‘unknown-is-error’ variant throws an error on unknown option, while ‘unknown-is-operand’ treats unknown options as the start of the d48830 2 a48831 2 internal result of completion in a variable exposed by the ‘maint show test-options-completion-result’ command. d48833 2 a48834 2 ‘maint show test-options-completion-result’ Shows the result of completing the ‘maint test-options’ d48838 2 a48839 2 ‘maint set test-settings KIND’ ‘maint show test-settings KIND’ d48844 3 a48846 3 ‘maint set backtrace-on-fatal-signal [on|off]’ ‘maint show backtrace-on-fatal-signal’ When this setting is ‘on’, if GDB itself terminates with a fatal d48854 1 a48854 1 ‘off’ by default, and attempting to turn this feature on will give d48858 1 a48858 1 is ‘on’ by default. d48860 1 a48860 1 ‘maint wait-for-index-cache’ d48865 3 a48867 3 ‘maint with SETTING [VALUE] [-- COMMAND]’ Like the ‘with’ command, but works with ‘maintenance set’ variables. This is used by the testsuite to exercise the ‘with’ d48870 2 a48871 2 ‘maint ignore-probes [-V|-VERBOSE] [PROVIDER [NAME [OBJFILE]]]’ ‘maint ignore-probes -RESET’ d48873 1 a48873 1 OBJFILE arguments are as in ‘enable probes’ and ‘disable probes’ d48876 1 a48876 1 Here's an example of using ‘maint ignore-probes’: d48891 1 a48891 1 ‘set watchdog NSEC’ d48896 1 a48896 1 ‘show watchdog’ d48940 1 a48940 1 In the examples below, ‘->’ and ‘<-’ are used to indicate transmitted d48945 2 a48946 2 A PACKET is introduced with the character ‘$’, the actual PACKET-DATA, and the terminating character ‘#’ followed by a two-digit CHECKSUM: d48951 1 a48951 1 characters between the leading ‘$’ and the trailing ‘#’ (an eight bit d48964 2 a48965 2 first response expected is an acknowledgment: either ‘+’ (to indicate the package was received correctly) or ‘-’ (to request retransmission): d48970 1 a48970 1 The ‘+’/‘-’ acknowledgments can be disabled once a connection is d48982 1 a48982 1 of ‘#’ and ‘$’ (see ‘X’ packet for additional exceptions). d48984 1 a48984 1 Fields within the packet should be separated using ‘,’ ‘;’ or ‘:’. d48988 1 a48988 1 Implementors should note that prior to GDB 5.0, the character ‘:’ d48998 1 a48998 1 The binary data representation uses ‘7d’ (ASCII ‘}’) as an escape d49000 3 a49002 3 followed by the original character XORed with ‘0x20’. For example, the byte ‘0x7d’ would be transmitted as the two bytes ‘0x7d 0x5d’. The bytes ‘0x23’ (ASCII ‘#’), ‘0x24’ (ASCII ‘$’), and ‘0x7d’ (ASCII ‘}’) d49004 1 a49004 1 ‘0x2a’ (ASCII ‘*’), so that it is not interpreted as the start of a d49009 1 a49009 1 repeated character, followed by a ‘*’ and a repeat count. The repeat d49011 1 a49011 1 value of N is sent as ‘N+29’. For a repeat count greater or equal to 3, d49014 8 a49021 8 win for counts 3 or more.) Thus, for example, ‘0* ’ is a run-length encoding of "0000": the space character after ‘*’ means repeat the leading ‘0’ ‘32 - 29 = 3’ more times. The printable characters ‘#’ and ‘$’ or with a numeric value greater than 126 must not be used. Runs of six repeats (‘#’) or seven repeats (‘$’) can be expanded using a repeat count of only five (‘"’). For example, ‘00000000’ can be encoded as ‘0*"00’. d49030 2 a49031 2 spaces to separate its components. For example, a template like ‘foo BAR BAZ’ describes a packet beginning with the three ASCII bytes ‘foo’, d49033 1 a49033 1 space character between the ‘foo’ and the BAR, or between the BAR and d49037 2 a49038 2 example, a template like ‘c [ADDR]’ describes a packet beginning with the single ASCII character ‘c’, possibly followed by an ADDR. d49040 4 a49043 4 At a minimum, a stub is required to support the ‘?’ command to tell GDB the reason for halting, ‘g’ and ‘G’ commands for register access, and the ‘m’ and ‘M’ commands for memory access. Stubs that only control single-threaded targets can implement run control with the ‘c’ d49045 2 a49046 2 hardware-assisted single-stepping, the ‘s’ (step) command. Stubs that support multi-threading targets should support the ‘vCont’ command. All d49060 1 a49060 1 An empty response (raw character sequence ‘$#00’) means the COMMAND d49065 1 a49065 1 ‘E XX’ d49071 1 a49071 1 ‘E.ERRTEXT’ d49090 3 a49092 3 For example, a template like ‘foo BAR BAZ’ describes a packet beginning with the three ASCII bytes ‘foo’, followed by a BAR, followed directly by a BAZ. GDB does not transmit a space character between the ‘foo’ and d49098 1 a49098 1 also be a literal ‘-1’ to indicate all threads, or ‘0’ to pick any d49103 1 a49103 1 process and thread ID fields, as ‘pPID.TID’. The PID (process) and TID d49106 3 a49108 3 string, literal ‘-1’ to indicate all processes or threads (respectively), or ‘0’ to indicate an arbitrary process or thread. Specifying just a process, as ‘pPID’, is equivalent to ‘pPID.-1’. It is d49110 1 a49110 1 ‘p-1.TID’. Note that the ‘p’ prefix is _not_ used for those packets and d49115 2 a49116 2 GDB and the stub report support for the ‘multiprocess’ feature using ‘qSupported’. *Note multiprocess extensions::, for more information. d49123 1 a49123 1 ‘!’ d49125 1 a49125 1 persistent. The ‘R’ packet is used to restart the program being d49129 1 a49129 1 ‘OK’ d49132 1 a49132 1 ‘?’ d49140 2 a49141 2 ‘A ARGLEN,ARGNUM,ARG,...’ Initialized ‘argv[]’ array passed into program. ARGLEN specifies d49143 1 a49143 1 ‘gdbserver’ for more details. d49146 1 a49146 1 ‘OK’ d49149 1 a49149 1 ‘b BAUD’ d49164 2 a49165 2 ‘B ADDR,MODE’ Set (MODE is ‘S’) or clear (MODE is ‘C’) a breakpoint at ADDR. d49167 1 a49167 1 Don't use this packet. Use the ‘Z’ and ‘z’ packets instead (*note d49170 1 a49170 1 ‘bc’ d49176 1 a49176 1 ‘bs’ d49182 1 a49182 1 ‘c [ADDR]’ d49191 2 a49192 2 ‘C SIG[;ADDR]’ Continue with signal SIG (hex signal number). If ‘;ADDR’ is d49200 1 a49200 1 ‘d’ d49206 2 a49207 2 ‘D’ ‘D;PID’ d49210 1 a49210 1 the ‘detach’ command. d49218 1 a49218 1 ‘OK’ d49221 2 a49222 2 ‘F RC,EE,CF;XX’ A reply from GDB to an ‘F’ packet sent by the target. This is part d49226 1 a49226 1 ‘g’ d49230 1 a49230 1 ‘XX...’ d49234 1 a49234 1 the ‘g’ packet are determined by the target description (*note d49241 1 a49241 1 literal ‘x’'s in place of the register data digits, to d49261 1 a49261 1 ‘G XX...’ d49266 1 a49266 1 ‘OK’ d49269 3 a49271 3 ‘H OP THREAD-ID’ Set thread for subsequent operations (‘m’, ‘M’, ‘g’, ‘G’, et.al.). Depending on the operation to be performed, OP should be ‘c’ for d49273 1 a49273 1 supporting the ‘vCont’ command is a better option), and ‘g’ for d49278 1 a49278 1 ‘OK’ d49281 2 a49282 2 ‘i [ADDR[,NNN]]’ Step the remote target by a single clock cycle. If ‘,NNN’ is d49286 1 a49286 1 ‘I’ d49290 1 a49290 1 ‘k’ d49296 1 a49296 1 system. For that reason, the ‘k’ packet has no reply. d49305 1 a49305 1 to ‘k’, GDB does not consider the lack of packet acknowledgment to d49308 1 a49308 1 If connected using ‘target extended-remote’, and the target does d49313 1 a49313 1 ‘m ADDR,LENGTH’ d49325 1 a49325 1 ‘XX...’ d49331 1 a49331 1 Unlike most packets, this packet does not support ‘E.ERRTEXT’-style d49334 1 a49334 1 ‘M ADDR,LENGTH:XX...’ d49340 1 a49340 1 ‘OK’ d49344 1 a49344 1 ‘p N’ d49350 1 a49350 1 ‘XX...’ d49353 1 a49353 1 ‘P N...=R...’ d49359 1 a49359 1 ‘OK’ d49362 3 a49364 3 ‘q NAME PARAMS...’ ‘Q NAME PARAMS...’ General query (‘q’) and set (‘Q’). These packets are described d49367 1 a49367 1 ‘r’ d49370 1 a49370 1 Don't use this packet; use the ‘R’ packet instead. d49372 1 a49372 1 ‘R XX’ d49377 1 a49377 1 The ‘R’ packet has no reply. d49379 1 a49379 1 ‘s [ADDR]’ d49388 2 a49389 2 ‘S SIG[;ADDR]’ Step with signal. This is analogous to the ‘C’ packet, but d49398 1 a49398 1 ‘t ADDR:PP,MM’ d49403 1 a49403 1 ‘T THREAD-ID’ d49408 1 a49408 1 ‘OK’ d49411 3 a49413 3 ‘v’ Packets starting with ‘v’ are identified by a multi-letter name, up to the first ‘;’ or ‘?’ (or the end of the packet). d49415 1 a49415 1 ‘vAttach;PID’ d49426 1 a49426 1 ‘Any stop packet’ d49428 1 a49428 1 ‘OK’ d49431 1 a49431 1 ‘vCont[;ACTION[:THREAD-ID]]...’ d49439 1 a49439 1 specified to match all threads in a process by using the ‘pPID.-1’ d49445 1 a49445 1 ‘c’ d49447 1 a49447 1 ‘C SIG’ d49450 1 a49450 1 ‘s’ d49452 1 a49452 1 ‘S SIG’ d49455 1 a49455 1 ‘t’ d49457 1 a49457 1 ‘r START,END’ d49465 1 a49465 1 equivalent to the ‘s’ action. In other words, single-step d49474 2 a49475 2 The optional argument ADDR normally associated with the ‘c’, ‘C’, ‘s’, and ‘S’ packets is not supported in ‘vCont’. d49477 1 a49477 1 The ‘t’ action is only relevant in non-stop mode (*note Remote d49480 1 a49480 1 When a thread is stopped by means of a ‘t’ action, the d49482 1 a49482 1 stopped with signal ‘0’, regardless of whether the target uses some d49485 1 a49485 1 The server must ignore ‘c’, ‘C’, ‘s’, ‘S’, and ‘r’ actions for d49487 1 a49487 1 ignore ‘t’ actions for threads that are already stopped. d49491 1 a49491 1 ‘vStopped’ packet (*note Remote Non-Stop::). d49493 1 a49493 1 The stub must support ‘vCont’ if it reports support for d49498 2 a49499 2 ‘vCont?’ Request a list of actions supported by the ‘vCont’ packet. d49502 3 a49504 3 ‘vCont[;ACTION...]’ The ‘vCont’ packet is supported. Each ACTION is a supported command in the ‘vCont’ packet. d49506 1 a49506 1 ‘vCtrlC’ d49508 1 a49508 1 terminal. This is the equivalent to reacting to the ‘^C’ (‘\003’, d49515 1 a49515 1 ‘OK’ d49518 1 a49518 1 ‘vFile:OPERATION:PARAMETER...’ d49522 1 a49522 1 ‘vFlashErase:ADDR,LENGTH’ d49528 2 a49529 2 a ‘vFlashDone’ request after each group; the stub is allowed to delay erase operation until the ‘vFlashDone’ packet is received. d49532 1 a49532 1 ‘OK’ d49535 1 a49535 1 ‘vFlashWrite:ADDR:XX...’ d49537 1 a49537 1 passed in binary form using the same encoding as for the ‘X’ packet d49539 1 a49539 1 ‘vFlashWrite’ packets preceding a ‘vFlashDone’ packet must not d49541 2 a49542 2 ‘vFlashErase’ packets for higher addresses may already have been received; the ordering is guaranteed only between ‘vFlashWrite’ d49544 1 a49544 1 by a preceding ‘vFlashErase’ packet nor by some other d49548 1 a49548 1 ‘OK’ d49550 1 a49550 1 ‘E.memtype’ d49553 1 a49553 1 ‘vFlashDone’ d49556 1 a49556 1 ‘vFlashErase’ and ‘vFlashWrite’ packets until a ‘vFlashDone’ packet d49558 1 a49558 1 are unpredictable until the ‘vFlashDone’ request is completed. d49560 1 a49560 1 ‘vKill;PID’ d49563 1 a49563 1 in preference to ‘k’ when multiprocess protocol extensions are d49567 1 a49567 1 ‘OK’ d49570 9 a49578 9 ‘vMustReplyEmpty’ The correct reply to an unknown ‘v’ packet is to return the empty string, however, some older versions of ‘gdbserver’ would incorrectly return ‘OK’ for unknown ‘v’ packets. The ‘vMustReplyEmpty’ is used as a feature test to check how ‘gdbserver’ handles unknown packets, it is important that this packet be handled in the same way as other unknown ‘v’ packets. If this packet is handled differently to other unknown ‘v’ packets d49580 1 a49580 1 specifically around use of ‘vFile:setfs:’. d49582 1 a49582 1 ‘vRun;FILENAME[;ARGUMENT]...’ d49592 1 a49592 1 ‘Any stop packet’ d49595 1 a49595 1 ‘vStopped’ d49598 1 a49598 1 ‘X ADDR,LENGTH:XX...’ d49601 1 a49601 1 memory units LENGTH (*note addressable memory unit::); ‘XX...’ is d49605 1 a49605 1 ‘OK’ d49608 3 a49610 3 ‘z TYPE,ADDR,KIND’ ‘Z TYPE,ADDR,KIND’ Insert (‘Z’) or remove (‘z’) a TYPE breakpoint or watchpoint d49618 2 a49619 2 target shall support either both or neither of a given ‘ZTYPE...’ and ‘zTYPE...’ packet pair. To avoid potential problems with d49623 3 a49625 3 ‘z0,ADDR,KIND’ ‘Z0,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]’ Insert (‘Z0’) or remove (‘z0’) a software breakpoint at address d49635 1 a49635 1 architecture-specific value is being used, it should be ‘0’. KIND d49642 1 a49642 1 See also the ‘swbreak’ stop reason (*note swbreak stop reason::) d49649 1 a49649 1 ‘X LEN,EXPR’ d49661 1 a49661 1 ‘X LEN,EXPR’ d49671 1 a49671 1 ‘OK’ d49674 3 a49676 3 ‘z1,ADDR,KIND’ ‘Z1,ADDR,KIND[;COND_LIST...][;cmds:PERSIST,CMD_LIST...]’ Insert (‘Z1’) or remove (‘z1’) a hardware breakpoint at address d49681 1 a49681 1 COND_LIST, and CMD_LIST arguments have the same meaning as in ‘Z0’ d49688 1 a49688 1 ‘OK’ d49691 3 a49693 3 ‘z2,ADDR,KIND’ ‘Z2,ADDR,KIND’ Insert (‘Z2’) or remove (‘z2’) a write watchpoint at ADDR. The d49697 1 a49697 1 ‘OK’ d49700 3 a49702 3 ‘z3,ADDR,KIND’ ‘Z3,ADDR,KIND’ Insert (‘Z3’) or remove (‘z3’) a read watchpoint at ADDR. The d49706 1 a49706 1 ‘OK’ d49709 3 a49711 3 ‘z4,ADDR,KIND’ ‘Z4,ADDR,KIND’ Insert (‘Z4’) or remove (‘z4’) an access watchpoint at ADDR. The d49715 1 a49715 1 ‘OK’ d49724 5 a49728 5 The ‘C’, ‘c’, ‘S’, ‘s’, ‘vCont’, ‘vAttach’, ‘vRun’, ‘vStopped’, and ‘?’ packets can receive any of the below as a reply. Except for ‘?’ and ‘vStopped’, that reply is only returned when the target halts. In the below the exact meaning of “signal number” is defined by the header ‘include/gdb/signals.h’ in the GDB source code. d49730 2 a49731 2 In non-stop mode, the server will simply reply ‘OK’ to commands such as ‘vCont’; any stop will be the subject of a future notification. d49739 1 a49739 1 ‘S AA’ d49741 1 a49741 1 number). This is equivalent to a ‘T’ response with no N:R pairs. d49743 1 a49743 1 ‘T AA N1:R1;N2:R2;...’ d49745 2 a49746 2 number). This is equivalent to an ‘S’ response, except that the ‘N:R’ pairs can carry values of important registers and other d49749 1 a49749 1 Each ‘N:R’ pair is interpreted as follows: d49751 1 a49751 1 • If N is a hexadecimal number, it is a register number, and the d49756 1 a49756 1 • If N is ‘thread’, then R is the thread ID of the stopped d49759 1 a49759 1 • If N is ‘core’, then R is the hexadecimal number of the core d49762 1 a49762 1 • If N is a recognized “stop reason”, it describes a more d49764 1 a49764 1 stop reasons are listed below. The AA should be ‘05’, the d49767 1 a49767 1 • Otherwise, GDB should ignore this ‘N:R’ pair and go on to the d49772 3 a49774 3 ‘watch’ ‘rwatch’ ‘awatch’ d49778 2 a49779 2 ‘syscall_entry’ ‘syscall_return’ d49783 1 a49783 1 ‘library’ d49785 1 a49785 1 GDB should use ‘qXfer:libraries:read’ to fetch a new list of d49788 1 a49788 1 ‘replaylog’ d49792 1 a49792 1 of R will be either ‘begin’ or ‘end’. *Note Reverse d49795 1 a49795 1 ‘swbreak’ d49809 2 a49810 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d49815 1 a49815 1 ‘hwbreak’ d49819 1 a49819 1 The same remarks about ‘qSupported’ and non-stop mode above d49822 2 a49823 2 ‘fork’ The packet indicates that ‘fork’ was called, and R is the d49830 2 a49831 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d49834 2 a49835 2 ‘vfork’ The packet indicates that ‘vfork’ was called, and R is the d49842 2 a49843 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d49846 1 a49846 1 ‘vforkdone’ d49848 1 a49848 1 has either called ‘exec’ or terminated, so that the address d49855 2 a49856 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d49859 2 a49860 2 ‘exec’ The packet indicates that ‘execve’ was called, and R is the d49866 2 a49867 2 appropriate ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ d49870 2 a49871 2 ‘clone’ The packet indicates that ‘clone’ was called, and R is the d49879 1 a49879 1 ‘create’ d49884 1 a49884 1 QThreadEvents:: packet. See also the ‘w’ (*note thread exit d49887 2 a49888 2 ‘W AA’ ‘W AA ; process:PID’ d49898 2 a49899 2 ‘X AA’ ‘X AA ; process:PID’ d49908 1 a49908 1 ‘w AA ; TID’ d49916 1 a49916 1 ‘N’ d49922 2 a49923 2 though the process is still alive, and thus no ‘W’ stop reply is sent, no thread is actually executing either. The ‘N’ stop reply d49927 2 a49928 2 ‘qSupported’ feature (*note qSupported::). The remote stub must also supply the appropriate ‘qSupported’ feature indicating d49931 2 a49932 2 ‘O XX...’ ‘XX...’ is hex encoding of ASCII data, to be written as the d49935 1 a49935 1 ‘W’, ‘T’, etc. This reply is not permitted in non-stop mode. d49937 1 a49937 1 ‘F CALL-ID,PARAMETER...’ d49944 1 a49944 1 ‘PARAMETER...’ is a list of parameters as defined for this very d49949 2 a49950 2 appropriate ‘F’ packet and keeps up waiting for the next reply packet from the target. The latest ‘C’, ‘c’, ‘S’ or ‘s’ action is d49960 2 a49961 2 Packets starting with ‘q’ are “general query packets”; packets starting with ‘Q’ are “general set packets”. General query and set packets are a d49967 1 a49967 1 may use a ‘qSymbol’ packet to exchange symbol definitions with the stub. d49970 3 a49972 3 • The name must not contain commas, colons or semicolons. • Most GDB query and set packets have a leading upper case letter. • The names of custom vendor packets should use a company prefix, in d49974 2 a49975 2 the Acme Corporation might begin with ‘qacme.foo’ (for querying foos) or ‘Qacme.bar’ (for setting bars). d49978 2 a49979 2 parameters by a ‘:’; the parameters themselves should be separated by ‘,’ or ‘;’. Stubs must be careful to match the full packet name, and d49981 2 a49982 2 share a common prefix. New packets should not begin with ‘qC’, ‘qP’, or ‘qL’(1). d49992 2 a49993 2 ‘QAgent:1’ ‘QAgent:0’ d49997 1 a49997 1 ‘QAllow:OP:VAL...’ d50000 2 a50001 2 Possible values for OP include ‘WriteReg’, ‘WriteMem’, ‘InsertBreak’, ‘InsertTrace’, ‘InsertFastTrace’, and ‘Stop’. VAL d50008 1 a50008 1 ‘qC’ d50012 1 a50012 1 ‘QC THREAD-ID’ d50015 1 a50015 1 ‘(anything else)’ d50018 1 a50018 1 ‘qCRC:ADDR,LENGTH’ d50022 1 a50022 1 ‘0xffffffff’ is used to ensure leading zeros affect the CRC. d50032 1 a50032 1 ‘C CRC32’ d50035 1 a50035 1 ‘QDisableRandomization:VALUE’ d50041 1 a50041 1 randomization for processes subsequently started via ‘vRun’ d50049 1 a50049 1 ‘OK’ d50053 1 a50053 1 it, by supplying an appropriate ‘qSupported’ response (*note d50057 1 a50057 1 ‘QStartupWithShell:VALUE’ d50060 2 a50061 2 ‘gdbserver’ (*note set startup-with-shell::). This packet is used to inform ‘gdbserver’ whether it should start the inferior using a d50064 2 a50065 2 If VALUE is ‘0’, ‘gdbserver’ will not use a shell to start the inferior. If VALUE is ‘1’, ‘gdbserver’ will use a shell to start d50072 1 a50072 1 ‘OK’ d50076 1 a50076 1 it, by supplying an appropriate ‘qSupported’ response (*note d50080 1 a50080 1 Use of this packet is controlled by the ‘set startup-with-shell’ d50083 1 a50083 1 ‘QEnvironmentHexEncoded:HEX-VALUE’ d50086 1 a50086 1 This packet is used to inform ‘gdbserver’ of an environment d50094 1 a50094 1 VALUE. If the variable has no value (i.e., the value is ‘null’), d50101 1 a50101 1 ‘OK’ d50105 1 a50105 1 it, by supplying an appropriate ‘qSupported’ response (*note d50109 1 a50109 1 This packet is related to the ‘set environment’ command; *note set d50112 1 a50112 1 ‘QEnvironmentUnset:HEX-VALUE’ d50115 1 a50115 1 used to inform ‘gdbserver’ of an environment variable that has been d50125 1 a50125 1 ‘OK’ d50129 1 a50129 1 it, by supplying an appropriate ‘qSupported’ response (*note d50133 1 a50133 1 This packet is related to the ‘unset environment’ command; *note d50136 1 a50136 1 ‘QEnvironmentReset’ d50141 3 a50143 3 initially present in the environment). It is sent to ‘gdbserver’ before the ‘QEnvironmentHexEncoded’ (*note QEnvironmentHexEncoded::) and the ‘QEnvironmentUnset’ (*note d50150 1 a50150 1 ‘OK’ d50154 1 a50154 1 it, by supplying an appropriate ‘qSupported’ response (*note d50158 1 a50158 1 ‘QSetWorkingDir:[DIRECTORY]’ d50173 1 a50173 1 ‘OK’ d50176 2 a50177 2 ‘qfThreadInfo’ ‘qsThreadInfo’ d50182 2 a50183 2 first query of the sequence will be the ‘qfThreadInfo’ query; subsequent queries in the sequence will be the ‘qsThreadInfo’ d50186 1 a50186 1 NOTE: This packet replaces the ‘qL’ query (see below). d50189 1 a50189 1 ‘m THREAD-ID’ d50191 1 a50191 1 ‘m THREAD-ID,THREAD-ID...’ d50193 2 a50194 2 ‘l’ (lower case letter ‘L’) denotes end of list. d50198 3 a50200 3 reply with a request for more thread ids (using the ‘qs’ form of the query), until the target responds with ‘l’ (lower-case ell, for “last”). Refer to *note thread-id syntax::, for the format of the d50203 1 a50203 1 _Note: GDB will send the ‘qfThreadInfo’ query during the initial d50207 1 a50207 1 ID in the ‘qfThreadInfo’ reply is suitable for being stopped by d50210 1 a50210 1 ‘qGetTLSAddr:THREAD-ID,OFFSET,LM’ d50230 1 a50230 1 ‘XX...’ d50234 1 a50234 1 ‘qGetTIBAddr:THREAD-ID’ d50240 1 a50240 1 ‘XX...’ d50244 1 a50244 1 ‘qL STARTFLAG THREADCOUNT NEXTTHREAD’ d50252 1 a50252 1 Don't use this packet; use the ‘qfThreadInfo’ query instead (see d50256 1 a50256 1 ‘qM COUNT DONE ARGTHREAD THREAD...’ d50263 1 a50263 1 ‘remote.c:parse_threadlist_response()’. d50265 1 a50265 1 ‘qMemTags:START ADDRESS,LENGTH:TYPE’ d50279 1 a50279 1 for memory tagging via ‘qSupported’. d50282 1 a50282 1 ‘MXX...’ d50286 1 a50286 1 ‘qIsAddressTagged:ADDRESS’ d50288 1 a50288 1 it's said to be “tagged”. The target is responsible for checking d50297 1 a50297 1 ‘‘01’’ d50300 1 a50300 1 ‘‘00’’ d50303 1 a50303 1 ‘QMemTags:START ADDRESS,LENGTH:TYPE:TAG BYTES’ d50334 1 a50334 1 for memory tagging via ‘qSupported’. d50337 1 a50337 1 ‘OK’ d50341 1 a50341 1 ‘qOffsets’ d50346 3 a50348 3 ‘Text=XXX;Data=YYY[;Bss=ZZZ]’ Relocate the ‘Text’ section by XXX from its original address. Relocate the ‘Data’ section by YYY from its original address. d50350 1 a50350 1 ELF ‘PT_LOAD’ program headers), GDB will relocate entire d50353 3 a50355 3 _Note: while a ‘Bss’ offset may be included in the response, GDB ignores this and instead applies the ‘Data’ offset to the ‘Bss’ section._ d50357 1 a50357 1 ‘TextSeg=XXX[;DataSeg=YYY]’ d50360 1 a50360 1 XXX. If ‘DataSeg’ is specified, relocate the second segment, d50368 1 a50368 1 ‘qP MODE THREAD-ID’ d50372 1 a50372 1 Don't use this packet; use the ‘qThreadExtraInfo’ query instead d50375 1 a50375 1 Reply: see ‘remote.c:remote_unpack_thread_info_response()’. d50377 3 a50379 3 ‘QNonStop:1’ ‘QNonStop:0’ Enter non-stop (‘QNonStop:1’) or all-stop (‘QNonStop:0’) mode. d50383 1 a50383 1 ‘OK’ d50387 7 a50393 7 it, by supplying an appropriate ‘qSupported’ response (*note qSupported::). Use of this packet is controlled by the ‘set non-stop’ command; *note Non-Stop Mode::. ‘QCatchSyscalls:1 [;SYSNO]...’ ‘QCatchSyscalls:0’ Enable (‘QCatchSyscalls:1’) or disable (‘QCatchSyscalls:0’) d50396 1 a50396 1 For ‘QCatchSyscalls:1’, each listed syscall SYSNO (encoded in hex) d50402 1 a50402 1 ‘catch syscall’ commands. However, it is more efficient to only d50405 2 a50406 2 Multiple ‘QCatchSyscalls:1’ packets do not combine; any earlier ‘QCatchSyscalls:1’ list is completely replaced by the new list. d50408 1 a50408 1 If the inferior process execs, the state of ‘QCatchSyscalls’ is d50415 1 a50415 1 ‘OK’ d50418 1 a50418 1 Use of this packet is controlled by the ‘set remote catch-syscalls’ d50421 1 a50421 1 it, by supplying an appropriate ‘qSupported’ response (*note d50424 1 a50424 1 ‘QPassSignals: SIGNAL [;SIGNAL]...’ d50430 2 a50431 2 signals should be reported to GDB. Multiple ‘QPassSignals’ packets do not combine; any earlier ‘QPassSignals’ list is completely d50433 1 a50433 1 using ‘handle SIGNAL nostop noprint pass’. d50436 1 a50436 1 ‘OK’ d50439 1 a50439 1 Use of this packet is controlled by the ‘set remote pass-signals’ d50442 1 a50442 1 it, by supplying an appropriate ‘qSupported’ response (*note d50445 1 a50445 1 ‘QProgramSignals: SIGNAL [;SIGNAL]...’ d50463 2 a50464 2 ‘QProgramSignals’ packets do not combine; any earlier ‘QProgramSignals’ list is completely replaced by the new list. d50467 1 a50467 1 ‘OK’ d50470 2 a50471 2 Use of this packet is controlled by the ‘set remote program-signals’ command (*note set remote program-signals: Remote d50473 1 a50473 1 stub must request it, by supplying an appropriate ‘qSupported’ d50476 2 a50477 2 ‘QThreadEvents:1’ ‘QThreadEvents:0’ d50479 1 a50479 1 Enable (‘QThreadEvents:1’) or disable (‘QThreadEvents:0’) reporting d50487 1 a50487 1 including ‘QThreadEvents+’ in its ‘qSupported’ reply. d50495 1 a50495 1 ‘OK’ d50498 1 a50498 1 Use of this packet is controlled by the ‘set remote thread-events’ d50501 1 a50501 1 ‘QThreadOptions[;OPTIONS[:THREAD-ID]]...’ d50510 1 a50510 1 to apply to all threads of a process by using the ‘pPID.-1’ form of d50515 1 a50515 1 options, and is the bitwise ‘OR’ of the following values. All d50518 1 a50518 1 ‘GDB_THREAD_OPTION_CLONE (0x1)’ d50523 1 a50523 1 ‘GDB_THREAD_OPTION_EXIT (0x2)’ d50526 3 a50528 2 For example, GDB enables the ‘GDB_THREAD_OPTION_EXIT’ and ‘GDB_THREAD_OPTION_CLONE’ options when single-stepping a thread d50531 2 a50532 2 • If the single-stepped thread exits (e.g., it executes a thread exit system call), enabling ‘GDB_THREAD_OPTION_EXIT’ prevents d50537 1 a50537 1 • If the single-stepped thread spawns a new clone child (i.e., d50539 1 a50539 1 ‘GDB_THREAD_OPTION_CLONE’ halts the cloned thread before it d50543 1 a50543 1 − If the breakpoint is stepped-over in-line, the spawned d50549 1 a50549 1 − If displaced (out-of-line) stepping is used, the cloned d50556 2 a50557 2 supports it by including ‘QThreadOptions=SUPPORTED_OPTIONS’ in its ‘qSupported’ reply. d50560 1 a50560 1 ‘OK’ d50563 1 a50563 1 Use of this packet is controlled by the ‘set remote thread-options’ d50566 1 a50566 1 ‘qRcmd,COMMAND’ d50570 1 a50570 1 respond with a number of intermediate ‘OOUTPUT’ console output d50575 1 a50575 1 ‘OK’ d50577 1 a50577 1 ‘OUTPUT’ d50580 1 a50580 1 Unlike most packets, this packet does not support ‘E.ERRTEXT’-style d50583 2 a50584 2 (Note that the ‘qRcmd’ packet's name is separated from the command by a ‘,’, not a ‘:’, contrary to the naming conventions above. d50587 1 a50587 1 ‘qSearch:memory:ADDRESS;LENGTH;SEARCH-PATTERN’ d50593 1 a50593 1 ‘0’ d50595 1 a50595 1 ‘1,address’ d50598 2 a50599 2 ‘QStartNoAckMode’ Request that the remote stub disable the normal ‘+’/‘-’ protocol d50603 1 a50603 1 ‘OK’ d50606 1 a50606 1 send or expect further ‘+’/‘-’ acknowledgments in the current d50609 1 a50609 1 ‘qSupported [:GDBFEATURE [;GDBFEATURE]... ]’ d50613 1 a50613 1 ‘qSupported’ also consolidates multiple feature probes at startup, d50626 1 a50626 1 ‘STUBFEATURE [;STUBFEATURE]...’ d50632 1 a50632 1 ‘qSupported’ packet, or a STUBFEATURE in the response) are: d50634 1 a50634 1 ‘NAME=VALUE’ d50638 1 a50638 1 ‘NAME+’ d50641 1 a50641 1 ‘NAME-’ d50643 1 a50643 1 ‘NAME?’ d50649 1 a50649 1 Whenever the stub receives a ‘qSupported’ request, the supplied set d50657 1 a50657 1 ‘multiprocess’ d50661 1 a50661 1 by including ‘multiprocess+’ in its ‘qSupported’ reply. *Note d50664 1 a50664 1 ‘xmlRegisters’ d50666 1 a50666 1 description. If the stub sees ‘xmlRegisters=’ with target d50670 2 a50671 2 ‘qRelocInsn’ This feature indicates whether GDB supports the ‘qRelocInsn’ d50675 1 a50675 1 ‘swbreak’ d50680 1 a50680 1 ‘hwbreak’ d50685 1 a50685 1 ‘fork-events’ d50689 1 a50689 1 by including ‘fork-events+’ in its ‘qSupported’ reply. d50691 1 a50691 1 ‘vfork-events’ d50695 1 a50695 1 by including ‘vfork-events+’ in its ‘qSupported’ reply. d50697 1 a50697 1 ‘exec-events’ d50701 1 a50701 1 by including ‘exec-events+’ in its ‘qSupported’ reply. d50703 1 a50703 1 ‘vContSupported’ d50705 1 a50705 1 actions in the reply to ‘vCont?’ packet. d50708 1 a50708 1 which sends a ‘qSupported’ packet supports receiving packets of d50713 1 a50713 1 ‘multiprocess’ feature is an example of such a feature. The stub's d50722 2 a50723 2 should respond with a ‘+’ form response. Other features require values, and the stub should respond with an ‘=’ form response. d50726 2 a50727 2 ‘qSupported’ is not available or if the feature is not mentioned in the ‘qSupported’ response. The default values are fixed; a stub is d50742 1 a50742 1 ‘PacketSize’ Yes ‘-’ No d50744 1 a50744 1 ‘qXfer:auxv:read’ No ‘-’ Yes d50746 1 a50746 1 ‘qXfer:btrace:read’ No ‘-’ Yes d50748 1 a50748 1 ‘qXfer:btrace-conf:read’ No ‘-’ Yes d50750 1 a50750 1 ‘qXfer:exec-file:read’ No ‘-’ Yes d50752 1 a50752 1 ‘qXfer:features:read’ No ‘-’ Yes d50754 1 a50754 1 ‘qXfer:libraries:read’ No ‘-’ Yes d50756 1 a50756 1 ‘qXfer:libraries-svr4:read’No ‘-’ Yes d50758 1 a50758 1 ‘augmented-libraries-svr4-read’No ‘-’ No d50760 1 a50760 1 ‘qXfer:memory-map:read’ No ‘-’ Yes d50762 1 a50762 1 ‘qXfer:sdata:read’ No ‘-’ Yes d50764 1 a50764 1 ‘qXfer:siginfo:read’ No ‘-’ Yes d50766 1 a50766 1 ‘qXfer:siginfo:write’ No ‘-’ Yes d50768 1 a50768 1 ‘qXfer:threads:read’ No ‘-’ Yes d50770 1 a50770 1 ‘qXfer:traceframe-info:read’No ‘-’ Yes d50772 1 a50772 1 ‘qXfer:uib:read’ No ‘-’ Yes d50774 1 a50774 1 ‘qXfer:fdpic:read’ No ‘-’ Yes d50776 1 a50776 1 ‘Qbtrace:off’ Yes ‘-’ Yes d50778 1 a50778 1 ‘Qbtrace:bts’ Yes ‘-’ Yes d50780 1 a50780 1 ‘Qbtrace:pt’ Yes ‘-’ Yes d50782 1 a50782 1 ‘Qbtrace-conf:bts:size’ Yes ‘-’ Yes d50784 1 a50784 1 ‘Qbtrace-conf:pt:size’ Yes ‘-’ Yes d50786 1 a50786 1 ‘QNonStop’ No ‘-’ Yes d50788 1 a50788 1 ‘QCatchSyscalls’ No ‘-’ Yes d50790 1 a50790 1 ‘QPassSignals’ No ‘-’ Yes d50792 1 a50792 1 ‘QStartNoAckMode’ No ‘-’ Yes d50794 1 a50794 1 ‘multiprocess’ No ‘-’ No d50796 1 a50796 1 ‘ConditionalBreakpoints’ No ‘-’ No d50798 1 a50798 1 ‘ConditionalTracepoints’ No ‘-’ No d50800 1 a50800 1 ‘ReverseContinue’ No ‘-’ No d50802 1 a50802 1 ‘ReverseStep’ No ‘-’ No d50804 1 a50804 1 ‘TracepointSource’ No ‘-’ No d50806 1 a50806 1 ‘QAgent’ No ‘-’ No d50808 1 a50808 1 ‘QAllow’ No ‘-’ No d50810 1 a50810 1 ‘QDisableRandomization’ No ‘-’ No d50812 1 a50812 1 ‘EnableDisableTracepoints’No ‘-’ No d50814 1 a50814 1 ‘QTBuffer:size’ No ‘-’ No d50816 1 a50816 1 ‘tracenz’ No ‘-’ No d50818 1 a50818 1 ‘BreakpointCommands’ No ‘-’ No d50820 1 a50820 1 ‘swbreak’ No ‘-’ No d50822 1 a50822 1 ‘hwbreak’ No ‘-’ No d50824 1 a50824 1 ‘fork-events’ No ‘-’ No d50826 1 a50826 1 ‘vfork-events’ No ‘-’ No d50828 1 a50828 1 ‘exec-events’ No ‘-’ No d50830 1 a50830 1 ‘QThreadEvents’ No ‘-’ No d50832 1 a50832 1 ‘QThreadOptions’ Yes ‘-’ No d50834 1 a50834 1 ‘no-resumed’ No ‘-’ No d50836 1 a50836 1 ‘memory-tagging’ No ‘-’ No d50841 1 a50841 1 ‘PacketSize=BYTES’ d50850 1 a50850 1 guesses based on the size of the ‘g’ packet response. d50852 2 a50853 2 ‘qXfer:auxv:read’ The remote stub understands the ‘qXfer:auxv:read’ packet d50856 2 a50857 2 ‘qXfer:btrace:read’ The remote stub understands the ‘qXfer:btrace:read’ packet d50860 2 a50861 2 ‘qXfer:btrace-conf:read’ The remote stub understands the ‘qXfer:btrace-conf:read’ d50864 2 a50865 2 ‘qXfer:exec-file:read’ The remote stub understands the ‘qXfer:exec-file:read’ packet d50868 2 a50869 2 ‘qXfer:features:read’ The remote stub understands the ‘qXfer:features:read’ packet d50872 2 a50873 2 ‘qXfer:libraries:read’ The remote stub understands the ‘qXfer:libraries:read’ packet d50876 2 a50877 2 ‘qXfer:libraries-svr4:read’ The remote stub understands the ‘qXfer:libraries-svr4:read’ d50880 1 a50880 1 ‘augmented-libraries-svr4-read’ d50882 1 a50882 1 ‘qXfer:libraries-svr4:read’ packet (*note qXfer svr4 library d50885 2 a50886 2 ‘qXfer:memory-map:read’ The remote stub understands the ‘qXfer:memory-map:read’ packet d50889 2 a50890 2 ‘qXfer:sdata:read’ The remote stub understands the ‘qXfer:sdata:read’ packet d50893 2 a50894 2 ‘qXfer:siginfo:read’ The remote stub understands the ‘qXfer:siginfo:read’ packet d50897 2 a50898 2 ‘qXfer:siginfo:write’ The remote stub understands the ‘qXfer:siginfo:write’ packet d50901 2 a50902 2 ‘qXfer:threads:read’ The remote stub understands the ‘qXfer:threads:read’ packet d50905 2 a50906 2 ‘qXfer:traceframe-info:read’ The remote stub understands the ‘qXfer:traceframe-info:read’ d50909 2 a50910 2 ‘qXfer:uib:read’ The remote stub understands the ‘qXfer:uib:read’ packet (*note d50913 2 a50914 2 ‘qXfer:fdpic:read’ The remote stub understands the ‘qXfer:fdpic:read’ packet d50917 2 a50918 2 ‘QNonStop’ The remote stub understands the ‘QNonStop’ packet (*note d50921 2 a50922 2 ‘QCatchSyscalls’ The remote stub understands the ‘QCatchSyscalls’ packet (*note d50925 2 a50926 2 ‘QPassSignals’ The remote stub understands the ‘QPassSignals’ packet (*note d50929 2 a50930 2 ‘QStartNoAckMode’ The remote stub understands the ‘QStartNoAckMode’ packet and d50934 1 a50934 1 ‘multiprocess’ d50938 2 a50939 2 thread-id syntax::), and add process IDs to the ‘D’ packet and ‘W’ and ‘X’ replies. Note that reporting this feature d50944 1 a50944 1 supports them in its ‘qSupported’ request. d50946 2 a50947 2 ‘qXfer:osdata:read’ The remote stub understands the ‘qXfer:osdata:read’ packet d50950 1 a50950 1 ‘ConditionalBreakpoints’ d50956 1 a50956 1 ‘ConditionalTracepoints’ d50960 1 a50960 1 ‘ReverseContinue’ d50964 1 a50964 1 ‘ReverseStep’ d50968 2 a50969 2 ‘TracepointSource’ The remote stub understands the ‘QTDPsrc’ packet that supplies d50972 2 a50973 2 ‘QAgent’ The remote stub understands the ‘QAgent’ packet. d50975 2 a50976 2 ‘QAllow’ The remote stub understands the ‘QAllow’ packet. d50978 2 a50979 2 ‘QDisableRandomization’ The remote stub understands the ‘QDisableRandomization’ d50982 1 a50982 1 ‘StaticTracepoint’ d50985 1 a50985 1 ‘InstallInTrace’ d50988 3 a50990 3 ‘EnableDisableTracepoints’ The remote stub supports the ‘QTEnable’ (*note QTEnable::) and ‘QTDisable’ (*note QTDisable::) packets that allow tracepoints d50994 2 a50995 2 ‘QTBuffer:size’ The remote stub supports the ‘QTBuffer:size’ (*note d50999 2 a51000 2 ‘tracenz’ The remote stub supports the ‘tracenz’ bytecode for collecting d51004 1 a51004 1 ‘BreakpointCommands’ d51008 2 a51009 2 ‘Qbtrace:off’ The remote stub understands the ‘Qbtrace:off’ packet. d51011 2 a51012 2 ‘Qbtrace:bts’ The remote stub understands the ‘Qbtrace:bts’ packet. d51014 2 a51015 2 ‘Qbtrace:pt’ The remote stub understands the ‘Qbtrace:pt’ packet. d51017 2 a51018 2 ‘Qbtrace-conf:bts:size’ The remote stub understands the ‘Qbtrace-conf:bts:size’ d51021 2 a51022 2 ‘Qbtrace-conf:pt:size’ The remote stub understands the ‘Qbtrace-conf:pt:size’ packet. d51024 2 a51025 2 ‘swbreak’ The remote stub reports the ‘swbreak’ stop reason for memory d51028 2 a51029 2 ‘hwbreak’ The remote stub reports the ‘hwbreak’ stop reason for hardware d51032 2 a51033 2 ‘fork-events’ The remote stub reports the ‘fork’ stop reason for fork d51036 2 a51037 2 ‘vfork-events’ The remote stub reports the ‘vfork’ stop reason for vfork d51040 2 a51041 2 ‘exec-events’ The remote stub reports the ‘exec’ stop reason for exec d51044 1 a51044 1 ‘vContSupported’ d51046 1 a51046 1 ‘vCont?’ packet. d51048 2 a51049 2 ‘QThreadEvents’ The remote stub understands the ‘QThreadEvents’ packet. d51051 2 a51052 2 ‘QThreadOptions=SUPPORTED_OPTIONS’ The remote stub understands the ‘QThreadOptions’ packet. d51055 1 a51055 1 as the OPTIONS parameter of the ‘QThreadOptions’ packet, d51058 2 a51059 2 ‘no-resumed’ The remote stub reports the ‘N’ stop reply. d51061 1 a51061 1 ‘memory-tagging’ d51063 2 a51064 2 tagging functionality and understands the ‘qMemTags’ (*note qMemTags::) and ‘QMemTags’ (*note QMemTags::) packets. d51067 2 a51068 2 to the ‘/proc/PID/smaps’ file so memory mapping page flags can be inspected, if ‘qIsAddressTagged’ (*note qIsAddressTagged::) d51070 1 a51070 1 ‘/proc/PID/smaps’ file is done via ‘vFile’ requests. d51072 1 a51072 1 ‘qSymbol::’ d51078 1 a51078 1 ‘OK’ d51080 1 a51080 1 ‘qSymbol:SYM_NAME’ d51083 1 a51083 1 ‘qSymbol:SYM_VALUE:SYM_NAME’ message, described below. d51085 1 a51085 1 ‘qSymbol:SYM_VALUE:SYM_NAME’ d51095 1 a51095 1 ‘OK’ d51097 1 a51097 1 ‘qSymbol:SYM_NAME’ d51102 10 a51111 10 ‘qTBuffer’ ‘QTBuffer’ ‘QTDisconnected’ ‘QTDP’ ‘QTDPsrc’ ‘QTDV’ ‘qTfP’ ‘qTfV’ ‘QTFrame’ ‘qTMinFTPILen’ d51115 1 a51115 1 ‘qThreadExtraInfo,THREAD-ID’ d51120 1 a51120 1 the thread. The string is displayed in GDB's ‘info threads’ d51122 1 a51122 1 ‘Runnable’, or ‘Blocked on Mutex’. d51125 2 a51126 2 ‘XX...’ Where ‘XX...’ is a hex encoding of ASCII data, comprising the d51130 2 a51131 2 (Note that the ‘qThreadExtraInfo’ packet's name is separated from the command by a ‘,’, not a ‘:’, contrary to the naming conventions d51134 16 a51149 16 ‘QTNotes’ ‘qTP’ ‘QTSave’ ‘qTsP’ ‘qTsV’ ‘QTStart’ ‘QTStop’ ‘QTEnable’ ‘QTDisable’ ‘QTinit’ ‘QTro’ ‘qTStatus’ ‘qTV’ ‘qTfSTM’ ‘qTsSTM’ ‘qTSTMat’ d51152 1 a51152 1 ‘qXfer:OBJECT:read:ANNEX:OFFSET,LENGTH’ d51160 1 a51160 1 ‘m DATA’ d51163 1 a51163 1 permitted to return ‘m’ even for the last valid block of data, d51168 1 a51168 1 ‘l DATA’ d51173 1 a51173 1 ‘l’ d51178 1 a51178 1 the ‘qXfer:OBJECT:read:...’ requests use the same reply formats, d51181 2 a51182 2 ‘qXfer:auxv:read::OFFSET,LENGTH’ Access the target's “auxiliary vector”. *Note auxiliary d51186 1 a51186 1 request it, by supplying an appropriate ‘qSupported’ response d51189 1 a51189 1 ‘qXfer:btrace:read:ANNEX:OFFSET,LENGTH’ d51192 1 a51192 1 Branch Trace Format::. The annex part of the generic ‘qXfer’ d51195 1 a51195 1 ‘all’ d51198 1 a51198 1 ‘new’ d51202 1 a51202 1 ‘delta’ d51213 1 a51213 1 request it by supplying an appropriate ‘qSupported’ response d51216 1 a51216 1 ‘qXfer:btrace-conf:read::OFFSET,LENGTH’ d51222 1 a51222 1 request it by supplying an appropriate ‘qSupported’ response d51225 1 a51225 1 ‘qXfer:exec-file:read:ANNEX:OFFSET,LENGTH’ d51234 1 a51234 1 request it, by supplying an appropriate ‘qSupported’ response d51237 2 a51238 2 ‘qXfer:features:read:ANNEX:OFFSET,LENGTH’ Access the “target description”. *Note Target Descriptions::. d51240 1 a51240 1 description is always loaded from the ‘target.xml’ annex. d51243 1 a51243 1 request it, by supplying an appropriate ‘qSupported’ response d51246 1 a51246 1 ‘qXfer:libraries:read:ANNEX:OFFSET,LENGTH’ d51248 1 a51248 1 List Format::. The annex part of the generic ‘qXfer’ packet d51257 1 a51257 1 request it, by supplying an appropriate ‘qSupported’ response d51260 1 a51260 1 ‘qXfer:libraries-svr4:read:ANNEX:OFFSET,LENGTH’ d51263 1 a51263 1 Targets::. The annex part of the generic ‘qXfer’ packet must d51266 1 a51266 1 ‘qSupported’ response (*note qXfer read::, *note d51274 1 a51274 1 request it, by supplying an appropriate ‘qSupported’ response d51278 2 a51279 2 this packet then the annex part of the generic ‘qXfer’ packet may contain a semicolon-separated list of ‘NAME=VALUE’ d51282 1 a51282 1 ‘start=ADDRESS’ d51284 2 a51285 2 ‘struct link_map’ to start reading the library list from. If unset or zero then the first ‘struct link_map’ in the d51288 1 a51288 1 ‘prev=ADDRESS’ d51290 4 a51293 4 ‘struct link_map’ immediately preceding the ‘struct link_map’ specified by the ‘start’ argument. If unset or zero then the remote stub will expect that no ‘struct link_map’ exists prior to the starting point. d51295 1 a51295 1 ‘lmid=LMID’ d51297 1 a51297 1 This is currently only used together with ‘start’ to d51301 1 a51301 1 include ‘lmid="0x0"’. d51306 3 a51308 3 ‘qXfer:memory-map:read::OFFSET,LENGTH’ Access the target's “memory-map”. *Note Memory Map Format::. The annex part of the generic ‘qXfer’ packet must be empty d51312 1 a51312 1 request it, by supplying an appropriate ‘qSupported’ response d51315 1 a51315 1 ‘qXfer:sdata:read::OFFSET,LENGTH’ d51318 1 a51318 1 information. The annex part of the generic ‘qXfer’ packet d51323 1 a51323 1 request it, by supplying an appropriate ‘qSupported’ response d51326 1 a51326 1 ‘qXfer:siginfo:read::OFFSET,LENGTH’ d51328 1 a51328 1 system. The annex part of the generic ‘qXfer’ packet must be d51332 1 a51332 1 request it, by supplying an appropriate ‘qSupported’ response d51335 1 a51335 1 ‘qXfer:threads:read::OFFSET,LENGTH’ d51337 1 a51337 1 Format::. The annex part of the generic ‘qXfer’ packet must d51341 1 a51341 1 request it, by supplying an appropriate ‘qSupported’ response d51344 1 a51344 1 ‘qXfer:traceframe-info:read::OFFSET,LENGTH’ d51348 1 a51348 1 ‘qXfer’ packet must be empty (*note qXfer read::). d51351 1 a51351 1 request it, by supplying an appropriate ‘qSupported’ response d51354 1 a51354 1 ‘qXfer:uib:read:PC:OFFSET,LENGTH’ d51361 4 a51364 4 ‘qXfer:fdpic:read:ANNEX:OFFSET,LENGTH’ Read contents of ‘loadmap’s on the target system. The annex, either ‘exec’ or ‘interp’, specifies which ‘loadmap’, executable ‘loadmap’ or interpreter ‘loadmap’ to read. d51367 1 a51367 1 request it, by supplying an appropriate ‘qSupported’ response d51370 2 a51371 2 ‘qXfer:osdata:read::OFFSET,LENGTH’ Access the target's “operating system information”. *Note d51374 1 a51374 1 ‘qXfer:OBJECT:write:ANNEX:OFFSET:DATA...’ d51383 1 a51383 1 ‘NN’ d51388 1 a51388 1 the ‘qXfer:OBJECT:write:...’ requests use the same reply formats, d51391 1 a51391 1 ‘qXfer:siginfo:write::OFFSET:DATA...’ d51393 1 a51393 1 system. The annex part of the generic ‘qXfer’ packet must be d51397 1 a51397 1 request it, by supplying an appropriate ‘qSupported’ response d51400 1 a51400 1 ‘qXfer:OBJECT:OPERATION:...’ d51406 1 a51406 1 ‘qAttached:PID’ d51412 1 a51412 1 query packet will be simplified as ‘qAttached’. d51416 1 a51416 1 ‘quit’ command. d51419 1 a51419 1 ‘1’ d51421 1 a51421 1 ‘0’ d51424 1 a51424 1 ‘Qbtrace:bts’ d51429 1 a51429 1 ‘OK’ d51432 1 a51432 1 ‘Qbtrace:pt’ d51437 1 a51437 1 ‘OK’ d51440 1 a51440 1 ‘Qbtrace:off’ d51444 1 a51444 1 ‘OK’ d51447 1 a51447 1 ‘Qbtrace-conf:bts:size=VALUE’ d51452 1 a51452 1 ‘OK’ d51455 1 a51455 1 ‘Qbtrace-conf:pt:size=VALUE’ d51460 1 a51460 1 ‘OK’ d51465 1 a51465 1 (1) The ‘qP’ and ‘qL’ packets predate these conventions, and have d51467 1 a51467 1 are in widespread use in places that are difficult to upgrade. The ‘qC’ d51503 1 a51503 1 These breakpoint kinds are defined for the ‘Z0’ and ‘Z1’ packets. d51520 1 a51520 1 These memory tag types are defined for the ‘qMemTag’ and ‘QMemTag’ d51546 1 a51546 1 The following ‘g’/‘G’ packets have previously been defined. In the d51560 2 a51561 2 (including thirty-two bit registers such as ‘sr’). The ordering is the same as ‘MIPS32’. d51569 1 a51569 1 These breakpoint kinds are defined for the ‘Z0’ and ‘Z1’ packets. d51592 3 a51594 3 ‘QTDP:N:ADDR:ENA:STEP:PASS[:FFLEN][:XLEN,BYTES][-]’ Create a new tracepoint, number N, at ADDR. If ENA is ‘E’, then the tracepoint is enabled; if it is ‘D’, then the tracepoint is d51596 1 a51596 1 gives its pass count. If an ‘F’ is present, then the tracepoint is d51599 1 a51599 1 If an ‘X’ is present, it introduces a tracepoint condition, which d51602 1 a51602 1 described below. If the trailing ‘-’ is present, further ‘QTDP’ d51606 1 a51606 1 ‘OK’ d51608 1 a51608 1 ‘qRelocInsn’ d51611 1 a51611 1 ‘QTDP:-N:ADDR:[S]ACTION...[-]’ d51613 1 a51613 1 ADDR must be the same as in the initial ‘QTDP’ packet for this d51615 2 a51616 2 ‘QTDP’ packet that ended with a ‘-’. If the trailing ‘-’ is present, further ‘QTDP’ packets will follow, specifying more d51620 1 a51620 1 can have an ‘S’ before its first ACTION. If such a packet is sent, d51623 1 a51623 1 the tracepoint is first hit. If no action packet has an ‘S’, then d51626 1 a51626 1 The ‘ACTION...’ portion of the packet is a series of actions, d51630 1 a51630 1 ‘R MASK’ d51637 1 a51637 1 ‘M BASEREG,OFFSET,LEN’ d51639 1 a51639 1 register number BASEREG, plus OFFSET. If BASEREG is ‘-1’, d51642 1 a51642 1 parameters are all unsigned hexadecimal values (the ‘-1’ value d51645 1 a51645 1 ‘X LEN,EXPR’ d51653 1 a51653 1 Any number of actions may be packed together in a single ‘QTDP’ d51655 4 a51658 4 length (400 bytes, for many stubs). There may be only one ‘R’ action per tracepoint, and it must precede any ‘M’ or ‘X’ actions. Any registers referred to by ‘M’ and ‘X’ actions must be collected by a preceding ‘R’ action. (The "while-stepping" actions are d51663 1 a51663 1 ‘OK’ d51665 1 a51665 1 ‘qRelocInsn’ d51668 1 a51668 1 ‘QTDPsrc:N:ADDR:TYPE:START:SLEN:BYTES’ d51672 1 a51672 1 of the tracepoint part, such as ‘cond’ for the tracepoint's d51681 2 a51682 2 The available string types are ‘at’ for the location, ‘cond’ for the conditional, and ‘cmd’ for an action command. GDB sends a d51687 1 a51687 1 report them back as part of the replies to the ‘qTfP’/‘qTsP’ query d51691 1 a51691 1 target replies with ‘TracepointSource’ *Note General Query d51696 1 a51696 1 discrepancy could cause ‘tdump’ not to work, or a particular trace d51699 1 a51699 1 ‘QTDV:N:VALUE:BUILTIN:NAME’ d51707 1 a51707 1 only sets BUILTIN to 1 if a previous ‘qTfV’ or ‘qTsV’ packet had it d51709 1 a51709 1 leading ‘$’) of the trace state variable. d51711 1 a51711 1 ‘QTFrame:N’ d51721 1 a51721 1 ‘F F’ d51723 1 a51723 1 a hexadecimal number. If F is ‘-1’, then there was no frame d51726 1 a51726 1 ‘T T’ d51730 2 a51731 2 ‘QTFrame:pc:ADDR’ Like ‘QTFrame:N’, but select the first tracepoint frame after the d51735 2 a51736 2 ‘QTFrame:tdp:T’ Like ‘QTFrame:N’, but select the first tracepoint frame after the d51740 2 a51741 2 ‘QTFrame:range:START:END’ Like ‘QTFrame:N’, but select the first tracepoint frame after the d51745 2 a51746 2 ‘QTFrame:outside:START:END’ Like ‘QTFrame:range:START:END’, but select the first frame d51749 1 a51749 1 ‘qTMinFTPILen’ d51760 1 a51760 1 ‘0’ d51762 1 a51762 1 ‘LENGTH’ d51767 1 a51767 1 ‘E’ d51770 1 a51770 1 ‘QTStart’ d51773 1 a51773 1 the ‘qRelocInsn’ reply (*note Relocate instruction reply packet: d51776 1 a51776 1 ‘QTStop’ d51779 1 a51779 1 ‘QTEnable:N:ADDR’ d51784 1 a51784 1 ‘QTDisable:N:ADDR’ d51787 1 a51787 1 unless ‘QTEnable:N:ADDR’ is subsequently issued. d51789 1 a51789 1 ‘QTinit’ d51792 1 a51792 1 ‘QTro:START1,END1:START2,END2:...’ d51803 1 a51803 1 ‘QTDisconnected:VALUE’ d51809 1 a51809 1 ‘qTStatus’ d51814 3 a51816 3 ‘TRUNNING[;FIELD]...’ RUNNING is a single digit ‘1’ if the trace is presently running, or ‘0’ if not. It is followed by semicolon-separated d51823 1 a51823 1 ‘tnotrun:0’ d51826 1 a51826 1 ‘tstop[:TEXT]:0’ d51832 1 a51832 1 ‘tfull:0’ d51835 1 a51835 1 ‘tdisconnected:0’ d51838 1 a51838 1 ‘tpasscount:TPNUM’ d51842 1 a51842 1 ‘terror:TEXT:TPNUM’ d51848 1 a51848 1 ‘tunknown:0’ d51857 1 a51857 1 ‘tframes:N’ d51860 1 a51860 1 ‘tcreated:N’ d51865 1 a51865 1 ‘tsize:N’ d51868 1 a51868 1 ‘tfree:N’ d51871 2 a51872 2 ‘circular:N’ The value of the circular trace buffer flag. ‘1’ means that d51874 1 a51874 1 discarded if necessary to make room, ‘0’ means that the trace d51877 3 a51879 3 ‘disconn:N’ The value of the disconnected tracing flag. ‘1’ means that tracing will continue after GDB disconnects, ‘0’ means that d51882 1 a51882 1 ‘qTP:TP:ADDR’ d51887 1 a51887 1 ‘VHITS:USAGE’ d51890 1 a51890 1 ‘while-stepping’ steps are not counted as separate hits, but d51893 1 a51893 1 ‘qTV:VAR’ d51897 1 a51897 1 ‘VVALUE’ d51905 1 a51905 1 ‘U’ d51910 2 a51911 2 ‘qTfP’ ‘qTsP’ d51913 3 a51915 3 the target. GDB sends ‘qTfP’ to get the first piece of data, and multiple ‘qTsP’ to get additional pieces. Replies to these packets generally take the form of the ‘QTDP’ packets that define d51918 2 a51919 2 ‘qTfV’ ‘qTsV’ d51921 3 a51923 3 the target. GDB sends ‘qTfV’ to get the first vari of data, and multiple ‘qTsV’ to get additional variables. Replies to these packets follow the syntax of the ‘QTDV’ packets that define trace d51926 2 a51927 2 ‘qTfSTM’ ‘qTsSTM’ d51929 2 a51930 2 exist in the target program. GDB sends ‘qTfSTM’ to get the first piece of data, and multiple ‘qTsSTM’ to get additional pieces. d51934 1 a51934 1 ‘m ADDRESS:ID:EXTRA’ d51936 1 a51936 1 ‘m ADDRESS:ID:EXTRA,ADDRESS:ID:EXTRA...’ d51938 2 a51939 2 ‘l’ (lower case letter ‘L’) denotes end of list. d51946 3 a51948 3 reply with a request for more markers (using the ‘qs’ form of the query), until the target responds with ‘l’ (lower-case ell, for “last”). d51950 1 a51950 1 ‘qTSTMat:ADDRESS’ d51953 1 a51953 1 syntax of the ‘qTfSTM’ and ‘qTsSTM’ packets that list static d51956 1 a51956 1 ‘QTSave:FILENAME’ d51962 1 a51962 1 ‘qTBuffer:OFFSET,LEN’ d51968 1 a51968 1 asked for. A reply consisting of just ‘l’ indicates that no bytes d51971 1 a51971 1 ‘QTBuffer:circular:VALUE’ d51975 1 a51975 1 ‘QTBuffer:size:SIZE’ d51977 1 a51977 1 SIZE if possible. A value of ‘-1’ tells the target to use whatever d51980 1 a51980 1 ‘QTNotes:[TYPE:TEXT][;TYPE:TEXT]...’ d51982 1 a51982 1 Allowable types include ‘user’, ‘notes’, and ‘tstop’, the TEXT d51998 1 a51998 1 respond with a number of intermediate ‘qRelocInsn’ request packets d52002 1 a52002 1 ‘QTStart’ and ‘QTDP’ packets. The format of the request is: d52004 1 a52004 1 ‘qRelocInsn:FROM;TO’ d52012 1 a52012 1 ‘qRelocInsn:ADJUSTED_SIZE’ d52022 1 a52022 1 The “Host I/O” packets allow GDB to perform I/O operations on the far d52035 1 a52035 1 ‘vFile:OPERATION: PARAMETER...’ d52047 1 a52047 1 ‘F RESULT [, ERRNO] [; ATTACHMENT]’ d52057 1 a52057 1 ‘’ d52062 1 a52062 1 ‘vFile:open: FILENAME, FLAGS, MODE’ d52070 1 a52070 1 ‘vFile:close: FD’ d52074 1 a52074 1 ‘vFile:pread: FD, COUNT, OFFSET’ d52088 1 a52088 1 ‘vFile:pwrite: FD, OFFSET, DATA’ d52091 2 a52092 2 ‘write’ system calls, there is no separate COUNT argument; the length of DATA in the packet is used. ‘vFile:pwrite’ returns the d52096 1 a52096 1 ‘vFile:fstat: FD’ d52103 1 a52103 1 ‘vFile:unlink: FILENAME’ d52107 1 a52107 1 ‘vFile:readlink: FILENAME’ d52117 2 a52118 2 ‘vFile:setfs: PID’ Select the filesystem on which ‘vFile’ operations with FILENAME d52125 1 a52125 1 Return 0 on success, or -1 if an error occurs. If ‘vFile:setfs:’ d52127 1 a52127 1 the next successful ‘vFile:setfs:’ operation. d52136 3 a52138 3 may attempt to interrupt it by sending a ‘Ctrl-C’, ‘BREAK’ or a ‘BREAK’ followed by ‘g’, control of which is specified via GDB's ‘interrupt-sequence’. d52140 2 a52141 2 The precise meaning of ‘BREAK’ is defined by the transport mechanism and may, in fact, be undefined. GDB does not currently define a ‘BREAK’ d52143 1 a52143 1 case GDB sends the ‘telnet’ BREAK sequence. d52145 1 a52145 1 ‘Ctrl-C’, on the other hand, is defined and implemented for all d52147 2 a52148 2 ‘0x03’ without any of the usual packet overhead described in the Overview section (*note Overview::). When a ‘0x03’ byte is transmitted d52150 2 a52151 2 represent an interrupt. E.g., an ‘X’ packet (*note X packet::), used for binary downloads, may include an unescaped ‘0x03’ as part of its d52154 1 a52154 1 ‘BREAK’ followed by ‘g’ is also known as Magic SysRq g. When Linux d52162 1 a52162 1 packet framing instead of the single byte ‘0x03’. d52182 1 a52182 1 The GDB remote serial protocol includes “notifications”, packets that d52189 1 a52189 1 A notification packet has the form ‘% DATA # CHECKSUM’, where DATA is d52192 2 a52193 2 DATA never contains ‘$’, ‘%’ or ‘#’ characters. Upon receiving a notification, the recipient sends no ‘+’ or ‘-’ to acknowledge the d52210 1 a52210 1 (Older versions of GDB ignore bytes received until they see the ‘$’ d52217 1 a52217 1 ‘NAME:EVENT’ d52222 1 a52222 1 ‘ACK’ d52240 1 a52240 1 synchronous response or a ‘+’/‘-’ acknowledgment to a packet it has d52257 1 a52257 1 to report, the stub shall return an ‘OK’ response. At this point, GDB d52260 1 a52260 1 the final ‘OK’ is received . If further notification events occur, the d52297 2 a52298 2 non-stop mode, it should report that to GDB by including ‘QNonStop+’ in its ‘qSupported’ response (*note qSupported::). d52300 1 a52300 1 GDB typically sends a ‘QNonStop’ packet only when establishing a new d52304 1 a52304 1 GDB uses the ‘?’ packet as necessary to probe the target state after a d52312 2 a52313 2 reporting the stop event is stopped. That is, when reporting a ‘S’ or ‘T’ response to indicate completion of a step operation, hitting a d52315 1 a52315 1 still-running threads continue to run. When reporting a ‘W’ or ‘X’ d52319 2 a52320 2 In non-stop mode, the target shall respond to the ‘?’ packet as follows. First, any incomplete stop reply notification/‘vStopped’ d52324 2 a52325 2 as a synchronous reply to the ‘?’ packet, and subsequent stop replies are sent as responses to ‘vStopped’ packets using the mechanism d52328 2 a52329 2 running when the target receives the ‘?’ packet, or if the target is not attached to any process, it shall respond ‘OK’. d52332 2 a52333 2 ‘swbreak’ stop reason if software breakpoints are supported, and the ‘hwbreak’ stop reason if hardware breakpoints are supported (*note d52340 1 a52340 1 should be reported to the user. Note the ‘swbreak’ feature implies that d52351 2 a52352 2 packet, the first response expected is an acknowledgment: either ‘+’ (to indicate the package was received correctly) or ‘-’ (to request d52357 1 a52357 1 pipe or TCP connection), the ‘+’/‘-’ acknowledgments are redundant. It d52360 1 a52360 1 the ‘QStartNoAckMode’ packet; *note QStartNoAckMode::. d52363 1 a52363 1 or expect ‘+’/‘-’ protocol acknowledgments. The packet and response d52367 1 a52367 1 If the stub supports ‘QStartNoAckMode’ and prefers to operate in d52369 4 a52372 4 ‘QStartNoAckMode+’ in its response to ‘qSupported’; *note qSupported::. If GDB also supports ‘QStartNoAckMode’ and it has not been disabled via the ‘set remote noack-packet off’ command (*note Remote Configuration::), GDB may then send a ‘QStartNoAckMode’ packet to the d52374 1 a52374 1 GDB sends a final ‘+’ acknowledgment of the stub's ‘OK’ response, which d52377 1 a52377 1 Note that ‘set remote noack-packet’ command only affects negotiation d52380 1 a52380 1 Since ‘+’/‘-’ acknowledgments are enabled by default when a new d52440 1 a52440 1 The “File I/O remote protocol extension” (short: File-I/O) allows the d52454 1 a52454 1 when GDB is waiting for a response from the ‘C’, ‘c’, ‘S’ or ‘s’ d52458 1 a52458 1 is possible to interrupt File-I/O by a user interrupt (‘Ctrl-C’) within d52462 1 a52462 1 the latest ‘C’, ‘c’, ‘S’ or ‘s’ action. That means, after finishing the d52487 1 a52487 1 The File-I/O protocol uses the ‘F’ packet as the request as well as d52491 1 a52491 1 previous ‘C’, ‘c’, ‘S’ or ‘s’ packet. This ‘F’ packet contains all d52495 1 a52495 1 • A unique identifier for the requested system call. d52497 1 a52497 1 • All parameters to the system call. Pointers are given as addresses d52505 1 a52505 1 • If the parameters include pointer values to data needed as input to d52507 1 a52507 1 standard ‘m’ packet request. This additional communication has to d52509 1 a52509 1 other ‘m’ packet. d52511 1 a52511 1 • GDB translates all value from protocol representation to host d52515 1 a52515 1 • GDB calls the system call. d52517 1 a52517 1 • It then coerces datatypes back to protocol representation. d52519 1 a52519 1 • If the system call is expected to return data in buffer space d52521 1 a52521 1 transmitted to the target using a ‘M’ or ‘X’ packet. This packet d52523 1 a52523 1 any other ‘M’ or ‘X’ packet. d52525 1 a52525 1 Eventually GDB replies with another ‘F’ packet which contains all d52529 1 a52529 1 • Return value. d52531 1 a52531 1 • ‘errno’, if has been changed by the system call. d52533 1 a52533 1 • "Ctrl-C" flag. d52541 1 a52541 1 E.14.3 The ‘F’ Request Packet d52544 1 a52544 1 The ‘F’ request packet has the following format: d52546 1 a52546 1 ‘FCALL-ID,PARAMETER...’ d52563 1 a52563 1 E.14.4 The ‘F’ Reply Packet d52566 1 a52566 1 The ‘F’ reply packet has the following format: d52568 1 a52568 1 ‘FRETCODE,ERRNO,CTRL-C FLAG;CALL-SPECIFIC ATTACHMENT’ d52572 1 a52572 1 ERRNO is the ‘errno’ set by the call, in protocol-specific d52578 1 a52578 1 The CTRL-C FLAG itself consists of the character ‘C’: d52587 1 a52587 1 assuming 4 is the protocol-specific representation of ‘EINTR’. d52592 1 a52592 1 E.14.5 The ‘Ctrl-C’ Message d52595 1 a52595 1 If the ‘Ctrl-C’ flag is set in the GDB reply packet (*note The F Reply d52597 1 a52597 1 The meaning for the target is "system call interrupted by ‘SIGINT’". d52599 1 a52599 1 and return to GDB with a ‘T02’ packet. d52604 1 a52604 1 • The system call hasn't been performed on the host yet. d52606 1 a52606 1 • The system call on the host has been finished. d52609 1 a52609 1 the returned ‘errno’. If it's the protocol representation of ‘EINTR’, d52611 1 a52611 1 ‘EINTR’ handling on POSIX systems. In any other case, the target may d52617 1 a52617 1 yet, GDB may send the ‘F’ reply immediately, setting ‘EINTR’ as ‘errno’ d52620 1 a52620 1 This requires sending ‘M’ or ‘X’ packets as necessary. The ‘F’ packet d52632 2 a52633 2 GDB console is handled as any other file output operation (‘write(1, ...)’ or ‘write(2, ...)’). Console input is handled by GDB so that d52637 2 a52638 2 • The user types ‘Ctrl-c’. The behaviour is as explained above, and the ‘read’ system call is treated as finished. d52640 1 a52640 1 • The user presses . This is treated as end of input with a d52643 2 a52644 2 • The user types ‘Ctrl-d’. This is treated as end of input. No trailing character (neither newline nor ‘Ctrl-D’) is appended to d52648 2 a52649 2 the ‘read’ call, the trailing characters are buffered in GDB until either another ‘read(0, ...)’ is requested by the target, or debugging d52683 1 a52683 1 ‘Fopen,PATHPTR/LEN,FLAGS,MODE’ d52685 1 a52685 1 FLAGS is the bitwise ‘OR’ of the following values: d52687 1 a52687 1 ‘O_CREAT’ d52691 2 a52692 2 ‘O_EXCL’ When used with ‘O_CREAT’, if the file already exists it is an d52695 1 a52695 1 ‘O_TRUNC’ d52697 1 a52697 1 (‘O_RDWR’ or ‘O_WRONLY’ is given) it will be truncated to zero d52700 1 a52700 1 ‘O_APPEND’ d52703 1 a52703 1 ‘O_RDONLY’ d52706 1 a52706 1 ‘O_WRONLY’ d52709 1 a52709 1 ‘O_RDWR’ d52714 1 a52714 1 MODE is the bitwise ‘OR’ of the following values: d52716 1 a52716 1 ‘S_IRUSR’ d52719 1 a52719 1 ‘S_IWUSR’ d52722 1 a52722 1 ‘S_IRGRP’ d52725 1 a52725 1 ‘S_IWGRP’ d52728 1 a52728 1 ‘S_IROTH’ d52731 1 a52731 1 ‘S_IWOTH’ d52737 1 a52737 1 ‘open’ returns the new file descriptor or -1 if an error occurred. d52741 2 a52742 2 ‘EEXIST’ PATHNAME already exists and ‘O_CREAT’ and ‘O_EXCL’ were used. d52744 1 a52744 1 ‘EISDIR’ d52747 1 a52747 1 ‘EACCES’ d52750 1 a52750 1 ‘ENAMETOOLONG’ d52753 1 a52753 1 ‘ENOENT’ d52756 1 a52756 1 ‘ENODEV’ d52759 1 a52759 1 ‘EROFS’ d52763 1 a52763 1 ‘EFAULT’ d52766 1 a52766 1 ‘ENOSPC’ d52769 1 a52769 1 ‘EMFILE’ d52772 1 a52772 1 ‘ENFILE’ d52776 1 a52776 1 ‘EINTR’ d52789 1 a52789 1 ‘Fclose,FD’ d52792 1 a52792 1 ‘close’ returns zero on success, or -1 if an error occurred. d52796 1 a52796 1 ‘EBADF’ d52799 1 a52799 1 ‘EINTR’ d52812 1 a52812 1 ‘Fread,FD,BUFPTR,COUNT’ d52821 1 a52821 1 ‘EBADF’ d52824 1 a52824 1 ‘EFAULT’ d52827 1 a52827 1 ‘EINTR’ d52840 1 a52840 1 ‘Fwrite,FD,BUFPTR,COUNT’ d52848 1 a52848 1 ‘EBADF’ d52851 1 a52851 1 ‘EFAULT’ d52854 1 a52854 1 ‘EFBIG’ d52858 1 a52858 1 ‘ENOSPC’ d52861 1 a52861 1 ‘EINTR’ d52874 1 a52874 1 ‘Flseek,FD,OFFSET,FLAG’ d52878 1 a52878 1 ‘SEEK_SET’ d52881 1 a52881 1 ‘SEEK_CUR’ d52884 1 a52884 1 ‘SEEK_END’ d52894 1 a52894 1 ‘EBADF’ d52897 1 a52897 1 ‘ESPIPE’ d52900 1 a52900 1 ‘EINVAL’ d52903 1 a52903 1 ‘EINTR’ d52916 1 a52916 1 ‘Frename,OLDPATHPTR/LEN,NEWPATHPTR/LEN’ d52923 1 a52923 1 ‘EISDIR’ d52927 1 a52927 1 ‘EEXIST’ d52930 1 a52930 1 ‘EBUSY’ d52934 1 a52934 1 ‘EINVAL’ d52938 1 a52938 1 ‘ENOTDIR’ d52943 1 a52943 1 ‘EFAULT’ d52946 1 a52946 1 ‘EACCES’ d52949 1 a52949 1 ‘ENAMETOOLONG’ d52953 1 a52953 1 ‘ENOENT’ d52956 1 a52956 1 ‘EROFS’ d52959 1 a52959 1 ‘ENOSPC’ d52963 1 a52963 1 ‘EINTR’ d52976 1 a52976 1 ‘Funlink,PATHNAMEPTR/LEN’ d52983 1 a52983 1 ‘EACCES’ d52986 1 a52986 1 ‘EPERM’ d52989 1 a52989 1 ‘EBUSY’ d52993 1 a52993 1 ‘EFAULT’ d52996 1 a52996 1 ‘ENAMETOOLONG’ d52999 1 a52999 1 ‘ENOENT’ d53002 1 a53002 1 ‘ENOTDIR’ d53005 1 a53005 1 ‘EROFS’ d53008 1 a53008 1 ‘EINTR’ d53022 2 a53023 2 ‘Fstat,PATHNAMEPTR/LEN,BUFPTR’ ‘Ffstat,FD,BUFPTR’ d53030 1 a53030 1 ‘EBADF’ d53033 1 a53033 1 ‘ENOENT’ d53037 1 a53037 1 ‘ENOTDIR’ d53040 1 a53040 1 ‘EFAULT’ d53043 1 a53043 1 ‘EACCES’ d53046 1 a53046 1 ‘ENAMETOOLONG’ d53049 1 a53049 1 ‘EINTR’ d53062 1 a53062 1 ‘Fgettimeofday,TVPTR,TZPTR’ d53069 1 a53069 1 ‘EINVAL’ d53072 1 a53072 1 ‘EFAULT’ d53085 1 a53085 1 ‘Fisatty,FD’ d53092 1 a53092 1 ‘EINTR’ d53095 1 a53095 1 Note that the ‘isatty’ call is treated as a special case: it returns d53098 1 a53098 1 ‘ioctl’ and would be more complex than needed. d53110 1 a53110 1 ‘Fsystem,COMMANDPTR/LEN’ d53117 2 a53118 2 command is returned, which is extracted from the host's ‘system’ return value by calling ‘WEXITSTATUS(retval)’. In case ‘/bin/sh’ d53123 1 a53123 1 ‘EINTR’ d53127 1 a53127 1 perform the ‘system’ call. The return value of ‘system’ on the host is d53132 3 a53134 3 Due to security concerns, the ‘system’ call is by default refused by GDB. The user has to allow this call explicitly with the ‘set remote system-call-allowed 1’ command. d53136 2 a53137 2 ‘set remote system-call-allowed’ Control whether to allow the ‘system’ calls in the File I/O d53140 2 a53141 2 ‘show remote system-call-allowed’ Show whether the ‘system’ calls are allowed in the File I/O d53164 2 a53165 2 The integral datatypes used in the system calls are ‘int’, ‘unsigned int’, ‘long’, ‘unsigned long’, ‘mode_t’, and ‘time_t’. d53167 1 a53167 1 ‘int’, ‘unsigned int’, ‘mode_t’ and ‘time_t’ are implemented as 32 d53170 1 a53170 1 ‘long’ and ‘unsigned long’ are implemented as 64 bit types. d53173 1 a53173 1 those in ‘limits.h’) to allow range checking on host and target. d53175 1 a53175 1 ‘time_t’ datatypes are defined as seconds since the Epoch. d53178 1 a53178 1 of a structured datatype e.g. a ‘struct stat’ have to be given in big d53196 1 a53196 1 trailing null byte. For example, the string ‘"hello world"’ at address d53208 1 a53208 1 example, a ‘struct stat’) is expected to be in a protocol-specific d53211 1 a53211 1 before the ‘F’ packet is sent, and by GDB before it transfers memory to d53221 1 a53221 1 The buffer of type ‘struct stat’ used by the target and GDB is defined d53247 1 a53247 1 ‘st_dev’ d53250 1 a53250 1 ‘st_ino’ d53253 1 a53253 1 ‘st_mode’ d53257 3 a53259 3 ‘st_uid’ ‘st_gid’ ‘st_rdev’ d53262 3 a53264 3 ‘st_atime’ ‘st_mtime’ ‘st_ctime’ d53269 1 a53269 1 The target gets a ‘struct stat’ of the above representation and is d53274 1 a53274 1 protocol representations of ‘struct stat’ members, these members could d53283 1 a53283 1 The buffer of type ‘struct timeval’ used by the File-I/O protocol is d53378 1 a53378 1 ‘EUNKNOWN’ is used as a fallback error value if a host system returns d53432 1 a53432 1 invalid file descriptor (‘EBADF’): d53437 1 a53437 1 Example sequence of a read call, user presses ‘Ctrl-c’ before syscall d53444 1 a53444 1 Example sequence of a read call, user presses ‘Ctrl-c’ after syscall d53457 1 a53457 1 On some platforms, a dynamic loader (e.g. ‘ld.so’) runs in the same d53463 1 a53463 1 ‘qXfer:libraries:read’ packet (*note qXfer library list read::) instead. d53467 1 a53467 1 The ‘qXfer:libraries:read’ packet returns an XML document which lists d53525 1 a53525 1 ‘ld.so’) and normal memory operations to maintain a list of shared d53529 1 a53529 1 The ‘qXfer:libraries-svr4:read’ packet returns an XML document which d53533 3 a53535 3 − ‘name’, the absolute file name from the ‘l_name’ field of ‘struct link_map’. − ‘lm’ with address of ‘struct link_map’ used for TLS (Thread Local d53537 2 a53538 2 − ‘l_addr’, the displacement as read from the field ‘l_addr’ of ‘struct link_map’. For prelinked libraries this is not an absolute d53541 3 a53543 3 − ‘l_ld’, which is memory address of the ‘PT_DYNAMIC’ segment − ‘lmid’, which is an identifier for a linker namespace, such as the memory address of the ‘r_debug’ object that contains this d53545 1 a53545 1 ‘dlinfo (3)’. d53547 2 a53548 2 Additionally the single ‘main-lm’ attribute specifies address of ‘struct link_map’ used for the main executable. This parameter is used d53586 1 a53586 1 The memory map is obtained using the ‘qXfer:memory-map:read’ (*note d53605 1 a53605 1 • A region of RAM starting at ADDR and extending for LENGTH bytes d53610 1 a53610 1 • A region of read-only memory: d53614 1 a53614 1 • A region of flash memory, with erasure blocks BLOCKSIZE bytes in d53622 1 a53622 1 covered by the memory map are RAM, and uses the ordinary ‘M’ and ‘X’ d53652 1 a53652 1 issues the ‘qXfer:threads:read’ packet (*note qXfer threads read::) and d53662 2 a53663 2 Each ‘thread’ element must have the ‘id’ attribute that identifies the thread (*note thread-id syntax::). The ‘core’ attribute, if d53665 3 a53667 3 on. The ‘name’ attribute, if present, specifies the human-readable name of the thread. The content of the of ‘thread’ element is interpreted as human-readable auxiliary information. The ‘handle’ attribute, if d53681 1 a53681 1 This list is obtained using the ‘qXfer:traceframe-info:read’ (*note d53699 1 a53699 1 • A region of collected memory starting at ADDR and extending for d53704 1 a53704 1 • A block indicating trace state variable numbered NUMBER has been d53731 1 a53731 1 This list is obtained using the ‘qXfer:btrace:read’ (*note qXfer d53747 1 a53747 1 • A block of sequentially executed instructions starting at BEGIN and d53780 1 a53780 1 using the ‘qXfer:btrace-conf:read’ (*note qXfer btrace-conf read::) d53786 3 a53788 3 ‘bts’ This thread uses the “Branch Trace Store” (BTS) format. ‘size’ d53790 3 a53792 3 ‘pt’ This thread uses the “Intel Processor Trace” (Intel PT) format. ‘size’ d53823 1 a53823 1 Using GDB's ‘trace’ and ‘collect’ commands, the user can specify d53825 1 a53825 1 those locations are reached. Later, using the ‘tfind’ command, she can d53834 1 a53834 1 When GDB is debugging a remote target, the GDB “agent” code running d53868 2 a53869 2 instruction is one byte long (thus the term “bytecode”). Some instructions are followed by operand bytes; for example, the ‘goto’ d53886 1 a53886 1 where ‘LONGEST’ and ‘DOUBLEST’ are ‘typedef’ names for the largest d53891 1 a53891 1 the stack. For tracing applications, ‘trace’ bytecodes in the d53897 1 a53897 1 ‘pc’ d53900 1 a53900 1 ‘start’ d53902 1 a53902 1 interpreting the ‘goto’ and ‘if_goto’ instructions. d53918 1 a53918 1 memory reference instructions (‘ref’N) d53921 1 a53921 1 full-size integers. They may need to be sign-extended; the ‘ext’ d53924 1 a53924 1 the sign-extension instruction (‘ext’ N) d53937 3 a53939 3 instructions; for example, the expression ‘x + y * z’ would typically produce code like the following, assuming that ‘x’ and ‘y’ live in registers, and ‘z’ is a global variable holding a 32-bit ‘int’: d53951 2 a53952 2 ‘reg 1’ Push the value of register 1 (presumably holding ‘x’) onto the d53955 2 a53956 2 ‘reg 2’ Push the value of register 2 (holding ‘y’). d53958 2 a53959 2 ‘const32 address of z’ Push the address of ‘z’ onto the stack. d53961 1 a53961 1 ‘ref32’ d53964 1 a53964 1 the address of ‘z’ with ‘z’'s value. d53966 1 a53966 1 ‘ext 32’ d53968 1 a53968 1 length. This is necessary because ‘z’ is a signed integer. d53970 1 a53970 1 ‘mul’ d53973 1 a53973 1 expression ‘y * z’. d53975 1 a53975 1 ‘add’ d53977 1 a53977 1 of the stack contains the value of ‘x + y * z’. d53979 1 a53979 1 ‘end’ d53991 1 a53991 1 ‘add’ (0x02): A B ⇒ A+B d53996 1 a53996 1 In this example, ‘add’ is the name of the bytecode, and ‘(0x02)’ is d53998 1 a53998 1 phrase "A B ⇒ A+B" shows the stack before and after the bytecode d54008 1 a54008 1 ‘const8’ (0x22) N: ⇒ N d54012 2 a54013 2 In this example, the bytecode ‘const8’ takes an operand N directly from the bytecode stream; the operand follows the ‘const8’ bytecode d54018 2 a54019 2 For the ‘const8’ bytecode, there are no stack items given before the ⇒; this simply means that the bytecode consumes no values from the d54021 1 a54021 1 list on either side of the ⇒ may be empty. d54032 1 a54032 1 ‘float’ (0x01): ⇒ d54036 1 a54036 1 ‘add’ (0x02): A B ⇒ A+B d54039 1 a54039 1 ‘sub’ (0x03): A B ⇒ A-B d54043 1 a54043 1 ‘mul’ (0x04): A B ⇒ A*B d54049 1 a54049 1 ‘div_signed’ (0x05): A B ⇒ A/B d54054 1 a54054 1 ‘div_unsigned’ (0x06): A B ⇒ A/B d54059 1 a54059 1 ‘rem_signed’ (0x07): A B ⇒ A MODULO B d54064 1 a54064 1 ‘rem_unsigned’ (0x08): A B ⇒ A MODULO B d54069 1 a54069 1 ‘lsh’ (0x09): A B ⇒ A<>B d54079 1 a54079 1 ‘rsh_unsigned’ (0x0b): A B ⇒ A>>B d54084 1 a54084 1 ‘log_not’ (0x0e): A ⇒ !A d54088 2 a54089 2 ‘bit_and’ (0x0f): A B ⇒ A&B Pop two integers from the stack, and push their bitwise ‘and’. d54091 2 a54092 2 ‘bit_or’ (0x10): A B ⇒ A|B Pop two integers from the stack, and push their bitwise ‘or’. d54094 1 a54094 1 ‘bit_xor’ (0x11): A B ⇒ A^B d54096 1 a54096 1 exclusive-‘or’. d54098 1 a54098 1 ‘bit_not’ (0x12): A ⇒ ~A d54101 1 a54101 1 ‘equal’ (0x13): A B ⇒ A=B d54105 1 a54105 1 ‘less_signed’ (0x14): A B ⇒ A A A d54157 1 a54157 1 ‘swap’ (0x2b): A B => B A d54160 1 a54160 1 ‘pop’ (0x29): A => d54163 1 a54163 1 ‘pick’ (0x32) N: A ... B => A ... B A d54166 1 a54166 1 is zero, this is the same as ‘dup’; if N is one, it copies the item d54170 1 a54170 1 ‘rot’ (0x33): A B C => C A B d54175 1 a54175 1 ‘if_goto’ (0x20) OFFSET: A ⇒ d54179 1 a54179 1 non-zero, set the ‘pc’ register to ‘start’ + OFFSET. Thus, an d54183 1 a54183 1 immediately following the ‘if_goto’ bytecode. It is always stored d54190 10 a54199 10 ‘goto’ (0x21) OFFSET: ⇒ Branch unconditionally to OFFSET; in other words, set the ‘pc’ register to ‘start’ + OFFSET. The offset is stored in the same way as for the ‘if_goto’ bytecode. ‘const8’ (0x22) N: ⇒ N ‘const16’ (0x23) N: ⇒ N ‘const32’ (0x24) N: ⇒ N ‘const64’ (0x25) N: ⇒ N d54202 1 a54202 1 value, and then sign-extend it using the ‘ext’ bytecode. d54205 1 a54205 1 following the ‘const’B bytecode. The constant N is always stored d54212 1 a54212 1 ‘reg’ (0x26) N: ⇒ A d54217 1 a54217 1 immediately following the ‘reg’ bytecode. It is always stored most d54224 1 a54224 1 ‘getv’ (0x2c) N: ⇒ V d54229 1 a54229 1 immediately following the ‘getv’ bytecode. It is always stored d54236 1 a54236 1 ‘setv’ (0x2d) N: V ⇒ V d54240 1 a54240 1 handling of N is as described for ‘getv’. d54242 1 a54242 1 ‘trace’ (0x0c): ADDR SIZE ⇒ d54246 1 a54246 1 ‘trace_quick’ (0x0d) SIZE: ADDR ⇒ ADDR d54249 1 a54249 1 following the ‘trace’ opcode. d54251 2 a54252 2 This bytecode is equivalent to the sequence ‘dup const8 SIZE trace’, but we provide it anyway to save space in bytecode strings. d54254 1 a54254 1 ‘trace16’ (0x30) SIZE: ADDR ⇒ ADDR d54257 1 a54257 1 been named ‘trace_quick16’, for consistency. d54259 1 a54259 1 ‘tracev’ (0x2e) N: ⇒ A d54261 1 a54261 1 buffer. The handling of N is as described for ‘getv’. d54263 1 a54263 1 ‘tracenz’ (0x2f) ADDR SIZE ⇒ d54268 2 a54269 2 ‘printf’ (0x34) NUMARGS STRING ⇒ Do a formatted print, in the style of the C function ‘printf’). d54275 1 a54275 1 ‘"\t%d\n"’ is six characters long, and the output will consist of a d54280 1 a54280 1 as a first argument, as with the C function ‘fprintf’. If the d54285 1 a54285 1 ‘end’ (0x27): ⇒ d54309 1 a54309 1 in addition to bytecodes that do the calculation, GDB adds ‘trace’ d54312 1 a54312 1 • The user selects trace points in the program's code at which GDB d54315 1 a54315 1 • The user specifies expressions to evaluate at each trace point. d54320 1 a54320 1 • GDB transmits the tracepoints and their associated expressions to d54323 1 a54323 1 • The agent arranges to be notified when a trace point is hit. d54325 1 a54325 1 • When execution on the target reaches a trace point, the agent d54329 1 a54329 1 • Later, when the user selects a given trace event and inspects the d54342 1 a54342 1 have to deal with ‘long long’ operations. Also, different targets will d54353 1 a54353 1 • whether floating point is supported d54355 1 a54355 1 • whether ‘long long’ is supported d54357 1 a54357 1 • maximum acceptable size of bytecode stack d54359 1 a54359 1 • maximum acceptable length of bytecode expressions d54361 1 a54361 1 • which registers are actually available for collection d54363 1 a54363 1 • whether the target supports disabled tracepoints d54401 1 a54401 1 Why don't you have ‘>’ or ‘<=’ operators? d54403 1 a54403 1 can combine the ‘less_’ opcodes with ‘log_not’, and swap the order d54405 2 a54406 2 operators. For example, ‘(x <= y)’ is ‘! (x > y)’, which is ‘! (y < x)’. d54408 3 a54410 3 Why do you have ‘log_not’? Why do you have ‘ext’? Why do you have ‘zero_ext’? d54415 1 a54415 1 ‘log_not’ is equivalent to ‘const8 0 equal’; it's used in half the d54418 2 a54419 2 ‘ext N’ is equivalent to ‘const8 S-N lsh const8 S-N rsh_signed’, where S is the size of the stack elements; it follows ‘refM’ and d54423 1 a54423 1 ‘zero_ext N’ is equivalent to ‘constM MASK log_and’; it's used d54427 7 a54433 7 Why not have sign-extending variants of the ‘ref’ operators? Because that would double the number of ‘ref’ operators, and we need the ‘ext’ bytecode anyway for accessing bitfields. Why not have constant-address variants of the ‘ref’ operators? Because that would double the number of ‘ref’ operators again, and ‘const32 ADDRESS ref32’ is only one byte longer. d54435 1 a54435 1 Why do the ‘refN’ operators have to support unaligned fetches? d54458 1 a54458 1 Why aren't the ‘goto’ ops PC-relative? d54462 1 a54462 1 Why is there only one offset size for the ‘goto’ ops? d54485 1 a54485 1 Why does the ‘reg’ bytecode take a 16-bit register number? d54491 1 a54491 1 Why do we need ‘trace’ and ‘trace_quick’? d54494 2 a54495 2 ‘x->y->z’, the agent must record the values of ‘x’ and ‘x->y’ as well as the value of ‘x->y->z’. d54497 1 a54497 1 Don't the ‘trace’ bytecodes make the interpreter less general? d54500 1 a54500 1 purpose. If an expression doesn't use the ‘trace’ bytecodes, they d54503 1 a54503 1 Why doesn't ‘trace_quick’ consume its arguments the way everything else does? d54506 3 a54508 3 rearrangement necessary. However, ‘trace_quick’ is a kludge to save space; it only exists so we needn't write ‘dup const8 SIZE trace’ before every memory reference. Therefore, it's okay for it d54513 1 a54513 1 Why does ‘trace16’ exist? d54516 2 a54517 2 objects that large will be quite rare, so it is okay to use ‘dup const16 SIZE trace’ in those cases. d54519 1 a54519 1 Whatever we decide to do with ‘trace16’, we should at least leave d54537 1 a54537 1 • With so many different customized processors, it is difficult for d54539 1 a54539 1 • Since individual variants may have short lifetimes or limited d54542 1 a54542 1 • When GDB does support the architecture of the embedded system at d54544 1 a54544 1 ‘set architecture’ command can be error-prone. d54573 3 a54575 3 using ‘qXfer’ requests (*note qXfer: General Query Packets.). The ANNEX in the ‘qXfer’ packet will be ‘target.xml’. The contents of the ‘target.xml’ annex are an XML document, of the form described in *note d54582 1 a54582 1 ‘set tdesc filename PATH’ d54585 1 a54585 1 ‘unset tdesc filename’ d54589 1 a54589 1 ‘show tdesc filename’ d54600 2 a54601 2 sources in ‘gdb/features/gdb-target.dtd’. This means you can use generally available tools like ‘xmllint’ to check that your feature d54638 1 a54638 1 ‘version’ attribute for ‘’ may also be omitted, but we recommend d54640 1 a54640 1 ‘gdb-target.dtd’, they will detect and report the version mismatch. d54655 1 a54655 1 that document. If the current description was read using ‘qXfer’, then d54664 1 a54664 1 An ‘’ element has this form: d54668 2 a54669 2 ARCH is one of the architectures from the set accepted by ‘set architecture’ (*note Specifying a Debugging Target: Targets.). d54677 1 a54677 1 An ‘’ element has this form: d54682 1 a54682 1 ‘set osabi’ (*note Configuring the Current ABI: ABI.). d54690 1 a54690 1 A ‘’ element has this form: d54694 2 a54695 2 ARCH is one of the architectures from the set accepted by ‘set architecture’ (*note Specifying a Debugging Target: Targets.). d54697 1 a54697 1 A ‘’ element is used to specify that the target is able d54699 4 a54702 4 the ‘’ element. For example, on the Cell Broadband Engine, the main architecture is ‘powerpc:common’ or ‘powerpc:common64’, but the system is able to run binaries in the ‘spu’ architecture as well. The way to describe this capability with ‘’ is as d54711 1 a54711 1 Each ‘’ describes some logical portion of the target system. d54713 1 a54713 1 types of their contents. A ‘’ element has this form: d54734 2 a54735 2 Each type element must have an ‘id’ attribute, which gives a unique (within the containing ‘’) name to the type. Types must be d54739 1 a54739 1 of scalar elements. These types are written as ‘’ elements, d54746 2 a54747 2 with a union type containing the useful representations. The ‘’ element contains one or more ‘’ elements, each of which has a d54784 1 a54784 1 empty string, ‘""’, in which case the field is "filler" and its value is d54792 1 a54792 1 The default value of TYPE is ‘bool’ for single bit fields, and an d54797 2 a54798 2 Registers defined with ‘flags’ have these advantages over defining them with ‘struct’: d54800 2 a54801 2 • Arithmetic may be performed on them as if they were integers. • They are printed in a more readable fashion. d54803 2 a54804 2 Registers defined with ‘struct’ have one advantage over defining them with ‘flags’: d54806 1 a54806 1 • One can fetch individual fields like in ‘C’. d54837 2 a54838 2 to read or write the register; e.g. it is used in the remote ‘p’ and ‘P’ packets, and registers appear in the ‘g’ and ‘G’ packets in d54843 1 a54843 1 calls; this must be either ‘yes’ or ‘no’. The default is ‘yes’, d54849 3 a54851 3 defined in the current feature, or one of the special types ‘int’ and ‘float’. ‘int’ is an integer type of the correct size for BITSIZE, and ‘float’ is a floating point type (in the d54853 1 a54853 1 for BITSIZE. The default is ‘int’. d54857 1 a54857 1 of the standard register groups ‘general’, ‘float’, ‘vector’ or an d54860 3 a54862 3 may be separated by hyphens; e.g. ‘special-group’ or ‘ultra-special-group’. If no GROUP is specified, GDB will not display the register in ‘info registers’. d54875 1 a54875 1 ‘bool’ d54878 6 a54883 6 ‘int8’ ‘int16’ ‘int24’ ‘int32’ ‘int64’ ‘int128’ d54886 6 a54891 6 ‘uint8’ ‘uint16’ ‘uint24’ ‘uint32’ ‘uint64’ ‘uint128’ d54894 2 a54895 2 ‘code_ptr’ ‘data_ptr’ d54902 1 a54902 1 ‘ieee_half’ d54905 1 a54905 1 ‘ieee_single’ d54908 1 a54908 1 ‘ieee_double’ d54911 2 a54912 2 ‘bfloat16’ The 16-bit “brain floating point” format used e.g. by x86 and ARM. d54914 1 a54914 1 ‘arm_fpa_ext’ d54917 1 a54917 1 ‘i387_ext’ d54920 1 a54920 1 ‘i386_eflags’ d54923 1 a54923 1 ‘i386_mxcsr’ d54932 1 a54932 1 Enum target types are useful in ‘struct’ and ‘flags’ register d54954 1 a54954 1 Given that description, a value of 3 for the ‘flags’ register would d54983 1 a54983 1 tree, in the directory ‘gdb/features’. d54988 1 a54988 1 registers is named ‘org.gnu.gdb.arm.core’. d55023 1 a55023 1 The ‘org.gnu.gdb.aarch64.core’ feature is required for AArch64 targets. d55026 8 a55033 8 − ‘x0’ through ‘x30’, the general purpose registers, with size of 64 bits. Register ‘x30’ is also known as the “link register”, or ‘lr’. − ‘sp’, the stack pointer register or ‘x31’. It is 64 bits in size and has a type of ‘data_ptr’. − ‘pc’, the program counter register. It is 64 bits in size and has a type of ‘code_ptr’. − ‘cpsr’, the current program status register. It is 32 bits in size d55036 1 a55036 1 The semantics of the individual flags and fields in ‘cpsr’ can change d55046 1 a55046 1 The ‘org.gnu.gdb.aarch64.fpu’ feature is optional. If present, it must d55049 1 a55049 1 − ‘v0’ through ‘v31’, the vector registers with size of 128 bits. d55051 1 a55051 1 − ‘fpsr’, the floating-point status register. It is 32 bits in size d55053 1 a55053 1 − ‘fpcr’, the floating-point control register. It is 32 bits in size d55056 1 a55056 1 The semantics of the individual flags and fields in ‘fpsr’ and ‘fpcr’ d55059 1 a55059 1 The types for the vector registers, ‘fpsr’ and ‘fpcr’ registers can d55068 1 a55068 1 The ‘org.gnu.gdb.aarch64.sve’ feature is optional. If present, it means d55072 1 a55072 1 − ‘z0’ through ‘z31’, the scalable vector registers. Their sizes are d55076 1 a55076 1 − ‘fpsr’, the floating-point status register. It is 32 bits in size d55078 1 a55078 1 − ‘fpcr’, the floating-point control register. It is 32 bits in size d55080 1 a55080 1 − ‘p0’ through ‘p15’, the predicate registers. Their sizes are d55084 1 a55084 1 − ‘ffr’, the First Fault register. It has a variable size based on d55087 3 a55089 3 − ‘vg’, the vector granule. It represents the number of 64 bits chunks in a ‘z’ register. It is closely associated with the current vector length. It has a type of ‘int’. d55092 2 a55093 2 Extension is supported, and will adjust the sizes of the ‘z’, ‘p’ and ‘ffr’ registers accordingly, based on the value of ‘vg’. d55095 2 a55096 2 GDB will also create pseudo-registers equivalent to the ‘v’ vector registers from the ‘org.gnu.gdb.aarch64.fpu’ feature. d55098 2 a55099 2 The first 128 bits of the ‘z’ registers overlap the 128 bits of the ‘v’ registers, so changing one will trigger a change to the other. d55101 1 a55101 1 For the types of the ‘z’, ‘p’ and ‘ffr’ registers, please check the d55105 1 a55105 1 The semantics of the individual flags and fields in ‘fpsr’ and ‘fpcr’ d55108 1 a55108 1 The types for the ‘fpsr’ and ‘fpcr’ registers can be found in the d55118 1 a55118 1 The ‘org.gnu.gdb.aarch64.pauth’ optional feature was introduced so GDB d55124 1 a55124 1 − ‘pauth_dmask’, the user-mode pointer authentication mask for data d55126 1 a55126 1 − ‘pauth_cmask’, the user-mode pointer authentication mask for code d55131 1 a55131 1 − ‘pauth_dmask’, the user-mode pointer authentication mask for data d55133 1 a55133 1 − ‘pauth_cmask’, the user-mode pointer authentication mask for code d55135 1 a55135 1 − ‘pauth_dmask_high’, the kernel-mode pointer authentication mask for d55137 1 a55137 1 − ‘pauth_cmask_high’, the kernel-mode pointer authentication mask for d55142 1 a55142 1 decorate backtraces with a ‘[PAC]’ marker alongside a function that has d55150 1 a55150 1 Please note the ‘org.gnu.gdb.aarch64.pauth’ feature string is d55152 1 a55152 1 releases of GDB and ‘gdbserver’. Targets that support Pointer d55154 1 a55154 1 ‘org.gnu.gdb.aarch64.pauth_v2’ feature string instead. d55156 2 a55157 2 The ‘org.gnu.gdb.aarch64.pauth_v2’ feature has the exact same contents as feature ‘org.gnu.gdb.aarch64.pauth’. d55159 1 a55159 1 The reason for having feature ‘org.gnu.gdb.aarch64.pauth_v2’ is a bug d55162 1 a55162 1 Authentication (using feature string ‘org.gnu.gdb.aarch64.pauth’) and d55169 1 a55169 1 Authentication support via the ‘org.gnu.gdb.aarch64.pauth’ feature d55176 1 a55176 1 The ‘org.gnu.gdb.aarch64.tls’ optional feature was introduced to expose d55180 1 a55180 1 Only ‘tpidr’: d55182 2 a55183 2 − ‘tpidr’, the software thread id register. It is 64 bits in size and has a type of ‘data_ptr’. d55185 1 a55185 1 Both ‘tpidr’ and ‘tpidr2’. d55187 4 a55190 4 − ‘tpidr’, the software thread id register. It is 64 bits in size and has a type of ‘data_ptr’. − ‘tpidr2’, the second software thread id register. It is 64 bits in size and has a type of ‘data_ptr’. It may be used in the future d55194 1 a55194 1 variations of the register set. If ‘tpidr2’ is available, GDB may act d55197 1 a55197 1 There is no XML for this feature as the presence of ‘tpidr2’ is d55206 1 a55206 1 The ‘org.gnu.gdb.aarch64.mte’ optional feature was introduced so GDB d55211 2 a55212 2 − ‘tag_ctl’, the tag control register. It is 64 bits in size and has a type of ‘uint64’. d55226 2 a55227 2 The ‘org.gnu.gdb.aarch64.sme’ feature is optional. If present, it should contain registers ‘ZA’, ‘SVG’ and ‘SVCR’. *Note AArch64 SME::. d55229 1 a55229 1 − ‘ZA’ is a register represented by a vector of SVLxSVL bytes. *Note d55232 1 a55232 1 − ‘SVG’ is a 64-bit register containing the value of SVG. *Note d55235 1 a55235 1 − ‘SVCR’ is a 64-bit status pseudo-register with two valid bits. Bit d55237 1 a55237 1 Bit 1 (ZA) shows whether the ‘ZA’ register state is active (in use) d55240 1 a55240 1 The rest of the unused bits of the ‘SVCR’ pseudo-register is d55247 2 a55248 2 The ‘org.gnu.gdb.aarch64.sme’ feature is required when the target also reports support for the ‘org.gnu.gdb.aarch64.sme2’ feature. d55253 3 a55255 3 The ‘org.gnu.gdb.aarch64.sme2’ feature is optional. If present, then the ‘org.gnu.gdb.aarch64.sme’ feature must also be present. The ‘org.gnu.gdb.aarch64.sme2’ feature should contain the following: *Note d55258 1 a55258 1 − ‘ZT0’ is a register of 512 bits (64 bytes). It is defined as a d55274 1 a55274 1 ‘org.gnu.gdb.arc.core’ and ‘org.gnu.gdb.arc.aux’. d55276 1 a55276 1 The ‘org.gnu.gdb.arc.core’ feature is required for all targets. It d55279 2 a55280 2 − ‘r0’ through ‘r25’ for normal register file targets. − ‘r0’ through ‘r3’, and ‘r10’ through ‘r15’ for reduced register d55282 1 a55282 1 − ‘gp’, ‘fp’, ‘sp’, ‘r30’(1), ‘blink’, ‘lp_count’, ‘pcl’. d55285 7 a55291 7 ‘org.gnu.gdb.arc.core’ feature may contain registers ‘ilink1’ and ‘ilink2’. While in case of ARC EM and ARC HS targets (ARCv2 ISA), register ‘ilink’ may be present. The difference between ARCv1 and ARCv2 is the naming of registers _29th_ and _30th_. They are called ‘ilink1’ and ‘ilink2’ for ARCv1 and are optional. For ARCv2, they are called ‘ilink’ and ‘r30’ and only ‘ilink’ is optional. The optionality of ‘ilink*’ registers is because of their inaccessibility during user space d55294 1 a55294 1 Extension core registers ‘r32’ through ‘r59’ are optional and their d55299 1 a55299 1 The ‘org.gnu.gdb.arc.aux’ feature is required for all ARC targets. d55302 2 a55303 2 − mandatory: ‘pc’ and ‘status32’. − optional: ‘lp_start’, ‘lp_end’, and ‘bta’. d55318 1 a55318 1 The ‘org.gnu.gdb.arm.core’ feature is required for non-M-profile ARM d55321 8 a55328 8 − ‘r0’ through ‘r12’. The general purpose registers. They are 32 bits in size and have a type of ‘uint32’. − ‘sp’, the stack pointer register, also known as ‘r13’. It is 32 bits in size and has a type of ‘data_ptr’. − ‘lr’, the link register. It is 32 bits in size. − ‘pc’, the program counter register. It is 32 bit in size and of type ‘code_ptr’. − ‘cpsr’, the current program status register containing all the d55339 2 a55340 2 For M-profile targets (e.g. Cortex-M3), the ‘org.gnu.gdb.arm.core’ feature is replaced by ‘org.gnu.gdb.arm.m-profile’, and it is a required d55343 8 a55350 8 − ‘r0’ through ‘r12’, the general purpose registers. They have a size of 32 bits and a type of ‘uint32’. − ‘sp’, the stack pointer register, also known as ‘r13’. It has a size of 32 bits and a type of ‘data_ptr’. − ‘lr’, the link register. It has a size of 32 bits. − ‘pc’, the program counter register. It has a size of 32 bits and a type of ‘code_ptr’. − ‘xpsr’, the program status register containing all the status bits. d55365 1 a55365 1 The ‘org.gnu.gdb.arm.fpa’ feature is obsolete and should not be d55378 2 a55379 2 − ‘f0’ through ‘f8’. The floating point registers. They are 96 bits in size and of type ‘arm_fpa_ext’. ‘f0’ is pinned to register d55381 1 a55381 1 − ‘fps’, the status register. It has a size of 32 bits. d55387 1 a55387 1 the optional ‘org.gnu.gdb.arm.m-profile-mve’ feature. d55391 1 a55391 1 − ‘vpr’, the vector predication status and control register. It is d55393 2 a55394 2 laid out in a way that exposes the ‘P0’ field from bits 0 to 15, the ‘MASK01’ field from bits 16 to 19 and the ‘MASK23’ field from d55399 2 a55400 2 When this feature is available, GDB will synthesize the ‘p0’ pseudo-register from ‘vpr’ contents. d55406 3 a55408 3 If the ‘org.gnu.gdb.arm.vfp’ feature is available alongside the ‘org.gnu.gdb.arm.m-profile-mve’ feature, GDB will synthesize the ‘q’ pseudo-registers from ‘d’ register contents. d55416 1 a55416 1 The XScale ‘org.gnu.gdb.xscale.iwmmxt’ feature is optional. If present, d55419 6 a55424 6 − ‘wR0’ through ‘wR15’, registers with size 64 bits and a custom type ‘iwmmxt_vec64i’. ‘iwmmxt_vec64i’ is a union of four other types: ‘uint64’, a 2-element vector of ‘uint32’, a 4-element vector of ‘uint16’ and a 8-element vector of ‘uint8’. − ‘wCGR0’ through ‘wCGR3’, registers with size 32 bits and type ‘int’. d55428 4 a55431 4 − ‘wCID’, register with size of 32 bits and type ‘int’. − ‘wCon’, register with size 32 bits and type ‘int’. − ‘wCSSF’, register with size 32 bits and type ‘int’. − ‘wCASF’, register with size 32 bit and type ‘int’. d55441 1 a55441 1 The ‘org.gnu.gdb.arm.vfp’ feature is optional. If present, it should d55447 4 a55450 4 − ‘d0’ through ‘d15’. The double-precision registers. They are 64 bits in size and have type ‘ieee_double’. − ‘fpscr’, the floating-point status and control register. It has a size of 32 bits and a type of ‘int’. d55454 4 a55457 4 − ‘d0’ through ‘d31’. The double-precision registers. They are 64 bits in size and have type ‘ieee_double’. − ‘fpscr’, the floating-point status and control register. It has a size of 32 bits and a type of ‘int’. d55469 1 a55469 1 The ‘org.gnu.gdb.arm.neon’ feature is optional. It does not need to d55473 1 a55473 1 ‘org.gnu.gdb.arm.vfp’ must also be present and include 32 d55482 1 a55482 1 The ‘org.gnu.gdb.arm.m-profile-pacbti’ feature is optional, and d55499 1 a55499 1 The ‘org.gnu.gdb.arm.m-system’ optional feature was introduced as a way d55504 4 a55507 4 − ‘msp’, the main stack pointer register. It is 32 bits in size with type ‘data_ptr’. − ‘psp’, the process stack pointer register. It is 32 bits in size with type ‘data_ptr’. d55510 2 a55511 2 sees this feature, it will attempt to track the values of ‘msp’ and ‘psp’ across frames. d55519 1 a55519 1 The ‘org.gnu.gdb.arm.secext’ optional feature was introduced so GDB d55525 8 a55532 8 − ‘msp_ns’, the main stack pointer register (non-secure state). It is 32 bits in size with type ‘data_ptr’. − ‘psp_ns’, the process stack pointer register (non-secure state). It is 32 bits in size with type ‘data_ptr’. − ‘msp_s’, the main stack pointer register (secure state). It is 32 bits in size with type ‘data_ptr’. − ‘psp_s’, the process stack pointer register (secure state). It is 32 bits in size with type ‘data_ptr’. d55544 1 a55544 1 The optional ‘org.gnu.gdb.arm.tls’ feature contains TLS registers. d55548 2 a55549 2 − ‘tpidruro’, the user read-only thread id register. It is 32 bits in size and has type ‘data_ptr’. d55563 1 a55563 1 The ‘org.gnu.gdb.i386.core’ feature is required for i386/amd64 targets. d55566 6 a55571 6 − ‘eax’ through ‘edi’ plus ‘eip’ for i386 − ‘rax’ through ‘r15’ plus ‘rip’ for amd64 − ‘eflags’, ‘cs’, ‘ss’, ‘ds’, ‘es’, ‘fs’, ‘gs’ − ‘st0’ through ‘st7’ − ‘fctrl’, ‘fstat’, ‘ftag’, ‘fiseg’, ‘fioff’, ‘foseg’, ‘fooff’ and ‘fop’ d55575 1 a55575 1 The ‘org.gnu.gdb.i386.sse’ feature is optional. It should describe d55578 3 a55580 3 − ‘xmm0’ through ‘xmm7’ for i386 − ‘xmm0’ through ‘xmm15’ for amd64 − ‘mxcsr’ d55582 2 a55583 2 The ‘org.gnu.gdb.i386.avx’ feature is optional and requires the ‘org.gnu.gdb.i386.sse’ feature. It should describe the upper 128 bits d55586 2 a55587 2 − ‘ymm0h’ through ‘ymm7h’ for i386 − ‘ymm0h’ through ‘ymm15h’ for amd64 d55589 1 a55589 1 The ‘org.gnu.gdb.i386.mpx’ is an optional feature representing Intel d55593 2 a55594 2 − ‘bnd0raw’ through ‘bnd3raw’ for i386 and amd64. − ‘bndcfgu’ and ‘bndstatus’ for i386 and amd64. d55596 2 a55597 2 The ‘org.gnu.gdb.i386.linux’ feature is optional. It should describe a single register, ‘orig_eax’. d55599 2 a55600 2 The ‘org.gnu.gdb.i386.segments’ feature is optional. It should describe two system registers: ‘fs_base’ and ‘gs_base’. d55602 2 a55603 2 The ‘org.gnu.gdb.i386.avx512’ feature is optional and requires the ‘org.gnu.gdb.i386.avx’ feature. It should describe additional XMM d55606 1 a55606 1 − ‘xmm16h’ through ‘xmm31h’, only valid for amd64. d55610 1 a55610 1 − ‘ymm16h’ through ‘ymm31h’, only valid for amd64. d55614 2 a55615 2 − ‘zmm0h’ through ‘zmm7h’ for i386. − ‘zmm0h’ through ‘zmm15h’ for amd64. d55619 1 a55619 1 − ‘zmm16h’ through ‘zmm31h’, only valid for amd64. d55621 2 a55622 2 The ‘org.gnu.gdb.i386.pkeys’ feature is optional. It should describe a single register, ‘pkru’. It is a 32-bit register valid for i386 and d55631 4 a55634 4 The ‘org.gnu.gdb.loongarch.base’ feature is required for LoongArch targets. It should contain the registers ‘r0’ through ‘r31’, ‘pc’, and ‘badv’. Either the architectural names (‘r0’, ‘r1’, etc) can be used, or the ABI names (‘zero’, ‘ra’, etc). d55636 2 a55637 2 The ‘org.gnu.gdb.loongarch.fpu’ feature is optional. If present, it should contain registers ‘f0’ through ‘f31’, ‘fcc’, and ‘fcsr’. d55645 4 a55648 4 The ‘org.gnu.gdb.microblaze.core’ feature is required for MicroBlaze targets. It should contain registers ‘r0’ through ‘r31’, ‘rpc’, ‘rmsr’, ‘rear’, ‘resr’, ‘rfsr’, ‘rbtr’, ‘rpvr’, ‘rpvr1’ through ‘rpvr11’, ‘redr’, ‘rpid’, ‘rzpr’, ‘rtlbx’, ‘rtlbsx’, ‘rtlblo’, and ‘rtlbhi’. d55650 2 a55651 2 The ‘org.gnu.gdb.microblaze.stack-protect’ feature is optional. If present, it should contain registers ‘rshr’ and ‘rslr’ d55659 2 a55660 2 The ‘org.gnu.gdb.mips.cpu’ feature is required for MIPS targets. It should contain registers ‘r0’ through ‘r31’, ‘lo’, ‘hi’, and ‘pc’. They d55663 2 a55664 2 The ‘org.gnu.gdb.mips.cp0’ feature is also required. It should contain at least the ‘status’, ‘badvaddr’, and ‘cause’ registers. They d55667 1 a55667 1 The ‘org.gnu.gdb.mips.fpu’ feature is currently required, though it d55669 1 a55669 1 ‘f0’ through ‘f31’, ‘fcsr’, and ‘fir’. They may be 32-bit or 64-bit d55672 3 a55674 3 The ‘org.gnu.gdb.mips.dsp’ feature is optional. It should contain registers ‘hi1’ through ‘hi3’, ‘lo1’ through ‘lo3’, and ‘dspctl’. The ‘dspctl’ register should be 32-bit and the rest may be 32-bit or 64-bit d55677 2 a55678 2 The ‘org.gnu.gdb.mips.linux’ feature is optional. It should contain a single register, ‘restart’, which is used by the Linux kernel to d55687 3 a55689 3 ‘‘org.gnu.gdb.m68k.core’’ ‘‘org.gnu.gdb.coldfire.core’’ ‘‘org.gnu.gdb.fido.core’’ d55692 2 a55693 2 is present should contain registers ‘d0’ through ‘d7’, ‘a0’ through ‘a5’, ‘fp’, ‘sp’, ‘ps’ and ‘pc’. d55695 1 a55695 1 ‘‘org.gnu.gdb.coldfire.fp’’ d55697 1 a55697 1 ‘fp0’ through ‘fp7’, ‘fpcontrol’, ‘fpstatus’ and ‘fpiaddr’. d55700 1 a55700 1 ‘coldfire’, it is used to describe any floating point registers. d55702 1 a55702 1 example, if the primary feature is reported as ‘coldfire’, then d55711 7 a55717 7 The ‘org.gnu.gdb.nds32.core’ feature is required for NDS32 targets. It should contain at least registers ‘r0’ through ‘r10’, ‘r15’, ‘fp’, ‘gp’, ‘lp’, ‘sp’, and ‘pc’. The ‘org.gnu.gdb.nds32.fpu’ feature is optional. If present, it should contain 64-bit double-precision floating-point registers ‘fd0’ through _fdN_, which should be ‘fd3’, ‘fd7’, ‘fd15’, or ‘fd31’ based on d55734 4 a55737 4 The ‘org.gnu.gdb.nios2.cpu’ feature is required for Nios II targets. It should contain the 32 core registers (‘zero’, ‘at’, ‘r2’ through ‘r23’, ‘et’ through ‘ra’), ‘pc’, and the 16 control registers (‘status’ through ‘mpuacc’). d55745 3 a55747 3 The ‘org.gnu.gdb.or1k.group0’ feature is required for OpenRISC 1000 targets. It should contain the 32 general purpose registers (‘r0’ through ‘r31’), ‘ppc’, ‘npc’ and ‘sr’. d55755 31 a55785 31 The ‘org.gnu.gdb.power.core’ feature is required for PowerPC targets. It should contain registers ‘r0’ through ‘r31’, ‘pc’, ‘msr’, ‘cr’, ‘lr’, ‘ctr’, and ‘xer’. They may be 32-bit or 64-bit depending on the target. The ‘org.gnu.gdb.power.fpu’ feature is optional. It should contain registers ‘f0’ through ‘f31’ and ‘fpscr’. The ‘org.gnu.gdb.power.altivec’ feature is optional. It should contain registers ‘vr0’ through ‘vr31’, ‘vscr’, and ‘vrsave’. GDB will define pseudo-registers ‘v0’ through ‘v31’ as aliases for the corresponding ‘vrX’ registers. The ‘org.gnu.gdb.power.vsx’ feature is optional. It should contain registers ‘vs0h’ through ‘vs31h’. GDB will combine these registers with the floating point registers (‘f0’ through ‘f31’) and the altivec registers (‘vr0’ through ‘vr31’) to present the 128-bit wide registers ‘vs0’ through ‘vs63’, the set of vector-scalar registers for POWER7. Therefore, this feature requires both ‘org.gnu.gdb.power.fpu’ and ‘org.gnu.gdb.power.altivec’. The ‘org.gnu.gdb.power.spe’ feature is optional. It should contain registers ‘ev0h’ through ‘ev31h’, ‘acc’, and ‘spefscr’. SPE targets should provide 32-bit registers in ‘org.gnu.gdb.power.core’ and provide the upper halves in ‘ev0h’ through ‘ev31h’. GDB will combine these to present registers ‘ev0’ through ‘ev31’ to the user. The ‘org.gnu.gdb.power.ppr’ feature is optional. It should contain the 64-bit register ‘ppr’. The ‘org.gnu.gdb.power.dscr’ feature is optional. It should contain the 64-bit register ‘dscr’. d55787 2 a55788 2 The ‘org.gnu.gdb.power.tar’ feature is optional. It should contain the 64-bit register ‘tar’. d55790 2 a55791 2 The ‘org.gnu.gdb.power.ebb’ feature is optional. It should contain registers ‘bescr’, ‘ebbhr’ and ‘ebbrr’, all 64-bit wide. d55793 2 a55794 2 The ‘org.gnu.gdb.power.linux.pmu’ feature is optional. It should contain registers ‘mmcr0’, ‘mmcr2’, ‘siar’, ‘sdar’ and ‘sier’, all d55798 2 a55799 2 The ‘org.gnu.gdb.power.htm.spr’ feature is optional. It should contain registers ‘tfhar’, ‘texasr’ and ‘tfiar’, all 64-bit wide. d55801 3 a55803 3 The ‘org.gnu.gdb.power.htm.core’ feature is optional. It should contain the checkpointed general-purpose registers ‘cr0’ through ‘cr31’, as well as the checkpointed registers ‘clr’ and ‘cctr’. These registers d55805 1 a55805 1 also contain the checkpointed registers ‘ccr’ and ‘cxer’, which should d55808 16 a55823 16 The ‘org.gnu.gdb.power.htm.fpu’ feature is optional. It should contain the checkpointed 64-bit floating-point registers ‘cf0’ through ‘cf31’, as well as the checkpointed 64-bit register ‘cfpscr’. The ‘org.gnu.gdb.power.htm.altivec’ feature is optional. It should contain the checkpointed altivec registers ‘cvr0’ through ‘cvr31’, all 128-bit wide. It should also contain the checkpointed registers ‘cvscr’ and ‘cvrsave’, both 32-bit wide. The ‘org.gnu.gdb.power.htm.vsx’ feature is optional. It should contain registers ‘cvs0h’ through ‘cvs31h’. GDB will combine these registers with the checkpointed floating point registers (‘cf0’ through ‘cf31’) and the checkpointed altivec registers (‘cvr0’ through ‘cvr31’) to present the 128-bit wide checkpointed vector-scalar registers ‘cvs0’ through ‘cvs63’. Therefore, this feature requires both ‘org.gnu.gdb.power.htm.altivec’ and ‘org.gnu.gdb.power.htm.fpu’. d55825 2 a55826 2 The ‘org.gnu.gdb.power.htm.ppr’ feature is optional. It should contain the 64-bit checkpointed register ‘cppr’. d55828 2 a55829 2 The ‘org.gnu.gdb.power.htm.dscr’ feature is optional. It should contain the 64-bit checkpointed register ‘cdscr’. d55831 2 a55832 2 The ‘org.gnu.gdb.power.htm.tar’ feature is optional. It should contain the 64-bit checkpointed register ‘ctar’. d55840 8 a55847 8 The ‘org.gnu.gdb.riscv.cpu’ feature is required for RISC-V targets. It should contain the registers ‘x0’ through ‘x31’, and ‘pc’. Either the architectural names (‘x0’, ‘x1’, etc) can be used, or the ABI names (‘zero’, ‘ra’, etc). The ‘org.gnu.gdb.riscv.fpu’ feature is optional. If present, it should contain registers ‘f0’ through ‘f31’, ‘fflags’, ‘frm’, and ‘fcsr’. As with the cpu feature, either the architectural register d55850 1 a55850 1 The ‘org.gnu.gdb.riscv.virtual’ feature is optional. If present, it d55855 1 a55855 1 register expected in this set is the one byte ‘priv’ register that d55858 1 a55858 1 The ‘org.gnu.gdb.riscv.csr’ feature is optional. If present, it d55861 2 a55862 2 overlap between this feature and the fpu feature; the ‘fflags’, ‘frm’, and ‘fcsr’ registers could be in either feature. The expectation is d55868 2 a55869 2 The ‘org.gnu.gdb.riscv.vector’ feature is optional. If present, it should contain registers ‘v0’ through ‘v31’, all of which must be the d55878 3 a55880 3 The ‘org.gnu.gdb.rx.core’ feature is required for RX targets. It should contain the registers ‘r0’ through ‘r15’, ‘usp’, ‘isp’, ‘psw’, ‘pc’, ‘intb’, ‘bpsw’, ‘bpc’, ‘fintv’, ‘fpsw’, and ‘acc’. d55888 1 a55888 1 The ‘org.gnu.gdb.s390.core’ feature is required for S/390 and System z d55890 2 a55891 2 particular, System z targets should provide the 64-bit registers ‘pswm’, ‘pswa’, and ‘r0’ through ‘r15’. S/390 targets should provide the 32-bit d55893 13 a55905 13 addressing mode should provide 32-bit versions of ‘pswm’ and ‘pswa’, as well as the general register's upper halves ‘r0h’ through ‘r15h’, and their lower halves ‘r0l’ through ‘r15l’. The ‘org.gnu.gdb.s390.fpr’ feature is required. It should contain the 64-bit registers ‘f0’ through ‘f15’, and ‘fpc’. The ‘org.gnu.gdb.s390.acr’ feature is required. It should contain the 32-bit registers ‘acr0’ through ‘acr15’. The ‘org.gnu.gdb.s390.linux’ feature is optional. It should contain the register ‘orig_r2’, which is 64-bit wide on System z targets and 32-bit otherwise. In addition, the feature may contain the ‘last_break’ d55907 1 a55907 1 ‘system_call’ register, which is always 32-bit wide. d55909 18 a55926 18 The ‘org.gnu.gdb.s390.tdb’ feature is optional. It should contain the 64-bit registers ‘tdb0’, ‘tac’, ‘tct’, ‘atia’, and ‘tr0’ through ‘tr15’. The ‘org.gnu.gdb.s390.vx’ feature is optional. It should contain 64-bit wide registers ‘v0l’ through ‘v15l’, which will be combined by GDB with the floating point registers ‘f0’ through ‘f15’ to present the 128-bit wide vector registers ‘v0’ through ‘v15’. In addition, this feature should contain the 128-bit wide vector registers ‘v16’ through ‘v31’. The ‘org.gnu.gdb.s390.gs’ feature is optional. It should contain the 64-bit wide guarded-storage-control registers ‘gsd’, ‘gssm’, and ‘gsepla’. The ‘org.gnu.gdb.s390.gsbc’ feature is optional. It should contain the 64-bit wide guarded-storage broadcast control registers ‘bc_gsd’, ‘bc_gssm’, and ‘bc_gsepla’. d55934 1 a55934 1 The ‘org.gnu.gdb.sparc.cpu’ feature is required for sparc32/sparc64 d55937 4 a55940 4 − ‘g0’ through ‘g7’ − ‘o0’ through ‘o7’ − ‘l0’ through ‘l7’ − ‘i0’ through ‘i7’ d55944 1 a55944 1 Also the ‘org.gnu.gdb.sparc.fpu’ feature is required for d55947 2 a55948 2 − ‘f0’ through ‘f31’ − ‘f32’ through ‘f62’ for sparc64 d55950 1 a55950 1 The ‘org.gnu.gdb.sparc.cp0’ feature is required for sparc32/sparc64 d55953 2 a55954 2 − ‘y’, ‘psr’, ‘wim’, ‘tbr’, ‘pc’, ‘npc’, ‘fsr’, and ‘csr’ for sparc32 − ‘pc’, ‘npc’, ‘state’, ‘fsr’, ‘fprs’, and ‘y’ for sparc64 d55962 3 a55964 3 The ‘org.gnu.gdb.tic6x.core’ feature is required for TMS320C6x targets. It should contain registers ‘A0’ through ‘A15’, registers ‘B0’ through ‘B15’, ‘CSR’ and ‘PC’. d55966 2 a55967 2 The ‘org.gnu.gdb.tic6x.gp’ feature is optional. It should contain registers ‘A16’ through ‘A31’ and ‘B16’ through ‘B31’. d55969 2 a55970 2 The ‘org.gnu.gdb.tic6x.c6xp’ feature is optional. It should contain registers ‘TSR’, ‘ILC’ and ‘RILC’. d55986 2 a55987 2 remote protocol, using ‘qXfer’ requests (*note qXfer osdata read::). The object name in the request should be ‘osdata’, and the ANNEX d56000 3 a56002 3 When requesting the process list, the ANNEX field in the ‘qXfer’ request should be ‘processes’. The returned data is an XML document. The formal syntax of this document is defined in ‘gdb/features/osdata.dtd’. d56017 4 a56020 4 Each item should include a column whose name is ‘pid’. The value of that column should identify the process on the target. The ‘user’ and ‘command’ columns are optional, and will be displayed by GDB. The ‘cores’ column, if present, should contain a comma-separated list of d56033 2 a56034 2 The header has the form ‘\x7fTRACE0\n’. The first byte is ‘0x7f’ so as to indicate that the file contains binary data, while the ‘0’ is a d56038 1 a56038 1 separated by newline characters (‘0xa’). The lines may include a d56044 1 a56044 1 ‘R SIZE’ d56046 1 a56046 1 the size of a ‘g’ packet payload in the remote protocol. SIZE is d56050 2 a56051 2 ‘status STATUS’ Trace status. STATUS has the same format as a ‘qTStatus’ remote d56055 1 a56055 1 ‘tp PAYLOAD’ d56057 1 a56057 1 ‘qTfP’/‘qTsP’ remote packet reply payload. A single tracepoint may d56061 1 a56061 1 ‘tsv PAYLOAD’ d56063 1 a56063 1 as ‘qTfV’/‘qTsV’ remote packet reply payload. A single variable d56067 1 a56067 1 ‘tdesc PAYLOAD’ d56071 2 a56072 2 ‘qXfer’ ‘features’ payload, and corresponds to the main ‘target.xml’ file. Includes are not allowed. d56082 1 a56082 1 ‘R BYTES’ d56084 1 a56084 1 ‘g’ packet in the remote protocol. Note that these are the actual d56087 1 a56087 1 ‘M ADDRESS LENGTH BYTES...’ d56092 1 a56092 1 ‘V NUMBER VALUE’ d56102 1 a56102 1 Appendix J ‘.gdb_index’ section format d56105 2 a56106 2 This section documents the index section that is created by ‘save gdb-index’ (*note Index Files::). The index section is DWARF-specific; d56109 1 a56109 1 The mapped index file format is designed to be directly ‘mmap’able on d56111 1 a56111 1 little-endian 32-bit integer value, called an ‘offset_type’. Big endian d56118 1 a56118 1 1. The file header. This is a sequence of values, of ‘offset_type’ d56127 2 a56128 2 (‘DW_TAG_type_unit’) refer to the type unit's symbol table and not the compilation unit (‘DW_TAG_comp_unit’) using the type. d56133 1 a56133 1 ‘set use-deprecated-index-sections on’. GDB has a workaround d56153 1 a56153 1 the offset of a CU in the ‘.debug_info’ section. The second d56172 1 a56172 1 ‘DW_AT_high_pc’, the value is one byte beyond the end. d56174 1 a56174 1 3. The CU index. This is an ‘offset_type’ value. d56179 1 a56179 1 Each slot in the hash table consists of a pair of ‘offset_type’ d56190 1 a56190 1 initial value of ‘r = 0’, each (unsigned) character ‘c’ in the d56195 1 a56195 1 The formula is ‘r = r * 67 + c - 113’. d56198 1 a56198 1 The formula is ‘r = r * 67 + tolower (c) - 113’. d56200 1 a56200 1 The terminating ‘\0’ is not incorporated into the hash. d56202 2 a56203 2 The step size used in the hash table is computed via ‘((hash * 17) & (size - 1)) | 1’, where ‘hash’ is the hash value, and ‘size’ is d56216 2 a56217 2 An ‘offset_type’ value indicating the language of the main function as a ‘DW_LANG_’ constant. This value will be zero if d56221 1 a56221 1 An ‘offset_type’ value indicating the offset of the main d56229 1 a56229 1 A CU vector in the constant pool is a sequence of ‘offset_type’ d56238 1 a56238 1 Attributes were added to CU index values in ‘.gdb_index’ version 7. d56254 1 a56254 1 zero the full ‘offset_type’ value is backwards compatible with d56272 1 a56272 1 ‘dwarf2read.c’ in GDB sources. d56325 1 a56325 1 ‘debuginfod’ is an HTTP server for distributing ELF, DWARF and source d56328 1 a56328 1 With the ‘debuginfod’ client library, ‘libdebuginfod’, GDB can query d56332 3 a56334 3 For instructions on building GDB with ‘libdebuginfod’, *note -with-debuginfod: Configure Options. ‘debuginfod’ is packaged with ‘elfutils’, starting with version 0.178. See d56336 1 a56336 1 regarding ‘debuginfod’. d56348 1 a56348 1 GDB provides the following commands for configuring ‘debuginfod’. d56350 3 a56352 3 ‘set debuginfod enabled’ ‘set debuginfod enabled on’ GDB may query ‘debuginfod’ servers for missing debug info and d56354 3 a56356 3 such as ‘.gdb_index’ to help reduce the total amount of data downloaded from ‘debuginfod’ servers; this can be controlled by ‘maint set debuginfod download-sections’ (*note maint set d56359 19 a56377 19 ‘set debuginfod enabled off’ GDB will not attempt to query ‘debuginfod’ servers when missing debug info or source files. By default, ‘debuginfod enabled’ is set to ‘off’ for non-interactive sessions. ‘set debuginfod enabled ask’ GDB will prompt the user to enable or disable ‘debuginfod’ before attempting to perform the next query. By default, ‘debuginfod enabled’ is set to ‘ask’ for interactive sessions. ‘show debuginfod enabled’ Display whether ‘debuginfod enabled’ is set to ‘on’, ‘off’ or ‘ask’. ‘set debuginfod urls’ ‘set debuginfod urls URLS’ Set the space-separated list of URLs that ‘debuginfod’ will attempt to query. Only ‘http://’, ‘https://’ and ‘file://’ protocols should be used. The default value of ‘debuginfod urls’ is copied d56380 2 a56381 2 ‘show debuginfod urls’ Display the list of URLs that ‘debuginfod’ will attempt to query. d56383 4 a56386 4 ‘set debuginfod verbose’ ‘set debuginfod verbose N’ Enable or disable ‘debuginfod’-related output. Use a non-zero value to enable and ‘0’ to disable. ‘debuginfod’ output is shown d56389 1 a56389 1 ‘show debuginfod verbose’ d56421 1 a56421 1 • Start your program, specifying anything that might affect its d56424 1 a56424 1 • Make your program stop on specified conditions. d56426 1 a56426 1 • Examine what has happened, when your program has stopped. d56428 1 a56428 1 • Change things in your program, so you can experiment with d56434 1 a56434 1 GDB is invoked with the shell command ‘gdb’. Once started, it reads d56436 2 a56437 2 command ‘quit’ or ‘exit’. You can get online help from GDB itself by using the command ‘help’. d56439 1 a56439 1 You can run ‘gdb’ with no arguments or options; but the most usual d56451 1 a56451 1 option ‘-p’, if you want to debug a running process: d56456 1 a56456 1 would attach GDB to process ‘1234’. With option ‘-p’ you can omit the d56461 1 a56461 1 ‘break [FILE:][FUNCTION|LINE]’ d56464 1 a56464 1 ‘run [ARGLIST]’ d56467 1 a56467 1 ‘bt’ d56470 1 a56470 1 ‘print EXPR’ d56473 1 a56473 1 ‘c’ d56477 1 a56477 1 ‘next’ d56481 1 a56481 1 ‘edit [FILE:]FUNCTION’ d56484 1 a56484 1 ‘list [FILE:]FUNCTION’ d56488 1 a56488 1 ‘step’ d56492 1 a56492 1 ‘help [NAME]’ d56496 2 a56497 2 ‘quit’ ‘exit’ d56502 2 a56503 2 associated option flag is equivalent to a ‘--se’ option, and the second, if any, is equivalent to a ‘-c’ option if it's the name of a file. Many d56508 2 a56509 2 The abbreviated forms are shown here with ‘-’ and long forms are shown with ‘--’ to reflect how they are shown in ‘--help’. However, GDB d56512 8 a56519 8 ‘--option=VALUE’ ‘--option VALUE’ ‘-option=VALUE’ ‘-option VALUE’ ‘--o=VALUE’ ‘--o VALUE’ ‘-o=VALUE’ ‘-o VALUE’ d56522 1 a56522 1 sequential order. The order makes a difference when the ‘-x’ option is d56525 2 a56526 2 ‘--help’ ‘-h’ d56529 2 a56530 2 ‘--symbols=FILE’ ‘-s FILE’ d56533 1 a56533 1 ‘--write’ d56536 2 a56537 2 ‘--exec=FILE’ ‘-e FILE’ d56541 1 a56541 1 ‘--se=FILE’ d56544 2 a56545 2 ‘--core=FILE’ ‘-c FILE’ d56548 2 a56549 2 ‘--command=FILE’ ‘-x FILE’ d56552 2 a56553 2 ‘--eval-command=COMMAND’ ‘-ex COMMAND’ d56556 2 a56557 2 ‘--init-eval-command=COMMAND’ ‘-iex’ d56560 2 a56561 2 ‘--directory=DIRECTORY’ ‘-d DIRECTORY’ d56564 7 a56570 7 ‘--nh’ Do not execute commands from ‘~/.config/gdb/gdbinit’, ‘~/.gdbinit’, ‘~/.config/gdb/gdbearlyinit’, or ‘~/.gdbearlyinit’ ‘--nx’ ‘-n’ Do not execute commands from any ‘.gdbinit’ or ‘.gdbearlyinit’ d56573 3 a56575 3 ‘--quiet’ ‘--silent’ ‘-q’ d56579 3 a56581 3 ‘--batch’ Run in batch mode. Exit with status ‘0’ after processing all the command files specified with ‘-x’ (and ‘.gdbinit’, if not d56594 2 a56595 2 ‘--batch-silent’ Run in batch mode, just like ‘--batch’, but totally silent. All d56597 1 a56597 1 quieter than ‘--silent’ and would be useless for an interactive d56600 2 a56601 2 This is particularly useful when using targets that give ‘Loading section’ messages, for example. d56604 1 a56604 1 writing directly to ‘stdout’, will also be made silent. d56606 1 a56606 1 ‘--args PROG [ARGLIST]’ d56613 1 a56613 1 It would start GDB with ‘-q’, not printing the introductory d56621 1 a56621 1 ‘--pid=PID’ d56624 1 a56624 1 ‘--tui’ d56627 1 a56627 1 ‘--readnow’ d56630 1 a56630 1 ‘--readnever’ d56633 1 a56633 1 ‘--return-child-result’ d56636 1 a56636 1 ‘--configuration’ d56639 1 a56639 1 ‘--version’ d56642 1 a56642 1 ‘--cd=DIRECTORY’ d56646 2 a56647 2 ‘--data-directory=DIRECTORY’ ‘-D’ d56651 2 a56652 2 ‘--fullname’ ‘-f’ d56657 1 a56657 1 looks like two ‘\032’ characters, followed by the file name, line d56659 1 a56659 1 The Emacs-to-GDB interface program uses the two ‘\032’ characters d56662 1 a56662 1 ‘-b BAUDRATE’ d56666 1 a56666 1 ‘-l TIMEOUT’ d56669 1 a56669 1 ‘--tty=DEVICE’ d56684 1 a56684 1 ‘gdbserver’ is a program that allows you to run GDB on a different d56692 1 a56692 1 as ‘gdbserver’ doesn't care about symbols. All symbol handling is taken d56696 1 a56696 1 ‘gdbserver’ program. You must tell it (a) how to communicate with GDB, d56706 2 a56707 2 This tells ‘gdbserver’ to debug emacs with an argument of foo.txt, and to communicate with GDB via ‘/dev/com1’. ‘gdbserver’ now waits d56715 3 a56717 3 we are going to communicate with the ‘host’ GDB via TCP. The ‘host:2345’ argument means that we are expecting to see a TCP connection from ‘host’ to local TCP port 2345. (Currently, the ‘host’ part is ignored.) You d56720 1 a56720 1 same port number must be used in the host GDBs ‘target remote’ command, d56722 1 a56722 1 that conflicts with another service, ‘gdbserver’ will print an error d56725 2 a56726 2 ‘gdbserver’ can also attach to running programs. This is accomplished via the ‘--attach’ argument. The syntax is: d56731 1 a56731 1 necessary to point ‘gdbserver’ at a binary for the running process. d56733 3 a56735 3 To start ‘gdbserver’ without supplying an initial command to run or process ID to attach, use the ‘--multi’ command line option. In such case you should connect using ‘target extended-remote’ to start the d56746 6 a56751 6 may need to use the ‘--baud’ option if the serial line is running at anything except 9600 baud.) That is ‘gdb TARGET-PROG’, or ‘gdb --baud BAUD TARGET-PROG’. After that, the only new command you need to know about is ‘target remote’ (or ‘target extended-remote’). Its argument is either a device name (usually a serial device, like ‘/dev/ttyb’), or a ‘HOST:PORT’ descriptor. For example: d56755 1 a56755 1 communicates with the server via serial line ‘/dev/ttyb’, and: d56760 2 a56761 2 where you previously started up ‘gdbserver’ with the same port number. Note that for TCP connections, you must start up ‘gdbserver’ prior to d56765 1 a56765 1 ‘gdbserver’ can also debug multiple inferiors at once, described in d56767 1 a56767 1 ‘extended-remote’ GDB command variant: d56771 1 a56771 1 The ‘gdbserver’ option ‘--multi’ may or may not be used in such case. d56773 1 a56773 1 There are three different modes for invoking ‘gdbserver’: d56775 1 a56775 1 • Debug a specific program specified by its program name: d56781 2 a56782 2 number (‘:1234’), or ‘-’ or ‘stdio’ to use stdin/stdout of ‘gdbserver’. Specify the name of the program to debug in PROG. d56785 1 a56785 1 ‘gdbserver’ will exit. d56787 1 a56787 1 • Debug a specific program by specifying the process ID of a running d56795 1 a56795 1 connection, and ‘gdbserver’ will exit. d56797 1 a56797 1 • Multi-process mode - debug more than one program/process: d56801 1 a56801 1 In this mode, GDB can instruct ‘gdbserver’ which command(s) to run. d56808 1 a56808 1 ‘--help’ d56811 2 a56812 2 ‘--version’ This option causes ‘gdbserver’ to print its version number and d56815 2 a56816 2 ‘--attach’ ‘gdbserver’ will attach to a running program. The syntax is: d56821 1 a56821 1 necessary to point ‘gdbserver’ at a binary for the running process. d56823 2 a56824 2 ‘--multi’ To start ‘gdbserver’ without supplying an initial command to run or d56826 1 a56826 1 connect using ‘target extended-remote’ and start the program you d56831 3 a56833 3 ‘--debug[=option1,option2,...]’ Instruct ‘gdbserver’ to display extra status information about the debugging process. This option is intended for ‘gdbserver’ d56837 2 a56838 2 be enabled. The list of possible options is ‘all’, ‘threads’, ‘event-loop’, ‘remote’. The special option ‘all’ enables all d56840 1 a56840 1 option can be prefixed with the ‘-’ character to disable output for d56845 8 a56852 8 to turn on debug output for all components except ‘event-loop’. If no options are passed to ‘--debug’ then this is treated as equivalent to ‘--debug=threads’. This could change in future releases of ‘gdbserver’. ‘--debug-file=FILENAME’ Instruct ‘gdbserver’ to send any debug output to the given FILENAME. This option is intended for ‘gdbserver’ development and d56855 2 a56856 2 ‘--debug-format=option1[,option2,...]’ Instruct ‘gdbserver’ to include extra information in each line of d56860 1 a56860 1 ‘--wrapper’ d56863 1 a56863 1 command-line arguments to pass to the wrapper, then ‘--’ indicating d56866 2 a56867 2 ‘--once’ By default, ‘gdbserver’ keeps the listening TCP port open, so that d56869 1 a56869 1 ‘gdbserver’ with the ‘--once’ option, it will stop listening for d56882 2 a56883 2 PID1, PID2, etc. A core file produced by ‘gcore’ is equivalent to one produced by the kernel when the process crashes (and when ‘ulimit -c’ d56885 1 a56885 1 after a crash, after ‘gcore’ finishes its job the program remains d56888 1 a56888 1 ‘-a’ d56891 2 a56892 2 ‘use-coredump-filter’ (*note set use-coredump-filter::) and enable ‘dump-excluded-mappings’ (*note set dump-excluded-mappings::). d56894 1 a56894 1 ‘-o PREFIX’ d56897 2 a56898 2 composed as ‘PREFIX.PID’, where PID is the process ID of the running program being analyzed by ‘gcore’. If not specified, d56921 1 a56921 1 ‘(not enabled with --with-system-gdbinit during compilation)’ d56923 2 a56924 2 specified GDB option ‘-nx’ or ‘-n’. See more in ‘(not enabled with --with-system-gdbinit-dir during compilation)’ d56926 2 a56927 2 are executed on startup unless user specified GDB option ‘-nx’ or ‘-n’, as long as they have a recognized file extension. See more d56930 1 a56930 1 ‘~/.config/gdb/gdbinit or ~/.gdbinit’ d56932 1 a56932 1 options ‘-nx’, ‘-n’ or ‘-nh’. d56934 1 a56934 1 ‘.gdbinit’ d56936 1 a56936 1 enabled with GDB security command ‘set auto-load local-gdbinit’. d56954 2 a56955 2 ‘readelf -S filename’: the index is stored in a section named ‘.gdb_index’. The index file can only be produced on systems which use d56957 1 a56957 1 ‘.debug_*’). d56959 1 a56959 1 ‘gdb-add-index’ uses GDB and ‘objdump’ found in the ‘PATH’ d56961 1 a56961 1 programs, you can specify them through the ‘GDB’ and ‘OBJDUMP’ d56974 1 a56974 1 Copyright © 2007 Free Software Foundation, Inc. d57661 1 a57661 1 This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’. d57663 1 a57663 1 under certain conditions; type ‘show c’ for details. d57665 1 a57665 1 The hypothetical commands ‘show w’ and ‘show c’ should show the d57690 1 a57690 1 Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. d57699 1 a57699 1 functional and useful document “free” in the sense of freedom: to d58173 10 a58182 2 * _NSPrintForDebugger, and printing Objective-C objects: The Print Command with Objective-C. (line 11) d58194 1 a58196 1 * --debug, gdbserver option: Server. (line 146) a58253 2 * ! packet: Packets. (line 49) * ? packet: Packets. (line 58) d58262 2 a58266 2 * .gdbinit: Initialization Files. (line 107) a58272 2 * "No symbol "foo" in current context": Variables. (line 122) * {TYPE}: Expressions. (line 41) a58274 3 * &, background execution of commands: Background Execution. (line 16) * # in Modula-2: GDB/M2. (line 18) d58294 4 a58297 5 * $: Value History. (line 13) * $_ and info breakpoints: Set Breaks. (line 244) * $_ and info line: Machine Code. (line 35) * $_, $__, and value history: Memory. (line 136) * $$: Value History. (line 13) d58454 1 a58454 1 (line 1050) d58568 1 a58569 1 * colon, doubled as scope operator: M2 Scope. (line 6) d58651 1 a58651 1 (line 146) d58749 1 a58749 1 (line 466) d58761 1 a58761 1 * display GDB copyright: Help. (line 174) d58840 1 a58840 1 (line 612) d58874 1 a58874 1 (line 655) d58954 1 a58954 1 * GDB version number: Help. (line 164) d59236 1 a59236 1 (line 466) d59328 1 a59328 1 (line 980) d59434 1 a59434 1 (line 886) d59496 1 a59496 1 (line 188) d59539 1 a59541 1 * protocol, GDB remote serial: Overview. (line 14) d59584 1 a59584 1 (line 1452) d59622 1 a59622 1 (line 612) d59624 1 a59624 1 (line 633) d59628 1 a59628 1 (line 644) d59634 1 a59634 1 (line 655) d59636 1 a59636 1 (line 1118) d59652 1 a59652 1 (line 1161) d59671 1 a59671 1 (line 1452) d59676 1 a59676 1 (line 1198) d59686 1 a59686 1 * raw printing: Output Formats. (line 77) d59688 2 a59689 1 (line 1198) a59690 1 * read, file-i/o system call: read. (line 6) d59817 1 a59817 1 (line 466) d59821 1 a59821 1 (line 633) d59957 1 a59957 1 (line 1028) d59979 1 a59979 1 (line 1045) d59998 1 a59998 1 (line 655) d60015 1 a60015 1 (line 1118) d60035 1 a60039 1 * system, file-i/o system call: system. (line 6) d60102 1 a60102 1 (line 1161) d60275 1 a60275 1 (line 1420) d60326 59 a60384 1 * __init__ on TypePrinter: gdb.types. (line 82) a60617 13 * !: Shell Commands. (line 10) * @@, referencing memory as an array: Arrays. (line 6) * # (a comment): Command Syntax. (line 37) * ^connected: GDB/MI Result Records. (line 21) * ^done: GDB/MI Result Records. (line 9) * ^error: GDB/MI Result Records. (line 24) * ^exit: GDB/MI Result Records. (line 35) * ^running: GDB/MI Result Records. (line 13) d60636 12 a60648 57 * $__, convenience variable: Convenience Vars. (line 74) * $_, convenience variable: Convenience Vars. (line 65) * $_ada_exception, convenience variable: Set Catchpoints. (line 82) * $_any_caller_is, convenience function: Convenience Funs. (line 229) * $_any_caller_matches, convenience function: Convenience Funs. (line 241) * $_as_string, convenience function: Convenience Funs. (line 253) * $_caller_is, convenience function: Convenience Funs. (line 199) * $_caller_matches, convenience function: Convenience Funs. (line 222) * $_cimag, convenience function: Convenience Funs. (line 267) * $_creal, convenience function: Convenience Funs. (line 267) * $_exception, convenience variable: Set Catchpoints. (line 21) * $_exitcode, convenience variable: Convenience Vars. (line 80) * $_exitsignal, convenience variable: Convenience Vars. (line 85) * $_gdb_maint_setting_str, convenience function: Convenience Funs. (line 124) * $_gdb_maint_setting, convenience function: Convenience Funs. (line 128) * $_gdb_major, convenience variable: Convenience Vars. (line 183) * $_gdb_minor, convenience variable: Convenience Vars. (line 183) * $_gdb_setting_str, convenience function: Convenience Funs. (line 62) * $_gdb_setting, convenience function: Convenience Funs. (line 75) * $_gthread, convenience variable: Threads. (line 98) * $_hit_bpnum, convenience variable: Set Breaks. (line 24) * $_hit_locno, convenience variable: Set Breaks. (line 24) * $_inferior_thread_count, convenience variable: Threads. (line 98) * $_inferior, convenience variable: Inferiors Connections and Programs. (line 107) * $_isvoid, convenience function: Convenience Funs. (line 14) * $_memeq, convenience function: Convenience Funs. (line 183) * $_probe_arg, convenience variable: Static Probe Points. (line 77) * $_regex, convenience function: Convenience Funs. (line 187) * $_sdata, collect: Tracepoint Actions. (line 86) * $_sdata, inspect, convenience variable: Convenience Vars. (line 147) * $_shell_exitcode, convenience variable: Convenience Vars. (line 192) * $_shell_exitsignal, convenience variable: Convenience Vars. (line 192) * $_shell, convenience function: Convenience Funs. (line 132) * $_siginfo, convenience variable: Convenience Vars. (line 153) * $_streq, convenience function: Convenience Funs. (line 192) * $_strlen, convenience function: Convenience Funs. (line 196) * $_thread, convenience variable: Threads. (line 98) * $_tlb, convenience variable: Convenience Vars. (line 159) * $bpnum, convenience variable: Set Breaks. (line 6) * $cdir, convenience variable: Source Path. (line 40) * $cwd, convenience variable: Source Path. (line 40) * $tpnum: Create and Delete Tracepoints. (line 124) * $trace_file: Tracepoint Variables. (line 16) * $trace_frame: Tracepoint Variables. (line 6) * $trace_func: Tracepoint Variables. (line 19) * $trace_line: Tracepoint Variables. (line 13) * $tracepoint: Tracepoint Variables. (line 10) d60661 1 a60661 1 (line 119) d60737 2 a60740 2 * Architecture.registers: Architectures In Python. (line 61) a60776 1 * block?: Blocks In Guile. (line 55) d60786 1 a60819 1 * break-range: PowerPC Embedded. (line 41) d60822 1 a60858 6 * breakpoint?: Breakpoints In Guile. (line 118) * Breakpoint.__init__: Breakpoints In Python. (line 16) * Breakpoint.__init__ <1>: Breakpoints In Python. (line 49) d60899 6 d60926 1 a60926 1 (line 493) d60965 2 a60968 2 * clear, and Objective-C: Method Names in Commands. (line 9) d60971 1 a60971 1 (line 135) d60978 11 a61026 11 * command?: Commands In Guile. (line 63) * Command.__init__: CLI Commands In Python. (line 10) * Command.complete: CLI Commands In Python. (line 72) * Command.dont_repeat: CLI Commands In Python. (line 42) * Command.invoke: CLI Commands In Python. (line 50) * commands: Break Commands. (line 11) * commands annotation: Prompting. (line 27) d61066 1 a61066 1 * ConnectionEvent.connection: Events In Python. (line 279) d61118 1 a61118 1 (line 168) a61137 2 * DisassembleInfo.__init__: Disassembly In Python. (line 46) d61152 2 d61159 1 a61159 1 (line 310) d61161 1 a61161 3 (line 258) * DisassemblerResult.__init__: Disassembly In Python. (line 185) d61163 1 a61163 1 (line 209) d61165 1 a61165 1 (line 226) d61167 3 a61169 1 (line 213) d61171 1 a61171 1 (line 274) d61254 2 a61255 2 * ExecutableChangedEvent.progspace: Events In Python. (line 292) * ExecutableChangedEvent.reload: Events In Python. (line 297) a61288 2 * FinishBreakpoint.__init__: Finish Breakpoints in Python. (line 14) d61293 2 a61295 1 * flush_i_cache: Bootstrapping. (line 59) d61298 1 d61312 1 a61326 2 * frame, selecting: Selection. (line 11) * frame?: Frames In Guile. (line 22) d61344 1 d61359 1 a61359 1 * FreeProgspaceEvent.progspace: Events In Python. (line 333) d61365 1 a61366 1 * Function.invoke: Functions In Python. (line 19) a61368 2 * gdb_init_reader: Writing JIT Debug Info Readers. (line 20) a61371 8 * gdb:error: Guile Exception Handling. (line 69) * gdb:invalid-object: Guile Exception Handling. (line 72) * gdb:memory-error: Guile Exception Handling. (line 80) * gdb:pp-type-error: Guile Exception Handling. (line 84) d61447 1 a61447 1 (line 280) d61449 1 a61449 1 (line 243) d61453 1 a61453 1 (line 264) d61455 1 a61455 1 (line 376) d61457 1 a61457 1 (line 388) d61459 1 a61459 1 (line 354) d61461 1 a61461 1 (line 434) d61463 1 a61463 1 (line 405) d61465 1 a61465 1 (line 328) d61467 1 a61467 1 (line 369) d61469 1 a61469 1 (line 336) d61471 1 a61471 1 (line 415) d61473 1 a61473 1 (line 322) d61483 1 a61484 1 * gdb.FrameDecorator: Frame Decorator API. (line 25) d61517 3 a61543 3 * gdb.Parameter: Parameters In Python. (line 6) * gdb.parameter: Basic Python. (line 85) d61651 1 a61651 1 (line 204) d61653 1 a61653 1 (line 220) d61655 1 a61655 1 (line 201) d61657 1 a61657 1 (line 207) d61672 9 a61680 1 * GdbExitingEvent.exit_code: Events In Python. (line 271) d61682 2 d61689 1 a61689 1 (line 169) d61744 1 a61746 1 * Inferior.threads: Inferiors In Python. (line 76) d61754 1 a61754 1 * InferiorDeletedEvent.inferior: Events In Python. (line 246) d61789 1 a61789 1 * info copying: Help. (line 174) d61801 1 a61803 1 * info frame, show the source language: Show. (line 15) d61844 1 a61844 1 * info set: Help. (line 157) d61873 1 a61873 1 * info warranty: Help. (line 178) d61923 1 a61923 1 (line 174) d62043 1 a62043 1 (line 209) d62287 2 a62288 2 * MemoryChangedEvent.address: Events In Python. (line 193) * MemoryChangedEvent.length: Events In Python. (line 196) a62298 2 * MICommand.__init__: GDB/MI Commands In Python. (line 10) d62305 6 a62314 4 * MissingDebugHandler.enabled: Missing Debug Info In Python. (line 100) * MissingDebugHandler.name: Missing Debug Info In Python. (line 96) d62324 1 a62324 1 * NewInferiorEvent.inferior: Events In Python. (line 235) d62326 2 a62327 2 * NewProgspaceEvent.progspace: Events In Python. (line 319) * NewThreadEvent.inferior_thread: Events In Python. (line 254) d62330 2 a62334 2 * next&: Background Execution. (line 34) a62352 1 * objfile?: Objfiles In Guile. (line 17) d62366 1 d62382 17 d62401 1 a62401 1 * PARAM_AUTO_BOOLEAN <1>: Parameters In Guile. (line 121) d62404 1 a62404 1 * PARAM_BOOLEAN <1>: Parameters In Guile. (line 117) d62407 1 a62407 1 * PARAM_ENUM <1>: Parameters In Guile. (line 159) d62410 1 a62410 1 * PARAM_FILENAME <1>: Parameters In Guile. (line 155) d62415 1 a62415 1 * PARAM_OPTIONAL_FILENAME <1>: Parameters In Guile. (line 152) d62418 1 a62418 1 * PARAM_STRING <1>: Parameters In Guile. (line 142) d62421 1 a62421 1 * PARAM_STRING_NOESCAPE <1>: Parameters In Guile. (line 148) d62424 1 a62424 1 * PARAM_UINTEGER <1>: Parameters In Guile. (line 126) d62427 1 a62427 1 * PARAM_ZINTEGER <1>: Parameters In Guile. (line 131) d62430 1 a62430 1 * PARAM_ZUINTEGER <1>: Parameters In Guile. (line 134) d62433 1 a62433 18 * PARAM_ZUINTEGER_UNLIMITED <1>: Parameters In Guile. (line 137) * Parameter: Parameters In Python. (line 6) * Parameter <1>: Parameters In Guile. (line 6) * parameter-value: Parameters In Guile. (line 104) * parameter?: Parameters In Guile. (line 100) * Parameter.__init__: Parameters In Python. (line 18) * Parameter.get_set_string: Parameters In Python. (line 96) * Parameter.get_show_string: Parameters In Python. (line 126) * Parameter.set_doc: Parameters In Python. (line 56) * Parameter.show_doc: Parameters In Python. (line 72) * Parameter.value: Parameters In Python. (line 88) a62483 5 * pretty_printer.child: Pretty Printing API. (line 116) * pretty_printer.children: Pretty Printing API. (line 24) * pretty_printer.display_hint: Pretty Printing API. (line 46) * pretty_printer.num_children: Pretty Printing API. (line 109) * pretty_printer.to_string: Pretty Printing API. (line 78) d62490 5 a62512 1 * progspace?: Progspaces In Guile. (line 17) d62527 2 a62530 2 * Progspace.objfiles: Progspaces In Python. (line 105) d62539 1 d62555 1 a62556 1 * quit annotation: Errors. (line 6) a62659 3 * register_disassembler: Disassembly In Python. (line 451) * register_xmethod_matcher: Xmethod API. (line 82) d62663 3 a62665 3 * register-parameter!: Parameters In Guile. (line 95) * RegisterChangedEvent.frame: Events In Python. (line 203) * RegisterChangedEvent.regnum: Events In Python. (line 206) d62669 3 d62678 1 a62678 1 (line 158) d62732 1 a62732 1 * set: Help. (line 145) d62847 1 a62847 1 * set follow-exec-mode: Forks. (line 104) d62906 1 a62906 1 (line 188) a63000 1 * set_debug_traps: Stub Contents. (line 9) d63025 1 a63025 1 * set-parameter-value!: Parameters In Guile. (line 108) d63031 1 d63037 1 a63037 1 * show: Help. (line 150) d63090 1 a63090 1 * show configuration: Help. (line 183) d63093 1 a63093 1 * show copying: Help. (line 174) d63189 1 a63189 1 (line 196) d63258 2 a63259 2 * show version: Help. (line 164) * show warranty: Help. (line 178) d63335 1 a63335 1 (line 376) d63337 1 a63337 1 (line 388) d63339 1 a63339 1 (line 354) d63341 1 a63341 1 (line 434) d63343 1 a63343 1 (line 405) d63345 1 a63345 1 (line 328) d63347 1 a63347 1 (line 369) d63349 1 a63349 1 (line 336) d63351 1 a63351 1 (line 415) d63353 31 a63383 1 (line 322) d63385 1 a63387 1 * SYMBOL_FUNCTIONS_DOMAIN: Symbols In Guile. (line 147) d63423 1 a63425 1 * SYMBOL_TYPES_DOMAIN: Symbols In Guile. (line 150) d63428 1 a63430 41 * SYMBOL_VARIABLES_DOMAIN: Symbols In Guile. (line 143) * symbol-addr-class: Symbols In Guile. (line 48) * symbol-argument?: Symbols In Guile. (line 58) * symbol-constant?: Symbols In Guile. (line 62) * symbol-file: Files. (line 51) * symbol-function?: Symbols In Guile. (line 65) * symbol-line: Symbols In Guile. (line 32) * symbol-linkage-name: Symbols In Guile. (line 39) * symbol-name: Symbols In Guile. (line 36) * symbol-needs-frame?: Symbols In Guile. (line 53) * symbol-print-name: Symbols In Guile. (line 43) * symbol-symtab: Symbols In Guile. (line 28) * symbol-type: Symbols In Guile. (line 24) * symbol-valid?: Symbols In Guile. (line 17) * symbol-value: Symbols In Guile. (line 72) * symbol-variable?: Symbols In Guile. (line 69) * symbol?: Symbols In Guile. (line 13) * Symbol.addr_class: Symbols In Python. (line 119) * Symbol.is_argument: Symbols In Python. (line 129) * Symbol.is_constant: Symbols In Python. (line 132) * Symbol.is_function: Symbols In Python. (line 135) * Symbol.is_valid: Symbols In Python. (line 145) * Symbol.is_variable: Symbols In Python. (line 138) * Symbol.line: Symbols In Python. (line 102) * Symbol.linkage_name: Symbols In Python. (line 110) * Symbol.name: Symbols In Python. (line 106) * Symbol.needs_frame: Symbols In Python. (line 124) * Symbol.print_name: Symbols In Python. (line 114) * Symbol.symtab: Symbols In Python. (line 97) * Symbol.type: Symbols In Python. (line 92) * Symbol.value: Symbols In Python. (line 152) * Symtab_and_line.is_valid: Symbol Tables In Python. (line 34) * Symtab_and_line.last: Symbol Tables In Python. (line 24) * Symtab_and_line.line: Symbol Tables In Python. (line 28) * Symtab_and_line.pc: Symbol Tables In Python. (line 20) * Symtab_and_line.symtab: Symbol Tables In Python. (line 16) a63442 2 * symtab?: Symbol Tables In Guile. (line 17) d63459 12 d63514 1 a63514 1 * ThreadExitedEvent.inferior_thread: Events In Python. (line 262) d63552 45 a63656 45 * type-array: Types In Guile. (line 52) * type-code: Types In Guile. (line 25) * type-const: Types In Guile. (line 99) * type-field: Types In Guile. (line 129) * type-fields: Types In Guile. (line 115) * type-has-field-deep?: Guile Types Module. (line 32) * type-has-field?: Types In Guile. (line 142) * type-name: Types In Guile. (line 34) * type-num-fields: Types In Guile. (line 112) * type-pointer: Types In Guile. (line 73) * type-print-name: Types In Guile. (line 38) * type-range: Types In Guile. (line 77) * type-reference: Types In Guile. (line 81) * type-sizeof: Types In Guile. (line 43) * type-strip-typedefs: Types In Guile. (line 48) * type-tag: Types In Guile. (line 29) * type-target: Types In Guile. (line 85) * type-unqualified: Types In Guile. (line 107) * type-vector: Types In Guile. (line 60) * type-volatile: Types In Guile. (line 103) * type?: Types In Guile. (line 11) * Type.alignof: Types In Python. (line 35) * Type.array: Types In Python. (line 176) * Type.code: Types In Python. (line 41) * Type.const: Types In Python. (line 197) * Type.dynamic: Types In Python. (line 45) * Type.fields: Types In Python. (line 115) * Type.is_array_like: Types In Python. (line 99) * Type.is_scalar: Types In Python. (line 86) * Type.is_signed: Types In Python. (line 91) * Type.is_string_like: Types In Python. (line 108) * Type.name: Types In Python. (line 65) * Type.objfile: Types In Python. (line 82) * Type.optimized_out: Types In Python. (line 254) * Type.pointer: Types In Python. (line 220) * Type.range: Types In Python. (line 210) * Type.reference: Types In Python. (line 216) * Type.sizeof: Types In Python. (line 69) * Type.strip_typedefs: Types In Python. (line 224) * Type.tag: Types In Python. (line 76) * Type.target: Types In Python. (line 228) * Type.template_argument: Types In Python. (line 242) * Type.unqualified: Types In Python. (line 205) * Type.vector: Types In Python. (line 184) * Type.volatile: Types In Python. (line 201) a63751 6 * value?: Values From Inferior In Guile. (line 41) * Value.__init__: Values From Inferior. (line 126) * Value.__init__ <1>: Values From Inferior. (line 160) d63778 2 a63781 2 * Value.referenced_value: Values From Inferior. (line 234) d63790 5 a63795 1 * value<=?: Arithmetic In Guile. (line 57) d63797 1 d63799 2 a63800 1 * value>=?: Arithmetic In Guile. (line 61) d63846 1 a63847 2 * XMethodMatcher.match: Xmethod API. (line 47) * XMethodWorker.__call__: Xmethod API. (line 73) d63850 1 d63863 872 a64734 872 Node: Top1703 Node: Summary5336 Node: Free Software7205 Node: Free Documentation7950 Node: Contributors12884 Node: Sample Session21919 Node: Invocation28988 Node: Invoking GDB29559 Node: File Options32022 Ref: --readnever35820 Node: Mode Options36294 Ref: -nx36521 Ref: -nh36641 Node: Startup43654 Ref: Option -init-eval-command44895 Node: Initialization Files46711 Ref: System Wide Init Files50428 Ref: Home Directory Init File51745 Ref: Init File in the Current Directory during Startup52952 Ref: Initialization Files-Footnote-153703 Ref: Initialization Files-Footnote-253816 Node: Quitting GDB53929 Node: Shell Commands54907 Ref: pipe56084 Node: Logging Output57650 Node: Commands58813 Node: Command Syntax59629 Node: Command Settings61853 Node: Completion64942 Ref: Completion-Footnote-172445 Node: Filename Arguments72605 Node: Command Options75088 Node: Help77590 Node: Running85364 Node: Compilation86617 Node: Starting88736 Ref: set exec-wrapper94682 Ref: set startup-with-shell95811 Ref: set auto-connect-native-target96908 Node: Arguments101484 Node: Environment102805 Ref: set environment104747 Ref: unset environment105957 Node: Working Directory107011 Ref: set cwd command107591 Ref: cd command108579 Node: Input/Output109293 Node: Attach111421 Ref: set exec-file-mismatch112674 Node: Kill Process114882 Node: Inferiors Connections and Programs115891 Ref: add_inferior_cli120919 Ref: remove_inferiors_cli122985 Node: Inferior-Specific Breakpoints127057 Node: Threads128806 Ref: thread numbers130983 Ref: thread ID lists131885 Ref: global thread numbers132969 Ref: info_threads134524 Ref: thread apply all137230 Ref: set libthread-db-search-path142260 Node: Forks144582 Node: Checkpoint/Restart151384 Ref: Checkpoint/Restart-Footnote-1155968 Node: Stopping156003 Node: Breakpoints157319 Node: Set Breaks160620 Node: Set Watchpoints184919 Node: Set Catchpoints194597 Ref: catch syscall200245 Node: Delete Breaks208126 Node: Disabling210908 Node: Conditions214405 Node: Break Commands220427 Node: Dynamic Printf224120 Node: Save Breakpoints229324 Node: Static Probe Points230515 Ref: enable probes233143 Ref: Static Probe Points-Footnote-1234805 Ref: Static Probe Points-Footnote-2234969 Node: Error in Breakpoints235109 Node: Breakpoint-related Warnings235845 Node: Continuing and Stepping238172 Ref: range stepping248332 Node: Skipping Over Functions and Files249444 Node: Signals255542 Ref: stepping and signal handlers260298 Ref: stepping into signal handlers261126 Ref: extra signal information262387 Node: Thread Stops264885 Node: All-Stop Mode266028 Ref: set scheduler-locking267525 Node: Non-Stop Mode270486 Node: Background Execution273955 Node: Thread-Specific Breakpoints276251 Node: Interrupted System Calls278528 Node: Observer Mode280046 Node: Reverse Execution283654 Ref: Reverse Execution-Footnote-1288680 Ref: Reverse Execution-Footnote-2289307 Node: Process Record and Replay289357 Node: Stack311455 Node: Frames313088 Node: Backtrace315470 Ref: backtrace-command315807 Ref: set backtrace past-main322446 Ref: set backtrace past-entry322790 Ref: set backtrace limit323381 Ref: Backtrace-Footnote-1324033 Node: Selection324225 Node: Frame Info329120 Node: Frame Apply333658 Node: Frame Filter Management338256 Ref: disable frame-filter all338788 Node: Source343168 Node: List344294 Node: Location Specifications348070 Node: Linespec Locations352716 Node: Explicit Locations356230 Node: Address Locations359573 Node: Edit361367 Ref: Edit-Footnote-1363106 Node: Search363345 Node: Source Path364185 Ref: set substitute-path373477 Node: Machine Code375753 Ref: disassemble377815 Node: Disable Reading Source388023 Node: Data388805 Ref: print options389668 Node: Expressions400978 Node: Ambiguous Expressions403113 Node: Variables406403 Node: Arrays413093 Node: Output Formats415664 Ref: Output Formats-Footnote-1419341 Node: Memory419510 Ref: addressable memory unit426793 Node: Memory Tagging428311 Node: Auto Display431030 Node: Print Settings435728 Ref: set print address436026 Ref: set print symbol439800 Ref: set print array440300 Ref: set print array-indexes440644 Ref: set print nibbles441146 Ref: set print characters441721 Ref: set print elements442832 Ref: set print frame-arguments443992 Ref: set print raw-frame-arguments446217 Ref: set print entry-values446645 Ref: set print frame-info451096 Ref: set print repeats452846 Ref: set print max-depth453508 Ref: set print memory-tag-violations455272 Ref: set print null-stop455715 Ref: set print pretty456047 Ref: set print raw-values456646 Ref: set print union457691 Ref: set print object460061 Ref: set print static-members460871 Ref: set print vtbl461580 Node: Pretty Printing461988 Node: Pretty-Printer Introduction462504 Node: Pretty-Printer Example464279 Node: Pretty-Printer Commands465067 Node: Value History468007 Node: Convenience Vars470549 Node: Convenience Funs478603 Ref: $_shell convenience function483625 Node: Registers489944 Ref: info_registers_reggroup490617 Ref: standard registers491188 Ref: Registers-Footnote-1496199 Node: Floating Point Hardware496602 Node: Vector Unit497142 Node: OS Information497533 Ref: linux info os infotypes499577 Node: Memory Region Attributes504212 Node: Dump/Restore Files508968 Node: Core File Generation511451 Ref: set use-coredump-filter513154 Ref: set dump-excluded-mappings514658 Node: Character Sets514968 Node: Caching Target Data521453 Ref: Caching Target Data-Footnote-1524421 Node: Searching Memory524659 Node: Value Sizes527854 Ref: set max-value-size528281 Node: Optimized Code529534 Node: Inline Functions531227 Node: Tail Call Frames533902 Ref: set debug entry-values536128 Node: Macros540281 Ref: Macros-Footnote-1547991 Node: Tracepoints548152 Node: Set Tracepoints550234 Node: Create and Delete Tracepoints553200 Node: Enable and Disable Tracepoints559791 Node: Tracepoint Passcounts561051 Node: Tracepoint Conditions562474 Node: Trace State Variables564184 Node: Tracepoint Actions566419 Node: Listing Tracepoints573400 Node: Listing Static Tracepoint Markers575126 Node: Starting and Stopping Trace Experiments576986 Ref: disconnected tracing578743 Node: Tracepoint Restrictions583263 Node: Analyze Collected Data587088 Node: tfind588414 Node: tdump592996 Node: save tracepoints595543 Node: Tracepoint Variables596059 Node: Trace Files597227 Node: Overlays599647 Node: How Overlays Work600371 Ref: A code overlay602910 Node: Overlay Commands606389 Node: Automatic Overlay Debugging610663 Node: Overlay Sample Program612838 Node: Languages614639 Node: Setting615826 Node: Filenames617547 Node: Manually618430 Node: Automatically619683 Node: Show620756 Ref: show language621048 Node: Checks622102 Node: Type Checking623111 Node: Range Checking624964 Node: Supported Languages627392 Node: C628741 Node: C Operators629713 Node: C Constants634336 Node: C Plus Plus Expressions637357 Node: C Defaults640749 Node: C Checks641433 Node: Debugging C641993 Node: Debugging C Plus Plus642513 Node: Decimal Floating Point648235 Node: D649525 Node: Go649783 Node: Objective-C650921 Node: Method Names in Commands651384 Node: The Print Command with Objective-C653133 Node: OpenCL C653800 Node: OpenCL C Datatypes654075 Node: OpenCL C Expressions654458 Node: OpenCL C Operators654815 Node: Fortran655047 Node: Fortran Types656042 Node: Fortran Operators658155 Node: Fortran Intrinsics659244 Node: Special Fortran Commands661984 Node: Pascal663409 Node: Rust663924 Node: Modula-2667140 Node: M2 Operators668121 Node: Built-In Func/Proc671361 Node: M2 Constants674371 Node: M2 Types676032 Node: M2 Defaults679282 Node: Deviations679891 Node: M2 Checks681008 Node: M2 Scope681833 Node: GDB/M2682881 Node: Ada683846 Node: Ada Mode Intro685150 Node: Omissions from Ada686662 Node: Additions to Ada691056 Node: Overloading support for Ada695509 Node: Stopping Before Main Program697169 Node: Ada Exceptions697728 Node: Ada Tasks698939 Node: Ada Tasks and Core Files707517 Node: Ravenscar Profile708368 Node: Ada Source Character Set710575 Node: Ada Glitches711384 Node: Unsupported Languages715490 Node: Symbols716188 Ref: quoting names716791 Node: Altering752698 Node: Assignment753736 Node: Jumping756954 Node: Signaling759846 Node: Returning762855 Node: Calling766266 Ref: stack unwind settings767889 Ref: set unwind-on-timeout769217 Node: Patching776711 Node: Compiling and Injecting Code777861 Ref: set debug compile781576 Ref: set debug compile-cplus-types781834 Node: GDB Files792192 Node: Files793040 Ref: Shared Libraries808120 Ref: Files-Footnote-1820615 Node: File Caching820748 Node: Separate Debug Files821934 Ref: build ID823199 Ref: debug-file-directory825751 Node: MiniDebugInfo834596 Node: Index Files837059 Node: Debug Names841249 Node: Symbol Errors842615 Node: Data Files846299 Node: Targets847283 Node: Active Targets848815 Node: Target Commands849905 Ref: load854466 Ref: flash-erase855687 Node: Byte Order855747 Node: Remote Debugging857226 Node: Connecting858497 Ref: --multi Option in Types of Remote Connnections860791 Ref: Attaching in Types of Remote Connections862286 Ref: Host and target files863198 Node: File Transfer872092 Node: Server873047 Ref: Running gdbserver874679 Ref: Attaching to a program876997 Ref: Other Command-Line Arguments for gdbserver879630 Ref: Monitor Commands for gdbserver884160 Ref: Server-Footnote-1890445 Node: Remote Configuration890569 Ref: set remotebreak891873 Ref: set remote hardware-watchpoint-limit893423 Ref: set remote hardware-breakpoint-limit893423 Ref: set remote hardware-watchpoint-length-limit893945 Ref: set remote exec-file894420 Node: Remote Stub908681 Node: Stub Contents911640 Node: Bootstrapping913795 Node: Debug Session917674 Node: Configurations919759 Node: Native920528 Node: BSD libkvm Interface921154 Node: Process Information922230 Node: DJGPP Native927994 Node: Cygwin Native934719 Node: Non-debug DLL Symbols939816 Node: Hurd Native944083 Node: Darwin949591 Node: FreeBSD950900 Node: Embedded OS951628 Node: Embedded Processors952039 Node: ARC953085 Node: ARM953644 Node: BPF956686 Node: M68K957182 Node: MicroBlaze957355 Node: MIPS Embedded958848 Node: OpenRISC 1000960193 Node: PowerPC Embedded961119 Node: AVR964590 Node: CRIS964966 Node: Super-H966000 Node: Architectures967087 Node: AArch64967527 Ref: vl968858 Ref: vq968971 Ref: vg969083 Ref: AArch64 SME969130 Ref: svl970893 Ref: svq971053 Ref: svg971167 Ref: aarch64 sme svcr971961 Ref: AArch64 SME2977194 Ref: AArch64 PAC978714 Node: x86981383 Ref: x86-Footnote-1986348 Node: Alpha986434 Node: MIPS986566 Node: HPPA990576 Node: PowerPC991110 Node: Nios II991894 Node: Sparc64992307 Node: S12Z994691 Node: AMD GPU995004 Ref: AMD GPU Signals999162 Ref: AMD GPU Attaching Restrictions1004939 Node: Controlling GDB1005667 Node: Prompt1006614 Node: Editing1008372 Node: Command History1009734 Node: Screen Size1015116 Node: Output Styling1017224 Ref: style_disassembler_enabled1019067 Node: Numbers1027363 Node: ABI1029409 Node: Auto-loading1032702 Ref: set auto-load off1033780 Ref: show auto-load1034432 Ref: info auto-load1035219 Node: Init File in the Current Directory1038519 Ref: set auto-load local-gdbinit1039102 Ref: show auto-load local-gdbinit1039288 Ref: info auto-load local-gdbinit1039456 Node: libthread_db.so.1 file1039608 Ref: set auto-load libthread-db1040571 Ref: show auto-load libthread-db1040706 Ref: info auto-load libthread-db1040847 Node: Auto-loading safe path1041035 Ref: set auto-load safe-path1042340 Ref: show auto-load safe-path1043107 Ref: add-auto-load-safe-path1043234 Node: Auto-loading verbose mode1046209 Ref: set debug auto-load1047372 Ref: show debug auto-load1047477 Node: Messages/Warnings1047603 Ref: confirmation requests1049073 Node: Debugging Output1050313 Ref: set debug amd-dbgapi-lib1051732 Ref: set debug amd-dbgapi1052393 Node: Other Misc Settings1062982 Node: Extending GDB1066216 Node: Sequences1068061 Node: Define1068723 Node: Hooks1074708 Node: Command Files1077138 Node: Output1082375 Ref: %V Format Specifier1087399 Ref: eval1088316 Node: Auto-loading sequences1088482 Ref: set auto-load gdb-scripts1088985 Ref: show auto-load gdb-scripts1089113 Ref: info auto-load gdb-scripts1089247 Node: Aliases1089482 Node: Command aliases default args1093021 Ref: Command aliases default args-Footnote-11096842 Node: Python1096996 Node: Python Commands1098187 Ref: set_python_print_stack1099614 Ref: Python Commands-Footnote-11102832 Node: Python API1102926 Node: Basic Python1106101 Ref: prompt_hook1118461 Ref: gdb_architecture_names1119071 Ref: gdbpy_connections1119422 Node: Threading in GDB1122127 Node: Exception Handling1124726 Node: Values From Inferior1127644 Ref: Value.assign1134895 Node: Types In Python1148819 Ref: Type.is_array_like1152973 Node: Pretty Printing API1162136 Node: Selecting Pretty-Printers1168856 Node: Writing a Pretty-Printer1171643 Node: Type Printing API1177195 Node: Frame Filter API1179859 Node: Frame Decorator API1187317 Ref: frame_args1191140 Node: Writing a Frame Filter1194540 Node: Unwinding Frames in Python1206150 Ref: gdb.PendingFrame.create_unwind_info1209491 Ref: gdb.unwinder.FrameId1214512 Ref: Managing Registered Unwinders1217902 Node: Xmethods In Python1219218 Node: Xmethod API1222142 Node: Writing an Xmethod1226090 Node: Inferiors In Python1232018 Ref: gdbpy_inferior_connection1232989 Ref: gdbpy_inferior_read_memory1235667 Ref: choosing attribute names1238115 Node: Events In Python1239254 Node: Threads In Python1253866 Ref: inferior_thread_ptid1255420 Node: Recordings In Python1259424 Node: CLI Commands In Python1266881 Node: GDB/MI Commands In Python1276930 Node: GDB/MI Notifications In Python1283713 Node: Parameters In Python1285422 Node: Functions In Python1294382 Node: Progspaces In Python1296631 Node: Objfiles In Python1303752 Node: Frames In Python1310916 Ref: gdbpy_frame_read_register1317368 Node: Blocks In Python1319728 Node: Symbols In Python1324491 Node: Symbol Tables In Python1335600 Node: Line Tables In Python1338901 Node: Breakpoints In Python1341812 Ref: python_breakpoint_thread1348647 Ref: python_breakpoint_inferior1349123 Node: Finish Breakpoints in Python1355769 Node: Lazy Strings In Python1357935 Node: Architectures In Python1360223 Ref: gdbpy_architecture_name1360692 Ref: gdbpy_architecture_registers1363015 Ref: gdbpy_architecture_reggroups1363344 Node: Registers In Python1363551 Node: Connections In Python1365893 Node: TUI Windows In Python1370885 Ref: python-window-click1375810 Node: Disassembly In Python1376304 Ref: DisassembleInfo Class1376700 Ref: Disassembler Class1382533 Ref: DisassemblerResult Class1384948 Ref: Disassembler Styling Parts1388694 Ref: Disassembler Style Constants1392099 Ref: builtin_disassemble1400248 Node: Missing Debug Info In Python1403927 Node: Python Auto-loading1410010 Ref: set auto-load python-scripts1410651 Ref: show auto-load python-scripts1410755 Ref: info auto-load python-scripts1410865 Node: Python modules1412019 Node: gdb.printing1412405 Node: gdb.types1413884 Node: gdb.prompt1416964 Node: Guile1418608 Node: Guile Introduction1419271 Node: Guile Commands1420117 Node: Guile API1422047 Node: Basic Guile1424060 Node: Guile Configuration1429866 Node: GDB Scheme Data Types1430850 Node: Guile Exception Handling1432810 Node: Values From Inferior In Guile1436944 Node: Arithmetic In Guile1453554 Node: Types In Guile1455197 Ref: Fields of a type in Guile1463742 Node: Guile Pretty Printing API1465194 Node: Selecting Guile Pretty-Printers1471090 Node: Writing a Guile Pretty-Printer1473528 Node: Commands In Guile1478749 Node: Parameters In Guile1489892 Ref: Parameters In Guile-Footnote-11497173 Node: Progspaces In Guile1497289 Node: Objfiles In Guile1499973 Node: Frames In Guile1502314 Node: Blocks In Guile1509057 Node: Symbols In Guile1513997 Node: Symbol Tables In Guile1522613 Node: Breakpoints In Guile1525684 Node: Lazy Strings In Guile1537133 Node: Architectures In Guile1539496 Node: Disassembly In Guile1544031 Node: I/O Ports in Guile1547257 Node: Memory Ports in Guile1547821 Node: Iterators In Guile1551756 Node: Guile Auto-loading1556133 Ref: set auto-load guile-scripts1556768 Ref: show auto-load guile-scripts1556870 Ref: info auto-load guile-scripts1556978 Node: Guile Modules1557953 Node: Guile Printing Module1558275 Node: Guile Types Module1559110 Node: Auto-loading extensions1560423 Node: objfile-gdbdotext file1561908 Ref: set auto-load scripts-directory1563638 Ref: with-auto-load-dir1564030 Ref: show auto-load scripts-directory1564897 Ref: add-auto-load-scripts-directory1564981 Node: dotdebug_gdb_scripts section1565465 Node: Which flavor to choose?1569287 Node: Multiple Extension Languages1571156 Node: Interpreters1572204 Node: TUI1575754 Node: TUI Overview1576822 Node: TUI Keys1579635 Node: TUI Single Key Mode1582446 Node: TUI Mouse Support1583884 Node: TUI Commands1584926 Ref: info_win_command1585905 Node: TUI Configuration1592054 Ref: tui-mouse-events1593889 Node: Emacs1594481 Node: GDB/MI1600046 Node: GDB/MI General Design1602875 Node: Context management1605401 Node: Asynchronous and non-stop modes1609252 Node: Thread groups1612275 Node: GDB/MI Command Syntax1614601 Node: GDB/MI Input Syntax1614844 Node: GDB/MI Output Syntax1616484 Node: GDB/MI Compatibility with CLI1620295 Node: GDB/MI Development and Front Ends1621052 Node: GDB/MI Output Records1625535 Node: GDB/MI Result Records1625941 Node: GDB/MI Stream Records1627347 Node: GDB/MI Async Records1628636 Node: GDB/MI Breakpoint Information1639442 Node: GDB/MI Frame Information1645528 Node: GDB/MI Thread Information1646838 Node: GDB/MI Ada Exception Information1648348 Node: GDB/MI Simple Examples1648910 Node: GDB/MI Command Description Format1651162 Node: GDB/MI Breakpoint Commands1652042 Ref: -break-insert1659400 Node: GDB/MI Catchpoint Commands1674290 Node: Shared Library GDB/MI Catchpoint Commands1674703 Node: Ada Exception GDB/MI Catchpoint Commands1676401 Node: C++ Exception GDB/MI Catchpoint Commands1680035 Node: GDB/MI Program Context1684099 Node: GDB/MI Thread Commands1688427 Node: GDB/MI Ada Tasking Commands1691768 Node: GDB/MI Program Execution1694084 Node: GDB/MI Stack Manipulation1707017 Ref: -stack-list-arguments1708961 Ref: -stack-list-frames1712831 Ref: -stack-list-locals1717149 Ref: -stack-list-variables1718746 Node: GDB/MI Variable Objects1720336 Ref: -var-set-format1730488 Ref: -var-list-children1731884 Ref: -var-update1740936 Ref: -var-set-frozen1743949 Ref: -var-set-update-range1744766 Ref: -var-set-visualizer1745307 Node: GDB/MI Data Manipulation1746890 Node: GDB/MI Tracepoint Commands1770374 Node: GDB/MI Symbol Query1782722 Ref: -symbol-info-functions1782916 Ref: -symbol-info-module-functions1787439 Ref: -symbol-info-module-variables1790441 Ref: -symbol-info-modules1794196 Ref: -symbol-info-types1796120 Ref: -symbol-info-variables1798129 Node: GDB/MI File Commands1803256 Node: GDB/MI Target Manipulation1813235 Node: GDB/MI File Transfer Commands1819989 Node: GDB/MI Ada Exceptions Commands1821336 Node: GDB/MI Support Commands1822705 Node: GDB/MI Miscellaneous Commands1828003 Ref: -interpreter-exec1840416 Node: Annotations1844448 Node: Annotations Overview1845379 Node: Server Prefix1847890 Node: Prompting1848640 Node: Errors1850201 Node: Invalidation1851109 Node: Annotations for Running1851600 Node: Source Annotations1853190 Node: Debugger Adapter Protocol1854131 Node: JIT Interface1858447 Node: Declarations1860265 Node: Registering Code1861652 Node: Unregistering Code1862650 Node: Custom Debug Info1863299 Node: Using JIT Debug Info Readers1864611 Node: Writing JIT Debug Info Readers1865655 Node: In-Process Agent1867922 Ref: Control Agent1869869 Node: In-Process Agent Protocol1870748 Node: IPA Protocol Objects1871539 Ref: agent expression object1872541 Ref: tracepoint action object1872746 Ref: tracepoint object1872826 Node: IPA Protocol Commands1875360 Node: GDB Bugs1876796 Node: Bug Criteria1877528 Node: Bug Reporting1878413 Node: Command Line Editing1885450 Node: Introduction and Notation1886102 Node: Readline Interaction1887747 Node: Readline Bare Essentials1888936 Node: Readline Movement Commands1890749 Node: Readline Killing Commands1891747 Node: Readline Arguments1893723 Node: Searching1894781 Node: Readline Init File1896971 Node: Readline Init File Syntax1898142 Node: Conditional Init Constructs1919213 Node: Sample Init File1923579 Node: Bindable Readline Commands1926701 Node: Commands For Moving1927769 Node: Commands For History1929569 Node: Commands For Text1934413 Node: Commands For Killing1938205 Node: Numeric Arguments1941012 Node: Commands For Completion1942165 Node: Keyboard Macros1944195 Node: Miscellaneous Commands1944896 Node: Readline vi Mode1948931 Node: Using History Interactively1949893 Node: History Interaction1950408 Node: Event Designators1952324 Node: Word Designators1953644 Node: Modifiers1955526 Node: In Memoriam1957153 Node: Formatting Documentation1958044 Ref: Formatting Documentation-Footnote-11961452 Node: Installing GDB1961522 Node: Requirements1962098 Ref: MPFR1963778 Ref: Expat1965434 Node: Running Configure1968397 Node: Separate Objdir1971259 Node: Config Names1974283 Node: Configure Options1975766 Node: System-wide configuration1985173 Node: System-wide Configuration Scripts1987782 Node: Maintenance Commands1989002 Ref: maint info breakpoints1990765 Ref: maint info python-disassemblers1993672 Ref: maint packet2001004 Ref: maint check libthread-db2002992 Ref: maint_libopcodes_styling2021610 Node: Remote Protocol2027333 Node: Overview2028046 Ref: Binary Data2030668 Node: Standard Replies2034032 Ref: textual error reply2034885 Node: Packets2034991 Ref: thread-id syntax2035911 Ref: extended mode2037404 Ref: ? packet2037674 Ref: bc2039194 Ref: bs2039408 Ref: read registers packet2041038 Ref: cycle step packet2043445 Ref: write register packet2046221 Ref: step with signal packet2047209 Ref: vCont packet2048661 Ref: vCtrlC packet2051956 Ref: vKill packet2054365 Ref: X packet2055893 Ref: insert breakpoint or watchpoint packet2056243 Node: Stop Reply Packets2060370 Ref: swbreak stop reason2063779 Ref: thread clone event2067392 Ref: thread create event2067780 Ref: thread exit event2069007 Node: General Query Packets2071323 Ref: qCRC packet2074263 Ref: QEnvironmentHexEncoded2077123 Ref: QEnvironmentUnset2078377 Ref: QEnvironmentReset2079341 Ref: QSetWorkingDir packet2080309 Ref: qMemTags2084847 Ref: qIsAddressTagged2085601 Ref: QMemTags2086112 Ref: QNonStop2089291 Ref: QCatchSyscalls2089798 Ref: QPassSignals2091211 Ref: QProgramSignals2092245 Ref: QThreadEvents2093628 Ref: QThreadOptions2094760 Ref: qSearch memory2098806 Ref: QStartNoAckMode2099125 Ref: qSupported2099573 Ref: multiprocess extensions2115881 Ref: install tracepoint in tracing2117991 Ref: qThreadExtraInfo2122566 Ref: qXfer read2123796 Ref: qXfer auxiliary vector read2125053 Ref: qXfer btrace read2125413 Ref: qXfer btrace-conf read2126502 Ref: qXfer executable filename read2126861 Ref: qXfer target description read2127484 Ref: qXfer library list read2127934 Ref: qXfer svr4 library list read2128602 Ref: qXfer memory map read2130925 Ref: qXfer sdata read2131328 Ref: qXfer siginfo read2131806 Ref: qXfer threads read2132214 Ref: qXfer traceframe info read2132629 Ref: qXfer unwind info block2133059 Ref: qXfer fdpic loadmap read2133297 Ref: qXfer osdata read2133745 Ref: qXfer write2133907 Ref: qXfer siginfo write2134637 Ref: General Query Packets-Footnote-12136968 Node: Architecture-Specific Protocol Details2137307 Node: ARM-Specific Protocol Details2137816 Node: ARM Breakpoint Kinds2138089 Node: ARM Memory Tag Types2138457 Node: MIPS-Specific Protocol Details2138764 Node: MIPS Register packet Format2139047 Node: MIPS Breakpoint Kinds2139990 Node: Tracepoint Packets2140416 Ref: QTEnable2149792 Ref: QTDisable2149992 Ref: qTfSTM2155701 Ref: qTsSTM2155701 Ref: qTSTMat2156622 Ref: QTBuffer-size2157801 Node: Host I/O Packets2159698 Node: Interrupts2165348 Ref: interrupting remote targets2165492 Node: Notification Packets2167724 Node: Remote Non-Stop2173207 Node: Packet Acknowledgment2176391 Node: Examples2178578 Node: File-I/O Remote Protocol Extension2179172 Node: File-I/O Overview2179634 Node: Protocol Basics2181873 Node: The F Request Packet2184178 Node: The F Reply Packet2185091 Node: The Ctrl-C Message2186033 Node: Console I/O2187712 Node: List of Supported Calls2188966 Node: open2189328 Node: close2191972 Node: read2192371 Node: write2192996 Node: lseek2193791 Node: rename2194707 Node: unlink2196166 Node: stat/fstat2197153 Node: gettimeofday2198082 Node: isatty2198530 Node: system2199142 Node: Protocol-specific Representation of Datatypes2200736 Node: Integral Datatypes2201113 Node: Pointer Values2201980 Node: Memory Transfer2202688 Node: struct stat2203316 Node: struct timeval2205566 Node: Constants2206087 Node: Open Flags2206536 Node: mode_t Values2206877 Node: Errno Values2207369 Node: Lseek Flags2208183 Node: Limits2208368 Node: File-I/O Examples2208728 Node: Library List Format2209828 Node: Library List Format for SVR4 Targets2212622 Node: Memory Map Format2215477 Node: Thread List Format2218019 Node: Traceframe Info Format2219067 Node: Branch Trace Format2220761 Node: Branch Trace Configuration Format2222467 Node: Agent Expressions2223669 Node: General Bytecode Design2226506 Node: Bytecode Descriptions2231436 Node: Using Agent Expressions2245294 Node: Varying Target Capabilities2247287 Node: Rationale2248468 Node: Target Descriptions2256021 Node: Retrieving Descriptions2257974 Node: Target Description Format2259087 Node: Predefined Target Types2269168 Node: Enum Target Types2270847 Node: Standard Target Features2271854 Node: AArch64 Features2273885 Node: ARC Features2284530 Ref: ARC Features-Footnote-12286495 Node: ARM Features2286528 Node: i386 Features2296591 Node: LoongArch Features2299079 Node: MicroBlaze Features2299698 Node: MIPS Features2300368 Node: M68K Features2301655 Node: NDS32 Features2302734 Node: Nios II Features2303818 Node: OpenRISC 1000 Features2304265 Node: PowerPC Features2304655 Node: RISC-V Features2309005 Node: RX Features2310940 Node: S/390 and System z Features2311354 Node: Sparc Features2313678 Node: TIC6x Features2314715 Node: Operating System Information2315328 Node: Process list2316172 Node: Trace File Format2317263 Node: Index Section Format2320565 Node: Debuginfod2329290 Node: Debuginfod Settings2330154 Ref: set debuginfod enabled2330337 Node: Man Pages2332156 Node: gdb man2332616 Node: gdbserver man2340902 Node: gcore man2349122 Node: gdbinit man2350280 Node: gdb-add-index man2351567 Ref: gdb-add-index2351676 Node: Copying2352582 Node: GNU Free Documentation License2390158 Node: Concept Index2415308 Node: Command and Variable Index2568801 @