head 1.1; branch 1.1.1; access; symbols netbsd-11-0-RC4:1.1.1.15 netbsd-11-0-RC3:1.1.1.15 netbsd-11-0-RC2:1.1.1.15 netbsd-11-0-RC1:1.1.1.15 gcc-14-3-0:1.1.1.16 perseant-exfatfs-base-20250801:1.1.1.15 netbsd-11:1.1.1.15.0.2 netbsd-11-base:1.1.1.15 gcc-12-5-0:1.1.1.15 netbsd-10-1-RELEASE:1.1.1.13 perseant-exfatfs-base-20240630:1.1.1.15 gcc-12-4-0:1.1.1.15 perseant-exfatfs:1.1.1.14.0.2 perseant-exfatfs-base:1.1.1.14 netbsd-8-3-RELEASE:1.1.1.4 netbsd-9-4-RELEASE:1.1.1.7 netbsd-10-0-RELEASE:1.1.1.13 netbsd-10-0-RC6:1.1.1.13 netbsd-10-0-RC5:1.1.1.13 netbsd-10-0-RC4:1.1.1.13 netbsd-10-0-RC3:1.1.1.13 netbsd-10-0-RC2:1.1.1.13 netbsd-10-0-RC1:1.1.1.13 gcc-12-3-0:1.1.1.14 gcc-10-5-0:1.1.1.13 netbsd-10:1.1.1.13.0.6 netbsd-10-base:1.1.1.13 netbsd-9-3-RELEASE:1.1.1.7 gcc-10-4-0:1.1.1.13 cjep_sun2x-base1:1.1.1.13 cjep_sun2x:1.1.1.13.0.4 cjep_sun2x-base:1.1.1.13 cjep_staticlib_x-base1:1.1.1.13 netbsd-9-2-RELEASE:1.1.1.7 cjep_staticlib_x:1.1.1.13.0.2 cjep_staticlib_x-base:1.1.1.13 gcc-10-3-0:1.1.1.13 netbsd-9-1-RELEASE:1.1.1.7 gcc-9-3-0:1.1.1.12 gcc-7-5-0:1.1.1.10 phil-wifi-20200421:1.1.1.9 phil-wifi-20200411:1.1.1.9 is-mlppp:1.1.1.8.0.2 is-mlppp-base:1.1.1.8 phil-wifi-20200406:1.1.1.9 netbsd-8-2-RELEASE:1.1.1.4 gcc-8-4-0:1.1.1.11 netbsd-9-0-RELEASE:1.1.1.7 netbsd-9-0-RC2:1.1.1.7 netbsd-9-0-RC1:1.1.1.7 phil-wifi-20191119:1.1.1.8 gcc-8-3-0:1.1.1.8 netbsd-9:1.1.1.7.0.2 netbsd-9-base:1.1.1.7 phil-wifi-20190609:1.1.1.7 netbsd-8-1-RELEASE:1.1.1.4 netbsd-8-1-RC1:1.1.1.4 pgoyette-compat-merge-20190127:1.1.1.5.2.2 pgoyette-compat-20190127:1.1.1.7 gcc-7-4-0:1.1.1.7 pgoyette-compat-20190118:1.1.1.6 pgoyette-compat-1226:1.1.1.6 pgoyette-compat-1126:1.1.1.6 gcc-6-5-0:1.1.1.6 pgoyette-compat-1020:1.1.1.5 pgoyette-compat-0930:1.1.1.5 pgoyette-compat-0906:1.1.1.5 netbsd-7-2-RELEASE:1.1.1.2 pgoyette-compat-0728:1.1.1.5 netbsd-8-0-RELEASE:1.1.1.4 phil-wifi:1.1.1.5.0.4 phil-wifi-base:1.1.1.5 pgoyette-compat-0625:1.1.1.5 netbsd-8-0-RC2:1.1.1.4 pgoyette-compat-0521:1.1.1.5 pgoyette-compat-0502:1.1.1.5 pgoyette-compat-0422:1.1.1.5 netbsd-8-0-RC1:1.1.1.4 pgoyette-compat-0415:1.1.1.5 pgoyette-compat-0407:1.1.1.5 pgoyette-compat-0330:1.1.1.5 pgoyette-compat-0322:1.1.1.5 pgoyette-compat-0315:1.1.1.5 netbsd-7-1-2-RELEASE:1.1.1.2 pgoyette-compat:1.1.1.5.0.2 pgoyette-compat-base:1.1.1.5 gcc-6-4-0:1.1.1.5 netbsd-7-1-1-RELEASE:1.1.1.2 gcc-5-5-0:1.1.1.4 matt-nb8-mediatek:1.1.1.4.0.12 matt-nb8-mediatek-base:1.1.1.4 perseant-stdc-iso10646:1.1.1.4.0.10 perseant-stdc-iso10646-base:1.1.1.4 netbsd-8:1.1.1.4.0.8 netbsd-8-base:1.1.1.4 prg-localcount2-base3:1.1.1.4 prg-localcount2-base2:1.1.1.4 prg-localcount2-base1:1.1.1.4 prg-localcount2:1.1.1.4.0.6 prg-localcount2-base:1.1.1.4 pgoyette-localcount-20170426:1.1.1.4 bouyer-socketcan-base1:1.1.1.4 pgoyette-localcount-20170320:1.1.1.4 netbsd-7-1:1.1.1.2.0.10 netbsd-7-1-RELEASE:1.1.1.2 netbsd-7-1-RC2:1.1.1.2 netbsd-7-nhusb-base-20170116:1.1.1.2 bouyer-socketcan:1.1.1.4.0.4 bouyer-socketcan-base:1.1.1.4 pgoyette-localcount-20170107:1.1.1.4 netbsd-7-1-RC1:1.1.1.2 pgoyette-localcount-20161104:1.1.1.4 netbsd-7-0-2-RELEASE:1.1.1.2 localcount-20160914:1.1.1.4 netbsd-7-nhusb:1.1.1.2.0.8 netbsd-7-nhusb-base:1.1.1.2 pgoyette-localcount-20160806:1.1.1.4 pgoyette-localcount-20160726:1.1.1.4 pgoyette-localcount:1.1.1.4.0.2 pgoyette-localcount-base:1.1.1.4 gcc-5-4-0:1.1.1.4 netbsd-7-0-1-RELEASE:1.1.1.2 gcc-5-3-0:1.1.1.3 netbsd-7-0:1.1.1.2.0.6 netbsd-7-0-RELEASE:1.1.1.2 gcc-4-8-5-pre-gcc-old-import:1.1.1.2 netbsd-7-0-RC3:1.1.1.2 netbsd-7-0-RC2:1.1.1.2 post-gcc-4-8-5-merge:1.1.1.2 gcc-4-8-5:1.1.1.2 netbsd-7-0-RC1:1.1.1.2 gcc-4-8-4:1.1.1.2 gcc-4-8-20141009:1.1.1.2 netbsd-6-0-6-RELEASE:1.1.1.1 netbsd-6-1-5-RELEASE:1.1.1.1 netbsd-7:1.1.1.2.0.4 netbsd-7-base:1.1.1.2 gcc-4-8-3:1.1.1.2 yamt-pagecache-base9:1.1.1.2 yamt-pagecache-tag8:1.1.1.1 netbsd-6-1-4-RELEASE:1.1.1.1 netbsd-6-0-5-RELEASE:1.1.1.1 tls-earlyentropy:1.1.1.2.0.2 tls-earlyentropy-base:1.1.1.2 riastradh-xf86-video-intel-2-7-1-pre-2-21-15:1.1.1.2 riastradh-drm2-base3:1.1.1.2 gcc-4-8-3-pre-r208254:1.1.1.2 gcc-4-8-3-pre-r206687:1.1.1.2 imported-to-gcc-old-20140227-0107:1.1.1.1 netbsd-6-1-3-RELEASE:1.1.1.1 netbsd-6-0-4-RELEASE:1.1.1.1 netbsd-6-1-2-RELEASE:1.1.1.1 netbsd-6-0-3-RELEASE:1.1.1.1 netbsd-6-1-1-RELEASE:1.1.1.1 riastradh-drm2-base2:1.1.1.1 riastradh-drm2-base1:1.1.1.1 riastradh-drm2:1.1.1.1.0.12 riastradh-drm2-base:1.1.1.1 netbsd-6-1:1.1.1.1.0.16 netbsd-6-0-2-RELEASE:1.1.1.1 netbsd-6-1-RELEASE:1.1.1.1 netbsd-6-1-RC4:1.1.1.1 netbsd-6-1-RC3:1.1.1.1 agc-symver:1.1.1.1.0.14 agc-symver-base:1.1.1.1 netbsd-6-1-RC2:1.1.1.1 netbsd-6-1-RC1:1.1.1.1 yamt-pagecache-base8:1.1.1.1 netbsd-6-0-1-RELEASE:1.1.1.1 yamt-pagecache-base7:1.1.1.1 matt-nb6-plus-nbase:1.1.1.1 yamt-pagecache-base6:1.1.1.1 netbsd-6-0:1.1.1.1.0.10 netbsd-6-0-RELEASE:1.1.1.1 gcc-4-5-4:1.1.1.1 netbsd-6-0-RC2:1.1.1.1 tls-maxphys:1.1.1.1.0.8 tls-maxphys-base:1.1.1.2 matt-nb6-plus:1.1.1.1.0.6 matt-nb6-plus-base:1.1.1.1 netbsd-6-0-RC1:1.1.1.1 yamt-pagecache-base5:1.1.1.1 yamt-pagecache-base4:1.1.1.1 netbsd-6:1.1.1.1.0.4 netbsd-6-base:1.1.1.1 yamt-pagecache-base3:1.1.1.1 yamt-pagecache-base2:1.1.1.1 yamt-pagecache:1.1.1.1.0.2 yamt-pagecache-base:1.1.1.1 gcc-4-5-3:1.1.1.1 FSF:1.1.1; locks; strict; comment @# @; 1.1 date 2011.06.21.01.24.06; author mrg; state Exp; branches 1.1.1.1; next ; 1.1.1.1 date 2011.06.21.01.24.06; author mrg; state Exp; branches 1.1.1.1.2.1 1.1.1.1.8.1; next 1.1.1.2; 1.1.1.2 date 2014.03.01.08.41.29; author mrg; state Exp; branches; next 1.1.1.3; commitid TtaB91QNTknAoYqx; 1.1.1.3 date 2016.01.24.06.05.43; author mrg; state Exp; branches; next 1.1.1.4; commitid uWWfbLp08zOK79Sy; 1.1.1.4 date 2016.06.07.05.57.45; author mrg; state Exp; branches; next 1.1.1.5; commitid KKgo7HPiSHWAPu9z; 1.1.1.5 date 2018.02.02.01.59.03; author mrg; state Exp; branches 1.1.1.5.2.1 1.1.1.5.4.1; next 1.1.1.6; commitid XNKaycqpfhzd5epA; 1.1.1.6 date 2018.11.04.00.12.37; author mrg; state Exp; branches; next 1.1.1.7; commitid bulspy67pMB6EyYA; 1.1.1.7 date 2019.01.19.10.14.11; 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revision @ text @ Chapter 3. Using
Chapter 3. Using
Prev Part I.  Introduction  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

The set of features available in the GNU C++ library is shaped by several GCC Command Options. Options that impact libstdc++ are enumerated and detailed in the table below.

By default, g++ is equivalent to g++ -std=gnu++98. The standard library also defaults to this dialect.

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98Use the 1998 ISO C++ standard plus amendments.
-std=gnu++98As directly above, with GNU extensions.
-std=c++0xUse the working draft of the upcoming ISO C++0x standard.
-std=gnu++0xAs directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthread or -pthreadsFor ISO C++0x <thread>, <future>, <mutex>, or <condition_variable>.
-fopenmpFor parallel mode.

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@ 1.1.1.1 log @initial import of GCC 4.5.3 sources. changes since 4.1 are way too numerous to review, please see http://gcc.gnu.org/gcc-4.5/changes.html (and the 4.2, 4.3 and 4.4 versions, too.) this includes the core, c++, objc and the non java/ada/fortran parts of the testsuite. @ text @@ 1.1.1.1.8.1 log @Rebase to HEAD as of a few days ago. @ text @d2 2 a3 1 Chapter 3. Using
Chapter 3. Using
Prev Part I.  d6 1 a6 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

d9 1 a9 1 several GCC d14 2 a15 2

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98Use the 1998 ISO C++ standard plus amendments.
-std=gnu++98As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthread or -pthreadsFor ISO C++11 <thread>, <future>, <mutex>, or <condition_variable>.
-fopenmpFor parallel mode.

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Make Home Headers
@ 1.1.1.1.2.1 log @sync with head. for a reference, the tree before this commit was tagged as yamt-pagecache-tag8. this commit was splitted into small chunks to avoid a limitation of cvs. ("Protocol error: too many arguments") @ text @d2 2 a3 1 Chapter 3. Using
Chapter 3. Using
Prev Part I.  d6 1 a6 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

d9 1 a9 1 several GCC d14 2 a15 2

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98Use the 1998 ISO C++ standard plus amendments.
-std=gnu++98As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthread or -pthreadsFor ISO C++11 <thread>, <future>, <mutex>, or <condition_variable>.
-fopenmpFor parallel mode.

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Make Home Headers
@ 1.1.1.2 log @import GCC 4.8 branch at r206687. highlights from: http://gcc.gnu.org/gcc-4.6/changes.html GCC now has stricter checks for invalid command-line options New -Wunused-but-set-variable and -Wunused-but-set-parameter warnings Many platforms have been obsoleted Link-time optimization improvements A new switch -fstack-usage has been added A new function attribute leaf was introduced A new warning, enabled by -Wdouble-promotion Support for selectively enabling and disabling warnings via #pragma GCC diagnostic has been added There is now experimental support for some features from the upcoming C1X revision of the ISO C standard Improved experimental support for the upcoming C++0x ISO C++ standard G++ now issues clearer diagnostics in several cases Updates for ARM, x86, MIPS, PPC/PPC64, SPARC Darwin, FreeBSD, Solaris 2, MinGW and Cygwin now all support __float128 on 32-bit and 64-bit x86 targets. [*1] highlights from: http://gcc.gnu.org/gcc-4.7/changes.html The -fconserve-space flag has been deprecated Support for a new parameter --param case-values-threshold=n was added Interprocedural and Link-time optimization improvements A new built-in, __builtin_assume_aligned, has been added A new warning option -Wunused-local-typedefs was added A new experimental command-line option -ftrack-macro-expansion was added Support for atomic operations specifying the C++11/C11 memory model has been added There is support for some more features from the C11 revision of the ISO C standard Improved experimental support for the new ISO C++ standard, C++11 Updates for ARM, x86, MIPS, PPC/PPC64, SH, SPARC, TILE* A new option (-grecord-gcc-switches) was added highlights from: http://gcc.gnu.org/gcc-4.8/changes.html GCC now uses C++ as its implementation language. This means that to build GCC from sources, you will need a C++ compiler that understands C++ 2003 DWARF4 is now the default when generating DWARF debug information A new general optimization level, -Og, has been introduced A new option -ftree-partial-pre was added The option -fconserve-space has been removed The command-line options -fipa-struct-reorg and -fipa-matrix-reorg have been removed Interprocedural and Link-time optimization improvements AddressSanitizer, a fast memory error detector, has been added [*2] A new -Wsizeof-pointer-memaccess warning has been added G++ now supports a -std=c++1y option for experimentation with features proposed for the next revision of the standard, expected around 2014 Improved experimental support for the new ISO C++ standard, C++11 A new port has been added to support AArch64 Updates for ARM, x86, MIPS, PPC/PPC64, SH, SPARC, TILE* [*1] we should support this too! [*2] we should look into this. https://code.google.com/p/address-sanitizer/ @ text @d2 2 a3 1 Chapter 3. Using
Chapter 3. Using
Prev Part I.  d6 1 a6 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

d9 1 a9 1 several GCC d14 2 a15 2

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98Use the 1998 ISO C++ standard plus amendments.
-std=gnu++98As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthread or -pthreadsFor ISO C++11 <thread>, <future>, <mutex>, or <condition_variable>.
-fopenmpFor parallel mode.

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Make Home Headers
@ 1.1.1.3 log @import GCC 5.3.0. see these urls for details which are too large to include here: http://gcc.gnu.org/gcc-4.9/changes.html http://gcc.gnu.org/gcc-5/changes.html (note that GCC 5.x is a release stream like GCC 4.9.x, 4.8.x, etc.) the main issues we will have are: The default mode for C is now -std=gnu11 instead of -std=gnu89. ARM: The deprecated option -mwords-little-endian has been removed. The options -mapcs, -mapcs-frame, -mtpcs-frame and -mtpcs-leaf-frame which are only applicable to the old ABI have been deprecated. MIPS: The o32 ABI has been modified and extended. The o32 64-bit floating-point register support is now obsolete and has been removed. It has been replaced by three ABI extensions FPXX, FP64A, and FP64. The meaning of the -mfp64 command-line option has changed. It is now used to enable the FP64A and FP64 ABI extensions. @ text @d5 3 a7 2  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

The set of features available in the GNU C++ library is shaped by d13 2 a14 9

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98Use the 1998 ISO C++ standard plus amendments.
-std=gnu++98As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthread or -pthreadsFor ISO C++11 <thread>, <future>, <mutex>, or <condition_variable>.
-latomicLinking to libatomic is required for some uses of ISO C++11 <atomic>.
-fopenmpFor parallel mode.

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Make Home Headers
@ 1.1.1.4 log @import GCC 5.4.0 release. there's not a lot of new info though at least these 135 (!) GCC PRs have been fixed by the update: 68730 69714 67550 70209 71254 70839 69737 70067 67355 67172 69239 65779 69546 70272 70421 65985 67339 67411 68309 68585 68679 68890 68949 69009 70139 70494 68162 69135 70306 68965 70297 70635 66786 69098 70347 69719 70526 70941 69400 69577 69447 65689 65886 65932 66655 68269 68789 69614 69648 69666 69764 69794 70044 70052 65726 68910 64289 68671 68835 69669 70329 71204 69355 67364 68049 68998 69323 69743 69995 69146 68651 67755 67484 68790 68907 69099 69496 69509 69516 70393 69222 69703 69939 70609 71004 71005 71036 71037 71038 68636 69013 69606 70115 70333 70430 60290 70356 69305 70024 67781 69414 69140 70510 60164 66635 67896 68106 68298 68449 68779 68921 68986 69037 69147 69194 69366 69399 69705 69917 69969 70613 71317 69268 70269 69032 65702 69219 69484 65996 66680 68283 69603 70350 67451 61397 @ text @d5 1 a5 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

d11 2 a12 7 The standard library conforms to the dialect of C++ specified by the -std option passed to the compiler. By default, g++ is equivalent to g++ -std=gnu++98 for GCC 5 and older releases.

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98 or -std=c++03 Use the 1998 ISO C++ standard plus amendments.
-std=gnu++98 or -std=gnu++03 As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-std=c++14Use the 2014 ISO C++ standard.
-std=gnu++14As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthread or -pthreadsFor ISO C++11 a19 3
-lstdc++fsLinking to libstdc++fs is required for use of the Filesystem library extensions in <experimental/filesystem>. @ 1.1.1.5 log @import GCC 6.4.0. see this url for details which are too large to include here: http://gcc.gnu.org/gcc-6/changes.html the main visible changes appear to be: - The default mode for C++ is now -std=gnu++14 instead of -std=gnu++98. - The C and C++ compilers now support attributes on enumerators. - Diagnostics can now contain "fix-it hints" - more warnings (some added to -Wall) @ text @d14 1 a14 2 g++ -std=gnu++14 since GCC 6, and g++ -std=gnu++98 for older releases. @ 1.1.1.5.4.1 log @Sync with HEAD @ text @d2 1 a2 1 Chapter 3. Using
Chapter 3. Using
Prev Part I.  d16 1 a16 1

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98 or -std=c++03 d18 1 a18 1 As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-std=c++14Use the 2014 ISO C++ standard.
-std=gnu++14As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthreadFor ISO C++11 @ 1.1.1.5.4.2 log @Merge changes from current as of 20200406 @ text @d5 1 a5 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Non-memory leaks in Pool and MT allocators
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

@ 1.1.1.5.4.3 log @Mostly merge changes from HEAD upto 20200411 @ text @d28 1 a28 3 <experimental/filesystem> and the C++17 Filesystem library in <filesystem>. @ 1.1.1.5.2.1 log @Sync with HEAD, resolve a couple of conflicts @ text @d2 1 a2 1 Chapter 3. Using

Chapter 3. Using
Prev Part I.  d16 1 a16 1

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98 or -std=c++03 @ 1.1.1.5.2.2 log @Sync with HEAD @ text @d18 1 a18 1 As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-std=c++14Use the 2014 ISO C++ standard.
-std=gnu++14As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthreadFor ISO C++11 @ 1.1.1.6 log @import GCC 6.5.0. this is largely a maint release with no particularly features listed here: http://gcc.gnu.org/gcc-6/changes.html this fixes over 250 PRs in the GCC bugzilla: https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=6.5 @ text @d2 1 a2 1 Chapter 3. Using
Chapter 3. Using
Prev Part I.  d16 1 a16 1

Table 3.1. C++ Command Options

Option FlagsDescription
-std=c++98 or -std=c++03 @ 1.1.1.7 log @import GCC 7.4.0. main changes include: The non-standard C++0x type traits has_trivial_default_constructor, has_trivial_copy_constructor and has_trivial_copy_assign have been removed. On ARM targets (arm*-*-*), a bug introduced in GCC 5 that affects conformance to the procedure call standard (AAPCS) has been fixed. Many optimiser improvements DWARF-5 support. Many new and enhanced warnings. Warnings about format strings now underline the pertinent part of the string, and can offer suggested fixes. Several new warnings related to buffer overflows and buffer truncation. New __builtin_add_overflow_p, __builtin_sub_overflow_p, __builtin_mul_overflow_p built-ins added that test for overflow. The C++ front end has experimental support for all of the current C++17 draft. The -fverbose-asm option has been expanded to prints comments showing the source lines that correspond to the assembly. The gcc and g++ driver programs will now provide suggestions for misspelled arguments to command-line options. AArch64 specific: GCC has been updated to the latest revision of the procedure call standard (AAPCS64) to provide support for parameter passing when data types have been over-aligned. The ARMv8.2-A and ARMv8.3-A architecture are now supported. ARM specific: Support for the ARMv5 and ARMv5E architectures has been deprecated (which have no known implementations). A new command-line option -mpure-code has been added. It does not allow constant data to be placed in code sections. x86 specific: Support for the AVX-512 4FMAPS, 4VNNIW, VPOPCNTDQ and Software Guard Extensions (SGX) ISA extensions has been added. PPC specific: GCC now diagnoses inline assembly that clobbers register r2. RISC-V specific: Support for the RISC-V instruction set has been added. SH specific: Support for SH5/SH64 has been removed. Support for SH2A has been enhanced. @ text @d18 1 a18 1 As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-std=c++14Use the 2014 ISO C++ standard.
-std=gnu++14As directly above, with GNU extensions.
-fexceptionsSee exception-free dialect
-frttiAs above, but RTTI-free dialect.
-pthreadFor ISO C++11 @ 1.1.1.8 log @import GCC 8.3. it includes these new features: - many optimisations improved: inter-procedural, profile-directed, LTO, loops including user-controllable unroll support, and more. - columns numbers added to line numbers in dwarf - gcov extended significantly - many sanitizer updates - many new warning messages - many better hints and more useful error messages - minor ABI changes on x86-64 libstdc++, and some c++17 modes - draft c++2a features - better c++17 experimental support - Armv8.4-A supported, better 8.2-A and 8.3-A support, including 32 bit arm port. cortex a-55, a-75 and a-55.a-75 combo support. - in the GCC bugzilla, 8.1 shows 1149 bugs fixed, 8.2 shows 100, and 8.3 shows 158. @ text @d28 1 a28 3 <experimental/filesystem> and the C++17 Filesystem library in <filesystem>. @ 1.1.1.9 log @import GCC 8.4. it fixes at least these 210 PRs in GCC bugzilla: 90095 93348 89906 89766 86747 87770 89588 89753 88235 89762 89684 89946 89965 90010 90026 90733 90810 90840 90842 90867 91623 92930 93073 93402 93505 93576 93744 93820 93908 85762 86429 86521 87327 87480 87513 87554 87685 87748 88183 88380 88394 88419 88690 88820 89381 89422 89576 89831 89917 90951 92003 92852 93140 80791 89358 89970 90899 89212 89419 92745 93684 93789 88273 91826 92376 84746 89497 89595 89664 89711 89725 90018 90316 90900 91108 91293 91772 92763 93054 93246 90313 92420 93434 93767 88530 89517 91838 79262 84680 85459 85711 85860 86567 87008 87651 87652 88469 89546 89827 90197 93072 93241 81800 89190 85400 91472 91854 92095 92131 92575 93704 60228 61414 65782 89405 89498 89703 89752 90187 90193 90898 91401 91450 91665 92296 92384 92438 92615 92648 92723 92732 92904 93087 93228 93515 93905 82081 92859 89712 89876 92106 82645 78552 81266 85965 89102 90165 90299 90532 91436 92059 93205 93325 93562 90359 91280 91375 92674 92704 93439 92768 80938 83361 90563 92113 92961 87833 89848 89902 89903 92022 93828 78179 79221 82920 84016 87015 88075 89077 89266 90454 90634 91226 92154 92664 92886 93065 92692 92629 80590 91944 92899 92977 93463 89601 88025 91660 91845 90498 91077 84487 86119 89174 89981 91550 92569 84135 84974 90872 93714 @ text @d5 1 a5 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Non-memory leaks in Pool and MT allocators
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

@ 1.1.1.10 log @import GCC 7.5.0. doing this here so that the vendor branch has the code we'll merge into gcc.old and the netbsd-9 tree gcc tree. GCC 8.4.0 will be imported immediately on top of this again, restoring the current status. these PRs in the GCC bugzilla are fixed with this update: 89869 80693 89795 84272 85593 86669 87148 87647 87895 88103 88107 88563 88870 88976 89002 89187 89195 89234 89303 89314 89354 89361 89403 89412 89512 89520 89590 89621 89663 89679 89704 89734 89872 89933 90090 90208 87075 85870 89009 89242 88167 80864 81933 85890 86608 87145 88857 89024 89119 89214 89511 89612 89705 89400 81740 82186 84552 86554 87609 88105 88149 88415 88739 88903 89135 89223 89296 89505 89572 89677 89698 89710 90006 90020 90071 90328 90474 91126 91162 91812 91887 90075 88998 89945 87047 87506 88074 88656 88740 91137 89008 84010 89349 91136 91347 91995 89397 87030 60702 78884 85594 87649 87725 88181 88470 88553 88568 88588 88620 88644 88906 88949 89246 89587 89726 89768 89796 89998 90108 90756 90950 91704 88825 88983 86538 51333 89446 90220 91308 92143 89392 90213 90278 91131 91200 91510 89037 91481 87673 88418 88938 88948 90547 27221 58321 61250 67183 67958 77583 83531 86215 88648 88720 88726 89091 89466 89629 90105 90329 90585 90760 90924 91087 89222 81956 71861 35031 69455 81849 82993 85798 88138 88155 88169 88205 88206 88228 88249 88269 88376 77703 80260 82077 86248 88393 90786 57048 66089 66695 67679 68009 71723 72714 84394 85544 87734 88298 90937 91557 63891 64132 65342 68649 68717 71066 71860 71935 77746 78421 78645 78865 78983 79485 79540 85953 88326 89651 90744 @ text @d5 1 a5 1

 Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

d28 3 a30 1 <experimental/filesystem>. @ 1.1.1.11 log @re-import GCC 8.4.0. @ text @d5 1 a5 1

 Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Non-memory leaks in Pool and MT allocators
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking
Profile-based Performance Analysis

Command Options

d28 1 a28 3 <experimental/filesystem> and the C++17 Filesystem library in <filesystem>. @ 1.1.1.12 log @initial import of GCC 9.3.0. changes include: - live patching support - shell completion help - generally better diagnostic output (less verbose/more useful) - diagnostics and optimisation choices can be emitted in json - asan memory usage reduction - many general, and specific to switch, inter-procedure, profile and link-time optimisations. from the release notes: "Overall compile time of Firefox 66 and LibreOffice 6.2.3 on an 8-core machine was reduced by about 5% compared to GCC 8.3" - OpenMP 5.0 support - better spell-guesser - partial experimental support for c2x and c++2a - c++17 is no longer experimental - arm AAPCS GCC 6-8 structure passing bug fixed, may cause incompatibility (restored compat with GCC 5 and earlier.) - openrisc support @ text @d28 4 a31 5 <experimental/filesystem>.

-fopenmpFor parallel mode.
-ltbbLinking to tbb (Thread Building Blocks) is required for use of the Parallel Standard Algorithms and execution policies in <execution>.

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@ 1.1.1.13 log @initial import of GCC 10.3.0. main changes include: caveats: - ABI issue between c++14 and c++17 fixed - profile mode is removed from libstdc++ - -fno-common is now the default new features: - new flags -fallocation-dce, -fprofile-partial-training, -fprofile-reproducible, -fprofile-prefix-path, and -fanalyzer - many new compile and link time optimisations - enhanced drive optimisations - openacc 2.6 support - openmp 5.0 features - new warnings: -Wstring-compare and -Wzero-length-bounds - extended warnings: -Warray-bounds, -Wformat-overflow, -Wrestrict, -Wreturn-local-addr, -Wstringop-overflow, -Warith-conversion, -Wmismatched-tags, and -Wredundant-tags - some likely C2X features implemented - more C++20 implemented - many new arm & intel CPUs known hundreds of reported bugs are fixed. full list of changes can be found at: https://gcc.gnu.org/gcc-10/changes.html @ text @d5 1 a5 1 		 Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Versions of Library Binary Files
Memory Leak Hunting
Non-memory leaks in Pool and MT allocators
Data Race Hunting
Using gdb
Tracking uncaught exceptions
Debug Mode
Compile Time Checking

Command Options

@ 1.1.1.14 log @initial import of GCC 12.3.0. major changes in GCC 11 included: - The default mode for C++ is now -std=gnu++17 instead of -std=gnu++14. - When building GCC itself, the host compiler must now support C++11, rather than C++98. - Some short options of the gcov tool have been renamed: -i to -j and -j to -H. - ThreadSanitizer improvements. - Introduce Hardware-assisted AddressSanitizer support. - For targets that produce DWARF debugging information GCC now defaults to DWARF version 5. This can produce up to 25% more compact debug information compared to earlier versions. - Many optimisations. - The existing malloc attribute has been extended so that it can be used to identify allocator/deallocator API pairs. A pair of new -Wmismatched-dealloc and -Wmismatched-new-delete warnings are added. - Other new warnings: -Wsizeof-array-div, enabled by -Wall, warns about divisions of two sizeof operators when the first one is applied to an array and the divisor does not equal the size of the array element. -Wstringop-overread, enabled by default, warns about calls to string functions reading past the end of the arrays passed to them as arguments. -Wtsan, enabled by default, warns about unsupported features in ThreadSanitizer (currently std::atomic_thread_fence). - Enchanced warnings: -Wfree-nonheap-object detects many more instances of calls to deallocation functions with pointers not returned from a dynamic memory allocation function. -Wmaybe-uninitialized diagnoses passing pointers or references to uninitialized memory to functions taking const-qualified arguments. -Wuninitialized detects reads from uninitialized dynamically allocated memory. -Warray-parameter warns about functions with inconsistent array forms. -Wvla-parameter warns about functions with inconsistent VLA forms. - Several new features from the upcoming C2X revision of the ISO C standard are supported with -std=c2x and -std=gnu2x. - Several C++20 features have been implemented. - The C++ front end has experimental support for some of the upcoming C++23 draft. - Several new C++ warnings. - Enhanced Arm, AArch64, x86, and RISC-V CPU support. - The implementation of how program state is tracked within -fanalyzer has been completely rewritten with many enhancements. see https://gcc.gnu.org/gcc-11/changes.html for a full list. major changes in GCC 12 include: - An ABI incompatibility between C and C++ when passing or returning by value certain aggregates containing zero width bit-fields has been discovered on various targets. x86-64, ARM and AArch64 will always ignore them (so there is a C ABI incompatibility between GCC 11 and earlier with GCC 12 or later), PowerPC64 ELFv2 always take them into account (so there is a C++ ABI incompatibility, GCC 4.4 and earlier compatible with GCC 12 or later, incompatible with GCC 4.5 through GCC 11). RISC-V has changed the handling of these already starting with GCC 10. As the ABI requires, MIPS takes them into account handling function return values so there is a C++ ABI incompatibility with GCC 4.5 through 11. - STABS: Support for emitting the STABS debugging format is deprecated and will be removed in the next release. All ports now default to emit DWARF (version 2 or later) debugging info or are obsoleted. - Vectorization is enabled at -O2 which is now equivalent to the original -O2 -ftree-vectorize -fvect-cost-model=very-cheap. - GCC now supports the ShadowCallStack sanitizer. - Support for __builtin_shufflevector compatible with the clang language extension was added. - Support for attribute unavailable was added. - Support for __builtin_dynamic_object_size compatible with the clang language extension was added. - New warnings: -Wbidi-chars warns about potentially misleading UTF-8 bidirectional control characters. -Warray-compare warns about comparisons between two operands of array type. - Some new features from the upcoming C2X revision of the ISO C standard are supported with -std=c2x and -std=gnu2x. - Several C++23 features have been implemented. - Many C++ enhancements across warnings and -f options. see https://gcc.gnu.org/gcc-12/changes.html for a full list. @ text @d14 1 a14 2 g++ -std=gnu++17 since GCC 11, and g++ -std=gnu++14 in GCC 6, 7, 8, 9, and 10, and d18 1 a18 5

As directly above, with GNU extensions.
-std=c++11Use the 2011 ISO C++ standard.
-std=gnu++11As directly above, with GNU extensions.
-std=c++14Use the 2014 ISO C++ standard.
-std=gnu++14As directly above, with GNU extensions.
-fno-exceptions See exception-free dialect
-fno-rtti As above, but RTTI-free dialect.
-pthreadFor ISO C++11 a28 6
-lstdc++_libbacktraceUntil C++23 support is non-experimental, linking to libstdc++_libbacktrace.a is required for use of the C++23 type std::stacktrace and related types in <stacktrace>. @ 1.1.1.14.2.1 log @Sync with HEAD. @ text @d7 1 a7 1 several GCC d17 3 a19 5

Table 3.1. C++ Command Options

Option FlagsDescription
-std Select the C++ standard, and whether to use the base standard or GNU dialect.
@ 1.1.1.15 log @import GCC 12.4.0. this includes at least 85 GCC PRs fixed, 2 C, 17 C++, 16 libstdc++-v3, at least 13 target-specific (x86, arm64, riscv mostly), and at least 24 optimisation PRs. @ text @d7 1 a7 1 several GCC d17 3 a19 5

Table 3.1. C++ Command Options

Option FlagsDescription
-std Select the C++ standard, and whether to use the base standard or GNU dialect.
@ 1.1.1.16 log @initial import of GCC 14.3.0. major changes in GCC 13: - improved sanitizer - zstd debug info compression - LTO improvements - SARIF based diagnostic support - new warnings: -Wxor-used-as-pow, -Wenum-int-mismatch, -Wself-move, -Wdangling-reference - many new -Wanalyzer* specific warnings - enhanced warnings: -Wpessimizing-move, -Wredundant-move - new attributes to mark file descriptors, c++23 "assume" - several C23 features added - several C++23 features added - many new features for Arm, x86, RISC-V major changes in GCC 14: - more strict C99 or newer support - ia64* marked deprecated (but seemingly still in GCC 15.) - several new hardening features - support for "hardbool", which can have user supplied values of true/false - explicit support for stack scrubbing upon function exit - better auto-vectorisation support - added clang-compatible __has_feature and __has_extension - more C23, including -std=c23 - several C++26 features added - better diagnostics in C++ templates - new warnings: -Wnrvo, Welaborated-enum-base - many new features for Arm, x86, RISC-V - possible ABI breaking change for SPARC64 and small structures with arrays of floats. @ text @d5 1 a5 1  Next

Chapter 3. Using

Table of Contents

Command Options
Headers
Header Files
Mixing Headers
The C Headers and namespace std
Precompiled Headers
Macros
Dual ABI
Troubleshooting
Namespaces
Available Namespaces
namespace std
Using Namespace Composition
Linking
Almost Nothing
Finding Dynamic or Shared Libraries
Experimental Library Extensions
Concurrency
Prerequisites
Thread Safety
Atomics
IO
Structure
Defaults
Future
Alternatives
Containers
Exceptions
Exception Safety
Exception Neutrality
Memory allocation
Doing without
Compatibility
With C
With POSIX thread cancellation
Debugging Support
Using g++
Debug Mode
Tracking uncaught exceptions
Memory Leak Hunting
Non-memory leaks in Pool and MT allocators
Data Race Hunting
Using gdb
Debug Versions of Library Binary Files
Compile Time Checking

Command Options

d7 1 a7 1 several GCC d33 9 a41 14

-lstdc++expLinking to libstdc++exp.a is required for use of experimental C++ library features. This currently provides support for the C++23 types defined in the <stacktrace> header, the Filesystem library extensions defined in the <experimental/filesystem> header, and the Contracts extensions enabled by -fcontracts.
-lstdc++fsLinking to libstdc++fs.a is another way to use the Filesystem library extensions defined in the <experimental/filesystem> header. The libstdc++exp.a library also provides all the symbols contained in this library. a44 6
-ffreestanding Limits the library to its freestanding subset. Headers that are not supported in freestanding will emit a "This header is not available in freestanding mode" error. Headers that are in the freestanding subset partially will not expose functionality that is not part of the freestanding subset. @