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locks; strict; comment @// @; 1.1 date 2013.11.28.14.14.53; author joerg; state Exp; branches 1.1.1.1; next ; commitid ow8OybrawrB1f3fx; 1.1.1.1 date 2013.11.28.14.14.53; author joerg; state Exp; branches; next 1.1.1.2; commitid ow8OybrawrB1f3fx; 1.1.1.2 date 2014.01.05.15.38.05; author joerg; state Exp; branches; next 1.1.1.3; commitid wh3aCSIWykURqWjx; 1.1.1.3 date 2014.01.15.21.26.25; author joerg; state Exp; branches; next 1.1.1.4; commitid NQXlzzA0SPkc5glx; 1.1.1.4 date 2014.02.14.20.07.09; author joerg; state Exp; branches; next 1.1.1.5; commitid annVkZ1sc17rF6px; 1.1.1.5 date 2014.03.04.19.53.46; author joerg; state Exp; branches 1.1.1.5.2.1 1.1.1.5.4.1; next 1.1.1.6; commitid 29z1hJonZISIXprx; 1.1.1.6 date 2014.05.30.18.14.40; author joerg; state Exp; branches; next 1.1.1.7; commitid 8q0kdlBlCn09GACx; 1.1.1.7 date 2014.08.10.17.08.36; author joerg; state Exp; branches 1.1.1.7.4.1; next 1.1.1.8; commitid N85tXAN6Ex9VZPLx; 1.1.1.8 date 2016.02.27.22.12.10; author joerg; state Exp; 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author tls; state dead; branches; next 1.1.1.7.4.2; commitid jTnpym9Qu0o4R1Nx; 1.1.1.7.4.2 date 2014.08.19.23.47.27; author tls; state Exp; branches; next ; commitid jTnpym9Qu0o4R1Nx; 1.1.1.8.2.1 date 2017.03.20.06.52.37; author pgoyette; state Exp; branches; next ; commitid jjw7cAwgyKq7RfKz; 1.1.1.11.2.1 date 2018.07.28.04.33.17; author pgoyette; state Exp; branches; next ; commitid 1UP1xAIUxv1ZgRLA; 1.1.1.11.4.1 date 2019.06.10.21.45.21; author christos; state Exp; branches; next 1.1.1.11.4.2; commitid jtc8rnCzWiEEHGqB; 1.1.1.11.4.2 date 2020.04.13.07.46.32; author martin; state dead; branches; next ; commitid X01YhRUPVUDaec4C; desc @@ 1.1 log @Initial revision @ text @//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This contains code to emit Aggregate Expr nodes as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CGObjCRuntime.h" #include "CodeGenModule.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/StmtVisitor.h" #include "llvm/IR/Constants.h" #include "llvm/IR/Function.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Intrinsics.h" using namespace clang; using namespace CodeGen; //===----------------------------------------------------------------------===// // Aggregate Expression Emitter //===----------------------------------------------------------------------===// namespace { class AggExprEmitter : public StmtVisitor { CodeGenFunction &CGF; CGBuilderTy &Builder; AggValueSlot Dest; /// We want to use 'dest' as the return slot except under two /// conditions: /// - The destination slot requires garbage collection, so we /// need to use the GC API. /// - The destination slot is potentially aliased. bool shouldUseDestForReturnSlot() const { return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased()); } ReturnValueSlot getReturnValueSlot() const { if (!shouldUseDestForReturnSlot()) return ReturnValueSlot(); return ReturnValueSlot(Dest.getAddr(), Dest.isVolatile()); } AggValueSlot EnsureSlot(QualType T) { if (!Dest.isIgnored()) return Dest; return CGF.CreateAggTemp(T, "agg.tmp.ensured"); } void EnsureDest(QualType T) { if (!Dest.isIgnored()) return; Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured"); } public: AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest) : CGF(cgf), Builder(CGF.Builder), Dest(Dest) { } //===--------------------------------------------------------------------===// // Utilities //===--------------------------------------------------------------------===// /// EmitAggLoadOfLValue - Given an expression with aggregate type that /// represents a value lvalue, this method emits the address of the lvalue, /// then loads the result into DestPtr. void EmitAggLoadOfLValue(const Expr *E); /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void EmitFinalDestCopy(QualType type, const LValue &src); void EmitFinalDestCopy(QualType type, RValue src, CharUnits srcAlignment = CharUnits::Zero()); void EmitCopy(QualType type, const AggValueSlot &dest, const AggValueSlot &src); void EmitMoveFromReturnSlot(const Expr *E, RValue Src); void EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType, QualType elementType, InitListExpr *E); AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) { if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T)) return AggValueSlot::NeedsGCBarriers; return AggValueSlot::DoesNotNeedGCBarriers; } bool TypeRequiresGCollection(QualType T); //===--------------------------------------------------------------------===// // Visitor Methods //===--------------------------------------------------------------------===// void VisitStmt(Stmt *S) { CGF.ErrorUnsupported(S, "aggregate expression"); } void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); } void VisitGenericSelectionExpr(GenericSelectionExpr *GE) { Visit(GE->getResultExpr()); } void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); } void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { return Visit(E->getReplacement()); } // l-values. void VisitDeclRefExpr(DeclRefExpr *E) { // For aggregates, we should always be able to emit the variable // as an l-value unless it's a reference. This is due to the fact // that we can't actually ever see a normal l2r conversion on an // aggregate in C++, and in C there's no language standard // actively preventing us from listing variables in the captures // list of a block. if (E->getDecl()->getType()->isReferenceType()) { if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { EmitFinalDestCopy(E->getType(), result.getReferenceLValue(CGF, E)); return; } } EmitAggLoadOfLValue(E); } void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); } void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); } void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); } void VisitCompoundLiteralExpr(CompoundLiteralExpr *E); void VisitArraySubscriptExpr(ArraySubscriptExpr *E) { EmitAggLoadOfLValue(E); } void VisitPredefinedExpr(const PredefinedExpr *E) { EmitAggLoadOfLValue(E); } // Operators. void VisitCastExpr(CastExpr *E); void VisitCallExpr(const CallExpr *E); void VisitStmtExpr(const StmtExpr *E); void VisitBinaryOperator(const BinaryOperator *BO); void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO); void VisitBinAssign(const BinaryOperator *E); void VisitBinComma(const BinaryOperator *E); void VisitObjCMessageExpr(ObjCMessageExpr *E); void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { EmitAggLoadOfLValue(E); } void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO); void VisitChooseExpr(const ChooseExpr *CE); void VisitInitListExpr(InitListExpr *E); void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E); void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { Visit(DAE->getExpr()); } void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { CodeGenFunction::CXXDefaultInitExprScope Scope(CGF); Visit(DIE->getExpr()); } void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E); void VisitCXXConstructExpr(const CXXConstructExpr *E); void VisitLambdaExpr(LambdaExpr *E); void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E); void VisitExprWithCleanups(ExprWithCleanups *E); void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E); void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); } void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E); void VisitOpaqueValueExpr(OpaqueValueExpr *E); void VisitPseudoObjectExpr(PseudoObjectExpr *E) { if (E->isGLValue()) { LValue LV = CGF.EmitPseudoObjectLValue(E); return EmitFinalDestCopy(E->getType(), LV); } CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType())); } void VisitVAArgExpr(VAArgExpr *E); void EmitInitializationToLValue(Expr *E, LValue Address); void EmitNullInitializationToLValue(LValue Address); // case Expr::ChooseExprClass: void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); } void VisitAtomicExpr(AtomicExpr *E) { CGF.EmitAtomicExpr(E, EnsureSlot(E->getType()).getAddr()); } }; } // end anonymous namespace. //===----------------------------------------------------------------------===// // Utilities //===----------------------------------------------------------------------===// /// EmitAggLoadOfLValue - Given an expression with aggregate type that /// represents a value lvalue, this method emits the address of the lvalue, /// then loads the result into DestPtr. void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) { LValue LV = CGF.EmitLValue(E); // If the type of the l-value is atomic, then do an atomic load. if (LV.getType()->isAtomicType()) { CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest); return; } EmitFinalDestCopy(E->getType(), LV); } /// \brief True if the given aggregate type requires special GC API calls. bool AggExprEmitter::TypeRequiresGCollection(QualType T) { // Only record types have members that might require garbage collection. const RecordType *RecordTy = T->getAs(); if (!RecordTy) return false; // Don't mess with non-trivial C++ types. RecordDecl *Record = RecordTy->getDecl(); if (isa(Record) && (cast(Record)->hasNonTrivialCopyConstructor() || !cast(Record)->hasTrivialDestructor())) return false; // Check whether the type has an object member. return Record->hasObjectMember(); } /// \brief Perform the final move to DestPtr if for some reason /// getReturnValueSlot() didn't use it directly. /// /// The idea is that you do something like this: /// RValue Result = EmitSomething(..., getReturnValueSlot()); /// EmitMoveFromReturnSlot(E, Result); /// /// If nothing interferes, this will cause the result to be emitted /// directly into the return value slot. Otherwise, a final move /// will be performed. void AggExprEmitter::EmitMoveFromReturnSlot(const Expr *E, RValue src) { if (shouldUseDestForReturnSlot()) { // Logically, Dest.getAddr() should equal Src.getAggregateAddr(). // The possibility of undef rvalues complicates that a lot, // though, so we can't really assert. return; } // Otherwise, copy from there to the destination. assert(Dest.getAddr() != src.getAggregateAddr()); std::pair typeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); EmitFinalDestCopy(E->getType(), src, typeInfo.second); } /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src, CharUnits srcAlign) { assert(src.isAggregate() && "value must be aggregate value!"); LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddr(), type, srcAlign); EmitFinalDestCopy(type, srcLV); } /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src) { // If Dest is ignored, then we're evaluating an aggregate expression // in a context that doesn't care about the result. Note that loads // from volatile l-values force the existence of a non-ignored // destination. if (Dest.isIgnored()) return; AggValueSlot srcAgg = AggValueSlot::forLValue(src, AggValueSlot::IsDestructed, needsGC(type), AggValueSlot::IsAliased); EmitCopy(type, Dest, srcAgg); } /// Perform a copy from the source into the destination. /// /// \param type - the type of the aggregate being copied; qualifiers are /// ignored void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest, const AggValueSlot &src) { if (dest.requiresGCollection()) { CharUnits sz = CGF.getContext().getTypeSizeInChars(type); llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity()); CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, dest.getAddr(), src.getAddr(), size); return; } // If the result of the assignment is used, copy the LHS there also. // It's volatile if either side is. Use the minimum alignment of // the two sides. CGF.EmitAggregateCopy(dest.getAddr(), src.getAddr(), type, dest.isVolatile() || src.isVolatile(), std::min(dest.getAlignment(), src.getAlignment())); } /// \brief Emit the initializer for a std::initializer_list initialized with a /// real initializer list. void AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) { // Emit an array containing the elements. The array is externally destructed // if the std::initializer_list object is. ASTContext &Ctx = CGF.getContext(); LValue Array = CGF.EmitLValue(E->getSubExpr()); assert(Array.isSimple() && "initializer_list array not a simple lvalue"); llvm::Value *ArrayPtr = Array.getAddress(); const ConstantArrayType *ArrayType = Ctx.getAsConstantArrayType(E->getSubExpr()->getType()); assert(ArrayType && "std::initializer_list constructed from non-array"); // FIXME: Perform the checks on the field types in SemaInit. RecordDecl *Record = E->getType()->castAs()->getDecl(); RecordDecl::field_iterator Field = Record->field_begin(); if (Field == Record->field_end()) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } // Start pointer. if (!Field->getType()->isPointerType() || !Ctx.hasSameType(Field->getType()->getPointeeType(), ArrayType->getElementType())) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(), Dest.getAlignment()); LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field); llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0); llvm::Value *IdxStart[] = { Zero, Zero }; llvm::Value *ArrayStart = Builder.CreateInBoundsGEP(ArrayPtr, IdxStart, "arraystart"); CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start); ++Field; if (Field == Record->field_end()) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } llvm::Value *Size = Builder.getInt(ArrayType->getSize()); LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field); if (Field->getType()->isPointerType() && Ctx.hasSameType(Field->getType()->getPointeeType(), ArrayType->getElementType())) { // End pointer. llvm::Value *IdxEnd[] = { Zero, Size }; llvm::Value *ArrayEnd = Builder.CreateInBoundsGEP(ArrayPtr, IdxEnd, "arrayend"); CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength); } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) { // Length. CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength); } else { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } } /// \brief Emit initialization of an array from an initializer list. void AggExprEmitter::EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType, QualType elementType, InitListExpr *E) { uint64_t NumInitElements = E->getNumInits(); uint64_t NumArrayElements = AType->getNumElements(); assert(NumInitElements <= NumArrayElements); // DestPtr is an array*. Construct an elementType* by drilling // down a level. llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); llvm::Value *indices[] = { zero, zero }; llvm::Value *begin = Builder.CreateInBoundsGEP(DestPtr, indices, "arrayinit.begin"); // Exception safety requires us to destroy all the // already-constructed members if an initializer throws. // For that, we'll need an EH cleanup. QualType::DestructionKind dtorKind = elementType.isDestructedType(); llvm::AllocaInst *endOfInit = 0; EHScopeStack::stable_iterator cleanup; llvm::Instruction *cleanupDominator = 0; if (CGF.needsEHCleanup(dtorKind)) { // In principle we could tell the cleanup where we are more // directly, but the control flow can get so varied here that it // would actually be quite complex. Therefore we go through an // alloca. endOfInit = CGF.CreateTempAlloca(begin->getType(), "arrayinit.endOfInit"); cleanupDominator = Builder.CreateStore(begin, endOfInit); CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType, CGF.getDestroyer(dtorKind)); cleanup = CGF.EHStack.stable_begin(); // Otherwise, remember that we didn't need a cleanup. } else { dtorKind = QualType::DK_none; } llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1); // The 'current element to initialize'. The invariants on this // variable are complicated. Essentially, after each iteration of // the loop, it points to the last initialized element, except // that it points to the beginning of the array before any // elements have been initialized. llvm::Value *element = begin; // Emit the explicit initializers. for (uint64_t i = 0; i != NumInitElements; ++i) { // Advance to the next element. if (i > 0) { element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element"); // Tell the cleanup that it needs to destroy up to this // element. TODO: some of these stores can be trivially // observed to be unnecessary. if (endOfInit) Builder.CreateStore(element, endOfInit); } LValue elementLV = CGF.MakeAddrLValue(element, elementType); EmitInitializationToLValue(E->getInit(i), elementLV); } // Check whether there's a non-trivial array-fill expression. // Note that this will be a CXXConstructExpr even if the element // type is an array (or array of array, etc.) of class type. Expr *filler = E->getArrayFiller(); bool hasTrivialFiller = true; if (CXXConstructExpr *cons = dyn_cast_or_null(filler)) { assert(cons->getConstructor()->isDefaultConstructor()); hasTrivialFiller = cons->getConstructor()->isTrivial(); } // Any remaining elements need to be zero-initialized, possibly // using the filler expression. We can skip this if the we're // emitting to zeroed memory. if (NumInitElements != NumArrayElements && !(Dest.isZeroed() && hasTrivialFiller && CGF.getTypes().isZeroInitializable(elementType))) { // Use an actual loop. This is basically // do { *array++ = filler; } while (array != end); // Advance to the start of the rest of the array. if (NumInitElements) { element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start"); if (endOfInit) Builder.CreateStore(element, endOfInit); } // Compute the end of the array. llvm::Value *end = Builder.CreateInBoundsGEP(begin, llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements), "arrayinit.end"); llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body"); // Jump into the body. CGF.EmitBlock(bodyBB); llvm::PHINode *currentElement = Builder.CreatePHI(element->getType(), 2, "arrayinit.cur"); currentElement->addIncoming(element, entryBB); // Emit the actual filler expression. LValue elementLV = CGF.MakeAddrLValue(currentElement, elementType); if (filler) EmitInitializationToLValue(filler, elementLV); else EmitNullInitializationToLValue(elementLV); // Move on to the next element. llvm::Value *nextElement = Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next"); // Tell the EH cleanup that we finished with the last element. if (endOfInit) Builder.CreateStore(nextElement, endOfInit); // Leave the loop if we're done. llvm::Value *done = Builder.CreateICmpEQ(nextElement, end, "arrayinit.done"); llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end"); Builder.CreateCondBr(done, endBB, bodyBB); currentElement->addIncoming(nextElement, Builder.GetInsertBlock()); CGF.EmitBlock(endBB); } // Leave the partial-array cleanup if we entered one. if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator); } //===----------------------------------------------------------------------===// // Visitor Methods //===----------------------------------------------------------------------===// void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){ Visit(E->GetTemporaryExpr()); } void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) { EmitFinalDestCopy(e->getType(), CGF.getOpaqueLValueMapping(e)); } void AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { if (Dest.isPotentiallyAliased() && E->getType().isPODType(CGF.getContext())) { // For a POD type, just emit a load of the lvalue + a copy, because our // compound literal might alias the destination. EmitAggLoadOfLValue(E); return; } AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitAggExpr(E->getInitializer(), Slot); } /// Attempt to look through various unimportant expressions to find a /// cast of the given kind. static Expr *findPeephole(Expr *op, CastKind kind) { while (true) { op = op->IgnoreParens(); if (CastExpr *castE = dyn_cast(op)) { if (castE->getCastKind() == kind) return castE->getSubExpr(); if (castE->getCastKind() == CK_NoOp) continue; } return 0; } } void AggExprEmitter::VisitCastExpr(CastExpr *E) { switch (E->getCastKind()) { case CK_Dynamic: { // FIXME: Can this actually happen? We have no test coverage for it. assert(isa(E) && "CK_Dynamic without a dynamic_cast?"); LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(), CodeGenFunction::TCK_Load); // FIXME: Do we also need to handle property references here? if (LV.isSimple()) CGF.EmitDynamicCast(LV.getAddress(), cast(E)); else CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast"); if (!Dest.isIgnored()) CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination"); break; } case CK_ToUnion: { if (Dest.isIgnored()) break; // GCC union extension QualType Ty = E->getSubExpr()->getType(); QualType PtrTy = CGF.getContext().getPointerType(Ty); llvm::Value *CastPtr = Builder.CreateBitCast(Dest.getAddr(), CGF.ConvertType(PtrTy)); EmitInitializationToLValue(E->getSubExpr(), CGF.MakeAddrLValue(CastPtr, Ty)); break; } case CK_DerivedToBase: case CK_BaseToDerived: case CK_UncheckedDerivedToBase: { llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: " "should have been unpacked before we got here"); } case CK_NonAtomicToAtomic: case CK_AtomicToNonAtomic: { bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic); // Determine the atomic and value types. QualType atomicType = E->getSubExpr()->getType(); QualType valueType = E->getType(); if (isToAtomic) std::swap(atomicType, valueType); assert(atomicType->isAtomicType()); assert(CGF.getContext().hasSameUnqualifiedType(valueType, atomicType->castAs()->getValueType())); // Just recurse normally if we're ignoring the result or the // atomic type doesn't change representation. if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) { return Visit(E->getSubExpr()); } CastKind peepholeTarget = (isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic); // These two cases are reverses of each other; try to peephole them. if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) { assert(CGF.getContext().hasSameUnqualifiedType(op->getType(), E->getType()) && "peephole significantly changed types?"); return Visit(op); } // If we're converting an r-value of non-atomic type to an r-value // of atomic type, just emit directly into the relevant sub-object. if (isToAtomic) { AggValueSlot valueDest = Dest; if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) { // Zero-initialize. (Strictly speaking, we only need to intialize // the padding at the end, but this is simpler.) if (!Dest.isZeroed()) CGF.EmitNullInitialization(Dest.getAddr(), atomicType); // Build a GEP to refer to the subobject. llvm::Value *valueAddr = CGF.Builder.CreateStructGEP(valueDest.getAddr(), 0); valueDest = AggValueSlot::forAddr(valueAddr, valueDest.getAlignment(), valueDest.getQualifiers(), valueDest.isExternallyDestructed(), valueDest.requiresGCollection(), valueDest.isPotentiallyAliased(), AggValueSlot::IsZeroed); } CGF.EmitAggExpr(E->getSubExpr(), valueDest); return; } // Otherwise, we're converting an atomic type to a non-atomic type. // Make an atomic temporary, emit into that, and then copy the value out. AggValueSlot atomicSlot = CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp"); CGF.EmitAggExpr(E->getSubExpr(), atomicSlot); llvm::Value *valueAddr = Builder.CreateStructGEP(atomicSlot.getAddr(), 0); RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile()); return EmitFinalDestCopy(valueType, rvalue); } case CK_LValueToRValue: // If we're loading from a volatile type, force the destination // into existence. if (E->getSubExpr()->getType().isVolatileQualified()) { EnsureDest(E->getType()); return Visit(E->getSubExpr()); } // fallthrough case CK_NoOp: case CK_UserDefinedConversion: case CK_ConstructorConversion: assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(), E->getType()) && "Implicit cast types must be compatible"); Visit(E->getSubExpr()); break; case CK_LValueBitCast: llvm_unreachable("should not be emitting lvalue bitcast as rvalue"); case CK_Dependent: case CK_BitCast: case CK_ArrayToPointerDecay: case CK_FunctionToPointerDecay: case CK_NullToPointer: case CK_NullToMemberPointer: case CK_BaseToDerivedMemberPointer: case CK_DerivedToBaseMemberPointer: case CK_MemberPointerToBoolean: case CK_ReinterpretMemberPointer: case CK_IntegralToPointer: case CK_PointerToIntegral: case CK_PointerToBoolean: case CK_ToVoid: case CK_VectorSplat: case CK_IntegralCast: case CK_IntegralToBoolean: case CK_IntegralToFloating: case CK_FloatingToIntegral: case CK_FloatingToBoolean: case CK_FloatingCast: case CK_CPointerToObjCPointerCast: case CK_BlockPointerToObjCPointerCast: case CK_AnyPointerToBlockPointerCast: case CK_ObjCObjectLValueCast: case CK_FloatingRealToComplex: case CK_FloatingComplexToReal: case CK_FloatingComplexToBoolean: case CK_FloatingComplexCast: case CK_FloatingComplexToIntegralComplex: case CK_IntegralRealToComplex: case CK_IntegralComplexToReal: case CK_IntegralComplexToBoolean: case CK_IntegralComplexCast: case CK_IntegralComplexToFloatingComplex: case CK_ARCProduceObject: case CK_ARCConsumeObject: case CK_ARCReclaimReturnedObject: case CK_ARCExtendBlockObject: case CK_CopyAndAutoreleaseBlockObject: case CK_BuiltinFnToFnPtr: case CK_ZeroToOCLEvent: llvm_unreachable("cast kind invalid for aggregate types"); } } void AggExprEmitter::VisitCallExpr(const CallExpr *E) { if (E->getCallReturnType()->isReferenceType()) { EmitAggLoadOfLValue(E); return; } RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot()); EmitMoveFromReturnSlot(E, RV); } void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot()); EmitMoveFromReturnSlot(E, RV); } void AggExprEmitter::VisitBinComma(const BinaryOperator *E) { CGF.EmitIgnoredExpr(E->getLHS()); Visit(E->getRHS()); } void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) { CodeGenFunction::StmtExprEvaluation eval(CGF); CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest); } void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) { if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI) VisitPointerToDataMemberBinaryOperator(E); else CGF.ErrorUnsupported(E, "aggregate binary expression"); } void AggExprEmitter::VisitPointerToDataMemberBinaryOperator( const BinaryOperator *E) { LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E); EmitFinalDestCopy(E->getType(), LV); } /// Is the value of the given expression possibly a reference to or /// into a __block variable? static bool isBlockVarRef(const Expr *E) { // Make sure we look through parens. E = E->IgnoreParens(); // Check for a direct reference to a __block variable. if (const DeclRefExpr *DRE = dyn_cast(E)) { const VarDecl *var = dyn_cast(DRE->getDecl()); return (var && var->hasAttr()); } // More complicated stuff. // Binary operators. if (const BinaryOperator *op = dyn_cast(E)) { // For an assignment or pointer-to-member operation, just care // about the LHS. if (op->isAssignmentOp() || op->isPtrMemOp()) return isBlockVarRef(op->getLHS()); // For a comma, just care about the RHS. if (op->getOpcode() == BO_Comma) return isBlockVarRef(op->getRHS()); // FIXME: pointer arithmetic? return false; // Check both sides of a conditional operator. } else if (const AbstractConditionalOperator *op = dyn_cast(E)) { return isBlockVarRef(op->getTrueExpr()) || isBlockVarRef(op->getFalseExpr()); // OVEs are required to support BinaryConditionalOperators. } else if (const OpaqueValueExpr *op = dyn_cast(E)) { if (const Expr *src = op->getSourceExpr()) return isBlockVarRef(src); // Casts are necessary to get things like (*(int*)&var) = foo(). // We don't really care about the kind of cast here, except // we don't want to look through l2r casts, because it's okay // to get the *value* in a __block variable. } else if (const CastExpr *cast = dyn_cast(E)) { if (cast->getCastKind() == CK_LValueToRValue) return false; return isBlockVarRef(cast->getSubExpr()); // Handle unary operators. Again, just aggressively look through // it, ignoring the operation. } else if (const UnaryOperator *uop = dyn_cast(E)) { return isBlockVarRef(uop->getSubExpr()); // Look into the base of a field access. } else if (const MemberExpr *mem = dyn_cast(E)) { return isBlockVarRef(mem->getBase()); // Look into the base of a subscript. } else if (const ArraySubscriptExpr *sub = dyn_cast(E)) { return isBlockVarRef(sub->getBase()); } return false; } void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) { // For an assignment to work, the value on the right has // to be compatible with the value on the left. assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(), E->getRHS()->getType()) && "Invalid assignment"); // If the LHS might be a __block variable, and the RHS can // potentially cause a block copy, we need to evaluate the RHS first // so that the assignment goes the right place. // This is pretty semantically fragile. if (isBlockVarRef(E->getLHS()) && E->getRHS()->HasSideEffects(CGF.getContext())) { // Ensure that we have a destination, and evaluate the RHS into that. EnsureDest(E->getRHS()->getType()); Visit(E->getRHS()); // Now emit the LHS and copy into it. LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); // That copy is an atomic copy if the LHS is atomic. if (LHS.getType()->isAtomicType()) { CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); return; } EmitCopy(E->getLHS()->getType(), AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()), AggValueSlot::IsAliased), Dest); return; } LValue LHS = CGF.EmitLValue(E->getLHS()); // If we have an atomic type, evaluate into the destination and then // do an atomic copy. if (LHS.getType()->isAtomicType()) { EnsureDest(E->getRHS()->getType()); Visit(E->getRHS()); CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); return; } // Codegen the RHS so that it stores directly into the LHS. AggValueSlot LHSSlot = AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()), AggValueSlot::IsAliased); // A non-volatile aggregate destination might have volatile member. if (!LHSSlot.isVolatile() && CGF.hasVolatileMember(E->getLHS()->getType())) LHSSlot.setVolatile(true); CGF.EmitAggExpr(E->getRHS(), LHSSlot); // Copy into the destination if the assignment isn't ignored. EmitFinalDestCopy(E->getType(), LHS); } void AggExprEmitter:: VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); // Bind the common expression if necessary. CodeGenFunction::OpaqueValueMapping binding(CGF, E); CodeGenFunction::ConditionalEvaluation eval(CGF); CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); // Save whether the destination's lifetime is externally managed. bool isExternallyDestructed = Dest.isExternallyDestructed(); eval.begin(CGF); CGF.EmitBlock(LHSBlock); Visit(E->getTrueExpr()); eval.end(CGF); assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!"); CGF.Builder.CreateBr(ContBlock); // If the result of an agg expression is unused, then the emission // of the LHS might need to create a destination slot. That's fine // with us, and we can safely emit the RHS into the same slot, but // we shouldn't claim that it's already being destructed. Dest.setExternallyDestructed(isExternallyDestructed); eval.begin(CGF); CGF.EmitBlock(RHSBlock); Visit(E->getFalseExpr()); eval.end(CGF); CGF.EmitBlock(ContBlock); } void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) { Visit(CE->getChosenSubExpr()); } void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); if (!ArgPtr) { CGF.ErrorUnsupported(VE, "aggregate va_arg expression"); return; } EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType())); } void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { // Ensure that we have a slot, but if we already do, remember // whether it was externally destructed. bool wasExternallyDestructed = Dest.isExternallyDestructed(); EnsureDest(E->getType()); // We're going to push a destructor if there isn't already one. Dest.setExternallyDestructed(); Visit(E->getSubExpr()); // Push that destructor we promised. if (!wasExternallyDestructed) CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddr()); } void AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitCXXConstructExpr(E, Slot); } void AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitLambdaExpr(E, Slot); } void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) { CGF.enterFullExpression(E); CodeGenFunction::RunCleanupsScope cleanups(CGF); Visit(E->getSubExpr()); } void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) { QualType T = E->getType(); AggValueSlot Slot = EnsureSlot(T); EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T)); } void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) { QualType T = E->getType(); AggValueSlot Slot = EnsureSlot(T); EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T)); } /// isSimpleZero - If emitting this value will obviously just cause a store of /// zero to memory, return true. This can return false if uncertain, so it just /// handles simple cases. static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) { E = E->IgnoreParens(); // 0 if (const IntegerLiteral *IL = dyn_cast(E)) return IL->getValue() == 0; // +0.0 if (const FloatingLiteral *FL = dyn_cast(E)) return FL->getValue().isPosZero(); // int() if ((isa(E) || isa(E)) && CGF.getTypes().isZeroInitializable(E->getType())) return true; // (int*)0 - Null pointer expressions. if (const CastExpr *ICE = dyn_cast(E)) return ICE->getCastKind() == CK_NullToPointer; // '\0' if (const CharacterLiteral *CL = dyn_cast(E)) return CL->getValue() == 0; // Otherwise, hard case: conservatively return false. return false; } void AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) { QualType type = LV.getType(); // FIXME: Ignore result? // FIXME: Are initializers affected by volatile? if (Dest.isZeroed() && isSimpleZero(E, CGF)) { // Storing "i32 0" to a zero'd memory location is a noop. return; } else if (isa(E) || isa(E)) { return EmitNullInitializationToLValue(LV); } else if (type->isReferenceType()) { RValue RV = CGF.EmitReferenceBindingToExpr(E); return CGF.EmitStoreThroughLValue(RV, LV); } switch (CGF.getEvaluationKind(type)) { case TEK_Complex: CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true); return; case TEK_Aggregate: CGF.EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, Dest.isZeroed())); return; case TEK_Scalar: if (LV.isSimple()) { CGF.EmitScalarInit(E, /*D=*/0, LV, /*Captured=*/false); } else { CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV); } return; } llvm_unreachable("bad evaluation kind"); } void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) { QualType type = lv.getType(); // If the destination slot is already zeroed out before the aggregate is // copied into it, we don't have to emit any zeros here. if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type)) return; if (CGF.hasScalarEvaluationKind(type)) { // For non-aggregates, we can store the appropriate null constant. llvm::Value *null = CGF.CGM.EmitNullConstant(type); // Note that the following is not equivalent to // EmitStoreThroughBitfieldLValue for ARC types. if (lv.isBitField()) { CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv); } else { assert(lv.isSimple()); CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true); } } else { // There's a potential optimization opportunity in combining // memsets; that would be easy for arrays, but relatively // difficult for structures with the current code. CGF.EmitNullInitialization(lv.getAddress(), lv.getType()); } } void AggExprEmitter::VisitInitListExpr(InitListExpr *E) { #if 0 // FIXME: Assess perf here? Figure out what cases are worth optimizing here // (Length of globals? Chunks of zeroed-out space?). // // If we can, prefer a copy from a global; this is a lot less code for long // globals, and it's easier for the current optimizers to analyze. if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) { llvm::GlobalVariable* GV = new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true, llvm::GlobalValue::InternalLinkage, C, ""); EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType())); return; } #endif if (E->hadArrayRangeDesignator()) CGF.ErrorUnsupported(E, "GNU array range designator extension"); AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(), Dest.getAlignment()); // Handle initialization of an array. if (E->getType()->isArrayType()) { if (E->isStringLiteralInit()) return Visit(E->getInit(0)); QualType elementType = CGF.getContext().getAsArrayType(E->getType())->getElementType(); llvm::PointerType *APType = cast(Dest.getAddr()->getType()); llvm::ArrayType *AType = cast(APType->getElementType()); EmitArrayInit(Dest.getAddr(), AType, elementType, E); return; } assert(E->getType()->isRecordType() && "Only support structs/unions here!"); // Do struct initialization; this code just sets each individual member // to the approprate value. This makes bitfield support automatic; // the disadvantage is that the generated code is more difficult for // the optimizer, especially with bitfields. unsigned NumInitElements = E->getNumInits(); RecordDecl *record = E->getType()->castAs()->getDecl(); // Prepare a 'this' for CXXDefaultInitExprs. CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddr()); if (record->isUnion()) { // Only initialize one field of a union. The field itself is // specified by the initializer list. if (!E->getInitializedFieldInUnion()) { // Empty union; we have nothing to do. #ifndef NDEBUG // Make sure that it's really an empty and not a failure of // semantic analysis. for (RecordDecl::field_iterator Field = record->field_begin(), FieldEnd = record->field_end(); Field != FieldEnd; ++Field) assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed"); #endif return; } // FIXME: volatility FieldDecl *Field = E->getInitializedFieldInUnion(); LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field); if (NumInitElements) { // Store the initializer into the field EmitInitializationToLValue(E->getInit(0), FieldLoc); } else { // Default-initialize to null. EmitNullInitializationToLValue(FieldLoc); } return; } // We'll need to enter cleanup scopes in case any of the member // initializers throw an exception. SmallVector cleanups; llvm::Instruction *cleanupDominator = 0; // Here we iterate over the fields; this makes it simpler to both // default-initialize fields and skip over unnamed fields. unsigned curInitIndex = 0; for (RecordDecl::field_iterator field = record->field_begin(), fieldEnd = record->field_end(); field != fieldEnd; ++field) { // We're done once we hit the flexible array member. if (field->getType()->isIncompleteArrayType()) break; // Always skip anonymous bitfields. if (field->isUnnamedBitfield()) continue; // We're done if we reach the end of the explicit initializers, we // have a zeroed object, and the rest of the fields are // zero-initializable. if (curInitIndex == NumInitElements && Dest.isZeroed() && CGF.getTypes().isZeroInitializable(E->getType())) break; LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, *field); // We never generate write-barries for initialized fields. LV.setNonGC(true); if (curInitIndex < NumInitElements) { // Store the initializer into the field. EmitInitializationToLValue(E->getInit(curInitIndex++), LV); } else { // We're out of initalizers; default-initialize to null EmitNullInitializationToLValue(LV); } // Push a destructor if necessary. // FIXME: if we have an array of structures, all explicitly // initialized, we can end up pushing a linear number of cleanups. bool pushedCleanup = false; if (QualType::DestructionKind dtorKind = field->getType().isDestructedType()) { assert(LV.isSimple()); if (CGF.needsEHCleanup(dtorKind)) { if (!cleanupDominator) cleanupDominator = CGF.Builder.CreateUnreachable(); // placeholder CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(), CGF.getDestroyer(dtorKind), false); cleanups.push_back(CGF.EHStack.stable_begin()); pushedCleanup = true; } } // If the GEP didn't get used because of a dead zero init or something // else, clean it up for -O0 builds and general tidiness. if (!pushedCleanup && LV.isSimple()) if (llvm::GetElementPtrInst *GEP = dyn_cast(LV.getAddress())) if (GEP->use_empty()) GEP->eraseFromParent(); } // Deactivate all the partial cleanups in reverse order, which // generally means popping them. for (unsigned i = cleanups.size(); i != 0; --i) CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator); // Destroy the placeholder if we made one. if (cleanupDominator) cleanupDominator->eraseFromParent(); } //===----------------------------------------------------------------------===// // Entry Points into this File //===----------------------------------------------------------------------===// /// GetNumNonZeroBytesInInit - Get an approximate count of the number of /// non-zero bytes that will be stored when outputting the initializer for the /// specified initializer expression. static CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF) { E = E->IgnoreParens(); // 0 and 0.0 won't require any non-zero stores! if (isSimpleZero(E, CGF)) return CharUnits::Zero(); // If this is an initlist expr, sum up the size of sizes of the (present) // elements. If this is something weird, assume the whole thing is non-zero. const InitListExpr *ILE = dyn_cast(E); if (ILE == 0 || !CGF.getTypes().isZeroInitializable(ILE->getType())) return CGF.getContext().getTypeSizeInChars(E->getType()); // InitListExprs for structs have to be handled carefully. If there are // reference members, we need to consider the size of the reference, not the // referencee. InitListExprs for unions and arrays can't have references. if (const RecordType *RT = E->getType()->getAs()) { if (!RT->isUnionType()) { RecordDecl *SD = E->getType()->getAs()->getDecl(); CharUnits NumNonZeroBytes = CharUnits::Zero(); unsigned ILEElement = 0; for (RecordDecl::field_iterator Field = SD->field_begin(), FieldEnd = SD->field_end(); Field != FieldEnd; ++Field) { // We're done once we hit the flexible array member or run out of // InitListExpr elements. if (Field->getType()->isIncompleteArrayType() || ILEElement == ILE->getNumInits()) break; if (Field->isUnnamedBitfield()) continue; const Expr *E = ILE->getInit(ILEElement++); // Reference values are always non-null and have the width of a pointer. if (Field->getType()->isReferenceType()) NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits( CGF.getTarget().getPointerWidth(0)); else NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF); } return NumNonZeroBytes; } } CharUnits NumNonZeroBytes = CharUnits::Zero(); for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF); return NumNonZeroBytes; } /// CheckAggExprForMemSetUse - If the initializer is large and has a lot of /// zeros in it, emit a memset and avoid storing the individual zeros. /// static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E, CodeGenFunction &CGF) { // If the slot is already known to be zeroed, nothing to do. Don't mess with // volatile stores. if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == 0) return; // C++ objects with a user-declared constructor don't need zero'ing. if (CGF.getLangOpts().CPlusPlus) if (const RecordType *RT = CGF.getContext() .getBaseElementType(E->getType())->getAs()) { const CXXRecordDecl *RD = cast(RT->getDecl()); if (RD->hasUserDeclaredConstructor()) return; } // If the type is 16-bytes or smaller, prefer individual stores over memset. std::pair TypeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); if (TypeInfo.first <= CharUnits::fromQuantity(16)) return; // Check to see if over 3/4 of the initializer are known to be zero. If so, // we prefer to emit memset + individual stores for the rest. CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF); if (NumNonZeroBytes*4 > TypeInfo.first) return; // Okay, it seems like a good idea to use an initial memset, emit the call. llvm::Constant *SizeVal = CGF.Builder.getInt64(TypeInfo.first.getQuantity()); CharUnits Align = TypeInfo.second; llvm::Value *Loc = Slot.getAddr(); Loc = CGF.Builder.CreateBitCast(Loc, CGF.Int8PtrTy); CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, Align.getQuantity(), false); // Tell the AggExprEmitter that the slot is known zero. Slot.setZeroed(); } /// EmitAggExpr - Emit the computation of the specified expression of aggregate /// type. The result is computed into DestPtr. Note that if DestPtr is null, /// the value of the aggregate expression is not needed. If VolatileDest is /// true, DestPtr cannot be 0. void CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot) { assert(E && hasAggregateEvaluationKind(E->getType()) && "Invalid aggregate expression to emit"); assert((Slot.getAddr() != 0 || Slot.isIgnored()) && "slot has bits but no address"); // Optimize the slot if possible. CheckAggExprForMemSetUse(Slot, E, *this); AggExprEmitter(*this, Slot).Visit(const_cast(E)); } LValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) { assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!"); llvm::Value *Temp = CreateMemTemp(E->getType()); LValue LV = MakeAddrLValue(Temp, E->getType()); EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased)); return LV; } void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr, llvm::Value *SrcPtr, QualType Ty, bool isVolatile, CharUnits alignment, bool isAssignment) { assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); if (getLangOpts().CPlusPlus) { if (const RecordType *RT = Ty->getAs()) { CXXRecordDecl *Record = cast(RT->getDecl()); assert((Record->hasTrivialCopyConstructor() || Record->hasTrivialCopyAssignment() || Record->hasTrivialMoveConstructor() || Record->hasTrivialMoveAssignment()) && "Trying to aggregate-copy a type without a trivial copy/move " "constructor or assignment operator"); // Ignore empty classes in C++. if (Record->isEmpty()) return; } } // Aggregate assignment turns into llvm.memcpy. This is almost valid per // C99 6.5.16.1p3, which states "If the value being stored in an object is // read from another object that overlaps in anyway the storage of the first // object, then the overlap shall be exact and the two objects shall have // qualified or unqualified versions of a compatible type." // // memcpy is not defined if the source and destination pointers are exactly // equal, but other compilers do this optimization, and almost every memcpy // implementation handles this case safely. If there is a libc that does not // safely handle this, we can add a target hook. // Get data size and alignment info for this aggregate. If this is an // assignment don't copy the tail padding. Otherwise copying it is fine. std::pair TypeInfo; if (isAssignment) TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty); else TypeInfo = getContext().getTypeInfoInChars(Ty); if (alignment.isZero()) alignment = TypeInfo.second; // FIXME: Handle variable sized types. // FIXME: If we have a volatile struct, the optimizer can remove what might // appear to be `extra' memory ops: // // volatile struct { int i; } a, b; // // int main() { // a = b; // a = b; // } // // we need to use a different call here. We use isVolatile to indicate when // either the source or the destination is volatile. llvm::PointerType *DPT = cast(DestPtr->getType()); llvm::Type *DBP = llvm::Type::getInt8PtrTy(getLLVMContext(), DPT->getAddressSpace()); DestPtr = Builder.CreateBitCast(DestPtr, DBP); llvm::PointerType *SPT = cast(SrcPtr->getType()); llvm::Type *SBP = llvm::Type::getInt8PtrTy(getLLVMContext(), SPT->getAddressSpace()); SrcPtr = Builder.CreateBitCast(SrcPtr, SBP); // Don't do any of the memmove_collectable tests if GC isn't set. if (CGM.getLangOpts().getGC() == LangOptions::NonGC) { // fall through } else if (const RecordType *RecordTy = Ty->getAs()) { RecordDecl *Record = RecordTy->getDecl(); if (Record->hasObjectMember()) { CharUnits size = TypeInfo.first; llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity()); CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, SizeVal); return; } } else if (Ty->isArrayType()) { QualType BaseType = getContext().getBaseElementType(Ty); if (const RecordType *RecordTy = BaseType->getAs()) { if (RecordTy->getDecl()->hasObjectMember()) { CharUnits size = TypeInfo.first; llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity()); CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, SizeVal); return; } } } // Determine the metadata to describe the position of any padding in this // memcpy, as well as the TBAA tags for the members of the struct, in case // the optimizer wishes to expand it in to scalar memory operations. llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty); Builder.CreateMemCpy(DestPtr, SrcPtr, llvm::ConstantInt::get(IntPtrTy, TypeInfo.first.getQuantity()), alignment.getQuantity(), isVolatile, /*TBAATag=*/0, TBAAStructTag); } @ 1.1.1.1 log @Import Clang 3.4rc1 r195771. @ text @@ 1.1.1.2 log @Import clang 3.5svn r198450. @ text @a715 1 case CK_AddressSpaceConversion: @ 1.1.1.3 log @Import Clang 3.5svn r199312 @ text @a894 1 RegionCounter Cnt = CGF.getPGORegionCounter(E); d896 1 a896 1 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, Cnt.getCount()); a902 1 Cnt.beginRegion(Builder); a903 1 Cnt.adjustForControlFlow(); a916 1 Cnt.beginElseRegion(); a917 1 Cnt.adjustForControlFlow(); a920 1 Cnt.applyAdjustmentsToRegion(); @ 1.1.1.4 log @Import Clang 3.5svn r201163. @ text @d938 1 a938 5 // If EmitVAArg fails, we fall back to the LLVM instruction. llvm::Value *Val = Builder.CreateVAArg(ArgValue, CGF.ConvertType(VE->getType())); if (!Dest.isIgnored()) Builder.CreateStore(Val, Dest.getAddr()); @ 1.1.1.5 log @Import Clang 3.5svn r202566. @ text @d906 1 d920 1 d922 1 d926 1 @ 1.1.1.5.2.1 log @Rebase. @ text @d392 1 a392 1 llvm::AllocaInst *endOfInit = nullptr; d394 1 a394 1 llvm::Instruction *cleanupDominator = nullptr; d542 1 a542 1 return nullptr; d1047 1 a1047 1 CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false); d1144 3 a1146 1 for (const auto *Field : record->fields()) d1170 1 a1170 1 llvm::Instruction *cleanupDominator = nullptr; d1175 3 a1177 1 for (const auto *field : record->fields()) { d1194 1 a1194 1 LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field); d1259 1 a1259 1 if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType())) d1271 2 a1272 1 for (const auto *Field : SD->fields()) { d1309 1 a1309 2 if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == nullptr) return; d1356 1 a1356 1 assert((Slot.getAddr() != nullptr || Slot.isIgnored()) && d1476 1 a1476 1 d1481 1 a1481 1 /*TBAATag=*/nullptr, TBAAStructTag); @ 1.1.1.6 log @Import Clang 3.5svn r209886. @ text @d392 1 a392 1 llvm::AllocaInst *endOfInit = nullptr; d394 1 a394 1 llvm::Instruction *cleanupDominator = nullptr; d542 1 a542 1 return nullptr; d1047 1 a1047 1 CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false); d1144 3 a1146 1 for (const auto *Field : record->fields()) d1170 1 a1170 1 llvm::Instruction *cleanupDominator = nullptr; d1175 3 a1177 1 for (const auto *field : record->fields()) { d1194 1 a1194 1 LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field); d1259 1 a1259 1 if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType())) d1271 2 a1272 1 for (const auto *Field : SD->fields()) { d1309 1 a1309 2 if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == nullptr) return; d1356 1 a1356 1 assert((Slot.getAddr() != nullptr || Slot.isIgnored()) && d1476 1 a1476 1 d1481 1 a1481 1 /*TBAATag=*/nullptr, TBAAStructTag); @ 1.1.1.7 log @Import clang 3.6svn r215315. @ text @a372 23 /// \brief Determine if E is a trivial array filler, that is, one that is /// equivalent to zero-initialization. static bool isTrivialFiller(Expr *E) { if (!E) return true; if (isa(E)) return true; if (auto *ILE = dyn_cast(E)) { if (ILE->getNumInits()) return false; return isTrivialFiller(ILE->getArrayFiller()); } if (auto *Cons = dyn_cast_or_null(E)) return Cons->getConstructor()->isDefaultConstructor() && Cons->getConstructor()->isTrivial(); // FIXME: Are there other cases where we can avoid emitting an initializer? return false; } d438 2 d441 5 a445 1 bool hasTrivialFiller = isTrivialFiller(filler); a1122 10 if (E->getType()->isAtomicType()) { // An _Atomic(T) object can be list-initialized from an expression // of the same type. assert(E->getNumInits() == 1 && CGF.getContext().hasSameUnqualifiedType(E->getInit(0)->getType(), E->getType()) && "unexpected list initialization for atomic object"); return Visit(E->getInit(0)); } @ 1.1.1.8 log @Import Clang 3.8.0rc3 r261930. @ text @a36 1 bool IsResultUnused; d51 1 a51 2 return ReturnValueSlot(Dest.getAddress(), Dest.isVolatile(), IsResultUnused); d64 3 a66 3 AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest, bool IsResultUnused) : CGF(cgf), Builder(CGF.Builder), Dest(Dest), IsResultUnused(IsResultUnused) { } d79 2 a80 1 void EmitFinalDestCopy(QualType type, RValue src); d86 1 a86 1 void EmitArrayInit(Address DestPtr, llvm::ArrayType *AType, a100 5 void Visit(Expr *E) { ApplyDebugLocation DL(CGF, E); StmtVisitor::Visit(E); } a156 1 void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E); a160 1 void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing. d194 1 a194 2 RValue Res = CGF.EmitAtomicExpr(E); EmitFinalDestCopy(E->getType(), Res); d210 1 a210 1 if (LV.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LV)) { d254 4 a257 2 assert(Dest.getPointer() != src.getAggregatePointer()); EmitFinalDestCopy(E->getType(), src); d261 2 a262 1 void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) { d264 1 a264 1 LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type); d293 2 a294 2 dest.getAddress(), src.getAddress(), d302 3 a304 2 CGF.EmitAggregateCopy(dest.getAddress(), src.getAddress(), type, dest.isVolatile() || src.isVolatile()); d316 1 a316 1 Address ArrayPtr = Array.getAddress(); d339 2 a340 1 LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); d345 1 a345 1 Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxStart, "arraystart"); d362 1 a362 1 Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxEnd, "arrayend"); d397 1 a397 1 void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType, d409 1 a409 5 Builder.CreateInBoundsGEP(DestPtr.getPointer(), indices, "arrayinit.begin"); CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType); CharUnits elementAlign = DestPtr.getAlignment().alignmentOfArrayElement(elementSize); d415 1 a415 1 Address endOfInit = Address::invalid(); d423 1 a423 1 endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(), a426 1 elementAlign, d453 1 a453 1 if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit); d456 1 a456 2 LValue elementLV = CGF.MakeAddrLValue(Address(element, elementAlign), elementType); d477 1 a477 1 if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit); d495 1 a495 2 LValue elementLV = CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType); d506 1 a506 1 if (endOfInit.isValid()) Builder.CreateStore(nextElement, endOfInit); a563 2 if (const auto *ECE = dyn_cast(E)) CGF.CGM.EmitExplicitCastExprType(ECE, &CGF); d582 1 a582 6 // Evaluate even if the destination is ignored. if (Dest.isIgnored()) { CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(), /*ignoreResult=*/true); break; } d586 3 a588 2 Address CastPtr = Builder.CreateElementBitCast(Dest.getAddress(), CGF.ConvertType(Ty)); d639 1 a639 1 CGF.EmitNullInitialization(Dest.getAddress(), atomicType); d642 2 a643 3 Address valueAddr = CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0, CharUnits()); d645 1 d663 2 a664 2 Address valueAddr = Builder.CreateStructGEP(atomicSlot.getAddress(), 0, CharUnits()); a706 1 case CK_BooleanToSignedIntegral: d739 1 a739 1 if (E->getCallReturnType(CGF.getContext())->isReferenceType()) { d863 1 a863 2 if (LHS.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LHS)) { d880 1 a880 2 if (LHS.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LHS)) { d912 1 d914 1 a914 2 CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, CGF.getProfileCount(E)); d921 1 a921 1 CGF.incrementProfileCounter(E); d947 2 a948 2 Address ArgValue = Address::invalid(); Address ArgPtr = CGF.EmitVAArg(VE, ArgValue); d950 1 a950 1 if (!ArgPtr.isValid()) { d952 2 a953 2 llvm::Value *Val = Builder.CreateVAArg(ArgValue.getPointer(), CGF.ConvertType(VE->getType())); d955 1 a955 1 Builder.CreateStore(Val, Dest.getAddress()); d975 1 a975 1 CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddress()); d999 1 a999 1 EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T)); d1005 1 a1005 1 EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T)); a1045 3 } else if (isa(E)) { // Do nothing. return; d1120 2 a1121 1 LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); d1131 6 a1136 2 auto AType = cast(Dest.getAddress().getElementType()); EmitArrayInit(Dest.getAddress(), AType, elementType, E); d1160 1 a1160 1 CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddress()); d1238 1 a1238 4 cleanupDominator = CGF.Builder.CreateAlignedLoad( CGF.Int8Ty, llvm::Constant::getNullValue(CGF.Int8PtrTy), CharUnits::One()); // placeholder d1251 1 a1251 1 dyn_cast(LV.getPointer())) a1265 8 void AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) { AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); EmitInitializationToLValue(E->getBase(), DestLV); VisitInitListExpr(E->getUpdater()); } d1331 1 a1331 1 if (Slot.isZeroed() || Slot.isVolatile() || !Slot.getAddress().isValid()) d1344 3 a1346 2 CharUnits Size = CGF.getContext().getTypeSizeInChars(E->getType()); if (Size <= CharUnits::fromQuantity(16)) d1352 1 a1352 1 if (NumNonZeroBytes*4 > Size) d1356 2 a1357 1 llvm::Constant *SizeVal = CGF.Builder.getInt64(Size.getQuantity()); d1359 5 a1363 3 Address Loc = Slot.getAddress(); Loc = CGF.Builder.CreateElementBitCast(Loc, CGF.Int8Ty); CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, false); d1379 1 a1379 1 assert((Slot.getAddress().isValid() || Slot.isIgnored()) && d1385 1 a1385 1 AggExprEmitter(*this, Slot, Slot.isIgnored()).Visit(const_cast(E)); d1390 1 a1390 1 Address Temp = CreateMemTemp(E->getType()); d1398 2 a1399 2 void CodeGenFunction::EmitAggregateCopy(Address DestPtr, Address SrcPtr, QualType Ty, d1401 1 d1411 1 a1411 2 Record->hasTrivialMoveAssignment() || Record->isUnion()) && d1431 2 a1432 4 // Get data size info for this aggregate. If this is an assignment, // don't copy the tail padding, because we might be assigning into a // base subobject where the tail padding is claimed. Otherwise, // copying it is fine. d1439 4 a1442 28 llvm::Value *SizeVal = nullptr; if (TypeInfo.first.isZero()) { // But note that getTypeInfo returns 0 for a VLA. if (auto *VAT = dyn_cast_or_null( getContext().getAsArrayType(Ty))) { QualType BaseEltTy; SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr); TypeInfo = getContext().getTypeInfoDataSizeInChars(BaseEltTy); std::pair LastElementTypeInfo; if (!isAssignment) LastElementTypeInfo = getContext().getTypeInfoInChars(BaseEltTy); assert(!TypeInfo.first.isZero()); SizeVal = Builder.CreateNUWMul( SizeVal, llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity())); if (!isAssignment) { SizeVal = Builder.CreateNUWSub( SizeVal, llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity())); SizeVal = Builder.CreateNUWAdd( SizeVal, llvm::ConstantInt::get( SizeTy, LastElementTypeInfo.first.getQuantity())); } } } if (!SizeVal) { SizeVal = llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity()); } d1457 9 a1465 2 DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty); SrcPtr = Builder.CreateElementBitCast(SrcPtr, Int8Ty); d1473 3 d1484 4 a1494 2 auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile); d1498 7 a1504 2 if (llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty)) Inst->setMetadata(llvm::LLVMContext::MD_tbaa_struct, TBAAStructTag); @ 1.1.1.8.2.1 log @Sync with HEAD @ text @a166 2 void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E, llvm::Value *outerBegin = nullptr); a177 1 void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E); a750 1 case CK_ZeroToOCLQueue: a751 1 case CK_IntToOCLSampler: a1003 8 void AggExprEmitter::VisitCXXInheritedCtorInitExpr( const CXXInheritedCtorInitExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitInheritedCXXConstructorCall( E->getConstructor(), E->constructsVBase(), Slot.getAddress(), E->inheritedFromVBase(), E); } d1046 1 a1046 2 return ICE->getCastKind() == CK_NullToPointer && CGF.getTypes().isPointerZeroInitializable(E->getType()); a1140 3 if (E->isTransparent()) return Visit(E->getInit(0)); d1147 3 d1158 10 a1176 32 // We'll need to enter cleanup scopes in case any of the element // initializers throws an exception. SmallVector cleanups; llvm::Instruction *cleanupDominator = nullptr; unsigned curInitIndex = 0; // Emit initialization of base classes. if (auto *CXXRD = dyn_cast(record)) { assert(E->getNumInits() >= CXXRD->getNumBases() && "missing initializer for base class"); for (auto &Base : CXXRD->bases()) { assert(!Base.isVirtual() && "should not see vbases here"); auto *BaseRD = Base.getType()->getAsCXXRecordDecl(); Address V = CGF.GetAddressOfDirectBaseInCompleteClass( Dest.getAddress(), CXXRD, BaseRD, /*isBaseVirtual*/ false); AggValueSlot AggSlot = AggValueSlot::forAddr(V, Qualifiers(), AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); CGF.EmitAggExpr(E->getInit(curInitIndex++), AggSlot); if (QualType::DestructionKind dtorKind = Base.getType().isDestructedType()) { CGF.pushDestroy(dtorKind, V, Base.getType()); cleanups.push_back(CGF.EHStack.stable_begin()); } } } d1210 5 d1217 1 a1286 92 void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E, llvm::Value *outerBegin) { // Emit the common subexpression. CodeGenFunction::OpaqueValueMapping binding(CGF, E->getCommonExpr()); Address destPtr = EnsureSlot(E->getType()).getAddress(); uint64_t numElements = E->getArraySize().getZExtValue(); if (!numElements) return; // destPtr is an array*. Construct an elementType* by drilling down a level. llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); llvm::Value *indices[] = {zero, zero}; llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getPointer(), indices, "arrayinit.begin"); // Prepare to special-case multidimensional array initialization: we avoid // emitting multiple destructor loops in that case. if (!outerBegin) outerBegin = begin; ArrayInitLoopExpr *InnerLoop = dyn_cast(E->getSubExpr()); QualType elementType = CGF.getContext().getAsArrayType(E->getType())->getElementType(); CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType); CharUnits elementAlign = destPtr.getAlignment().alignmentOfArrayElement(elementSize); llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body"); // Jump into the body. CGF.EmitBlock(bodyBB); llvm::PHINode *index = Builder.CreatePHI(zero->getType(), 2, "arrayinit.index"); index->addIncoming(zero, entryBB); llvm::Value *element = Builder.CreateInBoundsGEP(begin, index); // Prepare for a cleanup. QualType::DestructionKind dtorKind = elementType.isDestructedType(); EHScopeStack::stable_iterator cleanup; if (CGF.needsEHCleanup(dtorKind) && !InnerLoop) { if (outerBegin->getType() != element->getType()) outerBegin = Builder.CreateBitCast(outerBegin, element->getType()); CGF.pushRegularPartialArrayCleanup(outerBegin, element, elementType, elementAlign, CGF.getDestroyer(dtorKind)); cleanup = CGF.EHStack.stable_begin(); } else { dtorKind = QualType::DK_none; } // Emit the actual filler expression. { // Temporaries created in an array initialization loop are destroyed // at the end of each iteration. CodeGenFunction::RunCleanupsScope CleanupsScope(CGF); CodeGenFunction::ArrayInitLoopExprScope Scope(CGF, index); LValue elementLV = CGF.MakeAddrLValue(Address(element, elementAlign), elementType); if (InnerLoop) { // If the subexpression is an ArrayInitLoopExpr, share its cleanup. auto elementSlot = AggValueSlot::forLValue( elementLV, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); AggExprEmitter(CGF, elementSlot, false) .VisitArrayInitLoopExpr(InnerLoop, outerBegin); } else EmitInitializationToLValue(E->getSubExpr(), elementLV); } // Move on to the next element. llvm::Value *nextIndex = Builder.CreateNUWAdd( index, llvm::ConstantInt::get(CGF.SizeTy, 1), "arrayinit.next"); index->addIncoming(nextIndex, Builder.GetInsertBlock()); // Leave the loop if we're done. llvm::Value *done = Builder.CreateICmpEQ( nextIndex, llvm::ConstantInt::get(CGF.SizeTy, numElements), "arrayinit.done"); llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end"); Builder.CreateCondBr(done, endBB, bodyBB); CGF.EmitBlock(endBB); // Leave the partial-array cleanup if we entered one. if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, index); } a1322 4 if (auto *CXXRD = dyn_cast(SD)) while (ILEElement != CXXRD->getNumBases()) NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(ILEElement++), CGF); @ 1.1.1.9 log @Import Clang 3.8.1+ r280599. @ text @a969 1 // If EmitVAArg fails, emit an error. d971 5 a975 1 CGF.ErrorUnsupported(VE, "aggregate va_arg expression"); @ 1.1.1.10 log @Import Clang pre-4.0.0 r291444. @ text @a166 2 void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E, llvm::Value *outerBegin = nullptr); a177 1 void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E); a750 1 case CK_ZeroToOCLQueue: a751 1 case CK_IntToOCLSampler: a1000 8 void AggExprEmitter::VisitCXXInheritedCtorInitExpr( const CXXInheritedCtorInitExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitInheritedCXXConstructorCall( E->getConstructor(), E->constructsVBase(), Slot.getAddress(), E->inheritedFromVBase(), E); } d1043 1 a1043 2 return ICE->getCastKind() == CK_NullToPointer && CGF.getTypes().isPointerZeroInitializable(E->getType()); a1137 3 if (E->isTransparent()) return Visit(E->getInit(0)); d1144 3 d1155 10 a1173 32 // We'll need to enter cleanup scopes in case any of the element // initializers throws an exception. SmallVector cleanups; llvm::Instruction *cleanupDominator = nullptr; unsigned curInitIndex = 0; // Emit initialization of base classes. if (auto *CXXRD = dyn_cast(record)) { assert(E->getNumInits() >= CXXRD->getNumBases() && "missing initializer for base class"); for (auto &Base : CXXRD->bases()) { assert(!Base.isVirtual() && "should not see vbases here"); auto *BaseRD = Base.getType()->getAsCXXRecordDecl(); Address V = CGF.GetAddressOfDirectBaseInCompleteClass( Dest.getAddress(), CXXRD, BaseRD, /*isBaseVirtual*/ false); AggValueSlot AggSlot = AggValueSlot::forAddr(V, Qualifiers(), AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); CGF.EmitAggExpr(E->getInit(curInitIndex++), AggSlot); if (QualType::DestructionKind dtorKind = Base.getType().isDestructedType()) { CGF.pushDestroy(dtorKind, V, Base.getType()); cleanups.push_back(CGF.EHStack.stable_begin()); } } } d1207 5 d1214 1 a1283 92 void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E, llvm::Value *outerBegin) { // Emit the common subexpression. CodeGenFunction::OpaqueValueMapping binding(CGF, E->getCommonExpr()); Address destPtr = EnsureSlot(E->getType()).getAddress(); uint64_t numElements = E->getArraySize().getZExtValue(); if (!numElements) return; // destPtr is an array*. Construct an elementType* by drilling down a level. llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); llvm::Value *indices[] = {zero, zero}; llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getPointer(), indices, "arrayinit.begin"); // Prepare to special-case multidimensional array initialization: we avoid // emitting multiple destructor loops in that case. if (!outerBegin) outerBegin = begin; ArrayInitLoopExpr *InnerLoop = dyn_cast(E->getSubExpr()); QualType elementType = CGF.getContext().getAsArrayType(E->getType())->getElementType(); CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType); CharUnits elementAlign = destPtr.getAlignment().alignmentOfArrayElement(elementSize); llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body"); // Jump into the body. CGF.EmitBlock(bodyBB); llvm::PHINode *index = Builder.CreatePHI(zero->getType(), 2, "arrayinit.index"); index->addIncoming(zero, entryBB); llvm::Value *element = Builder.CreateInBoundsGEP(begin, index); // Prepare for a cleanup. QualType::DestructionKind dtorKind = elementType.isDestructedType(); EHScopeStack::stable_iterator cleanup; if (CGF.needsEHCleanup(dtorKind) && !InnerLoop) { if (outerBegin->getType() != element->getType()) outerBegin = Builder.CreateBitCast(outerBegin, element->getType()); CGF.pushRegularPartialArrayCleanup(outerBegin, element, elementType, elementAlign, CGF.getDestroyer(dtorKind)); cleanup = CGF.EHStack.stable_begin(); } else { dtorKind = QualType::DK_none; } // Emit the actual filler expression. { // Temporaries created in an array initialization loop are destroyed // at the end of each iteration. CodeGenFunction::RunCleanupsScope CleanupsScope(CGF); CodeGenFunction::ArrayInitLoopExprScope Scope(CGF, index); LValue elementLV = CGF.MakeAddrLValue(Address(element, elementAlign), elementType); if (InnerLoop) { // If the subexpression is an ArrayInitLoopExpr, share its cleanup. auto elementSlot = AggValueSlot::forLValue( elementLV, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); AggExprEmitter(CGF, elementSlot, false) .VisitArrayInitLoopExpr(InnerLoop, outerBegin); } else EmitInitializationToLValue(E->getSubExpr(), elementLV); } // Move on to the next element. llvm::Value *nextIndex = Builder.CreateNUWAdd( index, llvm::ConstantInt::get(CGF.SizeTy, 1), "arrayinit.next"); index->addIncoming(nextIndex, Builder.GetInsertBlock()); // Leave the loop if we're done. llvm::Value *done = Builder.CreateICmpEQ( nextIndex, llvm::ConstantInt::get(CGF.SizeTy, numElements), "arrayinit.done"); llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end"); Builder.CreateCondBr(done, endBB, bodyBB); CGF.EmitBlock(endBB); // Leave the partial-array cleanup if we entered one. if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, index); } a1319 4 if (auto *CXXRD = dyn_cast(SD)) while (ILEElement != CXXRD->getNumBases()) NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(ILEElement++), CGF); @ 1.1.1.11 log @Import clang r309604 from branches/release_50 @ text @a113 7 void VisitCoawaitExpr(CoawaitExpr *E) { CGF.EmitCoawaitExpr(*E, Dest, IsResultUnused); } void VisitCoyieldExpr(CoyieldExpr *E) { CGF.EmitCoyieldExpr(*E, Dest, IsResultUnused); } void VisitUnaryCoawait(UnaryOperator *E) { Visit(E->getSubExpr()); } d508 6 a513 14 { // C++1z [class.temporary]p5: // when a default constructor is called to initialize an element of // an array with no corresponding initializer [...] the destruction of // every temporary created in a default argument is sequenced before // the construction of the next array element, if any CodeGenFunction::RunCleanupsScope CleanupsScope(CGF); LValue elementLV = CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType); if (filler) EmitInitializationToLValue(filler, elementLV); else EmitNullInitializationToLValue(elementLV); } d1270 1 a1270 1 // We're out of initializers; default-initialize to null @ 1.1.1.11.4.1 log @Sync with HEAD @ text @a14 1 #include "CGCXXABI.h" a16 1 #include "ConstantEmitter.h" a24 1 #include "llvm/IR/IntrinsicInst.h" d39 17 a64 9 // Calls `Fn` with a valid return value slot, potentially creating a temporary // to do so. If a temporary is created, an appropriate copy into `Dest` will // be emitted, as will lifetime markers. // // The given function should take a ReturnValueSlot, and return an RValue that // points to said slot. void withReturnValueSlot(const Expr *E, llvm::function_ref Fn); a78 5 enum ExprValueKind { EVK_RValue, EVK_NonRValue }; d80 1 a80 3 /// SrcIsRValue is true if source comes from an RValue. void EmitFinalDestCopy(QualType type, const LValue &src, ExprValueKind SrcValueKind = EVK_NonRValue); d88 1 a88 1 QualType ArrayQTy, InitListExpr *E); d127 18 a144 1 void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); } a163 1 void VisitBinCmp(const BinaryOperator *E); d237 1 a237 1 /// True if the given aggregate type requires special GC API calls. d254 16 a269 39 void AggExprEmitter::withReturnValueSlot( const Expr *E, llvm::function_ref EmitCall) { QualType RetTy = E->getType(); bool RequiresDestruction = Dest.isIgnored() && RetTy.isDestructedType() == QualType::DK_nontrivial_c_struct; // If it makes no observable difference, save a memcpy + temporary. // // We need to always provide our own temporary if destruction is required. // Otherwise, EmitCall will emit its own, notice that it's "unused", and end // its lifetime before we have the chance to emit a proper destructor call. bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() || (RequiresDestruction && !Dest.getAddress().isValid()); Address RetAddr = Address::invalid(); Address RetAllocaAddr = Address::invalid(); EHScopeStack::stable_iterator LifetimeEndBlock; llvm::Value *LifetimeSizePtr = nullptr; llvm::IntrinsicInst *LifetimeStartInst = nullptr; if (!UseTemp) { RetAddr = Dest.getAddress(); } else { RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr); uint64_t Size = CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy)); LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer()); if (LifetimeSizePtr) { LifetimeStartInst = cast(std::prev(Builder.GetInsertPoint())); assert(LifetimeStartInst->getIntrinsicID() == llvm::Intrinsic::lifetime_start && "Last insertion wasn't a lifetime.start?"); CGF.pushFullExprCleanup( NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr); LifetimeEndBlock = CGF.EHStack.stable_begin(); } d272 3 a274 19 RValue Src = EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused)); if (RequiresDestruction) CGF.pushDestroy(RetTy.isDestructedType(), Src.getAggregateAddress(), RetTy); if (!UseTemp) return; assert(Dest.getPointer() != Src.getAggregatePointer()); EmitFinalDestCopy(E->getType(), Src); if (!RequiresDestruction && LifetimeStartInst) { // If there's no dtor to run, the copy was the last use of our temporary. // Since we're not guaranteed to be in an ExprWithCleanups, clean up // eagerly. CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst); CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer()); } d281 1 a281 1 EmitFinalDestCopy(type, srcLV, EVK_RValue); d285 1 a285 2 void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src, ExprValueKind SrcValueKind) { a292 22 // Copy non-trivial C structs here. LValue DstLV = CGF.MakeAddrLValue( Dest.getAddress(), Dest.isVolatile() ? type.withVolatile() : type); if (SrcValueKind == EVK_RValue) { if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct) { if (Dest.isPotentiallyAliased()) CGF.callCStructMoveAssignmentOperator(DstLV, src); else CGF.callCStructMoveConstructor(DstLV, src); return; } } else { if (type.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) { if (Dest.isPotentiallyAliased()) CGF.callCStructCopyAssignmentOperator(DstLV, src); else CGF.callCStructCopyConstructor(DstLV, src); return; } } d295 1 a295 2 needsGC(type), AggValueSlot::IsAliased, AggValueSlot::MayOverlap); d306 1 a306 1 CharUnits sz = dest.getPreferredSize(CGF.getContext(), type); d318 1 a318 3 LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type); LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type); CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(), d322 1 a322 1 /// Emit the initializer for a std::initializer_list initialized with a d387 1 a387 1 /// Determine if E is a trivial array filler, that is, one that is d410 1 a410 1 /// Emit initialization of an array from an initializer list. d412 1 a412 1 QualType ArrayQTy, InitListExpr *E) { a417 3 QualType elementType = CGF.getContext().getAsArrayType(ArrayQTy)->getElementType(); a428 23 // Consider initializing the array by copying from a global. For this to be // more efficient than per-element initialization, the size of the elements // with explicit initializers should be large enough. if (NumInitElements * elementSize.getQuantity() > 16 && elementType.isTriviallyCopyableType(CGF.getContext())) { CodeGen::CodeGenModule &CGM = CGF.CGM; ConstantEmitter Emitter(CGM); LangAS AS = ArrayQTy.getAddressSpace(); if (llvm::Constant *C = Emitter.tryEmitForInitializer(E, AS, ArrayQTy)) { auto GV = new llvm::GlobalVariable( CGM.getModule(), C->getType(), CGM.isTypeConstant(ArrayQTy, /* ExcludeCtorDtor= */ true), llvm::GlobalValue::PrivateLinkage, C, "constinit", /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal, CGM.getContext().getTargetAddressSpace(AS)); Emitter.finalize(GV); CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy); GV->setAlignment(Align.getQuantity()); EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GV, ArrayQTy, Align)); return; } } d560 1 a560 5 // If this is a unique OVE, just visit its source expression. if (e->isUnique()) Visit(e->getSourceExpr()); else EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e)); d606 1 a606 1 d611 1 a611 1 d671 1 a671 1 // Zero-initialize. (Strictly speaking, we only need to initialize a684 1 AggValueSlot::DoesNotOverlap, d712 1 a712 1 LLVM_FALLTHROUGH; d782 2 a783 3 withReturnValueSlot(E, [&](ReturnValueSlot Slot) { return CGF.EmitCallExpr(E, Slot); }); d787 2 a788 3 withReturnValueSlot(E, [&](ReturnValueSlot Slot) { return CGF.EmitObjCMessageExpr(E, Slot); }); a800 144 enum CompareKind { CK_Less, CK_Greater, CK_Equal, }; static llvm::Value *EmitCompare(CGBuilderTy &Builder, CodeGenFunction &CGF, const BinaryOperator *E, llvm::Value *LHS, llvm::Value *RHS, CompareKind Kind, const char *NameSuffix = "") { QualType ArgTy = E->getLHS()->getType(); if (const ComplexType *CT = ArgTy->getAs()) ArgTy = CT->getElementType(); if (const auto *MPT = ArgTy->getAs()) { assert(Kind == CK_Equal && "member pointers may only be compared for equality"); return CGF.CGM.getCXXABI().EmitMemberPointerComparison( CGF, LHS, RHS, MPT, /*IsInequality*/ false); } // Compute the comparison instructions for the specified comparison kind. struct CmpInstInfo { const char *Name; llvm::CmpInst::Predicate FCmp; llvm::CmpInst::Predicate SCmp; llvm::CmpInst::Predicate UCmp; }; CmpInstInfo InstInfo = [&]() -> CmpInstInfo { using FI = llvm::FCmpInst; using II = llvm::ICmpInst; switch (Kind) { case CK_Less: return {"cmp.lt", FI::FCMP_OLT, II::ICMP_SLT, II::ICMP_ULT}; case CK_Greater: return {"cmp.gt", FI::FCMP_OGT, II::ICMP_SGT, II::ICMP_UGT}; case CK_Equal: return {"cmp.eq", FI::FCMP_OEQ, II::ICMP_EQ, II::ICMP_EQ}; } llvm_unreachable("Unrecognised CompareKind enum"); }(); if (ArgTy->hasFloatingRepresentation()) return Builder.CreateFCmp(InstInfo.FCmp, LHS, RHS, llvm::Twine(InstInfo.Name) + NameSuffix); if (ArgTy->isIntegralOrEnumerationType() || ArgTy->isPointerType()) { auto Inst = ArgTy->hasSignedIntegerRepresentation() ? InstInfo.SCmp : InstInfo.UCmp; return Builder.CreateICmp(Inst, LHS, RHS, llvm::Twine(InstInfo.Name) + NameSuffix); } llvm_unreachable("unsupported aggregate binary expression should have " "already been handled"); } void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) { using llvm::BasicBlock; using llvm::PHINode; using llvm::Value; assert(CGF.getContext().hasSameType(E->getLHS()->getType(), E->getRHS()->getType())); const ComparisonCategoryInfo &CmpInfo = CGF.getContext().CompCategories.getInfoForType(E->getType()); assert(CmpInfo.Record->isTriviallyCopyable() && "cannot copy non-trivially copyable aggregate"); QualType ArgTy = E->getLHS()->getType(); // TODO: Handle comparing these types. if (ArgTy->isVectorType()) return CGF.ErrorUnsupported( E, "aggregate three-way comparison with vector arguments"); if (!ArgTy->isIntegralOrEnumerationType() && !ArgTy->isRealFloatingType() && !ArgTy->isNullPtrType() && !ArgTy->isPointerType() && !ArgTy->isMemberPointerType() && !ArgTy->isAnyComplexType()) { return CGF.ErrorUnsupported(E, "aggregate three-way comparison"); } bool IsComplex = ArgTy->isAnyComplexType(); // Evaluate the operands to the expression and extract their values. auto EmitOperand = [&](Expr *E) -> std::pair { RValue RV = CGF.EmitAnyExpr(E); if (RV.isScalar()) return {RV.getScalarVal(), nullptr}; if (RV.isAggregate()) return {RV.getAggregatePointer(), nullptr}; assert(RV.isComplex()); return RV.getComplexVal(); }; auto LHSValues = EmitOperand(E->getLHS()), RHSValues = EmitOperand(E->getRHS()); auto EmitCmp = [&](CompareKind K) { Value *Cmp = EmitCompare(Builder, CGF, E, LHSValues.first, RHSValues.first, K, IsComplex ? ".r" : ""); if (!IsComplex) return Cmp; assert(K == CompareKind::CK_Equal); Value *CmpImag = EmitCompare(Builder, CGF, E, LHSValues.second, RHSValues.second, K, ".i"); return Builder.CreateAnd(Cmp, CmpImag, "and.eq"); }; auto EmitCmpRes = [&](const ComparisonCategoryInfo::ValueInfo *VInfo) { return Builder.getInt(VInfo->getIntValue()); }; Value *Select; if (ArgTy->isNullPtrType()) { Select = EmitCmpRes(CmpInfo.getEqualOrEquiv()); } else if (CmpInfo.isEquality()) { Select = Builder.CreateSelect( EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), EmitCmpRes(CmpInfo.getNonequalOrNonequiv()), "sel.eq"); } else if (!CmpInfo.isPartial()) { Value *SelectOne = Builder.CreateSelect(EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), EmitCmpRes(CmpInfo.getGreater()), "sel.lt"); Select = Builder.CreateSelect(EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), SelectOne, "sel.eq"); } else { Value *SelectEq = Builder.CreateSelect( EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), EmitCmpRes(CmpInfo.getUnordered()), "sel.eq"); Value *SelectGT = Builder.CreateSelect(EmitCmp(CK_Greater), EmitCmpRes(CmpInfo.getGreater()), SelectEq, "sel.gt"); Select = Builder.CreateSelect( EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), SelectGT, "sel.lt"); } // Create the return value in the destination slot. EnsureDest(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); // Emit the address of the first (and only) field in the comparison category // type, and initialize it from the constant integer value selected above. LValue FieldLV = CGF.EmitLValueForFieldInitialization( DestLV, *CmpInfo.Record->field_begin()); CGF.EmitStoreThroughLValue(RValue::get(Select), FieldLV, /*IsInit*/ true); // All done! The result is in the Dest slot. } d910 1 a910 2 AggValueSlot::IsAliased, AggValueSlot::MayOverlap), d931 1 a931 2 AggValueSlot::IsAliased, AggValueSlot::MayOverlap); a1108 1 AggValueSlot::MayOverlap, d1176 3 d1180 1 a1180 1 EmitArrayInit(Dest.getAddress(), AType, E->getType(), E); d1210 5 a1214 6 AggValueSlot AggSlot = AggValueSlot::forAddr( V, Qualifiers(), AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, CGF.overlapForBaseInit(CXXRD, BaseRD, Base.isVirtual())); d1395 1 a1395 3 AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap); a1444 2 while (ILE && ILE->isTransparent()) ILE = dyn_cast(ILE->getInit(0)); d1511 1 a1511 1 CharUnits Size = Slot.getPreferredSize(CGF.getContext(), E->getType()); d1557 1 a1557 2 AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap)); d1561 4 a1564 26 AggValueSlot::Overlap_t CodeGenFunction::overlapForBaseInit( const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual) { // Virtual bases are initialized first, in address order, so there's never // any overlap during their initialization. // // FIXME: Under P0840, this is no longer true: the tail padding of a vbase // of a field could be reused by a vbase of a containing class. if (IsVirtual) return AggValueSlot::DoesNotOverlap; // If the base class is laid out entirely within the nvsize of the derived // class, its tail padding cannot yet be initialized, so we can issue // stores at the full width of the base class. const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); if (Layout.getBaseClassOffset(BaseRD) + getContext().getASTRecordLayout(BaseRD).getSize() <= Layout.getNonVirtualSize()) return AggValueSlot::DoesNotOverlap; // The tail padding may contain values we need to preserve. return AggValueSlot::MayOverlap; } void CodeGenFunction::EmitAggregateCopy(LValue Dest, LValue Src, QualType Ty, AggValueSlot::Overlap_t MayOverlap, bool isVolatile) { a1566 3 Address DestPtr = Dest.getAddress(); Address SrcPtr = Src.getAddress(); d1582 1 a1582 1 d1594 4 a1597 3 // Get data size info for this aggregate. Don't copy the tail padding if this // might be a potentially-overlapping subobject, since the tail padding might // be occupied by a different object. Otherwise, copying it is fine. d1599 1 a1599 1 if (MayOverlap) d1611 4 a1614 1 TypeInfo = getContext().getTypeInfoInChars(BaseEltTy); d1619 8 a1676 6 if (CGM.getCodeGenOpts().NewStructPathTBAA) { TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForMemoryTransfer( Dest.getTBAAInfo(), Src.getTBAAInfo()); CGM.DecorateInstructionWithTBAA(Inst, TBAAInfo); } @ 1.1.1.11.4.2 log @Mostly merge changes from HEAD upto 20200411 @ text @@ 1.1.1.11.2.1 log @Sync with HEAD @ text @a14 1 #include "CGCXXABI.h" a16 1 #include "ConstantEmitter.h" a24 1 #include "llvm/IR/IntrinsicInst.h" d39 17 a64 9 // Calls `Fn` with a valid return value slot, potentially creating a temporary // to do so. If a temporary is created, an appropriate copy into `Dest` will // be emitted, as will lifetime markers. // // The given function should take a ReturnValueSlot, and return an RValue that // points to said slot. void withReturnValueSlot(const Expr *E, llvm::function_ref Fn); a78 5 enum ExprValueKind { EVK_RValue, EVK_NonRValue }; d80 1 a80 3 /// SrcIsRValue is true if source comes from an RValue. void EmitFinalDestCopy(QualType type, const LValue &src, ExprValueKind SrcValueKind = EVK_NonRValue); d88 1 a88 1 QualType ArrayQTy, InitListExpr *E); d127 18 a144 1 void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); } a163 1 void VisitBinCmp(const BinaryOperator *E); d237 1 a237 1 /// True if the given aggregate type requires special GC API calls. d254 16 a269 39 void AggExprEmitter::withReturnValueSlot( const Expr *E, llvm::function_ref EmitCall) { QualType RetTy = E->getType(); bool RequiresDestruction = Dest.isIgnored() && RetTy.isDestructedType() == QualType::DK_nontrivial_c_struct; // If it makes no observable difference, save a memcpy + temporary. // // We need to always provide our own temporary if destruction is required. // Otherwise, EmitCall will emit its own, notice that it's "unused", and end // its lifetime before we have the chance to emit a proper destructor call. bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() || (RequiresDestruction && !Dest.getAddress().isValid()); Address RetAddr = Address::invalid(); Address RetAllocaAddr = Address::invalid(); EHScopeStack::stable_iterator LifetimeEndBlock; llvm::Value *LifetimeSizePtr = nullptr; llvm::IntrinsicInst *LifetimeStartInst = nullptr; if (!UseTemp) { RetAddr = Dest.getAddress(); } else { RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr); uint64_t Size = CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy)); LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer()); if (LifetimeSizePtr) { LifetimeStartInst = cast(std::prev(Builder.GetInsertPoint())); assert(LifetimeStartInst->getIntrinsicID() == llvm::Intrinsic::lifetime_start && "Last insertion wasn't a lifetime.start?"); CGF.pushFullExprCleanup( NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr); LifetimeEndBlock = CGF.EHStack.stable_begin(); } d272 3 a274 19 RValue Src = EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused)); if (RequiresDestruction) CGF.pushDestroy(RetTy.isDestructedType(), Src.getAggregateAddress(), RetTy); if (!UseTemp) return; assert(Dest.getPointer() != Src.getAggregatePointer()); EmitFinalDestCopy(E->getType(), Src); if (!RequiresDestruction && LifetimeStartInst) { // If there's no dtor to run, the copy was the last use of our temporary. // Since we're not guaranteed to be in an ExprWithCleanups, clean up // eagerly. CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst); CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer()); } d281 1 a281 1 EmitFinalDestCopy(type, srcLV, EVK_RValue); d285 1 a285 2 void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src, ExprValueKind SrcValueKind) { a292 22 // Copy non-trivial C structs here. LValue DstLV = CGF.MakeAddrLValue( Dest.getAddress(), Dest.isVolatile() ? type.withVolatile() : type); if (SrcValueKind == EVK_RValue) { if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct) { if (Dest.isPotentiallyAliased()) CGF.callCStructMoveAssignmentOperator(DstLV, src); else CGF.callCStructMoveConstructor(DstLV, src); return; } } else { if (type.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) { if (Dest.isPotentiallyAliased()) CGF.callCStructCopyAssignmentOperator(DstLV, src); else CGF.callCStructCopyConstructor(DstLV, src); return; } } d295 1 a295 2 needsGC(type), AggValueSlot::IsAliased, AggValueSlot::MayOverlap); d306 1 a306 1 CharUnits sz = dest.getPreferredSize(CGF.getContext(), type); d318 1 a318 3 LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type); LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type); CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(), d322 1 a322 1 /// Emit the initializer for a std::initializer_list initialized with a d387 1 a387 1 /// Determine if E is a trivial array filler, that is, one that is d410 1 a410 1 /// Emit initialization of an array from an initializer list. d412 1 a412 1 QualType ArrayQTy, InitListExpr *E) { a417 3 QualType elementType = CGF.getContext().getAsArrayType(ArrayQTy)->getElementType(); a428 23 // Consider initializing the array by copying from a global. For this to be // more efficient than per-element initialization, the size of the elements // with explicit initializers should be large enough. if (NumInitElements * elementSize.getQuantity() > 16 && elementType.isTriviallyCopyableType(CGF.getContext())) { CodeGen::CodeGenModule &CGM = CGF.CGM; ConstantEmitter Emitter(CGM); LangAS AS = ArrayQTy.getAddressSpace(); if (llvm::Constant *C = Emitter.tryEmitForInitializer(E, AS, ArrayQTy)) { auto GV = new llvm::GlobalVariable( CGM.getModule(), C->getType(), CGM.isTypeConstant(ArrayQTy, /* ExcludeCtorDtor= */ true), llvm::GlobalValue::PrivateLinkage, C, "constinit", /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal, CGM.getContext().getTargetAddressSpace(AS)); Emitter.finalize(GV); CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy); GV->setAlignment(Align.getQuantity()); EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GV, ArrayQTy, Align)); return; } } d560 1 a560 5 // If this is a unique OVE, just visit its source expression. if (e->isUnique()) Visit(e->getSourceExpr()); else EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e)); d606 1 a606 1 d611 1 a611 1 d671 1 a671 1 // Zero-initialize. (Strictly speaking, we only need to initialize a684 1 AggValueSlot::DoesNotOverlap, d712 1 a712 1 LLVM_FALLTHROUGH; d782 2 a783 3 withReturnValueSlot(E, [&](ReturnValueSlot Slot) { return CGF.EmitCallExpr(E, Slot); }); d787 2 a788 3 withReturnValueSlot(E, [&](ReturnValueSlot Slot) { return CGF.EmitObjCMessageExpr(E, Slot); }); a800 144 enum CompareKind { CK_Less, CK_Greater, CK_Equal, }; static llvm::Value *EmitCompare(CGBuilderTy &Builder, CodeGenFunction &CGF, const BinaryOperator *E, llvm::Value *LHS, llvm::Value *RHS, CompareKind Kind, const char *NameSuffix = "") { QualType ArgTy = E->getLHS()->getType(); if (const ComplexType *CT = ArgTy->getAs()) ArgTy = CT->getElementType(); if (const auto *MPT = ArgTy->getAs()) { assert(Kind == CK_Equal && "member pointers may only be compared for equality"); return CGF.CGM.getCXXABI().EmitMemberPointerComparison( CGF, LHS, RHS, MPT, /*IsInequality*/ false); } // Compute the comparison instructions for the specified comparison kind. struct CmpInstInfo { const char *Name; llvm::CmpInst::Predicate FCmp; llvm::CmpInst::Predicate SCmp; llvm::CmpInst::Predicate UCmp; }; CmpInstInfo InstInfo = [&]() -> CmpInstInfo { using FI = llvm::FCmpInst; using II = llvm::ICmpInst; switch (Kind) { case CK_Less: return {"cmp.lt", FI::FCMP_OLT, II::ICMP_SLT, II::ICMP_ULT}; case CK_Greater: return {"cmp.gt", FI::FCMP_OGT, II::ICMP_SGT, II::ICMP_UGT}; case CK_Equal: return {"cmp.eq", FI::FCMP_OEQ, II::ICMP_EQ, II::ICMP_EQ}; } llvm_unreachable("Unrecognised CompareKind enum"); }(); if (ArgTy->hasFloatingRepresentation()) return Builder.CreateFCmp(InstInfo.FCmp, LHS, RHS, llvm::Twine(InstInfo.Name) + NameSuffix); if (ArgTy->isIntegralOrEnumerationType() || ArgTy->isPointerType()) { auto Inst = ArgTy->hasSignedIntegerRepresentation() ? InstInfo.SCmp : InstInfo.UCmp; return Builder.CreateICmp(Inst, LHS, RHS, llvm::Twine(InstInfo.Name) + NameSuffix); } llvm_unreachable("unsupported aggregate binary expression should have " "already been handled"); } void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) { using llvm::BasicBlock; using llvm::PHINode; using llvm::Value; assert(CGF.getContext().hasSameType(E->getLHS()->getType(), E->getRHS()->getType())); const ComparisonCategoryInfo &CmpInfo = CGF.getContext().CompCategories.getInfoForType(E->getType()); assert(CmpInfo.Record->isTriviallyCopyable() && "cannot copy non-trivially copyable aggregate"); QualType ArgTy = E->getLHS()->getType(); // TODO: Handle comparing these types. if (ArgTy->isVectorType()) return CGF.ErrorUnsupported( E, "aggregate three-way comparison with vector arguments"); if (!ArgTy->isIntegralOrEnumerationType() && !ArgTy->isRealFloatingType() && !ArgTy->isNullPtrType() && !ArgTy->isPointerType() && !ArgTy->isMemberPointerType() && !ArgTy->isAnyComplexType()) { return CGF.ErrorUnsupported(E, "aggregate three-way comparison"); } bool IsComplex = ArgTy->isAnyComplexType(); // Evaluate the operands to the expression and extract their values. auto EmitOperand = [&](Expr *E) -> std::pair { RValue RV = CGF.EmitAnyExpr(E); if (RV.isScalar()) return {RV.getScalarVal(), nullptr}; if (RV.isAggregate()) return {RV.getAggregatePointer(), nullptr}; assert(RV.isComplex()); return RV.getComplexVal(); }; auto LHSValues = EmitOperand(E->getLHS()), RHSValues = EmitOperand(E->getRHS()); auto EmitCmp = [&](CompareKind K) { Value *Cmp = EmitCompare(Builder, CGF, E, LHSValues.first, RHSValues.first, K, IsComplex ? ".r" : ""); if (!IsComplex) return Cmp; assert(K == CompareKind::CK_Equal); Value *CmpImag = EmitCompare(Builder, CGF, E, LHSValues.second, RHSValues.second, K, ".i"); return Builder.CreateAnd(Cmp, CmpImag, "and.eq"); }; auto EmitCmpRes = [&](const ComparisonCategoryInfo::ValueInfo *VInfo) { return Builder.getInt(VInfo->getIntValue()); }; Value *Select; if (ArgTy->isNullPtrType()) { Select = EmitCmpRes(CmpInfo.getEqualOrEquiv()); } else if (CmpInfo.isEquality()) { Select = Builder.CreateSelect( EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), EmitCmpRes(CmpInfo.getNonequalOrNonequiv()), "sel.eq"); } else if (!CmpInfo.isPartial()) { Value *SelectOne = Builder.CreateSelect(EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), EmitCmpRes(CmpInfo.getGreater()), "sel.lt"); Select = Builder.CreateSelect(EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), SelectOne, "sel.eq"); } else { Value *SelectEq = Builder.CreateSelect( EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), EmitCmpRes(CmpInfo.getUnordered()), "sel.eq"); Value *SelectGT = Builder.CreateSelect(EmitCmp(CK_Greater), EmitCmpRes(CmpInfo.getGreater()), SelectEq, "sel.gt"); Select = Builder.CreateSelect( EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), SelectGT, "sel.lt"); } // Create the return value in the destination slot. EnsureDest(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); // Emit the address of the first (and only) field in the comparison category // type, and initialize it from the constant integer value selected above. LValue FieldLV = CGF.EmitLValueForFieldInitialization( DestLV, *CmpInfo.Record->field_begin()); CGF.EmitStoreThroughLValue(RValue::get(Select), FieldLV, /*IsInit*/ true); // All done! The result is in the Dest slot. } d910 1 a910 2 AggValueSlot::IsAliased, AggValueSlot::MayOverlap), d931 1 a931 2 AggValueSlot::IsAliased, AggValueSlot::MayOverlap); a1108 1 AggValueSlot::MayOverlap, d1176 3 d1180 1 a1180 1 EmitArrayInit(Dest.getAddress(), AType, E->getType(), E); d1210 5 a1214 6 AggValueSlot AggSlot = AggValueSlot::forAddr( V, Qualifiers(), AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, CGF.overlapForBaseInit(CXXRD, BaseRD, Base.isVirtual())); d1395 1 a1395 3 AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap); a1444 2 while (ILE && ILE->isTransparent()) ILE = dyn_cast(ILE->getInit(0)); d1511 1 a1511 1 CharUnits Size = Slot.getPreferredSize(CGF.getContext(), E->getType()); d1557 1 a1557 2 AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap)); d1561 4 a1564 26 AggValueSlot::Overlap_t CodeGenFunction::overlapForBaseInit( const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual) { // Virtual bases are initialized first, in address order, so there's never // any overlap during their initialization. // // FIXME: Under P0840, this is no longer true: the tail padding of a vbase // of a field could be reused by a vbase of a containing class. if (IsVirtual) return AggValueSlot::DoesNotOverlap; // If the base class is laid out entirely within the nvsize of the derived // class, its tail padding cannot yet be initialized, so we can issue // stores at the full width of the base class. const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); if (Layout.getBaseClassOffset(BaseRD) + getContext().getASTRecordLayout(BaseRD).getSize() <= Layout.getNonVirtualSize()) return AggValueSlot::DoesNotOverlap; // The tail padding may contain values we need to preserve. return AggValueSlot::MayOverlap; } void CodeGenFunction::EmitAggregateCopy(LValue Dest, LValue Src, QualType Ty, AggValueSlot::Overlap_t MayOverlap, bool isVolatile) { a1566 3 Address DestPtr = Dest.getAddress(); Address SrcPtr = Src.getAddress(); d1582 1 a1582 1 d1594 4 a1597 3 // Get data size info for this aggregate. Don't copy the tail padding if this // might be a potentially-overlapping subobject, since the tail padding might // be occupied by a different object. Otherwise, copying it is fine. d1599 1 a1599 1 if (MayOverlap) d1611 4 a1614 1 TypeInfo = getContext().getTypeInfoInChars(BaseEltTy); d1619 8 a1676 6 if (CGM.getCodeGenOpts().NewStructPathTBAA) { TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForMemoryTransfer( Dest.getTBAAInfo(), Src.getTBAAInfo()); CGM.DecorateInstructionWithTBAA(Inst, TBAAInfo); } @ 1.1.1.12 log @Import clang r337282 from trunk @ text @a14 1 #include "CGCXXABI.h" a16 1 #include "ConstantEmitter.h" a24 1 #include "llvm/IR/IntrinsicInst.h" d39 17 a64 9 // Calls `Fn` with a valid return value slot, potentially creating a temporary // to do so. If a temporary is created, an appropriate copy into `Dest` will // be emitted, as will lifetime markers. // // The given function should take a ReturnValueSlot, and return an RValue that // points to said slot. void withReturnValueSlot(const Expr *E, llvm::function_ref Fn); a78 5 enum ExprValueKind { EVK_RValue, EVK_NonRValue }; d80 1 a80 3 /// SrcIsRValue is true if source comes from an RValue. void EmitFinalDestCopy(QualType type, const LValue &src, ExprValueKind SrcValueKind = EVK_NonRValue); d88 1 a88 1 QualType ArrayQTy, InitListExpr *E); d127 18 a144 1 void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); } a163 1 void VisitBinCmp(const BinaryOperator *E); d237 1 a237 1 /// True if the given aggregate type requires special GC API calls. d254 16 a269 39 void AggExprEmitter::withReturnValueSlot( const Expr *E, llvm::function_ref EmitCall) { QualType RetTy = E->getType(); bool RequiresDestruction = Dest.isIgnored() && RetTy.isDestructedType() == QualType::DK_nontrivial_c_struct; // If it makes no observable difference, save a memcpy + temporary. // // We need to always provide our own temporary if destruction is required. // Otherwise, EmitCall will emit its own, notice that it's "unused", and end // its lifetime before we have the chance to emit a proper destructor call. bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() || (RequiresDestruction && !Dest.getAddress().isValid()); Address RetAddr = Address::invalid(); Address RetAllocaAddr = Address::invalid(); EHScopeStack::stable_iterator LifetimeEndBlock; llvm::Value *LifetimeSizePtr = nullptr; llvm::IntrinsicInst *LifetimeStartInst = nullptr; if (!UseTemp) { RetAddr = Dest.getAddress(); } else { RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr); uint64_t Size = CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy)); LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer()); if (LifetimeSizePtr) { LifetimeStartInst = cast(std::prev(Builder.GetInsertPoint())); assert(LifetimeStartInst->getIntrinsicID() == llvm::Intrinsic::lifetime_start && "Last insertion wasn't a lifetime.start?"); CGF.pushFullExprCleanup( NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr); LifetimeEndBlock = CGF.EHStack.stable_begin(); } d272 3 a274 19 RValue Src = EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused)); if (RequiresDestruction) CGF.pushDestroy(RetTy.isDestructedType(), Src.getAggregateAddress(), RetTy); if (!UseTemp) return; assert(Dest.getPointer() != Src.getAggregatePointer()); EmitFinalDestCopy(E->getType(), Src); if (!RequiresDestruction && LifetimeStartInst) { // If there's no dtor to run, the copy was the last use of our temporary. // Since we're not guaranteed to be in an ExprWithCleanups, clean up // eagerly. CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst); CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer()); } d281 1 a281 1 EmitFinalDestCopy(type, srcLV, EVK_RValue); d285 1 a285 2 void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src, ExprValueKind SrcValueKind) { a292 22 // Copy non-trivial C structs here. LValue DstLV = CGF.MakeAddrLValue( Dest.getAddress(), Dest.isVolatile() ? type.withVolatile() : type); if (SrcValueKind == EVK_RValue) { if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct) { if (Dest.isPotentiallyAliased()) CGF.callCStructMoveAssignmentOperator(DstLV, src); else CGF.callCStructMoveConstructor(DstLV, src); return; } } else { if (type.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) { if (Dest.isPotentiallyAliased()) CGF.callCStructCopyAssignmentOperator(DstLV, src); else CGF.callCStructCopyConstructor(DstLV, src); return; } } d295 1 a295 2 needsGC(type), AggValueSlot::IsAliased, AggValueSlot::MayOverlap); d306 1 a306 1 CharUnits sz = dest.getPreferredSize(CGF.getContext(), type); d318 1 a318 3 LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type); LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type); CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(), d322 1 a322 1 /// Emit the initializer for a std::initializer_list initialized with a d387 1 a387 1 /// Determine if E is a trivial array filler, that is, one that is d410 1 a410 1 /// Emit initialization of an array from an initializer list. d412 1 a412 1 QualType ArrayQTy, InitListExpr *E) { a417 3 QualType elementType = CGF.getContext().getAsArrayType(ArrayQTy)->getElementType(); a428 23 // Consider initializing the array by copying from a global. For this to be // more efficient than per-element initialization, the size of the elements // with explicit initializers should be large enough. if (NumInitElements * elementSize.getQuantity() > 16 && elementType.isTriviallyCopyableType(CGF.getContext())) { CodeGen::CodeGenModule &CGM = CGF.CGM; ConstantEmitter Emitter(CGM); LangAS AS = ArrayQTy.getAddressSpace(); if (llvm::Constant *C = Emitter.tryEmitForInitializer(E, AS, ArrayQTy)) { auto GV = new llvm::GlobalVariable( CGM.getModule(), C->getType(), CGM.isTypeConstant(ArrayQTy, /* ExcludeCtorDtor= */ true), llvm::GlobalValue::PrivateLinkage, C, "constinit", /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal, CGM.getContext().getTargetAddressSpace(AS)); Emitter.finalize(GV); CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy); GV->setAlignment(Align.getQuantity()); EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GV, ArrayQTy, Align)); return; } } d560 1 a560 5 // If this is a unique OVE, just visit its source expression. if (e->isUnique()) Visit(e->getSourceExpr()); else EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e)); d606 1 a606 1 d611 1 a611 1 d671 1 a671 1 // Zero-initialize. (Strictly speaking, we only need to initialize a684 1 AggValueSlot::DoesNotOverlap, d712 1 a712 1 LLVM_FALLTHROUGH; d782 2 a783 3 withReturnValueSlot(E, [&](ReturnValueSlot Slot) { return CGF.EmitCallExpr(E, Slot); }); d787 2 a788 3 withReturnValueSlot(E, [&](ReturnValueSlot Slot) { return CGF.EmitObjCMessageExpr(E, Slot); }); a800 144 enum CompareKind { CK_Less, CK_Greater, CK_Equal, }; static llvm::Value *EmitCompare(CGBuilderTy &Builder, CodeGenFunction &CGF, const BinaryOperator *E, llvm::Value *LHS, llvm::Value *RHS, CompareKind Kind, const char *NameSuffix = "") { QualType ArgTy = E->getLHS()->getType(); if (const ComplexType *CT = ArgTy->getAs()) ArgTy = CT->getElementType(); if (const auto *MPT = ArgTy->getAs()) { assert(Kind == CK_Equal && "member pointers may only be compared for equality"); return CGF.CGM.getCXXABI().EmitMemberPointerComparison( CGF, LHS, RHS, MPT, /*IsInequality*/ false); } // Compute the comparison instructions for the specified comparison kind. struct CmpInstInfo { const char *Name; llvm::CmpInst::Predicate FCmp; llvm::CmpInst::Predicate SCmp; llvm::CmpInst::Predicate UCmp; }; CmpInstInfo InstInfo = [&]() -> CmpInstInfo { using FI = llvm::FCmpInst; using II = llvm::ICmpInst; switch (Kind) { case CK_Less: return {"cmp.lt", FI::FCMP_OLT, II::ICMP_SLT, II::ICMP_ULT}; case CK_Greater: return {"cmp.gt", FI::FCMP_OGT, II::ICMP_SGT, II::ICMP_UGT}; case CK_Equal: return {"cmp.eq", FI::FCMP_OEQ, II::ICMP_EQ, II::ICMP_EQ}; } llvm_unreachable("Unrecognised CompareKind enum"); }(); if (ArgTy->hasFloatingRepresentation()) return Builder.CreateFCmp(InstInfo.FCmp, LHS, RHS, llvm::Twine(InstInfo.Name) + NameSuffix); if (ArgTy->isIntegralOrEnumerationType() || ArgTy->isPointerType()) { auto Inst = ArgTy->hasSignedIntegerRepresentation() ? InstInfo.SCmp : InstInfo.UCmp; return Builder.CreateICmp(Inst, LHS, RHS, llvm::Twine(InstInfo.Name) + NameSuffix); } llvm_unreachable("unsupported aggregate binary expression should have " "already been handled"); } void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) { using llvm::BasicBlock; using llvm::PHINode; using llvm::Value; assert(CGF.getContext().hasSameType(E->getLHS()->getType(), E->getRHS()->getType())); const ComparisonCategoryInfo &CmpInfo = CGF.getContext().CompCategories.getInfoForType(E->getType()); assert(CmpInfo.Record->isTriviallyCopyable() && "cannot copy non-trivially copyable aggregate"); QualType ArgTy = E->getLHS()->getType(); // TODO: Handle comparing these types. if (ArgTy->isVectorType()) return CGF.ErrorUnsupported( E, "aggregate three-way comparison with vector arguments"); if (!ArgTy->isIntegralOrEnumerationType() && !ArgTy->isRealFloatingType() && !ArgTy->isNullPtrType() && !ArgTy->isPointerType() && !ArgTy->isMemberPointerType() && !ArgTy->isAnyComplexType()) { return CGF.ErrorUnsupported(E, "aggregate three-way comparison"); } bool IsComplex = ArgTy->isAnyComplexType(); // Evaluate the operands to the expression and extract their values. auto EmitOperand = [&](Expr *E) -> std::pair { RValue RV = CGF.EmitAnyExpr(E); if (RV.isScalar()) return {RV.getScalarVal(), nullptr}; if (RV.isAggregate()) return {RV.getAggregatePointer(), nullptr}; assert(RV.isComplex()); return RV.getComplexVal(); }; auto LHSValues = EmitOperand(E->getLHS()), RHSValues = EmitOperand(E->getRHS()); auto EmitCmp = [&](CompareKind K) { Value *Cmp = EmitCompare(Builder, CGF, E, LHSValues.first, RHSValues.first, K, IsComplex ? ".r" : ""); if (!IsComplex) return Cmp; assert(K == CompareKind::CK_Equal); Value *CmpImag = EmitCompare(Builder, CGF, E, LHSValues.second, RHSValues.second, K, ".i"); return Builder.CreateAnd(Cmp, CmpImag, "and.eq"); }; auto EmitCmpRes = [&](const ComparisonCategoryInfo::ValueInfo *VInfo) { return Builder.getInt(VInfo->getIntValue()); }; Value *Select; if (ArgTy->isNullPtrType()) { Select = EmitCmpRes(CmpInfo.getEqualOrEquiv()); } else if (CmpInfo.isEquality()) { Select = Builder.CreateSelect( EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), EmitCmpRes(CmpInfo.getNonequalOrNonequiv()), "sel.eq"); } else if (!CmpInfo.isPartial()) { Value *SelectOne = Builder.CreateSelect(EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), EmitCmpRes(CmpInfo.getGreater()), "sel.lt"); Select = Builder.CreateSelect(EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), SelectOne, "sel.eq"); } else { Value *SelectEq = Builder.CreateSelect( EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()), EmitCmpRes(CmpInfo.getUnordered()), "sel.eq"); Value *SelectGT = Builder.CreateSelect(EmitCmp(CK_Greater), EmitCmpRes(CmpInfo.getGreater()), SelectEq, "sel.gt"); Select = Builder.CreateSelect( EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), SelectGT, "sel.lt"); } // Create the return value in the destination slot. EnsureDest(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); // Emit the address of the first (and only) field in the comparison category // type, and initialize it from the constant integer value selected above. LValue FieldLV = CGF.EmitLValueForFieldInitialization( DestLV, *CmpInfo.Record->field_begin()); CGF.EmitStoreThroughLValue(RValue::get(Select), FieldLV, /*IsInit*/ true); // All done! The result is in the Dest slot. } d910 1 a910 2 AggValueSlot::IsAliased, AggValueSlot::MayOverlap), d931 1 a931 2 AggValueSlot::IsAliased, AggValueSlot::MayOverlap); a1108 1 AggValueSlot::MayOverlap, d1176 3 d1180 1 a1180 1 EmitArrayInit(Dest.getAddress(), AType, E->getType(), E); d1210 5 a1214 6 AggValueSlot AggSlot = AggValueSlot::forAddr( V, Qualifiers(), AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, CGF.overlapForBaseInit(CXXRD, BaseRD, Base.isVirtual())); d1395 1 a1395 3 AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap); a1444 2 while (ILE && ILE->isTransparent()) ILE = dyn_cast(ILE->getInit(0)); d1511 1 a1511 1 CharUnits Size = Slot.getPreferredSize(CGF.getContext(), E->getType()); d1557 1 a1557 2 AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap)); d1561 4 a1564 26 AggValueSlot::Overlap_t CodeGenFunction::overlapForBaseInit( const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual) { // Virtual bases are initialized first, in address order, so there's never // any overlap during their initialization. // // FIXME: Under P0840, this is no longer true: the tail padding of a vbase // of a field could be reused by a vbase of a containing class. if (IsVirtual) return AggValueSlot::DoesNotOverlap; // If the base class is laid out entirely within the nvsize of the derived // class, its tail padding cannot yet be initialized, so we can issue // stores at the full width of the base class. const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); if (Layout.getBaseClassOffset(BaseRD) + getContext().getASTRecordLayout(BaseRD).getSize() <= Layout.getNonVirtualSize()) return AggValueSlot::DoesNotOverlap; // The tail padding may contain values we need to preserve. return AggValueSlot::MayOverlap; } void CodeGenFunction::EmitAggregateCopy(LValue Dest, LValue Src, QualType Ty, AggValueSlot::Overlap_t MayOverlap, bool isVolatile) { a1566 3 Address DestPtr = Dest.getAddress(); Address SrcPtr = Src.getAddress(); d1582 1 a1582 1 d1594 4 a1597 3 // Get data size info for this aggregate. Don't copy the tail padding if this // might be a potentially-overlapping subobject, since the tail padding might // be occupied by a different object. Otherwise, copying it is fine. d1599 1 a1599 1 if (MayOverlap) d1611 4 a1614 1 TypeInfo = getContext().getTypeInfoInChars(BaseEltTy); d1619 8 a1676 6 if (CGM.getCodeGenOpts().NewStructPathTBAA) { TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForMemoryTransfer( Dest.getTBAAInfo(), Src.getTBAAInfo()); CGM.DecorateInstructionWithTBAA(Inst, TBAAInfo); } @ 1.1.1.13 log @Mark old LLVM instance as dead. @ text @@ 1.1.1.7.4.1 log @file CGExprAgg.cpp was added on branch tls-maxphys on 2014-08-19 23:47:27 +0000 @ text @d1 1505 @ 1.1.1.7.4.2 log @Rebase to HEAD as of a few days ago. @ text @a0 1505 //===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This contains code to emit Aggregate Expr nodes as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CGObjCRuntime.h" #include "CodeGenModule.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/StmtVisitor.h" #include "llvm/IR/Constants.h" #include "llvm/IR/Function.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Intrinsics.h" using namespace clang; using namespace CodeGen; //===----------------------------------------------------------------------===// // Aggregate Expression Emitter //===----------------------------------------------------------------------===// namespace { class AggExprEmitter : public StmtVisitor { CodeGenFunction &CGF; CGBuilderTy &Builder; AggValueSlot Dest; /// We want to use 'dest' as the return slot except under two /// conditions: /// - The destination slot requires garbage collection, so we /// need to use the GC API. /// - The destination slot is potentially aliased. bool shouldUseDestForReturnSlot() const { return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased()); } ReturnValueSlot getReturnValueSlot() const { if (!shouldUseDestForReturnSlot()) return ReturnValueSlot(); return ReturnValueSlot(Dest.getAddr(), Dest.isVolatile()); } AggValueSlot EnsureSlot(QualType T) { if (!Dest.isIgnored()) return Dest; return CGF.CreateAggTemp(T, "agg.tmp.ensured"); } void EnsureDest(QualType T) { if (!Dest.isIgnored()) return; Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured"); } public: AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest) : CGF(cgf), Builder(CGF.Builder), Dest(Dest) { } //===--------------------------------------------------------------------===// // Utilities //===--------------------------------------------------------------------===// /// EmitAggLoadOfLValue - Given an expression with aggregate type that /// represents a value lvalue, this method emits the address of the lvalue, /// then loads the result into DestPtr. void EmitAggLoadOfLValue(const Expr *E); /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void EmitFinalDestCopy(QualType type, const LValue &src); void EmitFinalDestCopy(QualType type, RValue src, CharUnits srcAlignment = CharUnits::Zero()); void EmitCopy(QualType type, const AggValueSlot &dest, const AggValueSlot &src); void EmitMoveFromReturnSlot(const Expr *E, RValue Src); void EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType, QualType elementType, InitListExpr *E); AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) { if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T)) return AggValueSlot::NeedsGCBarriers; return AggValueSlot::DoesNotNeedGCBarriers; } bool TypeRequiresGCollection(QualType T); //===--------------------------------------------------------------------===// // Visitor Methods //===--------------------------------------------------------------------===// void VisitStmt(Stmt *S) { CGF.ErrorUnsupported(S, "aggregate expression"); } void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); } void VisitGenericSelectionExpr(GenericSelectionExpr *GE) { Visit(GE->getResultExpr()); } void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); } void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { return Visit(E->getReplacement()); } // l-values. void VisitDeclRefExpr(DeclRefExpr *E) { // For aggregates, we should always be able to emit the variable // as an l-value unless it's a reference. This is due to the fact // that we can't actually ever see a normal l2r conversion on an // aggregate in C++, and in C there's no language standard // actively preventing us from listing variables in the captures // list of a block. if (E->getDecl()->getType()->isReferenceType()) { if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { EmitFinalDestCopy(E->getType(), result.getReferenceLValue(CGF, E)); return; } } EmitAggLoadOfLValue(E); } void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); } void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); } void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); } void VisitCompoundLiteralExpr(CompoundLiteralExpr *E); void VisitArraySubscriptExpr(ArraySubscriptExpr *E) { EmitAggLoadOfLValue(E); } void VisitPredefinedExpr(const PredefinedExpr *E) { EmitAggLoadOfLValue(E); } // Operators. void VisitCastExpr(CastExpr *E); void VisitCallExpr(const CallExpr *E); void VisitStmtExpr(const StmtExpr *E); void VisitBinaryOperator(const BinaryOperator *BO); void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO); void VisitBinAssign(const BinaryOperator *E); void VisitBinComma(const BinaryOperator *E); void VisitObjCMessageExpr(ObjCMessageExpr *E); void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { EmitAggLoadOfLValue(E); } void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO); void VisitChooseExpr(const ChooseExpr *CE); void VisitInitListExpr(InitListExpr *E); void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E); void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { Visit(DAE->getExpr()); } void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { CodeGenFunction::CXXDefaultInitExprScope Scope(CGF); Visit(DIE->getExpr()); } void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E); void VisitCXXConstructExpr(const CXXConstructExpr *E); void VisitLambdaExpr(LambdaExpr *E); void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E); void VisitExprWithCleanups(ExprWithCleanups *E); void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E); void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); } void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E); void VisitOpaqueValueExpr(OpaqueValueExpr *E); void VisitPseudoObjectExpr(PseudoObjectExpr *E) { if (E->isGLValue()) { LValue LV = CGF.EmitPseudoObjectLValue(E); return EmitFinalDestCopy(E->getType(), LV); } CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType())); } void VisitVAArgExpr(VAArgExpr *E); void EmitInitializationToLValue(Expr *E, LValue Address); void EmitNullInitializationToLValue(LValue Address); // case Expr::ChooseExprClass: void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); } void VisitAtomicExpr(AtomicExpr *E) { CGF.EmitAtomicExpr(E, EnsureSlot(E->getType()).getAddr()); } }; } // end anonymous namespace. //===----------------------------------------------------------------------===// // Utilities //===----------------------------------------------------------------------===// /// EmitAggLoadOfLValue - Given an expression with aggregate type that /// represents a value lvalue, this method emits the address of the lvalue, /// then loads the result into DestPtr. void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) { LValue LV = CGF.EmitLValue(E); // If the type of the l-value is atomic, then do an atomic load. if (LV.getType()->isAtomicType()) { CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest); return; } EmitFinalDestCopy(E->getType(), LV); } /// \brief True if the given aggregate type requires special GC API calls. bool AggExprEmitter::TypeRequiresGCollection(QualType T) { // Only record types have members that might require garbage collection. const RecordType *RecordTy = T->getAs(); if (!RecordTy) return false; // Don't mess with non-trivial C++ types. RecordDecl *Record = RecordTy->getDecl(); if (isa(Record) && (cast(Record)->hasNonTrivialCopyConstructor() || !cast(Record)->hasTrivialDestructor())) return false; // Check whether the type has an object member. return Record->hasObjectMember(); } /// \brief Perform the final move to DestPtr if for some reason /// getReturnValueSlot() didn't use it directly. /// /// The idea is that you do something like this: /// RValue Result = EmitSomething(..., getReturnValueSlot()); /// EmitMoveFromReturnSlot(E, Result); /// /// If nothing interferes, this will cause the result to be emitted /// directly into the return value slot. Otherwise, a final move /// will be performed. void AggExprEmitter::EmitMoveFromReturnSlot(const Expr *E, RValue src) { if (shouldUseDestForReturnSlot()) { // Logically, Dest.getAddr() should equal Src.getAggregateAddr(). // The possibility of undef rvalues complicates that a lot, // though, so we can't really assert. return; } // Otherwise, copy from there to the destination. assert(Dest.getAddr() != src.getAggregateAddr()); std::pair typeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); EmitFinalDestCopy(E->getType(), src, typeInfo.second); } /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src, CharUnits srcAlign) { assert(src.isAggregate() && "value must be aggregate value!"); LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddr(), type, srcAlign); EmitFinalDestCopy(type, srcLV); } /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src) { // If Dest is ignored, then we're evaluating an aggregate expression // in a context that doesn't care about the result. Note that loads // from volatile l-values force the existence of a non-ignored // destination. if (Dest.isIgnored()) return; AggValueSlot srcAgg = AggValueSlot::forLValue(src, AggValueSlot::IsDestructed, needsGC(type), AggValueSlot::IsAliased); EmitCopy(type, Dest, srcAgg); } /// Perform a copy from the source into the destination. /// /// \param type - the type of the aggregate being copied; qualifiers are /// ignored void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest, const AggValueSlot &src) { if (dest.requiresGCollection()) { CharUnits sz = CGF.getContext().getTypeSizeInChars(type); llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity()); CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, dest.getAddr(), src.getAddr(), size); return; } // If the result of the assignment is used, copy the LHS there also. // It's volatile if either side is. Use the minimum alignment of // the two sides. CGF.EmitAggregateCopy(dest.getAddr(), src.getAddr(), type, dest.isVolatile() || src.isVolatile(), std::min(dest.getAlignment(), src.getAlignment())); } /// \brief Emit the initializer for a std::initializer_list initialized with a /// real initializer list. void AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) { // Emit an array containing the elements. The array is externally destructed // if the std::initializer_list object is. ASTContext &Ctx = CGF.getContext(); LValue Array = CGF.EmitLValue(E->getSubExpr()); assert(Array.isSimple() && "initializer_list array not a simple lvalue"); llvm::Value *ArrayPtr = Array.getAddress(); const ConstantArrayType *ArrayType = Ctx.getAsConstantArrayType(E->getSubExpr()->getType()); assert(ArrayType && "std::initializer_list constructed from non-array"); // FIXME: Perform the checks on the field types in SemaInit. RecordDecl *Record = E->getType()->castAs()->getDecl(); RecordDecl::field_iterator Field = Record->field_begin(); if (Field == Record->field_end()) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } // Start pointer. if (!Field->getType()->isPointerType() || !Ctx.hasSameType(Field->getType()->getPointeeType(), ArrayType->getElementType())) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(), Dest.getAlignment()); LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field); llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0); llvm::Value *IdxStart[] = { Zero, Zero }; llvm::Value *ArrayStart = Builder.CreateInBoundsGEP(ArrayPtr, IdxStart, "arraystart"); CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start); ++Field; if (Field == Record->field_end()) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } llvm::Value *Size = Builder.getInt(ArrayType->getSize()); LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field); if (Field->getType()->isPointerType() && Ctx.hasSameType(Field->getType()->getPointeeType(), ArrayType->getElementType())) { // End pointer. llvm::Value *IdxEnd[] = { Zero, Size }; llvm::Value *ArrayEnd = Builder.CreateInBoundsGEP(ArrayPtr, IdxEnd, "arrayend"); CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength); } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) { // Length. CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength); } else { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } } /// \brief Determine if E is a trivial array filler, that is, one that is /// equivalent to zero-initialization. static bool isTrivialFiller(Expr *E) { if (!E) return true; if (isa(E)) return true; if (auto *ILE = dyn_cast(E)) { if (ILE->getNumInits()) return false; return isTrivialFiller(ILE->getArrayFiller()); } if (auto *Cons = dyn_cast_or_null(E)) return Cons->getConstructor()->isDefaultConstructor() && Cons->getConstructor()->isTrivial(); // FIXME: Are there other cases where we can avoid emitting an initializer? return false; } /// \brief Emit initialization of an array from an initializer list. void AggExprEmitter::EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType, QualType elementType, InitListExpr *E) { uint64_t NumInitElements = E->getNumInits(); uint64_t NumArrayElements = AType->getNumElements(); assert(NumInitElements <= NumArrayElements); // DestPtr is an array*. Construct an elementType* by drilling // down a level. llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); llvm::Value *indices[] = { zero, zero }; llvm::Value *begin = Builder.CreateInBoundsGEP(DestPtr, indices, "arrayinit.begin"); // Exception safety requires us to destroy all the // already-constructed members if an initializer throws. // For that, we'll need an EH cleanup. QualType::DestructionKind dtorKind = elementType.isDestructedType(); llvm::AllocaInst *endOfInit = nullptr; EHScopeStack::stable_iterator cleanup; llvm::Instruction *cleanupDominator = nullptr; if (CGF.needsEHCleanup(dtorKind)) { // In principle we could tell the cleanup where we are more // directly, but the control flow can get so varied here that it // would actually be quite complex. Therefore we go through an // alloca. endOfInit = CGF.CreateTempAlloca(begin->getType(), "arrayinit.endOfInit"); cleanupDominator = Builder.CreateStore(begin, endOfInit); CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType, CGF.getDestroyer(dtorKind)); cleanup = CGF.EHStack.stable_begin(); // Otherwise, remember that we didn't need a cleanup. } else { dtorKind = QualType::DK_none; } llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1); // The 'current element to initialize'. The invariants on this // variable are complicated. Essentially, after each iteration of // the loop, it points to the last initialized element, except // that it points to the beginning of the array before any // elements have been initialized. llvm::Value *element = begin; // Emit the explicit initializers. for (uint64_t i = 0; i != NumInitElements; ++i) { // Advance to the next element. if (i > 0) { element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element"); // Tell the cleanup that it needs to destroy up to this // element. TODO: some of these stores can be trivially // observed to be unnecessary. if (endOfInit) Builder.CreateStore(element, endOfInit); } LValue elementLV = CGF.MakeAddrLValue(element, elementType); EmitInitializationToLValue(E->getInit(i), elementLV); } // Check whether there's a non-trivial array-fill expression. Expr *filler = E->getArrayFiller(); bool hasTrivialFiller = isTrivialFiller(filler); // Any remaining elements need to be zero-initialized, possibly // using the filler expression. We can skip this if the we're // emitting to zeroed memory. if (NumInitElements != NumArrayElements && !(Dest.isZeroed() && hasTrivialFiller && CGF.getTypes().isZeroInitializable(elementType))) { // Use an actual loop. This is basically // do { *array++ = filler; } while (array != end); // Advance to the start of the rest of the array. if (NumInitElements) { element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start"); if (endOfInit) Builder.CreateStore(element, endOfInit); } // Compute the end of the array. llvm::Value *end = Builder.CreateInBoundsGEP(begin, llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements), "arrayinit.end"); llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body"); // Jump into the body. CGF.EmitBlock(bodyBB); llvm::PHINode *currentElement = Builder.CreatePHI(element->getType(), 2, "arrayinit.cur"); currentElement->addIncoming(element, entryBB); // Emit the actual filler expression. LValue elementLV = CGF.MakeAddrLValue(currentElement, elementType); if (filler) EmitInitializationToLValue(filler, elementLV); else EmitNullInitializationToLValue(elementLV); // Move on to the next element. llvm::Value *nextElement = Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next"); // Tell the EH cleanup that we finished with the last element. if (endOfInit) Builder.CreateStore(nextElement, endOfInit); // Leave the loop if we're done. llvm::Value *done = Builder.CreateICmpEQ(nextElement, end, "arrayinit.done"); llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end"); Builder.CreateCondBr(done, endBB, bodyBB); currentElement->addIncoming(nextElement, Builder.GetInsertBlock()); CGF.EmitBlock(endBB); } // Leave the partial-array cleanup if we entered one. if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator); } //===----------------------------------------------------------------------===// // Visitor Methods //===----------------------------------------------------------------------===// void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){ Visit(E->GetTemporaryExpr()); } void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) { EmitFinalDestCopy(e->getType(), CGF.getOpaqueLValueMapping(e)); } void AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { if (Dest.isPotentiallyAliased() && E->getType().isPODType(CGF.getContext())) { // For a POD type, just emit a load of the lvalue + a copy, because our // compound literal might alias the destination. EmitAggLoadOfLValue(E); return; } AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitAggExpr(E->getInitializer(), Slot); } /// Attempt to look through various unimportant expressions to find a /// cast of the given kind. static Expr *findPeephole(Expr *op, CastKind kind) { while (true) { op = op->IgnoreParens(); if (CastExpr *castE = dyn_cast(op)) { if (castE->getCastKind() == kind) return castE->getSubExpr(); if (castE->getCastKind() == CK_NoOp) continue; } return nullptr; } } void AggExprEmitter::VisitCastExpr(CastExpr *E) { switch (E->getCastKind()) { case CK_Dynamic: { // FIXME: Can this actually happen? We have no test coverage for it. assert(isa(E) && "CK_Dynamic without a dynamic_cast?"); LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(), CodeGenFunction::TCK_Load); // FIXME: Do we also need to handle property references here? if (LV.isSimple()) CGF.EmitDynamicCast(LV.getAddress(), cast(E)); else CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast"); if (!Dest.isIgnored()) CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination"); break; } case CK_ToUnion: { if (Dest.isIgnored()) break; // GCC union extension QualType Ty = E->getSubExpr()->getType(); QualType PtrTy = CGF.getContext().getPointerType(Ty); llvm::Value *CastPtr = Builder.CreateBitCast(Dest.getAddr(), CGF.ConvertType(PtrTy)); EmitInitializationToLValue(E->getSubExpr(), CGF.MakeAddrLValue(CastPtr, Ty)); break; } case CK_DerivedToBase: case CK_BaseToDerived: case CK_UncheckedDerivedToBase: { llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: " "should have been unpacked before we got here"); } case CK_NonAtomicToAtomic: case CK_AtomicToNonAtomic: { bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic); // Determine the atomic and value types. QualType atomicType = E->getSubExpr()->getType(); QualType valueType = E->getType(); if (isToAtomic) std::swap(atomicType, valueType); assert(atomicType->isAtomicType()); assert(CGF.getContext().hasSameUnqualifiedType(valueType, atomicType->castAs()->getValueType())); // Just recurse normally if we're ignoring the result or the // atomic type doesn't change representation. if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) { return Visit(E->getSubExpr()); } CastKind peepholeTarget = (isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic); // These two cases are reverses of each other; try to peephole them. if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) { assert(CGF.getContext().hasSameUnqualifiedType(op->getType(), E->getType()) && "peephole significantly changed types?"); return Visit(op); } // If we're converting an r-value of non-atomic type to an r-value // of atomic type, just emit directly into the relevant sub-object. if (isToAtomic) { AggValueSlot valueDest = Dest; if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) { // Zero-initialize. (Strictly speaking, we only need to intialize // the padding at the end, but this is simpler.) if (!Dest.isZeroed()) CGF.EmitNullInitialization(Dest.getAddr(), atomicType); // Build a GEP to refer to the subobject. llvm::Value *valueAddr = CGF.Builder.CreateStructGEP(valueDest.getAddr(), 0); valueDest = AggValueSlot::forAddr(valueAddr, valueDest.getAlignment(), valueDest.getQualifiers(), valueDest.isExternallyDestructed(), valueDest.requiresGCollection(), valueDest.isPotentiallyAliased(), AggValueSlot::IsZeroed); } CGF.EmitAggExpr(E->getSubExpr(), valueDest); return; } // Otherwise, we're converting an atomic type to a non-atomic type. // Make an atomic temporary, emit into that, and then copy the value out. AggValueSlot atomicSlot = CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp"); CGF.EmitAggExpr(E->getSubExpr(), atomicSlot); llvm::Value *valueAddr = Builder.CreateStructGEP(atomicSlot.getAddr(), 0); RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile()); return EmitFinalDestCopy(valueType, rvalue); } case CK_LValueToRValue: // If we're loading from a volatile type, force the destination // into existence. if (E->getSubExpr()->getType().isVolatileQualified()) { EnsureDest(E->getType()); return Visit(E->getSubExpr()); } // fallthrough case CK_NoOp: case CK_UserDefinedConversion: case CK_ConstructorConversion: assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(), E->getType()) && "Implicit cast types must be compatible"); Visit(E->getSubExpr()); break; case CK_LValueBitCast: llvm_unreachable("should not be emitting lvalue bitcast as rvalue"); case CK_Dependent: case CK_BitCast: case CK_ArrayToPointerDecay: case CK_FunctionToPointerDecay: case CK_NullToPointer: case CK_NullToMemberPointer: case CK_BaseToDerivedMemberPointer: case CK_DerivedToBaseMemberPointer: case CK_MemberPointerToBoolean: case CK_ReinterpretMemberPointer: case CK_IntegralToPointer: case CK_PointerToIntegral: case CK_PointerToBoolean: case CK_ToVoid: case CK_VectorSplat: case CK_IntegralCast: case CK_IntegralToBoolean: case CK_IntegralToFloating: case CK_FloatingToIntegral: case CK_FloatingToBoolean: case CK_FloatingCast: case CK_CPointerToObjCPointerCast: case CK_BlockPointerToObjCPointerCast: case CK_AnyPointerToBlockPointerCast: case CK_ObjCObjectLValueCast: case CK_FloatingRealToComplex: case CK_FloatingComplexToReal: case CK_FloatingComplexToBoolean: case CK_FloatingComplexCast: case CK_FloatingComplexToIntegralComplex: case CK_IntegralRealToComplex: case CK_IntegralComplexToReal: case CK_IntegralComplexToBoolean: case CK_IntegralComplexCast: case CK_IntegralComplexToFloatingComplex: case CK_ARCProduceObject: case CK_ARCConsumeObject: case CK_ARCReclaimReturnedObject: case CK_ARCExtendBlockObject: case CK_CopyAndAutoreleaseBlockObject: case CK_BuiltinFnToFnPtr: case CK_ZeroToOCLEvent: case CK_AddressSpaceConversion: llvm_unreachable("cast kind invalid for aggregate types"); } } void AggExprEmitter::VisitCallExpr(const CallExpr *E) { if (E->getCallReturnType()->isReferenceType()) { EmitAggLoadOfLValue(E); return; } RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot()); EmitMoveFromReturnSlot(E, RV); } void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot()); EmitMoveFromReturnSlot(E, RV); } void AggExprEmitter::VisitBinComma(const BinaryOperator *E) { CGF.EmitIgnoredExpr(E->getLHS()); Visit(E->getRHS()); } void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) { CodeGenFunction::StmtExprEvaluation eval(CGF); CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest); } void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) { if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI) VisitPointerToDataMemberBinaryOperator(E); else CGF.ErrorUnsupported(E, "aggregate binary expression"); } void AggExprEmitter::VisitPointerToDataMemberBinaryOperator( const BinaryOperator *E) { LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E); EmitFinalDestCopy(E->getType(), LV); } /// Is the value of the given expression possibly a reference to or /// into a __block variable? static bool isBlockVarRef(const Expr *E) { // Make sure we look through parens. E = E->IgnoreParens(); // Check for a direct reference to a __block variable. if (const DeclRefExpr *DRE = dyn_cast(E)) { const VarDecl *var = dyn_cast(DRE->getDecl()); return (var && var->hasAttr()); } // More complicated stuff. // Binary operators. if (const BinaryOperator *op = dyn_cast(E)) { // For an assignment or pointer-to-member operation, just care // about the LHS. if (op->isAssignmentOp() || op->isPtrMemOp()) return isBlockVarRef(op->getLHS()); // For a comma, just care about the RHS. if (op->getOpcode() == BO_Comma) return isBlockVarRef(op->getRHS()); // FIXME: pointer arithmetic? return false; // Check both sides of a conditional operator. } else if (const AbstractConditionalOperator *op = dyn_cast(E)) { return isBlockVarRef(op->getTrueExpr()) || isBlockVarRef(op->getFalseExpr()); // OVEs are required to support BinaryConditionalOperators. } else if (const OpaqueValueExpr *op = dyn_cast(E)) { if (const Expr *src = op->getSourceExpr()) return isBlockVarRef(src); // Casts are necessary to get things like (*(int*)&var) = foo(). // We don't really care about the kind of cast here, except // we don't want to look through l2r casts, because it's okay // to get the *value* in a __block variable. } else if (const CastExpr *cast = dyn_cast(E)) { if (cast->getCastKind() == CK_LValueToRValue) return false; return isBlockVarRef(cast->getSubExpr()); // Handle unary operators. Again, just aggressively look through // it, ignoring the operation. } else if (const UnaryOperator *uop = dyn_cast(E)) { return isBlockVarRef(uop->getSubExpr()); // Look into the base of a field access. } else if (const MemberExpr *mem = dyn_cast(E)) { return isBlockVarRef(mem->getBase()); // Look into the base of a subscript. } else if (const ArraySubscriptExpr *sub = dyn_cast(E)) { return isBlockVarRef(sub->getBase()); } return false; } void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) { // For an assignment to work, the value on the right has // to be compatible with the value on the left. assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(), E->getRHS()->getType()) && "Invalid assignment"); // If the LHS might be a __block variable, and the RHS can // potentially cause a block copy, we need to evaluate the RHS first // so that the assignment goes the right place. // This is pretty semantically fragile. if (isBlockVarRef(E->getLHS()) && E->getRHS()->HasSideEffects(CGF.getContext())) { // Ensure that we have a destination, and evaluate the RHS into that. EnsureDest(E->getRHS()->getType()); Visit(E->getRHS()); // Now emit the LHS and copy into it. LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); // That copy is an atomic copy if the LHS is atomic. if (LHS.getType()->isAtomicType()) { CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); return; } EmitCopy(E->getLHS()->getType(), AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()), AggValueSlot::IsAliased), Dest); return; } LValue LHS = CGF.EmitLValue(E->getLHS()); // If we have an atomic type, evaluate into the destination and then // do an atomic copy. if (LHS.getType()->isAtomicType()) { EnsureDest(E->getRHS()->getType()); Visit(E->getRHS()); CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); return; } // Codegen the RHS so that it stores directly into the LHS. AggValueSlot LHSSlot = AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()), AggValueSlot::IsAliased); // A non-volatile aggregate destination might have volatile member. if (!LHSSlot.isVolatile() && CGF.hasVolatileMember(E->getLHS()->getType())) LHSSlot.setVolatile(true); CGF.EmitAggExpr(E->getRHS(), LHSSlot); // Copy into the destination if the assignment isn't ignored. EmitFinalDestCopy(E->getType(), LHS); } void AggExprEmitter:: VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); // Bind the common expression if necessary. CodeGenFunction::OpaqueValueMapping binding(CGF, E); RegionCounter Cnt = CGF.getPGORegionCounter(E); CodeGenFunction::ConditionalEvaluation eval(CGF); CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, Cnt.getCount()); // Save whether the destination's lifetime is externally managed. bool isExternallyDestructed = Dest.isExternallyDestructed(); eval.begin(CGF); CGF.EmitBlock(LHSBlock); Cnt.beginRegion(Builder); Visit(E->getTrueExpr()); eval.end(CGF); assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!"); CGF.Builder.CreateBr(ContBlock); // If the result of an agg expression is unused, then the emission // of the LHS might need to create a destination slot. That's fine // with us, and we can safely emit the RHS into the same slot, but // we shouldn't claim that it's already being destructed. Dest.setExternallyDestructed(isExternallyDestructed); eval.begin(CGF); CGF.EmitBlock(RHSBlock); Visit(E->getFalseExpr()); eval.end(CGF); CGF.EmitBlock(ContBlock); } void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) { Visit(CE->getChosenSubExpr()); } void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); if (!ArgPtr) { // If EmitVAArg fails, we fall back to the LLVM instruction. llvm::Value *Val = Builder.CreateVAArg(ArgValue, CGF.ConvertType(VE->getType())); if (!Dest.isIgnored()) Builder.CreateStore(Val, Dest.getAddr()); return; } EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType())); } void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { // Ensure that we have a slot, but if we already do, remember // whether it was externally destructed. bool wasExternallyDestructed = Dest.isExternallyDestructed(); EnsureDest(E->getType()); // We're going to push a destructor if there isn't already one. Dest.setExternallyDestructed(); Visit(E->getSubExpr()); // Push that destructor we promised. if (!wasExternallyDestructed) CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddr()); } void AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitCXXConstructExpr(E, Slot); } void AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitLambdaExpr(E, Slot); } void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) { CGF.enterFullExpression(E); CodeGenFunction::RunCleanupsScope cleanups(CGF); Visit(E->getSubExpr()); } void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) { QualType T = E->getType(); AggValueSlot Slot = EnsureSlot(T); EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T)); } void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) { QualType T = E->getType(); AggValueSlot Slot = EnsureSlot(T); EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T)); } /// isSimpleZero - If emitting this value will obviously just cause a store of /// zero to memory, return true. This can return false if uncertain, so it just /// handles simple cases. static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) { E = E->IgnoreParens(); // 0 if (const IntegerLiteral *IL = dyn_cast(E)) return IL->getValue() == 0; // +0.0 if (const FloatingLiteral *FL = dyn_cast(E)) return FL->getValue().isPosZero(); // int() if ((isa(E) || isa(E)) && CGF.getTypes().isZeroInitializable(E->getType())) return true; // (int*)0 - Null pointer expressions. if (const CastExpr *ICE = dyn_cast(E)) return ICE->getCastKind() == CK_NullToPointer; // '\0' if (const CharacterLiteral *CL = dyn_cast(E)) return CL->getValue() == 0; // Otherwise, hard case: conservatively return false. return false; } void AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) { QualType type = LV.getType(); // FIXME: Ignore result? // FIXME: Are initializers affected by volatile? if (Dest.isZeroed() && isSimpleZero(E, CGF)) { // Storing "i32 0" to a zero'd memory location is a noop. return; } else if (isa(E) || isa(E)) { return EmitNullInitializationToLValue(LV); } else if (type->isReferenceType()) { RValue RV = CGF.EmitReferenceBindingToExpr(E); return CGF.EmitStoreThroughLValue(RV, LV); } switch (CGF.getEvaluationKind(type)) { case TEK_Complex: CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true); return; case TEK_Aggregate: CGF.EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, Dest.isZeroed())); return; case TEK_Scalar: if (LV.isSimple()) { CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false); } else { CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV); } return; } llvm_unreachable("bad evaluation kind"); } void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) { QualType type = lv.getType(); // If the destination slot is already zeroed out before the aggregate is // copied into it, we don't have to emit any zeros here. if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type)) return; if (CGF.hasScalarEvaluationKind(type)) { // For non-aggregates, we can store the appropriate null constant. llvm::Value *null = CGF.CGM.EmitNullConstant(type); // Note that the following is not equivalent to // EmitStoreThroughBitfieldLValue for ARC types. if (lv.isBitField()) { CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv); } else { assert(lv.isSimple()); CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true); } } else { // There's a potential optimization opportunity in combining // memsets; that would be easy for arrays, but relatively // difficult for structures with the current code. CGF.EmitNullInitialization(lv.getAddress(), lv.getType()); } } void AggExprEmitter::VisitInitListExpr(InitListExpr *E) { #if 0 // FIXME: Assess perf here? Figure out what cases are worth optimizing here // (Length of globals? Chunks of zeroed-out space?). // // If we can, prefer a copy from a global; this is a lot less code for long // globals, and it's easier for the current optimizers to analyze. if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) { llvm::GlobalVariable* GV = new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true, llvm::GlobalValue::InternalLinkage, C, ""); EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType())); return; } #endif if (E->hadArrayRangeDesignator()) CGF.ErrorUnsupported(E, "GNU array range designator extension"); AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(), Dest.getAlignment()); // Handle initialization of an array. if (E->getType()->isArrayType()) { if (E->isStringLiteralInit()) return Visit(E->getInit(0)); QualType elementType = CGF.getContext().getAsArrayType(E->getType())->getElementType(); llvm::PointerType *APType = cast(Dest.getAddr()->getType()); llvm::ArrayType *AType = cast(APType->getElementType()); EmitArrayInit(Dest.getAddr(), AType, elementType, E); return; } if (E->getType()->isAtomicType()) { // An _Atomic(T) object can be list-initialized from an expression // of the same type. assert(E->getNumInits() == 1 && CGF.getContext().hasSameUnqualifiedType(E->getInit(0)->getType(), E->getType()) && "unexpected list initialization for atomic object"); return Visit(E->getInit(0)); } assert(E->getType()->isRecordType() && "Only support structs/unions here!"); // Do struct initialization; this code just sets each individual member // to the approprate value. This makes bitfield support automatic; // the disadvantage is that the generated code is more difficult for // the optimizer, especially with bitfields. unsigned NumInitElements = E->getNumInits(); RecordDecl *record = E->getType()->castAs()->getDecl(); // Prepare a 'this' for CXXDefaultInitExprs. CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddr()); if (record->isUnion()) { // Only initialize one field of a union. The field itself is // specified by the initializer list. if (!E->getInitializedFieldInUnion()) { // Empty union; we have nothing to do. #ifndef NDEBUG // Make sure that it's really an empty and not a failure of // semantic analysis. for (const auto *Field : record->fields()) assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed"); #endif return; } // FIXME: volatility FieldDecl *Field = E->getInitializedFieldInUnion(); LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field); if (NumInitElements) { // Store the initializer into the field EmitInitializationToLValue(E->getInit(0), FieldLoc); } else { // Default-initialize to null. EmitNullInitializationToLValue(FieldLoc); } return; } // We'll need to enter cleanup scopes in case any of the member // initializers throw an exception. SmallVector cleanups; llvm::Instruction *cleanupDominator = nullptr; // Here we iterate over the fields; this makes it simpler to both // default-initialize fields and skip over unnamed fields. unsigned curInitIndex = 0; for (const auto *field : record->fields()) { // We're done once we hit the flexible array member. if (field->getType()->isIncompleteArrayType()) break; // Always skip anonymous bitfields. if (field->isUnnamedBitfield()) continue; // We're done if we reach the end of the explicit initializers, we // have a zeroed object, and the rest of the fields are // zero-initializable. if (curInitIndex == NumInitElements && Dest.isZeroed() && CGF.getTypes().isZeroInitializable(E->getType())) break; LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field); // We never generate write-barries for initialized fields. LV.setNonGC(true); if (curInitIndex < NumInitElements) { // Store the initializer into the field. EmitInitializationToLValue(E->getInit(curInitIndex++), LV); } else { // We're out of initalizers; default-initialize to null EmitNullInitializationToLValue(LV); } // Push a destructor if necessary. // FIXME: if we have an array of structures, all explicitly // initialized, we can end up pushing a linear number of cleanups. bool pushedCleanup = false; if (QualType::DestructionKind dtorKind = field->getType().isDestructedType()) { assert(LV.isSimple()); if (CGF.needsEHCleanup(dtorKind)) { if (!cleanupDominator) cleanupDominator = CGF.Builder.CreateUnreachable(); // placeholder CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(), CGF.getDestroyer(dtorKind), false); cleanups.push_back(CGF.EHStack.stable_begin()); pushedCleanup = true; } } // If the GEP didn't get used because of a dead zero init or something // else, clean it up for -O0 builds and general tidiness. if (!pushedCleanup && LV.isSimple()) if (llvm::GetElementPtrInst *GEP = dyn_cast(LV.getAddress())) if (GEP->use_empty()) GEP->eraseFromParent(); } // Deactivate all the partial cleanups in reverse order, which // generally means popping them. for (unsigned i = cleanups.size(); i != 0; --i) CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator); // Destroy the placeholder if we made one. if (cleanupDominator) cleanupDominator->eraseFromParent(); } //===----------------------------------------------------------------------===// // Entry Points into this File //===----------------------------------------------------------------------===// /// GetNumNonZeroBytesInInit - Get an approximate count of the number of /// non-zero bytes that will be stored when outputting the initializer for the /// specified initializer expression. static CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF) { E = E->IgnoreParens(); // 0 and 0.0 won't require any non-zero stores! if (isSimpleZero(E, CGF)) return CharUnits::Zero(); // If this is an initlist expr, sum up the size of sizes of the (present) // elements. If this is something weird, assume the whole thing is non-zero. const InitListExpr *ILE = dyn_cast(E); if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType())) return CGF.getContext().getTypeSizeInChars(E->getType()); // InitListExprs for structs have to be handled carefully. If there are // reference members, we need to consider the size of the reference, not the // referencee. InitListExprs for unions and arrays can't have references. if (const RecordType *RT = E->getType()->getAs()) { if (!RT->isUnionType()) { RecordDecl *SD = E->getType()->getAs()->getDecl(); CharUnits NumNonZeroBytes = CharUnits::Zero(); unsigned ILEElement = 0; for (const auto *Field : SD->fields()) { // We're done once we hit the flexible array member or run out of // InitListExpr elements. if (Field->getType()->isIncompleteArrayType() || ILEElement == ILE->getNumInits()) break; if (Field->isUnnamedBitfield()) continue; const Expr *E = ILE->getInit(ILEElement++); // Reference values are always non-null and have the width of a pointer. if (Field->getType()->isReferenceType()) NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits( CGF.getTarget().getPointerWidth(0)); else NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF); } return NumNonZeroBytes; } } CharUnits NumNonZeroBytes = CharUnits::Zero(); for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF); return NumNonZeroBytes; } /// CheckAggExprForMemSetUse - If the initializer is large and has a lot of /// zeros in it, emit a memset and avoid storing the individual zeros. /// static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E, CodeGenFunction &CGF) { // If the slot is already known to be zeroed, nothing to do. Don't mess with // volatile stores. if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == nullptr) return; // C++ objects with a user-declared constructor don't need zero'ing. if (CGF.getLangOpts().CPlusPlus) if (const RecordType *RT = CGF.getContext() .getBaseElementType(E->getType())->getAs()) { const CXXRecordDecl *RD = cast(RT->getDecl()); if (RD->hasUserDeclaredConstructor()) return; } // If the type is 16-bytes or smaller, prefer individual stores over memset. std::pair TypeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); if (TypeInfo.first <= CharUnits::fromQuantity(16)) return; // Check to see if over 3/4 of the initializer are known to be zero. If so, // we prefer to emit memset + individual stores for the rest. CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF); if (NumNonZeroBytes*4 > TypeInfo.first) return; // Okay, it seems like a good idea to use an initial memset, emit the call. llvm::Constant *SizeVal = CGF.Builder.getInt64(TypeInfo.first.getQuantity()); CharUnits Align = TypeInfo.second; llvm::Value *Loc = Slot.getAddr(); Loc = CGF.Builder.CreateBitCast(Loc, CGF.Int8PtrTy); CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, Align.getQuantity(), false); // Tell the AggExprEmitter that the slot is known zero. Slot.setZeroed(); } /// EmitAggExpr - Emit the computation of the specified expression of aggregate /// type. The result is computed into DestPtr. Note that if DestPtr is null, /// the value of the aggregate expression is not needed. If VolatileDest is /// true, DestPtr cannot be 0. void CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot) { assert(E && hasAggregateEvaluationKind(E->getType()) && "Invalid aggregate expression to emit"); assert((Slot.getAddr() != nullptr || Slot.isIgnored()) && "slot has bits but no address"); // Optimize the slot if possible. CheckAggExprForMemSetUse(Slot, E, *this); AggExprEmitter(*this, Slot).Visit(const_cast(E)); } LValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) { assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!"); llvm::Value *Temp = CreateMemTemp(E->getType()); LValue LV = MakeAddrLValue(Temp, E->getType()); EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased)); return LV; } void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr, llvm::Value *SrcPtr, QualType Ty, bool isVolatile, CharUnits alignment, bool isAssignment) { assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); if (getLangOpts().CPlusPlus) { if (const RecordType *RT = Ty->getAs()) { CXXRecordDecl *Record = cast(RT->getDecl()); assert((Record->hasTrivialCopyConstructor() || Record->hasTrivialCopyAssignment() || Record->hasTrivialMoveConstructor() || Record->hasTrivialMoveAssignment()) && "Trying to aggregate-copy a type without a trivial copy/move " "constructor or assignment operator"); // Ignore empty classes in C++. if (Record->isEmpty()) return; } } // Aggregate assignment turns into llvm.memcpy. This is almost valid per // C99 6.5.16.1p3, which states "If the value being stored in an object is // read from another object that overlaps in anyway the storage of the first // object, then the overlap shall be exact and the two objects shall have // qualified or unqualified versions of a compatible type." // // memcpy is not defined if the source and destination pointers are exactly // equal, but other compilers do this optimization, and almost every memcpy // implementation handles this case safely. If there is a libc that does not // safely handle this, we can add a target hook. // Get data size and alignment info for this aggregate. If this is an // assignment don't copy the tail padding. Otherwise copying it is fine. std::pair TypeInfo; if (isAssignment) TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty); else TypeInfo = getContext().getTypeInfoInChars(Ty); if (alignment.isZero()) alignment = TypeInfo.second; // FIXME: Handle variable sized types. // FIXME: If we have a volatile struct, the optimizer can remove what might // appear to be `extra' memory ops: // // volatile struct { int i; } a, b; // // int main() { // a = b; // a = b; // } // // we need to use a different call here. We use isVolatile to indicate when // either the source or the destination is volatile. llvm::PointerType *DPT = cast(DestPtr->getType()); llvm::Type *DBP = llvm::Type::getInt8PtrTy(getLLVMContext(), DPT->getAddressSpace()); DestPtr = Builder.CreateBitCast(DestPtr, DBP); llvm::PointerType *SPT = cast(SrcPtr->getType()); llvm::Type *SBP = llvm::Type::getInt8PtrTy(getLLVMContext(), SPT->getAddressSpace()); SrcPtr = Builder.CreateBitCast(SrcPtr, SBP); // Don't do any of the memmove_collectable tests if GC isn't set. if (CGM.getLangOpts().getGC() == LangOptions::NonGC) { // fall through } else if (const RecordType *RecordTy = Ty->getAs()) { RecordDecl *Record = RecordTy->getDecl(); if (Record->hasObjectMember()) { CharUnits size = TypeInfo.first; llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity()); CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, SizeVal); return; } } else if (Ty->isArrayType()) { QualType BaseType = getContext().getBaseElementType(Ty); if (const RecordType *RecordTy = BaseType->getAs()) { if (RecordTy->getDecl()->hasObjectMember()) { CharUnits size = TypeInfo.first; llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity()); CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, SizeVal); return; } } } // Determine the metadata to describe the position of any padding in this // memcpy, as well as the TBAA tags for the members of the struct, in case // the optimizer wishes to expand it in to scalar memory operations. llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty); Builder.CreateMemCpy(DestPtr, SrcPtr, llvm::ConstantInt::get(IntPtrTy, TypeInfo.first.getQuantity()), alignment.getQuantity(), isVolatile, /*TBAATag=*/nullptr, TBAAStructTag); } @ 1.1.1.5.4.1 log @file CGExprAgg.cpp was added on branch yamt-pagecache on 2014-05-22 16:18:26 +0000 @ text @d1 1482 @ 1.1.1.5.4.2 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 @a0 1482 //===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This contains code to emit Aggregate Expr nodes as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CGObjCRuntime.h" #include "CodeGenModule.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/StmtVisitor.h" #include "llvm/IR/Constants.h" #include "llvm/IR/Function.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Intrinsics.h" using namespace clang; using namespace CodeGen; //===----------------------------------------------------------------------===// // Aggregate Expression Emitter //===----------------------------------------------------------------------===// namespace { class AggExprEmitter : public StmtVisitor { CodeGenFunction &CGF; CGBuilderTy &Builder; AggValueSlot Dest; /// We want to use 'dest' as the return slot except under two /// conditions: /// - The destination slot requires garbage collection, so we /// need to use the GC API. /// - The destination slot is potentially aliased. bool shouldUseDestForReturnSlot() const { return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased()); } ReturnValueSlot getReturnValueSlot() const { if (!shouldUseDestForReturnSlot()) return ReturnValueSlot(); return ReturnValueSlot(Dest.getAddr(), Dest.isVolatile()); } AggValueSlot EnsureSlot(QualType T) { if (!Dest.isIgnored()) return Dest; return CGF.CreateAggTemp(T, "agg.tmp.ensured"); } void EnsureDest(QualType T) { if (!Dest.isIgnored()) return; Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured"); } public: AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest) : CGF(cgf), Builder(CGF.Builder), Dest(Dest) { } //===--------------------------------------------------------------------===// // Utilities //===--------------------------------------------------------------------===// /// EmitAggLoadOfLValue - Given an expression with aggregate type that /// represents a value lvalue, this method emits the address of the lvalue, /// then loads the result into DestPtr. void EmitAggLoadOfLValue(const Expr *E); /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void EmitFinalDestCopy(QualType type, const LValue &src); void EmitFinalDestCopy(QualType type, RValue src, CharUnits srcAlignment = CharUnits::Zero()); void EmitCopy(QualType type, const AggValueSlot &dest, const AggValueSlot &src); void EmitMoveFromReturnSlot(const Expr *E, RValue Src); void EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType, QualType elementType, InitListExpr *E); AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) { if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T)) return AggValueSlot::NeedsGCBarriers; return AggValueSlot::DoesNotNeedGCBarriers; } bool TypeRequiresGCollection(QualType T); //===--------------------------------------------------------------------===// // Visitor Methods //===--------------------------------------------------------------------===// void VisitStmt(Stmt *S) { CGF.ErrorUnsupported(S, "aggregate expression"); } void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); } void VisitGenericSelectionExpr(GenericSelectionExpr *GE) { Visit(GE->getResultExpr()); } void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); } void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { return Visit(E->getReplacement()); } // l-values. void VisitDeclRefExpr(DeclRefExpr *E) { // For aggregates, we should always be able to emit the variable // as an l-value unless it's a reference. This is due to the fact // that we can't actually ever see a normal l2r conversion on an // aggregate in C++, and in C there's no language standard // actively preventing us from listing variables in the captures // list of a block. if (E->getDecl()->getType()->isReferenceType()) { if (CodeGenFunction::ConstantEmission result = CGF.tryEmitAsConstant(E)) { EmitFinalDestCopy(E->getType(), result.getReferenceLValue(CGF, E)); return; } } EmitAggLoadOfLValue(E); } void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); } void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); } void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); } void VisitCompoundLiteralExpr(CompoundLiteralExpr *E); void VisitArraySubscriptExpr(ArraySubscriptExpr *E) { EmitAggLoadOfLValue(E); } void VisitPredefinedExpr(const PredefinedExpr *E) { EmitAggLoadOfLValue(E); } // Operators. void VisitCastExpr(CastExpr *E); void VisitCallExpr(const CallExpr *E); void VisitStmtExpr(const StmtExpr *E); void VisitBinaryOperator(const BinaryOperator *BO); void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO); void VisitBinAssign(const BinaryOperator *E); void VisitBinComma(const BinaryOperator *E); void VisitObjCMessageExpr(ObjCMessageExpr *E); void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { EmitAggLoadOfLValue(E); } void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO); void VisitChooseExpr(const ChooseExpr *CE); void VisitInitListExpr(InitListExpr *E); void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E); void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { Visit(DAE->getExpr()); } void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { CodeGenFunction::CXXDefaultInitExprScope Scope(CGF); Visit(DIE->getExpr()); } void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E); void VisitCXXConstructExpr(const CXXConstructExpr *E); void VisitLambdaExpr(LambdaExpr *E); void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E); void VisitExprWithCleanups(ExprWithCleanups *E); void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E); void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); } void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E); void VisitOpaqueValueExpr(OpaqueValueExpr *E); void VisitPseudoObjectExpr(PseudoObjectExpr *E) { if (E->isGLValue()) { LValue LV = CGF.EmitPseudoObjectLValue(E); return EmitFinalDestCopy(E->getType(), LV); } CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType())); } void VisitVAArgExpr(VAArgExpr *E); void EmitInitializationToLValue(Expr *E, LValue Address); void EmitNullInitializationToLValue(LValue Address); // case Expr::ChooseExprClass: void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); } void VisitAtomicExpr(AtomicExpr *E) { CGF.EmitAtomicExpr(E, EnsureSlot(E->getType()).getAddr()); } }; } // end anonymous namespace. //===----------------------------------------------------------------------===// // Utilities //===----------------------------------------------------------------------===// /// EmitAggLoadOfLValue - Given an expression with aggregate type that /// represents a value lvalue, this method emits the address of the lvalue, /// then loads the result into DestPtr. void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) { LValue LV = CGF.EmitLValue(E); // If the type of the l-value is atomic, then do an atomic load. if (LV.getType()->isAtomicType()) { CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest); return; } EmitFinalDestCopy(E->getType(), LV); } /// \brief True if the given aggregate type requires special GC API calls. bool AggExprEmitter::TypeRequiresGCollection(QualType T) { // Only record types have members that might require garbage collection. const RecordType *RecordTy = T->getAs(); if (!RecordTy) return false; // Don't mess with non-trivial C++ types. RecordDecl *Record = RecordTy->getDecl(); if (isa(Record) && (cast(Record)->hasNonTrivialCopyConstructor() || !cast(Record)->hasTrivialDestructor())) return false; // Check whether the type has an object member. return Record->hasObjectMember(); } /// \brief Perform the final move to DestPtr if for some reason /// getReturnValueSlot() didn't use it directly. /// /// The idea is that you do something like this: /// RValue Result = EmitSomething(..., getReturnValueSlot()); /// EmitMoveFromReturnSlot(E, Result); /// /// If nothing interferes, this will cause the result to be emitted /// directly into the return value slot. Otherwise, a final move /// will be performed. void AggExprEmitter::EmitMoveFromReturnSlot(const Expr *E, RValue src) { if (shouldUseDestForReturnSlot()) { // Logically, Dest.getAddr() should equal Src.getAggregateAddr(). // The possibility of undef rvalues complicates that a lot, // though, so we can't really assert. return; } // Otherwise, copy from there to the destination. assert(Dest.getAddr() != src.getAggregateAddr()); std::pair typeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); EmitFinalDestCopy(E->getType(), src, typeInfo.second); } /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src, CharUnits srcAlign) { assert(src.isAggregate() && "value must be aggregate value!"); LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddr(), type, srcAlign); EmitFinalDestCopy(type, srcLV); } /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src) { // If Dest is ignored, then we're evaluating an aggregate expression // in a context that doesn't care about the result. Note that loads // from volatile l-values force the existence of a non-ignored // destination. if (Dest.isIgnored()) return; AggValueSlot srcAgg = AggValueSlot::forLValue(src, AggValueSlot::IsDestructed, needsGC(type), AggValueSlot::IsAliased); EmitCopy(type, Dest, srcAgg); } /// Perform a copy from the source into the destination. /// /// \param type - the type of the aggregate being copied; qualifiers are /// ignored void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest, const AggValueSlot &src) { if (dest.requiresGCollection()) { CharUnits sz = CGF.getContext().getTypeSizeInChars(type); llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity()); CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, dest.getAddr(), src.getAddr(), size); return; } // If the result of the assignment is used, copy the LHS there also. // It's volatile if either side is. Use the minimum alignment of // the two sides. CGF.EmitAggregateCopy(dest.getAddr(), src.getAddr(), type, dest.isVolatile() || src.isVolatile(), std::min(dest.getAlignment(), src.getAlignment())); } /// \brief Emit the initializer for a std::initializer_list initialized with a /// real initializer list. void AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) { // Emit an array containing the elements. The array is externally destructed // if the std::initializer_list object is. ASTContext &Ctx = CGF.getContext(); LValue Array = CGF.EmitLValue(E->getSubExpr()); assert(Array.isSimple() && "initializer_list array not a simple lvalue"); llvm::Value *ArrayPtr = Array.getAddress(); const ConstantArrayType *ArrayType = Ctx.getAsConstantArrayType(E->getSubExpr()->getType()); assert(ArrayType && "std::initializer_list constructed from non-array"); // FIXME: Perform the checks on the field types in SemaInit. RecordDecl *Record = E->getType()->castAs()->getDecl(); RecordDecl::field_iterator Field = Record->field_begin(); if (Field == Record->field_end()) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } // Start pointer. if (!Field->getType()->isPointerType() || !Ctx.hasSameType(Field->getType()->getPointeeType(), ArrayType->getElementType())) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(), Dest.getAlignment()); LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field); llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0); llvm::Value *IdxStart[] = { Zero, Zero }; llvm::Value *ArrayStart = Builder.CreateInBoundsGEP(ArrayPtr, IdxStart, "arraystart"); CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start); ++Field; if (Field == Record->field_end()) { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } llvm::Value *Size = Builder.getInt(ArrayType->getSize()); LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field); if (Field->getType()->isPointerType() && Ctx.hasSameType(Field->getType()->getPointeeType(), ArrayType->getElementType())) { // End pointer. llvm::Value *IdxEnd[] = { Zero, Size }; llvm::Value *ArrayEnd = Builder.CreateInBoundsGEP(ArrayPtr, IdxEnd, "arrayend"); CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength); } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) { // Length. CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength); } else { CGF.ErrorUnsupported(E, "weird std::initializer_list"); return; } } /// \brief Emit initialization of an array from an initializer list. void AggExprEmitter::EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType, QualType elementType, InitListExpr *E) { uint64_t NumInitElements = E->getNumInits(); uint64_t NumArrayElements = AType->getNumElements(); assert(NumInitElements <= NumArrayElements); // DestPtr is an array*. Construct an elementType* by drilling // down a level. llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); llvm::Value *indices[] = { zero, zero }; llvm::Value *begin = Builder.CreateInBoundsGEP(DestPtr, indices, "arrayinit.begin"); // Exception safety requires us to destroy all the // already-constructed members if an initializer throws. // For that, we'll need an EH cleanup. QualType::DestructionKind dtorKind = elementType.isDestructedType(); llvm::AllocaInst *endOfInit = 0; EHScopeStack::stable_iterator cleanup; llvm::Instruction *cleanupDominator = 0; if (CGF.needsEHCleanup(dtorKind)) { // In principle we could tell the cleanup where we are more // directly, but the control flow can get so varied here that it // would actually be quite complex. Therefore we go through an // alloca. endOfInit = CGF.CreateTempAlloca(begin->getType(), "arrayinit.endOfInit"); cleanupDominator = Builder.CreateStore(begin, endOfInit); CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType, CGF.getDestroyer(dtorKind)); cleanup = CGF.EHStack.stable_begin(); // Otherwise, remember that we didn't need a cleanup. } else { dtorKind = QualType::DK_none; } llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1); // The 'current element to initialize'. The invariants on this // variable are complicated. Essentially, after each iteration of // the loop, it points to the last initialized element, except // that it points to the beginning of the array before any // elements have been initialized. llvm::Value *element = begin; // Emit the explicit initializers. for (uint64_t i = 0; i != NumInitElements; ++i) { // Advance to the next element. if (i > 0) { element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element"); // Tell the cleanup that it needs to destroy up to this // element. TODO: some of these stores can be trivially // observed to be unnecessary. if (endOfInit) Builder.CreateStore(element, endOfInit); } LValue elementLV = CGF.MakeAddrLValue(element, elementType); EmitInitializationToLValue(E->getInit(i), elementLV); } // Check whether there's a non-trivial array-fill expression. // Note that this will be a CXXConstructExpr even if the element // type is an array (or array of array, etc.) of class type. Expr *filler = E->getArrayFiller(); bool hasTrivialFiller = true; if (CXXConstructExpr *cons = dyn_cast_or_null(filler)) { assert(cons->getConstructor()->isDefaultConstructor()); hasTrivialFiller = cons->getConstructor()->isTrivial(); } // Any remaining elements need to be zero-initialized, possibly // using the filler expression. We can skip this if the we're // emitting to zeroed memory. if (NumInitElements != NumArrayElements && !(Dest.isZeroed() && hasTrivialFiller && CGF.getTypes().isZeroInitializable(elementType))) { // Use an actual loop. This is basically // do { *array++ = filler; } while (array != end); // Advance to the start of the rest of the array. if (NumInitElements) { element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start"); if (endOfInit) Builder.CreateStore(element, endOfInit); } // Compute the end of the array. llvm::Value *end = Builder.CreateInBoundsGEP(begin, llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements), "arrayinit.end"); llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body"); // Jump into the body. CGF.EmitBlock(bodyBB); llvm::PHINode *currentElement = Builder.CreatePHI(element->getType(), 2, "arrayinit.cur"); currentElement->addIncoming(element, entryBB); // Emit the actual filler expression. LValue elementLV = CGF.MakeAddrLValue(currentElement, elementType); if (filler) EmitInitializationToLValue(filler, elementLV); else EmitNullInitializationToLValue(elementLV); // Move on to the next element. llvm::Value *nextElement = Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next"); // Tell the EH cleanup that we finished with the last element. if (endOfInit) Builder.CreateStore(nextElement, endOfInit); // Leave the loop if we're done. llvm::Value *done = Builder.CreateICmpEQ(nextElement, end, "arrayinit.done"); llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end"); Builder.CreateCondBr(done, endBB, bodyBB); currentElement->addIncoming(nextElement, Builder.GetInsertBlock()); CGF.EmitBlock(endBB); } // Leave the partial-array cleanup if we entered one. if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator); } //===----------------------------------------------------------------------===// // Visitor Methods //===----------------------------------------------------------------------===// void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){ Visit(E->GetTemporaryExpr()); } void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) { EmitFinalDestCopy(e->getType(), CGF.getOpaqueLValueMapping(e)); } void AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { if (Dest.isPotentiallyAliased() && E->getType().isPODType(CGF.getContext())) { // For a POD type, just emit a load of the lvalue + a copy, because our // compound literal might alias the destination. EmitAggLoadOfLValue(E); return; } AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitAggExpr(E->getInitializer(), Slot); } /// Attempt to look through various unimportant expressions to find a /// cast of the given kind. static Expr *findPeephole(Expr *op, CastKind kind) { while (true) { op = op->IgnoreParens(); if (CastExpr *castE = dyn_cast(op)) { if (castE->getCastKind() == kind) return castE->getSubExpr(); if (castE->getCastKind() == CK_NoOp) continue; } return 0; } } void AggExprEmitter::VisitCastExpr(CastExpr *E) { switch (E->getCastKind()) { case CK_Dynamic: { // FIXME: Can this actually happen? We have no test coverage for it. assert(isa(E) && "CK_Dynamic without a dynamic_cast?"); LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(), CodeGenFunction::TCK_Load); // FIXME: Do we also need to handle property references here? if (LV.isSimple()) CGF.EmitDynamicCast(LV.getAddress(), cast(E)); else CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast"); if (!Dest.isIgnored()) CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination"); break; } case CK_ToUnion: { if (Dest.isIgnored()) break; // GCC union extension QualType Ty = E->getSubExpr()->getType(); QualType PtrTy = CGF.getContext().getPointerType(Ty); llvm::Value *CastPtr = Builder.CreateBitCast(Dest.getAddr(), CGF.ConvertType(PtrTy)); EmitInitializationToLValue(E->getSubExpr(), CGF.MakeAddrLValue(CastPtr, Ty)); break; } case CK_DerivedToBase: case CK_BaseToDerived: case CK_UncheckedDerivedToBase: { llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: " "should have been unpacked before we got here"); } case CK_NonAtomicToAtomic: case CK_AtomicToNonAtomic: { bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic); // Determine the atomic and value types. QualType atomicType = E->getSubExpr()->getType(); QualType valueType = E->getType(); if (isToAtomic) std::swap(atomicType, valueType); assert(atomicType->isAtomicType()); assert(CGF.getContext().hasSameUnqualifiedType(valueType, atomicType->castAs()->getValueType())); // Just recurse normally if we're ignoring the result or the // atomic type doesn't change representation. if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) { return Visit(E->getSubExpr()); } CastKind peepholeTarget = (isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic); // These two cases are reverses of each other; try to peephole them. if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) { assert(CGF.getContext().hasSameUnqualifiedType(op->getType(), E->getType()) && "peephole significantly changed types?"); return Visit(op); } // If we're converting an r-value of non-atomic type to an r-value // of atomic type, just emit directly into the relevant sub-object. if (isToAtomic) { AggValueSlot valueDest = Dest; if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) { // Zero-initialize. (Strictly speaking, we only need to intialize // the padding at the end, but this is simpler.) if (!Dest.isZeroed()) CGF.EmitNullInitialization(Dest.getAddr(), atomicType); // Build a GEP to refer to the subobject. llvm::Value *valueAddr = CGF.Builder.CreateStructGEP(valueDest.getAddr(), 0); valueDest = AggValueSlot::forAddr(valueAddr, valueDest.getAlignment(), valueDest.getQualifiers(), valueDest.isExternallyDestructed(), valueDest.requiresGCollection(), valueDest.isPotentiallyAliased(), AggValueSlot::IsZeroed); } CGF.EmitAggExpr(E->getSubExpr(), valueDest); return; } // Otherwise, we're converting an atomic type to a non-atomic type. // Make an atomic temporary, emit into that, and then copy the value out. AggValueSlot atomicSlot = CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp"); CGF.EmitAggExpr(E->getSubExpr(), atomicSlot); llvm::Value *valueAddr = Builder.CreateStructGEP(atomicSlot.getAddr(), 0); RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile()); return EmitFinalDestCopy(valueType, rvalue); } case CK_LValueToRValue: // If we're loading from a volatile type, force the destination // into existence. if (E->getSubExpr()->getType().isVolatileQualified()) { EnsureDest(E->getType()); return Visit(E->getSubExpr()); } // fallthrough case CK_NoOp: case CK_UserDefinedConversion: case CK_ConstructorConversion: assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(), E->getType()) && "Implicit cast types must be compatible"); Visit(E->getSubExpr()); break; case CK_LValueBitCast: llvm_unreachable("should not be emitting lvalue bitcast as rvalue"); case CK_Dependent: case CK_BitCast: case CK_ArrayToPointerDecay: case CK_FunctionToPointerDecay: case CK_NullToPointer: case CK_NullToMemberPointer: case CK_BaseToDerivedMemberPointer: case CK_DerivedToBaseMemberPointer: case CK_MemberPointerToBoolean: case CK_ReinterpretMemberPointer: case CK_IntegralToPointer: case CK_PointerToIntegral: case CK_PointerToBoolean: case CK_ToVoid: case CK_VectorSplat: case CK_IntegralCast: case CK_IntegralToBoolean: case CK_IntegralToFloating: case CK_FloatingToIntegral: case CK_FloatingToBoolean: case CK_FloatingCast: case CK_CPointerToObjCPointerCast: case CK_BlockPointerToObjCPointerCast: case CK_AnyPointerToBlockPointerCast: case CK_ObjCObjectLValueCast: case CK_FloatingRealToComplex: case CK_FloatingComplexToReal: case CK_FloatingComplexToBoolean: case CK_FloatingComplexCast: case CK_FloatingComplexToIntegralComplex: case CK_IntegralRealToComplex: case CK_IntegralComplexToReal: case CK_IntegralComplexToBoolean: case CK_IntegralComplexCast: case CK_IntegralComplexToFloatingComplex: case CK_ARCProduceObject: case CK_ARCConsumeObject: case CK_ARCReclaimReturnedObject: case CK_ARCExtendBlockObject: case CK_CopyAndAutoreleaseBlockObject: case CK_BuiltinFnToFnPtr: case CK_ZeroToOCLEvent: case CK_AddressSpaceConversion: llvm_unreachable("cast kind invalid for aggregate types"); } } void AggExprEmitter::VisitCallExpr(const CallExpr *E) { if (E->getCallReturnType()->isReferenceType()) { EmitAggLoadOfLValue(E); return; } RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot()); EmitMoveFromReturnSlot(E, RV); } void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot()); EmitMoveFromReturnSlot(E, RV); } void AggExprEmitter::VisitBinComma(const BinaryOperator *E) { CGF.EmitIgnoredExpr(E->getLHS()); Visit(E->getRHS()); } void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) { CodeGenFunction::StmtExprEvaluation eval(CGF); CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest); } void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) { if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI) VisitPointerToDataMemberBinaryOperator(E); else CGF.ErrorUnsupported(E, "aggregate binary expression"); } void AggExprEmitter::VisitPointerToDataMemberBinaryOperator( const BinaryOperator *E) { LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E); EmitFinalDestCopy(E->getType(), LV); } /// Is the value of the given expression possibly a reference to or /// into a __block variable? static bool isBlockVarRef(const Expr *E) { // Make sure we look through parens. E = E->IgnoreParens(); // Check for a direct reference to a __block variable. if (const DeclRefExpr *DRE = dyn_cast(E)) { const VarDecl *var = dyn_cast(DRE->getDecl()); return (var && var->hasAttr()); } // More complicated stuff. // Binary operators. if (const BinaryOperator *op = dyn_cast(E)) { // For an assignment or pointer-to-member operation, just care // about the LHS. if (op->isAssignmentOp() || op->isPtrMemOp()) return isBlockVarRef(op->getLHS()); // For a comma, just care about the RHS. if (op->getOpcode() == BO_Comma) return isBlockVarRef(op->getRHS()); // FIXME: pointer arithmetic? return false; // Check both sides of a conditional operator. } else if (const AbstractConditionalOperator *op = dyn_cast(E)) { return isBlockVarRef(op->getTrueExpr()) || isBlockVarRef(op->getFalseExpr()); // OVEs are required to support BinaryConditionalOperators. } else if (const OpaqueValueExpr *op = dyn_cast(E)) { if (const Expr *src = op->getSourceExpr()) return isBlockVarRef(src); // Casts are necessary to get things like (*(int*)&var) = foo(). // We don't really care about the kind of cast here, except // we don't want to look through l2r casts, because it's okay // to get the *value* in a __block variable. } else if (const CastExpr *cast = dyn_cast(E)) { if (cast->getCastKind() == CK_LValueToRValue) return false; return isBlockVarRef(cast->getSubExpr()); // Handle unary operators. Again, just aggressively look through // it, ignoring the operation. } else if (const UnaryOperator *uop = dyn_cast(E)) { return isBlockVarRef(uop->getSubExpr()); // Look into the base of a field access. } else if (const MemberExpr *mem = dyn_cast(E)) { return isBlockVarRef(mem->getBase()); // Look into the base of a subscript. } else if (const ArraySubscriptExpr *sub = dyn_cast(E)) { return isBlockVarRef(sub->getBase()); } return false; } void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) { // For an assignment to work, the value on the right has // to be compatible with the value on the left. assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(), E->getRHS()->getType()) && "Invalid assignment"); // If the LHS might be a __block variable, and the RHS can // potentially cause a block copy, we need to evaluate the RHS first // so that the assignment goes the right place. // This is pretty semantically fragile. if (isBlockVarRef(E->getLHS()) && E->getRHS()->HasSideEffects(CGF.getContext())) { // Ensure that we have a destination, and evaluate the RHS into that. EnsureDest(E->getRHS()->getType()); Visit(E->getRHS()); // Now emit the LHS and copy into it. LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); // That copy is an atomic copy if the LHS is atomic. if (LHS.getType()->isAtomicType()) { CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); return; } EmitCopy(E->getLHS()->getType(), AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()), AggValueSlot::IsAliased), Dest); return; } LValue LHS = CGF.EmitLValue(E->getLHS()); // If we have an atomic type, evaluate into the destination and then // do an atomic copy. if (LHS.getType()->isAtomicType()) { EnsureDest(E->getRHS()->getType()); Visit(E->getRHS()); CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); return; } // Codegen the RHS so that it stores directly into the LHS. AggValueSlot LHSSlot = AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, needsGC(E->getLHS()->getType()), AggValueSlot::IsAliased); // A non-volatile aggregate destination might have volatile member. if (!LHSSlot.isVolatile() && CGF.hasVolatileMember(E->getLHS()->getType())) LHSSlot.setVolatile(true); CGF.EmitAggExpr(E->getRHS(), LHSSlot); // Copy into the destination if the assignment isn't ignored. EmitFinalDestCopy(E->getType(), LHS); } void AggExprEmitter:: VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); // Bind the common expression if necessary. CodeGenFunction::OpaqueValueMapping binding(CGF, E); RegionCounter Cnt = CGF.getPGORegionCounter(E); CodeGenFunction::ConditionalEvaluation eval(CGF); CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, Cnt.getCount()); // Save whether the destination's lifetime is externally managed. bool isExternallyDestructed = Dest.isExternallyDestructed(); eval.begin(CGF); CGF.EmitBlock(LHSBlock); Cnt.beginRegion(Builder); Visit(E->getTrueExpr()); eval.end(CGF); assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!"); CGF.Builder.CreateBr(ContBlock); // If the result of an agg expression is unused, then the emission // of the LHS might need to create a destination slot. That's fine // with us, and we can safely emit the RHS into the same slot, but // we shouldn't claim that it's already being destructed. Dest.setExternallyDestructed(isExternallyDestructed); eval.begin(CGF); CGF.EmitBlock(RHSBlock); Visit(E->getFalseExpr()); eval.end(CGF); CGF.EmitBlock(ContBlock); } void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) { Visit(CE->getChosenSubExpr()); } void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); if (!ArgPtr) { // If EmitVAArg fails, we fall back to the LLVM instruction. llvm::Value *Val = Builder.CreateVAArg(ArgValue, CGF.ConvertType(VE->getType())); if (!Dest.isIgnored()) Builder.CreateStore(Val, Dest.getAddr()); return; } EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType())); } void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { // Ensure that we have a slot, but if we already do, remember // whether it was externally destructed. bool wasExternallyDestructed = Dest.isExternallyDestructed(); EnsureDest(E->getType()); // We're going to push a destructor if there isn't already one. Dest.setExternallyDestructed(); Visit(E->getSubExpr()); // Push that destructor we promised. if (!wasExternallyDestructed) CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddr()); } void AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitCXXConstructExpr(E, Slot); } void AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) { AggValueSlot Slot = EnsureSlot(E->getType()); CGF.EmitLambdaExpr(E, Slot); } void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) { CGF.enterFullExpression(E); CodeGenFunction::RunCleanupsScope cleanups(CGF); Visit(E->getSubExpr()); } void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) { QualType T = E->getType(); AggValueSlot Slot = EnsureSlot(T); EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T)); } void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) { QualType T = E->getType(); AggValueSlot Slot = EnsureSlot(T); EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T)); } /// isSimpleZero - If emitting this value will obviously just cause a store of /// zero to memory, return true. This can return false if uncertain, so it just /// handles simple cases. static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) { E = E->IgnoreParens(); // 0 if (const IntegerLiteral *IL = dyn_cast(E)) return IL->getValue() == 0; // +0.0 if (const FloatingLiteral *FL = dyn_cast(E)) return FL->getValue().isPosZero(); // int() if ((isa(E) || isa(E)) && CGF.getTypes().isZeroInitializable(E->getType())) return true; // (int*)0 - Null pointer expressions. if (const CastExpr *ICE = dyn_cast(E)) return ICE->getCastKind() == CK_NullToPointer; // '\0' if (const CharacterLiteral *CL = dyn_cast(E)) return CL->getValue() == 0; // Otherwise, hard case: conservatively return false. return false; } void AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) { QualType type = LV.getType(); // FIXME: Ignore result? // FIXME: Are initializers affected by volatile? if (Dest.isZeroed() && isSimpleZero(E, CGF)) { // Storing "i32 0" to a zero'd memory location is a noop. return; } else if (isa(E) || isa(E)) { return EmitNullInitializationToLValue(LV); } else if (type->isReferenceType()) { RValue RV = CGF.EmitReferenceBindingToExpr(E); return CGF.EmitStoreThroughLValue(RV, LV); } switch (CGF.getEvaluationKind(type)) { case TEK_Complex: CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true); return; case TEK_Aggregate: CGF.EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased, Dest.isZeroed())); return; case TEK_Scalar: if (LV.isSimple()) { CGF.EmitScalarInit(E, /*D=*/0, LV, /*Captured=*/false); } else { CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV); } return; } llvm_unreachable("bad evaluation kind"); } void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) { QualType type = lv.getType(); // If the destination slot is already zeroed out before the aggregate is // copied into it, we don't have to emit any zeros here. if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type)) return; if (CGF.hasScalarEvaluationKind(type)) { // For non-aggregates, we can store the appropriate null constant. llvm::Value *null = CGF.CGM.EmitNullConstant(type); // Note that the following is not equivalent to // EmitStoreThroughBitfieldLValue for ARC types. if (lv.isBitField()) { CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv); } else { assert(lv.isSimple()); CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true); } } else { // There's a potential optimization opportunity in combining // memsets; that would be easy for arrays, but relatively // difficult for structures with the current code. CGF.EmitNullInitialization(lv.getAddress(), lv.getType()); } } void AggExprEmitter::VisitInitListExpr(InitListExpr *E) { #if 0 // FIXME: Assess perf here? Figure out what cases are worth optimizing here // (Length of globals? Chunks of zeroed-out space?). // // If we can, prefer a copy from a global; this is a lot less code for long // globals, and it's easier for the current optimizers to analyze. if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) { llvm::GlobalVariable* GV = new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true, llvm::GlobalValue::InternalLinkage, C, ""); EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType())); return; } #endif if (E->hadArrayRangeDesignator()) CGF.ErrorUnsupported(E, "GNU array range designator extension"); AggValueSlot Dest = EnsureSlot(E->getType()); LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(), Dest.getAlignment()); // Handle initialization of an array. if (E->getType()->isArrayType()) { if (E->isStringLiteralInit()) return Visit(E->getInit(0)); QualType elementType = CGF.getContext().getAsArrayType(E->getType())->getElementType(); llvm::PointerType *APType = cast(Dest.getAddr()->getType()); llvm::ArrayType *AType = cast(APType->getElementType()); EmitArrayInit(Dest.getAddr(), AType, elementType, E); return; } assert(E->getType()->isRecordType() && "Only support structs/unions here!"); // Do struct initialization; this code just sets each individual member // to the approprate value. This makes bitfield support automatic; // the disadvantage is that the generated code is more difficult for // the optimizer, especially with bitfields. unsigned NumInitElements = E->getNumInits(); RecordDecl *record = E->getType()->castAs()->getDecl(); // Prepare a 'this' for CXXDefaultInitExprs. CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddr()); if (record->isUnion()) { // Only initialize one field of a union. The field itself is // specified by the initializer list. if (!E->getInitializedFieldInUnion()) { // Empty union; we have nothing to do. #ifndef NDEBUG // Make sure that it's really an empty and not a failure of // semantic analysis. for (RecordDecl::field_iterator Field = record->field_begin(), FieldEnd = record->field_end(); Field != FieldEnd; ++Field) assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed"); #endif return; } // FIXME: volatility FieldDecl *Field = E->getInitializedFieldInUnion(); LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field); if (NumInitElements) { // Store the initializer into the field EmitInitializationToLValue(E->getInit(0), FieldLoc); } else { // Default-initialize to null. EmitNullInitializationToLValue(FieldLoc); } return; } // We'll need to enter cleanup scopes in case any of the member // initializers throw an exception. SmallVector cleanups; llvm::Instruction *cleanupDominator = 0; // Here we iterate over the fields; this makes it simpler to both // default-initialize fields and skip over unnamed fields. unsigned curInitIndex = 0; for (RecordDecl::field_iterator field = record->field_begin(), fieldEnd = record->field_end(); field != fieldEnd; ++field) { // We're done once we hit the flexible array member. if (field->getType()->isIncompleteArrayType()) break; // Always skip anonymous bitfields. if (field->isUnnamedBitfield()) continue; // We're done if we reach the end of the explicit initializers, we // have a zeroed object, and the rest of the fields are // zero-initializable. if (curInitIndex == NumInitElements && Dest.isZeroed() && CGF.getTypes().isZeroInitializable(E->getType())) break; LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, *field); // We never generate write-barries for initialized fields. LV.setNonGC(true); if (curInitIndex < NumInitElements) { // Store the initializer into the field. EmitInitializationToLValue(E->getInit(curInitIndex++), LV); } else { // We're out of initalizers; default-initialize to null EmitNullInitializationToLValue(LV); } // Push a destructor if necessary. // FIXME: if we have an array of structures, all explicitly // initialized, we can end up pushing a linear number of cleanups. bool pushedCleanup = false; if (QualType::DestructionKind dtorKind = field->getType().isDestructedType()) { assert(LV.isSimple()); if (CGF.needsEHCleanup(dtorKind)) { if (!cleanupDominator) cleanupDominator = CGF.Builder.CreateUnreachable(); // placeholder CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(), CGF.getDestroyer(dtorKind), false); cleanups.push_back(CGF.EHStack.stable_begin()); pushedCleanup = true; } } // If the GEP didn't get used because of a dead zero init or something // else, clean it up for -O0 builds and general tidiness. if (!pushedCleanup && LV.isSimple()) if (llvm::GetElementPtrInst *GEP = dyn_cast(LV.getAddress())) if (GEP->use_empty()) GEP->eraseFromParent(); } // Deactivate all the partial cleanups in reverse order, which // generally means popping them. for (unsigned i = cleanups.size(); i != 0; --i) CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator); // Destroy the placeholder if we made one. if (cleanupDominator) cleanupDominator->eraseFromParent(); } //===----------------------------------------------------------------------===// // Entry Points into this File //===----------------------------------------------------------------------===// /// GetNumNonZeroBytesInInit - Get an approximate count of the number of /// non-zero bytes that will be stored when outputting the initializer for the /// specified initializer expression. static CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF) { E = E->IgnoreParens(); // 0 and 0.0 won't require any non-zero stores! if (isSimpleZero(E, CGF)) return CharUnits::Zero(); // If this is an initlist expr, sum up the size of sizes of the (present) // elements. If this is something weird, assume the whole thing is non-zero. const InitListExpr *ILE = dyn_cast(E); if (ILE == 0 || !CGF.getTypes().isZeroInitializable(ILE->getType())) return CGF.getContext().getTypeSizeInChars(E->getType()); // InitListExprs for structs have to be handled carefully. If there are // reference members, we need to consider the size of the reference, not the // referencee. InitListExprs for unions and arrays can't have references. if (const RecordType *RT = E->getType()->getAs()) { if (!RT->isUnionType()) { RecordDecl *SD = E->getType()->getAs()->getDecl(); CharUnits NumNonZeroBytes = CharUnits::Zero(); unsigned ILEElement = 0; for (RecordDecl::field_iterator Field = SD->field_begin(), FieldEnd = SD->field_end(); Field != FieldEnd; ++Field) { // We're done once we hit the flexible array member or run out of // InitListExpr elements. if (Field->getType()->isIncompleteArrayType() || ILEElement == ILE->getNumInits()) break; if (Field->isUnnamedBitfield()) continue; const Expr *E = ILE->getInit(ILEElement++); // Reference values are always non-null and have the width of a pointer. if (Field->getType()->isReferenceType()) NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits( CGF.getTarget().getPointerWidth(0)); else NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF); } return NumNonZeroBytes; } } CharUnits NumNonZeroBytes = CharUnits::Zero(); for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF); return NumNonZeroBytes; } /// CheckAggExprForMemSetUse - If the initializer is large and has a lot of /// zeros in it, emit a memset and avoid storing the individual zeros. /// static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E, CodeGenFunction &CGF) { // If the slot is already known to be zeroed, nothing to do. Don't mess with // volatile stores. if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == 0) return; // C++ objects with a user-declared constructor don't need zero'ing. if (CGF.getLangOpts().CPlusPlus) if (const RecordType *RT = CGF.getContext() .getBaseElementType(E->getType())->getAs()) { const CXXRecordDecl *RD = cast(RT->getDecl()); if (RD->hasUserDeclaredConstructor()) return; } // If the type is 16-bytes or smaller, prefer individual stores over memset. std::pair TypeInfo = CGF.getContext().getTypeInfoInChars(E->getType()); if (TypeInfo.first <= CharUnits::fromQuantity(16)) return; // Check to see if over 3/4 of the initializer are known to be zero. If so, // we prefer to emit memset + individual stores for the rest. CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF); if (NumNonZeroBytes*4 > TypeInfo.first) return; // Okay, it seems like a good idea to use an initial memset, emit the call. llvm::Constant *SizeVal = CGF.Builder.getInt64(TypeInfo.first.getQuantity()); CharUnits Align = TypeInfo.second; llvm::Value *Loc = Slot.getAddr(); Loc = CGF.Builder.CreateBitCast(Loc, CGF.Int8PtrTy); CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, Align.getQuantity(), false); // Tell the AggExprEmitter that the slot is known zero. Slot.setZeroed(); } /// EmitAggExpr - Emit the computation of the specified expression of aggregate /// type. The result is computed into DestPtr. Note that if DestPtr is null, /// the value of the aggregate expression is not needed. If VolatileDest is /// true, DestPtr cannot be 0. void CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot) { assert(E && hasAggregateEvaluationKind(E->getType()) && "Invalid aggregate expression to emit"); assert((Slot.getAddr() != 0 || Slot.isIgnored()) && "slot has bits but no address"); // Optimize the slot if possible. CheckAggExprForMemSetUse(Slot, E, *this); AggExprEmitter(*this, Slot).Visit(const_cast(E)); } LValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) { assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!"); llvm::Value *Temp = CreateMemTemp(E->getType()); LValue LV = MakeAddrLValue(Temp, E->getType()); EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased)); return LV; } void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr, llvm::Value *SrcPtr, QualType Ty, bool isVolatile, CharUnits alignment, bool isAssignment) { assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); if (getLangOpts().CPlusPlus) { if (const RecordType *RT = Ty->getAs()) { CXXRecordDecl *Record = cast(RT->getDecl()); assert((Record->hasTrivialCopyConstructor() || Record->hasTrivialCopyAssignment() || Record->hasTrivialMoveConstructor() || Record->hasTrivialMoveAssignment()) && "Trying to aggregate-copy a type without a trivial copy/move " "constructor or assignment operator"); // Ignore empty classes in C++. if (Record->isEmpty()) return; } } // Aggregate assignment turns into llvm.memcpy. This is almost valid per // C99 6.5.16.1p3, which states "If the value being stored in an object is // read from another object that overlaps in anyway the storage of the first // object, then the overlap shall be exact and the two objects shall have // qualified or unqualified versions of a compatible type." // // memcpy is not defined if the source and destination pointers are exactly // equal, but other compilers do this optimization, and almost every memcpy // implementation handles this case safely. If there is a libc that does not // safely handle this, we can add a target hook. // Get data size and alignment info for this aggregate. If this is an // assignment don't copy the tail padding. Otherwise copying it is fine. std::pair TypeInfo; if (isAssignment) TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty); else TypeInfo = getContext().getTypeInfoInChars(Ty); if (alignment.isZero()) alignment = TypeInfo.second; // FIXME: Handle variable sized types. // FIXME: If we have a volatile struct, the optimizer can remove what might // appear to be `extra' memory ops: // // volatile struct { int i; } a, b; // // int main() { // a = b; // a = b; // } // // we need to use a different call here. We use isVolatile to indicate when // either the source or the destination is volatile. llvm::PointerType *DPT = cast(DestPtr->getType()); llvm::Type *DBP = llvm::Type::getInt8PtrTy(getLLVMContext(), DPT->getAddressSpace()); DestPtr = Builder.CreateBitCast(DestPtr, DBP); llvm::PointerType *SPT = cast(SrcPtr->getType()); llvm::Type *SBP = llvm::Type::getInt8PtrTy(getLLVMContext(), SPT->getAddressSpace()); SrcPtr = Builder.CreateBitCast(SrcPtr, SBP); // Don't do any of the memmove_collectable tests if GC isn't set. if (CGM.getLangOpts().getGC() == LangOptions::NonGC) { // fall through } else if (const RecordType *RecordTy = Ty->getAs()) { RecordDecl *Record = RecordTy->getDecl(); if (Record->hasObjectMember()) { CharUnits size = TypeInfo.first; llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity()); CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, SizeVal); return; } } else if (Ty->isArrayType()) { QualType BaseType = getContext().getBaseElementType(Ty); if (const RecordType *RecordTy = BaseType->getAs()) { if (RecordTy->getDecl()->hasObjectMember()) { CharUnits size = TypeInfo.first; llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity()); CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, SizeVal); return; } } } // Determine the metadata to describe the position of any padding in this // memcpy, as well as the TBAA tags for the members of the struct, in case // the optimizer wishes to expand it in to scalar memory operations. llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty); Builder.CreateMemCpy(DestPtr, SrcPtr, llvm::ConstantInt::get(IntPtrTy, TypeInfo.first.getQuantity()), alignment.getQuantity(), isVolatile, /*TBAATag=*/0, TBAAStructTag); } @