//===--- CGExpr.cpp - Emit LLVM Code from 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 Expr nodes as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "CGCall.h" #include "CGCXXABI.h" #include "CGDebugInfo.h" #include "CGRecordLayout.h" #include "CGObjCRuntime.h" #include "TargetInfo.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "clang/Frontend/CodeGenOptions.h" #include "llvm/Intrinsics.h" #include "llvm/LLVMContext.h" #include "llvm/Support/MDBuilder.h" #include "llvm/Target/TargetData.h" using namespace clang; using namespace CodeGen; //===--------------------------------------------------------------------===// // Miscellaneous Helper Methods //===--------------------------------------------------------------------===// llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) { unsigned addressSpace = cast(value->getType())->getAddressSpace(); llvm::PointerType *destType = Int8PtrTy; if (addressSpace) destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace); if (value->getType() == destType) return value; return Builder.CreateBitCast(value, destType); } /// CreateTempAlloca - This creates a alloca and inserts it into the entry /// block. llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, const Twine &Name) { if (!Builder.isNamePreserving()) return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt); return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt); } void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var, llvm::Value *Init) { llvm::StoreInst *Store = new llvm::StoreInst(Init, Var); llvm::BasicBlock *Block = AllocaInsertPt->getParent(); Block->getInstList().insertAfter(&*AllocaInsertPt, Store); } llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) { llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name); // FIXME: Should we prefer the preferred type alignment here? CharUnits Align = getContext().getTypeAlignInChars(Ty); Alloc->setAlignment(Align.getQuantity()); return Alloc; } llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name) { llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name); // FIXME: Should we prefer the preferred type alignment here? CharUnits Align = getContext().getTypeAlignInChars(Ty); Alloc->setAlignment(Align.getQuantity()); return Alloc; } /// EvaluateExprAsBool - Perform the usual unary conversions on the specified /// expression and compare the result against zero, returning an Int1Ty value. llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) { if (const MemberPointerType *MPT = E->getType()->getAs()) { llvm::Value *MemPtr = EmitScalarExpr(E); return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT); } QualType BoolTy = getContext().BoolTy; if (!E->getType()->isAnyComplexType()) return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy); return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy); } /// EmitIgnoredExpr - Emit code to compute the specified expression, /// ignoring the result. void CodeGenFunction::EmitIgnoredExpr(const Expr *E) { if (E->isRValue()) return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true); // Just emit it as an l-value and drop the result. EmitLValue(E); } /// EmitAnyExpr - Emit code to compute the specified expression which /// can have any type. The result is returned as an RValue struct. /// If this is an aggregate expression, AggSlot indicates where the /// result should be returned. RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot, bool IgnoreResult) { if (!hasAggregateLLVMType(E->getType())) return RValue::get(EmitScalarExpr(E, IgnoreResult)); else if (E->getType()->isAnyComplexType()) return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult)); EmitAggExpr(E, AggSlot, IgnoreResult); return AggSlot.asRValue(); } /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will /// always be accessible even if no aggregate location is provided. RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) { AggValueSlot AggSlot = AggValueSlot::ignored(); if (hasAggregateLLVMType(E->getType()) && !E->getType()->isAnyComplexType()) AggSlot = CreateAggTemp(E->getType(), "agg.tmp"); return EmitAnyExpr(E, AggSlot); } /// EmitAnyExprToMem - Evaluate an expression into a given memory /// location. void CodeGenFunction::EmitAnyExprToMem(const Expr *E, llvm::Value *Location, Qualifiers Quals, bool IsInit) { // FIXME: This function should take an LValue as an argument. if (E->getType()->isAnyComplexType()) { EmitComplexExprIntoAddr(E, Location, Quals.hasVolatile()); } else if (hasAggregateLLVMType(E->getType())) { CharUnits Alignment = getContext().getTypeAlignInChars(E->getType()); EmitAggExpr(E, AggValueSlot::forAddr(Location, Alignment, Quals, AggValueSlot::IsDestructed_t(IsInit), AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsAliased_t(!IsInit))); } else { RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false)); LValue LV = MakeAddrLValue(Location, E->getType()); EmitStoreThroughLValue(RV, LV); } } namespace { /// \brief An adjustment to be made to the temporary created when emitting a /// reference binding, which accesses a particular subobject of that temporary. struct SubobjectAdjustment { enum { DerivedToBaseAdjustment, FieldAdjustment } Kind; union { struct { const CastExpr *BasePath; const CXXRecordDecl *DerivedClass; } DerivedToBase; FieldDecl *Field; }; SubobjectAdjustment(const CastExpr *BasePath, const CXXRecordDecl *DerivedClass) : Kind(DerivedToBaseAdjustment) { DerivedToBase.BasePath = BasePath; DerivedToBase.DerivedClass = DerivedClass; } SubobjectAdjustment(FieldDecl *Field) : Kind(FieldAdjustment) { this->Field = Field; } }; } static llvm::Value * CreateReferenceTemporary(CodeGenFunction &CGF, QualType Type, const NamedDecl *InitializedDecl) { if (const VarDecl *VD = dyn_cast_or_null(InitializedDecl)) { if (VD->hasGlobalStorage()) { SmallString<256> Name; llvm::raw_svector_ostream Out(Name); CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out); Out.flush(); llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type); // Create the reference temporary. llvm::GlobalValue *RefTemp = new llvm::GlobalVariable(CGF.CGM.getModule(), RefTempTy, /*isConstant=*/false, llvm::GlobalValue::InternalLinkage, llvm::Constant::getNullValue(RefTempTy), Name.str()); return RefTemp; } } return CGF.CreateMemTemp(Type, "ref.tmp"); } static llvm::Value * EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E, llvm::Value *&ReferenceTemporary, const CXXDestructorDecl *&ReferenceTemporaryDtor, QualType &ObjCARCReferenceLifetimeType, const NamedDecl *InitializedDecl) { // Look through single-element init lists that claim to be lvalues. They're // just syntactic wrappers in this case. if (const InitListExpr *ILE = dyn_cast(E)) { if (ILE->getNumInits() == 1 && ILE->isGLValue()) E = ILE->getInit(0); } // Look through expressions for materialized temporaries (for now). if (const MaterializeTemporaryExpr *M = dyn_cast(E)) { // Objective-C++ ARC: // If we are binding a reference to a temporary that has ownership, we // need to perform retain/release operations on the temporary. if (CGF.getContext().getLangOpts().ObjCAutoRefCount && E->getType()->isObjCLifetimeType() && (E->getType().getObjCLifetime() == Qualifiers::OCL_Strong || E->getType().getObjCLifetime() == Qualifiers::OCL_Weak || E->getType().getObjCLifetime() == Qualifiers::OCL_Autoreleasing)) ObjCARCReferenceLifetimeType = E->getType(); E = M->GetTemporaryExpr(); } if (const CXXDefaultArgExpr *DAE = dyn_cast(E)) E = DAE->getExpr(); if (const ExprWithCleanups *EWC = dyn_cast(E)) { CGF.enterFullExpression(EWC); CodeGenFunction::RunCleanupsScope Scope(CGF); return EmitExprForReferenceBinding(CGF, EWC->getSubExpr(), ReferenceTemporary, ReferenceTemporaryDtor, ObjCARCReferenceLifetimeType, InitializedDecl); } RValue RV; if (E->isGLValue()) { // Emit the expression as an lvalue. LValue LV = CGF.EmitLValue(E); if (LV.isSimple()) return LV.getAddress(); // We have to load the lvalue. RV = CGF.EmitLoadOfLValue(LV); } else { if (!ObjCARCReferenceLifetimeType.isNull()) { ReferenceTemporary = CreateReferenceTemporary(CGF, ObjCARCReferenceLifetimeType, InitializedDecl); LValue RefTempDst = CGF.MakeAddrLValue(ReferenceTemporary, ObjCARCReferenceLifetimeType); CGF.EmitScalarInit(E, dyn_cast_or_null(InitializedDecl), RefTempDst, false); bool ExtendsLifeOfTemporary = false; if (const VarDecl *Var = dyn_cast_or_null(InitializedDecl)) { if (Var->extendsLifetimeOfTemporary()) ExtendsLifeOfTemporary = true; } else if (InitializedDecl && isa(InitializedDecl)) { ExtendsLifeOfTemporary = true; } if (!ExtendsLifeOfTemporary) { // Since the lifetime of this temporary isn't going to be extended, // we need to clean it up ourselves at the end of the full expression. switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) { case Qualifiers::OCL_None: case Qualifiers::OCL_ExplicitNone: case Qualifiers::OCL_Autoreleasing: break; case Qualifiers::OCL_Strong: { assert(!ObjCARCReferenceLifetimeType->isArrayType()); CleanupKind cleanupKind = CGF.getARCCleanupKind(); CGF.pushDestroy(cleanupKind, ReferenceTemporary, ObjCARCReferenceLifetimeType, CodeGenFunction::destroyARCStrongImprecise, cleanupKind & EHCleanup); break; } case Qualifiers::OCL_Weak: assert(!ObjCARCReferenceLifetimeType->isArrayType()); CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, ObjCARCReferenceLifetimeType, CodeGenFunction::destroyARCWeak, /*useEHCleanupForArray*/ true); break; } ObjCARCReferenceLifetimeType = QualType(); } return ReferenceTemporary; } SmallVector Adjustments; while (true) { E = E->IgnoreParens(); if (const CastExpr *CE = dyn_cast(E)) { if ((CE->getCastKind() == CK_DerivedToBase || CE->getCastKind() == CK_UncheckedDerivedToBase) && E->getType()->isRecordType()) { E = CE->getSubExpr(); CXXRecordDecl *Derived = cast(E->getType()->getAs()->getDecl()); Adjustments.push_back(SubobjectAdjustment(CE, Derived)); continue; } if (CE->getCastKind() == CK_NoOp) { E = CE->getSubExpr(); continue; } } else if (const MemberExpr *ME = dyn_cast(E)) { if (!ME->isArrow() && ME->getBase()->isRValue()) { assert(ME->getBase()->getType()->isRecordType()); if (FieldDecl *Field = dyn_cast(ME->getMemberDecl())) { E = ME->getBase(); Adjustments.push_back(SubobjectAdjustment(Field)); continue; } } } if (const OpaqueValueExpr *opaque = dyn_cast(E)) if (opaque->getType()->isRecordType()) return CGF.EmitOpaqueValueLValue(opaque).getAddress(); // Nothing changed. break; } // Create a reference temporary if necessary. AggValueSlot AggSlot = AggValueSlot::ignored(); if (CGF.hasAggregateLLVMType(E->getType()) && !E->getType()->isAnyComplexType()) { ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(), InitializedDecl); CharUnits Alignment = CGF.getContext().getTypeAlignInChars(E->getType()); AggValueSlot::IsDestructed_t isDestructed = AggValueSlot::IsDestructed_t(InitializedDecl != 0); AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Alignment, Qualifiers(), isDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); } if (InitializedDecl) { // Get the destructor for the reference temporary. if (const RecordType *RT = E->getType()->getAs()) { CXXRecordDecl *ClassDecl = cast(RT->getDecl()); if (!ClassDecl->hasTrivialDestructor()) ReferenceTemporaryDtor = ClassDecl->getDestructor(); } } RV = CGF.EmitAnyExpr(E, AggSlot); // Check if need to perform derived-to-base casts and/or field accesses, to // get from the temporary object we created (and, potentially, for which we // extended the lifetime) to the subobject we're binding the reference to. if (!Adjustments.empty()) { llvm::Value *Object = RV.getAggregateAddr(); for (unsigned I = Adjustments.size(); I != 0; --I) { SubobjectAdjustment &Adjustment = Adjustments[I-1]; switch (Adjustment.Kind) { case SubobjectAdjustment::DerivedToBaseAdjustment: Object = CGF.GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass, Adjustment.DerivedToBase.BasePath->path_begin(), Adjustment.DerivedToBase.BasePath->path_end(), /*NullCheckValue=*/false); break; case SubobjectAdjustment::FieldAdjustment: { LValue LV = CGF.MakeAddrLValue(Object, E->getType()); LV = CGF.EmitLValueForField(LV, Adjustment.Field); if (LV.isSimple()) { Object = LV.getAddress(); break; } // For non-simple lvalues, we actually have to create a copy of // the object we're binding to. QualType T = Adjustment.Field->getType().getNonReferenceType() .getUnqualifiedType(); Object = CreateReferenceTemporary(CGF, T, InitializedDecl); LValue TempLV = CGF.MakeAddrLValue(Object, Adjustment.Field->getType()); CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV), TempLV); break; } } } return Object; } } if (RV.isAggregate()) return RV.getAggregateAddr(); // Create a temporary variable that we can bind the reference to. ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(), InitializedDecl); unsigned Alignment = CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity(); if (RV.isScalar()) CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary, /*Volatile=*/false, Alignment, E->getType()); else CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary, /*Volatile=*/false); return ReferenceTemporary; } RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E, const NamedDecl *InitializedDecl) { llvm::Value *ReferenceTemporary = 0; const CXXDestructorDecl *ReferenceTemporaryDtor = 0; QualType ObjCARCReferenceLifetimeType; llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary, ReferenceTemporaryDtor, ObjCARCReferenceLifetimeType, InitializedDecl); if (!ReferenceTemporaryDtor && ObjCARCReferenceLifetimeType.isNull()) return RValue::get(Value); // Make sure to call the destructor for the reference temporary. const VarDecl *VD = dyn_cast_or_null(InitializedDecl); if (VD && VD->hasGlobalStorage()) { if (ReferenceTemporaryDtor) { llvm::Constant *DtorFn = CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete); EmitCXXGlobalDtorRegistration(DtorFn, cast(ReferenceTemporary)); } else { assert(!ObjCARCReferenceLifetimeType.isNull()); // Note: We intentionally do not register a global "destructor" to // release the object. } return RValue::get(Value); } if (ReferenceTemporaryDtor) PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary); else { switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) { case Qualifiers::OCL_None: llvm_unreachable( "Not a reference temporary that needs to be deallocated"); case Qualifiers::OCL_ExplicitNone: case Qualifiers::OCL_Autoreleasing: // Nothing to do. break; case Qualifiers::OCL_Strong: { bool precise = VD && VD->hasAttr(); CleanupKind cleanupKind = getARCCleanupKind(); pushDestroy(cleanupKind, ReferenceTemporary, ObjCARCReferenceLifetimeType, precise ? destroyARCStrongPrecise : destroyARCStrongImprecise, cleanupKind & EHCleanup); break; } case Qualifiers::OCL_Weak: { // __weak objects always get EH cleanups; otherwise, exceptions // could cause really nasty crashes instead of mere leaks. pushDestroy(NormalAndEHCleanup, ReferenceTemporary, ObjCARCReferenceLifetimeType, destroyARCWeak, true); break; } } } return RValue::get(Value); } /// getAccessedFieldNo - Given an encoded value and a result number, return the /// input field number being accessed. unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts) { return cast(Elts->getAggregateElement(Idx)) ->getZExtValue(); } void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) { if (!CatchUndefined) return; // This needs to be to the standard address space. Address = Builder.CreateBitCast(Address, Int8PtrTy); llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, IntPtrTy); // In time, people may want to control this and use a 1 here. llvm::Value *Arg = Builder.getFalse(); llvm::Value *C = Builder.CreateCall2(F, Address, Arg); llvm::BasicBlock *Cont = createBasicBlock(); llvm::BasicBlock *Check = createBasicBlock(); llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL); Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check); EmitBlock(Check); Builder.CreateCondBr(Builder.CreateICmpUGE(C, llvm::ConstantInt::get(IntPtrTy, Size)), Cont, getTrapBB()); EmitBlock(Cont); } CodeGenFunction::ComplexPairTy CodeGenFunction:: EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV, bool isInc, bool isPre) { ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(), LV.isVolatileQualified()); llvm::Value *NextVal; if (isa(InVal.first->getType())) { uint64_t AmountVal = isInc ? 1 : -1; NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true); // Add the inc/dec to the real part. NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec"); } else { QualType ElemTy = E->getType()->getAs()->getElementType(); llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1); if (!isInc) FVal.changeSign(); NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal); // Add the inc/dec to the real part. NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec"); } ComplexPairTy IncVal(NextVal, InVal.second); // Store the updated result through the lvalue. StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified()); // If this is a postinc, return the value read from memory, otherwise use the // updated value. return isPre ? IncVal : InVal; } //===----------------------------------------------------------------------===// // LValue Expression Emission //===----------------------------------------------------------------------===// RValue CodeGenFunction::GetUndefRValue(QualType Ty) { if (Ty->isVoidType()) return RValue::get(0); if (const ComplexType *CTy = Ty->getAs()) { llvm::Type *EltTy = ConvertType(CTy->getElementType()); llvm::Value *U = llvm::UndefValue::get(EltTy); return RValue::getComplex(std::make_pair(U, U)); } // If this is a use of an undefined aggregate type, the aggregate must have an // identifiable address. Just because the contents of the value are undefined // doesn't mean that the address can't be taken and compared. if (hasAggregateLLVMType(Ty)) { llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp"); return RValue::getAggregate(DestPtr); } return RValue::get(llvm::UndefValue::get(ConvertType(Ty))); } RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E, const char *Name) { ErrorUnsupported(E, Name); return GetUndefRValue(E->getType()); } LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E, const char *Name) { ErrorUnsupported(E, Name); llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType())); return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType()); } LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) { LValue LV = EmitLValue(E); if (!isa(E) && !LV.isBitField() && LV.isSimple()) EmitCheck(LV.getAddress(), getContext().getTypeSizeInChars(E->getType()).getQuantity()); return LV; } /// EmitLValue - Emit code to compute a designator that specifies the location /// of the expression. /// /// This can return one of two things: a simple address or a bitfield reference. /// In either case, the LLVM Value* in the LValue structure is guaranteed to be /// an LLVM pointer type. /// /// If this returns a bitfield reference, nothing about the pointee type of the /// LLVM value is known: For example, it may not be a pointer to an integer. /// /// If this returns a normal address, and if the lvalue's C type is fixed size, /// this method guarantees that the returned pointer type will point to an LLVM /// type of the same size of the lvalue's type. If the lvalue has a variable /// length type, this is not possible. /// LValue CodeGenFunction::EmitLValue(const Expr *E) { switch (E->getStmtClass()) { default: return EmitUnsupportedLValue(E, "l-value expression"); case Expr::ObjCPropertyRefExprClass: llvm_unreachable("cannot emit a property reference directly"); case Expr::ObjCSelectorExprClass: return EmitObjCSelectorLValue(cast(E)); case Expr::ObjCIsaExprClass: return EmitObjCIsaExpr(cast(E)); case Expr::BinaryOperatorClass: return EmitBinaryOperatorLValue(cast(E)); case Expr::CompoundAssignOperatorClass: if (!E->getType()->isAnyComplexType()) return EmitCompoundAssignmentLValue(cast(E)); return EmitComplexCompoundAssignmentLValue(cast(E)); case Expr::CallExprClass: case Expr::CXXMemberCallExprClass: case Expr::CXXOperatorCallExprClass: case Expr::UserDefinedLiteralClass: return EmitCallExprLValue(cast(E)); case Expr::VAArgExprClass: return EmitVAArgExprLValue(cast(E)); case Expr::DeclRefExprClass: return EmitDeclRefLValue(cast(E)); case Expr::ParenExprClass: return EmitLValue(cast(E)->getSubExpr()); case Expr::GenericSelectionExprClass: return EmitLValue(cast(E)->getResultExpr()); case Expr::PredefinedExprClass: return EmitPredefinedLValue(cast(E)); case Expr::StringLiteralClass: return EmitStringLiteralLValue(cast(E)); case Expr::ObjCEncodeExprClass: return EmitObjCEncodeExprLValue(cast(E)); case Expr::PseudoObjectExprClass: return EmitPseudoObjectLValue(cast(E)); case Expr::InitListExprClass: assert(cast(E)->getNumInits() == 1 && "Only single-element init list can be lvalue."); return EmitLValue(cast(E)->getInit(0)); case Expr::CXXTemporaryObjectExprClass: case Expr::CXXConstructExprClass: return EmitCXXConstructLValue(cast(E)); case Expr::CXXBindTemporaryExprClass: return EmitCXXBindTemporaryLValue(cast(E)); case Expr::LambdaExprClass: return EmitLambdaLValue(cast(E)); case Expr::ExprWithCleanupsClass: { const ExprWithCleanups *cleanups = cast(E); enterFullExpression(cleanups); RunCleanupsScope Scope(*this); return EmitLValue(cleanups->getSubExpr()); } case Expr::CXXScalarValueInitExprClass: return EmitNullInitializationLValue(cast(E)); case Expr::CXXDefaultArgExprClass: return EmitLValue(cast(E)->getExpr()); case Expr::CXXTypeidExprClass: return EmitCXXTypeidLValue(cast(E)); case Expr::ObjCMessageExprClass: return EmitObjCMessageExprLValue(cast(E)); case Expr::ObjCIvarRefExprClass: return EmitObjCIvarRefLValue(cast(E)); case Expr::StmtExprClass: return EmitStmtExprLValue(cast(E)); case Expr::UnaryOperatorClass: return EmitUnaryOpLValue(cast(E)); case Expr::ArraySubscriptExprClass: return EmitArraySubscriptExpr(cast(E)); case Expr::ExtVectorElementExprClass: return EmitExtVectorElementExpr(cast(E)); case Expr::MemberExprClass: return EmitMemberExpr(cast(E)); case Expr::CompoundLiteralExprClass: return EmitCompoundLiteralLValue(cast(E)); case Expr::ConditionalOperatorClass: return EmitConditionalOperatorLValue(cast(E)); case Expr::BinaryConditionalOperatorClass: return EmitConditionalOperatorLValue(cast(E)); case Expr::ChooseExprClass: return EmitLValue(cast(E)->getChosenSubExpr(getContext())); case Expr::OpaqueValueExprClass: return EmitOpaqueValueLValue(cast(E)); case Expr::SubstNonTypeTemplateParmExprClass: return EmitLValue(cast(E)->getReplacement()); case Expr::ImplicitCastExprClass: case Expr::CStyleCastExprClass: case Expr::CXXFunctionalCastExprClass: case Expr::CXXStaticCastExprClass: case Expr::CXXDynamicCastExprClass: case Expr::CXXReinterpretCastExprClass: case Expr::CXXConstCastExprClass: case Expr::ObjCBridgedCastExprClass: return EmitCastLValue(cast(E)); case Expr::MaterializeTemporaryExprClass: return EmitMaterializeTemporaryExpr(cast(E)); } } /// Given an object of the given canonical type, can we safely copy a /// value out of it based on its initializer? static bool isConstantEmittableObjectType(QualType type) { assert(type.isCanonical()); assert(!type->isReferenceType()); // Must be const-qualified but non-volatile. Qualifiers qs = type.getLocalQualifiers(); if (!qs.hasConst() || qs.hasVolatile()) return false; // Otherwise, all object types satisfy this except C++ classes with // mutable subobjects or non-trivial copy/destroy behavior. if (const RecordType *RT = dyn_cast(type)) if (const CXXRecordDecl *RD = dyn_cast(RT->getDecl())) if (RD->hasMutableFields() || !RD->isTrivial()) return false; return true; } /// Can we constant-emit a load of a reference to a variable of the /// given type? This is different from predicates like /// Decl::isUsableInConstantExpressions because we do want it to apply /// in situations that don't necessarily satisfy the language's rules /// for this (e.g. C++'s ODR-use rules). For example, we want to able /// to do this with const float variables even if those variables /// aren't marked 'constexpr'. enum ConstantEmissionKind { CEK_None, CEK_AsReferenceOnly, CEK_AsValueOrReference, CEK_AsValueOnly }; static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) { type = type.getCanonicalType(); if (const ReferenceType *ref = dyn_cast(type)) { if (isConstantEmittableObjectType(ref->getPointeeType())) return CEK_AsValueOrReference; return CEK_AsReferenceOnly; } if (isConstantEmittableObjectType(type)) return CEK_AsValueOnly; return CEK_None; } /// Try to emit a reference to the given value without producing it as /// an l-value. This is actually more than an optimization: we can't /// produce an l-value for variables that we never actually captured /// in a block or lambda, which means const int variables or constexpr /// literals or similar. CodeGenFunction::ConstantEmission CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) { ValueDecl *value = refExpr->getDecl(); // The value needs to be an enum constant or a constant variable. ConstantEmissionKind CEK; if (isa(value)) { CEK = CEK_None; } else if (VarDecl *var = dyn_cast(value)) { CEK = checkVarTypeForConstantEmission(var->getType()); } else if (isa(value)) { CEK = CEK_AsValueOnly; } else { CEK = CEK_None; } if (CEK == CEK_None) return ConstantEmission(); Expr::EvalResult result; bool resultIsReference; QualType resultType; // It's best to evaluate all the way as an r-value if that's permitted. if (CEK != CEK_AsReferenceOnly && refExpr->EvaluateAsRValue(result, getContext())) { resultIsReference = false; resultType = refExpr->getType(); // Otherwise, try to evaluate as an l-value. } else if (CEK != CEK_AsValueOnly && refExpr->EvaluateAsLValue(result, getContext())) { resultIsReference = true; resultType = value->getType(); // Failure. } else { return ConstantEmission(); } // In any case, if the initializer has side-effects, abandon ship. if (result.HasSideEffects) return ConstantEmission(); // Emit as a constant. llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this); // Make sure we emit a debug reference to the global variable. // This should probably fire even for if (isa(value)) { if (!getContext().DeclMustBeEmitted(cast(value))) EmitDeclRefExprDbgValue(refExpr, C); } else { assert(isa(value)); EmitDeclRefExprDbgValue(refExpr, C); } // If we emitted a reference constant, we need to dereference that. if (resultIsReference) return ConstantEmission::forReference(C); return ConstantEmission::forValue(C); } llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue) { return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(), lvalue.getAlignment().getQuantity(), lvalue.getType(), lvalue.getTBAAInfo()); } static bool hasBooleanRepresentation(QualType Ty) { if (Ty->isBooleanType()) return true; if (const EnumType *ET = Ty->getAs()) return ET->getDecl()->getIntegerType()->isBooleanType(); if (const AtomicType *AT = Ty->getAs()) return hasBooleanRepresentation(AT->getValueType()); return false; } llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) { const EnumType *ET = Ty->getAs(); bool IsRegularCPlusPlusEnum = (getLangOpts().CPlusPlus && ET && CGM.getCodeGenOpts().StrictEnums && !ET->getDecl()->isFixed()); bool IsBool = hasBooleanRepresentation(Ty); llvm::Type *LTy; if (!IsBool && !IsRegularCPlusPlusEnum) return NULL; llvm::APInt Min; llvm::APInt End; if (IsBool) { Min = llvm::APInt(8, 0); End = llvm::APInt(8, 2); LTy = Int8Ty; } else { const EnumDecl *ED = ET->getDecl(); LTy = ConvertTypeForMem(ED->getIntegerType()); unsigned Bitwidth = LTy->getScalarSizeInBits(); unsigned NumNegativeBits = ED->getNumNegativeBits(); unsigned NumPositiveBits = ED->getNumPositiveBits(); if (NumNegativeBits) { unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1); assert(NumBits <= Bitwidth); End = llvm::APInt(Bitwidth, 1) << (NumBits - 1); Min = -End; } else { assert(NumPositiveBits <= Bitwidth); End = llvm::APInt(Bitwidth, 1) << NumPositiveBits; Min = llvm::APInt(Bitwidth, 0); } } llvm::MDBuilder MDHelper(getLLVMContext()); return MDHelper.createRange(Min, End); } llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile, unsigned Alignment, QualType Ty, llvm::MDNode *TBAAInfo) { llvm::LoadInst *Load = Builder.CreateLoad(Addr); if (Volatile) Load->setVolatile(true); if (Alignment) Load->setAlignment(Alignment); if (TBAAInfo) CGM.DecorateInstruction(Load, TBAAInfo); // If this is an atomic type, all normal reads must be atomic if (Ty->isAtomicType()) Load->setAtomic(llvm::SequentiallyConsistent); if (CGM.getCodeGenOpts().OptimizationLevel > 0) if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty)) Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo); return EmitFromMemory(Load, Ty); } llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) { // Bool has a different representation in memory than in registers. if (hasBooleanRepresentation(Ty)) { // This should really always be an i1, but sometimes it's already // an i8, and it's awkward to track those cases down. if (Value->getType()->isIntegerTy(1)) return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool"); assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8"); } return Value; } llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) { // Bool has a different representation in memory than in registers. if (hasBooleanRepresentation(Ty)) { assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8"); return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool"); } return Value; } void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr, bool Volatile, unsigned Alignment, QualType Ty, llvm::MDNode *TBAAInfo, bool isInit) { Value = EmitToMemory(Value, Ty); llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile); if (Alignment) Store->setAlignment(Alignment); if (TBAAInfo) CGM.DecorateInstruction(Store, TBAAInfo); if (!isInit && Ty->isAtomicType()) Store->setAtomic(llvm::SequentiallyConsistent); } void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue, bool isInit) { EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(), lvalue.getAlignment().getQuantity(), lvalue.getType(), lvalue.getTBAAInfo(), isInit); } /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this /// method emits the address of the lvalue, then loads the result as an rvalue, /// returning the rvalue. RValue CodeGenFunction::EmitLoadOfLValue(LValue LV) { if (LV.isObjCWeak()) { // load of a __weak object. llvm::Value *AddrWeakObj = LV.getAddress(); return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this, AddrWeakObj)); } if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) return RValue::get(EmitARCLoadWeak(LV.getAddress())); if (LV.isSimple()) { assert(!LV.getType()->isFunctionType()); // Everything needs a load. return RValue::get(EmitLoadOfScalar(LV)); } if (LV.isVectorElt()) { llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddr(), LV.isVolatileQualified()); Load->setAlignment(LV.getAlignment().getQuantity()); return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(), "vecext")); } // If this is a reference to a subset of the elements of a vector, either // shuffle the input or extract/insert them as appropriate. if (LV.isExtVectorElt()) return EmitLoadOfExtVectorElementLValue(LV); assert(LV.isBitField() && "Unknown LValue type!"); return EmitLoadOfBitfieldLValue(LV); } RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV) { const CGBitFieldInfo &Info = LV.getBitFieldInfo(); // Get the output type. llvm::Type *ResLTy = ConvertType(LV.getType()); unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy); // Compute the result as an OR of all of the individual component accesses. llvm::Value *Res = 0; for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) { const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i); // Get the field pointer. llvm::Value *Ptr = LV.getBitFieldBaseAddr(); // Only offset by the field index if used, so that incoming values are not // required to be structures. if (AI.FieldIndex) Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field"); // Offset by the byte offset, if used. if (!AI.FieldByteOffset.isZero()) { Ptr = EmitCastToVoidPtr(Ptr); Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(), "bf.field.offs"); } // Cast to the access type. llvm::Type *PTy = llvm::Type::getIntNPtrTy(getLLVMContext(), AI.AccessWidth, CGM.getContext().getTargetAddressSpace(LV.getType())); Ptr = Builder.CreateBitCast(Ptr, PTy); // Perform the load. llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified()); if (!AI.AccessAlignment.isZero()) Load->setAlignment(AI.AccessAlignment.getQuantity()); // Shift out unused low bits and mask out unused high bits. llvm::Value *Val = Load; if (AI.FieldBitStart) Val = Builder.CreateLShr(Load, AI.FieldBitStart); Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth, AI.TargetBitWidth), "bf.clear"); // Extend or truncate to the target size. if (AI.AccessWidth < ResSizeInBits) Val = Builder.CreateZExt(Val, ResLTy); else if (AI.AccessWidth > ResSizeInBits) Val = Builder.CreateTrunc(Val, ResLTy); // Shift into place, and OR into the result. if (AI.TargetBitOffset) Val = Builder.CreateShl(Val, AI.TargetBitOffset); Res = Res ? Builder.CreateOr(Res, Val) : Val; } // If the bit-field is signed, perform the sign-extension. // // FIXME: This can easily be folded into the load of the high bits, which // could also eliminate the mask of high bits in some situations. if (Info.isSigned()) { unsigned ExtraBits = ResSizeInBits - Info.getSize(); if (ExtraBits) Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits), ExtraBits, "bf.val.sext"); } return RValue::get(Res); } // If this is a reference to a subset of the elements of a vector, create an // appropriate shufflevector. RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) { llvm::LoadInst *Load = Builder.CreateLoad(LV.getExtVectorAddr(), LV.isVolatileQualified()); Load->setAlignment(LV.getAlignment().getQuantity()); llvm::Value *Vec = Load; const llvm::Constant *Elts = LV.getExtVectorElts(); // If the result of the expression is a non-vector type, we must be extracting // a single element. Just codegen as an extractelement. const VectorType *ExprVT = LV.getType()->getAs(); if (!ExprVT) { unsigned InIdx = getAccessedFieldNo(0, Elts); llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx); return RValue::get(Builder.CreateExtractElement(Vec, Elt)); } // Always use shuffle vector to try to retain the original program structure unsigned NumResultElts = ExprVT->getNumElements(); SmallVector Mask; for (unsigned i = 0; i != NumResultElts; ++i) Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts))); llvm::Value *MaskV = llvm::ConstantVector::get(Mask); Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()), MaskV); return RValue::get(Vec); } /// EmitStoreThroughLValue - Store the specified rvalue into the specified /// lvalue, where both are guaranteed to the have the same type, and that type /// is 'Ty'. void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit) { if (!Dst.isSimple()) { if (Dst.isVectorElt()) { // Read/modify/write the vector, inserting the new element. llvm::LoadInst *Load = Builder.CreateLoad(Dst.getVectorAddr(), Dst.isVolatileQualified()); Load->setAlignment(Dst.getAlignment().getQuantity()); llvm::Value *Vec = Load; Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(), Dst.getVectorIdx(), "vecins"); llvm::StoreInst *Store = Builder.CreateStore(Vec, Dst.getVectorAddr(), Dst.isVolatileQualified()); Store->setAlignment(Dst.getAlignment().getQuantity()); return; } // If this is an update of extended vector elements, insert them as // appropriate. if (Dst.isExtVectorElt()) return EmitStoreThroughExtVectorComponentLValue(Src, Dst); assert(Dst.isBitField() && "Unknown LValue type"); return EmitStoreThroughBitfieldLValue(Src, Dst); } // There's special magic for assigning into an ARC-qualified l-value. if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) { switch (Lifetime) { case Qualifiers::OCL_None: llvm_unreachable("present but none"); case Qualifiers::OCL_ExplicitNone: // nothing special break; case Qualifiers::OCL_Strong: EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true); return; case Qualifiers::OCL_Weak: EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true); return; case Qualifiers::OCL_Autoreleasing: Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(), Src.getScalarVal())); // fall into the normal path break; } } if (Dst.isObjCWeak() && !Dst.isNonGC()) { // load of a __weak object. llvm::Value *LvalueDst = Dst.getAddress(); llvm::Value *src = Src.getScalarVal(); CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst); return; } if (Dst.isObjCStrong() && !Dst.isNonGC()) { // load of a __strong object. llvm::Value *LvalueDst = Dst.getAddress(); llvm::Value *src = Src.getScalarVal(); if (Dst.isObjCIvar()) { assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL"); llvm::Type *ResultType = ConvertType(getContext().LongTy); llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp()); llvm::Value *dst = RHS; RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); llvm::Value *LHS = Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast"); llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset"); CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst, BytesBetween); } else if (Dst.isGlobalObjCRef()) { CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst, Dst.isThreadLocalRef()); } else CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst); return; } assert(Src.isScalar() && "Can't emit an agg store with this method"); EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit); } void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, llvm::Value **Result) { const CGBitFieldInfo &Info = Dst.getBitFieldInfo(); // Get the output type. llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType()); unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy); // Get the source value, truncated to the width of the bit-field. llvm::Value *SrcVal = Src.getScalarVal(); if (hasBooleanRepresentation(Dst.getType())) SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false); SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits, Info.getSize()), "bf.value"); // Return the new value of the bit-field, if requested. if (Result) { // Cast back to the proper type for result. llvm::Type *SrcTy = Src.getScalarVal()->getType(); llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false, "bf.reload.val"); // Sign extend if necessary. if (Info.isSigned()) { unsigned ExtraBits = ResSizeInBits - Info.getSize(); if (ExtraBits) ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits), ExtraBits, "bf.reload.sext"); } *Result = ReloadVal; } // Iterate over the components, writing each piece to memory. for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) { const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i); // Get the field pointer. llvm::Value *Ptr = Dst.getBitFieldBaseAddr(); unsigned addressSpace = cast(Ptr->getType())->getAddressSpace(); // Only offset by the field index if used, so that incoming values are not // required to be structures. if (AI.FieldIndex) Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field"); // Offset by the byte offset, if used. if (!AI.FieldByteOffset.isZero()) { Ptr = EmitCastToVoidPtr(Ptr); Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(), "bf.field.offs"); } // Cast to the access type. llvm::Type *AccessLTy = llvm::Type::getIntNTy(getLLVMContext(), AI.AccessWidth); llvm::Type *PTy = AccessLTy->getPointerTo(addressSpace); Ptr = Builder.CreateBitCast(Ptr, PTy); // Extract the piece of the bit-field value to write in this access, limited // to the values that are part of this access. llvm::Value *Val = SrcVal; if (AI.TargetBitOffset) Val = Builder.CreateLShr(Val, AI.TargetBitOffset); Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits, AI.TargetBitWidth)); // Extend or truncate to the access size. if (ResSizeInBits < AI.AccessWidth) Val = Builder.CreateZExt(Val, AccessLTy); else if (ResSizeInBits > AI.AccessWidth) Val = Builder.CreateTrunc(Val, AccessLTy); // Shift into the position in memory. if (AI.FieldBitStart) Val = Builder.CreateShl(Val, AI.FieldBitStart); // If necessary, load and OR in bits that are outside of the bit-field. if (AI.TargetBitWidth != AI.AccessWidth) { llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified()); if (!AI.AccessAlignment.isZero()) Load->setAlignment(AI.AccessAlignment.getQuantity()); // Compute the mask for zeroing the bits that are part of the bit-field. llvm::APInt InvMask = ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart, AI.FieldBitStart + AI.TargetBitWidth); // Apply the mask and OR in to the value to write. Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val); } // Write the value. llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr, Dst.isVolatileQualified()); if (!AI.AccessAlignment.isZero()) Store->setAlignment(AI.AccessAlignment.getQuantity()); } } void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst) { // This access turns into a read/modify/write of the vector. Load the input // value now. llvm::LoadInst *Load = Builder.CreateLoad(Dst.getExtVectorAddr(), Dst.isVolatileQualified()); Load->setAlignment(Dst.getAlignment().getQuantity()); llvm::Value *Vec = Load; const llvm::Constant *Elts = Dst.getExtVectorElts(); llvm::Value *SrcVal = Src.getScalarVal(); if (const VectorType *VTy = Dst.getType()->getAs()) { unsigned NumSrcElts = VTy->getNumElements(); unsigned NumDstElts = cast(Vec->getType())->getNumElements(); if (NumDstElts == NumSrcElts) { // Use shuffle vector is the src and destination are the same number of // elements and restore the vector mask since it is on the side it will be // stored. SmallVector Mask(NumDstElts); for (unsigned i = 0; i != NumSrcElts; ++i) Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i); llvm::Value *MaskV = llvm::ConstantVector::get(Mask); Vec = Builder.CreateShuffleVector(SrcVal, llvm::UndefValue::get(Vec->getType()), MaskV); } else if (NumDstElts > NumSrcElts) { // Extended the source vector to the same length and then shuffle it // into the destination. // FIXME: since we're shuffling with undef, can we just use the indices // into that? This could be simpler. SmallVector ExtMask; for (unsigned i = 0; i != NumSrcElts; ++i) ExtMask.push_back(Builder.getInt32(i)); ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty)); llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask); llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, llvm::UndefValue::get(SrcVal->getType()), ExtMaskV); // build identity SmallVector Mask; for (unsigned i = 0; i != NumDstElts; ++i) Mask.push_back(Builder.getInt32(i)); // modify when what gets shuffled in for (unsigned i = 0; i != NumSrcElts; ++i) Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts); llvm::Value *MaskV = llvm::ConstantVector::get(Mask); Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV); } else { // We should never shorten the vector llvm_unreachable("unexpected shorten vector length"); } } else { // If the Src is a scalar (not a vector) it must be updating one element. unsigned InIdx = getAccessedFieldNo(0, Elts); llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx); Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt); } llvm::StoreInst *Store = Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified()); Store->setAlignment(Dst.getAlignment().getQuantity()); } // setObjCGCLValueClass - sets class of he lvalue for the purpose of // generating write-barries API. It is currently a global, ivar, // or neither. static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E, LValue &LV, bool IsMemberAccess=false) { if (Ctx.getLangOpts().getGC() == LangOptions::NonGC) return; if (isa(E)) { QualType ExpTy = E->getType(); if (IsMemberAccess && ExpTy->isPointerType()) { // If ivar is a structure pointer, assigning to field of // this struct follows gcc's behavior and makes it a non-ivar // writer-barrier conservatively. ExpTy = ExpTy->getAs()->getPointeeType(); if (ExpTy->isRecordType()) { LV.setObjCIvar(false); return; } } LV.setObjCIvar(true); ObjCIvarRefExpr *Exp = cast(const_cast(E)); LV.setBaseIvarExp(Exp->getBase()); LV.setObjCArray(E->getType()->isArrayType()); return; } if (const DeclRefExpr *Exp = dyn_cast(E)) { if (const VarDecl *VD = dyn_cast(Exp->getDecl())) { if (VD->hasGlobalStorage()) { LV.setGlobalObjCRef(true); LV.setThreadLocalRef(VD->isThreadSpecified()); } } LV.setObjCArray(E->getType()->isArrayType()); return; } if (const UnaryOperator *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); return; } if (const ParenExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); if (LV.isObjCIvar()) { // If cast is to a structure pointer, follow gcc's behavior and make it // a non-ivar write-barrier. QualType ExpTy = E->getType(); if (ExpTy->isPointerType()) ExpTy = ExpTy->getAs()->getPointeeType(); if (ExpTy->isRecordType()) LV.setObjCIvar(false); } return; } if (const GenericSelectionExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV); return; } if (const ImplicitCastExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); return; } if (const CStyleCastExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); return; } if (const ObjCBridgedCastExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); return; } if (const ArraySubscriptExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getBase(), LV); if (LV.isObjCIvar() && !LV.isObjCArray()) // Using array syntax to assigning to what an ivar points to is not // same as assigning to the ivar itself. {id *Names;} Names[i] = 0; LV.setObjCIvar(false); else if (LV.isGlobalObjCRef() && !LV.isObjCArray()) // Using array syntax to assigning to what global points to is not // same as assigning to the global itself. {id *G;} G[i] = 0; LV.setGlobalObjCRef(false); return; } if (const MemberExpr *Exp = dyn_cast(E)) { setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true); // We don't know if member is an 'ivar', but this flag is looked at // only in the context of LV.isObjCIvar(). LV.setObjCArray(E->getType()->isArrayType()); return; } } static llvm::Value * EmitBitCastOfLValueToProperType(CodeGenFunction &CGF, llvm::Value *V, llvm::Type *IRType, StringRef Name = StringRef()) { unsigned AS = cast(V->getType())->getAddressSpace(); return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name); } static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF, const Expr *E, const VarDecl *VD) { assert((VD->hasExternalStorage() || VD->isFileVarDecl()) && "Var decl must have external storage or be a file var decl!"); llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD); llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType()); V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy); CharUnits Alignment = CGF.getContext().getDeclAlign(VD); QualType T = E->getType(); LValue LV; if (VD->getType()->isReferenceType()) { llvm::LoadInst *LI = CGF.Builder.CreateLoad(V); LI->setAlignment(Alignment.getQuantity()); V = LI; LV = CGF.MakeNaturalAlignAddrLValue(V, T); } else { LV = CGF.MakeAddrLValue(V, E->getType(), Alignment); } setObjCGCLValueClass(CGF.getContext(), E, LV); return LV; } static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, const Expr *E, const FunctionDecl *FD) { llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD); if (!FD->hasPrototype()) { if (const FunctionProtoType *Proto = FD->getType()->getAs()) { // Ugly case: for a K&R-style definition, the type of the definition // isn't the same as the type of a use. Correct for this with a // bitcast. QualType NoProtoType = CGF.getContext().getFunctionNoProtoType(Proto->getResultType()); NoProtoType = CGF.getContext().getPointerType(NoProtoType); V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType)); } } CharUnits Alignment = CGF.getContext().getDeclAlign(FD); return CGF.MakeAddrLValue(V, E->getType(), Alignment); } LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) { const NamedDecl *ND = E->getDecl(); CharUnits Alignment = getContext().getDeclAlign(ND); QualType T = E->getType(); // FIXME: We should be able to assert this for FunctionDecls as well! // FIXME: We should be able to assert this for all DeclRefExprs, not just // those with a valid source location. assert((ND->isUsed(false) || !isa(ND) || !E->getLocation().isValid()) && "Should not use decl without marking it used!"); if (ND->hasAttr()) { const ValueDecl *VD = cast(ND); llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD); return MakeAddrLValue(Aliasee, E->getType(), Alignment); } if (const VarDecl *VD = dyn_cast(ND)) { // Check if this is a global variable. if (VD->hasExternalStorage() || VD->isFileVarDecl()) return EmitGlobalVarDeclLValue(*this, E, VD); bool isBlockVariable = VD->hasAttr(); bool NonGCable = VD->hasLocalStorage() && !VD->getType()->isReferenceType() && !isBlockVariable; llvm::Value *V = LocalDeclMap[VD]; if (!V && VD->isStaticLocal()) V = CGM.getStaticLocalDeclAddress(VD); // Use special handling for lambdas. if (!V) { if (FieldDecl *FD = LambdaCaptureFields.lookup(VD)) { QualType LambdaTagType = getContext().getTagDeclType(FD->getParent()); LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType); return EmitLValueForField(LambdaLV, FD); } assert(isa(CurCodeDecl) && E->refersToEnclosingLocal()); CharUnits alignment = getContext().getDeclAlign(VD); return MakeAddrLValue(GetAddrOfBlockDecl(VD, isBlockVariable), E->getType(), alignment); } assert(V && "DeclRefExpr not entered in LocalDeclMap?"); if (isBlockVariable) V = BuildBlockByrefAddress(V, VD); LValue LV; if (VD->getType()->isReferenceType()) { llvm::LoadInst *LI = Builder.CreateLoad(V); LI->setAlignment(Alignment.getQuantity()); V = LI; LV = MakeNaturalAlignAddrLValue(V, T); } else { LV = MakeAddrLValue(V, T, Alignment); } if (NonGCable) { LV.getQuals().removeObjCGCAttr(); LV.setNonGC(true); } setObjCGCLValueClass(getContext(), E, LV); return LV; } if (const FunctionDecl *fn = dyn_cast(ND)) return EmitFunctionDeclLValue(*this, E, fn); llvm_unreachable("Unhandled DeclRefExpr"); } LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) { // __extension__ doesn't affect lvalue-ness. if (E->getOpcode() == UO_Extension) return EmitLValue(E->getSubExpr()); QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType()); switch (E->getOpcode()) { default: llvm_unreachable("Unknown unary operator lvalue!"); case UO_Deref: { QualType T = E->getSubExpr()->getType()->getPointeeType(); assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type"); LValue LV = MakeNaturalAlignAddrLValue(EmitScalarExpr(E->getSubExpr()), T); LV.getQuals().setAddressSpace(ExprTy.getAddressSpace()); // We should not generate __weak write barrier on indirect reference // of a pointer to object; as in void foo (__weak id *param); *param = 0; // But, we continue to generate __strong write barrier on indirect write // into a pointer to object. if (getContext().getLangOpts().ObjC1 && getContext().getLangOpts().getGC() != LangOptions::NonGC && LV.isObjCWeak()) LV.setNonGC(!E->isOBJCGCCandidate(getContext())); return LV; } case UO_Real: case UO_Imag: { LValue LV = EmitLValue(E->getSubExpr()); assert(LV.isSimple() && "real/imag on non-ordinary l-value"); llvm::Value *Addr = LV.getAddress(); // __real is valid on scalars. This is a faster way of testing that. // __imag can only produce an rvalue on scalars. if (E->getOpcode() == UO_Real && !cast(Addr->getType()) ->getElementType()->isStructTy()) { assert(E->getSubExpr()->getType()->isArithmeticType()); return LV; } assert(E->getSubExpr()->getType()->isAnyComplexType()); unsigned Idx = E->getOpcode() == UO_Imag; return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(), Idx, "idx"), ExprTy); } case UO_PreInc: case UO_PreDec: { LValue LV = EmitLValue(E->getSubExpr()); bool isInc = E->getOpcode() == UO_PreInc; if (E->getType()->isAnyComplexType()) EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/); else EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/); return LV; } } } LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) { return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E), E->getType()); } LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) { return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E), E->getType()); } LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) { switch (E->getIdentType()) { default: return EmitUnsupportedLValue(E, "predefined expression"); case PredefinedExpr::Func: case PredefinedExpr::Function: case PredefinedExpr::PrettyFunction: { unsigned Type = E->getIdentType(); std::string GlobalVarName; switch (Type) { default: llvm_unreachable("Invalid type"); case PredefinedExpr::Func: GlobalVarName = "__func__."; break; case PredefinedExpr::Function: GlobalVarName = "__FUNCTION__."; break; case PredefinedExpr::PrettyFunction: GlobalVarName = "__PRETTY_FUNCTION__."; break; } StringRef FnName = CurFn->getName(); if (FnName.startswith("\01")) FnName = FnName.substr(1); GlobalVarName += FnName; const Decl *CurDecl = CurCodeDecl; if (CurDecl == 0) CurDecl = getContext().getTranslationUnitDecl(); std::string FunctionName = (isa(CurDecl) ? FnName.str() : PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl)); llvm::Constant *C = CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str()); return MakeAddrLValue(C, E->getType()); } } } llvm::BasicBlock *CodeGenFunction::getTrapBB() { const CodeGenOptions &GCO = CGM.getCodeGenOpts(); // If we are not optimzing, don't collapse all calls to trap in the function // to the same call, that way, in the debugger they can see which operation // did in fact fail. If we are optimizing, we collapse all calls to trap down // to just one per function to save on codesize. if (GCO.OptimizationLevel && TrapBB) return TrapBB; llvm::BasicBlock *Cont = 0; if (HaveInsertPoint()) { Cont = createBasicBlock("cont"); EmitBranch(Cont); } TrapBB = createBasicBlock("trap"); EmitBlock(TrapBB); llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap); llvm::CallInst *TrapCall = Builder.CreateCall(F); TrapCall->setDoesNotReturn(); TrapCall->setDoesNotThrow(); Builder.CreateUnreachable(); if (Cont) EmitBlock(Cont); return TrapBB; } /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an /// array to pointer, return the array subexpression. static const Expr *isSimpleArrayDecayOperand(const Expr *E) { // If this isn't just an array->pointer decay, bail out. const CastExpr *CE = dyn_cast(E); if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay) return 0; // If this is a decay from variable width array, bail out. const Expr *SubExpr = CE->getSubExpr(); if (SubExpr->getType()->isVariableArrayType()) return 0; return SubExpr; } LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) { // The index must always be an integer, which is not an aggregate. Emit it. llvm::Value *Idx = EmitScalarExpr(E->getIdx()); QualType IdxTy = E->getIdx()->getType(); bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType(); // If the base is a vector type, then we are forming a vector element lvalue // with this subscript. if (E->getBase()->getType()->isVectorType()) { // Emit the vector as an lvalue to get its address. LValue LHS = EmitLValue(E->getBase()); assert(LHS.isSimple() && "Can only subscript lvalue vectors here!"); Idx = Builder.CreateIntCast(Idx, Int32Ty, IdxSigned, "vidx"); return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(), LHS.getAlignment()); } // Extend or truncate the index type to 32 or 64-bits. if (Idx->getType() != IntPtrTy) Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom"); // FIXME: As llvm implements the object size checking, this can come out. if (CatchUndefined) { if (const ImplicitCastExpr *ICE = dyn_cast(E->getBase())){ if (const DeclRefExpr *DRE = dyn_cast(ICE->getSubExpr())) { if (ICE->getCastKind() == CK_ArrayToPointerDecay) { if (const ConstantArrayType *CAT = getContext().getAsConstantArrayType(DRE->getType())) { llvm::APInt Size = CAT->getSize(); llvm::BasicBlock *Cont = createBasicBlock("cont"); Builder.CreateCondBr(Builder.CreateICmpULE(Idx, llvm::ConstantInt::get(Idx->getType(), Size)), Cont, getTrapBB()); EmitBlock(Cont); } } } } } // We know that the pointer points to a type of the correct size, unless the // size is a VLA or Objective-C interface. llvm::Value *Address = 0; CharUnits ArrayAlignment; if (const VariableArrayType *vla = getContext().getAsVariableArrayType(E->getType())) { // The base must be a pointer, which is not an aggregate. Emit // it. It needs to be emitted first in case it's what captures // the VLA bounds. Address = EmitScalarExpr(E->getBase()); // The element count here is the total number of non-VLA elements. llvm::Value *numElements = getVLASize(vla).first; // Effectively, the multiply by the VLA size is part of the GEP. // GEP indexes are signed, and scaling an index isn't permitted to // signed-overflow, so we use the same semantics for our explicit // multiply. We suppress this if overflow is not undefined behavior. if (getLangOpts().isSignedOverflowDefined()) { Idx = Builder.CreateMul(Idx, numElements); Address = Builder.CreateGEP(Address, Idx, "arrayidx"); } else { Idx = Builder.CreateNSWMul(Idx, numElements); Address = Builder.CreateInBoundsGEP(Address, Idx, "arrayidx"); } } else if (const ObjCObjectType *OIT = E->getType()->getAs()){ // Indexing over an interface, as in "NSString *P; P[4];" llvm::Value *InterfaceSize = llvm::ConstantInt::get(Idx->getType(), getContext().getTypeSizeInChars(OIT).getQuantity()); Idx = Builder.CreateMul(Idx, InterfaceSize); // The base must be a pointer, which is not an aggregate. Emit it. llvm::Value *Base = EmitScalarExpr(E->getBase()); Address = EmitCastToVoidPtr(Base); Address = Builder.CreateGEP(Address, Idx, "arrayidx"); Address = Builder.CreateBitCast(Address, Base->getType()); } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) { // If this is A[i] where A is an array, the frontend will have decayed the // base to be a ArrayToPointerDecay implicit cast. While correct, it is // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a // "gep x, i" here. Emit one "gep A, 0, i". assert(Array->getType()->isArrayType() && "Array to pointer decay must have array source type!"); LValue ArrayLV = EmitLValue(Array); llvm::Value *ArrayPtr = ArrayLV.getAddress(); llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0); llvm::Value *Args[] = { Zero, Idx }; // Propagate the alignment from the array itself to the result. ArrayAlignment = ArrayLV.getAlignment(); if (getContext().getLangOpts().isSignedOverflowDefined()) Address = Builder.CreateGEP(ArrayPtr, Args, "arrayidx"); else Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, "arrayidx"); } else { // The base must be a pointer, which is not an aggregate. Emit it. llvm::Value *Base = EmitScalarExpr(E->getBase()); if (getContext().getLangOpts().isSignedOverflowDefined()) Address = Builder.CreateGEP(Base, Idx, "arrayidx"); else Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx"); } QualType T = E->getBase()->getType()->getPointeeType(); assert(!T.isNull() && "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type"); // Limit the alignment to that of the result type. LValue LV; if (!ArrayAlignment.isZero()) { CharUnits Align = getContext().getTypeAlignInChars(T); ArrayAlignment = std::min(Align, ArrayAlignment); LV = MakeAddrLValue(Address, T, ArrayAlignment); } else { LV = MakeNaturalAlignAddrLValue(Address, T); } LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace()); if (getContext().getLangOpts().ObjC1 && getContext().getLangOpts().getGC() != LangOptions::NonGC) { LV.setNonGC(!E->isOBJCGCCandidate(getContext())); setObjCGCLValueClass(getContext(), E, LV); } return LV; } static llvm::Constant *GenerateConstantVector(CGBuilderTy &Builder, SmallVector &Elts) { SmallVector CElts; for (unsigned i = 0, e = Elts.size(); i != e; ++i) CElts.push_back(Builder.getInt32(Elts[i])); return llvm::ConstantVector::get(CElts); } LValue CodeGenFunction:: EmitExtVectorElementExpr(const ExtVectorElementExpr *E) { // Emit the base vector as an l-value. LValue Base; // ExtVectorElementExpr's base can either be a vector or pointer to vector. if (E->isArrow()) { // If it is a pointer to a vector, emit the address and form an lvalue with // it. llvm::Value *Ptr = EmitScalarExpr(E->getBase()); const PointerType *PT = E->getBase()->getType()->getAs(); Base = MakeAddrLValue(Ptr, PT->getPointeeType()); Base.getQuals().removeObjCGCAttr(); } else if (E->getBase()->isGLValue()) { // Otherwise, if the base is an lvalue ( as in the case of foo.x.x), // emit the base as an lvalue. assert(E->getBase()->getType()->isVectorType()); Base = EmitLValue(E->getBase()); } else { // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such. assert(E->getBase()->getType()->isVectorType() && "Result must be a vector"); llvm::Value *Vec = EmitScalarExpr(E->getBase()); // Store the vector to memory (because LValue wants an address). llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType()); Builder.CreateStore(Vec, VecMem); Base = MakeAddrLValue(VecMem, E->getBase()->getType()); } QualType type = E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers()); // Encode the element access list into a vector of unsigned indices. SmallVector Indices; E->getEncodedElementAccess(Indices); if (Base.isSimple()) { llvm::Constant *CV = GenerateConstantVector(Builder, Indices); return LValue::MakeExtVectorElt(Base.getAddress(), CV, type, Base.getAlignment()); } assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!"); llvm::Constant *BaseElts = Base.getExtVectorElts(); SmallVector CElts; for (unsigned i = 0, e = Indices.size(); i != e; ++i) CElts.push_back(BaseElts->getAggregateElement(Indices[i])); llvm::Constant *CV = llvm::ConstantVector::get(CElts); return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV, type, Base.getAlignment()); } LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) { Expr *BaseExpr = E->getBase(); // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. LValue BaseLV; if (E->isArrow()) BaseLV = MakeNaturalAlignAddrLValue(EmitScalarExpr(BaseExpr), BaseExpr->getType()->getPointeeType()); else BaseLV = EmitLValue(BaseExpr); NamedDecl *ND = E->getMemberDecl(); if (FieldDecl *Field = dyn_cast(ND)) { LValue LV = EmitLValueForField(BaseLV, Field); setObjCGCLValueClass(getContext(), E, LV); return LV; } if (VarDecl *VD = dyn_cast(ND)) return EmitGlobalVarDeclLValue(*this, E, VD); if (const FunctionDecl *FD = dyn_cast(ND)) return EmitFunctionDeclLValue(*this, E, FD); llvm_unreachable("Unhandled member declaration!"); } LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue, const FieldDecl *Field, unsigned CVRQualifiers) { const CGRecordLayout &RL = CGM.getTypes().getCGRecordLayout(Field->getParent()); const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field); return LValue::MakeBitfield(BaseValue, Info, Field->getType().withCVRQualifiers(CVRQualifiers)); } /// EmitLValueForAnonRecordField - Given that the field is a member of /// an anonymous struct or union buried inside a record, and given /// that the base value is a pointer to the enclosing record, derive /// an lvalue for the ultimate field. LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue, const IndirectFieldDecl *Field, unsigned CVRQualifiers) { IndirectFieldDecl::chain_iterator I = Field->chain_begin(), IEnd = Field->chain_end(); while (true) { QualType RecordTy = getContext().getTypeDeclType(cast(*I)->getParent()); LValue LV = EmitLValueForField(MakeAddrLValue(BaseValue, RecordTy), cast(*I)); if (++I == IEnd) return LV; assert(LV.isSimple()); BaseValue = LV.getAddress(); CVRQualifiers |= LV.getVRQualifiers(); } } LValue CodeGenFunction::EmitLValueForField(LValue base, const FieldDecl *field) { if (field->isBitField()) return EmitLValueForBitfield(base.getAddress(), field, base.getVRQualifiers()); const RecordDecl *rec = field->getParent(); QualType type = field->getType(); CharUnits alignment = getContext().getDeclAlign(field); // FIXME: It should be impossible to have an LValue without alignment for a // complete type. if (!base.getAlignment().isZero()) alignment = std::min(alignment, base.getAlignment()); bool mayAlias = rec->hasAttr(); llvm::Value *addr = base.getAddress(); unsigned cvr = base.getVRQualifiers(); if (rec->isUnion()) { // For unions, there is no pointer adjustment. assert(!type->isReferenceType() && "union has reference member"); } else { // For structs, we GEP to the field that the record layout suggests. unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field); addr = Builder.CreateStructGEP(addr, idx, field->getName()); // If this is a reference field, load the reference right now. if (const ReferenceType *refType = type->getAs()) { llvm::LoadInst *load = Builder.CreateLoad(addr, "ref"); if (cvr & Qualifiers::Volatile) load->setVolatile(true); load->setAlignment(alignment.getQuantity()); if (CGM.shouldUseTBAA()) { llvm::MDNode *tbaa; if (mayAlias) tbaa = CGM.getTBAAInfo(getContext().CharTy); else tbaa = CGM.getTBAAInfo(type); CGM.DecorateInstruction(load, tbaa); } addr = load; mayAlias = false; type = refType->getPointeeType(); if (type->isIncompleteType()) alignment = CharUnits(); else alignment = getContext().getTypeAlignInChars(type); cvr = 0; // qualifiers don't recursively apply to referencee } } // Make sure that the address is pointing to the right type. This is critical // for both unions and structs. A union needs a bitcast, a struct element // will need a bitcast if the LLVM type laid out doesn't match the desired // type. addr = EmitBitCastOfLValueToProperType(*this, addr, CGM.getTypes().ConvertTypeForMem(type), field->getName()); if (field->hasAttr()) addr = EmitFieldAnnotations(field, addr); LValue LV = MakeAddrLValue(addr, type, alignment); LV.getQuals().addCVRQualifiers(cvr); // __weak attribute on a field is ignored. if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak) LV.getQuals().removeObjCGCAttr(); // Fields of may_alias structs act like 'char' for TBAA purposes. // FIXME: this should get propagated down through anonymous structs // and unions. if (mayAlias && LV.getTBAAInfo()) LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy)); return LV; } LValue CodeGenFunction::EmitLValueForFieldInitialization(LValue Base, const FieldDecl *Field) { QualType FieldType = Field->getType(); if (!FieldType->isReferenceType()) return EmitLValueForField(Base, Field); const CGRecordLayout &RL = CGM.getTypes().getCGRecordLayout(Field->getParent()); unsigned idx = RL.getLLVMFieldNo(Field); llvm::Value *V = Builder.CreateStructGEP(Base.getAddress(), idx); assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs"); // Make sure that the address is pointing to the right type. This is critical // for both unions and structs. A union needs a bitcast, a struct element // will need a bitcast if the LLVM type laid out doesn't match the desired // type. llvm::Type *llvmType = ConvertTypeForMem(FieldType); V = EmitBitCastOfLValueToProperType(*this, V, llvmType, Field->getName()); CharUnits Alignment = getContext().getDeclAlign(Field); // FIXME: It should be impossible to have an LValue without alignment for a // complete type. if (!Base.getAlignment().isZero()) Alignment = std::min(Alignment, Base.getAlignment()); return MakeAddrLValue(V, FieldType, Alignment); } LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){ if (E->isFileScope()) { llvm::Value *GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E); return MakeAddrLValue(GlobalPtr, E->getType()); } llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral"); const Expr *InitExpr = E->getInitializer(); LValue Result = MakeAddrLValue(DeclPtr, E->getType()); EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(), /*Init*/ true); return Result; } LValue CodeGenFunction:: EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) { if (!expr->isGLValue()) { // ?: here should be an aggregate. assert((hasAggregateLLVMType(expr->getType()) && !expr->getType()->isAnyComplexType()) && "Unexpected conditional operator!"); return EmitAggExprToLValue(expr); } OpaqueValueMapping binding(*this, expr); const Expr *condExpr = expr->getCond(); bool CondExprBool; if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr(); if (!CondExprBool) std::swap(live, dead); if (!ContainsLabel(dead)) return EmitLValue(live); } llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true"); llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false"); llvm::BasicBlock *contBlock = createBasicBlock("cond.end"); ConditionalEvaluation eval(*this); EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock); // Any temporaries created here are conditional. EmitBlock(lhsBlock); eval.begin(*this); LValue lhs = EmitLValue(expr->getTrueExpr()); eval.end(*this); if (!lhs.isSimple()) return EmitUnsupportedLValue(expr, "conditional operator"); lhsBlock = Builder.GetInsertBlock(); Builder.CreateBr(contBlock); // Any temporaries created here are conditional. EmitBlock(rhsBlock); eval.begin(*this); LValue rhs = EmitLValue(expr->getFalseExpr()); eval.end(*this); if (!rhs.isSimple()) return EmitUnsupportedLValue(expr, "conditional operator"); rhsBlock = Builder.GetInsertBlock(); EmitBlock(contBlock); llvm::PHINode *phi = Builder.CreatePHI(lhs.getAddress()->getType(), 2, "cond-lvalue"); phi->addIncoming(lhs.getAddress(), lhsBlock); phi->addIncoming(rhs.getAddress(), rhsBlock); return MakeAddrLValue(phi, expr->getType()); } /// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast. /// If the cast is a dynamic_cast, we can have the usual lvalue result, /// otherwise if a cast is needed by the code generator in an lvalue context, /// then it must mean that we need the address of an aggregate in order to /// access one of its fields. This can happen for all the reasons that casts /// are permitted with aggregate result, including noop aggregate casts, and /// cast from scalar to union. LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) { switch (E->getCastKind()) { case CK_ToVoid: return EmitUnsupportedLValue(E, "unexpected cast lvalue"); case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!"); // These two casts are currently treated as no-ops, although they could // potentially be real operations depending on the target's ABI. case CK_NonAtomicToAtomic: case CK_AtomicToNonAtomic: case CK_NoOp: case CK_LValueToRValue: if (!E->getSubExpr()->Classify(getContext()).isPRValue() || E->getType()->isRecordType()) return EmitLValue(E->getSubExpr()); // Fall through to synthesize a temporary. case CK_BitCast: case CK_ArrayToPointerDecay: case CK_FunctionToPointerDecay: case CK_NullToMemberPointer: case CK_NullToPointer: case CK_IntegralToPointer: case CK_PointerToIntegral: case CK_PointerToBoolean: case CK_VectorSplat: case CK_IntegralCast: case CK_IntegralToBoolean: case CK_IntegralToFloating: case CK_FloatingToIntegral: case CK_FloatingToBoolean: case CK_FloatingCast: 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_DerivedToBaseMemberPointer: case CK_BaseToDerivedMemberPointer: case CK_MemberPointerToBoolean: case CK_ReinterpretMemberPointer: case CK_AnyPointerToBlockPointerCast: case CK_ARCProduceObject: case CK_ARCConsumeObject: case CK_ARCReclaimReturnedObject: case CK_ARCExtendBlockObject: case CK_CopyAndAutoreleaseBlockObject: { // These casts only produce lvalues when we're binding a reference to a // temporary realized from a (converted) pure rvalue. Emit the expression // as a value, copy it into a temporary, and return an lvalue referring to // that temporary. llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp"); EmitAnyExprToMem(E, V, E->getType().getQualifiers(), false); return MakeAddrLValue(V, E->getType()); } case CK_Dynamic: { LValue LV = EmitLValue(E->getSubExpr()); llvm::Value *V = LV.getAddress(); const CXXDynamicCastExpr *DCE = cast(E); return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType()); } case CK_ConstructorConversion: case CK_UserDefinedConversion: case CK_CPointerToObjCPointerCast: case CK_BlockPointerToObjCPointerCast: return EmitLValue(E->getSubExpr()); case CK_UncheckedDerivedToBase: case CK_DerivedToBase: { const RecordType *DerivedClassTy = E->getSubExpr()->getType()->getAs(); CXXRecordDecl *DerivedClassDecl = cast(DerivedClassTy->getDecl()); LValue LV = EmitLValue(E->getSubExpr()); llvm::Value *This = LV.getAddress(); // Perform the derived-to-base conversion llvm::Value *Base = GetAddressOfBaseClass(This, DerivedClassDecl, E->path_begin(), E->path_end(), /*NullCheckValue=*/false); return MakeAddrLValue(Base, E->getType()); } case CK_ToUnion: return EmitAggExprToLValue(E); case CK_BaseToDerived: { const RecordType *DerivedClassTy = E->getType()->getAs(); CXXRecordDecl *DerivedClassDecl = cast(DerivedClassTy->getDecl()); LValue LV = EmitLValue(E->getSubExpr()); // Perform the base-to-derived conversion llvm::Value *Derived = GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl, E->path_begin(), E->path_end(), /*NullCheckValue=*/false); return MakeAddrLValue(Derived, E->getType()); } case CK_LValueBitCast: { // This must be a reinterpret_cast (or c-style equivalent). const ExplicitCastExpr *CE = cast(E); LValue LV = EmitLValue(E->getSubExpr()); llvm::Value *V = Builder.CreateBitCast(LV.getAddress(), ConvertType(CE->getTypeAsWritten())); return MakeAddrLValue(V, E->getType()); } case CK_ObjCObjectLValueCast: { LValue LV = EmitLValue(E->getSubExpr()); QualType ToType = getContext().getLValueReferenceType(E->getType()); llvm::Value *V = Builder.CreateBitCast(LV.getAddress(), ConvertType(ToType)); return MakeAddrLValue(V, E->getType()); } } llvm_unreachable("Unhandled lvalue cast kind?"); } LValue CodeGenFunction::EmitNullInitializationLValue( const CXXScalarValueInitExpr *E) { QualType Ty = E->getType(); LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty); EmitNullInitialization(LV.getAddress(), Ty); return LV; } LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) { assert(OpaqueValueMappingData::shouldBindAsLValue(e)); return getOpaqueLValueMapping(e); } LValue CodeGenFunction::EmitMaterializeTemporaryExpr( const MaterializeTemporaryExpr *E) { RValue RV = EmitReferenceBindingToExpr(E, /*InitializedDecl=*/0); return MakeAddrLValue(RV.getScalarVal(), E->getType()); } RValue CodeGenFunction::EmitRValueForField(LValue LV, const FieldDecl *FD) { QualType FT = FD->getType(); LValue FieldLV = EmitLValueForField(LV, FD); if (FT->isAnyComplexType()) return RValue::getComplex( LoadComplexFromAddr(FieldLV.getAddress(), FieldLV.isVolatileQualified())); else if (CodeGenFunction::hasAggregateLLVMType(FT)) return FieldLV.asAggregateRValue(); return EmitLoadOfLValue(FieldLV); } //===--------------------------------------------------------------------===// // Expression Emission //===--------------------------------------------------------------------===// RValue CodeGenFunction::EmitCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue) { if (CGDebugInfo *DI = getDebugInfo()) DI->EmitLocation(Builder, E->getLocStart()); // Builtins never have block type. if (E->getCallee()->getType()->isBlockPointerType()) return EmitBlockCallExpr(E, ReturnValue); if (const CXXMemberCallExpr *CE = dyn_cast(E)) return EmitCXXMemberCallExpr(CE, ReturnValue); if (const CUDAKernelCallExpr *CE = dyn_cast(E)) return EmitCUDAKernelCallExpr(CE, ReturnValue); const Decl *TargetDecl = E->getCalleeDecl(); if (const FunctionDecl *FD = dyn_cast_or_null(TargetDecl)) { if (unsigned builtinID = FD->getBuiltinID()) return EmitBuiltinExpr(FD, builtinID, E); } if (const CXXOperatorCallExpr *CE = dyn_cast(E)) if (const CXXMethodDecl *MD = dyn_cast_or_null(TargetDecl)) return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue); if (const CXXPseudoDestructorExpr *PseudoDtor = dyn_cast(E->getCallee()->IgnoreParens())) { QualType DestroyedType = PseudoDtor->getDestroyedType(); if (getContext().getLangOpts().ObjCAutoRefCount && DestroyedType->isObjCLifetimeType() && (DestroyedType.getObjCLifetime() == Qualifiers::OCL_Strong || DestroyedType.getObjCLifetime() == Qualifiers::OCL_Weak)) { // Automatic Reference Counting: // If the pseudo-expression names a retainable object with weak or // strong lifetime, the object shall be released. Expr *BaseExpr = PseudoDtor->getBase(); llvm::Value *BaseValue = NULL; Qualifiers BaseQuals; // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. if (PseudoDtor->isArrow()) { BaseValue = EmitScalarExpr(BaseExpr); const PointerType *PTy = BaseExpr->getType()->getAs(); BaseQuals = PTy->getPointeeType().getQualifiers(); } else { LValue BaseLV = EmitLValue(BaseExpr); BaseValue = BaseLV.getAddress(); QualType BaseTy = BaseExpr->getType(); BaseQuals = BaseTy.getQualifiers(); } switch (PseudoDtor->getDestroyedType().getObjCLifetime()) { case Qualifiers::OCL_None: case Qualifiers::OCL_ExplicitNone: case Qualifiers::OCL_Autoreleasing: break; case Qualifiers::OCL_Strong: EmitARCRelease(Builder.CreateLoad(BaseValue, PseudoDtor->getDestroyedType().isVolatileQualified()), /*precise*/ true); break; case Qualifiers::OCL_Weak: EmitARCDestroyWeak(BaseValue); break; } } else { // C++ [expr.pseudo]p1: // The result shall only be used as the operand for the function call // operator (), and the result of such a call has type void. The only // effect is the evaluation of the postfix-expression before the dot or // arrow. EmitScalarExpr(E->getCallee()); } return RValue::get(0); } llvm::Value *Callee = EmitScalarExpr(E->getCallee()); return EmitCall(E->getCallee()->getType(), Callee, ReturnValue, E->arg_begin(), E->arg_end(), TargetDecl); } LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) { // Comma expressions just emit their LHS then their RHS as an l-value. if (E->getOpcode() == BO_Comma) { EmitIgnoredExpr(E->getLHS()); EnsureInsertPoint(); return EmitLValue(E->getRHS()); } if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI) return EmitPointerToDataMemberBinaryExpr(E); assert(E->getOpcode() == BO_Assign && "unexpected binary l-value"); // Note that in all of these cases, __block variables need the RHS // evaluated first just in case the variable gets moved by the RHS. if (!hasAggregateLLVMType(E->getType())) { switch (E->getLHS()->getType().getObjCLifetime()) { case Qualifiers::OCL_Strong: return EmitARCStoreStrong(E, /*ignored*/ false).first; case Qualifiers::OCL_Autoreleasing: return EmitARCStoreAutoreleasing(E).first; // No reason to do any of these differently. case Qualifiers::OCL_None: case Qualifiers::OCL_ExplicitNone: case Qualifiers::OCL_Weak: break; } RValue RV = EmitAnyExpr(E->getRHS()); LValue LV = EmitLValue(E->getLHS()); EmitStoreThroughLValue(RV, LV); return LV; } if (E->getType()->isAnyComplexType()) return EmitComplexAssignmentLValue(E); return EmitAggExprToLValue(E); } LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) { RValue RV = EmitCallExpr(E); if (!RV.isScalar()) return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); assert(E->getCallReturnType()->isReferenceType() && "Can't have a scalar return unless the return type is a " "reference type!"); return MakeAddrLValue(RV.getScalarVal(), E->getType()); } LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) { // FIXME: This shouldn't require another copy. return EmitAggExprToLValue(E); } LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) { assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor() && "binding l-value to type which needs a temporary"); AggValueSlot Slot = CreateAggTemp(E->getType()); EmitCXXConstructExpr(E, Slot); return MakeAddrLValue(Slot.getAddr(), E->getType()); } LValue CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) { return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType()); } LValue CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) { AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue"); Slot.setExternallyDestructed(); EmitAggExpr(E->getSubExpr(), Slot); EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddr()); return MakeAddrLValue(Slot.getAddr(), E->getType()); } LValue CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) { AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue"); EmitLambdaExpr(E, Slot); return MakeAddrLValue(Slot.getAddr(), E->getType()); } LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) { RValue RV = EmitObjCMessageExpr(E); if (!RV.isScalar()) return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); assert(E->getMethodDecl()->getResultType()->isReferenceType() && "Can't have a scalar return unless the return type is a " "reference type!"); return MakeAddrLValue(RV.getScalarVal(), E->getType()); } LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) { llvm::Value *V = CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true); return MakeAddrLValue(V, E->getType()); } llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface, const ObjCIvarDecl *Ivar) { return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar); } LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy, llvm::Value *BaseValue, const ObjCIvarDecl *Ivar, unsigned CVRQualifiers) { return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue, Ivar, CVRQualifiers); } LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) { // FIXME: A lot of the code below could be shared with EmitMemberExpr. llvm::Value *BaseValue = 0; const Expr *BaseExpr = E->getBase(); Qualifiers BaseQuals; QualType ObjectTy; if (E->isArrow()) { BaseValue = EmitScalarExpr(BaseExpr); ObjectTy = BaseExpr->getType()->getPointeeType(); BaseQuals = ObjectTy.getQualifiers(); } else { LValue BaseLV = EmitLValue(BaseExpr); // FIXME: this isn't right for bitfields. BaseValue = BaseLV.getAddress(); ObjectTy = BaseExpr->getType(); BaseQuals = ObjectTy.getQualifiers(); } LValue LV = EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(), BaseQuals.getCVRQualifiers()); setObjCGCLValueClass(getContext(), E, LV); return LV; } LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) { // Can only get l-value for message expression returning aggregate type RValue RV = EmitAnyExprToTemp(E); return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); } RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee, ReturnValueSlot ReturnValue, CallExpr::const_arg_iterator ArgBeg, CallExpr::const_arg_iterator ArgEnd, const Decl *TargetDecl) { // Get the actual function type. The callee type will always be a pointer to // function type or a block pointer type. assert(CalleeType->isFunctionPointerType() && "Call must have function pointer type!"); CalleeType = getContext().getCanonicalType(CalleeType); const FunctionType *FnType = cast(cast(CalleeType)->getPointeeType()); CallArgList Args; EmitCallArgs(Args, dyn_cast(FnType), ArgBeg, ArgEnd); const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFunctionCall(Args, FnType); // C99 6.5.2.2p6: // If the expression that denotes the called function has a type // that does not include a prototype, [the default argument // promotions are performed]. If the number of arguments does not // equal the number of parameters, the behavior is undefined. If // the function is defined with a type that includes a prototype, // and either the prototype ends with an ellipsis (, ...) or the // types of the arguments after promotion are not compatible with // the types of the parameters, the behavior is undefined. If the // function is defined with a type that does not include a // prototype, and the types of the arguments after promotion are // not compatible with those of the parameters after promotion, // the behavior is undefined [except in some trivial cases]. // That is, in the general case, we should assume that a call // through an unprototyped function type works like a *non-variadic* // call. The way we make this work is to cast to the exact type // of the promoted arguments. if (isa(FnType) && !FnInfo.isVariadic()) { llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo); CalleeTy = CalleeTy->getPointerTo(); Callee = Builder.CreateBitCast(Callee, CalleeTy, "callee.knr.cast"); } return EmitCall(FnInfo, Callee, ReturnValue, Args, TargetDecl); } LValue CodeGenFunction:: EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) { llvm::Value *BaseV; if (E->getOpcode() == BO_PtrMemI) BaseV = EmitScalarExpr(E->getLHS()); else BaseV = EmitLValue(E->getLHS()).getAddress(); llvm::Value *OffsetV = EmitScalarExpr(E->getRHS()); const MemberPointerType *MPT = E->getRHS()->getType()->getAs(); llvm::Value *AddV = CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT); return MakeAddrLValue(AddV, MPT->getPointeeType()); } static void EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *E, llvm::Value *Dest, llvm::Value *Ptr, llvm::Value *Val1, llvm::Value *Val2, uint64_t Size, unsigned Align, llvm::AtomicOrdering Order) { llvm::AtomicRMWInst::BinOp Op = llvm::AtomicRMWInst::Add; llvm::Instruction::BinaryOps PostOp = (llvm::Instruction::BinaryOps)0; switch (E->getOp()) { case AtomicExpr::AO__c11_atomic_init: llvm_unreachable("Already handled!"); case AtomicExpr::AO__c11_atomic_compare_exchange_strong: case AtomicExpr::AO__c11_atomic_compare_exchange_weak: case AtomicExpr::AO__atomic_compare_exchange: case AtomicExpr::AO__atomic_compare_exchange_n: { // Note that cmpxchg only supports specifying one ordering and // doesn't support weak cmpxchg, at least at the moment. llvm::LoadInst *LoadVal1 = CGF.Builder.CreateLoad(Val1); LoadVal1->setAlignment(Align); llvm::LoadInst *LoadVal2 = CGF.Builder.CreateLoad(Val2); LoadVal2->setAlignment(Align); llvm::AtomicCmpXchgInst *CXI = CGF.Builder.CreateAtomicCmpXchg(Ptr, LoadVal1, LoadVal2, Order); CXI->setVolatile(E->isVolatile()); llvm::StoreInst *StoreVal1 = CGF.Builder.CreateStore(CXI, Val1); StoreVal1->setAlignment(Align); llvm::Value *Cmp = CGF.Builder.CreateICmpEQ(CXI, LoadVal1); CGF.EmitStoreOfScalar(Cmp, CGF.MakeAddrLValue(Dest, E->getType())); return; } case AtomicExpr::AO__c11_atomic_load: case AtomicExpr::AO__atomic_load_n: case AtomicExpr::AO__atomic_load: { llvm::LoadInst *Load = CGF.Builder.CreateLoad(Ptr); Load->setAtomic(Order); Load->setAlignment(Size); Load->setVolatile(E->isVolatile()); llvm::StoreInst *StoreDest = CGF.Builder.CreateStore(Load, Dest); StoreDest->setAlignment(Align); return; } case AtomicExpr::AO__c11_atomic_store: case AtomicExpr::AO__atomic_store: case AtomicExpr::AO__atomic_store_n: { assert(!Dest && "Store does not return a value"); llvm::LoadInst *LoadVal1 = CGF.Builder.CreateLoad(Val1); LoadVal1->setAlignment(Align); llvm::StoreInst *Store = CGF.Builder.CreateStore(LoadVal1, Ptr); Store->setAtomic(Order); Store->setAlignment(Size); Store->setVolatile(E->isVolatile()); return; } case AtomicExpr::AO__c11_atomic_exchange: case AtomicExpr::AO__atomic_exchange_n: case AtomicExpr::AO__atomic_exchange: Op = llvm::AtomicRMWInst::Xchg; break; case AtomicExpr::AO__atomic_add_fetch: PostOp = llvm::Instruction::Add; // Fall through. case AtomicExpr::AO__c11_atomic_fetch_add: case AtomicExpr::AO__atomic_fetch_add: Op = llvm::AtomicRMWInst::Add; break; case AtomicExpr::AO__atomic_sub_fetch: PostOp = llvm::Instruction::Sub; // Fall through. case AtomicExpr::AO__c11_atomic_fetch_sub: case AtomicExpr::AO__atomic_fetch_sub: Op = llvm::AtomicRMWInst::Sub; break; case AtomicExpr::AO__atomic_and_fetch: PostOp = llvm::Instruction::And; // Fall through. case AtomicExpr::AO__c11_atomic_fetch_and: case AtomicExpr::AO__atomic_fetch_and: Op = llvm::AtomicRMWInst::And; break; case AtomicExpr::AO__atomic_or_fetch: PostOp = llvm::Instruction::Or; // Fall through. case AtomicExpr::AO__c11_atomic_fetch_or: case AtomicExpr::AO__atomic_fetch_or: Op = llvm::AtomicRMWInst::Or; break; case AtomicExpr::AO__atomic_xor_fetch: PostOp = llvm::Instruction::Xor; // Fall through. case AtomicExpr::AO__c11_atomic_fetch_xor: case AtomicExpr::AO__atomic_fetch_xor: Op = llvm::AtomicRMWInst::Xor; break; case AtomicExpr::AO__atomic_nand_fetch: PostOp = llvm::Instruction::And; // Fall through. case AtomicExpr::AO__atomic_fetch_nand: Op = llvm::AtomicRMWInst::Nand; break; } llvm::LoadInst *LoadVal1 = CGF.Builder.CreateLoad(Val1); LoadVal1->setAlignment(Align); llvm::AtomicRMWInst *RMWI = CGF.Builder.CreateAtomicRMW(Op, Ptr, LoadVal1, Order); RMWI->setVolatile(E->isVolatile()); // For __atomic_*_fetch operations, perform the operation again to // determine the value which was written. llvm::Value *Result = RMWI; if (PostOp) Result = CGF.Builder.CreateBinOp(PostOp, RMWI, LoadVal1); if (E->getOp() == AtomicExpr::AO__atomic_nand_fetch) Result = CGF.Builder.CreateNot(Result); llvm::StoreInst *StoreDest = CGF.Builder.CreateStore(Result, Dest); StoreDest->setAlignment(Align); } // This function emits any expression (scalar, complex, or aggregate) // into a temporary alloca. static llvm::Value * EmitValToTemp(CodeGenFunction &CGF, Expr *E) { llvm::Value *DeclPtr = CGF.CreateMemTemp(E->getType(), ".atomictmp"); CGF.EmitAnyExprToMem(E, DeclPtr, E->getType().getQualifiers(), /*Init*/ true); return DeclPtr; } static RValue ConvertTempToRValue(CodeGenFunction &CGF, QualType Ty, llvm::Value *Dest) { if (Ty->isAnyComplexType()) return RValue::getComplex(CGF.LoadComplexFromAddr(Dest, false)); if (CGF.hasAggregateLLVMType(Ty)) return RValue::getAggregate(Dest); return RValue::get(CGF.EmitLoadOfScalar(CGF.MakeAddrLValue(Dest, Ty))); } RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E, llvm::Value *Dest) { QualType AtomicTy = E->getPtr()->getType()->getPointeeType(); QualType MemTy = AtomicTy; if (const AtomicType *AT = AtomicTy->getAs()) MemTy = AT->getValueType(); CharUnits sizeChars = getContext().getTypeSizeInChars(AtomicTy); uint64_t Size = sizeChars.getQuantity(); CharUnits alignChars = getContext().getTypeAlignInChars(AtomicTy); unsigned Align = alignChars.getQuantity(); unsigned MaxInlineWidth = getContext().getTargetInfo().getMaxAtomicInlineWidth(); bool UseLibcall = (Size != Align || Size > MaxInlineWidth); llvm::Value *Ptr, *Order, *OrderFail = 0, *Val1 = 0, *Val2 = 0; Ptr = EmitScalarExpr(E->getPtr()); if (E->getOp() == AtomicExpr::AO__c11_atomic_init) { assert(!Dest && "Init does not return a value"); if (!hasAggregateLLVMType(E->getVal1()->getType())) { QualType PointeeType = E->getPtr()->getType()->getAs()->getPointeeType(); EmitScalarInit(EmitScalarExpr(E->getVal1()), LValue::MakeAddr(Ptr, PointeeType, alignChars, getContext())); } else if (E->getType()->isAnyComplexType()) { EmitComplexExprIntoAddr(E->getVal1(), Ptr, E->isVolatile()); } else { AggValueSlot Slot = AggValueSlot::forAddr(Ptr, alignChars, AtomicTy.getQualifiers(), AggValueSlot::IsNotDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); EmitAggExpr(E->getVal1(), Slot); } return RValue::get(0); } Order = EmitScalarExpr(E->getOrder()); switch (E->getOp()) { case AtomicExpr::AO__c11_atomic_init: llvm_unreachable("Already handled!"); case AtomicExpr::AO__c11_atomic_load: case AtomicExpr::AO__atomic_load_n: break; case AtomicExpr::AO__atomic_load: Dest = EmitScalarExpr(E->getVal1()); break; case AtomicExpr::AO__atomic_store: Val1 = EmitScalarExpr(E->getVal1()); break; case AtomicExpr::AO__atomic_exchange: Val1 = EmitScalarExpr(E->getVal1()); Dest = EmitScalarExpr(E->getVal2()); break; case AtomicExpr::AO__c11_atomic_compare_exchange_strong: case AtomicExpr::AO__c11_atomic_compare_exchange_weak: case AtomicExpr::AO__atomic_compare_exchange_n: case AtomicExpr::AO__atomic_compare_exchange: Val1 = EmitScalarExpr(E->getVal1()); if (E->getOp() == AtomicExpr::AO__atomic_compare_exchange) Val2 = EmitScalarExpr(E->getVal2()); else Val2 = EmitValToTemp(*this, E->getVal2()); OrderFail = EmitScalarExpr(E->getOrderFail()); // Evaluate and discard the 'weak' argument. if (E->getNumSubExprs() == 6) EmitScalarExpr(E->getWeak()); break; case AtomicExpr::AO__c11_atomic_fetch_add: case AtomicExpr::AO__c11_atomic_fetch_sub: if (MemTy->isPointerType()) { // For pointer arithmetic, we're required to do a bit of math: // adding 1 to an int* is not the same as adding 1 to a uintptr_t. // ... but only for the C11 builtins. The GNU builtins expect the // user to multiply by sizeof(T). QualType Val1Ty = E->getVal1()->getType(); llvm::Value *Val1Scalar = EmitScalarExpr(E->getVal1()); CharUnits PointeeIncAmt = getContext().getTypeSizeInChars(MemTy->getPointeeType()); Val1Scalar = Builder.CreateMul(Val1Scalar, CGM.getSize(PointeeIncAmt)); Val1 = CreateMemTemp(Val1Ty, ".atomictmp"); EmitStoreOfScalar(Val1Scalar, MakeAddrLValue(Val1, Val1Ty)); break; } // Fall through. case AtomicExpr::AO__atomic_fetch_add: case AtomicExpr::AO__atomic_fetch_sub: case AtomicExpr::AO__atomic_add_fetch: case AtomicExpr::AO__atomic_sub_fetch: case AtomicExpr::AO__c11_atomic_store: case AtomicExpr::AO__c11_atomic_exchange: case AtomicExpr::AO__atomic_store_n: case AtomicExpr::AO__atomic_exchange_n: case AtomicExpr::AO__c11_atomic_fetch_and: case AtomicExpr::AO__c11_atomic_fetch_or: case AtomicExpr::AO__c11_atomic_fetch_xor: case AtomicExpr::AO__atomic_fetch_and: case AtomicExpr::AO__atomic_fetch_or: case AtomicExpr::AO__atomic_fetch_xor: case AtomicExpr::AO__atomic_fetch_nand: case AtomicExpr::AO__atomic_and_fetch: case AtomicExpr::AO__atomic_or_fetch: case AtomicExpr::AO__atomic_xor_fetch: case AtomicExpr::AO__atomic_nand_fetch: Val1 = EmitValToTemp(*this, E->getVal1()); break; } if (!E->getType()->isVoidType() && !Dest) Dest = CreateMemTemp(E->getType(), ".atomicdst"); // Use a library call. See: http://gcc.gnu.org/wiki/Atomic/GCCMM/LIbrary . if (UseLibcall) { llvm::SmallVector Params; CallArgList Args; // Size is always the first parameter Args.add(RValue::get(llvm::ConstantInt::get(SizeTy, Size)), getContext().getSizeType()); // Atomic address is always the second parameter Args.add(RValue::get(EmitCastToVoidPtr(Ptr)), getContext().VoidPtrTy); const char* LibCallName; QualType RetTy = getContext().VoidTy; switch (E->getOp()) { // There is only one libcall for compare an exchange, because there is no // optimisation benefit possible from a libcall version of a weak compare // and exchange. // bool __atomic_compare_exchange(size_t size, void *obj, void *expected, // void *desired, int success, int failure) case AtomicExpr::AO__c11_atomic_compare_exchange_weak: case AtomicExpr::AO__c11_atomic_compare_exchange_strong: case AtomicExpr::AO__atomic_compare_exchange: case AtomicExpr::AO__atomic_compare_exchange_n: LibCallName = "__atomic_compare_exchange"; RetTy = getContext().BoolTy; Args.add(RValue::get(EmitCastToVoidPtr(Val1)), getContext().VoidPtrTy); Args.add(RValue::get(EmitCastToVoidPtr(Val2)), getContext().VoidPtrTy); Args.add(RValue::get(Order), getContext().IntTy); Order = OrderFail; break; // void __atomic_exchange(size_t size, void *mem, void *val, void *return, // int order) case AtomicExpr::AO__c11_atomic_exchange: case AtomicExpr::AO__atomic_exchange_n: case AtomicExpr::AO__atomic_exchange: LibCallName = "__atomic_exchange"; Args.add(RValue::get(EmitCastToVoidPtr(Val1)), getContext().VoidPtrTy); Args.add(RValue::get(EmitCastToVoidPtr(Dest)), getContext().VoidPtrTy); break; // void __atomic_store(size_t size, void *mem, void *val, int order) case AtomicExpr::AO__c11_atomic_store: case AtomicExpr::AO__atomic_store: case AtomicExpr::AO__atomic_store_n: LibCallName = "__atomic_store"; Args.add(RValue::get(EmitCastToVoidPtr(Val1)), getContext().VoidPtrTy); break; // void __atomic_load(size_t size, void *mem, void *return, int order) case AtomicExpr::AO__c11_atomic_load: case AtomicExpr::AO__atomic_load: case AtomicExpr::AO__atomic_load_n: LibCallName = "__atomic_load"; Args.add(RValue::get(EmitCastToVoidPtr(Dest)), getContext().VoidPtrTy); break; #if 0 // These are only defined for 1-16 byte integers. It is not clear what // their semantics would be on anything else... case AtomicExpr::Add: LibCallName = "__atomic_fetch_add_generic"; break; case AtomicExpr::Sub: LibCallName = "__atomic_fetch_sub_generic"; break; case AtomicExpr::And: LibCallName = "__atomic_fetch_and_generic"; break; case AtomicExpr::Or: LibCallName = "__atomic_fetch_or_generic"; break; case AtomicExpr::Xor: LibCallName = "__atomic_fetch_xor_generic"; break; #endif default: return EmitUnsupportedRValue(E, "atomic library call"); } // order is always the last parameter Args.add(RValue::get(Order), getContext().IntTy); const CGFunctionInfo &FuncInfo = CGM.getTypes().arrangeFunctionCall(RetTy, Args, FunctionType::ExtInfo(), RequiredArgs::All); llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FuncInfo); llvm::Constant *Func = CGM.CreateRuntimeFunction(FTy, LibCallName); RValue Res = EmitCall(FuncInfo, Func, ReturnValueSlot(), Args); if (E->isCmpXChg()) return Res; if (E->getType()->isVoidType()) return RValue::get(0); return ConvertTempToRValue(*this, E->getType(), Dest); } llvm::Type *IPtrTy = llvm::IntegerType::get(getLLVMContext(), Size * 8)->getPointerTo(); llvm::Value *OrigDest = Dest; Ptr = Builder.CreateBitCast(Ptr, IPtrTy); if (Val1) Val1 = Builder.CreateBitCast(Val1, IPtrTy); if (Val2) Val2 = Builder.CreateBitCast(Val2, IPtrTy); if (Dest && !E->isCmpXChg()) Dest = Builder.CreateBitCast(Dest, IPtrTy); if (isa(Order)) { int ord = cast(Order)->getZExtValue(); switch (ord) { case 0: // memory_order_relaxed EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::Monotonic); break; case 1: // memory_order_consume case 2: // memory_order_acquire EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::Acquire); break; case 3: // memory_order_release EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::Release); break; case 4: // memory_order_acq_rel EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::AcquireRelease); break; case 5: // memory_order_seq_cst EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::SequentiallyConsistent); break; default: // invalid order // We should not ever get here normally, but it's hard to // enforce that in general. break; } if (E->getType()->isVoidType()) return RValue::get(0); return ConvertTempToRValue(*this, E->getType(), OrigDest); } // Long case, when Order isn't obviously constant. bool IsStore = E->getOp() == AtomicExpr::AO__c11_atomic_store || E->getOp() == AtomicExpr::AO__atomic_store || E->getOp() == AtomicExpr::AO__atomic_store_n; bool IsLoad = E->getOp() == AtomicExpr::AO__c11_atomic_load || E->getOp() == AtomicExpr::AO__atomic_load || E->getOp() == AtomicExpr::AO__atomic_load_n; // Create all the relevant BB's llvm::BasicBlock *MonotonicBB = 0, *AcquireBB = 0, *ReleaseBB = 0, *AcqRelBB = 0, *SeqCstBB = 0; MonotonicBB = createBasicBlock("monotonic", CurFn); if (!IsStore) AcquireBB = createBasicBlock("acquire", CurFn); if (!IsLoad) ReleaseBB = createBasicBlock("release", CurFn); if (!IsLoad && !IsStore) AcqRelBB = createBasicBlock("acqrel", CurFn); SeqCstBB = createBasicBlock("seqcst", CurFn); llvm::BasicBlock *ContBB = createBasicBlock("atomic.continue", CurFn); // Create the switch for the split // MonotonicBB is arbitrarily chosen as the default case; in practice, this // doesn't matter unless someone is crazy enough to use something that // doesn't fold to a constant for the ordering. Order = Builder.CreateIntCast(Order, Builder.getInt32Ty(), false); llvm::SwitchInst *SI = Builder.CreateSwitch(Order, MonotonicBB); // Emit all the different atomics Builder.SetInsertPoint(MonotonicBB); EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::Monotonic); Builder.CreateBr(ContBB); if (!IsStore) { Builder.SetInsertPoint(AcquireBB); EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::Acquire); Builder.CreateBr(ContBB); SI->addCase(Builder.getInt32(1), AcquireBB); SI->addCase(Builder.getInt32(2), AcquireBB); } if (!IsLoad) { Builder.SetInsertPoint(ReleaseBB); EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::Release); Builder.CreateBr(ContBB); SI->addCase(Builder.getInt32(3), ReleaseBB); } if (!IsLoad && !IsStore) { Builder.SetInsertPoint(AcqRelBB); EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::AcquireRelease); Builder.CreateBr(ContBB); SI->addCase(Builder.getInt32(4), AcqRelBB); } Builder.SetInsertPoint(SeqCstBB); EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align, llvm::SequentiallyConsistent); Builder.CreateBr(ContBB); SI->addCase(Builder.getInt32(5), SeqCstBB); // Cleanup and return Builder.SetInsertPoint(ContBB); if (E->getType()->isVoidType()) return RValue::get(0); return ConvertTempToRValue(*this, E->getType(), OrigDest); } void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) { assert(Val->getType()->isFPOrFPVectorTy()); if (Accuracy == 0.0 || !isa(Val)) return; llvm::MDBuilder MDHelper(getLLVMContext()); llvm::MDNode *Node = MDHelper.createFPMath(Accuracy); cast(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node); } namespace { struct LValueOrRValue { LValue LV; RValue RV; }; } static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF, const PseudoObjectExpr *E, bool forLValue, AggValueSlot slot) { llvm::SmallVector opaques; // Find the result expression, if any. const Expr *resultExpr = E->getResultExpr(); LValueOrRValue result; for (PseudoObjectExpr::const_semantics_iterator i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) { const Expr *semantic = *i; // If this semantic expression is an opaque value, bind it // to the result of its source expression. if (const OpaqueValueExpr *ov = dyn_cast(semantic)) { // If this is the result expression, we may need to evaluate // directly into the slot. typedef CodeGenFunction::OpaqueValueMappingData OVMA; OVMA opaqueData; if (ov == resultExpr && ov->isRValue() && !forLValue && CodeGenFunction::hasAggregateLLVMType(ov->getType()) && !ov->getType()->isAnyComplexType()) { CGF.EmitAggExpr(ov->getSourceExpr(), slot); LValue LV = CGF.MakeAddrLValue(slot.getAddr(), ov->getType()); opaqueData = OVMA::bind(CGF, ov, LV); result.RV = slot.asRValue(); // Otherwise, emit as normal. } else { opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr()); // If this is the result, also evaluate the result now. if (ov == resultExpr) { if (forLValue) result.LV = CGF.EmitLValue(ov); else result.RV = CGF.EmitAnyExpr(ov, slot); } } opaques.push_back(opaqueData); // Otherwise, if the expression is the result, evaluate it // and remember the result. } else if (semantic == resultExpr) { if (forLValue) result.LV = CGF.EmitLValue(semantic); else result.RV = CGF.EmitAnyExpr(semantic, slot); // Otherwise, evaluate the expression in an ignored context. } else { CGF.EmitIgnoredExpr(semantic); } } // Unbind all the opaques now. for (unsigned i = 0, e = opaques.size(); i != e; ++i) opaques[i].unbind(CGF); return result; } RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E, AggValueSlot slot) { return emitPseudoObjectExpr(*this, E, false, slot).RV; } LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) { return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV; }