diff options
Diffstat (limited to 'lib/CodeGen/CGExprCXX.cpp')
| -rw-r--r-- | lib/CodeGen/CGExprCXX.cpp | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp new file mode 100644 index 0000000..b982c15 --- /dev/null +++ b/lib/CodeGen/CGExprCXX.cpp @@ -0,0 +1,527 @@ +//===--- CGExprCXX.cpp - Emit LLVM Code for C++ 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 dealing with code generation of C++ expressions +// +//===----------------------------------------------------------------------===// + +#include "CodeGenFunction.h" +using namespace clang; +using namespace CodeGen; + +static uint64_t CalculateCookiePadding(ASTContext &Ctx, const CXXNewExpr *E) { + if (!E->isArray()) + return 0; + + QualType T = E->getAllocatedType(); + + const RecordType *RT = T->getAs<RecordType>(); + if (!RT) + return 0; + + const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()); + if (!RD) + return 0; + + // Check if the class has a trivial destructor. + if (RD->hasTrivialDestructor()) { + // FIXME: Check for a two-argument delete. + return 0; + } + + // Padding is the maximum of sizeof(size_t) and alignof(T) + return std::max(Ctx.getTypeSize(Ctx.getSizeType()), + static_cast<uint64_t>(Ctx.getTypeAlign(T))) / 8; +} + +static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF, + const CXXNewExpr *E, + llvm::Value *& NumElements) { + QualType Type = E->getAllocatedType(); + uint64_t TypeSizeInBytes = CGF.getContext().getTypeSize(Type) / 8; + const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType()); + + if (!E->isArray()) + return llvm::ConstantInt::get(SizeTy, TypeSizeInBytes); + + uint64_t CookiePadding = CalculateCookiePadding(CGF.getContext(), E); + + Expr::EvalResult Result; + if (E->getArraySize()->Evaluate(Result, CGF.getContext()) && + !Result.HasSideEffects && Result.Val.isInt()) { + + uint64_t AllocSize = + Result.Val.getInt().getZExtValue() * TypeSizeInBytes + CookiePadding; + + NumElements = + llvm::ConstantInt::get(SizeTy, Result.Val.getInt().getZExtValue()); + + return llvm::ConstantInt::get(SizeTy, AllocSize); + } + + // Emit the array size expression. + NumElements = CGF.EmitScalarExpr(E->getArraySize()); + + // Multiply with the type size. + llvm::Value *V = + CGF.Builder.CreateMul(NumElements, + llvm::ConstantInt::get(SizeTy, TypeSizeInBytes)); + + // And add the cookie padding if necessary. + if (CookiePadding) + V = CGF.Builder.CreateAdd(V, llvm::ConstantInt::get(SizeTy, CookiePadding)); + + return V; +} + +static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E, + llvm::Value *NewPtr, + llvm::Value *NumElements) { + if (E->isArray()) { + if (CXXConstructorDecl *Ctor = E->getConstructor()) + CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr, + E->constructor_arg_begin(), + E->constructor_arg_end()); + return; + } + + QualType AllocType = E->getAllocatedType(); + + if (CXXConstructorDecl *Ctor = E->getConstructor()) { + CGF.EmitCXXConstructorCall(Ctor, Ctor_Complete, NewPtr, + E->constructor_arg_begin(), + E->constructor_arg_end()); + + return; + } + + // We have a POD type. + if (E->getNumConstructorArgs() == 0) + return; + + assert(E->getNumConstructorArgs() == 1 && + "Can only have one argument to initializer of POD type."); + + const Expr *Init = E->getConstructorArg(0); + + if (!CGF.hasAggregateLLVMType(AllocType)) + CGF.EmitStoreOfScalar(CGF.EmitScalarExpr(Init), NewPtr, + AllocType.isVolatileQualified(), AllocType); + else if (AllocType->isAnyComplexType()) + CGF.EmitComplexExprIntoAddr(Init, NewPtr, + AllocType.isVolatileQualified()); + else + CGF.EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified()); +} + +llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { + QualType AllocType = E->getAllocatedType(); + FunctionDecl *NewFD = E->getOperatorNew(); + const FunctionProtoType *NewFTy = NewFD->getType()->getAs<FunctionProtoType>(); + + CallArgList NewArgs; + + // The allocation size is the first argument. + QualType SizeTy = getContext().getSizeType(); + + llvm::Value *NumElements = 0; + llvm::Value *AllocSize = EmitCXXNewAllocSize(*this, E, NumElements); + + NewArgs.push_back(std::make_pair(RValue::get(AllocSize), SizeTy)); + + // Emit the rest of the arguments. + // FIXME: Ideally, this should just use EmitCallArgs. + CXXNewExpr::const_arg_iterator NewArg = E->placement_arg_begin(); + + // First, use the types from the function type. + // We start at 1 here because the first argument (the allocation size) + // has already been emitted. + for (unsigned i = 1, e = NewFTy->getNumArgs(); i != e; ++i, ++NewArg) { + QualType ArgType = NewFTy->getArgType(i); + + assert(getContext().getCanonicalType(ArgType.getNonReferenceType()). + getTypePtr() == + getContext().getCanonicalType(NewArg->getType()).getTypePtr() && + "type mismatch in call argument!"); + + NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType), + ArgType)); + + } + + // Either we've emitted all the call args, or we have a call to a + // variadic function. + assert((NewArg == E->placement_arg_end() || NewFTy->isVariadic()) && + "Extra arguments in non-variadic function!"); + + // If we still have any arguments, emit them using the type of the argument. + for (CXXNewExpr::const_arg_iterator NewArgEnd = E->placement_arg_end(); + NewArg != NewArgEnd; ++NewArg) { + QualType ArgType = NewArg->getType(); + NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType), + ArgType)); + } + + // Emit the call to new. + RValue RV = + EmitCall(CGM.getTypes().getFunctionInfo(NewFTy->getResultType(), NewArgs), + CGM.GetAddrOfFunction(NewFD), NewArgs, NewFD); + + // If an allocation function is declared with an empty exception specification + // it returns null to indicate failure to allocate storage. [expr.new]p13. + // (We don't need to check for null when there's no new initializer and + // we're allocating a POD type). + bool NullCheckResult = NewFTy->hasEmptyExceptionSpec() && + !(AllocType->isPODType() && !E->hasInitializer()); + + llvm::BasicBlock *NewNull = 0; + llvm::BasicBlock *NewNotNull = 0; + llvm::BasicBlock *NewEnd = 0; + + llvm::Value *NewPtr = RV.getScalarVal(); + + if (NullCheckResult) { + NewNull = createBasicBlock("new.null"); + NewNotNull = createBasicBlock("new.notnull"); + NewEnd = createBasicBlock("new.end"); + + llvm::Value *IsNull = + Builder.CreateICmpEQ(NewPtr, + llvm::Constant::getNullValue(NewPtr->getType()), + "isnull"); + + Builder.CreateCondBr(IsNull, NewNull, NewNotNull); + EmitBlock(NewNotNull); + } + + if (uint64_t CookiePadding = CalculateCookiePadding(getContext(), E)) { + uint64_t CookieOffset = + CookiePadding - getContext().getTypeSize(SizeTy) / 8; + + llvm::Value *NumElementsPtr = + Builder.CreateConstInBoundsGEP1_64(NewPtr, CookieOffset); + + NumElementsPtr = Builder.CreateBitCast(NumElementsPtr, + ConvertType(SizeTy)->getPointerTo()); + Builder.CreateStore(NumElements, NumElementsPtr); + + // Now add the padding to the new ptr. + NewPtr = Builder.CreateConstInBoundsGEP1_64(NewPtr, CookiePadding); + } + + NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType())); + + EmitNewInitializer(*this, E, NewPtr, NumElements); + + if (NullCheckResult) { + Builder.CreateBr(NewEnd); + NewNotNull = Builder.GetInsertBlock(); + EmitBlock(NewNull); + Builder.CreateBr(NewEnd); + EmitBlock(NewEnd); + + llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType()); + PHI->reserveOperandSpace(2); + PHI->addIncoming(NewPtr, NewNotNull); + PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()), NewNull); + + NewPtr = PHI; + } + + return NewPtr; +} + +void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD, + llvm::Value *Ptr, + QualType DeleteTy) { + const FunctionProtoType *DeleteFTy = + DeleteFD->getType()->getAs<FunctionProtoType>(); + + CallArgList DeleteArgs; + + QualType ArgTy = DeleteFTy->getArgType(0); + llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy)); + DeleteArgs.push_back(std::make_pair(RValue::get(DeletePtr), ArgTy)); + + if (DeleteFTy->getNumArgs() == 2) { + QualType SizeTy = DeleteFTy->getArgType(1); + uint64_t SizeVal = getContext().getTypeSize(DeleteTy) / 8; + llvm::Constant *Size = llvm::ConstantInt::get(ConvertType(SizeTy), + SizeVal); + DeleteArgs.push_back(std::make_pair(RValue::get(Size), SizeTy)); + } + + // Emit the call to delete. + EmitCall(CGM.getTypes().getFunctionInfo(DeleteFTy->getResultType(), + DeleteArgs), + CGM.GetAddrOfFunction(DeleteFD), + DeleteArgs, DeleteFD); +} + +void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) { + + // Get at the argument before we performed the implicit conversion + // to void*. + const Expr *Arg = E->getArgument(); + while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) { + if (ICE->getCastKind() != CastExpr::CK_UserDefinedConversion && + ICE->getType()->isVoidPointerType()) + Arg = ICE->getSubExpr(); + else + break; + } + + QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType(); + + llvm::Value *Ptr = EmitScalarExpr(Arg); + + // Null check the pointer. + llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull"); + llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end"); + + llvm::Value *IsNull = + Builder.CreateICmpEQ(Ptr, llvm::Constant::getNullValue(Ptr->getType()), + "isnull"); + + Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull); + EmitBlock(DeleteNotNull); + + bool ShouldCallDelete = true; + + // Call the destructor if necessary. + if (const RecordType *RT = DeleteTy->getAs<RecordType>()) { + if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { + if (!RD->hasTrivialDestructor()) { + const CXXDestructorDecl *Dtor = RD->getDestructor(getContext()); + if (E->isArrayForm()) { + QualType SizeTy = getContext().getSizeType(); + uint64_t CookiePadding = std::max(getContext().getTypeSize(SizeTy), + static_cast<uint64_t>(getContext().getTypeAlign(DeleteTy))) / 8; + if (CookiePadding) { + llvm::Type *Ptr8Ty = + llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext), 0); + uint64_t CookieOffset = + CookiePadding - getContext().getTypeSize(SizeTy) / 8; + llvm::Value *AllocatedObjectPtr = + Builder.CreateConstInBoundsGEP1_64( + Builder.CreateBitCast(Ptr, Ptr8Ty), -CookiePadding); + llvm::Value *NumElementsPtr = + Builder.CreateConstInBoundsGEP1_64(AllocatedObjectPtr, + CookieOffset); + NumElementsPtr = Builder.CreateBitCast(NumElementsPtr, + ConvertType(SizeTy)->getPointerTo()); + + llvm::Value *NumElements = + Builder.CreateLoad(NumElementsPtr); + NumElements = + Builder.CreateIntCast(NumElements, + llvm::Type::getInt64Ty(VMContext), false, + "count.tmp"); + EmitCXXAggrDestructorCall(Dtor, NumElements, Ptr); + Ptr = AllocatedObjectPtr; + } + } + else if (Dtor->isVirtual()) { + const llvm::Type *Ty = + CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(Dtor), + /*isVariadic=*/false); + + llvm::Value *Callee = BuildVirtualCall(Dtor, Dtor_Deleting, Ptr, Ty); + EmitCXXMemberCall(Dtor, Callee, Ptr, 0, 0); + + // The dtor took care of deleting the object. + ShouldCallDelete = false; + } else + EmitCXXDestructorCall(Dtor, Dtor_Complete, Ptr); + } + } + } + + if (ShouldCallDelete) + EmitDeleteCall(E->getOperatorDelete(), Ptr, DeleteTy); + + EmitBlock(DeleteEnd); +} + +llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) { + QualType Ty = E->getType(); + const llvm::Type *LTy = ConvertType(Ty)->getPointerTo(); + if (E->isTypeOperand()) { + Ty = E->getTypeOperand(); + CanQualType CanTy = CGM.getContext().getCanonicalType(Ty); + Ty = CanTy.getUnqualifiedType().getNonReferenceType(); + if (const RecordType *RT = Ty->getAs<RecordType>()) { + const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->isPolymorphic()) + return Builder.CreateBitCast(CGM.GenerateRttiRef(RD), LTy); + return Builder.CreateBitCast(CGM.GenerateRtti(RD), LTy); + } + return Builder.CreateBitCast(CGM.GenerateRtti(Ty), LTy); + } + Expr *subE = E->getExprOperand(); + Ty = subE->getType(); + CanQualType CanTy = CGM.getContext().getCanonicalType(Ty); + Ty = CanTy.getUnqualifiedType().getNonReferenceType(); + if (const RecordType *RT = Ty->getAs<RecordType>()) { + const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->isPolymorphic()) { + // FIXME: if subE is an lvalue do + LValue Obj = EmitLValue(subE); + llvm::Value *This = Obj.getAddress(); + LTy = LTy->getPointerTo()->getPointerTo(); + llvm::Value *V = Builder.CreateBitCast(This, LTy); + // We need to do a zero check for *p, unless it has NonNullAttr. + // FIXME: PointerType->hasAttr<NonNullAttr>() + bool CanBeZero = false; + if (UnaryOperator *UO = dyn_cast<UnaryOperator>(subE->IgnoreParens())) + if (UO->getOpcode() == UnaryOperator::Deref) + CanBeZero = true; + if (CanBeZero) { + llvm::BasicBlock *NonZeroBlock = createBasicBlock(); + llvm::BasicBlock *ZeroBlock = createBasicBlock(); + + llvm::Value *Zero = llvm::Constant::getNullValue(LTy); + Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero), + NonZeroBlock, ZeroBlock); + EmitBlock(ZeroBlock); + /// Call __cxa_bad_typeid + const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext); + const llvm::FunctionType *FTy; + FTy = llvm::FunctionType::get(ResultType, false); + llvm::Value *F = CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid"); + Builder.CreateCall(F)->setDoesNotReturn(); + Builder.CreateUnreachable(); + EmitBlock(NonZeroBlock); + } + V = Builder.CreateLoad(V, "vtable"); + V = Builder.CreateConstInBoundsGEP1_64(V, -1ULL); + V = Builder.CreateLoad(V); + return V; + } + return Builder.CreateBitCast(CGM.GenerateRtti(RD), LTy); + } + return Builder.CreateBitCast(CGM.GenerateRtti(Ty), LTy); +} + +llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V, + const CXXDynamicCastExpr *DCE) { + QualType CastTy = DCE->getTypeAsWritten(); + QualType InnerType = CastTy->getPointeeType(); + QualType ArgTy = DCE->getSubExpr()->getType(); + const llvm::Type *LArgTy = ConvertType(ArgTy); + const llvm::Type *LTy = ConvertType(DCE->getType()); + + bool CanBeZero = false; + bool ToVoid = false; + bool ThrowOnBad = false; + if (CastTy->isPointerType()) { + // FIXME: if PointerType->hasAttr<NonNullAttr>(), we don't set this + CanBeZero = true; + if (InnerType->isVoidType()) + ToVoid = true; + } else { + LTy = LTy->getPointerTo(); + ThrowOnBad = true; + } + + CXXRecordDecl *SrcTy; + QualType Ty = ArgTy; + if (ArgTy.getTypePtr()->isPointerType() + || ArgTy.getTypePtr()->isReferenceType()) + Ty = Ty.getTypePtr()->getPointeeType(); + CanQualType CanTy = CGM.getContext().getCanonicalType(Ty); + Ty = CanTy.getUnqualifiedType(); + SrcTy = cast<CXXRecordDecl>(Ty->getAs<RecordType>()->getDecl()); + + llvm::BasicBlock *ContBlock = createBasicBlock(); + llvm::BasicBlock *NullBlock = 0; + llvm::BasicBlock *NonZeroBlock = 0; + if (CanBeZero) { + NonZeroBlock = createBasicBlock(); + NullBlock = createBasicBlock(); + llvm::Value *Zero = llvm::Constant::getNullValue(LArgTy); + Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero), + NonZeroBlock, NullBlock); + EmitBlock(NonZeroBlock); + } + + llvm::BasicBlock *BadCastBlock = 0; + + const llvm::Type *PtrDiffTy = ConvertType(getContext().getSizeType()); + + // See if this is a dynamic_cast(void*) + if (ToVoid) { + llvm::Value *This = V; + V = Builder.CreateBitCast(This, PtrDiffTy->getPointerTo()->getPointerTo()); + V = Builder.CreateLoad(V, "vtable"); + V = Builder.CreateConstInBoundsGEP1_64(V, -2ULL); + V = Builder.CreateLoad(V, "offset to top"); + This = Builder.CreateBitCast(This, llvm::Type::getInt8PtrTy(VMContext)); + V = Builder.CreateInBoundsGEP(This, V); + V = Builder.CreateBitCast(V, LTy); + } else { + /// Call __dynamic_cast + const llvm::Type *ResultType = llvm::Type::getInt8PtrTy(VMContext); + const llvm::FunctionType *FTy; + std::vector<const llvm::Type*> ArgTys; + const llvm::Type *PtrToInt8Ty + = llvm::Type::getInt8Ty(VMContext)->getPointerTo(); + ArgTys.push_back(PtrToInt8Ty); + ArgTys.push_back(PtrToInt8Ty); + ArgTys.push_back(PtrToInt8Ty); + ArgTys.push_back(PtrDiffTy); + FTy = llvm::FunctionType::get(ResultType, ArgTys, false); + CXXRecordDecl *DstTy; + Ty = CastTy.getTypePtr()->getPointeeType(); + CanTy = CGM.getContext().getCanonicalType(Ty); + Ty = CanTy.getUnqualifiedType(); + DstTy = cast<CXXRecordDecl>(Ty->getAs<RecordType>()->getDecl()); + + // FIXME: Calculate better hint. + llvm::Value *hint = llvm::ConstantInt::get(PtrDiffTy, -1ULL); + llvm::Value *SrcArg = CGM.GenerateRttiRef(SrcTy); + llvm::Value *DstArg = CGM.GenerateRttiRef(DstTy); + V = Builder.CreateBitCast(V, PtrToInt8Ty); + V = Builder.CreateCall4(CGM.CreateRuntimeFunction(FTy, "__dynamic_cast"), + V, SrcArg, DstArg, hint); + V = Builder.CreateBitCast(V, LTy); + + if (ThrowOnBad) { + BadCastBlock = createBasicBlock(); + + llvm::Value *Zero = llvm::Constant::getNullValue(LTy); + Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero), + ContBlock, BadCastBlock); + EmitBlock(BadCastBlock); + /// Call __cxa_bad_cast + ResultType = llvm::Type::getVoidTy(VMContext); + const llvm::FunctionType *FBadTy; + FBadTy = llvm::FunctionType::get(ResultType, false); + llvm::Value *F = CGM.CreateRuntimeFunction(FBadTy, "__cxa_bad_cast"); + Builder.CreateCall(F)->setDoesNotReturn(); + Builder.CreateUnreachable(); + } + } + + if (CanBeZero) { + Builder.CreateBr(ContBlock); + EmitBlock(NullBlock); + Builder.CreateBr(ContBlock); + } + EmitBlock(ContBlock); + if (CanBeZero) { + llvm::PHINode *PHI = Builder.CreatePHI(LTy); + PHI->reserveOperandSpace(2); + PHI->addIncoming(V, NonZeroBlock); + PHI->addIncoming(llvm::Constant::getNullValue(LTy), NullBlock); + V = PHI; + } + + return V; +} |
