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Diffstat (limited to 'clang/lib/CodeGen/CGExprCXX.cpp')
| -rw-r--r-- | clang/lib/CodeGen/CGExprCXX.cpp | 1833 |
1 files changed, 1833 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp new file mode 100644 index 0000000..c69c883 --- /dev/null +++ b/clang/lib/CodeGen/CGExprCXX.cpp @@ -0,0 +1,1833 @@ +//===--- 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 "clang/Frontend/CodeGenOptions.h" +#include "CodeGenFunction.h" +#include "CGCUDARuntime.h" +#include "CGCXXABI.h" +#include "CGObjCRuntime.h" +#include "CGDebugInfo.h" +#include "llvm/Intrinsics.h" +#include "llvm/Support/CallSite.h" + +using namespace clang; +using namespace CodeGen; + +RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD, + llvm::Value *Callee, + ReturnValueSlot ReturnValue, + llvm::Value *This, + llvm::Value *VTT, + CallExpr::const_arg_iterator ArgBeg, + CallExpr::const_arg_iterator ArgEnd) { + assert(MD->isInstance() && + "Trying to emit a member call expr on a static method!"); + + CallArgList Args; + + // Push the this ptr. + Args.add(RValue::get(This), MD->getThisType(getContext())); + + // If there is a VTT parameter, emit it. + if (VTT) { + QualType T = getContext().getPointerType(getContext().VoidPtrTy); + Args.add(RValue::get(VTT), T); + } + + const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); + RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size()); + + // And the rest of the call args. + EmitCallArgs(Args, FPT, ArgBeg, ArgEnd); + + return EmitCall(CGM.getTypes().arrangeFunctionCall(FPT->getResultType(), Args, + FPT->getExtInfo(), + required), + Callee, ReturnValue, Args, MD); +} + +static const CXXRecordDecl *getMostDerivedClassDecl(const Expr *Base) { + const Expr *E = Base; + + while (true) { + E = E->IgnoreParens(); + if (const CastExpr *CE = dyn_cast<CastExpr>(E)) { + if (CE->getCastKind() == CK_DerivedToBase || + CE->getCastKind() == CK_UncheckedDerivedToBase || + CE->getCastKind() == CK_NoOp) { + E = CE->getSubExpr(); + continue; + } + } + + break; + } + + QualType DerivedType = E->getType(); + if (const PointerType *PTy = DerivedType->getAs<PointerType>()) + DerivedType = PTy->getPointeeType(); + + return cast<CXXRecordDecl>(DerivedType->castAs<RecordType>()->getDecl()); +} + +// FIXME: Ideally Expr::IgnoreParenNoopCasts should do this, but it doesn't do +// quite what we want. +static const Expr *skipNoOpCastsAndParens(const Expr *E) { + while (true) { + if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) { + E = PE->getSubExpr(); + continue; + } + + if (const CastExpr *CE = dyn_cast<CastExpr>(E)) { + if (CE->getCastKind() == CK_NoOp) { + E = CE->getSubExpr(); + continue; + } + } + if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { + if (UO->getOpcode() == UO_Extension) { + E = UO->getSubExpr(); + continue; + } + } + return E; + } +} + +/// canDevirtualizeMemberFunctionCalls - Checks whether virtual calls on given +/// expr can be devirtualized. +static bool canDevirtualizeMemberFunctionCalls(ASTContext &Context, + const Expr *Base, + const CXXMethodDecl *MD) { + + // When building with -fapple-kext, all calls must go through the vtable since + // the kernel linker can do runtime patching of vtables. + if (Context.getLangOpts().AppleKext) + return false; + + // If the most derived class is marked final, we know that no subclass can + // override this member function and so we can devirtualize it. For example: + // + // struct A { virtual void f(); } + // struct B final : A { }; + // + // void f(B *b) { + // b->f(); + // } + // + const CXXRecordDecl *MostDerivedClassDecl = getMostDerivedClassDecl(Base); + if (MostDerivedClassDecl->hasAttr<FinalAttr>()) + return true; + + // If the member function is marked 'final', we know that it can't be + // overridden and can therefore devirtualize it. + if (MD->hasAttr<FinalAttr>()) + return true; + + // Similarly, if the class itself is marked 'final' it can't be overridden + // and we can therefore devirtualize the member function call. + if (MD->getParent()->hasAttr<FinalAttr>()) + return true; + + Base = skipNoOpCastsAndParens(Base); + if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) { + if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) { + // This is a record decl. We know the type and can devirtualize it. + return VD->getType()->isRecordType(); + } + + return false; + } + + // We can always devirtualize calls on temporary object expressions. + if (isa<CXXConstructExpr>(Base)) + return true; + + // And calls on bound temporaries. + if (isa<CXXBindTemporaryExpr>(Base)) + return true; + + // Check if this is a call expr that returns a record type. + if (const CallExpr *CE = dyn_cast<CallExpr>(Base)) + return CE->getCallReturnType()->isRecordType(); + + // We can't devirtualize the call. + return false; +} + +// Note: This function also emit constructor calls to support a MSVC +// extensions allowing explicit constructor function call. +RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE, + ReturnValueSlot ReturnValue) { + const Expr *callee = CE->getCallee()->IgnoreParens(); + + if (isa<BinaryOperator>(callee)) + return EmitCXXMemberPointerCallExpr(CE, ReturnValue); + + const MemberExpr *ME = cast<MemberExpr>(callee); + const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl()); + + CGDebugInfo *DI = getDebugInfo(); + if (DI && CGM.getCodeGenOpts().LimitDebugInfo + && !isa<CallExpr>(ME->getBase())) { + QualType PQTy = ME->getBase()->IgnoreParenImpCasts()->getType(); + if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) { + DI->getOrCreateRecordType(PTy->getPointeeType(), + MD->getParent()->getLocation()); + } + } + + if (MD->isStatic()) { + // The method is static, emit it as we would a regular call. + llvm::Value *Callee = CGM.GetAddrOfFunction(MD); + return EmitCall(getContext().getPointerType(MD->getType()), Callee, + ReturnValue, CE->arg_begin(), CE->arg_end()); + } + + // Compute the object pointer. + llvm::Value *This; + if (ME->isArrow()) + This = EmitScalarExpr(ME->getBase()); + else + This = EmitLValue(ME->getBase()).getAddress(); + + if (MD->isTrivial()) { + if (isa<CXXDestructorDecl>(MD)) return RValue::get(0); + if (isa<CXXConstructorDecl>(MD) && + cast<CXXConstructorDecl>(MD)->isDefaultConstructor()) + return RValue::get(0); + + if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) { + // We don't like to generate the trivial copy/move assignment operator + // when it isn't necessary; just produce the proper effect here. + llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress(); + EmitAggregateCopy(This, RHS, CE->getType()); + return RValue::get(This); + } + + if (isa<CXXConstructorDecl>(MD) && + cast<CXXConstructorDecl>(MD)->isCopyOrMoveConstructor()) { + // Trivial move and copy ctor are the same. + llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress(); + EmitSynthesizedCXXCopyCtorCall(cast<CXXConstructorDecl>(MD), This, RHS, + CE->arg_begin(), CE->arg_end()); + return RValue::get(This); + } + llvm_unreachable("unknown trivial member function"); + } + + // Compute the function type we're calling. + const CGFunctionInfo *FInfo = 0; + if (isa<CXXDestructorDecl>(MD)) + FInfo = &CGM.getTypes().arrangeCXXDestructor(cast<CXXDestructorDecl>(MD), + Dtor_Complete); + else if (isa<CXXConstructorDecl>(MD)) + FInfo = &CGM.getTypes().arrangeCXXConstructorDeclaration( + cast<CXXConstructorDecl>(MD), + Ctor_Complete); + else + FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(MD); + + llvm::Type *Ty = CGM.getTypes().GetFunctionType(*FInfo); + + // C++ [class.virtual]p12: + // Explicit qualification with the scope operator (5.1) suppresses the + // virtual call mechanism. + // + // We also don't emit a virtual call if the base expression has a record type + // because then we know what the type is. + bool UseVirtualCall; + UseVirtualCall = MD->isVirtual() && !ME->hasQualifier() + && !canDevirtualizeMemberFunctionCalls(getContext(), + ME->getBase(), MD); + llvm::Value *Callee; + if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) { + if (UseVirtualCall) { + Callee = BuildVirtualCall(Dtor, Dtor_Complete, This, Ty); + } else { + if (getContext().getLangOpts().AppleKext && + MD->isVirtual() && + ME->hasQualifier()) + Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty); + else + Callee = CGM.GetAddrOfFunction(GlobalDecl(Dtor, Dtor_Complete), Ty); + } + } else if (const CXXConstructorDecl *Ctor = + dyn_cast<CXXConstructorDecl>(MD)) { + Callee = CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty); + } else if (UseVirtualCall) { + Callee = BuildVirtualCall(MD, This, Ty); + } else { + if (getContext().getLangOpts().AppleKext && + MD->isVirtual() && + ME->hasQualifier()) + Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty); + else + Callee = CGM.GetAddrOfFunction(MD, Ty); + } + + return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0, + CE->arg_begin(), CE->arg_end()); +} + +RValue +CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E, + ReturnValueSlot ReturnValue) { + const BinaryOperator *BO = + cast<BinaryOperator>(E->getCallee()->IgnoreParens()); + const Expr *BaseExpr = BO->getLHS(); + const Expr *MemFnExpr = BO->getRHS(); + + const MemberPointerType *MPT = + MemFnExpr->getType()->castAs<MemberPointerType>(); + + const FunctionProtoType *FPT = + MPT->getPointeeType()->castAs<FunctionProtoType>(); + const CXXRecordDecl *RD = + cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl()); + + // Get the member function pointer. + llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr); + + // Emit the 'this' pointer. + llvm::Value *This; + + if (BO->getOpcode() == BO_PtrMemI) + This = EmitScalarExpr(BaseExpr); + else + This = EmitLValue(BaseExpr).getAddress(); + + // Ask the ABI to load the callee. Note that This is modified. + llvm::Value *Callee = + CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, This, MemFnPtr, MPT); + + CallArgList Args; + + QualType ThisType = + getContext().getPointerType(getContext().getTagDeclType(RD)); + + // Push the this ptr. + Args.add(RValue::get(This), ThisType); + + // And the rest of the call args + EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end()); + return EmitCall(CGM.getTypes().arrangeFunctionCall(Args, FPT), Callee, + ReturnValue, Args); +} + +RValue +CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E, + const CXXMethodDecl *MD, + ReturnValueSlot ReturnValue) { + assert(MD->isInstance() && + "Trying to emit a member call expr on a static method!"); + LValue LV = EmitLValue(E->getArg(0)); + llvm::Value *This = LV.getAddress(); + + if ((MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) && + MD->isTrivial()) { + llvm::Value *Src = EmitLValue(E->getArg(1)).getAddress(); + QualType Ty = E->getType(); + EmitAggregateCopy(This, Src, Ty); + return RValue::get(This); + } + + llvm::Value *Callee = EmitCXXOperatorMemberCallee(E, MD, This); + return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0, + E->arg_begin() + 1, E->arg_end()); +} + +RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E, + ReturnValueSlot ReturnValue) { + return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue); +} + +static void EmitNullBaseClassInitialization(CodeGenFunction &CGF, + llvm::Value *DestPtr, + const CXXRecordDecl *Base) { + if (Base->isEmpty()) + return; + + DestPtr = CGF.EmitCastToVoidPtr(DestPtr); + + const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base); + CharUnits Size = Layout.getNonVirtualSize(); + CharUnits Align = Layout.getNonVirtualAlign(); + + llvm::Value *SizeVal = CGF.CGM.getSize(Size); + + // If the type contains a pointer to data member we can't memset it to zero. + // Instead, create a null constant and copy it to the destination. + // TODO: there are other patterns besides zero that we can usefully memset, + // like -1, which happens to be the pattern used by member-pointers. + // TODO: isZeroInitializable can be over-conservative in the case where a + // virtual base contains a member pointer. + if (!CGF.CGM.getTypes().isZeroInitializable(Base)) { + llvm::Constant *NullConstant = CGF.CGM.EmitNullConstantForBase(Base); + + llvm::GlobalVariable *NullVariable = + new llvm::GlobalVariable(CGF.CGM.getModule(), NullConstant->getType(), + /*isConstant=*/true, + llvm::GlobalVariable::PrivateLinkage, + NullConstant, Twine()); + NullVariable->setAlignment(Align.getQuantity()); + llvm::Value *SrcPtr = CGF.EmitCastToVoidPtr(NullVariable); + + // Get and call the appropriate llvm.memcpy overload. + CGF.Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity()); + return; + } + + // Otherwise, just memset the whole thing to zero. This is legal + // because in LLVM, all default initializers (other than the ones we just + // handled above) are guaranteed to have a bit pattern of all zeros. + CGF.Builder.CreateMemSet(DestPtr, CGF.Builder.getInt8(0), SizeVal, + Align.getQuantity()); +} + +void +CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E, + AggValueSlot Dest) { + assert(!Dest.isIgnored() && "Must have a destination!"); + const CXXConstructorDecl *CD = E->getConstructor(); + + // If we require zero initialization before (or instead of) calling the + // constructor, as can be the case with a non-user-provided default + // constructor, emit the zero initialization now, unless destination is + // already zeroed. + if (E->requiresZeroInitialization() && !Dest.isZeroed()) { + switch (E->getConstructionKind()) { + case CXXConstructExpr::CK_Delegating: + assert(0 && "Delegating constructor should not need zeroing"); + case CXXConstructExpr::CK_Complete: + EmitNullInitialization(Dest.getAddr(), E->getType()); + break; + case CXXConstructExpr::CK_VirtualBase: + case CXXConstructExpr::CK_NonVirtualBase: + EmitNullBaseClassInitialization(*this, Dest.getAddr(), CD->getParent()); + break; + } + } + + // If this is a call to a trivial default constructor, do nothing. + if (CD->isTrivial() && CD->isDefaultConstructor()) + return; + + // Elide the constructor if we're constructing from a temporary. + // The temporary check is required because Sema sets this on NRVO + // returns. + if (getContext().getLangOpts().ElideConstructors && E->isElidable()) { + assert(getContext().hasSameUnqualifiedType(E->getType(), + E->getArg(0)->getType())); + if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) { + EmitAggExpr(E->getArg(0), Dest); + return; + } + } + + if (const ConstantArrayType *arrayType + = getContext().getAsConstantArrayType(E->getType())) { + EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddr(), + E->arg_begin(), E->arg_end()); + } else { + CXXCtorType Type = Ctor_Complete; + bool ForVirtualBase = false; + + switch (E->getConstructionKind()) { + case CXXConstructExpr::CK_Delegating: + // We should be emitting a constructor; GlobalDecl will assert this + Type = CurGD.getCtorType(); + break; + + case CXXConstructExpr::CK_Complete: + Type = Ctor_Complete; + break; + + case CXXConstructExpr::CK_VirtualBase: + ForVirtualBase = true; + // fall-through + + case CXXConstructExpr::CK_NonVirtualBase: + Type = Ctor_Base; + } + + // Call the constructor. + EmitCXXConstructorCall(CD, Type, ForVirtualBase, Dest.getAddr(), + E->arg_begin(), E->arg_end()); + } +} + +void +CodeGenFunction::EmitSynthesizedCXXCopyCtor(llvm::Value *Dest, + llvm::Value *Src, + const Expr *Exp) { + if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp)) + Exp = E->getSubExpr(); + assert(isa<CXXConstructExpr>(Exp) && + "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr"); + const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp); + const CXXConstructorDecl *CD = E->getConstructor(); + RunCleanupsScope Scope(*this); + + // If we require zero initialization before (or instead of) calling the + // constructor, as can be the case with a non-user-provided default + // constructor, emit the zero initialization now. + // FIXME. Do I still need this for a copy ctor synthesis? + if (E->requiresZeroInitialization()) + EmitNullInitialization(Dest, E->getType()); + + assert(!getContext().getAsConstantArrayType(E->getType()) + && "EmitSynthesizedCXXCopyCtor - Copied-in Array"); + EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, + E->arg_begin(), E->arg_end()); +} + +static CharUnits CalculateCookiePadding(CodeGenFunction &CGF, + const CXXNewExpr *E) { + if (!E->isArray()) + return CharUnits::Zero(); + + // No cookie is required if the operator new[] being used is the + // reserved placement operator new[]. + if (E->getOperatorNew()->isReservedGlobalPlacementOperator()) + return CharUnits::Zero(); + + return CGF.CGM.getCXXABI().GetArrayCookieSize(E); +} + +static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF, + const CXXNewExpr *e, + unsigned minElements, + llvm::Value *&numElements, + llvm::Value *&sizeWithoutCookie) { + QualType type = e->getAllocatedType(); + + if (!e->isArray()) { + CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type); + sizeWithoutCookie + = llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity()); + return sizeWithoutCookie; + } + + // The width of size_t. + unsigned sizeWidth = CGF.SizeTy->getBitWidth(); + + // Figure out the cookie size. + llvm::APInt cookieSize(sizeWidth, + CalculateCookiePadding(CGF, e).getQuantity()); + + // Emit the array size expression. + // We multiply the size of all dimensions for NumElements. + // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6. + numElements = CGF.EmitScalarExpr(e->getArraySize()); + assert(isa<llvm::IntegerType>(numElements->getType())); + + // The number of elements can be have an arbitrary integer type; + // essentially, we need to multiply it by a constant factor, add a + // cookie size, and verify that the result is representable as a + // size_t. That's just a gloss, though, and it's wrong in one + // important way: if the count is negative, it's an error even if + // the cookie size would bring the total size >= 0. + bool isSigned + = e->getArraySize()->getType()->isSignedIntegerOrEnumerationType(); + llvm::IntegerType *numElementsType + = cast<llvm::IntegerType>(numElements->getType()); + unsigned numElementsWidth = numElementsType->getBitWidth(); + + // Compute the constant factor. + llvm::APInt arraySizeMultiplier(sizeWidth, 1); + while (const ConstantArrayType *CAT + = CGF.getContext().getAsConstantArrayType(type)) { + type = CAT->getElementType(); + arraySizeMultiplier *= CAT->getSize(); + } + + CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type); + llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity()); + typeSizeMultiplier *= arraySizeMultiplier; + + // This will be a size_t. + llvm::Value *size; + + // If someone is doing 'new int[42]' there is no need to do a dynamic check. + // Don't bloat the -O0 code. + if (llvm::ConstantInt *numElementsC = + dyn_cast<llvm::ConstantInt>(numElements)) { + const llvm::APInt &count = numElementsC->getValue(); + + bool hasAnyOverflow = false; + + // If 'count' was a negative number, it's an overflow. + if (isSigned && count.isNegative()) + hasAnyOverflow = true; + + // We want to do all this arithmetic in size_t. If numElements is + // wider than that, check whether it's already too big, and if so, + // overflow. + else if (numElementsWidth > sizeWidth && + numElementsWidth - sizeWidth > count.countLeadingZeros()) + hasAnyOverflow = true; + + // Okay, compute a count at the right width. + llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth); + + // If there is a brace-initializer, we cannot allocate fewer elements than + // there are initializers. If we do, that's treated like an overflow. + if (adjustedCount.ult(minElements)) + hasAnyOverflow = true; + + // Scale numElements by that. This might overflow, but we don't + // care because it only overflows if allocationSize does, too, and + // if that overflows then we shouldn't use this. + numElements = llvm::ConstantInt::get(CGF.SizeTy, + adjustedCount * arraySizeMultiplier); + + // Compute the size before cookie, and track whether it overflowed. + bool overflow; + llvm::APInt allocationSize + = adjustedCount.umul_ov(typeSizeMultiplier, overflow); + hasAnyOverflow |= overflow; + + // Add in the cookie, and check whether it's overflowed. + if (cookieSize != 0) { + // Save the current size without a cookie. This shouldn't be + // used if there was overflow. + sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize); + + allocationSize = allocationSize.uadd_ov(cookieSize, overflow); + hasAnyOverflow |= overflow; + } + + // On overflow, produce a -1 so operator new will fail. + if (hasAnyOverflow) { + size = llvm::Constant::getAllOnesValue(CGF.SizeTy); + } else { + size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize); + } + + // Otherwise, we might need to use the overflow intrinsics. + } else { + // There are up to five conditions we need to test for: + // 1) if isSigned, we need to check whether numElements is negative; + // 2) if numElementsWidth > sizeWidth, we need to check whether + // numElements is larger than something representable in size_t; + // 3) if minElements > 0, we need to check whether numElements is smaller + // than that. + // 4) we need to compute + // sizeWithoutCookie := numElements * typeSizeMultiplier + // and check whether it overflows; and + // 5) if we need a cookie, we need to compute + // size := sizeWithoutCookie + cookieSize + // and check whether it overflows. + + llvm::Value *hasOverflow = 0; + + // If numElementsWidth > sizeWidth, then one way or another, we're + // going to have to do a comparison for (2), and this happens to + // take care of (1), too. + if (numElementsWidth > sizeWidth) { + llvm::APInt threshold(numElementsWidth, 1); + threshold <<= sizeWidth; + + llvm::Value *thresholdV + = llvm::ConstantInt::get(numElementsType, threshold); + + hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV); + numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy); + + // Otherwise, if we're signed, we want to sext up to size_t. + } else if (isSigned) { + if (numElementsWidth < sizeWidth) + numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy); + + // If there's a non-1 type size multiplier, then we can do the + // signedness check at the same time as we do the multiply + // because a negative number times anything will cause an + // unsigned overflow. Otherwise, we have to do it here. But at least + // in this case, we can subsume the >= minElements check. + if (typeSizeMultiplier == 1) + hasOverflow = CGF.Builder.CreateICmpSLT(numElements, + llvm::ConstantInt::get(CGF.SizeTy, minElements)); + + // Otherwise, zext up to size_t if necessary. + } else if (numElementsWidth < sizeWidth) { + numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy); + } + + assert(numElements->getType() == CGF.SizeTy); + + if (minElements) { + // Don't allow allocation of fewer elements than we have initializers. + if (!hasOverflow) { + hasOverflow = CGF.Builder.CreateICmpULT(numElements, + llvm::ConstantInt::get(CGF.SizeTy, minElements)); + } else if (numElementsWidth > sizeWidth) { + // The other existing overflow subsumes this check. + // We do an unsigned comparison, since any signed value < -1 is + // taken care of either above or below. + hasOverflow = CGF.Builder.CreateOr(hasOverflow, + CGF.Builder.CreateICmpULT(numElements, + llvm::ConstantInt::get(CGF.SizeTy, minElements))); + } + } + + size = numElements; + + // Multiply by the type size if necessary. This multiplier + // includes all the factors for nested arrays. + // + // This step also causes numElements to be scaled up by the + // nested-array factor if necessary. Overflow on this computation + // can be ignored because the result shouldn't be used if + // allocation fails. + if (typeSizeMultiplier != 1) { + llvm::Value *umul_with_overflow + = CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy); + + llvm::Value *tsmV = + llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier); + llvm::Value *result = + CGF.Builder.CreateCall2(umul_with_overflow, size, tsmV); + + llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1); + if (hasOverflow) + hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed); + else + hasOverflow = overflowed; + + size = CGF.Builder.CreateExtractValue(result, 0); + + // Also scale up numElements by the array size multiplier. + if (arraySizeMultiplier != 1) { + // If the base element type size is 1, then we can re-use the + // multiply we just did. + if (typeSize.isOne()) { + assert(arraySizeMultiplier == typeSizeMultiplier); + numElements = size; + + // Otherwise we need a separate multiply. + } else { + llvm::Value *asmV = + llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier); + numElements = CGF.Builder.CreateMul(numElements, asmV); + } + } + } else { + // numElements doesn't need to be scaled. + assert(arraySizeMultiplier == 1); + } + + // Add in the cookie size if necessary. + if (cookieSize != 0) { + sizeWithoutCookie = size; + + llvm::Value *uadd_with_overflow + = CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy); + + llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize); + llvm::Value *result = + CGF.Builder.CreateCall2(uadd_with_overflow, size, cookieSizeV); + + llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1); + if (hasOverflow) + hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed); + else + hasOverflow = overflowed; + + size = CGF.Builder.CreateExtractValue(result, 0); + } + + // If we had any possibility of dynamic overflow, make a select to + // overwrite 'size' with an all-ones value, which should cause + // operator new to throw. + if (hasOverflow) + size = CGF.Builder.CreateSelect(hasOverflow, + llvm::Constant::getAllOnesValue(CGF.SizeTy), + size); + } + + if (cookieSize == 0) + sizeWithoutCookie = size; + else + assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?"); + + return size; +} + +static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init, + QualType AllocType, llvm::Value *NewPtr) { + + CharUnits Alignment = CGF.getContext().getTypeAlignInChars(AllocType); + if (!CGF.hasAggregateLLVMType(AllocType)) + CGF.EmitScalarInit(Init, 0, CGF.MakeAddrLValue(NewPtr, AllocType, + Alignment), + false); + else if (AllocType->isAnyComplexType()) + CGF.EmitComplexExprIntoAddr(Init, NewPtr, + AllocType.isVolatileQualified()); + else { + AggValueSlot Slot + = AggValueSlot::forAddr(NewPtr, Alignment, AllocType.getQualifiers(), + AggValueSlot::IsDestructed, + AggValueSlot::DoesNotNeedGCBarriers, + AggValueSlot::IsNotAliased); + CGF.EmitAggExpr(Init, Slot); + + CGF.MaybeEmitStdInitializerListCleanup(NewPtr, Init); + } +} + +void +CodeGenFunction::EmitNewArrayInitializer(const CXXNewExpr *E, + QualType elementType, + llvm::Value *beginPtr, + llvm::Value *numElements) { + if (!E->hasInitializer()) + return; // We have a POD type. + + llvm::Value *explicitPtr = beginPtr; + // Find the end of the array, hoisted out of the loop. + llvm::Value *endPtr = + Builder.CreateInBoundsGEP(beginPtr, numElements, "array.end"); + + unsigned initializerElements = 0; + + const Expr *Init = E->getInitializer(); + llvm::AllocaInst *endOfInit = 0; + QualType::DestructionKind dtorKind = elementType.isDestructedType(); + EHScopeStack::stable_iterator cleanup; + llvm::Instruction *cleanupDominator = 0; + // If the initializer is an initializer list, first do the explicit elements. + if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { + initializerElements = ILE->getNumInits(); + + // Enter a partial-destruction cleanup if necessary. + if (needsEHCleanup(dtorKind)) { + // In principle we could tell the cleanup where we are more + // directly, but the control flow can get so varied here that it + // would actually be quite complex. Therefore we go through an + // alloca. + endOfInit = CreateTempAlloca(beginPtr->getType(), "array.endOfInit"); + cleanupDominator = Builder.CreateStore(beginPtr, endOfInit); + pushIrregularPartialArrayCleanup(beginPtr, endOfInit, elementType, + getDestroyer(dtorKind)); + cleanup = EHStack.stable_begin(); + } + + for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) { + // Tell the cleanup that it needs to destroy up to this + // element. TODO: some of these stores can be trivially + // observed to be unnecessary. + if (endOfInit) Builder.CreateStore(explicitPtr, endOfInit); + StoreAnyExprIntoOneUnit(*this, ILE->getInit(i), elementType, explicitPtr); + explicitPtr =Builder.CreateConstGEP1_32(explicitPtr, 1, "array.exp.next"); + } + + // The remaining elements are filled with the array filler expression. + Init = ILE->getArrayFiller(); + } + + // Create the continuation block. + llvm::BasicBlock *contBB = createBasicBlock("new.loop.end"); + + // If the number of elements isn't constant, we have to now check if there is + // anything left to initialize. + if (llvm::ConstantInt *constNum = dyn_cast<llvm::ConstantInt>(numElements)) { + // If all elements have already been initialized, skip the whole loop. + if (constNum->getZExtValue() <= initializerElements) { + // If there was a cleanup, deactivate it. + if (cleanupDominator) + DeactivateCleanupBlock(cleanup, cleanupDominator);; + return; + } + } else { + llvm::BasicBlock *nonEmptyBB = createBasicBlock("new.loop.nonempty"); + llvm::Value *isEmpty = Builder.CreateICmpEQ(explicitPtr, endPtr, + "array.isempty"); + Builder.CreateCondBr(isEmpty, contBB, nonEmptyBB); + EmitBlock(nonEmptyBB); + } + + // Enter the loop. + llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); + llvm::BasicBlock *loopBB = createBasicBlock("new.loop"); + + EmitBlock(loopBB); + + // Set up the current-element phi. + llvm::PHINode *curPtr = + Builder.CreatePHI(explicitPtr->getType(), 2, "array.cur"); + curPtr->addIncoming(explicitPtr, entryBB); + + // Store the new cleanup position for irregular cleanups. + if (endOfInit) Builder.CreateStore(curPtr, endOfInit); + + // Enter a partial-destruction cleanup if necessary. + if (!cleanupDominator && needsEHCleanup(dtorKind)) { + pushRegularPartialArrayCleanup(beginPtr, curPtr, elementType, + getDestroyer(dtorKind)); + cleanup = EHStack.stable_begin(); + cleanupDominator = Builder.CreateUnreachable(); + } + + // Emit the initializer into this element. + StoreAnyExprIntoOneUnit(*this, Init, E->getAllocatedType(), curPtr); + + // Leave the cleanup if we entered one. + if (cleanupDominator) { + DeactivateCleanupBlock(cleanup, cleanupDominator); + cleanupDominator->eraseFromParent(); + } + + // Advance to the next element. + llvm::Value *nextPtr = Builder.CreateConstGEP1_32(curPtr, 1, "array.next"); + + // Check whether we've gotten to the end of the array and, if so, + // exit the loop. + llvm::Value *isEnd = Builder.CreateICmpEQ(nextPtr, endPtr, "array.atend"); + Builder.CreateCondBr(isEnd, contBB, loopBB); + curPtr->addIncoming(nextPtr, Builder.GetInsertBlock()); + + EmitBlock(contBB); +} + +static void EmitZeroMemSet(CodeGenFunction &CGF, QualType T, + llvm::Value *NewPtr, llvm::Value *Size) { + CGF.EmitCastToVoidPtr(NewPtr); + CharUnits Alignment = CGF.getContext().getTypeAlignInChars(T); + CGF.Builder.CreateMemSet(NewPtr, CGF.Builder.getInt8(0), Size, + Alignment.getQuantity(), false); +} + +static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E, + QualType ElementType, + llvm::Value *NewPtr, + llvm::Value *NumElements, + llvm::Value *AllocSizeWithoutCookie) { + const Expr *Init = E->getInitializer(); + if (E->isArray()) { + if (const CXXConstructExpr *CCE = dyn_cast_or_null<CXXConstructExpr>(Init)){ + CXXConstructorDecl *Ctor = CCE->getConstructor(); + bool RequiresZeroInitialization = false; + if (Ctor->isTrivial()) { + // If new expression did not specify value-initialization, then there + // is no initialization. + if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty()) + return; + + if (CGF.CGM.getTypes().isZeroInitializable(ElementType)) { + // Optimization: since zero initialization will just set the memory + // to all zeroes, generate a single memset to do it in one shot. + EmitZeroMemSet(CGF, ElementType, NewPtr, AllocSizeWithoutCookie); + return; + } + + RequiresZeroInitialization = true; + } + + CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr, + CCE->arg_begin(), CCE->arg_end(), + RequiresZeroInitialization); + return; + } else if (Init && isa<ImplicitValueInitExpr>(Init) && + CGF.CGM.getTypes().isZeroInitializable(ElementType)) { + // Optimization: since zero initialization will just set the memory + // to all zeroes, generate a single memset to do it in one shot. + EmitZeroMemSet(CGF, ElementType, NewPtr, AllocSizeWithoutCookie); + return; + } + CGF.EmitNewArrayInitializer(E, ElementType, NewPtr, NumElements); + return; + } + + if (!Init) + return; + + StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr); +} + +namespace { + /// A cleanup to call the given 'operator delete' function upon + /// abnormal exit from a new expression. + class CallDeleteDuringNew : public EHScopeStack::Cleanup { + size_t NumPlacementArgs; + const FunctionDecl *OperatorDelete; + llvm::Value *Ptr; + llvm::Value *AllocSize; + + RValue *getPlacementArgs() { return reinterpret_cast<RValue*>(this+1); } + + public: + static size_t getExtraSize(size_t NumPlacementArgs) { + return NumPlacementArgs * sizeof(RValue); + } + + CallDeleteDuringNew(size_t NumPlacementArgs, + const FunctionDecl *OperatorDelete, + llvm::Value *Ptr, + llvm::Value *AllocSize) + : NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete), + Ptr(Ptr), AllocSize(AllocSize) {} + + void setPlacementArg(unsigned I, RValue Arg) { + assert(I < NumPlacementArgs && "index out of range"); + getPlacementArgs()[I] = Arg; + } + + void Emit(CodeGenFunction &CGF, Flags flags) { + const FunctionProtoType *FPT + = OperatorDelete->getType()->getAs<FunctionProtoType>(); + assert(FPT->getNumArgs() == NumPlacementArgs + 1 || + (FPT->getNumArgs() == 2 && NumPlacementArgs == 0)); + + CallArgList DeleteArgs; + + // The first argument is always a void*. + FunctionProtoType::arg_type_iterator AI = FPT->arg_type_begin(); + DeleteArgs.add(RValue::get(Ptr), *AI++); + + // A member 'operator delete' can take an extra 'size_t' argument. + if (FPT->getNumArgs() == NumPlacementArgs + 2) + DeleteArgs.add(RValue::get(AllocSize), *AI++); + + // Pass the rest of the arguments, which must match exactly. + for (unsigned I = 0; I != NumPlacementArgs; ++I) + DeleteArgs.add(getPlacementArgs()[I], *AI++); + + // Call 'operator delete'. + CGF.EmitCall(CGF.CGM.getTypes().arrangeFunctionCall(DeleteArgs, FPT), + CGF.CGM.GetAddrOfFunction(OperatorDelete), + ReturnValueSlot(), DeleteArgs, OperatorDelete); + } + }; + + /// A cleanup to call the given 'operator delete' function upon + /// abnormal exit from a new expression when the new expression is + /// conditional. + class CallDeleteDuringConditionalNew : public EHScopeStack::Cleanup { + size_t NumPlacementArgs; + const FunctionDecl *OperatorDelete; + DominatingValue<RValue>::saved_type Ptr; + DominatingValue<RValue>::saved_type AllocSize; + + DominatingValue<RValue>::saved_type *getPlacementArgs() { + return reinterpret_cast<DominatingValue<RValue>::saved_type*>(this+1); + } + + public: + static size_t getExtraSize(size_t NumPlacementArgs) { + return NumPlacementArgs * sizeof(DominatingValue<RValue>::saved_type); + } + + CallDeleteDuringConditionalNew(size_t NumPlacementArgs, + const FunctionDecl *OperatorDelete, + DominatingValue<RValue>::saved_type Ptr, + DominatingValue<RValue>::saved_type AllocSize) + : NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete), + Ptr(Ptr), AllocSize(AllocSize) {} + + void setPlacementArg(unsigned I, DominatingValue<RValue>::saved_type Arg) { + assert(I < NumPlacementArgs && "index out of range"); + getPlacementArgs()[I] = Arg; + } + + void Emit(CodeGenFunction &CGF, Flags flags) { + const FunctionProtoType *FPT + = OperatorDelete->getType()->getAs<FunctionProtoType>(); + assert(FPT->getNumArgs() == NumPlacementArgs + 1 || + (FPT->getNumArgs() == 2 && NumPlacementArgs == 0)); + + CallArgList DeleteArgs; + + // The first argument is always a void*. + FunctionProtoType::arg_type_iterator AI = FPT->arg_type_begin(); + DeleteArgs.add(Ptr.restore(CGF), *AI++); + + // A member 'operator delete' can take an extra 'size_t' argument. + if (FPT->getNumArgs() == NumPlacementArgs + 2) { + RValue RV = AllocSize.restore(CGF); + DeleteArgs.add(RV, *AI++); + } + + // Pass the rest of the arguments, which must match exactly. + for (unsigned I = 0; I != NumPlacementArgs; ++I) { + RValue RV = getPlacementArgs()[I].restore(CGF); + DeleteArgs.add(RV, *AI++); + } + + // Call 'operator delete'. + CGF.EmitCall(CGF.CGM.getTypes().arrangeFunctionCall(DeleteArgs, FPT), + CGF.CGM.GetAddrOfFunction(OperatorDelete), + ReturnValueSlot(), DeleteArgs, OperatorDelete); + } + }; +} + +/// Enter a cleanup to call 'operator delete' if the initializer in a +/// new-expression throws. +static void EnterNewDeleteCleanup(CodeGenFunction &CGF, + const CXXNewExpr *E, + llvm::Value *NewPtr, + llvm::Value *AllocSize, + const CallArgList &NewArgs) { + // If we're not inside a conditional branch, then the cleanup will + // dominate and we can do the easier (and more efficient) thing. + if (!CGF.isInConditionalBranch()) { + CallDeleteDuringNew *Cleanup = CGF.EHStack + .pushCleanupWithExtra<CallDeleteDuringNew>(EHCleanup, + E->getNumPlacementArgs(), + E->getOperatorDelete(), + NewPtr, AllocSize); + for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) + Cleanup->setPlacementArg(I, NewArgs[I+1].RV); + + return; + } + + // Otherwise, we need to save all this stuff. + DominatingValue<RValue>::saved_type SavedNewPtr = + DominatingValue<RValue>::save(CGF, RValue::get(NewPtr)); + DominatingValue<RValue>::saved_type SavedAllocSize = + DominatingValue<RValue>::save(CGF, RValue::get(AllocSize)); + + CallDeleteDuringConditionalNew *Cleanup = CGF.EHStack + .pushCleanupWithExtra<CallDeleteDuringConditionalNew>(EHCleanup, + E->getNumPlacementArgs(), + E->getOperatorDelete(), + SavedNewPtr, + SavedAllocSize); + for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) + Cleanup->setPlacementArg(I, + DominatingValue<RValue>::save(CGF, NewArgs[I+1].RV)); + + CGF.initFullExprCleanup(); +} + +llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { + // The element type being allocated. + QualType allocType = getContext().getBaseElementType(E->getAllocatedType()); + + // 1. Build a call to the allocation function. + FunctionDecl *allocator = E->getOperatorNew(); + const FunctionProtoType *allocatorType = + allocator->getType()->castAs<FunctionProtoType>(); + + CallArgList allocatorArgs; + + // The allocation size is the first argument. + QualType sizeType = getContext().getSizeType(); + + // If there is a brace-initializer, cannot allocate fewer elements than inits. + unsigned minElements = 0; + if (E->isArray() && E->hasInitializer()) { + if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer())) + minElements = ILE->getNumInits(); + } + + llvm::Value *numElements = 0; + llvm::Value *allocSizeWithoutCookie = 0; + llvm::Value *allocSize = + EmitCXXNewAllocSize(*this, E, minElements, numElements, + allocSizeWithoutCookie); + + allocatorArgs.add(RValue::get(allocSize), sizeType); + + // Emit the rest of the arguments. + // FIXME: Ideally, this should just use EmitCallArgs. + CXXNewExpr::const_arg_iterator placementArg = 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 = allocatorType->getNumArgs(); i != e; + ++i, ++placementArg) { + QualType argType = allocatorType->getArgType(i); + + assert(getContext().hasSameUnqualifiedType(argType.getNonReferenceType(), + placementArg->getType()) && + "type mismatch in call argument!"); + + EmitCallArg(allocatorArgs, *placementArg, argType); + } + + // Either we've emitted all the call args, or we have a call to a + // variadic function. + assert((placementArg == E->placement_arg_end() || + allocatorType->isVariadic()) && + "Extra arguments to non-variadic function!"); + + // If we still have any arguments, emit them using the type of the argument. + for (CXXNewExpr::const_arg_iterator placementArgsEnd = E->placement_arg_end(); + placementArg != placementArgsEnd; ++placementArg) { + EmitCallArg(allocatorArgs, *placementArg, placementArg->getType()); + } + + // Emit the allocation call. If the allocator is a global placement + // operator, just "inline" it directly. + RValue RV; + if (allocator->isReservedGlobalPlacementOperator()) { + assert(allocatorArgs.size() == 2); + RV = allocatorArgs[1].RV; + // TODO: kill any unnecessary computations done for the size + // argument. + } else { + RV = EmitCall(CGM.getTypes().arrangeFunctionCall(allocatorArgs, + allocatorType), + CGM.GetAddrOfFunction(allocator), ReturnValueSlot(), + allocatorArgs, allocator); + } + + // Emit a null check on the allocation result if the allocation + // function is allowed to return null (because it has a non-throwing + // exception spec; for this part, we inline + // CXXNewExpr::shouldNullCheckAllocation()) and we have an + // interesting initializer. + bool nullCheck = allocatorType->isNothrow(getContext()) && + (!allocType.isPODType(getContext()) || E->hasInitializer()); + + llvm::BasicBlock *nullCheckBB = 0; + llvm::BasicBlock *contBB = 0; + + llvm::Value *allocation = RV.getScalarVal(); + unsigned AS = + cast<llvm::PointerType>(allocation->getType())->getAddressSpace(); + + // The null-check means that the initializer is conditionally + // evaluated. + ConditionalEvaluation conditional(*this); + + if (nullCheck) { + conditional.begin(*this); + + nullCheckBB = Builder.GetInsertBlock(); + llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull"); + contBB = createBasicBlock("new.cont"); + + llvm::Value *isNull = Builder.CreateIsNull(allocation, "new.isnull"); + Builder.CreateCondBr(isNull, contBB, notNullBB); + EmitBlock(notNullBB); + } + + // If there's an operator delete, enter a cleanup to call it if an + // exception is thrown. + EHScopeStack::stable_iterator operatorDeleteCleanup; + llvm::Instruction *cleanupDominator = 0; + if (E->getOperatorDelete() && + !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) { + EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocatorArgs); + operatorDeleteCleanup = EHStack.stable_begin(); + cleanupDominator = Builder.CreateUnreachable(); + } + + assert((allocSize == allocSizeWithoutCookie) == + CalculateCookiePadding(*this, E).isZero()); + if (allocSize != allocSizeWithoutCookie) { + assert(E->isArray()); + allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation, + numElements, + E, allocType); + } + + llvm::Type *elementPtrTy + = ConvertTypeForMem(allocType)->getPointerTo(AS); + llvm::Value *result = Builder.CreateBitCast(allocation, elementPtrTy); + + EmitNewInitializer(*this, E, allocType, result, numElements, + allocSizeWithoutCookie); + if (E->isArray()) { + // NewPtr is a pointer to the base element type. If we're + // allocating an array of arrays, we'll need to cast back to the + // array pointer type. + llvm::Type *resultType = ConvertTypeForMem(E->getType()); + if (result->getType() != resultType) + result = Builder.CreateBitCast(result, resultType); + } + + // Deactivate the 'operator delete' cleanup if we finished + // initialization. + if (operatorDeleteCleanup.isValid()) { + DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator); + cleanupDominator->eraseFromParent(); + } + + if (nullCheck) { + conditional.end(*this); + + llvm::BasicBlock *notNullBB = Builder.GetInsertBlock(); + EmitBlock(contBB); + + llvm::PHINode *PHI = Builder.CreatePHI(result->getType(), 2); + PHI->addIncoming(result, notNullBB); + PHI->addIncoming(llvm::Constant::getNullValue(result->getType()), + nullCheckBB); + + result = PHI; + } + + return result; +} + +void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD, + llvm::Value *Ptr, + QualType DeleteTy) { + assert(DeleteFD->getOverloadedOperator() == OO_Delete); + + const FunctionProtoType *DeleteFTy = + DeleteFD->getType()->getAs<FunctionProtoType>(); + + CallArgList DeleteArgs; + + // Check if we need to pass the size to the delete operator. + llvm::Value *Size = 0; + QualType SizeTy; + if (DeleteFTy->getNumArgs() == 2) { + SizeTy = DeleteFTy->getArgType(1); + CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy); + Size = llvm::ConstantInt::get(ConvertType(SizeTy), + DeleteTypeSize.getQuantity()); + } + + QualType ArgTy = DeleteFTy->getArgType(0); + llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy)); + DeleteArgs.add(RValue::get(DeletePtr), ArgTy); + + if (Size) + DeleteArgs.add(RValue::get(Size), SizeTy); + + // Emit the call to delete. + EmitCall(CGM.getTypes().arrangeFunctionCall(DeleteArgs, DeleteFTy), + CGM.GetAddrOfFunction(DeleteFD), ReturnValueSlot(), + DeleteArgs, DeleteFD); +} + +namespace { + /// Calls the given 'operator delete' on a single object. + struct CallObjectDelete : EHScopeStack::Cleanup { + llvm::Value *Ptr; + const FunctionDecl *OperatorDelete; + QualType ElementType; + + CallObjectDelete(llvm::Value *Ptr, + const FunctionDecl *OperatorDelete, + QualType ElementType) + : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {} + + void Emit(CodeGenFunction &CGF, Flags flags) { + CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType); + } + }; +} + +/// Emit the code for deleting a single object. +static void EmitObjectDelete(CodeGenFunction &CGF, + const FunctionDecl *OperatorDelete, + llvm::Value *Ptr, + QualType ElementType, + bool UseGlobalDelete) { + // Find the destructor for the type, if applicable. If the + // destructor is virtual, we'll just emit the vcall and return. + const CXXDestructorDecl *Dtor = 0; + if (const RecordType *RT = ElementType->getAs<RecordType>()) { + CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->hasDefinition() && !RD->hasTrivialDestructor()) { + Dtor = RD->getDestructor(); + + if (Dtor->isVirtual()) { + if (UseGlobalDelete) { + // If we're supposed to call the global delete, make sure we do so + // even if the destructor throws. + CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, + Ptr, OperatorDelete, + ElementType); + } + + llvm::Type *Ty = + CGF.getTypes().GetFunctionType( + CGF.getTypes().arrangeCXXDestructor(Dtor, Dtor_Complete)); + + llvm::Value *Callee + = CGF.BuildVirtualCall(Dtor, + UseGlobalDelete? Dtor_Complete : Dtor_Deleting, + Ptr, Ty); + CGF.EmitCXXMemberCall(Dtor, Callee, ReturnValueSlot(), Ptr, /*VTT=*/0, + 0, 0); + + if (UseGlobalDelete) { + CGF.PopCleanupBlock(); + } + + return; + } + } + } + + // Make sure that we call delete even if the dtor throws. + // This doesn't have to a conditional cleanup because we're going + // to pop it off in a second. + CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, + Ptr, OperatorDelete, ElementType); + + if (Dtor) + CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, + /*ForVirtualBase=*/false, Ptr); + else if (CGF.getLangOpts().ObjCAutoRefCount && + ElementType->isObjCLifetimeType()) { + switch (ElementType.getObjCLifetime()) { + case Qualifiers::OCL_None: + case Qualifiers::OCL_ExplicitNone: + case Qualifiers::OCL_Autoreleasing: + break; + + case Qualifiers::OCL_Strong: { + // Load the pointer value. + llvm::Value *PtrValue = CGF.Builder.CreateLoad(Ptr, + ElementType.isVolatileQualified()); + + CGF.EmitARCRelease(PtrValue, /*precise*/ true); + break; + } + + case Qualifiers::OCL_Weak: + CGF.EmitARCDestroyWeak(Ptr); + break; + } + } + + CGF.PopCleanupBlock(); +} + +namespace { + /// Calls the given 'operator delete' on an array of objects. + struct CallArrayDelete : EHScopeStack::Cleanup { + llvm::Value *Ptr; + const FunctionDecl *OperatorDelete; + llvm::Value *NumElements; + QualType ElementType; + CharUnits CookieSize; + + CallArrayDelete(llvm::Value *Ptr, + const FunctionDecl *OperatorDelete, + llvm::Value *NumElements, + QualType ElementType, + CharUnits CookieSize) + : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements), + ElementType(ElementType), CookieSize(CookieSize) {} + + void Emit(CodeGenFunction &CGF, Flags flags) { + const FunctionProtoType *DeleteFTy = + OperatorDelete->getType()->getAs<FunctionProtoType>(); + assert(DeleteFTy->getNumArgs() == 1 || DeleteFTy->getNumArgs() == 2); + + CallArgList Args; + + // Pass the pointer as the first argument. + QualType VoidPtrTy = DeleteFTy->getArgType(0); + llvm::Value *DeletePtr + = CGF.Builder.CreateBitCast(Ptr, CGF.ConvertType(VoidPtrTy)); + Args.add(RValue::get(DeletePtr), VoidPtrTy); + + // Pass the original requested size as the second argument. + if (DeleteFTy->getNumArgs() == 2) { + QualType size_t = DeleteFTy->getArgType(1); + llvm::IntegerType *SizeTy + = cast<llvm::IntegerType>(CGF.ConvertType(size_t)); + + CharUnits ElementTypeSize = + CGF.CGM.getContext().getTypeSizeInChars(ElementType); + + // The size of an element, multiplied by the number of elements. + llvm::Value *Size + = llvm::ConstantInt::get(SizeTy, ElementTypeSize.getQuantity()); + Size = CGF.Builder.CreateMul(Size, NumElements); + + // Plus the size of the cookie if applicable. + if (!CookieSize.isZero()) { + llvm::Value *CookieSizeV + = llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity()); + Size = CGF.Builder.CreateAdd(Size, CookieSizeV); + } + + Args.add(RValue::get(Size), size_t); + } + + // Emit the call to delete. + CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(Args, DeleteFTy), + CGF.CGM.GetAddrOfFunction(OperatorDelete), + ReturnValueSlot(), Args, OperatorDelete); + } + }; +} + +/// Emit the code for deleting an array of objects. +static void EmitArrayDelete(CodeGenFunction &CGF, + const CXXDeleteExpr *E, + llvm::Value *deletedPtr, + QualType elementType) { + llvm::Value *numElements = 0; + llvm::Value *allocatedPtr = 0; + CharUnits cookieSize; + CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType, + numElements, allocatedPtr, cookieSize); + + assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer"); + + // Make sure that we call delete even if one of the dtors throws. + const FunctionDecl *operatorDelete = E->getOperatorDelete(); + CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup, + allocatedPtr, operatorDelete, + numElements, elementType, + cookieSize); + + // Destroy the elements. + if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) { + assert(numElements && "no element count for a type with a destructor!"); + + llvm::Value *arrayEnd = + CGF.Builder.CreateInBoundsGEP(deletedPtr, numElements, "delete.end"); + + // Note that it is legal to allocate a zero-length array, and we + // can never fold the check away because the length should always + // come from a cookie. + CGF.emitArrayDestroy(deletedPtr, arrayEnd, elementType, + CGF.getDestroyer(dtorKind), + /*checkZeroLength*/ true, + CGF.needsEHCleanup(dtorKind)); + } + + // Pop the cleanup block. + CGF.PopCleanupBlock(); +} + +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() != CK_UserDefinedConversion && + ICE->getType()->isVoidPointerType()) + Arg = ICE->getSubExpr(); + else + break; + } + + 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.CreateIsNull(Ptr, "isnull"); + + Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull); + EmitBlock(DeleteNotNull); + + // We might be deleting a pointer to array. If so, GEP down to the + // first non-array element. + // (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*) + QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType(); + if (DeleteTy->isConstantArrayType()) { + llvm::Value *Zero = Builder.getInt32(0); + SmallVector<llvm::Value*,8> GEP; + + GEP.push_back(Zero); // point at the outermost array + + // For each layer of array type we're pointing at: + while (const ConstantArrayType *Arr + = getContext().getAsConstantArrayType(DeleteTy)) { + // 1. Unpeel the array type. + DeleteTy = Arr->getElementType(); + + // 2. GEP to the first element of the array. + GEP.push_back(Zero); + } + + Ptr = Builder.CreateInBoundsGEP(Ptr, GEP, "del.first"); + } + + assert(ConvertTypeForMem(DeleteTy) == + cast<llvm::PointerType>(Ptr->getType())->getElementType()); + + if (E->isArrayForm()) { + EmitArrayDelete(*this, E, Ptr, DeleteTy); + } else { + EmitObjectDelete(*this, E->getOperatorDelete(), Ptr, DeleteTy, + E->isGlobalDelete()); + } + + EmitBlock(DeleteEnd); +} + +static llvm::Constant *getBadTypeidFn(CodeGenFunction &CGF) { + // void __cxa_bad_typeid(); + llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid"); +} + +static void EmitBadTypeidCall(CodeGenFunction &CGF) { + llvm::Value *Fn = getBadTypeidFn(CGF); + CGF.EmitCallOrInvoke(Fn).setDoesNotReturn(); + CGF.Builder.CreateUnreachable(); +} + +static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, + const Expr *E, + llvm::Type *StdTypeInfoPtrTy) { + // Get the vtable pointer. + llvm::Value *ThisPtr = CGF.EmitLValue(E).getAddress(); + + // C++ [expr.typeid]p2: + // If the glvalue expression is obtained by applying the unary * operator to + // a pointer and the pointer is a null pointer value, the typeid expression + // throws the std::bad_typeid exception. + if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParens())) { + if (UO->getOpcode() == UO_Deref) { + llvm::BasicBlock *BadTypeidBlock = + CGF.createBasicBlock("typeid.bad_typeid"); + llvm::BasicBlock *EndBlock = + CGF.createBasicBlock("typeid.end"); + + llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr); + CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock); + + CGF.EmitBlock(BadTypeidBlock); + EmitBadTypeidCall(CGF); + CGF.EmitBlock(EndBlock); + } + } + + llvm::Value *Value = CGF.GetVTablePtr(ThisPtr, + StdTypeInfoPtrTy->getPointerTo()); + + // Load the type info. + Value = CGF.Builder.CreateConstInBoundsGEP1_64(Value, -1ULL); + return CGF.Builder.CreateLoad(Value); +} + +llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) { + llvm::Type *StdTypeInfoPtrTy = + ConvertType(E->getType())->getPointerTo(); + + if (E->isTypeOperand()) { + llvm::Constant *TypeInfo = + CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand()); + return Builder.CreateBitCast(TypeInfo, StdTypeInfoPtrTy); + } + + // C++ [expr.typeid]p2: + // When typeid is applied to a glvalue expression whose type is a + // polymorphic class type, the result refers to a std::type_info object + // representing the type of the most derived object (that is, the dynamic + // type) to which the glvalue refers. + if (E->getExprOperand()->isGLValue()) { + if (const RecordType *RT = + E->getExprOperand()->getType()->getAs<RecordType>()) { + const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->isPolymorphic()) + return EmitTypeidFromVTable(*this, E->getExprOperand(), + StdTypeInfoPtrTy); + } + } + + QualType OperandTy = E->getExprOperand()->getType(); + return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy), + StdTypeInfoPtrTy); +} + +static llvm::Constant *getDynamicCastFn(CodeGenFunction &CGF) { + // void *__dynamic_cast(const void *sub, + // const abi::__class_type_info *src, + // const abi::__class_type_info *dst, + // std::ptrdiff_t src2dst_offset); + + llvm::Type *Int8PtrTy = CGF.Int8PtrTy; + llvm::Type *PtrDiffTy = + CGF.ConvertType(CGF.getContext().getPointerDiffType()); + + llvm::Type *Args[4] = { Int8PtrTy, Int8PtrTy, Int8PtrTy, PtrDiffTy }; + + llvm::FunctionType *FTy = + llvm::FunctionType::get(Int8PtrTy, Args, false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__dynamic_cast"); +} + +static llvm::Constant *getBadCastFn(CodeGenFunction &CGF) { + // void __cxa_bad_cast(); + llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false); + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_cast"); +} + +static void EmitBadCastCall(CodeGenFunction &CGF) { + llvm::Value *Fn = getBadCastFn(CGF); + CGF.EmitCallOrInvoke(Fn).setDoesNotReturn(); + CGF.Builder.CreateUnreachable(); +} + +static llvm::Value * +EmitDynamicCastCall(CodeGenFunction &CGF, llvm::Value *Value, + QualType SrcTy, QualType DestTy, + llvm::BasicBlock *CastEnd) { + llvm::Type *PtrDiffLTy = + CGF.ConvertType(CGF.getContext().getPointerDiffType()); + llvm::Type *DestLTy = CGF.ConvertType(DestTy); + + if (const PointerType *PTy = DestTy->getAs<PointerType>()) { + if (PTy->getPointeeType()->isVoidType()) { + // C++ [expr.dynamic.cast]p7: + // If T is "pointer to cv void," then the result is a pointer to the + // most derived object pointed to by v. + + // Get the vtable pointer. + llvm::Value *VTable = CGF.GetVTablePtr(Value, PtrDiffLTy->getPointerTo()); + + // Get the offset-to-top from the vtable. + llvm::Value *OffsetToTop = + CGF.Builder.CreateConstInBoundsGEP1_64(VTable, -2ULL); + OffsetToTop = CGF.Builder.CreateLoad(OffsetToTop, "offset.to.top"); + + // Finally, add the offset to the pointer. + Value = CGF.EmitCastToVoidPtr(Value); + Value = CGF.Builder.CreateInBoundsGEP(Value, OffsetToTop); + + return CGF.Builder.CreateBitCast(Value, DestLTy); + } + } + + QualType SrcRecordTy; + QualType DestRecordTy; + + if (const PointerType *DestPTy = DestTy->getAs<PointerType>()) { + SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType(); + DestRecordTy = DestPTy->getPointeeType(); + } else { + SrcRecordTy = SrcTy; + DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType(); + } + + assert(SrcRecordTy->isRecordType() && "source type must be a record type!"); + assert(DestRecordTy->isRecordType() && "dest type must be a record type!"); + + llvm::Value *SrcRTTI = + CGF.CGM.GetAddrOfRTTIDescriptor(SrcRecordTy.getUnqualifiedType()); + llvm::Value *DestRTTI = + CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType()); + + // FIXME: Actually compute a hint here. + llvm::Value *OffsetHint = llvm::ConstantInt::get(PtrDiffLTy, -1ULL); + + // Emit the call to __dynamic_cast. + Value = CGF.EmitCastToVoidPtr(Value); + Value = CGF.Builder.CreateCall4(getDynamicCastFn(CGF), Value, + SrcRTTI, DestRTTI, OffsetHint); + Value = CGF.Builder.CreateBitCast(Value, DestLTy); + + /// C++ [expr.dynamic.cast]p9: + /// A failed cast to reference type throws std::bad_cast + if (DestTy->isReferenceType()) { + llvm::BasicBlock *BadCastBlock = + CGF.createBasicBlock("dynamic_cast.bad_cast"); + + llvm::Value *IsNull = CGF.Builder.CreateIsNull(Value); + CGF.Builder.CreateCondBr(IsNull, BadCastBlock, CastEnd); + + CGF.EmitBlock(BadCastBlock); + EmitBadCastCall(CGF); + } + + return Value; +} + +static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF, + QualType DestTy) { + llvm::Type *DestLTy = CGF.ConvertType(DestTy); + if (DestTy->isPointerType()) + return llvm::Constant::getNullValue(DestLTy); + + /// C++ [expr.dynamic.cast]p9: + /// A failed cast to reference type throws std::bad_cast + EmitBadCastCall(CGF); + + CGF.EmitBlock(CGF.createBasicBlock("dynamic_cast.end")); + return llvm::UndefValue::get(DestLTy); +} + +llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *Value, + const CXXDynamicCastExpr *DCE) { + QualType DestTy = DCE->getTypeAsWritten(); + + if (DCE->isAlwaysNull()) + return EmitDynamicCastToNull(*this, DestTy); + + QualType SrcTy = DCE->getSubExpr()->getType(); + + // C++ [expr.dynamic.cast]p4: + // If the value of v is a null pointer value in the pointer case, the result + // is the null pointer value of type T. + bool ShouldNullCheckSrcValue = SrcTy->isPointerType(); + + llvm::BasicBlock *CastNull = 0; + llvm::BasicBlock *CastNotNull = 0; + llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end"); + + if (ShouldNullCheckSrcValue) { + CastNull = createBasicBlock("dynamic_cast.null"); + CastNotNull = createBasicBlock("dynamic_cast.notnull"); + + llvm::Value *IsNull = Builder.CreateIsNull(Value); + Builder.CreateCondBr(IsNull, CastNull, CastNotNull); + EmitBlock(CastNotNull); + } + + Value = EmitDynamicCastCall(*this, Value, SrcTy, DestTy, CastEnd); + + if (ShouldNullCheckSrcValue) { + EmitBranch(CastEnd); + + EmitBlock(CastNull); + EmitBranch(CastEnd); + } + + EmitBlock(CastEnd); + + if (ShouldNullCheckSrcValue) { + llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2); + PHI->addIncoming(Value, CastNotNull); + PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull); + + Value = PHI; + } + + return Value; +} + +void CodeGenFunction::EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Slot) { + RunCleanupsScope Scope(*this); + LValue SlotLV = MakeAddrLValue(Slot.getAddr(), E->getType(), + Slot.getAlignment()); + + CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin(); + for (LambdaExpr::capture_init_iterator i = E->capture_init_begin(), + e = E->capture_init_end(); + i != e; ++i, ++CurField) { + // Emit initialization + + LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField); + ArrayRef<VarDecl *> ArrayIndexes; + if (CurField->getType()->isArrayType()) + ArrayIndexes = E->getCaptureInitIndexVars(i); + EmitInitializerForField(*CurField, LV, *i, ArrayIndexes); + } +} |