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Diffstat (limited to 'clang/lib/CodeGen/CGExprCXX.cpp')
| -rw-r--r-- | clang/lib/CodeGen/CGExprCXX.cpp | 2271 |
1 files changed, 2271 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp new file mode 100644 index 000000000000..114d806d454b --- /dev/null +++ b/clang/lib/CodeGen/CGExprCXX.cpp @@ -0,0 +1,2271 @@ +//===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This contains code dealing with code generation of C++ expressions +// +//===----------------------------------------------------------------------===// + +#include "CGCUDARuntime.h" +#include "CGCXXABI.h" +#include "CGDebugInfo.h" +#include "CGObjCRuntime.h" +#include "CodeGenFunction.h" +#include "ConstantEmitter.h" +#include "TargetInfo.h" +#include "clang/Basic/CodeGenOptions.h" +#include "clang/CodeGen/CGFunctionInfo.h" +#include "llvm/IR/Intrinsics.h" + +using namespace clang; +using namespace CodeGen; + +namespace { +struct MemberCallInfo { + RequiredArgs ReqArgs; + // Number of prefix arguments for the call. Ignores the `this` pointer. + unsigned PrefixSize; +}; +} + +static MemberCallInfo +commonEmitCXXMemberOrOperatorCall(CodeGenFunction &CGF, const CXXMethodDecl *MD, + llvm::Value *This, llvm::Value *ImplicitParam, + QualType ImplicitParamTy, const CallExpr *CE, + CallArgList &Args, CallArgList *RtlArgs) { + assert(CE == nullptr || isa<CXXMemberCallExpr>(CE) || + isa<CXXOperatorCallExpr>(CE)); + assert(MD->isInstance() && + "Trying to emit a member or operator call expr on a static method!"); + + // Push the this ptr. + const CXXRecordDecl *RD = + CGF.CGM.getCXXABI().getThisArgumentTypeForMethod(MD); + Args.add(RValue::get(This), CGF.getTypes().DeriveThisType(RD, MD)); + + // If there is an implicit parameter (e.g. VTT), emit it. + if (ImplicitParam) { + Args.add(RValue::get(ImplicitParam), ImplicitParamTy); + } + + const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); + RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size()); + unsigned PrefixSize = Args.size() - 1; + + // And the rest of the call args. + if (RtlArgs) { + // Special case: if the caller emitted the arguments right-to-left already + // (prior to emitting the *this argument), we're done. This happens for + // assignment operators. + Args.addFrom(*RtlArgs); + } else if (CE) { + // Special case: skip first argument of CXXOperatorCall (it is "this"). + unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0; + CGF.EmitCallArgs(Args, FPT, drop_begin(CE->arguments(), ArgsToSkip), + CE->getDirectCallee()); + } else { + assert( + FPT->getNumParams() == 0 && + "No CallExpr specified for function with non-zero number of arguments"); + } + return {required, PrefixSize}; +} + +RValue CodeGenFunction::EmitCXXMemberOrOperatorCall( + const CXXMethodDecl *MD, const CGCallee &Callee, + ReturnValueSlot ReturnValue, + llvm::Value *This, llvm::Value *ImplicitParam, QualType ImplicitParamTy, + const CallExpr *CE, CallArgList *RtlArgs) { + const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); + CallArgList Args; + MemberCallInfo CallInfo = commonEmitCXXMemberOrOperatorCall( + *this, MD, This, ImplicitParam, ImplicitParamTy, CE, Args, RtlArgs); + auto &FnInfo = CGM.getTypes().arrangeCXXMethodCall( + Args, FPT, CallInfo.ReqArgs, CallInfo.PrefixSize); + return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr, + CE ? CE->getExprLoc() : SourceLocation()); +} + +RValue CodeGenFunction::EmitCXXDestructorCall( + GlobalDecl Dtor, const CGCallee &Callee, llvm::Value *This, QualType ThisTy, + llvm::Value *ImplicitParam, QualType ImplicitParamTy, const CallExpr *CE) { + const CXXMethodDecl *DtorDecl = cast<CXXMethodDecl>(Dtor.getDecl()); + + assert(!ThisTy.isNull()); + assert(ThisTy->getAsCXXRecordDecl() == DtorDecl->getParent() && + "Pointer/Object mixup"); + + LangAS SrcAS = ThisTy.getAddressSpace(); + LangAS DstAS = DtorDecl->getMethodQualifiers().getAddressSpace(); + if (SrcAS != DstAS) { + QualType DstTy = DtorDecl->getThisType(); + llvm::Type *NewType = CGM.getTypes().ConvertType(DstTy); + This = getTargetHooks().performAddrSpaceCast(*this, This, SrcAS, DstAS, + NewType); + } + + CallArgList Args; + commonEmitCXXMemberOrOperatorCall(*this, DtorDecl, This, ImplicitParam, + ImplicitParamTy, CE, Args, nullptr); + return EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(Dtor), Callee, + ReturnValueSlot(), Args); +} + +RValue CodeGenFunction::EmitCXXPseudoDestructorExpr( + const CXXPseudoDestructorExpr *E) { + QualType DestroyedType = E->getDestroyedType(); + if (DestroyedType.hasStrongOrWeakObjCLifetime()) { + // Automatic Reference Counting: + // If the pseudo-expression names a retainable object with weak or + // strong lifetime, the object shall be released. + Expr *BaseExpr = E->getBase(); + Address BaseValue = Address::invalid(); + Qualifiers BaseQuals; + + // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. + if (E->isArrow()) { + BaseValue = EmitPointerWithAlignment(BaseExpr); + const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>(); + BaseQuals = PTy->getPointeeType().getQualifiers(); + } else { + LValue BaseLV = EmitLValue(BaseExpr); + BaseValue = BaseLV.getAddress(); + QualType BaseTy = BaseExpr->getType(); + BaseQuals = BaseTy.getQualifiers(); + } + + switch (DestroyedType.getObjCLifetime()) { + case Qualifiers::OCL_None: + case Qualifiers::OCL_ExplicitNone: + case Qualifiers::OCL_Autoreleasing: + break; + + case Qualifiers::OCL_Strong: + EmitARCRelease(Builder.CreateLoad(BaseValue, + DestroyedType.isVolatileQualified()), + ARCPreciseLifetime); + 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. + EmitIgnoredExpr(E->getBase()); + } + + return RValue::get(nullptr); +} + +static CXXRecordDecl *getCXXRecord(const Expr *E) { + QualType T = E->getType(); + if (const PointerType *PTy = T->getAs<PointerType>()) + T = PTy->getPointeeType(); + const RecordType *Ty = T->castAs<RecordType>(); + return cast<CXXRecordDecl>(Ty->getDecl()); +} + +// 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()); + + if (MD->isStatic()) { + // The method is static, emit it as we would a regular call. + CGCallee callee = + CGCallee::forDirect(CGM.GetAddrOfFunction(MD), GlobalDecl(MD)); + return EmitCall(getContext().getPointerType(MD->getType()), callee, CE, + ReturnValue); + } + + bool HasQualifier = ME->hasQualifier(); + NestedNameSpecifier *Qualifier = HasQualifier ? ME->getQualifier() : nullptr; + bool IsArrow = ME->isArrow(); + const Expr *Base = ME->getBase(); + + return EmitCXXMemberOrOperatorMemberCallExpr( + CE, MD, ReturnValue, HasQualifier, Qualifier, IsArrow, Base); +} + +RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr( + const CallExpr *CE, const CXXMethodDecl *MD, ReturnValueSlot ReturnValue, + bool HasQualifier, NestedNameSpecifier *Qualifier, bool IsArrow, + const Expr *Base) { + assert(isa<CXXMemberCallExpr>(CE) || isa<CXXOperatorCallExpr>(CE)); + + // Compute the object pointer. + bool CanUseVirtualCall = MD->isVirtual() && !HasQualifier; + + const CXXMethodDecl *DevirtualizedMethod = nullptr; + if (CanUseVirtualCall && + MD->getDevirtualizedMethod(Base, getLangOpts().AppleKext)) { + const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType(); + DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl); + assert(DevirtualizedMethod); + const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent(); + const Expr *Inner = Base->ignoreParenBaseCasts(); + if (DevirtualizedMethod->getReturnType().getCanonicalType() != + MD->getReturnType().getCanonicalType()) + // If the return types are not the same, this might be a case where more + // code needs to run to compensate for it. For example, the derived + // method might return a type that inherits form from the return + // type of MD and has a prefix. + // For now we just avoid devirtualizing these covariant cases. + DevirtualizedMethod = nullptr; + else if (getCXXRecord(Inner) == DevirtualizedClass) + // If the class of the Inner expression is where the dynamic method + // is defined, build the this pointer from it. + Base = Inner; + else if (getCXXRecord(Base) != DevirtualizedClass) { + // If the method is defined in a class that is not the best dynamic + // one or the one of the full expression, we would have to build + // a derived-to-base cast to compute the correct this pointer, but + // we don't have support for that yet, so do a virtual call. + DevirtualizedMethod = nullptr; + } + } + + // C++17 demands that we evaluate the RHS of a (possibly-compound) assignment + // operator before the LHS. + CallArgList RtlArgStorage; + CallArgList *RtlArgs = nullptr; + if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(CE)) { + if (OCE->isAssignmentOp()) { + RtlArgs = &RtlArgStorage; + EmitCallArgs(*RtlArgs, MD->getType()->castAs<FunctionProtoType>(), + drop_begin(CE->arguments(), 1), CE->getDirectCallee(), + /*ParamsToSkip*/0, EvaluationOrder::ForceRightToLeft); + } + } + + LValue This; + if (IsArrow) { + LValueBaseInfo BaseInfo; + TBAAAccessInfo TBAAInfo; + Address ThisValue = EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo); + This = MakeAddrLValue(ThisValue, Base->getType(), BaseInfo, TBAAInfo); + } else { + This = EmitLValue(Base); + } + + if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) { + // This is the MSVC p->Ctor::Ctor(...) extension. We assume that's + // constructing a new complete object of type Ctor. + assert(!RtlArgs); + assert(ReturnValue.isNull() && "Constructor shouldn't have return value"); + CallArgList Args; + commonEmitCXXMemberOrOperatorCall( + *this, Ctor, This.getPointer(), /*ImplicitParam=*/nullptr, + /*ImplicitParamTy=*/QualType(), CE, Args, nullptr); + + EmitCXXConstructorCall(Ctor, Ctor_Complete, /*ForVirtualBase=*/false, + /*Delegating=*/false, This.getAddress(), Args, + AggValueSlot::DoesNotOverlap, CE->getExprLoc(), + /*NewPointerIsChecked=*/false); + return RValue::get(nullptr); + } + + if (MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion())) { + if (isa<CXXDestructorDecl>(MD)) return RValue::get(nullptr); + if (!MD->getParent()->mayInsertExtraPadding()) { + 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. + LValue RHS = isa<CXXOperatorCallExpr>(CE) + ? MakeNaturalAlignAddrLValue( + (*RtlArgs)[0].getRValue(*this).getScalarVal(), + (*(CE->arg_begin() + 1))->getType()) + : EmitLValue(*CE->arg_begin()); + EmitAggregateAssign(This, RHS, CE->getType()); + return RValue::get(This.getPointer()); + } + llvm_unreachable("unknown trivial member function"); + } + } + + // Compute the function type we're calling. + const CXXMethodDecl *CalleeDecl = + DevirtualizedMethod ? DevirtualizedMethod : MD; + const CGFunctionInfo *FInfo = nullptr; + if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl)) + FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration( + GlobalDecl(Dtor, Dtor_Complete)); + else + FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl); + + llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo); + + // C++11 [class.mfct.non-static]p2: + // If a non-static member function of a class X is called for an object that + // is not of type X, or of a type derived from X, the behavior is undefined. + SourceLocation CallLoc; + ASTContext &C = getContext(); + if (CE) + CallLoc = CE->getExprLoc(); + + SanitizerSet SkippedChecks; + if (const auto *CMCE = dyn_cast<CXXMemberCallExpr>(CE)) { + auto *IOA = CMCE->getImplicitObjectArgument(); + bool IsImplicitObjectCXXThis = IsWrappedCXXThis(IOA); + if (IsImplicitObjectCXXThis) + SkippedChecks.set(SanitizerKind::Alignment, true); + if (IsImplicitObjectCXXThis || isa<DeclRefExpr>(IOA)) + SkippedChecks.set(SanitizerKind::Null, true); + } + EmitTypeCheck(CodeGenFunction::TCK_MemberCall, CallLoc, This.getPointer(), + C.getRecordType(CalleeDecl->getParent()), + /*Alignment=*/CharUnits::Zero(), SkippedChecks); + + // 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 = CanUseVirtualCall && !DevirtualizedMethod; + + if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl)) { + assert(CE->arg_begin() == CE->arg_end() && + "Destructor shouldn't have explicit parameters"); + assert(ReturnValue.isNull() && "Destructor shouldn't have return value"); + if (UseVirtualCall) { + CGM.getCXXABI().EmitVirtualDestructorCall( + *this, Dtor, Dtor_Complete, This.getAddress(), + cast<CXXMemberCallExpr>(CE)); + } else { + GlobalDecl GD(Dtor, Dtor_Complete); + CGCallee Callee; + if (getLangOpts().AppleKext && Dtor->isVirtual() && HasQualifier) + Callee = BuildAppleKextVirtualCall(Dtor, Qualifier, Ty); + else if (!DevirtualizedMethod) + Callee = + CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD, FInfo, Ty), GD); + else { + Callee = CGCallee::forDirect(CGM.GetAddrOfFunction(GD, Ty), GD); + } + + QualType ThisTy = + IsArrow ? Base->getType()->getPointeeType() : Base->getType(); + EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy, + /*ImplicitParam=*/nullptr, + /*ImplicitParamTy=*/QualType(), nullptr); + } + return RValue::get(nullptr); + } + + // FIXME: Uses of 'MD' past this point need to be audited. We may need to use + // 'CalleeDecl' instead. + + CGCallee Callee; + if (UseVirtualCall) { + Callee = CGCallee::forVirtual(CE, MD, This.getAddress(), Ty); + } else { + if (SanOpts.has(SanitizerKind::CFINVCall) && + MD->getParent()->isDynamicClass()) { + llvm::Value *VTable; + const CXXRecordDecl *RD; + std::tie(VTable, RD) = + CGM.getCXXABI().LoadVTablePtr(*this, This.getAddress(), + CalleeDecl->getParent()); + EmitVTablePtrCheckForCall(RD, VTable, CFITCK_NVCall, CE->getBeginLoc()); + } + + if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier) + Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty); + else if (!DevirtualizedMethod) + Callee = + CGCallee::forDirect(CGM.GetAddrOfFunction(MD, Ty), GlobalDecl(MD)); + else { + Callee = + CGCallee::forDirect(CGM.GetAddrOfFunction(DevirtualizedMethod, Ty), + GlobalDecl(DevirtualizedMethod)); + } + } + + if (MD->isVirtual()) { + Address NewThisAddr = + CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall( + *this, CalleeDecl, This.getAddress(), UseVirtualCall); + This.setAddress(NewThisAddr); + } + + return EmitCXXMemberOrOperatorCall( + CalleeDecl, Callee, ReturnValue, This.getPointer(), + /*ImplicitParam=*/nullptr, QualType(), CE, RtlArgs); +} + +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 auto *MPT = MemFnExpr->getType()->castAs<MemberPointerType>(); + const auto *FPT = MPT->getPointeeType()->castAs<FunctionProtoType>(); + const auto *RD = + cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl()); + + // Emit the 'this' pointer. + Address This = Address::invalid(); + if (BO->getOpcode() == BO_PtrMemI) + This = EmitPointerWithAlignment(BaseExpr); + else + This = EmitLValue(BaseExpr).getAddress(); + + EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This.getPointer(), + QualType(MPT->getClass(), 0)); + + // Get the member function pointer. + llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr); + + // Ask the ABI to load the callee. Note that This is modified. + llvm::Value *ThisPtrForCall = nullptr; + CGCallee Callee = + CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This, + ThisPtrForCall, MemFnPtr, MPT); + + CallArgList Args; + + QualType ThisType = + getContext().getPointerType(getContext().getTagDeclType(RD)); + + // Push the this ptr. + Args.add(RValue::get(ThisPtrForCall), ThisType); + + RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1); + + // And the rest of the call args + EmitCallArgs(Args, FPT, E->arguments()); + return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required, + /*PrefixSize=*/0), + Callee, ReturnValue, Args, nullptr, E->getExprLoc()); +} + +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!"); + return EmitCXXMemberOrOperatorMemberCallExpr( + E, MD, ReturnValue, /*HasQualifier=*/false, /*Qualifier=*/nullptr, + /*IsArrow=*/false, E->getArg(0)); +} + +RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E, + ReturnValueSlot ReturnValue) { + return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue); +} + +static void EmitNullBaseClassInitialization(CodeGenFunction &CGF, + Address DestPtr, + const CXXRecordDecl *Base) { + if (Base->isEmpty()) + return; + + DestPtr = CGF.Builder.CreateElementBitCast(DestPtr, CGF.Int8Ty); + + const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base); + CharUnits NVSize = Layout.getNonVirtualSize(); + + // We cannot simply zero-initialize the entire base sub-object if vbptrs are + // present, they are initialized by the most derived class before calling the + // constructor. + SmallVector<std::pair<CharUnits, CharUnits>, 1> Stores; + Stores.emplace_back(CharUnits::Zero(), NVSize); + + // Each store is split by the existence of a vbptr. + CharUnits VBPtrWidth = CGF.getPointerSize(); + std::vector<CharUnits> VBPtrOffsets = + CGF.CGM.getCXXABI().getVBPtrOffsets(Base); + for (CharUnits VBPtrOffset : VBPtrOffsets) { + // Stop before we hit any virtual base pointers located in virtual bases. + if (VBPtrOffset >= NVSize) + break; + std::pair<CharUnits, CharUnits> LastStore = Stores.pop_back_val(); + CharUnits LastStoreOffset = LastStore.first; + CharUnits LastStoreSize = LastStore.second; + + CharUnits SplitBeforeOffset = LastStoreOffset; + CharUnits SplitBeforeSize = VBPtrOffset - SplitBeforeOffset; + assert(!SplitBeforeSize.isNegative() && "negative store size!"); + if (!SplitBeforeSize.isZero()) + Stores.emplace_back(SplitBeforeOffset, SplitBeforeSize); + + CharUnits SplitAfterOffset = VBPtrOffset + VBPtrWidth; + CharUnits SplitAfterSize = LastStoreSize - SplitAfterOffset; + assert(!SplitAfterSize.isNegative() && "negative store size!"); + if (!SplitAfterSize.isZero()) + Stores.emplace_back(SplitAfterOffset, SplitAfterSize); + } + + // 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. + llvm::Constant *NullConstantForBase = CGF.CGM.EmitNullConstantForBase(Base); + if (!NullConstantForBase->isNullValue()) { + llvm::GlobalVariable *NullVariable = new llvm::GlobalVariable( + CGF.CGM.getModule(), NullConstantForBase->getType(), + /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, + NullConstantForBase, Twine()); + + CharUnits Align = std::max(Layout.getNonVirtualAlignment(), + DestPtr.getAlignment()); + NullVariable->setAlignment(Align.getAsAlign()); + + Address SrcPtr = Address(CGF.EmitCastToVoidPtr(NullVariable), Align); + + // Get and call the appropriate llvm.memcpy overload. + for (std::pair<CharUnits, CharUnits> Store : Stores) { + CharUnits StoreOffset = Store.first; + CharUnits StoreSize = Store.second; + llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize); + CGF.Builder.CreateMemCpy( + CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset), + CGF.Builder.CreateConstInBoundsByteGEP(SrcPtr, StoreOffset), + StoreSizeVal); + } + + // 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. + } else { + for (std::pair<CharUnits, CharUnits> Store : Stores) { + CharUnits StoreOffset = Store.first; + CharUnits StoreSize = Store.second; + llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize); + CGF.Builder.CreateMemSet( + CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset), + CGF.Builder.getInt8(0), StoreSizeVal); + } + } +} + +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: + case CXXConstructExpr::CK_Complete: + EmitNullInitialization(Dest.getAddress(), E->getType()); + break; + case CXXConstructExpr::CK_VirtualBase: + case CXXConstructExpr::CK_NonVirtualBase: + EmitNullBaseClassInitialization(*this, Dest.getAddress(), + 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 (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 ArrayType *arrayType + = getContext().getAsArrayType(E->getType())) { + EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddress(), E, + Dest.isSanitizerChecked()); + } else { + CXXCtorType Type = Ctor_Complete; + bool ForVirtualBase = false; + bool Delegating = false; + + switch (E->getConstructionKind()) { + case CXXConstructExpr::CK_Delegating: + // We should be emitting a constructor; GlobalDecl will assert this + Type = CurGD.getCtorType(); + Delegating = true; + break; + + case CXXConstructExpr::CK_Complete: + Type = Ctor_Complete; + break; + + case CXXConstructExpr::CK_VirtualBase: + ForVirtualBase = true; + LLVM_FALLTHROUGH; + + case CXXConstructExpr::CK_NonVirtualBase: + Type = Ctor_Base; + } + + // Call the constructor. + EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating, Dest, E); + } +} + +void CodeGenFunction::EmitSynthesizedCXXCopyCtor(Address Dest, Address 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); +} + +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 = + ConstantEmitter(CGF).tryEmitAbstract(*e->getArraySize(), e->getType()); + if (!numElements) + 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 = nullptr; + + // 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::Function *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.CreateCall(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::Function *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.CreateCall(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, Address NewPtr, + AggValueSlot::Overlap_t MayOverlap) { + // FIXME: Refactor with EmitExprAsInit. + switch (CGF.getEvaluationKind(AllocType)) { + case TEK_Scalar: + CGF.EmitScalarInit(Init, nullptr, + CGF.MakeAddrLValue(NewPtr, AllocType), false); + return; + case TEK_Complex: + CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType), + /*isInit*/ true); + return; + case TEK_Aggregate: { + AggValueSlot Slot + = AggValueSlot::forAddr(NewPtr, AllocType.getQualifiers(), + AggValueSlot::IsDestructed, + AggValueSlot::DoesNotNeedGCBarriers, + AggValueSlot::IsNotAliased, + MayOverlap, AggValueSlot::IsNotZeroed, + AggValueSlot::IsSanitizerChecked); + CGF.EmitAggExpr(Init, Slot); + return; + } + } + llvm_unreachable("bad evaluation kind"); +} + +void CodeGenFunction::EmitNewArrayInitializer( + const CXXNewExpr *E, QualType ElementType, llvm::Type *ElementTy, + Address BeginPtr, llvm::Value *NumElements, + llvm::Value *AllocSizeWithoutCookie) { + // If we have a type with trivial initialization and no initializer, + // there's nothing to do. + if (!E->hasInitializer()) + return; + + Address CurPtr = BeginPtr; + + unsigned InitListElements = 0; + + const Expr *Init = E->getInitializer(); + Address EndOfInit = Address::invalid(); + QualType::DestructionKind DtorKind = ElementType.isDestructedType(); + EHScopeStack::stable_iterator Cleanup; + llvm::Instruction *CleanupDominator = nullptr; + + CharUnits ElementSize = getContext().getTypeSizeInChars(ElementType); + CharUnits ElementAlign = + BeginPtr.getAlignment().alignmentOfArrayElement(ElementSize); + + // Attempt to perform zero-initialization using memset. + auto TryMemsetInitialization = [&]() -> bool { + // FIXME: If the type is a pointer-to-data-member under the Itanium ABI, + // we can initialize with a memset to -1. + if (!CGM.getTypes().isZeroInitializable(ElementType)) + return false; + + // Optimization: since zero initialization will just set the memory + // to all zeroes, generate a single memset to do it in one shot. + + // Subtract out the size of any elements we've already initialized. + auto *RemainingSize = AllocSizeWithoutCookie; + if (InitListElements) { + // We know this can't overflow; we check this when doing the allocation. + auto *InitializedSize = llvm::ConstantInt::get( + RemainingSize->getType(), + getContext().getTypeSizeInChars(ElementType).getQuantity() * + InitListElements); + RemainingSize = Builder.CreateSub(RemainingSize, InitializedSize); + } + + // Create the memset. + Builder.CreateMemSet(CurPtr, Builder.getInt8(0), RemainingSize, false); + return true; + }; + + // If the initializer is an initializer list, first do the explicit elements. + if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { + // Initializing from a (braced) string literal is a special case; the init + // list element does not initialize a (single) array element. + if (ILE->isStringLiteralInit()) { + // Initialize the initial portion of length equal to that of the string + // literal. The allocation must be for at least this much; we emitted a + // check for that earlier. + AggValueSlot Slot = + AggValueSlot::forAddr(CurPtr, ElementType.getQualifiers(), + AggValueSlot::IsDestructed, + AggValueSlot::DoesNotNeedGCBarriers, + AggValueSlot::IsNotAliased, + AggValueSlot::DoesNotOverlap, + AggValueSlot::IsNotZeroed, + AggValueSlot::IsSanitizerChecked); + EmitAggExpr(ILE->getInit(0), Slot); + + // Move past these elements. + InitListElements = + cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe()) + ->getSize().getZExtValue(); + CurPtr = + Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(), + Builder.getSize(InitListElements), + "string.init.end"), + CurPtr.getAlignment().alignmentAtOffset(InitListElements * + ElementSize)); + + // Zero out the rest, if any remain. + llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements); + if (!ConstNum || !ConstNum->equalsInt(InitListElements)) { + bool OK = TryMemsetInitialization(); + (void)OK; + assert(OK && "couldn't memset character type?"); + } + return; + } + + InitListElements = ILE->getNumInits(); + + // If this is a multi-dimensional array new, we will initialize multiple + // elements with each init list element. + QualType AllocType = E->getAllocatedType(); + if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>( + AllocType->getAsArrayTypeUnsafe())) { + ElementTy = ConvertTypeForMem(AllocType); + CurPtr = Builder.CreateElementBitCast(CurPtr, ElementTy); + InitListElements *= getContext().getConstantArrayElementCount(CAT); + } + + // 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(), getPointerAlign(), + "array.init.end"); + CleanupDominator = Builder.CreateStore(BeginPtr.getPointer(), EndOfInit); + pushIrregularPartialArrayCleanup(BeginPtr.getPointer(), EndOfInit, + ElementType, ElementAlign, + getDestroyer(DtorKind)); + Cleanup = EHStack.stable_begin(); + } + + CharUnits StartAlign = CurPtr.getAlignment(); + 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.isValid()) { + auto FinishedPtr = + Builder.CreateBitCast(CurPtr.getPointer(), BeginPtr.getType()); + Builder.CreateStore(FinishedPtr, EndOfInit); + } + // FIXME: If the last initializer is an incomplete initializer list for + // an array, and we have an array filler, we can fold together the two + // initialization loops. + StoreAnyExprIntoOneUnit(*this, ILE->getInit(i), + ILE->getInit(i)->getType(), CurPtr, + AggValueSlot::DoesNotOverlap); + CurPtr = Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(), + Builder.getSize(1), + "array.exp.next"), + StartAlign.alignmentAtOffset((i + 1) * ElementSize)); + } + + // The remaining elements are filled with the array filler expression. + Init = ILE->getArrayFiller(); + + // Extract the initializer for the individual array elements by pulling + // out the array filler from all the nested initializer lists. This avoids + // generating a nested loop for the initialization. + while (Init && Init->getType()->isConstantArrayType()) { + auto *SubILE = dyn_cast<InitListExpr>(Init); + if (!SubILE) + break; + assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?"); + Init = SubILE->getArrayFiller(); + } + + // Switch back to initializing one base element at a time. + CurPtr = Builder.CreateBitCast(CurPtr, BeginPtr.getType()); + } + + // If all elements have already been initialized, skip any further + // initialization. + llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements); + if (ConstNum && ConstNum->getZExtValue() <= InitListElements) { + // If there was a Cleanup, deactivate it. + if (CleanupDominator) + DeactivateCleanupBlock(Cleanup, CleanupDominator); + return; + } + + assert(Init && "have trailing elements to initialize but no initializer"); + + // If this is a constructor call, try to optimize it out, and failing that + // emit a single loop to initialize all remaining elements. + if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) { + CXXConstructorDecl *Ctor = CCE->getConstructor(); + if (Ctor->isTrivial()) { + // If new expression did not specify value-initialization, then there + // is no initialization. + if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty()) + return; + + if (TryMemsetInitialization()) + return; + } + + // Store the new Cleanup position for irregular Cleanups. + // + // FIXME: Share this cleanup with the constructor call emission rather than + // having it create a cleanup of its own. + if (EndOfInit.isValid()) + Builder.CreateStore(CurPtr.getPointer(), EndOfInit); + + // Emit a constructor call loop to initialize the remaining elements. + if (InitListElements) + NumElements = Builder.CreateSub( + NumElements, + llvm::ConstantInt::get(NumElements->getType(), InitListElements)); + EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, CCE, + /*NewPointerIsChecked*/true, + CCE->requiresZeroInitialization()); + return; + } + + // If this is value-initialization, we can usually use memset. + ImplicitValueInitExpr IVIE(ElementType); + if (isa<ImplicitValueInitExpr>(Init)) { + if (TryMemsetInitialization()) + return; + + // Switch to an ImplicitValueInitExpr for the element type. This handles + // only one case: multidimensional array new of pointers to members. In + // all other cases, we already have an initializer for the array element. + Init = &IVIE; + } + + // At this point we should have found an initializer for the individual + // elements of the array. + assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) && + "got wrong type of element to initialize"); + + // If we have an empty initializer list, we can usually use memset. + if (auto *ILE = dyn_cast<InitListExpr>(Init)) + if (ILE->getNumInits() == 0 && TryMemsetInitialization()) + return; + + // If we have a struct whose every field is value-initialized, we can + // usually use memset. + if (auto *ILE = dyn_cast<InitListExpr>(Init)) { + if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { + if (RType->getDecl()->isStruct()) { + unsigned NumElements = 0; + if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RType->getDecl())) + NumElements = CXXRD->getNumBases(); + for (auto *Field : RType->getDecl()->fields()) + if (!Field->isUnnamedBitfield()) + ++NumElements; + // FIXME: Recurse into nested InitListExprs. + if (ILE->getNumInits() == NumElements) + for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) + if (!isa<ImplicitValueInitExpr>(ILE->getInit(i))) + --NumElements; + if (ILE->getNumInits() == NumElements && TryMemsetInitialization()) + return; + } + } + } + + // Create the loop blocks. + llvm::BasicBlock *EntryBB = Builder.GetInsertBlock(); + llvm::BasicBlock *LoopBB = createBasicBlock("new.loop"); + llvm::BasicBlock *ContBB = createBasicBlock("new.loop.end"); + + // Find the end of the array, hoisted out of the loop. + llvm::Value *EndPtr = + Builder.CreateInBoundsGEP(BeginPtr.getPointer(), NumElements, "array.end"); + + // If the number of elements isn't constant, we have to now check if there is + // anything left to initialize. + if (!ConstNum) { + llvm::Value *IsEmpty = + Builder.CreateICmpEQ(CurPtr.getPointer(), EndPtr, "array.isempty"); + Builder.CreateCondBr(IsEmpty, ContBB, LoopBB); + } + + // Enter the loop. + EmitBlock(LoopBB); + + // Set up the current-element phi. + llvm::PHINode *CurPtrPhi = + Builder.CreatePHI(CurPtr.getType(), 2, "array.cur"); + CurPtrPhi->addIncoming(CurPtr.getPointer(), EntryBB); + + CurPtr = Address(CurPtrPhi, ElementAlign); + + // Store the new Cleanup position for irregular Cleanups. + if (EndOfInit.isValid()) + Builder.CreateStore(CurPtr.getPointer(), EndOfInit); + + // Enter a partial-destruction Cleanup if necessary. + if (!CleanupDominator && needsEHCleanup(DtorKind)) { + pushRegularPartialArrayCleanup(BeginPtr.getPointer(), CurPtr.getPointer(), + ElementType, ElementAlign, + getDestroyer(DtorKind)); + Cleanup = EHStack.stable_begin(); + CleanupDominator = Builder.CreateUnreachable(); + } + + // Emit the initializer into this element. + StoreAnyExprIntoOneUnit(*this, Init, Init->getType(), CurPtr, + AggValueSlot::DoesNotOverlap); + + // Leave the Cleanup if we entered one. + if (CleanupDominator) { + DeactivateCleanupBlock(Cleanup, CleanupDominator); + CleanupDominator->eraseFromParent(); + } + + // Advance to the next element by adjusting the pointer type as necessary. + llvm::Value *NextPtr = + Builder.CreateConstInBoundsGEP1_32(ElementTy, CurPtr.getPointer(), 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); + CurPtrPhi->addIncoming(NextPtr, Builder.GetInsertBlock()); + + EmitBlock(ContBB); +} + +static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E, + QualType ElementType, llvm::Type *ElementTy, + Address NewPtr, llvm::Value *NumElements, + llvm::Value *AllocSizeWithoutCookie) { + ApplyDebugLocation DL(CGF, E); + if (E->isArray()) + CGF.EmitNewArrayInitializer(E, ElementType, ElementTy, NewPtr, NumElements, + AllocSizeWithoutCookie); + else if (const Expr *Init = E->getInitializer()) + StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr, + AggValueSlot::DoesNotOverlap); +} + +/// Emit a call to an operator new or operator delete function, as implicitly +/// created by new-expressions and delete-expressions. +static RValue EmitNewDeleteCall(CodeGenFunction &CGF, + const FunctionDecl *CalleeDecl, + const FunctionProtoType *CalleeType, + const CallArgList &Args) { + llvm::CallBase *CallOrInvoke; + llvm::Constant *CalleePtr = CGF.CGM.GetAddrOfFunction(CalleeDecl); + CGCallee Callee = CGCallee::forDirect(CalleePtr, GlobalDecl(CalleeDecl)); + RValue RV = + CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall( + Args, CalleeType, /*ChainCall=*/false), + Callee, ReturnValueSlot(), Args, &CallOrInvoke); + + /// C++1y [expr.new]p10: + /// [In a new-expression,] an implementation is allowed to omit a call + /// to a replaceable global allocation function. + /// + /// We model such elidable calls with the 'builtin' attribute. + llvm::Function *Fn = dyn_cast<llvm::Function>(CalleePtr); + if (CalleeDecl->isReplaceableGlobalAllocationFunction() && + Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) { + CallOrInvoke->addAttribute(llvm::AttributeList::FunctionIndex, + llvm::Attribute::Builtin); + } + + return RV; +} + +RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type, + const CallExpr *TheCall, + bool IsDelete) { + CallArgList Args; + EmitCallArgs(Args, Type->getParamTypes(), TheCall->arguments()); + // Find the allocation or deallocation function that we're calling. + ASTContext &Ctx = getContext(); + DeclarationName Name = Ctx.DeclarationNames + .getCXXOperatorName(IsDelete ? OO_Delete : OO_New); + + for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name)) + if (auto *FD = dyn_cast<FunctionDecl>(Decl)) + if (Ctx.hasSameType(FD->getType(), QualType(Type, 0))) + return EmitNewDeleteCall(*this, FD, Type, Args); + llvm_unreachable("predeclared global operator new/delete is missing"); +} + +namespace { +/// The parameters to pass to a usual operator delete. +struct UsualDeleteParams { + bool DestroyingDelete = false; + bool Size = false; + bool Alignment = false; +}; +} + +static UsualDeleteParams getUsualDeleteParams(const FunctionDecl *FD) { + UsualDeleteParams Params; + + const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>(); + auto AI = FPT->param_type_begin(), AE = FPT->param_type_end(); + + // The first argument is always a void*. + ++AI; + + // The next parameter may be a std::destroying_delete_t. + if (FD->isDestroyingOperatorDelete()) { + Params.DestroyingDelete = true; + assert(AI != AE); + ++AI; + } + + // Figure out what other parameters we should be implicitly passing. + if (AI != AE && (*AI)->isIntegerType()) { + Params.Size = true; + ++AI; + } + + if (AI != AE && (*AI)->isAlignValT()) { + Params.Alignment = true; + ++AI; + } + + assert(AI == AE && "unexpected usual deallocation function parameter"); + return Params; +} + +namespace { + /// A cleanup to call the given 'operator delete' function upon abnormal + /// exit from a new expression. Templated on a traits type that deals with + /// ensuring that the arguments dominate the cleanup if necessary. + template<typename Traits> + class CallDeleteDuringNew final : public EHScopeStack::Cleanup { + /// Type used to hold llvm::Value*s. + typedef typename Traits::ValueTy ValueTy; + /// Type used to hold RValues. + typedef typename Traits::RValueTy RValueTy; + struct PlacementArg { + RValueTy ArgValue; + QualType ArgType; + }; + + unsigned NumPlacementArgs : 31; + unsigned PassAlignmentToPlacementDelete : 1; + const FunctionDecl *OperatorDelete; + ValueTy Ptr; + ValueTy AllocSize; + CharUnits AllocAlign; + + PlacementArg *getPlacementArgs() { + return reinterpret_cast<PlacementArg *>(this + 1); + } + + public: + static size_t getExtraSize(size_t NumPlacementArgs) { + return NumPlacementArgs * sizeof(PlacementArg); + } + + CallDeleteDuringNew(size_t NumPlacementArgs, + const FunctionDecl *OperatorDelete, ValueTy Ptr, + ValueTy AllocSize, bool PassAlignmentToPlacementDelete, + CharUnits AllocAlign) + : NumPlacementArgs(NumPlacementArgs), + PassAlignmentToPlacementDelete(PassAlignmentToPlacementDelete), + OperatorDelete(OperatorDelete), Ptr(Ptr), AllocSize(AllocSize), + AllocAlign(AllocAlign) {} + + void setPlacementArg(unsigned I, RValueTy Arg, QualType Type) { + assert(I < NumPlacementArgs && "index out of range"); + getPlacementArgs()[I] = {Arg, Type}; + } + + void Emit(CodeGenFunction &CGF, Flags flags) override { + const FunctionProtoType *FPT = + OperatorDelete->getType()->getAs<FunctionProtoType>(); + CallArgList DeleteArgs; + + // The first argument is always a void* (or C* for a destroying operator + // delete for class type C). + DeleteArgs.add(Traits::get(CGF, Ptr), FPT->getParamType(0)); + + // Figure out what other parameters we should be implicitly passing. + UsualDeleteParams Params; + if (NumPlacementArgs) { + // A placement deallocation function is implicitly passed an alignment + // if the placement allocation function was, but is never passed a size. + Params.Alignment = PassAlignmentToPlacementDelete; + } else { + // For a non-placement new-expression, 'operator delete' can take a + // size and/or an alignment if it has the right parameters. + Params = getUsualDeleteParams(OperatorDelete); + } + + assert(!Params.DestroyingDelete && + "should not call destroying delete in a new-expression"); + + // The second argument can be a std::size_t (for non-placement delete). + if (Params.Size) + DeleteArgs.add(Traits::get(CGF, AllocSize), + CGF.getContext().getSizeType()); + + // The next (second or third) argument can be a std::align_val_t, which + // is an enum whose underlying type is std::size_t. + // FIXME: Use the right type as the parameter type. Note that in a call + // to operator delete(size_t, ...), we may not have it available. + if (Params.Alignment) + DeleteArgs.add(RValue::get(llvm::ConstantInt::get( + CGF.SizeTy, AllocAlign.getQuantity())), + CGF.getContext().getSizeType()); + + // Pass the rest of the arguments, which must match exactly. + for (unsigned I = 0; I != NumPlacementArgs; ++I) { + auto Arg = getPlacementArgs()[I]; + DeleteArgs.add(Traits::get(CGF, Arg.ArgValue), Arg.ArgType); + } + + // Call 'operator delete'. + EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs); + } + }; +} + +/// Enter a cleanup to call 'operator delete' if the initializer in a +/// new-expression throws. +static void EnterNewDeleteCleanup(CodeGenFunction &CGF, + const CXXNewExpr *E, + Address NewPtr, + llvm::Value *AllocSize, + CharUnits AllocAlign, + const CallArgList &NewArgs) { + unsigned NumNonPlacementArgs = E->passAlignment() ? 2 : 1; + + // 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()) { + struct DirectCleanupTraits { + typedef llvm::Value *ValueTy; + typedef RValue RValueTy; + static RValue get(CodeGenFunction &, ValueTy V) { return RValue::get(V); } + static RValue get(CodeGenFunction &, RValueTy V) { return V; } + }; + + typedef CallDeleteDuringNew<DirectCleanupTraits> DirectCleanup; + + DirectCleanup *Cleanup = CGF.EHStack + .pushCleanupWithExtra<DirectCleanup>(EHCleanup, + E->getNumPlacementArgs(), + E->getOperatorDelete(), + NewPtr.getPointer(), + AllocSize, + E->passAlignment(), + AllocAlign); + for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) { + auto &Arg = NewArgs[I + NumNonPlacementArgs]; + Cleanup->setPlacementArg(I, Arg.getRValue(CGF), Arg.Ty); + } + + return; + } + + // Otherwise, we need to save all this stuff. + DominatingValue<RValue>::saved_type SavedNewPtr = + DominatingValue<RValue>::save(CGF, RValue::get(NewPtr.getPointer())); + DominatingValue<RValue>::saved_type SavedAllocSize = + DominatingValue<RValue>::save(CGF, RValue::get(AllocSize)); + + struct ConditionalCleanupTraits { + typedef DominatingValue<RValue>::saved_type ValueTy; + typedef DominatingValue<RValue>::saved_type RValueTy; + static RValue get(CodeGenFunction &CGF, ValueTy V) { + return V.restore(CGF); + } + }; + typedef CallDeleteDuringNew<ConditionalCleanupTraits> ConditionalCleanup; + + ConditionalCleanup *Cleanup = CGF.EHStack + .pushCleanupWithExtra<ConditionalCleanup>(EHCleanup, + E->getNumPlacementArgs(), + E->getOperatorDelete(), + SavedNewPtr, + SavedAllocSize, + E->passAlignment(), + AllocAlign); + for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) { + auto &Arg = NewArgs[I + NumNonPlacementArgs]; + Cleanup->setPlacementArg( + I, DominatingValue<RValue>::save(CGF, Arg.getRValue(CGF)), Arg.Ty); + } + + 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(); + + // If there is a brace-initializer, cannot allocate fewer elements than inits. + unsigned minElements = 0; + if (E->isArray() && E->hasInitializer()) { + const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer()); + if (ILE && ILE->isStringLiteralInit()) + minElements = + cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe()) + ->getSize().getZExtValue(); + else if (ILE) + minElements = ILE->getNumInits(); + } + + llvm::Value *numElements = nullptr; + llvm::Value *allocSizeWithoutCookie = nullptr; + llvm::Value *allocSize = + EmitCXXNewAllocSize(*this, E, minElements, numElements, + allocSizeWithoutCookie); + CharUnits allocAlign = getContext().getTypeAlignInChars(allocType); + + // Emit the allocation call. If the allocator is a global placement + // operator, just "inline" it directly. + Address allocation = Address::invalid(); + CallArgList allocatorArgs; + if (allocator->isReservedGlobalPlacementOperator()) { + assert(E->getNumPlacementArgs() == 1); + const Expr *arg = *E->placement_arguments().begin(); + + LValueBaseInfo BaseInfo; + allocation = EmitPointerWithAlignment(arg, &BaseInfo); + + // The pointer expression will, in many cases, be an opaque void*. + // In these cases, discard the computed alignment and use the + // formal alignment of the allocated type. + if (BaseInfo.getAlignmentSource() != AlignmentSource::Decl) + allocation = Address(allocation.getPointer(), allocAlign); + + // Set up allocatorArgs for the call to operator delete if it's not + // the reserved global operator. + if (E->getOperatorDelete() && + !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) { + allocatorArgs.add(RValue::get(allocSize), getContext().getSizeType()); + allocatorArgs.add(RValue::get(allocation.getPointer()), arg->getType()); + } + + } else { + const FunctionProtoType *allocatorType = + allocator->getType()->castAs<FunctionProtoType>(); + unsigned ParamsToSkip = 0; + + // The allocation size is the first argument. + QualType sizeType = getContext().getSizeType(); + allocatorArgs.add(RValue::get(allocSize), sizeType); + ++ParamsToSkip; + + if (allocSize != allocSizeWithoutCookie) { + CharUnits cookieAlign = getSizeAlign(); // FIXME: Ask the ABI. + allocAlign = std::max(allocAlign, cookieAlign); + } + + // The allocation alignment may be passed as the second argument. + if (E->passAlignment()) { + QualType AlignValT = sizeType; + if (allocatorType->getNumParams() > 1) { + AlignValT = allocatorType->getParamType(1); + assert(getContext().hasSameUnqualifiedType( + AlignValT->castAs<EnumType>()->getDecl()->getIntegerType(), + sizeType) && + "wrong type for alignment parameter"); + ++ParamsToSkip; + } else { + // Corner case, passing alignment to 'operator new(size_t, ...)'. + assert(allocator->isVariadic() && "can't pass alignment to allocator"); + } + allocatorArgs.add( + RValue::get(llvm::ConstantInt::get(SizeTy, allocAlign.getQuantity())), + AlignValT); + } + + // FIXME: Why do we not pass a CalleeDecl here? + EmitCallArgs(allocatorArgs, allocatorType, E->placement_arguments(), + /*AC*/AbstractCallee(), /*ParamsToSkip*/ParamsToSkip); + + RValue RV = + EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs); + + // If this was a call to a global replaceable allocation function that does + // not take an alignment argument, the allocator is known to produce + // storage that's suitably aligned for any object that fits, up to a known + // threshold. Otherwise assume it's suitably aligned for the allocated type. + CharUnits allocationAlign = allocAlign; + if (!E->passAlignment() && + allocator->isReplaceableGlobalAllocationFunction()) { + unsigned AllocatorAlign = llvm::PowerOf2Floor(std::min<uint64_t>( + Target.getNewAlign(), getContext().getTypeSize(allocType))); + allocationAlign = std::max( + allocationAlign, getContext().toCharUnitsFromBits(AllocatorAlign)); + } + + allocation = Address(RV.getScalarVal(), allocationAlign); + } + + // 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 or is the reserved placement new) and we have an + // interesting initializer will be running sanitizers on the initialization. + bool nullCheck = E->shouldNullCheckAllocation() && + (!allocType.isPODType(getContext()) || E->hasInitializer() || + sanitizePerformTypeCheck()); + + llvm::BasicBlock *nullCheckBB = nullptr; + llvm::BasicBlock *contBB = nullptr; + + // 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.getPointer(), "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 = nullptr; + if (E->getOperatorDelete() && + !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) { + EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocAlign, + 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 *elementTy = ConvertTypeForMem(allocType); + Address result = Builder.CreateElementBitCast(allocation, elementTy); + + // Passing pointer through launder.invariant.group to avoid propagation of + // vptrs information which may be included in previous type. + // To not break LTO with different optimizations levels, we do it regardless + // of optimization level. + if (CGM.getCodeGenOpts().StrictVTablePointers && + allocator->isReservedGlobalPlacementOperator()) + result = Address(Builder.CreateLaunderInvariantGroup(result.getPointer()), + result.getAlignment()); + + // Emit sanitizer checks for pointer value now, so that in the case of an + // array it was checked only once and not at each constructor call. We may + // have already checked that the pointer is non-null. + // FIXME: If we have an array cookie and a potentially-throwing allocator, + // we'll null check the wrong pointer here. + SanitizerSet SkippedChecks; + SkippedChecks.set(SanitizerKind::Null, nullCheck); + EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall, + E->getAllocatedTypeSourceInfo()->getTypeLoc().getBeginLoc(), + result.getPointer(), allocType, result.getAlignment(), + SkippedChecks, numElements); + + EmitNewInitializer(*this, E, allocType, elementTy, 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(); + } + + llvm::Value *resultPtr = result.getPointer(); + if (nullCheck) { + conditional.end(*this); + + llvm::BasicBlock *notNullBB = Builder.GetInsertBlock(); + EmitBlock(contBB); + + llvm::PHINode *PHI = Builder.CreatePHI(resultPtr->getType(), 2); + PHI->addIncoming(resultPtr, notNullBB); + PHI->addIncoming(llvm::Constant::getNullValue(resultPtr->getType()), + nullCheckBB); + + resultPtr = PHI; + } + + return resultPtr; +} + +void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD, + llvm::Value *Ptr, QualType DeleteTy, + llvm::Value *NumElements, + CharUnits CookieSize) { + assert((!NumElements && CookieSize.isZero()) || + DeleteFD->getOverloadedOperator() == OO_Array_Delete); + + const FunctionProtoType *DeleteFTy = + DeleteFD->getType()->getAs<FunctionProtoType>(); + + CallArgList DeleteArgs; + + auto Params = getUsualDeleteParams(DeleteFD); + auto ParamTypeIt = DeleteFTy->param_type_begin(); + + // Pass the pointer itself. + QualType ArgTy = *ParamTypeIt++; + llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy)); + DeleteArgs.add(RValue::get(DeletePtr), ArgTy); + + // Pass the std::destroying_delete tag if present. + if (Params.DestroyingDelete) { + QualType DDTag = *ParamTypeIt++; + // Just pass an 'undef'. We expect the tag type to be an empty struct. + auto *V = llvm::UndefValue::get(getTypes().ConvertType(DDTag)); + DeleteArgs.add(RValue::get(V), DDTag); + } + + // Pass the size if the delete function has a size_t parameter. + if (Params.Size) { + QualType SizeType = *ParamTypeIt++; + CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy); + llvm::Value *Size = llvm::ConstantInt::get(ConvertType(SizeType), + DeleteTypeSize.getQuantity()); + + // For array new, multiply by the number of elements. + if (NumElements) + Size = Builder.CreateMul(Size, NumElements); + + // If there is a cookie, add the cookie size. + if (!CookieSize.isZero()) + Size = Builder.CreateAdd( + Size, llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity())); + + DeleteArgs.add(RValue::get(Size), SizeType); + } + + // Pass the alignment if the delete function has an align_val_t parameter. + if (Params.Alignment) { + QualType AlignValType = *ParamTypeIt++; + CharUnits DeleteTypeAlign = getContext().toCharUnitsFromBits( + getContext().getTypeAlignIfKnown(DeleteTy)); + llvm::Value *Align = llvm::ConstantInt::get(ConvertType(AlignValType), + DeleteTypeAlign.getQuantity()); + DeleteArgs.add(RValue::get(Align), AlignValType); + } + + assert(ParamTypeIt == DeleteFTy->param_type_end() && + "unknown parameter to usual delete function"); + + // Emit the call to delete. + EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs); +} + +namespace { + /// Calls the given 'operator delete' on a single object. + struct CallObjectDelete final : 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) override { + CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType); + } + }; +} + +void +CodeGenFunction::pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete, + llvm::Value *CompletePtr, + QualType ElementType) { + EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, CompletePtr, + OperatorDelete, ElementType); +} + +/// Emit the code for deleting a single object with a destroying operator +/// delete. If the element type has a non-virtual destructor, Ptr has already +/// been converted to the type of the parameter of 'operator delete'. Otherwise +/// Ptr points to an object of the static type. +static void EmitDestroyingObjectDelete(CodeGenFunction &CGF, + const CXXDeleteExpr *DE, Address Ptr, + QualType ElementType) { + auto *Dtor = ElementType->getAsCXXRecordDecl()->getDestructor(); + if (Dtor && Dtor->isVirtual()) + CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType, + Dtor); + else + CGF.EmitDeleteCall(DE->getOperatorDelete(), Ptr.getPointer(), ElementType); +} + +/// Emit the code for deleting a single object. +static void EmitObjectDelete(CodeGenFunction &CGF, + const CXXDeleteExpr *DE, + Address Ptr, + QualType ElementType) { + // C++11 [expr.delete]p3: + // If the static type of the object to be deleted is different from its + // dynamic type, the static type shall be a base class of the dynamic type + // of the object to be deleted and the static type shall have a virtual + // destructor or the behavior is undefined. + CGF.EmitTypeCheck(CodeGenFunction::TCK_MemberCall, + DE->getExprLoc(), Ptr.getPointer(), + ElementType); + + const FunctionDecl *OperatorDelete = DE->getOperatorDelete(); + assert(!OperatorDelete->isDestroyingOperatorDelete()); + + // Find the destructor for the type, if applicable. If the + // destructor is virtual, we'll just emit the vcall and return. + const CXXDestructorDecl *Dtor = nullptr; + if (const RecordType *RT = ElementType->getAs<RecordType>()) { + CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->hasDefinition() && !RD->hasTrivialDestructor()) { + Dtor = RD->getDestructor(); + + if (Dtor->isVirtual()) { + bool UseVirtualCall = true; + const Expr *Base = DE->getArgument(); + if (auto *DevirtualizedDtor = + dyn_cast_or_null<const CXXDestructorDecl>( + Dtor->getDevirtualizedMethod( + Base, CGF.CGM.getLangOpts().AppleKext))) { + UseVirtualCall = false; + const CXXRecordDecl *DevirtualizedClass = + DevirtualizedDtor->getParent(); + if (declaresSameEntity(getCXXRecord(Base), DevirtualizedClass)) { + // Devirtualized to the class of the base type (the type of the + // whole expression). + Dtor = DevirtualizedDtor; + } else { + // Devirtualized to some other type. Would need to cast the this + // pointer to that type but we don't have support for that yet, so + // do a virtual call. FIXME: handle the case where it is + // devirtualized to the derived type (the type of the inner + // expression) as in EmitCXXMemberOrOperatorMemberCallExpr. + UseVirtualCall = true; + } + } + if (UseVirtualCall) { + CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType, + Dtor); + 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.getPointer(), + OperatorDelete, ElementType); + + if (Dtor) + CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, + /*ForVirtualBase=*/false, + /*Delegating=*/false, + Ptr, ElementType); + else if (auto Lifetime = ElementType.getObjCLifetime()) { + switch (Lifetime) { + case Qualifiers::OCL_None: + case Qualifiers::OCL_ExplicitNone: + case Qualifiers::OCL_Autoreleasing: + break; + + case Qualifiers::OCL_Strong: + CGF.EmitARCDestroyStrong(Ptr, ARCPreciseLifetime); + break; + + case Qualifiers::OCL_Weak: + CGF.EmitARCDestroyWeak(Ptr); + break; + } + } + + CGF.PopCleanupBlock(); +} + +namespace { + /// Calls the given 'operator delete' on an array of objects. + struct CallArrayDelete final : 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) override { + CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType, NumElements, + CookieSize); + } + }; +} + +/// Emit the code for deleting an array of objects. +static void EmitArrayDelete(CodeGenFunction &CGF, + const CXXDeleteExpr *E, + Address deletedPtr, + QualType elementType) { + llvm::Value *numElements = nullptr; + llvm::Value *allocatedPtr = nullptr; + 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!"); + + CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType); + CharUnits elementAlign = + deletedPtr.getAlignment().alignmentOfArrayElement(elementSize); + + llvm::Value *arrayBegin = deletedPtr.getPointer(); + llvm::Value *arrayEnd = + CGF.Builder.CreateInBoundsGEP(arrayBegin, 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(arrayBegin, arrayEnd, elementType, elementAlign, + CGF.getDestroyer(dtorKind), + /*checkZeroLength*/ true, + CGF.needsEHCleanup(dtorKind)); + } + + // Pop the cleanup block. + CGF.PopCleanupBlock(); +} + +void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) { + const Expr *Arg = E->getArgument(); + Address Ptr = EmitPointerWithAlignment(Arg); + + // Null check the pointer. + llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull"); + llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end"); + + llvm::Value *IsNull = Builder.CreateIsNull(Ptr.getPointer(), "isnull"); + + Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull); + EmitBlock(DeleteNotNull); + + QualType DeleteTy = E->getDestroyedType(); + + // A destroying operator delete overrides the entire operation of the + // delete expression. + if (E->getOperatorDelete()->isDestroyingOperatorDelete()) { + EmitDestroyingObjectDelete(*this, E, Ptr, DeleteTy); + EmitBlock(DeleteEnd); + return; + } + + // 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]]*) + 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 = Address(Builder.CreateInBoundsGEP(Ptr.getPointer(), GEP, "del.first"), + Ptr.getAlignment()); + } + + assert(ConvertTypeForMem(DeleteTy) == Ptr.getElementType()); + + if (E->isArrayForm()) { + EmitArrayDelete(*this, E, Ptr, DeleteTy); + } else { + EmitObjectDelete(*this, E, Ptr, DeleteTy); + } + + EmitBlock(DeleteEnd); +} + +static bool isGLValueFromPointerDeref(const Expr *E) { + E = E->IgnoreParens(); + + if (const auto *CE = dyn_cast<CastExpr>(E)) { + if (!CE->getSubExpr()->isGLValue()) + return false; + return isGLValueFromPointerDeref(CE->getSubExpr()); + } + + if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) + return isGLValueFromPointerDeref(OVE->getSourceExpr()); + + if (const auto *BO = dyn_cast<BinaryOperator>(E)) + if (BO->getOpcode() == BO_Comma) + return isGLValueFromPointerDeref(BO->getRHS()); + + if (const auto *ACO = dyn_cast<AbstractConditionalOperator>(E)) + return isGLValueFromPointerDeref(ACO->getTrueExpr()) || + isGLValueFromPointerDeref(ACO->getFalseExpr()); + + // C++11 [expr.sub]p1: + // The expression E1[E2] is identical (by definition) to *((E1)+(E2)) + if (isa<ArraySubscriptExpr>(E)) + return true; + + if (const auto *UO = dyn_cast<UnaryOperator>(E)) + if (UO->getOpcode() == UO_Deref) + return true; + + return false; +} + +static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E, + llvm::Type *StdTypeInfoPtrTy) { + // Get the vtable pointer. + Address ThisPtr = CGF.EmitLValue(E).getAddress(); + + QualType SrcRecordTy = E->getType(); + + // C++ [class.cdtor]p4: + // If the operand of typeid refers to the object under construction or + // destruction and the static type of the operand is neither the constructor + // or destructor’s class nor one of its bases, the behavior is undefined. + CGF.EmitTypeCheck(CodeGenFunction::TCK_DynamicOperation, E->getExprLoc(), + ThisPtr.getPointer(), SrcRecordTy); + + // 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. + // + // However, this paragraph's intent is not clear. We choose a very generous + // interpretation which implores us to consider comma operators, conditional + // operators, parentheses and other such constructs. + if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked( + isGLValueFromPointerDeref(E), SrcRecordTy)) { + llvm::BasicBlock *BadTypeidBlock = + CGF.createBasicBlock("typeid.bad_typeid"); + llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end"); + + llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr.getPointer()); + CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock); + + CGF.EmitBlock(BadTypeidBlock); + CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF); + CGF.EmitBlock(EndBlock); + } + + return CGF.CGM.getCXXABI().EmitTypeid(CGF, SrcRecordTy, ThisPtr, + StdTypeInfoPtrTy); +} + +llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) { + llvm::Type *StdTypeInfoPtrTy = + ConvertType(E->getType())->getPointerTo(); + + if (E->isTypeOperand()) { + llvm::Constant *TypeInfo = + CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand(getContext())); + 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->isPotentiallyEvaluated()) + return EmitTypeidFromVTable(*this, E->getExprOperand(), + StdTypeInfoPtrTy); + + QualType OperandTy = E->getExprOperand()->getType(); + return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy), + StdTypeInfoPtrTy); +} + +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 + if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF)) + return nullptr; + + CGF.EmitBlock(CGF.createBasicBlock("dynamic_cast.end")); + return llvm::UndefValue::get(DestLTy); +} + +llvm::Value *CodeGenFunction::EmitDynamicCast(Address ThisAddr, + const CXXDynamicCastExpr *DCE) { + CGM.EmitExplicitCastExprType(DCE, this); + QualType DestTy = DCE->getTypeAsWritten(); + + QualType SrcTy = DCE->getSubExpr()->getType(); + + // 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. + const PointerType *DestPTy = DestTy->getAs<PointerType>(); + + bool isDynamicCastToVoid; + QualType SrcRecordTy; + QualType DestRecordTy; + if (DestPTy) { + isDynamicCastToVoid = DestPTy->getPointeeType()->isVoidType(); + SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType(); + DestRecordTy = DestPTy->getPointeeType(); + } else { + isDynamicCastToVoid = false; + SrcRecordTy = SrcTy; + DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType(); + } + + // C++ [class.cdtor]p5: + // If the operand of the dynamic_cast refers to the object under + // construction or destruction and the static type of the operand is not a + // pointer to or object of the constructor or destructor’s own class or one + // of its bases, the dynamic_cast results in undefined behavior. + EmitTypeCheck(TCK_DynamicOperation, DCE->getExprLoc(), ThisAddr.getPointer(), + SrcRecordTy); + + if (DCE->isAlwaysNull()) + if (llvm::Value *T = EmitDynamicCastToNull(*this, DestTy)) + return T; + + assert(SrcRecordTy->isRecordType() && "source type must be a record type!"); + + // 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 = + CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(SrcTy->isPointerType(), + SrcRecordTy); + + llvm::BasicBlock *CastNull = nullptr; + llvm::BasicBlock *CastNotNull = nullptr; + llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end"); + + if (ShouldNullCheckSrcValue) { + CastNull = createBasicBlock("dynamic_cast.null"); + CastNotNull = createBasicBlock("dynamic_cast.notnull"); + + llvm::Value *IsNull = Builder.CreateIsNull(ThisAddr.getPointer()); + Builder.CreateCondBr(IsNull, CastNull, CastNotNull); + EmitBlock(CastNotNull); + } + + llvm::Value *Value; + if (isDynamicCastToVoid) { + Value = CGM.getCXXABI().EmitDynamicCastToVoid(*this, ThisAddr, SrcRecordTy, + DestTy); + } else { + assert(DestRecordTy->isRecordType() && + "destination type must be a record type!"); + Value = CGM.getCXXABI().EmitDynamicCastCall(*this, ThisAddr, SrcRecordTy, + DestTy, DestRecordTy, CastEnd); + CastNotNull = Builder.GetInsertBlock(); + } + + 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; +} |