| //===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code dealing with code generation of C++ expressions |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenFunction.h" |
| #include "CGCUDARuntime.h" |
| #include "CGCXXABI.h" |
| #include "CGDebugInfo.h" |
| #include "CGObjCRuntime.h" |
| #include "clang/Frontend/CodeGenOptions.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/Support/CallSite.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD, |
| SourceLocation CallLoc, |
| llvm::Value *Callee, |
| ReturnValueSlot ReturnValue, |
| llvm::Value *This, |
| llvm::Value *ImplicitParam, |
| QualType ImplicitParamTy, |
| CallExpr::const_arg_iterator ArgBeg, |
| CallExpr::const_arg_iterator ArgEnd) { |
| assert(MD->isInstance() && |
| "Trying to emit a member call expr on a static method!"); |
| |
| // 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. |
| EmitTypeCheck(isa<CXXConstructorDecl>(MD) ? TCK_ConstructorCall |
| : TCK_MemberCall, |
| CallLoc, This, getContext().getRecordType(MD->getParent())); |
| |
| CallArgList Args; |
| |
| // Push the this ptr. |
| Args.add(RValue::get(This), MD->getThisType(getContext())); |
| |
| // 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()); |
| |
| // And the rest of the call args. |
| EmitCallArgs(Args, FPT, ArgBeg, ArgEnd); |
| |
| return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required), |
| Callee, ReturnValue, Args, MD); |
| } |
| |
| // 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 = Base->getBestDynamicClassType(); |
| 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 devirtualize calls on an object accessed by a class member access |
| // expression, since by C++11 [basic.life]p6 we know that it can't refer to |
| // a derived class object constructed in the same location. |
| if (const MemberExpr *ME = dyn_cast<MemberExpr>(Base)) |
| if (const ValueDecl *VD = dyn_cast<ValueDecl>(ME->getMemberDecl())) |
| return VD->getType()->isRecordType(); |
| |
| // 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; |
| } |
| |
| 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()); |
| |
| CGDebugInfo *DI = getDebugInfo(); |
| if (DI && |
| CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::LimitedDebugInfo && |
| !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. |
| const Expr *Base = ME->getBase(); |
| bool CanUseVirtualCall = MD->isVirtual() && !ME->hasQualifier(); |
| |
| const CXXMethodDecl *DevirtualizedMethod = NULL; |
| if (CanUseVirtualCall && |
| canDevirtualizeMemberFunctionCalls(getContext(), Base, MD)) { |
| const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType(); |
| DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl); |
| assert(DevirtualizedMethod); |
| const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent(); |
| const Expr *Inner = Base->ignoreParenBaseCasts(); |
| 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 = NULL; |
| } |
| // 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. |
| if (DevirtualizedMethod && |
| DevirtualizedMethod->getResultType().getCanonicalType() != |
| MD->getResultType().getCanonicalType()) |
| DevirtualizedMethod = NULL; |
| } |
| |
| llvm::Value *This; |
| if (ME->isArrow()) |
| This = EmitScalarExpr(Base); |
| else |
| This = EmitLValue(Base).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(); |
| EmitAggregateAssign(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 CXXMethodDecl *CalleeDecl = DevirtualizedMethod ? DevirtualizedMethod : MD; |
| const CGFunctionInfo *FInfo = 0; |
| if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl)) |
| FInfo = &CGM.getTypes().arrangeCXXDestructor(Dtor, |
| Dtor_Complete); |
| else if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(CalleeDecl)) |
| FInfo = &CGM.getTypes().arrangeCXXConstructorDeclaration(Ctor, |
| Ctor_Complete); |
| else |
| FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl); |
| |
| 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 = CanUseVirtualCall && !DevirtualizedMethod; |
| |
| llvm::Value *Callee; |
| if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) { |
| if (UseVirtualCall) { |
| Callee = BuildVirtualCall(Dtor, Dtor_Complete, This, Ty); |
| } else { |
| if (getLangOpts().AppleKext && |
| MD->isVirtual() && |
| ME->hasQualifier()) |
| Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty); |
| else if (!DevirtualizedMethod) |
| Callee = CGM.GetAddrOfFunction(GlobalDecl(Dtor, Dtor_Complete), Ty); |
| else { |
| const CXXDestructorDecl *DDtor = |
| cast<CXXDestructorDecl>(DevirtualizedMethod); |
| Callee = CGM.GetAddrOfFunction(GlobalDecl(DDtor, 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 (getLangOpts().AppleKext && |
| MD->isVirtual() && |
| ME->hasQualifier()) |
| Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty); |
| else if (!DevirtualizedMethod) |
| Callee = CGM.GetAddrOfFunction(MD, Ty); |
| else { |
| Callee = CGM.GetAddrOfFunction(DevirtualizedMethod, Ty); |
| } |
| } |
| |
| return EmitCXXMemberCall(MD, CE->getExprLoc(), Callee, ReturnValue, This, |
| /*ImplicitParam=*/0, QualType(), |
| 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(); |
| |
| EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This, |
| QualType(MPT->getClass(), 0)); |
| |
| // 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); |
| |
| RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1); |
| |
| // And the rest of the call args |
| EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end()); |
| return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required), 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(); |
| EmitAggregateAssign(This, Src, Ty); |
| return RValue::get(This); |
| } |
| |
| llvm::Value *Callee = EmitCXXOperatorMemberCallee(E, MD, This); |
| return EmitCXXMemberCall(MD, E->getExprLoc(), Callee, ReturnValue, This, |
| /*ImplicitParam=*/0, QualType(), |
| 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: |
| 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 (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; |
| 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; |
| // fall-through |
| |
| case CXXConstructExpr::CK_NonVirtualBase: |
| Type = Ctor_Base; |
| } |
| |
| // Call the constructor. |
| EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating, 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(); |
| 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; |
| } |
| } |
| |
| CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr, |
| CCE->arg_begin(), CCE->arg_end(), |
| CCE->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().arrangeFreeFunctionCall(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().arrangeFreeFunctionCall(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().arrangeFreeFunctionCall(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 = allocation->getType()->getPointerAddressSpace(); |
| |
| // 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().arrangeFreeFunctionCall(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. |
| |
| // Derive the complete-object pointer, which is what we need |
| // to pass to the deallocation function. |
| llvm::Value *completePtr = |
| CGF.CGM.getCXXABI().adjustToCompleteObject(CGF, Ptr, ElementType); |
| |
| CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, |
| completePtr, 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); |
| // FIXME: Provide a source location here. |
| CGF.EmitCXXMemberCall(Dtor, SourceLocation(), Callee, ReturnValueSlot(), |
| Ptr, /*ImplicitParam=*/0, QualType(), 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, |
| /*Delegating=*/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().arrangeFreeFunctionCall(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) { |
| const Expr *Arg = E->getArgument(); |
| 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->isPotentiallyEvaluated()) |
| 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); |
| |
| // Mark the function as nounwind readonly. |
| llvm::Attribute::AttrKind FuncAttrs[] = { llvm::Attribute::NoUnwind, |
| llvm::Attribute::ReadOnly }; |
| llvm::AttributeSet Attrs = llvm::AttributeSet::get( |
| CGF.getLLVMContext(), llvm::AttributeSet::FunctionIndex, FuncAttrs); |
| |
| return CGF.CGM.CreateRuntimeFunction(FTy, "__dynamic_cast", Attrs); |
| } |
| |
| 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(); |
| } |
| |
| /// \brief Compute the src2dst_offset hint as described in the |
| /// Itanium C++ ABI [2.9.7] |
| static CharUnits computeOffsetHint(ASTContext &Context, |
| const CXXRecordDecl *Src, |
| const CXXRecordDecl *Dst) { |
| CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, |
| /*DetectVirtual=*/false); |
| |
| // If Dst is not derived from Src we can skip the whole computation below and |
| // return that Src is not a public base of Dst. Record all inheritance paths. |
| if (!Dst->isDerivedFrom(Src, Paths)) |
| return CharUnits::fromQuantity(-2ULL); |
| |
| unsigned NumPublicPaths = 0; |
| CharUnits Offset; |
| |
| // Now walk all possible inheritance paths. |
| for (CXXBasePaths::paths_iterator I = Paths.begin(), E = Paths.end(); |
| I != E; ++I) { |
| if (I->Access != AS_public) // Ignore non-public inheritance. |
| continue; |
| |
| ++NumPublicPaths; |
| |
| for (CXXBasePath::iterator J = I->begin(), JE = I->end(); J != JE; ++J) { |
| // If the path contains a virtual base class we can't give any hint. |
| // -1: no hint. |
| if (J->Base->isVirtual()) |
| return CharUnits::fromQuantity(-1ULL); |
| |
| if (NumPublicPaths > 1) // Won't use offsets, skip computation. |
| continue; |
| |
| // Accumulate the base class offsets. |
| const ASTRecordLayout &L = Context.getASTRecordLayout(J->Class); |
| Offset += L.getBaseClassOffset(J->Base->getType()->getAsCXXRecordDecl()); |
| } |
| } |
| |
| // -2: Src is not a public base of Dst. |
| if (NumPublicPaths == 0) |
| return CharUnits::fromQuantity(-2ULL); |
| |
| // -3: Src is a multiple public base type but never a virtual base type. |
| if (NumPublicPaths > 1) |
| return CharUnits::fromQuantity(-3ULL); |
| |
| // Otherwise, the Src type is a unique public nonvirtual base type of Dst. |
| // Return the offset of Src from the origin of Dst. |
| return Offset; |
| } |
| |
| 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()); |
| |
| // Compute the offset hint. |
| const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl(); |
| const CXXRecordDecl *DestDecl = DestRecordTy->getAsCXXRecordDecl(); |
| llvm::Value *OffsetHint = |
| llvm::ConstantInt::get(PtrDiffLTy, |
| computeOffsetHint(CGF.getContext(), SrcDecl, |
| DestDecl).getQuantity()); |
| |
| // 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); |
| } |
| } |