| //===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This provides C++ code generation targeting the Microsoft Visual C++ ABI. |
| // The class in this file generates structures that follow the Microsoft |
| // Visual C++ ABI, which is actually not very well documented at all outside |
| // of Microsoft. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CGCXXABI.h" |
| #include "CodeGenModule.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| namespace { |
| |
| class MicrosoftCXXABI : public CGCXXABI { |
| public: |
| MicrosoftCXXABI(CodeGenModule &CGM) : CGCXXABI(CGM) {} |
| |
| bool isReturnTypeIndirect(const CXXRecordDecl *RD) const { |
| // Structures that are not C++03 PODs are always indirect. |
| return !RD->isPOD(); |
| } |
| |
| RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const { |
| if (RD->hasNonTrivialCopyConstructor()) |
| return RAA_DirectInMemory; |
| return RAA_Default; |
| } |
| |
| StringRef GetPureVirtualCallName() { return "_purecall"; } |
| // No known support for deleted functions in MSVC yet, so this choice is |
| // arbitrary. |
| StringRef GetDeletedVirtualCallName() { return "_purecall"; } |
| |
| llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF, |
| llvm::Value *ptr, |
| QualType type); |
| |
| void BuildConstructorSignature(const CXXConstructorDecl *Ctor, |
| CXXCtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys); |
| |
| llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF); |
| |
| void BuildDestructorSignature(const CXXDestructorDecl *Ctor, |
| CXXDtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys); |
| |
| void BuildInstanceFunctionParams(CodeGenFunction &CGF, |
| QualType &ResTy, |
| FunctionArgList &Params); |
| |
| void EmitInstanceFunctionProlog(CodeGenFunction &CGF); |
| |
| llvm::Value *EmitConstructorCall(CodeGenFunction &CGF, |
| const CXXConstructorDecl *D, |
| CXXCtorType Type, bool ForVirtualBase, |
| bool Delegating, |
| llvm::Value *This, |
| CallExpr::const_arg_iterator ArgBeg, |
| CallExpr::const_arg_iterator ArgEnd); |
| |
| RValue EmitVirtualDestructorCall(CodeGenFunction &CGF, |
| const CXXDestructorDecl *Dtor, |
| CXXDtorType DtorType, |
| SourceLocation CallLoc, |
| ReturnValueSlot ReturnValue, |
| llvm::Value *This); |
| |
| void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D, |
| llvm::GlobalVariable *DeclPtr, |
| bool PerformInit); |
| |
| // ==== Notes on array cookies ========= |
| // |
| // MSVC seems to only use cookies when the class has a destructor; a |
| // two-argument usual array deallocation function isn't sufficient. |
| // |
| // For example, this code prints "100" and "1": |
| // struct A { |
| // char x; |
| // void *operator new[](size_t sz) { |
| // printf("%u\n", sz); |
| // return malloc(sz); |
| // } |
| // void operator delete[](void *p, size_t sz) { |
| // printf("%u\n", sz); |
| // free(p); |
| // } |
| // }; |
| // int main() { |
| // A *p = new A[100]; |
| // delete[] p; |
| // } |
| // Whereas it prints "104" and "104" if you give A a destructor. |
| |
| bool requiresArrayCookie(const CXXDeleteExpr *expr, QualType elementType); |
| bool requiresArrayCookie(const CXXNewExpr *expr); |
| CharUnits getArrayCookieSizeImpl(QualType type); |
| llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF, |
| llvm::Value *NewPtr, |
| llvm::Value *NumElements, |
| const CXXNewExpr *expr, |
| QualType ElementType); |
| llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF, |
| llvm::Value *allocPtr, |
| CharUnits cookieSize); |
| static bool needThisReturn(GlobalDecl GD); |
| |
| private: |
| llvm::Constant *getZeroInt() { |
| return llvm::ConstantInt::get(CGM.IntTy, 0); |
| } |
| |
| llvm::Constant *getAllOnesInt() { |
| return llvm::Constant::getAllOnesValue(CGM.IntTy); |
| } |
| |
| void |
| GetNullMemberPointerFields(const MemberPointerType *MPT, |
| llvm::SmallVectorImpl<llvm::Constant *> &fields); |
| |
| llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const CXXRecordDecl *RD, |
| llvm::Value *Base, |
| llvm::Value *VirtualBaseAdjustmentOffset, |
| llvm::Value *VBPtrOffset /* optional */); |
| |
| /// \brief Emits a full member pointer with the fields common to data and |
| /// function member pointers. |
| llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField, |
| bool IsMemberFunction, |
| const CXXRecordDecl *RD); |
| |
| public: |
| virtual llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT); |
| |
| virtual bool isZeroInitializable(const MemberPointerType *MPT); |
| |
| virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT); |
| |
| virtual llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT, |
| CharUnits offset); |
| virtual llvm::Constant *EmitMemberPointer(const CXXMethodDecl *MD); |
| virtual llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT); |
| |
| virtual llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF, |
| llvm::Value *L, |
| llvm::Value *R, |
| const MemberPointerType *MPT, |
| bool Inequality); |
| |
| virtual llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| virtual llvm::Value *EmitMemberDataPointerAddress(CodeGenFunction &CGF, |
| llvm::Value *Base, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| virtual llvm::Value * |
| EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, |
| llvm::Value *&This, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| }; |
| |
| } |
| |
| llvm::Value *MicrosoftCXXABI::adjustToCompleteObject(CodeGenFunction &CGF, |
| llvm::Value *ptr, |
| QualType type) { |
| // FIXME: implement |
| return ptr; |
| } |
| |
| bool MicrosoftCXXABI::needThisReturn(GlobalDecl GD) { |
| const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl()); |
| return isa<CXXConstructorDecl>(MD); |
| } |
| |
| void MicrosoftCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor, |
| CXXCtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys) { |
| // 'this' is already in place |
| |
| // Ctor returns this ptr |
| ResTy = ArgTys[0]; |
| |
| const CXXRecordDecl *Class = Ctor->getParent(); |
| if (Class->getNumVBases()) { |
| // Constructors of classes with virtual bases take an implicit parameter. |
| ArgTys.push_back(CGM.getContext().IntTy); |
| } |
| } |
| |
| llvm::BasicBlock *MicrosoftCXXABI::EmitCtorCompleteObjectHandler( |
| CodeGenFunction &CGF) { |
| llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF); |
| assert(IsMostDerivedClass && |
| "ctor for a class with virtual bases must have an implicit parameter"); |
| llvm::Value *IsCompleteObject |
| = CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object"); |
| |
| llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases"); |
| llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases"); |
| CGF.Builder.CreateCondBr(IsCompleteObject, |
| CallVbaseCtorsBB, SkipVbaseCtorsBB); |
| |
| CGF.EmitBlock(CallVbaseCtorsBB); |
| // FIXME: emit vbtables somewhere around here. |
| |
| // CGF will put the base ctor calls in this basic block for us later. |
| |
| return SkipVbaseCtorsBB; |
| } |
| |
| void MicrosoftCXXABI::BuildDestructorSignature(const CXXDestructorDecl *Dtor, |
| CXXDtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys) { |
| // 'this' is already in place |
| // TODO: 'for base' flag |
| |
| if (Type == Dtor_Deleting) { |
| // The scalar deleting destructor takes an implicit bool parameter. |
| ArgTys.push_back(CGM.getContext().BoolTy); |
| } |
| } |
| |
| static bool IsDeletingDtor(GlobalDecl GD) { |
| const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl()); |
| if (isa<CXXDestructorDecl>(MD)) { |
| return GD.getDtorType() == Dtor_Deleting; |
| } |
| return false; |
| } |
| |
| void MicrosoftCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF, |
| QualType &ResTy, |
| FunctionArgList &Params) { |
| BuildThisParam(CGF, Params); |
| if (needThisReturn(CGF.CurGD)) { |
| ResTy = Params[0]->getType(); |
| } |
| |
| ASTContext &Context = getContext(); |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl()); |
| if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) { |
| ImplicitParamDecl *IsMostDerived |
| = ImplicitParamDecl::Create(Context, 0, |
| CGF.CurGD.getDecl()->getLocation(), |
| &Context.Idents.get("is_most_derived"), |
| Context.IntTy); |
| Params.push_back(IsMostDerived); |
| getStructorImplicitParamDecl(CGF) = IsMostDerived; |
| } else if (IsDeletingDtor(CGF.CurGD)) { |
| ImplicitParamDecl *ShouldDelete |
| = ImplicitParamDecl::Create(Context, 0, |
| CGF.CurGD.getDecl()->getLocation(), |
| &Context.Idents.get("should_call_delete"), |
| Context.BoolTy); |
| Params.push_back(ShouldDelete); |
| getStructorImplicitParamDecl(CGF) = ShouldDelete; |
| } |
| } |
| |
| void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) { |
| EmitThisParam(CGF); |
| if (needThisReturn(CGF.CurGD)) { |
| CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue); |
| } |
| |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl()); |
| if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) { |
| assert(getStructorImplicitParamDecl(CGF) && |
| "no implicit parameter for a constructor with virtual bases?"); |
| getStructorImplicitParamValue(CGF) |
| = CGF.Builder.CreateLoad( |
| CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)), |
| "is_most_derived"); |
| } |
| |
| if (IsDeletingDtor(CGF.CurGD)) { |
| assert(getStructorImplicitParamDecl(CGF) && |
| "no implicit parameter for a deleting destructor?"); |
| getStructorImplicitParamValue(CGF) |
| = CGF.Builder.CreateLoad( |
| CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)), |
| "should_call_delete"); |
| } |
| } |
| |
| llvm::Value *MicrosoftCXXABI::EmitConstructorCall(CodeGenFunction &CGF, |
| const CXXConstructorDecl *D, |
| CXXCtorType Type, bool ForVirtualBase, |
| bool Delegating, |
| llvm::Value *This, |
| CallExpr::const_arg_iterator ArgBeg, |
| CallExpr::const_arg_iterator ArgEnd) { |
| assert(Type == Ctor_Complete || Type == Ctor_Base); |
| llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, Ctor_Complete); |
| |
| llvm::Value *ImplicitParam = 0; |
| QualType ImplicitParamTy; |
| if (D->getParent()->getNumVBases()) { |
| ImplicitParam = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete); |
| ImplicitParamTy = getContext().IntTy; |
| } |
| |
| // FIXME: Provide a source location here. |
| CGF.EmitCXXMemberCall(D, SourceLocation(), Callee, ReturnValueSlot(), This, |
| ImplicitParam, ImplicitParamTy, |
| ArgBeg, ArgEnd); |
| return Callee; |
| } |
| |
| RValue MicrosoftCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF, |
| const CXXDestructorDecl *Dtor, |
| CXXDtorType DtorType, |
| SourceLocation CallLoc, |
| ReturnValueSlot ReturnValue, |
| llvm::Value *This) { |
| assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete); |
| |
| // We have only one destructor in the vftable but can get both behaviors |
| // by passing an implicit bool parameter. |
| const CGFunctionInfo *FInfo |
| = &CGM.getTypes().arrangeCXXDestructor(Dtor, Dtor_Deleting); |
| llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo); |
| llvm::Value *Callee = CGF.BuildVirtualCall(Dtor, Dtor_Deleting, This, Ty); |
| |
| ASTContext &Context = CGF.getContext(); |
| llvm::Value *ImplicitParam |
| = llvm::ConstantInt::get(llvm::IntegerType::getInt1Ty(CGF.getLLVMContext()), |
| DtorType == Dtor_Deleting); |
| |
| return CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValue, This, |
| ImplicitParam, Context.BoolTy, 0, 0); |
| } |
| |
| bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr, |
| QualType elementType) { |
| // Microsoft seems to completely ignore the possibility of a |
| // two-argument usual deallocation function. |
| return elementType.isDestructedType(); |
| } |
| |
| bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) { |
| // Microsoft seems to completely ignore the possibility of a |
| // two-argument usual deallocation function. |
| return expr->getAllocatedType().isDestructedType(); |
| } |
| |
| CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) { |
| // The array cookie is always a size_t; we then pad that out to the |
| // alignment of the element type. |
| ASTContext &Ctx = getContext(); |
| return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()), |
| Ctx.getTypeAlignInChars(type)); |
| } |
| |
| llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF, |
| llvm::Value *allocPtr, |
| CharUnits cookieSize) { |
| unsigned AS = allocPtr->getType()->getPointerAddressSpace(); |
| llvm::Value *numElementsPtr = |
| CGF.Builder.CreateBitCast(allocPtr, CGF.SizeTy->getPointerTo(AS)); |
| return CGF.Builder.CreateLoad(numElementsPtr); |
| } |
| |
| llvm::Value* MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF, |
| llvm::Value *newPtr, |
| llvm::Value *numElements, |
| const CXXNewExpr *expr, |
| QualType elementType) { |
| assert(requiresArrayCookie(expr)); |
| |
| // The size of the cookie. |
| CharUnits cookieSize = getArrayCookieSizeImpl(elementType); |
| |
| // Compute an offset to the cookie. |
| llvm::Value *cookiePtr = newPtr; |
| |
| // Write the number of elements into the appropriate slot. |
| unsigned AS = newPtr->getType()->getPointerAddressSpace(); |
| llvm::Value *numElementsPtr |
| = CGF.Builder.CreateBitCast(cookiePtr, CGF.SizeTy->getPointerTo(AS)); |
| CGF.Builder.CreateStore(numElements, numElementsPtr); |
| |
| // Finally, compute a pointer to the actual data buffer by skipping |
| // over the cookie completely. |
| return CGF.Builder.CreateConstInBoundsGEP1_64(newPtr, |
| cookieSize.getQuantity()); |
| } |
| |
| void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D, |
| llvm::GlobalVariable *DeclPtr, |
| bool PerformInit) { |
| // FIXME: this code was only tested for global initialization. |
| // Not sure whether we want thread-safe static local variables as VS |
| // doesn't make them thread-safe. |
| |
| if (D.getTLSKind()) |
| CGM.ErrorUnsupported(&D, "dynamic TLS initialization"); |
| |
| // Emit the initializer and add a global destructor if appropriate. |
| CGF.EmitCXXGlobalVarDeclInit(D, DeclPtr, PerformInit); |
| } |
| |
| // Member pointer helpers. |
| static bool hasVBPtrOffsetField(MSInheritanceModel Inheritance) { |
| return Inheritance == MSIM_Unspecified; |
| } |
| |
| static bool hasOnlyOneField(MSInheritanceModel Inheritance) { |
| return Inheritance <= MSIM_SinglePolymorphic; |
| } |
| |
| // Only member pointers to functions need a this adjustment, since it can be |
| // combined with the field offset for data pointers. |
| static bool hasNonVirtualBaseAdjustmentField(bool IsMemberFunction, |
| MSInheritanceModel Inheritance) { |
| return (IsMemberFunction && Inheritance >= MSIM_Multiple); |
| } |
| |
| static bool hasVirtualBaseAdjustmentField(MSInheritanceModel Inheritance) { |
| return Inheritance >= MSIM_Virtual; |
| } |
| |
| // Use zero for the field offset of a null data member pointer if we can |
| // guarantee that zero is not a valid field offset, or if the member pointer has |
| // multiple fields. Polymorphic classes have a vfptr at offset zero, so we can |
| // use zero for null. If there are multiple fields, we can use zero even if it |
| // is a valid field offset because null-ness testing will check the other |
| // fields. |
| static bool nullFieldOffsetIsZero(MSInheritanceModel Inheritance) { |
| return Inheritance != MSIM_Multiple && Inheritance != MSIM_Single; |
| } |
| |
| bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) { |
| // Null-ness for function memptrs only depends on the first field, which is |
| // the function pointer. The rest don't matter, so we can zero initialize. |
| if (MPT->isMemberFunctionPointer()) |
| return true; |
| |
| // The virtual base adjustment field is always -1 for null, so if we have one |
| // we can't zero initialize. The field offset is sometimes also -1 if 0 is a |
| // valid field offset. |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| return (!hasVirtualBaseAdjustmentField(Inheritance) && |
| nullFieldOffsetIsZero(Inheritance)); |
| } |
| |
| llvm::Type * |
| MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) { |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| llvm::SmallVector<llvm::Type *, 4> fields; |
| if (MPT->isMemberFunctionPointer()) |
| fields.push_back(CGM.VoidPtrTy); // FunctionPointerOrVirtualThunk |
| else |
| fields.push_back(CGM.IntTy); // FieldOffset |
| |
| if (hasNonVirtualBaseAdjustmentField(MPT->isMemberFunctionPointer(), |
| Inheritance)) |
| fields.push_back(CGM.IntTy); |
| if (hasVBPtrOffsetField(Inheritance)) |
| fields.push_back(CGM.IntTy); |
| if (hasVirtualBaseAdjustmentField(Inheritance)) |
| fields.push_back(CGM.IntTy); // VirtualBaseAdjustmentOffset |
| |
| if (fields.size() == 1) |
| return fields[0]; |
| return llvm::StructType::get(CGM.getLLVMContext(), fields); |
| } |
| |
| void MicrosoftCXXABI:: |
| GetNullMemberPointerFields(const MemberPointerType *MPT, |
| llvm::SmallVectorImpl<llvm::Constant *> &fields) { |
| assert(fields.empty()); |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| if (MPT->isMemberFunctionPointer()) { |
| // FunctionPointerOrVirtualThunk |
| fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy)); |
| } else { |
| if (nullFieldOffsetIsZero(Inheritance)) |
| fields.push_back(getZeroInt()); // FieldOffset |
| else |
| fields.push_back(getAllOnesInt()); // FieldOffset |
| } |
| |
| if (hasNonVirtualBaseAdjustmentField(MPT->isMemberFunctionPointer(), |
| Inheritance)) |
| fields.push_back(getZeroInt()); |
| if (hasVBPtrOffsetField(Inheritance)) |
| fields.push_back(getZeroInt()); |
| if (hasVirtualBaseAdjustmentField(Inheritance)) |
| fields.push_back(getAllOnesInt()); |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) { |
| llvm::SmallVector<llvm::Constant *, 4> fields; |
| GetNullMemberPointerFields(MPT, fields); |
| if (fields.size() == 1) |
| return fields[0]; |
| llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields); |
| assert(Res->getType() == ConvertMemberPointerType(MPT)); |
| return Res; |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField, |
| bool IsMemberFunction, |
| const CXXRecordDecl *RD) |
| { |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| |
| // Single inheritance class member pointer are represented as scalars instead |
| // of aggregates. |
| if (hasOnlyOneField(Inheritance)) |
| return FirstField; |
| |
| llvm::SmallVector<llvm::Constant *, 4> fields; |
| fields.push_back(FirstField); |
| |
| if (hasNonVirtualBaseAdjustmentField(IsMemberFunction, Inheritance)) |
| fields.push_back(getZeroInt()); |
| |
| if (hasVBPtrOffsetField(Inheritance)) { |
| int64_t VBPtrOffset = |
| getContext().getASTRecordLayout(RD).getVBPtrOffset().getQuantity(); |
| if (VBPtrOffset == -1) |
| VBPtrOffset = 0; |
| fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset)); |
| } |
| |
| // The rest of the fields are adjusted by conversions to a more derived class. |
| if (hasVirtualBaseAdjustmentField(Inheritance)) |
| fields.push_back(getZeroInt()); |
| |
| return llvm::ConstantStruct::getAnon(fields); |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT, |
| CharUnits offset) { |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| llvm::Constant *FirstField = |
| llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity()); |
| return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD); |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::EmitMemberPointer(const CXXMethodDecl *MD) { |
| assert(MD->isInstance() && "Member function must not be static!"); |
| MD = MD->getCanonicalDecl(); |
| const CXXRecordDecl *RD = MD->getParent(); |
| CodeGenTypes &Types = CGM.getTypes(); |
| |
| llvm::Constant *FirstField; |
| if (MD->isVirtual()) { |
| // FIXME: We have to instantiate a thunk that loads the vftable and jumps to |
| // the right offset. |
| FirstField = llvm::Constant::getNullValue(CGM.VoidPtrTy); |
| } else { |
| const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); |
| llvm::Type *Ty; |
| // Check whether the function has a computable LLVM signature. |
| if (Types.isFuncTypeConvertible(FPT)) { |
| // The function has a computable LLVM signature; use the correct type. |
| Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD)); |
| } else { |
| // Use an arbitrary non-function type to tell GetAddrOfFunction that the |
| // function type is incomplete. |
| Ty = CGM.PtrDiffTy; |
| } |
| FirstField = CGM.GetAddrOfFunction(MD, Ty); |
| FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy); |
| } |
| |
| // The rest of the fields are common with data member pointers. |
| return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD); |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::EmitMemberPointer(const APValue &MP, QualType MPT) { |
| // FIXME PR15875: Implement member pointer conversions for Constants. |
| const CXXRecordDecl *RD = MPT->castAs<MemberPointerType>()->getClass()->getAsCXXRecordDecl(); |
| return EmitFullMemberPointer(llvm::Constant::getNullValue(CGM.VoidPtrTy), |
| /*IsMemberFunction=*/true, RD); |
| } |
| |
| /// Member pointers are the same if they're either bitwise identical *or* both |
| /// null. Null-ness for function members is determined by the first field, |
| /// while for data member pointers we must compare all fields. |
| llvm::Value * |
| MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF, |
| llvm::Value *L, |
| llvm::Value *R, |
| const MemberPointerType *MPT, |
| bool Inequality) { |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| // Handle != comparisons by switching the sense of all boolean operations. |
| llvm::ICmpInst::Predicate Eq; |
| llvm::Instruction::BinaryOps And, Or; |
| if (Inequality) { |
| Eq = llvm::ICmpInst::ICMP_NE; |
| And = llvm::Instruction::Or; |
| Or = llvm::Instruction::And; |
| } else { |
| Eq = llvm::ICmpInst::ICMP_EQ; |
| And = llvm::Instruction::And; |
| Or = llvm::Instruction::Or; |
| } |
| |
| // If this is a single field member pointer (single inheritance), this is a |
| // single icmp. |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| if (hasOnlyOneField(Inheritance)) |
| return Builder.CreateICmp(Eq, L, R); |
| |
| // Compare the first field. |
| llvm::Value *L0 = Builder.CreateExtractValue(L, 0, "lhs.0"); |
| llvm::Value *R0 = Builder.CreateExtractValue(R, 0, "rhs.0"); |
| llvm::Value *Cmp0 = Builder.CreateICmp(Eq, L0, R0, "memptr.cmp.first"); |
| |
| // Compare everything other than the first field. |
| llvm::Value *Res = 0; |
| llvm::StructType *LType = cast<llvm::StructType>(L->getType()); |
| for (unsigned I = 1, E = LType->getNumElements(); I != E; ++I) { |
| llvm::Value *LF = Builder.CreateExtractValue(L, I); |
| llvm::Value *RF = Builder.CreateExtractValue(R, I); |
| llvm::Value *Cmp = Builder.CreateICmp(Eq, LF, RF, "memptr.cmp.rest"); |
| if (Res) |
| Res = Builder.CreateBinOp(And, Res, Cmp); |
| else |
| Res = Cmp; |
| } |
| |
| // Check if the first field is 0 if this is a function pointer. |
| if (MPT->isMemberFunctionPointer()) { |
| // (l1 == r1 && ...) || l0 == 0 |
| llvm::Value *Zero = llvm::Constant::getNullValue(L0->getType()); |
| llvm::Value *IsZero = Builder.CreateICmp(Eq, L0, Zero, "memptr.cmp.iszero"); |
| Res = Builder.CreateBinOp(Or, Res, IsZero); |
| } |
| |
| // Combine the comparison of the first field, which must always be true for |
| // this comparison to succeeed. |
| return Builder.CreateBinOp(And, Res, Cmp0, "memptr.cmp"); |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT) { |
| CGBuilderTy &Builder = CGF.Builder; |
| llvm::SmallVector<llvm::Constant *, 4> fields; |
| // We only need one field for member functions. |
| if (MPT->isMemberFunctionPointer()) |
| fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy)); |
| else |
| GetNullMemberPointerFields(MPT, fields); |
| assert(!fields.empty()); |
| llvm::Value *FirstField = MemPtr; |
| if (MemPtr->getType()->isStructTy()) |
| FirstField = Builder.CreateExtractValue(MemPtr, 0); |
| llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0"); |
| |
| // For function member pointers, we only need to test the function pointer |
| // field. The other fields if any can be garbage. |
| if (MPT->isMemberFunctionPointer()) |
| return Res; |
| |
| // Otherwise, emit a series of compares and combine the results. |
| for (int I = 1, E = fields.size(); I < E; ++I) { |
| llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I); |
| llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp"); |
| Res = Builder.CreateAnd(Res, Next, "memptr.tobool"); |
| } |
| return Res; |
| } |
| |
| // Returns an adjusted base cast to i8*, since we do more address arithmetic on |
| // it. |
| llvm::Value * |
| MicrosoftCXXABI::AdjustVirtualBase(CodeGenFunction &CGF, |
| const CXXRecordDecl *RD, llvm::Value *Base, |
| llvm::Value *VirtualBaseAdjustmentOffset, |
| llvm::Value *VBPtrOffset) { |
| CGBuilderTy &Builder = CGF.Builder; |
| Base = Builder.CreateBitCast(Base, CGM.Int8PtrTy); |
| llvm::BasicBlock *OriginalBB = 0; |
| llvm::BasicBlock *SkipAdjustBB = 0; |
| llvm::BasicBlock *VBaseAdjustBB = 0; |
| |
| // In the unspecified inheritance model, there might not be a vbtable at all, |
| // in which case we need to skip the virtual base lookup. If there is a |
| // vbtable, the first entry is a no-op entry that gives back the original |
| // base, so look for a virtual base adjustment offset of zero. |
| if (VBPtrOffset) { |
| OriginalBB = Builder.GetInsertBlock(); |
| VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust"); |
| SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust"); |
| llvm::Value *IsVirtual = |
| Builder.CreateICmpNE(VirtualBaseAdjustmentOffset, getZeroInt(), |
| "memptr.is_vbase"); |
| Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB); |
| CGF.EmitBlock(VBaseAdjustBB); |
| } |
| |
| // If we weren't given a dynamic vbptr offset, RD should be complete and we'll |
| // know the vbptr offset. |
| if (!VBPtrOffset) { |
| CharUnits offs = getContext().getASTRecordLayout(RD).getVBPtrOffset(); |
| VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity()); |
| } |
| // Load the vbtable pointer from the vbtable offset in the instance. |
| llvm::Value *VBPtr = |
| Builder.CreateInBoundsGEP(Base, VBPtrOffset, "memptr.vbptr"); |
| llvm::Value *VBTable = |
| Builder.CreateBitCast(VBPtr, CGM.Int8PtrTy->getPointerTo(0)); |
| VBTable = Builder.CreateLoad(VBTable, "memptr.vbtable"); |
| // Load an i32 offset from the vb-table. |
| llvm::Value *VBaseOffs = |
| Builder.CreateInBoundsGEP(VBTable, VirtualBaseAdjustmentOffset); |
| VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0)); |
| VBaseOffs = Builder.CreateLoad(VBaseOffs, "memptr.vbase_offs"); |
| // Add it to VBPtr. GEP will sign extend the i32 value for us. |
| llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs); |
| |
| // Merge control flow with the case where we didn't have to adjust. |
| if (VBaseAdjustBB) { |
| Builder.CreateBr(SkipAdjustBB); |
| CGF.EmitBlock(SkipAdjustBB); |
| llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base"); |
| Phi->addIncoming(Base, OriginalBB); |
| Phi->addIncoming(AdjustedBase, VBaseAdjustBB); |
| return Phi; |
| } |
| return AdjustedBase; |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::EmitMemberDataPointerAddress(CodeGenFunction &CGF, |
| llvm::Value *Base, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT) { |
| assert(MPT->isMemberDataPointer()); |
| unsigned AS = Base->getType()->getPointerAddressSpace(); |
| llvm::Type *PType = |
| CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS); |
| CGBuilderTy &Builder = CGF.Builder; |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| |
| // Extract the fields we need, regardless of model. We'll apply them if we |
| // have them. |
| llvm::Value *FieldOffset = MemPtr; |
| llvm::Value *VirtualBaseAdjustmentOffset = 0; |
| llvm::Value *VBPtrOffset = 0; |
| if (MemPtr->getType()->isStructTy()) { |
| // We need to extract values. |
| unsigned I = 0; |
| FieldOffset = Builder.CreateExtractValue(MemPtr, I++); |
| if (hasVBPtrOffsetField(Inheritance)) |
| VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++); |
| if (hasVirtualBaseAdjustmentField(Inheritance)) |
| VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++); |
| } |
| |
| if (VirtualBaseAdjustmentOffset) { |
| Base = AdjustVirtualBase(CGF, RD, Base, VirtualBaseAdjustmentOffset, |
| VBPtrOffset); |
| } |
| llvm::Value *Addr = |
| Builder.CreateInBoundsGEP(Base, FieldOffset, "memptr.offset"); |
| |
| // Cast the address to the appropriate pointer type, adopting the address |
| // space of the base pointer. |
| return Builder.CreateBitCast(Addr, PType); |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, |
| llvm::Value *&This, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT) { |
| assert(MPT->isMemberFunctionPointer()); |
| const FunctionProtoType *FPT = |
| MPT->getPointeeType()->castAs<FunctionProtoType>(); |
| const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl(); |
| llvm::FunctionType *FTy = |
| CGM.getTypes().GetFunctionType( |
| CGM.getTypes().arrangeCXXMethodType(RD, FPT)); |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| |
| // Extract the fields we need, regardless of model. We'll apply them if we |
| // have them. |
| llvm::Value *FunctionPointer = MemPtr; |
| llvm::Value *NonVirtualBaseAdjustment = NULL; |
| llvm::Value *VirtualBaseAdjustmentOffset = NULL; |
| llvm::Value *VBPtrOffset = NULL; |
| if (MemPtr->getType()->isStructTy()) { |
| // We need to extract values. |
| unsigned I = 0; |
| FunctionPointer = Builder.CreateExtractValue(MemPtr, I++); |
| if (hasNonVirtualBaseAdjustmentField(MPT, Inheritance)) |
| NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++); |
| if (hasVBPtrOffsetField(Inheritance)) |
| VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++); |
| if (hasVirtualBaseAdjustmentField(Inheritance)) |
| VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++); |
| } |
| |
| if (VirtualBaseAdjustmentOffset) { |
| This = AdjustVirtualBase(CGF, RD, This, VirtualBaseAdjustmentOffset, |
| VBPtrOffset); |
| } |
| |
| if (NonVirtualBaseAdjustment) { |
| // Apply the adjustment and cast back to the original struct type. |
| llvm::Value *Ptr = Builder.CreateBitCast(This, Builder.getInt8PtrTy()); |
| Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment); |
| This = Builder.CreateBitCast(Ptr, This->getType(), "this.adjusted"); |
| } |
| |
| return Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo()); |
| } |
| |
| CGCXXABI *clang::CodeGen::CreateMicrosoftCXXABI(CodeGenModule &CGM) { |
| return new MicrosoftCXXABI(CGM); |
| } |
| |
