| //===--- 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 "CGVTables.h" |
| #include "MicrosoftVBTables.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/VTableBuilder.h" |
| #include "llvm/ADT/StringSet.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| namespace { |
| |
| class MicrosoftCXXABI : public CGCXXABI { |
| public: |
| MicrosoftCXXABI(CodeGenModule &CGM) : CGCXXABI(CGM) {} |
| |
| bool HasThisReturn(GlobalDecl GD) const; |
| |
| 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() || RD->hasNonTrivialDestructor()) |
| 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"; } |
| |
| bool isInlineInitializedStaticDataMemberLinkOnce() { return true; } |
| |
| llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF, |
| llvm::Value *ptr, |
| QualType type); |
| |
| llvm::Value *GetVirtualBaseClassOffset(CodeGenFunction &CGF, |
| llvm::Value *This, |
| const CXXRecordDecl *ClassDecl, |
| const CXXRecordDecl *BaseClassDecl); |
| |
| void BuildConstructorSignature(const CXXConstructorDecl *Ctor, |
| CXXCtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys); |
| |
| llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF, |
| const CXXRecordDecl *RD); |
| |
| void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF, |
| const CXXRecordDecl *RD); |
| |
| void EmitCXXConstructors(const CXXConstructorDecl *D); |
| |
| // Background on MSVC destructors |
| // ============================== |
| // |
| // Both Itanium and MSVC ABIs have destructor variants. The variant names |
| // roughly correspond in the following way: |
| // Itanium Microsoft |
| // Base -> no name, just ~Class |
| // Complete -> vbase destructor |
| // Deleting -> scalar deleting destructor |
| // vector deleting destructor |
| // |
| // The base and complete destructors are the same as in Itanium, although the |
| // complete destructor does not accept a VTT parameter when there are virtual |
| // bases. A separate mechanism involving vtordisps is used to ensure that |
| // virtual methods of destroyed subobjects are not called. |
| // |
| // The deleting destructors accept an i32 bitfield as a second parameter. Bit |
| // 1 indicates if the memory should be deleted. Bit 2 indicates if the this |
| // pointer points to an array. The scalar deleting destructor assumes that |
| // bit 2 is zero, and therefore does not contain a loop. |
| // |
| // For virtual destructors, only one entry is reserved in the vftable, and it |
| // always points to the vector deleting destructor. The vector deleting |
| // destructor is the most general, so it can be used to destroy objects in |
| // place, delete single heap objects, or delete arrays. |
| // |
| // A TU defining a non-inline destructor is only guaranteed to emit a base |
| // destructor, and all of the other variants are emitted on an as-needed basis |
| // in COMDATs. Because a non-base destructor can be emitted in a TU that |
| // lacks a definition for the destructor, non-base destructors must always |
| // delegate to or alias the base destructor. |
| |
| void BuildDestructorSignature(const CXXDestructorDecl *Dtor, |
| CXXDtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys); |
| |
| /// Non-base dtors should be emitted as delegating thunks in this ABI. |
| bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor, |
| CXXDtorType DT) const { |
| return DT != Dtor_Base; |
| } |
| |
| void EmitCXXDestructors(const CXXDestructorDecl *D); |
| |
| const CXXRecordDecl *getThisArgumentTypeForMethod(const CXXMethodDecl *MD) { |
| MD = MD->getCanonicalDecl(); |
| if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) { |
| MicrosoftVTableContext::MethodVFTableLocation ML = |
| CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD); |
| // The vbases might be ordered differently in the final overrider object |
| // and the complete object, so the "this" argument may sometimes point to |
| // memory that has no particular type (e.g. past the complete object). |
| // In this case, we just use a generic pointer type. |
| // FIXME: might want to have a more precise type in the non-virtual |
| // multiple inheritance case. |
| if (ML.VBase || !ML.VFPtrOffset.isZero()) |
| return 0; |
| } |
| return MD->getParent(); |
| } |
| |
| llvm::Value *adjustThisArgumentForVirtualCall(CodeGenFunction &CGF, |
| GlobalDecl GD, |
| llvm::Value *This); |
| |
| void BuildInstanceFunctionParams(CodeGenFunction &CGF, |
| QualType &ResTy, |
| FunctionArgList &Params); |
| |
| llvm::Value *adjustThisParameterInVirtualFunctionPrologue( |
| CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This); |
| |
| void EmitInstanceFunctionProlog(CodeGenFunction &CGF); |
| |
| void 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); |
| |
| void emitVTableDefinitions(CodeGenVTables &CGVT, const CXXRecordDecl *RD); |
| |
| llvm::Value *getVTableAddressPointInStructor( |
| CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, |
| BaseSubobject Base, const CXXRecordDecl *NearestVBase, |
| bool &NeedsVirtualOffset); |
| |
| llvm::Constant * |
| getVTableAddressPointForConstExpr(BaseSubobject Base, |
| const CXXRecordDecl *VTableClass); |
| |
| llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD, |
| CharUnits VPtrOffset); |
| |
| llvm::Value *getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD, |
| llvm::Value *This, llvm::Type *Ty); |
| |
| void EmitVirtualDestructorCall(CodeGenFunction &CGF, |
| const CXXDestructorDecl *Dtor, |
| CXXDtorType DtorType, SourceLocation CallLoc, |
| llvm::Value *This); |
| |
| void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD, |
| CallArgList &CallArgs) { |
| assert(GD.getDtorType() == Dtor_Deleting && |
| "Only deleting destructor thunks are available in this ABI"); |
| CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)), |
| CGM.getContext().IntTy); |
| } |
| |
| void emitVirtualInheritanceTables(const CXXRecordDecl *RD); |
| |
| void setThunkLinkage(llvm::Function *Thunk, bool ForVTable) { |
| Thunk->setLinkage(llvm::GlobalValue::WeakAnyLinkage); |
| } |
| |
| llvm::Value *performThisAdjustment(CodeGenFunction &CGF, llvm::Value *This, |
| const ThisAdjustment &TA); |
| |
| llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, llvm::Value *Ret, |
| const ReturnAdjustment &RA); |
| |
| 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); |
| |
| private: |
| MicrosoftMangleContext &getMangleContext() { |
| return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext()); |
| } |
| |
| llvm::Constant *getZeroInt() { |
| return llvm::ConstantInt::get(CGM.IntTy, 0); |
| } |
| |
| llvm::Constant *getAllOnesInt() { |
| return llvm::Constant::getAllOnesValue(CGM.IntTy); |
| } |
| |
| llvm::Constant *getConstantOrZeroInt(llvm::Constant *C) { |
| return C ? C : getZeroInt(); |
| } |
| |
| llvm::Value *getValueOrZeroInt(llvm::Value *C) { |
| return C ? C : getZeroInt(); |
| } |
| |
| void |
| GetNullMemberPointerFields(const MemberPointerType *MPT, |
| llvm::SmallVectorImpl<llvm::Constant *> &fields); |
| |
| /// \brief Finds the offset from the base of RD to the vbptr it uses, even if |
| /// it is reusing a vbptr from a non-virtual base. RD must have morally |
| /// virtual bases. |
| CharUnits GetVBPtrOffsetFromBases(const CXXRecordDecl *RD); |
| |
| /// \brief Shared code for virtual base adjustment. Returns the offset from |
| /// the vbptr to the virtual base. Optionally returns the address of the |
| /// vbptr itself. |
| llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF, |
| llvm::Value *Base, |
| llvm::Value *VBPtrOffset, |
| llvm::Value *VBTableOffset, |
| llvm::Value **VBPtr = 0); |
| |
| llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF, |
| llvm::Value *Base, |
| int32_t VBPtrOffset, |
| int32_t VBTableOffset, |
| llvm::Value **VBPtr = 0) { |
| llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), |
| *VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset); |
| return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr); |
| } |
| |
| /// \brief Performs a full virtual base adjustment. Used to dereference |
| /// pointers to members of virtual bases. |
| 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, |
| CharUnits NonVirtualBaseAdjustment); |
| |
| llvm::Constant *BuildMemberPointer(const CXXRecordDecl *RD, |
| const CXXMethodDecl *MD, |
| CharUnits NonVirtualBaseAdjustment); |
| |
| bool MemberPointerConstantIsNull(const MemberPointerType *MPT, |
| llvm::Constant *MP); |
| |
| /// \brief - Initialize all vbptrs of 'this' with RD as the complete type. |
| void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD); |
| |
| /// \brief Caching wrapper around VBTableBuilder::enumerateVBTables(). |
| const VBTableVector &EnumerateVBTables(const CXXRecordDecl *RD); |
| |
| /// \brief Generate a thunk for calling a virtual member function MD. |
| llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD, |
| StringRef ThunkName); |
| |
| 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 *EmitMemberPointerConversion(CodeGenFunction &CGF, |
| const CastExpr *E, |
| llvm::Value *Src); |
| |
| virtual llvm::Constant *EmitMemberPointerConversion(const CastExpr *E, |
| llvm::Constant *Src); |
| |
| virtual llvm::Value * |
| EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, |
| llvm::Value *&This, |
| llvm::Value *MemPtr, |
| const MemberPointerType *MPT); |
| |
| private: |
| typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy; |
| typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VFTablesMapTy; |
| /// \brief All the vftables that have been referenced. |
| VFTablesMapTy VFTablesMap; |
| |
| /// \brief This set holds the record decls we've deferred vtable emission for. |
| llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables; |
| |
| |
| /// \brief All the vbtables which have been referenced. |
| llvm::DenseMap<const CXXRecordDecl *, VBTableVector> VBTablesMap; |
| |
| /// Info on the global variable used to guard initialization of static locals. |
| /// The BitIndex field is only used for externally invisible declarations. |
| struct GuardInfo { |
| GuardInfo() : Guard(0), BitIndex(0) {} |
| llvm::GlobalVariable *Guard; |
| unsigned BitIndex; |
| }; |
| |
| /// Map from DeclContext to the current guard variable. We assume that the |
| /// AST is visited in source code order. |
| llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap; |
| }; |
| |
| } |
| |
| llvm::Value *MicrosoftCXXABI::adjustToCompleteObject(CodeGenFunction &CGF, |
| llvm::Value *ptr, |
| QualType type) { |
| // FIXME: implement |
| return ptr; |
| } |
| |
| /// \brief Finds the first non-virtual base of RD that has virtual bases. If RD |
| /// doesn't have a vbptr, it will reuse the vbptr of the returned class. |
| static const CXXRecordDecl *FindFirstNVBaseWithVBases(const CXXRecordDecl *RD) { |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| const CXXRecordDecl *Base = I->getType()->getAsCXXRecordDecl(); |
| if (!I->isVirtual() && Base->getNumVBases() > 0) |
| return Base; |
| } |
| llvm_unreachable("RD must have an nv base with vbases"); |
| } |
| |
| CharUnits MicrosoftCXXABI::GetVBPtrOffsetFromBases(const CXXRecordDecl *RD) { |
| assert(RD->getNumVBases()); |
| CharUnits Total = CharUnits::Zero(); |
| while (RD) { |
| const ASTRecordLayout &RDLayout = getContext().getASTRecordLayout(RD); |
| CharUnits VBPtrOffset = RDLayout.getVBPtrOffset(); |
| // -1 is the sentinel for no vbptr. |
| if (VBPtrOffset != CharUnits::fromQuantity(-1)) { |
| Total += VBPtrOffset; |
| break; |
| } |
| RD = FindFirstNVBaseWithVBases(RD); |
| Total += RDLayout.getBaseClassOffset(RD); |
| } |
| return Total; |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::GetVirtualBaseClassOffset(CodeGenFunction &CGF, |
| llvm::Value *This, |
| const CXXRecordDecl *ClassDecl, |
| const CXXRecordDecl *BaseClassDecl) { |
| int64_t VBPtrChars = GetVBPtrOffsetFromBases(ClassDecl).getQuantity(); |
| llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars); |
| CharUnits IntSize = getContext().getTypeSizeInChars(getContext().IntTy); |
| CharUnits VBTableChars = |
| IntSize * |
| CGM.getMicrosoftVTableContext().getVBTableIndex(ClassDecl, BaseClassDecl); |
| llvm::Value *VBTableOffset = |
| llvm::ConstantInt::get(CGM.IntTy, VBTableChars.getQuantity()); |
| |
| llvm::Value *VBPtrToNewBase = |
| GetVBaseOffsetFromVBPtr(CGF, This, VBPtrOffset, VBTableOffset); |
| VBPtrToNewBase = |
| CGF.Builder.CreateSExtOrBitCast(VBPtrToNewBase, CGM.PtrDiffTy); |
| return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase); |
| } |
| |
| bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const { |
| return isa<CXXConstructorDecl>(GD.getDecl()); |
| } |
| |
| void MicrosoftCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor, |
| CXXCtorType Type, |
| CanQualType &ResTy, |
| SmallVectorImpl<CanQualType> &ArgTys) { |
| // 'this' parameter and 'this' return are already in place |
| |
| 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, |
| const CXXRecordDecl *RD) { |
| 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); |
| |
| // Fill in the vbtable pointers here. |
| EmitVBPtrStores(CGF, RD); |
| |
| // CGF will put the base ctor calls in this basic block for us later. |
| |
| return SkipVbaseCtorsBB; |
| } |
| |
| void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers( |
| CodeGenFunction &CGF, const CXXRecordDecl *RD) { |
| // In most cases, an override for a vbase virtual method can adjust |
| // the "this" parameter by applying a constant offset. |
| // However, this is not enough while a constructor or a destructor of some |
| // class X is being executed if all the following conditions are met: |
| // - X has virtual bases, (1) |
| // - X overrides a virtual method M of a vbase Y, (2) |
| // - X itself is a vbase of the most derived class. |
| // |
| // If (1) and (2) are true, the vtorDisp for vbase Y is a hidden member of X |
| // which holds the extra amount of "this" adjustment we must do when we use |
| // the X vftables (i.e. during X ctor or dtor). |
| // Outside the ctors and dtors, the values of vtorDisps are zero. |
| |
| const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); |
| typedef ASTRecordLayout::VBaseOffsetsMapTy VBOffsets; |
| const VBOffsets &VBaseMap = Layout.getVBaseOffsetsMap(); |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| unsigned AS = |
| cast<llvm::PointerType>(getThisValue(CGF)->getType())->getAddressSpace(); |
| llvm::Value *Int8This = 0; // Initialize lazily. |
| |
| for (VBOffsets::const_iterator I = VBaseMap.begin(), E = VBaseMap.end(); |
| I != E; ++I) { |
| if (!I->second.hasVtorDisp()) |
| continue; |
| |
| llvm::Value *VBaseOffset = |
| GetVirtualBaseClassOffset(CGF, getThisValue(CGF), RD, I->first); |
| // FIXME: it doesn't look right that we SExt in GetVirtualBaseClassOffset() |
| // just to Trunc back immediately. |
| VBaseOffset = Builder.CreateTruncOrBitCast(VBaseOffset, CGF.Int32Ty); |
| uint64_t ConstantVBaseOffset = |
| Layout.getVBaseClassOffset(I->first).getQuantity(); |
| |
| // vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase). |
| llvm::Value *VtorDispValue = Builder.CreateSub( |
| VBaseOffset, llvm::ConstantInt::get(CGM.Int32Ty, ConstantVBaseOffset), |
| "vtordisp.value"); |
| |
| if (!Int8This) |
| Int8This = Builder.CreateBitCast(getThisValue(CGF), |
| CGF.Int8Ty->getPointerTo(AS)); |
| llvm::Value *VtorDispPtr = Builder.CreateInBoundsGEP(Int8This, VBaseOffset); |
| // vtorDisp is always the 32-bits before the vbase in the class layout. |
| VtorDispPtr = Builder.CreateConstGEP1_32(VtorDispPtr, -4); |
| VtorDispPtr = Builder.CreateBitCast( |
| VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr"); |
| |
| Builder.CreateStore(VtorDispValue, VtorDispPtr); |
| } |
| } |
| |
| void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) { |
| // There's only one constructor type in this ABI. |
| CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete)); |
| } |
| |
| void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF, |
| const CXXRecordDecl *RD) { |
| llvm::Value *ThisInt8Ptr = |
| CGF.Builder.CreateBitCast(getThisValue(CGF), CGM.Int8PtrTy, "this.int8"); |
| |
| const VBTableVector &VBTables = EnumerateVBTables(RD); |
| for (VBTableVector::const_iterator I = VBTables.begin(), E = VBTables.end(); |
| I != E; ++I) { |
| const ASTRecordLayout &SubobjectLayout = |
| CGM.getContext().getASTRecordLayout(I->VBPtrSubobject.getBase()); |
| uint64_t Offs = (I->VBPtrSubobject.getBaseOffset() + |
| SubobjectLayout.getVBPtrOffset()).getQuantity(); |
| llvm::Value *VBPtr = |
| CGF.Builder.CreateConstInBoundsGEP1_64(ThisInt8Ptr, Offs); |
| VBPtr = CGF.Builder.CreateBitCast(VBPtr, I->GV->getType()->getPointerTo(0), |
| "vbptr." + I->ReusingBase->getName()); |
| CGF.Builder.CreateStore(I->GV, VBPtr); |
| } |
| } |
| |
| 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 int parameter. |
| ArgTys.push_back(CGM.getContext().IntTy); |
| } |
| } |
| |
| void MicrosoftCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) { |
| // The TU defining a dtor is only guaranteed to emit a base destructor. All |
| // other destructor variants are delegating thunks. |
| CGM.EmitGlobal(GlobalDecl(D, Dtor_Base)); |
| } |
| |
| llvm::Value *MicrosoftCXXABI::adjustThisArgumentForVirtualCall( |
| CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) { |
| GD = GD.getCanonicalDecl(); |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| // FIXME: consider splitting the vdtor vs regular method code into two |
| // functions. |
| |
| GlobalDecl LookupGD = GD; |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) { |
| // Complete dtors take a pointer to the complete object, |
| // thus don't need adjustment. |
| if (GD.getDtorType() == Dtor_Complete) |
| return This; |
| |
| // There's only Dtor_Deleting in vftable but it shares the this adjustment |
| // with the base one, so look up the deleting one instead. |
| LookupGD = GlobalDecl(DD, Dtor_Deleting); |
| } |
| MicrosoftVTableContext::MethodVFTableLocation ML = |
| CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD); |
| |
| unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace(); |
| llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS); |
| CharUnits StaticOffset = ML.VFPtrOffset; |
| if (ML.VBase) { |
| bool AvoidVirtualOffset = false; |
| if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base) { |
| // A base destructor can only be called from a complete destructor of the |
| // same record type or another destructor of a more derived type; |
| // or a constructor of the same record type if an exception is thrown. |
| assert(isa<CXXDestructorDecl>(CGF.CurGD.getDecl()) || |
| isa<CXXConstructorDecl>(CGF.CurGD.getDecl())); |
| const CXXRecordDecl *CurRD = |
| cast<CXXMethodDecl>(CGF.CurGD.getDecl())->getParent(); |
| |
| if (MD->getParent() == CurRD) { |
| if (isa<CXXDestructorDecl>(CGF.CurGD.getDecl())) |
| assert(CGF.CurGD.getDtorType() == Dtor_Complete); |
| if (isa<CXXConstructorDecl>(CGF.CurGD.getDecl())) |
| assert(CGF.CurGD.getCtorType() == Ctor_Complete); |
| // We're calling the main base dtor from a complete structor, |
| // so we know the "this" offset statically. |
| AvoidVirtualOffset = true; |
| } else { |
| // Let's see if we try to call a destructor of a non-virtual base. |
| for (CXXRecordDecl::base_class_const_iterator I = CurRD->bases_begin(), |
| E = CurRD->bases_end(); I != E; ++I) { |
| if (I->getType()->getAsCXXRecordDecl() != MD->getParent()) |
| continue; |
| // If we call a base destructor for a non-virtual base, we statically |
| // know where it expects the vfptr and "this" to be. |
| // The total offset should reflect the adjustment done by |
| // adjustThisParameterInVirtualFunctionPrologue(). |
| AvoidVirtualOffset = true; |
| break; |
| } |
| } |
| } |
| |
| if (AvoidVirtualOffset) { |
| const ASTRecordLayout &Layout = |
| CGF.getContext().getASTRecordLayout(MD->getParent()); |
| StaticOffset += Layout.getVBaseClassOffset(ML.VBase); |
| } else { |
| This = CGF.Builder.CreateBitCast(This, charPtrTy); |
| llvm::Value *VBaseOffset = |
| GetVirtualBaseClassOffset(CGF, This, MD->getParent(), ML.VBase); |
| This = CGF.Builder.CreateInBoundsGEP(This, VBaseOffset); |
| } |
| } |
| if (!StaticOffset.isZero()) { |
| assert(StaticOffset.isPositive()); |
| This = CGF.Builder.CreateBitCast(This, charPtrTy); |
| if (ML.VBase) { |
| // Non-virtual adjustment might result in a pointer outside the allocated |
| // object, e.g. if the final overrider class is laid out after the virtual |
| // base that declares a method in the most derived class. |
| // FIXME: Update the code that emits this adjustment in thunks prologues. |
| This = CGF.Builder.CreateConstGEP1_32(This, StaticOffset.getQuantity()); |
| } else { |
| This = CGF.Builder.CreateConstInBoundsGEP1_32(This, |
| StaticOffset.getQuantity()); |
| } |
| } |
| return This; |
| } |
| |
| 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); |
| |
| 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.IntTy); |
| Params.push_back(ShouldDelete); |
| getStructorImplicitParamDecl(CGF) = ShouldDelete; |
| } |
| } |
| |
| llvm::Value *MicrosoftCXXABI::adjustThisParameterInVirtualFunctionPrologue( |
| CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) { |
| GD = GD.getCanonicalDecl(); |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| |
| GlobalDecl LookupGD = GD; |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) { |
| // Complete destructors take a pointer to the complete object as a |
| // parameter, thus don't need this adjustment. |
| if (GD.getDtorType() == Dtor_Complete) |
| return This; |
| |
| // There's no Dtor_Base in vftable but it shares the this adjustment with |
| // the deleting one, so look it up instead. |
| LookupGD = GlobalDecl(DD, Dtor_Deleting); |
| } |
| |
| // In this ABI, every virtual function takes a pointer to one of the |
| // subobjects that first defines it as the 'this' parameter, rather than a |
| // pointer to ther final overrider subobject. Thus, we need to adjust it back |
| // to the final overrider subobject before use. |
| // See comments in the MicrosoftVFTableContext implementation for the details. |
| |
| MicrosoftVTableContext::MethodVFTableLocation ML = |
| CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD); |
| CharUnits Adjustment = ML.VFPtrOffset; |
| if (ML.VBase) { |
| const ASTRecordLayout &DerivedLayout = |
| CGF.getContext().getASTRecordLayout(MD->getParent()); |
| Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase); |
| } |
| |
| if (Adjustment.isZero()) |
| return This; |
| |
| unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace(); |
| llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS), |
| *thisTy = This->getType(); |
| |
| This = CGF.Builder.CreateBitCast(This, charPtrTy); |
| assert(Adjustment.isPositive()); |
| This = |
| CGF.Builder.CreateConstInBoundsGEP1_32(This, -Adjustment.getQuantity()); |
| return CGF.Builder.CreateBitCast(This, thisTy); |
| } |
| |
| void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) { |
| EmitThisParam(CGF); |
| |
| /// If this is a function that the ABI specifies returns 'this', initialize |
| /// the return slot to 'this' at the start of the function. |
| /// |
| /// Unlike the setting of return types, this is done within the ABI |
| /// implementation instead of by clients of CGCXXABI because: |
| /// 1) getThisValue is currently protected |
| /// 2) in theory, an ABI could implement 'this' returns some other way; |
| /// HasThisReturn only specifies a contract, not the implementation |
| if (HasThisReturn(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"); |
| } |
| } |
| |
| void 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); |
| } |
| |
| void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT, |
| const CXXRecordDecl *RD) { |
| MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext(); |
| MicrosoftVTableContext::VFPtrListTy VFPtrs = VFTContext.getVFPtrOffsets(RD); |
| llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD); |
| |
| for (MicrosoftVTableContext::VFPtrListTy::iterator I = VFPtrs.begin(), |
| E = VFPtrs.end(); I != E; ++I) { |
| llvm::GlobalVariable *VTable = getAddrOfVTable(RD, I->VFPtrFullOffset); |
| if (VTable->hasInitializer()) |
| continue; |
| |
| const VTableLayout &VTLayout = |
| VFTContext.getVFTableLayout(RD, I->VFPtrFullOffset); |
| llvm::Constant *Init = CGVT.CreateVTableInitializer( |
| RD, VTLayout.vtable_component_begin(), |
| VTLayout.getNumVTableComponents(), VTLayout.vtable_thunk_begin(), |
| VTLayout.getNumVTableThunks()); |
| VTable->setInitializer(Init); |
| |
| VTable->setLinkage(Linkage); |
| CGM.setTypeVisibility(VTable, RD, CodeGenModule::TVK_ForVTable); |
| } |
| } |
| |
| llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor( |
| CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base, |
| const CXXRecordDecl *NearestVBase, bool &NeedsVirtualOffset) { |
| NeedsVirtualOffset = (NearestVBase != 0); |
| |
| llvm::Value *VTableAddressPoint = |
| getAddrOfVTable(VTableClass, Base.getBaseOffset()); |
| if (!VTableAddressPoint) { |
| assert(Base.getBase()->getNumVBases() && |
| !CGM.getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr()); |
| } |
| return VTableAddressPoint; |
| } |
| |
| static void mangleVFTableName(MicrosoftMangleContext &MangleContext, |
| const CXXRecordDecl *RD, const VFPtrInfo &VFPtr, |
| SmallString<256> &Name) { |
| llvm::raw_svector_ostream Out(Name); |
| MangleContext.mangleCXXVFTable(RD, VFPtr.PathToMangle, Out); |
| } |
| |
| llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr( |
| BaseSubobject Base, const CXXRecordDecl *VTableClass) { |
| llvm::Constant *VTable = getAddrOfVTable(VTableClass, Base.getBaseOffset()); |
| assert(VTable && "Couldn't find a vftable for the given base?"); |
| return VTable; |
| } |
| |
| llvm::GlobalVariable *MicrosoftCXXABI::getAddrOfVTable(const CXXRecordDecl *RD, |
| CharUnits VPtrOffset) { |
| // getAddrOfVTable may return 0 if asked to get an address of a vtable which |
| // shouldn't be used in the given record type. We want to cache this result in |
| // VFTablesMap, thus a simple zero check is not sufficient. |
| VFTableIdTy ID(RD, VPtrOffset); |
| VFTablesMapTy::iterator I; |
| bool Inserted; |
| llvm::tie(I, Inserted) = VFTablesMap.insert( |
| std::make_pair(ID, static_cast<llvm::GlobalVariable *>(0))); |
| if (!Inserted) |
| return I->second; |
| |
| llvm::GlobalVariable *&VTable = I->second; |
| |
| MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext(); |
| const MicrosoftVTableContext::VFPtrListTy &VFPtrs = |
| VTContext.getVFPtrOffsets(RD); |
| |
| if (DeferredVFTables.insert(RD)) { |
| // We haven't processed this record type before. |
| // Queue up this v-table for possible deferred emission. |
| CGM.addDeferredVTable(RD); |
| |
| #ifndef NDEBUG |
| // Create all the vftables at once in order to make sure each vftable has |
| // a unique mangled name. |
| llvm::StringSet<> ObservedMangledNames; |
| for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) { |
| SmallString<256> Name; |
| mangleVFTableName(getMangleContext(), RD, VFPtrs[J], Name); |
| if (!ObservedMangledNames.insert(Name.str())) |
| llvm_unreachable("Already saw this mangling before?"); |
| } |
| #endif |
| } |
| |
| for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) { |
| if (VFPtrs[J].VFPtrFullOffset != VPtrOffset) |
| continue; |
| |
| llvm::ArrayType *ArrayType = llvm::ArrayType::get( |
| CGM.Int8PtrTy, |
| VTContext.getVFTableLayout(RD, VFPtrs[J].VFPtrFullOffset) |
| .getNumVTableComponents()); |
| |
| SmallString<256> Name; |
| mangleVFTableName(getMangleContext(), RD, VFPtrs[J], Name); |
| VTable = CGM.CreateOrReplaceCXXRuntimeVariable( |
| Name.str(), ArrayType, llvm::GlobalValue::ExternalLinkage); |
| VTable->setUnnamedAddr(true); |
| break; |
| } |
| |
| return VTable; |
| } |
| |
| llvm::Value *MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF, |
| GlobalDecl GD, |
| llvm::Value *This, |
| llvm::Type *Ty) { |
| GD = GD.getCanonicalDecl(); |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| Ty = Ty->getPointerTo()->getPointerTo(); |
| llvm::Value *VPtr = adjustThisArgumentForVirtualCall(CGF, GD, This); |
| llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty); |
| |
| MicrosoftVTableContext::MethodVFTableLocation ML = |
| CGM.getMicrosoftVTableContext().getMethodVFTableLocation(GD); |
| llvm::Value *VFuncPtr = |
| Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn"); |
| return Builder.CreateLoad(VFuncPtr); |
| } |
| |
| void MicrosoftCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF, |
| const CXXDestructorDecl *Dtor, |
| CXXDtorType DtorType, |
| SourceLocation CallLoc, |
| 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 int parameter. |
| GlobalDecl GD(Dtor, Dtor_Deleting); |
| const CGFunctionInfo *FInfo = |
| &CGM.getTypes().arrangeCXXDestructor(Dtor, Dtor_Deleting); |
| llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo); |
| llvm::Value *Callee = getVirtualFunctionPointer(CGF, GD, This, Ty); |
| |
| ASTContext &Context = CGF.getContext(); |
| llvm::Value *ImplicitParam = |
| llvm::ConstantInt::get(llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()), |
| DtorType == Dtor_Deleting); |
| |
| This = adjustThisArgumentForVirtualCall(CGF, GD, This); |
| CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValueSlot(), This, |
| ImplicitParam, Context.IntTy, 0, 0); |
| } |
| |
| const VBTableVector & |
| MicrosoftCXXABI::EnumerateVBTables(const CXXRecordDecl *RD) { |
| // At this layer, we can key the cache off of a single class, which is much |
| // easier than caching at the GlobalVariable layer. |
| llvm::DenseMap<const CXXRecordDecl*, VBTableVector>::iterator I; |
| bool added; |
| llvm::tie(I, added) = VBTablesMap.insert(std::make_pair(RD, VBTableVector())); |
| VBTableVector &VBTables = I->second; |
| if (!added) |
| return VBTables; |
| |
| VBTableBuilder(CGM, RD).enumerateVBTables(VBTables); |
| |
| return VBTables; |
| } |
| |
| llvm::Function * |
| MicrosoftCXXABI::EmitVirtualMemPtrThunk(const CXXMethodDecl *MD, |
| StringRef ThunkName) { |
| // If the thunk has been generated previously, just return it. |
| if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName)) |
| return cast<llvm::Function>(GV); |
| |
| // Create the llvm::Function. |
| const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeGlobalDeclaration(MD); |
| llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo); |
| llvm::Function *ThunkFn = |
| llvm::Function::Create(ThunkTy, llvm::Function::ExternalLinkage, |
| ThunkName.str(), &CGM.getModule()); |
| assert(ThunkFn->getName() == ThunkName && "name was uniqued!"); |
| |
| ThunkFn->setLinkage(MD->isExternallyVisible() |
| ? llvm::GlobalValue::LinkOnceODRLinkage |
| : llvm::GlobalValue::InternalLinkage); |
| |
| CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn); |
| CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn); |
| |
| // Start codegen. |
| CodeGenFunction CGF(CGM); |
| CGF.StartThunk(ThunkFn, MD, FnInfo); |
| |
| // Get to the Callee. |
| llvm::Value *This = CGF.LoadCXXThis(); |
| llvm::Value *Callee = getVirtualFunctionPointer(CGF, MD, This, ThunkTy); |
| |
| // Make the call and return the result. |
| CGF.EmitCallAndReturnForThunk(MD, Callee, 0); |
| |
| return ThunkFn; |
| } |
| |
| void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) { |
| const VBTableVector &VBTables = EnumerateVBTables(RD); |
| llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD); |
| |
| for (VBTableVector::const_iterator I = VBTables.begin(), E = VBTables.end(); |
| I != E; ++I) { |
| I->EmitVBTableDefinition(CGM, RD, Linkage); |
| } |
| } |
| |
| llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF, |
| llvm::Value *This, |
| const ThisAdjustment &TA) { |
| if (TA.isEmpty()) |
| return This; |
| |
| llvm::Value *V = CGF.Builder.CreateBitCast(This, CGF.Int8PtrTy); |
| |
| if (!TA.Virtual.isEmpty()) { |
| assert(TA.Virtual.Microsoft.VtordispOffset < 0); |
| // Adjust the this argument based on the vtordisp value. |
| llvm::Value *VtorDispPtr = |
| CGF.Builder.CreateConstGEP1_32(V, TA.Virtual.Microsoft.VtordispOffset); |
| VtorDispPtr = |
| CGF.Builder.CreateBitCast(VtorDispPtr, CGF.Int32Ty->getPointerTo()); |
| llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp"); |
| V = CGF.Builder.CreateGEP(V, CGF.Builder.CreateNeg(VtorDisp)); |
| |
| if (TA.Virtual.Microsoft.VBPtrOffset) { |
| // If the final overrider is defined in a virtual base other than the one |
| // that holds the vfptr, we have to use a vtordispex thunk which looks up |
| // the vbtable of the derived class. |
| assert(TA.Virtual.Microsoft.VBPtrOffset > 0); |
| assert(TA.Virtual.Microsoft.VBOffsetOffset >= 0); |
| llvm::Value *VBPtr; |
| llvm::Value *VBaseOffset = |
| GetVBaseOffsetFromVBPtr(CGF, V, -TA.Virtual.Microsoft.VBPtrOffset, |
| TA.Virtual.Microsoft.VBOffsetOffset, &VBPtr); |
| V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset); |
| } |
| } |
| |
| if (TA.NonVirtual) { |
| // Non-virtual adjustment might result in a pointer outside the allocated |
| // object, e.g. if the final overrider class is laid out after the virtual |
| // base that declares a method in the most derived class. |
| V = CGF.Builder.CreateConstGEP1_32(V, TA.NonVirtual); |
| } |
| |
| // Don't need to bitcast back, the call CodeGen will handle this. |
| return V; |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::performReturnAdjustment(CodeGenFunction &CGF, llvm::Value *Ret, |
| const ReturnAdjustment &RA) { |
| if (RA.isEmpty()) |
| return Ret; |
| |
| llvm::Value *V = CGF.Builder.CreateBitCast(Ret, CGF.Int8PtrTy); |
| |
| if (RA.Virtual.Microsoft.VBIndex) { |
| assert(RA.Virtual.Microsoft.VBIndex > 0); |
| int32_t IntSize = |
| getContext().getTypeSizeInChars(getContext().IntTy).getQuantity(); |
| llvm::Value *VBPtr; |
| llvm::Value *VBaseOffset = |
| GetVBaseOffsetFromVBPtr(CGF, V, RA.Virtual.Microsoft.VBPtrOffset, |
| IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr); |
| V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset); |
| } |
| |
| if (RA.NonVirtual) |
| V = CGF.Builder.CreateConstInBoundsGEP1_32(V, RA.NonVirtual); |
| |
| // Cast back to the original type. |
| return CGF.Builder.CreateBitCast(V, Ret->getType()); |
| } |
| |
| 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 *GV, |
| bool PerformInit) { |
| // MSVC always uses an i32 bitfield to guard initialization, which is *not* |
| // threadsafe. Since the user may be linking in inline functions compiled by |
| // cl.exe, there's no reason to provide a false sense of security by using |
| // critical sections here. |
| |
| if (D.getTLSKind()) |
| CGM.ErrorUnsupported(&D, "dynamic TLS initialization"); |
| |
| CGBuilderTy &Builder = CGF.Builder; |
| llvm::IntegerType *GuardTy = CGF.Int32Ty; |
| llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0); |
| |
| // Get the guard variable for this function if we have one already. |
| GuardInfo &GI = GuardVariableMap[D.getDeclContext()]; |
| |
| unsigned BitIndex; |
| if (D.isExternallyVisible()) { |
| // Externally visible variables have to be numbered in Sema to properly |
| // handle unreachable VarDecls. |
| BitIndex = getContext().getManglingNumber(&D); |
| assert(BitIndex > 0); |
| BitIndex--; |
| } else { |
| // Non-externally visible variables are numbered here in CodeGen. |
| BitIndex = GI.BitIndex++; |
| } |
| |
| if (BitIndex >= 32) { |
| if (D.isExternallyVisible()) |
| ErrorUnsupportedABI(CGF, "more than 32 guarded initializations"); |
| BitIndex %= 32; |
| GI.Guard = 0; |
| } |
| |
| // Lazily create the i32 bitfield for this function. |
| if (!GI.Guard) { |
| // Mangle the name for the guard. |
| SmallString<256> GuardName; |
| { |
| llvm::raw_svector_ostream Out(GuardName); |
| getMangleContext().mangleStaticGuardVariable(&D, Out); |
| Out.flush(); |
| } |
| |
| // Create the guard variable with a zero-initializer. Just absorb linkage |
| // and visibility from the guarded variable. |
| GI.Guard = new llvm::GlobalVariable(CGM.getModule(), GuardTy, false, |
| GV->getLinkage(), Zero, GuardName.str()); |
| GI.Guard->setVisibility(GV->getVisibility()); |
| } else { |
| assert(GI.Guard->getLinkage() == GV->getLinkage() && |
| "static local from the same function had different linkage"); |
| } |
| |
| // Pseudo code for the test: |
| // if (!(GuardVar & MyGuardBit)) { |
| // GuardVar |= MyGuardBit; |
| // ... initialize the object ...; |
| // } |
| |
| // Test our bit from the guard variable. |
| llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1U << BitIndex); |
| llvm::LoadInst *LI = Builder.CreateLoad(GI.Guard); |
| llvm::Value *IsInitialized = |
| Builder.CreateICmpNE(Builder.CreateAnd(LI, Bit), Zero); |
| llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init"); |
| llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end"); |
| Builder.CreateCondBr(IsInitialized, EndBlock, InitBlock); |
| |
| // Set our bit in the guard variable and emit the initializer and add a global |
| // destructor if appropriate. |
| CGF.EmitBlock(InitBlock); |
| Builder.CreateStore(Builder.CreateOr(LI, Bit), GI.Guard); |
| CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit); |
| Builder.CreateBr(EndBlock); |
| |
| // Continue. |
| CGF.EmitBlock(EndBlock); |
| } |
| |
| // Member pointer helpers. |
| static bool hasVBPtrOffsetField(MSInheritanceModel Inheritance) { |
| return Inheritance == MSIM_Unspecified; |
| } |
| |
| static bool hasOnlyOneField(bool IsMemberFunction, |
| MSInheritanceModel Inheritance) { |
| return Inheritance <= MSIM_SinglePolymorphic || |
| (!IsMemberFunction && Inheritance <= MSIM_MultiplePolymorphic); |
| } |
| |
| // 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, |
| CharUnits NonVirtualBaseAdjustment) |
| { |
| MSInheritanceModel Inheritance = RD->getMSInheritanceModel(); |
| |
| // Single inheritance class member pointer are represented as scalars instead |
| // of aggregates. |
| if (hasOnlyOneField(IsMemberFunction, Inheritance)) |
| return FirstField; |
| |
| llvm::SmallVector<llvm::Constant *, 4> fields; |
| fields.push_back(FirstField); |
| |
| if (hasNonVirtualBaseAdjustmentField(IsMemberFunction, Inheritance)) |
| fields.push_back(llvm::ConstantInt::get( |
| CGM.IntTy, NonVirtualBaseAdjustment.getQuantity())); |
| |
| if (hasVBPtrOffsetField(Inheritance)) { |
| CharUnits Offs = CharUnits::Zero(); |
| if (RD->getNumVBases()) |
| Offs = GetVBPtrOffsetFromBases(RD); |
| fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity())); |
| } |
| |
| // 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, |
| CharUnits::Zero()); |
| } |
| |
| llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const CXXMethodDecl *MD) { |
| return BuildMemberPointer(MD->getParent(), MD, CharUnits::Zero()); |
| } |
| |
| llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP, |
| QualType MPType) { |
| const MemberPointerType *MPT = MPType->castAs<MemberPointerType>(); |
| const ValueDecl *MPD = MP.getMemberPointerDecl(); |
| if (!MPD) |
| return EmitNullMemberPointer(MPT); |
| |
| CharUnits ThisAdjustment = getMemberPointerPathAdjustment(MP); |
| |
| // FIXME PR15713: Support virtual inheritance paths. |
| |
| if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) |
| return BuildMemberPointer(MPT->getClass()->getAsCXXRecordDecl(), |
| MD, ThisAdjustment); |
| |
| CharUnits FieldOffset = |
| getContext().toCharUnitsFromBits(getContext().getFieldOffset(MPD)); |
| return EmitMemberDataPointer(MPT, ThisAdjustment + FieldOffset); |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::BuildMemberPointer(const CXXRecordDecl *RD, |
| const CXXMethodDecl *MD, |
| CharUnits NonVirtualBaseAdjustment) { |
| assert(MD->isInstance() && "Member function must not be static!"); |
| MD = MD->getCanonicalDecl(); |
| CodeGenTypes &Types = CGM.getTypes(); |
| |
| llvm::Constant *FirstField; |
| if (!MD->isVirtual()) { |
| 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); |
| } else { |
| MicrosoftVTableContext::MethodVFTableLocation ML = |
| CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD); |
| if (MD->isVariadic()) { |
| CGM.ErrorUnsupported(MD, "pointer to variadic virtual member function"); |
| FirstField = llvm::Constant::getNullValue(CGM.VoidPtrTy); |
| } else if (!CGM.getTypes().isFuncTypeConvertible( |
| MD->getType()->castAs<FunctionType>())) { |
| CGM.ErrorUnsupported(MD, "pointer to virtual member function with " |
| "incomplete return or parameter type"); |
| FirstField = llvm::Constant::getNullValue(CGM.VoidPtrTy); |
| } else if (ML.VBase) { |
| CGM.ErrorUnsupported(MD, "pointer to virtual member function overriding " |
| "member function in virtual base class"); |
| FirstField = llvm::Constant::getNullValue(CGM.VoidPtrTy); |
| } else { |
| SmallString<256> ThunkName; |
| CharUnits PointerWidth = getContext().toCharUnitsFromBits( |
| getContext().getTargetInfo().getPointerWidth(0)); |
| uint64_t OffsetInVFTable = ML.Index * PointerWidth.getQuantity(); |
| llvm::raw_svector_ostream Out(ThunkName); |
| getMangleContext().mangleVirtualMemPtrThunk(MD, OffsetInVFTable, Out); |
| Out.flush(); |
| |
| llvm::Function *Thunk = EmitVirtualMemPtrThunk(MD, ThunkName.str()); |
| FirstField = llvm::ConstantExpr::getBitCast(Thunk, CGM.VoidPtrTy); |
| } |
| } |
| |
| // The rest of the fields are common with data member pointers. |
| return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD, |
| NonVirtualBaseAdjustment); |
| } |
| |
| /// 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(MPT->isMemberFunctionPointer(), 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; |
| } |
| |
| bool MicrosoftCXXABI::MemberPointerConstantIsNull(const MemberPointerType *MPT, |
| llvm::Constant *Val) { |
| // Function pointers are null if the pointer in the first field is null. |
| if (MPT->isMemberFunctionPointer()) { |
| llvm::Constant *FirstField = Val->getType()->isStructTy() ? |
| Val->getAggregateElement(0U) : Val; |
| return FirstField->isNullValue(); |
| } |
| |
| // If it's not a function pointer and it's zero initializable, we can easily |
| // check zero. |
| if (isZeroInitializable(MPT) && Val->isNullValue()) |
| return true; |
| |
| // Otherwise, break down all the fields for comparison. Hopefully these |
| // little Constants are reused, while a big null struct might not be. |
| llvm::SmallVector<llvm::Constant *, 4> Fields; |
| GetNullMemberPointerFields(MPT, Fields); |
| if (Fields.size() == 1) { |
| assert(Val->getType()->isIntegerTy()); |
| return Val == Fields[0]; |
| } |
| |
| unsigned I, E; |
| for (I = 0, E = Fields.size(); I != E; ++I) { |
| if (Val->getAggregateElement(I) != Fields[I]) |
| break; |
| } |
| return I == E; |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF, |
| llvm::Value *This, |
| llvm::Value *VBPtrOffset, |
| llvm::Value *VBTableOffset, |
| llvm::Value **VBPtrOut) { |
| CGBuilderTy &Builder = CGF.Builder; |
| // Load the vbtable pointer from the vbptr in the instance. |
| This = Builder.CreateBitCast(This, CGM.Int8PtrTy); |
| llvm::Value *VBPtr = |
| Builder.CreateInBoundsGEP(This, VBPtrOffset, "vbptr"); |
| if (VBPtrOut) *VBPtrOut = VBPtr; |
| VBPtr = Builder.CreateBitCast(VBPtr, CGM.Int8PtrTy->getPointerTo(0)); |
| llvm::Value *VBTable = Builder.CreateLoad(VBPtr, "vbtable"); |
| |
| // Load an i32 offset from the vb-table. |
| llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableOffset); |
| VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0)); |
| return Builder.CreateLoad(VBaseOffs, "vbase_offs"); |
| } |
| |
| // 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 *VBTableOffset, |
| 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(VBTableOffset, 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 = CharUnits::Zero(); |
| if (RD->getNumVBases()) { |
| offs = GetVBPtrOffsetFromBases(RD); |
| } |
| VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity()); |
| } |
| llvm::Value *VBPtr = 0; |
| llvm::Value *VBaseOffs = |
| GetVBaseOffsetFromVBPtr(CGF, Base, VBPtrOffset, VBTableOffset, &VBPtr); |
| 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); |
| } |
| |
| static MSInheritanceModel |
| getInheritanceFromMemptr(const MemberPointerType *MPT) { |
| return MPT->getClass()->getAsCXXRecordDecl()->getMSInheritanceModel(); |
| } |
| |
| llvm::Value * |
| MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF, |
| const CastExpr *E, |
| llvm::Value *Src) { |
| assert(E->getCastKind() == CK_DerivedToBaseMemberPointer || |
| E->getCastKind() == CK_BaseToDerivedMemberPointer || |
| E->getCastKind() == CK_ReinterpretMemberPointer); |
| |
| // Use constant emission if we can. |
| if (isa<llvm::Constant>(Src)) |
| return EmitMemberPointerConversion(E, cast<llvm::Constant>(Src)); |
| |
| // We may be adding or dropping fields from the member pointer, so we need |
| // both types and the inheritance models of both records. |
| const MemberPointerType *SrcTy = |
| E->getSubExpr()->getType()->castAs<MemberPointerType>(); |
| const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>(); |
| MSInheritanceModel SrcInheritance = getInheritanceFromMemptr(SrcTy); |
| MSInheritanceModel DstInheritance = getInheritanceFromMemptr(DstTy); |
| bool IsFunc = SrcTy->isMemberFunctionPointer(); |
| |
| // If the classes use the same null representation, reinterpret_cast is a nop. |
| bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer; |
| if (IsReinterpret && (IsFunc || |
| nullFieldOffsetIsZero(SrcInheritance) == |
| nullFieldOffsetIsZero(DstInheritance))) |
| return Src; |
| |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| // Branch past the conversion if Src is null. |
| llvm::Value *IsNotNull = EmitMemberPointerIsNotNull(CGF, Src, SrcTy); |
| llvm::Constant *DstNull = EmitNullMemberPointer(DstTy); |
| |
| // C++ 5.2.10p9: The null member pointer value is converted to the null member |
| // pointer value of the destination type. |
| if (IsReinterpret) { |
| // For reinterpret casts, sema ensures that src and dst are both functions |
| // or data and have the same size, which means the LLVM types should match. |
| assert(Src->getType() == DstNull->getType()); |
| return Builder.CreateSelect(IsNotNull, Src, DstNull); |
| } |
| |
| llvm::BasicBlock *OriginalBB = Builder.GetInsertBlock(); |
| llvm::BasicBlock *ConvertBB = CGF.createBasicBlock("memptr.convert"); |
| llvm::BasicBlock *ContinueBB = CGF.createBasicBlock("memptr.converted"); |
| Builder.CreateCondBr(IsNotNull, ConvertBB, ContinueBB); |
| CGF.EmitBlock(ConvertBB); |
| |
| // Decompose src. |
| llvm::Value *FirstField = Src; |
| llvm::Value *NonVirtualBaseAdjustment = 0; |
| llvm::Value *VirtualBaseAdjustmentOffset = 0; |
| llvm::Value *VBPtrOffset = 0; |
| if (!hasOnlyOneField(IsFunc, SrcInheritance)) { |
| // We need to extract values. |
| unsigned I = 0; |
| FirstField = Builder.CreateExtractValue(Src, I++); |
| if (hasNonVirtualBaseAdjustmentField(IsFunc, SrcInheritance)) |
| NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++); |
| if (hasVBPtrOffsetField(SrcInheritance)) |
| VBPtrOffset = Builder.CreateExtractValue(Src, I++); |
| if (hasVirtualBaseAdjustmentField(SrcInheritance)) |
| VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++); |
| } |
| |
| // For data pointers, we adjust the field offset directly. For functions, we |
| // have a separate field. |
| llvm::Constant *Adj = getMemberPointerAdjustment(E); |
| if (Adj) { |
| Adj = llvm::ConstantExpr::getTruncOrBitCast(Adj, CGM.IntTy); |
| llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField; |
| bool isDerivedToBase = (E->getCastKind() == CK_DerivedToBaseMemberPointer); |
| if (!NVAdjustField) // If this field didn't exist in src, it's zero. |
| NVAdjustField = getZeroInt(); |
| if (isDerivedToBase) |
| NVAdjustField = Builder.CreateNSWSub(NVAdjustField, Adj, "adj"); |
| else |
| NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, Adj, "adj"); |
| } |
| |
| // FIXME PR15713: Support conversions through virtually derived classes. |
| |
| // Recompose dst from the null struct and the adjusted fields from src. |
| llvm::Value *Dst; |
| if (hasOnlyOneField(IsFunc, DstInheritance)) { |
| Dst = FirstField; |
| } else { |
| Dst = llvm::UndefValue::get(DstNull->getType()); |
| unsigned Idx = 0; |
| Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++); |
| if (hasNonVirtualBaseAdjustmentField(IsFunc, DstInheritance)) |
| Dst = Builder.CreateInsertValue( |
| Dst, getValueOrZeroInt(NonVirtualBaseAdjustment), Idx++); |
| if (hasVBPtrOffsetField(DstInheritance)) |
| Dst = Builder.CreateInsertValue( |
| Dst, getValueOrZeroInt(VBPtrOffset), Idx++); |
| if (hasVirtualBaseAdjustmentField(DstInheritance)) |
| Dst = Builder.CreateInsertValue( |
| Dst, getValueOrZeroInt(VirtualBaseAdjustmentOffset), Idx++); |
| } |
| Builder.CreateBr(ContinueBB); |
| |
| // In the continuation, choose between DstNull and Dst. |
| CGF.EmitBlock(ContinueBB); |
| llvm::PHINode *Phi = Builder.CreatePHI(DstNull->getType(), 2, "memptr.converted"); |
| Phi->addIncoming(DstNull, OriginalBB); |
| Phi->addIncoming(Dst, ConvertBB); |
| return Phi; |
| } |
| |
| llvm::Constant * |
| MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E, |
| llvm::Constant *Src) { |
| const MemberPointerType *SrcTy = |
| E->getSubExpr()->getType()->castAs<MemberPointerType>(); |
| const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>(); |
| |
| // If src is null, emit a new null for dst. We can't return src because dst |
| // might have a new representation. |
| if (MemberPointerConstantIsNull(SrcTy, Src)) |
| return EmitNullMemberPointer(DstTy); |
| |
| // We don't need to do anything for reinterpret_casts of non-null member |
| // pointers. We should only get here when the two type representations have |
| // the same size. |
| if (E->getCastKind() == CK_ReinterpretMemberPointer) |
| return Src; |
| |
| MSInheritanceModel SrcInheritance = getInheritanceFromMemptr(SrcTy); |
| MSInheritanceModel DstInheritance = getInheritanceFromMemptr(DstTy); |
| |
| // Decompose src. |
| llvm::Constant *FirstField = Src; |
| llvm::Constant *NonVirtualBaseAdjustment = 0; |
| llvm::Constant *VirtualBaseAdjustmentOffset = 0; |
| llvm::Constant *VBPtrOffset = 0; |
| bool IsFunc = SrcTy->isMemberFunctionPointer(); |
| if (!hasOnlyOneField(IsFunc, SrcInheritance)) { |
| // We need to extract values. |
| unsigned I = 0; |
| FirstField = Src->getAggregateElement(I++); |
| if (hasNonVirtualBaseAdjustmentField(IsFunc, SrcInheritance)) |
| NonVirtualBaseAdjustment = Src->getAggregateElement(I++); |
| if (hasVBPtrOffsetField(SrcInheritance)) |
| VBPtrOffset = Src->getAggregateElement(I++); |
| if (hasVirtualBaseAdjustmentField(SrcInheritance)) |
| VirtualBaseAdjustmentOffset = Src->getAggregateElement(I++); |
| } |
| |
| // For data pointers, we adjust the field offset directly. For functions, we |
| // have a separate field. |
| llvm::Constant *Adj = getMemberPointerAdjustment(E); |
| if (Adj) { |
| Adj = llvm::ConstantExpr::getTruncOrBitCast(Adj, CGM.IntTy); |
| llvm::Constant *&NVAdjustField = |
| IsFunc ? NonVirtualBaseAdjustment : FirstField; |
| bool IsDerivedToBase = (E->getCastKind() == CK_DerivedToBaseMemberPointer); |
| if (!NVAdjustField) // If this field didn't exist in src, it's zero. |
| NVAdjustField = getZeroInt(); |
| if (IsDerivedToBase) |
| NVAdjustField = llvm::ConstantExpr::getNSWSub(NVAdjustField, Adj); |
| else |
| NVAdjustField = llvm::ConstantExpr::getNSWAdd(NVAdjustField, Adj); |
| } |
| |
| // FIXME PR15713: Support conversions through virtually derived classes. |
| |
| // Recompose dst from the null struct and the adjusted fields from src. |
| if (hasOnlyOneField(IsFunc, DstInheritance)) |
| return FirstField; |
| |
| llvm::SmallVector<llvm::Constant *, 4> Fields; |
| Fields.push_back(FirstField); |
| if (hasNonVirtualBaseAdjustmentField(IsFunc, DstInheritance)) |
| Fields.push_back(getConstantOrZeroInt(NonVirtualBaseAdjustment)); |
| if (hasVBPtrOffsetField(DstInheritance)) |
| Fields.push_back(getConstantOrZeroInt(VBPtrOffset)); |
| if (hasVirtualBaseAdjustmentField(DstInheritance)) |
| Fields.push_back(getConstantOrZeroInt(VirtualBaseAdjustmentOffset)); |
| return llvm::ConstantStruct::getAnon(Fields); |
| } |
| |
| 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); |
| } |