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4361 lines
176 KiB
4361 lines
176 KiB
//===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This provides C++ code generation targeting the Microsoft Visual C++ ABI.
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// The class in this file generates structures that follow the Microsoft
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// Visual C++ ABI, which is actually not very well documented at all outside
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// of Microsoft.
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//
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//===----------------------------------------------------------------------===//
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#include "CGCXXABI.h"
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#include "CGCleanup.h"
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#include "CGVTables.h"
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#include "CodeGenModule.h"
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#include "CodeGenTypes.h"
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#include "TargetInfo.h"
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#include "clang/AST/Attr.h"
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#include "clang/AST/CXXInheritance.h"
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#include "clang/AST/Decl.h"
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#include "clang/AST/DeclCXX.h"
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#include "clang/AST/StmtCXX.h"
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#include "clang/AST/VTableBuilder.h"
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#include "clang/CodeGen/ConstantInitBuilder.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/ADT/StringSet.h"
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#include "llvm/IR/Intrinsics.h"
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using namespace clang;
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using namespace CodeGen;
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namespace {
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/// Holds all the vbtable globals for a given class.
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struct VBTableGlobals {
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const VPtrInfoVector *VBTables;
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SmallVector<llvm::GlobalVariable *, 2> Globals;
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};
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class MicrosoftCXXABI : public CGCXXABI {
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public:
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MicrosoftCXXABI(CodeGenModule &CGM)
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: CGCXXABI(CGM), BaseClassDescriptorType(nullptr),
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ClassHierarchyDescriptorType(nullptr),
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CompleteObjectLocatorType(nullptr), CatchableTypeType(nullptr),
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ThrowInfoType(nullptr) {}
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bool HasThisReturn(GlobalDecl GD) const override;
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bool hasMostDerivedReturn(GlobalDecl GD) const override;
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bool classifyReturnType(CGFunctionInfo &FI) const override;
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RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override;
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bool isSRetParameterAfterThis() const override { return true; }
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bool isThisCompleteObject(GlobalDecl GD) const override {
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// The Microsoft ABI doesn't use separate complete-object vs.
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// base-object variants of constructors, but it does of destructors.
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if (isa<CXXDestructorDecl>(GD.getDecl())) {
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switch (GD.getDtorType()) {
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case Dtor_Complete:
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case Dtor_Deleting:
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return true;
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case Dtor_Base:
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return false;
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case Dtor_Comdat: llvm_unreachable("emitting dtor comdat as function?");
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}
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llvm_unreachable("bad dtor kind");
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}
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// No other kinds.
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return false;
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}
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size_t getSrcArgforCopyCtor(const CXXConstructorDecl *CD,
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FunctionArgList &Args) const override {
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assert(Args.size() >= 2 &&
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"expected the arglist to have at least two args!");
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// The 'most_derived' parameter goes second if the ctor is variadic and
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// has v-bases.
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if (CD->getParent()->getNumVBases() > 0 &&
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CD->getType()->castAs<FunctionProtoType>()->isVariadic())
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return 2;
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return 1;
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}
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std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD) override {
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std::vector<CharUnits> VBPtrOffsets;
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const ASTContext &Context = getContext();
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const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
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const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
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for (const std::unique_ptr<VPtrInfo> &VBT : *VBGlobals.VBTables) {
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const ASTRecordLayout &SubobjectLayout =
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Context.getASTRecordLayout(VBT->IntroducingObject);
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CharUnits Offs = VBT->NonVirtualOffset;
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Offs += SubobjectLayout.getVBPtrOffset();
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if (VBT->getVBaseWithVPtr())
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Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
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VBPtrOffsets.push_back(Offs);
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}
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llvm::array_pod_sort(VBPtrOffsets.begin(), VBPtrOffsets.end());
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return VBPtrOffsets;
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}
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StringRef GetPureVirtualCallName() override { return "_purecall"; }
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StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
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void emitVirtualObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
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Address Ptr, QualType ElementType,
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const CXXDestructorDecl *Dtor) override;
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void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override;
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void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) override;
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void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
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llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
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const VPtrInfo &Info);
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llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
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CatchTypeInfo
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getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
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/// MSVC needs an extra flag to indicate a catchall.
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CatchTypeInfo getCatchAllTypeInfo() override {
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return CatchTypeInfo{nullptr, 0x40};
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}
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bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
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void EmitBadTypeidCall(CodeGenFunction &CGF) override;
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llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
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Address ThisPtr,
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llvm::Type *StdTypeInfoPtrTy) override;
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bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
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QualType SrcRecordTy) override;
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llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
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QualType SrcRecordTy, QualType DestTy,
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QualType DestRecordTy,
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llvm::BasicBlock *CastEnd) override;
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llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
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QualType SrcRecordTy,
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QualType DestTy) override;
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bool EmitBadCastCall(CodeGenFunction &CGF) override;
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bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
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return false;
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}
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llvm::Value *
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GetVirtualBaseClassOffset(CodeGenFunction &CGF, Address This,
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const CXXRecordDecl *ClassDecl,
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const CXXRecordDecl *BaseClassDecl) override;
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llvm::BasicBlock *
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EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
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const CXXRecordDecl *RD) override;
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llvm::BasicBlock *
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EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
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void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
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const CXXRecordDecl *RD) override;
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void EmitCXXConstructors(const CXXConstructorDecl *D) override;
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// Background on MSVC destructors
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// ==============================
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//
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// Both Itanium and MSVC ABIs have destructor variants. The variant names
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// roughly correspond in the following way:
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// Itanium Microsoft
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// Base -> no name, just ~Class
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// Complete -> vbase destructor
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// Deleting -> scalar deleting destructor
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// vector deleting destructor
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//
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// The base and complete destructors are the same as in Itanium, although the
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// complete destructor does not accept a VTT parameter when there are virtual
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// bases. A separate mechanism involving vtordisps is used to ensure that
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// virtual methods of destroyed subobjects are not called.
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//
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// The deleting destructors accept an i32 bitfield as a second parameter. Bit
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// 1 indicates if the memory should be deleted. Bit 2 indicates if the this
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// pointer points to an array. The scalar deleting destructor assumes that
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// bit 2 is zero, and therefore does not contain a loop.
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//
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// For virtual destructors, only one entry is reserved in the vftable, and it
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// always points to the vector deleting destructor. The vector deleting
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// destructor is the most general, so it can be used to destroy objects in
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// place, delete single heap objects, or delete arrays.
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//
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// A TU defining a non-inline destructor is only guaranteed to emit a base
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// destructor, and all of the other variants are emitted on an as-needed basis
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// in COMDATs. Because a non-base destructor can be emitted in a TU that
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// lacks a definition for the destructor, non-base destructors must always
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// delegate to or alias the base destructor.
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AddedStructorArgCounts
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buildStructorSignature(GlobalDecl GD,
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SmallVectorImpl<CanQualType> &ArgTys) override;
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/// Non-base dtors should be emitted as delegating thunks in this ABI.
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bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
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CXXDtorType DT) const override {
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return DT != Dtor_Base;
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}
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void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
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const CXXDestructorDecl *Dtor,
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CXXDtorType DT) const override;
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llvm::GlobalValue::LinkageTypes
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getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
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CXXDtorType DT) const override;
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void EmitCXXDestructors(const CXXDestructorDecl *D) override;
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const CXXRecordDecl *
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getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
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if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
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MethodVFTableLocation ML =
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CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
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// The vbases might be ordered differently in the final overrider object
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// and the complete object, so the "this" argument may sometimes point to
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// memory that has no particular type (e.g. past the complete object).
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// In this case, we just use a generic pointer type.
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// FIXME: might want to have a more precise type in the non-virtual
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// multiple inheritance case.
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if (ML.VBase || !ML.VFPtrOffset.isZero())
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return nullptr;
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}
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return MD->getParent();
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}
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Address
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adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
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Address This,
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bool VirtualCall) override;
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void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
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FunctionArgList &Params) override;
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void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
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AddedStructorArgs getImplicitConstructorArgs(CodeGenFunction &CGF,
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const CXXConstructorDecl *D,
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CXXCtorType Type,
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bool ForVirtualBase,
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bool Delegating) override;
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llvm::Value *getCXXDestructorImplicitParam(CodeGenFunction &CGF,
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const CXXDestructorDecl *DD,
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CXXDtorType Type,
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bool ForVirtualBase,
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bool Delegating) override;
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void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
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CXXDtorType Type, bool ForVirtualBase,
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bool Delegating, Address This,
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QualType ThisTy) override;
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void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
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llvm::GlobalVariable *VTable);
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void emitVTableDefinitions(CodeGenVTables &CGVT,
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const CXXRecordDecl *RD) override;
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bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
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CodeGenFunction::VPtr Vptr) override;
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/// Don't initialize vptrs if dynamic class
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/// is marked with with the 'novtable' attribute.
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bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
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return !VTableClass->hasAttr<MSNoVTableAttr>();
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}
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llvm::Constant *
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getVTableAddressPoint(BaseSubobject Base,
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const CXXRecordDecl *VTableClass) override;
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llvm::Value *getVTableAddressPointInStructor(
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CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
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BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
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llvm::Constant *
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getVTableAddressPointForConstExpr(BaseSubobject Base,
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const CXXRecordDecl *VTableClass) override;
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llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
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CharUnits VPtrOffset) override;
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CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
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Address This, llvm::Type *Ty,
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SourceLocation Loc) override;
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llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
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const CXXDestructorDecl *Dtor,
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CXXDtorType DtorType, Address This,
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DeleteOrMemberCallExpr E) override;
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void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
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CallArgList &CallArgs) override {
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assert(GD.getDtorType() == Dtor_Deleting &&
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"Only deleting destructor thunks are available in this ABI");
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CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
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getContext().IntTy);
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}
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void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
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llvm::GlobalVariable *
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getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
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llvm::GlobalVariable::LinkageTypes Linkage);
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llvm::GlobalVariable *
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getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
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const CXXRecordDecl *DstRD) {
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SmallString<256> OutName;
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llvm::raw_svector_ostream Out(OutName);
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getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
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StringRef MangledName = OutName.str();
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if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
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return VDispMap;
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MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
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unsigned NumEntries = 1 + SrcRD->getNumVBases();
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SmallVector<llvm::Constant *, 4> Map(NumEntries,
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llvm::UndefValue::get(CGM.IntTy));
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Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
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bool AnyDifferent = false;
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for (const auto &I : SrcRD->vbases()) {
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const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
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if (!DstRD->isVirtuallyDerivedFrom(VBase))
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continue;
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unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
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unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
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Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
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AnyDifferent |= SrcVBIndex != DstVBIndex;
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}
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// This map would be useless, don't use it.
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if (!AnyDifferent)
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return nullptr;
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llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
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llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
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llvm::GlobalValue::LinkageTypes Linkage =
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SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
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? llvm::GlobalValue::LinkOnceODRLinkage
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: llvm::GlobalValue::InternalLinkage;
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auto *VDispMap = new llvm::GlobalVariable(
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CGM.getModule(), VDispMapTy, /*isConstant=*/true, Linkage,
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/*Initializer=*/Init, MangledName);
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return VDispMap;
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}
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void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
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llvm::GlobalVariable *GV) const;
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void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
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GlobalDecl GD, bool ReturnAdjustment) override {
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GVALinkage Linkage =
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getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
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if (Linkage == GVA_Internal)
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Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
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else if (ReturnAdjustment)
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Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
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else
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Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
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}
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bool exportThunk() override { return false; }
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llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
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const ThisAdjustment &TA) override;
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llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
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const ReturnAdjustment &RA) override;
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void EmitThreadLocalInitFuncs(
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CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
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ArrayRef<llvm::Function *> CXXThreadLocalInits,
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ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
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bool usesThreadWrapperFunction(const VarDecl *VD) const override {
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return false;
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}
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LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
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QualType LValType) override;
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void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
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llvm::GlobalVariable *DeclPtr,
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bool PerformInit) override;
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void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
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llvm::FunctionCallee Dtor,
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llvm::Constant *Addr) override;
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// ==== Notes on array cookies =========
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//
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// MSVC seems to only use cookies when the class has a destructor; a
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// two-argument usual array deallocation function isn't sufficient.
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//
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// For example, this code prints "100" and "1":
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// struct A {
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// char x;
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// void *operator new[](size_t sz) {
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// printf("%u\n", sz);
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// return malloc(sz);
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// }
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// void operator delete[](void *p, size_t sz) {
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// printf("%u\n", sz);
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// free(p);
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// }
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// };
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// int main() {
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// A *p = new A[100];
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// delete[] p;
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// }
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// Whereas it prints "104" and "104" if you give A a destructor.
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bool requiresArrayCookie(const CXXDeleteExpr *expr,
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QualType elementType) override;
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bool requiresArrayCookie(const CXXNewExpr *expr) override;
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CharUnits getArrayCookieSizeImpl(QualType type) override;
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Address InitializeArrayCookie(CodeGenFunction &CGF,
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Address NewPtr,
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llvm::Value *NumElements,
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const CXXNewExpr *expr,
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QualType ElementType) override;
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llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
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Address allocPtr,
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CharUnits cookieSize) override;
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friend struct MSRTTIBuilder;
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bool isImageRelative() const {
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return CGM.getTarget().getPointerWidth(/*AddrSpace=*/0) == 64;
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}
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// 5 routines for constructing the llvm types for MS RTTI structs.
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llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
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llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
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TDTypeName += llvm::utostr(TypeInfoString.size());
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llvm::StructType *&TypeDescriptorType =
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TypeDescriptorTypeMap[TypeInfoString.size()];
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if (TypeDescriptorType)
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return TypeDescriptorType;
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llvm::Type *FieldTypes[] = {
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CGM.Int8PtrPtrTy,
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CGM.Int8PtrTy,
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llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
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TypeDescriptorType =
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llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
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return TypeDescriptorType;
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}
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|
llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
|
|
if (!isImageRelative())
|
|
return PtrType;
|
|
return CGM.IntTy;
|
|
}
|
|
|
|
llvm::StructType *getBaseClassDescriptorType() {
|
|
if (BaseClassDescriptorType)
|
|
return BaseClassDescriptorType;
|
|
llvm::Type *FieldTypes[] = {
|
|
getImageRelativeType(CGM.Int8PtrTy),
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
|
|
};
|
|
BaseClassDescriptorType = llvm::StructType::create(
|
|
CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
|
|
return BaseClassDescriptorType;
|
|
}
|
|
|
|
llvm::StructType *getClassHierarchyDescriptorType() {
|
|
if (ClassHierarchyDescriptorType)
|
|
return ClassHierarchyDescriptorType;
|
|
// Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
|
|
ClassHierarchyDescriptorType = llvm::StructType::create(
|
|
CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
|
|
llvm::Type *FieldTypes[] = {
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
getImageRelativeType(
|
|
getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
|
|
};
|
|
ClassHierarchyDescriptorType->setBody(FieldTypes);
|
|
return ClassHierarchyDescriptorType;
|
|
}
|
|
|
|
llvm::StructType *getCompleteObjectLocatorType() {
|
|
if (CompleteObjectLocatorType)
|
|
return CompleteObjectLocatorType;
|
|
CompleteObjectLocatorType = llvm::StructType::create(
|
|
CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
|
|
llvm::Type *FieldTypes[] = {
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
CGM.IntTy,
|
|
getImageRelativeType(CGM.Int8PtrTy),
|
|
getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
|
|
getImageRelativeType(CompleteObjectLocatorType),
|
|
};
|
|
llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
|
|
if (!isImageRelative())
|
|
FieldTypesRef = FieldTypesRef.drop_back();
|
|
CompleteObjectLocatorType->setBody(FieldTypesRef);
|
|
return CompleteObjectLocatorType;
|
|
}
|
|
|
|
llvm::GlobalVariable *getImageBase() {
|
|
StringRef Name = "__ImageBase";
|
|
if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
|
|
return GV;
|
|
|
|
auto *GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
|
|
/*isConstant=*/true,
|
|
llvm::GlobalValue::ExternalLinkage,
|
|
/*Initializer=*/nullptr, Name);
|
|
CGM.setDSOLocal(GV);
|
|
return GV;
|
|
}
|
|
|
|
llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
|
|
if (!isImageRelative())
|
|
return PtrVal;
|
|
|
|
if (PtrVal->isNullValue())
|
|
return llvm::Constant::getNullValue(CGM.IntTy);
|
|
|
|
llvm::Constant *ImageBaseAsInt =
|
|
llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
|
|
llvm::Constant *PtrValAsInt =
|
|
llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
|
|
llvm::Constant *Diff =
|
|
llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
|
|
/*HasNUW=*/true, /*HasNSW=*/true);
|
|
return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
|
|
|
|
void
|
|
GetNullMemberPointerFields(const MemberPointerType *MPT,
|
|
llvm::SmallVectorImpl<llvm::Constant *> &fields);
|
|
|
|
/// 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,
|
|
Address Base,
|
|
llvm::Value *VBPtrOffset,
|
|
llvm::Value *VBTableOffset,
|
|
llvm::Value **VBPtr = nullptr);
|
|
|
|
llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
|
|
Address Base,
|
|
int32_t VBPtrOffset,
|
|
int32_t VBTableOffset,
|
|
llvm::Value **VBPtr = nullptr) {
|
|
assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
|
|
llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
|
|
*VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
|
|
return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
|
|
}
|
|
|
|
std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
|
|
performBaseAdjustment(CodeGenFunction &CGF, Address Value,
|
|
QualType SrcRecordTy);
|
|
|
|
/// Performs a full virtual base adjustment. Used to dereference
|
|
/// pointers to members of virtual bases.
|
|
llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
|
|
const CXXRecordDecl *RD, Address Base,
|
|
llvm::Value *VirtualBaseAdjustmentOffset,
|
|
llvm::Value *VBPtrOffset /* optional */);
|
|
|
|
/// 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,
|
|
unsigned VBTableIndex);
|
|
|
|
bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
|
|
llvm::Constant *MP);
|
|
|
|
/// - Initialize all vbptrs of 'this' with RD as the complete type.
|
|
void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
|
|
|
|
/// Caching wrapper around VBTableBuilder::enumerateVBTables().
|
|
const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
|
|
|
|
/// Generate a thunk for calling a virtual member function MD.
|
|
llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
|
|
const MethodVFTableLocation &ML);
|
|
|
|
llvm::Constant *EmitMemberDataPointer(const CXXRecordDecl *RD,
|
|
CharUnits offset);
|
|
|
|
public:
|
|
llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
|
|
|
|
bool isZeroInitializable(const MemberPointerType *MPT) override;
|
|
|
|
bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
|
|
const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
|
|
return RD->hasAttr<MSInheritanceAttr>();
|
|
}
|
|
|
|
llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
|
|
|
|
llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
|
|
CharUnits offset) override;
|
|
llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
|
|
llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
|
|
|
|
llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
|
|
llvm::Value *L,
|
|
llvm::Value *R,
|
|
const MemberPointerType *MPT,
|
|
bool Inequality) override;
|
|
|
|
llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
|
|
llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) override;
|
|
|
|
llvm::Value *
|
|
EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
|
|
Address Base, llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) override;
|
|
|
|
llvm::Value *EmitNonNullMemberPointerConversion(
|
|
const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
|
|
CastKind CK, CastExpr::path_const_iterator PathBegin,
|
|
CastExpr::path_const_iterator PathEnd, llvm::Value *Src,
|
|
CGBuilderTy &Builder);
|
|
|
|
llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
|
|
const CastExpr *E,
|
|
llvm::Value *Src) override;
|
|
|
|
llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
|
|
llvm::Constant *Src) override;
|
|
|
|
llvm::Constant *EmitMemberPointerConversion(
|
|
const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
|
|
CastKind CK, CastExpr::path_const_iterator PathBegin,
|
|
CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
|
|
|
|
CGCallee
|
|
EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
|
|
Address This, llvm::Value *&ThisPtrForCall,
|
|
llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) override;
|
|
|
|
void emitCXXStructor(GlobalDecl GD) override;
|
|
|
|
llvm::StructType *getCatchableTypeType() {
|
|
if (CatchableTypeType)
|
|
return CatchableTypeType;
|
|
llvm::Type *FieldTypes[] = {
|
|
CGM.IntTy, // Flags
|
|
getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
|
|
CGM.IntTy, // NonVirtualAdjustment
|
|
CGM.IntTy, // OffsetToVBPtr
|
|
CGM.IntTy, // VBTableIndex
|
|
CGM.IntTy, // Size
|
|
getImageRelativeType(CGM.Int8PtrTy) // CopyCtor
|
|
};
|
|
CatchableTypeType = llvm::StructType::create(
|
|
CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
|
|
return CatchableTypeType;
|
|
}
|
|
|
|
llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
|
|
llvm::StructType *&CatchableTypeArrayType =
|
|
CatchableTypeArrayTypeMap[NumEntries];
|
|
if (CatchableTypeArrayType)
|
|
return CatchableTypeArrayType;
|
|
|
|
llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
|
|
CTATypeName += llvm::utostr(NumEntries);
|
|
llvm::Type *CTType =
|
|
getImageRelativeType(getCatchableTypeType()->getPointerTo());
|
|
llvm::Type *FieldTypes[] = {
|
|
CGM.IntTy, // NumEntries
|
|
llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
|
|
};
|
|
CatchableTypeArrayType =
|
|
llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
|
|
return CatchableTypeArrayType;
|
|
}
|
|
|
|
llvm::StructType *getThrowInfoType() {
|
|
if (ThrowInfoType)
|
|
return ThrowInfoType;
|
|
llvm::Type *FieldTypes[] = {
|
|
CGM.IntTy, // Flags
|
|
getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
|
|
getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
|
|
getImageRelativeType(CGM.Int8PtrTy) // CatchableTypeArray
|
|
};
|
|
ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
|
|
"eh.ThrowInfo");
|
|
return ThrowInfoType;
|
|
}
|
|
|
|
llvm::FunctionCallee getThrowFn() {
|
|
// _CxxThrowException is passed an exception object and a ThrowInfo object
|
|
// which describes the exception.
|
|
llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
|
|
llvm::FunctionCallee Throw =
|
|
CGM.CreateRuntimeFunction(FTy, "_CxxThrowException");
|
|
// _CxxThrowException is stdcall on 32-bit x86 platforms.
|
|
if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
|
|
if (auto *Fn = dyn_cast<llvm::Function>(Throw.getCallee()))
|
|
Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
|
|
}
|
|
return Throw;
|
|
}
|
|
|
|
llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
|
|
CXXCtorType CT);
|
|
|
|
llvm::Constant *getCatchableType(QualType T,
|
|
uint32_t NVOffset = 0,
|
|
int32_t VBPtrOffset = -1,
|
|
uint32_t VBIndex = 0);
|
|
|
|
llvm::GlobalVariable *getCatchableTypeArray(QualType T);
|
|
|
|
llvm::GlobalVariable *getThrowInfo(QualType T) override;
|
|
|
|
std::pair<llvm::Value *, const CXXRecordDecl *>
|
|
LoadVTablePtr(CodeGenFunction &CGF, Address This,
|
|
const CXXRecordDecl *RD) override;
|
|
|
|
private:
|
|
typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
|
|
typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
|
|
typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
|
|
/// All the vftables that have been referenced.
|
|
VFTablesMapTy VFTablesMap;
|
|
VTablesMapTy VTablesMap;
|
|
|
|
/// This set holds the record decls we've deferred vtable emission for.
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
|
|
|
|
|
|
/// All the vbtables which have been referenced.
|
|
llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> 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(nullptr), 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::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
|
|
llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
|
|
|
|
llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
|
|
llvm::StructType *BaseClassDescriptorType;
|
|
llvm::StructType *ClassHierarchyDescriptorType;
|
|
llvm::StructType *CompleteObjectLocatorType;
|
|
|
|
llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
|
|
|
|
llvm::StructType *CatchableTypeType;
|
|
llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
|
|
llvm::StructType *ThrowInfoType;
|
|
};
|
|
|
|
}
|
|
|
|
CGCXXABI::RecordArgABI
|
|
MicrosoftCXXABI::getRecordArgABI(const CXXRecordDecl *RD) const {
|
|
// Use the default C calling convention rules for things that can be passed in
|
|
// registers, i.e. non-trivially copyable records or records marked with
|
|
// [[trivial_abi]].
|
|
if (RD->canPassInRegisters())
|
|
return RAA_Default;
|
|
|
|
switch (CGM.getTarget().getTriple().getArch()) {
|
|
default:
|
|
// FIXME: Implement for other architectures.
|
|
return RAA_Indirect;
|
|
|
|
case llvm::Triple::thumb:
|
|
// Pass things indirectly for now because it is simple.
|
|
// FIXME: This is incompatible with MSVC for arguments with a dtor and no
|
|
// copy ctor.
|
|
return RAA_Indirect;
|
|
|
|
case llvm::Triple::x86: {
|
|
// If the argument has *required* alignment greater than four bytes, pass
|
|
// it indirectly. Prior to MSVC version 19.14, passing overaligned
|
|
// arguments was not supported and resulted in a compiler error. In 19.14
|
|
// and later versions, such arguments are now passed indirectly.
|
|
TypeInfo Info = getContext().getTypeInfo(RD->getTypeForDecl());
|
|
if (Info.AlignIsRequired && Info.Align > 4)
|
|
return RAA_Indirect;
|
|
|
|
// If C++ prohibits us from making a copy, construct the arguments directly
|
|
// into argument memory.
|
|
return RAA_DirectInMemory;
|
|
}
|
|
|
|
case llvm::Triple::x86_64:
|
|
case llvm::Triple::aarch64:
|
|
return RAA_Indirect;
|
|
}
|
|
|
|
llvm_unreachable("invalid enum");
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
|
|
const CXXDeleteExpr *DE,
|
|
Address Ptr,
|
|
QualType ElementType,
|
|
const CXXDestructorDecl *Dtor) {
|
|
// FIXME: Provide a source location here even though there's no
|
|
// CXXMemberCallExpr for dtor call.
|
|
bool UseGlobalDelete = DE->isGlobalDelete();
|
|
CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
|
|
llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
|
|
if (UseGlobalDelete)
|
|
CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
|
|
llvm::Value *Args[] = {
|
|
llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
|
|
llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
|
|
llvm::FunctionCallee Fn = getThrowFn();
|
|
if (isNoReturn)
|
|
CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
|
|
else
|
|
CGF.EmitRuntimeCallOrInvoke(Fn, Args);
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
|
|
const CXXCatchStmt *S) {
|
|
// In the MS ABI, the runtime handles the copy, and the catch handler is
|
|
// responsible for destruction.
|
|
VarDecl *CatchParam = S->getExceptionDecl();
|
|
llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
|
|
llvm::CatchPadInst *CPI =
|
|
cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
|
|
CGF.CurrentFuncletPad = CPI;
|
|
|
|
// If this is a catch-all or the catch parameter is unnamed, we don't need to
|
|
// emit an alloca to the object.
|
|
if (!CatchParam || !CatchParam->getDeclName()) {
|
|
CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
|
|
return;
|
|
}
|
|
|
|
CodeGenFunction::AutoVarEmission var = CGF.EmitAutoVarAlloca(*CatchParam);
|
|
CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
|
|
CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
|
|
CGF.EmitAutoVarCleanups(var);
|
|
}
|
|
|
|
/// We need to perform a generic polymorphic operation (like a typeid
|
|
/// or a cast), which requires an object with a vfptr. Adjust the
|
|
/// address to point to an object with a vfptr.
|
|
std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
|
|
MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
|
|
QualType SrcRecordTy) {
|
|
Value = CGF.Builder.CreateBitCast(Value, CGF.Int8PtrTy);
|
|
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
|
|
const ASTContext &Context = getContext();
|
|
|
|
// If the class itself has a vfptr, great. This check implicitly
|
|
// covers non-virtual base subobjects: a class with its own virtual
|
|
// functions would be a candidate to be a primary base.
|
|
if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
|
|
return std::make_tuple(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0),
|
|
SrcDecl);
|
|
|
|
// Okay, one of the vbases must have a vfptr, or else this isn't
|
|
// actually a polymorphic class.
|
|
const CXXRecordDecl *PolymorphicBase = nullptr;
|
|
for (auto &Base : SrcDecl->vbases()) {
|
|
const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
|
|
if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
|
|
PolymorphicBase = BaseDecl;
|
|
break;
|
|
}
|
|
}
|
|
assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
|
|
|
|
llvm::Value *Offset =
|
|
GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
|
|
llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(Value.getPointer(), Offset);
|
|
CharUnits VBaseAlign =
|
|
CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
|
|
return std::make_tuple(Address(Ptr, VBaseAlign), Offset, PolymorphicBase);
|
|
}
|
|
|
|
bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
|
|
QualType SrcRecordTy) {
|
|
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
|
|
return IsDeref &&
|
|
!getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
|
|
}
|
|
|
|
static llvm::CallBase *emitRTtypeidCall(CodeGenFunction &CGF,
|
|
llvm::Value *Argument) {
|
|
llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
|
|
llvm::Value *Args[] = {Argument};
|
|
llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
|
|
return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
|
|
llvm::CallBase *Call =
|
|
emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
|
|
Call->setDoesNotReturn();
|
|
CGF.Builder.CreateUnreachable();
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
|
|
QualType SrcRecordTy,
|
|
Address ThisPtr,
|
|
llvm::Type *StdTypeInfoPtrTy) {
|
|
std::tie(ThisPtr, std::ignore, std::ignore) =
|
|
performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
|
|
llvm::CallBase *Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer());
|
|
return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
|
|
}
|
|
|
|
bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
|
|
QualType SrcRecordTy) {
|
|
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
|
|
return SrcIsPtr &&
|
|
!getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
|
|
CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
|
|
QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
|
|
llvm::Type *DestLTy = CGF.ConvertType(DestTy);
|
|
|
|
llvm::Value *SrcRTTI =
|
|
CGF.CGM.GetAddrOfRTTIDescriptor(SrcRecordTy.getUnqualifiedType());
|
|
llvm::Value *DestRTTI =
|
|
CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
|
|
|
|
llvm::Value *Offset;
|
|
std::tie(This, Offset, std::ignore) =
|
|
performBaseAdjustment(CGF, This, SrcRecordTy);
|
|
llvm::Value *ThisPtr = This.getPointer();
|
|
Offset = CGF.Builder.CreateTrunc(Offset, CGF.Int32Ty);
|
|
|
|
// PVOID __RTDynamicCast(
|
|
// PVOID inptr,
|
|
// LONG VfDelta,
|
|
// PVOID SrcType,
|
|
// PVOID TargetType,
|
|
// BOOL isReference)
|
|
llvm::Type *ArgTypes[] = {CGF.Int8PtrTy, CGF.Int32Ty, CGF.Int8PtrTy,
|
|
CGF.Int8PtrTy, CGF.Int32Ty};
|
|
llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
|
|
llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
|
|
"__RTDynamicCast");
|
|
llvm::Value *Args[] = {
|
|
ThisPtr, Offset, SrcRTTI, DestRTTI,
|
|
llvm::ConstantInt::get(CGF.Int32Ty, DestTy->isReferenceType())};
|
|
ThisPtr = CGF.EmitRuntimeCallOrInvoke(Function, Args);
|
|
return CGF.Builder.CreateBitCast(ThisPtr, DestLTy);
|
|
}
|
|
|
|
llvm::Value *
|
|
MicrosoftCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
|
|
QualType SrcRecordTy,
|
|
QualType DestTy) {
|
|
std::tie(Value, std::ignore, std::ignore) =
|
|
performBaseAdjustment(CGF, Value, SrcRecordTy);
|
|
|
|
// PVOID __RTCastToVoid(
|
|
// PVOID inptr)
|
|
llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
|
|
llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
|
|
llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
|
|
"__RTCastToVoid");
|
|
llvm::Value *Args[] = {Value.getPointer()};
|
|
return CGF.EmitRuntimeCall(Function, Args);
|
|
}
|
|
|
|
bool MicrosoftCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
|
|
return false;
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::GetVirtualBaseClassOffset(
|
|
CodeGenFunction &CGF, Address This, const CXXRecordDecl *ClassDecl,
|
|
const CXXRecordDecl *BaseClassDecl) {
|
|
const ASTContext &Context = getContext();
|
|
int64_t VBPtrChars =
|
|
Context.getASTRecordLayout(ClassDecl).getVBPtrOffset().getQuantity();
|
|
llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars);
|
|
CharUnits IntSize = Context.getTypeSizeInChars(Context.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());
|
|
}
|
|
|
|
static bool isDeletingDtor(GlobalDecl GD) {
|
|
return isa<CXXDestructorDecl>(GD.getDecl()) &&
|
|
GD.getDtorType() == Dtor_Deleting;
|
|
}
|
|
|
|
bool MicrosoftCXXABI::hasMostDerivedReturn(GlobalDecl GD) const {
|
|
return isDeletingDtor(GD);
|
|
}
|
|
|
|
static bool isCXX14Aggregate(const CXXRecordDecl *RD) {
|
|
// For AArch64, we use the C++14 definition of an aggregate, so we also
|
|
// check for:
|
|
// No private or protected non static data members.
|
|
// No base classes
|
|
// No virtual functions
|
|
// Additionally, we need to ensure that there is a trivial copy assignment
|
|
// operator, a trivial destructor and no user-provided constructors.
|
|
if (RD->hasProtectedFields() || RD->hasPrivateFields())
|
|
return false;
|
|
if (RD->getNumBases() > 0)
|
|
return false;
|
|
if (RD->isPolymorphic())
|
|
return false;
|
|
if (RD->hasNonTrivialCopyAssignment())
|
|
return false;
|
|
for (const CXXConstructorDecl *Ctor : RD->ctors())
|
|
if (Ctor->isUserProvided())
|
|
return false;
|
|
if (RD->hasNonTrivialDestructor())
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
bool MicrosoftCXXABI::classifyReturnType(CGFunctionInfo &FI) const {
|
|
const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
|
|
if (!RD)
|
|
return false;
|
|
|
|
// Normally, the C++ concept of "is trivially copyable" is used to determine
|
|
// if a struct can be returned directly. However, as MSVC and the language
|
|
// have evolved, the definition of "trivially copyable" has changed, while the
|
|
// ABI must remain stable. AArch64 uses the C++14 concept of an "aggregate",
|
|
// while other ISAs use the older concept of "plain old data".
|
|
bool isTrivialForABI = RD->isPOD();
|
|
bool isAArch64 = CGM.getTarget().getTriple().isAArch64();
|
|
if (isAArch64)
|
|
isTrivialForABI = RD->canPassInRegisters() && isCXX14Aggregate(RD);
|
|
|
|
// MSVC always returns structs indirectly from C++ instance methods.
|
|
bool isIndirectReturn = !isTrivialForABI || FI.isInstanceMethod();
|
|
|
|
if (isIndirectReturn) {
|
|
CharUnits Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
|
|
FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
|
|
|
|
// MSVC always passes `this` before the `sret` parameter.
|
|
FI.getReturnInfo().setSRetAfterThis(FI.isInstanceMethod());
|
|
|
|
// On AArch64, use the `inreg` attribute if the object is considered to not
|
|
// be trivially copyable, or if this is an instance method struct return.
|
|
FI.getReturnInfo().setInReg(isAArch64);
|
|
|
|
return true;
|
|
}
|
|
|
|
// Otherwise, use the C ABI rules.
|
|
return false;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
llvm::BasicBlock *
|
|
MicrosoftCXXABI::EmitDtorCompleteObjectHandler(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 *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
|
|
llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
|
|
CGF.Builder.CreateCondBr(IsCompleteObject,
|
|
CallVbaseDtorsBB, SkipVbaseDtorsBB);
|
|
|
|
CGF.EmitBlock(CallVbaseDtorsBB);
|
|
// CGF will put the base dtor calls in this basic block for us later.
|
|
|
|
return SkipVbaseDtorsBB;
|
|
}
|
|
|
|
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 = getThisAddress(CGF).getAddressSpace();
|
|
llvm::Value *Int8This = nullptr; // Initialize lazily.
|
|
|
|
for (const CXXBaseSpecifier &S : RD->vbases()) {
|
|
const CXXRecordDecl *VBase = S.getType()->getAsCXXRecordDecl();
|
|
auto I = VBaseMap.find(VBase);
|
|
assert(I != VBaseMap.end());
|
|
if (!I->second.hasVtorDisp())
|
|
continue;
|
|
|
|
llvm::Value *VBaseOffset =
|
|
GetVirtualBaseClassOffset(CGF, getThisAddress(CGF), RD, VBase);
|
|
uint64_t ConstantVBaseOffset = I->second.VBaseOffset.getQuantity();
|
|
|
|
// vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase).
|
|
llvm::Value *VtorDispValue = Builder.CreateSub(
|
|
VBaseOffset, llvm::ConstantInt::get(CGM.PtrDiffTy, ConstantVBaseOffset),
|
|
"vtordisp.value");
|
|
VtorDispValue = Builder.CreateTruncOrBitCast(VtorDispValue, CGF.Int32Ty);
|
|
|
|
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.CreateAlignedStore(VtorDispValue, VtorDispPtr,
|
|
CharUnits::fromQuantity(4));
|
|
}
|
|
}
|
|
|
|
static bool hasDefaultCXXMethodCC(ASTContext &Context,
|
|
const CXXMethodDecl *MD) {
|
|
CallingConv ExpectedCallingConv = Context.getDefaultCallingConvention(
|
|
/*IsVariadic=*/false, /*IsCXXMethod=*/true);
|
|
CallingConv ActualCallingConv =
|
|
MD->getType()->castAs<FunctionProtoType>()->getCallConv();
|
|
return ExpectedCallingConv == ActualCallingConv;
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
|
|
// There's only one constructor type in this ABI.
|
|
CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
|
|
|
|
// Exported default constructors either have a simple call-site where they use
|
|
// the typical calling convention and have a single 'this' pointer for an
|
|
// argument -or- they get a wrapper function which appropriately thunks to the
|
|
// real default constructor. This thunk is the default constructor closure.
|
|
if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor() &&
|
|
D->isDefined()) {
|
|
if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
|
|
llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
|
|
Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
|
|
CGM.setGVProperties(Fn, D);
|
|
}
|
|
}
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
|
|
const CXXRecordDecl *RD) {
|
|
Address This = getThisAddress(CGF);
|
|
This = CGF.Builder.CreateElementBitCast(This, CGM.Int8Ty, "this.int8");
|
|
const ASTContext &Context = getContext();
|
|
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
|
|
|
|
const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
|
|
for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
|
|
const std::unique_ptr<VPtrInfo> &VBT = (*VBGlobals.VBTables)[I];
|
|
llvm::GlobalVariable *GV = VBGlobals.Globals[I];
|
|
const ASTRecordLayout &SubobjectLayout =
|
|
Context.getASTRecordLayout(VBT->IntroducingObject);
|
|
CharUnits Offs = VBT->NonVirtualOffset;
|
|
Offs += SubobjectLayout.getVBPtrOffset();
|
|
if (VBT->getVBaseWithVPtr())
|
|
Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
|
|
Address VBPtr = CGF.Builder.CreateConstInBoundsByteGEP(This, Offs);
|
|
llvm::Value *GVPtr =
|
|
CGF.Builder.CreateConstInBoundsGEP2_32(GV->getValueType(), GV, 0, 0);
|
|
VBPtr = CGF.Builder.CreateElementBitCast(VBPtr, GVPtr->getType(),
|
|
"vbptr." + VBT->ObjectWithVPtr->getName());
|
|
CGF.Builder.CreateStore(GVPtr, VBPtr);
|
|
}
|
|
}
|
|
|
|
CGCXXABI::AddedStructorArgCounts
|
|
MicrosoftCXXABI::buildStructorSignature(GlobalDecl GD,
|
|
SmallVectorImpl<CanQualType> &ArgTys) {
|
|
AddedStructorArgCounts Added;
|
|
// TODO: 'for base' flag
|
|
if (isa<CXXDestructorDecl>(GD.getDecl()) &&
|
|
GD.getDtorType() == Dtor_Deleting) {
|
|
// The scalar deleting destructor takes an implicit int parameter.
|
|
ArgTys.push_back(getContext().IntTy);
|
|
++Added.Suffix;
|
|
}
|
|
auto *CD = dyn_cast<CXXConstructorDecl>(GD.getDecl());
|
|
if (!CD)
|
|
return Added;
|
|
|
|
// All parameters are already in place except is_most_derived, which goes
|
|
// after 'this' if it's variadic and last if it's not.
|
|
|
|
const CXXRecordDecl *Class = CD->getParent();
|
|
const FunctionProtoType *FPT = CD->getType()->castAs<FunctionProtoType>();
|
|
if (Class->getNumVBases()) {
|
|
if (FPT->isVariadic()) {
|
|
ArgTys.insert(ArgTys.begin() + 1, getContext().IntTy);
|
|
++Added.Prefix;
|
|
} else {
|
|
ArgTys.push_back(getContext().IntTy);
|
|
++Added.Suffix;
|
|
}
|
|
}
|
|
|
|
return Added;
|
|
}
|
|
|
|
void MicrosoftCXXABI::setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
|
|
const CXXDestructorDecl *Dtor,
|
|
CXXDtorType DT) const {
|
|
// Deleting destructor variants are never imported or exported. Give them the
|
|
// default storage class.
|
|
if (DT == Dtor_Deleting) {
|
|
GV->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
|
|
} else {
|
|
const NamedDecl *ND = Dtor;
|
|
CGM.setDLLImportDLLExport(GV, ND);
|
|
}
|
|
}
|
|
|
|
llvm::GlobalValue::LinkageTypes MicrosoftCXXABI::getCXXDestructorLinkage(
|
|
GVALinkage Linkage, const CXXDestructorDecl *Dtor, CXXDtorType DT) const {
|
|
// Internal things are always internal, regardless of attributes. After this,
|
|
// we know the thunk is externally visible.
|
|
if (Linkage == GVA_Internal)
|
|
return llvm::GlobalValue::InternalLinkage;
|
|
|
|
switch (DT) {
|
|
case Dtor_Base:
|
|
// The base destructor most closely tracks the user-declared constructor, so
|
|
// we delegate back to the normal declarator case.
|
|
return CGM.getLLVMLinkageForDeclarator(Dtor, Linkage,
|
|
/*IsConstantVariable=*/false);
|
|
case Dtor_Complete:
|
|
// The complete destructor is like an inline function, but it may be
|
|
// imported and therefore must be exported as well. This requires changing
|
|
// the linkage if a DLL attribute is present.
|
|
if (Dtor->hasAttr<DLLExportAttr>())
|
|
return llvm::GlobalValue::WeakODRLinkage;
|
|
if (Dtor->hasAttr<DLLImportAttr>())
|
|
return llvm::GlobalValue::AvailableExternallyLinkage;
|
|
return llvm::GlobalValue::LinkOnceODRLinkage;
|
|
case Dtor_Deleting:
|
|
// Deleting destructors are like inline functions. They have vague linkage
|
|
// and are emitted everywhere they are used. They are internal if the class
|
|
// is internal.
|
|
return llvm::GlobalValue::LinkOnceODRLinkage;
|
|
case Dtor_Comdat:
|
|
llvm_unreachable("MS C++ ABI does not support comdat dtors");
|
|
}
|
|
llvm_unreachable("invalid dtor type");
|
|
}
|
|
|
|
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));
|
|
|
|
// If the class is dllexported, emit the complete (vbase) destructor wherever
|
|
// the base dtor is emitted.
|
|
// FIXME: To match MSVC, this should only be done when the class is exported
|
|
// with -fdllexport-inlines enabled.
|
|
if (D->getParent()->getNumVBases() > 0 && D->hasAttr<DLLExportAttr>())
|
|
CGM.EmitGlobal(GlobalDecl(D, Dtor_Complete));
|
|
}
|
|
|
|
CharUnits
|
|
MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
|
|
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
|
|
|
|
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 CharUnits();
|
|
|
|
// There's no Dtor_Base in vftable but it shares the this adjustment with
|
|
// the deleting one, so look it up instead.
|
|
GD = GlobalDecl(DD, Dtor_Deleting);
|
|
}
|
|
|
|
MethodVFTableLocation ML =
|
|
CGM.getMicrosoftVTableContext().getMethodVFTableLocation(GD);
|
|
CharUnits Adjustment = ML.VFPtrOffset;
|
|
|
|
// Normal virtual instance methods need to adjust from the vfptr that first
|
|
// defined the virtual method to the virtual base subobject, but destructors
|
|
// do not. The vector deleting destructor thunk applies this adjustment for
|
|
// us if necessary.
|
|
if (isa<CXXDestructorDecl>(MD))
|
|
Adjustment = CharUnits::Zero();
|
|
|
|
if (ML.VBase) {
|
|
const ASTRecordLayout &DerivedLayout =
|
|
getContext().getASTRecordLayout(MD->getParent());
|
|
Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
|
|
}
|
|
|
|
return Adjustment;
|
|
}
|
|
|
|
Address MicrosoftCXXABI::adjustThisArgumentForVirtualFunctionCall(
|
|
CodeGenFunction &CGF, GlobalDecl GD, Address This,
|
|
bool VirtualCall) {
|
|
if (!VirtualCall) {
|
|
// If the call of a virtual function is not virtual, we just have to
|
|
// compensate for the adjustment the virtual function does in its prologue.
|
|
CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
|
|
if (Adjustment.isZero())
|
|
return This;
|
|
|
|
This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
|
|
assert(Adjustment.isPositive());
|
|
return CGF.Builder.CreateConstByteGEP(This, Adjustment);
|
|
}
|
|
|
|
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
|
|
|
|
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);
|
|
}
|
|
MethodVFTableLocation ML =
|
|
CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
|
|
|
|
CharUnits StaticOffset = ML.VFPtrOffset;
|
|
|
|
// Base destructors expect 'this' to point to the beginning of the base
|
|
// subobject, not the first vfptr that happens to contain the virtual dtor.
|
|
// However, we still need to apply the virtual base adjustment.
|
|
if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
|
|
StaticOffset = CharUnits::Zero();
|
|
|
|
Address Result = This;
|
|
if (ML.VBase) {
|
|
Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
|
|
|
|
const CXXRecordDecl *Derived = MD->getParent();
|
|
const CXXRecordDecl *VBase = ML.VBase;
|
|
llvm::Value *VBaseOffset =
|
|
GetVirtualBaseClassOffset(CGF, Result, Derived, VBase);
|
|
llvm::Value *VBasePtr =
|
|
CGF.Builder.CreateInBoundsGEP(Result.getPointer(), VBaseOffset);
|
|
CharUnits VBaseAlign =
|
|
CGF.CGM.getVBaseAlignment(Result.getAlignment(), Derived, VBase);
|
|
Result = Address(VBasePtr, VBaseAlign);
|
|
}
|
|
if (!StaticOffset.isZero()) {
|
|
assert(StaticOffset.isPositive());
|
|
Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
|
|
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.
|
|
Result = CGF.Builder.CreateConstByteGEP(Result, StaticOffset);
|
|
} else {
|
|
Result = CGF.Builder.CreateConstInBoundsByteGEP(Result, StaticOffset);
|
|
}
|
|
}
|
|
return Result;
|
|
}
|
|
|
|
void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
|
|
QualType &ResTy,
|
|
FunctionArgList &Params) {
|
|
ASTContext &Context = getContext();
|
|
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
|
|
assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
|
|
if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
|
|
auto *IsMostDerived = ImplicitParamDecl::Create(
|
|
Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
|
|
&Context.Idents.get("is_most_derived"), Context.IntTy,
|
|
ImplicitParamDecl::Other);
|
|
// The 'most_derived' parameter goes second if the ctor is variadic and last
|
|
// if it's not. Dtors can't be variadic.
|
|
const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
|
|
if (FPT->isVariadic())
|
|
Params.insert(Params.begin() + 1, IsMostDerived);
|
|
else
|
|
Params.push_back(IsMostDerived);
|
|
getStructorImplicitParamDecl(CGF) = IsMostDerived;
|
|
} else if (isDeletingDtor(CGF.CurGD)) {
|
|
auto *ShouldDelete = ImplicitParamDecl::Create(
|
|
Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
|
|
&Context.Idents.get("should_call_delete"), Context.IntTy,
|
|
ImplicitParamDecl::Other);
|
|
Params.push_back(ShouldDelete);
|
|
getStructorImplicitParamDecl(CGF) = ShouldDelete;
|
|
}
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
|
|
// Naked functions have no prolog.
|
|
if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
|
|
return;
|
|
|
|
// Overridden virtual methods of non-primary bases need to adjust the incoming
|
|
// 'this' pointer in the prologue. In this hierarchy, C::b will subtract
|
|
// sizeof(void*) to adjust from B* to C*:
|
|
// struct A { virtual void a(); };
|
|
// struct B { virtual void b(); };
|
|
// struct C : A, B { virtual void b(); };
|
|
//
|
|
// Leave the value stored in the 'this' alloca unadjusted, so that the
|
|
// debugger sees the unadjusted value. Microsoft debuggers require this, and
|
|
// will apply the ThisAdjustment in the method type information.
|
|
// FIXME: Do something better for DWARF debuggers, which won't expect this,
|
|
// without making our codegen depend on debug info settings.
|
|
llvm::Value *This = loadIncomingCXXThis(CGF);
|
|
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
|
|
if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
|
|
CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
|
|
if (!Adjustment.isZero()) {
|
|
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(CGF.Int8Ty, This,
|
|
-Adjustment.getQuantity());
|
|
This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted");
|
|
}
|
|
}
|
|
setCXXABIThisValue(CGF, This);
|
|
|
|
// 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);
|
|
else if (hasMostDerivedReturn(CGF.CurGD))
|
|
CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)),
|
|
CGF.ReturnValue);
|
|
|
|
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");
|
|
}
|
|
}
|
|
|
|
CGCXXABI::AddedStructorArgs MicrosoftCXXABI::getImplicitConstructorArgs(
|
|
CodeGenFunction &CGF, const CXXConstructorDecl *D, CXXCtorType Type,
|
|
bool ForVirtualBase, bool Delegating) {
|
|
assert(Type == Ctor_Complete || Type == Ctor_Base);
|
|
|
|
// Check if we need a 'most_derived' parameter.
|
|
if (!D->getParent()->getNumVBases())
|
|
return AddedStructorArgs{};
|
|
|
|
// Add the 'most_derived' argument second if we are variadic or last if not.
|
|
const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
|
|
llvm::Value *MostDerivedArg;
|
|
if (Delegating) {
|
|
MostDerivedArg = getStructorImplicitParamValue(CGF);
|
|
} else {
|
|
MostDerivedArg = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
|
|
}
|
|
if (FPT->isVariadic()) {
|
|
return AddedStructorArgs::prefix({{MostDerivedArg, getContext().IntTy}});
|
|
}
|
|
return AddedStructorArgs::suffix({{MostDerivedArg, getContext().IntTy}});
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::getCXXDestructorImplicitParam(
|
|
CodeGenFunction &CGF, const CXXDestructorDecl *DD, CXXDtorType Type,
|
|
bool ForVirtualBase, bool Delegating) {
|
|
return nullptr;
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
|
|
const CXXDestructorDecl *DD,
|
|
CXXDtorType Type, bool ForVirtualBase,
|
|
bool Delegating, Address This,
|
|
QualType ThisTy) {
|
|
// Use the base destructor variant in place of the complete destructor variant
|
|
// if the class has no virtual bases. This effectively implements some of the
|
|
// -mconstructor-aliases optimization, but as part of the MS C++ ABI.
|
|
if (Type == Dtor_Complete && DD->getParent()->getNumVBases() == 0)
|
|
Type = Dtor_Base;
|
|
|
|
GlobalDecl GD(DD, Type);
|
|
CGCallee Callee = CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD), GD);
|
|
|
|
if (DD->isVirtual()) {
|
|
assert(Type != CXXDtorType::Dtor_Deleting &&
|
|
"The deleting destructor should only be called via a virtual call");
|
|
This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
|
|
This, false);
|
|
}
|
|
|
|
llvm::BasicBlock *BaseDtorEndBB = nullptr;
|
|
if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
|
|
BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
|
|
}
|
|
|
|
llvm::Value *Implicit =
|
|
getCXXDestructorImplicitParam(CGF, DD, Type, ForVirtualBase,
|
|
Delegating); // = nullptr
|
|
CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
|
|
/*ImplicitParam=*/Implicit,
|
|
/*ImplicitParamTy=*/QualType(), nullptr);
|
|
if (BaseDtorEndBB) {
|
|
// Complete object handler should continue to be the remaining
|
|
CGF.Builder.CreateBr(BaseDtorEndBB);
|
|
CGF.EmitBlock(BaseDtorEndBB);
|
|
}
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
|
|
const CXXRecordDecl *RD,
|
|
llvm::GlobalVariable *VTable) {
|
|
if (!CGM.getCodeGenOpts().LTOUnit)
|
|
return;
|
|
|
|
// TODO: Should VirtualFunctionElimination also be supported here?
|
|
// See similar handling in CodeGenModule::EmitVTableTypeMetadata.
|
|
if (CGM.getCodeGenOpts().WholeProgramVTables) {
|
|
llvm::DenseSet<const CXXRecordDecl *> Visited;
|
|
llvm::GlobalObject::VCallVisibility TypeVis =
|
|
CGM.GetVCallVisibilityLevel(RD, Visited);
|
|
if (TypeVis != llvm::GlobalObject::VCallVisibilityPublic)
|
|
VTable->setVCallVisibilityMetadata(TypeVis);
|
|
}
|
|
|
|
// The location of the first virtual function pointer in the virtual table,
|
|
// aka the "address point" on Itanium. This is at offset 0 if RTTI is
|
|
// disabled, or sizeof(void*) if RTTI is enabled.
|
|
CharUnits AddressPoint =
|
|
getContext().getLangOpts().RTTIData
|
|
? getContext().toCharUnitsFromBits(
|
|
getContext().getTargetInfo().getPointerWidth(0))
|
|
: CharUnits::Zero();
|
|
|
|
if (Info.PathToIntroducingObject.empty()) {
|
|
CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
|
|
return;
|
|
}
|
|
|
|
// Add a bitset entry for the least derived base belonging to this vftable.
|
|
CGM.AddVTableTypeMetadata(VTable, AddressPoint,
|
|
Info.PathToIntroducingObject.back());
|
|
|
|
// Add a bitset entry for each derived class that is laid out at the same
|
|
// offset as the least derived base.
|
|
for (unsigned I = Info.PathToIntroducingObject.size() - 1; I != 0; --I) {
|
|
const CXXRecordDecl *DerivedRD = Info.PathToIntroducingObject[I - 1];
|
|
const CXXRecordDecl *BaseRD = Info.PathToIntroducingObject[I];
|
|
|
|
const ASTRecordLayout &Layout =
|
|
getContext().getASTRecordLayout(DerivedRD);
|
|
CharUnits Offset;
|
|
auto VBI = Layout.getVBaseOffsetsMap().find(BaseRD);
|
|
if (VBI == Layout.getVBaseOffsetsMap().end())
|
|
Offset = Layout.getBaseClassOffset(BaseRD);
|
|
else
|
|
Offset = VBI->second.VBaseOffset;
|
|
if (!Offset.isZero())
|
|
return;
|
|
CGM.AddVTableTypeMetadata(VTable, AddressPoint, DerivedRD);
|
|
}
|
|
|
|
// Finally do the same for the most derived class.
|
|
if (Info.FullOffsetInMDC.isZero())
|
|
CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
|
|
const CXXRecordDecl *RD) {
|
|
MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
|
|
const VPtrInfoVector &VFPtrs = VFTContext.getVFPtrOffsets(RD);
|
|
|
|
for (const std::unique_ptr<VPtrInfo>& Info : VFPtrs) {
|
|
llvm::GlobalVariable *VTable = getAddrOfVTable(RD, Info->FullOffsetInMDC);
|
|
if (VTable->hasInitializer())
|
|
continue;
|
|
|
|
const VTableLayout &VTLayout =
|
|
VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
|
|
|
|
llvm::Constant *RTTI = nullptr;
|
|
if (any_of(VTLayout.vtable_components(),
|
|
[](const VTableComponent &VTC) { return VTC.isRTTIKind(); }))
|
|
RTTI = getMSCompleteObjectLocator(RD, *Info);
|
|
|
|
ConstantInitBuilder builder(CGM);
|
|
auto components = builder.beginStruct();
|
|
CGVT.createVTableInitializer(components, VTLayout, RTTI,
|
|
VTable->hasLocalLinkage());
|
|
components.finishAndSetAsInitializer(VTable);
|
|
|
|
emitVTableTypeMetadata(*Info, RD, VTable);
|
|
}
|
|
}
|
|
|
|
bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
|
|
CodeGenFunction &CGF, CodeGenFunction::VPtr Vptr) {
|
|
return Vptr.NearestVBase != nullptr;
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
|
|
CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
|
|
const CXXRecordDecl *NearestVBase) {
|
|
llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
|
|
if (!VTableAddressPoint) {
|
|
assert(Base.getBase()->getNumVBases() &&
|
|
!getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
|
|
}
|
|
return VTableAddressPoint;
|
|
}
|
|
|
|
static void mangleVFTableName(MicrosoftMangleContext &MangleContext,
|
|
const CXXRecordDecl *RD, const VPtrInfo &VFPtr,
|
|
SmallString<256> &Name) {
|
|
llvm::raw_svector_ostream Out(Name);
|
|
MangleContext.mangleCXXVFTable(RD, VFPtr.MangledPath, Out);
|
|
}
|
|
|
|
llvm::Constant *
|
|
MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
|
|
const CXXRecordDecl *VTableClass) {
|
|
(void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
|
|
VFTableIdTy ID(VTableClass, Base.getBaseOffset());
|
|
return VFTablesMap[ID];
|
|
}
|
|
|
|
llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
|
|
BaseSubobject Base, const CXXRecordDecl *VTableClass) {
|
|
llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
|
|
assert(VFTable && "Couldn't find a vftable for the given base?");
|
|
return VFTable;
|
|
}
|
|
|
|
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);
|
|
VTablesMapTy::iterator I;
|
|
bool Inserted;
|
|
std::tie(I, Inserted) = VTablesMap.insert(std::make_pair(ID, nullptr));
|
|
if (!Inserted)
|
|
return I->second;
|
|
|
|
llvm::GlobalVariable *&VTable = I->second;
|
|
|
|
MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
|
|
const VPtrInfoVector &VFPtrs = VTContext.getVFPtrOffsets(RD);
|
|
|
|
if (DeferredVFTables.insert(RD).second) {
|
|
// We haven't processed this record type before.
|
|
// Queue up this vtable 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()).second)
|
|
llvm_unreachable("Already saw this mangling before?");
|
|
}
|
|
#endif
|
|
}
|
|
|
|
const std::unique_ptr<VPtrInfo> *VFPtrI = std::find_if(
|
|
VFPtrs.begin(), VFPtrs.end(), [&](const std::unique_ptr<VPtrInfo>& VPI) {
|
|
return VPI->FullOffsetInMDC == VPtrOffset;
|
|
});
|
|
if (VFPtrI == VFPtrs.end()) {
|
|
VFTablesMap[ID] = nullptr;
|
|
return nullptr;
|
|
}
|
|
const std::unique_ptr<VPtrInfo> &VFPtr = *VFPtrI;
|
|
|
|
SmallString<256> VFTableName;
|
|
mangleVFTableName(getMangleContext(), RD, *VFPtr, VFTableName);
|
|
|
|
// Classes marked __declspec(dllimport) need vftables generated on the
|
|
// import-side in order to support features like constexpr. No other
|
|
// translation unit relies on the emission of the local vftable, translation
|
|
// units are expected to generate them as needed.
|
|
//
|
|
// Because of this unique behavior, we maintain this logic here instead of
|
|
// getVTableLinkage.
|
|
llvm::GlobalValue::LinkageTypes VFTableLinkage =
|
|
RD->hasAttr<DLLImportAttr>() ? llvm::GlobalValue::LinkOnceODRLinkage
|
|
: CGM.getVTableLinkage(RD);
|
|
bool VFTableComesFromAnotherTU =
|
|
llvm::GlobalValue::isAvailableExternallyLinkage(VFTableLinkage) ||
|
|
llvm::GlobalValue::isExternalLinkage(VFTableLinkage);
|
|
bool VTableAliasIsRequred =
|
|
!VFTableComesFromAnotherTU && getContext().getLangOpts().RTTIData;
|
|
|
|
if (llvm::GlobalValue *VFTable =
|
|
CGM.getModule().getNamedGlobal(VFTableName)) {
|
|
VFTablesMap[ID] = VFTable;
|
|
VTable = VTableAliasIsRequred
|
|
? cast<llvm::GlobalVariable>(
|
|
cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
|
|
: cast<llvm::GlobalVariable>(VFTable);
|
|
return VTable;
|
|
}
|
|
|
|
const VTableLayout &VTLayout =
|
|
VTContext.getVFTableLayout(RD, VFPtr->FullOffsetInMDC);
|
|
llvm::GlobalValue::LinkageTypes VTableLinkage =
|
|
VTableAliasIsRequred ? llvm::GlobalValue::PrivateLinkage : VFTableLinkage;
|
|
|
|
StringRef VTableName = VTableAliasIsRequred ? StringRef() : VFTableName.str();
|
|
|
|
llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
|
|
|
|
// Create a backing variable for the contents of VTable. The VTable may
|
|
// or may not include space for a pointer to RTTI data.
|
|
llvm::GlobalValue *VFTable;
|
|
VTable = new llvm::GlobalVariable(CGM.getModule(), VTableType,
|
|
/*isConstant=*/true, VTableLinkage,
|
|
/*Initializer=*/nullptr, VTableName);
|
|
VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
|
|
llvm::Comdat *C = nullptr;
|
|
if (!VFTableComesFromAnotherTU &&
|
|
(llvm::GlobalValue::isWeakForLinker(VFTableLinkage) ||
|
|
(llvm::GlobalValue::isLocalLinkage(VFTableLinkage) &&
|
|
VTableAliasIsRequred)))
|
|
C = CGM.getModule().getOrInsertComdat(VFTableName.str());
|
|
|
|
// Only insert a pointer into the VFTable for RTTI data if we are not
|
|
// importing it. We never reference the RTTI data directly so there is no
|
|
// need to make room for it.
|
|
if (VTableAliasIsRequred) {
|
|
llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.Int32Ty, 0),
|
|
llvm::ConstantInt::get(CGM.Int32Ty, 0),
|
|
llvm::ConstantInt::get(CGM.Int32Ty, 1)};
|
|
// Create a GEP which points just after the first entry in the VFTable,
|
|
// this should be the location of the first virtual method.
|
|
llvm::Constant *VTableGEP = llvm::ConstantExpr::getInBoundsGetElementPtr(
|
|
VTable->getValueType(), VTable, GEPIndices);
|
|
if (llvm::GlobalValue::isWeakForLinker(VFTableLinkage)) {
|
|
VFTableLinkage = llvm::GlobalValue::ExternalLinkage;
|
|
if (C)
|
|
C->setSelectionKind(llvm::Comdat::Largest);
|
|
}
|
|
VFTable = llvm::GlobalAlias::create(CGM.Int8PtrTy,
|
|
/*AddressSpace=*/0, VFTableLinkage,
|
|
VFTableName.str(), VTableGEP,
|
|
&CGM.getModule());
|
|
VFTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
} else {
|
|
// We don't need a GlobalAlias to be a symbol for the VTable if we won't
|
|
// be referencing any RTTI data.
|
|
// The GlobalVariable will end up being an appropriate definition of the
|
|
// VFTable.
|
|
VFTable = VTable;
|
|
}
|
|
if (C)
|
|
VTable->setComdat(C);
|
|
|
|
if (RD->hasAttr<DLLExportAttr>())
|
|
VFTable->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
|
|
|
|
VFTablesMap[ID] = VFTable;
|
|
return VTable;
|
|
}
|
|
|
|
CGCallee MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
|
|
GlobalDecl GD,
|
|
Address This,
|
|
llvm::Type *Ty,
|
|
SourceLocation Loc) {
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
|
|
Ty = Ty->getPointerTo()->getPointerTo();
|
|
Address VPtr =
|
|
adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
|
|
|
|
auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
|
|
llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty, MethodDecl->getParent());
|
|
|
|
MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
|
|
MethodVFTableLocation ML = VFTContext.getMethodVFTableLocation(GD);
|
|
|
|
// Compute the identity of the most derived class whose virtual table is
|
|
// located at the MethodVFTableLocation ML.
|
|
auto getObjectWithVPtr = [&] {
|
|
return llvm::find_if(VFTContext.getVFPtrOffsets(
|
|
ML.VBase ? ML.VBase : MethodDecl->getParent()),
|
|
[&](const std::unique_ptr<VPtrInfo> &Info) {
|
|
return Info->FullOffsetInMDC == ML.VFPtrOffset;
|
|
})
|
|
->get()
|
|
->ObjectWithVPtr;
|
|
};
|
|
|
|
llvm::Value *VFunc;
|
|
if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
|
|
VFunc = CGF.EmitVTableTypeCheckedLoad(
|
|
getObjectWithVPtr(), VTable,
|
|
ML.Index * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
|
|
} else {
|
|
if (CGM.getCodeGenOpts().PrepareForLTO)
|
|
CGF.EmitTypeMetadataCodeForVCall(getObjectWithVPtr(), VTable, Loc);
|
|
|
|
llvm::Value *VFuncPtr =
|
|
Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
|
|
VFunc = Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
|
|
}
|
|
|
|
CGCallee Callee(GD, VFunc);
|
|
return Callee;
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
|
|
CodeGenFunction &CGF, const CXXDestructorDecl *Dtor, CXXDtorType DtorType,
|
|
Address This, DeleteOrMemberCallExpr E) {
|
|
auto *CE = E.dyn_cast<const CXXMemberCallExpr *>();
|
|
auto *D = E.dyn_cast<const CXXDeleteExpr *>();
|
|
assert((CE != nullptr) ^ (D != nullptr));
|
|
assert(CE == nullptr || CE->arg_begin() == CE->arg_end());
|
|
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().arrangeCXXStructorDeclaration(GD);
|
|
llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
|
|
CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
|
|
|
|
ASTContext &Context = getContext();
|
|
llvm::Value *ImplicitParam = llvm::ConstantInt::get(
|
|
llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
|
|
DtorType == Dtor_Deleting);
|
|
|
|
QualType ThisTy;
|
|
if (CE) {
|
|
ThisTy = CE->getObjectType();
|
|
} else {
|
|
ThisTy = D->getDestroyedType();
|
|
}
|
|
|
|
This = adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
|
|
RValue RV = CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
|
|
ImplicitParam, Context.IntTy, CE);
|
|
return RV.getScalarVal();
|
|
}
|
|
|
|
const VBTableGlobals &
|
|
MicrosoftCXXABI::enumerateVBTables(const CXXRecordDecl *RD) {
|
|
// At this layer, we can key the cache off of a single class, which is much
|
|
// easier than caching each vbtable individually.
|
|
llvm::DenseMap<const CXXRecordDecl*, VBTableGlobals>::iterator Entry;
|
|
bool Added;
|
|
std::tie(Entry, Added) =
|
|
VBTablesMap.insert(std::make_pair(RD, VBTableGlobals()));
|
|
VBTableGlobals &VBGlobals = Entry->second;
|
|
if (!Added)
|
|
return VBGlobals;
|
|
|
|
MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
|
|
VBGlobals.VBTables = &Context.enumerateVBTables(RD);
|
|
|
|
// Cache the globals for all vbtables so we don't have to recompute the
|
|
// mangled names.
|
|
llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
|
|
for (VPtrInfoVector::const_iterator I = VBGlobals.VBTables->begin(),
|
|
E = VBGlobals.VBTables->end();
|
|
I != E; ++I) {
|
|
VBGlobals.Globals.push_back(getAddrOfVBTable(**I, RD, Linkage));
|
|
}
|
|
|
|
return VBGlobals;
|
|
}
|
|
|
|
llvm::Function *
|
|
MicrosoftCXXABI::EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
|
|
const MethodVFTableLocation &ML) {
|
|
assert(!isa<CXXConstructorDecl>(MD) && !isa<CXXDestructorDecl>(MD) &&
|
|
"can't form pointers to ctors or virtual dtors");
|
|
|
|
// Calculate the mangled name.
|
|
SmallString<256> ThunkName;
|
|
llvm::raw_svector_ostream Out(ThunkName);
|
|
getMangleContext().mangleVirtualMemPtrThunk(MD, ML, Out);
|
|
|
|
// 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().arrangeUnprototypedMustTailThunk(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);
|
|
if (MD->isExternallyVisible())
|
|
ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
|
|
|
|
CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn);
|
|
CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn);
|
|
|
|
// Add the "thunk" attribute so that LLVM knows that the return type is
|
|
// meaningless. These thunks can be used to call functions with differing
|
|
// return types, and the caller is required to cast the prototype
|
|
// appropriately to extract the correct value.
|
|
ThunkFn->addFnAttr("thunk");
|
|
|
|
// These thunks can be compared, so they are not unnamed.
|
|
ThunkFn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
|
|
|
|
// Start codegen.
|
|
CodeGenFunction CGF(CGM);
|
|
CGF.CurGD = GlobalDecl(MD);
|
|
CGF.CurFuncIsThunk = true;
|
|
|
|
// Build FunctionArgs, but only include the implicit 'this' parameter
|
|
// declaration.
|
|
FunctionArgList FunctionArgs;
|
|
buildThisParam(CGF, FunctionArgs);
|
|
|
|
// Start defining the function.
|
|
CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
|
|
FunctionArgs, MD->getLocation(), SourceLocation());
|
|
setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
|
|
|
|
// Load the vfptr and then callee from the vftable. The callee should have
|
|
// adjusted 'this' so that the vfptr is at offset zero.
|
|
llvm::Value *VTable = CGF.GetVTablePtr(
|
|
getThisAddress(CGF), ThunkTy->getPointerTo()->getPointerTo(), MD->getParent());
|
|
|
|
llvm::Value *VFuncPtr =
|
|
CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
|
|
llvm::Value *Callee =
|
|
CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
|
|
|
|
CGF.EmitMustTailThunk(MD, getThisValue(CGF), {ThunkTy, Callee});
|
|
|
|
return ThunkFn;
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
|
|
const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
|
|
for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
|
|
const std::unique_ptr<VPtrInfo>& VBT = (*VBGlobals.VBTables)[I];
|
|
llvm::GlobalVariable *GV = VBGlobals.Globals[I];
|
|
if (GV->isDeclaration())
|
|
emitVBTableDefinition(*VBT, RD, GV);
|
|
}
|
|
}
|
|
|
|
llvm::GlobalVariable *
|
|
MicrosoftCXXABI::getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
|
|
llvm::GlobalVariable::LinkageTypes Linkage) {
|
|
SmallString<256> OutName;
|
|
llvm::raw_svector_ostream Out(OutName);
|
|
getMangleContext().mangleCXXVBTable(RD, VBT.MangledPath, Out);
|
|
StringRef Name = OutName.str();
|
|
|
|
llvm::ArrayType *VBTableType =
|
|
llvm::ArrayType::get(CGM.IntTy, 1 + VBT.ObjectWithVPtr->getNumVBases());
|
|
|
|
assert(!CGM.getModule().getNamedGlobal(Name) &&
|
|
"vbtable with this name already exists: mangling bug?");
|
|
CharUnits Alignment =
|
|
CGM.getContext().getTypeAlignInChars(CGM.getContext().IntTy);
|
|
llvm::GlobalVariable *GV = CGM.CreateOrReplaceCXXRuntimeVariable(
|
|
Name, VBTableType, Linkage, Alignment.getQuantity());
|
|
GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
|
|
if (RD->hasAttr<DLLImportAttr>())
|
|
GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
|
|
else if (RD->hasAttr<DLLExportAttr>())
|
|
GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
|
|
|
|
if (!GV->hasExternalLinkage())
|
|
emitVBTableDefinition(VBT, RD, GV);
|
|
|
|
return GV;
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitVBTableDefinition(const VPtrInfo &VBT,
|
|
const CXXRecordDecl *RD,
|
|
llvm::GlobalVariable *GV) const {
|
|
const CXXRecordDecl *ObjectWithVPtr = VBT.ObjectWithVPtr;
|
|
|
|
assert(RD->getNumVBases() && ObjectWithVPtr->getNumVBases() &&
|
|
"should only emit vbtables for classes with vbtables");
|
|
|
|
const ASTRecordLayout &BaseLayout =
|
|
getContext().getASTRecordLayout(VBT.IntroducingObject);
|
|
const ASTRecordLayout &DerivedLayout = getContext().getASTRecordLayout(RD);
|
|
|
|
SmallVector<llvm::Constant *, 4> Offsets(1 + ObjectWithVPtr->getNumVBases(),
|
|
nullptr);
|
|
|
|
// The offset from ObjectWithVPtr's vbptr to itself always leads.
|
|
CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
|
|
Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
|
|
|
|
MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
|
|
for (const auto &I : ObjectWithVPtr->vbases()) {
|
|
const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
|
|
CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
|
|
assert(!Offset.isNegative());
|
|
|
|
// Make it relative to the subobject vbptr.
|
|
CharUnits CompleteVBPtrOffset = VBT.NonVirtualOffset + VBPtrOffset;
|
|
if (VBT.getVBaseWithVPtr())
|
|
CompleteVBPtrOffset +=
|
|
DerivedLayout.getVBaseClassOffset(VBT.getVBaseWithVPtr());
|
|
Offset -= CompleteVBPtrOffset;
|
|
|
|
unsigned VBIndex = Context.getVBTableIndex(ObjectWithVPtr, VBase);
|
|
assert(Offsets[VBIndex] == nullptr && "The same vbindex seen twice?");
|
|
Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
|
|
}
|
|
|
|
assert(Offsets.size() ==
|
|
cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
|
|
->getElementType())->getNumElements());
|
|
llvm::ArrayType *VBTableType =
|
|
llvm::ArrayType::get(CGM.IntTy, Offsets.size());
|
|
llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
|
|
GV->setInitializer(Init);
|
|
|
|
if (RD->hasAttr<DLLImportAttr>())
|
|
GV->setLinkage(llvm::GlobalVariable::AvailableExternallyLinkage);
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF,
|
|
Address This,
|
|
const ThisAdjustment &TA) {
|
|
if (TA.isEmpty())
|
|
return This.getPointer();
|
|
|
|
This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
|
|
|
|
llvm::Value *V;
|
|
if (TA.Virtual.isEmpty()) {
|
|
V = This.getPointer();
|
|
} else {
|
|
assert(TA.Virtual.Microsoft.VtordispOffset < 0);
|
|
// Adjust the this argument based on the vtordisp value.
|
|
Address VtorDispPtr =
|
|
CGF.Builder.CreateConstInBoundsByteGEP(This,
|
|
CharUnits::fromQuantity(TA.Virtual.Microsoft.VtordispOffset));
|
|
VtorDispPtr = CGF.Builder.CreateElementBitCast(VtorDispPtr, CGF.Int32Ty);
|
|
llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp");
|
|
V = CGF.Builder.CreateGEP(This.getPointer(),
|
|
CGF.Builder.CreateNeg(VtorDisp));
|
|
|
|
// Unfortunately, having applied the vtordisp means that we no
|
|
// longer really have a known alignment for the vbptr step.
|
|
// We'll assume the vbptr is pointer-aligned.
|
|
|
|
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, Address(V, CGF.getPointerAlign()),
|
|
-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, Address Ret,
|
|
const ReturnAdjustment &RA) {
|
|
if (RA.isEmpty())
|
|
return Ret.getPointer();
|
|
|
|
auto OrigTy = Ret.getType();
|
|
Ret = CGF.Builder.CreateElementBitCast(Ret, CGF.Int8Ty);
|
|
|
|
llvm::Value *V = Ret.getPointer();
|
|
if (RA.Virtual.Microsoft.VBIndex) {
|
|
assert(RA.Virtual.Microsoft.VBIndex > 0);
|
|
int32_t IntSize = CGF.getIntSize().getQuantity();
|
|
llvm::Value *VBPtr;
|
|
llvm::Value *VBaseOffset =
|
|
GetVBaseOffsetFromVBPtr(CGF, Ret, RA.Virtual.Microsoft.VBPtrOffset,
|
|
IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr);
|
|
V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
|
|
}
|
|
|
|
if (RA.NonVirtual)
|
|
V = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, V, RA.NonVirtual);
|
|
|
|
// Cast back to the original type.
|
|
return CGF.Builder.CreateBitCast(V, OrigTy);
|
|
}
|
|
|
|
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,
|
|
Address allocPtr,
|
|
CharUnits cookieSize) {
|
|
Address numElementsPtr =
|
|
CGF.Builder.CreateElementBitCast(allocPtr, CGF.SizeTy);
|
|
return CGF.Builder.CreateLoad(numElementsPtr);
|
|
}
|
|
|
|
Address MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
|
|
Address 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.
|
|
Address cookiePtr = newPtr;
|
|
|
|
// Write the number of elements into the appropriate slot.
|
|
Address numElementsPtr
|
|
= CGF.Builder.CreateElementBitCast(cookiePtr, CGF.SizeTy);
|
|
CGF.Builder.CreateStore(numElements, numElementsPtr);
|
|
|
|
// Finally, compute a pointer to the actual data buffer by skipping
|
|
// over the cookie completely.
|
|
return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
|
|
}
|
|
|
|
static void emitGlobalDtorWithTLRegDtor(CodeGenFunction &CGF, const VarDecl &VD,
|
|
llvm::FunctionCallee Dtor,
|
|
llvm::Constant *Addr) {
|
|
// Create a function which calls the destructor.
|
|
llvm::Constant *DtorStub = CGF.createAtExitStub(VD, Dtor, Addr);
|
|
|
|
// extern "C" int __tlregdtor(void (*f)(void));
|
|
llvm::FunctionType *TLRegDtorTy = llvm::FunctionType::get(
|
|
CGF.IntTy, DtorStub->getType(), /*isVarArg=*/false);
|
|
|
|
llvm::FunctionCallee TLRegDtor = CGF.CGM.CreateRuntimeFunction(
|
|
TLRegDtorTy, "__tlregdtor", llvm::AttributeList(), /*Local=*/true);
|
|
if (llvm::Function *TLRegDtorFn =
|
|
dyn_cast<llvm::Function>(TLRegDtor.getCallee()))
|
|
TLRegDtorFn->setDoesNotThrow();
|
|
|
|
CGF.EmitNounwindRuntimeCall(TLRegDtor, DtorStub);
|
|
}
|
|
|
|
void MicrosoftCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
|
|
llvm::FunctionCallee Dtor,
|
|
llvm::Constant *Addr) {
|
|
if (D.isNoDestroy(CGM.getContext()))
|
|
return;
|
|
|
|
if (D.getTLSKind())
|
|
return emitGlobalDtorWithTLRegDtor(CGF, D, Dtor, Addr);
|
|
|
|
// The default behavior is to use atexit.
|
|
CGF.registerGlobalDtorWithAtExit(D, Dtor, Addr);
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitThreadLocalInitFuncs(
|
|
CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
|
|
ArrayRef<llvm::Function *> CXXThreadLocalInits,
|
|
ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
|
|
if (CXXThreadLocalInits.empty())
|
|
return;
|
|
|
|
CGM.AppendLinkerOptions(CGM.getTarget().getTriple().getArch() ==
|
|
llvm::Triple::x86
|
|
? "/include:___dyn_tls_init@12"
|
|
: "/include:__dyn_tls_init");
|
|
|
|
// This will create a GV in the .CRT$XDU section. It will point to our
|
|
// initialization function. The CRT will call all of these function
|
|
// pointers at start-up time and, eventually, at thread-creation time.
|
|
auto AddToXDU = [&CGM](llvm::Function *InitFunc) {
|
|
llvm::GlobalVariable *InitFuncPtr = new llvm::GlobalVariable(
|
|
CGM.getModule(), InitFunc->getType(), /*isConstant=*/true,
|
|
llvm::GlobalVariable::InternalLinkage, InitFunc,
|
|
Twine(InitFunc->getName(), "$initializer$"));
|
|
InitFuncPtr->setSection(".CRT$XDU");
|
|
// This variable has discardable linkage, we have to add it to @llvm.used to
|
|
// ensure it won't get discarded.
|
|
CGM.addUsedGlobal(InitFuncPtr);
|
|
return InitFuncPtr;
|
|
};
|
|
|
|
std::vector<llvm::Function *> NonComdatInits;
|
|
for (size_t I = 0, E = CXXThreadLocalInitVars.size(); I != E; ++I) {
|
|
llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(
|
|
CGM.GetGlobalValue(CGM.getMangledName(CXXThreadLocalInitVars[I])));
|
|
llvm::Function *F = CXXThreadLocalInits[I];
|
|
|
|
// If the GV is already in a comdat group, then we have to join it.
|
|
if (llvm::Comdat *C = GV->getComdat())
|
|
AddToXDU(F)->setComdat(C);
|
|
else
|
|
NonComdatInits.push_back(F);
|
|
}
|
|
|
|
if (!NonComdatInits.empty()) {
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
|
|
llvm::Function *InitFunc = CGM.CreateGlobalInitOrCleanUpFunction(
|
|
FTy, "__tls_init", CGM.getTypes().arrangeNullaryFunction(),
|
|
SourceLocation(), /*TLS=*/true);
|
|
CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(InitFunc, NonComdatInits);
|
|
|
|
AddToXDU(InitFunc);
|
|
}
|
|
}
|
|
|
|
LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
|
|
const VarDecl *VD,
|
|
QualType LValType) {
|
|
CGF.CGM.ErrorUnsupported(VD, "thread wrappers");
|
|
return LValue();
|
|
}
|
|
|
|
static ConstantAddress getInitThreadEpochPtr(CodeGenModule &CGM) {
|
|
StringRef VarName("_Init_thread_epoch");
|
|
CharUnits Align = CGM.getIntAlign();
|
|
if (auto *GV = CGM.getModule().getNamedGlobal(VarName))
|
|
return ConstantAddress(GV, Align);
|
|
auto *GV = new llvm::GlobalVariable(
|
|
CGM.getModule(), CGM.IntTy,
|
|
/*isConstant=*/false, llvm::GlobalVariable::ExternalLinkage,
|
|
/*Initializer=*/nullptr, VarName,
|
|
/*InsertBefore=*/nullptr, llvm::GlobalVariable::GeneralDynamicTLSModel);
|
|
GV->setAlignment(Align.getAsAlign());
|
|
return ConstantAddress(GV, Align);
|
|
}
|
|
|
|
static llvm::FunctionCallee getInitThreadHeaderFn(CodeGenModule &CGM) {
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
|
|
CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
|
|
return CGM.CreateRuntimeFunction(
|
|
FTy, "_Init_thread_header",
|
|
llvm::AttributeList::get(CGM.getLLVMContext(),
|
|
llvm::AttributeList::FunctionIndex,
|
|
llvm::Attribute::NoUnwind),
|
|
/*Local=*/true);
|
|
}
|
|
|
|
static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM) {
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
|
|
CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
|
|
return CGM.CreateRuntimeFunction(
|
|
FTy, "_Init_thread_footer",
|
|
llvm::AttributeList::get(CGM.getLLVMContext(),
|
|
llvm::AttributeList::FunctionIndex,
|
|
llvm::Attribute::NoUnwind),
|
|
/*Local=*/true);
|
|
}
|
|
|
|
static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM) {
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
|
|
CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
|
|
return CGM.CreateRuntimeFunction(
|
|
FTy, "_Init_thread_abort",
|
|
llvm::AttributeList::get(CGM.getLLVMContext(),
|
|
llvm::AttributeList::FunctionIndex,
|
|
llvm::Attribute::NoUnwind),
|
|
/*Local=*/true);
|
|
}
|
|
|
|
namespace {
|
|
struct ResetGuardBit final : EHScopeStack::Cleanup {
|
|
Address Guard;
|
|
unsigned GuardNum;
|
|
ResetGuardBit(Address Guard, unsigned GuardNum)
|
|
: Guard(Guard), GuardNum(GuardNum) {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
// Reset the bit in the mask so that the static variable may be
|
|
// reinitialized.
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
llvm::LoadInst *LI = Builder.CreateLoad(Guard);
|
|
llvm::ConstantInt *Mask =
|
|
llvm::ConstantInt::get(CGF.IntTy, ~(1ULL << GuardNum));
|
|
Builder.CreateStore(Builder.CreateAnd(LI, Mask), Guard);
|
|
}
|
|
};
|
|
|
|
struct CallInitThreadAbort final : EHScopeStack::Cleanup {
|
|
llvm::Value *Guard;
|
|
CallInitThreadAbort(Address Guard) : Guard(Guard.getPointer()) {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
// Calling _Init_thread_abort will reset the guard's state.
|
|
CGF.EmitNounwindRuntimeCall(getInitThreadAbortFn(CGF.CGM), Guard);
|
|
}
|
|
};
|
|
}
|
|
|
|
void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
|
|
llvm::GlobalVariable *GV,
|
|
bool PerformInit) {
|
|
// MSVC only uses guards for static locals.
|
|
if (!D.isStaticLocal()) {
|
|
assert(GV->hasWeakLinkage() || GV->hasLinkOnceLinkage());
|
|
// GlobalOpt is allowed to discard the initializer, so use linkonce_odr.
|
|
llvm::Function *F = CGF.CurFn;
|
|
F->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
|
|
F->setComdat(CGM.getModule().getOrInsertComdat(F->getName()));
|
|
CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
|
|
return;
|
|
}
|
|
|
|
bool ThreadlocalStatic = D.getTLSKind();
|
|
bool ThreadsafeStatic = getContext().getLangOpts().ThreadsafeStatics;
|
|
|
|
// Thread-safe static variables which aren't thread-specific have a
|
|
// per-variable guard.
|
|
bool HasPerVariableGuard = ThreadsafeStatic && !ThreadlocalStatic;
|
|
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
llvm::IntegerType *GuardTy = CGF.Int32Ty;
|
|
llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
|
|
CharUnits GuardAlign = CharUnits::fromQuantity(4);
|
|
|
|
// Get the guard variable for this function if we have one already.
|
|
GuardInfo *GI = nullptr;
|
|
if (ThreadlocalStatic)
|
|
GI = &ThreadLocalGuardVariableMap[D.getDeclContext()];
|
|
else if (!ThreadsafeStatic)
|
|
GI = &GuardVariableMap[D.getDeclContext()];
|
|
|
|
llvm::GlobalVariable *GuardVar = GI ? GI->Guard : nullptr;
|
|
unsigned GuardNum;
|
|
if (D.isExternallyVisible()) {
|
|
// Externally visible variables have to be numbered in Sema to properly
|
|
// handle unreachable VarDecls.
|
|
GuardNum = getContext().getStaticLocalNumber(&D);
|
|
assert(GuardNum > 0);
|
|
GuardNum--;
|
|
} else if (HasPerVariableGuard) {
|
|
GuardNum = ThreadSafeGuardNumMap[D.getDeclContext()]++;
|
|
} else {
|
|
// Non-externally visible variables are numbered here in CodeGen.
|
|
GuardNum = GI->BitIndex++;
|
|
}
|
|
|
|
if (!HasPerVariableGuard && GuardNum >= 32) {
|
|
if (D.isExternallyVisible())
|
|
ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
|
|
GuardNum %= 32;
|
|
GuardVar = nullptr;
|
|
}
|
|
|
|
if (!GuardVar) {
|
|
// Mangle the name for the guard.
|
|
SmallString<256> GuardName;
|
|
{
|
|
llvm::raw_svector_ostream Out(GuardName);
|
|
if (HasPerVariableGuard)
|
|
getMangleContext().mangleThreadSafeStaticGuardVariable(&D, GuardNum,
|
|
Out);
|
|
else
|
|
getMangleContext().mangleStaticGuardVariable(&D, Out);
|
|
}
|
|
|
|
// Create the guard variable with a zero-initializer. Just absorb linkage,
|
|
// visibility and dll storage class from the guarded variable.
|
|
GuardVar =
|
|
new llvm::GlobalVariable(CGM.getModule(), GuardTy, /*isConstant=*/false,
|
|
GV->getLinkage(), Zero, GuardName.str());
|
|
GuardVar->setVisibility(GV->getVisibility());
|
|
GuardVar->setDLLStorageClass(GV->getDLLStorageClass());
|
|
GuardVar->setAlignment(GuardAlign.getAsAlign());
|
|
if (GuardVar->isWeakForLinker())
|
|
GuardVar->setComdat(
|
|
CGM.getModule().getOrInsertComdat(GuardVar->getName()));
|
|
if (D.getTLSKind())
|
|
CGM.setTLSMode(GuardVar, D);
|
|
if (GI && !HasPerVariableGuard)
|
|
GI->Guard = GuardVar;
|
|
}
|
|
|
|
ConstantAddress GuardAddr(GuardVar, GuardAlign);
|
|
|
|
assert(GuardVar->getLinkage() == GV->getLinkage() &&
|
|
"static local from the same function had different linkage");
|
|
|
|
if (!HasPerVariableGuard) {
|
|
// 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, 1ULL << GuardNum);
|
|
llvm::LoadInst *LI = Builder.CreateLoad(GuardAddr);
|
|
llvm::Value *NeedsInit =
|
|
Builder.CreateICmpEQ(Builder.CreateAnd(LI, Bit), Zero);
|
|
llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
|
|
llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
|
|
CGF.EmitCXXGuardedInitBranch(NeedsInit, InitBlock, EndBlock,
|
|
CodeGenFunction::GuardKind::VariableGuard, &D);
|
|
|
|
// 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), GuardAddr);
|
|
CGF.EHStack.pushCleanup<ResetGuardBit>(EHCleanup, GuardAddr, GuardNum);
|
|
CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
|
|
CGF.PopCleanupBlock();
|
|
Builder.CreateBr(EndBlock);
|
|
|
|
// Continue.
|
|
CGF.EmitBlock(EndBlock);
|
|
} else {
|
|
// Pseudo code for the test:
|
|
// if (TSS > _Init_thread_epoch) {
|
|
// _Init_thread_header(&TSS);
|
|
// if (TSS == -1) {
|
|
// ... initialize the object ...;
|
|
// _Init_thread_footer(&TSS);
|
|
// }
|
|
// }
|
|
//
|
|
// The algorithm is almost identical to what can be found in the appendix
|
|
// found in N2325.
|
|
|
|
// This BasicBLock determines whether or not we have any work to do.
|
|
llvm::LoadInst *FirstGuardLoad = Builder.CreateLoad(GuardAddr);
|
|
FirstGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
|
|
llvm::LoadInst *InitThreadEpoch =
|
|
Builder.CreateLoad(getInitThreadEpochPtr(CGM));
|
|
llvm::Value *IsUninitialized =
|
|
Builder.CreateICmpSGT(FirstGuardLoad, InitThreadEpoch);
|
|
llvm::BasicBlock *AttemptInitBlock = CGF.createBasicBlock("init.attempt");
|
|
llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
|
|
CGF.EmitCXXGuardedInitBranch(IsUninitialized, AttemptInitBlock, EndBlock,
|
|
CodeGenFunction::GuardKind::VariableGuard, &D);
|
|
|
|
// This BasicBlock attempts to determine whether or not this thread is
|
|
// responsible for doing the initialization.
|
|
CGF.EmitBlock(AttemptInitBlock);
|
|
CGF.EmitNounwindRuntimeCall(getInitThreadHeaderFn(CGM),
|
|
GuardAddr.getPointer());
|
|
llvm::LoadInst *SecondGuardLoad = Builder.CreateLoad(GuardAddr);
|
|
SecondGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
|
|
llvm::Value *ShouldDoInit =
|
|
Builder.CreateICmpEQ(SecondGuardLoad, getAllOnesInt());
|
|
llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
|
|
Builder.CreateCondBr(ShouldDoInit, InitBlock, EndBlock);
|
|
|
|
// Ok, we ended up getting selected as the initializing thread.
|
|
CGF.EmitBlock(InitBlock);
|
|
CGF.EHStack.pushCleanup<CallInitThreadAbort>(EHCleanup, GuardAddr);
|
|
CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
|
|
CGF.PopCleanupBlock();
|
|
CGF.EmitNounwindRuntimeCall(getInitThreadFooterFn(CGM),
|
|
GuardAddr.getPointer());
|
|
Builder.CreateBr(EndBlock);
|
|
|
|
CGF.EmitBlock(EndBlock);
|
|
}
|
|
}
|
|
|
|
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->getMostRecentCXXRecordDecl();
|
|
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
|
|
return (!inheritanceModelHasVBTableOffsetField(Inheritance) &&
|
|
RD->nullFieldOffsetIsZero());
|
|
}
|
|
|
|
llvm::Type *
|
|
MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
|
|
const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
|
|
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 (inheritanceModelHasNVOffsetField(MPT->isMemberFunctionPointer(),
|
|
Inheritance))
|
|
fields.push_back(CGM.IntTy);
|
|
if (inheritanceModelHasVBPtrOffsetField(Inheritance))
|
|
fields.push_back(CGM.IntTy);
|
|
if (inheritanceModelHasVBTableOffsetField(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->getMostRecentCXXRecordDecl();
|
|
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
|
|
if (MPT->isMemberFunctionPointer()) {
|
|
// FunctionPointerOrVirtualThunk
|
|
fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
|
|
} else {
|
|
if (RD->nullFieldOffsetIsZero())
|
|
fields.push_back(getZeroInt()); // FieldOffset
|
|
else
|
|
fields.push_back(getAllOnesInt()); // FieldOffset
|
|
}
|
|
|
|
if (inheritanceModelHasNVOffsetField(MPT->isMemberFunctionPointer(),
|
|
Inheritance))
|
|
fields.push_back(getZeroInt());
|
|
if (inheritanceModelHasVBPtrOffsetField(Inheritance))
|
|
fields.push_back(getZeroInt());
|
|
if (inheritanceModelHasVBTableOffsetField(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,
|
|
unsigned VBTableIndex) {
|
|
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
|
|
|
|
// Single inheritance class member pointer are represented as scalars instead
|
|
// of aggregates.
|
|
if (inheritanceModelHasOnlyOneField(IsMemberFunction, Inheritance))
|
|
return FirstField;
|
|
|
|
llvm::SmallVector<llvm::Constant *, 4> fields;
|
|
fields.push_back(FirstField);
|
|
|
|
if (inheritanceModelHasNVOffsetField(IsMemberFunction, Inheritance))
|
|
fields.push_back(llvm::ConstantInt::get(
|
|
CGM.IntTy, NonVirtualBaseAdjustment.getQuantity()));
|
|
|
|
if (inheritanceModelHasVBPtrOffsetField(Inheritance)) {
|
|
CharUnits Offs = CharUnits::Zero();
|
|
if (VBTableIndex)
|
|
Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
|
|
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 (inheritanceModelHasVBTableOffsetField(Inheritance))
|
|
fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBTableIndex));
|
|
|
|
return llvm::ConstantStruct::getAnon(fields);
|
|
}
|
|
|
|
llvm::Constant *
|
|
MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
|
|
CharUnits offset) {
|
|
return EmitMemberDataPointer(MPT->getMostRecentCXXRecordDecl(), offset);
|
|
}
|
|
|
|
llvm::Constant *MicrosoftCXXABI::EmitMemberDataPointer(const CXXRecordDecl *RD,
|
|
CharUnits offset) {
|
|
if (RD->getMSInheritanceModel() ==
|
|
MSInheritanceModel::Virtual)
|
|
offset -= getContext().getOffsetOfBaseWithVBPtr(RD);
|
|
llvm::Constant *FirstField =
|
|
llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
|
|
return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
|
|
CharUnits::Zero(), /*VBTableIndex=*/0);
|
|
}
|
|
|
|
llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
|
|
QualType MPType) {
|
|
const MemberPointerType *DstTy = MPType->castAs<MemberPointerType>();
|
|
const ValueDecl *MPD = MP.getMemberPointerDecl();
|
|
if (!MPD)
|
|
return EmitNullMemberPointer(DstTy);
|
|
|
|
ASTContext &Ctx = getContext();
|
|
ArrayRef<const CXXRecordDecl *> MemberPointerPath = MP.getMemberPointerPath();
|
|
|
|
llvm::Constant *C;
|
|
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) {
|
|
C = EmitMemberFunctionPointer(MD);
|
|
} else {
|
|
// For a pointer to data member, start off with the offset of the field in
|
|
// the class in which it was declared, and convert from there if necessary.
|
|
// For indirect field decls, get the outermost anonymous field and use the
|
|
// parent class.
|
|
CharUnits FieldOffset = Ctx.toCharUnitsFromBits(Ctx.getFieldOffset(MPD));
|
|
const FieldDecl *FD = dyn_cast<FieldDecl>(MPD);
|
|
if (!FD)
|
|
FD = cast<FieldDecl>(*cast<IndirectFieldDecl>(MPD)->chain_begin());
|
|
const CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getParent());
|
|
RD = RD->getMostRecentNonInjectedDecl();
|
|
C = EmitMemberDataPointer(RD, FieldOffset);
|
|
}
|
|
|
|
if (!MemberPointerPath.empty()) {
|
|
const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(MPD->getDeclContext());
|
|
const Type *SrcRecTy = Ctx.getTypeDeclType(SrcRD).getTypePtr();
|
|
const MemberPointerType *SrcTy =
|
|
Ctx.getMemberPointerType(DstTy->getPointeeType(), SrcRecTy)
|
|
->castAs<MemberPointerType>();
|
|
|
|
bool DerivedMember = MP.isMemberPointerToDerivedMember();
|
|
SmallVector<const CXXBaseSpecifier *, 4> DerivedToBasePath;
|
|
const CXXRecordDecl *PrevRD = SrcRD;
|
|
for (const CXXRecordDecl *PathElem : MemberPointerPath) {
|
|
const CXXRecordDecl *Base = nullptr;
|
|
const CXXRecordDecl *Derived = nullptr;
|
|
if (DerivedMember) {
|
|
Base = PathElem;
|
|
Derived = PrevRD;
|
|
} else {
|
|
Base = PrevRD;
|
|
Derived = PathElem;
|
|
}
|
|
for (const CXXBaseSpecifier &BS : Derived->bases())
|
|
if (BS.getType()->getAsCXXRecordDecl()->getCanonicalDecl() ==
|
|
Base->getCanonicalDecl())
|
|
DerivedToBasePath.push_back(&BS);
|
|
PrevRD = PathElem;
|
|
}
|
|
assert(DerivedToBasePath.size() == MemberPointerPath.size());
|
|
|
|
CastKind CK = DerivedMember ? CK_DerivedToBaseMemberPointer
|
|
: CK_BaseToDerivedMemberPointer;
|
|
C = EmitMemberPointerConversion(SrcTy, DstTy, CK, DerivedToBasePath.begin(),
|
|
DerivedToBasePath.end(), C);
|
|
}
|
|
return C;
|
|
}
|
|
|
|
llvm::Constant *
|
|
MicrosoftCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
|
|
assert(MD->isInstance() && "Member function must not be static!");
|
|
|
|
CharUnits NonVirtualBaseAdjustment = CharUnits::Zero();
|
|
const CXXRecordDecl *RD = MD->getParent()->getMostRecentNonInjectedDecl();
|
|
CodeGenTypes &Types = CGM.getTypes();
|
|
|
|
unsigned VBTableIndex = 0;
|
|
llvm::Constant *FirstField;
|
|
const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
|
|
if (!MD->isVirtual()) {
|
|
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);
|
|
} else {
|
|
auto &VTableContext = CGM.getMicrosoftVTableContext();
|
|
MethodVFTableLocation ML = VTableContext.getMethodVFTableLocation(MD);
|
|
FirstField = EmitVirtualMemPtrThunk(MD, ML);
|
|
// Include the vfptr adjustment if the method is in a non-primary vftable.
|
|
NonVirtualBaseAdjustment += ML.VFPtrOffset;
|
|
if (ML.VBase)
|
|
VBTableIndex = VTableContext.getVBTableIndex(RD, ML.VBase) * 4;
|
|
}
|
|
|
|
if (VBTableIndex == 0 &&
|
|
RD->getMSInheritanceModel() ==
|
|
MSInheritanceModel::Virtual)
|
|
NonVirtualBaseAdjustment -= getContext().getOffsetOfBaseWithVBPtr(RD);
|
|
|
|
// The rest of the fields are common with data member pointers.
|
|
FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy);
|
|
return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD,
|
|
NonVirtualBaseAdjustment, VBTableIndex);
|
|
}
|
|
|
|
/// 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->getMostRecentCXXRecordDecl();
|
|
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
|
|
if (inheritanceModelHasOnlyOneField(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 = nullptr;
|
|
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.CreateOr(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,
|
|
Address 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.CreateElementBitCast(This, CGM.Int8Ty);
|
|
llvm::Value *VBPtr =
|
|
Builder.CreateInBoundsGEP(This.getPointer(), VBPtrOffset, "vbptr");
|
|
if (VBPtrOut) *VBPtrOut = VBPtr;
|
|
VBPtr = Builder.CreateBitCast(VBPtr,
|
|
CGM.Int32Ty->getPointerTo(0)->getPointerTo(This.getAddressSpace()));
|
|
|
|
CharUnits VBPtrAlign;
|
|
if (auto CI = dyn_cast<llvm::ConstantInt>(VBPtrOffset)) {
|
|
VBPtrAlign = This.getAlignment().alignmentAtOffset(
|
|
CharUnits::fromQuantity(CI->getSExtValue()));
|
|
} else {
|
|
VBPtrAlign = CGF.getPointerAlign();
|
|
}
|
|
|
|
llvm::Value *VBTable = Builder.CreateAlignedLoad(VBPtr, VBPtrAlign, "vbtable");
|
|
|
|
// Translate from byte offset to table index. It improves analyzability.
|
|
llvm::Value *VBTableIndex = Builder.CreateAShr(
|
|
VBTableOffset, llvm::ConstantInt::get(VBTableOffset->getType(), 2),
|
|
"vbtindex", /*isExact=*/true);
|
|
|
|
// Load an i32 offset from the vb-table.
|
|
llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableIndex);
|
|
VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
|
|
return Builder.CreateAlignedLoad(VBaseOffs, CharUnits::fromQuantity(4),
|
|
"vbase_offs");
|
|
}
|
|
|
|
// Returns an adjusted base cast to i8*, since we do more address arithmetic on
|
|
// it.
|
|
llvm::Value *MicrosoftCXXABI::AdjustVirtualBase(
|
|
CodeGenFunction &CGF, const Expr *E, const CXXRecordDecl *RD,
|
|
Address Base, llvm::Value *VBTableOffset, llvm::Value *VBPtrOffset) {
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
Base = Builder.CreateElementBitCast(Base, CGM.Int8Ty);
|
|
llvm::BasicBlock *OriginalBB = nullptr;
|
|
llvm::BasicBlock *SkipAdjustBB = nullptr;
|
|
llvm::BasicBlock *VBaseAdjustBB = nullptr;
|
|
|
|
// 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->hasDefinition()) {
|
|
DiagnosticsEngine &Diags = CGF.CGM.getDiags();
|
|
unsigned DiagID = Diags.getCustomDiagID(
|
|
DiagnosticsEngine::Error,
|
|
"member pointer representation requires a "
|
|
"complete class type for %0 to perform this expression");
|
|
Diags.Report(E->getExprLoc(), DiagID) << RD << E->getSourceRange();
|
|
} else if (RD->getNumVBases())
|
|
offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
|
|
VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
|
|
}
|
|
llvm::Value *VBPtr = nullptr;
|
|
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.getPointer(), OriginalBB);
|
|
Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
|
|
return Phi;
|
|
}
|
|
return AdjustedBase;
|
|
}
|
|
|
|
llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
|
|
CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) {
|
|
assert(MPT->isMemberDataPointer());
|
|
unsigned AS = Base.getAddressSpace();
|
|
llvm::Type *PType =
|
|
CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
|
|
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 = nullptr;
|
|
llvm::Value *VBPtrOffset = nullptr;
|
|
if (MemPtr->getType()->isStructTy()) {
|
|
// We need to extract values.
|
|
unsigned I = 0;
|
|
FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
|
|
if (inheritanceModelHasVBPtrOffsetField(Inheritance))
|
|
VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
|
|
if (inheritanceModelHasVBTableOffsetField(Inheritance))
|
|
VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
|
|
}
|
|
|
|
llvm::Value *Addr;
|
|
if (VirtualBaseAdjustmentOffset) {
|
|
Addr = AdjustVirtualBase(CGF, E, RD, Base, VirtualBaseAdjustmentOffset,
|
|
VBPtrOffset);
|
|
} else {
|
|
Addr = Base.getPointer();
|
|
}
|
|
|
|
// Cast to char*.
|
|
Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
|
|
|
|
// Apply the offset, which we assume is non-null.
|
|
Addr = Builder.CreateInBoundsGEP(Addr, 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::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>();
|
|
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)
|
|
return Src;
|
|
|
|
CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
|
|
CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
|
|
if (IsReinterpret &&
|
|
SrcRD->nullFieldOffsetIsZero() == DstRD->nullFieldOffsetIsZero())
|
|
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);
|
|
|
|
llvm::Value *Dst = EmitNonNullMemberPointerConversion(
|
|
SrcTy, DstTy, E->getCastKind(), E->path_begin(), E->path_end(), Src,
|
|
Builder);
|
|
|
|
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::Value *MicrosoftCXXABI::EmitNonNullMemberPointerConversion(
|
|
const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
|
|
CastExpr::path_const_iterator PathBegin,
|
|
CastExpr::path_const_iterator PathEnd, llvm::Value *Src,
|
|
CGBuilderTy &Builder) {
|
|
const CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
|
|
const CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
|
|
MSInheritanceModel SrcInheritance = SrcRD->getMSInheritanceModel();
|
|
MSInheritanceModel DstInheritance = DstRD->getMSInheritanceModel();
|
|
bool IsFunc = SrcTy->isMemberFunctionPointer();
|
|
bool IsConstant = isa<llvm::Constant>(Src);
|
|
|
|
// Decompose src.
|
|
llvm::Value *FirstField = Src;
|
|
llvm::Value *NonVirtualBaseAdjustment = getZeroInt();
|
|
llvm::Value *VirtualBaseAdjustmentOffset = getZeroInt();
|
|
llvm::Value *VBPtrOffset = getZeroInt();
|
|
if (!inheritanceModelHasOnlyOneField(IsFunc, SrcInheritance)) {
|
|
// We need to extract values.
|
|
unsigned I = 0;
|
|
FirstField = Builder.CreateExtractValue(Src, I++);
|
|
if (inheritanceModelHasNVOffsetField(IsFunc, SrcInheritance))
|
|
NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++);
|
|
if (inheritanceModelHasVBPtrOffsetField(SrcInheritance))
|
|
VBPtrOffset = Builder.CreateExtractValue(Src, I++);
|
|
if (inheritanceModelHasVBTableOffsetField(SrcInheritance))
|
|
VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++);
|
|
}
|
|
|
|
bool IsDerivedToBase = (CK == CK_DerivedToBaseMemberPointer);
|
|
const MemberPointerType *DerivedTy = IsDerivedToBase ? SrcTy : DstTy;
|
|
const CXXRecordDecl *DerivedClass = DerivedTy->getMostRecentCXXRecordDecl();
|
|
|
|
// For data pointers, we adjust the field offset directly. For functions, we
|
|
// have a separate field.
|
|
llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField;
|
|
|
|
// The virtual inheritance model has a quirk: the virtual base table is always
|
|
// referenced when dereferencing a member pointer even if the member pointer
|
|
// is non-virtual. This is accounted for by adjusting the non-virtual offset
|
|
// to point backwards to the top of the MDC from the first VBase. Undo this
|
|
// adjustment to normalize the member pointer.
|
|
llvm::Value *SrcVBIndexEqZero =
|
|
Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
|
|
if (SrcInheritance == MSInheritanceModel::Virtual) {
|
|
if (int64_t SrcOffsetToFirstVBase =
|
|
getContext().getOffsetOfBaseWithVBPtr(SrcRD).getQuantity()) {
|
|
llvm::Value *UndoSrcAdjustment = Builder.CreateSelect(
|
|
SrcVBIndexEqZero,
|
|
llvm::ConstantInt::get(CGM.IntTy, SrcOffsetToFirstVBase),
|
|
getZeroInt());
|
|
NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, UndoSrcAdjustment);
|
|
}
|
|
}
|
|
|
|
// A non-zero vbindex implies that we are dealing with a source member in a
|
|
// floating virtual base in addition to some non-virtual offset. If the
|
|
// vbindex is zero, we are dealing with a source that exists in a non-virtual,
|
|
// fixed, base. The difference between these two cases is that the vbindex +
|
|
// nvoffset *always* point to the member regardless of what context they are
|
|
// evaluated in so long as the vbindex is adjusted. A member inside a fixed
|
|
// base requires explicit nv adjustment.
|
|
llvm::Constant *BaseClassOffset = llvm::ConstantInt::get(
|
|
CGM.IntTy,
|
|
CGM.computeNonVirtualBaseClassOffset(DerivedClass, PathBegin, PathEnd)
|
|
.getQuantity());
|
|
|
|
llvm::Value *NVDisp;
|
|
if (IsDerivedToBase)
|
|
NVDisp = Builder.CreateNSWSub(NVAdjustField, BaseClassOffset, "adj");
|
|
else
|
|
NVDisp = Builder.CreateNSWAdd(NVAdjustField, BaseClassOffset, "adj");
|
|
|
|
NVAdjustField = Builder.CreateSelect(SrcVBIndexEqZero, NVDisp, getZeroInt());
|
|
|
|
// Update the vbindex to an appropriate value in the destination because
|
|
// SrcRD's vbtable might not be a strict prefix of the one in DstRD.
|
|
llvm::Value *DstVBIndexEqZero = SrcVBIndexEqZero;
|
|
if (inheritanceModelHasVBTableOffsetField(DstInheritance) &&
|
|
inheritanceModelHasVBTableOffsetField(SrcInheritance)) {
|
|
if (llvm::GlobalVariable *VDispMap =
|
|
getAddrOfVirtualDisplacementMap(SrcRD, DstRD)) {
|
|
llvm::Value *VBIndex = Builder.CreateExactUDiv(
|
|
VirtualBaseAdjustmentOffset, llvm::ConstantInt::get(CGM.IntTy, 4));
|
|
if (IsConstant) {
|
|
llvm::Constant *Mapping = VDispMap->getInitializer();
|
|
VirtualBaseAdjustmentOffset =
|
|
Mapping->getAggregateElement(cast<llvm::Constant>(VBIndex));
|
|
} else {
|
|
llvm::Value *Idxs[] = {getZeroInt(), VBIndex};
|
|
VirtualBaseAdjustmentOffset =
|
|
Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(VDispMap, Idxs),
|
|
CharUnits::fromQuantity(4));
|
|
}
|
|
|
|
DstVBIndexEqZero =
|
|
Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
|
|
}
|
|
}
|
|
|
|
// Set the VBPtrOffset to zero if the vbindex is zero. Otherwise, initialize
|
|
// it to the offset of the vbptr.
|
|
if (inheritanceModelHasVBPtrOffsetField(DstInheritance)) {
|
|
llvm::Value *DstVBPtrOffset = llvm::ConstantInt::get(
|
|
CGM.IntTy,
|
|
getContext().getASTRecordLayout(DstRD).getVBPtrOffset().getQuantity());
|
|
VBPtrOffset =
|
|
Builder.CreateSelect(DstVBIndexEqZero, getZeroInt(), DstVBPtrOffset);
|
|
}
|
|
|
|
// Likewise, apply a similar adjustment so that dereferencing the member
|
|
// pointer correctly accounts for the distance between the start of the first
|
|
// virtual base and the top of the MDC.
|
|
if (DstInheritance == MSInheritanceModel::Virtual) {
|
|
if (int64_t DstOffsetToFirstVBase =
|
|
getContext().getOffsetOfBaseWithVBPtr(DstRD).getQuantity()) {
|
|
llvm::Value *DoDstAdjustment = Builder.CreateSelect(
|
|
DstVBIndexEqZero,
|
|
llvm::ConstantInt::get(CGM.IntTy, DstOffsetToFirstVBase),
|
|
getZeroInt());
|
|
NVAdjustField = Builder.CreateNSWSub(NVAdjustField, DoDstAdjustment);
|
|
}
|
|
}
|
|
|
|
// Recompose dst from the null struct and the adjusted fields from src.
|
|
llvm::Value *Dst;
|
|
if (inheritanceModelHasOnlyOneField(IsFunc, DstInheritance)) {
|
|
Dst = FirstField;
|
|
} else {
|
|
Dst = llvm::UndefValue::get(ConvertMemberPointerType(DstTy));
|
|
unsigned Idx = 0;
|
|
Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++);
|
|
if (inheritanceModelHasNVOffsetField(IsFunc, DstInheritance))
|
|
Dst = Builder.CreateInsertValue(Dst, NonVirtualBaseAdjustment, Idx++);
|
|
if (inheritanceModelHasVBPtrOffsetField(DstInheritance))
|
|
Dst = Builder.CreateInsertValue(Dst, VBPtrOffset, Idx++);
|
|
if (inheritanceModelHasVBTableOffsetField(DstInheritance))
|
|
Dst = Builder.CreateInsertValue(Dst, VirtualBaseAdjustmentOffset, Idx++);
|
|
}
|
|
return Dst;
|
|
}
|
|
|
|
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>();
|
|
|
|
CastKind CK = E->getCastKind();
|
|
|
|
return EmitMemberPointerConversion(SrcTy, DstTy, CK, E->path_begin(),
|
|
E->path_end(), Src);
|
|
}
|
|
|
|
llvm::Constant *MicrosoftCXXABI::EmitMemberPointerConversion(
|
|
const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
|
|
CastExpr::path_const_iterator PathBegin,
|
|
CastExpr::path_const_iterator PathEnd, llvm::Constant *Src) {
|
|
assert(CK == CK_DerivedToBaseMemberPointer ||
|
|
CK == CK_BaseToDerivedMemberPointer ||
|
|
CK == CK_ReinterpretMemberPointer);
|
|
// 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 (CK == CK_ReinterpretMemberPointer)
|
|
return Src;
|
|
|
|
CGBuilderTy Builder(CGM, CGM.getLLVMContext());
|
|
auto *Dst = cast<llvm::Constant>(EmitNonNullMemberPointerConversion(
|
|
SrcTy, DstTy, CK, PathBegin, PathEnd, Src, Builder));
|
|
|
|
return Dst;
|
|
}
|
|
|
|
CGCallee MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(
|
|
CodeGenFunction &CGF, const Expr *E, Address This,
|
|
llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) {
|
|
assert(MPT->isMemberFunctionPointer());
|
|
const FunctionProtoType *FPT =
|
|
MPT->getPointeeType()->castAs<FunctionProtoType>();
|
|
const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
|
|
llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
|
|
CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
|
|
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 = nullptr;
|
|
llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
|
|
llvm::Value *VBPtrOffset = nullptr;
|
|
if (MemPtr->getType()->isStructTy()) {
|
|
// We need to extract values.
|
|
unsigned I = 0;
|
|
FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
|
|
if (inheritanceModelHasNVOffsetField(MPT, Inheritance))
|
|
NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
|
|
if (inheritanceModelHasVBPtrOffsetField(Inheritance))
|
|
VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
|
|
if (inheritanceModelHasVBTableOffsetField(Inheritance))
|
|
VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
|
|
}
|
|
|
|
if (VirtualBaseAdjustmentOffset) {
|
|
ThisPtrForCall = AdjustVirtualBase(CGF, E, RD, This,
|
|
VirtualBaseAdjustmentOffset, VBPtrOffset);
|
|
} else {
|
|
ThisPtrForCall = This.getPointer();
|
|
}
|
|
|
|
if (NonVirtualBaseAdjustment) {
|
|
// Apply the adjustment and cast back to the original struct type.
|
|
llvm::Value *Ptr = Builder.CreateBitCast(ThisPtrForCall, CGF.Int8PtrTy);
|
|
Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
|
|
ThisPtrForCall = Builder.CreateBitCast(Ptr, ThisPtrForCall->getType(),
|
|
"this.adjusted");
|
|
}
|
|
|
|
FunctionPointer =
|
|
Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
|
|
CGCallee Callee(FPT, FunctionPointer);
|
|
return Callee;
|
|
}
|
|
|
|
CGCXXABI *clang::CodeGen::CreateMicrosoftCXXABI(CodeGenModule &CGM) {
|
|
return new MicrosoftCXXABI(CGM);
|
|
}
|
|
|
|
// MS RTTI Overview:
|
|
// The run time type information emitted by cl.exe contains 5 distinct types of
|
|
// structures. Many of them reference each other.
|
|
//
|
|
// TypeInfo: Static classes that are returned by typeid.
|
|
//
|
|
// CompleteObjectLocator: Referenced by vftables. They contain information
|
|
// required for dynamic casting, including OffsetFromTop. They also contain
|
|
// a reference to the TypeInfo for the type and a reference to the
|
|
// CompleteHierarchyDescriptor for the type.
|
|
//
|
|
// ClassHierarchyDescriptor: Contains information about a class hierarchy.
|
|
// Used during dynamic_cast to walk a class hierarchy. References a base
|
|
// class array and the size of said array.
|
|
//
|
|
// BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
|
|
// somewhat of a misnomer because the most derived class is also in the list
|
|
// as well as multiple copies of virtual bases (if they occur multiple times
|
|
// in the hierarchy.) The BaseClassArray contains one BaseClassDescriptor for
|
|
// every path in the hierarchy, in pre-order depth first order. Note, we do
|
|
// not declare a specific llvm type for BaseClassArray, it's merely an array
|
|
// of BaseClassDescriptor pointers.
|
|
//
|
|
// BaseClassDescriptor: Contains information about a class in a class hierarchy.
|
|
// BaseClassDescriptor is also somewhat of a misnomer for the same reason that
|
|
// BaseClassArray is. It contains information about a class within a
|
|
// hierarchy such as: is this base is ambiguous and what is its offset in the
|
|
// vbtable. The names of the BaseClassDescriptors have all of their fields
|
|
// mangled into them so they can be aggressively deduplicated by the linker.
|
|
|
|
static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
|
|
StringRef MangledName("??_7type_info@@6B@");
|
|
if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
|
|
return VTable;
|
|
return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
|
|
/*isConstant=*/true,
|
|
llvm::GlobalVariable::ExternalLinkage,
|
|
/*Initializer=*/nullptr, MangledName);
|
|
}
|
|
|
|
namespace {
|
|
|
|
/// A Helper struct that stores information about a class in a class
|
|
/// hierarchy. The information stored in these structs struct is used during
|
|
/// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
|
|
// During RTTI creation, MSRTTIClasses are stored in a contiguous array with
|
|
// implicit depth first pre-order tree connectivity. getFirstChild and
|
|
// getNextSibling allow us to walk the tree efficiently.
|
|
struct MSRTTIClass {
|
|
enum {
|
|
IsPrivateOnPath = 1 | 8,
|
|
IsAmbiguous = 2,
|
|
IsPrivate = 4,
|
|
IsVirtual = 16,
|
|
HasHierarchyDescriptor = 64
|
|
};
|
|
MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
|
|
uint32_t initialize(const MSRTTIClass *Parent,
|
|
const CXXBaseSpecifier *Specifier);
|
|
|
|
MSRTTIClass *getFirstChild() { return this + 1; }
|
|
static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
|
|
return Child + 1 + Child->NumBases;
|
|
}
|
|
|
|
const CXXRecordDecl *RD, *VirtualRoot;
|
|
uint32_t Flags, NumBases, OffsetInVBase;
|
|
};
|
|
|
|
/// Recursively initialize the base class array.
|
|
uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
|
|
const CXXBaseSpecifier *Specifier) {
|
|
Flags = HasHierarchyDescriptor;
|
|
if (!Parent) {
|
|
VirtualRoot = nullptr;
|
|
OffsetInVBase = 0;
|
|
} else {
|
|
if (Specifier->getAccessSpecifier() != AS_public)
|
|
Flags |= IsPrivate | IsPrivateOnPath;
|
|
if (Specifier->isVirtual()) {
|
|
Flags |= IsVirtual;
|
|
VirtualRoot = RD;
|
|
OffsetInVBase = 0;
|
|
} else {
|
|
if (Parent->Flags & IsPrivateOnPath)
|
|
Flags |= IsPrivateOnPath;
|
|
VirtualRoot = Parent->VirtualRoot;
|
|
OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
|
|
.getASTRecordLayout(Parent->RD).getBaseClassOffset(RD).getQuantity();
|
|
}
|
|
}
|
|
NumBases = 0;
|
|
MSRTTIClass *Child = getFirstChild();
|
|
for (const CXXBaseSpecifier &Base : RD->bases()) {
|
|
NumBases += Child->initialize(this, &Base) + 1;
|
|
Child = getNextChild(Child);
|
|
}
|
|
return NumBases;
|
|
}
|
|
|
|
static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
|
|
switch (Ty->getLinkage()) {
|
|
case NoLinkage:
|
|
case InternalLinkage:
|
|
case UniqueExternalLinkage:
|
|
return llvm::GlobalValue::InternalLinkage;
|
|
|
|
case VisibleNoLinkage:
|
|
case ModuleInternalLinkage:
|
|
case ModuleLinkage:
|
|
case ExternalLinkage:
|
|
return llvm::GlobalValue::LinkOnceODRLinkage;
|
|
}
|
|
llvm_unreachable("Invalid linkage!");
|
|
}
|
|
|
|
/// An ephemeral helper class for building MS RTTI types. It caches some
|
|
/// calls to the module and information about the most derived class in a
|
|
/// hierarchy.
|
|
struct MSRTTIBuilder {
|
|
enum {
|
|
HasBranchingHierarchy = 1,
|
|
HasVirtualBranchingHierarchy = 2,
|
|
HasAmbiguousBases = 4
|
|
};
|
|
|
|
MSRTTIBuilder(MicrosoftCXXABI &ABI, const CXXRecordDecl *RD)
|
|
: CGM(ABI.CGM), Context(CGM.getContext()),
|
|
VMContext(CGM.getLLVMContext()), Module(CGM.getModule()), RD(RD),
|
|
Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
|
|
ABI(ABI) {}
|
|
|
|
llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
|
|
llvm::GlobalVariable *
|
|
getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
|
|
llvm::GlobalVariable *getClassHierarchyDescriptor();
|
|
llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo &Info);
|
|
|
|
CodeGenModule &CGM;
|
|
ASTContext &Context;
|
|
llvm::LLVMContext &VMContext;
|
|
llvm::Module &Module;
|
|
const CXXRecordDecl *RD;
|
|
llvm::GlobalVariable::LinkageTypes Linkage;
|
|
MicrosoftCXXABI &ABI;
|
|
};
|
|
|
|
} // namespace
|
|
|
|
/// Recursively serializes a class hierarchy in pre-order depth first
|
|
/// order.
|
|
static void serializeClassHierarchy(SmallVectorImpl<MSRTTIClass> &Classes,
|
|
const CXXRecordDecl *RD) {
|
|
Classes.push_back(MSRTTIClass(RD));
|
|
for (const CXXBaseSpecifier &Base : RD->bases())
|
|
serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
|
|
}
|
|
|
|
/// Find ambiguity among base classes.
|
|
static void
|
|
detectAmbiguousBases(SmallVectorImpl<MSRTTIClass> &Classes) {
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
|
|
for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
|
|
if ((Class->Flags & MSRTTIClass::IsVirtual) &&
|
|
!VirtualBases.insert(Class->RD).second) {
|
|
Class = MSRTTIClass::getNextChild(Class);
|
|
continue;
|
|
}
|
|
if (!UniqueBases.insert(Class->RD).second)
|
|
AmbiguousBases.insert(Class->RD);
|
|
Class++;
|
|
}
|
|
if (AmbiguousBases.empty())
|
|
return;
|
|
for (MSRTTIClass &Class : Classes)
|
|
if (AmbiguousBases.count(Class.RD))
|
|
Class.Flags |= MSRTTIClass::IsAmbiguous;
|
|
}
|
|
|
|
llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
ABI.getMangleContext().mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
|
|
}
|
|
|
|
// Check to see if we've already declared this ClassHierarchyDescriptor.
|
|
if (auto CHD = Module.getNamedGlobal(MangledName))
|
|
return CHD;
|
|
|
|
// Serialize the class hierarchy and initialize the CHD Fields.
|
|
SmallVector<MSRTTIClass, 8> Classes;
|
|
serializeClassHierarchy(Classes, RD);
|
|
Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
|
|
detectAmbiguousBases(Classes);
|
|
int Flags = 0;
|
|
for (auto Class : Classes) {
|
|
if (Class.RD->getNumBases() > 1)
|
|
Flags |= HasBranchingHierarchy;
|
|
// Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
|
|
// believe the field isn't actually used.
|
|
if (Class.Flags & MSRTTIClass::IsAmbiguous)
|
|
Flags |= HasAmbiguousBases;
|
|
}
|
|
if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
|
|
Flags |= HasVirtualBranchingHierarchy;
|
|
// These gep indices are used to get the address of the first element of the
|
|
// base class array.
|
|
llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
|
|
llvm::ConstantInt::get(CGM.IntTy, 0)};
|
|
|
|
// Forward-declare the class hierarchy descriptor
|
|
auto Type = ABI.getClassHierarchyDescriptorType();
|
|
auto CHD = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
|
|
/*Initializer=*/nullptr,
|
|
MangledName);
|
|
if (CHD->isWeakForLinker())
|
|
CHD->setComdat(CGM.getModule().getOrInsertComdat(CHD->getName()));
|
|
|
|
auto *Bases = getBaseClassArray(Classes);
|
|
|
|
// Initialize the base class ClassHierarchyDescriptor.
|
|
llvm::Constant *Fields[] = {
|
|
llvm::ConstantInt::get(CGM.IntTy, 0), // reserved by the runtime
|
|
llvm::ConstantInt::get(CGM.IntTy, Flags),
|
|
llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
|
|
ABI.getImageRelativeConstant(llvm::ConstantExpr::getInBoundsGetElementPtr(
|
|
Bases->getValueType(), Bases,
|
|
llvm::ArrayRef<llvm::Value *>(GEPIndices))),
|
|
};
|
|
CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
|
|
return CHD;
|
|
}
|
|
|
|
llvm::GlobalVariable *
|
|
MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
ABI.getMangleContext().mangleCXXRTTIBaseClassArray(RD, Out);
|
|
}
|
|
|
|
// Forward-declare the base class array.
|
|
// cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
|
|
// mode) bytes of padding. We provide a pointer sized amount of padding by
|
|
// adding +1 to Classes.size(). The sections have pointer alignment and are
|
|
// marked pick-any so it shouldn't matter.
|
|
llvm::Type *PtrType = ABI.getImageRelativeType(
|
|
ABI.getBaseClassDescriptorType()->getPointerTo());
|
|
auto *ArrType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
|
|
auto *BCA =
|
|
new llvm::GlobalVariable(Module, ArrType,
|
|
/*isConstant=*/true, Linkage,
|
|
/*Initializer=*/nullptr, MangledName);
|
|
if (BCA->isWeakForLinker())
|
|
BCA->setComdat(CGM.getModule().getOrInsertComdat(BCA->getName()));
|
|
|
|
// Initialize the BaseClassArray.
|
|
SmallVector<llvm::Constant *, 8> BaseClassArrayData;
|
|
for (MSRTTIClass &Class : Classes)
|
|
BaseClassArrayData.push_back(
|
|
ABI.getImageRelativeConstant(getBaseClassDescriptor(Class)));
|
|
BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
|
|
BCA->setInitializer(llvm::ConstantArray::get(ArrType, BaseClassArrayData));
|
|
return BCA;
|
|
}
|
|
|
|
llvm::GlobalVariable *
|
|
MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
|
|
// Compute the fields for the BaseClassDescriptor. They are computed up front
|
|
// because they are mangled into the name of the object.
|
|
uint32_t OffsetInVBTable = 0;
|
|
int32_t VBPtrOffset = -1;
|
|
if (Class.VirtualRoot) {
|
|
auto &VTableContext = CGM.getMicrosoftVTableContext();
|
|
OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
|
|
VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
|
|
}
|
|
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
ABI.getMangleContext().mangleCXXRTTIBaseClassDescriptor(
|
|
Class.RD, Class.OffsetInVBase, VBPtrOffset, OffsetInVBTable,
|
|
Class.Flags, Out);
|
|
}
|
|
|
|
// Check to see if we've already declared this object.
|
|
if (auto BCD = Module.getNamedGlobal(MangledName))
|
|
return BCD;
|
|
|
|
// Forward-declare the base class descriptor.
|
|
auto Type = ABI.getBaseClassDescriptorType();
|
|
auto BCD =
|
|
new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
|
|
/*Initializer=*/nullptr, MangledName);
|
|
if (BCD->isWeakForLinker())
|
|
BCD->setComdat(CGM.getModule().getOrInsertComdat(BCD->getName()));
|
|
|
|
// Initialize the BaseClassDescriptor.
|
|
llvm::Constant *Fields[] = {
|
|
ABI.getImageRelativeConstant(
|
|
ABI.getAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
|
|
llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
|
|
llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
|
|
llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
|
|
llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
|
|
llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
|
|
ABI.getImageRelativeConstant(
|
|
MSRTTIBuilder(ABI, Class.RD).getClassHierarchyDescriptor()),
|
|
};
|
|
BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
|
|
return BCD;
|
|
}
|
|
|
|
llvm::GlobalVariable *
|
|
MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo &Info) {
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
ABI.getMangleContext().mangleCXXRTTICompleteObjectLocator(RD, Info.MangledPath, Out);
|
|
}
|
|
|
|
// Check to see if we've already computed this complete object locator.
|
|
if (auto COL = Module.getNamedGlobal(MangledName))
|
|
return COL;
|
|
|
|
// Compute the fields of the complete object locator.
|
|
int OffsetToTop = Info.FullOffsetInMDC.getQuantity();
|
|
int VFPtrOffset = 0;
|
|
// The offset includes the vtordisp if one exists.
|
|
if (const CXXRecordDecl *VBase = Info.getVBaseWithVPtr())
|
|
if (Context.getASTRecordLayout(RD)
|
|
.getVBaseOffsetsMap()
|
|
.find(VBase)
|
|
->second.hasVtorDisp())
|
|
VFPtrOffset = Info.NonVirtualOffset.getQuantity() + 4;
|
|
|
|
// Forward-declare the complete object locator.
|
|
llvm::StructType *Type = ABI.getCompleteObjectLocatorType();
|
|
auto COL = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
|
|
/*Initializer=*/nullptr, MangledName);
|
|
|
|
// Initialize the CompleteObjectLocator.
|
|
llvm::Constant *Fields[] = {
|
|
llvm::ConstantInt::get(CGM.IntTy, ABI.isImageRelative()),
|
|
llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
|
|
llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
|
|
ABI.getImageRelativeConstant(
|
|
CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
|
|
ABI.getImageRelativeConstant(getClassHierarchyDescriptor()),
|
|
ABI.getImageRelativeConstant(COL),
|
|
};
|
|
llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
|
|
if (!ABI.isImageRelative())
|
|
FieldsRef = FieldsRef.drop_back();
|
|
COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
|
|
if (COL->isWeakForLinker())
|
|
COL->setComdat(CGM.getModule().getOrInsertComdat(COL->getName()));
|
|
return COL;
|
|
}
|
|
|
|
static QualType decomposeTypeForEH(ASTContext &Context, QualType T,
|
|
bool &IsConst, bool &IsVolatile,
|
|
bool &IsUnaligned) {
|
|
T = Context.getExceptionObjectType(T);
|
|
|
|
// C++14 [except.handle]p3:
|
|
// A handler is a match for an exception object of type E if [...]
|
|
// - the handler is of type cv T or const T& where T is a pointer type and
|
|
// E is a pointer type that can be converted to T by [...]
|
|
// - a qualification conversion
|
|
IsConst = false;
|
|
IsVolatile = false;
|
|
IsUnaligned = false;
|
|
QualType PointeeType = T->getPointeeType();
|
|
if (!PointeeType.isNull()) {
|
|
IsConst = PointeeType.isConstQualified();
|
|
IsVolatile = PointeeType.isVolatileQualified();
|
|
IsUnaligned = PointeeType.getQualifiers().hasUnaligned();
|
|
}
|
|
|
|
// Member pointer types like "const int A::*" are represented by having RTTI
|
|
// for "int A::*" and separately storing the const qualifier.
|
|
if (const auto *MPTy = T->getAs<MemberPointerType>())
|
|
T = Context.getMemberPointerType(PointeeType.getUnqualifiedType(),
|
|
MPTy->getClass());
|
|
|
|
// Pointer types like "const int * const *" are represented by having RTTI
|
|
// for "const int **" and separately storing the const qualifier.
|
|
if (T->isPointerType())
|
|
T = Context.getPointerType(PointeeType.getUnqualifiedType());
|
|
|
|
return T;
|
|
}
|
|
|
|
CatchTypeInfo
|
|
MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
|
|
QualType CatchHandlerType) {
|
|
// TypeDescriptors for exceptions never have qualified pointer types,
|
|
// qualifiers are stored separately in order to support qualification
|
|
// conversions.
|
|
bool IsConst, IsVolatile, IsUnaligned;
|
|
Type =
|
|
decomposeTypeForEH(getContext(), Type, IsConst, IsVolatile, IsUnaligned);
|
|
|
|
bool IsReference = CatchHandlerType->isReferenceType();
|
|
|
|
uint32_t Flags = 0;
|
|
if (IsConst)
|
|
Flags |= 1;
|
|
if (IsVolatile)
|
|
Flags |= 2;
|
|
if (IsUnaligned)
|
|
Flags |= 4;
|
|
if (IsReference)
|
|
Flags |= 8;
|
|
|
|
return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
|
|
Flags};
|
|
}
|
|
|
|
/// Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
|
|
/// llvm::GlobalVariable * because different type descriptors have different
|
|
/// types, and need to be abstracted. They are abstracting by casting the
|
|
/// address to an Int8PtrTy.
|
|
llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
getMangleContext().mangleCXXRTTI(Type, Out);
|
|
}
|
|
|
|
// Check to see if we've already declared this TypeDescriptor.
|
|
if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
|
|
return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
|
|
|
|
// Note for the future: If we would ever like to do deferred emission of
|
|
// RTTI, check if emitting vtables opportunistically need any adjustment.
|
|
|
|
// Compute the fields for the TypeDescriptor.
|
|
SmallString<256> TypeInfoString;
|
|
{
|
|
llvm::raw_svector_ostream Out(TypeInfoString);
|
|
getMangleContext().mangleCXXRTTIName(Type, Out);
|
|
}
|
|
|
|
// Declare and initialize the TypeDescriptor.
|
|
llvm::Constant *Fields[] = {
|
|
getTypeInfoVTable(CGM), // VFPtr
|
|
llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
|
|
llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
|
|
llvm::StructType *TypeDescriptorType =
|
|
getTypeDescriptorType(TypeInfoString);
|
|
auto *Var = new llvm::GlobalVariable(
|
|
CGM.getModule(), TypeDescriptorType, /*isConstant=*/false,
|
|
getLinkageForRTTI(Type),
|
|
llvm::ConstantStruct::get(TypeDescriptorType, Fields),
|
|
MangledName);
|
|
if (Var->isWeakForLinker())
|
|
Var->setComdat(CGM.getModule().getOrInsertComdat(Var->getName()));
|
|
return llvm::ConstantExpr::getBitCast(Var, CGM.Int8PtrTy);
|
|
}
|
|
|
|
/// Gets or a creates a Microsoft CompleteObjectLocator.
|
|
llvm::GlobalVariable *
|
|
MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
|
|
const VPtrInfo &Info) {
|
|
return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitCXXStructor(GlobalDecl GD) {
|
|
if (auto *ctor = dyn_cast<CXXConstructorDecl>(GD.getDecl())) {
|
|
// There are no constructor variants, always emit the complete destructor.
|
|
llvm::Function *Fn =
|
|
CGM.codegenCXXStructor(GD.getWithCtorType(Ctor_Complete));
|
|
CGM.maybeSetTrivialComdat(*ctor, *Fn);
|
|
return;
|
|
}
|
|
|
|
auto *dtor = cast<CXXDestructorDecl>(GD.getDecl());
|
|
|
|
// Emit the base destructor if the base and complete (vbase) destructors are
|
|
// equivalent. This effectively implements -mconstructor-aliases as part of
|
|
// the ABI.
|
|
if (GD.getDtorType() == Dtor_Complete &&
|
|
dtor->getParent()->getNumVBases() == 0)
|
|
GD = GD.getWithDtorType(Dtor_Base);
|
|
|
|
// The base destructor is equivalent to the base destructor of its
|
|
// base class if there is exactly one non-virtual base class with a
|
|
// non-trivial destructor, there are no fields with a non-trivial
|
|
// destructor, and the body of the destructor is trivial.
|
|
if (GD.getDtorType() == Dtor_Base && !CGM.TryEmitBaseDestructorAsAlias(dtor))
|
|
return;
|
|
|
|
llvm::Function *Fn = CGM.codegenCXXStructor(GD);
|
|
if (Fn->isWeakForLinker())
|
|
Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
|
|
}
|
|
|
|
llvm::Function *
|
|
MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
|
|
CXXCtorType CT) {
|
|
assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
|
|
|
|
// Calculate the mangled name.
|
|
SmallString<256> ThunkName;
|
|
llvm::raw_svector_ostream Out(ThunkName);
|
|
getMangleContext().mangleName(GlobalDecl(CD, CT), Out);
|
|
|
|
// 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().arrangeMSCtorClosure(CD, CT);
|
|
llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
|
|
const CXXRecordDecl *RD = CD->getParent();
|
|
QualType RecordTy = getContext().getRecordType(RD);
|
|
llvm::Function *ThunkFn = llvm::Function::Create(
|
|
ThunkTy, getLinkageForRTTI(RecordTy), ThunkName.str(), &CGM.getModule());
|
|
ThunkFn->setCallingConv(static_cast<llvm::CallingConv::ID>(
|
|
FnInfo.getEffectiveCallingConvention()));
|
|
if (ThunkFn->isWeakForLinker())
|
|
ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
|
|
bool IsCopy = CT == Ctor_CopyingClosure;
|
|
|
|
// Start codegen.
|
|
CodeGenFunction CGF(CGM);
|
|
CGF.CurGD = GlobalDecl(CD, Ctor_Complete);
|
|
|
|
// Build FunctionArgs.
|
|
FunctionArgList FunctionArgs;
|
|
|
|
// A constructor always starts with a 'this' pointer as its first argument.
|
|
buildThisParam(CGF, FunctionArgs);
|
|
|
|
// Following the 'this' pointer is a reference to the source object that we
|
|
// are copying from.
|
|
ImplicitParamDecl SrcParam(
|
|
getContext(), /*DC=*/nullptr, SourceLocation(),
|
|
&getContext().Idents.get("src"),
|
|
getContext().getLValueReferenceType(RecordTy,
|
|
/*SpelledAsLValue=*/true),
|
|
ImplicitParamDecl::Other);
|
|
if (IsCopy)
|
|
FunctionArgs.push_back(&SrcParam);
|
|
|
|
// Constructors for classes which utilize virtual bases have an additional
|
|
// parameter which indicates whether or not it is being delegated to by a more
|
|
// derived constructor.
|
|
ImplicitParamDecl IsMostDerived(getContext(), /*DC=*/nullptr,
|
|
SourceLocation(),
|
|
&getContext().Idents.get("is_most_derived"),
|
|
getContext().IntTy, ImplicitParamDecl::Other);
|
|
// Only add the parameter to the list if the class has virtual bases.
|
|
if (RD->getNumVBases() > 0)
|
|
FunctionArgs.push_back(&IsMostDerived);
|
|
|
|
// Start defining the function.
|
|
auto NL = ApplyDebugLocation::CreateEmpty(CGF);
|
|
CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
|
|
FunctionArgs, CD->getLocation(), SourceLocation());
|
|
// Create a scope with an artificial location for the body of this function.
|
|
auto AL = ApplyDebugLocation::CreateArtificial(CGF);
|
|
setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
|
|
llvm::Value *This = getThisValue(CGF);
|
|
|
|
llvm::Value *SrcVal =
|
|
IsCopy ? CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(&SrcParam), "src")
|
|
: nullptr;
|
|
|
|
CallArgList Args;
|
|
|
|
// Push the this ptr.
|
|
Args.add(RValue::get(This), CD->getThisType());
|
|
|
|
// Push the src ptr.
|
|
if (SrcVal)
|
|
Args.add(RValue::get(SrcVal), SrcParam.getType());
|
|
|
|
// Add the rest of the default arguments.
|
|
SmallVector<const Stmt *, 4> ArgVec;
|
|
ArrayRef<ParmVarDecl *> params = CD->parameters().drop_front(IsCopy ? 1 : 0);
|
|
for (const ParmVarDecl *PD : params) {
|
|
assert(PD->hasDefaultArg() && "ctor closure lacks default args");
|
|
ArgVec.push_back(PD->getDefaultArg());
|
|
}
|
|
|
|
CodeGenFunction::RunCleanupsScope Cleanups(CGF);
|
|
|
|
const auto *FPT = CD->getType()->castAs<FunctionProtoType>();
|
|
CGF.EmitCallArgs(Args, FPT, llvm::makeArrayRef(ArgVec), CD, IsCopy ? 1 : 0);
|
|
|
|
// Insert any ABI-specific implicit constructor arguments.
|
|
AddedStructorArgCounts ExtraArgs =
|
|
addImplicitConstructorArgs(CGF, CD, Ctor_Complete,
|
|
/*ForVirtualBase=*/false,
|
|
/*Delegating=*/false, Args);
|
|
// Call the destructor with our arguments.
|
|
llvm::Constant *CalleePtr =
|
|
CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
|
|
CGCallee Callee =
|
|
CGCallee::forDirect(CalleePtr, GlobalDecl(CD, Ctor_Complete));
|
|
const CGFunctionInfo &CalleeInfo = CGM.getTypes().arrangeCXXConstructorCall(
|
|
Args, CD, Ctor_Complete, ExtraArgs.Prefix, ExtraArgs.Suffix);
|
|
CGF.EmitCall(CalleeInfo, Callee, ReturnValueSlot(), Args);
|
|
|
|
Cleanups.ForceCleanup();
|
|
|
|
// Emit the ret instruction, remove any temporary instructions created for the
|
|
// aid of CodeGen.
|
|
CGF.FinishFunction(SourceLocation());
|
|
|
|
return ThunkFn;
|
|
}
|
|
|
|
llvm::Constant *MicrosoftCXXABI::getCatchableType(QualType T,
|
|
uint32_t NVOffset,
|
|
int32_t VBPtrOffset,
|
|
uint32_t VBIndex) {
|
|
assert(!T->isReferenceType());
|
|
|
|
CXXRecordDecl *RD = T->getAsCXXRecordDecl();
|
|
const CXXConstructorDecl *CD =
|
|
RD ? CGM.getContext().getCopyConstructorForExceptionObject(RD) : nullptr;
|
|
CXXCtorType CT = Ctor_Complete;
|
|
if (CD)
|
|
if (!hasDefaultCXXMethodCC(getContext(), CD) || CD->getNumParams() != 1)
|
|
CT = Ctor_CopyingClosure;
|
|
|
|
uint32_t Size = getContext().getTypeSizeInChars(T).getQuantity();
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
getMangleContext().mangleCXXCatchableType(T, CD, CT, Size, NVOffset,
|
|
VBPtrOffset, VBIndex, Out);
|
|
}
|
|
if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
|
|
return getImageRelativeConstant(GV);
|
|
|
|
// The TypeDescriptor is used by the runtime to determine if a catch handler
|
|
// is appropriate for the exception object.
|
|
llvm::Constant *TD = getImageRelativeConstant(getAddrOfRTTIDescriptor(T));
|
|
|
|
// The runtime is responsible for calling the copy constructor if the
|
|
// exception is caught by value.
|
|
llvm::Constant *CopyCtor;
|
|
if (CD) {
|
|
if (CT == Ctor_CopyingClosure)
|
|
CopyCtor = getAddrOfCXXCtorClosure(CD, Ctor_CopyingClosure);
|
|
else
|
|
CopyCtor = CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
|
|
|
|
CopyCtor = llvm::ConstantExpr::getBitCast(CopyCtor, CGM.Int8PtrTy);
|
|
} else {
|
|
CopyCtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
|
|
}
|
|
CopyCtor = getImageRelativeConstant(CopyCtor);
|
|
|
|
bool IsScalar = !RD;
|
|
bool HasVirtualBases = false;
|
|
bool IsStdBadAlloc = false; // std::bad_alloc is special for some reason.
|
|
QualType PointeeType = T;
|
|
if (T->isPointerType())
|
|
PointeeType = T->getPointeeType();
|
|
if (const CXXRecordDecl *RD = PointeeType->getAsCXXRecordDecl()) {
|
|
HasVirtualBases = RD->getNumVBases() > 0;
|
|
if (IdentifierInfo *II = RD->getIdentifier())
|
|
IsStdBadAlloc = II->isStr("bad_alloc") && RD->isInStdNamespace();
|
|
}
|
|
|
|
// Encode the relevant CatchableType properties into the Flags bitfield.
|
|
// FIXME: Figure out how bits 2 or 8 can get set.
|
|
uint32_t Flags = 0;
|
|
if (IsScalar)
|
|
Flags |= 1;
|
|
if (HasVirtualBases)
|
|
Flags |= 4;
|
|
if (IsStdBadAlloc)
|
|
Flags |= 16;
|
|
|
|
llvm::Constant *Fields[] = {
|
|
llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
|
|
TD, // TypeDescriptor
|
|
llvm::ConstantInt::get(CGM.IntTy, NVOffset), // NonVirtualAdjustment
|
|
llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), // OffsetToVBPtr
|
|
llvm::ConstantInt::get(CGM.IntTy, VBIndex), // VBTableIndex
|
|
llvm::ConstantInt::get(CGM.IntTy, Size), // Size
|
|
CopyCtor // CopyCtor
|
|
};
|
|
llvm::StructType *CTType = getCatchableTypeType();
|
|
auto *GV = new llvm::GlobalVariable(
|
|
CGM.getModule(), CTType, /*isConstant=*/true, getLinkageForRTTI(T),
|
|
llvm::ConstantStruct::get(CTType, Fields), MangledName);
|
|
GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
GV->setSection(".xdata");
|
|
if (GV->isWeakForLinker())
|
|
GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
|
|
return getImageRelativeConstant(GV);
|
|
}
|
|
|
|
llvm::GlobalVariable *MicrosoftCXXABI::getCatchableTypeArray(QualType T) {
|
|
assert(!T->isReferenceType());
|
|
|
|
// See if we've already generated a CatchableTypeArray for this type before.
|
|
llvm::GlobalVariable *&CTA = CatchableTypeArrays[T];
|
|
if (CTA)
|
|
return CTA;
|
|
|
|
// Ensure that we don't have duplicate entries in our CatchableTypeArray by
|
|
// using a SmallSetVector. Duplicates may arise due to virtual bases
|
|
// occurring more than once in the hierarchy.
|
|
llvm::SmallSetVector<llvm::Constant *, 2> CatchableTypes;
|
|
|
|
// C++14 [except.handle]p3:
|
|
// A handler is a match for an exception object of type E if [...]
|
|
// - the handler is of type cv T or cv T& and T is an unambiguous public
|
|
// base class of E, or
|
|
// - the handler is of type cv T or const T& where T is a pointer type and
|
|
// E is a pointer type that can be converted to T by [...]
|
|
// - a standard pointer conversion (4.10) not involving conversions to
|
|
// pointers to private or protected or ambiguous classes
|
|
const CXXRecordDecl *MostDerivedClass = nullptr;
|
|
bool IsPointer = T->isPointerType();
|
|
if (IsPointer)
|
|
MostDerivedClass = T->getPointeeType()->getAsCXXRecordDecl();
|
|
else
|
|
MostDerivedClass = T->getAsCXXRecordDecl();
|
|
|
|
// Collect all the unambiguous public bases of the MostDerivedClass.
|
|
if (MostDerivedClass) {
|
|
const ASTContext &Context = getContext();
|
|
const ASTRecordLayout &MostDerivedLayout =
|
|
Context.getASTRecordLayout(MostDerivedClass);
|
|
MicrosoftVTableContext &VTableContext = CGM.getMicrosoftVTableContext();
|
|
SmallVector<MSRTTIClass, 8> Classes;
|
|
serializeClassHierarchy(Classes, MostDerivedClass);
|
|
Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
|
|
detectAmbiguousBases(Classes);
|
|
for (const MSRTTIClass &Class : Classes) {
|
|
// Skip any ambiguous or private bases.
|
|
if (Class.Flags &
|
|
(MSRTTIClass::IsPrivateOnPath | MSRTTIClass::IsAmbiguous))
|
|
continue;
|
|
// Write down how to convert from a derived pointer to a base pointer.
|
|
uint32_t OffsetInVBTable = 0;
|
|
int32_t VBPtrOffset = -1;
|
|
if (Class.VirtualRoot) {
|
|
OffsetInVBTable =
|
|
VTableContext.getVBTableIndex(MostDerivedClass, Class.VirtualRoot)*4;
|
|
VBPtrOffset = MostDerivedLayout.getVBPtrOffset().getQuantity();
|
|
}
|
|
|
|
// Turn our record back into a pointer if the exception object is a
|
|
// pointer.
|
|
QualType RTTITy = QualType(Class.RD->getTypeForDecl(), 0);
|
|
if (IsPointer)
|
|
RTTITy = Context.getPointerType(RTTITy);
|
|
CatchableTypes.insert(getCatchableType(RTTITy, Class.OffsetInVBase,
|
|
VBPtrOffset, OffsetInVBTable));
|
|
}
|
|
}
|
|
|
|
// C++14 [except.handle]p3:
|
|
// A handler is a match for an exception object of type E if
|
|
// - The handler is of type cv T or cv T& and E and T are the same type
|
|
// (ignoring the top-level cv-qualifiers)
|
|
CatchableTypes.insert(getCatchableType(T));
|
|
|
|
// C++14 [except.handle]p3:
|
|
// A handler is a match for an exception object of type E if
|
|
// - the handler is of type cv T or const T& where T is a pointer type and
|
|
// E is a pointer type that can be converted to T by [...]
|
|
// - a standard pointer conversion (4.10) not involving conversions to
|
|
// pointers to private or protected or ambiguous classes
|
|
//
|
|
// C++14 [conv.ptr]p2:
|
|
// A prvalue of type "pointer to cv T," where T is an object type, can be
|
|
// converted to a prvalue of type "pointer to cv void".
|
|
if (IsPointer && T->getPointeeType()->isObjectType())
|
|
CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
|
|
|
|
// C++14 [except.handle]p3:
|
|
// A handler is a match for an exception object of type E if [...]
|
|
// - the handler is of type cv T or const T& where T is a pointer or
|
|
// pointer to member type and E is std::nullptr_t.
|
|
//
|
|
// We cannot possibly list all possible pointer types here, making this
|
|
// implementation incompatible with the standard. However, MSVC includes an
|
|
// entry for pointer-to-void in this case. Let's do the same.
|
|
if (T->isNullPtrType())
|
|
CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
|
|
|
|
uint32_t NumEntries = CatchableTypes.size();
|
|
llvm::Type *CTType =
|
|
getImageRelativeType(getCatchableTypeType()->getPointerTo());
|
|
llvm::ArrayType *AT = llvm::ArrayType::get(CTType, NumEntries);
|
|
llvm::StructType *CTAType = getCatchableTypeArrayType(NumEntries);
|
|
llvm::Constant *Fields[] = {
|
|
llvm::ConstantInt::get(CGM.IntTy, NumEntries), // NumEntries
|
|
llvm::ConstantArray::get(
|
|
AT, llvm::makeArrayRef(CatchableTypes.begin(),
|
|
CatchableTypes.end())) // CatchableTypes
|
|
};
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
getMangleContext().mangleCXXCatchableTypeArray(T, NumEntries, Out);
|
|
}
|
|
CTA = new llvm::GlobalVariable(
|
|
CGM.getModule(), CTAType, /*isConstant=*/true, getLinkageForRTTI(T),
|
|
llvm::ConstantStruct::get(CTAType, Fields), MangledName);
|
|
CTA->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
CTA->setSection(".xdata");
|
|
if (CTA->isWeakForLinker())
|
|
CTA->setComdat(CGM.getModule().getOrInsertComdat(CTA->getName()));
|
|
return CTA;
|
|
}
|
|
|
|
llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
|
|
bool IsConst, IsVolatile, IsUnaligned;
|
|
T = decomposeTypeForEH(getContext(), T, IsConst, IsVolatile, IsUnaligned);
|
|
|
|
// The CatchableTypeArray enumerates the various (CV-unqualified) types that
|
|
// the exception object may be caught as.
|
|
llvm::GlobalVariable *CTA = getCatchableTypeArray(T);
|
|
// The first field in a CatchableTypeArray is the number of CatchableTypes.
|
|
// This is used as a component of the mangled name which means that we need to
|
|
// know what it is in order to see if we have previously generated the
|
|
// ThrowInfo.
|
|
uint32_t NumEntries =
|
|
cast<llvm::ConstantInt>(CTA->getInitializer()->getAggregateElement(0U))
|
|
->getLimitedValue();
|
|
|
|
SmallString<256> MangledName;
|
|
{
|
|
llvm::raw_svector_ostream Out(MangledName);
|
|
getMangleContext().mangleCXXThrowInfo(T, IsConst, IsVolatile, IsUnaligned,
|
|
NumEntries, Out);
|
|
}
|
|
|
|
// Reuse a previously generated ThrowInfo if we have generated an appropriate
|
|
// one before.
|
|
if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
|
|
return GV;
|
|
|
|
// The RTTI TypeDescriptor uses an unqualified type but catch clauses must
|
|
// be at least as CV qualified. Encode this requirement into the Flags
|
|
// bitfield.
|
|
uint32_t Flags = 0;
|
|
if (IsConst)
|
|
Flags |= 1;
|
|
if (IsVolatile)
|
|
Flags |= 2;
|
|
if (IsUnaligned)
|
|
Flags |= 4;
|
|
|
|
// The cleanup-function (a destructor) must be called when the exception
|
|
// object's lifetime ends.
|
|
llvm::Constant *CleanupFn = llvm::Constant::getNullValue(CGM.Int8PtrTy);
|
|
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
|
|
if (CXXDestructorDecl *DtorD = RD->getDestructor())
|
|
if (!DtorD->isTrivial())
|
|
CleanupFn = llvm::ConstantExpr::getBitCast(
|
|
CGM.getAddrOfCXXStructor(GlobalDecl(DtorD, Dtor_Complete)),
|
|
CGM.Int8PtrTy);
|
|
// This is unused as far as we can tell, initialize it to null.
|
|
llvm::Constant *ForwardCompat =
|
|
getImageRelativeConstant(llvm::Constant::getNullValue(CGM.Int8PtrTy));
|
|
llvm::Constant *PointerToCatchableTypes = getImageRelativeConstant(
|
|
llvm::ConstantExpr::getBitCast(CTA, CGM.Int8PtrTy));
|
|
llvm::StructType *TIType = getThrowInfoType();
|
|
llvm::Constant *Fields[] = {
|
|
llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
|
|
getImageRelativeConstant(CleanupFn), // CleanupFn
|
|
ForwardCompat, // ForwardCompat
|
|
PointerToCatchableTypes // CatchableTypeArray
|
|
};
|
|
auto *GV = new llvm::GlobalVariable(
|
|
CGM.getModule(), TIType, /*isConstant=*/true, getLinkageForRTTI(T),
|
|
llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
|
|
GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
GV->setSection(".xdata");
|
|
if (GV->isWeakForLinker())
|
|
GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
|
|
return GV;
|
|
}
|
|
|
|
void MicrosoftCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
|
|
const Expr *SubExpr = E->getSubExpr();
|
|
QualType ThrowType = SubExpr->getType();
|
|
// The exception object lives on the stack and it's address is passed to the
|
|
// runtime function.
|
|
Address AI = CGF.CreateMemTemp(ThrowType);
|
|
CGF.EmitAnyExprToMem(SubExpr, AI, ThrowType.getQualifiers(),
|
|
/*IsInit=*/true);
|
|
|
|
// The so-called ThrowInfo is used to describe how the exception object may be
|
|
// caught.
|
|
llvm::GlobalVariable *TI = getThrowInfo(ThrowType);
|
|
|
|
// Call into the runtime to throw the exception.
|
|
llvm::Value *Args[] = {
|
|
CGF.Builder.CreateBitCast(AI.getPointer(), CGM.Int8PtrTy),
|
|
TI
|
|
};
|
|
CGF.EmitNoreturnRuntimeCallOrInvoke(getThrowFn(), Args);
|
|
}
|
|
|
|
std::pair<llvm::Value *, const CXXRecordDecl *>
|
|
MicrosoftCXXABI::LoadVTablePtr(CodeGenFunction &CGF, Address This,
|
|
const CXXRecordDecl *RD) {
|
|
std::tie(This, std::ignore, RD) =
|
|
performBaseAdjustment(CGF, This, QualType(RD->getTypeForDecl(), 0));
|
|
return {CGF.GetVTablePtr(This, CGM.Int8PtrTy, RD), RD};
|
|
}
|