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4702 lines
181 KiB
4702 lines
181 KiB
//===------- ItaniumCXXABI.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 Itanium C++ ABI. The class
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// in this file generates structures that follow the Itanium C++ ABI, which is
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// documented at:
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// https://itanium-cxx-abi.github.io/cxx-abi/abi.html
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// https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
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//
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// It also supports the closely-related ARM ABI, documented at:
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// https://developer.arm.com/documentation/ihi0041/g/
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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 "CGRecordLayout.h"
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#include "CGVTables.h"
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#include "CodeGenFunction.h"
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#include "CodeGenModule.h"
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#include "TargetInfo.h"
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#include "clang/AST/Attr.h"
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#include "clang/AST/Mangle.h"
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#include "clang/AST/StmtCXX.h"
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#include "clang/AST/Type.h"
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#include "clang/CodeGen/ConstantInitBuilder.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/GlobalValue.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/Value.h"
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#include "llvm/Support/ScopedPrinter.h"
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using namespace clang;
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using namespace CodeGen;
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namespace {
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class ItaniumCXXABI : public CodeGen::CGCXXABI {
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/// VTables - All the vtables which have been defined.
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llvm::DenseMap<const CXXRecordDecl *, llvm::GlobalVariable *> VTables;
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/// All the thread wrapper functions that have been used.
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llvm::SmallVector<std::pair<const VarDecl *, llvm::Function *>, 8>
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ThreadWrappers;
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protected:
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bool UseARMMethodPtrABI;
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bool UseARMGuardVarABI;
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bool Use32BitVTableOffsetABI;
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ItaniumMangleContext &getMangleContext() {
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return cast<ItaniumMangleContext>(CodeGen::CGCXXABI::getMangleContext());
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}
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public:
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ItaniumCXXABI(CodeGen::CodeGenModule &CGM,
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bool UseARMMethodPtrABI = false,
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bool UseARMGuardVarABI = false) :
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CGCXXABI(CGM), UseARMMethodPtrABI(UseARMMethodPtrABI),
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UseARMGuardVarABI(UseARMGuardVarABI),
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Use32BitVTableOffsetABI(false) { }
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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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// If C++ prohibits us from making a copy, pass by address.
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if (!RD->canPassInRegisters())
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return RAA_Indirect;
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return RAA_Default;
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}
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bool isThisCompleteObject(GlobalDecl GD) const override {
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// The Itanium ABI has separate complete-object vs. base-object
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// variants of both constructors and 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:
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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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if (isa<CXXConstructorDecl>(GD.getDecl())) {
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switch (GD.getCtorType()) {
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case Ctor_Complete:
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return true;
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case Ctor_Base:
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return false;
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case Ctor_CopyingClosure:
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case Ctor_DefaultClosure:
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llvm_unreachable("closure ctors in Itanium ABI?");
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case Ctor_Comdat:
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llvm_unreachable("emitting ctor 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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bool isZeroInitializable(const MemberPointerType *MPT) override;
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llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
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CGCallee
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EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
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const Expr *E,
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Address This,
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llvm::Value *&ThisPtrForCall,
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llvm::Value *MemFnPtr,
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const MemberPointerType *MPT) override;
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llvm::Value *
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EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
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Address Base,
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llvm::Value *MemPtr,
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const MemberPointerType *MPT) override;
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llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
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const CastExpr *E,
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llvm::Value *Src) override;
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llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
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llvm::Constant *Src) override;
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llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
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llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
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llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
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CharUnits offset) override;
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llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
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llvm::Constant *BuildMemberPointer(const CXXMethodDecl *MD,
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CharUnits ThisAdjustment);
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llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
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llvm::Value *L, llvm::Value *R,
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const MemberPointerType *MPT,
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bool Inequality) override;
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llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
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llvm::Value *Addr,
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const MemberPointerType *MPT) override;
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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::CallInst *
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emitTerminateForUnexpectedException(CodeGenFunction &CGF,
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llvm::Value *Exn) override;
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void EmitFundamentalRTTIDescriptors(const CXXRecordDecl *RD);
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llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
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CatchTypeInfo
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getAddrOfCXXCatchHandlerType(QualType Ty,
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QualType CatchHandlerType) override {
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return CatchTypeInfo{getAddrOfRTTIDescriptor(Ty), 0};
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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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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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void EmitCXXConstructors(const CXXConstructorDecl *D) override;
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AddedStructorArgCounts
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buildStructorSignature(GlobalDecl GD,
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SmallVectorImpl<CanQualType> &ArgTys) override;
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bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
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CXXDtorType DT) const override {
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// Itanium does not emit any destructor variant as an inline thunk.
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// Delegating may occur as an optimization, but all variants are either
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// emitted with external linkage or as linkonce if they are inline and used.
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return false;
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}
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void EmitCXXDestructors(const CXXDestructorDecl *D) 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 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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bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
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return true;
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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::Value *getVTableAddressPointInStructorWithVTT(
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CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
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BaseSubobject Base, const CXXRecordDecl *NearestVBase);
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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 emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
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bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override;
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bool canSpeculativelyEmitVTableAsBaseClass(const CXXRecordDecl *RD) const;
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void setThunkLinkage(llvm::Function *Thunk, bool ForVTable, GlobalDecl GD,
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bool ReturnAdjustment) override {
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// Allow inlining of thunks by emitting them with available_externally
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// linkage together with vtables when needed.
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if (ForVTable && !Thunk->hasLocalLinkage())
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Thunk->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
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CGM.setGVProperties(Thunk, GD);
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}
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bool exportThunk() override { return true; }
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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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size_t getSrcArgforCopyCtor(const CXXConstructorDecl *,
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FunctionArgList &Args) const override {
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assert(!Args.empty() && "expected the arglist to not be empty!");
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return Args.size() - 1;
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}
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StringRef GetPureVirtualCallName() override { return "__cxa_pure_virtual"; }
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StringRef GetDeletedVirtualCallName() override
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{ return "__cxa_deleted_virtual"; }
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CharUnits getArrayCookieSizeImpl(QualType elementType) 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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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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llvm::Function *getOrCreateThreadLocalWrapper(const VarDecl *VD,
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llvm::Value *Val);
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void EmitThreadLocalInitFuncs(
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CodeGenModule &CGM,
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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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/// Determine whether we will definitely emit this variable with a constant
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/// initializer, either because the language semantics demand it or because
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/// we know that the initializer is a constant.
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bool isEmittedWithConstantInitializer(const VarDecl *VD) const {
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VD = VD->getMostRecentDecl();
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if (VD->hasAttr<ConstInitAttr>())
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return true;
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// All later checks examine the initializer specified on the variable. If
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// the variable is weak, such examination would not be correct.
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if (VD->isWeak() || VD->hasAttr<SelectAnyAttr>())
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return false;
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const VarDecl *InitDecl = VD->getInitializingDeclaration();
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if (!InitDecl)
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return false;
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// If there's no initializer to run, this is constant initialization.
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if (!InitDecl->hasInit())
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return true;
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// If we have the only definition, we don't need a thread wrapper if we
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// will emit the value as a constant.
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if (isUniqueGVALinkage(getContext().GetGVALinkageForVariable(VD)))
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return !VD->needsDestruction(getContext()) && InitDecl->evaluateValue();
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// Otherwise, we need a thread wrapper unless we know that every
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// translation unit will emit the value as a constant. We rely on the
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// variable being constant-initialized in every translation unit if it's
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// constant-initialized in any translation unit, which isn't actually
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// guaranteed by the standard but is necessary for sanity.
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return InitDecl->hasConstantInitialization();
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}
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bool usesThreadWrapperFunction(const VarDecl *VD) const override {
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return !isEmittedWithConstantInitializer(VD) ||
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VD->needsDestruction(getContext());
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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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bool NeedsVTTParameter(GlobalDecl GD) override;
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/**************************** RTTI Uniqueness ******************************/
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protected:
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/// Returns true if the ABI requires RTTI type_info objects to be unique
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/// across a program.
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virtual bool shouldRTTIBeUnique() const { return true; }
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public:
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/// What sort of unique-RTTI behavior should we use?
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enum RTTIUniquenessKind {
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/// We are guaranteeing, or need to guarantee, that the RTTI string
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/// is unique.
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RUK_Unique,
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/// We are not guaranteeing uniqueness for the RTTI string, so we
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/// can demote to hidden visibility but must use string comparisons.
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RUK_NonUniqueHidden,
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/// We are not guaranteeing uniqueness for the RTTI string, so we
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/// have to use string comparisons, but we also have to emit it with
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/// non-hidden visibility.
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RUK_NonUniqueVisible
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};
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/// Return the required visibility status for the given type and linkage in
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/// the current ABI.
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RTTIUniquenessKind
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classifyRTTIUniqueness(QualType CanTy,
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llvm::GlobalValue::LinkageTypes Linkage) const;
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friend class ItaniumRTTIBuilder;
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void emitCXXStructor(GlobalDecl GD) override;
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std::pair<llvm::Value *, const CXXRecordDecl *>
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LoadVTablePtr(CodeGenFunction &CGF, Address This,
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const CXXRecordDecl *RD) override;
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private:
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bool hasAnyUnusedVirtualInlineFunction(const CXXRecordDecl *RD) const {
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const auto &VtableLayout =
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CGM.getItaniumVTableContext().getVTableLayout(RD);
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for (const auto &VtableComponent : VtableLayout.vtable_components()) {
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// Skip empty slot.
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if (!VtableComponent.isUsedFunctionPointerKind())
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continue;
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const CXXMethodDecl *Method = VtableComponent.getFunctionDecl();
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if (!Method->getCanonicalDecl()->isInlined())
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continue;
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StringRef Name = CGM.getMangledName(VtableComponent.getGlobalDecl());
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auto *Entry = CGM.GetGlobalValue(Name);
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// This checks if virtual inline function has already been emitted.
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// Note that it is possible that this inline function would be emitted
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// after trying to emit vtable speculatively. Because of this we do
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// an extra pass after emitting all deferred vtables to find and emit
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// these vtables opportunistically.
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if (!Entry || Entry->isDeclaration())
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return true;
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}
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return false;
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}
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|
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bool isVTableHidden(const CXXRecordDecl *RD) const {
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const auto &VtableLayout =
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CGM.getItaniumVTableContext().getVTableLayout(RD);
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for (const auto &VtableComponent : VtableLayout.vtable_components()) {
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if (VtableComponent.isRTTIKind()) {
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const CXXRecordDecl *RTTIDecl = VtableComponent.getRTTIDecl();
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if (RTTIDecl->getVisibility() == Visibility::HiddenVisibility)
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return true;
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} else if (VtableComponent.isUsedFunctionPointerKind()) {
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const CXXMethodDecl *Method = VtableComponent.getFunctionDecl();
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if (Method->getVisibility() == Visibility::HiddenVisibility &&
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!Method->isDefined())
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return true;
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}
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}
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return false;
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}
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};
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|
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class ARMCXXABI : public ItaniumCXXABI {
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public:
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ARMCXXABI(CodeGen::CodeGenModule &CGM) :
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ItaniumCXXABI(CGM, /*UseARMMethodPtrABI=*/true,
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/*UseARMGuardVarABI=*/true) {}
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|
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bool HasThisReturn(GlobalDecl GD) const override {
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return (isa<CXXConstructorDecl>(GD.getDecl()) || (
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isa<CXXDestructorDecl>(GD.getDecl()) &&
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GD.getDtorType() != Dtor_Deleting));
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}
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void EmitReturnFromThunk(CodeGenFunction &CGF, RValue RV,
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QualType ResTy) override;
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CharUnits getArrayCookieSizeImpl(QualType elementType) 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, Address allocPtr,
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CharUnits cookieSize) override;
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};
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|
|
|
class AppleARM64CXXABI : public ARMCXXABI {
|
|
public:
|
|
AppleARM64CXXABI(CodeGen::CodeGenModule &CGM) : ARMCXXABI(CGM) {
|
|
Use32BitVTableOffsetABI = true;
|
|
}
|
|
|
|
// ARM64 libraries are prepared for non-unique RTTI.
|
|
bool shouldRTTIBeUnique() const override { return false; }
|
|
};
|
|
|
|
class FuchsiaCXXABI final : public ItaniumCXXABI {
|
|
public:
|
|
explicit FuchsiaCXXABI(CodeGen::CodeGenModule &CGM)
|
|
: ItaniumCXXABI(CGM) {}
|
|
|
|
private:
|
|
bool HasThisReturn(GlobalDecl GD) const override {
|
|
return isa<CXXConstructorDecl>(GD.getDecl()) ||
|
|
(isa<CXXDestructorDecl>(GD.getDecl()) &&
|
|
GD.getDtorType() != Dtor_Deleting);
|
|
}
|
|
};
|
|
|
|
class WebAssemblyCXXABI final : public ItaniumCXXABI {
|
|
public:
|
|
explicit WebAssemblyCXXABI(CodeGen::CodeGenModule &CGM)
|
|
: ItaniumCXXABI(CGM, /*UseARMMethodPtrABI=*/true,
|
|
/*UseARMGuardVarABI=*/true) {}
|
|
void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
|
|
|
|
private:
|
|
bool HasThisReturn(GlobalDecl GD) const override {
|
|
return isa<CXXConstructorDecl>(GD.getDecl()) ||
|
|
(isa<CXXDestructorDecl>(GD.getDecl()) &&
|
|
GD.getDtorType() != Dtor_Deleting);
|
|
}
|
|
bool canCallMismatchedFunctionType() const override { return false; }
|
|
};
|
|
|
|
class XLCXXABI final : public ItaniumCXXABI {
|
|
public:
|
|
explicit XLCXXABI(CodeGen::CodeGenModule &CGM)
|
|
: ItaniumCXXABI(CGM) {}
|
|
|
|
void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
|
|
llvm::FunctionCallee dtor,
|
|
llvm::Constant *addr) override;
|
|
|
|
bool useSinitAndSterm() const override { return true; }
|
|
|
|
private:
|
|
void emitCXXStermFinalizer(const VarDecl &D, llvm::Function *dtorStub,
|
|
llvm::Constant *addr);
|
|
};
|
|
}
|
|
|
|
CodeGen::CGCXXABI *CodeGen::CreateItaniumCXXABI(CodeGenModule &CGM) {
|
|
switch (CGM.getTarget().getCXXABI().getKind()) {
|
|
// For IR-generation purposes, there's no significant difference
|
|
// between the ARM and iOS ABIs.
|
|
case TargetCXXABI::GenericARM:
|
|
case TargetCXXABI::iOS:
|
|
case TargetCXXABI::WatchOS:
|
|
return new ARMCXXABI(CGM);
|
|
|
|
case TargetCXXABI::AppleARM64:
|
|
return new AppleARM64CXXABI(CGM);
|
|
|
|
case TargetCXXABI::Fuchsia:
|
|
return new FuchsiaCXXABI(CGM);
|
|
|
|
// Note that AArch64 uses the generic ItaniumCXXABI class since it doesn't
|
|
// include the other 32-bit ARM oddities: constructor/destructor return values
|
|
// and array cookies.
|
|
case TargetCXXABI::GenericAArch64:
|
|
return new ItaniumCXXABI(CGM, /*UseARMMethodPtrABI=*/true,
|
|
/*UseARMGuardVarABI=*/true);
|
|
|
|
case TargetCXXABI::GenericMIPS:
|
|
return new ItaniumCXXABI(CGM, /*UseARMMethodPtrABI=*/true);
|
|
|
|
case TargetCXXABI::WebAssembly:
|
|
return new WebAssemblyCXXABI(CGM);
|
|
|
|
case TargetCXXABI::XL:
|
|
return new XLCXXABI(CGM);
|
|
|
|
case TargetCXXABI::GenericItanium:
|
|
if (CGM.getContext().getTargetInfo().getTriple().getArch()
|
|
== llvm::Triple::le32) {
|
|
// For PNaCl, use ARM-style method pointers so that PNaCl code
|
|
// does not assume anything about the alignment of function
|
|
// pointers.
|
|
return new ItaniumCXXABI(CGM, /*UseARMMethodPtrABI=*/true);
|
|
}
|
|
return new ItaniumCXXABI(CGM);
|
|
|
|
case TargetCXXABI::Microsoft:
|
|
llvm_unreachable("Microsoft ABI is not Itanium-based");
|
|
}
|
|
llvm_unreachable("bad ABI kind");
|
|
}
|
|
|
|
llvm::Type *
|
|
ItaniumCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
|
|
if (MPT->isMemberDataPointer())
|
|
return CGM.PtrDiffTy;
|
|
return llvm::StructType::get(CGM.PtrDiffTy, CGM.PtrDiffTy);
|
|
}
|
|
|
|
/// In the Itanium and ARM ABIs, method pointers have the form:
|
|
/// struct { ptrdiff_t ptr; ptrdiff_t adj; } memptr;
|
|
///
|
|
/// In the Itanium ABI:
|
|
/// - method pointers are virtual if (memptr.ptr & 1) is nonzero
|
|
/// - the this-adjustment is (memptr.adj)
|
|
/// - the virtual offset is (memptr.ptr - 1)
|
|
///
|
|
/// In the ARM ABI:
|
|
/// - method pointers are virtual if (memptr.adj & 1) is nonzero
|
|
/// - the this-adjustment is (memptr.adj >> 1)
|
|
/// - the virtual offset is (memptr.ptr)
|
|
/// ARM uses 'adj' for the virtual flag because Thumb functions
|
|
/// may be only single-byte aligned.
|
|
///
|
|
/// If the member is virtual, the adjusted 'this' pointer points
|
|
/// to a vtable pointer from which the virtual offset is applied.
|
|
///
|
|
/// If the member is non-virtual, memptr.ptr is the address of
|
|
/// the function to call.
|
|
CGCallee ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(
|
|
CodeGenFunction &CGF, const Expr *E, Address ThisAddr,
|
|
llvm::Value *&ThisPtrForCall,
|
|
llvm::Value *MemFnPtr, const MemberPointerType *MPT) {
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
|
|
const FunctionProtoType *FPT =
|
|
MPT->getPointeeType()->getAs<FunctionProtoType>();
|
|
auto *RD =
|
|
cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl());
|
|
|
|
llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
|
|
CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
|
|
|
|
llvm::Constant *ptrdiff_1 = llvm::ConstantInt::get(CGM.PtrDiffTy, 1);
|
|
|
|
llvm::BasicBlock *FnVirtual = CGF.createBasicBlock("memptr.virtual");
|
|
llvm::BasicBlock *FnNonVirtual = CGF.createBasicBlock("memptr.nonvirtual");
|
|
llvm::BasicBlock *FnEnd = CGF.createBasicBlock("memptr.end");
|
|
|
|
// Extract memptr.adj, which is in the second field.
|
|
llvm::Value *RawAdj = Builder.CreateExtractValue(MemFnPtr, 1, "memptr.adj");
|
|
|
|
// Compute the true adjustment.
|
|
llvm::Value *Adj = RawAdj;
|
|
if (UseARMMethodPtrABI)
|
|
Adj = Builder.CreateAShr(Adj, ptrdiff_1, "memptr.adj.shifted");
|
|
|
|
// Apply the adjustment and cast back to the original struct type
|
|
// for consistency.
|
|
llvm::Value *This = ThisAddr.getPointer();
|
|
llvm::Value *Ptr = Builder.CreateBitCast(This, Builder.getInt8PtrTy());
|
|
Ptr = Builder.CreateInBoundsGEP(Ptr, Adj);
|
|
This = Builder.CreateBitCast(Ptr, This->getType(), "this.adjusted");
|
|
ThisPtrForCall = This;
|
|
|
|
// Load the function pointer.
|
|
llvm::Value *FnAsInt = Builder.CreateExtractValue(MemFnPtr, 0, "memptr.ptr");
|
|
|
|
// If the LSB in the function pointer is 1, the function pointer points to
|
|
// a virtual function.
|
|
llvm::Value *IsVirtual;
|
|
if (UseARMMethodPtrABI)
|
|
IsVirtual = Builder.CreateAnd(RawAdj, ptrdiff_1);
|
|
else
|
|
IsVirtual = Builder.CreateAnd(FnAsInt, ptrdiff_1);
|
|
IsVirtual = Builder.CreateIsNotNull(IsVirtual, "memptr.isvirtual");
|
|
Builder.CreateCondBr(IsVirtual, FnVirtual, FnNonVirtual);
|
|
|
|
// In the virtual path, the adjustment left 'This' pointing to the
|
|
// vtable of the correct base subobject. The "function pointer" is an
|
|
// offset within the vtable (+1 for the virtual flag on non-ARM).
|
|
CGF.EmitBlock(FnVirtual);
|
|
|
|
// Cast the adjusted this to a pointer to vtable pointer and load.
|
|
llvm::Type *VTableTy = Builder.getInt8PtrTy();
|
|
CharUnits VTablePtrAlign =
|
|
CGF.CGM.getDynamicOffsetAlignment(ThisAddr.getAlignment(), RD,
|
|
CGF.getPointerAlign());
|
|
llvm::Value *VTable =
|
|
CGF.GetVTablePtr(Address(This, VTablePtrAlign), VTableTy, RD);
|
|
|
|
// Apply the offset.
|
|
// On ARM64, to reserve extra space in virtual member function pointers,
|
|
// we only pay attention to the low 32 bits of the offset.
|
|
llvm::Value *VTableOffset = FnAsInt;
|
|
if (!UseARMMethodPtrABI)
|
|
VTableOffset = Builder.CreateSub(VTableOffset, ptrdiff_1);
|
|
if (Use32BitVTableOffsetABI) {
|
|
VTableOffset = Builder.CreateTrunc(VTableOffset, CGF.Int32Ty);
|
|
VTableOffset = Builder.CreateZExt(VTableOffset, CGM.PtrDiffTy);
|
|
}
|
|
|
|
// Check the address of the function pointer if CFI on member function
|
|
// pointers is enabled.
|
|
llvm::Constant *CheckSourceLocation;
|
|
llvm::Constant *CheckTypeDesc;
|
|
bool ShouldEmitCFICheck = CGF.SanOpts.has(SanitizerKind::CFIMFCall) &&
|
|
CGM.HasHiddenLTOVisibility(RD);
|
|
bool ShouldEmitVFEInfo = CGM.getCodeGenOpts().VirtualFunctionElimination &&
|
|
CGM.HasHiddenLTOVisibility(RD);
|
|
bool ShouldEmitWPDInfo =
|
|
CGM.getCodeGenOpts().WholeProgramVTables &&
|
|
// Don't insert type tests if we are forcing public std visibility.
|
|
!CGM.HasLTOVisibilityPublicStd(RD);
|
|
llvm::Value *VirtualFn = nullptr;
|
|
|
|
{
|
|
CodeGenFunction::SanitizerScope SanScope(&CGF);
|
|
llvm::Value *TypeId = nullptr;
|
|
llvm::Value *CheckResult = nullptr;
|
|
|
|
if (ShouldEmitCFICheck || ShouldEmitVFEInfo || ShouldEmitWPDInfo) {
|
|
// If doing CFI, VFE or WPD, we will need the metadata node to check
|
|
// against.
|
|
llvm::Metadata *MD =
|
|
CGM.CreateMetadataIdentifierForVirtualMemPtrType(QualType(MPT, 0));
|
|
TypeId = llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD);
|
|
}
|
|
|
|
if (ShouldEmitVFEInfo) {
|
|
llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset);
|
|
|
|
// If doing VFE, load from the vtable with a type.checked.load intrinsic
|
|
// call. Note that we use the GEP to calculate the address to load from
|
|
// and pass 0 as the offset to the intrinsic. This is because every
|
|
// vtable slot of the correct type is marked with matching metadata, and
|
|
// we know that the load must be from one of these slots.
|
|
llvm::Value *CheckedLoad = Builder.CreateCall(
|
|
CGM.getIntrinsic(llvm::Intrinsic::type_checked_load),
|
|
{VFPAddr, llvm::ConstantInt::get(CGM.Int32Ty, 0), TypeId});
|
|
CheckResult = Builder.CreateExtractValue(CheckedLoad, 1);
|
|
VirtualFn = Builder.CreateExtractValue(CheckedLoad, 0);
|
|
VirtualFn = Builder.CreateBitCast(VirtualFn, FTy->getPointerTo(),
|
|
"memptr.virtualfn");
|
|
} else {
|
|
// When not doing VFE, emit a normal load, as it allows more
|
|
// optimisations than type.checked.load.
|
|
if (ShouldEmitCFICheck || ShouldEmitWPDInfo) {
|
|
llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset);
|
|
CheckResult = Builder.CreateCall(
|
|
CGM.getIntrinsic(llvm::Intrinsic::type_test),
|
|
{Builder.CreateBitCast(VFPAddr, CGF.Int8PtrTy), TypeId});
|
|
}
|
|
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
VirtualFn = CGF.Builder.CreateCall(
|
|
CGM.getIntrinsic(llvm::Intrinsic::load_relative,
|
|
{VTableOffset->getType()}),
|
|
{VTable, VTableOffset});
|
|
VirtualFn = CGF.Builder.CreateBitCast(VirtualFn, FTy->getPointerTo());
|
|
} else {
|
|
llvm::Value *VFPAddr = CGF.Builder.CreateGEP(VTable, VTableOffset);
|
|
VFPAddr = CGF.Builder.CreateBitCast(
|
|
VFPAddr, FTy->getPointerTo()->getPointerTo());
|
|
VirtualFn = CGF.Builder.CreateAlignedLoad(
|
|
VFPAddr, CGF.getPointerAlign(), "memptr.virtualfn");
|
|
}
|
|
}
|
|
assert(VirtualFn && "Virtual fuction pointer not created!");
|
|
assert((!ShouldEmitCFICheck || !ShouldEmitVFEInfo || !ShouldEmitWPDInfo ||
|
|
CheckResult) &&
|
|
"Check result required but not created!");
|
|
|
|
if (ShouldEmitCFICheck) {
|
|
// If doing CFI, emit the check.
|
|
CheckSourceLocation = CGF.EmitCheckSourceLocation(E->getBeginLoc());
|
|
CheckTypeDesc = CGF.EmitCheckTypeDescriptor(QualType(MPT, 0));
|
|
llvm::Constant *StaticData[] = {
|
|
llvm::ConstantInt::get(CGF.Int8Ty, CodeGenFunction::CFITCK_VMFCall),
|
|
CheckSourceLocation,
|
|
CheckTypeDesc,
|
|
};
|
|
|
|
if (CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIMFCall)) {
|
|
CGF.EmitTrapCheck(CheckResult, SanitizerHandler::CFICheckFail);
|
|
} else {
|
|
llvm::Value *AllVtables = llvm::MetadataAsValue::get(
|
|
CGM.getLLVMContext(),
|
|
llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
|
|
llvm::Value *ValidVtable = Builder.CreateCall(
|
|
CGM.getIntrinsic(llvm::Intrinsic::type_test), {VTable, AllVtables});
|
|
CGF.EmitCheck(std::make_pair(CheckResult, SanitizerKind::CFIMFCall),
|
|
SanitizerHandler::CFICheckFail, StaticData,
|
|
{VTable, ValidVtable});
|
|
}
|
|
|
|
FnVirtual = Builder.GetInsertBlock();
|
|
}
|
|
} // End of sanitizer scope
|
|
|
|
CGF.EmitBranch(FnEnd);
|
|
|
|
// In the non-virtual path, the function pointer is actually a
|
|
// function pointer.
|
|
CGF.EmitBlock(FnNonVirtual);
|
|
llvm::Value *NonVirtualFn =
|
|
Builder.CreateIntToPtr(FnAsInt, FTy->getPointerTo(), "memptr.nonvirtualfn");
|
|
|
|
// Check the function pointer if CFI on member function pointers is enabled.
|
|
if (ShouldEmitCFICheck) {
|
|
CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
|
|
if (RD->hasDefinition()) {
|
|
CodeGenFunction::SanitizerScope SanScope(&CGF);
|
|
|
|
llvm::Constant *StaticData[] = {
|
|
llvm::ConstantInt::get(CGF.Int8Ty, CodeGenFunction::CFITCK_NVMFCall),
|
|
CheckSourceLocation,
|
|
CheckTypeDesc,
|
|
};
|
|
|
|
llvm::Value *Bit = Builder.getFalse();
|
|
llvm::Value *CastedNonVirtualFn =
|
|
Builder.CreateBitCast(NonVirtualFn, CGF.Int8PtrTy);
|
|
for (const CXXRecordDecl *Base : CGM.getMostBaseClasses(RD)) {
|
|
llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(
|
|
getContext().getMemberPointerType(
|
|
MPT->getPointeeType(),
|
|
getContext().getRecordType(Base).getTypePtr()));
|
|
llvm::Value *TypeId =
|
|
llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD);
|
|
|
|
llvm::Value *TypeTest =
|
|
Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
|
|
{CastedNonVirtualFn, TypeId});
|
|
Bit = Builder.CreateOr(Bit, TypeTest);
|
|
}
|
|
|
|
CGF.EmitCheck(std::make_pair(Bit, SanitizerKind::CFIMFCall),
|
|
SanitizerHandler::CFICheckFail, StaticData,
|
|
{CastedNonVirtualFn, llvm::UndefValue::get(CGF.IntPtrTy)});
|
|
|
|
FnNonVirtual = Builder.GetInsertBlock();
|
|
}
|
|
}
|
|
|
|
// We're done.
|
|
CGF.EmitBlock(FnEnd);
|
|
llvm::PHINode *CalleePtr = Builder.CreatePHI(FTy->getPointerTo(), 2);
|
|
CalleePtr->addIncoming(VirtualFn, FnVirtual);
|
|
CalleePtr->addIncoming(NonVirtualFn, FnNonVirtual);
|
|
|
|
CGCallee Callee(FPT, CalleePtr);
|
|
return Callee;
|
|
}
|
|
|
|
/// Compute an l-value by applying the given pointer-to-member to a
|
|
/// base object.
|
|
llvm::Value *ItaniumCXXABI::EmitMemberDataPointerAddress(
|
|
CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) {
|
|
assert(MemPtr->getType() == CGM.PtrDiffTy);
|
|
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
|
|
// Cast to char*.
|
|
Base = Builder.CreateElementBitCast(Base, CGF.Int8Ty);
|
|
|
|
// Apply the offset, which we assume is non-null.
|
|
llvm::Value *Addr =
|
|
Builder.CreateInBoundsGEP(Base.getPointer(), MemPtr, "memptr.offset");
|
|
|
|
// Cast the address to the appropriate pointer type, adopting the
|
|
// address space of the base pointer.
|
|
llvm::Type *PType = CGF.ConvertTypeForMem(MPT->getPointeeType())
|
|
->getPointerTo(Base.getAddressSpace());
|
|
return Builder.CreateBitCast(Addr, PType);
|
|
}
|
|
|
|
/// Perform a bitcast, derived-to-base, or base-to-derived member pointer
|
|
/// conversion.
|
|
///
|
|
/// Bitcast conversions are always a no-op under Itanium.
|
|
///
|
|
/// Obligatory offset/adjustment diagram:
|
|
/// <-- offset --> <-- adjustment -->
|
|
/// |--------------------------|----------------------|--------------------|
|
|
/// ^Derived address point ^Base address point ^Member address point
|
|
///
|
|
/// So when converting a base member pointer to a derived member pointer,
|
|
/// we add the offset to the adjustment because the address point has
|
|
/// decreased; and conversely, when converting a derived MP to a base MP
|
|
/// we subtract the offset from the adjustment because the address point
|
|
/// has increased.
|
|
///
|
|
/// The standard forbids (at compile time) conversion to and from
|
|
/// virtual bases, which is why we don't have to consider them here.
|
|
///
|
|
/// The standard forbids (at run time) casting a derived MP to a base
|
|
/// MP when the derived MP does not point to a member of the base.
|
|
/// This is why -1 is a reasonable choice for null data member
|
|
/// pointers.
|
|
llvm::Value *
|
|
ItaniumCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
|
|
const CastExpr *E,
|
|
llvm::Value *src) {
|
|
assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
|
|
E->getCastKind() == CK_BaseToDerivedMemberPointer ||
|
|
E->getCastKind() == CK_ReinterpretMemberPointer);
|
|
|
|
// Under Itanium, reinterprets don't require any additional processing.
|
|
if (E->getCastKind() == CK_ReinterpretMemberPointer) return src;
|
|
|
|
// Use constant emission if we can.
|
|
if (isa<llvm::Constant>(src))
|
|
return EmitMemberPointerConversion(E, cast<llvm::Constant>(src));
|
|
|
|
llvm::Constant *adj = getMemberPointerAdjustment(E);
|
|
if (!adj) return src;
|
|
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
bool isDerivedToBase = (E->getCastKind() == CK_DerivedToBaseMemberPointer);
|
|
|
|
const MemberPointerType *destTy =
|
|
E->getType()->castAs<MemberPointerType>();
|
|
|
|
// For member data pointers, this is just a matter of adding the
|
|
// offset if the source is non-null.
|
|
if (destTy->isMemberDataPointer()) {
|
|
llvm::Value *dst;
|
|
if (isDerivedToBase)
|
|
dst = Builder.CreateNSWSub(src, adj, "adj");
|
|
else
|
|
dst = Builder.CreateNSWAdd(src, adj, "adj");
|
|
|
|
// Null check.
|
|
llvm::Value *null = llvm::Constant::getAllOnesValue(src->getType());
|
|
llvm::Value *isNull = Builder.CreateICmpEQ(src, null, "memptr.isnull");
|
|
return Builder.CreateSelect(isNull, src, dst);
|
|
}
|
|
|
|
// The this-adjustment is left-shifted by 1 on ARM.
|
|
if (UseARMMethodPtrABI) {
|
|
uint64_t offset = cast<llvm::ConstantInt>(adj)->getZExtValue();
|
|
offset <<= 1;
|
|
adj = llvm::ConstantInt::get(adj->getType(), offset);
|
|
}
|
|
|
|
llvm::Value *srcAdj = Builder.CreateExtractValue(src, 1, "src.adj");
|
|
llvm::Value *dstAdj;
|
|
if (isDerivedToBase)
|
|
dstAdj = Builder.CreateNSWSub(srcAdj, adj, "adj");
|
|
else
|
|
dstAdj = Builder.CreateNSWAdd(srcAdj, adj, "adj");
|
|
|
|
return Builder.CreateInsertValue(src, dstAdj, 1);
|
|
}
|
|
|
|
llvm::Constant *
|
|
ItaniumCXXABI::EmitMemberPointerConversion(const CastExpr *E,
|
|
llvm::Constant *src) {
|
|
assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
|
|
E->getCastKind() == CK_BaseToDerivedMemberPointer ||
|
|
E->getCastKind() == CK_ReinterpretMemberPointer);
|
|
|
|
// Under Itanium, reinterprets don't require any additional processing.
|
|
if (E->getCastKind() == CK_ReinterpretMemberPointer) return src;
|
|
|
|
// If the adjustment is trivial, we don't need to do anything.
|
|
llvm::Constant *adj = getMemberPointerAdjustment(E);
|
|
if (!adj) return src;
|
|
|
|
bool isDerivedToBase = (E->getCastKind() == CK_DerivedToBaseMemberPointer);
|
|
|
|
const MemberPointerType *destTy =
|
|
E->getType()->castAs<MemberPointerType>();
|
|
|
|
// For member data pointers, this is just a matter of adding the
|
|
// offset if the source is non-null.
|
|
if (destTy->isMemberDataPointer()) {
|
|
// null maps to null.
|
|
if (src->isAllOnesValue()) return src;
|
|
|
|
if (isDerivedToBase)
|
|
return llvm::ConstantExpr::getNSWSub(src, adj);
|
|
else
|
|
return llvm::ConstantExpr::getNSWAdd(src, adj);
|
|
}
|
|
|
|
// The this-adjustment is left-shifted by 1 on ARM.
|
|
if (UseARMMethodPtrABI) {
|
|
uint64_t offset = cast<llvm::ConstantInt>(adj)->getZExtValue();
|
|
offset <<= 1;
|
|
adj = llvm::ConstantInt::get(adj->getType(), offset);
|
|
}
|
|
|
|
llvm::Constant *srcAdj = llvm::ConstantExpr::getExtractValue(src, 1);
|
|
llvm::Constant *dstAdj;
|
|
if (isDerivedToBase)
|
|
dstAdj = llvm::ConstantExpr::getNSWSub(srcAdj, adj);
|
|
else
|
|
dstAdj = llvm::ConstantExpr::getNSWAdd(srcAdj, adj);
|
|
|
|
return llvm::ConstantExpr::getInsertValue(src, dstAdj, 1);
|
|
}
|
|
|
|
llvm::Constant *
|
|
ItaniumCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
|
|
// Itanium C++ ABI 2.3:
|
|
// A NULL pointer is represented as -1.
|
|
if (MPT->isMemberDataPointer())
|
|
return llvm::ConstantInt::get(CGM.PtrDiffTy, -1ULL, /*isSigned=*/true);
|
|
|
|
llvm::Constant *Zero = llvm::ConstantInt::get(CGM.PtrDiffTy, 0);
|
|
llvm::Constant *Values[2] = { Zero, Zero };
|
|
return llvm::ConstantStruct::getAnon(Values);
|
|
}
|
|
|
|
llvm::Constant *
|
|
ItaniumCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
|
|
CharUnits offset) {
|
|
// Itanium C++ ABI 2.3:
|
|
// A pointer to data member is an offset from the base address of
|
|
// the class object containing it, represented as a ptrdiff_t
|
|
return llvm::ConstantInt::get(CGM.PtrDiffTy, offset.getQuantity());
|
|
}
|
|
|
|
llvm::Constant *
|
|
ItaniumCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
|
|
return BuildMemberPointer(MD, CharUnits::Zero());
|
|
}
|
|
|
|
llvm::Constant *ItaniumCXXABI::BuildMemberPointer(const CXXMethodDecl *MD,
|
|
CharUnits ThisAdjustment) {
|
|
assert(MD->isInstance() && "Member function must not be static!");
|
|
|
|
CodeGenTypes &Types = CGM.getTypes();
|
|
|
|
// Get the function pointer (or index if this is a virtual function).
|
|
llvm::Constant *MemPtr[2];
|
|
if (MD->isVirtual()) {
|
|
uint64_t Index = CGM.getItaniumVTableContext().getMethodVTableIndex(MD);
|
|
uint64_t VTableOffset;
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
// Multiply by 4-byte relative offsets.
|
|
VTableOffset = Index * 4;
|
|
} else {
|
|
const ASTContext &Context = getContext();
|
|
CharUnits PointerWidth = Context.toCharUnitsFromBits(
|
|
Context.getTargetInfo().getPointerWidth(0));
|
|
VTableOffset = Index * PointerWidth.getQuantity();
|
|
}
|
|
|
|
if (UseARMMethodPtrABI) {
|
|
// ARM C++ ABI 3.2.1:
|
|
// This ABI specifies that adj contains twice the this
|
|
// adjustment, plus 1 if the member function is virtual. The
|
|
// least significant bit of adj then makes exactly the same
|
|
// discrimination as the least significant bit of ptr does for
|
|
// Itanium.
|
|
MemPtr[0] = llvm::ConstantInt::get(CGM.PtrDiffTy, VTableOffset);
|
|
MemPtr[1] = llvm::ConstantInt::get(CGM.PtrDiffTy,
|
|
2 * ThisAdjustment.getQuantity() + 1);
|
|
} else {
|
|
// Itanium C++ ABI 2.3:
|
|
// For a virtual function, [the pointer field] is 1 plus the
|
|
// virtual table offset (in bytes) of the function,
|
|
// represented as a ptrdiff_t.
|
|
MemPtr[0] = llvm::ConstantInt::get(CGM.PtrDiffTy, VTableOffset + 1);
|
|
MemPtr[1] = llvm::ConstantInt::get(CGM.PtrDiffTy,
|
|
ThisAdjustment.getQuantity());
|
|
}
|
|
} else {
|
|
const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
|
|
llvm::Type *Ty;
|
|
// Check whether the function has a computable LLVM signature.
|
|
if (Types.isFuncTypeConvertible(FPT)) {
|
|
// The function has a computable LLVM signature; use the correct type.
|
|
Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD));
|
|
} else {
|
|
// Use an arbitrary non-function type to tell GetAddrOfFunction that the
|
|
// function type is incomplete.
|
|
Ty = CGM.PtrDiffTy;
|
|
}
|
|
llvm::Constant *addr = CGM.GetAddrOfFunction(MD, Ty);
|
|
|
|
MemPtr[0] = llvm::ConstantExpr::getPtrToInt(addr, CGM.PtrDiffTy);
|
|
MemPtr[1] = llvm::ConstantInt::get(CGM.PtrDiffTy,
|
|
(UseARMMethodPtrABI ? 2 : 1) *
|
|
ThisAdjustment.getQuantity());
|
|
}
|
|
|
|
return llvm::ConstantStruct::getAnon(MemPtr);
|
|
}
|
|
|
|
llvm::Constant *ItaniumCXXABI::EmitMemberPointer(const APValue &MP,
|
|
QualType MPType) {
|
|
const MemberPointerType *MPT = MPType->castAs<MemberPointerType>();
|
|
const ValueDecl *MPD = MP.getMemberPointerDecl();
|
|
if (!MPD)
|
|
return EmitNullMemberPointer(MPT);
|
|
|
|
CharUnits ThisAdjustment = getContext().getMemberPointerPathAdjustment(MP);
|
|
|
|
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD))
|
|
return BuildMemberPointer(MD, ThisAdjustment);
|
|
|
|
CharUnits FieldOffset =
|
|
getContext().toCharUnitsFromBits(getContext().getFieldOffset(MPD));
|
|
return EmitMemberDataPointer(MPT, ThisAdjustment + FieldOffset);
|
|
}
|
|
|
|
/// The comparison algorithm is pretty easy: the member pointers are
|
|
/// the same if they're either bitwise identical *or* both null.
|
|
///
|
|
/// ARM is different here only because null-ness is more complicated.
|
|
llvm::Value *
|
|
ItaniumCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
|
|
llvm::Value *L,
|
|
llvm::Value *R,
|
|
const MemberPointerType *MPT,
|
|
bool Inequality) {
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
|
|
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;
|
|
}
|
|
|
|
// Member data pointers are easy because there's a unique null
|
|
// value, so it just comes down to bitwise equality.
|
|
if (MPT->isMemberDataPointer())
|
|
return Builder.CreateICmp(Eq, L, R);
|
|
|
|
// For member function pointers, the tautologies are more complex.
|
|
// The Itanium tautology is:
|
|
// (L == R) <==> (L.ptr == R.ptr && (L.ptr == 0 || L.adj == R.adj))
|
|
// The ARM tautology is:
|
|
// (L == R) <==> (L.ptr == R.ptr &&
|
|
// (L.adj == R.adj ||
|
|
// (L.ptr == 0 && ((L.adj|R.adj) & 1) == 0)))
|
|
// The inequality tautologies have exactly the same structure, except
|
|
// applying De Morgan's laws.
|
|
|
|
llvm::Value *LPtr = Builder.CreateExtractValue(L, 0, "lhs.memptr.ptr");
|
|
llvm::Value *RPtr = Builder.CreateExtractValue(R, 0, "rhs.memptr.ptr");
|
|
|
|
// This condition tests whether L.ptr == R.ptr. This must always be
|
|
// true for equality to hold.
|
|
llvm::Value *PtrEq = Builder.CreateICmp(Eq, LPtr, RPtr, "cmp.ptr");
|
|
|
|
// This condition, together with the assumption that L.ptr == R.ptr,
|
|
// tests whether the pointers are both null. ARM imposes an extra
|
|
// condition.
|
|
llvm::Value *Zero = llvm::Constant::getNullValue(LPtr->getType());
|
|
llvm::Value *EqZero = Builder.CreateICmp(Eq, LPtr, Zero, "cmp.ptr.null");
|
|
|
|
// This condition tests whether L.adj == R.adj. If this isn't
|
|
// true, the pointers are unequal unless they're both null.
|
|
llvm::Value *LAdj = Builder.CreateExtractValue(L, 1, "lhs.memptr.adj");
|
|
llvm::Value *RAdj = Builder.CreateExtractValue(R, 1, "rhs.memptr.adj");
|
|
llvm::Value *AdjEq = Builder.CreateICmp(Eq, LAdj, RAdj, "cmp.adj");
|
|
|
|
// Null member function pointers on ARM clear the low bit of Adj,
|
|
// so the zero condition has to check that neither low bit is set.
|
|
if (UseARMMethodPtrABI) {
|
|
llvm::Value *One = llvm::ConstantInt::get(LPtr->getType(), 1);
|
|
|
|
// Compute (l.adj | r.adj) & 1 and test it against zero.
|
|
llvm::Value *OrAdj = Builder.CreateOr(LAdj, RAdj, "or.adj");
|
|
llvm::Value *OrAdjAnd1 = Builder.CreateAnd(OrAdj, One);
|
|
llvm::Value *OrAdjAnd1EqZero = Builder.CreateICmp(Eq, OrAdjAnd1, Zero,
|
|
"cmp.or.adj");
|
|
EqZero = Builder.CreateBinOp(And, EqZero, OrAdjAnd1EqZero);
|
|
}
|
|
|
|
// Tie together all our conditions.
|
|
llvm::Value *Result = Builder.CreateBinOp(Or, EqZero, AdjEq);
|
|
Result = Builder.CreateBinOp(And, PtrEq, Result,
|
|
Inequality ? "memptr.ne" : "memptr.eq");
|
|
return Result;
|
|
}
|
|
|
|
llvm::Value *
|
|
ItaniumCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
|
|
llvm::Value *MemPtr,
|
|
const MemberPointerType *MPT) {
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
|
|
/// For member data pointers, this is just a check against -1.
|
|
if (MPT->isMemberDataPointer()) {
|
|
assert(MemPtr->getType() == CGM.PtrDiffTy);
|
|
llvm::Value *NegativeOne =
|
|
llvm::Constant::getAllOnesValue(MemPtr->getType());
|
|
return Builder.CreateICmpNE(MemPtr, NegativeOne, "memptr.tobool");
|
|
}
|
|
|
|
// In Itanium, a member function pointer is not null if 'ptr' is not null.
|
|
llvm::Value *Ptr = Builder.CreateExtractValue(MemPtr, 0, "memptr.ptr");
|
|
|
|
llvm::Constant *Zero = llvm::ConstantInt::get(Ptr->getType(), 0);
|
|
llvm::Value *Result = Builder.CreateICmpNE(Ptr, Zero, "memptr.tobool");
|
|
|
|
// On ARM, a member function pointer is also non-null if the low bit of 'adj'
|
|
// (the virtual bit) is set.
|
|
if (UseARMMethodPtrABI) {
|
|
llvm::Constant *One = llvm::ConstantInt::get(Ptr->getType(), 1);
|
|
llvm::Value *Adj = Builder.CreateExtractValue(MemPtr, 1, "memptr.adj");
|
|
llvm::Value *VirtualBit = Builder.CreateAnd(Adj, One, "memptr.virtualbit");
|
|
llvm::Value *IsVirtual = Builder.CreateICmpNE(VirtualBit, Zero,
|
|
"memptr.isvirtual");
|
|
Result = Builder.CreateOr(Result, IsVirtual);
|
|
}
|
|
|
|
return Result;
|
|
}
|
|
|
|
bool ItaniumCXXABI::classifyReturnType(CGFunctionInfo &FI) const {
|
|
const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
|
|
if (!RD)
|
|
return false;
|
|
|
|
// If C++ prohibits us from making a copy, return by address.
|
|
if (!RD->canPassInRegisters()) {
|
|
auto Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
|
|
FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/// The Itanium ABI requires non-zero initialization only for data
|
|
/// member pointers, for which '0' is a valid offset.
|
|
bool ItaniumCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
|
|
return MPT->isMemberFunctionPointer();
|
|
}
|
|
|
|
/// The Itanium ABI always places an offset to the complete object
|
|
/// at entry -2 in the vtable.
|
|
void ItaniumCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
|
|
const CXXDeleteExpr *DE,
|
|
Address Ptr,
|
|
QualType ElementType,
|
|
const CXXDestructorDecl *Dtor) {
|
|
bool UseGlobalDelete = DE->isGlobalDelete();
|
|
if (UseGlobalDelete) {
|
|
// Derive the complete-object pointer, which is what we need
|
|
// to pass to the deallocation function.
|
|
|
|
// Grab the vtable pointer as an intptr_t*.
|
|
auto *ClassDecl =
|
|
cast<CXXRecordDecl>(ElementType->castAs<RecordType>()->getDecl());
|
|
llvm::Value *VTable =
|
|
CGF.GetVTablePtr(Ptr, CGF.IntPtrTy->getPointerTo(), ClassDecl);
|
|
|
|
// Track back to entry -2 and pull out the offset there.
|
|
llvm::Value *OffsetPtr = CGF.Builder.CreateConstInBoundsGEP1_64(
|
|
VTable, -2, "complete-offset.ptr");
|
|
llvm::Value *Offset =
|
|
CGF.Builder.CreateAlignedLoad(OffsetPtr, CGF.getPointerAlign());
|
|
|
|
// Apply the offset.
|
|
llvm::Value *CompletePtr =
|
|
CGF.Builder.CreateBitCast(Ptr.getPointer(), CGF.Int8PtrTy);
|
|
CompletePtr = CGF.Builder.CreateInBoundsGEP(CompletePtr, Offset);
|
|
|
|
// If we're supposed to call the global delete, make sure we do so
|
|
// even if the destructor throws.
|
|
CGF.pushCallObjectDeleteCleanup(DE->getOperatorDelete(), CompletePtr,
|
|
ElementType);
|
|
}
|
|
|
|
// FIXME: Provide a source location here even though there's no
|
|
// CXXMemberCallExpr for dtor call.
|
|
CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
|
|
EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
|
|
|
|
if (UseGlobalDelete)
|
|
CGF.PopCleanupBlock();
|
|
}
|
|
|
|
void ItaniumCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
|
|
// void __cxa_rethrow();
|
|
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
|
|
|
|
llvm::FunctionCallee Fn = CGM.CreateRuntimeFunction(FTy, "__cxa_rethrow");
|
|
|
|
if (isNoReturn)
|
|
CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, None);
|
|
else
|
|
CGF.EmitRuntimeCallOrInvoke(Fn);
|
|
}
|
|
|
|
static llvm::FunctionCallee getAllocateExceptionFn(CodeGenModule &CGM) {
|
|
// void *__cxa_allocate_exception(size_t thrown_size);
|
|
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.Int8PtrTy, CGM.SizeTy, /*isVarArg=*/false);
|
|
|
|
return CGM.CreateRuntimeFunction(FTy, "__cxa_allocate_exception");
|
|
}
|
|
|
|
static llvm::FunctionCallee getThrowFn(CodeGenModule &CGM) {
|
|
// void __cxa_throw(void *thrown_exception, std::type_info *tinfo,
|
|
// void (*dest) (void *));
|
|
|
|
llvm::Type *Args[3] = { CGM.Int8PtrTy, CGM.Int8PtrTy, CGM.Int8PtrTy };
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
|
|
|
|
return CGM.CreateRuntimeFunction(FTy, "__cxa_throw");
|
|
}
|
|
|
|
void ItaniumCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
|
|
QualType ThrowType = E->getSubExpr()->getType();
|
|
// Now allocate the exception object.
|
|
llvm::Type *SizeTy = CGF.ConvertType(getContext().getSizeType());
|
|
uint64_t TypeSize = getContext().getTypeSizeInChars(ThrowType).getQuantity();
|
|
|
|
llvm::FunctionCallee AllocExceptionFn = getAllocateExceptionFn(CGM);
|
|
llvm::CallInst *ExceptionPtr = CGF.EmitNounwindRuntimeCall(
|
|
AllocExceptionFn, llvm::ConstantInt::get(SizeTy, TypeSize), "exception");
|
|
|
|
CharUnits ExnAlign = CGF.getContext().getExnObjectAlignment();
|
|
CGF.EmitAnyExprToExn(E->getSubExpr(), Address(ExceptionPtr, ExnAlign));
|
|
|
|
// Now throw the exception.
|
|
llvm::Constant *TypeInfo = CGM.GetAddrOfRTTIDescriptor(ThrowType,
|
|
/*ForEH=*/true);
|
|
|
|
// The address of the destructor. If the exception type has a
|
|
// trivial destructor (or isn't a record), we just pass null.
|
|
llvm::Constant *Dtor = nullptr;
|
|
if (const RecordType *RecordTy = ThrowType->getAs<RecordType>()) {
|
|
CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl());
|
|
if (!Record->hasTrivialDestructor()) {
|
|
CXXDestructorDecl *DtorD = Record->getDestructor();
|
|
Dtor = CGM.getAddrOfCXXStructor(GlobalDecl(DtorD, Dtor_Complete));
|
|
Dtor = llvm::ConstantExpr::getBitCast(Dtor, CGM.Int8PtrTy);
|
|
}
|
|
}
|
|
if (!Dtor) Dtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
|
|
|
|
llvm::Value *args[] = { ExceptionPtr, TypeInfo, Dtor };
|
|
CGF.EmitNoreturnRuntimeCallOrInvoke(getThrowFn(CGM), args);
|
|
}
|
|
|
|
static llvm::FunctionCallee getItaniumDynamicCastFn(CodeGenFunction &CGF) {
|
|
// void *__dynamic_cast(const void *sub,
|
|
// const abi::__class_type_info *src,
|
|
// const abi::__class_type_info *dst,
|
|
// std::ptrdiff_t src2dst_offset);
|
|
|
|
llvm::Type *Int8PtrTy = CGF.Int8PtrTy;
|
|
llvm::Type *PtrDiffTy =
|
|
CGF.ConvertType(CGF.getContext().getPointerDiffType());
|
|
|
|
llvm::Type *Args[4] = { Int8PtrTy, Int8PtrTy, Int8PtrTy, PtrDiffTy };
|
|
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(Int8PtrTy, Args, false);
|
|
|
|
// Mark the function as nounwind readonly.
|
|
llvm::Attribute::AttrKind FuncAttrs[] = { llvm::Attribute::NoUnwind,
|
|
llvm::Attribute::ReadOnly };
|
|
llvm::AttributeList Attrs = llvm::AttributeList::get(
|
|
CGF.getLLVMContext(), llvm::AttributeList::FunctionIndex, FuncAttrs);
|
|
|
|
return CGF.CGM.CreateRuntimeFunction(FTy, "__dynamic_cast", Attrs);
|
|
}
|
|
|
|
static llvm::FunctionCallee getBadCastFn(CodeGenFunction &CGF) {
|
|
// void __cxa_bad_cast();
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false);
|
|
return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_cast");
|
|
}
|
|
|
|
/// Compute the src2dst_offset hint as described in the
|
|
/// Itanium C++ ABI [2.9.7]
|
|
static CharUnits computeOffsetHint(ASTContext &Context,
|
|
const CXXRecordDecl *Src,
|
|
const CXXRecordDecl *Dst) {
|
|
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
|
|
/*DetectVirtual=*/false);
|
|
|
|
// If Dst is not derived from Src we can skip the whole computation below and
|
|
// return that Src is not a public base of Dst. Record all inheritance paths.
|
|
if (!Dst->isDerivedFrom(Src, Paths))
|
|
return CharUnits::fromQuantity(-2ULL);
|
|
|
|
unsigned NumPublicPaths = 0;
|
|
CharUnits Offset;
|
|
|
|
// Now walk all possible inheritance paths.
|
|
for (const CXXBasePath &Path : Paths) {
|
|
if (Path.Access != AS_public) // Ignore non-public inheritance.
|
|
continue;
|
|
|
|
++NumPublicPaths;
|
|
|
|
for (const CXXBasePathElement &PathElement : Path) {
|
|
// If the path contains a virtual base class we can't give any hint.
|
|
// -1: no hint.
|
|
if (PathElement.Base->isVirtual())
|
|
return CharUnits::fromQuantity(-1ULL);
|
|
|
|
if (NumPublicPaths > 1) // Won't use offsets, skip computation.
|
|
continue;
|
|
|
|
// Accumulate the base class offsets.
|
|
const ASTRecordLayout &L = Context.getASTRecordLayout(PathElement.Class);
|
|
Offset += L.getBaseClassOffset(
|
|
PathElement.Base->getType()->getAsCXXRecordDecl());
|
|
}
|
|
}
|
|
|
|
// -2: Src is not a public base of Dst.
|
|
if (NumPublicPaths == 0)
|
|
return CharUnits::fromQuantity(-2ULL);
|
|
|
|
// -3: Src is a multiple public base type but never a virtual base type.
|
|
if (NumPublicPaths > 1)
|
|
return CharUnits::fromQuantity(-3ULL);
|
|
|
|
// Otherwise, the Src type is a unique public nonvirtual base type of Dst.
|
|
// Return the offset of Src from the origin of Dst.
|
|
return Offset;
|
|
}
|
|
|
|
static llvm::FunctionCallee getBadTypeidFn(CodeGenFunction &CGF) {
|
|
// void __cxa_bad_typeid();
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false);
|
|
|
|
return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid");
|
|
}
|
|
|
|
bool ItaniumCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
|
|
QualType SrcRecordTy) {
|
|
return IsDeref;
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
|
|
llvm::FunctionCallee Fn = getBadTypeidFn(CGF);
|
|
llvm::CallBase *Call = CGF.EmitRuntimeCallOrInvoke(Fn);
|
|
Call->setDoesNotReturn();
|
|
CGF.Builder.CreateUnreachable();
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::EmitTypeid(CodeGenFunction &CGF,
|
|
QualType SrcRecordTy,
|
|
Address ThisPtr,
|
|
llvm::Type *StdTypeInfoPtrTy) {
|
|
auto *ClassDecl =
|
|
cast<CXXRecordDecl>(SrcRecordTy->castAs<RecordType>()->getDecl());
|
|
llvm::Value *Value =
|
|
CGF.GetVTablePtr(ThisPtr, StdTypeInfoPtrTy->getPointerTo(), ClassDecl);
|
|
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
// Load the type info.
|
|
Value = CGF.Builder.CreateBitCast(Value, CGM.Int8PtrTy);
|
|
Value = CGF.Builder.CreateCall(
|
|
CGM.getIntrinsic(llvm::Intrinsic::load_relative, {CGM.Int32Ty}),
|
|
{Value, llvm::ConstantInt::get(CGM.Int32Ty, -4)});
|
|
|
|
// Setup to dereference again since this is a proxy we accessed.
|
|
Value = CGF.Builder.CreateBitCast(Value, StdTypeInfoPtrTy->getPointerTo());
|
|
} else {
|
|
// Load the type info.
|
|
Value = CGF.Builder.CreateConstInBoundsGEP1_64(Value, -1ULL);
|
|
}
|
|
return CGF.Builder.CreateAlignedLoad(Value, CGF.getPointerAlign());
|
|
}
|
|
|
|
bool ItaniumCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
|
|
QualType SrcRecordTy) {
|
|
return SrcIsPtr;
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::EmitDynamicCastCall(
|
|
CodeGenFunction &CGF, Address ThisAddr, QualType SrcRecordTy,
|
|
QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
|
|
llvm::Type *PtrDiffLTy =
|
|
CGF.ConvertType(CGF.getContext().getPointerDiffType());
|
|
llvm::Type *DestLTy = CGF.ConvertType(DestTy);
|
|
|
|
llvm::Value *SrcRTTI =
|
|
CGF.CGM.GetAddrOfRTTIDescriptor(SrcRecordTy.getUnqualifiedType());
|
|
llvm::Value *DestRTTI =
|
|
CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
|
|
|
|
// Compute the offset hint.
|
|
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
|
|
const CXXRecordDecl *DestDecl = DestRecordTy->getAsCXXRecordDecl();
|
|
llvm::Value *OffsetHint = llvm::ConstantInt::get(
|
|
PtrDiffLTy,
|
|
computeOffsetHint(CGF.getContext(), SrcDecl, DestDecl).getQuantity());
|
|
|
|
// Emit the call to __dynamic_cast.
|
|
llvm::Value *Value = ThisAddr.getPointer();
|
|
Value = CGF.EmitCastToVoidPtr(Value);
|
|
|
|
llvm::Value *args[] = {Value, SrcRTTI, DestRTTI, OffsetHint};
|
|
Value = CGF.EmitNounwindRuntimeCall(getItaniumDynamicCastFn(CGF), args);
|
|
Value = CGF.Builder.CreateBitCast(Value, DestLTy);
|
|
|
|
/// C++ [expr.dynamic.cast]p9:
|
|
/// A failed cast to reference type throws std::bad_cast
|
|
if (DestTy->isReferenceType()) {
|
|
llvm::BasicBlock *BadCastBlock =
|
|
CGF.createBasicBlock("dynamic_cast.bad_cast");
|
|
|
|
llvm::Value *IsNull = CGF.Builder.CreateIsNull(Value);
|
|
CGF.Builder.CreateCondBr(IsNull, BadCastBlock, CastEnd);
|
|
|
|
CGF.EmitBlock(BadCastBlock);
|
|
EmitBadCastCall(CGF);
|
|
}
|
|
|
|
return Value;
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF,
|
|
Address ThisAddr,
|
|
QualType SrcRecordTy,
|
|
QualType DestTy) {
|
|
llvm::Type *DestLTy = CGF.ConvertType(DestTy);
|
|
auto *ClassDecl =
|
|
cast<CXXRecordDecl>(SrcRecordTy->castAs<RecordType>()->getDecl());
|
|
llvm::Value *OffsetToTop;
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
// Get the vtable pointer.
|
|
llvm::Value *VTable =
|
|
CGF.GetVTablePtr(ThisAddr, CGM.Int32Ty->getPointerTo(), ClassDecl);
|
|
|
|
// Get the offset-to-top from the vtable.
|
|
OffsetToTop =
|
|
CGF.Builder.CreateConstInBoundsGEP1_32(/*Type=*/nullptr, VTable, -2U);
|
|
OffsetToTop = CGF.Builder.CreateAlignedLoad(
|
|
OffsetToTop, CharUnits::fromQuantity(4), "offset.to.top");
|
|
} else {
|
|
llvm::Type *PtrDiffLTy =
|
|
CGF.ConvertType(CGF.getContext().getPointerDiffType());
|
|
|
|
// Get the vtable pointer.
|
|
llvm::Value *VTable =
|
|
CGF.GetVTablePtr(ThisAddr, PtrDiffLTy->getPointerTo(), ClassDecl);
|
|
|
|
// Get the offset-to-top from the vtable.
|
|
OffsetToTop = CGF.Builder.CreateConstInBoundsGEP1_64(VTable, -2ULL);
|
|
OffsetToTop = CGF.Builder.CreateAlignedLoad(
|
|
OffsetToTop, CGF.getPointerAlign(), "offset.to.top");
|
|
}
|
|
// Finally, add the offset to the pointer.
|
|
llvm::Value *Value = ThisAddr.getPointer();
|
|
Value = CGF.EmitCastToVoidPtr(Value);
|
|
Value = CGF.Builder.CreateInBoundsGEP(Value, OffsetToTop);
|
|
return CGF.Builder.CreateBitCast(Value, DestLTy);
|
|
}
|
|
|
|
bool ItaniumCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
|
|
llvm::FunctionCallee Fn = getBadCastFn(CGF);
|
|
llvm::CallBase *Call = CGF.EmitRuntimeCallOrInvoke(Fn);
|
|
Call->setDoesNotReturn();
|
|
CGF.Builder.CreateUnreachable();
|
|
return true;
|
|
}
|
|
|
|
llvm::Value *
|
|
ItaniumCXXABI::GetVirtualBaseClassOffset(CodeGenFunction &CGF,
|
|
Address This,
|
|
const CXXRecordDecl *ClassDecl,
|
|
const CXXRecordDecl *BaseClassDecl) {
|
|
llvm::Value *VTablePtr = CGF.GetVTablePtr(This, CGM.Int8PtrTy, ClassDecl);
|
|
CharUnits VBaseOffsetOffset =
|
|
CGM.getItaniumVTableContext().getVirtualBaseOffsetOffset(ClassDecl,
|
|
BaseClassDecl);
|
|
llvm::Value *VBaseOffsetPtr =
|
|
CGF.Builder.CreateConstGEP1_64(VTablePtr, VBaseOffsetOffset.getQuantity(),
|
|
"vbase.offset.ptr");
|
|
|
|
llvm::Value *VBaseOffset;
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
VBaseOffsetPtr =
|
|
CGF.Builder.CreateBitCast(VBaseOffsetPtr, CGF.Int32Ty->getPointerTo());
|
|
VBaseOffset = CGF.Builder.CreateAlignedLoad(
|
|
VBaseOffsetPtr, CharUnits::fromQuantity(4), "vbase.offset");
|
|
} else {
|
|
VBaseOffsetPtr = CGF.Builder.CreateBitCast(VBaseOffsetPtr,
|
|
CGM.PtrDiffTy->getPointerTo());
|
|
VBaseOffset = CGF.Builder.CreateAlignedLoad(
|
|
VBaseOffsetPtr, CGF.getPointerAlign(), "vbase.offset");
|
|
}
|
|
return VBaseOffset;
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
|
|
// Just make sure we're in sync with TargetCXXABI.
|
|
assert(CGM.getTarget().getCXXABI().hasConstructorVariants());
|
|
|
|
// The constructor used for constructing this as a base class;
|
|
// ignores virtual bases.
|
|
CGM.EmitGlobal(GlobalDecl(D, Ctor_Base));
|
|
|
|
// The constructor used for constructing this as a complete class;
|
|
// constructs the virtual bases, then calls the base constructor.
|
|
if (!D->getParent()->isAbstract()) {
|
|
// We don't need to emit the complete ctor if the class is abstract.
|
|
CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
|
|
}
|
|
}
|
|
|
|
CGCXXABI::AddedStructorArgCounts
|
|
ItaniumCXXABI::buildStructorSignature(GlobalDecl GD,
|
|
SmallVectorImpl<CanQualType> &ArgTys) {
|
|
ASTContext &Context = getContext();
|
|
|
|
// All parameters are already in place except VTT, which goes after 'this'.
|
|
// These are Clang types, so we don't need to worry about sret yet.
|
|
|
|
// Check if we need to add a VTT parameter (which has type void **).
|
|
if ((isa<CXXConstructorDecl>(GD.getDecl()) ? GD.getCtorType() == Ctor_Base
|
|
: GD.getDtorType() == Dtor_Base) &&
|
|
cast<CXXMethodDecl>(GD.getDecl())->getParent()->getNumVBases() != 0) {
|
|
ArgTys.insert(ArgTys.begin() + 1,
|
|
Context.getPointerType(Context.VoidPtrTy));
|
|
return AddedStructorArgCounts::prefix(1);
|
|
}
|
|
return AddedStructorArgCounts{};
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) {
|
|
// The destructor used for destructing this as a base class; ignores
|
|
// virtual bases.
|
|
CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
|
|
|
|
// The destructor used for destructing this as a most-derived class;
|
|
// call the base destructor and then destructs any virtual bases.
|
|
CGM.EmitGlobal(GlobalDecl(D, Dtor_Complete));
|
|
|
|
// The destructor in a virtual table is always a 'deleting'
|
|
// destructor, which calls the complete destructor and then uses the
|
|
// appropriate operator delete.
|
|
if (D->isVirtual())
|
|
CGM.EmitGlobal(GlobalDecl(D, Dtor_Deleting));
|
|
}
|
|
|
|
void ItaniumCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
|
|
QualType &ResTy,
|
|
FunctionArgList &Params) {
|
|
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
|
|
assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
|
|
|
|
// Check if we need a VTT parameter as well.
|
|
if (NeedsVTTParameter(CGF.CurGD)) {
|
|
ASTContext &Context = getContext();
|
|
|
|
// FIXME: avoid the fake decl
|
|
QualType T = Context.getPointerType(Context.VoidPtrTy);
|
|
auto *VTTDecl = ImplicitParamDecl::Create(
|
|
Context, /*DC=*/nullptr, MD->getLocation(), &Context.Idents.get("vtt"),
|
|
T, ImplicitParamDecl::CXXVTT);
|
|
Params.insert(Params.begin() + 1, VTTDecl);
|
|
getStructorImplicitParamDecl(CGF) = VTTDecl;
|
|
}
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
|
|
// Naked functions have no prolog.
|
|
if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
|
|
return;
|
|
|
|
/// Initialize the 'this' slot. In the Itanium C++ ABI, no prologue
|
|
/// adjustments are required, because they are all handled by thunks.
|
|
setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
|
|
|
|
/// Initialize the 'vtt' slot if needed.
|
|
if (getStructorImplicitParamDecl(CGF)) {
|
|
getStructorImplicitParamValue(CGF) = CGF.Builder.CreateLoad(
|
|
CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)), "vtt");
|
|
}
|
|
|
|
/// 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);
|
|
}
|
|
|
|
CGCXXABI::AddedStructorArgs ItaniumCXXABI::getImplicitConstructorArgs(
|
|
CodeGenFunction &CGF, const CXXConstructorDecl *D, CXXCtorType Type,
|
|
bool ForVirtualBase, bool Delegating) {
|
|
if (!NeedsVTTParameter(GlobalDecl(D, Type)))
|
|
return AddedStructorArgs{};
|
|
|
|
// Insert the implicit 'vtt' argument as the second argument.
|
|
llvm::Value *VTT =
|
|
CGF.GetVTTParameter(GlobalDecl(D, Type), ForVirtualBase, Delegating);
|
|
QualType VTTTy = getContext().getPointerType(getContext().VoidPtrTy);
|
|
return AddedStructorArgs::prefix({{VTT, VTTTy}});
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::getCXXDestructorImplicitParam(
|
|
CodeGenFunction &CGF, const CXXDestructorDecl *DD, CXXDtorType Type,
|
|
bool ForVirtualBase, bool Delegating) {
|
|
GlobalDecl GD(DD, Type);
|
|
return CGF.GetVTTParameter(GD, ForVirtualBase, Delegating);
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
|
|
const CXXDestructorDecl *DD,
|
|
CXXDtorType Type, bool ForVirtualBase,
|
|
bool Delegating, Address This,
|
|
QualType ThisTy) {
|
|
GlobalDecl GD(DD, Type);
|
|
llvm::Value *VTT =
|
|
getCXXDestructorImplicitParam(CGF, DD, Type, ForVirtualBase, Delegating);
|
|
QualType VTTTy = getContext().getPointerType(getContext().VoidPtrTy);
|
|
|
|
CGCallee Callee;
|
|
if (getContext().getLangOpts().AppleKext &&
|
|
Type != Dtor_Base && DD->isVirtual())
|
|
Callee = CGF.BuildAppleKextVirtualDestructorCall(DD, Type, DD->getParent());
|
|
else
|
|
Callee = CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD), GD);
|
|
|
|
CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy, VTT, VTTTy,
|
|
nullptr);
|
|
}
|
|
|
|
void ItaniumCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
|
|
const CXXRecordDecl *RD) {
|
|
llvm::GlobalVariable *VTable = getAddrOfVTable(RD, CharUnits());
|
|
if (VTable->hasInitializer())
|
|
return;
|
|
|
|
ItaniumVTableContext &VTContext = CGM.getItaniumVTableContext();
|
|
const VTableLayout &VTLayout = VTContext.getVTableLayout(RD);
|
|
llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
|
|
llvm::Constant *RTTI =
|
|
CGM.GetAddrOfRTTIDescriptor(CGM.getContext().getTagDeclType(RD));
|
|
|
|
// Create and set the initializer.
|
|
ConstantInitBuilder builder(CGM);
|
|
auto components = builder.beginStruct();
|
|
CGVT.createVTableInitializer(components, VTLayout, RTTI,
|
|
llvm::GlobalValue::isLocalLinkage(Linkage));
|
|
components.finishAndSetAsInitializer(VTable);
|
|
|
|
// Set the correct linkage.
|
|
VTable->setLinkage(Linkage);
|
|
|
|
if (CGM.supportsCOMDAT() && VTable->isWeakForLinker())
|
|
VTable->setComdat(CGM.getModule().getOrInsertComdat(VTable->getName()));
|
|
|
|
// Set the right visibility.
|
|
CGM.setGVProperties(VTable, RD);
|
|
|
|
// If this is the magic class __cxxabiv1::__fundamental_type_info,
|
|
// we will emit the typeinfo for the fundamental types. This is the
|
|
// same behaviour as GCC.
|
|
const DeclContext *DC = RD->getDeclContext();
|
|
if (RD->getIdentifier() &&
|
|
RD->getIdentifier()->isStr("__fundamental_type_info") &&
|
|
isa<NamespaceDecl>(DC) && cast<NamespaceDecl>(DC)->getIdentifier() &&
|
|
cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__cxxabiv1") &&
|
|
DC->getParent()->isTranslationUnit())
|
|
EmitFundamentalRTTIDescriptors(RD);
|
|
|
|
if (!VTable->isDeclarationForLinker())
|
|
CGM.EmitVTableTypeMetadata(RD, VTable, VTLayout);
|
|
|
|
if (VTContext.isRelativeLayout() && !VTable->isDSOLocal())
|
|
CGVT.GenerateRelativeVTableAlias(VTable, VTable->getName());
|
|
}
|
|
|
|
bool ItaniumCXXABI::isVirtualOffsetNeededForVTableField(
|
|
CodeGenFunction &CGF, CodeGenFunction::VPtr Vptr) {
|
|
if (Vptr.NearestVBase == nullptr)
|
|
return false;
|
|
return NeedsVTTParameter(CGF.CurGD);
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::getVTableAddressPointInStructor(
|
|
CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
|
|
const CXXRecordDecl *NearestVBase) {
|
|
|
|
if ((Base.getBase()->getNumVBases() || NearestVBase != nullptr) &&
|
|
NeedsVTTParameter(CGF.CurGD)) {
|
|
return getVTableAddressPointInStructorWithVTT(CGF, VTableClass, Base,
|
|
NearestVBase);
|
|
}
|
|
return getVTableAddressPoint(Base, VTableClass);
|
|
}
|
|
|
|
llvm::Constant *
|
|
ItaniumCXXABI::getVTableAddressPoint(BaseSubobject Base,
|
|
const CXXRecordDecl *VTableClass) {
|
|
llvm::GlobalValue *VTable = getAddrOfVTable(VTableClass, CharUnits());
|
|
|
|
// Find the appropriate vtable within the vtable group, and the address point
|
|
// within that vtable.
|
|
VTableLayout::AddressPointLocation AddressPoint =
|
|
CGM.getItaniumVTableContext()
|
|
.getVTableLayout(VTableClass)
|
|
.getAddressPoint(Base);
|
|
llvm::Value *Indices[] = {
|
|
llvm::ConstantInt::get(CGM.Int32Ty, 0),
|
|
llvm::ConstantInt::get(CGM.Int32Ty, AddressPoint.VTableIndex),
|
|
llvm::ConstantInt::get(CGM.Int32Ty, AddressPoint.AddressPointIndex),
|
|
};
|
|
|
|
return llvm::ConstantExpr::getGetElementPtr(VTable->getValueType(), VTable,
|
|
Indices, /*InBounds=*/true,
|
|
/*InRangeIndex=*/1);
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::getVTableAddressPointInStructorWithVTT(
|
|
CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
|
|
const CXXRecordDecl *NearestVBase) {
|
|
assert((Base.getBase()->getNumVBases() || NearestVBase != nullptr) &&
|
|
NeedsVTTParameter(CGF.CurGD) && "This class doesn't have VTT");
|
|
|
|
// Get the secondary vpointer index.
|
|
uint64_t VirtualPointerIndex =
|
|
CGM.getVTables().getSecondaryVirtualPointerIndex(VTableClass, Base);
|
|
|
|
/// Load the VTT.
|
|
llvm::Value *VTT = CGF.LoadCXXVTT();
|
|
if (VirtualPointerIndex)
|
|
VTT = CGF.Builder.CreateConstInBoundsGEP1_64(VTT, VirtualPointerIndex);
|
|
|
|
// And load the address point from the VTT.
|
|
return CGF.Builder.CreateAlignedLoad(VTT, CGF.getPointerAlign());
|
|
}
|
|
|
|
llvm::Constant *ItaniumCXXABI::getVTableAddressPointForConstExpr(
|
|
BaseSubobject Base, const CXXRecordDecl *VTableClass) {
|
|
return getVTableAddressPoint(Base, VTableClass);
|
|
}
|
|
|
|
llvm::GlobalVariable *ItaniumCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
|
|
CharUnits VPtrOffset) {
|
|
assert(VPtrOffset.isZero() && "Itanium ABI only supports zero vptr offsets");
|
|
|
|
llvm::GlobalVariable *&VTable = VTables[RD];
|
|
if (VTable)
|
|
return VTable;
|
|
|
|
// Queue up this vtable for possible deferred emission.
|
|
CGM.addDeferredVTable(RD);
|
|
|
|
SmallString<256> Name;
|
|
llvm::raw_svector_ostream Out(Name);
|
|
getMangleContext().mangleCXXVTable(RD, Out);
|
|
|
|
const VTableLayout &VTLayout =
|
|
CGM.getItaniumVTableContext().getVTableLayout(RD);
|
|
llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
|
|
|
|
// Use pointer alignment for the vtable. Otherwise we would align them based
|
|
// on the size of the initializer which doesn't make sense as only single
|
|
// values are read.
|
|
unsigned PAlign = CGM.getItaniumVTableContext().isRelativeLayout()
|
|
? 32
|
|
: CGM.getTarget().getPointerAlign(0);
|
|
|
|
VTable = CGM.CreateOrReplaceCXXRuntimeVariable(
|
|
Name, VTableType, llvm::GlobalValue::ExternalLinkage,
|
|
getContext().toCharUnitsFromBits(PAlign).getQuantity());
|
|
VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
|
|
CGM.setGVProperties(VTable, RD);
|
|
|
|
return VTable;
|
|
}
|
|
|
|
CGCallee ItaniumCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
|
|
GlobalDecl GD,
|
|
Address This,
|
|
llvm::Type *Ty,
|
|
SourceLocation Loc) {
|
|
auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
|
|
llvm::Value *VTable = CGF.GetVTablePtr(
|
|
This, Ty->getPointerTo()->getPointerTo(), MethodDecl->getParent());
|
|
|
|
uint64_t VTableIndex = CGM.getItaniumVTableContext().getMethodVTableIndex(GD);
|
|
llvm::Value *VFunc;
|
|
if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
|
|
VFunc = CGF.EmitVTableTypeCheckedLoad(
|
|
MethodDecl->getParent(), VTable,
|
|
VTableIndex * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
|
|
} else {
|
|
CGF.EmitTypeMetadataCodeForVCall(MethodDecl->getParent(), VTable, Loc);
|
|
|
|
llvm::Value *VFuncLoad;
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
VTable = CGF.Builder.CreateBitCast(VTable, CGM.Int8PtrTy);
|
|
llvm::Value *Load = CGF.Builder.CreateCall(
|
|
CGM.getIntrinsic(llvm::Intrinsic::load_relative, {CGM.Int32Ty}),
|
|
{VTable, llvm::ConstantInt::get(CGM.Int32Ty, 4 * VTableIndex)});
|
|
VFuncLoad = CGF.Builder.CreateBitCast(Load, Ty->getPointerTo());
|
|
} else {
|
|
VTable =
|
|
CGF.Builder.CreateBitCast(VTable, Ty->getPointerTo()->getPointerTo());
|
|
llvm::Value *VTableSlotPtr =
|
|
CGF.Builder.CreateConstInBoundsGEP1_64(VTable, VTableIndex, "vfn");
|
|
VFuncLoad =
|
|
CGF.Builder.CreateAlignedLoad(VTableSlotPtr, CGF.getPointerAlign());
|
|
}
|
|
|
|
// Add !invariant.load md to virtual function load to indicate that
|
|
// function didn't change inside vtable.
|
|
// It's safe to add it without -fstrict-vtable-pointers, but it would not
|
|
// help in devirtualization because it will only matter if we will have 2
|
|
// the same virtual function loads from the same vtable load, which won't
|
|
// happen without enabled devirtualization with -fstrict-vtable-pointers.
|
|
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
|
|
CGM.getCodeGenOpts().StrictVTablePointers) {
|
|
if (auto *VFuncLoadInstr = dyn_cast<llvm::Instruction>(VFuncLoad)) {
|
|
VFuncLoadInstr->setMetadata(
|
|
llvm::LLVMContext::MD_invariant_load,
|
|
llvm::MDNode::get(CGM.getLLVMContext(),
|
|
llvm::ArrayRef<llvm::Metadata *>()));
|
|
}
|
|
}
|
|
VFunc = VFuncLoad;
|
|
}
|
|
|
|
CGCallee Callee(GD, VFunc);
|
|
return Callee;
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::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);
|
|
|
|
GlobalDecl GD(Dtor, DtorType);
|
|
const CGFunctionInfo *FInfo =
|
|
&CGM.getTypes().arrangeCXXStructorDeclaration(GD);
|
|
llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
|
|
CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
|
|
|
|
QualType ThisTy;
|
|
if (CE) {
|
|
ThisTy = CE->getObjectType();
|
|
} else {
|
|
ThisTy = D->getDestroyedType();
|
|
}
|
|
|
|
CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy, nullptr,
|
|
QualType(), nullptr);
|
|
return nullptr;
|
|
}
|
|
|
|
void ItaniumCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
|
|
CodeGenVTables &VTables = CGM.getVTables();
|
|
llvm::GlobalVariable *VTT = VTables.GetAddrOfVTT(RD);
|
|
VTables.EmitVTTDefinition(VTT, CGM.getVTableLinkage(RD), RD);
|
|
}
|
|
|
|
bool ItaniumCXXABI::canSpeculativelyEmitVTableAsBaseClass(
|
|
const CXXRecordDecl *RD) const {
|
|
// We don't emit available_externally vtables if we are in -fapple-kext mode
|
|
// because kext mode does not permit devirtualization.
|
|
if (CGM.getLangOpts().AppleKext)
|
|
return false;
|
|
|
|
// If the vtable is hidden then it is not safe to emit an available_externally
|
|
// copy of vtable.
|
|
if (isVTableHidden(RD))
|
|
return false;
|
|
|
|
if (CGM.getCodeGenOpts().ForceEmitVTables)
|
|
return true;
|
|
|
|
// If we don't have any not emitted inline virtual function then we are safe
|
|
// to emit an available_externally copy of vtable.
|
|
// FIXME we can still emit a copy of the vtable if we
|
|
// can emit definition of the inline functions.
|
|
if (hasAnyUnusedVirtualInlineFunction(RD))
|
|
return false;
|
|
|
|
// For a class with virtual bases, we must also be able to speculatively
|
|
// emit the VTT, because CodeGen doesn't have separate notions of "can emit
|
|
// the vtable" and "can emit the VTT". For a base subobject, this means we
|
|
// need to be able to emit non-virtual base vtables.
|
|
if (RD->getNumVBases()) {
|
|
for (const auto &B : RD->bases()) {
|
|
auto *BRD = B.getType()->getAsCXXRecordDecl();
|
|
assert(BRD && "no class for base specifier");
|
|
if (B.isVirtual() || !BRD->isDynamicClass())
|
|
continue;
|
|
if (!canSpeculativelyEmitVTableAsBaseClass(BRD))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool ItaniumCXXABI::canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const {
|
|
if (!canSpeculativelyEmitVTableAsBaseClass(RD))
|
|
return false;
|
|
|
|
// For a complete-object vtable (or more specifically, for the VTT), we need
|
|
// to be able to speculatively emit the vtables of all dynamic virtual bases.
|
|
for (const auto &B : RD->vbases()) {
|
|
auto *BRD = B.getType()->getAsCXXRecordDecl();
|
|
assert(BRD && "no class for base specifier");
|
|
if (!BRD->isDynamicClass())
|
|
continue;
|
|
if (!canSpeculativelyEmitVTableAsBaseClass(BRD))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
static llvm::Value *performTypeAdjustment(CodeGenFunction &CGF,
|
|
Address InitialPtr,
|
|
int64_t NonVirtualAdjustment,
|
|
int64_t VirtualAdjustment,
|
|
bool IsReturnAdjustment) {
|
|
if (!NonVirtualAdjustment && !VirtualAdjustment)
|
|
return InitialPtr.getPointer();
|
|
|
|
Address V = CGF.Builder.CreateElementBitCast(InitialPtr, CGF.Int8Ty);
|
|
|
|
// In a base-to-derived cast, the non-virtual adjustment is applied first.
|
|
if (NonVirtualAdjustment && !IsReturnAdjustment) {
|
|
V = CGF.Builder.CreateConstInBoundsByteGEP(V,
|
|
CharUnits::fromQuantity(NonVirtualAdjustment));
|
|
}
|
|
|
|
// Perform the virtual adjustment if we have one.
|
|
llvm::Value *ResultPtr;
|
|
if (VirtualAdjustment) {
|
|
Address VTablePtrPtr = CGF.Builder.CreateElementBitCast(V, CGF.Int8PtrTy);
|
|
llvm::Value *VTablePtr = CGF.Builder.CreateLoad(VTablePtrPtr);
|
|
|
|
llvm::Value *Offset;
|
|
llvm::Value *OffsetPtr =
|
|
CGF.Builder.CreateConstInBoundsGEP1_64(VTablePtr, VirtualAdjustment);
|
|
if (CGF.CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
// Load the adjustment offset from the vtable as a 32-bit int.
|
|
OffsetPtr =
|
|
CGF.Builder.CreateBitCast(OffsetPtr, CGF.Int32Ty->getPointerTo());
|
|
Offset =
|
|
CGF.Builder.CreateAlignedLoad(OffsetPtr, CharUnits::fromQuantity(4));
|
|
} else {
|
|
llvm::Type *PtrDiffTy =
|
|
CGF.ConvertType(CGF.getContext().getPointerDiffType());
|
|
|
|
OffsetPtr =
|
|
CGF.Builder.CreateBitCast(OffsetPtr, PtrDiffTy->getPointerTo());
|
|
|
|
// Load the adjustment offset from the vtable.
|
|
Offset = CGF.Builder.CreateAlignedLoad(OffsetPtr, CGF.getPointerAlign());
|
|
}
|
|
// Adjust our pointer.
|
|
ResultPtr = CGF.Builder.CreateInBoundsGEP(V.getPointer(), Offset);
|
|
} else {
|
|
ResultPtr = V.getPointer();
|
|
}
|
|
|
|
// In a derived-to-base conversion, the non-virtual adjustment is
|
|
// applied second.
|
|
if (NonVirtualAdjustment && IsReturnAdjustment) {
|
|
ResultPtr = CGF.Builder.CreateConstInBoundsGEP1_64(ResultPtr,
|
|
NonVirtualAdjustment);
|
|
}
|
|
|
|
// Cast back to the original type.
|
|
return CGF.Builder.CreateBitCast(ResultPtr, InitialPtr.getType());
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::performThisAdjustment(CodeGenFunction &CGF,
|
|
Address This,
|
|
const ThisAdjustment &TA) {
|
|
return performTypeAdjustment(CGF, This, TA.NonVirtual,
|
|
TA.Virtual.Itanium.VCallOffsetOffset,
|
|
/*IsReturnAdjustment=*/false);
|
|
}
|
|
|
|
llvm::Value *
|
|
ItaniumCXXABI::performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
|
|
const ReturnAdjustment &RA) {
|
|
return performTypeAdjustment(CGF, Ret, RA.NonVirtual,
|
|
RA.Virtual.Itanium.VBaseOffsetOffset,
|
|
/*IsReturnAdjustment=*/true);
|
|
}
|
|
|
|
void ARMCXXABI::EmitReturnFromThunk(CodeGenFunction &CGF,
|
|
RValue RV, QualType ResultType) {
|
|
if (!isa<CXXDestructorDecl>(CGF.CurGD.getDecl()))
|
|
return ItaniumCXXABI::EmitReturnFromThunk(CGF, RV, ResultType);
|
|
|
|
// Destructor thunks in the ARM ABI have indeterminate results.
|
|
llvm::Type *T = CGF.ReturnValue.getElementType();
|
|
RValue Undef = RValue::get(llvm::UndefValue::get(T));
|
|
return ItaniumCXXABI::EmitReturnFromThunk(CGF, Undef, ResultType);
|
|
}
|
|
|
|
/************************** Array allocation cookies **************************/
|
|
|
|
CharUnits ItaniumCXXABI::getArrayCookieSizeImpl(QualType elementType) {
|
|
// The array cookie is a size_t; pad that up to the element alignment.
|
|
// The cookie is actually right-justified in that space.
|
|
return std::max(CharUnits::fromQuantity(CGM.SizeSizeInBytes),
|
|
CGM.getContext().getPreferredTypeAlignInChars(elementType));
|
|
}
|
|
|
|
Address ItaniumCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
|
|
Address NewPtr,
|
|
llvm::Value *NumElements,
|
|
const CXXNewExpr *expr,
|
|
QualType ElementType) {
|
|
assert(requiresArrayCookie(expr));
|
|
|
|
unsigned AS = NewPtr.getAddressSpace();
|
|
|
|
ASTContext &Ctx = getContext();
|
|
CharUnits SizeSize = CGF.getSizeSize();
|
|
|
|
// The size of the cookie.
|
|
CharUnits CookieSize =
|
|
std::max(SizeSize, Ctx.getPreferredTypeAlignInChars(ElementType));
|
|
assert(CookieSize == getArrayCookieSizeImpl(ElementType));
|
|
|
|
// Compute an offset to the cookie.
|
|
Address CookiePtr = NewPtr;
|
|
CharUnits CookieOffset = CookieSize - SizeSize;
|
|
if (!CookieOffset.isZero())
|
|
CookiePtr = CGF.Builder.CreateConstInBoundsByteGEP(CookiePtr, CookieOffset);
|
|
|
|
// Write the number of elements into the appropriate slot.
|
|
Address NumElementsPtr =
|
|
CGF.Builder.CreateElementBitCast(CookiePtr, CGF.SizeTy);
|
|
llvm::Instruction *SI = CGF.Builder.CreateStore(NumElements, NumElementsPtr);
|
|
|
|
// Handle the array cookie specially in ASan.
|
|
if (CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) && AS == 0 &&
|
|
(expr->getOperatorNew()->isReplaceableGlobalAllocationFunction() ||
|
|
CGM.getCodeGenOpts().SanitizeAddressPoisonCustomArrayCookie)) {
|
|
// The store to the CookiePtr does not need to be instrumented.
|
|
CGM.getSanitizerMetadata()->disableSanitizerForInstruction(SI);
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, NumElementsPtr.getType(), false);
|
|
llvm::FunctionCallee F =
|
|
CGM.CreateRuntimeFunction(FTy, "__asan_poison_cxx_array_cookie");
|
|
CGF.Builder.CreateCall(F, NumElementsPtr.getPointer());
|
|
}
|
|
|
|
// Finally, compute a pointer to the actual data buffer by skipping
|
|
// over the cookie completely.
|
|
return CGF.Builder.CreateConstInBoundsByteGEP(NewPtr, CookieSize);
|
|
}
|
|
|
|
llvm::Value *ItaniumCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
|
|
Address allocPtr,
|
|
CharUnits cookieSize) {
|
|
// The element size is right-justified in the cookie.
|
|
Address numElementsPtr = allocPtr;
|
|
CharUnits numElementsOffset = cookieSize - CGF.getSizeSize();
|
|
if (!numElementsOffset.isZero())
|
|
numElementsPtr =
|
|
CGF.Builder.CreateConstInBoundsByteGEP(numElementsPtr, numElementsOffset);
|
|
|
|
unsigned AS = allocPtr.getAddressSpace();
|
|
numElementsPtr = CGF.Builder.CreateElementBitCast(numElementsPtr, CGF.SizeTy);
|
|
if (!CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) || AS != 0)
|
|
return CGF.Builder.CreateLoad(numElementsPtr);
|
|
// In asan mode emit a function call instead of a regular load and let the
|
|
// run-time deal with it: if the shadow is properly poisoned return the
|
|
// cookie, otherwise return 0 to avoid an infinite loop calling DTORs.
|
|
// We can't simply ignore this load using nosanitize metadata because
|
|
// the metadata may be lost.
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGF.SizeTy, CGF.SizeTy->getPointerTo(0), false);
|
|
llvm::FunctionCallee F =
|
|
CGM.CreateRuntimeFunction(FTy, "__asan_load_cxx_array_cookie");
|
|
return CGF.Builder.CreateCall(F, numElementsPtr.getPointer());
|
|
}
|
|
|
|
CharUnits ARMCXXABI::getArrayCookieSizeImpl(QualType elementType) {
|
|
// ARM says that the cookie is always:
|
|
// struct array_cookie {
|
|
// std::size_t element_size; // element_size != 0
|
|
// std::size_t element_count;
|
|
// };
|
|
// But the base ABI doesn't give anything an alignment greater than
|
|
// 8, so we can dismiss this as typical ABI-author blindness to
|
|
// actual language complexity and round up to the element alignment.
|
|
return std::max(CharUnits::fromQuantity(2 * CGM.SizeSizeInBytes),
|
|
CGM.getContext().getTypeAlignInChars(elementType));
|
|
}
|
|
|
|
Address ARMCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
|
|
Address newPtr,
|
|
llvm::Value *numElements,
|
|
const CXXNewExpr *expr,
|
|
QualType elementType) {
|
|
assert(requiresArrayCookie(expr));
|
|
|
|
// The cookie is always at the start of the buffer.
|
|
Address cookie = newPtr;
|
|
|
|
// The first element is the element size.
|
|
cookie = CGF.Builder.CreateElementBitCast(cookie, CGF.SizeTy);
|
|
llvm::Value *elementSize = llvm::ConstantInt::get(CGF.SizeTy,
|
|
getContext().getTypeSizeInChars(elementType).getQuantity());
|
|
CGF.Builder.CreateStore(elementSize, cookie);
|
|
|
|
// The second element is the element count.
|
|
cookie = CGF.Builder.CreateConstInBoundsGEP(cookie, 1);
|
|
CGF.Builder.CreateStore(numElements, cookie);
|
|
|
|
// Finally, compute a pointer to the actual data buffer by skipping
|
|
// over the cookie completely.
|
|
CharUnits cookieSize = ARMCXXABI::getArrayCookieSizeImpl(elementType);
|
|
return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
|
|
}
|
|
|
|
llvm::Value *ARMCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
|
|
Address allocPtr,
|
|
CharUnits cookieSize) {
|
|
// The number of elements is at offset sizeof(size_t) relative to
|
|
// the allocated pointer.
|
|
Address numElementsPtr
|
|
= CGF.Builder.CreateConstInBoundsByteGEP(allocPtr, CGF.getSizeSize());
|
|
|
|
numElementsPtr = CGF.Builder.CreateElementBitCast(numElementsPtr, CGF.SizeTy);
|
|
return CGF.Builder.CreateLoad(numElementsPtr);
|
|
}
|
|
|
|
/*********************** Static local initialization **************************/
|
|
|
|
static llvm::FunctionCallee getGuardAcquireFn(CodeGenModule &CGM,
|
|
llvm::PointerType *GuardPtrTy) {
|
|
// int __cxa_guard_acquire(__guard *guard_object);
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.getTypes().ConvertType(CGM.getContext().IntTy),
|
|
GuardPtrTy, /*isVarArg=*/false);
|
|
return CGM.CreateRuntimeFunction(
|
|
FTy, "__cxa_guard_acquire",
|
|
llvm::AttributeList::get(CGM.getLLVMContext(),
|
|
llvm::AttributeList::FunctionIndex,
|
|
llvm::Attribute::NoUnwind));
|
|
}
|
|
|
|
static llvm::FunctionCallee getGuardReleaseFn(CodeGenModule &CGM,
|
|
llvm::PointerType *GuardPtrTy) {
|
|
// void __cxa_guard_release(__guard *guard_object);
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, GuardPtrTy, /*isVarArg=*/false);
|
|
return CGM.CreateRuntimeFunction(
|
|
FTy, "__cxa_guard_release",
|
|
llvm::AttributeList::get(CGM.getLLVMContext(),
|
|
llvm::AttributeList::FunctionIndex,
|
|
llvm::Attribute::NoUnwind));
|
|
}
|
|
|
|
static llvm::FunctionCallee getGuardAbortFn(CodeGenModule &CGM,
|
|
llvm::PointerType *GuardPtrTy) {
|
|
// void __cxa_guard_abort(__guard *guard_object);
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, GuardPtrTy, /*isVarArg=*/false);
|
|
return CGM.CreateRuntimeFunction(
|
|
FTy, "__cxa_guard_abort",
|
|
llvm::AttributeList::get(CGM.getLLVMContext(),
|
|
llvm::AttributeList::FunctionIndex,
|
|
llvm::Attribute::NoUnwind));
|
|
}
|
|
|
|
namespace {
|
|
struct CallGuardAbort final : EHScopeStack::Cleanup {
|
|
llvm::GlobalVariable *Guard;
|
|
CallGuardAbort(llvm::GlobalVariable *Guard) : Guard(Guard) {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
CGF.EmitNounwindRuntimeCall(getGuardAbortFn(CGF.CGM, Guard->getType()),
|
|
Guard);
|
|
}
|
|
};
|
|
}
|
|
|
|
/// The ARM code here follows the Itanium code closely enough that we
|
|
/// just special-case it at particular places.
|
|
void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
|
|
const VarDecl &D,
|
|
llvm::GlobalVariable *var,
|
|
bool shouldPerformInit) {
|
|
CGBuilderTy &Builder = CGF.Builder;
|
|
|
|
// Inline variables that weren't instantiated from variable templates have
|
|
// partially-ordered initialization within their translation unit.
|
|
bool NonTemplateInline =
|
|
D.isInline() &&
|
|
!isTemplateInstantiation(D.getTemplateSpecializationKind());
|
|
|
|
// We only need to use thread-safe statics for local non-TLS variables and
|
|
// inline variables; other global initialization is always single-threaded
|
|
// or (through lazy dynamic loading in multiple threads) unsequenced.
|
|
bool threadsafe = getContext().getLangOpts().ThreadsafeStatics &&
|
|
(D.isLocalVarDecl() || NonTemplateInline) &&
|
|
!D.getTLSKind();
|
|
|
|
// If we have a global variable with internal linkage and thread-safe statics
|
|
// are disabled, we can just let the guard variable be of type i8.
|
|
bool useInt8GuardVariable = !threadsafe && var->hasInternalLinkage();
|
|
|
|
llvm::IntegerType *guardTy;
|
|
CharUnits guardAlignment;
|
|
if (useInt8GuardVariable) {
|
|
guardTy = CGF.Int8Ty;
|
|
guardAlignment = CharUnits::One();
|
|
} else {
|
|
// Guard variables are 64 bits in the generic ABI and size width on ARM
|
|
// (i.e. 32-bit on AArch32, 64-bit on AArch64).
|
|
if (UseARMGuardVarABI) {
|
|
guardTy = CGF.SizeTy;
|
|
guardAlignment = CGF.getSizeAlign();
|
|
} else {
|
|
guardTy = CGF.Int64Ty;
|
|
guardAlignment = CharUnits::fromQuantity(
|
|
CGM.getDataLayout().getABITypeAlignment(guardTy));
|
|
}
|
|
}
|
|
llvm::PointerType *guardPtrTy = guardTy->getPointerTo(
|
|
CGF.CGM.getDataLayout().getDefaultGlobalsAddressSpace());
|
|
|
|
// Create the guard variable if we don't already have it (as we
|
|
// might if we're double-emitting this function body).
|
|
llvm::GlobalVariable *guard = CGM.getStaticLocalDeclGuardAddress(&D);
|
|
if (!guard) {
|
|
// Mangle the name for the guard.
|
|
SmallString<256> guardName;
|
|
{
|
|
llvm::raw_svector_ostream out(guardName);
|
|
getMangleContext().mangleStaticGuardVariable(&D, out);
|
|
}
|
|
|
|
// Create the guard variable with a zero-initializer.
|
|
// Just absorb linkage and visibility from the guarded variable.
|
|
guard = new llvm::GlobalVariable(CGM.getModule(), guardTy,
|
|
false, var->getLinkage(),
|
|
llvm::ConstantInt::get(guardTy, 0),
|
|
guardName.str());
|
|
guard->setDSOLocal(var->isDSOLocal());
|
|
guard->setVisibility(var->getVisibility());
|
|
// If the variable is thread-local, so is its guard variable.
|
|
guard->setThreadLocalMode(var->getThreadLocalMode());
|
|
guard->setAlignment(guardAlignment.getAsAlign());
|
|
|
|
// The ABI says: "It is suggested that it be emitted in the same COMDAT
|
|
// group as the associated data object." In practice, this doesn't work for
|
|
// non-ELF and non-Wasm object formats, so only do it for ELF and Wasm.
|
|
llvm::Comdat *C = var->getComdat();
|
|
if (!D.isLocalVarDecl() && C &&
|
|
(CGM.getTarget().getTriple().isOSBinFormatELF() ||
|
|
CGM.getTarget().getTriple().isOSBinFormatWasm())) {
|
|
guard->setComdat(C);
|
|
// An inline variable's guard function is run from the per-TU
|
|
// initialization function, not via a dedicated global ctor function, so
|
|
// we can't put it in a comdat.
|
|
if (!NonTemplateInline)
|
|
CGF.CurFn->setComdat(C);
|
|
} else if (CGM.supportsCOMDAT() && guard->isWeakForLinker()) {
|
|
guard->setComdat(CGM.getModule().getOrInsertComdat(guard->getName()));
|
|
}
|
|
|
|
CGM.setStaticLocalDeclGuardAddress(&D, guard);
|
|
}
|
|
|
|
Address guardAddr = Address(guard, guardAlignment);
|
|
|
|
// Test whether the variable has completed initialization.
|
|
//
|
|
// Itanium C++ ABI 3.3.2:
|
|
// The following is pseudo-code showing how these functions can be used:
|
|
// if (obj_guard.first_byte == 0) {
|
|
// if ( __cxa_guard_acquire (&obj_guard) ) {
|
|
// try {
|
|
// ... initialize the object ...;
|
|
// } catch (...) {
|
|
// __cxa_guard_abort (&obj_guard);
|
|
// throw;
|
|
// }
|
|
// ... queue object destructor with __cxa_atexit() ...;
|
|
// __cxa_guard_release (&obj_guard);
|
|
// }
|
|
// }
|
|
|
|
// Load the first byte of the guard variable.
|
|
llvm::LoadInst *LI =
|
|
Builder.CreateLoad(Builder.CreateElementBitCast(guardAddr, CGM.Int8Ty));
|
|
|
|
// Itanium ABI:
|
|
// An implementation supporting thread-safety on multiprocessor
|
|
// systems must also guarantee that references to the initialized
|
|
// object do not occur before the load of the initialization flag.
|
|
//
|
|
// In LLVM, we do this by marking the load Acquire.
|
|
if (threadsafe)
|
|
LI->setAtomic(llvm::AtomicOrdering::Acquire);
|
|
|
|
// For ARM, we should only check the first bit, rather than the entire byte:
|
|
//
|
|
// ARM C++ ABI 3.2.3.1:
|
|
// To support the potential use of initialization guard variables
|
|
// as semaphores that are the target of ARM SWP and LDREX/STREX
|
|
// synchronizing instructions we define a static initialization
|
|
// guard variable to be a 4-byte aligned, 4-byte word with the
|
|
// following inline access protocol.
|
|
// #define INITIALIZED 1
|
|
// if ((obj_guard & INITIALIZED) != INITIALIZED) {
|
|
// if (__cxa_guard_acquire(&obj_guard))
|
|
// ...
|
|
// }
|
|
//
|
|
// and similarly for ARM64:
|
|
//
|
|
// ARM64 C++ ABI 3.2.2:
|
|
// This ABI instead only specifies the value bit 0 of the static guard
|
|
// variable; all other bits are platform defined. Bit 0 shall be 0 when the
|
|
// variable is not initialized and 1 when it is.
|
|
llvm::Value *V =
|
|
(UseARMGuardVarABI && !useInt8GuardVariable)
|
|
? Builder.CreateAnd(LI, llvm::ConstantInt::get(CGM.Int8Ty, 1))
|
|
: LI;
|
|
llvm::Value *NeedsInit = Builder.CreateIsNull(V, "guard.uninitialized");
|
|
|
|
llvm::BasicBlock *InitCheckBlock = CGF.createBasicBlock("init.check");
|
|
llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
|
|
|
|
// Check if the first byte of the guard variable is zero.
|
|
CGF.EmitCXXGuardedInitBranch(NeedsInit, InitCheckBlock, EndBlock,
|
|
CodeGenFunction::GuardKind::VariableGuard, &D);
|
|
|
|
CGF.EmitBlock(InitCheckBlock);
|
|
|
|
// Variables used when coping with thread-safe statics and exceptions.
|
|
if (threadsafe) {
|
|
// Call __cxa_guard_acquire.
|
|
llvm::Value *V
|
|
= CGF.EmitNounwindRuntimeCall(getGuardAcquireFn(CGM, guardPtrTy), guard);
|
|
|
|
llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
|
|
|
|
Builder.CreateCondBr(Builder.CreateIsNotNull(V, "tobool"),
|
|
InitBlock, EndBlock);
|
|
|
|
// Call __cxa_guard_abort along the exceptional edge.
|
|
CGF.EHStack.pushCleanup<CallGuardAbort>(EHCleanup, guard);
|
|
|
|
CGF.EmitBlock(InitBlock);
|
|
}
|
|
|
|
// Emit the initializer and add a global destructor if appropriate.
|
|
CGF.EmitCXXGlobalVarDeclInit(D, var, shouldPerformInit);
|
|
|
|
if (threadsafe) {
|
|
// Pop the guard-abort cleanup if we pushed one.
|
|
CGF.PopCleanupBlock();
|
|
|
|
// Call __cxa_guard_release. This cannot throw.
|
|
CGF.EmitNounwindRuntimeCall(getGuardReleaseFn(CGM, guardPtrTy),
|
|
guardAddr.getPointer());
|
|
} else {
|
|
Builder.CreateStore(llvm::ConstantInt::get(guardTy, 1), guardAddr);
|
|
}
|
|
|
|
CGF.EmitBlock(EndBlock);
|
|
}
|
|
|
|
/// Register a global destructor using __cxa_atexit.
|
|
static void emitGlobalDtorWithCXAAtExit(CodeGenFunction &CGF,
|
|
llvm::FunctionCallee dtor,
|
|
llvm::Constant *addr, bool TLS) {
|
|
assert((TLS || CGF.getTypes().getCodeGenOpts().CXAAtExit) &&
|
|
"__cxa_atexit is disabled");
|
|
const char *Name = "__cxa_atexit";
|
|
if (TLS) {
|
|
const llvm::Triple &T = CGF.getTarget().getTriple();
|
|
Name = T.isOSDarwin() ? "_tlv_atexit" : "__cxa_thread_atexit";
|
|
}
|
|
|
|
// We're assuming that the destructor function is something we can
|
|
// reasonably call with the default CC. Go ahead and cast it to the
|
|
// right prototype.
|
|
llvm::Type *dtorTy =
|
|
llvm::FunctionType::get(CGF.VoidTy, CGF.Int8PtrTy, false)->getPointerTo();
|
|
|
|
// Preserve address space of addr.
|
|
auto AddrAS = addr ? addr->getType()->getPointerAddressSpace() : 0;
|
|
auto AddrInt8PtrTy =
|
|
AddrAS ? CGF.Int8Ty->getPointerTo(AddrAS) : CGF.Int8PtrTy;
|
|
|
|
// Create a variable that binds the atexit to this shared object.
|
|
llvm::Constant *handle =
|
|
CGF.CGM.CreateRuntimeVariable(CGF.Int8Ty, "__dso_handle");
|
|
auto *GV = cast<llvm::GlobalValue>(handle->stripPointerCasts());
|
|
GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
|
|
|
|
// extern "C" int __cxa_atexit(void (*f)(void *), void *p, void *d);
|
|
llvm::Type *paramTys[] = {dtorTy, AddrInt8PtrTy, handle->getType()};
|
|
llvm::FunctionType *atexitTy =
|
|
llvm::FunctionType::get(CGF.IntTy, paramTys, false);
|
|
|
|
// Fetch the actual function.
|
|
llvm::FunctionCallee atexit = CGF.CGM.CreateRuntimeFunction(atexitTy, Name);
|
|
if (llvm::Function *fn = dyn_cast<llvm::Function>(atexit.getCallee()))
|
|
fn->setDoesNotThrow();
|
|
|
|
if (!addr)
|
|
// addr is null when we are trying to register a dtor annotated with
|
|
// __attribute__((destructor)) in a constructor function. Using null here is
|
|
// okay because this argument is just passed back to the destructor
|
|
// function.
|
|
addr = llvm::Constant::getNullValue(CGF.Int8PtrTy);
|
|
|
|
llvm::Value *args[] = {llvm::ConstantExpr::getBitCast(
|
|
cast<llvm::Constant>(dtor.getCallee()), dtorTy),
|
|
llvm::ConstantExpr::getBitCast(addr, AddrInt8PtrTy),
|
|
handle};
|
|
CGF.EmitNounwindRuntimeCall(atexit, args);
|
|
}
|
|
|
|
static llvm::Function *createGlobalInitOrCleanupFn(CodeGen::CodeGenModule &CGM,
|
|
StringRef FnName) {
|
|
// Create a function that registers/unregisters destructors that have the same
|
|
// priority.
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(CGM.VoidTy, false);
|
|
llvm::Function *GlobalInitOrCleanupFn = CGM.CreateGlobalInitOrCleanUpFunction(
|
|
FTy, FnName, CGM.getTypes().arrangeNullaryFunction(), SourceLocation());
|
|
|
|
return GlobalInitOrCleanupFn;
|
|
}
|
|
|
|
static FunctionDecl *
|
|
createGlobalInitOrCleanupFnDecl(CodeGen::CodeGenModule &CGM, StringRef FnName) {
|
|
ASTContext &Ctx = CGM.getContext();
|
|
QualType FunctionTy = Ctx.getFunctionType(Ctx.VoidTy, llvm::None, {});
|
|
return FunctionDecl::Create(
|
|
Ctx, Ctx.getTranslationUnitDecl(), SourceLocation(), SourceLocation(),
|
|
&Ctx.Idents.get(FnName), FunctionTy, nullptr, SC_Static, false, false);
|
|
}
|
|
|
|
void CodeGenModule::unregisterGlobalDtorsWithUnAtExit() {
|
|
for (const auto &I : DtorsUsingAtExit) {
|
|
int Priority = I.first;
|
|
std::string GlobalCleanupFnName =
|
|
std::string("__GLOBAL_cleanup_") + llvm::to_string(Priority);
|
|
|
|
llvm::Function *GlobalCleanupFn =
|
|
createGlobalInitOrCleanupFn(*this, GlobalCleanupFnName);
|
|
|
|
FunctionDecl *GlobalCleanupFD =
|
|
createGlobalInitOrCleanupFnDecl(*this, GlobalCleanupFnName);
|
|
|
|
CodeGenFunction CGF(*this);
|
|
CGF.StartFunction(GlobalDecl(GlobalCleanupFD), getContext().VoidTy,
|
|
GlobalCleanupFn, getTypes().arrangeNullaryFunction(),
|
|
FunctionArgList(), SourceLocation(), SourceLocation());
|
|
|
|
// Get the destructor function type, void(*)(void).
|
|
llvm::FunctionType *dtorFuncTy = llvm::FunctionType::get(CGF.VoidTy, false);
|
|
llvm::Type *dtorTy = dtorFuncTy->getPointerTo();
|
|
|
|
// Destructor functions are run/unregistered in non-ascending
|
|
// order of their priorities.
|
|
const llvm::TinyPtrVector<llvm::Function *> &Dtors = I.second;
|
|
auto itv = Dtors.rbegin();
|
|
while (itv != Dtors.rend()) {
|
|
llvm::Function *Dtor = *itv;
|
|
|
|
// We're assuming that the destructor function is something we can
|
|
// reasonably call with the correct CC. Go ahead and cast it to the
|
|
// right prototype.
|
|
llvm::Constant *dtor = llvm::ConstantExpr::getBitCast(Dtor, dtorTy);
|
|
llvm::Value *V = CGF.unregisterGlobalDtorWithUnAtExit(dtor);
|
|
llvm::Value *NeedsDestruct =
|
|
CGF.Builder.CreateIsNull(V, "needs_destruct");
|
|
|
|
llvm::BasicBlock *DestructCallBlock =
|
|
CGF.createBasicBlock("destruct.call");
|
|
llvm::BasicBlock *EndBlock = CGF.createBasicBlock(
|
|
(itv + 1) != Dtors.rend() ? "unatexit.call" : "destruct.end");
|
|
// Check if unatexit returns a value of 0. If it does, jump to
|
|
// DestructCallBlock, otherwise jump to EndBlock directly.
|
|
CGF.Builder.CreateCondBr(NeedsDestruct, DestructCallBlock, EndBlock);
|
|
|
|
CGF.EmitBlock(DestructCallBlock);
|
|
|
|
// Emit the call to casted Dtor.
|
|
llvm::CallInst *CI = CGF.Builder.CreateCall(dtorFuncTy, dtor);
|
|
// Make sure the call and the callee agree on calling convention.
|
|
CI->setCallingConv(Dtor->getCallingConv());
|
|
|
|
CGF.EmitBlock(EndBlock);
|
|
|
|
itv++;
|
|
}
|
|
|
|
CGF.FinishFunction();
|
|
AddGlobalDtor(GlobalCleanupFn, Priority);
|
|
}
|
|
}
|
|
|
|
void CodeGenModule::registerGlobalDtorsWithAtExit() {
|
|
for (const auto &I : DtorsUsingAtExit) {
|
|
int Priority = I.first;
|
|
std::string GlobalInitFnName =
|
|
std::string("__GLOBAL_init_") + llvm::to_string(Priority);
|
|
llvm::Function *GlobalInitFn =
|
|
createGlobalInitOrCleanupFn(*this, GlobalInitFnName);
|
|
FunctionDecl *GlobalInitFD =
|
|
createGlobalInitOrCleanupFnDecl(*this, GlobalInitFnName);
|
|
|
|
CodeGenFunction CGF(*this);
|
|
CGF.StartFunction(GlobalDecl(GlobalInitFD), getContext().VoidTy,
|
|
GlobalInitFn, getTypes().arrangeNullaryFunction(),
|
|
FunctionArgList(), SourceLocation(), SourceLocation());
|
|
|
|
// Since constructor functions are run in non-descending order of their
|
|
// priorities, destructors are registered in non-descending order of their
|
|
// priorities, and since destructor functions are run in the reverse order
|
|
// of their registration, destructor functions are run in non-ascending
|
|
// order of their priorities.
|
|
const llvm::TinyPtrVector<llvm::Function *> &Dtors = I.second;
|
|
for (auto *Dtor : Dtors) {
|
|
// Register the destructor function calling __cxa_atexit if it is
|
|
// available. Otherwise fall back on calling atexit.
|
|
if (getCodeGenOpts().CXAAtExit) {
|
|
emitGlobalDtorWithCXAAtExit(CGF, Dtor, nullptr, false);
|
|
} else {
|
|
// Get the destructor function type, void(*)(void).
|
|
llvm::Type *dtorTy =
|
|
llvm::FunctionType::get(CGF.VoidTy, false)->getPointerTo();
|
|
|
|
// We're assuming that the destructor function is something we can
|
|
// reasonably call with the correct CC. Go ahead and cast it to the
|
|
// right prototype.
|
|
CGF.registerGlobalDtorWithAtExit(
|
|
llvm::ConstantExpr::getBitCast(Dtor, dtorTy));
|
|
}
|
|
}
|
|
|
|
CGF.FinishFunction();
|
|
AddGlobalCtor(GlobalInitFn, Priority, nullptr);
|
|
}
|
|
|
|
if (getCXXABI().useSinitAndSterm())
|
|
unregisterGlobalDtorsWithUnAtExit();
|
|
}
|
|
|
|
/// Register a global destructor as best as we know how.
|
|
void ItaniumCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
|
|
llvm::FunctionCallee dtor,
|
|
llvm::Constant *addr) {
|
|
if (D.isNoDestroy(CGM.getContext()))
|
|
return;
|
|
|
|
// emitGlobalDtorWithCXAAtExit will emit a call to either __cxa_thread_atexit
|
|
// or __cxa_atexit depending on whether this VarDecl is a thread-local storage
|
|
// or not. CXAAtExit controls only __cxa_atexit, so use it if it is enabled.
|
|
// We can always use __cxa_thread_atexit.
|
|
if (CGM.getCodeGenOpts().CXAAtExit || D.getTLSKind())
|
|
return emitGlobalDtorWithCXAAtExit(CGF, dtor, addr, D.getTLSKind());
|
|
|
|
// In Apple kexts, we want to add a global destructor entry.
|
|
// FIXME: shouldn't this be guarded by some variable?
|
|
if (CGM.getLangOpts().AppleKext) {
|
|
// Generate a global destructor entry.
|
|
return CGM.AddCXXDtorEntry(dtor, addr);
|
|
}
|
|
|
|
CGF.registerGlobalDtorWithAtExit(D, dtor, addr);
|
|
}
|
|
|
|
static bool isThreadWrapperReplaceable(const VarDecl *VD,
|
|
CodeGen::CodeGenModule &CGM) {
|
|
assert(!VD->isStaticLocal() && "static local VarDecls don't need wrappers!");
|
|
// Darwin prefers to have references to thread local variables to go through
|
|
// the thread wrapper instead of directly referencing the backing variable.
|
|
return VD->getTLSKind() == VarDecl::TLS_Dynamic &&
|
|
CGM.getTarget().getTriple().isOSDarwin();
|
|
}
|
|
|
|
/// Get the appropriate linkage for the wrapper function. This is essentially
|
|
/// the weak form of the variable's linkage; every translation unit which needs
|
|
/// the wrapper emits a copy, and we want the linker to merge them.
|
|
static llvm::GlobalValue::LinkageTypes
|
|
getThreadLocalWrapperLinkage(const VarDecl *VD, CodeGen::CodeGenModule &CGM) {
|
|
llvm::GlobalValue::LinkageTypes VarLinkage =
|
|
CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false);
|
|
|
|
// For internal linkage variables, we don't need an external or weak wrapper.
|
|
if (llvm::GlobalValue::isLocalLinkage(VarLinkage))
|
|
return VarLinkage;
|
|
|
|
// If the thread wrapper is replaceable, give it appropriate linkage.
|
|
if (isThreadWrapperReplaceable(VD, CGM))
|
|
if (!llvm::GlobalVariable::isLinkOnceLinkage(VarLinkage) &&
|
|
!llvm::GlobalVariable::isWeakODRLinkage(VarLinkage))
|
|
return VarLinkage;
|
|
return llvm::GlobalValue::WeakODRLinkage;
|
|
}
|
|
|
|
llvm::Function *
|
|
ItaniumCXXABI::getOrCreateThreadLocalWrapper(const VarDecl *VD,
|
|
llvm::Value *Val) {
|
|
// Mangle the name for the thread_local wrapper function.
|
|
SmallString<256> WrapperName;
|
|
{
|
|
llvm::raw_svector_ostream Out(WrapperName);
|
|
getMangleContext().mangleItaniumThreadLocalWrapper(VD, Out);
|
|
}
|
|
|
|
// FIXME: If VD is a definition, we should regenerate the function attributes
|
|
// before returning.
|
|
if (llvm::Value *V = CGM.getModule().getNamedValue(WrapperName))
|
|
return cast<llvm::Function>(V);
|
|
|
|
QualType RetQT = VD->getType();
|
|
if (RetQT->isReferenceType())
|
|
RetQT = RetQT.getNonReferenceType();
|
|
|
|
const CGFunctionInfo &FI = CGM.getTypes().arrangeBuiltinFunctionDeclaration(
|
|
getContext().getPointerType(RetQT), FunctionArgList());
|
|
|
|
llvm::FunctionType *FnTy = CGM.getTypes().GetFunctionType(FI);
|
|
llvm::Function *Wrapper =
|
|
llvm::Function::Create(FnTy, getThreadLocalWrapperLinkage(VD, CGM),
|
|
WrapperName.str(), &CGM.getModule());
|
|
|
|
if (CGM.supportsCOMDAT() && Wrapper->isWeakForLinker())
|
|
Wrapper->setComdat(CGM.getModule().getOrInsertComdat(Wrapper->getName()));
|
|
|
|
CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Wrapper);
|
|
|
|
// Always resolve references to the wrapper at link time.
|
|
if (!Wrapper->hasLocalLinkage())
|
|
if (!isThreadWrapperReplaceable(VD, CGM) ||
|
|
llvm::GlobalVariable::isLinkOnceLinkage(Wrapper->getLinkage()) ||
|
|
llvm::GlobalVariable::isWeakODRLinkage(Wrapper->getLinkage()) ||
|
|
VD->getVisibility() == HiddenVisibility)
|
|
Wrapper->setVisibility(llvm::GlobalValue::HiddenVisibility);
|
|
|
|
if (isThreadWrapperReplaceable(VD, CGM)) {
|
|
Wrapper->setCallingConv(llvm::CallingConv::CXX_FAST_TLS);
|
|
Wrapper->addFnAttr(llvm::Attribute::NoUnwind);
|
|
}
|
|
|
|
ThreadWrappers.push_back({VD, Wrapper});
|
|
return Wrapper;
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitThreadLocalInitFuncs(
|
|
CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
|
|
ArrayRef<llvm::Function *> CXXThreadLocalInits,
|
|
ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
|
|
llvm::Function *InitFunc = nullptr;
|
|
|
|
// Separate initializers into those with ordered (or partially-ordered)
|
|
// initialization and those with unordered initialization.
|
|
llvm::SmallVector<llvm::Function *, 8> OrderedInits;
|
|
llvm::SmallDenseMap<const VarDecl *, llvm::Function *> UnorderedInits;
|
|
for (unsigned I = 0; I != CXXThreadLocalInits.size(); ++I) {
|
|
if (isTemplateInstantiation(
|
|
CXXThreadLocalInitVars[I]->getTemplateSpecializationKind()))
|
|
UnorderedInits[CXXThreadLocalInitVars[I]->getCanonicalDecl()] =
|
|
CXXThreadLocalInits[I];
|
|
else
|
|
OrderedInits.push_back(CXXThreadLocalInits[I]);
|
|
}
|
|
|
|
if (!OrderedInits.empty()) {
|
|
// Generate a guarded initialization function.
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
|
|
const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
|
|
InitFunc = CGM.CreateGlobalInitOrCleanUpFunction(FTy, "__tls_init", FI,
|
|
SourceLocation(),
|
|
/*TLS=*/true);
|
|
llvm::GlobalVariable *Guard = new llvm::GlobalVariable(
|
|
CGM.getModule(), CGM.Int8Ty, /*isConstant=*/false,
|
|
llvm::GlobalVariable::InternalLinkage,
|
|
llvm::ConstantInt::get(CGM.Int8Ty, 0), "__tls_guard");
|
|
Guard->setThreadLocal(true);
|
|
Guard->setThreadLocalMode(CGM.GetDefaultLLVMTLSModel());
|
|
|
|
CharUnits GuardAlign = CharUnits::One();
|
|
Guard->setAlignment(GuardAlign.getAsAlign());
|
|
|
|
CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(
|
|
InitFunc, OrderedInits, ConstantAddress(Guard, GuardAlign));
|
|
// On Darwin platforms, use CXX_FAST_TLS calling convention.
|
|
if (CGM.getTarget().getTriple().isOSDarwin()) {
|
|
InitFunc->setCallingConv(llvm::CallingConv::CXX_FAST_TLS);
|
|
InitFunc->addFnAttr(llvm::Attribute::NoUnwind);
|
|
}
|
|
}
|
|
|
|
// Create declarations for thread wrappers for all thread-local variables
|
|
// with non-discardable definitions in this translation unit.
|
|
for (const VarDecl *VD : CXXThreadLocals) {
|
|
if (VD->hasDefinition() &&
|
|
!isDiscardableGVALinkage(getContext().GetGVALinkageForVariable(VD))) {
|
|
llvm::GlobalValue *GV = CGM.GetGlobalValue(CGM.getMangledName(VD));
|
|
getOrCreateThreadLocalWrapper(VD, GV);
|
|
}
|
|
}
|
|
|
|
// Emit all referenced thread wrappers.
|
|
for (auto VDAndWrapper : ThreadWrappers) {
|
|
const VarDecl *VD = VDAndWrapper.first;
|
|
llvm::GlobalVariable *Var =
|
|
cast<llvm::GlobalVariable>(CGM.GetGlobalValue(CGM.getMangledName(VD)));
|
|
llvm::Function *Wrapper = VDAndWrapper.second;
|
|
|
|
// Some targets require that all access to thread local variables go through
|
|
// the thread wrapper. This means that we cannot attempt to create a thread
|
|
// wrapper or a thread helper.
|
|
if (!VD->hasDefinition()) {
|
|
if (isThreadWrapperReplaceable(VD, CGM)) {
|
|
Wrapper->setLinkage(llvm::Function::ExternalLinkage);
|
|
continue;
|
|
}
|
|
|
|
// If this isn't a TU in which this variable is defined, the thread
|
|
// wrapper is discardable.
|
|
if (Wrapper->getLinkage() == llvm::Function::WeakODRLinkage)
|
|
Wrapper->setLinkage(llvm::Function::LinkOnceODRLinkage);
|
|
}
|
|
|
|
CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Wrapper);
|
|
|
|
// Mangle the name for the thread_local initialization function.
|
|
SmallString<256> InitFnName;
|
|
{
|
|
llvm::raw_svector_ostream Out(InitFnName);
|
|
getMangleContext().mangleItaniumThreadLocalInit(VD, Out);
|
|
}
|
|
|
|
llvm::FunctionType *InitFnTy = llvm::FunctionType::get(CGM.VoidTy, false);
|
|
|
|
// If we have a definition for the variable, emit the initialization
|
|
// function as an alias to the global Init function (if any). Otherwise,
|
|
// produce a declaration of the initialization function.
|
|
llvm::GlobalValue *Init = nullptr;
|
|
bool InitIsInitFunc = false;
|
|
bool HasConstantInitialization = false;
|
|
if (!usesThreadWrapperFunction(VD)) {
|
|
HasConstantInitialization = true;
|
|
} else if (VD->hasDefinition()) {
|
|
InitIsInitFunc = true;
|
|
llvm::Function *InitFuncToUse = InitFunc;
|
|
if (isTemplateInstantiation(VD->getTemplateSpecializationKind()))
|
|
InitFuncToUse = UnorderedInits.lookup(VD->getCanonicalDecl());
|
|
if (InitFuncToUse)
|
|
Init = llvm::GlobalAlias::create(Var->getLinkage(), InitFnName.str(),
|
|
InitFuncToUse);
|
|
} else {
|
|
// Emit a weak global function referring to the initialization function.
|
|
// This function will not exist if the TU defining the thread_local
|
|
// variable in question does not need any dynamic initialization for
|
|
// its thread_local variables.
|
|
Init = llvm::Function::Create(InitFnTy,
|
|
llvm::GlobalVariable::ExternalWeakLinkage,
|
|
InitFnName.str(), &CGM.getModule());
|
|
const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
|
|
CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI,
|
|
cast<llvm::Function>(Init));
|
|
}
|
|
|
|
if (Init) {
|
|
Init->setVisibility(Var->getVisibility());
|
|
// Don't mark an extern_weak function DSO local on windows.
|
|
if (!CGM.getTriple().isOSWindows() || !Init->hasExternalWeakLinkage())
|
|
Init->setDSOLocal(Var->isDSOLocal());
|
|
}
|
|
|
|
llvm::LLVMContext &Context = CGM.getModule().getContext();
|
|
llvm::BasicBlock *Entry = llvm::BasicBlock::Create(Context, "", Wrapper);
|
|
CGBuilderTy Builder(CGM, Entry);
|
|
if (HasConstantInitialization) {
|
|
// No dynamic initialization to invoke.
|
|
} else if (InitIsInitFunc) {
|
|
if (Init) {
|
|
llvm::CallInst *CallVal = Builder.CreateCall(InitFnTy, Init);
|
|
if (isThreadWrapperReplaceable(VD, CGM)) {
|
|
CallVal->setCallingConv(llvm::CallingConv::CXX_FAST_TLS);
|
|
llvm::Function *Fn =
|
|
cast<llvm::Function>(cast<llvm::GlobalAlias>(Init)->getAliasee());
|
|
Fn->setCallingConv(llvm::CallingConv::CXX_FAST_TLS);
|
|
}
|
|
}
|
|
} else {
|
|
// Don't know whether we have an init function. Call it if it exists.
|
|
llvm::Value *Have = Builder.CreateIsNotNull(Init);
|
|
llvm::BasicBlock *InitBB = llvm::BasicBlock::Create(Context, "", Wrapper);
|
|
llvm::BasicBlock *ExitBB = llvm::BasicBlock::Create(Context, "", Wrapper);
|
|
Builder.CreateCondBr(Have, InitBB, ExitBB);
|
|
|
|
Builder.SetInsertPoint(InitBB);
|
|
Builder.CreateCall(InitFnTy, Init);
|
|
Builder.CreateBr(ExitBB);
|
|
|
|
Builder.SetInsertPoint(ExitBB);
|
|
}
|
|
|
|
// For a reference, the result of the wrapper function is a pointer to
|
|
// the referenced object.
|
|
llvm::Value *Val = Var;
|
|
if (VD->getType()->isReferenceType()) {
|
|
CharUnits Align = CGM.getContext().getDeclAlign(VD);
|
|
Val = Builder.CreateAlignedLoad(Val, Align);
|
|
}
|
|
if (Val->getType() != Wrapper->getReturnType())
|
|
Val = Builder.CreatePointerBitCastOrAddrSpaceCast(
|
|
Val, Wrapper->getReturnType(), "");
|
|
Builder.CreateRet(Val);
|
|
}
|
|
}
|
|
|
|
LValue ItaniumCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
|
|
const VarDecl *VD,
|
|
QualType LValType) {
|
|
llvm::Value *Val = CGF.CGM.GetAddrOfGlobalVar(VD);
|
|
llvm::Function *Wrapper = getOrCreateThreadLocalWrapper(VD, Val);
|
|
|
|
llvm::CallInst *CallVal = CGF.Builder.CreateCall(Wrapper);
|
|
CallVal->setCallingConv(Wrapper->getCallingConv());
|
|
|
|
LValue LV;
|
|
if (VD->getType()->isReferenceType())
|
|
LV = CGF.MakeNaturalAlignAddrLValue(CallVal, LValType);
|
|
else
|
|
LV = CGF.MakeAddrLValue(CallVal, LValType,
|
|
CGF.getContext().getDeclAlign(VD));
|
|
// FIXME: need setObjCGCLValueClass?
|
|
return LV;
|
|
}
|
|
|
|
/// Return whether the given global decl needs a VTT parameter, which it does
|
|
/// if it's a base constructor or destructor with virtual bases.
|
|
bool ItaniumCXXABI::NeedsVTTParameter(GlobalDecl GD) {
|
|
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
|
|
|
|
// We don't have any virtual bases, just return early.
|
|
if (!MD->getParent()->getNumVBases())
|
|
return false;
|
|
|
|
// Check if we have a base constructor.
|
|
if (isa<CXXConstructorDecl>(MD) && GD.getCtorType() == Ctor_Base)
|
|
return true;
|
|
|
|
// Check if we have a base destructor.
|
|
if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
namespace {
|
|
class ItaniumRTTIBuilder {
|
|
CodeGenModule &CGM; // Per-module state.
|
|
llvm::LLVMContext &VMContext;
|
|
const ItaniumCXXABI &CXXABI; // Per-module state.
|
|
|
|
/// Fields - The fields of the RTTI descriptor currently being built.
|
|
SmallVector<llvm::Constant *, 16> Fields;
|
|
|
|
/// GetAddrOfTypeName - Returns the mangled type name of the given type.
|
|
llvm::GlobalVariable *
|
|
GetAddrOfTypeName(QualType Ty, llvm::GlobalVariable::LinkageTypes Linkage);
|
|
|
|
/// GetAddrOfExternalRTTIDescriptor - Returns the constant for the RTTI
|
|
/// descriptor of the given type.
|
|
llvm::Constant *GetAddrOfExternalRTTIDescriptor(QualType Ty);
|
|
|
|
/// BuildVTablePointer - Build the vtable pointer for the given type.
|
|
void BuildVTablePointer(const Type *Ty);
|
|
|
|
/// BuildSIClassTypeInfo - Build an abi::__si_class_type_info, used for single
|
|
/// inheritance, according to the Itanium C++ ABI, 2.9.5p6b.
|
|
void BuildSIClassTypeInfo(const CXXRecordDecl *RD);
|
|
|
|
/// BuildVMIClassTypeInfo - Build an abi::__vmi_class_type_info, used for
|
|
/// classes with bases that do not satisfy the abi::__si_class_type_info
|
|
/// constraints, according ti the Itanium C++ ABI, 2.9.5p5c.
|
|
void BuildVMIClassTypeInfo(const CXXRecordDecl *RD);
|
|
|
|
/// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct, used
|
|
/// for pointer types.
|
|
void BuildPointerTypeInfo(QualType PointeeTy);
|
|
|
|
/// BuildObjCObjectTypeInfo - Build the appropriate kind of
|
|
/// type_info for an object type.
|
|
void BuildObjCObjectTypeInfo(const ObjCObjectType *Ty);
|
|
|
|
/// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
|
|
/// struct, used for member pointer types.
|
|
void BuildPointerToMemberTypeInfo(const MemberPointerType *Ty);
|
|
|
|
public:
|
|
ItaniumRTTIBuilder(const ItaniumCXXABI &ABI)
|
|
: CGM(ABI.CGM), VMContext(CGM.getModule().getContext()), CXXABI(ABI) {}
|
|
|
|
// Pointer type info flags.
|
|
enum {
|
|
/// PTI_Const - Type has const qualifier.
|
|
PTI_Const = 0x1,
|
|
|
|
/// PTI_Volatile - Type has volatile qualifier.
|
|
PTI_Volatile = 0x2,
|
|
|
|
/// PTI_Restrict - Type has restrict qualifier.
|
|
PTI_Restrict = 0x4,
|
|
|
|
/// PTI_Incomplete - Type is incomplete.
|
|
PTI_Incomplete = 0x8,
|
|
|
|
/// PTI_ContainingClassIncomplete - Containing class is incomplete.
|
|
/// (in pointer to member).
|
|
PTI_ContainingClassIncomplete = 0x10,
|
|
|
|
/// PTI_TransactionSafe - Pointee is transaction_safe function (C++ TM TS).
|
|
//PTI_TransactionSafe = 0x20,
|
|
|
|
/// PTI_Noexcept - Pointee is noexcept function (C++1z).
|
|
PTI_Noexcept = 0x40,
|
|
};
|
|
|
|
// VMI type info flags.
|
|
enum {
|
|
/// VMI_NonDiamondRepeat - Class has non-diamond repeated inheritance.
|
|
VMI_NonDiamondRepeat = 0x1,
|
|
|
|
/// VMI_DiamondShaped - Class is diamond shaped.
|
|
VMI_DiamondShaped = 0x2
|
|
};
|
|
|
|
// Base class type info flags.
|
|
enum {
|
|
/// BCTI_Virtual - Base class is virtual.
|
|
BCTI_Virtual = 0x1,
|
|
|
|
/// BCTI_Public - Base class is public.
|
|
BCTI_Public = 0x2
|
|
};
|
|
|
|
/// BuildTypeInfo - Build the RTTI type info struct for the given type, or
|
|
/// link to an existing RTTI descriptor if one already exists.
|
|
llvm::Constant *BuildTypeInfo(QualType Ty);
|
|
|
|
/// BuildTypeInfo - Build the RTTI type info struct for the given type.
|
|
llvm::Constant *BuildTypeInfo(
|
|
QualType Ty,
|
|
llvm::GlobalVariable::LinkageTypes Linkage,
|
|
llvm::GlobalValue::VisibilityTypes Visibility,
|
|
llvm::GlobalValue::DLLStorageClassTypes DLLStorageClass);
|
|
};
|
|
}
|
|
|
|
llvm::GlobalVariable *ItaniumRTTIBuilder::GetAddrOfTypeName(
|
|
QualType Ty, llvm::GlobalVariable::LinkageTypes Linkage) {
|
|
SmallString<256> Name;
|
|
llvm::raw_svector_ostream Out(Name);
|
|
CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(Ty, Out);
|
|
|
|
// We know that the mangled name of the type starts at index 4 of the
|
|
// mangled name of the typename, so we can just index into it in order to
|
|
// get the mangled name of the type.
|
|
llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
|
|
Name.substr(4));
|
|
auto Align = CGM.getContext().getTypeAlignInChars(CGM.getContext().CharTy);
|
|
|
|
llvm::GlobalVariable *GV = CGM.CreateOrReplaceCXXRuntimeVariable(
|
|
Name, Init->getType(), Linkage, Align.getQuantity());
|
|
|
|
GV->setInitializer(Init);
|
|
|
|
return GV;
|
|
}
|
|
|
|
llvm::Constant *
|
|
ItaniumRTTIBuilder::GetAddrOfExternalRTTIDescriptor(QualType Ty) {
|
|
// Mangle the RTTI name.
|
|
SmallString<256> Name;
|
|
llvm::raw_svector_ostream Out(Name);
|
|
CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
|
|
|
|
// Look for an existing global.
|
|
llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name);
|
|
|
|
if (!GV) {
|
|
// Create a new global variable.
|
|
// Note for the future: If we would ever like to do deferred emission of
|
|
// RTTI, check if emitting vtables opportunistically need any adjustment.
|
|
|
|
GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
|
|
/*isConstant=*/true,
|
|
llvm::GlobalValue::ExternalLinkage, nullptr,
|
|
Name);
|
|
const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
|
|
CGM.setGVProperties(GV, RD);
|
|
}
|
|
|
|
return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
|
|
}
|
|
|
|
/// TypeInfoIsInStandardLibrary - Given a builtin type, returns whether the type
|
|
/// info for that type is defined in the standard library.
|
|
static bool TypeInfoIsInStandardLibrary(const BuiltinType *Ty) {
|
|
// Itanium C++ ABI 2.9.2:
|
|
// Basic type information (e.g. for "int", "bool", etc.) will be kept in
|
|
// the run-time support library. Specifically, the run-time support
|
|
// library should contain type_info objects for the types X, X* and
|
|
// X const*, for every X in: void, std::nullptr_t, bool, wchar_t, char,
|
|
// unsigned char, signed char, short, unsigned short, int, unsigned int,
|
|
// long, unsigned long, long long, unsigned long long, float, double,
|
|
// long double, char16_t, char32_t, and the IEEE 754r decimal and
|
|
// half-precision floating point types.
|
|
//
|
|
// GCC also emits RTTI for __int128.
|
|
// FIXME: We do not emit RTTI information for decimal types here.
|
|
|
|
// Types added here must also be added to EmitFundamentalRTTIDescriptors.
|
|
switch (Ty->getKind()) {
|
|
case BuiltinType::Void:
|
|
case BuiltinType::NullPtr:
|
|
case BuiltinType::Bool:
|
|
case BuiltinType::WChar_S:
|
|
case BuiltinType::WChar_U:
|
|
case BuiltinType::Char_U:
|
|
case BuiltinType::Char_S:
|
|
case BuiltinType::UChar:
|
|
case BuiltinType::SChar:
|
|
case BuiltinType::Short:
|
|
case BuiltinType::UShort:
|
|
case BuiltinType::Int:
|
|
case BuiltinType::UInt:
|
|
case BuiltinType::Long:
|
|
case BuiltinType::ULong:
|
|
case BuiltinType::LongLong:
|
|
case BuiltinType::ULongLong:
|
|
case BuiltinType::Half:
|
|
case BuiltinType::Float:
|
|
case BuiltinType::Double:
|
|
case BuiltinType::LongDouble:
|
|
case BuiltinType::Float16:
|
|
case BuiltinType::Float128:
|
|
case BuiltinType::Char8:
|
|
case BuiltinType::Char16:
|
|
case BuiltinType::Char32:
|
|
case BuiltinType::Int128:
|
|
case BuiltinType::UInt128:
|
|
return true;
|
|
|
|
#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
|
|
case BuiltinType::Id:
|
|
#include "clang/Basic/OpenCLImageTypes.def"
|
|
#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
|
|
case BuiltinType::Id:
|
|
#include "clang/Basic/OpenCLExtensionTypes.def"
|
|
case BuiltinType::OCLSampler:
|
|
case BuiltinType::OCLEvent:
|
|
case BuiltinType::OCLClkEvent:
|
|
case BuiltinType::OCLQueue:
|
|
case BuiltinType::OCLReserveID:
|
|
#define SVE_TYPE(Name, Id, SingletonId) \
|
|
case BuiltinType::Id:
|
|
#include "clang/Basic/AArch64SVEACLETypes.def"
|
|
#define PPC_MMA_VECTOR_TYPE(Name, Id, Size) \
|
|
case BuiltinType::Id:
|
|
#include "clang/Basic/PPCTypes.def"
|
|
case BuiltinType::ShortAccum:
|
|
case BuiltinType::Accum:
|
|
case BuiltinType::LongAccum:
|
|
case BuiltinType::UShortAccum:
|
|
case BuiltinType::UAccum:
|
|
case BuiltinType::ULongAccum:
|
|
case BuiltinType::ShortFract:
|
|
case BuiltinType::Fract:
|
|
case BuiltinType::LongFract:
|
|
case BuiltinType::UShortFract:
|
|
case BuiltinType::UFract:
|
|
case BuiltinType::ULongFract:
|
|
case BuiltinType::SatShortAccum:
|
|
case BuiltinType::SatAccum:
|
|
case BuiltinType::SatLongAccum:
|
|
case BuiltinType::SatUShortAccum:
|
|
case BuiltinType::SatUAccum:
|
|
case BuiltinType::SatULongAccum:
|
|
case BuiltinType::SatShortFract:
|
|
case BuiltinType::SatFract:
|
|
case BuiltinType::SatLongFract:
|
|
case BuiltinType::SatUShortFract:
|
|
case BuiltinType::SatUFract:
|
|
case BuiltinType::SatULongFract:
|
|
case BuiltinType::BFloat16:
|
|
return false;
|
|
|
|
case BuiltinType::Dependent:
|
|
#define BUILTIN_TYPE(Id, SingletonId)
|
|
#define PLACEHOLDER_TYPE(Id, SingletonId) \
|
|
case BuiltinType::Id:
|
|
#include "clang/AST/BuiltinTypes.def"
|
|
llvm_unreachable("asking for RRTI for a placeholder type!");
|
|
|
|
case BuiltinType::ObjCId:
|
|
case BuiltinType::ObjCClass:
|
|
case BuiltinType::ObjCSel:
|
|
llvm_unreachable("FIXME: Objective-C types are unsupported!");
|
|
}
|
|
|
|
llvm_unreachable("Invalid BuiltinType Kind!");
|
|
}
|
|
|
|
static bool TypeInfoIsInStandardLibrary(const PointerType *PointerTy) {
|
|
QualType PointeeTy = PointerTy->getPointeeType();
|
|
const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(PointeeTy);
|
|
if (!BuiltinTy)
|
|
return false;
|
|
|
|
// Check the qualifiers.
|
|
Qualifiers Quals = PointeeTy.getQualifiers();
|
|
Quals.removeConst();
|
|
|
|
if (!Quals.empty())
|
|
return false;
|
|
|
|
return TypeInfoIsInStandardLibrary(BuiltinTy);
|
|
}
|
|
|
|
/// IsStandardLibraryRTTIDescriptor - Returns whether the type
|
|
/// information for the given type exists in the standard library.
|
|
static bool IsStandardLibraryRTTIDescriptor(QualType Ty) {
|
|
// Type info for builtin types is defined in the standard library.
|
|
if (const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(Ty))
|
|
return TypeInfoIsInStandardLibrary(BuiltinTy);
|
|
|
|
// Type info for some pointer types to builtin types is defined in the
|
|
// standard library.
|
|
if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
|
|
return TypeInfoIsInStandardLibrary(PointerTy);
|
|
|
|
return false;
|
|
}
|
|
|
|
/// ShouldUseExternalRTTIDescriptor - Returns whether the type information for
|
|
/// the given type exists somewhere else, and that we should not emit the type
|
|
/// information in this translation unit. Assumes that it is not a
|
|
/// standard-library type.
|
|
static bool ShouldUseExternalRTTIDescriptor(CodeGenModule &CGM,
|
|
QualType Ty) {
|
|
ASTContext &Context = CGM.getContext();
|
|
|
|
// If RTTI is disabled, assume it might be disabled in the
|
|
// translation unit that defines any potential key function, too.
|
|
if (!Context.getLangOpts().RTTI) return false;
|
|
|
|
if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
|
|
const CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
|
|
if (!RD->hasDefinition())
|
|
return false;
|
|
|
|
if (!RD->isDynamicClass())
|
|
return false;
|
|
|
|
// FIXME: this may need to be reconsidered if the key function
|
|
// changes.
|
|
// N.B. We must always emit the RTTI data ourselves if there exists a key
|
|
// function.
|
|
bool IsDLLImport = RD->hasAttr<DLLImportAttr>();
|
|
|
|
// Don't import the RTTI but emit it locally.
|
|
if (CGM.getTriple().isWindowsGNUEnvironment())
|
|
return false;
|
|
|
|
if (CGM.getVTables().isVTableExternal(RD))
|
|
return IsDLLImport && !CGM.getTriple().isWindowsItaniumEnvironment()
|
|
? false
|
|
: true;
|
|
|
|
if (IsDLLImport)
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/// IsIncompleteClassType - Returns whether the given record type is incomplete.
|
|
static bool IsIncompleteClassType(const RecordType *RecordTy) {
|
|
return !RecordTy->getDecl()->isCompleteDefinition();
|
|
}
|
|
|
|
/// ContainsIncompleteClassType - Returns whether the given type contains an
|
|
/// incomplete class type. This is true if
|
|
///
|
|
/// * The given type is an incomplete class type.
|
|
/// * The given type is a pointer type whose pointee type contains an
|
|
/// incomplete class type.
|
|
/// * The given type is a member pointer type whose class is an incomplete
|
|
/// class type.
|
|
/// * The given type is a member pointer type whoise pointee type contains an
|
|
/// incomplete class type.
|
|
/// is an indirect or direct pointer to an incomplete class type.
|
|
static bool ContainsIncompleteClassType(QualType Ty) {
|
|
if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
|
|
if (IsIncompleteClassType(RecordTy))
|
|
return true;
|
|
}
|
|
|
|
if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
|
|
return ContainsIncompleteClassType(PointerTy->getPointeeType());
|
|
|
|
if (const MemberPointerType *MemberPointerTy =
|
|
dyn_cast<MemberPointerType>(Ty)) {
|
|
// Check if the class type is incomplete.
|
|
const RecordType *ClassType = cast<RecordType>(MemberPointerTy->getClass());
|
|
if (IsIncompleteClassType(ClassType))
|
|
return true;
|
|
|
|
return ContainsIncompleteClassType(MemberPointerTy->getPointeeType());
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// CanUseSingleInheritance - Return whether the given record decl has a "single,
|
|
// public, non-virtual base at offset zero (i.e. the derived class is dynamic
|
|
// iff the base is)", according to Itanium C++ ABI, 2.95p6b.
|
|
static bool CanUseSingleInheritance(const CXXRecordDecl *RD) {
|
|
// Check the number of bases.
|
|
if (RD->getNumBases() != 1)
|
|
return false;
|
|
|
|
// Get the base.
|
|
CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin();
|
|
|
|
// Check that the base is not virtual.
|
|
if (Base->isVirtual())
|
|
return false;
|
|
|
|
// Check that the base is public.
|
|
if (Base->getAccessSpecifier() != AS_public)
|
|
return false;
|
|
|
|
// Check that the class is dynamic iff the base is.
|
|
auto *BaseDecl =
|
|
cast<CXXRecordDecl>(Base->getType()->castAs<RecordType>()->getDecl());
|
|
if (!BaseDecl->isEmpty() &&
|
|
BaseDecl->isDynamicClass() != RD->isDynamicClass())
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
void ItaniumRTTIBuilder::BuildVTablePointer(const Type *Ty) {
|
|
// abi::__class_type_info.
|
|
static const char * const ClassTypeInfo =
|
|
"_ZTVN10__cxxabiv117__class_type_infoE";
|
|
// abi::__si_class_type_info.
|
|
static const char * const SIClassTypeInfo =
|
|
"_ZTVN10__cxxabiv120__si_class_type_infoE";
|
|
// abi::__vmi_class_type_info.
|
|
static const char * const VMIClassTypeInfo =
|
|
"_ZTVN10__cxxabiv121__vmi_class_type_infoE";
|
|
|
|
const char *VTableName = nullptr;
|
|
|
|
switch (Ty->getTypeClass()) {
|
|
#define TYPE(Class, Base)
|
|
#define ABSTRACT_TYPE(Class, Base)
|
|
#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
|
|
#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
|
|
#define DEPENDENT_TYPE(Class, Base) case Type::Class:
|
|
#include "clang/AST/TypeNodes.inc"
|
|
llvm_unreachable("Non-canonical and dependent types shouldn't get here");
|
|
|
|
case Type::LValueReference:
|
|
case Type::RValueReference:
|
|
llvm_unreachable("References shouldn't get here");
|
|
|
|
case Type::Auto:
|
|
case Type::DeducedTemplateSpecialization:
|
|
llvm_unreachable("Undeduced type shouldn't get here");
|
|
|
|
case Type::Pipe:
|
|
llvm_unreachable("Pipe types shouldn't get here");
|
|
|
|
case Type::Builtin:
|
|
case Type::ExtInt:
|
|
// GCC treats vector and complex types as fundamental types.
|
|
case Type::Vector:
|
|
case Type::ExtVector:
|
|
case Type::ConstantMatrix:
|
|
case Type::Complex:
|
|
case Type::Atomic:
|
|
// FIXME: GCC treats block pointers as fundamental types?!
|
|
case Type::BlockPointer:
|
|
// abi::__fundamental_type_info.
|
|
VTableName = "_ZTVN10__cxxabiv123__fundamental_type_infoE";
|
|
break;
|
|
|
|
case Type::ConstantArray:
|
|
case Type::IncompleteArray:
|
|
case Type::VariableArray:
|
|
// abi::__array_type_info.
|
|
VTableName = "_ZTVN10__cxxabiv117__array_type_infoE";
|
|
break;
|
|
|
|
case Type::FunctionNoProto:
|
|
case Type::FunctionProto:
|
|
// abi::__function_type_info.
|
|
VTableName = "_ZTVN10__cxxabiv120__function_type_infoE";
|
|
break;
|
|
|
|
case Type::Enum:
|
|
// abi::__enum_type_info.
|
|
VTableName = "_ZTVN10__cxxabiv116__enum_type_infoE";
|
|
break;
|
|
|
|
case Type::Record: {
|
|
const CXXRecordDecl *RD =
|
|
cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
|
|
|
|
if (!RD->hasDefinition() || !RD->getNumBases()) {
|
|
VTableName = ClassTypeInfo;
|
|
} else if (CanUseSingleInheritance(RD)) {
|
|
VTableName = SIClassTypeInfo;
|
|
} else {
|
|
VTableName = VMIClassTypeInfo;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
case Type::ObjCObject:
|
|
// Ignore protocol qualifiers.
|
|
Ty = cast<ObjCObjectType>(Ty)->getBaseType().getTypePtr();
|
|
|
|
// Handle id and Class.
|
|
if (isa<BuiltinType>(Ty)) {
|
|
VTableName = ClassTypeInfo;
|
|
break;
|
|
}
|
|
|
|
assert(isa<ObjCInterfaceType>(Ty));
|
|
LLVM_FALLTHROUGH;
|
|
|
|
case Type::ObjCInterface:
|
|
if (cast<ObjCInterfaceType>(Ty)->getDecl()->getSuperClass()) {
|
|
VTableName = SIClassTypeInfo;
|
|
} else {
|
|
VTableName = ClassTypeInfo;
|
|
}
|
|
break;
|
|
|
|
case Type::ObjCObjectPointer:
|
|
case Type::Pointer:
|
|
// abi::__pointer_type_info.
|
|
VTableName = "_ZTVN10__cxxabiv119__pointer_type_infoE";
|
|
break;
|
|
|
|
case Type::MemberPointer:
|
|
// abi::__pointer_to_member_type_info.
|
|
VTableName = "_ZTVN10__cxxabiv129__pointer_to_member_type_infoE";
|
|
break;
|
|
}
|
|
|
|
llvm::Constant *VTable = nullptr;
|
|
|
|
// Check if the alias exists. If it doesn't, then get or create the global.
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout())
|
|
VTable = CGM.getModule().getNamedAlias(VTableName);
|
|
if (!VTable)
|
|
VTable = CGM.getModule().getOrInsertGlobal(VTableName, CGM.Int8PtrTy);
|
|
|
|
CGM.setDSOLocal(cast<llvm::GlobalValue>(VTable->stripPointerCasts()));
|
|
|
|
llvm::Type *PtrDiffTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType());
|
|
|
|
// The vtable address point is 2.
|
|
if (CGM.getItaniumVTableContext().isRelativeLayout()) {
|
|
// The vtable address point is 8 bytes after its start:
|
|
// 4 for the offset to top + 4 for the relative offset to rtti.
|
|
llvm::Constant *Eight = llvm::ConstantInt::get(CGM.Int32Ty, 8);
|
|
VTable = llvm::ConstantExpr::getBitCast(VTable, CGM.Int8PtrTy);
|
|
VTable =
|
|
llvm::ConstantExpr::getInBoundsGetElementPtr(CGM.Int8Ty, VTable, Eight);
|
|
} else {
|
|
llvm::Constant *Two = llvm::ConstantInt::get(PtrDiffTy, 2);
|
|
VTable = llvm::ConstantExpr::getInBoundsGetElementPtr(CGM.Int8PtrTy, VTable,
|
|
Two);
|
|
}
|
|
VTable = llvm::ConstantExpr::getBitCast(VTable, CGM.Int8PtrTy);
|
|
|
|
Fields.push_back(VTable);
|
|
}
|
|
|
|
/// Return the linkage that the type info and type info name constants
|
|
/// should have for the given type.
|
|
static llvm::GlobalVariable::LinkageTypes getTypeInfoLinkage(CodeGenModule &CGM,
|
|
QualType Ty) {
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// In addition, it and all of the intermediate abi::__pointer_type_info
|
|
// structs in the chain down to the abi::__class_type_info for the
|
|
// incomplete class type must be prevented from resolving to the
|
|
// corresponding type_info structs for the complete class type, possibly
|
|
// by making them local static objects. Finally, a dummy class RTTI is
|
|
// generated for the incomplete type that will not resolve to the final
|
|
// complete class RTTI (because the latter need not exist), possibly by
|
|
// making it a local static object.
|
|
if (ContainsIncompleteClassType(Ty))
|
|
return llvm::GlobalValue::InternalLinkage;
|
|
|
|
switch (Ty->getLinkage()) {
|
|
case NoLinkage:
|
|
case InternalLinkage:
|
|
case UniqueExternalLinkage:
|
|
return llvm::GlobalValue::InternalLinkage;
|
|
|
|
case VisibleNoLinkage:
|
|
case ModuleInternalLinkage:
|
|
case ModuleLinkage:
|
|
case ExternalLinkage:
|
|
// RTTI is not enabled, which means that this type info struct is going
|
|
// to be used for exception handling. Give it linkonce_odr linkage.
|
|
if (!CGM.getLangOpts().RTTI)
|
|
return llvm::GlobalValue::LinkOnceODRLinkage;
|
|
|
|
if (const RecordType *Record = dyn_cast<RecordType>(Ty)) {
|
|
const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
|
|
if (RD->hasAttr<WeakAttr>())
|
|
return llvm::GlobalValue::WeakODRLinkage;
|
|
if (CGM.getTriple().isWindowsItaniumEnvironment())
|
|
if (RD->hasAttr<DLLImportAttr>() &&
|
|
ShouldUseExternalRTTIDescriptor(CGM, Ty))
|
|
return llvm::GlobalValue::ExternalLinkage;
|
|
// MinGW always uses LinkOnceODRLinkage for type info.
|
|
if (RD->isDynamicClass() &&
|
|
!CGM.getContext()
|
|
.getTargetInfo()
|
|
.getTriple()
|
|
.isWindowsGNUEnvironment())
|
|
return CGM.getVTableLinkage(RD);
|
|
}
|
|
|
|
return llvm::GlobalValue::LinkOnceODRLinkage;
|
|
}
|
|
|
|
llvm_unreachable("Invalid linkage!");
|
|
}
|
|
|
|
llvm::Constant *ItaniumRTTIBuilder::BuildTypeInfo(QualType Ty) {
|
|
// We want to operate on the canonical type.
|
|
Ty = Ty.getCanonicalType();
|
|
|
|
// Check if we've already emitted an RTTI descriptor for this type.
|
|
SmallString<256> Name;
|
|
llvm::raw_svector_ostream Out(Name);
|
|
CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
|
|
|
|
llvm::GlobalVariable *OldGV = CGM.getModule().getNamedGlobal(Name);
|
|
if (OldGV && !OldGV->isDeclaration()) {
|
|
assert(!OldGV->hasAvailableExternallyLinkage() &&
|
|
"available_externally typeinfos not yet implemented");
|
|
|
|
return llvm::ConstantExpr::getBitCast(OldGV, CGM.Int8PtrTy);
|
|
}
|
|
|
|
// Check if there is already an external RTTI descriptor for this type.
|
|
if (IsStandardLibraryRTTIDescriptor(Ty) ||
|
|
ShouldUseExternalRTTIDescriptor(CGM, Ty))
|
|
return GetAddrOfExternalRTTIDescriptor(Ty);
|
|
|
|
// Emit the standard library with external linkage.
|
|
llvm::GlobalVariable::LinkageTypes Linkage = getTypeInfoLinkage(CGM, Ty);
|
|
|
|
// Give the type_info object and name the formal visibility of the
|
|
// type itself.
|
|
llvm::GlobalValue::VisibilityTypes llvmVisibility;
|
|
if (llvm::GlobalValue::isLocalLinkage(Linkage))
|
|
// If the linkage is local, only default visibility makes sense.
|
|
llvmVisibility = llvm::GlobalValue::DefaultVisibility;
|
|
else if (CXXABI.classifyRTTIUniqueness(Ty, Linkage) ==
|
|
ItaniumCXXABI::RUK_NonUniqueHidden)
|
|
llvmVisibility = llvm::GlobalValue::HiddenVisibility;
|
|
else
|
|
llvmVisibility = CodeGenModule::GetLLVMVisibility(Ty->getVisibility());
|
|
|
|
llvm::GlobalValue::DLLStorageClassTypes DLLStorageClass =
|
|
llvm::GlobalValue::DefaultStorageClass;
|
|
if (CGM.getTriple().isWindowsItaniumEnvironment()) {
|
|
auto RD = Ty->getAsCXXRecordDecl();
|
|
if (RD && RD->hasAttr<DLLExportAttr>())
|
|
DLLStorageClass = llvm::GlobalValue::DLLExportStorageClass;
|
|
}
|
|
|
|
return BuildTypeInfo(Ty, Linkage, llvmVisibility, DLLStorageClass);
|
|
}
|
|
|
|
llvm::Constant *ItaniumRTTIBuilder::BuildTypeInfo(
|
|
QualType Ty,
|
|
llvm::GlobalVariable::LinkageTypes Linkage,
|
|
llvm::GlobalValue::VisibilityTypes Visibility,
|
|
llvm::GlobalValue::DLLStorageClassTypes DLLStorageClass) {
|
|
// Add the vtable pointer.
|
|
BuildVTablePointer(cast<Type>(Ty));
|
|
|
|
// And the name.
|
|
llvm::GlobalVariable *TypeName = GetAddrOfTypeName(Ty, Linkage);
|
|
llvm::Constant *TypeNameField;
|
|
|
|
// If we're supposed to demote the visibility, be sure to set a flag
|
|
// to use a string comparison for type_info comparisons.
|
|
ItaniumCXXABI::RTTIUniquenessKind RTTIUniqueness =
|
|
CXXABI.classifyRTTIUniqueness(Ty, Linkage);
|
|
if (RTTIUniqueness != ItaniumCXXABI::RUK_Unique) {
|
|
// The flag is the sign bit, which on ARM64 is defined to be clear
|
|
// for global pointers. This is very ARM64-specific.
|
|
TypeNameField = llvm::ConstantExpr::getPtrToInt(TypeName, CGM.Int64Ty);
|
|
llvm::Constant *flag =
|
|
llvm::ConstantInt::get(CGM.Int64Ty, ((uint64_t)1) << 63);
|
|
TypeNameField = llvm::ConstantExpr::getAdd(TypeNameField, flag);
|
|
TypeNameField =
|
|
llvm::ConstantExpr::getIntToPtr(TypeNameField, CGM.Int8PtrTy);
|
|
} else {
|
|
TypeNameField = llvm::ConstantExpr::getBitCast(TypeName, CGM.Int8PtrTy);
|
|
}
|
|
Fields.push_back(TypeNameField);
|
|
|
|
switch (Ty->getTypeClass()) {
|
|
#define TYPE(Class, Base)
|
|
#define ABSTRACT_TYPE(Class, Base)
|
|
#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
|
|
#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
|
|
#define DEPENDENT_TYPE(Class, Base) case Type::Class:
|
|
#include "clang/AST/TypeNodes.inc"
|
|
llvm_unreachable("Non-canonical and dependent types shouldn't get here");
|
|
|
|
// GCC treats vector types as fundamental types.
|
|
case Type::Builtin:
|
|
case Type::Vector:
|
|
case Type::ExtVector:
|
|
case Type::ConstantMatrix:
|
|
case Type::Complex:
|
|
case Type::BlockPointer:
|
|
// Itanium C++ ABI 2.9.5p4:
|
|
// abi::__fundamental_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::LValueReference:
|
|
case Type::RValueReference:
|
|
llvm_unreachable("References shouldn't get here");
|
|
|
|
case Type::Auto:
|
|
case Type::DeducedTemplateSpecialization:
|
|
llvm_unreachable("Undeduced type shouldn't get here");
|
|
|
|
case Type::Pipe:
|
|
break;
|
|
|
|
case Type::ExtInt:
|
|
break;
|
|
|
|
case Type::ConstantArray:
|
|
case Type::IncompleteArray:
|
|
case Type::VariableArray:
|
|
// Itanium C++ ABI 2.9.5p5:
|
|
// abi::__array_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::FunctionNoProto:
|
|
case Type::FunctionProto:
|
|
// Itanium C++ ABI 2.9.5p5:
|
|
// abi::__function_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::Enum:
|
|
// Itanium C++ ABI 2.9.5p5:
|
|
// abi::__enum_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::Record: {
|
|
const CXXRecordDecl *RD =
|
|
cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
|
|
if (!RD->hasDefinition() || !RD->getNumBases()) {
|
|
// We don't need to emit any fields.
|
|
break;
|
|
}
|
|
|
|
if (CanUseSingleInheritance(RD))
|
|
BuildSIClassTypeInfo(RD);
|
|
else
|
|
BuildVMIClassTypeInfo(RD);
|
|
|
|
break;
|
|
}
|
|
|
|
case Type::ObjCObject:
|
|
case Type::ObjCInterface:
|
|
BuildObjCObjectTypeInfo(cast<ObjCObjectType>(Ty));
|
|
break;
|
|
|
|
case Type::ObjCObjectPointer:
|
|
BuildPointerTypeInfo(cast<ObjCObjectPointerType>(Ty)->getPointeeType());
|
|
break;
|
|
|
|
case Type::Pointer:
|
|
BuildPointerTypeInfo(cast<PointerType>(Ty)->getPointeeType());
|
|
break;
|
|
|
|
case Type::MemberPointer:
|
|
BuildPointerToMemberTypeInfo(cast<MemberPointerType>(Ty));
|
|
break;
|
|
|
|
case Type::Atomic:
|
|
// No fields, at least for the moment.
|
|
break;
|
|
}
|
|
|
|
llvm::Constant *Init = llvm::ConstantStruct::getAnon(Fields);
|
|
|
|
SmallString<256> Name;
|
|
llvm::raw_svector_ostream Out(Name);
|
|
CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
|
|
llvm::Module &M = CGM.getModule();
|
|
llvm::GlobalVariable *OldGV = M.getNamedGlobal(Name);
|
|
llvm::GlobalVariable *GV =
|
|
new llvm::GlobalVariable(M, Init->getType(),
|
|
/*isConstant=*/true, Linkage, Init, Name);
|
|
|
|
// If there's already an old global variable, replace it with the new one.
|
|
if (OldGV) {
|
|
GV->takeName(OldGV);
|
|
llvm::Constant *NewPtr =
|
|
llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
|
|
OldGV->replaceAllUsesWith(NewPtr);
|
|
OldGV->eraseFromParent();
|
|
}
|
|
|
|
if (CGM.supportsCOMDAT() && GV->isWeakForLinker())
|
|
GV->setComdat(M.getOrInsertComdat(GV->getName()));
|
|
|
|
CharUnits Align =
|
|
CGM.getContext().toCharUnitsFromBits(CGM.getTarget().getPointerAlign(0));
|
|
GV->setAlignment(Align.getAsAlign());
|
|
|
|
// The Itanium ABI specifies that type_info objects must be globally
|
|
// unique, with one exception: if the type is an incomplete class
|
|
// type or a (possibly indirect) pointer to one. That exception
|
|
// affects the general case of comparing type_info objects produced
|
|
// by the typeid operator, which is why the comparison operators on
|
|
// std::type_info generally use the type_info name pointers instead
|
|
// of the object addresses. However, the language's built-in uses
|
|
// of RTTI generally require class types to be complete, even when
|
|
// manipulating pointers to those class types. This allows the
|
|
// implementation of dynamic_cast to rely on address equality tests,
|
|
// which is much faster.
|
|
|
|
// All of this is to say that it's important that both the type_info
|
|
// object and the type_info name be uniqued when weakly emitted.
|
|
|
|
TypeName->setVisibility(Visibility);
|
|
CGM.setDSOLocal(TypeName);
|
|
|
|
GV->setVisibility(Visibility);
|
|
CGM.setDSOLocal(GV);
|
|
|
|
TypeName->setDLLStorageClass(DLLStorageClass);
|
|
GV->setDLLStorageClass(DLLStorageClass);
|
|
|
|
TypeName->setPartition(CGM.getCodeGenOpts().SymbolPartition);
|
|
GV->setPartition(CGM.getCodeGenOpts().SymbolPartition);
|
|
|
|
return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
|
|
}
|
|
|
|
/// BuildObjCObjectTypeInfo - Build the appropriate kind of type_info
|
|
/// for the given Objective-C object type.
|
|
void ItaniumRTTIBuilder::BuildObjCObjectTypeInfo(const ObjCObjectType *OT) {
|
|
// Drop qualifiers.
|
|
const Type *T = OT->getBaseType().getTypePtr();
|
|
assert(isa<BuiltinType>(T) || isa<ObjCInterfaceType>(T));
|
|
|
|
// The builtin types are abi::__class_type_infos and don't require
|
|
// extra fields.
|
|
if (isa<BuiltinType>(T)) return;
|
|
|
|
ObjCInterfaceDecl *Class = cast<ObjCInterfaceType>(T)->getDecl();
|
|
ObjCInterfaceDecl *Super = Class->getSuperClass();
|
|
|
|
// Root classes are also __class_type_info.
|
|
if (!Super) return;
|
|
|
|
QualType SuperTy = CGM.getContext().getObjCInterfaceType(Super);
|
|
|
|
// Everything else is single inheritance.
|
|
llvm::Constant *BaseTypeInfo =
|
|
ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(SuperTy);
|
|
Fields.push_back(BaseTypeInfo);
|
|
}
|
|
|
|
/// BuildSIClassTypeInfo - Build an abi::__si_class_type_info, used for single
|
|
/// inheritance, according to the Itanium C++ ABI, 2.95p6b.
|
|
void ItaniumRTTIBuilder::BuildSIClassTypeInfo(const CXXRecordDecl *RD) {
|
|
// Itanium C++ ABI 2.9.5p6b:
|
|
// It adds to abi::__class_type_info a single member pointing to the
|
|
// type_info structure for the base type,
|
|
llvm::Constant *BaseTypeInfo =
|
|
ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(RD->bases_begin()->getType());
|
|
Fields.push_back(BaseTypeInfo);
|
|
}
|
|
|
|
namespace {
|
|
/// SeenBases - Contains virtual and non-virtual bases seen when traversing
|
|
/// a class hierarchy.
|
|
struct SeenBases {
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 16> NonVirtualBases;
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 16> VirtualBases;
|
|
};
|
|
}
|
|
|
|
/// ComputeVMIClassTypeInfoFlags - Compute the value of the flags member in
|
|
/// abi::__vmi_class_type_info.
|
|
///
|
|
static unsigned ComputeVMIClassTypeInfoFlags(const CXXBaseSpecifier *Base,
|
|
SeenBases &Bases) {
|
|
|
|
unsigned Flags = 0;
|
|
|
|
auto *BaseDecl =
|
|
cast<CXXRecordDecl>(Base->getType()->castAs<RecordType>()->getDecl());
|
|
|
|
if (Base->isVirtual()) {
|
|
// Mark the virtual base as seen.
|
|
if (!Bases.VirtualBases.insert(BaseDecl).second) {
|
|
// If this virtual base has been seen before, then the class is diamond
|
|
// shaped.
|
|
Flags |= ItaniumRTTIBuilder::VMI_DiamondShaped;
|
|
} else {
|
|
if (Bases.NonVirtualBases.count(BaseDecl))
|
|
Flags |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
|
|
}
|
|
} else {
|
|
// Mark the non-virtual base as seen.
|
|
if (!Bases.NonVirtualBases.insert(BaseDecl).second) {
|
|
// If this non-virtual base has been seen before, then the class has non-
|
|
// diamond shaped repeated inheritance.
|
|
Flags |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
|
|
} else {
|
|
if (Bases.VirtualBases.count(BaseDecl))
|
|
Flags |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
|
|
}
|
|
}
|
|
|
|
// Walk all bases.
|
|
for (const auto &I : BaseDecl->bases())
|
|
Flags |= ComputeVMIClassTypeInfoFlags(&I, Bases);
|
|
|
|
return Flags;
|
|
}
|
|
|
|
static unsigned ComputeVMIClassTypeInfoFlags(const CXXRecordDecl *RD) {
|
|
unsigned Flags = 0;
|
|
SeenBases Bases;
|
|
|
|
// Walk all bases.
|
|
for (const auto &I : RD->bases())
|
|
Flags |= ComputeVMIClassTypeInfoFlags(&I, Bases);
|
|
|
|
return Flags;
|
|
}
|
|
|
|
/// BuildVMIClassTypeInfo - Build an abi::__vmi_class_type_info, used for
|
|
/// classes with bases that do not satisfy the abi::__si_class_type_info
|
|
/// constraints, according ti the Itanium C++ ABI, 2.9.5p5c.
|
|
void ItaniumRTTIBuilder::BuildVMIClassTypeInfo(const CXXRecordDecl *RD) {
|
|
llvm::Type *UnsignedIntLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
|
|
|
|
// Itanium C++ ABI 2.9.5p6c:
|
|
// __flags is a word with flags describing details about the class
|
|
// structure, which may be referenced by using the __flags_masks
|
|
// enumeration. These flags refer to both direct and indirect bases.
|
|
unsigned Flags = ComputeVMIClassTypeInfoFlags(RD);
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, Flags));
|
|
|
|
// Itanium C++ ABI 2.9.5p6c:
|
|
// __base_count is a word with the number of direct proper base class
|
|
// descriptions that follow.
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, RD->getNumBases()));
|
|
|
|
if (!RD->getNumBases())
|
|
return;
|
|
|
|
// Now add the base class descriptions.
|
|
|
|
// Itanium C++ ABI 2.9.5p6c:
|
|
// __base_info[] is an array of base class descriptions -- one for every
|
|
// direct proper base. Each description is of the type:
|
|
//
|
|
// struct abi::__base_class_type_info {
|
|
// public:
|
|
// const __class_type_info *__base_type;
|
|
// long __offset_flags;
|
|
//
|
|
// enum __offset_flags_masks {
|
|
// __virtual_mask = 0x1,
|
|
// __public_mask = 0x2,
|
|
// __offset_shift = 8
|
|
// };
|
|
// };
|
|
|
|
// If we're in mingw and 'long' isn't wide enough for a pointer, use 'long
|
|
// long' instead of 'long' for __offset_flags. libstdc++abi uses long long on
|
|
// LLP64 platforms.
|
|
// FIXME: Consider updating libc++abi to match, and extend this logic to all
|
|
// LLP64 platforms.
|
|
QualType OffsetFlagsTy = CGM.getContext().LongTy;
|
|
const TargetInfo &TI = CGM.getContext().getTargetInfo();
|
|
if (TI.getTriple().isOSCygMing() && TI.getPointerWidth(0) > TI.getLongWidth())
|
|
OffsetFlagsTy = CGM.getContext().LongLongTy;
|
|
llvm::Type *OffsetFlagsLTy =
|
|
CGM.getTypes().ConvertType(OffsetFlagsTy);
|
|
|
|
for (const auto &Base : RD->bases()) {
|
|
// The __base_type member points to the RTTI for the base type.
|
|
Fields.push_back(ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(Base.getType()));
|
|
|
|
auto *BaseDecl =
|
|
cast<CXXRecordDecl>(Base.getType()->castAs<RecordType>()->getDecl());
|
|
|
|
int64_t OffsetFlags = 0;
|
|
|
|
// All but the lower 8 bits of __offset_flags are a signed offset.
|
|
// For a non-virtual base, this is the offset in the object of the base
|
|
// subobject. For a virtual base, this is the offset in the virtual table of
|
|
// the virtual base offset for the virtual base referenced (negative).
|
|
CharUnits Offset;
|
|
if (Base.isVirtual())
|
|
Offset =
|
|
CGM.getItaniumVTableContext().getVirtualBaseOffsetOffset(RD, BaseDecl);
|
|
else {
|
|
const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
|
|
Offset = Layout.getBaseClassOffset(BaseDecl);
|
|
};
|
|
|
|
OffsetFlags = uint64_t(Offset.getQuantity()) << 8;
|
|
|
|
// The low-order byte of __offset_flags contains flags, as given by the
|
|
// masks from the enumeration __offset_flags_masks.
|
|
if (Base.isVirtual())
|
|
OffsetFlags |= BCTI_Virtual;
|
|
if (Base.getAccessSpecifier() == AS_public)
|
|
OffsetFlags |= BCTI_Public;
|
|
|
|
Fields.push_back(llvm::ConstantInt::get(OffsetFlagsLTy, OffsetFlags));
|
|
}
|
|
}
|
|
|
|
/// Compute the flags for a __pbase_type_info, and remove the corresponding
|
|
/// pieces from \p Type.
|
|
static unsigned extractPBaseFlags(ASTContext &Ctx, QualType &Type) {
|
|
unsigned Flags = 0;
|
|
|
|
if (Type.isConstQualified())
|
|
Flags |= ItaniumRTTIBuilder::PTI_Const;
|
|
if (Type.isVolatileQualified())
|
|
Flags |= ItaniumRTTIBuilder::PTI_Volatile;
|
|
if (Type.isRestrictQualified())
|
|
Flags |= ItaniumRTTIBuilder::PTI_Restrict;
|
|
Type = Type.getUnqualifiedType();
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// When the abi::__pbase_type_info is for a direct or indirect pointer to an
|
|
// incomplete class type, the incomplete target type flag is set.
|
|
if (ContainsIncompleteClassType(Type))
|
|
Flags |= ItaniumRTTIBuilder::PTI_Incomplete;
|
|
|
|
if (auto *Proto = Type->getAs<FunctionProtoType>()) {
|
|
if (Proto->isNothrow()) {
|
|
Flags |= ItaniumRTTIBuilder::PTI_Noexcept;
|
|
Type = Ctx.getFunctionTypeWithExceptionSpec(Type, EST_None);
|
|
}
|
|
}
|
|
|
|
return Flags;
|
|
}
|
|
|
|
/// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct,
|
|
/// used for pointer types.
|
|
void ItaniumRTTIBuilder::BuildPointerTypeInfo(QualType PointeeTy) {
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __flags is a flag word describing the cv-qualification and other
|
|
// attributes of the type pointed to
|
|
unsigned Flags = extractPBaseFlags(CGM.getContext(), PointeeTy);
|
|
|
|
llvm::Type *UnsignedIntLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, Flags));
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __pointee is a pointer to the std::type_info derivation for the
|
|
// unqualified type being pointed to.
|
|
llvm::Constant *PointeeTypeInfo =
|
|
ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(PointeeTy);
|
|
Fields.push_back(PointeeTypeInfo);
|
|
}
|
|
|
|
/// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
|
|
/// struct, used for member pointer types.
|
|
void
|
|
ItaniumRTTIBuilder::BuildPointerToMemberTypeInfo(const MemberPointerType *Ty) {
|
|
QualType PointeeTy = Ty->getPointeeType();
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __flags is a flag word describing the cv-qualification and other
|
|
// attributes of the type pointed to.
|
|
unsigned Flags = extractPBaseFlags(CGM.getContext(), PointeeTy);
|
|
|
|
const RecordType *ClassType = cast<RecordType>(Ty->getClass());
|
|
if (IsIncompleteClassType(ClassType))
|
|
Flags |= PTI_ContainingClassIncomplete;
|
|
|
|
llvm::Type *UnsignedIntLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, Flags));
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __pointee is a pointer to the std::type_info derivation for the
|
|
// unqualified type being pointed to.
|
|
llvm::Constant *PointeeTypeInfo =
|
|
ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(PointeeTy);
|
|
Fields.push_back(PointeeTypeInfo);
|
|
|
|
// Itanium C++ ABI 2.9.5p9:
|
|
// __context is a pointer to an abi::__class_type_info corresponding to the
|
|
// class type containing the member pointed to
|
|
// (e.g., the "A" in "int A::*").
|
|
Fields.push_back(
|
|
ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(QualType(ClassType, 0)));
|
|
}
|
|
|
|
llvm::Constant *ItaniumCXXABI::getAddrOfRTTIDescriptor(QualType Ty) {
|
|
return ItaniumRTTIBuilder(*this).BuildTypeInfo(Ty);
|
|
}
|
|
|
|
void ItaniumCXXABI::EmitFundamentalRTTIDescriptors(const CXXRecordDecl *RD) {
|
|
// Types added here must also be added to TypeInfoIsInStandardLibrary.
|
|
QualType FundamentalTypes[] = {
|
|
getContext().VoidTy, getContext().NullPtrTy,
|
|
getContext().BoolTy, getContext().WCharTy,
|
|
getContext().CharTy, getContext().UnsignedCharTy,
|
|
getContext().SignedCharTy, getContext().ShortTy,
|
|
getContext().UnsignedShortTy, getContext().IntTy,
|
|
getContext().UnsignedIntTy, getContext().LongTy,
|
|
getContext().UnsignedLongTy, getContext().LongLongTy,
|
|
getContext().UnsignedLongLongTy, getContext().Int128Ty,
|
|
getContext().UnsignedInt128Ty, getContext().HalfTy,
|
|
getContext().FloatTy, getContext().DoubleTy,
|
|
getContext().LongDoubleTy, getContext().Float128Ty,
|
|
getContext().Char8Ty, getContext().Char16Ty,
|
|
getContext().Char32Ty
|
|
};
|
|
llvm::GlobalValue::DLLStorageClassTypes DLLStorageClass =
|
|
RD->hasAttr<DLLExportAttr>()
|
|
? llvm::GlobalValue::DLLExportStorageClass
|
|
: llvm::GlobalValue::DefaultStorageClass;
|
|
llvm::GlobalValue::VisibilityTypes Visibility =
|
|
CodeGenModule::GetLLVMVisibility(RD->getVisibility());
|
|
for (const QualType &FundamentalType : FundamentalTypes) {
|
|
QualType PointerType = getContext().getPointerType(FundamentalType);
|
|
QualType PointerTypeConst = getContext().getPointerType(
|
|
FundamentalType.withConst());
|
|
for (QualType Type : {FundamentalType, PointerType, PointerTypeConst})
|
|
ItaniumRTTIBuilder(*this).BuildTypeInfo(
|
|
Type, llvm::GlobalValue::ExternalLinkage,
|
|
Visibility, DLLStorageClass);
|
|
}
|
|
}
|
|
|
|
/// What sort of uniqueness rules should we use for the RTTI for the
|
|
/// given type?
|
|
ItaniumCXXABI::RTTIUniquenessKind ItaniumCXXABI::classifyRTTIUniqueness(
|
|
QualType CanTy, llvm::GlobalValue::LinkageTypes Linkage) const {
|
|
if (shouldRTTIBeUnique())
|
|
return RUK_Unique;
|
|
|
|
// It's only necessary for linkonce_odr or weak_odr linkage.
|
|
if (Linkage != llvm::GlobalValue::LinkOnceODRLinkage &&
|
|
Linkage != llvm::GlobalValue::WeakODRLinkage)
|
|
return RUK_Unique;
|
|
|
|
// It's only necessary with default visibility.
|
|
if (CanTy->getVisibility() != DefaultVisibility)
|
|
return RUK_Unique;
|
|
|
|
// If we're not required to publish this symbol, hide it.
|
|
if (Linkage == llvm::GlobalValue::LinkOnceODRLinkage)
|
|
return RUK_NonUniqueHidden;
|
|
|
|
// If we're required to publish this symbol, as we might be under an
|
|
// explicit instantiation, leave it with default visibility but
|
|
// enable string-comparisons.
|
|
assert(Linkage == llvm::GlobalValue::WeakODRLinkage);
|
|
return RUK_NonUniqueVisible;
|
|
}
|
|
|
|
// Find out how to codegen the complete destructor and constructor
|
|
namespace {
|
|
enum class StructorCodegen { Emit, RAUW, Alias, COMDAT };
|
|
}
|
|
static StructorCodegen getCodegenToUse(CodeGenModule &CGM,
|
|
const CXXMethodDecl *MD) {
|
|
if (!CGM.getCodeGenOpts().CXXCtorDtorAliases)
|
|
return StructorCodegen::Emit;
|
|
|
|
// The complete and base structors are not equivalent if there are any virtual
|
|
// bases, so emit separate functions.
|
|
if (MD->getParent()->getNumVBases())
|
|
return StructorCodegen::Emit;
|
|
|
|
GlobalDecl AliasDecl;
|
|
if (const auto *DD = dyn_cast<CXXDestructorDecl>(MD)) {
|
|
AliasDecl = GlobalDecl(DD, Dtor_Complete);
|
|
} else {
|
|
const auto *CD = cast<CXXConstructorDecl>(MD);
|
|
AliasDecl = GlobalDecl(CD, Ctor_Complete);
|
|
}
|
|
llvm::GlobalValue::LinkageTypes Linkage = CGM.getFunctionLinkage(AliasDecl);
|
|
|
|
if (llvm::GlobalValue::isDiscardableIfUnused(Linkage))
|
|
return StructorCodegen::RAUW;
|
|
|
|
// FIXME: Should we allow available_externally aliases?
|
|
if (!llvm::GlobalAlias::isValidLinkage(Linkage))
|
|
return StructorCodegen::RAUW;
|
|
|
|
if (llvm::GlobalValue::isWeakForLinker(Linkage)) {
|
|
// Only ELF and wasm support COMDATs with arbitrary names (C5/D5).
|
|
if (CGM.getTarget().getTriple().isOSBinFormatELF() ||
|
|
CGM.getTarget().getTriple().isOSBinFormatWasm())
|
|
return StructorCodegen::COMDAT;
|
|
return StructorCodegen::Emit;
|
|
}
|
|
|
|
return StructorCodegen::Alias;
|
|
}
|
|
|
|
static void emitConstructorDestructorAlias(CodeGenModule &CGM,
|
|
GlobalDecl AliasDecl,
|
|
GlobalDecl TargetDecl) {
|
|
llvm::GlobalValue::LinkageTypes Linkage = CGM.getFunctionLinkage(AliasDecl);
|
|
|
|
StringRef MangledName = CGM.getMangledName(AliasDecl);
|
|
llvm::GlobalValue *Entry = CGM.GetGlobalValue(MangledName);
|
|
if (Entry && !Entry->isDeclaration())
|
|
return;
|
|
|
|
auto *Aliasee = cast<llvm::GlobalValue>(CGM.GetAddrOfGlobal(TargetDecl));
|
|
|
|
// Create the alias with no name.
|
|
auto *Alias = llvm::GlobalAlias::create(Linkage, "", Aliasee);
|
|
|
|
// Constructors and destructors are always unnamed_addr.
|
|
Alias->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
|
|
|
|
// Switch any previous uses to the alias.
|
|
if (Entry) {
|
|
assert(Entry->getType() == Aliasee->getType() &&
|
|
"declaration exists with different type");
|
|
Alias->takeName(Entry);
|
|
Entry->replaceAllUsesWith(Alias);
|
|
Entry->eraseFromParent();
|
|
} else {
|
|
Alias->setName(MangledName);
|
|
}
|
|
|
|
// Finally, set up the alias with its proper name and attributes.
|
|
CGM.SetCommonAttributes(AliasDecl, Alias);
|
|
}
|
|
|
|
void ItaniumCXXABI::emitCXXStructor(GlobalDecl GD) {
|
|
auto *MD = cast<CXXMethodDecl>(GD.getDecl());
|
|
auto *CD = dyn_cast<CXXConstructorDecl>(MD);
|
|
const CXXDestructorDecl *DD = CD ? nullptr : cast<CXXDestructorDecl>(MD);
|
|
|
|
StructorCodegen CGType = getCodegenToUse(CGM, MD);
|
|
|
|
if (CD ? GD.getCtorType() == Ctor_Complete
|
|
: GD.getDtorType() == Dtor_Complete) {
|
|
GlobalDecl BaseDecl;
|
|
if (CD)
|
|
BaseDecl = GD.getWithCtorType(Ctor_Base);
|
|
else
|
|
BaseDecl = GD.getWithDtorType(Dtor_Base);
|
|
|
|
if (CGType == StructorCodegen::Alias || CGType == StructorCodegen::COMDAT) {
|
|
emitConstructorDestructorAlias(CGM, GD, BaseDecl);
|
|
return;
|
|
}
|
|
|
|
if (CGType == StructorCodegen::RAUW) {
|
|
StringRef MangledName = CGM.getMangledName(GD);
|
|
auto *Aliasee = CGM.GetAddrOfGlobal(BaseDecl);
|
|
CGM.addReplacement(MangledName, Aliasee);
|
|
return;
|
|
}
|
|
}
|
|
|
|
// 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 (DD && GD.getDtorType() == Dtor_Base &&
|
|
CGType != StructorCodegen::COMDAT &&
|
|
!CGM.TryEmitBaseDestructorAsAlias(DD))
|
|
return;
|
|
|
|
// FIXME: The deleting destructor is equivalent to the selected operator
|
|
// delete if:
|
|
// * either the delete is a destroying operator delete or the destructor
|
|
// would be trivial if it weren't virtual,
|
|
// * the conversion from the 'this' parameter to the first parameter of the
|
|
// destructor is equivalent to a bitcast,
|
|
// * the destructor does not have an implicit "this" return, and
|
|
// * the operator delete has the same calling convention and IR function type
|
|
// as the destructor.
|
|
// In such cases we should try to emit the deleting dtor as an alias to the
|
|
// selected 'operator delete'.
|
|
|
|
llvm::Function *Fn = CGM.codegenCXXStructor(GD);
|
|
|
|
if (CGType == StructorCodegen::COMDAT) {
|
|
SmallString<256> Buffer;
|
|
llvm::raw_svector_ostream Out(Buffer);
|
|
if (DD)
|
|
getMangleContext().mangleCXXDtorComdat(DD, Out);
|
|
else
|
|
getMangleContext().mangleCXXCtorComdat(CD, Out);
|
|
llvm::Comdat *C = CGM.getModule().getOrInsertComdat(Out.str());
|
|
Fn->setComdat(C);
|
|
} else {
|
|
CGM.maybeSetTrivialComdat(*MD, *Fn);
|
|
}
|
|
}
|
|
|
|
static llvm::FunctionCallee getBeginCatchFn(CodeGenModule &CGM) {
|
|
// void *__cxa_begin_catch(void*);
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(
|
|
CGM.Int8PtrTy, CGM.Int8PtrTy, /*isVarArg=*/false);
|
|
|
|
return CGM.CreateRuntimeFunction(FTy, "__cxa_begin_catch");
|
|
}
|
|
|
|
static llvm::FunctionCallee getEndCatchFn(CodeGenModule &CGM) {
|
|
// void __cxa_end_catch();
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
|
|
|
|
return CGM.CreateRuntimeFunction(FTy, "__cxa_end_catch");
|
|
}
|
|
|
|
static llvm::FunctionCallee getGetExceptionPtrFn(CodeGenModule &CGM) {
|
|
// void *__cxa_get_exception_ptr(void*);
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(
|
|
CGM.Int8PtrTy, CGM.Int8PtrTy, /*isVarArg=*/false);
|
|
|
|
return CGM.CreateRuntimeFunction(FTy, "__cxa_get_exception_ptr");
|
|
}
|
|
|
|
namespace {
|
|
/// A cleanup to call __cxa_end_catch. In many cases, the caught
|
|
/// exception type lets us state definitively that the thrown exception
|
|
/// type does not have a destructor. In particular:
|
|
/// - Catch-alls tell us nothing, so we have to conservatively
|
|
/// assume that the thrown exception might have a destructor.
|
|
/// - Catches by reference behave according to their base types.
|
|
/// - Catches of non-record types will only trigger for exceptions
|
|
/// of non-record types, which never have destructors.
|
|
/// - Catches of record types can trigger for arbitrary subclasses
|
|
/// of the caught type, so we have to assume the actual thrown
|
|
/// exception type might have a throwing destructor, even if the
|
|
/// caught type's destructor is trivial or nothrow.
|
|
struct CallEndCatch final : EHScopeStack::Cleanup {
|
|
CallEndCatch(bool MightThrow) : MightThrow(MightThrow) {}
|
|
bool MightThrow;
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
if (!MightThrow) {
|
|
CGF.EmitNounwindRuntimeCall(getEndCatchFn(CGF.CGM));
|
|
return;
|
|
}
|
|
|
|
CGF.EmitRuntimeCallOrInvoke(getEndCatchFn(CGF.CGM));
|
|
}
|
|
};
|
|
}
|
|
|
|
/// Emits a call to __cxa_begin_catch and enters a cleanup to call
|
|
/// __cxa_end_catch.
|
|
///
|
|
/// \param EndMightThrow - true if __cxa_end_catch might throw
|
|
static llvm::Value *CallBeginCatch(CodeGenFunction &CGF,
|
|
llvm::Value *Exn,
|
|
bool EndMightThrow) {
|
|
llvm::CallInst *call =
|
|
CGF.EmitNounwindRuntimeCall(getBeginCatchFn(CGF.CGM), Exn);
|
|
|
|
CGF.EHStack.pushCleanup<CallEndCatch>(NormalAndEHCleanup, EndMightThrow);
|
|
|
|
return call;
|
|
}
|
|
|
|
/// A "special initializer" callback for initializing a catch
|
|
/// parameter during catch initialization.
|
|
static void InitCatchParam(CodeGenFunction &CGF,
|
|
const VarDecl &CatchParam,
|
|
Address ParamAddr,
|
|
SourceLocation Loc) {
|
|
// Load the exception from where the landing pad saved it.
|
|
llvm::Value *Exn = CGF.getExceptionFromSlot();
|
|
|
|
CanQualType CatchType =
|
|
CGF.CGM.getContext().getCanonicalType(CatchParam.getType());
|
|
llvm::Type *LLVMCatchTy = CGF.ConvertTypeForMem(CatchType);
|
|
|
|
// If we're catching by reference, we can just cast the object
|
|
// pointer to the appropriate pointer.
|
|
if (isa<ReferenceType>(CatchType)) {
|
|
QualType CaughtType = cast<ReferenceType>(CatchType)->getPointeeType();
|
|
bool EndCatchMightThrow = CaughtType->isRecordType();
|
|
|
|
// __cxa_begin_catch returns the adjusted object pointer.
|
|
llvm::Value *AdjustedExn = CallBeginCatch(CGF, Exn, EndCatchMightThrow);
|
|
|
|
// We have no way to tell the personality function that we're
|
|
// catching by reference, so if we're catching a pointer,
|
|
// __cxa_begin_catch will actually return that pointer by value.
|
|
if (const PointerType *PT = dyn_cast<PointerType>(CaughtType)) {
|
|
QualType PointeeType = PT->getPointeeType();
|
|
|
|
// When catching by reference, generally we should just ignore
|
|
// this by-value pointer and use the exception object instead.
|
|
if (!PointeeType->isRecordType()) {
|
|
|
|
// Exn points to the struct _Unwind_Exception header, which
|
|
// we have to skip past in order to reach the exception data.
|
|
unsigned HeaderSize =
|
|
CGF.CGM.getTargetCodeGenInfo().getSizeOfUnwindException();
|
|
AdjustedExn = CGF.Builder.CreateConstGEP1_32(Exn, HeaderSize);
|
|
|
|
// However, if we're catching a pointer-to-record type that won't
|
|
// work, because the personality function might have adjusted
|
|
// the pointer. There's actually no way for us to fully satisfy
|
|
// the language/ABI contract here: we can't use Exn because it
|
|
// might have the wrong adjustment, but we can't use the by-value
|
|
// pointer because it's off by a level of abstraction.
|
|
//
|
|
// The current solution is to dump the adjusted pointer into an
|
|
// alloca, which breaks language semantics (because changing the
|
|
// pointer doesn't change the exception) but at least works.
|
|
// The better solution would be to filter out non-exact matches
|
|
// and rethrow them, but this is tricky because the rethrow
|
|
// really needs to be catchable by other sites at this landing
|
|
// pad. The best solution is to fix the personality function.
|
|
} else {
|
|
// Pull the pointer for the reference type off.
|
|
llvm::Type *PtrTy =
|
|
cast<llvm::PointerType>(LLVMCatchTy)->getElementType();
|
|
|
|
// Create the temporary and write the adjusted pointer into it.
|
|
Address ExnPtrTmp =
|
|
CGF.CreateTempAlloca(PtrTy, CGF.getPointerAlign(), "exn.byref.tmp");
|
|
llvm::Value *Casted = CGF.Builder.CreateBitCast(AdjustedExn, PtrTy);
|
|
CGF.Builder.CreateStore(Casted, ExnPtrTmp);
|
|
|
|
// Bind the reference to the temporary.
|
|
AdjustedExn = ExnPtrTmp.getPointer();
|
|
}
|
|
}
|
|
|
|
llvm::Value *ExnCast =
|
|
CGF.Builder.CreateBitCast(AdjustedExn, LLVMCatchTy, "exn.byref");
|
|
CGF.Builder.CreateStore(ExnCast, ParamAddr);
|
|
return;
|
|
}
|
|
|
|
// Scalars and complexes.
|
|
TypeEvaluationKind TEK = CGF.getEvaluationKind(CatchType);
|
|
if (TEK != TEK_Aggregate) {
|
|
llvm::Value *AdjustedExn = CallBeginCatch(CGF, Exn, false);
|
|
|
|
// If the catch type is a pointer type, __cxa_begin_catch returns
|
|
// the pointer by value.
|
|
if (CatchType->hasPointerRepresentation()) {
|
|
llvm::Value *CastExn =
|
|
CGF.Builder.CreateBitCast(AdjustedExn, LLVMCatchTy, "exn.casted");
|
|
|
|
switch (CatchType.getQualifiers().getObjCLifetime()) {
|
|
case Qualifiers::OCL_Strong:
|
|
CastExn = CGF.EmitARCRetainNonBlock(CastExn);
|
|
LLVM_FALLTHROUGH;
|
|
|
|
case Qualifiers::OCL_None:
|
|
case Qualifiers::OCL_ExplicitNone:
|
|
case Qualifiers::OCL_Autoreleasing:
|
|
CGF.Builder.CreateStore(CastExn, ParamAddr);
|
|
return;
|
|
|
|
case Qualifiers::OCL_Weak:
|
|
CGF.EmitARCInitWeak(ParamAddr, CastExn);
|
|
return;
|
|
}
|
|
llvm_unreachable("bad ownership qualifier!");
|
|
}
|
|
|
|
// Otherwise, it returns a pointer into the exception object.
|
|
|
|
llvm::Type *PtrTy = LLVMCatchTy->getPointerTo(0); // addrspace 0 ok
|
|
llvm::Value *Cast = CGF.Builder.CreateBitCast(AdjustedExn, PtrTy);
|
|
|
|
LValue srcLV = CGF.MakeNaturalAlignAddrLValue(Cast, CatchType);
|
|
LValue destLV = CGF.MakeAddrLValue(ParamAddr, CatchType);
|
|
switch (TEK) {
|
|
case TEK_Complex:
|
|
CGF.EmitStoreOfComplex(CGF.EmitLoadOfComplex(srcLV, Loc), destLV,
|
|
/*init*/ true);
|
|
return;
|
|
case TEK_Scalar: {
|
|
llvm::Value *ExnLoad = CGF.EmitLoadOfScalar(srcLV, Loc);
|
|
CGF.EmitStoreOfScalar(ExnLoad, destLV, /*init*/ true);
|
|
return;
|
|
}
|
|
case TEK_Aggregate:
|
|
llvm_unreachable("evaluation kind filtered out!");
|
|
}
|
|
llvm_unreachable("bad evaluation kind");
|
|
}
|
|
|
|
assert(isa<RecordType>(CatchType) && "unexpected catch type!");
|
|
auto catchRD = CatchType->getAsCXXRecordDecl();
|
|
CharUnits caughtExnAlignment = CGF.CGM.getClassPointerAlignment(catchRD);
|
|
|
|
llvm::Type *PtrTy = LLVMCatchTy->getPointerTo(0); // addrspace 0 ok
|
|
|
|
// Check for a copy expression. If we don't have a copy expression,
|
|
// that means a trivial copy is okay.
|
|
const Expr *copyExpr = CatchParam.getInit();
|
|
if (!copyExpr) {
|
|
llvm::Value *rawAdjustedExn = CallBeginCatch(CGF, Exn, true);
|
|
Address adjustedExn(CGF.Builder.CreateBitCast(rawAdjustedExn, PtrTy),
|
|
caughtExnAlignment);
|
|
LValue Dest = CGF.MakeAddrLValue(ParamAddr, CatchType);
|
|
LValue Src = CGF.MakeAddrLValue(adjustedExn, CatchType);
|
|
CGF.EmitAggregateCopy(Dest, Src, CatchType, AggValueSlot::DoesNotOverlap);
|
|
return;
|
|
}
|
|
|
|
// We have to call __cxa_get_exception_ptr to get the adjusted
|
|
// pointer before copying.
|
|
llvm::CallInst *rawAdjustedExn =
|
|
CGF.EmitNounwindRuntimeCall(getGetExceptionPtrFn(CGF.CGM), Exn);
|
|
|
|
// Cast that to the appropriate type.
|
|
Address adjustedExn(CGF.Builder.CreateBitCast(rawAdjustedExn, PtrTy),
|
|
caughtExnAlignment);
|
|
|
|
// The copy expression is defined in terms of an OpaqueValueExpr.
|
|
// Find it and map it to the adjusted expression.
|
|
CodeGenFunction::OpaqueValueMapping
|
|
opaque(CGF, OpaqueValueExpr::findInCopyConstruct(copyExpr),
|
|
CGF.MakeAddrLValue(adjustedExn, CatchParam.getType()));
|
|
|
|
// Call the copy ctor in a terminate scope.
|
|
CGF.EHStack.pushTerminate();
|
|
|
|
// Perform the copy construction.
|
|
CGF.EmitAggExpr(copyExpr,
|
|
AggValueSlot::forAddr(ParamAddr, Qualifiers(),
|
|
AggValueSlot::IsNotDestructed,
|
|
AggValueSlot::DoesNotNeedGCBarriers,
|
|
AggValueSlot::IsNotAliased,
|
|
AggValueSlot::DoesNotOverlap));
|
|
|
|
// Leave the terminate scope.
|
|
CGF.EHStack.popTerminate();
|
|
|
|
// Undo the opaque value mapping.
|
|
opaque.pop();
|
|
|
|
// Finally we can call __cxa_begin_catch.
|
|
CallBeginCatch(CGF, Exn, true);
|
|
}
|
|
|
|
/// Begins a catch statement by initializing the catch variable and
|
|
/// calling __cxa_begin_catch.
|
|
void ItaniumCXXABI::emitBeginCatch(CodeGenFunction &CGF,
|
|
const CXXCatchStmt *S) {
|
|
// We have to be very careful with the ordering of cleanups here:
|
|
// C++ [except.throw]p4:
|
|
// The destruction [of the exception temporary] occurs
|
|
// immediately after the destruction of the object declared in
|
|
// the exception-declaration in the handler.
|
|
//
|
|
// So the precise ordering is:
|
|
// 1. Construct catch variable.
|
|
// 2. __cxa_begin_catch
|
|
// 3. Enter __cxa_end_catch cleanup
|
|
// 4. Enter dtor cleanup
|
|
//
|
|
// We do this by using a slightly abnormal initialization process.
|
|
// Delegation sequence:
|
|
// - ExitCXXTryStmt opens a RunCleanupsScope
|
|
// - EmitAutoVarAlloca creates the variable and debug info
|
|
// - InitCatchParam initializes the variable from the exception
|
|
// - CallBeginCatch calls __cxa_begin_catch
|
|
// - CallBeginCatch enters the __cxa_end_catch cleanup
|
|
// - EmitAutoVarCleanups enters the variable destructor cleanup
|
|
// - EmitCXXTryStmt emits the code for the catch body
|
|
// - EmitCXXTryStmt close the RunCleanupsScope
|
|
|
|
VarDecl *CatchParam = S->getExceptionDecl();
|
|
if (!CatchParam) {
|
|
llvm::Value *Exn = CGF.getExceptionFromSlot();
|
|
CallBeginCatch(CGF, Exn, true);
|
|
return;
|
|
}
|
|
|
|
// Emit the local.
|
|
CodeGenFunction::AutoVarEmission var = CGF.EmitAutoVarAlloca(*CatchParam);
|
|
InitCatchParam(CGF, *CatchParam, var.getObjectAddress(CGF), S->getBeginLoc());
|
|
CGF.EmitAutoVarCleanups(var);
|
|
}
|
|
|
|
/// Get or define the following function:
|
|
/// void @__clang_call_terminate(i8* %exn) nounwind noreturn
|
|
/// This code is used only in C++.
|
|
static llvm::FunctionCallee getClangCallTerminateFn(CodeGenModule &CGM) {
|
|
llvm::FunctionType *fnTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, CGM.Int8PtrTy, /*isVarArg=*/false);
|
|
llvm::FunctionCallee fnRef = CGM.CreateRuntimeFunction(
|
|
fnTy, "__clang_call_terminate", llvm::AttributeList(), /*Local=*/true);
|
|
llvm::Function *fn =
|
|
cast<llvm::Function>(fnRef.getCallee()->stripPointerCasts());
|
|
if (fn->empty()) {
|
|
fn->setDoesNotThrow();
|
|
fn->setDoesNotReturn();
|
|
|
|
// What we really want is to massively penalize inlining without
|
|
// forbidding it completely. The difference between that and
|
|
// 'noinline' is negligible.
|
|
fn->addFnAttr(llvm::Attribute::NoInline);
|
|
|
|
// Allow this function to be shared across translation units, but
|
|
// we don't want it to turn into an exported symbol.
|
|
fn->setLinkage(llvm::Function::LinkOnceODRLinkage);
|
|
fn->setVisibility(llvm::Function::HiddenVisibility);
|
|
if (CGM.supportsCOMDAT())
|
|
fn->setComdat(CGM.getModule().getOrInsertComdat(fn->getName()));
|
|
|
|
// Set up the function.
|
|
llvm::BasicBlock *entry =
|
|
llvm::BasicBlock::Create(CGM.getLLVMContext(), "", fn);
|
|
CGBuilderTy builder(CGM, entry);
|
|
|
|
// Pull the exception pointer out of the parameter list.
|
|
llvm::Value *exn = &*fn->arg_begin();
|
|
|
|
// Call __cxa_begin_catch(exn).
|
|
llvm::CallInst *catchCall = builder.CreateCall(getBeginCatchFn(CGM), exn);
|
|
catchCall->setDoesNotThrow();
|
|
catchCall->setCallingConv(CGM.getRuntimeCC());
|
|
|
|
// Call std::terminate().
|
|
llvm::CallInst *termCall = builder.CreateCall(CGM.getTerminateFn());
|
|
termCall->setDoesNotThrow();
|
|
termCall->setDoesNotReturn();
|
|
termCall->setCallingConv(CGM.getRuntimeCC());
|
|
|
|
// std::terminate cannot return.
|
|
builder.CreateUnreachable();
|
|
}
|
|
return fnRef;
|
|
}
|
|
|
|
llvm::CallInst *
|
|
ItaniumCXXABI::emitTerminateForUnexpectedException(CodeGenFunction &CGF,
|
|
llvm::Value *Exn) {
|
|
// In C++, we want to call __cxa_begin_catch() before terminating.
|
|
if (Exn) {
|
|
assert(CGF.CGM.getLangOpts().CPlusPlus);
|
|
return CGF.EmitNounwindRuntimeCall(getClangCallTerminateFn(CGF.CGM), Exn);
|
|
}
|
|
return CGF.EmitNounwindRuntimeCall(CGF.CGM.getTerminateFn());
|
|
}
|
|
|
|
std::pair<llvm::Value *, const CXXRecordDecl *>
|
|
ItaniumCXXABI::LoadVTablePtr(CodeGenFunction &CGF, Address This,
|
|
const CXXRecordDecl *RD) {
|
|
return {CGF.GetVTablePtr(This, CGM.Int8PtrTy, RD), RD};
|
|
}
|
|
|
|
void WebAssemblyCXXABI::emitBeginCatch(CodeGenFunction &CGF,
|
|
const CXXCatchStmt *C) {
|
|
if (CGF.getTarget().hasFeature("exception-handling"))
|
|
CGF.EHStack.pushCleanup<CatchRetScope>(
|
|
NormalCleanup, cast<llvm::CatchPadInst>(CGF.CurrentFuncletPad));
|
|
ItaniumCXXABI::emitBeginCatch(CGF, C);
|
|
}
|
|
|
|
/// Register a global destructor as best as we know how.
|
|
void XLCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
|
|
llvm::FunctionCallee dtor,
|
|
llvm::Constant *addr) {
|
|
if (D.getTLSKind() != VarDecl::TLS_None)
|
|
llvm::report_fatal_error("thread local storage not yet implemented on AIX");
|
|
|
|
// Create __dtor function for the var decl.
|
|
llvm::Function *dtorStub = CGF.createAtExitStub(D, dtor, addr);
|
|
|
|
// Register above __dtor with atexit().
|
|
CGF.registerGlobalDtorWithAtExit(dtorStub);
|
|
|
|
// Emit __finalize function to unregister __dtor and (as appropriate) call
|
|
// __dtor.
|
|
emitCXXStermFinalizer(D, dtorStub, addr);
|
|
}
|
|
|
|
void XLCXXABI::emitCXXStermFinalizer(const VarDecl &D, llvm::Function *dtorStub,
|
|
llvm::Constant *addr) {
|
|
llvm::FunctionType *FTy = llvm::FunctionType::get(CGM.VoidTy, false);
|
|
SmallString<256> FnName;
|
|
{
|
|
llvm::raw_svector_ostream Out(FnName);
|
|
getMangleContext().mangleDynamicStermFinalizer(&D, Out);
|
|
}
|
|
|
|
// Create the finalization action associated with a variable.
|
|
const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
|
|
llvm::Function *StermFinalizer = CGM.CreateGlobalInitOrCleanUpFunction(
|
|
FTy, FnName.str(), FI, D.getLocation());
|
|
|
|
CodeGenFunction CGF(CGM);
|
|
|
|
CGF.StartFunction(GlobalDecl(), CGM.getContext().VoidTy, StermFinalizer, FI,
|
|
FunctionArgList(), D.getLocation(),
|
|
D.getInit()->getExprLoc());
|
|
|
|
// The unatexit subroutine unregisters __dtor functions that were previously
|
|
// registered by the atexit subroutine. If the referenced function is found,
|
|
// the unatexit returns a value of 0, meaning that the cleanup is still
|
|
// pending (and we should call the __dtor function).
|
|
llvm::Value *V = CGF.unregisterGlobalDtorWithUnAtExit(dtorStub);
|
|
|
|
llvm::Value *NeedsDestruct = CGF.Builder.CreateIsNull(V, "needs_destruct");
|
|
|
|
llvm::BasicBlock *DestructCallBlock = CGF.createBasicBlock("destruct.call");
|
|
llvm::BasicBlock *EndBlock = CGF.createBasicBlock("destruct.end");
|
|
|
|
// Check if unatexit returns a value of 0. If it does, jump to
|
|
// DestructCallBlock, otherwise jump to EndBlock directly.
|
|
CGF.Builder.CreateCondBr(NeedsDestruct, DestructCallBlock, EndBlock);
|
|
|
|
CGF.EmitBlock(DestructCallBlock);
|
|
|
|
// Emit the call to dtorStub.
|
|
llvm::CallInst *CI = CGF.Builder.CreateCall(dtorStub);
|
|
|
|
// Make sure the call and the callee agree on calling convention.
|
|
CI->setCallingConv(dtorStub->getCallingConv());
|
|
|
|
CGF.EmitBlock(EndBlock);
|
|
|
|
CGF.FinishFunction();
|
|
|
|
assert(!D.getAttr<InitPriorityAttr>() &&
|
|
"Prioritized sinit and sterm functions are not yet supported.");
|
|
|
|
if (isTemplateInstantiation(D.getTemplateSpecializationKind()) ||
|
|
getContext().GetGVALinkageForVariable(&D) == GVA_DiscardableODR)
|
|
// According to C++ [basic.start.init]p2, class template static data
|
|
// members (i.e., implicitly or explicitly instantiated specializations)
|
|
// have unordered initialization. As a consequence, we can put them into
|
|
// their own llvm.global_dtors entry.
|
|
CGM.AddCXXStermFinalizerToGlobalDtor(StermFinalizer, 65535);
|
|
else
|
|
CGM.AddCXXStermFinalizerEntry(StermFinalizer);
|
|
}
|