| //===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code dealing with C++ code generation. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // We might split this into multiple files if it gets too unwieldy |
| |
| #include "CodeGenFunction.h" |
| #include "CodeGenModule.h" |
| #include "Mangle.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/RecordLayout.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/AST/StmtCXX.h" |
| #include "llvm/ADT/StringExtras.h" |
| using namespace clang; |
| using namespace CodeGen; |
| |
| |
| |
| llvm::Value *CodeGenFunction::LoadCXXThis() { |
| assert(isa<CXXMethodDecl>(CurFuncDecl) && |
| "Must be in a C++ member function decl to load 'this'"); |
| assert(cast<CXXMethodDecl>(CurFuncDecl)->isInstance() && |
| "Must be in a C++ member function decl to load 'this'"); |
| |
| // FIXME: What if we're inside a block? |
| // ans: See how CodeGenFunction::LoadObjCSelf() uses |
| // CodeGenFunction::BlockForwardSelf() for how to do this. |
| return Builder.CreateLoad(LocalDeclMap[CXXThisDecl], "this"); |
| } |
| |
| void CodeGenModule::EmitCXXConstructors(const CXXConstructorDecl *D) { |
| EmitGlobal(GlobalDecl(D, Ctor_Complete)); |
| EmitGlobal(GlobalDecl(D, Ctor_Base)); |
| } |
| |
| void CodeGenModule::EmitCXXConstructor(const CXXConstructorDecl *D, |
| CXXCtorType Type) { |
| |
| llvm::Function *Fn = GetAddrOfCXXConstructor(D, Type); |
| |
| CodeGenFunction(*this).GenerateCode(GlobalDecl(D, Type), Fn); |
| |
| SetFunctionDefinitionAttributes(D, Fn); |
| SetLLVMFunctionAttributesForDefinition(D, Fn); |
| } |
| |
| llvm::Function * |
| CodeGenModule::GetAddrOfCXXConstructor(const CXXConstructorDecl *D, |
| CXXCtorType Type) { |
| const FunctionProtoType *FPT = D->getType()->getAs<FunctionProtoType>(); |
| const llvm::FunctionType *FTy = |
| getTypes().GetFunctionType(getTypes().getFunctionInfo(D, Type), |
| FPT->isVariadic()); |
| |
| const char *Name = getMangledCXXCtorName(D, Type); |
| return cast<llvm::Function>( |
| GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type))); |
| } |
| |
| const char *CodeGenModule::getMangledCXXCtorName(const CXXConstructorDecl *D, |
| CXXCtorType Type) { |
| llvm::SmallString<256> Name; |
| getMangleContext().mangleCXXCtor(D, Type, Name); |
| |
| Name += '\0'; |
| return UniqueMangledName(Name.begin(), Name.end()); |
| } |
| |
| void CodeGenModule::EmitCXXDestructors(const CXXDestructorDecl *D) { |
| if (D->isVirtual()) |
| EmitGlobal(GlobalDecl(D, Dtor_Deleting)); |
| EmitGlobal(GlobalDecl(D, Dtor_Complete)); |
| EmitGlobal(GlobalDecl(D, Dtor_Base)); |
| } |
| |
| void CodeGenModule::EmitCXXDestructor(const CXXDestructorDecl *D, |
| CXXDtorType Type) { |
| llvm::Function *Fn = GetAddrOfCXXDestructor(D, Type); |
| |
| CodeGenFunction(*this).GenerateCode(GlobalDecl(D, Type), Fn); |
| |
| SetFunctionDefinitionAttributes(D, Fn); |
| SetLLVMFunctionAttributesForDefinition(D, Fn); |
| } |
| |
| llvm::Function * |
| CodeGenModule::GetAddrOfCXXDestructor(const CXXDestructorDecl *D, |
| CXXDtorType Type) { |
| const llvm::FunctionType *FTy = |
| getTypes().GetFunctionType(getTypes().getFunctionInfo(D, Type), false); |
| |
| const char *Name = getMangledCXXDtorName(D, Type); |
| return cast<llvm::Function>( |
| GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type))); |
| } |
| |
| const char *CodeGenModule::getMangledCXXDtorName(const CXXDestructorDecl *D, |
| CXXDtorType Type) { |
| llvm::SmallString<256> Name; |
| getMangleContext().mangleCXXDtor(D, Type, Name); |
| |
| Name += '\0'; |
| return UniqueMangledName(Name.begin(), Name.end()); |
| } |
| |
| llvm::Constant * |
| CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD, |
| bool Extern, |
| const ThunkAdjustment &ThisAdjustment) { |
| return GenerateCovariantThunk(Fn, GD, Extern, |
| CovariantThunkAdjustment(ThisAdjustment, |
| ThunkAdjustment())); |
| } |
| |
| llvm::Value * |
| CodeGenFunction::DynamicTypeAdjust(llvm::Value *V, |
| const ThunkAdjustment &Adjustment) { |
| const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext); |
| |
| const llvm::Type *OrigTy = V->getType(); |
| if (Adjustment.NonVirtual) { |
| // Do the non-virtual adjustment |
| V = Builder.CreateBitCast(V, Int8PtrTy); |
| V = Builder.CreateConstInBoundsGEP1_64(V, Adjustment.NonVirtual); |
| V = Builder.CreateBitCast(V, OrigTy); |
| } |
| |
| if (!Adjustment.Virtual) |
| return V; |
| |
| assert(Adjustment.Virtual % (LLVMPointerWidth / 8) == 0 && |
| "vtable entry unaligned"); |
| |
| // Do the virtual this adjustment |
| const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType()); |
| const llvm::Type *PtrDiffPtrTy = PtrDiffTy->getPointerTo(); |
| |
| llvm::Value *ThisVal = Builder.CreateBitCast(V, Int8PtrTy); |
| V = Builder.CreateBitCast(V, PtrDiffPtrTy->getPointerTo()); |
| V = Builder.CreateLoad(V, "vtable"); |
| |
| llvm::Value *VTablePtr = V; |
| uint64_t VirtualAdjustment = Adjustment.Virtual / (LLVMPointerWidth / 8); |
| V = Builder.CreateConstInBoundsGEP1_64(VTablePtr, VirtualAdjustment); |
| V = Builder.CreateLoad(V); |
| V = Builder.CreateGEP(ThisVal, V); |
| |
| return Builder.CreateBitCast(V, OrigTy); |
| } |
| |
| llvm::Constant * |
| CodeGenFunction::GenerateCovariantThunk(llvm::Function *Fn, |
| GlobalDecl GD, bool Extern, |
| const CovariantThunkAdjustment &Adjustment) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
| QualType ResultType = FPT->getResultType(); |
| |
| FunctionArgList Args; |
| ImplicitParamDecl *ThisDecl = |
| ImplicitParamDecl::Create(getContext(), 0, SourceLocation(), 0, |
| MD->getThisType(getContext())); |
| Args.push_back(std::make_pair(ThisDecl, ThisDecl->getType())); |
| for (FunctionDecl::param_const_iterator i = MD->param_begin(), |
| e = MD->param_end(); |
| i != e; ++i) { |
| ParmVarDecl *D = *i; |
| Args.push_back(std::make_pair(D, D->getType())); |
| } |
| IdentifierInfo *II |
| = &CGM.getContext().Idents.get("__thunk_named_foo_"); |
| FunctionDecl *FD = FunctionDecl::Create(getContext(), |
| getContext().getTranslationUnitDecl(), |
| SourceLocation(), II, ResultType, 0, |
| Extern |
| ? FunctionDecl::Extern |
| : FunctionDecl::Static, |
| false, true); |
| StartFunction(FD, ResultType, Fn, Args, SourceLocation()); |
| |
| // generate body |
| const llvm::Type *Ty = |
| CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), |
| FPT->isVariadic()); |
| llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty); |
| |
| CallArgList CallArgs; |
| |
| bool ShouldAdjustReturnPointer = true; |
| QualType ArgType = MD->getThisType(getContext()); |
| llvm::Value *Arg = Builder.CreateLoad(LocalDeclMap[ThisDecl], "this"); |
| if (!Adjustment.ThisAdjustment.isEmpty()) { |
| // Do the this adjustment. |
| const llvm::Type *OrigTy = Callee->getType(); |
| Arg = DynamicTypeAdjust(Arg, Adjustment.ThisAdjustment); |
| |
| if (!Adjustment.ReturnAdjustment.isEmpty()) { |
| const CovariantThunkAdjustment &ReturnAdjustment = |
| CovariantThunkAdjustment(ThunkAdjustment(), |
| Adjustment.ReturnAdjustment); |
| |
| Callee = CGM.BuildCovariantThunk(GD, Extern, ReturnAdjustment); |
| |
| Callee = Builder.CreateBitCast(Callee, OrigTy); |
| ShouldAdjustReturnPointer = false; |
| } |
| } |
| |
| CallArgs.push_back(std::make_pair(RValue::get(Arg), ArgType)); |
| |
| for (FunctionDecl::param_const_iterator i = MD->param_begin(), |
| e = MD->param_end(); |
| i != e; ++i) { |
| ParmVarDecl *D = *i; |
| QualType ArgType = D->getType(); |
| |
| // llvm::Value *Arg = CGF.GetAddrOfLocalVar(Dst); |
| Expr *Arg = new (getContext()) DeclRefExpr(D, ArgType.getNonReferenceType(), |
| SourceLocation()); |
| CallArgs.push_back(std::make_pair(EmitCallArg(Arg, ArgType), ArgType)); |
| } |
| |
| RValue RV = EmitCall(CGM.getTypes().getFunctionInfo(ResultType, CallArgs, |
| FPT->getCallConv(), |
| FPT->getNoReturnAttr()), |
| Callee, ReturnValueSlot(), CallArgs, MD); |
| if (ShouldAdjustReturnPointer && !Adjustment.ReturnAdjustment.isEmpty()) { |
| bool CanBeZero = !(ResultType->isReferenceType() |
| // FIXME: attr nonnull can't be zero either |
| /* || ResultType->hasAttr<NonNullAttr>() */ ); |
| // Do the return result adjustment. |
| if (CanBeZero) { |
| llvm::BasicBlock *NonZeroBlock = createBasicBlock(); |
| llvm::BasicBlock *ZeroBlock = createBasicBlock(); |
| llvm::BasicBlock *ContBlock = createBasicBlock(); |
| |
| const llvm::Type *Ty = RV.getScalarVal()->getType(); |
| llvm::Value *Zero = llvm::Constant::getNullValue(Ty); |
| Builder.CreateCondBr(Builder.CreateICmpNE(RV.getScalarVal(), Zero), |
| NonZeroBlock, ZeroBlock); |
| EmitBlock(NonZeroBlock); |
| llvm::Value *NZ = |
| DynamicTypeAdjust(RV.getScalarVal(), Adjustment.ReturnAdjustment); |
| EmitBranch(ContBlock); |
| EmitBlock(ZeroBlock); |
| llvm::Value *Z = RV.getScalarVal(); |
| EmitBlock(ContBlock); |
| llvm::PHINode *RVOrZero = Builder.CreatePHI(Ty); |
| RVOrZero->reserveOperandSpace(2); |
| RVOrZero->addIncoming(NZ, NonZeroBlock); |
| RVOrZero->addIncoming(Z, ZeroBlock); |
| RV = RValue::get(RVOrZero); |
| } else |
| RV = RValue::get(DynamicTypeAdjust(RV.getScalarVal(), |
| Adjustment.ReturnAdjustment)); |
| } |
| |
| if (!ResultType->isVoidType()) |
| EmitReturnOfRValue(RV, ResultType); |
| |
| FinishFunction(); |
| return Fn; |
| } |
| |
| llvm::Constant * |
| CodeGenModule::GetAddrOfThunk(GlobalDecl GD, |
| const ThunkAdjustment &ThisAdjustment) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| |
| // Compute mangled name |
| llvm::SmallString<256> OutName; |
| if (const CXXDestructorDecl* DD = dyn_cast<CXXDestructorDecl>(MD)) |
| getMangleContext().mangleCXXDtorThunk(DD, GD.getDtorType(), ThisAdjustment, |
| OutName); |
| else |
| getMangleContext().mangleThunk(MD, ThisAdjustment, OutName); |
| OutName += '\0'; |
| const char* Name = UniqueMangledName(OutName.begin(), OutName.end()); |
| |
| // Get function for mangled name |
| const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD); |
| return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl()); |
| } |
| |
| llvm::Constant * |
| CodeGenModule::GetAddrOfCovariantThunk(GlobalDecl GD, |
| const CovariantThunkAdjustment &Adjustment) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| |
| // Compute mangled name |
| llvm::SmallString<256> OutName; |
| getMangleContext().mangleCovariantThunk(MD, Adjustment, OutName); |
| OutName += '\0'; |
| const char* Name = UniqueMangledName(OutName.begin(), OutName.end()); |
| |
| // Get function for mangled name |
| const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD); |
| return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl()); |
| } |
| |
| void CodeGenModule::BuildThunksForVirtual(GlobalDecl GD) { |
| CGVtableInfo::AdjustmentVectorTy *AdjPtr = getVtableInfo().getAdjustments(GD); |
| if (!AdjPtr) |
| return; |
| CGVtableInfo::AdjustmentVectorTy &Adj = *AdjPtr; |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| for (unsigned i = 0; i < Adj.size(); i++) { |
| GlobalDecl OGD = Adj[i].first; |
| const CXXMethodDecl *OMD = cast<CXXMethodDecl>(OGD.getDecl()); |
| QualType nc_oret = OMD->getType()->getAs<FunctionType>()->getResultType(); |
| CanQualType oret = getContext().getCanonicalType(nc_oret); |
| QualType nc_ret = MD->getType()->getAs<FunctionType>()->getResultType(); |
| CanQualType ret = getContext().getCanonicalType(nc_ret); |
| ThunkAdjustment ReturnAdjustment; |
| if (oret != ret) { |
| QualType qD = nc_ret->getPointeeType(); |
| QualType qB = nc_oret->getPointeeType(); |
| CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl()); |
| CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl()); |
| ReturnAdjustment = ComputeThunkAdjustment(D, B); |
| } |
| ThunkAdjustment ThisAdjustment = Adj[i].second; |
| bool Extern = !cast<CXXRecordDecl>(OMD->getDeclContext())->isInAnonymousNamespace(); |
| if (!ReturnAdjustment.isEmpty() || !ThisAdjustment.isEmpty()) { |
| CovariantThunkAdjustment CoAdj(ThisAdjustment, ReturnAdjustment); |
| llvm::Constant *FnConst; |
| if (!ReturnAdjustment.isEmpty()) |
| FnConst = GetAddrOfCovariantThunk(GD, CoAdj); |
| else |
| FnConst = GetAddrOfThunk(GD, ThisAdjustment); |
| if (!isa<llvm::Function>(FnConst)) { |
| llvm::Constant *SubExpr = |
| cast<llvm::ConstantExpr>(FnConst)->getOperand(0); |
| llvm::Function *OldFn = cast<llvm::Function>(SubExpr); |
| std::string Name = OldFn->getNameStr(); |
| GlobalDeclMap.erase(UniqueMangledName(Name.data(), |
| Name.data() + Name.size() + 1)); |
| llvm::Constant *NewFnConst; |
| if (!ReturnAdjustment.isEmpty()) |
| NewFnConst = GetAddrOfCovariantThunk(GD, CoAdj); |
| else |
| NewFnConst = GetAddrOfThunk(GD, ThisAdjustment); |
| llvm::Function *NewFn = cast<llvm::Function>(NewFnConst); |
| NewFn->takeName(OldFn); |
| llvm::Constant *NewPtrForOldDecl = |
| llvm::ConstantExpr::getBitCast(NewFn, OldFn->getType()); |
| OldFn->replaceAllUsesWith(NewPtrForOldDecl); |
| OldFn->eraseFromParent(); |
| FnConst = NewFn; |
| } |
| llvm::Function *Fn = cast<llvm::Function>(FnConst); |
| if (Fn->isDeclaration()) { |
| llvm::GlobalVariable::LinkageTypes linktype; |
| linktype = llvm::GlobalValue::WeakAnyLinkage; |
| if (!Extern) |
| linktype = llvm::GlobalValue::InternalLinkage; |
| Fn->setLinkage(linktype); |
| if (!Features.Exceptions && !Features.ObjCNonFragileABI) |
| Fn->addFnAttr(llvm::Attribute::NoUnwind); |
| Fn->setAlignment(2); |
| CodeGenFunction(*this).GenerateCovariantThunk(Fn, GD, Extern, CoAdj); |
| } |
| } |
| } |
| } |
| |
| llvm::Constant * |
| CodeGenModule::BuildThunk(GlobalDecl GD, bool Extern, |
| const ThunkAdjustment &ThisAdjustment) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| llvm::SmallString<256> OutName; |
| if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(MD)) { |
| getMangleContext().mangleCXXDtorThunk(D, GD.getDtorType(), ThisAdjustment, |
| OutName); |
| } else |
| getMangleContext().mangleThunk(MD, ThisAdjustment, OutName); |
| |
| llvm::GlobalVariable::LinkageTypes linktype; |
| linktype = llvm::GlobalValue::WeakAnyLinkage; |
| if (!Extern) |
| linktype = llvm::GlobalValue::InternalLinkage; |
| llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0); |
| const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
| const llvm::FunctionType *FTy = |
| getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), |
| FPT->isVariadic()); |
| |
| llvm::Function *Fn = llvm::Function::Create(FTy, linktype, OutName.str(), |
| &getModule()); |
| CodeGenFunction(*this).GenerateThunk(Fn, GD, Extern, ThisAdjustment); |
| llvm::Constant *m = llvm::ConstantExpr::getBitCast(Fn, Ptr8Ty); |
| return m; |
| } |
| |
| llvm::Constant * |
| CodeGenModule::BuildCovariantThunk(const GlobalDecl &GD, bool Extern, |
| const CovariantThunkAdjustment &Adjustment) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| llvm::SmallString<256> OutName; |
| getMangleContext().mangleCovariantThunk(MD, Adjustment, OutName); |
| llvm::GlobalVariable::LinkageTypes linktype; |
| linktype = llvm::GlobalValue::WeakAnyLinkage; |
| if (!Extern) |
| linktype = llvm::GlobalValue::InternalLinkage; |
| llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0); |
| const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
| const llvm::FunctionType *FTy = |
| getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), |
| FPT->isVariadic()); |
| |
| llvm::Function *Fn = llvm::Function::Create(FTy, linktype, OutName.str(), |
| &getModule()); |
| CodeGenFunction(*this).GenerateCovariantThunk(Fn, MD, Extern, Adjustment); |
| llvm::Constant *m = llvm::ConstantExpr::getBitCast(Fn, Ptr8Ty); |
| return m; |
| } |
| |
| static llvm::Value *BuildVirtualCall(CodeGenFunction &CGF, uint64_t VtableIndex, |
| llvm::Value *This, const llvm::Type *Ty) { |
| Ty = Ty->getPointerTo()->getPointerTo()->getPointerTo(); |
| |
| llvm::Value *Vtable = CGF.Builder.CreateBitCast(This, Ty); |
| Vtable = CGF.Builder.CreateLoad(Vtable); |
| |
| llvm::Value *VFuncPtr = |
| CGF.Builder.CreateConstInBoundsGEP1_64(Vtable, VtableIndex, "vfn"); |
| return CGF.Builder.CreateLoad(VFuncPtr); |
| } |
| |
| llvm::Value * |
| CodeGenFunction::BuildVirtualCall(const CXXMethodDecl *MD, llvm::Value *This, |
| const llvm::Type *Ty) { |
| MD = MD->getCanonicalDecl(); |
| uint64_t VtableIndex = CGM.getVtableInfo().getMethodVtableIndex(MD); |
| |
| return ::BuildVirtualCall(*this, VtableIndex, This, Ty); |
| } |
| |
| llvm::Value * |
| CodeGenFunction::BuildVirtualCall(const CXXDestructorDecl *DD, CXXDtorType Type, |
| llvm::Value *&This, const llvm::Type *Ty) { |
| DD = cast<CXXDestructorDecl>(DD->getCanonicalDecl()); |
| uint64_t VtableIndex = |
| CGM.getVtableInfo().getMethodVtableIndex(GlobalDecl(DD, Type)); |
| |
| return ::BuildVirtualCall(*this, VtableIndex, This, Ty); |
| } |