//===--- 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 "llvm/ADT/StringExtras.h" using namespace clang; using namespace CodeGen; void CodeGenFunction::EmitCXXGlobalDtorRegistration(const CXXDestructorDecl *Dtor, llvm::Constant *DeclPtr) { // FIXME: This is ABI dependent and we use the Itanium ABI. const llvm::Type *Int8PtrTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); std::vector Params; Params.push_back(Int8PtrTy); // Get the destructor function type const llvm::Type *DtorFnTy = llvm::FunctionType::get(llvm::Type::VoidTy, Params, false); DtorFnTy = llvm::PointerType::getUnqual(DtorFnTy); Params.clear(); Params.push_back(DtorFnTy); Params.push_back(Int8PtrTy); Params.push_back(Int8PtrTy); // Get the __cxa_atexit function type // extern "C" int __cxa_atexit ( void (*f)(void *), void *p, void *d ); const llvm::FunctionType *AtExitFnTy = llvm::FunctionType::get(ConvertType(getContext().IntTy), Params, false); llvm::Constant *AtExitFn = CGM.CreateRuntimeFunction(AtExitFnTy, "__cxa_atexit"); llvm::Constant *Handle = CGM.CreateRuntimeVariable(Int8PtrTy, "__dso_handle"); llvm::Constant *DtorFn = CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete); llvm::Value *Args[3] = { llvm::ConstantExpr::getBitCast(DtorFn, DtorFnTy), llvm::ConstantExpr::getBitCast(DeclPtr, Int8PtrTy), llvm::ConstantExpr::getBitCast(Handle, Int8PtrTy) }; Builder.CreateCall(AtExitFn, &Args[0], llvm::array_endof(Args)); } void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr) { assert(D.hasGlobalStorage() && "VarDecl must have global storage!"); const Expr *Init = D.getInit(); QualType T = D.getType(); if (T->isReferenceType()) { ErrorUnsupported(Init, "Global variable that binds to a reference"); } else if (!hasAggregateLLVMType(T)) { llvm::Value *V = EmitScalarExpr(Init); EmitStoreOfScalar(V, DeclPtr, T.isVolatileQualified(), T); } else if (T->isAnyComplexType()) { EmitComplexExprIntoAddr(Init, DeclPtr, T.isVolatileQualified()); } else { EmitAggExpr(Init, DeclPtr, T.isVolatileQualified()); if (const RecordType *RT = T->getAs()) { CXXRecordDecl *RD = cast(RT->getDecl()); if (!RD->hasTrivialDestructor()) EmitCXXGlobalDtorRegistration(RD->getDestructor(getContext()), DeclPtr); } } } void CodeGenModule::EmitCXXGlobalInitFunc() { if (CXXGlobalInits.empty()) return; const llvm::FunctionType *FTy = llvm::FunctionType::get(llvm::Type::VoidTy, false); // Create our global initialization function. // FIXME: Should this be tweakable by targets? llvm::Function *Fn = llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, "__cxx_global_initialization", &TheModule); CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, &CXXGlobalInits[0], CXXGlobalInits.size()); AddGlobalCtor(Fn); } void CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn, const VarDecl **Decls, unsigned NumDecls) { StartFunction(0, getContext().VoidTy, Fn, FunctionArgList(), SourceLocation()); for (unsigned i = 0; i != NumDecls; ++i) { const VarDecl *D = Decls[i]; llvm::Constant *DeclPtr = CGM.GetAddrOfGlobalVar(D); EmitCXXGlobalVarDeclInit(*D, DeclPtr); } FinishFunction(); } void CodeGenFunction::EmitStaticCXXBlockVarDeclInit(const VarDecl &D, llvm::GlobalVariable *GV) { // FIXME: This should use __cxa_guard_{acquire,release}? assert(!getContext().getLangOptions().ThreadsafeStatics && "thread safe statics are currently not supported!"); llvm::SmallString<256> GuardVName; llvm::raw_svector_ostream GuardVOut(GuardVName); mangleGuardVariable(&D, getContext(), GuardVOut); // Create the guard variable. llvm::GlobalValue *GuardV = new llvm::GlobalVariable(CGM.getModule(), llvm::Type::Int64Ty, false, GV->getLinkage(), llvm::Constant::getNullValue(llvm::Type::Int64Ty), GuardVName.c_str()); // Load the first byte of the guard variable. const llvm::Type *PtrTy = llvm::PointerType::get(llvm::Type::Int8Ty, 0); llvm::Value *V = Builder.CreateLoad(Builder.CreateBitCast(GuardV, PtrTy), "tmp"); // Compare it against 0. llvm::Value *nullValue = llvm::Constant::getNullValue(llvm::Type::Int8Ty); llvm::Value *ICmp = Builder.CreateICmpEQ(V, nullValue , "tobool"); llvm::BasicBlock *InitBlock = createBasicBlock("init"); llvm::BasicBlock *EndBlock = createBasicBlock("init.end"); // If the guard variable is 0, jump to the initializer code. Builder.CreateCondBr(ICmp, InitBlock, EndBlock); EmitBlock(InitBlock); EmitCXXGlobalVarDeclInit(D, GV); Builder.CreateStore(llvm::ConstantInt::get(llvm::Type::Int8Ty, 1), Builder.CreateBitCast(GuardV, PtrTy)); EmitBlock(EndBlock); } RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD, llvm::Value *Callee, llvm::Value *This, CallExpr::const_arg_iterator ArgBeg, CallExpr::const_arg_iterator ArgEnd) { assert(MD->isInstance() && "Trying to emit a member call expr on a static method!"); const FunctionProtoType *FPT = MD->getType()->getAsFunctionProtoType(); CallArgList Args; // Push the this ptr. Args.push_back(std::make_pair(RValue::get(This), MD->getThisType(getContext()))); // And the rest of the call args EmitCallArgs(Args, FPT, ArgBeg, ArgEnd); QualType ResultType = MD->getType()->getAsFunctionType()->getResultType(); return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args), Callee, Args, MD); } RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE) { const MemberExpr *ME = cast(CE->getCallee()); const CXXMethodDecl *MD = cast(ME->getMemberDecl()); const FunctionProtoType *FPT = MD->getType()->getAsFunctionProtoType(); if (MD->isVirtual()) { ErrorUnsupported(CE, "virtual dispatch"); } const llvm::Type *Ty = CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), FPT->isVariadic()); llvm::Constant *Callee = CGM.GetAddrOfFunction(GlobalDecl(MD), Ty); llvm::Value *This; if (ME->isArrow()) This = EmitScalarExpr(ME->getBase()); else { LValue BaseLV = EmitLValue(ME->getBase()); This = BaseLV.getAddress(); } return EmitCXXMemberCall(MD, Callee, This, CE->arg_begin(), CE->arg_end()); } RValue CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E, const CXXMethodDecl *MD) { assert(MD->isInstance() && "Trying to emit a member call expr on a static method!"); const FunctionProtoType *FPT = MD->getType()->getAsFunctionProtoType(); const llvm::Type *Ty = CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), FPT->isVariadic()); llvm::Constant *Callee = CGM.GetAddrOfFunction(GlobalDecl(MD), Ty); llvm::Value *This = EmitLValue(E->getArg(0)).getAddress(); return EmitCXXMemberCall(MD, Callee, This, E->arg_begin() + 1, E->arg_end()); } llvm::Value *CodeGenFunction::LoadCXXThis() { assert(isa(CurFuncDecl) && "Must be in a C++ member function decl to load 'this'"); assert(cast(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"); } static bool GetNestedPaths(llvm::SmallVectorImpl &NestedBasePaths, const CXXRecordDecl *ClassDecl, const CXXRecordDecl *BaseClassDecl) { for (CXXRecordDecl::base_class_const_iterator i = ClassDecl->bases_begin(), e = ClassDecl->bases_end(); i != e; ++i) { if (i->isVirtual()) continue; const CXXRecordDecl *Base = cast(i->getType()->getAs()->getDecl()); if (Base == BaseClassDecl) { NestedBasePaths.push_back(BaseClassDecl); return true; } } // BaseClassDecl not an immediate base of ClassDecl. for (CXXRecordDecl::base_class_const_iterator i = ClassDecl->bases_begin(), e = ClassDecl->bases_end(); i != e; ++i) { if (i->isVirtual()) continue; const CXXRecordDecl *Base = cast(i->getType()->getAs()->getDecl()); if (GetNestedPaths(NestedBasePaths, Base, BaseClassDecl)) { NestedBasePaths.push_back(Base); return true; } } return false; } llvm::Value *CodeGenFunction::AddressCXXOfBaseClass(llvm::Value *BaseValue, const CXXRecordDecl *ClassDecl, const CXXRecordDecl *BaseClassDecl) { if (ClassDecl == BaseClassDecl) return BaseValue; llvm::Type *I8Ptr = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); llvm::SmallVector NestedBasePaths; GetNestedPaths(NestedBasePaths, ClassDecl, BaseClassDecl); assert(NestedBasePaths.size() > 0 && "AddressCXXOfBaseClass - inheritence path failed"); NestedBasePaths.push_back(ClassDecl); uint64_t Offset = 0; // Accessing a member of the base class. Must add delata to // the load of 'this'. for (unsigned i = NestedBasePaths.size()-1; i > 0; i--) { const CXXRecordDecl *DerivedClass = NestedBasePaths[i]; const CXXRecordDecl *BaseClass = NestedBasePaths[i-1]; const ASTRecordLayout &Layout = getContext().getASTRecordLayout(DerivedClass); Offset += Layout.getBaseClassOffset(BaseClass) / 8; } llvm::Value *OffsetVal = llvm::ConstantInt::get( CGM.getTypes().ConvertType(CGM.getContext().LongTy), Offset); BaseValue = Builder.CreateBitCast(BaseValue, I8Ptr); BaseValue = Builder.CreateGEP(BaseValue, OffsetVal, "add.ptr"); QualType BTy = getContext().getCanonicalType( getContext().getTypeDeclType(const_cast(BaseClassDecl))); const llvm::Type *BasePtr = ConvertType(BTy); BasePtr = llvm::PointerType::getUnqual(BasePtr); BaseValue = Builder.CreateBitCast(BaseValue, BasePtr); return BaseValue; } void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type, llvm::Value *This, CallExpr::const_arg_iterator ArgBeg, CallExpr::const_arg_iterator ArgEnd) { llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, Type); EmitCXXMemberCall(D, Callee, This, ArgBeg, ArgEnd); } void CodeGenFunction::EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type, llvm::Value *This) { llvm::Value *Callee = CGM.GetAddrOfCXXDestructor(D, Type); EmitCXXMemberCall(D, Callee, This, 0, 0); } void CodeGenFunction::EmitCXXConstructExpr(llvm::Value *Dest, const CXXConstructExpr *E) { assert(Dest && "Must have a destination!"); const CXXRecordDecl *RD = cast(E->getType()->getAs()->getDecl()); if (RD->hasTrivialConstructor()) return; // Code gen optimization to eliminate copy constructor and return // its first argument instead. if (E->isElidable()) { CXXConstructExpr::const_arg_iterator i = E->arg_begin(); EmitAggExpr((*i), Dest, false); return; } // Call the constructor. EmitCXXConstructorCall(E->getConstructor(), Ctor_Complete, Dest, E->arg_begin(), E->arg_end()); } llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { if (E->isArray()) { ErrorUnsupported(E, "new[] expression"); return llvm::UndefValue::get(ConvertType(E->getType())); } QualType AllocType = E->getAllocatedType(); FunctionDecl *NewFD = E->getOperatorNew(); const FunctionProtoType *NewFTy = NewFD->getType()->getAsFunctionProtoType(); CallArgList NewArgs; // The allocation size is the first argument. QualType SizeTy = getContext().getSizeType(); llvm::Value *AllocSize = llvm::ConstantInt::get(ConvertType(SizeTy), getContext().getTypeSize(AllocType) / 8); NewArgs.push_back(std::make_pair(RValue::get(AllocSize), SizeTy)); // Emit the rest of the arguments. // FIXME: Ideally, this should just use EmitCallArgs. CXXNewExpr::const_arg_iterator NewArg = E->placement_arg_begin(); // First, use the types from the function type. // We start at 1 here because the first argument (the allocation size) // has already been emitted. for (unsigned i = 1, e = NewFTy->getNumArgs(); i != e; ++i, ++NewArg) { QualType ArgType = NewFTy->getArgType(i); assert(getContext().getCanonicalType(ArgType.getNonReferenceType()). getTypePtr() == getContext().getCanonicalType(NewArg->getType()).getTypePtr() && "type mismatch in call argument!"); NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType), ArgType)); } // Either we've emitted all the call args, or we have a call to a // variadic function. assert((NewArg == E->placement_arg_end() || NewFTy->isVariadic()) && "Extra arguments in non-variadic function!"); // If we still have any arguments, emit them using the type of the argument. for (CXXNewExpr::const_arg_iterator NewArgEnd = E->placement_arg_end(); NewArg != NewArgEnd; ++NewArg) { QualType ArgType = NewArg->getType(); NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType), ArgType)); } // Emit the call to new. RValue RV = EmitCall(CGM.getTypes().getFunctionInfo(NewFTy->getResultType(), NewArgs), CGM.GetAddrOfFunction(GlobalDecl(NewFD)), NewArgs, NewFD); // If an allocation function is declared with an empty exception specification // it returns null to indicate failure to allocate storage. [expr.new]p13. // (We don't need to check for null when there's no new initializer and // we're allocating a POD type). bool NullCheckResult = NewFTy->hasEmptyExceptionSpec() && !(AllocType->isPODType() && !E->hasInitializer()); llvm::BasicBlock *NewNull = 0; llvm::BasicBlock *NewNotNull = 0; llvm::BasicBlock *NewEnd = 0; llvm::Value *NewPtr = RV.getScalarVal(); if (NullCheckResult) { NewNull = createBasicBlock("new.null"); NewNotNull = createBasicBlock("new.notnull"); NewEnd = createBasicBlock("new.end"); llvm::Value *IsNull = Builder.CreateICmpEQ(NewPtr, llvm::Constant::getNullValue(NewPtr->getType()), "isnull"); Builder.CreateCondBr(IsNull, NewNull, NewNotNull); EmitBlock(NewNotNull); } NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType())); if (AllocType->isPODType()) { if (E->getNumConstructorArgs() > 0) { assert(E->getNumConstructorArgs() == 1 && "Can only have one argument to initializer of POD type."); const Expr *Init = E->getConstructorArg(0); if (!hasAggregateLLVMType(AllocType)) Builder.CreateStore(EmitScalarExpr(Init), NewPtr); else if (AllocType->isAnyComplexType()) EmitComplexExprIntoAddr(Init, NewPtr, AllocType.isVolatileQualified()); else EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified()); } } else { // Call the constructor. CXXConstructorDecl *Ctor = E->getConstructor(); EmitCXXConstructorCall(Ctor, Ctor_Complete, NewPtr, E->constructor_arg_begin(), E->constructor_arg_end()); } if (NullCheckResult) { Builder.CreateBr(NewEnd); EmitBlock(NewNull); Builder.CreateBr(NewEnd); EmitBlock(NewEnd); llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType()); PHI->reserveOperandSpace(2); PHI->addIncoming(NewPtr, NewNotNull); PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()), NewNull); NewPtr = PHI; } return NewPtr; } static bool canGenerateCXXstructor(const CXXRecordDecl *RD, ASTContext &Context) { // The class has base classes - we don't support that right now. if (RD->getNumBases() > 0) return false; for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); I != E; ++I) { // We don't support ctors for fields that aren't POD. if (!I->getType()->isPODType()) return false; } return true; } void CodeGenModule::EmitCXXConstructors(const CXXConstructorDecl *D) { if (!canGenerateCXXstructor(D->getParent(), getContext())) { ErrorUnsupported(D, "C++ constructor", true); return; } 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(D, Fn); SetFunctionDefinitionAttributes(D, Fn); SetLLVMFunctionAttributesForDefinition(D, Fn); } llvm::Function * CodeGenModule::GetAddrOfCXXConstructor(const CXXConstructorDecl *D, CXXCtorType Type) { const llvm::FunctionType *FTy = getTypes().GetFunctionType(getTypes().getFunctionInfo(D), false); const char *Name = getMangledCXXCtorName(D, Type); return cast( GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type))); } const char *CodeGenModule::getMangledCXXCtorName(const CXXConstructorDecl *D, CXXCtorType Type) { llvm::SmallString<256> Name; llvm::raw_svector_ostream Out(Name); mangleCXXCtor(D, Type, Context, Out); Name += '\0'; return UniqueMangledName(Name.begin(), Name.end()); } void CodeGenModule::EmitCXXDestructors(const CXXDestructorDecl *D) { if (!canGenerateCXXstructor(D->getParent(), getContext())) { ErrorUnsupported(D, "C++ destructor", true); return; } EmitCXXDestructor(D, Dtor_Complete); EmitCXXDestructor(D, Dtor_Base); } void CodeGenModule::EmitCXXDestructor(const CXXDestructorDecl *D, CXXDtorType Type) { llvm::Function *Fn = GetAddrOfCXXDestructor(D, Type); CodeGenFunction(*this).GenerateCode(D, 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), false); const char *Name = getMangledCXXDtorName(D, Type); return cast( GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type))); } const char *CodeGenModule::getMangledCXXDtorName(const CXXDestructorDecl *D, CXXDtorType Type) { llvm::SmallString<256> Name; llvm::raw_svector_ostream Out(Name); mangleCXXDtor(D, Type, Context, Out); Name += '\0'; return UniqueMangledName(Name.begin(), Name.end()); } llvm::Constant *CodeGenFunction::GenerateRtti(const CXXRecordDecl *RD) { llvm::Type *Ptr8Ty; Ptr8Ty = llvm::PointerType::get(llvm::Type::Int8Ty, 0); llvm::Constant *Rtti = llvm::Constant::getNullValue(Ptr8Ty); if (!getContext().getLangOptions().Rtti) return Rtti; llvm::SmallString<256> OutName; llvm::raw_svector_ostream Out(OutName); QualType ClassTy; ClassTy = getContext().getTagDeclType(RD); mangleCXXRtti(ClassTy, getContext(), Out); const char *Name = OutName.c_str(); llvm::GlobalVariable::LinkageTypes linktype; linktype = llvm::GlobalValue::WeakAnyLinkage; std::vector info; // assert (0 && "FIXME: implement rtti descriptor"); // FIXME: descriptor info.push_back(llvm::Constant::getNullValue(Ptr8Ty)); // assert (0 && "FIXME: implement rtti ts"); // FIXME: TS info.push_back(llvm::Constant::getNullValue(Ptr8Ty)); llvm::Constant *C; llvm::ArrayType *type = llvm::ArrayType::get(Ptr8Ty, info.size()); C = llvm::ConstantArray::get(type, info); Rtti = new llvm::GlobalVariable(CGM.getModule(), type, true, linktype, C, Name); Rtti = llvm::ConstantExpr::getBitCast(Rtti, Ptr8Ty); return Rtti; } void CodeGenFunction::GenerateVtableForBase(const CXXRecordDecl *RD, const CXXRecordDecl *Class, llvm::Constant *rtti, std::vector &methods, bool isPrimary, bool ForVirtualBase, llvm::SmallSet &IndirectPrimary) { typedef CXXRecordDecl::method_iterator meth_iter; llvm::Type *Ptr8Ty; Ptr8Ty = llvm::PointerType::get(llvm::Type::Int8Ty, 0); llvm::Constant *m = llvm::Constant::getNullValue(Ptr8Ty); if (RD && !RD->isDynamicClass()) return; const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Class); if (isPrimary) { // The virtual base offsets come first... for (CXXRecordDecl::reverse_base_class_const_iterator i = Class->bases_rbegin(), e = Class->bases_rend(); i != e; ++i) { if (!i->isVirtual()) continue; const CXXRecordDecl *Base = cast(i->getType()->getAs()->getDecl()); int64_t BaseOffset = Layout.getBaseClassOffset(Base) / 8; llvm::Constant *m; m = llvm::ConstantInt::get(llvm::Type::Int64Ty, BaseOffset); m = llvm::ConstantExpr::getIntToPtr(m, Ptr8Ty); methods.push_back(m); } } // then comes the the vcall offsets for all our functions... if (isPrimary && ForVirtualBase) for (meth_iter mi = Class->method_begin(), me = Class->method_end(); mi != me; ++mi) { if (mi->isVirtual()) { // FIXME: vcall: offset for virtual base for this function m = llvm::Constant::getNullValue(Ptr8Ty); methods.push_back(m); } } bool TopPrimary = true; // Primary tables are composed from the chain of primaries. if (isPrimary) { const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); if (PrimaryBase) { if (PrimaryBaseWasVirtual) IndirectPrimary.insert(PrimaryBase); TopPrimary = false; GenerateVtableForBase(0, PrimaryBase, rtti, methods, true, PrimaryBaseWasVirtual, IndirectPrimary); } } // then come the vcall offsets for all our virtual bases. if (!isPrimary && RD && ForVirtualBase) for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; ++mi) { if (mi->isVirtual()) { // FIXME: vcall: offset for virtual base for this function m = llvm::Constant::getNullValue(Ptr8Ty); methods.push_back(m); } } if (TopPrimary) { if (RD) { int64_t BaseOffset = -(Layout.getBaseClassOffset(RD) / 8); m = llvm::ConstantInt::get(llvm::Type::Int64Ty, BaseOffset); m = llvm::ConstantExpr::getIntToPtr(m, Ptr8Ty); } methods.push_back(m); methods.push_back(rtti); } if (!isPrimary) { if (!RD) return; for (meth_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; ++mi) { if (mi->isVirtual()) { m = CGM.GetAddrOfFunction(GlobalDecl(*mi)); m = llvm::ConstantExpr::getBitCast(m, Ptr8Ty); methods.push_back(m); } } return; } // And add the virtuals for the class to the primary vtable. for (meth_iter mi = Class->method_begin(), me = Class->method_end(); mi != me; ++mi) { if (mi->isVirtual()) { m = CGM.GetAddrOfFunction(GlobalDecl(*mi)); m = llvm::ConstantExpr::getBitCast(m, Ptr8Ty); methods.push_back(m); } } } llvm::Value *CodeGenFunction::GenerateVtable(const CXXRecordDecl *RD) { llvm::SmallString<256> OutName; llvm::raw_svector_ostream Out(OutName); QualType ClassTy; ClassTy = getContext().getTagDeclType(RD); mangleCXXVtable(ClassTy, getContext(), Out); const char *Name = OutName.c_str(); llvm::GlobalVariable::LinkageTypes linktype; linktype = llvm::GlobalValue::WeakAnyLinkage; std::vector methods; typedef CXXRecordDecl::method_iterator meth_iter; llvm::Type *Ptr8Ty; Ptr8Ty = llvm::PointerType::get(llvm::Type::Int8Ty, 0); int64_t Offset = 0; llvm::Constant *rtti = GenerateRtti(RD); Offset += LLVMPointerWidth; Offset += LLVMPointerWidth; const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD); const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); llvm::SmallSet IndirectPrimary; // The primary base comes first. GenerateVtableForBase(PrimaryBase, RD, rtti, methods, true, PrimaryBaseWasVirtual, IndirectPrimary); for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), e = RD->bases_end(); i != e; ++i) { if (i->isVirtual()) continue; const CXXRecordDecl *Base = cast(i->getType()->getAs()->getDecl()); if (PrimaryBase != Base) { GenerateVtableForBase(Base, RD, rtti, methods, false, false, IndirectPrimary); } } // FIXME: finish layout for virtual bases // FIXME: audit indirect virtual bases for (CXXRecordDecl::base_class_const_iterator i = RD->vbases_begin(), e = RD->vbases_end(); i != e; ++i) { const CXXRecordDecl *Base = cast(i->getType()->getAs()->getDecl()); if (!IndirectPrimary.count(Base)) GenerateVtableForBase(Base, RD, rtti, methods, false, true, IndirectPrimary); } llvm::Constant *C; llvm::ArrayType *type = llvm::ArrayType::get(Ptr8Ty, methods.size()); C = llvm::ConstantArray::get(type, methods); llvm::Value *vtable = new llvm::GlobalVariable(CGM.getModule(), type, true, linktype, C, Name); vtable = Builder.CreateBitCast(vtable, Ptr8Ty); vtable = Builder.CreateGEP(vtable, llvm::ConstantInt::get(llvm::Type::Int64Ty, Offset/8)); return vtable; } /// EmitClassMemberwiseCopy - This routine generates code to copy a class /// object from SrcValue to DestValue. Copying can be either a bitwise copy /// of via a copy constructor call. void CodeGenFunction::EmitClassMemberwiseCopy( llvm::Value *Dest, llvm::Value *Src, const CXXRecordDecl *ClassDecl, const CXXRecordDecl *BaseClassDecl, QualType Ty) { if (ClassDecl) { Dest = AddressCXXOfBaseClass(Dest, ClassDecl, BaseClassDecl); Src = AddressCXXOfBaseClass(Src, ClassDecl, BaseClassDecl) ; } if (BaseClassDecl->hasTrivialCopyConstructor()) { EmitAggregateCopy(Dest, Src, Ty); return; } if (CXXConstructorDecl *BaseCopyCtor = BaseClassDecl->getCopyConstructor(getContext(), 0)) { llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(BaseCopyCtor, Ctor_Complete); CallArgList CallArgs; // Push the this (Dest) ptr. CallArgs.push_back(std::make_pair(RValue::get(Dest), BaseCopyCtor->getThisType(getContext()))); // Push the Src ptr. CallArgs.push_back(std::make_pair(RValue::get(Src), BaseCopyCtor->getParamDecl(0)->getType())); QualType ResultType = BaseCopyCtor->getType()->getAsFunctionType()->getResultType(); EmitCall(CGM.getTypes().getFunctionInfo(ResultType, CallArgs), Callee, CallArgs, BaseCopyCtor); } } /// SynthesizeDefaultConstructor - synthesize a default constructor void CodeGenFunction::SynthesizeDefaultConstructor(const CXXConstructorDecl *CD, const FunctionDecl *FD, llvm::Function *Fn, const FunctionArgList &Args) { StartFunction(FD, FD->getResultType(), Fn, Args, SourceLocation()); EmitCtorPrologue(CD); FinishFunction(); } /// SynthesizeCXXCopyConstructor - This routine implicitly defines body of a copy /// constructor, in accordance with section 12.8 (p7 and p8) of C++03 /// The implicitly-defined copy constructor for class X performs a memberwise /// copy of its subobjects. The order of copying is the same as the order /// of initialization of bases and members in a user-defined constructor /// Each subobject is copied in the manner appropriate to its type: /// if the subobject is of class type, the copy constructor for the class is /// used; /// if the subobject is an array, each element is copied, in the manner /// appropriate to the element type; /// if the subobject is of scalar type, the built-in assignment operator is /// used. /// Virtual base class subobjects shall be copied only once by the /// implicitly-defined copy constructor void CodeGenFunction::SynthesizeCXXCopyConstructor(const CXXConstructorDecl *CD, const FunctionDecl *FD, llvm::Function *Fn, const FunctionArgList &Args) { const CXXRecordDecl *ClassDecl = cast(CD->getDeclContext()); assert(!ClassDecl->hasUserDeclaredCopyConstructor() && "SynthesizeCXXCopyConstructor - copy constructor has definition already"); StartFunction(FD, FD->getResultType(), Fn, Args, SourceLocation()); FunctionArgList::const_iterator i = Args.begin(); const VarDecl *ThisArg = i->first; llvm::Value *ThisObj = GetAddrOfLocalVar(ThisArg); llvm::Value *LoadOfThis = Builder.CreateLoad(ThisObj, "this"); const VarDecl *SrcArg = (i+1)->first; llvm::Value *SrcObj = GetAddrOfLocalVar(SrcArg); llvm::Value *LoadOfSrc = Builder.CreateLoad(SrcObj); for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(); Base != ClassDecl->bases_end(); ++Base) { // FIXME. copy constrution of virtual base NYI if (Base->isVirtual()) continue; CXXRecordDecl *BaseClassDecl = cast(Base->getType()->getAs()->getDecl()); EmitClassMemberwiseCopy(LoadOfThis, LoadOfSrc, ClassDecl, BaseClassDecl, Base->getType()); } for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(), FieldEnd = ClassDecl->field_end(); Field != FieldEnd; ++Field) { QualType FieldType = getContext().getCanonicalType((*Field)->getType()); // FIXME. How about copying arrays! assert(!getContext().getAsArrayType(FieldType) && "FIXME. Copying arrays NYI"); if (const RecordType *FieldClassType = FieldType->getAs()) { CXXRecordDecl *FieldClassDecl = cast(FieldClassType->getDecl()); LValue LHS = EmitLValueForField(LoadOfThis, *Field, false, 0); LValue RHS = EmitLValueForField(LoadOfSrc, *Field, false, 0); EmitClassMemberwiseCopy(LHS.getAddress(), RHS.getAddress(), 0 /*ClassDecl*/, FieldClassDecl, FieldType); continue; } // Do a built-in assignment of scalar data members. LValue LHS = EmitLValueForField(LoadOfThis, *Field, false, 0); LValue RHS = EmitLValueForField(LoadOfSrc, *Field, false, 0); RValue RVRHS = EmitLoadOfLValue(RHS, FieldType); EmitStoreThroughLValue(RVRHS, LHS, FieldType); } FinishFunction(); } /// SynthesizeCXXCopyAssignment - Implicitly define copy assignment operator. /// Before the implicitly-declared copy assignment operator for a class is /// implicitly defined, all implicitly- declared copy assignment operators for /// its direct base classes and its nonstatic data members shall have been /// implicitly defined. [12.8-p12] /// The implicitly-defined copy assignment operator for class X performs /// memberwise assignment of its subob- jects. The direct base classes of X are /// assigned first, in the order of their declaration in /// the base-specifier-list, and then the immediate nonstatic data members of X /// are assigned, in the order in which they were declared in the class /// definition.Each subobject is assigned in the manner appropriate to its type: /// — if the subobject is of class type, the copy assignment operator for the /// class is used (as if by explicit qual- ification; that is, ignoring any /// possible virtual overriding functions in more derived classes); /// — if the subobject is an array, each element is assigned, in the manner /// appropriate to the element type; /// — if the subobject is of scalar type, the built-in assignment operator is /// used. void CodeGenFunction::SynthesizeCXXCopyAssignment(const CXXMethodDecl *CD, const FunctionDecl *FD, llvm::Function *Fn, const FunctionArgList &Args) { StartFunction(FD, FD->getResultType(), Fn, Args, SourceLocation()); FinishFunction(); } /// EmitCtorPrologue - This routine generates necessary code to initialize /// base classes and non-static data members belonging to this constructor. void CodeGenFunction::EmitCtorPrologue(const CXXConstructorDecl *CD) { const CXXRecordDecl *ClassDecl = cast(CD->getDeclContext()); // FIXME: Add vbase initialization llvm::Value *LoadOfThis = 0; for (CXXConstructorDecl::init_const_iterator B = CD->init_begin(), E = CD->init_end(); B != E; ++B) { CXXBaseOrMemberInitializer *Member = (*B); if (Member->isBaseInitializer()) { LoadOfThis = LoadCXXThis(); Type *BaseType = Member->getBaseClass(); CXXRecordDecl *BaseClassDecl = cast(BaseType->getAs()->getDecl()); llvm::Value *V = AddressCXXOfBaseClass(LoadOfThis, ClassDecl, BaseClassDecl); EmitCXXConstructorCall(Member->getConstructor(), Ctor_Complete, V, Member->const_arg_begin(), Member->const_arg_end()); } else { // non-static data member initilaizers. FieldDecl *Field = Member->getMember(); QualType FieldType = getContext().getCanonicalType((Field)->getType()); assert(!getContext().getAsArrayType(FieldType) && "FIXME. Field arrays initialization unsupported"); LoadOfThis = LoadCXXThis(); LValue LHS = EmitLValueForField(LoadOfThis, Field, false, 0); if (FieldType->getAs()) { if (!Field->isAnonymousStructOrUnion()) { assert(Member->getConstructor() && "EmitCtorPrologue - no constructor to initialize member"); EmitCXXConstructorCall(Member->getConstructor(), Ctor_Complete, LHS.getAddress(), Member->const_arg_begin(), Member->const_arg_end()); continue; } else { // Initializing an anonymous union data member. FieldDecl *anonMember = Member->getAnonUnionMember(); LHS = EmitLValueForField(LHS.getAddress(), anonMember, false, 0); FieldType = anonMember->getType(); } } assert(Member->getNumArgs() == 1 && "Initializer count must be 1 only"); Expr *RhsExpr = *Member->arg_begin(); llvm::Value *RHS = EmitScalarExpr(RhsExpr, true); EmitStoreThroughLValue(RValue::get(RHS), LHS, FieldType); } } // Initialize the vtable pointer if (ClassDecl->isDynamicClass()) { if (!LoadOfThis) LoadOfThis = LoadCXXThis(); llvm::Value *VtableField; llvm::Type *Ptr8Ty, *PtrPtr8Ty; Ptr8Ty = llvm::PointerType::get(llvm::Type::Int8Ty, 0); PtrPtr8Ty = llvm::PointerType::get(Ptr8Ty, 0); VtableField = Builder.CreateBitCast(LoadOfThis, PtrPtr8Ty); llvm::Value *vtable = GenerateVtable(ClassDecl); Builder.CreateStore(vtable, VtableField); } } /// EmitDtorEpilogue - Emit all code that comes at the end of class's /// destructor. This is to call destructors on members and base classes /// in reverse order of their construction. void CodeGenFunction::EmitDtorEpilogue(const CXXDestructorDecl *DD) { const CXXRecordDecl *ClassDecl = cast(DD->getDeclContext()); assert(!ClassDecl->isPolymorphic() && "FIXME. polymorphic destruction not supported"); (void)ClassDecl; // prevent warning. for (CXXDestructorDecl::destr_const_iterator *B = DD->destr_begin(), *E = DD->destr_end(); B != E; ++B) { uintptr_t BaseOrMember = (*B); if (DD->isMemberToDestroy(BaseOrMember)) { FieldDecl *FD = DD->getMemberToDestroy(BaseOrMember); QualType FieldType = getContext().getCanonicalType((FD)->getType()); assert(!getContext().getAsArrayType(FieldType) && "FIXME. Field arrays destruction unsupported"); const RecordType *RT = FieldType->getAs(); CXXRecordDecl *FieldClassDecl = cast(RT->getDecl()); if (FieldClassDecl->hasTrivialDestructor()) continue; llvm::Value *LoadOfThis = LoadCXXThis(); LValue LHS = EmitLValueForField(LoadOfThis, FD, false, 0); EmitCXXDestructorCall(FieldClassDecl->getDestructor(getContext()), Dtor_Complete, LHS.getAddress()); } else { const RecordType *RT = DD->getAnyBaseClassToDestroy(BaseOrMember)->getAs(); CXXRecordDecl *BaseClassDecl = cast(RT->getDecl()); if (BaseClassDecl->hasTrivialDestructor()) continue; llvm::Value *V = AddressCXXOfBaseClass(LoadCXXThis(), ClassDecl,BaseClassDecl); EmitCXXDestructorCall(BaseClassDecl->getDestructor(getContext()), Dtor_Complete, V); } } }