| //===--- 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 to emit Decl nodes as LLVM code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CGDebugInfo.h" |
| #include "CodeGenFunction.h" |
| #include "CodeGenModule.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "llvm/GlobalVariable.h" |
| #include "llvm/Intrinsics.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Type.h" |
| using namespace clang; |
| using namespace CodeGen; |
| |
| |
| void CodeGenFunction::EmitDecl(const Decl &D) { |
| switch (D.getKind()) { |
| default: assert(0 && "Unknown decl kind!"); |
| case Decl::ParmVar: |
| assert(0 && "Parmdecls should not be in declstmts!"); |
| case Decl::Function: // void X(); |
| case Decl::Record: // struct/union/class X; |
| case Decl::Enum: // enum X; |
| case Decl::EnumConstant: // enum ? { X = ? } |
| case Decl::CXXRecord: // struct/union/class X; [C++] |
| // None of these decls require codegen support. |
| return; |
| |
| case Decl::Var: { |
| const VarDecl &VD = cast<VarDecl>(D); |
| assert(VD.isBlockVarDecl() && |
| "Should not see file-scope variables inside a function!"); |
| return EmitBlockVarDecl(VD); |
| } |
| |
| case Decl::Typedef: { // typedef int X; |
| const TypedefDecl &TD = cast<TypedefDecl>(D); |
| QualType Ty = TD.getUnderlyingType(); |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVLASize(Ty); |
| } |
| } |
| } |
| |
| /// EmitBlockVarDecl - This method handles emission of any variable declaration |
| /// inside a function, including static vars etc. |
| void CodeGenFunction::EmitBlockVarDecl(const VarDecl &D) { |
| if (D.hasAttr<AsmLabelAttr>()) |
| CGM.ErrorUnsupported(&D, "__asm__"); |
| |
| switch (D.getStorageClass()) { |
| case VarDecl::None: |
| case VarDecl::Auto: |
| case VarDecl::Register: |
| return EmitLocalBlockVarDecl(D); |
| case VarDecl::Static: |
| return EmitStaticBlockVarDecl(D); |
| case VarDecl::Extern: |
| case VarDecl::PrivateExtern: |
| // Don't emit it now, allow it to be emitted lazily on its first use. |
| return; |
| } |
| |
| assert(0 && "Unknown storage class"); |
| } |
| |
| llvm::GlobalVariable * |
| CodeGenFunction::CreateStaticBlockVarDecl(const VarDecl &D, |
| const char *Separator, |
| llvm::GlobalValue::LinkageTypes |
| Linkage) { |
| QualType Ty = D.getType(); |
| assert(Ty->isConstantSizeType() && "VLAs can't be static"); |
| |
| std::string Name; |
| if (getContext().getLangOptions().CPlusPlus) { |
| Name = CGM.getMangledName(&D); |
| } else { |
| std::string ContextName; |
| if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurFuncDecl)) |
| ContextName = CGM.getMangledName(FD); |
| else if (isa<ObjCMethodDecl>(CurFuncDecl)) |
| ContextName = std::string(CurFn->getNameStart(), |
| CurFn->getNameStart() + CurFn->getNameLen()); |
| else |
| assert(0 && "Unknown context for block var decl"); |
| |
| Name = ContextName + Separator + D.getNameAsString(); |
| } |
| |
| const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty); |
| return new llvm::GlobalVariable(LTy, Ty.isConstant(getContext()), Linkage, |
| llvm::Constant::getNullValue(LTy), Name, |
| &CGM.getModule(), D.isThreadSpecified(), |
| Ty.getAddressSpace()); |
| } |
| |
| void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) { |
| |
| llvm::Value *&DMEntry = LocalDeclMap[&D]; |
| assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); |
| |
| llvm::GlobalVariable *GV = |
| CreateStaticBlockVarDecl(D, ".", llvm::GlobalValue::InternalLinkage); |
| |
| // Store into LocalDeclMap before generating initializer to handle |
| // circular references. |
| DMEntry = GV; |
| |
| // Make sure to evaluate VLA bounds now so that we have them for later. |
| if (D.getType()->isVariablyModifiedType()) |
| EmitVLASize(D.getType()); |
| |
| if (D.getInit()) { |
| llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(), D.getType(), this); |
| |
| // If constant emission failed, then this should be a C++ static |
| // initializer. |
| if (!Init) { |
| if (!getContext().getLangOptions().CPlusPlus) |
| CGM.ErrorUnsupported(D.getInit(), "constant l-value expression"); |
| else |
| GenerateStaticCXXBlockVarDeclInit(D, GV); |
| } else { |
| // The initializer may differ in type from the global. Rewrite |
| // the global to match the initializer. (We have to do this |
| // because some types, like unions, can't be completely represented |
| // in the LLVM type system.) |
| if (GV->getType() != Init->getType()) { |
| llvm::GlobalVariable *OldGV = GV; |
| |
| GV = new llvm::GlobalVariable(Init->getType(), OldGV->isConstant(), |
| OldGV->getLinkage(), Init, "", |
| &CGM.getModule(), D.isThreadSpecified(), |
| D.getType().getAddressSpace()); |
| |
| // Steal the name of the old global |
| GV->takeName(OldGV); |
| |
| // Replace all uses of the old global with the new global |
| llvm::Constant *NewPtrForOldDecl = |
| llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); |
| OldGV->replaceAllUsesWith(NewPtrForOldDecl); |
| |
| // Erase the old global, since it is no longer used. |
| OldGV->eraseFromParent(); |
| } |
| |
| GV->setInitializer(Init); |
| } |
| } |
| |
| // FIXME: Merge attribute handling. |
| if (const AnnotateAttr *AA = D.getAttr<AnnotateAttr>()) { |
| SourceManager &SM = CGM.getContext().getSourceManager(); |
| llvm::Constant *Ann = |
| CGM.EmitAnnotateAttr(GV, AA, |
| SM.getInstantiationLineNumber(D.getLocation())); |
| CGM.AddAnnotation(Ann); |
| } |
| |
| if (const SectionAttr *SA = D.getAttr<SectionAttr>()) |
| GV->setSection(SA->getName()); |
| |
| if (D.hasAttr<UsedAttr>()) |
| CGM.AddUsedGlobal(GV); |
| |
| // We may have to cast the constant because of the initializer |
| // mismatch above. |
| // |
| // FIXME: It is really dangerous to store this in the map; if anyone |
| // RAUW's the GV uses of this constant will be invalid. |
| const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType()); |
| const llvm::Type *LPtrTy = |
| llvm::PointerType::get(LTy, D.getType().getAddressSpace()); |
| DMEntry = llvm::ConstantExpr::getBitCast(GV, LPtrTy); |
| |
| // Emit global variable debug descriptor for static vars. |
| CGDebugInfo *DI = getDebugInfo(); |
| if (DI) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D); |
| } |
| } |
| |
| /// BuildByRefType - This routine changes a __block variable declared as T x |
| /// into: |
| /// |
| /// struct { |
| /// void *__isa; |
| /// void *__forwarding; |
| /// int32_t __flags; |
| /// int32_t __size; |
| /// void *__copy_helper; |
| /// void *__destroy_helper; |
| /// T x; |
| /// } x |
| /// |
| /// Align is the alignment needed in bytes for x. |
| const llvm::Type *CodeGenFunction::BuildByRefType(QualType Ty, |
| uint64_t Align) { |
| const llvm::Type *LTy = ConvertType(Ty); |
| bool needsCopyDispose = BlockRequiresCopying(Ty); |
| std::vector<const llvm::Type *> Types(needsCopyDispose*2+5); |
| const llvm::PointerType *PtrToInt8Ty |
| = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); |
| Types[0] = PtrToInt8Ty; |
| Types[1] = PtrToInt8Ty; |
| Types[2] = llvm::Type::Int32Ty; |
| Types[3] = llvm::Type::Int32Ty; |
| if (needsCopyDispose) { |
| Types[4] = PtrToInt8Ty; |
| Types[5] = PtrToInt8Ty; |
| } |
| // FIXME: Align this on at least an Align boundary. |
| Types[needsCopyDispose*2 + 4] = LTy; |
| return llvm::StructType::get(Types, false); |
| } |
| |
| /// EmitLocalBlockVarDecl - Emit code and set up an entry in LocalDeclMap for a |
| /// variable declaration with auto, register, or no storage class specifier. |
| /// These turn into simple stack objects, or GlobalValues depending on target. |
| void CodeGenFunction::EmitLocalBlockVarDecl(const VarDecl &D) { |
| QualType Ty = D.getType(); |
| bool isByRef = D.hasAttr<BlocksAttr>(); |
| bool needsDispose = false; |
| |
| llvm::Value *DeclPtr; |
| if (Ty->isConstantSizeType()) { |
| if (!Target.useGlobalsForAutomaticVariables()) { |
| // A normal fixed sized variable becomes an alloca in the entry block. |
| const llvm::Type *LTy = ConvertTypeForMem(Ty); |
| if (isByRef) |
| LTy = BuildByRefType(Ty, getContext().getDeclAlignInBytes(&D)); |
| llvm::AllocaInst *Alloc = CreateTempAlloca(LTy); |
| Alloc->setName(D.getNameAsString().c_str()); |
| |
| if (isByRef) |
| Alloc->setAlignment(std::max(getContext().getDeclAlignInBytes(&D), |
| unsigned(Target.getPointerAlign(0) / 8))); |
| else |
| Alloc->setAlignment(getContext().getDeclAlignInBytes(&D)); |
| DeclPtr = Alloc; |
| } else { |
| // Targets that don't support recursion emit locals as globals. |
| const char *Class = |
| D.getStorageClass() == VarDecl::Register ? ".reg." : ".auto."; |
| DeclPtr = CreateStaticBlockVarDecl(D, Class, |
| llvm::GlobalValue |
| ::InternalLinkage); |
| } |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVLASize(Ty); |
| } else { |
| if (!DidCallStackSave) { |
| // Save the stack. |
| const llvm::Type *LTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); |
| llvm::Value *Stack = CreateTempAlloca(LTy, "saved_stack"); |
| |
| llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave); |
| llvm::Value *V = Builder.CreateCall(F); |
| |
| Builder.CreateStore(V, Stack); |
| |
| DidCallStackSave = true; |
| |
| { |
| // Push a cleanup block and restore the stack there. |
| CleanupScope scope(*this); |
| |
| V = Builder.CreateLoad(Stack, "tmp"); |
| llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stackrestore); |
| Builder.CreateCall(F, V); |
| } |
| } |
| |
| // Get the element type. |
| const llvm::Type *LElemTy = ConvertTypeForMem(Ty); |
| const llvm::Type *LElemPtrTy = |
| llvm::PointerType::get(LElemTy, D.getType().getAddressSpace()); |
| |
| llvm::Value *VLASize = EmitVLASize(Ty); |
| |
| // Downcast the VLA size expression |
| VLASize = Builder.CreateIntCast(VLASize, llvm::Type::Int32Ty, false, "tmp"); |
| |
| // Allocate memory for the array. |
| llvm::Value *VLA = Builder.CreateAlloca(llvm::Type::Int8Ty, VLASize, "vla"); |
| DeclPtr = Builder.CreateBitCast(VLA, LElemPtrTy, "tmp"); |
| } |
| |
| llvm::Value *&DMEntry = LocalDeclMap[&D]; |
| assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); |
| DMEntry = DeclPtr; |
| |
| // Emit debug info for local var declaration. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| DI->setLocation(D.getLocation()); |
| if (isByRef) { |
| llvm::Value *Loc; |
| bool needsCopyDispose = BlockRequiresCopying(Ty); |
| // FIXME: I think we need to indirect through the forwarding pointer first |
| Loc = Builder.CreateStructGEP(DeclPtr, needsCopyDispose*2+4, "x"); |
| DI->EmitDeclareOfAutoVariable(&D, Loc, Builder); |
| } else |
| DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder); |
| } |
| |
| // If this local has an initializer, emit it now. |
| if (const Expr *Init = D.getInit()) { |
| llvm::Value *Loc = DeclPtr; |
| if (isByRef) { |
| bool needsCopyDispose = BlockRequiresCopying(Ty); |
| Loc = Builder.CreateStructGEP(DeclPtr, needsCopyDispose*2+4, "x"); |
| } |
| if (!hasAggregateLLVMType(Init->getType())) { |
| llvm::Value *V = EmitScalarExpr(Init); |
| EmitStoreOfScalar(V, Loc, D.getType().isVolatileQualified()); |
| } else if (Init->getType()->isAnyComplexType()) { |
| EmitComplexExprIntoAddr(Init, Loc, D.getType().isVolatileQualified()); |
| } else { |
| EmitAggExpr(Init, Loc, D.getType().isVolatileQualified()); |
| } |
| } |
| if (isByRef) { |
| const llvm::PointerType *PtrToInt8Ty |
| = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); |
| |
| llvm::Value *isa_field = Builder.CreateStructGEP(DeclPtr, 0); |
| llvm::Value *forwarding_field = Builder.CreateStructGEP(DeclPtr, 1); |
| llvm::Value *flags_field = Builder.CreateStructGEP(DeclPtr, 2); |
| llvm::Value *size_field = Builder.CreateStructGEP(DeclPtr, 3); |
| llvm::Value *V; |
| int flag = 0; |
| int flags = 0; |
| |
| needsDispose = true; |
| |
| if (Ty->isBlockPointerType()) { |
| flag |= BLOCK_FIELD_IS_BLOCK; |
| flags |= BLOCK_HAS_COPY_DISPOSE; |
| } else if (BlockRequiresCopying(Ty)) { |
| flag |= BLOCK_FIELD_IS_OBJECT; |
| flags |= BLOCK_HAS_COPY_DISPOSE; |
| } |
| |
| // FIXME: Someone double check this. |
| if (Ty.isObjCGCWeak()) |
| flag |= BLOCK_FIELD_IS_WEAK; |
| |
| int isa = 0; |
| if (flag&BLOCK_FIELD_IS_WEAK) |
| isa = 1; |
| V = llvm::ConstantInt::get(llvm::Type::Int32Ty, isa); |
| V = Builder.CreateIntToPtr(V, PtrToInt8Ty, "isa"); |
| Builder.CreateStore(V, isa_field); |
| |
| V = Builder.CreateBitCast(DeclPtr, PtrToInt8Ty, "forwarding"); |
| Builder.CreateStore(V, forwarding_field); |
| |
| V = llvm::ConstantInt::get(llvm::Type::Int32Ty, flags); |
| Builder.CreateStore(V, flags_field); |
| |
| const llvm::Type *V1; |
| V1 = cast<llvm::PointerType>(DeclPtr->getType())->getElementType(); |
| V = llvm::ConstantInt::get(llvm::Type::Int32Ty, |
| (CGM.getTargetData().getTypeStoreSizeInBits(V1) |
| / 8)); |
| Builder.CreateStore(V, size_field); |
| |
| if (flags & BLOCK_HAS_COPY_DISPOSE) { |
| BlockHasCopyDispose = true; |
| llvm::Value *copy_helper = Builder.CreateStructGEP(DeclPtr, 4); |
| Builder.CreateStore(BuildbyrefCopyHelper(DeclPtr->getType(), flag), |
| copy_helper); |
| |
| llvm::Value *destroy_helper = Builder.CreateStructGEP(DeclPtr, 5); |
| Builder.CreateStore(BuildbyrefDestroyHelper(DeclPtr->getType(), flag), |
| destroy_helper); |
| } |
| } |
| |
| // Handle the cleanup attribute |
| if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) { |
| const FunctionDecl *FD = CA->getFunctionDecl(); |
| |
| llvm::Constant* F = CGM.GetAddrOfFunction(FD); |
| assert(F && "Could not find function!"); |
| |
| CleanupScope scope(*this); |
| |
| CallArgList Args; |
| Args.push_back(std::make_pair(RValue::get(DeclPtr), |
| getContext().getPointerType(D.getType()))); |
| |
| EmitCall(CGM.getTypes().getFunctionInfo(FD), F, Args); |
| } |
| |
| if (needsDispose && CGM.getLangOptions().getGCMode() != LangOptions::GCOnly) { |
| CleanupScope scope(*this); |
| llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding"); |
| V = Builder.CreateLoad(V, false); |
| BuildBlockRelease(V); |
| } |
| } |
| |
| /// Emit an alloca (or GlobalValue depending on target) |
| /// for the specified parameter and set up LocalDeclMap. |
| void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg) { |
| // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl? |
| assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) && |
| "Invalid argument to EmitParmDecl"); |
| QualType Ty = D.getType(); |
| |
| llvm::Value *DeclPtr; |
| if (!Ty->isConstantSizeType()) { |
| // Variable sized values always are passed by-reference. |
| DeclPtr = Arg; |
| } else { |
| // A fixed sized single-value variable becomes an alloca in the entry block. |
| const llvm::Type *LTy = ConvertTypeForMem(Ty); |
| if (LTy->isSingleValueType()) { |
| // TODO: Alignment |
| std::string Name = D.getNameAsString(); |
| Name += ".addr"; |
| DeclPtr = CreateTempAlloca(LTy); |
| DeclPtr->setName(Name.c_str()); |
| |
| // Store the initial value into the alloca. |
| EmitStoreOfScalar(Arg, DeclPtr, Ty.isVolatileQualified()); |
| } else { |
| // Otherwise, if this is an aggregate, just use the input pointer. |
| DeclPtr = Arg; |
| } |
| Arg->setName(D.getNameAsString()); |
| } |
| |
| llvm::Value *&DMEntry = LocalDeclMap[&D]; |
| assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); |
| DMEntry = DeclPtr; |
| |
| // Emit debug info for param declaration. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitDeclareOfArgVariable(&D, DeclPtr, Builder); |
| } |
| } |
| |