| //===--- 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/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) { |
| switch (D.getStorageClass()) { |
| case VarDecl::Static: |
| return EmitStaticBlockVarDecl(D); |
| case VarDecl::Extern: |
| // Don't emit it now, allow it to be emitted lazily on its first use. |
| return; |
| default: |
| assert((D.getStorageClass() == VarDecl::None || |
| D.getStorageClass() == VarDecl::Auto || |
| D.getStorageClass() == VarDecl::Register) && |
| "Unknown storage class"); |
| return EmitLocalBlockVarDecl(D); |
| } |
| } |
| |
| llvm::GlobalValue * |
| CodeGenFunction::GenerateStaticBlockVarDecl(const VarDecl &D, |
| bool NoInit, |
| const char *Separator) { |
| QualType Ty = D.getType(); |
| assert(Ty->isConstantSizeType() && "VLAs can't be static"); |
| |
| const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty); |
| llvm::Constant *Init = 0; |
| if ((D.getInit() == 0) || NoInit) { |
| Init = llvm::Constant::getNullValue(LTy); |
| } else { |
| if (D.getInit()->isConstantInitializer(getContext())) |
| Init = CGM.EmitConstantExpr(D.getInit(), this); |
| else { |
| assert(getContext().getLangOptions().CPlusPlus && |
| "only C++ supports non-constant static initializers!"); |
| return GenerateStaticCXXBlockVarDecl(D); |
| } |
| } |
| |
| assert(Init && "Unable to create initialiser for static decl"); |
| |
| std::string ContextName; |
| if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurFuncDecl)) |
| ContextName = FD->getNameAsString(); |
| else if (isa<ObjCMethodDecl>(CurFuncDecl)) |
| ContextName = std::string(CurFn->getNameStart(), |
| CurFn->getNameStart() + CurFn->getNameLen()); |
| else |
| assert(0 && "Unknown context for block var decl"); |
| |
| llvm::GlobalValue *GV = |
| new llvm::GlobalVariable(Init->getType(), false, |
| llvm::GlobalValue::InternalLinkage, |
| Init, ContextName + Separator +D.getNameAsString(), |
| &CGM.getModule(), 0, Ty.getAddressSpace()); |
| |
| return GV; |
| } |
| |
| void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) { |
| |
| llvm::Value *&DMEntry = LocalDeclMap[&D]; |
| assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); |
| |
| llvm::GlobalValue *GV = GenerateStaticBlockVarDecl(D, false, "."); |
| |
| 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); |
| } |
| |
| 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 = CGM.getDebugInfo(); |
| if(DI) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D); |
| } |
| |
| } |
| |
| /// 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(); |
| |
| 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 = ConvertType(Ty); |
| llvm::AllocaInst *Alloc = |
| CreateTempAlloca(LTy, D.getIdentifier()->getName()); |
| unsigned align = getContext().getTypeAlign(Ty); |
| if (const AlignedAttr* AA = D.getAttr<AlignedAttr>()) |
| align = std::max(align, AA->getAlignment()); |
| Alloc->setAlignment(align >> 3); |
| DeclPtr = Alloc; |
| } else { |
| // Targets that don't support recursion emit locals as globals. |
| const char *Class = |
| D.getStorageClass() == VarDecl::Register ? ".reg." : ".auto."; |
| DeclPtr = GenerateStaticBlockVarDecl(D, true, Class); |
| } |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVLASize(Ty); |
| } else { |
| if (!StackSaveValues.back()) { |
| // 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); |
| |
| StackSaveValues.back() = Stack; |
| } |
| // Get the element type. |
| const llvm::Type *LElemTy = ConvertType(Ty); |
| const llvm::Type *LElemPtrTy = |
| llvm::PointerType::get(LElemTy, D.getType().getAddressSpace()); |
| |
| llvm::Value *VLASize = EmitVLASize(Ty); |
| |
| // 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 = CGM.getDebugInfo()) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder); |
| } |
| |
| // If this local has an initializer, emit it now. |
| if (const Expr *Init = D.getInit()) { |
| if (!hasAggregateLLVMType(Init->getType())) { |
| llvm::Value *V = EmitScalarExpr(Init); |
| Builder.CreateStore(V, DeclPtr, D.getType().isVolatileQualified()); |
| } else if (Init->getType()->isAnyComplexType()) { |
| EmitComplexExprIntoAddr(Init, DeclPtr, D.getType().isVolatileQualified()); |
| } else { |
| EmitAggExpr(Init, DeclPtr, D.getType().isVolatileQualified()); |
| } |
| } |
| } |
| |
| /// 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 if (Target.useGlobalsForAutomaticVariables()) { |
| DeclPtr = GenerateStaticBlockVarDecl(D, true, ".arg."); |
| } else { |
| // A fixed sized single-value variable becomes an alloca in the entry block. |
| const llvm::Type *LTy = ConvertType(Ty); |
| if (LTy->isSingleValueType()) { |
| // TODO: Alignment |
| std::string Name = D.getNameAsString(); |
| Name += ".addr"; |
| DeclPtr = CreateTempAlloca(LTy, Name.c_str()); |
| |
| // Store the initial value into the alloca. |
| Builder.CreateStore(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 = CGM.getDebugInfo()) { |
| DI->setLocation(D.getLocation()); |
| DI->EmitDeclareOfArgVariable(&D, DeclPtr, Builder); |
| } |
| } |
| |