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-rw-r--r--lib/CodeGen/CGDecl.cpp489
1 files changed, 489 insertions, 0 deletions
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
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--- /dev/null
+++ b/lib/CodeGen/CGDecl.cpp
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+//===--- 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.getType()->isReferenceType()) {
+ CGM.ErrorUnsupported(&D, "static declaration with reference type");
+ return;
+ }
+
+ 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 (Target.useGlobalsForAutomaticVariables()) {
+ DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
+ }
+ else if (isByRef) {
+ llvm::Value *Loc;
+ bool needsCopyDispose = BlockRequiresCopying(Ty);
+ Loc = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
+ Loc = Builder.CreateLoad(Loc, false);
+ Loc = Builder.CreateBitCast(Loc, DeclPtr->getType());
+ Loc = Builder.CreateStructGEP(Loc, 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 (Ty->isReferenceType()) {
+ llvm::Value *V = EmitReferenceBindingToExpr(Init, Ty).getScalarVal();
+ EmitStoreOfScalar(V, Loc, false, Ty);
+ } else if (!hasAggregateLLVMType(Init->getType())) {
+ llvm::Value *V = EmitScalarExpr(Init);
+ EmitStoreOfScalar(V, Loc, D.getType().isVolatileQualified(),
+ D.getType());
+ } 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(GlobalDecl(FD));
+ assert(F && "Could not find function!");
+
+ CleanupScope scope(*this);
+
+ const CGFunctionInfo &Info = CGM.getTypes().getFunctionInfo(FD);
+
+ // In some cases, the type of the function argument will be different from
+ // the type of the pointer. An example of this is
+ // void f(void* arg);
+ // __attribute__((cleanup(f))) void *g;
+ //
+ // To fix this we insert a bitcast here.
+ QualType ArgTy = Info.arg_begin()->type;
+ DeclPtr = Builder.CreateBitCast(DeclPtr, ConvertType(ArgTy));
+
+ CallArgList Args;
+ Args.push_back(std::make_pair(RValue::get(DeclPtr),
+ getContext().getPointerType(D.getType())));
+
+ EmitCall(Info, 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(), Ty);
+ } 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);
+ }
+}
+
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