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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp | 2996 |
1 files changed, 2996 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp new file mode 100644 index 000000000000..c518a5554e2a --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp @@ -0,0 +1,2996 @@ +//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This coordinates the per-module state used while generating code. +// +//===----------------------------------------------------------------------===// + +#include "CodeGenModule.h" +#include "CGCUDARuntime.h" +#include "CGCXXABI.h" +#include "CGCall.h" +#include "CGDebugInfo.h" +#include "CGObjCRuntime.h" +#include "CGOpenCLRuntime.h" +#include "CodeGenFunction.h" +#include "CodeGenTBAA.h" +#include "TargetInfo.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/CharUnits.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/DeclTemplate.h" +#include "clang/AST/Mangle.h" +#include "clang/AST/RecordLayout.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/Basic/Builtins.h" +#include "clang/Basic/CharInfo.h" +#include "clang/Basic/Diagnostic.h" +#include "clang/Basic/Module.h" +#include "clang/Basic/SourceManager.h" +#include "clang/Basic/TargetInfo.h" +#include "clang/Basic/TargetOptions.h" +#include "clang/Frontend/CodeGenOptions.h" +#include "llvm/ADT/APSInt.h" +#include "llvm/ADT/Triple.h" +#include "llvm/IR/CallingConv.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Support/ConvertUTF.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Target/Mangler.h" + +using namespace clang; +using namespace CodeGen; + +static const char AnnotationSection[] = "llvm.metadata"; + +static CGCXXABI &createCXXABI(CodeGenModule &CGM) { + switch (CGM.getContext().getTargetInfo().getCXXABI().getKind()) { + case TargetCXXABI::GenericAArch64: + case TargetCXXABI::GenericARM: + case TargetCXXABI::iOS: + case TargetCXXABI::GenericItanium: + return *CreateItaniumCXXABI(CGM); + case TargetCXXABI::Microsoft: + return *CreateMicrosoftCXXABI(CGM); + } + + llvm_unreachable("invalid C++ ABI kind"); +} + + +CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, + const TargetOptions &TO, llvm::Module &M, + const llvm::DataLayout &TD, + DiagnosticsEngine &diags) + : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TargetOpts(TO), + TheModule(M), TheDataLayout(TD), TheTargetCodeGenInfo(0), Diags(diags), + ABI(createCXXABI(*this)), + Types(*this), + TBAA(0), + VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), + DebugInfo(0), ARCData(0), NoObjCARCExceptionsMetadata(0), + RRData(0), CFConstantStringClassRef(0), + ConstantStringClassRef(0), NSConstantStringType(0), + VMContext(M.getContext()), + NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), + BlockObjectAssign(0), BlockObjectDispose(0), + BlockDescriptorType(0), GenericBlockLiteralType(0), + LifetimeStartFn(0), LifetimeEndFn(0), + SanitizerBlacklist(CGO.SanitizerBlacklistFile), + SanOpts(SanitizerBlacklist.isIn(M) ? + SanitizerOptions::Disabled : LangOpts.Sanitize) { + + // Initialize the type cache. + llvm::LLVMContext &LLVMContext = M.getContext(); + VoidTy = llvm::Type::getVoidTy(LLVMContext); + Int8Ty = llvm::Type::getInt8Ty(LLVMContext); + Int16Ty = llvm::Type::getInt16Ty(LLVMContext); + Int32Ty = llvm::Type::getInt32Ty(LLVMContext); + Int64Ty = llvm::Type::getInt64Ty(LLVMContext); + FloatTy = llvm::Type::getFloatTy(LLVMContext); + DoubleTy = llvm::Type::getDoubleTy(LLVMContext); + PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); + PointerAlignInBytes = + C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); + IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); + IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); + Int8PtrTy = Int8Ty->getPointerTo(0); + Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); + + RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC(); + + if (LangOpts.ObjC1) + createObjCRuntime(); + if (LangOpts.OpenCL) + createOpenCLRuntime(); + if (LangOpts.CUDA) + createCUDARuntime(); + + // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0. + if (SanOpts.Thread || + (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)) + TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(), + ABI.getMangleContext()); + + // If debug info or coverage generation is enabled, create the CGDebugInfo + // object. + if (CodeGenOpts.getDebugInfo() != CodeGenOptions::NoDebugInfo || + CodeGenOpts.EmitGcovArcs || + CodeGenOpts.EmitGcovNotes) + DebugInfo = new CGDebugInfo(*this); + + Block.GlobalUniqueCount = 0; + + if (C.getLangOpts().ObjCAutoRefCount) + ARCData = new ARCEntrypoints(); + RRData = new RREntrypoints(); +} + +CodeGenModule::~CodeGenModule() { + delete ObjCRuntime; + delete OpenCLRuntime; + delete CUDARuntime; + delete TheTargetCodeGenInfo; + delete &ABI; + delete TBAA; + delete DebugInfo; + delete ARCData; + delete RRData; +} + +void CodeGenModule::createObjCRuntime() { + // This is just isGNUFamily(), but we want to force implementors of + // new ABIs to decide how best to do this. + switch (LangOpts.ObjCRuntime.getKind()) { + case ObjCRuntime::GNUstep: + case ObjCRuntime::GCC: + case ObjCRuntime::ObjFW: + ObjCRuntime = CreateGNUObjCRuntime(*this); + return; + + case ObjCRuntime::FragileMacOSX: + case ObjCRuntime::MacOSX: + case ObjCRuntime::iOS: + ObjCRuntime = CreateMacObjCRuntime(*this); + return; + } + llvm_unreachable("bad runtime kind"); +} + +void CodeGenModule::createOpenCLRuntime() { + OpenCLRuntime = new CGOpenCLRuntime(*this); +} + +void CodeGenModule::createCUDARuntime() { + CUDARuntime = CreateNVCUDARuntime(*this); +} + +void CodeGenModule::Release() { + EmitDeferred(); + EmitCXXGlobalInitFunc(); + EmitCXXGlobalDtorFunc(); + if (ObjCRuntime) + if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) + AddGlobalCtor(ObjCInitFunction); + EmitCtorList(GlobalCtors, "llvm.global_ctors"); + EmitCtorList(GlobalDtors, "llvm.global_dtors"); + EmitGlobalAnnotations(); + EmitLLVMUsed(); + + if (CodeGenOpts.ModulesAutolink) { + EmitModuleLinkOptions(); + } + + SimplifyPersonality(); + + if (getCodeGenOpts().EmitDeclMetadata) + EmitDeclMetadata(); + + if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) + EmitCoverageFile(); + + if (DebugInfo) + DebugInfo->finalize(); +} + +void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { + // Make sure that this type is translated. + Types.UpdateCompletedType(TD); +} + +llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { + if (!TBAA) + return 0; + return TBAA->getTBAAInfo(QTy); +} + +llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { + if (!TBAA) + return 0; + return TBAA->getTBAAInfoForVTablePtr(); +} + +llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { + if (!TBAA) + return 0; + return TBAA->getTBAAStructInfo(QTy); +} + +llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) { + if (!TBAA) + return 0; + return TBAA->getTBAAStructTypeInfo(QTy); +} + +llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, + llvm::MDNode *AccessN, + uint64_t O) { + if (!TBAA) + return 0; + return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); +} + +void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, + llvm::MDNode *TBAAInfo) { + Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); +} + +bool CodeGenModule::isTargetDarwin() const { + return getContext().getTargetInfo().getTriple().isOSDarwin(); +} + +void CodeGenModule::Error(SourceLocation loc, StringRef error) { + unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); + getDiags().Report(Context.getFullLoc(loc), diagID); +} + +/// ErrorUnsupported - Print out an error that codegen doesn't support the +/// specified stmt yet. +void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, + bool OmitOnError) { + if (OmitOnError && getDiags().hasErrorOccurred()) + return; + unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, + "cannot compile this %0 yet"); + std::string Msg = Type; + getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) + << Msg << S->getSourceRange(); +} + +/// ErrorUnsupported - Print out an error that codegen doesn't support the +/// specified decl yet. +void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, + bool OmitOnError) { + if (OmitOnError && getDiags().hasErrorOccurred()) + return; + unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, + "cannot compile this %0 yet"); + std::string Msg = Type; + getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; +} + +llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { + return llvm::ConstantInt::get(SizeTy, size.getQuantity()); +} + +void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, + const NamedDecl *D) const { + // Internal definitions always have default visibility. + if (GV->hasLocalLinkage()) { + GV->setVisibility(llvm::GlobalValue::DefaultVisibility); + return; + } + + // Set visibility for definitions. + LinkageInfo LV = D->getLinkageAndVisibility(); + if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage()) + GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); +} + +static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { + return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) + .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) + .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) + .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) + .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); +} + +static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( + CodeGenOptions::TLSModel M) { + switch (M) { + case CodeGenOptions::GeneralDynamicTLSModel: + return llvm::GlobalVariable::GeneralDynamicTLSModel; + case CodeGenOptions::LocalDynamicTLSModel: + return llvm::GlobalVariable::LocalDynamicTLSModel; + case CodeGenOptions::InitialExecTLSModel: + return llvm::GlobalVariable::InitialExecTLSModel; + case CodeGenOptions::LocalExecTLSModel: + return llvm::GlobalVariable::LocalExecTLSModel; + } + llvm_unreachable("Invalid TLS model!"); +} + +void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, + const VarDecl &D) const { + assert(D.isThreadSpecified() && "setting TLS mode on non-TLS var!"); + + llvm::GlobalVariable::ThreadLocalMode TLM; + TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); + + // Override the TLS model if it is explicitly specified. + if (D.hasAttr<TLSModelAttr>()) { + const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); + TLM = GetLLVMTLSModel(Attr->getModel()); + } + + GV->setThreadLocalMode(TLM); +} + +/// Set the symbol visibility of type information (vtable and RTTI) +/// associated with the given type. +void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, + const CXXRecordDecl *RD, + TypeVisibilityKind TVK) const { + setGlobalVisibility(GV, RD); + + if (!CodeGenOpts.HiddenWeakVTables) + return; + + // We never want to drop the visibility for RTTI names. + if (TVK == TVK_ForRTTIName) + return; + + // We want to drop the visibility to hidden for weak type symbols. + // This isn't possible if there might be unresolved references + // elsewhere that rely on this symbol being visible. + + // This should be kept roughly in sync with setThunkVisibility + // in CGVTables.cpp. + + // Preconditions. + if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || + GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) + return; + + // Don't override an explicit visibility attribute. + if (RD->getExplicitVisibility(NamedDecl::VisibilityForType)) + return; + + switch (RD->getTemplateSpecializationKind()) { + // We have to disable the optimization if this is an EI definition + // because there might be EI declarations in other shared objects. + case TSK_ExplicitInstantiationDefinition: + case TSK_ExplicitInstantiationDeclaration: + return; + + // Every use of a non-template class's type information has to emit it. + case TSK_Undeclared: + break; + + // In theory, implicit instantiations can ignore the possibility of + // an explicit instantiation declaration because there necessarily + // must be an EI definition somewhere with default visibility. In + // practice, it's possible to have an explicit instantiation for + // an arbitrary template class, and linkers aren't necessarily able + // to deal with mixed-visibility symbols. + case TSK_ExplicitSpecialization: + case TSK_ImplicitInstantiation: + return; + } + + // If there's a key function, there may be translation units + // that don't have the key function's definition. But ignore + // this if we're emitting RTTI under -fno-rtti. + if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { + // FIXME: what should we do if we "lose" the key function during + // the emission of the file? + if (Context.getCurrentKeyFunction(RD)) + return; + } + + // Otherwise, drop the visibility to hidden. + GV->setVisibility(llvm::GlobalValue::HiddenVisibility); + GV->setUnnamedAddr(true); +} + +StringRef CodeGenModule::getMangledName(GlobalDecl GD) { + const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); + + StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; + if (!Str.empty()) + return Str; + + if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { + IdentifierInfo *II = ND->getIdentifier(); + assert(II && "Attempt to mangle unnamed decl."); + + Str = II->getName(); + return Str; + } + + SmallString<256> Buffer; + llvm::raw_svector_ostream Out(Buffer); + if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) + getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); + else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) + getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); + else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) + getCXXABI().getMangleContext().mangleBlock(BD, Out, + dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl())); + else + getCXXABI().getMangleContext().mangleName(ND, Out); + + // Allocate space for the mangled name. + Out.flush(); + size_t Length = Buffer.size(); + char *Name = MangledNamesAllocator.Allocate<char>(Length); + std::copy(Buffer.begin(), Buffer.end(), Name); + + Str = StringRef(Name, Length); + + return Str; +} + +void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, + const BlockDecl *BD) { + MangleContext &MangleCtx = getCXXABI().getMangleContext(); + const Decl *D = GD.getDecl(); + llvm::raw_svector_ostream Out(Buffer.getBuffer()); + if (D == 0) + MangleCtx.mangleGlobalBlock(BD, + dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); + else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) + MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); + else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) + MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); + else + MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); +} + +llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { + return getModule().getNamedValue(Name); +} + +/// AddGlobalCtor - Add a function to the list that will be called before +/// main() runs. +void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { + // FIXME: Type coercion of void()* types. + GlobalCtors.push_back(std::make_pair(Ctor, Priority)); +} + +/// AddGlobalDtor - Add a function to the list that will be called +/// when the module is unloaded. +void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { + // FIXME: Type coercion of void()* types. + GlobalDtors.push_back(std::make_pair(Dtor, Priority)); +} + +void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { + // Ctor function type is void()*. + llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); + llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); + + // Get the type of a ctor entry, { i32, void ()* }. + llvm::StructType *CtorStructTy = + llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); + + // Construct the constructor and destructor arrays. + SmallVector<llvm::Constant*, 8> Ctors; + for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { + llvm::Constant *S[] = { + llvm::ConstantInt::get(Int32Ty, I->second, false), + llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) + }; + Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); + } + + if (!Ctors.empty()) { + llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); + new llvm::GlobalVariable(TheModule, AT, false, + llvm::GlobalValue::AppendingLinkage, + llvm::ConstantArray::get(AT, Ctors), + GlobalName); + } +} + +llvm::GlobalValue::LinkageTypes +CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { + GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); + + if (Linkage == GVA_Internal) + return llvm::Function::InternalLinkage; + + if (D->hasAttr<DLLExportAttr>()) + return llvm::Function::DLLExportLinkage; + + if (D->hasAttr<WeakAttr>()) + return llvm::Function::WeakAnyLinkage; + + // In C99 mode, 'inline' functions are guaranteed to have a strong + // definition somewhere else, so we can use available_externally linkage. + if (Linkage == GVA_C99Inline) + return llvm::Function::AvailableExternallyLinkage; + + // Note that Apple's kernel linker doesn't support symbol + // coalescing, so we need to avoid linkonce and weak linkages there. + // Normally, this means we just map to internal, but for explicit + // instantiations we'll map to external. + + // In C++, the compiler has to emit a definition in every translation unit + // that references the function. We should use linkonce_odr because + // a) if all references in this translation unit are optimized away, we + // don't need to codegen it. b) if the function persists, it needs to be + // merged with other definitions. c) C++ has the ODR, so we know the + // definition is dependable. + if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) + return !Context.getLangOpts().AppleKext + ? llvm::Function::LinkOnceODRLinkage + : llvm::Function::InternalLinkage; + + // An explicit instantiation of a template has weak linkage, since + // explicit instantiations can occur in multiple translation units + // and must all be equivalent. However, we are not allowed to + // throw away these explicit instantiations. + if (Linkage == GVA_ExplicitTemplateInstantiation) + return !Context.getLangOpts().AppleKext + ? llvm::Function::WeakODRLinkage + : llvm::Function::ExternalLinkage; + + // Otherwise, we have strong external linkage. + assert(Linkage == GVA_StrongExternal); + return llvm::Function::ExternalLinkage; +} + + +/// SetFunctionDefinitionAttributes - Set attributes for a global. +/// +/// FIXME: This is currently only done for aliases and functions, but not for +/// variables (these details are set in EmitGlobalVarDefinition for variables). +void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, + llvm::GlobalValue *GV) { + SetCommonAttributes(D, GV); +} + +void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, + const CGFunctionInfo &Info, + llvm::Function *F) { + unsigned CallingConv; + AttributeListType AttributeList; + ConstructAttributeList(Info, D, AttributeList, CallingConv, false); + F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList)); + F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); +} + +/// Determines whether the language options require us to model +/// unwind exceptions. We treat -fexceptions as mandating this +/// except under the fragile ObjC ABI with only ObjC exceptions +/// enabled. This means, for example, that C with -fexceptions +/// enables this. +static bool hasUnwindExceptions(const LangOptions &LangOpts) { + // If exceptions are completely disabled, obviously this is false. + if (!LangOpts.Exceptions) return false; + + // If C++ exceptions are enabled, this is true. + if (LangOpts.CXXExceptions) return true; + + // If ObjC exceptions are enabled, this depends on the ABI. + if (LangOpts.ObjCExceptions) { + return LangOpts.ObjCRuntime.hasUnwindExceptions(); + } + + return true; +} + +void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, + llvm::Function *F) { + if (CodeGenOpts.UnwindTables) + F->setHasUWTable(); + + if (!hasUnwindExceptions(LangOpts)) + F->addFnAttr(llvm::Attribute::NoUnwind); + + if (D->hasAttr<NakedAttr>()) { + // Naked implies noinline: we should not be inlining such functions. + F->addFnAttr(llvm::Attribute::Naked); + F->addFnAttr(llvm::Attribute::NoInline); + } + + if (D->hasAttr<NoInlineAttr>()) + F->addFnAttr(llvm::Attribute::NoInline); + + // (noinline wins over always_inline, and we can't specify both in IR) + if ((D->hasAttr<AlwaysInlineAttr>() || D->hasAttr<ForceInlineAttr>()) && + !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, + llvm::Attribute::NoInline)) + F->addFnAttr(llvm::Attribute::AlwaysInline); + + // FIXME: Communicate hot and cold attributes to LLVM more directly. + if (D->hasAttr<ColdAttr>()) + F->addFnAttr(llvm::Attribute::OptimizeForSize); + + if (D->hasAttr<MinSizeAttr>()) + F->addFnAttr(llvm::Attribute::MinSize); + + if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) + F->setUnnamedAddr(true); + + if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) + if (MD->isVirtual()) + F->setUnnamedAddr(true); + + if (LangOpts.getStackProtector() == LangOptions::SSPOn) + F->addFnAttr(llvm::Attribute::StackProtect); + else if (LangOpts.getStackProtector() == LangOptions::SSPReq) + F->addFnAttr(llvm::Attribute::StackProtectReq); + + // Add sanitizer attributes if function is not blacklisted. + if (!SanitizerBlacklist.isIn(*F)) { + // When AddressSanitizer is enabled, set SanitizeAddress attribute + // unless __attribute__((no_sanitize_address)) is used. + if (SanOpts.Address && !D->hasAttr<NoSanitizeAddressAttr>()) + F->addFnAttr(llvm::Attribute::SanitizeAddress); + // Same for ThreadSanitizer and __attribute__((no_sanitize_thread)) + if (SanOpts.Thread && !D->hasAttr<NoSanitizeThreadAttr>()) { + F->addFnAttr(llvm::Attribute::SanitizeThread); + } + // Same for MemorySanitizer and __attribute__((no_sanitize_memory)) + if (SanOpts.Memory && !D->hasAttr<NoSanitizeMemoryAttr>()) + F->addFnAttr(llvm::Attribute::SanitizeMemory); + } + + unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); + if (alignment) + F->setAlignment(alignment); + + // C++ ABI requires 2-byte alignment for member functions. + if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) + F->setAlignment(2); +} + +void CodeGenModule::SetCommonAttributes(const Decl *D, + llvm::GlobalValue *GV) { + if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) + setGlobalVisibility(GV, ND); + else + GV->setVisibility(llvm::GlobalValue::DefaultVisibility); + + if (D->hasAttr<UsedAttr>()) + AddUsedGlobal(GV); + + if (const SectionAttr *SA = D->getAttr<SectionAttr>()) + GV->setSection(SA->getName()); + + // Alias cannot have attributes. Filter them here. + if (!isa<llvm::GlobalAlias>(GV)) + getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); +} + +void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, + llvm::Function *F, + const CGFunctionInfo &FI) { + SetLLVMFunctionAttributes(D, FI, F); + SetLLVMFunctionAttributesForDefinition(D, F); + + F->setLinkage(llvm::Function::InternalLinkage); + + SetCommonAttributes(D, F); +} + +void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, + llvm::Function *F, + bool IsIncompleteFunction) { + if (unsigned IID = F->getIntrinsicID()) { + // If this is an intrinsic function, set the function's attributes + // to the intrinsic's attributes. + F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), + (llvm::Intrinsic::ID)IID)); + return; + } + + const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); + + if (!IsIncompleteFunction) + SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); + + // Only a few attributes are set on declarations; these may later be + // overridden by a definition. + + if (FD->hasAttr<DLLImportAttr>()) { + F->setLinkage(llvm::Function::DLLImportLinkage); + } else if (FD->hasAttr<WeakAttr>() || + FD->isWeakImported()) { + // "extern_weak" is overloaded in LLVM; we probably should have + // separate linkage types for this. + F->setLinkage(llvm::Function::ExternalWeakLinkage); + } else { + F->setLinkage(llvm::Function::ExternalLinkage); + + LinkageInfo LV = FD->getLinkageAndVisibility(); + if (LV.getLinkage() == ExternalLinkage && LV.isVisibilityExplicit()) { + F->setVisibility(GetLLVMVisibility(LV.getVisibility())); + } + } + + if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) + F->setSection(SA->getName()); +} + +void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { + assert(!GV->isDeclaration() && + "Only globals with definition can force usage."); + LLVMUsed.push_back(GV); +} + +void CodeGenModule::EmitLLVMUsed() { + // Don't create llvm.used if there is no need. + if (LLVMUsed.empty()) + return; + + // Convert LLVMUsed to what ConstantArray needs. + SmallVector<llvm::Constant*, 8> UsedArray; + UsedArray.resize(LLVMUsed.size()); + for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { + UsedArray[i] = + llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), + Int8PtrTy); + } + + if (UsedArray.empty()) + return; + llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); + + llvm::GlobalVariable *GV = + new llvm::GlobalVariable(getModule(), ATy, false, + llvm::GlobalValue::AppendingLinkage, + llvm::ConstantArray::get(ATy, UsedArray), + "llvm.used"); + + GV->setSection("llvm.metadata"); +} + +/// \brief Add link options implied by the given module, including modules +/// it depends on, using a postorder walk. +static void addLinkOptionsPostorder(llvm::LLVMContext &Context, + Module *Mod, + SmallVectorImpl<llvm::Value *> &Metadata, + llvm::SmallPtrSet<Module *, 16> &Visited) { + // Import this module's parent. + if (Mod->Parent && Visited.insert(Mod->Parent)) { + addLinkOptionsPostorder(Context, Mod->Parent, Metadata, Visited); + } + + // Import this module's dependencies. + for (unsigned I = Mod->Imports.size(); I > 0; --I) { + if (Visited.insert(Mod->Imports[I-1])) + addLinkOptionsPostorder(Context, Mod->Imports[I-1], Metadata, Visited); + } + + // Add linker options to link against the libraries/frameworks + // described by this module. + for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { + // FIXME: -lfoo is Unix-centric and -framework Foo is Darwin-centric. + // We need to know more about the linker to know how to encode these + // options propertly. + + // Link against a framework. + if (Mod->LinkLibraries[I-1].IsFramework) { + llvm::Value *Args[2] = { + llvm::MDString::get(Context, "-framework"), + llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library) + }; + + Metadata.push_back(llvm::MDNode::get(Context, Args)); + continue; + } + + // Link against a library. + llvm::Value *OptString + = llvm::MDString::get(Context, + "-l" + Mod->LinkLibraries[I-1].Library); + Metadata.push_back(llvm::MDNode::get(Context, OptString)); + } +} + +void CodeGenModule::EmitModuleLinkOptions() { + // Collect the set of all of the modules we want to visit to emit link + // options, which is essentially the imported modules and all of their + // non-explicit child modules. + llvm::SetVector<clang::Module *> LinkModules; + llvm::SmallPtrSet<clang::Module *, 16> Visited; + SmallVector<clang::Module *, 16> Stack; + + // Seed the stack with imported modules. + for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(), + MEnd = ImportedModules.end(); + M != MEnd; ++M) { + if (Visited.insert(*M)) + Stack.push_back(*M); + } + + // Find all of the modules to import, making a little effort to prune + // non-leaf modules. + while (!Stack.empty()) { + clang::Module *Mod = Stack.back(); + Stack.pop_back(); + + bool AnyChildren = false; + + // Visit the submodules of this module. + for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), + SubEnd = Mod->submodule_end(); + Sub != SubEnd; ++Sub) { + // Skip explicit children; they need to be explicitly imported to be + // linked against. + if ((*Sub)->IsExplicit) + continue; + + if (Visited.insert(*Sub)) { + Stack.push_back(*Sub); + AnyChildren = true; + } + } + + // We didn't find any children, so add this module to the list of + // modules to link against. + if (!AnyChildren) { + LinkModules.insert(Mod); + } + } + + // Add link options for all of the imported modules in reverse topological + // order. + SmallVector<llvm::Value *, 16> MetadataArgs; + Visited.clear(); + for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(), + MEnd = LinkModules.end(); + M != MEnd; ++M) { + if (Visited.insert(*M)) + addLinkOptionsPostorder(getLLVMContext(), *M, MetadataArgs, Visited); + } + std::reverse(MetadataArgs.begin(), MetadataArgs.end()); + + // Add the linker options metadata flag. + getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", + llvm::MDNode::get(getLLVMContext(), MetadataArgs)); +} + +void CodeGenModule::EmitDeferred() { + // Emit code for any potentially referenced deferred decls. Since a + // previously unused static decl may become used during the generation of code + // for a static function, iterate until no changes are made. + + while (true) { + if (!DeferredVTables.empty()) { + EmitDeferredVTables(); + + // Emitting a v-table doesn't directly cause more v-tables to + // become deferred, although it can cause functions to be + // emitted that then need those v-tables. + assert(DeferredVTables.empty()); + } + + // Stop if we're out of both deferred v-tables and deferred declarations. + if (DeferredDeclsToEmit.empty()) break; + + GlobalDecl D = DeferredDeclsToEmit.back(); + DeferredDeclsToEmit.pop_back(); + + // Check to see if we've already emitted this. This is necessary + // for a couple of reasons: first, decls can end up in the + // deferred-decls queue multiple times, and second, decls can end + // up with definitions in unusual ways (e.g. by an extern inline + // function acquiring a strong function redefinition). Just + // ignore these cases. + // + // TODO: That said, looking this up multiple times is very wasteful. + StringRef Name = getMangledName(D); + llvm::GlobalValue *CGRef = GetGlobalValue(Name); + assert(CGRef && "Deferred decl wasn't referenced?"); + + if (!CGRef->isDeclaration()) + continue; + + // GlobalAlias::isDeclaration() defers to the aliasee, but for our + // purposes an alias counts as a definition. + if (isa<llvm::GlobalAlias>(CGRef)) + continue; + + // Otherwise, emit the definition and move on to the next one. + EmitGlobalDefinition(D); + } +} + +void CodeGenModule::EmitGlobalAnnotations() { + if (Annotations.empty()) + return; + + // Create a new global variable for the ConstantStruct in the Module. + llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( + Annotations[0]->getType(), Annotations.size()), Annotations); + llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), + Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, + "llvm.global.annotations"); + gv->setSection(AnnotationSection); +} + +llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { + llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); + if (i != AnnotationStrings.end()) + return i->second; + + // Not found yet, create a new global. + llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); + llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), + true, llvm::GlobalValue::PrivateLinkage, s, ".str"); + gv->setSection(AnnotationSection); + gv->setUnnamedAddr(true); + AnnotationStrings[Str] = gv; + return gv; +} + +llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { + SourceManager &SM = getContext().getSourceManager(); + PresumedLoc PLoc = SM.getPresumedLoc(Loc); + if (PLoc.isValid()) + return EmitAnnotationString(PLoc.getFilename()); + return EmitAnnotationString(SM.getBufferName(Loc)); +} + +llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { + SourceManager &SM = getContext().getSourceManager(); + PresumedLoc PLoc = SM.getPresumedLoc(L); + unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : + SM.getExpansionLineNumber(L); + return llvm::ConstantInt::get(Int32Ty, LineNo); +} + +llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, + const AnnotateAttr *AA, + SourceLocation L) { + // Get the globals for file name, annotation, and the line number. + llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), + *UnitGV = EmitAnnotationUnit(L), + *LineNoCst = EmitAnnotationLineNo(L); + + // Create the ConstantStruct for the global annotation. + llvm::Constant *Fields[4] = { + llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), + llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), + llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), + LineNoCst + }; + return llvm::ConstantStruct::getAnon(Fields); +} + +void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, + llvm::GlobalValue *GV) { + assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); + // Get the struct elements for these annotations. + for (specific_attr_iterator<AnnotateAttr> + ai = D->specific_attr_begin<AnnotateAttr>(), + ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) + Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); +} + +bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { + // Never defer when EmitAllDecls is specified. + if (LangOpts.EmitAllDecls) + return false; + + return !getContext().DeclMustBeEmitted(Global); +} + +llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( + const CXXUuidofExpr* E) { + // Sema has verified that IIDSource has a __declspec(uuid()), and that its + // well-formed. + StringRef Uuid; + if (E->isTypeOperand()) + Uuid = CXXUuidofExpr::GetUuidAttrOfType(E->getTypeOperand())->getGuid(); + else { + // Special case: __uuidof(0) means an all-zero GUID. + Expr *Op = E->getExprOperand(); + if (!Op->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) + Uuid = CXXUuidofExpr::GetUuidAttrOfType(Op->getType())->getGuid(); + else + Uuid = "00000000-0000-0000-0000-000000000000"; + } + std::string Name = "__uuid_" + Uuid.str(); + + // Look for an existing global. + if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) + return GV; + + llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); + assert(Init && "failed to initialize as constant"); + + // GUIDs are assumed to be 16 bytes, spread over 4-2-2-8 bytes. However, the + // first field is declared as "long", which for many targets is 8 bytes. + // Those architectures are not supported. (With the MS abi, long is always 4 + // bytes.) + llvm::Type *GuidType = getTypes().ConvertType(E->getType()); + if (Init->getType() != GuidType) { + DiagnosticsEngine &Diags = getDiags(); + unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, + "__uuidof codegen is not supported on this architecture"); + Diags.Report(E->getExprLoc(), DiagID) << E->getSourceRange(); + Init = llvm::UndefValue::get(GuidType); + } + + llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), GuidType, + /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Init, Name); + GV->setUnnamedAddr(true); + return GV; +} + +llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { + const AliasAttr *AA = VD->getAttr<AliasAttr>(); + assert(AA && "No alias?"); + + llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); + + // See if there is already something with the target's name in the module. + llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); + if (Entry) { + unsigned AS = getContext().getTargetAddressSpace(VD->getType()); + return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); + } + + llvm::Constant *Aliasee; + if (isa<llvm::FunctionType>(DeclTy)) + Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, + GlobalDecl(cast<FunctionDecl>(VD)), + /*ForVTable=*/false); + else + Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), + llvm::PointerType::getUnqual(DeclTy), 0); + + llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); + F->setLinkage(llvm::Function::ExternalWeakLinkage); + WeakRefReferences.insert(F); + + return Aliasee; +} + +void CodeGenModule::EmitGlobal(GlobalDecl GD) { + const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); + + // Weak references don't produce any output by themselves. + if (Global->hasAttr<WeakRefAttr>()) + return; + + // If this is an alias definition (which otherwise looks like a declaration) + // emit it now. + if (Global->hasAttr<AliasAttr>()) + return EmitAliasDefinition(GD); + + // If this is CUDA, be selective about which declarations we emit. + if (LangOpts.CUDA) { + if (CodeGenOpts.CUDAIsDevice) { + if (!Global->hasAttr<CUDADeviceAttr>() && + !Global->hasAttr<CUDAGlobalAttr>() && + !Global->hasAttr<CUDAConstantAttr>() && + !Global->hasAttr<CUDASharedAttr>()) + return; + } else { + if (!Global->hasAttr<CUDAHostAttr>() && ( + Global->hasAttr<CUDADeviceAttr>() || + Global->hasAttr<CUDAConstantAttr>() || + Global->hasAttr<CUDASharedAttr>())) + return; + } + } + + // Ignore declarations, they will be emitted on their first use. + if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { + // Forward declarations are emitted lazily on first use. + if (!FD->doesThisDeclarationHaveABody()) { + if (!FD->doesDeclarationForceExternallyVisibleDefinition()) + return; + + const FunctionDecl *InlineDefinition = 0; + FD->getBody(InlineDefinition); + + StringRef MangledName = getMangledName(GD); + DeferredDecls.erase(MangledName); + EmitGlobalDefinition(InlineDefinition); + return; + } + } else { + const VarDecl *VD = cast<VarDecl>(Global); + assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); + + if (VD->isThisDeclarationADefinition() != VarDecl::Definition) + return; + } + + // Defer code generation when possible if this is a static definition, inline + // function etc. These we only want to emit if they are used. + if (!MayDeferGeneration(Global)) { + // Emit the definition if it can't be deferred. + EmitGlobalDefinition(GD); + return; + } + + // If we're deferring emission of a C++ variable with an + // initializer, remember the order in which it appeared in the file. + if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && + cast<VarDecl>(Global)->hasInit()) { + DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); + CXXGlobalInits.push_back(0); + } + + // If the value has already been used, add it directly to the + // DeferredDeclsToEmit list. + StringRef MangledName = getMangledName(GD); + if (GetGlobalValue(MangledName)) + DeferredDeclsToEmit.push_back(GD); + else { + // Otherwise, remember that we saw a deferred decl with this name. The + // first use of the mangled name will cause it to move into + // DeferredDeclsToEmit. + DeferredDecls[MangledName] = GD; + } +} + +namespace { + struct FunctionIsDirectlyRecursive : + public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { + const StringRef Name; + const Builtin::Context &BI; + bool Result; + FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : + Name(N), BI(C), Result(false) { + } + typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; + + bool TraverseCallExpr(CallExpr *E) { + const FunctionDecl *FD = E->getDirectCallee(); + if (!FD) + return true; + AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); + if (Attr && Name == Attr->getLabel()) { + Result = true; + return false; + } + unsigned BuiltinID = FD->getBuiltinID(); + if (!BuiltinID) + return true; + StringRef BuiltinName = BI.GetName(BuiltinID); + if (BuiltinName.startswith("__builtin_") && + Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { + Result = true; + return false; + } + return true; + } + }; +} + +// isTriviallyRecursive - Check if this function calls another +// decl that, because of the asm attribute or the other decl being a builtin, +// ends up pointing to itself. +bool +CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { + StringRef Name; + if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { + // asm labels are a special kind of mangling we have to support. + AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); + if (!Attr) + return false; + Name = Attr->getLabel(); + } else { + Name = FD->getName(); + } + + FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); + Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); + return Walker.Result; +} + +bool +CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { + if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) + return true; + if (CodeGenOpts.OptimizationLevel == 0 && + !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) + return false; + // PR9614. Avoid cases where the source code is lying to us. An available + // externally function should have an equivalent function somewhere else, + // but a function that calls itself is clearly not equivalent to the real + // implementation. + // This happens in glibc's btowc and in some configure checks. + return !isTriviallyRecursive(F); +} + +void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { + const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); + + PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), + Context.getSourceManager(), + "Generating code for declaration"); + + if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { + // At -O0, don't generate IR for functions with available_externally + // linkage. + if (!shouldEmitFunction(Function)) + return; + + if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { + // Make sure to emit the definition(s) before we emit the thunks. + // This is necessary for the generation of certain thunks. + if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) + EmitCXXConstructor(CD, GD.getCtorType()); + else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) + EmitCXXDestructor(DD, GD.getDtorType()); + else + EmitGlobalFunctionDefinition(GD); + + if (Method->isVirtual()) + getVTables().EmitThunks(GD); + + return; + } + + return EmitGlobalFunctionDefinition(GD); + } + + if (const VarDecl *VD = dyn_cast<VarDecl>(D)) + return EmitGlobalVarDefinition(VD); + + llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); +} + +/// GetOrCreateLLVMFunction - If the specified mangled name is not in the +/// module, create and return an llvm Function with the specified type. If there +/// is something in the module with the specified name, return it potentially +/// bitcasted to the right type. +/// +/// If D is non-null, it specifies a decl that correspond to this. This is used +/// to set the attributes on the function when it is first created. +llvm::Constant * +CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, + llvm::Type *Ty, + GlobalDecl D, bool ForVTable, + llvm::AttributeSet ExtraAttrs) { + // Lookup the entry, lazily creating it if necessary. + llvm::GlobalValue *Entry = GetGlobalValue(MangledName); + if (Entry) { + if (WeakRefReferences.erase(Entry)) { + const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); + if (FD && !FD->hasAttr<WeakAttr>()) + Entry->setLinkage(llvm::Function::ExternalLinkage); + } + + if (Entry->getType()->getElementType() == Ty) + return Entry; + + // Make sure the result is of the correct type. + return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); + } + + // This function doesn't have a complete type (for example, the return + // type is an incomplete struct). Use a fake type instead, and make + // sure not to try to set attributes. + bool IsIncompleteFunction = false; + + llvm::FunctionType *FTy; + if (isa<llvm::FunctionType>(Ty)) { + FTy = cast<llvm::FunctionType>(Ty); + } else { + FTy = llvm::FunctionType::get(VoidTy, false); + IsIncompleteFunction = true; + } + + llvm::Function *F = llvm::Function::Create(FTy, + llvm::Function::ExternalLinkage, + MangledName, &getModule()); + assert(F->getName() == MangledName && "name was uniqued!"); + if (D.getDecl()) + SetFunctionAttributes(D, F, IsIncompleteFunction); + if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) { + llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex); + F->addAttributes(llvm::AttributeSet::FunctionIndex, + llvm::AttributeSet::get(VMContext, + llvm::AttributeSet::FunctionIndex, + B)); + } + + // This is the first use or definition of a mangled name. If there is a + // deferred decl with this name, remember that we need to emit it at the end + // of the file. + llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); + if (DDI != DeferredDecls.end()) { + // Move the potentially referenced deferred decl to the DeferredDeclsToEmit + // list, and remove it from DeferredDecls (since we don't need it anymore). + DeferredDeclsToEmit.push_back(DDI->second); + DeferredDecls.erase(DDI); + + // Otherwise, there are cases we have to worry about where we're + // using a declaration for which we must emit a definition but where + // we might not find a top-level definition: + // - member functions defined inline in their classes + // - friend functions defined inline in some class + // - special member functions with implicit definitions + // If we ever change our AST traversal to walk into class methods, + // this will be unnecessary. + // + // We also don't emit a definition for a function if it's going to be an entry + // in a vtable, unless it's already marked as used. + } else if (getLangOpts().CPlusPlus && D.getDecl()) { + // Look for a declaration that's lexically in a record. + const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); + FD = FD->getMostRecentDecl(); + do { + if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { + if (FD->isImplicit() && !ForVTable) { + assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); + DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); + break; + } else if (FD->doesThisDeclarationHaveABody()) { + DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); + break; + } + } + FD = FD->getPreviousDecl(); + } while (FD); + } + + // Make sure the result is of the requested type. + if (!IsIncompleteFunction) { + assert(F->getType()->getElementType() == Ty); + return F; + } + + llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); + return llvm::ConstantExpr::getBitCast(F, PTy); +} + +/// GetAddrOfFunction - Return the address of the given function. If Ty is +/// non-null, then this function will use the specified type if it has to +/// create it (this occurs when we see a definition of the function). +llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, + llvm::Type *Ty, + bool ForVTable) { + // If there was no specific requested type, just convert it now. + if (!Ty) + Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); + + StringRef MangledName = getMangledName(GD); + return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); +} + +/// CreateRuntimeFunction - Create a new runtime function with the specified +/// type and name. +llvm::Constant * +CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, + StringRef Name, + llvm::AttributeSet ExtraAttrs) { + llvm::Constant *C + = GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, + ExtraAttrs); + if (llvm::Function *F = dyn_cast<llvm::Function>(C)) + if (F->empty()) + F->setCallingConv(getRuntimeCC()); + return C; +} + +/// isTypeConstant - Determine whether an object of this type can be emitted +/// as a constant. +/// +/// If ExcludeCtor is true, the duration when the object's constructor runs +/// will not be considered. The caller will need to verify that the object is +/// not written to during its construction. +bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { + if (!Ty.isConstant(Context) && !Ty->isReferenceType()) + return false; + + if (Context.getLangOpts().CPlusPlus) { + if (const CXXRecordDecl *Record + = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) + return ExcludeCtor && !Record->hasMutableFields() && + Record->hasTrivialDestructor(); + } + + return true; +} + +/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, +/// create and return an llvm GlobalVariable with the specified type. If there +/// is something in the module with the specified name, return it potentially +/// bitcasted to the right type. +/// +/// If D is non-null, it specifies a decl that correspond to this. This is used +/// to set the attributes on the global when it is first created. +llvm::Constant * +CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, + llvm::PointerType *Ty, + const VarDecl *D, + bool UnnamedAddr) { + // Lookup the entry, lazily creating it if necessary. + llvm::GlobalValue *Entry = GetGlobalValue(MangledName); + if (Entry) { + if (WeakRefReferences.erase(Entry)) { + if (D && !D->hasAttr<WeakAttr>()) + Entry->setLinkage(llvm::Function::ExternalLinkage); + } + + if (UnnamedAddr) + Entry->setUnnamedAddr(true); + + if (Entry->getType() == Ty) + return Entry; + + // Make sure the result is of the correct type. + return llvm::ConstantExpr::getBitCast(Entry, Ty); + } + + // This is the first use or definition of a mangled name. If there is a + // deferred decl with this name, remember that we need to emit it at the end + // of the file. + llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); + if (DDI != DeferredDecls.end()) { + // Move the potentially referenced deferred decl to the DeferredDeclsToEmit + // list, and remove it from DeferredDecls (since we don't need it anymore). + DeferredDeclsToEmit.push_back(DDI->second); + DeferredDecls.erase(DDI); + } + + unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); + llvm::GlobalVariable *GV = + new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, + llvm::GlobalValue::ExternalLinkage, + 0, MangledName, 0, + llvm::GlobalVariable::NotThreadLocal, AddrSpace); + + // Handle things which are present even on external declarations. + if (D) { + // FIXME: This code is overly simple and should be merged with other global + // handling. + GV->setConstant(isTypeConstant(D->getType(), false)); + + // Set linkage and visibility in case we never see a definition. + LinkageInfo LV = D->getLinkageAndVisibility(); + if (LV.getLinkage() != ExternalLinkage) { + // Don't set internal linkage on declarations. + } else { + if (D->hasAttr<DLLImportAttr>()) + GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); + else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) + GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); + + // Set visibility on a declaration only if it's explicit. + if (LV.isVisibilityExplicit()) + GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); + } + + if (D->isThreadSpecified()) + setTLSMode(GV, *D); + } + + if (AddrSpace != Ty->getAddressSpace()) + return llvm::ConstantExpr::getBitCast(GV, Ty); + else + return GV; +} + + +llvm::GlobalVariable * +CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, + llvm::Type *Ty, + llvm::GlobalValue::LinkageTypes Linkage) { + llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); + llvm::GlobalVariable *OldGV = 0; + + + if (GV) { + // Check if the variable has the right type. + if (GV->getType()->getElementType() == Ty) + return GV; + + // Because C++ name mangling, the only way we can end up with an already + // existing global with the same name is if it has been declared extern "C". + assert(GV->isDeclaration() && "Declaration has wrong type!"); + OldGV = GV; + } + + // Create a new variable. + GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, + Linkage, 0, Name); + + if (OldGV) { + // Replace occurrences of the old variable if needed. + GV->takeName(OldGV); + + if (!OldGV->use_empty()) { + llvm::Constant *NewPtrForOldDecl = + llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); + OldGV->replaceAllUsesWith(NewPtrForOldDecl); + } + + OldGV->eraseFromParent(); + } + + return GV; +} + +/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the +/// given global variable. If Ty is non-null and if the global doesn't exist, +/// then it will be created with the specified type instead of whatever the +/// normal requested type would be. +llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, + llvm::Type *Ty) { + assert(D->hasGlobalStorage() && "Not a global variable"); + QualType ASTTy = D->getType(); + if (Ty == 0) + Ty = getTypes().ConvertTypeForMem(ASTTy); + + llvm::PointerType *PTy = + llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); + + StringRef MangledName = getMangledName(D); + return GetOrCreateLLVMGlobal(MangledName, PTy, D); +} + +/// CreateRuntimeVariable - Create a new runtime global variable with the +/// specified type and name. +llvm::Constant * +CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, + StringRef Name) { + return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, + true); +} + +void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { + assert(!D->getInit() && "Cannot emit definite definitions here!"); + + if (MayDeferGeneration(D)) { + // If we have not seen a reference to this variable yet, place it + // into the deferred declarations table to be emitted if needed + // later. + StringRef MangledName = getMangledName(D); + if (!GetGlobalValue(MangledName)) { + DeferredDecls[MangledName] = D; + return; + } + } + + // The tentative definition is the only definition. + EmitGlobalVarDefinition(D); +} + +CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { + return Context.toCharUnitsFromBits( + TheDataLayout.getTypeStoreSizeInBits(Ty)); +} + +llvm::Constant * +CodeGenModule::MaybeEmitGlobalStdInitializerListInitializer(const VarDecl *D, + const Expr *rawInit) { + ArrayRef<ExprWithCleanups::CleanupObject> cleanups; + if (const ExprWithCleanups *withCleanups = + dyn_cast<ExprWithCleanups>(rawInit)) { + cleanups = withCleanups->getObjects(); + rawInit = withCleanups->getSubExpr(); + } + + const InitListExpr *init = dyn_cast<InitListExpr>(rawInit); + if (!init || !init->initializesStdInitializerList() || + init->getNumInits() == 0) + return 0; + + ASTContext &ctx = getContext(); + unsigned numInits = init->getNumInits(); + // FIXME: This check is here because we would otherwise silently miscompile + // nested global std::initializer_lists. Better would be to have a real + // implementation. + for (unsigned i = 0; i < numInits; ++i) { + const InitListExpr *inner = dyn_cast<InitListExpr>(init->getInit(i)); + if (inner && inner->initializesStdInitializerList()) { + ErrorUnsupported(inner, "nested global std::initializer_list"); + return 0; + } + } + + // Synthesize a fake VarDecl for the array and initialize that. + QualType elementType = init->getInit(0)->getType(); + llvm::APInt numElements(ctx.getTypeSize(ctx.getSizeType()), numInits); + QualType arrayType = ctx.getConstantArrayType(elementType, numElements, + ArrayType::Normal, 0); + + IdentifierInfo *name = &ctx.Idents.get(D->getNameAsString() + "__initlist"); + TypeSourceInfo *sourceInfo = ctx.getTrivialTypeSourceInfo( + arrayType, D->getLocation()); + VarDecl *backingArray = VarDecl::Create(ctx, const_cast<DeclContext*>( + D->getDeclContext()), + D->getLocStart(), D->getLocation(), + name, arrayType, sourceInfo, + SC_Static); + + // Now clone the InitListExpr to initialize the array instead. + // Incredible hack: we want to use the existing InitListExpr here, so we need + // to tell it that it no longer initializes a std::initializer_list. + ArrayRef<Expr*> Inits(const_cast<InitListExpr*>(init)->getInits(), + init->getNumInits()); + Expr *arrayInit = new (ctx) InitListExpr(ctx, init->getLBraceLoc(), Inits, + init->getRBraceLoc()); + arrayInit->setType(arrayType); + + if (!cleanups.empty()) + arrayInit = ExprWithCleanups::Create(ctx, arrayInit, cleanups); + + backingArray->setInit(arrayInit); + + // Emit the definition of the array. + EmitGlobalVarDefinition(backingArray); + + // Inspect the initializer list to validate it and determine its type. + // FIXME: doing this every time is probably inefficient; caching would be nice + RecordDecl *record = init->getType()->castAs<RecordType>()->getDecl(); + RecordDecl::field_iterator field = record->field_begin(); + if (field == record->field_end()) { + ErrorUnsupported(D, "weird std::initializer_list"); + return 0; + } + QualType elementPtr = ctx.getPointerType(elementType.withConst()); + // Start pointer. + if (!ctx.hasSameType(field->getType(), elementPtr)) { + ErrorUnsupported(D, "weird std::initializer_list"); + return 0; + } + ++field; + if (field == record->field_end()) { + ErrorUnsupported(D, "weird std::initializer_list"); + return 0; + } + bool isStartEnd = false; + if (ctx.hasSameType(field->getType(), elementPtr)) { + // End pointer. + isStartEnd = true; + } else if(!ctx.hasSameType(field->getType(), ctx.getSizeType())) { + ErrorUnsupported(D, "weird std::initializer_list"); + return 0; + } + + // Now build an APValue representing the std::initializer_list. + APValue initListValue(APValue::UninitStruct(), 0, 2); + APValue &startField = initListValue.getStructField(0); + APValue::LValuePathEntry startOffsetPathEntry; + startOffsetPathEntry.ArrayIndex = 0; + startField = APValue(APValue::LValueBase(backingArray), + CharUnits::fromQuantity(0), + llvm::makeArrayRef(startOffsetPathEntry), + /*IsOnePastTheEnd=*/false, 0); + + if (isStartEnd) { + APValue &endField = initListValue.getStructField(1); + APValue::LValuePathEntry endOffsetPathEntry; + endOffsetPathEntry.ArrayIndex = numInits; + endField = APValue(APValue::LValueBase(backingArray), + ctx.getTypeSizeInChars(elementType) * numInits, + llvm::makeArrayRef(endOffsetPathEntry), + /*IsOnePastTheEnd=*/true, 0); + } else { + APValue &sizeField = initListValue.getStructField(1); + sizeField = APValue(llvm::APSInt(numElements)); + } + + // Emit the constant for the initializer_list. + llvm::Constant *llvmInit = + EmitConstantValueForMemory(initListValue, D->getType()); + assert(llvmInit && "failed to initialize as constant"); + return llvmInit; +} + +unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, + unsigned AddrSpace) { + if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { + if (D->hasAttr<CUDAConstantAttr>()) + AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); + else if (D->hasAttr<CUDASharedAttr>()) + AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); + else + AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); + } + + return AddrSpace; +} + +void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { + llvm::Constant *Init = 0; + QualType ASTTy = D->getType(); + CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); + bool NeedsGlobalCtor = false; + bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); + + const VarDecl *InitDecl; + const Expr *InitExpr = D->getAnyInitializer(InitDecl); + + if (!InitExpr) { + // This is a tentative definition; tentative definitions are + // implicitly initialized with { 0 }. + // + // Note that tentative definitions are only emitted at the end of + // a translation unit, so they should never have incomplete + // type. In addition, EmitTentativeDefinition makes sure that we + // never attempt to emit a tentative definition if a real one + // exists. A use may still exists, however, so we still may need + // to do a RAUW. + assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); + Init = EmitNullConstant(D->getType()); + } else { + // If this is a std::initializer_list, emit the special initializer. + Init = MaybeEmitGlobalStdInitializerListInitializer(D, InitExpr); + // An empty init list will perform zero-initialization, which happens + // to be exactly what we want. + // FIXME: It does so in a global constructor, which is *not* what we + // want. + + if (!Init) { + initializedGlobalDecl = GlobalDecl(D); + Init = EmitConstantInit(*InitDecl); + } + if (!Init) { + QualType T = InitExpr->getType(); + if (D->getType()->isReferenceType()) + T = D->getType(); + + if (getLangOpts().CPlusPlus) { + Init = EmitNullConstant(T); + NeedsGlobalCtor = true; + } else { + ErrorUnsupported(D, "static initializer"); + Init = llvm::UndefValue::get(getTypes().ConvertType(T)); + } + } else { + // We don't need an initializer, so remove the entry for the delayed + // initializer position (just in case this entry was delayed) if we + // also don't need to register a destructor. + if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) + DelayedCXXInitPosition.erase(D); + } + } + + llvm::Type* InitType = Init->getType(); + llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); + + // Strip off a bitcast if we got one back. + if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { + assert(CE->getOpcode() == llvm::Instruction::BitCast || + // all zero index gep. + CE->getOpcode() == llvm::Instruction::GetElementPtr); + Entry = CE->getOperand(0); + } + + // Entry is now either a Function or GlobalVariable. + llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); + + // We have a definition after a declaration with the wrong type. + // We must make a new GlobalVariable* and update everything that used OldGV + // (a declaration or tentative definition) with the new GlobalVariable* + // (which will be a definition). + // + // This happens if there is a prototype for a global (e.g. + // "extern int x[];") and then a definition of a different type (e.g. + // "int x[10];"). This also happens when an initializer has a different type + // from the type of the global (this happens with unions). + if (GV == 0 || + GV->getType()->getElementType() != InitType || + GV->getType()->getAddressSpace() != + GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { + + // Move the old entry aside so that we'll create a new one. + Entry->setName(StringRef()); + + // Make a new global with the correct type, this is now guaranteed to work. + GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); + + // Replace all uses of the old global with the new global + llvm::Constant *NewPtrForOldDecl = + llvm::ConstantExpr::getBitCast(GV, Entry->getType()); + Entry->replaceAllUsesWith(NewPtrForOldDecl); + + // Erase the old global, since it is no longer used. + cast<llvm::GlobalValue>(Entry)->eraseFromParent(); + } + + if (D->hasAttr<AnnotateAttr>()) + AddGlobalAnnotations(D, GV); + + GV->setInitializer(Init); + + // If it is safe to mark the global 'constant', do so now. + GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && + isTypeConstant(D->getType(), true)); + + GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); + + // Set the llvm linkage type as appropriate. + llvm::GlobalValue::LinkageTypes Linkage = + GetLLVMLinkageVarDefinition(D, GV); + GV->setLinkage(Linkage); + if (Linkage == llvm::GlobalVariable::CommonLinkage) + // common vars aren't constant even if declared const. + GV->setConstant(false); + + SetCommonAttributes(D, GV); + + // Emit the initializer function if necessary. + if (NeedsGlobalCtor || NeedsGlobalDtor) + EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); + + // If we are compiling with ASan, add metadata indicating dynamically + // initialized globals. + if (SanOpts.Address && NeedsGlobalCtor) { + llvm::Module &M = getModule(); + + llvm::NamedMDNode *DynamicInitializers = + M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); + llvm::Value *GlobalToAdd[] = { GV }; + llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); + DynamicInitializers->addOperand(ThisGlobal); + } + + // Emit global variable debug information. + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) + DI->EmitGlobalVariable(GV, D); +} + +llvm::GlobalValue::LinkageTypes +CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, + llvm::GlobalVariable *GV) { + GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); + if (Linkage == GVA_Internal) + return llvm::Function::InternalLinkage; + else if (D->hasAttr<DLLImportAttr>()) + return llvm::Function::DLLImportLinkage; + else if (D->hasAttr<DLLExportAttr>()) + return llvm::Function::DLLExportLinkage; + else if (D->hasAttr<WeakAttr>()) { + if (GV->isConstant()) + return llvm::GlobalVariable::WeakODRLinkage; + else + return llvm::GlobalVariable::WeakAnyLinkage; + } else if (Linkage == GVA_TemplateInstantiation || + Linkage == GVA_ExplicitTemplateInstantiation) + return llvm::GlobalVariable::WeakODRLinkage; + else if (!getLangOpts().CPlusPlus && + ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || + D->getAttr<CommonAttr>()) && + !D->hasExternalStorage() && !D->getInit() && + !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && + !D->getAttr<WeakImportAttr>()) { + // Thread local vars aren't considered common linkage. + return llvm::GlobalVariable::CommonLinkage; + } + return llvm::GlobalVariable::ExternalLinkage; +} + +/// Replace the uses of a function that was declared with a non-proto type. +/// We want to silently drop extra arguments from call sites +static void replaceUsesOfNonProtoConstant(llvm::Constant *old, + llvm::Function *newFn) { + // Fast path. + if (old->use_empty()) return; + + llvm::Type *newRetTy = newFn->getReturnType(); + SmallVector<llvm::Value*, 4> newArgs; + + for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); + ui != ue; ) { + llvm::Value::use_iterator use = ui++; // Increment before the use is erased. + llvm::User *user = *use; + + // Recognize and replace uses of bitcasts. Most calls to + // unprototyped functions will use bitcasts. + if (llvm::ConstantExpr *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { + if (bitcast->getOpcode() == llvm::Instruction::BitCast) + replaceUsesOfNonProtoConstant(bitcast, newFn); + continue; + } + + // Recognize calls to the function. + llvm::CallSite callSite(user); + if (!callSite) continue; + if (!callSite.isCallee(use)) continue; + + // If the return types don't match exactly, then we can't + // transform this call unless it's dead. + if (callSite->getType() != newRetTy && !callSite->use_empty()) + continue; + + // Get the call site's attribute list. + SmallVector<llvm::AttributeSet, 8> newAttrs; + llvm::AttributeSet oldAttrs = callSite.getAttributes(); + + // Collect any return attributes from the call. + if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex)) + newAttrs.push_back( + llvm::AttributeSet::get(newFn->getContext(), + oldAttrs.getRetAttributes())); + + // If the function was passed too few arguments, don't transform. + unsigned newNumArgs = newFn->arg_size(); + if (callSite.arg_size() < newNumArgs) continue; + + // If extra arguments were passed, we silently drop them. + // If any of the types mismatch, we don't transform. + unsigned argNo = 0; + bool dontTransform = false; + for (llvm::Function::arg_iterator ai = newFn->arg_begin(), + ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) { + if (callSite.getArgument(argNo)->getType() != ai->getType()) { + dontTransform = true; + break; + } + + // Add any parameter attributes. + if (oldAttrs.hasAttributes(argNo + 1)) + newAttrs. + push_back(llvm:: + AttributeSet::get(newFn->getContext(), + oldAttrs.getParamAttributes(argNo + 1))); + } + if (dontTransform) + continue; + + if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) + newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(), + oldAttrs.getFnAttributes())); + + // Okay, we can transform this. Create the new call instruction and copy + // over the required information. + newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo); + + llvm::CallSite newCall; + if (callSite.isCall()) { + newCall = llvm::CallInst::Create(newFn, newArgs, "", + callSite.getInstruction()); + } else { + llvm::InvokeInst *oldInvoke = + cast<llvm::InvokeInst>(callSite.getInstruction()); + newCall = llvm::InvokeInst::Create(newFn, + oldInvoke->getNormalDest(), + oldInvoke->getUnwindDest(), + newArgs, "", + callSite.getInstruction()); + } + newArgs.clear(); // for the next iteration + + if (!newCall->getType()->isVoidTy()) + newCall->takeName(callSite.getInstruction()); + newCall.setAttributes( + llvm::AttributeSet::get(newFn->getContext(), newAttrs)); + newCall.setCallingConv(callSite.getCallingConv()); + + // Finally, remove the old call, replacing any uses with the new one. + if (!callSite->use_empty()) + callSite->replaceAllUsesWith(newCall.getInstruction()); + + // Copy debug location attached to CI. + if (!callSite->getDebugLoc().isUnknown()) + newCall->setDebugLoc(callSite->getDebugLoc()); + callSite->eraseFromParent(); + } +} + +/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we +/// implement a function with no prototype, e.g. "int foo() {}". If there are +/// existing call uses of the old function in the module, this adjusts them to +/// call the new function directly. +/// +/// This is not just a cleanup: the always_inline pass requires direct calls to +/// functions to be able to inline them. If there is a bitcast in the way, it +/// won't inline them. Instcombine normally deletes these calls, but it isn't +/// run at -O0. +static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, + llvm::Function *NewFn) { + // If we're redefining a global as a function, don't transform it. + if (!isa<llvm::Function>(Old)) return; + + replaceUsesOfNonProtoConstant(Old, NewFn); +} + +void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { + TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); + // If we have a definition, this might be a deferred decl. If the + // instantiation is explicit, make sure we emit it at the end. + if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) + GetAddrOfGlobalVar(VD); + + EmitTopLevelDecl(VD); +} + +void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { + const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); + + // Compute the function info and LLVM type. + const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); + llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); + + // Get or create the prototype for the function. + llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); + + // Strip off a bitcast if we got one back. + if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { + assert(CE->getOpcode() == llvm::Instruction::BitCast); + Entry = CE->getOperand(0); + } + + + if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { + llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); + + // If the types mismatch then we have to rewrite the definition. + assert(OldFn->isDeclaration() && + "Shouldn't replace non-declaration"); + + // F is the Function* for the one with the wrong type, we must make a new + // Function* and update everything that used F (a declaration) with the new + // Function* (which will be a definition). + // + // This happens if there is a prototype for a function + // (e.g. "int f()") and then a definition of a different type + // (e.g. "int f(int x)"). Move the old function aside so that it + // doesn't interfere with GetAddrOfFunction. + OldFn->setName(StringRef()); + llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); + + // This might be an implementation of a function without a + // prototype, in which case, try to do special replacement of + // calls which match the new prototype. The really key thing here + // is that we also potentially drop arguments from the call site + // so as to make a direct call, which makes the inliner happier + // and suppresses a number of optimizer warnings (!) about + // dropping arguments. + if (!OldFn->use_empty()) { + ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); + OldFn->removeDeadConstantUsers(); + } + + // Replace uses of F with the Function we will endow with a body. + if (!Entry->use_empty()) { + llvm::Constant *NewPtrForOldDecl = + llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); + Entry->replaceAllUsesWith(NewPtrForOldDecl); + } + + // Ok, delete the old function now, which is dead. + OldFn->eraseFromParent(); + + Entry = NewFn; + } + + // We need to set linkage and visibility on the function before + // generating code for it because various parts of IR generation + // want to propagate this information down (e.g. to local static + // declarations). + llvm::Function *Fn = cast<llvm::Function>(Entry); + setFunctionLinkage(D, Fn); + + // FIXME: this is redundant with part of SetFunctionDefinitionAttributes + setGlobalVisibility(Fn, D); + + CodeGenFunction(*this).GenerateCode(D, Fn, FI); + + SetFunctionDefinitionAttributes(D, Fn); + SetLLVMFunctionAttributesForDefinition(D, Fn); + + if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) + AddGlobalCtor(Fn, CA->getPriority()); + if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) + AddGlobalDtor(Fn, DA->getPriority()); + if (D->hasAttr<AnnotateAttr>()) + AddGlobalAnnotations(D, Fn); +} + +void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { + const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); + const AliasAttr *AA = D->getAttr<AliasAttr>(); + assert(AA && "Not an alias?"); + + StringRef MangledName = getMangledName(GD); + + // If there is a definition in the module, then it wins over the alias. + // This is dubious, but allow it to be safe. Just ignore the alias. + llvm::GlobalValue *Entry = GetGlobalValue(MangledName); + if (Entry && !Entry->isDeclaration()) + return; + + llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); + + // Create a reference to the named value. This ensures that it is emitted + // if a deferred decl. + llvm::Constant *Aliasee; + if (isa<llvm::FunctionType>(DeclTy)) + Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, + /*ForVTable=*/false); + else + Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), + llvm::PointerType::getUnqual(DeclTy), 0); + + // Create the new alias itself, but don't set a name yet. + llvm::GlobalValue *GA = + new llvm::GlobalAlias(Aliasee->getType(), + llvm::Function::ExternalLinkage, + "", Aliasee, &getModule()); + + if (Entry) { + assert(Entry->isDeclaration()); + + // If there is a declaration in the module, then we had an extern followed + // by the alias, as in: + // extern int test6(); + // ... + // int test6() __attribute__((alias("test7"))); + // + // Remove it and replace uses of it with the alias. + GA->takeName(Entry); + + Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, + Entry->getType())); + Entry->eraseFromParent(); + } else { + GA->setName(MangledName); + } + + // Set attributes which are particular to an alias; this is a + // specialization of the attributes which may be set on a global + // variable/function. + if (D->hasAttr<DLLExportAttr>()) { + if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + // The dllexport attribute is ignored for undefined symbols. + if (FD->hasBody()) + GA->setLinkage(llvm::Function::DLLExportLinkage); + } else { + GA->setLinkage(llvm::Function::DLLExportLinkage); + } + } else if (D->hasAttr<WeakAttr>() || + D->hasAttr<WeakRefAttr>() || + D->isWeakImported()) { + GA->setLinkage(llvm::Function::WeakAnyLinkage); + } + + SetCommonAttributes(D, GA); +} + +llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, + ArrayRef<llvm::Type*> Tys) { + return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, + Tys); +} + +static llvm::StringMapEntry<llvm::Constant*> & +GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, + const StringLiteral *Literal, + bool TargetIsLSB, + bool &IsUTF16, + unsigned &StringLength) { + StringRef String = Literal->getString(); + unsigned NumBytes = String.size(); + + // Check for simple case. + if (!Literal->containsNonAsciiOrNull()) { + StringLength = NumBytes; + return Map.GetOrCreateValue(String); + } + + // Otherwise, convert the UTF8 literals into a string of shorts. + IsUTF16 = true; + + SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. + const UTF8 *FromPtr = (const UTF8 *)String.data(); + UTF16 *ToPtr = &ToBuf[0]; + + (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, + &ToPtr, ToPtr + NumBytes, + strictConversion); + + // ConvertUTF8toUTF16 returns the length in ToPtr. + StringLength = ToPtr - &ToBuf[0]; + + // Add an explicit null. + *ToPtr = 0; + return Map. + GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), + (StringLength + 1) * 2)); +} + +static llvm::StringMapEntry<llvm::Constant*> & +GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, + const StringLiteral *Literal, + unsigned &StringLength) { + StringRef String = Literal->getString(); + StringLength = String.size(); + return Map.GetOrCreateValue(String); +} + +llvm::Constant * +CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { + unsigned StringLength = 0; + bool isUTF16 = false; + llvm::StringMapEntry<llvm::Constant*> &Entry = + GetConstantCFStringEntry(CFConstantStringMap, Literal, + getDataLayout().isLittleEndian(), + isUTF16, StringLength); + + if (llvm::Constant *C = Entry.getValue()) + return C; + + llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); + llvm::Constant *Zeros[] = { Zero, Zero }; + + // If we don't already have it, get __CFConstantStringClassReference. + if (!CFConstantStringClassRef) { + llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); + Ty = llvm::ArrayType::get(Ty, 0); + llvm::Constant *GV = CreateRuntimeVariable(Ty, + "__CFConstantStringClassReference"); + // Decay array -> ptr + CFConstantStringClassRef = + llvm::ConstantExpr::getGetElementPtr(GV, Zeros); + } + + QualType CFTy = getContext().getCFConstantStringType(); + + llvm::StructType *STy = + cast<llvm::StructType>(getTypes().ConvertType(CFTy)); + + llvm::Constant *Fields[4]; + + // Class pointer. + Fields[0] = CFConstantStringClassRef; + + // Flags. + llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); + Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : + llvm::ConstantInt::get(Ty, 0x07C8); + + // String pointer. + llvm::Constant *C = 0; + if (isUTF16) { + ArrayRef<uint16_t> Arr = + llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>( + const_cast<char *>(Entry.getKey().data())), + Entry.getKey().size() / 2); + C = llvm::ConstantDataArray::get(VMContext, Arr); + } else { + C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); + } + + llvm::GlobalValue::LinkageTypes Linkage; + if (isUTF16) + // FIXME: why do utf strings get "_" labels instead of "L" labels? + Linkage = llvm::GlobalValue::InternalLinkage; + else + // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error + // when using private linkage. It is not clear if this is a bug in ld + // or a reasonable new restriction. + Linkage = llvm::GlobalValue::LinkerPrivateLinkage; + + // Note: -fwritable-strings doesn't make the backing store strings of + // CFStrings writable. (See <rdar://problem/10657500>) + llvm::GlobalVariable *GV = + new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, + Linkage, C, ".str"); + GV->setUnnamedAddr(true); + if (isUTF16) { + CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); + GV->setAlignment(Align.getQuantity()); + } else { + CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); + GV->setAlignment(Align.getQuantity()); + } + + // String. + Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); + + if (isUTF16) + // Cast the UTF16 string to the correct type. + Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); + + // String length. + Ty = getTypes().ConvertType(getContext().LongTy); + Fields[3] = llvm::ConstantInt::get(Ty, StringLength); + + // The struct. + C = llvm::ConstantStruct::get(STy, Fields); + GV = new llvm::GlobalVariable(getModule(), C->getType(), true, + llvm::GlobalVariable::PrivateLinkage, C, + "_unnamed_cfstring_"); + if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) + GV->setSection(Sect); + Entry.setValue(GV); + + return GV; +} + +static RecordDecl * +CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, + DeclContext *DC, IdentifierInfo *Id) { + SourceLocation Loc; + if (Ctx.getLangOpts().CPlusPlus) + return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); + else + return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); +} + +llvm::Constant * +CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { + unsigned StringLength = 0; + llvm::StringMapEntry<llvm::Constant*> &Entry = + GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); + + if (llvm::Constant *C = Entry.getValue()) + return C; + + llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); + llvm::Constant *Zeros[] = { Zero, Zero }; + + // If we don't already have it, get _NSConstantStringClassReference. + if (!ConstantStringClassRef) { + std::string StringClass(getLangOpts().ObjCConstantStringClass); + llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); + llvm::Constant *GV; + if (LangOpts.ObjCRuntime.isNonFragile()) { + std::string str = + StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" + : "OBJC_CLASS_$_" + StringClass; + GV = getObjCRuntime().GetClassGlobal(str); + // Make sure the result is of the correct type. + llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); + ConstantStringClassRef = + llvm::ConstantExpr::getBitCast(GV, PTy); + } else { + std::string str = + StringClass.empty() ? "_NSConstantStringClassReference" + : "_" + StringClass + "ClassReference"; + llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); + GV = CreateRuntimeVariable(PTy, str); + // Decay array -> ptr + ConstantStringClassRef = + llvm::ConstantExpr::getGetElementPtr(GV, Zeros); + } + } + + if (!NSConstantStringType) { + // Construct the type for a constant NSString. + RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, + Context.getTranslationUnitDecl(), + &Context.Idents.get("__builtin_NSString")); + D->startDefinition(); + + QualType FieldTypes[3]; + + // const int *isa; + FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); + // const char *str; + FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); + // unsigned int length; + FieldTypes[2] = Context.UnsignedIntTy; + + // Create fields + for (unsigned i = 0; i < 3; ++i) { + FieldDecl *Field = FieldDecl::Create(Context, D, + SourceLocation(), + SourceLocation(), 0, + FieldTypes[i], /*TInfo=*/0, + /*BitWidth=*/0, + /*Mutable=*/false, + ICIS_NoInit); + Field->setAccess(AS_public); + D->addDecl(Field); + } + + D->completeDefinition(); + QualType NSTy = Context.getTagDeclType(D); + NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); + } + + llvm::Constant *Fields[3]; + + // Class pointer. + Fields[0] = ConstantStringClassRef; + + // String pointer. + llvm::Constant *C = + llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); + + llvm::GlobalValue::LinkageTypes Linkage; + bool isConstant; + Linkage = llvm::GlobalValue::PrivateLinkage; + isConstant = !LangOpts.WritableStrings; + + llvm::GlobalVariable *GV = + new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, + ".str"); + GV->setUnnamedAddr(true); + CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); + GV->setAlignment(Align.getQuantity()); + Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); + + // String length. + llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); + Fields[2] = llvm::ConstantInt::get(Ty, StringLength); + + // The struct. + C = llvm::ConstantStruct::get(NSConstantStringType, Fields); + GV = new llvm::GlobalVariable(getModule(), C->getType(), true, + llvm::GlobalVariable::PrivateLinkage, C, + "_unnamed_nsstring_"); + // FIXME. Fix section. + if (const char *Sect = + LangOpts.ObjCRuntime.isNonFragile() + ? getContext().getTargetInfo().getNSStringNonFragileABISection() + : getContext().getTargetInfo().getNSStringSection()) + GV->setSection(Sect); + Entry.setValue(GV); + + return GV; +} + +QualType CodeGenModule::getObjCFastEnumerationStateType() { + if (ObjCFastEnumerationStateType.isNull()) { + RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, + Context.getTranslationUnitDecl(), + &Context.Idents.get("__objcFastEnumerationState")); + D->startDefinition(); + + QualType FieldTypes[] = { + Context.UnsignedLongTy, + Context.getPointerType(Context.getObjCIdType()), + Context.getPointerType(Context.UnsignedLongTy), + Context.getConstantArrayType(Context.UnsignedLongTy, + llvm::APInt(32, 5), ArrayType::Normal, 0) + }; + + for (size_t i = 0; i < 4; ++i) { + FieldDecl *Field = FieldDecl::Create(Context, + D, + SourceLocation(), + SourceLocation(), 0, + FieldTypes[i], /*TInfo=*/0, + /*BitWidth=*/0, + /*Mutable=*/false, + ICIS_NoInit); + Field->setAccess(AS_public); + D->addDecl(Field); + } + + D->completeDefinition(); + ObjCFastEnumerationStateType = Context.getTagDeclType(D); + } + + return ObjCFastEnumerationStateType; +} + +llvm::Constant * +CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { + assert(!E->getType()->isPointerType() && "Strings are always arrays"); + + // Don't emit it as the address of the string, emit the string data itself + // as an inline array. + if (E->getCharByteWidth() == 1) { + SmallString<64> Str(E->getString()); + + // Resize the string to the right size, which is indicated by its type. + const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); + Str.resize(CAT->getSize().getZExtValue()); + return llvm::ConstantDataArray::getString(VMContext, Str, false); + } + + llvm::ArrayType *AType = + cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); + llvm::Type *ElemTy = AType->getElementType(); + unsigned NumElements = AType->getNumElements(); + + // Wide strings have either 2-byte or 4-byte elements. + if (ElemTy->getPrimitiveSizeInBits() == 16) { + SmallVector<uint16_t, 32> Elements; + Elements.reserve(NumElements); + + for(unsigned i = 0, e = E->getLength(); i != e; ++i) + Elements.push_back(E->getCodeUnit(i)); + Elements.resize(NumElements); + return llvm::ConstantDataArray::get(VMContext, Elements); + } + + assert(ElemTy->getPrimitiveSizeInBits() == 32); + SmallVector<uint32_t, 32> Elements; + Elements.reserve(NumElements); + + for(unsigned i = 0, e = E->getLength(); i != e; ++i) + Elements.push_back(E->getCodeUnit(i)); + Elements.resize(NumElements); + return llvm::ConstantDataArray::get(VMContext, Elements); +} + +/// GetAddrOfConstantStringFromLiteral - Return a pointer to a +/// constant array for the given string literal. +llvm::Constant * +CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { + CharUnits Align = getContext().getTypeAlignInChars(S->getType()); + if (S->isAscii() || S->isUTF8()) { + SmallString<64> Str(S->getString()); + + // Resize the string to the right size, which is indicated by its type. + const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); + Str.resize(CAT->getSize().getZExtValue()); + return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); + } + + // FIXME: the following does not memoize wide strings. + llvm::Constant *C = GetConstantArrayFromStringLiteral(S); + llvm::GlobalVariable *GV = + new llvm::GlobalVariable(getModule(),C->getType(), + !LangOpts.WritableStrings, + llvm::GlobalValue::PrivateLinkage, + C,".str"); + + GV->setAlignment(Align.getQuantity()); + GV->setUnnamedAddr(true); + return GV; +} + +/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant +/// array for the given ObjCEncodeExpr node. +llvm::Constant * +CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { + std::string Str; + getContext().getObjCEncodingForType(E->getEncodedType(), Str); + + return GetAddrOfConstantCString(Str); +} + + +/// GenerateWritableString -- Creates storage for a string literal. +static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, + bool constant, + CodeGenModule &CGM, + const char *GlobalName, + unsigned Alignment) { + // Create Constant for this string literal. Don't add a '\0'. + llvm::Constant *C = + llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); + + // Create a global variable for this string + llvm::GlobalVariable *GV = + new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, + llvm::GlobalValue::PrivateLinkage, + C, GlobalName); + GV->setAlignment(Alignment); + GV->setUnnamedAddr(true); + return GV; +} + +/// GetAddrOfConstantString - Returns a pointer to a character array +/// containing the literal. This contents are exactly that of the +/// given string, i.e. it will not be null terminated automatically; +/// see GetAddrOfConstantCString. Note that whether the result is +/// actually a pointer to an LLVM constant depends on +/// Feature.WriteableStrings. +/// +/// The result has pointer to array type. +llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, + const char *GlobalName, + unsigned Alignment) { + // Get the default prefix if a name wasn't specified. + if (!GlobalName) + GlobalName = ".str"; + + // Don't share any string literals if strings aren't constant. + if (LangOpts.WritableStrings) + return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); + + llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = + ConstantStringMap.GetOrCreateValue(Str); + + if (llvm::GlobalVariable *GV = Entry.getValue()) { + if (Alignment > GV->getAlignment()) { + GV->setAlignment(Alignment); + } + return GV; + } + + // Create a global variable for this. + llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, + Alignment); + Entry.setValue(GV); + return GV; +} + +/// GetAddrOfConstantCString - Returns a pointer to a character +/// array containing the literal and a terminating '\0' +/// character. The result has pointer to array type. +llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, + const char *GlobalName, + unsigned Alignment) { + StringRef StrWithNull(Str.c_str(), Str.size() + 1); + return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); +} + +/// EmitObjCPropertyImplementations - Emit information for synthesized +/// properties for an implementation. +void CodeGenModule::EmitObjCPropertyImplementations(const + ObjCImplementationDecl *D) { + for (ObjCImplementationDecl::propimpl_iterator + i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { + ObjCPropertyImplDecl *PID = *i; + + // Dynamic is just for type-checking. + if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { + ObjCPropertyDecl *PD = PID->getPropertyDecl(); + + // Determine which methods need to be implemented, some may have + // been overridden. Note that ::isPropertyAccessor is not the method + // we want, that just indicates if the decl came from a + // property. What we want to know is if the method is defined in + // this implementation. + if (!D->getInstanceMethod(PD->getGetterName())) + CodeGenFunction(*this).GenerateObjCGetter( + const_cast<ObjCImplementationDecl *>(D), PID); + if (!PD->isReadOnly() && + !D->getInstanceMethod(PD->getSetterName())) + CodeGenFunction(*this).GenerateObjCSetter( + const_cast<ObjCImplementationDecl *>(D), PID); + } + } +} + +static bool needsDestructMethod(ObjCImplementationDecl *impl) { + const ObjCInterfaceDecl *iface = impl->getClassInterface(); + for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); + ivar; ivar = ivar->getNextIvar()) + if (ivar->getType().isDestructedType()) + return true; + + return false; +} + +/// EmitObjCIvarInitializations - Emit information for ivar initialization +/// for an implementation. +void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { + // We might need a .cxx_destruct even if we don't have any ivar initializers. + if (needsDestructMethod(D)) { + IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); + Selector cxxSelector = getContext().Selectors.getSelector(0, &II); + ObjCMethodDecl *DTORMethod = + ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), + cxxSelector, getContext().VoidTy, 0, D, + /*isInstance=*/true, /*isVariadic=*/false, + /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, + /*isDefined=*/false, ObjCMethodDecl::Required); + D->addInstanceMethod(DTORMethod); + CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); + D->setHasDestructors(true); + } + + // If the implementation doesn't have any ivar initializers, we don't need + // a .cxx_construct. + if (D->getNumIvarInitializers() == 0) + return; + + IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); + Selector cxxSelector = getContext().Selectors.getSelector(0, &II); + // The constructor returns 'self'. + ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), + D->getLocation(), + D->getLocation(), + cxxSelector, + getContext().getObjCIdType(), 0, + D, /*isInstance=*/true, + /*isVariadic=*/false, + /*isPropertyAccessor=*/true, + /*isImplicitlyDeclared=*/true, + /*isDefined=*/false, + ObjCMethodDecl::Required); + D->addInstanceMethod(CTORMethod); + CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); + D->setHasNonZeroConstructors(true); +} + +/// EmitNamespace - Emit all declarations in a namespace. +void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { + for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); + I != E; ++I) + EmitTopLevelDecl(*I); +} + +// EmitLinkageSpec - Emit all declarations in a linkage spec. +void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { + if (LSD->getLanguage() != LinkageSpecDecl::lang_c && + LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { + ErrorUnsupported(LSD, "linkage spec"); + return; + } + + for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); + I != E; ++I) { + // Meta-data for ObjC class includes references to implemented methods. + // Generate class's method definitions first. + if (ObjCImplDecl *OID = dyn_cast<ObjCImplDecl>(*I)) { + for (ObjCContainerDecl::method_iterator M = OID->meth_begin(), + MEnd = OID->meth_end(); + M != MEnd; ++M) + EmitTopLevelDecl(*M); + } + EmitTopLevelDecl(*I); + } +} + +/// EmitTopLevelDecl - Emit code for a single top level declaration. +void CodeGenModule::EmitTopLevelDecl(Decl *D) { + // If an error has occurred, stop code generation, but continue + // parsing and semantic analysis (to ensure all warnings and errors + // are emitted). + if (Diags.hasErrorOccurred()) + return; + + // Ignore dependent declarations. + if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) + return; + + switch (D->getKind()) { + case Decl::CXXConversion: + case Decl::CXXMethod: + case Decl::Function: + // Skip function templates + if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || + cast<FunctionDecl>(D)->isLateTemplateParsed()) + return; + + EmitGlobal(cast<FunctionDecl>(D)); + break; + + case Decl::Var: + EmitGlobal(cast<VarDecl>(D)); + break; + + // Indirect fields from global anonymous structs and unions can be + // ignored; only the actual variable requires IR gen support. + case Decl::IndirectField: + break; + + // C++ Decls + case Decl::Namespace: + EmitNamespace(cast<NamespaceDecl>(D)); + break; + // No code generation needed. + case Decl::UsingShadow: + case Decl::Using: + case Decl::UsingDirective: + case Decl::ClassTemplate: + case Decl::FunctionTemplate: + case Decl::TypeAliasTemplate: + case Decl::NamespaceAlias: + case Decl::Block: + case Decl::Empty: + break; + case Decl::CXXConstructor: + // Skip function templates + if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || + cast<FunctionDecl>(D)->isLateTemplateParsed()) + return; + + EmitCXXConstructors(cast<CXXConstructorDecl>(D)); + break; + case Decl::CXXDestructor: + if (cast<FunctionDecl>(D)->isLateTemplateParsed()) + return; + EmitCXXDestructors(cast<CXXDestructorDecl>(D)); + break; + + case Decl::StaticAssert: + // Nothing to do. + break; + + // Objective-C Decls + + // Forward declarations, no (immediate) code generation. + case Decl::ObjCInterface: + case Decl::ObjCCategory: + break; + + case Decl::ObjCProtocol: { + ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); + if (Proto->isThisDeclarationADefinition()) + ObjCRuntime->GenerateProtocol(Proto); + break; + } + + case Decl::ObjCCategoryImpl: + // Categories have properties but don't support synthesize so we + // can ignore them here. + ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); + break; + + case Decl::ObjCImplementation: { + ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); + EmitObjCPropertyImplementations(OMD); + EmitObjCIvarInitializations(OMD); + ObjCRuntime->GenerateClass(OMD); + // Emit global variable debug information. + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) + DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( + OMD->getClassInterface()), OMD->getLocation()); + break; + } + case Decl::ObjCMethod: { + ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); + // If this is not a prototype, emit the body. + if (OMD->getBody()) + CodeGenFunction(*this).GenerateObjCMethod(OMD); + break; + } + case Decl::ObjCCompatibleAlias: + ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); + break; + + case Decl::LinkageSpec: + EmitLinkageSpec(cast<LinkageSpecDecl>(D)); + break; + + case Decl::FileScopeAsm: { + FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); + StringRef AsmString = AD->getAsmString()->getString(); + + const std::string &S = getModule().getModuleInlineAsm(); + if (S.empty()) + getModule().setModuleInlineAsm(AsmString); + else if (S.end()[-1] == '\n') + getModule().setModuleInlineAsm(S + AsmString.str()); + else + getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); + break; + } + + case Decl::Import: { + ImportDecl *Import = cast<ImportDecl>(D); + + // Ignore import declarations that come from imported modules. + if (clang::Module *Owner = Import->getOwningModule()) { + if (getLangOpts().CurrentModule.empty() || + Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule) + break; + } + + ImportedModules.insert(Import->getImportedModule()); + break; + } + + default: + // Make sure we handled everything we should, every other kind is a + // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind + // function. Need to recode Decl::Kind to do that easily. + assert(isa<TypeDecl>(D) && "Unsupported decl kind"); + } +} + +/// Turns the given pointer into a constant. +static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, + const void *Ptr) { + uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); + llvm::Type *i64 = llvm::Type::getInt64Ty(Context); + return llvm::ConstantInt::get(i64, PtrInt); +} + +static void EmitGlobalDeclMetadata(CodeGenModule &CGM, + llvm::NamedMDNode *&GlobalMetadata, + GlobalDecl D, + llvm::GlobalValue *Addr) { + if (!GlobalMetadata) + GlobalMetadata = + CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); + + // TODO: should we report variant information for ctors/dtors? + llvm::Value *Ops[] = { + Addr, + GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) + }; + GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); +} + +/// Emits metadata nodes associating all the global values in the +/// current module with the Decls they came from. This is useful for +/// projects using IR gen as a subroutine. +/// +/// Since there's currently no way to associate an MDNode directly +/// with an llvm::GlobalValue, we create a global named metadata +/// with the name 'clang.global.decl.ptrs'. +void CodeGenModule::EmitDeclMetadata() { + llvm::NamedMDNode *GlobalMetadata = 0; + + // StaticLocalDeclMap + for (llvm::DenseMap<GlobalDecl,StringRef>::iterator + I = MangledDeclNames.begin(), E = MangledDeclNames.end(); + I != E; ++I) { + llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); + EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); + } +} + +/// Emits metadata nodes for all the local variables in the current +/// function. +void CodeGenFunction::EmitDeclMetadata() { + if (LocalDeclMap.empty()) return; + + llvm::LLVMContext &Context = getLLVMContext(); + + // Find the unique metadata ID for this name. + unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); + + llvm::NamedMDNode *GlobalMetadata = 0; + + for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator + I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { + const Decl *D = I->first; + llvm::Value *Addr = I->second; + + if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { + llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); + Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); + } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { + GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); + EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); + } + } +} + +void CodeGenModule::EmitCoverageFile() { + if (!getCodeGenOpts().CoverageFile.empty()) { + if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { + llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); + llvm::LLVMContext &Ctx = TheModule.getContext(); + llvm::MDString *CoverageFile = + llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); + for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { + llvm::MDNode *CU = CUNode->getOperand(i); + llvm::Value *node[] = { CoverageFile, CU }; + llvm::MDNode *N = llvm::MDNode::get(Ctx, node); + GCov->addOperand(N); + } + } + } +} + +llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, + QualType GuidType) { + // Sema has checked that all uuid strings are of the form + // "12345678-1234-1234-1234-1234567890ab". + assert(Uuid.size() == 36); + const char *Uuidstr = Uuid.data(); + for (int i = 0; i < 36; ++i) { + if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuidstr[i] == '-'); + else assert(isHexDigit(Uuidstr[i])); + } + + llvm::APInt Field0(32, StringRef(Uuidstr , 8), 16); + llvm::APInt Field1(16, StringRef(Uuidstr + 9, 4), 16); + llvm::APInt Field2(16, StringRef(Uuidstr + 14, 4), 16); + static const int Field3ValueOffsets[] = { 19, 21, 24, 26, 28, 30, 32, 34 }; + + APValue InitStruct(APValue::UninitStruct(), /*NumBases=*/0, /*NumFields=*/4); + InitStruct.getStructField(0) = APValue(llvm::APSInt(Field0)); + InitStruct.getStructField(1) = APValue(llvm::APSInt(Field1)); + InitStruct.getStructField(2) = APValue(llvm::APSInt(Field2)); + APValue& Arr = InitStruct.getStructField(3); + Arr = APValue(APValue::UninitArray(), 8, 8); + for (int t = 0; t < 8; ++t) + Arr.getArrayInitializedElt(t) = APValue(llvm::APSInt( + llvm::APInt(8, StringRef(Uuidstr + Field3ValueOffsets[t], 2), 16))); + + return EmitConstantValue(InitStruct, GuidType); +} |