diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp | 3983 |
1 files changed, 3983 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..173b0dcba1c2 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CodeGenModule.cpp @@ -0,0 +1,3983 @@ +//===--- 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 "CGBlocks.h" +#include "CGCUDARuntime.h" +#include "CGCXXABI.h" +#include "CGCall.h" +#include "CGDebugInfo.h" +#include "CGObjCRuntime.h" +#include "CGOpenCLRuntime.h" +#include "CGOpenMPRuntime.h" +#include "CodeGenFunction.h" +#include "CodeGenPGO.h" +#include "CodeGenTBAA.h" +#include "CoverageMappingGen.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/Version.h" +#include "clang/Frontend/CodeGenOptions.h" +#include "clang/Sema/SemaDiagnostic.h" +#include "llvm/ADT/APSInt.h" +#include "llvm/ADT/Triple.h" +#include "llvm/IR/CallSite.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/ProfileData/InstrProfReader.h" +#include "llvm/Support/ConvertUTF.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/MD5.h" + +using namespace clang; +using namespace CodeGen; + +static const char AnnotationSection[] = "llvm.metadata"; + +static CGCXXABI *createCXXABI(CodeGenModule &CGM) { + switch (CGM.getTarget().getCXXABI().getKind()) { + case TargetCXXABI::GenericAArch64: + case TargetCXXABI::GenericARM: + case TargetCXXABI::iOS: + case TargetCXXABI::iOS64: + case TargetCXXABI::WatchOS: + case TargetCXXABI::GenericMIPS: + case TargetCXXABI::GenericItanium: + case TargetCXXABI::WebAssembly: + return CreateItaniumCXXABI(CGM); + case TargetCXXABI::Microsoft: + return CreateMicrosoftCXXABI(CGM); + } + + llvm_unreachable("invalid C++ ABI kind"); +} + +CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO, + const PreprocessorOptions &PPO, + const CodeGenOptions &CGO, llvm::Module &M, + DiagnosticsEngine &diags, + CoverageSourceInfo *CoverageInfo) + : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO), + PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags), + Target(C.getTargetInfo()), ABI(createCXXABI(*this)), + VMContext(M.getContext()), TBAA(nullptr), TheTargetCodeGenInfo(nullptr), + Types(*this), VTables(*this), ObjCRuntime(nullptr), + OpenCLRuntime(nullptr), OpenMPRuntime(nullptr), CUDARuntime(nullptr), + DebugInfo(nullptr), ObjCData(nullptr), + NoObjCARCExceptionsMetadata(nullptr), PGOReader(nullptr), + CFConstantStringClassRef(nullptr), ConstantStringClassRef(nullptr), + NSConstantStringType(nullptr), NSConcreteGlobalBlock(nullptr), + NSConcreteStackBlock(nullptr), BlockObjectAssign(nullptr), + BlockObjectDispose(nullptr), BlockDescriptorType(nullptr), + GenericBlockLiteralType(nullptr), LifetimeStartFn(nullptr), + LifetimeEndFn(nullptr), SanitizerMD(new SanitizerMetadata(*this)) { + + // 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(); + IntAlignInBytes = + C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).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(); + BuiltinCC = getTargetCodeGenInfo().getABIInfo().getBuiltinCC(); + + if (LangOpts.ObjC1) + createObjCRuntime(); + if (LangOpts.OpenCL) + createOpenCLRuntime(); + if (LangOpts.OpenMP) + createOpenMPRuntime(); + if (LangOpts.CUDA) + createCUDARuntime(); + + // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0. + if (LangOpts.Sanitize.has(SanitizerKind::Thread) || + (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)) + TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(), + getCXXABI().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().ObjC1) + ObjCData = new ObjCEntrypoints(); + + if (!CodeGenOpts.InstrProfileInput.empty()) { + auto ReaderOrErr = + llvm::IndexedInstrProfReader::create(CodeGenOpts.InstrProfileInput); + if (std::error_code EC = ReaderOrErr.getError()) { + unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, + "Could not read profile %0: %1"); + getDiags().Report(DiagID) << CodeGenOpts.InstrProfileInput + << EC.message(); + } else + PGOReader = std::move(ReaderOrErr.get()); + } + + // If coverage mapping generation is enabled, create the + // CoverageMappingModuleGen object. + if (CodeGenOpts.CoverageMapping) + CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo)); +} + +CodeGenModule::~CodeGenModule() { + delete ObjCRuntime; + delete OpenCLRuntime; + delete OpenMPRuntime; + delete CUDARuntime; + delete TheTargetCodeGenInfo; + delete TBAA; + delete DebugInfo; + delete ObjCData; +} + +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: + case ObjCRuntime::WatchOS: + ObjCRuntime = CreateMacObjCRuntime(*this); + return; + } + llvm_unreachable("bad runtime kind"); +} + +void CodeGenModule::createOpenCLRuntime() { + OpenCLRuntime = new CGOpenCLRuntime(*this); +} + +void CodeGenModule::createOpenMPRuntime() { + OpenMPRuntime = new CGOpenMPRuntime(*this); +} + +void CodeGenModule::createCUDARuntime() { + CUDARuntime = CreateNVCUDARuntime(*this); +} + +void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) { + Replacements[Name] = C; +} + +void CodeGenModule::applyReplacements() { + for (auto &I : Replacements) { + StringRef MangledName = I.first(); + llvm::Constant *Replacement = I.second; + llvm::GlobalValue *Entry = GetGlobalValue(MangledName); + if (!Entry) + continue; + auto *OldF = cast<llvm::Function>(Entry); + auto *NewF = dyn_cast<llvm::Function>(Replacement); + if (!NewF) { + if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) { + NewF = dyn_cast<llvm::Function>(Alias->getAliasee()); + } else { + auto *CE = cast<llvm::ConstantExpr>(Replacement); + assert(CE->getOpcode() == llvm::Instruction::BitCast || + CE->getOpcode() == llvm::Instruction::GetElementPtr); + NewF = dyn_cast<llvm::Function>(CE->getOperand(0)); + } + } + + // Replace old with new, but keep the old order. + OldF->replaceAllUsesWith(Replacement); + if (NewF) { + NewF->removeFromParent(); + OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(), + NewF); + } + OldF->eraseFromParent(); + } +} + +void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) { + GlobalValReplacements.push_back(std::make_pair(GV, C)); +} + +void CodeGenModule::applyGlobalValReplacements() { + for (auto &I : GlobalValReplacements) { + llvm::GlobalValue *GV = I.first; + llvm::Constant *C = I.second; + + GV->replaceAllUsesWith(C); + GV->eraseFromParent(); + } +} + +// This is only used in aliases that we created and we know they have a +// linear structure. +static const llvm::GlobalObject *getAliasedGlobal(const llvm::GlobalAlias &GA) { + llvm::SmallPtrSet<const llvm::GlobalAlias*, 4> Visited; + const llvm::Constant *C = &GA; + for (;;) { + C = C->stripPointerCasts(); + if (auto *GO = dyn_cast<llvm::GlobalObject>(C)) + return GO; + // stripPointerCasts will not walk over weak aliases. + auto *GA2 = dyn_cast<llvm::GlobalAlias>(C); + if (!GA2) + return nullptr; + if (!Visited.insert(GA2).second) + return nullptr; + C = GA2->getAliasee(); + } +} + +void CodeGenModule::checkAliases() { + // Check if the constructed aliases are well formed. It is really unfortunate + // that we have to do this in CodeGen, but we only construct mangled names + // and aliases during codegen. + bool Error = false; + DiagnosticsEngine &Diags = getDiags(); + for (const GlobalDecl &GD : Aliases) { + const auto *D = cast<ValueDecl>(GD.getDecl()); + const AliasAttr *AA = D->getAttr<AliasAttr>(); + StringRef MangledName = getMangledName(GD); + llvm::GlobalValue *Entry = GetGlobalValue(MangledName); + auto *Alias = cast<llvm::GlobalAlias>(Entry); + const llvm::GlobalValue *GV = getAliasedGlobal(*Alias); + if (!GV) { + Error = true; + Diags.Report(AA->getLocation(), diag::err_cyclic_alias); + } else if (GV->isDeclaration()) { + Error = true; + Diags.Report(AA->getLocation(), diag::err_alias_to_undefined); + } + + llvm::Constant *Aliasee = Alias->getAliasee(); + llvm::GlobalValue *AliaseeGV; + if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee)) + AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0)); + else + AliaseeGV = cast<llvm::GlobalValue>(Aliasee); + + if (const SectionAttr *SA = D->getAttr<SectionAttr>()) { + StringRef AliasSection = SA->getName(); + if (AliasSection != AliaseeGV->getSection()) + Diags.Report(SA->getLocation(), diag::warn_alias_with_section) + << AliasSection; + } + + // We have to handle alias to weak aliases in here. LLVM itself disallows + // this since the object semantics would not match the IL one. For + // compatibility with gcc we implement it by just pointing the alias + // to its aliasee's aliasee. We also warn, since the user is probably + // expecting the link to be weak. + if (auto GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) { + if (GA->mayBeOverridden()) { + Diags.Report(AA->getLocation(), diag::warn_alias_to_weak_alias) + << GV->getName() << GA->getName(); + Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast( + GA->getAliasee(), Alias->getType()); + Alias->setAliasee(Aliasee); + } + } + } + if (!Error) + return; + + for (const GlobalDecl &GD : Aliases) { + StringRef MangledName = getMangledName(GD); + llvm::GlobalValue *Entry = GetGlobalValue(MangledName); + auto *Alias = cast<llvm::GlobalAlias>(Entry); + Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType())); + Alias->eraseFromParent(); + } +} + +void CodeGenModule::clear() { + DeferredDeclsToEmit.clear(); + if (OpenMPRuntime) + OpenMPRuntime->clear(); +} + +void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags, + StringRef MainFile) { + if (!hasDiagnostics()) + return; + if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) { + if (MainFile.empty()) + MainFile = "<stdin>"; + Diags.Report(diag::warn_profile_data_unprofiled) << MainFile; + } else + Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Missing + << Mismatched; +} + +void CodeGenModule::Release() { + EmitDeferred(); + applyGlobalValReplacements(); + applyReplacements(); + checkAliases(); + EmitCXXGlobalInitFunc(); + EmitCXXGlobalDtorFunc(); + EmitCXXThreadLocalInitFunc(); + if (ObjCRuntime) + if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) + AddGlobalCtor(ObjCInitFunction); + if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice && + CUDARuntime) { + if (llvm::Function *CudaCtorFunction = CUDARuntime->makeModuleCtorFunction()) + AddGlobalCtor(CudaCtorFunction); + if (llvm::Function *CudaDtorFunction = CUDARuntime->makeModuleDtorFunction()) + AddGlobalDtor(CudaDtorFunction); + } + if (PGOReader) { + getModule().setMaximumFunctionCount(PGOReader->getMaximumFunctionCount()); + if (PGOStats.hasDiagnostics()) + PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName); + } + EmitCtorList(GlobalCtors, "llvm.global_ctors"); + EmitCtorList(GlobalDtors, "llvm.global_dtors"); + EmitGlobalAnnotations(); + EmitStaticExternCAliases(); + EmitDeferredUnusedCoverageMappings(); + if (CoverageMapping) + CoverageMapping->emit(); + emitLLVMUsed(); + + if (CodeGenOpts.Autolink && + (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) { + EmitModuleLinkOptions(); + } + if (CodeGenOpts.DwarfVersion) { + // We actually want the latest version when there are conflicts. + // We can change from Warning to Latest if such mode is supported. + getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version", + CodeGenOpts.DwarfVersion); + } + if (CodeGenOpts.EmitCodeView) { + // Indicate that we want CodeView in the metadata. + getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1); + } + if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) { + // We don't support LTO with 2 with different StrictVTablePointers + // FIXME: we could support it by stripping all the information introduced + // by StrictVTablePointers. + + getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1); + + llvm::Metadata *Ops[2] = { + llvm::MDString::get(VMContext, "StrictVTablePointers"), + llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( + llvm::Type::getInt32Ty(VMContext), 1))}; + + getModule().addModuleFlag(llvm::Module::Require, + "StrictVTablePointersRequirement", + llvm::MDNode::get(VMContext, Ops)); + } + if (DebugInfo) + // We support a single version in the linked module. The LLVM + // parser will drop debug info with a different version number + // (and warn about it, too). + getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version", + llvm::DEBUG_METADATA_VERSION); + + // We need to record the widths of enums and wchar_t, so that we can generate + // the correct build attributes in the ARM backend. + llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch(); + if ( Arch == llvm::Triple::arm + || Arch == llvm::Triple::armeb + || Arch == llvm::Triple::thumb + || Arch == llvm::Triple::thumbeb) { + // Width of wchar_t in bytes + uint64_t WCharWidth = + Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity(); + getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth); + + // The minimum width of an enum in bytes + uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4; + getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth); + } + + if (CodeGenOpts.SanitizeCfiCrossDso) { + // Indicate that we want cross-DSO control flow integrity checks. + getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1); + } + + if (uint32_t PLevel = Context.getLangOpts().PICLevel) { + llvm::PICLevel::Level PL = llvm::PICLevel::Default; + switch (PLevel) { + case 0: break; + case 1: PL = llvm::PICLevel::Small; break; + case 2: PL = llvm::PICLevel::Large; break; + default: llvm_unreachable("Invalid PIC Level"); + } + + getModule().setPICLevel(PL); + } + + SimplifyPersonality(); + + if (getCodeGenOpts().EmitDeclMetadata) + EmitDeclMetadata(); + + if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) + EmitCoverageFile(); + + if (DebugInfo) + DebugInfo->finalize(); + + EmitVersionIdentMetadata(); + + EmitTargetMetadata(); +} + +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 nullptr; + return TBAA->getTBAAInfo(QTy); +} + +llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { + if (!TBAA) + return nullptr; + return TBAA->getTBAAInfoForVTablePtr(); +} + +llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { + if (!TBAA) + return nullptr; + return TBAA->getTBAAStructInfo(QTy); +} + +llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, + llvm::MDNode *AccessN, + uint64_t O) { + if (!TBAA) + return nullptr; + return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); +} + +/// Decorate the instruction with a TBAA tag. For both scalar TBAA +/// and struct-path aware TBAA, the tag has the same format: +/// base type, access type and offset. +/// When ConvertTypeToTag is true, we create a tag based on the scalar type. +void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst, + llvm::MDNode *TBAAInfo, + bool ConvertTypeToTag) { + if (ConvertTypeToTag && TBAA) + Inst->setMetadata(llvm::LLVMContext::MD_tbaa, + TBAA->getTBAAScalarTagInfo(TBAAInfo)); + else + Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); +} + +void CodeGenModule::DecorateInstructionWithInvariantGroup( + llvm::Instruction *I, const CXXRecordDecl *RD) { + llvm::Metadata *MD = CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0)); + auto *MetaDataNode = dyn_cast<llvm::MDNode>(MD); + // Check if we have to wrap MDString in MDNode. + if (!MetaDataNode) + MetaDataNode = llvm::MDNode::get(getLLVMContext(), MD); + I->setMetadata(llvm::LLVMContext::MD_invariant_group, MetaDataNode); +} + +void CodeGenModule::Error(SourceLocation loc, StringRef message) { + unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0"); + getDiags().Report(Context.getFullLoc(loc), diagID) << message; +} + +/// ErrorUnsupported - Print out an error that codegen doesn't support the +/// specified stmt yet. +void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) { + 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) { + 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::GlobalValue *GV, const VarDecl &D) const { + assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); + + llvm::GlobalValue::ThreadLocalMode TLM; + TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); + + // Override the TLS model if it is explicitly specified. + if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) { + TLM = GetLLVMTLSModel(Attr->getModel()); + } + + GV->setThreadLocalMode(TLM); +} + +StringRef CodeGenModule::getMangledName(GlobalDecl GD) { + StringRef &FoundStr = MangledDeclNames[GD.getCanonicalDecl()]; + if (!FoundStr.empty()) + return FoundStr; + + const auto *ND = cast<NamedDecl>(GD.getDecl()); + SmallString<256> Buffer; + StringRef Str; + if (getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { + llvm::raw_svector_ostream Out(Buffer); + if (const auto *D = dyn_cast<CXXConstructorDecl>(ND)) + getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); + else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND)) + getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); + else + getCXXABI().getMangleContext().mangleName(ND, Out); + Str = Out.str(); + } else { + IdentifierInfo *II = ND->getIdentifier(); + assert(II && "Attempt to mangle unnamed decl."); + Str = II->getName(); + } + + // Keep the first result in the case of a mangling collision. + auto Result = Manglings.insert(std::make_pair(Str, GD)); + return FoundStr = Result.first->first(); +} + +StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD, + const BlockDecl *BD) { + MangleContext &MangleCtx = getCXXABI().getMangleContext(); + const Decl *D = GD.getDecl(); + + SmallString<256> Buffer; + llvm::raw_svector_ostream Out(Buffer); + if (!D) + MangleCtx.mangleGlobalBlock(BD, + dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); + else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D)) + MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); + else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D)) + MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); + else + MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); + + auto Result = Manglings.insert(std::make_pair(Out.str(), BD)); + return Result.first->first(); +} + +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, + llvm::Constant *AssociatedData) { + // FIXME: Type coercion of void()* types. + GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData)); +} + +/// 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(Structor(Priority, Dtor, nullptr)); +} + +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 ()*, i8* }. + llvm::StructType *CtorStructTy = llvm::StructType::get( + Int32Ty, llvm::PointerType::getUnqual(CtorFTy), VoidPtrTy, nullptr); + + // Construct the constructor and destructor arrays. + SmallVector<llvm::Constant *, 8> Ctors; + for (const auto &I : Fns) { + llvm::Constant *S[] = { + llvm::ConstantInt::get(Int32Ty, I.Priority, false), + llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy), + (I.AssociatedData + ? llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy) + : llvm::Constant::getNullValue(VoidPtrTy))}; + 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(GlobalDecl GD) { + const auto *D = cast<FunctionDecl>(GD.getDecl()); + + GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); + + if (isa<CXXDestructorDecl>(D) && + getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), + GD.getDtorType())) { + // Destructor variants in the Microsoft C++ ABI are always internal or + // linkonce_odr thunks emitted on an as-needed basis. + return Linkage == GVA_Internal ? llvm::GlobalValue::InternalLinkage + : llvm::GlobalValue::LinkOnceODRLinkage; + } + + return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false); +} + +void CodeGenModule::setFunctionDLLStorageClass(GlobalDecl GD, llvm::Function *F) { + const auto *FD = cast<FunctionDecl>(GD.getDecl()); + + if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(FD)) { + if (getCXXABI().useThunkForDtorVariant(Dtor, GD.getDtorType())) { + // Don't dllexport/import destructor thunks. + F->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass); + return; + } + } + + if (FD->hasAttr<DLLImportAttr>()) + F->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass); + else if (FD->hasAttr<DLLExportAttr>()) + F->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass); + else + F->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass); +} + +llvm::ConstantInt * +CodeGenModule::CreateCfiIdForTypeMetadata(llvm::Metadata *MD) { + llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD); + if (!MDS) return nullptr; + + llvm::MD5 md5; + llvm::MD5::MD5Result result; + md5.update(MDS->getString()); + md5.final(result); + uint64_t id = 0; + for (int i = 0; i < 8; ++i) + id |= static_cast<uint64_t>(result[i]) << (i * 8); + return llvm::ConstantInt::get(Int64Ty, id); +} + +void CodeGenModule::setFunctionDefinitionAttributes(const FunctionDecl *D, + llvm::Function *F) { + setNonAliasAttributes(D, F); +} + +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) { + llvm::AttrBuilder B; + + if (CodeGenOpts.UnwindTables) + B.addAttribute(llvm::Attribute::UWTable); + + if (!hasUnwindExceptions(LangOpts)) + B.addAttribute(llvm::Attribute::NoUnwind); + + if (LangOpts.getStackProtector() == LangOptions::SSPOn) + B.addAttribute(llvm::Attribute::StackProtect); + else if (LangOpts.getStackProtector() == LangOptions::SSPStrong) + B.addAttribute(llvm::Attribute::StackProtectStrong); + else if (LangOpts.getStackProtector() == LangOptions::SSPReq) + B.addAttribute(llvm::Attribute::StackProtectReq); + + if (!D) { + F->addAttributes(llvm::AttributeSet::FunctionIndex, + llvm::AttributeSet::get( + F->getContext(), + llvm::AttributeSet::FunctionIndex, B)); + return; + } + + if (D->hasAttr<NakedAttr>()) { + // Naked implies noinline: we should not be inlining such functions. + B.addAttribute(llvm::Attribute::Naked); + B.addAttribute(llvm::Attribute::NoInline); + } else if (D->hasAttr<NoDuplicateAttr>()) { + B.addAttribute(llvm::Attribute::NoDuplicate); + } else if (D->hasAttr<NoInlineAttr>()) { + B.addAttribute(llvm::Attribute::NoInline); + } else if (D->hasAttr<AlwaysInlineAttr>() && + !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, + llvm::Attribute::NoInline)) { + // (noinline wins over always_inline, and we can't specify both in IR) + B.addAttribute(llvm::Attribute::AlwaysInline); + } + + if (D->hasAttr<ColdAttr>()) { + if (!D->hasAttr<OptimizeNoneAttr>()) + B.addAttribute(llvm::Attribute::OptimizeForSize); + B.addAttribute(llvm::Attribute::Cold); + } + + if (D->hasAttr<MinSizeAttr>()) + B.addAttribute(llvm::Attribute::MinSize); + + F->addAttributes(llvm::AttributeSet::FunctionIndex, + llvm::AttributeSet::get( + F->getContext(), llvm::AttributeSet::FunctionIndex, B)); + + if (D->hasAttr<OptimizeNoneAttr>()) { + // OptimizeNone implies noinline; we should not be inlining such functions. + F->addFnAttr(llvm::Attribute::OptimizeNone); + F->addFnAttr(llvm::Attribute::NoInline); + + // OptimizeNone wins over OptimizeForSize, MinSize, AlwaysInline. + F->removeFnAttr(llvm::Attribute::OptimizeForSize); + F->removeFnAttr(llvm::Attribute::MinSize); + assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) && + "OptimizeNone and AlwaysInline on same function!"); + + // Attribute 'inlinehint' has no effect on 'optnone' functions. + // Explicitly remove it from the set of function attributes. + F->removeFnAttr(llvm::Attribute::InlineHint); + } + + if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) + F->setUnnamedAddr(true); + else if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) + if (MD->isVirtual()) + F->setUnnamedAddr(true); + + unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); + if (alignment) + F->setAlignment(alignment); + + // Some C++ ABIs require 2-byte alignment for member functions, in order to + // reserve a bit for differentiating between virtual and non-virtual member + // functions. If the current target's C++ ABI requires this and this is a + // member function, set its alignment accordingly. + if (getTarget().getCXXABI().areMemberFunctionsAligned()) { + if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) + F->setAlignment(2); + } +} + +void CodeGenModule::SetCommonAttributes(const Decl *D, + llvm::GlobalValue *GV) { + if (const auto *ND = dyn_cast_or_null<NamedDecl>(D)) + setGlobalVisibility(GV, ND); + else + GV->setVisibility(llvm::GlobalValue::DefaultVisibility); + + if (D && D->hasAttr<UsedAttr>()) + addUsedGlobal(GV); +} + +void CodeGenModule::setAliasAttributes(const Decl *D, + llvm::GlobalValue *GV) { + SetCommonAttributes(D, GV); + + // Process the dllexport attribute based on whether the original definition + // (not necessarily the aliasee) was exported. + if (D->hasAttr<DLLExportAttr>()) + GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass); +} + +void CodeGenModule::setNonAliasAttributes(const Decl *D, + llvm::GlobalObject *GO) { + SetCommonAttributes(D, GO); + + if (D) + if (const SectionAttr *SA = D->getAttr<SectionAttr>()) + GO->setSection(SA->getName()); + + getTargetCodeGenInfo().setTargetAttributes(D, GO, *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); + + setNonAliasAttributes(D, F); +} + +static void setLinkageAndVisibilityForGV(llvm::GlobalValue *GV, + const NamedDecl *ND) { + // Set linkage and visibility in case we never see a definition. + LinkageInfo LV = ND->getLinkageAndVisibility(); + if (LV.getLinkage() != ExternalLinkage) { + // Don't set internal linkage on declarations. + } else { + if (ND->hasAttr<DLLImportAttr>()) { + GV->setLinkage(llvm::GlobalValue::ExternalLinkage); + GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass); + } else if (ND->hasAttr<DLLExportAttr>()) { + GV->setLinkage(llvm::GlobalValue::ExternalLinkage); + GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass); + } else if (ND->hasAttr<WeakAttr>() || ND->isWeakImported()) { + // "extern_weak" is overloaded in LLVM; we probably should have + // separate linkage types for this. + GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); + } + + // Set visibility on a declaration only if it's explicit. + if (LV.isVisibilityExplicit()) + GV->setVisibility(CodeGenModule::GetLLVMVisibility(LV.getVisibility())); + } +} + +void CodeGenModule::CreateFunctionBitSetEntry(const FunctionDecl *FD, + llvm::Function *F) { + // Only if we are checking indirect calls. + if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall)) + return; + + // Non-static class methods are handled via vtable pointer checks elsewhere. + if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) + return; + + // Additionally, if building with cross-DSO support... + if (CodeGenOpts.SanitizeCfiCrossDso) { + // Don't emit entries for function declarations. In cross-DSO mode these are + // handled with better precision at run time. + if (!FD->hasBody()) + return; + // Skip available_externally functions. They won't be codegen'ed in the + // current module anyway. + if (getContext().GetGVALinkageForFunction(FD) == GVA_AvailableExternally) + return; + } + + llvm::NamedMDNode *BitsetsMD = + getModule().getOrInsertNamedMetadata("llvm.bitsets"); + + llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType()); + llvm::Metadata *BitsetOps[] = { + MD, llvm::ConstantAsMetadata::get(F), + llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(Int64Ty, 0))}; + BitsetsMD->addOperand(llvm::MDTuple::get(getLLVMContext(), BitsetOps)); + + // Emit a hash-based bit set entry for cross-DSO calls. + if (CodeGenOpts.SanitizeCfiCrossDso) { + if (auto TypeId = CreateCfiIdForTypeMetadata(MD)) { + llvm::Metadata *BitsetOps2[] = { + llvm::ConstantAsMetadata::get(TypeId), + llvm::ConstantAsMetadata::get(F), + llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(Int64Ty, 0))}; + BitsetsMD->addOperand(llvm::MDTuple::get(getLLVMContext(), BitsetOps2)); + } + } +} + +void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F, + bool IsIncompleteFunction, + bool IsThunk) { + if (llvm::Intrinsic::ID 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(), IID)); + return; + } + + const auto *FD = cast<FunctionDecl>(GD.getDecl()); + + if (!IsIncompleteFunction) + SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); + + // Add the Returned attribute for "this", except for iOS 5 and earlier + // where substantial code, including the libstdc++ dylib, was compiled with + // GCC and does not actually return "this". + if (!IsThunk && getCXXABI().HasThisReturn(GD) && + !(getTarget().getTriple().isiOS() && + getTarget().getTriple().isOSVersionLT(6))) { + assert(!F->arg_empty() && + F->arg_begin()->getType() + ->canLosslesslyBitCastTo(F->getReturnType()) && + "unexpected this return"); + F->addAttribute(1, llvm::Attribute::Returned); + } + + // Only a few attributes are set on declarations; these may later be + // overridden by a definition. + + setLinkageAndVisibilityForGV(F, FD); + + if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) + F->setSection(SA->getName()); + + // A replaceable global allocation function does not act like a builtin by + // default, only if it is invoked by a new-expression or delete-expression. + if (FD->isReplaceableGlobalAllocationFunction()) + F->addAttribute(llvm::AttributeSet::FunctionIndex, + llvm::Attribute::NoBuiltin); + + CreateFunctionBitSetEntry(FD, F); +} + +void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) { + assert(!GV->isDeclaration() && + "Only globals with definition can force usage."); + LLVMUsed.emplace_back(GV); +} + +void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) { + assert(!GV->isDeclaration() && + "Only globals with definition can force usage."); + LLVMCompilerUsed.emplace_back(GV); +} + +static void emitUsed(CodeGenModule &CGM, StringRef Name, + std::vector<llvm::WeakVH> &List) { + // Don't create llvm.used if there is no need. + if (List.empty()) + return; + + // Convert List to what ConstantArray needs. + SmallVector<llvm::Constant*, 8> UsedArray; + UsedArray.resize(List.size()); + for (unsigned i = 0, e = List.size(); i != e; ++i) { + UsedArray[i] = + llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast( + cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy); + } + + if (UsedArray.empty()) + return; + llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size()); + + auto *GV = new llvm::GlobalVariable( + CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage, + llvm::ConstantArray::get(ATy, UsedArray), Name); + + GV->setSection("llvm.metadata"); +} + +void CodeGenModule::emitLLVMUsed() { + emitUsed(*this, "llvm.used", LLVMUsed); + emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed); +} + +void CodeGenModule::AppendLinkerOptions(StringRef Opts) { + auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts); + LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); +} + +void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) { + llvm::SmallString<32> Opt; + getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt); + auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); + LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); +} + +void CodeGenModule::AddDependentLib(StringRef Lib) { + llvm::SmallString<24> Opt; + getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt); + auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); + LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); +} + +/// \brief Add link options implied by the given module, including modules +/// it depends on, using a postorder walk. +static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod, + SmallVectorImpl<llvm::Metadata *> &Metadata, + llvm::SmallPtrSet<Module *, 16> &Visited) { + // Import this module's parent. + if (Mod->Parent && Visited.insert(Mod->Parent).second) { + addLinkOptionsPostorder(CGM, 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]).second) + addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited); + } + + // Add linker options to link against the libraries/frameworks + // described by this module. + llvm::LLVMContext &Context = CGM.getLLVMContext(); + for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { + // Link against a framework. Frameworks are currently Darwin only, so we + // don't to ask TargetCodeGenInfo for the spelling of the linker option. + if (Mod->LinkLibraries[I-1].IsFramework) { + llvm::Metadata *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::SmallString<24> Opt; + CGM.getTargetCodeGenInfo().getDependentLibraryOption( + Mod->LinkLibraries[I-1].Library, Opt); + auto *OptString = llvm::MDString::get(Context, Opt); + 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 (Module *M : ImportedModules) + if (Visited.insert(M).second) + 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.pop_back_val(); + + 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).second) { + 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. We don't do anything to try to order import link flags with respect + // to linker options inserted by things like #pragma comment(). + SmallVector<llvm::Metadata *, 16> MetadataArgs; + Visited.clear(); + for (Module *M : LinkModules) + if (Visited.insert(M).second) + addLinkOptionsPostorder(*this, M, MetadataArgs, Visited); + std::reverse(MetadataArgs.begin(), MetadataArgs.end()); + LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end()); + + // Add the linker options metadata flag. + getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", + llvm::MDNode::get(getLLVMContext(), + LinkerOptionsMetadata)); +} + +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. + + 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()) + return; + + // Grab the list of decls to emit. If EmitGlobalDefinition schedules more + // work, it will not interfere with this. + std::vector<DeferredGlobal> CurDeclsToEmit; + CurDeclsToEmit.swap(DeferredDeclsToEmit); + + for (DeferredGlobal &G : CurDeclsToEmit) { + GlobalDecl D = G.GD; + llvm::GlobalValue *GV = G.GV; + G.GV = nullptr; + + // We should call GetAddrOfGlobal with IsForDefinition set to true in order + // to get GlobalValue with exactly the type we need, not something that + // might had been created for another decl with the same mangled name but + // different type. + // FIXME: Support for variables is not implemented yet. + if (isa<FunctionDecl>(D.getDecl())) + GV = cast<llvm::GlobalValue>(GetAddrOfGlobal(D, /*IsForDefinition=*/true)); + else + if (!GV) + GV = GetGlobalValue(getMangledName(D)); + + // 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. + if (GV && !GV->isDeclaration()) + continue; + + // Otherwise, emit the definition and move on to the next one. + EmitGlobalDefinition(D, GV); + + // If we found out that we need to emit more decls, do that recursively. + // This has the advantage that the decls are emitted in a DFS and related + // ones are close together, which is convenient for testing. + if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) { + EmitDeferred(); + assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty()); + } + } +} + +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); + auto *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::Constant *&AStr = AnnotationStrings[Str]; + if (AStr) + return AStr; + + // Not found yet, create a new global. + llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); + auto *gv = + new llvm::GlobalVariable(getModule(), s->getType(), true, + llvm::GlobalValue::PrivateLinkage, s, ".str"); + gv->setSection(AnnotationSection); + gv->setUnnamedAddr(true); + AStr = 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 (const auto *I : D->specific_attrs<AnnotateAttr>()) + Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation())); +} + +bool CodeGenModule::isInSanitizerBlacklist(llvm::Function *Fn, + SourceLocation Loc) const { + const auto &SanitizerBL = getContext().getSanitizerBlacklist(); + // Blacklist by function name. + if (SanitizerBL.isBlacklistedFunction(Fn->getName())) + return true; + // Blacklist by location. + if (Loc.isValid()) + return SanitizerBL.isBlacklistedLocation(Loc); + // If location is unknown, this may be a compiler-generated function. Assume + // it's located in the main file. + auto &SM = Context.getSourceManager(); + if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) { + return SanitizerBL.isBlacklistedFile(MainFile->getName()); + } + return false; +} + +bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV, + SourceLocation Loc, QualType Ty, + StringRef Category) const { + // For now globals can be blacklisted only in ASan and KASan. + if (!LangOpts.Sanitize.hasOneOf( + SanitizerKind::Address | SanitizerKind::KernelAddress)) + return false; + const auto &SanitizerBL = getContext().getSanitizerBlacklist(); + if (SanitizerBL.isBlacklistedGlobal(GV->getName(), Category)) + return true; + if (SanitizerBL.isBlacklistedLocation(Loc, Category)) + return true; + // Check global type. + if (!Ty.isNull()) { + // Drill down the array types: if global variable of a fixed type is + // blacklisted, we also don't instrument arrays of them. + while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr())) + Ty = AT->getElementType(); + Ty = Ty.getCanonicalType().getUnqualifiedType(); + // We allow to blacklist only record types (classes, structs etc.) + if (Ty->isRecordType()) { + std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy()); + if (SanitizerBL.isBlacklistedType(TypeStr, Category)) + return true; + } + } + return false; +} + +bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) { + // Never defer when EmitAllDecls is specified. + if (LangOpts.EmitAllDecls) + return true; + + return getContext().DeclMustBeEmitted(Global); +} + +bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) { + if (const auto *FD = dyn_cast<FunctionDecl>(Global)) + if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) + // Implicit template instantiations may change linkage if they are later + // explicitly instantiated, so they should not be emitted eagerly. + return false; + // If OpenMP is enabled and threadprivates must be generated like TLS, delay + // codegen for global variables, because they may be marked as threadprivate. + if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS && + getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global)) + return false; + + return true; +} + +ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor( + const CXXUuidofExpr* E) { + // Sema has verified that IIDSource has a __declspec(uuid()), and that its + // well-formed. + StringRef Uuid = E->getUuidAsStringRef(Context); + std::string Name = "_GUID_" + Uuid.lower(); + std::replace(Name.begin(), Name.end(), '-', '_'); + + // Contains a 32-bit field. + CharUnits Alignment = CharUnits::fromQuantity(4); + + // Look for an existing global. + if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) + return ConstantAddress(GV, Alignment); + + llvm::Constant *Init = EmitUuidofInitializer(Uuid); + assert(Init && "failed to initialize as constant"); + + auto *GV = new llvm::GlobalVariable( + getModule(), Init->getType(), + /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name); + if (supportsCOMDAT()) + GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); + return ConstantAddress(GV, Alignment); +} + +ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { + const AliasAttr *AA = VD->getAttr<AliasAttr>(); + assert(AA && "No alias?"); + + CharUnits Alignment = getContext().getDeclAlign(VD); + 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()); + auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); + return ConstantAddress(Ptr, Alignment); + } + + 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), + nullptr); + + auto *F = cast<llvm::GlobalValue>(Aliasee); + F->setLinkage(llvm::Function::ExternalWeakLinkage); + WeakRefReferences.insert(F); + + return ConstantAddress(Aliasee, Alignment); +} + +void CodeGenModule::EmitGlobal(GlobalDecl GD) { + const auto *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 (LangOpts.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 auto *FD = dyn_cast<FunctionDecl>(Global)) { + // Forward declarations are emitted lazily on first use. + if (!FD->doesThisDeclarationHaveABody()) { + if (!FD->doesDeclarationForceExternallyVisibleDefinition()) + return; + + StringRef MangledName = getMangledName(GD); + + // Compute the function info and LLVM type. + const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); + llvm::Type *Ty = getTypes().GetFunctionType(FI); + + GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false, + /*DontDefer=*/false); + return; + } + } else { + const auto *VD = cast<VarDecl>(Global); + assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); + + if (VD->isThisDeclarationADefinition() != VarDecl::Definition && + !Context.isMSStaticDataMemberInlineDefinition(VD)) + return; + } + + // Defer code generation to first use when possible, e.g. if this is an inline + // function. If the global must always be emitted, do it eagerly if possible + // to benefit from cache locality. + if (MustBeEmitted(Global) && MayBeEmittedEagerly(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(nullptr); + } + + StringRef MangledName = getMangledName(GD); + if (llvm::GlobalValue *GV = GetGlobalValue(MangledName)) { + // The value has already been used and should therefore be emitted. + addDeferredDeclToEmit(GV, GD); + } else if (MustBeEmitted(Global)) { + // The value must be emitted, but cannot be emitted eagerly. + assert(!MayBeEmittedEagerly(Global)); + addDeferredDeclToEmit(/*GV=*/nullptr, 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 || !BI.isLibFunction(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; + } + }; + + struct DLLImportFunctionVisitor + : public RecursiveASTVisitor<DLLImportFunctionVisitor> { + bool SafeToInline = true; + + bool VisitVarDecl(VarDecl *VD) { + // A thread-local variable cannot be imported. + SafeToInline = !VD->getTLSKind(); + return SafeToInline; + } + + // Make sure we're not referencing non-imported vars or functions. + bool VisitDeclRefExpr(DeclRefExpr *E) { + ValueDecl *VD = E->getDecl(); + if (isa<FunctionDecl>(VD)) + SafeToInline = VD->hasAttr<DLLImportAttr>(); + else if (VarDecl *V = dyn_cast<VarDecl>(VD)) + SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>(); + return SafeToInline; + } + bool VisitCXXDeleteExpr(CXXDeleteExpr *E) { + SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>(); + return SafeToInline; + } + bool VisitCXXNewExpr(CXXNewExpr *E) { + SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>(); + return SafeToInline; + } + }; +} + +// 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(GlobalDecl GD) { + if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage) + return true; + const auto *F = cast<FunctionDecl>(GD.getDecl()); + if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>()) + return false; + + if (F->hasAttr<DLLImportAttr>()) { + // Check whether it would be safe to inline this dllimport function. + DLLImportFunctionVisitor Visitor; + Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F)); + if (!Visitor.SafeToInline) + 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); +} + +/// If the type for the method's class was generated by +/// CGDebugInfo::createContextChain(), the cache contains only a +/// limited DIType without any declarations. Since EmitFunctionStart() +/// needs to find the canonical declaration for each method, we need +/// to construct the complete type prior to emitting the method. +void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) { + if (!D->isInstance()) + return; + + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) { + const auto *ThisPtr = cast<PointerType>(D->getThisType(getContext())); + DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation()); + } +} + +void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) { + const auto *D = cast<ValueDecl>(GD.getDecl()); + + PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), + Context.getSourceManager(), + "Generating code for declaration"); + + if (isa<FunctionDecl>(D)) { + // At -O0, don't generate IR for functions with available_externally + // linkage. + if (!shouldEmitFunction(GD)) + return; + + if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) { + CompleteDIClassType(Method); + // Make sure to emit the definition(s) before we emit the thunks. + // This is necessary for the generation of certain thunks. + if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method)) + ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType())); + else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method)) + ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType())); + else + EmitGlobalFunctionDefinition(GD, GV); + + if (Method->isVirtual()) + getVTables().EmitThunks(GD); + + return; + } + + return EmitGlobalFunctionDefinition(GD, GV); + } + + if (const auto *VD = dyn_cast<VarDecl>(D)) + return EmitGlobalVarDefinition(VD); + + llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); +} + +static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, + llvm::Function *NewFn); + +/// 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 GD, bool ForVTable, + bool DontDefer, bool IsThunk, + llvm::AttributeSet ExtraAttrs, + bool IsForDefinition) { + const Decl *D = GD.getDecl(); + + // 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); + if (FD && !FD->hasAttr<WeakAttr>()) + Entry->setLinkage(llvm::Function::ExternalLinkage); + } + + // Handle dropped DLL attributes. + if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) + Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass); + + // If there are two attempts to define the same mangled name, issue an + // error. + if (IsForDefinition && !Entry->isDeclaration()) { + GlobalDecl OtherGD; + // Check that GD is not yet in ExplicitDefinitions is required to make + // sure that we issue an error only once. + if (lookupRepresentativeDecl(MangledName, OtherGD) && + (GD.getCanonicalDecl().getDecl() != + OtherGD.getCanonicalDecl().getDecl()) && + DiagnosedConflictingDefinitions.insert(GD).second) { + getDiags().Report(D->getLocation(), + diag::err_duplicate_mangled_name); + getDiags().Report(OtherGD.getDecl()->getLocation(), + diag::note_previous_definition); + } + } + + if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) && + (Entry->getType()->getElementType() == Ty)) { + return Entry; + } + + // Make sure the result is of the correct type. + // (If function is requested for a definition, we always need to create a new + // function, not just return a bitcast.) + if (!IsForDefinition) + 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, + Entry ? StringRef() : MangledName, &getModule()); + + // If we already created a function with the same mangled name (but different + // type) before, take its name and add it to the list of functions to be + // replaced with F at the end of CodeGen. + // + // 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)"). + if (Entry) { + F->takeName(Entry); + + // 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 (!Entry->use_empty()) { + ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F); + Entry->removeDeadConstantUsers(); + } + + llvm::Constant *BC = llvm::ConstantExpr::getBitCast( + F, Entry->getType()->getElementType()->getPointerTo()); + addGlobalValReplacement(Entry, BC); + } + + assert(F->getName() == MangledName && "name was uniqued!"); + if (D) + SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk); + 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)); + } + + if (!DontDefer) { + // All MSVC dtors other than the base dtor are linkonce_odr and delegate to + // each other bottoming out with the base dtor. Therefore we emit non-base + // dtors on usage, even if there is no dtor definition in the TU. + if (D && isa<CXXDestructorDecl>(D) && + getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), + GD.getDtorType())) + addDeferredDeclToEmit(F, GD); + + // 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. + auto 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). + addDeferredDeclToEmit(F, 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) { + // Look for a declaration that's lexically in a record. + for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD; + FD = FD->getPreviousDecl()) { + if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { + if (FD->doesThisDeclarationHaveABody()) { + addDeferredDeclToEmit(F, GD.getWithDecl(FD)); + break; + } + } + } + } + } + + // 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, + bool DontDefer, + bool IsForDefinition) { + // If there was no specific requested type, just convert it now. + if (!Ty) { + const auto *FD = cast<FunctionDecl>(GD.getDecl()); + auto CanonTy = Context.getCanonicalType(FD->getType()); + Ty = getTypes().ConvertFunctionType(CanonTy, FD); + } + + StringRef MangledName = getMangledName(GD); + return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer, + /*IsThunk=*/false, llvm::AttributeSet(), + IsForDefinition); +} + +/// 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, + /*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs); + if (auto *F = dyn_cast<llvm::Function>(C)) + if (F->empty()) + F->setCallingConv(getRuntimeCC()); + return C; +} + +/// CreateBuiltinFunction - Create a new builtin function with the specified +/// type and name. +llvm::Constant * +CodeGenModule::CreateBuiltinFunction(llvm::FunctionType *FTy, + StringRef Name, + llvm::AttributeSet ExtraAttrs) { + llvm::Constant *C = + GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, + /*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs); + if (auto *F = dyn_cast<llvm::Function>(C)) + if (F->empty()) + F->setCallingConv(getBuiltinCC()); + 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) { + // 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); + } + + // Handle dropped DLL attributes. + if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) + Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass); + + if (Entry->getType() == Ty) + return Entry; + + // Make sure the result is of the correct type. + if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace()) + return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty); + + return llvm::ConstantExpr::getBitCast(Entry, Ty); + } + + unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); + auto *GV = new llvm::GlobalVariable( + getModule(), Ty->getElementType(), false, + llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr, + llvm::GlobalVariable::NotThreadLocal, AddrSpace); + + // 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. + auto 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). + addDeferredDeclToEmit(GV, DDI->second); + DeferredDecls.erase(DDI); + } + + // 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)); + + GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); + + setLinkageAndVisibilityForGV(GV, D); + + if (D->getTLSKind()) { + if (D->getTLSKind() == VarDecl::TLS_Dynamic) + CXXThreadLocals.push_back(D); + setTLSMode(GV, *D); + } + + // If required by the ABI, treat declarations of static data members with + // inline initializers as definitions. + if (getContext().isMSStaticDataMemberInlineDefinition(D)) { + EmitGlobalVarDefinition(D); + } + + // Handle XCore specific ABI requirements. + if (getTarget().getTriple().getArch() == llvm::Triple::xcore && + D->getLanguageLinkage() == CLanguageLinkage && + D->getType().isConstant(Context) && + isExternallyVisible(D->getLinkageAndVisibility().getLinkage())) + GV->setSection(".cp.rodata"); + } + + if (AddrSpace != Ty->getAddressSpace()) + return llvm::ConstantExpr::getAddrSpaceCast(GV, Ty); + + return GV; +} + +llvm::Constant * +CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, + bool IsForDefinition) { + if (isa<CXXConstructorDecl>(GD.getDecl())) + return getAddrOfCXXStructor(cast<CXXConstructorDecl>(GD.getDecl()), + getFromCtorType(GD.getCtorType()), + /*FnInfo=*/nullptr, /*FnType=*/nullptr, + /*DontDefer=*/false, IsForDefinition); + else if (isa<CXXDestructorDecl>(GD.getDecl())) + return getAddrOfCXXStructor(cast<CXXDestructorDecl>(GD.getDecl()), + getFromDtorType(GD.getDtorType()), + /*FnInfo=*/nullptr, /*FnType=*/nullptr, + /*DontDefer=*/false, IsForDefinition); + else if (isa<CXXMethodDecl>(GD.getDecl())) { + auto FInfo = &getTypes().arrangeCXXMethodDeclaration( + cast<CXXMethodDecl>(GD.getDecl())); + auto Ty = getTypes().GetFunctionType(*FInfo); + return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false, + IsForDefinition); + } else if (isa<FunctionDecl>(GD.getDecl())) { + const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); + llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); + return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false, + IsForDefinition); + } else + return GetAddrOfGlobalVar(cast<VarDecl>(GD.getDecl())); +} + +llvm::GlobalVariable * +CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, + llvm::Type *Ty, + llvm::GlobalValue::LinkageTypes Linkage) { + llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); + llvm::GlobalVariable *OldGV = nullptr; + + 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, nullptr, 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(); + } + + if (supportsCOMDAT() && GV->isWeakForLinker() && + !GV->hasAvailableExternallyLinkage()) + GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); + + 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) + 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), nullptr); +} + +void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { + assert(!D->getInit() && "Cannot emit definite definitions here!"); + + if (!MustBeEmitted(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( + getDataLayout().getTypeStoreSizeInBits(Ty)); +} + +unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, + unsigned AddrSpace) { + if (LangOpts.CUDA && LangOpts.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; +} + +template<typename SomeDecl> +void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, + llvm::GlobalValue *GV) { + if (!getLangOpts().CPlusPlus) + return; + + // Must have 'used' attribute, or else inline assembly can't rely on + // the name existing. + if (!D->template hasAttr<UsedAttr>()) + return; + + // Must have internal linkage and an ordinary name. + if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage) + return; + + // Must be in an extern "C" context. Entities declared directly within + // a record are not extern "C" even if the record is in such a context. + const SomeDecl *First = D->getFirstDecl(); + if (First->getDeclContext()->isRecord() || !First->isInExternCContext()) + return; + + // OK, this is an internal linkage entity inside an extern "C" linkage + // specification. Make a note of that so we can give it the "expected" + // mangled name if nothing else is using that name. + std::pair<StaticExternCMap::iterator, bool> R = + StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); + + // If we have multiple internal linkage entities with the same name + // in extern "C" regions, none of them gets that name. + if (!R.second) + R.first->second = nullptr; +} + +static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) { + if (!CGM.supportsCOMDAT()) + return false; + + if (D.hasAttr<SelectAnyAttr>()) + return true; + + GVALinkage Linkage; + if (auto *VD = dyn_cast<VarDecl>(&D)) + Linkage = CGM.getContext().GetGVALinkageForVariable(VD); + else + Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D)); + + switch (Linkage) { + case GVA_Internal: + case GVA_AvailableExternally: + case GVA_StrongExternal: + return false; + case GVA_DiscardableODR: + case GVA_StrongODR: + return true; + } + llvm_unreachable("No such linkage"); +} + +void CodeGenModule::maybeSetTrivialComdat(const Decl &D, + llvm::GlobalObject &GO) { + if (!shouldBeInCOMDAT(*this, D)) + return; + GO.setComdat(TheModule.getOrInsertComdat(GO.getName())); +} + +void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { + llvm::Constant *Init = nullptr; + 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); + + // CUDA E.2.4.1 "__shared__ variables cannot have an initialization as part + // of their declaration." + if (getLangOpts().CPlusPlus && getLangOpts().CUDAIsDevice + && D->hasAttr<CUDASharedAttr>()) { + if (InitExpr) { + const auto *C = dyn_cast<CXXConstructExpr>(InitExpr); + if (C == nullptr || !C->getConstructor()->hasTrivialBody()) + Error(D->getLocation(), + "__shared__ variable cannot have an initialization."); + } + Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy)); + } else 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 { + 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 (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { + assert(CE->getOpcode() == llvm::Instruction::BitCast || + CE->getOpcode() == llvm::Instruction::AddrSpaceCast || + // All zero index gep. + CE->getOpcode() == llvm::Instruction::GetElementPtr); + Entry = CE->getOperand(0); + } + + // Entry is now either a Function or GlobalVariable. + auto *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 || + 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(); + } + + MaybeHandleStaticInExternC(D, GV); + + if (D->hasAttr<AnnotateAttr>()) + AddGlobalAnnotations(D, GV); + + // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on + // the device. [...]" + // CUDA B.2.2 "The __constant__ qualifier, optionally used together with + // __device__, declares a variable that: [...] + // Is accessible from all the threads within the grid and from the host + // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize() + // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())." + if (GV && LangOpts.CUDA && LangOpts.CUDAIsDevice && + (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>())) { + GV->setExternallyInitialized(true); + } + GV->setInitializer(Init); + + // If it is safe to mark the global 'constant', do so now. + GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && + isTypeConstant(D->getType(), true)); + + // If it is in a read-only section, mark it 'constant'. + if (const SectionAttr *SA = D->getAttr<SectionAttr>()) { + const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()]; + if ((SI.SectionFlags & ASTContext::PSF_Write) == 0) + GV->setConstant(true); + } + + GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); + + // Set the llvm linkage type as appropriate. + llvm::GlobalValue::LinkageTypes Linkage = + getLLVMLinkageVarDefinition(D, GV->isConstant()); + + // On Darwin, if the normal linkage of a C++ thread_local variable is + // LinkOnce or Weak, we keep the normal linkage to prevent multiple + // copies within a linkage unit; otherwise, the backing variable has + // internal linkage and all accesses should just be calls to the + // Itanium-specified entry point, which has the normal linkage of the + // variable. This is to preserve the ability to change the implementation + // behind the scenes. + if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic && + Context.getTargetInfo().getTriple().isOSDarwin() && + !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) && + !llvm::GlobalVariable::isWeakLinkage(Linkage)) + Linkage = llvm::GlobalValue::InternalLinkage; + + GV->setLinkage(Linkage); + if (D->hasAttr<DLLImportAttr>()) + GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass); + else if (D->hasAttr<DLLExportAttr>()) + GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass); + else + GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass); + + if (Linkage == llvm::GlobalVariable::CommonLinkage) + // common vars aren't constant even if declared const. + GV->setConstant(false); + + setNonAliasAttributes(D, GV); + + if (D->getTLSKind() && !GV->isThreadLocal()) { + if (D->getTLSKind() == VarDecl::TLS_Dynamic) + CXXThreadLocals.push_back(D); + setTLSMode(GV, *D); + } + + maybeSetTrivialComdat(*D, *GV); + + // Emit the initializer function if necessary. + if (NeedsGlobalCtor || NeedsGlobalDtor) + EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); + + SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor); + + // Emit global variable debug information. + if (CGDebugInfo *DI = getModuleDebugInfo()) + if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) + DI->EmitGlobalVariable(GV, D); +} + +static bool isVarDeclStrongDefinition(const ASTContext &Context, + CodeGenModule &CGM, const VarDecl *D, + bool NoCommon) { + // Don't give variables common linkage if -fno-common was specified unless it + // was overridden by a NoCommon attribute. + if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>()) + return true; + + // C11 6.9.2/2: + // A declaration of an identifier for an object that has file scope without + // an initializer, and without a storage-class specifier or with the + // storage-class specifier static, constitutes a tentative definition. + if (D->getInit() || D->hasExternalStorage()) + return true; + + // A variable cannot be both common and exist in a section. + if (D->hasAttr<SectionAttr>()) + return true; + + // Thread local vars aren't considered common linkage. + if (D->getTLSKind()) + return true; + + // Tentative definitions marked with WeakImportAttr are true definitions. + if (D->hasAttr<WeakImportAttr>()) + return true; + + // A variable cannot be both common and exist in a comdat. + if (shouldBeInCOMDAT(CGM, *D)) + return true; + + // Declarations with a required alignment do not have common linakge in MSVC + // mode. + if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { + if (D->hasAttr<AlignedAttr>()) + return true; + QualType VarType = D->getType(); + if (Context.isAlignmentRequired(VarType)) + return true; + + if (const auto *RT = VarType->getAs<RecordType>()) { + const RecordDecl *RD = RT->getDecl(); + for (const FieldDecl *FD : RD->fields()) { + if (FD->isBitField()) + continue; + if (FD->hasAttr<AlignedAttr>()) + return true; + if (Context.isAlignmentRequired(FD->getType())) + return true; + } + } + } + + return false; +} + +llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator( + const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) { + if (Linkage == GVA_Internal) + return llvm::Function::InternalLinkage; + + if (D->hasAttr<WeakAttr>()) { + if (IsConstantVariable) + return llvm::GlobalVariable::WeakODRLinkage; + else + return llvm::GlobalVariable::WeakAnyLinkage; + } + + // We are guaranteed to have a strong definition somewhere else, + // so we can use available_externally linkage. + if (Linkage == GVA_AvailableExternally) + 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_DiscardableODR) + 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_StrongODR) + return !Context.getLangOpts().AppleKext ? llvm::Function::WeakODRLinkage + : llvm::Function::ExternalLinkage; + + // C++ doesn't have tentative definitions and thus cannot have common + // linkage. + if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) && + !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D), + CodeGenOpts.NoCommon)) + return llvm::GlobalVariable::CommonLinkage; + + // selectany symbols are externally visible, so use weak instead of + // linkonce. MSVC optimizes away references to const selectany globals, so + // all definitions should be the same and ODR linkage should be used. + // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx + if (D->hasAttr<SelectAnyAttr>()) + return llvm::GlobalVariable::WeakODRLinkage; + + // Otherwise, we have strong external linkage. + assert(Linkage == GVA_StrongExternal); + return llvm::GlobalVariable::ExternalLinkage; +} + +llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition( + const VarDecl *VD, bool IsConstant) { + GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD); + return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant); +} + +/// 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; + SmallVector<llvm::OperandBundleDef, 1> newBundles; + + 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->getUser(); + + // Recognize and replace uses of bitcasts. Most calls to + // unprototyped functions will use bitcasts. + if (auto *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); + + // Copy over any operand bundles. + callSite.getOperandBundlesAsDefs(newBundles); + + llvm::CallSite newCall; + if (callSite.isCall()) { + newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "", + callSite.getInstruction()); + } else { + auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction()); + newCall = llvm::InvokeInst::Create(newFn, + oldInvoke->getNormalDest(), + oldInvoke->getUnwindDest(), + newArgs, newBundles, "", + 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()) + 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, + llvm::GlobalValue *GV) { + const auto *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. + if (!GV || (GV->getType()->getElementType() != Ty)) + GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, + /*DontDefer=*/true, + /*IsForDefinition=*/true)); + + // Already emitted. + if (!GV->isDeclaration()) + return; + + // 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). + auto *Fn = cast<llvm::Function>(GV); + setFunctionLinkage(GD, Fn); + setFunctionDLLStorageClass(GD, Fn); + + // FIXME: this is redundant with part of setFunctionDefinitionAttributes + setGlobalVisibility(Fn, D); + + MaybeHandleStaticInExternC(D, Fn); + + maybeSetTrivialComdat(*D, *Fn); + + 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 auto *D = cast<ValueDecl>(GD.getDecl()); + const AliasAttr *AA = D->getAttr<AliasAttr>(); + assert(AA && "Not an alias?"); + + StringRef MangledName = getMangledName(GD); + + if (AA->getAliasee() == MangledName) { + Diags.Report(AA->getLocation(), diag::err_cyclic_alias); + return; + } + + // 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; + + Aliases.push_back(GD); + + 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), + /*D=*/nullptr); + + // Create the new alias itself, but don't set a name yet. + auto *GA = llvm::GlobalAlias::create( + DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule()); + + if (Entry) { + if (GA->getAliasee() == Entry) { + Diags.Report(AA->getLocation(), diag::err_cyclic_alias); + return; + } + + 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<WeakAttr>() || D->hasAttr<WeakRefAttr>() || + D->isWeakImported()) { + GA->setLinkage(llvm::Function::WeakAnyLinkage); + } + + if (const auto *VD = dyn_cast<VarDecl>(D)) + if (VD->getTLSKind()) + setTLSMode(GA, *VD); + + setAliasAttributes(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::GlobalVariable *> & +GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &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.insert(std::make_pair(String, nullptr)).first; + } + + // 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.insert(std::make_pair( + StringRef(reinterpret_cast<const char *>(ToBuf.data()), + (StringLength + 1) * 2), + nullptr)).first; +} + +static llvm::StringMapEntry<llvm::GlobalVariable *> & +GetConstantStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map, + const StringLiteral *Literal, unsigned &StringLength) { + StringRef String = Literal->getString(); + StringLength = String.size(); + return *Map.insert(std::make_pair(String, nullptr)).first; +} + +ConstantAddress +CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { + unsigned StringLength = 0; + bool isUTF16 = false; + llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = + GetConstantCFStringEntry(CFConstantStringMap, Literal, + getDataLayout().isLittleEndian(), isUTF16, + StringLength); + + if (auto *C = Entry.second) + return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment())); + + llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); + llvm::Constant *Zeros[] = { Zero, Zero }; + llvm::Value *V; + + // 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 + V = llvm::ConstantExpr::getGetElementPtr(Ty, GV, Zeros); + CFConstantStringClassRef = V; + } + else + V = CFConstantStringClassRef; + + QualType CFTy = getContext().getCFConstantStringType(); + + auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy)); + + llvm::Constant *Fields[4]; + + // Class pointer. + Fields[0] = cast<llvm::ConstantExpr>(V); + + // 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 = nullptr; + if (isUTF16) { + auto Arr = llvm::makeArrayRef( + reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())), + Entry.first().size() / 2); + C = llvm::ConstantDataArray::get(VMContext, Arr); + } else { + C = llvm::ConstantDataArray::getString(VMContext, Entry.first()); + } + + // Note: -fwritable-strings doesn't make the backing store strings of + // CFStrings writable. (See <rdar://problem/10657500>) + auto *GV = + new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, + llvm::GlobalValue::PrivateLinkage, C, ".str"); + GV->setUnnamedAddr(true); + // Don't enforce the target's minimum global alignment, since the only use + // of the string is via this class initializer. + // FIXME: We set the section explicitly to avoid a bug in ld64 224.1. Without + // it LLVM can merge the string with a non unnamed_addr one during LTO. Doing + // that changes the section it ends in, which surprises ld64. + if (isUTF16) { + CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); + GV->setAlignment(Align.getQuantity()); + GV->setSection("__TEXT,__ustring"); + } else { + CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); + GV->setAlignment(Align.getQuantity()); + GV->setSection("__TEXT,__cstring,cstring_literals"); + } + + // String. + Fields[2] = + llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), 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); + + CharUnits Alignment = getPointerAlign(); + + // The struct. + C = llvm::ConstantStruct::get(STy, Fields); + GV = new llvm::GlobalVariable(getModule(), C->getType(), true, + llvm::GlobalVariable::PrivateLinkage, C, + "_unnamed_cfstring_"); + GV->setSection("__DATA,__cfstring"); + GV->setAlignment(Alignment.getQuantity()); + Entry.second = GV; + + return ConstantAddress(GV, Alignment); +} + +ConstantAddress +CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { + unsigned StringLength = 0; + llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = + GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); + + if (auto *C = Entry.second) + return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment())); + + llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); + llvm::Constant *Zeros[] = { Zero, Zero }; + llvm::Value *V; + // 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); + V = llvm::ConstantExpr::getBitCast(GV, PTy); + ConstantStringClassRef = V; + } else { + std::string str = + StringClass.empty() ? "_NSConstantStringClassReference" + : "_" + StringClass + "ClassReference"; + llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); + GV = CreateRuntimeVariable(PTy, str); + // Decay array -> ptr + V = llvm::ConstantExpr::getGetElementPtr(PTy, GV, Zeros); + ConstantStringClassRef = V; + } + } else + V = ConstantStringClassRef; + + if (!NSConstantStringType) { + // Construct the type for a constant NSString. + RecordDecl *D = Context.buildImplicitRecord("__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(), nullptr, + FieldTypes[i], /*TInfo=*/nullptr, + /*BitWidth=*/nullptr, + /*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] = cast<llvm::ConstantExpr>(V); + + // String pointer. + llvm::Constant *C = + llvm::ConstantDataArray::getString(VMContext, Entry.first()); + + llvm::GlobalValue::LinkageTypes Linkage; + bool isConstant; + Linkage = llvm::GlobalValue::PrivateLinkage; + isConstant = !LangOpts.WritableStrings; + + auto *GV = new llvm::GlobalVariable(getModule(), C->getType(), isConstant, + Linkage, C, ".str"); + GV->setUnnamedAddr(true); + // Don't enforce the target's minimum global alignment, since the only use + // of the string is via this class initializer. + CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); + GV->setAlignment(Align.getQuantity()); + Fields[1] = + llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros); + + // String length. + llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); + Fields[2] = llvm::ConstantInt::get(Ty, StringLength); + + // The struct. + CharUnits Alignment = getPointerAlign(); + C = llvm::ConstantStruct::get(NSConstantStringType, Fields); + GV = new llvm::GlobalVariable(getModule(), C->getType(), true, + llvm::GlobalVariable::PrivateLinkage, C, + "_unnamed_nsstring_"); + GV->setAlignment(Alignment.getQuantity()); + const char *NSStringSection = "__OBJC,__cstring_object,regular,no_dead_strip"; + const char *NSStringNonFragileABISection = + "__DATA,__objc_stringobj,regular,no_dead_strip"; + // FIXME. Fix section. + GV->setSection(LangOpts.ObjCRuntime.isNonFragile() + ? NSStringNonFragileABISection + : NSStringSection); + Entry.second = GV; + + return ConstantAddress(GV, Alignment); +} + +QualType CodeGenModule::getObjCFastEnumerationStateType() { + if (ObjCFastEnumerationStateType.isNull()) { + RecordDecl *D = Context.buildImplicitRecord("__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(), nullptr, + FieldTypes[i], /*TInfo=*/nullptr, + /*BitWidth=*/nullptr, + /*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); + } + + auto *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); +} + +static llvm::GlobalVariable * +GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT, + CodeGenModule &CGM, StringRef GlobalName, + CharUnits Alignment) { + // OpenCL v1.2 s6.5.3: a string literal is in the constant address space. + unsigned AddrSpace = 0; + if (CGM.getLangOpts().OpenCL) + AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant); + + llvm::Module &M = CGM.getModule(); + // Create a global variable for this string + auto *GV = new llvm::GlobalVariable( + M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName, + nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace); + GV->setAlignment(Alignment.getQuantity()); + GV->setUnnamedAddr(true); + if (GV->isWeakForLinker()) { + assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals"); + GV->setComdat(M.getOrInsertComdat(GV->getName())); + } + + return GV; +} + +/// GetAddrOfConstantStringFromLiteral - Return a pointer to a +/// constant array for the given string literal. +ConstantAddress +CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S, + StringRef Name) { + CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType()); + + llvm::Constant *C = GetConstantArrayFromStringLiteral(S); + llvm::GlobalVariable **Entry = nullptr; + if (!LangOpts.WritableStrings) { + Entry = &ConstantStringMap[C]; + if (auto GV = *Entry) { + if (Alignment.getQuantity() > GV->getAlignment()) + GV->setAlignment(Alignment.getQuantity()); + return ConstantAddress(GV, Alignment); + } + } + + SmallString<256> MangledNameBuffer; + StringRef GlobalVariableName; + llvm::GlobalValue::LinkageTypes LT; + + // Mangle the string literal if the ABI allows for it. However, we cannot + // do this if we are compiling with ASan or -fwritable-strings because they + // rely on strings having normal linkage. + if (!LangOpts.WritableStrings && + !LangOpts.Sanitize.has(SanitizerKind::Address) && + getCXXABI().getMangleContext().shouldMangleStringLiteral(S)) { + llvm::raw_svector_ostream Out(MangledNameBuffer); + getCXXABI().getMangleContext().mangleStringLiteral(S, Out); + + LT = llvm::GlobalValue::LinkOnceODRLinkage; + GlobalVariableName = MangledNameBuffer; + } else { + LT = llvm::GlobalValue::PrivateLinkage; + GlobalVariableName = Name; + } + + auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment); + if (Entry) + *Entry = GV; + + SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>", + QualType()); + return ConstantAddress(GV, Alignment); +} + +/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant +/// array for the given ObjCEncodeExpr node. +ConstantAddress +CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { + std::string Str; + getContext().getObjCEncodingForType(E->getEncodedType(), Str); + + return GetAddrOfConstantCString(Str); +} + +/// GetAddrOfConstantCString - Returns a pointer to a character array containing +/// the literal and a terminating '\0' character. +/// The result has pointer to array type. +ConstantAddress CodeGenModule::GetAddrOfConstantCString( + const std::string &Str, const char *GlobalName) { + StringRef StrWithNull(Str.c_str(), Str.size() + 1); + CharUnits Alignment = + getContext().getAlignOfGlobalVarInChars(getContext().CharTy); + + llvm::Constant *C = + llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false); + + // Don't share any string literals if strings aren't constant. + llvm::GlobalVariable **Entry = nullptr; + if (!LangOpts.WritableStrings) { + Entry = &ConstantStringMap[C]; + if (auto GV = *Entry) { + if (Alignment.getQuantity() > GV->getAlignment()) + GV->setAlignment(Alignment.getQuantity()); + return ConstantAddress(GV, Alignment); + } + } + + // Get the default prefix if a name wasn't specified. + if (!GlobalName) + GlobalName = ".str"; + // Create a global variable for this. + auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this, + GlobalName, Alignment); + if (Entry) + *Entry = GV; + return ConstantAddress(GV, Alignment); +} + +ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary( + const MaterializeTemporaryExpr *E, const Expr *Init) { + assert((E->getStorageDuration() == SD_Static || + E->getStorageDuration() == SD_Thread) && "not a global temporary"); + const auto *VD = cast<VarDecl>(E->getExtendingDecl()); + + // If we're not materializing a subobject of the temporary, keep the + // cv-qualifiers from the type of the MaterializeTemporaryExpr. + QualType MaterializedType = Init->getType(); + if (Init == E->GetTemporaryExpr()) + MaterializedType = E->getType(); + + CharUnits Align = getContext().getTypeAlignInChars(MaterializedType); + + if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E]) + return ConstantAddress(Slot, Align); + + // FIXME: If an externally-visible declaration extends multiple temporaries, + // we need to give each temporary the same name in every translation unit (and + // we also need to make the temporaries externally-visible). + SmallString<256> Name; + llvm::raw_svector_ostream Out(Name); + getCXXABI().getMangleContext().mangleReferenceTemporary( + VD, E->getManglingNumber(), Out); + + APValue *Value = nullptr; + if (E->getStorageDuration() == SD_Static) { + // We might have a cached constant initializer for this temporary. Note + // that this might have a different value from the value computed by + // evaluating the initializer if the surrounding constant expression + // modifies the temporary. + Value = getContext().getMaterializedTemporaryValue(E, false); + if (Value && Value->isUninit()) + Value = nullptr; + } + + // Try evaluating it now, it might have a constant initializer. + Expr::EvalResult EvalResult; + if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) && + !EvalResult.hasSideEffects()) + Value = &EvalResult.Val; + + llvm::Constant *InitialValue = nullptr; + bool Constant = false; + llvm::Type *Type; + if (Value) { + // The temporary has a constant initializer, use it. + InitialValue = EmitConstantValue(*Value, MaterializedType, nullptr); + Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value); + Type = InitialValue->getType(); + } else { + // No initializer, the initialization will be provided when we + // initialize the declaration which performed lifetime extension. + Type = getTypes().ConvertTypeForMem(MaterializedType); + } + + // Create a global variable for this lifetime-extended temporary. + llvm::GlobalValue::LinkageTypes Linkage = + getLLVMLinkageVarDefinition(VD, Constant); + if (Linkage == llvm::GlobalVariable::ExternalLinkage) { + const VarDecl *InitVD; + if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) && + isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) { + // Temporaries defined inside a class get linkonce_odr linkage because the + // class can be defined in multipe translation units. + Linkage = llvm::GlobalVariable::LinkOnceODRLinkage; + } else { + // There is no need for this temporary to have external linkage if the + // VarDecl has external linkage. + Linkage = llvm::GlobalVariable::InternalLinkage; + } + } + unsigned AddrSpace = GetGlobalVarAddressSpace( + VD, getContext().getTargetAddressSpace(MaterializedType)); + auto *GV = new llvm::GlobalVariable( + getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(), + /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, + AddrSpace); + setGlobalVisibility(GV, VD); + GV->setAlignment(Align.getQuantity()); + if (supportsCOMDAT() && GV->isWeakForLinker()) + GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); + if (VD->getTLSKind()) + setTLSMode(GV, *VD); + MaterializedGlobalTemporaryMap[E] = GV; + return ConstantAddress(GV, Align); +} + +/// EmitObjCPropertyImplementations - Emit information for synthesized +/// properties for an implementation. +void CodeGenModule::EmitObjCPropertyImplementations(const + ObjCImplementationDecl *D) { + for (const auto *PID : D->property_impls()) { + // 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; +} + +static bool AllTrivialInitializers(CodeGenModule &CGM, + ObjCImplementationDecl *D) { + CodeGenFunction CGF(CGM); + for (ObjCImplementationDecl::init_iterator B = D->init_begin(), + E = D->init_end(); B != E; ++B) { + CXXCtorInitializer *CtorInitExp = *B; + Expr *Init = CtorInitExp->getInit(); + if (!CGF.isTrivialInitializer(Init)) + return false; + } + return true; +} + +/// 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, nullptr, 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 || + AllTrivialInitializers(*this, D)) + 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(), + nullptr, 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 (auto *I : ND->decls()) { + if (const auto *VD = dyn_cast<VarDecl>(I)) + if (VD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization && + VD->getTemplateSpecializationKind() != TSK_Undeclared) + continue; + 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 (auto *I : LSD->decls()) { + // Meta-data for ObjC class includes references to implemented methods. + // Generate class's method definitions first. + if (auto *OID = dyn_cast<ObjCImplDecl>(I)) { + for (auto *M : OID->methods()) + EmitTopLevelDecl(M); + } + EmitTopLevelDecl(I); + } +} + +/// EmitTopLevelDecl - Emit code for a single top level declaration. +void CodeGenModule::EmitTopLevelDecl(Decl *D) { + // 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)); + // Always provide some coverage mapping + // even for the functions that aren't emitted. + AddDeferredUnusedCoverageMapping(D); + break; + + case Decl::Var: + // Skip variable templates + if (cast<VarDecl>(D)->getDescribedVarTemplate()) + return; + case Decl::VarTemplateSpecialization: + 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::ClassTemplate: + case Decl::VarTemplate: + case Decl::VarTemplatePartialSpecialization: + case Decl::FunctionTemplate: + case Decl::TypeAliasTemplate: + case Decl::Block: + case Decl::Empty: + break; + case Decl::Using: // using X; [C++] + if (CGDebugInfo *DI = getModuleDebugInfo()) + DI->EmitUsingDecl(cast<UsingDecl>(*D)); + return; + case Decl::NamespaceAlias: + if (CGDebugInfo *DI = getModuleDebugInfo()) + DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D)); + return; + case Decl::UsingDirective: // using namespace X; [C++] + if (CGDebugInfo *DI = getModuleDebugInfo()) + DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D)); + return; + case Decl::CXXConstructor: + // Skip function templates + if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || + cast<FunctionDecl>(D)->isLateTemplateParsed()) + return; + + getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D)); + break; + case Decl::CXXDestructor: + if (cast<FunctionDecl>(D)->isLateTemplateParsed()) + return; + getCXXABI().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: { + auto *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: { + auto *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: { + auto *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: { + // File-scope asm is ignored during device-side CUDA compilation. + if (LangOpts.CUDA && LangOpts.CUDAIsDevice) + break; + auto *AD = cast<FileScopeAsmDecl>(D); + getModule().appendModuleInlineAsm(AD->getAsmString()->getString()); + break; + } + + case Decl::Import: { + auto *Import = cast<ImportDecl>(D); + + // Ignore import declarations that come from imported modules. + if (Import->getImportedOwningModule()) + break; + if (CGDebugInfo *DI = getModuleDebugInfo()) + DI->EmitImportDecl(*Import); + + ImportedModules.insert(Import->getImportedModule()); + break; + } + + case Decl::OMPThreadPrivate: + EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D)); + break; + + case Decl::ClassTemplateSpecialization: { + const auto *Spec = cast<ClassTemplateSpecializationDecl>(D); + if (DebugInfo && + Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition && + Spec->hasDefinition()) + DebugInfo->completeTemplateDefinition(*Spec); + 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"); + break; + } +} + +void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) { + // Do we need to generate coverage mapping? + if (!CodeGenOpts.CoverageMapping) + return; + switch (D->getKind()) { + case Decl::CXXConversion: + case Decl::CXXMethod: + case Decl::Function: + case Decl::ObjCMethod: + case Decl::CXXConstructor: + case Decl::CXXDestructor: { + if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody()) + return; + auto I = DeferredEmptyCoverageMappingDecls.find(D); + if (I == DeferredEmptyCoverageMappingDecls.end()) + DeferredEmptyCoverageMappingDecls[D] = true; + break; + } + default: + break; + }; +} + +void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) { + // Do we need to generate coverage mapping? + if (!CodeGenOpts.CoverageMapping) + return; + if (const auto *Fn = dyn_cast<FunctionDecl>(D)) { + if (Fn->isTemplateInstantiation()) + ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern()); + } + auto I = DeferredEmptyCoverageMappingDecls.find(D); + if (I == DeferredEmptyCoverageMappingDecls.end()) + DeferredEmptyCoverageMappingDecls[D] = false; + else + I->second = false; +} + +void CodeGenModule::EmitDeferredUnusedCoverageMappings() { + std::vector<const Decl *> DeferredDecls; + for (const auto &I : DeferredEmptyCoverageMappingDecls) { + if (!I.second) + continue; + DeferredDecls.push_back(I.first); + } + // Sort the declarations by their location to make sure that the tests get a + // predictable order for the coverage mapping for the unused declarations. + if (CodeGenOpts.DumpCoverageMapping) + std::sort(DeferredDecls.begin(), DeferredDecls.end(), + [] (const Decl *LHS, const Decl *RHS) { + return LHS->getLocStart() < RHS->getLocStart(); + }); + for (const auto *D : DeferredDecls) { + switch (D->getKind()) { + case Decl::CXXConversion: + case Decl::CXXMethod: + case Decl::Function: + case Decl::ObjCMethod: { + CodeGenPGO PGO(*this); + GlobalDecl GD(cast<FunctionDecl>(D)); + PGO.emitEmptyCounterMapping(D, getMangledName(GD), + getFunctionLinkage(GD)); + break; + } + case Decl::CXXConstructor: { + CodeGenPGO PGO(*this); + GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base); + PGO.emitEmptyCounterMapping(D, getMangledName(GD), + getFunctionLinkage(GD)); + break; + } + case Decl::CXXDestructor: { + CodeGenPGO PGO(*this); + GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base); + PGO.emitEmptyCounterMapping(D, getMangledName(GD), + getFunctionLinkage(GD)); + break; + } + default: + break; + }; + } +} + +/// 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::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr), + llvm::ConstantAsMetadata::get(GetPointerConstant( + CGM.getLLVMContext(), D.getDecl()))}; + GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); +} + +/// For each function which is declared within an extern "C" region and marked +/// as 'used', but has internal linkage, create an alias from the unmangled +/// name to the mangled name if possible. People expect to be able to refer +/// to such functions with an unmangled name from inline assembly within the +/// same translation unit. +void CodeGenModule::EmitStaticExternCAliases() { + for (auto &I : StaticExternCValues) { + IdentifierInfo *Name = I.first; + llvm::GlobalValue *Val = I.second; + if (Val && !getModule().getNamedValue(Name->getName())) + addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val)); + } +} + +bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName, + GlobalDecl &Result) const { + auto Res = Manglings.find(MangledName); + if (Res == Manglings.end()) + return false; + Result = Res->getValue(); + return true; +} + +/// 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 = nullptr; + + for (auto &I : MangledDeclNames) { + llvm::GlobalValue *Addr = getModule().getNamedValue(I.second); + // Some mangled names don't necessarily have an associated GlobalValue + // in this module, e.g. if we mangled it for DebugInfo. + if (Addr) + 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 = nullptr; + + for (auto &I : LocalDeclMap) { + const Decl *D = I.first; + llvm::Value *Addr = I.second.getPointer(); + if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { + llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); + Alloca->setMetadata( + DeclPtrKind, llvm::MDNode::get( + Context, llvm::ValueAsMetadata::getConstant(DAddr))); + } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) { + GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); + EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); + } + } +} + +void CodeGenModule::EmitVersionIdentMetadata() { + llvm::NamedMDNode *IdentMetadata = + TheModule.getOrInsertNamedMetadata("llvm.ident"); + std::string Version = getClangFullVersion(); + llvm::LLVMContext &Ctx = TheModule.getContext(); + + llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)}; + IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode)); +} + +void CodeGenModule::EmitTargetMetadata() { + // Warning, new MangledDeclNames may be appended within this loop. + // We rely on MapVector insertions adding new elements to the end + // of the container. + // FIXME: Move this loop into the one target that needs it, and only + // loop over those declarations for which we couldn't emit the target + // metadata when we emitted the declaration. + for (unsigned I = 0; I != MangledDeclNames.size(); ++I) { + auto Val = *(MangledDeclNames.begin() + I); + const Decl *D = Val.first.getDecl()->getMostRecentDecl(); + llvm::GlobalValue *GV = GetGlobalValue(Val.second); + getTargetCodeGenInfo().emitTargetMD(D, GV, *this); + } +} + +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::Metadata *Elts[] = {CoverageFile, CU}; + GCov->addOperand(llvm::MDNode::get(Ctx, Elts)); + } + } + } +} + +llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) { + // Sema has checked that all uuid strings are of the form + // "12345678-1234-1234-1234-1234567890ab". + assert(Uuid.size() == 36); + for (unsigned i = 0; i < 36; ++i) { + if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-'); + else assert(isHexDigit(Uuid[i])); + } + + // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab". + const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 }; + + llvm::Constant *Field3[8]; + for (unsigned Idx = 0; Idx < 8; ++Idx) + Field3[Idx] = llvm::ConstantInt::get( + Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16); + + llvm::Constant *Fields[4] = { + llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16), + llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16), + llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16), + llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3) + }; + + return llvm::ConstantStruct::getAnon(Fields); +} + +llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty, + bool ForEH) { + // Return a bogus pointer if RTTI is disabled, unless it's for EH. + // FIXME: should we even be calling this method if RTTI is disabled + // and it's not for EH? + if (!ForEH && !getLangOpts().RTTI) + return llvm::Constant::getNullValue(Int8PtrTy); + + if (ForEH && Ty->isObjCObjectPointerType() && + LangOpts.ObjCRuntime.isGNUFamily()) + return ObjCRuntime->GetEHType(Ty); + + return getCXXABI().getAddrOfRTTIDescriptor(Ty); +} + +void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) { + for (auto RefExpr : D->varlists()) { + auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl()); + bool PerformInit = + VD->getAnyInitializer() && + !VD->getAnyInitializer()->isConstantInitializer(getContext(), + /*ForRef=*/false); + + Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD)); + if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition( + VD, Addr, RefExpr->getLocStart(), PerformInit)) + CXXGlobalInits.push_back(InitFunction); + } +} + +llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) { + llvm::Metadata *&InternalId = MetadataIdMap[T.getCanonicalType()]; + if (InternalId) + return InternalId; + + if (isExternallyVisible(T->getLinkage())) { + std::string OutName; + llvm::raw_string_ostream Out(OutName); + getCXXABI().getMangleContext().mangleTypeName(T, Out); + + InternalId = llvm::MDString::get(getLLVMContext(), Out.str()); + } else { + InternalId = llvm::MDNode::getDistinct(getLLVMContext(), + llvm::ArrayRef<llvm::Metadata *>()); + } + + return InternalId; +} + +void CodeGenModule::CreateVTableBitSetEntry(llvm::NamedMDNode *BitsetsMD, + llvm::GlobalVariable *VTable, + CharUnits Offset, + const CXXRecordDecl *RD) { + llvm::Metadata *MD = + CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0)); + llvm::Metadata *BitsetOps[] = { + MD, llvm::ConstantAsMetadata::get(VTable), + llvm::ConstantAsMetadata::get( + llvm::ConstantInt::get(Int64Ty, Offset.getQuantity()))}; + BitsetsMD->addOperand(llvm::MDTuple::get(getLLVMContext(), BitsetOps)); + + if (CodeGenOpts.SanitizeCfiCrossDso) { + if (auto TypeId = CreateCfiIdForTypeMetadata(MD)) { + llvm::Metadata *BitsetOps2[] = { + llvm::ConstantAsMetadata::get(TypeId), + llvm::ConstantAsMetadata::get(VTable), + llvm::ConstantAsMetadata::get( + llvm::ConstantInt::get(Int64Ty, Offset.getQuantity()))}; + BitsetsMD->addOperand(llvm::MDTuple::get(getLLVMContext(), BitsetOps2)); + } + } +} + +// Fills in the supplied string map with the set of target features for the +// passed in function. +void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap, + const FunctionDecl *FD) { + StringRef TargetCPU = Target.getTargetOpts().CPU; + if (const auto *TD = FD->getAttr<TargetAttr>()) { + // If we have a TargetAttr build up the feature map based on that. + TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse(); + + // Make a copy of the features as passed on the command line into the + // beginning of the additional features from the function to override. + ParsedAttr.first.insert(ParsedAttr.first.begin(), + Target.getTargetOpts().FeaturesAsWritten.begin(), + Target.getTargetOpts().FeaturesAsWritten.end()); + + if (ParsedAttr.second != "") + TargetCPU = ParsedAttr.second; + + // Now populate the feature map, first with the TargetCPU which is either + // the default or a new one from the target attribute string. Then we'll use + // the passed in features (FeaturesAsWritten) along with the new ones from + // the attribute. + Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, ParsedAttr.first); + } else { + Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, + Target.getTargetOpts().Features); + } +} |