text: //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // 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 "CGOpenMPRuntimeAMDGCN.h"
  #include "CGOpenMPRuntimeNVPTX.h"
  #include "CodeGenFunction.h"
  #include "CodeGenPGO.h"
  #include "ConstantEmitter.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/AST/StmtVisitor.h"
  #include "clang/Basic/Builtins.h"
  #include "clang/Basic/CharInfo.h"
  #include "clang/Basic/CodeGenOptions.h"
  #include "clang/Basic/Diagnostic.h"
  #include "clang/Basic/FileManager.h"
  #include "clang/Basic/Module.h"
  #include "clang/Basic/SourceManager.h"
  #include "clang/Basic/TargetInfo.h"
  #include "clang/Basic/Version.h"
  #include "clang/CodeGen/ConstantInitBuilder.h"
  #include "clang/Frontend/FrontendDiagnostic.h"
  #include "llvm/ADT/StringSwitch.h"
  #include "llvm/ADT/Triple.h"
  #include "llvm/Analysis/TargetLibraryInfo.h"
  #include "llvm/Frontend/OpenMP/OMPIRBuilder.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/IR/ProfileSummary.h"
  #include "llvm/ProfileData/InstrProfReader.h"
  #include "llvm/Support/CodeGen.h"
  #include "llvm/Support/CommandLine.h"
  #include "llvm/Support/ConvertUTF.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/MD5.h"
  #include "llvm/Support/TimeProfiler.h"
  #include "llvm/Support/X86TargetParser.h"
  
  using namespace clang;
  using namespace CodeGen;
  
  static llvm::cl::opt<bool> LimitedCoverage(
      "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
      llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
      llvm::cl::init(false));
  
  static const char AnnotationSection[] = "llvm.metadata";
  
  static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
    switch (CGM.getContext().getCXXABIKind()) {
    case TargetCXXABI::AppleARM64:
    case TargetCXXABI::Fuchsia:
    case TargetCXXABI::GenericAArch64:
    case TargetCXXABI::GenericARM:
    case TargetCXXABI::iOS:
    case TargetCXXABI::WatchOS:
    case TargetCXXABI::GenericMIPS:
    case TargetCXXABI::GenericItanium:
    case TargetCXXABI::WebAssembly:
    case TargetCXXABI::XL:
      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()), Types(*this), VTables(*this),
        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);
    HalfTy = llvm::Type::getHalfTy(LLVMContext);
    BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
    FloatTy = llvm::Type::getFloatTy(LLVMContext);
    DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
    PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
    PointerAlignInBytes =
      C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
    SizeSizeInBytes =
      C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
    IntAlignInBytes =
      C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
    CharTy =
      llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
    IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
    IntPtrTy = llvm::IntegerType::get(LLVMContext,
      C.getTargetInfo().getMaxPointerWidth());
    Int8PtrTy = Int8Ty->getPointerTo(0);
    Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
    const llvm::DataLayout &DL = M.getDataLayout();
    AllocaInt8PtrTy = Int8Ty->getPointerTo(DL.getAllocaAddrSpace());
    GlobalsInt8PtrTy = Int8Ty->getPointerTo(DL.getDefaultGlobalsAddressSpace());
    ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
  
    RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
  
    if (LangOpts.ObjC)
      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.reset(new CodeGenTBAA(Context, TheModule, 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.reset(new CGDebugInfo(*this));
  
    Block.GlobalUniqueCount = 0;
  
    if (C.getLangOpts().ObjC)
      ObjCData.reset(new ObjCEntrypoints());
  
    if (CodeGenOpts.hasProfileClangUse()) {
      auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
          CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
      if (auto E = ReaderOrErr.takeError()) {
        unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
                                                "Could not read profile %0: %1");
        llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
          getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
                                    << EI.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));
  
    // Generate the module name hash here if needed.
    if (CodeGenOpts.UniqueInternalLinkageNames &&
        !getModule().getSourceFileName().empty()) {
      std::string Path = getModule().getSourceFileName();
      // Check if a path substitution is needed from the MacroPrefixMap.
      for (const auto &Entry : LangOpts.MacroPrefixMap)
        if (Path.rfind(Entry.first, 0) != std::string::npos) {
          Path = Entry.second + Path.substr(Entry.first.size());
          break;
        }
      llvm::MD5 Md5;
      Md5.update(Path);
      llvm::MD5::MD5Result R;
      Md5.final(R);
      SmallString<32> Str;
      llvm::MD5::stringifyResult(R, Str);
      // Convert MD5hash to Decimal. Demangler suffixes can either contain
      // numbers or characters but not both.
      llvm::APInt IntHash(128, Str.str(), 16);
      // Prepend "__uniq" before the hash for tools like profilers to understand
      // that this symbol is of internal linkage type.  The "__uniq" is the
      // pre-determined prefix that is used to tell tools that this symbol was
      // created with -funique-internal-linakge-symbols and the tools can strip or
      // keep the prefix as needed.
      ModuleNameHash = (Twine(".__uniq.") +
          Twine(toString(IntHash, /* Radix = */ 10, /* Signed = */false))).str();
    }
  }
  
  CodeGenModule::~CodeGenModule() {}
  
  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.reset(CreateGNUObjCRuntime(*this));
      return;
  
    case ObjCRuntime::FragileMacOSX:
    case ObjCRuntime::MacOSX:
    case ObjCRuntime::iOS:
    case ObjCRuntime::WatchOS:
      ObjCRuntime.reset(CreateMacObjCRuntime(*this));
      return;
    }
    llvm_unreachable("bad runtime kind");
  }
  
  void CodeGenModule::createOpenCLRuntime() {
    OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
  }
  
  void CodeGenModule::createOpenMPRuntime() {
    // Select a specialized code generation class based on the target, if any.
    // If it does not exist use the default implementation.
    switch (getTriple().getArch()) {
    case llvm::Triple::nvptx:
    case llvm::Triple::nvptx64:
      assert(getLangOpts().OpenMPIsDevice &&
             "OpenMP NVPTX is only prepared to deal with device code.");
      OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
      break;
    case llvm::Triple::amdgcn:
      assert(getLangOpts().OpenMPIsDevice &&
             "OpenMP AMDGCN is only prepared to deal with device code.");
      OpenMPRuntime.reset(new CGOpenMPRuntimeAMDGCN(*this));
      break;
    default:
      if (LangOpts.OpenMPSimd)
        OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
      else
        OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
      break;
    }
  }
  
  void CodeGenModule::createCUDARuntime() {
    CUDARuntime.reset(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::GlobalIndirectSymbol &GIS) {
    llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
    const llvm::Constant *C = &GIS;
    for (;;) {
      C = C->stripPointerCasts();
      if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
        return GO;
      // stripPointerCasts will not walk over weak aliases.
      auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
      if (!GIS2)
        return nullptr;
      if (!Visited.insert(GIS2).second)
        return nullptr;
      C = GIS2->getIndirectSymbol();
    }
  }
  
  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());
      SourceLocation Location;
      bool IsIFunc = D->hasAttr<IFuncAttr>();
      if (const Attr *A = D->getDefiningAttr())
        Location = A->getLocation();
      else
        llvm_unreachable("Not an alias or ifunc?");
      StringRef MangledName = getMangledName(GD);
      llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
      auto *Alias  = cast<llvm::GlobalIndirectSymbol>(Entry);
      const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
      if (!GV) {
        Error = true;
        Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
      } else if (GV->isDeclaration()) {
        Error = true;
        Diags.Report(Location, diag::err_alias_to_undefined)
            << IsIFunc << IsIFunc;
      } else if (IsIFunc) {
        // Check resolver function type.
        llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
            GV->getType()->getPointerElementType());
        assert(FTy);
        if (!FTy->getReturnType()->isPointerTy())
          Diags.Report(Location, diag::err_ifunc_resolver_return);
      }
  
      llvm::Constant *Aliasee = Alias->getIndirectSymbol();
      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 << IsIFunc << IsIFunc;
      }
  
      // 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::GlobalIndirectSymbol>(AliaseeGV)) {
        if (GA->isInterposable()) {
          Diags.Report(Location, diag::warn_alias_to_weak_alias)
              << GV->getName() << GA->getName() << IsIFunc;
          Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
              GA->getIndirectSymbol(), Alias->getType());
          Alias->setIndirectSymbol(Aliasee);
        }
      }
    }
    if (!Error)
      return;
  
    for (const GlobalDecl &GD : Aliases) {
      StringRef MangledName = getMangledName(GD);
      llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
      auto *Alias = cast<llvm::GlobalIndirectSymbol>(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 {
      if (Mismatched > 0)
        Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
  
      if (Missing > 0)
        Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
    }
  }
  
  static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
                                               llvm::Module &M) {
    if (!LO.VisibilityFromDLLStorageClass)
      return;
  
    llvm::GlobalValue::VisibilityTypes DLLExportVisibility =
        CodeGenModule::GetLLVMVisibility(LO.getDLLExportVisibility());
    llvm::GlobalValue::VisibilityTypes NoDLLStorageClassVisibility =
        CodeGenModule::GetLLVMVisibility(LO.getNoDLLStorageClassVisibility());
    llvm::GlobalValue::VisibilityTypes ExternDeclDLLImportVisibility =
        CodeGenModule::GetLLVMVisibility(LO.getExternDeclDLLImportVisibility());
    llvm::GlobalValue::VisibilityTypes ExternDeclNoDLLStorageClassVisibility =
        CodeGenModule::GetLLVMVisibility(
            LO.getExternDeclNoDLLStorageClassVisibility());
  
    for (llvm::GlobalValue &GV : M.global_values()) {
      if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
        continue;
  
      // Reset DSO locality before setting the visibility. This removes
      // any effects that visibility options and annotations may have
      // had on the DSO locality. Setting the visibility will implicitly set
      // appropriate globals to DSO Local; however, this will be pessimistic
      // w.r.t. to the normal compiler IRGen.
      GV.setDSOLocal(false);
  
      if (GV.isDeclarationForLinker()) {
        GV.setVisibility(GV.getDLLStorageClass() ==
                                 llvm::GlobalValue::DLLImportStorageClass
                             ? ExternDeclDLLImportVisibility
                             : ExternDeclNoDLLStorageClassVisibility);
      } else {
        GV.setVisibility(GV.getDLLStorageClass() ==
                                 llvm::GlobalValue::DLLExportStorageClass
                             ? DLLExportVisibility
                             : NoDLLStorageClassVisibility);
      }
  
      GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
    }
  }
  
  void CodeGenModule::Release() {
    EmitDeferred();
    EmitVTablesOpportunistically();
    applyGlobalValReplacements();
    applyReplacements();
    checkAliases();
    emitMultiVersionFunctions();
    EmitCXXGlobalInitFunc();
    EmitCXXGlobalCleanUpFunc();
    registerGlobalDtorsWithAtExit();
    EmitCXXThreadLocalInitFunc();
    if (ObjCRuntime)
      if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
        AddGlobalCtor(ObjCInitFunction);
    if (Context.getLangOpts().CUDA && CUDARuntime) {
      if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
        AddGlobalCtor(CudaCtorFunction);
    }
    if (OpenMPRuntime) {
      if (llvm::Function *OpenMPRequiresDirectiveRegFun =
              OpenMPRuntime->emitRequiresDirectiveRegFun()) {
        AddGlobalCtor(OpenMPRequiresDirectiveRegFun, 0);
      }
      OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
      OpenMPRuntime->clear();
    }
    if (PGOReader) {
      getModule().setProfileSummary(
          PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
          llvm::ProfileSummary::PSK_Instr);
      if (PGOStats.hasDiagnostics())
        PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
    }
    EmitCtorList(GlobalCtors, "llvm.global_ctors");
    EmitCtorList(GlobalDtors, "llvm.global_dtors");
    EmitGlobalAnnotations();
    EmitStaticExternCAliases();
    EmitDeferredUnusedCoverageMappings();
    CodeGenPGO(*this).setValueProfilingFlag(getModule());
    if (CoverageMapping)
      CoverageMapping->emit();
    if (CodeGenOpts.SanitizeCfiCrossDso) {
      CodeGenFunction(*this).EmitCfiCheckFail();
      CodeGenFunction(*this).EmitCfiCheckStub();
    }
    emitAtAvailableLinkGuard();
    if (Context.getTargetInfo().getTriple().isWasm() &&
        !Context.getTargetInfo().getTriple().isOSEmscripten()) {
      EmitMainVoidAlias();
    }
  
    // Emit reference of __amdgpu_device_library_preserve_asan_functions to
    // preserve ASAN functions in bitcode libraries.
    if (LangOpts.Sanitize.has(SanitizerKind::Address) && getTriple().isAMDGPU()) {
      auto *FT = llvm::FunctionType::get(VoidTy, {});
      auto *F = llvm::Function::Create(
          FT, llvm::GlobalValue::ExternalLinkage,
          "__amdgpu_device_library_preserve_asan_functions", &getModule());
      auto *Var = new llvm::GlobalVariable(
          getModule(), FT->getPointerTo(),
          /*isConstant=*/true, llvm::GlobalValue::WeakAnyLinkage, F,
          "__amdgpu_device_library_preserve_asan_functions_ptr", nullptr,
          llvm::GlobalVariable::NotThreadLocal);
      addCompilerUsedGlobal(Var);
    }
  
    emitLLVMUsed();
    if (SanStats)
      SanStats->finish();
  
    if (CodeGenOpts.Autolink &&
        (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
      EmitModuleLinkOptions();
    }
  
    // On ELF we pass the dependent library specifiers directly to the linker
    // without manipulating them. This is in contrast to other platforms where
    // they are mapped to a specific linker option by the compiler. This
    // difference is a result of the greater variety of ELF linkers and the fact
    // that ELF linkers tend to handle libraries in a more complicated fashion
    // than on other platforms. This forces us to defer handling the dependent
    // libs to the linker.
    //
    // CUDA/HIP device and host libraries are different. Currently there is no
    // way to differentiate dependent libraries for host or device. Existing
    // usage of #pragma comment(lib, *) is intended for host libraries on
    // Windows. Therefore emit llvm.dependent-libraries only for host.
    if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
      auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
      for (auto *MD : ELFDependentLibraries)
        NMD->addOperand(MD);
    }
  
    // Record mregparm value now so it is visible through rest of codegen.
    if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
      getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
                                CodeGenOpts.NumRegisterParameters);
  
    if (CodeGenOpts.DwarfVersion) {
      getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
                                CodeGenOpts.DwarfVersion);
    }
  
    if (CodeGenOpts.Dwarf64)
      getModule().addModuleFlag(llvm::Module::Max, "DWARF64", 1);
  
    if (Context.getLangOpts().SemanticInterposition)
      // Require various optimization to respect semantic interposition.
      getModule().setSemanticInterposition(1);
  
    if (CodeGenOpts.EmitCodeView) {
      // Indicate that we want CodeView in the metadata.
      getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
    }
    if (CodeGenOpts.CodeViewGHash) {
      getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
    }
    if (CodeGenOpts.ControlFlowGuard) {
      // Function ID tables and checks for Control Flow Guard (cfguard=2).
      getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
    } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
      // Function ID tables for Control Flow Guard (cfguard=1).
      getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
    }
    if (CodeGenOpts.EHContGuard) {
      // Function ID tables for EH Continuation Guard.
      getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 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 (getModuleDebugInfo())
      // 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. wchar_size is also used by
    // TargetLibraryInfo.
    uint64_t WCharWidth =
        Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
    getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
  
    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) {
      // 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 (Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64) {
      StringRef ABIStr = Target.getABI();
      llvm::LLVMContext &Ctx = TheModule.getContext();
      getModule().addModuleFlag(llvm::Module::Error, "target-abi",
                                llvm::MDString::get(Ctx, ABIStr));
    }
  
    if (CodeGenOpts.SanitizeCfiCrossDso) {
      // Indicate that we want cross-DSO control flow integrity checks.
      getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
    }
  
    if (CodeGenOpts.WholeProgramVTables) {
      // Indicate whether VFE was enabled for this module, so that the
      // vcall_visibility metadata added under whole program vtables is handled
      // appropriately in the optimizer.
      getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
                                CodeGenOpts.VirtualFunctionElimination);
    }
  
    if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
      getModule().addModuleFlag(llvm::Module::Override,
                                "CFI Canonical Jump Tables",
                                CodeGenOpts.SanitizeCfiCanonicalJumpTables);
    }
  
    if (CodeGenOpts.CFProtectionReturn &&
        Target.checkCFProtectionReturnSupported(getDiags())) {
      // Indicate that we want to instrument return control flow protection.
      getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
                                1);
    }
  
    if (CodeGenOpts.CFProtectionBranch &&
        Target.checkCFProtectionBranchSupported(getDiags())) {
      // Indicate that we want to instrument branch control flow protection.
      getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
                                1);
    }
  
    if (Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_32 ||
        Arch == llvm::Triple::aarch64_be) {
      getModule().addModuleFlag(llvm::Module::Error,
                                "branch-target-enforcement",
                                LangOpts.BranchTargetEnforcement);
  
      getModule().addModuleFlag(llvm::Module::Error, "sign-return-address",
                                LangOpts.hasSignReturnAddress());
  
      getModule().addModuleFlag(llvm::Module::Error, "sign-return-address-all",
                                LangOpts.isSignReturnAddressScopeAll());
  
      getModule().addModuleFlag(llvm::Module::Error,
                                "sign-return-address-with-bkey",
                                !LangOpts.isSignReturnAddressWithAKey());
    }
  
    if (!CodeGenOpts.MemoryProfileOutput.empty()) {
      llvm::LLVMContext &Ctx = TheModule.getContext();
      getModule().addModuleFlag(
          llvm::Module::Error, "MemProfProfileFilename",
          llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
    }
  
    if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
      // Indicate whether __nvvm_reflect should be configured to flush denormal
      // floating point values to 0.  (This corresponds to its "__CUDA_FTZ"
      // property.)
      getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
                                CodeGenOpts.FP32DenormalMode.Output !=
                                    llvm::DenormalMode::IEEE);
    }
  
    if (LangOpts.EHAsynch)
      getModule().addModuleFlag(llvm::Module::Warning, "eh-asynch", 1);
  
    // Indicate whether this Module was compiled with -fopenmp
    if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
      getModule().addModuleFlag(llvm::Module::Max, "openmp", LangOpts.OpenMP);
    if (getLangOpts().OpenMPIsDevice)
      getModule().addModuleFlag(llvm::Module::Max, "openmp-device",
                                LangOpts.OpenMP);
  
    // Emit OpenCL specific module metadata: OpenCL/SPIR version.
    if (LangOpts.OpenCL) {
      EmitOpenCLMetadata();
      // Emit SPIR version.
      if (getTriple().isSPIR()) {
        // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
        // opencl.spir.version named metadata.
        // C++ for OpenCL has a distinct mapping for version compatibility with
        // OpenCL.
        auto Version = LangOpts.getOpenCLCompatibleVersion();
        llvm::Metadata *SPIRVerElts[] = {
            llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
                Int32Ty, Version / 100)),
            llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
                Int32Ty, (Version / 100 > 1) ? 0 : 2))};
        llvm::NamedMDNode *SPIRVerMD =
            TheModule.getOrInsertNamedMetadata("opencl.spir.version");
        llvm::LLVMContext &Ctx = TheModule.getContext();
        SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
      }
    }
  
    if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
      assert(PLevel < 3 && "Invalid PIC Level");
      getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
      if (Context.getLangOpts().PIE)
        getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
    }
  
    if (getCodeGenOpts().CodeModel.size() > 0) {
      unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
                    .Case("tiny", llvm::CodeModel::Tiny)
                    .Case("small", llvm::CodeModel::Small)
                    .Case("kernel", llvm::CodeModel::Kernel)
                    .Case("medium", llvm::CodeModel::Medium)
                    .Case("large", llvm::CodeModel::Large)
                    .Default(~0u);
      if (CM != ~0u) {
        llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
        getModule().setCodeModel(codeModel);
      }
    }
  
    if (CodeGenOpts.NoPLT)
      getModule().setRtLibUseGOT();
    if (CodeGenOpts.UnwindTables)
      getModule().setUwtable();
  
    switch (CodeGenOpts.getFramePointer()) {
    case CodeGenOptions::FramePointerKind::None:
      // 0 ("none") is the default.
      break;
    case CodeGenOptions::FramePointerKind::NonLeaf:
      getModule().setFramePointer(llvm::FramePointerKind::NonLeaf);
      break;
    case CodeGenOptions::FramePointerKind::All:
      getModule().setFramePointer(llvm::FramePointerKind::All);
      break;
    }
  
    SimplifyPersonality();
  
    if (getCodeGenOpts().EmitDeclMetadata)
      EmitDeclMetadata();
  
    if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
      EmitCoverageFile();
  
    if (CGDebugInfo *DI = getModuleDebugInfo())
      DI->finalize();
  
    if (getCodeGenOpts().EmitVersionIdentMetadata)
      EmitVersionIdentMetadata();
  
    if (!getCodeGenOpts().RecordCommandLine.empty())
      EmitCommandLineMetadata();
  
    if (!getCodeGenOpts().StackProtectorGuard.empty())
      getModule().setStackProtectorGuard(getCodeGenOpts().StackProtectorGuard);
    if (!getCodeGenOpts().StackProtectorGuardReg.empty())
      getModule().setStackProtectorGuardReg(
          getCodeGenOpts().StackProtectorGuardReg);
    if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
      getModule().setStackProtectorGuardOffset(
          getCodeGenOpts().StackProtectorGuardOffset);
    if (getCodeGenOpts().StackAlignment)
      getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
  
    getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
  
    EmitBackendOptionsMetadata(getCodeGenOpts());
  
    // Set visibility from DLL storage class
    // We do this at the end of LLVM IR generation; after any operation
    // that might affect the DLL storage class or the visibility, and
    // before anything that might act on these.
    setVisibilityFromDLLStorageClass(LangOpts, getModule());
  }
  
  void CodeGenModule::EmitOpenCLMetadata() {
    // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
    // opencl.ocl.version named metadata node.
    // C++ for OpenCL has a distinct mapping for versions compatibile with OpenCL.
    auto Version = LangOpts.getOpenCLCompatibleVersion();
    llvm::Metadata *OCLVerElts[] = {
        llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
            Int32Ty, Version / 100)),
        llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
            Int32Ty, (Version % 100) / 10))};
    llvm::NamedMDNode *OCLVerMD =
        TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
    llvm::LLVMContext &Ctx = TheModule.getContext();
    OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
  }
  
  void CodeGenModule::EmitBackendOptionsMetadata(
      const CodeGenOptions CodeGenOpts) {
    switch (getTriple().getArch()) {
    default:
      break;
    case llvm::Triple::riscv32:
    case llvm::Triple::riscv64:
      getModule().addModuleFlag(llvm::Module::Error, "SmallDataLimit",
                                CodeGenOpts.SmallDataLimit);
      break;
    }
  }
  
  void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
    // Make sure that this type is translated.
    Types.UpdateCompletedType(TD);
  }
  
  void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
    // Make sure that this type is translated.
    Types.RefreshTypeCacheForClass(RD);
  }
  
  llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
    if (!TBAA)
      return nullptr;
    return TBAA->getTypeInfo(QTy);
  }
  
  TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
    if (!TBAA)
      return TBAAAccessInfo();
    if (getLangOpts().CUDAIsDevice) {
      // As CUDA builtin surface/texture types are replaced, skip generating TBAA
      // access info.
      if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
        if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
            nullptr)
          return TBAAAccessInfo();
      } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
        if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
            nullptr)
          return TBAAAccessInfo();
      }
    }
    return TBAA->getAccessInfo(AccessType);
  }
  
  TBAAAccessInfo
  CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
    if (!TBAA)
      return TBAAAccessInfo();
    return TBAA->getVTablePtrAccessInfo(VTablePtrType);
  }
  
  llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
    if (!TBAA)
      return nullptr;
    return TBAA->getTBAAStructInfo(QTy);
  }
  
  llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
    if (!TBAA)
      return nullptr;
    return TBAA->getBaseTypeInfo(QTy);
  }
  
  llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
    if (!TBAA)
      return nullptr;
    return TBAA->getAccessTagInfo(Info);
  }
  
  TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
                                                     TBAAAccessInfo TargetInfo) {
    if (!TBAA)
      return TBAAAccessInfo();
    return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
  }
  
  TBAAAccessInfo
  CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
                                                     TBAAAccessInfo InfoB) {
    if (!TBAA)
      return TBAAAccessInfo();
    return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
  }
  
  TBAAAccessInfo
  CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
                                                TBAAAccessInfo SrcInfo) {
    if (!TBAA)
      return TBAAAccessInfo();
    return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
  }
  
  void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
                                                  TBAAAccessInfo TBAAInfo) {
    if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
      Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
  }
  
  void CodeGenModule::DecorateInstructionWithInvariantGroup(
      llvm::Instruction *I, const CXXRecordDecl *RD) {
    I->setMetadata(llvm::LLVMContext::MD_invariant_group,
                   llvm::MDNode::get(getLLVMContext(), {}));
  }
  
  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->getBeginLoc()), 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 {
    if (GV->hasDLLImportStorageClass())
      return;
    // Internal definitions always have default visibility.
    if (GV->hasLocalLinkage()) {
      GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
      return;
    }
    if (!D)
      return;
    // Set visibility for definitions, and for declarations if requested globally
    // or set explicitly.
    LinkageInfo LV = D->getLinkageAndVisibility();
    if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
        !GV->isDeclarationForLinker())
      GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
  }
  
  static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
                                   llvm::GlobalValue *GV) {
    if (GV->hasLocalLinkage())
      return true;
  
    if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
      return true;
  
    // DLLImport explicitly marks the GV as external.
    if (GV->hasDLLImportStorageClass())
      return false;
  
    const llvm::Triple &TT = CGM.getTriple();
    if (TT.isWindowsGNUEnvironment()) {
      // In MinGW, variables without DLLImport can still be automatically
      // imported from a DLL by the linker; don't mark variables that
      // potentially could come from another DLL as DSO local.
  
      // With EmulatedTLS, TLS variables can be autoimported from other DLLs
      // (and this actually happens in the public interface of libstdc++), so
      // such variables can't be marked as DSO local. (Native TLS variables
      // can't be dllimported at all, though.)
      if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
          (!GV->isThreadLocal() || CGM.getCodeGenOpts().EmulatedTLS))
        return false;
    }
  
    // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
    // remain unresolved in the link, they can be resolved to zero, which is
    // outside the current DSO.
    if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
      return false;
  
    // Every other GV is local on COFF.
    // Make an exception for windows OS in the triple: Some firmware builds use
    // *-win32-macho triples. This (accidentally?) produced windows relocations
    // without GOT tables in older clang versions; Keep this behaviour.
    // FIXME: even thread local variables?
    if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
      return true;
  
    // Only handle COFF and ELF for now.
    if (!TT.isOSBinFormatELF())
      return false;
  
    // If this is not an executable, don't assume anything is local.
    const auto &CGOpts = CGM.getCodeGenOpts();
    llvm::Reloc::Model RM = CGOpts.RelocationModel;
    const auto &LOpts = CGM.getLangOpts();
    if (RM != llvm::Reloc::Static && !LOpts.PIE) {
      // On ELF, if -fno-semantic-interposition is specified and the target
      // supports local aliases, there will be neither CC1
      // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
      // dso_local on the function if using a local alias is preferable (can avoid
      // PLT indirection).
      if (!(isa<llvm::Function>(GV) && GV->canBenefitFromLocalAlias()))
        return false;
      return !(CGM.getLangOpts().SemanticInterposition ||
               CGM.getLangOpts().HalfNoSemanticInterposition);
    }
  
    // A definition cannot be preempted from an executable.
    if (!GV->isDeclarationForLinker())
      return true;
  
    // Most PIC code sequences that assume that a symbol is local cannot produce a
    // 0 if it turns out the symbol is undefined. While this is ABI and relocation
    // depended, it seems worth it to handle it here.
    if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
      return false;
  
    // PowerPC64 prefers TOC indirection to avoid copy relocations.
    if (TT.isPPC64())
      return false;
  
    if (CGOpts.DirectAccessExternalData) {
      // If -fdirect-access-external-data (default for -fno-pic), set dso_local
      // for non-thread-local variables. If the symbol is not defined in the
      // executable, a copy relocation will be needed at link time. dso_local is
      // excluded for thread-local variables because they generally don't support
      // copy relocations.
      if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
        if (!Var->isThreadLocal())
          return true;
  
      // -fno-pic sets dso_local on a function declaration to allow direct
      // accesses when taking its address (similar to a data symbol). If the
      // function is not defined in the executable, a canonical PLT entry will be
      // needed at link time. -fno-direct-access-external-data can avoid the
      // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
      // it could just cause trouble without providing perceptible benefits.
      if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
        return true;
    }
  
    // If we can use copy relocations we can assume it is local.
  
    // Otherwise don't assume it is local.
    return false;
  }
  
  void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
    GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
  }
  
  void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
                                            GlobalDecl GD) const {
    const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
    // C++ destructors have a few C++ ABI specific special cases.
    if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
      getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
      return;
    }
    setDLLImportDLLExport(GV, D);
  }
  
  void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
                                            const NamedDecl *D) const {
    if (D && D->isExternallyVisible()) {
      if (D->hasAttr<DLLImportAttr>())
        GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
      else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
        GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
    }
  }
  
  void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
                                      GlobalDecl GD) const {
    setDLLImportDLLExport(GV, GD);
    setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
  }
  
  void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
                                      const NamedDecl *D) const {
    setDLLImportDLLExport(GV, D);
    setGVPropertiesAux(GV, D);
  }
  
  void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
                                         const NamedDecl *D) const {
    setGlobalVisibility(GV, D);
    setDSOLocal(GV);
    GV->setPartition(CodeGenOpts.SymbolPartition);
  }
  
  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);
  }
  
  llvm::GlobalVariable::ThreadLocalMode
  CodeGenModule::GetDefaultLLVMTLSModel() const {
    switch (CodeGenOpts.getDefaultTLSModel()) {
    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 = GetDefaultLLVMTLSModel();
  
    // Override the TLS model if it is explicitly specified.
    if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
      TLM = GetLLVMTLSModel(Attr->getModel());
    }
  
    GV->setThreadLocalMode(TLM);
  }
  
  static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
                                            StringRef Name) {
    const TargetInfo &Target = CGM.getTarget();
    return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
  }
  
  static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
                                                   const CPUSpecificAttr *Attr,
                                                   unsigned CPUIndex,
                                                   raw_ostream &Out) {
    // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
    // supported.
    if (Attr)
      Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
    else if (CGM.getTarget().supportsIFunc())
      Out << ".resolver";
  }
  
  static void AppendTargetMangling(const CodeGenModule &CGM,
                                   const TargetAttr *Attr, raw_ostream &Out) {
    if (Attr->isDefaultVersion())
      return;
  
    Out << '.';
    const TargetInfo &Target = CGM.getTarget();
    ParsedTargetAttr Info =
        Attr->parse([&Target](StringRef LHS, StringRef RHS) {
          // Multiversioning doesn't allow "no-${feature}", so we can
          // only have "+" prefixes here.
          assert(LHS.startswith("+") && RHS.startswith("+") &&
                 "Features should always have a prefix.");
          return Target.multiVersionSortPriority(LHS.substr(1)) >
                 Target.multiVersionSortPriority(RHS.substr(1));
        });
  
    bool IsFirst = true;
  
    if (!Info.Architecture.empty()) {
      IsFirst = false;
      Out << "arch_" << Info.Architecture;
    }
  
    for (StringRef Feat : Info.Features) {
      if (!IsFirst)
        Out << '_';
      IsFirst = false;
      Out << Feat.substr(1);
    }
  }
  
  // Returns true if GD is a function decl with internal linkage and
  // needs a unique suffix after the mangled name.
  static bool isUniqueInternalLinkageDecl(GlobalDecl GD,
                                          CodeGenModule &CGM) {
    const Decl *D = GD.getDecl();
    return !CGM.getModuleNameHash().empty() && isa<FunctionDecl>(D) &&
           (CGM.getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage);
  }
  
  static std::string getMangledNameImpl(CodeGenModule &CGM, GlobalDecl GD,
                                        const NamedDecl *ND,
                                        bool OmitMultiVersionMangling = false) {
    SmallString<256> Buffer;
    llvm::raw_svector_ostream Out(Buffer);
    MangleContext &MC = CGM.getCXXABI().getMangleContext();
    if (!CGM.getModuleNameHash().empty())
      MC.needsUniqueInternalLinkageNames();
    bool ShouldMangle = MC.shouldMangleDeclName(ND);
    if (ShouldMangle)
      MC.mangleName(GD.getWithDecl(ND), Out);
    else {
      IdentifierInfo *II = ND->getIdentifier();
      assert(II && "Attempt to mangle unnamed decl.");
      const auto *FD = dyn_cast<FunctionDecl>(ND);
  
      if (FD &&
          FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
        Out << "__regcall3__" << II->getName();
      } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
                 GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
        Out << "__device_stub__" << II->getName();
      } else {
        Out << II->getName();
      }
    }
  
    // Check if the module name hash should be appended for internal linkage
    // symbols.   This should come before multi-version target suffixes are
    // appended. This is to keep the name and module hash suffix of the
    // internal linkage function together.  The unique suffix should only be
    // added when name mangling is done to make sure that the final name can
    // be properly demangled.  For example, for C functions without prototypes,
    // name mangling is not done and the unique suffix should not be appeneded
    // then.
    if (ShouldMangle && isUniqueInternalLinkageDecl(GD, CGM)) {
      assert(CGM.getCodeGenOpts().UniqueInternalLinkageNames &&
             "Hash computed when not explicitly requested");
      Out << CGM.getModuleNameHash();
    }
  
    if (const auto *FD = dyn_cast<FunctionDecl>(ND))
      if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
        switch (FD->getMultiVersionKind()) {
        case MultiVersionKind::CPUDispatch:
        case MultiVersionKind::CPUSpecific:
          AppendCPUSpecificCPUDispatchMangling(CGM,
                                               FD->getAttr<CPUSpecificAttr>(),
                                               GD.getMultiVersionIndex(), Out);
          break;
        case MultiVersionKind::Target:
          AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
          break;
        case MultiVersionKind::None:
          llvm_unreachable("None multiversion type isn't valid here");
        }
      }
  
    // Make unique name for device side static file-scope variable for HIP.
    if (CGM.getContext().shouldExternalizeStaticVar(ND) &&
        CGM.getLangOpts().GPURelocatableDeviceCode &&
        CGM.getLangOpts().CUDAIsDevice && !CGM.getLangOpts().CUID.empty())
      CGM.printPostfixForExternalizedStaticVar(Out);
    return std::string(Out.str());
  }
  
  void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
                                              const FunctionDecl *FD) {
    if (!FD->isMultiVersion())
      return;
  
    // Get the name of what this would be without the 'target' attribute.  This
    // allows us to lookup the version that was emitted when this wasn't a
    // multiversion function.
    std::string NonTargetName =
        getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
    GlobalDecl OtherGD;
    if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
      assert(OtherGD.getCanonicalDecl()
                 .getDecl()
                 ->getAsFunction()
                 ->isMultiVersion() &&
             "Other GD should now be a multiversioned function");
      // OtherFD is the version of this function that was mangled BEFORE
      // becoming a MultiVersion function.  It potentially needs to be updated.
      const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
                                        .getDecl()
                                        ->getAsFunction()
                                        ->getMostRecentDecl();
      std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
      // This is so that if the initial version was already the 'default'
      // version, we don't try to update it.
      if (OtherName != NonTargetName) {
        // Remove instead of erase, since others may have stored the StringRef
        // to this.
        const auto ExistingRecord = Manglings.find(NonTargetName);
        if (ExistingRecord != std::end(Manglings))
          Manglings.remove(&(*ExistingRecord));
        auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
        MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
        if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
          Entry->setName(OtherName);
      }
    }
  }
  
  StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
    GlobalDecl CanonicalGD = GD.getCanonicalDecl();
  
    // Some ABIs don't have constructor variants.  Make sure that base and
    // complete constructors get mangled the same.
    if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
      if (!getTarget().getCXXABI().hasConstructorVariants()) {
        CXXCtorType OrigCtorType = GD.getCtorType();
        assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
        if (OrigCtorType == Ctor_Base)
          CanonicalGD = GlobalDecl(CD, Ctor_Complete);
      }
    }
  
    // In CUDA/HIP device compilation with -fgpu-rdc, the mangled name of a
    // static device variable depends on whether the variable is referenced by
    // a host or device host function. Therefore the mangled name cannot be
    // cached.
    if (!LangOpts.CUDAIsDevice ||
        !getContext().mayExternalizeStaticVar(GD.getDecl())) {
      auto FoundName = MangledDeclNames.find(CanonicalGD);
      if (FoundName != MangledDeclNames.end())
        return FoundName->second;
    }
  
    // Keep the first result in the case of a mangling collision.
    const auto *ND = cast<NamedDecl>(GD.getDecl());
    std::string MangledName = getMangledNameImpl(*this, GD, ND);
  
    // Ensure either we have different ABIs between host and device compilations,
    // says host compilation following MSVC ABI but device compilation follows
    // Itanium C++ ABI or, if they follow the same ABI, kernel names after
    // mangling should be the same after name stubbing. The later checking is
    // very important as the device kernel name being mangled in host-compilation
    // is used to resolve the device binaries to be executed. Inconsistent naming
    // result in undefined behavior. Even though we cannot check that naming
    // directly between host- and device-compilations, the host- and
    // device-mangling in host compilation could help catching certain ones.
    assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
           getLangOpts().CUDAIsDevice ||
           (getContext().getAuxTargetInfo() &&
            (getContext().getAuxTargetInfo()->getCXXABI() !=
             getContext().getTargetInfo().getCXXABI())) ||
           getCUDARuntime().getDeviceSideName(ND) ==
               getMangledNameImpl(
                   *this,
                   GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
                   ND));
  
    auto Result = Manglings.insert(std::make_pair(MangledName, GD));
    return MangledDeclNames[CanonicalGD] = 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,
                                    bool IsDtorAttrFunc) {
    if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
        (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
      DtorsUsingAtExit[Priority].push_back(Dtor);
      return;
    }
  
    // FIXME: Type coercion of void()* types.
    GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
  }
  
  void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
    if (Fns.empty()) return;
  
    // Ctor function type is void()*.
    llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
    llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
        TheModule.getDataLayout().getProgramAddressSpace());
  
    // Get the type of a ctor entry, { i32, void ()*, i8* }.
    llvm::StructType *CtorStructTy = llvm::StructType::get(
        Int32Ty, CtorPFTy, VoidPtrTy);
  
    // Construct the constructor and destructor arrays.
    ConstantInitBuilder builder(*this);
    auto ctors = builder.beginArray(CtorStructTy);
    for (const auto &I : Fns) {
      auto ctor = ctors.beginStruct(CtorStructTy);
      ctor.addInt(Int32Ty, I.Priority);
      ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
      if (I.AssociatedData)
        ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
      else
        ctor.addNullPointer(VoidPtrTy);
      ctor.finishAndAddTo(ctors);
    }
  
    auto list =
      ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
                                  /*constant*/ false,
                                  llvm::GlobalValue::AppendingLinkage);
  
    // The LTO linker doesn't seem to like it when we set an alignment
    // on appending variables.  Take it off as a workaround.
    list->setAlignment(llvm::None);
  
    Fns.clear();
  }
  
  llvm::GlobalValue::LinkageTypes
  CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
    const auto *D = cast<FunctionDecl>(GD.getDecl());
  
    GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
  
    if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
      return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
  
    if (isa<CXXConstructorDecl>(D) &&
        cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
        Context.getTargetInfo().getCXXABI().isMicrosoft()) {
      // Our approach to inheriting constructors is fundamentally different from
      // that used by the MS ABI, so keep our inheriting constructor thunks
      // internal rather than trying to pick an unambiguous mangling for them.
      return llvm::GlobalValue::InternalLinkage;
    }
  
    return getLLVMLinkageForDeclarator(D, Linkage, /*IsConstantVariable=*/false);
  }
  
  llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
    llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
    if (!MDS) return nullptr;
  
    return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
  }
  
  void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
                                                const CGFunctionInfo &Info,
                                                llvm::Function *F, bool IsThunk) {
    unsigned CallingConv;
    llvm::AttributeList PAL;
    ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
                           /*AttrOnCallSite=*/false, IsThunk);
    F->setAttributes(PAL);
    F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
  }
  
  static void removeImageAccessQualifier(std::string& TyName) {
    std::string ReadOnlyQual("__read_only");
    std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
    if (ReadOnlyPos != std::string::npos)
      // "+ 1" for the space after access qualifier.
      TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
    else {
      std::string WriteOnlyQual("__write_only");
      std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
      if (WriteOnlyPos != std::string::npos)
        TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
      else {
        std::string ReadWriteQual("__read_write");
        std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
        if (ReadWritePos != std::string::npos)
          TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
      }
    }
  }
  
  // Returns the address space id that should be produced to the
  // kernel_arg_addr_space metadata. This is always fixed to the ids
  // as specified in the SPIR 2.0 specification in order to differentiate
  // for example in clGetKernelArgInfo() implementation between the address
  // spaces with targets without unique mapping to the OpenCL address spaces
  // (basically all single AS CPUs).
  static unsigned ArgInfoAddressSpace(LangAS AS) {
    switch (AS) {
    case LangAS::opencl_global:
      return 1;
    case LangAS::opencl_constant:
      return 2;
    case LangAS::opencl_local:
      return 3;
    case LangAS::opencl_generic:
      return 4; // Not in SPIR 2.0 specs.
    case LangAS::opencl_global_device:
      return 5;
    case LangAS::opencl_global_host:
      return 6;
    default:
      return 0; // Assume private.
    }
  }
  
  void CodeGenModule::GenOpenCLArgMetadata(llvm::Function *Fn,
                                           const FunctionDecl *FD,
                                           CodeGenFunction *CGF) {
    assert(((FD && CGF) || (!FD && !CGF)) &&
           "Incorrect use - FD and CGF should either be both null or not!");
    // Create MDNodes that represent the kernel arg metadata.
    // Each MDNode is a list in the form of "key", N number of values which is
    // the same number of values as their are kernel arguments.
  
    const PrintingPolicy &Policy = Context.getPrintingPolicy();
  
    // MDNode for the kernel argument address space qualifiers.
    SmallVector<llvm::Metadata *, 8> addressQuals;
  
    // MDNode for the kernel argument access qualifiers (images only).
    SmallVector<llvm::Metadata *, 8> accessQuals;
  
    // MDNode for the kernel argument type names.
    SmallVector<llvm::Metadata *, 8> argTypeNames;
  
    // MDNode for the kernel argument base type names.
    SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
  
    // MDNode for the kernel argument type qualifiers.
    SmallVector<llvm::Metadata *, 8> argTypeQuals;
  
    // MDNode for the kernel argument names.
    SmallVector<llvm::Metadata *, 8> argNames;
  
    if (FD && CGF)
      for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
        const ParmVarDecl *parm = FD->getParamDecl(i);
        QualType ty = parm->getType();
        std::string typeQuals;
  
        // Get image and pipe access qualifier:
        if (ty->isImageType() || ty->isPipeType()) {
          const Decl *PDecl = parm;
          if (auto *TD = dyn_cast<TypedefType>(ty))
            PDecl = TD->getDecl();
          const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
          if (A && A->isWriteOnly())
            accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
          else if (A && A->isReadWrite())
            accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
          else
            accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
        } else
          accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
  
        // Get argument name.
        argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
  
        auto getTypeSpelling = [&](QualType Ty) {
          auto typeName = Ty.getUnqualifiedType().getAsString(Policy);
  
          if (Ty.isCanonical()) {
            StringRef typeNameRef = typeName;
            // Turn "unsigned type" to "utype"
            if (typeNameRef.consume_front("unsigned "))
              return std::string("u") + typeNameRef.str();
            if (typeNameRef.consume_front("signed "))
              return typeNameRef.str();
          }
  
          return typeName;
        };
  
        if (ty->isPointerType()) {
          QualType pointeeTy = ty->getPointeeType();
  
          // Get address qualifier.
          addressQuals.push_back(
              llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
                  ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
  
          // Get argument type name.
          std::string typeName = getTypeSpelling(pointeeTy) + "*";
          std::string baseTypeName =
              getTypeSpelling(pointeeTy.getCanonicalType()) + "*";
          argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
          argBaseTypeNames.push_back(
              llvm::MDString::get(VMContext, baseTypeName));
  
          // Get argument type qualifiers:
          if (ty.isRestrictQualified())
            typeQuals = "restrict";
          if (pointeeTy.isConstQualified() ||
              (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
            typeQuals += typeQuals.empty() ? "const" : " const";
          if (pointeeTy.isVolatileQualified())
            typeQuals += typeQuals.empty() ? "volatile" : " volatile";
        } else {
          uint32_t AddrSpc = 0;
          bool isPipe = ty->isPipeType();
          if (ty->isImageType() || isPipe)
            AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
  
          addressQuals.push_back(
              llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
  
          // Get argument type name.
          ty = isPipe ? ty->castAs<PipeType>()->getElementType() : ty;
          std::string typeName = getTypeSpelling(ty);
          std::string baseTypeName = getTypeSpelling(ty.getCanonicalType());
  
          // Remove access qualifiers on images
          // (as they are inseparable from type in clang implementation,
          // but OpenCL spec provides a special query to get access qualifier
          // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
          if (ty->isImageType()) {
            removeImageAccessQualifier(typeName);
            removeImageAccessQualifier(baseTypeName);
          }
  
          argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
          argBaseTypeNames.push_back(
              llvm::MDString::get(VMContext, baseTypeName));
  
          if (isPipe)
            typeQuals = "pipe";
        }
        argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
      }
  
    Fn->setMetadata("kernel_arg_addr_space",
                    llvm::MDNode::get(VMContext, addressQuals));
    Fn->setMetadata("kernel_arg_access_qual",
                    llvm::MDNode::get(VMContext, accessQuals));
    Fn->setMetadata("kernel_arg_type",
                    llvm::MDNode::get(VMContext, argTypeNames));
    Fn->setMetadata("kernel_arg_base_type",
                    llvm::MDNode::get(VMContext, argBaseTypeNames));
    Fn->setMetadata("kernel_arg_type_qual",
                    llvm::MDNode::get(VMContext, argTypeQuals));
    if (getCodeGenOpts().EmitOpenCLArgMetadata)
      Fn->setMetadata("kernel_arg_name",
                      llvm::MDNode::get(VMContext, argNames));
  }
  
  /// 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;
  }
  
  static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
                                                        const CXXMethodDecl *MD) {
    // Check that the type metadata can ever actually be used by a call.
    if (!CGM.getCodeGenOpts().LTOUnit ||
        !CGM.HasHiddenLTOVisibility(MD->getParent()))
      return false;
  
    // Only functions whose address can be taken with a member function pointer
    // need this sort of type metadata.
    return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
           !isa<CXXDestructorDecl>(MD);
  }
  
  std::vector<const CXXRecordDecl *>
  CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
    llvm::SetVector<const CXXRecordDecl *> MostBases;
  
    std::function<void (const CXXRecordDecl *)> CollectMostBases;
    CollectMostBases = [&](const CXXRecordDecl *RD) {
      if (RD->getNumBases() == 0)
        MostBases.insert(RD);
      for (const CXXBaseSpecifier &B : RD->bases())
        CollectMostBases(B.getType()->getAsCXXRecordDecl());
    };
    CollectMostBases(RD);
    return MostBases.takeVector();
  }
  
  void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
                                                             llvm::Function *F) {
    llvm::AttrBuilder B;
  
    if (CodeGenOpts.UnwindTables)
      B.addAttribute(llvm::Attribute::UWTable);
  
    if (CodeGenOpts.StackClashProtector)
      B.addAttribute("probe-stack", "inline-asm");
  
    if (!hasUnwindExceptions(LangOpts))
      B.addAttribute(llvm::Attribute::NoUnwind);
  
    if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
      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) {
      // If we don't have a declaration to control inlining, the function isn't
      // explicitly marked as alwaysinline for semantic reasons, and inlining is
      // disabled, mark the function as noinline.
      if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
          CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
        B.addAttribute(llvm::Attribute::NoInline);
  
      F->addFnAttrs(B);
      return;
    }
  
    // Track whether we need to add the optnone LLVM attribute,
    // starting with the default for this optimization level.
    bool ShouldAddOptNone =
        !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
    // We can't add optnone in the following cases, it won't pass the verifier.
    ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
    ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
  
    // Add optnone, but do so only if the function isn't always_inline.
    if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
        !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
      B.addAttribute(llvm::Attribute::OptimizeNone);
  
      // OptimizeNone implies noinline; we should not be inlining such functions.
      B.addAttribute(llvm::Attribute::NoInline);
  
      // We still need to handle naked functions even though optnone subsumes
      // much of their semantics.
      if (D->hasAttr<NakedAttr>())
        B.addAttribute(llvm::Attribute::Naked);
  
      // OptimizeNone wins over OptimizeForSize and MinSize.
      F->removeFnAttr(llvm::Attribute::OptimizeForSize);
      F->removeFnAttr(llvm::Attribute::MinSize);
    } else 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>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
      // Add noinline if the function isn't always_inline.
      B.addAttribute(llvm::Attribute::NoInline);
    } else if (D->hasAttr<AlwaysInlineAttr>() &&
               !F->hasFnAttribute(llvm::Attribute::NoInline)) {
      // (noinline wins over always_inline, and we can't specify both in IR)
      B.addAttribute(llvm::Attribute::AlwaysInline);
    } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
      // If we're not inlining, then force everything that isn't always_inline to
      // carry an explicit noinline attribute.
      if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
        B.addAttribute(llvm::Attribute::NoInline);
    } else {
      // Otherwise, propagate the inline hint attribute and potentially use its
      // absence to mark things as noinline.
      if (auto *FD = dyn_cast<FunctionDecl>(D)) {
        // Search function and template pattern redeclarations for inline.
        auto CheckForInline = [](const FunctionDecl *FD) {
          auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
            return Redecl->isInlineSpecified();
          };
          if (any_of(FD->redecls(), CheckRedeclForInline))
            return true;
          const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
          if (!Pattern)
            return false;
          return any_of(Pattern->redecls(), CheckRedeclForInline);
        };
        if (CheckForInline(FD)) {
          B.addAttribute(llvm::Attribute::InlineHint);
        } else if (CodeGenOpts.getInlining() ==
                       CodeGenOptions::OnlyHintInlining &&
                   !FD->isInlined() &&
                   !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
          B.addAttribute(llvm::Attribute::NoInline);
        }
      }
    }
  
    // Add other optimization related attributes if we are optimizing this
    // function.
    if (!D->hasAttr<OptimizeNoneAttr>()) {
      if (D->hasAttr<ColdAttr>()) {
        if (!ShouldAddOptNone)
          B.addAttribute(llvm::Attribute::OptimizeForSize);
        B.addAttribute(llvm::Attribute::Cold);
      }
      if (D->hasAttr<HotAttr>())
        B.addAttribute(llvm::Attribute::Hot);
      if (D->hasAttr<MinSizeAttr>())
        B.addAttribute(llvm::Attribute::MinSize);
    }
  
    F->addFnAttrs(B);
  
    unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
    if (alignment)
      F->setAlignment(llvm::Align(alignment));
  
    if (!D->hasAttr<AlignedAttr>())
      if (LangOpts.FunctionAlignment)
        F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
  
    // 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(llvm::Align(2));
    }
  
    // In the cross-dso CFI mode with canonical jump tables, we want !type
    // attributes on definitions only.
    if (CodeGenOpts.SanitizeCfiCrossDso &&
        CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
      if (auto *FD = dyn_cast<FunctionDecl>(D)) {
        // Skip available_externally functions. They won't be codegen'ed in the
        // current module anyway.
        if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
          CreateFunctionTypeMetadataForIcall(FD, F);
      }
    }
  
    // Emit type metadata on member functions for member function pointer checks.
    // These are only ever necessary on definitions; we're guaranteed that the
    // definition will be present in the LTO unit as a result of LTO visibility.
    auto *MD = dyn_cast<CXXMethodDecl>(D);
    if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
      for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
        llvm::Metadata *Id =
            CreateMetadataIdentifierForType(Context.getMemberPointerType(
                MD->getType(), Context.getRecordType(Base).getTypePtr()));
        F->addTypeMetadata(0, Id);
      }
    }
  }
  
  void CodeGenModule::setLLVMFunctionFEnvAttributes(const FunctionDecl *D,
                                                    llvm::Function *F) {
    if (D->hasAttr<StrictFPAttr>()) {
      llvm::AttrBuilder FuncAttrs;
      FuncAttrs.addAttribute("strictfp");
      F->addFnAttrs(FuncAttrs);
    }
  }
  
  void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
    const Decl *D = GD.getDecl();
    if (dyn_cast_or_null<NamedDecl>(D))
      setGVProperties(GV, GD);
    else
      GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
  
    if (D && D->hasAttr<UsedAttr>())
      addUsedOrCompilerUsedGlobal(GV);
  
    if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
      const auto *VD = cast<VarDecl>(D);
      if (VD->getType().isConstQualified() &&
          VD->getStorageDuration() == SD_Static)
        addUsedOrCompilerUsedGlobal(GV);
    }
  }
  
  bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
                                                  llvm::AttrBuilder &Attrs) {
    // Add target-cpu and target-features attributes to functions. If
    // we have a decl for the function and it has a target attribute then
    // parse that and add it to the feature set.
    StringRef TargetCPU = getTarget().getTargetOpts().CPU;
    StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
    std::vector<std::string> Features;
    const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
    FD = FD ? FD->getMostRecentDecl() : FD;
    const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
    const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
    bool AddedAttr = false;
    if (TD || SD) {
      llvm::StringMap<bool> FeatureMap;
      getContext().getFunctionFeatureMap(FeatureMap, GD);
  
      // Produce the canonical string for this set of features.
      for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
        Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
  
      // Now add the target-cpu and target-features to the function.
      // While we populated the feature map above, we still need to
      // get and parse the target attribute so we can get the cpu for
      // the function.
      if (TD) {
        ParsedTargetAttr ParsedAttr = TD->parse();
        if (!ParsedAttr.Architecture.empty() &&
            getTarget().isValidCPUName(ParsedAttr.Architecture)) {
          TargetCPU = ParsedAttr.Architecture;
          TuneCPU = ""; // Clear the tune CPU.
        }
        if (!ParsedAttr.Tune.empty() &&
            getTarget().isValidCPUName(ParsedAttr.Tune))
          TuneCPU = ParsedAttr.Tune;
      }
    } else {
      // Otherwise just add the existing target cpu and target features to the
      // function.
      Features = getTarget().getTargetOpts().Features;
    }
  
    if (!TargetCPU.empty()) {
      Attrs.addAttribute("target-cpu", TargetCPU);
      AddedAttr = true;
    }
    if (!TuneCPU.empty()) {
      Attrs.addAttribute("tune-cpu", TuneCPU);
      AddedAttr = true;
    }
    if (!Features.empty()) {
      llvm::sort(Features);
      Attrs.addAttribute("target-features", llvm::join(Features, ","));
      AddedAttr = true;
    }
  
    return AddedAttr;
  }
  
  void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
                                            llvm::GlobalObject *GO) {
    const Decl *D = GD.getDecl();
    SetCommonAttributes(GD, GO);
  
    if (D) {
      if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
        if (D->hasAttr<RetainAttr>())
          addUsedGlobal(GV);
        if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
          GV->addAttribute("bss-section", SA->getName());
        if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
          GV->addAttribute("data-section", SA->getName());
        if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
          GV->addAttribute("rodata-section", SA->getName());
        if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
          GV->addAttribute("relro-section", SA->getName());
      }
  
      if (auto *F = dyn_cast<llvm::Function>(GO)) {
        if (D->hasAttr<RetainAttr>())
          addUsedGlobal(F);
        if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
          if (!D->getAttr<SectionAttr>())
            F->addFnAttr("implicit-section-name", SA->getName());
  
        llvm::AttrBuilder Attrs;
        if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
          // We know that GetCPUAndFeaturesAttributes will always have the
          // newest set, since it has the newest possible FunctionDecl, so the
          // new ones should replace the old.
          llvm::AttrBuilder RemoveAttrs;
          RemoveAttrs.addAttribute("target-cpu");
          RemoveAttrs.addAttribute("target-features");
          RemoveAttrs.addAttribute("tune-cpu");
          F->removeFnAttrs(RemoveAttrs);
          F->addFnAttrs(Attrs);
        }
      }
  
      if (const auto *CSA = D->getAttr<CodeSegAttr>())
        GO->setSection(CSA->getName());
      else if (const auto *SA = D->getAttr<SectionAttr>())
        GO->setSection(SA->getName());
    }
  
    getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
  }
  
  void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
                                                    llvm::Function *F,
                                                    const CGFunctionInfo &FI) {
    const Decl *D = GD.getDecl();
    SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
    SetLLVMFunctionAttributesForDefinition(D, F);
  
    F->setLinkage(llvm::Function::InternalLinkage);
  
    setNonAliasAttributes(GD, F);
  }
  
  static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
    // Set linkage and visibility in case we never see a definition.
    LinkageInfo LV = ND->getLinkageAndVisibility();
    // Don't set internal linkage on declarations.
    // "extern_weak" is overloaded in LLVM; we probably should have
    // separate linkage types for this.
    if (isExternallyVisible(LV.getLinkage()) &&
        (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
      GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
  }
  
  void CodeGenModule::CreateFunctionTypeMetadataForIcall(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 or member function pointer
    // checks elsewhere.
    if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
      return;
  
    llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
    F->addTypeMetadata(0, MD);
    F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
  
    // Emit a hash-based bit set entry for cross-DSO calls.
    if (CodeGenOpts.SanitizeCfiCrossDso)
      if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
        F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
  }
  
  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(GD, getTypes().arrangeGlobalDeclaration(GD), F,
                                IsThunk);
  
    // 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) &&
        !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
      assert(!F->arg_empty() &&
             F->arg_begin()->getType()
               ->canLosslesslyBitCastTo(F->getReturnType()) &&
             "unexpected this return");
      F->addParamAttr(0, llvm::Attribute::Returned);
    }
  
    // Only a few attributes are set on declarations; these may later be
    // overridden by a definition.
  
    setLinkageForGV(F, FD);
    setGVProperties(F, FD);
  
    // Setup target-specific attributes.
    if (!IsIncompleteFunction && F->isDeclaration())
      getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
  
    if (const auto *CSA = FD->getAttr<CodeSegAttr>())
      F->setSection(CSA->getName());
    else if (const auto *SA = FD->getAttr<SectionAttr>())
       F->setSection(SA->getName());
  
    if (const auto *EA = FD->getAttr<ErrorAttr>()) {
      if (EA->isError())
        F->addFnAttr("dontcall-error", EA->getUserDiagnostic());
      else if (EA->isWarning())
        F->addFnAttr("dontcall-warn", EA->getUserDiagnostic());
    }
  
    // If we plan on emitting this inline builtin, we can't treat it as a builtin.
    if (FD->isInlineBuiltinDeclaration()) {
      const FunctionDecl *FDBody;
      bool HasBody = FD->hasBody(FDBody);
      (void)HasBody;
      assert(HasBody && "Inline builtin declarations should always have an "
                        "available body!");
      if (shouldEmitFunction(FDBody))
        F->addFnAttr(llvm::Attribute::NoBuiltin);
    }
  
    if (FD->isReplaceableGlobalAllocationFunction()) {
      // 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.
      F->addFnAttr(llvm::Attribute::NoBuiltin);
    }
  
    if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
      F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
    else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
      if (MD->isVirtual())
        F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
  
    // Don't emit entries for function declarations in the cross-DSO mode. This
    // is handled with better precision by the receiving DSO. But if jump tables
    // are non-canonical then we need type metadata in order to produce the local
    // jump table.
    if (!CodeGenOpts.SanitizeCfiCrossDso ||
        !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
      CreateFunctionTypeMetadataForIcall(FD, F);
  
    if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
      getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
  
    if (const auto *CB = FD->getAttr<CallbackAttr>()) {
      // Annotate the callback behavior as metadata:
      //  - The callback callee (as argument number).
      //  - The callback payloads (as argument numbers).
      llvm::LLVMContext &Ctx = F->getContext();
      llvm::MDBuilder MDB(Ctx);
  
      // The payload indices are all but the first one in the encoding. The first
      // identifies the callback callee.
      int CalleeIdx = *CB->encoding_begin();
      ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
      F->addMetadata(llvm::LLVMContext::MD_callback,
                     *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
                                                 CalleeIdx, PayloadIndices,
                                                 /* VarArgsArePassed */ false)}));
    }
  }
  
  void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
    assert((isa<llvm::Function>(GV) || !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);
  }
  
  void CodeGenModule::addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV) {
    assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
           "Only globals with definition can force usage.");
    if (getTriple().isOSBinFormatELF())
      LLVMCompilerUsed.emplace_back(GV);
    else
      LLVMUsed.emplace_back(GV);
  }
  
  static void emitUsed(CodeGenModule &CGM, StringRef Name,
                       std::vector<llvm::WeakTrackingVH> &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);
    if (Opt.empty())
      return;
    auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
    LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
  }
  
  void CodeGenModule::AddDependentLib(StringRef Lib) {
    auto &C = getLLVMContext();
    if (getTarget().getTriple().isOSBinFormatELF()) {
        ELFDependentLibraries.push_back(
          llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
      return;
    }
  
    llvm::SmallString<24> Opt;
    getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
    auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
    LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
  }
  
  /// 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::MDNode *> &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();
    bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
  
    // For modules that use export_as for linking, use that module
    // name instead.
    if (Mod->UseExportAsModuleLinkName)
      return;
  
    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.
      if (IsELF) {
        llvm::Metadata *Args[2] = {
            llvm::MDString::get(Context, "lib"),
            llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
        };
        Metadata.push_back(llvm::MDNode::get(Context, Args));
      } else {
        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) {
      // Do not add any link flags when an implementation TU of a module imports
      // a header of that same module.
      if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
          !getLangOpts().isCompilingModule())
        continue;
      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 (const auto &SM : Mod->submodules()) {
        // Skip explicit children; they need to be explicitly imported to be
        // linked against.
        if (SM->IsExplicit)
          continue;
  
        if (Visited.insert(SM).second) {
          Stack.push_back(SM);
          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::MDNode *, 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.
    auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
    for (auto *MD : LinkerOptionsMetadata)
      NMD->addOperand(MD);
  }
  
  void CodeGenModule::EmitDeferred() {
    // Emit deferred declare target declarations.
    if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
      getOpenMPRuntime().emitDeferredTargetDecls();
  
    // 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 vtable doesn't directly cause more vtables to
      // become deferred, although it can cause functions to be
      // emitted that then need those vtables.
      assert(DeferredVTables.empty());
    }
  
    // Emit CUDA/HIP static device variables referenced by host code only.
    // Note we should not clear CUDADeviceVarODRUsedByHost since it is still
    // needed for further handling.
    if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
      for (const auto *V : getContext().CUDADeviceVarODRUsedByHost)
        DeferredDeclsToEmit.push_back(V);
  
    // Stop if we're out of both deferred vtables 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<GlobalDecl> CurDeclsToEmit;
    CurDeclsToEmit.swap(DeferredDeclsToEmit);
  
    for (GlobalDecl &D : CurDeclsToEmit) {
      // 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.
      llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
          GetAddrOfGlobal(D, ForDefinition));
  
      // In case of different address spaces, we may still get a cast, even with
      // IsForDefinition equal to true. Query mangled names table to get
      // GlobalValue.
      if (!GV)
        GV = GetGlobalValue(getMangledName(D));
  
      // Make sure GetGlobalValue returned non-null.
      assert(GV);
  
      // 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->isDeclaration())
        continue;
  
      // If this is OpenMP, check if it is legal to emit this global normally.
      if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
        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::EmitVTablesOpportunistically() {
    // Try to emit external vtables as available_externally if they have emitted
    // all inlined virtual functions.  It runs after EmitDeferred() and therefore
    // is not allowed to create new references to things that need to be emitted
    // lazily. Note that it also uses fact that we eagerly emitting RTTI.
  
    assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
           && "Only emit opportunistic vtables with optimizations");
  
    for (const CXXRecordDecl *RD : OpportunisticVTables) {
      assert(getVTables().isVTableExternal(RD) &&
             "This queue should only contain external vtables");
      if (getCXXABI().canSpeculativelyEmitVTable(RD))
        VTables.GenerateClassData(RD);
    }
    OpportunisticVTables.clear();
  }
  
  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(llvm::GlobalValue::UnnamedAddr::Global);
    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::EmitAnnotationArgs(const AnnotateAttr *Attr) {
    ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
    if (Exprs.empty())
      return llvm::ConstantPointerNull::get(GlobalsInt8PtrTy);
  
    llvm::FoldingSetNodeID ID;
    for (Expr *E : Exprs) {
      ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
    }
    llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
    if (Lookup)
      return Lookup;
  
    llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
    LLVMArgs.reserve(Exprs.size());
    ConstantEmitter ConstEmiter(*this);
    llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
      const auto *CE = cast<clang::ConstantExpr>(E);
      return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
                                      CE->getType());
    });
    auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
    auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
                                        llvm::GlobalValue::PrivateLinkage, Struct,
                                        ".args");
    GV->setSection(AnnotationSection);
    GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
    auto *Bitcasted = llvm::ConstantExpr::getBitCast(GV, GlobalsInt8PtrTy);
  
    Lookup = Bitcasted;
    return Bitcasted;
  }
  
  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),
                   *Args = EmitAnnotationArgs(AA);
  
    llvm::Constant *GVInGlobalsAS = GV;
    if (GV->getAddressSpace() !=
        getDataLayout().getDefaultGlobalsAddressSpace()) {
      GVInGlobalsAS = llvm::ConstantExpr::getAddrSpaceCast(
          GV, GV->getValueType()->getPointerTo(
                  getDataLayout().getDefaultGlobalsAddressSpace()));
    }
  
    // Create the ConstantStruct for the global annotation.
    llvm::Constant *Fields[] = {
        llvm::ConstantExpr::getBitCast(GVInGlobalsAS, GlobalsInt8PtrTy),
        llvm::ConstantExpr::getBitCast(AnnoGV, GlobalsInt8PtrTy),
        llvm::ConstantExpr::getBitCast(UnitGV, GlobalsInt8PtrTy),
        LineNoCst,
        Args,
    };
    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::isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
                                         SourceLocation Loc) const {
    const auto &NoSanitizeL = getContext().getNoSanitizeList();
    // NoSanitize by function name.
    if (NoSanitizeL.containsFunction(Kind, Fn->getName()))
      return true;
    // NoSanitize by location.
    if (Loc.isValid())
      return NoSanitizeL.containsLocation(Kind, 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 NoSanitizeL.containsFile(Kind, MainFile->getName());
    }
    return false;
  }
  
  bool CodeGenModule::isInNoSanitizeList(llvm::GlobalVariable *GV,
                                         SourceLocation Loc, QualType Ty,
                                         StringRef Category) const {
    // For now globals can be ignored only in ASan and KASan.
    const SanitizerMask EnabledAsanMask =
        LangOpts.Sanitize.Mask &
        (SanitizerKind::Address | SanitizerKind::KernelAddress |
         SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress |
         SanitizerKind::MemTag);
    if (!EnabledAsanMask)
      return false;
    const auto &NoSanitizeL = getContext().getNoSanitizeList();
    if (NoSanitizeL.containsGlobal(EnabledAsanMask, GV->getName(), Category))
      return true;
    if (NoSanitizeL.containsLocation(EnabledAsanMask, Loc, Category))
      return true;
    // Check global type.
    if (!Ty.isNull()) {
      // Drill down the array types: if global variable of a fixed type is
      // not sanitized, we also don't instrument arrays of them.
      while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
        Ty = AT->getElementType();
      Ty = Ty.getCanonicalType().getUnqualifiedType();
      // Only record types (classes, structs etc.) are ignored.
      if (Ty->isRecordType()) {
        std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
        if (NoSanitizeL.containsType(EnabledAsanMask, TypeStr, Category))
          return true;
      }
    }
    return false;
  }
  
  bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
                                     StringRef Category) const {
    const auto &XRayFilter = getContext().getXRayFilter();
    using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
    auto Attr = ImbueAttr::NONE;
    if (Loc.isValid())
      Attr = XRayFilter.shouldImbueLocation(Loc, Category);
    if (Attr == ImbueAttr::NONE)
      Attr = XRayFilter.shouldImbueFunction(Fn->getName());
    switch (Attr) {
    case ImbueAttr::NONE:
      return false;
    case ImbueAttr::ALWAYS:
      Fn->addFnAttr("function-instrument", "xray-always");
      break;
    case ImbueAttr::ALWAYS_ARG1:
      Fn->addFnAttr("function-instrument", "xray-always");
      Fn->addFnAttr("xray-log-args", "1");
      break;
    case ImbueAttr::NEVER:
      Fn->addFnAttr("function-instrument", "xray-never");
      break;
    }
    return true;
  }
  
  bool CodeGenModule::isProfileInstrExcluded(llvm::Function *Fn,
                                             SourceLocation Loc) const {
    const auto &ProfileList = getContext().getProfileList();
    // If the profile list is empty, then instrument everything.
    if (ProfileList.isEmpty())
      return false;
    CodeGenOptions::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
    // First, check the function name.
    Optional<bool> V = ProfileList.isFunctionExcluded(Fn->getName(), Kind);
    if (V.hasValue())
      return *V;
    // Next, check the source location.
    if (Loc.isValid()) {
      Optional<bool> V = ProfileList.isLocationExcluded(Loc, Kind);
      if (V.hasValue())
        return *V;
    }
    // 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())) {
      Optional<bool> V = ProfileList.isFileExcluded(MainFile->getName(), Kind);
      if (V.hasValue())
        return *V;
    }
    return ProfileList.getDefault();
  }
  
  bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
    // Never defer when EmitAllDecls is specified.
    if (LangOpts.EmitAllDecls)
      return true;
  
    if (CodeGenOpts.KeepStaticConsts) {
      const auto *VD = dyn_cast<VarDecl>(Global);
      if (VD && VD->getType().isConstQualified() &&
          VD->getStorageDuration() == SD_Static)
        return true;
    }
  
    return getContext().DeclMustBeEmitted(Global);
  }
  
  bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
    // In OpenMP 5.0 variables and function may be marked as
    // device_type(host/nohost) and we should not emit them eagerly unless we sure
    // that they must be emitted on the host/device. To be sure we need to have
    // seen a declare target with an explicit mentioning of the function, we know
    // we have if the level of the declare target attribute is -1. Note that we
    // check somewhere else if we should emit this at all.
    if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd) {
      llvm::Optional<OMPDeclareTargetDeclAttr *> ActiveAttr =
          OMPDeclareTargetDeclAttr::getActiveAttr(Global);
      if (!ActiveAttr || (*ActiveAttr)->getLevel() != (unsigned)-1)
        return false;
    }
  
    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 (const auto *VD = dyn_cast<VarDecl>(Global))
      if (Context.getInlineVariableDefinitionKind(VD) ==
          ASTContext::InlineVariableDefinitionKind::WeakUnknown)
        // A definition of an inline constexpr static data member may change
        // linkage later if it's redeclared outside the class.
        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) &&
        !isTypeConstant(Global->getType(), false) &&
        !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
      return false;
  
    return true;
  }
  
  ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
    StringRef Name = getMangledName(GD);
  
    // The UUID descriptor should be pointer aligned.
    CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
  
    // Look for an existing global.
    if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
      return ConstantAddress(GV, Alignment);
  
    ConstantEmitter Emitter(*this);
    llvm::Constant *Init;
  
    APValue &V = GD->getAsAPValue();
    if (!V.isAbsent()) {
      // If possible, emit the APValue version of the initializer. In particular,
      // this gets the type of the constant right.
      Init = Emitter.emitForInitializer(
          GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
    } else {
      // As a fallback, directly construct the constant.
      // FIXME: This may get padding wrong under esoteric struct layout rules.
      // MSVC appears to create a complete type 'struct __s_GUID' that it
      // presumably uses to represent these constants.
      MSGuidDecl::Parts Parts = GD->getParts();
      llvm::Constant *Fields[4] = {
          llvm::ConstantInt::get(Int32Ty, Parts.Part1),
          llvm::ConstantInt::get(Int16Ty, Parts.Part2),
          llvm::ConstantInt::get(Int16Ty, Parts.Part3),
          llvm::ConstantDataArray::getRaw(
              StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
              Int8Ty)};
      Init = llvm::ConstantStruct::getAnon(Fields);
    }
  
    auto *GV = new llvm::GlobalVariable(
        getModule(), Init->getType(),
        /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
    if (supportsCOMDAT())
      GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
    setDSOLocal(GV);
  
    llvm::Constant *Addr = GV;
    if (!V.isAbsent()) {
      Emitter.finalize(GV);
    } else {
      llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
      Addr = llvm::ConstantExpr::getBitCast(
          GV, Ty->getPointerTo(GV->getAddressSpace()));
    }
    return ConstantAddress(Addr, Alignment);
  }
  
  ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
      const TemplateParamObjectDecl *TPO) {
    StringRef Name = getMangledName(TPO);
    CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
  
    if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
      return ConstantAddress(GV, Alignment);
  
    ConstantEmitter Emitter(*this);
    llvm::Constant *Init = Emitter.emitForInitializer(
          TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
  
    if (!Init) {
      ErrorUnsupported(TPO, "template parameter object");
      return ConstantAddress::invalid();
    }
  
    auto *GV = new llvm::GlobalVariable(
        getModule(), Init->getType(),
        /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
    if (supportsCOMDAT())
      GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
    Emitter.finalize(GV);
  
    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(), DeclTy, LangAS::Default,
                                      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);
  
    // IFunc like an alias whose value is resolved at runtime by calling resolver.
    if (Global->hasAttr<IFuncAttr>())
      return emitIFuncDefinition(GD);
  
    // If this is a cpu_dispatch multiversion function, emit the resolver.
    if (Global->hasAttr<CPUDispatchAttr>())
      return emitCPUDispatchDefinition(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>() &&
            !Global->getType()->isCUDADeviceBuiltinSurfaceType() &&
            !Global->getType()->isCUDADeviceBuiltinTextureType())
          return;
      } else {
        // We need to emit host-side 'shadows' for all global
        // device-side variables because the CUDA runtime needs their
        // size and host-side address in order to provide access to
        // their device-side incarnations.
  
        // So device-only functions are the only things we skip.
        if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
            Global->hasAttr<CUDADeviceAttr>())
          return;
  
        assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
               "Expected Variable or Function");
      }
    }
  
    if (LangOpts.OpenMP) {
      // If this is OpenMP, check if it is legal to emit this global normally.
      if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
        return;
      if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
        if (MustBeEmitted(Global))
          EmitOMPDeclareReduction(DRD);
        return;
      } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
        if (MustBeEmitted(Global))
          EmitOMPDeclareMapper(DMD);
        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)) {
        if (LangOpts.OpenMP) {
          // Emit declaration of the must-be-emitted declare target variable.
          if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
                  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
            bool UnifiedMemoryEnabled =
                getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
            if (*Res == OMPDeclareTargetDeclAttr::MT_To &&
                !UnifiedMemoryEnabled) {
              (void)GetAddrOfGlobalVar(VD);
            } else {
              assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
                      (*Res == OMPDeclareTargetDeclAttr::MT_To &&
                       UnifiedMemoryEnabled)) &&
                     "Link clause or to clause with unified memory expected.");
              (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
            }
  
            return;
          }
        }
        // If this declaration may have caused an inline variable definition to
        // change linkage, make sure that it's emitted.
        if (Context.getInlineVariableDefinitionKind(VD) ==
            ASTContext::InlineVariableDefinitionKind::Strong)
          GetAddrOfGlobalVar(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 (GetGlobalValue(MangledName) != nullptr) {
      // The value has already been used and should therefore be emitted.
      addDeferredDeclToEmit(GD);
    } else if (MustBeEmitted(Global)) {
      // The value must be emitted, but cannot be emitted eagerly.
      assert(!MayBeEmittedEagerly(Global));
      addDeferredDeclToEmit(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;
    }
  }
  
  // Check if T is a class type with a destructor that's not dllimport.
  static bool HasNonDllImportDtor(QualType T) {
    if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
      if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
        if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
          return true;
  
    return false;
  }
  
  namespace {
    struct FunctionIsDirectlyRecursive
        : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
      const StringRef Name;
      const Builtin::Context &BI;
      FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
          : Name(N), BI(C) {}
  
      bool VisitCallExpr(const CallExpr *E) {
        const FunctionDecl *FD = E->getDirectCallee();
        if (!FD)
          return false;
        AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
        if (Attr && Name == Attr->getLabel())
          return true;
        unsigned BuiltinID = FD->getBuiltinID();
        if (!BuiltinID || !BI.isLibFunction(BuiltinID))
          return false;
        StringRef BuiltinName = BI.getName(BuiltinID);
        if (BuiltinName.startswith("__builtin_") &&
            Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
          return true;
        }
        return false;
      }
  
      bool VisitStmt(const Stmt *S) {
        for (const Stmt *Child : S->children())
          if (Child && this->Visit(Child))
            return true;
        return false;
      }
    };
  
    // Make sure we're not referencing non-imported vars or functions.
    struct DLLImportFunctionVisitor
        : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
      bool SafeToInline = true;
  
      bool shouldVisitImplicitCode() const { return true; }
  
      bool VisitVarDecl(VarDecl *VD) {
        if (VD->getTLSKind()) {
          // A thread-local variable cannot be imported.
          SafeToInline = false;
          return SafeToInline;
        }
  
        // A variable definition might imply a destructor call.
        if (VD->isThisDeclarationADefinition())
          SafeToInline = !HasNonDllImportDtor(VD->getType());
  
        return SafeToInline;
      }
  
      bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
        if (const auto *D = E->getTemporary()->getDestructor())
          SafeToInline = D->hasAttr<DLLImportAttr>();
        return SafeToInline;
      }
  
      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 VisitCXXConstructExpr(CXXConstructExpr *E) {
        SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
        return SafeToInline;
      }
  
      bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
        CXXMethodDecl *M = E->getMethodDecl();
        if (!M) {
          // Call through a pointer to member function. This is safe to inline.
          SafeToInline = true;
        } else {
          SafeToInline = M->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);
    const Stmt *Body = FD->getBody();
    return Body ? Walker.Visit(Body) : false;
  }
  
  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>() && !F->hasAttr<AlwaysInlineAttr>()) {
      // Check whether it would be safe to inline this dllimport function.
      DLLImportFunctionVisitor Visitor;
      Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
      if (!Visitor.SafeToInline)
        return false;
  
      if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
        // Implicit destructor invocations aren't captured in the AST, so the
        // check above can't see them. Check for them manually here.
        for (const Decl *Member : Dtor->getParent()->decls())
          if (isa<FieldDecl>(Member))
            if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
              return false;
        for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
          if (HasNonDllImportDtor(B.getType()))
            return false;
      }
    }
  
    // Inline builtins declaration must be emitted. They often are fortified
    // functions.
    if (F->isInlineBuiltinDeclaration())
      return true;
  
    // 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 through asm label/`__builtin_` trickery is
    // clearly not equivalent to the real implementation.
    // This happens in glibc's btowc and in some configure checks.
    return !isTriviallyRecursive(F);
  }
  
  bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
    return CodeGenOpts.OptimizationLevel > 0;
  }
  
  void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
                                                         llvm::GlobalValue *GV) {
    const auto *FD = cast<FunctionDecl>(GD.getDecl());
  
    if (FD->isCPUSpecificMultiVersion()) {
      auto *Spec = FD->getAttr<CPUSpecificAttr>();
      for (unsigned I = 0; I < Spec->cpus_size(); ++I)
        EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
      // Requires multiple emits.
    } else
      EmitGlobalFunctionDefinition(GD, GV);
  }
  
  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 (const auto *FD = dyn_cast<FunctionDecl>(D)) {
      // At -O0, don't generate IR for functions with available_externally
      // linkage.
      if (!shouldEmitFunction(GD))
        return;
  
      llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
        std::string Name;
        llvm::raw_string_ostream OS(Name);
        FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
                                 /*Qualified=*/true);
        return Name;
      });
  
      if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
        // Make sure to emit the definition(s) before we emit the thunks.
        // This is necessary for the generation of certain thunks.
        if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
          ABI->emitCXXStructor(GD);
        else if (FD->isMultiVersion())
          EmitMultiVersionFunctionDefinition(GD, GV);
        else
          EmitGlobalFunctionDefinition(GD, GV);
  
        if (Method->isVirtual())
          getVTables().EmitThunks(GD);
  
        return;
      }
  
      if (FD->isMultiVersion())
        return EmitMultiVersionFunctionDefinition(GD, GV);
      return EmitGlobalFunctionDefinition(GD, GV);
    }
  
    if (const auto *VD = dyn_cast<VarDecl>(D))
      return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
  
    llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
  }
  
  static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
                                                        llvm::Function *NewFn);
  
  static unsigned
  TargetMVPriority(const TargetInfo &TI,
                   const CodeGenFunction::MultiVersionResolverOption &RO) {
    unsigned Priority = 0;
    for (StringRef Feat : RO.Conditions.Features)
      Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
  
    if (!RO.Conditions.Architecture.empty())
      Priority = std::max(
          Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
    return Priority;
  }
  
  // Multiversion functions should be at most 'WeakODRLinkage' so that a different
  // TU can forward declare the function without causing problems.  Particularly
  // in the cases of CPUDispatch, this causes issues. This also makes sure we
  // work with internal linkage functions, so that the same function name can be
  // used with internal linkage in multiple TUs.
  llvm::GlobalValue::LinkageTypes getMultiversionLinkage(CodeGenModule &CGM,
                                                         GlobalDecl GD) {
    const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
    if (FD->getFormalLinkage() == InternalLinkage)
      return llvm::GlobalValue::InternalLinkage;
    return llvm::GlobalValue::WeakODRLinkage;
  }
  
  void CodeGenModule::emitMultiVersionFunctions() {
    std::vector<GlobalDecl> MVFuncsToEmit;
    MultiVersionFuncs.swap(MVFuncsToEmit);
    for (GlobalDecl GD : MVFuncsToEmit) {
      SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
      const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
      getContext().forEachMultiversionedFunctionVersion(
          FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
            GlobalDecl CurGD{
                (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
            StringRef MangledName = getMangledName(CurGD);
            llvm::Constant *Func = GetGlobalValue(MangledName);
            if (!Func) {
              if (CurFD->isDefined()) {
                EmitGlobalFunctionDefinition(CurGD, nullptr);
                Func = GetGlobalValue(MangledName);
              } else {
                const CGFunctionInfo &FI =
                    getTypes().arrangeGlobalDeclaration(GD);
                llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
                Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
                                         /*DontDefer=*/false, ForDefinition);
              }
              assert(Func && "This should have just been created");
            }
  
            const auto *TA = CurFD->getAttr<TargetAttr>();
            llvm::SmallVector<StringRef, 8> Feats;
            TA->getAddedFeatures(Feats);
  
            Options.emplace_back(cast<llvm::Function>(Func),
                                 TA->getArchitecture(), Feats);
          });
  
      llvm::Function *ResolverFunc;
      const TargetInfo &TI = getTarget();
  
      if (TI.supportsIFunc() || FD->isTargetMultiVersion()) {
        ResolverFunc = cast<llvm::Function>(
            GetGlobalValue((getMangledName(GD) + ".resolver").str()));
        ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
      } else {
        ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
      }
  
      if (supportsCOMDAT())
        ResolverFunc->setComdat(
            getModule().getOrInsertComdat(ResolverFunc->getName()));
  
      llvm::stable_sort(
          Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
                         const CodeGenFunction::MultiVersionResolverOption &RHS) {
            return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
          });
      CodeGenFunction CGF(*this);
      CGF.EmitMultiVersionResolver(ResolverFunc, Options);
    }
  
    // Ensure that any additions to the deferred decls list caused by emitting a
    // variant are emitted.  This can happen when the variant itself is inline and
    // calls a function without linkage.
    if (!MVFuncsToEmit.empty())
      EmitDeferred();
  
    // Ensure that any additions to the multiversion funcs list from either the
    // deferred decls or the multiversion functions themselves are emitted.
    if (!MultiVersionFuncs.empty())
      emitMultiVersionFunctions();
  }
  
  void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
    const auto *FD = cast<FunctionDecl>(GD.getDecl());
    assert(FD && "Not a FunctionDecl?");
    const auto *DD = FD->getAttr<CPUDispatchAttr>();
    assert(DD && "Not a cpu_dispatch Function?");
    llvm::Type *DeclTy = getTypes().ConvertType(FD->getType());
  
    if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
      const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
      DeclTy = getTypes().GetFunctionType(FInfo);
    }
  
    StringRef ResolverName = getMangledName(GD);
  
    llvm::Type *ResolverType;
    GlobalDecl ResolverGD;
    if (getTarget().supportsIFunc())
      ResolverType = llvm::FunctionType::get(
          llvm::PointerType::get(DeclTy,
                                 Context.getTargetAddressSpace(FD->getType())),
          false);
    else {
      ResolverType = DeclTy;
      ResolverGD = GD;
    }
  
    auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
        ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
    ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
    if (supportsCOMDAT())
      ResolverFunc->setComdat(
          getModule().getOrInsertComdat(ResolverFunc->getName()));
  
    SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
    const TargetInfo &Target = getTarget();
    unsigned Index = 0;
    for (const IdentifierInfo *II : DD->cpus()) {
      // Get the name of the target function so we can look it up/create it.
      std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
                                getCPUSpecificMangling(*this, II->getName());
  
      llvm::Constant *Func = GetGlobalValue(MangledName);
  
      if (!Func) {
        GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
        if (ExistingDecl.getDecl() &&
            ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
          EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
          Func = GetGlobalValue(MangledName);
        } else {
          if (!ExistingDecl.getDecl())
            ExistingDecl = GD.getWithMultiVersionIndex(Index);
  
        Func = GetOrCreateLLVMFunction(
            MangledName, DeclTy, ExistingDecl,
            /*ForVTable=*/false, /*DontDefer=*/true,
            /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
        }
      }
  
      llvm::SmallVector<StringRef, 32> Features;
      Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
      llvm::transform(Features, Features.begin(),
                      [](StringRef Str) { return Str.substr(1); });
      Features.erase(std::remove_if(
          Features.begin(), Features.end(), [&Target](StringRef Feat) {
            return !Target.validateCpuSupports(Feat);
          }), Features.end());
      Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
      ++Index;
    }
  
    llvm::stable_sort(
        Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
                    const CodeGenFunction::MultiVersionResolverOption &RHS) {
          return llvm::X86::getCpuSupportsMask(LHS.Conditions.Features) >
                 llvm::X86::getCpuSupportsMask(RHS.Conditions.Features);
        });
  
    // If the list contains multiple 'default' versions, such as when it contains
    // 'pentium' and 'generic', don't emit the call to the generic one (since we
    // always run on at least a 'pentium'). We do this by deleting the 'least
    // advanced' (read, lowest mangling letter).
    while (Options.size() > 1 &&
           llvm::X86::getCpuSupportsMask(
               (Options.end() - 2)->Conditions.Features) == 0) {
      StringRef LHSName = (Options.end() - 2)->Function->getName();
      StringRef RHSName = (Options.end() - 1)->Function->getName();
      if (LHSName.compare(RHSName) < 0)
        Options.erase(Options.end() - 2);
      else
        Options.erase(Options.end() - 1);
    }
  
    CodeGenFunction CGF(*this);
    CGF.EmitMultiVersionResolver(ResolverFunc, Options);
  
    if (getTarget().supportsIFunc()) {
      std::string AliasName = getMangledNameImpl(
          *this, GD, FD, /*OmitMultiVersionMangling=*/true);
      llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
      if (!AliasFunc) {
        auto *IFunc = cast<llvm::GlobalIFunc>(GetOrCreateLLVMFunction(
            AliasName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/true,
            /*IsThunk=*/false, llvm::AttributeList(), NotForDefinition));
        auto *GA = llvm::GlobalAlias::create(DeclTy, 0,
                                             getMultiversionLinkage(*this, GD),
                                             AliasName, IFunc, &getModule());
        SetCommonAttributes(GD, GA);
      }
    }
  }
  
  /// If a dispatcher for the specified mangled name is not in the module, create
  /// and return an llvm Function with the specified type.
  llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
      GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
    std::string MangledName =
        getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
  
    // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
    // a separate resolver).
    std::string ResolverName = MangledName;
    if (getTarget().supportsIFunc())
      ResolverName += ".ifunc";
    else if (FD->isTargetMultiVersion())
      ResolverName += ".resolver";
  
    // If this already exists, just return that one.
    if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
      return ResolverGV;
  
    // Since this is the first time we've created this IFunc, make sure
    // that we put this multiversioned function into the list to be
    // replaced later if necessary (target multiversioning only).
    if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
      MultiVersionFuncs.push_back(GD);
  
    if (getTarget().supportsIFunc()) {
      llvm::Type *ResolverType = llvm::FunctionType::get(
          llvm::PointerType::get(
              DeclTy, getContext().getTargetAddressSpace(FD->getType())),
          false);
      llvm::Constant *Resolver = GetOrCreateLLVMFunction(
          MangledName + ".resolver", ResolverType, GlobalDecl{},
          /*ForVTable=*/false);
      llvm::GlobalIFunc *GIF =
          llvm::GlobalIFunc::create(DeclTy, 0, getMultiversionLinkage(*this, GD),
                                    "", Resolver, &getModule());
      GIF->setName(ResolverName);
      SetCommonAttributes(FD, GIF);
  
      return GIF;
    }
  
    llvm::Constant *Resolver = GetOrCreateLLVMFunction(
        ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
    assert(isa<llvm::GlobalValue>(Resolver) &&
           "Resolver should be created for the first time");
    SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
    return Resolver;
  }
  
  /// 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::AttributeList ExtraAttrs,
      ForDefinition_t IsForDefinition) {
    const Decl *D = GD.getDecl();
  
    // Any attempts to use a MultiVersion function should result in retrieving
    // the iFunc instead. Name Mangling will handle the rest of the changes.
    if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
      // For the device mark the function as one that should be emitted.
      if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
          !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
          !DontDefer && !IsForDefinition) {
        if (const FunctionDecl *FDDef = FD->getDefinition()) {
          GlobalDecl GDDef;
          if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
            GDDef = GlobalDecl(CD, GD.getCtorType());
          else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
            GDDef = GlobalDecl(DD, GD.getDtorType());
          else
            GDDef = GlobalDecl(FDDef);
          EmitGlobal(GDDef);
        }
      }
  
      if (FD->isMultiVersion()) {
        if (FD->hasAttr<TargetAttr>())
          UpdateMultiVersionNames(GD, FD);
        if (!IsForDefinition)
          return GetOrCreateMultiVersionResolver(GD, Ty, FD);
      }
    }
  
    // 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);
        setDSOLocal(Entry);
      }
  
      // 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 DiagnosedConflictingDefinitions 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)
              << MangledName;
          getDiags().Report(OtherGD.getDecl()->getLocation(),
                            diag::note_previous_definition);
        }
      }
  
      if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
          (Entry->getValueType() == 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->getValueType()->getPointerTo());
      addGlobalValReplacement(Entry, BC);
    }
  
    assert(F->getName() == MangledName && "name was uniqued!");
    if (D)
      SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
    if (ExtraAttrs.hasFnAttrs()) {
      llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
      F->addFnAttrs(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(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(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(GD.getWithDecl(FD));
              break;
            }
          }
        }
      }
    }
  
    // Make sure the result is of the requested type.
    if (!IsIncompleteFunction) {
      assert(F->getFunctionType() == 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,
                                                ForDefinition_t IsForDefinition) {
    assert(!cast<FunctionDecl>(GD.getDecl())->isConsteval() &&
           "consteval function should never be emitted");
    // If there was no specific requested type, just convert it now.
    if (!Ty) {
      const auto *FD = cast<FunctionDecl>(GD.getDecl());
      Ty = getTypes().ConvertType(FD->getType());
    }
  
    // Devirtualized destructor calls may come through here instead of via
    // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
    // of the complete destructor when necessary.
    if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
      if (getTarget().getCXXABI().isMicrosoft() &&
          GD.getDtorType() == Dtor_Complete &&
          DD->getParent()->getNumVBases() == 0)
        GD = GlobalDecl(DD, Dtor_Base);
    }
  
    StringRef MangledName = getMangledName(GD);
    auto *F = GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
                                      /*IsThunk=*/false, llvm::AttributeList(),
                                      IsForDefinition);
    // Returns kernel handle for HIP kernel stub function.
    if (LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
        cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
      auto *Handle = getCUDARuntime().getKernelHandle(
          cast<llvm::Function>(F->stripPointerCasts()), GD);
      if (IsForDefinition)
        return F;
      return llvm::ConstantExpr::getBitCast(Handle, Ty->getPointerTo());
    }
    return F;
  }
  
  static const FunctionDecl *
  GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
    TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
    DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
  
    IdentifierInfo &CII = C.Idents.get(Name);
    for (const auto *Result : DC->lookup(&CII))
      if (const auto *FD = dyn_cast<FunctionDecl>(Result))
        return FD;
  
    if (!C.getLangOpts().CPlusPlus)
      return nullptr;
  
    // Demangle the premangled name from getTerminateFn()
    IdentifierInfo &CXXII =
        (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
            ? C.Idents.get("terminate")
            : C.Idents.get(Name);
  
    for (const auto &N : {"__cxxabiv1", "std"}) {
      IdentifierInfo &NS = C.Idents.get(N);
      for (const auto *Result : DC->lookup(&NS)) {
        const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
        if (auto *LSD = dyn_cast<LinkageSpecDecl>(Result))
          for (const auto *Result : LSD->lookup(&NS))
            if ((ND = dyn_cast<NamespaceDecl>(Result)))
              break;
  
        if (ND)
          for (const auto *Result : ND->lookup(&CXXII))
            if (const auto *FD = dyn_cast<FunctionDecl>(Result))
              return FD;
      }
    }
  
    return nullptr;
  }
  
  /// CreateRuntimeFunction - Create a new runtime function with the specified
  /// type and name.
  llvm::FunctionCallee
  CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
                                       llvm::AttributeList ExtraAttrs, bool Local,
                                       bool AssumeConvergent) {
    if (AssumeConvergent) {
      ExtraAttrs =
          ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
    }
  
    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());
  
        // In Windows Itanium environments, try to mark runtime functions
        // dllimport. For Mingw and MSVC, don't. We don't really know if the user
        // will link their standard library statically or dynamically. Marking
        // functions imported when they are not imported can cause linker errors
        // and warnings.
        if (!Local && getTriple().isWindowsItaniumEnvironment() &&
            !getCodeGenOpts().LTOVisibilityPublicStd) {
          const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
          if (!FD || FD->hasAttr<DLLImportAttr>()) {
            F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
            F->setLinkage(llvm::GlobalValue::ExternalLinkage);
          }
        }
        setDSOLocal(F);
      }
    }
  
    return {FTy, 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 and address
  /// space. 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.
  ///
  /// If IsForDefinition is true, it is guaranteed that an actual global with
  /// type Ty will be returned, not conversion of a variable with the same
  /// mangled name but some other type.
  llvm::Constant *
  CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
                                       LangAS AddrSpace, const VarDecl *D,
                                       ForDefinition_t IsForDefinition) {
    // Lookup the entry, lazily creating it if necessary.
    llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
    unsigned TargetAS = getContext().getTargetAddressSpace(AddrSpace);
    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 (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
        getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
  
      if (Entry->getValueType() == Ty && Entry->getAddressSpace() == TargetAS)
        return Entry;
  
      // If there are two attempts to define the same mangled name, issue an
      // error.
      if (IsForDefinition && !Entry->isDeclaration()) {
        GlobalDecl OtherGD;
        const VarDecl *OtherD;
  
        // Check that D is not yet in DiagnosedConflictingDefinitions is required
        // to make sure that we issue an error only once.
        if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
            (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
            (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
            OtherD->hasInit() &&
            DiagnosedConflictingDefinitions.insert(D).second) {
          getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
              << MangledName;
          getDiags().Report(OtherGD.getDecl()->getLocation(),
                            diag::note_previous_definition);
        }
      }
  
      // Make sure the result is of the correct type.
      if (Entry->getType()->getAddressSpace() != TargetAS) {
        return llvm::ConstantExpr::getAddrSpaceCast(Entry,
                                                    Ty->getPointerTo(TargetAS));
      }
  
      // (If global is requested for a definition, we always need to create a new
      // global, not just return a bitcast.)
      if (!IsForDefinition)
        return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo(TargetAS));
    }
  
    auto DAddrSpace = GetGlobalVarAddressSpace(D);
  
    auto *GV = new llvm::GlobalVariable(
        getModule(), Ty, false, llvm::GlobalValue::ExternalLinkage, nullptr,
        MangledName, nullptr, llvm::GlobalVariable::NotThreadLocal,
        getContext().getTargetAddressSpace(DAddrSpace));
  
    // If we already created a global with the same mangled name (but different
    // type) before, take its name and remove it from its parent.
    if (Entry) {
      GV->takeName(Entry);
  
      if (!Entry->use_empty()) {
        llvm::Constant *NewPtrForOldDecl =
            llvm::ConstantExpr::getBitCast(GV, Entry->getType());
        Entry->replaceAllUsesWith(NewPtrForOldDecl);
      }
  
      Entry->eraseFromParent();
    }
  
    // 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(DDI->second);
      DeferredDecls.erase(DDI);
    }
  
    // Handle things which are present even on external declarations.
    if (D) {
      if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
        getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
  
      // 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).getAsAlign());
  
      setLinkageForGV(GV, D);
  
      if (D->getTLSKind()) {
        if (D->getTLSKind() == VarDecl::TLS_Dynamic)
          CXXThreadLocals.push_back(D);
        setTLSMode(GV, *D);
      }
  
      setGVProperties(GV, D);
  
      // If required by the ABI, treat declarations of static data members with
      // inline initializers as definitions.
      if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
        EmitGlobalVarDefinition(D);
      }
  
      // Emit section information for extern variables.
      if (D->hasExternalStorage()) {
        if (const SectionAttr *SA = D->getAttr<SectionAttr>())
          GV->setSection(SA->getName());
      }
  
      // Handle XCore specific ABI requirements.
      if (getTriple().getArch() == llvm::Triple::xcore &&
          D->getLanguageLinkage() == CLanguageLinkage &&
          D->getType().isConstant(Context) &&
          isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
        GV->setSection(".cp.rodata");
  
      // Check if we a have a const declaration with an initializer, we may be
      // able to emit it as available_externally to expose it's value to the
      // optimizer.
      if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
          D->getType().isConstQualified() && !GV->hasInitializer() &&
          !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
        const auto *Record =
            Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
        bool HasMutableFields = Record && Record->hasMutableFields();
        if (!HasMutableFields) {
          const VarDecl *InitDecl;
          const Expr *InitExpr = D->getAnyInitializer(InitDecl);
          if (InitExpr) {
            ConstantEmitter emitter(*this);
            llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
            if (Init) {
              auto *InitType = Init->getType();
              if (GV->getValueType() != InitType) {
                // The type of the initializer does not match the definition.
                // This happens when an initializer has a different type from
                // the type of the global (because of padding at the end of a
                // structure for instance).
                GV->setName(StringRef());
                // Make a new global with the correct type, this is now guaranteed
                // to work.
                auto *NewGV = cast<llvm::GlobalVariable>(
                    GetAddrOfGlobalVar(D, InitType, IsForDefinition)
                        ->stripPointerCasts());
  
                // Erase the old global, since it is no longer used.
                GV->eraseFromParent();
                GV = NewGV;
              } else {
                GV->setInitializer(Init);
                GV->setConstant(true);
                GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
              }
              emitter.finalize(GV);
            }
          }
        }
      }
    }
  
    if (GV->isDeclaration()) {
      getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
      // External HIP managed variables needed to be recorded for transformation
      // in both device and host compilations.
      if (getLangOpts().CUDA && D && D->hasAttr<HIPManagedAttr>() &&
          D->hasExternalStorage())
        getCUDARuntime().handleVarRegistration(D, *GV);
    }
  
    LangAS ExpectedAS =
        D ? D->getType().getAddressSpace()
          : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
    assert(getContext().getTargetAddressSpace(ExpectedAS) == TargetAS);
    if (DAddrSpace != ExpectedAS) {
      return getTargetCodeGenInfo().performAddrSpaceCast(
          *this, GV, DAddrSpace, ExpectedAS, Ty->getPointerTo(TargetAS));
    }
  
    return GV;
  }
  
  llvm::Constant *
  CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
    const Decl *D = GD.getDecl();
  
    if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
      return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
                                  /*DontDefer=*/false, IsForDefinition);
  
    if (isa<CXXMethodDecl>(D)) {
      auto FInfo =
          &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
      auto Ty = getTypes().GetFunctionType(*FInfo);
      return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
                               IsForDefinition);
    }
  
    if (isa<FunctionDecl>(D)) {
      const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
      llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
      return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
                               IsForDefinition);
    }
  
    return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
  }
  
  llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
      StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
      unsigned Alignment) {
    llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
    llvm::GlobalVariable *OldGV = nullptr;
  
    if (GV) {
      // Check if the variable has the right type.
      if (GV->getValueType() == 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()));
  
    GV->setAlignment(llvm::MaybeAlign(Alignment));
  
    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. If IsForDefinition is true, it is guaranteed
  /// that an actual global with type Ty will be returned, not conversion of a
  /// variable with the same mangled name but some other type.
  llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
                                                    llvm::Type *Ty,
                                             ForDefinition_t IsForDefinition) {
    assert(D->hasGlobalStorage() && "Not a global variable");
    QualType ASTTy = D->getType();
    if (!Ty)
      Ty = getTypes().ConvertTypeForMem(ASTTy);
  
    StringRef MangledName = getMangledName(D);
    return GetOrCreateLLVMGlobal(MangledName, Ty, ASTTy.getAddressSpace(), D,
                                 IsForDefinition);
  }
  
  /// CreateRuntimeVariable - Create a new runtime global variable with the
  /// specified type and name.
  llvm::Constant *
  CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
                                       StringRef Name) {
    LangAS AddrSpace = getContext().getLangOpts().OpenCL ? LangAS::opencl_global
                                                         : LangAS::Default;
    auto *Ret = GetOrCreateLLVMGlobal(Name, Ty, AddrSpace, nullptr);
    setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
    return Ret;
  }
  
  void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
    assert(!D->getInit() && "Cannot emit definite definitions here!");
  
    StringRef MangledName = getMangledName(D);
    llvm::GlobalValue *GV = GetGlobalValue(MangledName);
  
    // We already have a definition, not declaration, with the same mangled name.
    // Emitting of declaration is not required (and actually overwrites emitted
    // definition).
    if (GV && !GV->isDeclaration())
      return;
  
    // If we have not seen a reference to this variable yet, place it into the
    // deferred declarations table to be emitted if needed later.
    if (!MustBeEmitted(D) && !GV) {
        DeferredDecls[MangledName] = D;
        return;
    }
  
    // The tentative definition is the only definition.
    EmitGlobalVarDefinition(D);
  }
  
  void CodeGenModule::EmitExternalDeclaration(const VarDecl *D) {
    EmitExternalVarDeclaration(D);
  }
  
  CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
    return Context.toCharUnitsFromBits(
        getDataLayout().getTypeStoreSizeInBits(Ty));
  }
  
  LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
    if (LangOpts.OpenCL) {
      LangAS AS = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
      assert(AS == LangAS::opencl_global ||
             AS == LangAS::opencl_global_device ||
             AS == LangAS::opencl_global_host ||
             AS == LangAS::opencl_constant ||
             AS == LangAS::opencl_local ||
             AS >= LangAS::FirstTargetAddressSpace);
      return AS;
    }
  
    if (LangOpts.SYCLIsDevice &&
        (!D || D->getType().getAddressSpace() == LangAS::Default))
      return LangAS::sycl_global;
  
    if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
      if (D && D->hasAttr<CUDAConstantAttr>())
        return LangAS::cuda_constant;
      else if (D && D->hasAttr<CUDASharedAttr>())
        return LangAS::cuda_shared;
      else if (D && D->hasAttr<CUDADeviceAttr>())
        return LangAS::cuda_device;
      else if (D && D->getType().isConstQualified())
        return LangAS::cuda_constant;
      else
        return LangAS::cuda_device;
    }
  
    if (LangOpts.OpenMP) {
      LangAS AS;
      if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
        return AS;
    }
    return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
  }
  
  LangAS CodeGenModule::GetGlobalConstantAddressSpace() const {
    // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
    if (LangOpts.OpenCL)
      return LangAS::opencl_constant;
    if (LangOpts.SYCLIsDevice)
      return LangAS::sycl_global;
    if (auto AS = getTarget().getConstantAddressSpace())
      return AS.getValue();
    return LangAS::Default;
  }
  
  // In address space agnostic languages, string literals are in default address
  // space in AST. However, certain targets (e.g. amdgcn) request them to be
  // emitted in constant address space in LLVM IR. To be consistent with other
  // parts of AST, string literal global variables in constant address space
  // need to be casted to default address space before being put into address
  // map and referenced by other part of CodeGen.
  // In OpenCL, string literals are in constant address space in AST, therefore
  // they should not be casted to default address space.
  static llvm::Constant *
  castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
                                         llvm::GlobalVariable *GV) {
    llvm::Constant *Cast = GV;
    if (!CGM.getLangOpts().OpenCL) {
      auto AS = CGM.GetGlobalConstantAddressSpace();
      if (AS != LangAS::Default)
        Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
            CGM, GV, AS, LangAS::Default,
            GV->getValueType()->getPointerTo(
                CGM.getContext().getTargetAddressSpace(LangAS::Default)));
    }
    return Cast;
  }
  
  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;
  
    // Do not set COMDAT attribute for CUDA/HIP stub functions to prevent
    // them being "merged" by the COMDAT Folding linker optimization.
    if (D.hasAttr<CUDAGlobalAttr>())
      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()));
  }
  
  /// Pass IsTentative as true if you want to create a tentative definition.
  void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
                                              bool IsTentative) {
    // OpenCL global variables of sampler type are translated to function calls,
    // therefore no need to be translated.
    QualType ASTTy = D->getType();
    if (getLangOpts().OpenCL && ASTTy->isSamplerT())
      return;
  
    // If this is OpenMP device, check if it is legal to emit this global
    // normally.
    if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
        OpenMPRuntime->emitTargetGlobalVariable(D))
      return;
  
    llvm::TrackingVH<llvm::Constant> Init;
    bool NeedsGlobalCtor = false;
    bool NeedsGlobalDtor =
        D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
  
    const VarDecl *InitDecl;
    const Expr *InitExpr = D->getAnyInitializer(InitDecl);
  
    Optional<ConstantEmitter> emitter;
  
    // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
    // as part of their declaration."  Sema has already checked for
    // error cases, so we just need to set Init to UndefValue.
    bool IsCUDASharedVar =
        getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
    // Shadows of initialized device-side global variables are also left
    // undefined.
    // Managed Variables should be initialized on both host side and device side.
    bool IsCUDAShadowVar =
        !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
        (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
         D->hasAttr<CUDASharedAttr>());
    bool IsCUDADeviceShadowVar =
        getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
        (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
         D->getType()->isCUDADeviceBuiltinTextureType());
    if (getLangOpts().CUDA &&
        (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
      Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
    else if (D->hasAttr<LoaderUninitializedAttr>())
      Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(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);
      emitter.emplace(*this);
      llvm::Constant *Initializer = emitter->tryEmitForInitializer(*InitDecl);
      if (!Initializer) {
        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 {
        Init = Initializer;
        // 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, ForDefinition_t(!IsTentative));
  
    // Strip off pointer casts if we got them.
    Entry = Entry->stripPointerCasts();
  
    // 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->getValueType() != InitType ||
        GV->getType()->getAddressSpace() !=
            getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
  
      // 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, ForDefinition_t(!IsTentative))
              ->stripPointerCasts());
  
      // Replace all uses of the old global with the new global
      llvm::Constant *NewPtrForOldDecl =
          llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(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);
  
    // Set the llvm linkage type as appropriate.
    llvm::GlobalValue::LinkageTypes Linkage =
        getLLVMLinkageVarDefinition(D, GV->isConstant());
  
    // 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) {
      if (LangOpts.CUDAIsDevice) {
        if (Linkage != llvm::GlobalValue::InternalLinkage &&
            (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
             D->getType()->isCUDADeviceBuiltinSurfaceType() ||
             D->getType()->isCUDADeviceBuiltinTextureType()))
          GV->setExternallyInitialized(true);
      } else {
        getCUDARuntime().internalizeDeviceSideVar(D, Linkage);
      }
      getCUDARuntime().handleVarRegistration(D, *GV);
    }
  
    GV->setInitializer(Init);
    if (emitter)
      emitter->finalize(GV);
  
    // 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).getAsAlign());
  
    // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
    // function is only defined alongside the variable, not also alongside
    // callers. Normally, all accesses to a thread_local go through the
    // thread-wrapper in order to ensure initialization has occurred, underlying
    // variable will never be used other than the thread-wrapper, so it can be
    // converted to internal linkage.
    //
    // However, if the variable has the 'constinit' attribute, it _can_ be
    // referenced directly, without calling the thread-wrapper, so the linkage
    // must not be changed.
    //
    // Additionally, if the variable isn't plain external linkage, e.g. if it's
    // weak or linkonce, the de-duplication semantics are important to preserve,
    // so we don't change the linkage.
    if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
        Linkage == llvm::GlobalValue::ExternalLinkage &&
        Context.getTargetInfo().getTriple().isOSDarwin() &&
        !D->hasAttr<ConstInitAttr>())
      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);
      // Tentative definition of global variables may be initialized with
      // non-zero null pointers. In this case they should have weak linkage
      // since common linkage must have zero initializer and must not have
      // explicit section therefore cannot have non-zero initial value.
      if (!GV->getInitializer()->isNullValue())
        GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
    }
  
    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().hasReducedDebugInfo())
        DI->EmitGlobalVariable(GV, D);
  }
  
  void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
    if (CGDebugInfo *DI = getModuleDebugInfo())
      if (getCodeGenOpts().hasReducedDebugInfo()) {
        QualType ASTTy = D->getType();
        llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
        llvm::Constant *GV =
            GetOrCreateLLVMGlobal(D->getName(), Ty, ASTTy.getAddressSpace(), D);
        DI->EmitExternalVariable(
            cast<llvm::GlobalVariable>(GV->stripPointerCasts()), 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;
  
    // A variable cannot be both common and exist in a section.
    // We don't try to determine which is the right section in the front-end.
    // If no specialized section name is applicable, it will resort to default.
    if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
        D->hasAttr<PragmaClangDataSectionAttr>() ||
        D->hasAttr<PragmaClangRelroSectionAttr>() ||
        D->hasAttr<PragmaClangRodataSectionAttr>())
      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 linkage 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;
        }
      }
    }
  
    // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
    // common symbols, so symbols with greater alignment requirements cannot be
    // common.
    // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
    // alignments for common symbols via the aligncomm directive, so this
    // restriction only applies to MSVC environments.
    if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
        Context.getTypeAlignIfKnown(D->getType()) >
            Context.toBits(CharUnits::fromQuantity(32)))
      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;
    }
  
    if (const auto *FD = D->getAsFunction())
      if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
        return llvm::GlobalVariable::LinkOnceAnyLinkage;
  
    // We are guaranteed to have a strong definition somewhere else,
    // so we can use available_externally linkage.
    if (Linkage == GVA_AvailableExternally)
      return llvm::GlobalValue::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.
    //
    // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
    // so say that CUDA templates are either external (for kernels) or internal.
    // This lets llvm perform aggressive inter-procedural optimizations. For
    // -fgpu-rdc case, device function calls across multiple TU's are allowed,
    // therefore we need to follow the normal linkage paradigm.
    if (Linkage == GVA_StrongODR) {
      if (getLangOpts().AppleKext)
        return llvm::Function::ExternalLinkage;
      if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
          !getLangOpts().GPURelocatableDeviceCode)
        return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
                                            : llvm::Function::InternalLinkage;
      return llvm::Function::WeakODRLinkage;
    }
  
    // 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;
  
    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::CallBase *callSite = dyn_cast<llvm::CallBase>(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> newArgAttrs;
      llvm::AttributeList oldAttrs = callSite->getAttributes();
  
      // 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::Argument &A : newFn->args()) {
        if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
          dontTransform = true;
          break;
        }
  
        // Add any parameter attributes.
        newArgAttrs.push_back(oldAttrs.getParamAttrs(argNo));
        argNo++;
      }
      if (dontTransform)
        continue;
  
      // 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.
      SmallVector<llvm::OperandBundleDef, 1> newBundles;
      callSite->getOperandBundlesAsDefs(newBundles);
  
      llvm::CallBase *newCall;
      if (dyn_cast<llvm::CallInst>(callSite)) {
        newCall =
            llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
      } else {
        auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
        newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
                                           oldInvoke->getUnwindDest(), newArgs,
                                           newBundles, "", callSite);
      }
      newArgs.clear(); // for the next iteration
  
      if (!newCall->getType()->isVoidTy())
        newCall->takeName(callSite);
      newCall->setAttributes(
          llvm::AttributeList::get(newFn->getContext(), oldAttrs.getFnAttrs(),
                                   oldAttrs.getRetAttrs(), newArgAttrs));
      newCall->setCallingConv(callSite->getCallingConv());
  
      // Finally, remove the old call, replacing any uses with the new one.
      if (!callSite->use_empty())
        callSite->replaceAllUsesWith(newCall);
  
      // 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) {
    auto DK = VD->isThisDeclarationADefinition();
    if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
      return;
  
    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->getValueType() != Ty))
      GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
                                                     /*DontDefer=*/true,
                                                     ForDefinition));
  
    // 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);
  
    // FIXME: this is redundant with part of setFunctionDefinitionAttributes
    setGVProperties(Fn, GD);
  
    MaybeHandleStaticInExternC(D, Fn);
  
    maybeSetTrivialComdat(*D, *Fn);
  
    // Set CodeGen attributes that represent floating point environment.
    setLLVMFunctionFEnvAttributes(D, Fn);
  
    CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
  
    setNonAliasAttributes(GD, 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(), true);
    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) << 0;
      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;
    llvm::GlobalValue::LinkageTypes LT;
    if (isa<llvm::FunctionType>(DeclTy)) {
      Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
                                        /*ForVTable=*/false);
      LT = getFunctionLinkage(GD);
    } else {
      Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
                                      /*D=*/nullptr);
      if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
        LT = getLLVMLinkageVarDefinition(VD, D->getType().isConstQualified());
      else
        LT = getFunctionLinkage(GD);
    }
  
    // Create the new alias itself, but don't set a name yet.
    unsigned AS = Aliasee->getType()->getPointerAddressSpace();
    auto *GA =
        llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
  
    if (Entry) {
      if (GA->getAliasee() == Entry) {
        Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
        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);
  
    SetCommonAttributes(GD, GA);
  }
  
  void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
    const auto *D = cast<ValueDecl>(GD.getDecl());
    const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
    assert(IFA && "Not an ifunc?");
  
    StringRef MangledName = getMangledName(GD);
  
    if (IFA->getResolver() == MangledName) {
      Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
      return;
    }
  
    // Report an error if some definition overrides ifunc.
    llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
    if (Entry && !Entry->isDeclaration()) {
      GlobalDecl OtherGD;
      if (lookupRepresentativeDecl(MangledName, OtherGD) &&
          DiagnosedConflictingDefinitions.insert(GD).second) {
        Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
            << MangledName;
        Diags.Report(OtherGD.getDecl()->getLocation(),
                     diag::note_previous_definition);
      }
      return;
    }
  
    Aliases.push_back(GD);
  
    llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
    llvm::Constant *Resolver =
        GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
                                /*ForVTable=*/false);
    llvm::GlobalIFunc *GIF =
        llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
                                  "", Resolver, &getModule());
    if (Entry) {
      if (GIF->getResolver() == Entry) {
        Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
        return;
      }
      assert(Entry->isDeclaration());
  
      // If there is a declaration in the module, then we had an extern followed
      // by the ifunc, as in:
      //   extern int test();
      //   ...
      //   int test() __attribute__((ifunc("resolver")));
      //
      // Remove it and replace uses of it with the ifunc.
      GIF->takeName(Entry);
  
      Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
                                                            Entry->getType()));
      Entry->eraseFromParent();
    } else
      GIF->setName(MangledName);
  
    SetCommonAttributes(GD, GIF);
  }
  
  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<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
    const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
    llvm::UTF16 *ToPtr = &ToBuf[0];
  
    (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
                                   ToPtr + NumBytes, llvm::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;
  }
  
  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 };
  
    const ASTContext &Context = getContext();
    const llvm::Triple &Triple = getTriple();
  
    const auto CFRuntime = getLangOpts().CFRuntime;
    const bool IsSwiftABI =
        static_cast<unsigned>(CFRuntime) >=
        static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
    const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
  
    // If we don't already have it, get __CFConstantStringClassReference.
    if (!CFConstantStringClassRef) {
      const char *CFConstantStringClassName = "__CFConstantStringClassReference";
      llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
      Ty = llvm::ArrayType::get(Ty, 0);
  
      switch (CFRuntime) {
      default: break;
      case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
      case LangOptions::CoreFoundationABI::Swift5_0:
        CFConstantStringClassName =
            Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
                                : "$s10Foundation19_NSCFConstantStringCN";
        Ty = IntPtrTy;
        break;
      case LangOptions::CoreFoundationABI::Swift4_2:
        CFConstantStringClassName =
            Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
                                : "$S10Foundation19_NSCFConstantStringCN";
        Ty = IntPtrTy;
        break;
      case LangOptions::CoreFoundationABI::Swift4_1:
        CFConstantStringClassName =
            Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
                                : "__T010Foundation19_NSCFConstantStringCN";
        Ty = IntPtrTy;
        break;
      }
  
      llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
  
      if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
        llvm::GlobalValue *GV = nullptr;
  
        if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
          IdentifierInfo &II = Context.Idents.get(GV->getName());
          TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
          DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
  
          const VarDecl *VD = nullptr;
          for (const auto *Result : DC->lookup(&II))
            if ((VD = dyn_cast<VarDecl>(Result)))
              break;
  
          if (Triple.isOSBinFormatELF()) {
            if (!VD)
              GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
          } else {
            GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
            if (!VD || !VD->hasAttr<DLLExportAttr>())
              GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
            else
              GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
          }
  
          setDSOLocal(GV);
        }
      }
  
      // Decay array -> ptr
      CFConstantStringClassRef =
          IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
                     : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
    }
  
    QualType CFTy = Context.getCFConstantStringType();
  
    auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
  
    ConstantInitBuilder Builder(*this);
    auto Fields = Builder.beginStruct(STy);
  
    // Class pointer.
    Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
  
    // Flags.
    if (IsSwiftABI) {
      Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
      Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
    } else {
      Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 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(llvm::GlobalValue::UnnamedAddr::Global);
    // Don't enforce the target's minimum global alignment, since the only use
    // of the string is via this class initializer.
    CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
                              : Context.getTypeAlignInChars(Context.CharTy);
    GV->setAlignment(Align.getAsAlign());
  
    // 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 (Triple.isOSBinFormatMachO())
      GV->setSection(isUTF16 ? "__TEXT,__ustring"
                             : "__TEXT,__cstring,cstring_literals");
    // Make sure the literal ends up in .rodata to allow for safe ICF and for
    // the static linker to adjust permissions to read-only later on.
    else if (Triple.isOSBinFormatELF())
      GV->setSection(".rodata");
  
    // String.
    llvm::Constant *Str =
        llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
  
    if (isUTF16)
      // Cast the UTF16 string to the correct type.
      Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
    Fields.add(Str);
  
    // String length.
    llvm::IntegerType *LengthTy =
        llvm::IntegerType::get(getModule().getContext(),
                               Context.getTargetInfo().getLongWidth());
    if (IsSwiftABI) {
      if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
          CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
        LengthTy = Int32Ty;
      else
        LengthTy = IntPtrTy;
    }
    Fields.addInt(LengthTy, StringLength);
  
    // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
    // properly aligned on 32-bit platforms.
    CharUnits Alignment =
        IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
  
    // The struct.
    GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
                                      /*isConstant=*/false,
                                      llvm::GlobalVariable::PrivateLinkage);
    GV->addAttribute("objc_arc_inert");
    switch (Triple.getObjectFormat()) {
    case llvm::Triple::UnknownObjectFormat:
      llvm_unreachable("unknown file format");
    case llvm::Triple::GOFF:
      llvm_unreachable("GOFF is not yet implemented");
    case llvm::Triple::XCOFF:
      llvm_unreachable("XCOFF is not yet implemented");
    case llvm::Triple::COFF:
    case llvm::Triple::ELF:
    case llvm::Triple::Wasm:
      GV->setSection("cfstring");
      break;
    case llvm::Triple::MachO:
      GV->setSection("__DATA,__cfstring");
      break;
    }
    Entry.second = GV;
  
    return ConstantAddress(GV, Alignment);
  }
  
  bool CodeGenModule::getExpressionLocationsEnabled() const {
    return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
  }
  
  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), nullptr, 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) {
    unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
        CGM.GetGlobalConstantAddressSpace());
  
    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.getAsAlign());
    GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
    if (GV->isWeakForLinker()) {
      assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
      GV->setComdat(M.getOrInsertComdat(GV->getName()));
    }
    CGM.setDSOLocal(GV);
  
    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.getAsAlign());
        return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
                               Alignment);
      }
    }
  
    SmallString<256> MangledNameBuffer;
    StringRef GlobalVariableName;
    llvm::GlobalValue::LinkageTypes LT;
  
    // Mangle the string literal if that's how the ABI merges duplicate strings.
    // Don't do it if they are writable, since we don't want writes in one TU to
    // affect strings in another.
    if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
        !LangOpts.WritableStrings) {
      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(castStringLiteralToDefaultAddressSpace(*this, 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.getAsAlign());
        return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, 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(castStringLiteralToDefaultAddressSpace(*this, 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->getSubExpr())
      MaterializedType = E->getType();
  
    CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
  
    auto InsertResult = MaterializedGlobalTemporaryMap.insert({E, nullptr});
    if (!InsertResult.second) {
      // We've seen this before: either we already created it or we're in the
      // process of doing so.
      if (!InsertResult.first->second) {
        // We recursively re-entered this function, probably during emission of
        // the initializer. Create a placeholder. We'll clean this up in the
        // outer call, at the end of this function.
        llvm::Type *Type = getTypes().ConvertTypeForMem(MaterializedType);
        InsertResult.first->second = new llvm::GlobalVariable(
            getModule(), Type, false, llvm::GlobalVariable::InternalLinkage,
            nullptr);
      }
      return ConstantAddress(InsertResult.first->second, 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 && VD && VD->evaluateValue()) {
      // If the initializer of the extending declaration is a constant
      // initializer, we should 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 = E->getOrCreateValue(false);
    }
  
    // Try evaluating it now, it might have a constant initializer.
    Expr::EvalResult EvalResult;
    if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
        !EvalResult.hasSideEffects())
      Value = &EvalResult.Val;
  
    LangAS AddrSpace =
        VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
  
    Optional<ConstantEmitter> emitter;
    llvm::Constant *InitialValue = nullptr;
    bool Constant = false;
    llvm::Type *Type;
    if (Value) {
      // The temporary has a constant initializer, use it.
      emitter.emplace(*this);
      InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
                                                 MaterializedType);
      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 multiple 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;
      }
    }
    auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
    auto *GV = new llvm::GlobalVariable(
        getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
        /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
    if (emitter) emitter->finalize(GV);
    setGVProperties(GV, VD);
    GV->setAlignment(Align.getAsAlign());
    if (supportsCOMDAT() && GV->isWeakForLinker())
      GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
    if (VD->getTLSKind())
      setTLSMode(GV, *VD);
    llvm::Constant *CV = GV;
    if (AddrSpace != LangAS::Default)
      CV = getTargetCodeGenInfo().performAddrSpaceCast(
          *this, GV, AddrSpace, LangAS::Default,
          Type->getPointerTo(
              getContext().getTargetAddressSpace(LangAS::Default)));
  
    // Update the map with the new temporary. If we created a placeholder above,
    // replace it with the new global now.
    llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
    if (Entry) {
      Entry->replaceAllUsesWith(
          llvm::ConstantExpr::getBitCast(CV, Entry->getType()));
      llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
    }
    Entry = CV;
  
    return ConstantAddress(CV, 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.
        auto *Getter = PID->getGetterMethodDecl();
        if (!Getter || Getter->isSynthesizedAccessorStub())
          CodeGenFunction(*this).GenerateObjCGetter(
              const_cast<ObjCImplementationDecl *>(D), PID);
        auto *Setter = PID->getSetterMethodDecl();
        if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
          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, /*isSynthesizedAccessorStub=*/false,
          /*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, /*isSynthesizedAccessorStub=*/false,
        /*isImplicitlyDeclared=*/true,
        /*isDefined=*/false, ObjCMethodDecl::Required);
    D->addInstanceMethod(CTORMethod);
    CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
    D->setHasNonZeroConstructors(true);
  }
  
  // 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;
    }
  
    EmitDeclContext(LSD);
  }
  
  void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
    for (auto *I : DC->decls()) {
      // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
      // are themselves considered "top-level", so EmitTopLevelDecl on an
      // ObjCImplDecl does not recursively visit them. We need to do that in
      // case they're nested inside another construct (LinkageSpecDecl /
      // ExportDecl) that does stop them from being considered "top-level".
      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->isTemplated())
      return;
  
    // Consteval function shouldn't be emitted.
    if (auto *FD = dyn_cast<FunctionDecl>(D))
      if (FD->isConsteval())
        return;
  
    switch (D->getKind()) {
    case Decl::CXXConversion:
    case Decl::CXXMethod:
    case Decl::Function:
      EmitGlobal(cast<FunctionDecl>(D));
      // Always provide some coverage mapping
      // even for the functions that aren't emitted.
      AddDeferredUnusedCoverageMapping(D);
      break;
  
    case Decl::CXXDeductionGuide:
      // Function-like, but does not result in code emission.
      break;
  
    case Decl::Var:
    case Decl::Decomposition:
    case Decl::VarTemplateSpecialization:
      EmitGlobal(cast<VarDecl>(D));
      if (auto *DD = dyn_cast<DecompositionDecl>(D))
        for (auto *B : DD->bindings())
          if (auto *HD = B->getHoldingVar())
            EmitGlobal(HD);
      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:
      EmitDeclContext(cast<NamespaceDecl>(D));
      break;
    case Decl::ClassTemplateSpecialization: {
      const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
      if (CGDebugInfo *DI = getModuleDebugInfo())
        if (Spec->getSpecializationKind() ==
                TSK_ExplicitInstantiationDefinition &&
            Spec->hasDefinition())
          DI->completeTemplateDefinition(*Spec);
    } LLVM_FALLTHROUGH;
    case Decl::CXXRecord: {
      CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
      if (CGDebugInfo *DI = getModuleDebugInfo()) {
        if (CRD->hasDefinition())
          DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
        if (auto *ES = D->getASTContext().getExternalSource())
          if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
            DI->completeUnusedClass(*CRD);
      }
      // Emit any static data members, they may be definitions.
      for (auto *I : CRD->decls())
        if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
          EmitTopLevelDecl(I);
      break;
    }
      // No code generation needed.
    case Decl::UsingShadow:
    case Decl::ClassTemplate:
    case Decl::VarTemplate:
    case Decl::Concept:
    case Decl::VarTemplatePartialSpecialization:
    case Decl::FunctionTemplate:
    case Decl::TypeAliasTemplate:
    case Decl::Block:
    case Decl::Empty:
    case Decl::Binding:
      break;
    case Decl::Using:          // using X; [C++]
      if (CGDebugInfo *DI = getModuleDebugInfo())
          DI->EmitUsingDecl(cast<UsingDecl>(*D));
      break;
    case Decl::UsingEnum: // using enum X; [C++]
      if (CGDebugInfo *DI = getModuleDebugInfo())
        DI->EmitUsingEnumDecl(cast<UsingEnumDecl>(*D));
      break;
    case Decl::NamespaceAlias:
      if (CGDebugInfo *DI = getModuleDebugInfo())
          DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
      break;
    case Decl::UsingDirective: // using namespace X; [C++]
      if (CGDebugInfo *DI = getModuleDebugInfo())
        DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
      break;
    case Decl::CXXConstructor:
      getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
      break;
    case Decl::CXXDestructor:
      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().hasReducedDebugInfo())
          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::PragmaComment: {
      const auto *PCD = cast<PragmaCommentDecl>(D);
      switch (PCD->getCommentKind()) {
      case PCK_Unknown:
        llvm_unreachable("unexpected pragma comment kind");
      case PCK_Linker:
        AppendLinkerOptions(PCD->getArg());
        break;
      case PCK_Lib:
          AddDependentLib(PCD->getArg());
        break;
      case PCK_Compiler:
      case PCK_ExeStr:
      case PCK_User:
        break; // We ignore all of these.
      }
      break;
    }
  
    case Decl::PragmaDetectMismatch: {
      const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
      AddDetectMismatch(PDMD->getName(), PDMD->getValue());
      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;
      // File-scope asm is ignored during device-side OpenMP compilation.
      if (LangOpts.OpenMPIsDevice)
        break;
      // File-scope asm is ignored during device-side SYCL compilation.
      if (LangOpts.SYCLIsDevice)
        break;
      auto *AD = cast<FileScopeAsmDecl>(D);
      getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
      break;
    }
  
    case Decl::Import: {
      auto *Import = cast<ImportDecl>(D);
  
      // If we've already imported this module, we're done.
      if (!ImportedModules.insert(Import->getImportedModule()))
        break;
  
      // Emit debug information for direct imports.
      if (!Import->getImportedOwningModule()) {
        if (CGDebugInfo *DI = getModuleDebugInfo())
          DI->EmitImportDecl(*Import);
      }
  
      // Find all of the submodules and emit the module initializers.
      llvm::SmallPtrSet<clang::Module *, 16> Visited;
      SmallVector<clang::Module *, 16> Stack;
      Visited.insert(Import->getImportedModule());
      Stack.push_back(Import->getImportedModule());
  
      while (!Stack.empty()) {
        clang::Module *Mod = Stack.pop_back_val();
        if (!EmittedModuleInitializers.insert(Mod).second)
          continue;
  
        for (auto *D : Context.getModuleInitializers(Mod))
          EmitTopLevelDecl(D);
  
        // 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 emit
          // the initializers.
          if ((*Sub)->IsExplicit)
            continue;
  
          if (Visited.insert(*Sub).second)
            Stack.push_back(*Sub);
        }
      }
      break;
    }
  
    case Decl::Export:
      EmitDeclContext(cast<ExportDecl>(D));
      break;
  
    case Decl::OMPThreadPrivate:
      EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
      break;
  
    case Decl::OMPAllocate:
      EmitOMPAllocateDecl(cast<OMPAllocateDecl>(D));
      break;
  
    case Decl::OMPDeclareReduction:
      EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
      break;
  
    case Decl::OMPDeclareMapper:
      EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
      break;
  
    case Decl::OMPRequires:
      EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
      break;
  
    case Decl::Typedef:
    case Decl::TypeAlias: // using foo = bar; [C++11]
      if (CGDebugInfo *DI = getModuleDebugInfo())
        DI->EmitAndRetainType(
            getContext().getTypedefType(cast<TypedefNameDecl>(D)));
      break;
  
    case Decl::Record:
      if (CGDebugInfo *DI = getModuleDebugInfo())
        if (cast<RecordDecl>(D)->getDefinition())
          DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
      break;
  
    case Decl::Enum:
      if (CGDebugInfo *DI = getModuleDebugInfo())
        if (cast<EnumDecl>(D)->getDefinition())
          DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
      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())
        break;
      SourceManager &SM = getContext().getSourceManager();
      if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
        break;
      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() {
    // We call takeVector() here to avoid use-after-free.
    // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
    // we deserialize function bodies to emit coverage info for them, and that
    // deserializes more declarations. How should we handle that case?
    for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
      if (!Entry.second)
        continue;
      const Decl *D = Entry.first;
      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;
      };
    }
  }
  
  void CodeGenModule::EmitMainVoidAlias() {
    // In order to transition away from "__original_main" gracefully, emit an
    // alias for "main" in the no-argument case so that libc can detect when
    // new-style no-argument main is in used.
    if (llvm::Function *F = getModule().getFunction("main")) {
      if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
          F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth()))
        addUsedGlobal(llvm::GlobalAlias::create("__main_void", F));
    }
  }
  
  /// 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() {
    if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
      return;
    for (auto &I : StaticExternCValues) {
      IdentifierInfo *Name = I.first;
      llvm::GlobalValue *Val = I.second;
      if (Val && !getModule().getNamedValue(Name->getName()))
        addCompilerUsedGlobal(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::EmitCommandLineMetadata() {
    llvm::NamedMDNode *CommandLineMetadata =
      TheModule.getOrInsertNamedMetadata("llvm.commandline");
    std::string CommandLine = getCodeGenOpts().RecordCommandLine;
    llvm::LLVMContext &Ctx = TheModule.getContext();
  
    llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
    CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
  }
  
  void CodeGenModule::EmitCoverageFile() {
    if (getCodeGenOpts().CoverageDataFile.empty() &&
        getCodeGenOpts().CoverageNotesFile.empty())
      return;
  
    llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
    if (!CUNode)
      return;
  
    llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
    llvm::LLVMContext &Ctx = TheModule.getContext();
    auto *CoverageDataFile =
        llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
    auto *CoverageNotesFile =
        llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
    for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
      llvm::MDNode *CU = CUNode->getOperand(i);
      llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
      GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
    }
  }
  
  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) || getLangOpts().CUDAIsDevice ||
        (getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
         getTriple().isNVPTX()))
      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) {
    // Do not emit threadprivates in simd-only mode.
    if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
      return;
    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->getBeginLoc(), PerformInit))
        CXXGlobalInits.push_back(InitFunction);
    }
  }
  
  llvm::Metadata *
  CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
                                              StringRef Suffix) {
    llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
    if (InternalId)
      return InternalId;
  
    if (isExternallyVisible(T->getLinkage())) {
      std::string OutName;
      llvm::raw_string_ostream Out(OutName);
      getCXXABI().getMangleContext().mangleTypeName(T, Out);
      Out << Suffix;
  
      InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
    } else {
      InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
                                             llvm::ArrayRef<llvm::Metadata *>());
    }
  
    return InternalId;
  }
  
  llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
    return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
  }
  
  llvm::Metadata *
  CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
    return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
  }
  
  // Generalize pointer types to a void pointer with the qualifiers of the
  // originally pointed-to type, e.g. 'const char *' and 'char * const *'
  // generalize to 'const void *' while 'char *' and 'const char **' generalize to
  // 'void *'.
  static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
    if (!Ty->isPointerType())
      return Ty;
  
    return Ctx.getPointerType(
        QualType(Ctx.VoidTy).withCVRQualifiers(
            Ty->getPointeeType().getCVRQualifiers()));
  }
  
  // Apply type generalization to a FunctionType's return and argument types
  static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
    if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
      SmallVector<QualType, 8> GeneralizedParams;
      for (auto &Param : FnType->param_types())
        GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
  
      return Ctx.getFunctionType(
          GeneralizeType(Ctx, FnType->getReturnType()),
          GeneralizedParams, FnType->getExtProtoInfo());
    }
  
    if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
      return Ctx.getFunctionNoProtoType(
          GeneralizeType(Ctx, FnType->getReturnType()));
  
    llvm_unreachable("Encountered unknown FunctionType");
  }
  
  llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
    return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
                                        GeneralizedMetadataIdMap, ".generalized");
  }
  
  /// Returns whether this module needs the "all-vtables" type identifier.
  bool CodeGenModule::NeedAllVtablesTypeId() const {
    // Returns true if at least one of vtable-based CFI checkers is enabled and
    // is not in the trapping mode.
    return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
             !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
            (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
             !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
            (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
             !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
            (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
             !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
  }
  
  void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
                                            CharUnits Offset,
                                            const CXXRecordDecl *RD) {
    llvm::Metadata *MD =
        CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
    VTable->addTypeMetadata(Offset.getQuantity(), MD);
  
    if (CodeGenOpts.SanitizeCfiCrossDso)
      if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
        VTable->addTypeMetadata(Offset.getQuantity(),
                                llvm::ConstantAsMetadata::get(CrossDsoTypeId));
  
    if (NeedAllVtablesTypeId()) {
      llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
      VTable->addTypeMetadata(Offset.getQuantity(), MD);
    }
  }
  
  llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
    if (!SanStats)
      SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
  
    return *SanStats;
  }
  
  llvm::Value *
  CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
                                                    CodeGenFunction &CGF) {
    llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
    auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
    auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
    auto *Call = CGF.EmitRuntimeCall(
        CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
    return Call;
  }
  
  CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
      QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
    return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
                                   /* forPointeeType= */ true);
  }
  
  CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
                                                   LValueBaseInfo *BaseInfo,
                                                   TBAAAccessInfo *TBAAInfo,
                                                   bool forPointeeType) {
    if (TBAAInfo)
      *TBAAInfo = getTBAAAccessInfo(T);
  
    // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
    // that doesn't return the information we need to compute BaseInfo.
  
    // Honor alignment typedef attributes even on incomplete types.
    // We also honor them straight for C++ class types, even as pointees;
    // there's an expressivity gap here.
    if (auto TT = T->getAs<TypedefType>()) {
      if (auto Align = TT->getDecl()->getMaxAlignment()) {
        if (BaseInfo)
          *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
        return getContext().toCharUnitsFromBits(Align);
      }
    }
  
    bool AlignForArray = T->isArrayType();
  
    // Analyze the base element type, so we don't get confused by incomplete
    // array types.
    T = getContext().getBaseElementType(T);
  
    if (T->isIncompleteType()) {
      // We could try to replicate the logic from
      // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
      // type is incomplete, so it's impossible to test. We could try to reuse
      // getTypeAlignIfKnown, but that doesn't return the information we need
      // to set BaseInfo.  So just ignore the possibility that the alignment is
      // greater than one.
      if (BaseInfo)
        *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
      return CharUnits::One();
    }
  
    if (BaseInfo)
      *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
  
    CharUnits Alignment;
    const CXXRecordDecl *RD;
    if (T.getQualifiers().hasUnaligned()) {
      Alignment = CharUnits::One();
    } else if (forPointeeType && !AlignForArray &&
               (RD = T->getAsCXXRecordDecl())) {
      // For C++ class pointees, we don't know whether we're pointing at a
      // base or a complete object, so we generally need to use the
      // non-virtual alignment.
      Alignment = getClassPointerAlignment(RD);
    } else {
      Alignment = getContext().getTypeAlignInChars(T);
    }
  
    // Cap to the global maximum type alignment unless the alignment
    // was somehow explicit on the type.
    if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
      if (Alignment.getQuantity() > MaxAlign &&
          !getContext().isAlignmentRequired(T))
        Alignment = CharUnits::fromQuantity(MaxAlign);
    }
    return Alignment;
  }
  
  bool CodeGenModule::stopAutoInit() {
    unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
    if (StopAfter) {
      // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
      // used
      if (NumAutoVarInit >= StopAfter) {
        return true;
      }
      if (!NumAutoVarInit) {
        unsigned DiagID = getDiags().getCustomDiagID(
            DiagnosticsEngine::Warning,
            "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
            "number of times ftrivial-auto-var-init=%1 gets applied.");
        getDiags().Report(DiagID)
            << StopAfter
            << (getContext().getLangOpts().getTrivialAutoVarInit() ==
                        LangOptions::TrivialAutoVarInitKind::Zero
                    ? "zero"
                    : "pattern");
      }
      ++NumAutoVarInit;
    }
    return false;
  }
  
  void CodeGenModule::printPostfixForExternalizedStaticVar(
      llvm::raw_ostream &OS) const {
    OS << "__static__" << getContext().getCUIDHash();
  }
  