text: //===--- FrontendActions.cpp ----------------------------------------------===//
  //
  // 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
  //
  //===----------------------------------------------------------------------===//
  
  #include "clang/Frontend/FrontendActions.h"
  #include "clang/AST/ASTConsumer.h"
  #include "clang/Basic/FileManager.h"
  #include "clang/Basic/LangStandard.h"
  #include "clang/Frontend/ASTConsumers.h"
  #include "clang/Frontend/CompilerInstance.h"
  #include "clang/Frontend/FrontendDiagnostic.h"
  #include "clang/Frontend/MultiplexConsumer.h"
  #include "clang/Frontend/Utils.h"
  #include "clang/Lex/DependencyDirectivesSourceMinimizer.h"
  #include "clang/Lex/HeaderSearch.h"
  #include "clang/Lex/Preprocessor.h"
  #include "clang/Lex/PreprocessorOptions.h"
  #include "clang/Sema/TemplateInstCallback.h"
  #include "clang/Serialization/ASTReader.h"
  #include "clang/Serialization/ASTWriter.h"
  #include "llvm/Support/FileSystem.h"
  #include "llvm/Support/MemoryBuffer.h"
  #include "llvm/Support/Path.h"
  #include "llvm/Support/YAMLTraits.h"
  #include "llvm/Support/raw_ostream.h"
  #include <memory>
  #include <system_error>
  
  using namespace clang;
  
  namespace {
  CodeCompleteConsumer *GetCodeCompletionConsumer(CompilerInstance &CI) {
    return CI.hasCodeCompletionConsumer() ? &CI.getCodeCompletionConsumer()
                                          : nullptr;
  }
  
  void EnsureSemaIsCreated(CompilerInstance &CI, FrontendAction &Action) {
    if (Action.hasCodeCompletionSupport() &&
        !CI.getFrontendOpts().CodeCompletionAt.FileName.empty())
      CI.createCodeCompletionConsumer();
  
    if (!CI.hasSema())
      CI.createSema(Action.getTranslationUnitKind(),
                    GetCodeCompletionConsumer(CI));
  }
  } // namespace
  
  //===----------------------------------------------------------------------===//
  // Custom Actions
  //===----------------------------------------------------------------------===//
  
  std::unique_ptr<ASTConsumer>
  InitOnlyAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    return std::make_unique<ASTConsumer>();
  }
  
  void InitOnlyAction::ExecuteAction() {
  }
  
  //===----------------------------------------------------------------------===//
  // AST Consumer Actions
  //===----------------------------------------------------------------------===//
  
  std::unique_ptr<ASTConsumer>
  ASTPrintAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    if (std::unique_ptr<raw_ostream> OS =
            CI.createDefaultOutputFile(false, InFile))
      return CreateASTPrinter(std::move(OS), CI.getFrontendOpts().ASTDumpFilter);
    return nullptr;
  }
  
  std::unique_ptr<ASTConsumer>
  ASTDumpAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    const FrontendOptions &Opts = CI.getFrontendOpts();
    return CreateASTDumper(nullptr /*Dump to stdout.*/, Opts.ASTDumpFilter,
                           Opts.ASTDumpDecls, Opts.ASTDumpAll,
                           Opts.ASTDumpLookups, Opts.ASTDumpFormat);
  }
  
  std::unique_ptr<ASTConsumer>
  ASTDeclListAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    return CreateASTDeclNodeLister();
  }
  
  std::unique_ptr<ASTConsumer>
  ASTViewAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    return CreateASTViewer();
  }
  
  std::unique_ptr<ASTConsumer>
  GeneratePCHAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    std::string Sysroot;
    if (!ComputeASTConsumerArguments(CI, /*ref*/ Sysroot))
      return nullptr;
  
    std::string OutputFile;
    std::unique_ptr<raw_pwrite_stream> OS =
        CreateOutputFile(CI, InFile, /*ref*/ OutputFile);
    if (!OS)
      return nullptr;
  
    if (!CI.getFrontendOpts().RelocatablePCH)
      Sysroot.clear();
  
    const auto &FrontendOpts = CI.getFrontendOpts();
    auto Buffer = std::make_shared<PCHBuffer>();
    std::vector<std::unique_ptr<ASTConsumer>> Consumers;
    Consumers.push_back(std::make_unique<PCHGenerator>(
        CI.getPreprocessor(), CI.getModuleCache(), OutputFile, Sysroot, Buffer,
        FrontendOpts.ModuleFileExtensions,
        CI.getPreprocessorOpts().AllowPCHWithCompilerErrors,
        FrontendOpts.IncludeTimestamps, +CI.getLangOpts().CacheGeneratedPCH));
    Consumers.push_back(CI.getPCHContainerWriter().CreatePCHContainerGenerator(
        CI, InFile, OutputFile, std::move(OS), Buffer));
  
    return std::make_unique<MultiplexConsumer>(std::move(Consumers));
  }
  
  bool GeneratePCHAction::ComputeASTConsumerArguments(CompilerInstance &CI,
                                                      std::string &Sysroot) {
    Sysroot = CI.getHeaderSearchOpts().Sysroot;
    if (CI.getFrontendOpts().RelocatablePCH && Sysroot.empty()) {
      CI.getDiagnostics().Report(diag::err_relocatable_without_isysroot);
      return false;
    }
  
    return true;
  }
  
  std::unique_ptr<llvm::raw_pwrite_stream>
  GeneratePCHAction::CreateOutputFile(CompilerInstance &CI, StringRef InFile,
                                      std::string &OutputFile) {
    // We use createOutputFile here because this is exposed via libclang, and we
    // must disable the RemoveFileOnSignal behavior.
    // We use a temporary to avoid race conditions.
    std::unique_ptr<raw_pwrite_stream> OS =
        CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
                            /*RemoveFileOnSignal=*/false, InFile,
                            /*Extension=*/"", CI.getFrontendOpts().UseTemporary);
    if (!OS)
      return nullptr;
  
    OutputFile = CI.getFrontendOpts().OutputFile;
    return OS;
  }
  
  bool GeneratePCHAction::shouldEraseOutputFiles() {
    if (getCompilerInstance().getPreprocessorOpts().AllowPCHWithCompilerErrors)
      return false;
    return ASTFrontendAction::shouldEraseOutputFiles();
  }
  
  bool GeneratePCHAction::BeginSourceFileAction(CompilerInstance &CI) {
    CI.getLangOpts().CompilingPCH = true;
    return true;
  }
  
  std::unique_ptr<ASTConsumer>
  GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
                                          StringRef InFile) {
    std::unique_ptr<raw_pwrite_stream> OS = CreateOutputFile(CI, InFile);
    if (!OS)
      return nullptr;
  
    std::string OutputFile = CI.getFrontendOpts().OutputFile;
    std::string Sysroot;
  
    auto Buffer = std::make_shared<PCHBuffer>();
    std::vector<std::unique_ptr<ASTConsumer>> Consumers;
  
    Consumers.push_back(std::make_unique<PCHGenerator>(
        CI.getPreprocessor(), CI.getModuleCache(), OutputFile, Sysroot, Buffer,
        CI.getFrontendOpts().ModuleFileExtensions,
        /*AllowASTWithErrors=*/false,
        /*IncludeTimestamps=*/
        +CI.getFrontendOpts().BuildingImplicitModule,
        /*ShouldCacheASTInMemory=*/
        +CI.getFrontendOpts().BuildingImplicitModule));
    Consumers.push_back(CI.getPCHContainerWriter().CreatePCHContainerGenerator(
        CI, InFile, OutputFile, std::move(OS), Buffer));
    return std::make_unique<MultiplexConsumer>(std::move(Consumers));
  }
  
  bool GenerateModuleFromModuleMapAction::BeginSourceFileAction(
      CompilerInstance &CI) {
    if (!CI.getLangOpts().Modules) {
      CI.getDiagnostics().Report(diag::err_module_build_requires_fmodules);
      return false;
    }
  
    return GenerateModuleAction::BeginSourceFileAction(CI);
  }
  
  std::unique_ptr<raw_pwrite_stream>
  GenerateModuleFromModuleMapAction::CreateOutputFile(CompilerInstance &CI,
                                                      StringRef InFile) {
    // If no output file was provided, figure out where this module would go
    // in the module cache.
    if (CI.getFrontendOpts().OutputFile.empty()) {
      StringRef ModuleMapFile = CI.getFrontendOpts().OriginalModuleMap;
      if (ModuleMapFile.empty())
        ModuleMapFile = InFile;
  
      HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
      CI.getFrontendOpts().OutputFile =
          HS.getCachedModuleFileName(CI.getLangOpts().CurrentModule,
                                     ModuleMapFile);
    }
  
    // We use createOutputFile here because this is exposed via libclang, and we
    // must disable the RemoveFileOnSignal behavior.
    // We use a temporary to avoid race conditions.
    return CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
                               /*RemoveFileOnSignal=*/false, InFile,
                               /*Extension=*/"", /*UseTemporary=*/true,
                               /*CreateMissingDirectories=*/true);
  }
  
  bool GenerateModuleInterfaceAction::BeginSourceFileAction(
      CompilerInstance &CI) {
    if (!CI.getLangOpts().ModulesTS && !CI.getLangOpts().CPlusPlusModules) {
      CI.getDiagnostics().Report(diag::err_module_interface_requires_cpp_modules);
      return false;
    }
  
    CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
  
    return GenerateModuleAction::BeginSourceFileAction(CI);
  }
  
  std::unique_ptr<raw_pwrite_stream>
  GenerateModuleInterfaceAction::CreateOutputFile(CompilerInstance &CI,
                                                  StringRef InFile) {
    return CI.createDefaultOutputFile(/*Binary=*/true, InFile, "pcm");
  }
  
  bool GenerateHeaderModuleAction::PrepareToExecuteAction(
      CompilerInstance &CI) {
    if (!CI.getLangOpts().Modules) {
      CI.getDiagnostics().Report(diag::err_header_module_requires_modules);
      return false;
    }
  
    auto &Inputs = CI.getFrontendOpts().Inputs;
    if (Inputs.empty())
      return GenerateModuleAction::BeginInvocation(CI);
  
    auto Kind = Inputs[0].getKind();
  
    // Convert the header file inputs into a single module input buffer.
    SmallString<256> HeaderContents;
    ModuleHeaders.reserve(Inputs.size());
    for (const FrontendInputFile &FIF : Inputs) {
      // FIXME: We should support re-compiling from an AST file.
      if (FIF.getKind().getFormat() != InputKind::Source || !FIF.isFile()) {
        CI.getDiagnostics().Report(diag::err_module_header_file_not_found)
            << (FIF.isFile() ? FIF.getFile()
                             : FIF.getBuffer()->getBufferIdentifier());
        return true;
      }
  
      HeaderContents += "#include \"";
      HeaderContents += FIF.getFile();
      HeaderContents += "\"\n";
      ModuleHeaders.push_back(FIF.getFile());
    }
    Buffer = llvm::MemoryBuffer::getMemBufferCopy(
        HeaderContents, Module::getModuleInputBufferName());
  
    // Set that buffer up as our "real" input.
    Inputs.clear();
    Inputs.push_back(FrontendInputFile(Buffer.get(), Kind, /*IsSystem*/false));
  
    return GenerateModuleAction::PrepareToExecuteAction(CI);
  }
  
  bool GenerateHeaderModuleAction::BeginSourceFileAction(
      CompilerInstance &CI) {
    CI.getLangOpts().setCompilingModule(LangOptions::CMK_HeaderModule);
  
    // Synthesize a Module object for the given headers.
    auto &HS = CI.getPreprocessor().getHeaderSearchInfo();
    SmallVector<Module::Header, 16> Headers;
    for (StringRef Name : ModuleHeaders) {
      const DirectoryLookup *CurDir = nullptr;
      Optional<FileEntryRef> FE = HS.LookupFile(
          Name, SourceLocation(), /*Angled*/ false, nullptr, CurDir, None,
          nullptr, nullptr, nullptr, nullptr, nullptr, nullptr);
      if (!FE) {
        CI.getDiagnostics().Report(diag::err_module_header_file_not_found)
          << Name;
        continue;
      }
      Headers.push_back({Name, &FE->getFileEntry()});
    }
    HS.getModuleMap().createHeaderModule(CI.getLangOpts().CurrentModule, Headers);
  
    return GenerateModuleAction::BeginSourceFileAction(CI);
  }
  
  std::unique_ptr<raw_pwrite_stream>
  GenerateHeaderModuleAction::CreateOutputFile(CompilerInstance &CI,
                                               StringRef InFile) {
    return CI.createDefaultOutputFile(/*Binary=*/true, InFile, "pcm");
  }
  
  SyntaxOnlyAction::~SyntaxOnlyAction() {
  }
  
  std::unique_ptr<ASTConsumer>
  SyntaxOnlyAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    return std::make_unique<ASTConsumer>();
  }
  
  std::unique_ptr<ASTConsumer>
  DumpModuleInfoAction::CreateASTConsumer(CompilerInstance &CI,
                                          StringRef InFile) {
    return std::make_unique<ASTConsumer>();
  }
  
  std::unique_ptr<ASTConsumer>
  VerifyPCHAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    return std::make_unique<ASTConsumer>();
  }
  
  void VerifyPCHAction::ExecuteAction() {
    CompilerInstance &CI = getCompilerInstance();
    bool Preamble = CI.getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
    const std::string &Sysroot = CI.getHeaderSearchOpts().Sysroot;
    std::unique_ptr<ASTReader> Reader(new ASTReader(
        CI.getPreprocessor(), CI.getModuleCache(), &CI.getASTContext(),
        CI.getPCHContainerReader(), CI.getFrontendOpts().ModuleFileExtensions,
        Sysroot.empty() ? "" : Sysroot.c_str(),
        /*DisableValidation*/ false,
        /*AllowPCHWithCompilerErrors*/ false,
        /*AllowConfigurationMismatch*/ true,
        /*ValidateSystemInputs*/ true));
  
    Reader->ReadAST(getCurrentFile(),
                    Preamble ? serialization::MK_Preamble
                             : serialization::MK_PCH,
                    SourceLocation(),
                    ASTReader::ARR_ConfigurationMismatch);
  }
  
  namespace {
  struct TemplightEntry {
    std::string Name;
    std::string Kind;
    std::string Event;
    std::string DefinitionLocation;
    std::string PointOfInstantiation;
  };
  } // namespace
  
  namespace llvm {
  namespace yaml {
  template <> struct MappingTraits<TemplightEntry> {
    static void mapping(IO &io, TemplightEntry &fields) {
      io.mapRequired("name", fields.Name);
      io.mapRequired("kind", fields.Kind);
      io.mapRequired("event", fields.Event);
      io.mapRequired("orig", fields.DefinitionLocation);
      io.mapRequired("poi", fields.PointOfInstantiation);
    }
  };
  } // namespace yaml
  } // namespace llvm
  
  namespace {
  class DefaultTemplateInstCallback : public TemplateInstantiationCallback {
    using CodeSynthesisContext = Sema::CodeSynthesisContext;
  
  public:
    void initialize(const Sema &) override {}
  
    void finalize(const Sema &) override {}
  
    void atTemplateBegin(const Sema &TheSema,
                         const CodeSynthesisContext &Inst) override {
      displayTemplightEntry<true>(llvm::outs(), TheSema, Inst);
    }
  
    void atTemplateEnd(const Sema &TheSema,
                       const CodeSynthesisContext &Inst) override {
      displayTemplightEntry<false>(llvm::outs(), TheSema, Inst);
    }
  
  private:
    static std::string toString(CodeSynthesisContext::SynthesisKind Kind) {
      switch (Kind) {
      case CodeSynthesisContext::TemplateInstantiation:
        return "TemplateInstantiation";
      case CodeSynthesisContext::DefaultTemplateArgumentInstantiation:
        return "DefaultTemplateArgumentInstantiation";
      case CodeSynthesisContext::DefaultFunctionArgumentInstantiation:
        return "DefaultFunctionArgumentInstantiation";
      case CodeSynthesisContext::ExplicitTemplateArgumentSubstitution:
        return "ExplicitTemplateArgumentSubstitution";
      case CodeSynthesisContext::DeducedTemplateArgumentSubstitution:
        return "DeducedTemplateArgumentSubstitution";
      case CodeSynthesisContext::PriorTemplateArgumentSubstitution:
        return "PriorTemplateArgumentSubstitution";
      case CodeSynthesisContext::DefaultTemplateArgumentChecking:
        return "DefaultTemplateArgumentChecking";
      case CodeSynthesisContext::ExceptionSpecEvaluation:
        return "ExceptionSpecEvaluation";
      case CodeSynthesisContext::ExceptionSpecInstantiation:
        return "ExceptionSpecInstantiation";
      case CodeSynthesisContext::DeclaringSpecialMember:
        return "DeclaringSpecialMember";
      case CodeSynthesisContext::DeclaringImplicitEqualityComparison:
        return "DeclaringImplicitEqualityComparison";
      case CodeSynthesisContext::DefiningSynthesizedFunction:
        return "DefiningSynthesizedFunction";
      case CodeSynthesisContext::RewritingOperatorAsSpaceship:
        return "RewritingOperatorAsSpaceship";
      case CodeSynthesisContext::Memoization:
        return "Memoization";
      case CodeSynthesisContext::ConstraintsCheck:
        return "ConstraintsCheck";
      case CodeSynthesisContext::ConstraintSubstitution:
        return "ConstraintSubstitution";
      case CodeSynthesisContext::ConstraintNormalization:
        return "ConstraintNormalization";
      case CodeSynthesisContext::ParameterMappingSubstitution:
        return "ParameterMappingSubstitution";
      case CodeSynthesisContext::RequirementInstantiation:
        return "RequirementInstantiation";
      case CodeSynthesisContext::NestedRequirementConstraintsCheck:
        return "NestedRequirementConstraintsCheck";
      }
      return "";
    }
  
    template <bool BeginInstantiation>
    static void displayTemplightEntry(llvm::raw_ostream &Out, const Sema &TheSema,
                                      const CodeSynthesisContext &Inst) {
      std::string YAML;
      {
        llvm::raw_string_ostream OS(YAML);
        llvm::yaml::Output YO(OS);
        TemplightEntry Entry =
            getTemplightEntry<BeginInstantiation>(TheSema, Inst);
        llvm::yaml::EmptyContext Context;
        llvm::yaml::yamlize(YO, Entry, true, Context);
      }
      Out << "---" << YAML << "\n";
    }
  
    template <bool BeginInstantiation>
    static TemplightEntry getTemplightEntry(const Sema &TheSema,
                                            const CodeSynthesisContext &Inst) {
      TemplightEntry Entry;
      Entry.Kind = toString(Inst.Kind);
      Entry.Event = BeginInstantiation ? "Begin" : "End";
      if (auto *NamedTemplate = dyn_cast_or_null<NamedDecl>(Inst.Entity)) {
        llvm::raw_string_ostream OS(Entry.Name);
        NamedTemplate->getNameForDiagnostic(OS, TheSema.getLangOpts(), true);
        const PresumedLoc DefLoc =
          TheSema.getSourceManager().getPresumedLoc(Inst.Entity->getLocation());
        if(!DefLoc.isInvalid())
          Entry.DefinitionLocation = std::string(DefLoc.getFilename()) + ":" +
                                     std::to_string(DefLoc.getLine()) + ":" +
                                     std::to_string(DefLoc.getColumn());
      }
      const PresumedLoc PoiLoc =
          TheSema.getSourceManager().getPresumedLoc(Inst.PointOfInstantiation);
      if (!PoiLoc.isInvalid()) {
        Entry.PointOfInstantiation = std::string(PoiLoc.getFilename()) + ":" +
                                     std::to_string(PoiLoc.getLine()) + ":" +
                                     std::to_string(PoiLoc.getColumn());
      }
      return Entry;
    }
  };
  } // namespace
  
  std::unique_ptr<ASTConsumer>
  TemplightDumpAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
    return std::make_unique<ASTConsumer>();
  }
  
  void TemplightDumpAction::ExecuteAction() {
    CompilerInstance &CI = getCompilerInstance();
  
    // This part is normally done by ASTFrontEndAction, but needs to happen
    // before Templight observers can be created
    // FIXME: Move the truncation aspect of this into Sema, we delayed this till
    // here so the source manager would be initialized.
    EnsureSemaIsCreated(CI, *this);
  
    CI.getSema().TemplateInstCallbacks.push_back(
        std::make_unique<DefaultTemplateInstCallback>());
    ASTFrontendAction::ExecuteAction();
  }
  
  namespace {
    /// AST reader listener that dumps module information for a module
    /// file.
    class DumpModuleInfoListener : public ASTReaderListener {
      llvm::raw_ostream &Out;
  
    public:
      DumpModuleInfoListener(llvm::raw_ostream &Out) : Out(Out) { }
  
  #define DUMP_BOOLEAN(Value, Text)                       \
      Out.indent(4) << Text << ": " << (Value? "Yes" : "No") << "\n"
  
      bool ReadFullVersionInformation(StringRef FullVersion) override {
        Out.indent(2)
          << "Generated by "
          << (FullVersion == getClangFullRepositoryVersion()? "this"
                                                            : "a different")
          << " Clang: " << FullVersion << "\n";
        return ASTReaderListener::ReadFullVersionInformation(FullVersion);
      }
  
      void ReadModuleName(StringRef ModuleName) override {
        Out.indent(2) << "Module name: " << ModuleName << "\n";
      }
      void ReadModuleMapFile(StringRef ModuleMapPath) override {
        Out.indent(2) << "Module map file: " << ModuleMapPath << "\n";
      }
  
      bool ReadLanguageOptions(const LangOptions &LangOpts, bool Complain,
                               bool AllowCompatibleDifferences) override {
        Out.indent(2) << "Language options:\n";
  #define LANGOPT(Name, Bits, Default, Description) \
        DUMP_BOOLEAN(LangOpts.Name, Description);
  #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
        Out.indent(4) << Description << ": "                   \
                      << static_cast<unsigned>(LangOpts.get##Name()) << "\n";
  #define VALUE_LANGOPT(Name, Bits, Default, Description) \
        Out.indent(4) << Description << ": " << LangOpts.Name << "\n";
  #define BENIGN_LANGOPT(Name, Bits, Default, Description)
  #define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
  #include "clang/Basic/LangOptions.def"
  
        if (!LangOpts.ModuleFeatures.empty()) {
          Out.indent(4) << "Module features:\n";
          for (StringRef Feature : LangOpts.ModuleFeatures)
            Out.indent(6) << Feature << "\n";
        }
  
        return false;
      }
  
      bool ReadTargetOptions(const TargetOptions &TargetOpts, bool Complain,
                             bool AllowCompatibleDifferences) override {
        Out.indent(2) << "Target options:\n";
        Out.indent(4) << "  Triple: " << TargetOpts.Triple << "\n";
        Out.indent(4) << "  CPU: " << TargetOpts.CPU << "\n";
        Out.indent(4) << "  ABI: " << TargetOpts.ABI << "\n";
  
        if (!TargetOpts.FeaturesAsWritten.empty()) {
          Out.indent(4) << "Target features:\n";
          for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size();
               I != N; ++I) {
            Out.indent(6) << TargetOpts.FeaturesAsWritten[I] << "\n";
          }
        }
  
        return false;
      }
  
      bool ReadDiagnosticOptions(IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts,
                                 bool Complain) override {
        Out.indent(2) << "Diagnostic options:\n";
  #define DIAGOPT(Name, Bits, Default) DUMP_BOOLEAN(DiagOpts->Name, #Name);
  #define ENUM_DIAGOPT(Name, Type, Bits, Default) \
        Out.indent(4) << #Name << ": " << DiagOpts->get##Name() << "\n";
  #define VALUE_DIAGOPT(Name, Bits, Default) \
        Out.indent(4) << #Name << ": " << DiagOpts->Name << "\n";
  #include "clang/Basic/DiagnosticOptions.def"
  
        Out.indent(4) << "Diagnostic flags:\n";
        for (const std::string &Warning : DiagOpts->Warnings)
          Out.indent(6) << "-W" << Warning << "\n";
        for (const std::string &Remark : DiagOpts->Remarks)
          Out.indent(6) << "-R" << Remark << "\n";
  
        return false;
      }
  
      bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
                                   StringRef SpecificModuleCachePath,
                                   bool Complain) override {
        Out.indent(2) << "Header search options:\n";
        Out.indent(4) << "System root [-isysroot=]: '" << HSOpts.Sysroot << "'\n";
        Out.indent(4) << "Resource dir [ -resource-dir=]: '" << HSOpts.ResourceDir << "'\n";
        Out.indent(4) << "Module Cache: '" << SpecificModuleCachePath << "'\n";
        DUMP_BOOLEAN(HSOpts.UseBuiltinIncludes,
                     "Use builtin include directories [-nobuiltininc]");
        DUMP_BOOLEAN(HSOpts.UseStandardSystemIncludes,
                     "Use standard system include directories [-nostdinc]");
        DUMP_BOOLEAN(HSOpts.UseStandardCXXIncludes,
                     "Use standard C++ include directories [-nostdinc++]");
        DUMP_BOOLEAN(HSOpts.UseLibcxx,
                     "Use libc++ (rather than libstdc++) [-stdlib=]");
        return false;
      }
  
      bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
                                   bool Complain,
                                   std::string &SuggestedPredefines) override {
        Out.indent(2) << "Preprocessor options:\n";
        DUMP_BOOLEAN(PPOpts.UsePredefines,
                     "Uses compiler/target-specific predefines [-undef]");
        DUMP_BOOLEAN(PPOpts.DetailedRecord,
                     "Uses detailed preprocessing record (for indexing)");
  
        if (!PPOpts.Macros.empty()) {
          Out.indent(4) << "Predefined macros:\n";
        }
  
        for (std::vector<std::pair<std::string, bool/*isUndef*/> >::const_iterator
               I = PPOpts.Macros.begin(), IEnd = PPOpts.Macros.end();
             I != IEnd; ++I) {
          Out.indent(6);
          if (I->second)
            Out << "-U";
          else
            Out << "-D";
          Out << I->first << "\n";
        }
        return false;
      }
  
      /// Indicates that a particular module file extension has been read.
      void readModuleFileExtension(
             const ModuleFileExtensionMetadata &Metadata) override {
        Out.indent(2) << "Module file extension '"
                      << Metadata.BlockName << "' " << Metadata.MajorVersion
                      << "." << Metadata.MinorVersion;
        if (!Metadata.UserInfo.empty()) {
          Out << ": ";
          Out.write_escaped(Metadata.UserInfo);
        }
  
        Out << "\n";
      }
  
      /// Tells the \c ASTReaderListener that we want to receive the
      /// input files of the AST file via \c visitInputFile.
      bool needsInputFileVisitation() override { return true; }
  
      /// Tells the \c ASTReaderListener that we want to receive the
      /// input files of the AST file via \c visitInputFile.
      bool needsSystemInputFileVisitation() override { return true; }
  
      /// Indicates that the AST file contains particular input file.
      ///
      /// \returns true to continue receiving the next input file, false to stop.
      bool visitInputFile(StringRef Filename, bool isSystem,
                          bool isOverridden, bool isExplicitModule) override {
  
        Out.indent(2) << "Input file: " << Filename;
  
        if (isSystem || isOverridden || isExplicitModule) {
          Out << " [";
          if (isSystem) {
            Out << "System";
            if (isOverridden || isExplicitModule)
              Out << ", ";
          }
          if (isOverridden) {
            Out << "Overridden";
            if (isExplicitModule)
              Out << ", ";
          }
          if (isExplicitModule)
            Out << "ExplicitModule";
  
          Out << "]";
        }
  
        Out << "\n";
  
        return true;
      }
  
      /// Returns true if this \c ASTReaderListener wants to receive the
      /// imports of the AST file via \c visitImport, false otherwise.
      bool needsImportVisitation() const override { return true; }
  
      /// If needsImportVisitation returns \c true, this is called for each
      /// AST file imported by this AST file.
      void visitImport(StringRef ModuleName, StringRef Filename) override {
        Out.indent(2) << "Imports module '" << ModuleName
                      << "': " << Filename.str() << "\n";
      }
  #undef DUMP_BOOLEAN
    };
  }
  
  bool DumpModuleInfoAction::BeginInvocation(CompilerInstance &CI) {
    // The Object file reader also supports raw ast files and there is no point in
    // being strict about the module file format in -module-file-info mode.
    CI.getHeaderSearchOpts().ModuleFormat = "obj";
    return true;
  }
  
  void DumpModuleInfoAction::ExecuteAction() {
    // Set up the output file.
    std::unique_ptr<llvm::raw_fd_ostream> OutFile;
    StringRef OutputFileName = getCompilerInstance().getFrontendOpts().OutputFile;
    if (!OutputFileName.empty() && OutputFileName != "-") {
      std::error_code EC;
      OutFile.reset(new llvm::raw_fd_ostream(OutputFileName.str(), EC,
                                             llvm::sys::fs::OF_Text));
    }
    llvm::raw_ostream &Out = OutFile.get()? *OutFile.get() : llvm::outs();
  
    Out << "Information for module file '" << getCurrentFile() << "':\n";
    auto &FileMgr = getCompilerInstance().getFileManager();
    auto Buffer = FileMgr.getBufferForFile(getCurrentFile());
    StringRef Magic = (*Buffer)->getMemBufferRef().getBuffer();
    bool IsRaw = (Magic.size() >= 4 && Magic[0] == 'C' && Magic[1] == 'P' &&
                  Magic[2] == 'C' && Magic[3] == 'H');
    Out << "  Module format: " << (IsRaw ? "raw" : "obj") << "\n";
  
    Preprocessor &PP = getCompilerInstance().getPreprocessor();
    DumpModuleInfoListener Listener(Out);
    HeaderSearchOptions &HSOpts =
        PP.getHeaderSearchInfo().getHeaderSearchOpts();
    ASTReader::readASTFileControlBlock(
        getCurrentFile(), FileMgr, getCompilerInstance().getPCHContainerReader(),
        /*FindModuleFileExtensions=*/true, Listener,
        HSOpts.ModulesValidateDiagnosticOptions);
  }
  
  //===----------------------------------------------------------------------===//
  // Preprocessor Actions
  //===----------------------------------------------------------------------===//
  
  void DumpRawTokensAction::ExecuteAction() {
    Preprocessor &PP = getCompilerInstance().getPreprocessor();
    SourceManager &SM = PP.getSourceManager();
  
    // Start lexing the specified input file.
    const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
    Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
    RawLex.SetKeepWhitespaceMode(true);
  
    Token RawTok;
    RawLex.LexFromRawLexer(RawTok);
    while (RawTok.isNot(tok::eof)) {
      PP.DumpToken(RawTok, true);
      llvm::errs() << "\n";
      RawLex.LexFromRawLexer(RawTok);
    }
  }
  
  void DumpTokensAction::ExecuteAction() {
    Preprocessor &PP = getCompilerInstance().getPreprocessor();
    // Start preprocessing the specified input file.
    Token Tok;
    PP.EnterMainSourceFile();
    do {
      PP.Lex(Tok);
      PP.DumpToken(Tok, true);
      llvm::errs() << "\n";
    } while (Tok.isNot(tok::eof));
  }
  
  void PreprocessOnlyAction::ExecuteAction() {
    Preprocessor &PP = getCompilerInstance().getPreprocessor();
  
    // Ignore unknown pragmas.
    PP.IgnorePragmas();
  
    Token Tok;
    // Start parsing the specified input file.
    PP.EnterMainSourceFile();
    do {
      PP.Lex(Tok);
    } while (Tok.isNot(tok::eof));
  }
  
  void PrintPreprocessedAction::ExecuteAction() {
    CompilerInstance &CI = getCompilerInstance();
    // Output file may need to be set to 'Binary', to avoid converting Unix style
    // line feeds (<LF>) to Microsoft style line feeds (<CR><LF>).
    //
    // Look to see what type of line endings the file uses. If there's a
    // CRLF, then we won't open the file up in binary mode. If there is
    // just an LF or CR, then we will open the file up in binary mode.
    // In this fashion, the output format should match the input format, unless
    // the input format has inconsistent line endings.
    //
    // This should be a relatively fast operation since most files won't have
    // all of their source code on a single line. However, that is still a
    // concern, so if we scan for too long, we'll just assume the file should
    // be opened in binary mode.
    bool BinaryMode = true;
    bool InvalidFile = false;
    const SourceManager& SM = CI.getSourceManager();
    const llvm::MemoryBuffer *Buffer = SM.getBuffer(SM.getMainFileID(),
                                                       &InvalidFile);
    if (!InvalidFile) {
      const char *cur = Buffer->getBufferStart();
      const char *end = Buffer->getBufferEnd();
      const char *next = (cur != end) ? cur + 1 : end;
  
      // Limit ourselves to only scanning 256 characters into the source
      // file.  This is mostly a sanity check in case the file has no
      // newlines whatsoever.
      if (end - cur > 256) end = cur + 256;
  
      while (next < end) {
        if (*cur == 0x0D) {  // CR
          if (*next == 0x0A)  // CRLF
            BinaryMode = false;
  
          break;
        } else if (*cur == 0x0A)  // LF
          break;
  
        ++cur;
        ++next;
      }
    }
  
    std::unique_ptr<raw_ostream> OS =
        CI.createDefaultOutputFile(BinaryMode, getCurrentFileOrBufferName());
    if (!OS) return;
  
    // If we're preprocessing a module map, start by dumping the contents of the
    // module itself before switching to the input buffer.
    auto &Input = getCurrentInput();
    if (Input.getKind().getFormat() == InputKind::ModuleMap) {
      if (Input.isFile()) {
        (*OS) << "# 1 \"";
        OS->write_escaped(Input.getFile());
        (*OS) << "\"\n";
      }
      getCurrentModule()->print(*OS);
      (*OS) << "#pragma clang module contents\n";
    }
  
    DoPrintPreprocessedInput(CI.getPreprocessor(), OS.get(),
                             CI.getPreprocessorOutputOpts());
  }
  
  void PrintPreambleAction::ExecuteAction() {
    switch (getCurrentFileKind().getLanguage()) {
    case Language::C:
    case Language::CXX:
    case Language::ObjC:
    case Language::ObjCXX:
    case Language::OpenCL:
    case Language::CUDA:
    case Language::HIP:
      break;
  
    case Language::Unknown:
    case Language::Asm:
    case Language::LLVM_IR:
    case Language::RenderScript:
      // We can't do anything with these.
      return;
    }
  
    // We don't expect to find any #include directives in a preprocessed input.
    if (getCurrentFileKind().isPreprocessed())
      return;
  
    CompilerInstance &CI = getCompilerInstance();
    auto Buffer = CI.getFileManager().getBufferForFile(getCurrentFile());
    if (Buffer) {
      unsigned Preamble =
          Lexer::ComputePreamble((*Buffer)->getBuffer(), CI.getLangOpts()).Size;
      llvm::outs().write((*Buffer)->getBufferStart(), Preamble);
    }
  }
  
  void DumpCompilerOptionsAction::ExecuteAction() {
    CompilerInstance &CI = getCompilerInstance();
    std::unique_ptr<raw_ostream> OSP =
        CI.createDefaultOutputFile(false, getCurrentFile());
    if (!OSP)
      return;
  
    raw_ostream &OS = *OSP;
    const Preprocessor &PP = CI.getPreprocessor();
    const LangOptions &LangOpts = PP.getLangOpts();
  
    // FIXME: Rather than manually format the JSON (which is awkward due to
    // needing to remove trailing commas), this should make use of a JSON library.
    // FIXME: Instead of printing enums as an integral value and specifying the
    // type as a separate field, use introspection to print the enumerator.
  
    OS << "{\n";
    OS << "\n\"features\" : [\n";
    {
      llvm::SmallString<128> Str;
  #define FEATURE(Name, Predicate)                                               \
    ("\t{\"" #Name "\" : " + llvm::Twine(Predicate ? "true" : "false") + "},\n") \
        .toVector(Str);
  #include "clang/Basic/Features.def"
  #undef FEATURE
      // Remove the newline and comma from the last entry to ensure this remains
      // valid JSON.
      OS << Str.substr(0, Str.size() - 2);
    }
    OS << "\n],\n";
  
    OS << "\n\"extensions\" : [\n";
    {
      llvm::SmallString<128> Str;
  #define EXTENSION(Name, Predicate)                                             \
    ("\t{\"" #Name "\" : " + llvm::Twine(Predicate ? "true" : "false") + "},\n") \
        .toVector(Str);
  #include "clang/Basic/Features.def"
  #undef EXTENSION
      // Remove the newline and comma from the last entry to ensure this remains
      // valid JSON.
      OS << Str.substr(0, Str.size() - 2);
    }
    OS << "\n]\n";
  
    OS << "}";
  }
  
  void PrintDependencyDirectivesSourceMinimizerAction::ExecuteAction() {
    CompilerInstance &CI = getCompilerInstance();
    SourceManager &SM = CI.getPreprocessor().getSourceManager();
    const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
  
    llvm::SmallString<1024> Output;
    llvm::SmallVector<minimize_source_to_dependency_directives::Token, 32> Toks;
    if (minimizeSourceToDependencyDirectives(
            FromFile->getBuffer(), Output, Toks, &CI.getDiagnostics(),
            SM.getLocForStartOfFile(SM.getMainFileID()))) {
      assert(CI.getDiagnostics().hasErrorOccurred() &&
             "no errors reported for failure");
  
      // Preprocess the source when verifying the diagnostics to capture the
      // 'expected' comments.
      if (CI.getDiagnosticOpts().VerifyDiagnostics) {
        // Make sure we don't emit new diagnostics!
        CI.getDiagnostics().setSuppressAllDiagnostics(true);
        Preprocessor &PP = getCompilerInstance().getPreprocessor();
        PP.EnterMainSourceFile();
        Token Tok;
        do {
          PP.Lex(Tok);
        } while (Tok.isNot(tok::eof));
      }
      return;
    }
    llvm::outs() << Output;
  }
  