text: //===- CompilerInvocation.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 "flang/Frontend/CompilerInvocation.h"
  #include "flang/Common/Fortran-features.h"
  #include "flang/Frontend/PreprocessorOptions.h"
  #include "flang/Semantics/semantics.h"
  #include "flang/Version.inc"
  #include "clang/Basic/AllDiagnostics.h"
  #include "clang/Basic/DiagnosticDriver.h"
  #include "clang/Basic/DiagnosticOptions.h"
  #include "clang/Driver/DriverDiagnostic.h"
  #include "clang/Driver/Options.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/ADT/StringSwitch.h"
  #include "llvm/Option/Arg.h"
  #include "llvm/Option/ArgList.h"
  #include "llvm/Option/OptTable.h"
  #include "llvm/Support/Process.h"
  #include "llvm/Support/raw_ostream.h"
  #include <memory>
  
  using namespace Fortran::frontend;
  
  //===----------------------------------------------------------------------===//
  // Initialization.
  //===----------------------------------------------------------------------===//
  CompilerInvocationBase::CompilerInvocationBase()
      : diagnosticOpts_(new clang::DiagnosticOptions()),
        preprocessorOpts_(new PreprocessorOptions()) {}
  
  CompilerInvocationBase::CompilerInvocationBase(const CompilerInvocationBase &x)
      : diagnosticOpts_(new clang::DiagnosticOptions(x.GetDiagnosticOpts())),
        preprocessorOpts_(new PreprocessorOptions(x.preprocessorOpts())) {}
  
  CompilerInvocationBase::~CompilerInvocationBase() = default;
  
  //===----------------------------------------------------------------------===//
  // Deserialization (from args)
  //===----------------------------------------------------------------------===//
  static bool parseShowColorsArgs(
      const llvm::opt::ArgList &args, bool defaultColor) {
    // Color diagnostics default to auto ("on" if terminal supports) in the driver
    // but default to off in cc1, needing an explicit OPT_fdiagnostics_color.
    // Support both clang's -f[no-]color-diagnostics and gcc's
    // -f[no-]diagnostics-colors[=never|always|auto].
    enum {
      Colors_On,
      Colors_Off,
      Colors_Auto
    } ShowColors = defaultColor ? Colors_Auto : Colors_Off;
  
    for (auto *a : args) {
      const llvm::opt::Option &O = a->getOption();
      if (O.matches(clang::driver::options::OPT_fcolor_diagnostics) ||
          O.matches(clang::driver::options::OPT_fdiagnostics_color)) {
        ShowColors = Colors_On;
      } else if (O.matches(clang::driver::options::OPT_fno_color_diagnostics) ||
          O.matches(clang::driver::options::OPT_fno_diagnostics_color)) {
        ShowColors = Colors_Off;
      } else if (O.matches(clang::driver::options::OPT_fdiagnostics_color_EQ)) {
        llvm::StringRef value(a->getValue());
        if (value == "always")
          ShowColors = Colors_On;
        else if (value == "never")
          ShowColors = Colors_Off;
        else if (value == "auto")
          ShowColors = Colors_Auto;
      }
    }
  
    return ShowColors == Colors_On ||
        (ShowColors == Colors_Auto && llvm::sys::Process::StandardErrHasColors());
  }
  
  bool Fortran::frontend::ParseDiagnosticArgs(clang::DiagnosticOptions &opts,
      llvm::opt::ArgList &args, bool defaultDiagColor) {
    opts.ShowColors = parseShowColorsArgs(args, defaultDiagColor);
  
    return true;
  }
  
  // Tweak the frontend configuration based on the frontend action
  static void setUpFrontendBasedOnAction(FrontendOptions &opts) {
    assert(opts.programAction_ != Fortran::frontend::InvalidAction &&
        "Fortran frontend action not set!");
  
    if (opts.programAction_ == DebugDumpParsingLog)
      opts.instrumentedParse_ = true;
  }
  
  static InputKind ParseFrontendArgs(FrontendOptions &opts,
      llvm::opt::ArgList &args, clang::DiagnosticsEngine &diags) {
  
    // By default the frontend driver creates a ParseSyntaxOnly action.
    opts.programAction_ = ParseSyntaxOnly;
  
    // Identify the action (i.e. opts.ProgramAction)
    if (const llvm::opt::Arg *a =
            args.getLastArg(clang::driver::options::OPT_Action_Group)) {
      switch (a->getOption().getID()) {
      default: {
        llvm_unreachable("Invalid option in group!");
      }
      case clang::driver::options::OPT_test_io:
        opts.programAction_ = InputOutputTest;
        break;
      case clang::driver::options::OPT_E:
        opts.programAction_ = PrintPreprocessedInput;
        break;
      case clang::driver::options::OPT_fsyntax_only:
        opts.programAction_ = ParseSyntaxOnly;
        break;
      case clang::driver::options::OPT_emit_obj:
        opts.programAction_ = EmitObj;
        break;
      case clang::driver::options::OPT_fdebug_unparse:
        opts.programAction_ = DebugUnparse;
        break;
      case clang::driver::options::OPT_fdebug_unparse_with_symbols:
        opts.programAction_ = DebugUnparseWithSymbols;
        break;
      case clang::driver::options::OPT_fdebug_dump_symbols:
        opts.programAction_ = DebugDumpSymbols;
        break;
      case clang::driver::options::OPT_fdebug_dump_parse_tree:
        opts.programAction_ = DebugDumpParseTree;
        break;
      case clang::driver::options::OPT_fdebug_dump_provenance:
        opts.programAction_ = DebugDumpProvenance;
        break;
      case clang::driver::options::OPT_fdebug_dump_parsing_log:
        opts.programAction_ = DebugDumpParsingLog;
        break;
      case clang::driver::options::OPT_fdebug_measure_parse_tree:
        opts.programAction_ = DebugMeasureParseTree;
        break;
      case clang::driver::options::OPT_fdebug_pre_fir_tree:
        opts.programAction_ = DebugPreFIRTree;
        break;
      case clang::driver::options::OPT_fget_symbols_sources:
        opts.programAction_ = GetSymbolsSources;
        break;
  
        // TODO:
        // case calng::driver::options::OPT_emit_llvm:
        // case clang::driver::options::OPT_emit_llvm_only:
        // case clang::driver::options::OPT_emit_codegen_only:
        // case clang::driver::options::OPT_emit_module:
        // (...)
      }
    }
  
    opts.outputFile_ = args.getLastArgValue(clang::driver::options::OPT_o);
    opts.showHelp_ = args.hasArg(clang::driver::options::OPT_help);
    opts.showVersion_ = args.hasArg(clang::driver::options::OPT_version);
  
    // Get the input kind (from the value passed via `-x`)
    InputKind dashX(Language::Unknown);
    if (const llvm::opt::Arg *a =
            args.getLastArg(clang::driver::options::OPT_x)) {
      llvm::StringRef XValue = a->getValue();
      // Principal languages.
      dashX = llvm::StringSwitch<InputKind>(XValue)
                  .Case("f90", Language::Fortran)
                  .Default(Language::Unknown);
  
      // Some special cases cannot be combined with suffixes.
      if (dashX.IsUnknown())
        dashX = llvm::StringSwitch<InputKind>(XValue)
                    .Case("ir", Language::LLVM_IR)
                    .Default(Language::Unknown);
  
      if (dashX.IsUnknown())
        diags.Report(clang::diag::err_drv_invalid_value)
            << a->getAsString(args) << a->getValue();
    }
  
    // Collect the input files and save them in our instance of FrontendOptions.
    std::vector<std::string> inputs =
        args.getAllArgValues(clang::driver::options::OPT_INPUT);
    opts.inputs_.clear();
    if (inputs.empty())
      // '-' is the default input if none is given.
      inputs.push_back("-");
    for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
      InputKind ik = dashX;
      if (ik.IsUnknown()) {
        ik = FrontendOptions::GetInputKindForExtension(
            llvm::StringRef(inputs[i]).rsplit('.').second);
        if (ik.IsUnknown())
          ik = Language::Unknown;
        if (i == 0)
          dashX = ik;
      }
  
      opts.inputs_.emplace_back(std::move(inputs[i]), ik);
    }
  
    // Set fortranForm_ based on options -ffree-form and -ffixed-form.
    if (const auto *arg = args.getLastArg(clang::driver::options::OPT_ffixed_form,
            clang::driver::options::OPT_ffree_form)) {
      opts.fortranForm_ =
          arg->getOption().matches(clang::driver::options::OPT_ffixed_form)
          ? FortranForm::FixedForm
          : FortranForm::FreeForm;
    }
  
    // Set fixedFormColumns_ based on -ffixed-line-length=<value>
    if (const auto *arg =
            args.getLastArg(clang::driver::options::OPT_ffixed_line_length_EQ)) {
      llvm::StringRef argValue = llvm::StringRef(arg->getValue());
      std::int64_t columns = -1;
      if (argValue == "none") {
        columns = 0;
      } else if (argValue.getAsInteger(/*Radix=*/10, columns)) {
        columns = -1;
      }
      if (columns < 0) {
        diags.Report(clang::diag::err_drv_invalid_value_with_suggestion)
            << arg->getOption().getName() << arg->getValue()
            << "value must be 'none' or a non-negative integer";
      } else if (columns == 0) {
        opts.fixedFormColumns_ = 1000000;
      } else if (columns < 7) {
        diags.Report(clang::diag::err_drv_invalid_value_with_suggestion)
            << arg->getOption().getName() << arg->getValue()
            << "value must be at least seven";
      } else {
        opts.fixedFormColumns_ = columns;
      }
    }
  
    if (const llvm::opt::Arg *arg =
            args.getLastArg(clang::driver::options::OPT_fimplicit_none,
                clang::driver::options::OPT_fno_implicit_none)) {
      opts.features_.Enable(
          Fortran::common::LanguageFeature::ImplicitNoneTypeAlways,
          arg->getOption().matches(clang::driver::options::OPT_fimplicit_none));
    }
    if (const llvm::opt::Arg *arg =
            args.getLastArg(clang::driver::options::OPT_fbackslash,
                clang::driver::options::OPT_fno_backslash)) {
      opts.features_.Enable(Fortran::common::LanguageFeature::BackslashEscapes,
          arg->getOption().matches(clang::driver::options::OPT_fbackslash));
    }
    if (const llvm::opt::Arg *arg =
            args.getLastArg(clang::driver::options::OPT_flogical_abbreviations,
                clang::driver::options::OPT_fno_logical_abbreviations)) {
      opts.features_.Enable(
          Fortran::common::LanguageFeature::LogicalAbbreviations,
          arg->getOption().matches(
              clang::driver::options::OPT_flogical_abbreviations));
    }
    if (const llvm::opt::Arg *arg =
            args.getLastArg(clang::driver::options::OPT_fxor_operator,
                clang::driver::options::OPT_fno_xor_operator)) {
      opts.features_.Enable(Fortran::common::LanguageFeature::XOROperator,
          arg->getOption().matches(clang::driver::options::OPT_fxor_operator));
    }
    if (args.hasArg(
            clang::driver::options::OPT_falternative_parameter_statement)) {
      opts.features_.Enable(Fortran::common::LanguageFeature::OldStyleParameter);
    }
    if (const llvm::opt::Arg *arg =
            args.getLastArg(clang::driver::options::OPT_finput_charset_EQ)) {
      llvm::StringRef argValue = arg->getValue();
      if (argValue == "utf-8") {
        opts.encoding_ = Fortran::parser::Encoding::UTF_8;
      } else if (argValue == "latin-1") {
        opts.encoding_ = Fortran::parser::Encoding::LATIN_1;
      } else {
        diags.Report(clang::diag::err_drv_invalid_value)
            << arg->getAsString(args) << argValue;
      }
    }
  
    setUpFrontendBasedOnAction(opts);
  
    return dashX;
  }
  
  /// Parses all preprocessor input arguments and populates the preprocessor
  /// options accordingly.
  ///
  /// \param [in] opts The preprocessor options instance
  /// \param [out] args The list of input arguments
  static void parsePreprocessorArgs(
      Fortran::frontend::PreprocessorOptions &opts, llvm::opt::ArgList &args) {
    // Add macros from the command line.
    for (const auto *currentArg : args.filtered(
             clang::driver::options::OPT_D, clang::driver::options::OPT_U)) {
      if (currentArg->getOption().matches(clang::driver::options::OPT_D)) {
        opts.addMacroDef(currentArg->getValue());
      } else {
        opts.addMacroUndef(currentArg->getValue());
      }
    }
  
    // Add the ordered list of -I's.
    for (const auto *currentArg : args.filtered(clang::driver::options::OPT_I))
      opts.searchDirectoriesFromDashI.emplace_back(currentArg->getValue());
  }
  
  /// Parses all semantic related arguments and populates the variables
  /// options accordingly.
  static void parseSemaArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
      clang::DiagnosticsEngine &diags) {
  
    // -J/module-dir option
    auto moduleDirList =
        args.getAllArgValues(clang::driver::options::OPT_module_dir);
    // User can only specify -J/-module-dir once
    // https://gcc.gnu.org/onlinedocs/gfortran/Directory-Options.html
    if (moduleDirList.size() > 1) {
      const unsigned diagID =
          diags.getCustomDiagID(clang::DiagnosticsEngine::Error,
              "Only one '-module-dir/-J' option allowed");
      diags.Report(diagID);
    }
    if (moduleDirList.size() == 1)
      res.SetModuleDir(moduleDirList[0]);
  
    // -fdebug-module-writer option
    if (args.hasArg(clang::driver::options::OPT_fdebug_module_writer)) {
      res.SetDebugModuleDir(true);
    }
  }
  
  /// Parses all Dialect related arguments and populates the variables
  /// options accordingly.
  static void parseDialectArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
      clang::DiagnosticsEngine &diags) {
  
    // -fdefault* family
    if (args.hasArg(clang::driver::options::OPT_fdefault_real_8)) {
      res.defaultKinds().set_defaultRealKind(8);
      res.defaultKinds().set_doublePrecisionKind(16);
    }
    if (args.hasArg(clang::driver::options::OPT_fdefault_integer_8)) {
      res.defaultKinds().set_defaultIntegerKind(8);
      res.defaultKinds().set_subscriptIntegerKind(8);
      res.defaultKinds().set_sizeIntegerKind(8);
    }
    if (args.hasArg(clang::driver::options::OPT_fdefault_double_8)) {
      if (!args.hasArg(clang::driver::options::OPT_fdefault_real_8)) {
        // -fdefault-double-8 has to be used with -fdefault-real-8
        // to be compatible with gfortran
        const unsigned diagID =
            diags.getCustomDiagID(clang::DiagnosticsEngine::Error,
                "Use of `-fdefault-double-8` requires `-fdefault-real-8`");
        diags.Report(diagID);
      }
      // https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html
      res.defaultKinds().set_doublePrecisionKind(8);
    }
    if (args.hasArg(clang::driver::options::OPT_flarge_sizes))
      res.defaultKinds().set_sizeIntegerKind(8);
  
    // -fopenmp and -fopenacc
    if (args.hasArg(clang::driver::options::OPT_fopenacc)) {
      res.frontendOpts().features_.Enable(
          Fortran::common::LanguageFeature::OpenACC);
    }
    if (args.hasArg(clang::driver::options::OPT_fopenmp)) {
      res.frontendOpts().features_.Enable(
          Fortran::common::LanguageFeature::OpenMP);
    }
    return;
  }
  
  bool CompilerInvocation::CreateFromArgs(CompilerInvocation &res,
      llvm::ArrayRef<const char *> commandLineArgs,
      clang::DiagnosticsEngine &diags) {
  
    bool success = true;
  
    // Parse the arguments
    const llvm::opt::OptTable &opts = clang::driver::getDriverOptTable();
    const unsigned includedFlagsBitmask = clang::driver::options::FC1Option;
    unsigned missingArgIndex, missingArgCount;
    llvm::opt::InputArgList args = opts.ParseArgs(
        commandLineArgs, missingArgIndex, missingArgCount, includedFlagsBitmask);
  
    // Issue errors on unknown arguments
    for (const auto *a : args.filtered(clang::driver::options::OPT_UNKNOWN)) {
      auto argString = a->getAsString(args);
      std::string nearest;
      if (opts.findNearest(argString, nearest, includedFlagsBitmask) > 1)
        diags.Report(clang::diag::err_drv_unknown_argument) << argString;
      else
        diags.Report(clang::diag::err_drv_unknown_argument_with_suggestion)
            << argString << nearest;
      success = false;
    }
  
    // Parse the frontend args
    ParseFrontendArgs(res.frontendOpts(), args, diags);
    // Parse the preprocessor args
    parsePreprocessorArgs(res.preprocessorOpts(), args);
    // Parse semantic args
    parseSemaArgs(res, args, diags);
    // Parse dialect arguments
    parseDialectArgs(res, args, diags);
  
    return success;
  }
  
  /// Collect the macro definitions provided by the given preprocessor
  /// options into the parser options.
  ///
  /// \param [in] ppOpts The preprocessor options
  /// \param [out] opts The fortran options
  static void collectMacroDefinitions(
      const PreprocessorOptions &ppOpts, Fortran::parser::Options &opts) {
    for (unsigned i = 0, n = ppOpts.macros.size(); i != n; ++i) {
      llvm::StringRef macro = ppOpts.macros[i].first;
      bool isUndef = ppOpts.macros[i].second;
  
      std::pair<llvm::StringRef, llvm::StringRef> macroPair = macro.split('=');
      llvm::StringRef macroName = macroPair.first;
      llvm::StringRef macroBody = macroPair.second;
  
      // For an #undef'd macro, we only care about the name.
      if (isUndef) {
        opts.predefinitions.emplace_back(
            macroName.str(), std::optional<std::string>{});
        continue;
      }
  
      // For a #define'd macro, figure out the actual definition.
      if (macroName.size() == macro.size())
        macroBody = "1";
      else {
        // Note: GCC drops anything following an end-of-line character.
        llvm::StringRef::size_type End = macroBody.find_first_of("\n\r");
        macroBody = macroBody.substr(0, End);
      }
      opts.predefinitions.emplace_back(
          macroName, std::optional<std::string>(macroBody.str()));
    }
  }
  
  void CompilerInvocation::SetDefaultFortranOpts() {
    auto &fortranOptions = fortranOpts();
  
    // These defaults are based on the defaults in f18/f18.cpp.
    std::vector<std::string> searchDirectories{"."s};
    fortranOptions.searchDirectories = searchDirectories;
    fortranOptions.isFixedForm = false;
  }
  
  // TODO: When expanding this method, consider creating a dedicated API for
  // this. Also at some point we will need to differentiate between different
  // targets and add dedicated predefines for each.
  void CompilerInvocation::setDefaultPredefinitions() {
    auto &fortranOptions = fortranOpts();
    const auto &frontendOptions = frontendOpts();
  
    // Populate the macro list with version numbers and other predefinitions.
    fortranOptions.predefinitions.emplace_back("__flang__", "1");
    fortranOptions.predefinitions.emplace_back(
        "__flang_major__", FLANG_VERSION_MAJOR_STRING);
    fortranOptions.predefinitions.emplace_back(
        "__flang_minor__", FLANG_VERSION_MINOR_STRING);
    fortranOptions.predefinitions.emplace_back(
        "__flang_patchlevel__", FLANG_VERSION_PATCHLEVEL_STRING);
  
    // Add predefinitions based on extensions enabled
    if (frontendOptions.features_.IsEnabled(
            Fortran::common::LanguageFeature::OpenACC)) {
      fortranOptions.predefinitions.emplace_back("_OPENACC", "202011");
    }
    if (frontendOptions.features_.IsEnabled(
            Fortran::common::LanguageFeature::OpenMP)) {
      fortranOptions.predefinitions.emplace_back("_OPENMP", "201511");
    }
  }
  
  void CompilerInvocation::setFortranOpts() {
    auto &fortranOptions = fortranOpts();
    const auto &frontendOptions = frontendOpts();
    const auto &preprocessorOptions = preprocessorOpts();
    auto &moduleDirJ = moduleDir();
  
    if (frontendOptions.fortranForm_ != FortranForm::Unknown) {
      fortranOptions.isFixedForm =
          frontendOptions.fortranForm_ == FortranForm::FixedForm;
    }
    fortranOptions.fixedFormColumns = frontendOptions.fixedFormColumns_;
  
    fortranOptions.features = frontendOptions.features_;
    fortranOptions.encoding = frontendOptions.encoding_;
  
    collectMacroDefinitions(preprocessorOptions, fortranOptions);
  
    fortranOptions.searchDirectories.insert(
        fortranOptions.searchDirectories.end(),
        preprocessorOptions.searchDirectoriesFromDashI.begin(),
        preprocessorOptions.searchDirectoriesFromDashI.end());
  
    // Add the directory supplied through -J/-module-dir to the list of search
    // directories
    if (moduleDirJ.compare(".") != 0)
      fortranOptions.searchDirectories.emplace_back(moduleDirJ);
  
    if (frontendOptions.instrumentedParse_)
      fortranOptions.instrumentedParse = true;
  }
  
  void CompilerInvocation::setSemanticsOpts(
      Fortran::parser::AllCookedSources &allCookedSources) {
    const auto &fortranOptions = fortranOpts();
  
    semanticsContext_ = std::make_unique<semantics::SemanticsContext>(
        defaultKinds(), fortranOptions.features, allCookedSources);
  
    semanticsContext_->set_moduleDirectory(moduleDir())
        .set_searchDirectories(fortranOptions.searchDirectories);
  }
  