bool CommandLineParser::ParseCommandLineOptions()

in lib/LLVMSupport/Support/CommandLine.cpp [1156:1486]


bool CommandLineParser::ParseCommandLineOptions(int argc,
                                                const char *const *argv,
                                                StringRef Overview,
                                                raw_ostream *Errs) {
  assert(hasOptions() && "No options specified!");

  // Expand response files.
  SmallVector<const char *, 20> newArgv(argv, argv + argc);
  BumpPtrAllocator A;
  StringSaver Saver(A);
  ExpandResponseFiles(Saver,
         Triple(sys::getProcessTriple()).isOSWindows() ?
         cl::TokenizeWindowsCommandLine : cl::TokenizeGNUCommandLine,
         newArgv);
  argv = &newArgv[0];
  argc = static_cast<int>(newArgv.size());

  // Copy the program name into ProgName, making sure not to overflow it.
  ProgramName = sys::path::filename(StringRef(argv[0]));

  ProgramOverview = Overview;
  bool IgnoreErrors = Errs;
  if (!Errs)
    Errs = &errs();
  bool ErrorParsing = false;

  // Check out the positional arguments to collect information about them.
  unsigned NumPositionalRequired = 0;

  // Determine whether or not there are an unlimited number of positionals
  bool HasUnlimitedPositionals = false;

  int FirstArg = 1;
  SubCommand *ChosenSubCommand = &*TopLevelSubCommand;
  if (argc >= 2 && argv[FirstArg][0] != '-') {
    // If the first argument specifies a valid subcommand, start processing
    // options from the second argument.
    ChosenSubCommand = LookupSubCommand(StringRef(argv[FirstArg]));
    if (ChosenSubCommand != &*TopLevelSubCommand)
      FirstArg = 2;
  }
  GlobalParser->ActiveSubCommand = ChosenSubCommand;

  assert(ChosenSubCommand);
  auto &ConsumeAfterOpt = ChosenSubCommand->ConsumeAfterOpt;
  auto &PositionalOpts = ChosenSubCommand->PositionalOpts;
  auto &SinkOpts = ChosenSubCommand->SinkOpts;
  auto &OptionsMap = ChosenSubCommand->OptionsMap;

  for (auto O: DefaultOptions) {
    addOption(O, true);
  }

  if (ConsumeAfterOpt) {
    assert(PositionalOpts.size() > 0 &&
           "Cannot specify cl::ConsumeAfter without a positional argument!");
  }
  if (!PositionalOpts.empty()) {

    // Calculate how many positional values are _required_.
    bool UnboundedFound = false;
    for (size_t i = 0, e = PositionalOpts.size(); i != e; ++i) {
      Option *Opt = PositionalOpts[i];
      if (RequiresValue(Opt))
        ++NumPositionalRequired;
      else if (ConsumeAfterOpt) {
        // ConsumeAfter cannot be combined with "optional" positional options
        // unless there is only one positional argument...
        if (PositionalOpts.size() > 1) {
          if (!IgnoreErrors)
            Opt->error("error - this positional option will never be matched, "
                       "because it does not Require a value, and a "
                       "cl::ConsumeAfter option is active!");
          ErrorParsing = true;
        }
      } else if (UnboundedFound && !Opt->hasArgStr()) {
        // This option does not "require" a value...  Make sure this option is
        // not specified after an option that eats all extra arguments, or this
        // one will never get any!
        //
        if (!IgnoreErrors)
          Opt->error("error - option can never match, because "
                     "another positional argument will match an "
                     "unbounded number of values, and this option"
                     " does not require a value!");
        *Errs << ProgramName << ": CommandLine Error: Option '" << Opt->ArgStr
              << "' is all messed up!\n";
        *Errs << PositionalOpts.size();
        ErrorParsing = true;
      }
      UnboundedFound |= EatsUnboundedNumberOfValues(Opt);
    }
    HasUnlimitedPositionals = UnboundedFound || ConsumeAfterOpt;
  }

  // PositionalVals - A vector of "positional" arguments we accumulate into
  // the process at the end.
  //
  SmallVector<std::pair<StringRef, unsigned>, 4> PositionalVals;

  // If the program has named positional arguments, and the name has been run
  // across, keep track of which positional argument was named.  Otherwise put
  // the positional args into the PositionalVals list...
  Option *ActivePositionalArg = nullptr;

  // Loop over all of the arguments... processing them.
  bool DashDashFound = false; // Have we read '--'?
  for (int i = FirstArg; i < argc; ++i) {
    Option *Handler = nullptr;
    Option *NearestHandler = nullptr;
    std::string NearestHandlerString;
    StringRef Value;
    StringRef ArgName = "";

    // Check to see if this is a positional argument.  This argument is
    // considered to be positional if it doesn't start with '-', if it is "-"
    // itself, or if we have seen "--" already.
    //
    if (argv[i][0] != '-' || argv[i][1] == 0 || DashDashFound) {
      // Positional argument!
      if (ActivePositionalArg) {
        ProvidePositionalOption(ActivePositionalArg, StringRef(argv[i]), i);
        continue; // We are done!
      }

      if (!PositionalOpts.empty()) {
        PositionalVals.push_back(std::make_pair(StringRef(argv[i]), i));

        // All of the positional arguments have been fulfulled, give the rest to
        // the consume after option... if it's specified...
        //
        if (PositionalVals.size() >= NumPositionalRequired && ConsumeAfterOpt) {
          for (++i; i < argc; ++i)
            PositionalVals.push_back(std::make_pair(StringRef(argv[i]), i));
          break; // Handle outside of the argument processing loop...
        }

        // Delay processing positional arguments until the end...
        continue;
      }
    } else if (argv[i][0] == '-' && argv[i][1] == '-' && argv[i][2] == 0 &&
               !DashDashFound) {
      DashDashFound = true; // This is the mythical "--"?
      continue;             // Don't try to process it as an argument itself.
    } else if (ActivePositionalArg &&
               (ActivePositionalArg->getMiscFlags() & PositionalEatsArgs)) {
      // If there is a positional argument eating options, check to see if this
      // option is another positional argument.  If so, treat it as an argument,
      // otherwise feed it to the eating positional.
      ArgName = StringRef(argv[i] + 1);
      // Eat leading dashes.
      while (!ArgName.empty() && ArgName[0] == '-')
        ArgName = ArgName.substr(1);

      Handler = LookupOption(*ChosenSubCommand, ArgName, Value);
      if (!Handler || Handler->getFormattingFlag() != cl::Positional) {
        ProvidePositionalOption(ActivePositionalArg, StringRef(argv[i]), i);
        continue; // We are done!
      }

    } else { // We start with a '-', must be an argument.
      ArgName = StringRef(argv[i] + 1);
      // Eat leading dashes.
      while (!ArgName.empty() && ArgName[0] == '-')
        ArgName = ArgName.substr(1);

      Handler = LookupOption(*ChosenSubCommand, ArgName, Value);

      // Check to see if this "option" is really a prefixed or grouped argument.
      if (!Handler)
        Handler = HandlePrefixedOrGroupedOption(ArgName, Value, ErrorParsing,
                                                OptionsMap);

      // Otherwise, look for the closest available option to report to the user
      // in the upcoming error.
      if (!Handler && SinkOpts.empty())
        NearestHandler =
            LookupNearestOption(ArgName, OptionsMap, NearestHandlerString);
    }

    if (!Handler) {
      if (SinkOpts.empty()) {
        *Errs << ProgramName << ": Unknown command line argument '" << argv[i]
              << "'.  Try: '" << argv[0] << " -help'\n";

        if (NearestHandler) {
          // If we know a near match, report it as well.
          *Errs << ProgramName << ": Did you mean '-" << NearestHandlerString
                 << "'?\n";
        }

        ErrorParsing = true;
      } else {
        for (SmallVectorImpl<Option *>::iterator I = SinkOpts.begin(),
                                                 E = SinkOpts.end();
             I != E; ++I)
          (*I)->addOccurrence(i, "", StringRef(argv[i]));
      }
      continue;
    }

    // If this is a named positional argument, just remember that it is the
    // active one...
    if (Handler->getFormattingFlag() == cl::Positional) {
      if ((Handler->getMiscFlags() & PositionalEatsArgs) && !Value.empty()) {
        Handler->error("This argument does not take a value.\n"
                       "\tInstead, it consumes any positional arguments until "
                       "the next recognized option.", *Errs);
        ErrorParsing = true;
      }
      ActivePositionalArg = Handler;
    }
    else
      ErrorParsing |= ProvideOption(Handler, ArgName, Value, argc, argv, i);
  }

  // Check and handle positional arguments now...
  if (NumPositionalRequired > PositionalVals.size()) {
      *Errs << ProgramName
             << ": Not enough positional command line arguments specified!\n"
             << "Must specify at least " << NumPositionalRequired
             << " positional argument" << (NumPositionalRequired > 1 ? "s" : "")
             << ": See: " << argv[0] << " -help\n";

    ErrorParsing = true;
  } else if (!HasUnlimitedPositionals &&
             PositionalVals.size() > PositionalOpts.size()) {
    *Errs << ProgramName << ": Too many positional arguments specified!\n"
          << "Can specify at most " << PositionalOpts.size()
          << " positional arguments: See: " << argv[0] << " -help\n";
    ErrorParsing = true;

  } else if (!ConsumeAfterOpt) {
    // Positional args have already been handled if ConsumeAfter is specified.
    unsigned ValNo = 0, NumVals = static_cast<unsigned>(PositionalVals.size());
    for (size_t i = 0, e = PositionalOpts.size(); i != e; ++i) {
      if (RequiresValue(PositionalOpts[i])) {
        ProvidePositionalOption(PositionalOpts[i], PositionalVals[ValNo].first,
                                PositionalVals[ValNo].second);
        ValNo++;
        --NumPositionalRequired; // We fulfilled our duty...
      }

      // If we _can_ give this option more arguments, do so now, as long as we
      // do not give it values that others need.  'Done' controls whether the
      // option even _WANTS_ any more.
      //
      bool Done = PositionalOpts[i]->getNumOccurrencesFlag() == cl::Required;
      while (NumVals - ValNo > NumPositionalRequired && !Done) {
        switch (PositionalOpts[i]->getNumOccurrencesFlag()) {
        case cl::Optional:
          Done = true; // Optional arguments want _at most_ one value
          LLVM_FALLTHROUGH;
        case cl::ZeroOrMore: // Zero or more will take all they can get...
        case cl::OneOrMore:  // One or more will take all they can get...
          ProvidePositionalOption(PositionalOpts[i],
                                  PositionalVals[ValNo].first,
                                  PositionalVals[ValNo].second);
          ValNo++;
          break;
        default:
          llvm_unreachable("Internal error, unexpected NumOccurrences flag in "
                           "positional argument processing!");
        }
      }
    }
  } else {
    assert(ConsumeAfterOpt && NumPositionalRequired <= PositionalVals.size());
    unsigned ValNo = 0;
    for (size_t j = 1, e = PositionalOpts.size(); j != e; ++j)
      if (RequiresValue(PositionalOpts[j])) {
        ErrorParsing |= ProvidePositionalOption(PositionalOpts[j],
                                                PositionalVals[ValNo].first,
                                                PositionalVals[ValNo].second);
        ValNo++;
      }

    // Handle the case where there is just one positional option, and it's
    // optional.  In this case, we want to give JUST THE FIRST option to the
    // positional option and keep the rest for the consume after.  The above
    // loop would have assigned no values to positional options in this case.
    //
    if (PositionalOpts.size() == 1 && ValNo == 0 && !PositionalVals.empty()) {
      ErrorParsing |= ProvidePositionalOption(PositionalOpts[0],
                                              PositionalVals[ValNo].first,
                                              PositionalVals[ValNo].second);
      ValNo++;
    }

    // Handle over all of the rest of the arguments to the
    // cl::ConsumeAfter command line option...
    for (; ValNo != PositionalVals.size(); ++ValNo)
      ErrorParsing |=
          ProvidePositionalOption(ConsumeAfterOpt, PositionalVals[ValNo].first,
                                  PositionalVals[ValNo].second);
  }

  // Loop over args and make sure all required args are specified!
  for (const auto &Opt : OptionsMap) {
    switch (Opt.second->getNumOccurrencesFlag()) {
    case Required:
    case OneOrMore:
      if (Opt.second->getNumOccurrences() == 0) {
        Opt.second->error("must be specified at least once!");
        ErrorParsing = true;
      }
      LLVM_FALLTHROUGH;
    default:
      break;
    }
  }

  // Now that we know if -debug is specified, we can use it.
  // Note that if ReadResponseFiles == true, this must be done before the
  // memory allocated for the expanded command line is free()d below.
  LLVM_DEBUG(dbgs() << "Args: ";
             for (int i = 0; i < argc; ++i) dbgs() << argv[i] << ' ';
             dbgs() << '\n';);

  // Free all of the memory allocated to the map.  Command line options may only
  // be processed once!
  MoreHelp.clear();

  // If we had an error processing our arguments, don't let the program execute
  if (ErrorParsing) {
    if (!IgnoreErrors)
      exit(1);
    return false;
  }
  return true;
}