CommandLine.cpp

//===-- CommandLine.cpp - Command line parser implementation --------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements a command line argument processor that is useful when
// creating a tool.  It provides a simple, minimalistic interface that is easily
// extensible and supports nonlocal (library) command line options.
//
// Note that rather than trying to figure out what this code does, you could try
// reading the library documentation located in docs/CommandLine.html
//
//===----------------------------------------------------------------------===//

#include "llvm/Config/config.h"
#include "llvm/Support/CommandLine.h"
#include <algorithm>
#include <functional>
#include <map>
#include <set>
#include <iostream>
#include <cstdlib>
#include <cerrno>
#include <cstring>
using namespace llvm;

using namespace cl;

// Globals for name and overview of program
static const char *ProgramName = "<unknown>";
static const char *ProgramOverview = 0;

// This collects additional help to be printed.
static std::vector<const char*> &MoreHelp() {
  static std::vector<const char*> moreHelp;
  return moreHelp;
}

extrahelp::extrahelp(const char* Help)
  : morehelp(Help) {
  MoreHelp().push_back(Help);
}

//===----------------------------------------------------------------------===//
// Basic, shared command line option processing machinery...
//

// Return the global command line option vector.  Making it a function scoped
// static ensures that it will be initialized correctly before its first use.
//
static std::map<std::string, Option*> &getOpts() {
  static std::map<std::string, Option*> CommandLineOptions;
  return CommandLineOptions;
}

static Option *getOption(const std::string &Str) {
  std::map<std::string,Option*>::iterator I = getOpts().find(Str);
  return I != getOpts().end() ? I->second : 0;
}

static std::vector<Option*> &getPositionalOpts() {
  static std::vector<Option*> Positional;
  return Positional;
}

static void AddArgument(const char *ArgName, Option *Opt) {
  if (getOption(ArgName)) {
    std::cerr << ProgramName << ": CommandLine Error: Argument '"
              << ArgName << "' defined more than once!\n";
  } else {
    // Add argument to the argument map!
    getOpts()[ArgName] = Opt;
  }
}

// RemoveArgument - It's possible that the argument is no longer in the map if
// options have already been processed and the map has been deleted!
//
static void RemoveArgument(const char *ArgName, Option *Opt) {
  if(getOpts().empty()) return;

#ifndef NDEBUG
  // This disgusting HACK is brought to you courtesy of GCC 3.3.2, which ICE's
  // If we pass ArgName directly into getOption here.
  std::string Tmp = ArgName;
  assert(getOption(Tmp) == Opt && "Arg not in map!");
#endif
  getOpts().erase(ArgName);
}

static inline bool ProvideOption(Option *Handler, const char *ArgName,
                                 const char *Value, int argc, char **argv,
                                 int &i) {
  // Enforce value requirements
  switch (Handler->getValueExpectedFlag()) {
  case ValueRequired:
    if (Value == 0) {       // No value specified?
      if (i+1 < argc) {     // Steal the next argument, like for '-o filename'
        Value = argv[++i];
      } else {
        return Handler->error(" requires a value!");
      }
    }
    break;
  case ValueDisallowed:
    if (Value)
      return Handler->error(" does not allow a value! '" +
                            std::string(Value) + "' specified.");
    break;
  case ValueOptional:
    break;
  default:
    std::cerr << ProgramName
              << ": Bad ValueMask flag! CommandLine usage error:"
              << Handler->getValueExpectedFlag() << "\n";
    abort();
    break;
  }

  // Run the handler now!
  return Handler->addOccurrence(i, ArgName, Value ? Value : "");
}

static bool ProvidePositionalOption(Option *Handler, const std::string &Arg,
                                    int i) {
  int Dummy = i;
  return ProvideOption(Handler, Handler->ArgStr, Arg.c_str(), 0, 0, Dummy);
}


// Option predicates...
static inline bool isGrouping(const Option *O) {
  return O->getFormattingFlag() == cl::Grouping;
}
static inline bool isPrefixedOrGrouping(const Option *O) {
  return isGrouping(O) || O->getFormattingFlag() == cl::Prefix;
}

// getOptionPred - Check to see if there are any options that satisfy the
// specified predicate with names that are the prefixes in Name.  This is
// checked by progressively stripping characters off of the name, checking to
// see if there options that satisfy the predicate.  If we find one, return it,
// otherwise return null.
//
static Option *getOptionPred(std::string Name, unsigned &Length,
                             bool (*Pred)(const Option*)) {

  Option *Op = getOption(Name);
  if (Op && Pred(Op)) {
    Length = Name.length();
    return Op;
  }

  if (Name.size() == 1) return 0;
  do {
    Name.erase(Name.end()-1, Name.end());   // Chop off the last character...
    Op = getOption(Name);

    // Loop while we haven't found an option and Name still has at least two
    // characters in it (so that the next iteration will not be the empty
    // string...
  } while ((Op == 0 || !Pred(Op)) && Name.size() > 1);

  if (Op && Pred(Op)) {
    Length = Name.length();
    return Op;             // Found one!
  }
  return 0;                // No option found!
}

static bool RequiresValue(const Option *O) {
  return O->getNumOccurrencesFlag() == cl::Required ||
         O->getNumOccurrencesFlag() == cl::OneOrMore;
}

static bool EatsUnboundedNumberOfValues(const Option *O) {
  return O->getNumOccurrencesFlag() == cl::ZeroOrMore ||
         O->getNumOccurrencesFlag() == cl::OneOrMore;
}

/// ParseCStringVector - Break INPUT up wherever one or more
/// whitespace characters are found, and store the resulting tokens in
/// OUTPUT. The tokens stored in OUTPUT are dynamically allocated
/// using strdup (), so it is the caller's responsibility to free ()
/// them later.
///
static void ParseCStringVector (std::vector<char *> &output,
                                const char *input) {
  // Characters which will be treated as token separators:
  static const char *delims = " \v\f\t\r\n";

  std::string work (input);
  // Skip past any delims at head of input string.
  size_t pos = work.find_first_not_of (delims);
  // If the string consists entirely of delims, then exit early.
  if (pos == std::string::npos) return;