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 "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Streams.h"
#include "llvm/System/Path.h"
#include <algorithm>
#include <functional>
#include <map>
#include <ostream>
#include <set>
#include <cstdlib>
#include <cerrno>
#include <cstring>
using namespace llvm;
using namespace cl;

//===----------------------------------------------------------------------===//
// Template instantiations and anchors.
//
TEMPLATE_INSTANTIATION(class basic_parser<bool>);
TEMPLATE_INSTANTIATION(class basic_parser<int>);
TEMPLATE_INSTANTIATION(class basic_parser<unsigned>);
TEMPLATE_INSTANTIATION(class basic_parser<double>);
TEMPLATE_INSTANTIATION(class basic_parser<float>);
TEMPLATE_INSTANTIATION(class basic_parser<std::string>);

TEMPLATE_INSTANTIATION(class opt<unsigned>);
TEMPLATE_INSTANTIATION(class opt<int>);
TEMPLATE_INSTANTIATION(class opt<std::string>);
TEMPLATE_INSTANTIATION(class opt<bool>);

void Option::anchor() {}
void basic_parser_impl::anchor() {}
void parser<bool>::anchor() {}
void parser<int>::anchor() {}
void parser<unsigned>::anchor() {}
void parser<double>::anchor() {}
void parser<float>::anchor() {}
void parser<std::string>::anchor() {}

//===----------------------------------------------------------------------===//

// Globals for name and overview of program.  Program name is not a string to
// avoid static ctor/dtor issues.
static char ProgramName[80] = "<premain>";
static const char *ProgramOverview = 0;

// This collects additional help to be printed.
static ManagedStatic<std::vector<const char*> > MoreHelp;

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

/// RegisteredOptionList - This is the list of the command line options that
/// have statically constructed themselves.
static Option *RegisteredOptionList = 0;

void Option::addArgument() {
  assert(NextRegistered == 0 && "argument multiply registered!");
  
  NextRegistered = RegisteredOptionList;
  RegisteredOptionList = this;
}

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

/// GetOptionInfo - Scan the list of registered options, turning them into data
/// structures that are easier to handle.
static void GetOptionInfo(std::vector<Option*> &PositionalOpts,
                          std::map<std::string, Option*> &OptionsMap) {
  std::vector<const char*> OptionNames;
  for (Option *O = RegisteredOptionList; O; O = O->getNextRegisteredOption()) {
    // If this option wants to handle multiple option names, get the full set.
    // This handles enum options like "-O1 -O2" etc.
    O->getExtraOptionNames(OptionNames);
    if (O->ArgStr[0])
      OptionNames.push_back(O->ArgStr);
    
    // Handle named options.
    for (unsigned i = 0, e = OptionNames.size(); i != e; ++i) {
      // Add argument to the argument map!
      if (!OptionsMap.insert(std::pair<std::string,Option*>(OptionNames[i],
                                                            O)).second) {
        cerr << ProgramName << ": CommandLine Error: Argument '"
             << OptionNames[0] << "' defined more than once!\n";
      }
    }
    
    OptionNames.clear();
    
    // Remember information about positional options.
    if (O->getFormattingFlag() == cl::Positional)
      PositionalOpts.push_back(O);
    else if (O->getNumOccurrencesFlag() == cl::ConsumeAfter) {
      if (!PositionalOpts.empty() &&
          PositionalOpts.front()->getNumOccurrencesFlag() == cl::ConsumeAfter)
        O->error("Cannot specify more than one option with cl::ConsumeAfter!");
      PositionalOpts.insert(PositionalOpts.begin(), O);
    }
  }
}


/// LookupOption - Lookup the option specified by the specified option on the
/// command line.  If there is a value specified (after an equal sign) return
/// that as well.
static Option *LookupOption(const char *&Arg, const char *&Value,
                            std::map<std::string, Option*> &OptionsMap) {
  while (*Arg == '-') ++Arg;  // Eat leading dashes
  
  const char *ArgEnd = Arg;
  while (*ArgEnd && *ArgEnd != '=')
    ++ArgEnd; // Scan till end of argument name.
  
  if (*ArgEnd == '=')  // If we have an equals sign...
    Value = ArgEnd+1;  // Get the value, not the equals
  
  
  if (*Arg == 0) return 0;
  
  // Look up the option.
  std::map<std::string, Option*>::iterator I =
    OptionsMap.find(std::string(Arg, ArgEnd));
  return I != OptionsMap.end() ? I->second : 0;
}

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:
    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,