text: // options.c -- handle command line options for gold
  
  // Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
  // Written by Ian Lance Taylor <iant@google.com>.
  
  // This file is part of gold.
  
  // This program is free software; you can redistribute it and/or modify
  // it under the terms of the GNU General Public License as published by
  // the Free Software Foundation; either version 3 of the License, or
  // (at your option) any later version.
  
  // This program is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  // GNU General Public License for more details.
  
  // You should have received a copy of the GNU General Public License
  // along with this program; if not, write to the Free Software
  // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  // MA 02110-1301, USA.
  
  #include "gold.h"
  
  #include <cerrno>
  #include <cstdlib>
  #include <cstring>
  #include <fstream>
  #include <vector>
  #include <iostream>
  #include <sys/stat.h>
  #include "filenames.h"
  #include "libiberty.h"
  #include "demangle.h"
  #include "../bfd/bfdver.h"
  
  #include "debug.h"
  #include "script.h"
  #include "target-select.h"
  #include "options.h"
  #include "plugin.h"
  
  namespace gold
  {
  
  General_options
  Position_dependent_options::default_options_;
  
  namespace options
  {
  
  // This flag is TRUE if we should register the command-line options as they
  // are constructed.  It is set after construction of the options within
  // class Position_dependent_options.
  static bool ready_to_register = false;
  
  // This global variable is set up as General_options is constructed.
  static std::vector<const One_option*> registered_options;
  
  // These are set up at the same time -- the variables that accept one
  // dash, two, or require -z.  A single variable may be in more than
  // one of these data structures.
  typedef Unordered_map<std::string, One_option*> Option_map;
  static Option_map* long_options = NULL;
  static One_option* short_options[128];
  
  void
  One_option::register_option()
  {
    if (!ready_to_register)
      return;
  
    registered_options.push_back(this);
  
    // We can't make long_options a static Option_map because we can't
    // guarantee that will be initialized before register_option() is
    // first called.
    if (long_options == NULL)
      long_options = new Option_map;
  
    // TWO_DASHES means that two dashes are preferred, but one is ok too.
    if (!this->longname.empty())
      (*long_options)[this->longname] = this;
  
    const int shortname_as_int = static_cast<int>(this->shortname);
    gold_assert(shortname_as_int >= 0 && shortname_as_int < 128);
    if (this->shortname != '\0')
      {
        gold_assert(short_options[shortname_as_int] == NULL);
        short_options[shortname_as_int] = this;
      }
  }
  
  void
  One_option::print() const
  {
    bool comma = false;
    printf("  ");
    int len = 2;
    if (this->shortname != '\0')
      {
        len += printf("-%c", this->shortname);
        if (this->helparg)
          {
            // -z takes long-names only.
            gold_assert(this->dashes != DASH_Z);
            len += printf(" %s", gettext(this->helparg));
          }
        comma = true;
      }
    if (!this->longname.empty()
        && !(this->longname[0] == this->shortname
  	   && this->longname[1] == '\0'))
      {
        if (comma)
          len += printf(", ");
        switch (this->dashes)
          {
          case options::ONE_DASH: case options::EXACTLY_ONE_DASH:
            len += printf("-");
            break;
          case options::TWO_DASHES: case options::EXACTLY_TWO_DASHES:
            len += printf("--");
            break;
          case options::DASH_Z:
            len += printf("-z ");
            break;
          default:
            gold_unreachable();
          }
        len += printf("%s", this->longname.c_str());
        if (this->helparg)
          {
            // For most options, we print "--frob FOO".  But for -z
            // we print "-z frob=FOO".
            len += printf("%c%s", this->dashes == options::DASH_Z ? '=' : ' ',
                          gettext(this->helparg));
          }
      }
  
    if (len >= 30)
      {
        printf("\n");
        len = 0;
      }
    for (; len < 30; ++len)
      std::putchar(' ');
  
    // TODO: if we're boolean, add " (default)" when appropriate.
    printf("%s\n", gettext(this->helpstring));
  }
  
  void
  help()
  {
    printf(_("Usage: %s [options] file...\nOptions:\n"), gold::program_name);
  
    std::vector<const One_option*>::const_iterator it;
    for (it = registered_options.begin(); it != registered_options.end(); ++it)
      (*it)->print();
  
    // config.guess and libtool.m4 look in ld --help output for the
    // string "supported targets".
    printf(_("%s: supported targets:"), gold::program_name);
    std::vector<const char*> supported_names;
    gold::supported_target_names(&supported_names);
    for (std::vector<const char*>::const_iterator p = supported_names.begin();
         p != supported_names.end();
         ++p)
      printf(" %s", *p);
    printf("\n");
  
    printf(_("%s: supported emulations:"), gold::program_name);
    supported_names.clear();
    gold::supported_emulation_names(&supported_names);
    for (std::vector<const char*>::const_iterator p = supported_names.begin();
         p != supported_names.end();
         ++p)
      printf(" %s", *p);
    printf("\n");
  
    // REPORT_BUGS_TO is defined in bfd/bfdver.h.
    const char* report = REPORT_BUGS_TO;
    if (*report != '\0')
      printf(_("Report bugs to %s\n"), report);
  }
  
  // For bool, arg will be NULL (boolean options take no argument);
  // we always just set to true.
  void
  parse_bool(const char*, const char*, bool* retval)
  {
    *retval = true;
  }
  
  void
  parse_uint(const char* option_name, const char* arg, int* retval)
  {
    char* endptr;
    *retval = strtol(arg, &endptr, 0);
    if (*endptr != '\0' || retval < 0)
      gold_fatal(_("%s: invalid option value (expected an integer): %s"),
                 option_name, arg);
  }
  
  void
  parse_int(const char* option_name, const char* arg, int* retval)
  {
    char* endptr;
    *retval = strtol(arg, &endptr, 0);
    if (*endptr != '\0')
      gold_fatal(_("%s: invalid option value (expected an integer): %s"),
                 option_name, arg);
  }
  
  void
  parse_uint64(const char* option_name, const char* arg, uint64_t* retval)
  {
    char* endptr;
    *retval = strtoull(arg, &endptr, 0);
    if (*endptr != '\0')
      gold_fatal(_("%s: invalid option value (expected an integer): %s"),
                 option_name, arg);
  }
  
  void
  parse_double(const char* option_name, const char* arg, double* retval)
  {
    char* endptr;
    *retval = strtod(arg, &endptr);
    if (*endptr != '\0')
      gold_fatal(_("%s: invalid option value "
  		 "(expected a floating point number): %s"),
  	       option_name, arg);
  }
  
  void
  parse_percent(const char* option_name, const char* arg, double* retval)
  {
    char* endptr;
    *retval = strtod(arg, &endptr) / 100.0;
    if (*endptr != '\0')
      gold_fatal(_("%s: invalid option value "
  		 "(expected a floating point number): %s"),
  	       option_name, arg);
  }
  
  void
  parse_string(const char* option_name, const char* arg, const char** retval)
  {
    if (*arg == '\0')
      gold_fatal(_("%s: must take a non-empty argument"), option_name);
    *retval = arg;
  }
  
  void
  parse_optional_string(const char*, const char* arg, const char** retval)
  {
    *retval = arg;
  }
  
  void
  parse_dirlist(const char*, const char* arg, Dir_list* retval)
  {
    retval->push_back(Search_directory(arg, false));
  }
  
  void
  parse_set(const char*, const char* arg, String_set* retval)
  {
    retval->insert(std::string(arg));
  }
  
  void
  parse_choices(const char* option_name, const char* arg, const char** retval,
                const char* choices[], int num_choices)
  {
    for (int i = 0; i < num_choices; i++)
      if (strcmp(choices[i], arg) == 0)
        {
          *retval = arg;
          return;
        }
  
    // If we get here, the user did not enter a valid choice, so we die.
    std::string choices_list;
    for (int i = 0; i < num_choices; i++)
      {
        choices_list += choices[i];
        if (i != num_choices - 1)
          choices_list += ", ";
      }
    gold_fatal(_("%s: must take one of the following arguments: %s"),
               option_name, choices_list.c_str());
  }
  
  } // End namespace options.
  
  // Define the handler for "special" options (set via DEFINE_special).
  
  void
  General_options::parse_help(const char*, const char*, Command_line*)
  {
    options::help();
    ::exit(EXIT_SUCCESS);
  }
  
  void
  General_options::parse_version(const char* opt, const char*, Command_line*)
  {
    bool print_short = (opt[0] == '-' && opt[1] == 'v');
    gold::print_version(print_short);
    this->printed_version_ = true;
    if (!print_short)
      ::exit(EXIT_SUCCESS);
  }
  
  void
  General_options::parse_V(const char*, const char*, Command_line*)
  {
    gold::print_version(true);
    this->printed_version_ = true;
  
    printf(_("  Supported targets:\n"));
    std::vector<const char*> supported_names;
    gold::supported_target_names(&supported_names);
    for (std::vector<const char*>::const_iterator p = supported_names.begin();
         p != supported_names.end();
         ++p)
      printf("   %s\n", *p);
  
    printf(_("  Supported emulations:\n"));
    supported_names.clear();
    gold::supported_emulation_names(&supported_names);
    for (std::vector<const char*>::const_iterator p = supported_names.begin();
         p != supported_names.end();
         ++p)
      printf("   %s\n", *p);
  }
  
  void
  General_options::parse_defsym(const char*, const char* arg,
                                Command_line* cmdline)
  {
    cmdline->script_options().define_symbol(arg);
  }
  
  void
  General_options::parse_incremental(const char*, const char*,
                                     Command_line*)
  {
    this->incremental_mode_ = INCREMENTAL_AUTO;
  }
  
  void
  General_options::parse_no_incremental(const char*, const char*,
                                        Command_line*)
  {
    this->incremental_mode_ = INCREMENTAL_OFF;
  }
  
  void
  General_options::parse_incremental_full(const char*, const char*,
  					Command_line*)
  {
    this->incremental_mode_ = INCREMENTAL_FULL;
  }
  
  void
  General_options::parse_incremental_update(const char*, const char*,
  					  Command_line*)
  {
    this->incremental_mode_ = INCREMENTAL_UPDATE;
  }
  
  void
  General_options::parse_incremental_changed(const char*, const char*,
                                             Command_line*)
  {
    this->implicit_incremental_ = true;
    this->incremental_disposition_ = INCREMENTAL_CHANGED;
  }
  
  void
  General_options::parse_incremental_unchanged(const char*, const char*,
                                               Command_line*)
  {
    this->implicit_incremental_ = true;
    this->incremental_disposition_ = INCREMENTAL_UNCHANGED;
  }
  
  void
  General_options::parse_incremental_unknown(const char*, const char*,
                                             Command_line*)
  {
    this->implicit_incremental_ = true;
    this->incremental_disposition_ = INCREMENTAL_CHECK;
  }
  
  void
  General_options::parse_incremental_startup_unchanged(const char*, const char*,
  						     Command_line*)
  {
    this->implicit_incremental_ = true;
    this->incremental_startup_disposition_ = INCREMENTAL_UNCHANGED;
  }
  
  void
  General_options::parse_library(const char*, const char* arg,
                                 Command_line* cmdline)
  {
    Input_file_argument::Input_file_type type;
    const char* name;
    if (arg[0] == ':')
      {
        type = Input_file_argument::INPUT_FILE_TYPE_SEARCHED_FILE;
        name = arg + 1;
      }
    else
      {
        type = Input_file_argument::INPUT_FILE_TYPE_LIBRARY;
        name = arg;
      }
    Input_file_argument file(name, type, "", false, *this);
    cmdline->inputs().add_file(file);
  }
  
  #ifdef ENABLE_PLUGINS
  void
  General_options::parse_plugin(const char*, const char* arg,
                                Command_line*)
  {
    this->add_plugin(arg);
  }
  
  // Parse --plugin-opt.
  
  void
  General_options::parse_plugin_opt(const char*, const char* arg,
                                    Command_line*)
  {
    this->add_plugin_option(arg);
  }
  #endif // ENABLE_PLUGINS
  
  void
  General_options::parse_R(const char* option, const char* arg,
                           Command_line* cmdline)
  {
    struct stat s;
    if (::stat(arg, &s) != 0 || S_ISDIR(s.st_mode))
      this->add_to_rpath(arg);
    else
      this->parse_just_symbols(option, arg, cmdline);
  }
  
  void
  General_options::parse_just_symbols(const char*, const char* arg,
                                      Command_line* cmdline)
  {
    Input_file_argument file(arg, Input_file_argument::INPUT_FILE_TYPE_FILE,
  			   "", true, *this);
    cmdline->inputs().add_file(file);
  }
  
  // Handle --section-start.
  
  void
  General_options::parse_section_start(const char*, const char* arg,
  				     Command_line*)
  {
    const char* eq = strchr(arg, '=');
    if (eq == NULL)
      {
        gold_error(_("invalid argument to --section-start; "
  		   "must be SECTION=ADDRESS"));
        return;
      }
  
    std::string section_name(arg, eq - arg);
  
    ++eq;
    const char* val_start = eq;
    if (eq[0] == '0' && (eq[1] == 'x' || eq[1] == 'X'))
      eq += 2;
    if (*eq == '\0')
      {
        gold_error(_("--section-start address missing"));
        return;
      }
    uint64_t addr = 0;
    hex_init();
    for (; *eq != '\0'; ++eq)
      {
        if (!hex_p(*eq))
  	{
  	  gold_error(_("--section-start argument %s is not a valid hex number"),
  		     val_start);
  	  return;
  	}
        addr <<= 4;
        addr += hex_value(*eq);
      }
  
    this->section_starts_[section_name] = addr;
  }
  
  // Look up a --section-start value.
  
  bool
  General_options::section_start(const char* secname, uint64_t* paddr) const
  {
    if (this->section_starts_.empty())
      return false;
    std::map<std::string, uint64_t>::const_iterator p =
      this->section_starts_.find(secname);
    if (p == this->section_starts_.end())
      return false;
    *paddr = p->second;
    return true;
  }
  
  void
  General_options::parse_static(const char*, const char*, Command_line*)
  {
    this->set_static(true);
  }
  
  void
  General_options::parse_script(const char*, const char* arg,
                                Command_line* cmdline)
  {
    if (!read_commandline_script(arg, cmdline))
      gold::gold_fatal(_("unable to parse script file %s"), arg);
  }
  
  void
  General_options::parse_version_script(const char*, const char* arg,
                                        Command_line* cmdline)
  {
    if (!read_version_script(arg, cmdline))
      gold::gold_fatal(_("unable to parse version script file %s"), arg);
  }
  
  void
  General_options::parse_dynamic_list(const char*, const char* arg,
                                      Command_line* cmdline)
  {
    if (!read_dynamic_list(arg, cmdline, &this->dynamic_list_))
      gold::gold_fatal(_("unable to parse dynamic-list script file %s"), arg);
  }
  
  void
  General_options::parse_start_group(const char*, const char*,
                                     Command_line* cmdline)
  {
    cmdline->inputs().start_group();
  }
  
  void
  General_options::parse_end_group(const char*, const char*,
                                   Command_line* cmdline)
  {
    cmdline->inputs().end_group();
  }
  
  void
  General_options::parse_start_lib(const char*, const char*,
                                   Command_line* cmdline)
  {
    cmdline->inputs().start_lib(cmdline->position_dependent_options());
  }
  
  void
  General_options::parse_end_lib(const char*, const char*,
                                 Command_line* cmdline)
  {
    cmdline->inputs().end_lib();
  }
  
  // The function add_excluded_libs() in ld/ldlang.c of GNU ld breaks up a list
  // of names separated by commas or colons and puts them in a linked list.
  // We implement the same parsing of names here but store names in an unordered
  // map to speed up searching of names.
  
  void
  General_options::parse_exclude_libs(const char*, const char* arg,
                                      Command_line*)
  {
    const char* p = arg;
  
    while (*p != '\0')
      {
        size_t length = strcspn(p, ",:");
        this->excluded_libs_.insert(std::string(p, length));
        p += (p[length] ? length + 1 : length);
      }
  }
  
  // The checking logic is based on the function check_excluded_libs() in
  // ld/ldlang.c of GNU ld but our implementation is different because we use
  // an unordered map instead of a linked list, which is what GNU ld uses.  GNU
  // ld searches sequentially in the excluded libs list.  For a given archive,
  // a match is found if the archive's name matches exactly one of the list
  // entry or if the archive's name is of the form FOO.a and FOO matches exactly
  // one of the list entry.  An entry "ALL" in the list is considered as a
  // wild-card and matches any given name.
  
  bool
  General_options::check_excluded_libs(const std::string &name) const
  {
    Unordered_set<std::string>::const_iterator p;
  
    // Exit early for the most common case.
    if (excluded_libs_.empty())
      return false;
  
    // If we see "ALL", all archives are excluded from automatic export.
    p = excluded_libs_.find(std::string("ALL"));
    if (p != excluded_libs_.end())
      return true;
  
    // First strip off any directories in name.
    const char* basename = lbasename(name.c_str());
  
    // Try finding an exact match.
    p = excluded_libs_.find(std::string(basename));
    if (p != excluded_libs_.end())
      return true;
  
    // Try matching NAME without ".a" at the end.
    size_t length = strlen(basename);
    if ((length >= 2)
        && (basename[length - 2] == '.')
        && (basename[length - 1] == 'a'))
      {
        p = excluded_libs_.find(std::string(basename, length - 2));
        if (p != excluded_libs_.end())
  	return true;
      }
  
    return false;
  }
  
  // Recognize input and output target names.  The GNU linker accepts
  // these with --format and --oformat.  This code is intended to be
  // minimally compatible.  In practice for an ELF target this would be
  // the same target as the input files; that name always start with
  // "elf".  Non-ELF targets would be "srec", "symbolsrec", "tekhex",
  // "binary", "ihex".
  
  General_options::Object_format
  General_options::string_to_object_format(const char* arg)
  {
    if (strncmp(arg, "elf", 3) == 0)
      return gold::General_options::OBJECT_FORMAT_ELF;
    else if (strcmp(arg, "binary") == 0)
      return gold::General_options::OBJECT_FORMAT_BINARY;
    else
      {
        gold::gold_error(_("format '%s' not supported; treating as elf "
                           "(supported formats: elf, binary)"),
                         arg);
        return gold::General_options::OBJECT_FORMAT_ELF;
      }
  }
  
  void
  General_options::parse_fix_v4bx(const char*, const char*,
                                  Command_line*)
  {
    this->fix_v4bx_ = FIX_V4BX_REPLACE;
  }
  
  void
  General_options::parse_fix_v4bx_interworking(const char*, const char*,
  					     Command_line*)
  {
    this->fix_v4bx_ = FIX_V4BX_INTERWORKING;
  }
  
  void
  General_options::parse_EB(const char*, const char*, Command_line*)
  {
    this->endianness_ = ENDIANNESS_BIG;
  }
  
  void
  General_options::parse_EL(const char*, const char*, Command_line*)
  {
    this->endianness_ = ENDIANNESS_LITTLE;
  }
  
  } // End namespace gold.
  
  namespace
  {
  
  void
  usage()
  {
    fprintf(stderr,
            _("%s: use the --help option for usage information\n"),
            gold::program_name);
    ::exit(EXIT_FAILURE);
  }
  
  void
  usage(const char* msg, const char* opt)
  {
    fprintf(stderr,
            _("%s: %s: %s\n"),
            gold::program_name, opt, msg);
    usage();
  }
  
  // If the default sysroot is relocatable, try relocating it based on
  // the prefix FROM.
  
  static char*
  get_relative_sysroot(const char* from)
  {
    char* path = make_relative_prefix(gold::program_name, from,
                                      TARGET_SYSTEM_ROOT);
    if (path != NULL)
      {
        struct stat s;
        if (::stat(path, &s) == 0 && S_ISDIR(s.st_mode))
          return path;
        free(path);
      }
  
    return NULL;
  }
  
  // Return the default sysroot.  This is set by the --with-sysroot
  // option to configure.  Note we do not free the return value of
  // get_relative_sysroot, which is a small memory leak, but is
  // necessary since we store this pointer directly in General_options.
  
  static const char*
  get_default_sysroot()
  {
    const char* sysroot = TARGET_SYSTEM_ROOT;
    if (*sysroot == '\0')
      return NULL;
  
    if (TARGET_SYSTEM_ROOT_RELOCATABLE)
      {
        char* path = get_relative_sysroot(BINDIR);
        if (path == NULL)
          path = get_relative_sysroot(TOOLBINDIR);
        if (path != NULL)
          return path;
      }
  
    return sysroot;
  }
  
  // Parse a long option.  Such options have the form
  // <-|--><option>[=arg].  If "=arg" is not present but the option
  // takes an argument, the next word is taken to the be the argument.
  // If equals_only is set, then only the <option>=<arg> form is
  // accepted, not the <option><space><arg> form.  Returns a One_option
  // struct or NULL if argv[i] cannot be parsed as a long option.  In
  // the not-NULL case, *arg is set to the option's argument (NULL if
  // the option takes no argument), and *i is advanced past this option.
  // NOTE: it is safe for argv and arg to point to the same place.
  gold::options::One_option*
  parse_long_option(int argc, const char** argv, bool equals_only,
                    const char** arg, int* i)
  {
    const char* const this_argv = argv[*i];
  
    const char* equals = strchr(this_argv, '=');
    const char* option_start = this_argv + strspn(this_argv, "-");
    std::string option(option_start,
                       equals ? equals - option_start : strlen(option_start));
  
    gold::options::Option_map::iterator it
        = gold::options::long_options->find(option);
    if (it == gold::options::long_options->end())
      return NULL;
  
    gold::options::One_option* retval = it->second;
  
    // If the dash-count doesn't match, we fail.
    if (this_argv[0] != '-')  // no dashes at all: had better be "-z <longopt>"
      {
        if (retval->dashes != gold::options::DASH_Z)
          return NULL;
      }
    else if (this_argv[1] != '-')   // one dash
      {
        if (retval->dashes != gold::options::ONE_DASH
            && retval->dashes != gold::options::EXACTLY_ONE_DASH
            && retval->dashes != gold::options::TWO_DASHES)
          return NULL;
      }
    else                            // two dashes (or more!)
      {
        if (retval->dashes != gold::options::TWO_DASHES
            && retval->dashes != gold::options::EXACTLY_TWO_DASHES
            && retval->dashes != gold::options::ONE_DASH)
          return NULL;
      }
  
    // Now that we know the option is good (or else bad in a way that
    // will cause us to die), increment i to point past this argv.
    ++(*i);
  
    // Figure out the option's argument, if any.
    if (!retval->takes_argument())
      {
        if (equals)
          usage(_("unexpected argument"), this_argv);
        else
          *arg = NULL;
      }
    else
      {
        if (equals)
          *arg = equals + 1;
        else if (retval->takes_optional_argument())
  	*arg = retval->default_value;
        else if (*i < argc && !equals_only)
          *arg = argv[(*i)++];
        else
          usage(_("missing argument"), this_argv);
      }
  
    return retval;
  }
  
  // Parse a short option.  Such options have the form -<option>[arg].
  // If "arg" is not present but the option takes an argument, the next
  // word is taken to the be the argument.  If the option does not take
  // an argument, it may be followed by another short option.  Returns a
  // One_option struct or NULL if argv[i] cannot be parsed as a short
  // option.  In the not-NULL case, *arg is set to the option's argument
  // (NULL if the option takes no argument), and *i is advanced past
  // this option.  This function keeps *i the same if we parsed a short
  // option that does not take an argument, that looks to be followed by
  // another short option in the same word.
  gold::options::One_option*
  parse_short_option(int argc, const char** argv, int pos_in_argv_i,
                     const char** arg, int* i)
  {
    const char* const this_argv = argv[*i];
  
    if (this_argv[0] != '-')
      return NULL;
  
    // We handle -z as a special case.
    static gold::options::One_option dash_z("", gold::options::DASH_Z,
                                            'z', "", NULL, "Z-OPTION", false,
  					  NULL);
    gold::options::One_option* retval = NULL;
    if (this_argv[pos_in_argv_i] == 'z')
      retval = &dash_z;
    else
      {
        const int char_as_int = static_cast<int>(this_argv[pos_in_argv_i]);
        if (char_as_int > 0 && char_as_int < 128)
          retval = gold::options::short_options[char_as_int];
      }
  
    if (retval == NULL)
      return NULL;
  
    // Figure out the option's argument, if any.
    if (!retval->takes_argument())
      {
        *arg = NULL;
        // We only advance past this argument if it's the only one in argv.
        if (this_argv[pos_in_argv_i + 1] == '\0')
          ++(*i);
      }
    else
      {
        // If we take an argument, we'll eat up this entire argv entry.
        ++(*i);
        if (this_argv[pos_in_argv_i + 1] != '\0')
          *arg = this_argv + pos_in_argv_i + 1;
        else if (retval->takes_optional_argument())
  	*arg = retval->default_value;
        else if (*i < argc)
          *arg = argv[(*i)++];
        else
          usage(_("missing argument"), this_argv);
      }
  
    // If we're a -z option, we need to parse our argument as a
    // long-option, e.g. "-z stacksize=8192".
    if (retval == &dash_z)
      {
        int dummy_i = 0;
        const char* dash_z_arg = *arg;
        retval = parse_long_option(1, arg, true, arg, &dummy_i);
        if (retval == NULL)
          usage(_("unknown -z option"), dash_z_arg);
      }
  
    return retval;
  }
  
  } // End anonymous namespace.
  
  namespace gold
  {
  
  General_options::General_options()
    : printed_version_(false),
      execstack_status_(EXECSTACK_FROM_INPUT),
      icf_status_(ICF_NONE),
      static_(false),
      do_demangle_(false),
      plugins_(NULL),
      dynamic_list_(),
      incremental_mode_(INCREMENTAL_OFF),
      incremental_disposition_(INCREMENTAL_STARTUP),
      incremental_startup_disposition_(INCREMENTAL_CHECK),
      implicit_incremental_(false),
      excluded_libs_(),
      symbols_to_retain_(),
      section_starts_(),
      fix_v4bx_(FIX_V4BX_NONE),
      endianness_(ENDIANNESS_NOT_SET)
  {
    // Turn off option registration once construction is complete.
    gold::options::ready_to_register = false;
  }
  
  General_options::Object_format
  General_options::format_enum() const
  {
    return General_options::string_to_object_format(this->format());
  }
  
  General_options::Object_format
  General_options::oformat_enum() const
  {
    return General_options::string_to_object_format(this->oformat());
  }
  
  // Add the sysroot, if any, to the search paths.
  
  void
  General_options::add_sysroot()
  {
    if (this->sysroot() == NULL || this->sysroot()[0] == '\0')
      {
        this->set_sysroot(get_default_sysroot());
        if (this->sysroot() == NULL || this->sysroot()[0] == '\0')
          return;
      }
  
    char* canonical_sysroot = lrealpath(this->sysroot());
  
    for (Dir_list::iterator p = this->library_path_.value.begin();
         p != this->library_path_.value.end();
         ++p)
      p->add_sysroot(this->sysroot(), canonical_sysroot);
  
    free(canonical_sysroot);
  }
  
  // Return whether FILENAME is in a system directory.
  
  bool
  General_options::is_in_system_directory(const std::string& filename) const
  {
    for (Dir_list::const_iterator p = this->library_path_.value.begin();
         p != this->library_path_.value.end();
         ++p)
      {
        // We use a straight string comparison rather than calling
        // FILENAME_CMP because we are only interested in the cases
        // where we found the file in a system directory, which means
        // that we used the directory name as a prefix for a -L search.
        if (p->is_system_directory()
  	  && filename.compare(0, p->name().size(), p->name()) == 0)
  	return true;
      }
    return false;
  }
  
  // Add a plugin to the list of plugins.
  
  void
  General_options::add_plugin(const char* filename)
  {
    if (this->plugins_ == NULL)
      this->plugins_ = new Plugin_manager(*this);
    this->plugins_->add_plugin(filename);
  }
  
  // Add a plugin option to a plugin.
  
  void
  General_options::add_plugin_option(const char* arg)
  {
    if (this->plugins_ == NULL)
      gold_fatal("--plugin-opt requires --plugin.");
    this->plugins_->add_plugin_option(arg);
  }
  
  // Set up variables and other state that isn't set up automatically by
  // the parse routine, and ensure options don't contradict each other
  // and are otherwise kosher.
  
  void
  General_options::finalize()
  {
    // Normalize the strip modifiers.  They have a total order:
    // strip_all > strip_debug > strip_non_line > strip_debug_gdb.
    // If one is true, set all beneath it to true as well.
    if (this->strip_all())
      this->set_strip_debug(true);
    if (this->strip_debug())
      this->set_strip_debug_non_line(true);
    if (this->strip_debug_non_line())
      this->set_strip_debug_gdb(true);
  
    if (this->Bshareable())
      this->set_shared(true);
  
    // If the user specifies both -s and -r, convert the -s to -S.
    // -r requires us to keep externally visible symbols!
    if (this->strip_all() && this->relocatable())
      {
        this->set_strip_all(false);
        gold_assert(this->strip_debug());
      }
  
    // For us, -dc and -dp are synonyms for --define-common.
    if (this->dc())
      this->set_define_common(true);
    if (this->dp())
      this->set_define_common(true);
  
    // We also set --define-common if we're not relocatable, as long as
    // the user didn't explicitly ask for something different.
    if (!this->user_set_define_common())
      this->set_define_common(!this->relocatable());
  
    // execstack_status_ is a three-state variable; update it based on
    // -z [no]execstack.
    if (this->execstack())
      this->set_execstack_status(EXECSTACK_YES);
    else if (this->noexecstack())
      this->set_execstack_status(EXECSTACK_NO);
  
    // icf_status_ is a three-state variable; update it based on the
    // value of this->icf().
    if (strcmp(this->icf(), "none") == 0)
      this->set_icf_status(ICF_NONE);
    else if (strcmp(this->icf(), "safe") == 0)
      this->set_icf_status(ICF_SAFE);
    else
      this->set_icf_status(ICF_ALL);
  
    // Handle the optional argument for --demangle.
    if (this->user_set_demangle())
      {
        this->set_do_demangle(true);
        const char* style = this->demangle();
        if (*style != '\0')
  	{
  	  enum demangling_styles style_code;
  
  	  style_code = cplus_demangle_name_to_style(style);
  	  if (style_code == unknown_demangling)
  	    gold_fatal("unknown demangling style '%s'", style);
  	  cplus_demangle_set_style(style_code);
  	}
      }
    else if (this->user_set_no_demangle())
      this->set_do_demangle(false);
    else
      {
        // Testing COLLECT_NO_DEMANGLE makes our default demangling
        // behaviour identical to that of gcc's linker wrapper.
        this->set_do_demangle(getenv("COLLECT_NO_DEMANGLE") == NULL);
      }
  
    // -M is equivalent to "-Map -".
    if (this->print_map() && !this->user_set_Map())
      {
        this->set_Map("-");
        this->set_user_set_Map();
      }
  
    // Using -n or -N implies -static.
    if (this->nmagic() || this->omagic())
      this->set_static(true);
  
    // If --thread_count is specified, it applies to
    // --thread-count-{initial,middle,final}, though it doesn't override
    // them.
    if (this->thread_count() > 0 && this->thread_count_initial() == 0)
      this->set_thread_count_initial(this->thread_count());
    if (this->thread_count() > 0 && this->thread_count_middle() == 0)
      this->set_thread_count_middle(this->thread_count());
    if (this->thread_count() > 0 && this->thread_count_final() == 0)
      this->set_thread_count_final(this->thread_count());
  
    // Let's warn if you set the thread-count but we're going to ignore it.
  #ifndef ENABLE_THREADS
    if (this->threads())
      {
        gold_warning(_("ignoring --threads: "
  		     "%s was compiled without thread support"),
  		   program_name);
        this->set_threads(false);
      }
    if (this->thread_count() > 0 || this->thread_count_initial() > 0
        || this->thread_count_middle() > 0 || this->thread_count_final() > 0)
      gold_warning(_("ignoring --thread-count: "
                     "%s was compiled without thread support"),
                   program_name);
  #endif
  
    if (this->user_set_Y())
      {
        std::string s = this->Y();
        if (s.compare(0, 2, "P,") == 0)
  	s.erase(0, 2);
  
        size_t pos = 0;
        size_t next_pos;
        do
  	{
  	  next_pos = s.find(':', pos);
  	  size_t len = (next_pos == std::string::npos
  			? next_pos
  			: next_pos - pos);
  	  if (len != 0)
  	    this->add_to_library_path_with_sysroot(s.substr(pos, len).c_str());
  	  pos = next_pos + 1;
  	}
        while (next_pos != std::string::npos);
      }
    else if (!this->nostdlib())
      {
        // Even if they don't specify it, we add -L /lib and -L /usr/lib.
        // FIXME: We should only do this when configured in native mode.
        this->add_to_library_path_with_sysroot("/lib");
        this->add_to_library_path_with_sysroot("/usr/lib");
      }
  
    // Parse the contents of -retain-symbols-file into a set.
    if (this->retain_symbols_file())
      {
        std::ifstream in;
        in.open(this->retain_symbols_file());
        if (!in)
          gold_fatal(_("unable to open -retain-symbols-file file %s: %s"),
                     this->retain_symbols_file(), strerror(errno));
        std::string line;
        std::getline(in, line);   // this chops off the trailing \n, if any
        while (in)
          {
            if (!line.empty() && line[line.length() - 1] == '\r')   // Windows
              line.resize(line.length() - 1);
            this->symbols_to_retain_.insert(line);
            std::getline(in, line);
          }
      }
  
    // -Bgroup implies --unresolved-symbols=report-all.
    if (this->Bgroup() && !this->user_set_unresolved_symbols())
      this->set_unresolved_symbols("report-all");
  
    // -shared implies --allow-shlib-undefined.  Currently
    // ---allow-shlib-undefined controls warnings issued based on the
    // -symbol table.  --unresolved-symbols controls warnings issued
    // -based on relocations.
    if (this->shared() && !this->user_set_allow_shlib_undefined())
      this->set_allow_shlib_undefined(true);
  
    // Normalize library_path() by adding the sysroot to all directories
    // in the path, as appropriate.
    this->add_sysroot();
  
    // Now that we've normalized the options, check for contradictory ones.
    if (this->shared() && this->is_static())
      gold_fatal(_("-shared and -static are incompatible"));
    if (this->shared() && this->pie())
      gold_fatal(_("-shared and -pie are incompatible"));
  
    if (this->shared() && this->relocatable())
      gold_fatal(_("-shared and -r are incompatible"));
    if (this->pie() && this->relocatable())
      gold_fatal(_("-pie and -r are incompatible"));
  
    if (!this->shared())
      {
        if (this->filter() != NULL)
  	gold_fatal(_("-F/--filter may not used without -shared"));
        if (this->any_auxiliary())
  	gold_fatal(_("-f/--auxiliary may not be used without -shared"));
      }
  
    // TODO: implement support for -retain-symbols-file with -r, if needed.
    if (this->relocatable() && this->retain_symbols_file())
      gold_fatal(_("-retain-symbols-file does not yet work with -r"));
  
    if (this->oformat_enum() != General_options::OBJECT_FORMAT_ELF
        && (this->shared()
  	  || this->pie()
  	  || this->relocatable()))
      gold_fatal(_("binary output format not compatible "
  		 "with -shared or -pie or -r"));
  
    if (this->user_set_hash_bucket_empty_fraction()
        && (this->hash_bucket_empty_fraction() < 0.0
  	  || this->hash_bucket_empty_fraction() >= 1.0))
      gold_fatal(_("--hash-bucket-empty-fraction value %g out of range "
  		 "[0.0, 1.0)"),
  	       this->hash_bucket_empty_fraction());
  
    if (this->implicit_incremental_ && this->incremental_mode_ == INCREMENTAL_OFF)
      gold_fatal(_("Options --incremental-changed, --incremental-unchanged, "
                   "--incremental-unknown require the use of --incremental"));
  
    // FIXME: we can/should be doing a lot more sanity checking here.
  }
  
  // Search_directory methods.
  
  // This is called if we have a sysroot.  Apply the sysroot if
  // appropriate.  Record whether the directory is in the sysroot.
  
  void
  Search_directory::add_sysroot(const char* sysroot,
                                const char* canonical_sysroot)
  {
    gold_assert(*sysroot != '\0');
    if (this->put_in_sysroot_)
      {
        if (!IS_DIR_SEPARATOR(this->name_[0])
            && !IS_DIR_SEPARATOR(sysroot[strlen(sysroot) - 1]))
          this->name_ = '/' + this->name_;
        this->name_ = sysroot + this->name_;
        this->is_in_sysroot_ = true;
      }
    else
      {
        // Check whether this entry is in the sysroot.  To do this
        // correctly, we need to use canonical names.  Otherwise we will
        // get confused by the ../../.. paths that gcc tends to use.
        char* canonical_name = lrealpath(this->name_.c_str());
        int canonical_name_len = strlen(canonical_name);
        int canonical_sysroot_len = strlen(canonical_sysroot);
        if (canonical_name_len > canonical_sysroot_len
            && IS_DIR_SEPARATOR(canonical_name[canonical_sysroot_len]))
          {
            canonical_name[canonical_sysroot_len] = '\0';
            if (FILENAME_CMP(canonical_name, canonical_sysroot) == 0)
              this->is_in_sysroot_ = true;
          }
        free(canonical_name);
      }
  }
  
  // Input_arguments methods.
  
  // Add a file to the list.
  
  Input_argument&
  Input_arguments::add_file(Input_file_argument& file)
  {
    file.set_arg_serial(++this->file_count_);
    if (this->in_group_)
      {
        gold_assert(!this->input_argument_list_.empty());
        gold_assert(this->input_argument_list_.back().is_group());
        return this->input_argument_list_.back().group()->add_file(file);
      }
    if (this->in_lib_)
      {
        gold_assert(!this->input_argument_list_.empty());
        gold_assert(this->input_argument_list_.back().is_lib());
        return this->input_argument_list_.back().lib()->add_file(file);
      }
    this->input_argument_list_.push_back(Input_argument(file));
    return this->input_argument_list_.back();
  }
  
  // Start a group.
  
  void
  Input_arguments::start_group()
  {
    if (this->in_group_)
      gold_fatal(_("May not nest groups"));
    if (this->in_lib_)
      gold_fatal(_("may not nest groups in libraries"));
    Input_file_group* group = new Input_file_group();
    this->input_argument_list_.push_back(Input_argument(group));
    this->in_group_ = true;
  }
  
  // End a group.
  
  void
  Input_arguments::end_group()
  {
    if (!this->in_group_)
      gold_fatal(_("Group end without group start"));
    this->in_group_ = false;
  }
  
  // Start a lib.
  
  void
  Input_arguments::start_lib(const Position_dependent_options& options)
  {
    if (this->in_lib_)
      gold_fatal(_("may not nest libraries"));
    if (this->in_group_)
      gold_fatal(_("may not nest libraries in groups"));
    Input_file_lib* lib = new Input_file_lib(options);
    this->input_argument_list_.push_back(Input_argument(lib));
    this->in_lib_ = true;
  }
  
  // End a lib.
  
  void
  Input_arguments::end_lib()
  {
    if (!this->in_lib_)
      gold_fatal(_("lib end without lib start"));
    this->in_lib_ = false;
  }
  
  // Command_line options.
  
  Command_line::Command_line()
  {
  }
  
  // Pre_options is the hook that sets the ready_to_register flag.
  
  Command_line::Pre_options::Pre_options()
  {
    gold::options::ready_to_register = true;
  }
  
  // Process the command line options.  For process_one_option, i is the
  // index of argv to process next, and must be an option (that is,
  // start with a dash).  The return value is the index of the next
  // option to process (i+1 or i+2, or argc to indicate processing is
  // done).  no_more_options is set to true if (and when) "--" is seen
  // as an option.
  
  int
  Command_line::process_one_option(int argc, const char** argv, int i,
                                   bool* no_more_options)
  {
    gold_assert(argv[i][0] == '-' && !(*no_more_options));
  
    // If we are reading "--", then just set no_more_options and return.
    if (argv[i][1] == '-' && argv[i][2] == '\0')
      {
        *no_more_options = true;
        return i + 1;
      }
  
    int new_i = i;
    options::One_option* option = NULL;
    const char* arg = NULL;
  
    // First, try to process argv as a long option.
    option = parse_long_option(argc, argv, false, &arg, &new_i);
    if (option)
      {
        option->reader->parse_to_value(argv[i], arg, this, &this->options_);
        return new_i;
      }
  
    // Now, try to process argv as a short option.  Since several short
    // options can be combined in one argv, we may have to parse a lot
    // until we're done reading this argv.
    int pos_in_argv_i = 1;
    while (new_i == i)
      {
        option = parse_short_option(argc, argv, pos_in_argv_i, &arg, &new_i);
        if (!option)
          break;
        option->reader->parse_to_value(argv[i], arg, this, &this->options_);
        ++pos_in_argv_i;
      }
    if (option)
      return new_i;
  
    // I guess it's neither a long option nor a short option.
    usage(_("unknown option"), argv[i]);
    return argc;
  }
  
  
  void
  Command_line::process(int argc, const char** argv)
  {
    bool no_more_options = false;
    int i = 0;
    while (i < argc)
      {
        this->position_options_.copy_from_options(this->options());
        if (no_more_options || argv[i][0] != '-')
          {
  	  Input_file_argument file(argv[i],
  				   Input_file_argument::INPUT_FILE_TYPE_FILE,
  				   "", false, this->position_options_);
            this->inputs_.add_file(file);
            ++i;
          }
        else
          i = process_one_option(argc, argv, i, &no_more_options);
      }
  
    if (this->inputs_.in_group())
      {
        fprintf(stderr, _("%s: missing group end\n"), program_name);
        usage();
      }
  
    // Normalize the options and ensure they don't contradict each other.
    this->options_.finalize();
  }
  
  // Finalize the version script options and return them.
  
  const Version_script_info&
  Command_line::version_script()
  {
    this->options_.finalize_dynamic_list();
    Version_script_info* vsi = this->script_options_.version_script_info();
    vsi->finalize();
    return *vsi;
  }
  
  } // End namespace gold.
  