gold/options.cc

   1 // options.c -- handle command line options for gold
   2
   3 // Copyright 2006, 2007 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <iostream>
  26 #include <sys/stat.h>
  27 #include "filenames.h"
  28 #include "libiberty.h"
  29
  30 #include "options.h"
  31
  32 namespace gold
  33 {
  34
  35 // The information we keep for a single command line option.
  36
  37 struct options::One_option
  38 {
  39   // The single character option name, or '\0' if this is only a long
  40   // option.
  41   char short_option;
  42
  43   // The long option name, or NULL if this is only a short option.
  44   const char* long_option;
  45
  46   // Description of the option for --help output, or NULL if there is none.
  47   const char* doc;
  48
  49   // How to print the option name in --help output, or NULL to use the
  50   // default.
  51   const char* help_output;
  52
  53   // Long option dash control.  This is ignored if long_option is
  54   // NULL.
  55   enum
  56     {
  57       // Long option normally takes one dash; two dashes are also
  58       // accepted.
  59       ONE_DASH,
  60       // Long option normally takes two dashes; one dash is also
  61       // accepted.
  62       TWO_DASHES,
  63       // Long option always takes two dashes.
  64       EXACTLY_TWO_DASHES
  65     } dash;
  66
  67   // Function for special handling, or NULL.  Returns the number of
  68   // arguments to skip.  This will normally be at least 1, but it may
  69   // be 0 if this function changes *argv.  ARG points to the location
  70   // in *ARGV where the option starts, which may be helpful for a
  71   // short option.
  72   int (*special)(int argc, char** argv, char *arg, Command_line*);
  73
  74   // If this is a position independent option which does not take an
  75   // argument, this is the member function to call to record it.
  76   void (General_options::*general_noarg)();
  77
  78   // If this is a position independent function which takes an
  79   // argument, this is the member function to call to record it.
  80   void (General_options::*general_arg)(const char*);
  81
  82   // If this is a position dependent option which does not take an
  83   // argument, this is the member function to call to record it.
  84   void (Position_dependent_options::*dependent_noarg)();
  85
  86   // If this is a position dependent option which takes an argument,
  87   // this is the member function to record it.
  88   void (Position_dependent_options::*dependent_arg)(const char*);
  89
  90   // Return whether this option takes an argument.
  91   bool
  92   takes_argument() const
  93   { return this->general_arg != NULL || this->dependent_arg != NULL; }
  94 };
  95
  96 class options::Command_line_options
  97 {
  98  public:
  99   static const One_option options[];
 100   static const int options_size;
 101 };
 102
 103 } // End namespace gold.
 104
 105 namespace
 106 {
 107
 108 // Handle the special -l option, which adds an input file.
 109
 110 int
 111 library(int argc, char** argv, char* arg, gold::Command_line* cmdline)
 112 {
 113   return cmdline->process_l_option(argc, argv, arg);
 114 }
 115
 116 // Handle the special --start-group option.
 117
 118 int
 119 start_group(int, char**, char* arg, gold::Command_line* cmdline)
 120 {
 121   cmdline->start_group(arg);
 122   return 1;
 123 }
 124
 125 // Handle the special --end-group option.
 126
 127 int
 128 end_group(int, char**, char* arg, gold::Command_line* cmdline)
 129 {
 130   cmdline->end_group(arg);
 131   return 1;
 132 }
 133
 134 // Report usage information for ld --help, and exit.
 135
 136 int
 137 help(int, char**, char*, gold::Command_line*)
 138 {
 139   printf(_("Usage: %s [options] file...\nOptions:\n"), gold::program_name);
 140
 141   const int options_size = gold::options::Command_line_options::options_size;
 142   const gold::options::One_option* options =
 143     gold::options::Command_line_options::options;
 144   for (int i = 0; i < options_size; ++i)
 145     {
 146       if (options[i].doc == NULL)
 147         continue;
 148
 149       printf("  ");
 150       int len = 2;
 151       bool comma = false;
 152
 153       int j = i;
 154       do
 155         {
 156           if (options[j].help_output != NULL)
 157             {
 158               if (comma)
 159                 {
 160                   printf(", ");
 161                   len += 2;
 162                 }
 163               printf(options[j].help_output);
 164               len += std::strlen(options[i].help_output);
 165               comma = true;
 166             }
 167           else
 168             {
 169               if (options[j].short_option != '\0')
 170                 {
 171                   if (comma)
 172                     {
 173                       printf(", ");
 174                       len += 2;
 175                     }
 176                   printf("-%c", options[j].short_option);
 177                   len += 2;
 178                   comma = true;
 179                 }
 180
 181               if (options[j].long_option != NULL)
 182                 {
 183                   if (comma)
 184                     {
 185                       printf(", ");
 186                       len += 2;
 187                     }
 188                   if (options[j].dash == gold::options::One_option::ONE_DASH)
 189                     {
 190                       printf("-");
 191                       ++len;
 192                     }
 193                   else
 194                     {
 195                       printf("--");
 196                       len += 2;
 197                     }
 198                   printf("%s", options[j].long_option);
 199                   len += std::strlen(options[j].long_option);
 200                   comma = true;
 201                 }
 202             }
 203           ++j;
 204         }
 205       while (j < options_size && options[j].doc == NULL);
 206
 207       if (len >= 30)
 208         {
 209           printf("\n");
 210           len = 0;
 211         }
 212       for (; len < 30; ++len)
 213         std::putchar(' ');
 214
 215       std::puts(options[i].doc);
 216     }
 217
 218   ::exit(0);
 219
 220   return 0;
 221 }
 222
 223 // Report version information.
 224
 225 int
 226 version(int, char**, char* opt, gold::Command_line*)
 227 {
 228   gold::print_version(opt[0] == 'v' && opt[1] == '\0');
 229   ::exit(0);
 230   return 0;
 231 }
 232
 233 // If the default sysroot is relocatable, try relocating it based on
 234 // the prefix FROM.
 235
 236 char*
 237 get_relative_sysroot(const char* from)
 238 {
 239   char* path = make_relative_prefix(gold::program_name, from,
 240                                     TARGET_SYSTEM_ROOT);
 241   if (path != NULL)
 242     {
 243       struct stat s;
 244       if (::stat(path, &s) == 0 && S_ISDIR(s.st_mode))
 245         return path;
 246       free(path);
 247     }
 248
 249   return NULL;
 250 }
 251
 252 // Return the default sysroot.  This is set by the --with-sysroot
 253 // option to configure.
 254
 255 std::string
 256 get_default_sysroot()
 257 {
 258   const char* sysroot = TARGET_SYSTEM_ROOT;
 259   if (*sysroot == '\0')
 260     return "";
 261
 262   if (TARGET_SYSTEM_ROOT_RELOCATABLE)
 263     {
 264       char* path = get_relative_sysroot (BINDIR);
 265       if (path == NULL)
 266         path = get_relative_sysroot (TOOLBINDIR);
 267       if (path != NULL)
 268         {
 269           std::string ret = path;
 270           free(path);
 271           return ret;
 272         }
 273     }
 274
 275   return sysroot;
 276 }
 277
 278 } // End anonymous namespace.
 279
 280 namespace gold
 281 {
 282
 283 // Helper macros used to specify the options.  We could also do this
 284 // using constructors, but then g++ would generate code to initialize
 285 // the array.  We want the array to be initialized statically so that
 286 // we get better startup time.
 287
 288 #define GENERAL_NOARG(short_option, long_option, doc, help, dash, func) \
 289   { short_option, long_option, doc, help, options::One_option::dash, \
 290       NULL, func, NULL, NULL, NULL }
 291 #define GENERAL_ARG(short_option, long_option, doc, help, dash, func)   \
 292   { short_option, long_option, doc, help, options::One_option::dash, \
 293       NULL, NULL, func, NULL, NULL }
 294 #define POSDEP_NOARG(short_option, long_option, doc, help, dash, func)  \
 295   { short_option, long_option, doc, help, options::One_option::dash, \
 296       NULL,  NULL, NULL, func, NULL }
 297 #define POSDEP_ARG(short_option, long_option, doc, help, dash, func)    \
 298   { short_option, long_option, doc, help, options::One_option::dash, \
 299       NULL, NULL, NULL, NULL, func }
 300 #define SPECIAL(short_option, long_option, doc, help, dash, func)       \
 301   { short_option, long_option, doc, help, options::One_option::dash, \
 302       func, NULL, NULL, NULL, NULL }
 303
 304 // Here is the actual list of options which we accept.
 305
 306 const options::One_option
 307 options::Command_line_options::options[] =
 308 {
 309   SPECIAL('l', "library", N_("Search for library LIBNAME"),
 310           N_("-lLIBNAME, --library LIBNAME"), TWO_DASHES,
 311           &library),
 312   SPECIAL('(', "start-group", N_("Start a library search group"), NULL,
 313           TWO_DASHES, &start_group),
 314   SPECIAL(')', "end-group", N_("End a library search group"), NULL,
 315           TWO_DASHES, &end_group),
 316   GENERAL_NOARG('E', "export-dynamic", N_("Export all dynamic symbols"),
 317                 NULL, TWO_DASHES, &General_options::set_export_dynamic),
 318   GENERAL_ARG('I', "dynamic-linker", N_("Set dynamic linker path"),
 319               N_("-I PROGRAM, --dynamic-linker PROGRAM"), TWO_DASHES,
 320               &General_options::set_dynamic_linker),
 321   GENERAL_ARG('L', "library-path", N_("Add directory to search path"),
 322               N_("-L DIR, --library-path DIR"), TWO_DASHES,
 323               &General_options::add_to_search_path),
 324   GENERAL_ARG('m', NULL, N_("Ignored for compatibility"), NULL, ONE_DASH,
 325               &General_options::ignore),
 326   GENERAL_ARG('O', NULL, N_("Optimize output file size"),
 327               N_("-O level"), ONE_DASH,
 328               &General_options::set_optimization_level),
 329   GENERAL_ARG('o', "output", N_("Set output file name"),
 330               N_("-o FILE, --output FILE"), TWO_DASHES,
 331               &General_options::set_output_file_name),
 332   GENERAL_NOARG('r', NULL, N_("Generate relocatable output"), NULL,
 333                 ONE_DASH, &General_options::set_relocatable),
 334   GENERAL_ARG('R', "rpath", N_("Add DIR to runtime search path"),
 335               N_("-R DIR, -rpath DIR"), ONE_DASH,
 336               &General_options::add_to_rpath),
 337   GENERAL_NOARG('s', "strip-all", N_("Strip all symbols"), NULL,
 338                 TWO_DASHES, &General_options::set_strip_all),
 339   GENERAL_NOARG('S', "strip-debug", N_("Strip debugging information"), NULL,
 340                 TWO_DASHES, &General_options::set_strip_debug),
 341   GENERAL_NOARG('\0', "eh-frame-hdr", N_("Create exception frame header"),
 342                 NULL, TWO_DASHES, &General_options::set_create_eh_frame_hdr),
 343   GENERAL_ARG('\0', "rpath-link",
 344               N_("Add DIR to link time shared library search path"),
 345               N_("--rpath-link DIR"), TWO_DASHES,
 346               &General_options::add_to_rpath_link),
 347   GENERAL_NOARG('\0', "shared", N_("Generate shared library"),
 348                 NULL, ONE_DASH, &General_options::set_shared),
 349   GENERAL_NOARG('\0', "static", N_("Do not link against shared libraries"),
 350                 NULL, ONE_DASH, &General_options::set_static),
 351   GENERAL_NOARG('\0', "stats", N_("Print resource usage statistics"),
 352                 NULL, TWO_DASHES, &General_options::set_stats),
 353   GENERAL_ARG('\0', "sysroot", N_("Set target system root directory"),
 354               N_("--sysroot DIR"), TWO_DASHES, &General_options::set_sysroot),
 355   POSDEP_NOARG('\0', "as-needed",
 356                N_("Only set DT_NEEDED for dynamic libs if used"),
 357                NULL, TWO_DASHES, &Position_dependent_options::set_as_needed),
 358   POSDEP_NOARG('\0', "no-as-needed",
 359                N_("Always DT_NEEDED for dynamic libs (default)"),
 360                NULL, TWO_DASHES, &Position_dependent_options::clear_as_needed),
 361   POSDEP_NOARG('\0', "whole-archive",
 362                N_("Include all archive contents"),
 363                NULL, TWO_DASHES,
 364                &Position_dependent_options::set_whole_archive),
 365   POSDEP_NOARG('\0', "no-whole-archive",
 366                N_("Include only needed archive contents"),
 367                NULL, TWO_DASHES,
 368                &Position_dependent_options::clear_whole_archive),
 369   SPECIAL('\0', "help", N_("Report usage information"), NULL,
 370           TWO_DASHES, &help),
 371   SPECIAL('v', "version", N_("Report version information"), NULL,
 372           TWO_DASHES, &version)
 373 };
 374
 375 const int options::Command_line_options::options_size =
 376   sizeof (options) / sizeof (options[0]);
 377
 378 // The default values for the general options.
 379
 380 General_options::General_options()
 381   : export_dynamic_(false),
 382     dynamic_linker_(NULL),
 383     search_path_(),
 384     optimization_level_(0),
 385     output_file_name_("a.out"),
 386     is_relocatable_(false),
 387     strip_(STRIP_NONE),
 388     create_eh_frame_hdr_(false),
 389     rpath_(),
 390     rpath_link_(),
 391     is_shared_(false),
 392     is_static_(false),
 393     print_stats_(false),
 394     sysroot_()
 395 {
 396 }
 397
 398 // The default values for the position dependent options.
 399
 400 Position_dependent_options::Position_dependent_options()
 401   : do_static_search_(false),
 402     as_needed_(false),
 403     include_whole_archive_(false)
 404 {
 405 }
 406
 407 // Add the sysroot, if any, to the search paths.
 408
 409 void
 410 General_options::add_sysroot()
 411 {
 412   if (this->sysroot_.empty())
 413     {
 414       this->sysroot_ = get_default_sysroot();
 415       if (this->sysroot_.empty())
 416         return;
 417     }
 418
 419   const char* sysroot = this->sysroot_.c_str();
 420   char* canonical_sysroot = lrealpath(sysroot);
 421
 422   for (Dir_list::iterator p = this->search_path_.begin();
 423        p != this->search_path_.end();
 424        ++p)
 425     p->add_sysroot(sysroot, canonical_sysroot);
 426
 427   free(canonical_sysroot);
 428 }
 429
 430 // Search_directory methods.
 431
 432 // This is called if we have a sysroot.  Apply the sysroot if
 433 // appropriate.  Record whether the directory is in the sysroot.
 434
 435 void
 436 Search_directory::add_sysroot(const char* sysroot,
 437                               const char* canonical_sysroot)
 438 {
 439   gold_assert(*sysroot != '\0');
 440   if (this->put_in_sysroot_)
 441     {
 442       if (!IS_DIR_SEPARATOR(this->name_[0])
 443           && !IS_DIR_SEPARATOR(sysroot[strlen(sysroot) - 1]))
 444         this->name_ = '/' + this->name_;
 445       this->name_ = sysroot + this->name_;
 446       this->is_in_sysroot_ = true;
 447     }
 448   else
 449     {
 450       // Check whether this entry is in the sysroot.  To do this
 451       // correctly, we need to use canonical names.  Otherwise we will
 452       // get confused by the ../../.. paths that gcc tends to use.
 453       char* canonical_name = lrealpath(this->name_.c_str());
 454       int canonical_name_len = strlen(canonical_name);
 455       int canonical_sysroot_len = strlen(canonical_sysroot);
 456       if (canonical_name_len > canonical_sysroot_len
 457           && IS_DIR_SEPARATOR(canonical_name[canonical_sysroot_len]))
 458         {
 459           canonical_name[canonical_sysroot_len] = '\0';
 460           if (FILENAME_CMP(canonical_name, canonical_sysroot) == 0)
 461             this->is_in_sysroot_ = true;
 462         }
 463       free(canonical_name);
 464     }
 465 }
 466
 467 // Input_arguments methods.
 468
 469 // Add a file to the list.
 470
 471 void
 472 Input_arguments::add_file(const Input_file_argument& file)
 473 {
 474   if (!this->in_group_)
 475     this->input_argument_list_.push_back(Input_argument(file));
 476   else
 477     {
 478       gold_assert(!this->input_argument_list_.empty());
 479       gold_assert(this->input_argument_list_.back().is_group());
 480       this->input_argument_list_.back().group()->add_file(file);
 481     }
 482 }
 483
 484 // Start a group.
 485
 486 void
 487 Input_arguments::start_group()
 488 {
 489   gold_assert(!this->in_group_);
 490   Input_file_group* group = new Input_file_group();
 491   this->input_argument_list_.push_back(Input_argument(group));
 492   this->in_group_ = true;
 493 }
 494
 495 // End a group.
 496
 497 void
 498 Input_arguments::end_group()
 499 {
 500   gold_assert(this->in_group_);
 501   this->in_group_ = false;
 502 }
 503
 504 // Command_line options.
 505
 506 Command_line::Command_line()
 507   : options_(), position_options_(), inputs_()
 508 {
 509 }
 510
 511 // Process the command line options.
 512
 513 void
 514 Command_line::process(int argc, char** argv)
 515 {
 516   const int options_size = options::Command_line_options::options_size;
 517   const options::One_option* options =
 518     options::Command_line_options::options;
 519   bool no_more_options = false;
 520   int i = 0;
 521   while (i < argc)
 522     {
 523       if (argv[i][0] != '-' || no_more_options)
 524         {
 525           this->add_file(argv[i], false);
 526           ++i;
 527           continue;
 528         }
 529
 530       // Option starting with '-'.
 531       int dashes = 1;
 532       if (argv[i][1] == '-')
 533         {
 534           dashes = 2;
 535           if (argv[i][2] == '\0')
 536             {
 537               no_more_options = true;
 538               continue;
 539             }
 540         }
 541
 542       // Look for a long option match.
 543       char* opt = argv[i] + dashes;
 544       char first = opt[0];
 545       int skiparg = 0;
 546       char* arg = strchr(opt, '=');
 547       bool argument_with_equals = arg != NULL;
 548       if (arg != NULL)
 549         {
 550           *arg = '\0';
 551           ++arg;
 552         }
 553       else if (i + 1 < argc)
 554         {
 555           arg = argv[i + 1];
 556           skiparg = 1;
 557         }
 558
 559       int j;
 560       for (j = 0; j < options_size; ++j)
 561         {
 562           if (options[j].long_option != NULL
 563               && (dashes == 2
 564                   || (options[j].dash
 565                       != options::One_option::EXACTLY_TWO_DASHES))
 566               && first == options[j].long_option[0]
 567               && strcmp(opt, options[j].long_option) == 0)
 568             {
 569               if (options[j].special)
 570                 i += options[j].special(argc - 1, argv + i, opt, this);
 571               else
 572                 {
 573                   if (!options[j].takes_argument())
 574                     {
 575                       if (argument_with_equals)
 576                         this->usage(_("unexpected argument"), argv[i]);
 577                       arg = NULL;
 578                       skiparg = 0;
 579                     }
 580                   else
 581                     {
 582                       if (arg == NULL)
 583                         this->usage(_("missing argument"), argv[i]);
 584                     }
 585                   this->apply_option(options[j], arg);
 586                   i += skiparg + 1;
 587                 }
 588               break;
 589             }
 590         }
 591       if (j < options_size)
 592         continue;
 593
 594       // If we saw two dashes, we need to see a long option.
 595       if (dashes == 2)
 596         this->usage(_("unknown option"), argv[i]);
 597
 598       // Look for a short option match.  There may be more than one
 599       // short option in a given argument.
 600       bool done = false;
 601       char* s = argv[i] + 1;
 602       ++i;
 603       while (*s != '\0' && !done)
 604         {
 605           char opt = *s;
 606           int j;
 607           for (j = 0; j < options_size; ++j)
 608             {
 609               if (options[j].short_option == opt)
 610                 {
 611                   if (options[j].special)
 612                     {
 613                       // Undo the argument skip done above.
 614                       --i;
 615                       i += options[j].special(argc - i, argv + i, s, this);
 616                       done = true;
 617                     }
 618                   else
 619                     {
 620                       arg = NULL;
 621                       if (options[j].takes_argument())
 622                         {
 623                           if (s[1] != '\0')
 624                             {
 625                               arg = s + 1;
 626                               done = true;
 627                             }
 628                           else if (i < argc)
 629                             {
 630                               arg = argv[i];
 631                               ++i;
 632                             }
 633                           else
 634                             this->usage(_("missing argument"), opt);
 635                         }
 636                       this->apply_option(options[j], arg);
 637                     }
 638                   break;
 639                 }
 640             }
 641
 642           if (j >= options_size)
 643             this->usage(_("unknown option"), *s);
 644
 645           ++s;
 646         }
 647     }
 648
 649   if (this->inputs_.in_group())
 650     {
 651       fprintf(stderr, _("%s: missing group end"), program_name);
 652       this->usage();
 653     }
 654
 655   // FIXME: We should only do this when configured in native mode.
 656   this->options_.add_to_search_path_with_sysroot("/lib");
 657   this->options_.add_to_search_path_with_sysroot("/usr/lib");
 658
 659   this->options_.add_sysroot();
 660
 661   // Ensure options don't contradict each other and are otherwise kosher.
 662   this->normalize_options();
 663 }
 664
 665 // Ensure options don't contradict each other and are otherwise kosher.
 666
 667 void
 668 Command_line::normalize_options()
 669 {
 670   // If the user specifies both -s and -r, convert the -s as -S.
 671   // -r requires us to keep externally visible symbols!
 672   if (this->options_.strip_all() && this->options_.is_relocatable())
 673     {
 674       // Clears the strip_all() status, replacing it with strip_debug().
 675       this->options_.set_strip_debug();
 676     }
 677
 678   // FIXME: we can/should be doing a lot more sanity checking here.
 679 }
 680
 681
 682 // Apply a command line option.
 683
 684 void
 685 Command_line::apply_option(const options::One_option& opt,
 686                            const char* arg)
 687 {
 688   if (arg == NULL)
 689     {
 690       if (opt.general_noarg)
 691         (this->options_.*(opt.general_noarg))();
 692       else if (opt.dependent_noarg)
 693         (this->position_options_.*(opt.dependent_noarg))();
 694       else
 695         gold_unreachable();
 696     }
 697   else
 698     {
 699       if (opt.general_arg)
 700         (this->options_.*(opt.general_arg))(arg);
 701       else if (opt.dependent_arg)
 702         (this->position_options_.*(opt.dependent_arg))(arg);
 703       else
 704         gold_unreachable();
 705     }
 706 }
 707
 708 // Add an input file or library.
 709
 710 void
 711 Command_line::add_file(const char* name, bool is_lib)
 712 {
 713   Input_file_argument file(name, is_lib, "", this->position_options_);
 714   this->inputs_.add_file(file);
 715 }
 716
 717 // Handle the -l option, which requires special treatment.
 718
 719 int
 720 Command_line::process_l_option(int argc, char** argv, char* arg)
 721 {
 722   int ret;
 723   const char* libname;
 724   if (arg[1] != '\0')
 725     {
 726       ret = 1;
 727       libname = arg + 1;
 728     }
 729   else if (argc > 1)
 730     {
 731       ret = 2;
 732       libname = argv[argc + 1];
 733     }
 734   else
 735     this->usage(_("missing argument"), arg);
 736
 737   this->add_file(libname, true);
 738
 739   return ret;
 740 }
 741
 742 // Handle the --start-group option.
 743
 744 void
 745 Command_line::start_group(const char* arg)
 746 {
 747   if (this->inputs_.in_group())
 748     this->usage(_("may not nest groups"), arg);
 749   this->inputs_.start_group();
 750 }
 751
 752 // Handle the --end-group option.
 753
 754 void
 755 Command_line::end_group(const char* arg)
 756 {
 757   if (!this->inputs_.in_group())
 758     this->usage(_("group end without group start"), arg);
 759   this->inputs_.end_group();
 760 }
 761
 762 // Report a usage error.  */
 763
 764 void
 765 Command_line::usage()
 766 {
 767   fprintf(stderr,
 768           _("%s: use the --help option for usage information\n"),
 769           program_name);
 770   ::exit(1);
 771 }
 772
 773 void
 774 Command_line::usage(const char* msg, const char *opt)
 775 {
 776   fprintf(stderr,
 777           _("%s: %s: %s\n"),
 778           program_name, opt, msg);
 779   this->usage();
 780 }
 781
 782 void
 783 Command_line::usage(const char* msg, char opt)
 784 {
 785   fprintf(stderr,
 786           _("%s: -%c: %s\n"),
 787           program_name, opt, msg);
 788   this->usage();
 789 }
 790
 791 } // End namespace gold.