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   gold::gold_exit(true);
 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   gold::gold_exit(true);
 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_ARG('\0', "sysroot", N_("Set target system root directory"),
 352               N_("--sysroot DIR"), TWO_DASHES, &General_options::set_sysroot),
 353   POSDEP_NOARG('\0', "as-needed",
 354                N_("Only set DT_NEEDED for dynamic libs if used"),
 355                NULL, TWO_DASHES, &Position_dependent_options::set_as_needed),
 356   POSDEP_NOARG('\0', "no-as-needed",
 357                N_("Always DT_NEEDED for dynamic libs (default)"),
 358                NULL, TWO_DASHES, &Position_dependent_options::clear_as_needed),
 359   POSDEP_NOARG('\0', "whole-archive",
 360                N_("Include all archive contents"),
 361                NULL, TWO_DASHES,
 362                &Position_dependent_options::set_whole_archive),
 363   POSDEP_NOARG('\0', "no-whole-archive",
 364                N_("Include only needed archive contents"),
 365                NULL, TWO_DASHES,
 366                &Position_dependent_options::clear_whole_archive),
 367   SPECIAL('\0', "help", N_("Report usage information"), NULL,
 368           TWO_DASHES, &help),
 369   SPECIAL('v', "version", N_("Report version information"), NULL,
 370           TWO_DASHES, &version)
 371 };
 372
 373 const int options::Command_line_options::options_size =
 374   sizeof (options) / sizeof (options[0]);
 375
 376 // The default values for the general options.
 377
 378 General_options::General_options()
 379   : export_dynamic_(false),
 380     dynamic_linker_(NULL),
 381     search_path_(),
 382     optimization_level_(0),
 383     output_file_name_("a.out"),
 384     is_relocatable_(false),
 385     strip_(STRIP_NONE),
 386     create_eh_frame_hdr_(false),
 387     rpath_(),
 388     rpath_link_(),
 389     is_shared_(false),
 390     is_static_(false),
 391     sysroot_()
 392 {
 393 }
 394
 395 // The default values for the position dependent options.
 396
 397 Position_dependent_options::Position_dependent_options()
 398   : do_static_search_(false),
 399     as_needed_(false),
 400     include_whole_archive_(false)
 401 {
 402 }
 403
 404 // Add the sysroot, if any, to the search paths.
 405
 406 void
 407 General_options::add_sysroot()
 408 {
 409   if (this->sysroot_.empty())
 410     {
 411       this->sysroot_ = get_default_sysroot();
 412       if (this->sysroot_.empty())
 413         return;
 414     }
 415
 416   const char* sysroot = this->sysroot_.c_str();
 417   char* canonical_sysroot = lrealpath(sysroot);
 418
 419   for (Dir_list::iterator p = this->search_path_.begin();
 420        p != this->search_path_.end();
 421        ++p)
 422     p->add_sysroot(sysroot, canonical_sysroot);
 423
 424   free(canonical_sysroot);
 425 }
 426
 427 // Search_directory methods.
 428
 429 // This is called if we have a sysroot.  Apply the sysroot if
 430 // appropriate.  Record whether the directory is in the sysroot.
 431
 432 void
 433 Search_directory::add_sysroot(const char* sysroot,
 434                               const char* canonical_sysroot)
 435 {
 436   gold_assert(*sysroot != '\0');
 437   if (this->put_in_sysroot_)
 438     {
 439       if (!IS_DIR_SEPARATOR(this->name_[0])
 440           && !IS_DIR_SEPARATOR(sysroot[strlen(sysroot) - 1]))
 441         this->name_ = '/' + this->name_;
 442       this->name_ = sysroot + this->name_;
 443       this->is_in_sysroot_ = true;
 444     }
 445   else
 446     {
 447       // Check whether this entry is in the sysroot.  To do this
 448       // correctly, we need to use canonical names.  Otherwise we will
 449       // get confused by the ../../.. paths that gcc tends to use.
 450       char* canonical_name = lrealpath(this->name_.c_str());
 451       int canonical_name_len = strlen(canonical_name);
 452       int canonical_sysroot_len = strlen(canonical_sysroot);
 453       if (canonical_name_len > canonical_sysroot_len
 454           && IS_DIR_SEPARATOR(canonical_name[canonical_sysroot_len]))
 455         {
 456           canonical_name[canonical_sysroot_len] = '\0';
 457           if (FILENAME_CMP(canonical_name, canonical_sysroot) == 0)
 458             this->is_in_sysroot_ = true;
 459         }
 460       free(canonical_name);
 461     }
 462 }
 463
 464 // Input_arguments methods.
 465
 466 // Add a file to the list.
 467
 468 void
 469 Input_arguments::add_file(const Input_file_argument& file)
 470 {
 471   if (!this->in_group_)
 472     this->input_argument_list_.push_back(Input_argument(file));
 473   else
 474     {
 475       gold_assert(!this->input_argument_list_.empty());
 476       gold_assert(this->input_argument_list_.back().is_group());
 477       this->input_argument_list_.back().group()->add_file(file);
 478     }
 479 }
 480
 481 // Start a group.
 482
 483 void
 484 Input_arguments::start_group()
 485 {
 486   gold_assert(!this->in_group_);
 487   Input_file_group* group = new Input_file_group();
 488   this->input_argument_list_.push_back(Input_argument(group));
 489   this->in_group_ = true;
 490 }
 491
 492 // End a group.
 493
 494 void
 495 Input_arguments::end_group()
 496 {
 497   gold_assert(this->in_group_);
 498   this->in_group_ = false;
 499 }
 500
 501 // Command_line options.
 502
 503 Command_line::Command_line()
 504   : options_(), position_options_(), inputs_()
 505 {
 506 }
 507
 508 // Process the command line options.
 509
 510 void
 511 Command_line::process(int argc, char** argv)
 512 {
 513   const int options_size = options::Command_line_options::options_size;
 514   const options::One_option* options =
 515     options::Command_line_options::options;
 516   bool no_more_options = false;
 517   int i = 0;
 518   while (i < argc)
 519     {
 520       if (argv[i][0] != '-' || no_more_options)
 521         {
 522           this->add_file(argv[i], false);
 523           ++i;
 524           continue;
 525         }
 526
 527       // Option starting with '-'.
 528       int dashes = 1;
 529       if (argv[i][1] == '-')
 530         {
 531           dashes = 2;
 532           if (argv[i][2] == '\0')
 533             {
 534               no_more_options = true;
 535               continue;
 536             }
 537         }
 538
 539       // Look for a long option match.
 540       char* opt = argv[i] + dashes;
 541       char first = opt[0];
 542       int skiparg = 0;
 543       char* arg = strchr(opt, '=');
 544       bool argument_with_equals = arg != NULL;
 545       if (arg != NULL)
 546         {
 547           *arg = '\0';
 548           ++arg;
 549         }
 550       else if (i + 1 < argc)
 551         {
 552           arg = argv[i + 1];
 553           skiparg = 1;
 554         }
 555
 556       int j;
 557       for (j = 0; j < options_size; ++j)
 558         {
 559           if (options[j].long_option != NULL
 560               && (dashes == 2
 561                   || (options[j].dash
 562                       != options::One_option::EXACTLY_TWO_DASHES))
 563               && first == options[j].long_option[0]
 564               && strcmp(opt, options[j].long_option) == 0)
 565             {
 566               if (options[j].special)
 567                 i += options[j].special(argc - 1, argv + i, opt, this);
 568               else
 569                 {
 570                   if (!options[j].takes_argument())
 571                     {
 572                       if (argument_with_equals)
 573                         this->usage(_("unexpected argument"), argv[i]);
 574                       arg = NULL;
 575                       skiparg = 0;
 576                     }
 577                   else
 578                     {
 579                       if (arg == NULL)
 580                         this->usage(_("missing argument"), argv[i]);
 581                     }
 582                   this->apply_option(options[j], arg);
 583                   i += skiparg + 1;
 584                 }
 585               break;
 586             }
 587         }
 588       if (j < options_size)
 589         continue;
 590
 591       // If we saw two dashes, we need to see a long option.
 592       if (dashes == 2)
 593         this->usage(_("unknown option"), argv[i]);
 594
 595       // Look for a short option match.  There may be more than one
 596       // short option in a given argument.
 597       bool done = false;
 598       char* s = argv[i] + 1;
 599       ++i;
 600       while (*s != '\0' && !done)
 601         {
 602           char opt = *s;
 603           int j;
 604           for (j = 0; j < options_size; ++j)
 605             {
 606               if (options[j].short_option == opt)
 607                 {
 608                   if (options[j].special)
 609                     {
 610                       // Undo the argument skip done above.
 611                       --i;
 612                       i += options[j].special(argc - i, argv + i, s, this);
 613                       done = true;
 614                     }
 615                   else
 616                     {
 617                       arg = NULL;
 618                       if (options[j].takes_argument())
 619                         {
 620                           if (s[1] != '\0')
 621                             {
 622                               arg = s + 1;
 623                               done = true;
 624                             }
 625                           else if (i < argc)
 626                             {
 627                               arg = argv[i];
 628                               ++i;
 629                             }
 630                           else
 631                             this->usage(_("missing argument"), opt);
 632                         }
 633                       this->apply_option(options[j], arg);
 634                     }
 635                   break;
 636                 }
 637             }
 638
 639           if (j >= options_size)
 640             this->usage(_("unknown option"), *s);
 641
 642           ++s;
 643         }
 644     }
 645
 646   if (this->inputs_.in_group())
 647     {
 648       fprintf(stderr, _("%s: missing group end"), program_name);
 649       this->usage();
 650     }
 651
 652   // FIXME: We should only do this when configured in native mode.
 653   this->options_.add_to_search_path_with_sysroot("/lib");
 654   this->options_.add_to_search_path_with_sysroot("/usr/lib");
 655
 656   this->options_.add_sysroot();
 657 }
 658
 659 // Apply a command line option.
 660
 661 void
 662 Command_line::apply_option(const options::One_option& opt,
 663                            const char* arg)
 664 {
 665   if (arg == NULL)
 666     {
 667       if (opt.general_noarg)
 668         (this->options_.*(opt.general_noarg))();
 669       else if (opt.dependent_noarg)
 670         (this->position_options_.*(opt.dependent_noarg))();
 671       else
 672         gold_unreachable();
 673     }
 674   else
 675     {
 676       if (opt.general_arg)
 677         (this->options_.*(opt.general_arg))(arg);
 678       else if (opt.dependent_arg)
 679         (this->position_options_.*(opt.dependent_arg))(arg);
 680       else
 681         gold_unreachable();
 682     }
 683 }
 684
 685 // Add an input file or library.
 686
 687 void
 688 Command_line::add_file(const char* name, bool is_lib)
 689 {
 690   Input_file_argument file(name, is_lib, "", this->position_options_);
 691   this->inputs_.add_file(file);
 692 }
 693
 694 // Handle the -l option, which requires special treatment.
 695
 696 int
 697 Command_line::process_l_option(int argc, char** argv, char* arg)
 698 {
 699   int ret;
 700   const char* libname;
 701   if (arg[1] != '\0')
 702     {
 703       ret = 1;
 704       libname = arg + 1;
 705     }
 706   else if (argc > 1)
 707     {
 708       ret = 2;
 709       libname = argv[argc + 1];
 710     }
 711   else
 712     this->usage(_("missing argument"), arg);
 713
 714   this->add_file(libname, true);
 715
 716   return ret;
 717 }
 718
 719 // Handle the --start-group option.
 720
 721 void
 722 Command_line::start_group(const char* arg)
 723 {
 724   if (this->inputs_.in_group())
 725     this->usage(_("may not nest groups"), arg);
 726   this->inputs_.start_group();
 727 }
 728
 729 // Handle the --end-group option.
 730
 731 void
 732 Command_line::end_group(const char* arg)
 733 {
 734   if (!this->inputs_.in_group())
 735     this->usage(_("group end without group start"), arg);
 736   this->inputs_.end_group();
 737 }
 738
 739 // Report a usage error.  */
 740
 741 void
 742 Command_line::usage()
 743 {
 744   fprintf(stderr,
 745           _("%s: use the --help option for usage information\n"),
 746           program_name);
 747   gold_exit(false);
 748 }
 749
 750 void
 751 Command_line::usage(const char* msg, const char *opt)
 752 {
 753   fprintf(stderr,
 754           _("%s: %s: %s\n"),
 755           program_name, opt, msg);
 756   this->usage();
 757 }
 758
 759 void
 760 Command_line::usage(const char* msg, char opt)
 761 {
 762   fprintf(stderr,
 763           _("%s: -%c: %s\n"),
 764           program_name, opt, msg);
 765   this->usage();
 766 }
 767
 768 } // End namespace gold.