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 // If the default sysroot is relocatable, try relocating it based on
 224 // the prefix FROM.
 225
 226 char*
 227 get_relative_sysroot(const char* from)
 228 {
 229   char* path = make_relative_prefix(gold::program_name, from,
 230                                     TARGET_SYSTEM_ROOT);
 231   if (path != NULL)
 232     {
 233       struct stat s;
 234       if (::stat(path, &s) == 0 && S_ISDIR(s.st_mode))
 235         return path;
 236       free(path);
 237     }
 238
 239   return NULL;
 240 }
 241
 242 // Return the default sysroot.  This is set by the --with-sysroot
 243 // option to configure.
 244
 245 std::string
 246 get_default_sysroot()
 247 {
 248   const char* sysroot = TARGET_SYSTEM_ROOT;
 249   if (*sysroot == '\0')
 250     return "";
 251
 252   if (TARGET_SYSTEM_ROOT_RELOCATABLE)
 253     {
 254       char* path = get_relative_sysroot (BINDIR);
 255       if (path == NULL)
 256         path = get_relative_sysroot (TOOLBINDIR);
 257       if (path != NULL)
 258         {
 259           std::string ret = path;
 260           free(path);
 261           return ret;
 262         }
 263     }
 264
 265   return sysroot;
 266 }
 267
 268 } // End anonymous namespace.
 269
 270 namespace gold
 271 {
 272
 273 // Helper macros used to specify the options.  We could also do this
 274 // using constructors, but then g++ would generate code to initialize
 275 // the array.  We want the array to be initialized statically so that
 276 // we get better startup time.
 277
 278 #define GENERAL_NOARG(short_option, long_option, doc, help, dash, func) \
 279   { short_option, long_option, doc, help, options::One_option::dash, \
 280       NULL, func, NULL, NULL, NULL }
 281 #define GENERAL_ARG(short_option, long_option, doc, help, dash, func)   \
 282   { short_option, long_option, doc, help, options::One_option::dash, \
 283       NULL, NULL, func, NULL, NULL }
 284 #define POSDEP_NOARG(short_option, long_option, doc, help, dash, func)  \
 285   { short_option, long_option, doc, help, options::One_option::dash, \
 286       NULL,  NULL, NULL, func, NULL }
 287 #define POSDEP_ARG(short_option, long_option, doc, help, dash, func)    \
 288   { short_option, long_option, doc, help, options::One_option::dash, \
 289       NULL, NULL, NULL, NULL, func }
 290 #define SPECIAL(short_option, long_option, doc, help, dash, func)       \
 291   { short_option, long_option, doc, help, options::One_option::dash, \
 292       func, NULL, NULL, NULL, NULL }
 293
 294 // Here is the actual list of options which we accept.
 295
 296 const options::One_option
 297 options::Command_line_options::options[] =
 298 {
 299   SPECIAL('l', "library", N_("Search for library LIBNAME"),
 300           N_("-lLIBNAME, --library LIBNAME"), TWO_DASHES,
 301           &library),
 302   SPECIAL('(', "start-group", N_("Start a library search group"), NULL,
 303           TWO_DASHES, &start_group),
 304   SPECIAL(')', "end-group", N_("End a library search group"), NULL,
 305           TWO_DASHES, &end_group),
 306   GENERAL_NOARG('E', "export-dynamic", N_("Export all dynamic symbols"),
 307                 NULL, TWO_DASHES, &General_options::set_export_dynamic),
 308   GENERAL_ARG('I', "dynamic-linker", N_("Set dynamic linker path"),
 309               N_("-I PROGRAM, --dynamic-linker PROGRAM"), TWO_DASHES,
 310               &General_options::set_dynamic_linker),
 311   GENERAL_ARG('L', "library-path", N_("Add directory to search path"),
 312               N_("-L DIR, --library-path DIR"), TWO_DASHES,
 313               &General_options::add_to_search_path),
 314   GENERAL_ARG('m', NULL, N_("Ignored for compatibility"), NULL, ONE_DASH,
 315               &General_options::ignore),
 316   GENERAL_ARG('O', NULL, N_("Optimize output file size"),
 317               N_("-O level"), ONE_DASH,
 318               &General_options::set_optimization_level),
 319   GENERAL_ARG('o', "output", N_("Set output file name"),
 320               N_("-o FILE, --output FILE"), TWO_DASHES,
 321               &General_options::set_output_file_name),
 322   GENERAL_NOARG('r', NULL, N_("Generate relocatable output"), NULL,
 323                 ONE_DASH, &General_options::set_relocatable),
 324   GENERAL_ARG('R', "rpath", N_("Add DIR to runtime search path"),
 325               N_("-R DIR, -rpath DIR"), ONE_DASH,
 326               &General_options::add_to_rpath),
 327   GENERAL_NOARG('\0', "eh-frame-hdr", N_("Create exception frame header"),
 328                 NULL, TWO_DASHES, &General_options::set_create_eh_frame_hdr),
 329   GENERAL_ARG('\0', "rpath-link",
 330               N_("Add DIR to link time shared library search path"),
 331               N_("--rpath-link DIR"), TWO_DASHES,
 332               &General_options::add_to_rpath_link),
 333   GENERAL_NOARG('\0', "shared", N_("Generate shared library"),
 334                 NULL, ONE_DASH, &General_options::set_shared),
 335   GENERAL_NOARG('\0', "static", N_("Do not link against shared libraries"),
 336                 NULL, ONE_DASH, &General_options::set_static),
 337   GENERAL_ARG('\0', "sysroot", N_("Set target system root directory"),
 338               N_("--sysroot DIR"), TWO_DASHES, &General_options::set_sysroot),
 339   POSDEP_NOARG('\0', "as-needed",
 340                N_("Only set DT_NEEDED for dynamic libs if used"),
 341                NULL, TWO_DASHES, &Position_dependent_options::set_as_needed),
 342   POSDEP_NOARG('\0', "no-as-needed",
 343                N_("Always DT_NEEDED for dynamic libs (default)"),
 344                NULL, TWO_DASHES, &Position_dependent_options::clear_as_needed),
 345   POSDEP_NOARG('\0', "whole-archive",
 346                N_("Include all archive contents"),
 347                NULL, TWO_DASHES,
 348                &Position_dependent_options::set_whole_archive),
 349   POSDEP_NOARG('\0', "no-whole-archive",
 350                N_("Include only needed archive contents"),
 351                NULL, TWO_DASHES,
 352                &Position_dependent_options::clear_whole_archive),
 353   SPECIAL('\0', "help", N_("Report usage information"), NULL,
 354           TWO_DASHES, &help)
 355 };
 356
 357 const int options::Command_line_options::options_size =
 358   sizeof (options) / sizeof (options[0]);
 359
 360 // The default values for the general options.
 361
 362 General_options::General_options()
 363   : export_dynamic_(false),
 364     dynamic_linker_(NULL),
 365     search_path_(),
 366     optimization_level_(0),
 367     output_file_name_("a.out"),
 368     is_relocatable_(false),
 369     create_eh_frame_hdr_(false),
 370     rpath_(),
 371     rpath_link_(),
 372     is_shared_(false),
 373     is_static_(false),
 374     sysroot_()
 375 {
 376 }
 377
 378 // The default values for the position dependent options.
 379
 380 Position_dependent_options::Position_dependent_options()
 381   : do_static_search_(false),
 382     as_needed_(false),
 383     include_whole_archive_(false)
 384 {
 385 }
 386
 387 // Add the sysroot, if any, to the search paths.
 388
 389 void
 390 General_options::add_sysroot()
 391 {
 392   if (this->sysroot_.empty())
 393     {
 394       this->sysroot_ = get_default_sysroot();
 395       if (this->sysroot_.empty())
 396         return;
 397     }
 398
 399   const char* sysroot = this->sysroot_.c_str();
 400   char* canonical_sysroot = lrealpath(sysroot);
 401
 402   for (Dir_list::iterator p = this->search_path_.begin();
 403        p != this->search_path_.end();
 404        ++p)
 405     p->add_sysroot(sysroot, canonical_sysroot);
 406
 407   free(canonical_sysroot);
 408 }
 409
 410 // Search_directory methods.
 411
 412 // This is called if we have a sysroot.  Apply the sysroot if
 413 // appropriate.  Record whether the directory is in the sysroot.
 414
 415 void
 416 Search_directory::add_sysroot(const char* sysroot,
 417                               const char* canonical_sysroot)
 418 {
 419   gold_assert(*sysroot != '\0');
 420   if (this->put_in_sysroot_)
 421     {
 422       if (!IS_DIR_SEPARATOR(this->name_[0])
 423           && !IS_DIR_SEPARATOR(sysroot[strlen(sysroot) - 1]))
 424         this->name_ = '/' + this->name_;
 425       this->name_ = sysroot + this->name_;
 426       this->is_in_sysroot_ = true;
 427     }
 428   else
 429     {
 430       // Check whether this entry is in the sysroot.  To do this
 431       // correctly, we need to use canonical names.  Otherwise we will
 432       // get confused by the ../../.. paths that gcc tends to use.
 433       char* canonical_name = lrealpath(this->name_.c_str());
 434       int canonical_name_len = strlen(canonical_name);
 435       int canonical_sysroot_len = strlen(canonical_sysroot);
 436       if (canonical_name_len > canonical_sysroot_len
 437           && IS_DIR_SEPARATOR(canonical_name[canonical_sysroot_len]))
 438         {
 439           canonical_name[canonical_sysroot_len] = '\0';
 440           if (FILENAME_CMP(canonical_name, canonical_sysroot) == 0)
 441             this->is_in_sysroot_ = true;
 442         }
 443       free(canonical_name);
 444     }
 445 }
 446
 447 // Input_arguments methods.
 448
 449 // Add a file to the list.
 450
 451 void
 452 Input_arguments::add_file(const Input_file_argument& file)
 453 {
 454   if (!this->in_group_)
 455     this->input_argument_list_.push_back(Input_argument(file));
 456   else
 457     {
 458       gold_assert(!this->input_argument_list_.empty());
 459       gold_assert(this->input_argument_list_.back().is_group());
 460       this->input_argument_list_.back().group()->add_file(file);
 461     }
 462 }
 463
 464 // Start a group.
 465
 466 void
 467 Input_arguments::start_group()
 468 {
 469   gold_assert(!this->in_group_);
 470   Input_file_group* group = new Input_file_group();
 471   this->input_argument_list_.push_back(Input_argument(group));
 472   this->in_group_ = true;
 473 }
 474
 475 // End a group.
 476
 477 void
 478 Input_arguments::end_group()
 479 {
 480   gold_assert(this->in_group_);
 481   this->in_group_ = false;
 482 }
 483
 484 // Command_line options.
 485
 486 Command_line::Command_line()
 487   : options_(), position_options_(), inputs_()
 488 {
 489 }
 490
 491 // Process the command line options.
 492
 493 void
 494 Command_line::process(int argc, char** argv)
 495 {
 496   const int options_size = options::Command_line_options::options_size;
 497   const options::One_option* options =
 498     options::Command_line_options::options;
 499   bool no_more_options = false;
 500   int i = 0;
 501   while (i < argc)
 502     {
 503       if (argv[i][0] != '-' || no_more_options)
 504         {
 505           this->add_file(argv[i], false);
 506           ++i;
 507           continue;
 508         }
 509
 510       // Option starting with '-'.
 511       int dashes = 1;
 512       if (argv[i][1] == '-')
 513         {
 514           dashes = 2;
 515           if (argv[i][2] == '\0')
 516             {
 517               no_more_options = true;
 518               continue;
 519             }
 520         }
 521
 522       // Look for a long option match.
 523       char* opt = argv[i] + dashes;
 524       char first = opt[0];
 525       int skiparg = 0;
 526       char* arg = strchr(opt, '=');
 527       bool argument_with_equals = arg != NULL;
 528       if (arg != NULL)
 529         {
 530           *arg = '\0';
 531           ++arg;
 532         }
 533       else if (i + 1 < argc)
 534         {
 535           arg = argv[i + 1];
 536           skiparg = 1;
 537         }
 538
 539       int j;
 540       for (j = 0; j < options_size; ++j)
 541         {
 542           if (options[j].long_option != NULL
 543               && (dashes == 2
 544                   || (options[j].dash
 545                       != options::One_option::EXACTLY_TWO_DASHES))
 546               && first == options[j].long_option[0]
 547               && strcmp(opt, options[j].long_option) == 0)
 548             {
 549               if (options[j].special)
 550                 i += options[j].special(argc - 1, argv + i, opt, this);
 551               else
 552                 {
 553                   if (!options[j].takes_argument())
 554                     {
 555                       if (argument_with_equals)
 556                         this->usage(_("unexpected argument"), argv[i]);
 557                       arg = NULL;
 558                       skiparg = 0;
 559                     }
 560                   else
 561                     {
 562                       if (arg == NULL)
 563                         this->usage(_("missing argument"), argv[i]);
 564                     }
 565                   this->apply_option(options[j], arg);
 566                   i += skiparg + 1;
 567                 }
 568               break;
 569             }
 570         }
 571       if (j < options_size)
 572         continue;
 573
 574       // If we saw two dashes, we need to see a long option.
 575       if (dashes == 2)
 576         this->usage(_("unknown option"), argv[i]);
 577
 578       // Look for a short option match.  There may be more than one
 579       // short option in a given argument.
 580       bool done = false;
 581       char* s = argv[i] + 1;
 582       ++i;
 583       while (*s != '\0' && !done)
 584         {
 585           char opt = *s;
 586           int j;
 587           for (j = 0; j < options_size; ++j)
 588             {
 589               if (options[j].short_option == opt)
 590                 {
 591                   if (options[j].special)
 592                     {
 593                       // Undo the argument skip done above.
 594                       --i;
 595                       i += options[j].special(argc - i, argv + i, s, this);
 596                       done = true;
 597                     }
 598                   else
 599                     {
 600                       arg = NULL;
 601                       if (options[j].takes_argument())
 602                         {
 603                           if (s[1] != '\0')
 604                             {
 605                               arg = s + 1;
 606                               done = true;
 607                             }
 608                           else if (i < argc)
 609                             {
 610                               arg = argv[i];
 611                               ++i;
 612                             }
 613                           else
 614                             this->usage(_("missing argument"), opt);
 615                         }
 616                       this->apply_option(options[j], arg);
 617                     }
 618                   break;
 619                 }
 620             }
 621
 622           if (j >= options_size)
 623             this->usage(_("unknown option"), *s);
 624
 625           ++s;
 626         }
 627     }
 628
 629   if (this->inputs_.in_group())
 630     {
 631       fprintf(stderr, _("%s: missing group end"), program_name);
 632       this->usage();
 633     }
 634
 635   // FIXME: We should only do this when configured in native mode.
 636   this->options_.add_to_search_path_with_sysroot("/lib");
 637   this->options_.add_to_search_path_with_sysroot("/usr/lib");
 638
 639   this->options_.add_sysroot();
 640 }
 641
 642 // Apply a command line option.
 643
 644 void
 645 Command_line::apply_option(const options::One_option& opt,
 646                            const char* arg)
 647 {
 648   if (arg == NULL)
 649     {
 650       if (opt.general_noarg)
 651         (this->options_.*(opt.general_noarg))();
 652       else if (opt.dependent_noarg)
 653         (this->position_options_.*(opt.dependent_noarg))();
 654       else
 655         gold_unreachable();
 656     }
 657   else
 658     {
 659       if (opt.general_arg)
 660         (this->options_.*(opt.general_arg))(arg);
 661       else if (opt.dependent_arg)
 662         (this->position_options_.*(opt.dependent_arg))(arg);
 663       else
 664         gold_unreachable();
 665     }
 666 }
 667
 668 // Add an input file or library.
 669
 670 void
 671 Command_line::add_file(const char* name, bool is_lib)
 672 {
 673   Input_file_argument file(name, is_lib, "", this->position_options_);
 674   this->inputs_.add_file(file);
 675 }
 676
 677 // Handle the -l option, which requires special treatment.
 678
 679 int
 680 Command_line::process_l_option(int argc, char** argv, char* arg)
 681 {
 682   int ret;
 683   const char* libname;
 684   if (arg[1] != '\0')
 685     {
 686       ret = 1;
 687       libname = arg + 1;
 688     }
 689   else if (argc > 1)
 690     {
 691       ret = 2;
 692       libname = argv[argc + 1];
 693     }
 694   else
 695     this->usage(_("missing argument"), arg);
 696
 697   this->add_file(libname, true);
 698
 699   return ret;
 700 }
 701
 702 // Handle the --start-group option.
 703
 704 void
 705 Command_line::start_group(const char* arg)
 706 {
 707   if (this->inputs_.in_group())
 708     this->usage(_("may not nest groups"), arg);
 709   this->inputs_.start_group();
 710 }
 711
 712 // Handle the --end-group option.
 713
 714 void
 715 Command_line::end_group(const char* arg)
 716 {
 717   if (!this->inputs_.in_group())
 718     this->usage(_("group end without group start"), arg);
 719   this->inputs_.end_group();
 720 }
 721
 722 // Report a usage error.  */
 723
 724 void
 725 Command_line::usage()
 726 {
 727   fprintf(stderr,
 728           _("%s: use the --help option for usage information\n"),
 729           program_name);
 730   gold_exit(false);
 731 }
 732
 733 void
 734 Command_line::usage(const char* msg, const char *opt)
 735 {
 736   fprintf(stderr,
 737           _("%s: %s: %s\n"),
 738           program_name, opt, msg);
 739   this->usage();
 740 }
 741
 742 void
 743 Command_line::usage(const char* msg, char opt)
 744 {
 745   fprintf(stderr,
 746           _("%s: -%c: %s\n"),
 747           program_name, opt, msg);
 748   this->usage();
 749 }
 750
 751 } // End namespace gold.