gold/options.cc

   1 // options.c -- handle command line options for gold
   2
   3 #include <iostream>
   4
   5 #include "gold.h"
   6 #include "options.h"
   7
   8 namespace gold
   9 {
  10
  11 // The information we keep for a single command line option.
  12
  13 struct options::One_option
  14 {
  15   // The single character option name, or '\0' if this is only a long
  16   // option.
  17   char short_option;
  18
  19   // The long option name, or NULL if this is only a short option.
  20   const char* long_option;
  21
  22   // Description of the option for --help output, or NULL if there is none.
  23   const char* doc;
  24
  25   // How to print the option name in --help output, or NULL to use the
  26   // default.
  27   const char* help_output;
  28
  29   // Long option dash control.  This is ignored if long_option is
  30   // NULL.
  31   enum
  32     {
  33       // Long option normally takes one dash; two dashes are also
  34       // accepted.
  35       ONE_DASH,
  36       // Long option normally takes two dashes; one dash is also
  37       // accepted.
  38       TWO_DASHES,
  39       // Long option always takes two dashes.
  40       EXACTLY_TWO_DASHES
  41     } dash;
  42
  43   // Function for special handling, or NULL.  Returns the number of
  44   // arguments to skip.  This will normally be at least 1, but it may
  45   // be 0 if this function changes *argv.  ARG points to the location
  46   // in *ARGV where the option starts, which may be helpful for a
  47   // short option.
  48   int (*special)(int argc, char** argv, char *arg, Command_line*);
  49
  50   // If this is a position independent option which does not take an
  51   // argument, this is the member function to call to record it.
  52   void (General_options::*general_noarg)();
  53
  54   // If this is a position independent function which takes an
  55   // argument, this is the member function to call to record it.
  56   void (General_options::*general_arg)(const char*);
  57
  58   // If this is a position dependent option which does not take an
  59   // argument, this is the member function to call to record it.
  60   void (Position_dependent_options::*dependent_noarg)();
  61
  62   // If this is a position dependent option which takes an argument,
  63   // this is the member function to record it.
  64   void (Position_dependent_options::*dependent_arg)(const char*);
  65
  66   // Return whether this option takes an argument.
  67   bool
  68   takes_argument() const
  69   { return this->general_arg != NULL || this->dependent_arg != NULL; }
  70 };
  71
  72 class options::Command_line_options
  73 {
  74  public:
  75   static const One_option options[];
  76   static const int options_size;
  77 };
  78
  79 } // End namespace gold.
  80
  81 namespace
  82 {
  83
  84 // Handle the special -l option, which adds an input file.
  85
  86 int
  87 library(int argc, char** argv, char* arg, gold::Command_line* cmdline)
  88 {
  89   return cmdline->process_l_option(argc, argv, arg);
  90 }
  91
  92 // Handle the special --start-group option.
  93
  94 int
  95 start_group(int, char**, char* arg, gold::Command_line* cmdline)
  96 {
  97   cmdline->start_group(arg);
  98   return 1;
  99 }
 100
 101 // Handle the special --end-group option.
 102
 103 int
 104 end_group(int, char**, char* arg, gold::Command_line* cmdline)
 105 {
 106   cmdline->end_group(arg);
 107   return 1;
 108 }
 109
 110 // Report usage information for ld --help, and exit.
 111
 112 int
 113 help(int, char**, char*, gold::Command_line*)
 114 {
 115   printf(_("Usage: %s [options] file...\nOptions:\n"), gold::program_name);
 116
 117   const int options_size = gold::options::Command_line_options::options_size;
 118   const gold::options::One_option* options =
 119     gold::options::Command_line_options::options;
 120   for (int i = 0; i < options_size; ++i)
 121     {
 122       if (options[i].doc == NULL)
 123         continue;
 124
 125       printf("  ");
 126       int len = 2;
 127       bool comma = false;
 128
 129       int j = i;
 130       do
 131         {
 132           if (options[j].help_output != NULL)
 133             {
 134               if (comma)
 135                 {
 136                   printf(", ");
 137                   len += 2;
 138                 }
 139               printf(options[j].help_output);
 140               len += std::strlen(options[i].help_output);
 141             }
 142           else
 143             {
 144               if (options[j].short_option != '\0')
 145                 {
 146                   if (comma)
 147                     {
 148                       printf(", ");
 149                       len += 2;
 150                     }
 151                   printf("-%c", options[j].short_option);
 152                   len += 2;
 153                 }
 154
 155               if (options[j].long_option != NULL)
 156                 {
 157                   if (comma)
 158                     {
 159                       printf(", ");
 160                       len += 2;
 161                     }
 162                   if (options[j].dash == gold::options::One_option::ONE_DASH)
 163                     {
 164                       printf("-");
 165                       ++len;
 166                     }
 167                   else
 168                     {
 169                       printf("--");
 170                       len += 2;
 171                     }
 172                   printf("%s", options[j].long_option);
 173                   len += std::strlen(options[j].long_option);
 174                 }
 175             }
 176           ++j;
 177         }
 178       while (j < options_size && options[j].doc == NULL);
 179
 180       if (len > 30)
 181         {
 182           printf("\n");
 183           len = 0;
 184         }
 185       for (; len < 30; ++len)
 186         std::putchar(' ');
 187
 188       std::puts(options[i].doc);
 189     }
 190
 191   gold::gold_exit(true);
 192
 193   return 0;
 194 }
 195
 196 } // End anonymous namespace.
 197
 198 namespace gold
 199 {
 200
 201 // Helper macros used to specify the options.  We could also do this
 202 // using constructors, but then g++ would generate code to initialize
 203 // the array.  We want the array to be initialized statically so that
 204 // we get better startup time.
 205
 206 #define GENERAL_NOARG(short_option, long_option, doc, help, dash, func) \
 207   { short_option, long_option, doc, help, options::One_option::dash, \
 208       NULL, func, NULL, NULL, NULL }
 209 #define GENERAL_ARG(short_option, long_option, doc, help, dash, func)   \
 210   { short_option, long_option, doc, help, options::One_option::dash, \
 211       NULL, NULL, func, NULL, NULL }
 212 #define POSDEP_NOARG(short_option, long_option, doc, help, dash, func)  \
 213   { short_option, long_option, doc, help, options::One_option::dash, \
 214       NULL,  NULL, NULL, func, NULL }
 215 #define POSDEP_ARG(short_option, long_option, doc, help, dash, func)    \
 216   { short_option, long_option, doc, help, options::One_option::dash, \
 217       NULL, NULL, NULL, NULL, func }
 218 #define SPECIAL(short_option, long_option, doc, help, dash, func)       \
 219   { short_option, long_option, doc, help, options::One_option::dash, \
 220       func, NULL, NULL, NULL, NULL }
 221
 222 // Here is the actual list of options which we accept.
 223
 224 const options::One_option
 225 options::Command_line_options::options[] =
 226 {
 227   SPECIAL('l', "library", N_("Search for library LIBNAME"),
 228           N_("-lLIBNAME --library LIBNAME"), TWO_DASHES,
 229           &library),
 230   SPECIAL('(', "start-group", N_("Start a library search group"), NULL,
 231           TWO_DASHES, &start_group),
 232   SPECIAL(')', "end-group", N_("End a library search group"), NULL,
 233           TWO_DASHES, &end_group),
 234   GENERAL_ARG('L', "library-path", N_("Add directory to search path"),
 235               N_("-L DIR, --library-path DIR"), TWO_DASHES,
 236               &General_options::add_to_search_path),
 237   GENERAL_ARG('o', "output", N_("Set output file name"),
 238               N_("-o FILE, --output FILE"), TWO_DASHES,
 239               &General_options::set_output_file_name),
 240   GENERAL_NOARG('r', NULL, N_("Generate relocatable output"), NULL,
 241                 ONE_DASH, &General_options::set_relocatable),
 242   GENERAL_NOARG('\0', "shared", N_("Generate shared library"),
 243                 NULL, ONE_DASH, &General_options::set_shared),
 244   GENERAL_NOARG('\0', "static", N_("Do not link against shared libraries"),
 245                 NULL, ONE_DASH, &General_options::set_static),
 246   SPECIAL('\0', "help", N_("Report usage information"), NULL,
 247           TWO_DASHES, &help)
 248 };
 249
 250 const int options::Command_line_options::options_size =
 251   sizeof (options) / sizeof (options[0]);
 252
 253 // The default values for the general options.
 254
 255 General_options::General_options()
 256   : search_path_(),
 257     output_file_name_("a.out"),
 258     is_relocatable_(false),
 259     is_shared_(false),
 260     is_static_(false)
 261 {
 262 }
 263
 264 // The default values for the position dependent options.
 265
 266 Position_dependent_options::Position_dependent_options()
 267   : do_static_search_(false)
 268 {
 269 }
 270
 271 // Command_line options.
 272
 273 Command_line::Command_line()
 274   : options_(), position_options_(), inputs_(), in_group_(false)
 275 {
 276 }
 277
 278 // Process the command line options.
 279
 280 void
 281 Command_line::process(int argc, char** argv)
 282 {
 283   const int options_size = options::Command_line_options::options_size;
 284   const options::One_option* options =
 285     options::Command_line_options::options;
 286   bool no_more_options = false;
 287   int i = 0;
 288   while (i < argc)
 289     {
 290       if (argv[i][0] != '-' || no_more_options)
 291         {
 292           this->add_file(argv[i], false);
 293           ++i;
 294           continue;
 295         }
 296
 297       // Option starting with '-'.
 298       int dashes = 1;
 299       if (argv[i][1] == '-')
 300         {
 301           dashes = 2;
 302           if (argv[i][2] == '\0')
 303             {
 304               no_more_options = true;
 305               continue;
 306             }
 307         }
 308
 309       // Look for a long option match.
 310       char* opt = argv[i] + dashes;
 311       char first = opt[0];
 312       int skiparg = 0;
 313       char* arg = strchr(opt, '=');
 314       if (arg != NULL)
 315         *arg = '\0';
 316       else if (i + 1 < argc)
 317         {
 318           arg = argv[i + 1];
 319           skiparg = 1;
 320         }
 321
 322       int j;
 323       for (j = 0; j < options_size; ++j)
 324         {
 325           if (options[j].long_option != NULL
 326               && (dashes == 2
 327                   || (options[j].dash
 328                       != options::One_option::EXACTLY_TWO_DASHES))
 329               && first == options[j].long_option[0]
 330               && strcmp(opt, options[j].long_option) == 0)
 331             {
 332               if (options[j].special)
 333                 i += options[j].special(argc - 1, argv + i, opt, this);
 334               else
 335                 {
 336                   if (!options[j].takes_argument())
 337                     {
 338                       arg = NULL;
 339                       skiparg = 0;
 340                     }
 341                   else
 342                     {
 343                       if (arg == NULL)
 344                         this->usage(_("missing argument"), argv[i]);
 345                     }
 346                   this->apply_option(options[j], arg);
 347                   i += skiparg + 1;
 348                 }
 349               break;
 350             }
 351         }
 352       if (j < options_size)
 353         continue;
 354
 355       // If we saw two dashes, we need to see a long option.
 356       if (dashes == 2)
 357         this->usage(_("unknown option"), argv[i]);
 358
 359       // Look for a short option match.  There may be more than one
 360       // short option in a given argument.
 361       bool done = false;
 362       char* s = argv[i] + 1;
 363       ++i;
 364       while (*s != '\0' && !done)
 365         {
 366           char opt = *s;
 367           int j;
 368           for (j = 0; j < options_size; ++j)
 369             {
 370               if (options[j].short_option == opt)
 371                 {
 372                   if (options[j].special)
 373                     {
 374                       // Undo the argument skip done above.
 375                       --i;
 376                       i += options[j].special(argc - i, argv + i, s, this);
 377                       done = true;
 378                     }
 379                   else
 380                     {
 381                       arg = NULL;
 382                       if (options[j].takes_argument())
 383                         {
 384                           if (s[1] != '\0')
 385                             {
 386                               arg = s + 1;
 387                               done = true;
 388                             }
 389                           else if (i < argc)
 390                             {
 391                               arg = argv[i];
 392                               ++i;
 393                             }
 394                           else
 395                             this->usage(_("missing argument"), opt);
 396                         }
 397                       this->apply_option(options[j], arg);
 398                     }
 399                   break;
 400                 }
 401             }
 402
 403           if (j >= options_size)
 404             this->usage(_("unknown option"), *s);
 405
 406           ++s;
 407         }
 408     }
 409
 410   if (this->in_group_)
 411     {
 412       fprintf(stderr, _("%s: missing group end"), program_name);
 413       this->usage();
 414     }
 415
 416   // FIXME: We should only do this when configured in native mode.
 417   this->options_.add_to_search_path("/lib");
 418   this->options_.add_to_search_path("/usr/lib");
 419 }
 420
 421 // Apply a command line option.
 422
 423 void
 424 Command_line::apply_option(const options::One_option& opt,
 425                            const char* arg)
 426 {
 427   if (arg == NULL)
 428     {
 429       if (opt.general_noarg)
 430         (this->options_.*(opt.general_noarg))();
 431       else if (opt.dependent_noarg)
 432         (this->position_options_.*(opt.dependent_noarg))();
 433       else
 434         gold_unreachable();
 435     }
 436   else
 437     {
 438       if (opt.general_arg)
 439         (this->options_.*(opt.general_arg))(arg);
 440       else if (opt.dependent_arg)
 441         (this->position_options_.*(opt.dependent_arg))(arg);
 442       else
 443         gold_unreachable();
 444     }
 445 }
 446
 447 // Add an input file or library.
 448
 449 void
 450 Command_line::add_file(const char* name, bool is_lib)
 451 {
 452   Input_file_argument file(name, is_lib, this->position_options_);
 453   if (!this->in_group_)
 454     this->inputs_.push_back(Input_argument(file));
 455   else
 456     {
 457       assert(!this->inputs_.empty());
 458       assert(this->inputs_.back().is_group());
 459       this->inputs_.back().group()->add_file(file);
 460     }
 461 }
 462
 463 // Handle the -l option, which requires special treatment.
 464
 465 int
 466 Command_line::process_l_option(int argc, char** argv, char* arg)
 467 {
 468   int ret;
 469   const char* libname;
 470   if (arg[1] != '\0')
 471     {
 472       ret = 1;
 473       libname = arg + 1;
 474     }
 475   else if (argc > 1)
 476     {
 477       ret = 2;
 478       libname = argv[argc + 1];
 479     }
 480   else
 481     this->usage(_("missing argument"), arg);
 482
 483   this->add_file(libname, true);
 484
 485   return ret;
 486 }
 487
 488 // Handle the --start-group option.
 489
 490 void
 491 Command_line::start_group(const char* arg)
 492 {
 493   if (this->in_group_)
 494     this->usage(_("may not nest groups"), arg);
 495
 496   // This object is leaked.
 497   Input_file_group* group = new Input_file_group();
 498   this->inputs_.push_back(Input_argument(group));
 499
 500   this->in_group_ = true;
 501 }
 502
 503 // Handle the --end-group option.
 504
 505 void
 506 Command_line::end_group(const char* arg)
 507 {
 508   if (!this->in_group_)
 509     this->usage(_("group end without group start"), arg);
 510   this->in_group_ = false;
 511 }
 512
 513 // Report a usage error.  */
 514
 515 void
 516 Command_line::usage()
 517 {
 518   fprintf(stderr,
 519           _("%s: use the --help option for usage information\n"),
 520           program_name);
 521   gold_exit(false);
 522 }
 523
 524 void
 525 Command_line::usage(const char* msg, const char *opt)
 526 {
 527   fprintf(stderr,
 528           _("%s: %s: %s\n"),
 529           program_name, opt, msg);
 530   this->usage();
 531 }
 532
 533 void
 534 Command_line::usage(const char* msg, char opt)
 535 {
 536   fprintf(stderr,
 537           _("%s: -%c: %s\n"),
 538           program_name, opt, msg);
 539   this->usage();
 540 }
 541
 542 } // End namespace gold.