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 // Report usage information for ld --help, and exit.
  93
  94 int
  95 help(int, char**, char*, gold::Command_line*)
  96 {
  97   printf(_("Usage: %s [options] file...\nOptions:\n"), gold::program_name);
  98
  99   const int options_size = gold::options::Command_line_options::options_size;
 100   const gold::options::One_option* options =
 101     gold::options::Command_line_options::options;
 102   for (int i = 0; i < options_size; ++i)
 103     {
 104       if (options[i].doc == NULL)
 105         continue;
 106
 107       printf("  ");
 108       int len = 2;
 109       bool comma = false;
 110
 111       int j = i;
 112       do
 113         {
 114           if (options[j].help_output != NULL)
 115             {
 116               if (comma)
 117                 {
 118                   printf(", ");
 119                   len += 2;
 120                 }
 121               printf(options[j].help_output);
 122               len += std::strlen(options[i].help_output);
 123             }
 124           else
 125             {
 126               if (options[j].short_option != '\0')
 127                 {
 128                   if (comma)
 129                     {
 130                       printf(", ");
 131                       len += 2;
 132                     }
 133                   printf("-%c", options[j].short_option);
 134                   len += 2;
 135                 }
 136
 137               if (options[j].long_option != NULL)
 138                 {
 139                   if (comma)
 140                     {
 141                       printf(", ");
 142                       len += 2;
 143                     }
 144                   if (options[j].dash == gold::options::One_option::ONE_DASH)
 145                     {
 146                       printf("-");
 147                       ++len;
 148                     }
 149                   else
 150                     {
 151                       printf("--");
 152                       len += 2;
 153                     }
 154                   printf("%s", options[j].long_option);
 155                   len += std::strlen(options[j].long_option);
 156                 }
 157             }
 158           ++j;
 159         }
 160       while (j < options_size && options[j].doc == NULL);
 161
 162       if (len > 30)
 163         {
 164           printf("\n");
 165           len = 0;
 166         }
 167       for (; len < 30; ++len)
 168         std::putchar(' ');
 169
 170       std::puts(options[i].doc);
 171     }
 172
 173   gold::gold_exit(true);
 174
 175   return 0;
 176 }
 177
 178 } // End anonymous namespace.
 179
 180 namespace gold
 181 {
 182
 183 // Helper macros used to specify the options.  We could also do this
 184 // using constructors, but then g++ would generate code to initialize
 185 // the array.  We want the array to be initialized statically so that
 186 // we get better startup time.
 187
 188 #define GENERAL_NOARG(short_option, long_option, doc, help, dash, func) \
 189   { short_option, long_option, doc, help, options::One_option::dash, \
 190       NULL, func, NULL, NULL, NULL }
 191 #define GENERAL_ARG(short_option, long_option, doc, help, dash, func)   \
 192   { short_option, long_option, doc, help, options::One_option::dash, \
 193       NULL, NULL, func, NULL, NULL }
 194 #define POSDEP_NOARG(short_option, long_option, doc, help, dash, func)  \
 195   { short_option, long_option, doc, help, options::One_option::dash, \
 196       NULL,  NULL, NULL, func, NULL }
 197 #define POSDEP_ARG(short_option, long_option, doc, help, dash, func)    \
 198   { short_option, long_option, doc, help, options::One_option::dash, \
 199       NULL, NULL, NULL, NULL, func }
 200 #define SPECIAL(short_option, long_option, doc, help, dash, func)       \
 201   { short_option, long_option, doc, help, options::One_option::dash, \
 202       func, NULL, NULL, NULL, NULL }
 203
 204 // Here is the actual list of options which we accept.
 205
 206 const options::One_option
 207 options::Command_line_options::options[] =
 208 {
 209   SPECIAL('l', "library", N_("Search for library LIBNAME"),
 210           N_("-lLIBNAME --library LIBNAME"), TWO_DASHES,
 211           &library),
 212   GENERAL_ARG('L', "library-path", N_("Add directory to search path"),
 213               N_("-L DIR, --library-path DIR"), TWO_DASHES,
 214               &General_options::add_to_search_path),
 215   GENERAL_ARG('o', "output", N_("Set output file name"),
 216               N_("-o FILE, --output FILE"), TWO_DASHES,
 217               &General_options::set_output_file_name),
 218   GENERAL_NOARG('r', NULL, N_("Generate relocatable output"), NULL,
 219                 ONE_DASH, &General_options::set_relocatable),
 220   GENERAL_NOARG('\0', "static", N_("Do not link against shared libraries"),
 221                 NULL, ONE_DASH, &General_options::set_static),
 222   SPECIAL('\0', "help", N_("Report usage information"), NULL,
 223           TWO_DASHES, &help)
 224 };
 225
 226 const int options::Command_line_options::options_size =
 227   sizeof (options) / sizeof (options[0]);
 228
 229 // The default values for the general options.
 230
 231 General_options::General_options()
 232   : search_path_(),
 233     output_file_name_("a.out"),
 234     is_relocatable_(false),
 235     is_static_(false)
 236 {
 237 }
 238
 239 // The default values for the position dependent options.
 240
 241 Position_dependent_options::Position_dependent_options()
 242   : do_static_search_(false)
 243 {
 244 }
 245
 246 // Construct a Command_line.
 247
 248 Command_line::Command_line()
 249 {
 250 }
 251
 252 // Process the command line options.
 253
 254 void
 255 Command_line::process(int argc, char** argv)
 256 {
 257   const int options_size = options::Command_line_options::options_size;
 258   const options::One_option* options =
 259     options::Command_line_options::options;
 260   bool no_more_options = false;
 261   int i = 0;
 262   while (i < argc)
 263     {
 264       if (argv[i][0] != '-' || no_more_options)
 265         {
 266           this->inputs_.push_back(Input_argument(argv[i], false,
 267                                                  this->position_options_));
 268           ++i;
 269           continue;
 270         }
 271
 272       // Option starting with '-'.
 273       int dashes = 1;
 274       if (argv[i][1] == '-')
 275         {
 276           dashes = 2;
 277           if (argv[i][2] == '\0')
 278             {
 279               no_more_options = true;
 280               continue;
 281             }
 282         }
 283
 284       // Look for a long option match.
 285       char* opt = argv[i] + dashes;
 286       char first = opt[0];
 287       int skiparg = 0;
 288       char* arg = strchr(opt, '=');
 289       if (arg != NULL)
 290         *arg = '\0';
 291       else if (i + 1 < argc)
 292         {
 293           arg = argv[i + 1];
 294           skiparg = 1;
 295         }
 296
 297       int j;
 298       for (j = 0; j < options_size; ++j)
 299         {
 300           if (options[j].long_option != NULL
 301               && (dashes == 2
 302                   || (options[j].dash
 303                       != options::One_option::EXACTLY_TWO_DASHES))
 304               && first == options[j].long_option[0]
 305               && strcmp(opt, options[j].long_option) == 0)
 306             {
 307               if (options[j].special)
 308                 i += options[j].special(argc - 1, argv + i, opt, this);
 309               else
 310                 {
 311                   if (!options[j].takes_argument())
 312                     {
 313                       arg = NULL;
 314                       skiparg = 0;
 315                     }
 316                   else
 317                     {
 318                       if (arg == NULL)
 319                         this->usage(_("missing argument"), argv[i]);
 320                     }
 321                   this->apply_option(options[j], arg);
 322                   i += skiparg + 1;
 323                 }
 324               break;
 325             }
 326         }
 327       if (j < options_size)
 328         continue;
 329
 330       // If we saw two dashes, we need to see a long option.
 331       if (dashes == 2)
 332         this->usage(_("unknown option"), argv[i]);
 333
 334       // Look for a short option match.  There may be more than one
 335       // short option in a given argument.
 336       bool done = false;
 337       char* s = argv[i] + 1;
 338       ++i;
 339       while (*s != '\0' && !done)
 340         {
 341           char opt = *s;
 342           int j;
 343           for (j = 0; j < options_size; ++j)
 344             {
 345               if (options[j].short_option == opt)
 346                 {
 347                   if (options[j].special)
 348                     {
 349                       // Undo the argument skip done above.
 350                       --i;
 351                       i += options[j].special(argc - i, argv + i, s, this);
 352                       done = true;
 353                     }
 354                   else
 355                     {
 356                       arg = NULL;
 357                       if (options[j].takes_argument())
 358                         {
 359                           if (s[1] != '\0')
 360                             {
 361                               arg = s + 1;
 362                               done = true;
 363                             }
 364                           else if (i < argc)
 365                             {
 366                               arg = argv[i];
 367                               ++i;
 368                             }
 369                           else
 370                             this->usage(_("missing argument"), opt);
 371                         }
 372                       this->apply_option(options[j], arg);
 373                     }
 374                   break;
 375                 }
 376             }
 377
 378           if (j >= options_size)
 379             this->usage(_("unknown option"), *s);
 380
 381           ++s;
 382         }
 383     }
 384
 385   // FIXME: We should only do this when configured in native mode.
 386   this->options_.add_to_search_path("/lib");
 387   this->options_.add_to_search_path("/usr/lib");
 388 }
 389
 390 // Apply a command line option.
 391
 392 void
 393 Command_line::apply_option(const options::One_option& opt,
 394                            const char* arg)
 395 {
 396   if (arg == NULL)
 397     {
 398       if (opt.general_noarg)
 399         (this->options_.*(opt.general_noarg))();
 400       else if (opt.dependent_noarg)
 401         (this->position_options_.*(opt.dependent_noarg))();
 402       else
 403         gold_unreachable();
 404     }
 405   else
 406     {
 407       if (opt.general_arg)
 408         (this->options_.*(opt.general_arg))(arg);
 409       else if (opt.dependent_arg)
 410         (this->position_options_.*(opt.dependent_arg))(arg);
 411       else
 412         gold_unreachable();
 413     }
 414 }
 415
 416 // Handle the -l option, which requires special treatment.
 417
 418 int
 419 Command_line::process_l_option(int argc, char** argv, char* arg)
 420 {
 421   int ret;
 422   const char* libname;
 423   if (arg[1] != '\0')
 424     {
 425       ret = 1;
 426       libname = arg + 1;
 427     }
 428   else if (argc > 1)
 429     {
 430       ret = 2;
 431       libname = argv[argc + 1];
 432     }
 433   else
 434     this->usage(_("missing argument"), arg);
 435
 436   this->inputs_.push_back(Input_argument(libname, true,
 437                                          this->position_options_));
 438
 439   return ret;
 440 }
 441
 442 // Report a usage error.  */
 443
 444 void
 445 Command_line::usage()
 446 {
 447   fprintf(stderr,
 448           _("%s: use the --help option for usage information\n"),
 449           program_name);
 450   gold_exit(false);
 451 }
 452
 453 void
 454 Command_line::usage(const char* msg, const char *opt)
 455 {
 456   fprintf(stderr,
 457           _("%s: %s: %s\n"),
 458           program_name, opt, msg);
 459   this->usage();
 460 }
 461
 462 void
 463 Command_line::usage(const char* msg, char opt)
 464 {
 465   fprintf(stderr,
 466           _("%s: -%c: %s\n"),
 467           program_name, opt, msg);
 468   this->usage();
 469 }
 470
 471 } // End namespace gold.