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', "shared", N_("Generate shared library"),
 221                 NULL, ONE_DASH, &General_options::set_shared),
 222   GENERAL_NOARG('\0', "static", N_("Do not link against shared libraries"),
 223                 NULL, ONE_DASH, &General_options::set_static),
 224   SPECIAL('\0', "help", N_("Report usage information"), NULL,
 225           TWO_DASHES, &help)
 226 };
 227
 228 const int options::Command_line_options::options_size =
 229   sizeof (options) / sizeof (options[0]);
 230
 231 // The default values for the general options.
 232
 233 General_options::General_options()
 234   : search_path_(),
 235     output_file_name_("a.out"),
 236     is_relocatable_(false),
 237     is_shared_(false),
 238     is_static_(false)
 239 {
 240 }
 241
 242 // The default values for the position dependent options.
 243
 244 Position_dependent_options::Position_dependent_options()
 245   : do_static_search_(false)
 246 {
 247 }
 248
 249 // Construct a Command_line.
 250
 251 Command_line::Command_line()
 252 {
 253 }
 254
 255 // Process the command line options.
 256
 257 void
 258 Command_line::process(int argc, char** argv)
 259 {
 260   const int options_size = options::Command_line_options::options_size;
 261   const options::One_option* options =
 262     options::Command_line_options::options;
 263   bool no_more_options = false;
 264   int i = 0;
 265   while (i < argc)
 266     {
 267       if (argv[i][0] != '-' || no_more_options)
 268         {
 269           this->inputs_.push_back(Input_argument(argv[i], false,
 270                                                  this->position_options_));
 271           ++i;
 272           continue;
 273         }
 274
 275       // Option starting with '-'.
 276       int dashes = 1;
 277       if (argv[i][1] == '-')
 278         {
 279           dashes = 2;
 280           if (argv[i][2] == '\0')
 281             {
 282               no_more_options = true;
 283               continue;
 284             }
 285         }
 286
 287       // Look for a long option match.
 288       char* opt = argv[i] + dashes;
 289       char first = opt[0];
 290       int skiparg = 0;
 291       char* arg = strchr(opt, '=');
 292       if (arg != NULL)
 293         *arg = '\0';
 294       else if (i + 1 < argc)
 295         {
 296           arg = argv[i + 1];
 297           skiparg = 1;
 298         }
 299
 300       int j;
 301       for (j = 0; j < options_size; ++j)
 302         {
 303           if (options[j].long_option != NULL
 304               && (dashes == 2
 305                   || (options[j].dash
 306                       != options::One_option::EXACTLY_TWO_DASHES))
 307               && first == options[j].long_option[0]
 308               && strcmp(opt, options[j].long_option) == 0)
 309             {
 310               if (options[j].special)
 311                 i += options[j].special(argc - 1, argv + i, opt, this);
 312               else
 313                 {
 314                   if (!options[j].takes_argument())
 315                     {
 316                       arg = NULL;
 317                       skiparg = 0;
 318                     }
 319                   else
 320                     {
 321                       if (arg == NULL)
 322                         this->usage(_("missing argument"), argv[i]);
 323                     }
 324                   this->apply_option(options[j], arg);
 325                   i += skiparg + 1;
 326                 }
 327               break;
 328             }
 329         }
 330       if (j < options_size)
 331         continue;
 332
 333       // If we saw two dashes, we need to see a long option.
 334       if (dashes == 2)
 335         this->usage(_("unknown option"), argv[i]);
 336
 337       // Look for a short option match.  There may be more than one
 338       // short option in a given argument.
 339       bool done = false;
 340       char* s = argv[i] + 1;
 341       ++i;
 342       while (*s != '\0' && !done)
 343         {
 344           char opt = *s;
 345           int j;
 346           for (j = 0; j < options_size; ++j)
 347             {
 348               if (options[j].short_option == opt)
 349                 {
 350                   if (options[j].special)
 351                     {
 352                       // Undo the argument skip done above.
 353                       --i;
 354                       i += options[j].special(argc - i, argv + i, s, this);
 355                       done = true;
 356                     }
 357                   else
 358                     {
 359                       arg = NULL;
 360                       if (options[j].takes_argument())
 361                         {
 362                           if (s[1] != '\0')
 363                             {
 364                               arg = s + 1;
 365                               done = true;
 366                             }
 367                           else if (i < argc)
 368                             {
 369                               arg = argv[i];
 370                               ++i;
 371                             }
 372                           else
 373                             this->usage(_("missing argument"), opt);
 374                         }
 375                       this->apply_option(options[j], arg);
 376                     }
 377                   break;
 378                 }
 379             }
 380
 381           if (j >= options_size)
 382             this->usage(_("unknown option"), *s);
 383
 384           ++s;
 385         }
 386     }
 387
 388   // FIXME: We should only do this when configured in native mode.
 389   this->options_.add_to_search_path("/lib");
 390   this->options_.add_to_search_path("/usr/lib");
 391 }
 392
 393 // Apply a command line option.
 394
 395 void
 396 Command_line::apply_option(const options::One_option& opt,
 397                            const char* arg)
 398 {
 399   if (arg == NULL)
 400     {
 401       if (opt.general_noarg)
 402         (this->options_.*(opt.general_noarg))();
 403       else if (opt.dependent_noarg)
 404         (this->position_options_.*(opt.dependent_noarg))();
 405       else
 406         gold_unreachable();
 407     }
 408   else
 409     {
 410       if (opt.general_arg)
 411         (this->options_.*(opt.general_arg))(arg);
 412       else if (opt.dependent_arg)
 413         (this->position_options_.*(opt.dependent_arg))(arg);
 414       else
 415         gold_unreachable();
 416     }
 417 }
 418
 419 // Handle the -l option, which requires special treatment.
 420
 421 int
 422 Command_line::process_l_option(int argc, char** argv, char* arg)
 423 {
 424   int ret;
 425   const char* libname;
 426   if (arg[1] != '\0')
 427     {
 428       ret = 1;
 429       libname = arg + 1;
 430     }
 431   else if (argc > 1)
 432     {
 433       ret = 2;
 434       libname = argv[argc + 1];
 435     }
 436   else
 437     this->usage(_("missing argument"), arg);
 438
 439   this->inputs_.push_back(Input_argument(libname, true,
 440                                          this->position_options_));
 441
 442   return ret;
 443 }
 444
 445 // Report a usage error.  */
 446
 447 void
 448 Command_line::usage()
 449 {
 450   fprintf(stderr,
 451           _("%s: use the --help option for usage information\n"),
 452           program_name);
 453   gold_exit(false);
 454 }
 455
 456 void
 457 Command_line::usage(const char* msg, const char *opt)
 458 {
 459   fprintf(stderr,
 460           _("%s: %s: %s\n"),
 461           program_name, opt, msg);
 462   this->usage();
 463 }
 464
 465 void
 466 Command_line::usage(const char* msg, char opt)
 467 {
 468   fprintf(stderr,
 469           _("%s: -%c: %s\n"),
 470           program_name, opt, msg);
 471   this->usage();
 472 }
 473
 474 } // End namespace gold.