gcc/opts-global.c

   1 /* Command line option handling.  Code involving global state that
   2    should not be shared with the driver.
   3    Copyright (C) 2002-2020 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "backend.h"
  25 #include "rtl.h"
  26 #include "tree.h"
  27 #include "tree-pass.h"
  28 #include "diagnostic.h"
  29 #include "opts.h"
  30 #include "flags.h"
  31 #include "langhooks.h"
  32 #include "dbgcnt.h"
  33 #include "debug.h"
  34 #include "output.h"
  35 #include "plugin.h"
  36 #include "toplev.h"
  37 #include "context.h"
  38 #include "stringpool.h"
  39 #include "attribs.h"
  40 #include "asan.h"
  41 #include "file-prefix-map.h" /* add_*_prefix_map()  */
  42
  43 typedef const char *const_char_p; /* For DEF_VEC_P.  */
  44
  45 static vec<const_char_p> ignored_options;
  46
  47 /* Input file names.  */
  48 const char **in_fnames;
  49 unsigned num_in_fnames;
  50
  51 /* Return a malloced slash-separated list of languages in MASK.  */
  52
  53 char *
  54 write_langs (unsigned int mask)
  55 {
  56   unsigned int n = 0, len = 0;
  57   const char *lang_name;
  58   char *result;
  59
  60   for (n = 0; (lang_name = lang_names[n]) != 0; n++)
  61     if (mask & (1U << n))
  62       len += strlen (lang_name) + 1;
  63
  64   result = XNEWVEC (char, len);
  65   len = 0;
  66   for (n = 0; (lang_name = lang_names[n]) != 0; n++)
  67     if (mask & (1U << n))
  68       {
  69         if (len)
  70           result[len++] = '/';
  71         strcpy (result + len, lang_name);
  72         len += strlen (lang_name);
  73       }
  74
  75   result[len] = 0;
  76
  77   return result;
  78 }
  79
  80 /* Complain that switch DECODED does not apply to this front end (mask
  81    LANG_MASK).  */
  82
  83 static void
  84 complain_wrong_lang (const struct cl_decoded_option *decoded,
  85                      unsigned int lang_mask)
  86 {
  87   const struct cl_option *option = &cl_options[decoded->opt_index];
  88   const char *text = decoded->orig_option_with_args_text;
  89   char *ok_langs = NULL, *bad_lang = NULL;
  90   unsigned int opt_flags = option->flags;
  91
  92   if (!lang_hooks.complain_wrong_lang_p (option))
  93     return;
  94
  95   opt_flags &= ((1U << cl_lang_count) - 1) | CL_DRIVER;
  96   if (opt_flags != CL_DRIVER)
  97     ok_langs = write_langs (opt_flags);
  98   if (lang_mask != CL_DRIVER)
  99     bad_lang = write_langs (lang_mask);
 100
 101   if (opt_flags == CL_DRIVER)
 102     error ("command-line option %qs is valid for the driver but not for %s",
 103            text, bad_lang);
 104   else if (lang_mask == CL_DRIVER)
 105     gcc_unreachable ();
 106   else if (ok_langs[0] != '\0')
 107     /* Eventually this should become a hard error IMO.  */
 108     warning (0, "command-line option %qs is valid for %s but not for %s",
 109              text, ok_langs, bad_lang);
 110   else
 111     /* Happens for -Werror=warning_name.  */
 112     warning (0, "%<-Werror=%> argument %qs is not valid for %s",
 113              text, bad_lang);
 114
 115   free (ok_langs);
 116   free (bad_lang);
 117 }
 118
 119 /* Buffer the unknown option described by the string OPT.  Currently,
 120    we only complain about unknown -Wno-* options if they may have
 121    prevented a diagnostic. Otherwise, we just ignore them.  Note that
 122    if we do complain, it is only as a warning, not an error; passing
 123    the compiler an unrecognized -Wno-* option should never change
 124    whether the compilation succeeds or fails.  */
 125
 126 static void
 127 postpone_unknown_option_warning (const char *opt)
 128 {
 129   ignored_options.safe_push (opt);
 130 }
 131
 132 /* Produce a warning for each option previously buffered.  */
 133
 134 void
 135 print_ignored_options (void)
 136 {
 137   while (!ignored_options.is_empty ())
 138     {
 139       const char *opt;
 140
 141       opt = ignored_options.pop ();
 142       /* Use inform, not warning_at, to avoid promoting these to errors.  */
 143       inform (UNKNOWN_LOCATION,
 144               "unrecognized command-line option %qs may have been intended "
 145               "to silence earlier diagnostics", opt);
 146     }
 147 }
 148
 149 /* Handle an unknown option DECODED, returning true if an error should
 150    be given.  */
 151
 152 static bool
 153 unknown_option_callback (const struct cl_decoded_option *decoded)
 154 {
 155   const char *opt = decoded->arg;
 156
 157   if (opt[1] == 'W' && opt[2] == 'n' && opt[3] == 'o' && opt[4] == '-'
 158       && !(decoded->errors & CL_ERR_NEGATIVE))
 159     {
 160       /* We don't generate warnings for unknown -Wno-* options unless
 161          we issue diagnostics.  */
 162       postpone_unknown_option_warning (opt);
 163       return false;
 164     }
 165   else
 166     return true;
 167 }
 168
 169 /* Handle a front-end option; arguments and return value as for
 170    handle_option.  */
 171
 172 static bool
 173 lang_handle_option (struct gcc_options *opts,
 174                     struct gcc_options *opts_set,
 175                     const struct cl_decoded_option *decoded,
 176                     unsigned int lang_mask ATTRIBUTE_UNUSED, int kind,
 177                     location_t loc,
 178                     const struct cl_option_handlers *handlers,
 179                     diagnostic_context *dc,
 180                     void (*) (void))
 181 {
 182   gcc_assert (opts == &global_options);
 183   gcc_assert (opts_set == &global_options_set);
 184   gcc_assert (dc == global_dc);
 185   gcc_assert (decoded->canonical_option_num_elements <= 2);
 186   return lang_hooks.handle_option (decoded->opt_index, decoded->arg,
 187                                    decoded->value, kind, loc, handlers);
 188 }
 189
 190 /* Handle FILENAME from the command line.  */
 191
 192 static void
 193 add_input_filename (const char *filename)
 194 {
 195   num_in_fnames++;
 196   in_fnames = XRESIZEVEC (const char *, in_fnames, num_in_fnames);
 197   in_fnames[num_in_fnames - 1] = filename;
 198 }
 199
 200 /* Handle the vector of command line options (located at LOC), storing
 201    the results of processing DECODED_OPTIONS and DECODED_OPTIONS_COUNT
 202    in OPTS and OPTS_SET and using DC for diagnostic state.  LANG_MASK
 203    contains has a single bit set representing the current language.
 204    HANDLERS describes what functions to call for the options.  */
 205
 206 static void
 207 read_cmdline_options (struct gcc_options *opts, struct gcc_options *opts_set,
 208                       struct cl_decoded_option *decoded_options,
 209                       unsigned int decoded_options_count,
 210                       location_t loc,
 211                       unsigned int lang_mask,
 212                       const struct cl_option_handlers *handlers,
 213                       diagnostic_context *dc)
 214 {
 215   unsigned int i;
 216
 217   for (i = 1; i < decoded_options_count; i++)
 218     {
 219       if (decoded_options[i].opt_index == OPT_SPECIAL_input_file)
 220         {
 221           /* Input files should only ever appear on the main command
 222              line.  */
 223           gcc_assert (opts == &global_options);
 224           gcc_assert (opts_set == &global_options_set);
 225
 226           if (opts->x_main_input_filename == NULL)
 227             {
 228               opts->x_main_input_filename = decoded_options[i].arg;
 229               opts->x_main_input_baselength
 230                 = base_of_path (opts->x_main_input_filename,
 231                                 &opts->x_main_input_basename);
 232             }
 233           add_input_filename (decoded_options[i].arg);
 234           continue;
 235         }
 236
 237       read_cmdline_option (opts, opts_set,
 238                            decoded_options + i, loc, lang_mask, handlers,
 239                            dc);
 240     }
 241 }
 242
 243 /* Language mask determined at initialization.  */
 244 static unsigned int initial_lang_mask;
 245
 246 /* Initialize global options-related settings at start-up.  */
 247
 248 void
 249 init_options_once (void)
 250 {
 251   /* Perform language-specific options initialization.  */
 252   initial_lang_mask = lang_hooks.option_lang_mask ();
 253
 254   lang_hooks.initialize_diagnostics (global_dc);
 255   /* ??? Ideally, we should do this earlier and the FEs will override
 256      it if desired (none do it so far).  However, the way the FEs
 257      construct their pretty-printers means that all previous settings
 258      are overriden.  */
 259   diagnostic_color_init (global_dc);
 260   diagnostic_urls_init (global_dc);
 261 }
 262
 263 /* Decode command-line options to an array, like
 264    decode_cmdline_options_to_array and with the same arguments but
 265    using the default lang_mask.  */
 266
 267 void
 268 decode_cmdline_options_to_array_default_mask (unsigned int argc,
 269                                               const char **argv,
 270                                               struct cl_decoded_option **decoded_options,
 271                                               unsigned int *decoded_options_count)
 272 {
 273   decode_cmdline_options_to_array (argc, argv,
 274                                    initial_lang_mask | CL_COMMON | CL_TARGET,
 275                                    decoded_options, decoded_options_count);
 276 }
 277
 278 /* Set *HANDLERS to the default set of option handlers for use in the
 279    compilers proper (not the driver).  */
 280 void
 281 set_default_handlers (struct cl_option_handlers *handlers,
 282                       void (*target_option_override_hook) (void))
 283 {
 284   handlers->unknown_option_callback = unknown_option_callback;
 285   handlers->wrong_lang_callback = complain_wrong_lang;
 286   handlers->target_option_override_hook = target_option_override_hook;
 287   handlers->num_handlers = 3;
 288   handlers->handlers[0].handler = lang_handle_option;
 289   handlers->handlers[0].mask = initial_lang_mask;
 290   handlers->handlers[1].handler = common_handle_option;
 291   handlers->handlers[1].mask = CL_COMMON;
 292   handlers->handlers[2].handler = target_handle_option;
 293   handlers->handlers[2].mask = CL_TARGET;
 294 }
 295
 296 /* Parse command line options and set default flag values.  Do minimal
 297    options processing.  The decoded options are in *DECODED_OPTIONS
 298    and *DECODED_OPTIONS_COUNT; settings go in OPTS, OPTS_SET and DC;
 299    the options are located at LOC.  */
 300 void
 301 decode_options (struct gcc_options *opts, struct gcc_options *opts_set,
 302                 struct cl_decoded_option *decoded_options,
 303                 unsigned int decoded_options_count,
 304                 location_t loc, diagnostic_context *dc,
 305                 void (*target_option_override_hook) (void))
 306 {
 307   struct cl_option_handlers handlers;
 308
 309   unsigned int lang_mask;
 310
 311   lang_mask = initial_lang_mask;
 312
 313   set_default_handlers (&handlers, target_option_override_hook);
 314
 315   default_options_optimization (opts, opts_set,
 316                                 decoded_options, decoded_options_count,
 317                                 loc, lang_mask, &handlers, dc);
 318
 319   read_cmdline_options (opts, opts_set,
 320                         decoded_options, decoded_options_count,
 321                         loc, lang_mask,
 322                         &handlers, dc);
 323
 324   finish_options (opts, opts_set, loc);
 325
 326   /* Print --help=* if used.  */
 327   unsigned i;
 328   const char *arg;
 329
 330   FOR_EACH_VEC_ELT (help_option_arguments, i, arg)
 331     print_help (opts, lang_mask, arg);
 332 }
 333
 334 /* Hold command-line options associated with stack limitation.  */
 335 const char *opt_fstack_limit_symbol_arg = NULL;
 336 int opt_fstack_limit_register_no = -1;
 337
 338 /* Process common options that have been deferred until after the
 339    handlers have been called for all options.  */
 340
 341 void
 342 handle_common_deferred_options (void)
 343 {
 344   unsigned int i;
 345   cl_deferred_option *opt;
 346   vec<cl_deferred_option> v;
 347
 348   if (common_deferred_options)
 349     v = *((vec<cl_deferred_option> *) common_deferred_options);
 350   else
 351     v = vNULL;
 352
 353   if (flag_dump_all_passed)
 354     enable_rtl_dump_file ();
 355
 356   if (flag_opt_info)
 357     opt_info_switch_p (NULL);
 358
 359   FOR_EACH_VEC_ELT (v, i, opt)
 360     {
 361       switch (opt->opt_index)
 362         {
 363         case OPT_fcall_used_:
 364           fix_register (opt->arg, 0, 1);
 365           break;
 366
 367         case OPT_fcall_saved_:
 368           fix_register (opt->arg, 0, 0);
 369           break;
 370
 371         case OPT_fdbg_cnt_:
 372           dbg_cnt_process_opt (opt->arg);
 373           break;
 374
 375         case OPT_fdbg_cnt_list:
 376           dbg_cnt_list_all_counters ();
 377           break;
 378
 379         case OPT_fdebug_prefix_map_:
 380           add_debug_prefix_map (opt->arg);
 381           break;
 382
 383         case OPT_ffile_prefix_map_:
 384           add_file_prefix_map (opt->arg);
 385           break;
 386
 387         case OPT_fdump_:
 388           g->get_dumps ()->dump_switch_p (opt->arg);
 389           break;
 390
 391         case OPT_fopt_info_:
 392           if (!opt_info_switch_p (opt->arg))
 393             error ("unrecognized command-line option %<-fopt-info-%s%>",
 394                    opt->arg);
 395           break;
 396
 397         case OPT_fenable_:
 398         case OPT_fdisable_:
 399           if (opt->opt_index == OPT_fenable_)
 400             enable_pass (opt->arg);
 401           else
 402             disable_pass (opt->arg);
 403           break;
 404
 405         case OPT_ffixed_:
 406           /* Deferred.  */
 407           fix_register (opt->arg, 1, 1);
 408           break;
 409
 410         case OPT_fplugin_:
 411 #ifdef ENABLE_PLUGIN
 412           add_new_plugin (opt->arg);
 413 #else
 414           error ("plugin support is disabled; configure with --enable-plugin");
 415 #endif
 416           break;
 417
 418         case OPT_fplugin_arg_:
 419 #ifdef ENABLE_PLUGIN
 420           parse_plugin_arg_opt (opt->arg);
 421 #else
 422           error ("plugin support is disabled; configure with --enable-plugin");
 423 #endif
 424           break;
 425
 426         case OPT_frandom_seed:
 427           /* The real switch is -fno-random-seed.  */
 428           if (!opt->value)
 429             set_random_seed (NULL);
 430           break;
 431
 432         case OPT_frandom_seed_:
 433           set_random_seed (opt->arg);
 434           break;
 435
 436         case OPT_fstack_limit:
 437           /* The real switch is -fno-stack-limit.  */
 438           if (!opt->value)
 439             stack_limit_rtx = NULL_RTX;
 440           break;
 441
 442         case OPT_fstack_limit_register_:
 443           {
 444             int reg = decode_reg_name (opt->arg);
 445             if (reg < 0)
 446               error ("unrecognized register name %qs", opt->arg);
 447             else
 448               {
 449                 /* Deactivate previous OPT_fstack_limit_symbol_ options.  */
 450                 opt_fstack_limit_symbol_arg = NULL;
 451                 opt_fstack_limit_register_no = reg;
 452               }
 453           }
 454           break;
 455
 456         case OPT_fstack_limit_symbol_:
 457           /* Deactivate previous OPT_fstack_limit_register_ options.  */
 458           opt_fstack_limit_register_no = -1;
 459           opt_fstack_limit_symbol_arg = opt->arg;
 460           break;
 461
 462         case OPT_fasan_shadow_offset_:
 463           if (!(flag_sanitize & SANITIZE_KERNEL_ADDRESS))
 464             error ("%<-fasan-shadow-offset%> should only be used "
 465                    "with %<-fsanitize=kernel-address%>");
 466           if (!set_asan_shadow_offset (opt->arg))
 467              error ("unrecognized shadow offset %qs", opt->arg);
 468           break;
 469
 470         case OPT_fsanitize_sections_:
 471           set_sanitized_sections (opt->arg);
 472           break;
 473
 474         default:
 475           gcc_unreachable ();
 476         }
 477     }
 478 }