gcc/opts.c

   1 /* Command line option handling.
   2    Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   3    Contributed by Neil Booth.
   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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "intl.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "tree.h"
  28 #include "rtl.h"
  29 #include "ggc.h"
  30 #include "output.h"
  31 #include "langhooks.h"
  32 #include "opts.h"
  33 #include "options.h"
  34 #include "flags.h"
  35 #include "toplev.h"
  36 #include "params.h"
  37 #include "diagnostic.h"
  38 #include "tm_p.h"               /* For OPTIMIZATION_OPTIONS.  */
  39 #include "insn-attr.h"          /* For INSN_SCHEDULING.  */
  40
  41 /* Value of the -G xx switch, and whether it was passed or not.  */
  42 unsigned HOST_WIDE_INT g_switch_value;
  43 bool g_switch_set;
  44
  45 /* True if we should exit after parsing options.  */
  46 bool exit_after_options;
  47
  48 /* If -version.  */
  49 bool version_flag;
  50
  51 /* Print various extra warnings.  -W/-Wextra.  */
  52 bool extra_warnings;
  53
  54 /* Don't print warning messages.  -w.  */
  55 bool inhibit_warnings;
  56
  57 /* Treat warnings as errors.  -Werror.  */
  58 bool warnings_are_errors;
  59
  60 /* Warn if a function returns an aggregate, since there are often
  61    incompatible calling conventions for doing this.  */
  62 bool warn_aggregate_return;
  63
  64 /* Nonzero means warn about pointer casts that increase the required
  65    alignment of the target type (and might therefore lead to a crash
  66    due to a misaligned access).  */
  67 bool warn_cast_align;
  68
  69 /* Nonzero means warn about uses of __attribute__((deprecated))
  70    declarations.  */
  71 bool warn_deprecated_decl = true;
  72
  73 /* Warn when an optimization pass is disabled.  */
  74 bool warn_disabled_optimization;
  75
  76 /* Nonzero means warn if inline function is too large.  */
  77 bool warn_inline;
  78
  79 /* True to warn about any objects definitions whose size is larger
  80    than N bytes.  Also want about function definitions whose returned
  81    values are larger than N bytes, where N is `larger_than_size'.  */
  82 bool warn_larger_than;
  83 HOST_WIDE_INT larger_than_size;
  84
  85 /* Warn about functions which might be candidates for attribute noreturn.  */
  86 bool warn_missing_noreturn;
  87
  88 /* True to warn about code which is never reached.  */
  89 bool warn_notreached;
  90
  91 /* Warn if packed attribute on struct is unnecessary and inefficient.  */
  92 bool warn_packed;
  93
  94 /* Warn when gcc pads a structure to an alignment boundary.  */
  95 bool warn_padded;
  96
  97 /* True means warn about all declarations which shadow others.  */
  98 bool warn_shadow;
  99
 100 /* Nonzero means warn about constructs which might not be
 101    strict-aliasing safe.  */
 102 bool warn_strict_aliasing;
 103
 104 /* True to warn if a switch on an enum, that does not have a default
 105    case, fails to have a case for every enum value.  */
 106 bool warn_switch;
 107
 108 /* Warn if a switch does not have a default case.  */
 109 bool warn_switch_default;
 110
 111 /* Warn if a switch on an enum fails to have a case for every enum
 112    value (regardless of the presence or otherwise of a default case).  */
 113 bool warn_switch_enum;
 114
 115 /* Don't suppress warnings from system headers.  -Wsystem-headers.  */
 116 bool warn_system_headers;
 117
 118 /* True to warn about variables used before they are initialized.  */
 119 int warn_uninitialized;
 120
 121 /* True to warn about unused variables, functions et.al.  */
 122 bool warn_unused_function;
 123 bool warn_unused_label;
 124 bool warn_unused_parameter;
 125 bool warn_unused_variable;
 126 bool warn_unused_value;
 127
 128 /* Hack for cooperation between set_Wunused and set_Wextra.  */
 129 static bool maybe_warn_unused_parameter;
 130
 131 /* Type(s) of debugging information we are producing (if any).  See
 132    flags.h for the definitions of the different possible types of
 133    debugging information.  */
 134 enum debug_info_type write_symbols = NO_DEBUG;
 135
 136 /* Level of debugging information we are producing.  See flags.h for
 137    the definitions of the different possible levels.  */
 138 enum debug_info_level debug_info_level = DINFO_LEVEL_NONE;
 139
 140 /* Nonzero means use GNU-only extensions in the generated symbolic
 141    debugging information.  Currently, this only has an effect when
 142    write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.  */
 143 bool use_gnu_debug_info_extensions;
 144
 145 /* Columns of --help display.  */
 146 static unsigned int columns = 80;
 147
 148 /* What to print when a switch has no documentation.  */
 149 static const char undocumented_msg[] = N_("This switch lacks documentation");
 150
 151 /* Input file names.  */
 152 const char **in_fnames;
 153 unsigned num_in_fnames;
 154
 155 static size_t find_opt (const char *, int);
 156 static int common_handle_option (size_t scode, const char *arg, int value);
 157 static void handle_param (const char *);
 158 static void set_Wextra (int);
 159 static unsigned int handle_option (const char **argv, unsigned int lang_mask);
 160 static char *write_langs (unsigned int lang_mask);
 161 static void complain_wrong_lang (const char *, const struct cl_option *,
 162                                  unsigned int lang_mask);
 163 static void handle_options (unsigned int, const char **, unsigned int);
 164 static void wrap_help (const char *help, const char *item, unsigned int);
 165 static void print_help (void);
 166 static void print_param_help (void);
 167 static void print_filtered_help (unsigned int flag);
 168 static unsigned int print_switch (const char *text, unsigned int indent);
 169 static void set_debug_level (enum debug_info_type type, int extended,
 170                              const char *arg);
 171
 172 /* Perform a binary search to find which option the command-line INPUT
 173    matches.  Returns its index in the option array, and N_OPTS
 174    (cl_options_count) on failure.
 175
 176    This routine is quite subtle.  A normal binary search is not good
 177    enough because some options can be suffixed with an argument, and
 178    multiple sub-matches can occur, e.g. input of "-pedantic" matching
 179    the initial substring of "-pedantic-errors".
 180
 181    A more complicated example is -gstabs.  It should match "-g" with
 182    an argument of "stabs".  Suppose, however, that the number and list
 183    of switches are such that the binary search tests "-gen-decls"
 184    before having tested "-g".  This doesn't match, and as "-gen-decls"
 185    is less than "-gstabs", it will become the lower bound of the
 186    binary search range, and "-g" will never be seen.  To resolve this
 187    issue, opts.sh makes "-gen-decls" point, via the back_chain member,
 188    to "-g" so that failed searches that end between "-gen-decls" and
 189    the lexicographically subsequent switch know to go back and see if
 190    "-g" causes a match (which it does in this example).
 191
 192    This search is done in such a way that the longest match for the
 193    front end in question wins.  If there is no match for the current
 194    front end, the longest match for a different front end is returned
 195    (or N_OPTS if none) and the caller emits an error message.  */
 196 static size_t
 197 find_opt (const char *input, int lang_mask)
 198 {
 199   size_t mn, mx, md, opt_len;
 200   size_t match_wrong_lang;
 201   int comp;
 202
 203   mn = 0;
 204   mx = cl_options_count;
 205
 206   /* Find mn such this lexicographical inequality holds:
 207      cl_options[mn] <= input < cl_options[mn + 1].  */
 208   while (mx - mn > 1)
 209     {
 210       md = (mn + mx) / 2;
 211       opt_len = cl_options[md].opt_len;
 212       comp = strncmp (input, cl_options[md].opt_text + 1, opt_len);
 213
 214       if (comp < 0)
 215         mx = md;
 216       else
 217         mn = md;
 218     }
 219
 220   /* This is the switch that is the best match but for a different
 221      front end, or cl_options_count if there is no match at all.  */
 222   match_wrong_lang = cl_options_count;
 223
 224   /* Backtrace the chain of possible matches, returning the longest
 225      one, if any, that fits best.  With current GCC switches, this
 226      loop executes at most twice.  */
 227   do
 228     {
 229       const struct cl_option *opt = &cl_options[mn];
 230
 231       /* Is this switch a prefix of the input?  */
 232       if (!strncmp (input, opt->opt_text + 1, opt->opt_len))
 233         {
 234           /* If language is OK, and the match is exact or the switch
 235              takes a joined argument, return it.  */
 236           if ((opt->flags & lang_mask)
 237               && (input[opt->opt_len] == '\0' || (opt->flags & CL_JOINED)))
 238             return mn;
 239
 240           /* If we haven't remembered a prior match, remember this
 241              one.  Any prior match is necessarily better.  */
 242           if (match_wrong_lang == cl_options_count)
 243             match_wrong_lang = mn;
 244         }
 245
 246       /* Try the next possibility.  This is cl_options_count if there
 247          are no more.  */
 248       mn = opt->back_chain;
 249     }
 250   while (mn != cl_options_count);
 251
 252   /* Return the best wrong match, or cl_options_count if none.  */
 253   return match_wrong_lang;
 254 }
 255
 256 /* If ARG is a non-negative integer made up solely of digits, return its
 257    value, otherwise return -1.  */
 258 static int
 259 integral_argument (const char *arg)
 260 {
 261   const char *p = arg;
 262
 263   while (*p && ISDIGIT (*p))
 264     p++;
 265
 266   if (*p == '\0')
 267     return atoi (arg);
 268
 269   return -1;
 270 }
 271
 272 /* Return a malloced slash-separated list of languages in MASK.  */
 273 static char *
 274 write_langs (unsigned int mask)
 275 {
 276   unsigned int n = 0, len = 0;
 277   const char *lang_name;
 278   char *result;
 279
 280   for (n = 0; (lang_name = lang_names[n]) != 0; n++)
 281     if (mask & (1U << n))
 282       len += strlen (lang_name) + 1;
 283
 284   result = xmalloc (len);
 285   len = 0;
 286   for (n = 0; (lang_name = lang_names[n]) != 0; n++)
 287     if (mask & (1U << n))
 288       {
 289         if (len)
 290           result[len++] = '/';
 291         strcpy (result + len, lang_name);
 292         len += strlen (lang_name);
 293       }
 294
 295   result[len] = 0;
 296
 297   return result;
 298 }
 299
 300 /* Complain that switch OPT_INDEX does not apply to this front end.  */
 301 static void
 302 complain_wrong_lang (const char *text, const struct cl_option *option,
 303                      unsigned int lang_mask)
 304 {
 305   char *ok_langs, *bad_lang;
 306
 307   ok_langs = write_langs (option->flags);
 308   bad_lang = write_langs (lang_mask);
 309
 310   /* Eventually this should become a hard error IMO.  */
 311   warning ("command line option \"%s\" is valid for %s but not for %s",
 312            text, ok_langs, bad_lang);
 313
 314   free (ok_langs);
 315   free (bad_lang);
 316 }
 317
 318 /* Handle the switch beginning at ARGV for the language indicated by
 319    LANG_MASK.  Returns the number of switches consumed.  */
 320 static unsigned int
 321 handle_option (const char **argv, unsigned int lang_mask)
 322 {
 323   size_t opt_index;
 324   const char *opt, *arg = 0;
 325   char *dup = 0;
 326   int value = 1;
 327   unsigned int result = 0;
 328   const struct cl_option *option;
 329
 330   opt = argv[0];
 331
 332   /* Drop the "no-" from negative switches.  */
 333   if ((opt[1] == 'W' || opt[1] == 'f')
 334       && opt[2] == 'n' && opt[3] == 'o' && opt[4] == '-')
 335     {
 336       size_t len = strlen (opt) - 3;
 337
 338       dup = xmalloc (len + 1);
 339       dup[0] = '-';
 340       dup[1] = opt[1];
 341       memcpy (dup + 2, opt + 5, len - 2 + 1);
 342       opt = dup;
 343       value = 0;
 344     }
 345
 346   opt_index = find_opt (opt + 1, lang_mask | CL_COMMON);
 347   if (opt_index == cl_options_count)
 348     goto done;
 349
 350   option = &cl_options[opt_index];
 351
 352   /* Reject negative form of switches that don't take negatives as
 353      unrecognized.  */
 354   if (!value && (option->flags & CL_REJECT_NEGATIVE))
 355     goto done;
 356
 357   /* We've recognized this switch.  */
 358   result = 1;
 359
 360   /* Sort out any argument the switch takes.  */
 361   if (option->flags & CL_JOINED)
 362     {
 363       /* Have arg point to the original switch.  This is because
 364          some code, such as disable_builtin_function, expects its
 365          argument to be persistent until the program exits.  */
 366       arg = argv[0] + cl_options[opt_index].opt_len + 1;
 367       if (!value)
 368         arg += strlen ("no-");
 369
 370       if (*arg == '\0' && !(option->flags & CL_MISSING_OK))
 371         {
 372           if (option->flags & CL_SEPARATE)
 373             {
 374               arg = argv[1];
 375               result = 2;
 376             }
 377           else
 378             /* Missing argument.  */
 379             arg = NULL;
 380         }
 381     }
 382   else if (option->flags & CL_SEPARATE)
 383     {
 384       arg = argv[1];
 385       result = 2;
 386     }
 387
 388   /* Now we've swallowed any potential argument, complain if this
 389      is a switch for a different front end.  */
 390   if (!(option->flags & (lang_mask | CL_COMMON)))
 391     {
 392       complain_wrong_lang (argv[0], option, lang_mask);
 393       goto done;
 394     }
 395
 396   if (arg == NULL && (option->flags & (CL_JOINED | CL_SEPARATE)))
 397     {
 398       if (!(*lang_hooks.missing_argument) (opt, opt_index))
 399         error ("missing argument to \"%s\"", opt);
 400       goto done;
 401     }
 402
 403   /* If the switch takes an integer, convert it.  */
 404   if (arg && (option->flags & CL_UINTEGER))
 405     {
 406       value = integral_argument (arg);
 407       if (value == -1)
 408         {
 409           error ("argument to \"%s\" should be a non-negative integer",
 410                  option->opt_text);
 411           goto done;
 412         }
 413     }
 414
 415   if (option->flags & lang_mask)
 416     if ((*lang_hooks.handle_option) (opt_index, arg, value) == 0)
 417       result = 0;
 418
 419   if (result && (option->flags & CL_COMMON))
 420     if (common_handle_option (opt_index, arg, value) == 0)
 421       result = 0;
 422
 423  done:
 424   if (dup)
 425     free (dup);
 426   return result;
 427 }
 428
 429 /* Decode and handle the vector of command line options.  LANG_MASK
 430    contains has a single bit set representing the current
 431    language.  */
 432 static void
 433 handle_options (unsigned int argc, const char **argv, unsigned int lang_mask)
 434 {
 435   unsigned int n, i;
 436
 437   for (i = 1; i < argc; i += n)
 438     {
 439       const char *opt = argv[i];
 440
 441       /* Interpret "-" or a non-switch as a file name.  */
 442       if (opt[0] != '-' || opt[1] == '\0')
 443         {
 444           main_input_filename = opt;
 445           add_input_filename (opt);
 446           n = 1;
 447           continue;
 448         }
 449
 450       n = handle_option (argv + i, lang_mask);
 451
 452       if (!n)
 453         {
 454           n = 1;
 455           error ("unrecognized command line option \"%s\"", opt);
 456         }
 457     }
 458 }
 459
 460 /* Handle FILENAME from the command line.  */
 461 void
 462 add_input_filename (const char *filename)
 463 {
 464   num_in_fnames++;
 465   in_fnames = xrealloc (in_fnames, num_in_fnames * sizeof (in_fnames[0]));
 466   in_fnames[num_in_fnames - 1] = filename;
 467 }
 468
 469 /* Parse command line options and set default flag values.  Do minimal
 470    options processing.  */
 471 void
 472 decode_options (unsigned int argc, const char **argv)
 473 {
 474   unsigned int i, lang_mask;
 475
 476   /* Perform language-specific options initialization.  */
 477   lang_mask = (*lang_hooks.init_options) (argc, argv);
 478
 479   lang_hooks.initialize_diagnostics (global_dc);
 480
 481   /* Scan to see what optimization level has been specified.  That will
 482      determine the default value of many flags.  */
 483   for (i = 1; i < argc; i++)
 484     {
 485       if (!strcmp (argv[i], "-O"))
 486         {
 487           optimize = 1;
 488           optimize_size = 0;
 489         }
 490       else if (argv[i][0] == '-' && argv[i][1] == 'O')
 491         {
 492           /* Handle -Os, -O2, -O3, -O69, ...  */
 493           const char *p = &argv[i][2];
 494
 495           if ((p[0] == 's') && (p[1] == 0))
 496             {
 497               optimize_size = 1;
 498
 499               /* Optimizing for size forces optimize to be 2.  */
 500               optimize = 2;
 501             }
 502           else
 503             {
 504               const int optimize_val = read_integral_parameter (p, p - 2, -1);
 505               if (optimize_val != -1)
 506                 {
 507                   optimize = optimize_val;
 508                   optimize_size = 0;
 509                 }
 510             }
 511         }
 512     }
 513
 514   if (!optimize)
 515     {
 516       flag_merge_constants = 0;
 517     }
 518
 519   if (optimize >= 1)
 520     {
 521       flag_defer_pop = 1;
 522       flag_thread_jumps = 1;
 523 #ifdef DELAY_SLOTS
 524       flag_delayed_branch = 1;
 525 #endif
 526 #ifdef CAN_DEBUG_WITHOUT_FP
 527       flag_omit_frame_pointer = 1;
 528 #endif
 529       flag_guess_branch_prob = 1;
 530       flag_cprop_registers = 1;
 531       flag_loop_optimize = 1;
 532       flag_crossjumping = 1;
 533       flag_if_conversion = 1;
 534       flag_if_conversion2 = 1;
 535     }
 536
 537   if (optimize >= 2)
 538     {
 539       flag_optimize_sibling_calls = 1;
 540       flag_cse_follow_jumps = 1;
 541       flag_cse_skip_blocks = 1;
 542       flag_gcse = 1;
 543       flag_expensive_optimizations = 1;
 544       flag_strength_reduce = 1;
 545       flag_rerun_cse_after_loop = 1;
 546       flag_rerun_loop_opt = 1;
 547       flag_caller_saves = 1;
 548       flag_force_mem = 1;
 549       flag_peephole2 = 1;
 550 #ifdef INSN_SCHEDULING
 551       flag_schedule_insns = 1;
 552       flag_schedule_insns_after_reload = 1;
 553 #endif
 554       flag_regmove = 1;
 555       flag_strict_aliasing = 1;
 556       flag_delete_null_pointer_checks = 1;
 557       flag_reorder_blocks = 1;
 558       flag_reorder_functions = 1;
 559       flag_unit_at_a_time = 1;
 560     }
 561
 562   if (optimize >= 3)
 563     {
 564       flag_inline_functions = 1;
 565       flag_rename_registers = 1;
 566       flag_unswitch_loops = 1;
 567       flag_web = 1;
 568     }
 569
 570   if (optimize < 2 || optimize_size)
 571     {
 572       align_loops = 1;
 573       align_jumps = 1;
 574       align_labels = 1;
 575       align_functions = 1;
 576
 577       /* Don't reorder blocks when optimizing for size because extra
 578          jump insns may be created; also barrier may create extra padding.
 579
 580          More correctly we should have a block reordering mode that tried
 581          to minimize the combined size of all the jumps.  This would more
 582          or less automatically remove extra jumps, but would also try to
 583          use more short jumps instead of long jumps.  */
 584       flag_reorder_blocks = 0;
 585     }
 586
 587   /* Initialize whether `char' is signed.  */
 588   flag_signed_char = DEFAULT_SIGNED_CHAR;
 589 #ifdef DEFAULT_SHORT_ENUMS
 590   /* Initialize how much space enums occupy, by default.  */
 591   flag_short_enums = DEFAULT_SHORT_ENUMS;
 592 #endif
 593
 594   /* Initialize target_flags before OPTIMIZATION_OPTIONS so the latter can
 595      modify it.  */
 596   target_flags = 0;
 597   set_target_switch ("");
 598
 599   /* Unwind tables are always present in an ABI-conformant IA-64
 600      object file, so the default should be ON.  */
 601 #ifdef IA64_UNWIND_INFO
 602   flag_unwind_tables = IA64_UNWIND_INFO;
 603 #endif
 604
 605 #ifdef OPTIMIZATION_OPTIONS
 606   /* Allow default optimizations to be specified on a per-machine basis.  */
 607   OPTIMIZATION_OPTIONS (optimize, optimize_size);
 608 #endif
 609
 610   handle_options (argc, argv, lang_mask);
 611
 612   if (flag_pie)
 613     flag_pic = flag_pie;
 614   if (flag_pic && !flag_pie)
 615     flag_shlib = 1;
 616
 617   if (flag_no_inline == 2)
 618     flag_no_inline = 0;
 619   else
 620     flag_really_no_inline = flag_no_inline;
 621
 622   /* Set flag_no_inline before the post_options () hook.  The C front
 623      ends use it to determine tree inlining defaults.  FIXME: such
 624      code should be lang-independent when all front ends use tree
 625      inlining, in which case it, and this condition, should be moved
 626      to the top of process_options() instead.  */
 627   if (optimize == 0)
 628     {
 629       /* Inlining does not work if not optimizing,
 630          so force it not to be done.  */
 631       flag_no_inline = 1;
 632       warn_inline = 0;
 633
 634       /* The c_decode_option function and decode_option hook set
 635          this to `2' if -Wall is used, so we can avoid giving out
 636          lots of errors for people who don't realize what -Wall does.  */
 637       if (warn_uninitialized == 1)
 638         warning ("-Wuninitialized is not supported without -O");
 639     }
 640
 641   if (flag_really_no_inline == 2)
 642     flag_really_no_inline = flag_no_inline;
 643 }
 644
 645 /* Handle target- and language-independent options.  Return zero to
 646    generate an "unknown option" message.  */
 647 static int
 648 common_handle_option (size_t scode, const char *arg,
 649                       int value ATTRIBUTE_UNUSED)
 650 {
 651   enum opt_code code = (enum opt_code) scode;
 652
 653   switch (code)
 654     {
 655     default:
 656       abort ();
 657
 658     case OPT__help:
 659       print_help ();
 660       exit_after_options = true;
 661       break;
 662
 663     case OPT__param:
 664       handle_param (arg);
 665       break;
 666
 667     case OPT__target_help:
 668       display_target_options ();
 669       exit_after_options = true;
 670       break;
 671
 672     case OPT__version:
 673       print_version (stderr, "");
 674       exit_after_options = true;
 675       break;
 676
 677     case OPT_G:
 678       g_switch_value = value;
 679       g_switch_set = true;
 680       break;
 681
 682     case OPT_O:
 683     case OPT_Os:
 684       /* Currently handled in a prescan.  */
 685       break;
 686
 687     case OPT_W:
 688       /* For backward compatibility, -W is the same as -Wextra.  */
 689       set_Wextra (value);
 690       break;
 691
 692     case OPT_Waggregate_return:
 693       warn_aggregate_return = value;
 694       break;
 695
 696     case OPT_Wcast_align:
 697       warn_cast_align = value;
 698       break;
 699
 700     case OPT_Wdeprecated_declarations:
 701       warn_deprecated_decl = value;
 702       break;
 703
 704     case OPT_Wdisabled_optimization:
 705       warn_disabled_optimization = value;
 706       break;
 707
 708     case OPT_Werror:
 709       warnings_are_errors = value;
 710       break;
 711
 712     case OPT_Wextra:
 713       set_Wextra (value);
 714       break;
 715
 716     case OPT_Winline:
 717       warn_inline = value;
 718       break;
 719
 720     case OPT_Wlarger_than_:
 721       larger_than_size = value;
 722       warn_larger_than = value != -1;
 723       break;
 724
 725     case OPT_Wmissing_noreturn:
 726       warn_missing_noreturn = value;
 727       break;
 728
 729     case OPT_Wpacked:
 730       warn_packed = value;
 731       break;
 732
 733     case OPT_Wpadded:
 734       warn_padded = value;
 735       break;
 736
 737     case OPT_Wshadow:
 738       warn_shadow = value;
 739       break;
 740
 741     case OPT_Wstrict_aliasing:
 742       warn_strict_aliasing = value;
 743       break;
 744
 745     case OPT_Wswitch:
 746       warn_switch = value;
 747       break;
 748
 749     case OPT_Wswitch_default:
 750       warn_switch_default = value;
 751       break;
 752
 753     case OPT_Wswitch_enum:
 754       warn_switch_enum = value;
 755       break;
 756
 757     case OPT_Wsystem_headers:
 758       warn_system_headers = value;
 759       break;
 760
 761     case OPT_Wuninitialized:
 762       warn_uninitialized = value;
 763       break;
 764
 765     case OPT_Wunreachable_code:
 766       warn_notreached = value;
 767       break;
 768
 769     case OPT_Wunused:
 770       set_Wunused (value);
 771       break;
 772
 773     case OPT_Wunused_function:
 774       warn_unused_function = value;
 775       break;
 776
 777     case OPT_Wunused_label:
 778       warn_unused_label = value;
 779       break;
 780
 781     case OPT_Wunused_parameter:
 782       warn_unused_parameter = value;
 783       break;
 784
 785     case OPT_Wunused_value:
 786       warn_unused_value = value;
 787       break;
 788
 789     case OPT_Wunused_variable:
 790       warn_unused_variable = value;
 791       break;
 792
 793     case OPT_aux_info:
 794     case OPT_aux_info_:
 795       aux_info_file_name = arg;
 796       flag_gen_aux_info = 1;
 797       break;
 798
 799     case OPT_auxbase:
 800       aux_base_name = arg;
 801       break;
 802
 803     case OPT_auxbase_strip:
 804       {
 805         char *tmp = xstrdup (arg);
 806         strip_off_ending (tmp, strlen (tmp));
 807         if (tmp[0])
 808           aux_base_name = tmp;
 809       }
 810       break;
 811
 812     case OPT_d:
 813       decode_d_option (arg);
 814       break;
 815
 816     case OPT_dumpbase:
 817       dump_base_name = arg;
 818       break;
 819
 820     case OPT_fPIC:
 821       flag_pic = value + value;
 822       break;
 823
 824     case OPT_fPIE:
 825       flag_pie = value + value;
 826       break;
 827
 828     case OPT_falign_functions:
 829       align_functions = !value;
 830       break;
 831
 832     case OPT_falign_functions_:
 833       align_functions = value;
 834       break;
 835
 836     case OPT_falign_jumps:
 837       align_jumps = !value;
 838       break;
 839
 840     case OPT_falign_jumps_:
 841       align_jumps = value;
 842       break;
 843
 844     case OPT_falign_labels:
 845       align_labels = !value;
 846       break;
 847
 848     case OPT_falign_labels_:
 849       align_labels = value;
 850       break;
 851
 852     case OPT_falign_loops:
 853       align_loops = !value;
 854       break;
 855
 856     case OPT_falign_loops_:
 857       align_loops = value;
 858       break;
 859
 860     case OPT_fargument_alias:
 861       flag_argument_noalias = !value;
 862       break;
 863
 864     case OPT_fargument_noalias:
 865       flag_argument_noalias = value;
 866       break;
 867
 868     case OPT_fargument_noalias_global:
 869       flag_argument_noalias = value + value;
 870       break;
 871
 872     case OPT_fasynchronous_unwind_tables:
 873       flag_asynchronous_unwind_tables = value;
 874       break;
 875
 876     case OPT_fbounds_check:
 877       flag_bounds_check = value;
 878       break;
 879
 880     case OPT_fbranch_count_reg:
 881       flag_branch_on_count_reg = value;
 882       break;
 883
 884     case OPT_fbranch_probabilities:
 885       flag_branch_probabilities = value;
 886       break;
 887
 888     case OPT_fbranch_target_load_optimize:
 889       flag_branch_target_load_optimize = value;
 890       break;
 891
 892     case OPT_fbranch_target_load_optimize2:
 893       flag_branch_target_load_optimize2 = value;
 894       break;
 895
 896     case OPT_fcall_used_:
 897       fix_register (arg, 0, 1);
 898       break;
 899
 900     case OPT_fcall_saved_:
 901       fix_register (arg, 0, 0);
 902       break;
 903
 904     case OPT_fcaller_saves:
 905       flag_caller_saves = value;
 906       break;
 907
 908     case OPT_fcommon:
 909       flag_no_common = !value;
 910       break;
 911
 912     case OPT_fcprop_registers:
 913       flag_cprop_registers = value;
 914       break;
 915
 916     case OPT_fcrossjumping:
 917       flag_crossjumping = value;
 918       break;
 919
 920     case OPT_fcse_follow_jumps:
 921       flag_cse_follow_jumps = value;
 922       break;
 923
 924     case OPT_fcse_skip_blocks:
 925       flag_cse_skip_blocks = value;
 926       break;
 927
 928     case OPT_fdata_sections:
 929       flag_data_sections = value;
 930       break;
 931
 932     case OPT_fdefer_pop:
 933       flag_defer_pop = value;
 934       break;
 935
 936     case OPT_fdelayed_branch:
 937       flag_delayed_branch = value;
 938       break;
 939
 940     case OPT_fdelete_null_pointer_checks:
 941       flag_delete_null_pointer_checks = value;
 942       break;
 943
 944     case OPT_fdiagnostics_show_location_:
 945       if (!strcmp (arg, "once"))
 946         diagnostic_prefixing_rule (global_dc) = DIAGNOSTICS_SHOW_PREFIX_ONCE;
 947       else if (!strcmp (arg, "every-line"))
 948         diagnostic_prefixing_rule (global_dc)
 949           = DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE;
 950       else
 951         return 0;
 952       break;
 953
 954     case OPT_fdump_unnumbered:
 955       flag_dump_unnumbered = value;
 956       break;
 957
 958     case OPT_feliminate_dwarf2_dups:
 959       flag_eliminate_dwarf2_dups = value;
 960       break;
 961
 962     case OPT_feliminate_unused_debug_types:
 963       flag_eliminate_unused_debug_types = value;
 964       break;
 965
 966     case OPT_feliminate_unused_debug_symbols:
 967       flag_debug_only_used_symbols = value;
 968       break;
 969
 970     case OPT_fexceptions:
 971       flag_exceptions = value;
 972       break;
 973
 974     case OPT_fexpensive_optimizations:
 975       flag_expensive_optimizations = value;
 976       break;
 977
 978     case OPT_ffast_math:
 979       set_fast_math_flags (value);
 980       break;
 981
 982     case OPT_ffinite_math_only:
 983       flag_finite_math_only = value;
 984       break;
 985
 986     case OPT_ffixed_:
 987       fix_register (arg, 1, 1);
 988       break;
 989
 990     case OPT_ffunction_cse:
 991       flag_no_function_cse = !value;
 992       break;
 993
 994     case OPT_ffloat_store:
 995       flag_float_store = value;
 996       break;
 997
 998     case OPT_fforce_addr:
 999       flag_force_addr = value;
1000       break;
1001
1002     case OPT_fforce_mem:
1003       flag_force_mem = value;
1004       break;
1005
1006     case OPT_ffunction_sections:
1007       flag_function_sections = value;
1008       break;
1009
1010     case OPT_fgcse:
1011       flag_gcse = value;
1012       break;
1013
1014     case OPT_fgcse_lm:
1015       flag_gcse_lm = value;
1016       break;
1017
1018     case OPT_fgcse_sm:
1019       flag_gcse_sm = value;
1020       break;
1021
1022     case OPT_fgcse_las:
1023       flag_gcse_las = value;
1024       break;
1025
1026     case OPT_fguess_branch_probability:
1027       flag_guess_branch_prob = value;
1028       break;
1029
1030     case OPT_fident:
1031       flag_no_ident = !value;
1032       break;
1033
1034     case OPT_fif_conversion:
1035       flag_if_conversion = value;
1036       break;
1037
1038     case OPT_fif_conversion2:
1039       flag_if_conversion2 = value;
1040       break;
1041
1042     case OPT_finhibit_size_directive:
1043       flag_inhibit_size_directive = value;
1044       break;
1045
1046     case OPT_finline:
1047       flag_no_inline = !value;
1048       break;
1049
1050     case OPT_finline_functions:
1051       flag_inline_functions = value;
1052       break;
1053
1054     case OPT_finline_limit_:
1055     case OPT_finline_limit_eq:
1056       set_param_value ("max-inline-insns-single", value / 2);
1057       set_param_value ("max-inline-insns-auto", value / 2);
1058       set_param_value ("max-inline-insns-rtl", value);
1059       break;
1060
1061     case OPT_finstrument_functions:
1062       flag_instrument_function_entry_exit = value;
1063       break;
1064
1065     case OPT_fkeep_inline_functions:
1066       flag_keep_inline_functions =value;
1067       break;
1068
1069     case OPT_fkeep_static_consts:
1070       flag_keep_static_consts = value;
1071       break;
1072
1073     case OPT_fleading_underscore:
1074       flag_leading_underscore = value;
1075       break;
1076
1077     case OPT_floop_optimize:
1078       flag_loop_optimize = value;
1079       break;
1080
1081     case OPT_fmath_errno:
1082       flag_errno_math = value;
1083       break;
1084
1085     case OPT_fmem_report:
1086       mem_report = value;
1087       break;
1088
1089     case OPT_fmerge_all_constants:
1090       flag_merge_constants = value + value;
1091       break;
1092
1093     case OPT_fmerge_constants:
1094       flag_merge_constants = value;
1095       break;
1096
1097     case OPT_fmessage_length_:
1098       pp_set_line_maximum_length (global_dc->printer, value);
1099       break;
1100
1101     case OPT_fmove_all_movables:
1102       flag_move_all_movables = value;
1103       break;
1104
1105     case OPT_fnew_ra:
1106       flag_new_regalloc = value;
1107       break;
1108
1109     case OPT_fnon_call_exceptions:
1110       flag_non_call_exceptions = value;
1111       break;
1112
1113     case OPT_fold_unroll_all_loops:
1114       flag_old_unroll_all_loops = value;
1115       break;
1116
1117     case OPT_fold_unroll_loops:
1118       flag_old_unroll_loops = value;
1119       break;
1120
1121     case OPT_fomit_frame_pointer:
1122       flag_omit_frame_pointer = value;
1123       break;
1124
1125     case OPT_foptimize_register_move:
1126       flag_regmove = value;
1127       break;
1128
1129     case OPT_foptimize_sibling_calls:
1130       flag_optimize_sibling_calls = value;
1131       break;
1132
1133     case OPT_fpack_struct:
1134       flag_pack_struct = value;
1135       break;
1136
1137     case OPT_fpeel_loops:
1138       flag_peel_loops = value;
1139       break;
1140
1141     case OPT_fpcc_struct_return:
1142       flag_pcc_struct_return = value;
1143       break;
1144
1145     case OPT_fpeephole:
1146       flag_no_peephole = !value;
1147       break;
1148
1149     case OPT_fpeephole2:
1150       flag_peephole2 = value;
1151       break;
1152
1153     case OPT_fpic:
1154       flag_pic = value;
1155       break;
1156
1157     case OPT_fpie:
1158       flag_pie = value;
1159       break;
1160
1161     case OPT_fprefetch_loop_arrays:
1162       flag_prefetch_loop_arrays = value;
1163       break;
1164
1165     case OPT_fprofile:
1166       profile_flag = value;
1167       break;
1168
1169     case OPT_fprofile_arcs:
1170       profile_arc_flag = value;
1171       break;
1172
1173     case OPT_fprofile_values:
1174       flag_profile_values = value;
1175       break;
1176
1177     case OPT_fvpt:
1178       flag_value_profile_transformations = value;
1179       break;
1180
1181     case OPT_frandom_seed:
1182       /* The real switch is -fno-random-seed.  */
1183       if (value)
1184         return 0;
1185       flag_random_seed = NULL;
1186       break;
1187
1188     case OPT_frandom_seed_:
1189       flag_random_seed = arg;
1190       break;
1191
1192     case OPT_freduce_all_givs:
1193       flag_reduce_all_givs = value;
1194       break;
1195
1196     case OPT_freg_struct_return:
1197       flag_pcc_struct_return = !value;
1198       break;
1199
1200     case OPT_fregmove:
1201       flag_regmove = value;
1202       break;
1203
1204     case OPT_frename_registers:
1205       flag_rename_registers = value;
1206       break;
1207
1208     case OPT_freorder_blocks:
1209       flag_reorder_blocks = value;
1210       break;
1211
1212     case OPT_freorder_functions:
1213       flag_reorder_functions = value;
1214       break;
1215
1216     case OPT_frerun_cse_after_loop:
1217       flag_rerun_cse_after_loop = value;
1218       break;
1219
1220     case OPT_frerun_loop_opt:
1221       flag_rerun_loop_opt = value;
1222       break;
1223
1224     case OPT_frounding_math:
1225       flag_rounding_math = value;
1226       break;
1227
1228     case OPT_fsched_interblock:
1229       flag_schedule_interblock = value;
1230       break;
1231
1232     case OPT_fsched_spec:
1233       flag_schedule_speculative = value;
1234       break;
1235
1236     case OPT_fsched_spec_load:
1237       flag_schedule_speculative_load = value;
1238       break;
1239
1240     case OPT_fsched_spec_load_dangerous:
1241       flag_schedule_speculative_load_dangerous = value;
1242       break;
1243
1244     case OPT_fsched_verbose_:
1245 #ifdef INSN_SCHEDULING
1246       fix_sched_param ("verbose", arg);
1247       break;
1248 #else
1249       return 0;
1250 #endif
1251
1252     case OPT_fsched2_use_superblocks:
1253       flag_sched2_use_superblocks = value;
1254       break;
1255
1256     case OPT_fsched2_use_traces:
1257       flag_sched2_use_traces = value;
1258       break;
1259
1260     case OPT_fschedule_insns:
1261       flag_schedule_insns = value;
1262       break;
1263
1264     case OPT_fschedule_insns2:
1265       flag_schedule_insns_after_reload = value;
1266       break;
1267
1268     case OPT_fsched_stalled_insns:
1269       flag_sched_stalled_insns = value;
1270       break;
1271
1272     case OPT_fsched_stalled_insns_:
1273       flag_sched_stalled_insns = value;
1274       if (flag_sched_stalled_insns == 0)
1275         flag_sched_stalled_insns = -1;
1276       break;
1277
1278     case OPT_fsched_stalled_insns_dep:
1279       flag_sched_stalled_insns_dep = 1;
1280       break;
1281
1282     case OPT_fsched_stalled_insns_dep_:
1283       flag_sched_stalled_insns_dep = value;
1284       break;
1285
1286     case OPT_fshared_data:
1287       flag_shared_data = value;
1288       break;
1289
1290     case OPT_fsignaling_nans:
1291       flag_signaling_nans = value;
1292       break;
1293
1294     case OPT_fsingle_precision_constant:
1295       flag_single_precision_constant = value;
1296       break;
1297
1298     case OPT_fstack_check:
1299       flag_stack_check = value;
1300       break;
1301
1302     case OPT_fstack_limit:
1303       /* The real switch is -fno-stack-limit.  */
1304       if (value)
1305         return 0;
1306       stack_limit_rtx = NULL_RTX;
1307       break;
1308
1309     case OPT_fstack_limit_register_:
1310       {
1311         int reg = decode_reg_name (arg);
1312         if (reg < 0)
1313           error ("unrecognized register name \"%s\"", arg);
1314         else
1315           stack_limit_rtx = gen_rtx_REG (Pmode, reg);
1316       }
1317       break;
1318
1319     case OPT_fstack_limit_symbol_:
1320       stack_limit_rtx = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (arg));
1321       break;
1322
1323     case OPT_fstrength_reduce:
1324       flag_strength_reduce = value;
1325       break;
1326
1327     case OPT_fstrict_aliasing:
1328       flag_strict_aliasing = value;
1329       break;
1330
1331     case OPT_fsyntax_only:
1332       flag_syntax_only = value;
1333       break;
1334
1335     case OPT_ftest_coverage:
1336       flag_test_coverage = value;
1337       break;
1338
1339     case OPT_fthread_jumps:
1340       flag_thread_jumps = value;
1341       break;
1342
1343     case OPT_ftime_report:
1344       time_report = value;
1345       break;
1346
1347     case OPT_ftls_model_:
1348       if (!strcmp (arg, "global-dynamic"))
1349         flag_tls_default = TLS_MODEL_GLOBAL_DYNAMIC;
1350       else if (!strcmp (arg, "local-dynamic"))
1351         flag_tls_default = TLS_MODEL_LOCAL_DYNAMIC;
1352       else if (!strcmp (arg, "initial-exec"))
1353         flag_tls_default = TLS_MODEL_INITIAL_EXEC;
1354       else if (!strcmp (arg, "local-exec"))
1355         flag_tls_default = TLS_MODEL_LOCAL_EXEC;
1356       else
1357         warning ("unknown tls-model \"%s\"", arg);
1358       break;
1359
1360     case OPT_ftracer:
1361       flag_tracer = value;
1362       break;
1363
1364     case OPT_ftrapping_math:
1365       flag_trapping_math = value;
1366       break;
1367
1368     case OPT_ftrapv:
1369       flag_trapv = value;
1370       break;
1371
1372     case OPT_funit_at_a_time:
1373       flag_unit_at_a_time = value;
1374       break;
1375
1376     case OPT_funroll_all_loops:
1377       flag_unroll_all_loops = value;
1378       break;
1379
1380     case OPT_funroll_loops:
1381       flag_unroll_loops = value;
1382       break;
1383
1384     case OPT_funsafe_math_optimizations:
1385       flag_unsafe_math_optimizations = value;
1386       break;
1387
1388     case OPT_funswitch_loops:
1389       flag_unswitch_loops = value;
1390       break;
1391
1392     case OPT_funwind_tables:
1393       flag_unwind_tables = value;
1394       break;
1395
1396     case OPT_fverbose_asm:
1397       flag_verbose_asm = value;
1398       break;
1399
1400     case OPT_fweb:
1401       flag_web = value;
1402       break;
1403
1404     case OPT_fwrapv:
1405       flag_wrapv = value;
1406       break;
1407
1408     case OPT_fwritable_strings:
1409       flag_writable_strings = value;
1410       break;
1411
1412     case OPT_fzero_initialized_in_bss:
1413       flag_zero_initialized_in_bss = value;
1414       break;
1415
1416     case OPT_g:
1417       set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg);
1418       break;
1419
1420     case OPT_gcoff:
1421       set_debug_level (SDB_DEBUG, false, arg);
1422       break;
1423
1424     case OPT_gdwarf:
1425       if (*arg)
1426         {
1427           error ("use -gdwarf -gN for DWARF v1 level N, "
1428                  "and -gdwarf-2 for DWARF v2" );
1429           break;
1430         }
1431
1432       /* Fall through.  */
1433     case OPT_gdwarf_:
1434       set_debug_level (DWARF_DEBUG, code == OPT_gdwarf_, arg);
1435       break;
1436
1437     case OPT_gdwarf_2:
1438       set_debug_level (DWARF2_DEBUG, false, arg);
1439       break;
1440
1441     case OPT_ggdb:
1442       set_debug_level (NO_DEBUG, 2, arg);
1443       break;
1444
1445     case OPT_gstabs:
1446     case OPT_gstabs_:
1447       set_debug_level (DBX_DEBUG, code == OPT_gstabs_, arg);
1448       break;
1449
1450     case OPT_gvms:
1451       set_debug_level (VMS_DEBUG, false, arg);
1452       break;
1453
1454     case OPT_gxcoff:
1455     case OPT_gxcoff_:
1456       set_debug_level (XCOFF_DEBUG, code == OPT_gxcoff_, arg);
1457       break;
1458
1459     case OPT_m:
1460       set_target_switch (arg);
1461       break;
1462
1463     case OPT_o:
1464       asm_file_name = arg;
1465       break;
1466
1467     case OPT_p:
1468       profile_flag = 1;
1469       break;
1470
1471     case OPT_pedantic:
1472       pedantic = 1;
1473       break;
1474
1475     case OPT_pedantic_errors:
1476       flag_pedantic_errors = pedantic = 1;
1477       break;
1478
1479     case OPT_quiet:
1480       quiet_flag = 1;
1481       break;
1482
1483     case OPT_version:
1484       version_flag = 1;
1485       break;
1486
1487     case OPT_w:
1488       inhibit_warnings = true;
1489       break;
1490     }
1491
1492   return 1;
1493 }
1494
1495 /* Handle --param NAME=VALUE.  */
1496 static void
1497 handle_param (const char *carg)
1498 {
1499   char *equal, *arg;
1500   int value;
1501
1502   arg = xstrdup (carg);
1503   equal = strchr (arg, '=');
1504   if (!equal)
1505     error ("%s: --param arguments should be of the form NAME=VALUE", arg);
1506   else
1507     {
1508       value = integral_argument (equal + 1);
1509       if (value == -1)
1510         error ("invalid --param value `%s'", equal + 1);
1511       else
1512         {
1513           *equal = '\0';
1514           set_param_value (arg, value);
1515         }
1516     }
1517
1518   free (arg);
1519 }
1520
1521 /* Handle -W and -Wextra.  */
1522 static void
1523 set_Wextra (int setting)
1524 {
1525   extra_warnings = setting;
1526   warn_unused_value = setting;
1527   warn_unused_parameter = (setting && maybe_warn_unused_parameter);
1528
1529   /* We save the value of warn_uninitialized, since if they put
1530      -Wuninitialized on the command line, we need to generate a
1531      warning about not using it without also specifying -O.  */
1532   if (setting == 0)
1533     warn_uninitialized = 0;
1534   else if (warn_uninitialized != 1)
1535     warn_uninitialized = 2;
1536 }
1537
1538 /* Initialize unused warning flags.  */
1539 void
1540 set_Wunused (int setting)
1541 {
1542   warn_unused_function = setting;
1543   warn_unused_label = setting;
1544   /* Unused function parameter warnings are reported when either
1545      ``-Wextra -Wunused'' or ``-Wunused-parameter'' is specified.
1546      Thus, if -Wextra has already been seen, set warn_unused_parameter;
1547      otherwise set maybe_warn_extra_parameter, which will be picked up
1548      by set_Wextra.  */
1549   maybe_warn_unused_parameter = setting;
1550   warn_unused_parameter = (setting && extra_warnings);
1551   warn_unused_variable = setting;
1552   warn_unused_value = setting;
1553 }
1554
1555 /* The following routines are useful in setting all the flags that
1556    -ffast-math and -fno-fast-math imply.  */
1557 void
1558 set_fast_math_flags (int set)
1559 {
1560   flag_trapping_math = !set;
1561   flag_unsafe_math_optimizations = set;
1562   flag_finite_math_only = set;
1563   flag_errno_math = !set;
1564   if (set)
1565     {
1566       flag_signaling_nans = 0;
1567       flag_rounding_math = 0;
1568     }
1569 }
1570
1571 /* Return true iff flags are set as if -ffast-math.  */
1572 bool
1573 fast_math_flags_set_p (void)
1574 {
1575   return (!flag_trapping_math
1576           && flag_unsafe_math_optimizations
1577           && flag_finite_math_only
1578           && !flag_errno_math);
1579 }
1580
1581 /* Handle a debug output -g switch.  EXTENDED is true or false to support
1582    extended output (2 is special and means "-ggdb" was given).  */
1583 static void
1584 set_debug_level (enum debug_info_type type, int extended, const char *arg)
1585 {
1586   static bool type_explicit;
1587
1588   use_gnu_debug_info_extensions = extended;
1589
1590   if (type == NO_DEBUG)
1591     {
1592       if (write_symbols == NO_DEBUG)
1593         {
1594           write_symbols = PREFERRED_DEBUGGING_TYPE;
1595
1596           if (extended == 2)
1597             {
1598 #ifdef DWARF2_DEBUGGING_INFO
1599               write_symbols = DWARF2_DEBUG;
1600 #elif defined DBX_DEBUGGING_INFO
1601               write_symbols = DBX_DEBUG;
1602 #endif
1603             }
1604
1605           if (write_symbols == NO_DEBUG)
1606             warning ("target system does not support debug output");
1607         }
1608     }
1609   else
1610     {
1611       /* Does it conflict with an already selected type?  */
1612       if (type_explicit && write_symbols != NO_DEBUG && type != write_symbols)
1613         error ("debug format \"%s\" conflicts with prior selection",
1614                debug_type_names[type]);
1615       write_symbols = type;
1616       type_explicit = true;
1617     }
1618
1619   /* A debug flag without a level defaults to level 2.  */
1620   if (*arg == '\0')
1621     {
1622       if (!debug_info_level)
1623         debug_info_level = 2;
1624     }
1625   else
1626     {
1627       debug_info_level = integral_argument (arg);
1628       if (debug_info_level == (unsigned int) -1)
1629         error ("unrecognised debug output level \"%s\"", arg);
1630       else if (debug_info_level > 3)
1631         error ("debug output level %s is too high", arg);
1632     }
1633 }
1634
1635 /* Output --help text.  */
1636 static void
1637 print_help (void)
1638 {
1639   size_t i;
1640   const char *p;
1641
1642   GET_ENVIRONMENT (p, "COLUMNS");
1643   if (p)
1644     {
1645       int value = atoi (p);
1646       if (value > 0)
1647         columns = value;
1648     }
1649
1650   puts (_("The following options are language-independent:\n"));
1651
1652   print_filtered_help (CL_COMMON);
1653   print_param_help ();
1654
1655   for (i = 0; lang_names[i]; i++)
1656     {
1657       printf (_("The %s front end recognizes the following options:\n\n"),
1658               lang_names[i]);
1659       print_filtered_help (1U << i);
1660     }
1661
1662   display_target_options ();
1663 }
1664
1665 /* Print the help for --param.  */
1666 static void
1667 print_param_help (void)
1668 {
1669   size_t i;
1670
1671   puts (_("The --param option recognizes the following as parameters:\n"));
1672
1673   for (i = 0; i < LAST_PARAM; i++)
1674     {
1675       const char *help = compiler_params[i].help;
1676       const char *param = compiler_params[i].option;
1677
1678       if (help == NULL || *help == '\0')
1679         help = undocumented_msg;
1680
1681       /* Get the translation.  */
1682       help = _(help);
1683
1684       wrap_help (help, param, strlen (param));
1685     }
1686
1687   putchar ('\n');
1688 }
1689
1690 /* Print help for a specific front-end, etc.  */
1691 static void
1692 print_filtered_help (unsigned int flag)
1693 {
1694   unsigned int i, len, filter, indent = 0;
1695   bool duplicates = false;
1696   const char *help, *opt, *tab;
1697   static char *printed;
1698
1699   if (flag == CL_COMMON)
1700     {
1701       filter = flag;
1702       if (!printed)
1703         printed = xmalloc (cl_options_count);
1704       memset (printed, 0, cl_options_count);
1705     }
1706   else
1707     {
1708       /* Don't print COMMON options twice.  */
1709       filter = flag | CL_COMMON;
1710
1711       for (i = 0; i < cl_options_count; i++)
1712         {
1713           if ((cl_options[i].flags & filter) != flag)
1714             continue;
1715
1716           /* Skip help for internal switches.  */
1717           if (cl_options[i].flags & CL_UNDOCUMENTED)
1718             continue;
1719
1720           /* Skip switches that have already been printed, mark them to be
1721              listed later.  */
1722           if (printed[i])
1723             {
1724               duplicates = true;
1725               indent = print_switch (cl_options[i].opt_text, indent);
1726             }
1727         }
1728
1729       if (duplicates)
1730         {
1731           putchar ('\n');
1732           putchar ('\n');
1733         }
1734     }
1735
1736   for (i = 0; i < cl_options_count; i++)
1737     {
1738       if ((cl_options[i].flags & filter) != flag)
1739         continue;
1740
1741       /* Skip help for internal switches.  */
1742       if (cl_options[i].flags & CL_UNDOCUMENTED)
1743         continue;
1744
1745       /* Skip switches that have already been printed.  */
1746       if (printed[i])
1747         continue;
1748
1749       printed[i] = true;
1750
1751       help = cl_options[i].help;
1752       if (!help)
1753         help = undocumented_msg;
1754
1755       /* Get the translation.  */
1756       help = _(help);
1757
1758       tab = strchr (help, '\t');
1759       if (tab)
1760         {
1761           len = tab - help;
1762           opt = help;
1763           help = tab + 1;
1764         }
1765       else
1766         {
1767           opt = cl_options[i].opt_text;
1768           len = strlen (opt);
1769         }
1770
1771       wrap_help (help, opt, len);
1772     }
1773
1774   putchar ('\n');
1775 }
1776
1777 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1778    word-wrapped HELP in a second column.  */
1779 static unsigned int
1780 print_switch (const char *text, unsigned int indent)
1781 {
1782   unsigned int len = strlen (text) + 1; /* trailing comma */
1783
1784   if (indent)
1785     {
1786       putchar (',');
1787       if (indent + len > columns)
1788         {
1789           putchar ('\n');
1790           putchar (' ');
1791           indent = 1;
1792         }
1793     }
1794   else
1795     putchar (' ');
1796
1797   putchar (' ');
1798   fputs (text, stdout);
1799
1800   return indent + len + 1;
1801 }
1802
1803 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1804    word-wrapped HELP in a second column.  */
1805 static void
1806 wrap_help (const char *help, const char *item, unsigned int item_width)
1807 {
1808   unsigned int col_width = 27;
1809   unsigned int remaining, room, len;
1810
1811   remaining = strlen (help);
1812
1813   do
1814     {
1815       room = columns - 3 - MAX (col_width, item_width);
1816       if (room > columns)
1817         room = 0;
1818       len = remaining;
1819
1820       if (room < len)
1821         {
1822           unsigned int i;
1823
1824           for (i = 0; help[i]; i++)
1825             {
1826               if (i >= room && len != remaining)
1827                 break;
1828               if (help[i] == ' ')
1829                 len = i;
1830               else if ((help[i] == '-' || help[i] == '/')
1831                        && help[i + 1] != ' '
1832                        && ISALPHA (help[i - 1]))
1833                 len = i + 1;
1834             }
1835         }
1836
1837       printf( "  %-*.*s %.*s\n", col_width, item_width, item, len, help);
1838       item_width = 0;
1839       while (help[len] == ' ')
1840         len++;
1841       help += len;
1842       remaining -= len;
1843     }
1844   while (remaining);
1845 }