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_fgnu_linker:
1027       flag_gnu_linker = value;
1028       break;
1029
1030     case OPT_fguess_branch_probability:
1031       flag_guess_branch_prob = value;
1032       break;
1033
1034     case OPT_fident:
1035       flag_no_ident = !value;
1036       break;
1037
1038     case OPT_fif_conversion:
1039       flag_if_conversion = value;
1040       break;
1041
1042     case OPT_fif_conversion2:
1043       flag_if_conversion2 = value;
1044       break;
1045
1046     case OPT_finhibit_size_directive:
1047       flag_inhibit_size_directive = value;
1048       break;
1049
1050     case OPT_finline:
1051       flag_no_inline = !value;
1052       break;
1053
1054     case OPT_finline_functions:
1055       flag_inline_functions = value;
1056       break;
1057
1058     case OPT_finline_limit_:
1059     case OPT_finline_limit_eq:
1060       set_param_value ("max-inline-insns", value);
1061       set_param_value ("max-inline-insns-single", value / 2);
1062       set_param_value ("max-inline-insns-auto", value / 2);
1063       set_param_value ("max-inline-insns-rtl", value);
1064       break;
1065
1066     case OPT_finstrument_functions:
1067       flag_instrument_function_entry_exit = value;
1068       break;
1069
1070     case OPT_fkeep_inline_functions:
1071       flag_keep_inline_functions =value;
1072       break;
1073
1074     case OPT_fkeep_static_consts:
1075       flag_keep_static_consts = value;
1076       break;
1077
1078     case OPT_fleading_underscore:
1079       flag_leading_underscore = value;
1080       break;
1081
1082     case OPT_floop_optimize:
1083       flag_loop_optimize = value;
1084       break;
1085
1086     case OPT_fmath_errno:
1087       flag_errno_math = value;
1088       break;
1089
1090     case OPT_fmem_report:
1091       mem_report = value;
1092       break;
1093
1094     case OPT_fmerge_all_constants:
1095       flag_merge_constants = value + value;
1096       break;
1097
1098     case OPT_fmerge_constants:
1099       flag_merge_constants = value;
1100       break;
1101
1102     case OPT_fmessage_length_:
1103       pp_set_line_maximum_length (global_dc->printer, value);
1104       break;
1105
1106     case OPT_fmove_all_movables:
1107       flag_move_all_movables = value;
1108       break;
1109
1110     case OPT_fnew_ra:
1111       flag_new_regalloc = value;
1112       break;
1113
1114     case OPT_fnon_call_exceptions:
1115       flag_non_call_exceptions = value;
1116       break;
1117
1118     case OPT_fold_unroll_all_loops:
1119       flag_old_unroll_all_loops = value;
1120       break;
1121
1122     case OPT_fold_unroll_loops:
1123       flag_old_unroll_loops = value;
1124       break;
1125
1126     case OPT_fomit_frame_pointer:
1127       flag_omit_frame_pointer = value;
1128       break;
1129
1130     case OPT_foptimize_register_move:
1131       flag_regmove = value;
1132       break;
1133
1134     case OPT_foptimize_sibling_calls:
1135       flag_optimize_sibling_calls = value;
1136       break;
1137
1138     case OPT_fpack_struct:
1139       flag_pack_struct = value;
1140       break;
1141
1142     case OPT_fpeel_loops:
1143       flag_peel_loops = value;
1144       break;
1145
1146     case OPT_fpcc_struct_return:
1147       flag_pcc_struct_return = value;
1148       break;
1149
1150     case OPT_fpeephole:
1151       flag_no_peephole = !value;
1152       break;
1153
1154     case OPT_fpeephole2:
1155       flag_peephole2 = value;
1156       break;
1157
1158     case OPT_fpic:
1159       flag_pic = value;
1160       break;
1161
1162     case OPT_fpie:
1163       flag_pie = value;
1164       break;
1165
1166     case OPT_fprefetch_loop_arrays:
1167       flag_prefetch_loop_arrays = value;
1168       break;
1169
1170     case OPT_fprofile:
1171       profile_flag = value;
1172       break;
1173
1174     case OPT_fprofile_arcs:
1175       profile_arc_flag = value;
1176       break;
1177
1178     case OPT_fprofile_values:
1179       flag_profile_values = value;
1180       break;
1181
1182     case OPT_fvpt:
1183       flag_value_profile_transformations = value;
1184       break;
1185
1186     case OPT_frandom_seed:
1187       /* The real switch is -fno-random-seed.  */
1188       if (value)
1189         return 0;
1190       flag_random_seed = NULL;
1191       break;
1192
1193     case OPT_frandom_seed_:
1194       flag_random_seed = arg;
1195       break;
1196
1197     case OPT_freduce_all_givs:
1198       flag_reduce_all_givs = value;
1199       break;
1200
1201     case OPT_freg_struct_return:
1202       flag_pcc_struct_return = !value;
1203       break;
1204
1205     case OPT_fregmove:
1206       flag_regmove = value;
1207       break;
1208
1209     case OPT_frename_registers:
1210       flag_rename_registers = value;
1211       break;
1212
1213     case OPT_freorder_blocks:
1214       flag_reorder_blocks = value;
1215       break;
1216
1217     case OPT_freorder_functions:
1218       flag_reorder_functions = value;
1219       break;
1220
1221     case OPT_frerun_cse_after_loop:
1222       flag_rerun_cse_after_loop = value;
1223       break;
1224
1225     case OPT_frerun_loop_opt:
1226       flag_rerun_loop_opt = value;
1227       break;
1228
1229     case OPT_frounding_math:
1230       flag_rounding_math = value;
1231       break;
1232
1233     case OPT_fsched_interblock:
1234       flag_schedule_interblock = value;
1235       break;
1236
1237     case OPT_fsched_spec:
1238       flag_schedule_speculative = value;
1239       break;
1240
1241     case OPT_fsched_spec_load:
1242       flag_schedule_speculative_load = value;
1243       break;
1244
1245     case OPT_fsched_spec_load_dangerous:
1246       flag_schedule_speculative_load_dangerous = value;
1247       break;
1248
1249     case OPT_fsched_verbose_:
1250 #ifdef INSN_SCHEDULING
1251       fix_sched_param ("verbose", arg);
1252       break;
1253 #else
1254       return 0;
1255 #endif
1256
1257     case OPT_fsched2_use_superblocks:
1258       flag_sched2_use_superblocks = value;
1259       break;
1260
1261     case OPT_fsched2_use_traces:
1262       flag_sched2_use_traces = value;
1263       break;
1264
1265     case OPT_fschedule_insns:
1266       flag_schedule_insns = value;
1267       break;
1268
1269     case OPT_fschedule_insns2:
1270       flag_schedule_insns_after_reload = value;
1271       break;
1272
1273     case OPT_fsched_stalled_insns:
1274       flag_sched_stalled_insns = value;
1275       break;
1276
1277     case OPT_fsched_stalled_insns_:
1278       flag_sched_stalled_insns = value;
1279       if (flag_sched_stalled_insns == 0)
1280         flag_sched_stalled_insns = -1;
1281       break;
1282
1283     case OPT_fsched_stalled_insns_dep:
1284       flag_sched_stalled_insns_dep = 1;
1285       break;
1286
1287     case OPT_fsched_stalled_insns_dep_:
1288       flag_sched_stalled_insns_dep = value;
1289       break;
1290
1291     case OPT_fshared_data:
1292       flag_shared_data = value;
1293       break;
1294
1295     case OPT_fsignaling_nans:
1296       flag_signaling_nans = value;
1297       break;
1298
1299     case OPT_fsingle_precision_constant:
1300       flag_single_precision_constant = value;
1301       break;
1302
1303     case OPT_fssa:
1304       flag_ssa = value;
1305       break;
1306
1307     case OPT_fssa_ccp:
1308       flag_ssa_ccp = value;
1309       break;
1310
1311     case OPT_fssa_dce:
1312       flag_ssa_dce = value;
1313       break;
1314
1315     case OPT_fstack_check:
1316       flag_stack_check = value;
1317       break;
1318
1319     case OPT_fstack_limit:
1320       /* The real switch is -fno-stack-limit.  */
1321       if (value)
1322         return 0;
1323       stack_limit_rtx = NULL_RTX;
1324       break;
1325
1326     case OPT_fstack_limit_register_:
1327       {
1328         int reg = decode_reg_name (arg);
1329         if (reg < 0)
1330           error ("unrecognized register name \"%s\"", arg);
1331         else
1332           stack_limit_rtx = gen_rtx_REG (Pmode, reg);
1333       }
1334       break;
1335
1336     case OPT_fstack_limit_symbol_:
1337       stack_limit_rtx = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (arg));
1338       break;
1339
1340     case OPT_fstrength_reduce:
1341       flag_strength_reduce = value;
1342       break;
1343
1344     case OPT_fstrict_aliasing:
1345       flag_strict_aliasing = value;
1346       break;
1347
1348     case OPT_fsyntax_only:
1349       flag_syntax_only = value;
1350       break;
1351
1352     case OPT_ftest_coverage:
1353       flag_test_coverage = value;
1354       break;
1355
1356     case OPT_fthread_jumps:
1357       flag_thread_jumps = value;
1358       break;
1359
1360     case OPT_ftime_report:
1361       time_report = value;
1362       break;
1363
1364     case OPT_ftls_model_:
1365       if (!strcmp (arg, "global-dynamic"))
1366         flag_tls_default = TLS_MODEL_GLOBAL_DYNAMIC;
1367       else if (!strcmp (arg, "local-dynamic"))
1368         flag_tls_default = TLS_MODEL_LOCAL_DYNAMIC;
1369       else if (!strcmp (arg, "initial-exec"))
1370         flag_tls_default = TLS_MODEL_INITIAL_EXEC;
1371       else if (!strcmp (arg, "local-exec"))
1372         flag_tls_default = TLS_MODEL_LOCAL_EXEC;
1373       else
1374         warning ("unknown tls-model \"%s\"", arg);
1375       break;
1376
1377     case OPT_ftracer:
1378       flag_tracer = value;
1379       break;
1380
1381     case OPT_ftrapping_math:
1382       flag_trapping_math = value;
1383       break;
1384
1385     case OPT_ftrapv:
1386       flag_trapv = value;
1387       break;
1388
1389     case OPT_funit_at_a_time:
1390       flag_unit_at_a_time = value;
1391       break;
1392
1393     case OPT_funroll_all_loops:
1394       flag_unroll_all_loops = value;
1395       break;
1396
1397     case OPT_funroll_loops:
1398       flag_unroll_loops = value;
1399       break;
1400
1401     case OPT_funsafe_math_optimizations:
1402       flag_unsafe_math_optimizations = value;
1403       break;
1404
1405     case OPT_funswitch_loops:
1406       flag_unswitch_loops = value;
1407       break;
1408
1409     case OPT_funwind_tables:
1410       flag_unwind_tables = value;
1411       break;
1412
1413     case OPT_fverbose_asm:
1414       flag_verbose_asm = value;
1415       break;
1416
1417     case OPT_fweb:
1418       flag_web = value;
1419       break;
1420
1421     case OPT_fwrapv:
1422       flag_wrapv = value;
1423       break;
1424
1425     case OPT_fwritable_strings:
1426       flag_writable_strings = value;
1427       break;
1428
1429     case OPT_fzero_initialized_in_bss:
1430       flag_zero_initialized_in_bss = value;
1431       break;
1432
1433     case OPT_g:
1434       set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg);
1435       break;
1436
1437     case OPT_gcoff:
1438       set_debug_level (SDB_DEBUG, false, arg);
1439       break;
1440
1441     case OPT_gdwarf:
1442       if (*arg)
1443         {
1444           error ("use -gdwarf -gN for DWARF v1 level N, "
1445                  "and -gdwarf-2 for DWARF v2" );
1446           break;
1447         }
1448
1449       /* Fall through.  */
1450     case OPT_gdwarf_:
1451       set_debug_level (DWARF_DEBUG, code == OPT_gdwarf_, arg);
1452       break;
1453
1454     case OPT_gdwarf_2:
1455       set_debug_level (DWARF2_DEBUG, false, arg);
1456       break;
1457
1458     case OPT_ggdb:
1459       set_debug_level (NO_DEBUG, 2, arg);
1460       break;
1461
1462     case OPT_gstabs:
1463     case OPT_gstabs_:
1464       set_debug_level (DBX_DEBUG, code == OPT_gstabs_, arg);
1465       break;
1466
1467     case OPT_gvms:
1468       set_debug_level (VMS_DEBUG, false, arg);
1469       break;
1470
1471     case OPT_gxcoff:
1472     case OPT_gxcoff_:
1473       set_debug_level (XCOFF_DEBUG, code == OPT_gxcoff_, arg);
1474       break;
1475
1476     case OPT_m:
1477       set_target_switch (arg);
1478       break;
1479
1480     case OPT_o:
1481       asm_file_name = arg;
1482       break;
1483
1484     case OPT_p:
1485       profile_flag = 1;
1486       break;
1487
1488     case OPT_pedantic:
1489       pedantic = 1;
1490       break;
1491
1492     case OPT_pedantic_errors:
1493       flag_pedantic_errors = pedantic = 1;
1494       break;
1495
1496     case OPT_quiet:
1497       quiet_flag = 1;
1498       break;
1499
1500     case OPT_version:
1501       version_flag = 1;
1502       break;
1503
1504     case OPT_w:
1505       inhibit_warnings = true;
1506       break;
1507     }
1508
1509   return 1;
1510 }
1511
1512 /* Handle --param NAME=VALUE.  */
1513 static void
1514 handle_param (const char *carg)
1515 {
1516   char *equal, *arg;
1517   int value;
1518
1519   arg = xstrdup (carg);
1520   equal = strchr (arg, '=');
1521   if (!equal)
1522     error ("%s: --param arguments should be of the form NAME=VALUE", arg);
1523   else
1524     {
1525       value = integral_argument (equal + 1);
1526       if (value == -1)
1527         error ("invalid --param value `%s'", equal + 1);
1528       else
1529         {
1530           *equal = '\0';
1531           set_param_value (arg, value);
1532         }
1533     }
1534
1535   free (arg);
1536 }
1537
1538 /* Handle -W and -Wextra.  */
1539 static void
1540 set_Wextra (int setting)
1541 {
1542   extra_warnings = setting;
1543   warn_unused_value = setting;
1544   warn_unused_parameter = (setting && maybe_warn_unused_parameter);
1545
1546   /* We save the value of warn_uninitialized, since if they put
1547      -Wuninitialized on the command line, we need to generate a
1548      warning about not using it without also specifying -O.  */
1549   if (setting == 0)
1550     warn_uninitialized = 0;
1551   else if (warn_uninitialized != 1)
1552     warn_uninitialized = 2;
1553 }
1554
1555 /* Initialize unused warning flags.  */
1556 void
1557 set_Wunused (int setting)
1558 {
1559   warn_unused_function = setting;
1560   warn_unused_label = setting;
1561   /* Unused function parameter warnings are reported when either
1562      ``-Wextra -Wunused'' or ``-Wunused-parameter'' is specified.
1563      Thus, if -Wextra has already been seen, set warn_unused_parameter;
1564      otherwise set maybe_warn_extra_parameter, which will be picked up
1565      by set_Wextra.  */
1566   maybe_warn_unused_parameter = setting;
1567   warn_unused_parameter = (setting && extra_warnings);
1568   warn_unused_variable = setting;
1569   warn_unused_value = setting;
1570 }
1571
1572 /* The following routines are useful in setting all the flags that
1573    -ffast-math and -fno-fast-math imply.  */
1574 void
1575 set_fast_math_flags (int set)
1576 {
1577   flag_trapping_math = !set;
1578   flag_unsafe_math_optimizations = set;
1579   flag_finite_math_only = set;
1580   flag_errno_math = !set;
1581   if (set)
1582     {
1583       flag_signaling_nans = 0;
1584       flag_rounding_math = 0;
1585     }
1586 }
1587
1588 /* Return true iff flags are set as if -ffast-math.  */
1589 bool
1590 fast_math_flags_set_p (void)
1591 {
1592   return (!flag_trapping_math
1593           && flag_unsafe_math_optimizations
1594           && flag_finite_math_only
1595           && !flag_errno_math);
1596 }
1597
1598 /* Handle a debug output -g switch.  EXTENDED is true or false to support
1599    extended output (2 is special and means "-ggdb" was given).  */
1600 static void
1601 set_debug_level (enum debug_info_type type, int extended, const char *arg)
1602 {
1603   static bool type_explicit;
1604
1605   use_gnu_debug_info_extensions = extended;
1606
1607   if (type == NO_DEBUG)
1608     {
1609       if (write_symbols == NO_DEBUG)
1610         {
1611           write_symbols = PREFERRED_DEBUGGING_TYPE;
1612
1613           if (extended == 2)
1614             {
1615 #ifdef DWARF2_DEBUGGING_INFO
1616               write_symbols = DWARF2_DEBUG;
1617 #elif defined DBX_DEBUGGING_INFO
1618               write_symbols = DBX_DEBUG;
1619 #endif
1620             }
1621
1622           if (write_symbols == NO_DEBUG)
1623             warning ("target system does not support debug output");
1624         }
1625     }
1626   else
1627     {
1628       /* Does it conflict with an already selected type?  */
1629       if (type_explicit && write_symbols != NO_DEBUG && type != write_symbols)
1630         error ("debug format \"%s\" conflicts with prior selection",
1631                debug_type_names[type]);
1632       write_symbols = type;
1633       type_explicit = true;
1634     }
1635
1636   /* A debug flag without a level defaults to level 2.  */
1637   if (*arg == '\0')
1638     {
1639       if (!debug_info_level)
1640         debug_info_level = 2;
1641     }
1642   else
1643     {
1644       debug_info_level = integral_argument (arg);
1645       if (debug_info_level == (unsigned int) -1)
1646         error ("unrecognised debug output level \"%s\"", arg);
1647       else if (debug_info_level > 3)
1648         error ("debug output level %s is too high", arg);
1649     }
1650 }
1651
1652 /* Output --help text.  */
1653 static void
1654 print_help (void)
1655 {
1656   size_t i;
1657   const char *p;
1658
1659   GET_ENVIRONMENT (p, "COLUMNS");
1660   if (p)
1661     {
1662       int value = atoi (p);
1663       if (value > 0)
1664         columns = value;
1665     }
1666
1667   puts (_("The following options are language-independent:\n"));
1668
1669   print_filtered_help (CL_COMMON);
1670   print_param_help ();
1671
1672   for (i = 0; lang_names[i]; i++)
1673     {
1674       printf (_("The %s front end recognizes the following options:\n\n"),
1675               lang_names[i]);
1676       print_filtered_help (1U << i);
1677     }
1678
1679   display_target_options ();
1680 }
1681
1682 /* Print the help for --param.  */
1683 static void
1684 print_param_help (void)
1685 {
1686   size_t i;
1687
1688   puts (_("The --param option recognizes the following as parameters:\n"));
1689
1690   for (i = 0; i < LAST_PARAM; i++)
1691     {
1692       const char *help = compiler_params[i].help;
1693       const char *param = compiler_params[i].option;
1694
1695       if (help == NULL || *help == '\0')
1696         help = undocumented_msg;
1697
1698       /* Get the translation.  */
1699       help = _(help);
1700
1701       wrap_help (help, param, strlen (param));
1702     }
1703
1704   putchar ('\n');
1705 }
1706
1707 /* Print help for a specific front-end, etc.  */
1708 static void
1709 print_filtered_help (unsigned int flag)
1710 {
1711   unsigned int i, len, filter, indent = 0;
1712   bool duplicates = false;
1713   const char *help, *opt, *tab;
1714   static char *printed;
1715
1716   if (flag == CL_COMMON)
1717     {
1718       filter = flag;
1719       if (!printed)
1720         printed = xmalloc (cl_options_count);
1721       memset (printed, 0, cl_options_count);
1722     }
1723   else
1724     {
1725       /* Don't print COMMON options twice.  */
1726       filter = flag | CL_COMMON;
1727
1728       for (i = 0; i < cl_options_count; i++)
1729         {
1730           if ((cl_options[i].flags & filter) != flag)
1731             continue;
1732
1733           /* Skip help for internal switches.  */
1734           if (cl_options[i].flags & CL_UNDOCUMENTED)
1735             continue;
1736
1737           /* Skip switches that have already been printed, mark them to be
1738              listed later.  */
1739           if (printed[i])
1740             {
1741               duplicates = true;
1742               indent = print_switch (cl_options[i].opt_text, indent);
1743             }
1744         }
1745
1746       if (duplicates)
1747         {
1748           putchar ('\n');
1749           putchar ('\n');
1750         }
1751     }
1752
1753   for (i = 0; i < cl_options_count; i++)
1754     {
1755       if ((cl_options[i].flags & filter) != flag)
1756         continue;
1757
1758       /* Skip help for internal switches.  */
1759       if (cl_options[i].flags & CL_UNDOCUMENTED)
1760         continue;
1761
1762       /* Skip switches that have already been printed.  */
1763       if (printed[i])
1764         continue;
1765
1766       printed[i] = true;
1767
1768       help = cl_options[i].help;
1769       if (!help)
1770         help = undocumented_msg;
1771
1772       /* Get the translation.  */
1773       help = _(help);
1774
1775       tab = strchr (help, '\t');
1776       if (tab)
1777         {
1778           len = tab - help;
1779           opt = help;
1780           help = tab + 1;
1781         }
1782       else
1783         {
1784           opt = cl_options[i].opt_text;
1785           len = strlen (opt);
1786         }
1787
1788       wrap_help (help, opt, len);
1789     }
1790
1791   putchar ('\n');
1792 }
1793
1794 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1795    word-wrapped HELP in a second column.  */
1796 static unsigned int
1797 print_switch (const char *text, unsigned int indent)
1798 {
1799   unsigned int len = strlen (text) + 1; /* trailing comma */
1800
1801   if (indent)
1802     {
1803       putchar (',');
1804       if (indent + len > columns)
1805         {
1806           putchar ('\n');
1807           putchar (' ');
1808           indent = 1;
1809         }
1810     }
1811   else
1812     putchar (' ');
1813
1814   putchar (' ');
1815   fputs (text, stdout);
1816
1817   return indent + len + 1;
1818 }
1819
1820 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1821    word-wrapped HELP in a second column.  */
1822 static void
1823 wrap_help (const char *help, const char *item, unsigned int item_width)
1824 {
1825   unsigned int col_width = 27;
1826   unsigned int remaining, room, len;
1827
1828   remaining = strlen (help);
1829
1830   do
1831     {
1832       room = columns - 3 - MAX (col_width, item_width);
1833       if (room > columns)
1834         room = 0;
1835       len = remaining;
1836
1837       if (room < len)
1838         {
1839           unsigned int i;
1840
1841           for (i = 0; help[i]; i++)
1842             {
1843               if (i >= room && len != remaining)
1844                 break;
1845               if (help[i] == ' ')
1846                 len = i;
1847               else if ((help[i] == '-' || help[i] == '/')
1848                        && help[i + 1] != ' '
1849                        && ISALPHA (help[i - 1]))
1850                 len = i + 1;
1851             }
1852         }
1853
1854       printf( "  %-*.*s %.*s\n", col_width, item_width, item, len, help);
1855       item_width = 0;
1856       while (help[len] == ' ')
1857         len++;
1858       help += len;
1859       remaining -= len;
1860     }
1861   while (remaining);
1862 }