gcc/opts.c

   1 /* Command line option handling.
   2    Copyright (C) 2002, 2003, 2004, 2005 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 #include "target.h"
  41
  42 /* Value of the -G xx switch, and whether it was passed or not.  */
  43 unsigned HOST_WIDE_INT g_switch_value;
  44 bool g_switch_set;
  45
  46 /* True if we should exit after parsing options.  */
  47 bool exit_after_options;
  48
  49 /* Print various extra warnings.  -W/-Wextra.  */
  50 bool extra_warnings;
  51
  52 /* True to warn about any objects definitions whose size is larger
  53    than N bytes.  Also want about function definitions whose returned
  54    values are larger than N bytes, where N is `larger_than_size'.  */
  55 bool warn_larger_than;
  56 HOST_WIDE_INT larger_than_size;
  57
  58 /* Nonzero means warn about constructs which might not be
  59    strict-aliasing safe.  */
  60 int warn_strict_aliasing;
  61
  62 /* Hack for cooperation between set_Wunused and set_Wextra.  */
  63 static bool maybe_warn_unused_parameter;
  64
  65 /* Type(s) of debugging information we are producing (if any).  See
  66    flags.h for the definitions of the different possible types of
  67    debugging information.  */
  68 enum debug_info_type write_symbols = NO_DEBUG;
  69
  70 /* Level of debugging information we are producing.  See flags.h for
  71    the definitions of the different possible levels.  */
  72 enum debug_info_level debug_info_level = DINFO_LEVEL_NONE;
  73
  74 /* Nonzero means use GNU-only extensions in the generated symbolic
  75    debugging information.  Currently, this only has an effect when
  76    write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.  */
  77 bool use_gnu_debug_info_extensions;
  78
  79 /* The default visibility for all symbols (unless overridden) */
  80 enum symbol_visibility default_visibility = VISIBILITY_DEFAULT;
  81
  82 /* Global visibility options.  */
  83 struct visibility_flags visibility_options;
  84
  85 /* Columns of --help display.  */
  86 static unsigned int columns = 80;
  87
  88 /* What to print when a switch has no documentation.  */
  89 static const char undocumented_msg[] = N_("This switch lacks documentation");
  90
  91 /* Used for bookkeeping on whether user set these flags so
  92    -fprofile-use/-fprofile-generate does not use them.  */
  93 static bool profile_arc_flag_set, flag_profile_values_set;
  94 static bool flag_unroll_loops_set, flag_tracer_set;
  95 static bool flag_value_profile_transformations_set;
  96 bool flag_speculative_prefetching_set;
  97 static bool flag_peel_loops_set, flag_branch_probabilities_set;
  98
  99 /* Input file names.  */
 100 const char **in_fnames;
 101 unsigned num_in_fnames;
 102
 103 static size_t find_opt (const char *, int);
 104 static int common_handle_option (size_t scode, const char *arg, int value);
 105 static void handle_param (const char *);
 106 static void set_Wextra (int);
 107 static unsigned int handle_option (const char **argv, unsigned int lang_mask);
 108 static char *write_langs (unsigned int lang_mask);
 109 static void complain_wrong_lang (const char *, const struct cl_option *,
 110                                  unsigned int lang_mask);
 111 static void handle_options (unsigned int, const char **, unsigned int);
 112 static void wrap_help (const char *help, const char *item, unsigned int);
 113 static void print_help (void);
 114 static void print_param_help (void);
 115 static unsigned int print_switch (const char *text, unsigned int indent);
 116 static void set_debug_level (enum debug_info_type type, int extended,
 117                              const char *arg);
 118
 119 /* Perform a binary search to find which option the command-line INPUT
 120    matches.  Returns its index in the option array, and N_OPTS
 121    (cl_options_count) on failure.
 122
 123    This routine is quite subtle.  A normal binary search is not good
 124    enough because some options can be suffixed with an argument, and
 125    multiple sub-matches can occur, e.g. input of "-pedantic" matching
 126    the initial substring of "-pedantic-errors".
 127
 128    A more complicated example is -gstabs.  It should match "-g" with
 129    an argument of "stabs".  Suppose, however, that the number and list
 130    of switches are such that the binary search tests "-gen-decls"
 131    before having tested "-g".  This doesn't match, and as "-gen-decls"
 132    is less than "-gstabs", it will become the lower bound of the
 133    binary search range, and "-g" will never be seen.  To resolve this
 134    issue, opts.sh makes "-gen-decls" point, via the back_chain member,
 135    to "-g" so that failed searches that end between "-gen-decls" and
 136    the lexicographically subsequent switch know to go back and see if
 137    "-g" causes a match (which it does in this example).
 138
 139    This search is done in such a way that the longest match for the
 140    front end in question wins.  If there is no match for the current
 141    front end, the longest match for a different front end is returned
 142    (or N_OPTS if none) and the caller emits an error message.  */
 143 static size_t
 144 find_opt (const char *input, int lang_mask)
 145 {
 146   size_t mn, mx, md, opt_len;
 147   size_t match_wrong_lang;
 148   int comp;
 149
 150   mn = 0;
 151   mx = cl_options_count;
 152
 153   /* Find mn such this lexicographical inequality holds:
 154      cl_options[mn] <= input < cl_options[mn + 1].  */
 155   while (mx - mn > 1)
 156     {
 157       md = (mn + mx) / 2;
 158       opt_len = cl_options[md].opt_len;
 159       comp = strncmp (input, cl_options[md].opt_text + 1, opt_len);
 160
 161       if (comp < 0)
 162         mx = md;
 163       else
 164         mn = md;
 165     }
 166
 167   /* This is the switch that is the best match but for a different
 168      front end, or cl_options_count if there is no match at all.  */
 169   match_wrong_lang = cl_options_count;
 170
 171   /* Backtrace the chain of possible matches, returning the longest
 172      one, if any, that fits best.  With current GCC switches, this
 173      loop executes at most twice.  */
 174   do
 175     {
 176       const struct cl_option *opt = &cl_options[mn];
 177
 178       /* Is the input either an exact match or a prefix that takes a
 179          joined argument?  */
 180       if (!strncmp (input, opt->opt_text + 1, opt->opt_len)
 181           && (input[opt->opt_len] == '\0' || (opt->flags & CL_JOINED)))
 182         {
 183           /* If language is OK, return it.  */
 184           if (opt->flags & lang_mask)
 185             return mn;
 186
 187           /* If we haven't remembered a prior match, remember this
 188              one.  Any prior match is necessarily better.  */
 189           if (match_wrong_lang == cl_options_count)
 190             match_wrong_lang = mn;
 191         }
 192
 193       /* Try the next possibility.  This is cl_options_count if there
 194          are no more.  */
 195       mn = opt->back_chain;
 196     }
 197   while (mn != cl_options_count);
 198
 199   /* Return the best wrong match, or cl_options_count if none.  */
 200   return match_wrong_lang;
 201 }
 202
 203 /* If ARG is a non-negative integer made up solely of digits, return its
 204    value, otherwise return -1.  */
 205 static int
 206 integral_argument (const char *arg)
 207 {
 208   const char *p = arg;
 209
 210   while (*p && ISDIGIT (*p))
 211     p++;
 212
 213   if (*p == '\0')
 214     return atoi (arg);
 215
 216   return -1;
 217 }
 218
 219 /* Return a malloced slash-separated list of languages in MASK.  */
 220 static char *
 221 write_langs (unsigned int mask)
 222 {
 223   unsigned int n = 0, len = 0;
 224   const char *lang_name;
 225   char *result;
 226
 227   for (n = 0; (lang_name = lang_names[n]) != 0; n++)
 228     if (mask & (1U << n))
 229       len += strlen (lang_name) + 1;
 230
 231   result = xmalloc (len);
 232   len = 0;
 233   for (n = 0; (lang_name = lang_names[n]) != 0; n++)
 234     if (mask & (1U << n))
 235       {
 236         if (len)
 237           result[len++] = '/';
 238         strcpy (result + len, lang_name);
 239         len += strlen (lang_name);
 240       }
 241
 242   result[len] = 0;
 243
 244   return result;
 245 }
 246
 247 /* Complain that switch OPT_INDEX does not apply to this front end.  */
 248 static void
 249 complain_wrong_lang (const char *text, const struct cl_option *option,
 250                      unsigned int lang_mask)
 251 {
 252   char *ok_langs, *bad_lang;
 253
 254   ok_langs = write_langs (option->flags);
 255   bad_lang = write_langs (lang_mask);
 256
 257   /* Eventually this should become a hard error IMO.  */
 258   warning ("command line option \"%s\" is valid for %s but not for %s",
 259            text, ok_langs, bad_lang);
 260
 261   free (ok_langs);
 262   free (bad_lang);
 263 }
 264
 265 /* Handle the switch beginning at ARGV for the language indicated by
 266    LANG_MASK.  Returns the number of switches consumed.  */
 267 static unsigned int
 268 handle_option (const char **argv, unsigned int lang_mask)
 269 {
 270   size_t opt_index;
 271   const char *opt, *arg = 0;
 272   char *dup = 0;
 273   int value = 1;
 274   unsigned int result = 0;
 275   const struct cl_option *option;
 276
 277   opt = argv[0];
 278
 279   opt_index = find_opt (opt + 1, lang_mask | CL_COMMON | CL_TARGET);
 280   if (opt_index == cl_options_count
 281       && (opt[1] == 'W' || opt[1] == 'f' || opt[1] == 'm')
 282       && opt[2] == 'n' && opt[3] == 'o' && opt[4] == '-')
 283     {
 284       /* Drop the "no-" from negative switches.  */
 285       size_t len = strlen (opt) - 3;
 286
 287       dup = xmalloc (len + 1);
 288       dup[0] = '-';
 289       dup[1] = opt[1];
 290       memcpy (dup + 2, opt + 5, len - 2 + 1);
 291       opt = dup;
 292       value = 0;
 293       opt_index = find_opt (opt + 1, lang_mask | CL_COMMON | CL_TARGET);
 294     }
 295
 296   if (opt_index == cl_options_count)
 297     {
 298 #if defined (TARGET_OPTIONS) || defined (TARGET_SWITCHES)
 299       if (opt[1] == 'm')
 300         {
 301           set_target_switch (argv[0] + 2);
 302           result = 1;
 303         }
 304 #endif
 305       goto done;
 306     }
 307
 308   option = &cl_options[opt_index];
 309
 310   /* Reject negative form of switches that don't take negatives as
 311      unrecognized.  */
 312   if (!value && (option->flags & CL_REJECT_NEGATIVE))
 313     goto done;
 314
 315   /* We've recognized this switch.  */
 316   result = 1;
 317
 318   /* Sort out any argument the switch takes.  */
 319   if (option->flags & CL_JOINED)
 320     {
 321       /* Have arg point to the original switch.  This is because
 322          some code, such as disable_builtin_function, expects its
 323          argument to be persistent until the program exits.  */
 324       arg = argv[0] + cl_options[opt_index].opt_len + 1;
 325       if (!value)
 326         arg += strlen ("no-");
 327
 328       if (*arg == '\0' && !(option->flags & CL_MISSING_OK))
 329         {
 330           if (option->flags & CL_SEPARATE)
 331             {
 332               arg = argv[1];
 333               result = 2;
 334             }
 335           else
 336             /* Missing argument.  */
 337             arg = NULL;
 338         }
 339     }
 340   else if (option->flags & CL_SEPARATE)
 341     {
 342       arg = argv[1];
 343       result = 2;
 344     }
 345
 346   /* Now we've swallowed any potential argument, complain if this
 347      is a switch for a different front end.  */
 348   if (!(option->flags & (lang_mask | CL_COMMON | CL_TARGET)))
 349     {
 350       complain_wrong_lang (argv[0], option, lang_mask);
 351       goto done;
 352     }
 353
 354   if (arg == NULL && (option->flags & (CL_JOINED | CL_SEPARATE)))
 355     {
 356       if (!lang_hooks.missing_argument (opt, opt_index))
 357         error ("missing argument to \"%s\"", opt);
 358       goto done;
 359     }
 360
 361   /* If the switch takes an integer, convert it.  */
 362   if (arg && (option->flags & CL_UINTEGER))
 363     {
 364       value = integral_argument (arg);
 365       if (value == -1)
 366         {
 367           error ("argument to \"%s\" should be a non-negative integer",
 368                  option->opt_text);
 369           goto done;
 370         }
 371     }
 372
 373   if (option->flag_var)
 374     switch (option->var_cond)
 375       {
 376       case CLVC_BOOLEAN:
 377         *option->flag_var = value;
 378         break;
 379
 380       case CLVC_EQUAL:
 381         *option->flag_var = value ? option->var_value : !option->var_value;
 382         break;
 383
 384       case CLVC_BIT_CLEAR:
 385       case CLVC_BIT_SET:
 386         if ((value != 0) == (option->var_cond == CLVC_BIT_SET))
 387           *option->flag_var |= option->var_value;
 388         else
 389           *option->flag_var &= ~option->var_value;
 390         if (option->flag_var == &target_flags)
 391           target_flags_explicit |= option->var_value;
 392         break;
 393       }
 394
 395   if (option->flags & lang_mask)
 396     if (lang_hooks.handle_option (opt_index, arg, value) == 0)
 397       result = 0;
 398
 399   if (result && (option->flags & CL_COMMON))
 400     if (common_handle_option (opt_index, arg, value) == 0)
 401       result = 0;
 402
 403   if (result && (option->flags & CL_TARGET))
 404     if (!targetm.handle_option (opt_index, arg, value))
 405       result = 0;
 406
 407  done:
 408   if (dup)
 409     free (dup);
 410   return result;
 411 }
 412
 413 /* Handle FILENAME from the command line.  */
 414 static void
 415 add_input_filename (const char *filename)
 416 {
 417   num_in_fnames++;
 418   in_fnames = xrealloc (in_fnames, num_in_fnames * sizeof (in_fnames[0]));
 419   in_fnames[num_in_fnames - 1] = filename;
 420 }
 421
 422 /* Decode and handle the vector of command line options.  LANG_MASK
 423    contains has a single bit set representing the current
 424    language.  */
 425 static void
 426 handle_options (unsigned int argc, const char **argv, unsigned int lang_mask)
 427 {
 428   unsigned int n, i;
 429
 430   for (i = 1; i < argc; i += n)
 431     {
 432       const char *opt = argv[i];
 433
 434       /* Interpret "-" or a non-switch as a file name.  */
 435       if (opt[0] != '-' || opt[1] == '\0')
 436         {
 437           if (main_input_filename == NULL)
 438             main_input_filename = opt;
 439           add_input_filename (opt);
 440           n = 1;
 441           continue;
 442         }
 443
 444       n = handle_option (argv + i, lang_mask);
 445
 446       if (!n)
 447         {
 448           n = 1;
 449           error ("unrecognized command line option \"%s\"", opt);
 450         }
 451     }
 452 }
 453
 454 /* Parse command line options and set default flag values.  Do minimal
 455    options processing.  */
 456 void
 457 decode_options (unsigned int argc, const char **argv)
 458 {
 459   unsigned int i, lang_mask;
 460
 461   /* Perform language-specific options initialization.  */
 462   lang_mask = lang_hooks.init_options (argc, argv);
 463
 464   lang_hooks.initialize_diagnostics (global_dc);
 465
 466   /* Scan to see what optimization level has been specified.  That will
 467      determine the default value of many flags.  */
 468   for (i = 1; i < argc; i++)
 469     {
 470       if (!strcmp (argv[i], "-O"))
 471         {
 472           optimize = 1;
 473           optimize_size = 0;
 474         }
 475       else if (argv[i][0] == '-' && argv[i][1] == 'O')
 476         {
 477           /* Handle -Os, -O2, -O3, -O69, ...  */
 478           const char *p = &argv[i][2];
 479
 480           if ((p[0] == 's') && (p[1] == 0))
 481             {
 482               optimize_size = 1;
 483
 484               /* Optimizing for size forces optimize to be 2.  */
 485               optimize = 2;
 486             }
 487           else
 488             {
 489               const int optimize_val = read_integral_parameter (p, p - 2, -1);
 490               if (optimize_val != -1)
 491                 {
 492                   optimize = optimize_val;
 493                   optimize_size = 0;
 494                 }
 495             }
 496         }
 497     }
 498
 499   if (!optimize)
 500     {
 501       flag_merge_constants = 0;
 502     }
 503
 504   if (optimize >= 1)
 505     {
 506       flag_defer_pop = 1;
 507 #ifdef DELAY_SLOTS
 508       flag_delayed_branch = 1;
 509 #endif
 510 #ifdef CAN_DEBUG_WITHOUT_FP
 511       flag_omit_frame_pointer = 1;
 512 #endif
 513       flag_guess_branch_prob = 1;
 514       flag_cprop_registers = 1;
 515       flag_loop_optimize = 1;
 516       flag_if_conversion = 1;
 517       flag_if_conversion2 = 1;
 518       flag_tree_ccp = 1;
 519       flag_tree_dce = 1;
 520       flag_tree_dom = 1;
 521       flag_tree_dse = 1;
 522       flag_tree_ter = 1;
 523       flag_tree_live_range_split = 1;
 524       flag_tree_sra = 1;
 525       flag_tree_copyrename = 1;
 526       flag_tree_fre = 1;
 527       flag_tree_copy_prop = 1;
 528       flag_tree_sink = 1;
 529       flag_tree_salias = 1;
 530
 531       if (!optimize_size)
 532         {
 533           /* Loop header copying usually increases size of the code.  This used
 534              not to be true, since quite often it is possible to verify that
 535              the condition is satisfied in the first iteration and therefore
 536              to eliminate it.  Jump threading handles these cases now.  */
 537           flag_tree_ch = 1;
 538         }
 539     }
 540
 541   if (optimize >= 2)
 542     {
 543       flag_thread_jumps = 1;
 544       flag_crossjumping = 1;
 545       flag_optimize_sibling_calls = 1;
 546       flag_cse_follow_jumps = 1;
 547       flag_cse_skip_blocks = 1;
 548       flag_gcse = 1;
 549       flag_expensive_optimizations = 1;
 550       flag_strength_reduce = 1;
 551       flag_rerun_cse_after_loop = 1;
 552       flag_rerun_loop_opt = 1;
 553       flag_caller_saves = 1;
 554       flag_force_mem = 1;
 555       flag_peephole2 = 1;
 556 #ifdef INSN_SCHEDULING
 557       flag_schedule_insns = 1;
 558       flag_schedule_insns_after_reload = 1;
 559 #endif
 560       flag_regmove = 1;
 561       flag_strict_aliasing = 1;
 562       flag_delete_null_pointer_checks = 1;
 563       flag_reorder_blocks = 1;
 564       flag_reorder_functions = 1;
 565       flag_unit_at_a_time = 1;
 566       flag_tree_store_ccp = 1;
 567       flag_tree_store_copy_prop = 1;
 568       flag_tree_vrp = 1;
 569
 570       if (!optimize_size)
 571         {
 572           /* PRE tends to generate bigger code.  */
 573           flag_tree_pre = 1;
 574         }
 575     }
 576
 577   if (optimize >= 3)
 578     {
 579       flag_inline_functions = 1;
 580       flag_unswitch_loops = 1;
 581       flag_gcse_after_reload = 1;
 582     }
 583
 584   if (optimize < 2 || optimize_size)
 585     {
 586       align_loops = 1;
 587       align_jumps = 1;
 588       align_labels = 1;
 589       align_functions = 1;
 590
 591       /* Don't reorder blocks when optimizing for size because extra
 592          jump insns may be created; also barrier may create extra padding.
 593
 594          More correctly we should have a block reordering mode that tried
 595          to minimize the combined size of all the jumps.  This would more
 596          or less automatically remove extra jumps, but would also try to
 597          use more short jumps instead of long jumps.  */
 598       flag_reorder_blocks = 0;
 599       flag_reorder_blocks_and_partition = 0;
 600     }
 601
 602   if (optimize_size)
 603     {
 604       /* Inlining of very small functions usually reduces total size.  */
 605       set_param_value ("max-inline-insns-single", 5);
 606       set_param_value ("max-inline-insns-auto", 5);
 607       flag_inline_functions = 1;
 608
 609       /* We want to crossjump as much as possible.  */
 610       set_param_value ("min-crossjump-insns", 1);
 611     }
 612
 613   /* Initialize whether `char' is signed.  */
 614   flag_signed_char = DEFAULT_SIGNED_CHAR;
 615   /* Set this to a special "uninitialized" value.  The actual default is set
 616      after target options have been processed.  */
 617   flag_short_enums = 2;
 618
 619   /* Initialize target_flags before OPTIMIZATION_OPTIONS so the latter can
 620      modify it.  */
 621   target_flags = targetm.default_target_flags;
 622   set_target_switch ("");
 623
 624   /* Unwind tables are always present when a target has ABI-specified unwind
 625      tables, so the default should be ON.  */
 626 #ifdef TARGET_UNWIND_INFO
 627   flag_unwind_tables = TARGET_UNWIND_INFO;
 628 #endif
 629
 630 #ifdef OPTIMIZATION_OPTIONS
 631   /* Allow default optimizations to be specified on a per-machine basis.  */
 632   OPTIMIZATION_OPTIONS (optimize, optimize_size);
 633 #endif
 634
 635   handle_options (argc, argv, lang_mask);
 636
 637   if (flag_pie)
 638     flag_pic = flag_pie;
 639   if (flag_pic && !flag_pie)
 640     flag_shlib = 1;
 641
 642   if (flag_no_inline == 2)
 643     flag_no_inline = 0;
 644   else
 645     flag_really_no_inline = flag_no_inline;
 646
 647   /* Set flag_no_inline before the post_options () hook.  The C front
 648      ends use it to determine tree inlining defaults.  FIXME: such
 649      code should be lang-independent when all front ends use tree
 650      inlining, in which case it, and this condition, should be moved
 651      to the top of process_options() instead.  */
 652   if (optimize == 0)
 653     {
 654       /* Inlining does not work if not optimizing,
 655          so force it not to be done.  */
 656       flag_no_inline = 1;
 657       warn_inline = 0;
 658
 659       /* The c_decode_option function and decode_option hook set
 660          this to `2' if -Wall is used, so we can avoid giving out
 661          lots of errors for people who don't realize what -Wall does.  */
 662       if (warn_uninitialized == 1)
 663         warning ("-Wuninitialized is not supported without -O");
 664     }
 665
 666   if (flag_really_no_inline == 2)
 667     flag_really_no_inline = flag_no_inline;
 668
 669   /* The optimization to partition hot and cold basic blocks into separate
 670      sections of the .o and executable files does not work (currently)
 671      with exception handling.  If flag_exceptions is turned on we need to
 672      turn off the partitioning optimization.  */
 673
 674   if (flag_exceptions && flag_reorder_blocks_and_partition)
 675     {
 676       inform
 677             ("-freorder-blocks-and-partition does not work with exceptions");
 678       flag_reorder_blocks_and_partition = 0;
 679       flag_reorder_blocks = 1;
 680     }
 681 }
 682
 683 /* Handle target- and language-independent options.  Return zero to
 684    generate an "unknown option" message.  Only options that need
 685    extra handling need to be listed here; if you simply want
 686    VALUE assigned to a variable, it happens automatically.  */
 687
 688 static int
 689 common_handle_option (size_t scode, const char *arg, int value)
 690 {
 691   enum opt_code code = (enum opt_code) scode;
 692
 693   switch (code)
 694     {
 695     case OPT__help:
 696       print_help ();
 697       exit_after_options = true;
 698       break;
 699
 700     case OPT__param:
 701       handle_param (arg);
 702       break;
 703
 704     case OPT__target_help:
 705       display_target_options ();
 706       exit_after_options = true;
 707       break;
 708
 709     case OPT__version:
 710       print_version (stderr, "");
 711       exit_after_options = true;
 712       break;
 713
 714     case OPT_G:
 715       g_switch_value = value;
 716       g_switch_set = true;
 717       break;
 718
 719     case OPT_O:
 720     case OPT_Os:
 721       /* Currently handled in a prescan.  */
 722       break;
 723
 724     case OPT_W:
 725       /* For backward compatibility, -W is the same as -Wextra.  */
 726       set_Wextra (value);
 727       break;
 728
 729     case OPT_Wextra:
 730       set_Wextra (value);
 731       break;
 732
 733     case OPT_Wlarger_than_:
 734       larger_than_size = value;
 735       warn_larger_than = value != -1;
 736       break;
 737
 738     case OPT_Wstrict_aliasing:
 739     case OPT_Wstrict_aliasing_:
 740       warn_strict_aliasing = value;
 741       break;
 742
 743     case OPT_Wunused:
 744       set_Wunused (value);
 745       break;
 746
 747     case OPT_aux_info:
 748     case OPT_aux_info_:
 749       aux_info_file_name = arg;
 750       flag_gen_aux_info = 1;
 751       break;
 752
 753     case OPT_auxbase:
 754       aux_base_name = arg;
 755       break;
 756
 757     case OPT_auxbase_strip:
 758       {
 759         char *tmp = xstrdup (arg);
 760         strip_off_ending (tmp, strlen (tmp));
 761         if (tmp[0])
 762           aux_base_name = tmp;
 763       }
 764       break;
 765
 766     case OPT_d:
 767       decode_d_option (arg);
 768       break;
 769
 770     case OPT_dumpbase:
 771       dump_base_name = arg;
 772       break;
 773
 774     case OPT_falign_functions_:
 775       align_functions = value;
 776       break;
 777
 778     case OPT_falign_jumps_:
 779       align_jumps = value;
 780       break;
 781
 782     case OPT_falign_labels_:
 783       align_labels = value;
 784       break;
 785
 786     case OPT_falign_loops_:
 787       align_loops = value;
 788       break;
 789
 790     case OPT_fbranch_probabilities:
 791       flag_branch_probabilities_set = true;
 792       break;
 793
 794     case OPT_fcall_used_:
 795       fix_register (arg, 0, 1);
 796       break;
 797
 798     case OPT_fcall_saved_:
 799       fix_register (arg, 0, 0);
 800       break;
 801
 802     case OPT_fdiagnostics_show_location_:
 803       if (!strcmp (arg, "once"))
 804         diagnostic_prefixing_rule (global_dc) = DIAGNOSTICS_SHOW_PREFIX_ONCE;
 805       else if (!strcmp (arg, "every-line"))
 806         diagnostic_prefixing_rule (global_dc)
 807           = DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE;
 808       else
 809         return 0;
 810       break;
 811
 812     case OPT_fdump_:
 813       if (!dump_switch_p (arg))
 814         return 0;
 815       break;
 816
 817     case OPT_ffast_math:
 818       set_fast_math_flags (value);
 819       break;
 820
 821     case OPT_ffixed_:
 822       fix_register (arg, 1, 1);
 823       break;
 824
 825     case OPT_finline_limit_:
 826     case OPT_finline_limit_eq:
 827       set_param_value ("max-inline-insns-single", value / 2);
 828       set_param_value ("max-inline-insns-auto", value / 2);
 829       break;
 830
 831     case OPT_fmessage_length_:
 832       pp_set_line_maximum_length (global_dc->printer, value);
 833       break;
 834
 835     case OPT_fpack_struct_:
 836       if (value <= 0 || (value & (value - 1)) || value > 16)
 837         error("structure alignment must be a small power of two, not %d", value);
 838       else
 839         {
 840           initial_max_fld_align = value;
 841           maximum_field_alignment = value * BITS_PER_UNIT;
 842         }
 843       break;
 844
 845     case OPT_fpeel_loops:
 846       flag_peel_loops_set = true;
 847       break;
 848
 849     case OPT_fprofile_arcs:
 850       profile_arc_flag_set = true;
 851       break;
 852
 853     case OPT_fprofile_use:
 854       if (!flag_branch_probabilities_set)
 855         flag_branch_probabilities = value;
 856       if (!flag_profile_values_set)
 857         flag_profile_values = value;
 858       if (!flag_unroll_loops_set)
 859         flag_unroll_loops = value;
 860       if (!flag_peel_loops_set)
 861         flag_peel_loops = value;
 862       if (!flag_tracer_set)
 863         flag_tracer = value;
 864       if (!flag_value_profile_transformations_set)
 865         flag_value_profile_transformations = value;
 866 #ifdef HAVE_prefetch
 867       if (0 && !flag_speculative_prefetching_set)
 868         flag_speculative_prefetching = value;
 869 #endif
 870       break;
 871
 872     case OPT_fprofile_generate:
 873       if (!profile_arc_flag_set)
 874         profile_arc_flag = value;
 875       if (!flag_profile_values_set)
 876         flag_profile_values = value;
 877       if (!flag_value_profile_transformations_set)
 878         flag_value_profile_transformations = value;
 879       if (!flag_unroll_loops_set)
 880         flag_unroll_loops = value;
 881 #ifdef HAVE_prefetch
 882       if (0 && !flag_speculative_prefetching_set)
 883         flag_speculative_prefetching = value;
 884 #endif
 885       break;
 886
 887     case OPT_fprofile_values:
 888       flag_profile_values_set = true;
 889       break;
 890
 891     case OPT_fvisibility_:
 892       {
 893         if (!strcmp(arg, "default"))
 894           default_visibility = VISIBILITY_DEFAULT;
 895         else if (!strcmp(arg, "internal"))
 896           default_visibility = VISIBILITY_INTERNAL;
 897         else if (!strcmp(arg, "hidden"))
 898           default_visibility = VISIBILITY_HIDDEN;
 899         else if (!strcmp(arg, "protected"))
 900           default_visibility = VISIBILITY_PROTECTED;
 901         else
 902           error ("unrecognised visibility value \"%s\"", arg);
 903       }
 904       break;
 905
 906     case OPT_fvpt:
 907       flag_value_profile_transformations_set = true;
 908       break;
 909
 910     case OPT_fspeculative_prefetching:
 911       flag_speculative_prefetching_set = true;
 912       break;
 913
 914     case OPT_frandom_seed:
 915       /* The real switch is -fno-random-seed.  */
 916       if (value)
 917         return 0;
 918       flag_random_seed = NULL;
 919       break;
 920
 921     case OPT_frandom_seed_:
 922       flag_random_seed = arg;
 923       break;
 924
 925     case OPT_fsched_verbose_:
 926 #ifdef INSN_SCHEDULING
 927       fix_sched_param ("verbose", arg);
 928       break;
 929 #else
 930       return 0;
 931 #endif
 932
 933     case OPT_fsched_stalled_insns_:
 934       flag_sched_stalled_insns = value;
 935       if (flag_sched_stalled_insns == 0)
 936         flag_sched_stalled_insns = -1;
 937       break;
 938
 939     case OPT_fsched_stalled_insns_dep_:
 940       flag_sched_stalled_insns_dep = value;
 941       break;
 942
 943     case OPT_fstack_limit:
 944       /* The real switch is -fno-stack-limit.  */
 945       if (value)
 946         return 0;
 947       stack_limit_rtx = NULL_RTX;
 948       break;
 949
 950     case OPT_fstack_limit_register_:
 951       {
 952         int reg = decode_reg_name (arg);
 953         if (reg < 0)
 954           error ("unrecognized register name \"%s\"", arg);
 955         else
 956           stack_limit_rtx = gen_rtx_REG (Pmode, reg);
 957       }
 958       break;
 959
 960     case OPT_fstack_limit_symbol_:
 961       stack_limit_rtx = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (arg));
 962       break;
 963
 964     case OPT_ftree_vectorizer_verbose_:
 965       vect_set_verbosity_level (arg);
 966       break;
 967
 968     case OPT_ftls_model_:
 969       if (!strcmp (arg, "global-dynamic"))
 970         flag_tls_default = TLS_MODEL_GLOBAL_DYNAMIC;
 971       else if (!strcmp (arg, "local-dynamic"))
 972         flag_tls_default = TLS_MODEL_LOCAL_DYNAMIC;
 973       else if (!strcmp (arg, "initial-exec"))
 974         flag_tls_default = TLS_MODEL_INITIAL_EXEC;
 975       else if (!strcmp (arg, "local-exec"))
 976         flag_tls_default = TLS_MODEL_LOCAL_EXEC;
 977       else
 978         warning ("unknown tls-model \"%s\"", arg);
 979       break;
 980
 981     case OPT_ftracer:
 982       flag_tracer_set = true;
 983       break;
 984
 985     case OPT_funroll_loops:
 986       flag_unroll_loops_set = true;
 987       break;
 988
 989     case OPT_g:
 990       set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg);
 991       break;
 992
 993     case OPT_gcoff:
 994       set_debug_level (SDB_DEBUG, false, arg);
 995       break;
 996
 997     case OPT_gdwarf_2:
 998       set_debug_level (DWARF2_DEBUG, false, arg);
 999       break;
1000
1001     case OPT_ggdb:
1002       set_debug_level (NO_DEBUG, 2, arg);
1003       break;
1004
1005     case OPT_gstabs:
1006     case OPT_gstabs_:
1007       set_debug_level (DBX_DEBUG, code == OPT_gstabs_, arg);
1008       break;
1009
1010     case OPT_gvms:
1011       set_debug_level (VMS_DEBUG, false, arg);
1012       break;
1013
1014     case OPT_gxcoff:
1015     case OPT_gxcoff_:
1016       set_debug_level (XCOFF_DEBUG, code == OPT_gxcoff_, arg);
1017       break;
1018
1019     case OPT_o:
1020       asm_file_name = arg;
1021       break;
1022
1023     case OPT_pedantic_errors:
1024       flag_pedantic_errors = pedantic = 1;
1025       break;
1026
1027     default:
1028       /* If the flag was handled in a standard way, assume the lack of
1029          processing here is intentional.  */
1030       if (cl_options[scode].flag_var)
1031         break;
1032
1033       abort ();
1034     }
1035
1036   return 1;
1037 }
1038
1039 /* Handle --param NAME=VALUE.  */
1040 static void
1041 handle_param (const char *carg)
1042 {
1043   char *equal, *arg;
1044   int value;
1045
1046   arg = xstrdup (carg);
1047   equal = strchr (arg, '=');
1048   if (!equal)
1049     error ("%s: --param arguments should be of the form NAME=VALUE", arg);
1050   else
1051     {
1052       value = integral_argument (equal + 1);
1053       if (value == -1)
1054         error ("invalid --param value %qs", equal + 1);
1055       else
1056         {
1057           *equal = '\0';
1058           set_param_value (arg, value);
1059         }
1060     }
1061
1062   free (arg);
1063 }
1064
1065 /* Handle -W and -Wextra.  */
1066 static void
1067 set_Wextra (int setting)
1068 {
1069   extra_warnings = setting;
1070   warn_unused_value = setting;
1071   warn_unused_parameter = (setting && maybe_warn_unused_parameter);
1072
1073   /* We save the value of warn_uninitialized, since if they put
1074      -Wuninitialized on the command line, we need to generate a
1075      warning about not using it without also specifying -O.  */
1076   if (setting == 0)
1077     warn_uninitialized = 0;
1078   else if (warn_uninitialized != 1)
1079     warn_uninitialized = 2;
1080 }
1081
1082 /* Initialize unused warning flags.  */
1083 void
1084 set_Wunused (int setting)
1085 {
1086   warn_unused_function = setting;
1087   warn_unused_label = setting;
1088   /* Unused function parameter warnings are reported when either
1089      ``-Wextra -Wunused'' or ``-Wunused-parameter'' is specified.
1090      Thus, if -Wextra has already been seen, set warn_unused_parameter;
1091      otherwise set maybe_warn_extra_parameter, which will be picked up
1092      by set_Wextra.  */
1093   maybe_warn_unused_parameter = setting;
1094   warn_unused_parameter = (setting && extra_warnings);
1095   warn_unused_variable = setting;
1096   warn_unused_value = setting;
1097 }
1098
1099 /* The following routines are useful in setting all the flags that
1100    -ffast-math and -fno-fast-math imply.  */
1101 void
1102 set_fast_math_flags (int set)
1103 {
1104   flag_trapping_math = !set;
1105   flag_unsafe_math_optimizations = set;
1106   flag_finite_math_only = set;
1107   flag_errno_math = !set;
1108   if (set)
1109     {
1110       flag_signaling_nans = 0;
1111       flag_rounding_math = 0;
1112       flag_cx_limited_range = 1;
1113     }
1114 }
1115
1116 /* Return true iff flags are set as if -ffast-math.  */
1117 bool
1118 fast_math_flags_set_p (void)
1119 {
1120   return (!flag_trapping_math
1121           && flag_unsafe_math_optimizations
1122           && flag_finite_math_only
1123           && !flag_errno_math);
1124 }
1125
1126 /* Handle a debug output -g switch.  EXTENDED is true or false to support
1127    extended output (2 is special and means "-ggdb" was given).  */
1128 static void
1129 set_debug_level (enum debug_info_type type, int extended, const char *arg)
1130 {
1131   static bool type_explicit;
1132
1133   use_gnu_debug_info_extensions = extended;
1134
1135   if (type == NO_DEBUG)
1136     {
1137       if (write_symbols == NO_DEBUG)
1138         {
1139           write_symbols = PREFERRED_DEBUGGING_TYPE;
1140
1141           if (extended == 2)
1142             {
1143 #ifdef DWARF2_DEBUGGING_INFO
1144               write_symbols = DWARF2_DEBUG;
1145 #elif defined DBX_DEBUGGING_INFO
1146               write_symbols = DBX_DEBUG;
1147 #endif
1148             }
1149
1150           if (write_symbols == NO_DEBUG)
1151             warning ("target system does not support debug output");
1152         }
1153     }
1154   else
1155     {
1156       /* Does it conflict with an already selected type?  */
1157       if (type_explicit && write_symbols != NO_DEBUG && type != write_symbols)
1158         error ("debug format \"%s\" conflicts with prior selection",
1159                debug_type_names[type]);
1160       write_symbols = type;
1161       type_explicit = true;
1162     }
1163
1164   /* A debug flag without a level defaults to level 2.  */
1165   if (*arg == '\0')
1166     {
1167       if (!debug_info_level)
1168         debug_info_level = 2;
1169     }
1170   else
1171     {
1172       debug_info_level = integral_argument (arg);
1173       if (debug_info_level == (unsigned int) -1)
1174         error ("unrecognised debug output level \"%s\"", arg);
1175       else if (debug_info_level > 3)
1176         error ("debug output level %s is too high", arg);
1177     }
1178 }
1179
1180 /* Output --help text.  */
1181 static void
1182 print_help (void)
1183 {
1184   size_t i;
1185   const char *p;
1186
1187   GET_ENVIRONMENT (p, "COLUMNS");
1188   if (p)
1189     {
1190       int value = atoi (p);
1191       if (value > 0)
1192         columns = value;
1193     }
1194
1195   puts (_("The following options are language-independent:\n"));
1196
1197   print_filtered_help (CL_COMMON);
1198   print_param_help ();
1199
1200   for (i = 0; lang_names[i]; i++)
1201     {
1202       printf (_("The %s front end recognizes the following options:\n\n"),
1203               lang_names[i]);
1204       print_filtered_help (1U << i);
1205     }
1206
1207   display_target_options ();
1208 }
1209
1210 /* Print the help for --param.  */
1211 static void
1212 print_param_help (void)
1213 {
1214   size_t i;
1215
1216   puts (_("The --param option recognizes the following as parameters:\n"));
1217
1218   for (i = 0; i < LAST_PARAM; i++)
1219     {
1220       const char *help = compiler_params[i].help;
1221       const char *param = compiler_params[i].option;
1222
1223       if (help == NULL || *help == '\0')
1224         help = undocumented_msg;
1225
1226       /* Get the translation.  */
1227       help = _(help);
1228
1229       wrap_help (help, param, strlen (param));
1230     }
1231
1232   putchar ('\n');
1233 }
1234
1235 /* Print help for a specific front-end, etc.  */
1236 void
1237 print_filtered_help (unsigned int flag)
1238 {
1239   unsigned int i, len, filter, indent = 0;
1240   bool duplicates = false;
1241   const char *help, *opt, *tab;
1242   static char *printed;
1243
1244   if (flag == CL_COMMON || flag == CL_TARGET)
1245     {
1246       filter = flag;
1247       if (!printed)
1248         printed = xmalloc (cl_options_count);
1249       memset (printed, 0, cl_options_count);
1250     }
1251   else
1252     {
1253       /* Don't print COMMON options twice.  */
1254       filter = flag | CL_COMMON;
1255
1256       for (i = 0; i < cl_options_count; i++)
1257         {
1258           if ((cl_options[i].flags & filter) != flag)
1259             continue;
1260
1261           /* Skip help for internal switches.  */
1262           if (cl_options[i].flags & CL_UNDOCUMENTED)
1263             continue;
1264
1265           /* Skip switches that have already been printed, mark them to be
1266              listed later.  */
1267           if (printed[i])
1268             {
1269               duplicates = true;
1270               indent = print_switch (cl_options[i].opt_text, indent);
1271             }
1272         }
1273
1274       if (duplicates)
1275         {
1276           putchar ('\n');
1277           putchar ('\n');
1278         }
1279     }
1280
1281   for (i = 0; i < cl_options_count; i++)
1282     {
1283       if ((cl_options[i].flags & filter) != flag)
1284         continue;
1285
1286       /* Skip help for internal switches.  */
1287       if (cl_options[i].flags & CL_UNDOCUMENTED)
1288         continue;
1289
1290       /* Skip switches that have already been printed.  */
1291       if (printed[i])
1292         continue;
1293
1294       printed[i] = true;
1295
1296       help = cl_options[i].help;
1297       if (!help)
1298         help = undocumented_msg;
1299
1300       /* Get the translation.  */
1301       help = _(help);
1302
1303       tab = strchr (help, '\t');
1304       if (tab)
1305         {
1306           len = tab - help;
1307           opt = help;
1308           help = tab + 1;
1309         }
1310       else
1311         {
1312           opt = cl_options[i].opt_text;
1313           len = strlen (opt);
1314         }
1315
1316       wrap_help (help, opt, len);
1317     }
1318
1319   putchar ('\n');
1320 }
1321
1322 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1323    word-wrapped HELP in a second column.  */
1324 static unsigned int
1325 print_switch (const char *text, unsigned int indent)
1326 {
1327   unsigned int len = strlen (text) + 1; /* trailing comma */
1328
1329   if (indent)
1330     {
1331       putchar (',');
1332       if (indent + len > columns)
1333         {
1334           putchar ('\n');
1335           putchar (' ');
1336           indent = 1;
1337         }
1338     }
1339   else
1340     putchar (' ');
1341
1342   putchar (' ');
1343   fputs (text, stdout);
1344
1345   return indent + len + 1;
1346 }
1347
1348 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1349    word-wrapped HELP in a second column.  */
1350 static void
1351 wrap_help (const char *help, const char *item, unsigned int item_width)
1352 {
1353   unsigned int col_width = 27;
1354   unsigned int remaining, room, len;
1355
1356   remaining = strlen (help);
1357
1358   do
1359     {
1360       room = columns - 3 - MAX (col_width, item_width);
1361       if (room > columns)
1362         room = 0;
1363       len = remaining;
1364
1365       if (room < len)
1366         {
1367           unsigned int i;
1368
1369           for (i = 0; help[i]; i++)
1370             {
1371               if (i >= room && len != remaining)
1372                 break;
1373               if (help[i] == ' ')
1374                 len = i;
1375               else if ((help[i] == '-' || help[i] == '/')
1376                        && help[i + 1] != ' '
1377                        && i > 0 && ISALPHA (help[i - 1]))
1378                 len = i + 1;
1379             }
1380         }
1381
1382       printf( "  %-*.*s %.*s\n", col_width, item_width, item, len, help);
1383       item_width = 0;
1384       while (help[len] == ' ')
1385         len++;
1386       help += len;
1387       remaining -= len;
1388     }
1389   while (remaining);
1390 }
1391
1392 /* Return 1 if OPTION is enabled, 0 if it is disabled, or -1 if it isn't
1393    a simple on-off switch.  */
1394
1395 int
1396 option_enabled (const struct cl_option *option)
1397 {
1398   if (option->flag_var)
1399     switch (option->var_cond)
1400       {
1401       case CLVC_BOOLEAN:
1402         return *option->flag_var != 0;
1403
1404       case CLVC_EQUAL:
1405         return *option->flag_var == option->var_value;
1406
1407       case CLVC_BIT_CLEAR:
1408         return (*option->flag_var & option->var_value) == 0;
1409
1410       case CLVC_BIT_SET:
1411         return (*option->flag_var & option->var_value) != 0;
1412       }
1413   return -1;
1414 }