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 (0, "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 (0, "-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   if (flag_reorder_blocks_and_partition
 683       && !targetm.have_named_sections)
 684     {
 685       inform
 686        ("-freorder-blocks-and-partition does not work on this architecture.");
 687       flag_reorder_blocks_and_partition = 0;
 688       flag_reorder_blocks = 1;
 689     }
 690 }
 691
 692 /* Handle target- and language-independent options.  Return zero to
 693    generate an "unknown option" message.  Only options that need
 694    extra handling need to be listed here; if you simply want
 695    VALUE assigned to a variable, it happens automatically.  */
 696
 697 static int
 698 common_handle_option (size_t scode, const char *arg, int value)
 699 {
 700   enum opt_code code = (enum opt_code) scode;
 701
 702   switch (code)
 703     {
 704     case OPT__help:
 705       print_help ();
 706       exit_after_options = true;
 707       break;
 708
 709     case OPT__param:
 710       handle_param (arg);
 711       break;
 712
 713     case OPT__target_help:
 714       display_target_options ();
 715       exit_after_options = true;
 716       break;
 717
 718     case OPT__version:
 719       print_version (stderr, "");
 720       exit_after_options = true;
 721       break;
 722
 723     case OPT_G:
 724       g_switch_value = value;
 725       g_switch_set = true;
 726       break;
 727
 728     case OPT_O:
 729     case OPT_Os:
 730       /* Currently handled in a prescan.  */
 731       break;
 732
 733     case OPT_W:
 734       /* For backward compatibility, -W is the same as -Wextra.  */
 735       set_Wextra (value);
 736       break;
 737
 738     case OPT_Wextra:
 739       set_Wextra (value);
 740       break;
 741
 742     case OPT_Wlarger_than_:
 743       larger_than_size = value;
 744       warn_larger_than = value != -1;
 745       break;
 746
 747     case OPT_Wstrict_aliasing:
 748     case OPT_Wstrict_aliasing_:
 749       warn_strict_aliasing = value;
 750       break;
 751
 752     case OPT_Wunused:
 753       set_Wunused (value);
 754       break;
 755
 756     case OPT_aux_info:
 757     case OPT_aux_info_:
 758       aux_info_file_name = arg;
 759       flag_gen_aux_info = 1;
 760       break;
 761
 762     case OPT_auxbase:
 763       aux_base_name = arg;
 764       break;
 765
 766     case OPT_auxbase_strip:
 767       {
 768         char *tmp = xstrdup (arg);
 769         strip_off_ending (tmp, strlen (tmp));
 770         if (tmp[0])
 771           aux_base_name = tmp;
 772       }
 773       break;
 774
 775     case OPT_d:
 776       decode_d_option (arg);
 777       break;
 778
 779     case OPT_dumpbase:
 780       dump_base_name = arg;
 781       break;
 782
 783     case OPT_falign_functions_:
 784       align_functions = value;
 785       break;
 786
 787     case OPT_falign_jumps_:
 788       align_jumps = value;
 789       break;
 790
 791     case OPT_falign_labels_:
 792       align_labels = value;
 793       break;
 794
 795     case OPT_falign_loops_:
 796       align_loops = value;
 797       break;
 798
 799     case OPT_fbranch_probabilities:
 800       flag_branch_probabilities_set = true;
 801       break;
 802
 803     case OPT_fcall_used_:
 804       fix_register (arg, 0, 1);
 805       break;
 806
 807     case OPT_fcall_saved_:
 808       fix_register (arg, 0, 0);
 809       break;
 810
 811     case OPT_fdiagnostics_show_location_:
 812       if (!strcmp (arg, "once"))
 813         diagnostic_prefixing_rule (global_dc) = DIAGNOSTICS_SHOW_PREFIX_ONCE;
 814       else if (!strcmp (arg, "every-line"))
 815         diagnostic_prefixing_rule (global_dc)
 816           = DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE;
 817       else
 818         return 0;
 819       break;
 820
 821     case OPT_fdiagnostics_show_option:
 822       global_dc->show_option_requested = true;
 823       break;
 824
 825     case OPT_fdump_:
 826       if (!dump_switch_p (arg))
 827         return 0;
 828       break;
 829
 830     case OPT_ffast_math:
 831       set_fast_math_flags (value);
 832       break;
 833
 834     case OPT_ffixed_:
 835       fix_register (arg, 1, 1);
 836       break;
 837
 838     case OPT_finline_limit_:
 839     case OPT_finline_limit_eq:
 840       set_param_value ("max-inline-insns-single", value / 2);
 841       set_param_value ("max-inline-insns-auto", value / 2);
 842       break;
 843
 844     case OPT_fmessage_length_:
 845       pp_set_line_maximum_length (global_dc->printer, value);
 846       break;
 847
 848     case OPT_fpack_struct_:
 849       if (value <= 0 || (value & (value - 1)) || value > 16)
 850         error("structure alignment must be a small power of two, not %d", value);
 851       else
 852         {
 853           initial_max_fld_align = value;
 854           maximum_field_alignment = value * BITS_PER_UNIT;
 855         }
 856       break;
 857
 858     case OPT_fpeel_loops:
 859       flag_peel_loops_set = true;
 860       break;
 861
 862     case OPT_fprofile_arcs:
 863       profile_arc_flag_set = true;
 864       break;
 865
 866     case OPT_fprofile_use:
 867       if (!flag_branch_probabilities_set)
 868         flag_branch_probabilities = value;
 869       if (!flag_profile_values_set)
 870         flag_profile_values = value;
 871       if (!flag_unroll_loops_set)
 872         flag_unroll_loops = value;
 873       if (!flag_peel_loops_set)
 874         flag_peel_loops = value;
 875       if (!flag_tracer_set)
 876         flag_tracer = value;
 877       if (!flag_value_profile_transformations_set)
 878         flag_value_profile_transformations = value;
 879 #ifdef HAVE_prefetch
 880       if (0 && !flag_speculative_prefetching_set)
 881         flag_speculative_prefetching = value;
 882 #endif
 883       break;
 884
 885     case OPT_fprofile_generate:
 886       if (!profile_arc_flag_set)
 887         profile_arc_flag = value;
 888       if (!flag_profile_values_set)
 889         flag_profile_values = value;
 890       if (!flag_value_profile_transformations_set)
 891         flag_value_profile_transformations = value;
 892       if (!flag_unroll_loops_set)
 893         flag_unroll_loops = value;
 894 #ifdef HAVE_prefetch
 895       if (0 && !flag_speculative_prefetching_set)
 896         flag_speculative_prefetching = value;
 897 #endif
 898       break;
 899
 900     case OPT_fprofile_values:
 901       flag_profile_values_set = true;
 902       break;
 903
 904     case OPT_fvisibility_:
 905       {
 906         if (!strcmp(arg, "default"))
 907           default_visibility = VISIBILITY_DEFAULT;
 908         else if (!strcmp(arg, "internal"))
 909           default_visibility = VISIBILITY_INTERNAL;
 910         else if (!strcmp(arg, "hidden"))
 911           default_visibility = VISIBILITY_HIDDEN;
 912         else if (!strcmp(arg, "protected"))
 913           default_visibility = VISIBILITY_PROTECTED;
 914         else
 915           error ("unrecognised visibility value \"%s\"", arg);
 916       }
 917       break;
 918
 919     case OPT_fvpt:
 920       flag_value_profile_transformations_set = true;
 921       break;
 922
 923     case OPT_fspeculative_prefetching:
 924       flag_speculative_prefetching_set = true;
 925       break;
 926
 927     case OPT_frandom_seed:
 928       /* The real switch is -fno-random-seed.  */
 929       if (value)
 930         return 0;
 931       flag_random_seed = NULL;
 932       break;
 933
 934     case OPT_frandom_seed_:
 935       flag_random_seed = arg;
 936       break;
 937
 938     case OPT_fsched_verbose_:
 939 #ifdef INSN_SCHEDULING
 940       fix_sched_param ("verbose", arg);
 941       break;
 942 #else
 943       return 0;
 944 #endif
 945
 946     case OPT_fsched_stalled_insns_:
 947       flag_sched_stalled_insns = value;
 948       if (flag_sched_stalled_insns == 0)
 949         flag_sched_stalled_insns = -1;
 950       break;
 951
 952     case OPT_fsched_stalled_insns_dep_:
 953       flag_sched_stalled_insns_dep = value;
 954       break;
 955
 956     case OPT_fstack_limit:
 957       /* The real switch is -fno-stack-limit.  */
 958       if (value)
 959         return 0;
 960       stack_limit_rtx = NULL_RTX;
 961       break;
 962
 963     case OPT_fstack_limit_register_:
 964       {
 965         int reg = decode_reg_name (arg);
 966         if (reg < 0)
 967           error ("unrecognized register name \"%s\"", arg);
 968         else
 969           stack_limit_rtx = gen_rtx_REG (Pmode, reg);
 970       }
 971       break;
 972
 973     case OPT_fstack_limit_symbol_:
 974       stack_limit_rtx = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (arg));
 975       break;
 976
 977     case OPT_ftree_vectorizer_verbose_:
 978       vect_set_verbosity_level (arg);
 979       break;
 980
 981     case OPT_ftls_model_:
 982       if (!strcmp (arg, "global-dynamic"))
 983         flag_tls_default = TLS_MODEL_GLOBAL_DYNAMIC;
 984       else if (!strcmp (arg, "local-dynamic"))
 985         flag_tls_default = TLS_MODEL_LOCAL_DYNAMIC;
 986       else if (!strcmp (arg, "initial-exec"))
 987         flag_tls_default = TLS_MODEL_INITIAL_EXEC;
 988       else if (!strcmp (arg, "local-exec"))
 989         flag_tls_default = TLS_MODEL_LOCAL_EXEC;
 990       else
 991         warning (0, "unknown tls-model \"%s\"", arg);
 992       break;
 993
 994     case OPT_ftracer:
 995       flag_tracer_set = true;
 996       break;
 997
 998     case OPT_funroll_loops:
 999       flag_unroll_loops_set = true;
1000       break;
1001
1002     case OPT_g:
1003       set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg);
1004       break;
1005
1006     case OPT_gcoff:
1007       set_debug_level (SDB_DEBUG, false, arg);
1008       break;
1009
1010     case OPT_gdwarf_2:
1011       set_debug_level (DWARF2_DEBUG, false, arg);
1012       break;
1013
1014     case OPT_ggdb:
1015       set_debug_level (NO_DEBUG, 2, arg);
1016       break;
1017
1018     case OPT_gstabs:
1019     case OPT_gstabs_:
1020       set_debug_level (DBX_DEBUG, code == OPT_gstabs_, arg);
1021       break;
1022
1023     case OPT_gvms:
1024       set_debug_level (VMS_DEBUG, false, arg);
1025       break;
1026
1027     case OPT_gxcoff:
1028     case OPT_gxcoff_:
1029       set_debug_level (XCOFF_DEBUG, code == OPT_gxcoff_, arg);
1030       break;
1031
1032     case OPT_o:
1033       asm_file_name = arg;
1034       break;
1035
1036     case OPT_pedantic_errors:
1037       flag_pedantic_errors = pedantic = 1;
1038       break;
1039
1040     default:
1041       /* If the flag was handled in a standard way, assume the lack of
1042          processing here is intentional.  */
1043       gcc_assert (cl_options[scode].flag_var);
1044       break;
1045     }
1046
1047   return 1;
1048 }
1049
1050 /* Handle --param NAME=VALUE.  */
1051 static void
1052 handle_param (const char *carg)
1053 {
1054   char *equal, *arg;
1055   int value;
1056
1057   arg = xstrdup (carg);
1058   equal = strchr (arg, '=');
1059   if (!equal)
1060     error ("%s: --param arguments should be of the form NAME=VALUE", arg);
1061   else
1062     {
1063       value = integral_argument (equal + 1);
1064       if (value == -1)
1065         error ("invalid --param value %qs", equal + 1);
1066       else
1067         {
1068           *equal = '\0';
1069           set_param_value (arg, value);
1070         }
1071     }
1072
1073   free (arg);
1074 }
1075
1076 /* Handle -W and -Wextra.  */
1077 static void
1078 set_Wextra (int setting)
1079 {
1080   extra_warnings = setting;
1081   warn_unused_value = setting;
1082   warn_unused_parameter = (setting && maybe_warn_unused_parameter);
1083
1084   /* We save the value of warn_uninitialized, since if they put
1085      -Wuninitialized on the command line, we need to generate a
1086      warning about not using it without also specifying -O.  */
1087   if (setting == 0)
1088     warn_uninitialized = 0;
1089   else if (warn_uninitialized != 1)
1090     warn_uninitialized = 2;
1091 }
1092
1093 /* Initialize unused warning flags.  */
1094 void
1095 set_Wunused (int setting)
1096 {
1097   warn_unused_function = setting;
1098   warn_unused_label = setting;
1099   /* Unused function parameter warnings are reported when either
1100      ``-Wextra -Wunused'' or ``-Wunused-parameter'' is specified.
1101      Thus, if -Wextra has already been seen, set warn_unused_parameter;
1102      otherwise set maybe_warn_extra_parameter, which will be picked up
1103      by set_Wextra.  */
1104   maybe_warn_unused_parameter = setting;
1105   warn_unused_parameter = (setting && extra_warnings);
1106   warn_unused_variable = setting;
1107   warn_unused_value = setting;
1108 }
1109
1110 /* The following routines are useful in setting all the flags that
1111    -ffast-math and -fno-fast-math imply.  */
1112 void
1113 set_fast_math_flags (int set)
1114 {
1115   flag_trapping_math = !set;
1116   flag_unsafe_math_optimizations = set;
1117   flag_finite_math_only = set;
1118   flag_errno_math = !set;
1119   if (set)
1120     {
1121       flag_signaling_nans = 0;
1122       flag_rounding_math = 0;
1123       flag_cx_limited_range = 1;
1124     }
1125 }
1126
1127 /* Return true iff flags are set as if -ffast-math.  */
1128 bool
1129 fast_math_flags_set_p (void)
1130 {
1131   return (!flag_trapping_math
1132           && flag_unsafe_math_optimizations
1133           && flag_finite_math_only
1134           && !flag_errno_math);
1135 }
1136
1137 /* Handle a debug output -g switch.  EXTENDED is true or false to support
1138    extended output (2 is special and means "-ggdb" was given).  */
1139 static void
1140 set_debug_level (enum debug_info_type type, int extended, const char *arg)
1141 {
1142   static bool type_explicit;
1143
1144   use_gnu_debug_info_extensions = extended;
1145
1146   if (type == NO_DEBUG)
1147     {
1148       if (write_symbols == NO_DEBUG)
1149         {
1150           write_symbols = PREFERRED_DEBUGGING_TYPE;
1151
1152           if (extended == 2)
1153             {
1154 #ifdef DWARF2_DEBUGGING_INFO
1155               write_symbols = DWARF2_DEBUG;
1156 #elif defined DBX_DEBUGGING_INFO
1157               write_symbols = DBX_DEBUG;
1158 #endif
1159             }
1160
1161           if (write_symbols == NO_DEBUG)
1162             warning (0, "target system does not support debug output");
1163         }
1164     }
1165   else
1166     {
1167       /* Does it conflict with an already selected type?  */
1168       if (type_explicit && write_symbols != NO_DEBUG && type != write_symbols)
1169         error ("debug format \"%s\" conflicts with prior selection",
1170                debug_type_names[type]);
1171       write_symbols = type;
1172       type_explicit = true;
1173     }
1174
1175   /* A debug flag without a level defaults to level 2.  */
1176   if (*arg == '\0')
1177     {
1178       if (!debug_info_level)
1179         debug_info_level = 2;
1180     }
1181   else
1182     {
1183       debug_info_level = integral_argument (arg);
1184       if (debug_info_level == (unsigned int) -1)
1185         error ("unrecognised debug output level \"%s\"", arg);
1186       else if (debug_info_level > 3)
1187         error ("debug output level %s is too high", arg);
1188     }
1189 }
1190
1191 /* Output --help text.  */
1192 static void
1193 print_help (void)
1194 {
1195   size_t i;
1196   const char *p;
1197
1198   GET_ENVIRONMENT (p, "COLUMNS");
1199   if (p)
1200     {
1201       int value = atoi (p);
1202       if (value > 0)
1203         columns = value;
1204     }
1205
1206   puts (_("The following options are language-independent:\n"));
1207
1208   print_filtered_help (CL_COMMON);
1209   print_param_help ();
1210
1211   for (i = 0; lang_names[i]; i++)
1212     {
1213       printf (_("The %s front end recognizes the following options:\n\n"),
1214               lang_names[i]);
1215       print_filtered_help (1U << i);
1216     }
1217
1218   display_target_options ();
1219 }
1220
1221 /* Print the help for --param.  */
1222 static void
1223 print_param_help (void)
1224 {
1225   size_t i;
1226
1227   puts (_("The --param option recognizes the following as parameters:\n"));
1228
1229   for (i = 0; i < LAST_PARAM; i++)
1230     {
1231       const char *help = compiler_params[i].help;
1232       const char *param = compiler_params[i].option;
1233
1234       if (help == NULL || *help == '\0')
1235         help = undocumented_msg;
1236
1237       /* Get the translation.  */
1238       help = _(help);
1239
1240       wrap_help (help, param, strlen (param));
1241     }
1242
1243   putchar ('\n');
1244 }
1245
1246 /* Print help for a specific front-end, etc.  */
1247 void
1248 print_filtered_help (unsigned int flag)
1249 {
1250   unsigned int i, len, filter, indent = 0;
1251   bool duplicates = false;
1252   const char *help, *opt, *tab;
1253   static char *printed;
1254
1255   if (flag == CL_COMMON || flag == CL_TARGET)
1256     {
1257       filter = flag;
1258       if (!printed)
1259         printed = xmalloc (cl_options_count);
1260       memset (printed, 0, cl_options_count);
1261     }
1262   else
1263     {
1264       /* Don't print COMMON options twice.  */
1265       filter = flag | CL_COMMON;
1266
1267       for (i = 0; i < cl_options_count; i++)
1268         {
1269           if ((cl_options[i].flags & filter) != flag)
1270             continue;
1271
1272           /* Skip help for internal switches.  */
1273           if (cl_options[i].flags & CL_UNDOCUMENTED)
1274             continue;
1275
1276           /* Skip switches that have already been printed, mark them to be
1277              listed later.  */
1278           if (printed[i])
1279             {
1280               duplicates = true;
1281               indent = print_switch (cl_options[i].opt_text, indent);
1282             }
1283         }
1284
1285       if (duplicates)
1286         {
1287           putchar ('\n');
1288           putchar ('\n');
1289         }
1290     }
1291
1292   for (i = 0; i < cl_options_count; i++)
1293     {
1294       if ((cl_options[i].flags & filter) != flag)
1295         continue;
1296
1297       /* Skip help for internal switches.  */
1298       if (cl_options[i].flags & CL_UNDOCUMENTED)
1299         continue;
1300
1301       /* Skip switches that have already been printed.  */
1302       if (printed[i])
1303         continue;
1304
1305       printed[i] = true;
1306
1307       help = cl_options[i].help;
1308       if (!help)
1309         help = undocumented_msg;
1310
1311       /* Get the translation.  */
1312       help = _(help);
1313
1314       tab = strchr (help, '\t');
1315       if (tab)
1316         {
1317           len = tab - help;
1318           opt = help;
1319           help = tab + 1;
1320         }
1321       else
1322         {
1323           opt = cl_options[i].opt_text;
1324           len = strlen (opt);
1325         }
1326
1327       wrap_help (help, opt, len);
1328     }
1329
1330   putchar ('\n');
1331 }
1332
1333 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1334    word-wrapped HELP in a second column.  */
1335 static unsigned int
1336 print_switch (const char *text, unsigned int indent)
1337 {
1338   unsigned int len = strlen (text) + 1; /* trailing comma */
1339
1340   if (indent)
1341     {
1342       putchar (',');
1343       if (indent + len > columns)
1344         {
1345           putchar ('\n');
1346           putchar (' ');
1347           indent = 1;
1348         }
1349     }
1350   else
1351     putchar (' ');
1352
1353   putchar (' ');
1354   fputs (text, stdout);
1355
1356   return indent + len + 1;
1357 }
1358
1359 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1360    word-wrapped HELP in a second column.  */
1361 static void
1362 wrap_help (const char *help, const char *item, unsigned int item_width)
1363 {
1364   unsigned int col_width = 27;
1365   unsigned int remaining, room, len;
1366
1367   remaining = strlen (help);
1368
1369   do
1370     {
1371       room = columns - 3 - MAX (col_width, item_width);
1372       if (room > columns)
1373         room = 0;
1374       len = remaining;
1375
1376       if (room < len)
1377         {
1378           unsigned int i;
1379
1380           for (i = 0; help[i]; i++)
1381             {
1382               if (i >= room && len != remaining)
1383                 break;
1384               if (help[i] == ' ')
1385                 len = i;
1386               else if ((help[i] == '-' || help[i] == '/')
1387                        && help[i + 1] != ' '
1388                        && i > 0 && ISALPHA (help[i - 1]))
1389                 len = i + 1;
1390             }
1391         }
1392
1393       printf( "  %-*.*s %.*s\n", col_width, item_width, item, len, help);
1394       item_width = 0;
1395       while (help[len] == ' ')
1396         len++;
1397       help += len;
1398       remaining -= len;
1399     }
1400   while (remaining);
1401 }
1402
1403 /* Return 1 if OPTION is enabled, 0 if it is disabled, or -1 if it isn't
1404    a simple on-off switch.  */
1405
1406 int
1407 option_enabled (int opt_idx)
1408 {
1409   const struct cl_option *option = &(cl_options[opt_idx]);
1410   if (option->flag_var)
1411     switch (option->var_cond)
1412       {
1413       case CLVC_BOOLEAN:
1414         return *option->flag_var != 0;
1415
1416       case CLVC_EQUAL:
1417         return *option->flag_var == option->var_value;
1418
1419       case CLVC_BIT_CLEAR:
1420         return (*option->flag_var & option->var_value) == 0;
1421
1422       case CLVC_BIT_SET:
1423         return (*option->flag_var & option->var_value) != 0;
1424       }
1425   return -1;
1426 }