gcc/opts.c

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