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_sink = 1;
 528       flag_tree_salias = 1;
 529
 530       if (!optimize_size)
 531         {
 532           /* Loop header copying usually increases size of the code.  This used
 533              not to be true, since quite often it is possible to verify that
 534              the condition is satisfied in the first iteration and therefore
 535              to eliminate it.  Jump threading handles these cases now.  */
 536           flag_tree_ch = 1;
 537         }
 538     }
 539
 540   if (optimize >= 2)
 541     {
 542       flag_thread_jumps = 1;
 543       flag_crossjumping = 1;
 544       flag_optimize_sibling_calls = 1;
 545       flag_cse_follow_jumps = 1;
 546       flag_cse_skip_blocks = 1;
 547       flag_gcse = 1;
 548       flag_expensive_optimizations = 1;
 549       flag_strength_reduce = 1;
 550       flag_rerun_cse_after_loop = 1;
 551       flag_rerun_loop_opt = 1;
 552       flag_caller_saves = 1;
 553       flag_force_mem = 1;
 554       flag_peephole2 = 1;
 555 #ifdef INSN_SCHEDULING
 556       flag_schedule_insns = 1;
 557       flag_schedule_insns_after_reload = 1;
 558 #endif
 559       flag_regmove = 1;
 560       flag_strict_aliasing = 1;
 561       flag_delete_null_pointer_checks = 1;
 562       flag_reorder_blocks = 1;
 563       flag_reorder_functions = 1;
 564       flag_unit_at_a_time = 1;
 565
 566       if (!optimize_size)
 567         {
 568           /* PRE tends to generate bigger code.  */
 569           flag_tree_pre = 1;
 570         }
 571     }
 572
 573   if (optimize >= 3)
 574     {
 575       flag_inline_functions = 1;
 576       flag_unswitch_loops = 1;
 577       flag_gcse_after_reload = 1;
 578     }
 579
 580   if (optimize < 2 || optimize_size)
 581     {
 582       align_loops = 1;
 583       align_jumps = 1;
 584       align_labels = 1;
 585       align_functions = 1;
 586
 587       /* Don't reorder blocks when optimizing for size because extra
 588          jump insns may be created; also barrier may create extra padding.
 589
 590          More correctly we should have a block reordering mode that tried
 591          to minimize the combined size of all the jumps.  This would more
 592          or less automatically remove extra jumps, but would also try to
 593          use more short jumps instead of long jumps.  */
 594       flag_reorder_blocks = 0;
 595       flag_reorder_blocks_and_partition = 0;
 596     }
 597
 598   if (optimize_size)
 599     {
 600       /* Inlining of very small functions usually reduces total size.  */
 601       set_param_value ("max-inline-insns-single", 5);
 602       set_param_value ("max-inline-insns-auto", 5);
 603       flag_inline_functions = 1;
 604
 605       /* We want to crossjump as much as possible.  */
 606       set_param_value ("min-crossjump-insns", 1);
 607     }
 608
 609   /* Initialize whether `char' is signed.  */
 610   flag_signed_char = DEFAULT_SIGNED_CHAR;
 611   /* Set this to a special "uninitialized" value.  The actual default is set
 612      after target options have been processed.  */
 613   flag_short_enums = 2;
 614
 615   /* Initialize target_flags before OPTIMIZATION_OPTIONS so the latter can
 616      modify it.  */
 617   target_flags = targetm.default_target_flags;
 618   set_target_switch ("");
 619
 620   /* Unwind tables are always present when a target has ABI-specified unwind
 621      tables, so the default should be ON.  */
 622 #ifdef TARGET_UNWIND_INFO
 623   flag_unwind_tables = TARGET_UNWIND_INFO;
 624 #endif
 625
 626 #ifdef OPTIMIZATION_OPTIONS
 627   /* Allow default optimizations to be specified on a per-machine basis.  */
 628   OPTIMIZATION_OPTIONS (optimize, optimize_size);
 629 #endif
 630
 631   handle_options (argc, argv, lang_mask);
 632
 633   if (flag_pie)
 634     flag_pic = flag_pie;
 635   if (flag_pic && !flag_pie)
 636     flag_shlib = 1;
 637
 638   if (flag_no_inline == 2)
 639     flag_no_inline = 0;
 640   else
 641     flag_really_no_inline = flag_no_inline;
 642
 643   /* Set flag_no_inline before the post_options () hook.  The C front
 644      ends use it to determine tree inlining defaults.  FIXME: such
 645      code should be lang-independent when all front ends use tree
 646      inlining, in which case it, and this condition, should be moved
 647      to the top of process_options() instead.  */
 648   if (optimize == 0)
 649     {
 650       /* Inlining does not work if not optimizing,
 651          so force it not to be done.  */
 652       flag_no_inline = 1;
 653       warn_inline = 0;
 654
 655       /* The c_decode_option function and decode_option hook set
 656          this to `2' if -Wall is used, so we can avoid giving out
 657          lots of errors for people who don't realize what -Wall does.  */
 658       if (warn_uninitialized == 1)
 659         warning ("-Wuninitialized is not supported without -O");
 660     }
 661
 662   if (flag_really_no_inline == 2)
 663     flag_really_no_inline = flag_no_inline;
 664
 665   /* The optimization to partition hot and cold basic blocks into separate
 666      sections of the .o and executable files does not work (currently)
 667      with exception handling.  If flag_exceptions is turned on we need to
 668      turn off the partitioning optimization.  */
 669
 670   if (flag_exceptions && flag_reorder_blocks_and_partition)
 671     {
 672       warning
 673             ("-freorder-blocks-and-partition does not work with exceptions");
 674       flag_reorder_blocks_and_partition = 0;
 675       flag_reorder_blocks = 1;
 676     }
 677
 678   /* The optimization to partition hot and cold basic blocks into
 679      separate sections of the .o and executable files does not currently
 680      work correctly with DWARF debugging turned on.  Until this is fixed
 681      we will disable the optimization when DWARF debugging is set.  */
 682
 683   if (flag_reorder_blocks_and_partition && write_symbols == DWARF2_DEBUG)
 684     {
 685       warning
 686         ("-freorder-blocks-and-partition does not work with -g (currently)");
 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_fdump_:
 822       if (!dump_switch_p (arg))
 823         return 0;
 824       break;
 825
 826     case OPT_ffast_math:
 827       set_fast_math_flags (value);
 828       break;
 829
 830     case OPT_ffixed_:
 831       fix_register (arg, 1, 1);
 832       break;
 833
 834     case OPT_finline_limit_:
 835     case OPT_finline_limit_eq:
 836       set_param_value ("max-inline-insns-single", value / 2);
 837       set_param_value ("max-inline-insns-auto", value / 2);
 838       break;
 839
 840     case OPT_fmessage_length_:
 841       pp_set_line_maximum_length (global_dc->printer, value);
 842       break;
 843
 844     case OPT_fpack_struct_:
 845       if (value <= 0 || (value & (value - 1)) || value > 16)
 846         error("structure alignment must be a small power of two, not %d", value);
 847       else
 848         {
 849           initial_max_fld_align = value;
 850           maximum_field_alignment = value * BITS_PER_UNIT;
 851         }
 852       break;
 853
 854     case OPT_fpeel_loops:
 855       flag_peel_loops_set = true;
 856       break;
 857
 858     case OPT_fprofile_arcs:
 859       profile_arc_flag_set = true;
 860       break;
 861
 862     case OPT_fprofile_use:
 863       if (!flag_branch_probabilities_set)
 864         flag_branch_probabilities = value;
 865       if (!flag_profile_values_set)
 866         flag_profile_values = value;
 867       if (!flag_unroll_loops_set)
 868         flag_unroll_loops = value;
 869       if (!flag_peel_loops_set)
 870         flag_peel_loops = value;
 871       if (!flag_tracer_set)
 872         flag_tracer = value;
 873       if (!flag_value_profile_transformations_set)
 874         flag_value_profile_transformations = value;
 875 #ifdef HAVE_prefetch
 876       if (0 && !flag_speculative_prefetching_set)
 877         flag_speculative_prefetching = value;
 878 #endif
 879       break;
 880
 881     case OPT_fprofile_generate:
 882       if (!profile_arc_flag_set)
 883         profile_arc_flag = value;
 884       if (!flag_profile_values_set)
 885         flag_profile_values = value;
 886       if (!flag_value_profile_transformations_set)
 887         flag_value_profile_transformations = value;
 888       if (!flag_unroll_loops_set)
 889         flag_unroll_loops = value;
 890 #ifdef HAVE_prefetch
 891       if (0 && !flag_speculative_prefetching_set)
 892         flag_speculative_prefetching = value;
 893 #endif
 894       break;
 895
 896     case OPT_fprofile_values:
 897       flag_profile_values_set = true;
 898       break;
 899
 900     case OPT_fvisibility_:
 901       {
 902         if (!strcmp(arg, "default"))
 903           default_visibility = VISIBILITY_DEFAULT;
 904         else if (!strcmp(arg, "internal"))
 905           default_visibility = VISIBILITY_INTERNAL;
 906         else if (!strcmp(arg, "hidden"))
 907           default_visibility = VISIBILITY_HIDDEN;
 908         else if (!strcmp(arg, "protected"))
 909           default_visibility = VISIBILITY_PROTECTED;
 910         else
 911           error ("unrecognised visibility value \"%s\"", arg);
 912       }
 913       break;
 914
 915     case OPT_fvpt:
 916       flag_value_profile_transformations_set = true;
 917       break;
 918
 919     case OPT_fspeculative_prefetching:
 920       flag_speculative_prefetching_set = true;
 921       break;
 922
 923     case OPT_frandom_seed:
 924       /* The real switch is -fno-random-seed.  */
 925       if (value)
 926         return 0;
 927       flag_random_seed = NULL;
 928       break;
 929
 930     case OPT_frandom_seed_:
 931       flag_random_seed = arg;
 932       break;
 933
 934     case OPT_fsched_verbose_:
 935 #ifdef INSN_SCHEDULING
 936       fix_sched_param ("verbose", arg);
 937       break;
 938 #else
 939       return 0;
 940 #endif
 941
 942     case OPT_fsched_stalled_insns_:
 943       flag_sched_stalled_insns = value;
 944       if (flag_sched_stalled_insns == 0)
 945         flag_sched_stalled_insns = -1;
 946       break;
 947
 948     case OPT_fsched_stalled_insns_dep_:
 949       flag_sched_stalled_insns_dep = value;
 950       break;
 951
 952     case OPT_fstack_limit:
 953       /* The real switch is -fno-stack-limit.  */
 954       if (value)
 955         return 0;
 956       stack_limit_rtx = NULL_RTX;
 957       break;
 958
 959     case OPT_fstack_limit_register_:
 960       {
 961         int reg = decode_reg_name (arg);
 962         if (reg < 0)
 963           error ("unrecognized register name \"%s\"", arg);
 964         else
 965           stack_limit_rtx = gen_rtx_REG (Pmode, reg);
 966       }
 967       break;
 968
 969     case OPT_fstack_limit_symbol_:
 970       stack_limit_rtx = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (arg));
 971       break;
 972
 973     case OPT_ftree_vectorizer_verbose_:
 974       vect_set_verbosity_level (arg);
 975       break;
 976
 977     case OPT_ftls_model_:
 978       if (!strcmp (arg, "global-dynamic"))
 979         flag_tls_default = TLS_MODEL_GLOBAL_DYNAMIC;
 980       else if (!strcmp (arg, "local-dynamic"))
 981         flag_tls_default = TLS_MODEL_LOCAL_DYNAMIC;
 982       else if (!strcmp (arg, "initial-exec"))
 983         flag_tls_default = TLS_MODEL_INITIAL_EXEC;
 984       else if (!strcmp (arg, "local-exec"))
 985         flag_tls_default = TLS_MODEL_LOCAL_EXEC;
 986       else
 987         warning ("unknown tls-model \"%s\"", arg);
 988       break;
 989
 990     case OPT_ftracer:
 991       flag_tracer_set = true;
 992       break;
 993
 994     case OPT_funroll_loops:
 995       flag_unroll_loops_set = true;
 996       break;
 997
 998     case OPT_g:
 999       set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg);
1000       break;
1001
1002     case OPT_gcoff:
1003       set_debug_level (SDB_DEBUG, false, arg);
1004       break;
1005
1006     case OPT_gdwarf_2:
1007       set_debug_level (DWARF2_DEBUG, false, arg);
1008       break;
1009
1010     case OPT_ggdb:
1011       set_debug_level (NO_DEBUG, 2, arg);
1012       break;
1013
1014     case OPT_gstabs:
1015     case OPT_gstabs_:
1016       set_debug_level (DBX_DEBUG, code == OPT_gstabs_, arg);
1017       break;
1018
1019     case OPT_gvms:
1020       set_debug_level (VMS_DEBUG, false, arg);
1021       break;
1022
1023     case OPT_gxcoff:
1024     case OPT_gxcoff_:
1025       set_debug_level (XCOFF_DEBUG, code == OPT_gxcoff_, arg);
1026       break;
1027
1028     case OPT_o:
1029       asm_file_name = arg;
1030       break;
1031
1032     case OPT_pedantic_errors:
1033       flag_pedantic_errors = pedantic = 1;
1034       break;
1035
1036     default:
1037       /* If the flag was handled in a standard way, assume the lack of
1038          processing here is intentional.  */
1039       if (cl_options[scode].flag_var)
1040         break;
1041
1042       abort ();
1043     }
1044
1045   return 1;
1046 }
1047
1048 /* Handle --param NAME=VALUE.  */
1049 static void
1050 handle_param (const char *carg)
1051 {
1052   char *equal, *arg;
1053   int value;
1054
1055   arg = xstrdup (carg);
1056   equal = strchr (arg, '=');
1057   if (!equal)
1058     error ("%s: --param arguments should be of the form NAME=VALUE", arg);
1059   else
1060     {
1061       value = integral_argument (equal + 1);
1062       if (value == -1)
1063         error ("invalid --param value %qs", equal + 1);
1064       else
1065         {
1066           *equal = '\0';
1067           set_param_value (arg, value);
1068         }
1069     }
1070
1071   free (arg);
1072 }
1073
1074 /* Handle -W and -Wextra.  */
1075 static void
1076 set_Wextra (int setting)
1077 {
1078   extra_warnings = setting;
1079   warn_unused_value = setting;
1080   warn_unused_parameter = (setting && maybe_warn_unused_parameter);
1081
1082   /* We save the value of warn_uninitialized, since if they put
1083      -Wuninitialized on the command line, we need to generate a
1084      warning about not using it without also specifying -O.  */
1085   if (setting == 0)
1086     warn_uninitialized = 0;
1087   else if (warn_uninitialized != 1)
1088     warn_uninitialized = 2;
1089 }
1090
1091 /* Initialize unused warning flags.  */
1092 void
1093 set_Wunused (int setting)
1094 {
1095   warn_unused_function = setting;
1096   warn_unused_label = setting;
1097   /* Unused function parameter warnings are reported when either
1098      ``-Wextra -Wunused'' or ``-Wunused-parameter'' is specified.
1099      Thus, if -Wextra has already been seen, set warn_unused_parameter;
1100      otherwise set maybe_warn_extra_parameter, which will be picked up
1101      by set_Wextra.  */
1102   maybe_warn_unused_parameter = setting;
1103   warn_unused_parameter = (setting && extra_warnings);
1104   warn_unused_variable = setting;
1105   warn_unused_value = setting;
1106 }
1107
1108 /* The following routines are useful in setting all the flags that
1109    -ffast-math and -fno-fast-math imply.  */
1110 void
1111 set_fast_math_flags (int set)
1112 {
1113   flag_trapping_math = !set;
1114   flag_unsafe_math_optimizations = set;
1115   flag_finite_math_only = set;
1116   flag_errno_math = !set;
1117   if (set)
1118     {
1119       flag_signaling_nans = 0;
1120       flag_rounding_math = 0;
1121       flag_cx_limited_range = 1;
1122     }
1123 }
1124
1125 /* Return true iff flags are set as if -ffast-math.  */
1126 bool
1127 fast_math_flags_set_p (void)
1128 {
1129   return (!flag_trapping_math
1130           && flag_unsafe_math_optimizations
1131           && flag_finite_math_only
1132           && !flag_errno_math);
1133 }
1134
1135 /* Handle a debug output -g switch.  EXTENDED is true or false to support
1136    extended output (2 is special and means "-ggdb" was given).  */
1137 static void
1138 set_debug_level (enum debug_info_type type, int extended, const char *arg)
1139 {
1140   static bool type_explicit;
1141
1142   use_gnu_debug_info_extensions = extended;
1143
1144   if (type == NO_DEBUG)
1145     {
1146       if (write_symbols == NO_DEBUG)
1147         {
1148           write_symbols = PREFERRED_DEBUGGING_TYPE;
1149
1150           if (extended == 2)
1151             {
1152 #ifdef DWARF2_DEBUGGING_INFO
1153               write_symbols = DWARF2_DEBUG;
1154 #elif defined DBX_DEBUGGING_INFO
1155               write_symbols = DBX_DEBUG;
1156 #endif
1157             }
1158
1159           if (write_symbols == NO_DEBUG)
1160             warning ("target system does not support debug output");
1161         }
1162     }
1163   else
1164     {
1165       /* Does it conflict with an already selected type?  */
1166       if (type_explicit && write_symbols != NO_DEBUG && type != write_symbols)
1167         error ("debug format \"%s\" conflicts with prior selection",
1168                debug_type_names[type]);
1169       write_symbols = type;
1170       type_explicit = true;
1171     }
1172
1173   /* A debug flag without a level defaults to level 2.  */
1174   if (*arg == '\0')
1175     {
1176       if (!debug_info_level)
1177         debug_info_level = 2;
1178     }
1179   else
1180     {
1181       debug_info_level = integral_argument (arg);
1182       if (debug_info_level == (unsigned int) -1)
1183         error ("unrecognised debug output level \"%s\"", arg);
1184       else if (debug_info_level > 3)
1185         error ("debug output level %s is too high", arg);
1186     }
1187 }
1188
1189 /* Output --help text.  */
1190 static void
1191 print_help (void)
1192 {
1193   size_t i;
1194   const char *p;
1195
1196   GET_ENVIRONMENT (p, "COLUMNS");
1197   if (p)
1198     {
1199       int value = atoi (p);
1200       if (value > 0)
1201         columns = value;
1202     }
1203
1204   puts (_("The following options are language-independent:\n"));
1205
1206   print_filtered_help (CL_COMMON);
1207   print_param_help ();
1208
1209   for (i = 0; lang_names[i]; i++)
1210     {
1211       printf (_("The %s front end recognizes the following options:\n\n"),
1212               lang_names[i]);
1213       print_filtered_help (1U << i);
1214     }
1215
1216   display_target_options ();
1217 }
1218
1219 /* Print the help for --param.  */
1220 static void
1221 print_param_help (void)
1222 {
1223   size_t i;
1224
1225   puts (_("The --param option recognizes the following as parameters:\n"));
1226
1227   for (i = 0; i < LAST_PARAM; i++)
1228     {
1229       const char *help = compiler_params[i].help;
1230       const char *param = compiler_params[i].option;
1231
1232       if (help == NULL || *help == '\0')
1233         help = undocumented_msg;
1234
1235       /* Get the translation.  */
1236       help = _(help);
1237
1238       wrap_help (help, param, strlen (param));
1239     }
1240
1241   putchar ('\n');
1242 }
1243
1244 /* Print help for a specific front-end, etc.  */
1245 void
1246 print_filtered_help (unsigned int flag)
1247 {
1248   unsigned int i, len, filter, indent = 0;
1249   bool duplicates = false;
1250   const char *help, *opt, *tab;
1251   static char *printed;
1252
1253   if (flag == CL_COMMON || flag == CL_TARGET)
1254     {
1255       filter = flag;
1256       if (!printed)
1257         printed = xmalloc (cl_options_count);
1258       memset (printed, 0, cl_options_count);
1259     }
1260   else
1261     {
1262       /* Don't print COMMON options twice.  */
1263       filter = flag | CL_COMMON;
1264
1265       for (i = 0; i < cl_options_count; i++)
1266         {
1267           if ((cl_options[i].flags & filter) != flag)
1268             continue;
1269
1270           /* Skip help for internal switches.  */
1271           if (cl_options[i].flags & CL_UNDOCUMENTED)
1272             continue;
1273
1274           /* Skip switches that have already been printed, mark them to be
1275              listed later.  */
1276           if (printed[i])
1277             {
1278               duplicates = true;
1279               indent = print_switch (cl_options[i].opt_text, indent);
1280             }
1281         }
1282
1283       if (duplicates)
1284         {
1285           putchar ('\n');
1286           putchar ('\n');
1287         }
1288     }
1289
1290   for (i = 0; i < cl_options_count; i++)
1291     {
1292       if ((cl_options[i].flags & filter) != flag)
1293         continue;
1294
1295       /* Skip help for internal switches.  */
1296       if (cl_options[i].flags & CL_UNDOCUMENTED)
1297         continue;
1298
1299       /* Skip switches that have already been printed.  */
1300       if (printed[i])
1301         continue;
1302
1303       printed[i] = true;
1304
1305       help = cl_options[i].help;
1306       if (!help)
1307         help = undocumented_msg;
1308
1309       /* Get the translation.  */
1310       help = _(help);
1311
1312       tab = strchr (help, '\t');
1313       if (tab)
1314         {
1315           len = tab - help;
1316           opt = help;
1317           help = tab + 1;
1318         }
1319       else
1320         {
1321           opt = cl_options[i].opt_text;
1322           len = strlen (opt);
1323         }
1324
1325       wrap_help (help, opt, len);
1326     }
1327
1328   putchar ('\n');
1329 }
1330
1331 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1332    word-wrapped HELP in a second column.  */
1333 static unsigned int
1334 print_switch (const char *text, unsigned int indent)
1335 {
1336   unsigned int len = strlen (text) + 1; /* trailing comma */
1337
1338   if (indent)
1339     {
1340       putchar (',');
1341       if (indent + len > columns)
1342         {
1343           putchar ('\n');
1344           putchar (' ');
1345           indent = 1;
1346         }
1347     }
1348   else
1349     putchar (' ');
1350
1351   putchar (' ');
1352   fputs (text, stdout);
1353
1354   return indent + len + 1;
1355 }
1356
1357 /* Output ITEM, of length ITEM_WIDTH, in the left column, followed by
1358    word-wrapped HELP in a second column.  */
1359 static void
1360 wrap_help (const char *help, const char *item, unsigned int item_width)
1361 {
1362   unsigned int col_width = 27;
1363   unsigned int remaining, room, len;
1364
1365   remaining = strlen (help);
1366
1367   do
1368     {
1369       room = columns - 3 - MAX (col_width, item_width);
1370       if (room > columns)
1371         room = 0;
1372       len = remaining;
1373
1374       if (room < len)
1375         {
1376           unsigned int i;
1377
1378           for (i = 0; help[i]; i++)
1379             {
1380               if (i >= room && len != remaining)
1381                 break;
1382               if (help[i] == ' ')
1383                 len = i;
1384               else if ((help[i] == '-' || help[i] == '/')
1385                        && help[i + 1] != ' '
1386                        && i > 0 && ISALPHA (help[i - 1]))
1387                 len = i + 1;
1388             }
1389         }
1390
1391       printf( "  %-*.*s %.*s\n", col_width, item_width, item, len, help);
1392       item_width = 0;
1393       while (help[len] == ' ')
1394         len++;
1395       help += len;
1396       remaining -= len;
1397     }
1398   while (remaining);
1399 }
1400
1401 /* Return 1 if OPTION is enabled, 0 if it is disabled, or -1 if it isn't
1402    a simple on-off switch.  */
1403
1404 int
1405 option_enabled (const struct cl_option *option)
1406 {
1407   if (option->flag_var)
1408     switch (option->var_cond)
1409       {
1410       case CLVC_BOOLEAN:
1411         return *option->flag_var != 0;
1412
1413       case CLVC_EQUAL:
1414         return *option->flag_var == option->var_value;
1415
1416       case CLVC_BIT_CLEAR:
1417         return (*option->flag_var & option->var_value) == 0;
1418
1419       case CLVC_BIT_SET:
1420         return (*option->flag_var & option->var_value) != 0;
1421       }
1422   return -1;
1423 }