gcc/fortran/options.c

   1 /* Parse and display command line options.
   2    Copyright (C) 2000-2018 Free Software Foundation, Inc.
   3    Contributed by Andy Vaught
   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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "target.h"
  25 #include "tree.h"
  26 #include "gfortran.h"
  27 #include "diagnostic.h" /* For global_dc.  */
  28 #include "opts.h"
  29 #include "toplev.h"  /* For save_decoded_options.  */
  30 #include "cpp.h"
  31 #include "langhooks.h"
  32
  33 gfc_option_t gfc_option;
  34
  35
  36 /* Set flags that control warnings and errors for different
  37    Fortran standards to their default values.  Keep in sync with
  38    libgfortran/runtime/compile_options.c (init_compile_options).  */
  39
  40 static void
  41 set_default_std_flags (void)
  42 {
  43   gfc_option.allow_std = GFC_STD_F95_OBS | GFC_STD_F95_DEL
  44     | GFC_STD_F2003 | GFC_STD_F2008 | GFC_STD_F95 | GFC_STD_F77
  45     | GFC_STD_F2008_OBS | GFC_STD_GNU | GFC_STD_LEGACY
  46     | GFC_STD_F2018 | GFC_STD_F2018_DEL | GFC_STD_F2018_OBS;
  47   gfc_option.warn_std = GFC_STD_F2018_DEL | GFC_STD_F95_DEL | GFC_STD_LEGACY;
  48 }
  49
  50
  51 /* Set all the DEC extension flags.  */
  52
  53 static void
  54 set_dec_flags (int value)
  55 {
  56   if (value)
  57     {
  58       /* Allow legacy code without warnings.  */
  59       gfc_option.allow_std |= GFC_STD_F95_OBS | GFC_STD_F95_DEL
  60         | GFC_STD_GNU | GFC_STD_LEGACY;
  61       gfc_option.warn_std &= ~(GFC_STD_LEGACY | GFC_STD_F95_DEL);
  62     }
  63
  64   /* Set other DEC compatibility extensions.  */
  65   flag_dollar_ok |= value;
  66   flag_cray_pointer |= value;
  67   flag_dec_structure |= value;
  68   flag_dec_intrinsic_ints |= value;
  69   flag_dec_static |= value;
  70   flag_dec_math |= value;
  71 }
  72
  73
  74 /* Return language mask for Fortran options.  */
  75
  76 unsigned int
  77 gfc_option_lang_mask (void)
  78 {
  79   return CL_Fortran;
  80 }
  81
  82 /* Initialize options structure OPTS.  */
  83
  84 void
  85 gfc_init_options_struct (struct gcc_options *opts)
  86 {
  87   opts->x_flag_errno_math = 0;
  88   opts->frontend_set_flag_errno_math = true;
  89   opts->x_flag_associative_math = -1;
  90   opts->frontend_set_flag_associative_math = true;
  91 }
  92
  93 /* Get ready for options handling. Keep in sync with
  94    libgfortran/runtime/compile_options.c (init_compile_options).  */
  95
  96 void
  97 gfc_init_options (unsigned int decoded_options_count,
  98                   struct cl_decoded_option *decoded_options)
  99 {
 100   gfc_source_file = NULL;
 101   gfc_option.module_dir = NULL;
 102   gfc_option.source_form = FORM_UNKNOWN;
 103   gfc_option.max_continue_fixed = 255;
 104   gfc_option.max_continue_free = 255;
 105   gfc_option.max_identifier_length = GFC_MAX_SYMBOL_LEN;
 106   gfc_option.max_errors = 25;
 107
 108   gfc_option.flag_preprocessed = 0;
 109   gfc_option.flag_d_lines = -1;
 110   gfc_option.flag_init_integer = GFC_INIT_INTEGER_OFF;
 111   gfc_option.flag_init_integer_value = 0;
 112   gfc_option.flag_init_logical = GFC_INIT_LOGICAL_OFF;
 113   gfc_option.flag_init_character = GFC_INIT_CHARACTER_OFF;
 114   gfc_option.flag_init_character_value = (char)0;
 115
 116   gfc_option.fpe = 0;
 117   /* All except GFC_FPE_INEXACT.  */
 118   gfc_option.fpe_summary = GFC_FPE_INVALID | GFC_FPE_DENORMAL
 119                            | GFC_FPE_ZERO | GFC_FPE_OVERFLOW
 120                            | GFC_FPE_UNDERFLOW;
 121   gfc_option.rtcheck = 0;
 122
 123   /* ??? Wmissing-include-dirs is disabled by default in C/C++ but
 124      enabled by default in Fortran.  Ideally, we should express this
 125      in .opt, but that is not supported yet.  */
 126   if (!global_options_set.x_cpp_warn_missing_include_dirs)
 127     global_options.x_cpp_warn_missing_include_dirs = 1;
 128
 129   set_dec_flags (0);
 130
 131   set_default_std_flags ();
 132
 133   /* Initialize cpp-related options.  */
 134   gfc_cpp_init_options (decoded_options_count, decoded_options);
 135   gfc_diagnostics_init ();
 136 }
 137
 138
 139 /* Determine the source form from the filename extension.  We assume
 140    case insensitivity.  */
 141
 142 static gfc_source_form
 143 form_from_filename (const char *filename)
 144 {
 145   static const struct
 146   {
 147     const char *extension;
 148     gfc_source_form form;
 149   }
 150   exttype[] =
 151   {
 152     {
 153     ".f90", FORM_FREE}
 154     ,
 155     {
 156     ".f95", FORM_FREE}
 157     ,
 158     {
 159     ".f03", FORM_FREE}
 160     ,
 161     {
 162     ".f08", FORM_FREE}
 163     ,
 164     {
 165     ".f", FORM_FIXED}
 166     ,
 167     {
 168     ".for", FORM_FIXED}
 169     ,
 170     {
 171     ".ftn", FORM_FIXED}
 172     ,
 173     {
 174     "", FORM_UNKNOWN}
 175   };            /* sentinel value */
 176
 177   gfc_source_form f_form;
 178   const char *fileext;
 179   int i;
 180
 181   /* Find end of file name.  Note, filename is either a NULL pointer or
 182      a NUL terminated string.  */
 183   i = 0;
 184   while (filename[i] != '\0')
 185     i++;
 186
 187   /* Find last period.  */
 188   while (i >= 0 && (filename[i] != '.'))
 189     i--;
 190
 191   /* Did we see a file extension?  */
 192   if (i < 0)
 193     return FORM_UNKNOWN; /* Nope  */
 194
 195   /* Get file extension and compare it to others.  */
 196   fileext = &(filename[i]);
 197
 198   i = -1;
 199   f_form = FORM_UNKNOWN;
 200   do
 201     {
 202       i++;
 203       if (strcasecmp (fileext, exttype[i].extension) == 0)
 204         {
 205           f_form = exttype[i].form;
 206           break;
 207         }
 208     }
 209   while (exttype[i].form != FORM_UNKNOWN);
 210
 211   return f_form;
 212 }
 213
 214
 215 /* Finalize commandline options.  */
 216
 217 bool
 218 gfc_post_options (const char **pfilename)
 219 {
 220   const char *filename = *pfilename, *canon_source_file = NULL;
 221   char *source_path;
 222   int i;
 223
 224   /* Excess precision other than "fast" requires front-end
 225      support.  */
 226   if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD)
 227     sorry ("-fexcess-precision=standard for Fortran");
 228   flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
 229
 230   /* Fortran allows associative math - but we cannot reassociate if
 231      we want traps or signed zeros. Cf. also flag_protect_parens.  */
 232   if (flag_associative_math == -1)
 233     flag_associative_math = (!flag_trapping_math && !flag_signed_zeros);
 234
 235   if (flag_protect_parens == -1)
 236     flag_protect_parens = !optimize_fast;
 237
 238   /* -Ofast sets implies -fstack-arrays unless an explicit size is set for
 239      stack arrays.  */
 240   if (flag_stack_arrays == -1 && flag_max_stack_var_size == -2)
 241     flag_stack_arrays = optimize_fast;
 242
 243   /* By default, disable (re)allocation during assignment for -std=f95,
 244      and enable it for F2003/F2008/GNU/Legacy.  */
 245   if (flag_realloc_lhs == -1)
 246     {
 247       if (gfc_option.allow_std & GFC_STD_F2003)
 248         flag_realloc_lhs = 1;
 249       else
 250         flag_realloc_lhs = 0;
 251     }
 252
 253   /* -fbounds-check is equivalent to -fcheck=bounds */
 254   if (flag_bounds_check)
 255     gfc_option.rtcheck |= GFC_RTCHECK_BOUNDS;
 256
 257   if (flag_compare_debug)
 258     flag_dump_fortran_original = 0;
 259
 260   /* Make -fmax-errors visible to gfortran's diagnostic machinery.  */
 261   if (global_options_set.x_flag_max_errors)
 262     gfc_option.max_errors = flag_max_errors;
 263
 264   /* Verify the input file name.  */
 265   if (!filename || strcmp (filename, "-") == 0)
 266     {
 267       filename = "";
 268     }
 269
 270   if (gfc_option.flag_preprocessed)
 271     {
 272       /* For preprocessed files, if the first tokens are of the form # NUM.
 273          handle the directives so we know the original file name.  */
 274       gfc_source_file = gfc_read_orig_filename (filename, &canon_source_file);
 275       if (gfc_source_file == NULL)
 276         gfc_source_file = filename;
 277       else
 278         *pfilename = gfc_source_file;
 279     }
 280   else
 281     gfc_source_file = filename;
 282
 283   if (canon_source_file == NULL)
 284     canon_source_file = gfc_source_file;
 285
 286   /* Adds the path where the source file is to the list of include files.  */
 287
 288   i = strlen (canon_source_file);
 289   while (i > 0 && !IS_DIR_SEPARATOR (canon_source_file[i]))
 290     i--;
 291
 292   if (i != 0)
 293     {
 294       source_path = (char *) alloca (i + 1);
 295       memcpy (source_path, canon_source_file, i);
 296       source_path[i] = 0;
 297       gfc_add_include_path (source_path, true, true, true);
 298     }
 299   else
 300     gfc_add_include_path (".", true, true, true);
 301
 302   if (canon_source_file != gfc_source_file)
 303     free (CONST_CAST (char *, canon_source_file));
 304
 305   /* Decide which form the file will be read in as.  */
 306
 307   if (gfc_option.source_form != FORM_UNKNOWN)
 308     gfc_current_form = gfc_option.source_form;
 309   else
 310     {
 311       gfc_current_form = form_from_filename (filename);
 312
 313       if (gfc_current_form == FORM_UNKNOWN)
 314         {
 315           gfc_current_form = FORM_FREE;
 316           main_input_filename = filename;
 317           gfc_warning_now (0, "Reading file %qs as free form",
 318                            (filename[0] == '\0') ? "<stdin>" : filename);
 319         }
 320     }
 321
 322   /* If the user specified -fd-lines-as-{code|comments} verify that we're
 323      in fixed form.  */
 324   if (gfc_current_form == FORM_FREE)
 325     {
 326       if (gfc_option.flag_d_lines == 0)
 327         gfc_warning_now (0, "%<-fd-lines-as-comments%> has no effect "
 328                            "in free form");
 329       else if (gfc_option.flag_d_lines == 1)
 330         gfc_warning_now (0, "%<-fd-lines-as-code%> has no effect in free form");
 331
 332       if (warn_line_truncation == -1)
 333           warn_line_truncation = 1;
 334
 335       /* Enable -Werror=line-truncation when -Werror and -Wno-error have
 336          not been set.  */
 337       if (warn_line_truncation && !global_options_set.x_warnings_are_errors
 338           && (global_dc->classify_diagnostic[OPT_Wline_truncation] ==
 339               DK_UNSPECIFIED))
 340         diagnostic_classify_diagnostic (global_dc, OPT_Wline_truncation,
 341                                         DK_ERROR, UNKNOWN_LOCATION);
 342     }
 343   else
 344     {
 345       /* With -fdec, set -fd-lines-as-comments by default in fixed form.  */
 346       if (flag_dec && gfc_option.flag_d_lines == -1)
 347         gfc_option.flag_d_lines = 0;
 348
 349       if (warn_line_truncation == -1)
 350         warn_line_truncation = 0;
 351     }
 352
 353   /* If -pedantic, warn about the use of GNU extensions.  */
 354   if (pedantic && (gfc_option.allow_std & GFC_STD_GNU) != 0)
 355     gfc_option.warn_std |= GFC_STD_GNU;
 356   /* -std=legacy -pedantic is effectively -std=gnu.  */
 357   if (pedantic && (gfc_option.allow_std & GFC_STD_LEGACY) != 0)
 358     gfc_option.warn_std |= GFC_STD_F95_OBS | GFC_STD_F95_DEL | GFC_STD_LEGACY;
 359
 360   /* If the user didn't explicitly specify -f(no)-second-underscore we
 361      use it if we're trying to be compatible with f2c, and not
 362      otherwise.  */
 363   if (flag_second_underscore == -1)
 364     flag_second_underscore = flag_f2c;
 365
 366   if (!flag_automatic && flag_max_stack_var_size != -2
 367       && flag_max_stack_var_size != 0)
 368     gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-fmax-stack-var-size=%d%>",
 369                      flag_max_stack_var_size);
 370   else if (!flag_automatic && flag_recursive)
 371     gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-frecursive%>");
 372   else if (!flag_automatic && flag_openmp)
 373     gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-frecursive%> implied by "
 374                      "%<-fopenmp%>");
 375   else if (flag_max_stack_var_size != -2 && flag_recursive)
 376     gfc_warning_now (0, "Flag %<-frecursive%> overwrites %<-fmax-stack-var-size=%d%>",
 377                      flag_max_stack_var_size);
 378   else if (flag_max_stack_var_size != -2 && flag_openmp)
 379     gfc_warning_now (0, "Flag %<-fmax-stack-var-size=%d%> overwrites %<-frecursive%> "
 380                      "implied by %<-fopenmp%>", flag_max_stack_var_size);
 381
 382   /* Implement -frecursive as -fmax-stack-var-size=-1.  */
 383   if (flag_recursive)
 384     flag_max_stack_var_size = -1;
 385
 386   /* Implied -frecursive; implemented as -fmax-stack-var-size=-1.  */
 387   if (flag_max_stack_var_size == -2 && flag_openmp && flag_automatic)
 388     {
 389       flag_recursive = 1;
 390       flag_max_stack_var_size = -1;
 391     }
 392
 393   /* Set flag_stack_arrays correctly.  */
 394   if (flag_stack_arrays == -1)
 395     flag_stack_arrays = 0;
 396
 397   /* Set default.  */
 398   if (flag_max_stack_var_size == -2)
 399     flag_max_stack_var_size = 32768;
 400
 401   /* Implement -fno-automatic as -fmax-stack-var-size=0.  */
 402   if (!flag_automatic)
 403     flag_max_stack_var_size = 0;
 404
 405   /* If the user did not specify an inline matmul limit, inline up to the BLAS
 406      limit or up to 30 if no external BLAS is specified.  */
 407
 408   if (flag_inline_matmul_limit < 0)
 409     {
 410       if (flag_external_blas)
 411         flag_inline_matmul_limit = flag_blas_matmul_limit;
 412       else
 413         flag_inline_matmul_limit = 30;
 414     }
 415
 416   /* Optimization implies front end optimization, unless the user
 417      specified it directly.  */
 418
 419   if (flag_frontend_optimize == -1)
 420     flag_frontend_optimize = optimize;
 421
 422   /* Same for front end loop interchange.  */
 423
 424   if (flag_frontend_loop_interchange == -1)
 425     flag_frontend_loop_interchange = optimize;
 426
 427   if (flag_max_array_constructor < 65535)
 428     flag_max_array_constructor = 65535;
 429
 430   if (flag_fixed_line_length != 0 && flag_fixed_line_length < 7)
 431     gfc_fatal_error ("Fixed line length must be at least seven");
 432
 433   if (flag_free_line_length != 0 && flag_free_line_length < 4)
 434     gfc_fatal_error ("Free line length must be at least three");
 435
 436   if (flag_max_subrecord_length > MAX_SUBRECORD_LENGTH)
 437     gfc_fatal_error ("Maximum subrecord length cannot exceed %d",
 438                      MAX_SUBRECORD_LENGTH);
 439
 440   gfc_cpp_post_options ();
 441
 442   if (gfc_option.allow_std & GFC_STD_F2008)
 443     lang_hooks.name = "GNU Fortran2008";
 444   else if (gfc_option.allow_std & GFC_STD_F2003)
 445     lang_hooks.name = "GNU Fortran2003";
 446
 447   return gfc_cpp_preprocess_only ();
 448 }
 449
 450
 451 static void
 452 gfc_handle_module_path_options (const char *arg)
 453 {
 454
 455   if (gfc_option.module_dir != NULL)
 456     gfc_fatal_error ("gfortran: Only one %<-J%> option allowed");
 457
 458   gfc_option.module_dir = XCNEWVEC (char, strlen (arg) + 2);
 459   strcpy (gfc_option.module_dir, arg);
 460
 461   gfc_add_include_path (gfc_option.module_dir, true, false, true);
 462
 463   strcat (gfc_option.module_dir, "/");
 464 }
 465
 466
 467 /* Handle options -ffpe-trap= and -ffpe-summary=.  */
 468
 469 static void
 470 gfc_handle_fpe_option (const char *arg, bool trap)
 471 {
 472   int result, pos = 0, n;
 473   /* precision is a backwards compatibility alias for inexact.  */
 474   static const char * const exception[] = { "invalid", "denormal", "zero",
 475                                             "overflow", "underflow",
 476                                             "inexact", "precision", NULL };
 477   static const int opt_exception[] = { GFC_FPE_INVALID, GFC_FPE_DENORMAL,
 478                                        GFC_FPE_ZERO, GFC_FPE_OVERFLOW,
 479                                        GFC_FPE_UNDERFLOW, GFC_FPE_INEXACT,
 480                                        GFC_FPE_INEXACT,
 481                                        0 };
 482
 483   /* As the default for -ffpe-summary= is nonzero, set it to 0.  */
 484   if (!trap)
 485     gfc_option.fpe_summary = 0;
 486
 487   while (*arg)
 488     {
 489       while (*arg == ',')
 490         arg++;
 491
 492       while (arg[pos] && arg[pos] != ',')
 493         pos++;
 494
 495       result = 0;
 496       if (!trap && strncmp ("none", arg, pos) == 0)
 497         {
 498           gfc_option.fpe_summary = 0;
 499           arg += pos;
 500           pos = 0;
 501           continue;
 502         }
 503       else if (!trap && strncmp ("all", arg, pos) == 0)
 504         {
 505           gfc_option.fpe_summary = GFC_FPE_INVALID | GFC_FPE_DENORMAL
 506                                    | GFC_FPE_ZERO | GFC_FPE_OVERFLOW
 507                                    | GFC_FPE_UNDERFLOW | GFC_FPE_INEXACT;
 508           arg += pos;
 509           pos = 0;
 510           continue;
 511         }
 512       else
 513         for (n = 0; exception[n] != NULL; n++)
 514           {
 515           if (exception[n] && strncmp (exception[n], arg, pos) == 0)
 516             {
 517               if (trap)
 518                 gfc_option.fpe |= opt_exception[n];
 519               else
 520                 gfc_option.fpe_summary |= opt_exception[n];
 521               arg += pos;
 522               pos = 0;
 523               result = 1;
 524               break;
 525             }
 526           }
 527       if (!result && !trap)
 528         gfc_fatal_error ("Argument to %<-ffpe-trap%> is not valid: %s", arg);
 529       else if (!result)
 530         gfc_fatal_error ("Argument to %<-ffpe-summary%> is not valid: %s", arg);
 531
 532     }
 533 }
 534
 535
 536 static void
 537 gfc_handle_runtime_check_option (const char *arg)
 538 {
 539   int result, pos = 0, n;
 540   static const char * const optname[] = { "all", "bounds", "array-temps",
 541                                           "recursion", "do", "pointer",
 542                                           "mem", NULL };
 543   static const int optmask[] = { GFC_RTCHECK_ALL, GFC_RTCHECK_BOUNDS,
 544                                  GFC_RTCHECK_ARRAY_TEMPS,
 545                                  GFC_RTCHECK_RECURSION, GFC_RTCHECK_DO,
 546                                  GFC_RTCHECK_POINTER, GFC_RTCHECK_MEM,
 547                                  0 };
 548
 549   while (*arg)
 550     {
 551       while (*arg == ',')
 552         arg++;
 553
 554       while (arg[pos] && arg[pos] != ',')
 555         pos++;
 556
 557       result = 0;
 558       for (n = 0; optname[n] != NULL; n++)
 559         {
 560           if (optname[n] && strncmp (optname[n], arg, pos) == 0)
 561             {
 562               gfc_option.rtcheck |= optmask[n];
 563               arg += pos;
 564               pos = 0;
 565               result = 1;
 566               break;
 567             }
 568           else if (optname[n] && pos > 3 && strncmp ("no-", arg, 3) == 0
 569                    && strncmp (optname[n], arg+3, pos-3) == 0)
 570             {
 571               gfc_option.rtcheck &= ~optmask[n];
 572               arg += pos;
 573               pos = 0;
 574               result = 1;
 575               break;
 576             }
 577         }
 578       if (!result)
 579         gfc_fatal_error ("Argument to %<-fcheck%> is not valid: %s", arg);
 580     }
 581 }
 582
 583
 584 /* Handle command-line options.  Returns 0 if unrecognized, 1 if
 585    recognized and handled.  */
 586
 587 bool
 588 gfc_handle_option (size_t scode, const char *arg, int value,
 589                    int kind ATTRIBUTE_UNUSED, location_t loc ATTRIBUTE_UNUSED,
 590                    const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 591 {
 592   bool result = true;
 593   enum opt_code code = (enum opt_code) scode;
 594
 595   if (gfc_cpp_handle_option (scode, arg, value) == 1)
 596     return true;
 597
 598   switch (code)
 599     {
 600     default:
 601       if (cl_options[code].flags & gfc_option_lang_mask ())
 602         break;
 603       result = false;
 604       break;
 605
 606     case OPT_fcheck_array_temporaries:
 607       gfc_option.rtcheck |= GFC_RTCHECK_ARRAY_TEMPS;
 608       break;
 609
 610     case OPT_fd_lines_as_code:
 611       gfc_option.flag_d_lines = 1;
 612       break;
 613
 614     case OPT_fd_lines_as_comments:
 615       gfc_option.flag_d_lines = 0;
 616       break;
 617
 618     case OPT_ffixed_form:
 619       gfc_option.source_form = FORM_FIXED;
 620       break;
 621
 622     case OPT_ffree_form:
 623       gfc_option.source_form = FORM_FREE;
 624       break;
 625
 626     case OPT_static_libgfortran:
 627 #ifndef HAVE_LD_STATIC_DYNAMIC
 628       gfc_fatal_error ("%<-static-libgfortran%> is not supported in this "
 629                        "configuration");
 630 #endif
 631       break;
 632
 633     case OPT_fintrinsic_modules_path:
 634     case OPT_fintrinsic_modules_path_:
 635
 636       /* This is needed because omp_lib.h is in a directory together
 637          with intrinsic modules.  Do no warn because during testing
 638          without an installed compiler, we would get lots of bogus
 639          warnings for a missing include directory.  */
 640       gfc_add_include_path (arg, false, false, false);
 641
 642       gfc_add_intrinsic_modules_path (arg);
 643       break;
 644
 645     case OPT_fpreprocessed:
 646       gfc_option.flag_preprocessed = value;
 647       break;
 648
 649     case OPT_fmax_identifier_length_:
 650       if (value > GFC_MAX_SYMBOL_LEN)
 651         gfc_fatal_error ("Maximum supported identifier length is %d",
 652                          GFC_MAX_SYMBOL_LEN);
 653       gfc_option.max_identifier_length = value;
 654       break;
 655
 656     case OPT_finit_local_zero:
 657       gfc_option.flag_init_integer = GFC_INIT_INTEGER_ON;
 658       gfc_option.flag_init_integer_value = 0;
 659       flag_init_real = GFC_INIT_REAL_ZERO;
 660       gfc_option.flag_init_logical = GFC_INIT_LOGICAL_FALSE;
 661       gfc_option.flag_init_character = GFC_INIT_CHARACTER_ON;
 662       gfc_option.flag_init_character_value = (char)0;
 663       break;
 664
 665     case OPT_finit_logical_:
 666       if (!strcasecmp (arg, "false"))
 667         gfc_option.flag_init_logical = GFC_INIT_LOGICAL_FALSE;
 668       else if (!strcasecmp (arg, "true"))
 669         gfc_option.flag_init_logical = GFC_INIT_LOGICAL_TRUE;
 670       else
 671         gfc_fatal_error ("Unrecognized option to %<-finit-logical%>: %s",
 672                          arg);
 673       break;
 674
 675     case OPT_finit_integer_:
 676       gfc_option.flag_init_integer = GFC_INIT_INTEGER_ON;
 677       gfc_option.flag_init_integer_value = atoi (arg);
 678       break;
 679
 680     case OPT_finit_character_:
 681       if (value >= 0 && value <= 127)
 682         {
 683           gfc_option.flag_init_character = GFC_INIT_CHARACTER_ON;
 684           gfc_option.flag_init_character_value = (char)value;
 685         }
 686       else
 687         gfc_fatal_error ("The value of n in %<-finit-character=n%> must be "
 688                          "between 0 and 127");
 689       break;
 690
 691     case OPT_I:
 692       gfc_add_include_path (arg, true, false, true);
 693       break;
 694
 695     case OPT_J:
 696       gfc_handle_module_path_options (arg);
 697       break;
 698
 699     case OPT_ffpe_trap_:
 700       gfc_handle_fpe_option (arg, true);
 701       break;
 702
 703     case OPT_ffpe_summary_:
 704       gfc_handle_fpe_option (arg, false);
 705       break;
 706
 707     case OPT_std_f95:
 708       gfc_option.allow_std = GFC_STD_OPT_F95;
 709       gfc_option.warn_std = GFC_STD_F95_OBS;
 710       gfc_option.max_continue_fixed = 19;
 711       gfc_option.max_continue_free = 39;
 712       gfc_option.max_identifier_length = 31;
 713       warn_ampersand = 1;
 714       warn_tabs = 1;
 715       break;
 716
 717     case OPT_std_f2003:
 718       gfc_option.allow_std = GFC_STD_OPT_F03;
 719       gfc_option.warn_std = GFC_STD_F95_OBS;
 720       gfc_option.max_identifier_length = 63;
 721       warn_ampersand = 1;
 722       warn_tabs = 1;
 723       break;
 724
 725     case OPT_std_f2008:
 726       gfc_option.allow_std = GFC_STD_OPT_F08;
 727       gfc_option.warn_std = GFC_STD_F95_OBS | GFC_STD_F2008_OBS;
 728       gfc_option.max_identifier_length = 63;
 729       warn_ampersand = 1;
 730       warn_tabs = 1;
 731       break;
 732
 733     case OPT_std_f2008ts:
 734     case OPT_std_f2018:
 735       gfc_option.allow_std = GFC_STD_OPT_F18;
 736       gfc_option.warn_std = GFC_STD_F95_OBS | GFC_STD_F2008_OBS
 737         | GFC_STD_F2018_OBS;
 738       gfc_option.max_identifier_length = 63;
 739       warn_ampersand = 1;
 740       warn_tabs = 1;
 741       break;
 742
 743     case OPT_std_gnu:
 744       set_default_std_flags ();
 745       break;
 746
 747     case OPT_std_legacy:
 748       set_default_std_flags ();
 749       gfc_option.warn_std = 0;
 750       break;
 751
 752     case OPT_fshort_enums:
 753       /* Handled in language-independent code.  */
 754       break;
 755
 756     case OPT_fcheck_:
 757       gfc_handle_runtime_check_option (arg);
 758       break;
 759
 760     case OPT_fdec:
 761       /* Enable all DEC extensions.  */
 762       set_dec_flags (1);
 763       break;
 764
 765     case OPT_fdec_structure:
 766       flag_dec_structure = 1;
 767       break;
 768     }
 769
 770   Fortran_handle_option_auto (&global_options, &global_options_set,
 771                               scode, arg, value,
 772                               gfc_option_lang_mask (), kind,
 773                               loc, handlers, global_dc);
 774   return result;
 775 }
 776
 777
 778 /* Return a string with the options passed to the compiler; used for
 779    Fortran's compiler_options() intrinsic.  */
 780
 781 char *
 782 gfc_get_option_string (void)
 783 {
 784   unsigned j;
 785   size_t len, pos;
 786   char *result;
 787
 788   /* Allocate and return a one-character string with '\0'.  */
 789   if (!save_decoded_options_count)
 790     return XCNEWVEC (char, 1);
 791
 792   /* Determine required string length.  */
 793
 794   len = 0;
 795   for (j = 1; j < save_decoded_options_count; j++)
 796     {
 797       switch (save_decoded_options[j].opt_index)
 798         {
 799         case OPT_o:
 800         case OPT_d:
 801         case OPT_dumpbase:
 802         case OPT_dumpdir:
 803         case OPT_auxbase:
 804         case OPT_quiet:
 805         case OPT_version:
 806         case OPT_fintrinsic_modules_path:
 807         case OPT_fintrinsic_modules_path_:
 808           /* Ignore these.  */
 809           break;
 810         default:
 811           /* Ignore file names.  */
 812           if (save_decoded_options[j].orig_option_with_args_text[0] == '-')
 813             len += 1
 814                  + strlen (save_decoded_options[j].orig_option_with_args_text);
 815         }
 816     }
 817
 818   result = XCNEWVEC (char, len);
 819
 820   pos = 0;
 821   for (j = 1; j < save_decoded_options_count; j++)
 822     {
 823       switch (save_decoded_options[j].opt_index)
 824         {
 825         case OPT_o:
 826         case OPT_d:
 827         case OPT_dumpbase:
 828         case OPT_dumpdir:
 829         case OPT_auxbase:
 830         case OPT_quiet:
 831         case OPT_version:
 832         case OPT_fintrinsic_modules_path:
 833         case OPT_fintrinsic_modules_path_:
 834           /* Ignore these.  */
 835           continue;
 836
 837         case OPT_cpp_:
 838           /* Use "-cpp" rather than "-cpp=<temporary file>".  */
 839           len = 4;
 840           break;
 841
 842         default:
 843           /* Ignore file names.  */
 844           if (save_decoded_options[j].orig_option_with_args_text[0] != '-')
 845             continue;
 846
 847           len = strlen (save_decoded_options[j].orig_option_with_args_text);
 848         }
 849
 850       memcpy (&result[pos], save_decoded_options[j].orig_option_with_args_text, len);
 851       pos += len;
 852       result[pos++] = ' ';
 853     }
 854
 855   result[--pos] = '\0';
 856   return result;
 857 }