gcc/fortran/gfortranspec.c

   1 /* Specific flags and argument handling of the Fortran front-end.
   2    Copyright (C) 1997-2018 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* This file is copied more or less verbatim from g77.  */
  21 /* This file contains a filter for the main `gcc' driver, which is
  22    replicated for the `gfortran' driver by adding this filter.  The purpose
  23    of this filter is to be basically identical to gcc (in that
  24    it faithfully passes all of the original arguments to gcc) but,
  25    unless explicitly overridden by the user in certain ways, ensure
  26    that the needs of the language supported by this wrapper are met.
  27
  28    For GNU Fortran 95(gfortran), we do the following to the argument list
  29    before passing it to `gcc':
  30
  31    1.  Make sure `-lgfortran -lm' is at the end of the list.
  32
  33    2.  Make sure each time `-lgfortran' or `-lm' is seen, it forms
  34        part of the series `-lgfortran -lm'.
  35
  36    #1 and #2 are not done if `-nostdlib' or any option that disables
  37    the linking phase is present, or if `-xfoo' is in effect.  Note that
  38    a lack of source files or -l options disables linking.
  39
  40    This program was originally made out of gcc/cp/g++spec.c, but the
  41    way it builds the new argument list was rewritten so it is much
  42    easier to maintain, improve the way it decides to add or not add
  43    extra arguments, etc.  And several improvements were made in the
  44    handling of arguments, primarily to make it more consistent with
  45    `gcc' itself.  */
  46
  47 #include "config.h"
  48 #include "system.h"
  49 #include "coretypes.h"
  50 #include "opt-suggestions.h"
  51 #include "gcc.h"
  52 #include "opts.h"
  53
  54 #include "tm.h"
  55 #include "intl.h"
  56
  57 #ifndef MATH_LIBRARY
  58 #define MATH_LIBRARY "m"
  59 #endif
  60
  61 #ifndef FORTRAN_LIBRARY
  62 #define FORTRAN_LIBRARY "gfortran"
  63 #endif
  64
  65 /* Name of the spec file.  */
  66 #define SPEC_FILE "libgfortran.spec"
  67
  68 /* The original argument list and related info is copied here.  */
  69 static unsigned int g77_xargc;
  70 static const struct cl_decoded_option *g77_x_decoded_options;
  71 static void append_arg (const struct cl_decoded_option *);
  72
  73 /* The new argument list will be built here.  */
  74 static unsigned int g77_newargc;
  75 static struct cl_decoded_option *g77_new_decoded_options;
  76
  77 /* This will be NULL if we encounter a situation where we should not
  78    link in the fortran libraries.  */
  79 static const char *library = NULL;
  80
  81
  82 /* Return whether strings S1 and S2 are both NULL or both the same
  83    string.  */
  84
  85 static bool
  86 strings_same (const char *s1, const char *s2)
  87 {
  88   return s1 == s2 || (s1 != NULL && s2 != NULL && strcmp (s1, s2) == 0);
  89 }
  90
  91 /* Return whether decoded option structures OPT1 and OPT2 are the
  92    same.  */
  93
  94 static bool
  95 options_same (const struct cl_decoded_option *opt1,
  96               const struct cl_decoded_option *opt2)
  97 {
  98   return (opt1->opt_index == opt2->opt_index
  99           && strings_same (opt1->arg, opt2->arg)
 100           && strings_same (opt1->orig_option_with_args_text,
 101                            opt2->orig_option_with_args_text)
 102           && strings_same (opt1->canonical_option[0],
 103                            opt2->canonical_option[0])
 104           && strings_same (opt1->canonical_option[1],
 105                            opt2->canonical_option[1])
 106           && strings_same (opt1->canonical_option[2],
 107                            opt2->canonical_option[2])
 108           && strings_same (opt1->canonical_option[3],
 109                            opt2->canonical_option[3])
 110           && (opt1->canonical_option_num_elements
 111               == opt2->canonical_option_num_elements)
 112           && opt1->value == opt2->value
 113           && opt1->errors == opt2->errors);
 114 }
 115
 116 /* Append another argument to the list being built.  As long as it is
 117    identical to the corresponding arg in the original list, just increment
 118    the new arg count.  Otherwise allocate a new list, etc.  */
 119
 120 static void
 121 append_arg (const struct cl_decoded_option *arg)
 122 {
 123   static unsigned int newargsize;
 124
 125   if (g77_new_decoded_options == g77_x_decoded_options
 126       && g77_newargc < g77_xargc
 127       && options_same (arg, &g77_x_decoded_options[g77_newargc]))
 128     {
 129       ++g77_newargc;
 130       return;                   /* Nothing new here.  */
 131     }
 132
 133   if (g77_new_decoded_options == g77_x_decoded_options)
 134     {                           /* Make new arglist.  */
 135       unsigned int i;
 136
 137       newargsize = (g77_xargc << 2) + 20;       /* This should handle all.  */
 138       g77_new_decoded_options = XNEWVEC (struct cl_decoded_option, newargsize);
 139
 140       /* Copy what has been done so far.  */
 141       for (i = 0; i < g77_newargc; ++i)
 142         g77_new_decoded_options[i] = g77_x_decoded_options[i];
 143     }
 144
 145   if (g77_newargc == newargsize)
 146     fatal_error (input_location, "overflowed output arg list for %qs",
 147                  arg->orig_option_with_args_text);
 148
 149   g77_new_decoded_options[g77_newargc++] = *arg;
 150 }
 151
 152 /* Append an option described by OPT_INDEX, ARG and VALUE to the list
 153    being built.  */
 154 static void
 155 append_option (size_t opt_index, const char *arg, int value)
 156 {
 157   struct cl_decoded_option decoded;
 158
 159   generate_option (opt_index, arg, value, CL_DRIVER, &decoded);
 160   append_arg (&decoded);
 161 }
 162
 163 /* Append a libgfortran argument to the list being built.  If
 164    FORCE_STATIC, ensure the library is linked statically.  */
 165
 166 static void
 167 add_arg_libgfortran (bool force_static ATTRIBUTE_UNUSED)
 168 {
 169 #ifdef HAVE_LD_STATIC_DYNAMIC
 170   if (force_static)
 171     append_option (OPT_Wl_, LD_STATIC_OPTION, 1);
 172 #endif
 173   append_option (OPT_l, FORTRAN_LIBRARY, 1);
 174 #ifdef HAVE_LD_STATIC_DYNAMIC
 175   if (force_static)
 176     append_option (OPT_Wl_, LD_DYNAMIC_OPTION, 1);
 177 #endif
 178 }
 179
 180 void
 181 lang_specific_driver (struct cl_decoded_option **in_decoded_options,
 182                       unsigned int *in_decoded_options_count,
 183                       int *in_added_libraries ATTRIBUTE_UNUSED)
 184 {
 185   unsigned int argc = *in_decoded_options_count;
 186   struct cl_decoded_option *decoded_options = *in_decoded_options;
 187   unsigned int i;
 188   int verbose = 0;
 189
 190   /* 0 => -xnone in effect.
 191      1 => -xfoo in effect.  */
 192   int saw_speclang = 0;
 193
 194   /* 0 => initial/reset state
 195      1 => last arg was -l<library>
 196      2 => last two args were -l<library> -lm.  */
 197   int saw_library = 0;
 198
 199   /* By default, we throw on the math library if we have one.  */
 200   int need_math = (MATH_LIBRARY[0] != '\0');
 201
 202   /* Whether we should link a static libgfortran.  */
 203   int static_lib = 0;
 204
 205   /* Whether we need to link statically.  */
 206   int static_linking = 0;
 207
 208   /* The number of input and output files in the incoming arg list.  */
 209   int n_infiles = 0;
 210   int n_outfiles = 0;
 211
 212   library = FORTRAN_LIBRARY;
 213
 214 #if 0
 215   fprintf (stderr, "Incoming:");
 216   for (i = 0; i < argc; i++)
 217     fprintf (stderr, " %s", decoded_options[i].orig_option_with_args_text);
 218   fprintf (stderr, "\n");
 219 #endif
 220
 221   g77_xargc = argc;
 222   g77_x_decoded_options = decoded_options;
 223   g77_newargc = 0;
 224   g77_new_decoded_options = decoded_options;
 225
 226   /* First pass through arglist.
 227
 228      If -nostdlib or a "turn-off-linking" option is anywhere in the
 229      command line, don't do any library-option processing (except
 230      relating to -x).  */
 231
 232   for (i = 1; i < argc; ++i)
 233     {
 234       if (decoded_options[i].errors & CL_ERR_MISSING_ARG)
 235         continue;
 236
 237       switch (decoded_options[i].opt_index)
 238         {
 239         case OPT_SPECIAL_input_file:
 240           ++n_infiles;
 241           continue;
 242
 243         case OPT_nostdlib:
 244         case OPT_nodefaultlibs:
 245         case OPT_c:
 246         case OPT_S:
 247         case OPT_fsyntax_only:
 248         case OPT_E:
 249           /* These options disable linking entirely or linking of the
 250              standard libraries.  */
 251           library = 0;
 252           break;
 253
 254         case OPT_static_libgfortran:
 255 #ifdef HAVE_LD_STATIC_DYNAMIC
 256           static_lib = 1;
 257 #endif
 258           break;
 259
 260         case OPT_static:
 261 #ifdef HAVE_LD_STATIC_DYNAMIC
 262           static_linking = 1;
 263 #endif
 264           break;
 265
 266         case OPT_l:
 267           ++n_infiles;
 268           break;
 269
 270         case OPT_o:
 271           ++n_outfiles;
 272           break;
 273
 274         case OPT_v:
 275           verbose = 1;
 276           break;
 277
 278         case OPT__version:
 279           printf ("GNU Fortran %s%s\n", pkgversion_string, version_string);
 280           printf ("Copyright %s 2018 Free Software Foundation, Inc.\n",
 281                   _("(C)"));
 282           fputs (_("This is free software; see the source for copying conditions.  There is NO\n\
 283 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n"),
 284                 stdout);
 285           exit (0);
 286           break;
 287
 288         case OPT__help:
 289           /* Let gcc.c handle this, as it has a really
 290              cool facility for handling --help and --verbose --help.  */
 291           return;
 292
 293         default:
 294           break;
 295         }
 296     }
 297
 298   if ((n_outfiles != 0) && (n_infiles == 0))
 299     fatal_error (input_location,
 300                  "no input files; unwilling to write output files");
 301
 302   /* If there are no input files, no need for the library.  */
 303   if (n_infiles == 0)
 304     library = 0;
 305
 306   /* Second pass through arglist, transforming arguments as appropriate.  */
 307
 308   append_arg (&decoded_options[0]); /* Start with command name, of course.  */
 309
 310   for (i = 1; i < argc; ++i)
 311     {
 312       if (decoded_options[i].errors & CL_ERR_MISSING_ARG)
 313         {
 314           append_arg (&decoded_options[i]);
 315           continue;
 316         }
 317
 318       if (decoded_options[i].opt_index == OPT_SPECIAL_input_file
 319           && decoded_options[i].arg[0] == '\0')
 320         {
 321           /* Interesting.  Just append as is.  */
 322           append_arg (&decoded_options[i]);
 323           continue;
 324         }
 325
 326       if (decoded_options[i].opt_index != OPT_l
 327           && (decoded_options[i].opt_index != OPT_SPECIAL_input_file
 328               || strcmp (decoded_options[i].arg, "-") == 0))
 329         {
 330           /* Not a filename or library.  */
 331
 332           if (saw_library == 1 && need_math)    /* -l<library>.  */
 333             append_option (OPT_l, MATH_LIBRARY, 1);
 334
 335           saw_library = 0;
 336
 337           if (decoded_options[i].opt_index == OPT_SPECIAL_input_file)
 338             {
 339               append_arg (&decoded_options[i]); /* "-" == Standard input.  */
 340               continue;
 341             }
 342
 343           if (decoded_options[i].opt_index == OPT_x)
 344             {
 345               /* Track input language.  */
 346               const char *lang = decoded_options[i].arg;
 347
 348               saw_speclang = (strcmp (lang, "none") != 0);
 349             }
 350
 351           append_arg (&decoded_options[i]);
 352
 353           continue;
 354         }
 355
 356       /* A filename/library, not an option.  */
 357
 358       if (saw_speclang)
 359         saw_library = 0;        /* -xfoo currently active.  */
 360       else
 361         {                       /* -lfoo or filename.  */
 362           if (decoded_options[i].opt_index == OPT_l
 363               && strcmp (decoded_options[i].arg, MATH_LIBRARY) == 0)
 364             {
 365               if (saw_library == 1)
 366                 saw_library = 2;        /* -l<library> -lm.  */
 367               else
 368                 add_arg_libgfortran (static_lib && !static_linking);
 369             }
 370           else if (decoded_options[i].opt_index == OPT_l
 371               && strcmp (decoded_options[i].arg, FORTRAN_LIBRARY) == 0)
 372             {
 373               saw_library = 1;  /* -l<library>.  */
 374               add_arg_libgfortran (static_lib && !static_linking);
 375               continue;
 376             }
 377           else
 378             {                   /* Other library, or filename.  */
 379               if (saw_library == 1 && need_math)
 380                 append_option (OPT_l, MATH_LIBRARY, 1);
 381               saw_library = 0;
 382             }
 383         }
 384       append_arg (&decoded_options[i]);
 385     }
 386
 387   /* Append `-lgfortran -lm' as necessary.  */
 388
 389   if (library)
 390     {                           /* Doing a link and no -nostdlib.  */
 391       if (saw_speclang)
 392         append_option (OPT_x, "none", 1);
 393
 394       switch (saw_library)
 395         {
 396         case 0:
 397           add_arg_libgfortran (static_lib && !static_linking);
 398           /* Fall through.  */
 399
 400         case 1:
 401           if (need_math)
 402             append_option (OPT_l, MATH_LIBRARY, 1);
 403         default:
 404           break;
 405         }
 406     }
 407
 408 #ifdef ENABLE_SHARED_LIBGCC
 409   if (library)
 410     {
 411       unsigned int i;
 412
 413       for (i = 1; i < g77_newargc; i++)
 414         if (g77_new_decoded_options[i].opt_index == OPT_static_libgcc
 415             || g77_new_decoded_options[i].opt_index == OPT_static)
 416           break;
 417
 418       if (i == g77_newargc)
 419         append_option (OPT_shared_libgcc, NULL, 1);
 420     }
 421
 422 #endif
 423
 424   if (verbose && g77_new_decoded_options != g77_x_decoded_options)
 425     {
 426       fprintf (stderr, _("Driving:"));
 427       for (i = 0; i < g77_newargc; i++)
 428         fprintf (stderr, " %s",
 429                  g77_new_decoded_options[i].orig_option_with_args_text);
 430       fprintf (stderr, "\n");
 431     }
 432
 433   *in_decoded_options_count = g77_newargc;
 434   *in_decoded_options = g77_new_decoded_options;
 435 }
 436
 437
 438 /* Called before linking.  Returns 0 on success and -1 on failure.  */
 439 int
 440 lang_specific_pre_link (void)
 441 {
 442   if (library)
 443     do_spec ("%:include(libgfortran.spec)");
 444
 445   return 0;
 446 }
 447
 448 /* Number of extra output files that lang_specific_pre_link may generate.  */
 449 int lang_specific_extra_outfiles = 0;   /* Not used for F77.  */