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  40    This program was originally made out of gcc/cp/g++spec.c, but the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