libgfortran/io/open.c

   1 /* Copyright (C) 2002-2015 Free Software Foundation, Inc.
   2    Contributed by Andy Vaught
   3    F2003 I/O support contributed by Jerry DeLisle
   4
   5 This file is part of the GNU Fortran runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 Libgfortran is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "io.h"
  27 #include "fbuf.h"
  28 #include "unix.h"
  29
  30 #ifdef HAVE_UNISTD_H
  31 #include <unistd.h>
  32 #endif
  33
  34 #include <string.h>
  35 #include <errno.h>
  36 #include <stdlib.h>
  37
  38
  39 static const st_option access_opt[] = {
  40   {"sequential", ACCESS_SEQUENTIAL},
  41   {"direct", ACCESS_DIRECT},
  42   {"append", ACCESS_APPEND},
  43   {"stream", ACCESS_STREAM},
  44   {NULL, 0}
  45 };
  46
  47 static const st_option action_opt[] =
  48 {
  49   { "read", ACTION_READ},
  50   { "write", ACTION_WRITE},
  51   { "readwrite", ACTION_READWRITE},
  52   { NULL, 0}
  53 };
  54
  55 static const st_option blank_opt[] =
  56 {
  57   { "null", BLANK_NULL},
  58   { "zero", BLANK_ZERO},
  59   { NULL, 0}
  60 };
  61
  62 static const st_option delim_opt[] =
  63 {
  64   { "none", DELIM_NONE},
  65   { "apostrophe", DELIM_APOSTROPHE},
  66   { "quote", DELIM_QUOTE},
  67   { NULL, 0}
  68 };
  69
  70 static const st_option form_opt[] =
  71 {
  72   { "formatted", FORM_FORMATTED},
  73   { "unformatted", FORM_UNFORMATTED},
  74   { NULL, 0}
  75 };
  76
  77 static const st_option position_opt[] =
  78 {
  79   { "asis", POSITION_ASIS},
  80   { "rewind", POSITION_REWIND},
  81   { "append", POSITION_APPEND},
  82   { NULL, 0}
  83 };
  84
  85 static const st_option status_opt[] =
  86 {
  87   { "unknown", STATUS_UNKNOWN},
  88   { "old", STATUS_OLD},
  89   { "new", STATUS_NEW},
  90   { "replace", STATUS_REPLACE},
  91   { "scratch", STATUS_SCRATCH},
  92   { NULL, 0}
  93 };
  94
  95 static const st_option pad_opt[] =
  96 {
  97   { "yes", PAD_YES},
  98   { "no", PAD_NO},
  99   { NULL, 0}
 100 };
 101
 102 static const st_option decimal_opt[] =
 103 {
 104   { "point", DECIMAL_POINT},
 105   { "comma", DECIMAL_COMMA},
 106   { NULL, 0}
 107 };
 108
 109 static const st_option encoding_opt[] =
 110 {
 111   { "utf-8", ENCODING_UTF8},
 112   { "default", ENCODING_DEFAULT},
 113   { NULL, 0}
 114 };
 115
 116 static const st_option round_opt[] =
 117 {
 118   { "up", ROUND_UP},
 119   { "down", ROUND_DOWN},
 120   { "zero", ROUND_ZERO},
 121   { "nearest", ROUND_NEAREST},
 122   { "compatible", ROUND_COMPATIBLE},
 123   { "processor_defined", ROUND_PROCDEFINED},
 124   { NULL, 0}
 125 };
 126
 127 static const st_option sign_opt[] =
 128 {
 129   { "plus", SIGN_PLUS},
 130   { "suppress", SIGN_SUPPRESS},
 131   { "processor_defined", SIGN_PROCDEFINED},
 132   { NULL, 0}
 133 };
 134
 135 static const st_option convert_opt[] =
 136 {
 137   { "native", GFC_CONVERT_NATIVE},
 138   { "swap", GFC_CONVERT_SWAP},
 139   { "big_endian", GFC_CONVERT_BIG},
 140   { "little_endian", GFC_CONVERT_LITTLE},
 141   { NULL, 0}
 142 };
 143
 144 static const st_option async_opt[] =
 145 {
 146   { "yes", ASYNC_YES},
 147   { "no", ASYNC_NO},
 148   { NULL, 0}
 149 };
 150
 151 /* Given a unit, test to see if the file is positioned at the terminal
 152    point, and if so, change state from NO_ENDFILE flag to AT_ENDFILE.
 153    This prevents us from changing the state from AFTER_ENDFILE to
 154    AT_ENDFILE.  */
 155
 156 static void
 157 test_endfile (gfc_unit * u)
 158 {
 159   if (u->endfile == NO_ENDFILE)
 160     {
 161       gfc_offset sz = ssize (u->s);
 162       if (sz == 0 || sz == stell (u->s))
 163         u->endfile = AT_ENDFILE;
 164     }
 165 }
 166
 167
 168 /* Change the modes of a file, those that are allowed * to be
 169    changed.  */
 170
 171 static void
 172 edit_modes (st_parameter_open *opp, gfc_unit * u, unit_flags * flags)
 173 {
 174   /* Complain about attempts to change the unchangeable.  */
 175
 176   if (flags->status != STATUS_UNSPECIFIED && flags->status != STATUS_OLD &&
 177       u->flags.status != flags->status)
 178     generate_error (&opp->common, LIBERROR_BAD_OPTION,
 179                     "Cannot change STATUS parameter in OPEN statement");
 180
 181   if (flags->access != ACCESS_UNSPECIFIED && u->flags.access != flags->access)
 182     generate_error (&opp->common, LIBERROR_BAD_OPTION,
 183                     "Cannot change ACCESS parameter in OPEN statement");
 184
 185   if (flags->form != FORM_UNSPECIFIED && u->flags.form != flags->form)
 186     generate_error (&opp->common, LIBERROR_BAD_OPTION,
 187                     "Cannot change FORM parameter in OPEN statement");
 188
 189   if ((opp->common.flags & IOPARM_OPEN_HAS_RECL_IN)
 190       && opp->recl_in != u->recl)
 191     generate_error (&opp->common, LIBERROR_BAD_OPTION,
 192                     "Cannot change RECL parameter in OPEN statement");
 193
 194   if (flags->action != ACTION_UNSPECIFIED && u->flags.action != flags->action)
 195     generate_error (&opp->common, LIBERROR_BAD_OPTION,
 196                     "Cannot change ACTION parameter in OPEN statement");
 197
 198   /* Status must be OLD if present.  */
 199
 200   if (flags->status != STATUS_UNSPECIFIED && flags->status != STATUS_OLD &&
 201       flags->status != STATUS_UNKNOWN)
 202     {
 203       if (flags->status == STATUS_SCRATCH)
 204         notify_std (&opp->common, GFC_STD_GNU,
 205                     "OPEN statement must have a STATUS of OLD or UNKNOWN");
 206       else
 207         generate_error (&opp->common, LIBERROR_BAD_OPTION,
 208                     "OPEN statement must have a STATUS of OLD or UNKNOWN");
 209     }
 210
 211   if (u->flags.form == FORM_UNFORMATTED)
 212     {
 213       if (flags->delim != DELIM_UNSPECIFIED)
 214         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 215                         "DELIM parameter conflicts with UNFORMATTED form in "
 216                         "OPEN statement");
 217
 218       if (flags->blank != BLANK_UNSPECIFIED)
 219         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 220                         "BLANK parameter conflicts with UNFORMATTED form in "
 221                         "OPEN statement");
 222
 223       if (flags->pad != PAD_UNSPECIFIED)
 224         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 225                         "PAD parameter conflicts with UNFORMATTED form in "
 226                         "OPEN statement");
 227
 228       if (flags->decimal != DECIMAL_UNSPECIFIED)
 229         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 230                         "DECIMAL parameter conflicts with UNFORMATTED form in "
 231                         "OPEN statement");
 232
 233       if (flags->encoding != ENCODING_UNSPECIFIED)
 234         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 235                         "ENCODING parameter conflicts with UNFORMATTED form in "
 236                         "OPEN statement");
 237
 238       if (flags->round != ROUND_UNSPECIFIED)
 239         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 240                         "ROUND parameter conflicts with UNFORMATTED form in "
 241                         "OPEN statement");
 242
 243       if (flags->sign != SIGN_UNSPECIFIED)
 244         generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 245                         "SIGN parameter conflicts with UNFORMATTED form in "
 246                         "OPEN statement");
 247     }
 248
 249   if ((opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)
 250     {
 251       /* Change the changeable:  */
 252       if (flags->blank != BLANK_UNSPECIFIED)
 253         u->flags.blank = flags->blank;
 254       if (flags->delim != DELIM_UNSPECIFIED)
 255         u->flags.delim = flags->delim;
 256       if (flags->pad != PAD_UNSPECIFIED)
 257         u->flags.pad = flags->pad;
 258       if (flags->decimal != DECIMAL_UNSPECIFIED)
 259         u->flags.decimal = flags->decimal;
 260       if (flags->encoding != ENCODING_UNSPECIFIED)
 261         u->flags.encoding = flags->encoding;
 262       if (flags->async != ASYNC_UNSPECIFIED)
 263         u->flags.async = flags->async;
 264       if (flags->round != ROUND_UNSPECIFIED)
 265         u->flags.round = flags->round;
 266       if (flags->sign != SIGN_UNSPECIFIED)
 267         u->flags.sign = flags->sign;
 268
 269       /* Reposition the file if necessary.  */
 270
 271       switch (flags->position)
 272         {
 273         case POSITION_UNSPECIFIED:
 274         case POSITION_ASIS:
 275           break;
 276
 277         case POSITION_REWIND:
 278           if (sseek (u->s, 0, SEEK_SET) != 0)
 279             goto seek_error;
 280
 281           u->current_record = 0;
 282           u->last_record = 0;
 283
 284           test_endfile (u);
 285           break;
 286
 287         case POSITION_APPEND:
 288           if (sseek (u->s, 0, SEEK_END) < 0)
 289             goto seek_error;
 290
 291           if (flags->access != ACCESS_STREAM)
 292             u->current_record = 0;
 293
 294           u->endfile = AT_ENDFILE;      /* We are at the end.  */
 295           break;
 296
 297         seek_error:
 298           generate_error (&opp->common, LIBERROR_OS, NULL);
 299           break;
 300         }
 301     }
 302
 303   unlock_unit (u);
 304 }
 305
 306
 307 /* Open an unused unit.  */
 308
 309 gfc_unit *
 310 new_unit (st_parameter_open *opp, gfc_unit *u, unit_flags * flags)
 311 {
 312   gfc_unit *u2;
 313   stream *s;
 314   char tmpname[5 /* fort. */ + 10 /* digits of unit number */ + 1 /* 0 */];
 315
 316   /* Change unspecifieds to defaults.  Leave (flags->action ==
 317      ACTION_UNSPECIFIED) alone so open_external() can set it based on
 318      what type of open actually works.  */
 319
 320   if (flags->access == ACCESS_UNSPECIFIED)
 321     flags->access = ACCESS_SEQUENTIAL;
 322
 323   if (flags->form == FORM_UNSPECIFIED)
 324     flags->form = (flags->access == ACCESS_SEQUENTIAL)
 325       ? FORM_FORMATTED : FORM_UNFORMATTED;
 326
 327   if (flags->async == ASYNC_UNSPECIFIED)
 328     flags->async = ASYNC_NO;
 329
 330   if (flags->status == STATUS_UNSPECIFIED)
 331     flags->status = STATUS_UNKNOWN;
 332
 333   /* Checks.  */
 334
 335   if (flags->delim != DELIM_UNSPECIFIED
 336       && flags->form == FORM_UNFORMATTED)
 337     {
 338       generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 339                       "DELIM parameter conflicts with UNFORMATTED form in "
 340                       "OPEN statement");
 341       goto fail;
 342     }
 343
 344   if (flags->blank == BLANK_UNSPECIFIED)
 345     flags->blank = BLANK_NULL;
 346   else
 347     {
 348       if (flags->form == FORM_UNFORMATTED)
 349         {
 350           generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 351                           "BLANK parameter conflicts with UNFORMATTED form in "
 352                           "OPEN statement");
 353           goto fail;
 354         }
 355     }
 356
 357   if (flags->pad == PAD_UNSPECIFIED)
 358     flags->pad = PAD_YES;
 359   else
 360     {
 361       if (flags->form == FORM_UNFORMATTED)
 362         {
 363           generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 364                           "PAD parameter conflicts with UNFORMATTED form in "
 365                           "OPEN statement");
 366           goto fail;
 367         }
 368     }
 369
 370   if (flags->decimal == DECIMAL_UNSPECIFIED)
 371     flags->decimal = DECIMAL_POINT;
 372   else
 373     {
 374       if (flags->form == FORM_UNFORMATTED)
 375         {
 376           generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 377                           "DECIMAL parameter conflicts with UNFORMATTED form "
 378                           "in OPEN statement");
 379           goto fail;
 380         }
 381     }
 382
 383   if (flags->encoding == ENCODING_UNSPECIFIED)
 384     flags->encoding = ENCODING_DEFAULT;
 385   else
 386     {
 387       if (flags->form == FORM_UNFORMATTED)
 388         {
 389           generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 390                           "ENCODING parameter conflicts with UNFORMATTED form in "
 391                           "OPEN statement");
 392           goto fail;
 393         }
 394     }
 395
 396   /* NB: the value for ROUND when it's not specified by the user does not
 397          have to be PROCESSOR_DEFINED; the standard says that it is
 398          processor dependent, and requires that it is one of the
 399          possible value (see F2003, 9.4.5.13).  */
 400   if (flags->round == ROUND_UNSPECIFIED)
 401     flags->round = ROUND_PROCDEFINED;
 402   else
 403     {
 404       if (flags->form == FORM_UNFORMATTED)
 405         {
 406           generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 407                           "ROUND parameter conflicts with UNFORMATTED form in "
 408                           "OPEN statement");
 409           goto fail;
 410         }
 411     }
 412
 413   if (flags->sign == SIGN_UNSPECIFIED)
 414     flags->sign = SIGN_PROCDEFINED;
 415   else
 416     {
 417       if (flags->form == FORM_UNFORMATTED)
 418         {
 419           generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 420                           "SIGN parameter conflicts with UNFORMATTED form in "
 421                           "OPEN statement");
 422           goto fail;
 423         }
 424     }
 425
 426   if (flags->position != POSITION_ASIS && flags->access == ACCESS_DIRECT)
 427    {
 428      generate_error (&opp->common, LIBERROR_OPTION_CONFLICT,
 429                      "ACCESS parameter conflicts with SEQUENTIAL access in "
 430                      "OPEN statement");
 431      goto fail;
 432    }
 433   else
 434    if (flags->position == POSITION_UNSPECIFIED)
 435      flags->position = POSITION_ASIS;
 436
 437   if (flags->access == ACCESS_DIRECT
 438       && (opp->common.flags & IOPARM_OPEN_HAS_RECL_IN) == 0)
 439     {
 440       generate_error (&opp->common, LIBERROR_MISSING_OPTION,
 441                       "Missing RECL parameter in OPEN statement");
 442       goto fail;
 443     }
 444
 445   if ((opp->common.flags & IOPARM_OPEN_HAS_RECL_IN) && opp->recl_in <= 0)
 446     {
 447       generate_error (&opp->common, LIBERROR_BAD_OPTION,
 448                       "RECL parameter is non-positive in OPEN statement");
 449       goto fail;
 450     }
 451
 452   switch (flags->status)
 453     {
 454     case STATUS_SCRATCH:
 455       if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) == 0)
 456         {
 457           opp->file = NULL;
 458           break;
 459         }
 460
 461       generate_error (&opp->common, LIBERROR_BAD_OPTION,
 462                       "FILE parameter must not be present in OPEN statement");
 463       goto fail;
 464
 465     case STATUS_OLD:
 466     case STATUS_NEW:
 467     case STATUS_REPLACE:
 468     case STATUS_UNKNOWN:
 469       if ((opp->common.flags & IOPARM_OPEN_HAS_FILE))
 470         break;
 471
 472       opp->file = tmpname;
 473       opp->file_len = snprintf(opp->file, sizeof (tmpname), "fort.%d",
 474                                (int) opp->common.unit);
 475       break;
 476
 477     default:
 478       internal_error (&opp->common, "new_unit(): Bad status");
 479     }
 480
 481   /* Make sure the file isn't already open someplace else.
 482      Do not error if opening file preconnected to stdin, stdout, stderr.  */
 483
 484   u2 = NULL;
 485   if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) != 0)
 486     u2 = find_file (opp->file, opp->file_len);
 487   if (u2 != NULL
 488       && (options.stdin_unit < 0 || u2->unit_number != options.stdin_unit)
 489       && (options.stdout_unit < 0 || u2->unit_number != options.stdout_unit)
 490       && (options.stderr_unit < 0 || u2->unit_number != options.stderr_unit))
 491     {
 492       unlock_unit (u2);
 493       generate_error (&opp->common, LIBERROR_ALREADY_OPEN, NULL);
 494       goto cleanup;
 495     }
 496
 497   if (u2 != NULL)
 498     unlock_unit (u2);
 499
 500   /* Open file.  */
 501
 502   s = open_external (opp, flags);
 503   if (s == NULL)
 504     {
 505       char errbuf[256];
 506       char *path = fc_strdup (opp->file, opp->file_len);
 507       size_t msglen = opp->file_len + 22 + sizeof (errbuf);
 508       char *msg = xmalloc (msglen);
 509       snprintf (msg, msglen, "Cannot open file '%s': %s", path,
 510                 gf_strerror (errno, errbuf, sizeof (errbuf)));
 511       generate_error (&opp->common, LIBERROR_OS, msg);
 512       free (msg);
 513       free (path);
 514       goto cleanup;
 515     }
 516
 517   if (flags->status == STATUS_NEW || flags->status == STATUS_REPLACE)
 518     flags->status = STATUS_OLD;
 519
 520   /* Create the unit structure.  */
 521
 522   if (u->unit_number != opp->common.unit)
 523     internal_error (&opp->common, "Unit number changed");
 524   u->s = s;
 525   u->flags = *flags;
 526   u->read_bad = 0;
 527   u->endfile = NO_ENDFILE;
 528   u->last_record = 0;
 529   u->current_record = 0;
 530   u->mode = READING;
 531   u->maxrec = 0;
 532   u->bytes_left = 0;
 533   u->saved_pos = 0;
 534
 535   if (flags->position == POSITION_APPEND)
 536     {
 537       if (sseek (u->s, 0, SEEK_END) < 0)
 538         {
 539           generate_error (&opp->common, LIBERROR_OS, NULL);
 540           goto cleanup;
 541         }
 542       u->endfile = AT_ENDFILE;
 543     }
 544
 545   /* Unspecified recl ends up with a processor dependent value.  */
 546
 547   if ((opp->common.flags & IOPARM_OPEN_HAS_RECL_IN))
 548     {
 549       u->flags.has_recl = 1;
 550       u->recl = opp->recl_in;
 551       u->recl_subrecord = u->recl;
 552       u->bytes_left = u->recl;
 553     }
 554   else
 555     {
 556       u->flags.has_recl = 0;
 557       u->recl = max_offset;
 558       if (compile_options.max_subrecord_length)
 559         {
 560           u->recl_subrecord = compile_options.max_subrecord_length;
 561         }
 562       else
 563         {
 564           switch (compile_options.record_marker)
 565             {
 566             case 0:
 567               /* Fall through */
 568             case sizeof (GFC_INTEGER_4):
 569               u->recl_subrecord = GFC_MAX_SUBRECORD_LENGTH;
 570               break;
 571
 572             case sizeof (GFC_INTEGER_8):
 573               u->recl_subrecord = max_offset - 16;
 574               break;
 575
 576             default:
 577               runtime_error ("Illegal value for record marker");
 578               break;
 579             }
 580         }
 581     }
 582
 583   /* If the file is direct access, calculate the maximum record number
 584      via a division now instead of letting the multiplication overflow
 585      later.  */
 586
 587   if (flags->access == ACCESS_DIRECT)
 588     u->maxrec = max_offset / u->recl;
 589
 590   if (flags->access == ACCESS_STREAM)
 591     {
 592       u->maxrec = max_offset;
 593       u->recl = 1;
 594       u->bytes_left = 1;
 595       u->strm_pos = stell (u->s) + 1;
 596     }
 597
 598   u->filename = fc_strdup (opp->file, opp->file_len);
 599
 600   /* Curiously, the standard requires that the
 601      position specifier be ignored for new files so a newly connected
 602      file starts out at the initial point.  We still need to figure
 603      out if the file is at the end or not.  */
 604
 605   test_endfile (u);
 606
 607   if (flags->status == STATUS_SCRATCH && opp->file != NULL)
 608     free (opp->file);
 609
 610   if (flags->form == FORM_FORMATTED)
 611     {
 612       if ((opp->common.flags & IOPARM_OPEN_HAS_RECL_IN))
 613         fbuf_init (u, u->recl);
 614       else
 615         fbuf_init (u, 0);
 616     }
 617   else
 618     u->fbuf = NULL;
 619
 620
 621
 622   return u;
 623
 624  cleanup:
 625
 626   /* Free memory associated with a temporary filename.  */
 627
 628   if (flags->status == STATUS_SCRATCH && opp->file != NULL)
 629     free (opp->file);
 630
 631  fail:
 632
 633   close_unit (u);
 634   return NULL;
 635 }
 636
 637
 638 /* Open a unit which is already open.  This involves changing the
 639    modes or closing what is there now and opening the new file.  */
 640
 641 static void
 642 already_open (st_parameter_open *opp, gfc_unit * u, unit_flags * flags)
 643 {
 644   if ((opp->common.flags & IOPARM_OPEN_HAS_FILE) == 0)
 645     {
 646       edit_modes (opp, u, flags);
 647       return;
 648     }
 649
 650   /* If the file is connected to something else, close it and open a
 651      new unit.  */
 652
 653   if (!compare_file_filename (u, opp->file, opp->file_len))
 654     {
 655       if (sclose (u->s) == -1)
 656         {
 657           unlock_unit (u);
 658           generate_error (&opp->common, LIBERROR_OS,
 659                           "Error closing file in OPEN statement");
 660           return;
 661         }
 662
 663       u->s = NULL;
 664
 665 #if !HAVE_UNLINK_OPEN_FILE
 666       if (u->filename && u->flags.status == STATUS_SCRATCH)
 667         unlink (u->filename);
 668 #endif
 669      free (u->filename);
 670      u->filename = NULL;
 671
 672       u = new_unit (opp, u, flags);
 673       if (u != NULL)
 674         unlock_unit (u);
 675       return;
 676     }
 677
 678   edit_modes (opp, u, flags);
 679 }
 680
 681
 682 /* Open file.  */
 683
 684 extern void st_open (st_parameter_open *opp);
 685 export_proto(st_open);
 686
 687 void
 688 st_open (st_parameter_open *opp)
 689 {
 690   unit_flags flags;
 691   gfc_unit *u = NULL;
 692   GFC_INTEGER_4 cf = opp->common.flags;
 693   unit_convert conv;
 694
 695   library_start (&opp->common);
 696
 697   /* Decode options.  */
 698
 699   flags.access = !(cf & IOPARM_OPEN_HAS_ACCESS) ? ACCESS_UNSPECIFIED :
 700     find_option (&opp->common, opp->access, opp->access_len,
 701                  access_opt, "Bad ACCESS parameter in OPEN statement");
 702
 703   flags.action = !(cf & IOPARM_OPEN_HAS_ACTION) ? ACTION_UNSPECIFIED :
 704     find_option (&opp->common, opp->action, opp->action_len,
 705                  action_opt, "Bad ACTION parameter in OPEN statement");
 706
 707   flags.blank = !(cf & IOPARM_OPEN_HAS_BLANK) ? BLANK_UNSPECIFIED :
 708     find_option (&opp->common, opp->blank, opp->blank_len,
 709                  blank_opt, "Bad BLANK parameter in OPEN statement");
 710
 711   flags.delim = !(cf & IOPARM_OPEN_HAS_DELIM) ? DELIM_UNSPECIFIED :
 712     find_option (&opp->common, opp->delim, opp->delim_len,
 713                  delim_opt, "Bad DELIM parameter in OPEN statement");
 714
 715   flags.pad = !(cf & IOPARM_OPEN_HAS_PAD) ? PAD_UNSPECIFIED :
 716     find_option (&opp->common, opp->pad, opp->pad_len,
 717                  pad_opt, "Bad PAD parameter in OPEN statement");
 718
 719   flags.decimal = !(cf & IOPARM_OPEN_HAS_DECIMAL) ? DECIMAL_UNSPECIFIED :
 720     find_option (&opp->common, opp->decimal, opp->decimal_len,
 721                  decimal_opt, "Bad DECIMAL parameter in OPEN statement");
 722
 723   flags.encoding = !(cf & IOPARM_OPEN_HAS_ENCODING) ? ENCODING_UNSPECIFIED :
 724     find_option (&opp->common, opp->encoding, opp->encoding_len,
 725                  encoding_opt, "Bad ENCODING parameter in OPEN statement");
 726
 727   flags.async = !(cf & IOPARM_OPEN_HAS_ASYNCHRONOUS) ? ASYNC_UNSPECIFIED :
 728     find_option (&opp->common, opp->asynchronous, opp->asynchronous_len,
 729                  async_opt, "Bad ASYNCHRONOUS parameter in OPEN statement");
 730
 731   flags.round = !(cf & IOPARM_OPEN_HAS_ROUND) ? ROUND_UNSPECIFIED :
 732     find_option (&opp->common, opp->round, opp->round_len,
 733                  round_opt, "Bad ROUND parameter in OPEN statement");
 734
 735   flags.sign = !(cf & IOPARM_OPEN_HAS_SIGN) ? SIGN_UNSPECIFIED :
 736     find_option (&opp->common, opp->sign, opp->sign_len,
 737                  sign_opt, "Bad SIGN parameter in OPEN statement");
 738
 739   flags.form = !(cf & IOPARM_OPEN_HAS_FORM) ? FORM_UNSPECIFIED :
 740     find_option (&opp->common, opp->form, opp->form_len,
 741                  form_opt, "Bad FORM parameter in OPEN statement");
 742
 743   flags.position = !(cf & IOPARM_OPEN_HAS_POSITION) ? POSITION_UNSPECIFIED :
 744     find_option (&opp->common, opp->position, opp->position_len,
 745                  position_opt, "Bad POSITION parameter in OPEN statement");
 746
 747   flags.status = !(cf & IOPARM_OPEN_HAS_STATUS) ? STATUS_UNSPECIFIED :
 748     find_option (&opp->common, opp->status, opp->status_len,
 749                  status_opt, "Bad STATUS parameter in OPEN statement");
 750
 751   /* First, we check wether the convert flag has been set via environment
 752      variable.  This overrides the convert tag in the open statement.  */
 753
 754   conv = get_unformatted_convert (opp->common.unit);
 755
 756   if (conv == GFC_CONVERT_NONE)
 757     {
 758       /* Nothing has been set by environment variable, check the convert tag.  */
 759       if (cf & IOPARM_OPEN_HAS_CONVERT)
 760         conv = find_option (&opp->common, opp->convert, opp->convert_len,
 761                             convert_opt,
 762                             "Bad CONVERT parameter in OPEN statement");
 763       else
 764         conv = compile_options.convert;
 765     }
 766
 767   /* We use big_endian, which is 0 on little-endian machines
 768      and 1 on big-endian machines.  */
 769   switch (conv)
 770     {
 771     case GFC_CONVERT_NATIVE:
 772     case GFC_CONVERT_SWAP:
 773       break;
 774
 775     case GFC_CONVERT_BIG:
 776       conv = big_endian ? GFC_CONVERT_NATIVE : GFC_CONVERT_SWAP;
 777       break;
 778
 779     case GFC_CONVERT_LITTLE:
 780       conv = big_endian ? GFC_CONVERT_SWAP : GFC_CONVERT_NATIVE;
 781       break;
 782
 783     default:
 784       internal_error (&opp->common, "Illegal value for CONVERT");
 785       break;
 786     }
 787
 788   flags.convert = conv;
 789
 790   if (flags.position != POSITION_UNSPECIFIED
 791       && flags.access == ACCESS_DIRECT)
 792     generate_error (&opp->common, LIBERROR_BAD_OPTION,
 793                     "Cannot use POSITION with direct access files");
 794
 795   if (flags.access == ACCESS_APPEND)
 796     {
 797       if (flags.position != POSITION_UNSPECIFIED
 798           && flags.position != POSITION_APPEND)
 799         generate_error (&opp->common, LIBERROR_BAD_OPTION,
 800                         "Conflicting ACCESS and POSITION flags in"
 801                         " OPEN statement");
 802
 803       notify_std (&opp->common, GFC_STD_GNU,
 804                   "Extension: APPEND as a value for ACCESS in OPEN statement");
 805       flags.access = ACCESS_SEQUENTIAL;
 806       flags.position = POSITION_APPEND;
 807     }
 808
 809   if (flags.position == POSITION_UNSPECIFIED)
 810     flags.position = POSITION_ASIS;
 811
 812   if ((opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)
 813     {
 814       if ((opp->common.flags & IOPARM_OPEN_HAS_NEWUNIT))
 815         opp->common.unit = get_unique_unit_number(opp);
 816       else if (opp->common.unit < 0)
 817         {
 818           u = find_unit (opp->common.unit);
 819           if (u == NULL) /* Negative unit and no NEWUNIT-created unit found.  */
 820             {
 821               generate_error (&opp->common, LIBERROR_BAD_OPTION,
 822                               "Bad unit number in OPEN statement");
 823               library_end ();
 824               return;
 825             }
 826         }
 827
 828       if (u == NULL)
 829         u = find_or_create_unit (opp->common.unit);
 830       if (u->s == NULL)
 831         {
 832           u = new_unit (opp, u, &flags);
 833           if (u != NULL)
 834             unlock_unit (u);
 835         }
 836       else
 837         already_open (opp, u, &flags);
 838     }
 839
 840   if ((opp->common.flags & IOPARM_OPEN_HAS_NEWUNIT)
 841       && (opp->common.flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_OK)
 842     *opp->newunit = opp->common.unit;
 843
 844   library_end ();
 845 }