libgfortran/runtime/error.c

   1 /* Copyright (C) 2002-2018 Free Software Foundation, Inc.
   2    Contributed by Andy Vaught
   3
   4 This file is part of the GNU Fortran runtime library (libgfortran).
   5
   6 Libgfortran 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 Libgfortran 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 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25
  26 #include "libgfortran.h"
  27 #include "io.h"
  28 #include "async.h"
  29
  30 #include <assert.h>
  31 #include <string.h>
  32 #include <errno.h>
  33 #include <signal.h>
  34
  35 #ifdef HAVE_UNISTD_H
  36 #include <unistd.h>
  37 #endif
  38
  39 #ifdef HAVE_SYS_TIME_H
  40 #include <sys/time.h>
  41 #endif
  42
  43 /* <sys/time.h> has to be included before <sys/resource.h> to work
  44    around PR 30518; otherwise, MacOS 10.3.9 headers are just broken.  */
  45 #ifdef HAVE_SYS_RESOURCE_H
  46 #include <sys/resource.h>
  47 #endif
  48
  49
  50 #include <locale.h>
  51
  52 #ifdef HAVE_XLOCALE_H
  53 #include <xlocale.h>
  54 #endif
  55
  56
  57 #ifdef __MINGW32__
  58 #define HAVE_GETPID 1
  59 #include <process.h>
  60 #endif
  61
  62
  63 /* Termination of a program: F2008 2.3.5 talks about "normal
  64    termination" and "error termination". Normal termination occurs as
  65    a result of e.g. executing the end program statement, and executing
  66    the STOP statement. It includes the effect of the C exit()
  67    function.
  68
  69    Error termination is initiated when the ERROR STOP statement is
  70    executed, when ALLOCATE/DEALLOCATE fails without STAT= being
  71    specified, when some of the co-array synchronization statements
  72    fail without STAT= being specified, and some I/O errors if
  73    ERR/IOSTAT/END/EOR is not present, and finally EXECUTE_COMMAND_LINE
  74    failure without CMDSTAT=.
  75
  76    2.3.5 also explains how co-images synchronize during termination.
  77
  78    In libgfortran we have three ways of ending a program. exit(code)
  79    is a normal exit; calling exit() also causes open units to be
  80    closed. No backtrace or core dump is needed here.  For error
  81    termination, we have exit_error(status), which prints a backtrace
  82    if backtracing is enabled, then exits.  Finally, when something
  83    goes terribly wrong, we have sys_abort() which tries to print the
  84    backtrace if -fbacktrace is enabled, and then dumps core; whether a
  85    core file is generated is system dependent. When aborting, we don't
  86    flush and close open units, as program memory might be corrupted
  87    and we'd rather risk losing dirty data in the buffers rather than
  88    corrupting files on disk.
  89
  90 */
  91
  92 /* Error conditions.  The tricky part here is printing a message when
  93  * it is the I/O subsystem that is severely wounded.  Our goal is to
  94  * try and print something making the fewest assumptions possible,
  95  * then try to clean up before actually exiting.
  96  *
  97  * The following exit conditions are defined:
  98  * 0    Normal program exit.
  99  * 1    Terminated because of operating system error.
 100  * 2    Error in the runtime library
 101  * 3    Internal error in runtime library
 102  *
 103  * Other error returns are reserved for the STOP statement with a numeric code.
 104  */
 105
 106
 107 /* Write a null-terminated C string to standard error. This function
 108    is async-signal-safe.  */
 109
 110 ssize_t
 111 estr_write (const char *str)
 112 {
 113   return write (STDERR_FILENO, str, strlen (str));
 114 }
 115
 116
 117 /* Write a vector of strings to standard error.  This function is
 118    async-signal-safe.  */
 119
 120 ssize_t
 121 estr_writev (const struct iovec *iov, int iovcnt)
 122 {
 123 #ifdef HAVE_WRITEV
 124   return writev (STDERR_FILENO, iov, iovcnt);
 125 #else
 126   ssize_t w = 0;
 127   for (int i = 0; i < iovcnt; i++)
 128     {
 129       ssize_t r = write (STDERR_FILENO, iov[i].iov_base, iov[i].iov_len);
 130       if (r == -1)
 131         return r;
 132       w += r;
 133     }
 134   return w;
 135 #endif
 136 }
 137
 138
 139 #ifndef HAVE_VSNPRINTF
 140 static int
 141 gf_vsnprintf (char *str, size_t size, const char *format, va_list ap)
 142 {
 143   int written;
 144
 145   written = vsprintf(buffer, format, ap);
 146
 147   if (written >= size - 1)
 148     {
 149       /* The error message was longer than our buffer.  Ouch.  Because
 150          we may have messed up things badly, report the error and
 151          quit.  */
 152 #define ERROR_MESSAGE "Internal error: buffer overrun in gf_vsnprintf()\n"
 153       write (STDERR_FILENO, buffer, size - 1);
 154       write (STDERR_FILENO, ERROR_MESSAGE, strlen (ERROR_MESSAGE));
 155       sys_abort ();
 156 #undef ERROR_MESSAGE
 157
 158     }
 159   return written;
 160 }
 161
 162 #define vsnprintf gf_vsnprintf
 163 #endif
 164
 165
 166 /* printf() like function for for printing to stderr.  Uses a stack
 167    allocated buffer and doesn't lock stderr, so it should be safe to
 168    use from within a signal handler.  */
 169
 170 #define ST_ERRBUF_SIZE 512
 171
 172 int
 173 st_printf (const char * format, ...)
 174 {
 175   char buffer[ST_ERRBUF_SIZE];
 176   int written;
 177   va_list ap;
 178   va_start (ap, format);
 179   written = vsnprintf (buffer, ST_ERRBUF_SIZE, format, ap);
 180   va_end (ap);
 181   written = write (STDERR_FILENO, buffer, written);
 182   return written;
 183 }
 184
 185
 186 /* sys_abort()-- Terminate the program showing backtrace and dumping
 187    core.  */
 188
 189 void
 190 sys_abort (void)
 191 {
 192   /* If backtracing is enabled, print backtrace and disable signal
 193      handler for ABRT.  */
 194   if (options.backtrace == 1
 195       || (options.backtrace == -1 && compile_options.backtrace == 1))
 196     {
 197       estr_write ("\nProgram aborted. Backtrace:\n");
 198       show_backtrace (false);
 199       signal (SIGABRT, SIG_DFL);
 200     }
 201
 202   abort();
 203 }
 204
 205
 206 /* Exit in case of error termination. If backtracing is enabled, print
 207    backtrace, then exit.  */
 208
 209 void
 210 exit_error (int status)
 211 {
 212   if (options.backtrace == 1
 213       || (options.backtrace == -1 && compile_options.backtrace == 1))
 214     {
 215       estr_write ("\nError termination. Backtrace:\n");
 216       show_backtrace (false);
 217     }
 218   exit (status);
 219 }
 220
 221
 222
 223 /* gfc_xtoa()-- Integer to hexadecimal conversion.  */
 224
 225 const char *
 226 gfc_xtoa (GFC_UINTEGER_LARGEST n, char *buffer, size_t len)
 227 {
 228   int digit;
 229   char *p;
 230
 231   assert (len >= GFC_XTOA_BUF_SIZE);
 232
 233   if (n == 0)
 234     return "0";
 235
 236   p = buffer + GFC_XTOA_BUF_SIZE - 1;
 237   *p = '\0';
 238
 239   while (n != 0)
 240     {
 241       digit = n & 0xF;
 242       if (digit > 9)
 243         digit += 'A' - '0' - 10;
 244
 245       *--p = '0' + digit;
 246       n >>= 4;
 247     }
 248
 249   return p;
 250 }
 251
 252
 253 /* Hopefully thread-safe wrapper for a strerror() style function.  */
 254
 255 char *
 256 gf_strerror (int errnum,
 257              char * buf __attribute__((unused)),
 258              size_t buflen __attribute__((unused)))
 259 {
 260 #ifdef HAVE_STRERROR_L
 261   locale_t myloc = newlocale (LC_CTYPE_MASK | LC_MESSAGES_MASK, "",
 262                               (locale_t) 0);
 263   char *p;
 264   if (myloc)
 265     {
 266       p = strerror_l (errnum, myloc);
 267       freelocale (myloc);
 268     }
 269   else
 270     /* newlocale might fail e.g. due to running out of memory, fall
 271        back to the simpler strerror.  */
 272     p = strerror (errnum);
 273   return p;
 274 #elif defined(HAVE_STRERROR_R)
 275 #ifdef HAVE_USELOCALE
 276   /* Some targets (Darwin at least) have the POSIX 2008 extended
 277      locale functions, but not strerror_l.  So reset the per-thread
 278      locale here.  */
 279   uselocale (LC_GLOBAL_LOCALE);
 280 #endif
 281   /* POSIX returns an "int", GNU a "char*".  */
 282   return
 283     __builtin_choose_expr (__builtin_classify_type (strerror_r (0, buf, 0))
 284                            == 5,
 285                            /* GNU strerror_r()  */
 286                            strerror_r (errnum, buf, buflen),
 287                            /* POSIX strerror_r ()  */
 288                            (strerror_r (errnum, buf, buflen), buf));
 289 #elif defined(HAVE_STRERROR_R_2ARGS)
 290   strerror_r (errnum, buf);
 291   return buf;
 292 #else
 293   /* strerror () is not necessarily thread-safe, but should at least
 294      be available everywhere.  */
 295   return strerror (errnum);
 296 #endif
 297 }
 298
 299
 300 /* show_locus()-- Print a line number and filename describing where
 301  * something went wrong */
 302
 303 void
 304 show_locus (st_parameter_common *cmp)
 305 {
 306   char *filename;
 307
 308   if (!options.locus || cmp == NULL || cmp->filename == NULL)
 309     return;
 310
 311   if (cmp->unit > 0)
 312     {
 313       filename = filename_from_unit (cmp->unit);
 314
 315       if (filename != NULL)
 316         {
 317           st_printf ("At line %d of file %s (unit = %d, file = '%s')\n",
 318                    (int) cmp->line, cmp->filename, (int) cmp->unit, filename);
 319           free (filename);
 320         }
 321       else
 322         {
 323           st_printf ("At line %d of file %s (unit = %d)\n",
 324                    (int) cmp->line, cmp->filename, (int) cmp->unit);
 325         }
 326       return;
 327     }
 328
 329   st_printf ("At line %d of file %s\n", (int) cmp->line, cmp->filename);
 330 }
 331
 332
 333 /* recursion_check()-- It's possible for additional errors to occur
 334  * during fatal error processing.  We detect this condition here and
 335  * abort immediately. */
 336
 337 static __gthread_key_t recursion_key;
 338
 339 static void
 340 recursion_check (void)
 341 {
 342   if (__gthread_active_p ())
 343     {
 344       bool* p = __gthread_getspecific (recursion_key);
 345       if (!p)
 346         {
 347           p = xcalloc (1, sizeof (bool));
 348           __gthread_setspecific (recursion_key, p);
 349         }
 350       if (*p)
 351         sys_abort ();
 352       *p = true;
 353     }
 354   else
 355     {
 356       static bool recur;
 357       if (recur)
 358         sys_abort ();
 359       recur = true;
 360     }
 361 }
 362
 363 #ifdef __GTHREADS
 364 static void __attribute__((constructor))
 365 constructor_recursion_check (void)
 366 {
 367   if (__gthread_active_p ())
 368     __gthread_key_create (&recursion_key, &free);
 369 }
 370
 371 static void __attribute__((destructor))
 372 destructor_recursion_check (void)
 373 {
 374   if (__gthread_active_p ())
 375     __gthread_key_delete (recursion_key);
 376 }
 377 #endif
 378
 379
 380
 381 #define STRERR_MAXSZ 256
 382
 383 /* os_error()-- Operating system error.  We get a message from the
 384  * operating system, show it and leave.  Some operating system errors
 385  * are caught and processed by the library.  If not, we come here. */
 386
 387 void
 388 os_error (const char *message)
 389 {
 390   char errmsg[STRERR_MAXSZ];
 391   struct iovec iov[5];
 392   recursion_check ();
 393   iov[0].iov_base = (char*) "Operating system error: ";
 394   iov[0].iov_len = strlen (iov[0].iov_base);
 395   iov[1].iov_base = gf_strerror (errno, errmsg, STRERR_MAXSZ);
 396   iov[1].iov_len = strlen (iov[1].iov_base);
 397   iov[2].iov_base = (char*) "\n";
 398   iov[2].iov_len = 1;
 399   iov[3].iov_base = (char*) message;
 400   iov[3].iov_len = strlen (message);
 401   iov[4].iov_base = (char*) "\n";
 402   iov[4].iov_len = 1;
 403   estr_writev (iov, 5);
 404   exit_error (1);
 405 }
 406 iexport(os_error);
 407
 408
 409 /* void runtime_error()-- These are errors associated with an
 410  * invalid fortran program. */
 411
 412 void
 413 runtime_error (const char *message, ...)
 414 {
 415   char buffer[ST_ERRBUF_SIZE];
 416   struct iovec iov[3];
 417   va_list ap;
 418   int written;
 419
 420   recursion_check ();
 421   iov[0].iov_base = (char*) "Fortran runtime error: ";
 422   iov[0].iov_len = strlen (iov[0].iov_base);
 423   va_start (ap, message);
 424   written = vsnprintf (buffer, ST_ERRBUF_SIZE, message, ap);
 425   va_end (ap);
 426   if (written >= 0)
 427     {
 428       iov[1].iov_base = buffer;
 429       iov[1].iov_len = written;
 430       iov[2].iov_base = (char*) "\n";
 431       iov[2].iov_len = 1;
 432       estr_writev (iov, 3);
 433     }
 434   exit_error (2);
 435 }
 436 iexport(runtime_error);
 437
 438 /* void runtime_error_at()-- These are errors associated with a
 439  * run time error generated by the front end compiler.  */
 440
 441 void
 442 runtime_error_at (const char *where, const char *message, ...)
 443 {
 444   char buffer[ST_ERRBUF_SIZE];
 445   va_list ap;
 446   struct iovec iov[4];
 447   int written;
 448
 449   recursion_check ();
 450   iov[0].iov_base = (char*) where;
 451   iov[0].iov_len = strlen (where);
 452   iov[1].iov_base = (char*) "\nFortran runtime error: ";
 453   iov[1].iov_len = strlen (iov[1].iov_base);
 454   va_start (ap, message);
 455   written = vsnprintf (buffer, ST_ERRBUF_SIZE, message, ap);
 456   va_end (ap);
 457   if (written >= 0)
 458     {
 459       iov[2].iov_base = buffer;
 460       iov[2].iov_len = written;
 461       iov[3].iov_base = (char*) "\n";
 462       iov[3].iov_len = 1;
 463       estr_writev (iov, 4);
 464     }
 465   exit_error (2);
 466 }
 467 iexport(runtime_error_at);
 468
 469
 470 void
 471 runtime_warning_at (const char *where, const char *message, ...)
 472 {
 473   char buffer[ST_ERRBUF_SIZE];
 474   va_list ap;
 475   struct iovec iov[4];
 476   int written;
 477
 478   iov[0].iov_base = (char*) where;
 479   iov[0].iov_len = strlen (where);
 480   iov[1].iov_base = (char*) "\nFortran runtime warning: ";
 481   iov[1].iov_len = strlen (iov[1].iov_base);
 482   va_start (ap, message);
 483   written = vsnprintf (buffer, ST_ERRBUF_SIZE, message, ap);
 484   va_end (ap);
 485   if (written >= 0)
 486     {
 487       iov[2].iov_base = buffer;
 488       iov[2].iov_len = written;
 489       iov[3].iov_base = (char*) "\n";
 490       iov[3].iov_len = 1;
 491       estr_writev (iov, 4);
 492     }
 493 }
 494 iexport(runtime_warning_at);
 495
 496
 497 /* void internal_error()-- These are this-can't-happen errors
 498  * that indicate something deeply wrong. */
 499
 500 void
 501 internal_error (st_parameter_common *cmp, const char *message)
 502 {
 503   struct iovec iov[3];
 504
 505   recursion_check ();
 506   show_locus (cmp);
 507   iov[0].iov_base = (char*) "Internal Error: ";
 508   iov[0].iov_len = strlen (iov[0].iov_base);
 509   iov[1].iov_base = (char*) message;
 510   iov[1].iov_len = strlen (message);
 511   iov[2].iov_base = (char*) "\n";
 512   iov[2].iov_len = 1;
 513   estr_writev (iov, 3);
 514
 515   /* This function call is here to get the main.o object file included
 516      when linking statically. This works because error.o is supposed to
 517      be always linked in (and the function call is in internal_error
 518      because hopefully it doesn't happen too often).  */
 519   stupid_function_name_for_static_linking();
 520
 521  exit_error (3);
 522 }
 523
 524
 525 /* translate_error()-- Given an integer error code, return a string
 526  * describing the error. */
 527
 528 const char *
 529 translate_error (int code)
 530 {
 531   const char *p;
 532
 533   switch (code)
 534     {
 535     case LIBERROR_EOR:
 536       p = "End of record";
 537       break;
 538
 539     case LIBERROR_END:
 540       p = "End of file";
 541       break;
 542
 543     case LIBERROR_OK:
 544       p = "Successful return";
 545       break;
 546
 547     case LIBERROR_OS:
 548       p = "Operating system error";
 549       break;
 550
 551     case LIBERROR_BAD_OPTION:
 552       p = "Bad statement option";
 553       break;
 554
 555     case LIBERROR_MISSING_OPTION:
 556       p = "Missing statement option";
 557       break;
 558
 559     case LIBERROR_OPTION_CONFLICT:
 560       p = "Conflicting statement options";
 561       break;
 562
 563     case LIBERROR_ALREADY_OPEN:
 564       p = "File already opened in another unit";
 565       break;
 566
 567     case LIBERROR_BAD_UNIT:
 568       p = "Unattached unit";
 569       break;
 570
 571     case LIBERROR_FORMAT:
 572       p = "FORMAT error";
 573       break;
 574
 575     case LIBERROR_BAD_ACTION:
 576       p = "Incorrect ACTION specified";
 577       break;
 578
 579     case LIBERROR_ENDFILE:
 580       p = "Read past ENDFILE record";
 581       break;
 582
 583     case LIBERROR_BAD_US:
 584       p = "Corrupt unformatted sequential file";
 585       break;
 586
 587     case LIBERROR_READ_VALUE:
 588       p = "Bad value during read";
 589       break;
 590
 591     case LIBERROR_READ_OVERFLOW:
 592       p = "Numeric overflow on read";
 593       break;
 594
 595     case LIBERROR_INTERNAL:
 596       p = "Internal error in run-time library";
 597       break;
 598
 599     case LIBERROR_INTERNAL_UNIT:
 600       p = "Internal unit I/O error";
 601       break;
 602
 603     case LIBERROR_DIRECT_EOR:
 604       p = "Write exceeds length of DIRECT access record";
 605       break;
 606
 607     case LIBERROR_SHORT_RECORD:
 608       p = "I/O past end of record on unformatted file";
 609       break;
 610
 611     case LIBERROR_CORRUPT_FILE:
 612       p = "Unformatted file structure has been corrupted";
 613       break;
 614
 615     case LIBERROR_INQUIRE_INTERNAL_UNIT:
 616       p = "Inquire statement identifies an internal file";
 617       break;
 618
 619     default:
 620       p = "Unknown error code";
 621       break;
 622     }
 623
 624   return p;
 625 }
 626
 627
 628 /* Worker function for generate_error and generate_error_async.  Return true
 629    if a straight return is to be done, zero if the program should abort. */
 630
 631 bool
 632 generate_error_common (st_parameter_common *cmp, int family, const char *message)
 633 {
 634   char errmsg[STRERR_MAXSZ];
 635
 636 #if ASYNC_IO
 637   gfc_unit *u;
 638
 639   NOTE ("Entering generate_error_common");
 640
 641   u = thread_unit;
 642   if (u && u->au)
 643     {
 644       if (u->au->error.has_error)
 645         return true;
 646
 647       if (__gthread_equal (u->au->thread, __gthread_self ()))
 648         {
 649           u->au->error.has_error = 1;
 650           u->au->error.cmp = cmp;
 651           u->au->error.family = family;
 652           u->au->error.message = message;
 653           return true;
 654         }
 655     }
 656 #endif
 657
 658   /* If there was a previous error, don't mask it with another
 659      error message, EOF or EOR condition.  */
 660
 661   if ((cmp->flags & IOPARM_LIBRETURN_MASK) == IOPARM_LIBRETURN_ERROR)
 662     return true;
 663
 664   /* Set the error status.  */
 665   if ((cmp->flags & IOPARM_HAS_IOSTAT))
 666     *cmp->iostat = (family == LIBERROR_OS) ? errno : family;
 667
 668   if (message == NULL)
 669     message =
 670       (family == LIBERROR_OS) ? gf_strerror (errno, errmsg, STRERR_MAXSZ) :
 671       translate_error (family);
 672
 673   if (cmp->flags & IOPARM_HAS_IOMSG)
 674     cf_strcpy (cmp->iomsg, cmp->iomsg_len, message);
 675
 676   /* Report status back to the compiler.  */
 677   cmp->flags &= ~IOPARM_LIBRETURN_MASK;
 678   switch (family)
 679     {
 680     case LIBERROR_EOR:
 681       cmp->flags |= IOPARM_LIBRETURN_EOR;  NOTE("EOR");
 682       if ((cmp->flags & IOPARM_EOR))
 683         return true;
 684       break;
 685
 686     case LIBERROR_END:
 687       cmp->flags |= IOPARM_LIBRETURN_END; NOTE("END");
 688       if ((cmp->flags & IOPARM_END))
 689         return true;
 690       break;
 691
 692     default:
 693       cmp->flags |= IOPARM_LIBRETURN_ERROR; NOTE("ERROR");
 694       if ((cmp->flags & IOPARM_ERR))
 695         return true;
 696       break;
 697     }
 698
 699   /* Return if the user supplied an iostat variable.  */
 700   if ((cmp->flags & IOPARM_HAS_IOSTAT))
 701     return true;
 702
 703   /* Return code, caller is responsible for terminating
 704    the program if necessary.  */
 705
 706   recursion_check ();
 707   show_locus (cmp);
 708   struct iovec iov[3];
 709   iov[0].iov_base = (char*) "Fortran runtime error: ";
 710   iov[0].iov_len = strlen (iov[0].iov_base);
 711   iov[1].iov_base = (char*) message;
 712   iov[1].iov_len = strlen (message);
 713   iov[2].iov_base = (char*) "\n";
 714   iov[2].iov_len = 1;
 715   estr_writev (iov, 3);
 716   return false;
 717 }
 718
 719 /* generate_error()-- Come here when an error happens.  This
 720  * subroutine is called if it is possible to continue on after the error.
 721  * If an IOSTAT or IOMSG variable exists, we set it.  If IOSTAT or
 722  * ERR labels are present, we return, otherwise we terminate the program
 723  * after printing a message.  The error code is always required but the
 724  * message parameter can be NULL, in which case a string describing
 725  * the most recent operating system error is used.
 726  * If the error is for an asynchronous unit and if the program is currently
 727  * executing the asynchronous thread, just mark the error and return.  */
 728
 729 void
 730 generate_error (st_parameter_common *cmp, int family, const char *message)
 731 {
 732   if (generate_error_common (cmp, family, message))
 733     return;
 734
 735   exit_error(2);
 736 }
 737 iexport(generate_error);
 738
 739
 740 /* generate_warning()-- Similar to generate_error but just give a warning.  */
 741
 742 void
 743 generate_warning (st_parameter_common *cmp, const char *message)
 744 {
 745   if (message == NULL)
 746     message = " ";
 747
 748   show_locus (cmp);
 749   struct iovec iov[3];
 750   iov[0].iov_base = (char*) "Fortran runtime warning: ";
 751   iov[0].iov_len = strlen (iov[0].iov_base);
 752   iov[1].iov_base = (char*) message;
 753   iov[1].iov_len = strlen (message);
 754   iov[2].iov_base = (char*) "\n";
 755   iov[2].iov_len = 1;
 756   estr_writev (iov, 3);
 757 }
 758
 759
 760 /* Whether, for a feature included in a given standard set (GFC_STD_*),
 761    we should issue an error or a warning, or be quiet.  */
 762
 763 notification
 764 notification_std (int std)
 765 {
 766   int warning;
 767
 768   if (!compile_options.pedantic)
 769     return NOTIFICATION_SILENT;
 770
 771   warning = compile_options.warn_std & std;
 772   if ((compile_options.allow_std & std) != 0 && !warning)
 773     return NOTIFICATION_SILENT;
 774
 775   return warning ? NOTIFICATION_WARNING : NOTIFICATION_ERROR;
 776 }
 777
 778
 779 /* Possibly issue a warning/error about use of a nonstandard (or deleted)
 780    feature.  An error/warning will be issued if the currently selected
 781    standard does not contain the requested bits.  */
 782
 783 bool
 784 notify_std (st_parameter_common *cmp, int std, const char * message)
 785 {
 786   int warning;
 787   struct iovec iov[3];
 788
 789   if (!compile_options.pedantic)
 790     return true;
 791
 792   warning = compile_options.warn_std & std;
 793   if ((compile_options.allow_std & std) != 0 && !warning)
 794     return true;
 795
 796   if (!warning)
 797     {
 798       recursion_check ();
 799       show_locus (cmp);
 800       iov[0].iov_base = (char*) "Fortran runtime error: ";
 801       iov[0].iov_len = strlen (iov[0].iov_base);
 802       iov[1].iov_base = (char*) message;
 803       iov[1].iov_len = strlen (message);
 804       iov[2].iov_base = (char*) "\n";
 805       iov[2].iov_len = 1;
 806       estr_writev (iov, 3);
 807       exit_error (2);
 808     }
 809   else
 810     {
 811       show_locus (cmp);
 812       iov[0].iov_base = (char*) "Fortran runtime warning: ";
 813       iov[0].iov_len = strlen (iov[0].iov_base);
 814       iov[1].iov_base = (char*) message;
 815       iov[1].iov_len = strlen (message);
 816       iov[2].iov_base = (char*) "\n";
 817       iov[2].iov_len = 1;
 818       estr_writev (iov, 3);
 819     }
 820   return false;
 821 }