gcc/fortran/error.c

   1 /* Handle errors.
   2    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation,
   3    Inc.
   4    Contributed by Andy Vaught & Niels Kristian Bech Jensen
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to the Free
  20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23 /* Handle the inevitable errors.  A major catch here is that things
  24    flagged as errors in one match subroutine can conceivably be legal
  25    elsewhere.  This means that error messages are recorded and saved
  26    for possible use later.  If a line does not match a legal
  27    construction, then the saved error message is reported.  */
  28
  29 #include "config.h"
  30 #include "system.h"
  31 #include "flags.h"
  32 #include "gfortran.h"
  33
  34 int gfc_suppress_error = 0;
  35
  36 static int terminal_width, buffer_flag, errors,
  37   use_warning_buffer, warnings;
  38
  39 static char *error_ptr, *warning_ptr;
  40
  41 static gfc_error_buf error_buffer, warning_buffer;
  42
  43
  44 /* Per-file error initialization.  */
  45
  46 void
  47 gfc_error_init_1 (void)
  48 {
  49   terminal_width = gfc_terminal_width ();
  50   errors = 0;
  51   warnings = 0;
  52   buffer_flag = 0;
  53 }
  54
  55
  56 /* Set the flag for buffering errors or not.  */
  57
  58 void
  59 gfc_buffer_error (int flag)
  60 {
  61   buffer_flag = flag;
  62 }
  63
  64
  65 /* Add a single character to the error buffer or output depending on
  66    buffer_flag.  */
  67
  68 static void
  69 error_char (char c)
  70 {
  71   if (buffer_flag)
  72     {
  73       if (use_warning_buffer)
  74         {
  75           *warning_ptr++ = c;
  76           if (warning_ptr - warning_buffer.message >= MAX_ERROR_MESSAGE)
  77             gfc_internal_error ("error_char(): Warning buffer overflow");
  78         }
  79       else
  80         {
  81           *error_ptr++ = c;
  82           if (error_ptr - error_buffer.message >= MAX_ERROR_MESSAGE)
  83             gfc_internal_error ("error_char(): Error buffer overflow");
  84         }
  85     }
  86   else
  87     {
  88       if (c != 0)
  89         {
  90           /* We build up complete lines before handing things
  91              over to the library in order to speed up error printing.  */
  92           static char line[MAX_ERROR_MESSAGE + 1];
  93           static int index = 0;
  94
  95           line[index++] = c;
  96           if (c == '\n' || index == MAX_ERROR_MESSAGE)
  97             {
  98               line[index] = '\0';
  99               fputs (line, stderr);
 100               index = 0;
 101             }
 102         }
 103     }
 104 }
 105
 106
 107 /* Copy a string to wherever it needs to go.  */
 108
 109 static void
 110 error_string (const char *p)
 111 {
 112   while (*p)
 113     error_char (*p++);
 114 }
 115
 116
 117 /* Show the file, where it was included and the source line, give a
 118    locus.  Calls error_printf() recursively, but the recursion is at
 119    most one level deep.  */
 120
 121 static void error_printf (const char *, ...) ATTRIBUTE_PRINTF_1;
 122
 123 static void
 124 show_locus (int offset, locus * loc)
 125 {
 126   gfc_linebuf *lb;
 127   gfc_file *f;
 128   char c, *p;
 129   int i, m;
 130
 131   /* TODO: Either limit the total length and number of included files
 132      displayed or add buffering of arbitrary number of characters in
 133      error messages.  */
 134
 135   lb = loc->lb;
 136   f = lb->file;
 137   error_printf ("In file %s:%d\n", f->filename,
 138 #ifdef USE_MAPPED_LOCATION
 139                 LOCATION_LINE (lb->location)
 140 #else
 141                 lb->linenum
 142 #endif
 143                 );
 144
 145   for (;;)
 146     {
 147       i = f->inclusion_line;
 148
 149       f = f->included_by;
 150       if (f == NULL) break;
 151
 152       error_printf ("    Included at %s:%d\n", f->filename, i);
 153     }
 154
 155   /* Show the line itself, taking care not to print more than what can
 156      show up on the terminal.  Tabs are converted to spaces.  */
 157
 158   p = lb->line + offset;
 159   i = strlen (p);
 160   if (i > terminal_width)
 161     i = terminal_width - 1;
 162
 163   for (; i > 0; i--)
 164     {
 165       c = *p++;
 166       if (c == '\t')
 167         c = ' ';
 168
 169       if (ISPRINT (c))
 170         error_char (c);
 171       else
 172         {
 173           error_char ('\\');
 174           error_char ('x');
 175
 176           m = ((c >> 4) & 0x0F) + '0';
 177           if (m > '9')
 178             m += 'A' - '9' - 1;
 179           error_char (m);
 180
 181           m = (c & 0x0F) + '0';
 182           if (m > '9')
 183             m += 'A' - '9' - 1;
 184           error_char (m);
 185         }
 186     }
 187
 188   error_char ('\n');
 189 }
 190
 191
 192 /* As part of printing an error, we show the source lines that caused
 193    the problem.  We show at least one, possibly two loci.  If we're
 194    showing two loci and they both refer to the same file and line, we
 195    only print the line once.  */
 196
 197 static void
 198 show_loci (locus * l1, locus * l2)
 199 {
 200   int offset, flag, i, m, c1, c2, cmax;
 201
 202   if (l1 == NULL)
 203     {
 204       error_printf ("<During initialization>\n");
 205       return;
 206     }
 207
 208   c1 = l1->nextc - l1->lb->line;
 209   c2 = 0;
 210   if (l2 == NULL)
 211     goto separate;
 212
 213   c2 = l2->nextc - l2->lb->line;
 214
 215   if (c1 < c2)
 216     m = c2 - c1;
 217   else
 218     m = c1 - c2;
 219
 220
 221   if (l1->lb != l2->lb || m > terminal_width - 10)
 222     goto separate;
 223
 224   offset = 0;
 225   cmax = (c1 < c2) ? c2 : c1;
 226   if (cmax > terminal_width - 5)
 227     offset = cmax - terminal_width + 5;
 228
 229   if (offset < 0)
 230     offset = 0;
 231
 232   c1 -= offset;
 233   c2 -= offset;
 234
 235   show_locus (offset, l1);
 236
 237   /* Arrange that '1' and '2' will show up even if the two columns are equal.  */
 238   for (i = 1; i <= cmax; i++)
 239     {
 240       flag = 0;
 241       if (i == c1)
 242         {
 243           error_char ('1');
 244           flag = 1;
 245         }
 246       if (i == c2)
 247         {
 248           error_char ('2');
 249           flag = 1;
 250         }
 251       if (flag == 0)
 252         error_char (' ');
 253     }
 254
 255   error_char ('\n');
 256
 257   return;
 258
 259 separate:
 260   offset = 0;
 261
 262   if (c1 > terminal_width - 5)
 263     {
 264       offset = c1 - 5;
 265       if (offset < 0)
 266         offset = 0;
 267       c1 = c1 - offset;
 268     }
 269
 270   show_locus (offset, l1);
 271   for (i = 1; i < c1; i++)
 272     error_char (' ');
 273
 274   error_char ('1');
 275   error_char ('\n');
 276
 277   if (l2 != NULL)
 278     {
 279       offset = 0;
 280
 281       if (c2 > terminal_width - 20)
 282         {
 283           offset = c2 - 20;
 284           if (offset < 0)
 285             offset = 0;
 286           c2 = c2 - offset;
 287         }
 288
 289       show_locus (offset, l2);
 290
 291       for (i = 1; i < c2; i++)
 292         error_char (' ');
 293
 294       error_char ('2');
 295       error_char ('\n');
 296     }
 297 }
 298
 299
 300 /* Workhorse for the error printing subroutines.  This subroutine is
 301    inspired by g77's error handling and is similar to printf() with
 302    the following %-codes:
 303
 304    %c Character, %d Integer, %s String, %% Percent
 305    %L  Takes locus argument
 306    %C  Current locus (no argument)
 307
 308    If a locus pointer is given, the actual source line is printed out
 309    and the column is indicated.  Since we want the error message at
 310    the bottom of any source file information, we must scan the
 311    argument list twice.  A maximum of two locus arguments are
 312    permitted.  */
 313
 314 #define IBUF_LEN 30
 315 #define MAX_ARGS 10
 316
 317 static void
 318 error_print (const char *type, const char *format0, va_list argp)
 319 {
 320   char c, *p, int_buf[IBUF_LEN], c_arg[MAX_ARGS], *cp_arg[MAX_ARGS];
 321   int i, n, have_l1, i_arg[MAX_ARGS];
 322   locus *l1, *l2, *loc;
 323   const char *format;
 324
 325   l1 = l2 = loc = NULL;
 326
 327   have_l1 = 0;
 328
 329   n = 0;
 330   format = format0;
 331
 332   while (*format)
 333     {
 334       c = *format++;
 335       if (c == '%')
 336         {
 337           c = *format++;
 338
 339           switch (c)
 340             {
 341             case '%':
 342               break;
 343
 344             case 'L':
 345               loc = va_arg (argp, locus *);
 346               /* Fall through */
 347
 348             case 'C':
 349               if (c == 'C')
 350                 loc = &gfc_current_locus;
 351
 352               if (have_l1)
 353                 {
 354                   l2 = loc;
 355                 }
 356               else
 357                 {
 358                   l1 = loc;
 359                   have_l1 = 1;
 360                 }
 361               break;
 362
 363             case 'd':
 364             case 'i':
 365               i_arg[n++] = va_arg (argp, int);
 366               break;
 367
 368             case 'c':
 369               c_arg[n++] = va_arg (argp, int);
 370               break;
 371
 372             case 's':
 373               cp_arg[n++] = va_arg (argp, char *);
 374               break;
 375             }
 376         }
 377     }
 378
 379   /* Show the current loci if we have to.  */
 380   if (have_l1)
 381     show_loci (l1, l2);
 382   error_string (type);
 383   error_char (' ');
 384
 385   have_l1 = 0;
 386   format = format0;
 387   n = 0;
 388
 389   for (; *format; format++)
 390     {
 391       if (*format != '%')
 392         {
 393           error_char (*format);
 394           continue;
 395         }
 396
 397       format++;
 398       switch (*format)
 399         {
 400         case '%':
 401           error_char ('%');
 402           break;
 403
 404         case 'c':
 405           error_char (c_arg[n++]);
 406           break;
 407
 408         case 's':
 409           error_string (cp_arg[n++]);
 410           break;
 411
 412         case 'i':
 413         case 'd':
 414           i = i_arg[n++];
 415
 416           if (i < 0)
 417             {
 418               i = -i;
 419               error_char ('-');
 420             }
 421
 422           p = int_buf + IBUF_LEN - 1;
 423           *p-- = '\0';
 424
 425           if (i == 0)
 426             *p-- = '0';
 427
 428           while (i > 0)
 429             {
 430               *p-- = i % 10 + '0';
 431               i = i / 10;
 432             }
 433
 434           error_string (p + 1);
 435           break;
 436
 437         case 'C':               /* Current locus */
 438         case 'L':               /* Specified locus */
 439           error_string (have_l1 ? "(2)" : "(1)");
 440           have_l1 = 1;
 441           break;
 442         }
 443     }
 444
 445   error_char ('\n');
 446 }
 447
 448
 449 /* Wrapper for error_print().  */
 450
 451 static void
 452 error_printf (const char *format, ...)
 453 {
 454   va_list argp;
 455
 456   va_start (argp, format);
 457   error_print ("", format, argp);
 458   va_end (argp);
 459 }
 460
 461
 462 /* Issue a warning.  */
 463
 464 void
 465 gfc_warning (const char *format, ...)
 466 {
 467   va_list argp;
 468
 469   if (inhibit_warnings)
 470     return;
 471
 472   warning_buffer.flag = 1;
 473   warning_ptr = warning_buffer.message;
 474   use_warning_buffer = 1;
 475
 476   va_start (argp, format);
 477   if (buffer_flag == 0)
 478     warnings++;
 479   error_print ("Warning:", format, argp);
 480   va_end (argp);
 481
 482   error_char ('\0');
 483 }
 484
 485
 486 /* Possibly issue a warning/error about use of a nonstandard (or deleted)
 487    feature.  An error/warning will be issued if the currently selected
 488    standard does not contain the requested bits.  Return FAILURE if
 489    and error is generated.  */
 490
 491 try
 492 gfc_notify_std (int std, const char *format, ...)
 493 {
 494   va_list argp;
 495   bool warning;
 496
 497   warning = ((gfc_option.warn_std & std) != 0)
 498             && !inhibit_warnings;
 499   if ((gfc_option.allow_std & std) != 0
 500       && !warning)
 501     return SUCCESS;
 502
 503   if (gfc_suppress_error)
 504     return warning ? SUCCESS : FAILURE;
 505
 506   if (warning)
 507     {
 508       warning_buffer.flag = 1;
 509       warning_ptr = warning_buffer.message;
 510       use_warning_buffer = 1;
 511     }
 512   else
 513     {
 514       error_buffer.flag = 1;
 515       error_ptr = error_buffer.message;
 516       use_warning_buffer = 0;
 517     }
 518
 519   if (buffer_flag == 0)
 520     {
 521       if (warning)
 522         warnings++;
 523       else
 524         errors++;
 525     }
 526   va_start (argp, format);
 527   if (warning)
 528     error_print ("Warning:", format, argp);
 529   else
 530     error_print ("Error:", format, argp);
 531   va_end (argp);
 532
 533   error_char ('\0');
 534   return warning ? SUCCESS : FAILURE;
 535 }
 536
 537
 538 /* Immediate warning (i.e. do not buffer the warning).  */
 539
 540 void
 541 gfc_warning_now (const char *format, ...)
 542 {
 543   va_list argp;
 544   int i;
 545
 546   if (inhibit_warnings)
 547     return;
 548
 549   i = buffer_flag;
 550   buffer_flag = 0;
 551   warnings++;
 552
 553   va_start (argp, format);
 554   error_print ("Warning:", format, argp);
 555   va_end (argp);
 556
 557   error_char ('\0');
 558   buffer_flag = i;
 559 }
 560
 561
 562 /* Clear the warning flag.  */
 563
 564 void
 565 gfc_clear_warning (void)
 566 {
 567   warning_buffer.flag = 0;
 568 }
 569
 570
 571 /* Check to see if any warnings have been saved.
 572    If so, print the warning.  */
 573
 574 void
 575 gfc_warning_check (void)
 576 {
 577   if (warning_buffer.flag)
 578     {
 579       warnings++;
 580       fputs (warning_buffer.message, stderr);
 581       warning_buffer.flag = 0;
 582     }
 583 }
 584
 585
 586 /* Issue an error.  */
 587
 588 void
 589 gfc_error (const char *format, ...)
 590 {
 591   va_list argp;
 592
 593   if (gfc_suppress_error)
 594     return;
 595
 596   error_buffer.flag = 1;
 597   error_ptr = error_buffer.message;
 598   use_warning_buffer = 0;
 599
 600   va_start (argp, format);
 601   if (buffer_flag == 0)
 602     errors++;
 603   error_print ("Error:", format, argp);
 604   va_end (argp);
 605
 606   error_char ('\0');
 607 }
 608
 609
 610 /* Immediate error.  */
 611
 612 void
 613 gfc_error_now (const char *format, ...)
 614 {
 615   va_list argp;
 616   int i;
 617
 618   error_buffer.flag = 1;
 619   error_ptr = error_buffer.message;
 620
 621   i = buffer_flag;
 622   buffer_flag = 0;
 623   errors++;
 624
 625   va_start (argp, format);
 626   error_print ("Error:", format, argp);
 627   va_end (argp);
 628
 629   error_char ('\0');
 630   buffer_flag = i;
 631 }
 632
 633
 634 /* Fatal error, never returns.  */
 635
 636 void
 637 gfc_fatal_error (const char *format, ...)
 638 {
 639   va_list argp;
 640
 641   buffer_flag = 0;
 642
 643   va_start (argp, format);
 644   error_print ("Fatal Error:", format, argp);
 645   va_end (argp);
 646
 647   exit (3);
 648 }
 649
 650
 651 /* This shouldn't happen... but sometimes does.  */
 652
 653 void
 654 gfc_internal_error (const char *format, ...)
 655 {
 656   va_list argp;
 657
 658   buffer_flag = 0;
 659
 660   va_start (argp, format);
 661
 662   show_loci (&gfc_current_locus, NULL);
 663   error_printf ("Internal Error at (1):");
 664
 665   error_print ("", format, argp);
 666   va_end (argp);
 667
 668   exit (4);
 669 }
 670
 671
 672 /* Clear the error flag when we start to compile a source line.  */
 673
 674 void
 675 gfc_clear_error (void)
 676 {
 677   error_buffer.flag = 0;
 678 }
 679
 680
 681 /* Check to see if any errors have been saved.
 682    If so, print the error.  Returns the state of error_flag.  */
 683
 684 int
 685 gfc_error_check (void)
 686 {
 687   int rc;
 688
 689   rc = error_buffer.flag;
 690
 691   if (error_buffer.flag)
 692     {
 693       errors++;
 694       fputs (error_buffer.message, stderr);
 695       error_buffer.flag = 0;
 696     }
 697
 698   return rc;
 699 }
 700
 701
 702 /* Save the existing error state.  */
 703
 704 void
 705 gfc_push_error (gfc_error_buf * err)
 706 {
 707   err->flag = error_buffer.flag;
 708   if (error_buffer.flag)
 709     strcpy (err->message, error_buffer.message);
 710
 711   error_buffer.flag = 0;
 712 }
 713
 714
 715 /* Restore a previous pushed error state.  */
 716
 717 void
 718 gfc_pop_error (gfc_error_buf * err)
 719 {
 720   error_buffer.flag = err->flag;
 721   if (error_buffer.flag)
 722     strcpy (error_buffer.message, err->message);
 723 }
 724
 725
 726 /* Debug wrapper for printf.  */
 727
 728 void
 729 gfc_status (const char *format, ...)
 730 {
 731   va_list argp;
 732
 733   va_start (argp, format);
 734
 735   vprintf (format, argp);
 736
 737   va_end (argp);
 738 }
 739
 740
 741 /* Subroutine for outputting a single char so that we don't have to go
 742    around creating a lot of 1-character strings.  */
 743
 744 void
 745 gfc_status_char (char c)
 746 {
 747   putchar (c);
 748 }
 749
 750
 751 /* Report the number of warnings and errors that occurred to the caller.  */
 752
 753 void
 754 gfc_get_errors (int *w, int *e)
 755 {
 756   if (w != NULL)
 757     *w = warnings;
 758   if (e != NULL)
 759     *e = errors;
 760 }