aboutsummaryrefslogtreecommitdiff
path: root/gdb/source.c
blob: ebc7041bf98154b94cee2b9d36add1ebac489057 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
/* List lines of source files for GDB, the GNU debugger.
   Copyright (C) 1986, 1987, 1988, 1989, 1991 Free Software Foundation, Inc.

This file is part of GDB.

GDB is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.

GDB is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GDB; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include <stdio.h>
#include "defs.h"
#include "symtab.h"
#include "param.h"
#include "command.h"
#include "frame.h"

#ifdef USG
#include <sys/types.h>
#endif

#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "gdbcore.h"

extern char *strstr();

extern void set_next_address ();

void mod_path ();

/* Path of directories to search for source files.
   Same format as the PATH environment variable's value.  */

char *source_path;

/* Symtab of default file for listing lines of.  */

struct symtab *current_source_symtab;

/* Default next line to list.  */

int current_source_line;

/* Line number of last line printed.  Default for various commands.
   current_source_line is usually, but not always, the same as this.  */

static int last_line_listed;

/* First line number listed by last listing command.  */

static int first_line_listed;


/* Set the source file default for the "list" command, specifying a
   symtab.  Sigh.  Behavior specification: If it is called with a
   non-zero argument, that is the symtab to select.  If it is not,
   first lookup "main"; if it exists, use the symtab and line it
   defines.  If not, take the last symtab in the symtab_list (if it
   exists) or the last symtab in the psymtab_list (if *it* exists).  If
   none of this works, report an error.   */

void
select_source_symtab (s)
     register struct symtab *s;
{
  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  struct partial_symtab *ps;
  struct partial_symtab *cs_pst = 0;
  
  if (s)
    {
      current_source_symtab = s;
      current_source_line = 1;
      return;
    }

  /* Make the default place to list be the function `main'
     if one exists.  */
  if (lookup_symbol ("main", 0, VAR_NAMESPACE, 0, NULL))
    {
      sals = decode_line_spec ("main", 1);
      sal = sals.sals[0];
      free (sals.sals);
      current_source_symtab = sal.symtab;
      current_source_line = max (sal.line - (lines_to_list () - 1), 1);
      return;
    }
  
  /* All right; find the last file in the symtab list (ignoring .h's).  */

  if (s = symtab_list)
    {
      do
	{
	  char *name = s->filename;
	  int len = strlen (name);
	  if (! (len > 2 && !strcmp (&name[len - 2], ".h")))
	    current_source_symtab = s;
	  s = s->next;
	}
      while (s);
      current_source_line = 1;
    }
  else if (partial_symtab_list)
    {
      ps = partial_symtab_list;
      while (ps)
	{
	  char *name = ps->filename;
	  int len = strlen (name);
	  if (! (len > 2 && !strcmp (&name[len - 2], ".h")))
	    cs_pst = ps;
	  ps = ps->next;
	}
      if (cs_pst)
	if (cs_pst->readin)
	  fatal ("Internal: select_source_symtab: readin pst found and no symtabs.");
	else
	  current_source_symtab = PSYMTAB_TO_SYMTAB (cs_pst);
      else
	current_source_symtab = 0;
      current_source_line = 1;
    }
}

static void
directories_info ()
{
  printf ("Source directories searched: %s\n", source_path);
}

/* Forget what we learned about line positions in source files,
   and which directories contain them;
   must check again now since files may be found in
   a different directory now.  */

void
forget_cached_source_info ()
{
  register struct symtab *s;

  for (s = symtab_list; s; s = s->next)
    {
      if (s->line_charpos != 0)
	{
	  free (s->line_charpos);
	  s->line_charpos = 0;
	}
      if (s->fullname != 0)
	{
	  free (s->fullname);
	  s->fullname = 0;
	}
    }
}

void
init_source_path ()
{
  source_path = savestring ("$cdir:$cwd", /* strlen of it */ 10);
  forget_cached_source_info ();
}

/* Add zero or more directories to the front of the source path.  */
 
void
directory_command (dirname, from_tty)
     char *dirname;
     int from_tty;
{
  dont_repeat ();
  /* FIXME, this goes to "delete dir"... */
  if (dirname == 0)
    {
      if (query ("Reinitialize source path to empty? ", ""))
	{
	  free (source_path);
	  init_source_path ();
	}
    }
  else
    mod_path (dirname, from_tty, &source_path);
  if (from_tty)
    directories_info ();
  forget_cached_source_info ();
}

/* Add zero or more directories to the front of an arbitrary path.  */

void
mod_path (dirname, from_tty, which_path)
     char *dirname;
     int from_tty;
     char **which_path;
{
  char *old = *which_path;
  int prefix = 0;

  if (dirname == 0)
    return;

  dirname = strsave (dirname);
  make_cleanup (free, dirname);

  do
    {
      extern char *index ();
      char *name = dirname;
      register char *p;
      struct stat st;

      {
	char *colon = index (name, ':');
	char *space = index (name, ' ');
	char *tab = index (name, '\t');
	if (colon == 0 && space == 0 && tab ==  0)
	  p = dirname = name + strlen (name);
	else
	  {
	    p = 0;
	    if (colon != 0 && (p == 0 || colon < p))
	      p = colon;
	    if (space != 0 && (p == 0 || space < p))
	      p = space;
	    if (tab != 0 && (p == 0 || tab < p))
	      p = tab;
	    dirname = p + 1;
	    while (*dirname == ':' || *dirname == ' ' || *dirname == '\t')
	      ++dirname;
	  }
      }

      if (p[-1] == '/')
	/* Sigh. "foo/" => "foo" */
	--p;
      *p = '\0';

      while (p[-1] == '.')
	{
	  if (p - name == 1)
	    {
	      /* "." => getwd ().  */
	      name = current_directory;
	      goto append;
	    }
	  else if (p[-2] == '/')
	    {
	      if (p - name == 2)
		{
		  /* "/." => "/".  */
		  *--p = '\0';
		  goto append;
		}
	      else
		{
		  /* "...foo/." => "...foo".  */
		  p -= 2;
		  *p = '\0';
		  continue;
		}
	    }
	  else
	    break;
	}

      if (name[0] == '~')
	name = tilde_expand (name);
      else if (name[0] != '/' && name[0] != '$')
	name = concat (current_directory, "/", name);
      else
	name = savestring (name, p - name);
      make_cleanup (free, name);

      /* Unless it's a variable, check existence.  */
      if (name[0] != '$') {
	if (stat (name, &st) < 0)
	  perror_with_name (name);
	if ((st.st_mode & S_IFMT) != S_IFDIR)
	  error ("%s is not a directory.", name);
      }

    append:
      {
	register unsigned int len = strlen (name);

	p = *which_path;
	while (1)
	  {
	    if (!strncmp (p, name, len)
		&& (p[len] == '\0' || p[len] == ':'))
	      {
		/* Found it in the search path, remove old copy */
		if (p > *which_path)
		  p--;			/* Back over leading colon */
		if (prefix > p - *which_path)
		  goto skip_dup;	/* Same dir twice in one cmd */
		strcpy (p, &p[len+1]);	/* Copy from next \0 or  : */
	      }
	    p = index (p, ':');
	    if (p != 0)
	      ++p;
	    else
	      break;
	  }
	if (p == 0)
	  {
	    /* If we have already tacked on a name(s) in this command,			   be sure they stay on the front as we tack on some more.  */
	    if (prefix)
	      {
		char *temp, c;

		c = old[prefix];
		old[prefix] = '\0';
		temp = concat (old, ":", name);
		old[prefix] = c;
		*which_path = concat (temp, "", &old[prefix]);
		prefix = strlen (temp);
		free (temp);
	      }
	    else
	      {
		*which_path = concat (name, (old[0]? ":" : old), old);
		prefix = strlen (name);
	      }
	    free (old);
	    old = *which_path;
	  }
      }
  skip_dup: ;
    } while (*dirname != '\0');
}


static void
source_info ()
{
  register struct symtab *s = current_source_symtab;

  if (!s)
    {
      printf("No current source file.\n");
      return;
    }
  printf ("Current source file is %s\n", s->filename);
  if (s->dirname)
    printf ("Compilation directory is %s\n", s->dirname);
  if (s->fullname)
    printf ("Located in %s\n", s->fullname);
  if (s->nlines)
    printf ("Contains %d lines\n", s->nlines);

  switch (s->language) {
  case language_c:
    printf("Written in the C language.\n");
  /* Add more cases here when -Wswitch complains... */
  case language_unknown:
    break;
  }
}



/* Open a file named STRING, searching path PATH (dir names sep by colons)
   using mode MODE and protection bits PROT in the calls to open.
   If TRY_CWD_FIRST, try to open ./STRING before searching PATH.
   (ie pretend the first element of PATH is ".")
   If FILENAMED_OPENED is non-null, set it to a newly allocated string naming
   the actual file opened (this string will always start with a "/".  We
   have to take special pains to avoid doubling the "/" between the directory
   and the file, sigh!  Emacs gets confuzzed by this when we print the
   source file name!!! 

   If a file is found, return the descriptor.
   Otherwise, return -1, with errno set for the last name we tried to open.  */

/*  >>>> This should only allow files of certain types,
    >>>>  eg executable, non-directory */
int
openp (path, try_cwd_first, string, mode, prot, filename_opened)
     char *path;
     int try_cwd_first;
     char *string;
     int mode;
     int prot;
     char **filename_opened;
{
  register int fd;
  register char *filename;
  register char *p, *p1;
  register int len;
  int alloclen;

  if (!path)
    path = ".";

  /* ./foo => foo */
  while (string[0] == '.' && string[1] == '/')
    string += 2;

  if (try_cwd_first || string[0] == '/')
    {
      filename = string;
      fd = open (filename, mode, prot);
      if (fd >= 0 || string[0] == '/')
	goto done;
    }

  alloclen = strlen (path) + strlen (string) + 2;
  filename = (char *) alloca (alloclen);
  fd = -1;
  for (p = path; p; p = p1 ? p1 + 1 : 0)
    {
      p1 = (char *) index (p, ':');
      if (p1)
	len = p1 - p;
      else
	len = strlen (p);

      if (len == 4 && p[0] == '$' && p[1] == 'c'
	           && p[2] == 'w' && p[3] == 'd') {
	/* Name is $cwd -- insert current directory name instead.  */
	int newlen;

	/* First, realloc the filename buffer if too short. */
	len = strlen (current_directory);
	newlen = len + strlen (string) + 2;
	if (newlen > alloclen) {
	  alloclen = newlen;
	  filename = (char *) alloca (alloclen);
	}
	strcpy (filename, current_directory);
      } else {
	/* Normal file name in path -- just use it.  */
	strncpy (filename, p, len);
	filename[len] = 0;
      }

      /* Beware the // my son, the Emacs barfs, the botch that catch... */
      while (len > 1 && filename[len-1] == '/')
	filename[--len] = 0;
      strcat (filename+len, "/");
      strcat (filename, string);

      fd = open (filename, mode, prot);
      if (fd >= 0) break;
    }

 done:
  if (filename_opened)
    if (fd < 0)
      *filename_opened = (char *) 0;
    else if (filename[0] == '/')
      *filename_opened = savestring (filename, strlen (filename));
    else
      {
	/* Beware the // my son, the Emacs barfs, the botch that catch... */
	   
	*filename_opened = concat (current_directory, 
	   '/' == current_directory[strlen(current_directory)-1]? "": "/",
				   filename);
      }

  return fd;
}

/* Open a source file given a symtab S.  Returns a file descriptor
   or negative number for error.  */
int
open_source_file (s)
     struct symtab *s;
{
  char *path = source_path;
  char *p;
  int result;

  /* Quick way out if we already know its full name */
  if (s->fullname) 
    {
      result = open (s->fullname, O_RDONLY);
      if (result >= 0)
        return result;
      /* Didn't work -- free old one, try again. */
      free (s->fullname);
      s->fullname = NULL;
    }

  if (s->dirname != NULL)
    {
      /* Replace a path entry of  $cdir  with the compilation directory name */
#define	cdir_len	5
      p = strstr (source_path, "$cdir");
      if (p && (p == path || p[-1] == ':')
	    && (p[cdir_len] == ':' || p[cdir_len] == '\0')) {
	int len;

	path = (char *)
	       alloca (strlen (source_path) + 1 + strlen (s->dirname) + 1);
	len = p - source_path;
	strncpy (path, source_path, len);		/* Before $cdir */
	strcpy (path + len, s->dirname);		/* new stuff */
	strcat (path + len, source_path + len + cdir_len); /* After $cdir */
      }
    }

  return openp (path, 0, s->filename, O_RDONLY, 0, &s->fullname);
}


/* Create and initialize the table S->line_charpos that records
   the positions of the lines in the source file, which is assumed
   to be open on descriptor DESC.
   All set S->nlines to the number of such lines.  */

static void
find_source_lines (s, desc)
     struct symtab *s;
     int desc;
{
  struct stat st;
  register char *data, *p, *end;
  int nlines = 0;
  int lines_allocated = 1000;
  int *line_charpos = (int *) xmalloc (lines_allocated * sizeof (int));

  if (fstat (desc, &st) < 0)
    perror_with_name (s->filename);
  if (exec_bfd && bfd_get_mtime(exec_bfd) < st.st_mtime)
    printf ("Source file is more recent than executable.\n");

#if defined (BROKEN_LARGE_ALLOCA)
  data = (char *) xmalloc (st.st_size);
  make_cleanup (free, data);
#else
  data = (char *) alloca (st.st_size);
#endif
  if (myread (desc, data, st.st_size) < 0)
    perror_with_name (s->filename);
  end = data + st.st_size;
  p = data;
  line_charpos[0] = 0;
  nlines = 1;
  while (p != end)
    {
      if (*p++ == '\n'
	  /* A newline at the end does not start a new line.  */
	  && p != end)
	{
	  if (nlines == lines_allocated)
	    {
	      lines_allocated *= 2;
	      line_charpos = (int *) xrealloc (line_charpos,
					       sizeof (int) * lines_allocated);
	    }
	  line_charpos[nlines++] = p - data;
	}
    }
  s->nlines = nlines;
  s->line_charpos = (int *) xrealloc (line_charpos, nlines * sizeof (int));
}

/* Return the character position of a line LINE in symtab S.
   Return 0 if anything is invalid.  */

int
source_line_charpos (s, line)
     struct symtab *s;
     int line;
{
  if (!s) return 0;
  if (!s->line_charpos || line <= 0) return 0;
  if (line > s->nlines)
    line = s->nlines;
  return s->line_charpos[line - 1];
}

/* Return the line number of character position POS in symtab S.  */

int
source_charpos_line (s, chr)
    register struct symtab *s;
    register int chr;
{
  register int line = 0;
  register int *lnp;
    
  if (s == 0 || s->line_charpos == 0) return 0;
  lnp = s->line_charpos;
  /* Files are usually short, so sequential search is Ok */
  while (line < s->nlines  && *lnp <= chr)
    {
      line++;
      lnp++;
    }
  if (line >= s->nlines)
    line = s->nlines;
  return line;
}

/* Get full pathname and line number positions for a symtab.
   Return nonzero if line numbers may have changed.
   Set *FULLNAME to actual name of the file as found by `openp',
   or to 0 if the file is not found.  */

int
get_filename_and_charpos (s, fullname)
     struct symtab *s;
     char **fullname;
{
  register int desc, linenums_changed = 0;
  
  desc = open_source_file (s);
  if (desc < 0)
    {
      if (fullname)
	*fullname = NULL;
      return 0;
    }  
  if (fullname)
    *fullname = s->fullname;
  if (s->line_charpos == 0) linenums_changed = 1;
  if (linenums_changed) find_source_lines (s, desc);
  close (desc);
  return linenums_changed;
}

/* Print text describing the full name of the source file S
   and the line number LINE and its corresponding character position.
   The text starts with two Ctrl-z so that the Emacs-GDB interface
   can easily find it.

   MID_STATEMENT is nonzero if the PC is not at the beginning of that line.

   Return 1 if successful, 0 if could not find the file.  */

int
identify_source_line (s, line, mid_statement)
     struct symtab *s;
     int line;
     int mid_statement;
{
  if (s->line_charpos == 0)
    get_filename_and_charpos (s, (char **)NULL);
  if (s->fullname == 0)
    return 0;
  printf ("\032\032%s:%d:%d:%s:0x%x\n", s->fullname,
	  line, s->line_charpos[line - 1],
	  mid_statement ? "middle" : "beg",
	  get_frame_pc (get_current_frame()));
  current_source_line = line;
  first_line_listed = line;
  last_line_listed = line;
  current_source_symtab = s;
  return 1;
}

/* Print source lines from the file of symtab S,
   starting with line number LINE and stopping before line number STOPLINE.  */

void
print_source_lines (s, line, stopline, noerror)
     struct symtab *s;
     int line, stopline;
     int noerror;
{
  register int c;
  register int desc;
  register FILE *stream;
  int nlines = stopline - line;

  /* Regardless of whether we can open the file, set current_source_symtab. */
  current_source_symtab = s;
  current_source_line = line;
  first_line_listed = line;

  desc = open_source_file (s);
  if (desc < 0)
    {
      if (! noerror) {
	char *name = alloca (strlen (s->filename) + 100);
	sprintf (name, "%s:%d", s->filename, line);
        print_sys_errmsg (name, errno);
      }
      return;
    }

  if (s->line_charpos == 0)
    find_source_lines (s, desc);

  if (line < 1 || line > s->nlines)
    {
      close (desc);
      error ("Line number %d out of range; %s has %d lines.",
	     line, s->filename, s->nlines);
    }

  if (lseek (desc, s->line_charpos[line - 1], 0) < 0)
    {
      close (desc);
      perror_with_name (s->filename);
    }

  stream = fdopen (desc, "r");
  clearerr (stream);

  while (nlines-- > 0)
    {
      c = fgetc (stream);
      if (c == EOF) break;
      last_line_listed = current_source_line;
      printf_filtered ("%d\t", current_source_line++);
      do
	{
	  if (c < 040 && c != '\t' && c != '\n')
	      printf_filtered ("^%c", c + 0100);
	  else if (c == 0177)
	    printf_filtered ("^?");
	  else
	    printf_filtered ("%c", c);
	} while (c != '\n' && (c = fgetc (stream)) >= 0);
    }

  fclose (stream);
}



/* 
  C++
  Print a list of files and line numbers which a user may choose from
  in order to list a function which was specified ambiguously
  (as with `list classname::overloadedfuncname', for example).
  The vector in SALS provides the filenames and line numbers.
  */
static void
ambiguous_line_spec (sals)
     struct symtabs_and_lines *sals;
{
  int i;

  for (i = 0; i < sals->nelts; ++i)
    printf("file: \"%s\", line number: %d\n",
	   sals->sals[i].symtab->filename, sals->sals[i].line);
}


static void
list_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  struct symtabs_and_lines sals, sals_end;
  struct symtab_and_line sal, sal_end;
  struct symbol *sym;
  char *arg1;
  int no_end = 1;
  int dummy_end = 0;
  int dummy_beg = 0;
  int linenum_beg = 0;
  char *p;

  if (symtab_list == 0 && partial_symtab_list == 0)
    error ("No symbol table is loaded.  Use the \"symbol-file\" command.");

  /* Pull in a current source symtab if necessary */
  if (current_source_symtab == 0 &&
      (arg == 0 || arg[0] == '+' || arg[0] == '-'))
    select_source_symtab (0);

  /* "l" or "l +" lists next ten lines.  */

  if (arg == 0 || !strcmp (arg, "+"))
    {
      if (current_source_symtab == 0)
	error ("No default source file yet.  Do \"help list\".");
      print_source_lines (current_source_symtab, current_source_line,
			  current_source_line + lines_to_list (), 0);
      return;
    }

  /* "l -" lists previous ten lines, the ones before the ten just listed.  */
  if (!strcmp (arg, "-"))
    {
      if (current_source_symtab == 0)
	error ("No default source file yet.  Do \"help list\".");
      print_source_lines (current_source_symtab,
			  max (first_line_listed - lines_to_list (), 1),
			  first_line_listed, 0);
      return;
    }

  /* Now if there is only one argument, decode it in SAL
     and set NO_END.
     If there are two arguments, decode them in SAL and SAL_END
     and clear NO_END; however, if one of the arguments is blank,
     set DUMMY_BEG or DUMMY_END to record that fact.  */

  arg1 = arg;
  if (*arg1 == ',')
    dummy_beg = 1;
  else
    {
      sals = decode_line_1 (&arg1, 0, 0, 0);

      if (! sals.nelts) return;  /*  C++  */
      if (sals.nelts > 1)
	{
	  ambiguous_line_spec (&sals);
	  free (sals.sals);
	  return;
	}

      sal = sals.sals[0];
      free (sals.sals);
    }

  /* Record whether the BEG arg is all digits.  */

  for (p = arg; p != arg1 && *p >= '0' && *p <= '9'; p++);
  linenum_beg = (p == arg1);

  while (*arg1 == ' ' || *arg1 == '\t')
    arg1++;
  if (*arg1 == ',')
    {
      no_end = 0;
      arg1++;
      while (*arg1 == ' ' || *arg1 == '\t')
	arg1++;
      if (*arg1 == 0)
	dummy_end = 1;
      else
	{
	  if (dummy_beg)
	    sals_end = decode_line_1 (&arg1, 0, 0, 0);
	  else
	    sals_end = decode_line_1 (&arg1, 0, sal.symtab, sal.line);
	  if (sals_end.nelts == 0) 
	    return;
	  if (sals_end.nelts > 1)
	    {
	      ambiguous_line_spec (&sals_end);
	      free (sals_end.sals);
	      return;
	    }
	  sal_end = sals_end.sals[0];
	  free (sals_end.sals);
	}
    }

  if (*arg1)
    error ("Junk at end of line specification.");

  if (!no_end && !dummy_beg && !dummy_end
      && sal.symtab != sal_end.symtab)
    error ("Specified start and end are in different files.");
  if (dummy_beg && dummy_end)
    error ("Two empty args do not say what lines to list.");
 
  /* if line was specified by address,
     first print exactly which line, and which file.
     In this case, sal.symtab == 0 means address is outside
     of all known source files, not that user failed to give a filename.  */
  if (*arg == '*')
    {
      if (sal.symtab == 0)
	error ("No source file for address 0x%x.", sal.pc);
      sym = find_pc_function (sal.pc);
      if (sym)
	printf ("0x%x is in %s (%s, line %d).\n",
		sal.pc, SYMBOL_NAME (sym), sal.symtab->filename, sal.line);
      else
	printf ("0x%x is in %s, line %d.\n",
		sal.pc, sal.symtab->filename, sal.line);
    }

  /* If line was not specified by just a line number,
     and it does not imply a symtab, it must be an undebuggable symbol
     which means no source code.  */

  if (! linenum_beg && sal.symtab == 0)
    error ("No line number known for %s.", arg);

  /* If this command is repeated with RET,
     turn it into the no-arg variant.  */

  if (from_tty)
    *arg = 0;

  if (dummy_beg && sal_end.symtab == 0)
    error ("No default source file yet.  Do \"help list\".");
  if (dummy_beg)
    print_source_lines (sal_end.symtab,
			max (sal_end.line - (lines_to_list () - 1), 1),
			sal_end.line + 1, 0);
  else if (sal.symtab == 0)
    error ("No default source file yet.  Do \"help list\".");
  else if (no_end)
    print_source_lines (sal.symtab,
			max (sal.line - (lines_to_list () / 2), 1),
			sal.line + 5, 0);
  else
    print_source_lines (sal.symtab, sal.line,
			(dummy_end
			 ? sal.line + lines_to_list ()
			 : sal_end.line + 1),
			0);
}

/* Print info on range of pc's in a specified line.  */

static void
line_info (arg, from_tty)
     char *arg;
     int from_tty;
{
  struct symtabs_and_lines sals;
  struct symtab_and_line sal;
  CORE_ADDR start_pc, end_pc;
  int i;

  if (arg == 0)
    {
      sal.symtab = current_source_symtab;
      sal.line = last_line_listed;
      sals.nelts = 1;
      sals.sals = (struct symtab_and_line *)
	xmalloc (sizeof (struct symtab_and_line));
      sals.sals[0] = sal;
    }
  else
    {
      sals = decode_line_spec_1 (arg, 0);
      
      /* If this command is repeated with RET,
	 turn it into the no-arg variant.  */
      if (from_tty)
	*arg = 0;
    }

  /* C++  More than one line may have been specified, as when the user
     specifies an overloaded function name. Print info on them all. */
  for (i = 0; i < sals.nelts; i++)
    {
      sal = sals.sals[i];
      
      if (sal.symtab == 0)
	error ("No source file specified.");

      if (sal.line > 0
	  && find_line_pc_range (sal.symtab, sal.line, &start_pc, &end_pc))
	{
	  if (start_pc == end_pc)
	    printf ("Line %d of \"%s\" is at pc 0x%x but contains no code.\n",
		    sal.line, sal.symtab->filename, start_pc);
	  else
	    printf ("Line %d of \"%s\" starts at pc 0x%x and ends at 0x%x.\n",
		    sal.line, sal.symtab->filename, start_pc, end_pc);
	  /* x/i should display this line's code.  */
	  set_next_address (start_pc);
	  /* Repeating "info line" should do the following line.  */
	  last_line_listed = sal.line + 1;
	}
      else
	printf ("Line number %d is out of range for \"%s\".\n",
		sal.line, sal.symtab->filename);
    }
}

/* Commands to search the source file for a regexp.  */

static void
forward_search_command (regex, from_tty)
     char *regex;
     int from_tty;
{
  register int c;
  register int desc;
  register FILE *stream;
  int line = last_line_listed + 1;
  char *msg;

  msg = (char *) re_comp (regex);
  if (msg)
    error (msg);

  if (current_source_symtab == 0)
    select_source_symtab (0);

  /* Search from last_line_listed+1 in current_source_symtab */

  desc = open_source_file (current_source_symtab);
  if (desc < 0)
    perror_with_name (current_source_symtab->filename);

  if (current_source_symtab->line_charpos == 0)
    find_source_lines (current_source_symtab, desc);

  if (line < 1 || line > current_source_symtab->nlines)
    {
      close (desc);
      error ("Expression not found");
    }

  if (lseek (desc, current_source_symtab->line_charpos[line - 1], 0) < 0)
    {
      close (desc);
      perror_with_name (current_source_symtab->filename);
    }

  stream = fdopen (desc, "r");
  clearerr (stream);
  while (1) {
    char buf[4096];		/* Should be reasonable??? */
    register char *p = buf;

    c = fgetc (stream);
    if (c == EOF)
      break;
    do {
      *p++ = c;
    } while (c != '\n' && (c = fgetc (stream)) >= 0);

    /* we now have a source line in buf, null terminate and match */
    *p = 0;
    if (re_exec (buf) > 0)
      {
	/* Match! */
	fclose (stream);
	print_source_lines (current_source_symtab,
			   line, line+1, 0);
	current_source_line = max (line - lines_to_list () / 2, 1);
	return;
      }
    line++;
  }

  printf ("Expression not found\n");
  fclose (stream);
}

static void
reverse_search_command (regex, from_tty)
     char *regex;
     int from_tty;
{
  register int c;
  register int desc;
  register FILE *stream;
  int line = last_line_listed - 1;
  char *msg;

  msg = (char *) re_comp (regex);
  if (msg)
    error (msg);

  if (current_source_symtab == 0)
    select_source_symtab (0);

  /* Search from last_line_listed-1 in current_source_symtab */

  desc = open_source_file (current_source_symtab);
  if (desc < 0)
    perror_with_name (current_source_symtab->filename);

  if (current_source_symtab->line_charpos == 0)
    find_source_lines (current_source_symtab, desc);

  if (line < 1 || line > current_source_symtab->nlines)
    {
      close (desc);
      error ("Expression not found");
    }

  if (lseek (desc, current_source_symtab->line_charpos[line - 1], 0) < 0)
    {
      close (desc);
      perror_with_name (current_source_symtab->filename);
    }

  stream = fdopen (desc, "r");
  clearerr (stream);
  while (line > 1)
    {
      char buf[4096];		/* Should be reasonable??? */
      register char *p = buf;

      c = fgetc (stream);
      if (c == EOF)
	break;
      do {
	*p++ = c;
      } while (c != '\n' && (c = fgetc (stream)) >= 0);

      /* We now have a source line in buf; null terminate and match.  */
      *p = 0;
      if (re_exec (buf) > 0)
	{
	  /* Match! */
	  fclose (stream);
	  print_source_lines (current_source_symtab,
			      line, line+1, 0);
	  current_source_line = max (line - lines_to_list () / 2, 1);
	  return;
	}
      line--;
      if (fseek (stream, current_source_symtab->line_charpos[line - 1], 0) < 0)
	{
	  fclose (stream);
	  perror_with_name (current_source_symtab->filename);
	}
    }

  printf ("Expression not found\n");
  fclose (stream);
  return;
}

void
_initialize_source ()
{
  current_source_symtab = 0;
  init_source_path ();

  add_com ("directory", class_files, directory_command,
	   "Add directory DIR to beginning of search path for source files.\n\
Forget cached info on source file locations and line positions.\n\
DIR can also be $cwd for the current working directory, or $cdir for the\n\
directory in which the source file was compiled into object code.\n\
With no argument, reset the search path to $cdir:$cwd, the default.");

  add_info ("directories", directories_info,
	    "Current search path for finding source files.\n\
$cwd in the path means the current working directory.\n\
$cdir in the path means the compilation directory of the source file.");

  add_info ("source", source_info,
	    "Information about the current source file.");

  add_info ("line", line_info,
	    "Core addresses of the code for a source line.\n\
Line can be specified as\n\
  LINENUM, to list around that line in current file,\n\
  FILE:LINENUM, to list around that line in that file,\n\
  FUNCTION, to list around beginning of that function,\n\
  FILE:FUNCTION, to distinguish among like-named static functions.\n\
Default is to describe the last source line that was listed.\n\n\
This sets the default address for \"x\" to the line's first instruction\n\
so that \"x/i\" suffices to start examining the machine code.\n\
The address is also stored as the value of \"$_\".");

  add_com ("forward-search", class_files, forward_search_command,
	   "Search for regular expression (see regex(3)) from last line listed.");
  add_com_alias ("search", "forward-search", class_files, 0);

  add_com ("reverse-search", class_files, reverse_search_command,
	   "Search backward for regular expression (see regex(3)) from last line listed.");

  add_com ("list", class_files, list_command,
	   "List specified function or line.\n\
With no argument, lists ten more lines after or around previous listing.\n\
\"list -\" lists the ten lines before a previous ten-line listing.\n\
One argument specifies a line, and ten lines are listed around that line.\n\
Two arguments with comma between specify starting and ending lines to list.\n\
Lines can be specified in these ways:\n\
  LINENUM, to list around that line in current file,\n\
  FILE:LINENUM, to list around that line in that file,\n\
  FUNCTION, to list around beginning of that function,\n\
  FILE:FUNCTION, to distinguish among like-named static functions.\n\
  *ADDRESS, to list around the line containing that address.\n\
With two args if one is empty it stands for ten lines away from the other arg.");
  add_com_alias ("l", "list", class_files, 0);
}