aboutsummaryrefslogtreecommitdiff
path: root/gdb/solib.c
blob: 5fdb9a1d14857937923a44eef9557740d62ade89 (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
/* Handle shared libraries for GDB, the GNU Debugger.
   Copyright 1990, 91, 92, 93, 94, 95, 96, 98, 1999, 2000, 2001
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program 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 2 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"

#include <sys/types.h>
#include <fcntl.h>
#include "gdb_string.h"
#include "symtab.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdbcore.h"
#include "command.h"
#include "target.h"
#include "frame.h"
#include "gdb_regex.h"
#include "inferior.h"
#include "environ.h"
#include "language.h"
#include "gdbcmd.h"
#include "completer.h"

#include "solist.h"

/* external data declarations */

/* FIXME: gdbarch needs to control this variable */
struct target_so_ops *current_target_so_ops;

/* local data declarations */

static struct so_list *so_list_head;	/* List of known shared objects */

static int solib_cleanup_queued = 0;	/* make_run_cleanup called */

/* Local function prototypes */

static void do_clear_solib (PTR);

/* If non-zero, this is a prefix that will be added to the front of the name
   shared libraries with an absolute filename for loading.  */
static char *solib_absolute_prefix = NULL;

/* If non-empty, this is a search path for loading non-absolute shared library
   symbol files.  This takes precedence over the environment variables PATH
   and LD_LIBRARY_PATH.  */
static char *solib_search_path = NULL;

/*

   GLOBAL FUNCTION

   solib_open -- Find a shared library file and open it.

   SYNOPSIS

   int solib_open (char *in_patname, char **found_pathname);

   DESCRIPTION

   Global variable SOLIB_ABSOLUTE_PREFIX is used as a prefix directory
   to search for shared libraries if they have an absolute path.

   Global variable SOLIB_SEARCH_PATH is used as a prefix directory
   (or set of directories, as in LD_LIBRARY_PATH) to search for all
   shared libraries if not found in SOLIB_ABSOLUTE_PREFIX.

   Search order:
   * If path is absolute, look in SOLIB_ABSOLUTE_PREFIX.
   * If path is absolute or relative, look for it literally (unmodified).
   * Look in SOLIB_SEARCH_PATH.
   * Look in inferior's $PATH.
   * Look in inferior's $LD_LIBRARY_PATH.

   RETURNS

   file handle for opened solib, or -1 for failure.  */

int
solib_open (char *in_pathname, char **found_pathname)
{
  int found_file = -1;
  char *temp_pathname = NULL;

  if (strchr (in_pathname, SLASH_CHAR))
    {
      if (! ROOTED_P (in_pathname) || solib_absolute_prefix == NULL)
        temp_pathname = in_pathname;
      else
	{
	  int prefix_len = strlen (solib_absolute_prefix);

	  /* Remove trailing slashes from absolute prefix.  */
	  while (prefix_len > 0
		 && SLASH_P (solib_absolute_prefix[prefix_len - 1]))
	    prefix_len--;

	  /* Cat the prefixed pathname together.  */
	  temp_pathname = alloca (prefix_len + strlen (in_pathname) + 1);
	  strncpy (temp_pathname, solib_absolute_prefix, prefix_len);
	  temp_pathname[prefix_len] = '\0';
	  strcat (temp_pathname, in_pathname);
	}

      /* Now see if we can open it.  */
      found_file = open (temp_pathname, O_RDONLY, 0);
    }

  /* If not found, next search the solib_search_path (if any).  */
  if (found_file < 0 && solib_search_path != NULL)
    found_file = openp (solib_search_path,
			1, in_pathname, O_RDONLY, 0, &temp_pathname);

  /* If not found, next search the inferior's $PATH environment variable. */
  if (found_file < 0 && solib_search_path != NULL)
    found_file = openp (get_in_environ (inferior_environ, "PATH"),
			1, in_pathname, O_RDONLY, 0, &temp_pathname);

  /* If not found, next search the inferior's $LD_LIBRARY_PATH 
     environment variable. */
  if (found_file < 0 && solib_search_path != NULL)
    found_file = openp (get_in_environ (inferior_environ, "LD_LIBRARY_PATH"),
			1, in_pathname, O_RDONLY, 0, &temp_pathname);

  /* Done.  If not found, tough luck.  Return found_file and 
     (optionally) found_pathname.  */
  if (found_pathname != NULL && temp_pathname != NULL)
    *found_pathname = xstrdup (temp_pathname);
  return found_file;
}


/*

   LOCAL FUNCTION

   solib_map_sections -- open bfd and build sections for shared lib

   SYNOPSIS

   static int solib_map_sections (struct so_list *so)

   DESCRIPTION

   Given a pointer to one of the shared objects in our list
   of mapped objects, use the recorded name to open a bfd
   descriptor for the object, build a section table, and then
   relocate all the section addresses by the base address at
   which the shared object was mapped.

   FIXMES

   In most (all?) cases the shared object file name recorded in the
   dynamic linkage tables will be a fully qualified pathname.  For
   cases where it isn't, do we really mimic the systems search
   mechanism correctly in the below code (particularly the tilde
   expansion stuff?).
 */

static int
solib_map_sections (PTR arg)
{
  struct so_list *so = (struct so_list *) arg;	/* catch_errors bogon */
  char *filename;
  char *scratch_pathname;
  int scratch_chan;
  struct section_table *p;
  struct cleanup *old_chain;
  bfd *abfd;

  filename = tilde_expand (so->so_name);

  old_chain = make_cleanup (xfree, filename);
  scratch_chan = solib_open (filename, &scratch_pathname);

  if (scratch_chan < 0)
    {
      perror_with_name (filename);
    }

  /* Leave scratch_pathname allocated.  abfd->name will point to it.  */
  abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
  if (!abfd)
    {
      close (scratch_chan);
      error ("Could not open `%s' as an executable file: %s",
	     scratch_pathname, bfd_errmsg (bfd_get_error ()));
    }

  /* Leave bfd open, core_xfer_memory and "info files" need it.  */
  so->abfd = abfd;
  abfd->cacheable = true;

  /* copy full path name into so_name, so that later symbol_file_add
     can find it */
  if (strlen (scratch_pathname) >= SO_NAME_MAX_PATH_SIZE)
    error ("Full path name length of shared library exceeds SO_NAME_MAX_PATH_SIZE in so_list structure.");
  strcpy (so->so_name, scratch_pathname);

  if (!bfd_check_format (abfd, bfd_object))
    {
      error ("\"%s\": not in executable format: %s.",
	     scratch_pathname, bfd_errmsg (bfd_get_error ()));
    }
  if (build_section_table (abfd, &so->sections, &so->sections_end))
    {
      error ("Can't find the file sections in `%s': %s",
	     bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
    }

  for (p = so->sections; p < so->sections_end; p++)
    {
      /* Relocate the section binding addresses as recorded in the shared
         object's file by the base address to which the object was actually
         mapped. */
      TARGET_SO_RELOCATE_SECTION_ADDRESSES (so, p);
      if (STREQ (p->the_bfd_section->name, ".text"))
	{
	  so->textsection = p;
	}
    }

  /* Free the file names, close the file now.  */
  do_cleanups (old_chain);

  return (1);
}

/* LOCAL FUNCTION

   free_so --- free a `struct so_list' object

   SYNOPSIS

   void free_so (struct so_list *so)

   DESCRIPTION

   Free the storage associated with the `struct so_list' object SO.
   If we have opened a BFD for SO, close it.  

   The caller is responsible for removing SO from whatever list it is
   a member of.  If we have placed SO's sections in some target's
   section table, the caller is responsible for removing them.

   This function doesn't mess with objfiles at all.  If there is an
   objfile associated with SO that needs to be removed, the caller is
   responsible for taking care of that.  */

void
free_so (struct so_list *so)
{
  char *bfd_filename = 0;

  if (so->sections)
    xfree (so->sections);
      
  if (so->abfd)
    {
      bfd_filename = bfd_get_filename (so->abfd);
      if (! bfd_close (so->abfd))
	warning ("cannot close \"%s\": %s",
		 bfd_filename, bfd_errmsg (bfd_get_error ()));
    }

  if (bfd_filename)
    xfree (bfd_filename);

  TARGET_SO_FREE_SO (so);

  xfree (so);
}


/* A small stub to get us past the arg-passing pinhole of catch_errors.  */

static int
symbol_add_stub (PTR arg)
{
  register struct so_list *so = (struct so_list *) arg;  /* catch_errs bogon */
  struct section_addr_info *sap;

  /* Have we already loaded this shared object?  */
  ALL_OBJFILES (so->objfile)
    {
      if (strcmp (so->objfile->name, so->so_name) == 0)
	return 1;
    }

  sap = build_section_addr_info_from_section_table (so->sections,
                                                    so->sections_end);

  so->objfile = symbol_file_add (so->so_name, so->from_tty,
				 sap, 0, OBJF_SHARED);
  free_section_addr_info (sap);

  return (1);
}


/* LOCAL FUNCTION

   update_solib_list --- synchronize GDB's shared object list with inferior's

   SYNOPSIS

   void update_solib_list (int from_tty, struct target_ops *TARGET)

   Extract the list of currently loaded shared objects from the
   inferior, and compare it with the list of shared objects currently
   in GDB's so_list_head list.  Edit so_list_head to bring it in sync
   with the inferior's new list.

   If we notice that the inferior has unloaded some shared objects,
   free any symbolic info GDB had read about those shared objects.

   Don't load symbolic info for any new shared objects; just add them
   to the list, and leave their symbols_loaded flag clear.

   If FROM_TTY is non-null, feel free to print messages about what
   we're doing.

   If TARGET is non-null, add the sections of all new shared objects
   to TARGET's section table.  Note that this doesn't remove any
   sections for shared objects that have been unloaded, and it
   doesn't check to see if the new shared objects are already present in
   the section table.  But we only use this for core files and
   processes we've just attached to, so that's okay.  */

void
update_solib_list (int from_tty, struct target_ops *target)
{
  struct so_list *inferior = TARGET_SO_CURRENT_SOS ();
  struct so_list *gdb, **gdb_link;

  /* If we are attaching to a running process for which we 
     have not opened a symbol file, we may be able to get its 
     symbols now!  */
  if (attach_flag &&
      symfile_objfile == NULL)
    catch_errors (TARGET_SO_OPEN_SYMBOL_FILE_OBJECT, (PTR) &from_tty, 
		  "Error reading attached process's symbol file.\n",
		  RETURN_MASK_ALL);

  /* Since this function might actually add some elements to the
     so_list_head list, arrange for it to be cleaned up when
     appropriate.  */
  if (!solib_cleanup_queued)
    {
      make_run_cleanup (do_clear_solib, NULL);
      solib_cleanup_queued = 1;
    }

  /* GDB and the inferior's dynamic linker each maintain their own
     list of currently loaded shared objects; we want to bring the
     former in sync with the latter.  Scan both lists, seeing which
     shared objects appear where.  There are three cases:

     - A shared object appears on both lists.  This means that GDB
     knows about it already, and it's still loaded in the inferior.
     Nothing needs to happen.

     - A shared object appears only on GDB's list.  This means that
     the inferior has unloaded it.  We should remove the shared
     object from GDB's tables.

     - A shared object appears only on the inferior's list.  This
     means that it's just been loaded.  We should add it to GDB's
     tables.

     So we walk GDB's list, checking each entry to see if it appears
     in the inferior's list too.  If it does, no action is needed, and
     we remove it from the inferior's list.  If it doesn't, the
     inferior has unloaded it, and we remove it from GDB's list.  By
     the time we're done walking GDB's list, the inferior's list
     contains only the new shared objects, which we then add.  */

  gdb = so_list_head;
  gdb_link = &so_list_head;
  while (gdb)
    {
      struct so_list *i = inferior;
      struct so_list **i_link = &inferior;

      /* Check to see whether the shared object *gdb also appears in
	 the inferior's current list.  */
      while (i)
	{
	  if (! strcmp (gdb->so_original_name, i->so_original_name))
	    break;

	  i_link = &i->next;
	  i = *i_link;
	}

      /* If the shared object appears on the inferior's list too, then
         it's still loaded, so we don't need to do anything.  Delete
         it from the inferior's list, and leave it on GDB's list.  */
      if (i)
	{
	  *i_link = i->next;
	  free_so (i);
	  gdb_link = &gdb->next;
	  gdb = *gdb_link;
	}

      /* If it's not on the inferior's list, remove it from GDB's tables.  */
      else
	{
	  *gdb_link = gdb->next;

	  /* Unless the user loaded it explicitly, free SO's objfile.  */
	  if (gdb->objfile && ! (gdb->objfile->flags & OBJF_USERLOADED))
	    free_objfile (gdb->objfile);

	  /* Some targets' section tables might be referring to
	     sections from so->abfd; remove them.  */
	  remove_target_sections (gdb->abfd);

	  free_so (gdb);
	  gdb = *gdb_link;
	}
    }

  /* Now the inferior's list contains only shared objects that don't
     appear in GDB's list --- those that are newly loaded.  Add them
     to GDB's shared object list.  */
  if (inferior)
    {
      struct so_list *i;

      /* Add the new shared objects to GDB's list.  */
      *gdb_link = inferior;

      /* Fill in the rest of each of the `struct so_list' nodes.  */
      for (i = inferior; i; i = i->next)
	{
	  i->from_tty = from_tty;

	  /* Fill in the rest of the `struct so_list' node.  */
	  catch_errors (solib_map_sections, i,
			"Error while mapping shared library sections:\n",
			RETURN_MASK_ALL);
	}

      /* If requested, add the shared objects' sections to the the
	 TARGET's section table.  */
      if (target)
	{
	  int new_sections;

	  /* Figure out how many sections we'll need to add in total.  */
	  new_sections = 0;
	  for (i = inferior; i; i = i->next)
	    new_sections += (i->sections_end - i->sections);

	  if (new_sections > 0)
	    {
	      int space = target_resize_to_sections (target, new_sections);

	      for (i = inferior; i; i = i->next)
		{
		  int count = (i->sections_end - i->sections);
		  memcpy (target->to_sections + space,
			  i->sections,
			  count * sizeof (i->sections[0]));
		  space += count;
		}
	    }
	}
    }
}


/* GLOBAL FUNCTION

   solib_add -- read in symbol info for newly added shared libraries

   SYNOPSIS

   void solib_add (char *pattern, int from_tty, struct target_ops *TARGET)

   DESCRIPTION

   Read in symbolic information for any shared objects whose names
   match PATTERN.  (If we've already read a shared object's symbol
   info, leave it alone.)  If PATTERN is zero, read them all.

   FROM_TTY and TARGET are as described for update_solib_list, above.  */

void
solib_add (char *pattern, int from_tty, struct target_ops *target)
{
  struct so_list *gdb;

  if (pattern)
    {
      char *re_err = re_comp (pattern);

      if (re_err)
	error ("Invalid regexp: %s", re_err);
    }

  update_solib_list (from_tty, target);

  /* Walk the list of currently loaded shared libraries, and read
     symbols for any that match the pattern --- or any whose symbols
     aren't already loaded, if no pattern was given.  */
  {
    int any_matches = 0;
    int loaded_any_symbols = 0;

    for (gdb = so_list_head; gdb; gdb = gdb->next)
      if (! pattern || re_exec (gdb->so_name))
	{
	  any_matches = 1;

	  if (gdb->symbols_loaded)
	    {
	      if (from_tty)
		printf_unfiltered ("Symbols already loaded for %s\n",
				   gdb->so_name);
	    }
	  else
	    {
	      if (catch_errors
		  (symbol_add_stub, gdb,
		   "Error while reading shared library symbols:\n",
		   RETURN_MASK_ALL))
		{
		  if (from_tty)
		    printf_unfiltered ("Loaded symbols for %s\n",
				       gdb->so_name);
		  gdb->symbols_loaded = 1;
		  loaded_any_symbols = 1;
		}
	    }
	}

    if (from_tty && pattern && ! any_matches)
      printf_unfiltered
	("No loaded shared libraries match the pattern `%s'.\n", pattern);

    if (loaded_any_symbols)
      {
	/* Getting new symbols may change our opinion about what is
	   frameless.  */
	reinit_frame_cache ();

	TARGET_SO_SPECIAL_SYMBOL_HANDLING ();
      }
  }
}


/*

   LOCAL FUNCTION

   info_sharedlibrary_command -- code for "info sharedlibrary"

   SYNOPSIS

   static void info_sharedlibrary_command ()

   DESCRIPTION

   Walk through the shared library list and print information
   about each attached library.
 */

static void
info_sharedlibrary_command (char *ignore, int from_tty)
{
  register struct so_list *so = NULL;	/* link map state variable */
  int header_done = 0;
  int addr_width;
  char *addr_fmt;
  int arch_size;

  if (exec_bfd == NULL)
    {
      printf_unfiltered ("No executable file.\n");
      return;
    }

  arch_size = bfd_get_arch_size (exec_bfd);
  /* Default to 32-bit in case of failure (non-elf). */
  if (arch_size == 32 || arch_size == -1)
    {
      addr_width = 8 + 4;
      addr_fmt = "08l";
    }
  else if (arch_size == 64)
    {
      addr_width = 16 + 4;
      addr_fmt = "016l";
    }
  else
    {
      internal_error (__FILE__, __LINE__,
		      "bfd_get_arch_size() returned unknown size %d",
		      arch_size);
    }

  update_solib_list (from_tty, 0);

  for (so = so_list_head; so; so = so->next)
    {
      if (so->so_name[0])
	{
	  if (!header_done)
	    {
	      printf_unfiltered ("%-*s%-*s%-12s%s\n", addr_width, "From",
				 addr_width, "To", "Syms Read",
				 "Shared Object Library");
	      header_done++;
	    }

	  printf_unfiltered ("%-*s", addr_width,
			     so->textsection != NULL 
			       ? local_hex_string_custom (
			           (unsigned long) so->textsection->addr,
	                           addr_fmt)
			       : "");
	  printf_unfiltered ("%-*s", addr_width,
			     so->textsection != NULL 
			       ? local_hex_string_custom (
			           (unsigned long) so->textsection->endaddr,
	                           addr_fmt)
			       : "");
	  printf_unfiltered ("%-12s", so->symbols_loaded ? "Yes" : "No");
	  printf_unfiltered ("%s\n", so->so_name);
	}
    }
  if (so_list_head == NULL)
    {
      printf_unfiltered ("No shared libraries loaded at this time.\n");
    }
}

/*

   GLOBAL FUNCTION

   solib_address -- check to see if an address is in a shared lib

   SYNOPSIS

   char * solib_address (CORE_ADDR address)

   DESCRIPTION

   Provides a hook for other gdb routines to discover whether or
   not a particular address is within the mapped address space of
   a shared library.

   For example, this routine is called at one point to disable
   breakpoints which are in shared libraries that are not currently
   mapped in.
 */

char *
solib_address (CORE_ADDR address)
{
  register struct so_list *so = 0;	/* link map state variable */

  for (so = so_list_head; so; so = so->next)
    {
      struct section_table *p;

      for (p = so->sections; p < so->sections_end; p++)
	{
	  if (p->addr <= address && address < p->endaddr)
	    return (so->so_name);
	}
    }

  return (0);
}

/* Called by free_all_symtabs */

void
clear_solib (void)
{
  /* This function is expected to handle ELF shared libraries.  It is
     also used on Solaris, which can run either ELF or a.out binaries
     (for compatibility with SunOS 4), both of which can use shared
     libraries.  So we don't know whether we have an ELF executable or
     an a.out executable until the user chooses an executable file.

     ELF shared libraries don't get mapped into the address space
     until after the program starts, so we'd better not try to insert
     breakpoints in them immediately.  We have to wait until the
     dynamic linker has loaded them; we'll hit a bp_shlib_event
     breakpoint (look for calls to create_solib_event_breakpoint) when
     it's ready.

     SunOS shared libraries seem to be different --- they're present
     as soon as the process begins execution, so there's no need to
     put off inserting breakpoints.  There's also nowhere to put a
     bp_shlib_event breakpoint, so if we put it off, we'll never get
     around to it.

     So: disable breakpoints only if we're using ELF shared libs.  */
  if (exec_bfd != NULL
      && bfd_get_flavour (exec_bfd) != bfd_target_aout_flavour)
    disable_breakpoints_in_shlibs (1);

  while (so_list_head)
    {
      struct so_list *so = so_list_head;
      so_list_head = so->next;
      free_so (so);
    }

  TARGET_SO_CLEAR_SOLIB ();
}

static void
do_clear_solib (PTR dummy)
{
  solib_cleanup_queued = 0;
  clear_solib ();
}

/* GLOBAL FUNCTION

   solib_create_inferior_hook -- shared library startup support

   SYNOPSIS

   void solib_create_inferior_hook()

   DESCRIPTION

   When gdb starts up the inferior, it nurses it along (through the
   shell) until it is ready to execute it's first instruction.  At this
   point, this function gets called via expansion of the macro
   SOLIB_CREATE_INFERIOR_HOOK.  */

void
solib_create_inferior_hook (void)
{
  TARGET_SO_SOLIB_CREATE_INFERIOR_HOOK ();
}


/*

   LOCAL FUNCTION

   sharedlibrary_command -- handle command to explicitly add library

   SYNOPSIS

   static void sharedlibrary_command (char *args, int from_tty)

   DESCRIPTION

 */

static void
sharedlibrary_command (char *args, int from_tty)
{
  dont_repeat ();
  solib_add (args, from_tty, (struct target_ops *) 0);
}


void
_initialize_solib (void)
{
  struct cmd_list_element *c;

  add_com ("sharedlibrary", class_files, sharedlibrary_command,
	   "Load shared object library symbols for files matching REGEXP.");
  add_info ("sharedlibrary", info_sharedlibrary_command,
	    "Status of loaded shared object libraries.");

  add_show_from_set
    (add_set_cmd ("auto-solib-add", class_support, var_zinteger,
		  (char *) &auto_solib_add,
		  "Set autoloading of shared library symbols.\n\
If nonzero, symbols from all shared object libraries will be loaded\n\
automatically when the inferior begins execution or when the dynamic linker\n\
informs gdb that a new library has been loaded.  Otherwise, symbols\n\
must be loaded manually, using `sharedlibrary'.",
		  &setlist),
     &showlist);

  c = add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
		   (char *) &solib_absolute_prefix,
		   "Set prefix for loading absolute shared library symbol files.\n\
For other (relative) files, you can add values using `set solib-search-path'.",
		   &setlist);
  add_show_from_set (c, &showlist);
  c->completer = filename_completer;

  c = add_set_cmd ("solib-search-path", class_support, var_string,
		   (char *) &solib_search_path,
		   "Set the search path for loading non-absolute shared library symbol files.\n\
This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
		   &setlist);
  add_show_from_set (c, &showlist);
  c->completer = filename_completer;
}