1/* Handle shared libraries for GDB, the GNU Debugger.
2
3   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4   1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5
6   This file is part of GDB.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 2 of the License, or
11   (at your option) any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with this program; if not, write to the Free Software
20   Foundation, Inc., 59 Temple Place - Suite 330,
21   Boston, MA 02111-1307, USA.  */
22
23#include "defs.h"
24
25#include <sys/types.h>
26#include <fcntl.h>
27#include "gdb_string.h"
28#include "symtab.h"
29#include "bfd.h"
30#include "symfile.h"
31#include "objfiles.h"
32#include "gdbcore.h"
33#include "command.h"
34#include "target.h"
35#include "frame.h"
36#include "gdb_regex.h"
37#include "inferior.h"
38#include "environ.h"
39#include "language.h"
40#include "gdbcmd.h"
41#include "completer.h"
42#include "filenames.h"		/* for DOSish file names */
43#include "exec.h"
44#include "solist.h"
45#include "observer.h"
46#include "readline/readline.h"
47
48/* external data declarations */
49
50/* FIXME: gdbarch needs to control this variable */
51struct target_so_ops *current_target_so_ops;
52
53/* local data declarations */
54
55static struct so_list *so_list_head;	/* List of known shared objects */
56
57static int solib_cleanup_queued = 0;	/* make_run_cleanup called */
58
59/* Local function prototypes */
60
61static void do_clear_solib (void *);
62
63/* If non-zero, this is a prefix that will be added to the front of the name
64   shared libraries with an absolute filename for loading.  */
65static char *solib_absolute_prefix = NULL;
66
67/* If non-empty, this is a search path for loading non-absolute shared library
68   symbol files.  This takes precedence over the environment variables PATH
69   and LD_LIBRARY_PATH.  */
70static char *solib_search_path = NULL;
71
72/*
73
74   GLOBAL FUNCTION
75
76   solib_open -- Find a shared library file and open it.
77
78   SYNOPSIS
79
80   int solib_open (char *in_patname, char **found_pathname);
81
82   DESCRIPTION
83
84   Global variable SOLIB_ABSOLUTE_PREFIX is used as a prefix directory
85   to search for shared libraries if they have an absolute path.
86
87   Global variable SOLIB_SEARCH_PATH is used as a prefix directory
88   (or set of directories, as in LD_LIBRARY_PATH) to search for all
89   shared libraries if not found in SOLIB_ABSOLUTE_PREFIX.
90
91   Search algorithm:
92   * If there is a solib_absolute_prefix and path is absolute:
93   *   Search for solib_absolute_prefix/path.
94   * else
95   *   Look for it literally (unmodified).
96   * Look in SOLIB_SEARCH_PATH.
97   * If available, use target defined search function.
98   * If solib_absolute_prefix is NOT set, perform the following two searches:
99   *   Look in inferior's $PATH.
100   *   Look in inferior's $LD_LIBRARY_PATH.
101   *
102   * The last check avoids doing this search when targetting remote
103   * machines since solib_absolute_prefix will almost always be set.
104
105   RETURNS
106
107   file handle for opened solib, or -1 for failure.  */
108
109int
110solib_open (char *in_pathname, char **found_pathname)
111{
112  int found_file = -1;
113  char *temp_pathname = NULL;
114  char *p = in_pathname;
115
116  while (*p && !IS_DIR_SEPARATOR (*p))
117    p++;
118
119  if (*p)
120    {
121      if (! IS_ABSOLUTE_PATH (in_pathname) || solib_absolute_prefix == NULL)
122        temp_pathname = in_pathname;
123      else
124	{
125	  int prefix_len = strlen (solib_absolute_prefix);
126
127	  /* Remove trailing slashes from absolute prefix.  */
128	  while (prefix_len > 0
129		 && IS_DIR_SEPARATOR (solib_absolute_prefix[prefix_len - 1]))
130	    prefix_len--;
131
132	  /* Cat the prefixed pathname together.  */
133	  temp_pathname = alloca (prefix_len + strlen (in_pathname) + 1);
134	  strncpy (temp_pathname, solib_absolute_prefix, prefix_len);
135	  temp_pathname[prefix_len] = '\0';
136	  strcat (temp_pathname, in_pathname);
137	}
138
139      /* Now see if we can open it.  */
140      found_file = open (temp_pathname, O_RDONLY, 0);
141    }
142
143  /* If the search in solib_absolute_prefix failed, and the path name is
144     absolute at this point, make it relative.  (openp will try and open the
145     file according to its absolute path otherwise, which is not what we want.)
146     Affects subsequent searches for this solib.  */
147  if (found_file < 0 && IS_ABSOLUTE_PATH (in_pathname))
148    {
149      /* First, get rid of any drive letters etc.  */
150      while (!IS_DIR_SEPARATOR (*in_pathname))
151        in_pathname++;
152
153      /* Next, get rid of all leading dir separators.  */
154      while (IS_DIR_SEPARATOR (*in_pathname))
155        in_pathname++;
156    }
157
158  /* If not found, search the solib_search_path (if any).  */
159  if (found_file < 0 && solib_search_path != NULL)
160    found_file = openp (solib_search_path, OPF_TRY_CWD_FIRST,
161			in_pathname, O_RDONLY, 0, &temp_pathname);
162
163  /* If not found, next search the solib_search_path (if any) for the basename
164     only (ignoring the path).  This is to allow reading solibs from a path
165     that differs from the opened path.  */
166  if (found_file < 0 && solib_search_path != NULL)
167    found_file = openp (solib_search_path, OPF_TRY_CWD_FIRST,
168                        lbasename (in_pathname), O_RDONLY, 0,
169                        &temp_pathname);
170
171  /* If not found, try to use target supplied solib search method */
172  if (found_file < 0 && TARGET_SO_FIND_AND_OPEN_SOLIB != NULL)
173    found_file = TARGET_SO_FIND_AND_OPEN_SOLIB
174                 (in_pathname, O_RDONLY, &temp_pathname);
175
176  /* If not found, next search the inferior's $PATH environment variable. */
177  if (found_file < 0 && solib_absolute_prefix == NULL)
178    found_file = openp (get_in_environ (inferior_environ, "PATH"),
179			OPF_TRY_CWD_FIRST, in_pathname, O_RDONLY, 0,
180			&temp_pathname);
181
182  /* If not found, next search the inferior's $LD_LIBRARY_PATH
183     environment variable. */
184  if (found_file < 0 && solib_absolute_prefix == NULL)
185    found_file = openp (get_in_environ (inferior_environ, "LD_LIBRARY_PATH"),
186			OPF_TRY_CWD_FIRST, in_pathname, O_RDONLY, 0,
187			&temp_pathname);
188
189  /* Done.  If not found, tough luck.  Return found_file and
190     (optionally) found_pathname.  */
191  if (found_pathname != NULL && temp_pathname != NULL)
192    *found_pathname = xstrdup (temp_pathname);
193  return found_file;
194}
195
196
197/*
198
199   LOCAL FUNCTION
200
201   solib_map_sections -- open bfd and build sections for shared lib
202
203   SYNOPSIS
204
205   static int solib_map_sections (struct so_list *so)
206
207   DESCRIPTION
208
209   Given a pointer to one of the shared objects in our list
210   of mapped objects, use the recorded name to open a bfd
211   descriptor for the object, build a section table, and then
212   relocate all the section addresses by the base address at
213   which the shared object was mapped.
214
215   FIXMES
216
217   In most (all?) cases the shared object file name recorded in the
218   dynamic linkage tables will be a fully qualified pathname.  For
219   cases where it isn't, do we really mimic the systems search
220   mechanism correctly in the below code (particularly the tilde
221   expansion stuff?).
222 */
223
224static int
225solib_map_sections (void *arg)
226{
227  struct so_list *so = (struct so_list *) arg;	/* catch_errors bogon */
228  char *filename;
229  char *scratch_pathname;
230  int scratch_chan;
231  struct section_table *p;
232  struct cleanup *old_chain;
233  bfd *abfd;
234
235  filename = tilde_expand (so->so_name);
236
237  old_chain = make_cleanup (xfree, filename);
238  scratch_chan = solib_open (filename, &scratch_pathname);
239
240  if (scratch_chan < 0)
241    {
242      perror_with_name (filename);
243    }
244
245  /* Leave scratch_pathname allocated.  abfd->name will point to it.  */
246  abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
247  if (!abfd)
248    {
249      close (scratch_chan);
250      error ("Could not open `%s' as an executable file: %s",
251	     scratch_pathname, bfd_errmsg (bfd_get_error ()));
252    }
253
254  /* Leave bfd open, core_xfer_memory and "info files" need it.  */
255  so->abfd = abfd;
256  bfd_set_cacheable (abfd, 1);
257
258  /* copy full path name into so_name, so that later symbol_file_add
259     can find it */
260  if (strlen (scratch_pathname) >= SO_NAME_MAX_PATH_SIZE)
261    error ("Full path name length of shared library exceeds SO_NAME_MAX_PATH_SIZE in so_list structure.");
262  strcpy (so->so_name, scratch_pathname);
263
264  if (!bfd_check_format (abfd, bfd_object))
265    {
266      error ("\"%s\": not in executable format: %s.",
267	     scratch_pathname, bfd_errmsg (bfd_get_error ()));
268    }
269  if (build_section_table (abfd, &so->sections, &so->sections_end))
270    {
271      error ("Can't find the file sections in `%s': %s",
272	     bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
273    }
274
275  for (p = so->sections; p < so->sections_end; p++)
276    {
277      /* Relocate the section binding addresses as recorded in the shared
278         object's file by the base address to which the object was actually
279         mapped. */
280      TARGET_SO_RELOCATE_SECTION_ADDRESSES (so, p);
281      if (strcmp (p->the_bfd_section->name, ".text") == 0)
282	{
283	  so->textsection = p;
284	}
285    }
286
287  /* Free the file names, close the file now.  */
288  do_cleanups (old_chain);
289
290  return (1);
291}
292
293/* LOCAL FUNCTION
294
295   free_so --- free a `struct so_list' object
296
297   SYNOPSIS
298
299   void free_so (struct so_list *so)
300
301   DESCRIPTION
302
303   Free the storage associated with the `struct so_list' object SO.
304   If we have opened a BFD for SO, close it.
305
306   The caller is responsible for removing SO from whatever list it is
307   a member of.  If we have placed SO's sections in some target's
308   section table, the caller is responsible for removing them.
309
310   This function doesn't mess with objfiles at all.  If there is an
311   objfile associated with SO that needs to be removed, the caller is
312   responsible for taking care of that.  */
313
314void
315free_so (struct so_list *so)
316{
317  char *bfd_filename = 0;
318
319  if (so->sections)
320    xfree (so->sections);
321
322  if (so->abfd)
323    {
324      bfd_filename = bfd_get_filename (so->abfd);
325      if (! bfd_close (so->abfd))
326	warning ("cannot close \"%s\": %s",
327		 bfd_filename, bfd_errmsg (bfd_get_error ()));
328    }
329
330  if (bfd_filename)
331    xfree (bfd_filename);
332
333  TARGET_SO_FREE_SO (so);
334
335  xfree (so);
336}
337
338
339/* Return address of first so_list entry in master shared object list.  */
340struct so_list *
341master_so_list (void)
342{
343  return so_list_head;
344}
345
346
347/* A small stub to get us past the arg-passing pinhole of catch_errors.  */
348
349static int
350symbol_add_stub (void *arg)
351{
352  struct so_list *so = (struct so_list *) arg;  /* catch_errs bogon */
353  struct section_addr_info *sap;
354
355  /* Have we already loaded this shared object?  */
356  ALL_OBJFILES (so->objfile)
357    {
358      if (strcmp (so->objfile->name, so->so_name) == 0)
359	return 1;
360    }
361
362  sap = build_section_addr_info_from_section_table (so->sections,
363                                                    so->sections_end);
364
365  so->objfile = symbol_file_add (so->so_name, so->from_tty,
366				 sap, 0, OBJF_SHARED);
367  free_section_addr_info (sap);
368
369  return (1);
370}
371
372
373/* LOCAL FUNCTION
374
375   update_solib_list --- synchronize GDB's shared object list with inferior's
376
377   SYNOPSIS
378
379   void update_solib_list (int from_tty, struct target_ops *TARGET)
380
381   Extract the list of currently loaded shared objects from the
382   inferior, and compare it with the list of shared objects currently
383   in GDB's so_list_head list.  Edit so_list_head to bring it in sync
384   with the inferior's new list.
385
386   If we notice that the inferior has unloaded some shared objects,
387   free any symbolic info GDB had read about those shared objects.
388
389   Don't load symbolic info for any new shared objects; just add them
390   to the list, and leave their symbols_loaded flag clear.
391
392   If FROM_TTY is non-null, feel free to print messages about what
393   we're doing.
394
395   If TARGET is non-null, add the sections of all new shared objects
396   to TARGET's section table.  Note that this doesn't remove any
397   sections for shared objects that have been unloaded, and it
398   doesn't check to see if the new shared objects are already present in
399   the section table.  But we only use this for core files and
400   processes we've just attached to, so that's okay.  */
401
402static void
403update_solib_list (int from_tty, struct target_ops *target)
404{
405  struct so_list *inferior = TARGET_SO_CURRENT_SOS ();
406  struct so_list *gdb, **gdb_link;
407
408  /* If we are attaching to a running process for which we
409     have not opened a symbol file, we may be able to get its
410     symbols now!  */
411  if (attach_flag &&
412      symfile_objfile == NULL)
413    catch_errors (TARGET_SO_OPEN_SYMBOL_FILE_OBJECT, &from_tty,
414		  "Error reading attached process's symbol file.\n",
415		  RETURN_MASK_ALL);
416
417  /* Since this function might actually add some elements to the
418     so_list_head list, arrange for it to be cleaned up when
419     appropriate.  */
420  if (!solib_cleanup_queued)
421    {
422      make_run_cleanup (do_clear_solib, NULL);
423      solib_cleanup_queued = 1;
424    }
425
426  /* GDB and the inferior's dynamic linker each maintain their own
427     list of currently loaded shared objects; we want to bring the
428     former in sync with the latter.  Scan both lists, seeing which
429     shared objects appear where.  There are three cases:
430
431     - A shared object appears on both lists.  This means that GDB
432     knows about it already, and it's still loaded in the inferior.
433     Nothing needs to happen.
434
435     - A shared object appears only on GDB's list.  This means that
436     the inferior has unloaded it.  We should remove the shared
437     object from GDB's tables.
438
439     - A shared object appears only on the inferior's list.  This
440     means that it's just been loaded.  We should add it to GDB's
441     tables.
442
443     So we walk GDB's list, checking each entry to see if it appears
444     in the inferior's list too.  If it does, no action is needed, and
445     we remove it from the inferior's list.  If it doesn't, the
446     inferior has unloaded it, and we remove it from GDB's list.  By
447     the time we're done walking GDB's list, the inferior's list
448     contains only the new shared objects, which we then add.  */
449
450  gdb = so_list_head;
451  gdb_link = &so_list_head;
452  while (gdb)
453    {
454      struct so_list *i = inferior;
455      struct so_list **i_link = &inferior;
456
457      /* Check to see whether the shared object *gdb also appears in
458	 the inferior's current list.  */
459      while (i)
460	{
461	  if (! strcmp (gdb->so_original_name, i->so_original_name))
462	    break;
463
464	  i_link = &i->next;
465	  i = *i_link;
466	}
467
468      /* If the shared object appears on the inferior's list too, then
469         it's still loaded, so we don't need to do anything.  Delete
470         it from the inferior's list, and leave it on GDB's list.  */
471      if (i)
472	{
473	  *i_link = i->next;
474	  free_so (i);
475	  gdb_link = &gdb->next;
476	  gdb = *gdb_link;
477	}
478
479      /* If it's not on the inferior's list, remove it from GDB's tables.  */
480      else
481	{
482	  /* Notify any observer that the SO has been unloaded
483	     before we remove it from the gdb tables.  */
484	  observer_notify_solib_unloaded (gdb);
485
486	  *gdb_link = gdb->next;
487
488	  /* Unless the user loaded it explicitly, free SO's objfile.  */
489	  if (gdb->objfile && ! (gdb->objfile->flags & OBJF_USERLOADED))
490	    free_objfile (gdb->objfile);
491
492	  /* Some targets' section tables might be referring to
493	     sections from so->abfd; remove them.  */
494	  remove_target_sections (gdb->abfd);
495
496	  free_so (gdb);
497	  gdb = *gdb_link;
498	}
499    }
500
501  /* Now the inferior's list contains only shared objects that don't
502     appear in GDB's list --- those that are newly loaded.  Add them
503     to GDB's shared object list.  */
504  if (inferior)
505    {
506      struct so_list *i;
507
508      /* Add the new shared objects to GDB's list.  */
509      *gdb_link = inferior;
510
511      /* Fill in the rest of each of the `struct so_list' nodes.  */
512      for (i = inferior; i; i = i->next)
513	{
514	  i->from_tty = from_tty;
515
516	  /* Fill in the rest of the `struct so_list' node.  */
517	  catch_errors (solib_map_sections, i,
518			"Error while mapping shared library sections:\n",
519			RETURN_MASK_ALL);
520
521	  /* If requested, add the shared object's sections to the TARGET's
522	     section table.  Do this immediately after mapping the object so
523	     that later nodes in the list can query this object, as is needed
524	     in solib-osf.c.  */
525	  if (target)
526	    {
527	      int count = (i->sections_end - i->sections);
528	      if (count > 0)
529		{
530		  int space = target_resize_to_sections (target, count);
531		  memcpy (target->to_sections + space,
532			  i->sections,
533			  count * sizeof (i->sections[0]));
534		}
535	    }
536	}
537    }
538}
539
540
541/* GLOBAL FUNCTION
542
543   solib_add -- read in symbol info for newly added shared libraries
544
545   SYNOPSIS
546
547   void solib_add (char *pattern, int from_tty, struct target_ops
548   *TARGET, int readsyms)
549
550   DESCRIPTION
551
552   Read in symbolic information for any shared objects whose names
553   match PATTERN.  (If we've already read a shared object's symbol
554   info, leave it alone.)  If PATTERN is zero, read them all.
555
556   If READSYMS is 0, defer reading symbolic information until later
557   but still do any needed low level processing.
558
559   FROM_TTY and TARGET are as described for update_solib_list, above.  */
560
561void
562solib_add (char *pattern, int from_tty, struct target_ops *target, int readsyms)
563{
564  struct so_list *gdb;
565
566  if (pattern)
567    {
568      char *re_err = re_comp (pattern);
569
570      if (re_err)
571	error ("Invalid regexp: %s", re_err);
572    }
573
574  update_solib_list (from_tty, target);
575
576  /* Walk the list of currently loaded shared libraries, and read
577     symbols for any that match the pattern --- or any whose symbols
578     aren't already loaded, if no pattern was given.  */
579  {
580    int any_matches = 0;
581    int loaded_any_symbols = 0;
582
583    for (gdb = so_list_head; gdb; gdb = gdb->next)
584      if (! pattern || re_exec (gdb->so_name))
585	{
586	  any_matches = 1;
587
588	  if (gdb->symbols_loaded)
589	    {
590	      if (from_tty)
591		printf_unfiltered ("Symbols already loaded for %s\n",
592				   gdb->so_name);
593	    }
594	  else if (readsyms)
595	    {
596	      if (catch_errors
597		  (symbol_add_stub, gdb,
598		   "Error while reading shared library symbols:\n",
599		   RETURN_MASK_ALL))
600		{
601		  if (from_tty)
602		    printf_unfiltered ("Loaded symbols for %s\n",
603				       gdb->so_name);
604		  gdb->symbols_loaded = 1;
605		  loaded_any_symbols = 1;
606		}
607	    }
608	}
609
610    if (from_tty && pattern && ! any_matches)
611      printf_unfiltered
612	("No loaded shared libraries match the pattern `%s'.\n", pattern);
613
614    if (loaded_any_symbols)
615      {
616	/* Getting new symbols may change our opinion about what is
617	   frameless.  */
618	reinit_frame_cache ();
619
620	TARGET_SO_SPECIAL_SYMBOL_HANDLING ();
621      }
622  }
623}
624
625
626/*
627
628   LOCAL FUNCTION
629
630   info_sharedlibrary_command -- code for "info sharedlibrary"
631
632   SYNOPSIS
633
634   static void info_sharedlibrary_command ()
635
636   DESCRIPTION
637
638   Walk through the shared library list and print information
639   about each attached library.
640 */
641
642static void
643info_sharedlibrary_command (char *ignore, int from_tty)
644{
645  struct so_list *so = NULL;	/* link map state variable */
646  int header_done = 0;
647  int addr_width;
648
649  if (TARGET_PTR_BIT == 32)
650    addr_width = 8 + 4;
651  else if (TARGET_PTR_BIT == 64)
652    addr_width = 16 + 4;
653  else
654    {
655      internal_error (__FILE__, __LINE__,
656		      "TARGET_PTR_BIT returned unknown size %d",
657		      TARGET_PTR_BIT);
658    }
659
660  update_solib_list (from_tty, 0);
661
662  for (so = so_list_head; so; so = so->next)
663    {
664      if (so->so_name[0])
665	{
666	  if (!header_done)
667	    {
668	      printf_unfiltered ("%-*s%-*s%-12s%s\n", addr_width, "From",
669				 addr_width, "To", "Syms Read",
670				 "Shared Object Library");
671	      header_done++;
672	    }
673
674	  printf_unfiltered ("%-*s", addr_width,
675			     so->textsection != NULL
676			       ? hex_string_custom (
677			           (LONGEST) so->textsection->addr,
678	                           addr_width - 4)
679			       : "");
680	  printf_unfiltered ("%-*s", addr_width,
681			     so->textsection != NULL
682			       ? hex_string_custom (
683			           (LONGEST) so->textsection->endaddr,
684	                           addr_width - 4)
685			       : "");
686	  printf_unfiltered ("%-12s", so->symbols_loaded ? "Yes" : "No");
687	  printf_unfiltered ("%s\n", so->so_name);
688	}
689    }
690  if (so_list_head == NULL)
691    {
692      printf_unfiltered ("No shared libraries loaded at this time.\n");
693    }
694}
695
696/*
697
698   GLOBAL FUNCTION
699
700   solib_address -- check to see if an address is in a shared lib
701
702   SYNOPSIS
703
704   char * solib_address (CORE_ADDR address)
705
706   DESCRIPTION
707
708   Provides a hook for other gdb routines to discover whether or
709   not a particular address is within the mapped address space of
710   a shared library.
711
712   For example, this routine is called at one point to disable
713   breakpoints which are in shared libraries that are not currently
714   mapped in.
715 */
716
717char *
718solib_address (CORE_ADDR address)
719{
720  struct so_list *so = 0;	/* link map state variable */
721
722  for (so = so_list_head; so; so = so->next)
723    {
724      struct section_table *p;
725
726      for (p = so->sections; p < so->sections_end; p++)
727	{
728	  if (p->addr <= address && address < p->endaddr)
729	    return (so->so_name);
730	}
731    }
732
733  return (0);
734}
735
736/* Called by free_all_symtabs */
737
738void
739clear_solib (void)
740{
741  /* This function is expected to handle ELF shared libraries.  It is
742     also used on Solaris, which can run either ELF or a.out binaries
743     (for compatibility with SunOS 4), both of which can use shared
744     libraries.  So we don't know whether we have an ELF executable or
745     an a.out executable until the user chooses an executable file.
746
747     ELF shared libraries don't get mapped into the address space
748     until after the program starts, so we'd better not try to insert
749     breakpoints in them immediately.  We have to wait until the
750     dynamic linker has loaded them; we'll hit a bp_shlib_event
751     breakpoint (look for calls to create_solib_event_breakpoint) when
752     it's ready.
753
754     SunOS shared libraries seem to be different --- they're present
755     as soon as the process begins execution, so there's no need to
756     put off inserting breakpoints.  There's also nowhere to put a
757     bp_shlib_event breakpoint, so if we put it off, we'll never get
758     around to it.
759
760     So: disable breakpoints only if we're using ELF shared libs.  */
761  if (exec_bfd != NULL
762      && bfd_get_flavour (exec_bfd) != bfd_target_aout_flavour)
763    disable_breakpoints_in_shlibs (1);
764
765  while (so_list_head)
766    {
767      struct so_list *so = so_list_head;
768      so_list_head = so->next;
769      if (so->abfd)
770	remove_target_sections (so->abfd);
771      free_so (so);
772    }
773
774  TARGET_SO_CLEAR_SOLIB ();
775}
776
777static void
778do_clear_solib (void *dummy)
779{
780  solib_cleanup_queued = 0;
781  clear_solib ();
782}
783
784/* GLOBAL FUNCTION
785
786   solib_create_inferior_hook -- shared library startup support
787
788   SYNOPSIS
789
790   void solib_create_inferior_hook()
791
792   DESCRIPTION
793
794   When gdb starts up the inferior, it nurses it along (through the
795   shell) until it is ready to execute it's first instruction.  At this
796   point, this function gets called via expansion of the macro
797   SOLIB_CREATE_INFERIOR_HOOK.  */
798
799void
800solib_create_inferior_hook (void)
801{
802  TARGET_SO_SOLIB_CREATE_INFERIOR_HOOK ();
803}
804
805/* GLOBAL FUNCTION
806
807   in_solib_dynsym_resolve_code -- check to see if an address is in
808                                   dynamic loader's dynamic symbol
809				   resolution code
810
811   SYNOPSIS
812
813   int in_solib_dynsym_resolve_code (CORE_ADDR pc)
814
815   DESCRIPTION
816
817   Determine if PC is in the dynamic linker's symbol resolution
818   code.  Return 1 if so, 0 otherwise.
819*/
820
821int
822in_solib_dynsym_resolve_code (CORE_ADDR pc)
823{
824  return TARGET_SO_IN_DYNSYM_RESOLVE_CODE (pc);
825}
826
827/*
828
829   LOCAL FUNCTION
830
831   sharedlibrary_command -- handle command to explicitly add library
832
833   SYNOPSIS
834
835   static void sharedlibrary_command (char *args, int from_tty)
836
837   DESCRIPTION
838
839 */
840
841static void
842sharedlibrary_command (char *args, int from_tty)
843{
844  dont_repeat ();
845  solib_add (args, from_tty, (struct target_ops *) 0, 1);
846}
847
848/* LOCAL FUNCTION
849
850   no_shared_libraries -- handle command to explicitly discard symbols
851   from shared libraries.
852
853   DESCRIPTION
854
855   Implements the command "nosharedlibrary", which discards symbols
856   that have been auto-loaded from shared libraries.  Symbols from
857   shared libraries that were added by explicit request of the user
858   are not discarded.  Also called from remote.c.  */
859
860void
861no_shared_libraries (char *ignored, int from_tty)
862{
863  objfile_purge_solibs ();
864  do_clear_solib (NULL);
865}
866
867static void
868reload_shared_libraries (char *ignored, int from_tty)
869{
870  no_shared_libraries (NULL, from_tty);
871  solib_add (NULL, from_tty, NULL, auto_solib_add);
872}
873
874extern initialize_file_ftype _initialize_solib; /* -Wmissing-prototypes */
875
876void
877_initialize_solib (void)
878{
879  struct cmd_list_element *c;
880
881  add_com ("sharedlibrary", class_files, sharedlibrary_command,
882	   "Load shared object library symbols for files matching REGEXP.");
883  add_info ("sharedlibrary", info_sharedlibrary_command,
884	    "Status of loaded shared object libraries.");
885  add_com ("nosharedlibrary", class_files, no_shared_libraries,
886	   "Unload all shared object library symbols.");
887
888  deprecated_add_show_from_set
889    (add_set_cmd ("auto-solib-add", class_support, var_boolean,
890		  (char *) &auto_solib_add,
891		  "Set autoloading of shared library symbols.\n\
892If \"on\", symbols from all shared object libraries will be loaded\n\
893automatically when the inferior begins execution, when the dynamic linker\n\
894informs gdb that a new library has been loaded, or when attaching to the\n\
895inferior.  Otherwise, symbols must be loaded manually, using `sharedlibrary'.",
896		  &setlist),
897     &showlist);
898
899  c = add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
900		   (char *) &solib_absolute_prefix,
901		   "Set prefix for loading absolute shared library symbol files.\n\
902For other (relative) files, you can add values using `set solib-search-path'.",
903		   &setlist);
904  deprecated_add_show_from_set (c, &showlist);
905  set_cmd_cfunc (c, reload_shared_libraries);
906  set_cmd_completer (c, filename_completer);
907
908  /* Set the default value of "solib-absolute-prefix" from the sysroot, if
909     one is set.  */
910  solib_absolute_prefix = xstrdup (gdb_sysroot);
911
912  c = add_set_cmd ("solib-search-path", class_support, var_string,
913		   (char *) &solib_search_path,
914		   "Set the search path for loading non-absolute shared library symbol files.\n\
915This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
916		   &setlist);
917  deprecated_add_show_from_set (c, &showlist);
918  set_cmd_cfunc (c, reload_shared_libraries);
919  set_cmd_completer (c, filename_completer);
920}
921