xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/solib-aix.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Copyright (C) 2013-2016 Free Software Foundation, Inc.
2 
3    This file is part of GDB.
4 
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 3 of the License, or
8    (at your option) any later version.
9 
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17 
18 #include "defs.h"
19 #include "solib-aix.h"
20 #include "solist.h"
21 #include "inferior.h"
22 #include "gdb_bfd.h"
23 #include "gdbcore.h"
24 #include "objfiles.h"
25 #include "symtab.h"
26 #include "xcoffread.h"
27 #include "observer.h"
28 #include "gdbcmd.h"
29 
30 /* Variable controlling the output of the debugging traces for
31    this module.  */
32 static int solib_aix_debug;
33 
34 /* Our private data in struct so_list.  */
35 
36 struct lm_info
37 {
38   /* The name of the file mapped by the loader.  Apart from the entry
39      for the main executable, this is usually a shared library (which,
40      on AIX, is an archive library file, created using the "ar"
41      command).  */
42   char *filename;
43 
44   /* The name of the shared object file with the actual dynamic
45      loading dependency.  This may be NULL (Eg. main executable).  */
46   char *member_name;
47 
48   /* The address in inferior memory where the text section got mapped.  */
49   CORE_ADDR text_addr;
50 
51   /* The size of the text section, obtained via the loader data.  */
52   ULONGEST text_size;
53 
54   /* The address in inferior memory where the data section got mapped.  */
55   CORE_ADDR data_addr;
56 
57   /* The size of the data section, obtained via the loader data.  */
58   ULONGEST data_size;
59 };
60 
61 typedef struct lm_info *lm_info_p;
62 DEF_VEC_P(lm_info_p);
63 
64 /* Return a deep copy of the given struct lm_info object.  */
65 
66 static struct lm_info *
67 solib_aix_new_lm_info (struct lm_info *info)
68 {
69   struct lm_info *result = XNEW (struct lm_info);
70 
71   memcpy (result, info, sizeof (struct lm_info));
72   result->filename = xstrdup (info->filename);
73   if (info->member_name != NULL)
74     result->member_name = xstrdup (info->member_name);
75 
76   return result;
77 }
78 
79 /* Free the memory allocated for the given lm_info.  */
80 
81 static void
82 solib_aix_xfree_lm_info (struct lm_info *info)
83 {
84   xfree (info->filename);
85   xfree (info->member_name);
86   xfree (info);
87 }
88 
89 /* This module's per-inferior data.  */
90 
91 struct solib_aix_inferior_data
92 {
93   /* The list of shared libraries.  NULL if not computed yet.
94 
95      Note that the first element of this list is always the main
96      executable, which is not technically a shared library.  But
97      we need that information to perform its relocation, and
98      the same principles applied to shared libraries also apply
99      to the main executable.  So it's simpler to keep it as part
100      of this list.  */
101   VEC (lm_info_p) *library_list;
102 };
103 
104 /* Key to our per-inferior data.  */
105 static const struct inferior_data *solib_aix_inferior_data_handle;
106 
107 /* Return this module's data for the given inferior.
108    If none is found, add a zero'ed one now.  */
109 
110 static struct solib_aix_inferior_data *
111 get_solib_aix_inferior_data (struct inferior *inf)
112 {
113   struct solib_aix_inferior_data *data;
114 
115   data = ((struct solib_aix_inferior_data *)
116 	  inferior_data (inf, solib_aix_inferior_data_handle));
117   if (data == NULL)
118     {
119       data = XCNEW (struct solib_aix_inferior_data);
120       set_inferior_data (inf, solib_aix_inferior_data_handle, data);
121     }
122 
123   return data;
124 }
125 
126 #if !defined(HAVE_LIBEXPAT)
127 
128 /* Dummy implementation if XML support is not compiled in.  */
129 
130 static VEC (lm_info_p) *
131 solib_aix_parse_libraries (const char *library)
132 {
133   static int have_warned;
134 
135   if (!have_warned)
136     {
137       have_warned = 1;
138       warning (_("Can not parse XML library list; XML support was disabled "
139                  "at compile time"));
140     }
141 
142   return NULL;
143 }
144 
145 /* Dummy implementation if XML support is not compiled in.  */
146 
147 static void
148 solib_aix_free_library_list (void *p)
149 {
150 }
151 
152 #else /* HAVE_LIBEXPAT */
153 
154 #include "xml-support.h"
155 
156 /* Handle the start of a <library> element.  */
157 
158 static void
159 library_list_start_library (struct gdb_xml_parser *parser,
160 			    const struct gdb_xml_element *element,
161 			    void *user_data,
162 			    VEC (gdb_xml_value_s) *attributes)
163 {
164   VEC (lm_info_p) **list = (VEC (lm_info_p) **) user_data;
165   struct lm_info *item = XCNEW (struct lm_info);
166   struct gdb_xml_value *attr;
167 
168   attr = xml_find_attribute (attributes, "name");
169   item->filename = xstrdup ((const char *) attr->value);
170 
171   attr = xml_find_attribute (attributes, "member");
172   if (attr != NULL)
173     item->member_name = xstrdup ((const char *) attr->value);
174 
175   attr = xml_find_attribute (attributes, "text_addr");
176   item->text_addr = * (ULONGEST *) attr->value;
177 
178   attr = xml_find_attribute (attributes, "text_size");
179   item->text_size = * (ULONGEST *) attr->value;
180 
181   attr = xml_find_attribute (attributes, "data_addr");
182   item->data_addr = * (ULONGEST *) attr->value;
183 
184   attr = xml_find_attribute (attributes, "data_size");
185   item->data_size = * (ULONGEST *) attr->value;
186 
187   VEC_safe_push (lm_info_p, *list, item);
188 }
189 
190 /* Handle the start of a <library-list-aix> element.  */
191 
192 static void
193 library_list_start_list (struct gdb_xml_parser *parser,
194                          const struct gdb_xml_element *element,
195                          void *user_data, VEC (gdb_xml_value_s) *attributes)
196 {
197   char *version = (char *) xml_find_attribute (attributes, "version")->value;
198 
199   if (strcmp (version, "1.0") != 0)
200     gdb_xml_error (parser,
201                    _("Library list has unsupported version \"%s\""),
202                    version);
203 }
204 
205 /* Discard the constructed library list.  */
206 
207 static void
208 solib_aix_free_library_list (void *p)
209 {
210   VEC (lm_info_p) **result = (VEC (lm_info_p) **) p;
211   struct lm_info *info;
212   int ix;
213 
214   if (solib_aix_debug)
215     fprintf_unfiltered (gdb_stdlog, "DEBUG: solib_aix_free_library_list\n");
216 
217   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
218     solib_aix_xfree_lm_info (info);
219   VEC_free (lm_info_p, *result);
220   *result = NULL;
221 }
222 
223 /* The allowed elements and attributes for an AIX library list
224    described in XML format.  The root element is a <library-list-aix>.  */
225 
226 static const struct gdb_xml_attribute library_attributes[] =
227 {
228   { "name", GDB_XML_AF_NONE, NULL, NULL },
229   { "member", GDB_XML_AF_OPTIONAL, NULL, NULL },
230   { "text_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
231   { "text_size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
232   { "data_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
233   { "data_size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
234   { NULL, GDB_XML_AF_NONE, NULL, NULL }
235 };
236 
237 static const struct gdb_xml_element library_list_children[] =
238 {
239   { "library", library_attributes, NULL,
240     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
241     library_list_start_library, NULL},
242   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
243 };
244 
245 static const struct gdb_xml_attribute library_list_attributes[] =
246 {
247   { "version", GDB_XML_AF_NONE, NULL, NULL },
248   { NULL, GDB_XML_AF_NONE, NULL, NULL }
249 };
250 
251 static const struct gdb_xml_element library_list_elements[] =
252 {
253   { "library-list-aix", library_list_attributes, library_list_children,
254     GDB_XML_EF_NONE, library_list_start_list, NULL },
255   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
256 };
257 
258 /* Parse LIBRARY, a string containing the loader info in XML format,
259    and return an lm_info_p vector.
260 
261    Return NULL if the parsing failed.  */
262 
263 static VEC (lm_info_p) *
264 solib_aix_parse_libraries (const char *library)
265 {
266   VEC (lm_info_p) *result = NULL;
267   struct cleanup *back_to = make_cleanup (solib_aix_free_library_list,
268                                           &result);
269 
270   if (gdb_xml_parse_quick (_("aix library list"), "library-list-aix.dtd",
271                            library_list_elements, library, &result) == 0)
272     {
273       /* Parsed successfully, keep the result.  */
274       discard_cleanups (back_to);
275       return result;
276     }
277 
278   do_cleanups (back_to);
279   return NULL;
280 }
281 
282 #endif /* HAVE_LIBEXPAT */
283 
284 /* Return the loader info for the given inferior (INF), or NULL if
285    the list could not be computed.
286 
287    Cache the result in per-inferior data, so as to avoid recomputing it
288    each time this function is called.
289 
290    If an error occurs while computing this list, and WARNING_MSG
291    is not NULL, then print a warning including WARNING_MSG and
292    a description of the error.  */
293 
294 static VEC (lm_info_p) *
295 solib_aix_get_library_list (struct inferior *inf, const char *warning_msg)
296 {
297   struct solib_aix_inferior_data *data;
298   char *library_document;
299   struct cleanup *cleanup;
300 
301   /* If already computed, return the cached value.  */
302   data = get_solib_aix_inferior_data (inf);
303   if (data->library_list != NULL)
304     return data->library_list;
305 
306   library_document = target_read_stralloc (&current_target,
307                                            TARGET_OBJECT_LIBRARIES_AIX,
308                                            NULL);
309   if (library_document == NULL && warning_msg != NULL)
310     {
311       warning (_("%s (failed to read TARGET_OBJECT_LIBRARIES_AIX)"),
312 	       warning_msg);
313       return NULL;
314     }
315   cleanup = make_cleanup (xfree, library_document);
316 
317   if (solib_aix_debug)
318     fprintf_unfiltered (gdb_stdlog,
319 			"DEBUG: TARGET_OBJECT_LIBRARIES_AIX = \n%s\n",
320 			library_document);
321 
322   data->library_list = solib_aix_parse_libraries (library_document);
323   if (data->library_list == NULL && warning_msg != NULL)
324     {
325       warning (_("%s (missing XML support?)"), warning_msg);
326       do_cleanups (cleanup);
327       return NULL;
328     }
329 
330   do_cleanups (cleanup);
331   return data->library_list;
332 }
333 
334 /* If the .bss section's VMA is set to an address located before
335    the end of the .data section, causing the two sections to overlap,
336    return the overlap in bytes.  Otherwise, return zero.
337 
338    Motivation:
339 
340    The GNU linker sometimes sets the start address of the .bss session
341    before the end of the .data section, making the 2 sections overlap.
342    The loader appears to handle this situation gracefully, by simply
343    loading the bss section right after the end of the .data section.
344 
345    This means that the .data and the .bss sections are sometimes
346    no longer relocated by the same amount.  The problem is that
347    the ldinfo data does not contain any information regarding
348    the relocation of the .bss section, assuming that it would be
349    identical to the information provided for the .data section
350    (this is what would normally happen if the program was linked
351    correctly).
352 
353    GDB therefore needs to detect those cases, and make the corresponding
354    adjustment to the .bss section offset computed from the ldinfo data
355    when necessary.  This function returns the adjustment amount  (or
356    zero when no adjustment is needed).  */
357 
358 static CORE_ADDR
359 solib_aix_bss_data_overlap (bfd *abfd)
360 {
361   struct bfd_section *data_sect, *bss_sect;
362 
363   data_sect = bfd_get_section_by_name (abfd, ".data");
364   if (data_sect == NULL)
365     return 0; /* No overlap possible.  */
366 
367   bss_sect = bfd_get_section_by_name (abfd, ".bss");
368   if (bss_sect == NULL)
369     return 0; /* No overlap possible.  */
370 
371   /* Assume the problem only occurs with linkers that place the .bss
372      section after the .data section (the problem has only been
373      observed when using the GNU linker, and the default linker
374      script always places the .data and .bss sections in that order).  */
375   if (bfd_section_vma (abfd, bss_sect)
376       < bfd_section_vma (abfd, data_sect))
377     return 0;
378 
379   if (bfd_section_vma (abfd, bss_sect)
380       < bfd_section_vma (abfd, data_sect) + bfd_get_section_size (data_sect))
381     return ((bfd_section_vma (abfd, data_sect)
382 	     + bfd_get_section_size (data_sect))
383 	    - bfd_section_vma (abfd, bss_sect));
384 
385   return 0;
386 }
387 
388 /* Implement the "relocate_section_addresses" target_so_ops method.  */
389 
390 static void
391 solib_aix_relocate_section_addresses (struct so_list *so,
392 				      struct target_section *sec)
393 {
394   struct bfd_section *bfd_sect = sec->the_bfd_section;
395   bfd *abfd = bfd_sect->owner;
396   const char *section_name = bfd_section_name (abfd, bfd_sect);
397   struct lm_info *info = so->lm_info;
398 
399   if (strcmp (section_name, ".text") == 0)
400     {
401       sec->addr = info->text_addr;
402       sec->endaddr = sec->addr + info->text_size;
403 
404       /* The text address given to us by the loader contains
405 	 XCOFF headers, so we need to adjust by this much.  */
406       sec->addr += bfd_sect->filepos;
407     }
408   else if (strcmp (section_name, ".data") == 0)
409     {
410       sec->addr = info->data_addr;
411       sec->endaddr = sec->addr + info->data_size;
412     }
413   else if (strcmp (section_name, ".bss") == 0)
414     {
415       /* The information provided by the loader does not include
416 	 the address of the .bss section, but we know that it gets
417 	 relocated by the same offset as the .data section.  So,
418 	 compute the relocation offset for the .data section, and
419 	 apply it to the .bss section as well.  If the .data section
420 	 is not defined (which seems highly unlikely), do our best
421 	 by assuming no relocation.  */
422       struct bfd_section *data_sect
423 	= bfd_get_section_by_name (abfd, ".data");
424       CORE_ADDR data_offset = 0;
425 
426       if (data_sect != NULL)
427 	data_offset = info->data_addr - bfd_section_vma (abfd, data_sect);
428 
429       sec->addr = bfd_section_vma (abfd, bfd_sect) + data_offset;
430       sec->addr += solib_aix_bss_data_overlap (abfd);
431       sec->endaddr = sec->addr + bfd_section_size (abfd, bfd_sect);
432     }
433   else
434     {
435       /* All other sections should not be relocated.  */
436       sec->addr = bfd_section_vma (abfd, bfd_sect);
437       sec->endaddr = sec->addr + bfd_section_size (abfd, bfd_sect);
438     }
439 }
440 
441 /* Implement the "free_so" target_so_ops method.  */
442 
443 static void
444 solib_aix_free_so (struct so_list *so)
445 {
446   if (solib_aix_debug)
447     fprintf_unfiltered (gdb_stdlog, "DEBUG: solib_aix_free_so (%s)\n",
448 			so->so_name);
449   solib_aix_xfree_lm_info (so->lm_info);
450 }
451 
452 /* Implement the "clear_solib" target_so_ops method.  */
453 
454 static void
455 solib_aix_clear_solib (void)
456 {
457   /* Nothing needed.  */
458 }
459 
460 /* Compute and return the OBJFILE's section_offset array, using
461    the associated loader info (INFO).
462 
463    The resulting array is computed on the heap and must be
464    deallocated after use.  */
465 
466 static struct section_offsets *
467 solib_aix_get_section_offsets (struct objfile *objfile,
468 			       struct lm_info *info)
469 {
470   struct section_offsets *offsets;
471   bfd *abfd = objfile->obfd;
472 
473   offsets = XCNEWVEC (struct section_offsets, objfile->num_sections);
474 
475   /* .text */
476 
477   if (objfile->sect_index_text != -1)
478     {
479       struct bfd_section *sect
480 	= objfile->sections[objfile->sect_index_text].the_bfd_section;
481 
482       offsets->offsets[objfile->sect_index_text]
483 	= info->text_addr + sect->filepos - bfd_section_vma (abfd, sect);
484     }
485 
486   /* .data */
487 
488   if (objfile->sect_index_data != -1)
489     {
490       struct bfd_section *sect
491 	= objfile->sections[objfile->sect_index_data].the_bfd_section;
492 
493       offsets->offsets[objfile->sect_index_data]
494 	= info->data_addr - bfd_section_vma (abfd, sect);
495     }
496 
497   /* .bss
498 
499      The offset of the .bss section should be identical to the offset
500      of the .data section.  If no .data section (which seems hard to
501      believe it is possible), assume it is zero.  */
502 
503   if (objfile->sect_index_bss != -1
504       && objfile->sect_index_data != -1)
505     {
506       offsets->offsets[objfile->sect_index_bss]
507 	= (offsets->offsets[objfile->sect_index_data]
508 	   + solib_aix_bss_data_overlap (abfd));
509     }
510 
511   /* All other sections should not need relocation.  */
512 
513   return offsets;
514 }
515 
516 /* Implement the "solib_create_inferior_hook" target_so_ops method.  */
517 
518 static void
519 solib_aix_solib_create_inferior_hook (int from_tty)
520 {
521   const char *warning_msg = "unable to relocate main executable";
522   VEC (lm_info_p) *library_list;
523   struct lm_info *exec_info;
524 
525   /* We need to relocate the main executable...  */
526 
527   library_list = solib_aix_get_library_list (current_inferior (),
528 					     warning_msg);
529   if (library_list == NULL)
530     return;  /* Warning already printed.  */
531 
532   if (VEC_length (lm_info_p, library_list) < 1)
533     {
534       warning (_("unable to relocate main executable (no info from loader)"));
535       return;
536     }
537 
538   exec_info = VEC_index (lm_info_p, library_list, 0);
539 
540   if (symfile_objfile != NULL)
541     {
542       struct section_offsets *offsets
543 	= solib_aix_get_section_offsets (symfile_objfile, exec_info);
544       struct cleanup *cleanup = make_cleanup (xfree, offsets);
545 
546       objfile_relocate (symfile_objfile, offsets);
547       do_cleanups (cleanup);
548     }
549 }
550 
551 /* Implement the "special_symbol_handling" target_so_ops method.  */
552 
553 static void
554 solib_aix_special_symbol_handling (void)
555 {
556   /* Nothing needed.  */
557 }
558 
559 /* Implement the "current_sos" target_so_ops method.  */
560 
561 static struct so_list *
562 solib_aix_current_sos (void)
563 {
564   struct so_list *start = NULL, *last = NULL;
565   VEC (lm_info_p) *library_list;
566   struct lm_info *info;
567   int ix;
568 
569   library_list = solib_aix_get_library_list (current_inferior (), NULL);
570   if (library_list == NULL)
571     return NULL;
572 
573   /* Build a struct so_list for each entry on the list.
574      We skip the first entry, since this is the entry corresponding
575      to the main executable, not a shared library.  */
576   for (ix = 1; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
577     {
578       struct so_list *new_solib = XCNEW (struct so_list);
579       char *so_name;
580 
581       if (info->member_name == NULL)
582 	{
583 	 /* INFO->FILENAME is probably not an archive, but rather
584 	    a shared object.  Unusual, but it should be possible
585 	    to link a program against a shared object directory,
586 	    without having to put it in an archive first.  */
587 	 so_name = xstrdup (info->filename);
588 	}
589       else
590 	{
591 	 /* This is the usual case on AIX, where the shared object
592 	    is a member of an archive.  Create a synthetic so_name
593 	    that follows the same convention as AIX's ldd tool
594 	    (Eg: "/lib/libc.a(shr.o)").  */
595 	 so_name = xstrprintf ("%s(%s)", info->filename, info->member_name);
596 	}
597       strncpy (new_solib->so_original_name, so_name,
598 	       SO_NAME_MAX_PATH_SIZE - 1);
599       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
600       memcpy (new_solib->so_name, new_solib->so_original_name,
601 	      SO_NAME_MAX_PATH_SIZE);
602       new_solib->lm_info = solib_aix_new_lm_info (info);
603 
604       /* Add it to the list.  */
605       if (!start)
606         last = start = new_solib;
607       else
608         {
609           last->next = new_solib;
610           last = new_solib;
611         }
612     }
613 
614   return start;
615 }
616 
617 /* Implement the "open_symbol_file_object" target_so_ops method.  */
618 
619 static int
620 solib_aix_open_symbol_file_object (void *from_ttyp)
621 {
622   return 0;
623 }
624 
625 /* Implement the "in_dynsym_resolve_code" target_so_ops method.  */
626 
627 static int
628 solib_aix_in_dynsym_resolve_code (CORE_ADDR pc)
629 {
630   return 0;
631 }
632 
633 /* Implement the "bfd_open" target_so_ops method.  */
634 
635 static bfd *
636 solib_aix_bfd_open (char *pathname)
637 {
638   /* The pathname is actually a synthetic filename with the following
639      form: "/path/to/sharedlib(member.o)" (double-quotes excluded).
640      split this into archive name and member name.
641 
642      FIXME: This is a little hacky.  Perhaps we should provide access
643      to the solib's lm_info here?  */
644   const int path_len = strlen (pathname);
645   char *sep;
646   char *filename;
647   int filename_len;
648   char *member_name;
649   bfd *archive_bfd, *object_bfd;
650   struct cleanup *cleanup;
651 
652   if (pathname[path_len - 1] != ')')
653     return solib_bfd_open (pathname);
654 
655   /* Search for the associated parens.  */
656   sep = strrchr (pathname, '(');
657   if (sep == NULL)
658     {
659       /* Should never happen, but recover as best as we can (trying
660 	 to open pathname without decoding, possibly leading to
661 	 a failure), rather than triggering an assert failure).  */
662       warning (_("missing '(' in shared object pathname: %s"), pathname);
663       return solib_bfd_open (pathname);
664     }
665   filename_len = sep - pathname;
666 
667   filename = xstrprintf ("%.*s", filename_len, pathname);
668   cleanup = make_cleanup (xfree, filename);
669   member_name = xstrprintf ("%.*s", path_len - filename_len - 2, sep + 1);
670   make_cleanup (xfree, member_name);
671 
672   archive_bfd = gdb_bfd_open (filename, gnutarget, -1);
673   if (archive_bfd == NULL)
674     {
675       warning (_("Could not open `%s' as an executable file: %s"),
676 	       filename, bfd_errmsg (bfd_get_error ()));
677       do_cleanups (cleanup);
678       return NULL;
679     }
680 
681   if (bfd_check_format (archive_bfd, bfd_object))
682     {
683       do_cleanups (cleanup);
684       return archive_bfd;
685     }
686 
687   if (! bfd_check_format (archive_bfd, bfd_archive))
688     {
689       warning (_("\"%s\": not in executable format: %s."),
690 	       filename, bfd_errmsg (bfd_get_error ()));
691       gdb_bfd_unref (archive_bfd);
692       do_cleanups (cleanup);
693       return NULL;
694     }
695 
696   object_bfd = gdb_bfd_openr_next_archived_file (archive_bfd, NULL);
697   while (object_bfd != NULL)
698     {
699       bfd *next;
700 
701       if (strcmp (member_name, object_bfd->filename) == 0)
702 	break;
703 
704       next = gdb_bfd_openr_next_archived_file (archive_bfd, object_bfd);
705       gdb_bfd_unref (object_bfd);
706       object_bfd = next;
707     }
708 
709   if (object_bfd == NULL)
710     {
711       warning (_("\"%s\": member \"%s\" missing."), filename, member_name);
712       gdb_bfd_unref (archive_bfd);
713       do_cleanups (cleanup);
714       return NULL;
715     }
716 
717   if (! bfd_check_format (object_bfd, bfd_object))
718     {
719       warning (_("%s(%s): not in object format: %s."),
720 	       filename, member_name, bfd_errmsg (bfd_get_error ()));
721       gdb_bfd_unref (archive_bfd);
722       gdb_bfd_unref (object_bfd);
723       do_cleanups (cleanup);
724       return NULL;
725     }
726 
727   /* Override the returned bfd's name with our synthetic name in order
728      to allow commands listing all shared libraries to display that
729      synthetic name.  Otherwise, we would only be displaying the name
730      of the archive member object.  */
731   xfree (bfd_get_filename (object_bfd));
732   object_bfd->filename = xstrdup (pathname);
733 
734   gdb_bfd_unref (archive_bfd);
735   do_cleanups (cleanup);
736   return object_bfd;
737 }
738 
739 /* Return the obj_section corresponding to OBJFILE's data section,
740    or NULL if not found.  */
741 /* FIXME: Define in a more general location? */
742 
743 static struct obj_section *
744 data_obj_section_from_objfile (struct objfile *objfile)
745 {
746   struct obj_section *osect;
747 
748   ALL_OBJFILE_OSECTIONS (objfile, osect)
749     if (strcmp (bfd_section_name (objfile->obfd, osect->the_bfd_section),
750 		".data") == 0)
751       return osect;
752 
753   return NULL;
754 }
755 
756 /* Return the TOC value corresponding to the given PC address,
757    or raise an error if the value could not be determined.  */
758 
759 CORE_ADDR
760 solib_aix_get_toc_value (CORE_ADDR pc)
761 {
762   struct obj_section *pc_osect = find_pc_section (pc);
763   struct obj_section *data_osect;
764   CORE_ADDR result;
765 
766   if (pc_osect == NULL)
767     error (_("unable to find TOC entry for pc %s "
768 	     "(no section contains this PC)"),
769 	   core_addr_to_string (pc));
770 
771   data_osect = data_obj_section_from_objfile (pc_osect->objfile);
772   if (data_osect == NULL)
773     error (_("unable to find TOC entry for pc %s "
774 	     "(%s has no data section)"),
775 	   core_addr_to_string (pc), objfile_name (pc_osect->objfile));
776 
777   result = (obj_section_addr (data_osect)
778 	    + xcoff_get_toc_offset (pc_osect->objfile));
779   if (solib_aix_debug)
780     fprintf_unfiltered (gdb_stdlog,
781 			"DEBUG: solib_aix_get_toc_value (pc=%s) -> %s\n",
782 			core_addr_to_string (pc),
783 			core_addr_to_string (result));
784 
785   return result;
786 }
787 
788 /* This module's normal_stop observer.  */
789 
790 static void
791 solib_aix_normal_stop_observer (struct bpstats *unused_1, int unused_2)
792 {
793   struct solib_aix_inferior_data *data
794     = get_solib_aix_inferior_data (current_inferior ());
795 
796   /* The inferior execution has been resumed, and it just stopped
797      again.  This means that the list of shared libraries may have
798      evolved.  Reset our cached value.  */
799   solib_aix_free_library_list (&data->library_list);
800 }
801 
802 /* Implements the "show debug aix-solib" command.  */
803 
804 static void
805 show_solib_aix_debug (struct ui_file *file, int from_tty,
806 		      struct cmd_list_element *c, const char *value)
807 {
808   fprintf_filtered (file, _("solib-aix debugging is %s.\n"), value);
809 }
810 
811 /* The target_so_ops for AIX targets.  */
812 struct target_so_ops solib_aix_so_ops;
813 
814 /* -Wmissing-prototypes */
815 extern initialize_file_ftype _initialize_solib_aix;
816 
817 void
818 _initialize_solib_aix (void)
819 {
820   solib_aix_so_ops.relocate_section_addresses
821     = solib_aix_relocate_section_addresses;
822   solib_aix_so_ops.free_so = solib_aix_free_so;
823   solib_aix_so_ops.clear_solib = solib_aix_clear_solib;
824   solib_aix_so_ops.solib_create_inferior_hook
825     = solib_aix_solib_create_inferior_hook;
826   solib_aix_so_ops.special_symbol_handling
827     = solib_aix_special_symbol_handling;
828   solib_aix_so_ops.current_sos = solib_aix_current_sos;
829   solib_aix_so_ops.open_symbol_file_object
830     = solib_aix_open_symbol_file_object;
831   solib_aix_so_ops.in_dynsym_resolve_code
832     = solib_aix_in_dynsym_resolve_code;
833   solib_aix_so_ops.bfd_open = solib_aix_bfd_open;
834 
835   solib_aix_inferior_data_handle = register_inferior_data ();
836 
837   observer_attach_normal_stop (solib_aix_normal_stop_observer);
838 
839   /* Debug this file's internals.  */
840   add_setshow_boolean_cmd ("aix-solib", class_maintenance,
841 			   &solib_aix_debug, _("\
842 Control the debugging traces for the solib-aix module."), _("\
843 Show whether solib-aix debugging traces are enabled."), _("\
844 When on, solib-aix debugging traces are enabled."),
845                             NULL,
846                             show_solib_aix_debug,
847                             &setdebuglist, &showdebuglist);
848 }
849