gdb/solib-aix.c

   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 }