gdb/solib-aix.c

   1 /* Copyright (C) 2013-2019 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 "observable.h"
  28 #include "gdbcmd.h"
  29 #include "gdbsupport/scope-exit.h"
  30
  31 /* Variable controlling the output of the debugging traces for
  32    this module.  */
  33 static bool solib_aix_debug;
  34
  35 /* Our private data in struct so_list.  */
  36
  37 struct lm_info_aix : public lm_info_base
  38 {
  39   /* The name of the file mapped by the loader.  Apart from the entry
  40      for the main executable, this is usually a shared library (which,
  41      on AIX, is an archive library file, created using the "ar"
  42      command).  */
  43   std::string filename;
  44
  45   /* The name of the shared object file with the actual dynamic
  46      loading dependency.  This may be empty (Eg. main executable).  */
  47   std::string member_name;
  48
  49   /* The address in inferior memory where the text section got mapped.  */
  50   CORE_ADDR text_addr = 0;
  51
  52   /* The size of the text section, obtained via the loader data.  */
  53   ULONGEST text_size = 0;
  54
  55   /* The address in inferior memory where the data section got mapped.  */
  56   CORE_ADDR data_addr = 0;
  57
  58   /* The size of the data section, obtained via the loader data.  */
  59   ULONGEST data_size = 0;
  60 };
  61
  62 /* This module's per-inferior data.  */
  63
  64 struct solib_aix_inferior_data
  65 {
  66   /* The list of shared libraries.
  67
  68      Note that the first element of this list is always the main
  69      executable, which is not technically a shared library.  But
  70      we need that information to perform its relocation, and
  71      the same principles applied to shared libraries also apply
  72      to the main executable.  So it's simpler to keep it as part
  73      of this list.  */
  74   gdb::optional<std::vector<lm_info_aix>> library_list;
  75 };
  76
  77 /* Key to our per-inferior data.  */
  78 static inferior_key<solib_aix_inferior_data> solib_aix_inferior_data_handle;
  79
  80 /* Return this module's data for the given inferior.
  81    If none is found, add a zero'ed one now.  */
  82
  83 static struct solib_aix_inferior_data *
  84 get_solib_aix_inferior_data (struct inferior *inf)
  85 {
  86   struct solib_aix_inferior_data *data;
  87
  88   data = solib_aix_inferior_data_handle.get (inf);
  89   if (data == NULL)
  90     data = solib_aix_inferior_data_handle.emplace (inf);
  91
  92   return data;
  93 }
  94
  95 #if !defined(HAVE_LIBEXPAT)
  96
  97 /* Dummy implementation if XML support is not compiled in.  */
  98
  99 static gdb::optional<std::vector<lm_info_aix>>
 100 solib_aix_parse_libraries (const char *library)
 101 {
 102   static int have_warned;
 103
 104   if (!have_warned)
 105     {
 106       have_warned = 1;
 107       warning (_("Can not parse XML library list; XML support was disabled "
 108                  "at compile time"));
 109     }
 110
 111   return {};
 112 }
 113
 114 #else /* HAVE_LIBEXPAT */
 115
 116 #include "xml-support.h"
 117
 118 /* Handle the start of a <library> element.  */
 119
 120 static void
 121 library_list_start_library (struct gdb_xml_parser *parser,
 122                             const struct gdb_xml_element *element,
 123                             void *user_data,
 124                             std::vector<gdb_xml_value> &attributes)
 125 {
 126   std::vector<lm_info_aix> *list = (std::vector<lm_info_aix> *) user_data;
 127   lm_info_aix item;
 128   struct gdb_xml_value *attr;
 129
 130   attr = xml_find_attribute (attributes, "name");
 131   item.filename = (const char *) attr->value.get ();
 132
 133   attr = xml_find_attribute (attributes, "member");
 134   if (attr != NULL)
 135     item.member_name = (const char *) attr->value.get ();
 136
 137   attr = xml_find_attribute (attributes, "text_addr");
 138   item.text_addr = * (ULONGEST *) attr->value.get ();
 139
 140   attr = xml_find_attribute (attributes, "text_size");
 141   item.text_size = * (ULONGEST *) attr->value.get ();
 142
 143   attr = xml_find_attribute (attributes, "data_addr");
 144   item.data_addr = * (ULONGEST *) attr->value.get ();
 145
 146   attr = xml_find_attribute (attributes, "data_size");
 147   item.data_size = * (ULONGEST *) attr->value.get ();
 148
 149   list->push_back (std::move (item));
 150 }
 151
 152 /* Handle the start of a <library-list-aix> element.  */
 153
 154 static void
 155 library_list_start_list (struct gdb_xml_parser *parser,
 156                          const struct gdb_xml_element *element,
 157                          void *user_data,
 158                          std::vector<gdb_xml_value> &attributes)
 159 {
 160   char *version
 161     = (char *) xml_find_attribute (attributes, "version")->value.get ();
 162
 163   if (strcmp (version, "1.0") != 0)
 164     gdb_xml_error (parser,
 165                    _("Library list has unsupported version \"%s\""),
 166                    version);
 167 }
 168
 169 /* The allowed elements and attributes for an AIX library list
 170    described in XML format.  The root element is a <library-list-aix>.  */
 171
 172 static const struct gdb_xml_attribute library_attributes[] =
 173 {
 174   { "name", GDB_XML_AF_NONE, NULL, NULL },
 175   { "member", GDB_XML_AF_OPTIONAL, NULL, NULL },
 176   { "text_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 177   { "text_size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 178   { "data_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 179   { "data_size", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
 180   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 181 };
 182
 183 static const struct gdb_xml_element library_list_children[] =
 184 {
 185   { "library", library_attributes, NULL,
 186     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
 187     library_list_start_library, NULL},
 188   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 189 };
 190
 191 static const struct gdb_xml_attribute library_list_attributes[] =
 192 {
 193   { "version", GDB_XML_AF_NONE, NULL, NULL },
 194   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 195 };
 196
 197 static const struct gdb_xml_element library_list_elements[] =
 198 {
 199   { "library-list-aix", library_list_attributes, library_list_children,
 200     GDB_XML_EF_NONE, library_list_start_list, NULL },
 201   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 202 };
 203
 204 /* Parse LIBRARY, a string containing the loader info in XML format,
 205    and return a vector of lm_info_aix objects.
 206
 207    Return an empty option if the parsing failed.  */
 208
 209 static gdb::optional<std::vector<lm_info_aix>>
 210 solib_aix_parse_libraries (const char *library)
 211 {
 212   std::vector<lm_info_aix> result;
 213
 214   if (gdb_xml_parse_quick (_("aix library list"), "library-list-aix.dtd",
 215                            library_list_elements, library, &result) == 0)
 216     return result;
 217
 218   return {};
 219 }
 220
 221 #endif /* HAVE_LIBEXPAT */
 222
 223 /* Return the loader info for the given inferior (INF), or an empty
 224    option if the list could not be computed.
 225
 226    Cache the result in per-inferior data, so as to avoid recomputing it
 227    each time this function is called.
 228
 229    If an error occurs while computing this list, and WARNING_MSG
 230    is not NULL, then print a warning including WARNING_MSG and
 231    a description of the error.  */
 232
 233 static gdb::optional<std::vector<lm_info_aix>> &
 234 solib_aix_get_library_list (struct inferior *inf, const char *warning_msg)
 235 {
 236   struct solib_aix_inferior_data *data;
 237
 238   /* If already computed, return the cached value.  */
 239   data = get_solib_aix_inferior_data (inf);
 240   if (data->library_list.has_value ())
 241     return data->library_list;
 242
 243   gdb::optional<gdb::char_vector> library_document
 244     = target_read_stralloc (current_top_target (), TARGET_OBJECT_LIBRARIES_AIX,
 245                             NULL);
 246   if (!library_document && warning_msg != NULL)
 247     {
 248       warning (_("%s (failed to read TARGET_OBJECT_LIBRARIES_AIX)"),
 249                warning_msg);
 250       return data->library_list;
 251     }
 252
 253   if (solib_aix_debug)
 254     fprintf_unfiltered (gdb_stdlog,
 255                         "DEBUG: TARGET_OBJECT_LIBRARIES_AIX = \n%s\n",
 256                         library_document->data ());
 257
 258   data->library_list = solib_aix_parse_libraries (library_document->data ());
 259   if (!data->library_list.has_value () && warning_msg != NULL)
 260     warning (_("%s (missing XML support?)"), warning_msg);
 261
 262   return data->library_list;
 263 }
 264
 265 /* If the .bss section's VMA is set to an address located before
 266    the end of the .data section, causing the two sections to overlap,
 267    return the overlap in bytes.  Otherwise, return zero.
 268
 269    Motivation:
 270
 271    The GNU linker sometimes sets the start address of the .bss session
 272    before the end of the .data section, making the 2 sections overlap.
 273    The loader appears to handle this situation gracefully, by simply
 274    loading the bss section right after the end of the .data section.
 275
 276    This means that the .data and the .bss sections are sometimes
 277    no longer relocated by the same amount.  The problem is that
 278    the ldinfo data does not contain any information regarding
 279    the relocation of the .bss section, assuming that it would be
 280    identical to the information provided for the .data section
 281    (this is what would normally happen if the program was linked
 282    correctly).
 283
 284    GDB therefore needs to detect those cases, and make the corresponding
 285    adjustment to the .bss section offset computed from the ldinfo data
 286    when necessary.  This function returns the adjustment amount  (or
 287    zero when no adjustment is needed).  */
 288
 289 static CORE_ADDR
 290 solib_aix_bss_data_overlap (bfd *abfd)
 291 {
 292   struct bfd_section *data_sect, *bss_sect;
 293
 294   data_sect = bfd_get_section_by_name (abfd, ".data");
 295   if (data_sect == NULL)
 296     return 0; /* No overlap possible.  */
 297
 298   bss_sect = bfd_get_section_by_name (abfd, ".bss");
 299   if (bss_sect == NULL)
 300     return 0; /* No overlap possible.  */
 301
 302   /* Assume the problem only occurs with linkers that place the .bss
 303      section after the .data section (the problem has only been
 304      observed when using the GNU linker, and the default linker
 305      script always places the .data and .bss sections in that order).  */
 306   if (bfd_section_vma (abfd, bss_sect)
 307       < bfd_section_vma (abfd, data_sect))
 308     return 0;
 309
 310   if (bfd_section_vma (abfd, bss_sect)
 311       < bfd_section_vma (abfd, data_sect) + bfd_get_section_size (data_sect))
 312     return ((bfd_section_vma (abfd, data_sect)
 313              + bfd_get_section_size (data_sect))
 314             - bfd_section_vma (abfd, bss_sect));
 315
 316   return 0;
 317 }
 318
 319 /* Implement the "relocate_section_addresses" target_so_ops method.  */
 320
 321 static void
 322 solib_aix_relocate_section_addresses (struct so_list *so,
 323                                       struct target_section *sec)
 324 {
 325   struct bfd_section *bfd_sect = sec->the_bfd_section;
 326   bfd *abfd = bfd_sect->owner;
 327   const char *section_name = bfd_section_name (abfd, bfd_sect);
 328   lm_info_aix *info = (lm_info_aix *) so->lm_info;
 329
 330   if (strcmp (section_name, ".text") == 0)
 331     {
 332       sec->addr = info->text_addr;
 333       sec->endaddr = sec->addr + info->text_size;
 334
 335       /* The text address given to us by the loader contains
 336          XCOFF headers, so we need to adjust by this much.  */
 337       sec->addr += bfd_sect->filepos;
 338     }
 339   else if (strcmp (section_name, ".data") == 0)
 340     {
 341       sec->addr = info->data_addr;
 342       sec->endaddr = sec->addr + info->data_size;
 343     }
 344   else if (strcmp (section_name, ".bss") == 0)
 345     {
 346       /* The information provided by the loader does not include
 347          the address of the .bss section, but we know that it gets
 348          relocated by the same offset as the .data section.  So,
 349          compute the relocation offset for the .data section, and
 350          apply it to the .bss section as well.  If the .data section
 351          is not defined (which seems highly unlikely), do our best
 352          by assuming no relocation.  */
 353       struct bfd_section *data_sect
 354         = bfd_get_section_by_name (abfd, ".data");
 355       CORE_ADDR data_offset = 0;
 356
 357       if (data_sect != NULL)
 358         data_offset = info->data_addr - bfd_section_vma (abfd, data_sect);
 359
 360       sec->addr = bfd_section_vma (abfd, bfd_sect) + data_offset;
 361       sec->addr += solib_aix_bss_data_overlap (abfd);
 362       sec->endaddr = sec->addr + bfd_section_size (abfd, bfd_sect);
 363     }
 364   else
 365     {
 366       /* All other sections should not be relocated.  */
 367       sec->addr = bfd_section_vma (abfd, bfd_sect);
 368       sec->endaddr = sec->addr + bfd_section_size (abfd, bfd_sect);
 369     }
 370 }
 371
 372 /* Implement the "free_so" target_so_ops method.  */
 373
 374 static void
 375 solib_aix_free_so (struct so_list *so)
 376 {
 377   lm_info_aix *li = (lm_info_aix *) so->lm_info;
 378
 379   if (solib_aix_debug)
 380     fprintf_unfiltered (gdb_stdlog, "DEBUG: solib_aix_free_so (%s)\n",
 381                         so->so_name);
 382
 383   delete li;
 384 }
 385
 386 /* Implement the "clear_solib" target_so_ops method.  */
 387
 388 static void
 389 solib_aix_clear_solib (void)
 390 {
 391   /* Nothing needed.  */
 392 }
 393
 394 /* Compute and return the OBJFILE's section_offset array, using
 395    the associated loader info (INFO).
 396
 397    The resulting array is computed on the heap and must be
 398    deallocated after use.  */
 399
 400 static gdb::unique_xmalloc_ptr<struct section_offsets>
 401 solib_aix_get_section_offsets (struct objfile *objfile,
 402                                lm_info_aix *info)
 403 {
 404   bfd *abfd = objfile->obfd;
 405
 406   gdb::unique_xmalloc_ptr<struct section_offsets> offsets
 407     (XCNEWVEC (struct section_offsets, objfile->num_sections));
 408
 409   /* .text */
 410
 411   if (objfile->sect_index_text != -1)
 412     {
 413       struct bfd_section *sect
 414         = objfile->sections[objfile->sect_index_text].the_bfd_section;
 415
 416       offsets->offsets[objfile->sect_index_text]
 417         = info->text_addr + sect->filepos - bfd_section_vma (abfd, sect);
 418     }
 419
 420   /* .data */
 421
 422   if (objfile->sect_index_data != -1)
 423     {
 424       struct bfd_section *sect
 425         = objfile->sections[objfile->sect_index_data].the_bfd_section;
 426
 427       offsets->offsets[objfile->sect_index_data]
 428         = info->data_addr - bfd_section_vma (abfd, sect);
 429     }
 430
 431   /* .bss
 432
 433      The offset of the .bss section should be identical to the offset
 434      of the .data section.  If no .data section (which seems hard to
 435      believe it is possible), assume it is zero.  */
 436
 437   if (objfile->sect_index_bss != -1
 438       && objfile->sect_index_data != -1)
 439     {
 440       offsets->offsets[objfile->sect_index_bss]
 441         = (offsets->offsets[objfile->sect_index_data]
 442            + solib_aix_bss_data_overlap (abfd));
 443     }
 444
 445   /* All other sections should not need relocation.  */
 446
 447   return offsets;
 448 }
 449
 450 /* Implement the "solib_create_inferior_hook" target_so_ops method.  */
 451
 452 static void
 453 solib_aix_solib_create_inferior_hook (int from_tty)
 454 {
 455   const char *warning_msg = "unable to relocate main executable";
 456
 457   /* We need to relocate the main executable...  */
 458
 459   gdb::optional<std::vector<lm_info_aix>> &library_list
 460     = solib_aix_get_library_list (current_inferior (), warning_msg);
 461   if (!library_list.has_value ())
 462     return;  /* Warning already printed.  */
 463
 464   if (library_list->empty ())
 465     {
 466       warning (_("unable to relocate main executable (no info from loader)"));
 467       return;
 468     }
 469
 470   lm_info_aix &exec_info = (*library_list)[0];
 471   if (symfile_objfile != NULL)
 472     {
 473       gdb::unique_xmalloc_ptr<struct section_offsets> offsets
 474         = solib_aix_get_section_offsets (symfile_objfile, &exec_info);
 475
 476       objfile_relocate (symfile_objfile, offsets.get ());
 477     }
 478 }
 479
 480 /* Implement the "current_sos" target_so_ops method.  */
 481
 482 static struct so_list *
 483 solib_aix_current_sos (void)
 484 {
 485   struct so_list *start = NULL, *last = NULL;
 486   int ix;
 487
 488   gdb::optional<std::vector<lm_info_aix>> &library_list
 489     = solib_aix_get_library_list (current_inferior (), NULL);
 490   if (!library_list.has_value ())
 491     return NULL;
 492
 493   /* Build a struct so_list for each entry on the list.
 494      We skip the first entry, since this is the entry corresponding
 495      to the main executable, not a shared library.  */
 496   for (ix = 1; ix < library_list->size (); ix++)
 497     {
 498       struct so_list *new_solib = XCNEW (struct so_list);
 499       std::string so_name;
 500
 501       lm_info_aix &info = (*library_list)[ix];
 502       if (info.member_name.empty ())
 503         {
 504          /* INFO.FILENAME is probably not an archive, but rather
 505             a shared object.  Unusual, but it should be possible
 506             to link a program against a shared object directory,
 507             without having to put it in an archive first.  */
 508          so_name = info.filename;
 509         }
 510       else
 511         {
 512          /* This is the usual case on AIX, where the shared object
 513             is a member of an archive.  Create a synthetic so_name
 514             that follows the same convention as AIX's ldd tool
 515             (Eg: "/lib/libc.a(shr.o)").  */
 516          so_name = string_printf ("%s(%s)", info.filename.c_str (),
 517                                   info.member_name.c_str ());
 518         }
 519       strncpy (new_solib->so_original_name, so_name.c_str (),
 520                SO_NAME_MAX_PATH_SIZE - 1);
 521       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 522       memcpy (new_solib->so_name, new_solib->so_original_name,
 523               SO_NAME_MAX_PATH_SIZE);
 524       new_solib->lm_info = new lm_info_aix (info);
 525
 526       /* Add it to the list.  */
 527       if (!start)
 528         last = start = new_solib;
 529       else
 530         {
 531           last->next = new_solib;
 532           last = new_solib;
 533         }
 534     }
 535
 536   return start;
 537 }
 538
 539 /* Implement the "open_symbol_file_object" target_so_ops method.  */
 540
 541 static int
 542 solib_aix_open_symbol_file_object (int from_tty)
 543 {
 544   return 0;
 545 }
 546
 547 /* Implement the "in_dynsym_resolve_code" target_so_ops method.  */
 548
 549 static int
 550 solib_aix_in_dynsym_resolve_code (CORE_ADDR pc)
 551 {
 552   return 0;
 553 }
 554
 555 /* Implement the "bfd_open" target_so_ops method.  */
 556
 557 static gdb_bfd_ref_ptr
 558 solib_aix_bfd_open (const char *pathname)
 559 {
 560   /* The pathname is actually a synthetic filename with the following
 561      form: "/path/to/sharedlib(member.o)" (double-quotes excluded).
 562      split this into archive name and member name.
 563
 564      FIXME: This is a little hacky.  Perhaps we should provide access
 565      to the solib's lm_info here?  */
 566   const int path_len = strlen (pathname);
 567   const char *sep;
 568   int filename_len;
 569   int found_file;
 570
 571   if (pathname[path_len - 1] != ')')
 572     return solib_bfd_open (pathname);
 573
 574   /* Search for the associated parens.  */
 575   sep = strrchr (pathname, '(');
 576   if (sep == NULL)
 577     {
 578       /* Should never happen, but recover as best as we can (trying
 579          to open pathname without decoding, possibly leading to
 580          a failure), rather than triggering an assert failure).  */
 581       warning (_("missing '(' in shared object pathname: %s"), pathname);
 582       return solib_bfd_open (pathname);
 583     }
 584   filename_len = sep - pathname;
 585
 586   std::string filename (string_printf ("%.*s", filename_len, pathname));
 587   std::string member_name (string_printf ("%.*s", path_len - filename_len - 2,
 588                                           sep + 1));
 589
 590   /* Calling solib_find makes certain that sysroot path is set properly
 591      if program has a dependency on .a archive and sysroot is set via
 592      set sysroot command.  */
 593   gdb::unique_xmalloc_ptr<char> found_pathname
 594     = solib_find (filename.c_str (), &found_file);
 595   if (found_pathname == NULL)
 596       perror_with_name (pathname);
 597   gdb_bfd_ref_ptr archive_bfd (solib_bfd_fopen (found_pathname.get (),
 598                                                 found_file));
 599   if (archive_bfd == NULL)
 600     {
 601       warning (_("Could not open `%s' as an executable file: %s"),
 602                filename.c_str (), bfd_errmsg (bfd_get_error ()));
 603       return NULL;
 604     }
 605
 606   if (bfd_check_format (archive_bfd.get (), bfd_object))
 607     return archive_bfd;
 608
 609   if (! bfd_check_format (archive_bfd.get (), bfd_archive))
 610     {
 611       warning (_("\"%s\": not in executable format: %s."),
 612                filename.c_str (), bfd_errmsg (bfd_get_error ()));
 613       return NULL;
 614     }
 615
 616   gdb_bfd_ref_ptr object_bfd
 617     (gdb_bfd_openr_next_archived_file (archive_bfd.get (), NULL));
 618   while (object_bfd != NULL)
 619     {
 620       if (member_name == object_bfd->filename)
 621         break;
 622
 623       object_bfd = gdb_bfd_openr_next_archived_file (archive_bfd.get (),
 624                                                      object_bfd.get ());
 625     }
 626
 627   if (object_bfd == NULL)
 628     {
 629       warning (_("\"%s\": member \"%s\" missing."), filename.c_str (),
 630                member_name.c_str ());
 631       return NULL;
 632     }
 633
 634   if (! bfd_check_format (object_bfd.get (), bfd_object))
 635     {
 636       warning (_("%s(%s): not in object format: %s."),
 637                filename.c_str (), member_name.c_str (),
 638                bfd_errmsg (bfd_get_error ()));
 639       return NULL;
 640     }
 641
 642   /* Override the returned bfd's name with the name returned from solib_find
 643      along with appended parenthesized member name in order to allow commands
 644      listing all shared libraries to display.  Otherwise, we would only be
 645      displaying the name of the archive member object.  */
 646   bfd_set_filename (object_bfd.get (),
 647                     xstrprintf ("%s%s",
 648                                 bfd_get_filename (archive_bfd.get ()),
 649                                 sep));
 650
 651   return object_bfd;
 652 }
 653
 654 /* Return the obj_section corresponding to OBJFILE's data section,
 655    or NULL if not found.  */
 656 /* FIXME: Define in a more general location? */
 657
 658 static struct obj_section *
 659 data_obj_section_from_objfile (struct objfile *objfile)
 660 {
 661   struct obj_section *osect;
 662
 663   ALL_OBJFILE_OSECTIONS (objfile, osect)
 664     if (strcmp (bfd_section_name (objfile->obfd, osect->the_bfd_section),
 665                 ".data") == 0)
 666       return osect;
 667
 668   return NULL;
 669 }
 670
 671 /* Return the TOC value corresponding to the given PC address,
 672    or raise an error if the value could not be determined.  */
 673
 674 CORE_ADDR
 675 solib_aix_get_toc_value (CORE_ADDR pc)
 676 {
 677   struct obj_section *pc_osect = find_pc_section (pc);
 678   struct obj_section *data_osect;
 679   CORE_ADDR result;
 680
 681   if (pc_osect == NULL)
 682     error (_("unable to find TOC entry for pc %s "
 683              "(no section contains this PC)"),
 684            core_addr_to_string (pc));
 685
 686   data_osect = data_obj_section_from_objfile (pc_osect->objfile);
 687   if (data_osect == NULL)
 688     error (_("unable to find TOC entry for pc %s "
 689              "(%s has no data section)"),
 690            core_addr_to_string (pc), objfile_name (pc_osect->objfile));
 691
 692   result = (obj_section_addr (data_osect)
 693             + xcoff_get_toc_offset (pc_osect->objfile));
 694   if (solib_aix_debug)
 695     fprintf_unfiltered (gdb_stdlog,
 696                         "DEBUG: solib_aix_get_toc_value (pc=%s) -> %s\n",
 697                         core_addr_to_string (pc),
 698                         core_addr_to_string (result));
 699
 700   return result;
 701 }
 702
 703 /* This module's normal_stop observer.  */
 704
 705 static void
 706 solib_aix_normal_stop_observer (struct bpstats *unused_1, int unused_2)
 707 {
 708   struct solib_aix_inferior_data *data
 709     = get_solib_aix_inferior_data (current_inferior ());
 710
 711   /* The inferior execution has been resumed, and it just stopped
 712      again.  This means that the list of shared libraries may have
 713      evolved.  Reset our cached value.  */
 714   data->library_list.reset ();
 715 }
 716
 717 /* Implements the "show debug aix-solib" command.  */
 718
 719 static void
 720 show_solib_aix_debug (struct ui_file *file, int from_tty,
 721                       struct cmd_list_element *c, const char *value)
 722 {
 723   fprintf_filtered (file, _("solib-aix debugging is %s.\n"), value);
 724 }
 725
 726 /* The target_so_ops for AIX targets.  */
 727 struct target_so_ops solib_aix_so_ops;
 728
 729 void
 730 _initialize_solib_aix (void)
 731 {
 732   solib_aix_so_ops.relocate_section_addresses
 733     = solib_aix_relocate_section_addresses;
 734   solib_aix_so_ops.free_so = solib_aix_free_so;
 735   solib_aix_so_ops.clear_solib = solib_aix_clear_solib;
 736   solib_aix_so_ops.solib_create_inferior_hook
 737     = solib_aix_solib_create_inferior_hook;
 738   solib_aix_so_ops.current_sos = solib_aix_current_sos;
 739   solib_aix_so_ops.open_symbol_file_object
 740     = solib_aix_open_symbol_file_object;
 741   solib_aix_so_ops.in_dynsym_resolve_code
 742     = solib_aix_in_dynsym_resolve_code;
 743   solib_aix_so_ops.bfd_open = solib_aix_bfd_open;
 744
 745   gdb::observers::normal_stop.attach (solib_aix_normal_stop_observer);
 746
 747   /* Debug this file's internals.  */
 748   add_setshow_boolean_cmd ("aix-solib", class_maintenance,
 749                            &solib_aix_debug, _("\
 750 Control the debugging traces for the solib-aix module."), _("\
 751 Show whether solib-aix debugging traces are enabled."), _("\
 752 When on, solib-aix debugging traces are enabled."),
 753                             NULL,
 754                             show_solib_aix_debug,
 755                             &setdebuglist, &showdebuglist);
 756 }