gdb/solib-darwin.c

   1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
   2
   3    Copyright (C) 2009-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21
  22 #include "symtab.h"
  23 #include "bfd.h"
  24 #include "symfile.h"
  25 #include "objfiles.h"
  26 #include "gdbcore.h"
  27 #include "target.h"
  28 #include "inferior.h"
  29 #include "regcache.h"
  30 #include "gdbthread.h"
  31 #include "gdb_bfd.h"
  32
  33 #include "solist.h"
  34 #include "solib.h"
  35 #include "solib-svr4.h"
  36
  37 #include "bfd-target.h"
  38 #include "elf-bfd.h"
  39 #include "exec.h"
  40 #include "auxv.h"
  41 #include "mach-o.h"
  42 #include "mach-o/external.h"
  43
  44 struct gdb_dyld_image_info
  45 {
  46   /* Base address (which corresponds to the Mach-O header).  */
  47   CORE_ADDR mach_header;
  48   /* Image file path.  */
  49   CORE_ADDR file_path;
  50   /* st.m_time of image file.  */
  51   unsigned long mtime;
  52 };
  53
  54 /* Content of inferior dyld_all_image_infos structure.
  55    See /usr/include/mach-o/dyld_images.h for the documentation.  */
  56 struct gdb_dyld_all_image_infos
  57 {
  58   /* Version (1).  */
  59   unsigned int version;
  60   /* Number of images.  */
  61   unsigned int count;
  62   /* Image description.  */
  63   CORE_ADDR info;
  64   /* Notifier (function called when a library is added or removed).  */
  65   CORE_ADDR notifier;
  66 };
  67
  68 /* Current all_image_infos version.  */
  69 #define DYLD_VERSION_MIN 1
  70 #define DYLD_VERSION_MAX 15
  71
  72 /* Per PSPACE specific data.  */
  73 struct darwin_info
  74 {
  75   /* Address of structure dyld_all_image_infos in inferior.  */
  76   CORE_ADDR all_image_addr;
  77
  78   /* Gdb copy of dyld_all_info_infos.  */
  79   struct gdb_dyld_all_image_infos all_image;
  80 };
  81
  82 /* Per-program-space data key.  */
  83 static const struct program_space_data *solib_darwin_pspace_data;
  84
  85 static void
  86 darwin_pspace_data_cleanup (struct program_space *pspace, void *arg)
  87 {
  88   xfree (arg);
  89 }
  90
  91 /* Get the current darwin data.  If none is found yet, add it now.  This
  92    function always returns a valid object.  */
  93
  94 static struct darwin_info *
  95 get_darwin_info (void)
  96 {
  97   struct darwin_info *info;
  98
  99   info = (struct darwin_info *) program_space_data (current_program_space,
 100                                                     solib_darwin_pspace_data);
 101   if (info != NULL)
 102     return info;
 103
 104   info = XCNEW (struct darwin_info);
 105   set_program_space_data (current_program_space,
 106                           solib_darwin_pspace_data, info);
 107   return info;
 108 }
 109
 110 /* Return non-zero if the version in dyld_all_image is known.  */
 111
 112 static int
 113 darwin_dyld_version_ok (const struct darwin_info *info)
 114 {
 115   return info->all_image.version >= DYLD_VERSION_MIN
 116     && info->all_image.version <= DYLD_VERSION_MAX;
 117 }
 118
 119 /* Read dyld_all_image from inferior.  */
 120
 121 static void
 122 darwin_load_image_infos (struct darwin_info *info)
 123 {
 124   gdb_byte buf[24];
 125   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
 126   struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
 127   int len;
 128
 129   /* If the structure address is not known, don't continue.  */
 130   if (info->all_image_addr == 0)
 131     return;
 132
 133   /* The structure has 4 fields: version (4 bytes), count (4 bytes),
 134      info (pointer) and notifier (pointer).  */
 135   len = 4 + 4 + 2 * TYPE_LENGTH (ptr_type);
 136   gdb_assert (len <= sizeof (buf));
 137   memset (&info->all_image, 0, sizeof (info->all_image));
 138
 139   /* Read structure raw bytes from target.  */
 140   if (target_read_memory (info->all_image_addr, buf, len))
 141     return;
 142
 143   /* Extract the fields.  */
 144   info->all_image.version = extract_unsigned_integer (buf, 4, byte_order);
 145   if (!darwin_dyld_version_ok (info))
 146     return;
 147
 148   info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order);
 149   info->all_image.info = extract_typed_address (buf + 8, ptr_type);
 150   info->all_image.notifier = extract_typed_address
 151     (buf + 8 + TYPE_LENGTH (ptr_type), ptr_type);
 152 }
 153
 154 /* Link map info to include in an allocated so_list entry.  */
 155
 156 struct lm_info_darwin : public lm_info_base
 157 {
 158   /* The target location of lm.  */
 159   CORE_ADDR lm_addr = 0;
 160 };
 161
 162 /* Lookup the value for a specific symbol.  */
 163
 164 static CORE_ADDR
 165 lookup_symbol_from_bfd (bfd *abfd, const char *symname)
 166 {
 167   long storage_needed;
 168   asymbol **symbol_table;
 169   unsigned int number_of_symbols;
 170   unsigned int i;
 171   CORE_ADDR symaddr = 0;
 172
 173   storage_needed = bfd_get_symtab_upper_bound (abfd);
 174
 175   if (storage_needed <= 0)
 176     return 0;
 177
 178   symbol_table = (asymbol **) xmalloc (storage_needed);
 179   number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
 180
 181   for (i = 0; i < number_of_symbols; i++)
 182     {
 183       asymbol *sym = symbol_table[i];
 184
 185       if (strcmp (sym->name, symname) == 0
 186           && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
 187         {
 188           /* BFD symbols are section relative.  */
 189           symaddr = sym->value + sym->section->vma;
 190           break;
 191         }
 192     }
 193   xfree (symbol_table);
 194
 195   return symaddr;
 196 }
 197
 198 /* Return program interpreter string.  */
 199
 200 static char *
 201 find_program_interpreter (void)
 202 {
 203   char *buf = NULL;
 204
 205   /* If we have an exec_bfd, get the interpreter from the load commands.  */
 206   if (exec_bfd)
 207     {
 208       bfd_mach_o_load_command *cmd;
 209
 210       if (bfd_mach_o_lookup_command (exec_bfd,
 211                                      BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1)
 212         return cmd->command.dylinker.name_str;
 213     }
 214
 215   /* If we didn't find it, read from memory.
 216      FIXME: todo.  */
 217   return buf;
 218 }
 219
 220 /*  Not used.  I don't see how the main symbol file can be found: the
 221     interpreter name is needed and it is known from the executable file.
 222     Note that darwin-nat.c implements pid_to_exec_file.  */
 223
 224 static int
 225 open_symbol_file_object (int from_tty)
 226 {
 227   return 0;
 228 }
 229
 230 /* Build a list of currently loaded shared objects.  See solib-svr4.c.  */
 231
 232 static struct so_list *
 233 darwin_current_sos (void)
 234 {
 235   struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
 236   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
 237   int ptr_len = TYPE_LENGTH (ptr_type);
 238   unsigned int image_info_size;
 239   struct so_list *head = NULL;
 240   struct so_list *tail = NULL;
 241   int i;
 242   struct darwin_info *info = get_darwin_info ();
 243
 244   /* Be sure image infos are loaded.  */
 245   darwin_load_image_infos (info);
 246
 247   if (!darwin_dyld_version_ok (info))
 248     return NULL;
 249
 250   image_info_size = ptr_len * 3;
 251
 252   /* Read infos for each solib.
 253      The first entry was rumored to be the executable itself, but this is not
 254      true when a large number of shared libraries are used (table expanded ?).
 255      We now check all entries, but discard executable images.  */
 256   for (i = 0; i < info->all_image.count; i++)
 257     {
 258       CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
 259       gdb_byte buf[image_info_size];
 260       CORE_ADDR load_addr;
 261       CORE_ADDR path_addr;
 262       struct mach_o_header_external hdr;
 263       unsigned long hdr_val;
 264       gdb::unique_xmalloc_ptr<char> file_path;
 265       int errcode;
 266
 267       /* Read image info from inferior.  */
 268       if (target_read_memory (iinfo, buf, image_info_size))
 269         break;
 270
 271       load_addr = extract_typed_address (buf, ptr_type);
 272       path_addr = extract_typed_address (buf + ptr_len, ptr_type);
 273
 274       /* Read Mach-O header from memory.  */
 275       if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
 276         break;
 277       /* Discard wrong magic numbers.  Shouldn't happen.  */
 278       hdr_val = extract_unsigned_integer
 279         (hdr.magic, sizeof (hdr.magic), byte_order);
 280       if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
 281         continue;
 282       /* Discard executable.  Should happen only once.  */
 283       hdr_val = extract_unsigned_integer
 284         (hdr.filetype, sizeof (hdr.filetype), byte_order);
 285       if (hdr_val == BFD_MACH_O_MH_EXECUTE)
 286         continue;
 287
 288       target_read_string (path_addr, &file_path,
 289                           SO_NAME_MAX_PATH_SIZE - 1, &errcode);
 290       if (errcode)
 291         break;
 292
 293       /* Create and fill the new so_list element.  */
 294       gdb::unique_xmalloc_ptr<struct so_list> newobj (XCNEW (struct so_list));
 295
 296       lm_info_darwin *li = new lm_info_darwin;
 297       newobj->lm_info = li;
 298
 299       strncpy (newobj->so_name, file_path.get (), SO_NAME_MAX_PATH_SIZE - 1);
 300       newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
 301       strcpy (newobj->so_original_name, newobj->so_name);
 302       li->lm_addr = load_addr;
 303
 304       if (head == NULL)
 305         head = newobj.get ();
 306       else
 307         tail->next = newobj.get ();
 308       tail = newobj.release ();
 309     }
 310
 311   return head;
 312 }
 313
 314 /* Check LOAD_ADDR points to a Mach-O executable header.  Return LOAD_ADDR
 315    in case of success, 0 in case of failure.  */
 316
 317 static CORE_ADDR
 318 darwin_validate_exec_header (CORE_ADDR load_addr)
 319 {
 320   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
 321   struct mach_o_header_external hdr;
 322   unsigned long hdr_val;
 323
 324   /* Read Mach-O header from memory.  */
 325   if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4))
 326     return 0;
 327
 328   /* Discard wrong magic numbers.  Shouldn't happen.  */
 329   hdr_val = extract_unsigned_integer
 330     (hdr.magic, sizeof (hdr.magic), byte_order);
 331   if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
 332     return 0;
 333
 334   /* Check executable.  */
 335   hdr_val = extract_unsigned_integer
 336     (hdr.filetype, sizeof (hdr.filetype), byte_order);
 337   if (hdr_val == BFD_MACH_O_MH_EXECUTE)
 338     return load_addr;
 339
 340   return 0;
 341 }
 342
 343 /* Get the load address of the executable using dyld list of images.
 344    We assume that the dyld info are correct (which is wrong if the target
 345    is stopped at the first instruction).  */
 346
 347 static CORE_ADDR
 348 darwin_read_exec_load_addr_from_dyld (struct darwin_info *info)
 349 {
 350   struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
 351   int ptr_len = TYPE_LENGTH (ptr_type);
 352   unsigned int image_info_size = ptr_len * 3;
 353   int i;
 354
 355   /* Read infos for each solib.  One of them should be the executable.  */
 356   for (i = 0; i < info->all_image.count; i++)
 357     {
 358       CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
 359       gdb_byte buf[image_info_size];
 360       CORE_ADDR load_addr;
 361
 362       /* Read image info from inferior.  */
 363       if (target_read_memory (iinfo, buf, image_info_size))
 364         break;
 365
 366       load_addr = extract_typed_address (buf, ptr_type);
 367       if (darwin_validate_exec_header (load_addr) == load_addr)
 368         return load_addr;
 369     }
 370
 371   return 0;
 372 }
 373
 374 /* Get the load address of the executable when the PC is at the dyld
 375    entry point using parameter passed by the kernel (at SP). */
 376
 377 static CORE_ADDR
 378 darwin_read_exec_load_addr_at_init (struct darwin_info *info)
 379 {
 380   struct gdbarch *gdbarch = target_gdbarch ();
 381   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 382   int addr_size = gdbarch_addr_bit (gdbarch) / 8;
 383   ULONGEST load_ptr_addr;
 384   ULONGEST load_addr;
 385   gdb_byte buf[8];
 386
 387   /* Get SP.  */
 388   if (regcache_cooked_read_unsigned (get_current_regcache (),
 389                                      gdbarch_sp_regnum (gdbarch),
 390                                      &load_ptr_addr) != REG_VALID)
 391     return 0;
 392
 393   /* Read value at SP (image load address).  */
 394   if (target_read_memory (load_ptr_addr, buf, addr_size))
 395     return 0;
 396
 397   load_addr = extract_unsigned_integer (buf, addr_size, byte_order);
 398
 399   return darwin_validate_exec_header (load_addr);
 400 }
 401
 402 /* Return 1 if PC lies in the dynamic symbol resolution code of the
 403    run time loader.  */
 404
 405 static int
 406 darwin_in_dynsym_resolve_code (CORE_ADDR pc)
 407 {
 408   return 0;
 409 }
 410
 411 /* A wrapper for bfd_mach_o_fat_extract that handles reference
 412    counting properly.  This will either return NULL, or return a new
 413    reference to a BFD.  */
 414
 415 static gdb_bfd_ref_ptr
 416 gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format,
 417                             const bfd_arch_info_type *arch)
 418 {
 419   bfd *result = bfd_mach_o_fat_extract (abfd, format, arch);
 420
 421   if (result == NULL)
 422     return NULL;
 423
 424   if (result == abfd)
 425     gdb_bfd_ref (result);
 426   else
 427     gdb_bfd_mark_parent (result, abfd);
 428
 429   return gdb_bfd_ref_ptr (result);
 430 }
 431
 432 /* Return the BFD for the program interpreter.  */
 433
 434 static gdb_bfd_ref_ptr
 435 darwin_get_dyld_bfd ()
 436 {
 437   char *interp_name;
 438
 439   /* This method doesn't work with an attached process.  */
 440   if (current_inferior ()->attach_flag)
 441     return NULL;
 442
 443   /* Find the program interpreter.  */
 444   interp_name = find_program_interpreter ();
 445   if (!interp_name)
 446     return NULL;
 447
 448   /* Create a bfd for the interpreter.  */
 449   gdb_bfd_ref_ptr dyld_bfd (gdb_bfd_open (interp_name, gnutarget, -1));
 450   if (dyld_bfd != NULL)
 451     {
 452       gdb_bfd_ref_ptr sub
 453         (gdb_bfd_mach_o_fat_extract (dyld_bfd.get (), bfd_object,
 454                                      gdbarch_bfd_arch_info (target_gdbarch ())));
 455       dyld_bfd = sub;
 456     }
 457   return dyld_bfd;
 458 }
 459
 460 /* Extract dyld_all_image_addr when the process was just created, assuming the
 461    current PC is at the entry of the dynamic linker.  */
 462
 463 static void
 464 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
 465 {
 466   CORE_ADDR load_addr = 0;
 467   gdb_bfd_ref_ptr dyld_bfd = darwin_get_dyld_bfd ();
 468
 469   if (dyld_bfd == NULL)
 470     return;
 471
 472   /* We find the dynamic linker's base address by examining
 473      the current pc (which should point at the entry point for the
 474      dynamic linker) and subtracting the offset of the entry point.  */
 475   load_addr = (regcache_read_pc (get_current_regcache ())
 476                - bfd_get_start_address (dyld_bfd.get ()));
 477
 478   /* Now try to set a breakpoint in the dynamic linker.  */
 479   info->all_image_addr =
 480     lookup_symbol_from_bfd (dyld_bfd.get (), "_dyld_all_image_infos");
 481
 482   if (info->all_image_addr == 0)
 483     return;
 484
 485   info->all_image_addr += load_addr;
 486 }
 487
 488 /* Extract dyld_all_image_addr reading it from
 489    TARGET_OBJECT_DARWIN_DYLD_INFO.  */
 490
 491 static void
 492 darwin_solib_read_all_image_info_addr (struct darwin_info *info)
 493 {
 494   gdb_byte buf[8];
 495   LONGEST len;
 496   struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
 497
 498   /* Sanity check.  */
 499   if (TYPE_LENGTH (ptr_type) > sizeof (buf))
 500     return;
 501
 502   len = target_read (current_top_target (), TARGET_OBJECT_DARWIN_DYLD_INFO,
 503                      NULL, buf, 0, TYPE_LENGTH (ptr_type));
 504   if (len <= 0)
 505     return;
 506
 507   /* The use of BIG endian is intended, as BUF is a raw stream of bytes.  This
 508       makes the support of remote protocol easier.  */
 509   info->all_image_addr = extract_unsigned_integer (buf, len, BFD_ENDIAN_BIG);
 510 }
 511
 512 /* Shared library startup support.  See documentation in solib-svr4.c.  */
 513
 514 static void
 515 darwin_solib_create_inferior_hook (int from_tty)
 516 {
 517   struct darwin_info *info = get_darwin_info ();
 518   CORE_ADDR load_addr;
 519
 520   info->all_image_addr = 0;
 521
 522   darwin_solib_read_all_image_info_addr (info);
 523
 524   if (info->all_image_addr == 0)
 525     darwin_solib_get_all_image_info_addr_at_init (info);
 526
 527   if (info->all_image_addr == 0)
 528     return;
 529
 530   darwin_load_image_infos (info);
 531
 532   if (!darwin_dyld_version_ok (info))
 533     {
 534       warning (_("unhandled dyld version (%d)"), info->all_image.version);
 535       return;
 536     }
 537
 538   if (info->all_image.count != 0)
 539     {
 540       /* Possible relocate the main executable (PIE).  */
 541       load_addr = darwin_read_exec_load_addr_from_dyld (info);
 542     }
 543   else
 544     {
 545       /* Possible issue:
 546          Do not break on the notifier if dyld is not initialized (deduced from
 547          count == 0).  In that case, dyld hasn't relocated itself and the
 548          notifier may point to a wrong address.  */
 549
 550       load_addr = darwin_read_exec_load_addr_at_init (info);
 551     }
 552
 553   if (load_addr != 0 && symfile_objfile != NULL)
 554     {
 555       CORE_ADDR vmaddr;
 556
 557       /* Find the base address of the executable.  */
 558       vmaddr = bfd_mach_o_get_base_address (exec_bfd);
 559
 560       /* Relocate.  */
 561       if (vmaddr != load_addr)
 562         objfile_rebase (symfile_objfile, load_addr - vmaddr);
 563     }
 564
 565   /* Set solib notifier (to reload list of shared libraries).  */
 566   CORE_ADDR notifier = info->all_image.notifier;
 567
 568   if (info->all_image.count == 0)
 569     {
 570       /* Dyld hasn't yet relocated itself, so the notifier address may
 571          be incorrect (as it has to be relocated).  */
 572       CORE_ADDR start = bfd_get_start_address (exec_bfd);
 573       if (start == 0)
 574         notifier = 0;
 575       else
 576         {
 577           gdb_bfd_ref_ptr dyld_bfd = darwin_get_dyld_bfd ();
 578           if (dyld_bfd != NULL)
 579             {
 580               CORE_ADDR dyld_bfd_start_address;
 581               CORE_ADDR dyld_relocated_base_address;
 582               CORE_ADDR pc;
 583
 584               dyld_bfd_start_address = bfd_get_start_address (dyld_bfd.get());
 585
 586               /* We find the dynamic linker's base address by examining
 587                  the current pc (which should point at the entry point
 588                  for the dynamic linker) and subtracting the offset of
 589                  the entry point.  */
 590
 591               pc = regcache_read_pc (get_current_regcache ());
 592               dyld_relocated_base_address = pc - dyld_bfd_start_address;
 593
 594               /* We get the proper notifier relocated address by
 595                  adding the dyld relocated base address to the current
 596                  notifier offset value.  */
 597
 598               notifier += dyld_relocated_base_address;
 599             }
 600         }
 601     }
 602
 603   /* Add the breakpoint which is hit by dyld when the list of solib is
 604      modified.  */
 605   if (notifier != 0)
 606     create_solib_event_breakpoint (target_gdbarch (), notifier);
 607 }
 608
 609 static void
 610 darwin_clear_solib (void)
 611 {
 612   struct darwin_info *info = get_darwin_info ();
 613
 614   info->all_image_addr = 0;
 615   info->all_image.version = 0;
 616 }
 617
 618 static void
 619 darwin_free_so (struct so_list *so)
 620 {
 621   lm_info_darwin *li = (lm_info_darwin *) so->lm_info;
 622
 623   delete li;
 624 }
 625
 626 /* The section table is built from bfd sections using bfd VMAs.
 627    Relocate these VMAs according to solib info.  */
 628
 629 static void
 630 darwin_relocate_section_addresses (struct so_list *so,
 631                                    struct target_section *sec)
 632 {
 633   lm_info_darwin *li = (lm_info_darwin *) so->lm_info;
 634
 635   sec->addr += li->lm_addr;
 636   sec->endaddr += li->lm_addr;
 637
 638   /* Best effort to set addr_high/addr_low.  This is used only by
 639      'info sharedlibary'.  */
 640   if (so->addr_high == 0)
 641     {
 642       so->addr_low = sec->addr;
 643       so->addr_high = sec->endaddr;
 644     }
 645   if (sec->endaddr > so->addr_high)
 646     so->addr_high = sec->endaddr;
 647   if (sec->addr < so->addr_low)
 648     so->addr_low = sec->addr;
 649 }
 650 \f
 651 static struct block_symbol
 652 darwin_lookup_lib_symbol (struct objfile *objfile,
 653                           const char *name,
 654                           const domain_enum domain)
 655 {
 656   return {};
 657 }
 658
 659 static gdb_bfd_ref_ptr
 660 darwin_bfd_open (const char *pathname)
 661 {
 662   int found_file;
 663
 664   /* Search for shared library file.  */
 665   gdb::unique_xmalloc_ptr<char> found_pathname
 666     = solib_find (pathname, &found_file);
 667   if (found_pathname == NULL)
 668     perror_with_name (pathname);
 669
 670   /* Open bfd for shared library.  */
 671   gdb_bfd_ref_ptr abfd (solib_bfd_fopen (found_pathname.get (), found_file));
 672
 673   gdb_bfd_ref_ptr res
 674     (gdb_bfd_mach_o_fat_extract (abfd.get (), bfd_object,
 675                                  gdbarch_bfd_arch_info (target_gdbarch ())));
 676   if (res == NULL)
 677     error (_("`%s': not a shared-library: %s"),
 678            bfd_get_filename (abfd.get ()), bfd_errmsg (bfd_get_error ()));
 679
 680   /* The current filename for fat-binary BFDs is a name generated
 681      by BFD, usually a string containing the name of the architecture.
 682      Reset its value to the actual filename.  */
 683   xfree (bfd_get_filename (res.get ()));
 684   res->filename = xstrdup (pathname);
 685
 686   return res;
 687 }
 688
 689 struct target_so_ops darwin_so_ops;
 690
 691 void
 692 _initialize_darwin_solib (void)
 693 {
 694   solib_darwin_pspace_data
 695     = register_program_space_data_with_cleanup (NULL,
 696                                                 darwin_pspace_data_cleanup);
 697
 698   darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses;
 699   darwin_so_ops.free_so = darwin_free_so;
 700   darwin_so_ops.clear_solib = darwin_clear_solib;
 701   darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook;
 702   darwin_so_ops.current_sos = darwin_current_sos;
 703   darwin_so_ops.open_symbol_file_object = open_symbol_file_object;
 704   darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
 705   darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
 706   darwin_so_ops.bfd_open = darwin_bfd_open;
 707 }