1 /* Handle Darwin shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2009-2012 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
30 #include "gdbthread.h"
33 #include "gdb_assert.h"
37 #include "solib-svr4.h"
39 #include "bfd-target.h"
43 #include "exceptions.h"
45 #include "mach-o/external.h"
47 struct gdb_dyld_image_info
49 /* Base address (which corresponds to the Mach-O header). */
50 CORE_ADDR mach_header;
51 /* Image file path. */
53 /* st.m_time of image file. */
57 /* Content of inferior dyld_all_image_infos structure.
58 See /usr/include/mach-o/dyld_images.h for the documentation. */
59 struct gdb_dyld_all_image_infos
63 /* Number of images. */
65 /* Image description. */
67 /* Notifier (function called when a library is added or removed). */
71 /* Current all_image_infos version. */
72 #define DYLD_VERSION_MIN 1
73 #define DYLD_VERSION_MAX 12
75 /* Per PSPACE specific data. */
78 /* Address of structure dyld_all_image_infos in inferior. */
79 CORE_ADDR all_image_addr;
81 /* Gdb copy of dyld_all_info_infos. */
82 struct gdb_dyld_all_image_infos all_image;
85 /* Per-program-space data key. */
86 static const struct program_space_data *solib_darwin_pspace_data;
89 darwin_pspace_data_cleanup (struct program_space *pspace, void *arg)
91 struct darwin_info *info;
93 info = program_space_data (pspace, solib_darwin_pspace_data);
97 /* Get the current darwin data. If none is found yet, add it now. This
98 function always returns a valid object. */
100 static struct darwin_info *
101 get_darwin_info (void)
103 struct darwin_info *info;
105 info = program_space_data (current_program_space, solib_darwin_pspace_data);
109 info = XZALLOC (struct darwin_info);
110 set_program_space_data (current_program_space,
111 solib_darwin_pspace_data, info);
115 /* Return non-zero if the version in dyld_all_image is known. */
118 darwin_dyld_version_ok (const struct darwin_info *info)
120 return info->all_image.version >= DYLD_VERSION_MIN
121 && info->all_image.version <= DYLD_VERSION_MAX;
124 /* Read dyld_all_image from inferior. */
127 darwin_load_image_infos (struct darwin_info *info)
130 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
131 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
134 /* If the structure address is not known, don't continue. */
135 if (info->all_image_addr == 0)
138 /* The structure has 4 fields: version (4 bytes), count (4 bytes),
139 info (pointer) and notifier (pointer). */
140 len = 4 + 4 + 2 * ptr_type->length;
141 gdb_assert (len <= sizeof (buf));
142 memset (&info->all_image, 0, sizeof (info->all_image));
144 /* Read structure raw bytes from target. */
145 if (target_read_memory (info->all_image_addr, buf, len))
148 /* Extract the fields. */
149 info->all_image.version = extract_unsigned_integer (buf, 4, byte_order);
150 if (!darwin_dyld_version_ok (info))
153 info->all_image.count = extract_unsigned_integer (buf + 4, 4, byte_order);
154 info->all_image.info = extract_typed_address (buf + 8, ptr_type);
155 info->all_image.notifier = extract_typed_address
156 (buf + 8 + ptr_type->length, ptr_type);
159 /* Link map info to include in an allocated so_list entry. */
163 /* The target location of lm. */
167 struct darwin_so_list
171 /* Darwin specific data. */
175 /* Lookup the value for a specific symbol. */
178 lookup_symbol_from_bfd (bfd *abfd, char *symname)
181 asymbol **symbol_table;
182 unsigned int number_of_symbols;
184 CORE_ADDR symaddr = 0;
186 storage_needed = bfd_get_symtab_upper_bound (abfd);
188 if (storage_needed <= 0)
191 symbol_table = (asymbol **) xmalloc (storage_needed);
192 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
194 for (i = 0; i < number_of_symbols; i++)
196 asymbol *sym = symbol_table[i];
198 if (strcmp (sym->name, symname) == 0
199 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
201 /* BFD symbols are section relative. */
202 symaddr = sym->value + sym->section->vma;
206 xfree (symbol_table);
211 /* Return program interpreter string. */
214 find_program_interpreter (void)
216 gdb_byte *buf = NULL;
218 /* If we have an exec_bfd, get the interpreter from the load commands. */
221 bfd_mach_o_load_command *cmd;
223 if (bfd_mach_o_lookup_command (exec_bfd,
224 BFD_MACH_O_LC_LOAD_DYLINKER, &cmd) == 1)
225 return cmd->command.dylinker.name_str;
228 /* If we didn't find it, read from memory.
233 /* Not used. I don't see how the main symbol file can be found: the
234 interpreter name is needed and it is known from the executable file.
235 Note that darwin-nat.c implements pid_to_exec_file. */
238 open_symbol_file_object (void *from_ttyp)
243 /* Build a list of currently loaded shared objects. See solib-svr4.c. */
245 static struct so_list *
246 darwin_current_sos (void)
248 struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
249 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
250 int ptr_len = TYPE_LENGTH (ptr_type);
251 unsigned int image_info_size;
252 struct so_list *head = NULL;
253 struct so_list *tail = NULL;
255 struct darwin_info *info = get_darwin_info ();
257 /* Be sure image infos are loaded. */
258 darwin_load_image_infos (info);
260 if (!darwin_dyld_version_ok (info))
263 image_info_size = ptr_len * 3;
265 /* Read infos for each solib.
266 The first entry was rumored to be the executable itself, but this is not
267 true when a large number of shared libraries are used (table expanded ?).
268 We now check all entries, but discard executable images. */
269 for (i = 0; i < info->all_image.count; i++)
271 CORE_ADDR iinfo = info->all_image.info + i * image_info_size;
272 char buf[image_info_size];
275 struct mach_o_header_external hdr;
276 unsigned long hdr_val;
279 struct darwin_so_list *dnew;
281 struct cleanup *old_chain;
283 /* Read image info from inferior. */
284 if (target_read_memory (iinfo, buf, image_info_size))
287 load_addr = extract_typed_address (buf, ptr_type);
288 path_addr = extract_typed_address (buf + ptr_len, ptr_type);
290 /* Read Mach-O header from memory. */
291 if (target_read_memory (load_addr, (char *) &hdr, sizeof (hdr) - 4))
293 /* Discard wrong magic numbers. Shouldn't happen. */
294 hdr_val = extract_unsigned_integer
295 (hdr.magic, sizeof (hdr.magic), byte_order);
296 if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64)
298 /* Discard executable. Should happen only once. */
299 hdr_val = extract_unsigned_integer
300 (hdr.filetype, sizeof (hdr.filetype), byte_order);
301 if (hdr_val == BFD_MACH_O_MH_EXECUTE)
304 target_read_string (path_addr, &file_path,
305 SO_NAME_MAX_PATH_SIZE - 1, &errcode);
309 /* Create and fill the new so_list element. */
310 dnew = XZALLOC (struct darwin_so_list);
312 old_chain = make_cleanup (xfree, dnew);
314 new->lm_info = &dnew->li;
316 strncpy (new->so_name, file_path, SO_NAME_MAX_PATH_SIZE - 1);
317 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
318 strcpy (new->so_original_name, new->so_name);
320 new->lm_info->lm_addr = load_addr;
328 discard_cleanups (old_chain);
334 /* Return 1 if PC lies in the dynamic symbol resolution code of the
338 darwin_in_dynsym_resolve_code (CORE_ADDR pc)
344 /* No special symbol handling. */
347 darwin_special_symbol_handling (void)
351 /* Extract dyld_all_image_addr when the process was just created, assuming the
352 current PC is at the entry of the dynamic linker. */
355 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
357 gdb_byte *interp_name;
358 CORE_ADDR load_addr = 0;
359 bfd *dyld_bfd = NULL;
360 struct cleanup *cleanup;
362 /* This method doesn't work with an attached process. */
363 if (current_inferior ()->attach_flag)
366 /* Find the program interpreter. */
367 interp_name = find_program_interpreter ();
371 cleanup = make_cleanup (null_cleanup, NULL);
373 /* Create a bfd for the interpreter. */
374 dyld_bfd = gdb_bfd_open (interp_name, gnutarget, -1);
379 make_cleanup_bfd_unref (dyld_bfd);
380 sub = bfd_mach_o_fat_extract (dyld_bfd, bfd_object,
381 gdbarch_bfd_arch_info (target_gdbarch ()));
386 make_cleanup_bfd_unref (sub);
393 do_cleanups (cleanup);
397 /* We find the dynamic linker's base address by examining
398 the current pc (which should point at the entry point for the
399 dynamic linker) and subtracting the offset of the entry point. */
400 load_addr = (regcache_read_pc (get_current_regcache ())
401 - bfd_get_start_address (dyld_bfd));
403 /* Now try to set a breakpoint in the dynamic linker. */
404 info->all_image_addr =
405 lookup_symbol_from_bfd (dyld_bfd, "_dyld_all_image_infos");
407 do_cleanups (cleanup);
409 if (info->all_image_addr == 0)
412 info->all_image_addr += load_addr;
415 /* Extract dyld_all_image_addr reading it from
416 TARGET_OBJECT_DARWIN_DYLD_INFO. */
419 darwin_solib_read_all_image_info_addr (struct darwin_info *info)
421 gdb_byte buf[8 + 8 + 4];
423 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
425 len = target_read (¤t_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL,
426 buf, 0, sizeof (buf));
427 if (len != sizeof (buf))
430 info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order);
433 /* Shared library startup support. See documentation in solib-svr4.c. */
436 darwin_solib_create_inferior_hook (int from_tty)
438 struct darwin_info *info = get_darwin_info ();
440 info->all_image_addr = 0;
442 darwin_solib_read_all_image_info_addr (info);
444 if (info->all_image_addr == 0)
445 darwin_solib_get_all_image_info_addr_at_init (info);
447 if (info->all_image_addr == 0)
450 darwin_load_image_infos (info);
452 if (darwin_dyld_version_ok (info))
453 create_solib_event_breakpoint (target_gdbarch (), info->all_image.notifier);
457 darwin_clear_solib (void)
459 struct darwin_info *info = get_darwin_info ();
461 info->all_image_addr = 0;
462 info->all_image.version = 0;
466 darwin_free_so (struct so_list *so)
470 /* The section table is built from bfd sections using bfd VMAs.
471 Relocate these VMAs according to solib info. */
474 darwin_relocate_section_addresses (struct so_list *so,
475 struct target_section *sec)
477 sec->addr += so->lm_info->lm_addr;
478 sec->endaddr += so->lm_info->lm_addr;
480 /* Best effort to set addr_high/addr_low. This is used only by
481 'info sharedlibary'. */
482 if (so->addr_high == 0)
484 so->addr_low = sec->addr;
485 so->addr_high = sec->endaddr;
487 if (sec->endaddr > so->addr_high)
488 so->addr_high = sec->endaddr;
489 if (sec->addr < so->addr_low)
490 so->addr_low = sec->addr;
493 static struct symbol *
494 darwin_lookup_lib_symbol (const struct objfile *objfile,
496 const domain_enum domain)
502 darwin_bfd_open (char *pathname)
504 char *found_pathname;
509 /* Search for shared library file. */
510 found_pathname = solib_find (pathname, &found_file);
511 if (found_pathname == NULL)
512 perror_with_name (pathname);
514 /* Open bfd for shared library. */
515 abfd = solib_bfd_fopen (found_pathname, found_file);
517 res = bfd_mach_o_fat_extract (abfd, bfd_object,
518 gdbarch_bfd_arch_info (target_gdbarch ()));
521 make_cleanup_bfd_unref (abfd);
522 error (_("`%s': not a shared-library: %s"),
523 bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
528 struct target_so_ops darwin_so_ops;
530 /* -Wmissing-prototypes */
531 extern initialize_file_ftype _initialize_darwin_solib;
534 _initialize_darwin_solib (void)
536 solib_darwin_pspace_data
537 = register_program_space_data_with_cleanup (NULL,
538 darwin_pspace_data_cleanup);
540 darwin_so_ops.relocate_section_addresses = darwin_relocate_section_addresses;
541 darwin_so_ops.free_so = darwin_free_so;
542 darwin_so_ops.clear_solib = darwin_clear_solib;
543 darwin_so_ops.solib_create_inferior_hook = darwin_solib_create_inferior_hook;
544 darwin_so_ops.special_symbol_handling = darwin_special_symbol_handling;
545 darwin_so_ops.current_sos = darwin_current_sos;
546 darwin_so_ops.open_symbol_file_object = open_symbol_file_object;
547 darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
548 darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
549 darwin_so_ops.bfd_open = darwin_bfd_open;