1 /* Definitions for BFD wrappers used by GDB.
3 Copyright (C) 2011, 2012
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "gdb_assert.h"
24 #include "gdb_string.h"
34 #define MAP_FAILED ((void *) -1)
38 /* An object of this type is stored in the section's user data when
41 struct gdb_bfd_section_data
43 /* Size of the data. */
45 /* If the data was mmapped, this is the length of the map. */
46 bfd_size_type map_len;
47 /* The data. If NULL, the section data has not been read. */
49 /* If the data was mmapped, this is the map address. */
53 /* A hash table holding every BFD that gdb knows about. This is not
54 to be confused with 'gdb_bfd_cache', which is used for sharing
55 BFDs; in contrast, this hash is used just to implement
58 static htab_t all_bfds;
63 gdb_bfd_stash_filename (struct bfd *abfd)
65 char *name = bfd_get_filename (abfd);
68 data = bfd_alloc (abfd, strlen (name) + 1);
71 /* Unwarranted chumminess with BFD. */
72 abfd->filename = data;
75 /* An object of this type is stored in each BFD's user data. */
79 /* The reference count. */
82 /* The mtime of the BFD at the point the cache entry was made. */
85 /* If the BFD comes from an archive, this points to the archive's
86 BFD. Otherwise, this is NULL. */
93 #define GDB_BFD_DATA_ACCESSOR(ABFD) \
94 ((struct gdb_bfd_data *) bfd_usrdata (ABFD))
96 DEFINE_REGISTRY (bfd, GDB_BFD_DATA_ACCESSOR)
98 /* A hash table storing all the BFDs maintained in the cache. */
100 static htab_t gdb_bfd_cache;
102 /* The type of an object being looked up in gdb_bfd_cache. We use
103 htab's capability of storing one kind of object (BFD in this case)
104 and using a different sort of object for searching. */
106 struct gdb_bfd_cache_search
109 const char *filename;
114 /* A hash function for BFDs. */
117 hash_bfd (const void *b)
121 /* It is simplest to just hash the filename. */
122 return htab_hash_string (bfd_get_filename (abfd));
125 /* An equality function for BFDs. Note that this expects the caller
126 to search using struct gdb_bfd_cache_search only, not BFDs. */
129 eq_bfd (const void *a, const void *b)
132 const struct gdb_bfd_cache_search *s = b;
133 struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
135 return (gdata->mtime == s->mtime
136 && strcmp (bfd_get_filename (abfd), s->filename) == 0);
142 gdb_bfd_open (const char *name, const char *target, int fd)
147 struct gdb_bfd_cache_search search;
150 if (gdb_bfd_cache == NULL)
151 gdb_bfd_cache = htab_create_alloc (1, hash_bfd, eq_bfd, NULL,
156 fd = open (name, O_RDONLY | O_BINARY);
159 bfd_set_error (bfd_error_system_call);
164 search.filename = name;
165 if (fstat (fd, &st) < 0)
167 /* Weird situation here. */
171 search.mtime = st.st_mtime;
173 /* Note that this must compute the same result as hash_bfd. */
174 hash = htab_hash_string (name);
175 /* Note that we cannot use htab_find_slot_with_hash here, because
176 opening the BFD may fail; and this would violate hashtab
178 abfd = htab_find_with_hash (gdb_bfd_cache, &search, hash);
186 abfd = bfd_fopen (name, target, FOPEN_RB, fd);
190 slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash, INSERT);
194 gdb_bfd_stash_filename (abfd);
199 /* A helper function that releases any section data attached to the
203 free_one_bfd_section (bfd *abfd, asection *sectp, void *ignore)
205 struct gdb_bfd_section_data *sect = bfd_get_section_userdata (abfd, sectp);
207 if (sect != NULL && sect->data != NULL)
210 if (sect->map_addr != NULL)
214 res = munmap (sect->map_addr, sect->map_len);
215 gdb_assert (res == 0);
223 /* Close ABFD, and warn if that fails. */
226 gdb_bfd_close_or_warn (struct bfd *abfd)
229 char *name = bfd_get_filename (abfd);
231 bfd_map_over_sections (abfd, free_one_bfd_section, NULL);
233 ret = bfd_close (abfd);
236 warning (_("cannot close \"%s\": %s"),
237 name, bfd_errmsg (bfd_get_error ()));
245 gdb_bfd_ref (struct bfd *abfd)
247 struct gdb_bfd_data *gdata;
253 gdata = bfd_usrdata (abfd);
261 /* Ask BFD to decompress sections in bfd_get_full_section_contents. */
262 abfd->flags |= BFD_DECOMPRESS;
264 gdata = bfd_zalloc (abfd, sizeof (struct gdb_bfd_data));
266 gdata->mtime = bfd_get_mtime (abfd);
267 gdata->archive_bfd = NULL;
268 bfd_usrdata (abfd) = gdata;
270 bfd_alloc_data (abfd);
272 /* This is the first we've seen it, so add it to the hash table. */
273 slot = htab_find_slot (all_bfds, abfd, INSERT);
274 gdb_assert (slot && !*slot);
281 gdb_bfd_unref (struct bfd *abfd)
283 struct gdb_bfd_data *gdata;
284 struct gdb_bfd_cache_search search;
290 gdata = bfd_usrdata (abfd);
291 gdb_assert (gdata->refc >= 1);
297 archive_bfd = gdata->archive_bfd;
298 search.filename = bfd_get_filename (abfd);
300 if (gdb_bfd_cache && search.filename)
302 hashval_t hash = htab_hash_string (search.filename);
305 search.mtime = gdata->mtime;
306 slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash,
310 htab_clear_slot (gdb_bfd_cache, slot);
313 bfd_free_data (abfd);
314 bfd_usrdata (abfd) = NULL; /* Paranoia. */
316 htab_remove_elt (all_bfds, abfd);
318 gdb_bfd_close_or_warn (abfd);
320 gdb_bfd_unref (archive_bfd);
323 /* A helper function that returns the section data descriptor
324 associated with SECTION. If no such descriptor exists, a new one
325 is allocated and cleared. */
327 static struct gdb_bfd_section_data *
328 get_section_descriptor (asection *section)
330 struct gdb_bfd_section_data *result;
332 result = bfd_get_section_userdata (section->owner, section);
336 result = bfd_zalloc (section->owner, sizeof (*result));
337 bfd_set_section_userdata (section->owner, section, result);
346 gdb_bfd_map_section (asection *sectp, bfd_size_type *size)
349 unsigned char header[4];
350 struct gdb_bfd_section_data *descriptor;
353 gdb_assert ((sectp->flags & SEC_RELOC) == 0);
354 gdb_assert (size != NULL);
358 descriptor = get_section_descriptor (sectp);
360 /* If the data was already read for this BFD, just reuse it. */
361 if (descriptor->data != NULL)
365 if (!bfd_is_section_compressed (abfd, sectp))
367 /* The page size, used when mmapping. */
371 pagesize = getpagesize ();
373 /* Only try to mmap sections which are large enough: we don't want
374 to waste space due to fragmentation. */
376 if (bfd_get_section_size (sectp) > 4 * pagesize)
378 descriptor->size = bfd_get_section_size (sectp);
379 descriptor->data = bfd_mmap (abfd, 0, descriptor->size, PROT_READ,
380 MAP_PRIVATE, sectp->filepos,
381 &descriptor->map_addr,
382 &descriptor->map_len);
384 if ((caddr_t)descriptor->data != MAP_FAILED)
386 #if HAVE_POSIX_MADVISE
387 posix_madvise (descriptor->map_addr, descriptor->map_len,
388 POSIX_MADV_WILLNEED);
393 /* On failure, clear out the section data and try again. */
394 memset (descriptor, 0, sizeof (*descriptor));
397 #endif /* HAVE_MMAP */
399 /* Handle compressed sections, or ordinary uncompressed sections in
402 descriptor->size = bfd_get_section_size (sectp);
403 descriptor->data = NULL;
406 if (!bfd_get_full_section_contents (abfd, sectp, &data))
407 error (_("Can't read data for section '%s' in file '%s'"),
408 bfd_get_section_name (abfd, sectp),
409 bfd_get_filename (abfd));
410 descriptor->data = data;
413 gdb_assert (descriptor->data != NULL);
414 *size = descriptor->size;
415 return descriptor->data;
423 gdb_bfd_fopen (const char *filename, const char *target, const char *mode,
426 bfd *result = bfd_fopen (filename, target, mode, fd);
430 gdb_bfd_stash_filename (result);
431 gdb_bfd_ref (result);
440 gdb_bfd_openr (const char *filename, const char *target)
442 bfd *result = bfd_openr (filename, target);
446 gdb_bfd_stash_filename (result);
447 gdb_bfd_ref (result);
456 gdb_bfd_openw (const char *filename, const char *target)
458 bfd *result = bfd_openw (filename, target);
462 gdb_bfd_stash_filename (result);
463 gdb_bfd_ref (result);
472 gdb_bfd_openr_iovec (const char *filename, const char *target,
473 void *(*open_func) (struct bfd *nbfd,
476 file_ptr (*pread_func) (struct bfd *nbfd,
481 int (*close_func) (struct bfd *nbfd,
483 int (*stat_func) (struct bfd *abfd,
487 bfd *result = bfd_openr_iovec (filename, target,
488 open_func, open_closure,
489 pread_func, close_func, stat_func);
493 gdb_bfd_ref (result);
494 gdb_bfd_stash_filename (result);
503 gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous)
505 bfd *result = bfd_openr_next_archived_file (archive, previous);
509 struct gdb_bfd_data *gdata;
511 gdb_bfd_ref (result);
512 /* No need to stash the filename here, because we also keep a
513 reference on the parent archive. */
515 gdata = bfd_usrdata (result);
516 gdb_assert (gdata->archive_bfd == NULL || gdata->archive_bfd == archive);
517 gdata->archive_bfd = archive;
518 gdb_bfd_ref (archive);
527 gdb_bfd_fdopenr (const char *filename, const char *target, int fd)
529 bfd *result = bfd_fdopenr (filename, target, fd);
533 gdb_bfd_ref (result);
534 gdb_bfd_stash_filename (result);
542 /* A callback for htab_traverse that prints a single BFD. */
545 print_one_bfd (void **slot, void *data)
548 struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
549 struct ui_out *uiout = data;
550 struct cleanup *inner;
552 inner = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
553 ui_out_field_int (uiout, "refcount", gdata->refc);
554 ui_out_field_string (uiout, "addr", host_address_to_string (abfd));
555 ui_out_field_string (uiout, "filename", bfd_get_filename (abfd));
556 ui_out_text (uiout, "\n");
562 /* Implement the 'maint info bfd' command. */
565 maintenance_info_bfds (char *arg, int from_tty)
567 struct cleanup *cleanup;
568 struct ui_out *uiout = current_uiout;
570 cleanup = make_cleanup_ui_out_table_begin_end (uiout, 3, -1, "bfds");
571 ui_out_table_header (uiout, 10, ui_left, "refcount", "Refcount");
572 ui_out_table_header (uiout, 18, ui_left, "addr", "Address");
573 ui_out_table_header (uiout, 40, ui_left, "filename", "Filename");
575 ui_out_table_body (uiout);
576 htab_traverse (all_bfds, print_one_bfd, uiout);
578 do_cleanups (cleanup);
581 /* -Wmissing-prototypes */
582 extern initialize_file_ftype _initialize_gdb_bfd;
585 _initialize_gdb_bfd (void)
587 all_bfds = htab_create_alloc (10, htab_hash_pointer, htab_eq_pointer,
588 NULL, xcalloc, xfree);
590 add_cmd ("bfds", class_maintenance, maintenance_info_bfds, _("\
591 List the BFDs that are currently open."),
592 &maintenanceinfolist);