1 /* Definitions for BFD wrappers used by GDB.
3 Copyright (C) 2011-2015 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/>. */
25 #include "filestuff.h"
33 #define MAP_FAILED ((void *) -1)
40 /* An object of this type is stored in the section's user data when
43 struct gdb_bfd_section_data
45 /* Size of the data. */
47 /* If the data was mmapped, this is the length of the map. */
48 bfd_size_type map_len
;
49 /* The data. If NULL, the section data has not been read. */
51 /* If the data was mmapped, this is the map address. */
55 /* A hash table holding every BFD that gdb knows about. This is not
56 to be confused with 'gdb_bfd_cache', which is used for sharing
57 BFDs; in contrast, this hash is used just to implement
60 static htab_t all_bfds
;
62 /* An object of this type is stored in each BFD's user data. */
66 /* The reference count. */
69 /* The mtime of the BFD at the point the cache entry was made. */
72 /* This is true if we have determined whether this BFD has any
73 sections requiring relocation. */
74 unsigned int relocation_computed
: 1;
76 /* This is true if any section needs relocation. */
77 unsigned int needs_relocations
: 1;
79 /* This is true if we have successfully computed the file's CRC. */
80 unsigned int crc_computed
: 1;
85 /* If the BFD comes from an archive, this points to the archive's
86 BFD. Otherwise, this is NULL. */
89 /* Table of all the bfds this bfd has included. */
90 VEC (bfdp
) *included_bfds
;
96 #define GDB_BFD_DATA_ACCESSOR(ABFD) \
97 ((struct gdb_bfd_data *) bfd_usrdata (ABFD))
99 DEFINE_REGISTRY (bfd
, GDB_BFD_DATA_ACCESSOR
)
101 /* A hash table storing all the BFDs maintained in the cache. */
103 static htab_t gdb_bfd_cache
;
105 /* The type of an object being looked up in gdb_bfd_cache. We use
106 htab's capability of storing one kind of object (BFD in this case)
107 and using a different sort of object for searching. */
109 struct gdb_bfd_cache_search
112 const char *filename
;
117 /* A hash function for BFDs. */
120 hash_bfd (const void *b
)
124 /* It is simplest to just hash the filename. */
125 return htab_hash_string (bfd_get_filename (abfd
));
128 /* An equality function for BFDs. Note that this expects the caller
129 to search using struct gdb_bfd_cache_search only, not BFDs. */
132 eq_bfd (const void *a
, const void *b
)
135 const struct gdb_bfd_cache_search
*s
= b
;
136 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
138 return (gdata
->mtime
== s
->mtime
139 && strcmp (bfd_get_filename (abfd
), s
->filename
) == 0);
145 gdb_bfd_open (const char *name
, const char *target
, int fd
)
150 struct gdb_bfd_cache_search search
;
153 if (gdb_bfd_cache
== NULL
)
154 gdb_bfd_cache
= htab_create_alloc (1, hash_bfd
, eq_bfd
, NULL
,
159 fd
= gdb_open_cloexec (name
, O_RDONLY
| O_BINARY
, 0);
162 bfd_set_error (bfd_error_system_call
);
167 search
.filename
= name
;
168 if (fstat (fd
, &st
) < 0)
170 /* Weird situation here. */
174 search
.mtime
= st
.st_mtime
;
176 /* Note that this must compute the same result as hash_bfd. */
177 hash
= htab_hash_string (name
);
178 /* Note that we cannot use htab_find_slot_with_hash here, because
179 opening the BFD may fail; and this would violate hashtab
181 abfd
= htab_find_with_hash (gdb_bfd_cache
, &search
, hash
);
189 abfd
= bfd_fopen (name
, target
, FOPEN_RB
, fd
);
193 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
, INSERT
);
201 /* A helper function that releases any section data attached to the
205 free_one_bfd_section (bfd
*abfd
, asection
*sectp
, void *ignore
)
207 struct gdb_bfd_section_data
*sect
= bfd_get_section_userdata (abfd
, sectp
);
209 if (sect
!= NULL
&& sect
->data
!= NULL
)
212 if (sect
->map_addr
!= NULL
)
216 res
= munmap (sect
->map_addr
, sect
->map_len
);
217 gdb_assert (res
== 0);
225 /* Close ABFD, and warn if that fails. */
228 gdb_bfd_close_or_warn (struct bfd
*abfd
)
231 char *name
= bfd_get_filename (abfd
);
233 bfd_map_over_sections (abfd
, free_one_bfd_section
, NULL
);
235 ret
= bfd_close (abfd
);
238 warning (_("cannot close \"%s\": %s"),
239 name
, bfd_errmsg (bfd_get_error ()));
247 gdb_bfd_ref (struct bfd
*abfd
)
249 struct gdb_bfd_data
*gdata
;
255 gdata
= bfd_usrdata (abfd
);
263 /* Ask BFD to decompress sections in bfd_get_full_section_contents. */
264 abfd
->flags
|= BFD_DECOMPRESS
;
266 gdata
= bfd_zalloc (abfd
, sizeof (struct gdb_bfd_data
));
268 gdata
->mtime
= bfd_get_mtime (abfd
);
269 gdata
->archive_bfd
= NULL
;
270 bfd_usrdata (abfd
) = gdata
;
272 bfd_alloc_data (abfd
);
274 /* This is the first we've seen it, so add it to the hash table. */
275 slot
= htab_find_slot (all_bfds
, abfd
, INSERT
);
276 gdb_assert (slot
&& !*slot
);
283 gdb_bfd_unref (struct bfd
*abfd
)
286 struct gdb_bfd_data
*gdata
;
287 struct gdb_bfd_cache_search search
;
288 bfd
*archive_bfd
, *included_bfd
;
293 gdata
= bfd_usrdata (abfd
);
294 gdb_assert (gdata
->refc
>= 1);
300 archive_bfd
= gdata
->archive_bfd
;
301 search
.filename
= bfd_get_filename (abfd
);
303 if (gdb_bfd_cache
&& search
.filename
)
305 hashval_t hash
= htab_hash_string (search
.filename
);
308 search
.mtime
= gdata
->mtime
;
309 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
,
313 htab_clear_slot (gdb_bfd_cache
, slot
);
317 VEC_iterate (bfdp
, gdata
->included_bfds
, ix
, included_bfd
);
319 gdb_bfd_unref (included_bfd
);
320 VEC_free (bfdp
, gdata
->included_bfds
);
322 bfd_free_data (abfd
);
323 bfd_usrdata (abfd
) = NULL
; /* Paranoia. */
325 htab_remove_elt (all_bfds
, abfd
);
327 gdb_bfd_close_or_warn (abfd
);
329 gdb_bfd_unref (archive_bfd
);
332 /* A helper function that returns the section data descriptor
333 associated with SECTION. If no such descriptor exists, a new one
334 is allocated and cleared. */
336 static struct gdb_bfd_section_data
*
337 get_section_descriptor (asection
*section
)
339 struct gdb_bfd_section_data
*result
;
341 result
= bfd_get_section_userdata (section
->owner
, section
);
345 result
= bfd_zalloc (section
->owner
, sizeof (*result
));
346 bfd_set_section_userdata (section
->owner
, section
, result
);
355 gdb_bfd_map_section (asection
*sectp
, bfd_size_type
*size
)
358 struct gdb_bfd_section_data
*descriptor
;
361 gdb_assert ((sectp
->flags
& SEC_RELOC
) == 0);
362 gdb_assert (size
!= NULL
);
366 descriptor
= get_section_descriptor (sectp
);
368 /* If the data was already read for this BFD, just reuse it. */
369 if (descriptor
->data
!= NULL
)
373 if (!bfd_is_section_compressed (abfd
, sectp
))
375 /* The page size, used when mmapping. */
379 pagesize
= getpagesize ();
381 /* Only try to mmap sections which are large enough: we don't want
382 to waste space due to fragmentation. */
384 if (bfd_get_section_size (sectp
) > 4 * pagesize
)
386 descriptor
->size
= bfd_get_section_size (sectp
);
387 descriptor
->data
= bfd_mmap (abfd
, 0, descriptor
->size
, PROT_READ
,
388 MAP_PRIVATE
, sectp
->filepos
,
389 &descriptor
->map_addr
,
390 &descriptor
->map_len
);
392 if ((caddr_t
)descriptor
->data
!= MAP_FAILED
)
394 #if HAVE_POSIX_MADVISE
395 posix_madvise (descriptor
->map_addr
, descriptor
->map_len
,
396 POSIX_MADV_WILLNEED
);
401 /* On failure, clear out the section data and try again. */
402 memset (descriptor
, 0, sizeof (*descriptor
));
405 #endif /* HAVE_MMAP */
407 /* Handle compressed sections, or ordinary uncompressed sections in
410 descriptor
->size
= bfd_get_section_size (sectp
);
411 descriptor
->data
= NULL
;
414 if (!bfd_get_full_section_contents (abfd
, sectp
, &data
))
415 error (_("Can't read data for section '%s' in file '%s'"),
416 bfd_get_section_name (abfd
, sectp
),
417 bfd_get_filename (abfd
));
418 descriptor
->data
= data
;
421 gdb_assert (descriptor
->data
!= NULL
);
422 *size
= descriptor
->size
;
423 return descriptor
->data
;
426 /* Return 32-bit CRC for ABFD. If successful store it to *FILE_CRC_RETURN and
427 return 1. Otherwise print a warning and return 0. ABFD seek position is
431 get_file_crc (bfd
*abfd
, unsigned long *file_crc_return
)
433 unsigned long file_crc
= 0;
435 if (bfd_seek (abfd
, 0, SEEK_SET
) != 0)
437 warning (_("Problem reading \"%s\" for CRC: %s"),
438 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
444 gdb_byte buffer
[8 * 1024];
447 count
= bfd_bread (buffer
, sizeof (buffer
), abfd
);
448 if (count
== (bfd_size_type
) -1)
450 warning (_("Problem reading \"%s\" for CRC: %s"),
451 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
456 file_crc
= bfd_calc_gnu_debuglink_crc32 (file_crc
, buffer
, count
);
459 *file_crc_return
= file_crc
;
466 gdb_bfd_crc (struct bfd
*abfd
, unsigned long *crc_out
)
468 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
470 if (!gdata
->crc_computed
)
471 gdata
->crc_computed
= get_file_crc (abfd
, &gdata
->crc
);
473 if (gdata
->crc_computed
)
474 *crc_out
= gdata
->crc
;
475 return gdata
->crc_computed
;
483 gdb_bfd_fopen (const char *filename
, const char *target
, const char *mode
,
486 bfd
*result
= bfd_fopen (filename
, target
, mode
, fd
);
489 gdb_bfd_ref (result
);
497 gdb_bfd_openr (const char *filename
, const char *target
)
499 bfd
*result
= bfd_openr (filename
, target
);
502 gdb_bfd_ref (result
);
510 gdb_bfd_openw (const char *filename
, const char *target
)
512 bfd
*result
= bfd_openw (filename
, target
);
515 gdb_bfd_ref (result
);
523 gdb_bfd_openr_iovec (const char *filename
, const char *target
,
524 void *(*open_func
) (struct bfd
*nbfd
,
527 file_ptr (*pread_func
) (struct bfd
*nbfd
,
532 int (*close_func
) (struct bfd
*nbfd
,
534 int (*stat_func
) (struct bfd
*abfd
,
538 bfd
*result
= bfd_openr_iovec (filename
, target
,
539 open_func
, open_closure
,
540 pread_func
, close_func
, stat_func
);
543 gdb_bfd_ref (result
);
551 gdb_bfd_mark_parent (bfd
*child
, bfd
*parent
)
553 struct gdb_bfd_data
*gdata
;
556 /* No need to stash the filename here, because we also keep a
557 reference on the parent archive. */
559 gdata
= bfd_usrdata (child
);
560 if (gdata
->archive_bfd
== NULL
)
562 gdata
->archive_bfd
= parent
;
563 gdb_bfd_ref (parent
);
566 gdb_assert (gdata
->archive_bfd
== parent
);
572 gdb_bfd_openr_next_archived_file (bfd
*archive
, bfd
*previous
)
574 bfd
*result
= bfd_openr_next_archived_file (archive
, previous
);
577 gdb_bfd_mark_parent (result
, archive
);
585 gdb_bfd_record_inclusion (bfd
*includer
, bfd
*includee
)
587 struct gdb_bfd_data
*gdata
;
589 gdb_bfd_ref (includee
);
590 gdata
= bfd_usrdata (includer
);
591 VEC_safe_push (bfdp
, gdata
->included_bfds
, includee
);
597 gdb_bfd_fdopenr (const char *filename
, const char *target
, int fd
)
599 bfd
*result
= bfd_fdopenr (filename
, target
, fd
);
602 gdb_bfd_ref (result
);
609 gdb_static_assert (ARRAY_SIZE (_bfd_std_section
) == 4);
614 gdb_bfd_section_index (bfd
*abfd
, asection
*section
)
618 else if (section
== bfd_com_section_ptr
)
619 return bfd_count_sections (abfd
) + 1;
620 else if (section
== bfd_und_section_ptr
)
621 return bfd_count_sections (abfd
) + 2;
622 else if (section
== bfd_abs_section_ptr
)
623 return bfd_count_sections (abfd
) + 3;
624 else if (section
== bfd_ind_section_ptr
)
625 return bfd_count_sections (abfd
) + 4;
626 return section
->index
;
632 gdb_bfd_count_sections (bfd
*abfd
)
634 return bfd_count_sections (abfd
) + 4;
640 gdb_bfd_requires_relocations (bfd
*abfd
)
642 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
644 if (gdata
->relocation_computed
== 0)
648 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
649 if ((sect
->flags
& SEC_RELOC
) != 0)
651 gdata
->needs_relocations
= 1;
655 gdata
->relocation_computed
= 1;
658 return gdata
->needs_relocations
;
663 /* A callback for htab_traverse that prints a single BFD. */
666 print_one_bfd (void **slot
, void *data
)
669 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
670 struct ui_out
*uiout
= data
;
671 struct cleanup
*inner
;
673 inner
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
674 ui_out_field_int (uiout
, "refcount", gdata
->refc
);
675 ui_out_field_string (uiout
, "addr", host_address_to_string (abfd
));
676 ui_out_field_string (uiout
, "filename", bfd_get_filename (abfd
));
677 ui_out_text (uiout
, "\n");
683 /* Implement the 'maint info bfd' command. */
686 maintenance_info_bfds (char *arg
, int from_tty
)
688 struct cleanup
*cleanup
;
689 struct ui_out
*uiout
= current_uiout
;
691 cleanup
= make_cleanup_ui_out_table_begin_end (uiout
, 3, -1, "bfds");
692 ui_out_table_header (uiout
, 10, ui_left
, "refcount", "Refcount");
693 ui_out_table_header (uiout
, 18, ui_left
, "addr", "Address");
694 ui_out_table_header (uiout
, 40, ui_left
, "filename", "Filename");
696 ui_out_table_body (uiout
);
697 htab_traverse (all_bfds
, print_one_bfd
, uiout
);
699 do_cleanups (cleanup
);
702 /* -Wmissing-prototypes */
703 extern initialize_file_ftype _initialize_gdb_bfd
;
706 _initialize_gdb_bfd (void)
708 all_bfds
= htab_create_alloc (10, htab_hash_pointer
, htab_eq_pointer
,
709 NULL
, xcalloc
, xfree
);
711 add_cmd ("bfds", class_maintenance
, maintenance_info_bfds
, _("\
712 List the BFDs that are currently open."),
713 &maintenanceinfolist
);