1 /* Definitions for BFD wrappers used by GDB.
3 Copyright (C) 2011-2014 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/>. */
22 #include "gdb_assert.h"
27 #include "filestuff.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
;
60 /* An object of this type is stored in each BFD's user data. */
64 /* The reference count. */
67 /* The mtime of the BFD at the point the cache entry was made. */
70 /* This is true if we have determined whether this BFD has any
71 sections requiring relocation. */
72 unsigned int relocation_computed
: 1;
74 /* This is true if any section needs relocation. */
75 unsigned int needs_relocations
: 1;
77 /* This is true if we have successfully computed the file's CRC. */
78 unsigned int crc_computed
: 1;
83 /* If the BFD comes from an archive, this points to the archive's
84 BFD. Otherwise, this is NULL. */
91 #define GDB_BFD_DATA_ACCESSOR(ABFD) \
92 ((struct gdb_bfd_data *) bfd_usrdata (ABFD))
94 DEFINE_REGISTRY (bfd
, GDB_BFD_DATA_ACCESSOR
)
96 /* A hash table storing all the BFDs maintained in the cache. */
98 static htab_t gdb_bfd_cache
;
100 /* The type of an object being looked up in gdb_bfd_cache. We use
101 htab's capability of storing one kind of object (BFD in this case)
102 and using a different sort of object for searching. */
104 struct gdb_bfd_cache_search
107 const char *filename
;
112 /* A hash function for BFDs. */
115 hash_bfd (const void *b
)
119 /* It is simplest to just hash the filename. */
120 return htab_hash_string (bfd_get_filename (abfd
));
123 /* An equality function for BFDs. Note that this expects the caller
124 to search using struct gdb_bfd_cache_search only, not BFDs. */
127 eq_bfd (const void *a
, const void *b
)
130 const struct gdb_bfd_cache_search
*s
= b
;
131 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
133 return (gdata
->mtime
== s
->mtime
134 && strcmp (bfd_get_filename (abfd
), s
->filename
) == 0);
140 gdb_bfd_open (const char *name
, const char *target
, int fd
)
145 struct gdb_bfd_cache_search search
;
148 if (gdb_bfd_cache
== NULL
)
149 gdb_bfd_cache
= htab_create_alloc (1, hash_bfd
, eq_bfd
, NULL
,
154 fd
= gdb_open_cloexec (name
, O_RDONLY
| O_BINARY
, 0);
157 bfd_set_error (bfd_error_system_call
);
162 search
.filename
= name
;
163 if (fstat (fd
, &st
) < 0)
165 /* Weird situation here. */
169 search
.mtime
= st
.st_mtime
;
171 /* Note that this must compute the same result as hash_bfd. */
172 hash
= htab_hash_string (name
);
173 /* Note that we cannot use htab_find_slot_with_hash here, because
174 opening the BFD may fail; and this would violate hashtab
176 abfd
= htab_find_with_hash (gdb_bfd_cache
, &search
, hash
);
184 abfd
= bfd_fopen (name
, target
, FOPEN_RB
, fd
);
188 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
, INSERT
);
196 /* A helper function that releases any section data attached to the
200 free_one_bfd_section (bfd
*abfd
, asection
*sectp
, void *ignore
)
202 struct gdb_bfd_section_data
*sect
= bfd_get_section_userdata (abfd
, sectp
);
204 if (sect
!= NULL
&& sect
->data
!= NULL
)
207 if (sect
->map_addr
!= NULL
)
211 res
= munmap (sect
->map_addr
, sect
->map_len
);
212 gdb_assert (res
== 0);
220 /* Close ABFD, and warn if that fails. */
223 gdb_bfd_close_or_warn (struct bfd
*abfd
)
226 char *name
= bfd_get_filename (abfd
);
228 bfd_map_over_sections (abfd
, free_one_bfd_section
, NULL
);
230 ret
= bfd_close (abfd
);
233 warning (_("cannot close \"%s\": %s"),
234 name
, bfd_errmsg (bfd_get_error ()));
242 gdb_bfd_ref (struct bfd
*abfd
)
244 struct gdb_bfd_data
*gdata
;
250 gdata
= bfd_usrdata (abfd
);
258 /* Ask BFD to decompress sections in bfd_get_full_section_contents. */
259 abfd
->flags
|= BFD_DECOMPRESS
;
261 gdata
= bfd_zalloc (abfd
, sizeof (struct gdb_bfd_data
));
263 gdata
->mtime
= bfd_get_mtime (abfd
);
264 gdata
->archive_bfd
= NULL
;
265 bfd_usrdata (abfd
) = gdata
;
267 bfd_alloc_data (abfd
);
269 /* This is the first we've seen it, so add it to the hash table. */
270 slot
= htab_find_slot (all_bfds
, abfd
, INSERT
);
271 gdb_assert (slot
&& !*slot
);
278 gdb_bfd_unref (struct bfd
*abfd
)
280 struct gdb_bfd_data
*gdata
;
281 struct gdb_bfd_cache_search search
;
287 gdata
= bfd_usrdata (abfd
);
288 gdb_assert (gdata
->refc
>= 1);
294 archive_bfd
= gdata
->archive_bfd
;
295 search
.filename
= bfd_get_filename (abfd
);
297 if (gdb_bfd_cache
&& search
.filename
)
299 hashval_t hash
= htab_hash_string (search
.filename
);
302 search
.mtime
= gdata
->mtime
;
303 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
,
307 htab_clear_slot (gdb_bfd_cache
, slot
);
310 bfd_free_data (abfd
);
311 bfd_usrdata (abfd
) = NULL
; /* Paranoia. */
313 htab_remove_elt (all_bfds
, abfd
);
315 gdb_bfd_close_or_warn (abfd
);
317 gdb_bfd_unref (archive_bfd
);
320 /* A helper function that returns the section data descriptor
321 associated with SECTION. If no such descriptor exists, a new one
322 is allocated and cleared. */
324 static struct gdb_bfd_section_data
*
325 get_section_descriptor (asection
*section
)
327 struct gdb_bfd_section_data
*result
;
329 result
= bfd_get_section_userdata (section
->owner
, section
);
333 result
= bfd_zalloc (section
->owner
, sizeof (*result
));
334 bfd_set_section_userdata (section
->owner
, section
, result
);
343 gdb_bfd_map_section (asection
*sectp
, bfd_size_type
*size
)
346 struct gdb_bfd_section_data
*descriptor
;
349 gdb_assert ((sectp
->flags
& SEC_RELOC
) == 0);
350 gdb_assert (size
!= NULL
);
354 descriptor
= get_section_descriptor (sectp
);
356 /* If the data was already read for this BFD, just reuse it. */
357 if (descriptor
->data
!= NULL
)
361 if (!bfd_is_section_compressed (abfd
, sectp
))
363 /* The page size, used when mmapping. */
367 pagesize
= getpagesize ();
369 /* Only try to mmap sections which are large enough: we don't want
370 to waste space due to fragmentation. */
372 if (bfd_get_section_size (sectp
) > 4 * pagesize
)
374 descriptor
->size
= bfd_get_section_size (sectp
);
375 descriptor
->data
= bfd_mmap (abfd
, 0, descriptor
->size
, PROT_READ
,
376 MAP_PRIVATE
, sectp
->filepos
,
377 &descriptor
->map_addr
,
378 &descriptor
->map_len
);
380 if ((caddr_t
)descriptor
->data
!= MAP_FAILED
)
382 #if HAVE_POSIX_MADVISE
383 posix_madvise (descriptor
->map_addr
, descriptor
->map_len
,
384 POSIX_MADV_WILLNEED
);
389 /* On failure, clear out the section data and try again. */
390 memset (descriptor
, 0, sizeof (*descriptor
));
393 #endif /* HAVE_MMAP */
395 /* Handle compressed sections, or ordinary uncompressed sections in
398 descriptor
->size
= bfd_get_section_size (sectp
);
399 descriptor
->data
= NULL
;
402 if (!bfd_get_full_section_contents (abfd
, sectp
, &data
))
403 error (_("Can't read data for section '%s' in file '%s'"),
404 bfd_get_section_name (abfd
, sectp
),
405 bfd_get_filename (abfd
));
406 descriptor
->data
= data
;
409 gdb_assert (descriptor
->data
!= NULL
);
410 *size
= descriptor
->size
;
411 return descriptor
->data
;
414 /* Return 32-bit CRC for ABFD. If successful store it to *FILE_CRC_RETURN and
415 return 1. Otherwise print a warning and return 0. ABFD seek position is
419 get_file_crc (bfd
*abfd
, unsigned long *file_crc_return
)
421 unsigned long file_crc
= 0;
423 if (bfd_seek (abfd
, 0, SEEK_SET
) != 0)
425 warning (_("Problem reading \"%s\" for CRC: %s"),
426 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
432 gdb_byte buffer
[8 * 1024];
435 count
= bfd_bread (buffer
, sizeof (buffer
), abfd
);
436 if (count
== (bfd_size_type
) -1)
438 warning (_("Problem reading \"%s\" for CRC: %s"),
439 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
444 file_crc
= bfd_calc_gnu_debuglink_crc32 (file_crc
, buffer
, count
);
447 *file_crc_return
= file_crc
;
454 gdb_bfd_crc (struct bfd
*abfd
, unsigned long *crc_out
)
456 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
458 if (!gdata
->crc_computed
)
459 gdata
->crc_computed
= get_file_crc (abfd
, &gdata
->crc
);
461 if (gdata
->crc_computed
)
462 *crc_out
= gdata
->crc
;
463 return gdata
->crc_computed
;
471 gdb_bfd_fopen (const char *filename
, const char *target
, const char *mode
,
474 bfd
*result
= bfd_fopen (filename
, target
, mode
, fd
);
477 gdb_bfd_ref (result
);
485 gdb_bfd_openr (const char *filename
, const char *target
)
487 bfd
*result
= bfd_openr (filename
, target
);
490 gdb_bfd_ref (result
);
498 gdb_bfd_openw (const char *filename
, const char *target
)
500 bfd
*result
= bfd_openw (filename
, target
);
503 gdb_bfd_ref (result
);
511 gdb_bfd_openr_iovec (const char *filename
, const char *target
,
512 void *(*open_func
) (struct bfd
*nbfd
,
515 file_ptr (*pread_func
) (struct bfd
*nbfd
,
520 int (*close_func
) (struct bfd
*nbfd
,
522 int (*stat_func
) (struct bfd
*abfd
,
526 bfd
*result
= bfd_openr_iovec (filename
, target
,
527 open_func
, open_closure
,
528 pread_func
, close_func
, stat_func
);
531 gdb_bfd_ref (result
);
539 gdb_bfd_mark_parent (bfd
*child
, bfd
*parent
)
541 struct gdb_bfd_data
*gdata
;
544 /* No need to stash the filename here, because we also keep a
545 reference on the parent archive. */
547 gdata
= bfd_usrdata (child
);
548 if (gdata
->archive_bfd
== NULL
)
550 gdata
->archive_bfd
= parent
;
551 gdb_bfd_ref (parent
);
554 gdb_assert (gdata
->archive_bfd
== parent
);
560 gdb_bfd_openr_next_archived_file (bfd
*archive
, bfd
*previous
)
562 bfd
*result
= bfd_openr_next_archived_file (archive
, previous
);
565 gdb_bfd_mark_parent (result
, archive
);
573 gdb_bfd_fdopenr (const char *filename
, const char *target
, int fd
)
575 bfd
*result
= bfd_fdopenr (filename
, target
, fd
);
578 gdb_bfd_ref (result
);
585 gdb_static_assert (ARRAY_SIZE (_bfd_std_section
) == 4);
590 gdb_bfd_section_index (bfd
*abfd
, asection
*section
)
594 else if (section
== bfd_com_section_ptr
)
595 return bfd_count_sections (abfd
) + 1;
596 else if (section
== bfd_und_section_ptr
)
597 return bfd_count_sections (abfd
) + 2;
598 else if (section
== bfd_abs_section_ptr
)
599 return bfd_count_sections (abfd
) + 3;
600 else if (section
== bfd_ind_section_ptr
)
601 return bfd_count_sections (abfd
) + 4;
602 return section
->index
;
608 gdb_bfd_count_sections (bfd
*abfd
)
610 return bfd_count_sections (abfd
) + 4;
616 gdb_bfd_requires_relocations (bfd
*abfd
)
618 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
620 if (gdata
->relocation_computed
== 0)
624 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
625 if ((sect
->flags
& SEC_RELOC
) != 0)
627 gdata
->needs_relocations
= 1;
631 gdata
->relocation_computed
= 1;
634 return gdata
->needs_relocations
;
639 /* A callback for htab_traverse that prints a single BFD. */
642 print_one_bfd (void **slot
, void *data
)
645 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
646 struct ui_out
*uiout
= data
;
647 struct cleanup
*inner
;
649 inner
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
650 ui_out_field_int (uiout
, "refcount", gdata
->refc
);
651 ui_out_field_string (uiout
, "addr", host_address_to_string (abfd
));
652 ui_out_field_string (uiout
, "filename", bfd_get_filename (abfd
));
653 ui_out_text (uiout
, "\n");
659 /* Implement the 'maint info bfd' command. */
662 maintenance_info_bfds (char *arg
, int from_tty
)
664 struct cleanup
*cleanup
;
665 struct ui_out
*uiout
= current_uiout
;
667 cleanup
= make_cleanup_ui_out_table_begin_end (uiout
, 3, -1, "bfds");
668 ui_out_table_header (uiout
, 10, ui_left
, "refcount", "Refcount");
669 ui_out_table_header (uiout
, 18, ui_left
, "addr", "Address");
670 ui_out_table_header (uiout
, 40, ui_left
, "filename", "Filename");
672 ui_out_table_body (uiout
);
673 htab_traverse (all_bfds
, print_one_bfd
, uiout
);
675 do_cleanups (cleanup
);
678 /* -Wmissing-prototypes */
679 extern initialize_file_ftype _initialize_gdb_bfd
;
682 _initialize_gdb_bfd (void)
684 all_bfds
= htab_create_alloc (10, htab_hash_pointer
, htab_eq_pointer
,
685 NULL
, xcalloc
, xfree
);
687 add_cmd ("bfds", class_maintenance
, maintenance_info_bfds
, _("\
688 List the BFDs that are currently open."),
689 &maintenanceinfolist
);