1 /* Definitions for BFD wrappers used by GDB.
3 Copyright (C) 2011-2013 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"
23 #include "gdb_string.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
;
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 /* This is true if we have determined whether this BFD has any
86 sections requiring relocation. */
87 unsigned int relocation_computed
: 1;
89 /* This is true if any section needs relocation. */
90 unsigned int needs_relocations
: 1;
92 /* This is true if we have successfully computed the file's CRC. */
93 unsigned int crc_computed
: 1;
98 /* If the BFD comes from an archive, this points to the archive's
99 BFD. Otherwise, this is NULL. */
106 #define GDB_BFD_DATA_ACCESSOR(ABFD) \
107 ((struct gdb_bfd_data *) bfd_usrdata (ABFD))
109 DEFINE_REGISTRY (bfd
, GDB_BFD_DATA_ACCESSOR
)
111 /* A hash table storing all the BFDs maintained in the cache. */
113 static htab_t gdb_bfd_cache
;
115 /* The type of an object being looked up in gdb_bfd_cache. We use
116 htab's capability of storing one kind of object (BFD in this case)
117 and using a different sort of object for searching. */
119 struct gdb_bfd_cache_search
122 const char *filename
;
127 /* A hash function for BFDs. */
130 hash_bfd (const void *b
)
134 /* It is simplest to just hash the filename. */
135 return htab_hash_string (bfd_get_filename (abfd
));
138 /* An equality function for BFDs. Note that this expects the caller
139 to search using struct gdb_bfd_cache_search only, not BFDs. */
142 eq_bfd (const void *a
, const void *b
)
145 const struct gdb_bfd_cache_search
*s
= b
;
146 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
148 return (gdata
->mtime
== s
->mtime
149 && strcmp (bfd_get_filename (abfd
), s
->filename
) == 0);
155 gdb_bfd_open (const char *name
, const char *target
, int fd
)
160 struct gdb_bfd_cache_search search
;
163 if (gdb_bfd_cache
== NULL
)
164 gdb_bfd_cache
= htab_create_alloc (1, hash_bfd
, eq_bfd
, NULL
,
169 fd
= gdb_open_cloexec (name
, O_RDONLY
| O_BINARY
, 0);
172 bfd_set_error (bfd_error_system_call
);
177 search
.filename
= name
;
178 if (fstat (fd
, &st
) < 0)
180 /* Weird situation here. */
184 search
.mtime
= st
.st_mtime
;
186 /* Note that this must compute the same result as hash_bfd. */
187 hash
= htab_hash_string (name
);
188 /* Note that we cannot use htab_find_slot_with_hash here, because
189 opening the BFD may fail; and this would violate hashtab
191 abfd
= htab_find_with_hash (gdb_bfd_cache
, &search
, hash
);
199 abfd
= bfd_fopen (name
, target
, FOPEN_RB
, fd
);
203 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
, INSERT
);
207 gdb_bfd_stash_filename (abfd
);
212 /* A helper function that releases any section data attached to the
216 free_one_bfd_section (bfd
*abfd
, asection
*sectp
, void *ignore
)
218 struct gdb_bfd_section_data
*sect
= bfd_get_section_userdata (abfd
, sectp
);
220 if (sect
!= NULL
&& sect
->data
!= NULL
)
223 if (sect
->map_addr
!= NULL
)
227 res
= munmap (sect
->map_addr
, sect
->map_len
);
228 gdb_assert (res
== 0);
236 /* Close ABFD, and warn if that fails. */
239 gdb_bfd_close_or_warn (struct bfd
*abfd
)
242 char *name
= bfd_get_filename (abfd
);
244 bfd_map_over_sections (abfd
, free_one_bfd_section
, NULL
);
246 ret
= bfd_close (abfd
);
249 warning (_("cannot close \"%s\": %s"),
250 name
, bfd_errmsg (bfd_get_error ()));
258 gdb_bfd_ref (struct bfd
*abfd
)
260 struct gdb_bfd_data
*gdata
;
266 gdata
= bfd_usrdata (abfd
);
274 /* Ask BFD to decompress sections in bfd_get_full_section_contents. */
275 abfd
->flags
|= BFD_DECOMPRESS
;
277 gdata
= bfd_zalloc (abfd
, sizeof (struct gdb_bfd_data
));
279 gdata
->mtime
= bfd_get_mtime (abfd
);
280 gdata
->archive_bfd
= NULL
;
281 bfd_usrdata (abfd
) = gdata
;
283 bfd_alloc_data (abfd
);
285 /* This is the first we've seen it, so add it to the hash table. */
286 slot
= htab_find_slot (all_bfds
, abfd
, INSERT
);
287 gdb_assert (slot
&& !*slot
);
294 gdb_bfd_unref (struct bfd
*abfd
)
296 struct gdb_bfd_data
*gdata
;
297 struct gdb_bfd_cache_search search
;
303 gdata
= bfd_usrdata (abfd
);
304 gdb_assert (gdata
->refc
>= 1);
310 archive_bfd
= gdata
->archive_bfd
;
311 search
.filename
= bfd_get_filename (abfd
);
313 if (gdb_bfd_cache
&& search
.filename
)
315 hashval_t hash
= htab_hash_string (search
.filename
);
318 search
.mtime
= gdata
->mtime
;
319 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
,
323 htab_clear_slot (gdb_bfd_cache
, slot
);
326 bfd_free_data (abfd
);
327 bfd_usrdata (abfd
) = NULL
; /* Paranoia. */
329 htab_remove_elt (all_bfds
, abfd
);
331 gdb_bfd_close_or_warn (abfd
);
333 gdb_bfd_unref (archive_bfd
);
336 /* A helper function that returns the section data descriptor
337 associated with SECTION. If no such descriptor exists, a new one
338 is allocated and cleared. */
340 static struct gdb_bfd_section_data
*
341 get_section_descriptor (asection
*section
)
343 struct gdb_bfd_section_data
*result
;
345 result
= bfd_get_section_userdata (section
->owner
, section
);
349 result
= bfd_zalloc (section
->owner
, sizeof (*result
));
350 bfd_set_section_userdata (section
->owner
, section
, result
);
359 gdb_bfd_map_section (asection
*sectp
, bfd_size_type
*size
)
362 struct gdb_bfd_section_data
*descriptor
;
365 gdb_assert ((sectp
->flags
& SEC_RELOC
) == 0);
366 gdb_assert (size
!= NULL
);
370 descriptor
= get_section_descriptor (sectp
);
372 /* If the data was already read for this BFD, just reuse it. */
373 if (descriptor
->data
!= NULL
)
377 if (!bfd_is_section_compressed (abfd
, sectp
))
379 /* The page size, used when mmapping. */
383 pagesize
= getpagesize ();
385 /* Only try to mmap sections which are large enough: we don't want
386 to waste space due to fragmentation. */
388 if (bfd_get_section_size (sectp
) > 4 * pagesize
)
390 descriptor
->size
= bfd_get_section_size (sectp
);
391 descriptor
->data
= bfd_mmap (abfd
, 0, descriptor
->size
, PROT_READ
,
392 MAP_PRIVATE
, sectp
->filepos
,
393 &descriptor
->map_addr
,
394 &descriptor
->map_len
);
396 if ((caddr_t
)descriptor
->data
!= MAP_FAILED
)
398 #if HAVE_POSIX_MADVISE
399 posix_madvise (descriptor
->map_addr
, descriptor
->map_len
,
400 POSIX_MADV_WILLNEED
);
405 /* On failure, clear out the section data and try again. */
406 memset (descriptor
, 0, sizeof (*descriptor
));
409 #endif /* HAVE_MMAP */
411 /* Handle compressed sections, or ordinary uncompressed sections in
414 descriptor
->size
= bfd_get_section_size (sectp
);
415 descriptor
->data
= NULL
;
418 if (!bfd_get_full_section_contents (abfd
, sectp
, &data
))
419 error (_("Can't read data for section '%s' in file '%s'"),
420 bfd_get_section_name (abfd
, sectp
),
421 bfd_get_filename (abfd
));
422 descriptor
->data
= data
;
425 gdb_assert (descriptor
->data
!= NULL
);
426 *size
= descriptor
->size
;
427 return descriptor
->data
;
430 /* Return 32-bit CRC for ABFD. If successful store it to *FILE_CRC_RETURN and
431 return 1. Otherwise print a warning and return 0. ABFD seek position is
435 get_file_crc (bfd
*abfd
, unsigned long *file_crc_return
)
437 unsigned long file_crc
= 0;
439 if (bfd_seek (abfd
, 0, SEEK_SET
) != 0)
441 warning (_("Problem reading \"%s\" for CRC: %s"),
442 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
448 gdb_byte buffer
[8 * 1024];
451 count
= bfd_bread (buffer
, sizeof (buffer
), abfd
);
452 if (count
== (bfd_size_type
) -1)
454 warning (_("Problem reading \"%s\" for CRC: %s"),
455 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
460 file_crc
= bfd_calc_gnu_debuglink_crc32 (file_crc
, buffer
, count
);
463 *file_crc_return
= file_crc
;
470 gdb_bfd_crc (struct bfd
*abfd
, unsigned long *crc_out
)
472 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
474 if (!gdata
->crc_computed
)
475 gdata
->crc_computed
= get_file_crc (abfd
, &gdata
->crc
);
477 if (gdata
->crc_computed
)
478 *crc_out
= gdata
->crc
;
479 return gdata
->crc_computed
;
487 gdb_bfd_fopen (const char *filename
, const char *target
, const char *mode
,
490 bfd
*result
= bfd_fopen (filename
, target
, mode
, fd
);
494 gdb_bfd_stash_filename (result
);
495 gdb_bfd_ref (result
);
504 gdb_bfd_openr (const char *filename
, const char *target
)
506 bfd
*result
= bfd_openr (filename
, target
);
510 gdb_bfd_stash_filename (result
);
511 gdb_bfd_ref (result
);
520 gdb_bfd_openw (const char *filename
, const char *target
)
522 bfd
*result
= bfd_openw (filename
, target
);
526 gdb_bfd_stash_filename (result
);
527 gdb_bfd_ref (result
);
536 gdb_bfd_openr_iovec (const char *filename
, const char *target
,
537 void *(*open_func
) (struct bfd
*nbfd
,
540 file_ptr (*pread_func
) (struct bfd
*nbfd
,
545 int (*close_func
) (struct bfd
*nbfd
,
547 int (*stat_func
) (struct bfd
*abfd
,
551 bfd
*result
= bfd_openr_iovec (filename
, target
,
552 open_func
, open_closure
,
553 pread_func
, close_func
, stat_func
);
557 gdb_bfd_ref (result
);
558 gdb_bfd_stash_filename (result
);
567 gdb_bfd_mark_parent (bfd
*child
, bfd
*parent
)
569 struct gdb_bfd_data
*gdata
;
572 /* No need to stash the filename here, because we also keep a
573 reference on the parent archive. */
575 gdata
= bfd_usrdata (child
);
576 if (gdata
->archive_bfd
== NULL
)
578 gdata
->archive_bfd
= parent
;
579 gdb_bfd_ref (parent
);
582 gdb_assert (gdata
->archive_bfd
== parent
);
588 gdb_bfd_openr_next_archived_file (bfd
*archive
, bfd
*previous
)
590 bfd
*result
= bfd_openr_next_archived_file (archive
, previous
);
593 gdb_bfd_mark_parent (result
, archive
);
601 gdb_bfd_fdopenr (const char *filename
, const char *target
, int fd
)
603 bfd
*result
= bfd_fdopenr (filename
, target
, fd
);
607 gdb_bfd_ref (result
);
608 gdb_bfd_stash_filename (result
);
616 gdb_static_assert (ARRAY_SIZE (_bfd_std_section
) == 4);
621 gdb_bfd_section_index (bfd
*abfd
, asection
*section
)
625 else if (section
== bfd_com_section_ptr
)
626 return bfd_count_sections (abfd
) + 1;
627 else if (section
== bfd_und_section_ptr
)
628 return bfd_count_sections (abfd
) + 2;
629 else if (section
== bfd_abs_section_ptr
)
630 return bfd_count_sections (abfd
) + 3;
631 else if (section
== bfd_ind_section_ptr
)
632 return bfd_count_sections (abfd
) + 4;
633 return section
->index
;
639 gdb_bfd_count_sections (bfd
*abfd
)
641 return bfd_count_sections (abfd
) + 4;
647 gdb_bfd_requires_relocations (bfd
*abfd
)
649 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
651 if (gdata
->relocation_computed
== 0)
655 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
656 if ((sect
->flags
& SEC_RELOC
) != 0)
658 gdata
->needs_relocations
= 1;
662 gdata
->relocation_computed
= 1;
665 return gdata
->needs_relocations
;
670 /* A callback for htab_traverse that prints a single BFD. */
673 print_one_bfd (void **slot
, void *data
)
676 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
677 struct ui_out
*uiout
= data
;
678 struct cleanup
*inner
;
680 inner
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
681 ui_out_field_int (uiout
, "refcount", gdata
->refc
);
682 ui_out_field_string (uiout
, "addr", host_address_to_string (abfd
));
683 ui_out_field_string (uiout
, "filename", bfd_get_filename (abfd
));
684 ui_out_text (uiout
, "\n");
690 /* Implement the 'maint info bfd' command. */
693 maintenance_info_bfds (char *arg
, int from_tty
)
695 struct cleanup
*cleanup
;
696 struct ui_out
*uiout
= current_uiout
;
698 cleanup
= make_cleanup_ui_out_table_begin_end (uiout
, 3, -1, "bfds");
699 ui_out_table_header (uiout
, 10, ui_left
, "refcount", "Refcount");
700 ui_out_table_header (uiout
, 18, ui_left
, "addr", "Address");
701 ui_out_table_header (uiout
, 40, ui_left
, "filename", "Filename");
703 ui_out_table_body (uiout
);
704 htab_traverse (all_bfds
, print_one_bfd
, uiout
);
706 do_cleanups (cleanup
);
709 /* -Wmissing-prototypes */
710 extern initialize_file_ftype _initialize_gdb_bfd
;
713 _initialize_gdb_bfd (void)
715 all_bfds
= htab_create_alloc (10, htab_hash_pointer
, htab_eq_pointer
,
716 NULL
, xcalloc
, xfree
);
718 add_cmd ("bfds", class_maintenance
, maintenance_info_bfds
, _("\
719 List the BFDs that are currently open."),
720 &maintenanceinfolist
);