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"
30 #define MAP_FAILED ((void *) -1)
34 #include "gdb/fileio.h"
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 is_target_filename (const char *name)
147 return startswith (name, TARGET_SYSROOT_PREFIX);
153 gdb_bfd_has_target_filename (struct bfd *abfd)
155 return is_target_filename (bfd_get_filename (abfd));
159 /* Return the system error number corresponding to ERRNUM. */
162 fileio_errno_to_host (int errnum)
206 case FILEIO_ENAMETOOLONG:
212 /* Wrapper for target_fileio_open suitable for passing as the
213 OPEN_FUNC argument to gdb_bfd_openr_iovec. The supplied
214 OPEN_CLOSURE is unused. */
217 gdb_bfd_iovec_fileio_open (struct bfd *abfd, void *inferior)
219 const char *filename = bfd_get_filename (abfd);
220 int fd, target_errno;
223 gdb_assert (is_target_filename (filename));
225 fd = target_fileio_open ((struct inferior *) inferior,
226 filename + strlen (TARGET_SYSROOT_PREFIX),
231 errno = fileio_errno_to_host (target_errno);
232 bfd_set_error (bfd_error_system_call);
236 stream = XCNEW (int);
241 /* Wrapper for target_fileio_pread suitable for passing as the
242 PREAD_FUNC argument to gdb_bfd_openr_iovec. */
245 gdb_bfd_iovec_fileio_pread (struct bfd *abfd, void *stream, void *buf,
246 file_ptr nbytes, file_ptr offset)
248 int fd = *(int *) stream;
255 bytes = target_fileio_pread (fd, (gdb_byte *) buf + pos,
256 nbytes - pos, offset + pos,
259 /* Success, but no bytes, means end-of-file. */
263 errno = fileio_errno_to_host (target_errno);
264 bfd_set_error (bfd_error_system_call);
274 /* Wrapper for target_fileio_close suitable for passing as the
275 CLOSE_FUNC argument to gdb_bfd_openr_iovec. */
278 gdb_bfd_iovec_fileio_close (struct bfd *abfd, void *stream)
280 int fd = *(int *) stream;
285 /* Ignore errors on close. These may happen with remote
286 targets if the connection has already been torn down. */
287 target_fileio_close (fd, &target_errno);
289 /* Zero means success. */
293 /* Wrapper for target_fileio_fstat suitable for passing as the
294 STAT_FUNC argument to gdb_bfd_openr_iovec. */
297 gdb_bfd_iovec_fileio_fstat (struct bfd *abfd, void *stream,
300 int fd = *(int *) stream;
304 result = target_fileio_fstat (fd, sb, &target_errno);
307 errno = fileio_errno_to_host (target_errno);
308 bfd_set_error (bfd_error_system_call);
317 gdb_bfd_open (const char *name, const char *target, int fd)
322 struct gdb_bfd_cache_search search;
325 if (is_target_filename (name))
327 if (!target_filesystem_is_local ())
329 gdb_assert (fd == -1);
331 return gdb_bfd_openr_iovec (name, target,
332 gdb_bfd_iovec_fileio_open,
334 gdb_bfd_iovec_fileio_pread,
335 gdb_bfd_iovec_fileio_close,
336 gdb_bfd_iovec_fileio_fstat);
339 name += strlen (TARGET_SYSROOT_PREFIX);
342 if (gdb_bfd_cache == NULL)
343 gdb_bfd_cache = htab_create_alloc (1, hash_bfd, eq_bfd, NULL,
348 fd = gdb_open_cloexec (name, O_RDONLY | O_BINARY, 0);
351 bfd_set_error (bfd_error_system_call);
356 search.filename = name;
357 if (fstat (fd, &st) < 0)
359 /* Weird situation here. */
363 search.mtime = st.st_mtime;
365 /* Note that this must compute the same result as hash_bfd. */
366 hash = htab_hash_string (name);
367 /* Note that we cannot use htab_find_slot_with_hash here, because
368 opening the BFD may fail; and this would violate hashtab
370 abfd = htab_find_with_hash (gdb_bfd_cache, &search, hash);
378 abfd = bfd_fopen (name, target, FOPEN_RB, fd);
382 slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash, INSERT);
390 /* A helper function that releases any section data attached to the
394 free_one_bfd_section (bfd *abfd, asection *sectp, void *ignore)
396 struct gdb_bfd_section_data *sect = bfd_get_section_userdata (abfd, sectp);
398 if (sect != NULL && sect->data != NULL)
401 if (sect->map_addr != NULL)
405 res = munmap (sect->map_addr, sect->map_len);
406 gdb_assert (res == 0);
414 /* Close ABFD, and warn if that fails. */
417 gdb_bfd_close_or_warn (struct bfd *abfd)
420 char *name = bfd_get_filename (abfd);
422 bfd_map_over_sections (abfd, free_one_bfd_section, NULL);
424 ret = bfd_close (abfd);
427 warning (_("cannot close \"%s\": %s"),
428 name, bfd_errmsg (bfd_get_error ()));
436 gdb_bfd_ref (struct bfd *abfd)
438 struct gdb_bfd_data *gdata;
444 gdata = bfd_usrdata (abfd);
452 /* Ask BFD to decompress sections in bfd_get_full_section_contents. */
453 abfd->flags |= BFD_DECOMPRESS;
455 gdata = bfd_zalloc (abfd, sizeof (struct gdb_bfd_data));
457 gdata->mtime = bfd_get_mtime (abfd);
458 gdata->archive_bfd = NULL;
459 bfd_usrdata (abfd) = gdata;
461 bfd_alloc_data (abfd);
463 /* This is the first we've seen it, so add it to the hash table. */
464 slot = htab_find_slot (all_bfds, abfd, INSERT);
465 gdb_assert (slot && !*slot);
472 gdb_bfd_unref (struct bfd *abfd)
475 struct gdb_bfd_data *gdata;
476 struct gdb_bfd_cache_search search;
477 bfd *archive_bfd, *included_bfd;
482 gdata = bfd_usrdata (abfd);
483 gdb_assert (gdata->refc >= 1);
489 archive_bfd = gdata->archive_bfd;
490 search.filename = bfd_get_filename (abfd);
492 if (gdb_bfd_cache && search.filename)
494 hashval_t hash = htab_hash_string (search.filename);
497 search.mtime = gdata->mtime;
498 slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash,
502 htab_clear_slot (gdb_bfd_cache, slot);
506 VEC_iterate (bfdp, gdata->included_bfds, ix, included_bfd);
508 gdb_bfd_unref (included_bfd);
509 VEC_free (bfdp, gdata->included_bfds);
511 bfd_free_data (abfd);
512 bfd_usrdata (abfd) = NULL; /* Paranoia. */
514 htab_remove_elt (all_bfds, abfd);
516 gdb_bfd_close_or_warn (abfd);
518 gdb_bfd_unref (archive_bfd);
521 /* A helper function that returns the section data descriptor
522 associated with SECTION. If no such descriptor exists, a new one
523 is allocated and cleared. */
525 static struct gdb_bfd_section_data *
526 get_section_descriptor (asection *section)
528 struct gdb_bfd_section_data *result;
530 result = bfd_get_section_userdata (section->owner, section);
534 result = bfd_zalloc (section->owner, sizeof (*result));
535 bfd_set_section_userdata (section->owner, section, result);
544 gdb_bfd_map_section (asection *sectp, bfd_size_type *size)
547 struct gdb_bfd_section_data *descriptor;
550 gdb_assert ((sectp->flags & SEC_RELOC) == 0);
551 gdb_assert (size != NULL);
555 descriptor = get_section_descriptor (sectp);
557 /* If the data was already read for this BFD, just reuse it. */
558 if (descriptor->data != NULL)
562 if (!bfd_is_section_compressed (abfd, sectp))
564 /* The page size, used when mmapping. */
568 pagesize = getpagesize ();
570 /* Only try to mmap sections which are large enough: we don't want
571 to waste space due to fragmentation. */
573 if (bfd_get_section_size (sectp) > 4 * pagesize)
575 descriptor->size = bfd_get_section_size (sectp);
576 descriptor->data = bfd_mmap (abfd, 0, descriptor->size, PROT_READ,
577 MAP_PRIVATE, sectp->filepos,
578 &descriptor->map_addr,
579 &descriptor->map_len);
581 if ((caddr_t)descriptor->data != MAP_FAILED)
583 #if HAVE_POSIX_MADVISE
584 posix_madvise (descriptor->map_addr, descriptor->map_len,
585 POSIX_MADV_WILLNEED);
590 /* On failure, clear out the section data and try again. */
591 memset (descriptor, 0, sizeof (*descriptor));
594 #endif /* HAVE_MMAP */
596 /* Handle compressed sections, or ordinary uncompressed sections in
599 descriptor->size = bfd_get_section_size (sectp);
600 descriptor->data = NULL;
603 if (!bfd_get_full_section_contents (abfd, sectp, &data))
604 error (_("Can't read data for section '%s' in file '%s'"),
605 bfd_get_section_name (abfd, sectp),
606 bfd_get_filename (abfd));
607 descriptor->data = data;
610 gdb_assert (descriptor->data != NULL);
611 *size = descriptor->size;
612 return descriptor->data;
615 /* Return 32-bit CRC for ABFD. If successful store it to *FILE_CRC_RETURN and
616 return 1. Otherwise print a warning and return 0. ABFD seek position is
620 get_file_crc (bfd *abfd, unsigned long *file_crc_return)
622 unsigned long file_crc = 0;
624 if (bfd_seek (abfd, 0, SEEK_SET) != 0)
626 warning (_("Problem reading \"%s\" for CRC: %s"),
627 bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
633 gdb_byte buffer[8 * 1024];
636 count = bfd_bread (buffer, sizeof (buffer), abfd);
637 if (count == (bfd_size_type) -1)
639 warning (_("Problem reading \"%s\" for CRC: %s"),
640 bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
645 file_crc = bfd_calc_gnu_debuglink_crc32 (file_crc, buffer, count);
648 *file_crc_return = file_crc;
655 gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out)
657 struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
659 if (!gdata->crc_computed)
660 gdata->crc_computed = get_file_crc (abfd, &gdata->crc);
662 if (gdata->crc_computed)
663 *crc_out = gdata->crc;
664 return gdata->crc_computed;
672 gdb_bfd_fopen (const char *filename, const char *target, const char *mode,
675 bfd *result = bfd_fopen (filename, target, mode, fd);
678 gdb_bfd_ref (result);
686 gdb_bfd_openr (const char *filename, const char *target)
688 bfd *result = bfd_openr (filename, target);
691 gdb_bfd_ref (result);
699 gdb_bfd_openw (const char *filename, const char *target)
701 bfd *result = bfd_openw (filename, target);
704 gdb_bfd_ref (result);
712 gdb_bfd_openr_iovec (const char *filename, const char *target,
713 void *(*open_func) (struct bfd *nbfd,
716 file_ptr (*pread_func) (struct bfd *nbfd,
721 int (*close_func) (struct bfd *nbfd,
723 int (*stat_func) (struct bfd *abfd,
727 bfd *result = bfd_openr_iovec (filename, target,
728 open_func, open_closure,
729 pread_func, close_func, stat_func);
732 gdb_bfd_ref (result);
740 gdb_bfd_mark_parent (bfd *child, bfd *parent)
742 struct gdb_bfd_data *gdata;
745 /* No need to stash the filename here, because we also keep a
746 reference on the parent archive. */
748 gdata = bfd_usrdata (child);
749 if (gdata->archive_bfd == NULL)
751 gdata->archive_bfd = parent;
752 gdb_bfd_ref (parent);
755 gdb_assert (gdata->archive_bfd == parent);
761 gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous)
763 bfd *result = bfd_openr_next_archived_file (archive, previous);
766 gdb_bfd_mark_parent (result, archive);
774 gdb_bfd_record_inclusion (bfd *includer, bfd *includee)
776 struct gdb_bfd_data *gdata;
778 gdb_bfd_ref (includee);
779 gdata = bfd_usrdata (includer);
780 VEC_safe_push (bfdp, gdata->included_bfds, includee);
786 gdb_bfd_fdopenr (const char *filename, const char *target, int fd)
788 bfd *result = bfd_fdopenr (filename, target, fd);
791 gdb_bfd_ref (result);
798 gdb_static_assert (ARRAY_SIZE (_bfd_std_section) == 4);
803 gdb_bfd_section_index (bfd *abfd, asection *section)
807 else if (section == bfd_com_section_ptr)
808 return bfd_count_sections (abfd);
809 else if (section == bfd_und_section_ptr)
810 return bfd_count_sections (abfd) + 1;
811 else if (section == bfd_abs_section_ptr)
812 return bfd_count_sections (abfd) + 2;
813 else if (section == bfd_ind_section_ptr)
814 return bfd_count_sections (abfd) + 3;
815 return section->index;
821 gdb_bfd_count_sections (bfd *abfd)
823 return bfd_count_sections (abfd) + 4;
829 gdb_bfd_requires_relocations (bfd *abfd)
831 struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
833 if (gdata->relocation_computed == 0)
837 for (sect = abfd->sections; sect != NULL; sect = sect->next)
838 if ((sect->flags & SEC_RELOC) != 0)
840 gdata->needs_relocations = 1;
844 gdata->relocation_computed = 1;
847 return gdata->needs_relocations;
852 /* A callback for htab_traverse that prints a single BFD. */
855 print_one_bfd (void **slot, void *data)
858 struct gdb_bfd_data *gdata = bfd_usrdata (abfd);
859 struct ui_out *uiout = data;
860 struct cleanup *inner;
862 inner = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
863 ui_out_field_int (uiout, "refcount", gdata->refc);
864 ui_out_field_string (uiout, "addr", host_address_to_string (abfd));
865 ui_out_field_string (uiout, "filename", bfd_get_filename (abfd));
866 ui_out_text (uiout, "\n");
872 /* Implement the 'maint info bfd' command. */
875 maintenance_info_bfds (char *arg, int from_tty)
877 struct cleanup *cleanup;
878 struct ui_out *uiout = current_uiout;
880 cleanup = make_cleanup_ui_out_table_begin_end (uiout, 3, -1, "bfds");
881 ui_out_table_header (uiout, 10, ui_left, "refcount", "Refcount");
882 ui_out_table_header (uiout, 18, ui_left, "addr", "Address");
883 ui_out_table_header (uiout, 40, ui_left, "filename", "Filename");
885 ui_out_table_body (uiout);
886 htab_traverse (all_bfds, print_one_bfd, uiout);
888 do_cleanups (cleanup);
891 /* -Wmissing-prototypes */
892 extern initialize_file_ftype _initialize_gdb_bfd;
895 _initialize_gdb_bfd (void)
897 all_bfds = htab_create_alloc (10, htab_hash_pointer, htab_eq_pointer,
898 NULL, xcalloc, xfree);
900 add_cmd ("bfds", class_maintenance, maintenance_info_bfds, _("\
901 List the BFDs that are currently open."),
902 &maintenanceinfolist);