| 1 | /* build-id-related functions. |
| 2 | |
| 3 | Copyright (C) 1991-2015 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 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. |
| 11 | |
| 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. |
| 16 | |
| 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/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "bfd.h" |
| 22 | #include "gdb_bfd.h" |
| 23 | #include "build-id.h" |
| 24 | #include "gdb_vecs.h" |
| 25 | #include "symfile.h" |
| 26 | #include "objfiles.h" |
| 27 | #include "filenames.h" |
| 28 | #include "gdbcore.h" |
| 29 | |
| 30 | /* See build-id.h. */ |
| 31 | |
| 32 | const struct bfd_build_id * |
| 33 | build_id_bfd_get (bfd *abfd) |
| 34 | { |
| 35 | if (!bfd_check_format (abfd, bfd_object)) |
| 36 | return NULL; |
| 37 | |
| 38 | if (abfd->build_id != NULL) |
| 39 | return abfd->build_id; |
| 40 | |
| 41 | /* No build-id */ |
| 42 | return NULL; |
| 43 | } |
| 44 | |
| 45 | /* See build-id.h. */ |
| 46 | |
| 47 | int |
| 48 | build_id_verify (bfd *abfd, size_t check_len, const bfd_byte *check) |
| 49 | { |
| 50 | const struct bfd_build_id *found; |
| 51 | int retval = 0; |
| 52 | |
| 53 | found = build_id_bfd_get (abfd); |
| 54 | |
| 55 | if (found == NULL) |
| 56 | warning (_("File \"%s\" has no build-id, file skipped"), |
| 57 | bfd_get_filename (abfd)); |
| 58 | else if (found->size != check_len |
| 59 | || memcmp (found->data, check, found->size) != 0) |
| 60 | warning (_("File \"%s\" has a different build-id, file skipped"), |
| 61 | bfd_get_filename (abfd)); |
| 62 | else |
| 63 | retval = 1; |
| 64 | |
| 65 | return retval; |
| 66 | } |
| 67 | |
| 68 | /* See build-id.h. */ |
| 69 | |
| 70 | bfd * |
| 71 | build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id) |
| 72 | { |
| 73 | char *link, *debugdir; |
| 74 | VEC (char_ptr) *debugdir_vec; |
| 75 | struct cleanup *back_to; |
| 76 | int ix; |
| 77 | bfd *abfd = NULL; |
| 78 | int alloc_len; |
| 79 | |
| 80 | /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */ |
| 81 | alloc_len = (strlen (debug_file_directory) |
| 82 | + (sizeof "/.build-id/" - 1) + 1 |
| 83 | + 2 * build_id_len + (sizeof ".debug" - 1) + 1); |
| 84 | link = (char *) alloca (alloc_len); |
| 85 | |
| 86 | /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will |
| 87 | cause "/.build-id/..." lookups. */ |
| 88 | |
| 89 | debugdir_vec = dirnames_to_char_ptr_vec (debug_file_directory); |
| 90 | back_to = make_cleanup_free_char_ptr_vec (debugdir_vec); |
| 91 | |
| 92 | for (ix = 0; VEC_iterate (char_ptr, debugdir_vec, ix, debugdir); ++ix) |
| 93 | { |
| 94 | size_t debugdir_len = strlen (debugdir); |
| 95 | const gdb_byte *data = build_id; |
| 96 | size_t size = build_id_len; |
| 97 | char *s; |
| 98 | char *filename = NULL; |
| 99 | struct cleanup *inner; |
| 100 | |
| 101 | memcpy (link, debugdir, debugdir_len); |
| 102 | s = &link[debugdir_len]; |
| 103 | s += sprintf (s, "/.build-id/"); |
| 104 | if (size > 0) |
| 105 | { |
| 106 | size--; |
| 107 | s += sprintf (s, "%02x", (unsigned) *data++); |
| 108 | } |
| 109 | if (size > 0) |
| 110 | *s++ = '/'; |
| 111 | while (size-- > 0) |
| 112 | s += sprintf (s, "%02x", (unsigned) *data++); |
| 113 | strcpy (s, ".debug"); |
| 114 | |
| 115 | /* lrealpath() is expensive even for the usually non-existent files. */ |
| 116 | if (access (link, F_OK) == 0) |
| 117 | filename = lrealpath (link); |
| 118 | |
| 119 | if (filename == NULL) |
| 120 | continue; |
| 121 | |
| 122 | /* We expect to be silent on the non-existing files. */ |
| 123 | inner = make_cleanup (xfree, filename); |
| 124 | abfd = gdb_bfd_open (filename, gnutarget, -1); |
| 125 | do_cleanups (inner); |
| 126 | |
| 127 | if (abfd == NULL) |
| 128 | continue; |
| 129 | |
| 130 | if (build_id_verify (abfd, build_id_len, build_id)) |
| 131 | break; |
| 132 | |
| 133 | gdb_bfd_unref (abfd); |
| 134 | abfd = NULL; |
| 135 | } |
| 136 | |
| 137 | do_cleanups (back_to); |
| 138 | return abfd; |
| 139 | } |
| 140 | |
| 141 | /* See build-id.h. */ |
| 142 | |
| 143 | char * |
| 144 | find_separate_debug_file_by_buildid (struct objfile *objfile) |
| 145 | { |
| 146 | const struct bfd_build_id *build_id; |
| 147 | |
| 148 | build_id = build_id_bfd_get (objfile->obfd); |
| 149 | if (build_id != NULL) |
| 150 | { |
| 151 | bfd *abfd; |
| 152 | |
| 153 | abfd = build_id_to_debug_bfd (build_id->size, build_id->data); |
| 154 | /* Prevent looping on a stripped .debug file. */ |
| 155 | if (abfd != NULL |
| 156 | && filename_cmp (bfd_get_filename (abfd), |
| 157 | objfile_name (objfile)) == 0) |
| 158 | { |
| 159 | warning (_("\"%s\": separate debug info file has no debug info"), |
| 160 | bfd_get_filename (abfd)); |
| 161 | gdb_bfd_unref (abfd); |
| 162 | } |
| 163 | else if (abfd != NULL) |
| 164 | { |
| 165 | char *result = xstrdup (bfd_get_filename (abfd)); |
| 166 | |
| 167 | gdb_bfd_unref (abfd); |
| 168 | return result; |
| 169 | } |
| 170 | } |
| 171 | return NULL; |
| 172 | } |