1 /* build-id-related functions. 2 3 Copyright (C) 1991-2016 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 } 173