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build-id.c
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1/* build-id-related functions.
2
3 Copyright (C) 1991-2023 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 "gdbsupport/gdb_vecs.h"
25#include "symfile.h"
26#include "objfiles.h"
27#include "filenames.h"
28#include "gdbcore.h"
29#include "cli/cli-style.h"
30
31/* See build-id.h. */
32
33const struct bfd_build_id *
35{
36 /* Dynamic objfiles such as ones created by JIT reader API
37 have no underlying bfd structure (that is, objfile->obfd
38 is NULL). */
39 if (abfd == nullptr)
40 return nullptr;
41
42 if (!bfd_check_format (abfd, bfd_object)
43 && !bfd_check_format (abfd, bfd_core))
44 return NULL;
45
46 if (abfd->build_id != NULL)
47 return abfd->build_id;
48
49 /* No build-id */
50 return NULL;
51}
52
53/* See build-id.h. */
54
55int
56build_id_verify (bfd *abfd, size_t check_len, const bfd_byte *check)
57{
58 const struct bfd_build_id *found;
59 int retval = 0;
60
61 found = build_id_bfd_get (abfd);
62
63 if (found == NULL)
64 warning (_("File \"%s\" has no build-id, file skipped"),
65 bfd_get_filename (abfd));
66 else if (found->size != check_len
67 || memcmp (found->data, check, found->size) != 0)
68 warning (_("File \"%s\" has a different build-id, file skipped"),
69 bfd_get_filename (abfd));
70 else
71 retval = 1;
72
73 return retval;
74}
75
76/* Helper for build_id_to_debug_bfd. LINK is a path to a potential
77 build-id-based separate debug file, potentially a symlink to the real file.
78 If the file exists and matches BUILD_ID, return a BFD reference to it. */
79
80static gdb_bfd_ref_ptr
81build_id_to_debug_bfd_1 (const std::string &link, size_t build_id_len,
82 const bfd_byte *build_id)
83{
85 {
86 gdb_printf (gdb_stdlog, _(" Trying %s..."), link.c_str ());
88 }
89
90 /* lrealpath() is expensive even for the usually non-existent files. */
91 gdb::unique_xmalloc_ptr<char> filename_holder;
92 const char *filename = nullptr;
93 if (startswith (link, TARGET_SYSROOT_PREFIX))
94 filename = link.c_str ();
95 else if (access (link.c_str (), F_OK) == 0)
96 {
97 filename_holder.reset (lrealpath (link.c_str ()));
98 filename = filename_holder.get ();
99 }
100
101 if (filename == NULL)
102 {
105 _(" no, unable to compute real path\n"));
106
107 return {};
108 }
109
110 /* We expect to be silent on the non-existing files. */
111 gdb_bfd_ref_ptr debug_bfd = gdb_bfd_open (filename, gnutarget);
112
113 if (debug_bfd == NULL)
114 {
116 gdb_printf (gdb_stdlog, _(" no, unable to open.\n"));
117
118 return {};
119 }
120
121 if (!build_id_verify (debug_bfd.get(), build_id_len, build_id))
122 {
124 gdb_printf (gdb_stdlog, _(" no, build-id does not match.\n"));
125
126 return {};
127 }
128
130 gdb_printf (gdb_stdlog, _(" yes!\n"));
131
132 return debug_bfd;
133}
134
135/* Common code for finding BFDs of a given build-id. This function
136 works with both debuginfo files (SUFFIX == ".debug") and executable
137 files (SUFFIX == ""). */
138
139static gdb_bfd_ref_ptr
140build_id_to_bfd_suffix (size_t build_id_len, const bfd_byte *build_id,
141 const char *suffix)
142{
143 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
144 cause "/.build-id/..." lookups. */
145
146 std::vector<gdb::unique_xmalloc_ptr<char>> debugdir_vec
147 = dirnames_to_char_ptr_vec (debug_file_directory.c_str ());
148
149 for (const gdb::unique_xmalloc_ptr<char> &debugdir : debugdir_vec)
150 {
151 const gdb_byte *data = build_id;
152 size_t size = build_id_len;
153
154 /* Compute where the file named after the build-id would be.
155
156 If debugdir is "/usr/lib/debug" and the build-id is abcdef, this will
157 give "/usr/lib/debug/.build-id/ab/cdef.debug". */
158 std::string link = debugdir.get ();
159 link += "/.build-id/";
160
161 if (size > 0)
162 {
163 size--;
164 string_appendf (link, "%02x/", (unsigned) *data++);
165 }
166
167 while (size-- > 0)
168 string_appendf (link, "%02x", (unsigned) *data++);
169
170 link += suffix;
171
172 gdb_bfd_ref_ptr debug_bfd
173 = build_id_to_debug_bfd_1 (link, build_id_len, build_id);
174 if (debug_bfd != NULL)
175 return debug_bfd;
176
177 /* Try to look under the sysroot as well. If the sysroot is
178 "/the/sysroot", it will give
179 "/the/sysroot/usr/lib/debug/.build-id/ab/cdef.debug". */
180
181 if (!gdb_sysroot.empty ())
182 {
183 link = gdb_sysroot + link;
184 debug_bfd = build_id_to_debug_bfd_1 (link, build_id_len, build_id);
185 if (debug_bfd != NULL)
186 return debug_bfd;
187 }
188 }
189
190 return {};
191}
192
193/* See build-id.h. */
194
196build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
197{
198 return build_id_to_bfd_suffix (build_id_len, build_id, ".debug");
199}
200
201/* See build-id.h. */
202
204build_id_to_exec_bfd (size_t build_id_len, const bfd_byte *build_id)
205{
206 return build_id_to_bfd_suffix (build_id_len, build_id, "");
207}
208
209/* See build-id.h. */
210
211std::string
213 deferred_warnings *warnings)
214{
215 const struct bfd_build_id *build_id;
216
217 build_id = build_id_bfd_get (objfile->obfd.get ());
218 if (build_id != NULL)
219 {
222 _("\nLooking for separate debug info (build-id) for "
223 "%s\n"), objfile_name (objfile));
224
225 gdb_bfd_ref_ptr abfd (build_id_to_debug_bfd (build_id->size,
226 build_id->data));
227 /* Prevent looping on a stripped .debug file. */
228 if (abfd != NULL
229 && filename_cmp (bfd_get_filename (abfd.get ()),
230 objfile_name (objfile)) == 0)
231 {
233 gdb_printf (gdb_stdlog, "\"%s\": separate debug info file has no "
234 "debug info", bfd_get_filename (abfd.get ()));
235 warnings->warn (_("\"%ps\": separate debug info file has no "
236 "debug info"),
238 bfd_get_filename (abfd.get ())));
239 }
240 else if (abfd != NULL)
241 return std::string (bfd_get_filename (abfd.get ()));
242 }
243
244 return std::string ();
245}
static gdb_bfd_ref_ptr build_id_to_debug_bfd_1(const std::string &link, size_t build_id_len, const bfd_byte *build_id)
Definition build-id.c:81
std::string find_separate_debug_file_by_buildid(struct objfile *objfile, deferred_warnings *warnings)
Definition build-id.c:212
int build_id_verify(bfd *abfd, size_t check_len, const bfd_byte *check)
Definition build-id.c:56
gdb_bfd_ref_ptr build_id_to_exec_bfd(size_t build_id_len, const bfd_byte *build_id)
Definition build-id.c:204
static gdb_bfd_ref_ptr build_id_to_bfd_suffix(size_t build_id_len, const bfd_byte *build_id, const char *suffix)
Definition build-id.c:140
gdb_bfd_ref_ptr build_id_to_debug_bfd(size_t build_id_len, const bfd_byte *build_id)
Definition build-id.c:196
const struct bfd_build_id * build_id_bfd_get(bfd *abfd)
Definition build-id.c:34
ui_file_style style() const
Definition cli-style.c:169
cli_style_option file_name_style
const char * gnutarget
Definition corefile.c:405
std::string debug_file_directory
Definition symfile.c:1354
std::string gdb_sysroot
Definition main.c:64
gdb_bfd_ref_ptr gdb_bfd_open(const char *name, const char *target, int fd, bool warn_if_slow)
Definition gdb_bfd.c:473
#define TARGET_SYSROOT_PREFIX
Definition gdb_bfd.h:41
gdb::ref_ptr< struct bfd, gdb_bfd_ref_policy > gdb_bfd_ref_ptr
Definition gdb_bfd.h:79
size_t size
Definition go32-nat.c:239
const char * objfile_name(const struct objfile *objfile)
Definition objfiles.c:1259
void warn(const char *format,...) ATTRIBUTE_PRINTF(2
gdb_bfd_ref_ptr obfd
Definition objfiles.h:740
bool separate_debug_file_debug
Definition symfile.c:1235
static styled_string_s * styled_string(const ui_file_style &style, const char *str, styled_string_s &&tmp={})
Definition ui-out.h:151
void gdb_printf(struct ui_file *stream, const char *format,...)
Definition utils.c:1886
void gdb_flush(struct ui_file *stream)
Definition utils.c:1498
#define gdb_stdlog
Definition utils.h:190
static void check(BOOL ok, const char *file, int line)