/* build-id-related functions.
- Copyright (C) 1991-2014 Free Software Foundation, Inc.
+ Copyright (C) 1991-2020 Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "bfd.h"
-#include "elf-bfd.h"
#include "gdb_bfd.h"
#include "build-id.h"
-#include "gdb_vecs.h"
+#include "gdbsupport/gdb_vecs.h"
#include "symfile.h"
#include "objfiles.h"
#include "filenames.h"
+#include "gdbcore.h"
-/* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
+/* See build-id.h. */
-static const struct elf_build_id *
+const struct bfd_build_id *
build_id_bfd_get (bfd *abfd)
{
if (!bfd_check_format (abfd, bfd_object)
- || bfd_get_flavour (abfd) != bfd_target_elf_flavour
- /* Although this is ELF_specific, it is safe to do in generic
- code because it does not rely on any ELF-specific symbols at
- link time, and if the ELF code is not available in BFD, then
- ABFD will not have the ELF flavour. */
- || elf_tdata (abfd)->build_id == NULL)
+ && !bfd_check_format (abfd, bfd_core))
return NULL;
- return elf_tdata (abfd)->build_id;
+ if (abfd->build_id != NULL)
+ return abfd->build_id;
+
+ /* No build-id */
+ return NULL;
}
/* See build-id.h. */
int
build_id_verify (bfd *abfd, size_t check_len, const bfd_byte *check)
{
- const struct elf_build_id *found;
+ const struct bfd_build_id *found;
int retval = 0;
found = build_id_bfd_get (abfd);
return retval;
}
-/* See build-id.h. */
+/* Helper for build_id_to_debug_bfd. LINK is a path to a potential
+ build-id-based separate debug file, potentially a symlink to the real file.
+ If the file exists and matches BUILD_ID, return a BFD reference to it. */
-bfd *
-build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
+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)
{
- char *link, *debugdir;
- VEC (char_ptr) *debugdir_vec;
- struct cleanup *back_to;
- int ix;
- bfd *abfd = NULL;
+ if (separate_debug_file_debug)
+ {
+ printf_unfiltered (_(" Trying %s..."), link.c_str ());
+ gdb_flush (gdb_stdout);
+ }
- /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
- link = alloca (strlen (debug_file_directory) + (sizeof "/.build-id/" - 1) + 1
- + 2 * build_id_len + (sizeof ".debug" - 1) + 1);
+ /* lrealpath() is expensive even for the usually non-existent files. */
+ gdb::unique_xmalloc_ptr<char> filename;
+ if (access (link.c_str (), F_OK) == 0)
+ filename.reset (lrealpath (link.c_str ()));
+ if (filename == NULL)
+ {
+ if (separate_debug_file_debug)
+ printf_unfiltered (_(" no, unable to compute real path\n"));
+
+ return {};
+ }
+
+ /* We expect to be silent on the non-existing files. */
+ gdb_bfd_ref_ptr debug_bfd = gdb_bfd_open (filename.get (), gnutarget, -1);
+
+ if (debug_bfd == NULL)
+ {
+ if (separate_debug_file_debug)
+ printf_unfiltered (_(" no, unable to open.\n"));
+
+ return {};
+ }
+
+ if (!build_id_verify (debug_bfd.get(), build_id_len, build_id))
+ {
+ if (separate_debug_file_debug)
+ printf_unfiltered (_(" no, build-id does not match.\n"));
+
+ return {};
+ }
+
+ if (separate_debug_file_debug)
+ printf_unfiltered (_(" yes!\n"));
+
+ return debug_bfd;
+}
+
+/* Common code for finding BFDs of a given build-id. This function
+ works with both debuginfo files (SUFFIX == ".debug") and executable
+ files (SUFFIX == ""). */
+
+static gdb_bfd_ref_ptr
+build_id_to_bfd_suffix (size_t build_id_len, const bfd_byte *build_id,
+ const char *suffix)
+{
/* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
cause "/.build-id/..." lookups. */
- debugdir_vec = dirnames_to_char_ptr_vec (debug_file_directory);
- back_to = make_cleanup_free_char_ptr_vec (debugdir_vec);
+ std::vector<gdb::unique_xmalloc_ptr<char>> debugdir_vec
+ = dirnames_to_char_ptr_vec (debug_file_directory);
- for (ix = 0; VEC_iterate (char_ptr, debugdir_vec, ix, debugdir); ++ix)
+ for (const gdb::unique_xmalloc_ptr<char> &debugdir : debugdir_vec)
{
- size_t debugdir_len = strlen (debugdir);
const gdb_byte *data = build_id;
size_t size = build_id_len;
- char *s;
- char *filename = NULL;
- memcpy (link, debugdir, debugdir_len);
- s = &link[debugdir_len];
- s += sprintf (s, "/.build-id/");
+ /* Compute where the file named after the build-id would be.
+
+ If debugdir is "/usr/lib/debug" and the build-id is abcdef, this will
+ give "/usr/lib/debug/.build-id/ab/cdef.debug". */
+ std::string link = debugdir.get ();
+ link += "/.build-id/";
+
if (size > 0)
{
size--;
- s += sprintf (s, "%02x", (unsigned) *data++);
+ string_appendf (link, "%02x/", (unsigned) *data++);
}
- if (size > 0)
- *s++ = '/';
- while (size-- > 0)
- s += sprintf (s, "%02x", (unsigned) *data++);
- strcpy (s, ".debug");
- /* lrealpath() is expensive even for the usually non-existent files. */
- if (access (link, F_OK) == 0)
- filename = lrealpath (link);
+ while (size-- > 0)
+ string_appendf (link, "%02x", (unsigned) *data++);
- if (filename == NULL)
- continue;
+ link += suffix;
- /* We expect to be silent on the non-existing files. */
- abfd = gdb_bfd_open_maybe_remote (filename);
- if (abfd == NULL)
- continue;
+ gdb_bfd_ref_ptr debug_bfd
+ = build_id_to_debug_bfd_1 (link, build_id_len, build_id);
+ if (debug_bfd != NULL)
+ return debug_bfd;
- if (build_id_verify (abfd, build_id_len, build_id))
- break;
+ /* Try to look under the sysroot as well. If the sysroot is
+ "/the/sysroot", it will give
+ "/the/sysroot/usr/lib/debug/.build-id/ab/cdef.debug".
- gdb_bfd_unref (abfd);
- abfd = NULL;
+ Don't do it if the sysroot is the target system ("target:"). It
+ could work in theory, but the lrealpath in build_id_to_debug_bfd_1
+ only works with local paths. */
+ if (strcmp (gdb_sysroot, TARGET_SYSROOT_PREFIX) != 0)
+ {
+ link = gdb_sysroot + link;
+ debug_bfd = build_id_to_debug_bfd_1 (link, build_id_len, build_id);
+ if (debug_bfd != NULL)
+ return debug_bfd;
+ }
}
- do_cleanups (back_to);
- return abfd;
+ return {};
+}
+
+/* See build-id.h. */
+
+gdb_bfd_ref_ptr
+build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id)
+{
+ return build_id_to_bfd_suffix (build_id_len, build_id, ".debug");
+}
+
+/* See build-id.h. */
+
+gdb_bfd_ref_ptr
+build_id_to_exec_bfd (size_t build_id_len, const bfd_byte *build_id)
+{
+ return build_id_to_bfd_suffix (build_id_len, build_id, "");
}
/* See build-id.h. */
-char *
+std::string
find_separate_debug_file_by_buildid (struct objfile *objfile)
{
- const struct elf_build_id *build_id;
+ const struct bfd_build_id *build_id;
build_id = build_id_bfd_get (objfile->obfd);
if (build_id != NULL)
{
- bfd *abfd;
+ if (separate_debug_file_debug)
+ printf_unfiltered (_("\nLooking for separate debug info (build-id) for "
+ "%s\n"), objfile_name (objfile));
- abfd = build_id_to_debug_bfd (build_id->size, build_id->data);
+ gdb_bfd_ref_ptr abfd (build_id_to_debug_bfd (build_id->size,
+ build_id->data));
/* Prevent looping on a stripped .debug file. */
if (abfd != NULL
- && filename_cmp (bfd_get_filename (abfd),
+ && filename_cmp (bfd_get_filename (abfd.get ()),
objfile_name (objfile)) == 0)
- {
- warning (_("\"%s\": separate debug info file has no debug info"),
- bfd_get_filename (abfd));
- gdb_bfd_unref (abfd);
- }
+ warning (_("\"%s\": separate debug info file has no debug info"),
+ bfd_get_filename (abfd.get ()));
else if (abfd != NULL)
- {
- char *result = xstrdup (bfd_get_filename (abfd));
-
- gdb_bfd_unref (abfd);
- return result;
- }
+ return std::string (bfd_get_filename (abfd.get ()));
}
- return NULL;
+
+ return std::string ();
}