[patch] Fix for PR gdb/9538 (loading of separate debuginfo and symlinks).
Paul Pluzhnikov
ppluzhnikov@google.com
Thu Jan 12 20:59:00 GMT 2012
On Thu, Jan 12, 2012 at 9:23 AM, Doug Evans <dje@google.com> wrote:
> The symfile.c change is ok with me, modulo can you add comments for
> each of the functions?
Done.
I've also refactored the code a bit more to avoid searching the same
directory again.
> [caveat: I think it doesn't properly handle paths with dos drives, but
> the code already has that problem, so no requirement to fix that in
> this patch]
I don't think ".gnu_debuglink" is supported on non-ELF platforms, so not
handling DOS drives is likely not a problem.
> I see sepdebug.exp uses remote_exec so best use that instead of exec.
Done.
> Also, I'm not sure what the portability requirements are w.r.t. symlinks.
> Probably best to watch for errors in the "ln -s" and handle appropriately.
The test exits if gdb_gnu_strip_debug fails. I don't believe it will
currently succeed on any platform without symlinks.
Testing for errors will just add noise.
> [Even better, is there a utility routine that will create a symlink?
> All the portability concerns could be tucked away in there.]
I didn't find one.
> Also, can you use clean_restart instead of the gdb_exit/gdb_start/... sequence?
Done.
Thanks,
--
Paul Pluzhnikov
2012-01-11 Paul Pluzhnikov <ppluzhnikov@google.com>
PR gdb/9538
* symfile.c (find_separate_debug_file): New function.
(terminate_after_last_dir_separator): Likewise.
(find_separate_debug_file_by_debuglink): Also try realpath.
testsuite/ChangeLog:
PR gdb/9538
* gdb.base/sepdebug.exp: New test.
-------------- next part --------------
Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.325
diff -u -p -r1.325 symfile.c
--- symfile.c 12 Jan 2012 00:00:01 -0000 1.325
+++ symfile.c 12 Jan 2012 20:29:53 -0000
@@ -1441,63 +1441,48 @@ show_debug_file_directory (struct ui_fil
#define DEBUG_SUBDIRECTORY ".debug"
#endif
-char *
-find_separate_debug_file_by_debuglink (struct objfile *objfile)
+/* Find a separate debuginfo file for OBJFILE, using DIR as the directory
+ where the original file resides (may not be the same as
+ dirname(objfile->name) due to symlinks), and DEBUGLINK as the file we are
+ looking for. Returns the name of the debuginfo, of NULL. */
+
+static char *
+find_separate_debug_file (const char *dir,
+ const char *canon_dir,
+ const char *debuglink,
+ unsigned long crc32, struct objfile *objfile)
{
- char *basename, *debugdir;
- char *dir = NULL;
- char *debugfile = NULL;
- char *canon_name = NULL;
- unsigned long crc32;
+ char *debugdir;
+ char *debugfile;
int i;
- basename = get_debug_link_info (objfile, &crc32);
-
- if (basename == NULL)
- /* There's no separate debug info, hence there's no way we could
- load it => no warning. */
- goto cleanup_return_debugfile;
-
- dir = xstrdup (objfile->name);
-
- /* Strip off the final filename part, leaving the directory name,
- followed by a slash. The directory can be relative or absolute. */
- for (i = strlen(dir) - 1; i >= 0; i--)
- {
- if (IS_DIR_SEPARATOR (dir[i]))
- break;
- }
- /* If I is -1 then no directory is present there and DIR will be "". */
- dir[i+1] = '\0';
-
- /* Set I to max (strlen (canon_name), strlen (dir)). */
- canon_name = lrealpath (dir);
+ /* Set I to max (strlen (canon_dir), strlen (dir)). */
i = strlen (dir);
- if (canon_name && strlen (canon_name) > i)
- i = strlen (canon_name);
+ if (canon_dir && strlen (canon_dir) > i)
+ i = strlen (canon_dir);
debugfile = xmalloc (strlen (debug_file_directory) + 1
+ i
+ strlen (DEBUG_SUBDIRECTORY)
+ strlen ("/")
- + strlen (basename)
+ + strlen (debuglink)
+ 1);
/* First try in the same directory as the original file. */
strcpy (debugfile, dir);
- strcat (debugfile, basename);
+ strcat (debugfile, debuglink);
if (separate_debug_file_exists (debugfile, crc32, objfile))
- goto cleanup_return_debugfile;
+ return debugfile;
/* Then try in the subdirectory named DEBUG_SUBDIRECTORY. */
strcpy (debugfile, dir);
strcat (debugfile, DEBUG_SUBDIRECTORY);
strcat (debugfile, "/");
- strcat (debugfile, basename);
+ strcat (debugfile, debuglink);
if (separate_debug_file_exists (debugfile, crc32, objfile))
- goto cleanup_return_debugfile;
+ return debugfile;
/* Then try in the global debugfile directories.
@@ -1520,26 +1505,26 @@ find_separate_debug_file_by_debuglink (s
debugfile[debugdir_end - debugdir] = 0;
strcat (debugfile, "/");
strcat (debugfile, dir);
- strcat (debugfile, basename);
+ strcat (debugfile, debuglink);
if (separate_debug_file_exists (debugfile, crc32, objfile))
- goto cleanup_return_debugfile;
+ return debugfile;
/* If the file is in the sysroot, try using its base path in the
global debugfile directory. */
- if (canon_name
- && filename_ncmp (canon_name, gdb_sysroot,
+ if (canon_dir != NULL
+ && filename_ncmp (canon_dir, gdb_sysroot,
strlen (gdb_sysroot)) == 0
- && IS_DIR_SEPARATOR (canon_name[strlen (gdb_sysroot)]))
+ && IS_DIR_SEPARATOR (canon_dir[strlen (gdb_sysroot)]))
{
memcpy (debugfile, debugdir, debugdir_end - debugdir);
debugfile[debugdir_end - debugdir] = 0;
- strcat (debugfile, canon_name + strlen (gdb_sysroot));
+ strcat (debugfile, canon_dir + strlen (gdb_sysroot));
strcat (debugfile, "/");
- strcat (debugfile, basename);
+ strcat (debugfile, debuglink);
if (separate_debug_file_exists (debugfile, crc32, objfile))
- goto cleanup_return_debugfile;
+ return debugfile;
}
debugdir = debugdir_end;
@@ -1547,12 +1532,80 @@ find_separate_debug_file_by_debuglink (s
while (*debugdir != 0);
xfree (debugfile);
- debugfile = NULL;
+ return NULL;
+}
+
+/* Modify PATH to contain only "directory/" part of PATH.
+ If there were no, directory separators in PATH, PATH will be empty
+ string on return. */
+
+static void
+terminate_after_last_dir_separator (char *path)
+{
+ int i;
+
+ /* Strip off the final filename part, leaving the directory name,
+ followed by a slash. The directory can be relative or absolute. */
+ for (i = strlen(path) - 1; i >= 0; i--)
+ {
+ if (IS_DIR_SEPARATOR (path[i]))
+ break;
+ }
+ /* If I is -1 then no directory is present there and DIR will be "". */
+ path[i+1] = '\0';
+}
+
+/* Find separate debuginfo for OBJFILE (using .gnu_debuglink section).
+ Returns pathname, or NULL. */
+
+char *
+find_separate_debug_file_by_debuglink (struct objfile *objfile)
+{
+ char *debuglink;
+ char *dir1, *dir2, *canon_dir;
+ char *debugfile;
+ unsigned long crc32;
+
+ debuglink = get_debug_link_info (objfile, &crc32);
+
+ if (debuglink == NULL)
+ /* There's no separate debug info, hence there's no way we could
+ load it => no warning. */
+ return NULL;
+
+ dir1 = xstrdup (objfile->name);
+ terminate_after_last_dir_separator (dir1);
+ canon_dir = lrealpath (dir1);
+
+ debugfile = find_separate_debug_file (dir1, canon_dir, debuglink,
+ crc32, objfile);
+ xfree (canon_dir);
+
+ if (debugfile != NULL)
+ goto cleanup1;
+
+ /* For PR gdb/9538, try again with realpath (if different from the
+ original). */
+ dir2 = lrealpath (objfile->name);
+ if (dir2 == NULL)
+ goto cleanup1;
+
+ terminate_after_last_dir_separator (dir2);
+ if (strcmp (dir1, dir2) == 0)
+ /* Same directory, no point retrying. */
+ goto cleanup2;
+
+ canon_dir = lrealpath (dir2);
+ debugfile = find_separate_debug_file (dir2, canon_dir, debuglink,
+ crc32, objfile);
+ xfree (canon_dir);
+
+ cleanup2:
+ xfree (dir2);
+ cleanup1:
+ xfree (dir1);
+ xfree (debuglink);
-cleanup_return_debugfile:
- xfree (canon_name);
- xfree (basename);
- xfree (dir);
return debugfile;
}
Index: testsuite/gdb.base/sepdebug.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.base/sepdebug.exp,v
retrieving revision 1.33
diff -u -p -r1.33 sepdebug.exp
--- testsuite/gdb.base/sepdebug.exp 4 Jan 2012 08:17:46 -0000 1.33
+++ testsuite/gdb.base/sepdebug.exp 12 Jan 2012 20:29:53 -0000
@@ -45,7 +45,7 @@ if { [gdb_compile "${srcdir}/${subdir}/
# Note: the procedure gdb_gnu_strip_debug will produce an executable called
# ${binfile}, which is just like the executable ($binfile) but without
-# the debuginfo. Instead $binfile has a .gnudebuglink section which contains
+# the debuginfo. Instead $binfile has a .gnu_debuglink section which contains
# the name of a debuginfo only file. This file will be stored in the
# gdb.base/ subdirectory.
@@ -55,10 +55,26 @@ if [gdb_gnu_strip_debug $binfile] {
return -1
}
+#
+# PR gdb/9538. Verify that symlinked executable still finds the separate
+# debuginfo.
+#
+set old_subdir ${subdir}
+set subdir ${subdir}/pr9538
+remote_exec build "mkdir ${subdir}"
+remote_exec build "ln -s ${binfile} ${subdir}"
+clean_restart ${testfile}${EXEEXT}
+if { $gdb_file_cmd_debug_info != "debug" } then {
+ fail "No debug information found."
+}
+
+# make sure we are not holding subdir/binary open.
gdb_exit
-gdb_start
-gdb_reinitialize_dir $srcdir/$subdir
-gdb_load ${binfile}
+
+remote_exec build "rm -rf ${subdir}"
+set subdir ${old_subdir}
+
+clean_restart ${testfile}${EXEEXT}
if { $gdb_file_cmd_debug_info != "debug" } then {
fail "No debug information found."
}
More information about the Gdb-patches
mailing list