[patch] Fix for PR gdb/9538 (loading of separate debuginfo and symlinks).

Paul Pluzhnikov
2012-01-12T03:07:05Z

Greetings,

Attached is a proposed fix for PR gdb/9538.

Mostly it just moves code around, and adds a "try realpath(objfile->name)
if searching with objfile->name fails."

The added test fails before the patch, and succeeds after it.

Tested on Linux/x86_64.

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.

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 01:34:01 -0000
@@ -1441,35 +1441,15 @@ show_debug_file_directory (struct ui_fil
#define DEBUG_SUBDIRECTORY ".debug"
#endif

-char *
-find_separate_debug_file_by_debuglink (struct objfile *objfile)
-{
- char *basename, *debugdir;
- char *dir = NULL;
- char *debugfile = NULL;
- char *canon_name = NULL;
- unsigned long crc32;
+static char *
+find_separate_debug_file (const char *dir, const char *debuglink,
+ unsigned long crc32, struct objfile *objfile)
+{
+ char *debugdir;
+ char *debugfile;
+ char *canon_name;
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);
i = strlen (dir);
@@ -1480,12 +1460,12 @@ find_separate_debug_file_by_debuglink (s
+ 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;
@@ -1494,7 +1474,7 @@ find_separate_debug_file_by_debuglink (s
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;
@@ -1520,7 +1500,7 @@ 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;
@@ -1536,7 +1516,7 @@ find_separate_debug_file_by_debuglink (s
debugfile[debugdir_end - debugdir] = 0;
strcat (debugfile, canon_name + strlen (gdb_sysroot));
strcat (debugfile, "/");
- strcat (debugfile, basename);
+ strcat (debugfile, debuglink);

if (separate_debug_file_exists (debugfile, crc32, objfile))
goto cleanup_return_debugfile;
@@ -1551,8 +1531,61 @@ find_separate_debug_file_by_debuglink (s

cleanup_return_debugfile:
xfree (canon_name);
- xfree (basename);
+ return debugfile;
+}
+
+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';
+}
+
+char *
+find_separate_debug_file_by_debuglink (struct objfile *objfile)
+{
+ char *debuglink;
+ char *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;
+
+ dir = xstrdup (objfile->name);
+ terminate_after_last_dir_separator (dir);
+
+ debugfile = find_separate_debug_file (dir, debuglink, crc32, objfile);
xfree (dir);
+
+ if (debugfile != NULL)
+ goto cleanup_return_debugfile;
+
+ /* For PR gdb/9538, try again with realpath. */
+ dir = lrealpath (objfile->name);
+ if (dir == NULL)
+ goto cleanup_return_debugfile;
+
+ terminate_after_last_dir_separator (dir);
+ debugfile = find_separate_debug_file (dir, debuglink, crc32, objfile);
+ xfree (dir);
+
+ cleanup_return_debugfile:
+ xfree (debuglink);
+
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 01:34:01 -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.

@@ -55,9 +55,25 @@ if [gdb_gnu_strip_debug $binfile] {
return -1
}

+#
+# PR gdb/9538. Verify that symlinked executable still finds the separate
+# debuginfo.
+#
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
+set subsubdir ${objdir}/${subdir}/pr9538
+exec mkdir ${subsubdir}
+exec ln -s ${binfile} ${subsubdir}
+gdb_load ${subsubdir}/${testfile}${EXEEXT}
+if { $gdb_file_cmd_debug_info != "debug" } then {
+ fail "No debug information found."
+}
+gdb_exit
+exec rm -rf ${subsubdir}
+
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
gdb_load ${binfile}
if { $gdb_file_cmd_debug_info != "debug" } then {
fail "No debug information found."