qemu-log: support simple pid substitution for logs
When debugging stuff that occurs over several forks it would be useful
not to keep overwriting the one logfile you've set-up. This allows a
simple %d to be included once in the logfile parameter which is
substituted with getpid().
As the test cases involve checking user output they need
g_test_trap_subprocess() support. As a result they are currently skipped
on Travis builds due to the older glib involved.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-10-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/util/log.c b/util/log.c
index 671b617..b219081 100644
--- a/util/log.c
+++ b/util/log.c
@@ -89,11 +89,28 @@
qemu_log_close();
}
}
-
+/*
+ * Allow the user to include %d in their logfile which will be
+ * substituted with the current PID. This is useful for debugging many
+ * nested linux-user tasks but will result in lots of logs.
+ */
void qemu_set_log_filename(const char *filename)
{
+ char *pidstr;
g_free(logfilename);
- logfilename = g_strdup(filename);
+
+ pidstr = strstr(filename, "%");
+ if (pidstr) {
+ /* We only accept one %d, no other format strings */
+ if (pidstr[1] != 'd' || strchr(pidstr + 2, '%')) {
+ error_report("Bad logfile format: %s", filename);
+ logfilename = NULL;
+ } else {
+ logfilename = g_strdup_printf(filename, getpid());
+ }
+ } else {
+ logfilename = g_strdup(filename);
+ }
qemu_log_close();
qemu_set_log(qemu_loglevel);
}
