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>
This commit is contained in:
Alex Bennée 2016-03-15 14:30:23 +00:00 committed by Paolo Bonzini
parent 064860778b
commit f6880b7f48
2 changed files with 54 additions and 3 deletions

View File

@ -89,7 +89,37 @@ static void test_parse_zero_range(void)
g_test_trap_assert_stdout("");
g_test_trap_assert_stderr("*Failed to parse range in: 0x1000+0\n");
}
#endif
/* As the only real failure from a bad log filename path spec is
* reporting to the user we have to use the g_test_trap_subprocess
* mechanism and check no errors reported on stderr.
*/
static void test_parse_path_subprocess(void)
{
/* All these should work without issue */
qemu_set_log_filename("/tmp/qemu.log");
qemu_set_log_filename("/tmp/qemu-%d.log");
qemu_set_log_filename("/tmp/qemu.log.%d");
}
static void test_parse_path(void)
{
g_test_trap_subprocess ("/logging/parse_path/subprocess", 0, 0);
g_test_trap_assert_passed();
g_test_trap_assert_stdout("");
g_test_trap_assert_stderr("");
}
static void test_parse_invalid_path_subprocess(void)
{
qemu_set_log_filename("/tmp/qemu-%d%d.log");
}
static void test_parse_invalid_path(void)
{
g_test_trap_subprocess ("/logging/parse_invalid_path/subprocess", 0, 0);
g_test_trap_assert_passed();
g_test_trap_assert_stdout("");
g_test_trap_assert_stderr("Bad logfile format: /tmp/qemu-%d%d.log\n");
}
#endif /* CONFIG_HAS_GLIB_SUBPROCESS_TESTS */
int main(int argc, char **argv)
{
@ -101,6 +131,10 @@ int main(int argc, char **argv)
g_test_add_func("/logging/parse_invalid_range", test_parse_invalid_range);
g_test_add_func("/logging/parse_zero_range/subprocess", test_parse_zero_range_subprocess);
g_test_add_func("/logging/parse_zero_range", test_parse_zero_range);
g_test_add_func("/logging/parse_path", test_parse_path);
g_test_add_func("/logging/parse_path/subprocess", test_parse_path_subprocess);
g_test_add_func("/logging/parse_invalid_path", test_parse_invalid_path);
g_test_add_func("/logging/parse_invalid_path/subprocess", test_parse_invalid_path_subprocess);
#endif
return g_test_run();

View File

@ -89,11 +89,28 @@ void do_qemu_set_log(int log_flags, bool use_own_buffers)
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);
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);
}