1#include "time_impl.h"
2#include <errno.h>
3
4time_t mktime(struct tm *tm)
5{
6	struct tm new;
7	long opp;
8	long long t = __tm_to_secs(tm);
9
10	__secs_to_zone(t, 1, &new.tm_isdst, &new.__tm_gmtoff, &opp, &new.__tm_zone);
11
12	if (tm->tm_isdst>=0 && new.tm_isdst!=tm->tm_isdst)
13		t -= opp - new.__tm_gmtoff;
14
15	t -= new.__tm_gmtoff;
16	if ((time_t)t != t) goto error;
17
18	__secs_to_zone(t, 0, &new.tm_isdst, &new.__tm_gmtoff, &opp, &new.__tm_zone);
19
20	if (__secs_to_tm(t + new.__tm_gmtoff, &new) < 0) goto error;
21
22	*tm = new;
23	return t;
24
25error:
26	errno = EOVERFLOW;
27	return -1;
28}
29