1 #include "time_impl.h"
2 #include <errno.h>
3 #include <limits.h>
4
__localtime_r(const time_t * restrict t,struct tm * restrict tm)5 struct tm *__localtime_r(const time_t *restrict t, struct tm *restrict tm)
6 {
7 /* Reject time_t values whose year would overflow int because
8 * __secs_to_zone cannot safely handle them. */
9 if (*t < INT_MIN * 31622400LL || *t > INT_MAX * 31622400LL) {
10 errno = EOVERFLOW;
11 return 0;
12 }
13 __secs_to_zone(*t, 0, &tm->tm_isdst, &tm->__tm_gmtoff, 0, &tm->__tm_zone, TZ_USE_ENV);
14 if (__secs_to_tm((long long)*t + tm->__tm_gmtoff, tm) < 0) {
15 errno = EOVERFLOW;
16 return 0;
17 }
18 return tm;
19 }
20
21 // There is a problem with multi-threaded calls to setenv/getenv.
22 // So we provide this interface for those who don't care about the value of "TZ" set with setenv,
23 // then it will only get the value of "TZ" set by system, no need to call getenv("TZ").
localtime_noenv_r(const time_t * restrict t,struct tm * restrict tm)24 struct tm *localtime_noenv_r(const time_t *restrict t, struct tm *restrict tm)
25 {
26 /* Reject time_t values whose year would overflow int because
27 * __secs_to_zone cannot safely handle them. */
28 if (*t < INT_MIN * 31622400LL || *t > INT_MAX * 31622400LL) {
29 errno = EOVERFLOW;
30 return 0;
31 }
32 __secs_to_zone(*t, 0, &tm->tm_isdst, &tm->__tm_gmtoff, 0, &tm->__tm_zone, TZ_NO_USE_ENV);
33 if (__secs_to_tm((long long)*t + tm->__tm_gmtoff, tm) < 0) {
34 errno = EOVERFLOW;
35 return 0;
36 }
37 return tm;
38 }
39
40 weak_alias(__localtime_r, localtime_r);
41