1 | /* Convert UTC calendar time to simple time. Like mktime but assumes UTC. |
2 | |
3 | Copyright (C) 1994-2017 Free Software Foundation, Inc. |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #ifdef HAVE_CONFIG_H |
21 | # include <config.h> |
22 | #endif |
23 | |
24 | #ifdef _LIBC |
25 | # include <time.h> |
26 | #else |
27 | # include "timegm.h" |
28 | |
29 | /* Portable standalone applications should supply a "time_r.h" that |
30 | declares a POSIX-compliant gmtime_r, for the benefit of older |
31 | implementations that lack gmtime_r or have a nonstandard one. |
32 | See the gnulib time_r module for one way to implement this. */ |
33 | # include <time_r.h> |
34 | # undef __gmtime_r |
35 | # define __gmtime_r gmtime_r |
36 | time_t __mktime_internal (struct tm *, |
37 | struct tm * (*) (time_t const *, struct tm *), |
38 | time_t *); |
39 | #endif |
40 | |
41 | time_t |
42 | timegm (struct tm *tmp) |
43 | { |
44 | static time_t gmtime_offset; |
45 | tmp->tm_isdst = 0; |
46 | return __mktime_internal (tmp, __gmtime_r, &gmtime_offset); |
47 | } |
48 | |