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
36time_t __mktime_internal (struct tm *,
37 struct tm * (*) (time_t const *, struct tm *),
38 time_t *);
39#endif
40
41time_t
42timegm (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