manual: fix addmntent's MT-Safety race annotation
[glibc.git] / time / timegm.c
blob212bfa732799d7a6c77a09d8bb9a381d91e68a2e
1 /* Convert UTC calendar time to simple time. Like mktime but assumes UTC.
3 Copyright (C) 1994-2014 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
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.
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.
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/>. */
20 #ifdef HAVE_CONFIG_H
21 # include <config.h>
22 #endif
24 #ifdef _LIBC
25 # include <time.h>
26 #else
27 # include "timegm.h"
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
41 time_t
42 timegm (struct tm *tmp)
44 static time_t gmtime_offset;
45 tmp->tm_isdst = 0;
46 return __mktime_internal (tmp, __gmtime_r, &gmtime_offset);