3 # Copyright (C) 2001-2003, 2005, 2007, 2009-2011 Free Software Foundation, Inc.
4 # This file is free software; the Free Software Foundation
5 # gives unlimited permission to copy and/or distribute it,
6 # with or without modifications, as long as this notice is preserved.
10 AC_DEFUN([gl_FUNC_GETTIMEOFDAY],
12 AC_REQUIRE([AC_C_RESTRICT])
13 AC_REQUIRE([gl_HEADER_SYS_TIME_H])
14 AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
15 AC_CHECK_FUNCS_ONCE([gettimeofday])
17 gl_gettimeofday_timezone=void
18 if test $ac_cv_func_gettimeofday != yes; then
21 gl_FUNC_GETTIMEOFDAY_CLOBBER
22 AC_CACHE_CHECK([for gettimeofday with POSIX signature],
23 [gl_cv_func_gettimeofday_posix_signature],
26 [[#include <sys/time.h>
28 int gettimeofday (struct timeval *restrict, void *restrict);
30 [[/* glibc uses struct timezone * rather than the POSIX void *
31 if _GNU_SOURCE is defined. However, since the only portable
32 use of gettimeofday uses NULL as the second parameter, and
33 since the glibc definition is actually more typesafe, it is
34 not worth wrapping this to get a compliant signature. */
35 int (*f) (struct timeval *restrict, void *restrict)
38 return !(x | c.tv_sec | c.tv_usec);
40 [gl_cv_func_gettimeofday_posix_signature=yes],
43 [[#include <sys/time.h>
44 int gettimeofday (struct timeval *restrict, struct timezone *restrict);
46 [gl_cv_func_gettimeofday_posix_signature=almost],
47 [gl_cv_func_gettimeofday_posix_signature=no])])])
48 if test $gl_cv_func_gettimeofday_posix_signature = almost; then
49 gl_gettimeofday_timezone='struct timezone'
50 elif test $gl_cv_func_gettimeofday_posix_signature != yes; then
51 REPLACE_GETTIMEOFDAY=1
53 m4_ifdef([gl_FUNC_TZSET_CLOBBER], [
55 if test $gl_cv_func_tzset_clobber = yes; then
56 REPLACE_GETTIMEOFDAY=1
57 gl_GETTIMEOFDAY_REPLACE_LOCALTIME
58 AC_DEFINE([tzset], [rpl_tzset],
59 [Define to rpl_tzset if the wrapper function should be used.])
60 AC_DEFINE([TZSET_CLOBBERS_LOCALTIME], [1],
61 [Define if tzset clobbers localtime's static buffer.])
65 AC_DEFINE_UNQUOTED([GETTIMEOFDAY_TIMEZONE], [$gl_gettimeofday_timezone],
66 [Define this to 'void' or 'struct timezone' to match the system's
67 declaration of the second argument to gettimeofday.])
71 dnl See if gettimeofday clobbers the static buffer that localtime uses
72 dnl for its return value. The gettimeofday function from Mac OS X 10.0.4
73 dnl (i.e., Darwin 1.3.7) has this problem.
75 dnl If it does, then arrange to use gettimeofday and localtime only via
76 dnl the wrapper functions that work around the problem.
78 AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
80 AC_REQUIRE([gl_HEADER_SYS_TIME_H])
82 AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
83 [gl_cv_func_gettimeofday_clobber],
98 gettimeofday (&tv, NULL);
99 return memcmp (lt, &saved_lt, sizeof (struct tm)) != 0;
101 [gl_cv_func_gettimeofday_clobber=no],
102 [gl_cv_func_gettimeofday_clobber=yes],
103 dnl When crosscompiling, assume it is broken.
104 [gl_cv_func_gettimeofday_clobber=yes])])
106 if test $gl_cv_func_gettimeofday_clobber = yes; then
107 REPLACE_GETTIMEOFDAY=1
108 gl_GETTIMEOFDAY_REPLACE_LOCALTIME
109 AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
110 [Define if gettimeofday clobbers the localtime buffer.])
114 AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [
115 AC_DEFINE([gmtime], [rpl_gmtime],
116 [Define to rpl_gmtime if the replacement function should be used.])
117 AC_DEFINE([localtime], [rpl_localtime],
118 [Define to rpl_localtime if the replacement function should be used.])
121 # Prerequisites of lib/gettimeofday.c.
122 AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [
123 AC_CHECK_HEADERS([sys/timeb.h])
124 AC_CHECK_FUNCS([_ftime])