1#serial 7 2 3# Copyright (C) 2001, 2002, 2003, 2005 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. 7 8dnl From Jim Meyering. 9dnl 10dnl See if gettimeofday clobbers the static buffer that localtime uses 11dnl for its return value. The gettimeofday function from Mac OS X 10.0.4 12dnl (i.e., Darwin 1.3.7) has this problem. 13dnl 14dnl If it does, then arrange to use gettimeofday and localtime only via 15dnl the wrapper functions that work around the problem. 16 17AC_DEFUN([AC_FUNC_GETTIMEOFDAY_CLOBBER], 18[ 19 AC_REQUIRE([AC_HEADER_TIME]) 20 AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer], 21 jm_cv_func_gettimeofday_clobber, 22 [AC_TRY_RUN([ 23#include <stdio.h> 24#include <string.h> 25 26#if TIME_WITH_SYS_TIME 27# include <sys/time.h> 28# include <time.h> 29#else 30# if HAVE_SYS_TIME_H 31# include <sys/time.h> 32# else 33# include <time.h> 34# endif 35#endif 36 37#include <stdlib.h> 38 39int 40main () 41{ 42 time_t t = 0; 43 struct tm *lt; 44 struct tm saved_lt; 45 struct timeval tv; 46 lt = localtime (&t); 47 saved_lt = *lt; 48 gettimeofday (&tv, NULL); 49 if (memcmp (lt, &saved_lt, sizeof (struct tm)) != 0) 50 exit (1); 51 52 exit (0); 53} 54 ], 55 jm_cv_func_gettimeofday_clobber=no, 56 jm_cv_func_gettimeofday_clobber=yes, 57 dnl When crosscompiling, assume it is broken. 58 jm_cv_func_gettimeofday_clobber=yes) 59 ]) 60 if test $jm_cv_func_gettimeofday_clobber = yes; then 61 gl_GETTIMEOFDAY_REPLACE_LOCALTIME 62 63 AC_DEFINE(gettimeofday, rpl_gettimeofday, 64 [Define to rpl_gettimeofday if the replacement function should be used.]) 65 gl_PREREQ_GETTIMEOFDAY 66 fi 67]) 68 69AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [ 70 AC_LIBOBJ(gettimeofday) 71 AC_DEFINE(gmtime, rpl_gmtime, 72 [Define to rpl_gmtime if the replacement function should be used.]) 73 AC_DEFINE(localtime, rpl_localtime, 74 [Define to rpl_localtime if the replacement function should be used.]) 75]) 76 77# Prerequisites of lib/gettimeofday.c. 78AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [ 79 AC_REQUIRE([AC_HEADER_TIME]) 80]) 81