1# serial 21 2 3# Copyright (C) 2001-2003, 2005, 2007, 2009-2014 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. 9 10AC_DEFUN([gl_FUNC_GETTIMEOFDAY], 11[ 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]) 16 17 gl_gettimeofday_timezone=void 18 if test $ac_cv_func_gettimeofday != yes; then 19 HAVE_GETTIMEOFDAY=0 20 else 21 gl_FUNC_GETTIMEOFDAY_CLOBBER 22 AC_CACHE_CHECK([for gettimeofday with POSIX signature], 23 [gl_cv_func_gettimeofday_posix_signature], 24 [AC_COMPILE_IFELSE( 25 [AC_LANG_PROGRAM( 26 [[#include <sys/time.h> 27 struct timeval c; 28 int gettimeofday (struct timeval *restrict, void *restrict); 29 ]], 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) 36 = gettimeofday; 37 int x = f (&c, 0); 38 return !(x | c.tv_sec | c.tv_usec); 39 ]])], 40 [gl_cv_func_gettimeofday_posix_signature=yes], 41 [AC_COMPILE_IFELSE( 42 [AC_LANG_PROGRAM( 43 [[#include <sys/time.h> 44int gettimeofday (struct timeval *restrict, struct timezone *restrict); 45 ]])], 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 52 fi 53 dnl If we override 'struct timeval', we also have to override gettimeofday. 54 if test $REPLACE_STRUCT_TIMEVAL = 1; then 55 REPLACE_GETTIMEOFDAY=1 56 fi 57 m4_ifdef([gl_FUNC_TZSET_CLOBBER], [ 58 gl_FUNC_TZSET_CLOBBER 59 case "$gl_cv_func_tzset_clobber" in 60 *yes) 61 REPLACE_GETTIMEOFDAY=1 62 gl_GETTIMEOFDAY_REPLACE_LOCALTIME 63 AC_DEFINE([tzset], [rpl_tzset], 64 [Define to rpl_tzset if the wrapper function should be used.]) 65 AC_DEFINE([TZSET_CLOBBERS_LOCALTIME], [1], 66 [Define if tzset clobbers localtime's static buffer.]) 67 ;; 68 esac 69 ]) 70 fi 71 AC_DEFINE_UNQUOTED([GETTIMEOFDAY_TIMEZONE], [$gl_gettimeofday_timezone], 72 [Define this to 'void' or 'struct timezone' to match the system's 73 declaration of the second argument to gettimeofday.]) 74]) 75 76 77dnl See if gettimeofday clobbers the static buffer that localtime uses 78dnl for its return value. The gettimeofday function from Mac OS X 10.0.4 79dnl (i.e., Darwin 1.3.7) has this problem. 80dnl 81dnl If it does, then arrange to use gettimeofday and localtime only via 82dnl the wrapper functions that work around the problem. 83 84AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER], 85[ 86 AC_REQUIRE([gl_HEADER_SYS_TIME_H]) 87 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 88 89 AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer], 90 [gl_cv_func_gettimeofday_clobber], 91 [AC_RUN_IFELSE( 92 [AC_LANG_PROGRAM( 93 [[#include <string.h> 94 #include <sys/time.h> 95 #include <time.h> 96 #include <stdlib.h> 97 ]], 98 [[ 99 time_t t = 0; 100 struct tm *lt; 101 struct tm saved_lt; 102 struct timeval tv; 103 lt = localtime (&t); 104 saved_lt = *lt; 105 gettimeofday (&tv, NULL); 106 return memcmp (lt, &saved_lt, sizeof (struct tm)) != 0; 107 ]])], 108 [gl_cv_func_gettimeofday_clobber=no], 109 [gl_cv_func_gettimeofday_clobber=yes], 110 [# When cross-compiling: 111 case "$host_os" in 112 # Guess all is fine on glibc systems. 113 *-gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;; 114 # If we don't know, assume the worst. 115 *) gl_cv_func_gettimeofday_clobber="guessing yes" ;; 116 esac 117 ])]) 118 119 case "$gl_cv_func_gettimeofday_clobber" in 120 *yes) 121 REPLACE_GETTIMEOFDAY=1 122 gl_GETTIMEOFDAY_REPLACE_LOCALTIME 123 AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1], 124 [Define if gettimeofday clobbers the localtime buffer.]) 125 ;; 126 esac 127]) 128 129AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [ 130 REPLACE_GMTIME=1 131 REPLACE_LOCALTIME=1 132]) 133 134# Prerequisites of lib/gettimeofday.c. 135AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [ 136 AC_CHECK_HEADERS([sys/timeb.h]) 137 AC_CHECK_FUNCS([_ftime]) 138]) 139