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-rw-r--r--gnulib/m4/gettimeofday.m4101
1 files changed, 101 insertions, 0 deletions
diff --git a/gnulib/m4/gettimeofday.m4 b/gnulib/m4/gettimeofday.m4
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+++ b/gnulib/m4/gettimeofday.m4
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+#serial 11
+
+# Copyright (C) 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering.
+
+AC_DEFUN([gl_FUNC_GETTIMEOFDAY],
+[
+ AC_REQUIRE([AC_C_RESTRICT])
+ AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+ AC_CHECK_FUNCS_ONCE([gettimeofday])
+
+ AC_CACHE_CHECK([for gettimeofday with POSIX signature],
+ [gl_cv_func_gettimeofday_posix_signature],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <sys/time.h>
+ struct timeval c;
+ ]],
+ [[
+ int (*f) (struct timeval *restrict, void *restrict) = gettimeofday;
+ int x = f (&c, 0);
+ return !(x | c.tv_sec | c.tv_usec);
+ ]])],
+ [gl_cv_func_gettimeofday_posix_signature=yes],
+ [gl_cv_func_gettimeofday_posix_signature=no])])
+
+ gl_FUNC_GETTIMEOFDAY_CLOBBER
+
+ if test $gl_cv_func_gettimeofday_posix_signature != yes; then
+ REPLACE_GETTIMEOFDAY=1
+ SYS_TIME_H=sys/time.h
+ if test $gl_cv_func_gettimeofday_clobber != yes; then
+ AC_LIBOBJ(gettimeofday)
+ gl_PREREQ_GETTIMEOFDAY
+ fi
+ fi
+])
+
+
+dnl See if gettimeofday clobbers the static buffer that localtime uses
+dnl for its return value. The gettimeofday function from Mac OS X 10.0.4
+dnl (i.e., Darwin 1.3.7) has this problem.
+dnl
+dnl If it does, then arrange to use gettimeofday and localtime only via
+dnl the wrapper functions that work around the problem.
+
+AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
+[
+ AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+
+ AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
+ [gl_cv_func_gettimeofday_clobber],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <string.h>
+ #include <sys/time.h>
+ #include <time.h>
+ #include <stdlib.h>
+ ]],
+ [[
+ time_t t = 0;
+ struct tm *lt;
+ struct tm saved_lt;
+ struct timeval tv;
+ lt = localtime (&t);
+ saved_lt = *lt;
+ gettimeofday (&tv, NULL);
+ return memcmp (lt, &saved_lt, sizeof (struct tm)) != 0;
+ ]])],
+ [gl_cv_func_gettimeofday_clobber=no],
+ [gl_cv_func_gettimeofday_clobber=yes],
+ dnl When crosscompiling, assume it is broken.
+ [gl_cv_func_gettimeofday_clobber=yes])])
+
+ if test $gl_cv_func_gettimeofday_clobber = yes; then
+ REPLACE_GETTIMEOFDAY=1
+ SYS_TIME_H=sys/time.h
+ gl_GETTIMEOFDAY_REPLACE_LOCALTIME
+ AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], 1,
+ [Define if gettimeofday clobbers the localtime buffer.])
+ fi
+])
+
+AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [
+ AC_LIBOBJ(gettimeofday)
+ gl_PREREQ_GETTIMEOFDAY
+ AC_DEFINE([gmtime], [rpl_gmtime],
+ [Define to rpl_gmtime if the replacement function should be used.])
+ AC_DEFINE([localtime], [rpl_localtime],
+ [Define to rpl_localtime if the replacement function should be used.])
+])
+
+# Prerequisites of lib/gettimeofday.c.
+AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [
+ AC_CHECK_HEADERS([sys/timeb.h])
+ AC_CHECK_FUNCS([_ftime])
+])