Update gnulib files.
[gnutls:gnutls.git] / gl / m4 / select.m4
1 # select.m4 serial 3
2 dnl Copyright (C) 2009, 2010 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
6
7 AC_DEFUN([gl_FUNC_SELECT],
8 [
9   AC_REQUIRE([gl_HEADER_SYS_SELECT])
10   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
11   AC_REQUIRE([gl_SOCKETS])
12   if test "$ac_cv_header_winsock2_h" = yes; then
13     AC_LIBOBJ([select])
14   else
15     dnl On Interix 3.5, select(0, NULL, NULL, NULL, timeout) fails with error
16     dnl EFAULT.
17     AC_CHECK_HEADERS_ONCE([sys/select.h])
18     AC_CACHE_CHECK([whether select supports a 0 argument],
19       [gl_cv_func_select_supports0],
20       [
21         AC_RUN_IFELSE([AC_LANG_SOURCE([[
22 #include <sys/types.h>
23 #include <sys/time.h>
24 #if HAVE_SYS_SELECT_H
25 #include <sys/select.h>
26 #endif
27 int main ()
28 {
29   struct timeval timeout;
30   timeout.tv_sec = 0;
31   timeout.tv_usec = 5;
32   return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0;
33 }]])], [gl_cv_func_select_supports0=yes], [gl_cv_func_select_supports0=no],
34           [
35 changequote(,)dnl
36            case "$host_os" in
37                        # Guess no on Interix.
38              interix*) gl_cv_func_select_supports0="guessing no";;
39                        # Guess yes otherwise.
40              *)        gl_cv_func_select_supports0="guessing yes";;
41            esac
42 changequote([,])dnl
43           ])
44       ])
45     case "$gl_cv_func_select_supports0" in
46       *yes) ;;
47       *)
48         REPLACE_SELECT=1
49         AC_LIBOBJ([select])
50         ;;
51     esac
52   fi
53 ])