libvirt/gnulib/m4/poll.m4
Richard W.M. Jones 532759a593 Fri Dec 7 14:27:00 UTC 2007 Richard W.M. Jones <rjones@redhat.com>
* bootstrap, Makefile.am, gnulib/*: Import more gnulib
	  modules for use by MinGW Windows port.
2007-12-07 14:32:35 +00:00

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# poll.m4 serial 7
dnl Copyright (c) 2003, 2005, 2006, 2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_POLL],
[
AC_CHECK_HEADERS(poll.h)
if test "$ac_cv_header_poll_h" = no; then
gl_cv_func_poll=no
else
AC_CHECK_FUNC(poll,
[# Check whether poll() works on special files (like /dev/null) and
# and ttys (like /dev/tty). On MacOS X 10.4.0 and AIX 5.3, it doesn't.
AC_TRY_RUN([
#include <fcntl.h>
#include <poll.h>
int main()
{
struct pollfd ufd;
/* Try /dev/null for reading. */
ufd.fd = open ("/dev/null", O_RDONLY);
if (ufd.fd < 0)
/* If /dev/null does not exist, it's not MacOS X nor AIX. */
return 0;
ufd.events = POLLIN;
ufd.revents = 0;
if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLIN))
return 1;
/* Try /dev/null for writing. */
ufd.fd = open ("/dev/null", O_WRONLY);
if (ufd.fd < 0)
/* If /dev/null does not exist, it's not MacOS X nor AIX. */
return 0;
ufd.events = POLLOUT;
ufd.revents = 0;
if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLOUT))
return 1;
/* Trying /dev/tty may be too environment dependent. */
return 0;
}],
[gl_cv_func_poll=yes],
[gl_cv_func_poll=no],
[# When cross-compiling, assume that poll() works everywhere except on
# MacOS X or AIX, regardless of its version.
AC_EGREP_CPP([MacOSX], [
#if (defined(__APPLE__) && defined(__MACH__)) || defined(_AIX)
This is MacOSX or AIX
#endif
], [gl_cv_func_poll=no], [gl_cv_func_poll=yes])])])
fi
if test $gl_cv_func_poll = yes; then
AC_DEFINE([HAVE_POLL], 1,
[Define to 1 if you have the 'poll' function and it works.])
POLL_H=
else
AC_LIBOBJ(poll)
AC_DEFINE(poll, rpl_poll,
[Define to poll if the replacement function should be used.])
gl_PREREQ_POLL
POLL_H=poll.h
fi
AC_SUBST([POLL_H])
])
# Prerequisites of lib/poll.c.
AC_DEFUN([gl_PREREQ_POLL],
[
AC_CHECK_HEADERS_ONCE(sys/ioctl.h sys/filio.h)
])