# 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 #include 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) ])