X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=m4%2Fpoll.m4;h=e489df7a00899fb2bdc38f26c19993cf228c96c3;hb=9c5e07d317077af2cfc3f0816bcc8cab03dd4260;hp=d56c9ffcb83bd94d1bb4e943689ed4d7b10c7bf0;hpb=44d7c1c1f004fa9bfb8ec3948de2671a7958cf5b;p=gnulib.git

diff --git a/m4/poll.m4 b/m4/poll.m4
index d56c9ffcb..e489df7a0 100644
--- a/m4/poll.m4
+++ b/m4/poll.m4
@@ -1,28 +1,77 @@
-# poll.m4 serial 3
-dnl Copyright (c) 2003 Free Software Foundation, Inc.
+# poll.m4 serial 14
+dnl Copyright (c) 2003, 2005-2007, 2009-2011 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)
+  AC_REQUIRE([gl_POLL_H])
   if test "$ac_cv_header_poll_h" = no; then
-    POLL_H=poll.h
+    ac_cv_func_poll=no
+    gl_cv_func_poll=no
   else
-    POLL_H=
+    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_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <fcntl.h>
+#include <poll.h>
+         int main()
+         {
+           int result = 0;
+           struct pollfd ufd;
+           /* Try /dev/null for reading.  */
+           ufd.fd = open ("/dev/null", O_RDONLY);
+           /* If /dev/null does not exist, it's not MacOS X nor AIX. */
+           if (ufd.fd >= 0)
+             {
+               ufd.events = POLLIN;
+               ufd.revents = 0;
+               if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLIN))
+                 result |= 1;
+             }
+           /* Try /dev/null for writing.  */
+           ufd.fd = open ("/dev/null", O_WRONLY);
+           /* If /dev/null does not exist, it's not MacOS X nor AIX. */
+           if (ufd.fd >= 0)
+             {
+               ufd.events = POLLOUT;
+               ufd.revents = 0;
+               if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLOUT))
+                 result |= 2;
+             }
+           /* Trying /dev/tty may be too environment dependent.  */
+           return result;
+         }]])],
+         [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
-  AC_SUBST([POLL_H])
-
-  AC_REPLACE_FUNCS(poll)
-  if test $ac_cv_func_poll = no; then
-    gl_PREREQ_POLL
+  if test $gl_cv_func_poll != yes; then
+    AC_CHECK_FUNC([poll], [ac_cv_func_poll=yes], [ac_cv_func_poll=no])
+    if test $ac_cv_func_poll = no; then
+      HAVE_POLL=0
+    else
+      REPLACE_POLL=1
+    fi
+  fi
+  if test $HAVE_POLL = 0 || test $REPLACE_POLL = 1; then
+    :
+  else
+    AC_DEFINE([HAVE_POLL], [1],
+      [Define to 1 if you have the 'poll' function and it works.])
   fi
 ])
 
 # Prerequisites of lib/poll.c.
 AC_DEFUN([gl_PREREQ_POLL],
 [
-  AC_REQUIRE([AC_HEADER_TIME])
-  AC_CHECK_HEADERS_ONCE(sys/time.h)
+  AC_CHECK_HEADERS_ONCE([sys/ioctl.h sys/filio.h])
 ])