X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fpoll.m4;h=bb610dadd043a1a2e07b2a83c1bb34d871328cec;hb=9dcc0e05407833a59b84cb6b32460242ddc6ff98;hp=5bfc33c6f122c5b15f0c1129540c3fd6467230c3;hpb=7e4a3ea582fe5a1224685a0bc852e22f91f18abc;p=gnulib.git

diff --git a/m4/poll.m4 b/m4/poll.m4
index 5bfc33c6f..bb610dadd 100644
--- a/m4/poll.m4
+++ b/m4/poll.m4
@@ -1,30 +1,71 @@
-# poll.m4 serial 2
-dnl Copyright (c) 2003 Free Software Foundation, Inc.
-dnl This file is free software, distributed under the terms of the GNU
-dnl General Public License.  As a special exception to the GNU General
-dnl Public License, this file may be distributed as part of a program
-dnl that contains a configuration script generated by Autoconf, under
-dnl the same distribution terms as the rest of the program.
+# 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
-    POLL_H=poll.h
+    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_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
-  AC_SUBST([POLL_H])
-
-  AC_REPLACE_FUNCS(poll)
-  if test $ac_cv_func_poll = no; then
+  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_REQUIRE([AC_HEADER_TIME])
-  AC_CHECK_HEADERS_ONCE(sys/time.h)
+  AC_CHECK_HEADERS_ONCE(sys/ioctl.h sys/filio.h)
 ])