X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fpoll.m4;h=aed57a050325275a08c3a1233fe6dfda5583aad5;hb=4ef30f6cf2439380afe78dee027e322fcbf8e756;hp=a23f504f135e80d7bfb388931fc2dbc1ae4f823e;hpb=8577bd357660986eaceacf6f8b0fd6870d2098b7;p=gnulib.git

diff --git a/m4/poll.m4 b/m4/poll.m4
index a23f504f1..aed57a050 100644
--- a/m4/poll.m4
+++ b/m4/poll.m4
@@ -1,20 +1,65 @@
-# poll.m4 serial 1
-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 4
+dnl Copyright (c) 2003, 2005 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 x$ac_cv_header_poll_h = xno; then
-    AC_CONFIG_LINKS([lib/poll.h:lib/poll_.h])
+  if test "$ac_cv_header_poll_h" = no; then
+    POLL_H=poll.h
+  else
+    POLL_H=
   fi
+  AC_SUBST([POLL_H])
 
-  AC_REPLACE_FUNCS(poll)
-  if test $ac_cv_func_poll = no; then
+  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, 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. */
+           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. */
+           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, regardless of its version.
+        AC_EGREP_CPP([MacOSX], [
+#if defined(__APPLE__) && defined(__MACH__)
+This is MacOSX
+#endif
+], [gl_cv_func_poll=no], [gl_cv_func_poll=yes])])])
+  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.])
+  fi
+
+  if test $gl_cv_func_poll = no; then
+    AC_LIBOBJ(poll)
+    AC_DEFINE(poll, rpl_poll,
+      [Define to poll if the replacement function should be used.])
     gl_PREREQ_POLL
   fi
 ])