+AC_ARG_WITH([kevent],
+[ --without-kevent Disables the kevent() I/O backend],
+[],
+[withval="$ac_cv_func_kevent"])
+if test "x$withval" = xyes ; then
+ AC_DEFINE(WITH_IOSET_KEVENT, 1, [Define if using the kevent I/O backend])
+ MODULE_OBJS="$MODULE_OBJS ioset-kevent.\$(OBJEXT)"
+ IOMUXES="$IOMUXES kevent"
+fi
+
+AC_ARG_WITH([win32],
+[ --with-win32 Enables the Win32 I/O backend],
+[],
+[withval="no"])
+if test "x$withval" = xyes ; then
+ AC_DEFINE(WITH_IOSET_WIN32, 1, [Define if using the Win32 I/O backend])
+ MODULE_OBJS="$MODULE_OBJS ioset-win32.\$(OBJEXT)"
+ IOMUXES="$IOMUXES win32"
+fi
+