Setting tag sliver-openvswitch-2.2.90-1
[sliver-openvswitch.git] / m4 / openvswitch.m4
index c5f0742..fa741f6 100644 (file)
@@ -1,6 +1,6 @@
 # -*- autoconf -*-
 
-# Copyright (c) 2008, 2009, 2010 Nicira Networks.
+# Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -19,10 +19,10 @@ AC_DEFUN([OVS_CHECK_COVERAGE],
   [AC_REQUIRE([AC_PROG_CC])
    AC_ARG_ENABLE(
      [coverage],
-     [AC_HELP_STRING([--enable-coverage], 
+     [AC_HELP_STRING([--enable-coverage],
                      [Enable gcov coverage tool.])],
      [case "${enableval}" in
-        (lcov|yes) coverage=true ;;
+        (yes) coverage=true ;;
         (no)  coverage=false ;;
         (*) AC_MSG_ERROR([bad value ${enableval} for --enable-coverage]) ;;
       esac],
@@ -36,7 +36,7 @@ dnl Checks for --enable-ndebug and defines NDEBUG if it is specified.
 AC_DEFUN([OVS_CHECK_NDEBUG],
   [AC_ARG_ENABLE(
      [ndebug],
-     [AC_HELP_STRING([--enable-ndebug], 
+     [AC_HELP_STRING([--enable-ndebug],
                      [Disable debugging features for max performance])],
      [case "${enableval}" in
         (yes) ndebug=true ;;
@@ -46,13 +46,56 @@ AC_DEFUN([OVS_CHECK_NDEBUG],
      [ndebug=false])
    AM_CONDITIONAL([NDEBUG], [test x$ndebug = xtrue])])
 
+dnl Checks for ESX.
+AC_DEFUN([OVS_CHECK_ESX],
+  [AC_CHECK_HEADER([vmware.h],
+                   [ESX=yes],
+                   [ESX=no])
+   AM_CONDITIONAL([ESX], [test "$ESX" = yes])
+   if test "$ESX" = yes; then
+      AC_DEFINE([ESX], [1], [Define to 1 if building on ESX.])
+   fi])
+
+dnl Checks for WINDOWS.
+AC_DEFUN([OVS_CHECK_WIN32],
+  [AC_CHECK_HEADER([windows.h],
+                   [WIN32=yes],
+                   [WIN32=no])
+   AM_CONDITIONAL([WIN32], [test "$WIN32" = yes])
+   if test "$WIN32" = yes; then
+      AC_ARG_WITH([pthread],
+         [AS_HELP_STRING([--with-pthread=DIR],
+            [root of the pthread-win32 directory])],
+         [
+            case "$withval" in
+            "" | y | ye | yes | n | no)
+            AC_MSG_ERROR([Invalid --with-pthread value])
+              ;;
+            *)
+            PTHREAD_INCLUDES="-I$withval/include"
+            PTHREAD_LDFLAGS="-L$withval/lib/x86"
+            PTHREAD_LIBS="-lpthreadVC2"
+            AC_SUBST([PTHREAD_INCLUDES])
+            AC_SUBST([PTHREAD_LDFLAGS])
+            AC_SUBST([PTHREAD_LIBS])
+              ;;
+            esac
+         ], [
+            AC_MSG_ERROR([pthread directory not specified])
+         ]
+      )
+      AC_DEFINE([WIN32], [1], [Define to 1 if building on WIN32.])
+      AH_BOTTOM([#ifdef WIN32
+#include "include/windows/windefs.h"
+#endif])
+   fi])
+
 dnl Checks for Netlink support.
 AC_DEFUN([OVS_CHECK_NETLINK],
   [AC_CHECK_HEADER([linux/netlink.h],
                    [HAVE_NETLINK=yes],
                    [HAVE_NETLINK=no],
                    [#include <sys/socket.h>
-   #include <linux/types.h>
    ])
    AM_CONDITIONAL([HAVE_NETLINK], [test "$HAVE_NETLINK" = yes])
    if test "$HAVE_NETLINK" = yes; then
@@ -73,20 +116,18 @@ AC_DEFUN([OVS_CHECK_OPENSSL],
      [ssl=check])
 
    if test "$ssl" != false; then
-       dnl Make sure that pkg-config is installed.
-       m4_pattern_forbid([PKG_CHECK_MODULES])
-       PKG_CHECK_MODULES([SSL], [libssl], 
+       AX_CHECK_OPENSSL(
          [HAVE_OPENSSL=yes],
          [HAVE_OPENSSL=no
           if test "$ssl" = check; then
-            AC_MSG_WARN([Cannot find libssl:
+            AC_MSG_WARN([Cannot find openssl:
 
 $SSL_PKG_ERRORS
 
 OpenFlow connections over SSL will not be supported.
 (You may use --disable-ssl to suppress this warning.)])
           else
-            AC_MSG_ERROR([Cannot find libssl (use --disable-ssl to configure without SSL support)])
+            AC_MSG_ERROR([Cannot find openssl (use --disable-ssl to configure without SSL support)])
           fi])
    else
        HAVE_OPENSSL=no
@@ -100,23 +141,23 @@ OpenFlow connections over SSL will not be supported.
 dnl Checks for libraries needed by lib/socket-util.c.
 AC_DEFUN([OVS_CHECK_SOCKET_LIBS],
   [AC_CHECK_LIB([socket], [connect])
-   AC_SEARCH_LIBS([gethostbyname], [resolv], [RESOLVER_LIBS=-lresolv])])
+   AC_SEARCH_LIBS([gethostbyname], [resolv])])
 
 dnl Checks for the directory in which to store the PKI.
 AC_DEFUN([OVS_CHECK_PKIDIR],
   [AC_ARG_WITH(
-     [pkidir], 
-     AC_HELP_STRING([--with-pkidir=DIR], 
-                    [PKI hierarchy directory [[DATADIR/openvswitch/pki]]]),
+     [pkidir],
+     AC_HELP_STRING([--with-pkidir=DIR],
+                    [PKI hierarchy directory [[LOCALSTATEDIR/lib/openvswitch/pki]]]),
      [PKIDIR=$withval],
-     [PKIDIR='${pkgdatadir}/pki'])
+     [PKIDIR='${localstatedir}/lib/openvswitch/pki'])
    AC_SUBST([PKIDIR])])
 
 dnl Checks for the directory in which to store pidfiles.
 AC_DEFUN([OVS_CHECK_RUNDIR],
   [AC_ARG_WITH(
-     [rundir], 
-     AC_HELP_STRING([--with-rundir=DIR], 
+     [rundir],
+     AC_HELP_STRING([--with-rundir=DIR],
                     [directory used for pidfiles
                     [[LOCALSTATEDIR/run/openvswitch]]]),
      [RUNDIR=$withval],
@@ -126,13 +167,29 @@ AC_DEFUN([OVS_CHECK_RUNDIR],
 dnl Checks for the directory in which to store logs.
 AC_DEFUN([OVS_CHECK_LOGDIR],
   [AC_ARG_WITH(
-     [logdir], 
-     AC_HELP_STRING([--with-logdir=DIR], 
+     [logdir],
+     AC_HELP_STRING([--with-logdir=DIR],
                     [directory used for logs [[LOCALSTATEDIR/log/PACKAGE]]]),
      [LOGDIR=$withval],
      [LOGDIR='${localstatedir}/log/${PACKAGE}'])
    AC_SUBST([LOGDIR])])
 
+dnl Checks for the directory in which to store the Open vSwitch database.
+AC_DEFUN([OVS_CHECK_DBDIR],
+  [AC_ARG_WITH(
+     [dbdir],
+     AC_HELP_STRING([--with-dbdir=DIR],
+                    [directory used for conf.db [[SYSCONFDIR/PACKAGE]]]),
+     [DBDIR=$withval],
+     [DBDIR='${sysconfdir}/${PACKAGE}'])
+   AC_SUBST([DBDIR])])
+
+dnl Defines HAVE_BACKTRACE if backtrace() is found.
+AC_DEFUN([OVS_CHECK_BACKTRACE],
+  [AC_SEARCH_LIBS([backtrace], [execinfo ubacktrace],
+                  [AC_DEFINE([HAVE_BACKTRACE], [1],
+                             [Define to 1 if you have backtrace(3).])])])
+
 dnl Checks for __malloc_hook, etc., supported by glibc.
 AC_DEFUN([OVS_CHECK_MALLOC_HOOKS],
   [AC_CACHE_CHECK(
@@ -141,20 +198,20 @@ AC_DEFUN([OVS_CHECK_MALLOC_HOOKS],
     [AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM(
          [#include <malloc.h>
-         ], 
+         ],
          [(void) __malloc_hook;
           (void) __realloc_hook;
           (void) __free_hook;])],
       [ovs_cv_malloc_hooks=yes],
       [ovs_cv_malloc_hooks=no])])
    if test $ovs_cv_malloc_hooks = yes; then
-     AC_DEFINE([HAVE_MALLOC_HOOKS], [1], 
+     AC_DEFINE([HAVE_MALLOC_HOOKS], [1],
                [Define to 1 if you have __malloc_hook, __realloc_hook, and
                 __free_hook in <malloc.h>.])
    fi])
 
 dnl Checks for valgrind/valgrind.h.
-AC_DEFUN([OVS_CHECK_VALGRIND], 
+AC_DEFUN([OVS_CHECK_VALGRIND],
   [AC_CHECK_HEADERS([valgrind/valgrind.h])])
 
 dnl Checks for Python 2.x, x >= 4.
@@ -171,7 +228,7 @@ AC_DEFUN([OVS_CHECK_PYTHON],
           for dir in $PATH; do
             IFS=$ovs_save_IFS
             test -z "$dir" && dir=.
-            if test -x $dir/$binary && $dir/$binary -c 'import sys
+            if test -x "$dir"/"$binary" && "$dir"/"$binary" -c 'import sys
 if sys.hexversion >= 0x02040000 and sys.hexversion < 0x03000000:
     sys.exit(0)
 else:
@@ -202,36 +259,8 @@ AC_DEFUN([OVS_CHECK_DOT],
        ovs_cv_dot=yes
      else
        ovs_cv_dot=no
-     fi])])
-
-dnl Check whether to build E-R diagrams.
-AC_DEFUN([OVS_CHECK_ER_DIAGRAMS],
-  [AC_REQUIRE([OVS_CHECK_DOT])
-   AC_REQUIRE([OVS_CHECK_PYTHON])
-   AC_CACHE_CHECK(
-    [whether to build E-R diagrams for database],
-    [ovs_cv_er_diagrams],
-    [if test $ovs_cv_dot != no && test $ovs_cv_python != no; then
-       ovs_cv_er_diagrams=yes
-     else
-       ovs_cv_er_diagrams=no
-     fi])
-   AM_CONDITIONAL([BUILD_ER_DIAGRAMS], [test $ovs_cv_er_diagrams = yes])])
-
-dnl Checks for pyuic4.
-AC_DEFUN([OVS_CHECK_PYUIC4],
-  [AC_CACHE_CHECK(
-    [for pyuic4],
-    [ovs_cv_pyuic4],
-    [if (pyuic4 --version) >/dev/null 2>&1; then
-       ovs_cv_pyuic4=pyuic4
-     else
-       ovs_cv_pyuic4=no
      fi])
-   AM_MISSING_PROG([PYUIC4], [pyuic4])
-   if test $ovs_cv_pyuic4 != no; then
-     PYUIC4=$ovs_cv_pyuic4
-   fi])
+   AM_CONDITIONAL([HAVE_DOT], [test "$ovs_cv_dot" = yes])])
 
 dnl Checks whether $PYTHON supports the module given as $1
 AC_DEFUN([OVS_CHECK_PYTHON_MODULE],
@@ -251,101 +280,170 @@ sys.exit(0)' >&AS_MESSAGE_LOG_FD 2>&1; then
         fi
       fi])])
 
-dnl Checks for Python modules needed by ovsdbmonitor.
-AC_DEFUN([OVS_CHECK_OVSDBMONITOR],
-  [OVS_CHECK_PYTHON_MODULE([PySide.QtCore])
-   OVS_CHECK_PYTHON_MODULE([PyQt4.QtCore])
-   OVS_CHECK_PYTHON_MODULE([twisted.conch.ssh])
-   OVS_CHECK_PYTHON_MODULE([twisted.internet])
-   OVS_CHECK_PYTHON_MODULE([twisted.application])
-   OVS_CHECK_PYTHON_MODULE([json])
-   OVS_CHECK_PYTHON_MODULE([zope.interface])
-   if (test $ovs_cv_py_PySide_QtCore = yes \
-       || test $ovs_cv_py_PyQt4_QtCore = yes) \
-      && test $ovs_cv_py_twisted_conch_ssh = yes \
-      && test $ovs_cv_py_twisted_internet = yes \
-      && test $ovs_cv_py_twisted_application = yes \
-      && test $ovs_cv_py_json = yes \
-      && test $ovs_cv_py_zope_interface = yes; then
-     BUILD_OVSDBMONITOR=yes
+dnl Checks for missing python modules at build time
+AC_DEFUN([OVS_CHECK_PYTHON_COMPAT],
+  [OVS_CHECK_PYTHON_MODULE([uuid])
+   if test $ovs_cv_py_uuid = yes; then
+     INCLUDE_PYTHON_COMPAT=no
    else
-     BUILD_OVSDBMONITOR=no
+     INCLUDE_PYTHON_COMPAT=yes
    fi
-   AC_MSG_CHECKING([whether to build ovsdbmonitor])
-   AC_MSG_RESULT([$BUILD_OVSDBMONITOR])
-   AM_CONDITIONAL([BUILD_OVSDBMONITOR], [test $BUILD_OVSDBMONITOR = yes])])
+   AC_MSG_CHECKING([whether to add python/compat to PYTHONPATH])
+   AC_MSG_RESULT([$INCLUDE_PYTHON_COMPAT])
+   AM_CONDITIONAL([INCLUDE_PYTHON_COMPAT], [test $INCLUDE_PYTHON_COMPAT = yes])])
 
-# OVS_LINK2_IFELSE(SOURCE1, SOURCE2, [ACTION-IF-TRUE], [ACTION-IF-FALSE])
-# -------------------------------------------------------------
-# Based on AC_LINK_IFELSE, but tries to link both SOURCE1 and SOURCE2
-# into a program.
-#
-# This macro is borrowed from acinclude.m4 in GNU PSPP, which has the
-# following license:
-#
-#     Copyright (C) 2005, 2006, 2007, 2009 Free Software Foundation, Inc.
-#     This file is free software; the Free Software Foundation
-#     gives unlimited permission to copy and/or distribute it,
-#     with or without modifications, as long as this notice is preserved.
-#
-m4_define([OVS_LINK2_IFELSE],
-[m4_ifvaln([$1], [AC_LANG_CONFTEST([$1])])dnl
-mv conftest.$ac_ext conftest1.$ac_ext
-m4_ifvaln([$2], [AC_LANG_CONFTEST([$2])])dnl
-mv conftest.$ac_ext conftest2.$ac_ext
-rm -f conftest1.$ac_objext conftest2.$ac_objext conftest$ac_exeext
-ovs_link2='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest1.$ac_ext conftest2.$ac_ext $LIBS >&5'
-AS_IF([_AC_DO_STDERR($ovs_link2) && {
-        test -z "$ac_[]_AC_LANG_ABBREV[]_werror_flag" ||
-        test ! -s conftest.err
-       } && test -s conftest$ac_exeext && {
-        test "$cross_compiling" = yes ||
-        AS_TEST_X([conftest$ac_exeext])
-       }],
-      [$3],
-      [echo "$as_me: failed source file 1 of 2 was:" >&5
-sed 's/^/| /' conftest1.$ac_ext >&5
-echo "$as_me: failed source file 2 of 2 was:" >&5
-sed 's/^/| /' conftest2.$ac_ext >&5
-       $4])
-dnl Delete also the IPA/IPO (Inter Procedural Analysis/Optimization)
-dnl information created by the PGI compiler (conftest_ipa8_conftest.oo),
-dnl as it would interfere with the next link command.
-rm -rf conftest.dSYM conftest1.dSYM conftest2.dSYM
-rm -f core conftest.err conftest1.err conftest2.err
-rm -f conftest1.$ac_objext conftest2.$ac_objext conftest*_ipa8_conftest*.oo
-rm -f conftest$ac_exeext
-rm -f m4_ifval([$1], [conftest1.$ac_ext]) m4_ifval([$2], [conftest1.$ac_ext])[]dnl
-])# OVS_LINK2_IFELSE
+dnl Checks for groff.
+AC_DEFUN([OVS_CHECK_GROFF],
+  [AC_CACHE_CHECK(
+    [for groff],
+    [ovs_cv_groff],
+    [if (groff -v) >/dev/null 2>&1; then
+       ovs_cv_groff=yes
+     else
+       ovs_cv_groff=no
+     fi])
+   AM_CONDITIONAL([HAVE_GROFF], [test "$ovs_cv_groff" = yes])])
 
-dnl Defines USE_LINKER_SECTIONS to 1 if the compiler supports putting
-dnl variables in sections with user-defined names and the linker
-dnl automatically defines __start_SECNAME and __stop_SECNAME symbols
-dnl that designate the start and end of the sections.
-AC_DEFUN([OVS_CHECK_LINKER_SECTIONS],
+dnl Checks for thread-local storage support.
+dnl
+dnl Checks whether the compiler and linker support the C11
+dnl thread_local macro from <threads.h>, and if so defines
+dnl HAVE_THREAD_LOCAL.  If not, checks whether the compiler and linker
+dnl support the GCC __thread extension, and if so defines
+dnl HAVE___THREAD.
+AC_DEFUN([OVS_CHECK_TLS],
   [AC_CACHE_CHECK(
-    [for user-defined linker section support],
-    [ovs_cv_use_linker_sections],
-    [OVS_LINK2_IFELSE(
-      [AC_LANG_SOURCE(
-        [int a __attribute__((__section__("mysection"))) = 1;
-         int b __attribute__((__section__("mysection"))) = 2;
-         int c __attribute__((__section__("mysection"))) = 3;])],
-      [AC_LANG_PROGRAM(
-        [#include <stdio.h>
-         extern int __start_mysection;
-         extern int __stop_mysection;],
-        [int n_ints = &__stop_mysection - &__start_mysection;
-         int *i;
-         for (i = &__start_mysection; i < &__start_mysection + n_ints; i++) {
-             printf("%d\n", *i);
-         }])],
-      [ovs_cv_use_linker_sections=yes],
-      [ovs_cv_use_linker_sections=no])])
-   if test $ovs_cv_use_linker_sections = yes; then
-     AC_DEFINE([USE_LINKER_SECTIONS], [1],
-               [Define to 1 if the compiler support putting variables
-                into sections with user-defined names and the linker
-                automatically defines __start_SECNAME and __stop_SECNAME
-                symbols that designate the start and end of the section.])
+     [whether $CC has <threads.h> that supports thread_local],
+     [ovs_cv_thread_local],
+     [AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM([#include <threads.h>
+static thread_local int var;], [return var;])],
+        [ovs_cv_thread_local=yes],
+        [ovs_cv_thread_local=no])])
+   if test $ovs_cv_thread_local = yes; then
+     AC_DEFINE([HAVE_THREAD_LOCAL], [1],
+               [Define to 1 if the C compiler and linker supports the C11
+                thread_local matcro defined in <threads.h>.])
+   else
+     AC_CACHE_CHECK(
+       [whether $CC supports __thread],
+       [ovs_cv___thread],
+       [AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM([static __thread int var;], [return var;])],
+          [ovs_cv___thread=yes],
+          [ovs_cv___thread=no])])
+     if test $ovs_cv___thread = yes; then
+       AC_DEFINE([HAVE___THREAD], [1],
+                 [Define to 1 if the C compiler and linker supports the
+                  GCC __thread extenions.])
+     fi
+   fi])
+
+dnl OVS_CHECK_ATOMIC_LIBS
+dnl
+dnl Check to see if -latomic is need for GCC atomic built-ins.
+AC_DEFUN([OVS_CHECK_ATOMIC_LIBS],
+   [AC_SEARCH_LIBS([__atomic_load_8], [atomic])])
+
+dnl OVS_CHECK_GCC4_ATOMICS
+dnl
+dnl Checks whether the compiler and linker support GCC 4.0+ atomic built-ins.
+dnl A compile-time only check is not enough because the compiler defers
+dnl unimplemented built-ins to libgcc, which sometimes also lacks
+dnl implementations.
+AC_DEFUN([OVS_CHECK_GCC4_ATOMICS],
+  [AC_CACHE_CHECK(
+     [whether $CC supports GCC 4.0+ atomic built-ins],
+     [ovs_cv_gcc4_atomics],
+     [AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM([[#include <stdlib.h>
+
+#define ovs_assert(expr) if (!(expr)) abort();
+#define TEST_ATOMIC_TYPE(TYPE)                  \
+    {                                           \
+        TYPE x = 1;                             \
+        TYPE orig;                              \
+                                                \
+        __sync_synchronize();                   \
+        ovs_assert(x == 1);                     \
+                                                \
+        __sync_synchronize();                   \
+        x = 3;                                  \
+        __sync_synchronize();                   \
+        ovs_assert(x == 3);                     \
+                                                \
+        orig = __sync_fetch_and_add(&x, 1);     \
+        ovs_assert(orig == 3);                  \
+        __sync_synchronize();                   \
+        ovs_assert(x == 4);                     \
+                                                \
+        orig = __sync_fetch_and_sub(&x, 2);     \
+        ovs_assert(orig == 4);                  \
+        __sync_synchronize();                   \
+        ovs_assert(x == 2);                     \
+                                                \
+        orig = __sync_fetch_and_or(&x, 6);      \
+        ovs_assert(orig == 2);                  \
+        __sync_synchronize();                   \
+        ovs_assert(x == 6);                     \
+                                                \
+        orig = __sync_fetch_and_and(&x, 10);    \
+        ovs_assert(orig == 6);                  \
+        __sync_synchronize();                   \
+        ovs_assert(x == 2);                     \
+                                                \
+        orig = __sync_fetch_and_xor(&x, 10);    \
+        ovs_assert(orig == 2);                  \
+        __sync_synchronize();                   \
+        ovs_assert(x == 8);                     \
+    }]], [dnl
+TEST_ATOMIC_TYPE(char);
+TEST_ATOMIC_TYPE(unsigned char);
+TEST_ATOMIC_TYPE(signed char);
+TEST_ATOMIC_TYPE(short);
+TEST_ATOMIC_TYPE(unsigned short);
+TEST_ATOMIC_TYPE(int);
+TEST_ATOMIC_TYPE(unsigned int);
+TEST_ATOMIC_TYPE(long int);
+TEST_ATOMIC_TYPE(unsigned long int);
+TEST_ATOMIC_TYPE(long long int);
+TEST_ATOMIC_TYPE(unsigned long long int);
+])],
+        [ovs_cv_gcc4_atomics=yes],
+        [ovs_cv_gcc4_atomics=no])])
+   if test $ovs_cv_gcc4_atomics = yes; then
+     AC_DEFINE([HAVE_GCC4_ATOMICS], [1],
+               [Define to 1 if the C compiler and linker supports the GCC 4.0+
+                atomic built-ins.])
+   fi])
+
+dnl OVS_CHECK_ATOMIC_ALWAYS_LOCK_FREE(SIZE)
+dnl
+dnl Checks __atomic_always_lock_free(SIZE, 0)
+AC_DEFUN([OVS_CHECK_ATOMIC_ALWAYS_LOCK_FREE], 
+  [AC_CACHE_CHECK(
+    [value of __atomic_always_lock_free($1)],
+    [ovs_cv_atomic_always_lock_free_$1],
+    [AC_COMPUTE_INT(
+        [ovs_cv_atomic_always_lock_free_$1],
+        [__atomic_always_lock_free($1, 0)],
+        [],
+        [ovs_cv_atomic_always_lock_free_$1=unsupported])])
+   if test ovs_cv_atomic_always_lock_free_$1 != unsupported; then
+     AC_DEFINE_UNQUOTED(
+       [ATOMIC_ALWAYS_LOCK_FREE_$1B],
+       [$ovs_cv_atomic_always_lock_free_$1],
+       [If the C compiler is GCC 4.7 or later, define to the return value of
+        __atomic_always_lock_free($1, 0).  If the C compiler is not GCC or is
+        an older version of GCC, the value does not matter.])
    fi])
+
+dnl OVS_CHECK_POSIX_AIO
+AC_DEFUN([OVS_CHECK_POSIX_AIO],
+  [AC_SEARCH_LIBS([aio_write], [rt])
+   AM_CONDITIONAL([HAVE_POSIX_AIO], [test "$ac_cv_search_aio_write" != no])])
+
+dnl OVS_CHECK_INCLUDE_NEXT
+AC_DEFUN([OVS_CHECK_INCLUDE_NEXT],
+  [AC_REQUIRE([gl_CHECK_NEXT_HEADERS])
+   gl_CHECK_NEXT_HEADERS([$1])])