-# lock.m4 serial 6 (gettext-0.16)
-dnl Copyright (C) 2005-2006 Free Software Foundation, Inc.
+# lock.m4 serial 7 (gettext-0.17)
+dnl Copyright (C) 2005-2007 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_BEFORE([$0], [gl_ARGP])dnl
AC_REQUIRE([AC_CANONICAL_HOST])
- AC_REQUIRE([AC_GNU_SOURCE]) dnl needed for pthread_rwlock_t on glibc systems
+ dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems.
+ dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes
+ dnl AC_GNU_SOURCE.
+ m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],
+ [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])],
+ [AC_REQUIRE([AC_GNU_SOURCE])])
dnl Check for multithreading.
AC_ARG_ENABLE(threads,
AC_HELP_STRING([--enable-threads={posix|solaris|pth|win32}], [specify multithreading API])