-# lock.m4 serial 6 (gettext-0.16)
-dnl Copyright (C) 2005-2006 Free Software Foundation, Inc.
+# lock.m4 serial 7 (gettext-0.16)
+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
+ AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) dnl needed for pthread_rwlock_t on glibc systems
dnl Check for multithreading.
AC_ARG_ENABLE(threads,
AC_HELP_STRING([--enable-threads={posix|solaris|pth|win32}], [specify multithreading API])
AC_REQUIRE([AC_C_INLINE])
])
+# AC_USE_SYSTEM_EXTENSIONS was only added in autoconf 2.60, but lock.m4
+# wants to work with autoconf 2.54. Add a fallback until such time as
+# a newer autoconf is standard, if one is not already provided by gnulib
+# extensions.m4.
+m4_if(m4_version_compare(m4_PACKAGE_VERSION, [2.60]), [-1],
+ [m4_ifndef([AC_USE_SYSTEM_EXTENSIONS],
+ [AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS], [AC_GNU_SOURCE])])])
+
dnl Survey of platforms:
dnl
dnl Platform Available Compiler Supports test-lock