#ifndef _SYS_TREE_H_
#define _SYS_TREE_H_
-#include <sys/cdefs.h>
-
+#ifdef __GNUC__
+#ifndef __unused
+#define __unused __attribute__ ((__unused__))
+#endif
+#endif
/*
* This file defines data structures for different types of trees:
* splay trees and red-black trees.