-void __lock(volatile int *);
-void __lockfile(FILE *);
-#define LOCK(x) (libc.threads_minus_1 ? (__lock(x),1) : ((void)(x),1))
-#define UNLOCK(x) (*(x)=0)
-#define CANCELPT(x) (libc.cancelpt ? libc.cancelpt((x)),0 : (void)(x),0)
-#define CANCELPT_BEGIN CANCELPT(1)
-#define CANCELPT_END CANCELPT(0)
+void __lock(volatile int *) ATTR_LIBC_VISIBILITY;
+void __unlock(volatile int *) ATTR_LIBC_VISIBILITY;
+int __lockfile(FILE *) ATTR_LIBC_VISIBILITY;
+void __unlockfile(FILE *) ATTR_LIBC_VISIBILITY;
+#define LOCK(x) __lock(x)
+#define UNLOCK(x) __unlock(x)
+
+void __synccall(void (*)(void *), void *);
+int __setxid(int, int, int, int);