#define diff_debug_queue(a,b) do {} while(0)
 #endif
 
+extern int diffcore_count_changes(void *src, unsigned long src_size,
+                                 void *dst, unsigned long dst_size,
+                                 unsigned long delta_limit,
+                                 unsigned long *src_copied,
+                                 unsigned long *literal_added);
+
 #endif