extern int run_diff_files(struct rev_info *revs, unsigned int option);
extern int run_diff_index(struct rev_info *revs, int cached);
-extern int do_diff_cache(const unsigned char *, struct diff_options *);
+extern int do_diff_cache(const struct object_id *, struct diff_options *);
extern int diff_flush_patch_id(struct diff_options *, unsigned char *, int);
extern int diff_result_code(struct diff_options *, int);