extern void diff_tree_setup_paths(const char **paths, struct diff_options *);
extern void diff_tree_release_paths(struct diff_options *);
extern int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
extern void diff_tree_setup_paths(const char **paths, struct diff_options *);
extern void diff_tree_release_paths(struct diff_options *);
extern int diff_tree(struct tree_desc *t1, struct tree_desc *t2,