+extern int chk_zero(int result, char *msg);
+extern int chk_positive(int result, char *msg);
+
+extern int hextoint(char c);
+
+extern void *cgit_free_commitinfo(struct commitinfo *info);
+
+extern int cgit_diff_files(const unsigned char *old_sha1,
+ const unsigned char *new_sha1,
+ linediff_fn fn);
+
+extern void cgit_diff_tree(const unsigned char *old_sha1,
+ const unsigned char *new_sha1,
+ filepair_fn fn);
+
+extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
+