reachable.hon commit fsck: it is OK for a tag and a commit to lack the body (84d18c0)
   1#ifndef REACHEABLE_H
   2#define REACHEABLE_H
   3
   4struct progress;
   5extern void mark_reachable_objects(struct rev_info *revs, int mark_reflog, struct progress *);
   6
   7#endif