Function describe_commit

builtin/describe.c:365–536

}

static void describe_commit(struct commit *cmit, struct strbuf *dst)
{
	struct commit *gave_up_on = NULL;
	struct lazy_queue queue = LAZY_QUEUE_INIT;
	struct commit_name *n;
	struct possible_tag all_matches[MAX_TAGS];
	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
	unsigned long seen_commits = 0;
	unsigned int unannotated_cnt = 0;

	n = find_commit_name(&cmit->object.oid);
	if (n && (tags || all || n->prio == 2)) {
		/*
		 * Exact match to an existing ref.
		 */
		append_name(n, dst);
		if (n->misnamed || longformat)
			append_suffix(0, n->tag ? get_tagged_oid(n->tag) : &cmit->object.oid, dst);
		if (suffix)
			strbuf_addstr(dst, suffix);
		return;
	}

	if (!max_candidates)
		die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
	if (debug)
		fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));

	if (!have_util) {
		struct hashmap_iter iter;
		struct commit *c;
		struct commit_name *n;

		init_commit_names(&commit_names);
		hashmap_for_each_entry(&names, &iter, n,
					entry /* member name */) {
			c = lookup_commit_reference_gently(the_repository,
							   &n->peeled, 1);
			if (c)
				*commit_names_at(&commit_names, c) = n;
		}
		have_util = 1;
	}

	cmit->object.flags = SEEN;
	lazy_queue_put(&queue, cmit);
	while (!lazy_queue_empty(&queue)) {
		struct commit *c = lazy_queue_get(&queue);
		struct commit_list *parents = c->parents;
		struct commit_name **slot;

		seen_commits++;

		if (match_cnt == max_candidates ||
		    match_cnt == hashmap_get_size(&names)) {
			gave_up_on = c;
			break;
		}