6 static const char show_branch_usage[] =
7 "git-show-branch [--all] [--heads] [--tags] [--more=count] [<refs>...]";
9 #define UNINTERESTING 01
12 #define MAX_REVS 29 /* should not exceed bits_per_int - REV_SHIFT */
14 static struct commit *interesting(struct commit_list *list)
17 struct commit *commit = list->item;
19 if (commit->object.flags & UNINTERESTING)
26 static struct commit *pop_one_commit(struct commit_list **list_p)
28 struct commit *commit;
29 struct commit_list *list;
38 int head_rev; /* which head's ancestor? */
39 int generation; /* how many parents away from head_rev */
42 /* Name the commit as nth generation ancestor of head_rev;
43 * we count only the first-parent relationship for naming purposes.
45 static void name_commit(struct commit *commit, int head_rev, int nth)
47 struct commit_name *name;
48 if (!commit->object.util)
49 commit->object.util = xmalloc(sizeof(struct commit_name));
50 name = commit->object.util;
51 name->head_rev = head_rev;
52 name->generation = nth;
55 /* Parent is the first parent of the commit. We may name it
56 * as (n+1)th generation ancestor of the same head_rev as
57 * commit is nth generation ancestore of, if that generation
58 * number is better than the name it already has.
60 static void name_parent(struct commit *commit, struct commit *parent)
62 struct commit_name *commit_name = commit->object.util;
63 struct commit_name *parent_name = parent->object.util;
67 commit_name->generation + 1 < parent_name->generation)
68 name_commit(parent, commit_name->head_rev,
69 commit_name->generation + 1);
72 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
74 if (!commit->object.flags) {
75 insert_by_date(commit, seen_p);
81 static void join_revs(struct commit_list **list_p,
82 struct commit_list **seen_p,
83 int num_rev, int extra)
85 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
86 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
89 struct commit_list *parents;
90 struct commit *commit = pop_one_commit(list_p);
91 int flags = commit->object.flags & all_mask;
93 int still_interesting = !!interesting(*list_p);
95 if (!still_interesting && extra < 0)
98 mark_seen(commit, seen_p);
99 if ((flags & all_revs) == all_revs)
100 flags |= UNINTERESTING;
101 parents = commit->parents;
104 struct commit *p = parents->item;
105 int this_flag = p->object.flags;
106 parents = parents->next;
109 name_parent(commit, p);
111 if ((this_flag & flags) == flags)
114 if (mark_seen(p, seen_p) && !still_interesting)
116 p->object.flags |= flags;
117 insert_by_date(p, list_p);
122 static void show_one_commit(struct commit *commit, char **head_name)
124 char pretty[128], *cp;
125 struct commit_name *name = commit->object.util;
126 pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
127 pretty, sizeof(pretty));
128 if (!strncmp(pretty, "[PATCH] ", 8))
132 if (name && head_name) {
133 printf("[%s", head_name[name->head_rev]);
134 if (name->generation)
135 printf("~%d", name->generation);
141 static char *ref_name[MAX_REVS + 1];
142 static int ref_name_cnt;
144 static int compare_ref_name(const void *a_, const void *b_)
146 const char * const*a = a_, * const*b = b_;
147 return strcmp(*a, *b);
150 static void sort_ref_range(int bottom, int top)
152 qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
156 static int append_ref(const char *refname, const unsigned char *sha1)
158 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
161 if (MAX_REVS < ref_name_cnt) {
162 fprintf(stderr, "warning: ignoring %s; "
163 "cannot handle more than %d refs",
167 ref_name[ref_name_cnt++] = strdup(refname);
168 ref_name[ref_name_cnt] = NULL;
172 static int append_head_ref(const char *refname, const unsigned char *sha1)
174 if (strncmp(refname, "refs/heads/", 11))
176 return append_ref(refname + 11, sha1);
179 static int append_tag_ref(const char *refname, const unsigned char *sha1)
181 if (strncmp(refname, "refs/tags/", 10))
183 return append_ref(refname + 5, sha1);
186 static void snarf_refs(int head, int tag)
189 int orig_cnt = ref_name_cnt;
190 for_each_ref(append_head_ref);
191 sort_ref_range(orig_cnt, ref_name_cnt);
194 int orig_cnt = ref_name_cnt;
195 for_each_ref(append_tag_ref);
196 sort_ref_range(orig_cnt, ref_name_cnt);
200 static int rev_is_head(char *head_path, int headlen,
202 unsigned char *head_sha1, unsigned char *sha1)
205 if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
207 namelen = strlen(name);
208 if ((headlen < namelen) ||
209 memcmp(head_path + headlen - namelen, name, namelen))
211 if (headlen == namelen ||
212 head_path[headlen - namelen - 1] == '/')
217 static int show_merge_base(struct commit_list *seen, int num_rev)
219 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
220 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
223 struct commit *commit = pop_one_commit(&seen);
224 int flags = commit->object.flags & all_mask;
225 if (!(flags & UNINTERESTING) &&
226 ((flags & all_revs) == all_revs)) {
227 puts(sha1_to_hex(commit->object.sha1));
234 int main(int ac, char **av)
236 struct commit *rev[MAX_REVS], *commit;
237 struct commit_list *list = NULL, *seen = NULL;
238 int num_rev, i, extra = 0;
239 int all_heads = 0, all_tags = 0;
242 unsigned char head_sha1[20];
246 while (1 < ac && av[1][0] == '-') {
248 if (!strcmp(arg, "--all"))
249 all_heads = all_tags = 1;
250 else if (!strcmp(arg, "--heads"))
252 else if (!strcmp(arg, "--tags"))
254 else if (!strcmp(arg, "--more"))
256 else if (!strncmp(arg, "--more=", 7)) {
257 extra = atoi(arg + 7);
259 usage(show_branch_usage);
261 else if (!strcmp(arg, "--merge-base"))
264 usage(show_branch_usage);
269 if (all_heads + all_tags)
270 snarf_refs(all_heads, all_tags);
273 unsigned char revkey[20];
274 if (get_sha1(*av, revkey))
275 die("bad sha1 reference %s", *av);
276 append_ref(*av, revkey);
280 /* If still no revs, then add heads */
284 for (num_rev = 0; ref_name[num_rev]; num_rev++) {
285 unsigned char revkey[20];
287 if (MAX_REVS <= num_rev)
288 die("cannot handle more than %d revs.", MAX_REVS);
289 if (get_sha1(ref_name[num_rev], revkey))
290 usage(show_branch_usage);
291 commit = lookup_commit_reference(revkey);
293 die("cannot find commit %s (%s)",
294 ref_name[num_rev], revkey);
295 parse_commit(commit);
296 if (!commit->object.util)
297 name_commit(commit, num_rev, 0);
298 mark_seen(commit, &seen);
300 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
301 * and so on. REV_SHIFT bits from bit 0 are used for
302 * internal bookkeeping.
304 commit->object.flags |= 1u << (num_rev + REV_SHIFT);
305 insert_by_date(commit, &list);
306 rev[num_rev] = commit;
308 join_revs(&list, &seen, num_rev, extra);
310 head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
311 if ((head_path_len < 0) || get_sha1("HEAD", head_sha1))
314 head_path[head_path_len] = 0;
317 return show_merge_base(seen, num_rev);
321 for (i = 0; i < num_rev; i++) {
323 int is_head = rev_is_head(head_path,
327 rev[i]->object.sha1);
328 for (j = 0; j < i; j++)
330 printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
331 show_one_commit(rev[i], NULL);
333 for (i = 0; i < num_rev; i++)
340 struct commit *commit = pop_one_commit(&seen);
341 int this_flag = commit->object.flags;
342 static char *obvious[] = { "" };
344 if ((this_flag & UNINTERESTING) && (--extra < 0))
347 for (i = 0; i < num_rev; i++)
348 putchar((this_flag & (1u << (i + REV_SHIFT)))
352 show_one_commit(commit, label);