add more informative error messages to git-mktag
[debian-git.git] / show-branch.c
blob268c57b180627f7d8ba3a3a754210a37d420fb0d
1 #include <stdlib.h>
2 #include <fnmatch.h>
3 #include "cache.h"
4 #include "commit.h"
5 #include "refs.h"
7 static const char show_branch_usage[] =
8 "git-show-branch [--dense] [--current] [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...]";
10 static int default_num = 0;
11 static int default_alloc = 0;
12 static char **default_arg = NULL;
14 #define UNINTERESTING 01
16 #define REV_SHIFT 2
17 #define MAX_REVS 29 /* should not exceed bits_per_int - REV_SHIFT */
19 static struct commit *interesting(struct commit_list *list)
21 while (list) {
22 struct commit *commit = list->item;
23 list = list->next;
24 if (commit->object.flags & UNINTERESTING)
25 continue;
26 return commit;
28 return NULL;
31 static struct commit *pop_one_commit(struct commit_list **list_p)
33 struct commit *commit;
34 struct commit_list *list;
35 list = *list_p;
36 commit = list->item;
37 *list_p = list->next;
38 free(list);
39 return commit;
42 struct commit_name {
43 const char *head_name; /* which head's ancestor? */
44 int generation; /* how many parents away from head_name */
47 /* Name the commit as nth generation ancestor of head_name;
48 * we count only the first-parent relationship for naming purposes.
50 static void name_commit(struct commit *commit, const char *head_name, int nth)
52 struct commit_name *name;
53 if (!commit->object.util)
54 commit->object.util = xmalloc(sizeof(struct commit_name));
55 name = commit->object.util;
56 name->head_name = head_name;
57 name->generation = nth;
60 /* Parent is the first parent of the commit. We may name it
61 * as (n+1)th generation ancestor of the same head_name as
62 * commit is nth generation ancestor of, if that generation
63 * number is better than the name it already has.
65 static void name_parent(struct commit *commit, struct commit *parent)
67 struct commit_name *commit_name = commit->object.util;
68 struct commit_name *parent_name = parent->object.util;
69 if (!commit_name)
70 return;
71 if (!parent_name ||
72 commit_name->generation + 1 < parent_name->generation)
73 name_commit(parent, commit_name->head_name,
74 commit_name->generation + 1);
77 static int name_first_parent_chain(struct commit *c)
79 int i = 0;
80 while (c) {
81 struct commit *p;
82 if (!c->object.util)
83 break;
84 if (!c->parents)
85 break;
86 p = c->parents->item;
87 if (!p->object.util) {
88 name_parent(c, p);
89 i++;
91 c = p;
93 return i;
96 static void name_commits(struct commit_list *list,
97 struct commit **rev,
98 char **ref_name,
99 int num_rev)
101 struct commit_list *cl;
102 struct commit *c;
103 int i;
105 /* First give names to the given heads */
106 for (cl = list; cl; cl = cl->next) {
107 c = cl->item;
108 if (c->object.util)
109 continue;
110 for (i = 0; i < num_rev; i++) {
111 if (rev[i] == c) {
112 name_commit(c, ref_name[i], 0);
113 break;
118 /* Then commits on the first parent ancestry chain */
119 do {
120 i = 0;
121 for (cl = list; cl; cl = cl->next) {
122 i += name_first_parent_chain(cl->item);
124 } while (i);
126 /* Finally, any unnamed commits */
127 do {
128 i = 0;
129 for (cl = list; cl; cl = cl->next) {
130 struct commit_list *parents;
131 struct commit_name *n;
132 int nth;
133 c = cl->item;
134 if (!c->object.util)
135 continue;
136 n = c->object.util;
137 parents = c->parents;
138 nth = 0;
139 while (parents) {
140 struct commit *p = parents->item;
141 char newname[1000], *en;
142 parents = parents->next;
143 nth++;
144 if (p->object.util)
145 continue;
146 en = newname;
147 switch (n->generation) {
148 case 0:
149 en += sprintf(en, "%s", n->head_name);
150 break;
151 case 1:
152 en += sprintf(en, "%s^", n->head_name);
153 break;
154 default:
155 en += sprintf(en, "%s~%d",
156 n->head_name, n->generation);
157 break;
159 if (nth == 1)
160 en += sprintf(en, "^");
161 else
162 en += sprintf(en, "^%d", nth);
163 name_commit(p, strdup(newname), 0);
164 i++;
165 name_first_parent_chain(p);
168 } while (i);
171 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
173 if (!commit->object.flags) {
174 insert_by_date(commit, seen_p);
175 return 1;
177 return 0;
180 static void join_revs(struct commit_list **list_p,
181 struct commit_list **seen_p,
182 int num_rev, int extra)
184 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
185 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
187 while (*list_p) {
188 struct commit_list *parents;
189 int still_interesting = !!interesting(*list_p);
190 struct commit *commit = pop_one_commit(list_p);
191 int flags = commit->object.flags & all_mask;
193 if (!still_interesting && extra <= 0)
194 break;
196 mark_seen(commit, seen_p);
197 if ((flags & all_revs) == all_revs)
198 flags |= UNINTERESTING;
199 parents = commit->parents;
201 while (parents) {
202 struct commit *p = parents->item;
203 int this_flag = p->object.flags;
204 parents = parents->next;
205 if ((this_flag & flags) == flags)
206 continue;
207 if (!p->object.parsed)
208 parse_commit(p);
209 if (mark_seen(p, seen_p) && !still_interesting)
210 extra--;
211 p->object.flags |= flags;
212 insert_by_date(p, list_p);
217 * Postprocess to complete well-poisoning.
219 * At this point we have all the commits we have seen in
220 * seen_p list (which happens to be sorted chronologically but
221 * it does not really matter). Mark anything that can be
222 * reached from uninteresting commits not interesting.
224 for (;;) {
225 int changed = 0;
226 struct commit_list *s;
227 for (s = *seen_p; s; s = s->next) {
228 struct commit *c = s->item;
229 struct commit_list *parents;
231 if (((c->object.flags & all_revs) != all_revs) &&
232 !(c->object.flags & UNINTERESTING))
233 continue;
235 /* The current commit is either a merge base or
236 * already uninteresting one. Mark its parents
237 * as uninteresting commits _only_ if they are
238 * already parsed. No reason to find new ones
239 * here.
241 parents = c->parents;
242 while (parents) {
243 struct commit *p = parents->item;
244 parents = parents->next;
245 if (!(p->object.flags & UNINTERESTING)) {
246 p->object.flags |= UNINTERESTING;
247 changed = 1;
251 if (!changed)
252 break;
256 static void show_one_commit(struct commit *commit, int no_name)
258 char pretty[256], *cp;
259 struct commit_name *name = commit->object.util;
260 if (commit->object.parsed)
261 pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
262 pretty, sizeof(pretty), 0);
263 else
264 strcpy(pretty, "(unavailable)");
265 if (!strncmp(pretty, "[PATCH] ", 8))
266 cp = pretty + 8;
267 else
268 cp = pretty;
270 if (!no_name) {
271 if (name && name->head_name) {
272 printf("[%s", name->head_name);
273 if (name->generation) {
274 if (name->generation == 1)
275 printf("^");
276 else
277 printf("~%d", name->generation);
279 printf("] ");
281 else
282 printf("[%s] ",
283 find_unique_abbrev(commit->object.sha1, 7));
285 puts(cp);
288 static char *ref_name[MAX_REVS + 1];
289 static int ref_name_cnt;
291 static const char *find_digit_prefix(const char *s, int *v)
293 const char *p;
294 int ver;
295 char ch;
297 for (p = s, ver = 0;
298 '0' <= (ch = *p) && ch <= '9';
299 p++)
300 ver = ver * 10 + ch - '0';
301 *v = ver;
302 return p;
306 static int version_cmp(const char *a, const char *b)
308 while (1) {
309 int va, vb;
311 a = find_digit_prefix(a, &va);
312 b = find_digit_prefix(b, &vb);
313 if (va != vb)
314 return va - vb;
316 while (1) {
317 int ca = *a;
318 int cb = *b;
319 if ('0' <= ca && ca <= '9')
320 ca = 0;
321 if ('0' <= cb && cb <= '9')
322 cb = 0;
323 if (ca != cb)
324 return ca - cb;
325 if (!ca)
326 break;
327 a++;
328 b++;
330 if (!*a && !*b)
331 return 0;
335 static int compare_ref_name(const void *a_, const void *b_)
337 const char * const*a = a_, * const*b = b_;
338 return version_cmp(*a, *b);
341 static void sort_ref_range(int bottom, int top)
343 qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
344 compare_ref_name);
347 static int append_ref(const char *refname, const unsigned char *sha1)
349 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
350 int i;
352 if (!commit)
353 return 0;
354 /* Avoid adding the same thing twice */
355 for (i = 0; i < ref_name_cnt; i++)
356 if (!strcmp(refname, ref_name[i]))
357 return 0;
359 if (MAX_REVS <= ref_name_cnt) {
360 fprintf(stderr, "warning: ignoring %s; "
361 "cannot handle more than %d refs\n",
362 refname, MAX_REVS);
363 return 0;
365 ref_name[ref_name_cnt++] = strdup(refname);
366 ref_name[ref_name_cnt] = NULL;
367 return 0;
370 static int append_head_ref(const char *refname, const unsigned char *sha1)
372 unsigned char tmp[20];
373 int ofs = 11;
374 if (strncmp(refname, "refs/heads/", ofs))
375 return 0;
376 /* If both heads/foo and tags/foo exists, get_sha1 would
377 * get confused.
379 if (get_sha1(refname + ofs, tmp) || memcmp(tmp, sha1, 20))
380 ofs = 5;
381 return append_ref(refname + ofs, sha1);
384 static int append_tag_ref(const char *refname, const unsigned char *sha1)
386 if (strncmp(refname, "refs/tags/", 10))
387 return 0;
388 return append_ref(refname + 5, sha1);
391 static const char *match_ref_pattern = NULL;
392 static int match_ref_slash = 0;
393 static int count_slash(const char *s)
395 int cnt = 0;
396 while (*s)
397 if (*s++ == '/')
398 cnt++;
399 return cnt;
402 static int append_matching_ref(const char *refname, const unsigned char *sha1)
404 /* we want to allow pattern hold/<asterisk> to show all
405 * branches under refs/heads/hold/, and v0.99.9? to show
406 * refs/tags/v0.99.9a and friends.
408 const char *tail;
409 int slash = count_slash(refname);
410 for (tail = refname; *tail && match_ref_slash < slash; )
411 if (*tail++ == '/')
412 slash--;
413 if (!*tail)
414 return 0;
415 if (fnmatch(match_ref_pattern, tail, 0))
416 return 0;
417 if (!strncmp("refs/heads/", refname, 11))
418 return append_head_ref(refname, sha1);
419 if (!strncmp("refs/tags/", refname, 10))
420 return append_tag_ref(refname, sha1);
421 return append_ref(refname, sha1);
424 static void snarf_refs(int head, int tag)
426 if (head) {
427 int orig_cnt = ref_name_cnt;
428 for_each_ref(append_head_ref);
429 sort_ref_range(orig_cnt, ref_name_cnt);
431 if (tag) {
432 int orig_cnt = ref_name_cnt;
433 for_each_ref(append_tag_ref);
434 sort_ref_range(orig_cnt, ref_name_cnt);
438 static int rev_is_head(char *head_path, int headlen, char *name,
439 unsigned char *head_sha1, unsigned char *sha1)
441 int namelen;
442 if ((!head_path[0]) ||
443 (head_sha1 && sha1 && memcmp(head_sha1, sha1, 20)))
444 return 0;
445 namelen = strlen(name);
446 if ((headlen < namelen) ||
447 memcmp(head_path + headlen - namelen, name, namelen))
448 return 0;
449 if (headlen == namelen ||
450 head_path[headlen - namelen - 1] == '/')
451 return 1;
452 return 0;
455 static int show_merge_base(struct commit_list *seen, int num_rev)
457 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
458 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
459 int exit_status = 1;
461 while (seen) {
462 struct commit *commit = pop_one_commit(&seen);
463 int flags = commit->object.flags & all_mask;
464 if (!(flags & UNINTERESTING) &&
465 ((flags & all_revs) == all_revs)) {
466 puts(sha1_to_hex(commit->object.sha1));
467 exit_status = 0;
468 commit->object.flags |= UNINTERESTING;
471 return exit_status;
474 static int show_independent(struct commit **rev,
475 int num_rev,
476 char **ref_name,
477 unsigned int *rev_mask)
479 int i;
481 for (i = 0; i < num_rev; i++) {
482 struct commit *commit = rev[i];
483 unsigned int flag = rev_mask[i];
485 if (commit->object.flags == flag)
486 puts(sha1_to_hex(commit->object.sha1));
487 commit->object.flags |= UNINTERESTING;
489 return 0;
492 static void append_one_rev(const char *av)
494 unsigned char revkey[20];
495 if (!get_sha1(av, revkey)) {
496 append_ref(av, revkey);
497 return;
499 if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
500 /* glob style match */
501 int saved_matches = ref_name_cnt;
502 match_ref_pattern = av;
503 match_ref_slash = count_slash(av);
504 for_each_ref(append_matching_ref);
505 if (saved_matches == ref_name_cnt &&
506 ref_name_cnt < MAX_REVS)
507 error("no matching refs with %s", av);
508 if (saved_matches + 1 < ref_name_cnt)
509 sort_ref_range(saved_matches, ref_name_cnt);
510 return;
512 die("bad sha1 reference %s", av);
515 static int git_show_branch_config(const char *var, const char *value)
517 if (!strcmp(var, "showbranch.default")) {
518 if (default_alloc <= default_num + 1) {
519 default_alloc = default_alloc * 3 / 2 + 20;
520 default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
522 default_arg[default_num++] = strdup(value);
523 default_arg[default_num] = NULL;
524 return 0;
527 return git_default_config(var, value);
530 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
532 /* If the commit is tip of the named branches, do not
533 * omit it.
534 * Otherwise, if it is a merge that is reachable from only one
535 * tip, it is not that interesting.
537 int i, flag, count;
538 for (i = 0; i < n; i++)
539 if (rev[i] == commit)
540 return 0;
541 flag = commit->object.flags;
542 for (i = count = 0; i < n; i++) {
543 if (flag & (1u << (i + REV_SHIFT)))
544 count++;
546 if (count == 1)
547 return 1;
548 return 0;
551 int main(int ac, char **av)
553 struct commit *rev[MAX_REVS], *commit;
554 struct commit_list *list = NULL, *seen = NULL;
555 unsigned int rev_mask[MAX_REVS];
556 int num_rev, i, extra = 0;
557 int all_heads = 0, all_tags = 0;
558 int all_mask, all_revs;
559 int lifo = 1;
560 char head_path[128];
561 const char *head_path_p;
562 int head_path_len;
563 unsigned char head_sha1[20];
564 int merge_base = 0;
565 int independent = 0;
566 int no_name = 0;
567 int sha1_name = 0;
568 int shown_merge_point = 0;
569 int with_current_branch = 0;
570 int head_at = -1;
571 int topics = 0;
572 int dense = 1;
574 setup_git_directory();
575 git_config(git_show_branch_config);
577 /* If nothing is specified, try the default first */
578 if (ac == 1 && default_num) {
579 ac = default_num + 1;
580 av = default_arg - 1; /* ick; we would not address av[0] */
583 while (1 < ac && av[1][0] == '-') {
584 char *arg = av[1];
585 if (!strcmp(arg, "--")) {
586 ac--; av++;
587 break;
589 else if (!strcmp(arg, "--all"))
590 all_heads = all_tags = 1;
591 else if (!strcmp(arg, "--heads"))
592 all_heads = 1;
593 else if (!strcmp(arg, "--tags"))
594 all_tags = 1;
595 else if (!strcmp(arg, "--more"))
596 extra = 1;
597 else if (!strcmp(arg, "--list"))
598 extra = -1;
599 else if (!strcmp(arg, "--no-name"))
600 no_name = 1;
601 else if (!strcmp(arg, "--current"))
602 with_current_branch = 1;
603 else if (!strcmp(arg, "--sha1-name"))
604 sha1_name = 1;
605 else if (!strncmp(arg, "--more=", 7))
606 extra = atoi(arg + 7);
607 else if (!strcmp(arg, "--merge-base"))
608 merge_base = 1;
609 else if (!strcmp(arg, "--independent"))
610 independent = 1;
611 else if (!strcmp(arg, "--topo-order"))
612 lifo = 1;
613 else if (!strcmp(arg, "--topics"))
614 topics = 1;
615 else if (!strcmp(arg, "--sparse"))
616 dense = 0;
617 else if (!strcmp(arg, "--date-order"))
618 lifo = 0;
619 else
620 usage(show_branch_usage);
621 ac--; av++;
623 ac--; av++;
625 /* Only one of these is allowed */
626 if (1 < independent + merge_base + (extra != 0))
627 usage(show_branch_usage);
629 /* If nothing is specified, show all branches by default */
630 if (ac + all_heads + all_tags == 0)
631 all_heads = 1;
633 if (all_heads + all_tags)
634 snarf_refs(all_heads, all_tags);
635 while (0 < ac) {
636 append_one_rev(*av);
637 ac--; av++;
640 head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
641 if (head_path_p) {
642 head_path_len = strlen(head_path_p);
643 memcpy(head_path, head_path_p, head_path_len + 1);
645 else {
646 head_path_len = 0;
647 head_path[0] = 0;
650 if (with_current_branch && head_path_p) {
651 int has_head = 0;
652 for (i = 0; !has_head && i < ref_name_cnt; i++) {
653 /* We are only interested in adding the branch
654 * HEAD points at.
656 if (rev_is_head(head_path,
657 head_path_len,
658 ref_name[i],
659 head_sha1, NULL))
660 has_head++;
662 if (!has_head) {
663 int pfxlen = strlen(git_path("refs/heads/"));
664 append_one_rev(head_path + pfxlen);
668 if (!ref_name_cnt) {
669 fprintf(stderr, "No revs to be shown.\n");
670 exit(0);
673 for (num_rev = 0; ref_name[num_rev]; num_rev++) {
674 unsigned char revkey[20];
675 unsigned int flag = 1u << (num_rev + REV_SHIFT);
677 if (MAX_REVS <= num_rev)
678 die("cannot handle more than %d revs.", MAX_REVS);
679 if (get_sha1(ref_name[num_rev], revkey))
680 die("'%s' is not a valid ref.", ref_name[num_rev]);
681 commit = lookup_commit_reference(revkey);
682 if (!commit)
683 die("cannot find commit %s (%s)",
684 ref_name[num_rev], revkey);
685 parse_commit(commit);
686 mark_seen(commit, &seen);
688 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
689 * and so on. REV_SHIFT bits from bit 0 are used for
690 * internal bookkeeping.
692 commit->object.flags |= flag;
693 if (commit->object.flags == flag)
694 insert_by_date(commit, &list);
695 rev[num_rev] = commit;
697 for (i = 0; i < num_rev; i++)
698 rev_mask[i] = rev[i]->object.flags;
700 if (0 <= extra)
701 join_revs(&list, &seen, num_rev, extra);
703 if (merge_base)
704 return show_merge_base(seen, num_rev);
706 if (independent)
707 return show_independent(rev, num_rev, ref_name, rev_mask);
709 /* Show list; --more=-1 means list-only */
710 if (1 < num_rev || extra < 0) {
711 for (i = 0; i < num_rev; i++) {
712 int j;
713 int is_head = rev_is_head(head_path,
714 head_path_len,
715 ref_name[i],
716 head_sha1,
717 rev[i]->object.sha1);
718 if (extra < 0)
719 printf("%c [%s] ",
720 is_head ? '*' : ' ', ref_name[i]);
721 else {
722 for (j = 0; j < i; j++)
723 putchar(' ');
724 printf("%c [%s] ",
725 is_head ? '*' : '!', ref_name[i]);
727 /* header lines never need name */
728 show_one_commit(rev[i], 1);
729 if (is_head)
730 head_at = i;
732 if (0 <= extra) {
733 for (i = 0; i < num_rev; i++)
734 putchar('-');
735 putchar('\n');
738 if (extra < 0)
739 exit(0);
741 /* Sort topologically */
742 sort_in_topological_order(&seen, lifo);
744 /* Give names to commits */
745 if (!sha1_name && !no_name)
746 name_commits(seen, rev, ref_name, num_rev);
748 all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
749 all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
751 while (seen) {
752 struct commit *commit = pop_one_commit(&seen);
753 int this_flag = commit->object.flags;
754 int is_merge_point = ((this_flag & all_revs) == all_revs);
756 shown_merge_point |= is_merge_point;
758 if (1 < num_rev) {
759 int is_merge = !!(commit->parents &&
760 commit->parents->next);
761 if (topics &&
762 !is_merge_point &&
763 (this_flag & (1u << REV_SHIFT)))
764 continue;
765 if (dense && is_merge &&
766 omit_in_dense(commit, rev, num_rev))
767 continue;
768 for (i = 0; i < num_rev; i++) {
769 int mark;
770 if (!(this_flag & (1u << (i + REV_SHIFT))))
771 mark = ' ';
772 else if (is_merge)
773 mark = '-';
774 else if (i == head_at)
775 mark = '*';
776 else
777 mark = '+';
778 putchar(mark);
780 putchar(' ');
782 show_one_commit(commit, no_name);
784 if (shown_merge_point && --extra < 0)
785 break;
787 return 0;