1#include <stdlib.h>
2#include <fnmatch.h>
3#include "cache.h"
4#include "commit.h"
5#include "refs.h"
6#include "builtin.h"
7
8static const char show_branch_usage[] =
9"git-show-branch [--sparse] [--current] [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [--topics] [<refs>...]";
10
11static int default_num;
12static int default_alloc;
13static const char **default_arg;
14
15#define UNINTERESTING 01
16
17#define REV_SHIFT 2
18#define MAX_REVS (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
19
20static struct commit *interesting(struct commit_list *list)
21{
22 while (list) {
23 struct commit *commit = list->item;
24 list = list->next;
25 if (commit->object.flags & UNINTERESTING)
26 continue;
27 return commit;
28 }
29 return NULL;
30}
31
32static struct commit *pop_one_commit(struct commit_list **list_p)
33{
34 struct commit *commit;
35 struct commit_list *list;
36 list = *list_p;
37 commit = list->item;
38 *list_p = list->next;
39 free(list);
40 return commit;
41}
42
43struct commit_name {
44 const char *head_name; /* which head's ancestor? */
45 int generation; /* how many parents away from head_name */
46};
47
48/* Name the commit as nth generation ancestor of head_name;
49 * we count only the first-parent relationship for naming purposes.
50 */
51static void name_commit(struct commit *commit, const char *head_name, int nth)
52{
53 struct commit_name *name;
54 if (!commit->util)
55 commit->util = xmalloc(sizeof(struct commit_name));
56 name = commit->util;
57 name->head_name = head_name;
58 name->generation = nth;
59}
60
61/* Parent is the first parent of the commit. We may name it
62 * as (n+1)th generation ancestor of the same head_name as
63 * commit is nth generation ancestor of, if that generation
64 * number is better than the name it already has.
65 */
66static void name_parent(struct commit *commit, struct commit *parent)
67{
68 struct commit_name *commit_name = commit->util;
69 struct commit_name *parent_name = parent->util;
70 if (!commit_name)
71 return;
72 if (!parent_name ||
73 commit_name->generation + 1 < parent_name->generation)
74 name_commit(parent, commit_name->head_name,
75 commit_name->generation + 1);
76}
77
78static int name_first_parent_chain(struct commit *c)
79{
80 int i = 0;
81 while (c) {
82 struct commit *p;
83 if (!c->util)
84 break;
85 if (!c->parents)
86 break;
87 p = c->parents->item;
88 if (!p->util) {
89 name_parent(c, p);
90 i++;
91 }
92 else
93 break;
94 c = p;
95 }
96 return i;
97}
98
99static void name_commits(struct commit_list *list,
100 struct commit **rev,
101 char **ref_name,
102 int num_rev)
103{
104 struct commit_list *cl;
105 struct commit *c;
106 int i;
107
108 /* First give names to the given heads */
109 for (cl = list; cl; cl = cl->next) {
110 c = cl->item;
111 if (c->util)
112 continue;
113 for (i = 0; i < num_rev; i++) {
114 if (rev[i] == c) {
115 name_commit(c, ref_name[i], 0);
116 break;
117 }
118 }
119 }
120
121 /* Then commits on the first parent ancestry chain */
122 do {
123 i = 0;
124 for (cl = list; cl; cl = cl->next) {
125 i += name_first_parent_chain(cl->item);
126 }
127 } while (i);
128
129 /* Finally, any unnamed commits */
130 do {
131 i = 0;
132 for (cl = list; cl; cl = cl->next) {
133 struct commit_list *parents;
134 struct commit_name *n;
135 int nth;
136 c = cl->item;
137 if (!c->util)
138 continue;
139 n = c->util;
140 parents = c->parents;
141 nth = 0;
142 while (parents) {
143 struct commit *p = parents->item;
144 char newname[1000], *en;
145 parents = parents->next;
146 nth++;
147 if (p->util)
148 continue;
149 en = newname;
150 switch (n->generation) {
151 case 0:
152 en += sprintf(en, "%s", n->head_name);
153 break;
154 case 1:
155 en += sprintf(en, "%s^", n->head_name);
156 break;
157 default:
158 en += sprintf(en, "%s~%d",
159 n->head_name, n->generation);
160 break;
161 }
162 if (nth == 1)
163 en += sprintf(en, "^");
164 else
165 en += sprintf(en, "^%d", nth);
166 name_commit(p, strdup(newname), 0);
167 i++;
168 name_first_parent_chain(p);
169 }
170 }
171 } while (i);
172}
173
174static int mark_seen(struct commit *commit, struct commit_list **seen_p)
175{
176 if (!commit->object.flags) {
177 commit_list_insert(commit, seen_p);
178 return 1;
179 }
180 return 0;
181}
182
183static void join_revs(struct commit_list **list_p,
184 struct commit_list **seen_p,
185 int num_rev, int extra)
186{
187 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
188 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
189
190 while (*list_p) {
191 struct commit_list *parents;
192 int still_interesting = !!interesting(*list_p);
193 struct commit *commit = pop_one_commit(list_p);
194 int flags = commit->object.flags & all_mask;
195
196 if (!still_interesting && extra <= 0)
197 break;
198
199 mark_seen(commit, seen_p);
200 if ((flags & all_revs) == all_revs)
201 flags |= UNINTERESTING;
202 parents = commit->parents;
203
204 while (parents) {
205 struct commit *p = parents->item;
206 int this_flag = p->object.flags;
207 parents = parents->next;
208 if ((this_flag & flags) == flags)
209 continue;
210 if (!p->object.parsed)
211 parse_commit(p);
212 if (mark_seen(p, seen_p) && !still_interesting)
213 extra--;
214 p->object.flags |= flags;
215 insert_by_date(p, list_p);
216 }
217 }
218
219 /*
220 * Postprocess to complete well-poisoning.
221 *
222 * At this point we have all the commits we have seen in
223 * seen_p list. Mark anything that can be reached from
224 * uninteresting commits not interesting.
225 */
226 for (;;) {
227 int changed = 0;
228 struct commit_list *s;
229 for (s = *seen_p; s; s = s->next) {
230 struct commit *c = s->item;
231 struct commit_list *parents;
232
233 if (((c->object.flags & all_revs) != all_revs) &&
234 !(c->object.flags & UNINTERESTING))
235 continue;
236
237 /* The current commit is either a merge base or
238 * already uninteresting one. Mark its parents
239 * as uninteresting commits _only_ if they are
240 * already parsed. No reason to find new ones
241 * here.
242 */
243 parents = c->parents;
244 while (parents) {
245 struct commit *p = parents->item;
246 parents = parents->next;
247 if (!(p->object.flags & UNINTERESTING)) {
248 p->object.flags |= UNINTERESTING;
249 changed = 1;
250 }
251 }
252 }
253 if (!changed)
254 break;
255 }
256}
257
258static void show_one_commit(struct commit *commit, int no_name)
259{
260 char pretty[256], *cp;
261 struct commit_name *name = commit->util;
262 if (commit->object.parsed)
263 pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
264 pretty, sizeof(pretty), 0, NULL, NULL);
265 else
266 strcpy(pretty, "(unavailable)");
267 if (!strncmp(pretty, "[PATCH] ", 8))
268 cp = pretty + 8;
269 else
270 cp = pretty;
271
272 if (!no_name) {
273 if (name && name->head_name) {
274 printf("[%s", name->head_name);
275 if (name->generation) {
276 if (name->generation == 1)
277 printf("^");
278 else
279 printf("~%d", name->generation);
280 }
281 printf("] ");
282 }
283 else
284 printf("[%s] ",
285 find_unique_abbrev(commit->object.sha1, 7));
286 }
287 puts(cp);
288}
289
290static char *ref_name[MAX_REVS + 1];
291static int ref_name_cnt;
292
293static const char *find_digit_prefix(const char *s, int *v)
294{
295 const char *p;
296 int ver;
297 char ch;
298
299 for (p = s, ver = 0;
300 '0' <= (ch = *p) && ch <= '9';
301 p++)
302 ver = ver * 10 + ch - '0';
303 *v = ver;
304 return p;
305}
306
307
308static int version_cmp(const char *a, const char *b)
309{
310 while (1) {
311 int va, vb;
312
313 a = find_digit_prefix(a, &va);
314 b = find_digit_prefix(b, &vb);
315 if (va != vb)
316 return va - vb;
317
318 while (1) {
319 int ca = *a;
320 int cb = *b;
321 if ('0' <= ca && ca <= '9')
322 ca = 0;
323 if ('0' <= cb && cb <= '9')
324 cb = 0;
325 if (ca != cb)
326 return ca - cb;
327 if (!ca)
328 break;
329 a++;
330 b++;
331 }
332 if (!*a && !*b)
333 return 0;
334 }
335}
336
337static int compare_ref_name(const void *a_, const void *b_)
338{
339 const char * const*a = a_, * const*b = b_;
340 return version_cmp(*a, *b);
341}
342
343static void sort_ref_range(int bottom, int top)
344{
345 qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
346 compare_ref_name);
347}
348
349static int append_ref(const char *refname, const unsigned char *sha1)
350{
351 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
352 int i;
353
354 if (!commit)
355 return 0;
356 /* Avoid adding the same thing twice */
357 for (i = 0; i < ref_name_cnt; i++)
358 if (!strcmp(refname, ref_name[i]))
359 return 0;
360
361 if (MAX_REVS <= ref_name_cnt) {
362 fprintf(stderr, "warning: ignoring %s; "
363 "cannot handle more than %d refs\n",
364 refname, MAX_REVS);
365 return 0;
366 }
367 ref_name[ref_name_cnt++] = strdup(refname);
368 ref_name[ref_name_cnt] = NULL;
369 return 0;
370}
371
372static int append_head_ref(const char *refname, const unsigned char *sha1)
373{
374 unsigned char tmp[20];
375 int ofs = 11;
376 if (strncmp(refname, "refs/heads/", ofs))
377 return 0;
378 /* If both heads/foo and tags/foo exists, get_sha1 would
379 * get confused.
380 */
381 if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
382 ofs = 5;
383 return append_ref(refname + ofs, sha1);
384}
385
386static int append_tag_ref(const char *refname, const unsigned char *sha1)
387{
388 if (strncmp(refname, "refs/tags/", 10))
389 return 0;
390 return append_ref(refname + 5, sha1);
391}
392
393static const char *match_ref_pattern = NULL;
394static int match_ref_slash = 0;
395static int count_slash(const char *s)
396{
397 int cnt = 0;
398 while (*s)
399 if (*s++ == '/')
400 cnt++;
401 return cnt;
402}
403
404static int append_matching_ref(const char *refname, const unsigned char *sha1)
405{
406 /* we want to allow pattern hold/<asterisk> to show all
407 * branches under refs/heads/hold/, and v0.99.9? to show
408 * refs/tags/v0.99.9a and friends.
409 */
410 const char *tail;
411 int slash = count_slash(refname);
412 for (tail = refname; *tail && match_ref_slash < slash; )
413 if (*tail++ == '/')
414 slash--;
415 if (!*tail)
416 return 0;
417 if (fnmatch(match_ref_pattern, tail, 0))
418 return 0;
419 if (!strncmp("refs/heads/", refname, 11))
420 return append_head_ref(refname, sha1);
421 if (!strncmp("refs/tags/", refname, 10))
422 return append_tag_ref(refname, sha1);
423 return append_ref(refname, sha1);
424}
425
426static void snarf_refs(int head, int tag)
427{
428 if (head) {
429 int orig_cnt = ref_name_cnt;
430 for_each_ref(append_head_ref);
431 sort_ref_range(orig_cnt, ref_name_cnt);
432 }
433 if (tag) {
434 int orig_cnt = ref_name_cnt;
435 for_each_ref(append_tag_ref);
436 sort_ref_range(orig_cnt, ref_name_cnt);
437 }
438}
439
440static int rev_is_head(char *head_path, int headlen, char *name,
441 unsigned char *head_sha1, unsigned char *sha1)
442{
443 int namelen;
444 if ((!head_path[0]) ||
445 (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
446 return 0;
447 namelen = strlen(name);
448 if ((headlen < namelen) ||
449 memcmp(head_path + headlen - namelen, name, namelen))
450 return 0;
451 if (headlen == namelen ||
452 head_path[headlen - namelen - 1] == '/')
453 return 1;
454 return 0;
455}
456
457static int show_merge_base(struct commit_list *seen, int num_rev)
458{
459 int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
460 int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
461 int exit_status = 1;
462
463 while (seen) {
464 struct commit *commit = pop_one_commit(&seen);
465 int flags = commit->object.flags & all_mask;
466 if (!(flags & UNINTERESTING) &&
467 ((flags & all_revs) == all_revs)) {
468 puts(sha1_to_hex(commit->object.sha1));
469 exit_status = 0;
470 commit->object.flags |= UNINTERESTING;
471 }
472 }
473 return exit_status;
474}
475
476static int show_independent(struct commit **rev,
477 int num_rev,
478 char **ref_name,
479 unsigned int *rev_mask)
480{
481 int i;
482
483 for (i = 0; i < num_rev; i++) {
484 struct commit *commit = rev[i];
485 unsigned int flag = rev_mask[i];
486
487 if (commit->object.flags == flag)
488 puts(sha1_to_hex(commit->object.sha1));
489 commit->object.flags |= UNINTERESTING;
490 }
491 return 0;
492}
493
494static void append_one_rev(const char *av)
495{
496 unsigned char revkey[20];
497 if (!get_sha1(av, revkey)) {
498 append_ref(av, revkey);
499 return;
500 }
501 if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
502 /* glob style match */
503 int saved_matches = ref_name_cnt;
504 match_ref_pattern = av;
505 match_ref_slash = count_slash(av);
506 for_each_ref(append_matching_ref);
507 if (saved_matches == ref_name_cnt &&
508 ref_name_cnt < MAX_REVS)
509 error("no matching refs with %s", av);
510 if (saved_matches + 1 < ref_name_cnt)
511 sort_ref_range(saved_matches, ref_name_cnt);
512 return;
513 }
514 die("bad sha1 reference %s", av);
515}
516
517static int git_show_branch_config(const char *var, const char *value)
518{
519 if (!strcmp(var, "showbranch.default")) {
520 if (default_alloc <= default_num + 1) {
521 default_alloc = default_alloc * 3 / 2 + 20;
522 default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
523 }
524 default_arg[default_num++] = strdup(value);
525 default_arg[default_num] = NULL;
526 return 0;
527 }
528
529 return git_default_config(var, value);
530}
531
532static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
533{
534 /* If the commit is tip of the named branches, do not
535 * omit it.
536 * Otherwise, if it is a merge that is reachable from only one
537 * tip, it is not that interesting.
538 */
539 int i, flag, count;
540 for (i = 0; i < n; i++)
541 if (rev[i] == commit)
542 return 0;
543 flag = commit->object.flags;
544 for (i = count = 0; i < n; i++) {
545 if (flag & (1u << (i + REV_SHIFT)))
546 count++;
547 }
548 if (count == 1)
549 return 1;
550 return 0;
551}
552
553int cmd_show_branch(int ac, const char **av, const char *prefix)
554{
555 struct commit *rev[MAX_REVS], *commit;
556 struct commit_list *list = NULL, *seen = NULL;
557 unsigned int rev_mask[MAX_REVS];
558 int num_rev, i, extra = 0;
559 int all_heads = 0, all_tags = 0;
560 int all_mask, all_revs;
561 int lifo = 1;
562 char head_path[128];
563 const char *head_path_p;
564 int head_path_len;
565 unsigned char head_sha1[20];
566 int merge_base = 0;
567 int independent = 0;
568 int no_name = 0;
569 int sha1_name = 0;
570 int shown_merge_point = 0;
571 int with_current_branch = 0;
572 int head_at = -1;
573 int topics = 0;
574 int dense = 1;
575
576 git_config(git_show_branch_config);
577
578 /* If nothing is specified, try the default first */
579 if (ac == 1 && default_num) {
580 ac = default_num + 1;
581 av = default_arg - 1; /* ick; we would not address av[0] */
582 }
583
584 while (1 < ac && av[1][0] == '-') {
585 const char *arg = av[1];
586 if (!strcmp(arg, "--")) {
587 ac--; av++;
588 break;
589 }
590 else if (!strcmp(arg, "--all"))
591 all_heads = all_tags = 1;
592 else if (!strcmp(arg, "--heads"))
593 all_heads = 1;
594 else if (!strcmp(arg, "--tags"))
595 all_tags = 1;
596 else if (!strcmp(arg, "--more"))
597 extra = 1;
598 else if (!strcmp(arg, "--list"))
599 extra = -1;
600 else if (!strcmp(arg, "--no-name"))
601 no_name = 1;
602 else if (!strcmp(arg, "--current"))
603 with_current_branch = 1;
604 else if (!strcmp(arg, "--sha1-name"))
605 sha1_name = 1;
606 else if (!strncmp(arg, "--more=", 7))
607 extra = atoi(arg + 7);
608 else if (!strcmp(arg, "--merge-base"))
609 merge_base = 1;
610 else if (!strcmp(arg, "--independent"))
611 independent = 1;
612 else if (!strcmp(arg, "--topo-order"))
613 lifo = 1;
614 else if (!strcmp(arg, "--topics"))
615 topics = 1;
616 else if (!strcmp(arg, "--sparse"))
617 dense = 0;
618 else if (!strcmp(arg, "--date-order"))
619 lifo = 0;
620 else
621 usage(show_branch_usage);
622 ac--; av++;
623 }
624 ac--; av++;
625
626 /* Only one of these is allowed */
627 if (1 < independent + merge_base + (extra != 0))
628 usage(show_branch_usage);
629
630 /* If nothing is specified, show all branches by default */
631 if (ac + all_heads + all_tags == 0)
632 all_heads = 1;
633
634 if (all_heads + all_tags)
635 snarf_refs(all_heads, all_tags);
636 while (0 < ac) {
637 append_one_rev(*av);
638 ac--; av++;
639 }
640
641 head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
642 if (head_path_p) {
643 head_path_len = strlen(head_path_p);
644 memcpy(head_path, head_path_p, head_path_len + 1);
645 }
646 else {
647 head_path_len = 0;
648 head_path[0] = 0;
649 }
650
651 if (with_current_branch && head_path_p) {
652 int has_head = 0;
653 for (i = 0; !has_head && i < ref_name_cnt; i++) {
654 /* We are only interested in adding the branch
655 * HEAD points at.
656 */
657 if (rev_is_head(head_path,
658 head_path_len,
659 ref_name[i],
660 head_sha1, NULL))
661 has_head++;
662 }
663 if (!has_head) {
664 int pfxlen = strlen(git_path("refs/heads/"));
665 append_one_rev(head_path + pfxlen);
666 }
667 }
668
669 if (!ref_name_cnt) {
670 fprintf(stderr, "No revs to be shown.\n");
671 exit(0);
672 }
673
674 for (num_rev = 0; ref_name[num_rev]; num_rev++) {
675 unsigned char revkey[20];
676 unsigned int flag = 1u << (num_rev + REV_SHIFT);
677
678 if (MAX_REVS <= num_rev)
679 die("cannot handle more than %d revs.", MAX_REVS);
680 if (get_sha1(ref_name[num_rev], revkey))
681 die("'%s' is not a valid ref.", ref_name[num_rev]);
682 commit = lookup_commit_reference(revkey);
683 if (!commit)
684 die("cannot find commit %s (%s)",
685 ref_name[num_rev], revkey);
686 parse_commit(commit);
687 mark_seen(commit, &seen);
688
689 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
690 * and so on. REV_SHIFT bits from bit 0 are used for
691 * internal bookkeeping.
692 */
693 commit->object.flags |= flag;
694 if (commit->object.flags == flag)
695 insert_by_date(commit, &list);
696 rev[num_rev] = commit;
697 }
698 for (i = 0; i < num_rev; i++)
699 rev_mask[i] = rev[i]->object.flags;
700
701 if (0 <= extra)
702 join_revs(&list, &seen, num_rev, extra);
703
704 sort_by_date(&seen);
705
706 if (merge_base)
707 return show_merge_base(seen, num_rev);
708
709 if (independent)
710 return show_independent(rev, num_rev, ref_name, rev_mask);
711
712 /* Show list; --more=-1 means list-only */
713 if (1 < num_rev || extra < 0) {
714 for (i = 0; i < num_rev; i++) {
715 int j;
716 int is_head = rev_is_head(head_path,
717 head_path_len,
718 ref_name[i],
719 head_sha1,
720 rev[i]->object.sha1);
721 if (extra < 0)
722 printf("%c [%s] ",
723 is_head ? '*' : ' ', ref_name[i]);
724 else {
725 for (j = 0; j < i; j++)
726 putchar(' ');
727 printf("%c [%s] ",
728 is_head ? '*' : '!', ref_name[i]);
729 }
730 /* header lines never need name */
731 show_one_commit(rev[i], 1);
732 if (is_head)
733 head_at = i;
734 }
735 if (0 <= extra) {
736 for (i = 0; i < num_rev; i++)
737 putchar('-');
738 putchar('\n');
739 }
740 }
741 if (extra < 0)
742 exit(0);
743
744 /* Sort topologically */
745 sort_in_topological_order(&seen, lifo);
746
747 /* Give names to commits */
748 if (!sha1_name && !no_name)
749 name_commits(seen, rev, ref_name, num_rev);
750
751 all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
752 all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
753
754 while (seen) {
755 struct commit *commit = pop_one_commit(&seen);
756 int this_flag = commit->object.flags;
757 int is_merge_point = ((this_flag & all_revs) == all_revs);
758
759 shown_merge_point |= is_merge_point;
760
761 if (1 < num_rev) {
762 int is_merge = !!(commit->parents &&
763 commit->parents->next);
764 if (topics &&
765 !is_merge_point &&
766 (this_flag & (1u << REV_SHIFT)))
767 continue;
768 if (dense && is_merge &&
769 omit_in_dense(commit, rev, num_rev))
770 continue;
771 for (i = 0; i < num_rev; i++) {
772 int mark;
773 if (!(this_flag & (1u << (i + REV_SHIFT))))
774 mark = ' ';
775 else if (is_merge)
776 mark = '-';
777 else if (i == head_at)
778 mark = '*';
779 else
780 mark = '+';
781 putchar(mark);
782 }
783 putchar(' ');
784 }
785 show_one_commit(commit, no_name);
786
787 if (shown_merge_point && --extra < 0)
788 break;
789 }
790 return 0;
791}