1#include "cache.h"
2#include "tag.h"
3#include "commit.h"
4#include "pkt-line.h"
5#include "utf8.h"
6#include "diff.h"
7#include "revision.h"
8#include "notes.h"
9int save_commit_buffer = 1;
11const char *commit_type = "commit";
13static struct commit *check_commit(struct object *obj,
15 const unsigned char *sha1,
16 int quiet)
17{
18 if (obj->type != OBJ_COMMIT) {
19 if (!quiet)
20 error("Object %s is a %s, not a commit",
21 sha1_to_hex(sha1), typename(obj->type));
22 return NULL;
23 }
24 return (struct commit *) obj;
25}
26struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
28 int quiet)
29{
30 struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
31 if (!obj)
33 return NULL;
34 return check_commit(obj, sha1, quiet);
35}
36struct commit *lookup_commit_reference(const unsigned char *sha1)
38{
39 return lookup_commit_reference_gently(sha1, 0);
40}
41struct commit *lookup_commit(const unsigned char *sha1)
43{
44 struct object *obj = lookup_object(sha1);
45 if (!obj)
46 return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
47 if (!obj->type)
48 obj->type = OBJ_COMMIT;
49 return check_commit(obj, sha1, 0);
50}
51static unsigned long parse_commit_date(const char *buf, const char *tail)
53{
54 const char *dateptr;
55 if (buf + 6 >= tail)
57 return 0;
58 if (memcmp(buf, "author", 6))
59 return 0;
60 while (buf < tail && *buf++ != '\n')
61 /* nada */;
62 if (buf + 9 >= tail)
63 return 0;
64 if (memcmp(buf, "committer", 9))
65 return 0;
66 while (buf < tail && *buf++ != '>')
67 /* nada */;
68 if (buf >= tail)
69 return 0;
70 dateptr = buf;
71 while (buf < tail && *buf++ != '\n')
72 /* nada */;
73 if (buf >= tail)
74 return 0;
75 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
76 return strtoul(dateptr, NULL, 10);
77}
78static struct commit_graft **commit_graft;
80static int commit_graft_alloc, commit_graft_nr;
81static int commit_graft_pos(const unsigned char *sha1)
83{
84 int lo, hi;
85 lo = 0;
86 hi = commit_graft_nr;
87 while (lo < hi) {
88 int mi = (lo + hi) / 2;
89 struct commit_graft *graft = commit_graft[mi];
90 int cmp = hashcmp(sha1, graft->sha1);
91 if (!cmp)
92 return mi;
93 if (cmp < 0)
94 hi = mi;
95 else
96 lo = mi + 1;
97 }
98 return -lo - 1;
99}
100int register_commit_graft(struct commit_graft *graft, int ignore_dups)
102{
103 int pos = commit_graft_pos(graft->sha1);
104 if (0 <= pos) {
106 if (ignore_dups)
107 free(graft);
108 else {
109 free(commit_graft[pos]);
110 commit_graft[pos] = graft;
111 }
112 return 1;
113 }
114 pos = -pos - 1;
115 if (commit_graft_alloc <= ++commit_graft_nr) {
116 commit_graft_alloc = alloc_nr(commit_graft_alloc);
117 commit_graft = xrealloc(commit_graft,
118 sizeof(*commit_graft) *
119 commit_graft_alloc);
120 }
121 if (pos < commit_graft_nr)
122 memmove(commit_graft + pos + 1,
123 commit_graft + pos,
124 (commit_graft_nr - pos - 1) *
125 sizeof(*commit_graft));
126 commit_graft[pos] = graft;
127 return 0;
128}
129struct commit_graft *read_graft_line(char *buf, int len)
131{
132 /* The format is just "Commit Parent1 Parent2 ...\n" */
133 int i;
134 struct commit_graft *graft = NULL;
135 while (len && isspace(buf[len-1]))
137 buf[--len] = '\0';
138 if (buf[0] == '#' || buf[0] == '\0')
139 return NULL;
140 if ((len + 1) % 41) {
141 bad_graft_data:
142 error("bad graft data: %s", buf);
143 free(graft);
144 return NULL;
145 }
146 i = (len + 1) / 41 - 1;
147 graft = xmalloc(sizeof(*graft) + 20 * i);
148 graft->nr_parent = i;
149 if (get_sha1_hex(buf, graft->sha1))
150 goto bad_graft_data;
151 for (i = 40; i < len; i += 41) {
152 if (buf[i] != ' ')
153 goto bad_graft_data;
154 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
155 goto bad_graft_data;
156 }
157 return graft;
158}
159static int read_graft_file(const char *graft_file)
161{
162 FILE *fp = fopen(graft_file, "r");
163 char buf[1024];
164 if (!fp)
165 return -1;
166 while (fgets(buf, sizeof(buf), fp)) {
167 /* The format is just "Commit Parent1 Parent2 ...\n" */
168 int len = strlen(buf);
169 struct commit_graft *graft = read_graft_line(buf, len);
170 if (!graft)
171 continue;
172 if (register_commit_graft(graft, 1))
173 error("duplicate graft data: %s", buf);
174 }
175 fclose(fp);
176 return 0;
177}
178static void prepare_commit_graft(void)
180{
181 static int commit_graft_prepared;
182 char *graft_file;
183 if (commit_graft_prepared)
185 return;
186 graft_file = get_graft_file();
187 read_graft_file(graft_file);
188 /* make sure shallows are read */
189 is_repository_shallow();
190 commit_graft_prepared = 1;
191}
192struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
194{
195 int pos;
196 prepare_commit_graft();
197 pos = commit_graft_pos(sha1);
198 if (pos < 0)
199 return NULL;
200 return commit_graft[pos];
201}
202int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
204{
205 int i, count = 0;
206 for (i = 0; i < commit_graft_nr; i++)
207 if (commit_graft[i]->nr_parent < 0) {
208 const char *hex =
209 sha1_to_hex(commit_graft[i]->sha1);
210 count++;
211 if (use_pack_protocol)
212 packet_buf_write(out, "shallow %s", hex);
213 else {
214 strbuf_addstr(out, hex);
215 strbuf_addch(out, '\n');
216 }
217 }
218 return count;
219}
220int unregister_shallow(const unsigned char *sha1)
222{
223 int pos = commit_graft_pos(sha1);
224 if (pos < 0)
225 return -1;
226 if (pos + 1 < commit_graft_nr)
227 memcpy(commit_graft + pos, commit_graft + pos + 1,
228 sizeof(struct commit_graft *)
229 * (commit_graft_nr - pos - 1));
230 commit_graft_nr--;
231 return 0;
232}
233int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
235{
236 char *tail = buffer;
237 char *bufptr = buffer;
238 unsigned char parent[20];
239 struct commit_list **pptr;
240 struct commit_graft *graft;
241 if (item->object.parsed)
243 return 0;
244 item->object.parsed = 1;
245 tail += size;
246 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
247 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
248 if (get_sha1_hex(bufptr + 5, parent) < 0)
249 return error("bad tree pointer in commit %s",
250 sha1_to_hex(item->object.sha1));
251 item->tree = lookup_tree(parent);
252 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
253 pptr = &item->parents;
254 graft = lookup_commit_graft(item->object.sha1);
256 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
257 struct commit *new_parent;
258 if (tail <= bufptr + 48 ||
260 get_sha1_hex(bufptr + 7, parent) ||
261 bufptr[47] != '\n')
262 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
263 bufptr += 48;
264 /*
265 * The clone is shallow if nr_parent < 0, and we must
266 * not traverse its real parents even when we unhide them.
267 */
268 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
269 continue;
270 new_parent = lookup_commit(parent);
271 if (new_parent)
272 pptr = &commit_list_insert(new_parent, pptr)->next;
273 }
274 if (graft) {
275 int i;
276 struct commit *new_parent;
277 for (i = 0; i < graft->nr_parent; i++) {
278 new_parent = lookup_commit(graft->parent[i]);
279 if (!new_parent)
280 continue;
281 pptr = &commit_list_insert(new_parent, pptr)->next;
282 }
283 }
284 item->date = parse_commit_date(bufptr, tail);
285 return 0;
287}
288int parse_commit(struct commit *item)
290{
291 enum object_type type;
292 void *buffer;
293 unsigned long size;
294 int ret;
295 if (!item)
297 return -1;
298 if (item->object.parsed)
299 return 0;
300 buffer = read_sha1_file(item->object.sha1, &type, &size);
301 if (!buffer)
302 return error("Could not read %s",
303 sha1_to_hex(item->object.sha1));
304 if (type != OBJ_COMMIT) {
305 free(buffer);
306 return error("Object %s not a commit",
307 sha1_to_hex(item->object.sha1));
308 }
309 ret = parse_commit_buffer(item, buffer, size);
310 if (save_commit_buffer && !ret) {
311 item->buffer = buffer;
312 return 0;
313 }
314 free(buffer);
315 return ret;
316}
317struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
319{
320 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
321 new_list->item = item;
322 new_list->next = *list_p;
323 *list_p = new_list;
324 return new_list;
325}
326unsigned commit_list_count(const struct commit_list *l)
328{
329 unsigned c = 0;
330 for (; l; l = l->next )
331 c++;
332 return c;
333}
334void free_commit_list(struct commit_list *list)
336{
337 while (list) {
338 struct commit_list *temp = list;
339 list = temp->next;
340 free(temp);
341 }
342}
343struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
345{
346 struct commit_list **pp = list;
347 struct commit_list *p;
348 while ((p = *pp) != NULL) {
349 if (p->item->date < item->date) {
350 break;
351 }
352 pp = &p->next;
353 }
354 return commit_list_insert(item, pp);
355}
356void sort_by_date(struct commit_list **list)
359{
360 struct commit_list *ret = NULL;
361 while (*list) {
362 insert_by_date((*list)->item, &ret);
363 *list = (*list)->next;
364 }
365 *list = ret;
366}
367struct commit *pop_most_recent_commit(struct commit_list **list,
369 unsigned int mark)
370{
371 struct commit *ret = (*list)->item;
372 struct commit_list *parents = ret->parents;
373 struct commit_list *old = *list;
374 *list = (*list)->next;
376 free(old);
377 while (parents) {
379 struct commit *commit = parents->item;
380 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
381 commit->object.flags |= mark;
382 insert_by_date(commit, list);
383 }
384 parents = parents->next;
385 }
386 return ret;
387}
388void clear_commit_marks(struct commit *commit, unsigned int mark)
390{
391 while (commit) {
392 struct commit_list *parents;
393 if (!(mark & commit->object.flags))
395 return;
396 commit->object.flags &= ~mark;
398 parents = commit->parents;
400 if (!parents)
401 return;
402 while ((parents = parents->next))
404 clear_commit_marks(parents->item, mark);
405 commit = commit->parents->item;
407 }
408}
409struct commit *pop_commit(struct commit_list **stack)
411{
412 struct commit_list *top = *stack;
413 struct commit *item = top ? top->item : NULL;
414 if (top) {
416 *stack = top->next;
417 free(top);
418 }
419 return item;
420}
421/*
423 * Performs an in-place topological sort on the list supplied.
424 */
425void sort_in_topological_order(struct commit_list ** list, int lifo)
426{
427 struct commit_list *next, *orig = *list;
428 struct commit_list *work, **insert;
429 struct commit_list **pptr;
430 if (!orig)
432 return;
433 *list = NULL;
434 /* Mark them and clear the indegree */
436 for (next = orig; next; next = next->next) {
437 struct commit *commit = next->item;
438 commit->indegree = 1;
439 }
440 /* update the indegree */
442 for (next = orig; next; next = next->next) {
443 struct commit_list * parents = next->item->parents;
444 while (parents) {
445 struct commit *parent = parents->item;
446 if (parent->indegree)
448 parent->indegree++;
449 parents = parents->next;
450 }
451 }
452 /*
454 * find the tips
455 *
456 * tips are nodes not reachable from any other node in the list
457 *
458 * the tips serve as a starting set for the work queue.
459 */
460 work = NULL;
461 insert = &work;
462 for (next = orig; next; next = next->next) {
463 struct commit *commit = next->item;
464 if (commit->indegree == 1)
466 insert = &commit_list_insert(commit, insert)->next;
467 }
468 /* process the list in topological order */
470 if (!lifo)
471 sort_by_date(&work);
472 pptr = list;
474 *list = NULL;
475 while (work) {
476 struct commit *commit;
477 struct commit_list *parents, *work_item;
478 work_item = work;
480 work = work_item->next;
481 work_item->next = NULL;
482 commit = work_item->item;
484 for (parents = commit->parents; parents ; parents = parents->next) {
485 struct commit *parent=parents->item;
486 if (!parent->indegree)
488 continue;
489 /*
491 * parents are only enqueued for emission
492 * when all their children have been emitted thereby
493 * guaranteeing topological order.
494 */
495 if (--parent->indegree == 1) {
496 if (!lifo)
497 insert_by_date(parent, &work);
498 else
499 commit_list_insert(parent, &work);
500 }
501 }
502 /*
503 * work_item is a commit all of whose children
504 * have already been emitted. we can emit it now.
505 */
506 commit->indegree = 0;
507 *pptr = work_item;
508 pptr = &work_item->next;
509 }
510}
511/* merge-base stuff */
513/* bits #0..15 in revision.h */
515#define PARENT1 (1u<<16)
516#define PARENT2 (1u<<17)
517#define STALE (1u<<18)
518#define RESULT (1u<<19)
519static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
521static struct commit *interesting(struct commit_list *list)
523{
524 while (list) {
525 struct commit *commit = list->item;
526 list = list->next;
527 if (commit->object.flags & STALE)
528 continue;
529 return commit;
530 }
531 return NULL;
532}
533static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
535{
536 struct commit_list *list = NULL;
537 struct commit_list *result = NULL;
538 int i;
539 for (i = 0; i < n; i++) {
541 if (one == twos[i])
542 /*
543 * We do not mark this even with RESULT so we do not
544 * have to clean it up.
545 */
546 return commit_list_insert(one, &result);
547 }
548 if (parse_commit(one))
550 return NULL;
551 for (i = 0; i < n; i++) {
552 if (parse_commit(twos[i]))
553 return NULL;
554 }
555 one->object.flags |= PARENT1;
557 insert_by_date(one, &list);
558 for (i = 0; i < n; i++) {
559 twos[i]->object.flags |= PARENT2;
560 insert_by_date(twos[i], &list);
561 }
562 while (interesting(list)) {
564 struct commit *commit;
565 struct commit_list *parents;
566 struct commit_list *next;
567 int flags;
568 commit = list->item;
570 next = list->next;
571 free(list);
572 list = next;
573 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
575 if (flags == (PARENT1 | PARENT2)) {
576 if (!(commit->object.flags & RESULT)) {
577 commit->object.flags |= RESULT;
578 insert_by_date(commit, &result);
579 }
580 /* Mark parents of a found merge stale */
581 flags |= STALE;
582 }
583 parents = commit->parents;
584 while (parents) {
585 struct commit *p = parents->item;
586 parents = parents->next;
587 if ((p->object.flags & flags) == flags)
588 continue;
589 if (parse_commit(p))
590 return NULL;
591 p->object.flags |= flags;
592 insert_by_date(p, &list);
593 }
594 }
595 /* Clean up the result to remove stale ones */
597 free_commit_list(list);
598 list = result; result = NULL;
599 while (list) {
600 struct commit_list *next = list->next;
601 if (!(list->item->object.flags & STALE))
602 insert_by_date(list->item, &result);
603 free(list);
604 list = next;
605 }
606 return result;
607}
608struct commit_list *get_octopus_merge_bases(struct commit_list *in)
610{
611 struct commit_list *i, *j, *k, *ret = NULL;
612 struct commit_list **pptr = &ret;
613 for (i = in; i; i = i->next) {
615 if (!ret)
616 pptr = &commit_list_insert(i->item, pptr)->next;
617 else {
618 struct commit_list *new = NULL, *end = NULL;
619 for (j = ret; j; j = j->next) {
621 struct commit_list *bases;
622 bases = get_merge_bases(i->item, j->item, 1);
623 if (!new)
624 new = bases;
625 else
626 end->next = bases;
627 for (k = bases; k; k = k->next)
628 end = k;
629 }
630 ret = new;
631 }
632 }
633 return ret;
634}
635struct commit_list *get_merge_bases_many(struct commit *one,
637 int n,
638 struct commit **twos,
639 int cleanup)
640{
641 struct commit_list *list;
642 struct commit **rslt;
643 struct commit_list *result;
644 int cnt, i, j;
645 result = merge_bases_many(one, n, twos);
647 for (i = 0; i < n; i++) {
648 if (one == twos[i])
649 return result;
650 }
651 if (!result || !result->next) {
652 if (cleanup) {
653 clear_commit_marks(one, all_flags);
654 for (i = 0; i < n; i++)
655 clear_commit_marks(twos[i], all_flags);
656 }
657 return result;
658 }
659 /* There are more than one */
661 cnt = 0;
662 list = result;
663 while (list) {
664 list = list->next;
665 cnt++;
666 }
667 rslt = xcalloc(cnt, sizeof(*rslt));
668 for (list = result, i = 0; list; list = list->next)
669 rslt[i++] = list->item;
670 free_commit_list(result);
671 clear_commit_marks(one, all_flags);
673 for (i = 0; i < n; i++)
674 clear_commit_marks(twos[i], all_flags);
675 for (i = 0; i < cnt - 1; i++) {
676 for (j = i+1; j < cnt; j++) {
677 if (!rslt[i] || !rslt[j])
678 continue;
679 result = merge_bases_many(rslt[i], 1, &rslt[j]);
680 clear_commit_marks(rslt[i], all_flags);
681 clear_commit_marks(rslt[j], all_flags);
682 for (list = result; list; list = list->next) {
683 if (rslt[i] == list->item)
684 rslt[i] = NULL;
685 if (rslt[j] == list->item)
686 rslt[j] = NULL;
687 }
688 }
689 }
690 /* Surviving ones in rslt[] are the independent results */
692 result = NULL;
693 for (i = 0; i < cnt; i++) {
694 if (rslt[i])
695 insert_by_date(rslt[i], &result);
696 }
697 free(rslt);
698 return result;
699}
700struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
702 int cleanup)
703{
704 return get_merge_bases_many(one, 1, &two, cleanup);
705}
706int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
708{
709 if (!with_commit)
710 return 1;
711 while (with_commit) {
712 struct commit *other;
713 other = with_commit->item;
715 with_commit = with_commit->next;
716 if (in_merge_bases(other, &commit, 1))
717 return 1;
718 }
719 return 0;
720}
721int in_merge_bases(struct commit *commit, struct commit **reference, int num)
723{
724 struct commit_list *bases, *b;
725 int ret = 0;
726 if (num == 1)
728 bases = get_merge_bases(commit, *reference, 1);
729 else
730 die("not yet");
731 for (b = bases; b; b = b->next) {
732 if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
733 ret = 1;
734 break;
735 }
736 }
737 free_commit_list(bases);
739 return ret;
740}
741struct commit_list *reduce_heads(struct commit_list *heads)
743{
744 struct commit_list *p;
745 struct commit_list *result = NULL, **tail = &result;
746 struct commit **other;
747 size_t num_head, num_other;
748 if (!heads)
750 return NULL;
751 /* Avoid unnecessary reallocations */
753 for (p = heads, num_head = 0; p; p = p->next)
754 num_head++;
755 other = xcalloc(sizeof(*other), num_head);
756 /* For each commit, see if it can be reached by others */
758 for (p = heads; p; p = p->next) {
759 struct commit_list *q, *base;
760 /* Do we already have this in the result? */
762 for (q = result; q; q = q->next)
763 if (p->item == q->item)
764 break;
765 if (q)
766 continue;
767 num_other = 0;
769 for (q = heads; q; q = q->next) {
770 if (p->item == q->item)
771 continue;
772 other[num_other++] = q->item;
773 }
774 if (num_other)
775 base = get_merge_bases_many(p->item, num_other, other, 1);
776 else
777 base = NULL;
778 /*
779 * If p->item does not have anything common with other
780 * commits, there won't be any merge base. If it is
781 * reachable from some of the others, p->item will be
782 * the merge base. If its history is connected with
783 * others, but p->item is not reachable by others, we
784 * will get something other than p->item back.
785 */
786 if (!base || (base->item != p->item))
787 tail = &(commit_list_insert(p->item, tail)->next);
788 free_commit_list(base);
789 }
790 free(other);
791 return result;
792}