Documentation/describe: improve one-line summary
[git.git] / commit.c
blob19cf8f9c67bd0f4d71172f33424f7d2371a3af68
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"
9 #include "gpg-interface.h"
10 #include "mergesort.h"
11 #include "commit-slab.h"
12 #include "prio-queue.h"
13 #include "sha1-lookup.h"
15 static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
17 int save_commit_buffer = 1;
19 const char *commit_type = "commit";
21 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
22 int quiet)
24 struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
26 if (!obj)
27 return NULL;
28 return object_as_type(obj, OBJ_COMMIT, quiet);
31 struct commit *lookup_commit_reference(const unsigned char *sha1)
33 return lookup_commit_reference_gently(sha1, 0);
36 struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
38 struct commit *c = lookup_commit_reference(sha1);
39 if (!c)
40 die(_("could not parse %s"), ref_name);
41 if (hashcmp(sha1, c->object.sha1)) {
42 warning(_("%s %s is not a commit!"),
43 ref_name, sha1_to_hex(sha1));
45 return c;
48 struct commit *lookup_commit(const unsigned char *sha1)
50 struct object *obj = lookup_object(sha1);
51 if (!obj)
52 return create_object(sha1, alloc_commit_node());
53 return object_as_type(obj, OBJ_COMMIT, 0);
56 struct commit *lookup_commit_reference_by_name(const char *name)
58 unsigned char sha1[20];
59 struct commit *commit;
61 if (get_sha1_committish(name, sha1))
62 return NULL;
63 commit = lookup_commit_reference(sha1);
64 if (parse_commit(commit))
65 return NULL;
66 return commit;
69 static unsigned long parse_commit_date(const char *buf, const char *tail)
71 const char *dateptr;
73 if (buf + 6 >= tail)
74 return 0;
75 if (memcmp(buf, "author", 6))
76 return 0;
77 while (buf < tail && *buf++ != '\n')
78 /* nada */;
79 if (buf + 9 >= tail)
80 return 0;
81 if (memcmp(buf, "committer", 9))
82 return 0;
83 while (buf < tail && *buf++ != '>')
84 /* nada */;
85 if (buf >= tail)
86 return 0;
87 dateptr = buf;
88 while (buf < tail && *buf++ != '\n')
89 /* nada */;
90 if (buf >= tail)
91 return 0;
92 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
93 return strtoul(dateptr, NULL, 10);
96 static struct commit_graft **commit_graft;
97 static int commit_graft_alloc, commit_graft_nr;
99 static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
101 struct commit_graft **commit_graft_table = table;
102 return commit_graft_table[index]->sha1;
105 static int commit_graft_pos(const unsigned char *sha1)
107 return sha1_pos(sha1, commit_graft, commit_graft_nr,
108 commit_graft_sha1_access);
111 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
113 int pos = commit_graft_pos(graft->sha1);
115 if (0 <= pos) {
116 if (ignore_dups)
117 free(graft);
118 else {
119 free(commit_graft[pos]);
120 commit_graft[pos] = graft;
122 return 1;
124 pos = -pos - 1;
125 ALLOC_GROW(commit_graft, commit_graft_nr + 1, commit_graft_alloc);
126 commit_graft_nr++;
127 if (pos < commit_graft_nr)
128 memmove(commit_graft + pos + 1,
129 commit_graft + pos,
130 (commit_graft_nr - pos - 1) *
131 sizeof(*commit_graft));
132 commit_graft[pos] = graft;
133 return 0;
136 struct commit_graft *read_graft_line(char *buf, int len)
138 /* The format is just "Commit Parent1 Parent2 ...\n" */
139 int i;
140 struct commit_graft *graft = NULL;
142 while (len && isspace(buf[len-1]))
143 buf[--len] = '\0';
144 if (buf[0] == '#' || buf[0] == '\0')
145 return NULL;
146 if ((len + 1) % 41)
147 goto bad_graft_data;
148 i = (len + 1) / 41 - 1;
149 graft = xmalloc(sizeof(*graft) + 20 * i);
150 graft->nr_parent = i;
151 if (get_sha1_hex(buf, graft->sha1))
152 goto bad_graft_data;
153 for (i = 40; i < len; i += 41) {
154 if (buf[i] != ' ')
155 goto bad_graft_data;
156 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
157 goto bad_graft_data;
159 return graft;
161 bad_graft_data:
162 error("bad graft data: %s", buf);
163 free(graft);
164 return NULL;
167 static int read_graft_file(const char *graft_file)
169 FILE *fp = fopen(graft_file, "r");
170 struct strbuf buf = STRBUF_INIT;
171 if (!fp)
172 return -1;
173 while (!strbuf_getwholeline(&buf, fp, '\n')) {
174 /* The format is just "Commit Parent1 Parent2 ...\n" */
175 struct commit_graft *graft = read_graft_line(buf.buf, buf.len);
176 if (!graft)
177 continue;
178 if (register_commit_graft(graft, 1))
179 error("duplicate graft data: %s", buf.buf);
181 fclose(fp);
182 strbuf_release(&buf);
183 return 0;
186 static void prepare_commit_graft(void)
188 static int commit_graft_prepared;
189 char *graft_file;
191 if (commit_graft_prepared)
192 return;
193 graft_file = get_graft_file();
194 read_graft_file(graft_file);
195 /* make sure shallows are read */
196 is_repository_shallow();
197 commit_graft_prepared = 1;
200 struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
202 int pos;
203 prepare_commit_graft();
204 pos = commit_graft_pos(sha1);
205 if (pos < 0)
206 return NULL;
207 return commit_graft[pos];
210 int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
212 int i, ret;
213 for (i = ret = 0; i < commit_graft_nr && !ret; i++)
214 ret = fn(commit_graft[i], cb_data);
215 return ret;
218 int unregister_shallow(const unsigned char *sha1)
220 int pos = commit_graft_pos(sha1);
221 if (pos < 0)
222 return -1;
223 if (pos + 1 < commit_graft_nr)
224 memmove(commit_graft + pos, commit_graft + pos + 1,
225 sizeof(struct commit_graft *)
226 * (commit_graft_nr - pos - 1));
227 commit_graft_nr--;
228 return 0;
231 struct commit_buffer {
232 void *buffer;
233 unsigned long size;
235 define_commit_slab(buffer_slab, struct commit_buffer);
236 static struct buffer_slab buffer_slab = COMMIT_SLAB_INIT(1, buffer_slab);
238 void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
240 struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
241 v->buffer = buffer;
242 v->size = size;
245 const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
247 struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
248 if (sizep)
249 *sizep = v->size;
250 return v->buffer;
253 const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
255 const void *ret = get_cached_commit_buffer(commit, sizep);
256 if (!ret) {
257 enum object_type type;
258 unsigned long size;
259 ret = read_sha1_file(commit->object.sha1, &type, &size);
260 if (!ret)
261 die("cannot read commit object %s",
262 sha1_to_hex(commit->object.sha1));
263 if (type != OBJ_COMMIT)
264 die("expected commit for %s, got %s",
265 sha1_to_hex(commit->object.sha1), typename(type));
266 if (sizep)
267 *sizep = size;
269 return ret;
272 void unuse_commit_buffer(const struct commit *commit, const void *buffer)
274 struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
275 if (v->buffer != buffer)
276 free((void *)buffer);
279 void free_commit_buffer(struct commit *commit)
281 struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
282 free(v->buffer);
283 v->buffer = NULL;
284 v->size = 0;
287 const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
289 struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
290 void *ret;
292 ret = v->buffer;
293 if (sizep)
294 *sizep = v->size;
296 v->buffer = NULL;
297 v->size = 0;
298 return ret;
301 int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
303 const char *tail = buffer;
304 const char *bufptr = buffer;
305 unsigned char parent[20];
306 struct commit_list **pptr;
307 struct commit_graft *graft;
309 if (item->object.parsed)
310 return 0;
311 item->object.parsed = 1;
312 tail += size;
313 if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
314 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
315 if (get_sha1_hex(bufptr + 5, parent) < 0)
316 return error("bad tree pointer in commit %s",
317 sha1_to_hex(item->object.sha1));
318 item->tree = lookup_tree(parent);
319 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
320 pptr = &item->parents;
322 graft = lookup_commit_graft(item->object.sha1);
323 while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
324 struct commit *new_parent;
326 if (tail <= bufptr + 48 ||
327 get_sha1_hex(bufptr + 7, parent) ||
328 bufptr[47] != '\n')
329 return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
330 bufptr += 48;
332 * The clone is shallow if nr_parent < 0, and we must
333 * not traverse its real parents even when we unhide them.
335 if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
336 continue;
337 new_parent = lookup_commit(parent);
338 if (new_parent)
339 pptr = &commit_list_insert(new_parent, pptr)->next;
341 if (graft) {
342 int i;
343 struct commit *new_parent;
344 for (i = 0; i < graft->nr_parent; i++) {
345 new_parent = lookup_commit(graft->parent[i]);
346 if (!new_parent)
347 continue;
348 pptr = &commit_list_insert(new_parent, pptr)->next;
351 item->date = parse_commit_date(bufptr, tail);
353 return 0;
356 int parse_commit(struct commit *item)
358 enum object_type type;
359 void *buffer;
360 unsigned long size;
361 int ret;
363 if (!item)
364 return -1;
365 if (item->object.parsed)
366 return 0;
367 buffer = read_sha1_file(item->object.sha1, &type, &size);
368 if (!buffer)
369 return error("Could not read %s",
370 sha1_to_hex(item->object.sha1));
371 if (type != OBJ_COMMIT) {
372 free(buffer);
373 return error("Object %s not a commit",
374 sha1_to_hex(item->object.sha1));
376 ret = parse_commit_buffer(item, buffer, size);
377 if (save_commit_buffer && !ret) {
378 set_commit_buffer(item, buffer, size);
379 return 0;
381 free(buffer);
382 return ret;
385 void parse_commit_or_die(struct commit *item)
387 if (parse_commit(item))
388 die("unable to parse commit %s",
389 item ? sha1_to_hex(item->object.sha1) : "(null)");
392 int find_commit_subject(const char *commit_buffer, const char **subject)
394 const char *eol;
395 const char *p = commit_buffer;
397 while (*p && (*p != '\n' || p[1] != '\n'))
398 p++;
399 if (*p) {
400 p += 2;
401 for (eol = p; *eol && *eol != '\n'; eol++)
402 ; /* do nothing */
403 } else
404 eol = p;
406 *subject = p;
408 return eol - p;
411 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
413 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
414 new_list->item = item;
415 new_list->next = *list_p;
416 *list_p = new_list;
417 return new_list;
420 unsigned commit_list_count(const struct commit_list *l)
422 unsigned c = 0;
423 for (; l; l = l->next )
424 c++;
425 return c;
428 struct commit_list *copy_commit_list(struct commit_list *list)
430 struct commit_list *head = NULL;
431 struct commit_list **pp = &head;
432 while (list) {
433 pp = commit_list_append(list->item, pp);
434 list = list->next;
436 return head;
439 void free_commit_list(struct commit_list *list)
441 while (list) {
442 struct commit_list *temp = list;
443 list = temp->next;
444 free(temp);
448 struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
450 struct commit_list **pp = list;
451 struct commit_list *p;
452 while ((p = *pp) != NULL) {
453 if (p->item->date < item->date) {
454 break;
456 pp = &p->next;
458 return commit_list_insert(item, pp);
461 static int commit_list_compare_by_date(const void *a, const void *b)
463 unsigned long a_date = ((const struct commit_list *)a)->item->date;
464 unsigned long b_date = ((const struct commit_list *)b)->item->date;
465 if (a_date < b_date)
466 return 1;
467 if (a_date > b_date)
468 return -1;
469 return 0;
472 static void *commit_list_get_next(const void *a)
474 return ((const struct commit_list *)a)->next;
477 static void commit_list_set_next(void *a, void *next)
479 ((struct commit_list *)a)->next = next;
482 void commit_list_sort_by_date(struct commit_list **list)
484 *list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
485 commit_list_compare_by_date);
488 struct commit *pop_most_recent_commit(struct commit_list **list,
489 unsigned int mark)
491 struct commit *ret = (*list)->item;
492 struct commit_list *parents = ret->parents;
493 struct commit_list *old = *list;
495 *list = (*list)->next;
496 free(old);
498 while (parents) {
499 struct commit *commit = parents->item;
500 if (!parse_commit(commit) && !(commit->object.flags & mark)) {
501 commit->object.flags |= mark;
502 commit_list_insert_by_date(commit, list);
504 parents = parents->next;
506 return ret;
509 static void clear_commit_marks_1(struct commit_list **plist,
510 struct commit *commit, unsigned int mark)
512 while (commit) {
513 struct commit_list *parents;
515 if (!(mark & commit->object.flags))
516 return;
518 commit->object.flags &= ~mark;
520 parents = commit->parents;
521 if (!parents)
522 return;
524 while ((parents = parents->next))
525 commit_list_insert(parents->item, plist);
527 commit = commit->parents->item;
531 void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
533 struct commit_list *list = NULL;
535 while (nr--) {
536 commit_list_insert(*commit, &list);
537 commit++;
539 while (list)
540 clear_commit_marks_1(&list, pop_commit(&list), mark);
543 void clear_commit_marks(struct commit *commit, unsigned int mark)
545 clear_commit_marks_many(1, &commit, mark);
548 void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
550 struct object *object;
551 struct commit *commit;
552 unsigned int i;
554 for (i = 0; i < a->nr; i++) {
555 object = a->objects[i].item;
556 commit = lookup_commit_reference_gently(object->sha1, 1);
557 if (commit)
558 clear_commit_marks(commit, mark);
562 struct commit *pop_commit(struct commit_list **stack)
564 struct commit_list *top = *stack;
565 struct commit *item = top ? top->item : NULL;
567 if (top) {
568 *stack = top->next;
569 free(top);
571 return item;
575 * Topological sort support
578 /* count number of children that have not been emitted */
579 define_commit_slab(indegree_slab, int);
581 /* record author-date for each commit object */
582 define_commit_slab(author_date_slab, unsigned long);
584 static void record_author_date(struct author_date_slab *author_date,
585 struct commit *commit)
587 const char *buffer = get_commit_buffer(commit, NULL);
588 struct ident_split ident;
589 const char *ident_line;
590 size_t ident_len;
591 char *date_end;
592 unsigned long date;
594 ident_line = find_commit_header(buffer, "author", &ident_len);
595 if (!ident_line)
596 goto fail_exit; /* no author line */
597 if (split_ident_line(&ident, ident_line, ident_len) ||
598 !ident.date_begin || !ident.date_end)
599 goto fail_exit; /* malformed "author" line */
601 date = strtoul(ident.date_begin, &date_end, 10);
602 if (date_end != ident.date_end)
603 goto fail_exit; /* malformed date */
604 *(author_date_slab_at(author_date, commit)) = date;
606 fail_exit:
607 unuse_commit_buffer(commit, buffer);
610 static int compare_commits_by_author_date(const void *a_, const void *b_,
611 void *cb_data)
613 const struct commit *a = a_, *b = b_;
614 struct author_date_slab *author_date = cb_data;
615 unsigned long a_date = *(author_date_slab_at(author_date, a));
616 unsigned long b_date = *(author_date_slab_at(author_date, b));
618 /* newer commits with larger date first */
619 if (a_date < b_date)
620 return 1;
621 else if (a_date > b_date)
622 return -1;
623 return 0;
626 int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
628 const struct commit *a = a_, *b = b_;
629 /* newer commits with larger date first */
630 if (a->date < b->date)
631 return 1;
632 else if (a->date > b->date)
633 return -1;
634 return 0;
638 * Performs an in-place topological sort on the list supplied.
640 void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
642 struct commit_list *next, *orig = *list;
643 struct commit_list **pptr;
644 struct indegree_slab indegree;
645 struct prio_queue queue;
646 struct commit *commit;
647 struct author_date_slab author_date;
649 if (!orig)
650 return;
651 *list = NULL;
653 init_indegree_slab(&indegree);
654 memset(&queue, '\0', sizeof(queue));
656 switch (sort_order) {
657 default: /* REV_SORT_IN_GRAPH_ORDER */
658 queue.compare = NULL;
659 break;
660 case REV_SORT_BY_COMMIT_DATE:
661 queue.compare = compare_commits_by_commit_date;
662 break;
663 case REV_SORT_BY_AUTHOR_DATE:
664 init_author_date_slab(&author_date);
665 queue.compare = compare_commits_by_author_date;
666 queue.cb_data = &author_date;
667 break;
670 /* Mark them and clear the indegree */
671 for (next = orig; next; next = next->next) {
672 struct commit *commit = next->item;
673 *(indegree_slab_at(&indegree, commit)) = 1;
674 /* also record the author dates, if needed */
675 if (sort_order == REV_SORT_BY_AUTHOR_DATE)
676 record_author_date(&author_date, commit);
679 /* update the indegree */
680 for (next = orig; next; next = next->next) {
681 struct commit_list *parents = next->item->parents;
682 while (parents) {
683 struct commit *parent = parents->item;
684 int *pi = indegree_slab_at(&indegree, parent);
686 if (*pi)
687 (*pi)++;
688 parents = parents->next;
693 * find the tips
695 * tips are nodes not reachable from any other node in the list
697 * the tips serve as a starting set for the work queue.
699 for (next = orig; next; next = next->next) {
700 struct commit *commit = next->item;
702 if (*(indegree_slab_at(&indegree, commit)) == 1)
703 prio_queue_put(&queue, commit);
707 * This is unfortunate; the initial tips need to be shown
708 * in the order given from the revision traversal machinery.
710 if (sort_order == REV_SORT_IN_GRAPH_ORDER)
711 prio_queue_reverse(&queue);
713 /* We no longer need the commit list */
714 free_commit_list(orig);
716 pptr = list;
717 *list = NULL;
718 while ((commit = prio_queue_get(&queue)) != NULL) {
719 struct commit_list *parents;
721 for (parents = commit->parents; parents ; parents = parents->next) {
722 struct commit *parent = parents->item;
723 int *pi = indegree_slab_at(&indegree, parent);
725 if (!*pi)
726 continue;
729 * parents are only enqueued for emission
730 * when all their children have been emitted thereby
731 * guaranteeing topological order.
733 if (--(*pi) == 1)
734 prio_queue_put(&queue, parent);
737 * all children of commit have already been
738 * emitted. we can emit it now.
740 *(indegree_slab_at(&indegree, commit)) = 0;
742 pptr = &commit_list_insert(commit, pptr)->next;
745 clear_indegree_slab(&indegree);
746 clear_prio_queue(&queue);
747 if (sort_order == REV_SORT_BY_AUTHOR_DATE)
748 clear_author_date_slab(&author_date);
751 /* merge-base stuff */
753 /* Remember to update object flag allocation in object.h */
754 #define PARENT1 (1u<<16)
755 #define PARENT2 (1u<<17)
756 #define STALE (1u<<18)
757 #define RESULT (1u<<19)
759 static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
761 static int queue_has_nonstale(struct prio_queue *queue)
763 int i;
764 for (i = 0; i < queue->nr; i++) {
765 struct commit *commit = queue->array[i].data;
766 if (!(commit->object.flags & STALE))
767 return 1;
769 return 0;
772 /* all input commits in one and twos[] must have been parsed! */
773 static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
775 struct prio_queue queue = { compare_commits_by_commit_date };
776 struct commit_list *result = NULL;
777 int i;
779 one->object.flags |= PARENT1;
780 if (!n) {
781 commit_list_append(one, &result);
782 return result;
784 prio_queue_put(&queue, one);
786 for (i = 0; i < n; i++) {
787 twos[i]->object.flags |= PARENT2;
788 prio_queue_put(&queue, twos[i]);
791 while (queue_has_nonstale(&queue)) {
792 struct commit *commit = prio_queue_get(&queue);
793 struct commit_list *parents;
794 int flags;
796 flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
797 if (flags == (PARENT1 | PARENT2)) {
798 if (!(commit->object.flags & RESULT)) {
799 commit->object.flags |= RESULT;
800 commit_list_insert_by_date(commit, &result);
802 /* Mark parents of a found merge stale */
803 flags |= STALE;
805 parents = commit->parents;
806 while (parents) {
807 struct commit *p = parents->item;
808 parents = parents->next;
809 if ((p->object.flags & flags) == flags)
810 continue;
811 if (parse_commit(p))
812 return NULL;
813 p->object.flags |= flags;
814 prio_queue_put(&queue, p);
818 clear_prio_queue(&queue);
819 return result;
822 static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
824 struct commit_list *list = NULL;
825 struct commit_list *result = NULL;
826 int i;
828 for (i = 0; i < n; i++) {
829 if (one == twos[i])
831 * We do not mark this even with RESULT so we do not
832 * have to clean it up.
834 return commit_list_insert(one, &result);
837 if (parse_commit(one))
838 return NULL;
839 for (i = 0; i < n; i++) {
840 if (parse_commit(twos[i]))
841 return NULL;
844 list = paint_down_to_common(one, n, twos);
846 while (list) {
847 struct commit_list *next = list->next;
848 if (!(list->item->object.flags & STALE))
849 commit_list_insert_by_date(list->item, &result);
850 free(list);
851 list = next;
853 return result;
856 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
858 struct commit_list *i, *j, *k, *ret = NULL;
860 if (!in)
861 return ret;
863 commit_list_insert(in->item, &ret);
865 for (i = in->next; i; i = i->next) {
866 struct commit_list *new = NULL, *end = NULL;
868 for (j = ret; j; j = j->next) {
869 struct commit_list *bases;
870 bases = get_merge_bases(i->item, j->item, 1);
871 if (!new)
872 new = bases;
873 else
874 end->next = bases;
875 for (k = bases; k; k = k->next)
876 end = k;
878 ret = new;
880 return ret;
883 static int remove_redundant(struct commit **array, int cnt)
886 * Some commit in the array may be an ancestor of
887 * another commit. Move such commit to the end of
888 * the array, and return the number of commits that
889 * are independent from each other.
891 struct commit **work;
892 unsigned char *redundant;
893 int *filled_index;
894 int i, j, filled;
896 work = xcalloc(cnt, sizeof(*work));
897 redundant = xcalloc(cnt, 1);
898 filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
900 for (i = 0; i < cnt; i++)
901 parse_commit(array[i]);
902 for (i = 0; i < cnt; i++) {
903 struct commit_list *common;
905 if (redundant[i])
906 continue;
907 for (j = filled = 0; j < cnt; j++) {
908 if (i == j || redundant[j])
909 continue;
910 filled_index[filled] = j;
911 work[filled++] = array[j];
913 common = paint_down_to_common(array[i], filled, work);
914 if (array[i]->object.flags & PARENT2)
915 redundant[i] = 1;
916 for (j = 0; j < filled; j++)
917 if (work[j]->object.flags & PARENT1)
918 redundant[filled_index[j]] = 1;
919 clear_commit_marks(array[i], all_flags);
920 for (j = 0; j < filled; j++)
921 clear_commit_marks(work[j], all_flags);
922 free_commit_list(common);
925 /* Now collect the result */
926 memcpy(work, array, sizeof(*array) * cnt);
927 for (i = filled = 0; i < cnt; i++)
928 if (!redundant[i])
929 array[filled++] = work[i];
930 for (j = filled, i = 0; i < cnt; i++)
931 if (redundant[i])
932 array[j++] = work[i];
933 free(work);
934 free(redundant);
935 free(filled_index);
936 return filled;
939 struct commit_list *get_merge_bases_many(struct commit *one,
940 int n,
941 struct commit **twos,
942 int cleanup)
944 struct commit_list *list;
945 struct commit **rslt;
946 struct commit_list *result;
947 int cnt, i;
949 result = merge_bases_many(one, n, twos);
950 for (i = 0; i < n; i++) {
951 if (one == twos[i])
952 return result;
954 if (!result || !result->next) {
955 if (cleanup) {
956 clear_commit_marks(one, all_flags);
957 clear_commit_marks_many(n, twos, all_flags);
959 return result;
962 /* There are more than one */
963 cnt = commit_list_count(result);
964 rslt = xcalloc(cnt, sizeof(*rslt));
965 for (list = result, i = 0; list; list = list->next)
966 rslt[i++] = list->item;
967 free_commit_list(result);
969 clear_commit_marks(one, all_flags);
970 clear_commit_marks_many(n, twos, all_flags);
972 cnt = remove_redundant(rslt, cnt);
973 result = NULL;
974 for (i = 0; i < cnt; i++)
975 commit_list_insert_by_date(rslt[i], &result);
976 free(rslt);
977 return result;
980 struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
981 int cleanup)
983 return get_merge_bases_many(one, 1, &two, cleanup);
987 * Is "commit" a descendant of one of the elements on the "with_commit" list?
989 int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
991 if (!with_commit)
992 return 1;
993 while (with_commit) {
994 struct commit *other;
996 other = with_commit->item;
997 with_commit = with_commit->next;
998 if (in_merge_bases(other, commit))
999 return 1;
1001 return 0;
1005 * Is "commit" an ancestor of one of the "references"?
1007 int in_merge_bases_many(struct commit *commit, int nr_reference, struct commit **reference)
1009 struct commit_list *bases;
1010 int ret = 0, i;
1012 if (parse_commit(commit))
1013 return ret;
1014 for (i = 0; i < nr_reference; i++)
1015 if (parse_commit(reference[i]))
1016 return ret;
1018 bases = paint_down_to_common(commit, nr_reference, reference);
1019 if (commit->object.flags & PARENT2)
1020 ret = 1;
1021 clear_commit_marks(commit, all_flags);
1022 clear_commit_marks_many(nr_reference, reference, all_flags);
1023 free_commit_list(bases);
1024 return ret;
1028 * Is "commit" an ancestor of (i.e. reachable from) the "reference"?
1030 int in_merge_bases(struct commit *commit, struct commit *reference)
1032 return in_merge_bases_many(commit, 1, &reference);
1035 struct commit_list *reduce_heads(struct commit_list *heads)
1037 struct commit_list *p;
1038 struct commit_list *result = NULL, **tail = &result;
1039 struct commit **array;
1040 int num_head, i;
1042 if (!heads)
1043 return NULL;
1045 /* Uniquify */
1046 for (p = heads; p; p = p->next)
1047 p->item->object.flags &= ~STALE;
1048 for (p = heads, num_head = 0; p; p = p->next) {
1049 if (p->item->object.flags & STALE)
1050 continue;
1051 p->item->object.flags |= STALE;
1052 num_head++;
1054 array = xcalloc(num_head, sizeof(*array));
1055 for (p = heads, i = 0; p; p = p->next) {
1056 if (p->item->object.flags & STALE) {
1057 array[i++] = p->item;
1058 p->item->object.flags &= ~STALE;
1061 num_head = remove_redundant(array, num_head);
1062 for (i = 0; i < num_head; i++)
1063 tail = &commit_list_insert(array[i], tail)->next;
1064 return result;
1067 static const char gpg_sig_header[] = "gpgsig";
1068 static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
1070 static int do_sign_commit(struct strbuf *buf, const char *keyid)
1072 struct strbuf sig = STRBUF_INIT;
1073 int inspos, copypos;
1075 /* find the end of the header */
1076 inspos = strstr(buf->buf, "\n\n") - buf->buf + 1;
1078 if (!keyid || !*keyid)
1079 keyid = get_signing_key();
1080 if (sign_buffer(buf, &sig, keyid)) {
1081 strbuf_release(&sig);
1082 return -1;
1085 for (copypos = 0; sig.buf[copypos]; ) {
1086 const char *bol = sig.buf + copypos;
1087 const char *eol = strchrnul(bol, '\n');
1088 int len = (eol - bol) + !!*eol;
1090 if (!copypos) {
1091 strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
1092 inspos += gpg_sig_header_len;
1094 strbuf_insert(buf, inspos++, " ", 1);
1095 strbuf_insert(buf, inspos, bol, len);
1096 inspos += len;
1097 copypos += len;
1099 strbuf_release(&sig);
1100 return 0;
1103 int parse_signed_commit(const struct commit *commit,
1104 struct strbuf *payload, struct strbuf *signature)
1107 unsigned long size;
1108 const char *buffer = get_commit_buffer(commit, &size);
1109 int in_signature, saw_signature = -1;
1110 const char *line, *tail;
1112 line = buffer;
1113 tail = buffer + size;
1114 in_signature = 0;
1115 saw_signature = 0;
1116 while (line < tail) {
1117 const char *sig = NULL;
1118 const char *next = memchr(line, '\n', tail - line);
1120 next = next ? next + 1 : tail;
1121 if (in_signature && line[0] == ' ')
1122 sig = line + 1;
1123 else if (starts_with(line, gpg_sig_header) &&
1124 line[gpg_sig_header_len] == ' ')
1125 sig = line + gpg_sig_header_len + 1;
1126 if (sig) {
1127 strbuf_add(signature, sig, next - sig);
1128 saw_signature = 1;
1129 in_signature = 1;
1130 } else {
1131 if (*line == '\n')
1132 /* dump the whole remainder of the buffer */
1133 next = tail;
1134 strbuf_add(payload, line, next - line);
1135 in_signature = 0;
1137 line = next;
1139 unuse_commit_buffer(commit, buffer);
1140 return saw_signature;
1143 int remove_signature(struct strbuf *buf)
1145 const char *line = buf->buf;
1146 const char *tail = buf->buf + buf->len;
1147 int in_signature = 0;
1148 const char *sig_start = NULL;
1149 const char *sig_end = NULL;
1151 while (line < tail) {
1152 const char *next = memchr(line, '\n', tail - line);
1153 next = next ? next + 1 : tail;
1155 if (in_signature && line[0] == ' ')
1156 sig_end = next;
1157 else if (starts_with(line, gpg_sig_header) &&
1158 line[gpg_sig_header_len] == ' ') {
1159 sig_start = line;
1160 sig_end = next;
1161 in_signature = 1;
1162 } else {
1163 if (*line == '\n')
1164 /* dump the whole remainder of the buffer */
1165 next = tail;
1166 in_signature = 0;
1168 line = next;
1171 if (sig_start)
1172 strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
1174 return sig_start != NULL;
1177 static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
1179 struct merge_remote_desc *desc;
1180 struct commit_extra_header *mergetag;
1181 char *buf;
1182 unsigned long size, len;
1183 enum object_type type;
1185 desc = merge_remote_util(parent);
1186 if (!desc || !desc->obj)
1187 return;
1188 buf = read_sha1_file(desc->obj->sha1, &type, &size);
1189 if (!buf || type != OBJ_TAG)
1190 goto free_return;
1191 len = parse_signature(buf, size);
1192 if (size == len)
1193 goto free_return;
1195 * We could verify this signature and either omit the tag when
1196 * it does not validate, but the integrator may not have the
1197 * public key of the signer of the tag he is merging, while a
1198 * later auditor may have it while auditing, so let's not run
1199 * verify-signed-buffer here for now...
1201 * if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
1202 * warn("warning: signed tag unverified.");
1204 mergetag = xcalloc(1, sizeof(*mergetag));
1205 mergetag->key = xstrdup("mergetag");
1206 mergetag->value = buf;
1207 mergetag->len = size;
1209 **tail = mergetag;
1210 *tail = &mergetag->next;
1211 return;
1213 free_return:
1214 free(buf);
1217 void check_commit_signature(const struct commit *commit, struct signature_check *sigc)
1219 struct strbuf payload = STRBUF_INIT;
1220 struct strbuf signature = STRBUF_INIT;
1221 struct strbuf gpg_output = STRBUF_INIT;
1222 struct strbuf gpg_status = STRBUF_INIT;
1223 int status;
1225 sigc->result = 'N';
1227 if (parse_signed_commit(commit, &payload, &signature) <= 0)
1228 goto out;
1229 status = verify_signed_buffer(payload.buf, payload.len,
1230 signature.buf, signature.len,
1231 &gpg_output, &gpg_status);
1232 if (status && !gpg_output.len)
1233 goto out;
1234 sigc->payload = strbuf_detach(&payload, NULL);
1235 sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
1236 sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
1237 parse_gpg_output(sigc);
1239 out:
1240 strbuf_release(&gpg_status);
1241 strbuf_release(&gpg_output);
1242 strbuf_release(&payload);
1243 strbuf_release(&signature);
1248 void append_merge_tag_headers(struct commit_list *parents,
1249 struct commit_extra_header ***tail)
1251 while (parents) {
1252 struct commit *parent = parents->item;
1253 handle_signed_tag(parent, tail);
1254 parents = parents->next;
1258 static void add_extra_header(struct strbuf *buffer,
1259 struct commit_extra_header *extra)
1261 strbuf_addstr(buffer, extra->key);
1262 if (extra->len)
1263 strbuf_add_lines(buffer, " ", extra->value, extra->len);
1264 else
1265 strbuf_addch(buffer, '\n');
1268 struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
1269 const char **exclude)
1271 struct commit_extra_header *extra = NULL;
1272 unsigned long size;
1273 const char *buffer = get_commit_buffer(commit, &size);
1274 extra = read_commit_extra_header_lines(buffer, size, exclude);
1275 unuse_commit_buffer(commit, buffer);
1276 return extra;
1279 void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
1281 struct commit_extra_header *extra, *to_free;
1283 to_free = read_commit_extra_headers(commit, NULL);
1284 for (extra = to_free; extra; extra = extra->next) {
1285 if (strcmp(extra->key, "mergetag"))
1286 continue; /* not a merge tag */
1287 fn(commit, extra, data);
1289 free_commit_extra_headers(to_free);
1292 static inline int standard_header_field(const char *field, size_t len)
1294 return ((len == 4 && !memcmp(field, "tree ", 5)) ||
1295 (len == 6 && !memcmp(field, "parent ", 7)) ||
1296 (len == 6 && !memcmp(field, "author ", 7)) ||
1297 (len == 9 && !memcmp(field, "committer ", 10)) ||
1298 (len == 8 && !memcmp(field, "encoding ", 9)));
1301 static int excluded_header_field(const char *field, size_t len, const char **exclude)
1303 if (!exclude)
1304 return 0;
1306 while (*exclude) {
1307 size_t xlen = strlen(*exclude);
1308 if (len == xlen &&
1309 !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
1310 return 1;
1311 exclude++;
1313 return 0;
1316 static struct commit_extra_header *read_commit_extra_header_lines(
1317 const char *buffer, size_t size,
1318 const char **exclude)
1320 struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
1321 const char *line, *next, *eof, *eob;
1322 struct strbuf buf = STRBUF_INIT;
1324 for (line = buffer, eob = line + size;
1325 line < eob && *line != '\n';
1326 line = next) {
1327 next = memchr(line, '\n', eob - line);
1328 next = next ? next + 1 : eob;
1329 if (*line == ' ') {
1330 /* continuation */
1331 if (it)
1332 strbuf_add(&buf, line + 1, next - (line + 1));
1333 continue;
1335 if (it)
1336 it->value = strbuf_detach(&buf, &it->len);
1337 strbuf_reset(&buf);
1338 it = NULL;
1340 eof = strchr(line, ' ');
1341 if (next <= eof)
1342 eof = next;
1344 if (standard_header_field(line, eof - line) ||
1345 excluded_header_field(line, eof - line, exclude))
1346 continue;
1348 it = xcalloc(1, sizeof(*it));
1349 it->key = xmemdupz(line, eof-line);
1350 *tail = it;
1351 tail = &it->next;
1352 if (eof + 1 < next)
1353 strbuf_add(&buf, eof + 1, next - (eof + 1));
1355 if (it)
1356 it->value = strbuf_detach(&buf, &it->len);
1357 return extra;
1360 void free_commit_extra_headers(struct commit_extra_header *extra)
1362 while (extra) {
1363 struct commit_extra_header *next = extra->next;
1364 free(extra->key);
1365 free(extra->value);
1366 free(extra);
1367 extra = next;
1371 int commit_tree(const char *msg, size_t msg_len,
1372 const unsigned char *tree,
1373 struct commit_list *parents, unsigned char *ret,
1374 const char *author, const char *sign_commit)
1376 struct commit_extra_header *extra = NULL, **tail = &extra;
1377 int result;
1379 append_merge_tag_headers(parents, &tail);
1380 result = commit_tree_extended(msg, msg_len, tree, parents, ret,
1381 author, sign_commit, extra);
1382 free_commit_extra_headers(extra);
1383 return result;
1386 static int find_invalid_utf8(const char *buf, int len)
1388 int offset = 0;
1389 static const unsigned int max_codepoint[] = {
1390 0x7f, 0x7ff, 0xffff, 0x10ffff
1393 while (len) {
1394 unsigned char c = *buf++;
1395 int bytes, bad_offset;
1396 unsigned int codepoint;
1397 unsigned int min_val, max_val;
1399 len--;
1400 offset++;
1402 /* Simple US-ASCII? No worries. */
1403 if (c < 0x80)
1404 continue;
1406 bad_offset = offset-1;
1409 * Count how many more high bits set: that's how
1410 * many more bytes this sequence should have.
1412 bytes = 0;
1413 while (c & 0x40) {
1414 c <<= 1;
1415 bytes++;
1419 * Must be between 1 and 3 more bytes. Longer sequences result in
1420 * codepoints beyond U+10FFFF, which are guaranteed never to exist.
1422 if (bytes < 1 || 3 < bytes)
1423 return bad_offset;
1425 /* Do we *have* that many bytes? */
1426 if (len < bytes)
1427 return bad_offset;
1430 * Place the encoded bits at the bottom of the value and compute the
1431 * valid range.
1433 codepoint = (c & 0x7f) >> bytes;
1434 min_val = max_codepoint[bytes-1] + 1;
1435 max_val = max_codepoint[bytes];
1437 offset += bytes;
1438 len -= bytes;
1440 /* And verify that they are good continuation bytes */
1441 do {
1442 codepoint <<= 6;
1443 codepoint |= *buf & 0x3f;
1444 if ((*buf++ & 0xc0) != 0x80)
1445 return bad_offset;
1446 } while (--bytes);
1448 /* Reject codepoints that are out of range for the sequence length. */
1449 if (codepoint < min_val || codepoint > max_val)
1450 return bad_offset;
1451 /* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
1452 if ((codepoint & 0x1ff800) == 0xd800)
1453 return bad_offset;
1454 /* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
1455 if ((codepoint & 0xfffe) == 0xfffe)
1456 return bad_offset;
1457 /* So are anything in the range U+FDD0..U+FDEF. */
1458 if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
1459 return bad_offset;
1461 return -1;
1465 * This verifies that the buffer is in proper utf8 format.
1467 * If it isn't, it assumes any non-utf8 characters are Latin1,
1468 * and does the conversion.
1470 static int verify_utf8(struct strbuf *buf)
1472 int ok = 1;
1473 long pos = 0;
1475 for (;;) {
1476 int bad;
1477 unsigned char c;
1478 unsigned char replace[2];
1480 bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
1481 if (bad < 0)
1482 return ok;
1483 pos += bad;
1484 ok = 0;
1485 c = buf->buf[pos];
1486 strbuf_remove(buf, pos, 1);
1488 /* We know 'c' must be in the range 128-255 */
1489 replace[0] = 0xc0 + (c >> 6);
1490 replace[1] = 0x80 + (c & 0x3f);
1491 strbuf_insert(buf, pos, replace, 2);
1492 pos += 2;
1496 static const char commit_utf8_warn[] =
1497 "Warning: commit message did not conform to UTF-8.\n"
1498 "You may want to amend it after fixing the message, or set the config\n"
1499 "variable i18n.commitencoding to the encoding your project uses.\n";
1501 int commit_tree_extended(const char *msg, size_t msg_len,
1502 const unsigned char *tree,
1503 struct commit_list *parents, unsigned char *ret,
1504 const char *author, const char *sign_commit,
1505 struct commit_extra_header *extra)
1507 int result;
1508 int encoding_is_utf8;
1509 struct strbuf buffer;
1511 assert_sha1_type(tree, OBJ_TREE);
1513 if (memchr(msg, '\0', msg_len))
1514 return error("a NUL byte in commit log message not allowed.");
1516 /* Not having i18n.commitencoding is the same as having utf-8 */
1517 encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
1519 strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
1520 strbuf_addf(&buffer, "tree %s\n", sha1_to_hex(tree));
1523 * NOTE! This ordering means that the same exact tree merged with a
1524 * different order of parents will be a _different_ changeset even
1525 * if everything else stays the same.
1527 while (parents) {
1528 struct commit_list *next = parents->next;
1529 struct commit *parent = parents->item;
1531 strbuf_addf(&buffer, "parent %s\n",
1532 sha1_to_hex(parent->object.sha1));
1533 free(parents);
1534 parents = next;
1537 /* Person/date information */
1538 if (!author)
1539 author = git_author_info(IDENT_STRICT);
1540 strbuf_addf(&buffer, "author %s\n", author);
1541 strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
1542 if (!encoding_is_utf8)
1543 strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
1545 while (extra) {
1546 add_extra_header(&buffer, extra);
1547 extra = extra->next;
1549 strbuf_addch(&buffer, '\n');
1551 /* And add the comment */
1552 strbuf_add(&buffer, msg, msg_len);
1554 /* And check the encoding */
1555 if (encoding_is_utf8 && !verify_utf8(&buffer))
1556 fprintf(stderr, commit_utf8_warn);
1558 if (sign_commit && do_sign_commit(&buffer, sign_commit))
1559 return -1;
1561 result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
1562 strbuf_release(&buffer);
1563 return result;
1566 struct commit *get_merge_parent(const char *name)
1568 struct object *obj;
1569 struct commit *commit;
1570 unsigned char sha1[20];
1571 if (get_sha1(name, sha1))
1572 return NULL;
1573 obj = parse_object(sha1);
1574 commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
1575 if (commit && !commit->util) {
1576 struct merge_remote_desc *desc;
1577 desc = xmalloc(sizeof(*desc));
1578 desc->obj = obj;
1579 desc->name = strdup(name);
1580 commit->util = desc;
1582 return commit;
1586 * Append a commit to the end of the commit_list.
1588 * next starts by pointing to the variable that holds the head of an
1589 * empty commit_list, and is updated to point to the "next" field of
1590 * the last item on the list as new commits are appended.
1592 * Usage example:
1594 * struct commit_list *list;
1595 * struct commit_list **next = &list;
1597 * next = commit_list_append(c1, next);
1598 * next = commit_list_append(c2, next);
1599 * assert(commit_list_count(list) == 2);
1600 * return list;
1602 struct commit_list **commit_list_append(struct commit *commit,
1603 struct commit_list **next)
1605 struct commit_list *new = xmalloc(sizeof(struct commit_list));
1606 new->item = commit;
1607 *next = new;
1608 new->next = NULL;
1609 return &new->next;
1612 void print_commit_list(struct commit_list *list,
1613 const char *format_cur,
1614 const char *format_last)
1616 for ( ; list; list = list->next) {
1617 const char *format = list->next ? format_cur : format_last;
1618 printf(format, sha1_to_hex(list->item->object.sha1));
1622 const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
1624 int key_len = strlen(key);
1625 const char *line = msg;
1627 while (line) {
1628 const char *eol = strchrnul(line, '\n');
1630 if (line == eol)
1631 return NULL;
1633 if (eol - line > key_len &&
1634 !strncmp(line, key, key_len) &&
1635 line[key_len] == ' ') {
1636 *out_len = eol - line - key_len - 1;
1637 return line + key_len + 1;
1639 line = *eol ? eol + 1 : NULL;
1641 return NULL;