ce35b5a7e6960383debb4541c573ecf02d192cae
[git/git.git] / revision.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "refs.h"
8 #include "revision.h"
9
10 static char *path_name(struct name_path *path, const char *name)
11 {
12 struct name_path *p;
13 char *n, *m;
14 int nlen = strlen(name);
15 int len = nlen + 1;
16
17 for (p = path; p; p = p->up) {
18 if (p->elem_len)
19 len += p->elem_len + 1;
20 }
21 n = xmalloc(len);
22 m = n + len - (nlen + 1);
23 strcpy(m, name);
24 for (p = path; p; p = p->up) {
25 if (p->elem_len) {
26 m -= p->elem_len + 1;
27 memcpy(m, p->elem, p->elem_len);
28 m[p->elem_len] = '/';
29 }
30 }
31 return n;
32 }
33
34 struct object_list **add_object(struct object *obj,
35 struct object_list **p,
36 struct name_path *path,
37 const char *name)
38 {
39 struct object_list *entry = xmalloc(sizeof(*entry));
40 entry->item = obj;
41 entry->next = *p;
42 entry->name = path_name(path, name);
43 *p = entry;
44 return &entry->next;
45 }
46
47 static void mark_blob_uninteresting(struct blob *blob)
48 {
49 if (blob->object.flags & UNINTERESTING)
50 return;
51 blob->object.flags |= UNINTERESTING;
52 }
53
54 void mark_tree_uninteresting(struct tree *tree)
55 {
56 struct object *obj = &tree->object;
57 struct tree_entry_list *entry;
58
59 if (obj->flags & UNINTERESTING)
60 return;
61 obj->flags |= UNINTERESTING;
62 if (!has_sha1_file(obj->sha1))
63 return;
64 if (parse_tree(tree) < 0)
65 die("bad tree %s", sha1_to_hex(obj->sha1));
66 entry = tree->entries;
67 tree->entries = NULL;
68 while (entry) {
69 struct tree_entry_list *next = entry->next;
70 if (entry->directory)
71 mark_tree_uninteresting(entry->item.tree);
72 else
73 mark_blob_uninteresting(entry->item.blob);
74 free(entry);
75 entry = next;
76 }
77 }
78
79 void mark_parents_uninteresting(struct commit *commit)
80 {
81 struct commit_list *parents = commit->parents;
82
83 while (parents) {
84 struct commit *commit = parents->item;
85 if (!(commit->object.flags & UNINTERESTING)) {
86 commit->object.flags |= UNINTERESTING;
87
88 /*
89 * Normally we haven't parsed the parent
90 * yet, so we won't have a parent of a parent
91 * here. However, it may turn out that we've
92 * reached this commit some other way (where it
93 * wasn't uninteresting), in which case we need
94 * to mark its parents recursively too..
95 */
96 if (commit->parents)
97 mark_parents_uninteresting(commit);
98 }
99
100 /*
101 * A missing commit is ok iff its parent is marked
102 * uninteresting.
103 *
104 * We just mark such a thing parsed, so that when
105 * it is popped next time around, we won't be trying
106 * to parse it and get an error.
107 */
108 if (!has_sha1_file(commit->object.sha1))
109 commit->object.parsed = 1;
110 parents = parents->next;
111 }
112 }
113
114 static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
115 {
116 add_object(obj, &revs->pending_objects, NULL, name);
117 }
118
119 static struct commit *get_commit_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
120 {
121 struct object *object;
122
123 object = parse_object(sha1);
124 if (!object)
125 die("bad object %s", name);
126
127 /*
128 * Tag object? Look what it points to..
129 */
130 while (object->type == tag_type) {
131 struct tag *tag = (struct tag *) object;
132 object->flags |= flags;
133 if (revs->tag_objects && !(object->flags & UNINTERESTING))
134 add_pending_object(revs, object, tag->tag);
135 object = parse_object(tag->tagged->sha1);
136 if (!object)
137 die("bad object %s", sha1_to_hex(tag->tagged->sha1));
138 }
139
140 /*
141 * Commit object? Just return it, we'll do all the complex
142 * reachability crud.
143 */
144 if (object->type == commit_type) {
145 struct commit *commit = (struct commit *)object;
146 object->flags |= flags;
147 if (parse_commit(commit) < 0)
148 die("unable to parse commit %s", name);
149 if (flags & UNINTERESTING) {
150 mark_parents_uninteresting(commit);
151 revs->limited = 1;
152 }
153 return commit;
154 }
155
156 /*
157 * Tree object? Either mark it uniniteresting, or add it
158 * to the list of objects to look at later..
159 */
160 if (object->type == tree_type) {
161 struct tree *tree = (struct tree *)object;
162 if (!revs->tree_objects)
163 return NULL;
164 if (flags & UNINTERESTING) {
165 mark_tree_uninteresting(tree);
166 return NULL;
167 }
168 add_pending_object(revs, object, "");
169 return NULL;
170 }
171
172 /*
173 * Blob object? You know the drill by now..
174 */
175 if (object->type == blob_type) {
176 struct blob *blob = (struct blob *)object;
177 if (!revs->blob_objects)
178 return NULL;
179 if (flags & UNINTERESTING) {
180 mark_blob_uninteresting(blob);
181 return NULL;
182 }
183 add_pending_object(revs, object, "");
184 return NULL;
185 }
186 die("%s is unknown object", name);
187 }
188
189 static int everybody_uninteresting(struct commit_list *orig)
190 {
191 struct commit_list *list = orig;
192 while (list) {
193 struct commit *commit = list->item;
194 list = list->next;
195 if (commit->object.flags & UNINTERESTING)
196 continue;
197 return 0;
198 }
199 return 1;
200 }
201
202 static int tree_difference = REV_TREE_SAME;
203
204 static void file_add_remove(struct diff_options *options,
205 int addremove, unsigned mode,
206 const unsigned char *sha1,
207 const char *base, const char *path)
208 {
209 int diff = REV_TREE_DIFFERENT;
210
211 /*
212 * Is it an add of a new file? It means that the old tree
213 * didn't have it at all, so we will turn "REV_TREE_SAME" ->
214 * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
215 * (and if it already was "REV_TREE_NEW", we'll keep it
216 * "REV_TREE_NEW" of course).
217 */
218 if (addremove == '+') {
219 diff = tree_difference;
220 if (diff != REV_TREE_SAME)
221 return;
222 diff = REV_TREE_NEW;
223 }
224 tree_difference = diff;
225 }
226
227 static void file_change(struct diff_options *options,
228 unsigned old_mode, unsigned new_mode,
229 const unsigned char *old_sha1,
230 const unsigned char *new_sha1,
231 const char *base, const char *path)
232 {
233 tree_difference = REV_TREE_DIFFERENT;
234 }
235
236 static struct diff_options diff_opt = {
237 .recursive = 1,
238 .add_remove = file_add_remove,
239 .change = file_change,
240 };
241
242 int rev_compare_tree(struct tree *t1, struct tree *t2)
243 {
244 if (!t1)
245 return REV_TREE_NEW;
246 if (!t2)
247 return REV_TREE_DIFFERENT;
248 tree_difference = REV_TREE_SAME;
249 if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
250 return REV_TREE_DIFFERENT;
251 return tree_difference;
252 }
253
254 int rev_same_tree_as_empty(struct tree *t1)
255 {
256 int retval;
257 void *tree;
258 struct tree_desc empty, real;
259
260 if (!t1)
261 return 0;
262
263 tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
264 if (!tree)
265 return 0;
266 real.buf = tree;
267
268 empty.buf = "";
269 empty.size = 0;
270
271 tree_difference = 0;
272 retval = diff_tree(&empty, &real, "", &diff_opt);
273 free(tree);
274
275 return retval >= 0 && !tree_difference;
276 }
277
278 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
279 {
280 struct commit_list **pp, *parent;
281 int tree_changed = 0;
282
283 if (!commit->tree)
284 return;
285
286 if (!commit->parents) {
287 if (!rev_same_tree_as_empty(commit->tree))
288 commit->object.flags |= TREECHANGE;
289 return;
290 }
291
292 pp = &commit->parents;
293 while ((parent = *pp) != NULL) {
294 struct commit *p = parent->item;
295
296 parse_commit(p);
297 switch (rev_compare_tree(p->tree, commit->tree)) {
298 case REV_TREE_SAME:
299 if (p->object.flags & UNINTERESTING) {
300 /* Even if a merge with an uninteresting
301 * side branch brought the entire change
302 * we are interested in, we do not want
303 * to lose the other branches of this
304 * merge, so we just keep going.
305 */
306 pp = &parent->next;
307 continue;
308 }
309 parent->next = NULL;
310 commit->parents = parent;
311 return;
312
313 case REV_TREE_NEW:
314 if (revs->remove_empty_trees &&
315 rev_same_tree_as_empty(p->tree)) {
316 /* We are adding all the specified
317 * paths from this parent, so the
318 * history beyond this parent is not
319 * interesting. Remove its parents
320 * (they are grandparents for us).
321 * IOW, we pretend this parent is a
322 * "root" commit.
323 */
324 parse_commit(p);
325 p->parents = NULL;
326 }
327 /* fallthrough */
328 case REV_TREE_DIFFERENT:
329 tree_changed = 1;
330 pp = &parent->next;
331 continue;
332 }
333 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
334 }
335 if (tree_changed)
336 commit->object.flags |= TREECHANGE;
337 }
338
339 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
340 {
341 struct commit_list *parent = commit->parents;
342
343 /*
344 * If the commit is uninteresting, don't try to
345 * prune parents - we want the maximal uninteresting
346 * set.
347 *
348 * Normally we haven't parsed the parent
349 * yet, so we won't have a parent of a parent
350 * here. However, it may turn out that we've
351 * reached this commit some other way (where it
352 * wasn't uninteresting), in which case we need
353 * to mark its parents recursively too..
354 */
355 if (commit->object.flags & UNINTERESTING) {
356 while (parent) {
357 struct commit *p = parent->item;
358 parent = parent->next;
359 parse_commit(p);
360 p->object.flags |= UNINTERESTING;
361 if (p->parents)
362 mark_parents_uninteresting(p);
363 if (p->object.flags & SEEN)
364 continue;
365 p->object.flags |= SEEN;
366 insert_by_date(p, list);
367 }
368 return;
369 }
370
371 /*
372 * Ok, the commit wasn't uninteresting. Try to
373 * simplify the commit history and find the parent
374 * that has no differences in the path set if one exists.
375 */
376 if (revs->prune_fn)
377 revs->prune_fn(revs, commit);
378
379 parent = commit->parents;
380 while (parent) {
381 struct commit *p = parent->item;
382
383 parent = parent->next;
384
385 parse_commit(p);
386 if (p->object.flags & SEEN)
387 continue;
388 p->object.flags |= SEEN;
389 insert_by_date(p, list);
390 }
391 }
392
393 static void limit_list(struct rev_info *revs)
394 {
395 struct commit_list *list = revs->commits;
396 struct commit_list *newlist = NULL;
397 struct commit_list **p = &newlist;
398
399 while (list) {
400 struct commit_list *entry = list;
401 struct commit *commit = list->item;
402 struct object *obj = &commit->object;
403
404 list = list->next;
405 free(entry);
406
407 if (revs->max_age != -1 && (commit->date < revs->max_age))
408 obj->flags |= UNINTERESTING;
409 if (revs->unpacked && has_sha1_pack(obj->sha1))
410 obj->flags |= UNINTERESTING;
411 add_parents_to_list(revs, commit, &list);
412 if (obj->flags & UNINTERESTING) {
413 mark_parents_uninteresting(commit);
414 if (everybody_uninteresting(list))
415 break;
416 continue;
417 }
418 if (revs->min_age != -1 && (commit->date > revs->min_age))
419 continue;
420 p = &commit_list_insert(commit, p)->next;
421 }
422 if (revs->boundary) {
423 /* mark the ones that are on the result list first */
424 for (list = newlist; list; list = list->next) {
425 struct commit *commit = list->item;
426 commit->object.flags |= TMP_MARK;
427 }
428 for (list = newlist; list; list = list->next) {
429 struct commit *commit = list->item;
430 struct object *obj = &commit->object;
431 struct commit_list *parent;
432 if (obj->flags & UNINTERESTING)
433 continue;
434 for (parent = commit->parents;
435 parent;
436 parent = parent->next) {
437 struct commit *pcommit = parent->item;
438 if (!(pcommit->object.flags & UNINTERESTING))
439 continue;
440 pcommit->object.flags |= BOUNDARY;
441 if (pcommit->object.flags & TMP_MARK)
442 continue;
443 pcommit->object.flags |= TMP_MARK;
444 p = &commit_list_insert(pcommit, p)->next;
445 }
446 }
447 for (list = newlist; list; list = list->next) {
448 struct commit *commit = list->item;
449 commit->object.flags &= ~TMP_MARK;
450 }
451 }
452 revs->commits = newlist;
453 }
454
455 static void add_one_commit(struct commit *commit, struct rev_info *revs)
456 {
457 if (!commit || (commit->object.flags & SEEN))
458 return;
459 commit->object.flags |= SEEN;
460 commit_list_insert(commit, &revs->commits);
461 }
462
463 static int all_flags;
464 static struct rev_info *all_revs;
465
466 static int handle_one_ref(const char *path, const unsigned char *sha1)
467 {
468 struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
469 add_one_commit(commit, all_revs);
470 return 0;
471 }
472
473 static void handle_all(struct rev_info *revs, unsigned flags)
474 {
475 all_revs = revs;
476 all_flags = flags;
477 for_each_ref(handle_one_ref);
478 }
479
480 void init_revisions(struct rev_info *revs)
481 {
482 memset(revs, 0, sizeof(*revs));
483 revs->lifo = 1;
484 revs->dense = 1;
485 revs->prefix = setup_git_directory();
486 revs->max_age = -1;
487 revs->min_age = -1;
488 revs->max_count = -1;
489
490 revs->prune_fn = NULL;
491 revs->prune_data = NULL;
492
493 revs->topo_setter = topo_sort_default_setter;
494 revs->topo_getter = topo_sort_default_getter;
495 }
496
497 /*
498 * Parse revision information, filling in the "rev_info" structure,
499 * and removing the used arguments from the argument list.
500 *
501 * Returns the number of arguments left that weren't recognized
502 * (which are also moved to the head of the argument list)
503 */
504 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
505 {
506 int i, flags, seen_dashdash;
507 const char **unrecognized = argv + 1;
508 int left = 1;
509
510 init_revisions(revs);
511
512 /* First, search for "--" */
513 seen_dashdash = 0;
514 for (i = 1; i < argc; i++) {
515 const char *arg = argv[i];
516 if (strcmp(arg, "--"))
517 continue;
518 argv[i] = NULL;
519 argc = i;
520 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
521 seen_dashdash = 1;
522 break;
523 }
524
525 flags = 0;
526 for (i = 1; i < argc; i++) {
527 struct commit *commit;
528 const char *arg = argv[i];
529 unsigned char sha1[20];
530 char *dotdot;
531 int local_flags;
532
533 if (*arg == '-') {
534 if (!strncmp(arg, "--max-count=", 12)) {
535 revs->max_count = atoi(arg + 12);
536 continue;
537 }
538 /* accept -<digit>, like traditilnal "head" */
539 if ((*arg == '-') && isdigit(arg[1])) {
540 revs->max_count = atoi(arg + 1);
541 continue;
542 }
543 if (!strcmp(arg, "-n")) {
544 if (argc <= i + 1)
545 die("-n requires an argument");
546 revs->max_count = atoi(argv[++i]);
547 continue;
548 }
549 if (!strncmp(arg,"-n",2)) {
550 revs->max_count = atoi(arg + 2);
551 continue;
552 }
553 if (!strncmp(arg, "--max-age=", 10)) {
554 revs->max_age = atoi(arg + 10);
555 continue;
556 }
557 if (!strncmp(arg, "--since=", 8)) {
558 revs->max_age = approxidate(arg + 8);
559 continue;
560 }
561 if (!strncmp(arg, "--after=", 8)) {
562 revs->max_age = approxidate(arg + 8);
563 continue;
564 }
565 if (!strncmp(arg, "--min-age=", 10)) {
566 revs->min_age = atoi(arg + 10);
567 continue;
568 }
569 if (!strncmp(arg, "--before=", 9)) {
570 revs->min_age = approxidate(arg + 9);
571 continue;
572 }
573 if (!strncmp(arg, "--until=", 8)) {
574 revs->min_age = approxidate(arg + 8);
575 continue;
576 }
577 if (!strcmp(arg, "--all")) {
578 handle_all(revs, flags);
579 continue;
580 }
581 if (!strcmp(arg, "--not")) {
582 flags ^= UNINTERESTING;
583 continue;
584 }
585 if (!strcmp(arg, "--default")) {
586 if (++i >= argc)
587 die("bad --default argument");
588 def = argv[i];
589 continue;
590 }
591 if (!strcmp(arg, "--topo-order")) {
592 revs->topo_order = 1;
593 continue;
594 }
595 if (!strcmp(arg, "--date-order")) {
596 revs->lifo = 0;
597 revs->topo_order = 1;
598 continue;
599 }
600 if (!strcmp(arg, "--parents")) {
601 revs->parents = 1;
602 continue;
603 }
604 if (!strcmp(arg, "--dense")) {
605 revs->dense = 1;
606 continue;
607 }
608 if (!strcmp(arg, "--sparse")) {
609 revs->dense = 0;
610 continue;
611 }
612 if (!strcmp(arg, "--remove-empty")) {
613 revs->remove_empty_trees = 1;
614 continue;
615 }
616 if (!strcmp(arg, "--no-merges")) {
617 revs->no_merges = 1;
618 continue;
619 }
620 if (!strcmp(arg, "--boundary")) {
621 revs->boundary = 1;
622 continue;
623 }
624 if (!strcmp(arg, "--objects")) {
625 revs->tag_objects = 1;
626 revs->tree_objects = 1;
627 revs->blob_objects = 1;
628 continue;
629 }
630 if (!strcmp(arg, "--objects-edge")) {
631 revs->tag_objects = 1;
632 revs->tree_objects = 1;
633 revs->blob_objects = 1;
634 revs->edge_hint = 1;
635 continue;
636 }
637 if (!strcmp(arg, "--unpacked")) {
638 revs->unpacked = 1;
639 continue;
640 }
641 *unrecognized++ = arg;
642 left++;
643 continue;
644 }
645 dotdot = strstr(arg, "..");
646 if (dotdot) {
647 unsigned char from_sha1[20];
648 const char *next = dotdot + 2;
649 const char *this = arg;
650 *dotdot = 0;
651 if (!*next)
652 next = "HEAD";
653 if (dotdot == arg)
654 this = "HEAD";
655 if (!get_sha1(this, from_sha1) &&
656 !get_sha1(next, sha1)) {
657 struct commit *exclude;
658 struct commit *include;
659
660 exclude = get_commit_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
661 include = get_commit_reference(revs, next, sha1, flags);
662 if (!exclude || !include)
663 die("Invalid revision range %s..%s", arg, next);
664 add_one_commit(exclude, revs);
665 add_one_commit(include, revs);
666 continue;
667 }
668 *dotdot = '.';
669 }
670 local_flags = 0;
671 if (*arg == '^') {
672 local_flags = UNINTERESTING;
673 arg++;
674 }
675 if (get_sha1(arg, sha1) < 0) {
676 struct stat st;
677 int j;
678
679 if (seen_dashdash || local_flags)
680 die("bad revision '%s'", arg);
681
682 /* If we didn't have a "--", all filenames must exist */
683 for (j = i; j < argc; j++) {
684 if (lstat(argv[j], &st) < 0)
685 die("'%s': %s", argv[j], strerror(errno));
686 }
687 revs->prune_data = get_pathspec(revs->prefix, argv + i);
688 break;
689 }
690 commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
691 add_one_commit(commit, revs);
692 }
693 if (def && !revs->commits) {
694 unsigned char sha1[20];
695 struct commit *commit;
696 if (get_sha1(def, sha1) < 0)
697 die("bad default revision '%s'", def);
698 commit = get_commit_reference(revs, def, sha1, 0);
699 add_one_commit(commit, revs);
700 }
701
702 if (revs->topo_order || revs->unpacked)
703 revs->limited = 1;
704
705 if (revs->prune_data) {
706 diff_tree_setup_paths(revs->prune_data);
707 revs->prune_fn = try_to_simplify_commit;
708
709 /*
710 * If we fix up parent data, we currently cannot
711 * do that on-the-fly.
712 */
713 if (revs->parents)
714 revs->limited = 1;
715 }
716
717 return left;
718 }
719
720 void prepare_revision_walk(struct rev_info *revs)
721 {
722 sort_by_date(&revs->commits);
723 if (revs->limited)
724 limit_list(revs);
725 if (revs->topo_order)
726 sort_in_topological_order_fn(&revs->commits, revs->lifo,
727 revs->topo_setter,
728 revs->topo_getter);
729 }
730
731 static int rewrite_one(struct commit **pp)
732 {
733 for (;;) {
734 struct commit *p = *pp;
735 if (p->object.flags & (TREECHANGE | UNINTERESTING))
736 return 0;
737 if (!p->parents)
738 return -1;
739 *pp = p->parents->item;
740 }
741 }
742
743 static void rewrite_parents(struct commit *commit)
744 {
745 struct commit_list **pp = &commit->parents;
746 while (*pp) {
747 struct commit_list *parent = *pp;
748 if (rewrite_one(&parent->item) < 0) {
749 *pp = parent->next;
750 continue;
751 }
752 pp = &parent->next;
753 }
754 }
755
756 struct commit *get_revision(struct rev_info *revs)
757 {
758 struct commit_list *list = revs->commits;
759
760 if (!list)
761 return NULL;
762
763 /* Check the max_count ... */
764 switch (revs->max_count) {
765 case -1:
766 break;
767 case 0:
768 return NULL;
769 default:
770 revs->max_count--;
771 }
772
773 do {
774 struct commit *commit = revs->commits->item;
775
776 revs->commits = revs->commits->next;
777
778 /*
779 * If we haven't done the list limiting, we need to look at
780 * the parents here. We also need to do the date-based limiting
781 * that we'd otherwise have done in limit_list().
782 */
783 if (!revs->limited) {
784 if ((revs->unpacked &&
785 has_sha1_pack(commit->object.sha1)) ||
786 (revs->max_age != -1 &&
787 (commit->date < revs->max_age)))
788 continue;
789 add_parents_to_list(revs, commit, &revs->commits);
790 }
791 if (commit->object.flags & SHOWN)
792 continue;
793 if (!(commit->object.flags & BOUNDARY) &&
794 (commit->object.flags & UNINTERESTING))
795 continue;
796 if (revs->min_age != -1 && (commit->date > revs->min_age))
797 continue;
798 if (revs->no_merges &&
799 commit->parents && commit->parents->next)
800 continue;
801 if (revs->prune_fn && revs->dense) {
802 if (!(commit->object.flags & TREECHANGE))
803 continue;
804 if (revs->parents)
805 rewrite_parents(commit);
806 }
807 commit->object.flags |= SHOWN;
808 return commit;
809 } while (revs->commits);
810 return NULL;
811 }