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
10static 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
34struct 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
47static void mark_blob_uninteresting(struct blob *blob)
48{
49 if (blob->object.flags & UNINTERESTING)
50 return;
51 blob->object.flags |= UNINTERESTING;
52}
53
54void 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
79void 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
114static 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
119static 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
189static 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
202static int tree_difference = REV_TREE_SAME;
203
204static 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
227static 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
236static struct diff_options diff_opt = {
237 .recursive = 1,
238 .add_remove = file_add_remove,
239 .change = file_change,
240};
241
242int 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
254int 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", &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
278static 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 paths from
317 * this parent, so the parents of it is
318 * not interesting, but the difference between
319 * this parent and us still is interesting.
320 */
321 p->object.flags |= UNINTERESTING;
322 }
323 /* fallthrough */
324 case REV_TREE_DIFFERENT:
325 tree_changed = 1;
326 pp = &parent->next;
327 continue;
328 }
329 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
330 }
331 if (tree_changed)
332 commit->object.flags |= TREECHANGE;
333}
334
335static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
336{
337 struct commit_list *parent = commit->parents;
338
339 /*
340 * If the commit is uninteresting, don't try to
341 * prune parents - we want the maximal uninteresting
342 * set.
343 *
344 * Normally we haven't parsed the parent
345 * yet, so we won't have a parent of a parent
346 * here. However, it may turn out that we've
347 * reached this commit some other way (where it
348 * wasn't uninteresting), in which case we need
349 * to mark its parents recursively too..
350 */
351 if (commit->object.flags & UNINTERESTING) {
352 while (parent) {
353 struct commit *p = parent->item;
354 parent = parent->next;
355 parse_commit(p);
356 p->object.flags |= UNINTERESTING;
357 if (p->parents)
358 mark_parents_uninteresting(p);
359 if (p->object.flags & SEEN)
360 continue;
361 p->object.flags |= SEEN;
362 insert_by_date(p, list);
363 }
364 return;
365 }
366
367 /*
368 * Ok, the commit wasn't uninteresting. Try to
369 * simplify the commit history and find the parent
370 * that has no differences in the path set if one exists.
371 */
372 if (revs->prune_fn)
373 revs->prune_fn(revs, commit);
374
375 parent = commit->parents;
376 while (parent) {
377 struct commit *p = parent->item;
378
379 parent = parent->next;
380
381 parse_commit(p);
382 if (p->object.flags & SEEN)
383 continue;
384 p->object.flags |= SEEN;
385 insert_by_date(p, list);
386 }
387}
388
389static void limit_list(struct rev_info *revs)
390{
391 struct commit_list *list = revs->commits;
392 struct commit_list *newlist = NULL;
393 struct commit_list **p = &newlist;
394
395 while (list) {
396 struct commit_list *entry = list;
397 struct commit *commit = list->item;
398 struct object *obj = &commit->object;
399
400 list = list->next;
401 free(entry);
402
403 if (revs->max_age != -1 && (commit->date < revs->max_age))
404 obj->flags |= UNINTERESTING;
405 if (revs->unpacked && has_sha1_pack(obj->sha1))
406 obj->flags |= UNINTERESTING;
407 add_parents_to_list(revs, commit, &list);
408 if (obj->flags & UNINTERESTING) {
409 mark_parents_uninteresting(commit);
410 if (everybody_uninteresting(list))
411 break;
412 continue;
413 }
414 if (revs->min_age != -1 && (commit->date > revs->min_age))
415 continue;
416 p = &commit_list_insert(commit, p)->next;
417 }
418 revs->commits = newlist;
419}
420
421static void add_one_commit(struct commit *commit, struct rev_info *revs)
422{
423 if (!commit || (commit->object.flags & SEEN))
424 return;
425 commit->object.flags |= SEEN;
426 commit_list_insert(commit, &revs->commits);
427}
428
429static int all_flags;
430static struct rev_info *all_revs;
431
432static int handle_one_ref(const char *path, const unsigned char *sha1)
433{
434 struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
435 add_one_commit(commit, all_revs);
436 return 0;
437}
438
439static void handle_all(struct rev_info *revs, unsigned flags)
440{
441 all_revs = revs;
442 all_flags = flags;
443 for_each_ref(handle_one_ref);
444}
445
446void init_revisions(struct rev_info *revs)
447{
448 memset(revs, 0, sizeof(*revs));
449 revs->lifo = 1;
450 revs->dense = 1;
451 revs->prefix = setup_git_directory();
452 revs->max_age = -1;
453 revs->min_age = -1;
454 revs->max_count = -1;
455
456 revs->prune_fn = NULL;
457 revs->prune_data = NULL;
458
459 revs->topo_setter = topo_sort_default_setter;
460 revs->topo_getter = topo_sort_default_getter;
461}
462
463/*
464 * Parse revision information, filling in the "rev_info" structure,
465 * and removing the used arguments from the argument list.
466 *
467 * Returns the number of arguments left that weren't recognized
468 * (which are also moved to the head of the argument list)
469 */
470int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
471{
472 int i, flags, seen_dashdash;
473 const char **unrecognized = argv + 1;
474 int left = 1;
475
476 init_revisions(revs);
477
478 /* First, search for "--" */
479 seen_dashdash = 0;
480 for (i = 1; i < argc; i++) {
481 const char *arg = argv[i];
482 if (strcmp(arg, "--"))
483 continue;
484 argv[i] = NULL;
485 argc = i;
486 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
487 seen_dashdash = 1;
488 break;
489 }
490
491 flags = 0;
492 for (i = 1; i < argc; i++) {
493 struct commit *commit;
494 const char *arg = argv[i];
495 unsigned char sha1[20];
496 char *dotdot;
497 int local_flags;
498
499 if (*arg == '-') {
500 if (!strncmp(arg, "--max-count=", 12)) {
501 revs->max_count = atoi(arg + 12);
502 continue;
503 }
504 /* accept -<digit>, like traditilnal "head" */
505 if ((*arg == '-') && isdigit(arg[1])) {
506 revs->max_count = atoi(arg + 1);
507 continue;
508 }
509 if (!strcmp(arg, "-n")) {
510 if (argc <= i + 1)
511 die("-n requires an argument");
512 revs->max_count = atoi(argv[++i]);
513 continue;
514 }
515 if (!strncmp(arg,"-n",2)) {
516 revs->max_count = atoi(arg + 2);
517 continue;
518 }
519 if (!strncmp(arg, "--max-age=", 10)) {
520 revs->max_age = atoi(arg + 10);
521 revs->limited = 1;
522 continue;
523 }
524 if (!strncmp(arg, "--min-age=", 10)) {
525 revs->min_age = atoi(arg + 10);
526 revs->limited = 1;
527 continue;
528 }
529 if (!strncmp(arg, "--since=", 8)) {
530 revs->max_age = approxidate(arg + 8);
531 revs->limited = 1;
532 continue;
533 }
534 if (!strncmp(arg, "--after=", 8)) {
535 revs->max_age = approxidate(arg + 8);
536 revs->limited = 1;
537 continue;
538 }
539 if (!strncmp(arg, "--before=", 9)) {
540 revs->min_age = approxidate(arg + 9);
541 revs->limited = 1;
542 continue;
543 }
544 if (!strncmp(arg, "--until=", 8)) {
545 revs->min_age = approxidate(arg + 8);
546 revs->limited = 1;
547 continue;
548 }
549 if (!strcmp(arg, "--all")) {
550 handle_all(revs, flags);
551 continue;
552 }
553 if (!strcmp(arg, "--not")) {
554 flags ^= UNINTERESTING;
555 continue;
556 }
557 if (!strcmp(arg, "--default")) {
558 if (++i >= argc)
559 die("bad --default argument");
560 def = argv[i];
561 continue;
562 }
563 if (!strcmp(arg, "--topo-order")) {
564 revs->topo_order = 1;
565 revs->limited = 1;
566 continue;
567 }
568 if (!strcmp(arg, "--date-order")) {
569 revs->lifo = 0;
570 revs->topo_order = 1;
571 revs->limited = 1;
572 continue;
573 }
574 if (!strcmp(arg, "--dense")) {
575 revs->dense = 1;
576 continue;
577 }
578 if (!strcmp(arg, "--sparse")) {
579 revs->dense = 0;
580 continue;
581 }
582 if (!strcmp(arg, "--remove-empty")) {
583 revs->remove_empty_trees = 1;
584 continue;
585 }
586 if (!strncmp(arg, "--no-merges", 11)) {
587 revs->no_merges = 1;
588 continue;
589 }
590 if (!strcmp(arg, "--objects")) {
591 revs->tag_objects = 1;
592 revs->tree_objects = 1;
593 revs->blob_objects = 1;
594 continue;
595 }
596 if (!strcmp(arg, "--objects-edge")) {
597 revs->tag_objects = 1;
598 revs->tree_objects = 1;
599 revs->blob_objects = 1;
600 revs->edge_hint = 1;
601 continue;
602 }
603 if (!strcmp(arg, "--unpacked")) {
604 revs->unpacked = 1;
605 revs->limited = 1;
606 continue;
607 }
608 *unrecognized++ = arg;
609 left++;
610 continue;
611 }
612 dotdot = strstr(arg, "..");
613 if (dotdot) {
614 unsigned char from_sha1[20];
615 char *next = dotdot + 2;
616 *dotdot = 0;
617 if (!*next)
618 next = "HEAD";
619 if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
620 struct commit *exclude;
621 struct commit *include;
622
623 exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
624 include = get_commit_reference(revs, next, sha1, flags);
625 if (!exclude || !include)
626 die("Invalid revision range %s..%s", arg, next);
627 add_one_commit(exclude, revs);
628 add_one_commit(include, revs);
629 continue;
630 }
631 *dotdot = '.';
632 }
633 local_flags = 0;
634 if (*arg == '^') {
635 local_flags = UNINTERESTING;
636 arg++;
637 }
638 if (get_sha1(arg, sha1) < 0) {
639 struct stat st;
640 int j;
641
642 if (seen_dashdash || local_flags)
643 die("bad revision '%s'", arg);
644
645 /* If we didn't have a "--", all filenames must exist */
646 for (j = i; j < argc; j++) {
647 if (lstat(argv[j], &st) < 0)
648 die("'%s': %s", arg, strerror(errno));
649 }
650 revs->prune_data = get_pathspec(revs->prefix, argv + i);
651 break;
652 }
653 commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
654 add_one_commit(commit, revs);
655 }
656 if (def && !revs->commits) {
657 unsigned char sha1[20];
658 struct commit *commit;
659 if (get_sha1(def, sha1) < 0)
660 die("bad default revision '%s'", def);
661 commit = get_commit_reference(revs, def, sha1, 0);
662 add_one_commit(commit, revs);
663 }
664
665 if (revs->prune_data) {
666 diff_tree_setup_paths(revs->prune_data);
667 revs->prune_fn = try_to_simplify_commit;
668 revs->limited = 1;
669 }
670
671 return left;
672}
673
674void prepare_revision_walk(struct rev_info *revs)
675{
676 sort_by_date(&revs->commits);
677 if (revs->limited)
678 limit_list(revs);
679 if (revs->topo_order)
680 sort_in_topological_order_fn(&revs->commits, revs->lifo,
681 revs->topo_setter,
682 revs->topo_getter);
683}
684
685static int rewrite_one(struct commit **pp)
686{
687 for (;;) {
688 struct commit *p = *pp;
689 if (p->object.flags & (TREECHANGE | UNINTERESTING))
690 return 0;
691 if (!p->parents)
692 return -1;
693 *pp = p->parents->item;
694 }
695}
696
697static void rewrite_parents(struct commit *commit)
698{
699 struct commit_list **pp = &commit->parents;
700 while (*pp) {
701 struct commit_list *parent = *pp;
702 if (rewrite_one(&parent->item) < 0) {
703 *pp = parent->next;
704 continue;
705 }
706 pp = &parent->next;
707 }
708}
709
710struct commit *get_revision(struct rev_info *revs)
711{
712 struct commit_list *list = revs->commits;
713
714 if (!list)
715 return NULL;
716
717 /* Check the max_count ... */
718 switch (revs->max_count) {
719 case -1:
720 break;
721 case 0:
722 return NULL;
723 default:
724 revs->max_count--;
725 }
726
727 do {
728 struct commit *commit = revs->commits->item;
729
730 if (commit->object.flags & (UNINTERESTING|SHOWN))
731 goto next;
732 if (revs->min_age != -1 && (commit->date > revs->min_age))
733 goto next;
734 if (revs->max_age != -1 && (commit->date < revs->max_age))
735 return NULL;
736 if (revs->no_merges && commit->parents && commit->parents->next)
737 goto next;
738 if (revs->prune_fn && revs->dense) {
739 if (!(commit->object.flags & TREECHANGE))
740 goto next;
741 rewrite_parents(commit);
742 }
743 /* More to go? */
744 if (revs->max_count)
745 pop_most_recent_commit(&revs->commits, SEEN);
746 commit->object.flags |= SHOWN;
747 return commit;
748next:
749 pop_most_recent_commit(&revs->commits, SEEN);
750 } while (revs->commits);
751 return NULL;
752}