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