diff-delta: bound hash list length to avoid O(m*n) behavior
[git/git.git] / revision.c
CommitLineData
ae563542
LT
1#include "cache.h"
2#include "tag.h"
3#include "blob.h"
4#include "tree.h"
5#include "commit.h"
a4a88b2b 6#include "diff.h"
ae563542
LT
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 commit->object.flags |= UNINTERESTING;
86
87 /*
88 * Normally we haven't parsed the parent
89 * yet, so we won't have a parent of a parent
90 * here. However, it may turn out that we've
91 * reached this commit some other way (where it
92 * wasn't uninteresting), in which case we need
93 * to mark its parents recursively too..
94 */
95 if (commit->parents)
96 mark_parents_uninteresting(commit);
97
98 /*
99 * A missing commit is ok iff its parent is marked
100 * uninteresting.
101 *
102 * We just mark such a thing parsed, so that when
103 * it is popped next time around, we won't be trying
104 * to parse it and get an error.
105 */
106 if (!has_sha1_file(commit->object.sha1))
107 commit->object.parsed = 1;
108 parents = parents->next;
109 }
110}
111
112static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
113{
114 add_object(obj, &revs->pending_objects, NULL, name);
115}
116
117static struct commit *get_commit_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
118{
119 struct object *object;
120
121 object = parse_object(sha1);
122 if (!object)
123 die("bad object %s", name);
124
125 /*
126 * Tag object? Look what it points to..
127 */
128 while (object->type == tag_type) {
129 struct tag *tag = (struct tag *) object;
130 object->flags |= flags;
131 if (revs->tag_objects && !(object->flags & UNINTERESTING))
132 add_pending_object(revs, object, tag->tag);
133 object = parse_object(tag->tagged->sha1);
134 if (!object)
135 die("bad object %s", sha1_to_hex(tag->tagged->sha1));
136 }
137
138 /*
139 * Commit object? Just return it, we'll do all the complex
140 * reachability crud.
141 */
142 if (object->type == commit_type) {
143 struct commit *commit = (struct commit *)object;
144 object->flags |= flags;
145 if (parse_commit(commit) < 0)
146 die("unable to parse commit %s", name);
d9a83684 147 if (flags & UNINTERESTING) {
ae563542 148 mark_parents_uninteresting(commit);
d9a83684
LT
149 revs->limited = 1;
150 }
ae563542
LT
151 return commit;
152 }
153
154 /*
155 * Tree object? Either mark it uniniteresting, or add it
156 * to the list of objects to look at later..
157 */
158 if (object->type == tree_type) {
159 struct tree *tree = (struct tree *)object;
160 if (!revs->tree_objects)
161 return NULL;
162 if (flags & UNINTERESTING) {
163 mark_tree_uninteresting(tree);
164 return NULL;
165 }
166 add_pending_object(revs, object, "");
167 return NULL;
168 }
169
170 /*
171 * Blob object? You know the drill by now..
172 */
173 if (object->type == blob_type) {
174 struct blob *blob = (struct blob *)object;
175 if (!revs->blob_objects)
176 return NULL;
177 if (flags & UNINTERESTING) {
178 mark_blob_uninteresting(blob);
179 return NULL;
180 }
181 add_pending_object(revs, object, "");
182 return NULL;
183 }
184 die("%s is unknown object", name);
185}
186
a4a88b2b
LT
187static int everybody_uninteresting(struct commit_list *orig)
188{
189 struct commit_list *list = orig;
190 while (list) {
191 struct commit *commit = list->item;
192 list = list->next;
193 if (commit->object.flags & UNINTERESTING)
194 continue;
195 return 0;
196 }
197 return 1;
198}
199
200#define TREE_SAME 0
201#define TREE_NEW 1
202#define TREE_DIFFERENT 2
203static int tree_difference = TREE_SAME;
204
205static void file_add_remove(struct diff_options *options,
206 int addremove, unsigned mode,
207 const unsigned char *sha1,
208 const char *base, const char *path)
209{
210 int diff = TREE_DIFFERENT;
211
212 /*
213 * Is it an add of a new file? It means that
214 * the old tree didn't have it at all, so we
215 * will turn "TREE_SAME" -> "TREE_NEW", but
216 * leave any "TREE_DIFFERENT" alone (and if
217 * it already was "TREE_NEW", we'll keep it
218 * "TREE_NEW" of course).
219 */
220 if (addremove == '+') {
221 diff = tree_difference;
222 if (diff != TREE_SAME)
223 return;
224 diff = TREE_NEW;
225 }
226 tree_difference = diff;
227}
228
229static void file_change(struct diff_options *options,
230 unsigned old_mode, unsigned new_mode,
231 const unsigned char *old_sha1,
232 const unsigned char *new_sha1,
233 const char *base, const char *path)
234{
235 tree_difference = TREE_DIFFERENT;
236}
237
238static struct diff_options diff_opt = {
239 .recursive = 1,
240 .add_remove = file_add_remove,
241 .change = file_change,
242};
243
244static int compare_tree(struct tree *t1, struct tree *t2)
245{
246 if (!t1)
247 return TREE_NEW;
248 if (!t2)
249 return TREE_DIFFERENT;
250 tree_difference = TREE_SAME;
251 if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
252 return TREE_DIFFERENT;
253 return tree_difference;
254}
255
256static int same_tree_as_empty(struct tree *t1)
257{
258 int retval;
259 void *tree;
260 struct tree_desc empty, real;
261
262 if (!t1)
263 return 0;
264
265 tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
266 if (!tree)
267 return 0;
268 real.buf = tree;
269
270 empty.buf = "";
271 empty.size = 0;
272
273 tree_difference = 0;
274 retval = diff_tree(&empty, &real, "", &diff_opt);
275 free(tree);
276
277 return retval >= 0 && !tree_difference;
278}
279
280static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
281{
282 struct commit_list **pp, *parent;
283
284 if (!commit->tree)
285 return;
286
287 if (!commit->parents) {
288 if (!same_tree_as_empty(commit->tree))
289 commit->object.flags |= TREECHANGE;
290 return;
291 }
292
293 pp = &commit->parents;
294 while ((parent = *pp) != NULL) {
295 struct commit *p = parent->item;
296
297 if (p->object.flags & UNINTERESTING) {
298 pp = &parent->next;
299 continue;
300 }
301
302 parse_commit(p);
303 switch (compare_tree(p->tree, commit->tree)) {
304 case TREE_SAME:
305 parent->next = NULL;
306 commit->parents = parent;
307 return;
308
309 case TREE_NEW:
310 if (revs->remove_empty_trees && same_tree_as_empty(p->tree)) {
311 *pp = parent->next;
312 continue;
313 }
314 /* fallthrough */
315 case TREE_DIFFERENT:
316 pp = &parent->next;
317 continue;
318 }
319 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
320 }
321 commit->object.flags |= TREECHANGE;
322}
323
324static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
325{
326 struct commit_list *parent = commit->parents;
327
328 /*
329 * If the commit is uninteresting, don't try to
330 * prune parents - we want the maximal uninteresting
331 * set.
332 *
333 * Normally we haven't parsed the parent
334 * yet, so we won't have a parent of a parent
335 * here. However, it may turn out that we've
336 * reached this commit some other way (where it
337 * wasn't uninteresting), in which case we need
338 * to mark its parents recursively too..
339 */
340 if (commit->object.flags & UNINTERESTING) {
341 while (parent) {
342 struct commit *p = parent->item;
343 parent = parent->next;
344 parse_commit(p);
345 p->object.flags |= UNINTERESTING;
346 if (p->parents)
347 mark_parents_uninteresting(p);
348 if (p->object.flags & SEEN)
349 continue;
350 p->object.flags |= SEEN;
351 insert_by_date(p, list);
352 }
353 return;
354 }
355
356 /*
357 * Ok, the commit wasn't uninteresting. Try to
358 * simplify the commit history and find the parent
359 * that has no differences in the path set if one exists.
360 */
361 if (revs->paths)
362 try_to_simplify_commit(revs, commit);
363
364 parent = commit->parents;
365 while (parent) {
366 struct commit *p = parent->item;
367
368 parent = parent->next;
369
370 parse_commit(p);
371 if (p->object.flags & SEEN)
372 continue;
373 p->object.flags |= SEEN;
374 insert_by_date(p, list);
375 }
376}
377
378static void limit_list(struct rev_info *revs)
379{
380 struct commit_list *list = revs->commits;
381 struct commit_list *newlist = NULL;
382 struct commit_list **p = &newlist;
383
765ac8ec
LT
384 if (revs->paths)
385 diff_tree_setup_paths(revs->paths);
386
a4a88b2b
LT
387 while (list) {
388 struct commit_list *entry = list;
389 struct commit *commit = list->item;
390 struct object *obj = &commit->object;
391
392 list = list->next;
393 free(entry);
394
395 if (revs->max_age != -1 && (commit->date < revs->max_age))
396 obj->flags |= UNINTERESTING;
397 if (revs->unpacked && has_sha1_pack(obj->sha1))
398 obj->flags |= UNINTERESTING;
399 add_parents_to_list(revs, commit, &list);
400 if (obj->flags & UNINTERESTING) {
401 mark_parents_uninteresting(commit);
402 if (everybody_uninteresting(list))
403 break;
404 continue;
405 }
406 if (revs->min_age != -1 && (commit->date > revs->min_age))
407 continue;
408 p = &commit_list_insert(commit, p)->next;
409 }
410 revs->commits = newlist;
411}
412
ae563542
LT
413static void add_one_commit(struct commit *commit, struct rev_info *revs)
414{
415 if (!commit || (commit->object.flags & SEEN))
416 return;
417 commit->object.flags |= SEEN;
418 commit_list_insert(commit, &revs->commits);
419}
420
421static int all_flags;
422static struct rev_info *all_revs;
423
424static int handle_one_ref(const char *path, const unsigned char *sha1)
425{
426 struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
427 add_one_commit(commit, all_revs);
428 return 0;
429}
430
431static void handle_all(struct rev_info *revs, unsigned flags)
432{
433 all_revs = revs;
434 all_flags = flags;
435 for_each_ref(handle_one_ref);
436}
437
438/*
439 * Parse revision information, filling in the "rev_info" structure,
440 * and removing the used arguments from the argument list.
441 *
765ac8ec
LT
442 * Returns the number of arguments left that weren't recognized
443 * (which are also moved to the head of the argument list)
ae563542 444 */
a4a88b2b 445int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
ae563542
LT
446{
447 int i, flags, seen_dashdash;
765ac8ec 448 const char **unrecognized = argv + 1;
ae563542
LT
449 int left = 1;
450
451 memset(revs, 0, sizeof(*revs));
452 revs->lifo = 1;
453 revs->dense = 1;
454 revs->prefix = setup_git_directory();
455 revs->max_age = -1;
456 revs->min_age = -1;
457 revs->max_count = -1;
458
459 /* First, search for "--" */
460 seen_dashdash = 0;
461 for (i = 1; i < argc; i++) {
462 const char *arg = argv[i];
463 if (strcmp(arg, "--"))
464 continue;
465 argv[i] = NULL;
466 argc = i;
467 revs->paths = get_pathspec(revs->prefix, argv + i + 1);
468 seen_dashdash = 1;
469 break;
470 }
471
472 flags = 0;
473 for (i = 1; i < argc; i++) {
474 struct commit *commit;
475 const char *arg = argv[i];
476 unsigned char sha1[20];
477 char *dotdot;
478 int local_flags;
479
480 if (*arg == '-') {
481 if (!strncmp(arg, "--max-count=", 12)) {
482 revs->max_count = atoi(arg + 12);
483 continue;
484 }
64bc6e3d
JH
485 /* accept -<digit>, like traditilnal "head" */
486 if ((*arg == '-') && isdigit(arg[1])) {
487 revs->max_count = atoi(arg + 1);
488 continue;
489 }
490 if (!strcmp(arg, "-n")) {
491 if (argc <= i + 1)
492 die("-n requires an argument");
493 revs->max_count = atoi(argv[++i]);
494 continue;
495 }
496 if (!strncmp(arg,"-n",2)) {
497 revs->max_count = atoi(arg + 2);
498 continue;
499 }
ae563542
LT
500 if (!strncmp(arg, "--max-age=", 10)) {
501 revs->max_age = atoi(arg + 10);
d9a83684 502 revs->limited = 1;
ae563542
LT
503 continue;
504 }
505 if (!strncmp(arg, "--min-age=", 10)) {
506 revs->min_age = atoi(arg + 10);
d9a83684 507 revs->limited = 1;
ae563542
LT
508 continue;
509 }
fd751667
JH
510 if (!strncmp(arg, "--since=", 8)) {
511 revs->max_age = approxidate(arg + 8);
512 revs->limited = 1;
513 continue;
514 }
515 if (!strncmp(arg, "--after=", 8)) {
516 revs->max_age = approxidate(arg + 8);
517 revs->limited = 1;
518 continue;
519 }
520 if (!strncmp(arg, "--before=", 9)) {
521 revs->min_age = approxidate(arg + 9);
522 revs->limited = 1;
523 continue;
524 }
525 if (!strncmp(arg, "--until=", 8)) {
526 revs->min_age = approxidate(arg + 8);
527 revs->limited = 1;
528 continue;
529 }
ae563542
LT
530 if (!strcmp(arg, "--all")) {
531 handle_all(revs, flags);
532 continue;
533 }
534 if (!strcmp(arg, "--not")) {
535 flags ^= UNINTERESTING;
536 continue;
537 }
538 if (!strcmp(arg, "--default")) {
539 if (++i >= argc)
540 die("bad --default argument");
541 def = argv[i];
542 continue;
543 }
544 if (!strcmp(arg, "--topo-order")) {
545 revs->topo_order = 1;
d9a83684 546 revs->limited = 1;
ae563542
LT
547 continue;
548 }
549 if (!strcmp(arg, "--date-order")) {
550 revs->lifo = 0;
551 revs->topo_order = 1;
d9a83684 552 revs->limited = 1;
ae563542
LT
553 continue;
554 }
555 if (!strcmp(arg, "--dense")) {
556 revs->dense = 1;
557 continue;
558 }
559 if (!strcmp(arg, "--sparse")) {
560 revs->dense = 0;
561 continue;
562 }
563 if (!strcmp(arg, "--remove-empty")) {
564 revs->remove_empty_trees = 1;
565 continue;
566 }
765ac8ec
LT
567 if (!strncmp(arg, "--no-merges", 11)) {
568 revs->no_merges = 1;
569 continue;
570 }
ae563542
LT
571 if (!strcmp(arg, "--objects")) {
572 revs->tag_objects = 1;
573 revs->tree_objects = 1;
574 revs->blob_objects = 1;
575 continue;
576 }
577 if (!strcmp(arg, "--objects-edge")) {
578 revs->tag_objects = 1;
579 revs->tree_objects = 1;
580 revs->blob_objects = 1;
581 revs->edge_hint = 1;
582 continue;
583 }
d9a83684
LT
584 if (!strcmp(arg, "--unpacked")) {
585 revs->unpacked = 1;
586 revs->limited = 1;
587 continue;
588 }
ae563542
LT
589 *unrecognized++ = arg;
590 left++;
591 continue;
592 }
593 dotdot = strstr(arg, "..");
594 if (dotdot) {
595 unsigned char from_sha1[20];
596 char *next = dotdot + 2;
597 *dotdot = 0;
598 if (!*next)
599 next = "HEAD";
600 if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
601 struct commit *exclude;
602 struct commit *include;
603
604 exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
605 include = get_commit_reference(revs, next, sha1, flags);
606 if (!exclude || !include)
607 die("Invalid revision range %s..%s", arg, next);
608 add_one_commit(exclude, revs);
609 add_one_commit(include, revs);
610 continue;
611 }
612 *dotdot = '.';
613 }
614 local_flags = 0;
615 if (*arg == '^') {
616 local_flags = UNINTERESTING;
617 arg++;
618 }
619 if (get_sha1(arg, sha1) < 0) {
620 struct stat st;
621 int j;
622
623 if (seen_dashdash || local_flags)
624 die("bad revision '%s'", arg);
625
626 /* If we didn't have a "--", all filenames must exist */
627 for (j = i; j < argc; j++) {
628 if (lstat(argv[j], &st) < 0)
629 die("'%s': %s", arg, strerror(errno));
630 }
631 revs->paths = get_pathspec(revs->prefix, argv + i);
632 break;
633 }
634 commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
635 add_one_commit(commit, revs);
636 }
637 if (def && !revs->commits) {
638 unsigned char sha1[20];
639 struct commit *commit;
640 if (get_sha1(def, sha1) < 0)
641 die("bad default revision '%s'", def);
642 commit = get_commit_reference(revs, def, sha1, 0);
643 add_one_commit(commit, revs);
644 }
d9a83684
LT
645 if (revs->paths)
646 revs->limited = 1;
ae563542
LT
647 return left;
648}
a4a88b2b
LT
649
650void prepare_revision_walk(struct rev_info *revs)
651{
a4a88b2b
LT
652 sort_by_date(&revs->commits);
653 if (revs->limited)
654 limit_list(revs);
655 if (revs->topo_order)
656 sort_in_topological_order(&revs->commits, revs->lifo);
657}
658
765ac8ec
LT
659static int rewrite_one(struct commit **pp)
660{
661 for (;;) {
662 struct commit *p = *pp;
663 if (p->object.flags & (TREECHANGE | UNINTERESTING))
664 return 0;
665 if (!p->parents)
666 return -1;
667 *pp = p->parents->item;
668 }
669}
670
671static void rewrite_parents(struct commit *commit)
672{
673 struct commit_list **pp = &commit->parents;
674 while (*pp) {
675 struct commit_list *parent = *pp;
676 if (rewrite_one(&parent->item) < 0) {
677 *pp = parent->next;
678 continue;
679 }
680 pp = &parent->next;
681 }
682}
683
a4a88b2b
LT
684struct commit *get_revision(struct rev_info *revs)
685{
765ac8ec 686 struct commit_list *list = revs->commits;
765ac8ec
LT
687
688 if (!list)
a4a88b2b 689 return NULL;
a4a88b2b 690
765ac8ec 691 /* Check the max_count ... */
765ac8ec
LT
692 switch (revs->max_count) {
693 case -1:
694 break;
695 case 0:
696 return NULL;
697 default:
698 revs->max_count--;
699 }
a4a88b2b 700
765ac8ec 701 do {
ea5ed3ab
LT
702 struct commit *commit = revs->commits->item;
703
765ac8ec 704 if (commit->object.flags & (UNINTERESTING|SHOWN))
ea5ed3ab 705 goto next;
765ac8ec 706 if (revs->min_age != -1 && (commit->date > revs->min_age))
ea5ed3ab 707 goto next;
765ac8ec
LT
708 if (revs->max_age != -1 && (commit->date < revs->max_age))
709 return NULL;
710 if (revs->no_merges && commit->parents && commit->parents->next)
ea5ed3ab 711 goto next;
765ac8ec
LT
712 if (revs->paths && revs->dense) {
713 if (!(commit->object.flags & TREECHANGE))
ea5ed3ab 714 goto next;
765ac8ec
LT
715 rewrite_parents(commit);
716 }
ea5ed3ab
LT
717 /* More to go? */
718 if (revs->max_count)
719 pop_most_recent_commit(&revs->commits, SEEN);
765ac8ec
LT
720 commit->object.flags |= SHOWN;
721 return commit;
ea5ed3ab
LT
722next:
723 pop_most_recent_commit(&revs->commits, SEEN);
765ac8ec
LT
724 } while (revs->commits);
725 return NULL;
726}