Merge git://git.kernel.org/pub/scm/gitk/gitk
[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", &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         revs->commits = newlist;
423 }
424
425 static void add_one_commit(struct commit *commit, struct rev_info *revs)
426 {
427         if (!commit || (commit->object.flags & SEEN))
428                 return;
429         commit->object.flags |= SEEN;
430         commit_list_insert(commit, &revs->commits);
431 }
432
433 static int all_flags;
434 static struct rev_info *all_revs;
435
436 static int handle_one_ref(const char *path, const unsigned char *sha1)
437 {
438         struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
439         add_one_commit(commit, all_revs);
440         return 0;
441 }
442
443 static void handle_all(struct rev_info *revs, unsigned flags)
444 {
445         all_revs = revs;
446         all_flags = flags;
447         for_each_ref(handle_one_ref);
448 }
449
450 void init_revisions(struct rev_info *revs)
451 {
452         memset(revs, 0, sizeof(*revs));
453         revs->lifo = 1;
454         revs->dense = 1;
455         revs->prefix = setup_git_directory();
456         revs->max_age = -1;
457         revs->min_age = -1;
458         revs->max_count = -1;
459
460         revs->prune_fn = NULL;
461         revs->prune_data = NULL;
462
463         revs->topo_setter = topo_sort_default_setter;
464         revs->topo_getter = topo_sort_default_getter;
465 }
466
467 /*
468  * Parse revision information, filling in the "rev_info" structure,
469  * and removing the used arguments from the argument list.
470  *
471  * Returns the number of arguments left that weren't recognized
472  * (which are also moved to the head of the argument list)
473  */
474 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
475 {
476         int i, flags, seen_dashdash;
477         const char **unrecognized = argv + 1;
478         int left = 1;
479
480         init_revisions(revs);
481
482         /* First, search for "--" */
483         seen_dashdash = 0;
484         for (i = 1; i < argc; i++) {
485                 const char *arg = argv[i];
486                 if (strcmp(arg, "--"))
487                         continue;
488                 argv[i] = NULL;
489                 argc = i;
490                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
491                 seen_dashdash = 1;
492                 break;
493         }
494
495         flags = 0;
496         for (i = 1; i < argc; i++) {
497                 struct commit *commit;
498                 const char *arg = argv[i];
499                 unsigned char sha1[20];
500                 char *dotdot;
501                 int local_flags;
502
503                 if (*arg == '-') {
504                         if (!strncmp(arg, "--max-count=", 12)) {
505                                 revs->max_count = atoi(arg + 12);
506                                 continue;
507                         }
508                         /* accept -<digit>, like traditilnal "head" */
509                         if ((*arg == '-') && isdigit(arg[1])) {
510                                 revs->max_count = atoi(arg + 1);
511                                 continue;
512                         }
513                         if (!strcmp(arg, "-n")) {
514                                 if (argc <= i + 1)
515                                         die("-n requires an argument");
516                                 revs->max_count = atoi(argv[++i]);
517                                 continue;
518                         }
519                         if (!strncmp(arg,"-n",2)) {
520                                 revs->max_count = atoi(arg + 2);
521                                 continue;
522                         }
523                         if (!strncmp(arg, "--max-age=", 10)) {
524                                 revs->max_age = atoi(arg + 10);
525                                 revs->limited = 1;
526                                 continue;
527                         }
528                         if (!strncmp(arg, "--min-age=", 10)) {
529                                 revs->min_age = atoi(arg + 10);
530                                 revs->limited = 1;
531                                 continue;
532                         }
533                         if (!strncmp(arg, "--since=", 8)) {
534                                 revs->max_age = approxidate(arg + 8);
535                                 revs->limited = 1;
536                                 continue;
537                         }
538                         if (!strncmp(arg, "--after=", 8)) {
539                                 revs->max_age = approxidate(arg + 8);
540                                 revs->limited = 1;
541                                 continue;
542                         }
543                         if (!strncmp(arg, "--before=", 9)) {
544                                 revs->min_age = approxidate(arg + 9);
545                                 revs->limited = 1;
546                                 continue;
547                         }
548                         if (!strncmp(arg, "--until=", 8)) {
549                                 revs->min_age = approxidate(arg + 8);
550                                 revs->limited = 1;
551                                 continue;
552                         }
553                         if (!strcmp(arg, "--all")) {
554                                 handle_all(revs, flags);
555                                 continue;
556                         }
557                         if (!strcmp(arg, "--not")) {
558                                 flags ^= UNINTERESTING;
559                                 continue;
560                         }
561                         if (!strcmp(arg, "--default")) {
562                                 if (++i >= argc)
563                                         die("bad --default argument");
564                                 def = argv[i];
565                                 continue;
566                         }
567                         if (!strcmp(arg, "--topo-order")) {
568                                 revs->topo_order = 1;
569                                 revs->limited = 1;
570                                 continue;
571                         }
572                         if (!strcmp(arg, "--date-order")) {
573                                 revs->lifo = 0;
574                                 revs->topo_order = 1;
575                                 revs->limited = 1;
576                                 continue;
577                         }
578                         if (!strcmp(arg, "--dense")) {
579                                 revs->dense = 1;
580                                 continue;
581                         }
582                         if (!strcmp(arg, "--sparse")) {
583                                 revs->dense = 0;
584                                 continue;
585                         }
586                         if (!strcmp(arg, "--remove-empty")) {
587                                 revs->remove_empty_trees = 1;
588                                 continue;
589                         }
590                         if (!strncmp(arg, "--no-merges", 11)) {
591                                 revs->no_merges = 1;
592                                 continue;
593                         }
594                         if (!strcmp(arg, "--objects")) {
595                                 revs->tag_objects = 1;
596                                 revs->tree_objects = 1;
597                                 revs->blob_objects = 1;
598                                 continue;
599                         }
600                         if (!strcmp(arg, "--objects-edge")) {
601                                 revs->tag_objects = 1;
602                                 revs->tree_objects = 1;
603                                 revs->blob_objects = 1;
604                                 revs->edge_hint = 1;
605                                 continue;
606                         }
607                         if (!strcmp(arg, "--unpacked")) {
608                                 revs->unpacked = 1;
609                                 revs->limited = 1;
610                                 continue;
611                         }
612                         *unrecognized++ = arg;
613                         left++;
614                         continue;
615                 }
616                 dotdot = strstr(arg, "..");
617                 if (dotdot) {
618                         unsigned char from_sha1[20];
619                         char *next = dotdot + 2;
620                         *dotdot = 0;
621                         if (!*next)
622                                 next = "HEAD";
623                         if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
624                                 struct commit *exclude;
625                                 struct commit *include;
626
627                                 exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
628                                 include = get_commit_reference(revs, next, sha1, flags);
629                                 if (!exclude || !include)
630                                         die("Invalid revision range %s..%s", arg, next);
631                                 add_one_commit(exclude, revs);
632                                 add_one_commit(include, revs);
633                                 continue;
634                         }
635                         *dotdot = '.';
636                 }
637                 local_flags = 0;
638                 if (*arg == '^') {
639                         local_flags = UNINTERESTING;
640                         arg++;
641                 }
642                 if (get_sha1(arg, sha1) < 0) {
643                         struct stat st;
644                         int j;
645
646                         if (seen_dashdash || local_flags)
647                                 die("bad revision '%s'", arg);
648
649                         /* If we didn't have a "--", all filenames must exist */
650                         for (j = i; j < argc; j++) {
651                                 if (lstat(argv[j], &st) < 0)
652                                         die("'%s': %s", arg, strerror(errno));
653                         }
654                         revs->prune_data = get_pathspec(revs->prefix, argv + i);
655                         break;
656                 }
657                 commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
658                 add_one_commit(commit, revs);
659         }
660         if (def && !revs->commits) {
661                 unsigned char sha1[20];
662                 struct commit *commit;
663                 if (get_sha1(def, sha1) < 0)
664                         die("bad default revision '%s'", def);
665                 commit = get_commit_reference(revs, def, sha1, 0);
666                 add_one_commit(commit, revs);
667         }
668
669         if (revs->prune_data) {
670                 diff_tree_setup_paths(revs->prune_data);
671                 revs->prune_fn = try_to_simplify_commit;
672                 revs->limited = 1;
673         }
674
675         return left;
676 }
677
678 void prepare_revision_walk(struct rev_info *revs)
679 {
680         sort_by_date(&revs->commits);
681         if (revs->limited)
682                 limit_list(revs);
683         if (revs->topo_order)
684                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
685                                              revs->topo_setter,
686                                              revs->topo_getter);
687 }
688
689 static int rewrite_one(struct commit **pp)
690 {
691         for (;;) {
692                 struct commit *p = *pp;
693                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
694                         return 0;
695                 if (!p->parents)
696                         return -1;
697                 *pp = p->parents->item;
698         }
699 }
700
701 static void rewrite_parents(struct commit *commit)
702 {
703         struct commit_list **pp = &commit->parents;
704         while (*pp) {
705                 struct commit_list *parent = *pp;
706                 if (rewrite_one(&parent->item) < 0) {
707                         *pp = parent->next;
708                         continue;
709                 }
710                 pp = &parent->next;
711         }
712 }
713
714 struct commit *get_revision(struct rev_info *revs)
715 {
716         struct commit_list *list = revs->commits;
717
718         if (!list)
719                 return NULL;
720
721         /* Check the max_count ... */
722         switch (revs->max_count) {
723         case -1:
724                 break;
725         case 0:
726                 return NULL;
727         default:
728                 revs->max_count--;
729         }
730
731         do {
732                 struct commit *commit = revs->commits->item;
733
734                 if (commit->object.flags & (UNINTERESTING|SHOWN))
735                         goto next;
736                 if (revs->min_age != -1 && (commit->date > revs->min_age))
737                         goto next;
738                 if (revs->max_age != -1 && (commit->date < revs->max_age))
739                         return NULL;
740                 if (revs->no_merges && commit->parents && commit->parents->next)
741                         goto next;
742                 if (revs->prune_fn && revs->dense) {
743                         if (!(commit->object.flags & TREECHANGE))
744                                 goto next;
745                         rewrite_parents(commit);
746                 }
747                 /* More to go? */
748                 if (revs->max_count)
749                         pop_most_recent_commit(&revs->commits, SEEN);
750                 commit->object.flags |= SHOWN;
751                 return commit;
752 next:
753                 pop_most_recent_commit(&revs->commits, SEEN);
754         } while (revs->commits);
755         return NULL;
756 }