Merge branch 'git-p4' of git://repo.or.cz/git/git-p4
[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 #include "grep.h"
10 #include "reflog-walk.h"
11 #include "patch-ids.h"
12
13 volatile show_early_output_fn_t show_early_output;
14
15 static char *path_name(struct name_path *path, const char *name)
16 {
17         struct name_path *p;
18         char *n, *m;
19         int nlen = strlen(name);
20         int len = nlen + 1;
21
22         for (p = path; p; p = p->up) {
23                 if (p->elem_len)
24                         len += p->elem_len + 1;
25         }
26         n = xmalloc(len);
27         m = n + len - (nlen + 1);
28         strcpy(m, name);
29         for (p = path; p; p = p->up) {
30                 if (p->elem_len) {
31                         m -= p->elem_len + 1;
32                         memcpy(m, p->elem, p->elem_len);
33                         m[p->elem_len] = '/';
34                 }
35         }
36         return n;
37 }
38
39 void add_object(struct object *obj,
40                 struct object_array *p,
41                 struct name_path *path,
42                 const char *name)
43 {
44         add_object_array(obj, path_name(path, name), p);
45 }
46
47 static void mark_blob_uninteresting(struct blob *blob)
48 {
49         if (!blob)
50                 return;
51         if (blob->object.flags & UNINTERESTING)
52                 return;
53         blob->object.flags |= UNINTERESTING;
54 }
55
56 void mark_tree_uninteresting(struct tree *tree)
57 {
58         struct tree_desc desc;
59         struct name_entry entry;
60         struct object *obj = &tree->object;
61
62         if (!tree)
63                 return;
64         if (obj->flags & UNINTERESTING)
65                 return;
66         obj->flags |= UNINTERESTING;
67         if (!has_sha1_file(obj->sha1))
68                 return;
69         if (parse_tree(tree) < 0)
70                 die("bad tree %s", sha1_to_hex(obj->sha1));
71
72         init_tree_desc(&desc, tree->buffer, tree->size);
73         while (tree_entry(&desc, &entry)) {
74                 switch (object_type(entry.mode)) {
75                 case OBJ_TREE:
76                         mark_tree_uninteresting(lookup_tree(entry.sha1));
77                         break;
78                 case OBJ_BLOB:
79                         mark_blob_uninteresting(lookup_blob(entry.sha1));
80                         break;
81                 default:
82                         /* Subproject commit - not in this repository */
83                         break;
84                 }
85         }
86
87         /*
88          * We don't care about the tree any more
89          * after it has been marked uninteresting.
90          */
91         free(tree->buffer);
92         tree->buffer = NULL;
93 }
94
95 void mark_parents_uninteresting(struct commit *commit)
96 {
97         struct commit_list *parents = commit->parents;
98
99         while (parents) {
100                 struct commit *commit = parents->item;
101                 if (!(commit->object.flags & UNINTERESTING)) {
102                         commit->object.flags |= UNINTERESTING;
103
104                         /*
105                          * Normally we haven't parsed the parent
106                          * yet, so we won't have a parent of a parent
107                          * here. However, it may turn out that we've
108                          * reached this commit some other way (where it
109                          * wasn't uninteresting), in which case we need
110                          * to mark its parents recursively too..
111                          */
112                         if (commit->parents)
113                                 mark_parents_uninteresting(commit);
114                 }
115
116                 /*
117                  * A missing commit is ok iff its parent is marked
118                  * uninteresting.
119                  *
120                  * We just mark such a thing parsed, so that when
121                  * it is popped next time around, we won't be trying
122                  * to parse it and get an error.
123                  */
124                 if (!has_sha1_file(commit->object.sha1))
125                         commit->object.parsed = 1;
126                 parents = parents->next;
127         }
128 }
129
130 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
131 {
132         if (revs->no_walk && (obj->flags & UNINTERESTING))
133                 die("object ranges do not make sense when not walking revisions");
134         if (revs->reflog_info && obj->type == OBJ_COMMIT &&
135                         add_reflog_for_walk(revs->reflog_info,
136                                 (struct commit *)obj, name))
137                 return;
138         add_object_array_with_mode(obj, name, &revs->pending, mode);
139 }
140
141 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
142 {
143         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
144 }
145
146 void add_head_to_pending(struct rev_info *revs)
147 {
148         unsigned char sha1[20];
149         struct object *obj;
150         if (get_sha1("HEAD", sha1))
151                 return;
152         obj = parse_object(sha1);
153         if (!obj)
154                 return;
155         add_pending_object(revs, obj, "HEAD");
156 }
157
158 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
159 {
160         struct object *object;
161
162         object = parse_object(sha1);
163         if (!object)
164                 die("bad object %s", name);
165         object->flags |= flags;
166         return object;
167 }
168
169 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
170 {
171         unsigned long flags = object->flags;
172
173         /*
174          * Tag object? Look what it points to..
175          */
176         while (object->type == OBJ_TAG) {
177                 struct tag *tag = (struct tag *) object;
178                 if (revs->tag_objects && !(flags & UNINTERESTING))
179                         add_pending_object(revs, object, tag->tag);
180                 if (!tag->tagged)
181                         die("bad tag");
182                 object = parse_object(tag->tagged->sha1);
183                 if (!object)
184                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
185         }
186
187         /*
188          * Commit object? Just return it, we'll do all the complex
189          * reachability crud.
190          */
191         if (object->type == OBJ_COMMIT) {
192                 struct commit *commit = (struct commit *)object;
193                 if (parse_commit(commit) < 0)
194                         die("unable to parse commit %s", name);
195                 if (flags & UNINTERESTING) {
196                         commit->object.flags |= UNINTERESTING;
197                         mark_parents_uninteresting(commit);
198                         revs->limited = 1;
199                 }
200                 return commit;
201         }
202
203         /*
204          * Tree object? Either mark it uniniteresting, or add it
205          * to the list of objects to look at later..
206          */
207         if (object->type == OBJ_TREE) {
208                 struct tree *tree = (struct tree *)object;
209                 if (!revs->tree_objects)
210                         return NULL;
211                 if (flags & UNINTERESTING) {
212                         mark_tree_uninteresting(tree);
213                         return NULL;
214                 }
215                 add_pending_object(revs, object, "");
216                 return NULL;
217         }
218
219         /*
220          * Blob object? You know the drill by now..
221          */
222         if (object->type == OBJ_BLOB) {
223                 struct blob *blob = (struct blob *)object;
224                 if (!revs->blob_objects)
225                         return NULL;
226                 if (flags & UNINTERESTING) {
227                         mark_blob_uninteresting(blob);
228                         return NULL;
229                 }
230                 add_pending_object(revs, object, "");
231                 return NULL;
232         }
233         die("%s is unknown object", name);
234 }
235
236 static int everybody_uninteresting(struct commit_list *orig)
237 {
238         struct commit_list *list = orig;
239         while (list) {
240                 struct commit *commit = list->item;
241                 list = list->next;
242                 if (commit->object.flags & UNINTERESTING)
243                         continue;
244                 return 0;
245         }
246         return 1;
247 }
248
249 /*
250  * The goal is to get REV_TREE_NEW as the result only if the
251  * diff consists of all '+' (and no other changes), and
252  * REV_TREE_DIFFERENT otherwise (of course if the trees are
253  * the same we want REV_TREE_SAME).  That means that once we
254  * get to REV_TREE_DIFFERENT, we do not have to look any further.
255  */
256 static int tree_difference = REV_TREE_SAME;
257
258 static void file_add_remove(struct diff_options *options,
259                     int addremove, unsigned mode,
260                     const unsigned char *sha1,
261                     const char *base, const char *path)
262 {
263         int diff = REV_TREE_DIFFERENT;
264
265         /*
266          * Is it an add of a new file? It means that the old tree
267          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
268          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
269          * (and if it already was "REV_TREE_NEW", we'll keep it
270          * "REV_TREE_NEW" of course).
271          */
272         if (addremove == '+') {
273                 diff = tree_difference;
274                 if (diff != REV_TREE_SAME)
275                         return;
276                 diff = REV_TREE_NEW;
277         }
278         tree_difference = diff;
279         if (tree_difference == REV_TREE_DIFFERENT)
280                 DIFF_OPT_SET(options, HAS_CHANGES);
281 }
282
283 static void file_change(struct diff_options *options,
284                  unsigned old_mode, unsigned new_mode,
285                  const unsigned char *old_sha1,
286                  const unsigned char *new_sha1,
287                  const char *base, const char *path)
288 {
289         tree_difference = REV_TREE_DIFFERENT;
290         DIFF_OPT_SET(options, HAS_CHANGES);
291 }
292
293 static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
294 {
295         if (!t1)
296                 return REV_TREE_NEW;
297         if (!t2)
298                 return REV_TREE_DIFFERENT;
299         tree_difference = REV_TREE_SAME;
300         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
301         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
302                            &revs->pruning) < 0)
303                 return REV_TREE_DIFFERENT;
304         return tree_difference;
305 }
306
307 static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
308 {
309         int retval;
310         void *tree;
311         unsigned long size;
312         struct tree_desc empty, real;
313
314         if (!t1)
315                 return 0;
316
317         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
318         if (!tree)
319                 return 0;
320         init_tree_desc(&real, tree, size);
321         init_tree_desc(&empty, "", 0);
322
323         tree_difference = REV_TREE_SAME;
324         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
325         retval = diff_tree(&empty, &real, "", &revs->pruning);
326         free(tree);
327
328         return retval >= 0 && (tree_difference == REV_TREE_SAME);
329 }
330
331 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
332 {
333         struct commit_list **pp, *parent;
334         int tree_changed = 0, tree_same = 0;
335
336         /*
337          * If we don't do pruning, everything is interesting
338          */
339         if (!revs->prune)
340                 return;
341
342         if (!commit->tree)
343                 return;
344
345         if (!commit->parents) {
346                 if (rev_same_tree_as_empty(revs, commit->tree))
347                         commit->object.flags |= TREESAME;
348                 return;
349         }
350
351         /*
352          * Normal non-merge commit? If we don't want to make the
353          * history dense, we consider it always to be a change..
354          */
355         if (!revs->dense && !commit->parents->next)
356                 return;
357
358         pp = &commit->parents;
359         while ((parent = *pp) != NULL) {
360                 struct commit *p = parent->item;
361
362                 if (parse_commit(p) < 0)
363                         die("cannot simplify commit %s (because of %s)",
364                             sha1_to_hex(commit->object.sha1),
365                             sha1_to_hex(p->object.sha1));
366                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
367                 case REV_TREE_SAME:
368                         tree_same = 1;
369                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
370                                 /* Even if a merge with an uninteresting
371                                  * side branch brought the entire change
372                                  * we are interested in, we do not want
373                                  * to lose the other branches of this
374                                  * merge, so we just keep going.
375                                  */
376                                 pp = &parent->next;
377                                 continue;
378                         }
379                         parent->next = NULL;
380                         commit->parents = parent;
381                         commit->object.flags |= TREESAME;
382                         return;
383
384                 case REV_TREE_NEW:
385                         if (revs->remove_empty_trees &&
386                             rev_same_tree_as_empty(revs, p->tree)) {
387                                 /* We are adding all the specified
388                                  * paths from this parent, so the
389                                  * history beyond this parent is not
390                                  * interesting.  Remove its parents
391                                  * (they are grandparents for us).
392                                  * IOW, we pretend this parent is a
393                                  * "root" commit.
394                                  */
395                                 if (parse_commit(p) < 0)
396                                         die("cannot simplify commit %s (invalid %s)",
397                                             sha1_to_hex(commit->object.sha1),
398                                             sha1_to_hex(p->object.sha1));
399                                 p->parents = NULL;
400                         }
401                 /* fallthrough */
402                 case REV_TREE_DIFFERENT:
403                         tree_changed = 1;
404                         pp = &parent->next;
405                         continue;
406                 }
407                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
408         }
409         if (tree_changed && !tree_same)
410                 return;
411         commit->object.flags |= TREESAME;
412 }
413
414 static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
415 {
416         struct commit_list *parent = commit->parents;
417         unsigned left_flag;
418         int add, rest;
419
420         if (commit->object.flags & ADDED)
421                 return 0;
422         commit->object.flags |= ADDED;
423
424         /*
425          * If the commit is uninteresting, don't try to
426          * prune parents - we want the maximal uninteresting
427          * set.
428          *
429          * Normally we haven't parsed the parent
430          * yet, so we won't have a parent of a parent
431          * here. However, it may turn out that we've
432          * reached this commit some other way (where it
433          * wasn't uninteresting), in which case we need
434          * to mark its parents recursively too..
435          */
436         if (commit->object.flags & UNINTERESTING) {
437                 while (parent) {
438                         struct commit *p = parent->item;
439                         parent = parent->next;
440                         if (parse_commit(p) < 0)
441                                 return -1;
442                         p->object.flags |= UNINTERESTING;
443                         if (p->parents)
444                                 mark_parents_uninteresting(p);
445                         if (p->object.flags & SEEN)
446                                 continue;
447                         p->object.flags |= SEEN;
448                         insert_by_date(p, list);
449                 }
450                 return 0;
451         }
452
453         /*
454          * Ok, the commit wasn't uninteresting. Try to
455          * simplify the commit history and find the parent
456          * that has no differences in the path set if one exists.
457          */
458         try_to_simplify_commit(revs, commit);
459
460         if (revs->no_walk)
461                 return 0;
462
463         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
464
465         rest = !revs->first_parent_only;
466         for (parent = commit->parents, add = 1; parent; add = rest) {
467                 struct commit *p = parent->item;
468
469                 parent = parent->next;
470                 if (parse_commit(p) < 0)
471                         return -1;
472                 p->object.flags |= left_flag;
473                 if (p->object.flags & SEEN)
474                         continue;
475                 p->object.flags |= SEEN;
476                 if (add)
477                         insert_by_date(p, list);
478         }
479         return 0;
480 }
481
482 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
483 {
484         struct commit_list *p;
485         int left_count = 0, right_count = 0;
486         int left_first;
487         struct patch_ids ids;
488
489         /* First count the commits on the left and on the right */
490         for (p = list; p; p = p->next) {
491                 struct commit *commit = p->item;
492                 unsigned flags = commit->object.flags;
493                 if (flags & BOUNDARY)
494                         ;
495                 else if (flags & SYMMETRIC_LEFT)
496                         left_count++;
497                 else
498                         right_count++;
499         }
500
501         left_first = left_count < right_count;
502         init_patch_ids(&ids);
503         if (revs->diffopt.nr_paths) {
504                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
505                 ids.diffopts.paths = revs->diffopt.paths;
506                 ids.diffopts.pathlens = revs->diffopt.pathlens;
507         }
508
509         /* Compute patch-ids for one side */
510         for (p = list; p; p = p->next) {
511                 struct commit *commit = p->item;
512                 unsigned flags = commit->object.flags;
513
514                 if (flags & BOUNDARY)
515                         continue;
516                 /*
517                  * If we have fewer left, left_first is set and we omit
518                  * commits on the right branch in this loop.  If we have
519                  * fewer right, we skip the left ones.
520                  */
521                 if (left_first != !!(flags & SYMMETRIC_LEFT))
522                         continue;
523                 commit->util = add_commit_patch_id(commit, &ids);
524         }
525
526         /* Check the other side */
527         for (p = list; p; p = p->next) {
528                 struct commit *commit = p->item;
529                 struct patch_id *id;
530                 unsigned flags = commit->object.flags;
531
532                 if (flags & BOUNDARY)
533                         continue;
534                 /*
535                  * If we have fewer left, left_first is set and we omit
536                  * commits on the left branch in this loop.
537                  */
538                 if (left_first == !!(flags & SYMMETRIC_LEFT))
539                         continue;
540
541                 /*
542                  * Have we seen the same patch id?
543                  */
544                 id = has_commit_patch_id(commit, &ids);
545                 if (!id)
546                         continue;
547                 id->seen = 1;
548                 commit->object.flags |= SHOWN;
549         }
550
551         /* Now check the original side for seen ones */
552         for (p = list; p; p = p->next) {
553                 struct commit *commit = p->item;
554                 struct patch_id *ent;
555
556                 ent = commit->util;
557                 if (!ent)
558                         continue;
559                 if (ent->seen)
560                         commit->object.flags |= SHOWN;
561                 commit->util = NULL;
562         }
563
564         free_patch_ids(&ids);
565 }
566
567 static void add_to_list(struct commit_list **p, struct commit *commit, struct commit_list *n)
568 {
569         p = &commit_list_insert(commit, p)->next;
570         *p = n;
571 }
572
573 static int limit_list(struct rev_info *revs)
574 {
575         struct commit_list *list = revs->commits;
576         struct commit_list *newlist = NULL;
577         struct commit_list **p = &newlist;
578
579         while (list) {
580                 struct commit_list *entry = list;
581                 struct commit *commit = list->item;
582                 struct object *obj = &commit->object;
583                 show_early_output_fn_t show;
584
585                 list = list->next;
586                 free(entry);
587
588                 if (revs->max_age != -1 && (commit->date < revs->max_age))
589                         obj->flags |= UNINTERESTING;
590                 if (add_parents_to_list(revs, commit, &list) < 0)
591                         return -1;
592                 if (obj->flags & UNINTERESTING) {
593                         mark_parents_uninteresting(commit);
594                         if (everybody_uninteresting(list)) {
595                                 if (revs->show_all)
596                                         add_to_list(p, commit, list);
597                                 break;
598                         }
599                         if (!revs->show_all)
600                                 continue;
601                 }
602                 if (revs->min_age != -1 && (commit->date > revs->min_age))
603                         continue;
604                 p = &commit_list_insert(commit, p)->next;
605
606                 show = show_early_output;
607                 if (!show)
608                         continue;
609
610                 show(revs, newlist);
611                 show_early_output = NULL;
612         }
613         if (revs->cherry_pick)
614                 cherry_pick_list(newlist, revs);
615
616         revs->commits = newlist;
617         return 0;
618 }
619
620 struct all_refs_cb {
621         int all_flags;
622         int warned_bad_reflog;
623         struct rev_info *all_revs;
624         const char *name_for_errormsg;
625 };
626
627 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
628 {
629         struct all_refs_cb *cb = cb_data;
630         struct object *object = get_reference(cb->all_revs, path, sha1,
631                                               cb->all_flags);
632         add_pending_object(cb->all_revs, object, path);
633         return 0;
634 }
635
636 static void handle_all(struct rev_info *revs, unsigned flags)
637 {
638         struct all_refs_cb cb;
639         cb.all_revs = revs;
640         cb.all_flags = flags;
641         for_each_ref(handle_one_ref, &cb);
642 }
643
644 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
645 {
646         struct all_refs_cb *cb = cb_data;
647         if (!is_null_sha1(sha1)) {
648                 struct object *o = parse_object(sha1);
649                 if (o) {
650                         o->flags |= cb->all_flags;
651                         add_pending_object(cb->all_revs, o, "");
652                 }
653                 else if (!cb->warned_bad_reflog) {
654                         warning("reflog of '%s' references pruned commits",
655                                 cb->name_for_errormsg);
656                         cb->warned_bad_reflog = 1;
657                 }
658         }
659 }
660
661 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
662                 const char *email, unsigned long timestamp, int tz,
663                 const char *message, void *cb_data)
664 {
665         handle_one_reflog_commit(osha1, cb_data);
666         handle_one_reflog_commit(nsha1, cb_data);
667         return 0;
668 }
669
670 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
671 {
672         struct all_refs_cb *cb = cb_data;
673         cb->warned_bad_reflog = 0;
674         cb->name_for_errormsg = path;
675         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
676         return 0;
677 }
678
679 static void handle_reflog(struct rev_info *revs, unsigned flags)
680 {
681         struct all_refs_cb cb;
682         cb.all_revs = revs;
683         cb.all_flags = flags;
684         for_each_reflog(handle_one_reflog, &cb);
685 }
686
687 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
688 {
689         unsigned char sha1[20];
690         struct object *it;
691         struct commit *commit;
692         struct commit_list *parents;
693
694         if (*arg == '^') {
695                 flags ^= UNINTERESTING;
696                 arg++;
697         }
698         if (get_sha1(arg, sha1))
699                 return 0;
700         while (1) {
701                 it = get_reference(revs, arg, sha1, 0);
702                 if (it->type != OBJ_TAG)
703                         break;
704                 if (!((struct tag*)it)->tagged)
705                         return 0;
706                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
707         }
708         if (it->type != OBJ_COMMIT)
709                 return 0;
710         commit = (struct commit *)it;
711         for (parents = commit->parents; parents; parents = parents->next) {
712                 it = &parents->item->object;
713                 it->flags |= flags;
714                 add_pending_object(revs, it, arg);
715         }
716         return 1;
717 }
718
719 void init_revisions(struct rev_info *revs, const char *prefix)
720 {
721         memset(revs, 0, sizeof(*revs));
722
723         revs->abbrev = DEFAULT_ABBREV;
724         revs->ignore_merges = 1;
725         revs->simplify_history = 1;
726         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
727         DIFF_OPT_SET(&revs->pruning, QUIET);
728         revs->pruning.add_remove = file_add_remove;
729         revs->pruning.change = file_change;
730         revs->lifo = 1;
731         revs->dense = 1;
732         revs->prefix = prefix;
733         revs->max_age = -1;
734         revs->min_age = -1;
735         revs->skip_count = -1;
736         revs->max_count = -1;
737
738         revs->commit_format = CMIT_FMT_DEFAULT;
739
740         diff_setup(&revs->diffopt);
741         if (prefix && !revs->diffopt.prefix) {
742                 revs->diffopt.prefix = prefix;
743                 revs->diffopt.prefix_length = strlen(prefix);
744         }
745 }
746
747 static void add_pending_commit_list(struct rev_info *revs,
748                                     struct commit_list *commit_list,
749                                     unsigned int flags)
750 {
751         while (commit_list) {
752                 struct object *object = &commit_list->item->object;
753                 object->flags |= flags;
754                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
755                 commit_list = commit_list->next;
756         }
757 }
758
759 static void prepare_show_merge(struct rev_info *revs)
760 {
761         struct commit_list *bases;
762         struct commit *head, *other;
763         unsigned char sha1[20];
764         const char **prune = NULL;
765         int i, prune_num = 1; /* counting terminating NULL */
766
767         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
768                 die("--merge without HEAD?");
769         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
770                 die("--merge without MERGE_HEAD?");
771         add_pending_object(revs, &head->object, "HEAD");
772         add_pending_object(revs, &other->object, "MERGE_HEAD");
773         bases = get_merge_bases(head, other, 1);
774         while (bases) {
775                 struct commit *it = bases->item;
776                 struct commit_list *n = bases->next;
777                 free(bases);
778                 bases = n;
779                 it->object.flags |= UNINTERESTING;
780                 add_pending_object(revs, &it->object, "(merge-base)");
781         }
782
783         if (!active_nr)
784                 read_cache();
785         for (i = 0; i < active_nr; i++) {
786                 struct cache_entry *ce = active_cache[i];
787                 if (!ce_stage(ce))
788                         continue;
789                 if (ce_path_match(ce, revs->prune_data)) {
790                         prune_num++;
791                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
792                         prune[prune_num-2] = ce->name;
793                         prune[prune_num-1] = NULL;
794                 }
795                 while ((i+1 < active_nr) &&
796                        ce_same_name(ce, active_cache[i+1]))
797                         i++;
798         }
799         revs->prune_data = prune;
800 }
801
802 int handle_revision_arg(const char *arg, struct rev_info *revs,
803                         int flags,
804                         int cant_be_filename)
805 {
806         unsigned mode;
807         char *dotdot;
808         struct object *object;
809         unsigned char sha1[20];
810         int local_flags;
811
812         dotdot = strstr(arg, "..");
813         if (dotdot) {
814                 unsigned char from_sha1[20];
815                 const char *next = dotdot + 2;
816                 const char *this = arg;
817                 int symmetric = *next == '.';
818                 unsigned int flags_exclude = flags ^ UNINTERESTING;
819
820                 *dotdot = 0;
821                 next += symmetric;
822
823                 if (!*next)
824                         next = "HEAD";
825                 if (dotdot == arg)
826                         this = "HEAD";
827                 if (!get_sha1(this, from_sha1) &&
828                     !get_sha1(next, sha1)) {
829                         struct commit *a, *b;
830                         struct commit_list *exclude;
831
832                         a = lookup_commit_reference(from_sha1);
833                         b = lookup_commit_reference(sha1);
834                         if (!a || !b) {
835                                 die(symmetric ?
836                                     "Invalid symmetric difference expression %s...%s" :
837                                     "Invalid revision range %s..%s",
838                                     arg, next);
839                         }
840
841                         if (!cant_be_filename) {
842                                 *dotdot = '.';
843                                 verify_non_filename(revs->prefix, arg);
844                         }
845
846                         if (symmetric) {
847                                 exclude = get_merge_bases(a, b, 1);
848                                 add_pending_commit_list(revs, exclude,
849                                                         flags_exclude);
850                                 free_commit_list(exclude);
851                                 a->object.flags |= flags | SYMMETRIC_LEFT;
852                         } else
853                                 a->object.flags |= flags_exclude;
854                         b->object.flags |= flags;
855                         add_pending_object(revs, &a->object, this);
856                         add_pending_object(revs, &b->object, next);
857                         return 0;
858                 }
859                 *dotdot = '.';
860         }
861         dotdot = strstr(arg, "^@");
862         if (dotdot && !dotdot[2]) {
863                 *dotdot = 0;
864                 if (add_parents_only(revs, arg, flags))
865                         return 0;
866                 *dotdot = '^';
867         }
868         dotdot = strstr(arg, "^!");
869         if (dotdot && !dotdot[2]) {
870                 *dotdot = 0;
871                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
872                         *dotdot = '^';
873         }
874
875         local_flags = 0;
876         if (*arg == '^') {
877                 local_flags = UNINTERESTING;
878                 arg++;
879         }
880         if (get_sha1_with_mode(arg, sha1, &mode))
881                 return -1;
882         if (!cant_be_filename)
883                 verify_non_filename(revs->prefix, arg);
884         object = get_reference(revs, arg, sha1, flags ^ local_flags);
885         add_pending_object_with_mode(revs, object, arg, mode);
886         return 0;
887 }
888
889 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
890 {
891         if (!revs->grep_filter) {
892                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
893                 opt->status_only = 1;
894                 opt->pattern_tail = &(opt->pattern_list);
895                 opt->regflags = REG_NEWLINE;
896                 revs->grep_filter = opt;
897         }
898         append_grep_pattern(revs->grep_filter, ptn,
899                             "command line", 0, what);
900 }
901
902 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
903 {
904         char *pat;
905         const char *prefix;
906         int patlen, fldlen;
907
908         fldlen = strlen(field);
909         patlen = strlen(pattern);
910         pat = xmalloc(patlen + fldlen + 10);
911         prefix = ".*";
912         if (*pattern == '^') {
913                 prefix = "";
914                 pattern++;
915         }
916         sprintf(pat, "^%s %s%s", field, prefix, pattern);
917         add_grep(revs, pat, GREP_PATTERN_HEAD);
918 }
919
920 static void add_message_grep(struct rev_info *revs, const char *pattern)
921 {
922         add_grep(revs, pattern, GREP_PATTERN_BODY);
923 }
924
925 static void add_ignore_packed(struct rev_info *revs, const char *name)
926 {
927         int num = ++revs->num_ignore_packed;
928
929         revs->ignore_packed = xrealloc(revs->ignore_packed,
930                                        sizeof(const char **) * (num + 1));
931         revs->ignore_packed[num-1] = name;
932         revs->ignore_packed[num] = NULL;
933 }
934
935 /*
936  * Parse revision information, filling in the "rev_info" structure,
937  * and removing the used arguments from the argument list.
938  *
939  * Returns the number of arguments left that weren't recognized
940  * (which are also moved to the head of the argument list)
941  */
942 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
943 {
944         int i, flags, seen_dashdash, show_merge;
945         const char **unrecognized = argv + 1;
946         int left = 1;
947         int all_match = 0;
948         int regflags = 0;
949         int fixed = 0;
950
951         /* First, search for "--" */
952         seen_dashdash = 0;
953         for (i = 1; i < argc; i++) {
954                 const char *arg = argv[i];
955                 if (strcmp(arg, "--"))
956                         continue;
957                 argv[i] = NULL;
958                 argc = i;
959                 if (argv[i + 1])
960                         revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
961                 seen_dashdash = 1;
962                 break;
963         }
964
965         flags = show_merge = 0;
966         for (i = 1; i < argc; i++) {
967                 const char *arg = argv[i];
968                 if (*arg == '-') {
969                         int opts;
970                         if (!prefixcmp(arg, "--max-count=")) {
971                                 revs->max_count = atoi(arg + 12);
972                                 continue;
973                         }
974                         if (!prefixcmp(arg, "--skip=")) {
975                                 revs->skip_count = atoi(arg + 7);
976                                 continue;
977                         }
978                         /* accept -<digit>, like traditional "head" */
979                         if ((*arg == '-') && isdigit(arg[1])) {
980                                 revs->max_count = atoi(arg + 1);
981                                 continue;
982                         }
983                         if (!strcmp(arg, "-n")) {
984                                 if (argc <= i + 1)
985                                         die("-n requires an argument");
986                                 revs->max_count = atoi(argv[++i]);
987                                 continue;
988                         }
989                         if (!prefixcmp(arg, "-n")) {
990                                 revs->max_count = atoi(arg + 2);
991                                 continue;
992                         }
993                         if (!prefixcmp(arg, "--max-age=")) {
994                                 revs->max_age = atoi(arg + 10);
995                                 continue;
996                         }
997                         if (!prefixcmp(arg, "--since=")) {
998                                 revs->max_age = approxidate(arg + 8);
999                                 continue;
1000                         }
1001                         if (!prefixcmp(arg, "--after=")) {
1002                                 revs->max_age = approxidate(arg + 8);
1003                                 continue;
1004                         }
1005                         if (!prefixcmp(arg, "--min-age=")) {
1006                                 revs->min_age = atoi(arg + 10);
1007                                 continue;
1008                         }
1009                         if (!prefixcmp(arg, "--before=")) {
1010                                 revs->min_age = approxidate(arg + 9);
1011                                 continue;
1012                         }
1013                         if (!prefixcmp(arg, "--until=")) {
1014                                 revs->min_age = approxidate(arg + 8);
1015                                 continue;
1016                         }
1017                         if (!strcmp(arg, "--all")) {
1018                                 handle_all(revs, flags);
1019                                 continue;
1020                         }
1021                         if (!strcmp(arg, "--first-parent")) {
1022                                 revs->first_parent_only = 1;
1023                                 continue;
1024                         }
1025                         if (!strcmp(arg, "--reflog")) {
1026                                 handle_reflog(revs, flags);
1027                                 continue;
1028                         }
1029                         if (!strcmp(arg, "-g") ||
1030                                         !strcmp(arg, "--walk-reflogs")) {
1031                                 init_reflog_walk(&revs->reflog_info);
1032                                 continue;
1033                         }
1034                         if (!strcmp(arg, "--not")) {
1035                                 flags ^= UNINTERESTING;
1036                                 continue;
1037                         }
1038                         if (!strcmp(arg, "--default")) {
1039                                 if (++i >= argc)
1040                                         die("bad --default argument");
1041                                 def = argv[i];
1042                                 continue;
1043                         }
1044                         if (!strcmp(arg, "--merge")) {
1045                                 show_merge = 1;
1046                                 continue;
1047                         }
1048                         if (!strcmp(arg, "--topo-order")) {
1049                                 revs->topo_order = 1;
1050                                 continue;
1051                         }
1052                         if (!strcmp(arg, "--date-order")) {
1053                                 revs->lifo = 0;
1054                                 revs->topo_order = 1;
1055                                 continue;
1056                         }
1057                         if (!prefixcmp(arg, "--early-output")) {
1058                                 int count = 100;
1059                                 switch (arg[14]) {
1060                                 case '=':
1061                                         count = atoi(arg+15);
1062                                         /* Fallthrough */
1063                                 case 0:
1064                                         revs->topo_order = 1;
1065                                         revs->early_output = count;
1066                                         continue;
1067                                 }
1068                         }
1069                         if (!strcmp(arg, "--parents")) {
1070                                 revs->parents = 1;
1071                                 continue;
1072                         }
1073                         if (!strcmp(arg, "--dense")) {
1074                                 revs->dense = 1;
1075                                 continue;
1076                         }
1077                         if (!strcmp(arg, "--sparse")) {
1078                                 revs->dense = 0;
1079                                 continue;
1080                         }
1081                         if (!strcmp(arg, "--show-all")) {
1082                                 revs->show_all = 1;
1083                                 continue;
1084                         }
1085                         if (!strcmp(arg, "--remove-empty")) {
1086                                 revs->remove_empty_trees = 1;
1087                                 continue;
1088                         }
1089                         if (!strcmp(arg, "--no-merges")) {
1090                                 revs->no_merges = 1;
1091                                 continue;
1092                         }
1093                         if (!strcmp(arg, "--boundary")) {
1094                                 revs->boundary = 1;
1095                                 continue;
1096                         }
1097                         if (!strcmp(arg, "--left-right")) {
1098                                 revs->left_right = 1;
1099                                 continue;
1100                         }
1101                         if (!strcmp(arg, "--cherry-pick")) {
1102                                 revs->cherry_pick = 1;
1103                                 revs->limited = 1;
1104                                 continue;
1105                         }
1106                         if (!strcmp(arg, "--objects")) {
1107                                 revs->tag_objects = 1;
1108                                 revs->tree_objects = 1;
1109                                 revs->blob_objects = 1;
1110                                 continue;
1111                         }
1112                         if (!strcmp(arg, "--objects-edge")) {
1113                                 revs->tag_objects = 1;
1114                                 revs->tree_objects = 1;
1115                                 revs->blob_objects = 1;
1116                                 revs->edge_hint = 1;
1117                                 continue;
1118                         }
1119                         if (!strcmp(arg, "--unpacked")) {
1120                                 revs->unpacked = 1;
1121                                 free(revs->ignore_packed);
1122                                 revs->ignore_packed = NULL;
1123                                 revs->num_ignore_packed = 0;
1124                                 continue;
1125                         }
1126                         if (!prefixcmp(arg, "--unpacked=")) {
1127                                 revs->unpacked = 1;
1128                                 add_ignore_packed(revs, arg+11);
1129                                 continue;
1130                         }
1131                         if (!strcmp(arg, "-r")) {
1132                                 revs->diff = 1;
1133                                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1134                                 continue;
1135                         }
1136                         if (!strcmp(arg, "-t")) {
1137                                 revs->diff = 1;
1138                                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1139                                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1140                                 continue;
1141                         }
1142                         if (!strcmp(arg, "-m")) {
1143                                 revs->ignore_merges = 0;
1144                                 continue;
1145                         }
1146                         if (!strcmp(arg, "-c")) {
1147                                 revs->diff = 1;
1148                                 revs->dense_combined_merges = 0;
1149                                 revs->combine_merges = 1;
1150                                 continue;
1151                         }
1152                         if (!strcmp(arg, "--cc")) {
1153                                 revs->diff = 1;
1154                                 revs->dense_combined_merges = 1;
1155                                 revs->combine_merges = 1;
1156                                 continue;
1157                         }
1158                         if (!strcmp(arg, "-v")) {
1159                                 revs->verbose_header = 1;
1160                                 continue;
1161                         }
1162                         if (!prefixcmp(arg, "--pretty")) {
1163                                 revs->verbose_header = 1;
1164                                 revs->commit_format = get_commit_format(arg+8);
1165                                 continue;
1166                         }
1167                         if (!strcmp(arg, "--root")) {
1168                                 revs->show_root_diff = 1;
1169                                 continue;
1170                         }
1171                         if (!strcmp(arg, "--no-commit-id")) {
1172                                 revs->no_commit_id = 1;
1173                                 continue;
1174                         }
1175                         if (!strcmp(arg, "--always")) {
1176                                 revs->always_show_header = 1;
1177                                 continue;
1178                         }
1179                         if (!strcmp(arg, "--no-abbrev")) {
1180                                 revs->abbrev = 0;
1181                                 continue;
1182                         }
1183                         if (!strcmp(arg, "--abbrev")) {
1184                                 revs->abbrev = DEFAULT_ABBREV;
1185                                 continue;
1186                         }
1187                         if (!prefixcmp(arg, "--abbrev=")) {
1188                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1189                                 if (revs->abbrev < MINIMUM_ABBREV)
1190                                         revs->abbrev = MINIMUM_ABBREV;
1191                                 else if (revs->abbrev > 40)
1192                                         revs->abbrev = 40;
1193                                 continue;
1194                         }
1195                         if (!strcmp(arg, "--abbrev-commit")) {
1196                                 revs->abbrev_commit = 1;
1197                                 continue;
1198                         }
1199                         if (!strcmp(arg, "--full-diff")) {
1200                                 revs->diff = 1;
1201                                 revs->full_diff = 1;
1202                                 continue;
1203                         }
1204                         if (!strcmp(arg, "--full-history")) {
1205                                 revs->simplify_history = 0;
1206                                 continue;
1207                         }
1208                         if (!strcmp(arg, "--relative-date")) {
1209                                 revs->date_mode = DATE_RELATIVE;
1210                                 continue;
1211                         }
1212                         if (!strncmp(arg, "--date=", 7)) {
1213                                 revs->date_mode = parse_date_format(arg + 7);
1214                                 continue;
1215                         }
1216                         if (!strcmp(arg, "--log-size")) {
1217                                 revs->show_log_size = 1;
1218                                 continue;
1219                         }
1220
1221                         /*
1222                          * Grepping the commit log
1223                          */
1224                         if (!prefixcmp(arg, "--author=")) {
1225                                 add_header_grep(revs, "author", arg+9);
1226                                 continue;
1227                         }
1228                         if (!prefixcmp(arg, "--committer=")) {
1229                                 add_header_grep(revs, "committer", arg+12);
1230                                 continue;
1231                         }
1232                         if (!prefixcmp(arg, "--grep=")) {
1233                                 add_message_grep(revs, arg+7);
1234                                 continue;
1235                         }
1236                         if (!strcmp(arg, "--extended-regexp") ||
1237                             !strcmp(arg, "-E")) {
1238                                 regflags |= REG_EXTENDED;
1239                                 continue;
1240                         }
1241                         if (!strcmp(arg, "--regexp-ignore-case") ||
1242                             !strcmp(arg, "-i")) {
1243                                 regflags |= REG_ICASE;
1244                                 continue;
1245                         }
1246                         if (!strcmp(arg, "--fixed-strings") ||
1247                             !strcmp(arg, "-F")) {
1248                                 fixed = 1;
1249                                 continue;
1250                         }
1251                         if (!strcmp(arg, "--all-match")) {
1252                                 all_match = 1;
1253                                 continue;
1254                         }
1255                         if (!prefixcmp(arg, "--encoding=")) {
1256                                 arg += 11;
1257                                 if (strcmp(arg, "none"))
1258                                         git_log_output_encoding = xstrdup(arg);
1259                                 else
1260                                         git_log_output_encoding = "";
1261                                 continue;
1262                         }
1263                         if (!strcmp(arg, "--reverse")) {
1264                                 revs->reverse ^= 1;
1265                                 continue;
1266                         }
1267                         if (!strcmp(arg, "--no-walk")) {
1268                                 revs->no_walk = 1;
1269                                 continue;
1270                         }
1271                         if (!strcmp(arg, "--do-walk")) {
1272                                 revs->no_walk = 0;
1273                                 continue;
1274                         }
1275
1276                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1277                         if (opts > 0) {
1278                                 i += opts - 1;
1279                                 continue;
1280                         }
1281                         *unrecognized++ = arg;
1282                         left++;
1283                         continue;
1284                 }
1285
1286                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1287                         int j;
1288                         if (seen_dashdash || *arg == '^')
1289                                 die("bad revision '%s'", arg);
1290
1291                         /* If we didn't have a "--":
1292                          * (1) all filenames must exist;
1293                          * (2) all rev-args must not be interpretable
1294                          *     as a valid filename.
1295                          * but the latter we have checked in the main loop.
1296                          */
1297                         for (j = i; j < argc; j++)
1298                                 verify_filename(revs->prefix, argv[j]);
1299
1300                         revs->prune_data = get_pathspec(revs->prefix,
1301                                                         argv + i);
1302                         break;
1303                 }
1304         }
1305
1306         if (revs->grep_filter) {
1307                 revs->grep_filter->regflags |= regflags;
1308                 revs->grep_filter->fixed = fixed;
1309         }
1310
1311         if (show_merge)
1312                 prepare_show_merge(revs);
1313         if (def && !revs->pending.nr) {
1314                 unsigned char sha1[20];
1315                 struct object *object;
1316                 unsigned mode;
1317                 if (get_sha1_with_mode(def, sha1, &mode))
1318                         die("bad default revision '%s'", def);
1319                 object = get_reference(revs, def, sha1, 0);
1320                 add_pending_object_with_mode(revs, object, def, mode);
1321         }
1322
1323         /* Did the user ask for any diff output? Run the diff! */
1324         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1325                 revs->diff = 1;
1326
1327         /* Pickaxe, diff-filter and rename following need diffs */
1328         if (revs->diffopt.pickaxe ||
1329             revs->diffopt.filter ||
1330             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1331                 revs->diff = 1;
1332
1333         if (revs->topo_order)
1334                 revs->limited = 1;
1335
1336         if (revs->prune_data) {
1337                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1338                 /* Can't prune commits with rename following: the paths change.. */
1339                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1340                         revs->prune = 1;
1341                 if (!revs->full_diff)
1342                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1343         }
1344         if (revs->combine_merges) {
1345                 revs->ignore_merges = 0;
1346                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1347                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1348         }
1349         revs->diffopt.abbrev = revs->abbrev;
1350         if (diff_setup_done(&revs->diffopt) < 0)
1351                 die("diff_setup_done failed");
1352
1353         if (revs->grep_filter) {
1354                 revs->grep_filter->all_match = all_match;
1355                 compile_grep_patterns(revs->grep_filter);
1356         }
1357
1358         if (revs->reverse && revs->reflog_info)
1359                 die("cannot combine --reverse with --walk-reflogs");
1360
1361         return left;
1362 }
1363
1364 int prepare_revision_walk(struct rev_info *revs)
1365 {
1366         int nr = revs->pending.nr;
1367         struct object_array_entry *e, *list;
1368
1369         e = list = revs->pending.objects;
1370         revs->pending.nr = 0;
1371         revs->pending.alloc = 0;
1372         revs->pending.objects = NULL;
1373         while (--nr >= 0) {
1374                 struct commit *commit = handle_commit(revs, e->item, e->name);
1375                 if (commit) {
1376                         if (!(commit->object.flags & SEEN)) {
1377                                 commit->object.flags |= SEEN;
1378                                 insert_by_date(commit, &revs->commits);
1379                         }
1380                 }
1381                 e++;
1382         }
1383         free(list);
1384
1385         if (revs->no_walk)
1386                 return 0;
1387         if (revs->limited)
1388                 if (limit_list(revs) < 0)
1389                         return -1;
1390         if (revs->topo_order)
1391                 sort_in_topological_order(&revs->commits, revs->lifo);
1392         return 0;
1393 }
1394
1395 enum rewrite_result {
1396         rewrite_one_ok,
1397         rewrite_one_noparents,
1398         rewrite_one_error,
1399 };
1400
1401 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1402 {
1403         for (;;) {
1404                 struct commit *p = *pp;
1405                 if (!revs->limited)
1406                         if (add_parents_to_list(revs, p, &revs->commits) < 0)
1407                                 return rewrite_one_error;
1408                 if (p->parents && p->parents->next)
1409                         return rewrite_one_ok;
1410                 if (p->object.flags & UNINTERESTING)
1411                         return rewrite_one_ok;
1412                 if (!(p->object.flags & TREESAME))
1413                         return rewrite_one_ok;
1414                 if (!p->parents)
1415                         return rewrite_one_noparents;
1416                 *pp = p->parents->item;
1417         }
1418 }
1419
1420 static void remove_duplicate_parents(struct commit *commit)
1421 {
1422         struct commit_list **pp, *p;
1423
1424         /* Examine existing parents while marking ones we have seen... */
1425         pp = &commit->parents;
1426         while ((p = *pp) != NULL) {
1427                 struct commit *parent = p->item;
1428                 if (parent->object.flags & TMP_MARK) {
1429                         *pp = p->next;
1430                         continue;
1431                 }
1432                 parent->object.flags |= TMP_MARK;
1433                 pp = &p->next;
1434         }
1435         /* ... and clear the temporary mark */
1436         for (p = commit->parents; p; p = p->next)
1437                 p->item->object.flags &= ~TMP_MARK;
1438 }
1439
1440 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1441 {
1442         struct commit_list **pp = &commit->parents;
1443         while (*pp) {
1444                 struct commit_list *parent = *pp;
1445                 switch (rewrite_one(revs, &parent->item)) {
1446                 case rewrite_one_ok:
1447                         break;
1448                 case rewrite_one_noparents:
1449                         *pp = parent->next;
1450                         continue;
1451                 case rewrite_one_error:
1452                         return -1;
1453                 }
1454                 pp = &parent->next;
1455         }
1456         remove_duplicate_parents(commit);
1457         return 0;
1458 }
1459
1460 static int commit_match(struct commit *commit, struct rev_info *opt)
1461 {
1462         if (!opt->grep_filter)
1463                 return 1;
1464         return grep_buffer(opt->grep_filter,
1465                            NULL, /* we say nothing, not even filename */
1466                            commit->buffer, strlen(commit->buffer));
1467 }
1468
1469 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1470 {
1471         if (commit->object.flags & SHOWN)
1472                 return commit_ignore;
1473         if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1474                 return commit_ignore;
1475         if (revs->show_all)
1476                 return commit_show;
1477         if (commit->object.flags & UNINTERESTING)
1478                 return commit_ignore;
1479         if (revs->min_age != -1 && (commit->date > revs->min_age))
1480                 return commit_ignore;
1481         if (revs->no_merges && commit->parents && commit->parents->next)
1482                 return commit_ignore;
1483         if (!commit_match(commit, revs))
1484                 return commit_ignore;
1485         if (revs->prune && revs->dense) {
1486                 /* Commit without changes? */
1487                 if (commit->object.flags & TREESAME) {
1488                         /* drop merges unless we want parenthood */
1489                         if (!revs->parents)
1490                                 return commit_ignore;
1491                         /* non-merge - always ignore it */
1492                         if (!commit->parents || !commit->parents->next)
1493                                 return commit_ignore;
1494                 }
1495                 if (revs->parents && rewrite_parents(revs, commit) < 0)
1496                         return commit_error;
1497         }
1498         return commit_show;
1499 }
1500
1501 static struct commit *get_revision_1(struct rev_info *revs)
1502 {
1503         if (!revs->commits)
1504                 return NULL;
1505
1506         do {
1507                 struct commit_list *entry = revs->commits;
1508                 struct commit *commit = entry->item;
1509
1510                 revs->commits = entry->next;
1511                 free(entry);
1512
1513                 if (revs->reflog_info)
1514                         fake_reflog_parent(revs->reflog_info, commit);
1515
1516                 /*
1517                  * If we haven't done the list limiting, we need to look at
1518                  * the parents here. We also need to do the date-based limiting
1519                  * that we'd otherwise have done in limit_list().
1520                  */
1521                 if (!revs->limited) {
1522                         if (revs->max_age != -1 &&
1523                             (commit->date < revs->max_age))
1524                                 continue;
1525                         if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1526                                 return NULL;
1527                 }
1528
1529                 switch (simplify_commit(revs, commit)) {
1530                 case commit_ignore:
1531                         continue;
1532                 case commit_error:
1533                         return NULL;
1534                 default:
1535                         return commit;
1536                 }
1537         } while (revs->commits);
1538         return NULL;
1539 }
1540
1541 static void gc_boundary(struct object_array *array)
1542 {
1543         unsigned nr = array->nr;
1544         unsigned alloc = array->alloc;
1545         struct object_array_entry *objects = array->objects;
1546
1547         if (alloc <= nr) {
1548                 unsigned i, j;
1549                 for (i = j = 0; i < nr; i++) {
1550                         if (objects[i].item->flags & SHOWN)
1551                                 continue;
1552                         if (i != j)
1553                                 objects[j] = objects[i];
1554                         j++;
1555                 }
1556                 for (i = j; i < nr; i++)
1557                         objects[i].item = NULL;
1558                 array->nr = j;
1559         }
1560 }
1561
1562 struct commit *get_revision(struct rev_info *revs)
1563 {
1564         struct commit *c = NULL;
1565         struct commit_list *l;
1566
1567         if (revs->boundary == 2) {
1568                 unsigned i;
1569                 struct object_array *array = &revs->boundary_commits;
1570                 struct object_array_entry *objects = array->objects;
1571                 for (i = 0; i < array->nr; i++) {
1572                         c = (struct commit *)(objects[i].item);
1573                         if (!c)
1574                                 continue;
1575                         if (!(c->object.flags & CHILD_SHOWN))
1576                                 continue;
1577                         if (!(c->object.flags & SHOWN))
1578                                 break;
1579                 }
1580                 if (array->nr <= i)
1581                         return NULL;
1582
1583                 c->object.flags |= SHOWN | BOUNDARY;
1584                 return c;
1585         }
1586
1587         if (revs->reverse) {
1588                 int limit = -1;
1589
1590                 if (0 <= revs->max_count) {
1591                         limit = revs->max_count;
1592                         if (0 < revs->skip_count)
1593                                 limit += revs->skip_count;
1594                 }
1595                 l = NULL;
1596                 while ((c = get_revision_1(revs))) {
1597                         commit_list_insert(c, &l);
1598                         if ((0 < limit) && !--limit)
1599                                 break;
1600                 }
1601                 revs->commits = l;
1602                 revs->reverse = 0;
1603                 revs->max_count = -1;
1604                 c = NULL;
1605         }
1606
1607         /*
1608          * Now pick up what they want to give us
1609          */
1610         c = get_revision_1(revs);
1611         if (c) {
1612                 while (0 < revs->skip_count) {
1613                         revs->skip_count--;
1614                         c = get_revision_1(revs);
1615                         if (!c)
1616                                 break;
1617                 }
1618         }
1619
1620         /*
1621          * Check the max_count.
1622          */
1623         switch (revs->max_count) {
1624         case -1:
1625                 break;
1626         case 0:
1627                 c = NULL;
1628                 break;
1629         default:
1630                 revs->max_count--;
1631         }
1632
1633         if (c)
1634                 c->object.flags |= SHOWN;
1635
1636         if (!revs->boundary) {
1637                 return c;
1638         }
1639
1640         if (!c) {
1641                 /*
1642                  * get_revision_1() runs out the commits, and
1643                  * we are done computing the boundaries.
1644                  * switch to boundary commits output mode.
1645                  */
1646                 revs->boundary = 2;
1647                 return get_revision(revs);
1648         }
1649
1650         /*
1651          * boundary commits are the commits that are parents of the
1652          * ones we got from get_revision_1() but they themselves are
1653          * not returned from get_revision_1().  Before returning
1654          * 'c', we need to mark its parents that they could be boundaries.
1655          */
1656
1657         for (l = c->parents; l; l = l->next) {
1658                 struct object *p;
1659                 p = &(l->item->object);
1660                 if (p->flags & (CHILD_SHOWN | SHOWN))
1661                         continue;
1662                 p->flags |= CHILD_SHOWN;
1663                 gc_boundary(&revs->boundary_commits);
1664                 add_object_array(p, NULL, &revs->boundary_commits);
1665         }
1666
1667         return c;
1668 }