Code

t7300: add test for clean with wildcard pathspec
[git.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"
13 volatile show_early_output_fn_t show_early_output;
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;
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 }
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 }
47 static void mark_blob_uninteresting(struct blob *blob)
48 {
49         if (blob->object.flags & UNINTERESTING)
50                 return;
51         blob->object.flags |= UNINTERESTING;
52 }
54 void mark_tree_uninteresting(struct tree *tree)
55 {
56         struct tree_desc desc;
57         struct name_entry entry;
58         struct object *obj = &tree->object;
60         if (obj->flags & UNINTERESTING)
61                 return;
62         obj->flags |= UNINTERESTING;
63         if (!has_sha1_file(obj->sha1))
64                 return;
65         if (parse_tree(tree) < 0)
66                 die("bad tree %s", sha1_to_hex(obj->sha1));
68         init_tree_desc(&desc, tree->buffer, tree->size);
69         while (tree_entry(&desc, &entry)) {
70                 switch (object_type(entry.mode)) {
71                 case OBJ_TREE:
72                         mark_tree_uninteresting(lookup_tree(entry.sha1));
73                         break;
74                 case OBJ_BLOB:
75                         mark_blob_uninteresting(lookup_blob(entry.sha1));
76                         break;
77                 default:
78                         /* Subproject commit - not in this repository */
79                         break;
80                 }
81         }
83         /*
84          * We don't care about the tree any more
85          * after it has been marked uninteresting.
86          */
87         free(tree->buffer);
88         tree->buffer = NULL;
89 }
91 void mark_parents_uninteresting(struct commit *commit)
92 {
93         struct commit_list *parents = commit->parents;
95         while (parents) {
96                 struct commit *commit = parents->item;
97                 if (!(commit->object.flags & UNINTERESTING)) {
98                         commit->object.flags |= UNINTERESTING;
100                         /*
101                          * Normally we haven't parsed the parent
102                          * yet, so we won't have a parent of a parent
103                          * here. However, it may turn out that we've
104                          * reached this commit some other way (where it
105                          * wasn't uninteresting), in which case we need
106                          * to mark its parents recursively too..
107                          */
108                         if (commit->parents)
109                                 mark_parents_uninteresting(commit);
110                 }
112                 /*
113                  * A missing commit is ok iff its parent is marked
114                  * uninteresting.
115                  *
116                  * We just mark such a thing parsed, so that when
117                  * it is popped next time around, we won't be trying
118                  * to parse it and get an error.
119                  */
120                 if (!has_sha1_file(commit->object.sha1))
121                         commit->object.parsed = 1;
122                 parents = parents->next;
123         }
126 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
128         if (revs->no_walk && (obj->flags & UNINTERESTING))
129                 die("object ranges do not make sense when not walking revisions");
130         if (revs->reflog_info && obj->type == OBJ_COMMIT &&
131                         add_reflog_for_walk(revs->reflog_info,
132                                 (struct commit *)obj, name))
133                 return;
134         add_object_array_with_mode(obj, name, &revs->pending, mode);
137 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
139         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
142 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
144         struct object *object;
146         object = parse_object(sha1);
147         if (!object)
148                 die("bad object %s", name);
149         object->flags |= flags;
150         return object;
153 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
155         unsigned long flags = object->flags;
157         /*
158          * Tag object? Look what it points to..
159          */
160         while (object->type == OBJ_TAG) {
161                 struct tag *tag = (struct tag *) object;
162                 if (revs->tag_objects && !(flags & UNINTERESTING))
163                         add_pending_object(revs, object, tag->tag);
164                 object = parse_object(tag->tagged->sha1);
165                 if (!object)
166                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
167         }
169         /*
170          * Commit object? Just return it, we'll do all the complex
171          * reachability crud.
172          */
173         if (object->type == OBJ_COMMIT) {
174                 struct commit *commit = (struct commit *)object;
175                 if (parse_commit(commit) < 0)
176                         die("unable to parse commit %s", name);
177                 if (flags & UNINTERESTING) {
178                         commit->object.flags |= UNINTERESTING;
179                         mark_parents_uninteresting(commit);
180                         revs->limited = 1;
181                 }
182                 return commit;
183         }
185         /*
186          * Tree object? Either mark it uniniteresting, or add it
187          * to the list of objects to look at later..
188          */
189         if (object->type == OBJ_TREE) {
190                 struct tree *tree = (struct tree *)object;
191                 if (!revs->tree_objects)
192                         return NULL;
193                 if (flags & UNINTERESTING) {
194                         mark_tree_uninteresting(tree);
195                         return NULL;
196                 }
197                 add_pending_object(revs, object, "");
198                 return NULL;
199         }
201         /*
202          * Blob object? You know the drill by now..
203          */
204         if (object->type == OBJ_BLOB) {
205                 struct blob *blob = (struct blob *)object;
206                 if (!revs->blob_objects)
207                         return NULL;
208                 if (flags & UNINTERESTING) {
209                         mark_blob_uninteresting(blob);
210                         return NULL;
211                 }
212                 add_pending_object(revs, object, "");
213                 return NULL;
214         }
215         die("%s is unknown object", name);
218 static int everybody_uninteresting(struct commit_list *orig)
220         struct commit_list *list = orig;
221         while (list) {
222                 struct commit *commit = list->item;
223                 list = list->next;
224                 if (commit->object.flags & UNINTERESTING)
225                         continue;
226                 return 0;
227         }
228         return 1;
231 /*
232  * The goal is to get REV_TREE_NEW as the result only if the
233  * diff consists of all '+' (and no other changes), and
234  * REV_TREE_DIFFERENT otherwise (of course if the trees are
235  * the same we want REV_TREE_SAME).  That means that once we
236  * get to REV_TREE_DIFFERENT, we do not have to look any further.
237  */
238 static int tree_difference = REV_TREE_SAME;
240 static void file_add_remove(struct diff_options *options,
241                     int addremove, unsigned mode,
242                     const unsigned char *sha1,
243                     const char *base, const char *path)
245         int diff = REV_TREE_DIFFERENT;
247         /*
248          * Is it an add of a new file? It means that the old tree
249          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
250          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
251          * (and if it already was "REV_TREE_NEW", we'll keep it
252          * "REV_TREE_NEW" of course).
253          */
254         if (addremove == '+') {
255                 diff = tree_difference;
256                 if (diff != REV_TREE_SAME)
257                         return;
258                 diff = REV_TREE_NEW;
259         }
260         tree_difference = diff;
261         if (tree_difference == REV_TREE_DIFFERENT)
262                 DIFF_OPT_SET(options, HAS_CHANGES);
265 static void file_change(struct diff_options *options,
266                  unsigned old_mode, unsigned new_mode,
267                  const unsigned char *old_sha1,
268                  const unsigned char *new_sha1,
269                  const char *base, const char *path)
271         tree_difference = REV_TREE_DIFFERENT;
272         DIFF_OPT_SET(options, HAS_CHANGES);
275 static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
277         if (!t1)
278                 return REV_TREE_NEW;
279         if (!t2)
280                 return REV_TREE_DIFFERENT;
281         tree_difference = REV_TREE_SAME;
282         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
283         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
284                            &revs->pruning) < 0)
285                 return REV_TREE_DIFFERENT;
286         return tree_difference;
289 static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
291         int retval;
292         void *tree;
293         unsigned long size;
294         struct tree_desc empty, real;
296         if (!t1)
297                 return 0;
299         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
300         if (!tree)
301                 return 0;
302         init_tree_desc(&real, tree, size);
303         init_tree_desc(&empty, "", 0);
305         tree_difference = REV_TREE_SAME;
306         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
307         retval = diff_tree(&empty, &real, "", &revs->pruning);
308         free(tree);
310         return retval >= 0 && (tree_difference == REV_TREE_SAME);
313 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
315         struct commit_list **pp, *parent;
316         int tree_changed = 0, tree_same = 0;
318         /*
319          * If we don't do pruning, everything is interesting
320          */
321         if (!revs->prune)
322                 return;
324         if (!commit->tree)
325                 return;
327         if (!commit->parents) {
328                 if (rev_same_tree_as_empty(revs, commit->tree))
329                         commit->object.flags |= TREESAME;
330                 return;
331         }
333         /*
334          * Normal non-merge commit? If we don't want to make the
335          * history dense, we consider it always to be a change..
336          */
337         if (!revs->dense && !commit->parents->next)
338                 return;
340         pp = &commit->parents;
341         while ((parent = *pp) != NULL) {
342                 struct commit *p = parent->item;
344                 if (parse_commit(p) < 0)
345                         die("cannot simplify commit %s (because of %s)",
346                             sha1_to_hex(commit->object.sha1),
347                             sha1_to_hex(p->object.sha1));
348                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
349                 case REV_TREE_SAME:
350                         tree_same = 1;
351                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
352                                 /* Even if a merge with an uninteresting
353                                  * side branch brought the entire change
354                                  * we are interested in, we do not want
355                                  * to lose the other branches of this
356                                  * merge, so we just keep going.
357                                  */
358                                 pp = &parent->next;
359                                 continue;
360                         }
361                         parent->next = NULL;
362                         commit->parents = parent;
363                         commit->object.flags |= TREESAME;
364                         return;
366                 case REV_TREE_NEW:
367                         if (revs->remove_empty_trees &&
368                             rev_same_tree_as_empty(revs, p->tree)) {
369                                 /* We are adding all the specified
370                                  * paths from this parent, so the
371                                  * history beyond this parent is not
372                                  * interesting.  Remove its parents
373                                  * (they are grandparents for us).
374                                  * IOW, we pretend this parent is a
375                                  * "root" commit.
376                                  */
377                                 if (parse_commit(p) < 0)
378                                         die("cannot simplify commit %s (invalid %s)",
379                                             sha1_to_hex(commit->object.sha1),
380                                             sha1_to_hex(p->object.sha1));
381                                 p->parents = NULL;
382                         }
383                 /* fallthrough */
384                 case REV_TREE_DIFFERENT:
385                         tree_changed = 1;
386                         pp = &parent->next;
387                         continue;
388                 }
389                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
390         }
391         if (tree_changed && !tree_same)
392                 return;
393         commit->object.flags |= TREESAME;
396 static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
398         struct commit_list *parent = commit->parents;
399         unsigned left_flag;
400         int add, rest;
402         if (commit->object.flags & ADDED)
403                 return 0;
404         commit->object.flags |= ADDED;
406         /*
407          * If the commit is uninteresting, don't try to
408          * prune parents - we want the maximal uninteresting
409          * set.
410          *
411          * Normally we haven't parsed the parent
412          * yet, so we won't have a parent of a parent
413          * here. However, it may turn out that we've
414          * reached this commit some other way (where it
415          * wasn't uninteresting), in which case we need
416          * to mark its parents recursively too..
417          */
418         if (commit->object.flags & UNINTERESTING) {
419                 while (parent) {
420                         struct commit *p = parent->item;
421                         parent = parent->next;
422                         if (parse_commit(p) < 0)
423                                 return -1;
424                         p->object.flags |= UNINTERESTING;
425                         if (p->parents)
426                                 mark_parents_uninteresting(p);
427                         if (p->object.flags & SEEN)
428                                 continue;
429                         p->object.flags |= SEEN;
430                         insert_by_date(p, list);
431                 }
432                 return 0;
433         }
435         /*
436          * Ok, the commit wasn't uninteresting. Try to
437          * simplify the commit history and find the parent
438          * that has no differences in the path set if one exists.
439          */
440         try_to_simplify_commit(revs, commit);
442         if (revs->no_walk)
443                 return 0;
445         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
447         rest = !revs->first_parent_only;
448         for (parent = commit->parents, add = 1; parent; add = rest) {
449                 struct commit *p = parent->item;
451                 parent = parent->next;
452                 if (parse_commit(p) < 0)
453                         return -1;
454                 p->object.flags |= left_flag;
455                 if (p->object.flags & SEEN)
456                         continue;
457                 p->object.flags |= SEEN;
458                 if (add)
459                         insert_by_date(p, list);
460         }
461         return 0;
464 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
466         struct commit_list *p;
467         int left_count = 0, right_count = 0;
468         int left_first;
469         struct patch_ids ids;
471         /* First count the commits on the left and on the right */
472         for (p = list; p; p = p->next) {
473                 struct commit *commit = p->item;
474                 unsigned flags = commit->object.flags;
475                 if (flags & BOUNDARY)
476                         ;
477                 else if (flags & SYMMETRIC_LEFT)
478                         left_count++;
479                 else
480                         right_count++;
481         }
483         left_first = left_count < right_count;
484         init_patch_ids(&ids);
485         if (revs->diffopt.nr_paths) {
486                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
487                 ids.diffopts.paths = revs->diffopt.paths;
488                 ids.diffopts.pathlens = revs->diffopt.pathlens;
489         }
491         /* Compute patch-ids for one side */
492         for (p = list; p; p = p->next) {
493                 struct commit *commit = p->item;
494                 unsigned flags = commit->object.flags;
496                 if (flags & BOUNDARY)
497                         continue;
498                 /*
499                  * If we have fewer left, left_first is set and we omit
500                  * commits on the right branch in this loop.  If we have
501                  * fewer right, we skip the left ones.
502                  */
503                 if (left_first != !!(flags & SYMMETRIC_LEFT))
504                         continue;
505                 commit->util = add_commit_patch_id(commit, &ids);
506         }
508         /* Check the other side */
509         for (p = list; p; p = p->next) {
510                 struct commit *commit = p->item;
511                 struct patch_id *id;
512                 unsigned flags = commit->object.flags;
514                 if (flags & BOUNDARY)
515                         continue;
516                 /*
517                  * If we have fewer left, left_first is set and we omit
518                  * commits on the left branch in this loop.
519                  */
520                 if (left_first == !!(flags & SYMMETRIC_LEFT))
521                         continue;
523                 /*
524                  * Have we seen the same patch id?
525                  */
526                 id = has_commit_patch_id(commit, &ids);
527                 if (!id)
528                         continue;
529                 id->seen = 1;
530                 commit->object.flags |= SHOWN;
531         }
533         /* Now check the original side for seen ones */
534         for (p = list; p; p = p->next) {
535                 struct commit *commit = p->item;
536                 struct patch_id *ent;
538                 ent = commit->util;
539                 if (!ent)
540                         continue;
541                 if (ent->seen)
542                         commit->object.flags |= SHOWN;
543                 commit->util = NULL;
544         }
546         free_patch_ids(&ids);
549 static int limit_list(struct rev_info *revs)
551         struct commit_list *list = revs->commits;
552         struct commit_list *newlist = NULL;
553         struct commit_list **p = &newlist;
555         while (list) {
556                 struct commit_list *entry = list;
557                 struct commit *commit = list->item;
558                 struct object *obj = &commit->object;
559                 show_early_output_fn_t show;
561                 list = list->next;
562                 free(entry);
564                 if (revs->max_age != -1 && (commit->date < revs->max_age))
565                         obj->flags |= UNINTERESTING;
566                 if (add_parents_to_list(revs, commit, &list) < 0)
567                         return -1;
568                 if (obj->flags & UNINTERESTING) {
569                         mark_parents_uninteresting(commit);
570                         if (everybody_uninteresting(list))
571                                 break;
572                         continue;
573                 }
574                 if (revs->min_age != -1 && (commit->date > revs->min_age))
575                         continue;
576                 p = &commit_list_insert(commit, p)->next;
578                 show = show_early_output;
579                 if (!show)
580                         continue;
582                 show(revs, newlist);
583                 show_early_output = NULL;
584         }
585         if (revs->cherry_pick)
586                 cherry_pick_list(newlist, revs);
588         revs->commits = newlist;
589         return 0;
592 struct all_refs_cb {
593         int all_flags;
594         int warned_bad_reflog;
595         struct rev_info *all_revs;
596         const char *name_for_errormsg;
597 };
599 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
601         struct all_refs_cb *cb = cb_data;
602         struct object *object = get_reference(cb->all_revs, path, sha1,
603                                               cb->all_flags);
604         add_pending_object(cb->all_revs, object, path);
605         return 0;
608 static void handle_all(struct rev_info *revs, unsigned flags)
610         struct all_refs_cb cb;
611         cb.all_revs = revs;
612         cb.all_flags = flags;
613         for_each_ref(handle_one_ref, &cb);
616 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
618         struct all_refs_cb *cb = cb_data;
619         if (!is_null_sha1(sha1)) {
620                 struct object *o = parse_object(sha1);
621                 if (o) {
622                         o->flags |= cb->all_flags;
623                         add_pending_object(cb->all_revs, o, "");
624                 }
625                 else if (!cb->warned_bad_reflog) {
626                         warning("reflog of '%s' references pruned commits",
627                                 cb->name_for_errormsg);
628                         cb->warned_bad_reflog = 1;
629                 }
630         }
633 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
634                 const char *email, unsigned long timestamp, int tz,
635                 const char *message, void *cb_data)
637         handle_one_reflog_commit(osha1, cb_data);
638         handle_one_reflog_commit(nsha1, cb_data);
639         return 0;
642 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
644         struct all_refs_cb *cb = cb_data;
645         cb->warned_bad_reflog = 0;
646         cb->name_for_errormsg = path;
647         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
648         return 0;
651 static void handle_reflog(struct rev_info *revs, unsigned flags)
653         struct all_refs_cb cb;
654         cb.all_revs = revs;
655         cb.all_flags = flags;
656         for_each_reflog(handle_one_reflog, &cb);
659 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
661         unsigned char sha1[20];
662         struct object *it;
663         struct commit *commit;
664         struct commit_list *parents;
666         if (*arg == '^') {
667                 flags ^= UNINTERESTING;
668                 arg++;
669         }
670         if (get_sha1(arg, sha1))
671                 return 0;
672         while (1) {
673                 it = get_reference(revs, arg, sha1, 0);
674                 if (it->type != OBJ_TAG)
675                         break;
676                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
677         }
678         if (it->type != OBJ_COMMIT)
679                 return 0;
680         commit = (struct commit *)it;
681         for (parents = commit->parents; parents; parents = parents->next) {
682                 it = &parents->item->object;
683                 it->flags |= flags;
684                 add_pending_object(revs, it, arg);
685         }
686         return 1;
689 void init_revisions(struct rev_info *revs, const char *prefix)
691         memset(revs, 0, sizeof(*revs));
693         revs->abbrev = DEFAULT_ABBREV;
694         revs->ignore_merges = 1;
695         revs->simplify_history = 1;
696         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
697         DIFF_OPT_SET(&revs->pruning, QUIET);
698         revs->pruning.add_remove = file_add_remove;
699         revs->pruning.change = file_change;
700         revs->lifo = 1;
701         revs->dense = 1;
702         revs->prefix = prefix;
703         revs->max_age = -1;
704         revs->min_age = -1;
705         revs->skip_count = -1;
706         revs->max_count = -1;
708         revs->commit_format = CMIT_FMT_DEFAULT;
710         diff_setup(&revs->diffopt);
713 static void add_pending_commit_list(struct rev_info *revs,
714                                     struct commit_list *commit_list,
715                                     unsigned int flags)
717         while (commit_list) {
718                 struct object *object = &commit_list->item->object;
719                 object->flags |= flags;
720                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
721                 commit_list = commit_list->next;
722         }
725 static void prepare_show_merge(struct rev_info *revs)
727         struct commit_list *bases;
728         struct commit *head, *other;
729         unsigned char sha1[20];
730         const char **prune = NULL;
731         int i, prune_num = 1; /* counting terminating NULL */
733         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
734                 die("--merge without HEAD?");
735         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
736                 die("--merge without MERGE_HEAD?");
737         add_pending_object(revs, &head->object, "HEAD");
738         add_pending_object(revs, &other->object, "MERGE_HEAD");
739         bases = get_merge_bases(head, other, 1);
740         while (bases) {
741                 struct commit *it = bases->item;
742                 struct commit_list *n = bases->next;
743                 free(bases);
744                 bases = n;
745                 it->object.flags |= UNINTERESTING;
746                 add_pending_object(revs, &it->object, "(merge-base)");
747         }
749         if (!active_nr)
750                 read_cache();
751         for (i = 0; i < active_nr; i++) {
752                 struct cache_entry *ce = active_cache[i];
753                 if (!ce_stage(ce))
754                         continue;
755                 if (ce_path_match(ce, revs->prune_data)) {
756                         prune_num++;
757                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
758                         prune[prune_num-2] = ce->name;
759                         prune[prune_num-1] = NULL;
760                 }
761                 while ((i+1 < active_nr) &&
762                        ce_same_name(ce, active_cache[i+1]))
763                         i++;
764         }
765         revs->prune_data = prune;
768 int handle_revision_arg(const char *arg, struct rev_info *revs,
769                         int flags,
770                         int cant_be_filename)
772         unsigned mode;
773         char *dotdot;
774         struct object *object;
775         unsigned char sha1[20];
776         int local_flags;
778         dotdot = strstr(arg, "..");
779         if (dotdot) {
780                 unsigned char from_sha1[20];
781                 const char *next = dotdot + 2;
782                 const char *this = arg;
783                 int symmetric = *next == '.';
784                 unsigned int flags_exclude = flags ^ UNINTERESTING;
786                 *dotdot = 0;
787                 next += symmetric;
789                 if (!*next)
790                         next = "HEAD";
791                 if (dotdot == arg)
792                         this = "HEAD";
793                 if (!get_sha1(this, from_sha1) &&
794                     !get_sha1(next, sha1)) {
795                         struct commit *a, *b;
796                         struct commit_list *exclude;
798                         a = lookup_commit_reference(from_sha1);
799                         b = lookup_commit_reference(sha1);
800                         if (!a || !b) {
801                                 die(symmetric ?
802                                     "Invalid symmetric difference expression %s...%s" :
803                                     "Invalid revision range %s..%s",
804                                     arg, next);
805                         }
807                         if (!cant_be_filename) {
808                                 *dotdot = '.';
809                                 verify_non_filename(revs->prefix, arg);
810                         }
812                         if (symmetric) {
813                                 exclude = get_merge_bases(a, b, 1);
814                                 add_pending_commit_list(revs, exclude,
815                                                         flags_exclude);
816                                 free_commit_list(exclude);
817                                 a->object.flags |= flags | SYMMETRIC_LEFT;
818                         } else
819                                 a->object.flags |= flags_exclude;
820                         b->object.flags |= flags;
821                         add_pending_object(revs, &a->object, this);
822                         add_pending_object(revs, &b->object, next);
823                         return 0;
824                 }
825                 *dotdot = '.';
826         }
827         dotdot = strstr(arg, "^@");
828         if (dotdot && !dotdot[2]) {
829                 *dotdot = 0;
830                 if (add_parents_only(revs, arg, flags))
831                         return 0;
832                 *dotdot = '^';
833         }
834         dotdot = strstr(arg, "^!");
835         if (dotdot && !dotdot[2]) {
836                 *dotdot = 0;
837                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
838                         *dotdot = '^';
839         }
841         local_flags = 0;
842         if (*arg == '^') {
843                 local_flags = UNINTERESTING;
844                 arg++;
845         }
846         if (get_sha1_with_mode(arg, sha1, &mode))
847                 return -1;
848         if (!cant_be_filename)
849                 verify_non_filename(revs->prefix, arg);
850         object = get_reference(revs, arg, sha1, flags ^ local_flags);
851         add_pending_object_with_mode(revs, object, arg, mode);
852         return 0;
855 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
857         if (!revs->grep_filter) {
858                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
859                 opt->status_only = 1;
860                 opt->pattern_tail = &(opt->pattern_list);
861                 opt->regflags = REG_NEWLINE;
862                 revs->grep_filter = opt;
863         }
864         append_grep_pattern(revs->grep_filter, ptn,
865                             "command line", 0, what);
868 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
870         char *pat;
871         const char *prefix;
872         int patlen, fldlen;
874         fldlen = strlen(field);
875         patlen = strlen(pattern);
876         pat = xmalloc(patlen + fldlen + 10);
877         prefix = ".*";
878         if (*pattern == '^') {
879                 prefix = "";
880                 pattern++;
881         }
882         sprintf(pat, "^%s %s%s", field, prefix, pattern);
883         add_grep(revs, pat, GREP_PATTERN_HEAD);
886 static void add_message_grep(struct rev_info *revs, const char *pattern)
888         add_grep(revs, pattern, GREP_PATTERN_BODY);
891 static void add_ignore_packed(struct rev_info *revs, const char *name)
893         int num = ++revs->num_ignore_packed;
895         revs->ignore_packed = xrealloc(revs->ignore_packed,
896                                        sizeof(const char **) * (num + 1));
897         revs->ignore_packed[num-1] = name;
898         revs->ignore_packed[num] = NULL;
901 /*
902  * Parse revision information, filling in the "rev_info" structure,
903  * and removing the used arguments from the argument list.
904  *
905  * Returns the number of arguments left that weren't recognized
906  * (which are also moved to the head of the argument list)
907  */
908 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
910         int i, flags, seen_dashdash, show_merge;
911         const char **unrecognized = argv + 1;
912         int left = 1;
913         int all_match = 0;
914         int regflags = 0;
916         /* First, search for "--" */
917         seen_dashdash = 0;
918         for (i = 1; i < argc; i++) {
919                 const char *arg = argv[i];
920                 if (strcmp(arg, "--"))
921                         continue;
922                 argv[i] = NULL;
923                 argc = i;
924                 if (argv[i + 1])
925                         revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
926                 seen_dashdash = 1;
927                 break;
928         }
930         flags = show_merge = 0;
931         for (i = 1; i < argc; i++) {
932                 const char *arg = argv[i];
933                 if (*arg == '-') {
934                         int opts;
935                         if (!prefixcmp(arg, "--max-count=")) {
936                                 revs->max_count = atoi(arg + 12);
937                                 continue;
938                         }
939                         if (!prefixcmp(arg, "--skip=")) {
940                                 revs->skip_count = atoi(arg + 7);
941                                 continue;
942                         }
943                         /* accept -<digit>, like traditional "head" */
944                         if ((*arg == '-') && isdigit(arg[1])) {
945                                 revs->max_count = atoi(arg + 1);
946                                 continue;
947                         }
948                         if (!strcmp(arg, "-n")) {
949                                 if (argc <= i + 1)
950                                         die("-n requires an argument");
951                                 revs->max_count = atoi(argv[++i]);
952                                 continue;
953                         }
954                         if (!prefixcmp(arg, "-n")) {
955                                 revs->max_count = atoi(arg + 2);
956                                 continue;
957                         }
958                         if (!prefixcmp(arg, "--max-age=")) {
959                                 revs->max_age = atoi(arg + 10);
960                                 continue;
961                         }
962                         if (!prefixcmp(arg, "--since=")) {
963                                 revs->max_age = approxidate(arg + 8);
964                                 continue;
965                         }
966                         if (!prefixcmp(arg, "--after=")) {
967                                 revs->max_age = approxidate(arg + 8);
968                                 continue;
969                         }
970                         if (!prefixcmp(arg, "--min-age=")) {
971                                 revs->min_age = atoi(arg + 10);
972                                 continue;
973                         }
974                         if (!prefixcmp(arg, "--before=")) {
975                                 revs->min_age = approxidate(arg + 9);
976                                 continue;
977                         }
978                         if (!prefixcmp(arg, "--until=")) {
979                                 revs->min_age = approxidate(arg + 8);
980                                 continue;
981                         }
982                         if (!strcmp(arg, "--all")) {
983                                 handle_all(revs, flags);
984                                 continue;
985                         }
986                         if (!strcmp(arg, "--first-parent")) {
987                                 revs->first_parent_only = 1;
988                                 continue;
989                         }
990                         if (!strcmp(arg, "--reflog")) {
991                                 handle_reflog(revs, flags);
992                                 continue;
993                         }
994                         if (!strcmp(arg, "-g") ||
995                                         !strcmp(arg, "--walk-reflogs")) {
996                                 init_reflog_walk(&revs->reflog_info);
997                                 continue;
998                         }
999                         if (!strcmp(arg, "--not")) {
1000                                 flags ^= UNINTERESTING;
1001                                 continue;
1002                         }
1003                         if (!strcmp(arg, "--default")) {
1004                                 if (++i >= argc)
1005                                         die("bad --default argument");
1006                                 def = argv[i];
1007                                 continue;
1008                         }
1009                         if (!strcmp(arg, "--merge")) {
1010                                 show_merge = 1;
1011                                 continue;
1012                         }
1013                         if (!strcmp(arg, "--topo-order")) {
1014                                 revs->topo_order = 1;
1015                                 continue;
1016                         }
1017                         if (!strcmp(arg, "--date-order")) {
1018                                 revs->lifo = 0;
1019                                 revs->topo_order = 1;
1020                                 continue;
1021                         }
1022                         if (!prefixcmp(arg, "--early-output")) {
1023                                 int count = 100;
1024                                 switch (arg[14]) {
1025                                 case '=':
1026                                         count = atoi(arg+15);
1027                                         /* Fallthrough */
1028                                 case 0:
1029                                         revs->topo_order = 1;
1030                                         revs->early_output = count;
1031                                         continue;
1032                                 }
1033                         }
1034                         if (!strcmp(arg, "--parents")) {
1035                                 revs->parents = 1;
1036                                 continue;
1037                         }
1038                         if (!strcmp(arg, "--dense")) {
1039                                 revs->dense = 1;
1040                                 continue;
1041                         }
1042                         if (!strcmp(arg, "--sparse")) {
1043                                 revs->dense = 0;
1044                                 continue;
1045                         }
1046                         if (!strcmp(arg, "--remove-empty")) {
1047                                 revs->remove_empty_trees = 1;
1048                                 continue;
1049                         }
1050                         if (!strcmp(arg, "--no-merges")) {
1051                                 revs->no_merges = 1;
1052                                 continue;
1053                         }
1054                         if (!strcmp(arg, "--boundary")) {
1055                                 revs->boundary = 1;
1056                                 continue;
1057                         }
1058                         if (!strcmp(arg, "--left-right")) {
1059                                 revs->left_right = 1;
1060                                 continue;
1061                         }
1062                         if (!strcmp(arg, "--cherry-pick")) {
1063                                 revs->cherry_pick = 1;
1064                                 revs->limited = 1;
1065                                 continue;
1066                         }
1067                         if (!strcmp(arg, "--objects")) {
1068                                 revs->tag_objects = 1;
1069                                 revs->tree_objects = 1;
1070                                 revs->blob_objects = 1;
1071                                 continue;
1072                         }
1073                         if (!strcmp(arg, "--objects-edge")) {
1074                                 revs->tag_objects = 1;
1075                                 revs->tree_objects = 1;
1076                                 revs->blob_objects = 1;
1077                                 revs->edge_hint = 1;
1078                                 continue;
1079                         }
1080                         if (!strcmp(arg, "--unpacked")) {
1081                                 revs->unpacked = 1;
1082                                 free(revs->ignore_packed);
1083                                 revs->ignore_packed = NULL;
1084                                 revs->num_ignore_packed = 0;
1085                                 continue;
1086                         }
1087                         if (!prefixcmp(arg, "--unpacked=")) {
1088                                 revs->unpacked = 1;
1089                                 add_ignore_packed(revs, arg+11);
1090                                 continue;
1091                         }
1092                         if (!strcmp(arg, "-r")) {
1093                                 revs->diff = 1;
1094                                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1095                                 continue;
1096                         }
1097                         if (!strcmp(arg, "-t")) {
1098                                 revs->diff = 1;
1099                                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1100                                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1101                                 continue;
1102                         }
1103                         if (!strcmp(arg, "-m")) {
1104                                 revs->ignore_merges = 0;
1105                                 continue;
1106                         }
1107                         if (!strcmp(arg, "-c")) {
1108                                 revs->diff = 1;
1109                                 revs->dense_combined_merges = 0;
1110                                 revs->combine_merges = 1;
1111                                 continue;
1112                         }
1113                         if (!strcmp(arg, "--cc")) {
1114                                 revs->diff = 1;
1115                                 revs->dense_combined_merges = 1;
1116                                 revs->combine_merges = 1;
1117                                 continue;
1118                         }
1119                         if (!strcmp(arg, "-v")) {
1120                                 revs->verbose_header = 1;
1121                                 continue;
1122                         }
1123                         if (!prefixcmp(arg, "--pretty")) {
1124                                 revs->verbose_header = 1;
1125                                 revs->commit_format = get_commit_format(arg+8);
1126                                 continue;
1127                         }
1128                         if (!strcmp(arg, "--root")) {
1129                                 revs->show_root_diff = 1;
1130                                 continue;
1131                         }
1132                         if (!strcmp(arg, "--no-commit-id")) {
1133                                 revs->no_commit_id = 1;
1134                                 continue;
1135                         }
1136                         if (!strcmp(arg, "--always")) {
1137                                 revs->always_show_header = 1;
1138                                 continue;
1139                         }
1140                         if (!strcmp(arg, "--no-abbrev")) {
1141                                 revs->abbrev = 0;
1142                                 continue;
1143                         }
1144                         if (!strcmp(arg, "--abbrev")) {
1145                                 revs->abbrev = DEFAULT_ABBREV;
1146                                 continue;
1147                         }
1148                         if (!prefixcmp(arg, "--abbrev=")) {
1149                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1150                                 if (revs->abbrev < MINIMUM_ABBREV)
1151                                         revs->abbrev = MINIMUM_ABBREV;
1152                                 else if (revs->abbrev > 40)
1153                                         revs->abbrev = 40;
1154                                 continue;
1155                         }
1156                         if (!strcmp(arg, "--abbrev-commit")) {
1157                                 revs->abbrev_commit = 1;
1158                                 continue;
1159                         }
1160                         if (!strcmp(arg, "--full-diff")) {
1161                                 revs->diff = 1;
1162                                 revs->full_diff = 1;
1163                                 continue;
1164                         }
1165                         if (!strcmp(arg, "--full-history")) {
1166                                 revs->simplify_history = 0;
1167                                 continue;
1168                         }
1169                         if (!strcmp(arg, "--relative-date")) {
1170                                 revs->date_mode = DATE_RELATIVE;
1171                                 continue;
1172                         }
1173                         if (!strncmp(arg, "--date=", 7)) {
1174                                 revs->date_mode = parse_date_format(arg + 7);
1175                                 continue;
1176                         }
1177                         if (!strcmp(arg, "--log-size")) {
1178                                 revs->show_log_size = 1;
1179                                 continue;
1180                         }
1182                         /*
1183                          * Grepping the commit log
1184                          */
1185                         if (!prefixcmp(arg, "--author=")) {
1186                                 add_header_grep(revs, "author", arg+9);
1187                                 continue;
1188                         }
1189                         if (!prefixcmp(arg, "--committer=")) {
1190                                 add_header_grep(revs, "committer", arg+12);
1191                                 continue;
1192                         }
1193                         if (!prefixcmp(arg, "--grep=")) {
1194                                 add_message_grep(revs, arg+7);
1195                                 continue;
1196                         }
1197                         if (!strcmp(arg, "--extended-regexp") ||
1198                             !strcmp(arg, "-E")) {
1199                                 regflags |= REG_EXTENDED;
1200                                 continue;
1201                         }
1202                         if (!strcmp(arg, "--regexp-ignore-case") ||
1203                             !strcmp(arg, "-i")) {
1204                                 regflags |= REG_ICASE;
1205                                 continue;
1206                         }
1207                         if (!strcmp(arg, "--all-match")) {
1208                                 all_match = 1;
1209                                 continue;
1210                         }
1211                         if (!prefixcmp(arg, "--encoding=")) {
1212                                 arg += 11;
1213                                 if (strcmp(arg, "none"))
1214                                         git_log_output_encoding = xstrdup(arg);
1215                                 else
1216                                         git_log_output_encoding = "";
1217                                 continue;
1218                         }
1219                         if (!strcmp(arg, "--reverse")) {
1220                                 revs->reverse ^= 1;
1221                                 continue;
1222                         }
1223                         if (!strcmp(arg, "--no-walk")) {
1224                                 revs->no_walk = 1;
1225                                 continue;
1226                         }
1227                         if (!strcmp(arg, "--do-walk")) {
1228                                 revs->no_walk = 0;
1229                                 continue;
1230                         }
1232                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1233                         if (opts > 0) {
1234                                 i += opts - 1;
1235                                 continue;
1236                         }
1237                         *unrecognized++ = arg;
1238                         left++;
1239                         continue;
1240                 }
1242                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1243                         int j;
1244                         if (seen_dashdash || *arg == '^')
1245                                 die("bad revision '%s'", arg);
1247                         /* If we didn't have a "--":
1248                          * (1) all filenames must exist;
1249                          * (2) all rev-args must not be interpretable
1250                          *     as a valid filename.
1251                          * but the latter we have checked in the main loop.
1252                          */
1253                         for (j = i; j < argc; j++)
1254                                 verify_filename(revs->prefix, argv[j]);
1256                         revs->prune_data = get_pathspec(revs->prefix,
1257                                                         argv + i);
1258                         break;
1259                 }
1260         }
1262         if (revs->grep_filter)
1263                 revs->grep_filter->regflags |= regflags;
1265         if (show_merge)
1266                 prepare_show_merge(revs);
1267         if (def && !revs->pending.nr) {
1268                 unsigned char sha1[20];
1269                 struct object *object;
1270                 unsigned mode;
1271                 if (get_sha1_with_mode(def, sha1, &mode))
1272                         die("bad default revision '%s'", def);
1273                 object = get_reference(revs, def, sha1, 0);
1274                 add_pending_object_with_mode(revs, object, def, mode);
1275         }
1277         /* Did the user ask for any diff output? Run the diff! */
1278         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1279                 revs->diff = 1;
1281         /* Pickaxe and rename following needs diffs */
1282         if (revs->diffopt.pickaxe || DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1283                 revs->diff = 1;
1285         if (revs->topo_order)
1286                 revs->limited = 1;
1288         if (revs->prune_data) {
1289                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1290                 /* Can't prune commits with rename following: the paths change.. */
1291                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1292                         revs->prune = 1;
1293                 if (!revs->full_diff)
1294                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1295         }
1296         if (revs->combine_merges) {
1297                 revs->ignore_merges = 0;
1298                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1299                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1300         }
1301         revs->diffopt.abbrev = revs->abbrev;
1302         if (diff_setup_done(&revs->diffopt) < 0)
1303                 die("diff_setup_done failed");
1305         if (revs->grep_filter) {
1306                 revs->grep_filter->all_match = all_match;
1307                 compile_grep_patterns(revs->grep_filter);
1308         }
1310         if (revs->reverse && revs->reflog_info)
1311                 die("cannot combine --reverse with --walk-reflogs");
1313         return left;
1316 int prepare_revision_walk(struct rev_info *revs)
1318         int nr = revs->pending.nr;
1319         struct object_array_entry *e, *list;
1321         e = list = revs->pending.objects;
1322         revs->pending.nr = 0;
1323         revs->pending.alloc = 0;
1324         revs->pending.objects = NULL;
1325         while (--nr >= 0) {
1326                 struct commit *commit = handle_commit(revs, e->item, e->name);
1327                 if (commit) {
1328                         if (!(commit->object.flags & SEEN)) {
1329                                 commit->object.flags |= SEEN;
1330                                 insert_by_date(commit, &revs->commits);
1331                         }
1332                 }
1333                 e++;
1334         }
1335         free(list);
1337         if (revs->no_walk)
1338                 return 0;
1339         if (revs->limited)
1340                 if (limit_list(revs) < 0)
1341                         return -1;
1342         if (revs->topo_order)
1343                 sort_in_topological_order(&revs->commits, revs->lifo);
1344         return 0;
1347 enum rewrite_result {
1348         rewrite_one_ok,
1349         rewrite_one_noparents,
1350         rewrite_one_error,
1351 };
1353 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1355         for (;;) {
1356                 struct commit *p = *pp;
1357                 if (!revs->limited)
1358                         if (add_parents_to_list(revs, p, &revs->commits) < 0)
1359                                 return rewrite_one_error;
1360                 if (p->parents && p->parents->next)
1361                         return rewrite_one_ok;
1362                 if (p->object.flags & UNINTERESTING)
1363                         return rewrite_one_ok;
1364                 if (!(p->object.flags & TREESAME))
1365                         return rewrite_one_ok;
1366                 if (!p->parents)
1367                         return rewrite_one_noparents;
1368                 *pp = p->parents->item;
1369         }
1372 static void remove_duplicate_parents(struct commit *commit)
1374         struct commit_list **pp, *p;
1376         /* Examine existing parents while marking ones we have seen... */
1377         pp = &commit->parents;
1378         while ((p = *pp) != NULL) {
1379                 struct commit *parent = p->item;
1380                 if (parent->object.flags & TMP_MARK) {
1381                         *pp = p->next;
1382                         continue;
1383                 }
1384                 parent->object.flags |= TMP_MARK;
1385                 pp = &p->next;
1386         }
1387         /* ... and clear the temporary mark */
1388         for (p = commit->parents; p; p = p->next)
1389                 p->item->object.flags &= ~TMP_MARK;
1392 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1394         struct commit_list **pp = &commit->parents;
1395         while (*pp) {
1396                 struct commit_list *parent = *pp;
1397                 switch (rewrite_one(revs, &parent->item)) {
1398                 case rewrite_one_ok:
1399                         break;
1400                 case rewrite_one_noparents:
1401                         *pp = parent->next;
1402                         continue;
1403                 case rewrite_one_error:
1404                         return -1;
1405                 }
1406                 pp = &parent->next;
1407         }
1408         remove_duplicate_parents(commit);
1409         return 0;
1412 static int commit_match(struct commit *commit, struct rev_info *opt)
1414         if (!opt->grep_filter)
1415                 return 1;
1416         return grep_buffer(opt->grep_filter,
1417                            NULL, /* we say nothing, not even filename */
1418                            commit->buffer, strlen(commit->buffer));
1421 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1423         if (commit->object.flags & SHOWN)
1424                 return commit_ignore;
1425         if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1426                 return commit_ignore;
1427         if (commit->object.flags & UNINTERESTING)
1428                 return commit_ignore;
1429         if (revs->min_age != -1 && (commit->date > revs->min_age))
1430                 return commit_ignore;
1431         if (revs->no_merges && commit->parents && commit->parents->next)
1432                 return commit_ignore;
1433         if (!commit_match(commit, revs))
1434                 return commit_ignore;
1435         if (revs->prune && revs->dense) {
1436                 /* Commit without changes? */
1437                 if (commit->object.flags & TREESAME) {
1438                         /* drop merges unless we want parenthood */
1439                         if (!revs->parents)
1440                                 return commit_ignore;
1441                         /* non-merge - always ignore it */
1442                         if (!commit->parents || !commit->parents->next)
1443                                 return commit_ignore;
1444                 }
1445                 if (revs->parents && rewrite_parents(revs, commit) < 0)
1446                         return commit_error;
1447         }
1448         return commit_show;
1451 static struct commit *get_revision_1(struct rev_info *revs)
1453         if (!revs->commits)
1454                 return NULL;
1456         do {
1457                 struct commit_list *entry = revs->commits;
1458                 struct commit *commit = entry->item;
1460                 revs->commits = entry->next;
1461                 free(entry);
1463                 if (revs->reflog_info)
1464                         fake_reflog_parent(revs->reflog_info, commit);
1466                 /*
1467                  * If we haven't done the list limiting, we need to look at
1468                  * the parents here. We also need to do the date-based limiting
1469                  * that we'd otherwise have done in limit_list().
1470                  */
1471                 if (!revs->limited) {
1472                         if (revs->max_age != -1 &&
1473                             (commit->date < revs->max_age))
1474                                 continue;
1475                         if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1476                                 return NULL;
1477                 }
1479                 switch (simplify_commit(revs, commit)) {
1480                 case commit_ignore:
1481                         continue;
1482                 case commit_error:
1483                         return NULL;
1484                 default:
1485                         return commit;
1486                 }
1487         } while (revs->commits);
1488         return NULL;
1491 static void gc_boundary(struct object_array *array)
1493         unsigned nr = array->nr;
1494         unsigned alloc = array->alloc;
1495         struct object_array_entry *objects = array->objects;
1497         if (alloc <= nr) {
1498                 unsigned i, j;
1499                 for (i = j = 0; i < nr; i++) {
1500                         if (objects[i].item->flags & SHOWN)
1501                                 continue;
1502                         if (i != j)
1503                                 objects[j] = objects[i];
1504                         j++;
1505                 }
1506                 for (i = j; i < nr; i++)
1507                         objects[i].item = NULL;
1508                 array->nr = j;
1509         }
1512 struct commit *get_revision(struct rev_info *revs)
1514         struct commit *c = NULL;
1515         struct commit_list *l;
1517         if (revs->boundary == 2) {
1518                 unsigned i;
1519                 struct object_array *array = &revs->boundary_commits;
1520                 struct object_array_entry *objects = array->objects;
1521                 for (i = 0; i < array->nr; i++) {
1522                         c = (struct commit *)(objects[i].item);
1523                         if (!c)
1524                                 continue;
1525                         if (!(c->object.flags & CHILD_SHOWN))
1526                                 continue;
1527                         if (!(c->object.flags & SHOWN))
1528                                 break;
1529                 }
1530                 if (array->nr <= i)
1531                         return NULL;
1533                 c->object.flags |= SHOWN | BOUNDARY;
1534                 return c;
1535         }
1537         if (revs->reverse) {
1538                 int limit = -1;
1540                 if (0 <= revs->max_count) {
1541                         limit = revs->max_count;
1542                         if (0 < revs->skip_count)
1543                                 limit += revs->skip_count;
1544                 }
1545                 l = NULL;
1546                 while ((c = get_revision_1(revs))) {
1547                         commit_list_insert(c, &l);
1548                         if ((0 < limit) && !--limit)
1549                                 break;
1550                 }
1551                 revs->commits = l;
1552                 revs->reverse = 0;
1553                 revs->max_count = -1;
1554                 c = NULL;
1555         }
1557         /*
1558          * Now pick up what they want to give us
1559          */
1560         c = get_revision_1(revs);
1561         if (c) {
1562                 while (0 < revs->skip_count) {
1563                         revs->skip_count--;
1564                         c = get_revision_1(revs);
1565                         if (!c)
1566                                 break;
1567                 }
1568         }
1570         /*
1571          * Check the max_count.
1572          */
1573         switch (revs->max_count) {
1574         case -1:
1575                 break;
1576         case 0:
1577                 c = NULL;
1578                 break;
1579         default:
1580                 revs->max_count--;
1581         }
1583         if (c)
1584                 c->object.flags |= SHOWN;
1586         if (!revs->boundary) {
1587                 return c;
1588         }
1590         if (!c) {
1591                 /*
1592                  * get_revision_1() runs out the commits, and
1593                  * we are done computing the boundaries.
1594                  * switch to boundary commits output mode.
1595                  */
1596                 revs->boundary = 2;
1597                 return get_revision(revs);
1598         }
1600         /*
1601          * boundary commits are the commits that are parents of the
1602          * ones we got from get_revision_1() but they themselves are
1603          * not returned from get_revision_1().  Before returning
1604          * 'c', we need to mark its parents that they could be boundaries.
1605          */
1607         for (l = c->parents; l; l = l->next) {
1608                 struct object *p;
1609                 p = &(l->item->object);
1610                 if (p->flags & (CHILD_SHOWN | SHOWN))
1611                         continue;
1612                 p->flags |= CHILD_SHOWN;
1613                 gc_boundary(&revs->boundary_commits);
1614                 add_object_array(p, NULL, &revs->boundary_commits);
1615         }
1617         return c;