Merge branch 'jt/curl-verbose-on-trace-curl'
[git] / revision.c
1 #include "cache.h"
2 #include "object-store.h"
3 #include "tag.h"
4 #include "blob.h"
5 #include "tree.h"
6 #include "commit.h"
7 #include "diff.h"
8 #include "refs.h"
9 #include "revision.h"
10 #include "repository.h"
11 #include "graph.h"
12 #include "grep.h"
13 #include "reflog-walk.h"
14 #include "patch-ids.h"
15 #include "decorate.h"
16 #include "log-tree.h"
17 #include "string-list.h"
18 #include "line-log.h"
19 #include "mailmap.h"
20 #include "commit-slab.h"
21 #include "dir.h"
22 #include "cache-tree.h"
23 #include "bisect.h"
24 #include "packfile.h"
25 #include "worktree.h"
26 #include "argv-array.h"
27 #include "commit-reach.h"
28 #include "commit-graph.h"
29 #include "prio-queue.h"
30 #include "hashmap.h"
31 #include "utf8.h"
32 #include "bloom.h"
33 #include "json-writer.h"
34
35 volatile show_early_output_fn_t show_early_output;
36
37 static const char *term_bad;
38 static const char *term_good;
39
40 implement_shared_commit_slab(revision_sources, char *);
41
42 static inline int want_ancestry(const struct rev_info *revs);
43
44 void show_object_with_name(FILE *out, struct object *obj, const char *name)
45 {
46         const char *p;
47
48         fprintf(out, "%s ", oid_to_hex(&obj->oid));
49         for (p = name; *p && *p != '\n'; p++)
50                 fputc(*p, out);
51         fputc('\n', out);
52 }
53
54 static void mark_blob_uninteresting(struct blob *blob)
55 {
56         if (!blob)
57                 return;
58         if (blob->object.flags & UNINTERESTING)
59                 return;
60         blob->object.flags |= UNINTERESTING;
61 }
62
63 static void mark_tree_contents_uninteresting(struct repository *r,
64                                              struct tree *tree)
65 {
66         struct tree_desc desc;
67         struct name_entry entry;
68
69         if (parse_tree_gently(tree, 1) < 0)
70                 return;
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(r, lookup_tree(r, &entry.oid));
77                         break;
78                 case OBJ_BLOB:
79                         mark_blob_uninteresting(lookup_blob(r, &entry.oid));
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(tree);
92 }
93
94 void mark_tree_uninteresting(struct repository *r, struct tree *tree)
95 {
96         struct object *obj;
97
98         if (!tree)
99                 return;
100
101         obj = &tree->object;
102         if (obj->flags & UNINTERESTING)
103                 return;
104         obj->flags |= UNINTERESTING;
105         mark_tree_contents_uninteresting(r, tree);
106 }
107
108 struct path_and_oids_entry {
109         struct hashmap_entry ent;
110         char *path;
111         struct oidset trees;
112 };
113
114 static int path_and_oids_cmp(const void *hashmap_cmp_fn_data,
115                              const struct hashmap_entry *eptr,
116                              const struct hashmap_entry *entry_or_key,
117                              const void *keydata)
118 {
119         const struct path_and_oids_entry *e1, *e2;
120
121         e1 = container_of(eptr, const struct path_and_oids_entry, ent);
122         e2 = container_of(entry_or_key, const struct path_and_oids_entry, ent);
123
124         return strcmp(e1->path, e2->path);
125 }
126
127 static void paths_and_oids_init(struct hashmap *map)
128 {
129         hashmap_init(map, path_and_oids_cmp, NULL, 0);
130 }
131
132 static void paths_and_oids_clear(struct hashmap *map)
133 {
134         struct hashmap_iter iter;
135         struct path_and_oids_entry *entry;
136
137         hashmap_for_each_entry(map, &iter, entry, ent /* member name */) {
138                 oidset_clear(&entry->trees);
139                 free(entry->path);
140         }
141
142         hashmap_free_entries(map, struct path_and_oids_entry, ent);
143 }
144
145 static void paths_and_oids_insert(struct hashmap *map,
146                                   const char *path,
147                                   const struct object_id *oid)
148 {
149         int hash = strhash(path);
150         struct path_and_oids_entry key;
151         struct path_and_oids_entry *entry;
152
153         hashmap_entry_init(&key.ent, hash);
154
155         /* use a shallow copy for the lookup */
156         key.path = (char *)path;
157         oidset_init(&key.trees, 0);
158
159         entry = hashmap_get_entry(map, &key, ent, NULL);
160         if (!entry) {
161                 entry = xcalloc(1, sizeof(struct path_and_oids_entry));
162                 hashmap_entry_init(&entry->ent, hash);
163                 entry->path = xstrdup(key.path);
164                 oidset_init(&entry->trees, 16);
165                 hashmap_put(map, &entry->ent);
166         }
167
168         oidset_insert(&entry->trees, oid);
169 }
170
171 static void add_children_by_path(struct repository *r,
172                                  struct tree *tree,
173                                  struct hashmap *map)
174 {
175         struct tree_desc desc;
176         struct name_entry entry;
177
178         if (!tree)
179                 return;
180
181         if (parse_tree_gently(tree, 1) < 0)
182                 return;
183
184         init_tree_desc(&desc, tree->buffer, tree->size);
185         while (tree_entry(&desc, &entry)) {
186                 switch (object_type(entry.mode)) {
187                 case OBJ_TREE:
188                         paths_and_oids_insert(map, entry.path, &entry.oid);
189
190                         if (tree->object.flags & UNINTERESTING) {
191                                 struct tree *child = lookup_tree(r, &entry.oid);
192                                 if (child)
193                                         child->object.flags |= UNINTERESTING;
194                         }
195                         break;
196                 case OBJ_BLOB:
197                         if (tree->object.flags & UNINTERESTING) {
198                                 struct blob *child = lookup_blob(r, &entry.oid);
199                                 if (child)
200                                         child->object.flags |= UNINTERESTING;
201                         }
202                         break;
203                 default:
204                         /* Subproject commit - not in this repository */
205                         break;
206                 }
207         }
208
209         free_tree_buffer(tree);
210 }
211
212 void mark_trees_uninteresting_sparse(struct repository *r,
213                                      struct oidset *trees)
214 {
215         unsigned has_interesting = 0, has_uninteresting = 0;
216         struct hashmap map;
217         struct hashmap_iter map_iter;
218         struct path_and_oids_entry *entry;
219         struct object_id *oid;
220         struct oidset_iter iter;
221
222         oidset_iter_init(trees, &iter);
223         while ((!has_interesting || !has_uninteresting) &&
224                (oid = oidset_iter_next(&iter))) {
225                 struct tree *tree = lookup_tree(r, oid);
226
227                 if (!tree)
228                         continue;
229
230                 if (tree->object.flags & UNINTERESTING)
231                         has_uninteresting = 1;
232                 else
233                         has_interesting = 1;
234         }
235
236         /* Do not walk unless we have both types of trees. */
237         if (!has_uninteresting || !has_interesting)
238                 return;
239
240         paths_and_oids_init(&map);
241
242         oidset_iter_init(trees, &iter);
243         while ((oid = oidset_iter_next(&iter))) {
244                 struct tree *tree = lookup_tree(r, oid);
245                 add_children_by_path(r, tree, &map);
246         }
247
248         hashmap_for_each_entry(&map, &map_iter, entry, ent /* member name */)
249                 mark_trees_uninteresting_sparse(r, &entry->trees);
250
251         paths_and_oids_clear(&map);
252 }
253
254 struct commit_stack {
255         struct commit **items;
256         size_t nr, alloc;
257 };
258 #define COMMIT_STACK_INIT { NULL, 0, 0 }
259
260 static void commit_stack_push(struct commit_stack *stack, struct commit *commit)
261 {
262         ALLOC_GROW(stack->items, stack->nr + 1, stack->alloc);
263         stack->items[stack->nr++] = commit;
264 }
265
266 static struct commit *commit_stack_pop(struct commit_stack *stack)
267 {
268         return stack->nr ? stack->items[--stack->nr] : NULL;
269 }
270
271 static void commit_stack_clear(struct commit_stack *stack)
272 {
273         FREE_AND_NULL(stack->items);
274         stack->nr = stack->alloc = 0;
275 }
276
277 static void mark_one_parent_uninteresting(struct commit *commit,
278                                           struct commit_stack *pending)
279 {
280         struct commit_list *l;
281
282         if (commit->object.flags & UNINTERESTING)
283                 return;
284         commit->object.flags |= UNINTERESTING;
285
286         /*
287          * Normally we haven't parsed the parent
288          * yet, so we won't have a parent of a parent
289          * here. However, it may turn out that we've
290          * reached this commit some other way (where it
291          * wasn't uninteresting), in which case we need
292          * to mark its parents recursively too..
293          */
294         for (l = commit->parents; l; l = l->next)
295                 commit_stack_push(pending, l->item);
296 }
297
298 void mark_parents_uninteresting(struct commit *commit)
299 {
300         struct commit_stack pending = COMMIT_STACK_INIT;
301         struct commit_list *l;
302
303         for (l = commit->parents; l; l = l->next)
304                 mark_one_parent_uninteresting(l->item, &pending);
305
306         while (pending.nr > 0)
307                 mark_one_parent_uninteresting(commit_stack_pop(&pending),
308                                               &pending);
309
310         commit_stack_clear(&pending);
311 }
312
313 static void add_pending_object_with_path(struct rev_info *revs,
314                                          struct object *obj,
315                                          const char *name, unsigned mode,
316                                          const char *path)
317 {
318         if (!obj)
319                 return;
320         if (revs->no_walk && (obj->flags & UNINTERESTING))
321                 revs->no_walk = 0;
322         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
323                 struct strbuf buf = STRBUF_INIT;
324                 int len = interpret_branch_name(name, 0, &buf, 0);
325
326                 if (0 < len && name[len] && buf.len)
327                         strbuf_addstr(&buf, name + len);
328                 add_reflog_for_walk(revs->reflog_info,
329                                     (struct commit *)obj,
330                                     buf.buf[0] ? buf.buf: name);
331                 strbuf_release(&buf);
332                 return; /* do not add the commit itself */
333         }
334         add_object_array_with_path(obj, name, &revs->pending, mode, path);
335 }
336
337 static void add_pending_object_with_mode(struct rev_info *revs,
338                                          struct object *obj,
339                                          const char *name, unsigned mode)
340 {
341         add_pending_object_with_path(revs, obj, name, mode, NULL);
342 }
343
344 void add_pending_object(struct rev_info *revs,
345                         struct object *obj, const char *name)
346 {
347         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
348 }
349
350 void add_head_to_pending(struct rev_info *revs)
351 {
352         struct object_id oid;
353         struct object *obj;
354         if (get_oid("HEAD", &oid))
355                 return;
356         obj = parse_object(revs->repo, &oid);
357         if (!obj)
358                 return;
359         add_pending_object(revs, obj, "HEAD");
360 }
361
362 static struct object *get_reference(struct rev_info *revs, const char *name,
363                                     const struct object_id *oid,
364                                     unsigned int flags)
365 {
366         struct object *object;
367
368         /*
369          * If the repository has commit graphs, repo_parse_commit() avoids
370          * reading the object buffer, so use it whenever possible.
371          */
372         if (oid_object_info(revs->repo, oid, NULL) == OBJ_COMMIT) {
373                 struct commit *c = lookup_commit(revs->repo, oid);
374                 if (!repo_parse_commit(revs->repo, c))
375                         object = (struct object *) c;
376                 else
377                         object = NULL;
378         } else {
379                 object = parse_object(revs->repo, oid);
380         }
381
382         if (!object) {
383                 if (revs->ignore_missing)
384                         return object;
385                 if (revs->exclude_promisor_objects && is_promisor_object(oid))
386                         return NULL;
387                 die("bad object %s", name);
388         }
389         object->flags |= flags;
390         return object;
391 }
392
393 void add_pending_oid(struct rev_info *revs, const char *name,
394                       const struct object_id *oid, unsigned int flags)
395 {
396         struct object *object = get_reference(revs, name, oid, flags);
397         add_pending_object(revs, object, name);
398 }
399
400 static struct commit *handle_commit(struct rev_info *revs,
401                                     struct object_array_entry *entry)
402 {
403         struct object *object = entry->item;
404         const char *name = entry->name;
405         const char *path = entry->path;
406         unsigned int mode = entry->mode;
407         unsigned long flags = object->flags;
408
409         /*
410          * Tag object? Look what it points to..
411          */
412         while (object->type == OBJ_TAG) {
413                 struct tag *tag = (struct tag *) object;
414                 if (revs->tag_objects && !(flags & UNINTERESTING))
415                         add_pending_object(revs, object, tag->tag);
416                 object = parse_object(revs->repo, get_tagged_oid(tag));
417                 if (!object) {
418                         if (revs->ignore_missing_links || (flags & UNINTERESTING))
419                                 return NULL;
420                         if (revs->exclude_promisor_objects &&
421                             is_promisor_object(&tag->tagged->oid))
422                                 return NULL;
423                         die("bad object %s", oid_to_hex(&tag->tagged->oid));
424                 }
425                 object->flags |= flags;
426                 /*
427                  * We'll handle the tagged object by looping or dropping
428                  * through to the non-tag handlers below. Do not
429                  * propagate path data from the tag's pending entry.
430                  */
431                 path = NULL;
432                 mode = 0;
433         }
434
435         /*
436          * Commit object? Just return it, we'll do all the complex
437          * reachability crud.
438          */
439         if (object->type == OBJ_COMMIT) {
440                 struct commit *commit = (struct commit *)object;
441
442                 if (parse_commit(commit) < 0)
443                         die("unable to parse commit %s", name);
444                 if (flags & UNINTERESTING) {
445                         mark_parents_uninteresting(commit);
446
447                         if (!revs->topo_order || !generation_numbers_enabled(the_repository))
448                                 revs->limited = 1;
449                 }
450                 if (revs->sources) {
451                         char **slot = revision_sources_at(revs->sources, commit);
452
453                         if (!*slot)
454                                 *slot = xstrdup(name);
455                 }
456                 return commit;
457         }
458
459         /*
460          * Tree object? Either mark it uninteresting, or add it
461          * to the list of objects to look at later..
462          */
463         if (object->type == OBJ_TREE) {
464                 struct tree *tree = (struct tree *)object;
465                 if (!revs->tree_objects)
466                         return NULL;
467                 if (flags & UNINTERESTING) {
468                         mark_tree_contents_uninteresting(revs->repo, tree);
469                         return NULL;
470                 }
471                 add_pending_object_with_path(revs, object, name, mode, path);
472                 return NULL;
473         }
474
475         /*
476          * Blob object? You know the drill by now..
477          */
478         if (object->type == OBJ_BLOB) {
479                 if (!revs->blob_objects)
480                         return NULL;
481                 if (flags & UNINTERESTING)
482                         return NULL;
483                 add_pending_object_with_path(revs, object, name, mode, path);
484                 return NULL;
485         }
486         die("%s is unknown object", name);
487 }
488
489 static int everybody_uninteresting(struct commit_list *orig,
490                                    struct commit **interesting_cache)
491 {
492         struct commit_list *list = orig;
493
494         if (*interesting_cache) {
495                 struct commit *commit = *interesting_cache;
496                 if (!(commit->object.flags & UNINTERESTING))
497                         return 0;
498         }
499
500         while (list) {
501                 struct commit *commit = list->item;
502                 list = list->next;
503                 if (commit->object.flags & UNINTERESTING)
504                         continue;
505
506                 *interesting_cache = commit;
507                 return 0;
508         }
509         return 1;
510 }
511
512 /*
513  * A definition of "relevant" commit that we can use to simplify limited graphs
514  * by eliminating side branches.
515  *
516  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
517  * in our list), or that is a specified BOTTOM commit. Then after computing
518  * a limited list, during processing we can generally ignore boundary merges
519  * coming from outside the graph, (ie from irrelevant parents), and treat
520  * those merges as if they were single-parent. TREESAME is defined to consider
521  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
522  * we don't care if we were !TREESAME to non-graph parents.
523  *
524  * Treating bottom commits as relevant ensures that a limited graph's
525  * connection to the actual bottom commit is not viewed as a side branch, but
526  * treated as part of the graph. For example:
527  *
528  *   ....Z...A---X---o---o---B
529  *        .     /
530  *         W---Y
531  *
532  * When computing "A..B", the A-X connection is at least as important as
533  * Y-X, despite A being flagged UNINTERESTING.
534  *
535  * And when computing --ancestry-path "A..B", the A-X connection is more
536  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
537  */
538 static inline int relevant_commit(struct commit *commit)
539 {
540         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
541 }
542
543 /*
544  * Return a single relevant commit from a parent list. If we are a TREESAME
545  * commit, and this selects one of our parents, then we can safely simplify to
546  * that parent.
547  */
548 static struct commit *one_relevant_parent(const struct rev_info *revs,
549                                           struct commit_list *orig)
550 {
551         struct commit_list *list = orig;
552         struct commit *relevant = NULL;
553
554         if (!orig)
555                 return NULL;
556
557         /*
558          * For 1-parent commits, or if first-parent-only, then return that
559          * first parent (even if not "relevant" by the above definition).
560          * TREESAME will have been set purely on that parent.
561          */
562         if (revs->first_parent_only || !orig->next)
563                 return orig->item;
564
565         /*
566          * For multi-parent commits, identify a sole relevant parent, if any.
567          * If we have only one relevant parent, then TREESAME will be set purely
568          * with regard to that parent, and we can simplify accordingly.
569          *
570          * If we have more than one relevant parent, or no relevant parents
571          * (and multiple irrelevant ones), then we can't select a parent here
572          * and return NULL.
573          */
574         while (list) {
575                 struct commit *commit = list->item;
576                 list = list->next;
577                 if (relevant_commit(commit)) {
578                         if (relevant)
579                                 return NULL;
580                         relevant = commit;
581                 }
582         }
583         return relevant;
584 }
585
586 /*
587  * The goal is to get REV_TREE_NEW as the result only if the
588  * diff consists of all '+' (and no other changes), REV_TREE_OLD
589  * if the whole diff is removal of old data, and otherwise
590  * REV_TREE_DIFFERENT (of course if the trees are the same we
591  * want REV_TREE_SAME).
592  *
593  * The only time we care about the distinction is when
594  * remove_empty_trees is in effect, in which case we care only about
595  * whether the whole change is REV_TREE_NEW, or if there's another type
596  * of change. Which means we can stop the diff early in either of these
597  * cases:
598  *
599  *   1. We're not using remove_empty_trees at all.
600  *
601  *   2. We saw anything except REV_TREE_NEW.
602  */
603 static int tree_difference = REV_TREE_SAME;
604
605 static void file_add_remove(struct diff_options *options,
606                     int addremove, unsigned mode,
607                     const struct object_id *oid,
608                     int oid_valid,
609                     const char *fullpath, unsigned dirty_submodule)
610 {
611         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
612         struct rev_info *revs = options->change_fn_data;
613
614         tree_difference |= diff;
615         if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
616                 options->flags.has_changes = 1;
617 }
618
619 static void file_change(struct diff_options *options,
620                  unsigned old_mode, unsigned new_mode,
621                  const struct object_id *old_oid,
622                  const struct object_id *new_oid,
623                  int old_oid_valid, int new_oid_valid,
624                  const char *fullpath,
625                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
626 {
627         tree_difference = REV_TREE_DIFFERENT;
628         options->flags.has_changes = 1;
629 }
630
631 static int bloom_filter_atexit_registered;
632 static unsigned int count_bloom_filter_maybe;
633 static unsigned int count_bloom_filter_definitely_not;
634 static unsigned int count_bloom_filter_false_positive;
635 static unsigned int count_bloom_filter_not_present;
636 static unsigned int count_bloom_filter_length_zero;
637
638 static void trace2_bloom_filter_statistics_atexit(void)
639 {
640         struct json_writer jw = JSON_WRITER_INIT;
641
642         jw_object_begin(&jw, 0);
643         jw_object_intmax(&jw, "filter_not_present", count_bloom_filter_not_present);
644         jw_object_intmax(&jw, "zero_length_filter", count_bloom_filter_length_zero);
645         jw_object_intmax(&jw, "maybe", count_bloom_filter_maybe);
646         jw_object_intmax(&jw, "definitely_not", count_bloom_filter_definitely_not);
647         jw_object_intmax(&jw, "false_positive", count_bloom_filter_false_positive);
648         jw_end(&jw);
649
650         trace2_data_json("bloom", the_repository, "statistics", &jw);
651
652         jw_release(&jw);
653 }
654
655 static int forbid_bloom_filters(struct pathspec *spec)
656 {
657         if (spec->has_wildcard)
658                 return 1;
659         if (spec->nr > 1)
660                 return 1;
661         if (spec->magic & ~PATHSPEC_LITERAL)
662                 return 1;
663         if (spec->nr && (spec->items[0].magic & ~PATHSPEC_LITERAL))
664                 return 1;
665
666         return 0;
667 }
668
669 static void prepare_to_use_bloom_filter(struct rev_info *revs)
670 {
671         struct pathspec_item *pi;
672         char *path_alloc = NULL;
673         const char *path;
674         int last_index;
675         int len;
676
677         if (!revs->commits)
678                 return;
679
680         if (forbid_bloom_filters(&revs->prune_data))
681                 return;
682
683         repo_parse_commit(revs->repo, revs->commits->item);
684
685         if (!revs->repo->objects->commit_graph)
686                 return;
687
688         revs->bloom_filter_settings = revs->repo->objects->commit_graph->bloom_filter_settings;
689         if (!revs->bloom_filter_settings)
690                 return;
691
692         if (!revs->pruning.pathspec.nr)
693                 return;
694
695         pi = &revs->pruning.pathspec.items[0];
696         last_index = pi->len - 1;
697
698         /* remove single trailing slash from path, if needed */
699         if (pi->match[last_index] == '/') {
700             path_alloc = xstrdup(pi->match);
701             path_alloc[last_index] = '\0';
702             path = path_alloc;
703         } else
704             path = pi->match;
705
706         len = strlen(path);
707
708         revs->bloom_key = xmalloc(sizeof(struct bloom_key));
709         fill_bloom_key(path, len, revs->bloom_key, revs->bloom_filter_settings);
710
711         if (trace2_is_enabled() && !bloom_filter_atexit_registered) {
712                 atexit(trace2_bloom_filter_statistics_atexit);
713                 bloom_filter_atexit_registered = 1;
714         }
715
716         free(path_alloc);
717 }
718
719 static int check_maybe_different_in_bloom_filter(struct rev_info *revs,
720                                                  struct commit *commit)
721 {
722         struct bloom_filter *filter;
723         int result;
724
725         if (!revs->repo->objects->commit_graph)
726                 return -1;
727
728         if (commit->generation == GENERATION_NUMBER_INFINITY)
729                 return -1;
730
731         filter = get_bloom_filter(revs->repo, commit, 0);
732
733         if (!filter) {
734                 count_bloom_filter_not_present++;
735                 return -1;
736         }
737
738         if (!filter->len) {
739                 count_bloom_filter_length_zero++;
740                 return -1;
741         }
742
743         result = bloom_filter_contains(filter,
744                                        revs->bloom_key,
745                                        revs->bloom_filter_settings);
746
747         if (result)
748                 count_bloom_filter_maybe++;
749         else
750                 count_bloom_filter_definitely_not++;
751
752         return result;
753 }
754
755 static int rev_compare_tree(struct rev_info *revs,
756                             struct commit *parent, struct commit *commit, int nth_parent)
757 {
758         struct tree *t1 = get_commit_tree(parent);
759         struct tree *t2 = get_commit_tree(commit);
760         int bloom_ret = 1;
761
762         if (!t1)
763                 return REV_TREE_NEW;
764         if (!t2)
765                 return REV_TREE_OLD;
766
767         if (revs->simplify_by_decoration) {
768                 /*
769                  * If we are simplifying by decoration, then the commit
770                  * is worth showing if it has a tag pointing at it.
771                  */
772                 if (get_name_decoration(&commit->object))
773                         return REV_TREE_DIFFERENT;
774                 /*
775                  * A commit that is not pointed by a tag is uninteresting
776                  * if we are not limited by path.  This means that you will
777                  * see the usual "commits that touch the paths" plus any
778                  * tagged commit by specifying both --simplify-by-decoration
779                  * and pathspec.
780                  */
781                 if (!revs->prune_data.nr)
782                         return REV_TREE_SAME;
783         }
784
785         if (revs->bloom_key && !nth_parent) {
786                 bloom_ret = check_maybe_different_in_bloom_filter(revs, commit);
787
788                 if (bloom_ret == 0)
789                         return REV_TREE_SAME;
790         }
791
792         tree_difference = REV_TREE_SAME;
793         revs->pruning.flags.has_changes = 0;
794         if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
795                            &revs->pruning) < 0)
796                 return REV_TREE_DIFFERENT;
797
798         if (!nth_parent)
799                 if (bloom_ret == 1 && tree_difference == REV_TREE_SAME)
800                         count_bloom_filter_false_positive++;
801
802         return tree_difference;
803 }
804
805 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
806 {
807         int retval;
808         struct tree *t1 = get_commit_tree(commit);
809
810         if (!t1)
811                 return 0;
812
813         tree_difference = REV_TREE_SAME;
814         revs->pruning.flags.has_changes = 0;
815         retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
816
817         return retval >= 0 && (tree_difference == REV_TREE_SAME);
818 }
819
820 struct treesame_state {
821         unsigned int nparents;
822         unsigned char treesame[FLEX_ARRAY];
823 };
824
825 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
826 {
827         unsigned n = commit_list_count(commit->parents);
828         struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
829         st->nparents = n;
830         add_decoration(&revs->treesame, &commit->object, st);
831         return st;
832 }
833
834 /*
835  * Must be called immediately after removing the nth_parent from a commit's
836  * parent list, if we are maintaining the per-parent treesame[] decoration.
837  * This does not recalculate the master TREESAME flag - update_treesame()
838  * should be called to update it after a sequence of treesame[] modifications
839  * that may have affected it.
840  */
841 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
842 {
843         struct treesame_state *st;
844         int old_same;
845
846         if (!commit->parents) {
847                 /*
848                  * Have just removed the only parent from a non-merge.
849                  * Different handling, as we lack decoration.
850                  */
851                 if (nth_parent != 0)
852                         die("compact_treesame %u", nth_parent);
853                 old_same = !!(commit->object.flags & TREESAME);
854                 if (rev_same_tree_as_empty(revs, commit))
855                         commit->object.flags |= TREESAME;
856                 else
857                         commit->object.flags &= ~TREESAME;
858                 return old_same;
859         }
860
861         st = lookup_decoration(&revs->treesame, &commit->object);
862         if (!st || nth_parent >= st->nparents)
863                 die("compact_treesame %u", nth_parent);
864
865         old_same = st->treesame[nth_parent];
866         memmove(st->treesame + nth_parent,
867                 st->treesame + nth_parent + 1,
868                 st->nparents - nth_parent - 1);
869
870         /*
871          * If we've just become a non-merge commit, update TREESAME
872          * immediately, and remove the no-longer-needed decoration.
873          * If still a merge, defer update until update_treesame().
874          */
875         if (--st->nparents == 1) {
876                 if (commit->parents->next)
877                         die("compact_treesame parents mismatch");
878                 if (st->treesame[0] && revs->dense)
879                         commit->object.flags |= TREESAME;
880                 else
881                         commit->object.flags &= ~TREESAME;
882                 free(add_decoration(&revs->treesame, &commit->object, NULL));
883         }
884
885         return old_same;
886 }
887
888 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
889 {
890         if (commit->parents && commit->parents->next) {
891                 unsigned n;
892                 struct treesame_state *st;
893                 struct commit_list *p;
894                 unsigned relevant_parents;
895                 unsigned relevant_change, irrelevant_change;
896
897                 st = lookup_decoration(&revs->treesame, &commit->object);
898                 if (!st)
899                         die("update_treesame %s", oid_to_hex(&commit->object.oid));
900                 relevant_parents = 0;
901                 relevant_change = irrelevant_change = 0;
902                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
903                         if (relevant_commit(p->item)) {
904                                 relevant_change |= !st->treesame[n];
905                                 relevant_parents++;
906                         } else
907                                 irrelevant_change |= !st->treesame[n];
908                 }
909                 if (relevant_parents ? relevant_change : irrelevant_change)
910                         commit->object.flags &= ~TREESAME;
911                 else
912                         commit->object.flags |= TREESAME;
913         }
914
915         return commit->object.flags & TREESAME;
916 }
917
918 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
919 {
920         /*
921          * TREESAME is irrelevant unless prune && dense;
922          * if simplify_history is set, we can't have a mixture of TREESAME and
923          *    !TREESAME INTERESTING parents (and we don't have treesame[]
924          *    decoration anyway);
925          * if first_parent_only is set, then the TREESAME flag is locked
926          *    against the first parent (and again we lack treesame[] decoration).
927          */
928         return revs->prune && revs->dense &&
929                !revs->simplify_history &&
930                !revs->first_parent_only;
931 }
932
933 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
934 {
935         struct commit_list **pp, *parent;
936         struct treesame_state *ts = NULL;
937         int relevant_change = 0, irrelevant_change = 0;
938         int relevant_parents, nth_parent;
939
940         /*
941          * If we don't do pruning, everything is interesting
942          */
943         if (!revs->prune)
944                 return;
945
946         if (!get_commit_tree(commit))
947                 return;
948
949         if (!commit->parents) {
950                 if (rev_same_tree_as_empty(revs, commit))
951                         commit->object.flags |= TREESAME;
952                 return;
953         }
954
955         /*
956          * Normal non-merge commit? If we don't want to make the
957          * history dense, we consider it always to be a change..
958          */
959         if (!revs->dense && !commit->parents->next)
960                 return;
961
962         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
963              (parent = *pp) != NULL;
964              pp = &parent->next, nth_parent++) {
965                 struct commit *p = parent->item;
966                 if (relevant_commit(p))
967                         relevant_parents++;
968
969                 if (nth_parent == 1) {
970                         /*
971                          * This our second loop iteration - so we now know
972                          * we're dealing with a merge.
973                          *
974                          * Do not compare with later parents when we care only about
975                          * the first parent chain, in order to avoid derailing the
976                          * traversal to follow a side branch that brought everything
977                          * in the path we are limited to by the pathspec.
978                          */
979                         if (revs->first_parent_only)
980                                 break;
981                         /*
982                          * If this will remain a potentially-simplifiable
983                          * merge, remember per-parent treesame if needed.
984                          * Initialise the array with the comparison from our
985                          * first iteration.
986                          */
987                         if (revs->treesame.name &&
988                             !revs->simplify_history &&
989                             !(commit->object.flags & UNINTERESTING)) {
990                                 ts = initialise_treesame(revs, commit);
991                                 if (!(irrelevant_change || relevant_change))
992                                         ts->treesame[0] = 1;
993                         }
994                 }
995                 if (parse_commit(p) < 0)
996                         die("cannot simplify commit %s (because of %s)",
997                             oid_to_hex(&commit->object.oid),
998                             oid_to_hex(&p->object.oid));
999                 switch (rev_compare_tree(revs, p, commit, nth_parent)) {
1000                 case REV_TREE_SAME:
1001                         if (!revs->simplify_history || !relevant_commit(p)) {
1002                                 /* Even if a merge with an uninteresting
1003                                  * side branch brought the entire change
1004                                  * we are interested in, we do not want
1005                                  * to lose the other branches of this
1006                                  * merge, so we just keep going.
1007                                  */
1008                                 if (ts)
1009                                         ts->treesame[nth_parent] = 1;
1010                                 continue;
1011                         }
1012                         parent->next = NULL;
1013                         commit->parents = parent;
1014
1015                         /*
1016                          * A merge commit is a "diversion" if it is not
1017                          * TREESAME to its first parent but is TREESAME
1018                          * to a later parent. In the simplified history,
1019                          * we "divert" the history walk to the later
1020                          * parent. These commits are shown when "show_pulls"
1021                          * is enabled, so do not mark the object as
1022                          * TREESAME here.
1023                          */
1024                         if (!revs->show_pulls || !nth_parent)
1025                                 commit->object.flags |= TREESAME;
1026
1027                         return;
1028
1029                 case REV_TREE_NEW:
1030                         if (revs->remove_empty_trees &&
1031                             rev_same_tree_as_empty(revs, p)) {
1032                                 /* We are adding all the specified
1033                                  * paths from this parent, so the
1034                                  * history beyond this parent is not
1035                                  * interesting.  Remove its parents
1036                                  * (they are grandparents for us).
1037                                  * IOW, we pretend this parent is a
1038                                  * "root" commit.
1039                                  */
1040                                 if (parse_commit(p) < 0)
1041                                         die("cannot simplify commit %s (invalid %s)",
1042                                             oid_to_hex(&commit->object.oid),
1043                                             oid_to_hex(&p->object.oid));
1044                                 p->parents = NULL;
1045                         }
1046                 /* fallthrough */
1047                 case REV_TREE_OLD:
1048                 case REV_TREE_DIFFERENT:
1049                         if (relevant_commit(p))
1050                                 relevant_change = 1;
1051                         else
1052                                 irrelevant_change = 1;
1053
1054                         if (!nth_parent)
1055                                 commit->object.flags |= PULL_MERGE;
1056
1057                         continue;
1058                 }
1059                 die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
1060         }
1061
1062         /*
1063          * TREESAME is straightforward for single-parent commits. For merge
1064          * commits, it is most useful to define it so that "irrelevant"
1065          * parents cannot make us !TREESAME - if we have any relevant
1066          * parents, then we only consider TREESAMEness with respect to them,
1067          * allowing irrelevant merges from uninteresting branches to be
1068          * simplified away. Only if we have only irrelevant parents do we
1069          * base TREESAME on them. Note that this logic is replicated in
1070          * update_treesame, which should be kept in sync.
1071          */
1072         if (relevant_parents ? !relevant_change : !irrelevant_change)
1073                 commit->object.flags |= TREESAME;
1074 }
1075
1076 static int process_parents(struct rev_info *revs, struct commit *commit,
1077                            struct commit_list **list, struct prio_queue *queue)
1078 {
1079         struct commit_list *parent = commit->parents;
1080         unsigned left_flag;
1081
1082         if (commit->object.flags & ADDED)
1083                 return 0;
1084         commit->object.flags |= ADDED;
1085
1086         if (revs->include_check &&
1087             !revs->include_check(commit, revs->include_check_data))
1088                 return 0;
1089
1090         /*
1091          * If the commit is uninteresting, don't try to
1092          * prune parents - we want the maximal uninteresting
1093          * set.
1094          *
1095          * Normally we haven't parsed the parent
1096          * yet, so we won't have a parent of a parent
1097          * here. However, it may turn out that we've
1098          * reached this commit some other way (where it
1099          * wasn't uninteresting), in which case we need
1100          * to mark its parents recursively too..
1101          */
1102         if (commit->object.flags & UNINTERESTING) {
1103                 while (parent) {
1104                         struct commit *p = parent->item;
1105                         parent = parent->next;
1106                         if (p)
1107                                 p->object.flags |= UNINTERESTING;
1108                         if (parse_commit_gently(p, 1) < 0)
1109                                 continue;
1110                         if (p->parents)
1111                                 mark_parents_uninteresting(p);
1112                         if (p->object.flags & SEEN)
1113                                 continue;
1114                         p->object.flags |= SEEN;
1115                         if (list)
1116                                 commit_list_insert_by_date(p, list);
1117                         if (queue)
1118                                 prio_queue_put(queue, p);
1119                 }
1120                 return 0;
1121         }
1122
1123         /*
1124          * Ok, the commit wasn't uninteresting. Try to
1125          * simplify the commit history and find the parent
1126          * that has no differences in the path set if one exists.
1127          */
1128         try_to_simplify_commit(revs, commit);
1129
1130         if (revs->no_walk)
1131                 return 0;
1132
1133         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
1134
1135         for (parent = commit->parents; parent; parent = parent->next) {
1136                 struct commit *p = parent->item;
1137                 int gently = revs->ignore_missing_links ||
1138                              revs->exclude_promisor_objects;
1139                 if (parse_commit_gently(p, gently) < 0) {
1140                         if (revs->exclude_promisor_objects &&
1141                             is_promisor_object(&p->object.oid)) {
1142                                 if (revs->first_parent_only)
1143                                         break;
1144                                 continue;
1145                         }
1146                         return -1;
1147                 }
1148                 if (revs->sources) {
1149                         char **slot = revision_sources_at(revs->sources, p);
1150
1151                         if (!*slot)
1152                                 *slot = *revision_sources_at(revs->sources, commit);
1153                 }
1154                 p->object.flags |= left_flag;
1155                 if (!(p->object.flags & SEEN)) {
1156                         p->object.flags |= SEEN;
1157                         if (list)
1158                                 commit_list_insert_by_date(p, list);
1159                         if (queue)
1160                                 prio_queue_put(queue, p);
1161                 }
1162                 if (revs->first_parent_only)
1163                         break;
1164         }
1165         return 0;
1166 }
1167
1168 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
1169 {
1170         struct commit_list *p;
1171         int left_count = 0, right_count = 0;
1172         int left_first;
1173         struct patch_ids ids;
1174         unsigned cherry_flag;
1175
1176         /* First count the commits on the left and on the right */
1177         for (p = list; p; p = p->next) {
1178                 struct commit *commit = p->item;
1179                 unsigned flags = commit->object.flags;
1180                 if (flags & BOUNDARY)
1181                         ;
1182                 else if (flags & SYMMETRIC_LEFT)
1183                         left_count++;
1184                 else
1185                         right_count++;
1186         }
1187
1188         if (!left_count || !right_count)
1189                 return;
1190
1191         left_first = left_count < right_count;
1192         init_patch_ids(revs->repo, &ids);
1193         ids.diffopts.pathspec = revs->diffopt.pathspec;
1194
1195         /* Compute patch-ids for one side */
1196         for (p = list; p; p = p->next) {
1197                 struct commit *commit = p->item;
1198                 unsigned flags = commit->object.flags;
1199
1200                 if (flags & BOUNDARY)
1201                         continue;
1202                 /*
1203                  * If we have fewer left, left_first is set and we omit
1204                  * commits on the right branch in this loop.  If we have
1205                  * fewer right, we skip the left ones.
1206                  */
1207                 if (left_first != !!(flags & SYMMETRIC_LEFT))
1208                         continue;
1209                 add_commit_patch_id(commit, &ids);
1210         }
1211
1212         /* either cherry_mark or cherry_pick are true */
1213         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
1214
1215         /* Check the other side */
1216         for (p = list; p; p = p->next) {
1217                 struct commit *commit = p->item;
1218                 struct patch_id *id;
1219                 unsigned flags = commit->object.flags;
1220
1221                 if (flags & BOUNDARY)
1222                         continue;
1223                 /*
1224                  * If we have fewer left, left_first is set and we omit
1225                  * commits on the left branch in this loop.
1226                  */
1227                 if (left_first == !!(flags & SYMMETRIC_LEFT))
1228                         continue;
1229
1230                 /*
1231                  * Have we seen the same patch id?
1232                  */
1233                 id = has_commit_patch_id(commit, &ids);
1234                 if (!id)
1235                         continue;
1236
1237                 commit->object.flags |= cherry_flag;
1238                 id->commit->object.flags |= cherry_flag;
1239         }
1240
1241         free_patch_ids(&ids);
1242 }
1243
1244 /* How many extra uninteresting commits we want to see.. */
1245 #define SLOP 5
1246
1247 static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
1248                              struct commit **interesting_cache)
1249 {
1250         /*
1251          * No source list at all? We're definitely done..
1252          */
1253         if (!src)
1254                 return 0;
1255
1256         /*
1257          * Does the destination list contain entries with a date
1258          * before the source list? Definitely _not_ done.
1259          */
1260         if (date <= src->item->date)
1261                 return SLOP;
1262
1263         /*
1264          * Does the source list still have interesting commits in
1265          * it? Definitely not done..
1266          */
1267         if (!everybody_uninteresting(src, interesting_cache))
1268                 return SLOP;
1269
1270         /* Ok, we're closing in.. */
1271         return slop-1;
1272 }
1273
1274 /*
1275  * "rev-list --ancestry-path A..B" computes commits that are ancestors
1276  * of B but not ancestors of A but further limits the result to those
1277  * that are descendants of A.  This takes the list of bottom commits and
1278  * the result of "A..B" without --ancestry-path, and limits the latter
1279  * further to the ones that can reach one of the commits in "bottom".
1280  */
1281 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
1282 {
1283         struct commit_list *p;
1284         struct commit_list *rlist = NULL;
1285         int made_progress;
1286
1287         /*
1288          * Reverse the list so that it will be likely that we would
1289          * process parents before children.
1290          */
1291         for (p = list; p; p = p->next)
1292                 commit_list_insert(p->item, &rlist);
1293
1294         for (p = bottom; p; p = p->next)
1295                 p->item->object.flags |= TMP_MARK;
1296
1297         /*
1298          * Mark the ones that can reach bottom commits in "list",
1299          * in a bottom-up fashion.
1300          */
1301         do {
1302                 made_progress = 0;
1303                 for (p = rlist; p; p = p->next) {
1304                         struct commit *c = p->item;
1305                         struct commit_list *parents;
1306                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
1307                                 continue;
1308                         for (parents = c->parents;
1309                              parents;
1310                              parents = parents->next) {
1311                                 if (!(parents->item->object.flags & TMP_MARK))
1312                                         continue;
1313                                 c->object.flags |= TMP_MARK;
1314                                 made_progress = 1;
1315                                 break;
1316                         }
1317                 }
1318         } while (made_progress);
1319
1320         /*
1321          * NEEDSWORK: decide if we want to remove parents that are
1322          * not marked with TMP_MARK from commit->parents for commits
1323          * in the resulting list.  We may not want to do that, though.
1324          */
1325
1326         /*
1327          * The ones that are not marked with TMP_MARK are uninteresting
1328          */
1329         for (p = list; p; p = p->next) {
1330                 struct commit *c = p->item;
1331                 if (c->object.flags & TMP_MARK)
1332                         continue;
1333                 c->object.flags |= UNINTERESTING;
1334         }
1335
1336         /* We are done with the TMP_MARK */
1337         for (p = list; p; p = p->next)
1338                 p->item->object.flags &= ~TMP_MARK;
1339         for (p = bottom; p; p = p->next)
1340                 p->item->object.flags &= ~TMP_MARK;
1341         free_commit_list(rlist);
1342 }
1343
1344 /*
1345  * Before walking the history, keep the set of "negative" refs the
1346  * caller has asked to exclude.
1347  *
1348  * This is used to compute "rev-list --ancestry-path A..B", as we need
1349  * to filter the result of "A..B" further to the ones that can actually
1350  * reach A.
1351  */
1352 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1353 {
1354         struct commit_list *elem, *bottom = NULL;
1355         for (elem = list; elem; elem = elem->next)
1356                 if (elem->item->object.flags & BOTTOM)
1357                         commit_list_insert(elem->item, &bottom);
1358         return bottom;
1359 }
1360
1361 /* Assumes either left_only or right_only is set */
1362 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1363 {
1364         struct commit_list *p;
1365
1366         for (p = list; p; p = p->next) {
1367                 struct commit *commit = p->item;
1368
1369                 if (revs->right_only) {
1370                         if (commit->object.flags & SYMMETRIC_LEFT)
1371                                 commit->object.flags |= SHOWN;
1372                 } else  /* revs->left_only is set */
1373                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1374                                 commit->object.flags |= SHOWN;
1375         }
1376 }
1377
1378 static int limit_list(struct rev_info *revs)
1379 {
1380         int slop = SLOP;
1381         timestamp_t date = TIME_MAX;
1382         struct commit_list *list = revs->commits;
1383         struct commit_list *newlist = NULL;
1384         struct commit_list **p = &newlist;
1385         struct commit_list *bottom = NULL;
1386         struct commit *interesting_cache = NULL;
1387
1388         if (revs->ancestry_path) {
1389                 bottom = collect_bottom_commits(list);
1390                 if (!bottom)
1391                         die("--ancestry-path given but there are no bottom commits");
1392         }
1393
1394         while (list) {
1395                 struct commit *commit = pop_commit(&list);
1396                 struct object *obj = &commit->object;
1397                 show_early_output_fn_t show;
1398
1399                 if (commit == interesting_cache)
1400                         interesting_cache = NULL;
1401
1402                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1403                         obj->flags |= UNINTERESTING;
1404                 if (process_parents(revs, commit, &list, NULL) < 0)
1405                         return -1;
1406                 if (obj->flags & UNINTERESTING) {
1407                         mark_parents_uninteresting(commit);
1408                         slop = still_interesting(list, date, slop, &interesting_cache);
1409                         if (slop)
1410                                 continue;
1411                         break;
1412                 }
1413                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1414                         continue;
1415                 date = commit->date;
1416                 p = &commit_list_insert(commit, p)->next;
1417
1418                 show = show_early_output;
1419                 if (!show)
1420                         continue;
1421
1422                 show(revs, newlist);
1423                 show_early_output = NULL;
1424         }
1425         if (revs->cherry_pick || revs->cherry_mark)
1426                 cherry_pick_list(newlist, revs);
1427
1428         if (revs->left_only || revs->right_only)
1429                 limit_left_right(newlist, revs);
1430
1431         if (bottom) {
1432                 limit_to_ancestry(bottom, newlist);
1433                 free_commit_list(bottom);
1434         }
1435
1436         /*
1437          * Check if any commits have become TREESAME by some of their parents
1438          * becoming UNINTERESTING.
1439          */
1440         if (limiting_can_increase_treesame(revs))
1441                 for (list = newlist; list; list = list->next) {
1442                         struct commit *c = list->item;
1443                         if (c->object.flags & (UNINTERESTING | TREESAME))
1444                                 continue;
1445                         update_treesame(revs, c);
1446                 }
1447
1448         revs->commits = newlist;
1449         return 0;
1450 }
1451
1452 /*
1453  * Add an entry to refs->cmdline with the specified information.
1454  * *name is copied.
1455  */
1456 static void add_rev_cmdline(struct rev_info *revs,
1457                             struct object *item,
1458                             const char *name,
1459                             int whence,
1460                             unsigned flags)
1461 {
1462         struct rev_cmdline_info *info = &revs->cmdline;
1463         unsigned int nr = info->nr;
1464
1465         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1466         info->rev[nr].item = item;
1467         info->rev[nr].name = xstrdup(name);
1468         info->rev[nr].whence = whence;
1469         info->rev[nr].flags = flags;
1470         info->nr++;
1471 }
1472
1473 static void add_rev_cmdline_list(struct rev_info *revs,
1474                                  struct commit_list *commit_list,
1475                                  int whence,
1476                                  unsigned flags)
1477 {
1478         while (commit_list) {
1479                 struct object *object = &commit_list->item->object;
1480                 add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1481                                 whence, flags);
1482                 commit_list = commit_list->next;
1483         }
1484 }
1485
1486 struct all_refs_cb {
1487         int all_flags;
1488         int warned_bad_reflog;
1489         struct rev_info *all_revs;
1490         const char *name_for_errormsg;
1491         struct worktree *wt;
1492 };
1493
1494 int ref_excluded(struct string_list *ref_excludes, const char *path)
1495 {
1496         struct string_list_item *item;
1497
1498         if (!ref_excludes)
1499                 return 0;
1500         for_each_string_list_item(item, ref_excludes) {
1501                 if (!wildmatch(item->string, path, 0))
1502                         return 1;
1503         }
1504         return 0;
1505 }
1506
1507 static int handle_one_ref(const char *path, const struct object_id *oid,
1508                           int flag, void *cb_data)
1509 {
1510         struct all_refs_cb *cb = cb_data;
1511         struct object *object;
1512
1513         if (ref_excluded(cb->all_revs->ref_excludes, path))
1514             return 0;
1515
1516         object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1517         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1518         add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1519         return 0;
1520 }
1521
1522 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1523         unsigned flags)
1524 {
1525         cb->all_revs = revs;
1526         cb->all_flags = flags;
1527         revs->rev_input_given = 1;
1528         cb->wt = NULL;
1529 }
1530
1531 void clear_ref_exclusion(struct string_list **ref_excludes_p)
1532 {
1533         if (*ref_excludes_p) {
1534                 string_list_clear(*ref_excludes_p, 0);
1535                 free(*ref_excludes_p);
1536         }
1537         *ref_excludes_p = NULL;
1538 }
1539
1540 void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1541 {
1542         if (!*ref_excludes_p) {
1543                 *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1544                 (*ref_excludes_p)->strdup_strings = 1;
1545         }
1546         string_list_append(*ref_excludes_p, exclude);
1547 }
1548
1549 static void handle_refs(struct ref_store *refs,
1550                         struct rev_info *revs, unsigned flags,
1551                         int (*for_each)(struct ref_store *, each_ref_fn, void *))
1552 {
1553         struct all_refs_cb cb;
1554
1555         if (!refs) {
1556                 /* this could happen with uninitialized submodules */
1557                 return;
1558         }
1559
1560         init_all_refs_cb(&cb, revs, flags);
1561         for_each(refs, handle_one_ref, &cb);
1562 }
1563
1564 static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1565 {
1566         struct all_refs_cb *cb = cb_data;
1567         if (!is_null_oid(oid)) {
1568                 struct object *o = parse_object(cb->all_revs->repo, oid);
1569                 if (o) {
1570                         o->flags |= cb->all_flags;
1571                         /* ??? CMDLINEFLAGS ??? */
1572                         add_pending_object(cb->all_revs, o, "");
1573                 }
1574                 else if (!cb->warned_bad_reflog) {
1575                         warning("reflog of '%s' references pruned commits",
1576                                 cb->name_for_errormsg);
1577                         cb->warned_bad_reflog = 1;
1578                 }
1579         }
1580 }
1581
1582 static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1583                 const char *email, timestamp_t timestamp, int tz,
1584                 const char *message, void *cb_data)
1585 {
1586         handle_one_reflog_commit(ooid, cb_data);
1587         handle_one_reflog_commit(noid, cb_data);
1588         return 0;
1589 }
1590
1591 static int handle_one_reflog(const char *refname_in_wt,
1592                              const struct object_id *oid,
1593                              int flag, void *cb_data)
1594 {
1595         struct all_refs_cb *cb = cb_data;
1596         struct strbuf refname = STRBUF_INIT;
1597
1598         cb->warned_bad_reflog = 0;
1599         strbuf_worktree_ref(cb->wt, &refname, refname_in_wt);
1600         cb->name_for_errormsg = refname.buf;
1601         refs_for_each_reflog_ent(get_main_ref_store(the_repository),
1602                                  refname.buf,
1603                                  handle_one_reflog_ent, cb_data);
1604         strbuf_release(&refname);
1605         return 0;
1606 }
1607
1608 static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
1609 {
1610         struct worktree **worktrees, **p;
1611
1612         worktrees = get_worktrees(0);
1613         for (p = worktrees; *p; p++) {
1614                 struct worktree *wt = *p;
1615
1616                 if (wt->is_current)
1617                         continue;
1618
1619                 cb->wt = wt;
1620                 refs_for_each_reflog(get_worktree_ref_store(wt),
1621                                      handle_one_reflog,
1622                                      cb);
1623         }
1624         free_worktrees(worktrees);
1625 }
1626
1627 void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1628 {
1629         struct all_refs_cb cb;
1630
1631         cb.all_revs = revs;
1632         cb.all_flags = flags;
1633         cb.wt = NULL;
1634         for_each_reflog(handle_one_reflog, &cb);
1635
1636         if (!revs->single_worktree)
1637                 add_other_reflogs_to_pending(&cb);
1638 }
1639
1640 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1641                            struct strbuf *path, unsigned int flags)
1642 {
1643         size_t baselen = path->len;
1644         int i;
1645
1646         if (it->entry_count >= 0) {
1647                 struct tree *tree = lookup_tree(revs->repo, &it->oid);
1648                 tree->object.flags |= flags;
1649                 add_pending_object_with_path(revs, &tree->object, "",
1650                                              040000, path->buf);
1651         }
1652
1653         for (i = 0; i < it->subtree_nr; i++) {
1654                 struct cache_tree_sub *sub = it->down[i];
1655                 strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1656                 add_cache_tree(sub->cache_tree, revs, path, flags);
1657                 strbuf_setlen(path, baselen);
1658         }
1659
1660 }
1661
1662 static void do_add_index_objects_to_pending(struct rev_info *revs,
1663                                             struct index_state *istate,
1664                                             unsigned int flags)
1665 {
1666         int i;
1667
1668         for (i = 0; i < istate->cache_nr; i++) {
1669                 struct cache_entry *ce = istate->cache[i];
1670                 struct blob *blob;
1671
1672                 if (S_ISGITLINK(ce->ce_mode))
1673                         continue;
1674
1675                 blob = lookup_blob(revs->repo, &ce->oid);
1676                 if (!blob)
1677                         die("unable to add index blob to traversal");
1678                 blob->object.flags |= flags;
1679                 add_pending_object_with_path(revs, &blob->object, "",
1680                                              ce->ce_mode, ce->name);
1681         }
1682
1683         if (istate->cache_tree) {
1684                 struct strbuf path = STRBUF_INIT;
1685                 add_cache_tree(istate->cache_tree, revs, &path, flags);
1686                 strbuf_release(&path);
1687         }
1688 }
1689
1690 void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
1691 {
1692         struct worktree **worktrees, **p;
1693
1694         repo_read_index(revs->repo);
1695         do_add_index_objects_to_pending(revs, revs->repo->index, flags);
1696
1697         if (revs->single_worktree)
1698                 return;
1699
1700         worktrees = get_worktrees(0);
1701         for (p = worktrees; *p; p++) {
1702                 struct worktree *wt = *p;
1703                 struct index_state istate = { NULL };
1704
1705                 if (wt->is_current)
1706                         continue; /* current index already taken care of */
1707
1708                 if (read_index_from(&istate,
1709                                     worktree_git_path(wt, "index"),
1710                                     get_worktree_git_dir(wt)) > 0)
1711                         do_add_index_objects_to_pending(revs, &istate, flags);
1712                 discard_index(&istate);
1713         }
1714         free_worktrees(worktrees);
1715 }
1716
1717 struct add_alternate_refs_data {
1718         struct rev_info *revs;
1719         unsigned int flags;
1720 };
1721
1722 static void add_one_alternate_ref(const struct object_id *oid,
1723                                   void *vdata)
1724 {
1725         const char *name = ".alternate";
1726         struct add_alternate_refs_data *data = vdata;
1727         struct object *obj;
1728
1729         obj = get_reference(data->revs, name, oid, data->flags);
1730         add_rev_cmdline(data->revs, obj, name, REV_CMD_REV, data->flags);
1731         add_pending_object(data->revs, obj, name);
1732 }
1733
1734 static void add_alternate_refs_to_pending(struct rev_info *revs,
1735                                           unsigned int flags)
1736 {
1737         struct add_alternate_refs_data data;
1738         data.revs = revs;
1739         data.flags = flags;
1740         for_each_alternate_ref(add_one_alternate_ref, &data);
1741 }
1742
1743 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1744                             int exclude_parent)
1745 {
1746         struct object_id oid;
1747         struct object *it;
1748         struct commit *commit;
1749         struct commit_list *parents;
1750         int parent_number;
1751         const char *arg = arg_;
1752
1753         if (*arg == '^') {
1754                 flags ^= UNINTERESTING | BOTTOM;
1755                 arg++;
1756         }
1757         if (get_oid_committish(arg, &oid))
1758                 return 0;
1759         while (1) {
1760                 it = get_reference(revs, arg, &oid, 0);
1761                 if (!it && revs->ignore_missing)
1762                         return 0;
1763                 if (it->type != OBJ_TAG)
1764                         break;
1765                 if (!((struct tag*)it)->tagged)
1766                         return 0;
1767                 oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1768         }
1769         if (it->type != OBJ_COMMIT)
1770                 return 0;
1771         commit = (struct commit *)it;
1772         if (exclude_parent &&
1773             exclude_parent > commit_list_count(commit->parents))
1774                 return 0;
1775         for (parents = commit->parents, parent_number = 1;
1776              parents;
1777              parents = parents->next, parent_number++) {
1778                 if (exclude_parent && parent_number != exclude_parent)
1779                         continue;
1780
1781                 it = &parents->item->object;
1782                 it->flags |= flags;
1783                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1784                 add_pending_object(revs, it, arg);
1785         }
1786         return 1;
1787 }
1788
1789 void repo_init_revisions(struct repository *r,
1790                          struct rev_info *revs,
1791                          const char *prefix)
1792 {
1793         memset(revs, 0, sizeof(*revs));
1794
1795         revs->repo = r;
1796         revs->abbrev = DEFAULT_ABBREV;
1797         revs->ignore_merges = 1;
1798         revs->simplify_history = 1;
1799         revs->pruning.repo = r;
1800         revs->pruning.flags.recursive = 1;
1801         revs->pruning.flags.quick = 1;
1802         revs->pruning.add_remove = file_add_remove;
1803         revs->pruning.change = file_change;
1804         revs->pruning.change_fn_data = revs;
1805         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1806         revs->dense = 1;
1807         revs->prefix = prefix;
1808         revs->max_age = -1;
1809         revs->min_age = -1;
1810         revs->skip_count = -1;
1811         revs->max_count = -1;
1812         revs->max_parents = -1;
1813         revs->expand_tabs_in_log = -1;
1814
1815         revs->commit_format = CMIT_FMT_DEFAULT;
1816         revs->expand_tabs_in_log_default = 8;
1817
1818         init_grep_defaults(revs->repo);
1819         grep_init(&revs->grep_filter, revs->repo, prefix);
1820         revs->grep_filter.status_only = 1;
1821
1822         repo_diff_setup(revs->repo, &revs->diffopt);
1823         if (prefix && !revs->diffopt.prefix) {
1824                 revs->diffopt.prefix = prefix;
1825                 revs->diffopt.prefix_length = strlen(prefix);
1826         }
1827
1828         init_display_notes(&revs->notes_opt);
1829 }
1830
1831 static void add_pending_commit_list(struct rev_info *revs,
1832                                     struct commit_list *commit_list,
1833                                     unsigned int flags)
1834 {
1835         while (commit_list) {
1836                 struct object *object = &commit_list->item->object;
1837                 object->flags |= flags;
1838                 add_pending_object(revs, object, oid_to_hex(&object->oid));
1839                 commit_list = commit_list->next;
1840         }
1841 }
1842
1843 static void prepare_show_merge(struct rev_info *revs)
1844 {
1845         struct commit_list *bases;
1846         struct commit *head, *other;
1847         struct object_id oid;
1848         const char **prune = NULL;
1849         int i, prune_num = 1; /* counting terminating NULL */
1850         struct index_state *istate = revs->repo->index;
1851
1852         if (get_oid("HEAD", &oid))
1853                 die("--merge without HEAD?");
1854         head = lookup_commit_or_die(&oid, "HEAD");
1855         if (get_oid("MERGE_HEAD", &oid))
1856                 die("--merge without MERGE_HEAD?");
1857         other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1858         add_pending_object(revs, &head->object, "HEAD");
1859         add_pending_object(revs, &other->object, "MERGE_HEAD");
1860         bases = get_merge_bases(head, other);
1861         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1862         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1863         free_commit_list(bases);
1864         head->object.flags |= SYMMETRIC_LEFT;
1865
1866         if (!istate->cache_nr)
1867                 repo_read_index(revs->repo);
1868         for (i = 0; i < istate->cache_nr; i++) {
1869                 const struct cache_entry *ce = istate->cache[i];
1870                 if (!ce_stage(ce))
1871                         continue;
1872                 if (ce_path_match(istate, ce, &revs->prune_data, NULL)) {
1873                         prune_num++;
1874                         REALLOC_ARRAY(prune, prune_num);
1875                         prune[prune_num-2] = ce->name;
1876                         prune[prune_num-1] = NULL;
1877                 }
1878                 while ((i+1 < istate->cache_nr) &&
1879                        ce_same_name(ce, istate->cache[i+1]))
1880                         i++;
1881         }
1882         clear_pathspec(&revs->prune_data);
1883         parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1884                        PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1885         revs->limited = 1;
1886 }
1887
1888 static int dotdot_missing(const char *arg, char *dotdot,
1889                           struct rev_info *revs, int symmetric)
1890 {
1891         if (revs->ignore_missing)
1892                 return 0;
1893         /* de-munge so we report the full argument */
1894         *dotdot = '.';
1895         die(symmetric
1896             ? "Invalid symmetric difference expression %s"
1897             : "Invalid revision range %s", arg);
1898 }
1899
1900 static int handle_dotdot_1(const char *arg, char *dotdot,
1901                            struct rev_info *revs, int flags,
1902                            int cant_be_filename,
1903                            struct object_context *a_oc,
1904                            struct object_context *b_oc)
1905 {
1906         const char *a_name, *b_name;
1907         struct object_id a_oid, b_oid;
1908         struct object *a_obj, *b_obj;
1909         unsigned int a_flags, b_flags;
1910         int symmetric = 0;
1911         unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1912         unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;
1913
1914         a_name = arg;
1915         if (!*a_name)
1916                 a_name = "HEAD";
1917
1918         b_name = dotdot + 2;
1919         if (*b_name == '.') {
1920                 symmetric = 1;
1921                 b_name++;
1922         }
1923         if (!*b_name)
1924                 b_name = "HEAD";
1925
1926         if (get_oid_with_context(revs->repo, a_name, oc_flags, &a_oid, a_oc) ||
1927             get_oid_with_context(revs->repo, b_name, oc_flags, &b_oid, b_oc))
1928                 return -1;
1929
1930         if (!cant_be_filename) {
1931                 *dotdot = '.';
1932                 verify_non_filename(revs->prefix, arg);
1933                 *dotdot = '\0';
1934         }
1935
1936         a_obj = parse_object(revs->repo, &a_oid);
1937         b_obj = parse_object(revs->repo, &b_oid);
1938         if (!a_obj || !b_obj)
1939                 return dotdot_missing(arg, dotdot, revs, symmetric);
1940
1941         if (!symmetric) {
1942                 /* just A..B */
1943                 b_flags = flags;
1944                 a_flags = flags_exclude;
1945         } else {
1946                 /* A...B -- find merge bases between the two */
1947                 struct commit *a, *b;
1948                 struct commit_list *exclude;
1949
1950                 a = lookup_commit_reference(revs->repo, &a_obj->oid);
1951                 b = lookup_commit_reference(revs->repo, &b_obj->oid);
1952                 if (!a || !b)
1953                         return dotdot_missing(arg, dotdot, revs, symmetric);
1954
1955                 exclude = get_merge_bases(a, b);
1956                 add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1957                                      flags_exclude);
1958                 add_pending_commit_list(revs, exclude, flags_exclude);
1959                 free_commit_list(exclude);
1960
1961                 b_flags = flags;
1962                 a_flags = flags | SYMMETRIC_LEFT;
1963         }
1964
1965         a_obj->flags |= a_flags;
1966         b_obj->flags |= b_flags;
1967         add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1968         add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1969         add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1970         add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1971         return 0;
1972 }
1973
1974 static int handle_dotdot(const char *arg,
1975                          struct rev_info *revs, int flags,
1976                          int cant_be_filename)
1977 {
1978         struct object_context a_oc, b_oc;
1979         char *dotdot = strstr(arg, "..");
1980         int ret;
1981
1982         if (!dotdot)
1983                 return -1;
1984
1985         memset(&a_oc, 0, sizeof(a_oc));
1986         memset(&b_oc, 0, sizeof(b_oc));
1987
1988         *dotdot = '\0';
1989         ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
1990                               &a_oc, &b_oc);
1991         *dotdot = '.';
1992
1993         free(a_oc.path);
1994         free(b_oc.path);
1995
1996         return ret;
1997 }
1998
1999 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
2000 {
2001         struct object_context oc;
2002         char *mark;
2003         struct object *object;
2004         struct object_id oid;
2005         int local_flags;
2006         const char *arg = arg_;
2007         int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
2008         unsigned get_sha1_flags = GET_OID_RECORD_PATH;
2009
2010         flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
2011
2012         if (!cant_be_filename && !strcmp(arg, "..")) {
2013                 /*
2014                  * Just ".."?  That is not a range but the
2015                  * pathspec for the parent directory.
2016                  */
2017                 return -1;
2018         }
2019
2020         if (!handle_dotdot(arg, revs, flags, revarg_opt))
2021                 return 0;
2022
2023         mark = strstr(arg, "^@");
2024         if (mark && !mark[2]) {
2025                 *mark = 0;
2026                 if (add_parents_only(revs, arg, flags, 0))
2027                         return 0;
2028                 *mark = '^';
2029         }
2030         mark = strstr(arg, "^!");
2031         if (mark && !mark[2]) {
2032                 *mark = 0;
2033                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
2034                         *mark = '^';
2035         }
2036         mark = strstr(arg, "^-");
2037         if (mark) {
2038                 int exclude_parent = 1;
2039
2040                 if (mark[2]) {
2041                         char *end;
2042                         exclude_parent = strtoul(mark + 2, &end, 10);
2043                         if (*end != '\0' || !exclude_parent)
2044                                 return -1;
2045                 }
2046
2047                 *mark = 0;
2048                 if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
2049                         *mark = '^';
2050         }
2051
2052         local_flags = 0;
2053         if (*arg == '^') {
2054                 local_flags = UNINTERESTING | BOTTOM;
2055                 arg++;
2056         }
2057
2058         if (revarg_opt & REVARG_COMMITTISH)
2059                 get_sha1_flags |= GET_OID_COMMITTISH;
2060
2061         if (get_oid_with_context(revs->repo, arg, get_sha1_flags, &oid, &oc))
2062                 return revs->ignore_missing ? 0 : -1;
2063         if (!cant_be_filename)
2064                 verify_non_filename(revs->prefix, arg);
2065         object = get_reference(revs, arg, &oid, flags ^ local_flags);
2066         if (!object)
2067                 return revs->ignore_missing ? 0 : -1;
2068         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
2069         add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
2070         free(oc.path);
2071         return 0;
2072 }
2073
2074 static void read_pathspec_from_stdin(struct strbuf *sb,
2075                                      struct argv_array *prune)
2076 {
2077         while (strbuf_getline(sb, stdin) != EOF)
2078                 argv_array_push(prune, sb->buf);
2079 }
2080
2081 static void read_revisions_from_stdin(struct rev_info *revs,
2082                                       struct argv_array *prune)
2083 {
2084         struct strbuf sb;
2085         int seen_dashdash = 0;
2086         int save_warning;
2087
2088         save_warning = warn_on_object_refname_ambiguity;
2089         warn_on_object_refname_ambiguity = 0;
2090
2091         strbuf_init(&sb, 1000);
2092         while (strbuf_getline(&sb, stdin) != EOF) {
2093                 int len = sb.len;
2094                 if (!len)
2095                         break;
2096                 if (sb.buf[0] == '-') {
2097                         if (len == 2 && sb.buf[1] == '-') {
2098                                 seen_dashdash = 1;
2099                                 break;
2100                         }
2101                         die("options not supported in --stdin mode");
2102                 }
2103                 if (handle_revision_arg(sb.buf, revs, 0,
2104                                         REVARG_CANNOT_BE_FILENAME))
2105                         die("bad revision '%s'", sb.buf);
2106         }
2107         if (seen_dashdash)
2108                 read_pathspec_from_stdin(&sb, prune);
2109
2110         strbuf_release(&sb);
2111         warn_on_object_refname_ambiguity = save_warning;
2112 }
2113
2114 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
2115 {
2116         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
2117 }
2118
2119 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
2120 {
2121         append_header_grep_pattern(&revs->grep_filter, field, pattern);
2122 }
2123
2124 static void add_message_grep(struct rev_info *revs, const char *pattern)
2125 {
2126         add_grep(revs, pattern, GREP_PATTERN_BODY);
2127 }
2128
2129 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
2130                                int *unkc, const char **unkv,
2131                                const struct setup_revision_opt* opt)
2132 {
2133         const char *arg = argv[0];
2134         const char *optarg;
2135         int argcount;
2136         const unsigned hexsz = the_hash_algo->hexsz;
2137
2138         /* pseudo revision arguments */
2139         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
2140             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
2141             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
2142             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
2143             !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
2144             !strcmp(arg, "--indexed-objects") ||
2145             !strcmp(arg, "--alternate-refs") ||
2146             starts_with(arg, "--exclude=") ||
2147             starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
2148             starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
2149         {
2150                 unkv[(*unkc)++] = arg;
2151                 return 1;
2152         }
2153
2154         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
2155                 revs->max_count = atoi(optarg);
2156                 revs->no_walk = 0;
2157                 return argcount;
2158         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
2159                 revs->skip_count = atoi(optarg);
2160                 return argcount;
2161         } else if ((*arg == '-') && isdigit(arg[1])) {
2162                 /* accept -<digit>, like traditional "head" */
2163                 if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
2164                     revs->max_count < 0)
2165                         die("'%s': not a non-negative integer", arg + 1);
2166                 revs->no_walk = 0;
2167         } else if (!strcmp(arg, "-n")) {
2168                 if (argc <= 1)
2169                         return error("-n requires an argument");
2170                 revs->max_count = atoi(argv[1]);
2171                 revs->no_walk = 0;
2172                 return 2;
2173         } else if (skip_prefix(arg, "-n", &optarg)) {
2174                 revs->max_count = atoi(optarg);
2175                 revs->no_walk = 0;
2176         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
2177                 revs->max_age = atoi(optarg);
2178                 return argcount;
2179         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
2180                 revs->max_age = approxidate(optarg);
2181                 return argcount;
2182         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
2183                 revs->max_age = approxidate(optarg);
2184                 return argcount;
2185         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
2186                 revs->min_age = atoi(optarg);
2187                 return argcount;
2188         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
2189                 revs->min_age = approxidate(optarg);
2190                 return argcount;
2191         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
2192                 revs->min_age = approxidate(optarg);
2193                 return argcount;
2194         } else if (!strcmp(arg, "--first-parent")) {
2195                 revs->first_parent_only = 1;
2196         } else if (!strcmp(arg, "--ancestry-path")) {
2197                 revs->ancestry_path = 1;
2198                 revs->simplify_history = 0;
2199                 revs->limited = 1;
2200         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
2201                 init_reflog_walk(&revs->reflog_info);
2202         } else if (!strcmp(arg, "--default")) {
2203                 if (argc <= 1)
2204                         return error("bad --default argument");
2205                 revs->def = argv[1];
2206                 return 2;
2207         } else if (!strcmp(arg, "--merge")) {
2208                 revs->show_merge = 1;
2209         } else if (!strcmp(arg, "--topo-order")) {
2210                 revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
2211                 revs->topo_order = 1;
2212         } else if (!strcmp(arg, "--simplify-merges")) {
2213                 revs->simplify_merges = 1;
2214                 revs->topo_order = 1;
2215                 revs->rewrite_parents = 1;
2216                 revs->simplify_history = 0;
2217                 revs->limited = 1;
2218         } else if (!strcmp(arg, "--simplify-by-decoration")) {
2219                 revs->simplify_merges = 1;
2220                 revs->topo_order = 1;
2221                 revs->rewrite_parents = 1;
2222                 revs->simplify_history = 0;
2223                 revs->simplify_by_decoration = 1;
2224                 revs->limited = 1;
2225                 revs->prune = 1;
2226         } else if (!strcmp(arg, "--date-order")) {
2227                 revs->sort_order = REV_SORT_BY_COMMIT_DATE;
2228                 revs->topo_order = 1;
2229         } else if (!strcmp(arg, "--author-date-order")) {
2230                 revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
2231                 revs->topo_order = 1;
2232         } else if (!strcmp(arg, "--early-output")) {
2233                 revs->early_output = 100;
2234                 revs->topo_order = 1;
2235         } else if (skip_prefix(arg, "--early-output=", &optarg)) {
2236                 if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
2237                         die("'%s': not a non-negative integer", optarg);
2238                 revs->topo_order = 1;
2239         } else if (!strcmp(arg, "--parents")) {
2240                 revs->rewrite_parents = 1;
2241                 revs->print_parents = 1;
2242         } else if (!strcmp(arg, "--dense")) {
2243                 revs->dense = 1;
2244         } else if (!strcmp(arg, "--sparse")) {
2245                 revs->dense = 0;
2246         } else if (!strcmp(arg, "--in-commit-order")) {
2247                 revs->tree_blobs_in_commit_order = 1;
2248         } else if (!strcmp(arg, "--remove-empty")) {
2249                 revs->remove_empty_trees = 1;
2250         } else if (!strcmp(arg, "--merges")) {
2251                 revs->min_parents = 2;
2252         } else if (!strcmp(arg, "--no-merges")) {
2253                 revs->max_parents = 1;
2254         } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
2255                 revs->min_parents = atoi(optarg);
2256         } else if (!strcmp(arg, "--no-min-parents")) {
2257                 revs->min_parents = 0;
2258         } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
2259                 revs->max_parents = atoi(optarg);
2260         } else if (!strcmp(arg, "--no-max-parents")) {
2261                 revs->max_parents = -1;
2262         } else if (!strcmp(arg, "--boundary")) {
2263                 revs->boundary = 1;
2264         } else if (!strcmp(arg, "--left-right")) {
2265                 revs->left_right = 1;
2266         } else if (!strcmp(arg, "--left-only")) {
2267                 if (revs->right_only)
2268                         die("--left-only is incompatible with --right-only"
2269                             " or --cherry");
2270                 revs->left_only = 1;
2271         } else if (!strcmp(arg, "--right-only")) {
2272                 if (revs->left_only)
2273                         die("--right-only is incompatible with --left-only");
2274                 revs->right_only = 1;
2275         } else if (!strcmp(arg, "--cherry")) {
2276                 if (revs->left_only)
2277                         die("--cherry is incompatible with --left-only");
2278                 revs->cherry_mark = 1;
2279                 revs->right_only = 1;
2280                 revs->max_parents = 1;
2281                 revs->limited = 1;
2282         } else if (!strcmp(arg, "--count")) {
2283                 revs->count = 1;
2284         } else if (!strcmp(arg, "--cherry-mark")) {
2285                 if (revs->cherry_pick)
2286                         die("--cherry-mark is incompatible with --cherry-pick");
2287                 revs->cherry_mark = 1;
2288                 revs->limited = 1; /* needs limit_list() */
2289         } else if (!strcmp(arg, "--cherry-pick")) {
2290                 if (revs->cherry_mark)
2291                         die("--cherry-pick is incompatible with --cherry-mark");
2292                 revs->cherry_pick = 1;
2293                 revs->limited = 1;
2294         } else if (!strcmp(arg, "--objects")) {
2295                 revs->tag_objects = 1;
2296                 revs->tree_objects = 1;
2297                 revs->blob_objects = 1;
2298         } else if (!strcmp(arg, "--objects-edge")) {
2299                 revs->tag_objects = 1;
2300                 revs->tree_objects = 1;
2301                 revs->blob_objects = 1;
2302                 revs->edge_hint = 1;
2303         } else if (!strcmp(arg, "--objects-edge-aggressive")) {
2304                 revs->tag_objects = 1;
2305                 revs->tree_objects = 1;
2306                 revs->blob_objects = 1;
2307                 revs->edge_hint = 1;
2308                 revs->edge_hint_aggressive = 1;
2309         } else if (!strcmp(arg, "--verify-objects")) {
2310                 revs->tag_objects = 1;
2311                 revs->tree_objects = 1;
2312                 revs->blob_objects = 1;
2313                 revs->verify_objects = 1;
2314         } else if (!strcmp(arg, "--unpacked")) {
2315                 revs->unpacked = 1;
2316         } else if (starts_with(arg, "--unpacked=")) {
2317                 die("--unpacked=<packfile> no longer supported.");
2318         } else if (!strcmp(arg, "-r")) {
2319                 revs->diff = 1;
2320                 revs->diffopt.flags.recursive = 1;
2321         } else if (!strcmp(arg, "-t")) {
2322                 revs->diff = 1;
2323                 revs->diffopt.flags.recursive = 1;
2324                 revs->diffopt.flags.tree_in_recursive = 1;
2325         } else if (!strcmp(arg, "-m")) {
2326                 revs->ignore_merges = 0;
2327         } else if (!strcmp(arg, "-c")) {
2328                 revs->diff = 1;
2329                 revs->dense_combined_merges = 0;
2330                 revs->combine_merges = 1;
2331         } else if (!strcmp(arg, "--combined-all-paths")) {
2332                 revs->diff = 1;
2333                 revs->combined_all_paths = 1;
2334         } else if (!strcmp(arg, "--cc")) {
2335                 revs->diff = 1;
2336                 revs->dense_combined_merges = 1;
2337                 revs->combine_merges = 1;
2338         } else if (!strcmp(arg, "-v")) {
2339                 revs->verbose_header = 1;
2340         } else if (!strcmp(arg, "--pretty")) {
2341                 revs->verbose_header = 1;
2342                 revs->pretty_given = 1;
2343                 get_commit_format(NULL, revs);
2344         } else if (skip_prefix(arg, "--pretty=", &optarg) ||
2345                    skip_prefix(arg, "--format=", &optarg)) {
2346                 /*
2347                  * Detached form ("--pretty X" as opposed to "--pretty=X")
2348                  * not allowed, since the argument is optional.
2349                  */
2350                 revs->verbose_header = 1;
2351                 revs->pretty_given = 1;
2352                 get_commit_format(optarg, revs);
2353         } else if (!strcmp(arg, "--expand-tabs")) {
2354                 revs->expand_tabs_in_log = 8;
2355         } else if (!strcmp(arg, "--no-expand-tabs")) {
2356                 revs->expand_tabs_in_log = 0;
2357         } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
2358                 int val;
2359                 if (strtol_i(arg, 10, &val) < 0 || val < 0)
2360                         die("'%s': not a non-negative integer", arg);
2361                 revs->expand_tabs_in_log = val;
2362         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
2363                 enable_default_display_notes(&revs->notes_opt, &revs->show_notes);
2364                 revs->show_notes_given = 1;
2365         } else if (!strcmp(arg, "--show-signature")) {
2366                 revs->show_signature = 1;
2367         } else if (!strcmp(arg, "--no-show-signature")) {
2368                 revs->show_signature = 0;
2369         } else if (!strcmp(arg, "--show-linear-break")) {
2370                 revs->break_bar = "                    ..........";
2371                 revs->track_linear = 1;
2372                 revs->track_first_time = 1;
2373         } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
2374                 revs->break_bar = xstrdup(optarg);
2375                 revs->track_linear = 1;
2376                 revs->track_first_time = 1;
2377         } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
2378                    skip_prefix(arg, "--notes=", &optarg)) {
2379                 if (starts_with(arg, "--show-notes=") &&
2380                     revs->notes_opt.use_default_notes < 0)
2381                         revs->notes_opt.use_default_notes = 1;
2382                 enable_ref_display_notes(&revs->notes_opt, &revs->show_notes, optarg);
2383                 revs->show_notes_given = 1;
2384         } else if (!strcmp(arg, "--no-notes")) {
2385                 disable_display_notes(&revs->notes_opt, &revs->show_notes);
2386                 revs->show_notes_given = 1;
2387         } else if (!strcmp(arg, "--standard-notes")) {
2388                 revs->show_notes_given = 1;
2389                 revs->notes_opt.use_default_notes = 1;
2390         } else if (!strcmp(arg, "--no-standard-notes")) {
2391                 revs->notes_opt.use_default_notes = 0;
2392         } else if (!strcmp(arg, "--oneline")) {
2393                 revs->verbose_header = 1;
2394                 get_commit_format("oneline", revs);
2395                 revs->pretty_given = 1;
2396                 revs->abbrev_commit = 1;
2397         } else if (!strcmp(arg, "--graph")) {
2398                 revs->topo_order = 1;
2399                 revs->rewrite_parents = 1;
2400                 revs->graph = graph_init(revs);
2401         } else if (!strcmp(arg, "--encode-email-headers")) {
2402                 revs->encode_email_headers = 1;
2403         } else if (!strcmp(arg, "--no-encode-email-headers")) {
2404                 revs->encode_email_headers = 0;
2405         } else if (!strcmp(arg, "--root")) {
2406                 revs->show_root_diff = 1;
2407         } else if (!strcmp(arg, "--no-commit-id")) {
2408                 revs->no_commit_id = 1;
2409         } else if (!strcmp(arg, "--always")) {
2410                 revs->always_show_header = 1;
2411         } else if (!strcmp(arg, "--no-abbrev")) {
2412                 revs->abbrev = 0;
2413         } else if (!strcmp(arg, "--abbrev")) {
2414                 revs->abbrev = DEFAULT_ABBREV;
2415         } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
2416                 revs->abbrev = strtoul(optarg, NULL, 10);
2417                 if (revs->abbrev < MINIMUM_ABBREV)
2418                         revs->abbrev = MINIMUM_ABBREV;
2419                 else if (revs->abbrev > hexsz)
2420                         revs->abbrev = hexsz;
2421         } else if (!strcmp(arg, "--abbrev-commit")) {
2422                 revs->abbrev_commit = 1;
2423                 revs->abbrev_commit_given = 1;
2424         } else if (!strcmp(arg, "--no-abbrev-commit")) {
2425                 revs->abbrev_commit = 0;
2426         } else if (!strcmp(arg, "--full-diff")) {
2427                 revs->diff = 1;
2428                 revs->full_diff = 1;
2429         } else if (!strcmp(arg, "--show-pulls")) {
2430                 revs->show_pulls = 1;
2431         } else if (!strcmp(arg, "--full-history")) {
2432                 revs->simplify_history = 0;
2433         } else if (!strcmp(arg, "--relative-date")) {
2434                 revs->date_mode.type = DATE_RELATIVE;
2435                 revs->date_mode_explicit = 1;
2436         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2437                 parse_date_format(optarg, &revs->date_mode);
2438                 revs->date_mode_explicit = 1;
2439                 return argcount;
2440         } else if (!strcmp(arg, "--log-size")) {
2441                 revs->show_log_size = 1;
2442         }
2443         /*
2444          * Grepping the commit log
2445          */
2446         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2447                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2448                 return argcount;
2449         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2450                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2451                 return argcount;
2452         } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2453                 add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2454                 return argcount;
2455         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2456                 add_message_grep(revs, optarg);
2457                 return argcount;
2458         } else if (!strcmp(arg, "--grep-debug")) {
2459                 revs->grep_filter.debug = 1;
2460         } else if (!strcmp(arg, "--basic-regexp")) {
2461                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2462         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2463                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2464         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2465                 revs->grep_filter.ignore_case = 1;
2466                 revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
2467         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2468                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2469         } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2470                 revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2471         } else if (!strcmp(arg, "--all-match")) {
2472                 revs->grep_filter.all_match = 1;
2473         } else if (!strcmp(arg, "--invert-grep")) {
2474                 revs->invert_grep = 1;
2475         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2476                 if (strcmp(optarg, "none"))
2477                         git_log_output_encoding = xstrdup(optarg);
2478                 else
2479                         git_log_output_encoding = "";
2480                 return argcount;
2481         } else if (!strcmp(arg, "--reverse")) {
2482                 revs->reverse ^= 1;
2483         } else if (!strcmp(arg, "--children")) {
2484                 revs->children.name = "children";
2485                 revs->limited = 1;
2486         } else if (!strcmp(arg, "--ignore-missing")) {
2487                 revs->ignore_missing = 1;
2488         } else if (opt && opt->allow_exclude_promisor_objects &&
2489                    !strcmp(arg, "--exclude-promisor-objects")) {
2490                 if (fetch_if_missing)
2491                         BUG("exclude_promisor_objects can only be used when fetch_if_missing is 0");
2492                 revs->exclude_promisor_objects = 1;
2493         } else {
2494                 int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2495                 if (!opts)
2496                         unkv[(*unkc)++] = arg;
2497                 return opts;
2498         }
2499         if (revs->graph && revs->track_linear)
2500                 die("--show-linear-break and --graph are incompatible");
2501
2502         return 1;
2503 }
2504
2505 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2506                         const struct option *options,
2507                         const char * const usagestr[])
2508 {
2509         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2510                                     &ctx->cpidx, ctx->out, NULL);
2511         if (n <= 0) {
2512                 error("unknown option `%s'", ctx->argv[0]);
2513                 usage_with_options(usagestr, options);
2514         }
2515         ctx->argv += n;
2516         ctx->argc -= n;
2517 }
2518
2519 static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
2520                                void *cb_data, const char *term)
2521 {
2522         struct strbuf bisect_refs = STRBUF_INIT;
2523         int status;
2524         strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2525         status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
2526         strbuf_release(&bisect_refs);
2527         return status;
2528 }
2529
2530 static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2531 {
2532         return for_each_bisect_ref(refs, fn, cb_data, term_bad);
2533 }
2534
2535 static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2536 {
2537         return for_each_bisect_ref(refs, fn, cb_data, term_good);
2538 }
2539
2540 static int handle_revision_pseudo_opt(const char *submodule,
2541                                 struct rev_info *revs,
2542                                 int argc, const char **argv, int *flags)
2543 {
2544         const char *arg = argv[0];
2545         const char *optarg;
2546         struct ref_store *refs;
2547         int argcount;
2548
2549         if (submodule) {
2550                 /*
2551                  * We need some something like get_submodule_worktrees()
2552                  * before we can go through all worktrees of a submodule,
2553                  * .e.g with adding all HEADs from --all, which is not
2554                  * supported right now, so stick to single worktree.
2555                  */
2556                 if (!revs->single_worktree)
2557                         BUG("--single-worktree cannot be used together with submodule");
2558                 refs = get_submodule_ref_store(submodule);
2559         } else
2560                 refs = get_main_ref_store(revs->repo);
2561
2562         /*
2563          * NOTE!
2564          *
2565          * Commands like "git shortlog" will not accept the options below
2566          * unless parse_revision_opt queues them (as opposed to erroring
2567          * out).
2568          *
2569          * When implementing your new pseudo-option, remember to
2570          * register it in the list at the top of handle_revision_opt.
2571          */
2572         if (!strcmp(arg, "--all")) {
2573                 handle_refs(refs, revs, *flags, refs_for_each_ref);
2574                 handle_refs(refs, revs, *flags, refs_head_ref);
2575                 if (!revs->single_worktree) {
2576                         struct all_refs_cb cb;
2577
2578                         init_all_refs_cb(&cb, revs, *flags);
2579                         other_head_refs(handle_one_ref, &cb);
2580                 }
2581                 clear_ref_exclusion(&revs->ref_excludes);
2582         } else if (!strcmp(arg, "--branches")) {
2583                 handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
2584                 clear_ref_exclusion(&revs->ref_excludes);
2585         } else if (!strcmp(arg, "--bisect")) {
2586                 read_bisect_terms(&term_bad, &term_good);
2587                 handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
2588                 handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
2589                             for_each_good_bisect_ref);
2590                 revs->bisect = 1;
2591         } else if (!strcmp(arg, "--tags")) {
2592                 handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
2593                 clear_ref_exclusion(&revs->ref_excludes);
2594         } else if (!strcmp(arg, "--remotes")) {
2595                 handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
2596                 clear_ref_exclusion(&revs->ref_excludes);
2597         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2598                 struct all_refs_cb cb;
2599                 init_all_refs_cb(&cb, revs, *flags);
2600                 for_each_glob_ref(handle_one_ref, optarg, &cb);
2601                 clear_ref_exclusion(&revs->ref_excludes);
2602                 return argcount;
2603         } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2604                 add_ref_exclusion(&revs->ref_excludes, optarg);
2605                 return argcount;
2606         } else if (skip_prefix(arg, "--branches=", &optarg)) {
2607                 struct all_refs_cb cb;
2608                 init_all_refs_cb(&cb, revs, *flags);
2609                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2610                 clear_ref_exclusion(&revs->ref_excludes);
2611         } else if (skip_prefix(arg, "--tags=", &optarg)) {
2612                 struct all_refs_cb cb;
2613                 init_all_refs_cb(&cb, revs, *flags);
2614                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2615                 clear_ref_exclusion(&revs->ref_excludes);
2616         } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2617                 struct all_refs_cb cb;
2618                 init_all_refs_cb(&cb, revs, *flags);
2619                 for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2620                 clear_ref_exclusion(&revs->ref_excludes);
2621         } else if (!strcmp(arg, "--reflog")) {
2622                 add_reflogs_to_pending(revs, *flags);
2623         } else if (!strcmp(arg, "--indexed-objects")) {
2624                 add_index_objects_to_pending(revs, *flags);
2625         } else if (!strcmp(arg, "--alternate-refs")) {
2626                 add_alternate_refs_to_pending(revs, *flags);
2627         } else if (!strcmp(arg, "--not")) {
2628                 *flags ^= UNINTERESTING | BOTTOM;
2629         } else if (!strcmp(arg, "--no-walk")) {
2630                 revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2631         } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2632                 /*
2633                  * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2634                  * not allowed, since the argument is optional.
2635                  */
2636                 if (!strcmp(optarg, "sorted"))
2637                         revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2638                 else if (!strcmp(optarg, "unsorted"))
2639                         revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2640                 else
2641                         return error("invalid argument to --no-walk");
2642         } else if (!strcmp(arg, "--do-walk")) {
2643                 revs->no_walk = 0;
2644         } else if (!strcmp(arg, "--single-worktree")) {
2645                 revs->single_worktree = 1;
2646         } else {
2647                 return 0;
2648         }
2649
2650         return 1;
2651 }
2652
2653 static void NORETURN diagnose_missing_default(const char *def)
2654 {
2655         int flags;
2656         const char *refname;
2657
2658         refname = resolve_ref_unsafe(def, 0, NULL, &flags);
2659         if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2660                 die(_("your current branch appears to be broken"));
2661
2662         skip_prefix(refname, "refs/heads/", &refname);
2663         die(_("your current branch '%s' does not have any commits yet"),
2664             refname);
2665 }
2666
2667 /*
2668  * Parse revision information, filling in the "rev_info" structure,
2669  * and removing the used arguments from the argument list.
2670  *
2671  * Returns the number of arguments left that weren't recognized
2672  * (which are also moved to the head of the argument list)
2673  */
2674 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2675 {
2676         int i, flags, left, seen_dashdash, got_rev_arg = 0, revarg_opt;
2677         struct argv_array prune_data = ARGV_ARRAY_INIT;
2678         const char *submodule = NULL;
2679         int seen_end_of_options = 0;
2680
2681         if (opt)
2682                 submodule = opt->submodule;
2683
2684         /* First, search for "--" */
2685         if (opt && opt->assume_dashdash) {
2686                 seen_dashdash = 1;
2687         } else {
2688                 seen_dashdash = 0;
2689                 for (i = 1; i < argc; i++) {
2690                         const char *arg = argv[i];
2691                         if (strcmp(arg, "--"))
2692                                 continue;
2693                         argv[i] = NULL;
2694                         argc = i;
2695                         if (argv[i + 1])
2696                                 argv_array_pushv(&prune_data, argv + i + 1);
2697                         seen_dashdash = 1;
2698                         break;
2699                 }
2700         }
2701
2702         /* Second, deal with arguments and options */
2703         flags = 0;
2704         revarg_opt = opt ? opt->revarg_opt : 0;
2705         if (seen_dashdash)
2706                 revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2707         for (left = i = 1; i < argc; i++) {
2708                 const char *arg = argv[i];
2709                 if (!seen_end_of_options && *arg == '-') {
2710                         int opts;
2711
2712                         opts = handle_revision_pseudo_opt(submodule,
2713                                                 revs, argc - i, argv + i,
2714                                                 &flags);
2715                         if (opts > 0) {
2716                                 i += opts - 1;
2717                                 continue;
2718                         }
2719
2720                         if (!strcmp(arg, "--stdin")) {
2721                                 if (revs->disable_stdin) {
2722                                         argv[left++] = arg;
2723                                         continue;
2724                                 }
2725                                 if (revs->read_from_stdin++)
2726                                         die("--stdin given twice?");
2727                                 read_revisions_from_stdin(revs, &prune_data);
2728                                 continue;
2729                         }
2730
2731                         if (!strcmp(arg, "--end-of-options")) {
2732                                 seen_end_of_options = 1;
2733                                 continue;
2734                         }
2735
2736                         opts = handle_revision_opt(revs, argc - i, argv + i,
2737                                                    &left, argv, opt);
2738                         if (opts > 0) {
2739                                 i += opts - 1;
2740                                 continue;
2741                         }
2742                         if (opts < 0)
2743                                 exit(128);
2744                         continue;
2745                 }
2746
2747
2748                 if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2749                         int j;
2750                         if (seen_dashdash || *arg == '^')
2751                                 die("bad revision '%s'", arg);
2752
2753                         /* If we didn't have a "--":
2754                          * (1) all filenames must exist;
2755                          * (2) all rev-args must not be interpretable
2756                          *     as a valid filename.
2757                          * but the latter we have checked in the main loop.
2758                          */
2759                         for (j = i; j < argc; j++)
2760                                 verify_filename(revs->prefix, argv[j], j == i);
2761
2762                         argv_array_pushv(&prune_data, argv + i);
2763                         break;
2764                 }
2765                 else
2766                         got_rev_arg = 1;
2767         }
2768
2769         if (prune_data.argc) {
2770                 /*
2771                  * If we need to introduce the magic "a lone ':' means no
2772                  * pathspec whatsoever", here is the place to do so.
2773                  *
2774                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2775                  *      prune_data.nr = 0;
2776                  *      prune_data.alloc = 0;
2777                  *      free(prune_data.path);
2778                  *      prune_data.path = NULL;
2779                  * } else {
2780                  *      terminate prune_data.alloc with NULL and
2781                  *      call init_pathspec() to set revs->prune_data here.
2782                  * }
2783                  */
2784                 parse_pathspec(&revs->prune_data, 0, 0,
2785                                revs->prefix, prune_data.argv);
2786         }
2787         argv_array_clear(&prune_data);
2788
2789         if (revs->def == NULL)
2790                 revs->def = opt ? opt->def : NULL;
2791         if (opt && opt->tweak)
2792                 opt->tweak(revs, opt);
2793         if (revs->show_merge)
2794                 prepare_show_merge(revs);
2795         if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
2796                 struct object_id oid;
2797                 struct object *object;
2798                 struct object_context oc;
2799                 if (get_oid_with_context(revs->repo, revs->def, 0, &oid, &oc))
2800                         diagnose_missing_default(revs->def);
2801                 object = get_reference(revs, revs->def, &oid, 0);
2802                 add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2803         }
2804
2805         /* Did the user ask for any diff output? Run the diff! */
2806         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2807                 revs->diff = 1;
2808
2809         /* Pickaxe, diff-filter and rename following need diffs */
2810         if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
2811             revs->diffopt.filter ||
2812             revs->diffopt.flags.follow_renames)
2813                 revs->diff = 1;
2814
2815         if (revs->diffopt.objfind)
2816                 revs->simplify_history = 0;
2817
2818         if (revs->line_level_traverse) {
2819                 if (want_ancestry(revs))
2820                         revs->limited = 1;
2821                 revs->topo_order = 1;
2822         }
2823
2824         if (revs->topo_order && !generation_numbers_enabled(the_repository))
2825                 revs->limited = 1;
2826
2827         if (revs->prune_data.nr) {
2828                 copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2829                 /* Can't prune commits with rename following: the paths change.. */
2830                 if (!revs->diffopt.flags.follow_renames)
2831                         revs->prune = 1;
2832                 if (!revs->full_diff)
2833                         copy_pathspec(&revs->diffopt.pathspec,
2834                                       &revs->prune_data);
2835         }
2836         if (revs->combine_merges)
2837                 revs->ignore_merges = 0;
2838         if (revs->combined_all_paths && !revs->combine_merges)
2839                 die("--combined-all-paths makes no sense without -c or --cc");
2840
2841         revs->diffopt.abbrev = revs->abbrev;
2842
2843         diff_setup_done(&revs->diffopt);
2844
2845         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2846                                  &revs->grep_filter);
2847         if (!is_encoding_utf8(get_log_output_encoding()))
2848                 revs->grep_filter.ignore_locale = 1;
2849         compile_grep_patterns(&revs->grep_filter);
2850
2851         if (revs->reverse && revs->reflog_info)
2852                 die("cannot combine --reverse with --walk-reflogs");
2853         if (revs->reflog_info && revs->limited)
2854                 die("cannot combine --walk-reflogs with history-limiting options");
2855         if (revs->rewrite_parents && revs->children.name)
2856                 die("cannot combine --parents and --children");
2857
2858         /*
2859          * Limitations on the graph functionality
2860          */
2861         if (revs->reverse && revs->graph)
2862                 die("cannot combine --reverse with --graph");
2863
2864         if (revs->reflog_info && revs->graph)
2865                 die("cannot combine --walk-reflogs with --graph");
2866         if (revs->no_walk && revs->graph)
2867                 die("cannot combine --no-walk with --graph");
2868         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2869                 die("cannot use --grep-reflog without --walk-reflogs");
2870
2871         if (revs->first_parent_only && revs->bisect)
2872                 die(_("--first-parent is incompatible with --bisect"));
2873
2874         if (revs->line_level_traverse &&
2875             (revs->diffopt.output_format & ~(DIFF_FORMAT_PATCH | DIFF_FORMAT_NO_OUTPUT)))
2876                 die(_("-L does not yet support diff formats besides -p and -s"));
2877
2878         if (revs->expand_tabs_in_log < 0)
2879                 revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2880
2881         return left;
2882 }
2883
2884 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2885 {
2886         struct commit_list *l = xcalloc(1, sizeof(*l));
2887
2888         l->item = child;
2889         l->next = add_decoration(&revs->children, &parent->object, l);
2890 }
2891
2892 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2893 {
2894         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2895         struct commit_list **pp, *p;
2896         int surviving_parents;
2897
2898         /* Examine existing parents while marking ones we have seen... */
2899         pp = &commit->parents;
2900         surviving_parents = 0;
2901         while ((p = *pp) != NULL) {
2902                 struct commit *parent = p->item;
2903                 if (parent->object.flags & TMP_MARK) {
2904                         *pp = p->next;
2905                         if (ts)
2906                                 compact_treesame(revs, commit, surviving_parents);
2907                         continue;
2908                 }
2909                 parent->object.flags |= TMP_MARK;
2910                 surviving_parents++;
2911                 pp = &p->next;
2912         }
2913         /* clear the temporary mark */
2914         for (p = commit->parents; p; p = p->next) {
2915                 p->item->object.flags &= ~TMP_MARK;
2916         }
2917         /* no update_treesame() - removing duplicates can't affect TREESAME */
2918         return surviving_parents;
2919 }
2920
2921 struct merge_simplify_state {
2922         struct commit *simplified;
2923 };
2924
2925 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2926 {
2927         struct merge_simplify_state *st;
2928
2929         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2930         if (!st) {
2931                 st = xcalloc(1, sizeof(*st));
2932                 add_decoration(&revs->merge_simplification, &commit->object, st);
2933         }
2934         return st;
2935 }
2936
2937 static int mark_redundant_parents(struct commit *commit)
2938 {
2939         struct commit_list *h = reduce_heads(commit->parents);
2940         int i = 0, marked = 0;
2941         struct commit_list *po, *pn;
2942
2943         /* Want these for sanity-checking only */
2944         int orig_cnt = commit_list_count(commit->parents);
2945         int cnt = commit_list_count(h);
2946
2947         /*
2948          * Not ready to remove items yet, just mark them for now, based
2949          * on the output of reduce_heads(). reduce_heads outputs the reduced
2950          * set in its original order, so this isn't too hard.
2951          */
2952         po = commit->parents;
2953         pn = h;
2954         while (po) {
2955                 if (pn && po->item == pn->item) {
2956                         pn = pn->next;
2957                         i++;
2958                 } else {
2959                         po->item->object.flags |= TMP_MARK;
2960                         marked++;
2961                 }
2962                 po=po->next;
2963         }
2964
2965         if (i != cnt || cnt+marked != orig_cnt)
2966                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2967
2968         free_commit_list(h);
2969
2970         return marked;
2971 }
2972
2973 static int mark_treesame_root_parents(struct commit *commit)
2974 {
2975         struct commit_list *p;
2976         int marked = 0;
2977
2978         for (p = commit->parents; p; p = p->next) {
2979                 struct commit *parent = p->item;
2980                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2981                         parent->object.flags |= TMP_MARK;
2982                         marked++;
2983                 }
2984         }
2985
2986         return marked;
2987 }
2988
2989 /*
2990  * Awkward naming - this means one parent we are TREESAME to.
2991  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2992  * empty tree). Better name suggestions?
2993  */
2994 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2995 {
2996         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2997         struct commit *unmarked = NULL, *marked = NULL;
2998         struct commit_list *p;
2999         unsigned n;
3000
3001         for (p = commit->parents, n = 0; p; p = p->next, n++) {
3002                 if (ts->treesame[n]) {
3003                         if (p->item->object.flags & TMP_MARK) {
3004                                 if (!marked)
3005                                         marked = p->item;
3006                         } else {
3007                                 if (!unmarked) {
3008                                         unmarked = p->item;
3009                                         break;
3010                                 }
3011                         }
3012                 }
3013         }
3014
3015         /*
3016          * If we are TREESAME to a marked-for-deletion parent, but not to any
3017          * unmarked parents, unmark the first TREESAME parent. This is the
3018          * parent that the default simplify_history==1 scan would have followed,
3019          * and it doesn't make sense to omit that path when asking for a
3020          * simplified full history. Retaining it improves the chances of
3021          * understanding odd missed merges that took an old version of a file.
3022          *
3023          * Example:
3024          *
3025          *   I--------*X       A modified the file, but mainline merge X used
3026          *    \       /        "-s ours", so took the version from I. X is
3027          *     `-*A--'         TREESAME to I and !TREESAME to A.
3028          *
3029          * Default log from X would produce "I". Without this check,
3030          * --full-history --simplify-merges would produce "I-A-X", showing
3031          * the merge commit X and that it changed A, but not making clear that
3032          * it had just taken the I version. With this check, the topology above
3033          * is retained.
3034          *
3035          * Note that it is possible that the simplification chooses a different
3036          * TREESAME parent from the default, in which case this test doesn't
3037          * activate, and we _do_ drop the default parent. Example:
3038          *
3039          *   I------X         A modified the file, but it was reverted in B,
3040          *    \    /          meaning mainline merge X is TREESAME to both
3041          *    *A-*B           parents.
3042          *
3043          * Default log would produce "I" by following the first parent;
3044          * --full-history --simplify-merges will produce "I-A-B". But this is a
3045          * reasonable result - it presents a logical full history leading from
3046          * I to X, and X is not an important merge.
3047          */
3048         if (!unmarked && marked) {
3049                 marked->object.flags &= ~TMP_MARK;
3050                 return 1;
3051         }
3052
3053         return 0;
3054 }
3055
3056 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
3057 {
3058         struct commit_list **pp, *p;
3059         int nth_parent, removed = 0;
3060
3061         pp = &commit->parents;
3062         nth_parent = 0;
3063         while ((p = *pp) != NULL) {
3064                 struct commit *parent = p->item;
3065                 if (parent->object.flags & TMP_MARK) {
3066                         parent->object.flags &= ~TMP_MARK;
3067                         *pp = p->next;
3068                         free(p);
3069                         removed++;
3070                         compact_treesame(revs, commit, nth_parent);
3071                         continue;
3072                 }
3073                 pp = &p->next;
3074                 nth_parent++;
3075         }
3076
3077         /* Removing parents can only increase TREESAMEness */
3078         if (removed && !(commit->object.flags & TREESAME))
3079                 update_treesame(revs, commit);
3080
3081         return nth_parent;
3082 }
3083
3084 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
3085 {
3086         struct commit_list *p;
3087         struct commit *parent;
3088         struct merge_simplify_state *st, *pst;
3089         int cnt;
3090
3091         st = locate_simplify_state(revs, commit);
3092
3093         /*
3094          * Have we handled this one?
3095          */
3096         if (st->simplified)
3097                 return tail;
3098
3099         /*
3100          * An UNINTERESTING commit simplifies to itself, so does a
3101          * root commit.  We do not rewrite parents of such commit
3102          * anyway.
3103          */
3104         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
3105                 st->simplified = commit;
3106                 return tail;
3107         }
3108
3109         /*
3110          * Do we know what commit all of our parents that matter
3111          * should be rewritten to?  Otherwise we are not ready to
3112          * rewrite this one yet.
3113          */
3114         for (cnt = 0, p = commit->parents; p; p = p->next) {
3115                 pst = locate_simplify_state(revs, p->item);
3116                 if (!pst->simplified) {
3117                         tail = &commit_list_insert(p->item, tail)->next;
3118                         cnt++;
3119                 }
3120                 if (revs->first_parent_only)
3121                         break;
3122         }
3123         if (cnt) {
3124                 tail = &commit_list_insert(commit, tail)->next;
3125                 return tail;
3126         }
3127
3128         /*
3129          * Rewrite our list of parents. Note that this cannot
3130          * affect our TREESAME flags in any way - a commit is
3131          * always TREESAME to its simplification.
3132          */
3133         for (p = commit->parents; p; p = p->next) {
3134                 pst = locate_simplify_state(revs, p->item);
3135                 p->item = pst->simplified;
3136                 if (revs->first_parent_only)
3137                         break;
3138         }
3139
3140         if (revs->first_parent_only)
3141                 cnt = 1;
3142         else
3143                 cnt = remove_duplicate_parents(revs, commit);
3144
3145         /*
3146          * It is possible that we are a merge and one side branch
3147          * does not have any commit that touches the given paths;
3148          * in such a case, the immediate parent from that branch
3149          * will be rewritten to be the merge base.
3150          *
3151          *      o----X          X: the commit we are looking at;
3152          *     /    /           o: a commit that touches the paths;
3153          * ---o----'
3154          *
3155          * Further, a merge of an independent branch that doesn't
3156          * touch the path will reduce to a treesame root parent:
3157          *
3158          *  ----o----X          X: the commit we are looking at;
3159          *          /           o: a commit that touches the paths;
3160          *         r            r: a root commit not touching the paths
3161          *
3162          * Detect and simplify both cases.
3163          */
3164         if (1 < cnt) {
3165                 int marked = mark_redundant_parents(commit);
3166                 marked += mark_treesame_root_parents(commit);
3167                 if (marked)
3168                         marked -= leave_one_treesame_to_parent(revs, commit);
3169                 if (marked)
3170                         cnt = remove_marked_parents(revs, commit);
3171         }
3172
3173         /*
3174          * A commit simplifies to itself if it is a root, if it is
3175          * UNINTERESTING, if it touches the given paths, or if it is a
3176          * merge and its parents don't simplify to one relevant commit
3177          * (the first two cases are already handled at the beginning of
3178          * this function).
3179          *
3180          * Otherwise, it simplifies to what its sole relevant parent
3181          * simplifies to.
3182          */
3183         if (!cnt ||
3184             (commit->object.flags & UNINTERESTING) ||
3185             !(commit->object.flags & TREESAME) ||
3186             (parent = one_relevant_parent(revs, commit->parents)) == NULL ||
3187             (revs->show_pulls && (commit->object.flags & PULL_MERGE)))
3188                 st->simplified = commit;
3189         else {
3190                 pst = locate_simplify_state(revs, parent);
3191                 st->simplified = pst->simplified;
3192         }
3193         return tail;
3194 }
3195
3196 static void simplify_merges(struct rev_info *revs)
3197 {
3198         struct commit_list *list, *next;
3199         struct commit_list *yet_to_do, **tail;
3200         struct commit *commit;
3201
3202         if (!revs->prune)
3203                 return;
3204
3205         /* feed the list reversed */
3206         yet_to_do = NULL;
3207         for (list = revs->commits; list; list = next) {
3208                 commit = list->item;
3209                 next = list->next;
3210                 /*
3211                  * Do not free(list) here yet; the original list
3212                  * is used later in this function.
3213                  */
3214                 commit_list_insert(commit, &yet_to_do);
3215         }
3216         while (yet_to_do) {
3217                 list = yet_to_do;
3218                 yet_to_do = NULL;
3219                 tail = &yet_to_do;
3220                 while (list) {
3221                         commit = pop_commit(&list);
3222                         tail = simplify_one(revs, commit, tail);
3223                 }
3224         }
3225
3226         /* clean up the result, removing the simplified ones */
3227         list = revs->commits;
3228         revs->commits = NULL;
3229         tail = &revs->commits;
3230         while (list) {
3231                 struct merge_simplify_state *st;
3232
3233                 commit = pop_commit(&list);
3234                 st = locate_simplify_state(revs, commit);
3235                 if (st->simplified == commit)
3236                         tail = &commit_list_insert(commit, tail)->next;
3237         }
3238 }
3239
3240 static void set_children(struct rev_info *revs)
3241 {
3242         struct commit_list *l;
3243         for (l = revs->commits; l; l = l->next) {
3244                 struct commit *commit = l->item;
3245                 struct commit_list *p;
3246
3247                 for (p = commit->parents; p; p = p->next)
3248                         add_child(revs, p->item, commit);
3249         }
3250 }
3251
3252 void reset_revision_walk(void)
3253 {
3254         clear_object_flags(SEEN | ADDED | SHOWN | TOPO_WALK_EXPLORED | TOPO_WALK_INDEGREE);
3255 }
3256
3257 static int mark_uninteresting(const struct object_id *oid,
3258                               struct packed_git *pack,
3259                               uint32_t pos,
3260                               void *cb)
3261 {
3262         struct rev_info *revs = cb;
3263         struct object *o = parse_object(revs->repo, oid);
3264         o->flags |= UNINTERESTING | SEEN;
3265         return 0;
3266 }
3267
3268 define_commit_slab(indegree_slab, int);
3269 define_commit_slab(author_date_slab, timestamp_t);
3270
3271 struct topo_walk_info {
3272         uint32_t min_generation;
3273         struct prio_queue explore_queue;
3274         struct prio_queue indegree_queue;
3275         struct prio_queue topo_queue;
3276         struct indegree_slab indegree;
3277         struct author_date_slab author_date;
3278 };
3279
3280 static inline void test_flag_and_insert(struct prio_queue *q, struct commit *c, int flag)
3281 {
3282         if (c->object.flags & flag)
3283                 return;
3284
3285         c->object.flags |= flag;
3286         prio_queue_put(q, c);
3287 }
3288
3289 static void explore_walk_step(struct rev_info *revs)
3290 {
3291         struct topo_walk_info *info = revs->topo_walk_info;
3292         struct commit_list *p;
3293         struct commit *c = prio_queue_get(&info->explore_queue);
3294
3295         if (!c)
3296                 return;
3297
3298         if (parse_commit_gently(c, 1) < 0)
3299                 return;
3300
3301         if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
3302                 record_author_date(&info->author_date, c);
3303
3304         if (revs->max_age != -1 && (c->date < revs->max_age))
3305                 c->object.flags |= UNINTERESTING;
3306
3307         if (process_parents(revs, c, NULL, NULL) < 0)
3308                 return;
3309
3310         if (c->object.flags & UNINTERESTING)
3311                 mark_parents_uninteresting(c);
3312
3313         for (p = c->parents; p; p = p->next)
3314                 test_flag_and_insert(&info->explore_queue, p->item, TOPO_WALK_EXPLORED);
3315 }
3316
3317 static void explore_to_depth(struct rev_info *revs,
3318                              uint32_t gen_cutoff)
3319 {
3320         struct topo_walk_info *info = revs->topo_walk_info;
3321         struct commit *c;
3322         while ((c = prio_queue_peek(&info->explore_queue)) &&
3323                c->generation >= gen_cutoff)
3324                 explore_walk_step(revs);
3325 }
3326
3327 static void indegree_walk_step(struct rev_info *revs)
3328 {
3329         struct commit_list *p;
3330         struct topo_walk_info *info = revs->topo_walk_info;
3331         struct commit *c = prio_queue_get(&info->indegree_queue);
3332
3333         if (!c)
3334                 return;
3335
3336         if (parse_commit_gently(c, 1) < 0)
3337                 return;
3338
3339         explore_to_depth(revs, c->generation);
3340
3341         for (p = c->parents; p; p = p->next) {
3342                 struct commit *parent = p->item;
3343                 int *pi = indegree_slab_at(&info->indegree, parent);
3344
3345                 if (*pi)
3346                         (*pi)++;
3347                 else
3348                         *pi = 2;
3349
3350                 test_flag_and_insert(&info->indegree_queue, parent, TOPO_WALK_INDEGREE);
3351
3352                 if (revs->first_parent_only)
3353                         return;
3354         }
3355 }
3356
3357 static void compute_indegrees_to_depth(struct rev_info *revs,
3358                                        uint32_t gen_cutoff)
3359 {
3360         struct topo_walk_info *info = revs->topo_walk_info;
3361         struct commit *c;
3362         while ((c = prio_queue_peek(&info->indegree_queue)) &&
3363                c->generation >= gen_cutoff)
3364                 indegree_walk_step(revs);
3365 }
3366
3367 static void reset_topo_walk(struct rev_info *revs)
3368 {
3369         struct topo_walk_info *info = revs->topo_walk_info;
3370
3371         clear_prio_queue(&info->explore_queue);
3372         clear_prio_queue(&info->indegree_queue);
3373         clear_prio_queue(&info->topo_queue);
3374         clear_indegree_slab(&info->indegree);
3375         clear_author_date_slab(&info->author_date);
3376
3377         FREE_AND_NULL(revs->topo_walk_info);
3378 }
3379
3380 static void init_topo_walk(struct rev_info *revs)
3381 {
3382         struct topo_walk_info *info;
3383         struct commit_list *list;
3384         if (revs->topo_walk_info)
3385                 reset_topo_walk(revs);
3386
3387         revs->topo_walk_info = xmalloc(sizeof(struct topo_walk_info));
3388         info = revs->topo_walk_info;
3389         memset(info, 0, sizeof(struct topo_walk_info));
3390
3391         init_indegree_slab(&info->indegree);
3392         memset(&info->explore_queue, 0, sizeof(info->explore_queue));
3393         memset(&info->indegree_queue, 0, sizeof(info->indegree_queue));
3394         memset(&info->topo_queue, 0, sizeof(info->topo_queue));
3395
3396         switch (revs->sort_order) {
3397         default: /* REV_SORT_IN_GRAPH_ORDER */
3398                 info->topo_queue.compare = NULL;
3399                 break;
3400         case REV_SORT_BY_COMMIT_DATE:
3401                 info->topo_queue.compare = compare_commits_by_commit_date;
3402                 break;
3403         case REV_SORT_BY_AUTHOR_DATE:
3404                 init_author_date_slab(&info->author_date);
3405                 info->topo_queue.compare = compare_commits_by_author_date;
3406                 info->topo_queue.cb_data = &info->author_date;
3407                 break;
3408         }
3409
3410         info->explore_queue.compare = compare_commits_by_gen_then_commit_date;
3411         info->indegree_queue.compare = compare_commits_by_gen_then_commit_date;
3412
3413         info->min_generation = GENERATION_NUMBER_INFINITY;
3414         for (list = revs->commits; list; list = list->next) {
3415                 struct commit *c = list->item;
3416
3417                 if (parse_commit_gently(c, 1))
3418                         continue;
3419
3420                 test_flag_and_insert(&info->explore_queue, c, TOPO_WALK_EXPLORED);
3421                 test_flag_and_insert(&info->indegree_queue, c, TOPO_WALK_INDEGREE);
3422
3423                 if (c->generation < info->min_generation)
3424                         info->min_generation = c->generation;
3425
3426                 *(indegree_slab_at(&info->indegree, c)) = 1;
3427
3428                 if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
3429                         record_author_date(&info->author_date, c);
3430         }
3431         compute_indegrees_to_depth(revs, info->min_generation);
3432
3433         for (list = revs->commits; list; list = list->next) {
3434                 struct commit *c = list->item;
3435
3436                 if (*(indegree_slab_at(&info->indegree, c)) == 1)
3437                         prio_queue_put(&info->topo_queue, c);
3438         }
3439
3440         /*
3441          * This is unfortunate; the initial tips need to be shown
3442          * in the order given from the revision traversal machinery.
3443          */
3444         if (revs->sort_order == REV_SORT_IN_GRAPH_ORDER)
3445                 prio_queue_reverse(&info->topo_queue);
3446 }
3447
3448 static struct commit *next_topo_commit(struct rev_info *revs)
3449 {
3450         struct commit *c;
3451         struct topo_walk_info *info = revs->topo_walk_info;
3452
3453         /* pop next off of topo_queue */
3454         c = prio_queue_get(&info->topo_queue);
3455
3456         if (c)
3457                 *(indegree_slab_at(&info->indegree, c)) = 0;
3458
3459         return c;
3460 }
3461
3462 static void expand_topo_walk(struct rev_info *revs, struct commit *commit)
3463 {
3464         struct commit_list *p;
3465         struct topo_walk_info *info = revs->topo_walk_info;
3466         if (process_parents(revs, commit, NULL, NULL) < 0) {
3467                 if (!revs->ignore_missing_links)
3468                         die("Failed to traverse parents of commit %s",
3469                             oid_to_hex(&commit->object.oid));
3470         }
3471
3472         for (p = commit->parents; p; p = p->next) {
3473                 struct commit *parent = p->item;
3474                 int *pi;
3475
3476                 if (parent->object.flags & UNINTERESTING)
3477                         continue;
3478
3479                 if (parse_commit_gently(parent, 1) < 0)
3480                         continue;
3481
3482                 if (parent->generation < info->min_generation) {
3483                         info->min_generation = parent->generation;
3484                         compute_indegrees_to_depth(revs, info->min_generation);
3485                 }
3486
3487                 pi = indegree_slab_at(&info->indegree, parent);
3488
3489                 (*pi)--;
3490                 if (*pi == 1)
3491                         prio_queue_put(&info->topo_queue, parent);
3492
3493                 if (revs->first_parent_only)
3494                         return;
3495         }
3496 }
3497
3498 int prepare_revision_walk(struct rev_info *revs)
3499 {
3500         int i;
3501         struct object_array old_pending;
3502         struct commit_list **next = &revs->commits;
3503
3504         memcpy(&old_pending, &revs->pending, sizeof(old_pending));
3505         revs->pending.nr = 0;
3506         revs->pending.alloc = 0;
3507         revs->pending.objects = NULL;
3508         for (i = 0; i < old_pending.nr; i++) {
3509                 struct object_array_entry *e = old_pending.objects + i;
3510                 struct commit *commit = handle_commit(revs, e);
3511                 if (commit) {
3512                         if (!(commit->object.flags & SEEN)) {
3513                                 commit->object.flags |= SEEN;
3514                                 next = commit_list_append(commit, next);
3515                         }
3516                 }
3517         }
3518         object_array_clear(&old_pending);
3519
3520         /* Signal whether we need per-parent treesame decoration */
3521         if (revs->simplify_merges ||
3522             (revs->limited && limiting_can_increase_treesame(revs)))
3523                 revs->treesame.name = "treesame";
3524
3525         if (revs->exclude_promisor_objects) {
3526                 for_each_packed_object(mark_uninteresting, revs,
3527                                        FOR_EACH_OBJECT_PROMISOR_ONLY);
3528         }
3529
3530         if (!revs->reflog_info)
3531                 prepare_to_use_bloom_filter(revs);
3532         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
3533                 commit_list_sort_by_date(&revs->commits);
3534         if (revs->no_walk)
3535                 return 0;
3536         if (revs->limited) {
3537                 if (limit_list(revs) < 0)
3538                         return -1;
3539                 if (revs->topo_order)
3540                         sort_in_topological_order(&revs->commits, revs->sort_order);
3541         } else if (revs->topo_order)
3542                 init_topo_walk(revs);
3543         if (revs->line_level_traverse && want_ancestry(revs))
3544                 /*
3545                  * At the moment we can only do line-level log with parent
3546                  * rewriting by performing this expensive pre-filtering step.
3547                  * If parent rewriting is not requested, then we rather
3548                  * perform the line-level log filtering during the regular
3549                  * history traversal.
3550                  */
3551                 line_log_filter(revs);
3552         if (revs->simplify_merges)
3553                 simplify_merges(revs);
3554         if (revs->children.name)
3555                 set_children(revs);
3556
3557         return 0;
3558 }
3559
3560 static enum rewrite_result rewrite_one_1(struct rev_info *revs,
3561                                          struct commit **pp,
3562                                          struct prio_queue *queue)
3563 {
3564         for (;;) {
3565                 struct commit *p = *pp;
3566                 if (!revs->limited)
3567                         if (process_parents(revs, p, NULL, queue) < 0)
3568                                 return rewrite_one_error;
3569                 if (p->object.flags & UNINTERESTING)
3570                         return rewrite_one_ok;
3571                 if (!(p->object.flags & TREESAME))
3572                         return rewrite_one_ok;
3573                 if (!p->parents)
3574                         return rewrite_one_noparents;
3575                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
3576                         return rewrite_one_ok;
3577                 *pp = p;
3578         }
3579 }
3580
3581 static void merge_queue_into_list(struct prio_queue *q, struct commit_list **list)
3582 {
3583         while (q->nr) {
3584                 struct commit *item = prio_queue_peek(q);
3585                 struct commit_list *p = *list;
3586
3587                 if (p && p->item->date >= item->date)
3588                         list = &p->next;
3589                 else {
3590                         p = commit_list_insert(item, list);
3591                         list = &p->next; /* skip newly added item */
3592                         prio_queue_get(q); /* pop item */
3593                 }
3594         }
3595 }
3596
3597 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
3598 {
3599         struct prio_queue queue = { compare_commits_by_commit_date };
3600         enum rewrite_result ret = rewrite_one_1(revs, pp, &queue);
3601         merge_queue_into_list(&queue, &revs->commits);
3602         clear_prio_queue(&queue);
3603         return ret;
3604 }
3605
3606 int rewrite_parents(struct rev_info *revs, struct commit *commit,
3607         rewrite_parent_fn_t rewrite_parent)
3608 {
3609         struct commit_list **pp = &commit->parents;
3610         while (*pp) {
3611                 struct commit_list *parent = *pp;
3612                 switch (rewrite_parent(revs, &parent->item)) {
3613                 case rewrite_one_ok:
3614                         break;
3615                 case rewrite_one_noparents:
3616                         *pp = parent->next;
3617                         continue;
3618                 case rewrite_one_error:
3619                         return -1;
3620                 }
3621                 pp = &parent->next;
3622         }
3623         remove_duplicate_parents(revs, commit);
3624         return 0;
3625 }
3626
3627 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
3628 {
3629         char *person, *endp;
3630         size_t len, namelen, maillen;
3631         const char *name;
3632         const char *mail;
3633         struct ident_split ident;
3634
3635         person = strstr(buf->buf, what);
3636         if (!person)
3637                 return 0;
3638
3639         person += strlen(what);
3640         endp = strchr(person, '\n');
3641         if (!endp)
3642                 return 0;
3643
3644         len = endp - person;
3645
3646         if (split_ident_line(&ident, person, len))
3647                 return 0;
3648
3649         mail = ident.mail_begin;
3650         maillen = ident.mail_end - ident.mail_begin;
3651         name = ident.name_begin;
3652         namelen = ident.name_end - ident.name_begin;
3653
3654         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
3655                 struct strbuf namemail = STRBUF_INIT;
3656
3657                 strbuf_addf(&namemail, "%.*s <%.*s>",
3658                             (int)namelen, name, (int)maillen, mail);
3659
3660                 strbuf_splice(buf, ident.name_begin - buf->buf,
3661                               ident.mail_end - ident.name_begin + 1,
3662                               namemail.buf, namemail.len);
3663
3664                 strbuf_release(&namemail);
3665
3666                 return 1;
3667         }
3668
3669         return 0;
3670 }
3671
3672 static int commit_match(struct commit *commit, struct rev_info *opt)
3673 {
3674         int retval;
3675         const char *encoding;
3676         const char *message;
3677         struct strbuf buf = STRBUF_INIT;
3678
3679         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
3680                 return 1;
3681
3682         /* Prepend "fake" headers as needed */
3683         if (opt->grep_filter.use_reflog_filter) {
3684                 strbuf_addstr(&buf, "reflog ");
3685                 get_reflog_message(&buf, opt->reflog_info);
3686                 strbuf_addch(&buf, '\n');
3687         }
3688
3689         /*
3690          * We grep in the user's output encoding, under the assumption that it
3691          * is the encoding they are most likely to write their grep pattern
3692          * for. In addition, it means we will match the "notes" encoding below,
3693          * so we will not end up with a buffer that has two different encodings
3694          * in it.
3695          */
3696         encoding = get_log_output_encoding();
3697         message = logmsg_reencode(commit, NULL, encoding);
3698
3699         /* Copy the commit to temporary if we are using "fake" headers */
3700         if (buf.len)
3701                 strbuf_addstr(&buf, message);
3702
3703         if (opt->grep_filter.header_list && opt->mailmap) {
3704                 if (!buf.len)
3705                         strbuf_addstr(&buf, message);
3706
3707                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
3708                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
3709         }
3710
3711         /* Append "fake" message parts as needed */
3712         if (opt->show_notes) {
3713                 if (!buf.len)
3714                         strbuf_addstr(&buf, message);
3715                 format_display_notes(&commit->object.oid, &buf, encoding, 1);
3716         }
3717
3718         /*
3719          * Find either in the original commit message, or in the temporary.
3720          * Note that we cast away the constness of "message" here. It is
3721          * const because it may come from the cached commit buffer. That's OK,
3722          * because we know that it is modifiable heap memory, and that while
3723          * grep_buffer may modify it for speed, it will restore any
3724          * changes before returning.
3725          */
3726         if (buf.len)
3727                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
3728         else
3729                 retval = grep_buffer(&opt->grep_filter,
3730                                      (char *)message, strlen(message));
3731         strbuf_release(&buf);
3732         unuse_commit_buffer(commit, message);
3733         return opt->invert_grep ? !retval : retval;
3734 }
3735
3736 static inline int want_ancestry(const struct rev_info *revs)
3737 {
3738         return (revs->rewrite_parents || revs->children.name);
3739 }
3740
3741 /*
3742  * Return a timestamp to be used for --since/--until comparisons for this
3743  * commit, based on the revision options.
3744  */
3745 static timestamp_t comparison_date(const struct rev_info *revs,
3746                                    struct commit *commit)
3747 {
3748         return revs->reflog_info ?
3749                 get_reflog_timestamp(revs->reflog_info) :
3750                 commit->date;
3751 }
3752
3753 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
3754 {
3755         if (commit->object.flags & SHOWN)
3756                 return commit_ignore;
3757         if (revs->unpacked && has_object_pack(&commit->object.oid))
3758                 return commit_ignore;
3759         if (commit->object.flags & UNINTERESTING)
3760                 return commit_ignore;
3761         if (revs->line_level_traverse && !want_ancestry(revs)) {
3762                 /*
3763                  * In case of line-level log with parent rewriting
3764                  * prepare_revision_walk() already took care of all line-level
3765                  * log filtering, and there is nothing left to do here.
3766                  *
3767                  * If parent rewriting was not requested, then this is the
3768                  * place to perform the line-level log filtering.  Notably,
3769                  * this check, though expensive, must come before the other,
3770                  * cheaper filtering conditions, because the tracked line
3771                  * ranges must be adjusted even when the commit will end up
3772                  * being ignored based on other conditions.
3773                  */
3774                 if (!line_log_process_ranges_arbitrary_commit(revs, commit))
3775                         return commit_ignore;
3776         }
3777         if (revs->min_age != -1 &&
3778             comparison_date(revs, commit) > revs->min_age)
3779                         return commit_ignore;
3780         if (revs->min_parents || (revs->max_parents >= 0)) {
3781                 int n = commit_list_count(commit->parents);
3782                 if ((n < revs->min_parents) ||
3783                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
3784                         return commit_ignore;
3785         }
3786         if (!commit_match(commit, revs))
3787                 return commit_ignore;
3788         if (revs->prune && revs->dense) {
3789                 /* Commit without changes? */
3790                 if (commit->object.flags & TREESAME) {
3791                         int n;
3792                         struct commit_list *p;
3793                         /* drop merges unless we want parenthood */
3794                         if (!want_ancestry(revs))
3795                                 return commit_ignore;
3796
3797                         if (revs->show_pulls && (commit->object.flags & PULL_MERGE))
3798                                 return commit_show;
3799
3800                         /*
3801                          * If we want ancestry, then need to keep any merges
3802                          * between relevant commits to tie together topology.
3803                          * For consistency with TREESAME and simplification
3804                          * use "relevant" here rather than just INTERESTING,
3805                          * to treat bottom commit(s) as part of the topology.
3806                          */
3807                         for (n = 0, p = commit->parents; p; p = p->next)
3808                                 if (relevant_commit(p->item))
3809                                         if (++n >= 2)
3810                                                 return commit_show;
3811                         return commit_ignore;
3812                 }
3813         }
3814         return commit_show;
3815 }
3816
3817 define_commit_slab(saved_parents, struct commit_list *);
3818
3819 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3820
3821 /*
3822  * You may only call save_parents() once per commit (this is checked
3823  * for non-root commits).
3824  */
3825 static void save_parents(struct rev_info *revs, struct commit *commit)
3826 {
3827         struct commit_list **pp;
3828
3829         if (!revs->saved_parents_slab) {
3830                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3831                 init_saved_parents(revs->saved_parents_slab);
3832         }
3833
3834         pp = saved_parents_at(revs->saved_parents_slab, commit);
3835
3836         /*
3837          * When walking with reflogs, we may visit the same commit
3838          * several times: once for each appearance in the reflog.
3839          *
3840          * In this case, save_parents() will be called multiple times.
3841          * We want to keep only the first set of parents.  We need to
3842          * store a sentinel value for an empty (i.e., NULL) parent
3843          * list to distinguish it from a not-yet-saved list, however.
3844          */
3845         if (*pp)
3846                 return;
3847         if (commit->parents)
3848                 *pp = copy_commit_list(commit->parents);
3849         else
3850                 *pp = EMPTY_PARENT_LIST;
3851 }
3852
3853 static void free_saved_parents(struct rev_info *revs)
3854 {
3855         if (revs->saved_parents_slab)
3856                 clear_saved_parents(revs->saved_parents_slab);
3857 }
3858
3859 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3860 {
3861         struct commit_list *parents;
3862
3863         if (!revs->saved_parents_slab)
3864                 return commit->parents;
3865
3866         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3867         if (parents == EMPTY_PARENT_LIST)
3868                 return NULL;
3869         return parents;
3870 }
3871
3872 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3873 {
3874         enum commit_action action = get_commit_action(revs, commit);
3875
3876         if (action == commit_show &&
3877             revs->prune && revs->dense && want_ancestry(revs)) {
3878                 /*
3879                  * --full-diff on simplified parents is no good: it
3880                  * will show spurious changes from the commits that
3881                  * were elided.  So we save the parents on the side
3882                  * when --full-diff is in effect.
3883                  */
3884                 if (revs->full_diff)
3885                         save_parents(revs, commit);
3886                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
3887                         return commit_error;
3888         }
3889         return action;
3890 }
3891
3892 static void track_linear(struct rev_info *revs, struct commit *commit)
3893 {
3894         if (revs->track_first_time) {
3895                 revs->linear = 1;
3896                 revs->track_first_time = 0;
3897         } else {
3898                 struct commit_list *p;
3899                 for (p = revs->previous_parents; p; p = p->next)
3900                         if (p->item == NULL || /* first commit */
3901                             oideq(&p->item->object.oid, &commit->object.oid))
3902                                 break;
3903                 revs->linear = p != NULL;
3904         }
3905         if (revs->reverse) {
3906                 if (revs->linear)
3907                         commit->object.flags |= TRACK_LINEAR;
3908         }
3909         free_commit_list(revs->previous_parents);
3910         revs->previous_parents = copy_commit_list(commit->parents);
3911 }
3912
3913 static struct commit *get_revision_1(struct rev_info *revs)
3914 {
3915         while (1) {
3916                 struct commit *commit;
3917
3918                 if (revs->reflog_info)
3919                         commit = next_reflog_entry(revs->reflog_info);
3920                 else if (revs->topo_walk_info)
3921                         commit = next_topo_commit(revs);
3922                 else
3923                         commit = pop_commit(&revs->commits);
3924
3925                 if (!commit)
3926                         return NULL;
3927
3928                 if (revs->reflog_info)
3929                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3930
3931                 /*
3932                  * If we haven't done the list limiting, we need to look at
3933                  * the parents here. We also need to do the date-based limiting
3934                  * that we'd otherwise have done in limit_list().
3935                  */
3936                 if (!revs->limited) {
3937                         if (revs->max_age != -1 &&
3938                             comparison_date(revs, commit) < revs->max_age)
3939                                 continue;
3940
3941                         if (revs->reflog_info)
3942                                 try_to_simplify_commit(revs, commit);
3943                         else if (revs->topo_walk_info)
3944                                 expand_topo_walk(revs, commit);
3945                         else if (process_parents(revs, commit, &revs->commits, NULL) < 0) {
3946                                 if (!revs->ignore_missing_links)
3947                                         die("Failed to traverse parents of commit %s",
3948                                                 oid_to_hex(&commit->object.oid));
3949                         }
3950                 }
3951
3952                 switch (simplify_commit(revs, commit)) {
3953                 case commit_ignore:
3954                         continue;
3955                 case commit_error:
3956                         die("Failed to simplify parents of commit %s",
3957                             oid_to_hex(&commit->object.oid));
3958                 default:
3959                         if (revs->track_linear)
3960                                 track_linear(revs, commit);
3961                         return commit;
3962                 }
3963         }
3964 }
3965
3966 /*
3967  * Return true for entries that have not yet been shown.  (This is an
3968  * object_array_each_func_t.)
3969  */
3970 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3971 {
3972         return !(entry->item->flags & SHOWN);
3973 }
3974
3975 /*
3976  * If array is on the verge of a realloc, garbage-collect any entries
3977  * that have already been shown to try to free up some space.
3978  */
3979 static void gc_boundary(struct object_array *array)
3980 {
3981         if (array->nr == array->alloc)
3982                 object_array_filter(array, entry_unshown, NULL);
3983 }
3984
3985 static void create_boundary_commit_list(struct rev_info *revs)
3986 {
3987         unsigned i;
3988         struct commit *c;
3989         struct object_array *array = &revs->boundary_commits;
3990         struct object_array_entry *objects = array->objects;
3991
3992         /*
3993          * If revs->commits is non-NULL at this point, an error occurred in
3994          * get_revision_1().  Ignore the error and continue printing the
3995          * boundary commits anyway.  (This is what the code has always
3996          * done.)
3997          */
3998         if (revs->commits) {
3999                 free_commit_list(revs->commits);
4000                 revs->commits = NULL;
4001         }
4002
4003         /*
4004          * Put all of the actual boundary commits from revs->boundary_commits
4005          * into revs->commits
4006          */
4007         for (i = 0; i < array->nr; i++) {
4008                 c = (struct commit *)(objects[i].item);
4009                 if (!c)
4010                         continue;
4011                 if (!(c->object.flags & CHILD_SHOWN))
4012                         continue;
4013                 if (c->object.flags & (SHOWN | BOUNDARY))
4014                         continue;
4015                 c->object.flags |= BOUNDARY;
4016                 commit_list_insert(c, &revs->commits);
4017         }
4018
4019         /*
4020          * If revs->topo_order is set, sort the boundary commits
4021          * in topological order
4022          */
4023         sort_in_topological_order(&revs->commits, revs->sort_order);
4024 }
4025
4026 static struct commit *get_revision_internal(struct rev_info *revs)
4027 {
4028         struct commit *c = NULL;
4029         struct commit_list *l;
4030
4031         if (revs->boundary == 2) {
4032                 /*
4033                  * All of the normal commits have already been returned,
4034                  * and we are now returning boundary commits.
4035                  * create_boundary_commit_list() has populated
4036                  * revs->commits with the remaining commits to return.
4037                  */
4038                 c = pop_commit(&revs->commits);
4039                 if (c)
4040                         c->object.flags |= SHOWN;
4041                 return c;
4042         }
4043
4044         /*
4045          * If our max_count counter has reached zero, then we are done. We
4046          * don't simply return NULL because we still might need to show
4047          * boundary commits. But we want to avoid calling get_revision_1, which
4048          * might do a considerable amount of work finding the next commit only
4049          * for us to throw it away.
4050          *
4051          * If it is non-zero, then either we don't have a max_count at all
4052          * (-1), or it is still counting, in which case we decrement.
4053          */
4054         if (revs->max_count) {
4055                 c = get_revision_1(revs);
4056                 if (c) {
4057                         while (revs->skip_count > 0) {
4058                                 revs->skip_count--;
4059                                 c = get_revision_1(revs);
4060                                 if (!c)
4061                                         break;
4062                         }
4063                 }
4064
4065                 if (revs->max_count > 0)
4066                         revs->max_count--;
4067         }
4068
4069         if (c)
4070                 c->object.flags |= SHOWN;
4071
4072         if (!revs->boundary)
4073                 return c;
4074
4075         if (!c) {
4076                 /*
4077                  * get_revision_1() runs out the commits, and
4078                  * we are done computing the boundaries.
4079                  * switch to boundary commits output mode.
4080                  */
4081                 revs->boundary = 2;
4082
4083                 /*
4084                  * Update revs->commits to contain the list of
4085                  * boundary commits.
4086                  */
4087                 create_boundary_commit_list(revs);
4088
4089                 return get_revision_internal(revs);
4090         }
4091
4092         /*
4093          * boundary commits are the commits that are parents of the
4094          * ones we got from get_revision_1() but they themselves are
4095          * not returned from get_revision_1().  Before returning
4096          * 'c', we need to mark its parents that they could be boundaries.
4097          */
4098
4099         for (l = c->parents; l; l = l->next) {
4100                 struct object *p;
4101                 p = &(l->item->object);
4102                 if (p->flags & (CHILD_SHOWN | SHOWN))
4103                         continue;
4104                 p->flags |= CHILD_SHOWN;
4105                 gc_boundary(&revs->boundary_commits);
4106                 add_object_array(p, NULL, &revs->boundary_commits);
4107         }
4108
4109         return c;
4110 }
4111
4112 struct commit *get_revision(struct rev_info *revs)
4113 {
4114         struct commit *c;
4115         struct commit_list *reversed;
4116
4117         if (revs->reverse) {
4118                 reversed = NULL;
4119                 while ((c = get_revision_internal(revs)))
4120                         commit_list_insert(c, &reversed);
4121                 revs->commits = reversed;
4122                 revs->reverse = 0;
4123                 revs->reverse_output_stage = 1;
4124         }
4125
4126         if (revs->reverse_output_stage) {
4127                 c = pop_commit(&revs->commits);
4128                 if (revs->track_linear)
4129                         revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
4130                 return c;
4131         }
4132
4133         c = get_revision_internal(revs);
4134         if (c && revs->graph)
4135                 graph_update(revs->graph, c);
4136         if (!c) {
4137                 free_saved_parents(revs);
4138                 if (revs->previous_parents) {
4139                         free_commit_list(revs->previous_parents);
4140                         revs->previous_parents = NULL;
4141                 }
4142         }
4143         return c;
4144 }
4145
4146 const char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
4147 {
4148         if (commit->object.flags & BOUNDARY)
4149                 return "-";
4150         else if (commit->object.flags & UNINTERESTING)
4151                 return "^";
4152         else if (commit->object.flags & PATCHSAME)
4153                 return "=";
4154         else if (!revs || revs->left_right) {
4155                 if (commit->object.flags & SYMMETRIC_LEFT)
4156                         return "<";
4157                 else
4158                         return ">";
4159         } else if (revs->graph)
4160                 return "*";
4161         else if (revs->cherry_mark)
4162                 return "+";
4163         return "";
4164 }
4165
4166 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
4167 {
4168         const char *mark = get_revision_mark(revs, commit);
4169         if (!strlen(mark))
4170                 return;
4171         fputs(mark, stdout);
4172         putchar(' ');
4173 }