Merge branch 'jc/show-branch-dense'
[git] / revision.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "refs.h"
8 #include "revision.h"
9
10 static char *path_name(struct name_path *path, const char *name)
11 {
12         struct name_path *p;
13         char *n, *m;
14         int nlen = strlen(name);
15         int len = nlen + 1;
16
17         for (p = path; p; p = p->up) {
18                 if (p->elem_len)
19                         len += p->elem_len + 1;
20         }
21         n = xmalloc(len);
22         m = n + len - (nlen + 1);
23         strcpy(m, name);
24         for (p = path; p; p = p->up) {
25                 if (p->elem_len) {
26                         m -= p->elem_len + 1;
27                         memcpy(m, p->elem, p->elem_len);
28                         m[p->elem_len] = '/';
29                 }
30         }
31         return n;
32 }
33
34 struct object_list **add_object(struct object *obj,
35                                        struct object_list **p,
36                                        struct name_path *path,
37                                        const char *name)
38 {
39         struct object_list *entry = xmalloc(sizeof(*entry));
40         entry->item = obj;
41         entry->next = *p;
42         entry->name = path_name(path, name);
43         *p = entry;
44         return &entry->next;
45 }
46
47 static void mark_blob_uninteresting(struct blob *blob)
48 {
49         if (blob->object.flags & UNINTERESTING)
50                 return;
51         blob->object.flags |= UNINTERESTING;
52 }
53
54 void mark_tree_uninteresting(struct tree *tree)
55 {
56         struct object *obj = &tree->object;
57         struct tree_entry_list *entry;
58
59         if (obj->flags & UNINTERESTING)
60                 return;
61         obj->flags |= UNINTERESTING;
62         if (!has_sha1_file(obj->sha1))
63                 return;
64         if (parse_tree(tree) < 0)
65                 die("bad tree %s", sha1_to_hex(obj->sha1));
66         entry = tree->entries;
67         tree->entries = NULL;
68         while (entry) {
69                 struct tree_entry_list *next = entry->next;
70                 if (entry->directory)
71                         mark_tree_uninteresting(entry->item.tree);
72                 else
73                         mark_blob_uninteresting(entry->item.blob);
74                 free(entry);
75                 entry = next;
76         }
77 }
78
79 void mark_parents_uninteresting(struct commit *commit)
80 {
81         struct commit_list *parents = commit->parents;
82
83         while (parents) {
84                 struct commit *commit = parents->item;
85                 if (!(commit->object.flags & UNINTERESTING)) {
86                         commit->object.flags |= UNINTERESTING;
87
88                         /*
89                          * Normally we haven't parsed the parent
90                          * yet, so we won't have a parent of a parent
91                          * here. However, it may turn out that we've
92                          * reached this commit some other way (where it
93                          * wasn't uninteresting), in which case we need
94                          * to mark its parents recursively too..
95                          */
96                         if (commit->parents)
97                                 mark_parents_uninteresting(commit);
98                 }
99
100                 /*
101                  * A missing commit is ok iff its parent is marked
102                  * uninteresting.
103                  *
104                  * We just mark such a thing parsed, so that when
105                  * it is popped next time around, we won't be trying
106                  * to parse it and get an error.
107                  */
108                 if (!has_sha1_file(commit->object.sha1))
109                         commit->object.parsed = 1;
110                 parents = parents->next;
111         }
112 }
113
114 static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
115 {
116         add_object(obj, &revs->pending_objects, NULL, name);
117 }
118
119 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
120 {
121         struct object *object;
122
123         object = parse_object(sha1);
124         if (!object)
125                 die("bad object %s", name);
126         object->flags |= flags;
127         return object;
128 }
129
130 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
131 {
132         unsigned long flags = object->flags;
133
134         /*
135          * Tag object? Look what it points to..
136          */
137         while (object->type == tag_type) {
138                 struct tag *tag = (struct tag *) object;
139                 if (revs->tag_objects && !(flags & UNINTERESTING))
140                         add_pending_object(revs, object, tag->tag);
141                 object = parse_object(tag->tagged->sha1);
142                 if (!object)
143                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
144         }
145
146         /*
147          * Commit object? Just return it, we'll do all the complex
148          * reachability crud.
149          */
150         if (object->type == commit_type) {
151                 struct commit *commit = (struct commit *)object;
152                 if (parse_commit(commit) < 0)
153                         die("unable to parse commit %s", name);
154                 if (flags & UNINTERESTING) {
155                         commit->object.flags |= UNINTERESTING;
156                         mark_parents_uninteresting(commit);
157                         revs->limited = 1;
158                 }
159                 return commit;
160         }
161
162         /*
163          * Tree object? Either mark it uniniteresting, or add it
164          * to the list of objects to look at later..
165          */
166         if (object->type == tree_type) {
167                 struct tree *tree = (struct tree *)object;
168                 if (!revs->tree_objects)
169                         return NULL;
170                 if (flags & UNINTERESTING) {
171                         mark_tree_uninteresting(tree);
172                         return NULL;
173                 }
174                 add_pending_object(revs, object, "");
175                 return NULL;
176         }
177
178         /*
179          * Blob object? You know the drill by now..
180          */
181         if (object->type == blob_type) {
182                 struct blob *blob = (struct blob *)object;
183                 if (!revs->blob_objects)
184                         return NULL;
185                 if (flags & UNINTERESTING) {
186                         mark_blob_uninteresting(blob);
187                         return NULL;
188                 }
189                 add_pending_object(revs, object, "");
190                 return NULL;
191         }
192         die("%s is unknown object", name);
193 }
194
195 static int everybody_uninteresting(struct commit_list *orig)
196 {
197         struct commit_list *list = orig;
198         while (list) {
199                 struct commit *commit = list->item;
200                 list = list->next;
201                 if (commit->object.flags & UNINTERESTING)
202                         continue;
203                 return 0;
204         }
205         return 1;
206 }
207
208 static int tree_difference = REV_TREE_SAME;
209
210 static void file_add_remove(struct diff_options *options,
211                     int addremove, unsigned mode,
212                     const unsigned char *sha1,
213                     const char *base, const char *path)
214 {
215         int diff = REV_TREE_DIFFERENT;
216
217         /*
218          * Is it an add of a new file? It means that the old tree
219          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
220          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
221          * (and if it already was "REV_TREE_NEW", we'll keep it
222          * "REV_TREE_NEW" of course).
223          */
224         if (addremove == '+') {
225                 diff = tree_difference;
226                 if (diff != REV_TREE_SAME)
227                         return;
228                 diff = REV_TREE_NEW;
229         }
230         tree_difference = diff;
231 }
232
233 static void file_change(struct diff_options *options,
234                  unsigned old_mode, unsigned new_mode,
235                  const unsigned char *old_sha1,
236                  const unsigned char *new_sha1,
237                  const char *base, const char *path)
238 {
239         tree_difference = REV_TREE_DIFFERENT;
240 }
241
242 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
243 {
244         if (!t1)
245                 return REV_TREE_NEW;
246         if (!t2)
247                 return REV_TREE_DIFFERENT;
248         tree_difference = REV_TREE_SAME;
249         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
250                            &revs->pruning) < 0)
251                 return REV_TREE_DIFFERENT;
252         return tree_difference;
253 }
254
255 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
256 {
257         int retval;
258         void *tree;
259         struct tree_desc empty, real;
260
261         if (!t1)
262                 return 0;
263
264         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
265         if (!tree)
266                 return 0;
267         real.buf = tree;
268
269         empty.buf = "";
270         empty.size = 0;
271
272         tree_difference = 0;
273         retval = diff_tree(&empty, &real, "", &revs->pruning);
274         free(tree);
275
276         return retval >= 0 && !tree_difference;
277 }
278
279 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
280 {
281         struct commit_list **pp, *parent;
282         int tree_changed = 0;
283
284         if (!commit->tree)
285                 return;
286
287         if (!commit->parents) {
288                 if (!rev_same_tree_as_empty(revs, commit->tree))
289                         commit->object.flags |= TREECHANGE;
290                 return;
291         }
292
293         pp = &commit->parents;
294         while ((parent = *pp) != NULL) {
295                 struct commit *p = parent->item;
296
297                 parse_commit(p);
298                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
299                 case REV_TREE_SAME:
300                         if (p->object.flags & UNINTERESTING) {
301                                 /* Even if a merge with an uninteresting
302                                  * side branch brought the entire change
303                                  * we are interested in, we do not want
304                                  * to lose the other branches of this
305                                  * merge, so we just keep going.
306                                  */
307                                 pp = &parent->next;
308                                 continue;
309                         }
310                         parent->next = NULL;
311                         commit->parents = parent;
312                         return;
313
314                 case REV_TREE_NEW:
315                         if (revs->remove_empty_trees &&
316                             rev_same_tree_as_empty(revs, p->tree)) {
317                                 /* We are adding all the specified
318                                  * paths from this parent, so the
319                                  * history beyond this parent is not
320                                  * interesting.  Remove its parents
321                                  * (they are grandparents for us).
322                                  * IOW, we pretend this parent is a
323                                  * "root" commit.
324                                  */
325                                 parse_commit(p);
326                                 p->parents = NULL;
327                         }
328                 /* fallthrough */
329                 case REV_TREE_DIFFERENT:
330                         tree_changed = 1;
331                         pp = &parent->next;
332                         continue;
333                 }
334                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
335         }
336         if (tree_changed)
337                 commit->object.flags |= TREECHANGE;
338 }
339
340 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
341 {
342         struct commit_list *parent = commit->parents;
343
344         if (commit->object.flags & ADDED)
345                 return;
346         commit->object.flags |= ADDED;
347
348         /*
349          * If the commit is uninteresting, don't try to
350          * prune parents - we want the maximal uninteresting
351          * set.
352          *
353          * Normally we haven't parsed the parent
354          * yet, so we won't have a parent of a parent
355          * here. However, it may turn out that we've
356          * reached this commit some other way (where it
357          * wasn't uninteresting), in which case we need
358          * to mark its parents recursively too..
359          */
360         if (commit->object.flags & UNINTERESTING) {
361                 while (parent) {
362                         struct commit *p = parent->item;
363                         parent = parent->next;
364                         parse_commit(p);
365                         p->object.flags |= UNINTERESTING;
366                         if (p->parents)
367                                 mark_parents_uninteresting(p);
368                         if (p->object.flags & SEEN)
369                                 continue;
370                         p->object.flags |= SEEN;
371                         insert_by_date(p, list);
372                 }
373                 return;
374         }
375
376         /*
377          * Ok, the commit wasn't uninteresting. Try to
378          * simplify the commit history and find the parent
379          * that has no differences in the path set if one exists.
380          */
381         if (revs->prune_fn)
382                 revs->prune_fn(revs, commit);
383
384         if (revs->no_walk)
385                 return;
386
387         parent = commit->parents;
388         while (parent) {
389                 struct commit *p = parent->item;
390
391                 parent = parent->next;
392
393                 parse_commit(p);
394                 if (p->object.flags & SEEN)
395                         continue;
396                 p->object.flags |= SEEN;
397                 insert_by_date(p, list);
398         }
399 }
400
401 static void limit_list(struct rev_info *revs)
402 {
403         struct commit_list *list = revs->commits;
404         struct commit_list *newlist = NULL;
405         struct commit_list **p = &newlist;
406
407         while (list) {
408                 struct commit_list *entry = list;
409                 struct commit *commit = list->item;
410                 struct object *obj = &commit->object;
411
412                 list = list->next;
413                 free(entry);
414
415                 if (revs->max_age != -1 && (commit->date < revs->max_age))
416                         obj->flags |= UNINTERESTING;
417                 if (revs->unpacked && has_sha1_pack(obj->sha1))
418                         obj->flags |= UNINTERESTING;
419                 add_parents_to_list(revs, commit, &list);
420                 if (obj->flags & UNINTERESTING) {
421                         mark_parents_uninteresting(commit);
422                         if (everybody_uninteresting(list))
423                                 break;
424                         continue;
425                 }
426                 if (revs->min_age != -1 && (commit->date > revs->min_age))
427                         continue;
428                 p = &commit_list_insert(commit, p)->next;
429         }
430         if (revs->boundary) {
431                 /* mark the ones that are on the result list first */
432                 for (list = newlist; list; list = list->next) {
433                         struct commit *commit = list->item;
434                         commit->object.flags |= TMP_MARK;
435                 }
436                 for (list = newlist; list; list = list->next) {
437                         struct commit *commit = list->item;
438                         struct object *obj = &commit->object;
439                         struct commit_list *parent;
440                         if (obj->flags & UNINTERESTING)
441                                 continue;
442                         for (parent = commit->parents;
443                              parent;
444                              parent = parent->next) {
445                                 struct commit *pcommit = parent->item;
446                                 if (!(pcommit->object.flags & UNINTERESTING))
447                                         continue;
448                                 pcommit->object.flags |= BOUNDARY;
449                                 if (pcommit->object.flags & TMP_MARK)
450                                         continue;
451                                 pcommit->object.flags |= TMP_MARK;
452                                 p = &commit_list_insert(pcommit, p)->next;
453                         }
454                 }
455                 for (list = newlist; list; list = list->next) {
456                         struct commit *commit = list->item;
457                         commit->object.flags &= ~TMP_MARK;
458                 }
459         }
460         revs->commits = newlist;
461 }
462
463 static int all_flags;
464 static struct rev_info *all_revs;
465
466 static int handle_one_ref(const char *path, const unsigned char *sha1)
467 {
468         struct object *object = get_reference(all_revs, path, sha1, all_flags);
469         add_pending_object(all_revs, object, "");
470         return 0;
471 }
472
473 static void handle_all(struct rev_info *revs, unsigned flags)
474 {
475         all_revs = revs;
476         all_flags = flags;
477         for_each_ref(handle_one_ref);
478 }
479
480 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
481 {
482         unsigned char sha1[20];
483         struct object *it;
484         struct commit *commit;
485         struct commit_list *parents;
486
487         if (*arg == '^') {
488                 flags ^= UNINTERESTING;
489                 arg++;
490         }
491         if (get_sha1(arg, sha1))
492                 return 0;
493         while (1) {
494                 it = get_reference(revs, arg, sha1, 0);
495                 if (strcmp(it->type, tag_type))
496                         break;
497                 memcpy(sha1, ((struct tag*)it)->tagged->sha1, 20);
498         }
499         if (strcmp(it->type, commit_type))
500                 return 0;
501         commit = (struct commit *)it;
502         for (parents = commit->parents; parents; parents = parents->next) {
503                 it = &parents->item->object;
504                 it->flags |= flags;
505                 add_pending_object(revs, it, arg);
506         }
507         return 1;
508 }
509
510 void init_revisions(struct rev_info *revs)
511 {
512         memset(revs, 0, sizeof(*revs));
513
514         revs->abbrev = DEFAULT_ABBREV;
515         revs->ignore_merges = 1;
516         revs->pruning.recursive = 1;
517         revs->pruning.add_remove = file_add_remove;
518         revs->pruning.change = file_change;
519         revs->lifo = 1;
520         revs->dense = 1;
521         revs->prefix = setup_git_directory();
522         revs->max_age = -1;
523         revs->min_age = -1;
524         revs->max_count = -1;
525
526         revs->prune_fn = NULL;
527         revs->prune_data = NULL;
528
529         revs->topo_setter = topo_sort_default_setter;
530         revs->topo_getter = topo_sort_default_getter;
531
532         revs->commit_format = CMIT_FMT_DEFAULT;
533
534         diff_setup(&revs->diffopt);
535 }
536
537 /*
538  * Parse revision information, filling in the "rev_info" structure,
539  * and removing the used arguments from the argument list.
540  *
541  * Returns the number of arguments left that weren't recognized
542  * (which are also moved to the head of the argument list)
543  */
544 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
545 {
546         int i, flags, seen_dashdash;
547         const char **unrecognized = argv + 1;
548         int left = 1;
549
550         /* First, search for "--" */
551         seen_dashdash = 0;
552         for (i = 1; i < argc; i++) {
553                 const char *arg = argv[i];
554                 if (strcmp(arg, "--"))
555                         continue;
556                 argv[i] = NULL;
557                 argc = i;
558                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
559                 seen_dashdash = 1;
560                 break;
561         }
562
563         flags = 0;
564         for (i = 1; i < argc; i++) {
565                 struct object *object;
566                 const char *arg = argv[i];
567                 unsigned char sha1[20];
568                 char *dotdot;
569                 int local_flags;
570
571                 if (*arg == '-') {
572                         int opts;
573                         if (!strncmp(arg, "--max-count=", 12)) {
574                                 revs->max_count = atoi(arg + 12);
575                                 continue;
576                         }
577                         /* accept -<digit>, like traditional "head" */
578                         if ((*arg == '-') && isdigit(arg[1])) {
579                                 revs->max_count = atoi(arg + 1);
580                                 continue;
581                         }
582                         if (!strcmp(arg, "-n")) {
583                                 if (argc <= i + 1)
584                                         die("-n requires an argument");
585                                 revs->max_count = atoi(argv[++i]);
586                                 continue;
587                         }
588                         if (!strncmp(arg,"-n",2)) {
589                                 revs->max_count = atoi(arg + 2);
590                                 continue;
591                         }
592                         if (!strncmp(arg, "--max-age=", 10)) {
593                                 revs->max_age = atoi(arg + 10);
594                                 continue;
595                         }
596                         if (!strncmp(arg, "--since=", 8)) {
597                                 revs->max_age = approxidate(arg + 8);
598                                 continue;
599                         }
600                         if (!strncmp(arg, "--after=", 8)) {
601                                 revs->max_age = approxidate(arg + 8);
602                                 continue;
603                         }
604                         if (!strncmp(arg, "--min-age=", 10)) {
605                                 revs->min_age = atoi(arg + 10);
606                                 continue;
607                         }
608                         if (!strncmp(arg, "--before=", 9)) {
609                                 revs->min_age = approxidate(arg + 9);
610                                 continue;
611                         }
612                         if (!strncmp(arg, "--until=", 8)) {
613                                 revs->min_age = approxidate(arg + 8);
614                                 continue;
615                         }
616                         if (!strcmp(arg, "--all")) {
617                                 handle_all(revs, flags);
618                                 continue;
619                         }
620                         if (!strcmp(arg, "--not")) {
621                                 flags ^= UNINTERESTING;
622                                 continue;
623                         }
624                         if (!strcmp(arg, "--default")) {
625                                 if (++i >= argc)
626                                         die("bad --default argument");
627                                 def = argv[i];
628                                 continue;
629                         }
630                         if (!strcmp(arg, "--topo-order")) {
631                                 revs->topo_order = 1;
632                                 continue;
633                         }
634                         if (!strcmp(arg, "--date-order")) {
635                                 revs->lifo = 0;
636                                 revs->topo_order = 1;
637                                 continue;
638                         }
639                         if (!strcmp(arg, "--parents")) {
640                                 revs->parents = 1;
641                                 continue;
642                         }
643                         if (!strcmp(arg, "--dense")) {
644                                 revs->dense = 1;
645                                 continue;
646                         }
647                         if (!strcmp(arg, "--sparse")) {
648                                 revs->dense = 0;
649                                 continue;
650                         }
651                         if (!strcmp(arg, "--remove-empty")) {
652                                 revs->remove_empty_trees = 1;
653                                 continue;
654                         }
655                         if (!strcmp(arg, "--no-merges")) {
656                                 revs->no_merges = 1;
657                                 continue;
658                         }
659                         if (!strcmp(arg, "--boundary")) {
660                                 revs->boundary = 1;
661                                 continue;
662                         }
663                         if (!strcmp(arg, "--objects")) {
664                                 revs->tag_objects = 1;
665                                 revs->tree_objects = 1;
666                                 revs->blob_objects = 1;
667                                 continue;
668                         }
669                         if (!strcmp(arg, "--objects-edge")) {
670                                 revs->tag_objects = 1;
671                                 revs->tree_objects = 1;
672                                 revs->blob_objects = 1;
673                                 revs->edge_hint = 1;
674                                 continue;
675                         }
676                         if (!strcmp(arg, "--unpacked")) {
677                                 revs->unpacked = 1;
678                                 continue;
679                         }
680                         if (!strcmp(arg, "-r")) {
681                                 revs->diff = 1;
682                                 revs->diffopt.recursive = 1;
683                                 continue;
684                         }
685                         if (!strcmp(arg, "-t")) {
686                                 revs->diff = 1;
687                                 revs->diffopt.recursive = 1;
688                                 revs->diffopt.tree_in_recursive = 1;
689                                 continue;
690                         }
691                         if (!strcmp(arg, "-m")) {
692                                 revs->ignore_merges = 0;
693                                 continue;
694                         }
695                         if (!strcmp(arg, "-c")) {
696                                 revs->diff = 1;
697                                 revs->dense_combined_merges = 0;
698                                 revs->combine_merges = 1;
699                                 continue;
700                         }
701                         if (!strcmp(arg, "--cc")) {
702                                 revs->diff = 1;
703                                 revs->dense_combined_merges = 1;
704                                 revs->combine_merges = 1;
705                                 continue;
706                         }
707                         if (!strcmp(arg, "-v")) {
708                                 revs->verbose_header = 1;
709                                 continue;
710                         }
711                         if (!strncmp(arg, "--pretty", 8)) {
712                                 revs->verbose_header = 1;
713                                 revs->commit_format = get_commit_format(arg+8);
714                                 continue;
715                         }
716                         if (!strcmp(arg, "--root")) {
717                                 revs->show_root_diff = 1;
718                                 continue;
719                         }
720                         if (!strcmp(arg, "--no-commit-id")) {
721                                 revs->no_commit_id = 1;
722                                 continue;
723                         }
724                         if (!strcmp(arg, "--always")) {
725                                 revs->always_show_header = 1;
726                                 continue;
727                         }
728                         if (!strcmp(arg, "--no-abbrev")) {
729                                 revs->abbrev = 0;
730                                 continue;
731                         }
732                         if (!strcmp(arg, "--abbrev")) {
733                                 revs->abbrev = DEFAULT_ABBREV;
734                                 continue;
735                         }
736                         if (!strcmp(arg, "--abbrev-commit")) {
737                                 revs->abbrev_commit = 1;
738                                 continue;
739                         }
740                         if (!strcmp(arg, "--full-diff")) {
741                                 revs->diff = 1;
742                                 revs->full_diff = 1;
743                                 continue;
744                         }
745                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
746                         if (opts > 0) {
747                                 revs->diff = 1;
748                                 i += opts - 1;
749                                 continue;
750                         }
751                         *unrecognized++ = arg;
752                         left++;
753                         continue;
754                 }
755                 dotdot = strstr(arg, "..");
756                 if (dotdot) {
757                         unsigned char from_sha1[20];
758                         const char *next = dotdot + 2;
759                         const char *this = arg;
760                         *dotdot = 0;
761                         if (!*next)
762                                 next = "HEAD";
763                         if (dotdot == arg)
764                                 this = "HEAD";
765                         if (!get_sha1(this, from_sha1) &&
766                             !get_sha1(next, sha1)) {
767                                 struct object *exclude;
768                                 struct object *include;
769
770                                 exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
771                                 include = get_reference(revs, next, sha1, flags);
772                                 if (!exclude || !include)
773                                         die("Invalid revision range %s..%s", arg, next);
774
775                                 if (!seen_dashdash) {
776                                         *dotdot = '.';
777                                         verify_non_filename(revs->prefix, arg);
778                                 }
779                                 add_pending_object(revs, exclude, this);
780                                 add_pending_object(revs, include, next);
781                                 continue;
782                         }
783                         *dotdot = '.';
784                 }
785                 dotdot = strstr(arg, "^@");
786                 if (dotdot && !dotdot[2]) {
787                         *dotdot = 0;
788                         if (add_parents_only(revs, arg, flags))
789                                 continue;
790                         *dotdot = '^';
791                 }
792                 local_flags = 0;
793                 if (*arg == '^') {
794                         local_flags = UNINTERESTING;
795                         arg++;
796                 }
797                 if (get_sha1(arg, sha1) < 0) {
798                         int j;
799
800                         if (seen_dashdash || local_flags)
801                                 die("bad revision '%s'", arg);
802
803                         /* If we didn't have a "--":
804                          * (1) all filenames must exist;
805                          * (2) all rev-args must not be interpretable
806                          *     as a valid filename.
807                          * but the latter we have checked in the main loop.
808                          */
809                         for (j = i; j < argc; j++)
810                                 verify_filename(revs->prefix, argv[j]);
811
812                         revs->prune_data = get_pathspec(revs->prefix, argv + i);
813                         break;
814                 }
815                 if (!seen_dashdash)
816                         verify_non_filename(revs->prefix, arg);
817                 object = get_reference(revs, arg, sha1, flags ^ local_flags);
818                 add_pending_object(revs, object, arg);
819         }
820         if (def && !revs->pending_objects) {
821                 unsigned char sha1[20];
822                 struct object *object;
823                 if (get_sha1(def, sha1) < 0)
824                         die("bad default revision '%s'", def);
825                 object = get_reference(revs, def, sha1, 0);
826                 add_pending_object(revs, object, def);
827         }
828
829         if (revs->topo_order || revs->unpacked)
830                 revs->limited = 1;
831
832         if (revs->prune_data) {
833                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
834                 revs->prune_fn = try_to_simplify_commit;
835                 if (!revs->full_diff)
836                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
837         }
838         if (revs->combine_merges) {
839                 revs->ignore_merges = 0;
840                 if (revs->dense_combined_merges &&
841                     (revs->diffopt.output_format != DIFF_FORMAT_DIFFSTAT))
842                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
843         }
844         revs->diffopt.abbrev = revs->abbrev;
845         diff_setup_done(&revs->diffopt);
846
847         return left;
848 }
849
850 void prepare_revision_walk(struct rev_info *revs)
851 {
852         struct object_list *list;
853
854         list = revs->pending_objects;
855         revs->pending_objects = NULL;
856         while (list) {
857                 struct commit *commit = handle_commit(revs, list->item, list->name);
858                 if (commit) {
859                         if (!(commit->object.flags & SEEN)) {
860                                 commit->object.flags |= SEEN;
861                                 insert_by_date(commit, &revs->commits);
862                         }
863                 }
864                 list = list->next;
865         }
866
867         if (revs->no_walk)
868                 return;
869         if (revs->limited)
870                 limit_list(revs);
871         if (revs->topo_order)
872                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
873                                              revs->topo_setter,
874                                              revs->topo_getter);
875 }
876
877 static int rewrite_one(struct rev_info *revs, struct commit **pp)
878 {
879         for (;;) {
880                 struct commit *p = *pp;
881                 if (!revs->limited)
882                         add_parents_to_list(revs, p, &revs->commits);
883                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
884                         return 0;
885                 if (!p->parents)
886                         return -1;
887                 *pp = p->parents->item;
888         }
889 }
890
891 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
892 {
893         struct commit_list **pp = &commit->parents;
894         while (*pp) {
895                 struct commit_list *parent = *pp;
896                 if (rewrite_one(revs, &parent->item) < 0) {
897                         *pp = parent->next;
898                         continue;
899                 }
900                 pp = &parent->next;
901         }
902 }
903
904 static void mark_boundary_to_show(struct commit *commit)
905 {
906         struct commit_list *p = commit->parents;
907         while (p) {
908                 commit = p->item;
909                 p = p->next;
910                 if (commit->object.flags & BOUNDARY)
911                         commit->object.flags |= BOUNDARY_SHOW;
912         }
913 }
914
915 struct commit *get_revision(struct rev_info *revs)
916 {
917         struct commit_list *list = revs->commits;
918
919         if (!list)
920                 return NULL;
921
922         /* Check the max_count ... */
923         switch (revs->max_count) {
924         case -1:
925                 break;
926         case 0:
927                 return NULL;
928         default:
929                 revs->max_count--;
930         }
931
932         do {
933                 struct commit *commit = revs->commits->item;
934
935                 revs->commits = revs->commits->next;
936
937                 /*
938                  * If we haven't done the list limiting, we need to look at
939                  * the parents here. We also need to do the date-based limiting
940                  * that we'd otherwise have done in limit_list().
941                  */
942                 if (!revs->limited) {
943                         if ((revs->unpacked &&
944                              has_sha1_pack(commit->object.sha1)) ||
945                             (revs->max_age != -1 &&
946                              (commit->date < revs->max_age)))
947                                 continue;
948                         add_parents_to_list(revs, commit, &revs->commits);
949                 }
950                 if (commit->object.flags & SHOWN)
951                         continue;
952
953                 /* We want to show boundary commits only when their
954                  * children are shown.  When path-limiter is in effect,
955                  * rewrite_parents() drops some commits from getting shown,
956                  * and there is no point showing boundary parents that
957                  * are not shown.  After rewrite_parents() rewrites the
958                  * parents of a commit that is shown, we mark the boundary
959                  * parents with BOUNDARY_SHOW.
960                  */
961                 if (commit->object.flags & BOUNDARY_SHOW) {
962                         commit->object.flags |= SHOWN;
963                         return commit;
964                 }
965                 if (commit->object.flags & UNINTERESTING)
966                         continue;
967                 if (revs->min_age != -1 && (commit->date > revs->min_age))
968                         continue;
969                 if (revs->no_merges &&
970                     commit->parents && commit->parents->next)
971                         continue;
972                 if (revs->prune_fn && revs->dense) {
973                         if (!(commit->object.flags & TREECHANGE))
974                                 continue;
975                         if (revs->parents)
976                                 rewrite_parents(revs, commit);
977                 }
978                 if (revs->boundary)
979                         mark_boundary_to_show(commit);
980                 commit->object.flags |= SHOWN;
981                 return commit;
982         } while (revs->commits);
983         return NULL;
984 }