Make left-right automatic.
[git] / revision.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "refs.h"
8 #include "revision.h"
9 #include <regex.h>
10 #include "grep.h"
11
12 static char *path_name(struct name_path *path, const char *name)
13 {
14         struct name_path *p;
15         char *n, *m;
16         int nlen = strlen(name);
17         int len = nlen + 1;
18
19         for (p = path; p; p = p->up) {
20                 if (p->elem_len)
21                         len += p->elem_len + 1;
22         }
23         n = xmalloc(len);
24         m = n + len - (nlen + 1);
25         strcpy(m, name);
26         for (p = path; p; p = p->up) {
27                 if (p->elem_len) {
28                         m -= p->elem_len + 1;
29                         memcpy(m, p->elem, p->elem_len);
30                         m[p->elem_len] = '/';
31                 }
32         }
33         return n;
34 }
35
36 void add_object(struct object *obj,
37                 struct object_array *p,
38                 struct name_path *path,
39                 const char *name)
40 {
41         add_object_array(obj, path_name(path, name), p);
42 }
43
44 static void mark_blob_uninteresting(struct blob *blob)
45 {
46         if (blob->object.flags & UNINTERESTING)
47                 return;
48         blob->object.flags |= UNINTERESTING;
49 }
50
51 void mark_tree_uninteresting(struct tree *tree)
52 {
53         struct tree_desc desc;
54         struct name_entry entry;
55         struct object *obj = &tree->object;
56
57         if (obj->flags & UNINTERESTING)
58                 return;
59         obj->flags |= UNINTERESTING;
60         if (!has_sha1_file(obj->sha1))
61                 return;
62         if (parse_tree(tree) < 0)
63                 die("bad tree %s", sha1_to_hex(obj->sha1));
64
65         desc.buf = tree->buffer;
66         desc.size = tree->size;
67         while (tree_entry(&desc, &entry)) {
68                 if (S_ISDIR(entry.mode))
69                         mark_tree_uninteresting(lookup_tree(entry.sha1));
70                 else
71                         mark_blob_uninteresting(lookup_blob(entry.sha1));
72         }
73
74         /*
75          * We don't care about the tree any more
76          * after it has been marked uninteresting.
77          */
78         free(tree->buffer);
79         tree->buffer = NULL;
80 }
81
82 void mark_parents_uninteresting(struct commit *commit)
83 {
84         struct commit_list *parents = commit->parents;
85
86         while (parents) {
87                 struct commit *commit = parents->item;
88                 if (!(commit->object.flags & UNINTERESTING)) {
89                         commit->object.flags |= UNINTERESTING;
90
91                         /*
92                          * Normally we haven't parsed the parent
93                          * yet, so we won't have a parent of a parent
94                          * here. However, it may turn out that we've
95                          * reached this commit some other way (where it
96                          * wasn't uninteresting), in which case we need
97                          * to mark its parents recursively too..
98                          */
99                         if (commit->parents)
100                                 mark_parents_uninteresting(commit);
101                 }
102
103                 /*
104                  * A missing commit is ok iff its parent is marked
105                  * uninteresting.
106                  *
107                  * We just mark such a thing parsed, so that when
108                  * it is popped next time around, we won't be trying
109                  * to parse it and get an error.
110                  */
111                 if (!has_sha1_file(commit->object.sha1))
112                         commit->object.parsed = 1;
113                 parents = parents->next;
114         }
115 }
116
117 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
118 {
119         add_object_array(obj, name, &revs->pending);
120 }
121
122 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
123 {
124         struct object *object;
125
126         object = parse_object(sha1);
127         if (!object)
128                 die("bad object %s", name);
129         object->flags |= flags;
130         return object;
131 }
132
133 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
134 {
135         unsigned long flags = object->flags;
136
137         /*
138          * Tag object? Look what it points to..
139          */
140         while (object->type == OBJ_TAG) {
141                 struct tag *tag = (struct tag *) object;
142                 if (revs->tag_objects && !(flags & UNINTERESTING))
143                         add_pending_object(revs, object, tag->tag);
144                 object = parse_object(tag->tagged->sha1);
145                 if (!object)
146                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
147         }
148
149         /*
150          * Commit object? Just return it, we'll do all the complex
151          * reachability crud.
152          */
153         if (object->type == OBJ_COMMIT) {
154                 struct commit *commit = (struct commit *)object;
155                 if (parse_commit(commit) < 0)
156                         die("unable to parse commit %s", name);
157                 if (flags & UNINTERESTING) {
158                         commit->object.flags |= UNINTERESTING;
159                         mark_parents_uninteresting(commit);
160                         revs->limited = 1;
161                 }
162                 return commit;
163         }
164
165         /*
166          * Tree object? Either mark it uniniteresting, or add it
167          * to the list of objects to look at later..
168          */
169         if (object->type == OBJ_TREE) {
170                 struct tree *tree = (struct tree *)object;
171                 if (!revs->tree_objects)
172                         return NULL;
173                 if (flags & UNINTERESTING) {
174                         mark_tree_uninteresting(tree);
175                         return NULL;
176                 }
177                 add_pending_object(revs, object, "");
178                 return NULL;
179         }
180
181         /*
182          * Blob object? You know the drill by now..
183          */
184         if (object->type == OBJ_BLOB) {
185                 struct blob *blob = (struct blob *)object;
186                 if (!revs->blob_objects)
187                         return NULL;
188                 if (flags & UNINTERESTING) {
189                         mark_blob_uninteresting(blob);
190                         return NULL;
191                 }
192                 add_pending_object(revs, object, "");
193                 return NULL;
194         }
195         die("%s is unknown object", name);
196 }
197
198 static int everybody_uninteresting(struct commit_list *orig)
199 {
200         struct commit_list *list = orig;
201         while (list) {
202                 struct commit *commit = list->item;
203                 list = list->next;
204                 if (commit->object.flags & UNINTERESTING)
205                         continue;
206                 return 0;
207         }
208         return 1;
209 }
210
211 static int tree_difference = REV_TREE_SAME;
212
213 static void file_add_remove(struct diff_options *options,
214                     int addremove, unsigned mode,
215                     const unsigned char *sha1,
216                     const char *base, const char *path)
217 {
218         int diff = REV_TREE_DIFFERENT;
219
220         /*
221          * Is it an add of a new file? It means that the old tree
222          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
223          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
224          * (and if it already was "REV_TREE_NEW", we'll keep it
225          * "REV_TREE_NEW" of course).
226          */
227         if (addremove == '+') {
228                 diff = tree_difference;
229                 if (diff != REV_TREE_SAME)
230                         return;
231                 diff = REV_TREE_NEW;
232         }
233         tree_difference = diff;
234 }
235
236 static void file_change(struct diff_options *options,
237                  unsigned old_mode, unsigned new_mode,
238                  const unsigned char *old_sha1,
239                  const unsigned char *new_sha1,
240                  const char *base, const char *path)
241 {
242         tree_difference = REV_TREE_DIFFERENT;
243 }
244
245 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
246 {
247         if (!t1)
248                 return REV_TREE_NEW;
249         if (!t2)
250                 return REV_TREE_DIFFERENT;
251         tree_difference = REV_TREE_SAME;
252         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
253                            &revs->pruning) < 0)
254                 return REV_TREE_DIFFERENT;
255         return tree_difference;
256 }
257
258 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
259 {
260         int retval;
261         void *tree;
262         struct tree_desc empty, real;
263
264         if (!t1)
265                 return 0;
266
267         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
268         if (!tree)
269                 return 0;
270         real.buf = tree;
271
272         empty.buf = "";
273         empty.size = 0;
274
275         tree_difference = 0;
276         retval = diff_tree(&empty, &real, "", &revs->pruning);
277         free(tree);
278
279         return retval >= 0 && !tree_difference;
280 }
281
282 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
283 {
284         struct commit_list **pp, *parent;
285         int tree_changed = 0, tree_same = 0;
286
287         if (!commit->tree)
288                 return;
289
290         if (!commit->parents) {
291                 if (!rev_same_tree_as_empty(revs, commit->tree))
292                         commit->object.flags |= TREECHANGE;
293                 return;
294         }
295
296         pp = &commit->parents;
297         while ((parent = *pp) != NULL) {
298                 struct commit *p = parent->item;
299
300                 parse_commit(p);
301                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
302                 case REV_TREE_SAME:
303                         tree_same = 1;
304                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
305                                 /* Even if a merge with an uninteresting
306                                  * side branch brought the entire change
307                                  * we are interested in, we do not want
308                                  * to lose the other branches of this
309                                  * merge, so we just keep going.
310                                  */
311                                 pp = &parent->next;
312                                 continue;
313                         }
314                         parent->next = NULL;
315                         commit->parents = parent;
316                         return;
317
318                 case REV_TREE_NEW:
319                         if (revs->remove_empty_trees &&
320                             rev_same_tree_as_empty(revs, p->tree)) {
321                                 /* We are adding all the specified
322                                  * paths from this parent, so the
323                                  * history beyond this parent is not
324                                  * interesting.  Remove its parents
325                                  * (they are grandparents for us).
326                                  * IOW, we pretend this parent is a
327                                  * "root" commit.
328                                  */
329                                 parse_commit(p);
330                                 p->parents = NULL;
331                         }
332                 /* fallthrough */
333                 case REV_TREE_DIFFERENT:
334                         tree_changed = 1;
335                         pp = &parent->next;
336                         continue;
337                 }
338                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
339         }
340         if (tree_changed && !tree_same)
341                 commit->object.flags |= TREECHANGE;
342 }
343
344 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
345 {
346         struct commit_list *parent = commit->parents;
347         unsigned left_flag;
348
349         if (commit->object.flags & ADDED)
350                 return;
351         commit->object.flags |= ADDED;
352
353         /*
354          * If the commit is uninteresting, don't try to
355          * prune parents - we want the maximal uninteresting
356          * set.
357          *
358          * Normally we haven't parsed the parent
359          * yet, so we won't have a parent of a parent
360          * here. However, it may turn out that we've
361          * reached this commit some other way (where it
362          * wasn't uninteresting), in which case we need
363          * to mark its parents recursively too..
364          */
365         if (commit->object.flags & UNINTERESTING) {
366                 while (parent) {
367                         struct commit *p = parent->item;
368                         parent = parent->next;
369                         parse_commit(p);
370                         p->object.flags |= UNINTERESTING;
371                         if (p->parents)
372                                 mark_parents_uninteresting(p);
373                         if (p->object.flags & SEEN)
374                                 continue;
375                         p->object.flags |= SEEN;
376                         insert_by_date(p, list);
377                 }
378                 return;
379         }
380
381         /*
382          * Ok, the commit wasn't uninteresting. Try to
383          * simplify the commit history and find the parent
384          * that has no differences in the path set if one exists.
385          */
386         if (revs->prune_fn)
387                 revs->prune_fn(revs, commit);
388
389         if (revs->no_walk)
390                 return;
391
392         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
393         parent = commit->parents;
394         while (parent) {
395                 struct commit *p = parent->item;
396
397                 parent = parent->next;
398
399                 parse_commit(p);
400                 p->object.flags |= left_flag;
401                 if (p->object.flags & SEEN)
402                         continue;
403                 p->object.flags |= SEEN;
404                 insert_by_date(p, list);
405         }
406 }
407
408 static void limit_list(struct rev_info *revs)
409 {
410         struct commit_list *list = revs->commits;
411         struct commit_list *newlist = NULL;
412         struct commit_list **p = &newlist;
413
414         while (list) {
415                 struct commit_list *entry = list;
416                 struct commit *commit = list->item;
417                 struct object *obj = &commit->object;
418
419                 list = list->next;
420                 free(entry);
421
422                 if (revs->max_age != -1 && (commit->date < revs->max_age))
423                         obj->flags |= UNINTERESTING;
424                 add_parents_to_list(revs, commit, &list);
425                 if (obj->flags & UNINTERESTING) {
426                         mark_parents_uninteresting(commit);
427                         if (everybody_uninteresting(list))
428                                 break;
429                         continue;
430                 }
431                 if (revs->min_age != -1 && (commit->date > revs->min_age))
432                         continue;
433                 p = &commit_list_insert(commit, p)->next;
434         }
435         if (revs->boundary) {
436                 /* mark the ones that are on the result list first */
437                 for (list = newlist; list; list = list->next) {
438                         struct commit *commit = list->item;
439                         commit->object.flags |= TMP_MARK;
440                 }
441                 for (list = newlist; list; list = list->next) {
442                         struct commit *commit = list->item;
443                         struct object *obj = &commit->object;
444                         struct commit_list *parent;
445                         if (obj->flags & UNINTERESTING)
446                                 continue;
447                         for (parent = commit->parents;
448                              parent;
449                              parent = parent->next) {
450                                 struct commit *pcommit = parent->item;
451                                 if (!(pcommit->object.flags & UNINTERESTING))
452                                         continue;
453                                 pcommit->object.flags |= BOUNDARY;
454                                 if (pcommit->object.flags & TMP_MARK)
455                                         continue;
456                                 pcommit->object.flags |= TMP_MARK;
457                                 p = &commit_list_insert(pcommit, p)->next;
458                         }
459                 }
460                 for (list = newlist; list; list = list->next) {
461                         struct commit *commit = list->item;
462                         commit->object.flags &= ~TMP_MARK;
463                 }
464         }
465         revs->commits = newlist;
466 }
467
468 static int all_flags;
469 static struct rev_info *all_revs;
470
471 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
472 {
473         struct object *object = get_reference(all_revs, path, sha1, all_flags);
474         add_pending_object(all_revs, object, "");
475         return 0;
476 }
477
478 static void handle_all(struct rev_info *revs, unsigned flags)
479 {
480         all_revs = revs;
481         all_flags = flags;
482         for_each_ref(handle_one_ref, NULL);
483 }
484
485 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
486 {
487         unsigned char sha1[20];
488         struct object *it;
489         struct commit *commit;
490         struct commit_list *parents;
491
492         if (*arg == '^') {
493                 flags ^= UNINTERESTING;
494                 arg++;
495         }
496         if (get_sha1(arg, sha1))
497                 return 0;
498         while (1) {
499                 it = get_reference(revs, arg, sha1, 0);
500                 if (it->type != OBJ_TAG)
501                         break;
502                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
503         }
504         if (it->type != OBJ_COMMIT)
505                 return 0;
506         commit = (struct commit *)it;
507         for (parents = commit->parents; parents; parents = parents->next) {
508                 it = &parents->item->object;
509                 it->flags |= flags;
510                 add_pending_object(revs, it, arg);
511         }
512         return 1;
513 }
514
515 void init_revisions(struct rev_info *revs, const char *prefix)
516 {
517         memset(revs, 0, sizeof(*revs));
518
519         revs->abbrev = DEFAULT_ABBREV;
520         revs->ignore_merges = 1;
521         revs->simplify_history = 1;
522         revs->pruning.recursive = 1;
523         revs->pruning.add_remove = file_add_remove;
524         revs->pruning.change = file_change;
525         revs->lifo = 1;
526         revs->dense = 1;
527         revs->prefix = prefix;
528         revs->max_age = -1;
529         revs->min_age = -1;
530         revs->max_count = -1;
531
532         revs->prune_fn = NULL;
533         revs->prune_data = NULL;
534
535         revs->topo_setter = topo_sort_default_setter;
536         revs->topo_getter = topo_sort_default_getter;
537
538         revs->commit_format = CMIT_FMT_DEFAULT;
539
540         diff_setup(&revs->diffopt);
541 }
542
543 static void add_pending_commit_list(struct rev_info *revs,
544                                     struct commit_list *commit_list,
545                                     unsigned int flags)
546 {
547         while (commit_list) {
548                 struct object *object = &commit_list->item->object;
549                 object->flags |= flags;
550                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
551                 commit_list = commit_list->next;
552         }
553 }
554
555 static void prepare_show_merge(struct rev_info *revs)
556 {
557         struct commit_list *bases;
558         struct commit *head, *other;
559         unsigned char sha1[20];
560         const char **prune = NULL;
561         int i, prune_num = 1; /* counting terminating NULL */
562
563         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
564                 die("--merge without HEAD?");
565         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
566                 die("--merge without MERGE_HEAD?");
567         add_pending_object(revs, &head->object, "HEAD");
568         add_pending_object(revs, &other->object, "MERGE_HEAD");
569         bases = get_merge_bases(head, other, 1);
570         while (bases) {
571                 struct commit *it = bases->item;
572                 struct commit_list *n = bases->next;
573                 free(bases);
574                 bases = n;
575                 it->object.flags |= UNINTERESTING;
576                 add_pending_object(revs, &it->object, "(merge-base)");
577         }
578
579         if (!active_nr)
580                 read_cache();
581         for (i = 0; i < active_nr; i++) {
582                 struct cache_entry *ce = active_cache[i];
583                 if (!ce_stage(ce))
584                         continue;
585                 if (ce_path_match(ce, revs->prune_data)) {
586                         prune_num++;
587                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
588                         prune[prune_num-2] = ce->name;
589                         prune[prune_num-1] = NULL;
590                 }
591                 while ((i+1 < active_nr) &&
592                        ce_same_name(ce, active_cache[i+1]))
593                         i++;
594         }
595         revs->prune_data = prune;
596 }
597
598 int handle_revision_arg(const char *arg, struct rev_info *revs,
599                         int flags,
600                         int cant_be_filename)
601 {
602         char *dotdot;
603         struct object *object;
604         unsigned char sha1[20];
605         int local_flags;
606
607         dotdot = strstr(arg, "..");
608         if (dotdot) {
609                 unsigned char from_sha1[20];
610                 const char *next = dotdot + 2;
611                 const char *this = arg;
612                 int symmetric = *next == '.';
613                 unsigned int flags_exclude = flags ^ UNINTERESTING;
614
615                 *dotdot = 0;
616                 next += symmetric;
617
618                 if (!*next)
619                         next = "HEAD";
620                 if (dotdot == arg)
621                         this = "HEAD";
622                 if (!get_sha1(this, from_sha1) &&
623                     !get_sha1(next, sha1)) {
624                         struct commit *a, *b;
625                         struct commit_list *exclude;
626
627                         a = lookup_commit_reference(from_sha1);
628                         b = lookup_commit_reference(sha1);
629                         if (!a || !b) {
630                                 die(symmetric ?
631                                     "Invalid symmetric difference expression %s...%s" :
632                                     "Invalid revision range %s..%s",
633                                     arg, next);
634                         }
635
636                         if (!cant_be_filename) {
637                                 *dotdot = '.';
638                                 verify_non_filename(revs->prefix, arg);
639                         }
640
641                         if (symmetric) {
642                                 exclude = get_merge_bases(a, b, 1);
643                                 add_pending_commit_list(revs, exclude,
644                                                         flags_exclude);
645                                 free_commit_list(exclude);
646                                 a->object.flags |= flags | SYMMETRIC_LEFT;
647                         } else
648                                 a->object.flags |= flags_exclude;
649                         b->object.flags |= flags;
650                         add_pending_object(revs, &a->object, this);
651                         add_pending_object(revs, &b->object, next);
652                         return 0;
653                 }
654                 *dotdot = '.';
655         }
656         dotdot = strstr(arg, "^@");
657         if (dotdot && !dotdot[2]) {
658                 *dotdot = 0;
659                 if (add_parents_only(revs, arg, flags))
660                         return 0;
661                 *dotdot = '^';
662         }
663         dotdot = strstr(arg, "^!");
664         if (dotdot && !dotdot[2]) {
665                 *dotdot = 0;
666                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
667                         *dotdot = '^';
668         }
669
670         local_flags = 0;
671         if (*arg == '^') {
672                 local_flags = UNINTERESTING;
673                 arg++;
674         }
675         if (get_sha1(arg, sha1))
676                 return -1;
677         if (!cant_be_filename)
678                 verify_non_filename(revs->prefix, arg);
679         object = get_reference(revs, arg, sha1, flags ^ local_flags);
680         add_pending_object(revs, object, arg);
681         return 0;
682 }
683
684 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
685 {
686         if (!revs->grep_filter) {
687                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
688                 opt->status_only = 1;
689                 opt->pattern_tail = &(opt->pattern_list);
690                 opt->regflags = REG_NEWLINE;
691                 revs->grep_filter = opt;
692         }
693         append_grep_pattern(revs->grep_filter, ptn,
694                             "command line", 0, what);
695 }
696
697 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
698 {
699         char *pat;
700         const char *prefix;
701         int patlen, fldlen;
702
703         fldlen = strlen(field);
704         patlen = strlen(pattern);
705         pat = xmalloc(patlen + fldlen + 10);
706         prefix = ".*";
707         if (*pattern == '^') {
708                 prefix = "";
709                 pattern++;
710         }
711         sprintf(pat, "^%s %s%s", field, prefix, pattern);
712         add_grep(revs, pat, GREP_PATTERN_HEAD);
713 }
714
715 static void add_message_grep(struct rev_info *revs, const char *pattern)
716 {
717         add_grep(revs, pattern, GREP_PATTERN_BODY);
718 }
719
720 static void add_ignore_packed(struct rev_info *revs, const char *name)
721 {
722         int num = ++revs->num_ignore_packed;
723
724         revs->ignore_packed = xrealloc(revs->ignore_packed,
725                                        sizeof(const char **) * (num + 1));
726         revs->ignore_packed[num-1] = name;
727         revs->ignore_packed[num] = NULL;
728 }
729
730 /*
731  * Parse revision information, filling in the "rev_info" structure,
732  * and removing the used arguments from the argument list.
733  *
734  * Returns the number of arguments left that weren't recognized
735  * (which are also moved to the head of the argument list)
736  */
737 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
738 {
739         int i, flags, seen_dashdash, show_merge;
740         const char **unrecognized = argv + 1;
741         int left = 1;
742         int all_match = 0;
743
744         /* First, search for "--" */
745         seen_dashdash = 0;
746         for (i = 1; i < argc; i++) {
747                 const char *arg = argv[i];
748                 if (strcmp(arg, "--"))
749                         continue;
750                 argv[i] = NULL;
751                 argc = i;
752                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
753                 seen_dashdash = 1;
754                 break;
755         }
756
757         flags = show_merge = 0;
758         for (i = 1; i < argc; i++) {
759                 const char *arg = argv[i];
760                 if (*arg == '-') {
761                         int opts;
762                         if (!strncmp(arg, "--max-count=", 12)) {
763                                 revs->max_count = atoi(arg + 12);
764                                 continue;
765                         }
766                         /* accept -<digit>, like traditional "head" */
767                         if ((*arg == '-') && isdigit(arg[1])) {
768                                 revs->max_count = atoi(arg + 1);
769                                 continue;
770                         }
771                         if (!strcmp(arg, "-n")) {
772                                 if (argc <= i + 1)
773                                         die("-n requires an argument");
774                                 revs->max_count = atoi(argv[++i]);
775                                 continue;
776                         }
777                         if (!strncmp(arg,"-n",2)) {
778                                 revs->max_count = atoi(arg + 2);
779                                 continue;
780                         }
781                         if (!strncmp(arg, "--max-age=", 10)) {
782                                 revs->max_age = atoi(arg + 10);
783                                 continue;
784                         }
785                         if (!strncmp(arg, "--since=", 8)) {
786                                 revs->max_age = approxidate(arg + 8);
787                                 continue;
788                         }
789                         if (!strncmp(arg, "--after=", 8)) {
790                                 revs->max_age = approxidate(arg + 8);
791                                 continue;
792                         }
793                         if (!strncmp(arg, "--min-age=", 10)) {
794                                 revs->min_age = atoi(arg + 10);
795                                 continue;
796                         }
797                         if (!strncmp(arg, "--before=", 9)) {
798                                 revs->min_age = approxidate(arg + 9);
799                                 continue;
800                         }
801                         if (!strncmp(arg, "--until=", 8)) {
802                                 revs->min_age = approxidate(arg + 8);
803                                 continue;
804                         }
805                         if (!strcmp(arg, "--all")) {
806                                 handle_all(revs, flags);
807                                 continue;
808                         }
809                         if (!strcmp(arg, "--not")) {
810                                 flags ^= UNINTERESTING;
811                                 continue;
812                         }
813                         if (!strcmp(arg, "--default")) {
814                                 if (++i >= argc)
815                                         die("bad --default argument");
816                                 def = argv[i];
817                                 continue;
818                         }
819                         if (!strcmp(arg, "--merge")) {
820                                 show_merge = 1;
821                                 continue;
822                         }
823                         if (!strcmp(arg, "--topo-order")) {
824                                 revs->topo_order = 1;
825                                 continue;
826                         }
827                         if (!strcmp(arg, "--date-order")) {
828                                 revs->lifo = 0;
829                                 revs->topo_order = 1;
830                                 continue;
831                         }
832                         if (!strcmp(arg, "--parents")) {
833                                 revs->parents = 1;
834                                 continue;
835                         }
836                         if (!strcmp(arg, "--dense")) {
837                                 revs->dense = 1;
838                                 continue;
839                         }
840                         if (!strcmp(arg, "--sparse")) {
841                                 revs->dense = 0;
842                                 continue;
843                         }
844                         if (!strcmp(arg, "--remove-empty")) {
845                                 revs->remove_empty_trees = 1;
846                                 continue;
847                         }
848                         if (!strcmp(arg, "--no-merges")) {
849                                 revs->no_merges = 1;
850                                 continue;
851                         }
852                         if (!strcmp(arg, "--boundary")) {
853                                 revs->boundary = 1;
854                                 continue;
855                         }
856                         if (!strcmp(arg, "--no-left-right")) {
857                                 revs->no_left_right = 1;
858                                 continue;
859                         }
860                         if (!strcmp(arg, "--objects")) {
861                                 revs->tag_objects = 1;
862                                 revs->tree_objects = 1;
863                                 revs->blob_objects = 1;
864                                 continue;
865                         }
866                         if (!strcmp(arg, "--objects-edge")) {
867                                 revs->tag_objects = 1;
868                                 revs->tree_objects = 1;
869                                 revs->blob_objects = 1;
870                                 revs->edge_hint = 1;
871                                 continue;
872                         }
873                         if (!strcmp(arg, "--unpacked")) {
874                                 revs->unpacked = 1;
875                                 free(revs->ignore_packed);
876                                 revs->ignore_packed = NULL;
877                                 revs->num_ignore_packed = 0;
878                                 continue;
879                         }
880                         if (!strncmp(arg, "--unpacked=", 11)) {
881                                 revs->unpacked = 1;
882                                 add_ignore_packed(revs, arg+11);
883                                 continue;
884                         }
885                         if (!strcmp(arg, "-r")) {
886                                 revs->diff = 1;
887                                 revs->diffopt.recursive = 1;
888                                 continue;
889                         }
890                         if (!strcmp(arg, "-t")) {
891                                 revs->diff = 1;
892                                 revs->diffopt.recursive = 1;
893                                 revs->diffopt.tree_in_recursive = 1;
894                                 continue;
895                         }
896                         if (!strcmp(arg, "-m")) {
897                                 revs->ignore_merges = 0;
898                                 continue;
899                         }
900                         if (!strcmp(arg, "-c")) {
901                                 revs->diff = 1;
902                                 revs->dense_combined_merges = 0;
903                                 revs->combine_merges = 1;
904                                 continue;
905                         }
906                         if (!strcmp(arg, "--cc")) {
907                                 revs->diff = 1;
908                                 revs->dense_combined_merges = 1;
909                                 revs->combine_merges = 1;
910                                 continue;
911                         }
912                         if (!strcmp(arg, "-v")) {
913                                 revs->verbose_header = 1;
914                                 continue;
915                         }
916                         if (!strncmp(arg, "--pretty", 8)) {
917                                 revs->verbose_header = 1;
918                                 revs->commit_format = get_commit_format(arg+8);
919                                 continue;
920                         }
921                         if (!strcmp(arg, "--root")) {
922                                 revs->show_root_diff = 1;
923                                 continue;
924                         }
925                         if (!strcmp(arg, "--no-commit-id")) {
926                                 revs->no_commit_id = 1;
927                                 continue;
928                         }
929                         if (!strcmp(arg, "--always")) {
930                                 revs->always_show_header = 1;
931                                 continue;
932                         }
933                         if (!strcmp(arg, "--no-abbrev")) {
934                                 revs->abbrev = 0;
935                                 continue;
936                         }
937                         if (!strcmp(arg, "--abbrev")) {
938                                 revs->abbrev = DEFAULT_ABBREV;
939                                 continue;
940                         }
941                         if (!strncmp(arg, "--abbrev=", 9)) {
942                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
943                                 if (revs->abbrev < MINIMUM_ABBREV)
944                                         revs->abbrev = MINIMUM_ABBREV;
945                                 else if (revs->abbrev > 40)
946                                         revs->abbrev = 40;
947                                 continue;
948                         }
949                         if (!strcmp(arg, "--abbrev-commit")) {
950                                 revs->abbrev_commit = 1;
951                                 continue;
952                         }
953                         if (!strcmp(arg, "--full-diff")) {
954                                 revs->diff = 1;
955                                 revs->full_diff = 1;
956                                 continue;
957                         }
958                         if (!strcmp(arg, "--full-history")) {
959                                 revs->simplify_history = 0;
960                                 continue;
961                         }
962                         if (!strcmp(arg, "--relative-date")) {
963                                 revs->relative_date = 1;
964                                 continue;
965                         }
966
967                         /*
968                          * Grepping the commit log
969                          */
970                         if (!strncmp(arg, "--author=", 9)) {
971                                 add_header_grep(revs, "author", arg+9);
972                                 continue;
973                         }
974                         if (!strncmp(arg, "--committer=", 12)) {
975                                 add_header_grep(revs, "committer", arg+12);
976                                 continue;
977                         }
978                         if (!strncmp(arg, "--grep=", 7)) {
979                                 add_message_grep(revs, arg+7);
980                                 continue;
981                         }
982                         if (!strcmp(arg, "--all-match")) {
983                                 all_match = 1;
984                                 continue;
985                         }
986
987                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
988                         if (opts > 0) {
989                                 revs->diff = 1;
990                                 i += opts - 1;
991                                 continue;
992                         }
993                         *unrecognized++ = arg;
994                         left++;
995                         continue;
996                 }
997
998                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
999                         int j;
1000                         if (seen_dashdash || *arg == '^')
1001                                 die("bad revision '%s'", arg);
1002
1003                         /* If we didn't have a "--":
1004                          * (1) all filenames must exist;
1005                          * (2) all rev-args must not be interpretable
1006                          *     as a valid filename.
1007                          * but the latter we have checked in the main loop.
1008                          */
1009                         for (j = i; j < argc; j++)
1010                                 verify_filename(revs->prefix, argv[j]);
1011
1012                         revs->prune_data = get_pathspec(revs->prefix,
1013                                                         argv + i);
1014                         break;
1015                 }
1016         }
1017
1018         if (show_merge)
1019                 prepare_show_merge(revs);
1020         if (def && !revs->pending.nr) {
1021                 unsigned char sha1[20];
1022                 struct object *object;
1023                 if (get_sha1(def, sha1))
1024                         die("bad default revision '%s'", def);
1025                 object = get_reference(revs, def, sha1, 0);
1026                 add_pending_object(revs, object, def);
1027         }
1028
1029         if (revs->topo_order)
1030                 revs->limited = 1;
1031
1032         if (revs->prune_data) {
1033                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1034                 revs->prune_fn = try_to_simplify_commit;
1035                 if (!revs->full_diff)
1036                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1037         }
1038         if (revs->combine_merges) {
1039                 revs->ignore_merges = 0;
1040                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1041                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1042         }
1043         revs->diffopt.abbrev = revs->abbrev;
1044         if (diff_setup_done(&revs->diffopt) < 0)
1045                 die("diff_setup_done failed");
1046
1047         if (revs->grep_filter) {
1048                 revs->grep_filter->all_match = all_match;
1049                 compile_grep_patterns(revs->grep_filter);
1050         }
1051
1052         return left;
1053 }
1054
1055 void prepare_revision_walk(struct rev_info *revs)
1056 {
1057         int nr = revs->pending.nr;
1058         int has_symmetric = 0;
1059         struct object_array_entry *list = revs->pending.objects;
1060
1061         revs->pending.nr = 0;
1062         revs->pending.alloc = 0;
1063         revs->pending.objects = NULL;
1064         while (--nr >= 0) {
1065                 struct commit *commit;
1066
1067                 if (list->item->flags & SYMMETRIC_LEFT)
1068                         has_symmetric = 1;
1069                 commit = handle_commit(revs, list->item, list->name);
1070                 if (commit) {
1071                         if (!(commit->object.flags & SEEN)) {
1072                                 commit->object.flags |= SEEN;
1073                                 insert_by_date(commit, &revs->commits);
1074                         }
1075                 }
1076                 list++;
1077         }
1078
1079         if (revs->no_walk)
1080                 return;
1081         if (!revs->no_left_right && has_symmetric)
1082                 revs->left_right = 1;
1083         if (revs->limited)
1084                 limit_list(revs);
1085         if (revs->topo_order)
1086                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1087                                              revs->topo_setter,
1088                                              revs->topo_getter);
1089 }
1090
1091 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1092 {
1093         for (;;) {
1094                 struct commit *p = *pp;
1095                 if (!revs->limited)
1096                         add_parents_to_list(revs, p, &revs->commits);
1097                 if (p->parents && p->parents->next)
1098                         return 0;
1099                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1100                         return 0;
1101                 if (!p->parents)
1102                         return -1;
1103                 *pp = p->parents->item;
1104         }
1105 }
1106
1107 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1108 {
1109         struct commit_list **pp = &commit->parents;
1110         while (*pp) {
1111                 struct commit_list *parent = *pp;
1112                 if (rewrite_one(revs, &parent->item) < 0) {
1113                         *pp = parent->next;
1114                         continue;
1115                 }
1116                 pp = &parent->next;
1117         }
1118 }
1119
1120 static void mark_boundary_to_show(struct commit *commit)
1121 {
1122         struct commit_list *p = commit->parents;
1123         while (p) {
1124                 commit = p->item;
1125                 p = p->next;
1126                 if (commit->object.flags & BOUNDARY)
1127                         commit->object.flags |= BOUNDARY_SHOW;
1128         }
1129 }
1130
1131 static int commit_match(struct commit *commit, struct rev_info *opt)
1132 {
1133         if (!opt->grep_filter)
1134                 return 1;
1135         return grep_buffer(opt->grep_filter,
1136                            NULL, /* we say nothing, not even filename */
1137                            commit->buffer, strlen(commit->buffer));
1138 }
1139
1140 struct commit *get_revision(struct rev_info *revs)
1141 {
1142         struct commit_list *list = revs->commits;
1143
1144         if (!list)
1145                 return NULL;
1146
1147         /* Check the max_count ... */
1148         switch (revs->max_count) {
1149         case -1:
1150                 break;
1151         case 0:
1152                 return NULL;
1153         default:
1154                 revs->max_count--;
1155         }
1156
1157         do {
1158                 struct commit_list *entry = revs->commits;
1159                 struct commit *commit = entry->item;
1160
1161                 revs->commits = entry->next;
1162                 free(entry);
1163
1164                 /*
1165                  * If we haven't done the list limiting, we need to look at
1166                  * the parents here. We also need to do the date-based limiting
1167                  * that we'd otherwise have done in limit_list().
1168                  */
1169                 if (!revs->limited) {
1170                         if (revs->max_age != -1 &&
1171                             (commit->date < revs->max_age))
1172                                 continue;
1173                         add_parents_to_list(revs, commit, &revs->commits);
1174                 }
1175                 if (commit->object.flags & SHOWN)
1176                         continue;
1177
1178                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1179                                                     revs->ignore_packed))
1180                     continue;
1181
1182                 /* We want to show boundary commits only when their
1183                  * children are shown.  When path-limiter is in effect,
1184                  * rewrite_parents() drops some commits from getting shown,
1185                  * and there is no point showing boundary parents that
1186                  * are not shown.  After rewrite_parents() rewrites the
1187                  * parents of a commit that is shown, we mark the boundary
1188                  * parents with BOUNDARY_SHOW.
1189                  */
1190                 if (commit->object.flags & BOUNDARY_SHOW) {
1191                         commit->object.flags |= SHOWN;
1192                         return commit;
1193                 }
1194                 if (commit->object.flags & UNINTERESTING)
1195                         continue;
1196                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1197                         continue;
1198                 if (revs->no_merges &&
1199                     commit->parents && commit->parents->next)
1200                         continue;
1201                 if (!commit_match(commit, revs))
1202                         continue;
1203                 if (revs->prune_fn && revs->dense) {
1204                         /* Commit without changes? */
1205                         if (!(commit->object.flags & TREECHANGE)) {
1206                                 /* drop merges unless we want parenthood */
1207                                 if (!revs->parents)
1208                                         continue;
1209                                 /* non-merge - always ignore it */
1210                                 if (!commit->parents || !commit->parents->next)
1211                                         continue;
1212                         }
1213                         if (revs->parents)
1214                                 rewrite_parents(revs, commit);
1215                 }
1216                 if (revs->boundary)
1217                         mark_boundary_to_show(commit);
1218                 commit->object.flags |= SHOWN;
1219                 return commit;
1220         } while (revs->commits);
1221         return NULL;
1222 }