Merge branch 'pb/web'
[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
348         if (commit->object.flags & ADDED)
349                 return;
350         commit->object.flags |= ADDED;
351
352         /*
353          * If the commit is uninteresting, don't try to
354          * prune parents - we want the maximal uninteresting
355          * set.
356          *
357          * Normally we haven't parsed the parent
358          * yet, so we won't have a parent of a parent
359          * here. However, it may turn out that we've
360          * reached this commit some other way (where it
361          * wasn't uninteresting), in which case we need
362          * to mark its parents recursively too..
363          */
364         if (commit->object.flags & UNINTERESTING) {
365                 while (parent) {
366                         struct commit *p = parent->item;
367                         parent = parent->next;
368                         parse_commit(p);
369                         p->object.flags |= UNINTERESTING;
370                         if (p->parents)
371                                 mark_parents_uninteresting(p);
372                         if (p->object.flags & SEEN)
373                                 continue;
374                         p->object.flags |= SEEN;
375                         insert_by_date(p, list);
376                 }
377                 return;
378         }
379
380         /*
381          * Ok, the commit wasn't uninteresting. Try to
382          * simplify the commit history and find the parent
383          * that has no differences in the path set if one exists.
384          */
385         if (revs->prune_fn)
386                 revs->prune_fn(revs, commit);
387
388         if (revs->no_walk)
389                 return;
390
391         parent = commit->parents;
392         while (parent) {
393                 struct commit *p = parent->item;
394
395                 parent = parent->next;
396
397                 parse_commit(p);
398                 if (p->object.flags & SEEN)
399                         continue;
400                 p->object.flags |= SEEN;
401                 insert_by_date(p, list);
402         }
403 }
404
405 static void limit_list(struct rev_info *revs)
406 {
407         struct commit_list *list = revs->commits;
408         struct commit_list *newlist = NULL;
409         struct commit_list **p = &newlist;
410
411         while (list) {
412                 struct commit_list *entry = list;
413                 struct commit *commit = list->item;
414                 struct object *obj = &commit->object;
415
416                 list = list->next;
417                 free(entry);
418
419                 if (revs->max_age != -1 && (commit->date < revs->max_age))
420                         obj->flags |= UNINTERESTING;
421                 add_parents_to_list(revs, commit, &list);
422                 if (obj->flags & UNINTERESTING) {
423                         mark_parents_uninteresting(commit);
424                         if (everybody_uninteresting(list))
425                                 break;
426                         continue;
427                 }
428                 if (revs->min_age != -1 && (commit->date > revs->min_age))
429                         continue;
430                 p = &commit_list_insert(commit, p)->next;
431         }
432         if (revs->boundary) {
433                 /* mark the ones that are on the result list first */
434                 for (list = newlist; list; list = list->next) {
435                         struct commit *commit = list->item;
436                         commit->object.flags |= TMP_MARK;
437                 }
438                 for (list = newlist; list; list = list->next) {
439                         struct commit *commit = list->item;
440                         struct object *obj = &commit->object;
441                         struct commit_list *parent;
442                         if (obj->flags & UNINTERESTING)
443                                 continue;
444                         for (parent = commit->parents;
445                              parent;
446                              parent = parent->next) {
447                                 struct commit *pcommit = parent->item;
448                                 if (!(pcommit->object.flags & UNINTERESTING))
449                                         continue;
450                                 pcommit->object.flags |= BOUNDARY;
451                                 if (pcommit->object.flags & TMP_MARK)
452                                         continue;
453                                 pcommit->object.flags |= TMP_MARK;
454                                 p = &commit_list_insert(pcommit, p)->next;
455                         }
456                 }
457                 for (list = newlist; list; list = list->next) {
458                         struct commit *commit = list->item;
459                         commit->object.flags &= ~TMP_MARK;
460                 }
461         }
462         revs->commits = newlist;
463 }
464
465 static int all_flags;
466 static struct rev_info *all_revs;
467
468 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
469 {
470         struct object *object = get_reference(all_revs, path, sha1, all_flags);
471         add_pending_object(all_revs, object, "");
472         return 0;
473 }
474
475 static void handle_all(struct rev_info *revs, unsigned flags)
476 {
477         all_revs = revs;
478         all_flags = flags;
479         for_each_ref(handle_one_ref, NULL);
480 }
481
482 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
483 {
484         unsigned char sha1[20];
485         struct object *it;
486         struct commit *commit;
487         struct commit_list *parents;
488
489         if (*arg == '^') {
490                 flags ^= UNINTERESTING;
491                 arg++;
492         }
493         if (get_sha1(arg, sha1))
494                 return 0;
495         while (1) {
496                 it = get_reference(revs, arg, sha1, 0);
497                 if (it->type != OBJ_TAG)
498                         break;
499                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
500         }
501         if (it->type != OBJ_COMMIT)
502                 return 0;
503         commit = (struct commit *)it;
504         for (parents = commit->parents; parents; parents = parents->next) {
505                 it = &parents->item->object;
506                 it->flags |= flags;
507                 add_pending_object(revs, it, arg);
508         }
509         return 1;
510 }
511
512 void init_revisions(struct rev_info *revs, const char *prefix)
513 {
514         memset(revs, 0, sizeof(*revs));
515
516         revs->abbrev = DEFAULT_ABBREV;
517         revs->ignore_merges = 1;
518         revs->simplify_history = 1;
519         revs->pruning.recursive = 1;
520         revs->pruning.add_remove = file_add_remove;
521         revs->pruning.change = file_change;
522         revs->lifo = 1;
523         revs->dense = 1;
524         revs->prefix = prefix;
525         revs->max_age = -1;
526         revs->min_age = -1;
527         revs->max_count = -1;
528
529         revs->prune_fn = NULL;
530         revs->prune_data = NULL;
531
532         revs->topo_setter = topo_sort_default_setter;
533         revs->topo_getter = topo_sort_default_getter;
534
535         revs->commit_format = CMIT_FMT_DEFAULT;
536
537         diff_setup(&revs->diffopt);
538 }
539
540 static void add_pending_commit_list(struct rev_info *revs,
541                                     struct commit_list *commit_list,
542                                     unsigned int flags)
543 {
544         while (commit_list) {
545                 struct object *object = &commit_list->item->object;
546                 object->flags |= flags;
547                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
548                 commit_list = commit_list->next;
549         }
550 }
551
552 static void prepare_show_merge(struct rev_info *revs)
553 {
554         struct commit_list *bases;
555         struct commit *head, *other;
556         unsigned char sha1[20];
557         const char **prune = NULL;
558         int i, prune_num = 1; /* counting terminating NULL */
559
560         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
561                 die("--merge without HEAD?");
562         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
563                 die("--merge without MERGE_HEAD?");
564         add_pending_object(revs, &head->object, "HEAD");
565         add_pending_object(revs, &other->object, "MERGE_HEAD");
566         bases = get_merge_bases(head, other, 1);
567         while (bases) {
568                 struct commit *it = bases->item;
569                 struct commit_list *n = bases->next;
570                 free(bases);
571                 bases = n;
572                 it->object.flags |= UNINTERESTING;
573                 add_pending_object(revs, &it->object, "(merge-base)");
574         }
575
576         if (!active_nr)
577                 read_cache();
578         for (i = 0; i < active_nr; i++) {
579                 struct cache_entry *ce = active_cache[i];
580                 if (!ce_stage(ce))
581                         continue;
582                 if (ce_path_match(ce, revs->prune_data)) {
583                         prune_num++;
584                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
585                         prune[prune_num-2] = ce->name;
586                         prune[prune_num-1] = NULL;
587                 }
588                 while ((i+1 < active_nr) &&
589                        ce_same_name(ce, active_cache[i+1]))
590                         i++;
591         }
592         revs->prune_data = prune;
593 }
594
595 int handle_revision_arg(const char *arg, struct rev_info *revs,
596                         int flags,
597                         int cant_be_filename)
598 {
599         char *dotdot;
600         struct object *object;
601         unsigned char sha1[20];
602         int local_flags;
603
604         dotdot = strstr(arg, "..");
605         if (dotdot) {
606                 unsigned char from_sha1[20];
607                 const char *next = dotdot + 2;
608                 const char *this = arg;
609                 int symmetric = *next == '.';
610                 unsigned int flags_exclude = flags ^ UNINTERESTING;
611
612                 *dotdot = 0;
613                 next += symmetric;
614
615                 if (!*next)
616                         next = "HEAD";
617                 if (dotdot == arg)
618                         this = "HEAD";
619                 if (!get_sha1(this, from_sha1) &&
620                     !get_sha1(next, sha1)) {
621                         struct commit *a, *b;
622                         struct commit_list *exclude;
623
624                         a = lookup_commit_reference(from_sha1);
625                         b = lookup_commit_reference(sha1);
626                         if (!a || !b) {
627                                 die(symmetric ?
628                                     "Invalid symmetric difference expression %s...%s" :
629                                     "Invalid revision range %s..%s",
630                                     arg, next);
631                         }
632
633                         if (!cant_be_filename) {
634                                 *dotdot = '.';
635                                 verify_non_filename(revs->prefix, arg);
636                         }
637
638                         if (symmetric) {
639                                 exclude = get_merge_bases(a, b, 1);
640                                 add_pending_commit_list(revs, exclude,
641                                                         flags_exclude);
642                                 free_commit_list(exclude);
643                                 a->object.flags |= flags;
644                         } else
645                                 a->object.flags |= flags_exclude;
646                         b->object.flags |= flags;
647                         add_pending_object(revs, &a->object, this);
648                         add_pending_object(revs, &b->object, next);
649                         return 0;
650                 }
651                 *dotdot = '.';
652         }
653         dotdot = strstr(arg, "^@");
654         if (dotdot && !dotdot[2]) {
655                 *dotdot = 0;
656                 if (add_parents_only(revs, arg, flags))
657                         return 0;
658                 *dotdot = '^';
659         }
660         local_flags = 0;
661         if (*arg == '^') {
662                 local_flags = UNINTERESTING;
663                 arg++;
664         }
665         if (get_sha1(arg, sha1))
666                 return -1;
667         if (!cant_be_filename)
668                 verify_non_filename(revs->prefix, arg);
669         object = get_reference(revs, arg, sha1, flags ^ local_flags);
670         add_pending_object(revs, object, arg);
671         return 0;
672 }
673
674 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
675 {
676         if (!revs->grep_filter) {
677                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
678                 opt->status_only = 1;
679                 opt->pattern_tail = &(opt->pattern_list);
680                 opt->regflags = REG_NEWLINE;
681                 revs->grep_filter = opt;
682         }
683         append_grep_pattern(revs->grep_filter, ptn,
684                             "command line", 0, what);
685 }
686
687 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
688 {
689         char *pat;
690         const char *prefix;
691         int patlen, fldlen;
692
693         fldlen = strlen(field);
694         patlen = strlen(pattern);
695         pat = xmalloc(patlen + fldlen + 10);
696         prefix = ".*";
697         if (*pattern == '^') {
698                 prefix = "";
699                 pattern++;
700         }
701         sprintf(pat, "^%s %s%s", field, prefix, pattern);
702         add_grep(revs, pat, GREP_PATTERN_HEAD);
703 }
704
705 static void add_message_grep(struct rev_info *revs, const char *pattern)
706 {
707         add_grep(revs, pattern, GREP_PATTERN_BODY);
708 }
709
710 static void add_ignore_packed(struct rev_info *revs, const char *name)
711 {
712         int num = ++revs->num_ignore_packed;
713
714         revs->ignore_packed = xrealloc(revs->ignore_packed,
715                                        sizeof(const char **) * (num + 1));
716         revs->ignore_packed[num-1] = name;
717         revs->ignore_packed[num] = NULL;
718 }
719
720 /*
721  * Parse revision information, filling in the "rev_info" structure,
722  * and removing the used arguments from the argument list.
723  *
724  * Returns the number of arguments left that weren't recognized
725  * (which are also moved to the head of the argument list)
726  */
727 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
728 {
729         int i, flags, seen_dashdash, show_merge;
730         const char **unrecognized = argv + 1;
731         int left = 1;
732         int all_match = 0;
733
734         /* First, search for "--" */
735         seen_dashdash = 0;
736         for (i = 1; i < argc; i++) {
737                 const char *arg = argv[i];
738                 if (strcmp(arg, "--"))
739                         continue;
740                 argv[i] = NULL;
741                 argc = i;
742                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
743                 seen_dashdash = 1;
744                 break;
745         }
746
747         flags = show_merge = 0;
748         for (i = 1; i < argc; i++) {
749                 const char *arg = argv[i];
750                 if (*arg == '-') {
751                         int opts;
752                         if (!strncmp(arg, "--max-count=", 12)) {
753                                 revs->max_count = atoi(arg + 12);
754                                 continue;
755                         }
756                         /* accept -<digit>, like traditional "head" */
757                         if ((*arg == '-') && isdigit(arg[1])) {
758                                 revs->max_count = atoi(arg + 1);
759                                 continue;
760                         }
761                         if (!strcmp(arg, "-n")) {
762                                 if (argc <= i + 1)
763                                         die("-n requires an argument");
764                                 revs->max_count = atoi(argv[++i]);
765                                 continue;
766                         }
767                         if (!strncmp(arg,"-n",2)) {
768                                 revs->max_count = atoi(arg + 2);
769                                 continue;
770                         }
771                         if (!strncmp(arg, "--max-age=", 10)) {
772                                 revs->max_age = atoi(arg + 10);
773                                 continue;
774                         }
775                         if (!strncmp(arg, "--since=", 8)) {
776                                 revs->max_age = approxidate(arg + 8);
777                                 continue;
778                         }
779                         if (!strncmp(arg, "--after=", 8)) {
780                                 revs->max_age = approxidate(arg + 8);
781                                 continue;
782                         }
783                         if (!strncmp(arg, "--min-age=", 10)) {
784                                 revs->min_age = atoi(arg + 10);
785                                 continue;
786                         }
787                         if (!strncmp(arg, "--before=", 9)) {
788                                 revs->min_age = approxidate(arg + 9);
789                                 continue;
790                         }
791                         if (!strncmp(arg, "--until=", 8)) {
792                                 revs->min_age = approxidate(arg + 8);
793                                 continue;
794                         }
795                         if (!strcmp(arg, "--all")) {
796                                 handle_all(revs, flags);
797                                 continue;
798                         }
799                         if (!strcmp(arg, "--not")) {
800                                 flags ^= UNINTERESTING;
801                                 continue;
802                         }
803                         if (!strcmp(arg, "--default")) {
804                                 if (++i >= argc)
805                                         die("bad --default argument");
806                                 def = argv[i];
807                                 continue;
808                         }
809                         if (!strcmp(arg, "--merge")) {
810                                 show_merge = 1;
811                                 continue;
812                         }
813                         if (!strcmp(arg, "--topo-order")) {
814                                 revs->topo_order = 1;
815                                 continue;
816                         }
817                         if (!strcmp(arg, "--date-order")) {
818                                 revs->lifo = 0;
819                                 revs->topo_order = 1;
820                                 continue;
821                         }
822                         if (!strcmp(arg, "--parents")) {
823                                 revs->parents = 1;
824                                 continue;
825                         }
826                         if (!strcmp(arg, "--dense")) {
827                                 revs->dense = 1;
828                                 continue;
829                         }
830                         if (!strcmp(arg, "--sparse")) {
831                                 revs->dense = 0;
832                                 continue;
833                         }
834                         if (!strcmp(arg, "--remove-empty")) {
835                                 revs->remove_empty_trees = 1;
836                                 continue;
837                         }
838                         if (!strcmp(arg, "--no-merges")) {
839                                 revs->no_merges = 1;
840                                 continue;
841                         }
842                         if (!strcmp(arg, "--boundary")) {
843                                 revs->boundary = 1;
844                                 continue;
845                         }
846                         if (!strcmp(arg, "--objects")) {
847                                 revs->tag_objects = 1;
848                                 revs->tree_objects = 1;
849                                 revs->blob_objects = 1;
850                                 continue;
851                         }
852                         if (!strcmp(arg, "--objects-edge")) {
853                                 revs->tag_objects = 1;
854                                 revs->tree_objects = 1;
855                                 revs->blob_objects = 1;
856                                 revs->edge_hint = 1;
857                                 continue;
858                         }
859                         if (!strcmp(arg, "--unpacked")) {
860                                 revs->unpacked = 1;
861                                 free(revs->ignore_packed);
862                                 revs->ignore_packed = NULL;
863                                 revs->num_ignore_packed = 0;
864                                 continue;
865                         }
866                         if (!strncmp(arg, "--unpacked=", 11)) {
867                                 revs->unpacked = 1;
868                                 add_ignore_packed(revs, arg+11);
869                                 continue;
870                         }
871                         if (!strcmp(arg, "-r")) {
872                                 revs->diff = 1;
873                                 revs->diffopt.recursive = 1;
874                                 continue;
875                         }
876                         if (!strcmp(arg, "-t")) {
877                                 revs->diff = 1;
878                                 revs->diffopt.recursive = 1;
879                                 revs->diffopt.tree_in_recursive = 1;
880                                 continue;
881                         }
882                         if (!strcmp(arg, "-m")) {
883                                 revs->ignore_merges = 0;
884                                 continue;
885                         }
886                         if (!strcmp(arg, "-c")) {
887                                 revs->diff = 1;
888                                 revs->dense_combined_merges = 0;
889                                 revs->combine_merges = 1;
890                                 continue;
891                         }
892                         if (!strcmp(arg, "--cc")) {
893                                 revs->diff = 1;
894                                 revs->dense_combined_merges = 1;
895                                 revs->combine_merges = 1;
896                                 continue;
897                         }
898                         if (!strcmp(arg, "-v")) {
899                                 revs->verbose_header = 1;
900                                 continue;
901                         }
902                         if (!strncmp(arg, "--pretty", 8)) {
903                                 revs->verbose_header = 1;
904                                 revs->commit_format = get_commit_format(arg+8);
905                                 continue;
906                         }
907                         if (!strcmp(arg, "--root")) {
908                                 revs->show_root_diff = 1;
909                                 continue;
910                         }
911                         if (!strcmp(arg, "--no-commit-id")) {
912                                 revs->no_commit_id = 1;
913                                 continue;
914                         }
915                         if (!strcmp(arg, "--always")) {
916                                 revs->always_show_header = 1;
917                                 continue;
918                         }
919                         if (!strcmp(arg, "--no-abbrev")) {
920                                 revs->abbrev = 0;
921                                 continue;
922                         }
923                         if (!strcmp(arg, "--abbrev")) {
924                                 revs->abbrev = DEFAULT_ABBREV;
925                                 continue;
926                         }
927                         if (!strncmp(arg, "--abbrev=", 9)) {
928                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
929                                 if (revs->abbrev < MINIMUM_ABBREV)
930                                         revs->abbrev = MINIMUM_ABBREV;
931                                 else if (revs->abbrev > 40)
932                                         revs->abbrev = 40;
933                                 continue;
934                         }
935                         if (!strcmp(arg, "--abbrev-commit")) {
936                                 revs->abbrev_commit = 1;
937                                 continue;
938                         }
939                         if (!strcmp(arg, "--full-diff")) {
940                                 revs->diff = 1;
941                                 revs->full_diff = 1;
942                                 continue;
943                         }
944                         if (!strcmp(arg, "--full-history")) {
945                                 revs->simplify_history = 0;
946                                 continue;
947                         }
948                         if (!strcmp(arg, "--relative-date")) {
949                                 revs->relative_date = 1;
950                                 continue;
951                         }
952
953                         /*
954                          * Grepping the commit log
955                          */
956                         if (!strncmp(arg, "--author=", 9)) {
957                                 add_header_grep(revs, "author", arg+9);
958                                 continue;
959                         }
960                         if (!strncmp(arg, "--committer=", 12)) {
961                                 add_header_grep(revs, "committer", arg+12);
962                                 continue;
963                         }
964                         if (!strncmp(arg, "--grep=", 7)) {
965                                 add_message_grep(revs, arg+7);
966                                 continue;
967                         }
968                         if (!strcmp(arg, "--all-match")) {
969                                 all_match = 1;
970                                 continue;
971                         }
972
973                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
974                         if (opts > 0) {
975                                 revs->diff = 1;
976                                 i += opts - 1;
977                                 continue;
978                         }
979                         *unrecognized++ = arg;
980                         left++;
981                         continue;
982                 }
983
984                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
985                         int j;
986                         if (seen_dashdash || *arg == '^')
987                                 die("bad revision '%s'", arg);
988
989                         /* If we didn't have a "--":
990                          * (1) all filenames must exist;
991                          * (2) all rev-args must not be interpretable
992                          *     as a valid filename.
993                          * but the latter we have checked in the main loop.
994                          */
995                         for (j = i; j < argc; j++)
996                                 verify_filename(revs->prefix, argv[j]);
997
998                         revs->prune_data = get_pathspec(revs->prefix,
999                                                         argv + i);
1000                         break;
1001                 }
1002         }
1003
1004         if (show_merge)
1005                 prepare_show_merge(revs);
1006         if (def && !revs->pending.nr) {
1007                 unsigned char sha1[20];
1008                 struct object *object;
1009                 if (get_sha1(def, sha1))
1010                         die("bad default revision '%s'", def);
1011                 object = get_reference(revs, def, sha1, 0);
1012                 add_pending_object(revs, object, def);
1013         }
1014
1015         if (revs->topo_order)
1016                 revs->limited = 1;
1017
1018         if (revs->prune_data) {
1019                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1020                 revs->prune_fn = try_to_simplify_commit;
1021                 if (!revs->full_diff)
1022                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1023         }
1024         if (revs->combine_merges) {
1025                 revs->ignore_merges = 0;
1026                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1027                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1028         }
1029         revs->diffopt.abbrev = revs->abbrev;
1030         if (diff_setup_done(&revs->diffopt) < 0)
1031                 die("diff_setup_done failed");
1032
1033         if (revs->grep_filter) {
1034                 revs->grep_filter->all_match = all_match;
1035                 compile_grep_patterns(revs->grep_filter);
1036         }
1037
1038         return left;
1039 }
1040
1041 void prepare_revision_walk(struct rev_info *revs)
1042 {
1043         int nr = revs->pending.nr;
1044         struct object_array_entry *list = revs->pending.objects;
1045
1046         revs->pending.nr = 0;
1047         revs->pending.alloc = 0;
1048         revs->pending.objects = NULL;
1049         while (--nr >= 0) {
1050                 struct commit *commit = handle_commit(revs, list->item, list->name);
1051                 if (commit) {
1052                         if (!(commit->object.flags & SEEN)) {
1053                                 commit->object.flags |= SEEN;
1054                                 insert_by_date(commit, &revs->commits);
1055                         }
1056                 }
1057                 list++;
1058         }
1059
1060         if (revs->no_walk)
1061                 return;
1062         if (revs->limited)
1063                 limit_list(revs);
1064         if (revs->topo_order)
1065                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1066                                              revs->topo_setter,
1067                                              revs->topo_getter);
1068 }
1069
1070 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1071 {
1072         for (;;) {
1073                 struct commit *p = *pp;
1074                 if (!revs->limited)
1075                         add_parents_to_list(revs, p, &revs->commits);
1076                 if (p->parents && p->parents->next)
1077                         return 0;
1078                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1079                         return 0;
1080                 if (!p->parents)
1081                         return -1;
1082                 *pp = p->parents->item;
1083         }
1084 }
1085
1086 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1087 {
1088         struct commit_list **pp = &commit->parents;
1089         while (*pp) {
1090                 struct commit_list *parent = *pp;
1091                 if (rewrite_one(revs, &parent->item) < 0) {
1092                         *pp = parent->next;
1093                         continue;
1094                 }
1095                 pp = &parent->next;
1096         }
1097 }
1098
1099 static void mark_boundary_to_show(struct commit *commit)
1100 {
1101         struct commit_list *p = commit->parents;
1102         while (p) {
1103                 commit = p->item;
1104                 p = p->next;
1105                 if (commit->object.flags & BOUNDARY)
1106                         commit->object.flags |= BOUNDARY_SHOW;
1107         }
1108 }
1109
1110 static int commit_match(struct commit *commit, struct rev_info *opt)
1111 {
1112         if (!opt->grep_filter)
1113                 return 1;
1114         return grep_buffer(opt->grep_filter,
1115                            NULL, /* we say nothing, not even filename */
1116                            commit->buffer, strlen(commit->buffer));
1117 }
1118
1119 struct commit *get_revision(struct rev_info *revs)
1120 {
1121         struct commit_list *list = revs->commits;
1122
1123         if (!list)
1124                 return NULL;
1125
1126         /* Check the max_count ... */
1127         switch (revs->max_count) {
1128         case -1:
1129                 break;
1130         case 0:
1131                 return NULL;
1132         default:
1133                 revs->max_count--;
1134         }
1135
1136         do {
1137                 struct commit_list *entry = revs->commits;
1138                 struct commit *commit = entry->item;
1139
1140                 revs->commits = entry->next;
1141                 free(entry);
1142
1143                 /*
1144                  * If we haven't done the list limiting, we need to look at
1145                  * the parents here. We also need to do the date-based limiting
1146                  * that we'd otherwise have done in limit_list().
1147                  */
1148                 if (!revs->limited) {
1149                         if (revs->max_age != -1 &&
1150                             (commit->date < revs->max_age))
1151                                 continue;
1152                         add_parents_to_list(revs, commit, &revs->commits);
1153                 }
1154                 if (commit->object.flags & SHOWN)
1155                         continue;
1156
1157                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1158                                                     revs->ignore_packed))
1159                     continue;
1160
1161                 /* We want to show boundary commits only when their
1162                  * children are shown.  When path-limiter is in effect,
1163                  * rewrite_parents() drops some commits from getting shown,
1164                  * and there is no point showing boundary parents that
1165                  * are not shown.  After rewrite_parents() rewrites the
1166                  * parents of a commit that is shown, we mark the boundary
1167                  * parents with BOUNDARY_SHOW.
1168                  */
1169                 if (commit->object.flags & BOUNDARY_SHOW) {
1170                         commit->object.flags |= SHOWN;
1171                         return commit;
1172                 }
1173                 if (commit->object.flags & UNINTERESTING)
1174                         continue;
1175                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1176                         continue;
1177                 if (revs->no_merges &&
1178                     commit->parents && commit->parents->next)
1179                         continue;
1180                 if (!commit_match(commit, revs))
1181                         continue;
1182                 if (revs->prune_fn && revs->dense) {
1183                         /* Commit without changes? */
1184                         if (!(commit->object.flags & TREECHANGE)) {
1185                                 /* drop merges unless we want parenthood */
1186                                 if (!revs->parents)
1187                                         continue;
1188                                 /* non-merge - always ignore it */
1189                                 if (!commit->parents || !commit->parents->next)
1190                                         continue;
1191                         }
1192                         if (revs->parents)
1193                                 rewrite_parents(revs, commit);
1194                 }
1195                 if (revs->boundary)
1196                         mark_boundary_to_show(commit);
1197                 commit->object.flags |= SHOWN;
1198                 return commit;
1199         } while (revs->commits);
1200         return NULL;
1201 }