sha1_file.c: cleanup hdr usage
[git] / revision.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "refs.h"
8 #include "revision.h"
9 #include "grep.h"
10 #include "reflog-walk.h"
11
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         if (revs->reflog_info && obj->type == OBJ_COMMIT)
121                 add_reflog_for_walk(revs->reflog_info,
122                                 (struct commit *)obj, name);
123 }
124
125 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
126 {
127         struct object *object;
128
129         object = parse_object(sha1);
130         if (!object)
131                 die("bad object %s", name);
132         object->flags |= flags;
133         return object;
134 }
135
136 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
137 {
138         unsigned long flags = object->flags;
139
140         /*
141          * Tag object? Look what it points to..
142          */
143         while (object->type == OBJ_TAG) {
144                 struct tag *tag = (struct tag *) object;
145                 if (revs->tag_objects && !(flags & UNINTERESTING))
146                         add_pending_object(revs, object, tag->tag);
147                 object = parse_object(tag->tagged->sha1);
148                 if (!object)
149                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
150         }
151
152         /*
153          * Commit object? Just return it, we'll do all the complex
154          * reachability crud.
155          */
156         if (object->type == OBJ_COMMIT) {
157                 struct commit *commit = (struct commit *)object;
158                 if (parse_commit(commit) < 0)
159                         die("unable to parse commit %s", name);
160                 if (flags & UNINTERESTING) {
161                         commit->object.flags |= UNINTERESTING;
162                         mark_parents_uninteresting(commit);
163                         revs->limited = 1;
164                 }
165                 return commit;
166         }
167
168         /*
169          * Tree object? Either mark it uniniteresting, or add it
170          * to the list of objects to look at later..
171          */
172         if (object->type == OBJ_TREE) {
173                 struct tree *tree = (struct tree *)object;
174                 if (!revs->tree_objects)
175                         return NULL;
176                 if (flags & UNINTERESTING) {
177                         mark_tree_uninteresting(tree);
178                         return NULL;
179                 }
180                 add_pending_object(revs, object, "");
181                 return NULL;
182         }
183
184         /*
185          * Blob object? You know the drill by now..
186          */
187         if (object->type == OBJ_BLOB) {
188                 struct blob *blob = (struct blob *)object;
189                 if (!revs->blob_objects)
190                         return NULL;
191                 if (flags & UNINTERESTING) {
192                         mark_blob_uninteresting(blob);
193                         return NULL;
194                 }
195                 add_pending_object(revs, object, "");
196                 return NULL;
197         }
198         die("%s is unknown object", name);
199 }
200
201 static int everybody_uninteresting(struct commit_list *orig)
202 {
203         struct commit_list *list = orig;
204         while (list) {
205                 struct commit *commit = list->item;
206                 list = list->next;
207                 if (commit->object.flags & UNINTERESTING)
208                         continue;
209                 return 0;
210         }
211         return 1;
212 }
213
214 static int tree_difference = REV_TREE_SAME;
215
216 static void file_add_remove(struct diff_options *options,
217                     int addremove, unsigned mode,
218                     const unsigned char *sha1,
219                     const char *base, const char *path)
220 {
221         int diff = REV_TREE_DIFFERENT;
222
223         /*
224          * Is it an add of a new file? It means that the old tree
225          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
226          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
227          * (and if it already was "REV_TREE_NEW", we'll keep it
228          * "REV_TREE_NEW" of course).
229          */
230         if (addremove == '+') {
231                 diff = tree_difference;
232                 if (diff != REV_TREE_SAME)
233                         return;
234                 diff = REV_TREE_NEW;
235         }
236         tree_difference = diff;
237 }
238
239 static void file_change(struct diff_options *options,
240                  unsigned old_mode, unsigned new_mode,
241                  const unsigned char *old_sha1,
242                  const unsigned char *new_sha1,
243                  const char *base, const char *path)
244 {
245         tree_difference = REV_TREE_DIFFERENT;
246 }
247
248 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
249 {
250         if (!t1)
251                 return REV_TREE_NEW;
252         if (!t2)
253                 return REV_TREE_DIFFERENT;
254         tree_difference = REV_TREE_SAME;
255         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
256                            &revs->pruning) < 0)
257                 return REV_TREE_DIFFERENT;
258         return tree_difference;
259 }
260
261 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
262 {
263         int retval;
264         void *tree;
265         struct tree_desc empty, real;
266
267         if (!t1)
268                 return 0;
269
270         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
271         if (!tree)
272                 return 0;
273         real.buf = tree;
274
275         empty.buf = "";
276         empty.size = 0;
277
278         tree_difference = 0;
279         retval = diff_tree(&empty, &real, "", &revs->pruning);
280         free(tree);
281
282         return retval >= 0 && !tree_difference;
283 }
284
285 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
286 {
287         struct commit_list **pp, *parent;
288         int tree_changed = 0, tree_same = 0;
289
290         if (!commit->tree)
291                 return;
292
293         if (!commit->parents) {
294                 if (!rev_same_tree_as_empty(revs, commit->tree))
295                         commit->object.flags |= TREECHANGE;
296                 return;
297         }
298
299         pp = &commit->parents;
300         while ((parent = *pp) != NULL) {
301                 struct commit *p = parent->item;
302
303                 parse_commit(p);
304                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
305                 case REV_TREE_SAME:
306                         tree_same = 1;
307                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
308                                 /* Even if a merge with an uninteresting
309                                  * side branch brought the entire change
310                                  * we are interested in, we do not want
311                                  * to lose the other branches of this
312                                  * merge, so we just keep going.
313                                  */
314                                 pp = &parent->next;
315                                 continue;
316                         }
317                         parent->next = NULL;
318                         commit->parents = parent;
319                         return;
320
321                 case REV_TREE_NEW:
322                         if (revs->remove_empty_trees &&
323                             rev_same_tree_as_empty(revs, p->tree)) {
324                                 /* We are adding all the specified
325                                  * paths from this parent, so the
326                                  * history beyond this parent is not
327                                  * interesting.  Remove its parents
328                                  * (they are grandparents for us).
329                                  * IOW, we pretend this parent is a
330                                  * "root" commit.
331                                  */
332                                 parse_commit(p);
333                                 p->parents = NULL;
334                         }
335                 /* fallthrough */
336                 case REV_TREE_DIFFERENT:
337                         tree_changed = 1;
338                         pp = &parent->next;
339                         continue;
340                 }
341                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
342         }
343         if (tree_changed && !tree_same)
344                 commit->object.flags |= TREECHANGE;
345 }
346
347 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
348 {
349         struct commit_list *parent = commit->parents;
350         unsigned left_flag;
351
352         if (commit->object.flags & ADDED)
353                 return;
354         commit->object.flags |= ADDED;
355
356         /*
357          * If the commit is uninteresting, don't try to
358          * prune parents - we want the maximal uninteresting
359          * set.
360          *
361          * Normally we haven't parsed the parent
362          * yet, so we won't have a parent of a parent
363          * here. However, it may turn out that we've
364          * reached this commit some other way (where it
365          * wasn't uninteresting), in which case we need
366          * to mark its parents recursively too..
367          */
368         if (commit->object.flags & UNINTERESTING) {
369                 while (parent) {
370                         struct commit *p = parent->item;
371                         parent = parent->next;
372                         parse_commit(p);
373                         p->object.flags |= UNINTERESTING;
374                         if (p->parents)
375                                 mark_parents_uninteresting(p);
376                         if (p->object.flags & SEEN)
377                                 continue;
378                         p->object.flags |= SEEN;
379                         insert_by_date(p, list);
380                 }
381                 return;
382         }
383
384         /*
385          * Ok, the commit wasn't uninteresting. Try to
386          * simplify the commit history and find the parent
387          * that has no differences in the path set if one exists.
388          */
389         if (revs->prune_fn)
390                 revs->prune_fn(revs, commit);
391
392         if (revs->no_walk)
393                 return;
394
395         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
396         parent = commit->parents;
397         while (parent) {
398                 struct commit *p = parent->item;
399
400                 parent = parent->next;
401
402                 parse_commit(p);
403                 p->object.flags |= left_flag;
404                 if (p->object.flags & SEEN)
405                         continue;
406                 p->object.flags |= SEEN;
407                 insert_by_date(p, list);
408         }
409 }
410
411 static void limit_list(struct rev_info *revs)
412 {
413         struct commit_list *list = revs->commits;
414         struct commit_list *newlist = NULL;
415         struct commit_list **p = &newlist;
416
417         while (list) {
418                 struct commit_list *entry = list;
419                 struct commit *commit = list->item;
420                 struct object *obj = &commit->object;
421
422                 list = list->next;
423                 free(entry);
424
425                 if (revs->max_age != -1 && (commit->date < revs->max_age))
426                         obj->flags |= UNINTERESTING;
427                 add_parents_to_list(revs, commit, &list);
428                 if (obj->flags & UNINTERESTING) {
429                         mark_parents_uninteresting(commit);
430                         if (everybody_uninteresting(list))
431                                 break;
432                         continue;
433                 }
434                 if (revs->min_age != -1 && (commit->date > revs->min_age))
435                         continue;
436                 p = &commit_list_insert(commit, p)->next;
437         }
438         if (revs->boundary) {
439                 /* mark the ones that are on the result list first */
440                 for (list = newlist; list; list = list->next) {
441                         struct commit *commit = list->item;
442                         commit->object.flags |= TMP_MARK;
443                 }
444                 for (list = newlist; list; list = list->next) {
445                         struct commit *commit = list->item;
446                         struct object *obj = &commit->object;
447                         struct commit_list *parent;
448                         if (obj->flags & UNINTERESTING)
449                                 continue;
450                         for (parent = commit->parents;
451                              parent;
452                              parent = parent->next) {
453                                 struct commit *pcommit = parent->item;
454                                 if (!(pcommit->object.flags & UNINTERESTING))
455                                         continue;
456                                 pcommit->object.flags |= BOUNDARY;
457                                 if (pcommit->object.flags & TMP_MARK)
458                                         continue;
459                                 pcommit->object.flags |= TMP_MARK;
460                                 p = &commit_list_insert(pcommit, p)->next;
461                         }
462                 }
463                 for (list = newlist; list; list = list->next) {
464                         struct commit *commit = list->item;
465                         commit->object.flags &= ~TMP_MARK;
466                 }
467         }
468         revs->commits = newlist;
469 }
470
471 struct all_refs_cb {
472         int all_flags;
473         int warned_bad_reflog;
474         struct rev_info *all_revs;
475         const char *name_for_errormsg;
476 };
477
478 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
479 {
480         struct all_refs_cb *cb = cb_data;
481         struct object *object = get_reference(cb->all_revs, path, sha1,
482                                               cb->all_flags);
483         add_pending_object(cb->all_revs, object, "");
484         return 0;
485 }
486
487 static void handle_all(struct rev_info *revs, unsigned flags)
488 {
489         struct all_refs_cb cb;
490         cb.all_revs = revs;
491         cb.all_flags = flags;
492         for_each_ref(handle_one_ref, &cb);
493 }
494
495 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
496 {
497         struct all_refs_cb *cb = cb_data;
498         if (!is_null_sha1(sha1)) {
499                 struct object *o = parse_object(sha1);
500                 if (o) {
501                         o->flags |= cb->all_flags;
502                         add_pending_object(cb->all_revs, o, "");
503                 }
504                 else if (!cb->warned_bad_reflog) {
505                         warn("reflog of '%s' references pruned commits",
506                                 cb->name_for_errormsg);
507                         cb->warned_bad_reflog = 1;
508                 }
509         }
510 }
511
512 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
513                 const char *email, unsigned long timestamp, int tz,
514                 const char *message, void *cb_data)
515 {
516         handle_one_reflog_commit(osha1, cb_data);
517         handle_one_reflog_commit(nsha1, cb_data);
518         return 0;
519 }
520
521 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
522 {
523         struct all_refs_cb *cb = cb_data;
524         cb->warned_bad_reflog = 0;
525         cb->name_for_errormsg = path;
526         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
527         return 0;
528 }
529
530 static void handle_reflog(struct rev_info *revs, unsigned flags)
531 {
532         struct all_refs_cb cb;
533         cb.all_revs = revs;
534         cb.all_flags = flags;
535         for_each_reflog(handle_one_reflog, &cb);
536 }
537
538 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
539 {
540         unsigned char sha1[20];
541         struct object *it;
542         struct commit *commit;
543         struct commit_list *parents;
544
545         if (*arg == '^') {
546                 flags ^= UNINTERESTING;
547                 arg++;
548         }
549         if (get_sha1(arg, sha1))
550                 return 0;
551         while (1) {
552                 it = get_reference(revs, arg, sha1, 0);
553                 if (it->type != OBJ_TAG)
554                         break;
555                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
556         }
557         if (it->type != OBJ_COMMIT)
558                 return 0;
559         commit = (struct commit *)it;
560         for (parents = commit->parents; parents; parents = parents->next) {
561                 it = &parents->item->object;
562                 it->flags |= flags;
563                 add_pending_object(revs, it, arg);
564         }
565         return 1;
566 }
567
568 void init_revisions(struct rev_info *revs, const char *prefix)
569 {
570         memset(revs, 0, sizeof(*revs));
571
572         revs->abbrev = DEFAULT_ABBREV;
573         revs->ignore_merges = 1;
574         revs->simplify_history = 1;
575         revs->pruning.recursive = 1;
576         revs->pruning.add_remove = file_add_remove;
577         revs->pruning.change = file_change;
578         revs->lifo = 1;
579         revs->dense = 1;
580         revs->prefix = prefix;
581         revs->max_age = -1;
582         revs->min_age = -1;
583         revs->skip_count = -1;
584         revs->max_count = -1;
585
586         revs->prune_fn = NULL;
587         revs->prune_data = NULL;
588
589         revs->topo_setter = topo_sort_default_setter;
590         revs->topo_getter = topo_sort_default_getter;
591
592         revs->commit_format = CMIT_FMT_DEFAULT;
593
594         diff_setup(&revs->diffopt);
595 }
596
597 static void add_pending_commit_list(struct rev_info *revs,
598                                     struct commit_list *commit_list,
599                                     unsigned int flags)
600 {
601         while (commit_list) {
602                 struct object *object = &commit_list->item->object;
603                 object->flags |= flags;
604                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
605                 commit_list = commit_list->next;
606         }
607 }
608
609 static void prepare_show_merge(struct rev_info *revs)
610 {
611         struct commit_list *bases;
612         struct commit *head, *other;
613         unsigned char sha1[20];
614         const char **prune = NULL;
615         int i, prune_num = 1; /* counting terminating NULL */
616
617         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
618                 die("--merge without HEAD?");
619         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
620                 die("--merge without MERGE_HEAD?");
621         add_pending_object(revs, &head->object, "HEAD");
622         add_pending_object(revs, &other->object, "MERGE_HEAD");
623         bases = get_merge_bases(head, other, 1);
624         while (bases) {
625                 struct commit *it = bases->item;
626                 struct commit_list *n = bases->next;
627                 free(bases);
628                 bases = n;
629                 it->object.flags |= UNINTERESTING;
630                 add_pending_object(revs, &it->object, "(merge-base)");
631         }
632
633         if (!active_nr)
634                 read_cache();
635         for (i = 0; i < active_nr; i++) {
636                 struct cache_entry *ce = active_cache[i];
637                 if (!ce_stage(ce))
638                         continue;
639                 if (ce_path_match(ce, revs->prune_data)) {
640                         prune_num++;
641                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
642                         prune[prune_num-2] = ce->name;
643                         prune[prune_num-1] = NULL;
644                 }
645                 while ((i+1 < active_nr) &&
646                        ce_same_name(ce, active_cache[i+1]))
647                         i++;
648         }
649         revs->prune_data = prune;
650 }
651
652 int handle_revision_arg(const char *arg, struct rev_info *revs,
653                         int flags,
654                         int cant_be_filename)
655 {
656         char *dotdot;
657         struct object *object;
658         unsigned char sha1[20];
659         int local_flags;
660
661         dotdot = strstr(arg, "..");
662         if (dotdot) {
663                 unsigned char from_sha1[20];
664                 const char *next = dotdot + 2;
665                 const char *this = arg;
666                 int symmetric = *next == '.';
667                 unsigned int flags_exclude = flags ^ UNINTERESTING;
668
669                 *dotdot = 0;
670                 next += symmetric;
671
672                 if (!*next)
673                         next = "HEAD";
674                 if (dotdot == arg)
675                         this = "HEAD";
676                 if (!get_sha1(this, from_sha1) &&
677                     !get_sha1(next, sha1)) {
678                         struct commit *a, *b;
679                         struct commit_list *exclude;
680
681                         a = lookup_commit_reference(from_sha1);
682                         b = lookup_commit_reference(sha1);
683                         if (!a || !b) {
684                                 die(symmetric ?
685                                     "Invalid symmetric difference expression %s...%s" :
686                                     "Invalid revision range %s..%s",
687                                     arg, next);
688                         }
689
690                         if (!cant_be_filename) {
691                                 *dotdot = '.';
692                                 verify_non_filename(revs->prefix, arg);
693                         }
694
695                         if (symmetric) {
696                                 exclude = get_merge_bases(a, b, 1);
697                                 add_pending_commit_list(revs, exclude,
698                                                         flags_exclude);
699                                 free_commit_list(exclude);
700                                 a->object.flags |= flags | SYMMETRIC_LEFT;
701                         } else
702                                 a->object.flags |= flags_exclude;
703                         b->object.flags |= flags;
704                         add_pending_object(revs, &a->object, this);
705                         add_pending_object(revs, &b->object, next);
706                         return 0;
707                 }
708                 *dotdot = '.';
709         }
710         dotdot = strstr(arg, "^@");
711         if (dotdot && !dotdot[2]) {
712                 *dotdot = 0;
713                 if (add_parents_only(revs, arg, flags))
714                         return 0;
715                 *dotdot = '^';
716         }
717         dotdot = strstr(arg, "^!");
718         if (dotdot && !dotdot[2]) {
719                 *dotdot = 0;
720                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
721                         *dotdot = '^';
722         }
723
724         local_flags = 0;
725         if (*arg == '^') {
726                 local_flags = UNINTERESTING;
727                 arg++;
728         }
729         if (get_sha1(arg, sha1))
730                 return -1;
731         if (!cant_be_filename)
732                 verify_non_filename(revs->prefix, arg);
733         object = get_reference(revs, arg, sha1, flags ^ local_flags);
734         add_pending_object(revs, object, arg);
735         return 0;
736 }
737
738 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
739 {
740         if (!revs->grep_filter) {
741                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
742                 opt->status_only = 1;
743                 opt->pattern_tail = &(opt->pattern_list);
744                 opt->regflags = REG_NEWLINE;
745                 revs->grep_filter = opt;
746         }
747         append_grep_pattern(revs->grep_filter, ptn,
748                             "command line", 0, what);
749 }
750
751 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
752 {
753         char *pat;
754         const char *prefix;
755         int patlen, fldlen;
756
757         fldlen = strlen(field);
758         patlen = strlen(pattern);
759         pat = xmalloc(patlen + fldlen + 10);
760         prefix = ".*";
761         if (*pattern == '^') {
762                 prefix = "";
763                 pattern++;
764         }
765         sprintf(pat, "^%s %s%s", field, prefix, pattern);
766         add_grep(revs, pat, GREP_PATTERN_HEAD);
767 }
768
769 static void add_message_grep(struct rev_info *revs, const char *pattern)
770 {
771         add_grep(revs, pattern, GREP_PATTERN_BODY);
772 }
773
774 static void add_ignore_packed(struct rev_info *revs, const char *name)
775 {
776         int num = ++revs->num_ignore_packed;
777
778         revs->ignore_packed = xrealloc(revs->ignore_packed,
779                                        sizeof(const char **) * (num + 1));
780         revs->ignore_packed[num-1] = name;
781         revs->ignore_packed[num] = NULL;
782 }
783
784 /*
785  * Parse revision information, filling in the "rev_info" structure,
786  * and removing the used arguments from the argument list.
787  *
788  * Returns the number of arguments left that weren't recognized
789  * (which are also moved to the head of the argument list)
790  */
791 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
792 {
793         int i, flags, seen_dashdash, show_merge;
794         const char **unrecognized = argv + 1;
795         int left = 1;
796         int all_match = 0;
797
798         /* First, search for "--" */
799         seen_dashdash = 0;
800         for (i = 1; i < argc; i++) {
801                 const char *arg = argv[i];
802                 if (strcmp(arg, "--"))
803                         continue;
804                 argv[i] = NULL;
805                 argc = i;
806                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
807                 seen_dashdash = 1;
808                 break;
809         }
810
811         flags = show_merge = 0;
812         for (i = 1; i < argc; i++) {
813                 const char *arg = argv[i];
814                 if (*arg == '-') {
815                         int opts;
816                         if (!prefixcmp(arg, "--max-count=")) {
817                                 revs->max_count = atoi(arg + 12);
818                                 continue;
819                         }
820                         if (!prefixcmp(arg, "--skip=")) {
821                                 revs->skip_count = atoi(arg + 7);
822                                 continue;
823                         }
824                         /* accept -<digit>, like traditional "head" */
825                         if ((*arg == '-') && isdigit(arg[1])) {
826                                 revs->max_count = atoi(arg + 1);
827                                 continue;
828                         }
829                         if (!strcmp(arg, "-n")) {
830                                 if (argc <= i + 1)
831                                         die("-n requires an argument");
832                                 revs->max_count = atoi(argv[++i]);
833                                 continue;
834                         }
835                         if (!prefixcmp(arg, "-n")) {
836                                 revs->max_count = atoi(arg + 2);
837                                 continue;
838                         }
839                         if (!prefixcmp(arg, "--max-age=")) {
840                                 revs->max_age = atoi(arg + 10);
841                                 continue;
842                         }
843                         if (!prefixcmp(arg, "--since=")) {
844                                 revs->max_age = approxidate(arg + 8);
845                                 continue;
846                         }
847                         if (!prefixcmp(arg, "--after=")) {
848                                 revs->max_age = approxidate(arg + 8);
849                                 continue;
850                         }
851                         if (!prefixcmp(arg, "--min-age=")) {
852                                 revs->min_age = atoi(arg + 10);
853                                 continue;
854                         }
855                         if (!prefixcmp(arg, "--before=")) {
856                                 revs->min_age = approxidate(arg + 9);
857                                 continue;
858                         }
859                         if (!prefixcmp(arg, "--until=")) {
860                                 revs->min_age = approxidate(arg + 8);
861                                 continue;
862                         }
863                         if (!strcmp(arg, "--all")) {
864                                 handle_all(revs, flags);
865                                 continue;
866                         }
867                         if (!strcmp(arg, "--reflog")) {
868                                 handle_reflog(revs, flags);
869                                 continue;
870                         }
871                         if (!strcmp(arg, "-g") ||
872                                         !strcmp(arg, "--walk-reflogs")) {
873                                 init_reflog_walk(&revs->reflog_info);
874                                 continue;
875                         }
876                         if (!strcmp(arg, "--not")) {
877                                 flags ^= UNINTERESTING;
878                                 continue;
879                         }
880                         if (!strcmp(arg, "--default")) {
881                                 if (++i >= argc)
882                                         die("bad --default argument");
883                                 def = argv[i];
884                                 continue;
885                         }
886                         if (!strcmp(arg, "--merge")) {
887                                 show_merge = 1;
888                                 continue;
889                         }
890                         if (!strcmp(arg, "--topo-order")) {
891                                 revs->topo_order = 1;
892                                 continue;
893                         }
894                         if (!strcmp(arg, "--date-order")) {
895                                 revs->lifo = 0;
896                                 revs->topo_order = 1;
897                                 continue;
898                         }
899                         if (!strcmp(arg, "--parents")) {
900                                 revs->parents = 1;
901                                 continue;
902                         }
903                         if (!strcmp(arg, "--dense")) {
904                                 revs->dense = 1;
905                                 continue;
906                         }
907                         if (!strcmp(arg, "--sparse")) {
908                                 revs->dense = 0;
909                                 continue;
910                         }
911                         if (!strcmp(arg, "--remove-empty")) {
912                                 revs->remove_empty_trees = 1;
913                                 continue;
914                         }
915                         if (!strcmp(arg, "--no-merges")) {
916                                 revs->no_merges = 1;
917                                 continue;
918                         }
919                         if (!strcmp(arg, "--boundary")) {
920                                 revs->boundary = 1;
921                                 continue;
922                         }
923                         if (!strcmp(arg, "--left-right")) {
924                                 revs->left_right = 1;
925                                 continue;
926                         }
927                         if (!strcmp(arg, "--objects")) {
928                                 revs->tag_objects = 1;
929                                 revs->tree_objects = 1;
930                                 revs->blob_objects = 1;
931                                 continue;
932                         }
933                         if (!strcmp(arg, "--objects-edge")) {
934                                 revs->tag_objects = 1;
935                                 revs->tree_objects = 1;
936                                 revs->blob_objects = 1;
937                                 revs->edge_hint = 1;
938                                 continue;
939                         }
940                         if (!strcmp(arg, "--unpacked")) {
941                                 revs->unpacked = 1;
942                                 free(revs->ignore_packed);
943                                 revs->ignore_packed = NULL;
944                                 revs->num_ignore_packed = 0;
945                                 continue;
946                         }
947                         if (!prefixcmp(arg, "--unpacked=")) {
948                                 revs->unpacked = 1;
949                                 add_ignore_packed(revs, arg+11);
950                                 continue;
951                         }
952                         if (!strcmp(arg, "-r")) {
953                                 revs->diff = 1;
954                                 revs->diffopt.recursive = 1;
955                                 continue;
956                         }
957                         if (!strcmp(arg, "-t")) {
958                                 revs->diff = 1;
959                                 revs->diffopt.recursive = 1;
960                                 revs->diffopt.tree_in_recursive = 1;
961                                 continue;
962                         }
963                         if (!strcmp(arg, "-m")) {
964                                 revs->ignore_merges = 0;
965                                 continue;
966                         }
967                         if (!strcmp(arg, "-c")) {
968                                 revs->diff = 1;
969                                 revs->dense_combined_merges = 0;
970                                 revs->combine_merges = 1;
971                                 continue;
972                         }
973                         if (!strcmp(arg, "--cc")) {
974                                 revs->diff = 1;
975                                 revs->dense_combined_merges = 1;
976                                 revs->combine_merges = 1;
977                                 continue;
978                         }
979                         if (!strcmp(arg, "-v")) {
980                                 revs->verbose_header = 1;
981                                 continue;
982                         }
983                         if (!prefixcmp(arg, "--pretty")) {
984                                 revs->verbose_header = 1;
985                                 revs->commit_format = get_commit_format(arg+8);
986                                 continue;
987                         }
988                         if (!strcmp(arg, "--root")) {
989                                 revs->show_root_diff = 1;
990                                 continue;
991                         }
992                         if (!strcmp(arg, "--no-commit-id")) {
993                                 revs->no_commit_id = 1;
994                                 continue;
995                         }
996                         if (!strcmp(arg, "--always")) {
997                                 revs->always_show_header = 1;
998                                 continue;
999                         }
1000                         if (!strcmp(arg, "--no-abbrev")) {
1001                                 revs->abbrev = 0;
1002                                 continue;
1003                         }
1004                         if (!strcmp(arg, "--abbrev")) {
1005                                 revs->abbrev = DEFAULT_ABBREV;
1006                                 continue;
1007                         }
1008                         if (!prefixcmp(arg, "--abbrev=")) {
1009                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1010                                 if (revs->abbrev < MINIMUM_ABBREV)
1011                                         revs->abbrev = MINIMUM_ABBREV;
1012                                 else if (revs->abbrev > 40)
1013                                         revs->abbrev = 40;
1014                                 continue;
1015                         }
1016                         if (!strcmp(arg, "--abbrev-commit")) {
1017                                 revs->abbrev_commit = 1;
1018                                 continue;
1019                         }
1020                         if (!strcmp(arg, "--full-diff")) {
1021                                 revs->diff = 1;
1022                                 revs->full_diff = 1;
1023                                 continue;
1024                         }
1025                         if (!strcmp(arg, "--full-history")) {
1026                                 revs->simplify_history = 0;
1027                                 continue;
1028                         }
1029                         if (!strcmp(arg, "--relative-date")) {
1030                                 revs->relative_date = 1;
1031                                 continue;
1032                         }
1033
1034                         /*
1035                          * Grepping the commit log
1036                          */
1037                         if (!prefixcmp(arg, "--author=")) {
1038                                 add_header_grep(revs, "author", arg+9);
1039                                 continue;
1040                         }
1041                         if (!prefixcmp(arg, "--committer=")) {
1042                                 add_header_grep(revs, "committer", arg+12);
1043                                 continue;
1044                         }
1045                         if (!prefixcmp(arg, "--grep=")) {
1046                                 add_message_grep(revs, arg+7);
1047                                 continue;
1048                         }
1049                         if (!strcmp(arg, "--all-match")) {
1050                                 all_match = 1;
1051                                 continue;
1052                         }
1053                         if (!prefixcmp(arg, "--encoding=")) {
1054                                 arg += 11;
1055                                 if (strcmp(arg, "none"))
1056                                         git_log_output_encoding = strdup(arg);
1057                                 else
1058                                         git_log_output_encoding = "";
1059                                 continue;
1060                         }
1061                         if (!strcmp(arg, "--reverse")) {
1062                                 revs->reverse ^= 1;
1063                                 continue;
1064                         }
1065
1066                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1067                         if (opts > 0) {
1068                                 revs->diff = 1;
1069                                 i += opts - 1;
1070                                 continue;
1071                         }
1072                         *unrecognized++ = arg;
1073                         left++;
1074                         continue;
1075                 }
1076
1077                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1078                         int j;
1079                         if (seen_dashdash || *arg == '^')
1080                                 die("bad revision '%s'", arg);
1081
1082                         /* If we didn't have a "--":
1083                          * (1) all filenames must exist;
1084                          * (2) all rev-args must not be interpretable
1085                          *     as a valid filename.
1086                          * but the latter we have checked in the main loop.
1087                          */
1088                         for (j = i; j < argc; j++)
1089                                 verify_filename(revs->prefix, argv[j]);
1090
1091                         revs->prune_data = get_pathspec(revs->prefix,
1092                                                         argv + i);
1093                         break;
1094                 }
1095         }
1096
1097         if (show_merge)
1098                 prepare_show_merge(revs);
1099         if (def && !revs->pending.nr) {
1100                 unsigned char sha1[20];
1101                 struct object *object;
1102                 if (get_sha1(def, sha1))
1103                         die("bad default revision '%s'", def);
1104                 object = get_reference(revs, def, sha1, 0);
1105                 add_pending_object(revs, object, def);
1106         }
1107
1108         if (revs->topo_order)
1109                 revs->limited = 1;
1110
1111         if (revs->prune_data) {
1112                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1113                 revs->prune_fn = try_to_simplify_commit;
1114                 if (!revs->full_diff)
1115                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1116         }
1117         if (revs->combine_merges) {
1118                 revs->ignore_merges = 0;
1119                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1120                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1121         }
1122         revs->diffopt.abbrev = revs->abbrev;
1123         if (diff_setup_done(&revs->diffopt) < 0)
1124                 die("diff_setup_done failed");
1125
1126         if (revs->grep_filter) {
1127                 revs->grep_filter->all_match = all_match;
1128                 compile_grep_patterns(revs->grep_filter);
1129         }
1130
1131         return left;
1132 }
1133
1134 void prepare_revision_walk(struct rev_info *revs)
1135 {
1136         int nr = revs->pending.nr;
1137         struct object_array_entry *e, *list;
1138
1139         e = list = revs->pending.objects;
1140         revs->pending.nr = 0;
1141         revs->pending.alloc = 0;
1142         revs->pending.objects = NULL;
1143         while (--nr >= 0) {
1144                 struct commit *commit = handle_commit(revs, e->item, e->name);
1145                 if (commit) {
1146                         if (!(commit->object.flags & SEEN)) {
1147                                 commit->object.flags |= SEEN;
1148                                 insert_by_date(commit, &revs->commits);
1149                         }
1150                 }
1151                 e++;
1152         }
1153         free(list);
1154
1155         if (revs->no_walk)
1156                 return;
1157         if (revs->limited)
1158                 limit_list(revs);
1159         if (revs->topo_order)
1160                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1161                                              revs->topo_setter,
1162                                              revs->topo_getter);
1163 }
1164
1165 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1166 {
1167         for (;;) {
1168                 struct commit *p = *pp;
1169                 if (!revs->limited)
1170                         add_parents_to_list(revs, p, &revs->commits);
1171                 if (p->parents && p->parents->next)
1172                         return 0;
1173                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1174                         return 0;
1175                 if (!p->parents)
1176                         return -1;
1177                 *pp = p->parents->item;
1178         }
1179 }
1180
1181 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1182 {
1183         struct commit_list **pp = &commit->parents;
1184         while (*pp) {
1185                 struct commit_list *parent = *pp;
1186                 if (rewrite_one(revs, &parent->item) < 0) {
1187                         *pp = parent->next;
1188                         continue;
1189                 }
1190                 pp = &parent->next;
1191         }
1192 }
1193
1194 static void mark_boundary_to_show(struct commit *commit)
1195 {
1196         struct commit_list *p = commit->parents;
1197         while (p) {
1198                 commit = p->item;
1199                 p = p->next;
1200                 if (commit->object.flags & BOUNDARY)
1201                         commit->object.flags |= BOUNDARY_SHOW;
1202         }
1203 }
1204
1205 static int commit_match(struct commit *commit, struct rev_info *opt)
1206 {
1207         if (!opt->grep_filter)
1208                 return 1;
1209         return grep_buffer(opt->grep_filter,
1210                            NULL, /* we say nothing, not even filename */
1211                            commit->buffer, strlen(commit->buffer));
1212 }
1213
1214 static struct commit *get_revision_1(struct rev_info *revs)
1215 {
1216         if (!revs->commits)
1217                 return NULL;
1218
1219         do {
1220                 struct commit_list *entry = revs->commits;
1221                 struct commit *commit = entry->item;
1222
1223                 revs->commits = entry->next;
1224                 free(entry);
1225
1226                 if (revs->reflog_info)
1227                         fake_reflog_parent(revs->reflog_info, commit);
1228
1229                 /*
1230                  * If we haven't done the list limiting, we need to look at
1231                  * the parents here. We also need to do the date-based limiting
1232                  * that we'd otherwise have done in limit_list().
1233                  */
1234                 if (!revs->limited) {
1235                         if (revs->max_age != -1 &&
1236                             (commit->date < revs->max_age)) {
1237                                 if (revs->boundary)
1238                                         commit->object.flags |=
1239                                                 BOUNDARY_SHOW | BOUNDARY;
1240                                 else
1241                                         continue;
1242                         } else
1243                                 add_parents_to_list(revs, commit,
1244                                                 &revs->commits);
1245                 }
1246                 if (commit->object.flags & SHOWN)
1247                         continue;
1248
1249                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1250                                                     revs->ignore_packed))
1251                     continue;
1252
1253                 /* We want to show boundary commits only when their
1254                  * children are shown.  When path-limiter is in effect,
1255                  * rewrite_parents() drops some commits from getting shown,
1256                  * and there is no point showing boundary parents that
1257                  * are not shown.  After rewrite_parents() rewrites the
1258                  * parents of a commit that is shown, we mark the boundary
1259                  * parents with BOUNDARY_SHOW.
1260                  */
1261                 if (commit->object.flags & BOUNDARY_SHOW) {
1262                         commit->object.flags |= SHOWN;
1263                         return commit;
1264                 }
1265                 if (commit->object.flags & UNINTERESTING)
1266                         continue;
1267                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1268                         continue;
1269                 if (revs->no_merges &&
1270                     commit->parents && commit->parents->next)
1271                         continue;
1272                 if (!commit_match(commit, revs))
1273                         continue;
1274                 if (revs->prune_fn && revs->dense) {
1275                         /* Commit without changes? */
1276                         if (!(commit->object.flags & TREECHANGE)) {
1277                                 /* drop merges unless we want parenthood */
1278                                 if (!revs->parents)
1279                                         continue;
1280                                 /* non-merge - always ignore it */
1281                                 if (!commit->parents || !commit->parents->next)
1282                                         continue;
1283                         }
1284                         if (revs->parents)
1285                                 rewrite_parents(revs, commit);
1286                 }
1287                 if (revs->boundary)
1288                         mark_boundary_to_show(commit);
1289                 commit->object.flags |= SHOWN;
1290                 return commit;
1291         } while (revs->commits);
1292         return NULL;
1293 }
1294
1295 struct commit *get_revision(struct rev_info *revs)
1296 {
1297         struct commit *c = NULL;
1298
1299         if (revs->reverse) {
1300                 struct commit_list *list;
1301
1302                 /*
1303                  * rev_info.reverse is used to note the fact that we
1304                  * want to output the list of revisions in reverse
1305                  * order.  To accomplish this goal, reverse can have
1306                  * different values:
1307                  *
1308                  *  0  do nothing
1309                  *  1  reverse the list
1310                  *  2  internal use:  we have already obtained and
1311                  *     reversed the list, now we only need to yield
1312                  *     its items.
1313                  */
1314
1315                 if (revs->reverse == 1) {
1316                         revs->reverse = 0;
1317                         list = NULL;
1318                         while ((c = get_revision(revs)))
1319                                 commit_list_insert(c, &list);
1320                         revs->commits = list;
1321                         revs->reverse = 2;
1322                 }
1323
1324                 if (!revs->commits)
1325                         return NULL;
1326                 c = revs->commits->item;
1327                 list = revs->commits->next;
1328                 free(revs->commits);
1329                 revs->commits = list;
1330                 return c;
1331         }
1332
1333         if (0 < revs->skip_count) {
1334                 while ((c = get_revision_1(revs)) != NULL) {
1335                         if (revs->skip_count-- <= 0)
1336                                 break;
1337                 }
1338         }
1339
1340         /* Check the max_count ... */
1341         switch (revs->max_count) {
1342         case -1:
1343                 break;
1344         case 0:
1345                 if (revs->boundary) {
1346                         struct commit_list *list = revs->commits;
1347                         while (list) {
1348                                 list->item->object.flags |=
1349                                         BOUNDARY_SHOW | BOUNDARY;
1350                                 list = list->next;
1351                         }
1352                         /* all remaining commits are boundary commits */
1353                         revs->max_count = -1;
1354                         revs->limited = 1;
1355                 } else
1356                         return NULL;
1357         default:
1358                 revs->max_count--;
1359         }
1360         if (c)
1361                 return c;
1362         return get_revision_1(revs);
1363 }