Code

Merge git://git.kernel.org/pub/scm/gitk/gitk
[git.git] / rev-list.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "tag.h"
4 #include "commit.h"
5 #include "tree.h"
6 #include "blob.h"
7 #include "epoch.h"
8 #include "diff.h"
10 #define SEEN            (1u << 0)
11 #define INTERESTING     (1u << 1)
12 #define COUNTED         (1u << 2)
13 #define SHOWN           (1u << 3)
14 #define TREECHANGE      (1u << 4)
15 #define TMP_MARK        (1u << 5) /* for isolated cases; clean after use */
17 static const char rev_list_usage[] =
18 "git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
19 "  limiting output:\n"
20 "    --max-count=nr\n"
21 "    --max-age=epoch\n"
22 "    --min-age=epoch\n"
23 "    --sparse\n"
24 "    --no-merges\n"
25 "    --remove-empty\n"
26 "    --all\n"
27 "  ordering output:\n"
28 "    --merge-order [ --show-breaks ]\n"
29 "    --topo-order\n"
30 "  formatting output:\n"
31 "    --parents\n"
32 "    --objects\n"
33 "    --unpacked\n"
34 "    --header | --pretty\n"
35 "  special purpose:\n"
36 "    --bisect"
37 ;
39 static int dense = 1;
40 static int unpacked = 0;
41 static int bisect_list = 0;
42 static int tag_objects = 0;
43 static int tree_objects = 0;
44 static int blob_objects = 0;
45 static int verbose_header = 0;
46 static int show_parents = 0;
47 static int hdr_termination = 0;
48 static const char *commit_prefix = "";
49 static unsigned long max_age = -1;
50 static unsigned long min_age = -1;
51 static int max_count = -1;
52 static enum cmit_fmt commit_format = CMIT_FMT_RAW;
53 static int merge_order = 0;
54 static int show_breaks = 0;
55 static int stop_traversal = 0;
56 static int topo_order = 0;
57 static int no_merges = 0;
58 static const char **paths = NULL;
59 static int remove_empty_trees = 0;
61 static void show_commit(struct commit *commit)
62 {
63         commit->object.flags |= SHOWN;
64         if (show_breaks) {
65                 commit_prefix = "| ";
66                 if (commit->object.flags & DISCONTINUITY) {
67                         commit_prefix = "^ ";     
68                 } else if (commit->object.flags & BOUNDARY) {
69                         commit_prefix = "= ";
70                 } 
71         }                       
72         printf("%s%s", commit_prefix, sha1_to_hex(commit->object.sha1));
73         if (show_parents) {
74                 struct commit_list *parents = commit->parents;
75                 while (parents) {
76                         struct object *o = &(parents->item->object);
77                         parents = parents->next;
78                         if (o->flags & TMP_MARK)
79                                 continue;
80                         printf(" %s", sha1_to_hex(o->sha1));
81                         o->flags |= TMP_MARK;
82                 }
83                 /* TMP_MARK is a general purpose flag that can
84                  * be used locally, but the user should clean
85                  * things up after it is done with them.
86                  */
87                 for (parents = commit->parents;
88                      parents;
89                      parents = parents->next)
90                         parents->item->object.flags &= ~TMP_MARK;
91         }
92         if (commit_format == CMIT_FMT_ONELINE)
93                 putchar(' ');
94         else
95                 putchar('\n');
97         if (verbose_header) {
98                 static char pretty_header[16384];
99                 pretty_print_commit(commit_format, commit, ~0, pretty_header, sizeof(pretty_header), 0);
100                 printf("%s%c", pretty_header, hdr_termination);
101         }
102         fflush(stdout);
105 static int rewrite_one(struct commit **pp)
107         for (;;) {
108                 struct commit *p = *pp;
109                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
110                         return 0;
111                 if (!p->parents)
112                         return -1;
113                 *pp = p->parents->item;
114         }
117 static void rewrite_parents(struct commit *commit)
119         struct commit_list **pp = &commit->parents;
120         while (*pp) {
121                 struct commit_list *parent = *pp;
122                 if (rewrite_one(&parent->item) < 0) {
123                         *pp = parent->next;
124                         continue;
125                 }
126                 pp = &parent->next;
127         }
130 static int filter_commit(struct commit * commit)
132         if (stop_traversal && (commit->object.flags & BOUNDARY))
133                 return STOP;
134         if (commit->object.flags & (UNINTERESTING|SHOWN))
135                 return CONTINUE;
136         if (min_age != -1 && (commit->date > min_age))
137                 return CONTINUE;
138         if (max_age != -1 && (commit->date < max_age)) {
139                 stop_traversal=1;
140                 return CONTINUE;
141         }
142         if (no_merges && (commit->parents && commit->parents->next))
143                 return CONTINUE;
144         if (paths && dense) {
145                 if (!(commit->object.flags & TREECHANGE))
146                         return CONTINUE;
147                 rewrite_parents(commit);
148         }
149         return DO;
152 static int process_commit(struct commit * commit)
154         int action=filter_commit(commit);
156         if (action == STOP) {
157                 return STOP;
158         }
160         if (action == CONTINUE) {
161                 return CONTINUE;
162         }
164         if (max_count != -1 && !max_count--)
165                 return STOP;
167         show_commit(commit);
169         return CONTINUE;
172 static struct object_list **add_object(struct object *obj, struct object_list **p, const char *name)
174         struct object_list *entry = xmalloc(sizeof(*entry));
175         entry->item = obj;
176         entry->next = *p;
177         entry->name = name;
178         *p = entry;
179         return &entry->next;
182 static struct object_list **process_blob(struct blob *blob, struct object_list **p, const char *name)
184         struct object *obj = &blob->object;
186         if (!blob_objects)
187                 return p;
188         if (obj->flags & (UNINTERESTING | SEEN))
189                 return p;
190         obj->flags |= SEEN;
191         return add_object(obj, p, name);
194 static struct object_list **process_tree(struct tree *tree, struct object_list **p, const char *name)
196         struct object *obj = &tree->object;
197         struct tree_entry_list *entry;
199         if (!tree_objects)
200                 return p;
201         if (obj->flags & (UNINTERESTING | SEEN))
202                 return p;
203         if (parse_tree(tree) < 0)
204                 die("bad tree object %s", sha1_to_hex(obj->sha1));
205         obj->flags |= SEEN;
206         p = add_object(obj, p, name);
207         entry = tree->entries;
208         tree->entries = NULL;
209         while (entry) {
210                 struct tree_entry_list *next = entry->next;
211                 if (entry->directory)
212                         p = process_tree(entry->item.tree, p, entry->name);
213                 else
214                         p = process_blob(entry->item.blob, p, entry->name);
215                 free(entry);
216                 entry = next;
217         }
218         return p;
221 static struct object_list *pending_objects = NULL;
223 static void show_commit_list(struct commit_list *list)
225         struct object_list *objects = NULL, **p = &objects, *pending;
226         while (list) {
227                 struct commit *commit = pop_most_recent_commit(&list, SEEN);
229                 p = process_tree(commit->tree, p, "");
230                 if (process_commit(commit) == STOP)
231                         break;
232         }
233         for (pending = pending_objects; pending; pending = pending->next) {
234                 struct object *obj = pending->item;
235                 const char *name = pending->name;
236                 if (obj->flags & (UNINTERESTING | SEEN))
237                         continue;
238                 if (obj->type == tag_type) {
239                         obj->flags |= SEEN;
240                         p = add_object(obj, p, name);
241                         continue;
242                 }
243                 if (obj->type == tree_type) {
244                         p = process_tree((struct tree *)obj, p, name);
245                         continue;
246                 }
247                 if (obj->type == blob_type) {
248                         p = process_blob((struct blob *)obj, p, name);
249                         continue;
250                 }
251                 die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
252         }
253         while (objects) {
254                 /* An object with name "foo\n0000000000000000000000000000000000000000"
255                  * can be used confuse downstream git-pack-objects very badly.
256                  */
257                 const char *ep = strchr(objects->name, '\n');
258                 if (ep) {
259                         printf("%s %.*s\n", sha1_to_hex(objects->item->sha1),
260                                (int) (ep - objects->name),
261                                objects->name);
262                 }
263                 else
264                         printf("%s %s\n", sha1_to_hex(objects->item->sha1), objects->name);
265                 objects = objects->next;
266         }
269 static void mark_blob_uninteresting(struct blob *blob)
271         if (!blob_objects)
272                 return;
273         if (blob->object.flags & UNINTERESTING)
274                 return;
275         blob->object.flags |= UNINTERESTING;
278 static void mark_tree_uninteresting(struct tree *tree)
280         struct object *obj = &tree->object;
281         struct tree_entry_list *entry;
283         if (!tree_objects)
284                 return;
285         if (obj->flags & UNINTERESTING)
286                 return;
287         obj->flags |= UNINTERESTING;
288         if (!has_sha1_file(obj->sha1))
289                 return;
290         if (parse_tree(tree) < 0)
291                 die("bad tree %s", sha1_to_hex(obj->sha1));
292         entry = tree->entries;
293         tree->entries = NULL;
294         while (entry) {
295                 struct tree_entry_list *next = entry->next;
296                 if (entry->directory)
297                         mark_tree_uninteresting(entry->item.tree);
298                 else
299                         mark_blob_uninteresting(entry->item.blob);
300                 free(entry);
301                 entry = next;
302         }
305 static void mark_parents_uninteresting(struct commit *commit)
307         struct commit_list *parents = commit->parents;
309         while (parents) {
310                 struct commit *commit = parents->item;
311                 commit->object.flags |= UNINTERESTING;
313                 /*
314                  * Normally we haven't parsed the parent
315                  * yet, so we won't have a parent of a parent
316                  * here. However, it may turn out that we've
317                  * reached this commit some other way (where it
318                  * wasn't uninteresting), in which case we need
319                  * to mark its parents recursively too..
320                  */
321                 if (commit->parents)
322                         mark_parents_uninteresting(commit);
324                 /*
325                  * A missing commit is ok iff its parent is marked 
326                  * uninteresting.
327                  *
328                  * We just mark such a thing parsed, so that when
329                  * it is popped next time around, we won't be trying
330                  * to parse it and get an error.
331                  */
332                 if (!has_sha1_file(commit->object.sha1))
333                         commit->object.parsed = 1;
334                 parents = parents->next;
335         }
338 static int everybody_uninteresting(struct commit_list *orig)
340         struct commit_list *list = orig;
341         while (list) {
342                 struct commit *commit = list->item;
343                 list = list->next;
344                 if (commit->object.flags & UNINTERESTING)
345                         continue;
346                 return 0;
347         }
348         return 1;
351 /*
352  * This is a truly stupid algorithm, but it's only
353  * used for bisection, and we just don't care enough.
354  *
355  * We care just barely enough to avoid recursing for
356  * non-merge entries.
357  */
358 static int count_distance(struct commit_list *entry)
360         int nr = 0;
362         while (entry) {
363                 struct commit *commit = entry->item;
364                 struct commit_list *p;
366                 if (commit->object.flags & (UNINTERESTING | COUNTED))
367                         break;
368                 if (!paths || (commit->object.flags & TREECHANGE))
369                         nr++;
370                 commit->object.flags |= COUNTED;
371                 p = commit->parents;
372                 entry = p;
373                 if (p) {
374                         p = p->next;
375                         while (p) {
376                                 nr += count_distance(p);
377                                 p = p->next;
378                         }
379                 }
380         }
382         return nr;
385 static void clear_distance(struct commit_list *list)
387         while (list) {
388                 struct commit *commit = list->item;
389                 commit->object.flags &= ~COUNTED;
390                 list = list->next;
391         }
394 static struct commit_list *find_bisection(struct commit_list *list)
396         int nr, closest;
397         struct commit_list *p, *best;
399         nr = 0;
400         p = list;
401         while (p) {
402                 if (!paths || (p->item->object.flags & TREECHANGE))
403                         nr++;
404                 p = p->next;
405         }
406         closest = 0;
407         best = list;
409         for (p = list; p; p = p->next) {
410                 int distance;
412                 if (paths && !(p->item->object.flags & TREECHANGE))
413                         continue;
415                 distance = count_distance(p);
416                 clear_distance(list);
417                 if (nr - distance < distance)
418                         distance = nr - distance;
419                 if (distance > closest) {
420                         best = p;
421                         closest = distance;
422                 }
423         }
424         if (best)
425                 best->next = NULL;
426         return best;
429 static void mark_edges_uninteresting(struct commit_list *list)
431         for ( ; list; list = list->next) {
432                 struct commit_list *parents = list->item->parents;
434                 for ( ; parents; parents = parents->next) {
435                         struct commit *commit = parents->item;
436                         if (commit->object.flags & UNINTERESTING)
437                                 mark_tree_uninteresting(commit->tree);
438                 }
439         }
442 #define TREE_SAME       0
443 #define TREE_NEW        1
444 #define TREE_DIFFERENT  2
445 static int tree_difference = TREE_SAME;
447 static void file_add_remove(struct diff_options *options,
448                     int addremove, unsigned mode,
449                     const unsigned char *sha1,
450                     const char *base, const char *path)
452         int diff = TREE_DIFFERENT;
454         /*
455          * Is it an add of a new file? It means that
456          * the old tree didn't have it at all, so we
457          * will turn "TREE_SAME" -> "TREE_NEW", but
458          * leave any "TREE_DIFFERENT" alone (and if
459          * it already was "TREE_NEW", we'll keep it
460          * "TREE_NEW" of course).
461          */
462         if (addremove == '+') {
463                 diff = tree_difference;
464                 if (diff != TREE_SAME)
465                         return;
466                 diff = TREE_NEW;
467         }
468         tree_difference = diff;
471 static void file_change(struct diff_options *options,
472                  unsigned old_mode, unsigned new_mode,
473                  const unsigned char *old_sha1,
474                  const unsigned char *new_sha1,
475                  const char *base, const char *path)
477         tree_difference = TREE_DIFFERENT;
480 static struct diff_options diff_opt = {
481         .recursive = 1,
482         .add_remove = file_add_remove,
483         .change = file_change,
484 };
486 static int compare_tree(struct tree *t1, struct tree *t2)
488         if (!t1)
489                 return TREE_NEW;
490         if (!t2)
491                 return TREE_DIFFERENT;
492         tree_difference = TREE_SAME;
493         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
494                 return TREE_DIFFERENT;
495         return tree_difference;
498 static int same_tree_as_empty(struct tree *t1)
500         int retval;
501         void *tree;
502         struct tree_desc empty, real;
504         if (!t1)
505                 return 0;
507         tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
508         if (!tree)
509                 return 0;
510         real.buf = tree;
512         empty.buf = "";
513         empty.size = 0;
515         tree_difference = 0;
516         retval = diff_tree(&empty, &real, "", &diff_opt);
517         free(tree);
519         return retval >= 0 && !tree_difference;
522 static void try_to_simplify_commit(struct commit *commit)
524         struct commit_list **pp, *parent;
526         if (!commit->tree)
527                 return;
529         if (!commit->parents) {
530                 if (!same_tree_as_empty(commit->tree))
531                         commit->object.flags |= TREECHANGE;
532                 return;
533         }
535         pp = &commit->parents;
536         while ((parent = *pp) != NULL) {
537                 struct commit *p = parent->item;
539                 if (p->object.flags & UNINTERESTING) {
540                         pp = &parent->next;
541                         continue;
542                 }
544                 parse_commit(p);
545                 switch (compare_tree(p->tree, commit->tree)) {
546                 case TREE_SAME:
547                         parent->next = NULL;
548                         commit->parents = parent;
549                         return;
551                 case TREE_NEW:
552                         if (remove_empty_trees && same_tree_as_empty(p->tree)) {
553                                 *pp = parent->next;
554                                 continue;
555                         }
556                 /* fallthrough */
557                 case TREE_DIFFERENT:
558                         pp = &parent->next;
559                         continue;
560                 }
561                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
562         }
563         commit->object.flags |= TREECHANGE;
566 static void add_parents_to_list(struct commit *commit, struct commit_list **list)
568         struct commit_list *parent = commit->parents;
570         /*
571          * If the commit is uninteresting, don't try to
572          * prune parents - we want the maximal uninteresting
573          * set.
574          *
575          * Normally we haven't parsed the parent
576          * yet, so we won't have a parent of a parent
577          * here. However, it may turn out that we've
578          * reached this commit some other way (where it
579          * wasn't uninteresting), in which case we need
580          * to mark its parents recursively too..
581          */
582         if (commit->object.flags & UNINTERESTING) {
583                 while (parent) {
584                         struct commit *p = parent->item;
585                         parent = parent->next;
586                         parse_commit(p);
587                         p->object.flags |= UNINTERESTING;
588                         if (p->parents)
589                                 mark_parents_uninteresting(p);
590                         if (p->object.flags & SEEN)
591                                 continue;
592                         p->object.flags |= SEEN;
593                         insert_by_date(p, list);
594                 }
595                 return;
596         }
598         /*
599          * Ok, the commit wasn't uninteresting. Try to
600          * simplify the commit history and find the parent
601          * that has no differences in the path set if one exists.
602          */
603         if (paths)
604                 try_to_simplify_commit(commit);
606         parent = commit->parents;
607         while (parent) {
608                 struct commit *p = parent->item;
610                 parent = parent->next;
612                 parse_commit(p);
613                 if (p->object.flags & SEEN)
614                         continue;
615                 p->object.flags |= SEEN;
616                 insert_by_date(p, list);
617         }
620 static struct commit_list *limit_list(struct commit_list *list)
622         struct commit_list *newlist = NULL;
623         struct commit_list **p = &newlist;
624         while (list) {
625                 struct commit_list *entry = list;
626                 struct commit *commit = list->item;
627                 struct object *obj = &commit->object;
629                 list = list->next;
630                 free(entry);
632                 if (max_age != -1 && (commit->date < max_age))
633                         obj->flags |= UNINTERESTING;
634                 if (unpacked && has_sha1_pack(obj->sha1))
635                         obj->flags |= UNINTERESTING;
636                 add_parents_to_list(commit, &list);
637                 if (obj->flags & UNINTERESTING) {
638                         mark_parents_uninteresting(commit);
639                         if (everybody_uninteresting(list))
640                                 break;
641                         continue;
642                 }
643                 if (min_age != -1 && (commit->date > min_age))
644                         continue;
645                 p = &commit_list_insert(commit, p)->next;
646         }
647         if (tree_objects)
648                 mark_edges_uninteresting(newlist);
649         if (bisect_list)
650                 newlist = find_bisection(newlist);
651         return newlist;
654 static void add_pending_object(struct object *obj, const char *name)
656         add_object(obj, &pending_objects, name);
659 static struct commit *get_commit_reference(const char *name, const unsigned char *sha1, unsigned int flags)
661         struct object *object;
663         object = parse_object(sha1);
664         if (!object)
665                 die("bad object %s", name);
667         /*
668          * Tag object? Look what it points to..
669          */
670         while (object->type == tag_type) {
671                 struct tag *tag = (struct tag *) object;
672                 object->flags |= flags;
673                 if (tag_objects && !(object->flags & UNINTERESTING))
674                         add_pending_object(object, tag->tag);
675                 object = parse_object(tag->tagged->sha1);
676                 if (!object)
677                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
678         }
680         /*
681          * Commit object? Just return it, we'll do all the complex
682          * reachability crud.
683          */
684         if (object->type == commit_type) {
685                 struct commit *commit = (struct commit *)object;
686                 object->flags |= flags;
687                 if (parse_commit(commit) < 0)
688                         die("unable to parse commit %s", name);
689                 if (flags & UNINTERESTING)
690                         mark_parents_uninteresting(commit);
691                 return commit;
692         }
694         /*
695          * Tree object? Either mark it uniniteresting, or add it
696          * to the list of objects to look at later..
697          */
698         if (object->type == tree_type) {
699                 struct tree *tree = (struct tree *)object;
700                 if (!tree_objects)
701                         return NULL;
702                 if (flags & UNINTERESTING) {
703                         mark_tree_uninteresting(tree);
704                         return NULL;
705                 }
706                 add_pending_object(object, "");
707                 return NULL;
708         }
710         /*
711          * Blob object? You know the drill by now..
712          */
713         if (object->type == blob_type) {
714                 struct blob *blob = (struct blob *)object;
715                 if (!blob_objects)
716                         return NULL;
717                 if (flags & UNINTERESTING) {
718                         mark_blob_uninteresting(blob);
719                         return NULL;
720                 }
721                 add_pending_object(object, "");
722                 return NULL;
723         }
724         die("%s is unknown object", name);
727 static void handle_one_commit(struct commit *com, struct commit_list **lst)
729         if (!com || com->object.flags & SEEN)
730                 return;
731         com->object.flags |= SEEN;
732         commit_list_insert(com, lst);
735 /* for_each_ref() callback does not allow user data -- Yuck. */
736 static struct commit_list **global_lst;
738 static int include_one_commit(const char *path, const unsigned char *sha1)
740         struct commit *com = get_commit_reference(path, sha1, 0);
741         handle_one_commit(com, global_lst);
742         return 0;
745 static void handle_all(struct commit_list **lst)
747         global_lst = lst;
748         for_each_ref(include_one_commit);
749         global_lst = NULL;
752 int main(int argc, const char **argv)
754         const char *prefix = setup_git_directory();
755         struct commit_list *list = NULL;
756         int i, limited = 0;
758         for (i = 1 ; i < argc; i++) {
759                 int flags;
760                 const char *arg = argv[i];
761                 char *dotdot;
762                 struct commit *commit;
763                 unsigned char sha1[20];
765                 /* accept -<digit>, like traditilnal "head" */
766                 if ((*arg == '-') && isdigit(arg[1])) {
767                         max_count = atoi(arg + 1);
768                         continue;
769                 }
770                 if (!strcmp(arg, "-n")) {
771                         if (++i >= argc)
772                                 die("-n requires an argument");
773                         max_count = atoi(argv[i]);
774                         continue;
775                 }
776                 if (!strncmp(arg,"-n",2)) {
777                         max_count = atoi(arg + 2);
778                         continue;
779                 }
780                 if (!strncmp(arg, "--max-count=", 12)) {
781                         max_count = atoi(arg + 12);
782                         continue;
783                 }
784                 if (!strncmp(arg, "--max-age=", 10)) {
785                         max_age = atoi(arg + 10);
786                         limited = 1;
787                         continue;
788                 }
789                 if (!strncmp(arg, "--min-age=", 10)) {
790                         min_age = atoi(arg + 10);
791                         limited = 1;
792                         continue;
793                 }
794                 if (!strcmp(arg, "--header")) {
795                         verbose_header = 1;
796                         continue;
797                 }
798                 if (!strncmp(arg, "--pretty", 8)) {
799                         commit_format = get_commit_format(arg+8);
800                         verbose_header = 1;
801                         hdr_termination = '\n';
802                         if (commit_format == CMIT_FMT_ONELINE)
803                                 commit_prefix = "";
804                         else
805                                 commit_prefix = "commit ";
806                         continue;
807                 }
808                 if (!strncmp(arg, "--no-merges", 11)) {
809                         no_merges = 1;
810                         continue;
811                 }
812                 if (!strcmp(arg, "--parents")) {
813                         show_parents = 1;
814                         continue;
815                 }
816                 if (!strcmp(arg, "--bisect")) {
817                         bisect_list = 1;
818                         continue;
819                 }
820                 if (!strcmp(arg, "--all")) {
821                         handle_all(&list);
822                         continue;
823                 }
824                 if (!strcmp(arg, "--objects")) {
825                         tag_objects = 1;
826                         tree_objects = 1;
827                         blob_objects = 1;
828                         continue;
829                 }
830                 if (!strcmp(arg, "--unpacked")) {
831                         unpacked = 1;
832                         limited = 1;
833                         continue;
834                 }
835                 if (!strcmp(arg, "--merge-order")) {
836                         merge_order = 1;
837                         continue;
838                 }
839                 if (!strcmp(arg, "--show-breaks")) {
840                         show_breaks = 1;
841                         continue;
842                 }
843                 if (!strcmp(arg, "--topo-order")) {
844                         topo_order = 1;
845                         limited = 1;
846                         continue;
847                 }
848                 if (!strcmp(arg, "--dense")) {
849                         dense = 1;
850                         continue;
851                 }
852                 if (!strcmp(arg, "--sparse")) {
853                         dense = 0;
854                         continue;
855                 }
856                 if (!strcmp(arg, "--remove-empty")) {
857                         remove_empty_trees = 1;
858                         continue;
859                 }
860                 if (!strcmp(arg, "--")) {
861                         i++;
862                         break;
863                 }
865                 if (show_breaks && !merge_order)
866                         usage(rev_list_usage);
868                 flags = 0;
869                 dotdot = strstr(arg, "..");
870                 if (dotdot) {
871                         unsigned char from_sha1[20];
872                         char *next = dotdot + 2;
873                         *dotdot = 0;
874                         if (!*next)
875                                 next = "HEAD";
876                         if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
877                                 struct commit *exclude;
878                                 struct commit *include;
879                                 
880                                 exclude = get_commit_reference(arg, from_sha1, UNINTERESTING);
881                                 include = get_commit_reference(next, sha1, 0);
882                                 if (!exclude || !include)
883                                         die("Invalid revision range %s..%s", arg, next);
884                                 limited = 1;
885                                 handle_one_commit(exclude, &list);
886                                 handle_one_commit(include, &list);
887                                 continue;
888                         }
889                         *dotdot = '.';
890                 }
891                 if (*arg == '^') {
892                         flags = UNINTERESTING;
893                         arg++;
894                         limited = 1;
895                 }
896                 if (get_sha1(arg, sha1) < 0) {
897                         struct stat st;
898                         if (lstat(arg, &st) < 0)
899                                 die("'%s': %s", arg, strerror(errno));
900                         break;
901                 }
902                 commit = get_commit_reference(arg, sha1, flags);
903                 handle_one_commit(commit, &list);
904         }
906         if (!list &&
907             (!(tag_objects||tree_objects||blob_objects) && !pending_objects))
908                 usage(rev_list_usage);
910         paths = get_pathspec(prefix, argv + i);
911         if (paths) {
912                 limited = 1;
913                 diff_tree_setup_paths(paths);
914         }
916         save_commit_buffer = verbose_header;
917         track_object_refs = 0;
919         if (!merge_order) {             
920                 sort_by_date(&list);
921                 if (list && !limited && max_count == 1 &&
922                     !tag_objects && !tree_objects && !blob_objects) {
923                         show_commit(list->item);
924                         return 0;
925                 }
926                 if (limited)
927                         list = limit_list(list);
928                 if (topo_order)
929                         sort_in_topological_order(&list);
930                 show_commit_list(list);
931         } else {
932 #ifndef NO_OPENSSL
933                 if (sort_list_in_merge_order(list, &process_commit)) {
934                         die("merge order sort failed\n");
935                 }
936 #else
937                 die("merge order sort unsupported, OpenSSL not linked");
938 #endif
939         }
941         return 0;