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
  11 static char *path_name(struct name_path *path, const char *name)
  12 {
  13         struct name_path *p;
  14         char *n, *m;
  15         int nlen = strlen(name);
  16         int len = nlen + 1;
  17
  18         for (p = path; p; p = p->up) {
  19                 if (p->elem_len)
  20                         len += p->elem_len + 1;
  21         }
  22         n = xmalloc(len);
  23         m = n + len - (nlen + 1);
  24         strcpy(m, name);
  25         for (p = path; p; p = p->up) {
  26                 if (p->elem_len) {
  27                         m -= p->elem_len + 1;
  28                         memcpy(m, p->elem, p->elem_len);
  29                         m[p->elem_len] = '/';
  30                 }
  31         }
  32         return n;
  33 }
  34
  35 void add_object(struct object *obj,
  36                 struct object_array *p,
  37                 struct name_path *path,
  38                 const char *name)
  39 {
  40         add_object_array(obj, path_name(path, name), p);
  41 }
  42
  43 static void mark_blob_uninteresting(struct blob *blob)
  44 {
  45         if (blob->object.flags & UNINTERESTING)
  46                 return;
  47         blob->object.flags |= UNINTERESTING;
  48 }
  49
  50 void mark_tree_uninteresting(struct tree *tree)
  51 {
  52         struct tree_desc desc;
  53         struct name_entry entry;
  54         struct object *obj = &tree->object;
  55
  56         if (obj->flags & UNINTERESTING)
  57                 return;
  58         obj->flags |= UNINTERESTING;
  59         if (!has_sha1_file(obj->sha1))
  60                 return;
  61         if (parse_tree(tree) < 0)
  62                 die("bad tree %s", sha1_to_hex(obj->sha1));
  63
  64         desc.buf = tree->buffer;
  65         desc.size = tree->size;
  66         while (tree_entry(&desc, &entry)) {
  67                 if (S_ISDIR(entry.mode))
  68                         mark_tree_uninteresting(lookup_tree(entry.sha1));
  69                 else
  70                         mark_blob_uninteresting(lookup_blob(entry.sha1));
  71         }
  72
  73         /*
  74          * We don't care about the tree any more
  75          * after it has been marked uninteresting.
  76          */
  77         free(tree->buffer);
  78         tree->buffer = NULL;
  79 }
  80
  81 void mark_parents_uninteresting(struct commit *commit)
  82 {
  83         struct commit_list *parents = commit->parents;
  84
  85         while (parents) {
  86                 struct commit *commit = parents->item;
  87                 if (!(commit->object.flags & UNINTERESTING)) {
  88                         commit->object.flags |= UNINTERESTING;
  89
  90                         /*
  91                          * Normally we haven't parsed the parent
  92                          * yet, so we won't have a parent of a parent
  93                          * here. However, it may turn out that we've
  94                          * reached this commit some other way (where it
  95                          * wasn't uninteresting), in which case we need
  96                          * to mark its parents recursively too..
  97                          */
  98                         if (commit->parents)
  99                                 mark_parents_uninteresting(commit);
 100                 }
 101
 102                 /*
 103                  * A missing commit is ok iff its parent is marked
 104                  * uninteresting.
 105                  *
 106                  * We just mark such a thing parsed, so that when
 107                  * it is popped next time around, we won't be trying
 108                  * to parse it and get an error.
 109                  */
 110                 if (!has_sha1_file(commit->object.sha1))
 111                         commit->object.parsed = 1;
 112                 parents = parents->next;
 113         }
 114 }
 115
 116 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 117 {
 118         add_object_array(obj, name, &revs->pending);
 119 }
 120
 121 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 122 {
 123         struct object *object;
 124
 125         object = parse_object(sha1);
 126         if (!object)
 127                 die("bad object %s", name);
 128         object->flags |= flags;
 129         return object;
 130 }
 131
 132 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 133 {
 134         unsigned long flags = object->flags;
 135
 136         /*
 137          * Tag object? Look what it points to..
 138          */
 139         while (object->type == OBJ_TAG) {
 140                 struct tag *tag = (struct tag *) object;
 141                 if (revs->tag_objects && !(flags & UNINTERESTING))
 142                         add_pending_object(revs, object, tag->tag);
 143                 object = parse_object(tag->tagged->sha1);
 144                 if (!object)
 145                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 146         }
 147
 148         /*
 149          * Commit object? Just return it, we'll do all the complex
 150          * reachability crud.
 151          */
 152         if (object->type == OBJ_COMMIT) {
 153                 struct commit *commit = (struct commit *)object;
 154                 if (parse_commit(commit) < 0)
 155                         die("unable to parse commit %s", name);
 156                 if (flags & UNINTERESTING) {
 157                         commit->object.flags |= UNINTERESTING;
 158                         mark_parents_uninteresting(commit);
 159                         revs->limited = 1;
 160                 }
 161                 return commit;
 162         }
 163
 164         /*
 165          * Tree object? Either mark it uniniteresting, or add it
 166          * to the list of objects to look at later..
 167          */
 168         if (object->type == OBJ_TREE) {
 169                 struct tree *tree = (struct tree *)object;
 170                 if (!revs->tree_objects)
 171                         return NULL;
 172                 if (flags & UNINTERESTING) {
 173                         mark_tree_uninteresting(tree);
 174                         return NULL;
 175                 }
 176                 add_pending_object(revs, object, "");
 177                 return NULL;
 178         }
 179
 180         /*
 181          * Blob object? You know the drill by now..
 182          */
 183         if (object->type == OBJ_BLOB) {
 184                 struct blob *blob = (struct blob *)object;
 185                 if (!revs->blob_objects)
 186                         return NULL;
 187                 if (flags & UNINTERESTING) {
 188                         mark_blob_uninteresting(blob);
 189                         return NULL;
 190                 }
 191                 add_pending_object(revs, object, "");
 192                 return NULL;
 193         }
 194         die("%s is unknown object", name);
 195 }
 196
 197 static int everybody_uninteresting(struct commit_list *orig)
 198 {
 199         struct commit_list *list = orig;
 200         while (list) {
 201                 struct commit *commit = list->item;
 202                 list = list->next;
 203                 if (commit->object.flags & UNINTERESTING)
 204                         continue;
 205                 return 0;
 206         }
 207         return 1;
 208 }
 209
 210 static int tree_difference = REV_TREE_SAME;
 211
 212 static void file_add_remove(struct diff_options *options,
 213                     int addremove, unsigned mode,
 214                     const unsigned char *sha1,
 215                     const char *base, const char *path)
 216 {
 217         int diff = REV_TREE_DIFFERENT;
 218
 219         /*
 220          * Is it an add of a new file? It means that the old tree
 221          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 222          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 223          * (and if it already was "REV_TREE_NEW", we'll keep it
 224          * "REV_TREE_NEW" of course).
 225          */
 226         if (addremove == '+') {
 227                 diff = tree_difference;
 228                 if (diff != REV_TREE_SAME)
 229                         return;
 230                 diff = REV_TREE_NEW;
 231         }
 232         tree_difference = diff;
 233 }
 234
 235 static void file_change(struct diff_options *options,
 236                  unsigned old_mode, unsigned new_mode,
 237                  const unsigned char *old_sha1,
 238                  const unsigned char *new_sha1,
 239                  const char *base, const char *path)
 240 {
 241         tree_difference = REV_TREE_DIFFERENT;
 242 }
 243
 244 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 245 {
 246         if (!t1)
 247                 return REV_TREE_NEW;
 248         if (!t2)
 249                 return REV_TREE_DIFFERENT;
 250         tree_difference = REV_TREE_SAME;
 251         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 252                            &revs->pruning) < 0)
 253                 return REV_TREE_DIFFERENT;
 254         return tree_difference;
 255 }
 256
 257 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 258 {
 259         int retval;
 260         void *tree;
 261         struct tree_desc empty, real;
 262
 263         if (!t1)
 264                 return 0;
 265
 266         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
 267         if (!tree)
 268                 return 0;
 269         real.buf = tree;
 270
 271         empty.buf = "";
 272         empty.size = 0;
 273
 274         tree_difference = 0;
 275         retval = diff_tree(&empty, &real, "", &revs->pruning);
 276         free(tree);
 277
 278         return retval >= 0 && !tree_difference;
 279 }
 280
 281 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 282 {
 283         struct commit_list **pp, *parent;
 284         int tree_changed = 0, tree_same = 0;
 285
 286         if (!commit->tree)
 287                 return;
 288
 289         if (!commit->parents) {
 290                 if (!rev_same_tree_as_empty(revs, commit->tree))
 291                         commit->object.flags |= TREECHANGE;
 292                 return;
 293         }
 294
 295         pp = &commit->parents;
 296         while ((parent = *pp) != NULL) {
 297                 struct commit *p = parent->item;
 298
 299                 parse_commit(p);
 300                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 301                 case REV_TREE_SAME:
 302                         tree_same = 1;
 303                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 304                                 /* Even if a merge with an uninteresting
 305                                  * side branch brought the entire change
 306                                  * we are interested in, we do not want
 307                                  * to lose the other branches of this
 308                                  * merge, so we just keep going.
 309                                  */
 310                                 pp = &parent->next;
 311                                 continue;
 312                         }
 313                         parent->next = NULL;
 314                         commit->parents = parent;
 315                         return;
 316
 317                 case REV_TREE_NEW:
 318                         if (revs->remove_empty_trees &&
 319                             rev_same_tree_as_empty(revs, p->tree)) {
 320                                 /* We are adding all the specified
 321                                  * paths from this parent, so the
 322                                  * history beyond this parent is not
 323                                  * interesting.  Remove its parents
 324                                  * (they are grandparents for us).
 325                                  * IOW, we pretend this parent is a
 326                                  * "root" commit.
 327                                  */
 328                                 parse_commit(p);
 329                                 p->parents = NULL;
 330                         }
 331                 /* fallthrough */
 332                 case REV_TREE_DIFFERENT:
 333                         tree_changed = 1;
 334                         pp = &parent->next;
 335                         continue;
 336                 }
 337                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 338         }
 339         if (tree_changed && !tree_same)
 340                 commit->object.flags |= TREECHANGE;
 341 }
 342
 343 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 344 {
 345         struct commit_list *parent = commit->parents;
 346         unsigned left_flag;
 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         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 392         parent = commit->parents;
 393         while (parent) {
 394                 struct commit *p = parent->item;
 395
 396                 parent = parent->next;
 397
 398                 parse_commit(p);
 399                 p->object.flags |= left_flag;
 400                 if (p->object.flags & SEEN)
 401                         continue;
 402                 p->object.flags |= SEEN;
 403                 insert_by_date(p, list);
 404         }
 405 }
 406
 407 static void limit_list(struct rev_info *revs)
 408 {
 409         struct commit_list *list = revs->commits;
 410         struct commit_list *newlist = NULL;
 411         struct commit_list **p = &newlist;
 412
 413         while (list) {
 414                 struct commit_list *entry = list;
 415                 struct commit *commit = list->item;
 416                 struct object *obj = &commit->object;
 417
 418                 list = list->next;
 419                 free(entry);
 420
 421                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 422                         obj->flags |= UNINTERESTING;
 423                 add_parents_to_list(revs, commit, &list);
 424                 if (obj->flags & UNINTERESTING) {
 425                         mark_parents_uninteresting(commit);
 426                         if (everybody_uninteresting(list))
 427                                 break;
 428                         continue;
 429                 }
 430                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 431                         continue;
 432                 p = &commit_list_insert(commit, p)->next;
 433         }
 434         if (revs->boundary) {
 435                 /* mark the ones that are on the result list first */
 436                 for (list = newlist; list; list = list->next) {
 437                         struct commit *commit = list->item;
 438                         commit->object.flags |= TMP_MARK;
 439                 }
 440                 for (list = newlist; list; list = list->next) {
 441                         struct commit *commit = list->item;
 442                         struct object *obj = &commit->object;
 443                         struct commit_list *parent;
 444                         if (obj->flags & UNINTERESTING)
 445                                 continue;
 446                         for (parent = commit->parents;
 447                              parent;
 448                              parent = parent->next) {
 449                                 struct commit *pcommit = parent->item;
 450                                 if (!(pcommit->object.flags & UNINTERESTING))
 451                                         continue;
 452                                 pcommit->object.flags |= BOUNDARY;
 453                                 if (pcommit->object.flags & TMP_MARK)
 454                                         continue;
 455                                 pcommit->object.flags |= TMP_MARK;
 456                                 p = &commit_list_insert(pcommit, p)->next;
 457                         }
 458                 }
 459                 for (list = newlist; list; list = list->next) {
 460                         struct commit *commit = list->item;
 461                         commit->object.flags &= ~TMP_MARK;
 462                 }
 463         }
 464         revs->commits = newlist;
 465 }
 466
 467 struct all_refs_cb {
 468         int all_flags;
 469         int warned_bad_reflog;
 470         struct rev_info *all_revs;
 471         const char *name_for_errormsg;
 472 };
 473
 474 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 475 {
 476         struct all_refs_cb *cb = cb_data;
 477         struct object *object = get_reference(cb->all_revs, path, sha1,
 478                                               cb->all_flags);
 479         add_pending_object(cb->all_revs, object, "");
 480         return 0;
 481 }
 482
 483 static void handle_all(struct rev_info *revs, unsigned flags)
 484 {
 485         struct all_refs_cb cb;
 486         cb.all_revs = revs;
 487         cb.all_flags = flags;
 488         for_each_ref(handle_one_ref, &cb);
 489 }
 490
 491 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 492 {
 493         struct all_refs_cb *cb = cb_data;
 494         if (!is_null_sha1(sha1)) {
 495                 struct object *o = parse_object(sha1);
 496                 if (o) {
 497                         o->flags |= cb->all_flags;
 498                         add_pending_object(cb->all_revs, o, "");
 499                 }
 500                 else if (!cb->warned_bad_reflog) {
 501                         warn("reflog of '%s' references pruned commits",
 502                                 cb->name_for_errormsg);
 503                         cb->warned_bad_reflog = 1;
 504                 }
 505         }
 506 }
 507
 508 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 509                 const char *email, unsigned long timestamp, int tz,
 510                 const char *message, void *cb_data)
 511 {
 512         handle_one_reflog_commit(osha1, cb_data);
 513         handle_one_reflog_commit(nsha1, cb_data);
 514         return 0;
 515 }
 516
 517 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 518 {
 519         struct all_refs_cb *cb = cb_data;
 520         cb->warned_bad_reflog = 0;
 521         cb->name_for_errormsg = path;
 522         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 523         return 0;
 524 }
 525
 526 static void handle_reflog(struct rev_info *revs, unsigned flags)
 527 {
 528         struct all_refs_cb cb;
 529         cb.all_revs = revs;
 530         cb.all_flags = flags;
 531         for_each_ref(handle_one_reflog, &cb);
 532 }
 533
 534 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 535 {
 536         unsigned char sha1[20];
 537         struct object *it;
 538         struct commit *commit;
 539         struct commit_list *parents;
 540
 541         if (*arg == '^') {
 542                 flags ^= UNINTERESTING;
 543                 arg++;
 544         }
 545         if (get_sha1(arg, sha1))
 546                 return 0;
 547         while (1) {
 548                 it = get_reference(revs, arg, sha1, 0);
 549                 if (it->type != OBJ_TAG)
 550                         break;
 551                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 552         }
 553         if (it->type != OBJ_COMMIT)
 554                 return 0;
 555         commit = (struct commit *)it;
 556         for (parents = commit->parents; parents; parents = parents->next) {
 557                 it = &parents->item->object;
 558                 it->flags |= flags;
 559                 add_pending_object(revs, it, arg);
 560         }
 561         return 1;
 562 }
 563
 564 void init_revisions(struct rev_info *revs, const char *prefix)
 565 {
 566         memset(revs, 0, sizeof(*revs));
 567
 568         revs->abbrev = DEFAULT_ABBREV;
 569         revs->ignore_merges = 1;
 570         revs->simplify_history = 1;
 571         revs->pruning.recursive = 1;
 572         revs->pruning.add_remove = file_add_remove;
 573         revs->pruning.change = file_change;
 574         revs->lifo = 1;
 575         revs->dense = 1;
 576         revs->prefix = prefix;
 577         revs->max_age = -1;
 578         revs->min_age = -1;
 579         revs->skip_count = -1;
 580         revs->max_count = -1;
 581
 582         revs->prune_fn = NULL;
 583         revs->prune_data = NULL;
 584
 585         revs->topo_setter = topo_sort_default_setter;
 586         revs->topo_getter = topo_sort_default_getter;
 587
 588         revs->commit_format = CMIT_FMT_DEFAULT;
 589
 590         diff_setup(&revs->diffopt);
 591 }
 592
 593 static void add_pending_commit_list(struct rev_info *revs,
 594                                     struct commit_list *commit_list,
 595                                     unsigned int flags)
 596 {
 597         while (commit_list) {
 598                 struct object *object = &commit_list->item->object;
 599                 object->flags |= flags;
 600                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 601                 commit_list = commit_list->next;
 602         }
 603 }
 604
 605 static void prepare_show_merge(struct rev_info *revs)
 606 {
 607         struct commit_list *bases;
 608         struct commit *head, *other;
 609         unsigned char sha1[20];
 610         const char **prune = NULL;
 611         int i, prune_num = 1; /* counting terminating NULL */
 612
 613         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 614                 die("--merge without HEAD?");
 615         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 616                 die("--merge without MERGE_HEAD?");
 617         add_pending_object(revs, &head->object, "HEAD");
 618         add_pending_object(revs, &other->object, "MERGE_HEAD");
 619         bases = get_merge_bases(head, other, 1);
 620         while (bases) {
 621                 struct commit *it = bases->item;
 622                 struct commit_list *n = bases->next;
 623                 free(bases);
 624                 bases = n;
 625                 it->object.flags |= UNINTERESTING;
 626                 add_pending_object(revs, &it->object, "(merge-base)");
 627         }
 628
 629         if (!active_nr)
 630                 read_cache();
 631         for (i = 0; i < active_nr; i++) {
 632                 struct cache_entry *ce = active_cache[i];
 633                 if (!ce_stage(ce))
 634                         continue;
 635                 if (ce_path_match(ce, revs->prune_data)) {
 636                         prune_num++;
 637                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 638                         prune[prune_num-2] = ce->name;
 639                         prune[prune_num-1] = NULL;
 640                 }
 641                 while ((i+1 < active_nr) &&
 642                        ce_same_name(ce, active_cache[i+1]))
 643                         i++;
 644         }
 645         revs->prune_data = prune;
 646 }
 647
 648 int handle_revision_arg(const char *arg, struct rev_info *revs,
 649                         int flags,
 650                         int cant_be_filename)
 651 {
 652         char *dotdot;
 653         struct object *object;
 654         unsigned char sha1[20];
 655         int local_flags;
 656
 657         dotdot = strstr(arg, "..");
 658         if (dotdot) {
 659                 unsigned char from_sha1[20];
 660                 const char *next = dotdot + 2;
 661                 const char *this = arg;
 662                 int symmetric = *next == '.';
 663                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 664
 665                 *dotdot = 0;
 666                 next += symmetric;
 667
 668                 if (!*next)
 669                         next = "HEAD";
 670                 if (dotdot == arg)
 671                         this = "HEAD";
 672                 if (!get_sha1(this, from_sha1) &&
 673                     !get_sha1(next, sha1)) {
 674                         struct commit *a, *b;
 675                         struct commit_list *exclude;
 676
 677                         a = lookup_commit_reference(from_sha1);
 678                         b = lookup_commit_reference(sha1);
 679                         if (!a || !b) {
 680                                 die(symmetric ?
 681                                     "Invalid symmetric difference expression %s...%s" :
 682                                     "Invalid revision range %s..%s",
 683                                     arg, next);
 684                         }
 685
 686                         if (!cant_be_filename) {
 687                                 *dotdot = '.';
 688                                 verify_non_filename(revs->prefix, arg);
 689                         }
 690
 691                         if (symmetric) {
 692                                 exclude = get_merge_bases(a, b, 1);
 693                                 add_pending_commit_list(revs, exclude,
 694                                                         flags_exclude);
 695                                 free_commit_list(exclude);
 696                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 697                         } else
 698                                 a->object.flags |= flags_exclude;
 699                         b->object.flags |= flags;
 700                         add_pending_object(revs, &a->object, this);
 701                         add_pending_object(revs, &b->object, next);
 702                         return 0;
 703                 }
 704                 *dotdot = '.';
 705         }
 706         dotdot = strstr(arg, "^@");
 707         if (dotdot && !dotdot[2]) {
 708                 *dotdot = 0;
 709                 if (add_parents_only(revs, arg, flags))
 710                         return 0;
 711                 *dotdot = '^';
 712         }
 713         dotdot = strstr(arg, "^!");
 714         if (dotdot && !dotdot[2]) {
 715                 *dotdot = 0;
 716                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 717                         *dotdot = '^';
 718         }
 719
 720         local_flags = 0;
 721         if (*arg == '^') {
 722                 local_flags = UNINTERESTING;
 723                 arg++;
 724         }
 725         if (get_sha1(arg, sha1))
 726                 return -1;
 727         if (!cant_be_filename)
 728                 verify_non_filename(revs->prefix, arg);
 729         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 730         add_pending_object(revs, object, arg);
 731         return 0;
 732 }
 733
 734 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 735 {
 736         if (!revs->grep_filter) {
 737                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 738                 opt->status_only = 1;
 739                 opt->pattern_tail = &(opt->pattern_list);
 740                 opt->regflags = REG_NEWLINE;
 741                 revs->grep_filter = opt;
 742         }
 743         append_grep_pattern(revs->grep_filter, ptn,
 744                             "command line", 0, what);
 745 }
 746
 747 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 748 {
 749         char *pat;
 750         const char *prefix;
 751         int patlen, fldlen;
 752
 753         fldlen = strlen(field);
 754         patlen = strlen(pattern);
 755         pat = xmalloc(patlen + fldlen + 10);
 756         prefix = ".*";
 757         if (*pattern == '^') {
 758                 prefix = "";
 759                 pattern++;
 760         }
 761         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 762         add_grep(revs, pat, GREP_PATTERN_HEAD);
 763 }
 764
 765 static void add_message_grep(struct rev_info *revs, const char *pattern)
 766 {
 767         add_grep(revs, pattern, GREP_PATTERN_BODY);
 768 }
 769
 770 static void add_ignore_packed(struct rev_info *revs, const char *name)
 771 {
 772         int num = ++revs->num_ignore_packed;
 773
 774         revs->ignore_packed = xrealloc(revs->ignore_packed,
 775                                        sizeof(const char **) * (num + 1));
 776         revs->ignore_packed[num-1] = name;
 777         revs->ignore_packed[num] = NULL;
 778 }
 779
 780 /*
 781  * Parse revision information, filling in the "rev_info" structure,
 782  * and removing the used arguments from the argument list.
 783  *
 784  * Returns the number of arguments left that weren't recognized
 785  * (which are also moved to the head of the argument list)
 786  */
 787 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 788 {
 789         int i, flags, seen_dashdash, show_merge;
 790         const char **unrecognized = argv + 1;
 791         int left = 1;
 792         int all_match = 0;
 793
 794         /* First, search for "--" */
 795         seen_dashdash = 0;
 796         for (i = 1; i < argc; i++) {
 797                 const char *arg = argv[i];
 798                 if (strcmp(arg, "--"))
 799                         continue;
 800                 argv[i] = NULL;
 801                 argc = i;
 802                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 803                 seen_dashdash = 1;
 804                 break;
 805         }
 806
 807         flags = show_merge = 0;
 808         for (i = 1; i < argc; i++) {
 809                 const char *arg = argv[i];
 810                 if (*arg == '-') {
 811                         int opts;
 812                         if (!strncmp(arg, "--max-count=", 12)) {
 813                                 revs->max_count = atoi(arg + 12);
 814                                 continue;
 815                         }
 816                         if (!strncmp(arg, "--skip=", 7)) {
 817                                 revs->skip_count = atoi(arg + 7);
 818                                 continue;
 819                         }
 820                         /* accept -<digit>, like traditional "head" */
 821                         if ((*arg == '-') && isdigit(arg[1])) {
 822                                 revs->max_count = atoi(arg + 1);
 823                                 continue;
 824                         }
 825                         if (!strcmp(arg, "-n")) {
 826                                 if (argc <= i + 1)
 827                                         die("-n requires an argument");
 828                                 revs->max_count = atoi(argv[++i]);
 829                                 continue;
 830                         }
 831                         if (!strncmp(arg,"-n",2)) {
 832                                 revs->max_count = atoi(arg + 2);
 833                                 continue;
 834                         }
 835                         if (!strncmp(arg, "--max-age=", 10)) {
 836                                 revs->max_age = atoi(arg + 10);
 837                                 continue;
 838                         }
 839                         if (!strncmp(arg, "--since=", 8)) {
 840                                 revs->max_age = approxidate(arg + 8);
 841                                 continue;
 842                         }
 843                         if (!strncmp(arg, "--after=", 8)) {
 844                                 revs->max_age = approxidate(arg + 8);
 845                                 continue;
 846                         }
 847                         if (!strncmp(arg, "--min-age=", 10)) {
 848                                 revs->min_age = atoi(arg + 10);
 849                                 continue;
 850                         }
 851                         if (!strncmp(arg, "--before=", 9)) {
 852                                 revs->min_age = approxidate(arg + 9);
 853                                 continue;
 854                         }
 855                         if (!strncmp(arg, "--until=", 8)) {
 856                                 revs->min_age = approxidate(arg + 8);
 857                                 continue;
 858                         }
 859                         if (!strcmp(arg, "--all")) {
 860                                 handle_all(revs, flags);
 861                                 continue;
 862                         }
 863                         if (!strcmp(arg, "--reflog")) {
 864                                 handle_reflog(revs, flags);
 865                                 continue;
 866                         }
 867                         if (!strcmp(arg, "--not")) {
 868                                 flags ^= UNINTERESTING;
 869                                 continue;
 870                         }
 871                         if (!strcmp(arg, "--default")) {
 872                                 if (++i >= argc)
 873                                         die("bad --default argument");
 874                                 def = argv[i];
 875                                 continue;
 876                         }
 877                         if (!strcmp(arg, "--merge")) {
 878                                 show_merge = 1;
 879                                 continue;
 880                         }
 881                         if (!strcmp(arg, "--topo-order")) {
 882                                 revs->topo_order = 1;
 883                                 continue;
 884                         }
 885                         if (!strcmp(arg, "--date-order")) {
 886                                 revs->lifo = 0;
 887                                 revs->topo_order = 1;
 888                                 continue;
 889                         }
 890                         if (!strcmp(arg, "--parents")) {
 891                                 revs->parents = 1;
 892                                 continue;
 893                         }
 894                         if (!strcmp(arg, "--dense")) {
 895                                 revs->dense = 1;
 896                                 continue;
 897                         }
 898                         if (!strcmp(arg, "--sparse")) {
 899                                 revs->dense = 0;
 900                                 continue;
 901                         }
 902                         if (!strcmp(arg, "--remove-empty")) {
 903                                 revs->remove_empty_trees = 1;
 904                                 continue;
 905                         }
 906                         if (!strcmp(arg, "--no-merges")) {
 907                                 revs->no_merges = 1;
 908                                 continue;
 909                         }
 910                         if (!strcmp(arg, "--boundary")) {
 911                                 revs->boundary = 1;
 912                                 continue;
 913                         }
 914                         if (!strcmp(arg, "--left-right")) {
 915                                 revs->left_right = 1;
 916                                 continue;
 917                         }
 918                         if (!strcmp(arg, "--objects")) {
 919                                 revs->tag_objects = 1;
 920                                 revs->tree_objects = 1;
 921                                 revs->blob_objects = 1;
 922                                 continue;
 923                         }
 924                         if (!strcmp(arg, "--objects-edge")) {
 925                                 revs->tag_objects = 1;
 926                                 revs->tree_objects = 1;
 927                                 revs->blob_objects = 1;
 928                                 revs->edge_hint = 1;
 929                                 continue;
 930                         }
 931                         if (!strcmp(arg, "--unpacked")) {
 932                                 revs->unpacked = 1;
 933                                 free(revs->ignore_packed);
 934                                 revs->ignore_packed = NULL;
 935                                 revs->num_ignore_packed = 0;
 936                                 continue;
 937                         }
 938                         if (!strncmp(arg, "--unpacked=", 11)) {
 939                                 revs->unpacked = 1;
 940                                 add_ignore_packed(revs, arg+11);
 941                                 continue;
 942                         }
 943                         if (!strcmp(arg, "-r")) {
 944                                 revs->diff = 1;
 945                                 revs->diffopt.recursive = 1;
 946                                 continue;
 947                         }
 948                         if (!strcmp(arg, "-t")) {
 949                                 revs->diff = 1;
 950                                 revs->diffopt.recursive = 1;
 951                                 revs->diffopt.tree_in_recursive = 1;
 952                                 continue;
 953                         }
 954                         if (!strcmp(arg, "-m")) {
 955                                 revs->ignore_merges = 0;
 956                                 continue;
 957                         }
 958                         if (!strcmp(arg, "-c")) {
 959                                 revs->diff = 1;
 960                                 revs->dense_combined_merges = 0;
 961                                 revs->combine_merges = 1;
 962                                 continue;
 963                         }
 964                         if (!strcmp(arg, "--cc")) {
 965                                 revs->diff = 1;
 966                                 revs->dense_combined_merges = 1;
 967                                 revs->combine_merges = 1;
 968                                 continue;
 969                         }
 970                         if (!strcmp(arg, "-v")) {
 971                                 revs->verbose_header = 1;
 972                                 continue;
 973                         }
 974                         if (!strncmp(arg, "--pretty", 8)) {
 975                                 revs->verbose_header = 1;
 976                                 revs->commit_format = get_commit_format(arg+8);
 977                                 continue;
 978                         }
 979                         if (!strcmp(arg, "--root")) {
 980                                 revs->show_root_diff = 1;
 981                                 continue;
 982                         }
 983                         if (!strcmp(arg, "--no-commit-id")) {
 984                                 revs->no_commit_id = 1;
 985                                 continue;
 986                         }
 987                         if (!strcmp(arg, "--always")) {
 988                                 revs->always_show_header = 1;
 989                                 continue;
 990                         }
 991                         if (!strcmp(arg, "--no-abbrev")) {
 992                                 revs->abbrev = 0;
 993                                 continue;
 994                         }
 995                         if (!strcmp(arg, "--abbrev")) {
 996                                 revs->abbrev = DEFAULT_ABBREV;
 997                                 continue;
 998                         }
 999                         if (!strncmp(arg, "--abbrev=", 9)) {
1000                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1001                                 if (revs->abbrev < MINIMUM_ABBREV)
1002                                         revs->abbrev = MINIMUM_ABBREV;
1003                                 else if (revs->abbrev > 40)
1004                                         revs->abbrev = 40;
1005                                 continue;
1006                         }
1007                         if (!strcmp(arg, "--abbrev-commit")) {
1008                                 revs->abbrev_commit = 1;
1009                                 continue;
1010                         }
1011                         if (!strcmp(arg, "--full-diff")) {
1012                                 revs->diff = 1;
1013                                 revs->full_diff = 1;
1014                                 continue;
1015                         }
1016                         if (!strcmp(arg, "--full-history")) {
1017                                 revs->simplify_history = 0;
1018                                 continue;
1019                         }
1020                         if (!strcmp(arg, "--relative-date")) {
1021                                 revs->relative_date = 1;
1022                                 continue;
1023                         }
1024
1025                         /*
1026                          * Grepping the commit log
1027                          */
1028                         if (!strncmp(arg, "--author=", 9)) {
1029                                 add_header_grep(revs, "author", arg+9);
1030                                 continue;
1031                         }
1032                         if (!strncmp(arg, "--committer=", 12)) {
1033                                 add_header_grep(revs, "committer", arg+12);
1034                                 continue;
1035                         }
1036                         if (!strncmp(arg, "--grep=", 7)) {
1037                                 add_message_grep(revs, arg+7);
1038                                 continue;
1039                         }
1040                         if (!strcmp(arg, "--all-match")) {
1041                                 all_match = 1;
1042                                 continue;
1043                         }
1044                         if (!strncmp(arg, "--encoding=", 11)) {
1045                                 arg += 11;
1046                                 if (strcmp(arg, "none"))
1047                                         git_log_output_encoding = strdup(arg);
1048                                 else
1049                                         git_log_output_encoding = "";
1050                                 continue;
1051                         }
1052
1053                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1054                         if (opts > 0) {
1055                                 revs->diff = 1;
1056                                 i += opts - 1;
1057                                 continue;
1058                         }
1059                         *unrecognized++ = arg;
1060                         left++;
1061                         continue;
1062                 }
1063
1064                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1065                         int j;
1066                         if (seen_dashdash || *arg == '^')
1067                                 die("bad revision '%s'", arg);
1068
1069                         /* If we didn't have a "--":
1070                          * (1) all filenames must exist;
1071                          * (2) all rev-args must not be interpretable
1072                          *     as a valid filename.
1073                          * but the latter we have checked in the main loop.
1074                          */
1075                         for (j = i; j < argc; j++)
1076                                 verify_filename(revs->prefix, argv[j]);
1077
1078                         revs->prune_data = get_pathspec(revs->prefix,
1079                                                         argv + i);
1080                         break;
1081                 }
1082         }
1083
1084         if (show_merge)
1085                 prepare_show_merge(revs);
1086         if (def && !revs->pending.nr) {
1087                 unsigned char sha1[20];
1088                 struct object *object;
1089                 if (get_sha1(def, sha1))
1090                         die("bad default revision '%s'", def);
1091                 object = get_reference(revs, def, sha1, 0);
1092                 add_pending_object(revs, object, def);
1093         }
1094
1095         if (revs->topo_order)
1096                 revs->limited = 1;
1097
1098         if (revs->prune_data) {
1099                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1100                 revs->prune_fn = try_to_simplify_commit;
1101                 if (!revs->full_diff)
1102                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1103         }
1104         if (revs->combine_merges) {
1105                 revs->ignore_merges = 0;
1106                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1107                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1108         }
1109         revs->diffopt.abbrev = revs->abbrev;
1110         if (diff_setup_done(&revs->diffopt) < 0)
1111                 die("diff_setup_done failed");
1112
1113         if (revs->grep_filter) {
1114                 revs->grep_filter->all_match = all_match;
1115                 compile_grep_patterns(revs->grep_filter);
1116         }
1117
1118         return left;
1119 }
1120
1121 void prepare_revision_walk(struct rev_info *revs)
1122 {
1123         int nr = revs->pending.nr;
1124         struct object_array_entry *list = revs->pending.objects;
1125
1126         revs->pending.nr = 0;
1127         revs->pending.alloc = 0;
1128         revs->pending.objects = NULL;
1129         while (--nr >= 0) {
1130                 struct commit *commit = handle_commit(revs, list->item, list->name);
1131                 if (commit) {
1132                         if (!(commit->object.flags & SEEN)) {
1133                                 commit->object.flags |= SEEN;
1134                                 insert_by_date(commit, &revs->commits);
1135                         }
1136                 }
1137                 list++;
1138         }
1139
1140         if (revs->no_walk)
1141                 return;
1142         if (revs->limited)
1143                 limit_list(revs);
1144         if (revs->topo_order)
1145                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1146                                              revs->topo_setter,
1147                                              revs->topo_getter);
1148 }
1149
1150 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1151 {
1152         for (;;) {
1153                 struct commit *p = *pp;
1154                 if (!revs->limited)
1155                         add_parents_to_list(revs, p, &revs->commits);
1156                 if (p->parents && p->parents->next)
1157                         return 0;
1158                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1159                         return 0;
1160                 if (!p->parents)
1161                         return -1;
1162                 *pp = p->parents->item;
1163         }
1164 }
1165
1166 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1167 {
1168         struct commit_list **pp = &commit->parents;
1169         while (*pp) {
1170                 struct commit_list *parent = *pp;
1171                 if (rewrite_one(revs, &parent->item) < 0) {
1172                         *pp = parent->next;
1173                         continue;
1174                 }
1175                 pp = &parent->next;
1176         }
1177 }
1178
1179 static void mark_boundary_to_show(struct commit *commit)
1180 {
1181         struct commit_list *p = commit->parents;
1182         while (p) {
1183                 commit = p->item;
1184                 p = p->next;
1185                 if (commit->object.flags & BOUNDARY)
1186                         commit->object.flags |= BOUNDARY_SHOW;
1187         }
1188 }
1189
1190 static int commit_match(struct commit *commit, struct rev_info *opt)
1191 {
1192         if (!opt->grep_filter)
1193                 return 1;
1194         return grep_buffer(opt->grep_filter,
1195                            NULL, /* we say nothing, not even filename */
1196                            commit->buffer, strlen(commit->buffer));
1197 }
1198
1199 static struct commit *get_revision_1(struct rev_info *revs)
1200 {
1201         if (!revs->commits)
1202                 return NULL;
1203
1204         do {
1205                 struct commit_list *entry = revs->commits;
1206                 struct commit *commit = entry->item;
1207
1208                 revs->commits = entry->next;
1209                 free(entry);
1210
1211                 /*
1212                  * If we haven't done the list limiting, we need to look at
1213                  * the parents here. We also need to do the date-based limiting
1214                  * that we'd otherwise have done in limit_list().
1215                  */
1216                 if (!revs->limited) {
1217                         if (revs->max_age != -1 &&
1218                             (commit->date < revs->max_age))
1219                                 continue;
1220                         add_parents_to_list(revs, commit, &revs->commits);
1221                 }
1222                 if (commit->object.flags & SHOWN)
1223                         continue;
1224
1225                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1226                                                     revs->ignore_packed))
1227                     continue;
1228
1229                 /* We want to show boundary commits only when their
1230                  * children are shown.  When path-limiter is in effect,
1231                  * rewrite_parents() drops some commits from getting shown,
1232                  * and there is no point showing boundary parents that
1233                  * are not shown.  After rewrite_parents() rewrites the
1234                  * parents of a commit that is shown, we mark the boundary
1235                  * parents with BOUNDARY_SHOW.
1236                  */
1237                 if (commit->object.flags & BOUNDARY_SHOW) {
1238                         commit->object.flags |= SHOWN;
1239                         return commit;
1240                 }
1241                 if (commit->object.flags & UNINTERESTING)
1242                         continue;
1243                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1244                         continue;
1245                 if (revs->no_merges &&
1246                     commit->parents && commit->parents->next)
1247                         continue;
1248                 if (!commit_match(commit, revs))
1249                         continue;
1250                 if (revs->prune_fn && revs->dense) {
1251                         /* Commit without changes? */
1252                         if (!(commit->object.flags & TREECHANGE)) {
1253                                 /* drop merges unless we want parenthood */
1254                                 if (!revs->parents)
1255                                         continue;
1256                                 /* non-merge - always ignore it */
1257                                 if (!commit->parents || !commit->parents->next)
1258                                         continue;
1259                         }
1260                         if (revs->parents)
1261                                 rewrite_parents(revs, commit);
1262                 }
1263                 if (revs->boundary)
1264                         mark_boundary_to_show(commit);
1265                 commit->object.flags |= SHOWN;
1266                 return commit;
1267         } while (revs->commits);
1268         return NULL;
1269 }
1270
1271 struct commit *get_revision(struct rev_info *revs)
1272 {
1273         struct commit *c = NULL;
1274
1275         if (0 < revs->skip_count) {
1276                 while ((c = get_revision_1(revs)) != NULL) {
1277                         if (revs->skip_count-- <= 0)
1278                                 break;
1279                 }
1280         }
1281
1282         /* Check the max_count ... */
1283         switch (revs->max_count) {
1284         case -1:
1285                 break;
1286         case 0:
1287                 return NULL;
1288         default:
1289                 revs->max_count--;
1290         }
1291         if (c)
1292                 return c;
1293         return get_revision_1(revs);
1294 }